[posix] enable building infra_if.cpp on macOS (#9891)

This change makes it possible to build the `posix/platform/infra_if`
module on macOS (and other non-Linux systems). It adds guard checks
`#ifdef __linux__` around the use of `mNetLinkSocket`(used for
network interface state change detection). This allows compilation to
proceed on macOS, though equivalent functionality for detecting netif
change is not yet implemented.

This commit also adds a new `toranj-macos` workflow job to validate
that the code builds successfully with the `posix` platform.

.github/workflows/toranj.yml

@@ -159,6 +159,28 @@ jobs:
         git clean -dfx
         ./tests/toranj/build.sh --enable-plat-key-ref all
 
+  toranj-macos:
+    name: toranj-macos
+    runs-on: macos-14
+    steps:
+    - name: Harden Runner
+      uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+      with:
+        egress-policy: audit # TODO: change to 'egress-policy: block' after couple of runs
+
+    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      with:
+        submodules: true
+    - name: Bootstrap
+      env:
+        GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+      run: |
+        brew update
+        brew install ninja
+    - name: Build & Run
+      run: |
+        ./tests/toranj/build.sh posix-15.4
+
   upload-coverage:
     needs:
     - toranj-cli

src/posix/platform/infra_if.cpp

@@ -190,6 +190,7 @@ bool IsAddressUniqueLocal(const in6_addr &aAddress) { return (aAddress.s6_addr[0
 
 bool IsAddressGlobalUnicast(const in6_addr &aAddress) { return (aAddress.s6_addr[0] & 0xe0) == 0x20; }
 
+#ifdef __linux__
 // Create a net-link socket that subscribes to link & addresses events.
 int CreateNetLinkSocket(void)
 {
@@ -209,6 +210,7 @@ int CreateNetLinkSocket(void)
 
     return sock;
 }
+#endif // #ifdef __linux__
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 otError InfraNetif::SendIcmp6Nd(uint32_t            aInfraIfIndex,
@@ -405,7 +407,12 @@ bool InfraNetif::HasLinkLocalAddress(void) const
     return hasLla;
 }
 
-void InfraNetif::Init(void) { mNetLinkSocket = CreateNetLinkSocket(); }
+void InfraNetif::Init(void)
+{
+#ifdef __linux__
+    mNetLinkSocket = CreateNetLinkSocket();
+#endif
+}
 
 void InfraNetif::SetInfraNetif(const char *aIfName, int aIcmp6Socket)
 {
@@ -414,7 +421,9 @@ void InfraNetif::SetInfraNetif(const char *aIfName, int aIcmp6Socket)
     OT_UNUSED_VARIABLE(aIcmp6Socket);
 
     OT_ASSERT(gInstance != nullptr);
+#ifdef __linux__
     VerifyOrDie(mNetLinkSocket != -1, OT_EXIT_INVALID_STATE);
+#endif
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     SetInfraNetifIcmp6SocketForBorderRouting(aIcmp6Socket);
@@ -449,7 +458,9 @@ exit:
 void InfraNetif::SetUp(void)
 {
     OT_ASSERT(gInstance != nullptr);
+#ifdef __linux__
     VerifyOrExit(mNetLinkSocket != -1);
+#endif
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     SuccessOrDie(otBorderRoutingInit(gInstance, mInfraIfIndex, otSysInfraIfIsRunning()));
@@ -461,6 +472,9 @@ void InfraNetif::SetUp(void)
 #endif
 
     Mainloop::Manager::Get().Add(*this);
+
+    ExitNow(); // To silence unused `exit` label warning.
+
 exit:
     return;
 }
@@ -488,11 +502,13 @@ void InfraNetif::Deinit(void)
     }
 #endif
 
+#ifdef __linux__
     if (mNetLinkSocket != -1)
     {
         close(mNetLinkSocket);
         mNetLinkSocket = -1;
     }
+#endif
 
     mInfraIfName[0] = '\0';
     mInfraIfIndex   = 0;
@@ -500,7 +516,9 @@ void InfraNetif::Deinit(void)
 
 void InfraNetif::Update(otSysMainloopContext &aContext)
 {
+#ifdef __linux__
     VerifyOrExit(mNetLinkSocket != -1);
+#endif
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     VerifyOrExit(mInfraIfIcmp6Socket != -1);
@@ -509,13 +527,17 @@ void InfraNetif::Update(otSysMainloopContext &aContext)
     aContext.mMaxFd = OT_MAX(aContext.mMaxFd, mInfraIfIcmp6Socket);
 #endif
 
+#ifdef __linux__
     FD_SET(mNetLinkSocket, &aContext.mReadFdSet);
     aContext.mMaxFd = OT_MAX(aContext.mMaxFd, mNetLinkSocket);
+#endif
 
 exit:
     return;
 }
 
+#ifdef __linux__
+
 void InfraNetif::ReceiveNetLinkMessage(void)
 {
     const size_t kMaxNetLinkBufSize = 8192;
@@ -566,6 +588,8 @@ exit:
     return;
 }
 
+#endif // #ifdef __linux__
+
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 void InfraNetif::ReceiveIcmp6Message(void)
 {
@@ -792,7 +816,10 @@ void InfraNetif::Process(const otSysMainloopContext &aContext)
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     VerifyOrExit(mInfraIfIcmp6Socket != -1);
 #endif
+
+#ifdef __linux__
     VerifyOrExit(mNetLinkSocket != -1);
+#endif
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     if (FD_ISSET(mInfraIfIcmp6Socket, &aContext.mReadFdSet))
@@ -801,10 +828,12 @@ void InfraNetif::Process(const otSysMainloopContext &aContext)
     }
 #endif
 
+#ifdef __linux__
     if (FD_ISSET(mNetLinkSocket, &aContext.mReadFdSet))
     {
         ReceiveNetLinkMessage();
     }
+#endif
 
 exit:
     return;

src/posix/platform/infra_if.hpp

@@ -220,8 +220,12 @@ private:
     static const uint8_t      kValidNat64PrefixLength[];
 
     char     mInfraIfName[IFNAMSIZ];
-    uint32_t mInfraIfIndex  = 0;
-    int      mNetLinkSocket = -1;
+    uint32_t mInfraIfIndex = 0;
+
+#ifdef __linux__
+    int mNetLinkSocket = -1;
+#endif
+
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     int mInfraIfIcmp6Socket = -1;
 #endif
@@ -229,7 +233,10 @@ private:
     MulticastRoutingManager mMulticastRoutingManager;
 #endif
 
-    void        ReceiveNetLinkMessage(void);
+#ifdef __linux__
+    void ReceiveNetLinkMessage(void);
+#endif
+
     bool        HasLinkLocalAddress(void) const;
     static void DiscoverNat64PrefixDone(union sigval sv);
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE

tests/toranj/openthread-core-toranj-config-posix.h

@@ -39,6 +39,10 @@
 
 #define OPENTHREAD_CONFIG_PLATFORM_INFO "POSIX-toranj"
 
+#ifdef __linux__
+#define OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE 1
+#endif
+
 #define OPENTHREAD_CONFIG_LOG_OUTPUT OPENTHREAD_CONFIG_LOG_OUTPUT_PLATFORM_DEFINED
 
 #define OPENTHREAD_CONFIG_BORDER_ROUTER_ENABLE 1

tests/toranj/openthread-core-toranj-config-simulation.h

@@ -69,6 +69,8 @@
 
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_USE_HEAP_ENABLE 1
 
+#define OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE 1
+
 #define OPENTHREAD_CONFIG_RADIO_STATS_ENABLE 0
 
 #endif /* OPENTHREAD_CORE_TORANJ_CONFIG_SIMULATION_H_ */

tests/toranj/openthread-core-toranj-config.h

@@ -170,8 +170,6 @@
 
 #define OPENTHREAD_CONFIG_DELAY_AWARE_QUEUE_MANAGEMENT_ENABLE 1
 
-#define OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE 1
-
 #define OPENTHREAD_CONFIG_CLI_REGISTER_IP6_RECV_CALLBACK 1
 
 #define OPENTHREAD_CONFIG_MLE_PARENT_RESPONSE_CALLBACK_API_ENABLE 1