net: Add optional SKB arg to dst_ops->neigh_lookup().

Causes the handler to use the daddr in the ipv4/ipv6 header when
the route gateway is unspecified (local subnet).

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst.h b/include/net/dst.h
index 84e7a3f..295a705 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -420,7 +420,13 @@
 
 static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
 {
-	return dst->ops->neigh_lookup(dst, daddr);
+	return dst->ops->neigh_lookup(dst, NULL, daddr);
+}
+
+static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
+						     struct sk_buff *skb)
+{
+	return dst->ops->neigh_lookup(dst, skb, NULL);
 }
 
 static inline void dst_link_failure(struct sk_buff *skb)