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>

1 files changed, 10 insertions, 4 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index bae36386e722..7453dfcdb439 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -188,7 +188,9 @@ static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
         return p;
 }
 
-static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
+static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
+                                           struct sk_buff *skb,
+                                           const void *daddr);
 
 static struct dst_ops ipv4_dst_ops = {
         .family =               AF_INET,
@@ -1088,7 +1090,9 @@ static int slow_chain_length(const struct rtable *head)
         return length >> FRACT_BITS;
 }
 
-static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
+static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
+                                           struct sk_buff *skb,
+                                           const void *daddr)
 {
         struct net_device *dev = dst->dev;
         const __be32 *pkey = daddr;
@@ -1098,6 +1102,8 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const vo
         rt = (const struct rtable *) dst;
         if (rt->rt_gateway)
                 pkey = (const __be32 *) &rt->rt_gateway;
+        else if (skb)
+                pkey = &ip_hdr(skb)->daddr;
 
         n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
         if (n)
@@ -1107,7 +1113,7 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const vo
 
 static int rt_bind_neighbour(struct rtable *rt)
 {
-        struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
+        struct neighbour *n = ipv4_neigh_lookup(&rt->dst, NULL, &rt->rt_gateway);
         if (IS_ERR(n))
                 return PTR_ERR(n);
         dst_set_neighbour(&rt->dst, n);
@@ -1388,7 +1394,7 @@ static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
 
         rt->rt_gateway = peer->redirect_learned.a4;
 
-        n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
+        n = ipv4_neigh_lookup(&rt->dst, NULL, &rt->rt_gateway);
         if (IS_ERR(n)) {
                 rt->rt_gateway = orig_gw;
                 return;