From: Phil Sutter Date: Mon, 27 Jul 2015 22:53:26 +0000 (+0200) Subject: netfilter: SYNPROXY: fix sending window update to client X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3c16241c445303a90529565e7437e1f240acfef2;p=linux-beck.git netfilter: SYNPROXY: fix sending window update to client Upon receipt of SYNACK from the server, ipt_SYNPROXY first sends back an ACK to finish the server handshake, then calls nf_ct_seqadj_init() to initiate sequence number adjustment of forwarded packets to the client and finally sends a window update to the client to unblock it's TX queue. Since synproxy_send_client_ack() does not set synproxy_send_tcp()'s nfct parameter, no sequence number adjustment happens and the client receives the window update with incorrect sequence number. Depending on client TCP implementation, this leads to a significant delay (until a window probe is being sent). Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/ipv4/netfilter/ipt_SYNPROXY.c b/net/ipv4/netfilter/ipt_SYNPROXY.c index fe8cc183411e..95ea633e8356 100644 --- a/net/ipv4/netfilter/ipt_SYNPROXY.c +++ b/net/ipv4/netfilter/ipt_SYNPROXY.c @@ -226,7 +226,8 @@ synproxy_send_client_ack(const struct synproxy_net *snet, synproxy_build_options(nth, opts); - synproxy_send_tcp(skb, nskb, NULL, 0, niph, nth, tcp_hdr_size); + synproxy_send_tcp(skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY, + niph, nth, tcp_hdr_size); } static bool diff --git a/net/ipv6/netfilter/ip6t_SYNPROXY.c b/net/ipv6/netfilter/ip6t_SYNPROXY.c index bcebc24c6f0b..ebbb754c2111 100644 --- a/net/ipv6/netfilter/ip6t_SYNPROXY.c +++ b/net/ipv6/netfilter/ip6t_SYNPROXY.c @@ -243,7 +243,8 @@ synproxy_send_client_ack(const struct synproxy_net *snet, synproxy_build_options(nth, opts); - synproxy_send_tcp(snet, skb, nskb, NULL, 0, niph, nth, tcp_hdr_size); + synproxy_send_tcp(snet, skb, nskb, skb->nfct, IP_CT_ESTABLISHED_REPLY, + niph, nth, tcp_hdr_size); } static bool