[cli] new command to enable/disable discovery request callback (#8579)

This commit add `discover reqcallback {enable/disable}` CLI command
which registers callback to output whenever device gets a "MLE
Discovery Request". This command allows the callback to be explicitly
set when needed and avoid having it be enabled by default (since the
extra output from this callback can be treated as unexpected result by
tests that parse the CLI output).

src/cli/cli.cpp

@@ -145,10 +145,6 @@ Interpreter::Interpreter(Instance *aInstance, otCliOutputCallback aCallback, voi
 #endif
 #endif // OPENTHREAD_FTD || OPENTHREAD_MTD
 {
-#if OPENTHREAD_FTD
-    otThreadSetDiscoveryRequestCallback(GetInstancePtr(), &Interpreter::HandleDiscoveryRequest, this);
-#endif
-
     OutputPrompt();
 }
 
@@ -3024,6 +3020,36 @@ template <> otError Interpreter::Process<Cmd("discover")>(Arg aArgs[])
     otError  error        = OT_ERROR_NONE;
     uint32_t scanChannels = 0;
 
+#if OPENTHREAD_FTD
+    /**
+     * @cli discover reqcallback (enable,disable)
+     * @code
+     * discover reqcallback enable
+     * Done
+     * @endcode
+     * @cparam discover reqcallback @ca{enable|disable}
+     * @par api_copy
+     * #otThreadSetDiscoveryRequestCallback
+     */
+    if (aArgs[0] == "reqcallback")
+    {
+        bool                             enable;
+        otThreadDiscoveryRequestCallback callback = nullptr;
+        void                            *context  = nullptr;
+
+        SuccessOrExit(error = ParseEnableOrDisable(aArgs[1], enable));
+
+        if (enable)
+        {
+            callback = &Interpreter::HandleDiscoveryRequest;
+            context  = this;
+        }
+
+        otThreadSetDiscoveryRequestCallback(GetInstancePtr(), callback, context);
+        ExitNow();
+    }
+#endif // OPENTHREAD_FTD
+
     if (!aArgs[0].IsEmpty())
     {
         uint8_t channel;
@@ -7155,12 +7181,19 @@ void Interpreter::HandleDetachGracefullyResult(void)
     OutputResult(OT_ERROR_NONE);
 }
 
+#if OPENTHREAD_FTD
+void Interpreter::HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo *aInfo, void *aContext)
+{
+    static_cast<Interpreter *>(aContext)->HandleDiscoveryRequest(*aInfo);
+}
+
 void Interpreter::HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo &aInfo)
 {
     OutputFormat("~ Discovery Request from ");
     OutputExtAddress(aInfo.mExtAddress);
     OutputLine(": version=%u,joiner=%d", aInfo.mVersion, aInfo.mIsJoiner);
 }
+#endif
 
 #endif // OPENTHREAD_FTD || OPENTHREAD_MTD
 

src/cli/cli.hpp

@@ -503,11 +503,10 @@ private:
     static void HandleDetachGracefullyResult(void *aContext);
     void        HandleDetachGracefullyResult(void);
 
-    static void HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo *aInfo, void *aContext)
-    {
-        static_cast<Interpreter *>(aContext)->HandleDiscoveryRequest(*aInfo);
-    }
-    void HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo &aInfo);
+#if OPENTHREAD_FTD
+    static void HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo *aInfo, void *aContext);
+    void        HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo &aInfo);
+#endif
 
 #endif // OPENTHREAD_FTD || OPENTHREAD_MTD
 

tests/scripts/expect/cli-scan-discover.exp

@@ -57,6 +57,8 @@ expect "channel"
 expect -re {(\d+)}
 set channel $expect_out(1,string)
 expect_line "Done"
+send "discover reqcallback enable\n"
+expect_line "Done"
 
 switch_node 3
 send "scan $channel\n"