[ip6] change aFromNcpHost to false in otIp6Send (#7187)

src/core/api/ip6_api.cpp

@@ -135,7 +135,8 @@ void otIp6SetReceiveFilterEnabled(otInstance *aInstance, bool aEnabled)
 
 otError otIp6Send(otInstance *aInstance, otMessage *aMessage)
 {
-    return AsCoreType(aInstance).Get<Ip6::Ip6>().SendRaw(AsCoreType(aMessage));
+    return AsCoreType(aInstance).Get<Ip6::Ip6>().SendRaw(AsCoreType(aMessage),
+                                                         !OPENTHREAD_CONFIG_IP6_ALLOW_LOOP_BACK_HOST_DATAGRAMS);
 }
 
 otMessage *otIp6NewMessage(otInstance *aInstance, const otMessageSettings *aSettings)

src/core/config/ip6.h

@@ -187,4 +187,14 @@
 #define OPENTHREAD_CONFIG_TCP_ENABLE 1
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_IP6_ALLOW_LOOP_BACK_HOST_DATAGRAMS
+ *
+ * Define as 1 to allow IPv6 datagrams from Host to be looped back to Host.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_IP6_ALLOW_LOOP_BACK_HOST_DATAGRAMS
+#define OPENTHREAD_CONFIG_IP6_ALLOW_LOOP_BACK_HOST_DATAGRAMS 1
+#endif
+
 #endif // CONFIG_IP6_H_

src/core/net/ip6.cpp

@@ -307,7 +307,7 @@ Error Ip6::InsertMplOption(Message &aMessage, Header &aHeader, MessageInfo &aMes
 
             if ((messageCopy = aMessage.Clone()) != nullptr)
             {
-                IgnoreError(HandleDatagram(*messageCopy, nullptr, nullptr, true));
+                IgnoreError(HandleDatagram(*messageCopy, nullptr, nullptr, /* aFromNcpHost */ true));
                 otLogInfoIp6("Message copy for indirect transmission to sleepy children");
             }
             else
@@ -540,7 +540,7 @@ void Ip6::HandleSendQueue(void)
     while ((message = mSendQueue.GetHead()) != nullptr)
     {
         mSendQueue.Dequeue(*message);
-        IgnoreError(HandleDatagram(*message, nullptr, nullptr, false));
+        IgnoreError(HandleDatagram(*message, nullptr, nullptr, /* aFromNcpHost */ false));
     }
 }
 
@@ -1084,7 +1084,7 @@ exit:
     return error;
 }
 
-Error Ip6::SendRaw(Message &aMessage)
+Error Ip6::SendRaw(Message &aMessage, bool aFromNcpHost)
 {
     Error       error = kErrorNone;
     Header      header;
@@ -1103,7 +1103,7 @@ Error Ip6::SendRaw(Message &aMessage)
         SuccessOrExit(error = InsertMplOption(aMessage, header, messageInfo));
     }
 
-    error = HandleDatagram(aMessage, nullptr, nullptr, true);
+    error = HandleDatagram(aMessage, nullptr, nullptr, aFromNcpHost);
     freed = true;
 
 exit:

src/core/net/ip6.hpp

@@ -196,6 +196,7 @@ public:
      * processing is complete, including when a value other than `kErrorNone` is returned.
      *
      * @param[in]  aMessage          A reference to the message.
+     * @param[in]  aFromNcpHost      If the message was forwarded from the NCP Host.
      *
      * @retval kErrorNone     Successfully processed the message.
      * @retval kErrorDrop     Message was well-formed but not fully processed due to packet processing rules.
@@ -204,7 +205,7 @@ public:
      * @retval kErrorParse    Encountered a malformed header when processing the message.
      *
      */
-    Error SendRaw(Message &aMessage);
+    Error SendRaw(Message &aMessage, bool aFromNcpHost);
 
     /**
      * This method processes a received IPv6 datagram.

src/core/thread/mesh_forwarder_ftd.cpp

@@ -203,7 +203,7 @@ Error MeshForwarder::ForwardDuaToBackboneLink(Message &aMessage, const Ip6::Addr
     ttl++;
     aMessage.Write(Ip6::Header::kHopLimitFieldOffset, ttl);
 
-    IgnoreError(Get<Ip6::Ip6>().HandleDatagram(aMessage, nullptr, nullptr, false));
+    IgnoreError(Get<Ip6::Ip6>().HandleDatagram(aMessage, nullptr, nullptr, /* aFromNcpHost */ false));
 
 exit:
     return error;