[posix] unify the infra netif and backbone netif (#9638)

This commit refactors the code to unify the concept of 'Infrastructure
network interface' (which is for border routing) and 'backbone network
interface' (which is for backbone router). From now on they will both
be referred as 'infrastructure network interface'. In general border
routing and backbone router should be using the same infrastructure
network interface so I made this change.

This commit removes the `posix/platform/backbone.cpp` source file and
put its functionality in `posix/platform/infra_if.cpp`. Previously
`backbone.cpp` maintained its own variables `gBackboneNetifName` and
`gBackboneNetifIndex` which are redundant compared to the ones
maintained at `infra_if.cpp`. I removed these variables and changed
the references to use `otSysGetInfraNetifName` and
`otSysGetInfraNetifIndex` accordingly.

src/posix/platform/CMakeLists.txt

@@ -124,7 +124,6 @@ endif()
 
 add_library(openthread-posix
     alarm.cpp
-    backbone.cpp
     backtrace.cpp
     configuration.cpp
     config_file.cpp

src/posix/platform/backbone.cpp

@@ -1,101 +0,0 @@
-/*
- *  Copyright (c) 2020, 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 platform Backbone interface management on Linux.
- */
-
-#include "openthread-posix-config.h"
-
-#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-
-#include "multicast_routing.hpp"
-#include "platform-posix.h"
-#include "common/code_utils.hpp"
-#include "posix/platform/mainloop.hpp"
-
-char         gBackboneNetifName[IFNAMSIZ] = "";
-unsigned int gBackboneNetifIndex          = 0;
-#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
-static ot::Posix::MulticastRoutingManager sMulticastRoutingManager;
-#endif
-
-void platformBackboneInit(const char *aInterfaceName)
-{
-    if (aInterfaceName == nullptr || aInterfaceName[0] == '\0')
-    {
-        otLogWarnPlat("Backbone Router feature is disabled: infra/backbone interface is missing");
-        ExitNow();
-    }
-
-    VerifyOrDie(strnlen(aInterfaceName, sizeof(gBackboneNetifName)) < sizeof(gBackboneNetifName),
-                OT_EXIT_INVALID_ARGUMENTS);
-    strcpy(gBackboneNetifName, aInterfaceName);
-
-    gBackboneNetifIndex = if_nametoindex(gBackboneNetifName);
-    VerifyOrDie(gBackboneNetifIndex > 0, OT_EXIT_FAILURE);
-
-    otLogInfoPlat("Backbone interface is configured to %s (%d)", gBackboneNetifName, gBackboneNetifIndex);
-
-exit:
-    return;
-}
-
-void platformBackboneSetUp(void)
-{
-#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
-    sMulticastRoutingManager.SetUp();
-#endif
-}
-
-void platformBackboneTearDown(void)
-{
-#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
-    sMulticastRoutingManager.TearDown();
-#endif
-}
-
-void platformBackboneDeinit(void)
-{
-    gBackboneNetifIndex = 0;
-
-    memset(gBackboneNetifName, 0, sizeof(gBackboneNetifName));
-}
-
-void platformBackboneStateChange(otInstance *aInstance, otChangedFlags aFlags)
-{
-    OT_UNUSED_VARIABLE(aInstance);
-    OT_UNUSED_VARIABLE(aFlags);
-
-#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
-    sMulticastRoutingManager.HandleStateChange(aInstance, aFlags);
-#endif
-}
-
-#endif

src/posix/platform/include/openthread/openthread-system.h

@@ -187,6 +187,14 @@ unsigned int otSysGetThreadNetifIndex(void);
  */
 const char *otSysGetInfraNetifName(void);
 
+/**
+ * Returns the infrastructure network interface index.
+ *
+ * @returns The infrastructure network interface index.
+ *
+ */
+uint32_t otSysGetInfraNetifIndex(void);
+
 /**
  * Returns the radio spinel metrics.
  *

src/posix/platform/infra_if.cpp

@@ -91,6 +91,7 @@ exit:
     return ret;
 }
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 otError otPlatInfraIfSendIcmp6Nd(uint32_t            aInfraIfIndex,
                                  const otIp6Address *aDestAddress,
                                  const uint8_t      *aBuffer,
@@ -98,6 +99,7 @@ otError otPlatInfraIfSendIcmp6Nd(uint32_t            aInfraIfIndex,
 {
     return ot::Posix::InfraNetif::Get().SendIcmp6Nd(aInfraIfIndex, *aDestAddress, aBuffer, aBufferLength);
 }
+#endif
 
 otError otPlatInfraIfDiscoverNat64Prefix(uint32_t aInfraIfIndex)
 {
@@ -114,6 +116,8 @@ bool platformInfraIfIsRunning(void) { return ot::Posix::InfraNetif::Get().IsRunn
 
 const char *otSysGetInfraNetifName(void) { return ot::Posix::InfraNetif::Get().GetNetifName(); }
 
+uint32_t otSysGetInfraNetifIndex(void) { return ot::Posix::InfraNetif::Get().GetNetifIndex(); }
+
 uint32_t otSysGetInfraNetifFlags(void) { return ot::Posix::InfraNetif::Get().GetFlags(); }
 
 void otSysCountInfraNetifAddresses(otSysInfraNetIfAddressCounters *aAddressCounters)
@@ -206,6 +210,7 @@ int CreateNetLinkSocket(void)
     return sock;
 }
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 otError InfraNetif::SendIcmp6Nd(uint32_t            aInfraIfIndex,
                                 const otIp6Address &aDestAddress,
                                 const uint8_t      *aBuffer,
@@ -279,6 +284,7 @@ otError InfraNetif::SendIcmp6Nd(uint32_t            aInfraIfIndex,
 exit:
     return error;
 }
+#endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 
 bool InfraNetif::IsRunning(void) const
 {
@@ -352,6 +358,20 @@ exit:
     return;
 }
 
+#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
+void InfraNetif::HandleBackboneStateChange(otInstance *aInstance, otChangedFlags aFlags)
+{
+    OT_ASSERT(gInstance == aInstance);
+
+    OT_UNUSED_VARIABLE(aInstance);
+    OT_UNUSED_VARIABLE(aFlags);
+
+#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    mMulticastRoutingManager.HandleStateChange(aInstance, aFlags);
+#endif
+}
+#endif
+
 bool InfraNetif::HasLinkLocalAddress(void) const
 {
     bool            hasLla  = false;
@@ -389,18 +409,23 @@ void InfraNetif::Init(void) { mNetLinkSocket = CreateNetLinkSocket(); }
 
 void InfraNetif::SetInfraNetif(const char *aIfName, int aIcmp6Socket)
 {
-    uint32_t             ifIndex = 0;
-    otBorderRoutingState state   = otBorderRoutingGetState(gInstance);
+    uint32_t ifIndex = 0;
+
+    OT_UNUSED_VARIABLE(aIcmp6Socket);
 
     OT_ASSERT(gInstance != nullptr);
-
     VerifyOrDie(mNetLinkSocket != -1, OT_EXIT_INVALID_STATE);
-    VerifyOrDie(state == OT_BORDER_ROUTING_STATE_UNINITIALIZED || state == OT_BORDER_ROUTING_STATE_DISABLED,
-                OT_EXIT_INVALID_STATE);
+
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+    SetInfraNetifIcmp6SocketForBorderRouting(aIcmp6Socket);
+#endif
+#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    VerifyOrDie(!mMulticastRoutingManager.IsEnabled(), OT_EXIT_INVALID_STATE);
+#endif
 
     if (aIfName == nullptr || aIfName[0] == '\0')
     {
-        otLogWarnPlat("Border Routing feature is disabled: infra/backbone interface is missing");
+        otLogWarnPlat("Border Routing/Backbone Router feature is disabled: infra interface is missing");
         ExitNow();
     }
 
@@ -417,12 +442,6 @@ void InfraNetif::SetInfraNetif(const char *aIfName, int aIcmp6Socket)
 
     mInfraIfIndex = ifIndex;
 
-    if (mInfraIfIcmp6Socket != -1)
-    {
-        close(mInfraIfIcmp6Socket);
-    }
-    mInfraIfIcmp6Socket = aIcmp6Socket;
-
 exit:
     return;
 }
@@ -432,8 +451,15 @@ void InfraNetif::SetUp(void)
     OT_ASSERT(gInstance != nullptr);
     VerifyOrExit(mNetLinkSocket != -1);
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     SuccessOrDie(otBorderRoutingInit(gInstance, mInfraIfIndex, platformInfraIfIsRunning()));
     SuccessOrDie(otBorderRoutingSetEnabled(gInstance, /* aEnabled */ true));
+#endif
+
+#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    mMulticastRoutingManager.SetUp();
+#endif
+
     Mainloop::Manager::Get().Add(*this);
 exit:
     return;
@@ -441,17 +467,26 @@ exit:
 
 void InfraNetif::TearDown(void)
 {
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     IgnoreError(otBorderRoutingSetEnabled(gInstance, false));
+#endif
+
+#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    mMulticastRoutingManager.TearDown();
+#endif
+
     Mainloop::Manager::Get().Remove(*this);
 }
 
 void InfraNetif::Deinit(void)
 {
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     if (mInfraIfIcmp6Socket != -1)
     {
         close(mInfraIfIcmp6Socket);
         mInfraIfIcmp6Socket = -1;
     }
+#endif
 
     if (mNetLinkSocket != -1)
     {
@@ -459,16 +494,20 @@ void InfraNetif::Deinit(void)
         mNetLinkSocket = -1;
     }
 
-    mInfraIfIndex = 0;
+    mInfraIfName[0] = '\0';
+    mInfraIfIndex   = 0;
 }
 
 void InfraNetif::Update(otSysMainloopContext &aContext)
 {
-    VerifyOrExit(mInfraIfIcmp6Socket != -1);
     VerifyOrExit(mNetLinkSocket != -1);
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+    VerifyOrExit(mInfraIfIcmp6Socket != -1);
+
     FD_SET(mInfraIfIcmp6Socket, &aContext.mReadFdSet);
     aContext.mMaxFd = OT_MAX(aContext.mMaxFd, mInfraIfIcmp6Socket);
+#endif
 
     FD_SET(mNetLinkSocket, &aContext.mReadFdSet);
     aContext.mMaxFd = OT_MAX(aContext.mMaxFd, mNetLinkSocket);
@@ -506,7 +545,9 @@ void InfraNetif::ReceiveNetLinkMessage(void)
         case RTM_DELADDR:
         case RTM_NEWLINK:
         case RTM_DELLINK:
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
             SuccessOrDie(otPlatInfraIfStateChanged(gInstance, mInfraIfIndex, platformInfraIfIsRunning()));
+#endif
             break;
         case NLMSG_ERROR:
         {
@@ -525,6 +566,7 @@ exit:
     return;
 }
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 void InfraNetif::ReceiveIcmp6Message(void)
 {
     otError  error = OT_ERROR_NONE;
@@ -596,6 +638,7 @@ exit:
         otLogDebgPlat("Failed to handle ICMPv6 message: %s", otThreadErrorToString(error));
     }
 }
+#endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 
 #if OPENTHREAD_POSIX_CONFIG_NAT64_AIL_PREFIX_ENABLE
 const char         InfraNetif::kWellKnownIpv4OnlyName[]   = "ipv4only.arpa";
@@ -671,7 +714,9 @@ void InfraNetif::DiscoverNat64PrefixDone(union sigval sv)
         }
     }
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     otPlatInfraIfDiscoverNat64PrefixDone(gInstance, Get().mInfraIfIndex, &prefix);
+#endif
 
 exit:
     freeaddrinfo(res);
@@ -726,15 +771,35 @@ exit:
 }
 #endif // OPENTHREAD_POSIX_CONFIG_NAT64_AIL_PREFIX_ENABLE
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+void InfraNetif::SetInfraNetifIcmp6SocketForBorderRouting(int aIcmp6Socket)
+{
+    otBorderRoutingState state = otBorderRoutingGetState(gInstance);
+
+    VerifyOrDie(state == OT_BORDER_ROUTING_STATE_UNINITIALIZED || state == OT_BORDER_ROUTING_STATE_DISABLED,
+                OT_EXIT_INVALID_STATE);
+
+    if (mInfraIfIcmp6Socket != -1)
+    {
+        close(mInfraIfIcmp6Socket);
+    }
+    mInfraIfIcmp6Socket = aIcmp6Socket;
+}
+#endif
+
 void InfraNetif::Process(const otSysMainloopContext &aContext)
 {
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     VerifyOrExit(mInfraIfIcmp6Socket != -1);
+#endif
     VerifyOrExit(mNetLinkSocket != -1);
 
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     if (FD_ISSET(mInfraIfIcmp6Socket, &aContext.mReadFdSet))
     {
         ReceiveIcmp6Message();
     }
+#endif
 
     if (FD_ISSET(mNetLinkSocket, &aContext.mReadFdSet))
     {

src/posix/platform/infra_if.hpp

@@ -37,6 +37,7 @@
 #include <openthread/nat64.h>
 #include <openthread/openthread-system.h>
 
+#include "multicast_routing.hpp"
 #include "core/common/non_copyable.hpp"
 #include "posix/platform/mainloop.hpp"
 
@@ -82,7 +83,8 @@ public:
      * Sets the infrastructure network interface.
      *
      * @param[in]  aIfName       A pointer to infrastructure network interface name.
-     * @param[in]  aIcmp6Socket  A SOCK_RAW socket for sending/receiving ICMPv6 messages.
+     * @param[in]  aIcmp6Socket  A SOCK_RAW socket for sending/receiving ICMPv6 messages. If you don't need border
+     *                           routing feature, you can pass in -1.
      *
      */
     void SetInfraNetif(const char *aIfName, int aIcmp6Socket);
@@ -133,6 +135,15 @@ public:
      */
     void CountAddresses(otSysInfraNetIfAddressCounters &aAddressCounters) const;
 
+    /**
+     * Handles the backbone state change events.
+     *
+     * @param[in] aInstance  A pointer to the OpenThread instance.
+     * @param[in] aFlags     Flags that denote the state change events.
+     *
+     */
+    void HandleBackboneStateChange(otInstance *aInstance, otChangedFlags aFlags);
+
     /**
      * Sends an ICMPv6 Neighbor Discovery message on given infrastructure interface.
      *
@@ -176,6 +187,14 @@ public:
      */
     const char *GetNetifName(void) const { return (mInfraIfIndex != 0) ? mInfraIfName : nullptr; }
 
+    /**
+     * Gets the infrastructure network interface index.
+     *
+     * @returns The infrastructure network interface index.
+     *
+     */
+    uint32_t GetNetifIndex(void) const { return mInfraIfIndex; }
+
     /**
      * Gets the infrastructure network interface singleton.
      *
@@ -201,14 +220,22 @@ private:
     static const uint8_t      kValidNat64PrefixLength[];
 
     char     mInfraIfName[IFNAMSIZ];
-    uint32_t mInfraIfIndex       = 0;
-    int      mInfraIfIcmp6Socket = -1;
-    int      mNetLinkSocket      = -1;
+    uint32_t mInfraIfIndex  = 0;
+    int      mNetLinkSocket = -1;
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+    int mInfraIfIcmp6Socket = -1;
+#endif
+#if OPENTHREAD_POSIX_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    MulticastRoutingManager mMulticastRoutingManager;
+#endif
 
     void        ReceiveNetLinkMessage(void);
-    void        ReceiveIcmp6Message(void);
     bool        HasLinkLocalAddress(void) const;
     static void DiscoverNat64PrefixDone(union sigval sv);
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+    void SetInfraNetifIcmp6SocketForBorderRouting(int aIcmp6Socket);
+    void ReceiveIcmp6Message(void);
+#endif
 };
 
 } // namespace Posix

src/posix/platform/multicast_routing.cpp

@@ -159,7 +159,7 @@ void MulticastRoutingManager::UpdateMldReport(const Ip6::Address &aAddress, bool
     struct ipv6_mreq ipv6mr;
     otError          error = OT_ERROR_NONE;
 
-    ipv6mr.ipv6mr_interface = if_nametoindex(gBackboneNetifName);
+    ipv6mr.ipv6mr_interface = if_nametoindex(otSysGetInfraNetifName());
     memcpy(&ipv6mr.ipv6mr_multiaddr, aAddress.GetBytes(), sizeof(ipv6mr.ipv6mr_multiaddr));
     error = (setsockopt(mMulticastRouterSock, IPPROTO_IPV6, (isAdd ? IPV6_JOIN_GROUP : IPV6_LEAVE_GROUP),
                         (void *)&ipv6mr, sizeof(ipv6mr))
@@ -243,7 +243,7 @@ void MulticastRoutingManager::InitMulticastRouterSock(void)
 
     // Add Backbone network interface to MIF
     mif6ctl.mif6c_mifi = kMifIndexBackbone;
-    mif6ctl.mif6c_pifi = if_nametoindex(gBackboneNetifName);
+    mif6ctl.mif6c_pifi = otSysGetInfraNetifIndex();
     VerifyOrDie(mif6ctl.mif6c_pifi > 0, OT_EXIT_ERROR_ERRNO);
     VerifyOrDie(0 == setsockopt(mMulticastRouterSock, IPPROTO_IPV6, MRT6_ADD_MIF, &mif6ctl, sizeof(mif6ctl)),
                 OT_EXIT_ERROR_ERRNO);

src/posix/platform/multicast_routing.hpp

@@ -58,6 +58,7 @@ public:
     {
     }
 
+    bool IsEnabled(void) const { return mMulticastRouterSock >= 0; }
     void SetUp(void);
     void TearDown(void);
     void Update(otSysMainloopContext &aContext) override;
@@ -110,7 +111,6 @@ private:
     void    Remove(const Ip6::Address &aAddress);
     void    UpdateMldReport(const Ip6::Address &aAddress, bool isAdd);
     bool    HasMulticastListener(const Ip6::Address &aAddress) const;
-    bool    IsEnabled(void) const { return mMulticastRouterSock >= 0; }
     void    InitMulticastRouterSock(void);
     void    FinalizeMulticastRouterSock(void);
     void    ProcessMulticastRouterMessages(void);

src/posix/platform/openthread-posix-config.h

@@ -394,7 +394,8 @@
  * not explicit defined.
  */
 #ifndef OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
-#define OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+#define OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE \
+    (OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE || OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE)
 #endif
 
 /**

src/posix/platform/platform-posix.h

@@ -409,69 +409,12 @@ extern char gNetifName[IFNAMSIZ];
  */
 extern unsigned int gNetifIndex;
 
-/**
- * Initializes platform Backbone network.
- *
- * @note This function is called before OpenThread instance is created.
- *
- * @param[in]   aInterfaceName  A pointer to Thread network interface name.
- *
- */
-void platformBackboneInit(const char *aInterfaceName);
-
-/**
- * Sets up platform Backbone network.
- *
- * @note This function is called after OpenThread instance is created.
- *
- * @param[in]   aInstance       A pointer to the OpenThread instance.
- *
- */
-void platformBackboneSetUp(void);
-
-/**
- * Tears down platform Backbone network.
- *
- * @note This function is called before OpenThread instance is destructed.
- *
- */
-void platformBackboneTearDown(void);
-
-/**
- * Shuts down the platform Backbone network.
- *
- * @note This function is called after OpenThread instance is destructed.
- *
- */
-void platformBackboneDeinit(void);
-
-/**
- * Performs notifies state changes to platform Backbone network.
- *
- * @param[in]   aInstance       A pointer to the OpenThread instance.
- * @param[in]   aFlags          Flags that denote the state change events.
- *
- */
-void platformBackboneStateChange(otInstance *aInstance, otChangedFlags aFlags);
-
 /**
  * A pointer to the OpenThread instance.
  *
  */
 extern otInstance *gInstance;
 
-/**
- * The name of Backbone network interface.
- *
- */
-extern char gBackboneNetifName[IFNAMSIZ];
-
-/**
- * The index of Backbone network interface.
- *
- */
-extern unsigned int gBackboneNetifIndex;
-
 /**
  * Tells if the infrastructure interface is running.
  *

src/posix/platform/system.cpp

@@ -72,10 +72,7 @@ static void processStateChange(otChangedFlags aFlags, void *aContext)
 #endif
 
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-    if (gBackboneNetifIndex != 0)
-    {
-        platformBackboneStateChange(instance, aFlags);
-    }
+    ot::Posix::InfraNetif::Get().HandleBackboneStateChange(instance, aFlags);
 #endif
 }
 #endif
@@ -145,10 +142,6 @@ void platformInit(otPlatformConfig *aPlatformConfig)
 #endif
     platformRandomInit();
 
-#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-    platformBackboneInit(aPlatformConfig->mBackboneInterfaceName);
-#endif
-
 #if OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
     ot::Posix::InfraNetif::Get().Init();
 
@@ -178,16 +171,20 @@ void platformSetUp(otPlatformConfig *aPlatformConfig)
 
     VerifyOrExit(!gDryRun);
 
-#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-    platformBackboneSetUp();
-#endif
-
 #if OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
     if (aPlatformConfig->mBackboneInterfaceName != nullptr && strlen(aPlatformConfig->mBackboneInterfaceName) > 0)
     {
-        otSysSetInfraNetif(aPlatformConfig->mBackboneInterfaceName,
-                           ot::Posix::InfraNetif::CreateIcmp6Socket(aPlatformConfig->mBackboneInterfaceName));
+        int icmp6Sock = -1;
+
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+        icmp6Sock = ot::Posix::InfraNetif::CreateIcmp6Socket(aPlatformConfig->mBackboneInterfaceName);
+#endif
+
+        otSysSetInfraNetif(aPlatformConfig->mBackboneInterfaceName, icmp6Sock);
     }
+#endif
+
+#if OPENTHREAD_POSIX_CONFIG_INFRA_IF_ENABLE
     ot::Posix::InfraNetif::Get().SetUp();
 #endif
 
@@ -246,10 +243,6 @@ void platformTearDown(void)
     ot::Posix::InfraNetif::Get().TearDown();
 #endif
 
-#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-    platformBackboneTearDown();
-#endif
-
 exit:
     return;
 }
@@ -278,10 +271,6 @@ void platformDeinit(void)
     ot::Posix::InfraNetif::Get().Deinit();
 #endif
 
-#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-    platformBackboneDeinit();
-#endif
-
 exit:
     return;
 }

src/posix/platform/udp.cpp

@@ -324,11 +324,12 @@ otError otPlatUdpBindToNetif(otUdpSocket *aUdpSocket, otNetifIdentifier aNetifId
     {
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
 #if __linux__
-        VerifyOrExit(setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, gBackboneNetifName, strlen(gBackboneNetifName)) == 0,
+        VerifyOrExit(setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, otSysGetInfraNetifName(),
+                                strlen(otSysGetInfraNetifName())) == 0,
                      error = OT_ERROR_FAILED);
 #else  // __NetBSD__ || __FreeBSD__ || __APPLE__
-        VerifyOrExit(setsockopt(fd, IPPROTO_IPV6, IPV6_BOUND_IF, &gBackboneNetifIndex, sizeof(gBackboneNetifIndex)) ==
-                         0,
+        uint32_t backboneNetifIndex = otSysGetInfraNetifIndex();
+        VerifyOrExit(setsockopt(fd, IPPROTO_IPV6, IPV6_BOUND_IF, &backboneNetifIndex, sizeof(backboneNetifIndex)) == 0,
                      error = OT_ERROR_FAILED);
 #endif // __linux__
 #else
@@ -473,7 +474,7 @@ otError otPlatUdpJoinMulticastGroup(otUdpSocket        *aUdpSocket,
         break;
     case OT_NETIF_BACKBONE:
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-        mreq.ipv6mr_interface = gBackboneNetifIndex;
+        mreq.ipv6mr_interface = otSysGetInfraNetifIndex();
 #else
         ExitNow(error = OT_ERROR_NOT_IMPLEMENTED);
 #endif
@@ -513,7 +514,7 @@ otError otPlatUdpLeaveMulticastGroup(otUdpSocket        *aUdpSocket,
         break;
     case OT_NETIF_BACKBONE:
 #if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
-        mreq.ipv6mr_interface = gBackboneNetifIndex;
+        mreq.ipv6mr_interface = otSysGetInfraNetifIndex();
 #else
         ExitNow(error = OT_ERROR_NOT_IMPLEMENTED);
 #endif