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authorPatrick McHardy <kaber@trash.net>2009-06-29 14:07:56 +0200
committerPatrick McHardy <kaber@trash.net>2009-06-29 14:07:56 +0200
commita3a9f79e361e864f0e9d75ebe2a0cb43d17c4272 (patch)
treee38bb7cc051cf197a813d553713e3071d375a1b9 /net/netfilter
parent308ff823ebd749a94d3b6ac26b95bc0eb114c39e (diff)
downloadlinux-a3a9f79e361e864f0e9d75ebe2a0cb43d17c4272.tar.bz2
netfilter: tcp conntrack: fix unacknowledged data detection with NAT
When NAT helpers change the TCP packet size, the highest seen sequence number needs to be corrected. This is currently only done upwards, when the packet size is reduced the sequence number is unchanged. This causes TCP conntrack to falsely detect unacknowledged data and decrease the timeout. Fix by updating the highest seen sequence number in both directions after packet mangling. Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_conntrack_proto_tcp.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 33fc0a443f3d..97a82ba75376 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -720,8 +720,8 @@ static bool tcp_in_window(const struct nf_conn *ct,
/* Caller must linearize skb at tcp header. */
void nf_conntrack_tcp_update(const struct sk_buff *skb,
unsigned int dataoff,
- struct nf_conn *ct,
- int dir)
+ struct nf_conn *ct, int dir,
+ s16 offset)
{
const struct tcphdr *tcph = (const void *)skb->data + dataoff;
const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[dir];
@@ -734,7 +734,7 @@ void nf_conntrack_tcp_update(const struct sk_buff *skb,
/*
* We have to worry for the ack in the reply packet only...
*/
- if (after(end, ct->proto.tcp.seen[dir].td_end))
+ if (ct->proto.tcp.seen[dir].td_end + offset == end)
ct->proto.tcp.seen[dir].td_end = end;
ct->proto.tcp.last_end = end;
spin_unlock_bh(&ct->lock);