[NETFILTER]: add IPv6-capable TCPMSS target

[linux-2.6-omap-h63xx.git] / net / ipv4 / netfilter / ip_conntrack_proto_tcp.c

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 06e4e8a6dd9f88db85452c556d51058025db3dde..c34f48fe547875e5bb48f9552526dd257eb79cfb 100644 (file)
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -50,12 +50,9 @@ static DEFINE_RWLOCK(tcp_lock);
     If it's non-zero, we mark only out of window RST segments as INVALID. */
 int ip_ct_tcp_be_liberal __read_mostly = 0;
 
-/* When connection is picked up from the middle, how many packets are required
-   to pass in each direction when we assume we are in sync - if any side uses
-   window scaling, we lost the game. 
-   If it is set to zero, we disable picking up already established 
+/* If it is set to zero, we disable picking up already established
    connections. */
-int ip_ct_tcp_loose __read_mostly = 3;
+int ip_ct_tcp_loose __read_mostly = 1;
 
 /* Max number of the retransmitted packets without receiving an (acceptable) 
    ACK from the destination. If this number is reached, a shorter timer 
@@ -694,11 +691,10 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                before(sack, receiver->td_end + 1),
                after(ack, receiver->td_end - MAXACKWINDOW(sender)));
        
-       if (sender->loose || receiver->loose ||
-           (before(seq, sender->td_maxend + 1) &&
-            after(end, sender->td_end - receiver->td_maxwin - 1) &&
-            before(sack, receiver->td_end + 1) &&
-            after(ack, receiver->td_end - MAXACKWINDOW(sender)))) {
+       if (before(seq, sender->td_maxend + 1) &&
+           after(end, sender->td_end - receiver->td_maxwin - 1) &&
+           before(sack, receiver->td_end + 1) &&
+           after(ack, receiver->td_end - MAXACKWINDOW(sender))) {
                /*
                 * Take into account window scaling (RFC 1323).
                 */
@@ -743,15 +739,13 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                                state->retrans = 0;
                        }
                }
-               /*
-                * Close the window of disabled window tracking :-)
-                */
-               if (sender->loose)
-                       sender->loose--;
-               
                res = 1;
        } else {
-               if (LOG_INVALID(IPPROTO_TCP))
+               res = 0;
+               if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
+                   ip_ct_tcp_be_liberal)
+                       res = 1;
+               if (!res && LOG_INVALID(IPPROTO_TCP))
                        nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
                        "ip_ct_tcp: %s ",
                        before(seq, sender->td_maxend + 1) ?
@@ -762,8 +756,6 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                        : "ACK is over the upper bound (ACKed data not seen yet)"
                        : "SEQ is under the lower bound (already ACKed data retransmitted)"
                        : "SEQ is over the upper bound (over the window of the receiver)");
-
-               res = ip_ct_tcp_be_liberal;
        }
   
        DEBUGP("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
@@ -1105,8 +1097,6 @@ static int tcp_new(struct ip_conntrack *conntrack,
 
                tcp_options(skb, iph, th, &conntrack->proto.tcp.seen[0]);
                conntrack->proto.tcp.seen[1].flags = 0;
-               conntrack->proto.tcp.seen[0].loose = 
-               conntrack->proto.tcp.seen[1].loose = 0;
        } else if (ip_ct_tcp_loose == 0) {
                /* Don't try to pick up connections. */
                return 0;
@@ -1127,11 +1117,11 @@ static int tcp_new(struct ip_conntrack *conntrack,
                        conntrack->proto.tcp.seen[0].td_maxwin;
                conntrack->proto.tcp.seen[0].td_scale = 0;
 
-               /* We assume SACK. Should we assume window scaling too? */
+               /* We assume SACK and liberal window checking to handle
+                * window scaling */
                conntrack->proto.tcp.seen[0].flags =
-               conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM;
-               conntrack->proto.tcp.seen[0].loose = 
-               conntrack->proto.tcp.seen[1].loose = ip_ct_tcp_loose;
+               conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
+                                                    IP_CT_TCP_FLAG_BE_LIBERAL;
        }
     
        conntrack->proto.tcp.seen[1].td_end = 0;