gre: Don't accidentally set RTO_ONLINK in gre_fill_metadata_dst()

Mask the ECN bits before initialising ->flowi4_tos. The tunnel key may
have the last ECN bit set, which will interfere with the route lookup
process as ip_route_output_key_hash() interpretes this bit specially
(to restrict the route scope).

Found by code inspection, compile tested only.

Fixes: 962924fa2b ("ip_gre: Refactor collect metatdata mode tunnel xmit to ip_md_tunnel_xmit")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Guillaume Nault 2022-01-10 14:43:09 +01:00 committed by Jakub Kicinski
parent 23e7b1bfed
commit f7716b3185
1 changed files with 3 additions and 2 deletions

View File

@ -604,8 +604,9 @@ static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
key = &info->key;
ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
tunnel_id_to_key32(key->tun_id), key->tos, 0,
skb->mark, skb_get_hash(skb));
tunnel_id_to_key32(key->tun_id),
key->tos & ~INET_ECN_MASK, 0, skb->mark,
skb_get_hash(skb));
rt = ip_route_output_key(dev_net(dev), &fl4);
if (IS_ERR(rt))
return PTR_ERR(rt);