[mdns] Change mDNS host name at runtime.

Signed-off-by: Cristian Bulacu <[email protected]>

src/cli/cli_mdns_server.cpp

@@ -88,7 +88,6 @@ template <> otError MdnsServer::Process<Cmd("hostname")>(Arg aArgs[])
     else
     {
         VerifyOrExit(aArgs[1].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
-
         error = otMdnsServerSetHostName(GetInstancePtr(), aArgs[0].GetCString());
     }
 

src/core/net/mdns_server.cpp

@@ -1389,20 +1389,32 @@ Error MdnsServer::AddAddress(const Ip6::Address &aIp6Address)
 
 Error MdnsServer::SetHostName(const char *aHostName)
 {
-    Error error = kErrorNone;
+    Error   error  = kErrorNone;
+    Prober *prober = nullptr;
 
     VerifyOrExit(aHostName != nullptr, error = kErrorInvalidArgs);
+    VerifyOrExit(Name::IsSubDomainOf(aHostName, kDefaultDomainName), error = kErrorInvalidArgs);
 
     if (mHostName.IsNull())
     {
         error = mHostName.Set(aHostName);
     }
     else
     {
-        error = StringMatch(mHostName.AsCString(), aHostName, kStringCaseInsensitiveMatch) ? kErrorNone : kErrorFailed;
+        VerifyOrExit(!StringMatch(mHostName.AsCString(), aHostName, kStringCaseInsensitiveMatch),
+                     error = kErrorDuplicated);
+        prober = AllocateProber(true, nullptr, 0);
+        VerifyOrExit(prober != nullptr, error = kErrorNoBufs);
+        VerifyOrExit(mHostName.Set(aHostName) != kErrorNoBufs, error = kErrorNoBufs);
+        mIsHostVerifiedUnique = false;
+        PublishHostAndServices(prober);
     }
 
 exit:
+    if (error == kErrorNoBufs && prober)
+    {
+        RemoveProbingInstance(prober->GetId());
+    }
     return error;
 }