[ncp] add dhcp6 client support (#2833)

src/ncp/ncp_base.cpp

@@ -633,6 +633,10 @@ NcpBase::NcpBase(Instance *aInstance)
 
     memset(&mResponseQueue, 0, sizeof(mResponseQueue));
 
+#if OPENTHREAD_ENABLE_DHCP6_CLIENT
+    memset(mDhcpAddresses, 0, sizeof(mDhcpAddresses));
+#endif
+
 #if OPENTHREAD_MTD || OPENTHREAD_FTD
     otMessageQueueInit(&mMessageQueue);
     otSetStateChangedCallback(mInstance, &NcpBase::HandleStateChanged, this);

src/ncp/ncp_base.hpp

@@ -43,6 +43,7 @@
 #if OPENTHREAD_FTD
 #include <openthread/thread_ftd.h>
 #endif
+#include <openthread/dhcp6_client.h>
 #include <openthread/message.h>
 #include <openthread/ncp.h>
 #include <openthread/types.h>
@@ -864,6 +865,10 @@ protected:
     bool mDisableStreamWrite;
     bool mShouldEmitChildTableUpdate;
 
+#if OPENTHREAD_ENABLE_DHCP6_CLIENT
+    otDhcpAddress mDhcpAddresses[OPENTHREAD_CONFIG_NUM_DHCP_PREFIXES];
+#endif
+
 #if OPENTHREAD_FTD
 #if OPENTHREAD_CONFIG_ENABLE_STEERING_DATA_SET_OOB
     otExtAddress mSteeringDataAddress;

src/ncp/ncp_base_mtd.cpp

@@ -3008,6 +3008,10 @@ void NcpBase::ProcessThreadChangedFlags(void)
             {
                 mChangedPropsSet.AddProperty(SPINEL_PROP_THREAD_ON_MESH_NETS);
                 mChangedPropsSet.AddProperty(SPINEL_PROP_THREAD_OFF_MESH_ROUTES);
+
+#if OPENTHREAD_ENABLE_DHCP6_CLIENT
+                otDhcp6ClientUpdate(mInstance, mDhcpAddresses, OT_ARRAY_LENGTH(mDhcpAddresses), NULL);
+#endif
             }
 
             mThreadChangedFlags &= ~threadFlag;