sys/netinet/tcp_sack.c

450 	struct sackhole *hole;
458 	hole = (struct sackhole *)uma_zalloc(V_sack_hole_zone, M_NOWAIT);
459 	if (hole == NULL)
462 	hole->start = start;
463 	hole->end = end;
464 	hole->rxmit = start;
469 	return hole;
476 tcp_sackhole_free(struct tcpcb *tp, struct sackhole *hole)
479 	uma_zfree(V_sack_hole_zone, hole);
489  * Insert new SACK hole into scoreboard.
495 	struct sackhole *hole;
497 	/* Allocate a new SACK hole. */
498 	hole = tcp_sackhole_alloc(tp, start, end);
499 	if (hole == NULL)
502 	/* Insert the new SACK hole into scoreboard. */
504 		TAILQ_INSERT_AFTER(&tp->snd_holes, after, hole, scblink);
506 		TAILQ_INSERT_TAIL(&tp->snd_holes, hole, scblink);
510 		tp->sackhint.nexthole = hole;
512 	return hole;
516  * Remove SACK hole from scoreboard.
519 tcp_sackhole_remove(struct tcpcb *tp, struct sackhole *hole)
523 	if (tp->sackhint.nexthole == hole)
524 		tp->sackhint.nexthole = TAILQ_NEXT(hole, scblink);
526 	/* Remove this SACK hole. */
527 	TAILQ_REMOVE(&tp->snd_holes, hole, scblink);
529 	/* Free this SACK hole. */
530 	tcp_sackhole_free(tp, hole);
631 		 * hole at the tail.  If the second or later highest SACK
633 		 * inserted by way of hole splitting in the while-loop below.
643 			 * We failed to add a new hole based on the current
662 	cur = TAILQ_LAST(&tp->snd_holes, sackhole_head); /* Last SACK hole. */
670 			 * SACKs data beyond the current hole.  Go to the
678 			 * SACKs data before the current hole.  Go to the
679 			 * previous hole.
689 			/* Data acks at least the beginning of hole. */
691 				/* Acks entire hole, so delete hole. */
697 				 * next hole too, so continue onto the next
698 				 * hole.
702 				/* Move start of hole forward. */
707 			/* Data acks at least the end of hole. */
709 				/* Move end of hole backward. */
714 				 * ACKs some data in middle of a hole; need
715 				 * to split current hole
735 		 * we're done with the sack block or the sack hole.
805 			if (SEQ_LT(p->rxmit, tp->snd_una)) {/* old SACK hole */
818  * Returns the next hole to retransmit and the number of retransmitted bytes
819  * from the scoreboard.  We store both the next hole and the number of
824  * the loop to traverse more than 1 link before finding the next hole to
831  * that hole has been sacked, in which case, the hole would have been removed
837 	struct sackhole *hole = NULL;
841 	hole = tp->sackhint.nexthole;
842 	if (hole == NULL || SEQ_LT(hole->rxmit, hole->end))
844 	while ((hole = TAILQ_NEXT(hole, scblink)) != NULL) {
845 		if (SEQ_LT(hole->rxmit, hole->end)) {
846 			tp->sackhint.nexthole = hole;
851 	return (hole);
871 	 * i) snd_nxt lies between end of one hole and beginning of another
872 	 * ii) snd_nxt lies between end of last hole and snd_fack