This is conform with the terminology in
M.Mathis and J.Mahdavi, "Forward Acknowledgement: Refining TCP Congestion Control" SIGCOMM'96, August 1996. Submitted by: Noritoshi Demizu, Raja Mukerji
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cf27ba88ea
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808f11b768
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=146630
@ -1840,9 +1840,8 @@ tcp_input(m, off0)
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else if (++tp->t_dupacks > tcprexmtthresh ||
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((tcp_do_newreno || tp->sack_enable) &&
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IN_FASTRECOVERY(tp))) {
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if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
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int data_in_pipe;
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int awnd;
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/*
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* Compute the amount of data in flight first.
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@ -1850,9 +1849,9 @@ tcp_input(m, off0)
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* we have less than 1/2 the original window's
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* worth of data in flight.
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*/
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data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
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awnd = (tp->snd_nxt - tp->snd_fack) +
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tp->sackhint.sack_bytes_rexmit;
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if (data_in_pipe < tp->snd_ssthresh) {
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if (awnd < tp->snd_ssthresh) {
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tp->snd_cwnd += tp->t_maxseg;
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if (tp->snd_cwnd > tp->snd_ssthresh)
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tp->snd_cwnd = tp->snd_ssthresh;
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@ -1840,9 +1840,8 @@ tcp_input(m, off0)
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else if (++tp->t_dupacks > tcprexmtthresh ||
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((tcp_do_newreno || tp->sack_enable) &&
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IN_FASTRECOVERY(tp))) {
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if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
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int data_in_pipe;
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int awnd;
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/*
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* Compute the amount of data in flight first.
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@ -1850,9 +1849,9 @@ tcp_input(m, off0)
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* we have less than 1/2 the original window's
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* worth of data in flight.
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*/
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data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
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awnd = (tp->snd_nxt - tp->snd_fack) +
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tp->sackhint.sack_bytes_rexmit;
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if (data_in_pipe < tp->snd_ssthresh) {
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if (awnd < tp->snd_ssthresh) {
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tp->snd_cwnd += tp->t_maxseg;
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if (tp->snd_cwnd > tp->snd_ssthresh)
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tp->snd_cwnd = tp->snd_ssthresh;
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@ -389,12 +389,12 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
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}
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if (TAILQ_EMPTY(&tp->snd_holes))
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/*
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* Empty scoreboard. Need to initialize rcv_lastsack (it may be
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* Empty scoreboard. Need to initialize snd_fack (it may be
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* uninitialized or have a bogus value). Scoreboard holes
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* (from the sack blocks received) are created later below (in
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* the logic that adds holes to the tail of the scoreboard).
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*/
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tp->rcv_lastsack = tp->snd_una;
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tp->snd_fack = tp->snd_una;
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next_sack_blk = 0;
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cur = TAILQ_FIRST(&tp->snd_holes);
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/*
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@ -403,7 +403,7 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
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*/
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while ((next_sack_blk < num_sack_blks) && (cur != NULL)) {
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sack = sack_blocks[next_sack_blk];
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if (SEQ_LT(tp->rcv_lastsack, sack.start))
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if (SEQ_LT(tp->snd_fack, sack.start))
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/*
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* The sack block acks data to the right of all the holes
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* in the scoreboard. No need to iterate over the
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@ -495,19 +495,19 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
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* sack.start and sack.end seem redundant, but they're necessary
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* to deal with overlapping sack blocks.
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*/
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if (SEQ_LT(tp->rcv_lastsack, sack.start)) {
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if (SEQ_LT(tp->snd_fack, sack.start)) {
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/* Need to append new hole at end. */
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temp = tcp_sackhole_alloc(tp, tp->rcv_lastsack,
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temp = tcp_sackhole_alloc(tp, tp->snd_fack,
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sack.start);
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if (temp == NULL)
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continue; /* ENOBUFS */
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TAILQ_INSERT_TAIL(&tp->snd_holes, temp, scblink);
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tp->rcv_lastsack = sack.end;
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tp->snd_fack = sack.end;
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if (tp->sackhint.nexthole == NULL)
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tp->sackhint.nexthole = temp;
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}
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if (SEQ_LT(tp->rcv_lastsack, sack.end))
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tp->rcv_lastsack = sack.end;
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if (SEQ_LT(tp->snd_fack, sack.end))
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tp->snd_fack = sack.end;
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}
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return (0);
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}
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@ -689,12 +689,12 @@ tcp_sack_adjust(struct tcpcb *tp)
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INP_LOCK_ASSERT(tp->t_inpcb);
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if (cur == NULL)
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return; /* No holes */
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if (SEQ_GEQ(tp->snd_nxt, tp->rcv_lastsack))
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if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack))
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return; /* We're already beyond any SACKed blocks */
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/*
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* Two cases for which we want to advance snd_nxt:
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* i) snd_nxt lies between end of one hole and beginning of another
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* ii) snd_nxt lies between end of last hole and rcv_lastsack
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* ii) snd_nxt lies between end of last hole and snd_fack
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*/
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while ((p = TAILQ_NEXT(cur, scblink)) != NULL) {
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if (SEQ_LT(tp->snd_nxt, cur->end))
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@ -708,6 +708,6 @@ tcp_sack_adjust(struct tcpcb *tp)
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}
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if (SEQ_LT(tp->snd_nxt, cur->end))
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return;
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tp->snd_nxt = tp->rcv_lastsack;
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tp->snd_nxt = tp->snd_fack;
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return;
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}
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@ -192,7 +192,7 @@ struct tcpcb {
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int sack_enable; /* enable SACK for this connection */
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int snd_numholes; /* number of holes seen by sender */
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TAILQ_HEAD(, sackhole) snd_holes; /* SACK scoreboard (sorted) */
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tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/
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tcp_seq snd_fack; /* last seq number(+1) sack'd by rcv'r*/
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int rcv_numsacks; /* # distinct sack blks present */
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struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
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tcp_seq sack_newdata; /* New data xmitted in this recovery
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