L2 over MPLS

[support for VPWS/VPLS]
- switch to using dpo_proto_t rather than fib_protocol_t in fib_paths so that we can describe L2 paths
- VLIB nodes to handle pop/push of MPLS labels to L2

Change-Id: Id050d06a11fd2c9c1c81ce5a0654e6c5ae6afa6e
Signed-off-by: Neale Ranns <nranns@cisco.com>

src/vnet/fib/fib_path_ext.c

@@ -191,6 +191,9 @@ fib_path_ext_stack (fib_path_ext_t *path_ext,
     case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
         parent_fct = child_fct;
 	break;
+    case FIB_FORW_CHAIN_TYPE_ETHERNET:
+        parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS;
+	break;
     default:
         return (nhs);
 	break;