From: Dmitry Popov Date: Fri, 4 Jul 2014 22:26:37 +0000 (+0400) Subject: ip_tunnel: fix ip_tunnel_lookup X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e0056593b61253f1a8a9941dacda22e73b963cdc;p=openwrt%2Fstaging%2Fblogic.git ip_tunnel: fix ip_tunnel_lookup This patch fixes 3 similar bugs where incoming packets might be routed into wrong non-wildcard tunnels: 1) Consider the following setup: ip address add 1.1.1.1/24 dev eth0 ip address add 1.1.1.2/24 dev eth0 ip tunnel add ipip1 remote 2.2.2.2 local 1.1.1.1 mode ipip dev eth0 ip link set ipip1 up Incoming ipip packets from 2.2.2.2 were routed into ipip1 even if it has dst = 1.1.1.2. Moreover even if there was wildcard tunnel like ip tunnel add ipip0 remote 2.2.2.2 local any mode ipip dev eth0 but it was created before explicit one (with local 1.1.1.1), incoming ipip packets with src = 2.2.2.2 and dst = 1.1.1.2 were still routed into ipip1. Same issue existed with all tunnels that use ip_tunnel_lookup (gre, vti) 2) ip address add 1.1.1.1/24 dev eth0 ip tunnel add ipip1 remote 2.2.146.85 local 1.1.1.1 mode ipip dev eth0 ip link set ipip1 up Incoming ipip packets with dst = 1.1.1.1 were routed into ipip1, no matter what src address is. Any remote ip address which has ip_tunnel_hash = 0 raised this issue, 2.2.146.85 is just an example, there are more than 4 million of them. And again, wildcard tunnel like ip tunnel add ipip0 remote any local 1.1.1.1 mode ipip dev eth0 wouldn't be ever matched if it was created before explicit tunnel like above. Gre & vti tunnels had the same issue. 3) ip address add 1.1.1.1/24 dev eth0 ip tunnel add gre1 remote 2.2.146.84 local 1.1.1.1 key 1 mode gre dev eth0 ip link set gre1 up Any incoming gre packet with key = 1 were routed into gre1, no matter what src/dst addresses are. Any remote ip address which has ip_tunnel_hash = 0 raised the issue, 2.2.146.84 is just an example, there are more than 4 million of them. Wildcard tunnel like ip tunnel add gre2 remote any local any key 1 mode gre dev eth0 wouldn't be ever matched if it was created before explicit tunnel like above. All this stuff happened because while looking for a wildcard tunnel we didn't check that matched tunnel is a wildcard one. Fixed. Signed-off-by: Dmitry Popov Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 54b6731dab55..6f9de61dce5f 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -169,6 +169,7 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, hlist_for_each_entry_rcu(t, head, hash_node) { if (remote != t->parms.iph.daddr || + t->parms.iph.saddr != 0 || !(t->dev->flags & IFF_UP)) continue; @@ -185,10 +186,11 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, head = &itn->tunnels[hash]; hlist_for_each_entry_rcu(t, head, hash_node) { - if ((local != t->parms.iph.saddr && - (local != t->parms.iph.daddr || - !ipv4_is_multicast(local))) || - !(t->dev->flags & IFF_UP)) + if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) && + (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) + continue; + + if (!(t->dev->flags & IFF_UP)) continue; if (!ip_tunnel_key_match(&t->parms, flags, key)) @@ -205,6 +207,8 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, hlist_for_each_entry_rcu(t, head, hash_node) { if (t->parms.i_key != key || + t->parms.iph.saddr != 0 || + t->parms.iph.daddr != 0 || !(t->dev->flags & IFF_UP)) continue;