[PATCH nf-next] netfilter: nf_flowtable: skip device lookup from interface index

[Pablo Neira Ayuso]

Use the output device from the route that we cache in the flowtable
entry.

Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nf_flow_table_ip.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 1d291a51cd45..6452550d187f 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -235,13 +235,10 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
        if (tuplehash == NULL)
                return NF_ACCEPT;
 
-       outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx);
-       if (!outdev)
-               return NF_ACCEPT;
-
        dir = tuplehash->tuple.dir;
        flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
        rt = (struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
+       outdev = rt->dst.dev;
 
        if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)) 
&&
            (ip_hdr(skb)->frag_off & htons(IP_DF)) != 0)
@@ -452,13 +449,10 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
        if (tuplehash == NULL)
                return NF_ACCEPT;
 
-       outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx);
-       if (!outdev)
-               return NF_ACCEPT;
-
        dir = tuplehash->tuple.dir;
        flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
        rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
+       outdev = rt->dst.dev;
 
        if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
                return NF_ACCEPT;
-- 
2.11.0