[PATCH 211/241] netfilter: nf_nat: don't check for port change on ICMP tuples

[Herton Ronaldo Krzesinski]

3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ulrich Weber <ulrich.weber at sophos.com>

commit 38fe36a248ec3228f8e6507955d7ceb0432d2000 upstream.

ICMP tuples have id in src and type/code in dst.
So comparing src.u.all with dst.u.all will always fail here
and ip_xfrm_me_harder() is called for every ICMP packet,
even if there was no NAT.

This patch is a backport of:

[ 38fe36a netfilter: nf_nat: don't check for port change on ICMP tuples ]

Signed-off-by: Ulrich Weber <ulrich.weber at sophos.com>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 net/ipv4/netfilter/nf_nat_standalone.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c
index 3828a42..da4098f 100644
--- a/net/ipv4/netfilter/nf_nat_standalone.c
+++ b/net/ipv4/netfilter/nf_nat_standalone.c
@@ -194,7 +194,8 @@ nf_nat_out(unsigned int hooknum,
 
 		if ((ct->tuplehash[dir].tuple.src.u3.ip !=
 		     ct->tuplehash[!dir].tuple.dst.u3.ip) ||
-		    (ct->tuplehash[dir].tuple.src.u.all !=
+		    (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP &&
+		     ct->tuplehash[dir].tuple.src.u.all !=
 		     ct->tuplehash[!dir].tuple.dst.u.all)
 		   )
 			return ip_xfrm_me_harder(skb) == 0 ? ret : NF_DROP;
@@ -230,7 +231,8 @@ nf_nat_local_fn(unsigned int hooknum,
 				ret = NF_DROP;
 		}
 #ifdef CONFIG_XFRM
-		else if (ct->tuplehash[dir].tuple.dst.u.all !=
+		else if (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP &&
+			 ct->tuplehash[dir].tuple.dst.u.all !=
 			 ct->tuplehash[!dir].tuple.src.u.all)
 			if (ip_xfrm_me_harder(skb))
 				ret = NF_DROP;
-- 
1.7.9.5