From d6107c5f53e506b9565dd16aaef1e1aa773785f0 Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@nestlabs.com>
Date: Thu, 7 Jul 2016 08:41:25 -0700
Subject: [PATCH] Forward multicast datagrams when operating in NCP mode.
 (#243)

---
 src/core/net/ip6.cpp | 32 +++++++++++++++++++++++++++-----
 src/core/net/ip6.hpp |  7 ++++---
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/src/core/net/ip6.cpp b/src/core/net/ip6.cpp
index 673cdbc26..152139db3 100644
--- a/src/core/net/ip6.cpp
+++ b/src/core/net/ip6.cpp
@@ -304,6 +304,29 @@ exit:
     return error;
 }
 
+void Ip6::ProcessReceiveCallback(Message &aMessage)
+{
+    ThreadError error = kThreadError_None;
+    Message *messageCopy;
+
+    VerifyOrExit(sReceiveIp6DatagramCallback != NULL, ;);
+
+    // make a copy of the datagram to pass to host
+    VerifyOrExit((messageCopy = NewMessage(0)) != NULL, ;);
+    SuccessOrExit(error = messageCopy->SetLength(aMessage.GetLength()));
+    VerifyOrExit(aMessage.CopyTo(0, 0, aMessage.GetLength(), *messageCopy) == aMessage.GetLength(),
+                 error = kThreadError_Drop);
+
+    sReceiveIp6DatagramCallback(messageCopy);
+
+exit:
+
+    if (error != kThreadError_None && messageCopy != NULL)
+    {
+        Message::Free(*messageCopy);
+    }
+}
+
 ThreadError Ip6::HandleDatagram(Message &message, Netif *netif, uint8_t interfaceId, const void *linkMessageInfo,
                                 bool fromLocalHost)
 {
@@ -383,13 +406,12 @@ ThreadError Ip6::HandleDatagram(Message &message, Netif *netif, uint8_t interfac
     // process IPv6 Payload
     if (receive)
     {
-        SuccessOrExit(HandlePayload(message, messageInfo, nextHeader));
-
-        if (sReceiveIp6DatagramCallback != NULL && fromLocalHost == false)
+        if (fromLocalHost == false)
         {
-            sReceiveIp6DatagramCallback(&message);
-            ExitNow(error = kThreadError_None);
+            ProcessReceiveCallback(message);
         }
+
+        SuccessOrExit(HandlePayload(message, messageInfo, nextHeader));
     }
 
     if (forward)
diff --git a/src/core/net/ip6.hpp b/src/core/net/ip6.hpp
index 1fbb270d1..27313ed74 100644
--- a/src/core/net/ip6.hpp
+++ b/src/core/net/ip6.hpp
@@ -530,7 +530,6 @@ public:
      */
     static uint16_t UpdateChecksum(uint16_t aChecksum, uint16_t aValue);
 
-
     /**
      * This static method updates a checksum.
      *
@@ -571,12 +570,14 @@ public:
     /**
      * This function registers a callback to provide received raw IPv6 datagrams.
      *
-     * @param[in]  aCallback  A pointer to a function that is called when an IPv6 datagram is received or NULL to disable
-     *                        the callback.
+     * @param[in]  aCallback  A pointer to a function that is called when an IPv6 datagram is received or NULL to
+     *                        disable the callback.
      *
      */
     static void SetReceiveDatagramCallback(otReceiveIp6DatagramCallback aCallback);
 
+private:
+    static void ProcessReceiveCallback(Message &aMessage);
 };
 
 /**