net/netfilter/nf_conntrack_proto_tcp.c

110  * equivalent with the ones of the sender/receiver. We always
128  *	and the receiver may send back a connection
302    II.  Lower bound for valid data:	seq + len >= sender.td_end - receiver.td_maxwin
303    III.	Upper bound for valid (s)ack:   sack <= receiver.td_end
304    IV.	Lower bound for valid (s)ack:	sack >= receiver.td_end - MAXACKWINDOW
456 			    struct ip_ct_tcp_state *receiver,
477 	      receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE)) {
479 		receiver->td_scale = 0;
517 	struct ip_ct_tcp_state *receiver = &state->seen[!dir];
532 	if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
545 			tcp_init_sender(sender, receiver,
561 			if (receiver->td_maxwin == 0) {
567 				receiver->td_end = receiver->td_maxend = sack;
568 			} else if (sack == receiver->td_end + 1) {
572 				receiver->td_end++;
588 		tcp_init_sender(sender, receiver,
600 		ack = sack = receiver->td_end;
608 		ack = sack = receiver->td_end;
622 		ack_ok = after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1);
623 		in_recv_win = receiver->td_maxwin &&
624 			      after(end, sender->td_end - receiver->td_maxwin - 1);
628 		    overshot <= receiver->td_maxwin &&
629 		    before(sack, receiver->td_end + 1)) {
648 					  "SEQ is over upper bound %u (over the window of the receiver)",
652 	if (!before(sack, receiver->td_end + 1))
655 					  receiver->td_end + 1);
658 	in_recv_win = !receiver->td_maxwin ||
659 		      after(end, sender->td_end - receiver->td_maxwin - 1);
663 					  sender->td_end - receiver->td_maxwin - 1);
664 	if (!after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1))
667 					  receiver->td_end - MAXACKWINDOW(sender) - 1);
690 	/* Update receiver data. */
691 	if (receiver->td_maxwin != 0 && after(end, sender->td_maxend))
692 		receiver->td_maxwin += end - sender->td_maxend;
693 	if (after(sack + win, receiver->td_maxend - 1)) {
694 		receiver->td_maxend = sack + win;
696 			receiver->td_maxend++;
698 	if (ack == receiver->td_end)
699 		receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
1040 		 * If the ignored packet is invalid, the receiver will send