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- RTO was not being initialized to 0, thus the rtt calculation

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algoritm would not go through the proper initialization.
- The initialization was incorrect as well, causing problems in
  sat networks with > 1sec RTT
- Get rid of magic numbers in RTT calculations.
This commit is contained in:
Randall Stewart 2007-06-08 10:57:11 +00:00
parent c59557f5d4
commit 108df27c0b
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=170428
5 changed files with 23 additions and 9 deletions
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2
sys/netinet/sctp_asconf.c
View File

@ -1794,7 +1794,7 @@ sctp_iterator_stcb(struct sctp_inpcb *inp, struct sctp_tcb *stcb, void *ptr,
* address?
*/
sctp_set_initial_cc_param(stcb, net);
net->RTO = stcb->asoc.initial_rto;
net->RTO = 0;
}
}

2
sys/netinet/sctp_input.c
View File

@ -2319,7 +2319,7 @@ sctp_handle_ecn_echo(struct sctp_ecne_chunk *cp,
if (net->ssthresh < net->mtu) {
net->ssthresh = net->mtu;
/* here back off the timer as well, to slow us down */
net->RTO <<= 2;
net->RTO <<= 1;
}
net->cwnd = net->ssthresh;
#ifdef SCTP_CWND_MONITOR

6
sys/netinet/sctp_pcb.c
View File

@ -3064,7 +3064,11 @@ sctp_add_remote_addr(struct sctp_tcb *stcb, struct sockaddr *newaddr,
net->dest_state = SCTP_ADDR_REACHABLE |
SCTP_ADDR_UNCONFIRMED;
}
net->RTO = stcb->asoc.initial_rto;
/*
* We set this to 0, the timer code knows that this means its an
* initial value
*/
net->RTO = 0;
stcb->asoc.numnets++;
*(&net->ref_count) = 1;
net->tos_flowlabel = 0;

3
sys/netinet/sctp_timer.h
View File

@ -37,6 +37,9 @@ __FBSDID("$FreeBSD$");
#if defined(_KERNEL)
#define SCTP_RTT_SHIFT 3
#define SCTP_RTT_VAR_SHIFT 2
void
sctp_early_fr_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
struct sctp_nets *net);

19
sys/netinet/sctputil.c
View File

@ -2577,24 +2577,31 @@ sctp_calculate_rto(struct sctp_tcb *stcb,
o_calctime = calc_time;
/* this is Van Jacobson's integer version */
if (net->RTO) {
calc_time -= (net->lastsa >> 3);
calc_time -= (net->lastsa >> SCTP_RTT_SHIFT); /* take away 1/8th when
* shift=3 */
#ifdef SCTP_RTTVAR_LOGGING
rto_logging(net, SCTP_LOG_RTTVAR);
#endif
net->prev_rtt = o_calctime;
net->lastsa += calc_time;
net->lastsa += calc_time; /* add 7/8th into sa when
* shift=3 */
if (calc_time < 0) {
calc_time = -calc_time;
}
calc_time -= (net->lastsv >> 2);
calc_time -= (net->lastsv >> SCTP_RTT_VAR_SHIFT); /* take away 1/4 when
* VAR shift=2 */
net->lastsv += calc_time;
if (net->lastsv == 0) {
net->lastsv = SCTP_CLOCK_GRANULARITY;
}
} else {
/* First RTO measurment */
net->lastsa = calc_time;
net->lastsv = calc_time >> 1;
net->lastsa = calc_time << SCTP_RTT_SHIFT; /* Multiply by 8 when
* shift=3 */
net->lastsv = calc_time;
if (net->lastsv == 0) {
net->lastsv = SCTP_CLOCK_GRANULARITY;
}
first_measure = 1;
net->prev_rtt = o_calctime;
#ifdef SCTP_RTTVAR_LOGGING
@ -2602,7 +2609,7 @@ sctp_calculate_rto(struct sctp_tcb *stcb,
#endif
}
calc_rto:
new_rto = ((net->lastsa >> 2) + net->lastsv) >> 1;
new_rto = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
if ((new_rto > SCTP_SAT_NETWORK_MIN) &&
(stcb->asoc.sat_network_lockout == 0)) {
stcb->asoc.sat_network = 1;