-fix hang issue exposed when intensive traffic in dense network (#991)

-mSockAddr should not be reset when send response for CoAP CON message
-other code refinements

examples/platforms/cc2538/radio.c

@@ -364,6 +364,12 @@ void readFrame(void)
         sReceiveFrame.mLength = length;
         sReceiveFrame.mLqi = crcCorr & CC2538_LQI_BIT_MASK;
     }
+    else
+    {
+        // resets rxfifo
+        HWREG(RFCORE_SFR_RFST) = RFCORE_SFR_RFST_INSTR_FLUSHRX;
+        HWREG(RFCORE_SFR_RFST) = RFCORE_SFR_RFST_INSTR_FLUSHRX;
+    }
 
     // check for rxfifo overflow
     if ((HWREG(RFCORE_XREG_FSMSTAT1) & RFCORE_XREG_FSMSTAT1_FIFOP) != 0 &&
@@ -382,8 +388,7 @@ void cc2538RadioProcess(otInstance *aInstance)
     readFrame();
 
     if ((sState == kStateReceive && sReceiveFrame.mLength > 0) ||
-        (sState == kStateTransmit && sReceiveFrame.mLength > 0 &&
-         (sReceiveFrame.mPsdu[0] & IEEE802154_FRAME_TYPE_MASK) != IEEE802154_FRAME_TYPE_ACK))
+        (sState == kStateTransmit && sReceiveFrame.mLength > IEEE802154_ACK_LENGTH))
     {
 #if OPENTHREAD_ENABLE_DIAG
 
@@ -394,7 +399,14 @@ void cc2538RadioProcess(otInstance *aInstance)
         else
 #endif
         {
-            otPlatRadioReceiveDone(aInstance, &sReceiveFrame, sReceiveError);
+            // signal MAC layer for each received frame if promiscous is enabled
+            // otherwise only signal MAC layer for non-ACK frame
+            if (((HWREG(RFCORE_XREG_FRMFILT0) & RFCORE_XREG_FRMFILT0_FRAME_FILTER_EN) == 0) ||
+                (sReceiveFrame.mLength > IEEE802154_ACK_LENGTH))
+            {
+
+                otPlatRadioReceiveDone(aInstance, &sReceiveFrame, sReceiveError);
+            }
         }
     }
 

src/core/mac/mac.cpp

@@ -937,6 +937,7 @@ void Mac::SentFrame(ThreadError aError)
     }
 
     mTransmitAttempts = 0;
+    mCsmaAttempts = 0;
 
     if (sendFrame.GetAckRequest())
     {

src/core/net/ip6_address.cpp

@@ -117,6 +117,12 @@ bool Address::IsRoutingLocator(void) const
             mFields.m16[6] == HostSwap16(0xfe00));
 }
 
+bool Address::IsAnycastRoutingLocator(void) const
+{
+    return (mFields.m16[4] == HostSwap16(0x0000) && mFields.m16[5] == HostSwap16(0x00ff) &&
+            mFields.m16[6] == HostSwap16(0xfe00) && mFields.m8[14] == 0xfc);
+}
+
 bool Address::IsSubnetRouterAnycast(void) const
 {
     return (mFields.m32[2] == 0 && mFields.m32[3] == 0);
@@ -130,7 +136,7 @@ bool Address::IsReservedSubnetAnycast(void) const
 
 bool Address::IsIidReserved(void) const
 {
-    return IsSubnetRouterAnycast() || IsReservedSubnetAnycast();
+    return IsSubnetRouterAnycast() || IsReservedSubnetAnycast() || IsAnycastRoutingLocator();
 }
 
 

src/core/net/ip6_address.hpp

@@ -197,6 +197,15 @@ public:
      */
     bool IsRoutingLocator(void) const;
 
+    /**
+     * This method indicates whether or not the IPv6 address is an Anycast RLOC address.
+     *
+     * @retval TRUE   If the IPv6 address is an Anycast RLOC address.
+     * @retval FALSE  If the IPv6 address is not an Anycast RLOC address.
+     *
+     */
+    bool IsAnycastRoutingLocator(void) const;
+
     /**
      * This method indicates whether or not the IPv6 address is Subnet-Router Anycast (RFC 4291),
      *

src/core/net/ip6_mpl.hpp

@@ -396,7 +396,7 @@ public:
      * @returns The offset from the the transmission time to the end of trickle interval.
      *
      */
-    uint32_t GetIntervalOffset() const { return mIntervalOffset; }
+    uint8_t GetIntervalOffset() const { return mIntervalOffset; }
 
     /**
      * This method sets the offset from the transmission time to the end of trickle interval.

src/core/thread/address_resolver.cpp

@@ -305,7 +305,6 @@ void AddressResolver::SendAddressNotificationResponse(const Coap::Header &aReque
 
     SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
 
-    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
     SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
 
     otLogInfoArp("Sent address notification acknowledgment");
@@ -378,7 +377,6 @@ void AddressResolver::SendAddressErrorResponse(const Coap::Header &aRequestHeade
 
     SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
 
-    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
     SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
 
     otLogInfoArp("Sent address error notification acknowledgment");

src/core/thread/mesh_forwarder.cpp

@@ -451,35 +451,10 @@ exit:
     return error;
 }
 
-void MeshForwarder::MoveToResolving(const Ip6::Address &aDestination)
-{
-    Message *cur, *next;
-    Ip6::Address ip6Dst;
-
-    for (cur = mSendQueue.GetHead(); cur; cur = next)
-    {
-        next = cur->GetNext();
-
-        if (cur->GetType() != Message::kTypeIp6)
-        {
-            continue;
-        }
-
-        cur->Read(Ip6::Header::GetDestinationOffset(), sizeof(ip6Dst), &ip6Dst);
-
-        if (memcmp(&ip6Dst, &aDestination, sizeof(ip6Dst)) == 0)
-        {
-            mSendQueue.Dequeue(*cur);
-            mResolvingQueue.Enqueue(*cur);
-        }
-    }
-}
-
 Message *MeshForwarder::GetDirectTransmission()
 {
     Message *curMessage, *nextMessage;
     ThreadError error = kThreadError_None;
-    Ip6::Address ip6Dst;
 
     for (curMessage = mSendQueue.GetHead(); curMessage; curMessage = nextMessage)
     {
@@ -510,8 +485,8 @@ Message *MeshForwarder::GetDirectTransmission()
             ExitNow();
 
         case kThreadError_AddressQuery:
-            curMessage->Read(Ip6::Header::GetDestinationOffset(), sizeof(ip6Dst), &ip6Dst);
-            MoveToResolving(ip6Dst);
+            mSendQueue.Dequeue(*curMessage);
+            mResolvingQueue.Enqueue(*curMessage);
             continue;
 
         case kThreadError_Drop:
@@ -1256,8 +1231,6 @@ void MeshForwarder::HandleSentFrame(Mac::Frame &aFrame, ThreadError aError)
     mSendBusy = false;
     VerifyOrExit(mSendMessage != NULL, ;);
 
-    mSendMessage->SetOffset(mMessageNextOffset);
-
     aFrame.GetDstAddr(macDest);
 
     if ((neighbor = mMle.GetNeighbor(macDest)) != NULL)
@@ -1353,6 +1326,7 @@ void MeshForwarder::HandleSentFrame(Mac::Frame &aFrame, ThreadError aError)
         mSendQueue.Dequeue(*mSendMessage);
         mSendMessage->Free();
         mSendMessage = NULL;
+        mMessageNextOffset = 0;
     }
 
     mScheduleTransmissionTask.Post();

src/core/thread/mesh_forwarder.hpp

@@ -221,7 +221,6 @@ private:
                         const Mac::Address &aMacSource, const Mac::Address &aMacDest,
                         const ThreadMessageInfo &aMessageInfo);
     void HandleDataRequest(const Mac::Address &aMacSource, const ThreadMessageInfo &aMessageInfo);
-    void MoveToResolving(const Ip6::Address &aDestination);
     ThreadError SendPoll(Message &aMessage, Mac::Frame &aFrame);
     ThreadError SendMesh(Message &aMessage, Mac::Frame &aFrame);
     ThreadError SendFragment(Message &aMessage, Mac::Frame &aFrame);