[test] add unit test `test_routing_manager` (#7927)

This commit adds a unit test for `RoutingManager` which builds a
foundation for writing test cases covering different behaviors of
`RoutingManager`, e.g., validating emitted router advertisements,
sending custom RA messages from different routers on AIL, adding or
removing entries in Network Data while monitoring the behavior of
`RoutingManager`.

3 files changed, 870 insertions, 0 deletions

diff --git a/tests/unit/CMakeLists.txt b/tests/unit/CMakeLists.txt
index 6d7b62dea..ae1e210af 100644
--- a/tests/unit/CMakeLists.txt
+++ b/tests/unit/CMakeLists.txt
@@ -857,6 +857,27 @@ add_executable(ot-test-serial-number
     test_serial_number.cpp
 )
 
+add_executable(ot-test-routing-manager
+    test_routing_manager.cpp
+)
+
+target_include_directories(ot-test-routing-manager
+    PRIVATE
+        ${COMMON_INCLUDES}
+)
+
+target_compile_options(ot-test-routing-manager
+    PRIVATE
+        ${COMMON_COMPILE_OPTIONS}
+)
+
+target_link_libraries(ot-test-routing-manager
+    PRIVATE
+        ${COMMON_LIBS}
+)
+
+add_test(NAME ot-test-routing-manager COMMAND ot-test-routing-manager)
+
 target_include_directories(ot-test-serial-number
     PRIVATE
         ${COMMON_INCLUDES}
diff --git a/tests/unit/Makefile.am b/tests/unit/Makefile.am
index 2063dedd4..a99b2d861 100644
--- a/tests/unit/Makefile.am
+++ b/tests/unit/Makefile.am
@@ -148,6 +148,7 @@ check_PROGRAMS                                                     += \
     ot-test-priority-queue                                            \
     ot-test-pskc                                                      \
     ot-test-serial-number                                             \
+    ot-test-routing-manager                                           \
     ot-test-smart-ptrs                                                \
     ot-test-string                                                    \
     ot-test-timer                                                     \
@@ -347,6 +348,10 @@ ot_test_meshcop_LDADD               = $(COMMON_LDADD)
 ot_test_meshcop_LIBTOOLFLAGS        = $(COMMON_LIBTOOLFLAGS)
 ot_test_meshcop_SOURCES             = $(COMMON_SOURCES) test_meshcop.cpp
 
+ot_test_routing_manager_LDADD        = $(COMMON_LDADD)
+ot_test_routing_manager_LIBTOOLFLAGS = $(COMMON_LIBTOOLFLAGS)
+ot_test_routing_manager_SOURCES      = $(COMMON_SOURCES) test_routing_manager.cpp
+
 ot_test_serial_number_LDADD         = $(COMMON_LDADD)
 ot_test_serial_number_LIBTOOLFLAGS  = $(COMMON_LIBTOOLFLAGS)
 ot_test_serial_number_SOURCES       = $(COMMON_SOURCES) test_serial_number.cpp
diff --git a/tests/unit/test_routing_manager.cpp b/tests/unit/test_routing_manager.cpp
new file mode 100644
index 000000000..cf48e8119
--- /dev/null
+++ b/tests/unit/test_routing_manager.cpp
@@ -0,0 +1,844 @@
+/*
+ *  Copyright (c) 2022, 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.
+ */
+
+#include <openthread/config.h>
+
+#include "test_platform.h"
+#include "test_util.hpp"
+
+#include <openthread/thread.h>
+
+#include "border_router/routing_manager.hpp"
+#include "common/arg_macros.hpp"
+#include "common/instance.hpp"
+#include "net/icmp6.hpp"
+#include "net/nd6.hpp"
+
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+
+using namespace ot;
+
+// Logs a message and adds current time (sNow) as "<hours>:<min>:<secs>.<msec>"
+#define Log(...)                                                                                          \
+    printf("%02u:%02u:%02u.%03u " OT_FIRST_ARG(__VA_ARGS__) "\n", (sNow / 36000000), (sNow / 60000) % 60, \
+           (sNow / 1000) % 60, sNow % 1000 OT_REST_ARGS(__VA_ARGS__))
+
+static constexpr uint32_t kInfraIfIndex     = 1;
+static const char         kInfraIfAddress[] = "fe80::1";
+
+static constexpr uint32_t kValidLitime       = 2000;
+static constexpr uint32_t kPreferredLifetime = 1800;
+
+static otInstance *sInstance;
+
+static uint32_t sNow = 0;
+static uint32_t sAlarmTime;
+static bool     sAlarmOn = false;
+
+static otRadioFrame sRadioTxFrame;
+static uint8_t      sRadioTxFramePsdu[OT_RADIO_FRAME_MAX_SIZE];
+static bool         sRadioTxOngoing = false;
+
+using Icmp6Packet = Ip6::Nd::RouterAdvertMessage::Icmp6Packet;
+
+enum ExpectedPio
+{
+    kNoPio,                     // Expect to see no PIO in RA.
+    kPioAdvertisingLocalOnLink, // Expect to see local on-link prefix advertised (non-zero preferred lifetime).
+    kPioDeprecatingLocalOnLink, // Expect to see local on-link prefix deprecated (zero preferred lifetime).
+};
+
+static Ip6::Address sInfraIfAddress;
+
+bool        sRsEmitted;         // Indicates if an RS message was emitted by BR.
+bool        sRaValidated;       // Indicates if an RA was emitted by BR and successfully validated.
+bool        sSawExpectedRio;    // Indicates if the emitted RA by BR contained an RIO with `sExpectedRioPrefix`
+ExpectedPio sExpectedPio;       // Expected PIO in the emitted RA by BR (MUST be seen in RA to set `sRaValidated`).
+Ip6::Prefix sExpectedRioPrefix; // Expected RIO prefix to see in RA (MUST be seen to set `sSawExpectedRio`).
+
+//----------------------------------------------------------------------------------------------------------------------
+// Function prototypes
+
+void        ProcessRadioTxAndTasklets(void);
+void        AdvanceTime(uint32_t aDuration);
+void        LogRouterAdvert(const Icmp6Packet &aPacket);
+void        ValidateRouterAdvert(const Icmp6Packet &aPacket);
+const char *PreferenceToString(uint8_t aPreference);
+void        SendRouterAdvert(const Ip6::Address &aAddress, const Icmp6Packet &aPacket);
+
+//----------------------------------------------------------------------------------------------------------------------
+// `otPlatRadio
+
+extern "C" {
+
+otError otPlatRadioTransmit(otInstance *, otRadioFrame *)
+{
+    sRadioTxOngoing = true;
+
+    return OT_ERROR_NONE;
+}
+
+otRadioFrame *otPlatRadioGetTransmitBuffer(otInstance *)
+{
+    return &sRadioTxFrame;
+}
+
+//----------------------------------------------------------------------------------------------------------------------
+// `otPlatAlaram
+
+void otPlatAlarmMilliStop(otInstance *)
+{
+    sAlarmOn = false;
+}
+
+void otPlatAlarmMilliStartAt(otInstance *, uint32_t aT0, uint32_t aDt)
+{
+    sAlarmOn   = true;
+    sAlarmTime = aT0 + aDt;
+}
+
+uint32_t otPlatAlarmMilliGetNow(void)
+{
+    return sNow;
+}
+
+//---------------------------------------------------------------------------------------------------------------------
+// otPlatInfraIf
+
+bool otPlatInfraIfHasAddress(uint32_t aInfraIfIndex, const otIp6Address *aAddress)
+{
+    VerifyOrQuit(aInfraIfIndex == kInfraIfIndex);
+
+    return AsCoreType(aAddress) == sInfraIfAddress;
+}
+
+otError otPlatInfraIfSendIcmp6Nd(uint32_t            aInfraIfIndex,
+                                 const otIp6Address *aDestAddress,
+                                 const uint8_t *     aBuffer,
+                                 uint16_t            aBufferLength)
+{
+    Icmp6Packet packet;
+
+    Log("otPlatInfraIfSendIcmp6Nd(aDestAddr: %s, aBufferLength:%u)", AsCoreType(aDestAddress).ToString().AsCString(),
+        aBufferLength);
+
+    VerifyOrQuit(aInfraIfIndex == kInfraIfIndex);
+
+    packet.Init(aBuffer, aBufferLength);
+
+    VerifyOrQuit(aBufferLength >= sizeof(Ip6::Icmp::Header));
+
+    switch (reinterpret_cast<const Ip6::Icmp::Header *>(aBuffer)->GetType())
+    {
+    case Ip6::Icmp::Header::kTypeRouterSolicit:
+        Log("  Router Solicit message");
+        sRsEmitted = true;
+        break;
+
+    case Ip6::Icmp::Header::kTypeRouterAdvert:
+        Log("  Router Advertisement message");
+        LogRouterAdvert(packet);
+        ValidateRouterAdvert(packet);
+        sRaValidated = true;
+        break;
+
+    default:
+        VerifyOrQuit(false, "Bad ICMP6 type");
+    }
+
+    return OT_ERROR_NONE;
+}
+
+} // extern "C"
+
+//---------------------------------------------------------------------------------------------------------------------
+
+void ProcessRadioTxAndTasklets(void)
+{
+    do
+    {
+        if (sRadioTxOngoing)
+        {
+            sRadioTxOngoing = false;
+            otPlatRadioTxStarted(sInstance, &sRadioTxFrame);
+            otPlatRadioTxDone(sInstance, &sRadioTxFrame, nullptr, OT_ERROR_NONE);
+        }
+
+        otTaskletsProcess(sInstance);
+    } while (otTaskletsArePending(sInstance));
+}
+
+void AdvanceTime(uint32_t aDuration)
+{
+    uint32_t time = sNow + aDuration;
+
+    Log("AdvanceTime for %u.%03u", aDuration / 1000, aDuration % 1000);
+
+    while (sAlarmTime <= time)
+    {
+        ProcessRadioTxAndTasklets();
+        sNow = sAlarmTime;
+        otPlatAlarmMilliFired(sInstance);
+    }
+
+    ProcessRadioTxAndTasklets();
+    sNow = time;
+}
+
+void ValidateRouterAdvert(const Icmp6Packet &aPacket)
+{
+    Ip6::Nd::RouterAdvertMessage raMsg(aPacket);
+
+    VerifyOrQuit(raMsg.IsValid());
+
+    for (const Ip6::Nd::Option &option : raMsg)
+    {
+        switch (option.GetType())
+        {
+        case Ip6::Nd::Option::kTypePrefixInfo:
+        {
+            const Ip6::Nd::PrefixInfoOption &pio = static_cast<const Ip6::Nd::PrefixInfoOption &>(option);
+            Ip6::Prefix                      prefix;
+            Ip6::Prefix                      localOnLink;
+
+            VerifyOrQuit(pio.IsValid());
+            pio.GetPrefix(prefix);
+
+            VerifyOrQuit(sExpectedPio != kNoPio, "Received RA contain an unexpected PIO");
+
+            SuccessOrQuit(otBorderRoutingGetOnLinkPrefix(sInstance, &localOnLink));
+            VerifyOrQuit(prefix == localOnLink);
+
+            if (sExpectedPio == kPioAdvertisingLocalOnLink)
+            {
+                VerifyOrQuit(pio.GetPreferredLifetime() > 0, "On link prefix is deprecated unexpectedly");
+            }
+            else
+            {
+                VerifyOrQuit(pio.GetPreferredLifetime() == 0, "On link prefix is not deprecated");
+            }
+
+            break;
+        }
+
+        case Ip6::Nd::Option::kTypeRouteInfo:
+        {
+            const Ip6::Nd::RouteInfoOption &rio = static_cast<const Ip6::Nd::RouteInfoOption &>(option);
+            Ip6::Prefix                     prefix;
+
+            VerifyOrQuit(rio.IsValid());
+            rio.GetPrefix(prefix);
+
+            if (prefix == sExpectedRioPrefix)
+            {
+                sSawExpectedRio = true;
+            }
+
+            break;
+        }
+
+        default:
+            VerifyOrQuit(false, "Unexpected option type in RA msg");
+        }
+    }
+}
+
+void LogRouterAdvert(const Icmp6Packet &aPacket)
+{
+    Ip6::Nd::RouterAdvertMessage raMsg(aPacket);
+
+    VerifyOrQuit(raMsg.IsValid());
+
+    Log("     RA header - lifetime %u, prf:%s", raMsg.GetHeader().GetRouterLifetime(),
+        PreferenceToString(raMsg.GetHeader().GetDefaultRouterPreference()));
+
+    for (const Ip6::Nd::Option &option : raMsg)
+    {
+        switch (option.GetType())
+        {
+        case Ip6::Nd::Option::kTypePrefixInfo:
+        {
+            const Ip6::Nd::PrefixInfoOption &pio = static_cast<const Ip6::Nd::PrefixInfoOption &>(option);
+            Ip6::Prefix                      prefix;
+
+            VerifyOrQuit(pio.IsValid());
+            pio.GetPrefix(prefix);
+            Log("     PIO - %s, flags:%s%s, valid:%u, preferred:%u", prefix.ToString().AsCString(),
+                pio.IsOnLinkFlagSet() ? "L" : "", pio.IsAutoAddrConfigFlagSet() ? "A" : "", pio.GetValidLifetime(),
+                pio.GetPreferredLifetime());
+            break;
+        }
+
+        case Ip6::Nd::Option::kTypeRouteInfo:
+        {
+            const Ip6::Nd::RouteInfoOption &rio = static_cast<const Ip6::Nd::RouteInfoOption &>(option);
+            Ip6::Prefix                     prefix;
+
+            VerifyOrQuit(rio.IsValid());
+            rio.GetPrefix(prefix);
+            Log("     RIO - %s, prf:%s, lifetime:%u", prefix.ToString().AsCString(),
+                PreferenceToString(rio.GetPreference()), rio.GetRouteLifetime());
+            break;
+        }
+
+        default:
+            VerifyOrQuit(false, "Bad option type in RA msg");
+        }
+    }
+}
+
+const char *PreferenceToString(uint8_t aPreference)
+{
+    const char *str = "";
+
+    switch (aPreference)
+    {
+    case NetworkData::kRoutePreferenceLow:
+        str = "low";
+        break;
+
+    case NetworkData::kRoutePreferenceMedium:
+        str = "med";
+        break;
+
+    case NetworkData::kRoutePreferenceHigh:
+        str = "high";
+        break;
+
+    default:
+        break;
+    }
+
+    return str;
+}
+
+void SendRouterAdvert(const Ip6::Address &aAddress, const Icmp6Packet &aPacket)
+{
+    otPlatInfraIfRecvIcmp6Nd(sInstance, kInfraIfIndex, &aAddress, aPacket.GetBytes(), aPacket.GetLength());
+}
+
+Ip6::Prefix PrefixFromString(const char *aString, uint8_t aPrefixLength)
+{
+    Ip6::Prefix prefix;
+
+    SuccessOrQuit(AsCoreType(&prefix.mPrefix).FromString(aString));
+    prefix.mLength = aPrefixLength;
+
+    return prefix;
+}
+
+Ip6::Address AddressFromString(const char *aString)
+{
+    Ip6::Address address;
+
+    SuccessOrQuit(address.FromString(aString));
+
+    return address;
+}
+
+void TestRoutingManager(void)
+{
+    Instance &                                        instance = *static_cast<Instance *>(testInitInstance());
+    BorderRouter::RoutingManager &                    rm       = instance.Get<BorderRouter::RoutingManager>();
+    Ip6::Prefix                                       localOnLink;
+    Ip6::Prefix                                       localOmr;
+    Ip6::Prefix                                       onLinkPrefix   = PrefixFromString("2000:abba:baba::", 64);
+    Ip6::Prefix                                       routePrefix    = PrefixFromString("2000:1234:5678::", 64);
+    Ip6::Prefix                                       omrPrefix      = PrefixFromString("2000:0000:1111:4444::", 64);
+    Ip6::Address                                      routerAddressA = AddressFromString("fd00::aaaa");
+    Ip6::Address                                      routerAddressB = AddressFromString("fd00::bbbb");
+    BorderRouter::RoutingManager::PrefixTableIterator iter;
+    BorderRouter::RoutingManager::PrefixTableEntry    entry;
+    NetworkData::Iterator                             iterator;
+    NetworkData::OnMeshPrefixConfig                   prefixConfig;
+    NetworkData::ExternalRouteConfig                  routeConfig;
+    uint8_t                                           counter;
+    uint8_t                                           buffer[800];
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Initialize OT instance.
+
+    sNow      = 0;
+    sInstance = &instance;
+
+    memset(&sRadioTxFrame, 0, sizeof(sRadioTxFrame));
+    sRadioTxFrame.mPsdu = sRadioTxFramePsdu;
+
+    SuccessOrQuit(sInfraIfAddress.FromString(kInfraIfAddress));
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Initialize Border Router and start Thread operation.
+
+    SuccessOrQuit(otBorderRoutingInit(sInstance, kInfraIfIndex, /* aInfraIfIsRunning */ true));
+
+    SuccessOrQuit(otLinkSetPanId(sInstance, 0x1234));
+    SuccessOrQuit(otIp6SetEnabled(sInstance, true));
+    SuccessOrQuit(otThreadSetEnabled(sInstance, true));
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Ensure device starts as leader.
+
+    AdvanceTime(10000);
+
+    VerifyOrQuit(otThreadGetDeviceRole(sInstance) == OT_DEVICE_ROLE_LEADER);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Start Routing Manager. Check emitted RS and RA messages.
+
+    sRsEmitted      = false;
+    sRaValidated    = false;
+    sSawExpectedRio = false;
+    sExpectedPio    = kPioAdvertisingLocalOnLink;
+
+    Log("Starting RoutingManager");
+
+    SuccessOrQuit(rm.SetEnabled(true));
+
+    SuccessOrQuit(rm.GetOnLinkPrefix(localOnLink));
+    SuccessOrQuit(rm.GetOmrPrefix(localOmr));
+
+    Log("Local on-link prefix is %s", localOnLink.ToString().AsCString());
+    Log("Local OMR prefix is %s", localOmr.ToString().AsCString());
+
+    sExpectedRioPrefix = localOmr;
+
+    AdvanceTime(30000);
+
+    VerifyOrQuit(sRsEmitted);
+    VerifyOrQuit(sRaValidated);
+    VerifyOrQuit(sSawExpectedRio);
+    Log("Received RA was validated");
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data to include the local OMR and on-link prefix.
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see OMR prefix in net data as on-mesh prefix.
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig));
+    VerifyOrQuit(prefixConfig.GetPrefix() == localOmr);
+    VerifyOrQuit(prefixConfig.mStable == true);
+    VerifyOrQuit(prefixConfig.mSlaac == true);
+    VerifyOrQuit(prefixConfig.mPreferred == true);
+    VerifyOrQuit(prefixConfig.mOnMesh == true);
+    VerifyOrQuit(prefixConfig.mDefaultRoute == false);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNotFound);
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see local on-link prefix in net data as external route.
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig));
+    VerifyOrQuit(routeConfig.GetPrefix() == localOnLink);
+    VerifyOrQuit(routeConfig.mStable == true);
+    VerifyOrQuit(routeConfig.mPreference == NetworkData::kRoutePreferenceMedium);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNotFound);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Send an RA from router A with a new on-link (PIO) and route prefix (RIO).
+
+    {
+        Ip6::Nd::RouterAdvertMessage raMsg(Ip6::Nd::RouterAdvertMessage::Header(), buffer);
+
+        SuccessOrQuit(raMsg.AppendPrefixInfoOption(onLinkPrefix, kValidLitime, kPreferredLifetime));
+        SuccessOrQuit(raMsg.AppendRouteInfoOption(routePrefix, kValidLitime, NetworkData::kRoutePreferenceMedium));
+
+        SendRouterAdvert(routerAddressA, raMsg.GetAsPacket());
+
+        Log("Send RA from router A");
+        LogRouterAdvert(raMsg.GetAsPacket());
+    }
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check that the local on-link prefix is now deprecating in the new RA.
+
+    sRaValidated    = false;
+    sSawExpectedRio = false;
+    sExpectedPio    = kPioDeprecatingLocalOnLink;
+
+    AdvanceTime(10000);
+    VerifyOrQuit(sRaValidated);
+    VerifyOrQuit(sSawExpectedRio);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check the discovered prefix table and ensure info from router A
+    // is present in the table.
+
+    counter = 0;
+
+    rm.InitPrefixTableIterator(iter);
+
+    while (rm.GetNextPrefixTableEntry(iter, entry) == kErrorNone)
+    {
+        counter++;
+        VerifyOrQuit(AsCoreType(&entry.mRouterAddress) == routerAddressA);
+
+        if (entry.mIsOnLink)
+        {
+            VerifyOrQuit(AsCoreType(&entry.mPrefix) == onLinkPrefix);
+            VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+            VerifyOrQuit(entry.mPreferredLifetime = kPreferredLifetime);
+        }
+        else
+        {
+            VerifyOrQuit(AsCoreType(&entry.mPrefix) == routePrefix);
+            VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+            VerifyOrQuit(static_cast<int8_t>(entry.mRoutePreference) == NetworkData::kRoutePreferenceMedium);
+        }
+    }
+
+    VerifyOrQuit(counter == 2);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data to include new prefixes from router A.
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see OMR prefix in net data as on-mesh prefix.
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig));
+    VerifyOrQuit(prefixConfig.GetPrefix() == localOmr);
+    VerifyOrQuit(prefixConfig.mStable == true);
+    VerifyOrQuit(prefixConfig.mSlaac == true);
+    VerifyOrQuit(prefixConfig.mPreferred == true);
+    VerifyOrQuit(prefixConfig.mOnMesh == true);
+    VerifyOrQuit(prefixConfig.mDefaultRoute == false);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNotFound);
+
+    iterator = NetworkData::kIteratorInit;
+
+    counter = 0;
+
+    // We expect to see 3 entries, our local on link and new prefixes from router A.
+    while (instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNone)
+    {
+        VerifyOrQuit((routeConfig.GetPrefix() == localOnLink) || (routeConfig.GetPrefix() == onLinkPrefix) ||
+                     (routeConfig.GetPrefix() == routePrefix));
+        VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceMedium);
+        counter++;
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Send an RA from router B with same route prefix (RIO) but with
+    // high route preference.
+
+    {
+        Ip6::Nd::RouterAdvertMessage raMsg(Ip6::Nd::RouterAdvertMessage::Header(), buffer);
+
+        SuccessOrQuit(raMsg.AppendRouteInfoOption(routePrefix, kValidLitime, NetworkData::kRoutePreferenceHigh));
+
+        SendRouterAdvert(routerAddressB, raMsg.GetAsPacket());
+
+        Log("Send RA from router B");
+        LogRouterAdvert(raMsg.GetAsPacket());
+    }
+
+    AdvanceTime(10000);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check the discovered prefix table and ensure info from router B
+    // is also included in the table.
+
+    counter = 0;
+
+    rm.InitPrefixTableIterator(iter);
+
+    while (rm.GetNextPrefixTableEntry(iter, entry) == kErrorNone)
+    {
+        const Ip6::Address &routerAddr = AsCoreType(&entry.mRouterAddress);
+        counter++;
+
+        if (routerAddr == routerAddressA)
+        {
+            if (entry.mIsOnLink)
+            {
+                VerifyOrQuit(AsCoreType(&entry.mPrefix) == onLinkPrefix);
+                VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+                VerifyOrQuit(entry.mPreferredLifetime = kPreferredLifetime);
+            }
+            else
+            {
+                VerifyOrQuit(AsCoreType(&entry.mPrefix) == routePrefix);
+                VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+                VerifyOrQuit(static_cast<int8_t>(entry.mRoutePreference) == NetworkData::kRoutePreferenceMedium);
+            }
+        }
+        else if (routerAddr == routerAddressB)
+        {
+            VerifyOrQuit(!entry.mIsOnLink);
+            VerifyOrQuit(AsCoreType(&entry.mPrefix) == routePrefix);
+            VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+            VerifyOrQuit(static_cast<int8_t>(entry.mRoutePreference) == NetworkData::kRoutePreferenceHigh);
+        }
+        else
+        {
+            VerifyOrQuit(false, "Unexpected entry in prefix table with unknown router address");
+        }
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data.
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see OMR prefix in net data as on-mesh prefix
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig));
+    VerifyOrQuit(prefixConfig.GetPrefix() == localOmr);
+    VerifyOrQuit(prefixConfig.mStable == true);
+    VerifyOrQuit(prefixConfig.mSlaac == true);
+    VerifyOrQuit(prefixConfig.mPreferred == true);
+    VerifyOrQuit(prefixConfig.mOnMesh == true);
+    VerifyOrQuit(prefixConfig.mDefaultRoute == false);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNotFound);
+
+    iterator = NetworkData::kIteratorInit;
+
+    counter = 0;
+
+    // We expect to see 3 entries, our local on link and new prefixes
+    // from router A and B. The `routePrefix` now should have high
+    // preference.
+
+    while (instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNone)
+    {
+        counter++;
+
+        if (routeConfig.GetPrefix() == routePrefix)
+        {
+            VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceHigh);
+        }
+        else
+        {
+            VerifyOrQuit((routeConfig.GetPrefix() == localOnLink) || (routeConfig.GetPrefix() == onLinkPrefix));
+            VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceMedium);
+        }
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Send an RA from router B removing the route prefix.
+
+    {
+        Ip6::Nd::RouterAdvertMessage raMsg(Ip6::Nd::RouterAdvertMessage::Header(), buffer);
+
+        SuccessOrQuit(raMsg.AppendRouteInfoOption(routePrefix, 0, NetworkData::kRoutePreferenceHigh));
+
+        SendRouterAdvert(routerAddressB, raMsg.GetAsPacket());
+
+        Log("Send RA from router B");
+        LogRouterAdvert(raMsg.GetAsPacket());
+    }
+
+    AdvanceTime(10000);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check the discovered prefix table and ensure info from router B
+    // is now removed from the table.
+
+    counter = 0;
+
+    rm.InitPrefixTableIterator(iter);
+
+    while (rm.GetNextPrefixTableEntry(iter, entry) == kErrorNone)
+    {
+        counter++;
+
+        VerifyOrQuit(AsCoreType(&entry.mRouterAddress) == routerAddressA);
+
+        if (entry.mIsOnLink)
+        {
+            VerifyOrQuit(AsCoreType(&entry.mPrefix) == onLinkPrefix);
+            VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+            VerifyOrQuit(entry.mPreferredLifetime = kPreferredLifetime);
+        }
+        else
+        {
+            VerifyOrQuit(AsCoreType(&entry.mPrefix) == routePrefix);
+            VerifyOrQuit(entry.mValidLifetime = kValidLitime);
+            VerifyOrQuit(static_cast<int8_t>(entry.mRoutePreference) == NetworkData::kRoutePreferenceMedium);
+        }
+    }
+
+    VerifyOrQuit(counter == 2);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data, all prefixes should be again at medium preference.
+
+    counter  = 0;
+    iterator = NetworkData::kIteratorInit;
+
+    while (instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNone)
+    {
+        counter++;
+
+        VerifyOrQuit((routeConfig.GetPrefix() == localOnLink) || (routeConfig.GetPrefix() == onLinkPrefix) ||
+                     (routeConfig.GetPrefix() == routePrefix));
+        VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceMedium);
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Add a new OMR prefix directly into net data. The new prefix should
+    // be favored over the local OMR prefix.
+
+    prefixConfig.Clear();
+    prefixConfig.mPrefix       = omrPrefix;
+    prefixConfig.mStable       = true;
+    prefixConfig.mSlaac        = true;
+    prefixConfig.mPreferred    = true;
+    prefixConfig.mOnMesh       = true;
+    prefixConfig.mDefaultRoute = false;
+    prefixConfig.mPreference   = NetworkData::kRoutePreferenceMedium;
+
+    SuccessOrQuit(otBorderRouterAddOnMeshPrefix(sInstance, &prefixConfig));
+    SuccessOrQuit(otBorderRouterRegister(sInstance));
+
+    AdvanceTime(100);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Make sure BR emits RA with new OMR prefix now.
+
+    sRaValidated       = false;
+    sSawExpectedRio    = false;
+    sExpectedRioPrefix = omrPrefix;
+
+    AdvanceTime(20000);
+
+    VerifyOrQuit(sRaValidated);
+    VerifyOrQuit(sSawExpectedRio);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data. We should now see that the local OMR prefix
+    // is removed.
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see new OMR prefix in net data.
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig));
+    VerifyOrQuit(prefixConfig.GetPrefix() == omrPrefix);
+    VerifyOrQuit(prefixConfig.mStable == true);
+    VerifyOrQuit(prefixConfig.mSlaac == true);
+    VerifyOrQuit(prefixConfig.mPreferred == true);
+    VerifyOrQuit(prefixConfig.mOnMesh == true);
+    VerifyOrQuit(prefixConfig.mDefaultRoute == false);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNotFound);
+
+    counter  = 0;
+    iterator = NetworkData::kIteratorInit;
+
+    while (instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNone)
+    {
+        counter++;
+
+        VerifyOrQuit((routeConfig.GetPrefix() == localOnLink) || (routeConfig.GetPrefix() == onLinkPrefix) ||
+                     (routeConfig.GetPrefix() == routePrefix));
+        VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceMedium);
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Remove the OMR prefix previously added in net data.
+
+    SuccessOrQuit(otBorderRouterRemoveOnMeshPrefix(sInstance, &omrPrefix));
+    SuccessOrQuit(otBorderRouterRegister(sInstance));
+
+    AdvanceTime(100);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Make sure BR emits RA with local OMR prefix again.
+
+    sRaValidated       = false;
+    sSawExpectedRio    = false;
+    sExpectedRioPrefix = localOmr;
+
+    AdvanceTime(20000);
+
+    VerifyOrQuit(sRaValidated);
+    VerifyOrQuit(sSawExpectedRio);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+    // Check Network Data. We should see that the local OMR prefix is
+    // added again.
+
+    iterator = NetworkData::kIteratorInit;
+
+    // We expect to see new OMR prefix in net data as on-mesh prefix.
+    SuccessOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig));
+    VerifyOrQuit(prefixConfig.GetPrefix() == localOmr);
+    VerifyOrQuit(prefixConfig.mStable == true);
+    VerifyOrQuit(prefixConfig.mSlaac == true);
+    VerifyOrQuit(prefixConfig.mPreferred == true);
+    VerifyOrQuit(prefixConfig.mOnMesh == true);
+    VerifyOrQuit(prefixConfig.mDefaultRoute == false);
+
+    VerifyOrQuit(instance.Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, prefixConfig) == kErrorNotFound);
+
+    counter  = 0;
+    iterator = NetworkData::kIteratorInit;
+
+    while (instance.Get<NetworkData::Leader>().GetNextExternalRoute(iterator, routeConfig) == kErrorNone)
+    {
+        counter++;
+
+        VerifyOrQuit((routeConfig.GetPrefix() == localOnLink) || (routeConfig.GetPrefix() == onLinkPrefix) ||
+                     (routeConfig.GetPrefix() == routePrefix));
+        VerifyOrQuit(static_cast<int8_t>(routeConfig.mPreference) == NetworkData::kRoutePreferenceMedium);
+    }
+
+    VerifyOrQuit(counter == 3);
+
+    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+    Log("End of test");
+
+    testFreeInstance(&instance);
+}
+
+#endif // OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+
+int main(void)
+{
+#if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
+    TestRoutingManager();
+    printf("All tests passed\n");
+#else
+    printf("BORDER_ROUTING feature is not enabled\n");
+#endif
+
+    return 0;
+}