[border-router] add platform API otPlatInfraIfHasAddress (#6430)

This commit removes the need of getting LLA of infra interface but
adds a new platform API otPlatInfraIfHasAddress which matches the
infra interface and a given address.

Background:
The infra interface LLA is used in the Routing Manager for only
testing if RA/RS message is initiated from the infra interface.

include/openthread/border_router.h

@@ -57,25 +57,20 @@ extern "C" {
  *
  * @note  This method MUST be called before any other otBorderRouting* APIs.
  *
- * @param[in]  aInstance                 A pointer to an OpenThread instance.
- * @param[in]  aInfraIfIndex             The infrastructure interface index.
- * @param[in]  aInfraIfIsRunning         A boolean that indicates whether the infrastructure
- *                                       interface is running.
- * @param[in]  aInfraIfLinkLocalAddress  A pointer to the IPv6 link-local address of the infrastructure
- *                                       interface. NULL if the IPv6 link-local address is missing.
+ * @param[in]  aInstance          A pointer to an OpenThread instance.
+ * @param[in]  aInfraIfIndex      The infrastructure interface index.
+ * @param[in]  aInfraIfIsRunning  A boolean that indicates whether the infrastructure
+ *                                interface is running.
  *
  * @retval  OT_ERROR_NONE           Successfully started the Border Routing Manager on given infrastructure.
  * @retval  OT_ERROR_INVALID_STATE  The Border Routing Manager has already been initialized.
- * @retval  OT_ERROR_INVALID_ARGS   The index or the IPv6 link-local address of the infra interface is not valid.
+ * @retval  OT_ERROR_INVALID_ARGS   The index of the infrastructure interface is not valid.
  * @retval  OT_ERROR_FAILED         Internal failure. Usually due to failure in generating random prefixes.
  *
  * @sa otPlatInfraIfStateChanged.
  *
  */
-otError otBorderRoutingInit(otInstance *        aInstance,
-                            uint32_t            aInfraIfIndex,
-                            bool                aInfraIfIsRunning,
-                            const otIp6Address *aInfraIfLinkLocalAddress);
+otError otBorderRoutingInit(otInstance *aInstance, uint32_t aInfraIfIndex, bool aInfraIfIsRunning);
 
 /**
  * This method enables/disables the Border Routing Manager.

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (101)
+#define OPENTHREAD_API_VERSION (102)
 
 /**
  * @addtogroup api-instance

include/openthread/platform/infra_if.h

@@ -46,6 +46,17 @@
 extern "C" {
 #endif
 
+/**
+ * This method tells whether an infra interface has the given IPv6 address assigned.
+ *
+ * @param[in]  aInfraIfIndex  The index of the infra interface.
+ * @param[in]  aAddress       The IPv6 address.
+ *
+ * @returns  TRUE if the infra interface has given IPv6 address assigned, FALSE otherwise.
+ *
+ */
+bool otPlatInfraIfHasAddress(uint32_t aInfraIfIndex, const otIp6Address *aAddress);
+
 /**
  * This method sends an ICMPv6 Neighbor Discovery message on given infrastructure interface.
  *
@@ -94,24 +105,22 @@ extern void otPlatInfraIfRecvIcmp6Nd(otInstance *        aInstance,
  * The infra interface driver calls this method to notify OpenThread
  * of the interface state changes.
  *
+ * It is fine for the platform to call to method even when the running state
+ * of the interface hasn't changed. In this case, the Routing Manager state is
+ * not affected.
+ *
  * @param[in]  aInstance          The OpenThread instance structure.
  * @param[in]  aInfraIfIndex      The index of the infrastructure interface.
  * @param[in]  aIsRunning         A boolean that indicates whether the infrastructure
  *                                interface is running.
- * @param[in]  aLinkLocalAddress  A pointer to the IPv6 link-local address of the infrastructure
- *                                interface. NULL if the IPv6 link-local address is lost.
  *
  * @retval  OT_ERROR_NONE           Successfully updated the infra interface status.
  * @retval  OT_ERROR_INVALID_STATE  The Routing Manager is not initialized.
  * @retval  OT_ERROR_INVALID_ARGS   The @p aInfraIfIndex doesn't match the infra interface the
- *                                  Routing Manager are initialized with, or the @p aLinkLocalAddress
- *                                  is not a valid IPv6 link-local address.
+ *                                  Routing Manager are initialized with.
  *
  */
-extern otError otPlatInfraIfStateChanged(otInstance *        aInstance,
-                                         uint32_t            aInfraIfIndex,
-                                         bool                aIsRunning,
-                                         const otIp6Address *aLinkLocalAddress);
+extern otError otPlatInfraIfStateChanged(otInstance *aInstance, uint32_t aInfraIfIndex, bool aIsRunning);
 
 #ifdef __cplusplus
 } // extern "C"

src/core/api/border_router_api.cpp

@@ -44,15 +44,11 @@
 using namespace ot;
 
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
-otError otBorderRoutingInit(otInstance *        aInstance,
-                            uint32_t            aInfraIfIndex,
-                            bool                aInfraIfIsRunning,
-                            const otIp6Address *aInfraIfLinkLocalAddress)
+otError otBorderRoutingInit(otInstance *aInstance, uint32_t aInfraIfIndex, bool aInfraIfIsRunning)
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    return instance.Get<BorderRouter::RoutingManager>().Init(
-        aInfraIfIndex, aInfraIfIsRunning, static_cast<const Ip6::Address *>(aInfraIfLinkLocalAddress));
+    return instance.Get<BorderRouter::RoutingManager>().Init(aInfraIfIndex, aInfraIfIsRunning);
 }
 
 otError otBorderRoutingSetEnabled(otInstance *aInstance, bool aEnabled)

src/core/border_router/infra_if_platform.cpp

@@ -53,15 +53,11 @@ extern "C" void otPlatInfraIfRecvIcmp6Nd(otInstance *        aInstance,
         aInfraIfIndex, static_cast<const Ip6::Address &>(*aSrcAddress), aBuffer, aBufferLength);
 }
 
-extern "C" otError otPlatInfraIfStateChanged(otInstance *        aInstance,
-                                             uint32_t            aInfraIfIndex,
-                                             bool                aIsRunning,
-                                             const otIp6Address *aLinkLocalAddress)
+extern "C" otError otPlatInfraIfStateChanged(otInstance *aInstance, uint32_t aInfraIfIndex, bool aIsRunning)
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    return instance.Get<BorderRouter::RoutingManager>().HandleInfraIfStateChanged(
-        aInfraIfIndex, aIsRunning, static_cast<const Ip6::Address *>(aLinkLocalAddress));
+    return instance.Get<BorderRouter::RoutingManager>().HandleInfraIfStateChanged(aInfraIfIndex, aIsRunning);
 }
 
 #endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE

src/core/border_router/routing_manager.cpp

@@ -72,8 +72,6 @@ RoutingManager::RoutingManager(Instance &aInstance)
     , mRouterSolicitCount(0)
     , mRoutingPolicyTimer(aInstance, HandleRoutingPolicyTimer)
 {
-    mInfraIfLinkLocalAddress.Clear();
-
     mLocalOmrPrefix.Clear();
     memset(mAdvertisedOmrPrefixes, 0, sizeof(mAdvertisedOmrPrefixes));
 
@@ -82,7 +80,7 @@ RoutingManager::RoutingManager(Instance &aInstance)
     memset(mDiscoveredPrefixes, 0, sizeof(mDiscoveredPrefixes));
 }
 
-Error RoutingManager::Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const Ip6::Address *aInfraIfLinkLocalAddress)
+Error RoutingManager::Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning)
 {
     Error error;
 
@@ -95,7 +93,7 @@ Error RoutingManager::Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const
     mInfraIfIndex = aInfraIfIndex;
 
     // Initialize the infra interface status.
-    SuccessOrExit(error = HandleInfraIfStateChanged(mInfraIfIndex, aInfraIfIsRunning, aInfraIfLinkLocalAddress));
+    SuccessOrExit(error = HandleInfraIfStateChanged(mInfraIfIndex, aInfraIfIsRunning));
 
 exit:
     if (error != kErrorNone)
@@ -175,7 +173,7 @@ exit:
 
 void RoutingManager::EvaluateState(void)
 {
-    if (mIsEnabled && Get<Mle::MleRouter>().IsAttached() && mInfraIfIsRunning && mInfraIfLinkLocalAddress.IsLinkLocal())
+    if (mIsEnabled && Get<Mle::MleRouter>().IsAttached() && mInfraIfIsRunning)
     {
         Start();
     }
@@ -242,13 +240,9 @@ void RoutingManager::RecvIcmp6Message(uint32_t            aInfraIfIndex,
 {
     Error                    error = kErrorNone;
     const Ip6::Icmp::Header *icmp6Header;
-    const Ip6::Address *     infraLinkLocalAddr;
 
     VerifyOrExit(IsInitialized() && mIsRunning, error = kErrorDrop);
-
     VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = kErrorDrop);
-    infraLinkLocalAddr = static_cast<const Ip6::Address *>(&mInfraIfLinkLocalAddress);
-
     VerifyOrExit(aBuffer != nullptr && aBufferLength >= sizeof(*icmp6Header), error = kErrorParse);
 
     icmp6Header = reinterpret_cast<const Ip6::Icmp::Header *>(aBuffer);
@@ -260,7 +254,7 @@ void RoutingManager::RecvIcmp6Message(uint32_t            aInfraIfIndex,
         break;
     case Ip6::Icmp::Header::kTypeRouterSolicit:
         // Drop Router Solicitations initiated from infra interface.
-        VerifyOrExit(aSrcAddress != *infraLinkLocalAddr, error = kErrorDrop);
+        VerifyOrExit(!otPlatInfraIfHasAddress(mInfraIfIndex, &aSrcAddress), error = kErrorDrop);
         HandleRouterSolicit(aSrcAddress, aBuffer, aBufferLength);
         break;
     default:
@@ -274,29 +268,18 @@ exit:
     }
 }
 
-Error RoutingManager::HandleInfraIfStateChanged(uint32_t            aInfraIfIndex,
-                                                bool                aIsRunning,
-                                                const Ip6::Address *aLinkLocalAddress)
+Error RoutingManager::HandleInfraIfStateChanged(uint32_t aInfraIfIndex, bool aIsRunning)
 {
     Error error = kErrorNone;
 
     VerifyOrExit(IsInitialized(), error = kErrorInvalidState);
     VerifyOrExit(aInfraIfIndex == mInfraIfIndex, error = kErrorInvalidArgs);
-    VerifyOrExit(aLinkLocalAddress == nullptr || aLinkLocalAddress->IsLinkLocal(), error = kErrorInvalidArgs);
+    VerifyOrExit(aIsRunning != mInfraIfIsRunning);
 
-    otLogInfoBr("infra interface state changed: %s, link-local-addr=%s", aIsRunning ? "RUNNING" : "NOT RUNNING",
-                (aLinkLocalAddress != nullptr) ? aLinkLocalAddress->ToString().AsCString() : "(null)");
+    otLogInfoBr("infra interface (%u) state changed: %sRUNNING -> %sRUNNING", aInfraIfIndex,
+                (mInfraIfIsRunning ? "" : "NOT "), (aIsRunning ? "" : "NOT "));
 
     mInfraIfIsRunning = aIsRunning;
-    if (aLinkLocalAddress == nullptr)
-    {
-        mInfraIfLinkLocalAddress.Clear();
-    }
-    else
-    {
-        mInfraIfLinkLocalAddress = *aLinkLocalAddress;
-    }
-
     EvaluateState();
 
 exit:

src/core/border_router/routing_manager.hpp

@@ -85,17 +85,15 @@ public:
     /**
      * This method initializes the routing manager on given infrastructure interface.
      *
-     * @param[in]  aInfraIfIndex  An infrastructure network interface index.
-     * @param[in]  aInfraIfIsRunning         A boolean that indicates whether the infrastructure
-     *                                       interface is running.
-     * @param[in]  aInfraIfLinkLocalAddress  A pointer to the IPv6 link-local address of the infrastructure
-     *                                       interface. NULL if the IPv6 link-local address is missing.
+     * @param[in]  aInfraIfIndex      An infrastructure network interface index.
+     * @param[in]  aInfraIfIsRunning  A boolean that indicates whether the infrastructure
+     *                                interface is running.
      *
-     * @retval  kErrorNone          Successfully started the routing manager.
-     * @retval  kErrorInvalidArgs   The index of the infra interface is not valid.
+     * @retval  kErrorNone         Successfully started the routing manager.
+     * @retval  kErrorInvalidArgs  The index of the infra interface is not valid.
      *
      */
-    Error Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning, const Ip6::Address *aInfraIfLinkLocalAddress);
+    Error Init(uint32_t aInfraIfIndex, bool aInfraIfIsRunning);
 
     /**
      * This method enables/disables the Border Routing Manager.
@@ -129,20 +127,17 @@ public:
     /**
      * This method handles infrastructure interface state changes.
      *
-     * @param[in]  aInfraIfIndex      The index of the infrastructure interface.
-     * @param[in]  aIsRunning         A boolean that indicates whether the infrastructure
-     *                                interface is running.
-     * @param[in]  aLinkLocalAddress  A pointer to the IPv6 link local address of the infrastructure
-     *                                interface. NULL if the IPv6 link local address is lost.
+     * @param[in]  aInfraIfIndex  The index of the infrastructure interface.
+     * @param[in]  aIsRunning     A boolean that indicates whether the infrastructure
+     *                            interface is running.
      *
      * @retval  kErrorNone          Successfully updated the infra interface status.
      * @retval  kErrorInvalidState  The Routing Manager is not initialized.
-     * @retval  kErrorInvalidArgs   The @p aInfraIfIndex doesn't match the infra interface the Routing Manager are
-     *                              initialized with, or the @p aLinkLocalAddress is not a valid IPv6 link-local
-     *                              address.
+     * @retval  kErrorInvalidArgs   The @p aInfraIfIndex doesn't match the infra interface
+     *                              the Routing Manager is initialized with.
      *
      */
-    Error HandleInfraIfStateChanged(uint32_t aInfraIfIndex, bool aIsRunning, const Ip6::Address *aLinkLocalAddress);
+    Error HandleInfraIfStateChanged(uint32_t aInfraIfIndex, bool aIsRunning);
 
 private:
     enum : uint16_t
@@ -260,12 +255,6 @@ private:
     // messages will be sent.
     uint32_t mInfraIfIndex;
 
-    // The IPv6 link-local address of the infra interface. It's
-    // UNSPECIFIED if no valid IPv6 link-local address is associated
-    // with the infra interface and the Routing Manager will be
-    // stopped.
-    Ip6::Address mInfraIfLinkLocalAddress;
-
     // The OMR prefix loaded from local persistent storage or randomly
     // generated if non is found in persistent storage.
     Ip6::Prefix mLocalOmrPrefix;

src/posix/platform/infra_if.cpp

@@ -59,17 +59,44 @@
 #include "common/debug.hpp"
 #include "lib/platform/exit_code.h"
 
-static char         sInfraIfName[IFNAMSIZ];
-static uint32_t     sInfraIfIndex       = 0;
-static int          sInfraIfIcmp6Socket = -1;
-static int          sNetLinkSocket      = -1;
-static otIp6Address sInfraIfLinkLocalAddr;
+static char     sInfraIfName[IFNAMSIZ];
+static uint32_t sInfraIfIndex       = 0;
+static int      sInfraIfIcmp6Socket = -1;
+static int      sNetLinkSocket      = -1;
 
 static int  CreateIcmp6Socket(void);
 static int  CreateNetLinkSocket(void);
 static void ReceiveNetLinkMessage(otInstance *aInstance);
 static void ReceiveIcmp6Message(otInstance *aInstance);
 
+bool otPlatInfraIfHasAddress(uint32_t aInfraIfIndex, const otIp6Address *aAddress)
+{
+    bool            ret     = false;
+    struct ifaddrs *ifAddrs = nullptr;
+
+    VerifyOrDie(getifaddrs(&ifAddrs) != -1, OT_EXIT_ERROR_ERRNO);
+
+    for (struct ifaddrs *addr = ifAddrs; addr != nullptr; addr = addr->ifa_next)
+    {
+        struct sockaddr_in6 *ip6Addr;
+
+        if (if_nametoindex(addr->ifa_name) != aInfraIfIndex || addr->ifa_addr->sa_family != AF_INET6)
+        {
+            continue;
+        }
+
+        ip6Addr = reinterpret_cast<sockaddr_in6 *>(addr->ifa_addr);
+        if (memcmp(&ip6Addr->sin6_addr, aAddress, sizeof(*aAddress)) == 0)
+        {
+            ExitNow(ret = true);
+        }
+    }
+
+exit:
+    freeifaddrs(ifAddrs);
+    return ret;
+}
+
 otError otPlatInfraIfSendIcmp6Nd(uint32_t            aInfraIfIndex,
                                  const otIp6Address *aDestAddress,
                                  const uint8_t *     aBuffer,
@@ -144,37 +171,6 @@ exit:
     return error;
 }
 
-const otIp6Address *platformInfraIfGetLinkLocalAddress(void)
-{
-    const otIp6Address *ret     = nullptr;
-    struct ifaddrs *    ifAddrs = nullptr;
-
-    VerifyOrDie(getifaddrs(&ifAddrs) != -1, OT_EXIT_ERROR_ERRNO);
-
-    for (struct ifaddrs *addr = ifAddrs; addr != nullptr; addr = addr->ifa_next)
-    {
-        struct sockaddr_in6 *ip6Addr;
-
-        if (strncmp(addr->ifa_name, sInfraIfName, sizeof(sInfraIfName)) != 0 || addr->ifa_addr->sa_family != AF_INET6)
-        {
-            continue;
-        }
-
-        ip6Addr = reinterpret_cast<sockaddr_in6 *>(addr->ifa_addr);
-        if (IN6_IS_ADDR_LINKLOCAL(&ip6Addr->sin6_addr))
-        {
-            memcpy(&sInfraIfLinkLocalAddr, &ip6Addr->sin6_addr, sizeof(sInfraIfLinkLocalAddr));
-            ExitNow(ret = &sInfraIfLinkLocalAddr);
-        }
-    }
-
-    otLogWarnPlat("cannot find IPv6 link-local address for interface %s", sInfraIfName);
-
-exit:
-    freeifaddrs(ifAddrs);
-    return ret;
-}
-
 bool platformInfraIfIsRunning(void)
 {
     int          sock;
@@ -350,12 +346,14 @@ static void ReceiveNetLinkMessage(otInstance *aInstance)
     {
         switch (header->nlmsg_type)
         {
-        case RTM_NEWLINK:
-        case RTM_DELLINK:
+        // There are no effective netlink message types to get us notified
+        // of interface RUNNING state changes. But addresses events are
+        // usually associated with interface state changes.
         case RTM_NEWADDR:
         case RTM_DELADDR:
-            SuccessOrDie(otPlatInfraIfStateChanged(aInstance, sInfraIfIndex, platformInfraIfIsRunning(),
-                                                   platformInfraIfGetLinkLocalAddress()));
+        case RTM_NEWLINK:
+        case RTM_DELLINK:
+            SuccessOrDie(otPlatInfraIfStateChanged(aInstance, sInfraIfIndex, platformInfraIfIsRunning()));
             break;
         case NLMSG_ERROR:
         {

src/posix/platform/platform-posix.h

@@ -525,14 +525,6 @@ void platformInfraIfDeinit(void);
  */
 bool platformInfraIfIsRunning(void);
 
-/**
- * this function returns the IPv6 link-local address of the infrastructure interface.
- *
- * @returns  A pointer to the link-local address; NULL if no link-local address is present.
- *
- */
-const otIp6Address *platformInfraIfGetLinkLocalAddress(void);
-
 /**
  * This function updates the read fd set.
  *

src/posix/platform/system.cpp

@@ -111,8 +111,7 @@ otInstance *otSysInit(otPlatformConfig *aPlatformConfig)
 
         infraIfIndex = platformInfraIfInit(instance, aPlatformConfig->mBackboneInterfaceName);
 
-        SuccessOrDie(otBorderRoutingInit(instance, infraIfIndex, platformInfraIfIsRunning(),
-                                         platformInfraIfGetLinkLocalAddress()));
+        SuccessOrDie(otBorderRoutingInit(instance, infraIfIndex, platformInfraIfIsRunning()));
         SuccessOrDie(otBorderRoutingSetEnabled(instance, /* aEnabled */ true));
     }
 #endif