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This is conform with the terminology in

Browse Source 
M.Mathis and J.Mahdavi,
  "Forward Acknowledgement: Refining TCP Congestion Control"
  SIGCOMM'96, August 1996.

Submitted by:   Noritoshi Demizu, Raja Mukerji
This commit is contained in:
ps 2005-05-25 17:55:27 +00:00
parent a0ef9a2b74
commit 8512119a50
4 changed files with 18 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
sys/netinet/tcp_input.c
View File

@ -1840,9 +1840,8 @@ trimthenstep6:
else if (++tp->t_dupacks > tcprexmtthresh ||
((tcp_do_newreno || tp->sack_enable) &&
IN_FASTRECOVERY(tp))) {
if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
int data_in_pipe;
int awnd;
/*
* Compute the amount of data in flight first.
@ -1850,9 +1849,9 @@ trimthenstep6:
* we have less than 1/2 the original window's
* worth of data in flight.
*/
data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
awnd = (tp->snd_nxt - tp->snd_fack) +
tp->sackhint.sack_bytes_rexmit;
if (data_in_pipe < tp->snd_ssthresh) {
if (awnd < tp->snd_ssthresh) {
tp->snd_cwnd += tp->t_maxseg;
if (tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;

7
sys/netinet/tcp_reass.c
View File

@ -1840,9 +1840,8 @@ trimthenstep6:
else if (++tp->t_dupacks > tcprexmtthresh ||
((tcp_do_newreno || tp->sack_enable) &&
IN_FASTRECOVERY(tp))) {
if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
int data_in_pipe;
int awnd;
/*
* Compute the amount of data in flight first.
@ -1850,9 +1849,9 @@ trimthenstep6:
* we have less than 1/2 the original window's
* worth of data in flight.
*/
data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
awnd = (tp->snd_nxt - tp->snd_fack) +
tp->sackhint.sack_bytes_rexmit;
if (data_in_pipe < tp->snd_ssthresh) {
if (awnd < tp->snd_ssthresh) {
tp->snd_cwnd += tp->t_maxseg;
if (tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;

22
sys/netinet/tcp_sack.c
View File

@ -389,12 +389,12 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
}
if (TAILQ_EMPTY(&tp->snd_holes))
/*
* Empty scoreboard. Need to initialize rcv_lastsack (it may be
* Empty scoreboard. Need to initialize snd_fack (it may be
* uninitialized or have a bogus value). Scoreboard holes
* (from the sack blocks received) are created later below (in
* the logic that adds holes to the tail of the scoreboard).
*/
tp->rcv_lastsack = tp->snd_una;
tp->snd_fack = tp->snd_una;
next_sack_blk = 0;
cur = TAILQ_FIRST(&tp->snd_holes);
/*
@ -403,7 +403,7 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
*/
while ((next_sack_blk < num_sack_blks) && (cur != NULL)) {
sack = sack_blocks[next_sack_blk];
if (SEQ_LT(tp->rcv_lastsack, sack.start))
if (SEQ_LT(tp->snd_fack, sack.start))
/*
* The sack block acks data to the right of all the holes
* in the scoreboard. No need to iterate over the
@ -495,19 +495,19 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
* sack.start and sack.end seem redundant, but they're necessary
* to deal with overlapping sack blocks.
*/
if (SEQ_LT(tp->rcv_lastsack, sack.start)) {
if (SEQ_LT(tp->snd_fack, sack.start)) {
/* Need to append new hole at end. */
temp = tcp_sackhole_alloc(tp, tp->rcv_lastsack,
temp = tcp_sackhole_alloc(tp, tp->snd_fack,
sack.start);
if (temp == NULL)
continue; /* ENOBUFS */
TAILQ_INSERT_TAIL(&tp->snd_holes, temp, scblink);
tp->rcv_lastsack = sack.end;
tp->snd_fack = sack.end;
if (tp->sackhint.nexthole == NULL)
tp->sackhint.nexthole = temp;
}
if (SEQ_LT(tp->rcv_lastsack, sack.end))
tp->rcv_lastsack = sack.end;
if (SEQ_LT(tp->snd_fack, sack.end))
tp->snd_fack = sack.end;
}
return (0);
}
@ -689,12 +689,12 @@ tcp_sack_adjust(struct tcpcb *tp)
INP_LOCK_ASSERT(tp->t_inpcb);
if (cur == NULL)
return; /* No holes */
if (SEQ_GEQ(tp->snd_nxt, tp->rcv_lastsack))
if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack))
return; /* We're already beyond any SACKed blocks */
/*
* Two cases for which we want to advance snd_nxt:
* i) snd_nxt lies between end of one hole and beginning of another
* ii) snd_nxt lies between end of last hole and rcv_lastsack
* ii) snd_nxt lies between end of last hole and snd_fack
*/
while ((p = TAILQ_NEXT(cur, scblink)) != NULL) {
if (SEQ_LT(tp->snd_nxt, cur->end))
@ -708,6 +708,6 @@ tcp_sack_adjust(struct tcpcb *tp)
}
if (SEQ_LT(tp->snd_nxt, cur->end))
return;
tp->snd_nxt = tp->rcv_lastsack;
tp->snd_nxt = tp->snd_fack;
return;
}

2
sys/netinet/tcp_var.h
View File

@ -192,7 +192,7 @@ struct tcpcb {
int sack_enable; /* enable SACK for this connection */
int snd_numholes; /* number of holes seen by sender */
TAILQ_HEAD(, sackhole) snd_holes; /* SACK scoreboard (sorted) */
tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/
tcp_seq snd_fack; /* last seq number(+1) sack'd by rcv'r*/
int rcv_numsacks; /* # distinct sack blks present */
struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
tcp_seq sack_newdata; /* New data xmitted in this recovery