[common] add ClearAllBytes() template function (#9818)

This commit introduces the `ClearAllBytes<ObjectType>()` template
function to zero out all bytes within an object. This replaces
`memset(0)` calls in OT core modules, simplifying code and improving
safety by automatically using the correct object size.

src/cli/cli.cpp

@@ -163,7 +163,7 @@ Interpreter::Interpreter(Instance *aInstance, otCliOutputCallback aCallback, voi
 #if (OPENTHREAD_FTD || OPENTHREAD_MTD) && OPENTHREAD_CONFIG_CLI_REGISTER_IP6_RECV_CALLBACK
     otIp6SetReceiveCallback(GetInstancePtr(), &Interpreter::HandleIp6Receive, this);
 #endif
-    memset(&mUserCommands, 0, sizeof(mUserCommands));
+    ClearAllBytes(mUserCommands);
 
     OutputPrompt();
 }
@@ -2668,7 +2668,7 @@ template <> otError Interpreter::Process<Cmd("eidcache")>(Arg aArgs[])
     otCacheEntryIterator iterator;
     otCacheEntryInfo     entry;
 
-    memset(&iterator, 0, sizeof(iterator));
+    ClearAllBytes(iterator);
 
     while (true)
     {
@@ -4078,7 +4078,7 @@ template <> otError Interpreter::Process<Cmd("mode")>(Arg aArgs[])
     otError          error = OT_ERROR_NONE;
     otLinkModeConfig linkMode;
 
-    memset(&linkMode, 0, sizeof(otLinkModeConfig));
+    ClearAllBytes(linkMode);
 
     if (aArgs[0].IsEmpty())
     {
@@ -5662,7 +5662,7 @@ otError Interpreter::ParsePrefix(Arg aArgs[], otBorderRouterConfig &aConfig)
 {
     otError error = OT_ERROR_NONE;
 
-    memset(&aConfig, 0, sizeof(otBorderRouterConfig));
+    ClearAllBytes(aConfig);
 
     SuccessOrExit(error = aArgs[0].ParseAsIp6Prefix(aConfig.mPrefix));
     aArgs++;
@@ -6089,7 +6089,7 @@ otError Interpreter::ParseRoute(Arg aArgs[], otExternalRouteConfig &aConfig)
 {
     otError error = OT_ERROR_NONE;
 
-    memset(&aConfig, 0, sizeof(otExternalRouteConfig));
+    ClearAllBytes(aConfig);
 
     SuccessOrExit(error = aArgs[0].ParseAsIp6Prefix(aConfig.mPrefix));
     aArgs++;

src/cli/cli_coap.cpp

@@ -58,15 +58,15 @@ Coap::Coap(otInstance *aInstance, OutputImplementer &aOutputImplementer)
     , mBlockCount(1)
 #endif
 {
-    memset(&mResource, 0, sizeof(mResource));
+    ClearAllBytes(mResource);
 #if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE
-    memset(&mRequestAddr, 0, sizeof(mRequestAddr));
-    memset(&mSubscriberSock, 0, sizeof(mSubscriberSock));
-    memset(&mRequestToken, 0, sizeof(mRequestToken));
-    memset(&mSubscriberToken, 0, sizeof(mSubscriberToken));
-    memset(&mRequestUri, 0, sizeof(mRequestUri));
+    ClearAllBytes(mRequestAddr);
+    ClearAllBytes(mSubscriberSock);
+    ClearAllBytes(mRequestToken);
+    ClearAllBytes(mSubscriberToken);
+    ClearAllBytes(mRequestUri);
 #endif
-    memset(&mUriPath, 0, sizeof(mUriPath));
+    ClearAllBytes(mUriPath);
     strncpy(mResourceContent, "0", sizeof(mResourceContent));
     mResourceContent[sizeof(mResourceContent) - 1] = '\0';
 }
@@ -78,7 +78,7 @@ otError Coap::CancelResourceSubscription(void)
     otMessage    *message = nullptr;
     otMessageInfo messageInfo;
 
-    memset(&messageInfo, 0, sizeof(messageInfo));
+    ClearAllBytes(messageInfo);
     messageInfo.mPeerAddr = mRequestAddr;
     messageInfo.mPeerPort = OT_DEFAULT_COAP_PORT;
 
@@ -94,8 +94,8 @@ otError Coap::CancelResourceSubscription(void)
     SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, mRequestUri));
     SuccessOrExit(error = otCoapSendRequest(GetInstancePtr(), message, &messageInfo, &Coap::HandleResponse, this));
 
-    memset(&mRequestAddr, 0, sizeof(mRequestAddr));
-    memset(&mRequestUri, 0, sizeof(mRequestUri));
+    ClearAllBytes(mRequestAddr);
+    ClearAllBytes(mRequestUri);
     mRequestTokenLength = 0;
 
 exit:
@@ -110,7 +110,7 @@ exit:
 
 void Coap::CancelSubscriber(void)
 {
-    memset(&mSubscriberSock, 0, sizeof(mSubscriberSock));
+    ClearAllBytes(mSubscriberSock);
     mSubscriberTokenLength = 0;
 }
 #endif // OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE
@@ -207,7 +207,7 @@ template <> otError Coap::Process<Cmd("set")>(Arg aArgs[])
         if (mSubscriberTokenLength > 0)
         {
             // Notify the subscriber
-            memset(&messageInfo, 0, sizeof(messageInfo));
+            ClearAllBytes(messageInfo);
             messageInfo.mPeerAddr = mSubscriberSock.mAddress;
             messageInfo.mPeerPort = mSubscriberSock.mPort;
 
@@ -494,7 +494,7 @@ otError Coap::ProcessRequest(Arg aArgs[], otCoapCode aCoapCode)
         SuccessOrExit(error = otMessageAppend(message, aArgs[3].GetCString(), payloadLength));
     }
 
-    memset(&messageInfo, 0, sizeof(messageInfo));
+    ClearAllBytes(messageInfo);
     messageInfo.mPeerAddr = coapDestinationIp;
     messageInfo.mPeerPort = OT_DEFAULT_COAP_PORT;
 

src/cli/cli_coap_secure.cpp

@@ -56,10 +56,10 @@ CoapSecure::CoapSecure(otInstance *aInstance, OutputImplementer &aOutputImplemen
     , mBlockCount(1)
 #endif
 {
-    memset(&mResource, 0, sizeof(mResource));
-    memset(&mPsk, 0, sizeof(mPsk));
-    memset(&mPskId, 0, sizeof(mPskId));
-    memset(&mUriPath, 0, sizeof(mUriPath));
+    ClearAllBytes(mResource);
+    ClearAllBytes(mPsk);
+    ClearAllBytes(mPskId);
+    ClearAllBytes(mUriPath);
     strncpy(mResourceContent, "0", sizeof(mResourceContent));
     mResourceContent[sizeof(mResourceContent) - 1] = '\0';
 }
@@ -398,7 +398,7 @@ template <> otError CoapSecure::Process<Cmd("connect")>(Arg aArgs[])
     otError    error;
     otSockAddr sockaddr;
 
-    memset(&sockaddr, 0, sizeof(sockaddr));
+    ClearAllBytes(sockaddr);
     SuccessOrExit(error = aArgs[0].ParseAsIp6Address(sockaddr.mAddress));
     sockaddr.mPort = OT_DEFAULT_COAP_SECURE_PORT;
 

src/cli/cli_commissioner.cpp

@@ -186,7 +186,7 @@ template <> otError Commissioner::Process<Cmd("joiner")>(Arg aArgs[])
 
     VerifyOrExit(!aArgs[1].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
 
-    memset(&discerner, 0, sizeof(discerner));
+    ClearAllBytes(discerner);
 
     if (aArgs[1] == "*")
     {
@@ -383,7 +383,7 @@ template <> otError Commissioner::Process<Cmd("mgmtset")>(Arg aArgs[])
 
     VerifyOrExit(!aArgs[0].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
 
-    memset(&dataset, 0, sizeof(dataset));
+    ClearAllBytes(dataset);
 
     for (; !aArgs->IsEmpty(); aArgs++)
     {

src/cli/cli_dataset.cpp

@@ -526,7 +526,7 @@ otError Dataset::ProcessCommand(const ComponentMapper &aMapper, Arg aArgs[])
     }
     else
     {
-        memset(&dataset, 0, sizeof(dataset));
+        ClearAllBytes(dataset);
         SuccessOrExit(error = (this->*aMapper.mParse)(aArgs, dataset));
         dataset.mComponents.*aMapper.mIsPresentPtr = true;
         SuccessOrExit(error = otDatasetUpdateTlvs(&dataset, &sDatasetTlvs));
@@ -716,7 +716,7 @@ template <> otError Dataset::Process<Cmd("clear")>(Arg aArgs[])
 {
     OT_UNUSED_VARIABLE(aArgs);
 
-    memset(&sDatasetTlvs, 0, sizeof(sDatasetTlvs));
+    ClearAllBytes(sDatasetTlvs);
     return OT_ERROR_NONE;
 }
 
@@ -765,7 +765,7 @@ template <> otError Dataset::Process<Cmd("mgmtsetcommand")>(Arg aArgs[])
     uint8_t              tlvs[128];
     uint8_t              tlvsLength = 0;
 
-    memset(&dataset, 0, sizeof(dataset));
+    ClearAllBytes(dataset);
 
     for (Arg *arg = &aArgs[1]; !arg->IsEmpty();)
     {
@@ -853,7 +853,7 @@ template <> otError Dataset::Process<Cmd("mgmtgetcommand")>(Arg aArgs[])
     bool                           destAddrSpecified = false;
     otIp6Address                   address;
 
-    memset(&datasetComponents, 0, sizeof(datasetComponents));
+    ClearAllBytes(datasetComponents);
 
     for (Arg *arg = &aArgs[1]; !arg->IsEmpty(); arg++)
     {
@@ -1003,7 +1003,7 @@ otError Dataset::ParseSecurityPolicy(otSecurityPolicy &aSecurityPolicy, Arg *&aA
     otSecurityPolicy policy;
     uint8_t          versionThreshold;
 
-    memset(&policy, 0, sizeof(policy));
+    ClearAllBytes(policy);
 
     SuccessOrExit(error = aArgs->ParseAsUint16(policy.mRotationTime));
     aArgs++;

src/cli/cli_dns.cpp

@@ -418,7 +418,7 @@ otError Dns::GetDnsConfig(Arg aArgs[], otDnsQueryConfig *&aConfig)
     bool    recursionDesired;
     bool    nat64SynthesizedAddress;
 
-    memset(aConfig, 0, sizeof(otDnsQueryConfig));
+    ClearAllBytes(*aConfig);
 
     VerifyOrExit(!aArgs[0].IsEmpty(), aConfig = nullptr);
 

src/cli/cli_joiner.cpp

@@ -78,7 +78,7 @@ template <> otError Joiner::Process<Cmd("discerner")>(Arg aArgs[])
     {
         otJoinerDiscerner discerner;
 
-        memset(&discerner, 0, sizeof(discerner));
+        ClearAllBytes(discerner);
 
         /**
          * @cli joiner discerner clear

src/cli/cli_link_metrics.cpp

@@ -138,7 +138,7 @@ template <> otError LinkMetrics::Process<Cmd("mgmt")>(Arg aArgs[])
 
     SuccessOrExit(error = aArgs[0].ParseAsIp6Address(address));
 
-    memset(&seriesFlags, 0, sizeof(otLinkMetricsSeriesFlags));
+    ClearAllBytes(seriesFlags);
 
     /**
      * @cli linkmetrics mgmt forward
@@ -171,7 +171,7 @@ template <> otError LinkMetrics::Process<Cmd("mgmt")>(Arg aArgs[])
         uint8_t       seriesId;
         otLinkMetrics linkMetrics;
 
-        memset(&linkMetrics, 0, sizeof(otLinkMetrics));
+        ClearAllBytes(linkMetrics);
         SuccessOrExit(error = aArgs[2].ParseAsUint8(seriesId));
         VerifyOrExit(!aArgs[3].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
 
@@ -368,7 +368,7 @@ otError LinkMetrics::ParseLinkMetricsFlags(otLinkMetrics &aLinkMetrics, const Ar
 
     VerifyOrExit(!aFlags.IsEmpty(), error = OT_ERROR_INVALID_ARGS);
 
-    memset(&aLinkMetrics, 0, sizeof(aLinkMetrics));
+    ClearAllBytes(aLinkMetrics);
 
     for (const char *arg = aFlags.GetCString(); *arg != '\0'; arg++)
     {

src/cli/cli_output.hpp

@@ -45,6 +45,7 @@
 #include "common/binary_search.hpp"
 #include "common/num_utils.hpp"
 #include "common/string.hpp"
+#include "common/type_traits.hpp"
 #include "utils/parse_cmdline.hpp"
 
 namespace ot {
@@ -527,6 +528,21 @@ public:
         }
     }
 
+    /**
+     * Clears (sets to zero) all bytes of a given object.
+     *
+     * @tparam ObjectType    The object type.
+     *
+     * @param[in] aObject    A reference to the object of type `ObjectType` to clear all its bytes.
+     *
+     */
+    template <typename ObjectType> static void ClearAllBytes(ObjectType &aObject)
+    {
+        static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer");
+
+        memset(reinterpret_cast<void *>(&aObject), 0, sizeof(ObjectType));
+    }
+
 protected:
     void OutputFormatV(const char *aFormat, va_list aArguments);
 

src/cli/cli_ping.cpp

@@ -78,7 +78,7 @@ otError PingSender::Process(Arg aArgs[])
         aArgs++;
     }
 
-    memset(&config, 0, sizeof(config));
+    ClearAllBytes(config);
 
     if (aArgs[0] == "-I")
     {

src/cli/cli_tcp.cpp

@@ -219,7 +219,7 @@ template <> otError TcpExample::Process<Cmd("init")>(Arg aArgs[])
     {
         otTcpEndpointInitializeArgs endpointArgs;
 
-        memset(&endpointArgs, 0x00, sizeof(endpointArgs));
+        ClearAllBytes(endpointArgs);
         endpointArgs.mEstablishedCallback = HandleTcpEstablishedCallback;
         if (mUseCircularSendBuffer)
         {
@@ -241,7 +241,7 @@ template <> otError TcpExample::Process<Cmd("init")>(Arg aArgs[])
     {
         otTcpListenerInitializeArgs listenerArgs;
 
-        memset(&listenerArgs, 0x00, sizeof(listenerArgs));
+        ClearAllBytes(listenerArgs);
         listenerArgs.mAcceptReadyCallback = HandleTcpAcceptReadyCallback;
         listenerArgs.mAcceptDoneCallback  = HandleTcpAcceptDoneCallback;
         listenerArgs.mContext             = this;

src/cli/cli_udp.cpp

@@ -47,7 +47,7 @@ UdpExample::UdpExample(otInstance *aInstance, OutputImplementer &aOutputImplemen
     : Output(aInstance, aOutputImplementer)
     , mLinkSecurityEnabled(true)
 {
-    memset(&mSocket, 0, sizeof(mSocket));
+    ClearAllBytes(mSocket);
 }
 
 /**
@@ -258,7 +258,7 @@ template <> otError UdpExample::Process<Cmd("send")>(Arg aArgs[])
     otMessageInfo     messageInfo;
     otMessageSettings messageSettings = {mLinkSecurityEnabled, OT_MESSAGE_PRIORITY_NORMAL};
 
-    memset(&messageInfo, 0, sizeof(messageInfo));
+    ClearAllBytes(messageInfo);
 
     // Possible argument formats:
     //

src/core/common/clearable.hpp

@@ -38,8 +38,25 @@
 
 #include <string.h>
 
+#include "common/type_traits.hpp"
+
 namespace ot {
 
+/**
+ * Clears (sets to zero) all bytes of a given object.
+ *
+ * @tparam ObjectType    The object type.
+ *
+ * @param[in] aObject    A reference to the object of type `ObjectType` to clear all its bytes.
+ *
+ */
+template <typename ObjectType> void ClearAllBytes(ObjectType &aObject)
+{
+    static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer");
+
+    memset(reinterpret_cast<void *>(&aObject), 0, sizeof(ObjectType));
+}
+
 /**
  * Defines a `Clearable` object which provides `Clear()` method.
  *
@@ -52,7 +69,7 @@ namespace ot {
 template <typename Type> class Clearable
 {
 public:
-    void Clear(void) { memset(reinterpret_cast<void *>(static_cast<Type *>(this)), 0, sizeof(Type)); }
+    void Clear(void) { ClearAllBytes<Type>(*static_cast<Type *>(this)); }
 };
 
 } // namespace ot

src/core/common/message.cpp

@@ -75,7 +75,7 @@ Message *MessagePool::Allocate(Message::Type aType, uint16_t aReserveHeader, con
 
     VerifyOrExit((message = static_cast<Message *>(NewBuffer(aSettings.GetPriority()))) != nullptr);
 
-    memset(message, 0, sizeof(*message));
+    ClearAllBytes(*message);
     message->SetMessagePool(this);
     message->SetType(aType);
     message->SetReserved(aReserveHeader);

src/core/common/settings.hpp

@@ -417,7 +417,7 @@ public:
          */
         void Init(void)
         {
-            memset(this, 0, sizeof(*this));
+            ClearAllBytes(*this);
             SetVersion(kThreadVersion1p1);
         }
 
@@ -784,7 +784,7 @@ public:
          * Initializes the `BorderAgentId` object.
          *
          */
-        void Init(void) { memset(&mId, 0, sizeof(mId)); }
+        void Init(void) { ClearAllBytes(mId); }
 
         /**
          * Returns the Border Agent ID.

src/core/diags/factory_diags.hpp

@@ -42,6 +42,7 @@
 
 #include <openthread/platform/radio.h>
 
+#include "common/clearable.hpp"
 #include "common/error.hpp"
 #include "common/locator.hpp"
 #include "common/non_copyable.hpp"
@@ -131,10 +132,8 @@ private:
         Error (Diags::*mCommand)(uint8_t aArgsLength, char *aArgs[], char *aOutput, size_t aOutputMaxLen);
     };
 
-    struct Stats
+    struct Stats : public Clearable<Stats>
     {
-        void Clear(void) { memset(this, 0, sizeof(*this)); }
-
         uint32_t mReceivedPackets;
         uint32_t mSentPackets;
         int8_t   mFirstRssi;

src/core/mac/mac.cpp

@@ -234,7 +234,7 @@ Error Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, ActiveSc
     uint16_t             payloadLength;
 #endif
 
-    memset(&aResult, 0, sizeof(ActiveScanResult));
+    ClearAllBytes(aResult);
 
     VerifyOrExit(aBeaconFrame != nullptr, error = kErrorInvalidArgs);
 
@@ -2153,7 +2153,7 @@ const uint32_t *Mac::GetIndirectRetrySuccessHistogram(uint8_t &aNumberOfEntries)
 }
 #endif
 
-void Mac::ResetRetrySuccessHistogram() { memset(&mRetryHistogram, 0, sizeof(mRetryHistogram)); }
+void Mac::ResetRetrySuccessHistogram() { ClearAllBytes(mRetryHistogram); }
 #endif // OPENTHREAD_CONFIG_MAC_RETRY_SUCCESS_HISTOGRAM_ENABLE
 
 uint8_t Mac::ComputeLinkMargin(int8_t aRss) const { return ot::ComputeLinkMargin(GetNoiseFloor(), aRss); }

src/core/mac/mac.hpp

@@ -39,6 +39,7 @@
 #include <openthread/platform/radio.h>
 #include <openthread/platform/time.h>
 
+#include "common/clearable.hpp"
 #include "common/locator.hpp"
 #include "common/log.hpp"
 #include "common/non_copyable.hpp"
@@ -496,7 +497,7 @@ public:
      * Resets mac counters
      *
      */
-    void ResetCounters(void) { memset(&mCounters, 0, sizeof(mCounters)); }
+    void ResetCounters(void) { ClearAllBytes(mCounters); }
 
     /**
      * Returns the MAC counter.

src/core/mac/mac_frame.cpp

@@ -1385,7 +1385,7 @@ void TxFrame::GenerateImmAck(const RxFrame &aFrame, bool aIsFramePending)
     uint16_t fcf = static_cast<uint16_t>(kTypeAck) | aFrame.GetVersion();
 
     mChannel = aFrame.mChannel;
-    memset(&mInfo.mTxInfo, 0, sizeof(mInfo.mTxInfo));
+    ClearAllBytes(mInfo.mTxInfo);
 
     if (aIsFramePending)
     {
@@ -1449,7 +1449,7 @@ Error TxFrame::GenerateEnhAck(const RxFrame &aRxFrame, bool aIsFramePending, con
     // Prepare the ack frame
 
     mChannel = aRxFrame.mChannel;
-    memset(&mInfo.mTxInfo, 0, sizeof(mInfo.mTxInfo));
+    ClearAllBytes(mInfo.mTxInfo);
 
     InitMacHeader(kTypeAck, kVersion2015, addrs, panIds, static_cast<SecurityLevel>(securityLevel),
                   static_cast<KeyIdMode>(keyIdMode));

src/core/meshcop/commissioner.cpp

@@ -72,7 +72,7 @@ Commissioner::Commissioner(Instance &aInstance)
     , mPanIdQuery(aInstance)
     , mState(kStateDisabled)
 {
-    memset(reinterpret_cast<void *>(mJoiners), 0, sizeof(mJoiners));
+    ClearAllBytes(mJoiners);
 
     mCommissionerAloc.InitAsThreadOriginMeshLocal();
     mCommissionerAloc.mPreferred = true;
@@ -476,7 +476,7 @@ exit:
 
 void Commissioner::Joiner::CopyToJoinerInfo(otJoinerInfo &aJoiner) const
 {
-    memset(&aJoiner, 0, sizeof(aJoiner));
+    ClearAllBytes(aJoiner);
 
     switch (mType)
     {

src/core/meshcop/dataset.cpp

@@ -159,7 +159,7 @@ Dataset::Dataset(void)
     : mUpdateTime(0)
     , mLength(0)
 {
-    memset(mTlvs, 0, sizeof(mTlvs));
+    ClearAllBytes(mTlvs);
 }
 
 void Dataset::Clear(void) { mLength = 0; }

src/core/meshcop/dataset_local.cpp

@@ -152,7 +152,7 @@ Error DatasetLocal::Read(otOperationalDatasetTlvs &aDataset) const
     Dataset dataset;
     Error   error;
 
-    memset(&aDataset, 0, sizeof(aDataset));
+    ClearAllBytes(aDataset);
 
     SuccessOrExit(error = Read(dataset));
     dataset.ConvertTo(aDataset);

src/core/meshcop/joiner.cpp

@@ -68,7 +68,7 @@ Joiner::Joiner(Instance &aInstance)
 {
     SetIdFromIeeeEui64();
     mDiscerner.Clear();
-    memset(mJoinerRouters, 0, sizeof(mJoinerRouters));
+    ClearAllBytes(mJoinerRouters);
 }
 
 void Joiner::SetIdFromIeeeEui64(void)

src/core/meshcop/meshcop.cpp

@@ -34,6 +34,7 @@
 
 #include "meshcop.hpp"
 
+#include "common/clearable.hpp"
 #include "common/crc16.hpp"
 #include "common/debug.hpp"
 #include "common/locator_getters.hpp"
@@ -191,7 +192,7 @@ void SteeringData::Init(uint8_t aLength)
 {
     OT_ASSERT(aLength <= kMaxLength);
     mLength = aLength;
-    memset(m8, 0, sizeof(m8));
+    ClearAllBytes(m8);
 }
 
 void SteeringData::SetToPermitAllJoiners(void)
@@ -324,7 +325,7 @@ Error GeneratePskc(const char          *aPassPhrase,
                      (networkNameLen <= OT_NETWORK_NAME_MAX_SIZE),
                  error = kErrorInvalidArgs);
 
-    memset(salt, 0, sizeof(salt));
+    ClearAllBytes(salt);
     memcpy(salt, saltPrefix, sizeof(saltPrefix) - 1);
     saltLen += static_cast<uint16_t>(sizeof(saltPrefix) - 1);
 

src/core/meshcop/secure_transport.cpp

@@ -41,6 +41,7 @@
 #include <openthread/platform/radio.h>
 
 #include "common/as_core_type.hpp"
+#include "common/clearable.hpp"
 #include "common/code_utils.hpp"
 #include "common/debug.hpp"
 #include "common/encoding.hpp"
@@ -105,19 +106,19 @@ SecureTransport::SecureTransport(Instance &aInstance, bool aLayerTwoSecurity, bo
     mOwnCertLength    = 0;
     mPrivateKeySrc    = nullptr;
     mPrivateKeyLength = 0;
-    memset(&mCaChain, 0, sizeof(mCaChain));
-    memset(&mOwnCert, 0, sizeof(mOwnCert));
-    memset(&mPrivateKey, 0, sizeof(mPrivateKey));
+    ClearAllBytes(mCaChain);
+    ClearAllBytes(mOwnCert);
+    ClearAllBytes(mPrivateKey);
 #endif
 #endif
 
-    memset(mCipherSuites, 0, sizeof(mCipherSuites));
-    memset(mPsk, 0, sizeof(mPsk));
-    memset(&mSsl, 0, sizeof(mSsl));
-    memset(&mConf, 0, sizeof(mConf));
+    ClearAllBytes(mCipherSuites);
+    ClearAllBytes(mPsk);
+    ClearAllBytes(mSsl);
+    ClearAllBytes(mConf);
 
 #ifdef MBEDTLS_SSL_COOKIE_C
-    memset(&mCookieCtx, 0, sizeof(mCookieCtx));
+    ClearAllBytes(mCookieCtx);
 #endif
 }
 

src/core/net/dhcp6_client.cpp

@@ -57,7 +57,7 @@ Client::Client(Instance &aInstance)
     , mStartTime(0)
     , mIdentityAssociationCurrent(nullptr)
 {
-    memset(mIdentityAssociations, 0, sizeof(mIdentityAssociations));
+    ClearAllBytes(mIdentityAssociations);
 }
 
 bool Client::MatchNetifAddressWithPrefix(const Ip6::Netif::UnicastAddress &aNetifAddress, const Ip6::Prefix &aIp6Prefix)

src/core/net/dhcp6_server.cpp

@@ -56,7 +56,7 @@ Server::Server(Instance &aInstance)
     , mPrefixAgentsCount(0)
     , mPrefixAgentsMask(0)
 {
-    memset(mPrefixAgents, 0, sizeof(mPrefixAgents));
+    ClearAllBytes(mPrefixAgents);
 }
 
 Error Server::UpdateService(void)

src/core/net/dns_client.cpp

@@ -799,7 +799,7 @@ Error Client::InitTcpSocket(void)
     Error                       error;
     otTcpEndpointInitializeArgs endpointArgs;
 
-    memset(&endpointArgs, 0x00, sizeof(endpointArgs));
+    ClearAllBytes(endpointArgs);
     endpointArgs.mSendDoneCallback         = HandleTcpSendDoneCallback;
     endpointArgs.mEstablishedCallback      = HandleTcpEstablishedCallback;
     endpointArgs.mReceiveAvailableCallback = HandleTcpReceiveAvailableCallback;
@@ -1634,7 +1634,7 @@ void Client::ResolveHostAddressIfNeeded(Query &aQuery, const Message &aResponseM
 
     PopulateResponse(response, aQuery, aResponseMessage);
 
-    memset(&serviceInfo, 0, sizeof(serviceInfo));
+    ClearAllBytes(serviceInfo);
     serviceInfo.mHostNameBuffer     = hostName;
     serviceInfo.mHostNameBufferSize = sizeof(hostName);
     SuccessOrExit(response.ReadServiceInfo(Response::kAnswerSection, Name(aQuery, kNameOffsetInQuery), serviceInfo));

src/core/net/ip6.hpp

@@ -350,7 +350,7 @@ public:
      * Resets the Border Routing counters.
      *
      */
-    void ResetBorderRoutingCounters(void) { memset(&mBorderRoutingCounters, 0, sizeof(mBorderRoutingCounters)); }
+    void ResetBorderRoutingCounters(void) { ClearAllBytes(mBorderRoutingCounters); }
 #endif
 
 private:

src/core/net/ip6_mpl.cpp

@@ -52,7 +52,7 @@ Mpl::Mpl(Instance &aInstance)
     , mRetransmissionTimer(aInstance)
 #endif
 {
-    memset(mSeedSet, 0, sizeof(mSeedSet));
+    ClearAllBytes(mSeedSet);
 }
 
 void MplOption::Init(SeedIdLength aSeedIdLength)

src/core/net/tcp6.cpp

@@ -81,7 +81,7 @@ Error Tcp::Endpoint::Initialize(Instance &aInstance, const otTcpEndpointInitiali
     Error         error;
     struct tcpcb &tp = GetTcb();
 
-    memset(&tp, 0x00, sizeof(tp));
+    ClearAllBytes(tp);
 
     SuccessOrExit(error = aInstance.Get<Tcp>().mEndpoints.Add(*this));
 
@@ -92,8 +92,8 @@ Error Tcp::Endpoint::Initialize(Instance &aInstance, const otTcpEndpointInitiali
     mReceiveAvailableCallback = aArgs.mReceiveAvailableCallback;
     mDisconnectedCallback     = aArgs.mDisconnectedCallback;
 
-    memset(mTimers, 0x00, sizeof(mTimers));
-    memset(&mSockAddr, 0x00, sizeof(mSockAddr));
+    ClearAllBytes(mTimers);
+    ClearAllBytes(mSockAddr);
     mPendingCallbacks = 0;
 
     /*
@@ -549,7 +549,7 @@ Error Tcp::Listener::Initialize(Instance &aInstance, const otTcpListenerInitiali
     mAcceptReadyCallback = aArgs.mAcceptReadyCallback;
     mAcceptDoneCallback  = aArgs.mAcceptDoneCallback;
 
-    memset(tpl, 0x00, sizeof(struct tcpcb_listen));
+    ClearAllBytes(*tpl);
     tpl->instance = &aInstance;
 
 exit:
@@ -579,7 +579,7 @@ Error Tcp::Listener::StopListening(void)
 {
     struct tcpcb_listen *tpl = &GetTcbListen();
 
-    memset(&tpl->laddr, 0x00, sizeof(tpl->laddr));
+    ClearAllBytes(tpl->laddr);
     tpl->lport   = 0;
     tpl->t_state = TCP6S_CLOSED;
     return kErrorNone;
@@ -670,7 +670,7 @@ Error Tcp::HandleMessage(ot::Ip6::Header &aIp6Header, Message &aMessage, Message
         otLinkedBuffer *priorHead    = lbuf_head(&tp->sendbuf);
         size_t          priorBacklog = endpoint->GetSendBufferBytes() - endpoint->GetInFlightBytes();
 
-        memset(&sig, 0x00, sizeof(sig));
+        ClearAllBytes(sig);
         nextAction = tcp_input(ip6Header, tcpHeader, &aMessage, tp, nullptr, &sig);
         if (nextAction != RELOOKUP_REQUIRED)
         {
@@ -685,7 +685,7 @@ Error Tcp::HandleMessage(ot::Ip6::Header &aIp6Header, Message &aMessage, Message
     {
         struct tcpcb_listen *tpl = &listener->GetTcbListen();
 
-        memset(&sig, 0x00, sizeof(sig));
+        ClearAllBytes(sig);
         nextAction = tcp_input(ip6Header, tcpHeader, &aMessage, nullptr, tpl, &sig);
         OT_ASSERT(nextAction != RELOOKUP_REQUIRED);
         if (sig.accepted_connection != nullptr)

src/core/radio/trel_link.cpp

@@ -55,9 +55,9 @@ Link::Link(Instance &aInstance)
     , mTimer(aInstance)
     , mInterface(aInstance)
 {
-    memset(&mTxFrame, 0, sizeof(mTxFrame));
-    memset(&mRxFrame, 0, sizeof(mRxFrame));
-    memset(mAckFrameBuffer, 0, sizeof(mAckFrameBuffer));
+    ClearAllBytes(mTxFrame);
+    ClearAllBytes(mRxFrame);
+    ClearAllBytes(mAckFrameBuffer);
 
     mTxFrame.mPsdu = &mTxPacketBuffer[kMaxHeaderSize];
     mTxFrame.SetLength(0);

src/core/thread/child.cpp

@@ -112,14 +112,14 @@ void Child::Clear(void)
 {
     Instance &instance = GetInstance();
 
-    memset(reinterpret_cast<void *>(this), 0, sizeof(Child));
+    ClearAllBytes(*this);
     Init(instance);
 }
 
 void Child::ClearIp6Addresses(void)
 {
     mMeshLocalIid.Clear();
-    memset(mIp6Address, 0, sizeof(mIp6Address));
+    ClearAllBytes(mIp6Address);
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_TMF_PROXY_MLR_ENABLE
     mMlrToRegisterMask.Clear();
     mMlrRegisteredMask.Clear();

src/core/thread/discover_scanner.cpp

@@ -325,7 +325,7 @@ void DiscoverScanner::HandleDiscoveryResponse(Mle::RxInfo &aRxInfo) const
     // Find MLE Discovery TLV
     SuccessOrExit(error = Tlv::FindTlvValueStartEndOffsets(aRxInfo.mMessage, Tlv::kDiscovery, offset, end));
 
-    memset(&result, 0, sizeof(result));
+    ClearAllBytes(result);
     result.mDiscover = true;
     result.mPanId    = linkInfo->mPanId;
     result.mChannel  = linkInfo->mChannel;

src/core/thread/mesh_forwarder.hpp

@@ -306,7 +306,7 @@ public:
      * Resets the IP level counters.
      *
      */
-    void ResetCounters(void) { memset(&mIpCounters, 0, sizeof(mIpCounters)); }
+    void ResetCounters(void) { ClearAllBytes(mIpCounters); }
 
 #if OPENTHREAD_CONFIG_TX_QUEUE_STATISTICS_ENABLE
     /**

src/core/thread/mle.cpp

@@ -265,7 +265,7 @@ exit:
 
 void Mle::ResetCounters(void)
 {
-    memset(&mCounters, 0, sizeof(mCounters));
+    ClearAllBytes(mCounters);
 #if OPENTHREAD_CONFIG_UPTIME_ENABLE
     mLastUpdatedTimestamp = Get<Uptime>().GetUptime();
 #endif
@@ -5097,7 +5097,7 @@ void Mle::ParentCandidate::Clear(void)
 {
     Instance &instance = GetInstance();
 
-    memset(reinterpret_cast<void *>(this), 0, sizeof(ParentCandidate));
+    ClearAllBytes(*this);
     Init(instance);
 }
 

src/core/thread/mle_tlvs.cpp

@@ -33,6 +33,7 @@
 
 #include "mle_tlvs.hpp"
 
+#include "common/clearable.hpp"
 #include "common/code_utils.hpp"
 #include "common/numeric_limits.hpp"
 #include "radio/radio.hpp"
@@ -47,7 +48,7 @@ void RouteTlv::Init(void)
     SetType(kRoute);
     SetLength(sizeof(*this) - sizeof(Tlv));
     mRouterIdMask.Clear();
-    memset(mRouteData, 0, sizeof(mRouteData));
+    ClearAllBytes(mRouteData);
 }
 
 bool RouteTlv::IsValid(void) const

src/core/thread/mle_types.hpp

@@ -434,15 +434,9 @@ public:
 };
 
 OT_TOOL_PACKED_BEGIN
-class RouterIdSet : public Equatable<RouterIdSet>
+class RouterIdSet : public Equatable<RouterIdSet>, public Clearable<RouterIdSet>
 {
 public:
-    /**
-     * Clears the Router Id Set.
-     *
-     */
-    void Clear(void) { memset(mRouterIdSet, 0, sizeof(mRouterIdSet)); }
-
     /**
      * Indicates whether or not a Router ID bit is set.
      *

src/core/thread/network_diagnostic.cpp

@@ -212,7 +212,7 @@ Error Server::AppendMacCounters(Message &aMessage)
     MacCountersTlv       tlv;
     const otMacCounters &counters = Get<Mac::Mac>().GetCounters();
 
-    memset(&tlv, 0, sizeof(tlv));
+    ClearAllBytes(tlv);
 
     tlv.Init();
     tlv.SetIfInUnknownProtos(counters.mRxOther);

src/core/thread/radio_selector.cpp

@@ -63,7 +63,7 @@ RadioSelector::RadioSelector(Instance &aInstance)
 
 void RadioSelector::NeighborInfo::PopulateMultiRadioInfo(MultiRadioInfo &aInfo)
 {
-    memset(&aInfo, 0, sizeof(MultiRadioInfo));
+    ClearAllBytes(aInfo);
 
 #if OPENTHREAD_CONFIG_RADIO_LINK_IEEE_802_15_4_ENABLE
     if (GetSupportedRadioTypes().Contains(Mac::kRadioTypeIeee802154))

src/core/thread/router.cpp

@@ -71,7 +71,7 @@ void Router::Clear(void)
 {
     Instance &instance = GetInstance();
 
-    memset(reinterpret_cast<void *>(this), 0, sizeof(Router));
+    ClearAllBytes(*this);
     Init(instance);
 }
 
@@ -92,7 +92,7 @@ void Parent::Clear(void)
 {
     Instance &instance = GetInstance();
 
-    memset(reinterpret_cast<void *>(this), 0, sizeof(Parent));
+    ClearAllBytes(*this);
     Init(instance);
 }
 

src/core/thread/router_table.hpp

@@ -465,7 +465,7 @@ private:
     void HandleTableChanged(void);
     void LogRouteTable(void) const;
 
-    class RouterIdMap
+    class RouterIdMap : public Clearable<RouterIdMap>
     {
     public:
         // The `RouterIdMap` tracks which Router IDs are allocated.
@@ -474,7 +474,6 @@ private:
         // remaining reuse delay time (in seconds).
 
         RouterIdMap(void) { Clear(); }
-        void    Clear(void) { memset(mIndexes, 0, sizeof(mIndexes)); }
         bool    IsAllocated(uint8_t aRouterId) const { return (mIndexes[aRouterId] & kAllocatedFlag); }
         uint8_t GetIndex(uint8_t aRouterId) const { return (mIndexes[aRouterId] & kIndexMask); }
         void    SetIndex(uint8_t aRouterId, uint8_t aIndex) { mIndexes[aRouterId] = kAllocatedFlag | aIndex; }

src/core/utils/channel_monitor.cpp

@@ -66,7 +66,7 @@ ChannelMonitor::ChannelMonitor(Instance &aInstance)
     , mSampleCount(0)
     , mTimer(aInstance)
 {
-    memset(mChannelOccupancy, 0, sizeof(mChannelOccupancy));
+    ClearAllBytes(mChannelOccupancy);
 }
 
 Error ChannelMonitor::Start(void)
@@ -98,7 +98,7 @@ void ChannelMonitor::Clear(void)
 {
     mChannelMaskIndex = 0;
     mSampleCount      = 0;
-    memset(mChannelOccupancy, 0, sizeof(mChannelOccupancy));
+    ClearAllBytes(mChannelOccupancy);
 
     LogDebg("Clearing data");
 }

src/core/utils/history_tracker.cpp

@@ -61,7 +61,7 @@ HistoryTracker::HistoryTracker(Instance &aInstance)
     mTimer.Start(kAgeCheckPeriod);
 
 #if OPENTHREAD_FTD && (OPENTHREAD_CONFIG_HISTORY_TRACKER_ROUTER_LIST_SIZE > 0)
-    memset(mRouterEntries, 0, sizeof(mRouterEntries));
+    ClearAllBytes(mRouterEntries);
 #endif
 }
 

src/core/utils/slaac_address.cpp

@@ -56,7 +56,7 @@ Slaac::Slaac(Instance &aInstance)
     , mEnabled(true)
     , mFilter(nullptr)
 {
-    memset(mAddresses, 0, sizeof(mAddresses));
+    ClearAllBytes(mAddresses);
 }
 
 void Slaac::Enable(void)