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freebsd-dev/sys/netinet/sctp_cc_functions.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags. 
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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 - 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 - 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 - 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 - 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 - 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 - 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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