Merge branch 'topic/ctxfi' into for-linus

[pandora-kernel.git] / net / netfilter / nf_conntrack_proto_tcp.c

diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index b5ccf2b..97a6e93 100644 (file)
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -634,6 +634,14 @@ static bool tcp_in_window(const struct nf_conn *ct,
                        sender->td_end = end;
                        sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
                }
+               if (tcph->ack) {
+                       if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) {
+                               sender->td_maxack = ack;
+                               sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET;
+                       } else if (after(ack, sender->td_maxack))
+                               sender->td_maxack = ack;
+               }
+
                /*
                 * Update receiver data.
                 */
@@ -918,6 +926,16 @@ static int tcp_packet(struct nf_conn *ct,
                                  "nf_ct_tcp: invalid state ");
                return -NF_ACCEPT;
        case TCP_CONNTRACK_CLOSE:
+               if (index == TCP_RST_SET
+                   && (ct->proto.tcp.seen[!dir].flags & IP_CT_TCP_FLAG_MAXACK_SET)
+                   && before(ntohl(th->seq), ct->proto.tcp.seen[!dir].td_maxack)) {
+                       /* Invalid RST  */
+                       write_unlock_bh(&tcp_lock);
+                       if (LOG_INVALID(net, IPPROTO_TCP))
+                               nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
+                                         "nf_ct_tcp: invalid RST ");
+                       return -NF_ACCEPT;
+               }
                if (index == TCP_RST_SET
                    && ((test_bit(IPS_SEEN_REPLY_BIT, &ct->status)
                         && ct->proto.tcp.last_index == TCP_SYN_SET)