ipv4: Make sure flowi4->{saddr,daddr} are always set.

Slow path output route resolution always makes sure that
->{saddr,daddr} are set, and also if we trigger into IPSEC resolution
we initialize them as well, because xfrm_lookup() expects them to be
fully resolved.

But if we hit the fast path and flowi4->flowi4_proto is zero, we won't
do this initialization.

Therefore, move the IPSEC path initialization to the route cache
lookup fast path to make sure these are always set.

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

1 files changed, 5 insertions, 6 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 93f71be1d5d1..64f360d853fb 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2675,6 +2675,10 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
                         dst_use(&rth->dst, jiffies);
                         RT_CACHE_STAT_INC(out_hit);
                         rcu_read_unlock_bh();
+                        if (!flp4->saddr)
+                                flp4->saddr = rth->rt_src;
+                        if (!flp4->daddr)
+                                flp4->daddr = rth->rt_dst;
                         return rth;
                 }
                 RT_CACHE_STAT_INC(out_hlist_search);
@@ -2772,15 +2776,10 @@ struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
         if (IS_ERR(rt))
                 return rt;
 
-        if (flp4->flowi4_proto) {
-                if (!flp4->saddr)
-                        flp4->saddr = rt->rt_src;
-                if (!flp4->daddr)
-                        flp4->daddr = rt->rt_dst;
+        if (flp4->flowi4_proto)
                 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
                                                    flowi4_to_flowi(flp4),
                                                    sk, 0);
-        }
 
         return rt;
 }