[NETFILTER]: nf_conntrack_tcp: fix connection reopening fix

If one side aborts an established connection, the entry still lingers
for 10s in conntrack for the late packets. Allow to open up the
connection again for the party which sent the RST packet.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/nf_conntrack_proto_tcp.c

@@ -834,10 +834,12 @@ static int tcp_packet(struct nf_conn *conntrack,
 	case TCP_CONNTRACK_SYN_SENT:
 		if (old_state < TCP_CONNTRACK_TIME_WAIT)
 			break;
-		if (conntrack->proto.tcp.seen[!dir].flags &
-			IP_CT_TCP_FLAG_CLOSE_INIT) {
-			/* Attempt to reopen a closed connection.
-			* Delete this connection and look up again. */
+		if ((conntrack->proto.tcp.seen[!dir].flags &
+			IP_CT_TCP_FLAG_CLOSE_INIT)
+		    || (conntrack->proto.tcp.last_dir == dir
+		        && conntrack->proto.tcp.last_index == TCP_RST_SET)) {
+			/* Attempt to reopen a closed/aborted connection.
+			 * Delete this connection and look up again. */
 			write_unlock_bh(&tcp_lock);
 			if (del_timer(&conntrack->timeout))
 				conntrack->timeout.function((unsigned long)
@@ -925,6 +927,7 @@ static int tcp_packet(struct nf_conn *conntrack,
      in_window:
 	/* From now on we have got in-window packets */
 	conntrack->proto.tcp.last_index = index;
+	conntrack->proto.tcp.last_dir = dir;
 
 	pr_debug("tcp_conntracks: ");
 	NF_CT_DUMP_TUPLE(tuple);