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freebsd-skq/sys/netinet/sctp_cc_functions.c
pfg 779a64139d netinet/sctp*: minor spelling fixes in comments. 
No functional change.

Reviewed by:	tuexen
2016-05-02 20:56:11 +00:00

2374 lines
69 KiB
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/*-
* Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
* Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
* Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* a) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* b) Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
*
* c) Neither the name of Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <netinet/sctp_os.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_timer.h>
#include <netinet/sctp_auth.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_dtrace_declare.h>
#define SHIFT_MPTCP_MULTI_N 40
#define SHIFT_MPTCP_MULTI_Z 16
#define SHIFT_MPTCP_MULTI 8
static void
sctp_enforce_cwnd_limit(struct sctp_association *assoc, struct sctp_nets *net)
{
if ((assoc->max_cwnd > 0) &&
(net->cwnd > assoc->max_cwnd) &&
(net->cwnd > (net->mtu - sizeof(struct sctphdr)))) {
net->cwnd = assoc->max_cwnd;
if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) {
net->cwnd = net->mtu - sizeof(struct sctphdr);
}
}
}
static void
sctp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
{
struct sctp_association *assoc;
uint32_t cwnd_in_mtu;
assoc = &stcb->asoc;
cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
if (cwnd_in_mtu == 0) {
/* Using 0 means that the value of RFC 4960 is used. */
net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
} else {
/*
* We take the minimum of the burst limit and the initial
* congestion window.
*/
if ((assoc->max_burst > 0) && (cwnd_in_mtu > assoc->max_burst))
cwnd_in_mtu = assoc->max_burst;
net->cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
}
if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
(stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) {
/* In case of resource pooling initialize appropriately */
net->cwnd /= assoc->numnets;
if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) {
net->cwnd = net->mtu - sizeof(struct sctphdr);
}
}
sctp_enforce_cwnd_limit(assoc, net);
net->ssthresh = assoc->peers_rwnd;
SDT_PROBE5(sctp, cwnd, net, init,
stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
0, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) &
(SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) {
sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION);
}
}
static void
sctp_cwnd_update_after_fr(struct sctp_tcb *stcb,
struct sctp_association *asoc)
{
struct sctp_nets *net;
uint32_t t_ssthresh, t_cwnd;
uint64_t t_ucwnd_sbw;
/* MT FIXME: Don't compute this over and over again */
t_ssthresh = 0;
t_cwnd = 0;
t_ucwnd_sbw = 0;
if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) ||
(asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) {
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
t_ssthresh += net->ssthresh;
t_cwnd += net->cwnd;
if (net->lastsa > 0) {
t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) net->lastsa;
}
}
if (t_ucwnd_sbw == 0) {
t_ucwnd_sbw = 1;
}
}
/*-
* CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
* (net->fast_retran_loss_recovery == 0)))
*/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
if ((asoc->fast_retran_loss_recovery == 0) ||
(asoc->sctp_cmt_on_off > 0)) {
/* out of a RFC2582 Fast recovery window? */
if (net->net_ack > 0) {
/*
* per section 7.2.3, are there any
* destinations that had a fast retransmit
* to them. If so what we need to do is
* adjust ssthresh and cwnd.
*/
struct sctp_tmit_chunk *lchk;
int old_cwnd = net->cwnd;
if ((asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) ||
(asoc->sctp_cmt_on_off == SCTP_CMT_RPV2)) {
if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV1) {
net->ssthresh = (uint32_t) (((uint64_t) 4 *
(uint64_t) net->mtu *
(uint64_t) net->ssthresh) /
(uint64_t) t_ssthresh);
}
if (asoc->sctp_cmt_on_off == SCTP_CMT_RPV2) {
uint32_t srtt;
srtt = net->lastsa;
/*
* lastsa>>3; we don't need
* to devide ...
*/
if (srtt == 0) {
srtt = 1;
}
/*
* Short Version => Equal to
* Contel Version MBe
*/
net->ssthresh = (uint32_t) (((uint64_t) 4 *
(uint64_t) net->mtu *
(uint64_t) net->cwnd) /
((uint64_t) srtt *
t_ucwnd_sbw));
/* INCREASE FACTOR */ ;
}
if ((net->cwnd > t_cwnd / 2) &&
(net->ssthresh < net->cwnd - t_cwnd / 2)) {
net->ssthresh = net->cwnd - t_cwnd / 2;
}
if (net->ssthresh < net->mtu) {
net->ssthresh = net->mtu;
}
} else {
net->ssthresh = net->cwnd / 2;
if (net->ssthresh < (net->mtu * 2)) {
net->ssthresh = 2 * net->mtu;
}
}
net->cwnd = net->ssthresh;
sctp_enforce_cwnd_limit(asoc, net);
SDT_PROBE5(sctp, cwnd, net, fr,
stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
SCTP_CWND_LOG_FROM_FR);
}
lchk = TAILQ_FIRST(&asoc->send_queue);
net->partial_bytes_acked = 0;
/* Turn on fast recovery window */
asoc->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
asoc->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
/*
* CMT fast recovery -- per destination
* recovery variable.
*/
net->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
net->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net,
SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_1);
sctp_timer_start(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net);
}
} else if (net->net_ack > 0) {
/*
* Mark a peg that we WOULD have done a cwnd
* reduction but RFC2582 prevented this action.
*/
SCTP_STAT_INCR(sctps_fastretransinrtt);
}
}
}
/* Defines for instantaneous bw decisions */
#define SCTP_INST_LOOSING 1 /* Losing to other flows */
#define SCTP_INST_NEUTRAL 2 /* Neutral, no indication */
#define SCTP_INST_GAINING 3 /* Gaining, step down possible */
static int
cc_bw_same(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw,
uint64_t rtt_offset, uint64_t vtag, uint8_t inst_ind)
{
uint64_t oth, probepoint;
probepoint = (((uint64_t) net->cwnd) << 32);
if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
/*
* rtt increased we don't update bw.. so we don't update the
* rtt either.
*/
/* Probe point 5 */
probepoint |= ((5 << 16) | 1);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) {
if (net->cc_mod.rtcc.last_step_state == 5)
net->cc_mod.rtcc.step_cnt++;
else
net->cc_mod.rtcc.step_cnt = 1;
net->cc_mod.rtcc.last_step_state = 5;
if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) ||
((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) &&
((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) {
/* Try a step down */
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
if (net->cwnd > (4 * net->mtu)) {
net->cwnd -= net->mtu;
net->cc_mod.rtcc.vol_reduce++;
} else {
net->cc_mod.rtcc.step_cnt = 0;
}
}
}
return (1);
}
if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
/*
* rtt decreased, there could be more room. we update both
* the bw and the rtt here to lock this in as a good step
* down.
*/
/* Probe point 6 */
probepoint |= ((6 << 16) | 0);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if (net->cc_mod.rtcc.steady_step) {
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
if ((net->cc_mod.rtcc.last_step_state == 5) &&
(net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step)) {
/* Step down worked */
net->cc_mod.rtcc.step_cnt = 0;
return (1);
} else {
net->cc_mod.rtcc.last_step_state = 6;
net->cc_mod.rtcc.step_cnt = 0;
}
}
net->cc_mod.rtcc.lbw = nbw;
net->cc_mod.rtcc.lbw_rtt = net->rtt;
net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
if (inst_ind == SCTP_INST_GAINING)
return (1);
else if (inst_ind == SCTP_INST_NEUTRAL)
return (1);
else
return (0);
}
/*
* Ok bw and rtt remained the same .. no update to any
*/
/* Probe point 7 */
probepoint |= ((7 << 16) | net->cc_mod.rtcc.ret_from_eq);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if ((net->cc_mod.rtcc.steady_step) && (inst_ind != SCTP_INST_LOOSING)) {
if (net->cc_mod.rtcc.last_step_state == 5)
net->cc_mod.rtcc.step_cnt++;
else
net->cc_mod.rtcc.step_cnt = 1;
net->cc_mod.rtcc.last_step_state = 5;
if ((net->cc_mod.rtcc.step_cnt == net->cc_mod.rtcc.steady_step) ||
((net->cc_mod.rtcc.step_cnt > net->cc_mod.rtcc.steady_step) &&
((net->cc_mod.rtcc.step_cnt % net->cc_mod.rtcc.steady_step) == 0))) {
/* Try a step down */
if (net->cwnd > (4 * net->mtu)) {
net->cwnd -= net->mtu;
net->cc_mod.rtcc.vol_reduce++;
return (1);
} else {
net->cc_mod.rtcc.step_cnt = 0;
}
}
}
if (inst_ind == SCTP_INST_GAINING)
return (1);
else if (inst_ind == SCTP_INST_NEUTRAL)
return (1);
else
return ((int)net->cc_mod.rtcc.ret_from_eq);
}
static int
cc_bw_decrease(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t rtt_offset,
uint64_t vtag, uint8_t inst_ind)
{
uint64_t oth, probepoint;
/* Bandwidth decreased. */
probepoint = (((uint64_t) net->cwnd) << 32);
if (net->rtt > net->cc_mod.rtcc.lbw_rtt + rtt_offset) {
/* rtt increased */
/* Did we add more */
if ((net->cwnd > net->cc_mod.rtcc.cwnd_at_bw_set) &&
(inst_ind != SCTP_INST_LOOSING)) {
/* We caused it maybe.. back off? */
/* PROBE POINT 1 */
probepoint |= ((1 << 16) | 1);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if (net->cc_mod.rtcc.ret_from_eq) {
/*
* Switch over to CA if we are less
* aggressive
*/
net->ssthresh = net->cwnd - 1;
net->partial_bytes_acked = 0;
}
return (1);
}
/* Probe point 2 */
probepoint |= ((2 << 16) | 0);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
/* Someone else - fight for more? */
if (net->cc_mod.rtcc.steady_step) {
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
/*
* Did we voluntarily give up some? if so take one
* back please
*/
if ((net->cc_mod.rtcc.vol_reduce) &&
(inst_ind != SCTP_INST_GAINING)) {
net->cwnd += net->mtu;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
net->cc_mod.rtcc.vol_reduce--;
}
net->cc_mod.rtcc.last_step_state = 2;
net->cc_mod.rtcc.step_cnt = 0;
}
goto out_decision;
} else if (net->rtt < net->cc_mod.rtcc.lbw_rtt - rtt_offset) {
/* bw & rtt decreased */
/* Probe point 3 */
probepoint |= ((3 << 16) | 0);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if (net->cc_mod.rtcc.steady_step) {
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
if ((net->cc_mod.rtcc.vol_reduce) &&
(inst_ind != SCTP_INST_GAINING)) {
net->cwnd += net->mtu;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
net->cc_mod.rtcc.vol_reduce--;
}
net->cc_mod.rtcc.last_step_state = 3;
net->cc_mod.rtcc.step_cnt = 0;
}
goto out_decision;
}
/* The bw decreased but rtt stayed the same */
/* Probe point 4 */
probepoint |= ((4 << 16) | 0);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if (net->cc_mod.rtcc.steady_step) {
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
if ((net->cc_mod.rtcc.vol_reduce) &&
(inst_ind != SCTP_INST_GAINING)) {
net->cwnd += net->mtu;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
net->cc_mod.rtcc.vol_reduce--;
}
net->cc_mod.rtcc.last_step_state = 4;
net->cc_mod.rtcc.step_cnt = 0;
}
out_decision:
net->cc_mod.rtcc.lbw = nbw;
net->cc_mod.rtcc.lbw_rtt = net->rtt;
net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
if (inst_ind == SCTP_INST_GAINING) {
return (1);
} else {
return (0);
}
}
static int
cc_bw_increase(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw, uint64_t vtag)
{
uint64_t oth, probepoint;
/*
* BW increased, so update and return 0, since all actions in our
* table say to do the normal CC update. Note that we pay no
* attention to the inst_ind since our overall sum is increasing.
*/
/* PROBE POINT 0 */
probepoint = (((uint64_t) net->cwnd) << 32);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
if (net->cc_mod.rtcc.steady_step) {
oth = net->cc_mod.rtcc.vol_reduce;
oth <<= 16;
oth |= net->cc_mod.rtcc.step_cnt;
oth <<= 16;
oth |= net->cc_mod.rtcc.last_step_state;
SDT_PROBE5(sctp, cwnd, net, rttstep,
vtag,
((net->cc_mod.rtcc.lbw << 32) | nbw),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
oth,
probepoint);
net->cc_mod.rtcc.last_step_state = 0;
net->cc_mod.rtcc.step_cnt = 0;
net->cc_mod.rtcc.vol_reduce = 0;
}
net->cc_mod.rtcc.lbw = nbw;
net->cc_mod.rtcc.lbw_rtt = net->rtt;
net->cc_mod.rtcc.cwnd_at_bw_set = net->cwnd;
return (0);
}
/* RTCC Algorithm to limit growth of cwnd, return
* true if you want to NOT allow cwnd growth
*/
static int
cc_bw_limit(struct sctp_tcb *stcb, struct sctp_nets *net, uint64_t nbw)
{
uint64_t bw_offset, rtt_offset;
uint64_t probepoint, rtt, vtag;
uint64_t bytes_for_this_rtt, inst_bw;
uint64_t div, inst_off;
int bw_shift;
uint8_t inst_ind;
int ret;
/*-
* Here we need to see if we want
* to limit cwnd growth due to increase
* in overall rtt but no increase in bw.
* We use the following table to figure
* out what we should do. When we return
* 0, cc update goes on as planned. If we
* return 1, then no cc update happens and cwnd
* stays where it is at.
* ----------------------------------
* BW | RTT | Action
* *********************************
* INC | INC | return 0
* ----------------------------------
* INC | SAME | return 0
* ----------------------------------
* INC | DECR | return 0
* ----------------------------------
* SAME | INC | return 1
* ----------------------------------
* SAME | SAME | return 1
* ----------------------------------
* SAME | DECR | return 0
* ----------------------------------
* DECR | INC | return 0 or 1 based on if we caused.
* ----------------------------------
* DECR | SAME | return 0
* ----------------------------------
* DECR | DECR | return 0
* ----------------------------------
*
* We are a bit fuzz on what an increase or
* decrease is. For BW it is the same if
* it did not change within 1/64th. For
* RTT it stayed the same if it did not
* change within 1/32nd
*/
bw_shift = SCTP_BASE_SYSCTL(sctp_rttvar_bw);
rtt = stcb->asoc.my_vtag;
vtag = (rtt << 32) | (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) | (stcb->rport);
probepoint = (((uint64_t) net->cwnd) << 32);
rtt = net->rtt;
if (net->cc_mod.rtcc.rtt_set_this_sack) {
net->cc_mod.rtcc.rtt_set_this_sack = 0;
bytes_for_this_rtt = net->cc_mod.rtcc.bw_bytes - net->cc_mod.rtcc.bw_bytes_at_last_rttc;
net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes;
if (net->rtt) {
div = net->rtt / 1000;
if (div) {
inst_bw = bytes_for_this_rtt / div;
inst_off = inst_bw >> bw_shift;
if (inst_bw > nbw)
inst_ind = SCTP_INST_GAINING;
else if ((inst_bw + inst_off) < nbw)
inst_ind = SCTP_INST_LOOSING;
else
inst_ind = SCTP_INST_NEUTRAL;
probepoint |= ((0xb << 16) | inst_ind);
} else {
inst_ind = net->cc_mod.rtcc.last_inst_ind;
inst_bw = bytes_for_this_rtt / (uint64_t) (net->rtt);
/* Can't determine do not change */
probepoint |= ((0xc << 16) | inst_ind);
}
} else {
inst_ind = net->cc_mod.rtcc.last_inst_ind;
inst_bw = bytes_for_this_rtt;
/* Can't determine do not change */
probepoint |= ((0xd << 16) | inst_ind);
}
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((nbw << 32) | inst_bw),
((net->cc_mod.rtcc.lbw_rtt << 32) | rtt),
net->flight_size,
probepoint);
} else {
/* No rtt measurement, use last one */
inst_ind = net->cc_mod.rtcc.last_inst_ind;
}
bw_offset = net->cc_mod.rtcc.lbw >> bw_shift;
if (nbw > net->cc_mod.rtcc.lbw + bw_offset) {
ret = cc_bw_increase(stcb, net, nbw, vtag);
goto out;
}
rtt_offset = net->cc_mod.rtcc.lbw_rtt >> SCTP_BASE_SYSCTL(sctp_rttvar_rtt);
if (nbw < net->cc_mod.rtcc.lbw - bw_offset) {
ret = cc_bw_decrease(stcb, net, nbw, rtt_offset, vtag, inst_ind);
goto out;
}
/*
* If we reach here then we are in a situation where the bw stayed
* the same.
*/
ret = cc_bw_same(stcb, net, nbw, rtt_offset, vtag, inst_ind);
out:
net->cc_mod.rtcc.last_inst_ind = inst_ind;
return (ret);
}
static void
sctp_cwnd_update_after_sack_common(struct sctp_tcb *stcb,
struct sctp_association *asoc,
int accum_moved, int reneged_all SCTP_UNUSED, int will_exit, int use_rtcc)
{
struct sctp_nets *net;
int old_cwnd;
uint32_t t_ssthresh, t_cwnd, incr;
uint64_t t_ucwnd_sbw;
uint64_t t_path_mptcp;
uint64_t mptcp_like_alpha;
uint32_t srtt;
uint64_t max_path;
/* MT FIXME: Don't compute this over and over again */
t_ssthresh = 0;
t_cwnd = 0;
t_ucwnd_sbw = 0;
t_path_mptcp = 0;
mptcp_like_alpha = 1;
if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
(stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2) ||
(stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) {
max_path = 0;
TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
t_ssthresh += net->ssthresh;
t_cwnd += net->cwnd;
/* lastsa>>3; we don't need to devide ... */
srtt = net->lastsa;
if (srtt > 0) {
uint64_t tmp;
t_ucwnd_sbw += (uint64_t) net->cwnd / (uint64_t) srtt;
t_path_mptcp += (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_Z) /
(((uint64_t) net->mtu) * (uint64_t) srtt);
tmp = (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_N) /
((uint64_t) net->mtu * (uint64_t) (srtt * srtt));
if (tmp > max_path) {
max_path = tmp;
}
}
}
if (t_path_mptcp > 0) {
mptcp_like_alpha = max_path / (t_path_mptcp * t_path_mptcp);
} else {
mptcp_like_alpha = 1;
}
}
if (t_ssthresh == 0) {
t_ssthresh = 1;
}
if (t_ucwnd_sbw == 0) {
t_ucwnd_sbw = 1;
}
/******************************/
/* update cwnd and Early FR */
/******************************/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code. Need to debug.
*/
if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
net->will_exit_fast_recovery = 1;
}
}
#endif
/* if nothing was acked on this destination skip it */
if (net->net_ack == 0) {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
}
continue;
}
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code
*/
/*
* if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
* && net->will_exit_fast_recovery == 0) { @@@ Do something
* } else if (sctp_cmt_on_off == 0 &&
* asoc->fast_retran_loss_recovery && will_exit == 0) {
*/
#endif
if (asoc->fast_retran_loss_recovery &&
(will_exit == 0) &&
(asoc->sctp_cmt_on_off == 0)) {
/*
* If we are in loss recovery we skip any cwnd
* update
*/
return;
}
/*
* Did any measurements go on for this network?
*/
if (use_rtcc && (net->cc_mod.rtcc.tls_needs_set > 0)) {
uint64_t nbw;
/*
* At this point our bw_bytes has been updated by
* incoming sack information.
*
* But our bw may not yet be set.
*
*/
if ((net->cc_mod.rtcc.new_tot_time / 1000) > 0) {
nbw = net->cc_mod.rtcc.bw_bytes / (net->cc_mod.rtcc.new_tot_time / 1000);
} else {
nbw = net->cc_mod.rtcc.bw_bytes;
}
if (net->cc_mod.rtcc.lbw) {
if (cc_bw_limit(stcb, net, nbw)) {
/* Hold here, no update */
continue;
}
} else {
uint64_t vtag, probepoint;
probepoint = (((uint64_t) net->cwnd) << 32);
probepoint |= ((0xa << 16) | 0);
vtag = (net->rtt << 32) |
(((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
(stcb->rport);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
nbw,
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
net->cc_mod.rtcc.lbw = nbw;
net->cc_mod.rtcc.lbw_rtt = net->rtt;
if (net->cc_mod.rtcc.rtt_set_this_sack) {
net->cc_mod.rtcc.rtt_set_this_sack = 0;
net->cc_mod.rtcc.bw_bytes_at_last_rttc = net->cc_mod.rtcc.bw_bytes;
}
}
}
/*
* CMT: CUC algorithm. Update cwnd if pseudo-cumack has
* moved.
*/
if (accum_moved ||
((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
/* If the cumulative ack moved we can proceed */
if (net->cwnd <= net->ssthresh) {
/* We are in slow start */
if (net->flight_size + net->net_ack >= net->cwnd) {
uint32_t limit;
old_cwnd = net->cwnd;
switch (asoc->sctp_cmt_on_off) {
case SCTP_CMT_RPV1:
limit = (uint32_t) (((uint64_t) net->mtu *
(uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable) *
(uint64_t) net->ssthresh) /
(uint64_t) t_ssthresh);
incr = (uint32_t) (((uint64_t) net->net_ack *
(uint64_t) net->ssthresh) /
(uint64_t) t_ssthresh);
if (incr > limit) {
incr = limit;
}
if (incr == 0) {
incr = 1;
}
break;
case SCTP_CMT_RPV2:
/*
* lastsa>>3; we don't need
* to divide ...
*/
srtt = net->lastsa;
if (srtt == 0) {
srtt = 1;
}
limit = (uint32_t) (((uint64_t) net->mtu *
(uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable) *
(uint64_t) net->cwnd) /
((uint64_t) srtt * t_ucwnd_sbw));
/* INCREASE FACTOR */
incr = (uint32_t) (((uint64_t) net->net_ack *
(uint64_t) net->cwnd) /
((uint64_t) srtt * t_ucwnd_sbw));
/* INCREASE FACTOR */
if (incr > limit) {
incr = limit;
}
if (incr == 0) {
incr = 1;
}
break;
case SCTP_CMT_MPTCP:
limit = (uint32_t) (((uint64_t) net->mtu *
mptcp_like_alpha *
(uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) >>
SHIFT_MPTCP_MULTI);
incr = (uint32_t) (((uint64_t) net->net_ack *
mptcp_like_alpha) >>
SHIFT_MPTCP_MULTI);
if (incr > limit) {
incr = limit;
}
if (incr > net->net_ack) {
incr = net->net_ack;
}
if (incr > net->mtu) {
incr = net->mtu;
}
break;
default:
incr = net->net_ack;
if (incr > net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) {
incr = net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable);
}
break;
}
net->cwnd += incr;
sctp_enforce_cwnd_limit(asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, incr,
SCTP_CWND_LOG_FROM_SS);
}
SDT_PROBE5(sctp, cwnd, net, ack,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_SS);
}
}
} else {
/* We are in congestion avoidance */
/*
* Add to pba
*/
net->partial_bytes_acked += net->net_ack;
if ((net->flight_size + net->net_ack >= net->cwnd) &&
(net->partial_bytes_acked >= net->cwnd)) {
net->partial_bytes_acked -= net->cwnd;
old_cwnd = net->cwnd;
switch (asoc->sctp_cmt_on_off) {
case SCTP_CMT_RPV1:
incr = (uint32_t) (((uint64_t) net->mtu *
(uint64_t) net->ssthresh) /
(uint64_t) t_ssthresh);
if (incr == 0) {
incr = 1;
}
break;
case SCTP_CMT_RPV2:
/*
* lastsa>>3; we don't need
* to divide ...
*/
srtt = net->lastsa;
if (srtt == 0) {
srtt = 1;
}
incr = (uint32_t) ((uint64_t) net->mtu *
(uint64_t) net->cwnd /
((uint64_t) srtt *
t_ucwnd_sbw));
/* INCREASE FACTOR */
if (incr == 0) {
incr = 1;
}
break;
case SCTP_CMT_MPTCP:
incr = (uint32_t) ((mptcp_like_alpha *
(uint64_t) net->cwnd) >>
SHIFT_MPTCP_MULTI);
if (incr > net->mtu) {
incr = net->mtu;
}
break;
default:
incr = net->mtu;
break;
}
net->cwnd += incr;
sctp_enforce_cwnd_limit(asoc, net);
SDT_PROBE5(sctp, cwnd, net, ack,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_FROM_CA);
}
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_CA);
}
}
}
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_NO_CUMACK);
}
}
}
}
static void
sctp_cwnd_update_exit_pf_common(struct sctp_tcb *stcb, struct sctp_nets *net)
{
int old_cwnd;
old_cwnd = net->cwnd;
net->cwnd = net->mtu;
SDT_PROBE5(sctp, cwnd, net, ack,
stcb->asoc.my_vtag, ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)), net,
old_cwnd, net->cwnd);
SCTPDBG(SCTP_DEBUG_INDATA1, "Destination %p moved from PF to reachable with cwnd %d.\n",
(void *)net, net->cwnd);
}
static void
sctp_cwnd_update_after_timeout(struct sctp_tcb *stcb, struct sctp_nets *net)
{
int old_cwnd = net->cwnd;
uint32_t t_ssthresh, t_cwnd;
uint64_t t_ucwnd_sbw;
/* MT FIXME: Don't compute this over and over again */
t_ssthresh = 0;
t_cwnd = 0;
if ((stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) ||
(stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV2)) {
struct sctp_nets *lnet;
uint32_t srtt;
t_ucwnd_sbw = 0;
TAILQ_FOREACH(lnet, &stcb->asoc.nets, sctp_next) {
t_ssthresh += lnet->ssthresh;
t_cwnd += lnet->cwnd;
srtt = lnet->lastsa;
/* lastsa>>3; we don't need to divide ... */
if (srtt > 0) {
t_ucwnd_sbw += (uint64_t) lnet->cwnd / (uint64_t) srtt;
}
}
if (t_ssthresh < 1) {
t_ssthresh = 1;
}
if (t_ucwnd_sbw < 1) {
t_ucwnd_sbw = 1;
}
if (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_RPV1) {
net->ssthresh = (uint32_t) (((uint64_t) 4 *
(uint64_t) net->mtu *
(uint64_t) net->ssthresh) /
(uint64_t) t_ssthresh);
} else {
uint64_t cc_delta;
srtt = net->lastsa;
/* lastsa>>3; we don't need to divide ... */
if (srtt == 0) {
srtt = 1;
}
cc_delta = t_ucwnd_sbw * (uint64_t) srtt / 2;
if (cc_delta < t_cwnd) {
net->ssthresh = (uint32_t) ((uint64_t) t_cwnd - cc_delta);
} else {
net->ssthresh = net->mtu;
}
}
if ((net->cwnd > t_cwnd / 2) &&
(net->ssthresh < net->cwnd - t_cwnd / 2)) {
net->ssthresh = net->cwnd - t_cwnd / 2;
}
if (net->ssthresh < net->mtu) {
net->ssthresh = net->mtu;
}
} else {
net->ssthresh = max(net->cwnd / 2, 4 * net->mtu);
}
net->cwnd = net->mtu;
net->partial_bytes_acked = 0;
SDT_PROBE5(sctp, cwnd, net, to,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
}
}
static void
sctp_cwnd_update_after_ecn_echo_common(struct sctp_tcb *stcb, struct sctp_nets *net,
int in_window, int num_pkt_lost, int use_rtcc)
{
int old_cwnd = net->cwnd;
if ((use_rtcc) && (net->lan_type == SCTP_LAN_LOCAL) && (net->cc_mod.rtcc.use_dccc_ecn)) {
/* Data center Congestion Control */
if (in_window == 0) {
/*
* Go to CA with the cwnd at the point we sent the
* TSN that was marked with a CE.
*/
if (net->ecn_prev_cwnd < net->cwnd) {
/* Restore to prev cwnd */
net->cwnd = net->ecn_prev_cwnd - (net->mtu * num_pkt_lost);
} else {
/* Just cut in 1/2 */
net->cwnd /= 2;
}
/* Drop to CA */
net->ssthresh = net->cwnd - (num_pkt_lost * net->mtu);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
}
} else {
/*
* Further tuning down required over the drastic
* original cut
*/
net->ssthresh -= (net->mtu * num_pkt_lost);
net->cwnd -= (net->mtu * num_pkt_lost);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
}
}
SCTP_STAT_INCR(sctps_ecnereducedcwnd);
} else {
if (in_window == 0) {
SCTP_STAT_INCR(sctps_ecnereducedcwnd);
net->ssthresh = net->cwnd / 2;
if (net->ssthresh < net->mtu) {
net->ssthresh = net->mtu;
/*
* here back off the timer as well, to slow
* us down
*/
net->RTO <<= 1;
}
net->cwnd = net->ssthresh;
SDT_PROBE5(sctp, cwnd, net, ecn,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
}
}
}
}
static void
sctp_cwnd_update_after_packet_dropped(struct sctp_tcb *stcb,
struct sctp_nets *net, struct sctp_pktdrop_chunk *cp,
uint32_t * bottle_bw, uint32_t * on_queue)
{
uint32_t bw_avail;
unsigned int incr;
int old_cwnd = net->cwnd;
/* get bottle neck bw */
*bottle_bw = ntohl(cp->bottle_bw);
/* and whats on queue */
*on_queue = ntohl(cp->current_onq);
/*
* adjust the on-queue if our flight is more it could be that the
* router has not yet gotten data "in-flight" to it
*/
if (*on_queue < net->flight_size) {
*on_queue = net->flight_size;
}
/* rtt is measured in micro seconds, bottle_bw in bytes per second */
bw_avail = (uint32_t) (((uint64_t) (*bottle_bw) * net->rtt) / (uint64_t) 1000000);
if (bw_avail > *bottle_bw) {
/*
* Cap the growth to no more than the bottle neck. This can
* happen as RTT slides up due to queues. It also means if
* you have more than a 1 second RTT with a empty queue you
* will be limited to the bottle_bw per second no matter if
* other points have 1/2 the RTT and you could get more
* out...
*/
bw_avail = *bottle_bw;
}
if (*on_queue > bw_avail) {
/*
* No room for anything else don't allow anything else to be
* "added to the fire".
*/
int seg_inflight, seg_onqueue, my_portion;
net->partial_bytes_acked = 0;
/* how much are we over queue size? */
incr = *on_queue - bw_avail;
if (stcb->asoc.seen_a_sack_this_pkt) {
/*
* undo any cwnd adjustment that the sack might have
* made
*/
net->cwnd = net->prev_cwnd;
}
/* Now how much of that is mine? */
seg_inflight = net->flight_size / net->mtu;
seg_onqueue = *on_queue / net->mtu;
my_portion = (incr * seg_inflight) / seg_onqueue;
/* Have I made an adjustment already */
if (net->cwnd > net->flight_size) {
/*
* for this flight I made an adjustment we need to
* decrease the portion by a share our previous
* adjustment.
*/
int diff_adj;
diff_adj = net->cwnd - net->flight_size;
if (diff_adj > my_portion)
my_portion = 0;
else
my_portion -= diff_adj;
}
/*
* back down to the previous cwnd (assume we have had a sack
* before this packet). minus what ever portion of the
* overage is my fault.
*/
net->cwnd -= my_portion;
/* we will NOT back down more than 1 MTU */
if (net->cwnd <= net->mtu) {
net->cwnd = net->mtu;
}
/* force into CA */
net->ssthresh = net->cwnd - 1;
} else {
/*
* Take 1/4 of the space left or max burst up .. whichever
* is less.
*/
incr = (bw_avail - *on_queue) >> 2;
if ((stcb->asoc.max_burst > 0) &&
(stcb->asoc.max_burst * net->mtu < incr)) {
incr = stcb->asoc.max_burst * net->mtu;
}
net->cwnd += incr;
}
if (net->cwnd > bw_avail) {
/* We can't exceed the pipe size */
net->cwnd = bw_avail;
}
if (net->cwnd < net->mtu) {
/* We always have 1 MTU */
net->cwnd = net->mtu;
}
sctp_enforce_cwnd_limit(&stcb->asoc, net);
if (net->cwnd - old_cwnd != 0) {
/* log only changes */
SDT_PROBE5(sctp, cwnd, net, pd,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
SCTP_CWND_LOG_FROM_SAT);
}
}
}
static void
sctp_cwnd_update_after_output(struct sctp_tcb *stcb,
struct sctp_nets *net, int burst_limit)
{
int old_cwnd = net->cwnd;
if (net->ssthresh < net->cwnd)
net->ssthresh = net->cwnd;
if (burst_limit) {
net->cwnd = (net->flight_size + (burst_limit * net->mtu));
sctp_enforce_cwnd_limit(&stcb->asoc, net);
SDT_PROBE5(sctp, cwnd, net, bl,
stcb->asoc.my_vtag,
((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
net,
old_cwnd, net->cwnd);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_BRST);
}
}
}
static void
sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
struct sctp_association *asoc,
int accum_moved, int reneged_all, int will_exit)
{
/* Passing a zero argument in last disables the rtcc algorithm */
sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 0);
}
static void
sctp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
int in_window, int num_pkt_lost)
{
/* Passing a zero argument in last disables the rtcc algorithm */
sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 0);
}
/* Here starts the RTCCVAR type CC invented by RRS which
* is a slight mod to RFC2581. We reuse a common routine or
* two since these algorithms are so close and need to
* remain the same.
*/
static void
sctp_cwnd_update_rtcc_after_ecn_echo(struct sctp_tcb *stcb, struct sctp_nets *net,
int in_window, int num_pkt_lost)
{
sctp_cwnd_update_after_ecn_echo_common(stcb, net, in_window, num_pkt_lost, 1);
}
static
void
sctp_cwnd_update_rtcc_tsn_acknowledged(struct sctp_nets *net,
struct sctp_tmit_chunk *tp1)
{
net->cc_mod.rtcc.bw_bytes += tp1->send_size;
}
static void
sctp_cwnd_prepare_rtcc_net_for_sack(struct sctp_tcb *stcb SCTP_UNUSED,
struct sctp_nets *net)
{
if (net->cc_mod.rtcc.tls_needs_set > 0) {
/* We had a bw measurment going on */
struct timeval ltls;
SCTP_GETPTIME_TIMEVAL(&ltls);
timevalsub(&ltls, &net->cc_mod.rtcc.tls);
net->cc_mod.rtcc.new_tot_time = (ltls.tv_sec * 1000000) + ltls.tv_usec;
}
}
static void
sctp_cwnd_new_rtcc_transmission_begins(struct sctp_tcb *stcb,
struct sctp_nets *net)
{
uint64_t vtag, probepoint;
if (net->cc_mod.rtcc.lbw) {
/* Clear the old bw.. we went to 0 in-flight */
vtag = (net->rtt << 32) | (((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
(stcb->rport);
probepoint = (((uint64_t) net->cwnd) << 32);
/* Probe point 8 */
probepoint |= ((8 << 16) | 0);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
((net->cc_mod.rtcc.lbw << 32) | 0),
((net->cc_mod.rtcc.lbw_rtt << 32) | net->rtt),
net->flight_size,
probepoint);
net->cc_mod.rtcc.lbw_rtt = 0;
net->cc_mod.rtcc.cwnd_at_bw_set = 0;
net->cc_mod.rtcc.lbw = 0;
net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0;
net->cc_mod.rtcc.vol_reduce = 0;
net->cc_mod.rtcc.bw_tot_time = 0;
net->cc_mod.rtcc.bw_bytes = 0;
net->cc_mod.rtcc.tls_needs_set = 0;
if (net->cc_mod.rtcc.steady_step) {
net->cc_mod.rtcc.vol_reduce = 0;
net->cc_mod.rtcc.step_cnt = 0;
net->cc_mod.rtcc.last_step_state = 0;
}
if (net->cc_mod.rtcc.ret_from_eq) {
/* less aggressive one - reset cwnd too */
uint32_t cwnd_in_mtu, cwnd;
cwnd_in_mtu = SCTP_BASE_SYSCTL(sctp_initial_cwnd);
if (cwnd_in_mtu == 0) {
/*
* Using 0 means that the value of RFC 4960
* is used.
*/
cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
} else {
/*
* We take the minimum of the burst limit
* and the initial congestion window.
*/
if ((stcb->asoc.max_burst > 0) && (cwnd_in_mtu > stcb->asoc.max_burst))
cwnd_in_mtu = stcb->asoc.max_burst;
cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
}
if (net->cwnd > cwnd) {
/*
* Only set if we are not a timeout (i.e.
* down to 1 mtu)
*/
net->cwnd = cwnd;
}
}
}
}
static void
sctp_set_rtcc_initial_cc_param(struct sctp_tcb *stcb,
struct sctp_nets *net)
{
uint64_t vtag, probepoint;
sctp_set_initial_cc_param(stcb, net);
stcb->asoc.use_precise_time = 1;
probepoint = (((uint64_t) net->cwnd) << 32);
probepoint |= ((9 << 16) | 0);
vtag = (net->rtt << 32) |
(((uint32_t) (stcb->sctp_ep->sctp_lport)) << 16) |
(stcb->rport);
SDT_PROBE5(sctp, cwnd, net, rttvar,
vtag,
0,
0,
0,
probepoint);
net->cc_mod.rtcc.lbw_rtt = 0;
net->cc_mod.rtcc.cwnd_at_bw_set = 0;
net->cc_mod.rtcc.vol_reduce = 0;
net->cc_mod.rtcc.lbw = 0;
net->cc_mod.rtcc.vol_reduce = 0;
net->cc_mod.rtcc.bw_bytes_at_last_rttc = 0;
net->cc_mod.rtcc.bw_tot_time = 0;
net->cc_mod.rtcc.bw_bytes = 0;
net->cc_mod.rtcc.tls_needs_set = 0;
net->cc_mod.rtcc.ret_from_eq = SCTP_BASE_SYSCTL(sctp_rttvar_eqret);
net->cc_mod.rtcc.steady_step = SCTP_BASE_SYSCTL(sctp_steady_step);
net->cc_mod.rtcc.use_dccc_ecn = SCTP_BASE_SYSCTL(sctp_use_dccc_ecn);
net->cc_mod.rtcc.step_cnt = 0;
net->cc_mod.rtcc.last_step_state = 0;
}
static int
sctp_cwnd_rtcc_socket_option(struct sctp_tcb *stcb, int setorget,
struct sctp_cc_option *cc_opt)
{
struct sctp_nets *net;
if (setorget == 1) {
/* a set */
if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) {
if ((cc_opt->aid_value.assoc_value != 0) &&
(cc_opt->aid_value.assoc_value != 1)) {
return (EINVAL);
}
TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
net->cc_mod.rtcc.ret_from_eq = cc_opt->aid_value.assoc_value;
}
} else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) {
if ((cc_opt->aid_value.assoc_value != 0) &&
(cc_opt->aid_value.assoc_value != 1)) {
return (EINVAL);
}
TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
net->cc_mod.rtcc.use_dccc_ecn = cc_opt->aid_value.assoc_value;
}
} else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) {
TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
net->cc_mod.rtcc.steady_step = cc_opt->aid_value.assoc_value;
}
} else {
return (EINVAL);
}
} else {
/* a get */
if (cc_opt->option == SCTP_CC_OPT_RTCC_SETMODE) {
net = TAILQ_FIRST(&stcb->asoc.nets);
if (net == NULL) {
return (EFAULT);
}
cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.ret_from_eq;
} else if (cc_opt->option == SCTP_CC_OPT_USE_DCCC_ECN) {
net = TAILQ_FIRST(&stcb->asoc.nets);
if (net == NULL) {
return (EFAULT);
}
cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.use_dccc_ecn;
} else if (cc_opt->option == SCTP_CC_OPT_STEADY_STEP) {
net = TAILQ_FIRST(&stcb->asoc.nets);
if (net == NULL) {
return (EFAULT);
}
cc_opt->aid_value.assoc_value = net->cc_mod.rtcc.steady_step;
} else {
return (EINVAL);
}
}
return (0);
}
static void
sctp_cwnd_update_rtcc_packet_transmitted(struct sctp_tcb *stcb SCTP_UNUSED,
struct sctp_nets *net)
{
if (net->cc_mod.rtcc.tls_needs_set == 0) {
SCTP_GETPTIME_TIMEVAL(&net->cc_mod.rtcc.tls);
net->cc_mod.rtcc.tls_needs_set = 2;
}
}
static void
sctp_cwnd_update_rtcc_after_sack(struct sctp_tcb *stcb,
struct sctp_association *asoc,
int accum_moved, int reneged_all, int will_exit)
{
/* Passing a one argument at the last enables the rtcc algorithm */
sctp_cwnd_update_after_sack_common(stcb, asoc, accum_moved, reneged_all, will_exit, 1);
}
static void
sctp_rtt_rtcc_calculated(struct sctp_tcb *stcb SCTP_UNUSED,
struct sctp_nets *net,
struct timeval *now SCTP_UNUSED)
{
net->cc_mod.rtcc.rtt_set_this_sack = 1;
}
/* Here starts Sally Floyds HS-TCP */
struct sctp_hs_raise_drop {
int32_t cwnd;
int8_t increase;
int8_t drop_percent;
};
#define SCTP_HS_TABLE_SIZE 73
static const struct sctp_hs_raise_drop sctp_cwnd_adjust[SCTP_HS_TABLE_SIZE] = {
{38, 1, 50}, /* 0 */
{118, 2, 44}, /* 1 */
{221, 3, 41}, /* 2 */
{347, 4, 38}, /* 3 */
{495, 5, 37}, /* 4 */
{663, 6, 35}, /* 5 */
{851, 7, 34}, /* 6 */
{1058, 8, 33}, /* 7 */
{1284, 9, 32}, /* 8 */
{1529, 10, 31}, /* 9 */
{1793, 11, 30}, /* 10 */
{2076, 12, 29}, /* 11 */
{2378, 13, 28}, /* 12 */
{2699, 14, 28}, /* 13 */
{3039, 15, 27}, /* 14 */
{3399, 16, 27}, /* 15 */
{3778, 17, 26}, /* 16 */
{4177, 18, 26}, /* 17 */
{4596, 19, 25}, /* 18 */
{5036, 20, 25}, /* 19 */
{5497, 21, 24}, /* 20 */
{5979, 22, 24}, /* 21 */
{6483, 23, 23}, /* 22 */
{7009, 24, 23}, /* 23 */
{7558, 25, 22}, /* 24 */
{8130, 26, 22}, /* 25 */
{8726, 27, 22}, /* 26 */
{9346, 28, 21}, /* 27 */
{9991, 29, 21}, /* 28 */
{10661, 30, 21}, /* 29 */
{11358, 31, 20}, /* 30 */
{12082, 32, 20}, /* 31 */
{12834, 33, 20}, /* 32 */
{13614, 34, 19}, /* 33 */
{14424, 35, 19}, /* 34 */
{15265, 36, 19}, /* 35 */
{16137, 37, 19}, /* 36 */
{17042, 38, 18}, /* 37 */
{17981, 39, 18}, /* 38 */
{18955, 40, 18}, /* 39 */
{19965, 41, 17}, /* 40 */
{21013, 42, 17}, /* 41 */
{22101, 43, 17}, /* 42 */
{23230, 44, 17}, /* 43 */
{24402, 45, 16}, /* 44 */
{25618, 46, 16}, /* 45 */
{26881, 47, 16}, /* 46 */
{28193, 48, 16}, /* 47 */
{29557, 49, 15}, /* 48 */
{30975, 50, 15}, /* 49 */
{32450, 51, 15}, /* 50 */
{33986, 52, 15}, /* 51 */
{35586, 53, 14}, /* 52 */
{37253, 54, 14}, /* 53 */
{38992, 55, 14}, /* 54 */
{40808, 56, 14}, /* 55 */
{42707, 57, 13}, /* 56 */
{44694, 58, 13}, /* 57 */
{46776, 59, 13}, /* 58 */
{48961, 60, 13}, /* 59 */
{51258, 61, 13}, /* 60 */
{53677, 62, 12}, /* 61 */
{56230, 63, 12}, /* 62 */
{58932, 64, 12}, /* 63 */
{61799, 65, 12}, /* 64 */
{64851, 66, 11}, /* 65 */
{68113, 67, 11}, /* 66 */
{71617, 68, 11}, /* 67 */
{75401, 69, 10}, /* 68 */
{79517, 70, 10}, /* 69 */
{84035, 71, 10}, /* 70 */
{89053, 72, 10}, /* 71 */
{94717, 73, 9} /* 72 */
};
static void
sctp_hs_cwnd_increase(struct sctp_tcb *stcb, struct sctp_nets *net)
{
int cur_val, i, indx, incr;
int old_cwnd = net->cwnd;
cur_val = net->cwnd >> 10;
indx = SCTP_HS_TABLE_SIZE - 1;
if (cur_val < sctp_cwnd_adjust[0].cwnd) {
/* normal mode */
if (net->net_ack > net->mtu) {
net->cwnd += net->mtu;
} else {
net->cwnd += net->net_ack;
}
} else {
for (i = net->last_hs_used; i < SCTP_HS_TABLE_SIZE; i++) {
if (cur_val < sctp_cwnd_adjust[i].cwnd) {
indx = i;
break;
}
}
net->last_hs_used = indx;
incr = (((int32_t) sctp_cwnd_adjust[indx].increase) << 10);
net->cwnd += incr;
}
sctp_enforce_cwnd_limit(&stcb->asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SS);
}
}
static void
sctp_hs_cwnd_decrease(struct sctp_tcb *stcb, struct sctp_nets *net)
{
int cur_val, i, indx;
int old_cwnd = net->cwnd;
cur_val = net->cwnd >> 10;
if (cur_val < sctp_cwnd_adjust[0].cwnd) {
/* normal mode */
net->ssthresh = net->cwnd / 2;
if (net->ssthresh < (net->mtu * 2)) {
net->ssthresh = 2 * net->mtu;
}
net->cwnd = net->ssthresh;
} else {
/* drop by the proper amount */
net->ssthresh = net->cwnd - (int)((net->cwnd / 100) *
(int32_t) sctp_cwnd_adjust[net->last_hs_used].drop_percent);
net->cwnd = net->ssthresh;
/* now where are we */
indx = net->last_hs_used;
cur_val = net->cwnd >> 10;
/* reset where we are in the table */
if (cur_val < sctp_cwnd_adjust[0].cwnd) {
/* feel out of hs */
net->last_hs_used = 0;
} else {
for (i = indx; i >= 1; i--) {
if (cur_val > sctp_cwnd_adjust[i - 1].cwnd) {
break;
}
}
net->last_hs_used = indx;
}
}
sctp_enforce_cwnd_limit(&stcb->asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_FR);
}
}
static void
sctp_hs_cwnd_update_after_fr(struct sctp_tcb *stcb,
struct sctp_association *asoc)
{
struct sctp_nets *net;
/*
* CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
* (net->fast_retran_loss_recovery == 0)))
*/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
if ((asoc->fast_retran_loss_recovery == 0) ||
(asoc->sctp_cmt_on_off > 0)) {
/* out of a RFC2582 Fast recovery window? */
if (net->net_ack > 0) {
/*
* per section 7.2.3, are there any
* destinations that had a fast retransmit
* to them. If so what we need to do is
* adjust ssthresh and cwnd.
*/
struct sctp_tmit_chunk *lchk;
sctp_hs_cwnd_decrease(stcb, net);
lchk = TAILQ_FIRST(&asoc->send_queue);
net->partial_bytes_acked = 0;
/* Turn on fast recovery window */
asoc->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
asoc->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
/*
* CMT fast recovery -- per destination
* recovery variable.
*/
net->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
net->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net,
SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_2);
sctp_timer_start(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net);
}
} else if (net->net_ack > 0) {
/*
* Mark a peg that we WOULD have done a cwnd
* reduction but RFC2582 prevented this action.
*/
SCTP_STAT_INCR(sctps_fastretransinrtt);
}
}
}
static void
sctp_hs_cwnd_update_after_sack(struct sctp_tcb *stcb,
struct sctp_association *asoc,
int accum_moved, int reneged_all SCTP_UNUSED, int will_exit)
{
struct sctp_nets *net;
/******************************/
/* update cwnd and Early FR */
/******************************/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code. Need to debug.
*/
if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
net->will_exit_fast_recovery = 1;
}
}
#endif
/* if nothing was acked on this destination skip it */
if (net->net_ack == 0) {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
}
continue;
}
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code
*/
/*
* if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
* && net->will_exit_fast_recovery == 0) { @@@ Do something
* } else if (sctp_cmt_on_off == 0 &&
* asoc->fast_retran_loss_recovery && will_exit == 0) {
*/
#endif
if (asoc->fast_retran_loss_recovery &&
(will_exit == 0) &&
(asoc->sctp_cmt_on_off == 0)) {
/*
* If we are in loss recovery we skip any cwnd
* update
*/
return;
}
/*
* CMT: CUC algorithm. Update cwnd if pseudo-cumack has
* moved.
*/
if (accum_moved ||
((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
/* If the cumulative ack moved we can proceed */
if (net->cwnd <= net->ssthresh) {
/* We are in slow start */
if (net->flight_size + net->net_ack >= net->cwnd) {
sctp_hs_cwnd_increase(stcb, net);
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_SS);
}
}
} else {
/* We are in congestion avoidance */
net->partial_bytes_acked += net->net_ack;
if ((net->flight_size + net->net_ack >= net->cwnd) &&
(net->partial_bytes_acked >= net->cwnd)) {
net->partial_bytes_acked -= net->cwnd;
net->cwnd += net->mtu;
sctp_enforce_cwnd_limit(asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_FROM_CA);
}
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_CA);
}
}
}
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_NO_CUMACK);
}
}
}
}
/*
* H-TCP congestion control. The algorithm is detailed in:
* R.N.Shorten, D.J.Leith:
* "H-TCP: TCP for high-speed and long-distance networks"
* Proc. PFLDnet, Argonne, 2004.
* http://www.hamilton.ie/net/htcp3.pdf
*/
static int use_rtt_scaling = 1;
static int use_bandwidth_switch = 1;
static inline int
between(uint32_t seq1, uint32_t seq2, uint32_t seq3)
{
return (seq3 - seq2 >= seq1 - seq2);
}
static inline uint32_t
htcp_cong_time(struct htcp *ca)
{
return (sctp_get_tick_count() - ca->last_cong);
}
static inline uint32_t
htcp_ccount(struct htcp *ca)
{
return (htcp_cong_time(ca) / ca->minRTT);
}
static inline void
htcp_reset(struct htcp *ca)
{
ca->undo_last_cong = ca->last_cong;
ca->undo_maxRTT = ca->maxRTT;
ca->undo_old_maxB = ca->old_maxB;
ca->last_cong = sctp_get_tick_count();
}
#ifdef SCTP_NOT_USED
static uint32_t
htcp_cwnd_undo(struct sctp_tcb *stcb, struct sctp_nets *net)
{
net->cc_mod.htcp_ca.last_cong = net->cc_mod.htcp_ca.undo_last_cong;
net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.undo_maxRTT;
net->cc_mod.htcp_ca.old_maxB = net->cc_mod.htcp_ca.undo_old_maxB;
return (max(net->cwnd, ((net->ssthresh / net->mtu << 7) / net->cc_mod.htcp_ca.beta) * net->mtu));
}
#endif
static inline void
measure_rtt(struct sctp_nets *net)
{
uint32_t srtt = net->lastsa >> SCTP_RTT_SHIFT;
/* keep track of minimum RTT seen so far, minRTT is zero at first */
if (net->cc_mod.htcp_ca.minRTT > srtt || !net->cc_mod.htcp_ca.minRTT)
net->cc_mod.htcp_ca.minRTT = srtt;
/* max RTT */
if (net->fast_retran_ip == 0 && net->ssthresh < 0xFFFF && htcp_ccount(&net->cc_mod.htcp_ca) > 3) {
if (net->cc_mod.htcp_ca.maxRTT < net->cc_mod.htcp_ca.minRTT)
net->cc_mod.htcp_ca.maxRTT = net->cc_mod.htcp_ca.minRTT;
if (net->cc_mod.htcp_ca.maxRTT < srtt && srtt <= net->cc_mod.htcp_ca.maxRTT + MSEC_TO_TICKS(20))
net->cc_mod.htcp_ca.maxRTT = srtt;
}
}
static void
measure_achieved_throughput(struct sctp_nets *net)
{
uint32_t now = sctp_get_tick_count();
if (net->fast_retran_ip == 0)
net->cc_mod.htcp_ca.bytes_acked = net->net_ack;
if (!use_bandwidth_switch)
return;
/* achieved throughput calculations */
/* JRS - not 100% sure of this statement */
if (net->fast_retran_ip == 1) {
net->cc_mod.htcp_ca.bytecount = 0;
net->cc_mod.htcp_ca.lasttime = now;
return;
}
net->cc_mod.htcp_ca.bytecount += net->net_ack;
if ((net->cc_mod.htcp_ca.bytecount >= net->cwnd - (((net->cc_mod.htcp_ca.alpha >> 7) ? (net->cc_mod.htcp_ca.alpha >> 7) : 1) * net->mtu)) &&
(now - net->cc_mod.htcp_ca.lasttime >= net->cc_mod.htcp_ca.minRTT) &&
(net->cc_mod.htcp_ca.minRTT > 0)) {
uint32_t cur_Bi = net->cc_mod.htcp_ca.bytecount / net->mtu * hz / (now - net->cc_mod.htcp_ca.lasttime);
if (htcp_ccount(&net->cc_mod.htcp_ca) <= 3) {
/* just after backoff */
net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi = cur_Bi;
} else {
net->cc_mod.htcp_ca.Bi = (3 * net->cc_mod.htcp_ca.Bi + cur_Bi) / 4;
if (net->cc_mod.htcp_ca.Bi > net->cc_mod.htcp_ca.maxB)
net->cc_mod.htcp_ca.maxB = net->cc_mod.htcp_ca.Bi;
if (net->cc_mod.htcp_ca.minB > net->cc_mod.htcp_ca.maxB)
net->cc_mod.htcp_ca.minB = net->cc_mod.htcp_ca.maxB;
}
net->cc_mod.htcp_ca.bytecount = 0;
net->cc_mod.htcp_ca.lasttime = now;
}
}
static inline void
htcp_beta_update(struct htcp *ca, uint32_t minRTT, uint32_t maxRTT)
{
if (use_bandwidth_switch) {
uint32_t maxB = ca->maxB;
uint32_t old_maxB = ca->old_maxB;
ca->old_maxB = ca->maxB;
if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
ca->beta = BETA_MIN;
ca->modeswitch = 0;
return;
}
}
if (ca->modeswitch && minRTT > (uint32_t) MSEC_TO_TICKS(10) && maxRTT) {
ca->beta = (minRTT << 7) / maxRTT;
if (ca->beta < BETA_MIN)
ca->beta = BETA_MIN;
else if (ca->beta > BETA_MAX)
ca->beta = BETA_MAX;
} else {
ca->beta = BETA_MIN;
ca->modeswitch = 1;
}
}
static inline void
htcp_alpha_update(struct htcp *ca)
{
uint32_t minRTT = ca->minRTT;
uint32_t factor = 1;
uint32_t diff = htcp_cong_time(ca);
if (diff > (uint32_t) hz) {
diff -= hz;
factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / hz)) / hz;
}
if (use_rtt_scaling && minRTT) {
uint32_t scale = (hz << 3) / (10 * minRTT);
scale = min(max(scale, 1U << 2), 10U << 3); /* clamping ratio to
* interval [0.5,10]<<3 */
factor = (factor << 3) / scale;
if (!factor)
factor = 1;
}
ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
if (!ca->alpha)
ca->alpha = ALPHA_BASE;
}
/* After we have the rtt data to calculate beta, we'd still prefer to wait one
* rtt before we adjust our beta to ensure we are working from a consistent
* data.
*
* This function should be called when we hit a congestion event since only at
* that point do we really have a real sense of maxRTT (the queues en route
* were getting just too full now).
*/
static void
htcp_param_update(struct sctp_nets *net)
{
uint32_t minRTT = net->cc_mod.htcp_ca.minRTT;
uint32_t maxRTT = net->cc_mod.htcp_ca.maxRTT;
htcp_beta_update(&net->cc_mod.htcp_ca, minRTT, maxRTT);
htcp_alpha_update(&net->cc_mod.htcp_ca);
/*
* add slowly fading memory for maxRTT to accommodate routing
* changes etc
*/
if (minRTT > 0 && maxRTT > minRTT)
net->cc_mod.htcp_ca.maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
}
static uint32_t
htcp_recalc_ssthresh(struct sctp_nets *net)
{
htcp_param_update(net);
return (max(((net->cwnd / net->mtu * net->cc_mod.htcp_ca.beta) >> 7) * net->mtu, 2U * net->mtu));
}
static void
htcp_cong_avoid(struct sctp_tcb *stcb, struct sctp_nets *net)
{
/*-
* How to handle these functions?
* if (!tcp_is_cwnd_limited(sk, in_flight)) RRS - good question.
* return;
*/
if (net->cwnd <= net->ssthresh) {
/* We are in slow start */
if (net->flight_size + net->net_ack >= net->cwnd) {
if (net->net_ack > (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable))) {
net->cwnd += (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable));
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_FROM_SS);
}
} else {
net->cwnd += net->net_ack;
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_FROM_SS);
}
}
sctp_enforce_cwnd_limit(&stcb->asoc, net);
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_SS);
}
}
} else {
measure_rtt(net);
/*
* In dangerous area, increase slowly. In theory this is
* net->cwnd += alpha / net->cwnd
*/
/* What is snd_cwnd_cnt?? */
if (((net->partial_bytes_acked / net->mtu * net->cc_mod.htcp_ca.alpha) >> 7) * net->mtu >= net->cwnd) {
/*-
* Does SCTP have a cwnd clamp?
* if (net->snd_cwnd < net->snd_cwnd_clamp) - Nope (RRS).
*/
net->cwnd += net->mtu;
net->partial_bytes_acked = 0;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
htcp_alpha_update(&net->cc_mod.htcp_ca);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_FROM_CA);
}
} else {
net->partial_bytes_acked += net->net_ack;
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->net_ack,
SCTP_CWND_LOG_NOADV_CA);
}
}
net->cc_mod.htcp_ca.bytes_acked = net->mtu;
}
}
#ifdef SCTP_NOT_USED
/* Lower bound on congestion window. */
static uint32_t
htcp_min_cwnd(struct sctp_tcb *stcb, struct sctp_nets *net)
{
return (net->ssthresh);
}
#endif
static void
htcp_init(struct sctp_nets *net)
{
memset(&net->cc_mod.htcp_ca, 0, sizeof(struct htcp));
net->cc_mod.htcp_ca.alpha = ALPHA_BASE;
net->cc_mod.htcp_ca.beta = BETA_MIN;
net->cc_mod.htcp_ca.bytes_acked = net->mtu;
net->cc_mod.htcp_ca.last_cong = sctp_get_tick_count();
}
static void
sctp_htcp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
{
/*
* We take the max of the burst limit times a MTU or the
* INITIAL_CWND. We then limit this to 4 MTU's of sending.
*/
net->cwnd = min((net->mtu * 4), max((2 * net->mtu), SCTP_INITIAL_CWND));
net->ssthresh = stcb->asoc.peers_rwnd;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
htcp_init(net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_CWND_MONITOR_ENABLE | SCTP_CWND_LOGGING_ENABLE)) {
sctp_log_cwnd(stcb, net, 0, SCTP_CWND_INITIALIZATION);
}
}
static void
sctp_htcp_cwnd_update_after_sack(struct sctp_tcb *stcb,
struct sctp_association *asoc,
int accum_moved, int reneged_all SCTP_UNUSED, int will_exit)
{
struct sctp_nets *net;
/******************************/
/* update cwnd and Early FR */
/******************************/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code. Need to debug.
*/
if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
net->will_exit_fast_recovery = 1;
}
}
#endif
/* if nothing was acked on this destination skip it */
if (net->net_ack == 0) {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, 0, SCTP_CWND_LOG_FROM_SACK);
}
continue;
}
#ifdef JANA_CMT_FAST_RECOVERY
/*
* CMT fast recovery code
*/
/*
* if (sctp_cmt_on_off > 0 && net->fast_retran_loss_recovery
* && net->will_exit_fast_recovery == 0) { @@@ Do something
* } else if (sctp_cmt_on_off == 0 &&
* asoc->fast_retran_loss_recovery && will_exit == 0) {
*/
#endif
if (asoc->fast_retran_loss_recovery &&
will_exit == 0 &&
(asoc->sctp_cmt_on_off == 0)) {
/*
* If we are in loss recovery we skip any cwnd
* update
*/
return;
}
/*
* CMT: CUC algorithm. Update cwnd if pseudo-cumack has
* moved.
*/
if (accum_moved ||
((asoc->sctp_cmt_on_off > 0) && net->new_pseudo_cumack)) {
htcp_cong_avoid(stcb, net);
measure_achieved_throughput(net);
} else {
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
sctp_log_cwnd(stcb, net, net->mtu,
SCTP_CWND_LOG_NO_CUMACK);
}
}
}
}
static void
sctp_htcp_cwnd_update_after_fr(struct sctp_tcb *stcb,
struct sctp_association *asoc)
{
struct sctp_nets *net;
/*
* CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
* (net->fast_retran_loss_recovery == 0)))
*/
TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
if ((asoc->fast_retran_loss_recovery == 0) ||
(asoc->sctp_cmt_on_off > 0)) {
/* out of a RFC2582 Fast recovery window? */
if (net->net_ack > 0) {
/*
* per section 7.2.3, are there any
* destinations that had a fast retransmit
* to them. If so what we need to do is
* adjust ssthresh and cwnd.
*/
struct sctp_tmit_chunk *lchk;
int old_cwnd = net->cwnd;
/* JRS - reset as if state were changed */
htcp_reset(&net->cc_mod.htcp_ca);
net->ssthresh = htcp_recalc_ssthresh(net);
net->cwnd = net->ssthresh;
sctp_enforce_cwnd_limit(asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd),
SCTP_CWND_LOG_FROM_FR);
}
lchk = TAILQ_FIRST(&asoc->send_queue);
net->partial_bytes_acked = 0;
/* Turn on fast recovery window */
asoc->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
asoc->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
/*
* CMT fast recovery -- per destination
* recovery variable.
*/
net->fast_retran_loss_recovery = 1;
if (lchk == NULL) {
/* Mark end of the window */
net->fast_recovery_tsn = asoc->sending_seq - 1;
} else {
net->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
}
sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net,
SCTP_FROM_SCTP_CC_FUNCTIONS + SCTP_LOC_3);
sctp_timer_start(SCTP_TIMER_TYPE_SEND,
stcb->sctp_ep, stcb, net);
}
} else if (net->net_ack > 0) {
/*
* Mark a peg that we WOULD have done a cwnd
* reduction but RFC2582 prevented this action.
*/
SCTP_STAT_INCR(sctps_fastretransinrtt);
}
}
}
static void
sctp_htcp_cwnd_update_after_timeout(struct sctp_tcb *stcb,
struct sctp_nets *net)
{
int old_cwnd = net->cwnd;
/* JRS - reset as if the state were being changed to timeout */
htcp_reset(&net->cc_mod.htcp_ca);
net->ssthresh = htcp_recalc_ssthresh(net);
net->cwnd = net->mtu;
net->partial_bytes_acked = 0;
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, net->cwnd - old_cwnd, SCTP_CWND_LOG_FROM_RTX);
}
}
static void
sctp_htcp_cwnd_update_after_ecn_echo(struct sctp_tcb *stcb,
struct sctp_nets *net, int in_window, int num_pkt_lost SCTP_UNUSED)
{
int old_cwnd;
old_cwnd = net->cwnd;
/* JRS - reset hctp as if state changed */
if (in_window == 0) {
htcp_reset(&net->cc_mod.htcp_ca);
SCTP_STAT_INCR(sctps_ecnereducedcwnd);
net->ssthresh = htcp_recalc_ssthresh(net);
if (net->ssthresh < net->mtu) {
net->ssthresh = net->mtu;
/* here back off the timer as well, to slow us down */
net->RTO <<= 1;
}
net->cwnd = net->ssthresh;
sctp_enforce_cwnd_limit(&stcb->asoc, net);
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
sctp_log_cwnd(stcb, net, (net->cwnd - old_cwnd), SCTP_CWND_LOG_FROM_SAT);
}
}
}
const struct sctp_cc_functions sctp_cc_functions[] = {
{
.sctp_set_initial_cc_param = sctp_set_initial_cc_param,
.sctp_cwnd_update_after_sack = sctp_cwnd_update_after_sack,
.sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
.sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
.sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
.sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
.sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
.sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
},
{
.sctp_set_initial_cc_param = sctp_set_initial_cc_param,
.sctp_cwnd_update_after_sack = sctp_hs_cwnd_update_after_sack,
.sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
.sctp_cwnd_update_after_fr = sctp_hs_cwnd_update_after_fr,
.sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
.sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_after_ecn_echo,
.sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
.sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
},
{
.sctp_set_initial_cc_param = sctp_htcp_set_initial_cc_param,
.sctp_cwnd_update_after_sack = sctp_htcp_cwnd_update_after_sack,
.sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
.sctp_cwnd_update_after_fr = sctp_htcp_cwnd_update_after_fr,
.sctp_cwnd_update_after_timeout = sctp_htcp_cwnd_update_after_timeout,
.sctp_cwnd_update_after_ecn_echo = sctp_htcp_cwnd_update_after_ecn_echo,
.sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
.sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
},
{
.sctp_set_initial_cc_param = sctp_set_rtcc_initial_cc_param,
.sctp_cwnd_update_after_sack = sctp_cwnd_update_rtcc_after_sack,
.sctp_cwnd_update_exit_pf = sctp_cwnd_update_exit_pf_common,
.sctp_cwnd_update_after_fr = sctp_cwnd_update_after_fr,
.sctp_cwnd_update_after_timeout = sctp_cwnd_update_after_timeout,
.sctp_cwnd_update_after_ecn_echo = sctp_cwnd_update_rtcc_after_ecn_echo,
.sctp_cwnd_update_after_packet_dropped = sctp_cwnd_update_after_packet_dropped,
.sctp_cwnd_update_after_output = sctp_cwnd_update_after_output,
.sctp_cwnd_update_packet_transmitted = sctp_cwnd_update_rtcc_packet_transmitted,
.sctp_cwnd_update_tsn_acknowledged = sctp_cwnd_update_rtcc_tsn_acknowledged,
.sctp_cwnd_new_transmission_begins = sctp_cwnd_new_rtcc_transmission_begins,
.sctp_cwnd_prepare_net_for_sack = sctp_cwnd_prepare_rtcc_net_for_sack,
.sctp_cwnd_socket_option = sctp_cwnd_rtcc_socket_option,
.sctp_rtt_calculated = sctp_rtt_rtcc_calculated
}
};
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