ipv4: Make neigh lookups directly in output packet path.

Do not use the dst cached neigh, we'll be getting rid of that.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 2630900e480a..6e9a266a0535 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -170,6 +170,7 @@ static inline int ip_finish_output2(struct sk_buff *skb)
         struct net_device *dev = dst->dev;
         unsigned int hh_len = LL_RESERVED_SPACE(dev);
         struct neighbour *neigh;
+        u32 nexthop;
 
         if (rt->rt_type == RTN_MULTICAST) {
                 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len);
@@ -191,15 +192,18 @@ static inline int ip_finish_output2(struct sk_buff *skb)
                 skb = skb2;
         }
 
-        rcu_read_lock();
-        neigh = dst_get_neighbour_noref(dst);
+        rcu_read_lock_bh();
+        nexthop = rt->rt_gateway ? rt->rt_gateway : ip_hdr(skb)->daddr;
+        neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
+        if (unlikely(!neigh))
+                neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
         if (neigh) {
                 int res = neigh_output(neigh, skb);
 
-                rcu_read_unlock();
+                rcu_read_unlock_bh();
                 return res;
         }
-        rcu_read_unlock();
+        rcu_read_unlock_bh();
 
         net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
                             __func__);