[backbone-router] add deinit API (#6817)

This fixes the infinite loop when OTBR is pseudo-reset by DBus API.

src/posix/platform/backbone.cpp

@@ -69,6 +69,17 @@ exit:
     return;
 }
 
+void platformBackboneDeinit(void)
+{
+#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_MULTICAST_ROUTING_ENABLE
+    sMulticastRoutingManager.Deinit();
+#endif
+
+    gBackboneNetifIndex = 0;
+
+    memset(gBackboneNetifName, 0, sizeof(gBackboneNetifName));
+}
+
 void platformBackboneStateChange(otInstance *aInstance, otChangedFlags aFlags)
 {
     OT_UNUSED_VARIABLE(aInstance);

src/posix/platform/multicast_routing.cpp

@@ -60,6 +60,12 @@ void MulticastRoutingManager::Init(otInstance *aInstance)
     Mainloop::Manager::Get().Add(*this);
 }
 
+void MulticastRoutingManager::Deinit(void)
+{
+    Mainloop::Manager::Get().Remove(*this);
+    otBackboneRouterSetMulticastListenerCallback(mInstance, nullptr, nullptr);
+}
+
 void MulticastRoutingManager::HandleBackboneMulticastListenerEvent(void *                                 aContext,
                                                                    otBackboneRouterMulticastListenerEvent aEvent,
                                                                    const otIp6Address *                   aAddress)

src/posix/platform/multicast_routing.hpp

@@ -48,17 +48,9 @@
 namespace ot {
 namespace Posix {
 
-/**
- * This class implements Multicast Routing management.
- *
- */
 class MulticastRoutingManager : public Mainloop::Source, private NonCopyable
 {
 public:
-    /**
-     * This constructor initializes a Multicast Routing manager instance.
-     *
-     */
     explicit MulticastRoutingManager()
 
         : mLastExpireTime(0)
@@ -66,37 +58,10 @@ public:
     {
     }
 
-    /**
-     * This method initializes the Multicast Routing manager.
-     *
-     * @param[in]  aInstance  A pointer to an OpenThread instance.
-     *
-     */
     void Init(otInstance *aInstance);
-
-    /**
-     * This method updates the fd_set and timeout for mainloop.
-     *
-     * @param[inout]    aContext    A reference to the mainloop context.
-     *
-     */
+    void Deinit(void);
     void Update(otSysMainloopContext &aContext) override;
-
-    /**
-     * This method performs Multicast Routing processing.
-     *
-     * @param[in]   aContext    A reference to the mainloop context.
-     *
-     */
     void Process(const otSysMainloopContext &aContext) override;
-
-    /**
-     * This method handles Thread state changes.
-     *
-     * @param[in] aInstance  A pointer to an OpenThread instance.
-     * @param[in] aFlags     Flags that denote the state change events.
-     *
-     */
     void HandleStateChange(otInstance *aInstance, otChangedFlags aFlags);
 
 private:

src/posix/platform/platform-posix.h

@@ -436,6 +436,12 @@ extern unsigned int gNetifIndex;
  */
 void platformBackboneInit(otInstance *aInstance, const char *aInterfaceName);
 
+/**
+ * This function shuts down the platform Backbone network.
+ *
+ */
+void platformBackboneDeinit(void);
+
 /**
  * This function performs notifies state changes to platform Backbone network.
  *

src/posix/platform/system.cpp

@@ -177,6 +177,10 @@ void otSysDeinit(void)
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     ot::Posix::InfraNetif::Get().Deinit();
 #endif
+
+#if OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
+    platformBackboneDeinit();
+#endif
 }
 
 #if OPENTHREAD_POSIX_VIRTUAL_TIME