| Message ID | 1400218479-10166-1-git-send-email-timo.teras@iki.fi |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Timo Teräs <timo.teras@iki.fi> Date: Fri, 16 May 2014 08:34:39 +0300 > The connected check fails to check for ip_gre nbma mode tunnels > properly. ip_gre creates temporary tnl_params with daddr specified > to pass-in the actual target on per-packet basis from neighbor > layer. Detect these tunnels by inspecting the actual tunnel > configuration. > > Minimal test case: > ip route add 192.168.1.1/32 via 10.0.0.1 > ip route add 192.168.1.2/32 via 10.0.0.2 > ip tunnel add nbma0 mode gre key 1 tos c0 > ip addr add 172.17.0.0/16 dev nbma0 > ip link set nbma0 up > ip neigh add 172.17.0.1 lladdr 192.168.1.1 dev nbma0 > ip neigh add 172.17.0.2 lladdr 192.168.1.2 dev nbma0 > ping 172.17.0.1 > ping 172.17.0.2 > > The second ping should be going to 192.168.1.2 and head 10.0.0.2; > but cached gre tunnel level route is used and it's actually going > to 192.168.1.1 via 10.0.0.1. > > The lladdr's need to go to separate dst for the bug to trigger. > Test case uses separate route entries, but this can also happen > when the route entry is same: if there is a nexthop exception or > the GRE tunnel is IPsec'ed in which case the dst points to xfrm > bundle unique to the gre lladdr. > > Fixes: 7d442fab0a67 ("ipv4: Cache dst in tunnels") > Signed-off-by: Timo Teräs <timo.teras@iki.fi> Yeah, this one compiles :-) Applied and queued up for -stable, thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index e77381d..4eb9196 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -538,9 +538,10 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, unsigned int max_headroom; /* The extra header space needed */ __be32 dst; int err; - bool connected = true; + bool connected; inner_iph = (const struct iphdr *)skb_inner_network_header(skb); + connected = (tunnel->parms.iph.daddr != 0); dst = tnl_params->daddr; if (dst == 0) {
The connected check fails to check for ip_gre nbma mode tunnels properly. ip_gre creates temporary tnl_params with daddr specified to pass-in the actual target on per-packet basis from neighbor layer. Detect these tunnels by inspecting the actual tunnel configuration. Minimal test case: ip route add 192.168.1.1/32 via 10.0.0.1 ip route add 192.168.1.2/32 via 10.0.0.2 ip tunnel add nbma0 mode gre key 1 tos c0 ip addr add 172.17.0.0/16 dev nbma0 ip link set nbma0 up ip neigh add 172.17.0.1 lladdr 192.168.1.1 dev nbma0 ip neigh add 172.17.0.2 lladdr 192.168.1.2 dev nbma0 ping 172.17.0.1 ping 172.17.0.2 The second ping should be going to 192.168.1.2 and head 10.0.0.2; but cached gre tunnel level route is used and it's actually going to 192.168.1.1 via 10.0.0.1. The lladdr's need to go to separate dst for the bug to trigger. Test case uses separate route entries, but this can also happen when the route entry is same: if there is a nexthop exception or the GRE tunnel is IPsec'ed in which case the dst points to xfrm bundle unique to the gre lladdr. Fixes: 7d442fab0a67 ("ipv4: Cache dst in tunnels") Signed-off-by: Timo Teräs <timo.teras@iki.fi> Cc: Tom Herbert <therbert@google.com> Cc: Eric Dumazet <edumazet@google.com> --- Should go to 3.14-stable too. net/ipv4/ip_tunnel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)