add 'src-lookup' keyword for FIB paths

Change-Id: I4554d1e94bd70ef5b3b0aaeb1a0fceaeb81c5f96
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/fib/fib_types.c b/src/vnet/fib/fib_types.c
index 035f700..1046e45 100644
--- a/src/vnet/fib/fib_types.c
+++ b/src/vnet/fib/fib_types.c
@@ -495,6 +495,10 @@
             rpath->frp_proto = DPO_PROTO_MPLS;
             *payload_proto = DPO_PROTO_MPLS;
         }
+        else if (unformat (input, "src-lookup"))
+        {
+            rpath->frp_flags |= FIB_ROUTE_PATH_SOURCE_LOOKUP;
+        }
         else if (unformat (input,
                            "l2-input-on %U",
                            unformat_vnet_sw_interface, vnm,