[error] add 'ot::Error' and 'kError{Name}' for use by core modules (#6237)

This commit adds a new core header files `common/error.hpp` which
defines `ot::Error` (mirroring `otError`) and `kError{Name}` constants
(mirroring the public `OT_ERROR_{NAME}` definitions). The new (C++
style) definitions are used by core modules. This commit also moves
`otThreadErrorToString()` (from `logging.hpp` to `error.hpp`) and
renames it to `ErrorToString()` which is used as the internal (to
core) function to covert an `Error` to a string.

Android.mk

@@ -172,6 +172,7 @@ LOCAL_SRC_FILES                                          := \
     src/core/api/diags_api.cpp                              \
     src/core/api/dns_api.cpp                                \
     src/core/api/entropy_api.cpp                            \
+    src/core/api/error_api.cpp                              \
     src/core/api/heap_api.cpp                               \
     src/core/api/icmp6_api.cpp                              \
     src/core/api/instance_api.cpp                           \
@@ -210,6 +211,7 @@ LOCAL_SRC_FILES                                          := \
     src/core/coap/coap_message.cpp                          \
     src/core/coap/coap_secure.cpp                           \
     src/core/common/crc16.cpp                               \
+    src/core/common/error.cpp                               \
     src/core/common/instance.cpp                            \
     src/core/common/logging.cpp                             \
     src/core/common/message.cpp                             \

src/core/BUILD.gn

@@ -300,6 +300,7 @@ openthread_core_files = [
   "api/diags_api.cpp",
   "api/dns_api.cpp",
   "api/entropy_api.cpp",
+  "api/error_api.cpp",
   "api/heap_api.cpp",
   "api/icmp6_api.cpp",
   "api/instance_api.cpp",
@@ -357,6 +358,8 @@ openthread_core_files = [
   "common/debug.hpp",
   "common/encoding.hpp",
   "common/equatable.hpp",
+  "common/error.cpp",
+  "common/error.hpp",
   "common/extension.hpp",
   "common/instance.cpp",
   "common/instance.hpp",
@@ -618,11 +621,13 @@ openthread_core_files = [
 
 openthread_radio_sources = [
   "api/diags_api.cpp",
+  "api/error_api.cpp",
   "api/instance_api.cpp",
   "api/link_raw_api.cpp",
   "api/logging_api.cpp",
   "api/random_noncrypto_api.cpp",
   "api/tasklet_api.cpp",
+  "common/error.hpp",
   "common/instance.cpp",
   "common/logging.cpp",
   "common/random_manager.cpp",

src/core/CMakeLists.txt

@@ -48,6 +48,7 @@ set(COMMON_SOURCES
     api/diags_api.cpp
     api/dns_api.cpp
     api/entropy_api.cpp
+    api/error_api.cpp
     api/heap_api.cpp
     api/icmp6_api.cpp
     api/instance_api.cpp
@@ -86,6 +87,7 @@ set(COMMON_SOURCES
     coap/coap_message.cpp
     coap/coap_secure.cpp
     common/crc16.cpp
+    common/error.cpp
     common/instance.cpp
     common/logging.cpp
     common/message.cpp

src/core/Makefile.am

@@ -125,6 +125,7 @@ SOURCES_COMMON                                  = \
     api/diags_api.cpp                             \
     api/dns_api.cpp                               \
     api/entropy_api.cpp                           \
+    api/error_api.cpp                             \
     api/heap_api.cpp                              \
     api/icmp6_api.cpp                             \
     api/instance_api.cpp                          \
@@ -163,6 +164,7 @@ SOURCES_COMMON                                  = \
     coap/coap_message.cpp                         \
     coap/coap_secure.cpp                          \
     common/crc16.cpp                              \
+    common/error.cpp                              \
     common/instance.cpp                           \
     common/logging.cpp                            \
     common/message.cpp                            \
@@ -291,12 +293,14 @@ EXTRA_DIST                                 = \
 
 libopenthread_radio_a_SOURCES              = \
     api/diags_api.cpp                        \
+    api/error_api.cpp                        \
     api/heap_api.cpp                         \
     api/instance_api.cpp                     \
     api/link_raw_api.cpp                     \
     api/logging_api.cpp                      \
     api/random_noncrypto_api.cpp             \
     api/tasklet_api.cpp                      \
+    common/error.cpp                         \
     common/instance.cpp                      \
     common/logging.cpp                       \
     common/random_manager.cpp                \
@@ -369,6 +373,7 @@ HEADERS_COMMON                                  = \
     common/debug.hpp                              \
     common/encoding.hpp                           \
     common/equatable.hpp                          \
+    common/error.hpp                              \
     common/extension.hpp                          \
     common/instance.hpp                           \
     common/iterator_utils.hpp                     \

src/core/api/border_router_api.cpp

@@ -74,7 +74,7 @@ otError otBorderRouterGetNetData(otInstance *aInstance, bool aStable, uint8_t *a
 
 otError otBorderRouterAddOnMeshPrefix(otInstance *aInstance, const otBorderRouterConfig *aConfig)
 {
-    otError                                error;
+    Error                                  error;
     Instance &                             instance = *static_cast<Instance *>(aInstance);
     const NetworkData::OnMeshPrefixConfig *config   = static_cast<const NetworkData::OnMeshPrefixConfig *>(aConfig);
 
@@ -99,7 +99,7 @@ exit:
 
 otError otBorderRouterRemoveOnMeshPrefix(otInstance *aInstance, const otIp6Prefix *aPrefix)
 {
-    otError            error    = OT_ERROR_NONE;
+    Error              error    = kErrorNone;
     Instance &         instance = *static_cast<Instance *>(aInstance);
     const Ip6::Prefix *prefix   = static_cast<const Ip6::Prefix *>(aPrefix);
 
@@ -108,7 +108,7 @@ otError otBorderRouterRemoveOnMeshPrefix(otInstance *aInstance, const otIp6Prefi
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
     error = instance.Get<BackboneRouter::Local>().RemoveDomainPrefix(*prefix);
 
-    if (error == OT_ERROR_NOT_FOUND)
+    if (error == kErrorNotFound)
 #endif
     {
         error = instance.Get<NetworkData::Local>().RemoveOnMeshPrefix(*prefix);
@@ -166,7 +166,7 @@ otError otBorderRouterRegister(otInstance *aInstance)
 
     instance.Get<NetworkData::Notifier>().HandleServerDataUpdated();
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 #endif // OPENTHREAD_CONFIG_BORDER_ROUTER_ENABLE

src/core/api/coap_api.cpp

@@ -224,13 +224,13 @@ otError otCoapSendRequestBlockWiseWithParameters(otInstance *                aIn
                                                  otCoapBlockwiseTransmitHook aTransmitHook,
                                                  otCoapBlockwiseReceiveHook  aReceiveHook)
 {
-    otError                   error;
+    Error                     error;
     Instance &                instance     = *static_cast<Instance *>(aInstance);
     const Coap::TxParameters &txParameters = Coap::TxParameters::From(aTxParameters);
 
     if (aTxParameters != nullptr)
     {
-        VerifyOrExit(txParameters.IsValid(), error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(txParameters.IsValid(), error = kErrorInvalidArgs);
     }
 
     error = instance.GetApplicationCoap().SendMessage(*static_cast<Coap::Message *>(aMessage),
@@ -249,13 +249,13 @@ otError otCoapSendRequestWithParameters(otInstance *              aInstance,
                                         void *                    aContext,
                                         const otCoapTxParameters *aTxParameters)
 {
-    otError                   error;
+    Error                     error;
     Instance &                instance     = *static_cast<Instance *>(aInstance);
     const Coap::TxParameters &txParameters = Coap::TxParameters::From(aTxParameters);
 
     if (aTxParameters != nullptr)
     {
-        VerifyOrExit(txParameters.IsValid(), error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(txParameters.IsValid(), error = kErrorInvalidArgs);
     }
 
     error = instance.GetApplicationCoap().SendMessage(*static_cast<Coap::Message *>(aMessage),

src/core/api/commissioner_api.cpp

@@ -60,7 +60,7 @@ otError otCommissionerStop(otInstance *aInstance)
 
 otError otCommissionerAddJoiner(otInstance *aInstance, const otExtAddress *aEui64, const char *aPskd, uint32_t aTimeout)
 {
-    otError                error;
+    Error                  error;
     MeshCoP::Commissioner &commissioner = static_cast<Instance *>(aInstance)->Get<MeshCoP::Commissioner>();
 
     if (aEui64 == nullptr)
@@ -95,7 +95,7 @@ otError otCommissionerGetNextJoinerInfo(otInstance *aInstance, uint16_t *aIterat
 
 otError otCommissionerRemoveJoiner(otInstance *aInstance, const otExtAddress *aEui64)
 {
-    otError                error;
+    Error                  error;
     MeshCoP::Commissioner &commissioner = static_cast<Instance *>(aInstance)->Get<MeshCoP::Commissioner>();
 
     if (aEui64 == nullptr)

src/core/api/error_api.cpp

@@ -0,0 +1,43 @@
+/*
+ *  Copyright (c) 2017-2021, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file implements the OpenThread error code functions.
+ */
+
+#include "openthread-core-config.h"
+
+#include "common/error.hpp"
+
+using namespace ot;
+
+const char *otThreadErrorToString(otError aError)
+{
+    return ErrorToString(aError);
+}

src/core/api/ip6_api.cpp

@@ -46,11 +46,11 @@ using namespace ot;
 
 otError otIp6SetEnabled(otInstance *aInstance, bool aEnabled)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
 #if OPENTHREAD_CONFIG_LINK_RAW_ENABLE
-    VerifyOrExit(!instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 #endif
 
     if (aEnabled)
@@ -246,12 +246,12 @@ bool otIp6IsAddressUnspecified(const otIp6Address *aAddress)
 
 otError otIp6SelectSourceAddress(otInstance *aInstance, otMessageInfo *aMessageInfo)
 {
-    otError                         error    = OT_ERROR_NONE;
+    Error                           error    = kErrorNone;
     Instance &                      instance = *static_cast<Instance *>(aInstance);
     const Ip6::NetifUnicastAddress *netifAddr;
 
     netifAddr = instance.Get<Ip6::Ip6>().SelectSourceAddress(*static_cast<Ip6::MessageInfo *>(aMessageInfo));
-    VerifyOrExit(netifAddr != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(netifAddr != nullptr, error = kErrorNotFound);
     aMessageInfo->mSockAddr = netifAddr->GetAddress();
 
 exit:

src/core/api/jam_detection_api.cpp

@@ -48,7 +48,7 @@ otError otJamDetectionSetRssiThreshold(otInstance *aInstance, int8_t aRssiThresh
 
     instance.Get<Utils::JamDetector>().SetRssiThreshold(aRssiThreshold);
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 int8_t otJamDetectionGetRssiThreshold(otInstance *aInstance)

src/core/api/joiner_api.cpp

@@ -80,7 +80,7 @@ const otExtAddress *otJoinerGetId(otInstance *aInstance)
 
 otError otJoinerSetDiscerner(otInstance *aInstance, otJoinerDiscerner *aDiscerner)
 {
-    otError          error  = OT_ERROR_NONE;
+    Error            error  = kErrorNone;
     MeshCoP::Joiner &joiner = static_cast<Instance *>(aInstance)->Get<MeshCoP::Joiner>();
 
     if (aDiscerner != nullptr)

src/core/api/link_api.cpp

@@ -63,7 +63,7 @@ uint8_t otLinkGetChannel(otInstance *aInstance)
 
 otError otLinkSetChannel(otInstance *aInstance, uint8_t aChannel)
 {
-    otError   error;
+    Error     error;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
 #if OPENTHREAD_CONFIG_LINK_RAW_ENABLE
@@ -74,7 +74,7 @@ otError otLinkSetChannel(otInstance *aInstance, uint8_t aChannel)
     }
 #endif
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     SuccessOrExit(error = instance.Get<Mac::Mac>().SetPanChannel(aChannel));
     instance.Get<MeshCoP::ActiveDataset>().Clear();
@@ -93,10 +93,10 @@ uint32_t otLinkGetSupportedChannelMask(otInstance *aInstance)
 
 otError otLinkSetSupportedChannelMask(otInstance *aInstance, uint32_t aChannelMask)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetSupportedChannelMask(static_cast<Mac::ChannelMask>(aChannelMask));
 
@@ -113,11 +113,11 @@ const otExtAddress *otLinkGetExtendedAddress(otInstance *aInstance)
 
 otError otLinkSetExtendedAddress(otInstance *aInstance, const otExtAddress *aExtAddress)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     OT_ASSERT(aExtAddress != nullptr);
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetExtAddress(*static_cast<const Mac::ExtAddress *>(aExtAddress));
 
@@ -143,10 +143,10 @@ otPanId otLinkGetPanId(otInstance *aInstance)
 
 otError otLinkSetPanId(otInstance *aInstance, otPanId aPanId)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetPanId(aPanId);
     instance.Get<MeshCoP::ActiveDataset>().Clear();
@@ -378,11 +378,11 @@ bool otLinkIsPromiscuous(otInstance *aInstance)
 
 otError otLinkSetPromiscuous(otInstance *aInstance, bool aPromiscuous)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     // cannot enable IEEE 802.15.4 promiscuous mode if the Thread interface is enabled
-    VerifyOrExit(!instance.Get<ThreadNetif>().IsUp(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!instance.Get<ThreadNetif>().IsUp(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetPromiscuous(aPromiscuous);
 
@@ -392,11 +392,11 @@ exit:
 
 otError otLinkSetEnabled(otInstance *aInstance, bool aEnable)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     // cannot disable the link layer if the Thread interface is enabled
-    VerifyOrExit(!instance.Get<ThreadNetif>().IsUp(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!instance.Get<ThreadNetif>().IsUp(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetEnabled(aEnable);
 
@@ -490,10 +490,10 @@ uint8_t otLinkCslGetChannel(otInstance *aInstance)
 
 otError otLinkCslSetChannel(otInstance *aInstance, uint8_t aChannel)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(Radio::IsCslChannelValid(aChannel), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(Radio::IsCslChannelValid(aChannel), error = kErrorInvalidArgs);
 
     instance.Get<Mac::Mac>().SetCslChannel(aChannel);
 
@@ -508,10 +508,10 @@ uint16_t otLinkCslGetPeriod(otInstance *aInstance)
 
 otError otLinkCslSetPeriod(otInstance *aInstance, uint16_t aPeriod)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit((aPeriod == 0 || kMinCslPeriod <= aPeriod), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit((aPeriod == 0 || kMinCslPeriod <= aPeriod), error = kErrorInvalidArgs);
     instance.Get<Mac::Mac>().SetCslPeriod(aPeriod);
 
 exit:
@@ -525,10 +525,10 @@ uint32_t otLinkCslGetTimeout(otInstance *aInstance)
 
 otError otLinkCslSetTimeout(otInstance *aInstance, uint32_t aTimeout)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(kMaxCslTimeout >= aTimeout, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(kMaxCslTimeout >= aTimeout, error = kErrorInvalidArgs);
     instance.Get<Mac::Mac>().SetCslTimeout(aTimeout);
 
 exit:

src/core/api/link_raw_api.cpp

@@ -71,10 +71,10 @@ bool otLinkRawGetPromiscuous(otInstance *aInstance)
 
 otError otLinkRawSetPromiscuous(otInstance *aInstance, bool aEnable)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
     instance.Get<Radio>().SetPromiscuous(aEnable);
 
 exit:
@@ -83,10 +83,10 @@ exit:
 
 otError otLinkRawSleep(otInstance *aInstance)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     error = instance.Get<Radio>().Sleep();
 
@@ -129,10 +129,10 @@ otError otLinkRawEnergyScan(otInstance *            aInstance,
 
 otError otLinkRawSrcMatchEnable(otInstance *aInstance, bool aEnable)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     instance.Get<Radio>().EnableSrcMatch(aEnable);
 
@@ -142,10 +142,10 @@ exit:
 
 otError otLinkRawSrcMatchAddShortEntry(otInstance *aInstance, uint16_t aShortAddress)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     error = instance.Get<Radio>().AddSrcMatchShortEntry(aShortAddress);
 
@@ -156,10 +156,10 @@ exit:
 otError otLinkRawSrcMatchAddExtEntry(otInstance *aInstance, const otExtAddress *aExtAddress)
 {
     Mac::ExtAddress address;
-    otError         error    = OT_ERROR_NONE;
+    Error           error    = kErrorNone;
     Instance &      instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     address.Set(aExtAddress->m8, Mac::ExtAddress::kReverseByteOrder);
     error = instance.Get<Radio>().AddSrcMatchExtEntry(address);
@@ -170,10 +170,10 @@ exit:
 
 otError otLinkRawSrcMatchClearShortEntry(otInstance *aInstance, uint16_t aShortAddress)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
     error = instance.Get<Radio>().ClearSrcMatchShortEntry(aShortAddress);
 
 exit:
@@ -183,10 +183,10 @@ exit:
 otError otLinkRawSrcMatchClearExtEntry(otInstance *aInstance, const otExtAddress *aExtAddress)
 {
     Mac::ExtAddress address;
-    otError         error    = OT_ERROR_NONE;
+    Error           error    = kErrorNone;
     Instance &      instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     address.Set(aExtAddress->m8, Mac::ExtAddress::kReverseByteOrder);
     error = instance.Get<Radio>().ClearSrcMatchExtEntry(address);
@@ -197,10 +197,10 @@ exit:
 
 otError otLinkRawSrcMatchClearShortEntries(otInstance *aInstance)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     instance.Get<Radio>().ClearSrcMatchShortEntries();
 
@@ -210,10 +210,10 @@ exit:
 
 otError otLinkRawSrcMatchClearExtEntries(otInstance *aInstance)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mac::LinkRaw>().IsEnabled(), error = kErrorInvalidState);
 
     instance.Get<Radio>().ClearSrcMatchExtEntries();
 

src/core/api/logging_api.cpp

@@ -51,7 +51,7 @@ otLogLevel otLoggingGetLevel(void)
 #if OPENTHREAD_CONFIG_LOG_LEVEL_DYNAMIC_ENABLE
 otError otLoggingSetLevel(otLogLevel aLogLevel)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     if (aLogLevel <= OT_LOG_LEVEL_DEBG && aLogLevel >= OT_LOG_LEVEL_NONE)
     {
@@ -59,7 +59,7 @@ otError otLoggingSetLevel(otLogLevel aLogLevel)
     }
     else
     {
-        error = OT_ERROR_INVALID_ARGS;
+        error = kErrorInvalidArgs;
     }
 
     return error;

src/core/api/multi_radio_api.cpp

@@ -49,13 +49,13 @@ otError otMultiRadioGetNeighborInfo(otInstance *              aInstance,
                                     const otExtAddress *      aExtAddress,
                                     otMultiRadioNeighborInfo *aInfo)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
     Neighbor *neighbor;
 
     neighbor = instance.Get<NeighborTable>().FindNeighbor(*static_cast<const Mac::ExtAddress *>(aExtAddress),
                                                           Neighbor::kInStateAnyExceptInvalid);
-    VerifyOrExit(neighbor != NULL, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(neighbor != NULL, error = kErrorNotFound);
 
     neighbor->PopulateMultiRadioInfo(*aInfo);
 

src/core/api/netdata_api.cpp

@@ -53,11 +53,11 @@ otError otNetDataGetNextOnMeshPrefix(otInstance *           aInstance,
                                      otNetworkDataIterator *aIterator,
                                      otBorderRouterConfig * aConfig)
 {
-    otError                          error    = OT_ERROR_NONE;
+    Error                            error    = kErrorNone;
     Instance &                       instance = *static_cast<Instance *>(aInstance);
     NetworkData::OnMeshPrefixConfig *config   = static_cast<NetworkData::OnMeshPrefixConfig *>(aConfig);
 
-    VerifyOrExit(aIterator && aConfig, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aIterator && aConfig, error = kErrorInvalidArgs);
 
     error = instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(*aIterator, *config);
 
@@ -67,10 +67,10 @@ exit:
 
 otError otNetDataGetNextRoute(otInstance *aInstance, otNetworkDataIterator *aIterator, otExternalRouteConfig *aConfig)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(aIterator && aConfig, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aIterator && aConfig, error = kErrorInvalidArgs);
 
     error = instance.Get<NetworkData::Leader>().GetNextExternalRoute(
         *aIterator, *static_cast<NetworkData::ExternalRouteConfig *>(aConfig));
@@ -81,10 +81,10 @@ exit:
 
 otError otNetDataGetNextService(otInstance *aInstance, otNetworkDataIterator *aIterator, otServiceConfig *aConfig)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(aIterator && aConfig, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aIterator && aConfig, error = kErrorInvalidArgs);
 
     error = instance.Get<NetworkData::Leader>().GetNextService(*aIterator,
                                                                *static_cast<NetworkData::ServiceConfig *>(aConfig));

src/core/api/network_time_api.cpp

@@ -51,10 +51,10 @@ otNetworkTimeStatus otNetworkTimeGet(otInstance *aInstance, uint64_t *aNetworkTi
 
 otError otNetworkTimeSetSyncPeriod(otInstance *aInstance, uint16_t aTimeSyncPeriod)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<TimeSync>().SetTimeSyncPeriod(aTimeSyncPeriod);
 
@@ -71,10 +71,10 @@ uint16_t otNetworkTimeGetSyncPeriod(otInstance *aInstance)
 
 otError otNetworkTimeSetXtalThreshold(otInstance *aInstance, uint16_t aXtalThreshold)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<TimeSync>().SetXtalThreshold(aXtalThreshold);
 

src/core/api/server_api.cpp

@@ -73,10 +73,10 @@ otError otServerRemoveService(otInstance *   aInstance,
 
 otError otServerGetNextService(otInstance *aInstance, otNetworkDataIterator *aIterator, otServiceConfig *aConfig)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(aIterator && aConfig, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aIterator && aConfig, error = kErrorInvalidArgs);
 
     error = instance.Get<NetworkData::Local>().GetNextService(*aIterator,
                                                               *static_cast<NetworkData::ServiceConfig *>(aConfig));
@@ -91,7 +91,7 @@ otError otServerRegister(otInstance *aInstance)
 
     instance.Get<NetworkData::Notifier>().HandleServerDataUpdated();
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 #endif // OPENTHREAD_CONFIG_TMF_NETDATA_SERVICE_ENABLE

src/core/api/thread_api.cpp

@@ -66,12 +66,12 @@ const otExtendedPanId *otThreadGetExtendedPanId(otInstance *aInstance)
 
 otError otThreadSetExtendedPanId(otInstance *aInstance, const otExtendedPanId *aExtendedPanId)
 {
-    otError                   error    = OT_ERROR_NONE;
+    Error                     error    = kErrorNone;
     Instance &                instance = *static_cast<Instance *>(aInstance);
     const Mac::ExtendedPanId &extPanId = *static_cast<const Mac::ExtendedPanId *>(aExtendedPanId);
     Mle::MeshLocalPrefix      prefix;
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<Mac::Mac>().SetExtendedPanId(extPanId);
 
@@ -120,12 +120,12 @@ const otMasterKey *otThreadGetMasterKey(otInstance *aInstance)
 
 otError otThreadSetMasterKey(otInstance *aInstance, const otMasterKey *aKey)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     OT_ASSERT(aKey != nullptr);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     error = instance.Get<KeyManager>().SetMasterKey(*static_cast<const MasterKey *>(aKey));
     instance.Get<MeshCoP::ActiveDataset>().Clear();
@@ -158,10 +158,10 @@ const otMeshLocalPrefix *otThreadGetMeshLocalPrefix(otInstance *aInstance)
 
 otError otThreadSetMeshLocalPrefix(otInstance *aInstance, const otMeshLocalPrefix *aMeshLocalPrefix)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<Mle::MleRouter>().SetMeshLocalPrefix(*static_cast<const Mle::MeshLocalPrefix *>(aMeshLocalPrefix));
     instance.Get<MeshCoP::ActiveDataset>().Clear();
@@ -187,10 +187,10 @@ const char *otThreadGetNetworkName(otInstance *aInstance)
 
 otError otThreadSetNetworkName(otInstance *aInstance, const char *aNetworkName)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     error = instance.Get<Mac::Mac>().SetNetworkName(aNetworkName);
     instance.Get<MeshCoP::ActiveDataset>().Clear();
@@ -210,10 +210,10 @@ const char *otThreadGetDomainName(otInstance *aInstance)
 
 otError otThreadSetDomainName(otInstance *aInstance, const char *aDomainName)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     error = instance.Get<Mac::Mac>().SetDomainName(aDomainName);
 
@@ -225,7 +225,7 @@ exit:
 otError otThreadSetFixedDuaInterfaceIdentifier(otInstance *aInstance, const otIp6InterfaceIdentifier *aIid)
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
 
     if (aIid)
     {
@@ -317,11 +317,11 @@ otDeviceRole otThreadGetDeviceRole(otInstance *aInstance)
 otError otThreadGetLeaderData(otInstance *aInstance, otLeaderData *aLeaderData)
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
 
     OT_ASSERT(aLeaderData != nullptr);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsAttached(), error = OT_ERROR_DETACHED);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsAttached(), error = kErrorDetached);
     *aLeaderData = instance.Get<Mle::MleRouter>().GetLeaderData();
 
 exit:
@@ -359,14 +359,14 @@ uint16_t otThreadGetRloc16(otInstance *aInstance)
 otError otThreadGetParentInfo(otInstance *aInstance, otRouterInfo *aParentInfo)
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Router *  parent;
 
     OT_ASSERT(aParentInfo != nullptr);
 
     // Reference device needs get the original parent's info even after the node state changed.
 #if !OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsChild(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsChild(), error = kErrorInvalidState);
 #endif
 
     parent = &instance.Get<Mle::MleRouter>().GetParent();
@@ -390,14 +390,14 @@ exit:
 
 otError otThreadGetParentAverageRssi(otInstance *aInstance, int8_t *aParentRssi)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     OT_ASSERT(aParentRssi != nullptr);
 
     *aParentRssi = instance.Get<Mle::MleRouter>().GetParent().GetLinkInfo().GetAverageRss();
 
-    VerifyOrExit(*aParentRssi != OT_RADIO_RSSI_INVALID, error = OT_ERROR_FAILED);
+    VerifyOrExit(*aParentRssi != OT_RADIO_RSSI_INVALID, error = kErrorFailed);
 
 exit:
     return error;
@@ -405,14 +405,14 @@ exit:
 
 otError otThreadGetParentLastRssi(otInstance *aInstance, int8_t *aLastRssi)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     OT_ASSERT(aLastRssi != nullptr);
 
     *aLastRssi = instance.Get<Mle::MleRouter>().GetParent().GetLinkInfo().GetLastRss();
 
-    VerifyOrExit(*aLastRssi != OT_RADIO_RSSI_INVALID, error = OT_ERROR_FAILED);
+    VerifyOrExit(*aLastRssi != OT_RADIO_RSSI_INVALID, error = kErrorFailed);
 
 exit:
     return error;
@@ -420,7 +420,7 @@ exit:
 
 otError otThreadSetEnabled(otInstance *aInstance, bool aEnabled)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     if (aEnabled)

src/core/api/thread_ftd_api.cpp

@@ -139,7 +139,7 @@ otError otThreadSetJoinerUdpPort(otInstance *aInstance, uint16_t aJoinerUdpPort)
 
     instance.Get<MeshCoP::JoinerRouter>().SetJoinerUdpPort(aJoinerUdpPort);
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 uint32_t otThreadGetContextIdReuseDelay(otInstance *aInstance)
@@ -186,10 +186,10 @@ void otThreadSetRouterUpgradeThreshold(otInstance *aInstance, uint8_t aThreshold
 
 otError otThreadReleaseRouterId(otInstance *aInstance, uint8_t aRouterId)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(aRouterId <= Mle::kMaxRouterId, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aRouterId <= Mle::kMaxRouterId, error = kErrorInvalidArgs);
 
     error = instance.Get<RouterTable>().Release(aRouterId);
 
@@ -199,7 +199,7 @@ exit:
 
 otError otThreadBecomeRouter(otInstance *aInstance)
 {
-    otError   error    = OT_ERROR_INVALID_STATE;
+    Error     error    = kErrorInvalidState;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
     switch (instance.Get<Mle::MleRouter>().GetRole())
@@ -214,7 +214,7 @@ otError otThreadBecomeRouter(otInstance *aInstance)
 
     case Mle::kRoleRouter:
     case Mle::kRoleLeader:
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
         break;
     }
 
@@ -279,20 +279,20 @@ otError otThreadGetChildNextIp6Address(otInstance *               aInstance,
                                        otChildIp6AddressIterator *aIterator,
                                        otIp6Address *             aAddress)
 {
-    otError      error    = OT_ERROR_NONE;
+    Error        error    = kErrorNone;
     Instance &   instance = *static_cast<Instance *>(aInstance);
     const Child *child;
 
     OT_ASSERT(aIterator != nullptr && aAddress != nullptr);
 
     child = instance.Get<ChildTable>().GetChildAtIndex(aChildIndex);
-    VerifyOrExit(child != nullptr, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(child != nullptr, error = kErrorInvalidArgs);
-    VerifyOrExit(child->IsStateValidOrRestoring(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(child->IsStateValidOrRestoring(), error = kErrorInvalidArgs);
 
     {
         Child::AddressIterator iter(*child, *aIterator);
 
-        VerifyOrExit(!iter.IsDone(), error = OT_ERROR_NOT_FOUND);
+        VerifyOrExit(!iter.IsDone(), error = kErrorNotFound);
         *aAddress = *iter.GetAddress();
 
         iter++;
@@ -352,10 +352,10 @@ const otPskc *otThreadGetPskc(otInstance *aInstance)
 
 otError otThreadSetPskc(otInstance *aInstance, const otPskc *aPskc)
 {
-    otError   error    = OT_ERROR_NONE;
+    Error     error    = kErrorNone;
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(instance.Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
 
     instance.Get<KeyManager>().SetPskc(*static_cast<const Pskc *>(aPskc));
     instance.Get<MeshCoP::ActiveDataset>().Clear();

src/core/backbone_router/backbone_tmf.cpp

@@ -41,9 +41,9 @@
 namespace ot {
 namespace BackboneRouter {
 
-otError BackboneTmfAgent::Start(void)
+Error BackboneTmfAgent::Start(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     SuccessOrExit(error = Coap::Start(kBackboneUdpPort, OT_NETIF_BACKBONE));
     SubscribeMulticast(Get<Local>().GetAllNetworkBackboneRoutersAddress());
@@ -52,14 +52,11 @@ exit:
     return error;
 }
 
-otError BackboneTmfAgent::Filter(const ot::Coap::Message &aMessage,
+Error BackboneTmfAgent::Filter(const ot::Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo, void *aContext)
-                                 const Ip6::MessageInfo & aMessageInfo,
-                                 void *                   aContext)
 {
     OT_UNUSED_VARIABLE(aMessage);
 
-    return static_cast<BackboneTmfAgent *>(aContext)->IsBackboneTmfMessage(aMessageInfo) ? OT_ERROR_NONE
+    return static_cast<BackboneTmfAgent *>(aContext)->IsBackboneTmfMessage(aMessageInfo) ? kErrorNone : kErrorNotTmf;
-                                                                                         : OT_ERROR_NOT_TMF;
 }
 
 bool BackboneTmfAgent::IsBackboneTmfMessage(const Ip6::MessageInfo &aMessageInfo) const
@@ -80,7 +77,7 @@ bool BackboneTmfAgent::IsBackboneTmfMessage(const Ip6::MessageInfo &aMessageInfo
 
 void BackboneTmfAgent::SubscribeMulticast(const Ip6::Address &aAddress)
 {
-    otError error;
+    Error error;
 
     error = mSocket.JoinNetifMulticastGroup(OT_NETIF_BACKBONE, aAddress);
 
@@ -89,7 +86,7 @@ void BackboneTmfAgent::SubscribeMulticast(const Ip6::Address &aAddress)
 
 void BackboneTmfAgent::UnsubscribeMulticast(const Ip6::Address &aAddress)
 {
-    otError error;
+    Error error;
 
     error = mSocket.LeaveNetifMulticastGroup(OT_NETIF_BACKBONE, aAddress);
 

src/core/backbone_router/backbone_tmf.hpp

@@ -66,11 +66,11 @@ public:
     /**
      * This method starts the Backbone TMF agent.
      *
-     * @retval OT_ERROR_NONE    Successfully started the CoAP service.
+     * @retval kErrorNone    Successfully started the CoAP service.
-     * @retval OT_ERROR_FAILED  Failed to start the Backbone TMF agent.
+     * @retval kErrorFailed  Failed to start the Backbone TMF agent.
      *
      */
-    otError Start(void);
+    Error Start(void);
 
     /**
      * This method returns whether @p aMessageInfo meets Backbone Thread Management Framework Addressing Rules.
@@ -98,7 +98,7 @@ public:
     void UnsubscribeMulticast(const Ip6::Address &aAddress);
 
 private:
-    static otError Filter(const ot::Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo, void *aContext);
+    static Error Filter(const ot::Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo, void *aContext);
 };
 
 } // namespace BackboneRouter

src/core/backbone_router/bbr_leader.cpp

@@ -57,11 +57,11 @@ void Leader::Reset(void)
     mDomainPrefix.SetLength(0);
 }
 
-otError Leader::GetConfig(BackboneRouterConfig &aConfig) const
+Error Leader::GetConfig(BackboneRouterConfig &aConfig) const
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(HasPrimary(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(HasPrimary(), error = kErrorNotFound);
 
     aConfig = mConfig;
 
@@ -69,11 +69,11 @@ exit:
     return error;
 }
 
-otError Leader::GetServiceId(uint8_t &aServiceId) const
+Error Leader::GetServiceId(uint8_t &aServiceId) const
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(HasPrimary(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(HasPrimary(), error = kErrorNotFound);
     error = Get<NetworkData::Service::Manager>().GetServiceId<NetworkData::Service::BackboneRouter>(
         /* aServerStable */ true, aServiceId);
 
@@ -256,7 +256,7 @@ void Leader::UpdateDomainPrefixConfig(void)
     DomainPrefixState               state;
     bool                            found = false;
 
-    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == OT_ERROR_NONE)
+    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == kErrorNone)
     {
         if (config.mDp)
         {

src/core/backbone_router/bbr_leader.hpp

@@ -106,22 +106,22 @@ public:
      *
      * @param[out]  aConfig        The Primary Backbone Router information.
      *
-     * @retval OT_ERROR_NONE       Successfully got the Primary Backbone Router information.
+     * @retval kErrorNone          Successfully got the Primary Backbone Router information.
-     * @retval OT_ERROR_NOT_FOUND  No Backbone Router in the Thread Network.
+     * @retval kErrorNotFound      No Backbone Router in the Thread Network.
      *
      */
-    otError GetConfig(BackboneRouterConfig &aConfig) const;
+    Error GetConfig(BackboneRouterConfig &aConfig) const;
 
     /**
      * This method gets the Backbone Router Service ID.
      *
      * @param[out]  aServiceId     The reference whether to put the Backbone Router Service ID.
      *
-     * @retval OT_ERROR_NONE       Successfully got the Backbone Router Service ID.
+     * @retval kErrorNone          Successfully got the Backbone Router Service ID.
-     * @retval OT_ERROR_NOT_FOUND  Backbone Router service doesn't exist.
+     * @retval kErrorNotFound      Backbone Router service doesn't exist.
      *
      */
-    otError GetServiceId(uint8_t &aServiceId) const;
+    Error GetServiceId(uint8_t &aServiceId) const;
 
     /**
      * This method gets the short address of the Primary Backbone Router.

src/core/backbone_router/bbr_local.cpp

@@ -125,19 +125,19 @@ void Local::GetConfig(BackboneRouterConfig &aConfig) const
     aConfig.mMlrTimeout          = mMlrTimeout;
 }
 
-otError Local::SetConfig(const BackboneRouterConfig &aConfig)
+Error Local::SetConfig(const BackboneRouterConfig &aConfig)
 {
-    otError error  = OT_ERROR_NONE;
+    Error error  = kErrorNone;
-    bool    update = false;
+    bool  update = false;
 
     VerifyOrExit(aConfig.mMlrTimeout >= Mle::kMlrTimeoutMin && aConfig.mMlrTimeout <= Mle::kMlrTimeoutMax,
-                 error = OT_ERROR_INVALID_ARGS);
+                 error = kErrorInvalidArgs);
     // Validate configuration according to Thread 1.2.1 Specification 5.21.3.3:
     // "The Reregistration Delay in seconds MUST be lower than (0.5 * MLR Timeout). It MUST be at least 1."
-    VerifyOrExit(aConfig.mReregistrationDelay >= 1, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aConfig.mReregistrationDelay >= 1, error = kErrorInvalidArgs);
     static_assert(sizeof(aConfig.mReregistrationDelay) < sizeof(aConfig.mMlrTimeout),
                   "the calculation below might overflow");
-    VerifyOrExit(aConfig.mReregistrationDelay * 2 < aConfig.mMlrTimeout, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aConfig.mReregistrationDelay * 2 < aConfig.mMlrTimeout, error = kErrorInvalidArgs);
 
     if (aConfig.mReregistrationDelay != mReregistrationDelay)
     {
@@ -169,9 +169,9 @@ exit:
     return error;
 }
 
-otError Local::AddService(bool aForce)
+Error Local::AddService(bool aForce)
 {
-    otError                                          error = OT_ERROR_INVALID_STATE;
+    Error                                            error = kErrorInvalidState;
     NetworkData::Service::BackboneRouter::ServerData serverData;
 
     VerifyOrExit(mState != OT_BACKBONE_ROUTER_STATE_DISABLED && Get<Mle::Mle>().IsAttached());
@@ -196,7 +196,7 @@ exit:
 
 void Local::RemoveService(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Get<NetworkData::Service::Manager>().Remove<NetworkData::Service::BackboneRouter>());
     mIsServiceAdded = false;
@@ -266,7 +266,7 @@ void Local::HandleBackboneRouterPrimaryUpdate(Leader::State aState, const Backbo
         mReregistrationDelay = aConfig.mReregistrationDelay;
         mMlrTimeout          = aConfig.mMlrTimeout;
         Get<Notifier>().Signal(kEventThreadBackboneRouterLocalChanged);
-        if (AddService(true /* Force registration to refresh and restore Primary state */) == OT_ERROR_NONE)
+        if (AddService(true /* Force registration to refresh and restore Primary state */) == kErrorNone)
         {
             Get<NetworkData::Notifier>().HandleServerDataUpdated();
         }
@@ -280,11 +280,11 @@ exit:
     return;
 }
 
-otError Local::GetDomainPrefix(NetworkData::OnMeshPrefixConfig &aConfig)
+Error Local::GetDomainPrefix(NetworkData::OnMeshPrefixConfig &aConfig)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(mDomainPrefixConfig.GetPrefix().GetLength() > 0, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(mDomainPrefixConfig.GetPrefix().GetLength() > 0, error = kErrorNotFound);
 
     aConfig = mDomainPrefixConfig;
 
@@ -292,12 +292,12 @@ exit:
     return error;
 }
 
-otError Local::RemoveDomainPrefix(const Ip6::Prefix &aPrefix)
+Error Local::RemoveDomainPrefix(const Ip6::Prefix &aPrefix)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(aPrefix.GetLength() > 0, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aPrefix.GetLength() > 0, error = kErrorInvalidArgs);
-    VerifyOrExit(mDomainPrefixConfig.GetPrefix() == aPrefix, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(mDomainPrefixConfig.GetPrefix() == aPrefix, error = kErrorNotFound);
 
     if (IsEnabled())
     {
@@ -318,7 +318,7 @@ void Local::SetDomainPrefix(const NetworkData::OnMeshPrefixConfig &aConfig)
     }
 
     mDomainPrefixConfig = aConfig;
-    LogDomainPrefix("Set", OT_ERROR_NONE);
+    LogDomainPrefix("Set", kErrorNone);
 
     if (IsEnabled())
     {
@@ -390,7 +390,7 @@ exit:
 
 void Local::RemoveDomainPrefixFromNetworkData(void)
 {
-    otError error = OT_ERROR_NOT_FOUND; // only used for logging.
+    Error error = kErrorNotFound; // only used for logging.
 
     if (mDomainPrefixConfig.mPrefix.mLength > 0)
     {
@@ -402,7 +402,7 @@ void Local::RemoveDomainPrefixFromNetworkData(void)
 
 void Local::AddDomainPrefixToNetworkData(void)
 {
-    otError error = OT_ERROR_NOT_FOUND; // only used for logging.
+    Error error = kErrorNotFound; // only used for logging.
 
     if (mDomainPrefixConfig.GetPrefix().GetLength() > 0)
     {
@@ -413,16 +413,16 @@ void Local::AddDomainPrefixToNetworkData(void)
 }
 
 #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_INFO) && (OPENTHREAD_CONFIG_LOG_BBR == 1)
-void Local::LogDomainPrefix(const char *aAction, otError aError)
+void Local::LogDomainPrefix(const char *aAction, Error aError)
 {
     otLogInfoBbr("%s Domain Prefix: %s, %s", aAction, mDomainPrefixConfig.GetPrefix().ToString().AsCString(),
-                 otThreadErrorToString(aError));
+                 ErrorToString(aError));
 }
 
-void Local::LogBackboneRouterService(const char *aAction, otError aError)
+void Local::LogBackboneRouterService(const char *aAction, Error aError)
 {
     otLogInfoBbr("%s BBR Service: seqno (%d), delay (%ds), timeout (%ds), %s", aAction, mSequenceNumber,
-                 mReregistrationDelay, mMlrTimeout, otThreadErrorToString(aError));
+                 mReregistrationDelay, mMlrTimeout, ErrorToString(aError));
 }
 #endif
 

src/core/backbone_router/bbr_local.hpp

@@ -114,11 +114,11 @@ public:
      *
      * @param[in]  aConfig  The configuration to set.
      *
-     * @retval OT_ERROR_NONE          Successfully updated configuration.
+     * @retval kErrorNone         Successfully updated configuration.
-     * @retval OT_ERROR_INVALID_ARGS  The configuration in @p aConfig is invalid.
+     * @retval kErrorInvalidArgs  The configuration in @p aConfig is invalid.
      *
      */
-    otError SetConfig(const BackboneRouterConfig &aConfig);
+    Error SetConfig(const BackboneRouterConfig &aConfig);
 
     /**
      * This method registers Backbone Router Dataset to Leader.
@@ -127,12 +127,12 @@ public:
      *                    False to decide based on current BackboneRouterState.
      *
      *
-     * @retval OT_ERROR_NONE             Successfully added the Service entry.
+     * @retval kErrorNone            Successfully added the Service entry.
-     * @retval OT_ERROR_INVALID_STATE    Not in the ready state to register.
+     * @retval kErrorInvalidState    Not in the ready state to register.
-     * @retval OT_ERROR_NO_BUFS          Insufficient space to add the Service entry.
+     * @retval kErrorNoBufs          Insufficient space to add the Service entry.
      *
      */
-    otError AddService(bool aForce = false);
+    Error AddService(bool aForce = false);
 
     /**
      * This method indicates whether or not the Backbone Router is Primary.
@@ -182,23 +182,23 @@ public:
      *
      * @param[out]  aConfig  A reference to the Domain Prefix configuration.
      *
-     * @retval OT_ERROR_NONE       Successfully got the Domain Prefix configuration.
+     * @retval kErrorNone      Successfully got the Domain Prefix configuration.
-     * @retval OT_ERROR_NOT_FOUND  No Domain Prefix was configured.
+     * @retval kErrorNotFound  No Domain Prefix was configured.
      *
      */
-    otError GetDomainPrefix(NetworkData::OnMeshPrefixConfig &aConfig);
+    Error GetDomainPrefix(NetworkData::OnMeshPrefixConfig &aConfig);
 
     /**
      * This method removes the local Domain Prefix configuration.
      *
      * @param[in]  aPrefix A reference to the IPv6 Domain Prefix.
      *
-     * @retval OT_ERROR_NONE          Successfully removed the Domain Prefix.
+     * @retval kErrorNone         Successfully removed the Domain Prefix.
-     * @retval OT_ERROR_INVALID_ARGS  @p aPrefix is invalid.
+     * @retval kErrorInvalidArgs  @p aPrefix is invalid.
-     * @retval OT_ERROR_NOT_FOUND     No Domain Prefix was configured or @p aPrefix doesn't match.
+     * @retval kErrorNotFound     No Domain Prefix was configured or @p aPrefix doesn't match.
      *
      */
-    otError RemoveDomainPrefix(const Ip6::Prefix &aPrefix);
+    Error RemoveDomainPrefix(const Ip6::Prefix &aPrefix);
 
     /**
      * This method sets the local Domain Prefix configuration.
@@ -253,11 +253,11 @@ private:
     void AddDomainPrefixToNetworkData(void);
     void RemoveDomainPrefixFromNetworkData(void);
 #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_INFO) && (OPENTHREAD_CONFIG_LOG_BBR == 1)
-    void LogBackboneRouterService(const char *aAction, otError aError);
+    void LogBackboneRouterService(const char *aAction, Error aError);
-    void LogDomainPrefix(const char *aAction, otError aError);
+    void LogDomainPrefix(const char *aAction, Error aError);
 #else
-    void LogBackboneRouterService(const char *, otError) {}
+    void LogBackboneRouterService(const char *, Error) {}
-    void LogDomainPrefix(const char *, otError) {}
+    void LogDomainPrefix(const char *, Error) {}
 #endif
 
     BackboneRouterState mState;

src/core/backbone_router/bbr_manager.cpp

@@ -88,7 +88,7 @@ Manager::Manager(Instance &aInstance)
 
 void Manager::HandleNotifierEvents(Events aEvents)
 {
-    otError error;
+    Error error;
 
     if (aEvents.Contains(kEventThreadBackboneRouterStateChanged))
     {
@@ -105,13 +105,13 @@ void Manager::HandleNotifierEvents(Events aEvents)
 
             error = mBackboneTmfAgent.Stop();
 
-            if (error != OT_ERROR_NONE)
+            if (error != kErrorNone)
             {
-                otLogWarnBbr("Stop Backbone TMF agent: %s", otThreadErrorToString(error));
+                otLogWarnBbr("Stop Backbone TMF agent: %s", ErrorToString(error));
             }
             else
             {
-                otLogInfoBbr("Stop Backbone TMF agent: %s", otThreadErrorToString(error));
+                otLogInfoBbr("Stop Backbone TMF agent: %s", ErrorToString(error));
             }
         }
         else
@@ -155,7 +155,7 @@ void Manager::HandleTimer(void)
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
 void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError                    error     = OT_ERROR_NONE;
+    Error                      error     = kErrorNone;
     bool                       isPrimary = Get<BackboneRouter::Local>().IsPrimary();
     ThreadStatusTlv::MlrStatus status    = ThreadStatusTlv::kMlrSuccess;
     BackboneRouterConfig       config;
@@ -171,7 +171,7 @@ void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage,
     bool         hasCommissionerSessionIdTlv = false;
     bool         processTimeoutTlv           = false;
 
-    VerifyOrExit(aMessage.IsConfirmablePostRequest(), error = OT_ERROR_PARSE);
+    VerifyOrExit(aMessage.IsConfirmablePostRequest(), error = kErrorParse);
 
 #if OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE
     // Required by Test Specification 5.10.22 DUA-TC-26, only for certification purpose
@@ -186,7 +186,7 @@ void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage,
 
     // TODO: (MLR) send configured MLR response for Reference Device
 
-    if (Tlv::Find<ThreadCommissionerSessionIdTlv>(aMessage, commissionerSessionId) == OT_ERROR_NONE)
+    if (Tlv::Find<ThreadCommissionerSessionIdTlv>(aMessage, commissionerSessionId) == kErrorNone)
     {
         const MeshCoP::CommissionerSessionIdTlv *commissionerSessionIdTlv =
             static_cast<const MeshCoP::CommissionerSessionIdTlv *>(
@@ -199,12 +199,11 @@ void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage,
         hasCommissionerSessionIdTlv = true;
     }
 
-    processTimeoutTlv =
+    processTimeoutTlv = hasCommissionerSessionIdTlv && (Tlv::Find<ThreadTimeoutTlv>(aMessage, timeout) == kErrorNone);
-        hasCommissionerSessionIdTlv && (Tlv::Find<ThreadTimeoutTlv>(aMessage, timeout) == OT_ERROR_NONE);
 
     VerifyOrExit(Tlv::FindTlvValueOffset(aMessage, IPv6AddressesTlv::kIPv6Addresses, addressesOffset,
-                                         addressesLength) == OT_ERROR_NONE,
+                                         addressesLength) == kErrorNone,
-                 error = OT_ERROR_PARSE);
+                 error = kErrorParse);
     VerifyOrExit(addressesLength % sizeof(Ip6::Address) == 0, status = ThreadStatusTlv::kMlrGeneralFailure);
     VerifyOrExit(addressesLength / sizeof(Ip6::Address) <= kIPv6AddressesNumMax,
                  status = ThreadStatusTlv::kMlrGeneralFailure);
@@ -249,16 +248,16 @@ void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage,
 
             switch (mMulticastListenersTable.Add(address, expireTime))
             {
-            case OT_ERROR_NONE:
+            case kErrorNone:
                 failed = false;
                 break;
-            case OT_ERROR_INVALID_ARGS:
+            case kErrorInvalidArgs:
                 if (status == ThreadStatusTlv::kMlrSuccess)
                 {
                     status = ThreadStatusTlv::kMlrInvalid;
                 }
                 break;
-            case OT_ERROR_NO_BUFS:
+            case kErrorNoBufs:
                 if (status == ThreadStatusTlv::kMlrSuccess)
                 {
                     status = ThreadStatusTlv::kMlrNoResources;
@@ -281,7 +280,7 @@ void Manager::HandleMulticastListenerRegistration(const Coap::Message &aMessage,
     }
 
 exit:
-    if (error == OT_ERROR_NONE)
+    if (error == kErrorNone)
     {
         SendMulticastListenerRegistrationResponse(aMessage, aMessageInfo, status, addresses, failedAddressNum);
     }
@@ -299,10 +298,10 @@ void Manager::SendMulticastListenerRegistrationResponse(const Coap::Message &
                                                         Ip6::Address *             aFailedAddresses,
                                                         uint8_t                    aFailedAddressNum)
 {
-    otError        error   = OT_ERROR_NONE;
+    Error          error   = kErrorNone;
     Coap::Message *message = nullptr;
 
-    VerifyOrExit((message = Get<Tmf::TmfAgent>().NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = Get<Tmf::TmfAgent>().NewMessage()) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(message->SetDefaultResponseHeader(aMessage));
     SuccessOrExit(message->SetPayloadMarker());
@@ -327,14 +326,14 @@ void Manager::SendMulticastListenerRegistrationResponse(const Coap::Message &
 
 exit:
     FreeMessageOnError(message, error);
-    otLogInfoBbr("Sent MLR.rsp (status=%d): %s", aStatus, otThreadErrorToString(error));
+    otLogInfoBbr("Sent MLR.rsp (status=%d): %s", aStatus, ErrorToString(error));
 }
 
 void Manager::SendBackboneMulticastListenerRegistration(const Ip6::Address *aAddresses,
                                                         uint8_t             aAddressNum,
                                                         uint32_t            aTimeout)
 {
-    otError           error   = OT_ERROR_NONE;
+    Error             error   = kErrorNone;
     Coap::Message *   message = nullptr;
     Ip6::MessageInfo  messageInfo;
     IPv6AddressesTlv  addressesTlv;
@@ -342,7 +341,7 @@ void Manager::SendBackboneMulticastListenerRegistration(const Ip6::Address *aAdd
 
     OT_ASSERT(aAddressNum >= kIPv6AddressesNumMin && aAddressNum <= kIPv6AddressesNumMax);
 
-    VerifyOrExit((message = backboneTmf.NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = backboneTmf.NewMessage()) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsNonConfirmablePost(UriPath::kBackboneMlr));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -364,14 +363,14 @@ void Manager::SendBackboneMulticastListenerRegistration(const Ip6::Address *aAdd
 
 exit:
     FreeMessageOnError(message, error);
-    otLogInfoBbr("Sent BMLR.ntf: %s", otThreadErrorToString(error));
+    otLogInfoBbr("Sent BMLR.ntf: %s", ErrorToString(error));
 }
 #endif // OPENTHREAD_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
 
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_DUA_NDPROXYING_ENABLE
 void Manager::HandleDuaRegistration(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError                    error     = OT_ERROR_NONE;
+    Error                      error     = kErrorNone;
     ThreadStatusTlv::DuaStatus status    = ThreadStatusTlv::kDuaSuccess;
     bool                       isPrimary = Get<BackboneRouter::Local>().IsPrimary();
     uint32_t                   lastTransactionTime;
@@ -382,8 +381,8 @@ void Manager::HandleDuaRegistration(const Coap::Message &aMessage, const Ip6::Me
     Coap::Code duaRespCoapCode = Coap::kCodeEmpty;
 #endif
 
-    VerifyOrExit(aMessageInfo.GetPeerAddr().GetIid().IsRoutingLocator(), error = OT_ERROR_DROP);
+    VerifyOrExit(aMessageInfo.GetPeerAddr().GetIid().IsRoutingLocator(), error = kErrorDrop);
-    VerifyOrExit(aMessage.IsConfirmablePostRequest(), error = OT_ERROR_PARSE);
+    VerifyOrExit(aMessage.IsConfirmablePostRequest(), error = kErrorParse);
 
     SuccessOrExit(error = Tlv::Find<ThreadTargetTlv>(aMessage, target));
     SuccessOrExit(error = Tlv::Find<ThreadMeshLocalEidTlv>(aMessage, meshLocalIid));
@@ -408,19 +407,19 @@ void Manager::HandleDuaRegistration(const Coap::Message &aMessage, const Ip6::Me
     VerifyOrExit(Get<BackboneRouter::Leader>().HasDomainPrefix(), status = ThreadStatusTlv::kDuaGeneralFailure);
     VerifyOrExit(Get<BackboneRouter::Leader>().IsDomainUnicast(target), status = ThreadStatusTlv::kDuaInvalid);
 
-    hasLastTransactionTime = (Tlv::Find<ThreadLastTransactionTimeTlv>(aMessage, lastTransactionTime) == OT_ERROR_NONE);
+    hasLastTransactionTime = (Tlv::Find<ThreadLastTransactionTimeTlv>(aMessage, lastTransactionTime) == kErrorNone);
 
     switch (mNdProxyTable.Register(target.GetIid(), meshLocalIid, aMessageInfo.GetPeerAddr().GetIid().GetLocator(),
                                    hasLastTransactionTime ? &lastTransactionTime : nullptr))
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         // TODO: update its EID-to-RLOC Map Cache based on the pair {DUA, RLOC16-source} which is gleaned from the
         // DUA.req packet according to Thread Spec. 5.23.3.6.2
         break;
-    case OT_ERROR_DUPLICATED:
+    case kErrorDuplicated:
         status = ThreadStatusTlv::kDuaDuplicate;
         break;
-    case OT_ERROR_NO_BUFS:
+    case kErrorNoBufs:
         status = ThreadStatusTlv::kDuaNoResources;
         break;
     default:
@@ -429,9 +428,9 @@ void Manager::HandleDuaRegistration(const Coap::Message &aMessage, const Ip6::Me
     }
 
 exit:
-    otLogInfoBbr("Received DUA.req on %s: %s", (isPrimary ? "PBBR" : "SBBR"), otThreadErrorToString(error));
+    otLogInfoBbr("Received DUA.req on %s: %s", (isPrimary ? "PBBR" : "SBBR"), ErrorToString(error));
 
-    if (error == OT_ERROR_NONE)
+    if (error == kErrorNone)
     {
 #if OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE
         if (duaRespCoapCode != Coap::kCodeEmpty)
@@ -451,10 +450,10 @@ void Manager::SendDuaRegistrationResponse(const Coap::Message &      aMessage,
                                           const Ip6::Address &       aTarget,
                                           ThreadStatusTlv::DuaStatus aStatus)
 {
-    otError        error   = OT_ERROR_NONE;
+    Error          error   = kErrorNone;
     Coap::Message *message = nullptr;
 
-    VerifyOrExit((message = Get<Tmf::TmfAgent>().NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = Get<Tmf::TmfAgent>().NewMessage()) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(message->SetDefaultResponseHeader(aMessage));
     SuccessOrExit(message->SetPayloadMarker());
@@ -467,7 +466,7 @@ void Manager::SendDuaRegistrationResponse(const Coap::Message &      aMessage,
 exit:
     FreeMessageOnError(message, error);
     otLogInfoBbr("Sent DUA.rsp for DUA %s, status %d %s", aTarget.ToString().AsCString(), aStatus,
-                 otThreadErrorToString(error));
+                 ErrorToString(error));
 }
 #endif // OPENTHREAD_CONFIG_BACKBONE_ROUTER_DUA_NDPROXYING_ENABLE
 
@@ -509,7 +508,7 @@ bool Manager::ShouldForwardDuaToBackbone(const Ip6::Address &aAddress)
 {
     bool              forwardToBackbone = false;
     Mac::ShortAddress rloc16;
-    otError           error;
+    Error             error;
 
     VerifyOrExit(Get<Local>().IsPrimary());
     VerifyOrExit(Get<Leader>().IsDomainUnicast(aAddress));
@@ -517,7 +516,7 @@ bool Manager::ShouldForwardDuaToBackbone(const Ip6::Address &aAddress)
     VerifyOrExit(!mNdProxyTable.IsRegistered(aAddress.GetIid()));
 
     error = Get<AddressResolver>().Resolve(aAddress, rloc16, /* aAllowAddressQuery */ false);
-    VerifyOrExit(error != OT_ERROR_NONE || rloc16 == Get<Mle::MleRouter>().GetRloc16());
+    VerifyOrExit(error != kErrorNone || rloc16 == Get<Mle::MleRouter>().GetRloc16());
 
     // TODO: check if the DUA is an address of any Child?
     forwardToBackbone = true;
@@ -526,15 +525,15 @@ exit:
     return forwardToBackbone;
 }
 
-otError Manager::SendBackboneQuery(const Ip6::Address &aDua, uint16_t aRloc16)
+Error Manager::SendBackboneQuery(const Ip6::Address &aDua, uint16_t aRloc16)
 {
-    otError          error   = OT_ERROR_NONE;
+    Error            error   = kErrorNone;
     Coap::Message *  message = nullptr;
     Ip6::MessageInfo messageInfo;
 
-    VerifyOrExit(Get<BackboneRouter::Local>().IsPrimary(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<BackboneRouter::Local>().IsPrimary(), error = kErrorInvalidState);
 
-    VerifyOrExit((message = mBackboneTmfAgent.NewPriorityMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = mBackboneTmfAgent.NewPriorityMessage()) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsNonConfirmablePost(UriPath::kBackboneQuery));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -556,7 +555,7 @@ otError Manager::SendBackboneQuery(const Ip6::Address &aDua, uint16_t aRloc16)
 
 exit:
     otLogInfoBbr("SendBackboneQuery for %s (rloc16=%04x): %s", aDua.ToString().AsCString(), aRloc16,
-                 otThreadErrorToString(error));
+                 ErrorToString(error));
     FreeMessageOnError(message, error);
     return error;
 }
@@ -569,31 +568,31 @@ void Manager::HandleBackboneQuery(void *aContext, otMessage *aMessage, const otM
 
 void Manager::HandleBackboneQuery(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError                error = OT_ERROR_NONE;
+    Error                  error = kErrorNone;
     Ip6::Address           dua;
     uint16_t               rloc16 = Mac::kShortAddrInvalid;
     NdProxyTable::NdProxy *ndProxy;
 
-    VerifyOrExit(aMessageInfo.IsHostInterface(), error = OT_ERROR_DROP);
+    VerifyOrExit(aMessageInfo.IsHostInterface(), error = kErrorDrop);
 
-    VerifyOrExit(Get<Local>().IsPrimary(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<Local>().IsPrimary(), error = kErrorInvalidState);
-    VerifyOrExit(aMessage.IsNonConfirmablePostRequest(), error = OT_ERROR_PARSE);
+    VerifyOrExit(aMessage.IsNonConfirmablePostRequest(), error = kErrorParse);
 
     SuccessOrExit(error = Tlv::Find<ThreadTargetTlv>(aMessage, dua));
 
     error = Tlv::Find<ThreadRloc16Tlv>(aMessage, rloc16);
-    VerifyOrExit(error == OT_ERROR_NONE || error == OT_ERROR_NOT_FOUND);
+    VerifyOrExit(error == kErrorNone || error == kErrorNotFound);
 
     otLogInfoBbr("Received BB.qry from %s for %s (rloc16=%04x)", aMessageInfo.GetPeerAddr().ToString().AsCString(),
                  dua.ToString().AsCString(), rloc16);
 
     ndProxy = mNdProxyTable.ResolveDua(dua);
-    VerifyOrExit(ndProxy != nullptr && !ndProxy->GetDadFlag(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(ndProxy != nullptr && !ndProxy->GetDadFlag(), error = kErrorNotFound);
 
     error = SendBackboneAnswer(aMessageInfo, dua, rloc16, *ndProxy);
 
 exit:
-    otLogInfoBbr("HandleBackboneQuery: %s", otThreadErrorToString(error));
+    otLogInfoBbr("HandleBackboneQuery: %s", ErrorToString(error));
 }
 
 void Manager::HandleBackboneAnswer(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)
@@ -604,7 +603,7 @@ void Manager::HandleBackboneAnswer(void *aContext, otMessage *aMessage, const ot
 
 void Manager::HandleBackboneAnswer(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError                  error = OT_ERROR_NONE;
+    Error                    error = kErrorNone;
     bool                     proactive;
     Ip6::Address             dua;
     Ip6::InterfaceIdentifier meshLocalIid;
@@ -612,10 +611,10 @@ void Manager::HandleBackboneAnswer(const Coap::Message &aMessage, const Ip6::Mes
     uint32_t                 timeSinceLastTransaction;
     uint16_t                 srcRloc16 = Mac::kShortAddrInvalid;
 
-    VerifyOrExit(aMessageInfo.IsHostInterface(), error = OT_ERROR_DROP);
+    VerifyOrExit(aMessageInfo.IsHostInterface(), error = kErrorDrop);
 
-    VerifyOrExit(Get<Local>().IsPrimary(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<Local>().IsPrimary(), error = kErrorInvalidState);
-    VerifyOrExit(aMessage.IsPostRequest(), error = OT_ERROR_PARSE);
+    VerifyOrExit(aMessage.IsPostRequest(), error = kErrorParse);
 
     proactive = !aMessage.IsConfirmable();
 
@@ -627,7 +626,7 @@ void Manager::HandleBackboneAnswer(const Coap::Message &aMessage, const Ip6::Mes
                       Tlv::FindTlvValueOffset(aMessage, ThreadTlv::kNetworkName, networkNameOffset, networkNameLength));
 
     error = Tlv::Find<ThreadRloc16Tlv>(aMessage, srcRloc16);
-    VerifyOrExit(error == OT_ERROR_NONE || error == OT_ERROR_NOT_FOUND);
+    VerifyOrExit(error == kErrorNone || error == kErrorNotFound);
 
     if (proactive)
     {
@@ -645,40 +644,40 @@ void Manager::HandleBackboneAnswer(const Coap::Message &aMessage, const Ip6::Mes
     SuccessOrExit(error = mBackboneTmfAgent.SendEmptyAck(aMessage, aMessageInfo));
 
 exit:
-    otLogInfoBbr("HandleBackboneAnswer: %s", otThreadErrorToString(error));
+    otLogInfoBbr("HandleBackboneAnswer: %s", ErrorToString(error));
 }
 
-otError Manager::SendProactiveBackboneNotification(const Ip6::Address &            aDua,
+Error Manager::SendProactiveBackboneNotification(const Ip6::Address &            aDua,
-                                                   const Ip6::InterfaceIdentifier &aMeshLocalIid,
+                                                 const Ip6::InterfaceIdentifier &aMeshLocalIid,
-                                                   uint32_t                        aTimeSinceLastTransaction)
+                                                 uint32_t                        aTimeSinceLastTransaction)
 {
     return SendBackboneAnswer(Get<BackboneRouter::Local>().GetAllDomainBackboneRoutersAddress(),
                               BackboneRouter::kBackboneUdpPort, aDua, aMeshLocalIid, aTimeSinceLastTransaction,
                               Mac::kShortAddrInvalid);
 }
 
-otError Manager::SendBackboneAnswer(const Ip6::MessageInfo &     aQueryMessageInfo,
+Error Manager::SendBackboneAnswer(const Ip6::MessageInfo &     aQueryMessageInfo,
-                                    const Ip6::Address &         aDua,
+                                  const Ip6::Address &         aDua,
-                                    uint16_t                     aSrcRloc16,
+                                  uint16_t                     aSrcRloc16,
-                                    const NdProxyTable::NdProxy &aNdProxy)
+                                  const NdProxyTable::NdProxy &aNdProxy)
 {
     return SendBackboneAnswer(aQueryMessageInfo.GetPeerAddr(), aQueryMessageInfo.GetPeerPort(), aDua,
                               aNdProxy.GetMeshLocalIid(), aNdProxy.GetTimeSinceLastTransaction(), aSrcRloc16);
 }
 
-otError Manager::SendBackboneAnswer(const Ip6::Address &            aDstAddr,
+Error Manager::SendBackboneAnswer(const Ip6::Address &            aDstAddr,
-                                    uint16_t                        aDstPort,
+                                  uint16_t                        aDstPort,
-                                    const Ip6::Address &            aDua,
+                                  const Ip6::Address &            aDua,
-                                    const Ip6::InterfaceIdentifier &aMeshLocalIid,
+                                  const Ip6::InterfaceIdentifier &aMeshLocalIid,
-                                    uint32_t                        aTimeSinceLastTransaction,
+                                  uint32_t                        aTimeSinceLastTransaction,
-                                    uint16_t                        aSrcRloc16)
+                                  uint16_t                        aSrcRloc16)
 {
-    otError          error   = OT_ERROR_NONE;
+    Error            error   = kErrorNone;
     Coap::Message *  message = nullptr;
     Ip6::MessageInfo messageInfo;
     bool             proactive = aDstAddr.IsMulticast();
 
-    VerifyOrExit((message = mBackboneTmfAgent.NewPriorityMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = mBackboneTmfAgent.NewPriorityMessage()) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->Init(proactive ? Coap::kTypeNonConfirmable : Coap::kTypeConfirmable, Coap::kCodePost,
                                         UriPath::kBackboneAnswer));
@@ -711,7 +710,7 @@ otError Manager::SendBackboneAnswer(const Ip6::Address &            aDstAddr,
 
 exit:
     otLogInfoBbr("Send %s for %s (rloc16=%04x): %s", proactive ? "PRO_BB.ntf" : "BB.ans", aDua.ToString().AsCString(),
-                 aSrcRloc16, otThreadErrorToString(error));
+                 aSrcRloc16, ErrorToString(error));
 
     FreeMessageOnError(message, error);
     return error;
@@ -719,13 +718,13 @@ exit:
 
 void Manager::HandleDadBackboneAnswer(const Ip6::Address &aDua, const Ip6::InterfaceIdentifier &aMeshLocalIid)
 {
-    otError                error     = OT_ERROR_NONE;
+    Error                  error     = kErrorNone;
     NdProxyTable::NdProxy *ndProxy   = mNdProxyTable.ResolveDua(aDua);
     bool                   duplicate = false;
 
     OT_UNUSED_VARIABLE(error);
 
-    VerifyOrExit(ndProxy != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(ndProxy != nullptr, error = kErrorNotFound);
 
     duplicate = ndProxy->GetMeshLocalIid() != aMeshLocalIid;
 
@@ -740,7 +739,7 @@ void Manager::HandleDadBackboneAnswer(const Ip6::Address &aDua, const Ip6::Inter
     ot::BackboneRouter::NdProxyTable::NotifyDadComplete(*ndProxy, duplicate);
 
 exit:
-    otLogInfoBbr("HandleDadBackboneAnswer: %s, target=%s, mliid=%s, duplicate=%s", otThreadErrorToString(error),
+    otLogInfoBbr("HandleDadBackboneAnswer: %s, target=%s, mliid=%s, duplicate=%s", ErrorToString(error),
                  aDua.ToString().AsCString(), aMeshLocalIid.ToString().AsCString(), duplicate ? "Y" : "N");
 }
 
@@ -763,12 +762,12 @@ void Manager::HandleProactiveBackboneNotification(const Ip6::Address &
                                                   const Ip6::InterfaceIdentifier &aMeshLocalIid,
                                                   uint32_t                        aTimeSinceLastTransaction)
 {
-    otError                error   = OT_ERROR_NONE;
+    Error                  error   = kErrorNone;
     NdProxyTable::NdProxy *ndProxy = mNdProxyTable.ResolveDua(aDua);
 
     OT_UNUSED_VARIABLE(error);
 
-    VerifyOrExit(ndProxy != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(ndProxy != nullptr, error = kErrorNotFound);
 
     if (ndProxy->GetMeshLocalIid() == aMeshLocalIid)
     {
@@ -792,7 +791,7 @@ void Manager::HandleProactiveBackboneNotification(const Ip6::Address &
     }
 
 exit:
-    otLogInfoBbr("HandleProactiveBackboneNotification: %s, target=%s, mliid=%s, LTT=%lds", otThreadErrorToString(error),
+    otLogInfoBbr("HandleProactiveBackboneNotification: %s, target=%s, mliid=%s, LTT=%lds", ErrorToString(error),
                  aDua.ToString().AsCString(), aMeshLocalIid.ToString().AsCString(), aTimeSinceLastTransaction);
 }
 #endif // OPENTHREAD_CONFIG_BACKBONE_ROUTER_DUA_NDPROXYING_ENABLE

src/core/backbone_router/bbr_manager.hpp

@@ -145,12 +145,12 @@ public:
      * @param[in]  aRloc16  The short address of the address resolution initiator or `Mac::kShortAddrInvalid` for
      *                      DUA DAD.
      *
-     * @retval OT_ERROR_NONE           Successfully sent BB.qry on backbone link.
+     * @retval kErrorNone          Successfully sent BB.qry on backbone link.
-     * @retval OT_ERROR_INVALID_STATE  If the Backbone Router is not primary, or not enabled.
+     * @retval kErrorInvalidState  If the Backbone Router is not primary, or not enabled.
-     * @retval OT_ERROR_NO_BUFS        If insufficient message buffers available.
+     * @retval kErrorNoBufs        If insufficient message buffers available.
      *
      */
-    otError SendBackboneQuery(const Ip6::Address &aDua, uint16_t aRloc16 = Mac::kShortAddrInvalid);
+    Error SendBackboneQuery(const Ip6::Address &aDua, uint16_t aRloc16 = Mac::kShortAddrInvalid);
 
     /**
      * This method send a Proactive Backbone Notification (PRO_BB.ntf) on the Backbone link.
@@ -159,13 +159,13 @@ public:
      * @param[in] aMeshLocalIid                 The Mesh-Local IID to notify.
      * @param[in] aTimeSinceLastTransaction     Time since last transaction (in seconds).
      *
-     * @retval OT_ERROR_NONE           Successfully sent PRO_BB.ntf on backbone link.
+     * @retval kErrorNone          Successfully sent PRO_BB.ntf on backbone link.
-     * @retval OT_ERROR_NO_BUFS        If insufficient message buffers available.
+     * @retval kErrorNoBufs        If insufficient message buffers available.
      *
      */
-    otError SendProactiveBackboneNotification(const Ip6::Address &            aDua,
+    Error SendProactiveBackboneNotification(const Ip6::Address &            aDua,
-                                              const Ip6::InterfaceIdentifier &aMeshLocalIid,
+                                            const Ip6::InterfaceIdentifier &aMeshLocalIid,
-                                              uint32_t                        aTimeSinceLastTransaction);
+                                            uint32_t                        aTimeSinceLastTransaction);
 
 private:
     enum
@@ -204,11 +204,11 @@ private:
     void        HandleBackboneQuery(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
     static void HandleBackboneAnswer(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo);
     void        HandleBackboneAnswer(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    otError     SendBackboneAnswer(const Ip6::MessageInfo &     aQueryMessageInfo,
+    Error       SendBackboneAnswer(const Ip6::MessageInfo &     aQueryMessageInfo,
                                    const Ip6::Address &         aDua,
                                    uint16_t                     aSrcRloc16,
                                    const NdProxyTable::NdProxy &aNdProxy);
-    otError     SendBackboneAnswer(const Ip6::Address &            aDstAddr,
+    Error       SendBackboneAnswer(const Ip6::Address &            aDstAddr,
                                    uint16_t                        aDstPort,
                                    const Ip6::Address &            aDua,
                                    const Ip6::InterfaceIdentifier &aMeshLocalIid,

src/core/backbone_router/multicast_listeners_table.cpp

@@ -48,11 +48,11 @@ namespace ot {
 
 namespace BackboneRouter {
 
-otError MulticastListenersTable::Add(const Ip6::Address &aAddress, Time aExpireTime)
+Error MulticastListenersTable::Add(const Ip6::Address &aAddress, Time aExpireTime)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(aAddress.IsMulticastLargerThanRealmLocal(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aAddress.IsMulticastLargerThanRealmLocal(), error = kErrorInvalidArgs);
 
     for (uint16_t i = 0; i < mNumValidListeners; i++)
     {
@@ -66,7 +66,7 @@ otError MulticastListenersTable::Add(const Ip6::Address &aAddress, Time aExpireT
         }
     }
 
-    VerifyOrExit(mNumValidListeners < OT_ARRAY_LENGTH(mListeners), error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(mNumValidListeners < OT_ARRAY_LENGTH(mListeners), error = kErrorNoBufs);
 
     mListeners[mNumValidListeners].SetAddress(aAddress);
     mListeners[mNumValidListeners].SetExpireTime(aExpireTime);
@@ -87,7 +87,7 @@ exit:
 
 void MulticastListenersTable::Remove(const Ip6::Address &aAddress)
 {
-    otError error = OT_ERROR_NOT_FOUND;
+    Error error = kErrorNotFound;
 
     for (uint16_t i = 0; i < mNumValidListeners; i++)
     {
@@ -108,7 +108,7 @@ void MulticastListenersTable::Remove(const Ip6::Address &aAddress)
                 mCallback(mCallbackContext, OT_BACKBONE_ROUTER_MULTICAST_LISTENER_REMOVED, &aAddress);
             }
 
-            ExitNow(error = OT_ERROR_NONE);
+            ExitNow(error = kErrorNone);
         }
     }
 
@@ -124,7 +124,7 @@ void MulticastListenersTable::Expire(void)
 
     while (mNumValidListeners > 0 && now >= mListeners[0].GetExpireTime())
     {
-        LogMulticastListenersTable("Expire", mListeners[0].GetAddress(), mListeners[0].GetExpireTime(), OT_ERROR_NONE);
+        LogMulticastListenersTable("Expire", mListeners[0].GetAddress(), mListeners[0].GetExpireTime(), kErrorNone);
         address = mListeners[0].GetAddress();
 
         mNumValidListeners--;
@@ -147,7 +147,7 @@ void MulticastListenersTable::Expire(void)
 void MulticastListenersTable::LogMulticastListenersTable(const char *        aAction,
                                                          const Ip6::Address &aAddress,
                                                          TimeMilli           aExpireTime,
-                                                         otError             aError)
+                                                         Error               aError)
 {
     OT_UNUSED_VARIABLE(aAction);
     OT_UNUSED_VARIABLE(aAddress);
@@ -155,7 +155,7 @@ void MulticastListenersTable::LogMulticastListenersTable(const char *        aAc
     OT_UNUSED_VARIABLE(aError);
 
     otLogDebgBbr("MulticastListenersTable: %s %s expire %u: %s", aAction, aAddress.ToString().AsCString(),
-                 aExpireTime.GetValue(), otThreadErrorToString(aError));
+                 aExpireTime.GetValue(), ErrorToString(aError));
 }
 
 void MulticastListenersTable::FixHeap(uint16_t aIndex)
@@ -287,13 +287,13 @@ void MulticastListenersTable::SetCallback(otBackboneRouterMulticastListenerCallb
     }
 }
 
-otError MulticastListenersTable::GetNext(otBackboneRouterMulticastListenerIterator &aIterator,
+Error MulticastListenersTable::GetNext(otBackboneRouterMulticastListenerIterator &aIterator,
-                                         otBackboneRouterMulticastListenerInfo &    aListenerInfo)
+                                       otBackboneRouterMulticastListenerInfo &    aListenerInfo)
 {
-    otError   error = OT_ERROR_NONE;
+    Error     error = kErrorNone;
     TimeMilli now;
 
-    VerifyOrExit(aIterator < mNumValidListeners, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(aIterator < mNumValidListeners, error = kErrorNotFound);
 
     now = TimerMilli::GetNow();
 

src/core/backbone_router/multicast_listeners_table.hpp

@@ -119,12 +119,12 @@ public:
      * @param[in] aAddress     The Multicast Listener address.
      * @param[in] aExpireTime  The Multicast Listener expire time.
      *
-     * @retval OT_ERROR_NONE          If the Multicast Listener was successfully added.
+     * @retval kErrorNone         If the Multicast Listener was successfully added.
-     * @retval OT_ERROR_INVALID_ARGS  If the Multicast Listener address was invalid.
+     * @retval kErrorInvalidArgs  If the Multicast Listener address was invalid.
-     * @retval OT_ERROR_NO_BUFS       No space available to save the Multicast Listener.
+     * @retval kErrorNoBufs       No space available to save the Multicast Listener.
      *
      */
-    otError Add(const Ip6::Address &aAddress, TimeMilli aExpireTime);
+    Error Add(const Ip6::Address &aAddress, TimeMilli aExpireTime);
 
     /**
      * This method removes a given Multicast Listener.
@@ -181,12 +181,12 @@ public:
      * @param[in] aIterator       A pointer to the Multicast Listener Iterator.
      * @param[out] aListenerInfo  A pointer to where the Multicast Listener info is placed.
      *
-     * @retval OT_ERROR_NONE        Successfully found the next Multicast Listener info.
+     * @retval kErrorNone         Successfully found the next Multicast Listener info.
-     * @retval OT_ERROR_NOT_FOUND   No subsequent Multicast Listener was found.
+     * @retval kErrorNotFound     No subsequent Multicast Listener was found.
      *
      */
-    otError GetNext(otBackboneRouterMulticastListenerIterator &aIterator,
+    Error GetNext(otBackboneRouterMulticastListenerIterator &aIterator,
-                    otBackboneRouterMulticastListenerInfo &    aListenerInfo);
+                  otBackboneRouterMulticastListenerInfo &    aListenerInfo);
 
 private:
     enum
@@ -213,7 +213,7 @@ private:
     void LogMulticastListenersTable(const char *        aAction,
                                     const Ip6::Address &aAddress,
                                     TimeMilli           aExpireTime,
-                                    otError             aError);
+                                    Error               aError);
 
     void FixHeap(uint16_t aIndex);
     bool SiftHeapElemDown(uint16_t aIndex);

src/core/backbone_router/ndproxy_table.cpp

@@ -149,18 +149,18 @@ void NdProxyTable::Clear(void)
     otLogNoteBbr("NdProxyTable::Clear!");
 }
 
-otError NdProxyTable::Register(const Ip6::InterfaceIdentifier &aAddressIid,
+Error NdProxyTable::Register(const Ip6::InterfaceIdentifier &aAddressIid,
-                               const Ip6::InterfaceIdentifier &aMeshLocalIid,
+                             const Ip6::InterfaceIdentifier &aMeshLocalIid,
-                               uint16_t                        aRloc16,
+                             uint16_t                        aRloc16,
-                               const uint32_t *                aTimeSinceLastTransaction)
+                             const uint32_t *                aTimeSinceLastTransaction)
 {
-    otError  error                    = OT_ERROR_NONE;
+    Error    error                    = kErrorNone;
     NdProxy *proxy                    = FindByAddressIid(aAddressIid);
     uint32_t timeSinceLastTransaction = aTimeSinceLastTransaction == nullptr ? 0 : *aTimeSinceLastTransaction;
 
     if (proxy != nullptr)
     {
-        VerifyOrExit(proxy->mMeshLocalIid == aMeshLocalIid, error = OT_ERROR_DUPLICATED);
+        VerifyOrExit(proxy->mMeshLocalIid == aMeshLocalIid, error = kErrorDuplicated);
 
         proxy->Update(aRloc16, timeSinceLastTransaction);
         NotifyDuaRegistrationOnBackboneLink(*proxy, /* aIsRenew */ true);
@@ -178,7 +178,7 @@ otError NdProxyTable::Register(const Ip6::InterfaceIdentifier &aAddressIid,
         proxy = FindInvalid();
 
         // TODO: evict stale DUA entries to have room for this new DUA.
-        VerifyOrExit(proxy != nullptr, error = OT_ERROR_NO_BUFS);
+        VerifyOrExit(proxy != nullptr, error = kErrorNoBufs);
     }
 
     proxy->Init(aAddressIid, aMeshLocalIid, aRloc16, timeSinceLastTransaction);
@@ -186,7 +186,7 @@ otError NdProxyTable::Register(const Ip6::InterfaceIdentifier &aAddressIid,
 
 exit:
     otLogInfoBbr("NdProxyTable::Register %s MLIID %s RLOC16 %04x LTT %u => %s", aAddressIid.ToString().AsCString(),
-                 aMeshLocalIid.ToString().AsCString(), aRloc16, timeSinceLastTransaction, otThreadErrorToString(error));
+                 aMeshLocalIid.ToString().AsCString(), aRloc16, timeSinceLastTransaction, ErrorToString(error));
     return error;
 }
 
@@ -257,7 +257,7 @@ void NdProxyTable::HandleTimer(void)
         {
             mIsAnyDadInProcess = true;
 
-            if (Get<BackboneRouter::Manager>().SendBackboneQuery(GetDua(proxy)) == OT_ERROR_NONE)
+            if (Get<BackboneRouter::Manager>().SendBackboneQuery(GetDua(proxy)) == kErrorNone)
             {
                 proxy.IncreaseDadAttampts();
             }
@@ -335,11 +335,11 @@ void NdProxyTable::NotifyDuaRegistrationOnBackboneLink(NdProxyTable::NdProxy &aN
     }
 }
 
-otError NdProxyTable::GetInfo(const Ip6::Address &aDua, otBackboneRouterNdProxyInfo &aNdProxyInfo)
+Error NdProxyTable::GetInfo(const Ip6::Address &aDua, otBackboneRouterNdProxyInfo &aNdProxyInfo)
 {
-    otError error = OT_ERROR_NOT_FOUND;
+    Error error = kErrorNotFound;
 
-    VerifyOrExit(Get<Leader>().IsDomainUnicast(aDua), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(Get<Leader>().IsDomainUnicast(aDua), error = kErrorInvalidArgs);
 
     for (NdProxy &proxy : Iterate(kFilterValid))
     {
@@ -349,7 +349,7 @@ otError NdProxyTable::GetInfo(const Ip6::Address &aDua, otBackboneRouterNdProxyI
             aNdProxyInfo.mTimeSinceLastTransaction = proxy.GetTimeSinceLastTransaction();
             aNdProxyInfo.mRloc16                   = proxy.mRloc16;
 
-            ExitNow(error = OT_ERROR_NONE);
+            ExitNow(error = kErrorNone);
         }
     }
 

src/core/backbone_router/ndproxy_table.hpp

@@ -147,15 +147,15 @@ public:
      * @param[in] aRloc16                    The RLOC16.
      * @param[in] aTimeSinceLastTransaction  Time since last transaction (in seconds).
      *
-     * @retval OT_ERROR_NONE        If registered successfully.
+     * @retval kErrorNone        If registered successfully.
-     * @retval OT_ERROR_DUPLICATED  If the Ip6 address IID is a duplicate.
+     * @retval kErrorDuplicated  If the Ip6 address IID is a duplicate.
-     * @retval OT_ERROR_NO_BUFS     Insufficient buffer space available to register.
+     * @retval kErrorNoBufs      Insufficient buffer space available to register.
      *
      */
-    otError Register(const Ip6::InterfaceIdentifier &aAddressIid,
+    Error Register(const Ip6::InterfaceIdentifier &aAddressIid,
-                     const Ip6::InterfaceIdentifier &aMeshLocalIid,
+                   const Ip6::InterfaceIdentifier &aMeshLocalIid,
-                     uint16_t                        aRloc16,
+                   uint16_t                        aRloc16,
-                     const uint32_t *                aTimeSinceLastTransaction);
+                   const uint32_t *                aTimeSinceLastTransaction);
 
     /**
      * This method checks if a given Ip6 address IID was registered.
@@ -224,11 +224,11 @@ public:
      * @param[in] aDua          The Domain Unicast Address to get info.
      * @param[in] aNdProxyInfo  A pointer to the ND Proxy info.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieve the ND Proxy info.
+     * @retval kErrorNone       Successfully retrieve the ND Proxy info.
-     * @retval OT_ERROR_NOT_FOUND  Failed to find the Domain Unicast Address in the ND Proxy table.
+     * @retval kErrorNotFound   Failed to find the Domain Unicast Address in the ND Proxy table.
      *
      */
-    otError GetInfo(const Ip6::Address &aDua, otBackboneRouterNdProxyInfo &aNdProxyInfo);
+    Error GetInfo(const Ip6::Address &aDua, otBackboneRouterNdProxyInfo &aNdProxyInfo);
 
 private:
     enum

src/core/border_router/routing_manager.cpp

@@ -82,14 +82,12 @@ RoutingManager::RoutingManager(Instance &aInstance)
     memset(mDiscoveredPrefixes, 0, sizeof(mDiscoveredPrefixes));
 }
 
-otError RoutingManager::Init(uint32_t            aInfraIfIndex,
+Error RoutingManager::Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const Ip6::Address *aInfraIfLinkLocalAddress)
-                             bool                aInfraIfIsRunning,
-                             const Ip6::Address *aInfraIfLinkLocalAddress)
 {
-    otError error;
+    Error error;
 
-    VerifyOrExit(!IsInitialized(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!IsInitialized(), error = kErrorInvalidState);
-    VerifyOrExit(aInfraIfIndex > 0, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aInfraIfIndex > 0, error = kErrorInvalidArgs);
 
     SuccessOrExit(error = LoadOrGenerateRandomOmrPrefix());
     SuccessOrExit(error = LoadOrGenerateRandomOnLinkPrefix());
@@ -100,18 +98,18 @@ otError RoutingManager::Init(uint32_t            aInfraIfIndex,
     SuccessOrExit(error = HandleInfraIfStateChanged(mInfraIfIndex, aInfraIfIsRunning, aInfraIfLinkLocalAddress));
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         mInfraIfIndex = 0;
     }
     return error;
 }
 
-otError RoutingManager::SetEnabled(bool aEnabled)
+Error RoutingManager::SetEnabled(bool aEnabled)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsInitialized(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsInitialized(), error = kErrorInvalidState);
 
     VerifyOrExit(aEnabled != mIsEnabled);
 
@@ -122,18 +120,18 @@ exit:
     return error;
 }
 
-otError RoutingManager::LoadOrGenerateRandomOmrPrefix(void)
+Error RoutingManager::LoadOrGenerateRandomOmrPrefix(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    if (Get<Settings>().ReadOmrPrefix(mLocalOmrPrefix) != OT_ERROR_NONE || !IsValidOmrPrefix(mLocalOmrPrefix))
+    if (Get<Settings>().ReadOmrPrefix(mLocalOmrPrefix) != kErrorNone || !IsValidOmrPrefix(mLocalOmrPrefix))
     {
         Ip6::NetworkPrefix randomOmrPrefix;
 
         otLogNoteBr("no valid OMR prefix found in settings, generating new one");
 
         error = randomOmrPrefix.GenerateRandomUla();
-        if (error != OT_ERROR_NONE)
+        if (error != kErrorNone)
         {
             otLogCritBr("failed to generate random OMR prefix");
             ExitNow();
@@ -147,19 +145,18 @@ exit:
     return error;
 }
 
-otError RoutingManager::LoadOrGenerateRandomOnLinkPrefix(void)
+Error RoutingManager::LoadOrGenerateRandomOnLinkPrefix(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    if (Get<Settings>().ReadOnLinkPrefix(mLocalOnLinkPrefix) != OT_ERROR_NONE ||
+    if (Get<Settings>().ReadOnLinkPrefix(mLocalOnLinkPrefix) != kErrorNone || !IsValidOnLinkPrefix(mLocalOnLinkPrefix))
-        !IsValidOnLinkPrefix(mLocalOnLinkPrefix))
     {
         Ip6::NetworkPrefix randomOnLinkPrefix;
 
         otLogNoteBr("no valid on-link prefix found in settings, generating new one");
 
         error = randomOnLinkPrefix.GenerateRandomUla();
-        if (error != OT_ERROR_NONE)
+        if (error != kErrorNone)
         {
             otLogCritBr("failed to generate random on-link prefix");
             ExitNow();
@@ -241,19 +238,19 @@ void RoutingManager::RecvIcmp6Message(uint32_t            aInfraIfIndex,
                                       const uint8_t *     aBuffer,
                                       uint16_t            aBufferLength)
 {
-    otError                  error = OT_ERROR_NONE;
+    Error                    error = kErrorNone;
     const Ip6::Icmp::Header *icmp6Header;
     const Ip6::Address *     infraLinkLocalAddr;
 
-    VerifyOrExit(IsInitialized() && mIsRunning, error = OT_ERROR_DROP);
+    VerifyOrExit(IsInitialized() && mIsRunning, error = kErrorDrop);
 
-    VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = OT_ERROR_DROP);
+    VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = kErrorDrop);
     infraLinkLocalAddr = static_cast<const Ip6::Address *>(&mInfraIfLinkLocalAddress);
 
     // Drop any ICMPv6 messages sent from myself.
-    VerifyOrExit(infraLinkLocalAddr != nullptr && aSrcAddress != *infraLinkLocalAddr, error = OT_ERROR_DROP);
+    VerifyOrExit(infraLinkLocalAddr != nullptr && aSrcAddress != *infraLinkLocalAddr, error = kErrorDrop);
 
-    VerifyOrExit(aBuffer != nullptr && aBufferLength >= sizeof(*icmp6Header), error = OT_ERROR_PARSE);
+    VerifyOrExit(aBuffer != nullptr && aBufferLength >= sizeof(*icmp6Header), error = kErrorParse);
 
     icmp6Header = reinterpret_cast<const Ip6::Icmp::Header *>(aBuffer);
 
@@ -270,21 +267,21 @@ void RoutingManager::RecvIcmp6Message(uint32_t            aInfraIfIndex,
     }
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogDebgBr("drop ICMPv6 message: %s", otThreadErrorToString(error));
+        otLogDebgBr("drop ICMPv6 message: %s", ErrorToString(error));
     }
 }
 
-otError RoutingManager::HandleInfraIfStateChanged(uint32_t            aInfraIfIndex,
+Error RoutingManager::HandleInfraIfStateChanged(uint32_t            aInfraIfIndex,
-                                                  bool                aIsRunning,
+                                                bool                aIsRunning,
-                                                  const Ip6::Address *aLinkLocalAddress)
+                                                const Ip6::Address *aLinkLocalAddress)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsInitialized(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsInitialized(), error = kErrorInvalidState);
-    VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = kErrorInvalidArgs);
-    VerifyOrExit(aLinkLocalAddress == nullptr || aLinkLocalAddress->IsLinkLocal(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aLinkLocalAddress == nullptr || aLinkLocalAddress->IsLinkLocal(), error = kErrorInvalidArgs);
 
     otLogInfoBr("infra interface state changed: %s, link-local-addr=%s", aIsRunning ? "RUNNING" : "NOT RUNNING",
                 (aLinkLocalAddress != nullptr) ? aLinkLocalAddress->ToString().AsCString() : "(null)");
@@ -333,7 +330,7 @@ uint8_t RoutingManager::EvaluateOmrPrefix(Ip6::Prefix *aNewOmrPrefixes, uint8_t
 
     OT_ASSERT(mIsRunning);
 
-    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, onMeshPrefixConfig) == OT_ERROR_NONE)
+    while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, onMeshPrefixConfig) == kErrorNone)
     {
         uint8_t newPrefixIndex;
 
@@ -377,7 +374,7 @@ uint8_t RoutingManager::EvaluateOmrPrefix(Ip6::Prefix *aNewOmrPrefixes, uint8_t
     if (newOmrPrefixNum == 0)
     {
         otLogInfoBr("EvaluateOmrPrefix: no valid OMR prefixes found in Thread network");
-        if (PublishLocalOmrPrefix() == OT_ERROR_NONE)
+        if (PublishLocalOmrPrefix() == kErrorNone)
         {
             aNewOmrPrefixes[newOmrPrefixNum++] = mLocalOmrPrefix;
         }
@@ -397,9 +394,9 @@ uint8_t RoutingManager::EvaluateOmrPrefix(Ip6::Prefix *aNewOmrPrefixes, uint8_t
     return newOmrPrefixNum;
 }
 
-otError RoutingManager::PublishLocalOmrPrefix(void)
+Error RoutingManager::PublishLocalOmrPrefix(void)
 {
-    otError                         error = OT_ERROR_NONE;
+    Error                           error = kErrorNone;
     NetworkData::OnMeshPrefixConfig omrPrefixConfig;
 
     OT_ASSERT(mIsRunning);
@@ -414,10 +411,10 @@ otError RoutingManager::PublishLocalOmrPrefix(void)
     omrPrefixConfig.mPreference   = OT_ROUTE_PREFERENCE_MED;
 
     error = Get<NetworkData::Local>().AddOnMeshPrefix(omrPrefixConfig);
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         otLogWarnBr("failed to publish local OMR prefix %s in Thread network: %s",
-                    mLocalOmrPrefix.ToString().AsCString(), otThreadErrorToString(error));
+                    mLocalOmrPrefix.ToString().AsCString(), ErrorToString(error));
     }
     else
     {
@@ -430,7 +427,7 @@ otError RoutingManager::PublishLocalOmrPrefix(void)
 
 void RoutingManager::UnpublishLocalOmrPrefix(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     VerifyOrExit(mIsRunning);
 
@@ -440,16 +437,16 @@ void RoutingManager::UnpublishLocalOmrPrefix(void)
     otLogInfoBr("unpublished local OMR prefix %s from Thread network", mLocalOmrPrefix.ToString().AsCString());
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         otLogWarnBr("failed to unpublish local OMR prefix %s from Thread network: %s",
-                    mLocalOmrPrefix.ToString().AsCString(), otThreadErrorToString(error));
+                    mLocalOmrPrefix.ToString().AsCString(), ErrorToString(error));
     }
 }
 
-otError RoutingManager::AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePreference aRoutePreference)
+Error RoutingManager::AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePreference aRoutePreference)
 {
-    otError                          error;
+    Error                            error;
     NetworkData::ExternalRouteConfig routeConfig;
 
     OT_ASSERT(mIsRunning);
@@ -460,10 +457,9 @@ otError RoutingManager::AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePref
     routeConfig.mPreference = aRoutePreference;
 
     error = Get<NetworkData::Local>().AddHasRoutePrefix(routeConfig);
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnBr("failed to add external route %s: %s", aPrefix.ToString().AsCString(),
+        otLogWarnBr("failed to add external route %s: %s", aPrefix.ToString().AsCString(), ErrorToString(error));
-                    otThreadErrorToString(error));
     }
     else
     {
@@ -476,7 +472,7 @@ otError RoutingManager::AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePref
 
 void RoutingManager::RemoveExternalRoute(const Ip6::Prefix &aPrefix)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     VerifyOrExit(mIsRunning);
 
@@ -486,10 +482,9 @@ void RoutingManager::RemoveExternalRoute(const Ip6::Prefix &aPrefix)
     otLogInfoBr("removed external route %s", aPrefix.ToString().AsCString());
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnBr("failed to remove external route %s: %s", aPrefix.ToString().AsCString(),
+        otLogWarnBr("failed to remove external route %s: %s", aPrefix.ToString().AsCString(), ErrorToString(error));
-                    otThreadErrorToString(error));
     }
 }
 
@@ -539,7 +534,7 @@ const Ip6::Prefix *RoutingManager::EvaluateOnLinkPrefix(void)
         {
             newOnLinkPrefix = mAdvertisedOnLinkPrefix;
         }
-        else if (AddExternalRoute(mLocalOnLinkPrefix, OT_ROUTE_PREFERENCE_MED) == OT_ERROR_NONE)
+        else if (AddExternalRoute(mLocalOnLinkPrefix, OT_ROUTE_PREFERENCE_MED) == kErrorNone)
         {
             newOnLinkPrefix = &mLocalOnLinkPrefix;
         }
@@ -641,7 +636,7 @@ void RoutingManager::StartRouterSolicitation(void)
     mRouterSolicitTimer.Start(randomDelay);
 }
 
-otError RoutingManager::SendRouterSolicitation(void)
+Error RoutingManager::SendRouterSolicitation(void)
 {
     Ip6::Address                    destAddress;
     RouterAdv::RouterSolicitMessage routerSolicit;
@@ -761,7 +756,7 @@ void RoutingManager::SendRouterAdvertisement(const Ip6::Prefix *aNewOmrPrefixes,
     // Send the message only when there are options.
     if (bufferLength > sizeof(routerAdv))
     {
-        otError      error;
+        Error        error;
         Ip6::Address destAddress;
 
         ++mRouterAdvertisementCount;
@@ -769,14 +764,13 @@ void RoutingManager::SendRouterAdvertisement(const Ip6::Prefix *aNewOmrPrefixes,
         destAddress.SetToLinkLocalAllNodesMulticast();
         error = otPlatInfraIfSendIcmp6Nd(mInfraIfIndex, &destAddress, buffer, bufferLength);
 
-        if (error == OT_ERROR_NONE)
+        if (error == kErrorNone)
         {
             otLogInfoBr("sent Router Advertisement on interface %u", mInfraIfIndex);
         }
         else
         {
-            otLogWarnBr("failed to send Router Advertisement on interface %u: %s", mInfraIfIndex,
+            otLogWarnBr("failed to send Router Advertisement on interface %u: %s", mInfraIfIndex, ErrorToString(error));
-                        otThreadErrorToString(error));
         }
     }
 }
@@ -832,19 +826,18 @@ void RoutingManager::HandleRouterSolicitTimer(void)
     if (mRouterSolicitCount < kMaxRtrSolicitations)
     {
         uint32_t nextSolicitationDelay;
-        otError  error;
+        Error    error;
 
         error = SendRouterSolicitation();
         ++mRouterSolicitCount;
 
-        if (error == OT_ERROR_NONE)
+        if (error == kErrorNone)
         {
             otLogDebgBr("successfully sent %uth Router Solicitation", mRouterSolicitCount);
         }
         else
         {
-            otLogCritBr("failed to send %uth Router Solicitation: %s", mRouterSolicitCount,
+            otLogCritBr("failed to send %uth Router Solicitation: %s", mRouterSolicitCount, ErrorToString(error));
-                        otThreadErrorToString(error));
         }
 
         nextSolicitationDelay =

src/core/border_router/routing_manager.hpp

@@ -47,11 +47,11 @@
 #error "OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE is required for OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE."
 #endif
 
-#include <openthread/error.h>
 #include <openthread/netdata.h>
 #include <openthread/platform/infra_if.h>
 
 #include "border_router/router_advertisement.hpp"
+#include "common/error.hpp"
 #include "common/locator.hpp"
 #include "common/notifier.hpp"
 #include "common/timer.hpp"
@@ -92,11 +92,11 @@ public:
      * @param[in]  aInfraIfLinkLocalAddress  A pointer to the IPv6 link-local address of the infrastructure
      *                                       interface. NULL if the IPv6 link-local address is missing.
      *
-     * @retval  OT_ERROR_NONE          Successfully started the routing manager.
+     * @retval  kErrorNone          Successfully started the routing manager.
-     * @retval  OT_ERROR_INVALID_ARGS  The index of the infra interface is not valid.
+     * @retval  kErrorInvalidArgs   The index of the infra interface is not valid.
      *
      */
-    otError Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const Ip6::Address *aInfraIfLinkLocalAddress);
+    Error Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const Ip6::Address *aInfraIfLinkLocalAddress);
 
     /**
      * This method enables/disables the Border Routing Manager.
@@ -105,11 +105,11 @@ public:
      *
      * @param[in]  aEnabled   A boolean to enable/disable the Border Routing Manager.
      *
-     * @retval  OT_ERROR_INVALID_STATE  The Border Routing Manager is not initialized yet.
+     * @retval  kErrorInvalidState   The Border Routing Manager is not initialized yet.
-     * @retval  OT_ERROR_NONE           Successfully enabled/disabled the Border Routing Manager.
+     * @retval  kErrorNone           Successfully enabled/disabled the Border Routing Manager.
      *
      */
-    otError SetEnabled(bool aEnabled);
+    Error SetEnabled(bool aEnabled);
 
     /**
      * This method receives an ICMPv6 message on the infrastructure interface.
@@ -136,14 +136,14 @@ public:
      * @param[in]  aLinkLocalAddress  A pointer to the IPv6 link local address of the infrastructure
      *                                interface. NULL if the IPv6 link local address is lost.
      *
-     * @retval  OT_ERROR_NONE           Successfully updated the infra interface status.
+     * @retval  kErrorNone          Successfully updated the infra interface status.
-     * @retval  OT_ERROR_INVALID_STATE  The Routing Manager is not initialized.
+     * @retval  kErrorInvalidState  The Routing Manager is not initialized.
-     * @retval  OT_ERROR_INVALID_ARGS   The @p aInfraIfIndex doesn't match the infra interface the
+     * @retval  kErrorInvalidArgs   The @p aInfraIfIndex doesn't match the infra interface the Routing Manager are
-     *                                  Routing Manager are initialized with, or the @p aLinkLocalAddress
+     *                              initialized with, or the @p aLinkLocalAddress is not a valid IPv6 link-local
-     *                                  is not a valid IPv6 link-local address.
+     *                              address.
      *
      */
-    otError HandleInfraIfStateChanged(uint32_t aInfraIfIndex, bool aIsRunning, const Ip6::Address *aLinkLocalAddress);
+    Error HandleInfraIfStateChanged(uint32_t aInfraIfIndex, bool aIsRunning, const Ip6::Address *aLinkLocalAddress);
 
 private:
     enum : uint16_t
@@ -191,25 +191,25 @@ private:
         bool        mIsOnLinkPrefix;
     };
 
-    void    EvaluateState(void);
+    void  EvaluateState(void);
-    void    Start(void);
+    void  Start(void);
-    void    Stop(void);
+    void  Stop(void);
-    void    HandleNotifierEvents(Events aEvents);
+    void  HandleNotifierEvents(Events aEvents);
-    bool    IsInitialized(void) const { return mInfraIfIndex != 0; }
+    bool  IsInitialized(void) const { return mInfraIfIndex != 0; }
-    bool    IsEnabled(void) const { return mIsEnabled; }
+    bool  IsEnabled(void) const { return mIsEnabled; }
-    otError LoadOrGenerateRandomOmrPrefix(void);
+    Error LoadOrGenerateRandomOmrPrefix(void);
-    otError LoadOrGenerateRandomOnLinkPrefix(void);
+    Error LoadOrGenerateRandomOnLinkPrefix(void);
 
     const Ip6::Prefix *EvaluateOnLinkPrefix(void);
 
     void    EvaluateRoutingPolicy(void);
     uint8_t EvaluateOmrPrefix(Ip6::Prefix *aNewOmrPrefixes, uint8_t aMaxOmrPrefixNum);
-    otError PublishLocalOmrPrefix(void);
+    Error   PublishLocalOmrPrefix(void);
     void    UnpublishLocalOmrPrefix(void);
-    otError AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePreference aRoutePreference);
+    Error   AddExternalRoute(const Ip6::Prefix &aPrefix, otRoutePreference aRoutePreference);
     void    RemoveExternalRoute(const Ip6::Prefix &aPrefix);
     void    StartRouterSolicitation(void);
-    otError SendRouterSolicitation(void);
+    Error   SendRouterSolicitation(void);
     void    SendRouterAdvertisement(const Ip6::Prefix *aNewOmrPrefixes,
                                     uint8_t            aNewOmrPrefixNum,
                                     const Ip6::Prefix *aNewOnLinkPrefix);

src/core/coap/coap.cpp

@@ -86,7 +86,7 @@ void CoapBase::ClearRequests(const Ip6::Address *aAddress)
 
         if ((aAddress == nullptr) || (metadata.mSourceAddress == *aAddress))
         {
-            FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, OT_ERROR_ABORT);
+            FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, kErrorAbort);
         }
     }
 }
@@ -138,9 +138,9 @@ exit:
     return message;
 }
 
-otError CoapBase::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError error;
+    Error error;
 
 #if OPENTHREAD_CONFIG_OTNS_ENABLE
     Get<Utils::Otns>().EmitCoapSend(static_cast<Message &>(aMessage), aMessageInfo);
@@ -149,7 +149,7 @@ otError CoapBase::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageIn
     error = mSender(*this, aMessage, aMessageInfo);
 
 #if OPENTHREAD_CONFIG_OTNS_ENABLE
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         Get<Utils::Otns>().EmitCoapSendFailure(error, static_cast<Message &>(aMessage), aMessageInfo);
     }
@@ -158,22 +158,22 @@ otError CoapBase::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageIn
 }
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-otError CoapBase::SendMessage(Message &                   aMessage,
+Error CoapBase::SendMessage(Message &                   aMessage,
-                              const Ip6::MessageInfo &    aMessageInfo,
+                            const Ip6::MessageInfo &    aMessageInfo,
-                              const TxParameters &        aTxParameters,
+                            const TxParameters &        aTxParameters,
-                              ResponseHandler             aHandler,
+                            ResponseHandler             aHandler,
-                              void *                      aContext,
+                            void *                      aContext,
-                              otCoapBlockwiseTransmitHook aTransmitHook,
+                            otCoapBlockwiseTransmitHook aTransmitHook,
-                              otCoapBlockwiseReceiveHook  aReceiveHook)
+                            otCoapBlockwiseReceiveHook  aReceiveHook)
 #else
-otError CoapBase::SendMessage(Message &               aMessage,
+Error CoapBase::SendMessage(Message &               aMessage,
-                              const Ip6::MessageInfo &aMessageInfo,
+                            const Ip6::MessageInfo &aMessageInfo,
-                              const TxParameters &    aTxParameters,
+                            const TxParameters &    aTxParameters,
-                              ResponseHandler         aHandler,
+                            ResponseHandler         aHandler,
-                              void *                  aContext)
+                            void *                  aContext)
 #endif
 {
-    otError  error;
+    Error    error;
     Message *storedCopy = nullptr;
     uint16_t copyLength = 0;
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
@@ -187,12 +187,12 @@ otError CoapBase::SendMessage(Message &               aMessage,
     case kTypeAck:
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
         // Check for block-wise transfer
-        if ((aTransmitHook != nullptr) && (aMessage.ReadBlockOptionValues(kOptionBlock2) == OT_ERROR_NONE) &&
+        if ((aTransmitHook != nullptr) && (aMessage.ReadBlockOptionValues(kOptionBlock2) == kErrorNone) &&
             (aMessage.GetBlockWiseBlockNumber() == 0))
         {
             // Set payload for first block of the transfer
             VerifyOrExit((bufLen = otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize())) <= kMaxBlockLength,
-                         error = OT_ERROR_NO_BUFS);
+                         error = kErrorNoBufs);
             SuccessOrExit(error = aTransmitHook(aContext, buf, aMessage.GetBlockWiseBlockNumber() * bufLen, &bufLen,
                                                 &moreBlocks));
             SuccessOrExit(error = aMessage.AppendBytes(buf, bufLen));
@@ -209,12 +209,12 @@ otError CoapBase::SendMessage(Message &               aMessage,
     default:
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
         // Check for block-wise transfer
-        if ((aTransmitHook != nullptr) && (aMessage.ReadBlockOptionValues(kOptionBlock1) == OT_ERROR_NONE) &&
+        if ((aTransmitHook != nullptr) && (aMessage.ReadBlockOptionValues(kOptionBlock1) == kErrorNone) &&
             (aMessage.GetBlockWiseBlockNumber() == 0))
         {
             // Set payload for first block of the transfer
             VerifyOrExit((bufLen = otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize())) <= kMaxBlockLength,
-                         error = OT_ERROR_NO_BUFS);
+                         error = kErrorNoBufs);
             SuccessOrExit(error = aTransmitHook(aContext, buf, aMessage.GetBlockWiseBlockNumber() * bufLen, &bufLen,
                                                 &moreBlocks));
             SuccessOrExit(error = aMessage.AppendBytes(buf, bufLen));
@@ -275,7 +275,7 @@ otError CoapBase::SendMessage(Message &               aMessage,
                 Message *origRequest = FindRelatedRequest(aMessage, aMessageInfo, handlerMetadata);
                 if (origRequest != nullptr)
                 {
-                    FinalizeCoapTransaction(*origRequest, handlerMetadata, nullptr, nullptr, OT_ERROR_NONE);
+                    FinalizeCoapTransaction(*origRequest, handlerMetadata, nullptr, nullptr, kErrorNone);
                 }
             }
         }
@@ -307,14 +307,14 @@ otError CoapBase::SendMessage(Message &               aMessage,
             (metadata.mConfirmable ? metadata.mRetransmissionTimeout : aTxParameters.CalculateMaxTransmitWait());
 
         storedCopy = CopyAndEnqueueMessage(aMessage, copyLength, metadata);
-        VerifyOrExit(storedCopy != nullptr, error = OT_ERROR_NO_BUFS);
+        VerifyOrExit(storedCopy != nullptr, error = kErrorNoBufs);
     }
 
     SuccessOrExit(error = Send(aMessage, aMessageInfo));
 
 exit:
 
-    if (error != OT_ERROR_NONE && storedCopy != nullptr)
+    if (error != kErrorNone && storedCopy != nullptr)
     {
         DequeueMessage(*storedCopy);
     }
@@ -322,10 +322,10 @@ exit:
     return error;
 }
 
-otError CoapBase::SendMessage(Message &               aMessage,
+Error CoapBase::SendMessage(Message &               aMessage,
-                              const Ip6::MessageInfo &aMessageInfo,
+                            const Ip6::MessageInfo &aMessageInfo,
-                              ResponseHandler         aHandler,
+                            ResponseHandler         aHandler,
-                              void *                  aContext)
+                            void *                  aContext)
 {
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     return SendMessage(aMessage, aMessageInfo, TxParameters::GetDefault(), aHandler, aContext, nullptr, nullptr);
@@ -334,34 +334,34 @@ otError CoapBase::SendMessage(Message &               aMessage,
 #endif
 }
 
-otError CoapBase::SendReset(Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::SendReset(Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
 {
     return SendEmptyMessage(kTypeReset, aRequest, aMessageInfo);
 }
 
-otError CoapBase::SendAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::SendAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
 {
     return SendEmptyMessage(kTypeAck, aRequest, aMessageInfo);
 }
 
-otError CoapBase::SendEmptyAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Code aCode)
+Error CoapBase::SendEmptyAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Code aCode)
 {
-    return (aRequest.IsConfirmable() ? SendHeaderResponse(aCode, aRequest, aMessageInfo) : OT_ERROR_INVALID_ARGS);
+    return (aRequest.IsConfirmable() ? SendHeaderResponse(aCode, aRequest, aMessageInfo) : kErrorInvalidArgs);
 }
 
-otError CoapBase::SendNotFound(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::SendNotFound(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
 {
     return SendHeaderResponse(kCodeNotFound, aRequest, aMessageInfo);
 }
 
-otError CoapBase::SendEmptyMessage(Type aType, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::SendEmptyMessage(Type aType, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError  error   = OT_ERROR_NONE;
+    Error    error   = kErrorNone;
     Message *message = nullptr;
 
-    VerifyOrExit(aRequest.IsConfirmable(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aRequest.IsConfirmable(), error = kErrorInvalidArgs);
 
-    VerifyOrExit((message = NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMessage()) != nullptr, error = kErrorNoBufs);
 
     message->Init(aType, kCodeEmpty);
     message->SetMessageId(aRequest.GetMessageId());
@@ -374,13 +374,13 @@ exit:
     return error;
 }
 
-otError CoapBase::SendHeaderResponse(Message::Code aCode, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+Error CoapBase::SendHeaderResponse(Message::Code aCode, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError  error   = OT_ERROR_NONE;
+    Error    error   = kErrorNone;
     Message *message = nullptr;
 
-    VerifyOrExit(aRequest.IsRequest(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aRequest.IsRequest(), error = kErrorInvalidArgs);
-    VerifyOrExit((message = NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMessage()) != nullptr, error = kErrorNoBufs);
 
     switch (aRequest.GetType())
     {
@@ -394,7 +394,7 @@ otError CoapBase::SendHeaderResponse(Message::Code aCode, const Message &aReques
         break;
 
     default:
-        ExitNow(error = OT_ERROR_INVALID_ARGS);
+        ExitNow(error = kErrorInvalidArgs);
         OT_UNREACHABLE_CODE(break);
     }
 
@@ -439,7 +439,7 @@ void CoapBase::HandleRetransmissionTimer(void)
             if (!metadata.mConfirmable || (metadata.mRetransmissionsRemaining == 0))
             {
                 // No expected response or acknowledgment.
-                FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, OT_ERROR_RESPONSE_TIMEOUT);
+                FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, kErrorResponseTimeout);
                 continue;
             }
 
@@ -481,7 +481,7 @@ void CoapBase::FinalizeCoapTransaction(Message &               aRequest,
                                        const Metadata &        aMetadata,
                                        Message *               aResponse,
                                        const Ip6::MessageInfo *aMessageInfo,
-                                       otError                 aResult)
+                                       Error                   aResult)
 {
     DequeueMessage(aRequest);
 
@@ -491,9 +491,9 @@ void CoapBase::FinalizeCoapTransaction(Message &               aRequest,
     }
 }
 
-otError CoapBase::AbortTransaction(ResponseHandler aHandler, void *aContext)
+Error CoapBase::AbortTransaction(ResponseHandler aHandler, void *aContext)
 {
-    otError  error = OT_ERROR_NOT_FOUND;
+    Error    error = kErrorNotFound;
     Message *nextMessage;
     Metadata metadata;
 
@@ -504,8 +504,8 @@ otError CoapBase::AbortTransaction(ResponseHandler aHandler, void *aContext)
 
         if (metadata.mResponseHandler == aHandler && metadata.mResponseContext == aContext)
         {
-            FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, OT_ERROR_ABORT);
+            FinalizeCoapTransaction(*message, metadata, nullptr, nullptr, kErrorAbort);
-            error = OT_ERROR_NONE;
+            error = kErrorNone;
         }
     }
 
@@ -514,10 +514,10 @@ otError CoapBase::AbortTransaction(ResponseHandler aHandler, void *aContext)
 
 Message *CoapBase::CopyAndEnqueueMessage(const Message &aMessage, uint16_t aCopyLength, const Metadata &aMetadata)
 {
-    otError  error       = OT_ERROR_NONE;
+    Error    error       = kErrorNone;
     Message *messageCopy = nullptr;
 
-    VerifyOrExit((messageCopy = aMessage.Clone(aCopyLength)) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((messageCopy = aMessage.Clone(aCopyLength)) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = aMetadata.AppendTo(*messageCopy));
 
@@ -555,27 +555,27 @@ void CoapBase::FreeLastBlockResponse(void)
     }
 }
 
-otError CoapBase::CacheLastBlockResponse(Message *aResponse)
+Error CoapBase::CacheLastBlockResponse(Message *aResponse)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
     // Save last response for block-wise transfer
     FreeLastBlockResponse();
 
     if ((mLastResponse = aResponse->Clone()) == nullptr)
     {
-        error = OT_ERROR_NO_BUFS;
+        error = kErrorNoBufs;
     }
 
     return error;
 }
 
-otError CoapBase::PrepareNextBlockRequest(Message::BlockType aType,
+Error CoapBase::PrepareNextBlockRequest(Message::BlockType aType,
-                                          bool               aMoreBlocks,
+                                        bool               aMoreBlocks,
-                                          Message &          aRequestOld,
+                                        Message &          aRequestOld,
-                                          Message &          aRequest,
+                                        Message &          aRequest,
-                                          Message &          aMessage)
+                                        Message &          aMessage)
 {
-    otError          error       = OT_ERROR_NONE;
+    Error            error       = kErrorNone;
     bool             isOptionSet = false;
     uint64_t         optionBuf   = 0;
     uint16_t         blockOption = 0;
@@ -633,12 +633,12 @@ exit:
     return error;
 }
 
-otError CoapBase::SendNextBlock1Request(Message &               aRequest,
+Error CoapBase::SendNextBlock1Request(Message &               aRequest,
-                                        Message &               aMessage,
+                                      Message &               aMessage,
-                                        const Ip6::MessageInfo &aMessageInfo,
+                                      const Ip6::MessageInfo &aMessageInfo,
-                                        const Metadata &        aCoapMetadata)
+                                      const Metadata &        aCoapMetadata)
 {
-    otError  error                = OT_ERROR_NONE;
+    Error    error                = kErrorNone;
     Message *request              = nullptr;
     bool     moreBlocks           = false;
     uint8_t  buf[kMaxBlockLength] = {0};
@@ -650,13 +650,13 @@ otError CoapBase::SendNextBlock1Request(Message &               aRequest,
     // Conclude block-wise transfer if last block has been received
     if (!aRequest.IsMoreBlocksFlagSet())
     {
-        FinalizeCoapTransaction(aRequest, aCoapMetadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+        FinalizeCoapTransaction(aRequest, aCoapMetadata, &aMessage, &aMessageInfo, kErrorNone);
         ExitNow();
     }
 
     // Get next block
     VerifyOrExit((bufLen = otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize())) <= kMaxBlockLength,
-                 error = OT_ERROR_NO_BUFS);
+                 error = kErrorNoBufs);
 
     SuccessOrExit(
         error = aCoapMetadata.mBlockwiseTransmitHook(aCoapMetadata.mResponseContext, buf,
@@ -665,11 +665,10 @@ otError CoapBase::SendNextBlock1Request(Message &               aRequest,
                                                      &bufLen, &moreBlocks));
 
     // Check if block length is valid
-    VerifyOrExit(bufLen <= otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()),
+    VerifyOrExit(bufLen <= otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()), error = kErrorInvalidArgs);
-                 error = OT_ERROR_INVALID_ARGS);
 
     // Init request for next block
-    VerifyOrExit((request = NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((request = NewMessage()) != nullptr, error = kErrorNoBufs);
     SuccessOrExit(error = PrepareNextBlockRequest(Message::kBlockType1, moreBlocks, aRequest, *request, aMessage));
 
     SuccessOrExit(error = request->SetPayloadMarker());
@@ -691,14 +690,14 @@ exit:
     return error;
 }
 
-otError CoapBase::SendNextBlock2Request(Message &               aRequest,
+Error CoapBase::SendNextBlock2Request(Message &               aRequest,
-                                        Message &               aMessage,
+                                      Message &               aMessage,
-                                        const Ip6::MessageInfo &aMessageInfo,
+                                      const Ip6::MessageInfo &aMessageInfo,
-                                        const Metadata &        aCoapMetadata,
+                                      const Metadata &        aCoapMetadata,
-                                        uint32_t                aTotalLength,
+                                      uint32_t                aTotalLength,
-                                        bool                    aBeginBlock1Transfer)
+                                      bool                    aBeginBlock1Transfer)
 {
-    otError  error                = OT_ERROR_NONE;
+    Error    error                = kErrorNone;
     Message *request              = nullptr;
     uint8_t  buf[kMaxBlockLength] = {0};
     uint16_t bufLen               = kMaxBlockLength;
@@ -709,7 +708,7 @@ otError CoapBase::SendNextBlock2Request(Message &               aRequest,
     VerifyOrExit((aMessage.GetLength() - aMessage.GetOffset()) <=
                          otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()) &&
                      (aMessage.GetLength() - aMessage.GetOffset()) <= kMaxBlockLength,
-                 error = OT_ERROR_NO_BUFS);
+                 error = kErrorNoBufs);
 
     // Read and then forward payload to receive hook function
     bufLen = aMessage.ReadBytes(aMessage.GetOffset(), buf, aMessage.GetLength() - aMessage.GetOffset());
@@ -726,12 +725,12 @@ otError CoapBase::SendNextBlock2Request(Message &               aRequest,
     // Conclude block-wise transfer if last block has been received
     if (!aMessage.IsMoreBlocksFlagSet())
     {
-        FinalizeCoapTransaction(aRequest, aCoapMetadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+        FinalizeCoapTransaction(aRequest, aCoapMetadata, &aMessage, &aMessageInfo, kErrorNone);
         ExitNow();
     }
 
     // Init request for next block
-    VerifyOrExit((request = NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((request = NewMessage()) != nullptr, error = kErrorNoBufs);
     SuccessOrExit(error = PrepareNextBlockRequest(Message::kBlockType2, aMessage.IsMoreBlocksFlagSet(), aRequest,
                                                   *request, aMessage));
 
@@ -753,12 +752,12 @@ exit:
     return error;
 }
 
-otError CoapBase::ProcessBlock1Request(Message &                aMessage,
+Error CoapBase::ProcessBlock1Request(Message &                aMessage,
-                                       const Ip6::MessageInfo & aMessageInfo,
+                                     const Ip6::MessageInfo & aMessageInfo,
-                                       const ResourceBlockWise &aResource,
+                                     const ResourceBlockWise &aResource,
-                                       uint32_t                 aTotalLength)
+                                     uint32_t                 aTotalLength)
 {
-    otError  error                = OT_ERROR_NONE;
+    Error    error                = kErrorNone;
     Message *response             = nullptr;
     uint8_t  buf[kMaxBlockLength] = {0};
     uint16_t bufLen               = kMaxBlockLength;
@@ -766,7 +765,7 @@ otError CoapBase::ProcessBlock1Request(Message &                aMessage,
     SuccessOrExit(error = aMessage.ReadBlockOptionValues(kOptionBlock1));
 
     // Read and then forward payload to receive hook function
-    VerifyOrExit((aMessage.GetLength() - aMessage.GetOffset()) <= kMaxBlockLength, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((aMessage.GetLength() - aMessage.GetOffset()) <= kMaxBlockLength, error = kErrorNoBufs);
     bufLen = aMessage.ReadBytes(aMessage.GetOffset(), buf, aMessage.GetLength() - aMessage.GetOffset());
     SuccessOrExit(error = aResource.HandleBlockReceive(buf,
                                                        otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()) *
@@ -776,7 +775,7 @@ otError CoapBase::ProcessBlock1Request(Message &                aMessage,
     if (aMessage.IsMoreBlocksFlagSet())
     {
         // Set up next response
-        VerifyOrExit((response = NewMessage()) != nullptr, error = OT_ERROR_FAILED);
+        VerifyOrExit((response = NewMessage()) != nullptr, error = kErrorFailed);
         response->Init(kTypeAck, kCodeContinue);
         response->SetMessageId(aMessage.GetMessageId());
         IgnoreReturnValue(
@@ -797,17 +796,17 @@ otError CoapBase::ProcessBlock1Request(Message &                aMessage,
 
         SuccessOrExit(error = SendMessage(*response, aMessageInfo));
 
-        error = OT_ERROR_BUSY;
+        error = kErrorBusy;
     }
     else
     {
         // Conclude block-wise transfer if last block has been received
         FreeLastBlockResponse();
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
     }
 
 exit:
-    if (error != OT_ERROR_NONE && error != OT_ERROR_BUSY && response != nullptr)
+    if (error != kErrorNone && error != kErrorBusy && response != nullptr)
     {
         response->Free();
     }
@@ -815,11 +814,11 @@ exit:
     return error;
 }
 
-otError CoapBase::ProcessBlock2Request(Message &                aMessage,
+Error CoapBase::ProcessBlock2Request(Message &                aMessage,
-                                       const Ip6::MessageInfo & aMessageInfo,
+                                     const Ip6::MessageInfo & aMessageInfo,
-                                       const ResourceBlockWise &aResource)
+                                     const ResourceBlockWise &aResource)
 {
-    otError          error                = OT_ERROR_NONE;
+    Error            error                = kErrorNone;
     Message *        response             = nullptr;
     uint8_t          buf[kMaxBlockLength] = {0};
     uint16_t         bufLen               = kMaxBlockLength;
@@ -839,12 +838,12 @@ otError CoapBase::ProcessBlock2Request(Message &                aMessage,
     }
 
     // Set up next response
-    VerifyOrExit((response = NewMessage()) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((response = NewMessage()) != nullptr, error = kErrorNoBufs);
     response->Init(kTypeAck, kCodeContent);
     response->SetMessageId(aMessage.GetMessageId());
 
     VerifyOrExit((bufLen = otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize())) <= kMaxBlockLength,
-                 error = OT_ERROR_NO_BUFS);
+                 error = kErrorNoBufs);
     SuccessOrExit(error = aResource.HandleBlockTransmit(buf,
                                                         otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()) *
                                                             aMessage.GetBlockWiseBlockNumber(),
@@ -877,7 +876,7 @@ otError CoapBase::ProcessBlock2Request(Message &                aMessage,
             response->SetBlockWiseBlockSize(OT_COAP_OPTION_BLOCK_SZX_16);
             break;
         default:
-            error = OT_ERROR_INVALID_ARGS;
+            error = kErrorInvalidArgs;
             ExitNow();
             break;
         }
@@ -886,7 +885,7 @@ otError CoapBase::ProcessBlock2Request(Message &                aMessage,
     {
         // Verify that buffer length is not larger than requested block size
         VerifyOrExit(bufLen <= otCoapBlockSizeFromExponent(aMessage.GetBlockWiseBlockSize()),
-                     error = OT_ERROR_INVALID_ARGS);
+                     error = kErrorInvalidArgs);
         response->SetBlockWiseBlockSize(aMessage.GetBlockWiseBlockSize());
     }
 
@@ -943,20 +942,20 @@ exit:
 
 void CoapBase::SendCopy(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError  error;
+    Error    error;
     Message *messageCopy = nullptr;
 
     // Create a message copy for lower layers.
     messageCopy = aMessage.Clone(aMessage.GetLength() - sizeof(Metadata));
-    VerifyOrExit(messageCopy != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(messageCopy != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = Send(*messageCopy, aMessageInfo));
 
 exit:
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnCoap("Failed to send copy: %s", otThreadErrorToString(error));
+        otLogWarnCoap("Failed to send copy: %s", ErrorToString(error));
         FreeMessage(messageCopy);
     }
 }
@@ -1007,7 +1006,7 @@ void CoapBase::Receive(ot::Message &aMessage, const Ip6::MessageInfo &aMessageIn
 {
     Message &message = static_cast<Message &>(aMessage);
 
-    if (message.ParseHeader() != OT_ERROR_NONE)
+    if (message.ParseHeader() != kErrorNone)
     {
         otLogDebgCoap("Failed to parse CoAP header");
 
@@ -1034,7 +1033,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
 {
     Metadata metadata;
     Message *request = nullptr;
-    otError  error   = OT_ERROR_NONE;
+    Error    error   = kErrorNone;
 #if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE
     bool responseObserve = false;
 #endif
@@ -1062,7 +1061,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
     case kTypeReset:
         if (aMessage.IsEmpty())
         {
-            FinalizeCoapTransaction(*request, metadata, nullptr, nullptr, OT_ERROR_ABORT);
+            FinalizeCoapTransaction(*request, metadata, nullptr, nullptr, kErrorAbort);
         }
 
         // Silently ignore non-empty reset messages (RFC 7252, p. 4.2).
@@ -1078,7 +1077,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                 // This is the ACK to our RFC7641 notification.  There will be no
                 // "separate" response so pass it back as if it were a piggy-backed
                 // response so we can stop re-sending and the application can move on.
-                FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+                FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, kErrorNone);
             }
             else
 #endif
@@ -1109,7 +1108,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
             if (metadata.mObserve && responseObserve && (metadata.mResponseHandler != nullptr))
             {
                 // This is a RFC7641 notification.  The request is *not* done!
-                metadata.mResponseHandler(metadata.mResponseContext, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+                metadata.mResponseHandler(metadata.mResponseContext, &aMessage, &aMessageInfo, kErrorNone);
 
                 // Consider the message acknowledged at this point.
                 metadata.mAcknowledged = true;
@@ -1153,7 +1152,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                 {
                 case 0:
                     // Piggybacked response.
-                    FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+                    FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, kErrorNone);
                     break;
                 case 1: // Block1 option
                     if (aMessage.GetCode() == kCodeContinue && metadata.mBlockwiseTransmitHook != nullptr)
@@ -1162,7 +1161,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                     }
 
                     if (aMessage.GetCode() != kCodeContinue || metadata.mBlockwiseTransmitHook == nullptr ||
-                        error != OT_ERROR_NONE)
+                        error != kErrorNone)
                     {
                         FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, error);
                     }
@@ -1175,7 +1174,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                     }
 
                     if (aMessage.GetCode() >= kCodeBadRequest || metadata.mBlockwiseReceiveHook == nullptr ||
-                        error != OT_ERROR_NONE)
+                        error != kErrorNone)
                     {
                         FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, error);
                     }
@@ -1190,14 +1189,14 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                     FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, error);
                     break;
                 default:
-                    error = OT_ERROR_ABORT;
+                    error = kErrorAbort;
                     FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, error);
                     break;
                 }
             }
 #else  // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
             {
-                FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+                FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, kErrorNone);
             }
 #endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
         }
@@ -1223,11 +1222,11 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
                                                            ))
         {
             // If multicast non-confirmable request, allow multiple responses
-            metadata.mResponseHandler(metadata.mResponseContext, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+            metadata.mResponseHandler(metadata.mResponseContext, &aMessage, &aMessageInfo, kErrorNone);
         }
         else
         {
-            FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, OT_ERROR_NONE);
+            FinalizeCoapTransaction(*request, metadata, &aMessage, &aMessageInfo, kErrorNone);
         }
 
         break;
@@ -1235,7 +1234,7 @@ void CoapBase::ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo
 
 exit:
 
-    if (error == OT_ERROR_NONE && request == nullptr)
+    if (error == kErrorNone && request == nullptr)
     {
         if (aMessage.IsConfirmable() || aMessage.IsNonConfirmable())
         {
@@ -1250,7 +1249,7 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
 {
     char     uriPath[Message::kMaxReceivedUriPath + 1];
     Message *cachedResponse = nullptr;
-    otError  error          = OT_ERROR_NOT_FOUND;
+    Error    error          = kErrorNotFound;
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     Option::Iterator iterator;
     char *           curUriPath         = uriPath;
@@ -1265,16 +1264,16 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
 
     switch (mResponsesQueue.GetMatchedResponseCopy(aMessage, aMessageInfo, &cachedResponse))
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         cachedResponse->Finish();
         error = Send(*cachedResponse, aMessageInfo);
 
         OT_FALL_THROUGH;
 
-    case OT_ERROR_NO_BUFS:
+    case kErrorNoBufs:
         ExitNow();
 
-    case OT_ERROR_NOT_FOUND:
+    case kErrorNotFound:
     default:
         break;
     }
@@ -1292,8 +1291,7 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
                 *curUriPath++ = '/';
             }
 
-            VerifyOrExit(curUriPath + iterator.GetOption()->GetLength() < OT_ARRAY_END(uriPath),
+            VerifyOrExit(curUriPath + iterator.GetOption()->GetLength() < OT_ARRAY_END(uriPath), error = kErrorParse);
-                         error = OT_ERROR_PARSE);
 
             IgnoreError(iterator.ReadOptionValue(curUriPath));
             curUriPath += iterator.GetOption()->GetLength();
@@ -1337,23 +1335,23 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
                 {
                     switch (ProcessBlock1Request(aMessage, aMessageInfo, *resource, totalTransfereSize))
                     {
-                    case OT_ERROR_NONE:
+                    case kErrorNone:
                         resource->HandleRequest(aMessage, aMessageInfo);
                         // Fall through
-                    case OT_ERROR_BUSY:
+                    case kErrorBusy:
-                        error = OT_ERROR_NONE;
+                        error = kErrorNone;
                         break;
-                    case OT_ERROR_NO_BUFS:
+                    case kErrorNoBufs:
                         IgnoreReturnValue(SendHeaderResponse(kCodeRequestTooLarge, aMessage, aMessageInfo));
-                        error = OT_ERROR_DROP;
+                        error = kErrorDrop;
                         break;
-                    case OT_ERROR_NO_FRAME_RECEIVED:
+                    case kErrorNoFrameReceived:
                         IgnoreReturnValue(SendHeaderResponse(kCodeRequestIncomplete, aMessage, aMessageInfo));
-                        error = OT_ERROR_DROP;
+                        error = kErrorDrop;
                         break;
                     default:
                         IgnoreReturnValue(SendHeaderResponse(kCodeInternalError, aMessage, aMessageInfo));
-                        error = OT_ERROR_DROP;
+                        error = kErrorDrop;
                         break;
                     }
                 }
@@ -1361,10 +1359,10 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
             case 2:
                 if (resource->mTransmitHook != nullptr)
                 {
-                    if ((error = ProcessBlock2Request(aMessage, aMessageInfo, *resource)) != OT_ERROR_NONE)
+                    if ((error = ProcessBlock2Request(aMessage, aMessageInfo, *resource)) != kErrorNone)
                     {
                         IgnoreReturnValue(SendHeaderResponse(kCodeInternalError, aMessage, aMessageInfo));
-                        error = OT_ERROR_DROP;
+                        error = kErrorDrop;
                     }
                 }
                 break;
@@ -1374,7 +1372,7 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
         else
         {
             resource->HandleRequest(aMessage, aMessageInfo);
-            error = OT_ERROR_NONE;
+            error = kErrorNone;
             ExitNow();
         }
     }
@@ -1387,7 +1385,7 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
         if (strcmp(resource->mUriPath, uriPath) == 0)
         {
             resource->HandleRequest(aMessage, aMessageInfo);
-            error = OT_ERROR_NONE;
+            error = kErrorNone;
             ExitNow();
         }
     }
@@ -1395,16 +1393,16 @@ void CoapBase::ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo
     if (mDefaultHandler)
     {
         mDefaultHandler(mDefaultHandlerContext, &aMessage, &aMessageInfo);
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
     }
 
 exit:
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogInfoCoap("Failed to process request: %s", otThreadErrorToString(error));
+        otLogInfoCoap("Failed to process request: %s", ErrorToString(error));
 
-        if (error == OT_ERROR_NOT_FOUND && !aMessageInfo.GetSockAddr().IsMulticast())
+        if (error == kErrorNotFound && !aMessageInfo.GetSockAddr().IsMulticast())
         {
             IgnoreError(SendNotFound(aMessage, aMessageInfo));
         }
@@ -1431,18 +1429,18 @@ ResponsesQueue::ResponsesQueue(Instance &aInstance)
 {
 }
 
-otError ResponsesQueue::GetMatchedResponseCopy(const Message &         aRequest,
+Error ResponsesQueue::GetMatchedResponseCopy(const Message &         aRequest,
-                                               const Ip6::MessageInfo &aMessageInfo,
+                                             const Ip6::MessageInfo &aMessageInfo,
-                                               Message **              aResponse)
+                                             Message **              aResponse)
 {
-    otError        error = OT_ERROR_NONE;
+    Error          error = kErrorNone;
     const Message *cacheResponse;
 
     cacheResponse = FindMatchedResponse(aRequest, aMessageInfo);
-    VerifyOrExit(cacheResponse != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(cacheResponse != nullptr, error = kErrorNotFound);
 
     *aResponse = cacheResponse->Clone(cacheResponse->GetLength() - sizeof(ResponseMetadata));
-    VerifyOrExit(*aResponse != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(*aResponse != nullptr, error = kErrorNoBufs);
 
 exit:
     return error;
@@ -1487,7 +1485,7 @@ void ResponsesQueue::EnqueueResponse(Message &               aMessage,
 
     VerifyOrExit((responseCopy = aMessage.Clone()) != nullptr);
 
-    VerifyOrExit(metadata.AppendTo(*responseCopy) == OT_ERROR_NONE, responseCopy->Free());
+    VerifyOrExit(metadata.AppendTo(*responseCopy) == kErrorNone, responseCopy->Free());
 
     mQueue.Enqueue(*responseCopy);
 
@@ -1658,10 +1656,10 @@ Coap::Coap(Instance &aInstance)
 {
 }
 
-otError Coap::Start(uint16_t aPort, otNetifIdentifier aNetifIdentifier)
+Error Coap::Start(uint16_t aPort, otNetifIdentifier aNetifIdentifier)
 {
-    otError error        = OT_ERROR_NONE;
+    Error error        = kErrorNone;
-    bool    socketOpened = false;
+    bool  socketOpened = false;
 
     VerifyOrExit(!mSocket.IsBound());
 
@@ -1672,7 +1670,7 @@ otError Coap::Start(uint16_t aPort, otNetifIdentifier aNetifIdentifier)
     SuccessOrExit(error = mSocket.Bind(aPort));
 
 exit:
-    if (error != OT_ERROR_NONE && socketOpened)
+    if (error != kErrorNone && socketOpened)
     {
         IgnoreError(mSocket.Close());
     }
@@ -1680,9 +1678,9 @@ exit:
     return error;
 }
 
-otError Coap::Stop(void)
+Error Coap::Stop(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     VerifyOrExit(mSocket.IsBound());
 
@@ -1699,14 +1697,14 @@ void Coap::HandleUdpReceive(void *aContext, otMessage *aMessage, const otMessage
                                            *static_cast<const Ip6::MessageInfo *>(aMessageInfo));
 }
 
-otError Coap::Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error Coap::Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     return static_cast<Coap &>(aCoapBase).Send(aMessage, aMessageInfo);
 }
 
-otError Coap::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error Coap::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    return mSocket.IsBound() ? mSocket.SendTo(aMessage, aMessageInfo) : OT_ERROR_INVALID_STATE;
+    return mSocket.IsBound() ? mSocket.SendTo(aMessage, aMessageInfo) : kErrorInvalidState;
 }
 
 } // namespace Coap

src/core/coap/coap.hpp

@@ -211,16 +211,16 @@ public:
         mNext         = nullptr;
     }
 
-    otError HandleBlockReceive(const uint8_t *aBlock,
+    Error HandleBlockReceive(const uint8_t *aBlock,
-                               uint32_t       aPosition,
+                             uint32_t       aPosition,
-                               uint16_t       aBlockLength,
+                             uint16_t       aBlockLength,
-                               bool           aMore,
+                             bool           aMore,
-                               uint32_t       aTotalLength) const
+                             uint32_t       aTotalLength) const
     {
         return mReceiveHook(otCoapBlockwiseResource::mContext, aBlock, aPosition, aBlockLength, aMore, aTotalLength);
     }
 
-    otError HandleBlockTransmit(uint8_t *aBlock, uint32_t aPosition, uint16_t *aBlockLength, bool *aMore) const
+    Error HandleBlockTransmit(uint8_t *aBlock, uint32_t aPosition, uint16_t *aBlockLength, bool *aMore) const
     {
         return mTransmitHook(otCoapBlockwiseResource::mContext, aBlock, aPosition, aBlockLength, aMore);
     }
@@ -314,12 +314,12 @@ public:
      * @param[in]  aMessageInfo  The message info containing source endpoint address and port.
      * @param[out] aResponse     A pointer to return a copy of a cached CoAP response matching given arguments.
      *
-     * @retval OT_ERROR_NONE       Matching response found and successfully created a copy.
+     * @retval kErrorNone      Matching response found and successfully created a copy.
-     * @retval OT_ERROR_NO_BUFS    Matching response found but there is not sufficient buffer to create a copy.
+     * @retval kErrorNoBufs    Matching response found but there is not sufficient buffer to create a copy.
-     * @retval OT_ERROR_NOT_FOUND  Matching response not found.
+     * @retval kErrorNotFound  Matching response not found.
      *
      */
-    otError GetMatchedResponseCopy(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Message **aResponse);
+    Error GetMatchedResponseCopy(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Message **aResponse);
 
     /**
      * This method gets a reference to the cached CoAP responses queue.
@@ -337,8 +337,8 @@ private:
 
     struct ResponseMetadata
     {
-        otError AppendTo(Message &aMessage) const { return aMessage.Append(*this); }
+        Error AppendTo(Message &aMessage) const { return aMessage.Append(*this); }
-        void    ReadFrom(const Message &aMessage);
+        void  ReadFrom(const Message &aMessage);
 
         TimeMilli        mDequeueTime;
         Ip6::MessageInfo mMessageInfo;
@@ -377,13 +377,12 @@ public:
      @ @param[in]   aMessageInfo    A reference to the message info associated with @p aMessage.
      * @param[in]   aContext        A pointer to arbitrary context information.
      *
-     * @retval  OT_ERROR_NONE       Server should continue processing this message, other
+     * @retval  kErrorNone      Server should continue processing this message, other return values indicates the
-     *                              return values indicates the server should stop processing
+     *                          server should stop processing this message.
-     *                              this message.
+     * @retval  kErrorNotTmf    The message is not a TMF message.
-     * @retval  OT_ERROR_NOT_TMF    The message is not a TMF message.
      *
      */
-    typedef otError (*Interceptor)(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo, void *aContext);
+    typedef Error (*Interceptor)(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo, void *aContext);
 
     /**
      * This method clears requests and responses used by this CoAP agent.
@@ -479,17 +478,17 @@ public:
      * @param[in]  aTransmitHook A pointer to a hook function for outgoing block-wise transfer.
      * @param[in]  aReceiveHook  A pointer to a hook function for incoming block-wise transfer.
      *
-     * @retval OT_ERROR_NONE     Successfully sent CoAP message.
+     * @retval kErrorNone     Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS  Failed to allocate retransmission data.
+     * @retval kErrorNoBufs   Failed to allocate retransmission data.
      *
      */
-    otError SendMessage(Message &                   aMessage,
+    Error SendMessage(Message &                   aMessage,
-                        const Ip6::MessageInfo &    aMessageInfo,
+                      const Ip6::MessageInfo &    aMessageInfo,
-                        const TxParameters &        aTxParameters,
+                      const TxParameters &        aTxParameters,
-                        otCoapResponseHandler       aHandler      = nullptr,
+                      otCoapResponseHandler       aHandler      = nullptr,
-                        void *                      aContext      = nullptr,
+                      void *                      aContext      = nullptr,
-                        otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
+                      otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
-                        otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
+                      otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
 #else  // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
     /**
@@ -505,15 +504,15 @@ public:
      * @param[in]  aHandler      A function pointer that shall be called on response reception or time-out.
      * @param[in]  aContext      A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE     Successfully sent CoAP message.
+     * @retval kErrorNone    Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient buffers available to send the CoAP message.
+     * @retval kErrorNoBufs  Insufficient buffers available to send the CoAP message.
      *
      */
-    otError SendMessage(Message &               aMessage,
+    Error SendMessage(Message &               aMessage,
-                        const Ip6::MessageInfo &aMessageInfo,
+                      const Ip6::MessageInfo &aMessageInfo,
-                        const TxParameters &    aTxParameters,
+                      const TxParameters &    aTxParameters,
-                        ResponseHandler         aHandler = nullptr,
+                      ResponseHandler         aHandler = nullptr,
-                        void *                  aContext = nullptr);
+                      void *                  aContext = nullptr);
 #endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
     /**
@@ -528,14 +527,14 @@ public:
      * @param[in]  aHandler      A function pointer that shall be called on response reception or time-out.
      * @param[in]  aContext      A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE     Successfully sent CoAP message.
+     * @retval kErrorNone    Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs  Insufficient buffers available to send the CoAP response.
      *
      */
-    otError SendMessage(Message &               aMessage,
+    Error SendMessage(Message &               aMessage,
-                        const Ip6::MessageInfo &aMessageInfo,
+                      const Ip6::MessageInfo &aMessageInfo,
-                        ResponseHandler         aHandler = nullptr,
+                      ResponseHandler         aHandler = nullptr,
-                        void *                  aContext = nullptr);
+                      void *                  aContext = nullptr);
 
     /**
      * This method sends a CoAP reset message.
@@ -543,12 +542,12 @@ public:
      * @param[in]  aRequest        A reference to the CoAP Message that was used in CoAP request.
      * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      *
-     * @retval OT_ERROR_NONE          Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS       Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
-     * @retval OT_ERROR_INVALID_ARGS  The @p aRequest is not of confirmable type.
+     * @retval kErrorInvalidArgs   The @p aRequest is not of confirmable type.
      *
      */
-    otError SendReset(Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
+    Error SendReset(Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
 
     /**
      * This method sends header-only CoAP response message.
@@ -557,12 +556,12 @@ public:
      * @param[in]  aRequest        A reference to the CoAP Message that was used in CoAP request.
      * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      *
-     * @retval OT_ERROR_NONE          Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS       Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
-     * @retval OT_ERROR_INVALID_ARGS  The @p aRequest header is not of confirmable type.
+     * @retval kErrorInvalidArgs   The @p aRequest header is not of confirmable type.
      *
      */
-    otError SendHeaderResponse(Message::Code aCode, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
+    Error SendHeaderResponse(Message::Code aCode, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
 
     /**
      * This method sends a CoAP ACK empty message which is used in Separate Response for confirmable requests.
@@ -570,12 +569,12 @@ public:
      * @param[in]  aRequest        A reference to the CoAP Message that was used in CoAP request.
      * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      *
-     * @retval OT_ERROR_NONE          Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS       Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
-     * @retval OT_ERROR_INVALID_ARGS  The @p aRequest header is not of confirmable type.
+     * @retval kErrorInvalidArgs   The @p aRequest header is not of confirmable type.
      *
      */
-    otError SendAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
+    Error SendAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
 
     /**
      * This method sends a CoAP ACK message on which a dummy CoAP response is piggybacked.
@@ -584,24 +583,24 @@ public:
      * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      * @param[in]  aCode           The CoAP code of the dummy CoAP response.
      *
-     * @retval OT_ERROR_NONE          Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS       Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
-     * @retval OT_ERROR_INVALID_ARGS  The @p aRequest header is not of confirmable type.
+     * @retval kErrorInvalidArgs   The @p aRequest header is not of confirmable type.
      *
      */
-    otError SendEmptyAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Code aCode = kCodeChanged);
+    Error SendEmptyAck(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo, Code aCode = kCodeChanged);
 
     /**
      * This method sends a header-only CoAP message to indicate no resource matched for the request.
      *
      * @param[in]  aRequest        A reference to the CoAP Message that was used in CoAP request.
-     * @param[in]  aMessageInfo          The message info corresponding to the CoAP request.
+     * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      *
-     * @retval OT_ERROR_NONE         Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS      Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
      *
      */
-    otError SendNotFound(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
+    Error SendNotFound(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     /**
@@ -609,13 +608,13 @@ public:
      * were sent out of order.
      *
      * @param[in]  aRequest        A reference to the CoAP Message that was used in CoAP request.
-     * @param[in]  aMessageInfo          The message info corresponding to the CoAP request.
+     * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
      *
-     * @retval OT_ERROR_NONE         Successfully enqueued the CoAP response message.
+     * @retval kErrorNone          Successfully enqueued the CoAP response message.
-     * @retval OT_ERROR_NO_BUFS      Insufficient buffers available to send the CoAP response.
+     * @retval kErrorNoBufs        Insufficient buffers available to send the CoAP response.
      *
      */
-    otError SendRequestEntityIncomplete(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
+    Error SendRequestEntityIncomplete(const Message &aRequest, const Ip6::MessageInfo &aMessageInfo)
     {
         return SendHeaderResponse(kCodeRequestIncomplete, aRequest, aMessageInfo);
     }
@@ -624,16 +623,16 @@ public:
     /**
      * This method aborts CoAP transactions associated with given handler and context.
      *
-     * The associated response handler will be called with OT_ERROR_ABORT.
+     * The associated response handler will be called with kErrorAbort.
      *
      * @param[in]  aHandler  A function pointer that should be called when the transaction ends.
      * @param[in]  aContext  A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE       Successfully aborted CoAP transactions.
+     * @retval kErrorNone      Successfully aborted CoAP transactions.
-     * @retval OT_ERROR_NOT_FOUND  CoAP transaction associated with given handler was not found.
+     * @retval kErrorNotFound  CoAP transaction associated with given handler was not found.
      *
      */
-    otError AbortTransaction(ResponseHandler aHandler, void *aContext);
+    Error AbortTransaction(ResponseHandler aHandler, void *aContext);
 
     /**
      * This method sets interceptor to be called before processing a CoAP packet.
@@ -668,11 +667,11 @@ protected:
      * @param[in]  aMessage      A reference to the message to send.
      * @param[in]  aMessageInfo  A reference to the message info associated with @p aMessage.
      *
-     * @retval OT_ERROR_NONE     Successfully sent CoAP message.
+     * @retval kErrorNone    Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS  Failed to allocate retransmission data.
+     * @retval kErrorNoBufs  Failed to allocate retransmission data.
      *
      */
-    typedef otError (*Sender)(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    typedef Error (*Sender)(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
     /**
      * This constructor initializes the object.
@@ -696,9 +695,9 @@ protected:
 private:
     struct Metadata
     {
-        otError AppendTo(Message &aMessage) const { return aMessage.Append(*this); }
+        Error AppendTo(Message &aMessage) const { return aMessage.Append(*this); }
-        void    ReadFrom(const Message &aMessage);
+        void  ReadFrom(const Message &aMessage);
-        void    UpdateIn(Message &aMessage) const;
+        void  UpdateIn(Message &aMessage) const;
 
         Ip6::Address    mSourceAddress;            // IPv6 address of the message source.
         Ip6::Address    mDestinationAddress;       // IPv6 address of the message destination.
@@ -739,44 +738,44 @@ private:
                                      const Metadata &        aMetadata,
                                      Message *               aResponse,
                                      const Ip6::MessageInfo *aMessageInfo,
-                                     otError                 aResult);
+                                     Error                   aResult);
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-    void    FreeLastBlockResponse(void);
+    void  FreeLastBlockResponse(void);
-    otError CacheLastBlockResponse(Message *aResponse);
+    Error CacheLastBlockResponse(Message *aResponse);
 
-    otError PrepareNextBlockRequest(Message::BlockType aType,
+    Error PrepareNextBlockRequest(Message::BlockType aType,
-                                    bool               aMoreBlocks,
+                                  bool               aMoreBlocks,
-                                    Message &          aRequestOld,
+                                  Message &          aRequestOld,
-                                    Message &          aRequest,
+                                  Message &          aRequest,
-                                    Message &          aMessage);
+                                  Message &          aMessage);
-    otError ProcessBlock1Request(Message &                aMessage,
+    Error ProcessBlock1Request(Message &                aMessage,
-                                 const Ip6::MessageInfo & aMessageInfo,
+                               const Ip6::MessageInfo & aMessageInfo,
-                                 const ResourceBlockWise &aResource,
+                               const ResourceBlockWise &aResource,
-                                 uint32_t                 aTotalLength);
+                               uint32_t                 aTotalLength);
-    otError ProcessBlock2Request(Message &                aMessage,
+    Error ProcessBlock2Request(Message &                aMessage,
-                                 const Ip6::MessageInfo & aMessageInfo,
+                               const Ip6::MessageInfo & aMessageInfo,
-                                 const ResourceBlockWise &aResource);
+                               const ResourceBlockWise &aResource);
 #endif
     void ProcessReceivedRequest(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
     void ProcessReceivedResponse(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-    otError SendNextBlock1Request(Message &               aRequest,
+    Error SendNextBlock1Request(Message &               aRequest,
-                                  Message &               aMessage,
+                                Message &               aMessage,
-                                  const Ip6::MessageInfo &aMessageInfo,
+                                const Ip6::MessageInfo &aMessageInfo,
-                                  const Metadata &        aCoapMetadata);
+                                const Metadata &        aCoapMetadata);
-    otError SendNextBlock2Request(Message &               aRequest,
+    Error SendNextBlock2Request(Message &               aRequest,
-                                  Message &               aMessage,
+                                Message &               aMessage,
-                                  const Ip6::MessageInfo &aMessageInfo,
+                                const Ip6::MessageInfo &aMessageInfo,
-                                  const Metadata &        aCoapMetadata,
+                                const Metadata &        aCoapMetadata,
-                                  uint32_t                aTotalLength,
+                                uint32_t                aTotalLength,
-                                  bool                    aBeginBlock1Transfer);
+                                bool                    aBeginBlock1Transfer);
 #endif
-    void    SendCopy(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    void  SendCopy(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    otError SendEmptyMessage(Type aType, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
+    Error SendEmptyMessage(Type aType, const Message &aRequest, const Ip6::MessageInfo &aMessageInfo);
 
-    otError Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    Error Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
     MessageQueue      mPendingRequests;
     uint16_t          mMessageId;
@@ -820,28 +819,28 @@ public:
      * @param[in]  aPort             The local UDP port to bind to.
      * @param[in]  aNetifIdentifier  The network interface identifier to bind.
      *
-     * @retval OT_ERROR_NONE    Successfully started the CoAP service.
+     * @retval kErrorNone    Successfully started the CoAP service.
-     * @retval OT_ERROR_FAILED  Failed to start CoAP agent.
+     * @retval kErrorFailed  Failed to start CoAP agent.
      *
      */
-    otError Start(uint16_t aPort, otNetifIdentifier aNetifIdentifier = OT_NETIF_UNSPECIFIED);
+    Error Start(uint16_t aPort, otNetifIdentifier aNetifIdentifier = OT_NETIF_UNSPECIFIED);
 
     /**
      * This method stops the CoAP service.
      *
-     * @retval OT_ERROR_NONE    Successfully stopped the CoAP service.
+     * @retval kErrorNone    Successfully stopped the CoAP service.
-     * @retval OT_ERROR_FAILED  Failed to stop CoAP agent.
+     * @retval kErrorFailed  Failed to stop CoAP agent.
      *
      */
-    otError Stop(void);
+    Error Stop(void);
 
 protected:
     Ip6::Udp::Socket mSocket;
 
 private:
-    static otError Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    static Error Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    static void    HandleUdpReceive(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo);
+    static void  HandleUdpReceive(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo);
-    otError        Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    Error        Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 };
 
 } // namespace Coap

src/core/coap/coap_message.cpp

@@ -65,9 +65,9 @@ void Message::Init(Type aType, Code aCode)
     SetCode(aCode);
 }
 
-otError Message::Init(Type aType, Code aCode, const char *aUriPath)
+Error Message::Init(Type aType, Code aCode, const char *aUriPath)
 {
-    otError error;
+    Error error;
 
     Init(aType, aCode);
     SuccessOrExit(error = GenerateRandomToken(kDefaultTokenLength));
@@ -87,17 +87,17 @@ void Message::InitAsNonConfirmablePost(void)
     Init(kTypeNonConfirmable, kCodePost);
 }
 
-otError Message::InitAsConfirmablePost(const char *aUriPath)
+Error Message::InitAsConfirmablePost(const char *aUriPath)
 {
     return Init(kTypeConfirmable, kCodePost, aUriPath);
 }
 
-otError Message::InitAsNonConfirmablePost(const char *aUriPath)
+Error Message::InitAsNonConfirmablePost(const char *aUriPath)
 {
     return Init(kTypeNonConfirmable, kCodePost, aUriPath);
 }
 
-otError Message::InitAsPost(const Ip6::Address &aDestination, const char *aUriPath)
+Error Message::InitAsPost(const Ip6::Address &aDestination, const char *aUriPath)
 {
     return Init(aDestination.IsMulticast() ? kTypeNonConfirmable : kTypeConfirmable, kCodePost, aUriPath);
 }
@@ -160,15 +160,15 @@ uint8_t Message::WriteExtendedOptionField(uint16_t aValue, uint8_t *&aBuffer)
     return rval;
 }
 
-otError Message::AppendOption(uint16_t aNumber, uint16_t aLength, const void *aValue)
+Error Message::AppendOption(uint16_t aNumber, uint16_t aLength, const void *aValue)
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     uint16_t delta;
     uint8_t  header[kMaxOptionHeaderSize];
     uint16_t headerLength;
     uint8_t *cur;
 
-    VerifyOrExit(aNumber >= GetHelpData().mOptionLast, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aNumber >= GetHelpData().mOptionLast, error = kErrorInvalidArgs);
     delta = aNumber - GetHelpData().mOptionLast;
 
     cur = &header[1];
@@ -178,8 +178,7 @@ otError Message::AppendOption(uint16_t aNumber, uint16_t aLength, const void *aV
 
     headerLength = static_cast<uint16_t>(cur - header);
 
-    VerifyOrExit(static_cast<uint32_t>(GetLength()) + headerLength + aLength < kMaxHeaderLength,
+    VerifyOrExit(static_cast<uint32_t>(GetLength()) + headerLength + aLength < kMaxHeaderLength, error = kErrorNoBufs);
-                 error = OT_ERROR_NO_BUFS);
 
     SuccessOrExit(error = AppendBytes(header, headerLength));
     SuccessOrExit(error = AppendBytes(aValue, aLength));
@@ -192,7 +191,7 @@ exit:
     return error;
 }
 
-otError Message::AppendUintOption(uint16_t aNumber, uint32_t aValue)
+Error Message::AppendUintOption(uint16_t aNumber, uint32_t aValue)
 {
     uint8_t        buffer[sizeof(uint32_t)];
     const uint8_t *value  = &buffer[0];
@@ -209,14 +208,14 @@ otError Message::AppendUintOption(uint16_t aNumber, uint32_t aValue)
     return AppendOption(aNumber, length, value);
 }
 
-otError Message::AppendStringOption(uint16_t aNumber, const char *aValue)
+Error Message::AppendStringOption(uint16_t aNumber, const char *aValue)
 {
     return AppendOption(aNumber, static_cast<uint16_t>(strlen(aValue)), aValue);
 }
 
-otError Message::AppendUriPathOptions(const char *aUriPath)
+Error Message::AppendUriPathOptions(const char *aUriPath)
 {
-    otError     error = OT_ERROR_NONE;
+    Error       error = kErrorNone;
     const char *cur   = aUriPath;
     const char *end;
 
@@ -232,10 +231,10 @@ exit:
     return error;
 }
 
-otError Message::ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) const
+Error Message::ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) const
 {
     char *           curUriPath = aUriPath;
-    otError          error      = OT_ERROR_NONE;
+    Error            error      = kErrorNone;
     Option::Iterator iterator;
 
     SuccessOrExit(error = iterator.Init(*this, kOptionUriPath));
@@ -249,7 +248,7 @@ otError Message::ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) c
             *curUriPath++ = '/';
         }
 
-        VerifyOrExit(curUriPath + optionLength < OT_ARRAY_END(aUriPath), error = OT_ERROR_PARSE);
+        VerifyOrExit(curUriPath + optionLength < OT_ARRAY_END(aUriPath), error = kErrorParse);
 
         IgnoreError(iterator.ReadOptionValue(curUriPath));
         curUriPath += optionLength;
@@ -263,14 +262,14 @@ exit:
     return error;
 }
 
-otError Message::AppendBlockOption(Message::BlockType aType, uint32_t aNum, bool aMore, otCoapBlockSzx aSize)
+Error Message::AppendBlockOption(Message::BlockType aType, uint32_t aNum, bool aMore, otCoapBlockSzx aSize)
 {
-    otError  error   = OT_ERROR_NONE;
+    Error    error   = kErrorNone;
     uint32_t encoded = aSize;
 
-    VerifyOrExit(aType == kBlockType1 || aType == kBlockType2, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aType == kBlockType1 || aType == kBlockType2, error = kErrorInvalidArgs);
-    VerifyOrExit(aSize <= OT_COAP_OPTION_BLOCK_SZX_1024, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aSize <= OT_COAP_OPTION_BLOCK_SZX_1024, error = kErrorInvalidArgs);
-    VerifyOrExit(aNum < kBlockNumMax, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aNum < kBlockNumMax, error = kErrorInvalidArgs);
 
     encoded |= static_cast<uint32_t>(aMore << kBlockMOffset);
     encoded |= aNum << kBlockNumOffset;
@@ -282,13 +281,13 @@ exit:
 }
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-otError Message::ReadBlockOptionValues(uint16_t aBlockType)
+Error Message::ReadBlockOptionValues(uint16_t aBlockType)
 {
-    otError          error                     = OT_ERROR_NONE;
+    Error            error                     = kErrorNone;
     uint8_t          buf[kMaxOptionHeaderSize] = {0};
     Option::Iterator iterator;
 
-    VerifyOrExit((aBlockType == kOptionBlock1) || (aBlockType == kOptionBlock2), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit((aBlockType == kOptionBlock1) || (aBlockType == kOptionBlock2), error = kErrorInvalidArgs);
 
     SuccessOrExit(error = iterator.Init(*this, aBlockType));
     SuccessOrExit(error = iterator.ReadOptionValue(buf));
@@ -315,7 +314,7 @@ otError Message::ReadBlockOptionValues(uint16_t aBlockType)
         SetBlockWiseBlockSize(static_cast<otCoapBlockSzx>(buf[2] & 0x07));
         break;
     default:
-        error = OT_ERROR_INVALID_ARGS;
+        error = kErrorInvalidArgs;
         break;
     }
 
@@ -324,12 +323,12 @@ exit:
 }
 #endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
-otError Message::SetPayloadMarker(void)
+Error Message::SetPayloadMarker(void)
 {
-    otError error  = OT_ERROR_NONE;
+    Error   error  = kErrorNone;
     uint8_t marker = kPayloadMarker;
 
-    VerifyOrExit(GetLength() < kMaxHeaderLength, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(GetLength() < kMaxHeaderLength, error = kErrorNoBufs);
     SuccessOrExit(error = Append(marker));
     GetHelpData().mHeaderLength = GetLength();
 
@@ -340,9 +339,9 @@ exit:
     return error;
 }
 
-otError Message::ParseHeader(void)
+Error Message::ParseHeader(void)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Option::Iterator iterator;
 
     OT_ASSERT(mBuffer.mHead.mMetadata.mReserved >=
@@ -354,7 +353,7 @@ otError Message::ParseHeader(void)
     GetHelpData().mHeaderOffset = GetOffset();
     IgnoreError(Read(GetHelpData().mHeaderOffset, GetHelpData().mHeader));
 
-    VerifyOrExit(GetTokenLength() <= kMaxTokenLength, error = OT_ERROR_PARSE);
+    VerifyOrExit(GetTokenLength() <= kMaxTokenLength, error = kErrorParse);
 
     SuccessOrExit(error = iterator.Init(*this));
 
@@ -370,7 +369,7 @@ exit:
     return error;
 }
 
-otError Message::SetToken(const uint8_t *aToken, uint8_t aTokenLength)
+Error Message::SetToken(const uint8_t *aToken, uint8_t aTokenLength)
 {
     OT_ASSERT(aTokenLength <= kMaxTokenLength);
 
@@ -381,7 +380,7 @@ otError Message::SetToken(const uint8_t *aToken, uint8_t aTokenLength)
     return SetLength(GetHelpData().mHeaderLength);
 }
 
-otError Message::GenerateRandomToken(uint8_t aTokenLength)
+Error Message::GenerateRandomToken(uint8_t aTokenLength)
 {
     uint8_t token[kMaxTokenLength];
 
@@ -392,7 +391,7 @@ otError Message::GenerateRandomToken(uint8_t aTokenLength)
     return SetToken(token, aTokenLength);
 }
 
-otError Message::SetTokenFromMessage(const Message &aMessage)
+Error Message::SetTokenFromMessage(const Message &aMessage)
 {
     return SetToken(aMessage.GetToken(), aMessage.GetTokenLength());
 }
@@ -404,7 +403,7 @@ bool Message::IsTokenEqual(const Message &aMessage) const
     return ((tokenLength == aMessage.GetTokenLength()) && (memcmp(GetToken(), aMessage.GetToken(), tokenLength) == 0));
 }
 
-otError Message::SetDefaultResponseHeader(const Message &aRequest)
+Error Message::SetDefaultResponseHeader(const Message &aRequest)
 {
     Init(kTypeAck, kCodeChanged);
 
@@ -525,9 +524,9 @@ const char *Message::CodeToString(void) const
 }
 #endif // OPENTHREAD_CONFIG_COAP_API_ENABLE
 
-otError Option::Iterator::Init(const Message &aMessage)
+Error Option::Iterator::Init(const Message &aMessage)
 {
-    otError  error  = OT_ERROR_PARSE;
+    Error    error  = kErrorParse;
     uint32_t offset = static_cast<uint32_t>(aMessage.GetHelpData().mHeaderOffset) + aMessage.GetOptionStart();
 
     // Note that the case where `offset == aMessage.GetLength())` is
@@ -547,9 +546,9 @@ exit:
     return error;
 }
 
-otError Option::Iterator::Advance(void)
+Error Option::Iterator::Advance(void)
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     uint8_t  headerByte;
     uint16_t optionDelta;
     uint16_t optionLength;
@@ -558,22 +557,22 @@ otError Option::Iterator::Advance(void)
 
     error = Read(sizeof(uint8_t), &headerByte);
 
-    if ((error != OT_ERROR_NONE) || (headerByte == Message::kPayloadMarker))
+    if ((error != kErrorNone) || (headerByte == Message::kPayloadMarker))
     {
         // Payload Marker indicates end of options and start of payload.
         // Absence of a Payload Marker indicates a zero-length payload.
 
         MarkAsDone();
 
-        if (error == OT_ERROR_NONE)
+        if (error == kErrorNone)
         {
             // The presence of a marker followed by a zero-length payload
             // MUST be processed as a message format error.
 
-            VerifyOrExit(mNextOptionOffset < GetMessage().GetLength(), error = OT_ERROR_PARSE);
+            VerifyOrExit(mNextOptionOffset < GetMessage().GetLength(), error = kErrorParse);
         }
 
-        ExitNow(error = OT_ERROR_NONE);
+        ExitNow(error = kErrorNone);
     }
 
     optionDelta = (headerByte & Message::kOptionDeltaMask) >> Message::kOptionDeltaOffset;
@@ -582,14 +581,14 @@ otError Option::Iterator::Advance(void)
     optionLength = (headerByte & Message::kOptionLengthMask) >> Message::kOptionLengthOffset;
     SuccessOrExit(error = ReadExtendedOptionField(optionLength));
 
-    VerifyOrExit(optionLength <= GetMessage().GetLength() - mNextOptionOffset, error = OT_ERROR_PARSE);
+    VerifyOrExit(optionLength <= GetMessage().GetLength() - mNextOptionOffset, error = kErrorParse);
     mNextOptionOffset += optionLength;
 
     mOption.mNumber += optionDelta;
     mOption.mLength = optionLength;
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         MarkAsParseErrored();
     }
@@ -597,25 +596,25 @@ exit:
     return error;
 }
 
-otError Option::Iterator::ReadOptionValue(void *aValue) const
+Error Option::Iterator::ReadOptionValue(void *aValue) const
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(!IsDone(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(!IsDone(), error = kErrorNotFound);
     GetMessage().ReadBytes(mNextOptionOffset - mOption.mLength, aValue, mOption.mLength);
 
 exit:
     return error;
 }
 
-otError Option::Iterator::ReadOptionValue(uint64_t &aUintValue) const
+Error Option::Iterator::ReadOptionValue(uint64_t &aUintValue) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t buffer[sizeof(uint64_t)];
 
-    VerifyOrExit(!IsDone(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(!IsDone(), error = kErrorNotFound);
 
-    VerifyOrExit(mOption.mLength <= sizeof(uint64_t), error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(mOption.mLength <= sizeof(uint64_t), error = kErrorNoBufs);
     IgnoreError(ReadOptionValue(buffer));
 
     aUintValue = 0;
@@ -630,13 +629,13 @@ exit:
     return error;
 }
 
-otError Option::Iterator::Read(uint16_t aLength, void *aBuffer)
+Error Option::Iterator::Read(uint16_t aLength, void *aBuffer)
 {
     // Reads `aLength` bytes from the message into `aBuffer` at
     // `mNextOptionOffset` and updates the `mNextOptionOffset` on a
     // successful read (i.e., when entire `aLength` bytes can be read).
 
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     SuccessOrExit(error = GetMessage().Read(mNextOptionOffset, aBuffer, aLength));
     mNextOptionOffset += aLength;
@@ -645,9 +644,9 @@ exit:
     return error;
 }
 
-otError Option::Iterator::ReadExtendedOptionField(uint16_t &aValue)
+Error Option::Iterator::ReadExtendedOptionField(uint16_t &aValue)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     VerifyOrExit(aValue >= Message::kOption1ByteExtension);
 
@@ -668,18 +667,18 @@ otError Option::Iterator::ReadExtendedOptionField(uint16_t &aValue)
     }
     else
     {
-        error = OT_ERROR_PARSE;
+        error = kErrorParse;
     }
 
 exit:
     return error;
 }
 
-otError Option::Iterator::InitOrAdvance(const Message *aMessage, uint16_t aNumber)
+Error Option::Iterator::InitOrAdvance(const Message *aMessage, uint16_t aNumber)
 {
-    otError error = (aMessage != nullptr) ? Init(*aMessage) : Advance();
+    Error error = (aMessage != nullptr) ? Init(*aMessage) : Advance();
 
-    while ((error == OT_ERROR_NONE) && !IsDone() && (GetOption()->GetNumber() != aNumber))
+    while ((error == kErrorNone) && !IsDone() && (GetOption()->GetNumber() != aNumber))
     {
         error = Advance();
     }

src/core/coap/coap_message.hpp

@@ -223,33 +223,33 @@ public:
      * @param[in]  aCode              The Code value.
      * @param[in]  aUriPath           A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError Init(Type aType, Code aCode, const char *aUriPath);
+    Error Init(Type aType, Code aCode, const char *aUriPath);
 
     /**
      * This method initializes the CoAP header as `kTypeConfirmable` and `kCodePost` with a given URI Path.
      *
      * @param[in]  aUriPath           A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError InitAsConfirmablePost(const char *aUriPath);
+    Error InitAsConfirmablePost(const char *aUriPath);
 
     /**
      * This method initializes the CoAP header as `kTypeNonConfirmable` and `kCodePost` with a given URI Path.
      *
      * @param[in]  aUriPath           A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError InitAsNonConfirmablePost(const char *aUriPath);
+    Error InitAsNonConfirmablePost(const char *aUriPath);
 
     /**
      * This method initializes the CoAP header as `kCodePost` with a given URI Path with its type determined from a
@@ -259,11 +259,11 @@ public:
      *                                `kTypeNonConfirmable` if multicast address, `kTypeConfirmable` otherwise.
      * @param[in]  aUriPath           A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError InitAsPost(const Ip6::Address &aDestination, const char *aUriPath);
+    Error InitAsPost(const Ip6::Address &aDestination, const char *aUriPath);
 
     /**
      * This method writes header to the message. This must be called before sending the message.
@@ -381,33 +381,33 @@ public:
      * @param[in]  aToken        A pointer to the Token value.
      * @param[in]  aTokenLength  The Length of @p aToken.
      *
-     * @retval OT_ERROR_NONE     Successfully set the token value.
+     * @retval kErrorNone    Successfully set the token value.
-     * @retval OT_ERROR_NO_BUFS  Insufficient message buffers available to set the token value.
+     * @retval kErrorNoBufs  Insufficient message buffers available to set the token value.
      *
      */
-    otError SetToken(const uint8_t *aToken, uint8_t aTokenLength);
+    Error SetToken(const uint8_t *aToken, uint8_t aTokenLength);
 
     /**
      * This method sets the Token value and length by copying it from another given message.
      *
      * @param[in] aMessage       The message to copy the Token from.
      *
-     * @retval OT_ERROR_NONE     Successfully set the token value.
+     * @retval kErrorNone    Successfully set the token value.
-     * @retval OT_ERROR_NO_BUFS  Insufficient message buffers available to set the token value.
+     * @retval kErrorNoBufs  Insufficient message buffers available to set the token value.
      *
      */
-    otError SetTokenFromMessage(const Message &aMessage);
+    Error SetTokenFromMessage(const Message &aMessage);
 
     /**
      * This method sets the Token length and randomizes its value.
      *
      * @param[in]  aTokenLength  The Length of a Token to set.
      *
-     * @retval OT_ERROR_NONE     Successfully set the token value.
+     * @retval kErrorNone    Successfully set the token value.
-     * @retval OT_ERROR_NO_BUFS  Insufficient message buffers available to set the token value.
+     * @retval kErrorNoBufs  Insufficient message buffers available to set the token value.
      *
      */
-    otError GenerateRandomToken(uint8_t aTokenLength);
+    Error GenerateRandomToken(uint8_t aTokenLength);
 
     /**
      * This method checks if Tokens in two CoAP headers are equal.
@@ -427,12 +427,12 @@ public:
      * @param[in] aLength   The CoAP Option length.
      * @param[in] aValue    A pointer to the CoAP Option value (@p aLength bytes are used as Option value).
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendOption(uint16_t aNumber, uint16_t aLength, const void *aValue);
+    Error AppendOption(uint16_t aNumber, uint16_t aLength, const void *aValue);
 
     /**
      * This method appends an unsigned integer CoAP option as specified in RFC-7252 section-3.2
@@ -440,12 +440,12 @@ public:
      * @param[in]  aNumber  The CoAP Option number.
      * @param[in]  aValue   The CoAP Option unsigned integer value.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendUintOption(uint16_t aNumber, uint32_t aValue);
+    Error AppendUintOption(uint16_t aNumber, uint32_t aValue);
 
     /**
      * This method appends a string CoAP option.
@@ -453,35 +453,35 @@ public:
      * @param[in]  aNumber  The CoAP Option number.
      * @param[in]  aValue   The CoAP Option string value.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendStringOption(uint16_t aNumber, const char *aValue);
+    Error AppendStringOption(uint16_t aNumber, const char *aValue);
 
     /**
      * This method appends an Observe option.
      *
      * @param[in]  aObserve  Observe field value.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      */
-    otError AppendObserveOption(uint32_t aObserve) { return AppendUintOption(kOptionObserve, aObserve & kObserveMask); }
+    Error AppendObserveOption(uint32_t aObserve) { return AppendUintOption(kOptionObserve, aObserve & kObserveMask); }
 
     /**
      * This method appends a Uri-Path option.
      *
      * @param[in]  aUriPath           A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendUriPathOptions(const char *aUriPath);
+    Error AppendUriPathOptions(const char *aUriPath);
 
     /**
      * This method reads the Uri-Path options and constructs the URI path in the buffer referenced by @p `aUriPath`.
@@ -489,11 +489,11 @@ public:
      * @param[in] aUriPath  A reference to the buffer for storing URI path.
      *                      NOTE: The buffer size must be `kMaxReceivedUriPath + 1`.
      *
-     * @retval  OT_ERROR_NONE   Successfully read the Uri-Path options.
+     * @retval  kErrorNone   Successfully read the Uri-Path options.
-     * @retval  OT_ERROR_PARSE  CoAP Option header not well-formed.
+     * @retval  kErrorParse  CoAP Option header not well-formed.
      *
      */
-    otError ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) const;
+    Error ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) const;
 
     /**
      * This method appends a Block option
@@ -503,36 +503,36 @@ public:
      * @param[in]  aMore              Boolean to indicate more blocks are to be sent.
      * @param[in]  aSize              Maximum block size.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendBlockOption(BlockType aType, uint32_t aNum, bool aMore, otCoapBlockSzx aSize);
+    Error AppendBlockOption(BlockType aType, uint32_t aNum, bool aMore, otCoapBlockSzx aSize);
 
     /**
      * This method appends a Proxy-Uri option.
      *
      * @param[in]  aProxyUri          A pointer to a null-terminated string.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendProxyUriOption(const char *aProxyUri) { return AppendStringOption(kOptionProxyUri, aProxyUri); }
+    Error AppendProxyUriOption(const char *aProxyUri) { return AppendStringOption(kOptionProxyUri, aProxyUri); }
 
     /**
      * This method appends a Content-Format option.
      *
      * @param[in]  aContentFormat  The Content Format value.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      *
      */
-    otError AppendContentFormatOption(otCoapOptionContentFormat aContentFormat)
+    Error AppendContentFormatOption(otCoapOptionContentFormat aContentFormat)
     {
         return AppendUintOption(kOptionContentFormat, static_cast<uint32_t>(aContentFormat));
     }
@@ -542,22 +542,22 @@ public:
      *
      * @param[in]  aMaxAge  The Max-Age value.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      */
-    otError AppendMaxAgeOption(uint32_t aMaxAge) { return AppendUintOption(kOptionMaxAge, aMaxAge); }
+    Error AppendMaxAgeOption(uint32_t aMaxAge) { return AppendUintOption(kOptionMaxAge, aMaxAge); }
 
     /**
      * This method appends a single Uri-Query option.
      *
      * @param[in]  aUriQuery  A pointer to null-terminated string, which should contain a single key=value pair.
      *
-     * @retval OT_ERROR_NONE          Successfully appended the option.
+     * @retval kErrorNone         Successfully appended the option.
-     * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
-     * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
      */
-    otError AppendUriQueryOption(const char *aUriQuery) { return AppendStringOption(kOptionUriQuery, aUriQuery); }
+    Error AppendUriQueryOption(const char *aUriQuery) { return AppendStringOption(kOptionUriQuery, aUriQuery); }
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     /**
@@ -566,11 +566,11 @@ public:
      *
      * @param[in]   aBlockType  Block1 or Block2 option value.
      *
-     * @retval  OT_ERROR_NONE           The option has been found and is valid.
+     * @retval  kErrorNone          The option has been found and is valid.
-     * @retval  OT_ERROR_NOT_FOUND      The option has not been found.
+     * @retval  kErrorNotFound      The option has not been found.
-     * @retval  OT_ERROR_INVALID_ARGS   The option is invalid.
+     * @retval  kErrorInvalidArgs   The option is invalid.
      */
-    otError ReadBlockOptionValues(uint16_t aBlockType);
+    Error ReadBlockOptionValues(uint16_t aBlockType);
 
     /**
      * This method returns the current header length of a message.
@@ -609,22 +609,22 @@ public:
     /**
      * This function reads and reassembles the URI path string and fills it into @p aUriPath.
      *
-     * @retval  OT_ERROR_NONE       URI path string has been reassembled.
+     * @retval  kErrorNone      URI path string has been reassembled.
-     * @retval  OT_ERROR_NO_BUFS    URI path string is too long.
+     * @retval  kErrorNoBufs    URI path string is too long.
      *
      */
-    otError GetUriPath(char *aUriPath) const;
+    Error GetUriPath(char *aUriPath) const;
 
     /**
      * This method adds Payload Marker indicating beginning of the payload to the CoAP header.
      *
      * It also set offset to the start of payload.
      *
-     * @retval OT_ERROR_NONE     Payload Marker successfully added.
+     * @retval kErrorNone    Payload Marker successfully added.
-     * @retval OT_ERROR_NO_BUFS  Message Payload Marker exceeds the buffer size.
+     * @retval kErrorNoBufs  Message Payload Marker exceeds the buffer size.
      *
      */
-    otError SetPayloadMarker(void);
+    Error SetPayloadMarker(void);
 
     /**
      * This method returns the offset of the first CoAP option.
@@ -637,22 +637,22 @@ public:
     /**
      * This method parses CoAP header and moves offset end of CoAP header.
      *
-     * @retval  OT_ERROR_NONE   Successfully parsed CoAP header from the message.
+     * @retval  kErrorNone   Successfully parsed CoAP header from the message.
-     * @retval  OT_ERROR_PARSE  Failed to parse the CoAP header.
+     * @retval  kErrorParse  Failed to parse the CoAP header.
      *
      */
-    otError ParseHeader(void);
+    Error ParseHeader(void);
 
     /**
      * This method sets a default response header based on request header.
      *
      * @param[in]  aRequest  The request message.
      *
-     * @retval OT_ERROR_NONE     Successfully set the default response header.
+     * @retval kErrorNone    Successfully set the default response header.
-     * @retval OT_ERROR_NO_BUFS  Insufficient message buffers available to set the default response header.
+     * @retval kErrorNoBufs  Insufficient message buffers available to set the default response header.
      *
      */
-    otError SetDefaultResponseHeader(const Message &aRequest);
+    Error SetDefaultResponseHeader(const Message &aRequest);
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
@@ -1058,11 +1058,11 @@ public:
          *
          * @param[in] aMessage  The CoAP message.
          *
-         * @retval OT_ERROR_NONE   Successfully initialized. Iterator is either at the first option or done.
+         * @retval kErrorNone   Successfully initialized. Iterator is either at the first option or done.
-         * @retval OT_ERROR_PARSE  CoAP Option header in @p aMessage is not well-formed.
+         * @retval kErrorParse  CoAP Option header in @p aMessage is not well-formed.
          *
          */
-        otError Init(const Message &aMessage);
+        Error Init(const Message &aMessage);
 
         /**
          * This method initializes the iterator to iterate over CoAP Options in a CoAP message matching a given Option
@@ -1077,11 +1077,11 @@ public:
          * @param[in] aMessage  The CoAP message.
          * @param[in] aNumber   The CoAP Option Number.
          *
-         * @retval  OT_ERROR_NONE   Successfully initialized. Iterator is either at the first matching option or done.
+         * @retval  kErrorNone   Successfully initialized. Iterator is either at the first matching option or done.
-         * @retval  OT_ERROR_PARSE  CoAP Option header in @p aMessage is not well-formed.
+         * @retval  kErrorParse  CoAP Option header in @p aMessage is not well-formed.
          *
          */
-        otError Init(const Message &aMessage, uint16_t aNumber) { return InitOrAdvance(&aMessage, aNumber); }
+        Error Init(const Message &aMessage, uint16_t aNumber) { return InitOrAdvance(&aMessage, aNumber); }
 
         /**
          * This method indicates whether or not the iterator is done (i.e., has reached the end of CoAP Option Header).
@@ -1108,11 +1108,11 @@ public:
          *
          * The iterator is updated to point to the next option or marked as done when there are no more options.
          *
-         * @retval  OT_ERROR_NONE   Successfully advanced the iterator.
+         * @retval  kErrorNone   Successfully advanced the iterator.
-         * @retval  OT_ERROR_PARSE  CoAP Option header is not well-formed.
+         * @retval  kErrorParse  CoAP Option header is not well-formed.
          *
          */
-        otError Advance(void);
+        Error Advance(void);
 
         /**
          * This method advances the iterator to the next CoAP Option in the header matching a given Option Number value.
@@ -1122,11 +1122,11 @@ public:
          *
          * @param[in] aNumber   The CoAP Option Number.
          *
-         * @retval  OT_ERROR_NONE   Successfully advanced the iterator.
+         * @retval  kErrorNone   Successfully advanced the iterator.
-         * @retval  OT_ERROR_PARSE  CoAP Option header is not well-formed.
+         * @retval  kErrorParse  CoAP Option header is not well-formed.
          *
          */
-        otError Advance(uint16_t aNumber) { return InitOrAdvance(nullptr, aNumber); }
+        Error Advance(uint16_t aNumber) { return InitOrAdvance(nullptr, aNumber); }
 
         /**
          * This method gets the CoAP message associated with the iterator.
@@ -1151,23 +1151,23 @@ public:
          * @param[out]  aValue   The pointer to a buffer to copy the Option Value. The buffer is assumed to be
          *                       sufficiently large (i.e. at least `GetOption()->GetLength()` bytes).
          *
-         * @retval OT_ERROR_NONE        Successfully read and copied the Option Value into given buffer.
+         * @retval kErrorNone       Successfully read and copied the Option Value into given buffer.
-         * @retval OT_ERROR_NOT_FOUND   Iterator is done (not pointing to any option).
+         * @retval kErrorNotFound   Iterator is done (not pointing to any option).
          *
          */
-        otError ReadOptionValue(void *aValue) const;
+        Error ReadOptionValue(void *aValue) const;
 
         /**
          * This method read the current Option Value which is assumed to be an unsigned integer.
          *
          * @param[out]  aUintValue      A reference to `uint64_t` to output the read Option Value.
          *
-         * @retval OT_ERROR_NONE        Successfully read the Option value.
+         * @retval kErrorNone       Successfully read the Option value.
-         * @retval OT_ERROR_NO_BUFS     Value is too long to fit in an `uint64_t`.
+         * @retval kErrorNoBufs     Value is too long to fit in an `uint64_t`.
-         * @retval OT_ERROR_NOT_FOUND   Iterator is done (not pointing to any option).
+         * @retval kErrorNotFound   Iterator is done (not pointing to any option).
          *
          */
-        otError ReadOptionValue(uint64_t &aUintValue) const;
+        Error ReadOptionValue(uint64_t &aUintValue) const;
 
         /**
          * This method gets the offset of beginning of the CoAP message payload (after the CoAP header).
@@ -1189,9 +1189,9 @@ public:
         void MarkAsDone(void) { mOption.mLength = kIteratorDoneLength; }
         void MarkAsParseErrored(void) { MarkAsDone(), mNextOptionOffset = kNextOptionOffsetParseError; }
 
-        otError Read(uint16_t aLength, void *aBuffer);
+        Error Read(uint16_t aLength, void *aBuffer);
-        otError ReadExtendedOptionField(uint16_t &aValue);
+        Error ReadExtendedOptionField(uint16_t &aValue);
-        otError InitOrAdvance(const Message *aMessage, uint16_t aNumber);
+        Error InitOrAdvance(const Message *aMessage, uint16_t aNumber);
     };
 
     /**

src/core/coap/coap_secure.cpp

@@ -54,9 +54,9 @@ CoapSecure::CoapSecure(Instance &aInstance, bool aLayerTwoSecurity)
 {
 }
 
-otError CoapSecure::Start(uint16_t aPort)
+Error CoapSecure::Start(uint16_t aPort)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     mConnectedCallback = nullptr;
     mConnectedContext  = nullptr;
@@ -68,9 +68,9 @@ exit:
     return error;
 }
 
-otError CoapSecure::Start(MeshCoP::Dtls::TransportCallback aCallback, void *aContext)
+Error CoapSecure::Start(MeshCoP::Dtls::TransportCallback aCallback, void *aContext)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     mConnectedCallback = nullptr;
     mConnectedContext  = nullptr;
@@ -95,7 +95,7 @@ void CoapSecure::Stop(void)
     ClearRequestsAndResponses();
 }
 
-otError CoapSecure::Connect(const Ip6::SockAddr &aSockAddr, ConnectedCallback aCallback, void *aContext)
+Error CoapSecure::Connect(const Ip6::SockAddr &aSockAddr, ConnectedCallback aCallback, void *aContext)
 {
     mConnectedCallback = aCallback;
     mConnectedContext  = aContext;
@@ -105,7 +105,7 @@ otError CoapSecure::Connect(const Ip6::SockAddr &aSockAddr, ConnectedCallback aC
 
 void CoapSecure::SetPsk(const MeshCoP::JoinerPskd &aPskd)
 {
-    otError error;
+    Error error;
 
     OT_UNUSED_VARIABLE(error);
 
@@ -115,19 +115,19 @@ void CoapSecure::SetPsk(const MeshCoP::JoinerPskd &aPskd)
 
     error = mDtls.SetPsk(reinterpret_cast<const uint8_t *>(aPskd.GetAsCString()), aPskd.GetLength());
 
-    OT_ASSERT(error == OT_ERROR_NONE);
+    OT_ASSERT(error == kErrorNone);
 }
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-otError CoapSecure::SendMessage(Message &                   aMessage,
+Error CoapSecure::SendMessage(Message &                   aMessage,
-                                ResponseHandler             aHandler,
+                              ResponseHandler             aHandler,
-                                void *                      aContext,
+                              void *                      aContext,
-                                otCoapBlockwiseTransmitHook aTransmitHook,
+                              otCoapBlockwiseTransmitHook aTransmitHook,
-                                otCoapBlockwiseReceiveHook  aReceiveHook)
+                              otCoapBlockwiseReceiveHook  aReceiveHook)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsConnected(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsConnected(), error = kErrorInvalidState);
 
     error = CoapBase::SendMessage(aMessage, mDtls.GetMessageInfo(), TxParameters::GetDefault(), aHandler, aContext,
                                   aTransmitHook, aReceiveHook);
@@ -136,22 +136,22 @@ exit:
     return error;
 }
 
-otError CoapSecure::SendMessage(Message &                   aMessage,
+Error CoapSecure::SendMessage(Message &                   aMessage,
-                                const Ip6::MessageInfo &    aMessageInfo,
+                              const Ip6::MessageInfo &    aMessageInfo,
-                                ResponseHandler             aHandler,
+                              ResponseHandler             aHandler,
-                                void *                      aContext,
+                              void *                      aContext,
-                                otCoapBlockwiseTransmitHook aTransmitHook,
+                              otCoapBlockwiseTransmitHook aTransmitHook,
-                                otCoapBlockwiseReceiveHook  aReceiveHook)
+                              otCoapBlockwiseReceiveHook  aReceiveHook)
 {
     return CoapBase::SendMessage(aMessage, aMessageInfo, TxParameters::GetDefault(), aHandler, aContext, aTransmitHook,
                                  aReceiveHook);
 }
 #else  // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
-otError CoapSecure::SendMessage(Message &aMessage, ResponseHandler aHandler, void *aContext)
+Error CoapSecure::SendMessage(Message &aMessage, ResponseHandler aHandler, void *aContext)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsConnected(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsConnected(), error = kErrorInvalidState);
 
     error = CoapBase::SendMessage(aMessage, mDtls.GetMessageInfo(), aHandler, aContext);
 
@@ -159,23 +159,23 @@ exit:
     return error;
 }
 
-otError CoapSecure::SendMessage(Message &               aMessage,
+Error CoapSecure::SendMessage(Message &               aMessage,
-                                const Ip6::MessageInfo &aMessageInfo,
+                              const Ip6::MessageInfo &aMessageInfo,
-                                ResponseHandler         aHandler,
+                              ResponseHandler         aHandler,
-                                void *                  aContext)
+                              void *                  aContext)
 {
     return CoapBase::SendMessage(aMessage, aMessageInfo, aHandler, aContext);
 }
 #endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
-otError CoapSecure::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error CoapSecure::Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
     mTransmitQueue.Enqueue(aMessage);
     mTransmitTask.Post();
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 void CoapSecure::HandleDtlsConnected(void *aContext, bool aConnected)
@@ -216,7 +216,7 @@ void CoapSecure::HandleTransmit(Tasklet &aTasklet)
 
 void CoapSecure::HandleTransmit(void)
 {
-    otError      error   = OT_ERROR_NONE;
+    Error        error   = kErrorNone;
     ot::Message *message = mTransmitQueue.GetHead();
 
     VerifyOrExit(message != nullptr);
@@ -230,14 +230,14 @@ void CoapSecure::HandleTransmit(void)
     SuccessOrExit(error = mDtls.Send(*message, message->GetLength()));
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogNoteMeshCoP("CoapSecure Transmit: %s", otThreadErrorToString(error));
+        otLogNoteMeshCoP("CoapSecure Transmit: %s", ErrorToString(error));
         message->Free();
     }
     else
     {
-        otLogDebgMeshCoP("CoapSecure Transmit: %s", otThreadErrorToString(error));
+        otLogDebgMeshCoP("CoapSecure Transmit: %s", ErrorToString(error));
     }
 }
 

src/core/coap/coap_secure.hpp

@@ -72,11 +72,11 @@ public:
      *
      * @param[in]  aPort      The local UDP port to bind to.
      *
-     * @retval OT_ERROR_NONE        Successfully started the CoAP agent.
+     * @retval kErrorNone        Successfully started the CoAP agent.
-     * @retval OT_ERROR_ALREADY     Already started.
+     * @retval kErrorAlready     Already started.
      *
      */
-    otError Start(uint16_t aPort);
+    Error Start(uint16_t aPort);
 
     /**
      * This method starts the secure CoAP agent, but do not use socket to transmit/receive messages.
@@ -84,11 +84,11 @@ public:
      * @param[in]  aCallback  A pointer to a function for sending messages.
      * @param[in]  aContext   A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE        Successfully started the CoAP agent.
+     * @retval kErrorNone        Successfully started the CoAP agent.
-     * @retval OT_ERROR_ALREADY     Already started.
+     * @retval kErrorAlready     Already started.
      *
      */
-    otError Start(MeshCoP::Dtls::TransportCallback aCallback, void *aContext);
+    Error Start(MeshCoP::Dtls::TransportCallback aCallback, void *aContext);
 
     /**
      * This method sets connected callback of this secure CoAP agent.
@@ -116,10 +116,10 @@ public:
      * @param[in]  aCallback               A pointer to a function that will be called once DTLS connection is
      * established.
      *
-     * @retval OT_ERROR_NONE  Successfully started DTLS connection.
+     * @retval kErrorNone  Successfully started DTLS connection.
      *
      */
-    otError Connect(const Ip6::SockAddr &aSockAddr, ConnectedCallback aCallback, void *aContext);
+    Error Connect(const Ip6::SockAddr &aSockAddr, ConnectedCallback aCallback, void *aContext);
 
     /**
      * This method indicates whether or not the DTLS session is active.
@@ -159,11 +159,11 @@ public:
      * @param[in]  aPsk        A pointer to the PSK.
      * @param[in]  aPskLength  The PSK length.
      *
-     * @retval OT_ERROR_NONE          Successfully set the PSK.
+     * @retval kErrorNone         Successfully set the PSK.
-     * @retval OT_ERROR_INVALID_ARGS  The PSK is invalid.
+     * @retval kErrorInvalidArgs  The PSK is invalid.
      *
      */
-    otError SetPsk(const uint8_t *aPsk, uint8_t aPskLength) { return mDtls.SetPsk(aPsk, aPskLength); }
+    Error SetPsk(const uint8_t *aPsk, uint8_t aPskLength) { return mDtls.SetPsk(aPsk, aPskLength); }
 
     /**
      * This method sets the PSK.
@@ -238,11 +238,11 @@ public:
      * @param[out]  aCertLength      The length of the base64 encoded peer certificate.
      * @param[in]   aCertBufferSize  The buffer size of aPeerCert.
      *
-     * @retval OT_ERROR_NONE     Successfully get the peer certificate.
+     * @retval kErrorNone    Successfully get the peer certificate.
-     * @retval OT_ERROR_NO_BUFS  Can't allocate memory for certificate.
+     * @retval kErrorNoBufs  Can't allocate memory for certificate.
      *
      */
-    otError GetPeerCertificateBase64(unsigned char *aPeerCert, size_t *aCertLength, size_t aCertBufferSize)
+    Error GetPeerCertificateBase64(unsigned char *aPeerCert, size_t *aCertLength, size_t aCertBufferSize)
     {
         return mDtls.GetPeerCertificateBase64(aPeerCert, aCertLength, aCertBufferSize);
     }
@@ -286,16 +286,16 @@ public:
      * @param[in]  aTransmitHook A pointer to a hook function for outgoing block-wise transfer.
      * @param[in]  aReceiveHook  A pointer to a hook function for incoming block-wise transfer.
      *
-     * @retval OT_ERROR_NONE           Successfully sent CoAP message.
+     * @retval kErrorNone          Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS        Failed to allocate retransmission data.
+     * @retval kErrorNoBufs        Failed to allocate retransmission data.
-     * @retval OT_ERROR_INVALID_STATE  DTLS connection was not initialized.
+     * @retval kErrorInvalidState  DTLS connection was not initialized.
      *
      */
-    otError SendMessage(Message &                   aMessage,
+    Error SendMessage(Message &                   aMessage,
-                        ResponseHandler             aHandler      = nullptr,
+                      ResponseHandler             aHandler      = nullptr,
-                        void *                      aContext      = nullptr,
+                      void *                      aContext      = nullptr,
-                        otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
+                      otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
-                        otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
+                      otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
 
     /**
      * This method sends a CoAP message over secure DTLS connection.
@@ -311,17 +311,17 @@ public:
      * @param[in]  aTransmitHook A pointer to a hook function for outgoing block-wise transfer.
      * @param[in]  aReceiveHook  A pointer to a hook function for incoming block-wise transfer.
      *
-     * @retval OT_ERROR_NONE           Successfully sent CoAP message.
+     * @retval kErrorNone          Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS        Failed to allocate retransmission data.
+     * @retval kErrorNoBufs        Failed to allocate retransmission data.
-     * @retval OT_ERROR_INVALID_STATE  DTLS connection was not initialized.
+     * @retval kErrorInvalidState  DTLS connection was not initialized.
      *
      */
-    otError SendMessage(Message &                   aMessage,
+    Error SendMessage(Message &                   aMessage,
-                        const Ip6::MessageInfo &    aMessageInfo,
+                      const Ip6::MessageInfo &    aMessageInfo,
-                        ResponseHandler             aHandler      = nullptr,
+                      ResponseHandler             aHandler      = nullptr,
-                        void *                      aContext      = nullptr,
+                      void *                      aContext      = nullptr,
-                        otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
+                      otCoapBlockwiseTransmitHook aTransmitHook = nullptr,
-                        otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
+                      otCoapBlockwiseReceiveHook  aReceiveHook  = nullptr);
 #else  // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     /**
      * This method sends a CoAP message over secure DTLS connection.
@@ -334,12 +334,12 @@ public:
      * @param[in]  aHandler      A function pointer that shall be called on response reception or time-out.
      * @param[in]  aContext      A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE           Successfully sent CoAP message.
+     * @retval kErrorNone          Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS        Failed to allocate retransmission data.
+     * @retval kErrorNoBufs        Failed to allocate retransmission data.
-     * @retval OT_ERROR_INVALID_STATE  DTLS connection was not initialized.
+     * @retval kErrorInvalidState  DTLS connection was not initialized.
      *
      */
-    otError SendMessage(Message &aMessage, ResponseHandler aHandler = nullptr, void *aContext = nullptr);
+    Error SendMessage(Message &aMessage, ResponseHandler aHandler = nullptr, void *aContext = nullptr);
 
     /**
      * This method sends a CoAP message over secure DTLS connection.
@@ -353,15 +353,15 @@ public:
      * @param[in]  aHandler      A function pointer that shall be called on response reception or time-out.
      * @param[in]  aContext      A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE           Successfully sent CoAP message.
+     * @retval kErrorNone          Successfully sent CoAP message.
-     * @retval OT_ERROR_NO_BUFS        Failed to allocate retransmission data.
+     * @retval kErrorNoBufs        Failed to allocate retransmission data.
-     * @retval OT_ERROR_INVALID_STATE  DTLS connection was not initialized.
+     * @retval kErrorInvalidState  DTLS connection was not initialized.
      *
      */
-    otError SendMessage(Message &               aMessage,
+    Error SendMessage(Message &               aMessage,
-                        const Ip6::MessageInfo &aMessageInfo,
+                      const Ip6::MessageInfo &aMessageInfo,
-                        ResponseHandler         aHandler = nullptr,
+                      ResponseHandler         aHandler = nullptr,
-                        void *                  aContext = nullptr);
+                      void *                  aContext = nullptr);
 #endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
 
     /**
@@ -385,11 +385,11 @@ public:
     const Ip6::MessageInfo &GetMessageInfo(void) const { return mDtls.GetMessageInfo(); }
 
 private:
-    static otError Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+    static Error Send(CoapBase &aCoapBase, ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
     {
         return static_cast<CoapSecure &>(aCoapBase).Send(aMessage, aMessageInfo);
     }
-    otError Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    Error Send(ot::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
     static void HandleDtlsConnected(void *aContext, bool aConnected);
     void        HandleDtlsConnected(bool aConnected);

src/core/common/error.cpp

@@ -0,0 +1,85 @@
+/*
+ *  Copyright (c) 2016-2021, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file implements the error code functions used by OpenThread core modules.
+ */
+
+#include "error.hpp"
+
+#include "common/code_utils.hpp"
+
+namespace ot {
+
+const char *ErrorToString(Error aError)
+{
+    static const char *const kErrorStrings[kNumErrors] = {
+        "OK",                         // (0)  kErrorNone
+        "Failed",                     // (1)  kErrorFailed
+        "Drop",                       // (2)  kErrorDrop
+        "NoBufs",                     // (3)  kErrorNoBufs
+        "NoRoute",                    // (4)  kErrorNoRoute
+        "Busy",                       // (5)  kErrorBusy
+        "Parse",                      // (6)  kErrorParse
+        "InvalidArgs",                // (7)  kErrorInvalidArgs
+        "Security",                   // (8)  kErrorSecurity
+        "AddressQuery",               // (9)  kErrorAddressQuery
+        "NoAddress",                  // (10) kErrorNoAddress
+        "Abort",                      // (11) kErrorAbort
+        "NotImplemented",             // (12) kErrorNotImplemented
+        "InvalidState",               // (13) kErrorInvalidState
+        "NoAck",                      // (14) kErrorNoAck
+        "ChannelAccessFailure",       // (15) kErrorChannelAccessFailure
+        "Detached",                   // (16) kErrorDetached
+        "FcsErr",                     // (17) kErrorFcs
+        "NoFrameReceived",            // (18) kErrorNoFrameReceived
+        "UnknownNeighbor",            // (19) kErrorUnknownNeighbor
+        "InvalidSourceAddress",       // (20) kErrorInvalidSourceAddress
+        "AddressFiltered",            // (21) kErrorAddressFiltered
+        "DestinationAddressFiltered", // (22) kErrorDestinationAddressFiltered
+        "NotFound",                   // (23) kErrorNotFound
+        "Already",                    // (24) kErrorAlready
+        "ReservedError25",            // (25) Error 25 is reserved
+        "Ipv6AddressCreationFailure", // (26) kErrorIp6AddressCreationFailure
+        "NotCapable",                 // (27) kErrorNotCapable
+        "ResponseTimeout",            // (28) kErrorResponseTimeout
+        "Duplicated",                 // (29) kErrorDuplicated
+        "ReassemblyTimeout",          // (30) kErrorReassemblyTimeout
+        "NotTmf",                     // (31) kErrorNotTmf
+        "NonLowpanDataFrame",         // (32) kErrorNotLowpanDataFrame
+        "ReservedError33",            // (33) Error 33 is reserved
+        "LinkMarginLow",              // (34) kErrorLinkMarginLow
+        "InvalidCommand",             // (35) kErrorInvalidCommand
+        "Pending",                    // (36) kErrorPending
+    };
+
+    return aError < OT_ARRAY_LENGTH(kErrorStrings) ? kErrorStrings[aError] : "UnknownErrorType";
+}
+
+} // namespace ot

src/core/common/error.hpp

@@ -0,0 +1,107 @@
+/*
+ *  Copyright (c) 2021, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file defines the errors used by OpenThread core.
+ */
+
+#ifndef ERROR_HPP_
+#define ERROR_HPP_
+
+#include "openthread-core-config.h"
+
+#include <openthread/error.h>
+
+#include <stdint.h>
+
+namespace ot {
+
+/**
+ * This type represents error codes used by OpenThread core modules.
+ *
+ */
+typedef otError Error;
+
+/*
+ * The `OT_ERROR_*` enumeration values are re-defined using `kError` style format.
+ * See `openthread/error.h` for more details about each error.
+ *
+ */
+constexpr Error kErrorNone                       = OT_ERROR_NONE;
+constexpr Error kErrorFailed                     = OT_ERROR_FAILED;
+constexpr Error kErrorDrop                       = OT_ERROR_DROP;
+constexpr Error kErrorNoBufs                     = OT_ERROR_NO_BUFS;
+constexpr Error kErrorNoRoute                    = OT_ERROR_NO_ROUTE;
+constexpr Error kErrorBusy                       = OT_ERROR_BUSY;
+constexpr Error kErrorParse                      = OT_ERROR_PARSE;
+constexpr Error kErrorInvalidArgs                = OT_ERROR_INVALID_ARGS;
+constexpr Error kErrorSecurity                   = OT_ERROR_SECURITY;
+constexpr Error kErrorAddressQuery               = OT_ERROR_ADDRESS_QUERY;
+constexpr Error kErrorNoAddress                  = OT_ERROR_NO_ADDRESS;
+constexpr Error kErrorAbort                      = OT_ERROR_ABORT;
+constexpr Error kErrorNotImplemented             = OT_ERROR_NOT_IMPLEMENTED;
+constexpr Error kErrorInvalidState               = OT_ERROR_INVALID_STATE;
+constexpr Error kErrorNoAck                      = OT_ERROR_NO_ACK;
+constexpr Error kErrorChannelAccessFailure       = OT_ERROR_CHANNEL_ACCESS_FAILURE;
+constexpr Error kErrorDetached                   = OT_ERROR_DETACHED;
+constexpr Error kErrorFcs                        = OT_ERROR_FCS;
+constexpr Error kErrorNoFrameReceived            = OT_ERROR_NO_FRAME_RECEIVED;
+constexpr Error kErrorUnknownNeighbor            = OT_ERROR_UNKNOWN_NEIGHBOR;
+constexpr Error kErrorInvalidSourceAddress       = OT_ERROR_INVALID_SOURCE_ADDRESS;
+constexpr Error kErrorAddressFiltered            = OT_ERROR_ADDRESS_FILTERED;
+constexpr Error kErrorDestinationAddressFiltered = OT_ERROR_DESTINATION_ADDRESS_FILTERED;
+constexpr Error kErrorNotFound                   = OT_ERROR_NOT_FOUND;
+constexpr Error kErrorAlready                    = OT_ERROR_ALREADY;
+constexpr Error kErrorIp6AddressCreationFailure  = OT_ERROR_IP6_ADDRESS_CREATION_FAILURE;
+constexpr Error kErrorNotCapable                 = OT_ERROR_NOT_CAPABLE;
+constexpr Error kErrorResponseTimeout            = OT_ERROR_RESPONSE_TIMEOUT;
+constexpr Error kErrorDuplicated                 = OT_ERROR_DUPLICATED;
+constexpr Error kErrorReassemblyTimeout          = OT_ERROR_REASSEMBLY_TIMEOUT;
+constexpr Error kErrorNotTmf                     = OT_ERROR_NOT_TMF;
+constexpr Error kErrorNotLowpanDataFrame         = OT_ERROR_NOT_LOWPAN_DATA_FRAME;
+constexpr Error kErrorLinkMarginLow              = OT_ERROR_LINK_MARGIN_LOW;
+constexpr Error kErrorInvalidCommand             = OT_ERROR_INVALID_COMMAND;
+constexpr Error kErrorPending                    = OT_ERROR_PENDING;
+constexpr Error kErrorGeneric                    = OT_ERROR_GENERIC;
+
+constexpr uint8_t kNumErrors = OT_NUM_ERRORS;
+
+/**
+ * This function converts an `Error` into a string.
+ *
+ * @param[in]  aError     An error.
+ *
+ * @returns  A string representation of @p aError.
+ *
+ */
+const char *ErrorToString(Error aError);
+
+} // namespace ot
+
+#endif // ERROR_HPP_

src/core/common/instance.cpp

@@ -214,11 +214,11 @@ void Instance::FactoryReset(void)
     otPlatReset(this);
 }
 
-otError Instance::ErasePersistentInfo(void)
+Error Instance::ErasePersistentInfo(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(Get<Mle::MleRouter>().IsDisabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<Mle::MleRouter>().IsDisabled(), error = kErrorInvalidState);
     Get<Settings>().Wipe();
 
 exit:

src/core/common/instance.hpp

@@ -39,13 +39,13 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include <openthread/error.h>
 #include <openthread/heap.h>
 #include <openthread/platform/logging.h>
 #if OPENTHREAD_CONFIG_HEAP_EXTERNAL_ENABLE
 #include <openthread/platform/memory.h>
 #endif
 
+#include "common/error.hpp"
 #include "common/non_copyable.hpp"
 #include "common/random_manager.hpp"
 #include "common/tasklet.hpp"
@@ -238,11 +238,11 @@ public:
      *
      * Erase is successful/allowed only if the device is in `disabled` state/role.
      *
-     * @retval OT_ERROR_NONE           All persistent info/state was erased successfully.
+     * @retval kErrorNone          All persistent info/state was erased successfully.
-     * @retval OT_ERROR_INVALID_STATE  Device is not in `disabled` state/role.
+     * @retval kErrorInvalidState  Device is not in `disabled` state/role.
      *
      */
-    otError ErasePersistentInfo(void);
+    Error ErasePersistentInfo(void);
 
 #if OPENTHREAD_CONFIG_HEAP_EXTERNAL_ENABLE
     static void  HeapFree(void *aPointer) { otPlatFree(aPointer); }

src/core/common/linked_list.hpp

@@ -37,7 +37,8 @@
 #include "openthread-core-config.h"
 
 #include <stdio.h>
-#include <openthread/error.h>
+
+#include "common/error.hpp"
 
 namespace ot {
 
@@ -239,7 +240,7 @@ public:
     {
         const Type *prev;
 
-        return Find(aEntry, prev) == OT_ERROR_NONE;
+        return Find(aEntry, prev) == kErrorNone;
     }
 
     /**
@@ -267,17 +268,17 @@ public:
      *
      * @param[in] aEntry   A reference to an entry to add.
      *
-     * @retval OT_ERROR_NONE     The entry was successfully added at the head of the list.
+     * @retval kErrorNone     The entry was successfully added at the head of the list.
-     * @retval OT_ERROR_ALREADY  The entry is already in the list.
+     * @retval kErrorAlready  The entry is already in the list.
      *
      */
-    otError Add(Type &aEntry)
+    Error Add(Type &aEntry)
     {
-        otError error = OT_ERROR_NONE;
+        Error error = kErrorNone;
 
         if (Contains(aEntry))
         {
-            error = OT_ERROR_ALREADY;
+            error = kErrorAlready;
         }
         else
         {
@@ -295,16 +296,16 @@ public:
      *
      * @param[in] aEntry   A reference to an entry to remove.
      *
-     * @retval OT_ERROR_NONE       The entry was successfully removed from the list.
+     * @retval kErrorNone      The entry was successfully removed from the list.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the entry in the list.
+     * @retval kErrorNotFound  Could not find the entry in the list.
      *
      */
-    otError Remove(const Type &aEntry)
+    Error Remove(const Type &aEntry)
     {
-        Type *  prev;
+        Type *prev;
-        otError error = Find(aEntry, prev);
+        Error error = Find(aEntry, prev);
 
-        if (error == OT_ERROR_NONE)
+        if (error == kErrorNone)
         {
             PopAfter(prev);
         }
@@ -351,13 +352,13 @@ public:
      *                         @p aPrevEntry is set to nullptr if @p aEntry is the head of the list. Otherwise it is
      *                         updated to point to the previous entry before @p aEntry in the list.
      *
-     * @retval OT_ERROR_NONE       The entry was found in the list and @p aPrevEntry was updated successfully.
+     * @retval kErrorNone      The entry was found in the list and @p aPrevEntry was updated successfully.
-     * @retval OT_ERROR_NOT_FOUND  The entry was not found in the list.
+     * @retval kErrorNotFound  The entry was not found in the list.
      *
      */
-    otError Find(const Type &aEntry, const Type *&aPrevEntry) const
+    Error Find(const Type &aEntry, const Type *&aPrevEntry) const
     {
-        otError error = OT_ERROR_NOT_FOUND;
+        Error error = kErrorNotFound;
 
         aPrevEntry = nullptr;
 
@@ -365,7 +366,7 @@ public:
         {
             if (entry == &aEntry)
             {
-                error = OT_ERROR_NONE;
+                error = kErrorNone;
                 break;
             }
         }
@@ -381,11 +382,11 @@ public:
      *                         @p aPrevEntry is set to nullptr if @p aEntry is the head of the list. Otherwise it is
      *                         updated to point to the previous entry before @p aEntry in the list.
      *
-     * @retval OT_ERROR_NONE       The entry was found in the list and @p aPrevEntry was updated successfully.
+     * @retval kErrorNone      The entry was found in the list and @p aPrevEntry was updated successfully.
-     * @retval OT_ERROR_NOT_FOUND  The entry was not found in the list.
+     * @retval kErrorNotFound  The entry was not found in the list.
      *
      */
-    otError Find(const Type &aEntry, Type *&aPrevEntry)
+    Error Find(const Type &aEntry, Type *&aPrevEntry)
     {
         return const_cast<const LinkedList *>(this)->Find(aEntry, const_cast<const Type *&>(aPrevEntry));
     }

src/core/common/logging.cpp

@@ -101,7 +101,7 @@ static void Log(otLogLevel  aLogLevel,
 #endif // OPENTHREAD_CONFIG_LOG_PREPEND_LEVEL
 
     IgnoreError(logString.Append("%s", aRegionPrefix));
-    VerifyOrExit(logString.AppendVarArgs(aFormat, aArgs) != OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(logString.AppendVarArgs(aFormat, aArgs) != ot::kErrorInvalidArgs);
     otPlatLog(aLogLevel, aLogRegion, "%s" OPENTHREAD_CONFIG_LOG_SUFFIX, logString.AsCString());
 
 exit:
@@ -318,51 +318,6 @@ void otDump(otLogLevel, otLogRegion, const char *, const void *, const size_t)
 }
 #endif // OPENTHREAD_CONFIG_LOG_PKT_DUMP
 
-static const char *const sThreadErrorStrings[OT_NUM_ERRORS] = {
-    "OK",                         // OT_ERROR_NONE = 0
-    "Failed",                     // OT_ERROR_FAILED = 1
-    "Drop",                       // OT_ERROR_DROP = 2
-    "NoBufs",                     // OT_ERROR_NO_BUFS = 3
-    "NoRoute",                    // OT_ERROR_NO_ROUTE = 4
-    "Busy",                       // OT_ERROR_BUSY = 5
-    "Parse",                      // OT_ERROR_PARSE = 6
-    "InvalidArgs",                // OT_ERROR_INVALID_ARGS = 7
-    "Security",                   // OT_ERROR_SECURITY = 8
-    "AddressQuery",               // OT_ERROR_ADDRESS_QUERY = 9
-    "NoAddress",                  // OT_ERROR_NO_ADDRESS = 10
-    "Abort",                      // OT_ERROR_ABORT = 11
-    "NotImplemented",             // OT_ERROR_NOT_IMPLEMENTED = 12
-    "InvalidState",               // OT_ERROR_INVALID_STATE = 13
-    "NoAck",                      // OT_ERROR_NO_ACK = 14
-    "ChannelAccessFailure",       // OT_ERROR_CHANNEL_ACCESS_FAILURE = 15
-    "Detached",                   // OT_ERROR_DETACHED = 16
-    "FcsErr",                     // OT_ERROR_FCS = 17
-    "NoFrameReceived",            // OT_ERROR_NO_FRAME_RECEIVED = 18
-    "UnknownNeighbor",            // OT_ERROR_UNKNOWN_NEIGHBOR = 19
-    "InvalidSourceAddress",       // OT_ERROR_INVALID_SOURCE_ADDRESS = 20
-    "AddressFiltered",            // OT_ERROR_ADDRESS_FILTERED = 21
-    "DestinationAddressFiltered", // OT_ERROR_DESTINATION_ADDRESS_FILTERED = 22
-    "NotFound",                   // OT_ERROR_NOT_FOUND = 23
-    "Already",                    // OT_ERROR_ALREADY = 24
-    "ReservedError25",            // otError 25 is reserved
-    "Ipv6AddressCreationFailure", // OT_ERROR_IP6_ADDRESS_CREATION_FAILURE = 26
-    "NotCapable",                 // OT_ERROR_NOT_CAPABLE = 27
-    "ResponseTimeout",            // OT_ERROR_RESPONSE_TIMEOUT = 28
-    "Duplicated",                 // OT_ERROR_DUPLICATED = 29
-    "ReassemblyTimeout",          // OT_ERROR_REASSEMBLY_TIMEOUT = 30
-    "NotTmf",                     // OT_ERROR_NOT_TMF = 31
-    "NonLowpanDataFrame",         // OT_ERROR_NOT_LOWPAN_DATA_FRAME = 32
-    "ReservedError33",            // otError 33 is reserved
-    "LinkMarginLow",              // OT_ERROR_LINK_MARGIN_LOW = 34
-    "InvalidCommand",             // OT_ERROR_INVALID_COMMAND = 35
-    "Pending",                    // OT_ERROR_PENDING = 36
-};
-
-const char *otThreadErrorToString(otError aError)
-{
-    return aError < OT_ARRAY_LENGTH(sThreadErrorStrings) ? sThreadErrorStrings[aError] : "UnknownErrorType";
-}
-
 #if OPENTHREAD_CONFIG_LOG_DEFINE_AS_MACRO_ONLY
 
 const char *otLogLevelToPrefixString(otLogLevel aLogLevel)

src/core/common/logging.hpp

@@ -2558,7 +2558,7 @@ const char *otLogLevelToPrefixString(otLogLevel aLogLevel);
 /**
  * @def otLogResultPlat
  *
- * This function generates a log for the Plat region according to the error result. If @p aError is `OT_ERROR_NONE`, the
+ * This function generates a log for the Plat region according to the error result. If @p aError is `kErrorNone`, the
  * log level is info. Otherwise the log level is warn.
  *
  * @param[in]  aError    The error result.

src/core/common/message.cpp

@@ -66,7 +66,7 @@ MessagePool::MessagePool(Instance &aInstance)
 
 Message *MessagePool::New(Message::Type aType, uint16_t aReserveHeader, Message::Priority aPriority)
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     Message *message;
 
     VerifyOrExit((message = static_cast<Message *>(NewBuffer(aPriority))) != nullptr);
@@ -81,7 +81,7 @@ Message *MessagePool::New(Message::Type aType, uint16_t aReserveHeader, Message:
     SuccessOrExit(error = message->SetLength(0));
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         Free(message);
         message = nullptr;
@@ -158,7 +158,7 @@ void MessagePool::FreeBuffers(Buffer *aBuffer)
     }
 }
 
-otError MessagePool::ReclaimBuffers(Message::Priority aPriority)
+Error MessagePool::ReclaimBuffers(Message::Priority aPriority)
 {
     return Get<MeshForwarder>().EvictMessage(aPriority);
 }
@@ -201,9 +201,9 @@ Message::Settings::Settings(const otMessageSettings *aSettings)
 {
 }
 
-otError Message::ResizeMessage(uint16_t aLength)
+Error Message::ResizeMessage(uint16_t aLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     // add buffers
     Buffer * curBuffer = this;
@@ -215,7 +215,7 @@ otError Message::ResizeMessage(uint16_t aLength)
         if (curBuffer->GetNextBuffer() == nullptr)
         {
             curBuffer->SetNextBuffer(GetMessagePool()->NewBuffer(GetPriority()));
-            VerifyOrExit(curBuffer->GetNextBuffer() != nullptr, error = OT_ERROR_NO_BUFS);
+            VerifyOrExit(curBuffer->GetNextBuffer() != nullptr, error = kErrorNoBufs);
         }
 
         curBuffer = curBuffer->GetNextBuffer();
@@ -262,12 +262,12 @@ exit:
     return next;
 }
 
-otError Message::SetLength(uint16_t aLength)
+Error Message::SetLength(uint16_t aLength)
 {
-    otError  error              = OT_ERROR_NONE;
+    Error    error              = kErrorNone;
     uint16_t totalLengthRequest = GetReserved() + aLength;
 
-    VerifyOrExit(totalLengthRequest >= GetReserved(), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(totalLengthRequest >= GetReserved(), error = kErrorInvalidArgs);
 
     SuccessOrExit(error = ResizeMessage(totalLengthRequest));
     GetMetadata().mLength = aLength;
@@ -331,13 +331,13 @@ bool Message::IsSubTypeMle(void) const
     return rval;
 }
 
-otError Message::SetPriority(Priority aPriority)
+Error Message::SetPriority(Priority aPriority)
 {
-    otError        error         = OT_ERROR_NONE;
+    Error          error         = kErrorNone;
     uint8_t        priority      = static_cast<uint8_t>(aPriority);
     PriorityQueue *priorityQueue = nullptr;
 
-    VerifyOrExit(priority < kNumPriorities, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(priority < kNumPriorities, error = kErrorInvalidArgs);
 
     VerifyOrExit(IsInAQueue(), GetMetadata().mPriority = priority);
     VerifyOrExit(GetMetadata().mPriority != priority);
@@ -376,9 +376,9 @@ const char *Message::PriorityToString(Priority aPriority)
     return kPriorityStrings[aPriority];
 }
 
-otError Message::AppendBytes(const void *aBuf, uint16_t aLength)
+Error Message::AppendBytes(const void *aBuf, uint16_t aLength)
 {
-    otError  error     = OT_ERROR_NONE;
+    Error    error     = kErrorNone;
     uint16_t oldLength = GetLength();
 
     SuccessOrExit(error = SetLength(GetLength() + aLength));
@@ -388,14 +388,14 @@ exit:
     return error;
 }
 
-otError Message::PrependBytes(const void *aBuf, uint16_t aLength)
+Error Message::PrependBytes(const void *aBuf, uint16_t aLength)
 {
-    otError error     = OT_ERROR_NONE;
+    Error   error     = kErrorNone;
     Buffer *newBuffer = nullptr;
 
     while (aLength > GetReserved())
     {
-        VerifyOrExit((newBuffer = GetMessagePool()->NewBuffer(GetPriority())) != nullptr, error = OT_ERROR_NO_BUFS);
+        VerifyOrExit((newBuffer = GetMessagePool()->NewBuffer(GetPriority())) != nullptr, error = kErrorNoBufs);
 
         newBuffer->SetNextBuffer(GetNextBuffer());
         SetNextBuffer(newBuffer);
@@ -541,9 +541,9 @@ uint16_t Message::ReadBytes(uint16_t aOffset, void *aBuf, uint16_t aLength) cons
     return static_cast<uint16_t>(bufPtr - reinterpret_cast<uint8_t *>(aBuf));
 }
 
-otError Message::Read(uint16_t aOffset, void *aBuf, uint16_t aLength) const
+Error Message::Read(uint16_t aOffset, void *aBuf, uint16_t aLength) const
 {
-    return (ReadBytes(aOffset, aBuf, aLength) == aLength) ? OT_ERROR_NONE : OT_ERROR_PARSE;
+    return (ReadBytes(aOffset, aBuf, aLength) == aLength) ? kErrorNone : kErrorParse;
 }
 
 bool Message::CompareBytes(uint16_t aOffset, const void *aBuf, uint16_t aLength) const
@@ -632,12 +632,12 @@ uint16_t Message::CopyTo(uint16_t aSourceOffset, uint16_t aDestinationOffset, ui
 
 Message *Message::Clone(uint16_t aLength) const
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     Message *messageCopy;
     uint16_t offset;
 
     VerifyOrExit((messageCopy = GetMessagePool()->New(GetType(), GetReserved(), GetPriority())) != nullptr,
-                 error = OT_ERROR_NO_BUFS);
+                 error = kErrorNoBufs);
     SuccessOrExit(error = messageCopy->SetLength(aLength));
     CopyTo(0, 0, aLength, *messageCopy);
 

src/core/common/message.hpp

@@ -100,38 +100,38 @@ class HmacSha256;
     } while (false)
 
 /**
- * This macro frees a given message buffer if a given `otError` indicates an error.
+ * This macro frees a given message buffer if a given `Error` indicates an error.
  *
  * The parameter @p aMessage can be nullptr in which case this macro does nothing.
  *
  * @param[in] aMessage    A pointer to a `Message` to free (can be nullptr).
- * @param[in] aError      The `otError` to check.
+ * @param[in] aError      The `Error` to check.
  *
  */
-#define FreeMessageOnError(aMessage, aError)                        \
+#define FreeMessageOnError(aMessage, aError)                     \
-    do                                                              \
+    do                                                           \
-    {                                                               \
+    {                                                            \
-        if (((aError) != OT_ERROR_NONE) && ((aMessage) != nullptr)) \
+        if (((aError) != kErrorNone) && ((aMessage) != nullptr)) \
-        {                                                           \
+        {                                                        \
-            (aMessage)->Free();                                     \
+            (aMessage)->Free();                                  \
-        }                                                           \
+        }                                                        \
     } while (false)
 
 /**
- * This macro frees a given message buffer if a given `otError` indicates an error and sets the `aMessage` to `nullptr`.
+ * This macro frees a given message buffer if a given `Error` indicates an error and sets the `aMessage` to `nullptr`.
  *
  * @param[in] aMessage    A pointer to a `Message` to free (can be nullptr).
- * @param[in] aError      The `otError` to check.
+ * @param[in] aError      The `Error` to check.
  *
  */
-#define FreeAndNullMessageOnError(aMessage, aError)                 \
+#define FreeAndNullMessageOnError(aMessage, aError)              \
-    do                                                              \
+    do                                                           \
-    {                                                               \
+    {                                                            \
-        if (((aError) != OT_ERROR_NONE) && ((aMessage) != nullptr)) \
+        if (((aError) != kErrorNone) && ((aMessage) != nullptr)) \
-        {                                                           \
+        {                                                        \
-            (aMessage)->Free();                                     \
+            (aMessage)->Free();                                  \
-            (aMessage) = nullptr;                                   \
+            (aMessage) = nullptr;                                \
-        }                                                           \
+        }                                                        \
     } while (false)
 
 enum
@@ -477,11 +477,11 @@ public:
      *
      * @param[in]  aLength  Requested number of bytes in the message.
      *
-     * @retval OT_ERROR_NONE     Successfully set the length of the message.
+     * @retval kErrorNone    Successfully set the length of the message.
-     * @retval OT_ERROR_NO_BUFS  Failed to grow the size of the message because insufficient buffers were available.
+     * @retval kErrorNoBufs  Failed to grow the size of the message because insufficient buffers were available.
      *
      */
-    otError SetLength(uint16_t aLength);
+    Error SetLength(uint16_t aLength);
 
     /**
      * This method returns the number of buffers in the message.
@@ -586,11 +586,11 @@ public:
      *
      * @param[in]  aPriority  The message priority level.
      *
-     * @retval OT_ERROR_NONE           Successfully set the priority for the message.
+     * @retval kErrorNone          Successfully set the priority for the message.
-     * @retval OT_ERROR_INVALID_ARGS   Priority level is not invalid.
+     * @retval kErrorInvalidArgs   Priority level is not invalid.
      *
      */
-    otError SetPriority(Priority aPriority);
+    Error SetPriority(Priority aPriority);
 
     /**
      * This static method convert a `Priority` to a string.
@@ -610,11 +610,11 @@ public:
      * @param[in]  aBuf     A pointer to a data buffer (can be `nullptr` to grow message without writing bytes).
      * @param[in]  aLength  The number of bytes to prepend.
      *
-     * @retval OT_ERROR_NONE     Successfully prepended the bytes.
+     * @retval kErrorNone    Successfully prepended the bytes.
-     * @retval OT_ERROR_NO_BUFS  Not enough reserved bytes in the message.
+     * @retval kErrorNoBufs  Not enough reserved bytes in the message.
      *
      */
-    otError PrependBytes(const void *aBuf, uint16_t aLength);
+    Error PrependBytes(const void *aBuf, uint16_t aLength);
 
     /**
      * This method prepends an object to the front of the message.
@@ -625,11 +625,11 @@ public:
      *
      * @param[in] aObject      A reference to the object to prepend to the message.
      *
-     * @retval OT_ERROR_NONE     Successfully prepended the object.
+     * @retval kErrorNone    Successfully prepended the object.
-     * @retval OT_ERROR_NO_BUFS  Not enough reserved bytes in the message.
+     * @retval kErrorNoBufs  Not enough reserved bytes in the message.
      *
      */
-    template <typename ObjectType> otError Prepend(const ObjectType &aObject)
+    template <typename ObjectType> Error Prepend(const ObjectType &aObject)
     {
         static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer");
 
@@ -652,11 +652,11 @@ public:
      * @param[in]  aBuf     A pointer to a data buffer (MUST not be `nullptr`).
      * @param[in]  aLength  The number of bytes to append.
      *
-     * @retval OT_ERROR_NONE     Successfully appended the bytes.
+     * @retval kErrorNone    Successfully appended the bytes.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs  Insufficient available buffers to grow the message.
      *
      */
-    otError AppendBytes(const void *aBuf, uint16_t aLength);
+    Error AppendBytes(const void *aBuf, uint16_t aLength);
 
     /**
      * This method appends an object to the end of the message.
@@ -667,11 +667,11 @@ public:
      *
      * @param[in] aObject      A reference to the object to append to the message.
      *
-     * @retval OT_ERROR_NONE     Successfully appended the object.
+     * @retval kErrorNone    Successfully appended the object.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs  Insufficient available buffers to grow the message.
      *
      */
-    template <typename ObjectType> otError Append(const ObjectType &aObject)
+    template <typename ObjectType> Error Append(const ObjectType &aObject)
     {
         static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer");
 
@@ -694,23 +694,23 @@ public:
      * This method reads a given number of bytes from the message.
      *
      * If there are fewer bytes available in the message than the requested read length, the available bytes will be
-     * read and copied into @p aBuf. In this case `OT_ERROR_PARSE` will be returned.
+     * read and copied into @p aBuf. In this case `kErrorParse` will be returned.
      *
      * @param[in]  aOffset  Byte offset within the message to begin reading.
      * @param[out] aBuf     A pointer to a data buffer to copy the read bytes into.
      * @param[in]  aLength  Number of bytes to read.
      *
-     * @retval OT_ERROR_NONE     @p aLength bytes were successfully read from message.
+     * @retval kErrorNone     @p aLength bytes were successfully read from message.
-     * @retval OT_ERROR_PARSE    Not enough bytes remaining in message to read the entire object.
+     * @retval kErrorParse    Not enough bytes remaining in message to read the entire object.
      *
      */
-    otError Read(uint16_t aOffset, void *aBuf, uint16_t aLength) const;
+    Error Read(uint16_t aOffset, void *aBuf, uint16_t aLength) const;
 
     /**
      * This method reads an object from the message.
      *
      * If there are fewer bytes available in the message than the requested object size, the available bytes will be
-     * read and copied into @p aObject (@p aObject will be read partially). In this case `OT_ERROR_PARSE` will
+     * read and copied into @p aObject (@p aObject will be read partially). In this case `kErrorParse` will
      * be returned.
      *
      * @tparam     ObjectType   The object type to read from the message.
@@ -718,11 +718,11 @@ public:
      * @param[in]  aOffset      Byte offset within the message to begin reading.
      * @param[out] aObject      A reference to the object to read into.
      *
-     * @retval OT_ERROR_NONE     Object @p aObject was successfully read from message.
+     * @retval kErrorNone     Object @p aObject was successfully read from message.
-     * @retval OT_ERROR_PARSE    Not enough bytes remaining in message to read the entire object.
+     * @retval kErrorParse    Not enough bytes remaining in message to read the entire object.
      *
      */
-    template <typename ObjectType> otError Read(uint16_t aOffset, ObjectType &aObject) const
+    template <typename ObjectType> Error Read(uint16_t aOffset, ObjectType &aObject) const
     {
         static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer");
 
@@ -1333,11 +1333,11 @@ private:
      *
      * @param[in]  aLength  The number of bytes that the message buffer needs to handle.
      *
-     * @retval OT_ERROR_NONE     Successfully resized the message.
+     * @retval kErrorNone    Successfully resized the message.
-     * @retval OT_ERROR_NO_BUFS  Could not grow the message due to insufficient available message buffers.
+     * @retval kErrorNoBufs  Could not grow the message due to insufficient available message buffers.
      *
      */
-    otError ResizeMessage(uint16_t aLength);
+    Error ResizeMessage(uint16_t aLength);
 
 private:
     struct Chunk
@@ -1627,7 +1627,7 @@ public:
 private:
     Buffer *NewBuffer(Message::Priority aPriority);
     void    FreeBuffers(Buffer *aBuffer);
-    otError ReclaimBuffers(Message::Priority aPriority);
+    Error   ReclaimBuffers(Message::Priority aPriority);
 
 #if !OPENTHREAD_CONFIG_PLATFORM_MESSAGE_MANAGEMENT && !OPENTHREAD_CONFIG_MESSAGE_USE_HEAP_ENABLE
     uint16_t                  mNumFreeBuffers;

src/core/common/notifier.cpp

@@ -52,9 +52,9 @@ Notifier::Notifier(Instance &aInstance)
     }
 }
 
-otError Notifier::RegisterCallback(otStateChangedCallback aCallback, void *aContext)
+Error Notifier::RegisterCallback(otStateChangedCallback aCallback, void *aContext)
 {
-    otError           error          = OT_ERROR_NONE;
+    Error             error          = kErrorNone;
     ExternalCallback *unusedCallback = nullptr;
 
     VerifyOrExit(aCallback != nullptr);
@@ -71,10 +71,10 @@ otError Notifier::RegisterCallback(otStateChangedCallback aCallback, void *aCont
             continue;
         }
 
-        VerifyOrExit((callback.mHandler != aCallback) || (callback.mContext != aContext), error = OT_ERROR_ALREADY);
+        VerifyOrExit((callback.mHandler != aCallback) || (callback.mContext != aContext), error = kErrorAlready);
     }
 
-    VerifyOrExit(unusedCallback != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(unusedCallback != nullptr, error = kErrorNoBufs);
 
     unusedCallback->mHandler = aCallback;
     unusedCallback->mContext = aContext;

src/core/common/notifier.hpp

@@ -42,6 +42,7 @@
 #include <openthread/instance.h>
 #include <openthread/platform/toolchain.h>
 
+#include "common/error.hpp"
 #include "common/locator.hpp"
 #include "common/non_copyable.hpp"
 #include "common/tasklet.hpp"
@@ -210,12 +211,12 @@ public:
      * @param[in]  aCallback     A pointer to the handler function that is called to notify of the changes.
      * @param[in]  aContext      A pointer to arbitrary context information.
      *
-     * @retval OT_ERROR_NONE     Successfully registered the callback.
+     * @retval kErrorNone     Successfully registered the callback.
-     * @retval OT_ERROR_ALREADY  The callback was already registered.
+     * @retval kErrorAlready  The callback was already registered.
-     * @retval OT_ERROR_NO_BUFS  Could not add the callback due to resource constraints.
+     * @retval kErrorNoBufs   Could not add the callback due to resource constraints.
      *
      */
-    otError RegisterCallback(otStateChangedCallback aCallback, void *aContext);
+    Error RegisterCallback(otStateChangedCallback aCallback, void *aContext);
 
     /**
      * This method removes/unregisters a previously registered `otStateChangedCallback` handler.
@@ -264,7 +265,7 @@ public:
     /**
      * This template method updates a variable of a type `Type` with a new value and signals the given event.
      *
-     * If the variable is already set to the same value, this method returns `OT_ERROR_ALREADY` and the event is
+     * If the variable is already set to the same value, this method returns `kErrorAlready` and the event is
      * signaled using `SignalIfFirst()` (i.e., signal is scheduled only if event has not been signaled before).
      *
      * The template `Type` should support comparison operator `==` and assignment operator `=`.
@@ -273,18 +274,18 @@ public:
      * @param[in]    aNewValue    The new value.
      * @param[in]    aEvent       The event to signal.
      *
-     * @retval OT_ERROR_NONE      The variable was update successfully and @p aEvent was signaled.
+     * @retval kErrorNone      The variable was update successfully and @p aEvent was signaled.
-     * @retval OT_ERROR_ALREADY   The variable was already set to the same value.
+     * @retval kErrorAlready   The variable was already set to the same value.
      *
      */
-    template <typename Type> otError Update(Type &aVariable, const Type &aNewValue, Event aEvent)
+    template <typename Type> Error Update(Type &aVariable, const Type &aNewValue, Event aEvent)
     {
-        otError error = OT_ERROR_NONE;
+        Error error = kErrorNone;
 
         if (aVariable == aNewValue)
         {
             SignalIfFirst(aEvent);
-            error = OT_ERROR_ALREADY;
+            error = kErrorAlready;
         }
         else
         {

src/core/common/random.hpp

@@ -38,9 +38,8 @@
 
 #include <stdint.h>
 
-#include <openthread/error.h>
-
 #include "common/debug.hpp"
+#include "common/error.hpp"
 #include "common/random_manager.hpp"
 
 namespace ot {
@@ -170,10 +169,10 @@ namespace Crypto {
  * @param[out] aBuffer  A pointer to a buffer to fill with the random bytes.
  * @param[in]  aSize    Size of buffer (number of bytes to fill).
  *
- * @retval OT_ERROR_NONE    Successfully filled buffer with random values.
+ * @retval kErrorNone    Successfully filled buffer with random values.
  *
  */
-inline otError FillBuffer(uint8_t *aBuffer, uint16_t aSize)
+inline Error FillBuffer(uint8_t *aBuffer, uint16_t aSize)
 {
     return RandomManager::CryptoFillBuffer(aBuffer, aSize);
 }

src/core/common/random_manager.cpp

@@ -58,7 +58,7 @@ RandomManager::CryptoCtrDrbg RandomManager::sCtrDrbg;
 RandomManager::RandomManager(void)
 {
     uint32_t seed;
-    otError  error;
+    Error    error;
 
     OT_UNUSED_VARIABLE(error);
 
@@ -71,10 +71,10 @@ RandomManager::RandomManager(void)
     sCtrDrbg.Init();
 
     error = Random::Crypto::FillBuffer(reinterpret_cast<uint8_t *>(&seed), sizeof(seed));
-    OT_ASSERT(error == OT_ERROR_NONE);
+    OT_ASSERT(error == kErrorNone);
 #else
     error = otPlatEntropyGet(reinterpret_cast<uint8_t *>(&seed), sizeof(seed));
-    OT_ASSERT(error == OT_ERROR_NONE);
+    OT_ASSERT(error == kErrorNone);
 #endif
 
     sPrng.Init(seed);
@@ -211,7 +211,7 @@ void RandomManager::CryptoCtrDrbg::Deinit(void)
     mbedtls_ctr_drbg_free(&mCtrDrbg);
 }
 
-otError RandomManager::CryptoCtrDrbg::FillBuffer(uint8_t *aBuffer, uint16_t aSize)
+Error RandomManager::CryptoCtrDrbg::FillBuffer(uint8_t *aBuffer, uint16_t aSize)
 {
     return ot::Crypto::MbedTls::MapError(
         mbedtls_ctr_drbg_random(&mCtrDrbg, static_cast<unsigned char *>(aBuffer), static_cast<size_t>(aSize)));

src/core/common/random_manager.hpp

@@ -37,13 +37,13 @@
 #include "openthread-core-config.h"
 
 #include <stdint.h>
-#include <openthread/error.h>
 
 #if !OPENTHREAD_RADIO
 #include <mbedtls/ctr_drbg.h>
 #include <mbedtls/entropy.h>
 #endif
 
+#include "common/error.hpp"
 #include "common/non_copyable.hpp"
 
 #if (!defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES) && \
@@ -94,10 +94,10 @@ public:
      * @param[out] aBuffer  A pointer to a buffer to fill with the random bytes.
      * @param[in]  aSize    Size of buffer (number of bytes to fill).
      *
-     * @retval OT_ERROR_NONE    Successfully filled buffer with random values.
+     * @retval kErrorNone    Successfully filled buffer with random values.
      *
      */
-    static otError CryptoFillBuffer(uint8_t *aBuffer, uint16_t aSize) { return sCtrDrbg.FillBuffer(aBuffer, aSize); }
+    static Error CryptoFillBuffer(uint8_t *aBuffer, uint16_t aSize) { return sCtrDrbg.FillBuffer(aBuffer, aSize); }
 
     /**
      * This static method returns the initialized mbedtls_ctr_drbg_context.
@@ -139,9 +139,9 @@ private:
     class CryptoCtrDrbg
     {
     public:
-        void    Init(void);
+        void  Init(void);
-        void    Deinit(void);
+        void  Deinit(void);
-        otError FillBuffer(uint8_t *aBuffer, uint16_t aSize);
+        Error FillBuffer(uint8_t *aBuffer, uint16_t aSize);
 
         mbedtls_ctr_drbg_context *GetContext(void) { return &mCtrDrbg; }
 

src/core/common/settings.cpp

@@ -95,11 +95,11 @@ void SettingsBase::LogPrefix(const char *aAction, const char *aPrefixName, const
 
 #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_WARN)
 
-void SettingsBase::LogFailure(otError error, const char *aText, bool aIsDelete) const
+void SettingsBase::LogFailure(Error error, const char *aText, bool aIsDelete) const
 {
-    if ((error != OT_ERROR_NONE) && (!aIsDelete || (error != OT_ERROR_NOT_FOUND)))
+    if ((error != kErrorNone) && (!aIsDelete || (error != kErrorNotFound)))
     {
-        otLogWarnCore("Non-volatile: Error %s %s", otThreadErrorToString(error), aText);
+        otLogWarnCore("Non-volatile: Error %s %s", ErrorToString(error), aText);
     }
 }
 
@@ -130,22 +130,22 @@ void SettingsDriver::SetCriticalKeys(const uint16_t *aKeys, uint16_t aKeysLength
     otPlatSettingsSetCriticalKeys(&GetInstance(), aKeys, aKeysLength);
 }
 
-otError SettingsDriver::Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
+Error SettingsDriver::Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
 {
     return otPlatSettingsAdd(&GetInstance(), aKey, aValue, aValueLength);
 }
 
-otError SettingsDriver::Delete(uint16_t aKey, int aIndex)
+Error SettingsDriver::Delete(uint16_t aKey, int aIndex)
 {
     return otPlatSettingsDelete(&GetInstance(), aKey, aIndex);
 }
 
-otError SettingsDriver::Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const
+Error SettingsDriver::Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const
 {
     return otPlatSettingsGet(&GetInstance(), aKey, aIndex, aValue, aValueLength);
 }
 
-otError SettingsDriver::Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
+Error SettingsDriver::Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
 {
     return otPlatSettingsSet(&GetInstance(), aKey, aValue, aValueLength);
 }
@@ -178,22 +178,22 @@ void SettingsDriver::SetCriticalKeys(const uint16_t *aKeys, uint16_t aKeysLength
     OT_UNUSED_VARIABLE(aKeysLength);
 }
 
-otError SettingsDriver::Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
+Error SettingsDriver::Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
 {
     return mFlash.Add(aKey, aValue, aValueLength);
 }
 
-otError SettingsDriver::Delete(uint16_t aKey, int aIndex)
+Error SettingsDriver::Delete(uint16_t aKey, int aIndex)
 {
     return mFlash.Delete(aKey, aIndex);
 }
 
-otError SettingsDriver::Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const
+Error SettingsDriver::Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const
 {
     return mFlash.Get(aKey, aIndex, aValue, aValueLength);
 }
 
-otError SettingsDriver::Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
+Error SettingsDriver::Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength)
 {
     return mFlash.Set(aKey, aValue, aValueLength);
 }
@@ -222,21 +222,21 @@ void Settings::Wipe(void)
     otLogInfoCore("Non-volatile: Wiped all info");
 }
 
-otError Settings::SaveOperationalDataset(bool aIsActive, const MeshCoP::Dataset &aDataset)
+Error Settings::SaveOperationalDataset(bool aIsActive, const MeshCoP::Dataset &aDataset)
 {
-    otError error = Save(aIsActive ? kKeyActiveDataset : kKeyPendingDataset, aDataset.GetBytes(), aDataset.GetSize());
+    Error error = Save(aIsActive ? kKeyActiveDataset : kKeyPendingDataset, aDataset.GetBytes(), aDataset.GetSize());
 
     LogFailure(error, "saving OperationalDataset", false);
     return error;
 }
 
-otError Settings::ReadOperationalDataset(bool aIsActive, MeshCoP::Dataset &aDataset) const
+Error Settings::ReadOperationalDataset(bool aIsActive, MeshCoP::Dataset &aDataset) const
 {
-    otError  error  = OT_ERROR_NONE;
+    Error    error  = kErrorNone;
     uint16_t length = MeshCoP::Dataset::kMaxSize;
 
     SuccessOrExit(error = Read(aIsActive ? kKeyActiveDataset : kKeyPendingDataset, aDataset.GetBytes(), length));
-    VerifyOrExit(length <= MeshCoP::Dataset::kMaxSize, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(length <= MeshCoP::Dataset::kMaxSize, error = kErrorNotFound);
 
     aDataset.SetSize(length);
 
@@ -244,18 +244,18 @@ exit:
     return error;
 }
 
-otError Settings::DeleteOperationalDataset(bool aIsActive)
+Error Settings::DeleteOperationalDataset(bool aIsActive)
 {
-    otError error = Delete(aIsActive ? kKeyActiveDataset : kKeyPendingDataset);
+    Error error = Delete(aIsActive ? kKeyActiveDataset : kKeyPendingDataset);
 
     LogFailure(error, "deleting OperationalDataset", true);
 
     return error;
 }
 
-otError Settings::ReadNetworkInfo(NetworkInfo &aNetworkInfo) const
+Error Settings::ReadNetworkInfo(NetworkInfo &aNetworkInfo) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = sizeof(NetworkInfo);
 
     aNetworkInfo.Init();
@@ -266,13 +266,13 @@ exit:
     return error;
 }
 
-otError Settings::SaveNetworkInfo(const NetworkInfo &aNetworkInfo)
+Error Settings::SaveNetworkInfo(const NetworkInfo &aNetworkInfo)
 {
-    otError     error = OT_ERROR_NONE;
+    Error       error = kErrorNone;
     NetworkInfo prevNetworkInfo;
     uint16_t    length = sizeof(prevNetworkInfo);
 
-    if ((Read(kKeyNetworkInfo, &prevNetworkInfo, length) == OT_ERROR_NONE) && (length == sizeof(NetworkInfo)) &&
+    if ((Read(kKeyNetworkInfo, &prevNetworkInfo, length) == kErrorNone) && (length == sizeof(NetworkInfo)) &&
         (prevNetworkInfo == aNetworkInfo))
     {
         LogNetworkInfo("Re-saved", aNetworkInfo);
@@ -287,9 +287,9 @@ exit:
     return error;
 }
 
-otError Settings::DeleteNetworkInfo(void)
+Error Settings::DeleteNetworkInfo(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Delete(kKeyNetworkInfo));
     otLogInfoCore("Non-volatile: Deleted NetworkInfo");
@@ -299,9 +299,9 @@ exit:
     return error;
 }
 
-otError Settings::ReadParentInfo(ParentInfo &aParentInfo) const
+Error Settings::ReadParentInfo(ParentInfo &aParentInfo) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = sizeof(ParentInfo);
 
     aParentInfo.Init();
@@ -312,13 +312,13 @@ exit:
     return error;
 }
 
-otError Settings::SaveParentInfo(const ParentInfo &aParentInfo)
+Error Settings::SaveParentInfo(const ParentInfo &aParentInfo)
 {
-    otError    error = OT_ERROR_NONE;
+    Error      error = kErrorNone;
     ParentInfo prevParentInfo;
     uint16_t   length = sizeof(ParentInfo);
 
-    if ((Read(kKeyParentInfo, &prevParentInfo, length) == OT_ERROR_NONE) && (length == sizeof(ParentInfo)) &&
+    if ((Read(kKeyParentInfo, &prevParentInfo, length) == kErrorNone) && (length == sizeof(ParentInfo)) &&
         (prevParentInfo == aParentInfo))
     {
         LogParentInfo("Re-saved", aParentInfo);
@@ -333,9 +333,9 @@ exit:
     return error;
 }
 
-otError Settings::DeleteParentInfo(void)
+Error Settings::DeleteParentInfo(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Delete(kKeyParentInfo));
     otLogInfoCore("Non-volatile: Deleted ParentInfo");
@@ -345,9 +345,9 @@ exit:
     return error;
 }
 
-otError Settings::AddChildInfo(const ChildInfo &aChildInfo)
+Error Settings::AddChildInfo(const ChildInfo &aChildInfo)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Add(kKeyChildInfo, &aChildInfo, sizeof(aChildInfo)));
     LogChildInfo("Added", aChildInfo);
@@ -357,9 +357,9 @@ exit:
     return error;
 }
 
-otError Settings::DeleteAllChildInfo(void)
+Error Settings::DeleteAllChildInfo(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Delete(kKeyChildInfo));
     otLogInfoCore("Non-volatile: Deleted all ChildInfo");
@@ -386,11 +386,11 @@ void Settings::ChildInfoIterator::Advance(void)
     }
 }
 
-otError Settings::ChildInfoIterator::Delete(void)
+Error Settings::ChildInfoIterator::Delete(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(!mIsDone, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!mIsDone, error = kErrorInvalidState);
     SuccessOrExit(error = Get<SettingsDriver>().Delete(kKeyChildInfo, mIndex));
     LogChildInfo("Removed", mChildInfo);
 
@@ -402,7 +402,7 @@ exit:
 void Settings::ChildInfoIterator::Read(void)
 {
     uint16_t length = sizeof(ChildInfo);
-    otError  error;
+    Error    error;
 
     mChildInfo.Init();
     SuccessOrExit(
@@ -410,13 +410,13 @@ void Settings::ChildInfoIterator::Read(void)
     LogChildInfo("Read", mChildInfo);
 
 exit:
-    mIsDone = (error != OT_ERROR_NONE);
+    mIsDone = (error != kErrorNone);
 }
 
 #if OPENTHREAD_CONFIG_DUA_ENABLE
-otError Settings::ReadDadInfo(DadInfo &aDadInfo) const
+Error Settings::ReadDadInfo(DadInfo &aDadInfo) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = sizeof(DadInfo);
 
     aDadInfo.Init();
@@ -427,13 +427,13 @@ exit:
     return error;
 }
 
-otError Settings::SaveDadInfo(const DadInfo &aDadInfo)
+Error Settings::SaveDadInfo(const DadInfo &aDadInfo)
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     DadInfo  prevDadInfo;
     uint16_t length = sizeof(DadInfo);
 
-    if ((Read(kKeyDadInfo, &prevDadInfo, length) == OT_ERROR_NONE) && (length == sizeof(DadInfo)) &&
+    if ((Read(kKeyDadInfo, &prevDadInfo, length) == kErrorNone) && (length == sizeof(DadInfo)) &&
         (prevDadInfo == aDadInfo))
     {
         LogDadInfo("Re-saved", aDadInfo);
@@ -448,9 +448,9 @@ exit:
     return error;
 }
 
-otError Settings::DeleteDadInfo(void)
+Error Settings::DeleteDadInfo(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Delete(kKeyDadInfo));
     otLogInfoCore("Non-volatile: Deleted DadInfo");
@@ -462,13 +462,13 @@ exit:
 #endif // OPENTHREAD_CONFIG_DUA_ENABLE
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
-otError Settings::SaveOmrPrefix(const Ip6::Prefix &aOmrPrefix)
+Error Settings::SaveOmrPrefix(const Ip6::Prefix &aOmrPrefix)
 {
-    otError     error = OT_ERROR_NONE;
+    Error       error = kErrorNone;
     Ip6::Prefix prevOmrPrefix;
     uint16_t    length = sizeof(prevOmrPrefix);
 
-    if ((Read(kKeyOmrPrefix, &prevOmrPrefix, length) == OT_ERROR_NONE) && (length == sizeof(prevOmrPrefix)) &&
+    if ((Read(kKeyOmrPrefix, &prevOmrPrefix, length) == kErrorNone) && (length == sizeof(prevOmrPrefix)) &&
         (prevOmrPrefix == aOmrPrefix))
     {
         LogPrefix("Re-saved", "OMR prefix", aOmrPrefix);
@@ -483,9 +483,9 @@ exit:
     return error;
 }
 
-otError Settings::ReadOmrPrefix(Ip6::Prefix &aOmrPrefix) const
+Error Settings::ReadOmrPrefix(Ip6::Prefix &aOmrPrefix) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = sizeof(aOmrPrefix);
 
     aOmrPrefix.Clear();
@@ -496,13 +496,13 @@ exit:
     return error;
 }
 
-otError Settings::SaveOnLinkPrefix(const Ip6::Prefix &aOnLinkPrefix)
+Error Settings::SaveOnLinkPrefix(const Ip6::Prefix &aOnLinkPrefix)
 {
-    otError     error = OT_ERROR_NONE;
+    Error       error = kErrorNone;
     Ip6::Prefix prevOnLinkPrefix;
     uint16_t    length = sizeof(prevOnLinkPrefix);
 
-    if ((Read(kKeyOnLinkPrefix, &prevOnLinkPrefix, length) == OT_ERROR_NONE) && (length == sizeof(prevOnLinkPrefix)) &&
+    if ((Read(kKeyOnLinkPrefix, &prevOnLinkPrefix, length) == kErrorNone) && (length == sizeof(prevOnLinkPrefix)) &&
         (prevOnLinkPrefix == aOnLinkPrefix))
     {
         LogPrefix("Re-saved", "on-link prefix", aOnLinkPrefix);
@@ -517,9 +517,9 @@ exit:
     return error;
 }
 
-otError Settings::ReadOnLinkPrefix(Ip6::Prefix &aOnLinkPrefix) const
+Error Settings::ReadOnLinkPrefix(Ip6::Prefix &aOnLinkPrefix) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = sizeof(aOnLinkPrefix);
 
     aOnLinkPrefix.Clear();
@@ -533,9 +533,9 @@ exit:
 
 #if OPENTHREAD_CONFIG_SRP_CLIENT_ENABLE
 
-otError Settings::SaveSrpKey(const Crypto::Ecdsa::P256::KeyPair &aKeyPair)
+Error Settings::SaveSrpKey(const Crypto::Ecdsa::P256::KeyPair &aKeyPair)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     SuccessOrExit(error = Save(kKeySrpEcdsaKey, aKeyPair.GetDerBytes(), aKeyPair.GetDerLength()));
     otLogInfoCore("Non-volatile: Saved SRP key");
@@ -545,13 +545,13 @@ exit:
     return error;
 }
 
-otError Settings::ReadSrpKey(Crypto::Ecdsa::P256::KeyPair &aKeyPair) const
+Error Settings::ReadSrpKey(Crypto::Ecdsa::P256::KeyPair &aKeyPair) const
 {
-    otError  error;
+    Error    error;
     uint16_t length = Crypto::Ecdsa::P256::KeyPair::kMaxDerSize;
 
     SuccessOrExit(error = Read(kKeySrpEcdsaKey, aKeyPair.GetDerBytes(), length));
-    VerifyOrExit(length <= Crypto::Ecdsa::P256::KeyPair::kMaxDerSize, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(length <= Crypto::Ecdsa::P256::KeyPair::kMaxDerSize, error = kErrorNotFound);
     aKeyPair.SetDerLength(static_cast<uint8_t>(length));
     otLogInfoCore("Non-volatile: Read SRP key");
 
@@ -559,9 +559,9 @@ exit:
     return error;
 }
 
-otError Settings::DeleteSrpKey(void)
+Error Settings::DeleteSrpKey(void)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = Delete(kKeySrpEcdsaKey));
     otLogInfoCore("Non-volatile: Deleted SRP key");
@@ -573,22 +573,22 @@ exit:
 
 #endif // OPENTHREAD_CONFIG_SRP_CLIENT_ENABLE
 
-otError Settings::Read(Key aKey, void *aBuffer, uint16_t &aSize) const
+Error Settings::Read(Key aKey, void *aBuffer, uint16_t &aSize) const
 {
     return Get<SettingsDriver>().Get(aKey, 0, reinterpret_cast<uint8_t *>(aBuffer), &aSize);
 }
 
-otError Settings::Save(Key aKey, const void *aValue, uint16_t aSize)
+Error Settings::Save(Key aKey, const void *aValue, uint16_t aSize)
 {
     return Get<SettingsDriver>().Set(aKey, reinterpret_cast<const uint8_t *>(aValue), aSize);
 }
 
-otError Settings::Add(Key aKey, const void *aValue, uint16_t aSize)
+Error Settings::Add(Key aKey, const void *aValue, uint16_t aSize)
 {
     return Get<SettingsDriver>().Add(aKey, reinterpret_cast<const uint8_t *>(aValue), aSize);
 }
 
-otError Settings::Delete(Key aKey)
+Error Settings::Delete(Key aKey)
 {
     return Get<SettingsDriver>().Delete(aKey, -1);
 }

src/core/common/settings.hpp

@@ -96,11 +96,11 @@ public:
      *                           MUST NOT be nullptr if @p aValueLength is non-zero.
      * @param[in]  aValueLength  The length of the data pointed to by @p aValue. May be zero.
      *
-     * @retval OT_ERROR_NONE     The value was added.
+     * @retval kErrorNone     The value was added.
-     * @retval OT_ERROR_NO_BUFS  Not enough space to store the value.
+     * @retval kErrorNoBufs   Not enough space to store the value.
      *
      */
-    otError Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength);
+    Error Add(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength);
 
     /**
      * This method removes a value from @p aKey.
@@ -109,11 +109,11 @@ public:
      * @param[in] aIndex  The index of the value to be removed.
      *                    If set to -1, all values for @p aKey will be removed.
      *
-     * @retval OT_ERROR_NONE       The given key and index was found and removed successfully.
+     * @retval kErrorNone       The given key and index was found and removed successfully.
-     * @retval OT_ERROR_NOT_FOUND  The given key or index was not found.
+     * @retval kErrorNotFound   The given key or index was not found.
      *
      */
-    otError Delete(uint16_t aKey, int aIndex);
+    Error Delete(uint16_t aKey, int aIndex);
 
     /**
      * This method fetches the value identified by @p aKey.
@@ -128,11 +128,11 @@ public:
      *                              At return, the actual length of the setting is written.
      *                              May be nullptr if performing a presence check.
      *
-     * @retval OT_ERROR_NONE        The value was fetched successfully.
+     * @retval kErrorNone        The value was fetched successfully.
-     * @retval OT_ERROR_NOT_FOUND   The key was not found.
+     * @retval kErrorNotFound    The key was not found.
      *
      */
-    otError Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const;
+    Error Get(uint16_t aKey, int aIndex, uint8_t *aValue, uint16_t *aValueLength) const;
 
     /**
      * This method sets or replaces the value identified by @p aKey.
@@ -145,11 +145,11 @@ public:
      *                           MUST NOT be nullptr if @p aValueLength is non-zero.
      * @param[in]  aValueLength  The length of the data pointed to by @p aValue. May be zero.
      *
-     * @retval OT_ERROR_NONE     The value was changed.
+     * @retval kErrorNone     The value was changed.
-     * @retval OT_ERROR_NO_BUFS  Not enough space to store the value.
+     * @retval kErrorNoBufs   Not enough space to store the value.
      *
      */
-    otError Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength);
+    Error Set(uint16_t aKey, const uint8_t *aValue, uint16_t aValueLength);
 
     /**
      * This method remves all values.
@@ -637,9 +637,9 @@ protected:
 #endif // (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_INFO) && (OPENTHREAD_CONFIG_LOG_UTIL != 0)
 
 #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_WARN) && (OPENTHREAD_CONFIG_LOG_UTIL != 0)
-    void LogFailure(otError aError, const char *aAction, bool aIsDelete) const;
+    void LogFailure(Error aError, const char *aAction, bool aIsDelete) const;
 #else
-    void LogFailure(otError, const char *, bool) const {}
+    void LogFailure(Error, const char *, bool) const {}
 #endif
 };
 
@@ -691,11 +691,11 @@ public:
      * @param[in]   aIsActive   Indicates whether Dataset is active or pending.
      * @param[in]   aDataset    A reference to a `Dataset` object to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the Dataset.
+     * @retval kErrorNone             Successfully saved the Dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveOperationalDataset(bool aIsActive, const MeshCoP::Dataset &aDataset);
+    Error SaveOperationalDataset(bool aIsActive, const MeshCoP::Dataset &aDataset);
 
     /**
      * This method reads the Operational Dataset (active or pending).
@@ -703,87 +703,87 @@ public:
      * @param[in]   aIsActive             Indicates whether Dataset is active or pending.
      * @param[out]  aDataset              A reference to a `Dataset` object to output the read content.
      *
-     * @retval OT_ERROR_NONE              Successfully read the Dataset.
+     * @retval kErrorNone             Successfully read the Dataset.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadOperationalDataset(bool aIsActive, MeshCoP::Dataset &aDataset) const;
+    Error ReadOperationalDataset(bool aIsActive, MeshCoP::Dataset &aDataset) const;
 
     /**
      * This method deletes the Operational Dataset (active/pending) from settings.
      *
      * @param[in]   aIsActive            Indicates whether Dataset is active or pending.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the Dataset.
+     * @retval kErrorNone            Successfully deleted the Dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteOperationalDataset(bool aIsActive);
+    Error DeleteOperationalDataset(bool aIsActive);
 
     /**
      * This method saves Network Info.
      *
      * @param[in]   aNetworkInfo          A reference to a `NetworkInfo` structure to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved Network Info in settings.
+     * @retval kErrorNone             Successfully saved Network Info in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveNetworkInfo(const NetworkInfo &aNetworkInfo);
+    Error SaveNetworkInfo(const NetworkInfo &aNetworkInfo);
 
     /**
      * This method reads Network Info.
      *
      * @param[out]   aNetworkInfo         A reference to a `NetworkInfo` structure to output the read content.
      *
-     * @retval OT_ERROR_NONE              Successfully read the Network Info.
+     * @retval kErrorNone             Successfully read the Network Info.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadNetworkInfo(NetworkInfo &aNetworkInfo) const;
+    Error ReadNetworkInfo(NetworkInfo &aNetworkInfo) const;
 
     /**
      * This method deletes Network Info from settings.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteNetworkInfo(void);
+    Error DeleteNetworkInfo(void);
 
     /**
      * This method saves Parent Info.
      *
      * @param[in]   aParentInfo           A reference to a `ParentInfo` structure to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved Parent Info in settings.
+     * @retval kErrorNone             Successfully saved Parent Info in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveParentInfo(const ParentInfo &aParentInfo);
+    Error SaveParentInfo(const ParentInfo &aParentInfo);
 
     /**
      * This method reads Parent Info.
      *
      * @param[out]   aParentInfo         A reference to a `ParentInfo` structure to output the read content.
      *
-     * @retval OT_ERROR_NONE              Successfully read the Parent Info.
+     * @retval kErrorNone             Successfully read the Parent Info.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadParentInfo(ParentInfo &aParentInfo) const;
+    Error ReadParentInfo(ParentInfo &aParentInfo) const;
 
     /**
      * This method deletes Parent Info from settings.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteParentInfo(void);
+    Error DeleteParentInfo(void);
 
 #if OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE
 
@@ -792,11 +792,11 @@ public:
      *
      * @param[in]   aKey                  The SLAAC IID secret key.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the value.
+     * @retval kErrorNone             Successfully saved the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveSlaacIidSecretKey(const Utils::Slaac::IidSecretKey &aKey)
+    Error SaveSlaacIidSecretKey(const Utils::Slaac::IidSecretKey &aKey)
     {
         return Save(kKeySlaacIidSecretKey, &aKey, sizeof(Utils::Slaac::IidSecretKey));
     }
@@ -806,12 +806,12 @@ public:
      *
      * @param[out]   aKey          A reference to a SLAAC IID secret key to output the read value.
      *
-     * @retval OT_ERROR_NONE              Successfully read the value.
+     * @retval kErrorNone             Successfully read the value.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadSlaacIidSecretKey(Utils::Slaac::IidSecretKey &aKey)
+    Error ReadSlaacIidSecretKey(Utils::Slaac::IidSecretKey &aKey)
     {
         uint16_t length = sizeof(aKey);
 
@@ -821,11 +821,11 @@ public:
     /**
      * This method deletes the SLAAC IID secret key value from settings.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteSlaacIidSecretKey(void) { return Delete(kKeySlaacIidSecretKey); }
+    Error DeleteSlaacIidSecretKey(void) { return Delete(kKeySlaacIidSecretKey); }
 
 #endif // OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE
 
@@ -836,22 +836,22 @@ public:
      *
      * @param[in]   aChildInfo            A reference to a `ChildInfo` structure to be saved/added.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the Child Info in settings.
+     * @retval kErrorNone             Successfully saved the Child Info in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError AddChildInfo(const ChildInfo &aChildInfo);
+    Error AddChildInfo(const ChildInfo &aChildInfo);
 
     /**
      * This method deletes all Child Info entries from the settings.
      *
      * @note Child Info is a list-based settings property and can contain multiple entries.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteAllChildInfo(void);
+    Error DeleteAllChildInfo(void);
 
     /**
      * This method enables range-based `for` loop iteration over all child info entries in the `Settings`.
@@ -921,12 +921,12 @@ public:
         /**
          * This method deletes the current Child Info entry.
          *
-         * @retval OT_ERROR_NONE             The entry was deleted successfully.
+         * @retval kErrorNone            The entry was deleted successfully.
-         * @retval OT_ERROR_INVALID_STATE    The entry is not valid (iterator has reached end of list).
+         * @retval kErrorInvalidState    The entry is not valid (iterator has reached end of list).
-         * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+         * @retval kErrorNotImplemented  The platform does not implement settings functionality.
          *
          */
-        otError Delete(void);
+        Error Delete(void);
 
         /**
          * This method overloads the `*` dereference operator and gets a reference to `ChildInfo` entry to which the
@@ -994,32 +994,32 @@ public:
      *
      * @param[in]   aDadInfo           A reference to a `DadInfo` structure to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved duplicate address detection information in settings.
+     * @retval kErrorNone             Successfully saved duplicate address detection information in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveDadInfo(const DadInfo &aDadInfo);
+    Error SaveDadInfo(const DadInfo &aDadInfo);
 
     /**
      * This method reads duplicate address detection information.
      *
      * @param[out]   aDadInfo         A reference to a `DadInfo` structure to output the read content.
      *
-     * @retval OT_ERROR_NONE              Successfully read the duplicate address detection information.
+     * @retval kErrorNone             Successfully read the duplicate address detection information.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadDadInfo(DadInfo &aDadInfo) const;
+    Error ReadDadInfo(DadInfo &aDadInfo) const;
 
     /**
      * This method deletes duplicate address detection information from settings.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteDadInfo(void);
+    Error DeleteDadInfo(void);
 
 #endif // OPENTHREAD_CONFIG_DUA_ENABLE
 
@@ -1029,46 +1029,46 @@ public:
      *
      * @param[in]  aOmrPrefix  An OMR prefix to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the OMR prefix in settings.
+     * @retval kErrorNone             Successfully saved the OMR prefix in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveOmrPrefix(const Ip6::Prefix &aOmrPrefix);
+    Error SaveOmrPrefix(const Ip6::Prefix &aOmrPrefix);
 
     /**
      * This method reads OMR prefix.
      *
      * @param[out]  aOmrPrefix  A reference to a `Ip6::Prefix` structure to output the OMR prefix.
      *
-     * @retval OT_ERROR_NONE             Successfully read the OMR prefix.
+     * @retval kErrorNone            Successfully read the OMR prefix.
-     * @retval OT_ERROR_NOT_FOUND        No corresponding value in the setting store.
+     * @retval kErrorNotFound        No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError ReadOmrPrefix(Ip6::Prefix &aOmrPrefix) const;
+    Error ReadOmrPrefix(Ip6::Prefix &aOmrPrefix) const;
 
     /**
      * This method saves on-link prefix.
      *
      * @param[in]  aOnLinkPrefix  An on-link prefix to be saved.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the on-link prefix in settings.
+     * @retval kErrorNone             Successfully saved the on-link prefix in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveOnLinkPrefix(const Ip6::Prefix &aOnLinkPrefix);
+    Error SaveOnLinkPrefix(const Ip6::Prefix &aOnLinkPrefix);
 
     /**
      * This method reads on-link prefix.
      *
      * @param[out]  aOnLinkPrefix  A reference to a `Ip6::Prefix` structure to output the on-link prefix.
      *
-     * @retval OT_ERROR_NONE             Successfully read the on-link prefix.
+     * @retval kErrorNone            Successfully read the on-link prefix.
-     * @retval OT_ERROR_NOT_FOUND        No corresponding value in the setting store.
+     * @retval kErrorNotFound        No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError ReadOnLinkPrefix(Ip6::Prefix &aOnLinkPrefix) const;
+    Error ReadOnLinkPrefix(Ip6::Prefix &aOnLinkPrefix) const;
 #endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 
 #if OPENTHREAD_CONFIG_SRP_CLIENT_ENABLE
@@ -1077,32 +1077,32 @@ public:
      *
      * @param[in]   aKeyPair              A reference to an SRP ECDSA key-pair to save.
      *
-     * @retval OT_ERROR_NONE              Successfully saved key-pair information in settings.
+     * @retval kErrorNone             Successfully saved key-pair information in settings.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError SaveSrpKey(const Crypto::Ecdsa::P256::KeyPair &aKeyPair);
+    Error SaveSrpKey(const Crypto::Ecdsa::P256::KeyPair &aKeyPair);
 
     /**
      * This method reads SRP client ECDSA key pair.
      *
      * @param[out]   aKeyPair             A reference to a ECDA `KeyPair` to output the read content.
      *
-     * @retval OT_ERROR_NONE              Successfully read key-pair information.
+     * @retval kErrorNone             Successfully read key-pair information.
-     * @retval OT_ERROR_NOT_FOUND         No corresponding value in the setting store.
+     * @retval kErrorNotFound         No corresponding value in the setting store.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError ReadSrpKey(Crypto::Ecdsa::P256::KeyPair &aKeyPair) const;
+    Error ReadSrpKey(Crypto::Ecdsa::P256::KeyPair &aKeyPair) const;
 
     /**
      * This method deletes SRP client ECDSA key pair from settings.
      *
-     * @retval OT_ERROR_NONE             Successfully deleted the value.
+     * @retval kErrorNone            Successfully deleted the value.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError DeleteSrpKey(void);
+    Error DeleteSrpKey(void);
 #endif // OPENTHREAD_CONFIG_SRP_CLIENT_ENABLE
 
 private:
@@ -1118,10 +1118,10 @@ private:
         ChildInfoIterator end(void) { return ChildInfoIterator(GetInstance(), ChildInfoIterator::kEndIterator); }
     };
 
-    otError Read(Key aKey, void *aBuffer, uint16_t &aSize) const;
+    Error Read(Key aKey, void *aBuffer, uint16_t &aSize) const;
-    otError Save(Key aKey, const void *aValue, uint16_t aSize);
+    Error Save(Key aKey, const void *aValue, uint16_t aSize);
-    otError Add(Key aKey, const void *aValue, uint16_t aSize);
+    Error Add(Key aKey, const void *aValue, uint16_t aSize);
-    otError Delete(Key aKey);
+    Error Delete(Key aKey);
 };
 
 } // namespace ot

src/core/common/string.cpp

@@ -65,10 +65,10 @@ const char *StringFind(const char *aString, char aChar)
     return ret;
 }
 
-otError StringBase::Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, const char *aFormat, va_list aArgs)
+Error StringBase::Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, const char *aFormat, va_list aArgs)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    int     len;
+    int   len;
 
     len = vsnprintf(aBuffer + aLength, aSize - aLength, aFormat, aArgs);
 
@@ -76,12 +76,12 @@ otError StringBase::Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, cons
     {
         aLength    = 0;
         aBuffer[0] = 0;
-        error      = OT_ERROR_INVALID_ARGS;
+        error      = kErrorInvalidArgs;
     }
     else if (len >= aSize - aLength)
     {
         aLength = aSize - 1;
-        error   = OT_ERROR_NO_BUFS;
+        error   = kErrorNoBufs;
     }
     else
     {

src/core/common/string.hpp

@@ -40,9 +40,8 @@
 #include <stdint.h>
 #include <stdio.h>
 
-#include <openthread/error.h>
-
 #include "common/code_utils.hpp"
+#include "common/error.hpp"
 
 namespace ot {
 
@@ -95,11 +94,11 @@ protected:
      * @param[in]    aFormat  A pointer to the format string.
      * @param[in]    aArgs    Arguments for the format specification.
      *
-     * @retval OT_ERROR_NONE           Updated the string successfully.
+     * @retval kErrorNone          Updated the string successfully.
-     * @retval OT_ERROR_NO_BUFS        String could not fit in the storage.
+     * @retval kErrorNoBufs        String could not fit in the storage.
-     * @retval OT_ERROR_INVALID_ARGS   Arguments do not match the format string.
+     * @retval kErrorInvalidArgs   Arguments do not match the format string.
      */
-    static otError Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, const char *aFormat, va_list aArgs);
+    static Error Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, const char *aFormat, va_list aArgs);
 };
 
 /**
@@ -182,15 +181,15 @@ public:
      * @param[in] aFormat    A pointer to the format string.
      * @param[in] ...        Arguments for the format specification.
      *
-     * @retval OT_ERROR_NONE           Updated the string successfully.
+     * @retval kErrorNone          Updated the string successfully.
-     * @retval OT_ERROR_NO_BUFS        String could not fit in the storage.
+     * @retval kErrorNoBufs        String could not fit in the storage.
-     * @retval OT_ERROR_INVALID_ARGS   Arguments do not match the format string.
+     * @retval kErrorInvalidArgs   Arguments do not match the format string.
      *
      */
-    otError Set(const char *aFormat, ...)
+    Error Set(const char *aFormat, ...)
     {
         va_list args;
-        otError error;
+        Error   error;
 
         va_start(args, aFormat);
         mLength = 0;
@@ -206,15 +205,15 @@ public:
      * @param[in] aFormat    A pointer to the format string.
      * @param[in] ...        Arguments for the format specification.
      *
-     * @retval OT_ERROR_NONE           Updated the string successfully.
+     * @retval kErrorNone          Updated the string successfully.
-     * @retval OT_ERROR_NO_BUFS        String could not fit in the storage.
+     * @retval kErrorNoBufs        String could not fit in the storage.
-     * @retval OT_ERROR_INVALID_ARGS   Arguments do not match the format string.
+     * @retval kErrorInvalidArgs   Arguments do not match the format string.
      *
      */
-    otError Append(const char *aFormat, ...)
+    Error Append(const char *aFormat, ...)
     {
         va_list args;
-        otError error;
+        Error   error;
 
         va_start(args, aFormat);
         error = Write(mBuffer, kSize, mLength, aFormat, args);
@@ -229,12 +228,12 @@ public:
      * @param[in] aFormat    A pointer to the format string.
      * @param[in] aArgs      Arguments for the format specification (as `va_list`).
      *
-     * @retval OT_ERROR_NONE           Updated the string successfully.
+     * @retval kErrorNone          Updated the string successfully.
-     * @retval OT_ERROR_NO_BUFS        String could not fit in the storage.
+     * @retval kErrorNoBufs        String could not fit in the storage.
-     * @retval OT_ERROR_INVALID_ARGS   Arguments do not match the format string.
+     * @retval kErrorInvalidArgs   Arguments do not match the format string.
      *
      */
-    otError AppendVarArgs(const char *aFormat, va_list aArgs) { return Write(mBuffer, kSize, mLength, aFormat, aArgs); }
+    Error AppendVarArgs(const char *aFormat, va_list aArgs) { return Write(mBuffer, kSize, mLength, aFormat, aArgs); }
 
     /**
      * This method appends an array of bytes in hex representation (using "%02x" style) to the `String` object.
@@ -242,13 +241,13 @@ public:
      * @param[in] aBytes    A pointer to buffer containing the bytes to append.
      * @param[in] aLength   The length of @p aBytes buffer (in bytes).
      *
-     * @retval OT_ERROR_NONE           Updated the string successfully.
+     * @retval kErrorNone          Updated the string successfully.
-     * @retval OT_ERROR_NO_BUFS        String could not fit in the storage.
+     * @retval kErrorNoBufs        String could not fit in the storage.
      *
      */
-    otError AppendHexBytes(const uint8_t *aBytes, uint16_t aLength)
+    Error AppendHexBytes(const uint8_t *aBytes, uint16_t aLength)
     {
-        otError error = OT_ERROR_NONE;
+        Error error = kErrorNone;
 
         while (aLength--)
         {

src/core/common/tlvs.cpp

@@ -55,14 +55,14 @@ const uint8_t *Tlv::GetValue(void) const
     return reinterpret_cast<const uint8_t *>(this) + (IsExtended() ? sizeof(ExtendedTlv) : sizeof(Tlv));
 }
 
-otError Tlv::AppendTo(Message &aMessage) const
+Error Tlv::AppendTo(Message &aMessage) const
 {
     return aMessage.AppendBytes(this, static_cast<uint16_t>(GetSize()));
 }
 
-otError Tlv::FindTlv(const Message &aMessage, uint8_t aType, uint16_t aMaxSize, Tlv &aTlv)
+Error Tlv::FindTlv(const Message &aMessage, uint8_t aType, uint16_t aMaxSize, Tlv &aTlv)
 {
-    otError  error;
+    Error    error;
     uint16_t offset;
     uint16_t size;
 
@@ -79,14 +79,14 @@ exit:
     return error;
 }
 
-otError Tlv::FindTlvOffset(const Message &aMessage, uint8_t aType, uint16_t &aOffset)
+Error Tlv::FindTlvOffset(const Message &aMessage, uint8_t aType, uint16_t &aOffset)
 {
     return Find(aMessage, aType, &aOffset, nullptr, nullptr);
 }
 
-otError Tlv::FindTlvValueOffset(const Message &aMessage, uint8_t aType, uint16_t &aValueOffset, uint16_t &aLength)
+Error Tlv::FindTlvValueOffset(const Message &aMessage, uint8_t aType, uint16_t &aValueOffset, uint16_t &aLength)
 {
-    otError  error;
+    Error    error;
     uint16_t offset;
     uint16_t size;
     bool     isExtendedTlv;
@@ -108,9 +108,9 @@ exit:
     return error;
 }
 
-otError Tlv::Find(const Message &aMessage, uint8_t aType, uint16_t *aOffset, uint16_t *aSize, bool *aIsExtendedTlv)
+Error Tlv::Find(const Message &aMessage, uint8_t aType, uint16_t *aOffset, uint16_t *aSize, bool *aIsExtendedTlv)
 {
-    otError  error        = OT_ERROR_NOT_FOUND;
+    Error    error        = kErrorNotFound;
     uint16_t offset       = aMessage.GetOffset();
     uint16_t remainingLen = aMessage.GetLength();
     Tlv      tlv;
@@ -156,7 +156,7 @@ otError Tlv::Find(const Message &aMessage, uint8_t aType, uint16_t *aOffset, uin
                 *aIsExtendedTlv = (tlv.mLength == kExtendedLength);
             }
 
-            error = OT_ERROR_NONE;
+            error = kErrorNone;
             ExitNow();
         }
 
@@ -168,9 +168,9 @@ exit:
     return error;
 }
 
-template <typename UintType> otError Tlv::ReadUintTlv(const Message &aMessage, uint16_t aOffset, UintType &aValue)
+template <typename UintType> Error Tlv::ReadUintTlv(const Message &aMessage, uint16_t aOffset, UintType &aValue)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = ReadTlv(aMessage, aOffset, &aValue, sizeof(aValue)));
     aValue = Encoding::BigEndian::HostSwap<UintType>(aValue);
@@ -180,18 +180,18 @@ exit:
 }
 
 // Explicit instantiations of `ReadUintTlv<>()`
-template otError Tlv::ReadUintTlv<uint8_t>(const Message &aMessage, uint16_t aOffset, uint8_t &aValue);
+template Error Tlv::ReadUintTlv<uint8_t>(const Message &aMessage, uint16_t aOffset, uint8_t &aValue);
-template otError Tlv::ReadUintTlv<uint16_t>(const Message &aMessage, uint16_t aOffset, uint16_t &aValue);
+template Error Tlv::ReadUintTlv<uint16_t>(const Message &aMessage, uint16_t aOffset, uint16_t &aValue);
-template otError Tlv::ReadUintTlv<uint32_t>(const Message &aMessage, uint16_t aOffset, uint32_t &aValue);
+template Error Tlv::ReadUintTlv<uint32_t>(const Message &aMessage, uint16_t aOffset, uint32_t &aValue);
 
-otError Tlv::ReadTlv(const Message &aMessage, uint16_t aOffset, void *aValue, uint8_t aMinLength)
+Error Tlv::ReadTlv(const Message &aMessage, uint16_t aOffset, void *aValue, uint8_t aMinLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    Tlv     tlv;
+    Tlv   tlv;
 
     SuccessOrExit(error = aMessage.Read(aOffset, tlv));
-    VerifyOrExit(!tlv.IsExtended() && (tlv.GetLength() >= aMinLength), error = OT_ERROR_PARSE);
+    VerifyOrExit(!tlv.IsExtended() && (tlv.GetLength() >= aMinLength), error = kErrorParse);
-    VerifyOrExit(tlv.GetSize() + aOffset <= aMessage.GetLength(), error = OT_ERROR_PARSE);
+    VerifyOrExit(tlv.GetSize() + aOffset <= aMessage.GetLength(), error = kErrorParse);
 
     aMessage.ReadBytes(aOffset + sizeof(Tlv), aValue, aMinLength);
 
@@ -199,9 +199,9 @@ exit:
     return error;
 }
 
-template <typename UintType> otError Tlv::FindUintTlv(const Message &aMessage, uint8_t aType, UintType &aValue)
+template <typename UintType> Error Tlv::FindUintTlv(const Message &aMessage, uint8_t aType, UintType &aValue)
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     uint16_t offset;
 
     SuccessOrExit(error = FindTlvOffset(aMessage, aType, offset));
@@ -212,25 +212,25 @@ exit:
 }
 
 // Explicit instantiations of `FindUintTlv<>()`
-template otError Tlv::FindUintTlv<uint8_t>(const Message &aMessage, uint8_t aType, uint8_t &aValue);
+template Error Tlv::FindUintTlv<uint8_t>(const Message &aMessage, uint8_t aType, uint8_t &aValue);
-template otError Tlv::FindUintTlv<uint16_t>(const Message &aMessage, uint8_t aType, uint16_t &aValue);
+template Error Tlv::FindUintTlv<uint16_t>(const Message &aMessage, uint8_t aType, uint16_t &aValue);
-template otError Tlv::FindUintTlv<uint32_t>(const Message &aMessage, uint8_t aType, uint32_t &aValue);
+template Error Tlv::FindUintTlv<uint32_t>(const Message &aMessage, uint8_t aType, uint32_t &aValue);
 
-otError Tlv::FindTlv(const Message &aMessage, uint8_t aType, void *aValue, uint8_t aLength)
+Error Tlv::FindTlv(const Message &aMessage, uint8_t aType, void *aValue, uint8_t aLength)
 {
-    otError  error;
+    Error    error;
     uint16_t offset;
     uint16_t length;
 
     SuccessOrExit(error = FindTlvValueOffset(aMessage, aType, offset, length));
-    VerifyOrExit(length >= aLength, error = OT_ERROR_PARSE);
+    VerifyOrExit(length >= aLength, error = kErrorParse);
     aMessage.ReadBytes(offset, aValue, aLength);
 
 exit:
     return error;
 }
 
-template <typename UintType> otError Tlv::AppendUintTlv(Message &aMessage, uint8_t aType, UintType aValue)
+template <typename UintType> Error Tlv::AppendUintTlv(Message &aMessage, uint8_t aType, UintType aValue)
 {
     UintType value = Encoding::BigEndian::HostSwap<UintType>(aValue);
 
@@ -238,14 +238,14 @@ template <typename UintType> otError Tlv::AppendUintTlv(Message &aMessage, uint8
 }
 
 // Explicit instantiations of `AppendUintTlv<>()`
-template otError Tlv::AppendUintTlv<uint8_t>(Message &aMessage, uint8_t aType, uint8_t aValue);
+template Error Tlv::AppendUintTlv<uint8_t>(Message &aMessage, uint8_t aType, uint8_t aValue);
-template otError Tlv::AppendUintTlv<uint16_t>(Message &aMessage, uint8_t aType, uint16_t aValue);
+template Error Tlv::AppendUintTlv<uint16_t>(Message &aMessage, uint8_t aType, uint16_t aValue);
-template otError Tlv::AppendUintTlv<uint32_t>(Message &aMessage, uint8_t aType, uint32_t aValue);
+template Error Tlv::AppendUintTlv<uint32_t>(Message &aMessage, uint8_t aType, uint32_t aValue);
 
-otError Tlv::AppendTlv(Message &aMessage, uint8_t aType, const void *aValue, uint8_t aLength)
+Error Tlv::AppendTlv(Message &aMessage, uint8_t aType, const void *aValue, uint8_t aLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    Tlv     tlv;
+    Tlv   tlv;
 
     OT_ASSERT(aLength <= Tlv::kBaseTlvMaxLength);
 

src/core/common/tlvs.hpp

@@ -36,11 +36,11 @@
 
 #include "openthread-core-config.h"
 
-#include <openthread/error.h>
 #include <openthread/thread.h>
 #include <openthread/platform/toolchain.h>
 
 #include "common/encoding.hpp"
+#include "common/error.hpp"
 #include "common/type_traits.hpp"
 
 namespace ot {
@@ -171,11 +171,11 @@ public:
      *
      * @param[in]  aMessage      A reference to the message to append to.
      *
-     * @retval OT_ERROR_NONE     Successfully appended the TLV to the message.
+     * @retval kErrorNone     Successfully appended the TLV to the message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs   Insufficient available buffers to grow the message.
      *
      */
-    otError AppendTo(Message &aMessage) const;
+    Error AppendTo(Message &aMessage) const;
 
     /**
      * This static method reads a TLV in a message at a given offset expecting a minimum length for the value.
@@ -185,11 +185,11 @@ public:
      * @param[out]  aValue      A buffer to output the TLV's value, must contain (at least) @p aMinLength bytes.
      * @param[in]   aMinLength  The minimum expected length of TLV and number of bytes to copy into @p aValue buffer.
      *
-     * @retval OT_ERROR_NONE        Successfully read the TLV and copied @p aMinLength into @p aValue.
+     * @retval kErrorNone        Successfully read the TLV and copied @p aMinLength into @p aValue.
-     * @retval OT_ERROR_PARSE       The TLV was not well-formed and could not be parsed.
+     * @retval kErrorParse       The TLV was not well-formed and could not be parsed.
      *
      */
-    static otError ReadTlv(const Message &aMessage, uint16_t aOffset, void *aValue, uint8_t aMinLength);
+    static Error ReadTlv(const Message &aMessage, uint16_t aOffset, void *aValue, uint8_t aMinLength);
 
     /**
      * This static method reads a simple TLV with a single non-integral value in a message at a given offset.
@@ -200,12 +200,12 @@ public:
      * @param[in]   aOffset         The offset into the message pointing to the start of the TLV.
      * @param[out]  aValue          A reference to the value object to output the read value.
      *
-     * @retval OT_ERROR_NONE        Successfully read the TLV and updated the @p aValue.
+     * @retval kErrorNone        Successfully read the TLV and updated the @p aValue.
-     * @retval OT_ERROR_PARSE       The TLV was not well-formed and could not be parsed.
+     * @retval kErrorParse       The TLV was not well-formed and could not be parsed.
      *
      */
     template <typename SimpleTlvType>
-    static otError Read(const Message &aMessage, uint16_t aOffset, typename SimpleTlvType::ValueType &aValue)
+    static Error Read(const Message &aMessage, uint16_t aOffset, typename SimpleTlvType::ValueType &aValue)
     {
         return ReadTlv(aMessage, aOffset, &aValue, sizeof(aValue));
     }
@@ -219,12 +219,12 @@ public:
      * @param[in]   aOffset         The offset into the message pointing to the start of the TLV.
      * @param[out]  aValue          A reference to an unsigned int to output the read value.
      *
-     * @retval OT_ERROR_NONE        Successfully read the TLV and updated the @p aValue.
+     * @retval kErrorNone        Successfully read the TLV and updated the @p aValue.
-     * @retval OT_ERROR_PARSE       The TLV was not well-formed and could not be parsed.
+     * @retval kErrorParse       The TLV was not well-formed and could not be parsed.
      *
      */
     template <typename UintTlvType>
-    static otError Read(const Message &aMessage, uint16_t aOffset, typename UintTlvType::UintValueType &aValue)
+    static Error Read(const Message &aMessage, uint16_t aOffset, typename UintTlvType::UintValueType &aValue)
     {
         return ReadUintTlv(aMessage, aOffset, aValue);
     }
@@ -239,11 +239,11 @@ public:
      * @param[in]   aMaxSize    Maximum number of bytes to read.
      * @param[out]  aTlv        A reference to the TLV that will be copied to.
      *
-     * @retval OT_ERROR_NONE       Successfully copied the TLV.
+     * @retval kErrorNone       Successfully copied the TLV.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
      *
      */
-    static otError FindTlv(const Message &aMessage, uint8_t aType, uint16_t aMaxSize, Tlv &aTlv);
+    static Error FindTlv(const Message &aMessage, uint8_t aType, uint16_t aMaxSize, Tlv &aTlv);
 
     /**
      * This static method searches for and reads a requested TLV out of a given message.
@@ -255,11 +255,11 @@ public:
      * @param[in]   aMessage    A reference to the message.
      * @param[out]  aTlv        A reference to the TLV that will be copied to.
      *
-     * @retval OT_ERROR_NONE       Successfully copied the TLV.
+     * @retval kErrorNone       Successfully copied the TLV.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
      *
      */
-    template <typename TlvType> static otError FindTlv(const Message &aMessage, TlvType &aTlv)
+    template <typename TlvType> static Error FindTlv(const Message &aMessage, TlvType &aTlv)
     {
         return FindTlv(aMessage, TlvType::kType, sizeof(TlvType), aTlv);
     }
@@ -273,11 +273,11 @@ public:
      * @param[in]   aType       The Type value to search for.
      * @param[out]  aOffset     A reference to the offset of the TLV.
      *
-     * @retval OT_ERROR_NONE       Successfully copied the TLV.
+     * @retval kErrorNone       Successfully copied the TLV.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
      *
      */
-    static otError FindTlvOffset(const Message &aMessage, uint8_t aType, uint16_t &aOffset);
+    static Error FindTlvOffset(const Message &aMessage, uint8_t aType, uint16_t &aOffset);
 
     /**
      * This static method finds the offset and length of a given TLV type.
@@ -289,21 +289,18 @@ public:
      * @param[out]  aValueOffset  The offset where the value starts.
      * @param[out]  aLength       The length of the value.
      *
-     * @retval OT_ERROR_NONE       Successfully found the TLV.
+     * @retval kErrorNone       Successfully found the TLV.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
      *
      */
-    static otError FindTlvValueOffset(const Message &aMessage,
+    static Error FindTlvValueOffset(const Message &aMessage, uint8_t aType, uint16_t &aValueOffset, uint16_t &aLength);
-                                      uint8_t        aType,
-                                      uint16_t &     aValueOffset,
-                                      uint16_t &     aLength);
 
     /**
      * This static method searches for a TLV with a given type in a message, ensures its length is same or larger than
      * an expected minimum value, and then reads its value into a given buffer.
      *
      * If the TLV length is smaller than the minimum length @p aLength, the TLV is considered invalid. In this case,
-     * this method returns `OT_ERROR_PARSE` and the @p aValue buffer is not updated.
+     * this method returns `kErrorParse` and the @p aValue buffer is not updated.
      *
      * If the TLV length is larger than @p aLength, the TLV is considered valid, but only the first @p aLength bytes
      * of the value are read and copied into the @p aValue buffer.
@@ -315,12 +312,12 @@ public:
      * @param[out]   aValue      A buffer to output the value (must contain at least @p aLength bytes).
      * @param[in]    aLength     The expected (minimum) length of the TLV value.
      *
-     * @retval OT_ERROR_NONE       The TLV was found and read successfully. @p aValue is updated.
+     * @retval kErrorNone       The TLV was found and read successfully. @p aValue is updated.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
-     * @retval OT_ERROR_PARSE      TLV was found but it was not well-formed and could not be parsed.
+     * @retval kErrorParse      TLV was found but it was not well-formed and could not be parsed.
      *
      */
-    template <typename TlvType> static otError Find(const Message &aMessage, void *aValue, uint8_t aLength)
+    template <typename TlvType> static Error Find(const Message &aMessage, void *aValue, uint8_t aLength)
     {
         return FindTlv(aMessage, TlvType::kType, aValue, aLength);
     }
@@ -330,7 +327,7 @@ public:
      * same or larger than the expected `ValueType` object size, and then reads its value into a value object reference.
      *
      * If the TLV length is smaller than the size of @p aValue, the TLV is considered invalid. In this case, this
-     * method returns `OT_ERROR_PARSE` and the @p aValue is not updated.
+     * method returns `kErrorParse` and the @p aValue is not updated.
      *
      * If the TLV length is larger than the size of @p aValue, the TLV is considered valid, but the size of
      * `ValueType` bytes are read and copied into the @p aValue.
@@ -341,13 +338,13 @@ public:
      * @param[in]    aType           The TLV type to search for.
      * @param[out]   aValue          A reference to the value object to output the read value.
      *
-     * @retval OT_ERROR_NONE         The TLV was found and read successfully. @p aValue is updated.
+     * @retval kErrorNone         The TLV was found and read successfully. @p aValue is updated.
-     * @retval OT_ERROR_NOT_FOUND    Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound     Could not find the TLV with Type @p aType.
-     * @retval OT_ERROR_PARSE        TLV was found but it was not well-formed and could not be parsed.
+     * @retval kErrorParse        TLV was found but it was not well-formed and could not be parsed.
      *
      */
     template <typename SimpleTlvType>
-    static otError Find(const Message &aMessage, typename SimpleTlvType::ValueType &aValue)
+    static Error Find(const Message &aMessage, typename SimpleTlvType::ValueType &aValue)
     {
         return FindTlv(aMessage, SimpleTlvType::kType, &aValue, sizeof(aValue));
     }
@@ -357,20 +354,20 @@ public:
      * into a given `uint` reference variable.
      *
      * If the TLV length is smaller than size of integral value, the TLV is considered invalid. In this case, this
-     * method returns `OT_ERROR_PARSE` and the @p aValue is not updated.
+     * method returns `kErrorParse` and the @p aValue is not updated.
      *
      * @tparam       UintTlvType     The simple TLV type to find (must be a sub-class of `UintTlvInfo`)
      *
      * @param[in]    aMessage        A reference to the message.
      * @param[out]   aValue          A reference to an unsigned int value to output the TLV's value.
      *
-     * @retval OT_ERROR_NONE         The TLV was found and read successfully. @p aValue is updated.
+     * @retval kErrorNone         The TLV was found and read successfully. @p aValue is updated.
-     * @retval OT_ERROR_NOT_FOUND    Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound     Could not find the TLV with Type @p aType.
-     * @retval OT_ERROR_PARSE        TLV was found but it was not well-formed and could not be parsed.
+     * @retval kErrorParse        TLV was found but it was not well-formed and could not be parsed.
      *
      */
     template <typename UintTlvType>
-    static otError Find(const Message &aMessage, typename UintTlvType::UintValueType &aValue)
+    static Error Find(const Message &aMessage, typename UintTlvType::UintValueType &aValue)
     {
         return FindUintTlv(aMessage, UintTlvType::kType, aValue);
     }
@@ -386,11 +383,11 @@ public:
      * @param[in]  aValue        A buffer containing the TLV value.
      * @param[in]  aLength       The value length (in bytes).
      *
-     * @retval OT_ERROR_NONE     Successfully appended the TLV to the message.
+     * @retval kErrorNone     Successfully appended the TLV to the message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs   Insufficient available buffers to grow the message.
      *
      */
-    template <typename TlvType> static otError Append(Message &aMessage, const void *aValue, uint8_t aLength)
+    template <typename TlvType> static Error Append(Message &aMessage, const void *aValue, uint8_t aLength)
     {
         return AppendTlv(aMessage, TlvType::kType, aValue, aLength);
     }
@@ -405,12 +402,12 @@ public:
      * @param[in]  aMessage      A reference to the message to append to.
      * @param[in]  aValue        A reference to the object containing TLV's value.
      *
-     * @retval OT_ERROR_NONE     Successfully appended the TLV to the message.
+     * @retval kErrorNone     Successfully appended the TLV to the message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs   Insufficient available buffers to grow the message.
      *
      */
     template <typename SimpleTlvType>
-    static otError Append(Message &aMessage, const typename SimpleTlvType::ValueType &aValue)
+    static Error Append(Message &aMessage, const typename SimpleTlvType::ValueType &aValue)
     {
         return AppendTlv(aMessage, SimpleTlvType::kType, &aValue, sizeof(aValue));
     }
@@ -425,11 +422,11 @@ public:
      * @param[in]  aMessage      A reference to the message to append to.
      * @param[in]  aValue        An unsigned int value to use as TLV's value.
      *
-     * @retval OT_ERROR_NONE     Successfully appended the TLV to the message.
+     * @retval kErrorNone     Successfully appended the TLV to the message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to grow the message.
+     * @retval kErrorNoBufs   Insufficient available buffers to grow the message.
      *
      */
-    template <typename UintTlvType> static otError Append(Message &aMessage, typename UintTlvType::UintValueType aValue)
+    template <typename UintTlvType> static Error Append(Message &aMessage, typename UintTlvType::UintValueType aValue)
     {
         return AppendUintTlv(aMessage, UintTlvType::kType, aValue);
     }
@@ -454,22 +451,17 @@ private:
      * @param[out]  aSize          A pointer to a variable to output the size (total number of bytes) of the TLV.
      * @param[out]  aIsExtendedTlv A pointer to a boolean variable to output whether the found TLV is extended or not.
      *
-     * @retval OT_ERROR_NONE       Successfully found the TLV.
+     * @retval kErrorNone       Successfully found the TLV.
-     * @retval OT_ERROR_NOT_FOUND  Could not find the TLV with Type @p aType.
+     * @retval kErrorNotFound   Could not find the TLV with Type @p aType.
      *
      */
-    static otError Find(const Message &aMessage,
+    static Error Find(const Message &aMessage, uint8_t aType, uint16_t *aOffset, uint16_t *aSize, bool *aIsExtendedTlv);
-                        uint8_t        aType,
-                        uint16_t *     aOffset,
-                        uint16_t *     aSize,
-                        bool *         aIsExtendedTlv);
 
-    static otError FindTlv(const Message &aMessage, uint8_t aType, void *aValue, uint8_t aLength);
+    static Error FindTlv(const Message &aMessage, uint8_t aType, void *aValue, uint8_t aLength);
-    static otError AppendTlv(Message &aMessage, uint8_t aType, const void *aValue, uint8_t aLength);
+    static Error AppendTlv(Message &aMessage, uint8_t aType, const void *aValue, uint8_t aLength);
-    template <typename UintType>
+    template <typename UintType> static Error ReadUintTlv(const Message &aMessage, uint16_t aOffset, UintType &aValue);
-    static otError ReadUintTlv(const Message &aMessage, uint16_t aOffset, UintType &aValue);
+    template <typename UintType> static Error FindUintTlv(const Message &aMessage, uint8_t aType, UintType &aValue);
-    template <typename UintType> static otError FindUintTlv(const Message &aMessage, uint8_t aType, UintType &aValue);
+    template <typename UintType> static Error AppendUintTlv(Message &aMessage, uint8_t aType, UintType aValue);
-    template <typename UintType> static otError AppendUintTlv(Message &aMessage, uint8_t aType, UintType aValue);
 
     uint8_t mType;
     uint8_t mLength;

src/core/crypto/aes_ccm.hpp

@@ -38,8 +38,7 @@
 
 #include <stdint.h>
 
-#include <openthread/error.h>
+#include "common/error.hpp"
-
 #include "crypto/aes_ecb.hpp"
 #include "mac/mac_types.hpp"
 

src/core/crypto/ecdsa.cpp

@@ -50,7 +50,7 @@ namespace Ecdsa {
 
 #if OPENTHREAD_CONFIG_ECDSA_ENABLE
 
-otError P256::KeyPair::Generate(void)
+Error P256::KeyPair::Generate(void)
 {
     mbedtls_pk_context pk;
     int                ret;
@@ -74,26 +74,26 @@ otError P256::KeyPair::Generate(void)
 exit:
     mbedtls_pk_free(&pk);
 
-    return (ret >= 0) ? OT_ERROR_NONE : MbedTls::MapError(ret);
+    return (ret >= 0) ? kErrorNone : MbedTls::MapError(ret);
 }
 
-otError P256::KeyPair::Parse(void *aContext) const
+Error P256::KeyPair::Parse(void *aContext) const
 {
-    otError             error = OT_ERROR_NONE;
+    Error               error = kErrorNone;
     mbedtls_pk_context *pk    = reinterpret_cast<mbedtls_pk_context *>(aContext);
 
     mbedtls_pk_init(pk);
 
-    VerifyOrExit(mbedtls_pk_setup(pk, mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY)) == 0, error = OT_ERROR_FAILED);
+    VerifyOrExit(mbedtls_pk_setup(pk, mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY)) == 0, error = kErrorFailed);
-    VerifyOrExit(mbedtls_pk_parse_key(pk, mDerBytes, mDerLength, nullptr, 0) == 0, error = OT_ERROR_PARSE);
+    VerifyOrExit(mbedtls_pk_parse_key(pk, mDerBytes, mDerLength, nullptr, 0) == 0, error = kErrorParse);
 
 exit:
     return error;
 }
 
-otError P256::KeyPair::GetPublicKey(PublicKey &aPublicKey) const
+Error P256::KeyPair::GetPublicKey(PublicKey &aPublicKey) const
 {
-    otError              error;
+    Error                error;
     mbedtls_pk_context   pk;
     mbedtls_ecp_keypair *keyPair;
     int                  ret;
@@ -113,9 +113,9 @@ exit:
     return error;
 }
 
-otError P256::KeyPair::Sign(const Sha256::Hash &aHash, Signature &aSignature) const
+Error P256::KeyPair::Sign(const Sha256::Hash &aHash, Signature &aSignature) const
 {
-    otError               error;
+    Error                 error;
     mbedtls_pk_context    pk;
     mbedtls_ecp_keypair * keypair;
     mbedtls_ecdsa_context ecdsa;
@@ -155,9 +155,9 @@ exit:
     return error;
 }
 
-otError P256::PublicKey::Verify(const Sha256::Hash &aHash, const Signature &aSignature) const
+Error P256::PublicKey::Verify(const Sha256::Hash &aHash, const Signature &aSignature) const
 {
-    otError               error = OT_ERROR_NONE;
+    Error                 error = kErrorNone;
     mbedtls_ecdsa_context ecdsa;
     mbedtls_mpi           r;
     mbedtls_mpi           s;
@@ -184,7 +184,7 @@ otError P256::PublicKey::Verify(const Sha256::Hash &aHash, const Signature &aSig
     VerifyOrExit(ret == 0, error = MbedTls::MapError(ret));
 
     ret = mbedtls_ecdsa_verify(&ecdsa.grp, aHash.GetBytes(), Sha256::Hash::kSize, &ecdsa.Q, &r, &s);
-    VerifyOrExit(ret == 0, error = OT_ERROR_SECURITY);
+    VerifyOrExit(ret == 0, error = kErrorSecurity);
 
 exit:
     mbedtls_mpi_free(&s);
@@ -194,14 +194,14 @@ exit:
     return error;
 }
 
-otError Sign(uint8_t *      aOutput,
+Error Sign(uint8_t *      aOutput,
-             uint16_t &     aOutputLength,
+           uint16_t &     aOutputLength,
-             const uint8_t *aInputHash,
+           const uint8_t *aInputHash,
-             uint16_t       aInputHashLength,
+           uint16_t       aInputHashLength,
-             const uint8_t *aPrivateKey,
+           const uint8_t *aPrivateKey,
-             uint16_t       aPrivateKeyLength)
+           uint16_t       aPrivateKeyLength)
 {
-    otError               error = OT_ERROR_NONE;
+    Error                 error = kErrorNone;
     mbedtls_ecdsa_context ctx;
     mbedtls_pk_context    pkCtx;
     mbedtls_ecp_keypair * keypair;
@@ -215,26 +215,26 @@ otError Sign(uint8_t *      aOutput,
 
     // Parse a private key in PEM format.
     VerifyOrExit(mbedtls_pk_parse_key(&pkCtx, aPrivateKey, aPrivateKeyLength, nullptr, 0) == 0,
-                 error = OT_ERROR_INVALID_ARGS);
+                 error = kErrorInvalidArgs);
-    VerifyOrExit(mbedtls_pk_get_type(&pkCtx) == MBEDTLS_PK_ECKEY, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(mbedtls_pk_get_type(&pkCtx) == MBEDTLS_PK_ECKEY, error = kErrorInvalidArgs);
 
     keypair = mbedtls_pk_ec(pkCtx);
     OT_ASSERT(keypair != nullptr);
 
-    VerifyOrExit(mbedtls_ecdsa_from_keypair(&ctx, keypair) == 0, error = OT_ERROR_FAILED);
+    VerifyOrExit(mbedtls_ecdsa_from_keypair(&ctx, keypair) == 0, error = kErrorFailed);
 
     // Sign using ECDSA.
     VerifyOrExit(mbedtls_ecdsa_sign(&ctx.grp, &rMpi, &sMpi, &ctx.d, aInputHash, aInputHashLength,
                                     mbedtls_ctr_drbg_random, Random::Crypto::MbedTlsContextGet()) == 0,
-                 error = OT_ERROR_FAILED);
+                 error = kErrorFailed);
-    VerifyOrExit(mbedtls_mpi_size(&rMpi) + mbedtls_mpi_size(&sMpi) <= aOutputLength, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(mbedtls_mpi_size(&rMpi) + mbedtls_mpi_size(&sMpi) <= aOutputLength, error = kErrorNoBufs);
 
     // Concatenate the two octet sequences in the order R and then S.
-    VerifyOrExit(mbedtls_mpi_write_binary(&rMpi, aOutput, mbedtls_mpi_size(&rMpi)) == 0, error = OT_ERROR_FAILED);
+    VerifyOrExit(mbedtls_mpi_write_binary(&rMpi, aOutput, mbedtls_mpi_size(&rMpi)) == 0, error = kErrorFailed);
     aOutputLength = static_cast<uint16_t>(mbedtls_mpi_size(&rMpi));
 
     VerifyOrExit(mbedtls_mpi_write_binary(&sMpi, aOutput + aOutputLength, mbedtls_mpi_size(&sMpi)) == 0,
-                 error = OT_ERROR_FAILED);
+                 error = kErrorFailed);
     aOutputLength += mbedtls_mpi_size(&sMpi);
 
 exit:

src/core/crypto/ecdsa.hpp

@@ -39,8 +39,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-#include <openthread/error.h>
+#include "common/error.hpp"
-
 #include "crypto/sha256.hpp"
 
 namespace ot {
@@ -146,24 +145,24 @@ public:
         /**
          * This method generates and populates the `KeyPair` with a new public/private keys.
          *
-         * @retval OT_ERROR_NONE         A new key pair was generated successfully.
+         * @retval kErrorNone         A new key pair was generated successfully.
-         * @retval OT_ERROR_NO_BUFS      Failed to allocate buffer for key generation.
+         * @retval kErrorNoBufs       Failed to allocate buffer for key generation.
-         * @retval OT_ERROR_NOT_CAPABLE  Feature not supported.
+         * @retval kErrorNotCapable   Feature not supported.
-         * @retval OT_ERROR_FAILED       Failed to generate key.
+         * @retval kErrorFailed       Failed to generate key.
          *
          */
-        otError Generate(void);
+        Error Generate(void);
 
         /**
          * This method gets the associated public key from the `KeyPair`.
          *
          * @param[out] aPublicKey     A reference to a `PublicKey` to output the value.
          *
-         * @retval OT_ERROR_NONE      Public key was retrieved successfully, and @p aPublicKey is updated.
+         * @retval kErrorNone      Public key was retrieved successfully, and @p aPublicKey is updated.
-         * @retval OT_ERROR_PARSE     The key-pair DER format could not be parsed (invalid format).
+         * @retval kErrorParse     The key-pair DER format could not be parsed (invalid format).
          *
          */
-        otError GetPublicKey(PublicKey &aPublicKey) const;
+        Error GetPublicKey(PublicKey &aPublicKey) const;
 
         /**
          * This method gets the pointer to start of the buffer containing the key-pair info in DER format.
@@ -211,16 +210,16 @@ public:
          * @param[in]  aHash               The SHA-256 hash value of the message to use for signature calculation.
          * @param[out] aSignature          A reference to a `Signature` to output the calculated signature value.
          *
-         * @retval OT_ERROR_NONE           The signature was calculated successfully and @p aSignature was updated.
+         * @retval kErrorNone           The signature was calculated successfully and @p aSignature was updated.
-         * @retval OT_ERROR_PARSE          The key-pair DER format could not be parsed (invalid format).
+         * @retval kErrorParse          The key-pair DER format could not be parsed (invalid format).
-         * @retval OT_ERROR_INVALID_ARGS   The @p aHash is invalid.
+         * @retval kErrorInvalidArgs    The @p aHash is invalid.
-         * @retval OT_ERROR_NO_BUFS        Failed to allocate buffer for signature calculation.
+         * @retval kErrorNoBufs         Failed to allocate buffer for signature calculation.
          *
          */
-        otError Sign(const Sha256::Hash &aHash, Signature &aSignature) const;
+        Error Sign(const Sha256::Hash &aHash, Signature &aSignature) const;
 
     private:
-        otError Parse(void *aContext) const;
+        Error Parse(void *aContext) const;
 
         uint8_t mDerBytes[kMaxDerSize];
         uint8_t mDerLength;
@@ -257,13 +256,13 @@ public:
          * @param[in] aHash                The SHA-256 hash value of a message to use for signature verification.
          * @param[in] aSignature           The signature value to verify.
          *
-         * @retval OT_ERROR_NONE           The signature was verified successfully.
+         * @retval kErrorNone          The signature was verified successfully.
-         * @retval OT_ERROR_SECURITY       The signature is invalid.
+         * @retval kErrorSecurity      The signature is invalid.
-         * @retval OT_ERROR_INVALID_ARGS   The key or has is invalid.
+         * @retval kErrorInvalidArgs   The key or has is invalid.
-         * @retval OT_ERROR_NO_BUFS        Failed to allocate buffer for signature verification
+         * @retval kErrorNoBufs        Failed to allocate buffer for signature verification
          *
          */
-        otError Verify(const Sha256::Hash &aHash, const Signature &aSignature) const;
+        Error Verify(const Sha256::Hash &aHash, const Signature &aSignature) const;
 
     private:
         uint8_t mData[kSize];
@@ -280,18 +279,18 @@ public:
  * @param[in]     aPrivateKey        A private key in PEM format.
  * @param[in]     aPrivateKeyLength  The length of the @p aPrivateKey buffer.
  *
- * @retval  OT_ERROR_NONE         ECDSA sign has been created successfully.
+ * @retval  kErrorNone         ECDSA sign has been created successfully.
- * @retval  OT_ERROR_NO_BUFS      Output buffer is too small.
+ * @retval  kErrorNoBufs       Output buffer is too small.
- * @retval  OT_ERROR_INVALID_ARGS Private key is not valid EC Private Key.
+ * @retval  kErrorInvalidArgs  Private key is not valid EC Private Key.
- * @retval  OT_ERROR_FAILED       Error during signing.
+ * @retval  kErrorFailed       Error during signing.
  *
  */
-otError Sign(uint8_t *      aOutput,
+Error Sign(uint8_t *      aOutput,
-             uint16_t &     aOutputLength,
+           uint16_t &     aOutputLength,
-             const uint8_t *aInputHash,
+           const uint8_t *aInputHash,
-             uint16_t       aInputHashLength,
+           uint16_t       aInputHashLength,
-             const uint8_t *aPrivateKey,
+           const uint8_t *aPrivateKey,
-             uint16_t       aPrivateKeyLength);
+           uint16_t       aPrivateKeyLength);
 
 /**
  * @}

src/core/crypto/mbedtls.cpp

@@ -36,7 +36,6 @@
 #include <mbedtls/ctr_drbg.h>
 #include <mbedtls/debug.h>
 #include <mbedtls/entropy.h>
-#include <mbedtls/error.h>
 #include <mbedtls/platform.h>
 #include <mbedtls/threading.h>
 
@@ -44,6 +43,7 @@
 #include <mbedtls/pem.h>
 #endif
 
+#include "common/error.hpp"
 #include "common/instance.hpp"
 
 namespace ot {
@@ -60,9 +60,9 @@ MbedTls::MbedTls(void)
 #endif // OPENTHREAD_CONFIG_ENABLE_BUILTIN_MBEDTLS_MANAGEMENT
 }
 
-otError MbedTls::MapError(int aMbedTlsError)
+Error MbedTls::MapError(int aMbedTlsError)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     switch (aMbedTlsError)
     {
@@ -102,7 +102,7 @@ otError MbedTls::MapError(int aMbedTlsError)
     case MBEDTLS_ERR_SSL_BAD_INPUT_DATA:
     case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
     case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
-        error = OT_ERROR_INVALID_ARGS;
+        error = kErrorInvalidArgs;
         break;
 
 #if OPENTHREAD_CONFIG_ECDSA_ENABLE
@@ -119,7 +119,7 @@ otError MbedTls::MapError(int aMbedTlsError)
     case MBEDTLS_ERR_SSL_ALLOC_FAILED:
     case MBEDTLS_ERR_SSL_WANT_WRITE:
     case MBEDTLS_ERR_ENTROPY_MAX_SOURCES:
-        error = OT_ERROR_NO_BUFS;
+        error = kErrorNoBufs;
         break;
 
 #ifdef MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
@@ -135,29 +135,29 @@ otError MbedTls::MapError(int aMbedTlsError)
     case MBEDTLS_ERR_SSL_PEER_VERIFY_FAILED:
     case MBEDTLS_ERR_THREADING_BAD_INPUT_DATA:
     case MBEDTLS_ERR_THREADING_MUTEX_ERROR:
-        error = OT_ERROR_SECURITY;
+        error = kErrorSecurity;
         break;
 
 #ifdef MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
     case MBEDTLS_ERR_X509_FATAL_ERROR:
-        error = OT_ERROR_FAILED;
+        error = kErrorFailed;
         break;
 #endif
     case MBEDTLS_ERR_SSL_TIMEOUT:
     case MBEDTLS_ERR_SSL_WANT_READ:
-        error = OT_ERROR_BUSY;
+        error = kErrorBusy;
         break;
 
 #if OPENTHREAD_CONFIG_ECDSA_ENABLE
     case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
-        error = OT_ERROR_NOT_CAPABLE;
+        error = kErrorNotCapable;
         break;
 #endif
 
     default:
         if (aMbedTlsError < 0)
         {
-            error = OT_ERROR_FAILED;
+            error = kErrorFailed;
         }
 
         break;

src/core/crypto/mbedtls.hpp

@@ -38,6 +38,7 @@
 
 #include <openthread/instance.h>
 
+#include "common/error.hpp"
 #include "common/non_copyable.hpp"
 
 namespace ot {
@@ -68,10 +69,10 @@ public:
      *
      * @param[in] aMbedTlsError  The mbed TLS error.
      *
-     * @returns The mapped otError.
+     * @returns The mapped Error.
      *
      */
-    static otError MapError(int aMbedTlsError);
+    static Error MapError(int aMbedTlsError);
 };
 
 /**

src/core/diags/factory_diags.cpp

@@ -58,7 +58,7 @@ otError otPlatDiagProcess(otInstance *aInstance,
     OT_UNUSED_VARIABLE(aOutput);
     OT_UNUSED_VARIABLE(aOutputMaxLen);
 
-    return OT_ERROR_INVALID_COMMAND;
+    return ot::kErrorInvalidCommand;
 }
 
 namespace ot {
@@ -79,15 +79,15 @@ Diags::Diags(Instance &aInstance)
 {
 }
 
-otError Diags::ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    long    value;
+    long  value;
 
-    VerifyOrExit(aArgsLength == 1, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aArgsLength == 1, error = kErrorInvalidArgs);
 
     SuccessOrExit(error = ParseLong(aArgs[0], value));
-    VerifyOrExit(value >= Radio::kChannelMin && value <= Radio::kChannelMax, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(value >= Radio::kChannelMin && value <= Radio::kChannelMax, error = kErrorInvalidArgs);
 
     otPlatDiagChannelSet(static_cast<uint8_t>(value));
 
@@ -96,12 +96,12 @@ exit:
     return error;
 }
 
-otError Diags::ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    long    value;
+    long  value;
 
-    VerifyOrExit(aArgsLength == 1, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aArgsLength == 1, error = kErrorInvalidArgs);
 
     SuccessOrExit(error = ParseLong(aArgs[0], value));
 
@@ -112,7 +112,7 @@ exit:
     return error;
 }
 
-otError Diags::ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
     OT_UNUSED_VARIABLE(aArgsLength);
     OT_UNUSED_VARIABLE(aArgs);
@@ -121,10 +121,10 @@ otError Diags::ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, s
 
     otPlatDiagModeSet(true);
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
-otError Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
     OT_UNUSED_VARIABLE(aArgsLength);
     OT_UNUSED_VARIABLE(aArgs);
@@ -133,7 +133,7 @@ otError Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, si
 
     otPlatDiagModeSet(false);
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 }
 
 extern "C" void otPlatDiagAlarmFired(otInstance *aInstance)
@@ -162,11 +162,11 @@ Diags::Diags(Instance &aInstance)
     mStats.Clear();
 }
 
-otError Diags::ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
 
     if (aArgsLength == 0)
     {
@@ -177,7 +177,7 @@ otError Diags::ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput,
         long value;
 
         SuccessOrExit(error = ParseLong(aArgs[0], value));
-        VerifyOrExit(value >= Radio::kChannelMin && value <= Radio::kChannelMax, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(value >= Radio::kChannelMin && value <= Radio::kChannelMax, error = kErrorInvalidArgs);
 
         mChannel = static_cast<uint8_t>(value);
         IgnoreError(Get<Radio>().Receive(mChannel));
@@ -191,11 +191,11 @@ exit:
     return error;
 }
 
-otError Diags::ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
 
     if (aArgsLength == 0)
     {
@@ -219,12 +219,12 @@ exit:
     return error;
 }
 
-otError Diags::ProcessRepeat(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessRepeat(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
-    VerifyOrExit(aArgsLength > 0, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aArgsLength > 0, error = kErrorInvalidArgs);
 
     if (strcmp(aArgs[0], "stop") == 0)
     {
@@ -236,13 +236,13 @@ otError Diags::ProcessRepeat(uint8_t aArgsLength, char *aArgs[], char *aOutput,
     {
         long value;
 
-        VerifyOrExit(aArgsLength == 2, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(aArgsLength == 2, error = kErrorInvalidArgs);
 
         SuccessOrExit(error = ParseLong(aArgs[0], value));
         mTxPeriod = static_cast<uint32_t>(value);
 
         SuccessOrExit(error = ParseLong(aArgs[1], value));
-        VerifyOrExit(value <= OT_RADIO_FRAME_MAX_SIZE, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(value <= OT_RADIO_FRAME_MAX_SIZE, error = kErrorInvalidArgs);
         mTxLen = static_cast<uint8_t>(value);
 
         mRepeatActive = true;
@@ -257,19 +257,19 @@ exit:
     return error;
 }
 
-otError Diags::ProcessSend(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessSend(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
-    long    value;
+    long  value;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
-    VerifyOrExit(aArgsLength == 2, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aArgsLength == 2, error = kErrorInvalidArgs);
 
     SuccessOrExit(error = ParseLong(aArgs[0], value));
     mTxPackets = static_cast<uint32_t>(value);
 
     SuccessOrExit(error = ParseLong(aArgs[1], value));
-    VerifyOrExit(value <= OT_RADIO_FRAME_MAX_SIZE, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(value <= OT_RADIO_FRAME_MAX_SIZE, error = kErrorInvalidArgs);
     mTxLen = static_cast<uint8_t>(value);
 
     snprintf(aOutput, aOutputMaxLen, "sending %#x packet(s), length %#x\r\nstatus 0x%02x\r\n",
@@ -281,14 +281,14 @@ exit:
     return error;
 }
 
-otError Diags::ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
     OT_UNUSED_VARIABLE(aArgsLength);
     OT_UNUSED_VARIABLE(aArgs);
 
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(!Get<ThreadNetif>().IsUp(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!Get<ThreadNetif>().IsUp(), error = kErrorInvalidState);
 
     otPlatDiagChannelSet(mChannel);
     otPlatDiagTxPowerSet(mTxPower);
@@ -307,11 +307,11 @@ exit:
     return error;
 }
 
-otError Diags::ProcessStats(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessStats(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
 
     if ((aArgsLength == 1) && (strcmp(aArgs[0], "clear") == 0))
     {
@@ -320,7 +320,7 @@ otError Diags::ProcessStats(uint8_t aArgsLength, char *aArgs[], char *aOutput, s
     }
     else
     {
-        VerifyOrExit(aArgsLength == 0, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(aArgsLength == 0, error = kErrorInvalidArgs);
         snprintf(aOutput, aOutputMaxLen,
                  "received packets: %d\r\nsent packets: %d\r\n"
                  "first received packet: rssi=%d, lqi=%d\r\n"
@@ -335,14 +335,14 @@ exit:
     return error;
 }
 
-otError Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
     OT_UNUSED_VARIABLE(aArgsLength);
     OT_UNUSED_VARIABLE(aArgs);
 
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
 
     otPlatAlarmMilliStop(&GetInstance());
     otPlatDiagModeSet(false);
@@ -375,12 +375,12 @@ void Diags::TransmitPacket(void)
     IgnoreError(Get<Radio>().Transmit(*static_cast<Mac::TxFrame *>(mTxPacket)));
 }
 
-otError Diags::ProcessRadio(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessRadio(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_INVALID_ARGS;
+    Error error = kErrorInvalidArgs;
 
-    VerifyOrExit(otPlatDiagModeGet(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(otPlatDiagModeGet(), error = kErrorInvalidState);
-    VerifyOrExit(aArgsLength > 0, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aArgsLength > 0, error = kErrorInvalidArgs);
 
     if (strcmp(aArgs[0], "sleep") == 0)
     {
@@ -401,7 +401,7 @@ otError Diags::ProcessRadio(uint8_t aArgsLength, char *aArgs[], char *aOutput, s
     {
         otRadioState state = Get<Radio>().GetState();
 
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
 
         switch (state)
         {
@@ -454,9 +454,9 @@ void Diags::AlarmFired(void)
     }
 }
 
-void Diags::ReceiveDone(otRadioFrame *aFrame, otError aError)
+void Diags::ReceiveDone(otRadioFrame *aFrame, Error aError)
 {
-    if (aError == OT_ERROR_NONE)
+    if (aError == kErrorNone)
     {
         // for sensitivity test, only record the rssi and lqi for the first and last packet
         if (mStats.mReceivedPackets == 0)
@@ -474,9 +474,9 @@ void Diags::ReceiveDone(otRadioFrame *aFrame, otError aError)
     otPlatDiagRadioReceived(&GetInstance(), aFrame, aError);
 }
 
-void Diags::TransmitDone(otError aError)
+void Diags::TransmitDone(Error aError)
 {
-    if (aError == OT_ERROR_NONE)
+    if (aError == kErrorNone)
     {
         mStats.mSentPackets++;
 
@@ -499,19 +499,19 @@ exit:
 
 #endif // OPENTHREAD_RADIO
 
-void Diags::AppendErrorResult(otError aError, char *aOutput, size_t aOutputMaxLen)
+void Diags::AppendErrorResult(Error aError, char *aOutput, size_t aOutputMaxLen)
 {
-    if (aError != OT_ERROR_NONE)
+    if (aError != kErrorNone)
     {
         snprintf(aOutput, aOutputMaxLen, "failed\r\nstatus %#x\r\n", aError);
     }
 }
 
-otError Diags::ParseLong(char *aString, long &aLong)
+Error Diags::ParseLong(char *aString, long &aLong)
 {
     char *endptr;
     aLong = strtol(aString, &endptr, 0);
-    return (*endptr == '\0') ? OT_ERROR_NONE : OT_ERROR_PARSE;
+    return (*endptr == '\0') ? kErrorNone : kErrorParse;
 }
 
 void Diags::ProcessLine(const char *aString, char *aOutput, size_t aOutputMaxLen)
@@ -522,12 +522,12 @@ void Diags::ProcessLine(const char *aString, char *aOutput, size_t aOutputMaxLen
         kMaxCommandBuffer = OPENTHREAD_CONFIG_DIAG_CMD_LINE_BUFFER_SIZE,
     };
 
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     char    buffer[kMaxCommandBuffer];
     char *  aArgsector[kMaxArgs];
     uint8_t argCount = 0;
 
-    VerifyOrExit(StringLength(aString, kMaxCommandBuffer) < kMaxCommandBuffer, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(StringLength(aString, kMaxCommandBuffer) < kMaxCommandBuffer, error = kErrorNoBufs);
 
     strcpy(buffer, aString);
     error = ot::Utils::CmdLineParser::ParseCmd(buffer, argCount, aArgsector, kMaxArgs);
@@ -536,16 +536,16 @@ exit:
 
     switch (error)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         aOutput[0] = '\0'; // In case there is no output.
         IgnoreError(ProcessCmd(argCount, &aArgsector[0], aOutput, aOutputMaxLen));
         break;
 
-    case OT_ERROR_NO_BUFS:
+    case kErrorNoBufs:
         snprintf(aOutput, aOutputMaxLen, "failed: command string too long\r\n");
         break;
 
-    case OT_ERROR_INVALID_ARGS:
+    case kErrorInvalidArgs:
         snprintf(aOutput, aOutputMaxLen, "failed: command string contains too many arguments\r\n");
         break;
 
@@ -555,9 +555,9 @@ exit:
     }
 }
 
-otError Diags::ProcessCmd(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
+Error Diags::ProcessCmd(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     // This `rcp` command is for debugging and testing only, building only when NDEBUG is not defined
     // so that it will be excluded from release build.
@@ -594,7 +594,7 @@ otError Diags::ProcessCmd(uint8_t aArgsLength, char *aArgs[], char *aOutput, siz
 
 exit:
     // Add more platform specific diagnostics features here.
-    if (error == OT_ERROR_INVALID_COMMAND && aArgsLength > 1)
+    if (error == kErrorInvalidCommand && aArgsLength > 1)
     {
         snprintf(aOutput, aOutputMaxLen, "diag feature '%s' is not supported\r\n", aArgs[0]);
     }

src/core/diags/factory_diags.hpp

@@ -40,6 +40,7 @@
 
 #include <openthread/platform/radio.h>
 
+#include "common/error.hpp"
 #include "common/locator.hpp"
 #include "common/non_copyable.hpp"
 
@@ -77,12 +78,12 @@ public:
      * @param[out]  aOutput        The diagnostics execution result.
      * @param[in]   aOutputMaxLen  The output buffer size.
      *
-     * @retval  OT_ERROR_INVALID_ARGS       The command is supported but invalid arguments provided.
+     * @retval  kErrorInvalidArgs       The command is supported but invalid arguments provided.
-     * @retval  OT_ERROR_NONE               The command is successfully process.
+     * @retval  kErrorNone              The command is successfully process.
-     * @retval  OT_ERROR_NOT_IMPLEMENTED    The command is not supported.
+     * @retval  kErrorNotImplemented    The command is not supported.
      *
      */
-    otError ProcessCmd(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessCmd(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
 
     /**
      * This method indicates whether or not the factory diagnostics mode is enabled.
@@ -103,28 +104,28 @@ public:
      * The radio driver calls this method to notify OpenThread diagnostics module of a received frame.
      *
      * @param[in]  aFrame  A pointer to the received frame or nullptr if the receive operation failed.
-     * @param[in]  aError  OT_ERROR_NONE when successfully received a frame,
+     * @param[in]  aError  kErrorNone when successfully received a frame,
-     *                     OT_ERROR_ABORT when reception was aborted and a frame was not received,
+     *                     kErrorAbort when reception was aborted and a frame was not received,
-     *                     OT_ERROR_NO_BUFS when a frame could not be received due to lack of rx buffer space.
+     *                     kErrorNoBufs when a frame could not be received due to lack of rx buffer space.
      *
      */
-    void ReceiveDone(otRadioFrame *aFrame, otError aError);
+    void ReceiveDone(otRadioFrame *aFrame, Error aError);
 
     /**
      * The radio driver calls this method to notify OpenThread diagnostics module that the transmission has completed.
      *
-     * @param[in]  aError  OT_ERROR_NONE when the frame was transmitted,
+     * @param[in]  aError  kErrorNone when the frame was transmitted,
-     *                     OT_ERROR_CHANNEL_ACCESS_FAILURE tx could not take place due to activity on channel,
+     *                     kErrorChannelAccessFailure tx could not take place due to activity on channel,
-     *                     OT_ERROR_ABORT when transmission was aborted for other reasons.
+     *                     kErrorAbort when transmission was aborted for other reasons.
      *
      */
-    void TransmitDone(otError aError);
+    void TransmitDone(Error aError);
 
 private:
     struct Command
     {
         const char *mName;
-        otError (Diags::*mCommand)(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+        Error (Diags::*mCommand)(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
     };
 
     struct Stats
@@ -139,19 +140,19 @@ private:
         uint8_t  mLastLqi;
     };
 
-    otError ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessChannel(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessPower(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessRadio(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessRadio(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessRepeat(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessRepeat(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessSend(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessSend(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessStart(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessStats(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessStats(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
-    otError ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
+    Error ProcessStop(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
 
     void TransmitPacket(void);
 
-    static void    AppendErrorResult(otError aError, char *aOutput, size_t aOutputMaxLen);
+    static void  AppendErrorResult(Error aError, char *aOutput, size_t aOutputMaxLen);
-    static otError ParseLong(char *aString, long &aLong);
+    static Error ParseLong(char *aString, long &aLong);
 
     static const struct Command sCommands[];
 

src/core/mac/channel_mask.cpp

@@ -44,7 +44,7 @@ uint8_t ChannelMask::GetNumberOfChannels(void) const
     uint8_t num     = 0;
     uint8_t channel = kChannelIteratorFirst;
 
-    while (GetNextChannel(channel) == OT_ERROR_NONE)
+    while (GetNextChannel(channel) == kErrorNone)
     {
         num++;
     }
@@ -52,9 +52,9 @@ uint8_t ChannelMask::GetNumberOfChannels(void) const
     return num;
 }
 
-otError ChannelMask::GetNextChannel(uint8_t &aChannel) const
+Error ChannelMask::GetNextChannel(uint8_t &aChannel) const
 {
-    otError error = OT_ERROR_NOT_FOUND;
+    Error error = kErrorNotFound;
 
     if (aChannel == kChannelIteratorFirst)
     {
@@ -65,7 +65,7 @@ otError ChannelMask::GetNextChannel(uint8_t &aChannel) const
     {
         if (ContainsChannel(aChannel))
         {
-            ExitNow(error = OT_ERROR_NONE);
+            ExitNow(error = kErrorNone);
         }
     }
 
@@ -98,18 +98,18 @@ ChannelMask::InfoString ChannelMask::ToString(void) const
     InfoString string;
     uint8_t    channel  = kChannelIteratorFirst;
     bool       addComma = false;
-    otError    error;
+    Error      error;
 
     IgnoreError(string.Append("{"));
 
     error = GetNextChannel(channel);
 
-    while (error == OT_ERROR_NONE)
+    while (error == kErrorNone)
     {
         uint8_t rangeStart = channel;
         uint8_t rangeEnd   = channel;
 
-        while ((error = GetNextChannel(channel)) == OT_ERROR_NONE)
+        while ((error = GetNextChannel(channel)) == kErrorNone)
         {
             if (channel != rangeEnd + 1)
             {

src/core/mac/channel_mask.hpp

@@ -201,11 +201,11 @@ public:
      *                               On entry it should contain the previous channel or `kChannelIteratorFirst`.
      *                               On exit it contains the next channel.
      *
-     * @retval  OT_ERROR_NONE        Got the next channel, @p aChannel updated successfully.
+     * @retval  kErrorNone       Got the next channel, @p aChannel updated successfully.
-     * @retval  OT_ERROR_NOT_FOUND   No next channel in the channel mask (note: @p aChannel may be changed).
+     * @retval  kErrorNotFound   No next channel in the channel mask (note: @p aChannel may be changed).
      *
      */
-    otError GetNextChannel(uint8_t &aChannel) const;
+    Error GetNextChannel(uint8_t &aChannel) const;
 
     /**
      * This method randomly chooses a channel from the channel mask.

src/core/mac/data_poll_handler.cpp

@@ -47,16 +47,16 @@ DataPollHandler::Callbacks::Callbacks(Instance &aInstance)
 {
 }
 
-inline otError DataPollHandler::Callbacks::PrepareFrameForChild(Mac::TxFrame &aFrame,
+inline Error DataPollHandler::Callbacks::PrepareFrameForChild(Mac::TxFrame &aFrame,
-                                                                FrameContext &aContext,
+                                                              FrameContext &aContext,
-                                                                Child &       aChild)
+                                                              Child &       aChild)
 {
     return Get<IndirectSender>().PrepareFrameForChild(aFrame, aContext, aChild);
 }
 
 inline void DataPollHandler::Callbacks::HandleSentFrameToChild(const Mac::TxFrame &aFrame,
                                                                const FrameContext &aContext,
-                                                               otError             aError,
+                                                               Error               aError,
                                                                Child &             aChild)
 {
     Get<IndirectSender>().HandleSentFrameToChild(aFrame, aContext, aError, aChild);
@@ -183,7 +183,7 @@ Mac::TxFrame *DataPollHandler::HandleFrameRequest(Mac::TxFrames &aTxFrames)
     frame = &aTxFrames.GetTxFrame();
 #endif
 
-    VerifyOrExit(mCallbacks.PrepareFrameForChild(*frame, mFrameContext, *mIndirectTxChild) == OT_ERROR_NONE,
+    VerifyOrExit(mCallbacks.PrepareFrameForChild(*frame, mFrameContext, *mIndirectTxChild) == kErrorNone,
                  frame = nullptr);
 
     if (mIndirectTxChild->GetIndirectTxAttempts() > 0)
@@ -210,7 +210,7 @@ exit:
     return frame;
 }
 
-void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, otError aError)
+void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, Error aError)
 {
     Child *child = mIndirectTxChild;
 
@@ -223,7 +223,7 @@ exit:
     ProcessPendingPolls();
 }
 
-void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, otError aError, Child &aChild)
+void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, Error aError, Child &aChild)
 {
     if (aChild.IsFramePurgePending())
     {
@@ -236,12 +236,12 @@ void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, otError aError
 
     switch (aError)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         aChild.ResetIndirectTxAttempts();
         aChild.SetFrameReplacePending(false);
         break;
 
-    case OT_ERROR_NO_ACK:
+    case kErrorNoAck:
         aChild.IncrementIndirectTxAttempts();
 
         otLogInfoMac("Indirect tx to child %04x failed, attempt %d/%d", aChild.GetRloc16(),
@@ -249,8 +249,8 @@ void DataPollHandler::HandleSentFrame(const Mac::TxFrame &aFrame, otError aError
 
         OT_FALL_THROUGH;
 
-    case OT_ERROR_CHANNEL_ACCESS_FAILURE:
+    case kErrorChannelAccessFailure:
-    case OT_ERROR_ABORT:
+    case kErrorAbort:
 
         if (aChild.IsFrameReplacePending())
         {

src/core/mac/data_poll_handler.hpp

@@ -171,27 +171,27 @@ public:
          * @param[out] aContext  A reference to a `FrameContext` where the context for the new frame would be placed.
          * @param[in]  aChild    The child for which to prepare the frame.
          *
-         * @retval OT_ERROR_NONE   Frame was prepared successfully.
+         * @retval kErrorNone   Frame was prepared successfully.
-         * @retval OT_ERROR_ABORT  Indirect transmission to child should be aborted (no frame for the child).
+         * @retval kErrorAbort  Indirect transmission to child should be aborted (no frame for the child).
          *
          */
-        otError PrepareFrameForChild(Mac::TxFrame &aFrame, FrameContext &aContext, Child &aChild);
+        Error PrepareFrameForChild(Mac::TxFrame &aFrame, FrameContext &aContext, Child &aChild);
 
         /**
          * This callback method notifies the end of indirect frame transmission to a child.
          *
          * @param[in]  aFrame     The transmitted frame.
          * @param[in]  aContext   The context associated with the frame when it was prepared.
-         * @param[in]  aError     OT_ERROR_NONE when the frame was transmitted successfully,
+         * @param[in]  aError     kErrorNone when the frame was transmitted successfully,
-         *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+         *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-         *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+         *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-         *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+         *                        kErrorAbort when transmission was aborted for other reasons.
          * @param[in]  aChild     The child to which the frame was transmitted.
          *
          */
         void HandleSentFrameToChild(const Mac::TxFrame &aFrame,
                                     const FrameContext &aContext,
-                                    otError             aError,
+                                    Error               aError,
                                     Child &             aChild);
 
         /**
@@ -272,9 +272,9 @@ private:
     // Callbacks from MAC
     void          HandleDataPoll(Mac::RxFrame &aFrame);
     Mac::TxFrame *HandleFrameRequest(Mac::TxFrames &aTxFrames);
-    void          HandleSentFrame(const Mac::TxFrame &aFrame, otError aError);
+    void          HandleSentFrame(const Mac::TxFrame &aFrame, Error aError);
 
-    void HandleSentFrame(const Mac::TxFrame &aFrame, otError aError, Child &aChild);
+    void HandleSentFrame(const Mac::TxFrame &aFrame, Error aError, Child &aChild);
     void ProcessPendingPolls(void);
 
     // In the current implementation of `DataPollHandler`, we can have a

src/core/mac/data_poll_sender.cpp

@@ -94,14 +94,14 @@ void DataPollSender::StopPolling(void)
     mEnabled              = false;
 }
 
-otError DataPollSender::SendDataPoll(void)
+Error DataPollSender::SendDataPoll(void)
 {
-    otError error;
+    Error error;
 
-    VerifyOrExit(mEnabled, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mEnabled, error = kErrorInvalidState);
-    VerifyOrExit(!Get<Mac::Mac>().GetRxOnWhenIdle(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!Get<Mac::Mac>().GetRxOnWhenIdle(), error = kErrorInvalidState);
 
-    VerifyOrExit(GetParent().IsStateValidOrRestoring(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(GetParent().IsStateValidOrRestoring(), error = kErrorInvalidState);
 
     mTimer.Stop();
 
@@ -111,23 +111,23 @@ exit:
 
     switch (error)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         otLogDebgMac("Sending data poll");
         ScheduleNextPoll(kUsePreviousPollPeriod);
         break;
 
-    case OT_ERROR_INVALID_STATE:
+    case kErrorInvalidState:
         otLogWarnMac("Data poll tx requested while data polling was not enabled!");
         StopPolling();
         break;
 
-    case OT_ERROR_ALREADY:
+    case kErrorAlready:
         otLogDebgMac("Data poll tx requested when a previous data request still in send queue.");
         ScheduleNextPoll(kUsePreviousPollPeriod);
         break;
 
     default:
-        otLogWarnMac("Unexpected error %s requesting data poll", otThreadErrorToString(error));
+        otLogWarnMac("Unexpected error %s requesting data poll", ErrorToString(error));
         ScheduleNextPoll(kRecalculatePollPeriod);
         break;
     }
@@ -136,15 +136,15 @@ exit:
 }
 
 #if OPENTHREAD_CONFIG_MULTI_RADIO
-otError DataPollSender::GetPollDestinationAddress(Mac::Address &aDest, Mac::RadioType &aRadioType) const
+Error DataPollSender::GetPollDestinationAddress(Mac::Address &aDest, Mac::RadioType &aRadioType) const
 #else
-otError DataPollSender::GetPollDestinationAddress(Mac::Address &aDest) const
+Error DataPollSender::GetPollDestinationAddress(Mac::Address &aDest) const
 #endif
 {
-    otError         error  = OT_ERROR_NONE;
+    Error           error  = kErrorNone;
     const Neighbor &parent = GetParent();
 
-    VerifyOrExit(parent.IsStateValidOrRestoring(), error = OT_ERROR_ABORT);
+    VerifyOrExit(parent.IsStateValidOrRestoring(), error = kErrorAbort);
 
     // Use extended address attaching to a new parent (i.e. parent is the parent candidate).
     if ((Get<Mac::Mac>().GetShortAddress() == Mac::kShortAddrInvalid) ||
@@ -165,13 +165,13 @@ exit:
     return error;
 }
 
-otError DataPollSender::SetExternalPollPeriod(uint32_t aPeriod)
+Error DataPollSender::SetExternalPollPeriod(uint32_t aPeriod)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     if (aPeriod != 0)
     {
-        VerifyOrExit(aPeriod >= OPENTHREAD_CONFIG_MAC_MINIMUM_POLL_PERIOD, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(aPeriod >= OPENTHREAD_CONFIG_MAC_MINIMUM_POLL_PERIOD, error = kErrorInvalidArgs);
 
         // Clipped by the maximal value.
         if (aPeriod > kMaxExternalPeriod)
@@ -206,7 +206,7 @@ uint32_t DataPollSender::GetKeepAlivePollPeriod(void) const
     return period;
 }
 
-void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, otError aError)
+void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, Error aError)
 {
     Mac::Address macDest;
     bool         shouldRecalculatePollPeriod = false;
@@ -228,7 +228,7 @@ void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, otError aError)
 
     switch (aError)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
 
         if (mRemainingFastPolls != 0)
         {
@@ -250,8 +250,8 @@ void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, otError aError)
 
         break;
 
-    case OT_ERROR_CHANNEL_ACCESS_FAILURE:
+    case kErrorChannelAccessFailure:
-    case OT_ERROR_ABORT:
+    case kErrorAbort:
         mRetxMode                   = true;
         shouldRecalculatePollPeriod = true;
         break;
@@ -259,8 +259,8 @@ void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, otError aError)
     default:
         mPollTxFailureCounter++;
 
-        otLogInfoMac("Failed to send data poll, error:%s, retx:%d/%d", otThreadErrorToString(aError),
+        otLogInfoMac("Failed to send data poll, error:%s, retx:%d/%d", ErrorToString(aError), mPollTxFailureCounter,
-                     mPollTxFailureCounter, kMaxPollRetxAttempts);
+                     kMaxPollRetxAttempts);
 
         if (mPollTxFailureCounter < kMaxPollRetxAttempts)
         {

src/core/mac/data_poll_sender.hpp

@@ -92,13 +92,13 @@ public:
     /**
      * This method enqueues a data poll (an IEEE 802.15.4 Data Request) message.
      *
-     * @retval OT_ERROR_NONE           Successfully enqueued a data poll message
+     * @retval kErrorNone          Successfully enqueued a data poll message
-     * @retval OT_ERROR_ALREADY        A data poll message is already enqueued.
+     * @retval kErrorAlready       A data poll message is already enqueued.
-     * @retval OT_ERROR_INVALID_STATE  Device is not in rx-off-when-idle mode.
+     * @retval kErrorInvalidState  Device is not in rx-off-when-idle mode.
-     * @retval OT_ERROR_NO_BUFS        Insufficient message buffers available.
+     * @retval kErrorNoBufs        Insufficient message buffers available.
      *
      */
-    otError SendDataPoll(void);
+    Error SendDataPoll(void);
 
     /**
      * This method sets/clears a user-specified/external data poll period.
@@ -111,16 +111,16 @@ public:
      * value is larger than the child timeout.
      *
      * A non-zero `aPeriod` should be larger than or equal to `OPENTHREAD_CONFIG_MAC_MINIMUM_POLL_PERIOD` (10ms) or
-     * this method returns `OT_ERROR_INVALID_ARGS`. If a non-zero `aPeriod` is larger than maximum value of
+     * this method returns `kErrorInvalidArgs`. If a non-zero `aPeriod` is larger than maximum value of
      * `0x3FFFFFF ((1 << 26) - 1)`, it would be clipped to this value.
      *
      * @param[in]  aPeriod  The data poll period in milliseconds.
      *
-     * @retval OT_ERROR_NONE           Successfully set/cleared user-specified poll period.
+     * @retval kErrorNone           Successfully set/cleared user-specified poll period.
-     * @retval OT_ERROR_INVALID_ARGS   If aPeriod is invalid.
+     * @retval kErrorInvalidArgs    If aPeriod is invalid.
      *
      */
-    otError SetExternalPollPeriod(uint32_t aPeriod);
+    Error SetExternalPollPeriod(uint32_t aPeriod);
 
     /**
      * This method gets the current user-specified/external data poll period.
@@ -137,22 +137,22 @@ public:
      * @param[out] aDest       Reference to a `MAC::Address` to output the poll destination address (on success).
      * @param[out] aRadioType  Reference to a `Mac::RadioType` to output the link type (on success).
      *
-     * @retval OT_ERROR_NONE   @p aDest and @p aRadioType were updated successfully.
+     * @retval kErrorNone   @p aDest and @p aRadioType were updated successfully.
-     * @retval OT_ERROR_ABORT  Abort the data poll transmission (not currently attached to any parent).
+     * @retval kErrorAbort  Abort the data poll transmission (not currently attached to any parent).
      *
      */
-    otError GetPollDestinationAddress(Mac::Address &aDest, Mac::RadioType &aRadioType) const;
+    Error GetPollDestinationAddress(Mac::Address &aDest, Mac::RadioType &aRadioType) const;
 #else
     /**
      * This method gets the destination MAC address for a data poll frame.
      *
      * @param[out] aDest       Reference to a `MAC::Address` to output the poll destination address (on success).
      *
-     * @retval OT_ERROR_NONE   @p aDest was updated successfully.
+     * @retval kErrorNone   @p aDest was updated successfully.
-     * @retval OT_ERROR_ABORT  Abort the data poll transmission (not currently attached to any parent).
+     * @retval kErrorAbort  Abort the data poll transmission (not currently attached to any parent).
      *
      */
-    otError GetPollDestinationAddress(Mac::Address &aDest) const;
+    Error GetPollDestinationAddress(Mac::Address &aDest) const;
 #endif // #if OPENTHREAD_CONFIG_MULTI_RADIO
 
     /**
@@ -166,7 +166,7 @@ public:
      * @param[in] aError     Error status of a data poll message transmission.
      *
      */
-    void HandlePollSent(Mac::TxFrame &aFrame, otError aError);
+    void HandlePollSent(Mac::TxFrame &aFrame, Error aError);
 
     /**
      * This method informs the data poll sender that a data poll timeout happened, i.e., when the ack in response to

src/core/mac/link_raw.cpp

@@ -64,15 +64,15 @@ LinkRaw::LinkRaw(Instance &aInstance)
 {
 }
 
-otError LinkRaw::SetReceiveDone(otLinkRawReceiveDone aCallback)
+Error LinkRaw::SetReceiveDone(otLinkRawReceiveDone aCallback)
 {
-    otError error  = OT_ERROR_NONE;
+    Error error  = kErrorNone;
-    bool    enable = aCallback != nullptr;
+    bool  enable = aCallback != nullptr;
 
     otLogDebgMac("LinkRaw::Enabled(%s)", (enable ? "true" : "false"));
 
 #if OPENTHREAD_MTD || OPENTHREAD_FTD
-    VerifyOrExit(!Get<ThreadNetif>().IsUp(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(!Get<ThreadNetif>().IsUp(), error = kErrorInvalidState);
 
     // In MTD/FTD build, `Mac` has already enabled sub-mac. We ensure to
     // disable/enable MAC layer when link-raw is being enabled/disabled to
@@ -84,7 +84,7 @@ otError LinkRaw::SetReceiveDone(otLinkRawReceiveDone aCallback)
         // When disabling link-raw, make sure there is no ongoing
         // transmit or scan operation. Otherwise Mac will attempt to
         // handle an unexpected "done" callback.
-        VerifyOrExit(!mSubMac.IsTransmittingOrScanning(), error = OT_ERROR_BUSY);
+        VerifyOrExit(!mSubMac.IsTransmittingOrScanning(), error = kErrorBusy);
     }
 
     Get<Mac>().SetEnabled(!enable);
@@ -105,11 +105,11 @@ exit:
     return error;
 }
 
-otError LinkRaw::SetPanId(uint16_t aPanId)
+Error LinkRaw::SetPanId(uint16_t aPanId)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mSubMac.SetPanId(aPanId);
     mPanId = aPanId;
 
@@ -117,44 +117,44 @@ exit:
     return error;
 }
 
-otError LinkRaw::SetChannel(uint8_t aChannel)
+Error LinkRaw::SetChannel(uint8_t aChannel)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mReceiveChannel = aChannel;
 
 exit:
     return error;
 }
 
-otError LinkRaw::SetExtAddress(const ExtAddress &aExtAddress)
+Error LinkRaw::SetExtAddress(const ExtAddress &aExtAddress)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mSubMac.SetExtAddress(aExtAddress);
 
 exit:
     return error;
 }
 
-otError LinkRaw::SetShortAddress(ShortAddress aShortAddress)
+Error LinkRaw::SetShortAddress(ShortAddress aShortAddress)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mSubMac.SetShortAddress(aShortAddress);
 
 exit:
     return error;
 }
 
-otError LinkRaw::Receive(void)
+Error LinkRaw::Receive(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
 
     SuccessOrExit(error = mSubMac.Receive(mReceiveChannel));
 
@@ -162,22 +162,22 @@ exit:
     return error;
 }
 
-void LinkRaw::InvokeReceiveDone(RxFrame *aFrame, otError aError)
+void LinkRaw::InvokeReceiveDone(RxFrame *aFrame, Error aError)
 {
     otLogDebgMac("LinkRaw::ReceiveDone(%d bytes), error:%s", (aFrame != nullptr) ? aFrame->mLength : 0,
-                 otThreadErrorToString(aError));
+                 ErrorToString(aError));
 
-    if (mReceiveDoneCallback && (aError == OT_ERROR_NONE))
+    if (mReceiveDoneCallback && (aError == kErrorNone))
     {
         mReceiveDoneCallback(&GetInstance(), aFrame, aError);
     }
 }
 
-otError LinkRaw::Transmit(otLinkRawTransmitDone aCallback)
+Error LinkRaw::Transmit(otLinkRawTransmitDone aCallback)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
 
     SuccessOrExit(error = mSubMac.Send());
     mTransmitDoneCallback = aCallback;
@@ -186,9 +186,9 @@ exit:
     return error;
 }
 
-void LinkRaw::InvokeTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError)
+void LinkRaw::InvokeTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError)
 {
-    otLogDebgMac("LinkRaw::TransmitDone(%d bytes), error:%s", aFrame.mLength, otThreadErrorToString(aError));
+    otLogDebgMac("LinkRaw::TransmitDone(%d bytes), error:%s", aFrame.mLength, ErrorToString(aError));
 
     if (mTransmitDoneCallback)
     {
@@ -197,11 +197,11 @@ void LinkRaw::InvokeTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aE
     }
 }
 
-otError LinkRaw::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration, otLinkRawEnergyScanDone aCallback)
+Error LinkRaw::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration, otLinkRawEnergyScanDone aCallback)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
 
     SuccessOrExit(error = mSubMac.EnergyScan(aScanChannel, aScanDuration));
     mEnergyScanDoneCallback = aCallback;
@@ -219,26 +219,26 @@ void LinkRaw::InvokeEnergyScanDone(int8_t aEnergyScanMaxRssi)
     }
 }
 
-otError LinkRaw::SetMacKey(uint8_t    aKeyIdMode,
+Error LinkRaw::SetMacKey(uint8_t    aKeyIdMode,
-                           uint8_t    aKeyId,
+                         uint8_t    aKeyId,
-                           const Key &aPrevKey,
+                         const Key &aPrevKey,
-                           const Key &aCurrKey,
+                         const Key &aCurrKey,
-                           const Key &aNextKey)
+                         const Key &aNextKey)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mSubMac.SetMacKey(aKeyIdMode, aKeyId, aPrevKey, aCurrKey, aNextKey);
 
 exit:
     return error;
 }
 
-otError LinkRaw::SetMacFrameCounter(uint32_t aMacFrameCounter)
+Error LinkRaw::SetMacFrameCounter(uint32_t aMacFrameCounter)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
     mSubMac.SetFrameCounter(aMacFrameCounter);
 
 exit:
@@ -251,16 +251,16 @@ exit:
 
 void LinkRaw::RecordFrameTransmitStatus(const TxFrame &aFrame,
                                         const RxFrame *aAckFrame,
-                                        otError        aError,
+                                        Error          aError,
                                         uint8_t        aRetryCount,
                                         bool           aWillRetx)
 {
     OT_UNUSED_VARIABLE(aAckFrame);
     OT_UNUSED_VARIABLE(aWillRetx);
 
-    if (aError != OT_ERROR_NONE)
+    if (aError != kErrorNone)
     {
-        otLogInfoMac("Frame tx failed, error:%s, retries:%d/%d, %s", otThreadErrorToString(aError), aRetryCount,
+        otLogInfoMac("Frame tx failed, error:%s, retries:%d/%d, %s", ErrorToString(aError), aRetryCount,
                      aFrame.GetMaxFrameRetries(), aFrame.ToInfoString().AsCString());
     }
 }

src/core/mac/link_raw.hpp

@@ -80,12 +80,12 @@ public:
      *                        raw link-layer.
      *
      *
-     * @retval OT_ERROR_INVALID_STATE   Thread stack is enabled.
+     * @retval kErrorInvalidState    Thread stack is enabled.
-     * @retval OT_ERROR_FAILED          The radio could not be enabled/disabled.
+     * @retval kErrorFailed          The radio could not be enabled/disabled.
-     * @retval OT_ERROR_NONE            Successfully enabled/disabled raw link.
+     * @retval kErrorNone            Successfully enabled/disabled raw link.
      *
      */
-    otError SetReceiveDone(otLinkRawReceiveDone aCallback);
+    Error SetReceiveDone(otLinkRawReceiveDone aCallback);
 
     /**
      * This method returns the capabilities of the raw link-layer.
@@ -98,22 +98,22 @@ public:
     /**
      * This method starts a (recurring) Receive on the link-layer.
      *
-     * @retval OT_ERROR_NONE             Successfully transitioned to Receive.
+     * @retval kErrorNone            Successfully transitioned to Receive.
-     * @retval OT_ERROR_INVALID_STATE    The radio was disabled or transmitting.
+     * @retval kErrorInvalidState    The radio was disabled or transmitting.
      *
      */
-    otError Receive(void);
+    Error Receive(void);
 
     /**
      * This method invokes the mReceiveDoneCallback, if set.
      *
      * @param[in]  aFrame    A pointer to the received frame or nullptr if the receive operation failed.
-     * @param[in]  aError    OT_ERROR_NONE when successfully received a frame,
+     * @param[in]  aError    kErrorNone when successfully received a frame,
-     *                       OT_ERROR_ABORT when reception was aborted and a frame was not received,
+     *                       kErrorAbort when reception was aborted and a frame was not received,
-     *                       OT_ERROR_NO_BUFS when a frame could not be received due to lack of rx buffer space.
+     *                       kErrorNoBufs when a frame could not be received due to lack of rx buffer space.
      *
      */
-    void InvokeReceiveDone(RxFrame *aFrame, otError aError);
+    void InvokeReceiveDone(RxFrame *aFrame, Error aError);
 
     /**
      * This method gets the radio transmit frame.
@@ -126,28 +126,28 @@ public:
     /**
      * This method starts a (single) Transmit on the link-layer.
      *
-     * @note The callback @p aCallback will not be called if this call does not return OT_ERROR_NONE.
+     * @note The callback @p aCallback will not be called if this call does not return kErrorNone.
      *
      * @param[in]  aCallback            A pointer to a function called on completion of the transmission.
      *
-     * @retval OT_ERROR_NONE            Successfully transitioned to Transmit.
+     * @retval kErrorNone           Successfully transitioned to Transmit.
-     * @retval OT_ERROR_INVALID_STATE   The radio was not in the Receive state.
+     * @retval kErrorInvalidState   The radio was not in the Receive state.
      *
      */
-    otError Transmit(otLinkRawTransmitDone aCallback);
+    Error Transmit(otLinkRawTransmitDone aCallback);
 
     /**
      * This method invokes the mTransmitDoneCallback, if set.
      *
      * @param[in]  aFrame     The transmitted frame.
      * @param[in]  aAckFrame  A pointer to the ACK frame, nullptr if no ACK was received.
-     * @param[in]  aError     OT_ERROR_NONE when the frame was transmitted,
+     * @param[in]  aError     kErrorNone when the frame was transmitted,
-     *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+     *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-     *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+     *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-     *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+     *                        kErrorAbort when transmission was aborted for other reasons.
      *
      */
-    void InvokeTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError);
+    void InvokeTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError);
 
     /**
      * This method starts a (single) Energy Scan on the link-layer.
@@ -156,12 +156,12 @@ public:
      * @param[in]  aScanDuration    The duration, in milliseconds, for the channel to be scanned.
      * @param[in]  aCallback        A pointer to a function called on completion of a scanned channel.
      *
-     * @retval OT_ERROR_NONE             Successfully started scanning the channel.
+     * @retval kErrorNone            Successfully started scanning the channel.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The radio doesn't support energy scanning.
+     * @retval kErrorNotImplemented  The radio doesn't support energy scanning.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration, otLinkRawEnergyScanDone aCallback);
+    Error EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration, otLinkRawEnergyScanDone aCallback);
 
     /**
      * This method invokes the mEnergyScanDoneCallback, if set.
@@ -184,11 +184,11 @@ public:
      *
      * @param[in]   aShortAddress   The short address.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError SetShortAddress(ShortAddress aShortAddress);
+    Error SetShortAddress(ShortAddress aShortAddress);
 
     /**
      * This function returns PANID.
@@ -203,11 +203,11 @@ public:
      *
      * @param[in]   aPanId          The PANID.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError SetPanId(PanId aPanId);
+    Error SetPanId(PanId aPanId);
 
     /**
      * This method gets the current receiving channel.
@@ -223,7 +223,7 @@ public:
      * @param[in]  aChannel     The channel to use for receiving.
      *
      */
-    otError SetChannel(uint8_t aChannel);
+    Error SetChannel(uint8_t aChannel);
 
     /**
      * This function returns the extended address.
@@ -238,11 +238,11 @@ public:
      *
      * @param[in]   aExtAddress     The extended address.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError SetExtAddress(const ExtAddress &aExtAddress);
+    Error SetExtAddress(const ExtAddress &aExtAddress);
 
     /**
      * This method updates MAC keys and key index.
@@ -253,26 +253,22 @@ public:
      * @param[in]   aCurrKey          The current MAC key.
      * @param[in]   aNextKey          The next MAC key.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError SetMacKey(uint8_t    aKeyIdMode,
+    Error SetMacKey(uint8_t aKeyIdMode, uint8_t aKeyId, const Key &aPrevKey, const Key &aCurrKey, const Key &aNextKey);
-                      uint8_t    aKeyId,
-                      const Key &aPrevKey,
-                      const Key &aCurrKey,
-                      const Key &aNextKey);
 
     /**
      * This method sets the current MAC frame counter value.
      *
      * @param[in] aMacFrameCounter  The MAC frame counter value.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
-    otError SetMacFrameCounter(uint32_t aMacFrameCounter);
+    Error SetMacFrameCounter(uint32_t aMacFrameCounter);
 
     /**
      * This method records the status of a frame transmission attempt and is mainly used for logging failures.
@@ -282,10 +278,10 @@ public:
      *
      * @param[in] aFrame      The transmitted frame.
      * @param[in] aAckFrame   A pointer to the ACK frame, or nullptr if no ACK was received.
-     * @param[in] aError      OT_ERROR_NONE when the frame was transmitted successfully,
+     * @param[in] aError      kErrorNone when the frame was transmitted successfully,
-     *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+     *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-     *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+     *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-     *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+     *                        kErrorAbort when transmission was aborted for other reasons.
      * @param[in] aRetryCount Indicates number of transmission retries for this frame.
      * @param[in] aWillRetx   Indicates whether frame will be retransmitted or not. This is applicable only
      *                        when there was an error in transmission (i.e., `aError` is not NONE).
@@ -294,11 +290,11 @@ public:
 #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_INFO) && (OPENTHREAD_CONFIG_LOG_MAC == 1)
     void RecordFrameTransmitStatus(const TxFrame &aFrame,
                                    const RxFrame *aAckFrame,
-                                   otError        aError,
+                                   Error          aError,
                                    uint8_t        aRetryCount,
                                    bool           aWillRetx);
 #else
-    void    RecordFrameTransmitStatus(const TxFrame &, const RxFrame *, otError, uint8_t, bool) {}
+    void    RecordFrameTransmitStatus(const TxFrame &, const RxFrame *, Error, uint8_t, bool) {}
 #endif
 
 private:

src/core/mac/mac.cpp

@@ -124,7 +124,7 @@ Mac::Mac(Instance &aInstance)
     , mKeyIdMode2FrameCounter(0)
     , mCcaSampleCount(0)
 #if OPENTHREAD_CONFIG_MULTI_RADIO
-    , mTxError(OT_ERROR_NONE)
+    , mTxError(kErrorNone)
 #endif
 {
     ExtAddress randomExtAddress;
@@ -149,12 +149,12 @@ Mac::Mac(Instance &aInstance)
     SetShortAddress(GetShortAddress());
 }
 
-otError Mac::ActiveScan(uint32_t aScanChannels, uint16_t aScanDuration, ActiveScanHandler aHandler, void *aContext)
+Error Mac::ActiveScan(uint32_t aScanChannels, uint16_t aScanDuration, ActiveScanHandler aHandler, void *aContext)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
-    VerifyOrExit(!IsActiveScanInProgress() && !IsEnergyScanInProgress(), error = OT_ERROR_BUSY);
+    VerifyOrExit(!IsActiveScanInProgress() && !IsEnergyScanInProgress(), error = kErrorBusy);
 
     mActiveScanHandler  = aHandler;
     mScanHandlerContext = aContext;
@@ -170,12 +170,12 @@ exit:
     return error;
 }
 
-otError Mac::EnergyScan(uint32_t aScanChannels, uint16_t aScanDuration, EnergyScanHandler aHandler, void *aContext)
+Error Mac::EnergyScan(uint32_t aScanChannels, uint16_t aScanDuration, EnergyScanHandler aHandler, void *aContext)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
-    VerifyOrExit(!IsActiveScanInProgress() && !IsEnergyScanInProgress(), error = OT_ERROR_BUSY);
+    VerifyOrExit(!IsActiveScanInProgress() && !IsEnergyScanInProgress(), error = kErrorBusy);
 
     mEnergyScanHandler  = aHandler;
     mScanHandlerContext = aContext;
@@ -231,9 +231,9 @@ bool Mac::IsInTransmitState(void) const
     return retval;
 }
 
-otError Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, ActiveScanResult &aResult)
+Error Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, ActiveScanResult &aResult)
 {
-    otError              error = OT_ERROR_NONE;
+    Error                error = kErrorNone;
     Address              address;
     const Beacon *       beacon        = nullptr;
     const BeaconPayload *beaconPayload = nullptr;
@@ -241,14 +241,14 @@ otError Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, Active
 
     memset(&aResult, 0, sizeof(ActiveScanResult));
 
-    VerifyOrExit(aBeaconFrame != nullptr, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aBeaconFrame != nullptr, error = kErrorInvalidArgs);
 
-    VerifyOrExit(aBeaconFrame->GetType() == Frame::kFcfFrameBeacon, error = OT_ERROR_PARSE);
+    VerifyOrExit(aBeaconFrame->GetType() == Frame::kFcfFrameBeacon, error = kErrorParse);
     SuccessOrExit(error = aBeaconFrame->GetSrcAddr(address));
-    VerifyOrExit(address.IsExtended(), error = OT_ERROR_PARSE);
+    VerifyOrExit(address.IsExtended(), error = kErrorParse);
     aResult.mExtAddress = address.GetExtended();
 
-    if (OT_ERROR_NONE != aBeaconFrame->GetSrcPanId(aResult.mPanId))
+    if (kErrorNone != aBeaconFrame->GetSrcPanId(aResult.mPanId))
     {
         IgnoreError(aBeaconFrame->GetDstPanId(aResult.mPanId));
     }
@@ -268,7 +268,7 @@ otError Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, Active
         aResult.mIsJoinable = beaconPayload->IsJoiningPermitted();
         aResult.mIsNative   = beaconPayload->IsNative();
         IgnoreError(static_cast<NetworkName &>(aResult.mNetworkName).Set(beaconPayload->GetNetworkName()));
-        VerifyOrExit(IsValidUtf8String(aResult.mNetworkName.m8), error = OT_ERROR_PARSE);
+        VerifyOrExit(IsValidUtf8String(aResult.mNetworkName.m8), error = kErrorParse);
         aResult.mExtendedPanId = beaconPayload->GetExtendedPanId();
     }
 
@@ -278,11 +278,11 @@ exit:
     return error;
 }
 
-otError Mac::UpdateScanChannel(void)
+Error Mac::UpdateScanChannel(void)
 {
-    otError error;
+    Error error;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_ABORT);
+    VerifyOrExit(IsEnabled(), error = kErrorAbort);
 
     error = mScanChannelMask.GetNextChannel(mScanChannel);
 
@@ -292,7 +292,7 @@ exit:
 
 void Mac::PerformActiveScan(void)
 {
-    if (UpdateScanChannel() == OT_ERROR_NONE)
+    if (UpdateScanChannel() == kErrorNone)
     {
         // If there are more channels to scan, send the beacon request.
         BeginTransmit();
@@ -328,7 +328,7 @@ exit:
 
 void Mac::PerformEnergyScan(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     SuccessOrExit(error = UpdateScanChannel());
 
@@ -348,7 +348,7 @@ void Mac::PerformEnergyScan(void)
 
 exit:
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         FinishOperation();
 
@@ -420,11 +420,11 @@ exit:
     return;
 }
 
-otError Mac::SetPanChannel(uint8_t aChannel)
+Error Mac::SetPanChannel(uint8_t aChannel)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(mSupportedChannelMask.ContainsChannel(aChannel), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(mSupportedChannelMask.ContainsChannel(aChannel), error = kErrorInvalidArgs);
 
     SuccessOrExit(Get<Notifier>().Update(mPanChannel, aChannel, kEventThreadChannelChanged));
 
@@ -440,11 +440,11 @@ exit:
     return error;
 }
 
-otError Mac::SetTemporaryChannel(uint8_t aChannel)
+Error Mac::SetTemporaryChannel(uint8_t aChannel)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(mSupportedChannelMask.ContainsChannel(aChannel), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(mSupportedChannelMask.ContainsChannel(aChannel), error = kErrorInvalidArgs);
 
     mUsingTemporaryChannel = true;
     mRadioChannel          = aChannel;
@@ -473,7 +473,7 @@ void Mac::SetSupportedChannelMask(const ChannelMask &aMask)
     IgnoreError(Get<Notifier>().Update(mSupportedChannelMask, newMask, kEventSupportedChannelMaskChanged));
 }
 
-otError Mac::SetNetworkName(const char *aNameString)
+Error Mac::SetNetworkName(const char *aNameString)
 {
     // When setting Network Name from a string, we treat it as `NameData`
     // with `kMaxSize + 1` chars. `NetworkName::Set(data)` will look
@@ -481,12 +481,12 @@ otError Mac::SetNetworkName(const char *aNameString)
     // the name's length and ensure that the name fits in `kMaxSize`
     // chars. The `+ 1` ensures that a `aNameString` with length
     // longer than `kMaxSize` is correctly rejected (returning error
-    // `OT_ERROR_INVALID_ARGS`).
+    // `kErrorInvalidArgs`).
 
-    otError  error;
+    Error    error;
     NameData data(aNameString, NetworkName::kMaxSize + 1);
 
-    VerifyOrExit(IsValidUtf8String(aNameString), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(IsValidUtf8String(aNameString), error = kErrorInvalidArgs);
 
     error = SetNetworkName(data);
 
@@ -494,14 +494,14 @@ exit:
     return error;
 }
 
-otError Mac::SetNetworkName(const NameData &aNameData)
+Error Mac::SetNetworkName(const NameData &aNameData)
 {
-    otError error = mNetworkName.Set(aNameData);
+    Error error = mNetworkName.Set(aNameData);
 
-    if (error == OT_ERROR_ALREADY)
+    if (error == kErrorAlready)
     {
         Get<Notifier>().SignalIfFirst(kEventThreadNetworkNameChanged);
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
         ExitNow();
     }
 
@@ -513,7 +513,7 @@ exit:
 }
 
 #if (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
-otError Mac::SetDomainName(const char *aNameString)
+Error Mac::SetDomainName(const char *aNameString)
 {
     // When setting Domain Name from a string, we treat it as `NameData`
     // with `kMaxSize + 1` chars. `DomainName::Set(data)` will look
@@ -521,12 +521,12 @@ otError Mac::SetDomainName(const char *aNameString)
     // the name's length and ensure that the name fits in `kMaxSize`
     // chars. The `+ 1` ensures that a `aNameString` with length
     // longer than `kMaxSize` is correctly rejected (returning error
-    // `OT_ERROR_INVALID_ARGS`).
+    // `kErrorInvalidArgs`).
 
-    otError  error;
+    Error    error;
     NameData data(aNameString, DomainName::kMaxSize + 1);
 
-    VerifyOrExit(IsValidUtf8String(aNameString), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(IsValidUtf8String(aNameString), error = kErrorInvalidArgs);
 
     error = SetDomainName(data);
 
@@ -534,13 +534,13 @@ exit:
     return error;
 }
 
-otError Mac::SetDomainName(const NameData &aNameData)
+Error Mac::SetDomainName(const NameData &aNameData)
 {
-    otError error = mDomainName.Set(aNameData);
+    Error error = mDomainName.Set(aNameData);
 
-    if (error == OT_ERROR_ALREADY)
+    if (error == kErrorAlready)
     {
-        error = OT_ERROR_NONE;
+        error = kErrorNone;
     }
 
     return error;
@@ -599,14 +599,13 @@ exit:
 #endif
 #endif // OPENTHREAD_FTD
 
-otError Mac::RequestOutOfBandFrameTransmission(otRadioFrame *aOobFrame)
+Error Mac::RequestOutOfBandFrameTransmission(otRadioFrame *aOobFrame)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(aOobFrame != nullptr, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aOobFrame != nullptr, error = kErrorInvalidArgs);
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
-    VerifyOrExit(!mPendingTransmitOobFrame && (mOperation != kOperationTransmitOutOfBandFrame),
+    VerifyOrExit(!mPendingTransmitOobFrame && (mOperation != kOperationTransmitOutOfBandFrame), error = kErrorAlready);
-                 error = OT_ERROR_ALREADY);
 
     mOobFrame = static_cast<TxFrame *>(aOobFrame);
 
@@ -616,12 +615,12 @@ exit:
     return error;
 }
 
-otError Mac::RequestDataPollTransmission(void)
+Error Mac::RequestDataPollTransmission(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
-    VerifyOrExit(!mPendingTransmitPoll && (mOperation != kOperationTransmitPoll), error = OT_ERROR_ALREADY);
+    VerifyOrExit(!mPendingTransmitPoll && (mOperation != kOperationTransmitPoll), error = kErrorAlready);
 
     // We ensure data frame and data poll tx requests are handled in the
     // order they are requested. So if we have a pending direct data frame
@@ -1149,7 +1148,7 @@ void Mac::BeginTransmit(void)
 
 #if OPENTHREAD_CONFIG_MULTI_RADIO
     mTxPendingRadioLinks.Clear();
-    mTxError = OT_ERROR_ABORT;
+    mTxError = kErrorAbort;
 #endif
 
     VerifyOrExit(IsEnabled());
@@ -1300,15 +1299,15 @@ void Mac::BeginTransmit(void)
     mTxPendingRadioLinks = txFrames.GetSelectedRadioTypes();
 
     // If the "required radio type set" is empty,`mTxError` starts as
-    // `OT_ERROR_ABORT`. In this case, successful tx over any radio
+    // `kErrorAbort`. In this case, successful tx over any radio
     // link is sufficient for overall tx to be considered successful.
     // When the "required radio type set" is not empty, `mTxError`
-    // starts as `OT_ERROR_NONE` and we update it if tx over any link
+    // starts as `kErrorNone` and we update it if tx over any link
     // in the required set fails.
 
     if (!txFrames.GetRequiredRadioTypes().IsEmpty())
     {
-        mTxError = OT_ERROR_NONE;
+        mTxError = kErrorNone;
     }
 #endif
 
@@ -1338,7 +1337,7 @@ exit:
 
         frame = &txFrames.GetBroadcastTxFrame();
         frame->SetLength(0);
-        HandleTransmitDone(*frame, nullptr, OT_ERROR_ABORT);
+        HandleTransmitDone(*frame, nullptr, kErrorAbort);
     }
 }
 
@@ -1365,7 +1364,7 @@ void Mac::RecordCcaStatus(bool aCcaSuccess, uint8_t aChannel)
 
 void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
                                     const RxFrame *aAckFrame,
-                                    otError        aError,
+                                    Error          aError,
                                     uint8_t        aRetryCount,
                                     bool           aWillRetx)
 {
@@ -1390,12 +1389,12 @@ void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
 
         switch (aError)
         {
-        case OT_ERROR_NO_ACK:
+        case kErrorNoAck:
             frameTxSuccess = false;
 
             OT_FALL_THROUGH;
 
-        case OT_ERROR_NONE:
+        case kErrorNone:
             neighbor->GetLinkInfo().AddFrameTxStatus(frameTxSuccess);
             break;
 
@@ -1406,7 +1405,7 @@ void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
 
     // Log frame transmission failure.
 
-    if (aError != OT_ERROR_NONE)
+    if (aError != kErrorNone)
     {
         LogFrameTxFailure(aFrame, aError, aRetryCount, aWillRetx);
         otDumpDebgMac("TX ERR", aFrame.GetHeader(), 16);
@@ -1425,7 +1424,7 @@ void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
 
     // Update neighbor's RSSI link info from the received Ack.
 
-    if ((aError == OT_ERROR_NONE) && ackRequested && (aAckFrame != nullptr) && (neighbor != nullptr))
+    if ((aError == kErrorNone) && ackRequested && (aAckFrame != nullptr) && (neighbor != nullptr))
     {
         neighbor->GetLinkInfo().AddRss(aAckFrame->GetRssi());
 #if OPENTHREAD_CONFIG_MLE_LINK_METRICS_ENABLE
@@ -1447,12 +1446,12 @@ void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
 
     mCounters.mTxTotal++;
 
-    if (aError == OT_ERROR_ABORT)
+    if (aError == kErrorAbort)
     {
         mCounters.mTxErrAbort++;
     }
 
-    if (aError == OT_ERROR_CHANNEL_ACCESS_FAILURE)
+    if (aError == kErrorChannelAccessFailure)
     {
         mCounters.mTxErrBusyChannel++;
     }
@@ -1461,7 +1460,7 @@ void Mac::RecordFrameTransmitStatus(const TxFrame &aFrame,
     {
         mCounters.mTxAckRequested++;
 
-        if (aError == OT_ERROR_NONE)
+        if (aError == kErrorNone)
         {
             mCounters.mTxAcked++;
         }
@@ -1484,7 +1483,7 @@ exit:
     return;
 }
 
-void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError)
+void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError)
 {
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE
     if (!aFrame.IsEmpty()
@@ -1522,10 +1521,10 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
 
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
         // Verify Enh-ACK integrity by checking its MIC
-        if ((aError == OT_ERROR_NONE) && (aAckFrame != nullptr) &&
+        if ((aError == kErrorNone) && (aAckFrame != nullptr) &&
-            (ProcessEnhAckSecurity(aFrame, *aAckFrame) != OT_ERROR_NONE))
+            (ProcessEnhAckSecurity(aFrame, *aAckFrame) != kErrorNone))
         {
-            aError = OT_ERROR_NO_ACK;
+            aError = kErrorNoAck;
         }
 #endif
     }
@@ -1544,10 +1543,10 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
             // If the "required radio type set" is empty, successful
             // tx over any radio link is sufficient for overall tx to
             // be considered successful. In this case `mTxError`
-            // starts as `OT_ERROR_ABORT` and we update it only when
+            // starts as `kErrorAbort` and we update it only when
-            // it is not already `OT_ERROR_NONE`.
+            // it is not already `kErrorNone`.
 
-            if (mTxError != OT_ERROR_NONE)
+            if (mTxError != kErrorNone)
             {
                 mTxError = aError;
             }
@@ -1557,13 +1556,13 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
             // When the "required radio type set" is not empty we
             // expect the successful frame tx on all links in this set
             // to consider the overall tx successful. In this case,
-            // `mTxError` starts as `OT_ERROR_NONE` and we update it
+            // `mTxError` starts as `kErrorNone` and we update it
             // if tx over any link in the set fails.
 
-            if (requriedRadios.Contains(radio) && (aError != OT_ERROR_NONE))
+            if (requriedRadios.Contains(radio) && (aError != kErrorNone))
             {
                 otLogDebgMac("Frame tx failed on required radio link %s with error %s", RadioTypeToString(radio),
-                             otThreadErrorToString(aError));
+                             ErrorToString(aError));
 
                 mTxError = aError;
             }
@@ -1597,7 +1596,7 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
     case kOperationTransmitPoll:
         OT_ASSERT(aFrame.IsEmpty() || aFrame.GetAckRequest());
 
-        if ((aError == OT_ERROR_NONE) && (aAckFrame != nullptr))
+        if ((aError == kErrorNone) && (aAckFrame != nullptr))
         {
             bool framePending = aAckFrame->GetFramePending();
 
@@ -1618,7 +1617,7 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
     case kOperationTransmitDataDirect:
         mCounters.mTxData++;
 
-        if (aError != OT_ERROR_NONE)
+        if (aError != kErrorNone)
         {
             mCounters.mTxDirectMaxRetryExpiry++;
         }
@@ -1633,7 +1632,7 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
         FinishOperation();
         Get<MeshForwarder>().HandleSentFrame(aFrame, aError);
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
-        if (aError == OT_ERROR_NONE && Get<Mle::Mle>().GetParent().IsEnhancedKeepAliveSupported() &&
+        if (aError == kErrorNone && Get<Mle::Mle>().GetParent().IsEnhancedKeepAliveSupported() &&
             aFrame.GetSecurityEnabled() && aAckFrame != nullptr)
         {
             Get<DataPollSender>().ProcessFrame(*aAckFrame);
@@ -1657,7 +1656,7 @@ void Mac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError
     case kOperationTransmitDataIndirect:
         mCounters.mTxData++;
 
-        if (aError != OT_ERROR_NONE)
+        if (aError != kErrorNone)
         {
             mCounters.mTxIndirectMaxRetryExpiry++;
         }
@@ -1738,10 +1737,10 @@ void Mac::HandleTimer(void)
     }
 }
 
-otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Neighbor *aNeighbor)
+Error Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Neighbor *aNeighbor)
 {
     KeyManager &      keyManager = Get<KeyManager>();
-    otError           error      = OT_ERROR_SECURITY;
+    Error             error      = kErrorSecurity;
     uint8_t           securityLevel;
     uint8_t           keyIdMode;
     uint32_t          frameCounter;
@@ -1750,7 +1749,7 @@ otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Ne
     const Key *       macKey;
     const ExtAddress *extAddress;
 
-    VerifyOrExit(aFrame.GetSecurityEnabled(), error = OT_ERROR_NONE);
+    VerifyOrExit(aFrame.GetSecurityEnabled(), error = kErrorNone);
 
     IgnoreError(aFrame.GetSecurityLevel(securityLevel));
     VerifyOrExit(securityLevel == Frame::kSecEncMic32);
@@ -1813,7 +1812,7 @@ otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Ne
 #endif
 
                 // If frame counter is one off, then frame is a duplicate.
-                VerifyOrExit((frameCounter + 1) != neighborFrameCounter, error = OT_ERROR_DUPLICATED);
+                VerifyOrExit((frameCounter + 1) != neighborFrameCounter, error = kErrorDuplicated);
 
                 VerifyOrExit(frameCounter >= neighborFrameCounter);
             }
@@ -1867,16 +1866,16 @@ otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Ne
         }
     }
 
-    error = OT_ERROR_NONE;
+    error = kErrorNone;
 
 exit:
     return error;
 }
 
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
-otError Mac::ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame)
+Error Mac::ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame)
 {
-    otError     error = OT_ERROR_SECURITY;
+    Error       error = kErrorSecurity;
     uint8_t     securityLevel;
     uint8_t     txKeyId;
     uint8_t     ackKeyId;
@@ -1888,14 +1887,14 @@ otError Mac::ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame)
     KeyManager &keyManager = Get<KeyManager>();
     const Key * macKey;
 
-    VerifyOrExit(aAckFrame.GetSecurityEnabled(), error = OT_ERROR_NONE);
+    VerifyOrExit(aAckFrame.GetSecurityEnabled(), error = kErrorNone);
     VerifyOrExit(aAckFrame.IsVersion2015());
 
     IgnoreError(aAckFrame.GetSecurityLevel(securityLevel));
     VerifyOrExit(securityLevel == Frame::kSecEncMic32);
 
     IgnoreError(aAckFrame.GetKeyIdMode(keyIdMode));
-    VerifyOrExit(keyIdMode == Frame::kKeyIdMode1, error = OT_ERROR_NONE);
+    VerifyOrExit(keyIdMode == Frame::kKeyIdMode1, error = kErrorNone);
 
     IgnoreError(aTxFrame.GetKeyId(txKeyId));
     IgnoreError(aAckFrame.GetKeyId(ackKeyId));
@@ -1962,7 +1961,7 @@ otError Mac::ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame)
     }
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         otLogInfoMac("Frame tx attempt failed, error: Enh-ACK security check fail");
     }
@@ -1971,19 +1970,19 @@ exit:
 }
 #endif // OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
 
-void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
+void Mac::HandleReceivedFrame(RxFrame *aFrame, Error aError)
 {
     Address   srcaddr;
     Address   dstaddr;
     PanId     panid;
     Neighbor *neighbor;
-    otError   error = aError;
+    Error     error = aError;
 
     mCounters.mRxTotal++;
 
     SuccessOrExit(error);
-    VerifyOrExit(aFrame != nullptr, error = OT_ERROR_NO_FRAME_RECEIVED);
+    VerifyOrExit(aFrame != nullptr, error = kErrorNoFrameReceived);
-    VerifyOrExit(IsEnabled(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(IsEnabled(), error = kErrorInvalidState);
 
     // Ensure we have a valid frame before attempting to read any contents of
     // the buffer received from the radio.
@@ -2001,7 +2000,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
 
     case Address::kTypeShort:
         VerifyOrExit((mRxOnWhenIdle && dstaddr.IsBroadcast()) || dstaddr.GetShort() == GetShortAddress(),
-                     error = OT_ERROR_DESTINATION_ADDRESS_FILTERED);
+                     error = kErrorDestinationAddressFiltered);
 
 #if OPENTHREAD_FTD
         // Allow multicasts from neighbor routers if FTD
@@ -2014,14 +2013,14 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
         break;
 
     case Address::kTypeExtended:
-        VerifyOrExit(dstaddr.GetExtended() == GetExtAddress(), error = OT_ERROR_DESTINATION_ADDRESS_FILTERED);
+        VerifyOrExit(dstaddr.GetExtended() == GetExtAddress(), error = kErrorDestinationAddressFiltered);
         break;
     }
 
     // Verify destination PAN ID if present
-    if (OT_ERROR_NONE == aFrame->GetDstPanId(panid))
+    if (kErrorNone == aFrame->GetDstPanId(panid))
     {
-        VerifyOrExit(panid == kShortAddrBroadcast || panid == mPanId, error = OT_ERROR_DESTINATION_ADDRESS_FILTERED);
+        VerifyOrExit(panid == kShortAddrBroadcast || panid == mPanId, error = kErrorDestinationAddressFiltered);
     }
 
     // Source Address Filtering
@@ -2033,7 +2032,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
     case Address::kTypeShort:
         otLogDebgMac("Received frame from short address 0x%04x", srcaddr.GetShort());
 
-        VerifyOrExit(neighbor != nullptr, error = OT_ERROR_UNKNOWN_NEIGHBOR);
+        VerifyOrExit(neighbor != nullptr, error = kErrorUnknownNeighbor);
 
         srcaddr.SetExtended(neighbor->GetExtAddress());
 
@@ -2042,7 +2041,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
     case Address::kTypeExtended:
 
         // Duplicate Address Protection
-        VerifyOrExit(srcaddr.GetExtended() != GetExtAddress(), error = OT_ERROR_INVALID_SOURCE_ADDRESS);
+        VerifyOrExit(srcaddr.GetExtended() != GetExtAddress(), error = kErrorInvalidSourceAddress);
 
 #if OPENTHREAD_CONFIG_MAC_FILTER_ENABLE
         {
@@ -2080,7 +2079,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
 
     switch (error)
     {
-    case OT_ERROR_DUPLICATED:
+    case kErrorDuplicated:
 
         // Allow a duplicate received frame pass, only if the
         // current operation is `kOperationWaitingForData` (i.e.,
@@ -2099,7 +2098,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
 
         OT_FALL_THROUGH;
 
-    case OT_ERROR_NONE:
+    case kErrorNone:
         break;
 
     default:
@@ -2139,11 +2138,11 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
                 case Neighbor::kStateChildUpdateRequest:
 
                     // Only accept a "MAC Data Request" frame from a child being restored.
-                    VerifyOrExit(aFrame->IsDataRequestCommand(), error = OT_ERROR_DROP);
+                    VerifyOrExit(aFrame->IsDataRequestCommand(), error = kErrorDrop);
                     break;
 
                 default:
-                    ExitNow(error = OT_ERROR_UNKNOWN_NEIGHBOR);
+                    ExitNow(error = kErrorUnknownNeighbor);
                 }
 
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2 && OPENTHREAD_FTD
@@ -2214,7 +2213,7 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
     case Frame::kFcfFrameMacCmd:
         if (HandleMacCommand(*aFrame)) // returns `true` when handled
         {
-            ExitNow(error = OT_ERROR_NONE);
+            ExitNow(error = kErrorNone);
         }
 
         break;
@@ -2239,41 +2238,41 @@ void Mac::HandleReceivedFrame(RxFrame *aFrame, otError aError)
 
 exit:
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         LogFrameRxFailure(aFrame, error);
 
         switch (error)
         {
-        case OT_ERROR_SECURITY:
+        case kErrorSecurity:
             mCounters.mRxErrSec++;
             break;
 
-        case OT_ERROR_FCS:
+        case kErrorFcs:
             mCounters.mRxErrFcs++;
             break;
 
-        case OT_ERROR_NO_FRAME_RECEIVED:
+        case kErrorNoFrameReceived:
             mCounters.mRxErrNoFrame++;
             break;
 
-        case OT_ERROR_UNKNOWN_NEIGHBOR:
+        case kErrorUnknownNeighbor:
             mCounters.mRxErrUnknownNeighbor++;
             break;
 
-        case OT_ERROR_INVALID_SOURCE_ADDRESS:
+        case kErrorInvalidSourceAddress:
             mCounters.mRxErrInvalidSrcAddr++;
             break;
 
-        case OT_ERROR_ADDRESS_FILTERED:
+        case kErrorAddressFiltered:
             mCounters.mRxAddressFiltered++;
             break;
 
-        case OT_ERROR_DESTINATION_ADDRESS_FILTERED:
+        case kErrorDestinationAddressFiltered:
             mCounters.mRxDestAddrFiltered++;
             break;
 
-        case OT_ERROR_DUPLICATED:
+        case kErrorDuplicated:
             mCounters.mRxDuplicated++;
             break;
 
@@ -2412,15 +2411,15 @@ const char *Mac::OperationToString(Operation aOperation)
     return kOperationStrings[aOperation];
 }
 
-void Mac::LogFrameRxFailure(const RxFrame *aFrame, otError aError) const
+void Mac::LogFrameRxFailure(const RxFrame *aFrame, Error aError) const
 {
     otLogLevel logLevel;
 
     switch (aError)
     {
-    case OT_ERROR_ABORT:
+    case kErrorAbort:
-    case OT_ERROR_NO_FRAME_RECEIVED:
+    case kErrorNoFrameReceived:
-    case OT_ERROR_DESTINATION_ADDRESS_FILTERED:
+    case kErrorDestinationAddressFiltered:
         logLevel = OT_LOG_LEVEL_DEBG;
         break;
 
@@ -2431,16 +2430,15 @@ void Mac::LogFrameRxFailure(const RxFrame *aFrame, otError aError) const
 
     if (aFrame == nullptr)
     {
-        otLogMac(logLevel, "Frame rx failed, error:%s", otThreadErrorToString(aError));
+        otLogMac(logLevel, "Frame rx failed, error:%s", ErrorToString(aError));
     }
     else
     {
-        otLogMac(logLevel, "Frame rx failed, error:%s, %s", otThreadErrorToString(aError),
+        otLogMac(logLevel, "Frame rx failed, error:%s, %s", ErrorToString(aError), aFrame->ToInfoString().AsCString());
-                 aFrame->ToInfoString().AsCString());
     }
 }
 
-void Mac::LogFrameTxFailure(const TxFrame &aFrame, otError aError, uint8_t aRetryCount, bool aWillRetx) const
+void Mac::LogFrameTxFailure(const TxFrame &aFrame, Error aError, uint8_t aRetryCount, bool aWillRetx) const
 {
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE && OPENTHREAD_CONFIG_MULTI_RADIO
     if (aFrame.GetRadioType() == kRadioTypeIeee802154)
@@ -2453,12 +2451,12 @@ void Mac::LogFrameTxFailure(const TxFrame &aFrame, otError aError, uint8_t aRetr
         uint8_t maxAttempts = aFrame.GetMaxFrameRetries() + 1;
         uint8_t curAttempt  = aWillRetx ? (aRetryCount + 1) : maxAttempts;
 
-        otLogInfoMac("Frame tx attempt %d/%d failed, error:%s, %s", curAttempt, maxAttempts,
+        otLogInfoMac("Frame tx attempt %d/%d failed, error:%s, %s", curAttempt, maxAttempts, ErrorToString(aError),
-                     otThreadErrorToString(aError), aFrame.ToInfoString().AsCString());
+                     aFrame.ToInfoString().AsCString());
     }
     else
     {
-        otLogInfoMac("Frame tx failed, error:%s, %s", otThreadErrorToString(aError), aFrame.ToInfoString().AsCString());
+        otLogInfoMac("Frame tx failed, error:%s, %s", ErrorToString(aError), aFrame.ToInfoString().AsCString());
     }
 }
 
@@ -2469,7 +2467,7 @@ void Mac::LogBeacon(const char *aActionText, const BeaconPayload &aBeaconPayload
 
 #else // #if (OPENTHREAD_CONFIG_LOG_LEVEL >= OT_LOG_LEVEL_INFO) && (OPENTHREAD_CONFIG_LOG_MAC == 1)
 
-void Mac::LogFrameRxFailure(const RxFrame *, otError) const
+void Mac::LogFrameRxFailure(const RxFrame *, Error) const
 {
 }
 
@@ -2477,7 +2475,7 @@ void Mac::LogBeacon(const char *, const BeaconPayload &) const
 {
 }
 
-void Mac::LogFrameTxFailure(const TxFrame &, otError, uint8_t, bool) const
+void Mac::LogFrameTxFailure(const TxFrame &, Error, uint8_t, bool) const
 {
 }
 

src/core/mac/mac.hpp

@@ -147,11 +147,11 @@ public:
      * @param[in]  aHandler       A pointer to a function that is called on receiving an IEEE 802.15.4 Beacon.
      * @param[in]  aContext       A pointer to an arbitrary context (used when invoking `aHandler` callback).
      *
-     * @retval OT_ERROR_NONE  Successfully scheduled the Active Scan request.
+     * @retval kErrorNone  Successfully scheduled the Active Scan request.
-     * @retval OT_ERROR_BUSY  Could not schedule the scan (a scan is ongoing or scheduled).
+     * @retval kErrorBusy  Could not schedule the scan (a scan is ongoing or scheduled).
      *
      */
-    otError ActiveScan(uint32_t aScanChannels, uint16_t aScanDuration, ActiveScanHandler aHandler, void *aContext);
+    Error ActiveScan(uint32_t aScanChannels, uint16_t aScanDuration, ActiveScanHandler aHandler, void *aContext);
 
     /**
      * This method starts an IEEE 802.15.4 Energy Scan.
@@ -162,11 +162,11 @@ public:
      * @param[in]  aHandler          A pointer to a function called to pass on scan result or indicate scan completion.
      * @param[in]  aContext          A pointer to an arbitrary context (used when invoking @p aHandler callback).
      *
-     * @retval OT_ERROR_NONE  Accepted the Energy Scan request.
+     * @retval kErrorNone  Accepted the Energy Scan request.
-     * @retval OT_ERROR_BUSY  Could not start the energy scan.
+     * @retval kErrorBusy  Could not start the energy scan.
      *
      */
-    otError EnergyScan(uint32_t aScanChannels, uint16_t aScanDuration, EnergyScanHandler aHandler, void *aContext);
+    Error EnergyScan(uint32_t aScanChannels, uint16_t aScanDuration, EnergyScanHandler aHandler, void *aContext);
 
     /**
      * This method indicates the energy scan for the current channel is complete.
@@ -240,23 +240,23 @@ public:
      *
      * @param[in]  aOobFrame  A pointer to the frame.
      *
-     * @retval OT_ERROR_NONE           Successfully scheduled the frame transmission.
+     * @retval kErrorNone          Successfully scheduled the frame transmission.
-     * @retval OT_ERROR_ALREADY        MAC layer is busy sending a previously requested frame.
+     * @retval kErrorAlready       MAC layer is busy sending a previously requested frame.
-     * @retval OT_ERROR_INVALID_STATE  The MAC layer is not enabled.
+     * @retval kErrorInvalidState  The MAC layer is not enabled.
-     * @retval OT_ERROR_INVALID_ARGS   The argument @p aOobFrame is nullptr.
+     * @retval kErrorInvalidArgs   The argument @p aOobFrame is nullptr.
      *
      */
-    otError RequestOutOfBandFrameTransmission(otRadioFrame *aOobFrame);
+    Error RequestOutOfBandFrameTransmission(otRadioFrame *aOobFrame);
 
     /**
      * This method requests transmission of a data poll (MAC Data Request) frame.
      *
-     * @retval OT_ERROR_NONE           Data poll transmission request is scheduled successfully.
+     * @retval kErrorNone          Data poll transmission request is scheduled successfully.
-     * @retval OT_ERROR_ALREADY        MAC is busy sending earlier poll transmission request.
+     * @retval kErrorAlready       MAC is busy sending earlier poll transmission request.
-     * @retval OT_ERROR_INVALID_STATE  The MAC layer is not enabled.
+     * @retval kErrorInvalidState  The MAC layer is not enabled.
      *
      */
-    otError RequestDataPollTransmission(void);
+    Error RequestDataPollTransmission(void);
 
     /**
      * This method returns a reference to the IEEE 802.15.4 Extended Address.
@@ -303,11 +303,11 @@ public:
      *
      * @param[in]  aChannel  The IEEE 802.15.4 PAN Channel.
      *
-     * @retval OT_ERROR_NONE           Successfully set the IEEE 802.15.4 PAN Channel.
+     * @retval kErrorNone          Successfully set the IEEE 802.15.4 PAN Channel.
-     * @retval OT_ERROR_INVALID_ARGS   The @p aChannel is not in the supported channel mask.
+     * @retval kErrorInvalidArgs   The @p aChannel is not in the supported channel mask.
      *
      */
-    otError SetPanChannel(uint8_t aChannel);
+    Error SetPanChannel(uint8_t aChannel);
 
     /**
      * This method sets the temporary IEEE 802.15.4 radio channel.
@@ -319,11 +319,11 @@ public:
      *
      * @param[in]  aChannel            A IEEE 802.15.4 channel.
      *
-     * @retval OT_ERROR_NONE           Successfully set the temporary channel
+     * @retval kErrorNone          Successfully set the temporary channel
-     * @retval OT_ERROR_INVALID_ARGS   The @p aChannel is not in the supported channel mask.
+     * @retval kErrorInvalidArgs   The @p aChannel is not in the supported channel mask.
      *
      */
-    otError SetTemporaryChannel(uint8_t aChannel);
+    Error SetTemporaryChannel(uint8_t aChannel);
 
     /**
      * This method clears the use of a previously set temporary channel and adopts the PAN channel.
@@ -360,22 +360,22 @@ public:
      *
      * @param[in]  aNameString   A pointer to a string character array. Must be null terminated.
      *
-     * @retval OT_ERROR_NONE           Successfully set the IEEE 802.15.4 Network Name.
+     * @retval kErrorNone          Successfully set the IEEE 802.15.4 Network Name.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError SetNetworkName(const char *aNameString);
+    Error SetNetworkName(const char *aNameString);
 
     /**
      * This method sets the IEEE 802.15.4 Network Name.
      *
      * @param[in]  aNameData     A name data (pointer to char buffer and length).
      *
-     * @retval OT_ERROR_NONE           Successfully set the IEEE 802.15.4 Network Name.
+     * @retval kErrorNone          Successfully set the IEEE 802.15.4 Network Name.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError SetNetworkName(const NameData &aNameData);
+    Error SetNetworkName(const NameData &aNameData);
 
 #if (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
     /**
@@ -391,22 +391,22 @@ public:
      *
      * @param[in]  aNameString   A pointer to a string character array. Must be null terminated.
      *
-     * @retval OT_ERROR_NONE           Successfully set the Thread Domain Name.
+     * @retval kErrorNone          Successfully set the Thread Domain Name.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError SetDomainName(const char *aNameString);
+    Error SetDomainName(const char *aNameString);
 
     /**
      * This method sets the Thread Domain Name.
      *
      * @param[in]  aNameData     A name data (pointer to char buffer and length).
      *
-     * @retval OT_ERROR_NONE           Successfully set the Thread Domain Name.
+     * @retval kErrorNone          Successfully set the Thread Domain Name.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError SetDomainName(const NameData &aNameData);
+    Error SetDomainName(const NameData &aNameData);
 #endif // (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 
     /**
@@ -482,11 +482,11 @@ public:
      * This method is called to handle a received frame.
      *
      * @param[in]  aFrame  A pointer to the received frame, or nullptr if the receive operation was aborted.
-     * @param[in]  aError  OT_ERROR_NONE when successfully received a frame,
+     * @param[in]  aError  kErrorNone when successfully received a frame,
-     *                     OT_ERROR_ABORT when reception was aborted and a frame was not received.
+     *                     kErrorAbort when reception was aborted and a frame was not received.
      *
      */
-    void HandleReceivedFrame(RxFrame *aFrame, otError aError);
+    void HandleReceivedFrame(RxFrame *aFrame, Error aError);
 
     /**
      * This method records CCA status (success/failure) for a frame transmission attempt.
@@ -505,10 +505,10 @@ public:
      *
      * @param[in] aFrame      The transmitted frame.
      * @param[in] aAckFrame   A pointer to the ACK frame, or nullptr if no ACK was received.
-     * @param[in] aError      OT_ERROR_NONE when the frame was transmitted successfully,
+     * @param[in] aError      kErrorNone when the frame was transmitted successfully,
-     *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+     *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-     *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+     *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-     *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+     *                        kErrorAbort when transmission was aborted for other reasons.
      * @param[in] aRetryCount Indicates number of transmission retries for this frame.
      * @param[in] aWillRetx   Indicates whether frame will be retransmitted or not. This is applicable only
      *                        when there was an error in transmission (i.e., `aError` is not NONE).
@@ -516,7 +516,7 @@ public:
      */
     void RecordFrameTransmitStatus(const TxFrame &aFrame,
                                    const RxFrame *aAckFrame,
-                                   otError        aError,
+                                   Error          aError,
                                    uint8_t        aRetryCount,
                                    bool           aWillRetx);
 
@@ -525,13 +525,13 @@ public:
      *
      * @param[in]  aFrame      The frame that was transmitted.
      * @param[in]  aAckFrame   A pointer to the ACK frame, nullptr if no ACK was received.
-     * @param[in]  aError      OT_ERROR_NONE when the frame was transmitted successfully,
+     * @param[in]  aError      kErrorNone when the frame was transmitted successfully,
-     *                         OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+     *                         kErrorNoAck when the frame was transmitted but no ACK was received,
-     *                         OT_ERROR_CHANNEL_ACCESS_FAILURE when the tx failed due to activity on the channel,
+     *                         kErrorChannelAccessFailure when the tx failed due to activity on the channel,
-     *                         OT_ERROR_ABORT when transmission was aborted for other reasons.
+     *                         kErrorAbort when transmission was aborted for other reasons.
      *
      */
-    void HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError);
+    void HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError);
 
     /**
      * This method returns if an active scan is in progress.
@@ -795,10 +795,10 @@ private:
     };
 #endif // OPENTHREAD_CONFIG_MAC_RETRY_SUCCESS_HISTOGRAM_ENABLE
 
-    otError ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Neighbor *aNeighbor);
+    Error ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Neighbor *aNeighbor);
-    void    ProcessTransmitSecurity(TxFrame &aFrame);
+    void  ProcessTransmitSecurity(TxFrame &aFrame);
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
-    otError ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame);
+    Error ProcessEnhAckSecurity(TxFrame &aTxFrame, RxFrame &aAckFrame);
 #endif
 
     void     UpdateIdleMode(void);
@@ -817,16 +817,16 @@ private:
     void        HandleTimer(void);
     static void HandleOperationTask(Tasklet &aTasklet);
 
-    void    Scan(Operation aScanOperation, uint32_t aScanChannels, uint16_t aScanDuration);
+    void  Scan(Operation aScanOperation, uint32_t aScanChannels, uint16_t aScanDuration);
-    otError UpdateScanChannel(void);
+    Error UpdateScanChannel(void);
-    void    PerformActiveScan(void);
+    void  PerformActiveScan(void);
-    void    ReportActiveScanResult(const RxFrame *aBeaconFrame);
+    void  ReportActiveScanResult(const RxFrame *aBeaconFrame);
-    otError ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, ActiveScanResult &aResult);
+    Error ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, ActiveScanResult &aResult);
-    void    PerformEnergyScan(void);
+    void  PerformEnergyScan(void);
-    void    ReportEnergyScanResult(int8_t aRssi);
+    void  ReportEnergyScanResult(int8_t aRssi);
 
-    void LogFrameRxFailure(const RxFrame *aFrame, otError aError) const;
+    void LogFrameRxFailure(const RxFrame *aFrame, Error aError) const;
-    void LogFrameTxFailure(const TxFrame &aFrame, otError aError, uint8_t aRetryCount, bool aWillRetx) const;
+    void LogFrameTxFailure(const TxFrame &aFrame, Error aError, uint8_t aRetryCount, bool aWillRetx) const;
     void LogBeacon(const char *aActionText, const BeaconPayload &aBeaconPayload) const;
 
 #if OPENTHREAD_CONFIG_TIME_SYNC_ENABLE
@@ -917,7 +917,7 @@ private:
 
 #if OPENTHREAD_CONFIG_MULTI_RADIO
     RadioTypes mTxPendingRadioLinks;
-    otError    mTxError;
+    Error      mTxError;
 #endif
 
 #if OPENTHREAD_CONFIG_MAC_FILTER_ENABLE

src/core/mac/mac_filter.cpp

@@ -83,14 +83,14 @@ exit:
     return rval;
 }
 
-otError Filter::AddAddress(const ExtAddress &aExtAddress)
+Error Filter::AddAddress(const ExtAddress &aExtAddress)
 {
-    otError      error = OT_ERROR_NONE;
+    Error        error = kErrorNone;
     FilterEntry *entry = FindEntry(aExtAddress);
 
     if (entry == nullptr)
     {
-        VerifyOrExit((entry = FindAvailableEntry()) != nullptr, error = OT_ERROR_NO_BUFS);
+        VerifyOrExit((entry = FindAvailableEntry()) != nullptr, error = kErrorNoBufs);
         entry->mExtAddress = aExtAddress;
     }
 
@@ -118,9 +118,9 @@ void Filter::ClearAddresses(void)
     }
 }
 
-otError Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry) const
+Error Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry) const
 {
-    otError error = OT_ERROR_NOT_FOUND;
+    Error error = kErrorNotFound;
 
     for (; aIterator < OT_ARRAY_LENGTH(mFilterEntries); aIterator++)
     {
@@ -130,7 +130,7 @@ otError Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry) const
         {
             aEntry.mExtAddress = entry.mExtAddress;
             aEntry.mRssIn      = entry.mRssIn;
-            error              = OT_ERROR_NONE;
+            error              = kErrorNone;
             aIterator++;
             break;
         }
@@ -139,15 +139,15 @@ otError Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry) const
     return error;
 }
 
-otError Filter::AddRssIn(const ExtAddress &aExtAddress, int8_t aRss)
+Error Filter::AddRssIn(const ExtAddress &aExtAddress, int8_t aRss)
 {
-    otError      error = OT_ERROR_NONE;
+    Error        error = kErrorNone;
     FilterEntry *entry = FindEntry(aExtAddress);
 
     if (entry == nullptr)
     {
         entry = FindAvailableEntry();
-        VerifyOrExit(entry != nullptr, error = OT_ERROR_NO_BUFS);
+        VerifyOrExit(entry != nullptr, error = kErrorNoBufs);
 
         entry->mExtAddress = aExtAddress;
     }
@@ -180,9 +180,9 @@ void Filter::ClearAllRssIn(void)
     mDefaultRssIn = kFixedRssDisabled;
 }
 
-otError Filter::GetNextRssIn(Iterator &aIterator, Entry &aEntry)
+Error Filter::GetNextRssIn(Iterator &aIterator, Entry &aEntry)
 {
-    otError error = OT_ERROR_NOT_FOUND;
+    Error error = kErrorNotFound;
 
     for (; aIterator < OT_ARRAY_LENGTH(mFilterEntries); aIterator++)
     {
@@ -192,7 +192,7 @@ otError Filter::GetNextRssIn(Iterator &aIterator, Entry &aEntry)
         {
             aEntry.mExtAddress = entry.mExtAddress;
             aEntry.mRssIn      = entry.mRssIn;
-            error              = OT_ERROR_NONE;
+            error              = kErrorNone;
             aIterator++;
             ExitNow();
         }
@@ -203,7 +203,7 @@ otError Filter::GetNextRssIn(Iterator &aIterator, Entry &aEntry)
     {
         static_cast<ExtAddress &>(aEntry.mExtAddress).Fill(0xff);
         aEntry.mRssIn = mDefaultRssIn;
-        error         = OT_ERROR_NONE;
+        error         = kErrorNone;
         aIterator++;
     }
 
@@ -211,9 +211,9 @@ exit:
     return error;
 }
 
-otError Filter::Apply(const ExtAddress &aExtAddress, int8_t &aRss)
+Error Filter::Apply(const ExtAddress &aExtAddress, int8_t &aRss)
 {
-    otError      error = OT_ERROR_NONE;
+    Error        error = kErrorNone;
     FilterEntry *entry = FindEntry(aExtAddress);
     bool         isInFilterList;
 
@@ -231,11 +231,11 @@ otError Filter::Apply(const ExtAddress &aExtAddress, int8_t &aRss)
         break;
 
     case kModeAllowlist:
-        VerifyOrExit(isInFilterList, error = OT_ERROR_ADDRESS_FILTERED);
+        VerifyOrExit(isInFilterList, error = kErrorAddressFiltered);
         break;
 
     case kModeDenylist:
-        VerifyOrExit(!isInFilterList, error = OT_ERROR_ADDRESS_FILTERED);
+        VerifyOrExit(!isInFilterList, error = kErrorAddressFiltered);
         break;
     }
 

src/core/mac/mac_filter.hpp

@@ -117,11 +117,11 @@ public:
      *
      * @param[in]  aExtAddress  A reference to the Extended Address.
      *
-     * @retval OT_ERROR_NONE           Successfully added @p aExtAddress to the filter.
+     * @retval kErrorNone          Successfully added @p aExtAddress to the filter.
-     * @retval OT_ERROR_NO_BUFS        No available entry exists.
+     * @retval kErrorNoBufs        No available entry exists.
      *
      */
-    otError AddAddress(const ExtAddress &aExtAddress);
+    Error AddAddress(const ExtAddress &aExtAddress);
 
     /**
      * This method removes an Extended Address from the filter.
@@ -146,11 +146,11 @@ public:
      *                           To get the first in-use address filter, set it to OT_MAC_FILTER_ITERATOR_INIT.
      * @param[out]     aEntry    A reference to where the information is placed.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the next address filter entry.
+     * @retval kErrorNone      Successfully retrieved the next address filter entry.
-     * @retval OT_ERROR_NOT_FOUND  No subsequent entry exists.
+     * @retval kErrorNotFound  No subsequent entry exists.
      *
      */
-    otError GetNextAddress(Iterator &aIterator, Entry &aEntry) const;
+    Error GetNextAddress(Iterator &aIterator, Entry &aEntry) const;
 
     /**
      * This method adds a fixed received signal strength entry for the messages from a given Extended Address.
@@ -158,11 +158,11 @@ public:
      * @param[in]  aExtAddress  An Extended Address
      * @param[in]  aRss         The received signal strength to set.
      *
-     * @retval OT_ERROR_NONE     Successfully set @p aRss for @p aExtAddress.
+     * @retval kErrorNone    Successfully set @p aRss for @p aExtAddress.
-     * @retval OT_ERROR_NO_BUFS  No available entry exists.
+     * @retval kErrorNoBufs  No available entry exists.
      *
      */
-    otError AddRssIn(const ExtAddress &aExtAddress, int8_t aRss);
+    Error AddRssIn(const ExtAddress &aExtAddress, int8_t aRss);
 
     /**
      * This method removes a fixed received signal strength entry for a given Extended Address.
@@ -206,11 +206,11 @@ public:
      *                           Extended Address as all 0xff to indicate the default received signal strength
      *                           if it was set.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the next RssIn filter entry.
+     * @retval kErrorNone      Successfully retrieved the next RssIn filter entry.
-     * @retval OT_ERROR_NOT_FOUND  No subsequent entry exists.
+     * @retval kErrorNotFound  No subsequent entry exists.
      *
      */
-    otError GetNextRssIn(Iterator &aIterator, Entry &aEntry);
+    Error GetNextRssIn(Iterator &aIterator, Entry &aEntry);
 
     /**
      * This method applies the filter rules on a given Extended Address.
@@ -218,12 +218,11 @@ public:
      * @param[in]  aExtAddress  A reference to the Extended Address.
      * @param[out] aRss         A reference to where the received signal strength to be placed.
      *
-     * @retval OT_ERROR_NONE                Successfully applied the filter rules on @p aExtAddress.
+     * @retval kErrorNone             Successfully applied the filter rules on @p aExtAddress.
-     * @retval OT_ERROR_ADDRESS_FILTERED    Address filter (allowlist or denylist) is enabled and @p aExtAddress is
+     * @retval kErrorAddressFiltered  Address filter (allowlist or denylist) is enabled and @p aExtAddress is filtered.
-     *                                      filtered.
      *
      */
-    otError Apply(const ExtAddress &aExtAddress, int8_t &aRss);
+    Error Apply(const ExtAddress &aExtAddress, int8_t &aRss);
 
 private:
     enum

src/core/mac/mac_frame.cpp

@@ -86,13 +86,13 @@ uint16_t Frame::GetFrameControlField(void) const
     return ReadUint16(mPsdu);
 }
 
-otError Frame::ValidatePsdu(void) const
+Error Frame::ValidatePsdu(void) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindPayloadIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
-    VerifyOrExit((index + GetFooterLength()) <= mLength, error = OT_ERROR_PARSE);
+    VerifyOrExit((index + GetFooterLength()) <= mLength, error = kErrorParse);
 
 exit:
     return error;
@@ -166,12 +166,12 @@ bool Frame::IsDstPanIdPresent(uint16_t aFcf)
     return present;
 }
 
-otError Frame::GetDstPanId(PanId &aPanId) const
+Error Frame::GetDstPanId(PanId &aPanId) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindDstPanIdIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
     aPanId = ReadUint16(&mPsdu[index]);
 
 exit:
@@ -191,12 +191,12 @@ uint8_t Frame::FindDstAddrIndex(void) const
     return kFcfSize + kDsnSize + (IsDstPanIdPresent() ? sizeof(PanId) : 0);
 }
 
-otError Frame::GetDstAddr(Address &aAddress) const
+Error Frame::GetDstAddr(Address &aAddress) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindDstAddrIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     switch (GetFrameControlField() & kFcfDstAddrMask)
     {
@@ -304,24 +304,24 @@ bool Frame::IsSrcPanIdPresent(uint16_t aFcf)
     return srcPanIdPresent;
 }
 
-otError Frame::GetSrcPanId(PanId &aPanId) const
+Error Frame::GetSrcPanId(PanId &aPanId) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSrcPanIdIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
     aPanId = ReadUint16(&mPsdu[index]);
 
 exit:
     return error;
 }
 
-otError Frame::SetSrcPanId(PanId aPanId)
+Error Frame::SetSrcPanId(PanId aPanId)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSrcPanIdIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
     WriteUint16(aPanId, &mPsdu[index]);
 
 exit:
@@ -359,13 +359,13 @@ uint8_t Frame::FindSrcAddrIndex(void) const
     return index;
 }
 
-otError Frame::GetSrcAddr(Address &aAddress) const
+Error Frame::GetSrcAddr(Address &aAddress) const
 {
-    otError  error = OT_ERROR_NONE;
+    Error    error = kErrorNone;
     uint8_t  index = FindSrcAddrIndex();
     uint16_t fcf   = GetFrameControlField();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     switch (fcf & kFcfSrcAddrMask)
     {
@@ -423,12 +423,12 @@ void Frame::SetSrcAddr(const Address &aAddress)
     }
 }
 
-otError Frame::GetSecurityControlField(uint8_t &aSecurityControlField) const
+Error Frame::GetSecurityControlField(uint8_t &aSecurityControlField) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSecurityHeaderIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     aSecurityControlField = mPsdu[index];
 
@@ -457,12 +457,12 @@ exit:
     return index;
 }
 
-otError Frame::GetSecurityLevel(uint8_t &aSecurityLevel) const
+Error Frame::GetSecurityLevel(uint8_t &aSecurityLevel) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSecurityHeaderIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     aSecurityLevel = mPsdu[index] & kSecLevelMask;
 
@@ -470,12 +470,12 @@ exit:
     return error;
 }
 
-otError Frame::GetKeyIdMode(uint8_t &aKeyIdMode) const
+Error Frame::GetKeyIdMode(uint8_t &aKeyIdMode) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSecurityHeaderIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     aKeyIdMode = mPsdu[index] & kKeyIdModeMask;
 
@@ -483,12 +483,12 @@ exit:
     return error;
 }
 
-otError Frame::GetFrameCounter(uint32_t &aFrameCounter) const
+Error Frame::GetFrameCounter(uint32_t &aFrameCounter) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindSecurityHeaderIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     // Security Control
     index += kSecurityControlSize;
@@ -558,9 +558,9 @@ void Frame::SetKeySource(const uint8_t *aKeySource)
     memcpy(&mPsdu[index + kSecurityControlSize + kFrameCounterSize], aKeySource, keySourceLength);
 }
 
-otError Frame::GetKeyId(uint8_t &aKeyId) const
+Error Frame::GetKeyId(uint8_t &aKeyId) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t keySourceLength;
     uint8_t index = FindSecurityHeaderIndex();
 
@@ -586,11 +586,11 @@ void Frame::SetKeyId(uint8_t aKeyId)
     mPsdu[index + kSecurityControlSize + kFrameCounterSize + keySourceLength] = aKeyId;
 }
 
-otError Frame::GetCommandId(uint8_t &aCommandId) const
+Error Frame::GetCommandId(uint8_t &aCommandId) const
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindPayloadIndex();
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     aCommandId = mPsdu[IsVersion2015() ? index : (index - 1)];
 
@@ -598,12 +598,12 @@ exit:
     return error;
 }
 
-otError Frame::SetCommandId(uint8_t aCommandId)
+Error Frame::SetCommandId(uint8_t aCommandId)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t index = FindPayloadIndex();
 
-    VerifyOrExit(index != kInvalidIndex, error = OT_ERROR_PARSE);
+    VerifyOrExit(index != kInvalidIndex, error = kErrorParse);
 
     mPsdu[IsVersion2015() ? index : (index - 1)] = aCommandId;
 
@@ -894,9 +894,9 @@ exit:
 }
 
 #if OPENTHREAD_CONFIG_MAC_HEADER_IE_SUPPORT
-template <typename IeType> otError Frame::AppendHeaderIeAt(uint8_t &aIndex)
+template <typename IeType> Error Frame::AppendHeaderIeAt(uint8_t &aIndex)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     SuccessOrExit(error = InitIeHeaderAt(aIndex, IeType::kHeaderIeId, IeType::kIeContentSize));
 
@@ -906,16 +906,16 @@ exit:
     return error;
 }
 
-otError Frame::InitIeHeaderAt(uint8_t &aIndex, uint8_t ieId, uint8_t ieContentSize)
+Error Frame::InitIeHeaderAt(uint8_t &aIndex, uint8_t ieId, uint8_t ieContentSize)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     if (aIndex == 0)
     {
         aIndex = FindHeaderIeIndex();
     }
 
-    VerifyOrExit(aIndex != kInvalidIndex, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(aIndex != kInvalidIndex, error = kErrorNotFound);
 
     reinterpret_cast<HeaderIe *>(mPsdu + aIndex)->Init(ieId, ieContentSize);
     aIndex += sizeof(HeaderIe);
@@ -1123,12 +1123,12 @@ uint8_t Frame::GetFcsSize(void) const
 // Explicit instantiation
 #if OPENTHREAD_CONFIG_MAC_HEADER_IE_SUPPORT
 #if OPENTHREAD_CONFIG_TIME_SYNC_ENABLE
-template otError Frame::AppendHeaderIeAt<TimeIe>(uint8_t &aIndex);
+template Error Frame::AppendHeaderIeAt<TimeIe>(uint8_t &aIndex);
 #endif
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE
-template otError Frame::AppendHeaderIeAt<CslIe>(uint8_t &aIndex);
+template Error Frame::AppendHeaderIeAt<CslIe>(uint8_t &aIndex);
 #endif
-template otError Frame::AppendHeaderIeAt<Termination2Ie>(uint8_t &aIndex);
+template Error Frame::AppendHeaderIeAt<Termination2Ie>(uint8_t &aIndex);
 #endif
 
 void TxFrame::CopyFrom(const TxFrame &aFromFrame)
@@ -1222,9 +1222,9 @@ void TxFrame::GenerateImmAck(const RxFrame &aFrame, bool aIsFramePending)
 }
 
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
-otError TxFrame::GenerateEnhAck(const RxFrame &aFrame, bool aIsFramePending, const uint8_t *aIeData, uint8_t aIeLength)
+Error TxFrame::GenerateEnhAck(const RxFrame &aFrame, bool aIsFramePending, const uint8_t *aIeData, uint8_t aIeLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     uint16_t fcf = kFcfFrameAck | kFcfFrameVersion2015 | kFcfSrcAddrNone;
     Address  address;
@@ -1289,7 +1289,7 @@ otError TxFrame::GenerateEnhAck(const RxFrame &aFrame, bool aIsFramePending, con
         }
         else
         {
-            ExitNow(error = OT_ERROR_PARSE);
+            ExitNow(error = kErrorParse);
         }
 
         SetDstPanId(panId);
@@ -1332,15 +1332,15 @@ exit:
 }
 #endif // OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
 
-otError RxFrame::ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &aMacKey)
+Error RxFrame::ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &aMacKey)
 {
 #if OPENTHREAD_RADIO
     OT_UNUSED_VARIABLE(aExtAddress);
     OT_UNUSED_VARIABLE(aMacKey);
 
-    return OT_ERROR_NONE;
+    return kErrorNone;
 #else
-    otError        error        = OT_ERROR_SECURITY;
+    Error          error        = kErrorSecurity;
     uint32_t       frameCounter = 0;
     uint8_t        securityLevel;
     uint8_t        nonce[Crypto::AesCcm::kNonceSize];
@@ -1348,7 +1348,7 @@ otError RxFrame::ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &
     uint8_t        tagLength;
     Crypto::AesCcm aesCcm;
 
-    VerifyOrExit(GetSecurityEnabled(), error = OT_ERROR_NONE);
+    VerifyOrExit(GetSecurityEnabled(), error = kErrorNone);
 
     SuccessOrExit(GetSecurityLevel(securityLevel));
     SuccessOrExit(GetFrameCounter(frameCounter));
@@ -1373,7 +1373,7 @@ otError RxFrame::ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &
     VerifyOrExit(memcmp(tag, GetFooter(), tagLength) == 0);
 #endif
 
-    error = OT_ERROR_NONE;
+    error = kErrorNone;
 
 exit:
     return error;
@@ -1409,7 +1409,7 @@ Frame::InfoString Frame::ToInfoString(void) const
         break;
 
     case kFcfFrameMacCmd:
-        if (GetCommandId(commandId) != OT_ERROR_NONE)
+        if (GetCommandId(commandId) != kErrorNone)
         {
             commandId = 0xff;
         }

src/core/mac/mac_frame.hpp

@@ -407,11 +407,11 @@ public:
     /**
      * This method validates the frame.
      *
-     * @retval OT_ERROR_NONE    Successfully parsed the MAC header.
+     * @retval kErrorNone    Successfully parsed the MAC header.
-     * @retval OT_ERROR_PARSE   Failed to parse through the MAC header.
+     * @retval kErrorParse   Failed to parse through the MAC header.
      *
      */
-    otError ValidatePsdu(void) const;
+    Error ValidatePsdu(void) const;
 
     /**
      * This method returns the IEEE 802.15.4 Frame Type.
@@ -536,11 +536,11 @@ public:
      *
      * @param[out]  aPanId  The Destination PAN Identifier.
      *
-     * @retval OT_ERROR_NONE   Successfully retrieved the Destination PAN Identifier.
+     * @retval kErrorNone   Successfully retrieved the Destination PAN Identifier.
-     * @retval OT_ERROR_PARSE  Failed to parse the PAN Identifier.
+     * @retval kErrorParse  Failed to parse the PAN Identifier.
      *
      */
-    otError GetDstPanId(PanId &aPanId) const;
+    Error GetDstPanId(PanId &aPanId) const;
 
     /**
      * This method sets the Destination PAN Identifier.
@@ -563,10 +563,10 @@ public:
      *
      * @param[out]  aAddress  The Destination Address.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Destination Address.
+     * @retval kErrorNone  Successfully retrieved the Destination Address.
      *
      */
-    otError GetDstAddr(Address &aAddress) const;
+    Error GetDstAddr(Address &aAddress) const;
 
     /**
      * This method sets the Destination Address.
@@ -605,20 +605,20 @@ public:
      *
      * @param[out]  aPanId  The Source PAN Identifier.
      *
-     * @retval OT_ERROR_NONE   Successfully retrieved the Source PAN Identifier.
+     * @retval kErrorNone   Successfully retrieved the Source PAN Identifier.
      *
      */
-    otError GetSrcPanId(PanId &aPanId) const;
+    Error GetSrcPanId(PanId &aPanId) const;
 
     /**
      * This method sets the Source PAN Identifier.
      *
      * @param[in]  aPanId  The Source PAN Identifier.
      *
-     * @retval OT_ERROR_NONE   Successfully set the Source PAN Identifier.
+     * @retval kErrorNone   Successfully set the Source PAN Identifier.
      *
      */
-    otError SetSrcPanId(PanId aPanId);
+    Error SetSrcPanId(PanId aPanId);
 
     /**
      * This method indicates whether or not the Source Address is present for this object.
@@ -633,10 +633,10 @@ public:
      *
      * @param[out]  aAddress  The Source Address.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Source Address.
+     * @retval kErrorNone  Successfully retrieved the Source Address.
      *
      */
-    otError GetSrcAddr(Address &aAddress) const;
+    Error GetSrcAddr(Address &aAddress) const;
 
     /**
      * This method sets the Source Address.
@@ -667,11 +667,11 @@ public:
      *
      * @param[out]  aSecurityControlField  The Security Control Field.
      *
-     * @retval OT_ERROR_NONE   Successfully retrieved the Security Level Identifier.
+     * @retval kErrorNone   Successfully retrieved the Security Level Identifier.
-     * @retval OT_ERROR_PARSE  Failed to find the security control field in the frame.
+     * @retval kErrorParse  Failed to find the security control field in the frame.
      *
      */
-    otError GetSecurityControlField(uint8_t &aSecurityControlField) const;
+    Error GetSecurityControlField(uint8_t &aSecurityControlField) const;
 
     /**
      * This method sets the Security Control Field.
@@ -686,30 +686,30 @@ public:
      *
      * @param[out]  aSecurityLevel  The Security Level Identifier.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Security Level Identifier.
+     * @retval kErrorNone  Successfully retrieved the Security Level Identifier.
      *
      */
-    otError GetSecurityLevel(uint8_t &aSecurityLevel) const;
+    Error GetSecurityLevel(uint8_t &aSecurityLevel) const;
 
     /**
      * This method gets the Key Identifier Mode.
      *
      * @param[out]  aSecurityLevel  The Key Identifier Mode.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Key Identifier Mode.
+     * @retval kErrorNone  Successfully retrieved the Key Identifier Mode.
      *
      */
-    otError GetKeyIdMode(uint8_t &aKeyIdMode) const;
+    Error GetKeyIdMode(uint8_t &aKeyIdMode) const;
 
     /**
      * This method gets the Frame Counter.
      *
      * @param[out]  aFrameCounter  The Frame Counter.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Frame Counter.
+     * @retval kErrorNone  Successfully retrieved the Frame Counter.
      *
      */
-    otError GetFrameCounter(uint32_t &aFrameCounter) const;
+    Error GetFrameCounter(uint32_t &aFrameCounter) const;
 
     /**
      * This method sets the Frame Counter.
@@ -740,10 +740,10 @@ public:
      *
      * @param[out]  aKeyId  The Key Identifier.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Key Identifier.
+     * @retval kErrorNone  Successfully retrieved the Key Identifier.
      *
      */
-    otError GetKeyId(uint8_t &aKeyId) const;
+    Error GetKeyId(uint8_t &aKeyId) const;
 
     /**
      * This method sets the Key Identifier.
@@ -758,20 +758,20 @@ public:
      *
      * @param[out]  aCommandId  The Command ID.
      *
-     * @retval OT_ERROR_NONE  Successfully retrieved the Command ID.
+     * @retval kErrorNone  Successfully retrieved the Command ID.
      *
      */
-    otError GetCommandId(uint8_t &aCommandId) const;
+    Error GetCommandId(uint8_t &aCommandId) const;
 
     /**
      * This method sets the Command ID.
      *
      * @param[in]  aCommandId  The Command ID.
      *
-     * @retval OT_ERROR_NONE  Successfully set the Command ID.
+     * @retval kErrorNone  Successfully set the Command ID.
      *
      */
-    otError SetCommandId(uint8_t aCommandId);
+    Error SetCommandId(uint8_t aCommandId);
 
     /**
      * This method indicates whether the frame is a MAC Data Request command (data poll).
@@ -957,11 +957,11 @@ public:
      * @tparam  IeType  The Header IE type, it MUST contain an enum `kHeaderIeId` equal to the IE's Id
      *                  and an enum `kIeContentSize` indicating the IE body's size.
      *
-     * @retval OT_ERROR_NONE       Successfully appended the Header IE.
+     * @retval kErrorNone      Successfully appended the Header IE.
-     * @retval OT_ERROR_NOT_FOUND  The position for first IE is not found.
+     * @retval kErrorNotFound  The position for first IE is not found.
      *
      */
-    template <typename IeType> otError AppendHeaderIeAt(uint8_t &aIndex);
+    template <typename IeType> Error AppendHeaderIeAt(uint8_t &aIndex);
 
     /**
      * This method returns a pointer to the Header IE.
@@ -1121,7 +1121,7 @@ protected:
 #if OPENTHREAD_CONFIG_MAC_HEADER_IE_SUPPORT
     uint8_t FindHeaderIeIndex(void) const;
 
-    otError                         InitIeHeaderAt(uint8_t &aIndex, uint8_t ieId, uint8_t ieContentSize);
+    Error                           InitIeHeaderAt(uint8_t &aIndex, uint8_t ieId, uint8_t ieContentSize);
     template <typename IeType> void InitIeContentAt(uint8_t &aIndex);
 #endif
 
@@ -1203,11 +1203,11 @@ public:
      *                          for AES CCM computation.
      * @param[in]  aMacKey      A reference to the MAC key to decrypt the received frame.
      *
-     * @retval OT_ERROR_NONE      Process of received frame AES CCM succeeded.
+     * @retval kErrorNone      Process of received frame AES CCM succeeded.
-     * @retval OT_ERROR_SECURITY  Received frame MIC check failed.
+     * @retval kErrorSecurity  Received frame MIC check failed.
      *
      */
-    otError ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &aMacKey);
+    Error ProcessReceiveAesCcm(const ExtAddress &aExtAddress, const Key &aMacKey);
 
 #if OPENTHREAD_CONFIG_TIME_SYNC_ENABLE
     /**
@@ -1426,11 +1426,11 @@ public:
      * @param[in]    aIeData            A pointer to the IE data portion of the ACK to be sent.
      * @param[in]    aIeLength          The length of IE data portion of the ACK to be sent.
      *
-     * @retval  OT_ERROR_NONE           Successfully generated Enh Ack.
+     * @retval  kErrorNone           Successfully generated Enh Ack.
-     * @retval  OT_ERROR_PARSE          @p aFrame has incorrect format.
+     * @retval  kErrorParse          @p aFrame has incorrect format.
      *
      */
-    otError GenerateEnhAck(const RxFrame &aFrame, bool aIsFramePending, const uint8_t *aIeData, uint8_t aIeLength);
+    Error GenerateEnhAck(const RxFrame &aFrame, bool aIsFramePending, const uint8_t *aIeData, uint8_t aIeLength);
 
 #if OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2
     /**

src/core/mac/mac_links.cpp

@@ -159,9 +159,9 @@ void Links::Send(TxFrame &aFrame, RadioTypes aRadioTypes)
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE
     if (aRadioTypes.Contains(kRadioTypeIeee802154))
     {
-        otError error = mSubMac.Send();
+        Error error = mSubMac.Send();
 
-        OT_ASSERT(error == OT_ERROR_NONE);
+        OT_ASSERT(error == kErrorNone);
         OT_UNUSED_VARIABLE(error);
     }
 #endif

src/core/mac/mac_links.hpp

@@ -513,8 +513,8 @@ public:
     {
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE
         {
-            otError error = mSubMac.Send();
+            Error error = mSubMac.Send();
-            OT_ASSERT(error == OT_ERROR_NONE);
+            OT_ASSERT(error == kErrorNone);
             OT_UNUSED_VARIABLE(error);
         }
 #endif
@@ -576,12 +576,12 @@ public:
      * @param[in] aScanChannel   The channel to perform the energy scan on.
      * @param[in] aScanDuration  The duration, in milliseconds, for the channel to be scanned.
      *
-     * @retval OT_ERROR_NONE             Successfully started scanning the channel.
+     * @retval kErrorNone            Successfully started scanning the channel.
-     * @retval OT_ERROR_INVALID_STATE    The radio was disabled or transmitting.
+     * @retval kErrorInvalidState    The radio was disabled or transmitting.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  Energy scan is not supported by radio link.
+     * @retval kErrorNotImplemented  Energy scan is not supported by radio link.
      *
      */
-    otError EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
+    Error EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
     {
         OT_UNUSED_VARIABLE(aScanChannel);
         OT_UNUSED_VARIABLE(aScanDuration);
@@ -590,7 +590,7 @@ public:
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE
             mSubMac.EnergyScan(aScanChannel, aScanDuration);
 #else
-            OT_ERROR_NOT_IMPLEMENTED;
+            kErrorNotImplemented;
 #endif
     }
 
@@ -654,8 +654,8 @@ public:
      *
      * @param[in] TxFrame  The `TxFrame` from which to get the counter value.
      *
-     * @retval OT_ERROR_NONE             If successful.
+     * @retval kErrorNone            If successful.
-     * @retval OT_ERROR_INVALID_STATE    If the raw link-layer isn't enabled.
+     * @retval kErrorInvalidState    If the raw link-layer isn't enabled.
      *
      */
     void SetMacFrameCounter(TxFrame &aFrame);

src/core/mac/mac_types.cpp

@@ -128,15 +128,15 @@ NameData NetworkName::GetAsData(void) const
     return NameData(m8, len);
 }
 
-otError NetworkName::Set(const NameData &aNameData)
+Error NetworkName::Set(const NameData &aNameData)
 {
-    otError error  = OT_ERROR_NONE;
+    Error   error  = kErrorNone;
     uint8_t newLen = static_cast<uint8_t>(StringLength(aNameData.GetBuffer(), aNameData.GetLength()));
 
-    VerifyOrExit(newLen <= kMaxSize, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(newLen <= kMaxSize, error = kErrorInvalidArgs);
 
     // Ensure the new name does not match the current one.
-    VerifyOrExit(memcmp(m8, aNameData.GetBuffer(), newLen) || (m8[newLen] != '\0'), error = OT_ERROR_ALREADY);
+    VerifyOrExit(memcmp(m8, aNameData.GetBuffer(), newLen) || (m8[newLen] != '\0'), error = kErrorAlready);
 
     memcpy(m8, aNameData.GetBuffer(), newLen);
     m8[newLen] = '\0';
@@ -162,15 +162,15 @@ NameData DomainName::GetAsData(void) const
     return NameData(m8, len);
 }
 
-otError DomainName::Set(const NameData &aNameData)
+Error DomainName::Set(const NameData &aNameData)
 {
-    otError error  = OT_ERROR_NONE;
+    Error   error  = kErrorNone;
     uint8_t newLen = static_cast<uint8_t>(StringLength(aNameData.GetBuffer(), aNameData.GetLength()));
 
-    VerifyOrExit(newLen <= kMaxSize, error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(newLen <= kMaxSize, error = kErrorInvalidArgs);
 
     // Ensure the new name does not match the current one.
-    VerifyOrExit(memcmp(m8, aNameData.GetBuffer(), newLen) || (m8[newLen] != '\0'), error = OT_ERROR_ALREADY);
+    VerifyOrExit(memcmp(m8, aNameData.GetBuffer(), newLen) || (m8[newLen] != '\0'), error = kErrorAlready);
 
     memcpy(m8, aNameData.GetBuffer(), newLen);
     m8[newLen] = '\0';

src/core/mac/mac_types.hpp

@@ -564,12 +564,12 @@ public:
      *
      * @param[in]  aNameData           A reference to name data.
      *
-     * @retval OT_ERROR_NONE           Successfully set the IEEE 802.15.4 Network Name.
+     * @retval kErrorNone          Successfully set the IEEE 802.15.4 Network Name.
-     * @retval OT_ERROR_ALREADY        The name is already set to the same string.
+     * @retval kErrorAlready       The name is already set to the same string.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError Set(const NameData &aNameData);
+    Error Set(const NameData &aNameData);
 
     /**
      * This method overloads operator `==` to evaluate whether or not two given `NetworkName` objects are equal.
@@ -623,12 +623,12 @@ public:
      *
      * @param[in]  aNameData           A reference to name data.
      *
-     * @retval OT_ERROR_NONE           Successfully set the Thread Domain Name.
+     * @retval kErrorNone          Successfully set the Thread Domain Name.
-     * @retval OT_ERROR_ALREADY        The name is already set to the same string.
+     * @retval kErrorAlready       The name is already set to the same string.
-     * @retval OT_ERROR_INVALID_ARGS   Given name is too long.
+     * @retval kErrorInvalidArgs   Given name is too long.
      *
      */
-    otError Set(const NameData &aNameData);
+    Error Set(const NameData &aNameData);
 
 private:
     char m8[kMaxSize + 1]; ///< Byte values.

src/core/mac/sub_mac.cpp

@@ -151,9 +151,9 @@ void SubMac::SetPcapCallback(otLinkPcapCallback aPcapCallback, void *aCallbackCo
     mPcapCallbackContext = aCallbackContext;
 }
 
-otError SubMac::Enable(void)
+Error SubMac::Enable(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     VerifyOrExit(mState == kStateDisabled);
 
@@ -163,13 +163,13 @@ otError SubMac::Enable(void)
     SetState(kStateSleep);
 
 exit:
-    OT_ASSERT(error == OT_ERROR_NONE);
+    OT_ASSERT(error == kErrorNone);
     return error;
 }
 
-otError SubMac::Disable(void)
+Error SubMac::Disable(void)
 {
-    otError error;
+    Error error;
 
     mTimer.Stop();
     SuccessOrExit(error = Get<Radio>().Sleep());
@@ -180,13 +180,13 @@ exit:
     return error;
 }
 
-otError SubMac::Sleep(void)
+Error SubMac::Sleep(void)
 {
-    otError error = Get<Radio>().Sleep();
+    Error error = Get<Radio>().Sleep();
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnMac("RadioSleep() failed, error: %s", otThreadErrorToString(error));
+        otLogWarnMac("RadioSleep() failed, error: %s", ErrorToString(error));
         ExitNow();
     }
 
@@ -196,13 +196,13 @@ exit:
     return error;
 }
 
-otError SubMac::Receive(uint8_t aChannel)
+Error SubMac::Receive(uint8_t aChannel)
 {
-    otError error = Get<Radio>().Receive(aChannel);
+    Error error = Get<Radio>().Receive(aChannel);
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnMac("RadioReceive() failed, error: %s", otThreadErrorToString(error));
+        otLogWarnMac("RadioReceive() failed, error: %s", ErrorToString(error));
         ExitNow();
     }
 
@@ -213,9 +213,9 @@ exit:
 }
 
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE
-otError SubMac::CslSample(uint8_t aPanChannel)
+Error SubMac::CslSample(uint8_t aPanChannel)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     if (!IsCslChannelSpecified())
     {
@@ -233,7 +233,7 @@ otError SubMac::CslSample(uint8_t aPanChannel)
 #endif
         break;
     case kCslIdle:
-        ExitNow(error = OT_ERROR_INVALID_STATE);
+        ExitNow(error = kErrorInvalidState);
     default:
         OT_ASSERT(false);
     }
@@ -241,17 +241,17 @@ otError SubMac::CslSample(uint8_t aPanChannel)
     SetState(kStateCslSample);
 
 exit:
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
-        otLogWarnMac("CslSample() failed, error: %s", otThreadErrorToString(error));
+        otLogWarnMac("CslSample() failed, error: %s", ErrorToString(error));
     }
     return error;
 }
 #endif
 
-void SubMac::HandleReceiveDone(RxFrame *aFrame, otError aError)
+void SubMac::HandleReceiveDone(RxFrame *aFrame, Error aError)
 {
-    if (mPcapCallback && (aFrame != nullptr) && (aError == OT_ERROR_NONE))
+    if (mPcapCallback && (aFrame != nullptr) && (aError == kErrorNone))
     {
         mPcapCallback(aFrame, false, mPcapCallbackContext);
     }
@@ -262,7 +262,7 @@ void SubMac::HandleReceiveDone(RxFrame *aFrame, otError aError)
     }
 
 #if OPENTHREAD_CONFIG_MAC_CSL_DEBUG_ENABLE
-    if (aFrame != nullptr && aError == OT_ERROR_NONE)
+    if (aFrame != nullptr && aError == kErrorNone)
     {
         // Split the log into two lines for RTT to output
         otLogDebgMac("Received frame in state (SubMac %s, CSL %s), timestamp %u", StateToString(mState),
@@ -275,9 +275,9 @@ void SubMac::HandleReceiveDone(RxFrame *aFrame, otError aError)
     mCallbacks.ReceiveDone(aFrame, aError);
 }
 
-otError SubMac::Send(void)
+Error SubMac::Send(void)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     switch (mState)
     {
@@ -288,7 +288,7 @@ otError SubMac::Send(void)
 #endif
     case kStateTransmit:
     case kStateEnergyScan:
-        ExitNow(error = OT_ERROR_INVALID_STATE);
+        ExitNow(error = kErrorInvalidState);
         OT_UNREACHABLE_CODE(break);
 
     case kStateSleep:
@@ -409,7 +409,7 @@ exit:
 
 void SubMac::BeginTransmit(void)
 {
-    otError error;
+    Error error;
 
     OT_UNUSED_VARIABLE(error);
 
@@ -422,7 +422,7 @@ void SubMac::BeginTransmit(void)
     if ((mRadioCaps & OT_RADIO_CAPS_SLEEP_TO_TX) == 0)
     {
         error = Get<Radio>().Receive(mTransmitFrame.GetChannel());
-        OT_ASSERT(error == OT_ERROR_NONE);
+        OT_ASSERT(error == kErrorNone);
     }
 
     SetState(kStateTransmit);
@@ -433,14 +433,14 @@ void SubMac::BeginTransmit(void)
     }
 
     error = Get<Radio>().Transmit(mTransmitFrame);
-    if (error == OT_ERROR_INVALID_STATE && mTransmitFrame.mInfo.mTxInfo.mTxDelay > 0)
+    if (error == kErrorInvalidState && mTransmitFrame.mInfo.mTxInfo.mTxDelay > 0)
     {
         // Platform `transmit_at` fails and we send the frame directly.
         mTransmitFrame.mInfo.mTxInfo.mTxDelay         = 0;
         mTransmitFrame.mInfo.mTxInfo.mTxDelayBaseTime = 0;
         error                                         = Get<Radio>().Transmit(mTransmitFrame);
     }
-    OT_ASSERT(error == OT_ERROR_NONE);
+    OT_ASSERT(error == kErrorNone);
 
 exit:
     return;
@@ -458,7 +458,7 @@ void SubMac::HandleTransmitStarted(TxFrame &aFrame)
     }
 }
 
-void SubMac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError)
+void SubMac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError)
 {
     bool ccaSuccess = true;
     bool shouldRetx;
@@ -471,18 +471,18 @@ void SubMac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aEr
 
     switch (aError)
     {
-    case OT_ERROR_ABORT:
+    case kErrorAbort:
         // Do not record CCA status in case of `ABORT` error
         // since there may be no CCA check performed by radio.
         break;
 
-    case OT_ERROR_CHANNEL_ACCESS_FAILURE:
+    case kErrorChannelAccessFailure:
         ccaSuccess = false;
 
         OT_FALL_THROUGH;
 
-    case OT_ERROR_NONE:
+    case kErrorNone:
-    case OT_ERROR_NO_ACK:
+    case kErrorNoAck:
         if (aFrame.IsCsmaCaEnabled())
         {
             mCallbacks.RecordCcaStatus(ccaSuccess, aFrame.GetChannel());
@@ -510,8 +510,7 @@ void SubMac::HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aEr
 
     // Determine whether to re-transmit the frame.
 
-    shouldRetx =
+    shouldRetx = ((aError != kErrorNone) && ShouldHandleRetries() && (mTransmitRetries < aFrame.GetMaxFrameRetries()));
-        ((aError != OT_ERROR_NONE) && ShouldHandleRetries() && (mTransmitRetries < aFrame.GetMaxFrameRetries()));
 
     mCallbacks.RecordFrameTransmitStatus(aFrame, aAckFrame, aError, mTransmitRetries, shouldRetx);
 
@@ -554,10 +553,10 @@ void SubMac::UpdateFrameCounterOnTxDone(const TxFrame &aFrame)
     allowError = Get<LinkRaw>().IsEnabled();
 #endif
 
-    VerifyOrExit(aFrame.GetKeyIdMode(keyIdMode) == OT_ERROR_NONE, OT_ASSERT(allowError));
+    VerifyOrExit(aFrame.GetKeyIdMode(keyIdMode) == kErrorNone, OT_ASSERT(allowError));
     VerifyOrExit(keyIdMode == Frame::kKeyIdMode1);
 
-    VerifyOrExit(aFrame.GetFrameCounter(frameCounter) == OT_ERROR_NONE, OT_ASSERT(allowError));
+    VerifyOrExit(aFrame.GetFrameCounter(frameCounter) == kErrorNone, OT_ASSERT(allowError));
     UpdateFrameCounter(frameCounter);
 
 exit:
@@ -574,9 +573,9 @@ int8_t SubMac::GetNoiseFloor(void)
     return Get<Radio>().GetReceiveSensitivity();
 }
 
-otError SubMac::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
+Error SubMac::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     switch (mState)
     {
@@ -587,7 +586,7 @@ otError SubMac::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
     case kStateCslTransmit:
 #endif
     case kStateEnergyScan:
-        ExitNow(error = OT_ERROR_INVALID_STATE);
+        ExitNow(error = kErrorInvalidState);
 
     case kStateReceive:
     case kStateSleep:
@@ -605,7 +604,7 @@ otError SubMac::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
     else if (ShouldHandleEnergyScan())
     {
         error = Get<Radio>().Receive(aScanChannel);
-        OT_ASSERT(error == OT_ERROR_NONE);
+        OT_ASSERT(error == kErrorNone);
 
         SetState(kStateEnergyScan);
         mEnergyScanMaxRssi = kInvalidRssiValue;
@@ -614,7 +613,7 @@ otError SubMac::EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration)
     }
     else
     {
-        error = OT_ERROR_NOT_IMPLEMENTED;
+        error = kErrorNotImplemented;
     }
 
 exit:
@@ -676,7 +675,7 @@ void SubMac::HandleTimer(void)
     case kStateTransmit:
         otLogDebgMac("Ack timer timed out");
         IgnoreError(Get<Radio>().Receive(mTransmitFrame.GetChannel()));
-        HandleTransmitDone(mTransmitFrame, nullptr, OT_ERROR_NO_ACK);
+        HandleTransmitDone(mTransmitFrame, nullptr, kErrorNoAck);
         break;
 
     case kStateEnergyScan:

src/core/mac/sub_mac.hpp

@@ -116,12 +116,12 @@ public:
          * This method notifies user of `SubMac` of a received frame.
          *
          * @param[in]  aFrame    A pointer to the received frame or nullptr if the receive operation failed.
-         * @param[in]  aError    OT_ERROR_NONE when successfully received a frame,
+         * @param[in]  aError    kErrorNone when successfully received a frame,
-         *                       OT_ERROR_ABORT when reception was aborted and a frame was not received,
+         *                       kErrorAbort when reception was aborted and a frame was not received,
-         *                       OT_ERROR_NO_BUFS when a frame could not be received due to lack of rx buffer space.
+         *                       kErrorNoBufs when a frame could not be received due to lack of rx buffer space.
          *
          */
-        void ReceiveDone(RxFrame *aFrame, otError aError);
+        void ReceiveDone(RxFrame *aFrame, Error aError);
 
         /**
          * This method notifies user of `SubMac` of CCA status (success/failure) for a frame transmission attempt.
@@ -144,10 +144,10 @@ public:
          *
          * @param[in] aFrame      The transmitted frame.
          * @param[in] aAckFrame   A pointer to the ACK frame, or nullptr if no ACK was received.
-         * @param[in] aError      OT_ERROR_NONE when the frame was transmitted successfully,
+         * @param[in] aError      kErrorNone when the frame was transmitted successfully,
-         *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+         *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-         *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+         *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-         *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+         *                        kErrorAbort when transmission was aborted for other reasons.
          * @param[in] aRetryCount Current retry count. This is valid only when sub-mac handles frame re-transmissions.
          * @param[in] aWillRetx   Indicates whether frame will be retransmitted or not. This is applicable only
          *                        when there was an error in current transmission attempt.
@@ -155,7 +155,7 @@ public:
          */
         void RecordFrameTransmitStatus(const TxFrame &aFrame,
                                        const RxFrame *aAckFrame,
-                                       otError        aError,
+                                       Error          aError,
                                        uint8_t        aRetryCount,
                                        bool           aWillRetx);
 
@@ -165,13 +165,13 @@ public:
          *
          * @param[in]  aFrame     The transmitted frame.
          * @param[in]  aAckFrame  A pointer to the ACK frame, nullptr if no ACK was received.
-         * @param[in]  aError     OT_ERROR_NONE when the frame was transmitted,
+         * @param[in]  aError     kErrorNone when the frame was transmitted,
-         *                        OT_ERROR_NO_ACK when the frame was transmitted but no ACK was received,
+         *                        kErrorNoAck when the frame was transmitted but no ACK was received,
-         *                        OT_ERROR_CHANNEL_ACCESS_FAILURE tx failed due to activity on the channel,
+         *                        kErrorChannelAccessFailure tx failed due to activity on the channel,
-         *                        OT_ERROR_ABORT when transmission was aborted for other reasons.
+         *                        kErrorAbort when transmission was aborted for other reasons.
          *
          */
-        void TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError);
+        void TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError);
 
         /**
          * This method notifies user of `SubMac` that energy scan is complete.
@@ -275,29 +275,29 @@ public:
     /**
      * This method enables the radio.
      *
-     * @retval OT_ERROR_NONE     Successfully enabled.
+     * @retval kErrorNone     Successfully enabled.
-     * @retval OT_ERROR_FAILED   The radio could not be enabled.
+     * @retval kErrorFailed   The radio could not be enabled.
      *
      */
-    otError Enable(void);
+    Error Enable(void);
 
     /**
      * This method disables the radio.
      *
-     * @retval OT_ERROR_NONE     Successfully disabled the radio.
+     * @retval kErrorNone     Successfully disabled the radio.
      *
      */
-    otError Disable(void);
+    Error Disable(void);
 
     /**
      * This method transitions the radio to Sleep.
      *
-     * @retval OT_ERROR_NONE          Successfully transitioned to Sleep.
+     * @retval kErrorNone          Successfully transitioned to Sleep.
-     * @retval OT_ERROR_BUSY          The radio was transmitting.
+     * @retval kErrorBusy          The radio was transmitting.
-     * @retval OT_ERROR_INVALID_STATE The radio was disabled.
+     * @retval kErrorInvalidState  The radio was disabled.
      *
      */
-    otError Sleep(void);
+    Error Sleep(void);
 
     /**
      * This method indicates whether the sub-mac is busy transmitting or scanning.
@@ -313,11 +313,11 @@ public:
      *
      * @param[in]  aChannel   The channel to use for receiving.
      *
-     * @retval OT_ERROR_NONE          Successfully transitioned to Receive.
+     * @retval kErrorNone          Successfully transitioned to Receive.
-     * @retval OT_ERROR_INVALID_STATE The radio was disabled or transmitting.
+     * @retval kErrorInvalidState  The radio was disabled or transmitting.
      *
      */
-    otError Receive(uint8_t aChannel);
+    Error Receive(uint8_t aChannel);
 
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE
     /**
@@ -330,12 +330,12 @@ public:
      * @param[in]  aPanChannel  The current phy channel used by the device. This param will only take effect when CSL
      *                          channel hasn't been explicitly specified.
      *
-     * @retval OT_ERROR_NONE          Successfully entered CSL operation (sleep or receive according to CSL timer).
+     * @retval kErrorNone          Successfully entered CSL operation (sleep or receive according to CSL timer).
-     * @retval OT_ERROR_BUSY          The radio was transmitting.
+     * @retval kErrorBusy          The radio was transmitting.
-     * @retval OT_ERROR_INVALID_STATE The radio was disabled.
+     * @retval kErrorInvalidState  The radio was disabled.
      *
      */
-    otError CslSample(uint8_t aPanChannel);
+    Error CslSample(uint8_t aPanChannel);
 #endif
 
     /**
@@ -353,11 +353,11 @@ public:
      *
      * The `SubMac` layer handles Ack timeout, CSMA backoff, and frame retransmission.
      *
-     * @retval OT_ERROR_NONE          Successfully started the frame transmission
+     * @retval kErrorNone          Successfully started the frame transmission
-     * @retval OT_ERROR_INVALID_STATE The radio was disabled or transmitting.
+     * @retval kErrorInvalidState  The radio was disabled or transmitting.
      *
      */
-    otError Send(void);
+    Error Send(void);
 
     /**
      * This method gets the number of transmit retries of last transmitted frame.
@@ -381,12 +381,12 @@ public:
      * @param[in] aScanChannel   The channel to perform the energy scan on.
      * @param[in] aScanDuration  The duration, in milliseconds, for the channel to be scanned.
      *
-     * @retval OT_ERROR_NONE             Successfully started scanning the channel.
+     * @retval kErrorNone            Successfully started scanning the channel.
-     * @retval OT_ERROR_INVALID_STATE    The radio was disabled or transmitting.
+     * @retval kErrorInvalidState    The radio was disabled or transmitting.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  Energy scan is not supported (applicable in link-raw/radio mode only).
+     * @retval kErrorNotImplemented  Energy scan is not supported (applicable in link-raw/radio mode only).
      *
      */
-    otError EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration);
+    Error EnergyScan(uint8_t aScanChannel, uint16_t aScanDuration);
 
     /**
      * This method returns the noise floor value (currently use the radio receive sensitivity value).
@@ -596,9 +596,9 @@ private:
     void BeginTransmit(void);
     void SampleRssi(void);
 
-    void HandleReceiveDone(RxFrame *aFrame, otError aError);
+    void HandleReceiveDone(RxFrame *aFrame, Error aError);
     void HandleTransmitStarted(TxFrame &aFrame);
-    void HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError);
+    void HandleTransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError);
     void UpdateFrameCounterOnTxDone(const TxFrame &aFrame);
     void HandleEnergyScanDone(int8_t aMaxRssi);
 

src/core/mac/sub_mac_callbacks.cpp

@@ -51,7 +51,7 @@ SubMac::Callbacks::Callbacks(Instance &aInstance)
 
 #if OPENTHREAD_FTD || OPENTHREAD_MTD
 
-void SubMac::Callbacks::ReceiveDone(RxFrame *aFrame, otError aError)
+void SubMac::Callbacks::ReceiveDone(RxFrame *aFrame, Error aError)
 {
 #if OPENTHREAD_CONFIG_LINK_RAW_ENABLE
     if (Get<LinkRaw>().IsEnabled())
@@ -72,14 +72,14 @@ void SubMac::Callbacks::RecordCcaStatus(bool aCcaSuccess, uint8_t aChannel)
 
 void SubMac::Callbacks::RecordFrameTransmitStatus(const TxFrame &aFrame,
                                                   const RxFrame *aAckFrame,
-                                                  otError        aError,
+                                                  Error          aError,
                                                   uint8_t        aRetryCount,
                                                   bool           aWillRetx)
 {
     Get<Mac>().RecordFrameTransmitStatus(aFrame, aAckFrame, aError, aRetryCount, aWillRetx);
 }
 
-void SubMac::Callbacks::TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError)
+void SubMac::Callbacks::TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError)
 {
 #if OPENTHREAD_CONFIG_LINK_RAW_ENABLE
     if (Get<LinkRaw>().IsEnabled())
@@ -114,7 +114,7 @@ void SubMac::Callbacks::FrameCounterUpdated(uint32_t aFrameCounter)
 
 #elif OPENTHREAD_RADIO
 
-void SubMac::Callbacks::ReceiveDone(RxFrame *aFrame, otError aError)
+void SubMac::Callbacks::ReceiveDone(RxFrame *aFrame, Error aError)
 {
     Get<LinkRaw>().InvokeReceiveDone(aFrame, aError);
 }
@@ -125,14 +125,14 @@ void SubMac::Callbacks::RecordCcaStatus(bool, uint8_t)
 
 void SubMac::Callbacks::RecordFrameTransmitStatus(const TxFrame &aFrame,
                                                   const RxFrame *aAckFrame,
-                                                  otError        aError,
+                                                  Error          aError,
                                                   uint8_t        aRetryCount,
                                                   bool           aWillRetx)
 {
     Get<LinkRaw>().RecordFrameTransmitStatus(aFrame, aAckFrame, aError, aRetryCount, aWillRetx);
 }
 
-void SubMac::Callbacks::TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, otError aError)
+void SubMac::Callbacks::TransmitDone(TxFrame &aFrame, RxFrame *aAckFrame, Error aError)
 {
     Get<LinkRaw>().InvokeTransmitDone(aFrame, aAckFrame, aError);
 }

src/core/meshcop/announce_begin_client.cpp

@@ -53,18 +53,18 @@ AnnounceBeginClient::AnnounceBeginClient(Instance &aInstance)
 {
 }
 
-otError AnnounceBeginClient::SendRequest(uint32_t            aChannelMask,
+Error AnnounceBeginClient::SendRequest(uint32_t            aChannelMask,
-                                         uint8_t             aCount,
+                                       uint8_t             aCount,
-                                         uint16_t            aPeriod,
+                                       uint16_t            aPeriod,
-                                         const Ip6::Address &aAddress)
+                                       const Ip6::Address &aAddress)
 {
-    otError                 error = OT_ERROR_NONE;
+    Error                   error = kErrorNone;
     MeshCoP::ChannelMaskTlv channelMask;
     Ip6::MessageInfo        messageInfo;
     Coap::Message *         message = nullptr;
 
-    VerifyOrExit(Get<MeshCoP::Commissioner>().IsActive(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<MeshCoP::Commissioner>().IsActive(), error = kErrorInvalidState);
-    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsPost(aAddress, UriPath::kAnnounceBegin));
     SuccessOrExit(error = message->SetPayloadMarker());

src/core/meshcop/announce_begin_client.hpp

@@ -64,11 +64,11 @@ public:
      * @param[in]  aPeriod        The time between two successive MLE Announce transmissions (in milliseconds).
      * @param[in]  aAddress       The destination address.
      *
-     * @retval OT_ERROR_NONE     Successfully enqueued the Announce Begin message.
+     * @retval kErrorNone    Successfully enqueued the Announce Begin message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient buffers to generate a Announce Begin message.
+     * @retval kErrorNoBufs  Insufficient buffers to generate a Announce Begin message.
      *
      */
-    otError SendRequest(uint32_t aChannelMask, uint8_t aCount, uint16_t aPeriod, const Ip6::Address &aAddress);
+    Error SendRequest(uint32_t aChannelMask, uint8_t aCount, uint16_t aPeriod, const Ip6::Address &aAddress);
 };
 
 /**

src/core/meshcop/border_agent.cpp

@@ -62,7 +62,7 @@ void BorderAgent::ForwardContext::Init(Instance &           aInstance,
     memcpy(mToken, aMessage.GetToken(), mTokenLength);
 }
 
-otError BorderAgent::ForwardContext::ToHeader(Coap::Message &aMessage, uint8_t aCode)
+Error BorderAgent::ForwardContext::ToHeader(Coap::Message &aMessage, uint8_t aCode)
 {
     if ((mType == Coap::kTypeNonConfirmable) || mSeparate)
     {
@@ -81,17 +81,17 @@ otError BorderAgent::ForwardContext::ToHeader(Coap::Message &aMessage, uint8_t a
     return aMessage.SetToken(mToken, mTokenLength);
 }
 
-Coap::Message::Code BorderAgent::CoapCodeFromError(otError aError)
+Coap::Message::Code BorderAgent::CoapCodeFromError(Error aError)
 {
     Coap::Message::Code code;
 
     switch (aError)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         code = Coap::kCodeChanged;
         break;
 
-    case OT_ERROR_PARSE:
+    case kErrorParse:
         code = Coap::kCodeBadRequest;
         break;
 
@@ -103,13 +103,13 @@ Coap::Message::Code BorderAgent::CoapCodeFromError(otError aError)
     return code;
 }
 
-void BorderAgent::SendErrorMessage(ForwardContext &aForwardContext, otError aError)
+void BorderAgent::SendErrorMessage(ForwardContext &aForwardContext, Error aError)
 {
-    otError           error   = OT_ERROR_NONE;
+    Error             error   = kErrorNone;
     Coap::CoapSecure &coaps   = Get<Coap::CoapSecure>();
     Coap::Message *   message = nullptr;
 
-    VerifyOrExit((message = NewMeshCoPMessage(coaps)) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(coaps)) != nullptr, error = kErrorNoBufs);
     SuccessOrExit(error = aForwardContext.ToHeader(*message, CoapCodeFromError(aError)));
     SuccessOrExit(error = coaps.SendMessage(*message, coaps.GetMessageInfo()));
 
@@ -118,13 +118,13 @@ exit:
     LogError("send error CoAP message", error);
 }
 
-void BorderAgent::SendErrorMessage(const Coap::Message &aRequest, bool aSeparate, otError aError)
+void BorderAgent::SendErrorMessage(const Coap::Message &aRequest, bool aSeparate, Error aError)
 {
-    otError           error   = OT_ERROR_NONE;
+    Error             error   = kErrorNone;
     Coap::CoapSecure &coaps   = Get<Coap::CoapSecure>();
     Coap::Message *   message = nullptr;
 
-    VerifyOrExit((message = NewMeshCoPMessage(coaps)) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(coaps)) != nullptr, error = kErrorNoBufs);
 
     if (aRequest.IsNonConfirmable() || aSeparate)
     {
@@ -152,7 +152,7 @@ exit:
 void BorderAgent::HandleCoapResponse(void *               aContext,
                                      otMessage *          aMessage,
                                      const otMessageInfo *aMessageInfo,
-                                     otError              aResult)
+                                     Error                aResult)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
@@ -162,13 +162,13 @@ void BorderAgent::HandleCoapResponse(void *               aContext,
                                                          aResult);
 }
 
-void BorderAgent::HandleCoapResponse(ForwardContext &aForwardContext, const Coap::Message *aResponse, otError aResult)
+void BorderAgent::HandleCoapResponse(ForwardContext &aForwardContext, const Coap::Message *aResponse, Error aResult)
 {
     Coap::Message *message = nullptr;
-    otError        error;
+    Error          error;
 
     SuccessOrExit(error = aResult);
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = kErrorNoBufs);
 
     if (aForwardContext.IsPetition() && aResponse->GetCode() == Coap::kCodeChanged)
     {
@@ -199,12 +199,11 @@ void BorderAgent::HandleCoapResponse(ForwardContext &aForwardContext, const Coap
 
 exit:
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         FreeMessage(message);
 
-        otLogWarnMeshCoP("Commissioner request[%hu] failed: %s", aForwardContext.GetMessageId(),
+        otLogWarnMeshCoP("Commissioner request[%hu] failed: %s", aForwardContext.GetMessageId(), ErrorToString(error));
-                         otThreadErrorToString(error));
 
         SendErrorMessage(aForwardContext, error);
     }
@@ -316,13 +315,13 @@ void BorderAgent::HandleProxyTransmit(const Coap::Message &aMessage)
     Message *           message = nullptr;
     Ip6::MessageInfo    messageInfo;
     uint16_t            offset;
-    otError             error;
+    Error               error;
     UdpEncapsulationTlv tlv;
 
     SuccessOrExit(error = Tlv::FindTlvOffset(aMessage, Tlv::kUdpEncapsulation, offset));
     SuccessOrExit(error = aMessage.Read(offset, tlv));
 
-    VerifyOrExit((message = Get<Ip6::Udp>().NewMessage(0)) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = Get<Ip6::Udp>().NewMessage(0)) != nullptr, error = kErrorNoBufs);
     SuccessOrExit(error = message->SetLength(tlv.GetUdpLength()));
     aMessage.CopyTo(offset + sizeof(tlv), 0, tlv.GetUdpLength(), *message);
 
@@ -342,15 +341,15 @@ exit:
 
 bool BorderAgent::HandleUdpReceive(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError        error;
+    Error          error;
     Coap::Message *message = nullptr;
 
     VerifyOrExit(aMessageInfo.GetSockAddr() == mCommissionerAloc.GetAddress(),
-                 error = OT_ERROR_DESTINATION_ADDRESS_FILTERED);
+                 error = kErrorDestinationAddressFiltered);
 
-    VerifyOrExit(aMessage.GetLength() > 0, error = OT_ERROR_NONE);
+    VerifyOrExit(aMessage.GetLength() > 0, error = kErrorNone);
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = kErrorNoBufs);
 
     message->InitAsNonConfirmablePost();
     SuccessOrExit(error = message->AppendUriPathOptions(UriPath::kProxyRx));
@@ -382,16 +381,16 @@ exit:
     FreeMessageOnError(message, error);
     LogError("notify commissioner on ProxyRx (c/ur)", error);
 
-    return error != OT_ERROR_DESTINATION_ADDRESS_FILTERED;
+    return error != kErrorDestinationAddressFiltered;
 }
 
 void BorderAgent::HandleRelayReceive(const Coap::Message &aMessage)
 {
     Coap::Message *message = nullptr;
-    otError        error;
+    Error          error;
 
-    VerifyOrExit(aMessage.IsNonConfirmablePostRequest(), error = OT_ERROR_DROP);
+    VerifyOrExit(aMessage.IsNonConfirmablePostRequest(), error = kErrorDrop);
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = kErrorNoBufs);
 
     message->InitAsNonConfirmablePost();
     SuccessOrExit(error = message->AppendUriPathOptions(UriPath::kRelayRx));
@@ -408,9 +407,9 @@ exit:
     FreeMessageOnError(message, error);
 }
 
-otError BorderAgent::ForwardToCommissioner(Coap::Message &aForwardMessage, const Message &aMessage)
+Error BorderAgent::ForwardToCommissioner(Coap::Message &aForwardMessage, const Message &aMessage)
 {
-    otError  error  = OT_ERROR_NONE;
+    Error    error  = kErrorNone;
     uint16_t offset = 0;
 
     offset = aForwardMessage.GetLength();
@@ -429,11 +428,11 @@ exit:
 
 void BorderAgent::HandleKeepAlive(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
-    otError error;
+    Error error;
 
     error = ForwardToLeader(aMessage, aMessageInfo, UriPath::kLeaderKeepAlive, false, true);
 
-    if (error == OT_ERROR_NONE)
+    if (error == kErrorNone)
     {
         mTimer.Start(kKeepAliveTimeout);
     }
@@ -441,7 +440,7 @@ void BorderAgent::HandleKeepAlive(const Coap::Message &aMessage, const Ip6::Mess
 
 void BorderAgent::HandleRelayTransmit(const Coap::Message &aMessage)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     uint16_t         joinerRouterRloc;
     Coap::Message *  message = nullptr;
     Ip6::MessageInfo messageInfo;
@@ -451,7 +450,7 @@ void BorderAgent::HandleRelayTransmit(const Coap::Message &aMessage)
 
     SuccessOrExit(error = Tlv::Find<JoinerRouterLocatorTlv>(aMessage, joinerRouterRloc));
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsNonConfirmablePost(UriPath::kRelayTx));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -475,19 +474,19 @@ exit:
     LogError("send to joiner router request RelayTx (c/tx)", error);
 }
 
-otError BorderAgent::ForwardToLeader(const Coap::Message &   aMessage,
+Error BorderAgent::ForwardToLeader(const Coap::Message &   aMessage,
-                                     const Ip6::MessageInfo &aMessageInfo,
+                                   const Ip6::MessageInfo &aMessageInfo,
-                                     const char *            aPath,
+                                   const char *            aPath,
-                                     bool                    aPetition,
+                                   bool                    aPetition,
-                                     bool                    aSeparate)
+                                   bool                    aSeparate)
 {
-    otError          error          = OT_ERROR_NONE;
+    Error            error          = kErrorNone;
     ForwardContext * forwardContext = nullptr;
     Ip6::MessageInfo messageInfo;
     Coap::Message *  message = nullptr;
     uint16_t         offset  = 0;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     if (aSeparate)
     {
@@ -495,7 +494,7 @@ otError BorderAgent::ForwardToLeader(const Coap::Message &   aMessage,
     }
 
     forwardContext = static_cast<ForwardContext *>(Instance::HeapCAlloc(1, sizeof(ForwardContext)));
-    VerifyOrExit(forwardContext != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(forwardContext != nullptr, error = kErrorNoBufs);
 
     forwardContext->Init(GetInstance(), aMessage, aPetition, aSeparate);
 
@@ -526,7 +525,7 @@ otError BorderAgent::ForwardToLeader(const Coap::Message &   aMessage,
 exit:
     LogError("forward to leader", error);
 
-    if (error != OT_ERROR_NONE)
+    if (error != kErrorNone)
     {
         if (forwardContext != nullptr)
         {
@@ -562,12 +561,12 @@ void BorderAgent::HandleConnected(bool aConnected)
     }
 }
 
-otError BorderAgent::Start(void)
+Error BorderAgent::Start(void)
 {
-    otError           error;
+    Error             error;
     Coap::CoapSecure &coaps = Get<Coap::CoapSecure>();
 
-    VerifyOrExit(mState == kStateStopped, error = OT_ERROR_ALREADY);
+    VerifyOrExit(mState == kStateStopped, error = kErrorAlready);
 
     SuccessOrExit(error = coaps.Start(kBorderAgentUdpPort));
     SuccessOrExit(error = coaps.SetPsk(Get<KeyManager>().GetPskc().m8, OT_PSKC_MAX_SIZE));
@@ -606,12 +605,12 @@ void BorderAgent::HandleTimeout(void)
     }
 }
 
-otError BorderAgent::Stop(void)
+Error BorderAgent::Stop(void)
 {
-    otError           error = OT_ERROR_NONE;
+    Error             error = kErrorNone;
     Coap::CoapSecure &coaps = Get<Coap::CoapSecure>();
 
-    VerifyOrExit(mState != kStateStopped, error = OT_ERROR_ALREADY);
+    VerifyOrExit(mState != kStateStopped, error = kErrorAlready);
 
     mTimer.Stop();
 

src/core/meshcop/border_agent.hpp

@@ -75,20 +75,20 @@ public:
     /**
      * This method starts the Border Agent service.
      *
-     * @retval OT_ERROR_NONE    Successfully started the Border Agent service.
+     * @retval kErrorNone    Successfully started the Border Agent service.
-     * @retval OT_ERROR_ALREADY Border Agent is already started.
+     * @retval kErrorAlready Border Agent is already started.
      *
      */
-    otError Start(void);
+    Error Start(void);
 
     /**
      * This method stops the Border Agent service.
      *
-     * @retval OT_ERROR_NONE    Successfully stopped the Border Agent service.
+     * @retval kErrorNone    Successfully stopped the Border Agent service.
-     * @retval OT_ERROR_ALREADY Border Agent is already stopped.
+     * @retval kErrorAlready Border Agent is already stopped.
      *
      */
-    otError Stop(void);
+    Error Stop(void);
 
     /**
      * This method gets the state of the Border Agent service.
@@ -111,7 +111,7 @@ private:
         void     Init(Instance &aInstance, const Coap::Message &aMessage, bool aPetition, bool aSeparate);
         bool     IsPetition(void) const { return mPetition; }
         uint16_t GetMessageId(void) const { return mMessageId; }
-        otError  ToHeader(Coap::Message &aMessage, uint8_t aCode);
+        Error    ToHeader(Coap::Message &aMessage, uint8_t aCode);
 
     private:
         uint16_t mMessageId;                             // The CoAP Message ID of the original request.
@@ -124,9 +124,9 @@ private:
 
     void HandleNotifierEvents(Events aEvents);
 
-    Coap::Message::Code CoapCodeFromError(otError aError);
+    Coap::Message::Code CoapCodeFromError(Error aError);
-    void                SendErrorMessage(ForwardContext &aForwardContext, otError aError);
+    void                SendErrorMessage(ForwardContext &aForwardContext, Error aError);
-    void                SendErrorMessage(const Coap::Message &aRequest, bool aSeparate, otError aError);
+    void                SendErrorMessage(const Coap::Message &aRequest, bool aSeparate, Error aError);
 
     static void HandleConnected(bool aConnected, void *aContext);
     void        HandleConnected(bool aConnected);
@@ -140,15 +140,15 @@ private:
     static void HandleCoapResponse(void *               aContext,
                                    otMessage *          aMessage,
                                    const otMessageInfo *aMessageInfo,
-                                   otError              aResult);
+                                   Error                aResult);
-    void        HandleCoapResponse(ForwardContext &aForwardContext, const Coap::Message *aResponse, otError aResult);
+    void        HandleCoapResponse(ForwardContext &aForwardContext, const Coap::Message *aResponse, Error aResult);
 
-    otError     ForwardToLeader(const Coap::Message &   aMessage,
+    Error       ForwardToLeader(const Coap::Message &   aMessage,
                                 const Ip6::MessageInfo &aMessageInfo,
                                 const char *            aPath,
                                 bool                    aPetition,
                                 bool                    aSeparate);
-    otError     ForwardToCommissioner(Coap::Message &aForwardMessage, const Message &aMessage);
+    Error       ForwardToCommissioner(Coap::Message &aForwardMessage, const Message &aMessage);
     void        HandleKeepAlive(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
     void        HandleRelayTransmit(const Coap::Message &aMessage);
     void        HandleRelayReceive(const Coap::Message &aMessage);

src/core/meshcop/commissioner.cpp

@@ -294,18 +294,18 @@ void Commissioner::RemoveJoinerEntry(Commissioner::Joiner &aJoiner)
     SignalJoinerEvent(kJoinerEventRemoved, &joinerCopy);
 }
 
-otError Commissioner::Start(otCommissionerStateCallback  aStateCallback,
+Error Commissioner::Start(otCommissionerStateCallback  aStateCallback,
-                            otCommissionerJoinerCallback aJoinerCallback,
+                          otCommissionerJoinerCallback aJoinerCallback,
-                            void *                       aCallbackContext)
+                          void *                       aCallbackContext)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
-    VerifyOrExit(Get<Mle::MleRouter>().IsAttached(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<Mle::MleRouter>().IsAttached(), error = kErrorInvalidState);
-    VerifyOrExit(mState == kStateDisabled, error = OT_ERROR_ALREADY);
+    VerifyOrExit(mState == kStateDisabled, error = kErrorAlready);
 
 #if OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE
     error = Get<MeshCoP::BorderAgent>().Stop();
-    VerifyOrExit(error == OT_ERROR_NONE || error == OT_ERROR_ALREADY);
+    VerifyOrExit(error == kErrorNone || error == kErrorAlready);
 #endif
 
     SuccessOrExit(error = Get<Coap::CoapSecure>().Start(SendRelayTransmit, this));
@@ -320,7 +320,7 @@ otError Commissioner::Start(otCommissionerStateCallback  aStateCallback,
     SetState(kStatePetition);
 
 exit:
-    if ((error != OT_ERROR_NONE) && (error != OT_ERROR_ALREADY))
+    if ((error != kErrorNone) && (error != kErrorAlready))
     {
         Get<Coap::CoapSecure>().Stop();
     }
@@ -329,12 +329,12 @@ exit:
     return error;
 }
 
-otError Commissioner::Stop(bool aResign)
+Error Commissioner::Stop(bool aResign)
 {
-    otError error      = OT_ERROR_NONE;
+    Error error      = kErrorNone;
-    bool    needResign = false;
+    bool  needResign = false;
 
-    VerifyOrExit(mState != kStateDisabled, error = OT_ERROR_ALREADY);
+    VerifyOrExit(mState != kStateDisabled, error = kErrorAlready);
 
     Get<Coap::CoapSecure>().Stop();
 
@@ -398,10 +398,10 @@ exit:
 
 void Commissioner::SendCommissionerSet(void)
 {
-    otError                error = OT_ERROR_NONE;
+    Error                  error = kErrorNone;
     otCommissioningDataset dataset;
 
-    VerifyOrExit(mState == kStateActive, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mState == kStateActive, error = kErrorInvalidState);
 
     memset(&dataset, 0, sizeof(dataset));
 
@@ -427,19 +427,19 @@ void Commissioner::ClearJoiners(void)
     SendCommissionerSet();
 }
 
-otError Commissioner::AddJoiner(const Mac::ExtAddress *aEui64,
+Error Commissioner::AddJoiner(const Mac::ExtAddress *aEui64,
-                                const JoinerDiscerner *aDiscerner,
+                              const JoinerDiscerner *aDiscerner,
-                                const char *           aPskd,
+                              const char *           aPskd,
-                                uint32_t               aTimeout)
+                              uint32_t               aTimeout)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     Joiner *joiner;
 
-    VerifyOrExit(mState == kStateActive, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mState == kStateActive, error = kErrorInvalidState);
 
     if (aDiscerner != nullptr)
     {
-        VerifyOrExit(aDiscerner->IsValid(), error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(aDiscerner->IsValid(), error = kErrorInvalidArgs);
         joiner = FindJoinerEntry(*aDiscerner);
     }
     else
@@ -452,7 +452,7 @@ otError Commissioner::AddJoiner(const Mac::ExtAddress *aEui64,
         joiner = GetUnusedJoinerEntry();
     }
 
-    VerifyOrExit(joiner != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(joiner != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = joiner->mPskd.SetFrom(aPskd));
 
@@ -514,9 +514,9 @@ exit:
     return;
 }
 
-otError Commissioner::GetNextJoinerInfo(uint16_t &aIterator, otJoinerInfo &aJoinerInfo) const
+Error Commissioner::GetNextJoinerInfo(uint16_t &aIterator, otJoinerInfo &aJoinerInfo) const
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     while (aIterator < OT_ARRAY_LENGTH(mJoiners))
     {
@@ -529,22 +529,22 @@ otError Commissioner::GetNextJoinerInfo(uint16_t &aIterator, otJoinerInfo &aJoin
         }
     }
 
-    error = OT_ERROR_NOT_FOUND;
+    error = kErrorNotFound;
 
 exit:
     return error;
 }
 
-otError Commissioner::RemoveJoiner(const Mac::ExtAddress *aEui64, const JoinerDiscerner *aDiscerner, uint32_t aDelay)
+Error Commissioner::RemoveJoiner(const Mac::ExtAddress *aEui64, const JoinerDiscerner *aDiscerner, uint32_t aDelay)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     Joiner *joiner;
 
-    VerifyOrExit(mState == kStateActive, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mState == kStateActive, error = kErrorInvalidState);
 
     if (aDiscerner != nullptr)
     {
-        VerifyOrExit(aDiscerner->IsValid(), error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(aDiscerner->IsValid(), error = kErrorInvalidArgs);
         joiner = FindJoinerEntry(*aDiscerner);
     }
     else
@@ -552,7 +552,7 @@ otError Commissioner::RemoveJoiner(const Mac::ExtAddress *aEui64, const JoinerDi
         joiner = FindJoinerEntry(aEui64);
     }
 
-    VerifyOrExit(joiner != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(joiner != nullptr, error = kErrorNotFound);
 
     RemoveJoiner(*joiner, aDelay);
 
@@ -578,9 +578,9 @@ void Commissioner::RemoveJoiner(Joiner &aJoiner, uint32_t aDelay)
     }
 }
 
-otError Commissioner::SetProvisioningUrl(const char *aProvisioningUrl)
+Error Commissioner::SetProvisioningUrl(const char *aProvisioningUrl)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     uint8_t len;
 
     if (aProvisioningUrl == nullptr)
@@ -589,11 +589,11 @@ otError Commissioner::SetProvisioningUrl(const char *aProvisioningUrl)
         ExitNow();
     }
 
-    VerifyOrExit(IsValidUtf8String(aProvisioningUrl), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(IsValidUtf8String(aProvisioningUrl), error = kErrorInvalidArgs);
 
     len = static_cast<uint8_t>(StringLength(aProvisioningUrl, sizeof(mProvisioningUrl)));
 
-    VerifyOrExit(len < sizeof(mProvisioningUrl), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(len < sizeof(mProvisioningUrl), error = kErrorInvalidArgs);
 
     memcpy(mProvisioningUrl, aProvisioningUrl, len);
     mProvisioningUrl[len] = '\0';
@@ -682,14 +682,14 @@ void Commissioner::UpdateJoinerExpirationTimer(void)
     }
 }
 
-otError Commissioner::SendMgmtCommissionerGetRequest(const uint8_t *aTlvs, uint8_t aLength)
+Error Commissioner::SendMgmtCommissionerGetRequest(const uint8_t *aTlvs, uint8_t aLength)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Coap::Message *  message;
     Ip6::MessageInfo messageInfo;
     MeshCoP::Tlv     tlv;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsConfirmablePost(UriPath::kCommissionerGet));
 
@@ -722,7 +722,7 @@ exit:
 void Commissioner::HandleMgmtCommissionerGetResponse(void *               aContext,
                                                      otMessage *          aMessage,
                                                      const otMessageInfo *aMessageInfo,
-                                                     otError              aResult)
+                                                     Error                aResult)
 {
     static_cast<Commissioner *>(aContext)->HandleMgmtCommissionerGetResponse(
         static_cast<Coap::Message *>(aMessage), static_cast<const Ip6::MessageInfo *>(aMessageInfo), aResult);
@@ -730,26 +730,26 @@ void Commissioner::HandleMgmtCommissionerGetResponse(void *               aConte
 
 void Commissioner::HandleMgmtCommissionerGetResponse(Coap::Message *         aMessage,
                                                      const Ip6::MessageInfo *aMessageInfo,
-                                                     otError                 aResult)
+                                                     Error                   aResult)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
-    VerifyOrExit(aResult == OT_ERROR_NONE && aMessage->GetCode() == Coap::kCodeChanged);
+    VerifyOrExit(aResult == kErrorNone && aMessage->GetCode() == Coap::kCodeChanged);
     otLogInfoMeshCoP("received MGMT_COMMISSIONER_GET response");
 
 exit:
     return;
 }
 
-otError Commissioner::SendMgmtCommissionerSetRequest(const otCommissioningDataset &aDataset,
+Error Commissioner::SendMgmtCommissionerSetRequest(const otCommissioningDataset &aDataset,
-                                                     const uint8_t *               aTlvs,
+                                                   const uint8_t *               aTlvs,
-                                                     uint8_t                       aLength)
+                                                   uint8_t                       aLength)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Coap::Message *  message;
     Ip6::MessageInfo messageInfo;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsConfirmablePost(UriPath::kCommissionerSet));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -802,7 +802,7 @@ exit:
 void Commissioner::HandleMgmtCommissionerSetResponse(void *               aContext,
                                                      otMessage *          aMessage,
                                                      const otMessageInfo *aMessageInfo,
-                                                     otError              aResult)
+                                                     Error                aResult)
 {
     static_cast<Commissioner *>(aContext)->HandleMgmtCommissionerSetResponse(
         static_cast<Coap::Message *>(aMessage), static_cast<const Ip6::MessageInfo *>(aMessageInfo), aResult);
@@ -810,27 +810,27 @@ void Commissioner::HandleMgmtCommissionerSetResponse(void *               aConte
 
 void Commissioner::HandleMgmtCommissionerSetResponse(Coap::Message *         aMessage,
                                                      const Ip6::MessageInfo *aMessageInfo,
-                                                     otError                 aResult)
+                                                     Error                   aResult)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
-    VerifyOrExit(aResult == OT_ERROR_NONE && aMessage->GetCode() == Coap::kCodeChanged);
+    VerifyOrExit(aResult == kErrorNone && aMessage->GetCode() == Coap::kCodeChanged);
     otLogInfoMeshCoP("received MGMT_COMMISSIONER_SET response");
 
 exit:
     return;
 }
 
-otError Commissioner::SendPetition(void)
+Error Commissioner::SendPetition(void)
 {
-    otError           error   = OT_ERROR_NONE;
+    Error             error   = kErrorNone;
     Coap::Message *   message = nullptr;
     Ip6::MessageInfo  messageInfo;
     CommissionerIdTlv commissionerId;
 
     mTransmitAttempts++;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsConfirmablePost(UriPath::kLeaderPetition));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -856,7 +856,7 @@ exit:
 void Commissioner::HandleLeaderPetitionResponse(void *               aContext,
                                                 otMessage *          aMessage,
                                                 const otMessageInfo *aMessageInfo,
-                                                otError              aResult)
+                                                Error                aResult)
 {
     static_cast<Commissioner *>(aContext)->HandleLeaderPetitionResponse(
         static_cast<Coap::Message *>(aMessage), static_cast<const Ip6::MessageInfo *>(aMessageInfo), aResult);
@@ -864,7 +864,7 @@ void Commissioner::HandleLeaderPetitionResponse(void *               aContext,
 
 void Commissioner::HandleLeaderPetitionResponse(Coap::Message *         aMessage,
                                                 const Ip6::MessageInfo *aMessageInfo,
-                                                otError                 aResult)
+                                                Error                   aResult)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
@@ -872,7 +872,7 @@ void Commissioner::HandleLeaderPetitionResponse(Coap::Message *         aMessage
     bool    retransmit = false;
 
     VerifyOrExit(mState != kStateActive);
-    VerifyOrExit(aResult == OT_ERROR_NONE && aMessage->GetCode() == Coap::kCodeChanged,
+    VerifyOrExit(aResult == kErrorNone && aMessage->GetCode() == Coap::kCodeChanged,
                  retransmit = (mState == kStatePetition));
 
     otLogInfoMeshCoP("received Leader Petition response");
@@ -921,11 +921,11 @@ void Commissioner::SendKeepAlive(void)
 
 void Commissioner::SendKeepAlive(uint16_t aSessionId)
 {
-    otError          error   = OT_ERROR_NONE;
+    Error            error   = kErrorNone;
     Coap::Message *  message = nullptr;
     Ip6::MessageInfo messageInfo;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->InitAsConfirmablePost(UriPath::kLeaderKeepAlive));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -951,7 +951,7 @@ exit:
 void Commissioner::HandleLeaderKeepAliveResponse(void *               aContext,
                                                  otMessage *          aMessage,
                                                  const otMessageInfo *aMessageInfo,
-                                                 otError              aResult)
+                                                 Error                aResult)
 {
     static_cast<Commissioner *>(aContext)->HandleLeaderKeepAliveResponse(
         static_cast<Coap::Message *>(aMessage), static_cast<const Ip6::MessageInfo *>(aMessageInfo), aResult);
@@ -959,14 +959,14 @@ void Commissioner::HandleLeaderKeepAliveResponse(void *               aContext,
 
 void Commissioner::HandleLeaderKeepAliveResponse(Coap::Message *         aMessage,
                                                  const Ip6::MessageInfo *aMessageInfo,
-                                                 otError                 aResult)
+                                                 Error                   aResult)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
     uint8_t state;
 
     VerifyOrExit(mState == kStateActive);
-    VerifyOrExit(aResult == OT_ERROR_NONE && aMessage->GetCode() == Coap::kCodeChanged,
+    VerifyOrExit(aResult == kErrorNone && aMessage->GetCode() == Coap::kCodeChanged,
                  IgnoreError(Stop(/* aResign */ false)));
 
     otLogInfoMeshCoP("received Leader keep-alive response");
@@ -990,7 +990,7 @@ void Commissioner::HandleRelayReceive(Coap::Message &aMessage, const Ip6::Messag
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
-    otError                  error;
+    Error                    error;
     uint16_t                 joinerPort;
     Ip6::InterfaceIdentifier joinerIid;
     uint16_t                 joinerRloc;
@@ -998,7 +998,7 @@ void Commissioner::HandleRelayReceive(Coap::Message &aMessage, const Ip6::Messag
     uint16_t                 offset;
     uint16_t                 length;
 
-    VerifyOrExit(mState == kStateActive, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mState == kStateActive, error = kErrorInvalidState);
 
     VerifyOrExit(aMessage.IsNonConfirmablePostRequest());
 
@@ -1007,7 +1007,7 @@ void Commissioner::HandleRelayReceive(Coap::Message &aMessage, const Ip6::Messag
     SuccessOrExit(error = Tlv::Find<JoinerRouterLocatorTlv>(aMessage, joinerRloc));
 
     SuccessOrExit(error = Tlv::FindTlvValueOffset(aMessage, Tlv::kJoinerDtlsEncapsulation, offset, length));
-    VerifyOrExit(length <= aMessage.GetLength() - offset, error = OT_ERROR_PARSE);
+    VerifyOrExit(length <= aMessage.GetLength() - offset, error = kErrorParse);
 
     if (!Get<Coap::CoapSecure>().IsConnectionActive())
     {
@@ -1084,7 +1084,7 @@ void Commissioner::HandleJoinerFinalize(Coap::Message &aMessage, const Ip6::Mess
 
     otLogInfoMeshCoP("received joiner finalize");
 
-    if (Tlv::FindTlv(aMessage, provisioningUrl) == OT_ERROR_NONE)
+    if (Tlv::FindTlv(aMessage, provisioningUrl) == kErrorNone)
     {
         uint8_t len = static_cast<uint8_t>(StringLength(mProvisioningUrl, sizeof(mProvisioningUrl)));
 
@@ -1111,11 +1111,11 @@ void Commissioner::HandleJoinerFinalize(Coap::Message &aMessage, const Ip6::Mess
 
 void Commissioner::SendJoinFinalizeResponse(const Coap::Message &aRequest, StateTlv::State aState)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Ip6::MessageInfo joinerMessageInfo;
     Coap::Message *  message;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Coap::CoapSecure>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->SetDefaultResponseHeader(aRequest));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -1152,22 +1152,22 @@ exit:
     FreeMessageOnError(message, error);
 }
 
-otError Commissioner::SendRelayTransmit(void *aContext, Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error Commissioner::SendRelayTransmit(void *aContext, Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     return static_cast<Commissioner *>(aContext)->SendRelayTransmit(aMessage, aMessageInfo);
 }
 
-otError Commissioner::SendRelayTransmit(Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
+Error Commissioner::SendRelayTransmit(Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     OT_UNUSED_VARIABLE(aMessageInfo);
 
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     ExtendedTlv      tlv;
     Coap::Message *  message;
     uint16_t         offset;
     Ip6::MessageInfo messageInfo;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     message->InitAsNonConfirmablePost();
     SuccessOrExit(error = message->AppendUriPathOptions(UriPath::kRelayTx));

src/core/meshcop/commissioner.hpp

@@ -86,25 +86,25 @@ public:
      * @param[in]  aJoinerCallback   A pointer to a function that is called when a joiner event occurs.
      * @param[in]  aCallbackContext  A pointer to application-specific context.
      *
-     * @retval OT_ERROR_NONE           Successfully started the Commissioner service.
+     * @retval kErrorNone           Successfully started the Commissioner service.
-     * @retval OT_ERROR_ALREADY        Commissioner is already started.
+     * @retval kErrorAlready        Commissioner is already started.
-     * @retval OT_ERROR_INVALID_STATE  Device is not currently attached to a network.
+     * @retval kErrorInvalidState   Device is not currently attached to a network.
      *
      */
-    otError Start(otCommissionerStateCallback  aStateCallback,
+    Error Start(otCommissionerStateCallback  aStateCallback,
-                  otCommissionerJoinerCallback aJoinerCallback,
+                otCommissionerJoinerCallback aJoinerCallback,
-                  void *                       aCallbackContext);
+                void *                       aCallbackContext);
 
     /**
      * This method stops the Commissioner service.
      *
      * @param[in]  aResign      Whether send LEAD_KA.req to resign as Commissioner
      *
-     * @retval OT_ERROR_NONE     Successfully stopped the Commissioner service.
+     * @retval kErrorNone     Successfully stopped the Commissioner service.
-     * @retval OT_ERROR_ALREADY  Commissioner is already stopped.
+     * @retval kErrorAlready  Commissioner is already stopped.
      *
      */
-    otError Stop(bool aResign);
+    Error Stop(bool aResign);
 
     /**
      * This method clears all Joiner entries.
@@ -118,12 +118,12 @@ public:
      * @param[in]  aPskd         A pointer to the PSKd.
      * @param[in]  aTimeout      A time after which a Joiner is automatically removed, in seconds.
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NO_BUFS        No buffers available to add the Joiner.
+     * @retval kErrorNoBufs        No buffers available to add the Joiner.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError AddJoinerAny(const char *aPskd, uint32_t aTimeout) { return AddJoiner(nullptr, nullptr, aPskd, aTimeout); }
+    Error AddJoinerAny(const char *aPskd, uint32_t aTimeout) { return AddJoiner(nullptr, nullptr, aPskd, aTimeout); }
 
     /**
      * This method adds a Joiner entry.
@@ -132,12 +132,12 @@ public:
      * @param[in]  aPskd         A pointer to the PSKd.
      * @param[in]  aTimeout      A time after which a Joiner is automatically removed, in seconds.
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NO_BUFS        No buffers available to add the Joiner.
+     * @retval kErrorNoBufs        No buffers available to add the Joiner.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError AddJoiner(const Mac::ExtAddress &aEui64, const char *aPskd, uint32_t aTimeout)
+    Error AddJoiner(const Mac::ExtAddress &aEui64, const char *aPskd, uint32_t aTimeout)
     {
         return AddJoiner(&aEui64, nullptr, aPskd, aTimeout);
     }
@@ -149,12 +149,12 @@ public:
      * @param[in]  aPskd       A pointer to the PSKd.
      * @param[in]  aTimeout    A time after which a Joiner is automatically removed, in seconds.
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NO_BUFS        No buffers available to add the Joiner.
+     * @retval kErrorNoBufs        No buffers available to add the Joiner.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError AddJoiner(const JoinerDiscerner &aDiscerner, const char *aPskd, uint32_t aTimeout)
+    Error AddJoiner(const JoinerDiscerner &aDiscerner, const char *aPskd, uint32_t aTimeout)
     {
         return AddJoiner(nullptr, &aDiscerner, aPskd, aTimeout);
     }
@@ -165,23 +165,23 @@ public:
      * @param[inout]    aIterator   A iterator to the index of the joiner.
      * @param[out]      aJoiner     A reference to Joiner info.
      *
-     * @retval OT_ERROR_NONE        Successfully get the Joiner info.
+     * @retval kErrorNone       Successfully get the Joiner info.
-     * @retval OT_ERROR_NOT_FOUND   Not found next Joiner.
+     * @retval kErrorNotFound   Not found next Joiner.
      *
      */
-    otError GetNextJoinerInfo(uint16_t &aIterator, otJoinerInfo &aJoiner) const;
+    Error GetNextJoinerInfo(uint16_t &aIterator, otJoinerInfo &aJoiner) const;
 
     /**
      * This method removes a Joiner entry accepting any Joiner.
      *
      * @param[in]  aDelay         The delay to remove Joiner (in seconds).
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NOT_FOUND      The Joiner entry accepting any Joiner was not found.
+     * @retval kErrorNotFound      The Joiner entry accepting any Joiner was not found.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError RemoveJoinerAny(uint32_t aDelay) { return RemoveJoiner(nullptr, nullptr, aDelay); }
+    Error RemoveJoinerAny(uint32_t aDelay) { return RemoveJoiner(nullptr, nullptr, aDelay); }
 
     /**
      * This method removes a Joiner entry.
@@ -189,12 +189,12 @@ public:
      * @param[in]  aEui64         The Joiner's IEEE EUI-64.
      * @param[in]  aDelay         The delay to remove Joiner (in seconds).
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NOT_FOUND      The Joiner specified by @p aEui64 was not found.
+     * @retval kErrorNotFound      The Joiner specified by @p aEui64 was not found.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError RemoveJoiner(const Mac::ExtAddress &aEui64, uint32_t aDelay)
+    Error RemoveJoiner(const Mac::ExtAddress &aEui64, uint32_t aDelay)
     {
         return RemoveJoiner(&aEui64, nullptr, aDelay);
     }
@@ -205,12 +205,12 @@ public:
      * @param[in]  aDiscerner     A Joiner Discerner.
      * @param[in]  aDelay         The delay to remove Joiner (in seconds).
      *
-     * @retval OT_ERROR_NONE           Successfully added the Joiner.
+     * @retval kErrorNone          Successfully added the Joiner.
-     * @retval OT_ERROR_NOT_FOUND      The Joiner specified by @p aEui64 was not found.
+     * @retval kErrorNotFound      The Joiner specified by @p aEui64 was not found.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError RemoveJoiner(const JoinerDiscerner &aDiscerner, uint32_t aDelay)
+    Error RemoveJoiner(const JoinerDiscerner &aDiscerner, uint32_t aDelay)
     {
         return RemoveJoiner(nullptr, &aDiscerner, aDelay);
     }
@@ -228,11 +228,11 @@ public:
      *
      * @param[in]  aProvisioningUrl  A pointer to the Provisioning URL (may be nullptr to set URL to empty string).
      *
-     * @retval OT_ERROR_NONE          Successfully set the Provisioning URL.
+     * @retval kErrorNone         Successfully set the Provisioning URL.
-     * @retval OT_ERROR_INVALID_ARGS  @p aProvisioningUrl is invalid (too long).
+     * @retval kErrorInvalidArgs  @p aProvisioningUrl is invalid (too long).
      *
      */
-    otError SetProvisioningUrl(const char *aProvisioningUrl);
+    Error SetProvisioningUrl(const char *aProvisioningUrl);
 
     /**
      * This method returns the Commissioner Session ID.
@@ -272,12 +272,12 @@ public:
      * @param[in]  aTlvs        A pointer to Commissioning Data TLVs.
      * @param[in]  aLength      The length of requested TLVs in bytes.
      *
-     * @retval OT_ERROR_NONE           Send MGMT_COMMISSIONER_GET successfully.
+     * @retval kErrorNone          Send MGMT_COMMISSIONER_GET successfully.
-     * @retval OT_ERROR_NO_BUFS        Insufficient buffer space to send.
+     * @retval kErrorNoBufs        Insufficient buffer space to send.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError SendMgmtCommissionerGetRequest(const uint8_t *aTlvs, uint8_t aLength);
+    Error SendMgmtCommissionerGetRequest(const uint8_t *aTlvs, uint8_t aLength);
 
     /**
      * This method sends MGMT_COMMISSIONER_SET.
@@ -286,14 +286,12 @@ public:
      * @param[in]  aTlvs        A pointer to user specific Commissioning Data TLVs.
      * @param[in]  aLength      The length of user specific TLVs in bytes.
      *
-     * @retval OT_ERROR_NONE           Send MGMT_COMMISSIONER_SET successfully.
+     * @retval kErrorNone          Send MGMT_COMMISSIONER_SET successfully.
-     * @retval OT_ERROR_NO_BUFS        Insufficient buffer space to send.
+     * @retval kErrorNoBufs        Insufficient buffer space to send.
-     * @retval OT_ERROR_INVALID_STATE  Commissioner service is not started.
+     * @retval kErrorInvalidState  Commissioner service is not started.
      *
      */
-    otError SendMgmtCommissionerSetRequest(const otCommissioningDataset &aDataset,
+    Error SendMgmtCommissionerSetRequest(const otCommissioningDataset &aDataset, const uint8_t *aTlvs, uint8_t aLength);
-                                           const uint8_t *               aTlvs,
-                                           uint8_t                       aLength);
 
     /**
      * This method returns a reference to the AnnounceBeginClient instance.
@@ -374,12 +372,12 @@ private:
     Joiner *FindBestMatchingJoinerEntry(const Mac::ExtAddress &aReceivedJoinerId);
     void    RemoveJoinerEntry(Joiner &aJoiner);
 
-    otError AddJoiner(const Mac::ExtAddress *aEui64,
+    Error AddJoiner(const Mac::ExtAddress *aEui64,
-                      const JoinerDiscerner *aDiscerner,
+                    const JoinerDiscerner *aDiscerner,
-                      const char *           aPskd,
+                    const char *           aPskd,
-                      uint32_t               aTimeout);
+                    uint32_t               aTimeout);
-    otError RemoveJoiner(const Mac::ExtAddress *aEui64, const JoinerDiscerner *aDiscerner, uint32_t aDelay);
+    Error RemoveJoiner(const Mac::ExtAddress *aEui64, const JoinerDiscerner *aDiscerner, uint32_t aDelay);
-    void    RemoveJoiner(Joiner &aJoiner, uint32_t aDelay);
+    void  RemoveJoiner(Joiner &aJoiner, uint32_t aDelay);
 
     void AddCoapResources(void);
     void RemoveCoapResources(void);
@@ -395,27 +393,27 @@ private:
     static void HandleMgmtCommissionerSetResponse(void *               aContext,
                                                   otMessage *          aMessage,
                                                   const otMessageInfo *aMessageInfo,
-                                                  otError              aResult);
+                                                  Error                aResult);
     void        HandleMgmtCommissionerSetResponse(Coap::Message *         aMessage,
                                                   const Ip6::MessageInfo *aMessageInfo,
-                                                  otError                 aResult);
+                                                  Error                   aResult);
     static void HandleMgmtCommissionerGetResponse(void *               aContext,
                                                   otMessage *          aMessage,
                                                   const otMessageInfo *aMessageInfo,
-                                                  otError              aResult);
+                                                  Error                aResult);
     void        HandleMgmtCommissionerGetResponse(Coap::Message *         aMessage,
                                                   const Ip6::MessageInfo *aMessageInfo,
-                                                  otError                 aResult);
+                                                  Error                   aResult);
     static void HandleLeaderPetitionResponse(void *               aContext,
                                              otMessage *          aMessage,
                                              const otMessageInfo *aMessageInfo,
-                                             otError              aResult);
+                                             Error                aResult);
-    void HandleLeaderPetitionResponse(Coap::Message *aMessage, const Ip6::MessageInfo *aMessageInfo, otError aResult);
+    void HandleLeaderPetitionResponse(Coap::Message *aMessage, const Ip6::MessageInfo *aMessageInfo, Error aResult);
     static void HandleLeaderKeepAliveResponse(void *               aContext,
                                               otMessage *          aMessage,
                                               const otMessageInfo *aMessageInfo,
-                                              otError              aResult);
+                                              Error                aResult);
-    void HandleLeaderKeepAliveResponse(Coap::Message *aMessage, const Ip6::MessageInfo *aMessageInfo, otError aResult);
+    void HandleLeaderKeepAliveResponse(Coap::Message *aMessage, const Ip6::MessageInfo *aMessageInfo, Error aResult);
 
     static void HandleCoapsConnected(bool aConnected, void *aContext);
     void        HandleCoapsConnected(bool aConnected);
@@ -431,14 +429,14 @@ private:
 
     void SendJoinFinalizeResponse(const Coap::Message &aRequest, StateTlv::State aState);
 
-    static otError SendRelayTransmit(void *aContext, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    static Error SendRelayTransmit(void *aContext, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    otError        SendRelayTransmit(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    Error        SendRelayTransmit(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
-    void    ComputeBloomFilter(SteeringData &aSteeringData) const;
+    void  ComputeBloomFilter(SteeringData &aSteeringData) const;
-    void    SendCommissionerSet(void);
+    void  SendCommissionerSet(void);
-    otError SendPetition(void);
+    Error SendPetition(void);
-    void    SendKeepAlive(void);
+    void  SendKeepAlive(void);
-    void    SendKeepAlive(uint16_t aSessionId);
+    void  SendKeepAlive(uint16_t aSessionId);
 
     void SetState(State aState);
     void SignalJoinerEvent(JoinerEvent aEvent, const Joiner *aJoiner) const;

src/core/meshcop/dataset.cpp

@@ -48,9 +48,9 @@
 namespace ot {
 namespace MeshCoP {
 
-otError Dataset::Info::GenerateRandom(Instance &aInstance)
+Error Dataset::Info::GenerateRandom(Instance &aInstance)
 {
-    otError          error;
+    Error            error;
     Mac::ChannelMask supportedChannels = aInstance.Get<Mac::Mac>().GetSupportedChannelMask();
     Mac::ChannelMask preferredChannels(aInstance.Get<Radio>().GetPreferredChannelMask());
 
@@ -285,9 +285,9 @@ void Dataset::SetFrom(const otOperationalDatasetTlvs &aDataset)
     memcpy(mTlvs, aDataset.mTlvs, mLength);
 }
 
-otError Dataset::SetFrom(const Info &aDatasetInfo)
+Error Dataset::SetFrom(const Info &aDatasetInfo)
 {
-    otError error = OT_ERROR_NONE;
+    Error error = kErrorNone;
 
     if (aDatasetInfo.IsActiveTimestampPresent())
     {
@@ -400,9 +400,9 @@ void Dataset::SetTimestamp(const Timestamp &aTimestamp)
     IgnoreError(SetTlv((mType == kActive) ? Tlv::kActiveTimestamp : Tlv::kPendingTimestamp, aTimestamp));
 }
 
-otError Dataset::SetTlv(Tlv::Type aType, const void *aValue, uint8_t aLength)
+Error Dataset::SetTlv(Tlv::Type aType, const void *aValue, uint8_t aLength)
 {
-    otError  error          = OT_ERROR_NONE;
+    Error    error          = kErrorNone;
     uint16_t bytesAvailable = sizeof(mTlvs) - mLength;
     Tlv *    old            = GetTlv(aType);
     Tlv      tlv;
@@ -412,7 +412,7 @@ otError Dataset::SetTlv(Tlv::Type aType, const void *aValue, uint8_t aLength)
         bytesAvailable += sizeof(Tlv) + old->GetLength();
     }
 
-    VerifyOrExit(sizeof(Tlv) + aLength <= bytesAvailable, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(sizeof(Tlv) + aLength <= bytesAvailable, error = kErrorNoBufs);
 
     if (old != nullptr)
     {
@@ -433,20 +433,20 @@ exit:
     return error;
 }
 
-otError Dataset::SetTlv(const Tlv &aTlv)
+Error Dataset::SetTlv(const Tlv &aTlv)
 {
     return SetTlv(aTlv.GetType(), aTlv.GetValue(), aTlv.GetLength());
 }
 
-otError Dataset::Set(const Message &aMessage, uint16_t aOffset, uint8_t aLength)
+Error Dataset::Set(const Message &aMessage, uint16_t aOffset, uint8_t aLength)
 {
-    otError error = OT_ERROR_INVALID_ARGS;
+    Error error = kErrorInvalidArgs;
 
     SuccessOrExit(aMessage.Read(aOffset, mTlvs, aLength));
     mLength = aLength;
 
     mUpdateTime = TimerMilli::GetNow();
-    error       = OT_ERROR_NONE;
+    error       = kErrorNone;
 
 exit:
     return error;
@@ -463,9 +463,9 @@ exit:
     return;
 }
 
-otError Dataset::AppendMleDatasetTlv(Message &aMessage) const
+Error Dataset::AppendMleDatasetTlv(Message &aMessage) const
 {
-    otError        error = OT_ERROR_NONE;
+    Error          error = kErrorNone;
     Mle::Tlv       tlv;
     Mle::Tlv::Type type;
 
@@ -519,13 +519,13 @@ void Dataset::RemoveTlv(Tlv *aTlv)
     mLength -= length;
 }
 
-otError Dataset::ApplyConfiguration(Instance &aInstance, bool *aIsMasterKeyUpdated) const
+Error Dataset::ApplyConfiguration(Instance &aInstance, bool *aIsMasterKeyUpdated) const
 {
     Mac::Mac &  mac        = aInstance.Get<Mac::Mac>();
     KeyManager &keyManager = aInstance.Get<KeyManager>();
-    otError     error      = OT_ERROR_NONE;
+    Error       error      = kErrorNone;
 
-    VerifyOrExit(IsValid(), error = OT_ERROR_PARSE);
+    VerifyOrExit(IsValid(), error = kErrorParse);
 
     if (aIsMasterKeyUpdated)
     {
@@ -542,10 +542,10 @@ otError Dataset::ApplyConfiguration(Instance &aInstance, bool *aIsMasterKeyUpdat
 
             error = mac.SetPanChannel(channel);
 
-            if (error != OT_ERROR_NONE)
+            if (error != kErrorNone)
             {
                 otLogWarnMeshCoP("DatasetManager::ApplyConfiguration() Failed to set channel to %d (%s)", channel,
-                                 otThreadErrorToString(error));
+                                 ErrorToString(error));
                 ExitNow();
             }
 

src/core/meshcop/dataset.hpp

@@ -603,10 +603,10 @@ public:
          *
          * @param[in] aInstance    The OpenThread instance.
          *
-         * @retval OT_ERROR_NONE If the Dataset was generated successfully.
+         * @retval kErrorNone If the Dataset was generated successfully.
          *
          */
-        otError GenerateRandom(Instance &aInstance);
+        Error GenerateRandom(Instance &aInstance);
 
         /**
          * This method checks whether the Dataset is a subset of another one, i.e., all the components in the current
@@ -764,11 +764,11 @@ public:
      *
      * @param[in]  aTlv  A reference to the TLV.
      *
-     * @retval OT_ERROR_NONE     Successfully set the TLV.
+     * @retval kErrorNone    Successfully set the TLV.
-     * @retval OT_ERROR_NO_BUFS  Could not set the TLV due to insufficient buffer space.
+     * @retval kErrorNoBufs  Could not set the TLV due to insufficient buffer space.
      *
      */
-    otError SetTlv(const Tlv &aTlv);
+    Error SetTlv(const Tlv &aTlv);
 
     /**
      * This method sets a TLV with a given TLV Type and Value.
@@ -777,11 +777,11 @@ public:
      * @param[in] aValue    A pointer to TLV Value.
      * @param[in] aLength   The TLV Length in bytes (length of @p aValue).
      *
-     * @retval OT_ERROR_NONE     Successfully set the TLV.
+     * @retval kErrorNone    Successfully set the TLV.
-     * @retval OT_ERROR_NO_BUFS  Could not set the TLV due to insufficient buffer space.
+     * @retval kErrorNoBufs  Could not set the TLV due to insufficient buffer space.
      *
      */
-    otError SetTlv(Tlv::Type aType, const void *aValue, uint8_t aLength);
+    Error SetTlv(Tlv::Type aType, const void *aValue, uint8_t aLength);
 
     /**
      * This template method sets a TLV with a given TLV Type and Value.
@@ -791,11 +791,11 @@ public:
      * @param[in] aType     The TLV Type.
      * @param[in] aValue    The TLV Value (of type `ValueType`).
      *
-     * @retval OT_ERROR_NONE     Successfully set the TLV.
+     * @retval kErrorNone    Successfully set the TLV.
-     * @retval OT_ERROR_NO_BUFS  Could not set the TLV due to insufficient buffer space.
+     * @retval kErrorNoBufs  Could not set the TLV due to insufficient buffer space.
      *
      */
-    template <typename ValueType> otError SetTlv(Tlv::Type aType, const ValueType &aValue)
+    template <typename ValueType> Error SetTlv(Tlv::Type aType, const ValueType &aValue)
     {
         static_assert(!TypeTraits::IsPointer<ValueType>::kValue, "ValueType must not be a pointer");
 
@@ -809,11 +809,11 @@ public:
      * @param[in]  aOffset   The message buffer offset where the dataset starts.
      * @param[in]  aLength   The TLVs length in the message buffer in bytes.
      *
-     * @retval OT_ERROR_NONE          Successfully set the Dataset.
+     * @retval kErrorNone         Successfully set the Dataset.
-     * @retval OT_ERROR_INVALID_ARGS  The values of @p aOffset and @p aLength are not valid for @p aMessage.
+     * @retval kErrorInvalidArgs  The values of @p aOffset and @p aLength are not valid for @p aMessage.
      *
      */
-    otError Set(const Message &aMessage, uint16_t aOffset, uint8_t aLength);
+    Error Set(const Message &aMessage, uint16_t aOffset, uint8_t aLength);
 
     /**
      * This method sets the Dataset using an existing Dataset.
@@ -831,11 +831,11 @@ public:
      *
      * @param[in]  aDatasetInfo  The input Dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE          Successfully set the Dataset.
+     * @retval kErrorNone         Successfully set the Dataset.
-     * @retval OT_ERROR_INVALID_ARGS  Dataset is missing Active and/or Pending Timestamp.
+     * @retval kErrorInvalidArgs  Dataset is missing Active and/or Pending Timestamp.
      *
      */
-    otError SetFrom(const Info &aDatasetInfo);
+    Error SetFrom(const Info &aDatasetInfo);
 
     /**
      * This method sets the Dataset using @p aDataset.
@@ -858,11 +858,11 @@ public:
      *
      * @param[in] aMessage       A message to append to.
      *
-     * @retval OT_ERROR_NONE     Successfully append MLE Dataset TLV without MeshCoP Sub Timestamp TLV.
+     * @retval kErrorNone    Successfully append MLE Dataset TLV without MeshCoP Sub Timestamp TLV.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to append the message with MLE Dataset TLV.
+     * @retval kErrorNoBufs  Insufficient available buffers to append the message with MLE Dataset TLV.
      *
      */
-    otError AppendMleDatasetTlv(Message &aMessage) const;
+    Error AppendMleDatasetTlv(Message &aMessage) const;
 
     /**
      * This method applies the Active or Pending Dataset to the Thread interface.
@@ -870,11 +870,11 @@ public:
      * @param[in]  aInstance           A reference to the OpenThread instance.
      * @param[out] aIsMasterKeyUpdated A pointer to where to place whether master key was updated.
      *
-     * @retval OT_ERROR_NONE   Successfully applied configuration.
+     * @retval kErrorNone   Successfully applied configuration.
-     * @retval OT_ERROR_PARSE  The dataset has at least one TLV with invalid format.
+     * @retval kErrorParse  The dataset has at least one TLV with invalid format.
      *
      */
-    otError ApplyConfiguration(Instance &aInstance, bool *aIsMasterKeyUpdated = nullptr) const;
+    Error ApplyConfiguration(Instance &aInstance, bool *aIsMasterKeyUpdated = nullptr) const;
 
     /**
      * This method converts a Pending Dataset to an Active Dataset.
@@ -943,11 +943,11 @@ private:
  * @param[in] aType     The TLV Type.
  * @param[in] aValue    The TLV value (as `uint16_t`).
  *
- * @retval OT_ERROR_NONE     Successfully set the TLV.
+ * @retval kErrorNone    Successfully set the TLV.
- * @retval OT_ERROR_NO_BUFS  Could not set the TLV due to insufficient buffer space.
+ * @retval kErrorNoBufs  Could not set the TLV due to insufficient buffer space.
  *
  */
-template <> inline otError Dataset::SetTlv(Tlv::Type aType, const uint16_t &aValue)
+template <> inline Error Dataset::SetTlv(Tlv::Type aType, const uint16_t &aValue)
 {
     uint16_t value = Encoding::BigEndian::HostSwap16(aValue);
 
@@ -960,11 +960,11 @@ template <> inline otError Dataset::SetTlv(Tlv::Type aType, const uint16_t &aVal
  * @param[in] aType     The TLV Type.
  * @param[in] aValue    The TLV value (as `uint32_t`).
  *
- * @retval OT_ERROR_NONE     Successfully set the TLV.
+ * @retval kErrorNone    Successfully set the TLV.
- * @retval OT_ERROR_NO_BUFS  Could not set the TLV due to insufficient buffer space.
+ * @retval kErrorNoBufs  Could not set the TLV due to insufficient buffer space.
  *
  */
-template <> inline otError Dataset::SetTlv(Tlv::Type aType, const uint32_t &aValue)
+template <> inline Error Dataset::SetTlv(Tlv::Type aType, const uint32_t &aValue)
 {
     uint32_t value = Encoding::BigEndian::HostSwap32(aValue);
 

src/core/meshcop/dataset_local.cpp

@@ -66,10 +66,10 @@ void DatasetLocal::Clear(void)
     mSaved            = false;
 }
 
-otError DatasetLocal::Restore(Dataset &aDataset)
+Error DatasetLocal::Restore(Dataset &aDataset)
 {
     const Timestamp *timestamp;
-    otError          error;
+    Error            error;
 
     mTimestampPresent = false;
 
@@ -89,14 +89,14 @@ exit:
     return error;
 }
 
-otError DatasetLocal::Read(Dataset &aDataset) const
+Error DatasetLocal::Read(Dataset &aDataset) const
 {
     DelayTimerTlv *delayTimer;
     uint32_t       elapsed;
-    otError        error;
+    Error          error;
 
     error = Get<Settings>().ReadOperationalDataset(IsActive(), aDataset);
-    VerifyOrExit(error == OT_ERROR_NONE, aDataset.mLength = 0);
+    VerifyOrExit(error == kErrorNone, aDataset.mLength = 0);
 
     if (mType == Dataset::kActive)
     {
@@ -126,10 +126,10 @@ exit:
     return error;
 }
 
-otError DatasetLocal::Read(Dataset::Info &aDatasetInfo) const
+Error DatasetLocal::Read(Dataset::Info &aDatasetInfo) const
 {
     Dataset dataset(mType);
-    otError error;
+    Error   error;
 
     aDatasetInfo.Clear();
 
@@ -140,10 +140,10 @@ exit:
     return error;
 }
 
-otError DatasetLocal::Read(otOperationalDatasetTlvs &aDataset) const
+Error DatasetLocal::Read(otOperationalDatasetTlvs &aDataset) const
 {
     Dataset dataset(mType);
-    otError error;
+    Error   error;
 
     memset(&aDataset, 0, sizeof(aDataset));
 
@@ -154,9 +154,9 @@ exit:
     return error;
 }
 
-otError DatasetLocal::Save(const Dataset::Info &aDatasetInfo)
+Error DatasetLocal::Save(const Dataset::Info &aDatasetInfo)
 {
-    otError error;
+    Error   error;
     Dataset dataset(mType);
 
     SuccessOrExit(error = dataset.SetFrom(aDatasetInfo));
@@ -166,7 +166,7 @@ exit:
     return error;
 }
 
-otError DatasetLocal::Save(const otOperationalDatasetTlvs &aDataset)
+Error DatasetLocal::Save(const otOperationalDatasetTlvs &aDataset)
 {
     Dataset dataset(mType);
 
@@ -175,10 +175,10 @@ otError DatasetLocal::Save(const otOperationalDatasetTlvs &aDataset)
     return Save(dataset);
 }
 
-otError DatasetLocal::Save(const Dataset &aDataset)
+Error DatasetLocal::Save(const Dataset &aDataset)
 {
     const Timestamp *timestamp;
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
 
     if (aDataset.GetSize() == 0)
     {

src/core/meshcop/dataset_local.hpp

@@ -95,44 +95,44 @@ public:
      *
      * @param[out]  aDataset  Where to place the dataset.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Restore(Dataset &aDataset);
+    Error Restore(Dataset &aDataset);
 
     /**
      * This method retrieves the dataset from non-volatile memory.
      *
      * @param[out]  aDataset  Where to place the dataset.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(Dataset &aDataset) const;
+    Error Read(Dataset &aDataset) const;
 
     /**
      * This method retrieves the dataset from non-volatile memory.
      *
      * @param[out]  aDatasetInfo  Where to place the dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(Dataset::Info &aDatasetInfo) const;
+    Error Read(Dataset::Info &aDatasetInfo) const;
 
     /**
      * This method retrieves the dataset from non-volatile memory.
      *
      * @param[out]  aDataset  Where to place the dataset.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(otOperationalDatasetTlvs &aDataset) const;
+    Error Read(otOperationalDatasetTlvs &aDataset) const;
 
     /**
      * This method returns the local time this dataset was last updated or restored.
@@ -147,33 +147,33 @@ public:
      *
      * @param[in] aDatasetInfo     The Dataset to save as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the dataset.
+     * @retval kErrorNone             Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError Save(const Dataset::Info &aDatasetInfo);
+    Error Save(const Dataset::Info &aDatasetInfo);
 
     /**
      * This method stores the dataset into non-volatile memory.
      *
      * @param[in]  aDataset  The Dataset to save as `otOperationalDatasetTlvs`.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the dataset.
+     * @retval kErrorNone             Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError Save(const otOperationalDatasetTlvs &aDataset);
+    Error Save(const otOperationalDatasetTlvs &aDataset);
 
     /**
      * This method stores the dataset into non-volatile memory.
      *
      * @param[in]  aDataset  The Dataset to save.
      *
-     * @retval OT_ERROR_NONE              Successfully saved the dataset.
+     * @retval kErrorNone             Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED   The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError Save(const Dataset &aDataset);
+    Error Save(const Dataset &aDataset);
 
     /**
      * This method compares this dataset to another based on the timestamp.

src/core/meshcop/dataset_manager.cpp

@@ -78,9 +78,9 @@ int DatasetManager::Compare(const Timestamp &aTimestamp) const
     return rval;
 }
 
-otError DatasetManager::Restore(void)
+Error DatasetManager::Restore(void)
 {
-    otError          error;
+    Error            error;
     Dataset          dataset(GetType());
     const Timestamp *timestamp;
 
@@ -109,9 +109,9 @@ exit:
     return error;
 }
 
-otError DatasetManager::ApplyConfiguration(void) const
+Error DatasetManager::ApplyConfiguration(void) const
 {
-    otError error;
+    Error   error;
     Dataset dataset(GetType());
 
     SuccessOrExit(error = Read(dataset));
@@ -135,9 +135,9 @@ void DatasetManager::HandleDetach(void)
     IgnoreError(Restore());
 }
 
-otError DatasetManager::Save(const Dataset &aDataset)
+Error DatasetManager::Save(const Dataset &aDataset)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     const Timestamp *timestamp;
     int              compare;
     bool             isMasterkeyUpdated = false;
@@ -167,7 +167,7 @@ otError DatasetManager::Save(const Dataset &aDataset)
     }
     else if (compare < 0)
     {
-        VerifyOrExit(!Get<Mle::MleRouter>().IsLeader(), error = OT_ERROR_INVALID_STATE);
+        VerifyOrExit(!Get<Mle::MleRouter>().IsLeader(), error = kErrorInvalidState);
         SendSet();
     }
 
@@ -177,9 +177,9 @@ exit:
     return error;
 }
 
-otError DatasetManager::Save(const Dataset::Info &aDatasetInfo)
+Error DatasetManager::Save(const Dataset::Info &aDatasetInfo)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = mLocal.Save(aDatasetInfo));
     HandleDatasetUpdated();
@@ -188,9 +188,9 @@ exit:
     return error;
 }
 
-otError DatasetManager::Save(const otOperationalDatasetTlvs &aDataset)
+Error DatasetManager::Save(const otOperationalDatasetTlvs &aDataset)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = mLocal.Save(aDataset));
     HandleDatasetUpdated();
@@ -199,9 +199,9 @@ exit:
     return error;
 }
 
-otError DatasetManager::SaveLocal(const Dataset &aDataset)
+Error DatasetManager::SaveLocal(const Dataset &aDataset)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = mLocal.Save(aDataset));
     HandleDatasetUpdated();
@@ -245,9 +245,9 @@ void DatasetManager::SignalDatasetChange(void) const
                                                                 : kEventPendingDatasetChanged);
 }
 
-otError DatasetManager::GetChannelMask(Mac::ChannelMask &aChannelMask) const
+Error DatasetManager::GetChannelMask(Mac::ChannelMask &aChannelMask) const
 {
-    otError                        error;
+    Error                          error;
     const MeshCoP::ChannelMaskTlv *channelMaskTlv;
     uint32_t                       mask;
     Dataset                        dataset(GetType());
@@ -255,12 +255,12 @@ otError DatasetManager::GetChannelMask(Mac::ChannelMask &aChannelMask) const
     SuccessOrExit(error = Read(dataset));
 
     channelMaskTlv = dataset.GetTlv<ChannelMaskTlv>();
-    VerifyOrExit(channelMaskTlv != nullptr, error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(channelMaskTlv != nullptr, error = kErrorNotFound);
     VerifyOrExit((mask = channelMaskTlv->GetChannelMask()) != 0);
 
     aChannelMask.SetMask(mask & Get<Mac::Mac>().GetSupportedChannelMask().GetMask());
 
-    VerifyOrExit(!aChannelMask.IsEmpty(), error = OT_ERROR_NOT_FOUND);
+    VerifyOrExit(!aChannelMask.IsEmpty(), error = kErrorNotFound);
 
 exit:
     return error;
@@ -273,14 +273,14 @@ void DatasetManager::HandleTimer(void)
 
 void DatasetManager::SendSet(void)
 {
-    otError          error;
+    Error            error;
     Coap::Message *  message = nullptr;
     Ip6::MessageInfo messageInfo;
     Dataset          dataset(GetType());
 
-    VerifyOrExit(!mCoapPending, error = OT_ERROR_BUSY);
+    VerifyOrExit(!mCoapPending, error = kErrorBusy);
-    VerifyOrExit(Get<Mle::MleRouter>().IsAttached(), error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(Get<Mle::MleRouter>().IsAttached(), error = kErrorInvalidState);
-    VerifyOrExit(mLocal.Compare(GetTimestamp()) < 0, error = OT_ERROR_INVALID_STATE);
+    VerifyOrExit(mLocal.Compare(GetTimestamp()) < 0, error = kErrorInvalidState);
 
     if (IsActiveDataset())
     {
@@ -293,11 +293,11 @@ void DatasetManager::SendSet(void)
         if (pendingActiveTimestamp != nullptr && mLocal.Compare(pendingActiveTimestamp) == 0)
         {
             // stop registration attempts during dataset transition
-            ExitNow(error = OT_ERROR_INVALID_STATE);
+            ExitNow(error = kErrorInvalidState);
         }
     }
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error =
                       message->InitAsConfirmablePost(IsActiveDataset() ? UriPath::kActiveSet : UriPath::kPendingSet));
@@ -318,11 +318,11 @@ exit:
 
     switch (error)
     {
-    case OT_ERROR_NONE:
+    case kErrorNone:
         mCoapPending = true;
         break;
 
-    case OT_ERROR_NO_BUFS:
+    case kErrorNoBufs:
         mTimer.Start(kDelayNoBufs);
         OT_FALL_THROUGH;
 
@@ -336,7 +336,7 @@ exit:
 void DatasetManager::HandleCoapResponse(void *               aContext,
                                         otMessage *          aMessage,
                                         const otMessageInfo *aMessageInfo,
-                                        otError              aError)
+                                        Error                aError)
 {
     OT_UNUSED_VARIABLE(aMessage);
     OT_UNUSED_VARIABLE(aMessageInfo);
@@ -401,13 +401,13 @@ void DatasetManager::SendGetResponse(const Coap::Message &   aRequest,
                                      uint8_t *               aTlvs,
                                      uint8_t                 aLength) const
 {
-    otError        error = OT_ERROR_NONE;
+    Error          error = kErrorNone;
     Coap::Message *message;
     Dataset        dataset(GetType());
 
     IgnoreError(Read(dataset));
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error = message->SetDefaultResponseHeader(aRequest));
     SuccessOrExit(error = message->SetPayloadMarker());
@@ -454,9 +454,9 @@ exit:
     FreeMessageOnError(message, error);
 }
 
-otError DatasetManager::AppendDatasetToMessage(const Dataset::Info &aDatasetInfo, Message &aMessage) const
+Error DatasetManager::AppendDatasetToMessage(const Dataset::Info &aDatasetInfo, Message &aMessage) const
 {
-    otError error;
+    Error   error;
     Dataset dataset(GetType());
 
     SuccessOrExit(error = dataset.SetFrom(aDatasetInfo));
@@ -466,13 +466,13 @@ exit:
     return error;
 }
 
-otError DatasetManager::SendSetRequest(const Dataset::Info &aDatasetInfo, const uint8_t *aTlvs, uint8_t aLength)
+Error DatasetManager::SendSetRequest(const Dataset::Info &aDatasetInfo, const uint8_t *aTlvs, uint8_t aLength)
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Coap::Message *  message;
     Ip6::MessageInfo messageInfo;
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error =
                       message->InitAsConfirmablePost(IsActiveDataset() ? UriPath::kActiveSet : UriPath::kPendingSet));
@@ -487,7 +487,7 @@ otError DatasetManager::SendSetRequest(const Dataset::Info &aDatasetInfo, const
 
         for (const Tlv *cur = reinterpret_cast<const Tlv *>(aTlvs); cur < end; cur = cur->GetNext())
         {
-            VerifyOrExit((cur + 1) <= end, error = OT_ERROR_INVALID_ARGS);
+            VerifyOrExit((cur + 1) <= end, error = kErrorInvalidArgs);
 
             if (cur->GetType() == Tlv::kCommissionerSessionId)
             {
@@ -529,12 +529,12 @@ exit:
     return error;
 }
 
-otError DatasetManager::SendGetRequest(const Dataset::Components &aDatasetComponents,
+Error DatasetManager::SendGetRequest(const Dataset::Components &aDatasetComponents,
-                                       const uint8_t *            aTlvTypes,
+                                     const uint8_t *            aTlvTypes,
-                                       uint8_t                    aLength,
+                                     uint8_t                    aLength,
-                                       const otIp6Address *       aAddress) const
+                                     const otIp6Address *       aAddress) const
 {
-    otError          error = OT_ERROR_NONE;
+    Error            error = kErrorNone;
     Coap::Message *  message;
     Ip6::MessageInfo messageInfo;
     Tlv              tlv;
@@ -603,7 +603,7 @@ otError DatasetManager::SendGetRequest(const Dataset::Components &aDatasetCompon
         datasetTlvs[length++] = Tlv::kChannelMask;
     }
 
-    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit((message = NewMeshCoPMessage(Get<Tmf::TmfAgent>())) != nullptr, error = kErrorNoBufs);
 
     SuccessOrExit(error =
                       message->InitAsConfirmablePost(IsActiveDataset() ? UriPath::kActiveGet : UriPath::kPendingGet));
@@ -679,9 +679,9 @@ exit:
     return isValid;
 }
 
-otError ActiveDataset::Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength)
+Error ActiveDataset::Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     Dataset dataset(GetType());
 
     SuccessOrExit(error = dataset.Set(aMessage, aOffset, aLength));
@@ -734,9 +734,9 @@ void PendingDataset::ClearNetwork(void)
     IgnoreError(DatasetManager::Save(dataset));
 }
 
-otError PendingDataset::Save(const Dataset::Info &aDatasetInfo)
+Error PendingDataset::Save(const Dataset::Info &aDatasetInfo)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = DatasetManager::Save(aDatasetInfo));
     StartDelayTimer();
@@ -745,9 +745,9 @@ exit:
     return error;
 }
 
-otError PendingDataset::Save(const otOperationalDatasetTlvs &aDataset)
+Error PendingDataset::Save(const otOperationalDatasetTlvs &aDataset)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = DatasetManager::Save(aDataset));
     StartDelayTimer();
@@ -756,9 +756,9 @@ exit:
     return error;
 }
 
-otError PendingDataset::Save(const Dataset &aDataset)
+Error PendingDataset::Save(const Dataset &aDataset)
 {
-    otError error;
+    Error error;
 
     SuccessOrExit(error = DatasetManager::SaveLocal(aDataset));
     StartDelayTimer();
@@ -767,9 +767,9 @@ exit:
     return error;
 }
 
-otError PendingDataset::Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength)
+Error PendingDataset::Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength)
 {
-    otError error = OT_ERROR_NONE;
+    Error   error = kErrorNone;
     Dataset dataset(GetType());
 
     SuccessOrExit(error = dataset.Set(aMessage, aOffset, aLength));

src/core/meshcop/dataset_manager.hpp

@@ -64,11 +64,11 @@ public:
     /**
      * This method restores the Operational Dataset from non-volatile memory.
      *
-     * @retval OT_ERROR_NONE       Successfully restore the dataset.
+     * @retval kErrorNone      Successfully restore the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Restore(void);
+    Error Restore(void);
 
     /**
      * This method compares @p aTimestamp to the dataset's timestamp value.
@@ -87,53 +87,53 @@ public:
      *
      * @param[out]  aDataset  Where to place the dataset.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(Dataset &aDataset) const { return mLocal.Read(aDataset); }
+    Error Read(Dataset &aDataset) const { return mLocal.Read(aDataset); }
 
     /**
      * This method retrieves the dataset from non-volatile memory.
      *
      * @param[out]  aDatasetInfo  Where to place the dataset (as `Dataset::Info`).
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(Dataset::Info &aDatasetInfo) const { return mLocal.Read(aDatasetInfo); }
+    Error Read(Dataset::Info &aDatasetInfo) const { return mLocal.Read(aDatasetInfo); }
 
     /**
      * This method retrieves the dataset from non-volatile memory.
      *
      * @param[out]  aDataset  Where to place the dataset.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the dataset.
+     * @retval kErrorNone      Successfully retrieved the dataset.
-     * @retval OT_ERROR_NOT_FOUND  There is no corresponding dataset stored in non-volatile memory.
+     * @retval kErrorNotFound  There is no corresponding dataset stored in non-volatile memory.
      *
      */
-    otError Read(otOperationalDatasetTlvs &aDataset) const { return mLocal.Read(aDataset); }
+    Error Read(otOperationalDatasetTlvs &aDataset) const { return mLocal.Read(aDataset); }
 
     /**
      * This method retrieves the channel mask from local dataset.
      *
      * @param[out]  aChannelMask  A reference to the channel mask.
      *
-     * @retval OT_ERROR_NONE       Successfully retrieved the channel mask.
+     * @retval kErrorNone      Successfully retrieved the channel mask.
-     * @retval OT_ERROR_NOT_FOUND  There is no valid channel mask stored in local dataset.
+     * @retval kErrorNotFound  There is no valid channel mask stored in local dataset.
      *
      */
-    otError GetChannelMask(Mac::ChannelMask &aChannelMask) const;
+    Error GetChannelMask(Mac::ChannelMask &aChannelMask) const;
 
     /**
      * This method applies the Active or Pending Dataset to the Thread interface.
      *
-     * @retval OT_ERROR_NONE   Successfully applied configuration.
+     * @retval kErrorNone   Successfully applied configuration.
-     * @retval OT_ERROR_PARSE  The dataset has at least one TLV with invalid format.
+     * @retval kErrorParse  The dataset has at least one TLV with invalid format.
      *
      */
-    otError ApplyConfiguration(void) const;
+    Error ApplyConfiguration(void) const;
 
     /**
      * This method updates the Operational Dataset when detaching from the network.
@@ -150,11 +150,11 @@ public:
      * @param[in]  aTlvs         Any additional raw TLVs to include.
      * @param[in]  aLength       Number of bytes in @p aTlvs.
      *
-     * @retval OT_ERROR_NONE     Successfully send the meshcop dataset command.
+     * @retval kErrorNone    Successfully send the meshcop dataset command.
-     * @retval OT_ERROR_NO_BUFS  Insufficient buffer space to send.
+     * @retval kErrorNoBufs  Insufficient buffer space to send.
      *
      */
-    otError SendSetRequest(const Dataset::Info &aDatasetInfo, const uint8_t *aTlvs, uint8_t aLength);
+    Error SendSetRequest(const Dataset::Info &aDatasetInfo, const uint8_t *aTlvs, uint8_t aLength);
 
     /**
      * This method sends a MGMT_GET request.
@@ -164,25 +164,25 @@ public:
      * @param[in]  aLength             Number of bytes in @p aTlvTypes.
      * @param[in]  aAddress            The IPv6 destination address for the MGMT_GET request.
      *
-     * @retval OT_ERROR_NONE     Successfully send the meshcop dataset command.
+     * @retval kErrorNone     Successfully send the meshcop dataset command.
-     * @retval OT_ERROR_NO_BUFS  Insufficient buffer space to send.
+     * @retval kErrorNoBufs   Insufficient buffer space to send.
      *
      */
-    otError SendGetRequest(const Dataset::Components &aDatasetComponents,
+    Error SendGetRequest(const Dataset::Components &aDatasetComponents,
-                           const uint8_t *            aTlvTypes,
+                         const uint8_t *            aTlvTypes,
-                           uint8_t                    aLength,
+                         uint8_t                    aLength,
-                           const otIp6Address *       aAddress) const;
+                         const otIp6Address *       aAddress) const;
 #if OPENTHREAD_FTD
     /**
      * This method appends the MLE Dataset TLV but excluding MeshCoP Sub Timestamp TLV.
      *
      * @param[in] aMessage       The message to append the TLV to.
      *
-     * @retval OT_ERROR_NONE     Successfully append MLE Dataset TLV without MeshCoP Sub Timestamp TLV.
+     * @retval kErrorNone    Successfully append MLE Dataset TLV without MeshCoP Sub Timestamp TLV.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffers to append the message with MLE Dataset TLV.
+     * @retval kErrorNoBufs  Insufficient available buffers to append the message with MLE Dataset TLV.
      *
      */
-    otError AppendMleDatasetTlv(Message &aMessage) const;
+    Error AppendMleDatasetTlv(Message &aMessage) const;
 #endif
 
 protected:
@@ -200,11 +200,11 @@ protected:
          * @param[in]  aMessage  A message to read the TLV from.
          * @param[in]  aOffset   An offset into the message to read from.
          *
-         * @retval OT_ERROR_NONE    The TLV was read successfully.
+         * @retval kErrorNone    The TLV was read successfully.
-         * @retval OT_ERROR_PARSE   The TLV was not well-formed and could not be parsed.
+         * @retval kErrorParse   The TLV was not well-formed and could not be parsed.
          *
          */
-        otError ReadFromMessage(const Message &aMessage, uint16_t aOffset);
+        Error ReadFromMessage(const Message &aMessage, uint16_t aOffset);
 
     private:
         enum
@@ -244,33 +244,33 @@ protected:
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE   Successfully applied configuration.
+     * @retval kErrorNone   Successfully applied configuration.
-     * @retval OT_ERROR_PARSE  The dataset has at least one TLV with invalid format.
+     * @retval kErrorParse  The dataset has at least one TLV with invalid format.
      *
      */
-    otError Save(const Dataset &aDataset);
+    Error Save(const Dataset &aDataset);
 
     /**
      * This method saves the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDatasetInfo  The Operational Dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone             Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError Save(const Dataset::Info &aDatasetInfo);
+    Error Save(const Dataset::Info &aDatasetInfo);
 
     /**
      * This method saves the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone             Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented   The platform does not implement settings functionality.
      *
      */
-    otError Save(const otOperationalDatasetTlvs &aDataset);
+    Error Save(const otOperationalDatasetTlvs &aDataset);
 
     /**
      * This method sets the Operational Dataset for the partition.
@@ -283,18 +283,18 @@ protected:
      * @param[in]  aLength     The length of the Operational Dataset.
      *
      */
-    otError Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
+    Error Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
 
     /**
      * This method saves the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE   Successfully applied configuration.
+     * @retval kErrorNone   Successfully applied configuration.
-     * @retval OT_ERROR_PARSE  The dataset has at least one TLV with invalid format.
+     * @retval kErrorParse  The dataset has at least one TLV with invalid format.
      *
      */
-    otError SaveLocal(const Dataset &aDataset);
+    Error SaveLocal(const Dataset &aDataset);
 
     /**
      * This method handles a MGMT_GET request message.
@@ -327,11 +327,11 @@ protected:
      * @param[in]  aMessage      The CoAP message buffer.
      * @param[in]  aMessageInfo  The message info.
      *
-     * @retval OT_ERROR_NONE  The MGMT_SET request message was handled successfully.
+     * @retval kErrorNone  The MGMT_SET request message was handled successfully.
-     * @retval OT_ERROR_DROP  The MGMT_SET request message was dropped.
+     * @retval kErrorDrop  The MGMT_SET request message was dropped.
      *
      */
-    otError HandleSet(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
+    Error HandleSet(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 #endif
 
     DatasetLocal mLocal;
@@ -342,19 +342,19 @@ private:
     static void HandleCoapResponse(void *               aContext,
                                    otMessage *          aMessage,
                                    const otMessageInfo *aMessageInfo,
-                                   otError              aError);
+                                   Error                aError);
     void        HandleCoapResponse(void);
 
-    bool    IsActiveDataset(void) const { return GetType() == Dataset::kActive; }
+    bool  IsActiveDataset(void) const { return GetType() == Dataset::kActive; }
-    bool    IsPendingDataset(void) const { return GetType() == Dataset::kPending; }
+    bool  IsPendingDataset(void) const { return GetType() == Dataset::kPending; }
-    void    SignalDatasetChange(void) const;
+    void  SignalDatasetChange(void) const;
-    void    HandleDatasetUpdated(void);
+    void  HandleDatasetUpdated(void);
-    otError AppendDatasetToMessage(const Dataset::Info &aDatasetInfo, Message &aMessage) const;
+    Error AppendDatasetToMessage(const Dataset::Info &aDatasetInfo, Message &aMessage) const;
-    void    SendSet(void);
+    void  SendSet(void);
-    void    SendGetResponse(const Coap::Message &   aRequest,
+    void  SendGetResponse(const Coap::Message &   aRequest,
-                            const Ip6::MessageInfo &aMessageInfo,
+                          const Ip6::MessageInfo &aMessageInfo,
-                            uint8_t *               aTlvs,
+                          uint8_t *               aTlvs,
-                            uint8_t                 aLength) const;
+                          uint8_t                 aLength) const;
 
 #if OPENTHREAD_FTD
     void SendSetResponse(const Coap::Message &aRequest, const Ip6::MessageInfo &aMessageInfo, StateTlv::State aState);
@@ -430,29 +430,29 @@ public:
      * @param[in]  aLength     The length of the Operational Dataset.
      *
      */
-    otError Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
+    Error Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
 
     /**
      * This method sets the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDatasetInfo  The Operational Dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone            Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError Save(const Dataset::Info &aDatasetInfo) { return DatasetManager::Save(aDatasetInfo); }
+    Error Save(const Dataset::Info &aDatasetInfo) { return DatasetManager::Save(aDatasetInfo); }
 
     /**
      * This method sets the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone            Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError Save(const otOperationalDatasetTlvs &aDataset) { return DatasetManager::Save(aDataset); }
+    Error Save(const otOperationalDatasetTlvs &aDataset) { return DatasetManager::Save(aDataset); }
 
 #if OPENTHREAD_FTD
 
@@ -461,11 +461,11 @@ public:
      *
      * @param[out]  aDatasetInfo  The Operational Dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE    Successfully created a new Operational Dataset.
+     * @retval kErrorNone    Successfully created a new Operational Dataset.
-     * @retval OT_ERROR_FAILED  Failed to generate random values for new parameters.
+     * @retval kErrorFailed  Failed to generate random values for new parameters.
      *
      */
-    otError CreateNewNetwork(Dataset::Info &aDatasetInfo) { return aDatasetInfo.GenerateRandom(GetInstance()); }
+    Error CreateNewNetwork(Dataset::Info &aDatasetInfo) { return aDatasetInfo.GenerateRandom(GetInstance()); }
 
     /**
      * This method starts the Leader functions for maintaining the Active Operational Dataset.
@@ -482,12 +482,12 @@ public:
     /**
      * This method generate a default Active Operational Dataset.
      *
-     * @retval OT_ERROR_NONE           Successfully generated an Active Operational Dataset.
+     * @retval kErrorNone          Successfully generated an Active Operational Dataset.
-     * @retval OT_ERROR_ALREADY        A valid Active Operational Dataset already exists.
+     * @retval kErrorAlready       A valid Active Operational Dataset already exists.
-     * @retval OT_ERROR_INVALID_STATE  Device is not currently attached to a network.
+     * @retval kErrorInvalidState  Device is not currently attached to a network.
      *
      */
-    otError GenerateLocal(void);
+    Error GenerateLocal(void);
 #endif
 
 private:
@@ -543,11 +543,11 @@ public:
      *
      * @param[in]  aDatasetInfo  The Operational Dataset as `Dataset::Info`.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone            Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError Save(const Dataset::Info &aDatasetInfo);
+    Error Save(const Dataset::Info &aDatasetInfo);
 
     /**
      * This method saves the Operational Dataset in non-volatile memory.
@@ -556,11 +556,11 @@ public:
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE             Successfully saved the dataset.
+     * @retval kErrorNone            Successfully saved the dataset.
-     * @retval OT_ERROR_NOT_IMPLEMENTED  The platform does not implement settings functionality.
+     * @retval kErrorNotImplemented  The platform does not implement settings functionality.
      *
      */
-    otError Save(const otOperationalDatasetTlvs &aDataset);
+    Error Save(const otOperationalDatasetTlvs &aDataset);
 
     /**
      * This method sets the Operational Dataset for the partition.
@@ -575,18 +575,18 @@ public:
      * @param[in]  aLength     The length of the Operational Dataset.
      *
      */
-    otError Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
+    Error Save(const Timestamp &aTimestamp, const Message &aMessage, uint16_t aOffset, uint8_t aLength);
 
     /**
      * This method saves the Operational Dataset in non-volatile memory.
      *
      * @param[in]  aDataset  The Operational Dataset.
      *
-     * @retval OT_ERROR_NONE   Successfully applied configuration.
+     * @retval kErrorNone   Successfully applied configuration.
-     * @retval OT_ERROR_PARSE  The dataset has at least one TLV with invalid format.
+     * @retval kErrorParse  The dataset has at least one TLV with invalid format.
      *
      */
-    otError Save(const Dataset &aDataset);
+    Error Save(const Dataset &aDataset);
 
 #if OPENTHREAD_FTD
     /**