Make IsRoutingLocator() more strict (#1660)

* make determine IsRoutingLocator more strict

* define Aloc16Mask and Rloc16ReservedBitMask.

* put the aloc16mask into Ip6::Address

src/core/net/dhcp6_server.cpp

@@ -162,7 +162,7 @@ ThreadError Dhcp6Server::UpdateService(void)
                 address->mFields.m16[4] = HostSwap16(0x0000);
                 address->mFields.m16[5] = HostSwap16(0x00ff);
                 address->mFields.m16[6] = HostSwap16(0xfe00);
-                address->mFields.m8[14] = Mle::kAloc16Mask;
+                address->mFields.m8[14] = Ip6::Address::kAloc16Mask;
                 address->mFields.m8[15] = lowpanContext.mContextId;
                 mAgentsAloc[i].mPrefixLength = 128;
                 mAgentsAloc[i].mPreferred = true;

src/core/net/ip6.cpp

@@ -593,7 +593,9 @@ ThreadError Ip6::ProcessReceiveCallback(const Message &aMessage, const MessageIn
     {
         // do not pass messages sent to/from an RLOC
         VerifyOrExit(!messageInfo.GetSockAddr().IsRoutingLocator() &&
-                     !messageInfo.GetPeerAddr().IsRoutingLocator(),
+                     !messageInfo.GetPeerAddr().IsRoutingLocator() &&
+                     !messageInfo.GetSockAddr().IsAnycastRoutingLocator() &&
+                     !messageInfo.GetPeerAddr().IsAnycastRoutingLocator(),
                      error = kThreadError_NoRoute);
 
         switch (aIpProto)

src/core/net/ip6_address.cpp

@@ -114,13 +114,14 @@ bool Address::IsRealmLocalAllMplForwarders(void) const
 bool Address::IsRoutingLocator(void) const
 {
     return (mFields.m16[4] == HostSwap16(0x0000) && mFields.m16[5] == HostSwap16(0x00ff) &&
-            mFields.m16[6] == HostSwap16(0xfe00));
+            mFields.m16[6] == HostSwap16(0xfe00) && mFields.m8[14] < kAloc16Mask &&
+            (mFields.m8[14] & kRloc16ReservedBitMask) == 0);
 }
 
 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);
+            mFields.m16[6] == HostSwap16(0xfe00) && mFields.m8[14] == kAloc16Mask);
 }
 
 bool Address::IsSubnetRouterAnycast(void) const

src/core/net/ip6_address.hpp

@@ -56,6 +56,16 @@ OT_TOOL_PACKED_BEGIN
 class Address: public otIp6Address
 {
 public:
+    /**
+     * Masks
+     *
+     */
+    enum
+    {
+        kAloc16Mask                 = 0xfc, ///< The mask for Aloc16.
+        kRloc16ReservedBitMask      = 0x02, ///< The mask for the reserved bit of Rloc16.
+    };
+
     /**
      * Constants
      *

src/core/thread/mle.cpp

@@ -3202,12 +3202,14 @@ uint16_t Mle::GetNextHop(uint16_t aDestination) const
 
 bool Mle::IsRoutingLocator(const Ip6::Address &aAddress) const
 {
-    return memcmp(&mMeshLocal16, &aAddress, kRlocPrefixLength) == 0 && aAddress.mFields.m8[14] != kAloc16Mask;
+    return memcmp(&mMeshLocal16, &aAddress, kRlocPrefixLength) == 0 &&
+           aAddress.mFields.m8[14] < Ip6::Address::kAloc16Mask &&
+           (aAddress.mFields.m8[14] & Ip6::Address::kRloc16ReservedBitMask) == 0;
 }
 
 bool Mle::IsAnycastLocator(const Ip6::Address &aAddress) const
 {
-    return memcmp(&mMeshLocal16, &aAddress, kRlocPrefixLength) == 0 && aAddress.mFields.m8[14] == kAloc16Mask;
+    return memcmp(&mMeshLocal16, &aAddress, kRlocPrefixLength) == 0 && aAddress.mFields.m8[14] == Ip6::Address::kAloc16Mask;
 }
 
 Router *Mle::GetParent()

src/core/thread/mle.hpp

@@ -110,7 +110,6 @@ enum DeviceState
  */
 enum AlocAllocation
 {
-    kAloc16Mask                         = 0xfc,
     kAloc16Leader                       = 0xfc00,
     kAloc16DhcpAgentStart               = 0xfc01,
     kAloc16DhcpAgentEnd                 = 0xfc0f,