[NETFILTER]: TCP conntrack: improve dead connection detection

Don't count window updates as retransmissions.

Signed-off-by: George Hansper <georgeh@anstat.com.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_tcp.h b/include/linux/netfilter/nf_conntrack_tcp.h
index b2feeff..6b01ba2 100644 (file)
--- a/include/linux/netfilter/nf_conntrack_tcp.h
+++ b/include/linux/netfilter/nf_conntrack_tcp.h
@@ -49,6 +49,7 @@ struct ip_ct_tcp
        u_int32_t       last_seq;       /* Last sequence number seen in dir */
        u_int32_t       last_ack;       /* Last sequence number seen in opposite dir */
        u_int32_t       last_end;       /* Last seq + len */
+       u_int16_t       last_win;       /* Last window advertisement seen in dir */
 };
 
 #endif /* __KERNEL__ */

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 75a7237..03ae9a0 100644 (file)
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -731,13 +731,15 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                        if (state->last_dir == dir
                            && state->last_seq == seq
                            && state->last_ack == ack
-                           && state->last_end == end)
+                           && state->last_end == end
+                           && state->last_win == win)
                                state->retrans++;
                        else {
                                state->last_dir = dir;
                                state->last_seq = seq;
                                state->last_ack = ack;
                                state->last_end = end;
+                               state->last_win = win;
                                state->retrans = 0;
                        }
                }

diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 9fc0ee6..238bbb5 100644 (file)
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -688,13 +688,15 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                        if (state->last_dir == dir
                            && state->last_seq == seq
                            && state->last_ack == ack
-                           && state->last_end == end)
+                           && state->last_end == end
+                           && state->last_win == win)
                                state->retrans++;
                        else {
                                state->last_dir = dir;
                                state->last_seq = seq;
                                state->last_ack = ack;
                                state->last_end = end;
+                               state->last_win = win;
                                state->retrans = 0;
                        }
                }