Remove Netif name and rely on enumerated Interface Id's for netif. (#833)

* Remove Netif name and rely on enumerated Interface Id's for netif.

src/core/net/ip6.cpp

@@ -58,8 +58,7 @@ Ip6::Ip6(void):
     mReceiveIp6DatagramCallback(NULL),
     mReceiveIp6DatagramCallbackContext(NULL),
     mIsReceiveIp6FilterEnabled(false),
-    mNetifListHead(NULL),
-    mNextInterfaceId(1)
+    mNetifListHead(NULL)
 {
 }
 
@@ -609,7 +608,7 @@ ThreadError Ip6::AddNetif(Netif &aNetif)
 
         do
         {
-            if (netif == &aNetif)
+            if (netif == &aNetif || netif->mInterfaceId == aNetif.mInterfaceId)
             {
                 ExitNow(error = kThreadError_Already);
             }
@@ -621,11 +620,6 @@ ThreadError Ip6::AddNetif(Netif &aNetif)
 
     aNetif.mNext = NULL;
 
-    if (aNetif.mInterfaceId < 0)
-    {
-        aNetif.mInterfaceId = mNextInterfaceId++;
-    }
-
 exit:
     return error;
 }
@@ -682,22 +676,6 @@ exit:
     return netif;
 }
 
-Netif *Ip6::GetNetifByName(char *aName)
-{
-    Netif *netif;
-
-    for (netif = mNetifListHead; netif; netif = netif->mNext)
-    {
-        if (strcmp(netif->GetName(), aName) == 0)
-        {
-            ExitNow();
-        }
-    }
-
-exit:
-    return netif;
-}
-
 bool Ip6::IsUnicastAddress(const Address &aAddress)
 {
     bool rval = false;