[routing-manager] track whether a discovered router is local device (#10284)

This commit adds `mIsLocalDevice` in the `Router` class to track
whether it represents the local device (e.g., another software entity
on this device). This information is used to skip sending NS probes
to this router. Tracking this information directly in the `Router`
class is safer than checking the address using `mInfra.HasAddress()`,
as the addresses may have changed since the last RA was received.
This commit exposes this information through the public APIs and CLI
command, and updates `test_routing_manager` unit test to validate the
new flag.

include/openthread/border_routing.h

@@ -101,6 +101,7 @@ typedef struct otBorderRoutingRouterEntry
     bool         mManagedAddressConfigFlag : 1; ///< The router's Managed Address Config flag (`M` flag).
     bool         mOtherConfigFlag : 1;          ///< The router's Other Config flag (`O` flag).
     bool         mStubRouterFlag : 1;           ///< The router's Stub Router flag.
+    bool         mIsLocalDevice : 1;            ///< This router is the local device (this BR).
 } otBorderRoutingRouterEntry;
 
 /**

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (414)
+#define OPENTHREAD_API_VERSION (415)
 
 /**
  * @addtogroup api-instance

src/cli/cli_br.cpp

@@ -557,16 +557,17 @@ void Br::OutputRouterInfo(const otBorderRoutingRouterEntry &aEntry, RouterOutput
     OutputFormat(" (M:%u O:%u Stub:%u)", aEntry.mManagedAddressConfigFlag, aEntry.mOtherConfigFlag,
                  aEntry.mStubRouterFlag);
 
-    switch (aMode)
+    if (aMode == kLongVersion)
     {
-    case kShortVersion:
-        OutputNewLine();
-        break;
+        OutputFormat(" ms-since-rx:%lu", ToUlong(aEntry.mMsecSinceLastUpdate));
 
-    case kLongVersion:
-        OutputLine(" ms-since-rx:%lu", ToUlong(aEntry.mMsecSinceLastUpdate));
-        break;
+        if (aEntry.mIsLocalDevice)
+        {
+            OutputFormat(" (this BR)");
+        }
     }
+
+    OutputNewLine();
 }
 
 template <> otError Br::Process<Cmd("raoptions")>(Arg aArgs[])

src/core/border_router/routing_manager.cpp

@@ -1013,6 +1013,8 @@ void RoutingManager::RxRaTracker::ProcessRouterAdvertMessage(const RouterAdvert:
         }
     }
 
+    router->mIsLocalDevice = (aRaOrigin == kThisBrOtherEntity);
+
     UpdateRouterOnRx(*router);
 
     RemoveRoutersWithNoEntriesOrFlags();
@@ -1614,14 +1616,11 @@ void RoutingManager::RxRaTracker::HandleRouterTimer(void)
             continue;
         }
 
-        // If the `router` emitting RA has an address belonging to
-        // infra interface, it indicates that the RAs are from
-        // same device. In this case we skip performing NS probes.
-        // This addresses situation where platform may not be
-        // be able to receive and pass the NA message response
-        // from device itself.
+        // Skip NS probes if the router is this device. This prevents
+        // issues where the platform might not be able to receive and
+        // process the NA messages from the local device itself.
 
-        if (Get<RoutingManager>().mInfraIf.HasAddress(router.mAddress))
+        if (router.mIsLocalDevice)
         {
             continue;
         }
@@ -1877,6 +1876,7 @@ void RoutingManager::RxRaTracker::Router::CopyInfoTo(RouterEntry &aEntry, TimeMi
     aEntry.mManagedAddressConfigFlag = mManagedAddressConfigFlag;
     aEntry.mOtherConfigFlag          = mOtherConfigFlag;
     aEntry.mStubRouterFlag           = mStubRouterFlag;
+    aEntry.mIsLocalDevice            = mIsLocalDevice;
 }
 
 //---------------------------------------------------------------------------------------------------------------------

src/core/border_router/routing_manager.hpp

@@ -831,6 +831,7 @@ private:
             bool             mManagedAddressConfigFlag : 1;
             bool             mOtherConfigFlag : 1;
             bool             mStubRouterFlag : 1;
+            bool             mIsLocalDevice : 1;
         };
 
         //-  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

tests/unit/test_routing_manager.cpp

@@ -1108,8 +1108,10 @@ struct InfraRouter
     InfraRouter(const Ip6::Address &aAddress,
                 bool                aManagedAddressConfigFlag,
                 bool                aOtherConfigFlag,
-                bool                aStubRouterFlag)
+                bool                aStubRouterFlag,
+                bool                aIsLocalDevice = false)
         : mAddress(aAddress)
+        , mIsLocalDevice(aIsLocalDevice)
     {
         mFlags.Clear();
         mFlags.mManagedAddressConfigFlag = aManagedAddressConfigFlag;
@@ -1119,6 +1121,7 @@ struct InfraRouter
 
     Ip6::Address mAddress;
     RaFlags      mFlags;
+    bool         mIsLocalDevice;
 };
 
 template <uint16_t kNumRouters> void VerifyDiscoveredRouters(const InfraRouter (&aRouters)[kNumRouters])
@@ -1140,8 +1143,9 @@ void VerifyDiscoveredRouters(const InfraRouter *aRouters, uint16_t aNumRouters)
     {
         bool didFind = false;
 
-        Log("   address:%s, M:%u, O:%u, StubRouter:%u", AsCoreType(&entry.mAddress).ToString().AsCString(),
-            entry.mManagedAddressConfigFlag, entry.mOtherConfigFlag, entry.mStubRouterFlag);
+        Log("   address:%s, M:%u, O:%u, StubRouter:%u%s", AsCoreType(&entry.mAddress).ToString().AsCString(),
+            entry.mManagedAddressConfigFlag, entry.mOtherConfigFlag, entry.mStubRouterFlag,
+            entry.mIsLocalDevice ? " (this BR)" : "");
 
         for (uint16_t index = 0; index < aNumRouters; index++)
         {
@@ -1150,6 +1154,7 @@ void VerifyDiscoveredRouters(const InfraRouter *aRouters, uint16_t aNumRouters)
                 VerifyOrQuit(entry.mManagedAddressConfigFlag == aRouters[index].mFlags.mManagedAddressConfigFlag);
                 VerifyOrQuit(entry.mOtherConfigFlag == aRouters[index].mFlags.mOtherConfigFlag);
                 VerifyOrQuit(entry.mStubRouterFlag == aRouters[index].mFlags.mStubRouterFlag);
+                VerifyOrQuit(entry.mIsLocalDevice == aRouters[index].mIsLocalDevice);
                 didFind = true;
             }
         }
@@ -3015,7 +3020,8 @@ void TestLearnRaHeader(void)
     SendRouterAdvert(sInfraIfAddress, DefaultRoute(1000, NetworkData::kRoutePreferenceLow));
 
     AdvanceTime(1);
-    VerifyDiscoveredRouters({InfraRouter(sInfraIfAddress, /* M */ false, /* O */ false, /* StubRouter */ false)});
+    VerifyDiscoveredRouters(
+        {InfraRouter(sInfraIfAddress, /* M */ false, /* O */ false, /* StubRouter */ false, /* IsLocalDevice */ true)});
 
     //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     // RoutingManager should learn the header from the