[fuzz] allow border router services to start (#11561)

tests/fuzz/radio-one-node.cpp

@@ -96,6 +96,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 
     node.GetInstance().SetLogLevel(kLogLevelInfo);
 
+    node.GetInstance().Get<BorderRouter::RoutingManager>().Init(/* aInfraIfIndex */ 1, /* aInfraIfIsRunning */ true);
+    node.GetInstance().Get<BorderRouter::RoutingManager>().SetEnabled(true);
     node.GetInstance().Get<Srp::Server>().SetAutoEnableMode(true);
     node.GetInstance().Get<BorderRouter::RoutingManager>().SetDhcp6PdEnabled(true);
     node.GetInstance().Get<BorderRouter::RoutingManager>().SetNat64PrefixManagerEnabled(true);
@@ -105,8 +107,9 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
     Log("Form network");
 
     node.Form();
-    nexus.AdvanceTime(13 * 1000);
+    nexus.AdvanceTime(60 * 1000);
     VerifyOrQuit(node.Get<Mle::Mle>().IsLeader());
+    VerifyOrQuit(node.Get<Srp::Server>().GetState() == Srp::Server::kStateRunning);
 
     Log("---------------------------------------------------------------------------------------");
     Log("Fuzz");

tests/nexus/CMakeLists.txt

@@ -42,6 +42,7 @@ set(COMMON_COMPILE_OPTIONS
 add_library(ot-nexus-platform
     platform/nexus_alarm.cpp
     platform/nexus_core.cpp
+    platform/nexus_infra_if.cpp
     platform/nexus_mdns.cpp
     platform/nexus_misc.cpp
     platform/nexus_node.cpp

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

@@ -49,7 +49,6 @@
 #define OPENTHREAD_CONFIG_BORDER_ROUTER_ENABLE 1
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_DHCP6_PD_ENABLE 1
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE 1
-#define OPENTHREAD_CONFIG_BORDER_ROUTING_MOCK_PLAT_APIS_ENABLE 1
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_USE_HEAP_ENABLE 1
 #define OPENTHREAD_CONFIG_CHANNEL_MANAGER_ENABLE 1
 #define OPENTHREAD_CONFIG_CHANNEL_MONITOR_ENABLE 1

tests/nexus/platform/nexus_infra_if.cpp

@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2025, 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/platform/infra_if.h>
+
+namespace ot {
+namespace Nexus {
+
+extern "C" {
+
+bool otPlatInfraIfHasAddress(uint32_t, const otIp6Address *) { return false; }
+
+otError otPlatInfraIfSendIcmp6Nd(uint32_t, const otIp6Address *, const uint8_t *, uint16_t) { return OT_ERROR_NONE; }
+
+otError otPlatInfraIfDiscoverNat64Prefix(uint32_t) { return OT_ERROR_NOT_IMPLEMENTED; }
+
+} // extern "C"
+
+} // namespace Nexus
+} // namespace ot