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

From: Herton Ronaldo Krzesinski
Date: Thu Dec 13 2012 - 09:22:15 EST


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

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

From: Ulrich Weber <ulrich.weber@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/