sit: Fix ipip6_tunnel_lookup device matching criteria

[ Upstream commit bc8fc7b8f825ef17a0fb9e68c18ce94fa66ab337 ]

As of 4fddbf5d78 ("sit: strictly restrict incoming traffic to tunnel link device"),
when looking up a tunnel, tunnel's underlying interface (t->parms.link)
is verified to match incoming traffic's ingress device.

However the comparison was incorrectly based on skb->dev->iflink.

Instead, dev->ifindex should be used, which correctly represents the
interface from which the IP stack hands the ipip6 packets.

This allows setting up sit tunnels bound to vlan interfaces (otherwise
incoming ipip6 traffic on the vlan interface was dropped due to
ipip6_tunnel_lookup match failure).

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 8d22460a811ba1254cfd3655cdce73456a00efb9..4ddf67c6355bc1662016caba331b785d7cb8e3b4 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -101,19 +101,19 @@ static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
        for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
                if (local == t->parms.iph.saddr &&
                    remote == t->parms.iph.daddr &&
-                   (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
+                   (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
                    (t->dev->flags & IFF_UP))
                        return t;
        }
        for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
                if (remote == t->parms.iph.daddr &&
-                   (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
+                   (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
                    (t->dev->flags & IFF_UP))
                        return t;
        }
        for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
                if (local == t->parms.iph.saddr &&
-                   (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
+                   (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
                    (t->dev->flags & IFF_UP))
                        return t;
        }