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Introduce routines to alloc/free sack holes. This cleans up the code

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considerably.

Submitted by:   Noritoshi Demizu.
Reviewed by:    Raja Mukerji, Mohan Srinivasan.
This commit is contained in:
Paul Saab 2005-05-16 19:26:46 +00:00
parent 45c9b8cd6e
commit 4fc5324557
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=146304
1 changed files with 60 additions and 56 deletions
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116
sys/netinet/tcp_sack.c
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@ -285,6 +285,49 @@ tcp_clean_sackreport(tp)
tp->sackblks[i].start = tp->sackblks[i].end=0;
}
/*
* Allocate struct sackhole.
*/
static struct sackhole *
tcp_sackhole_alloc(struct tcpcb *tp, tcp_seq start, tcp_seq end)
{
struct sackhole *hole;
if (tp->snd_numholes >= tcp_sack_maxholes ||
tcp_sack_globalholes >= tcp_sack_globalmaxholes) {
tcpstat.tcps_sack_sboverflow++;
return NULL;
}
hole = (struct sackhole *)uma_zalloc(sack_hole_zone, M_NOWAIT);
if (hole == NULL)
return NULL;
hole->start = start;
hole->end = end;
hole->rxmit = start;
tp->snd_numholes++;
tcp_sack_globalholes++;
return hole;
}
/*
* Free struct sackhole.
*/
static void
tcp_sackhole_free(struct tcpcb *tp, struct sackhole *hole)
{
uma_zfree(sack_hole_zone, hole);
tp->snd_numholes--;
tcp_sack_globalholes--;
KASSERT(tp->snd_numholes >= 0, ("tp->snd_numholes >= 0"));
KASSERT(tcp_sack_globalholes >= 0, ("tcp_sack_globalholes >= 0"));
}
/*
* Process the TCP SACK option. Returns 1 if tcp_dooptions() should continue,
* and 0 otherwise, if the option was fine. tp->snd_holes is an ordered list
@ -311,8 +354,6 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
tmp_cp = cp + 2;
tmp_olen = optlen - 2;
tcpstat.tcps_sack_rcv_blocks++;
if (tp->snd_numholes < 0) /* XXX panic? */
tp->snd_numholes = 0;
if (tp->t_maxseg == 0)
panic("tcp_sack_option"); /* Should never happen */
while (tmp_olen > 0) {
@ -336,26 +377,15 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
if (SEQ_GT(sack.end, tp->snd_max))
continue;
if (TAILQ_EMPTY(&tp->snd_holes)) { /* first hole */
if (tcp_sack_globalholes >= tcp_sack_globalmaxholes ||
tcp_sack_maxholes == 0) {
tcpstat.tcps_sack_sboverflow++;
continue;
}
cur = (struct sackhole *)
uma_zalloc(sack_hole_zone,M_NOWAIT);
cur = tcp_sackhole_alloc(tp, th->th_ack, sack.start);
if (cur == NULL) {
/* ENOBUFS, so ignore SACKed block for now*/
continue;
}
cur->start = th->th_ack;
cur->end = sack.start;
cur->rxmit = cur->start;
tp->snd_numholes = 1;
tcp_sack_globalholes++;
TAILQ_INSERT_HEAD(&tp->snd_holes, cur, scblink);
tp->rcv_lastsack = sack.end;
/* Update the sack scoreboard "cache" */
tp->sackhint.nexthole = cur;
tp->rcv_lastsack = sack.end;
TAILQ_INSERT_HEAD(&tp->snd_holes, cur, scblink);
continue; /* with next sack block */
}
/* Go thru list of holes. */
@ -384,9 +414,7 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
cur = TAILQ_NEXT(cur, scblink);
TAILQ_REMOVE(&tp->snd_holes,
temp, scblink);
uma_zfree(sack_hole_zone, temp);
tp->snd_numholes--;
tcp_sack_globalholes--;
tcp_sackhole_free(tp, temp);
continue;
} else {
/* Move start of hole forward */
@ -402,31 +430,19 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
* ACKs some data in middle of a hole; need to
* split current hole
*/
if (tp->snd_numholes >= tcp_sack_maxholes ||
tcp_sack_globalholes >=
tcp_sack_globalmaxholes) {
tcpstat.tcps_sack_sboverflow++;
temp = NULL;
} else {
temp = (struct sackhole *)
uma_zalloc(sack_hole_zone,
M_NOWAIT);
}
temp = tcp_sackhole_alloc(tp, sack.end,
cur->end);
if (temp != NULL) {
temp->start = sack.end;
temp->end = cur->end;
temp->rxmit = SEQ_MAX(cur->rxmit,
temp->start);
if (SEQ_GT(cur->rxmit, temp->rxmit))
temp->rxmit = cur->rxmit;
TAILQ_INSERT_AFTER(&tp->snd_holes,
cur, temp, scblink);
cur->end = sack.start;
cur->rxmit = SEQ_MIN(cur->rxmit,
cur->end);
tp->sackhint.sack_bytes_rexmit +=
(cur->rxmit - cur->start);
TAILQ_INSERT_AFTER(&tp->snd_holes,
cur, temp, scblink);
cur = temp;
tp->snd_numholes++;
tcp_sack_globalholes++;
}
}
tp->sackhint.sack_bytes_rexmit +=
@ -436,22 +452,12 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
/* At this point, we have iterated the whole scoreboard. */
if (SEQ_LT(tp->rcv_lastsack, sack.start)) {
/* Need to append new hole at end. */
if (tp->snd_numholes >= tcp_sack_maxholes ||
tcp_sack_globalholes >= tcp_sack_globalmaxholes) {
tcpstat.tcps_sack_sboverflow++;
continue;
}
temp = (struct sackhole *)
uma_zalloc(sack_hole_zone,M_NOWAIT);
temp = tcp_sackhole_alloc(tp, tp->rcv_lastsack,
sack.start);
if (temp == NULL)
continue; /* ENOBUFS */
temp->start = tp->rcv_lastsack;
temp->end = sack.start;
temp->rxmit = temp->start;
tp->rcv_lastsack = sack.end;
tp->snd_numholes++;
tcp_sack_globalholes++;
TAILQ_INSERT_TAIL(&tp->snd_holes, temp, scblink);
tp->rcv_lastsack = sack.end;
if (tp->sackhint.nexthole == NULL)
tp->sackhint.nexthole = temp;
}
@ -488,9 +494,7 @@ tcp_del_sackholes(tp, th)
TAILQ_NEXT(cur, scblink);
cur = TAILQ_NEXT(cur, scblink);
TAILQ_REMOVE(&tp->snd_holes, prev, scblink);
uma_zfree(sack_hole_zone, prev);
tp->snd_numholes--;
tcp_sack_globalholes--;
tcp_sackhole_free(tp, prev);
} else if (SEQ_LT(cur->start, lastack)) {
if (SEQ_LT(cur->rxmit, lastack)) {
tp->sackhint.sack_bytes_rexmit -=
@ -514,12 +518,12 @@ tcp_free_sackholes(struct tcpcb *tp)
INP_LOCK_ASSERT(tp->t_inpcb);
while ((q = TAILQ_FIRST(&tp->snd_holes)) != NULL) {
TAILQ_REMOVE(&tp->snd_holes, q, scblink);
uma_zfree(sack_hole_zone, q);
tcp_sack_globalholes--;
tcp_sackhole_free(tp, q);
}
tp->snd_numholes = 0;
tp->sackhint.nexthole = NULL;
tp->sackhint.sack_bytes_rexmit = 0;
KASSERT(tp->snd_numholes == 0, ("tp->snd_numholes == 0"));
}
/*