| Message ID | alpine.LFD.2.00.1106080926320.1457@ja.ssi.bg |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On 08.06.2011 08:31, Julian Anastasov wrote: > Avoid double seq adjustment for loopback traffic > because it causes silent repetition of TCP data. One > example is passive FTP with DNAT rule and difference in the > length of IP addresses. > > This patch adds check if packet is sent and > received via loopback device. As the same conntrack is > used both for outgoing and incoming direction, we restrict > seq adjustment to happen only in POSTROUTING. > > Signed-off-by: Julian Anastasov <ja@ssi.bg> Applied, thanks Julian. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff -urp v2.6.39/linux/include/net/netfilter/nf_conntrack.h linux/include/net/netfilter/nf_conntrack.h --- v2.6.39/linux/include/net/netfilter/nf_conntrack.h 2011-05-20 10:38:04.000000000 +0300 +++ linux/include/net/netfilter/nf_conntrack.h 2011-06-08 08:29:58.880272586 +0300 @@ -308,6 +308,12 @@ static inline int nf_ct_is_untracked(con return test_bit(IPS_UNTRACKED_BIT, &ct->status); } +/* Packet is received from loopback */ +static inline bool nf_is_loopback_packet(const struct sk_buff *skb) +{ + return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK; +} + extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp); extern unsigned int nf_conntrack_htable_size; extern unsigned int nf_conntrack_max; diff -urp v2.6.39/linux/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c linux/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c --- v2.6.39/linux/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c 2010-08-02 09:37:49.000000000 +0300 +++ linux/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c 2011-06-08 08:34:15.594269592 +0300 @@ -121,7 +121,9 @@ static unsigned int ipv4_confirm(unsigne return ret; } - if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) { + /* adjust seqs for loopback traffic only in outgoing direction */ + if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && + !nf_is_loopback_packet(skb)) { typeof(nf_nat_seq_adjust_hook) seq_adjust; seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
Avoid double seq adjustment for loopback traffic because it causes silent repetition of TCP data. One example is passive FTP with DNAT rule and difference in the length of IP addresses. This patch adds check if packet is sent and received via loopback device. As the same conntrack is used both for outgoing and incoming direction, we restrict seq adjustment to happen only in POSTROUTING. Signed-off-by: Julian Anastasov <ja@ssi.bg> --- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html