blob: 2855f05186d87a24fb85aad79f8a7b42ee3859b9 [file] [log] [blame]
/*
* NewReno congestion control algorithm.
*
* This file contains definitions for QUIC congestion control.
*
* Copyright 2019 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <haproxy/quic_cc.h>
#include <haproxy/trace.h>
#include <haproxy/xprt_quic.h>
#define TRACE_SOURCE &trace_quic
static int quic_cc_nr_init(struct quic_cc *cc)
{
struct quic_path *path;
path = container_of(cc, struct quic_path, cc);
cc->algo_state.nr.state = QUIC_CC_ST_SS;
cc->algo_state.nr.cwnd = path->cwnd;
cc->algo_state.nr.ssthresh = QUIC_CC_INFINITE_SSTHESH;
cc->algo_state.nr.recovery_start_time = 0;
return 1;
}
/* Slow start callback. */
static void quic_cc_nr_ss_cb(struct quic_cc *cc, struct quic_cc_event *ev)
{
struct quic_path *path;
TRACE_ENTER(QUIC_EV_CONN_CC, cc->qc->conn, ev);
path = container_of(cc, struct quic_path, cc);
switch (ev->type) {
case QUIC_CC_EVT_ACK:
path->in_flight -= ev->ack.acked;
/* Do not increase the congestion window in recovery period. */
if (ev->ack.time_sent <= cc->algo_state.nr.recovery_start_time)
return;
cc->algo_state.nr.cwnd += ev->ack.acked;
/* Exit to congestion avoidance if slow start threshold is reached. */
if (cc->algo_state.nr.cwnd > cc->algo_state.nr.ssthresh)
cc->algo_state.nr.state = QUIC_CC_ST_CA;
path->cwnd = cc->algo_state.nr.cwnd;
break;
case QUIC_CC_EVT_LOSS:
path->in_flight -= ev->loss.lost_bytes;
cc->algo_state.nr.cwnd = QUIC_MAX(cc->algo_state.nr.cwnd >> 1, path->min_cwnd);
path->cwnd = cc->algo_state.nr.ssthresh = cc->algo_state.nr.cwnd;
/* Exit to congestion avoidance. */
cc->algo_state.nr.state = QUIC_CC_ST_CA;
break;
case QUIC_CC_EVT_ECN_CE:
/* XXX TO DO XXX */
break;
}
TRACE_LEAVE(QUIC_EV_CONN_CC, cc->qc->conn,, cc);
}
/* Congestion avoidance callback. */
static void quic_cc_nr_ca_cb(struct quic_cc *cc, struct quic_cc_event *ev)
{
struct quic_path *path;
TRACE_ENTER(QUIC_EV_CONN_CC, cc->qc->conn);
path = container_of(cc, struct quic_path, cc);
switch (ev->type) {
case QUIC_CC_EVT_ACK:
path->in_flight -= ev->ack.acked;
/* Do not increase the congestion window in recovery period. */
if (ev->ack.time_sent <= cc->algo_state.nr.recovery_start_time)
goto out;
/* Increasing the congestion window by 1 maximum packet size by
* congestion window.
*/
cc->algo_state.nr.cwnd +=
path->mtu * QUIC_MAX(1ULL, (unsigned long long)ev->ack.acked / cc->algo_state.nr.cwnd);
path->cwnd = cc->algo_state.nr.cwnd;
break;
case QUIC_CC_EVT_LOSS:
path->in_flight -= ev->loss.lost_bytes;
if (ev->loss.newest_time_sent > cc->algo_state.nr.recovery_start_time) {
cc->algo_state.nr.recovery_start_time = ev->loss.now_ms;
cc->algo_state.nr.cwnd = QUIC_MAX(cc->algo_state.nr.cwnd >> 1, path->min_cwnd);
cc->algo_state.nr.ssthresh = cc->algo_state.nr.cwnd;
}
if (quic_loss_persistent_congestion(&path->loss,
ev->loss.period,
ev->loss.now_ms,
ev->loss.max_ack_delay)) {
cc->algo_state.nr.cwnd = path->min_cwnd;
/* Re-entering slow start state. */
cc->algo_state.nr.state = QUIC_CC_ST_SS;
}
path->cwnd = cc->algo_state.nr.cwnd;
break;
case QUIC_CC_EVT_ECN_CE:
/* XXX TO DO XXX */
break;
}
out:
TRACE_LEAVE(QUIC_EV_CONN_CC, cc->qc->conn);
}
static void quic_cc_nr_state_trace(struct buffer *buf, const struct quic_cc *cc)
{
chunk_appendf(buf, " state=%s cwnd=%llu ssthresh=%ld recovery_start_time=%llu",
quic_cc_state_str(cc->algo_state.nr.state),
(unsigned long long)cc->algo_state.nr.cwnd,
(long)cc->algo_state.nr.ssthresh,
(unsigned long long)cc->algo_state.nr.recovery_start_time);
}
static void (*quic_cc_nr_state_cbs[])(struct quic_cc *cc,
struct quic_cc_event *ev) = {
[QUIC_CC_ST_SS] = quic_cc_nr_ss_cb,
[QUIC_CC_ST_CA] = quic_cc_nr_ca_cb,
};
static void quic_cc_nr_event(struct quic_cc *cc, struct quic_cc_event *ev)
{
return quic_cc_nr_state_cbs[cc->algo_state.nr.state](cc, ev);
}
struct quic_cc_algo quic_cc_algo_nr = {
.type = QUIC_CC_ALGO_TP_NEWRENO,
.init = quic_cc_nr_init,
.event = quic_cc_nr_event,
.state_trace = quic_cc_nr_state_trace,
};