[ 23/89] netfilter: nf_nat: dont check for port change on ICMP tuples

From: Ben Hutchings
Date: Mon Dec 03 2012 - 09:38:23 EST


3.2-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.

Signed-off-by: Ulrich Weber <ulrich.weber@xxxxxxxxxx>
[Pablo Neira Ayuso: Backported to.3.0]
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
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 483b76d..b2c3ed7 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;


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