netfilter: xt_connlimit: fix accouning when receive RST packet in ESTABLISHED state

upstream commit: d2ee3f2c4b1db1320c1efb4dcaceeaf6c7e6c2d3

In xt_connlimit match module, the counter of an IP is decreased when
the TCP packet is go through the chain with ip_conntrack state TW.
Well, it's very natural that the server and client close the socket
with FIN packet. But when the client/server close the socket with RST
packet(using so_linger), the counter for this connection still exsit.
The following patch can fix it which is based on linux-2.6.25.4

Signed-off-by: Dong Wei <dwei.zh@gmail.com>
Acked-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 3b0111933f601782887e4edc8f7500aff4a2116f..16923386753732606fce43856e2a41ba4ed8808b 100644 (file)
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -75,7 +75,8 @@ static inline bool already_closed(const struct nf_conn *conn)
        u_int16_t proto = conn->tuplehash[0].tuple.dst.protonum;
 
        if (proto == IPPROTO_TCP)
-               return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT;
+               return conn->proto.tcp.state == TCP_CONNTRACK_TIME_WAIT ||
+                      conn->proto.tcp.state == TCP_CONNTRACK_CLOSE;
        else
                return 0;
 }