256 lines
7.4 KiB
C
256 lines
7.4 KiB
C
/*-
|
|
* Copyright (c) 2009-2010
|
|
* Swinburne University of Technology, Melbourne, Australia
|
|
* Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
|
|
* Copyright (c) 2010-2011 The FreeBSD Foundation
|
|
* All rights reserved.
|
|
*
|
|
* This software was developed at the Centre for Advanced Internet
|
|
* Architectures, Swinburne University of Technology, by David Hayes and
|
|
* Lawrence Stewart, made possible in part by a grant from the Cisco University
|
|
* Research Program Fund at Community Foundation Silicon Valley.
|
|
*
|
|
* Portions of this software were developed at the Centre for Advanced Internet
|
|
* Architectures, Swinburne University of Technology, Melbourne, Australia by
|
|
* David Hayes under sponsorship from the FreeBSD Foundation.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
*/
|
|
|
|
/*
|
|
* An implementation of the Hamilton Institute's delay-based congestion control
|
|
* algorithm for FreeBSD, based on "A strategy for fair coexistence of loss and
|
|
* delay-based congestion control algorithms," by L. Budzisz, R. Stanojevic, R.
|
|
* Shorten, and F. Baker, IEEE Commun. Lett., vol. 13, no. 7, pp. 555--557, Jul.
|
|
* 2009.
|
|
*
|
|
* Originally released as part of the NewTCP research project at Swinburne
|
|
* University of Technology's Centre for Advanced Internet Architectures,
|
|
* Melbourne, Australia, which was made possible in part by a grant from the
|
|
* Cisco University Research Program Fund at Community Foundation Silicon
|
|
* Valley. More details are available at:
|
|
* http://caia.swin.edu.au/urp/newtcp/
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/khelp.h>
|
|
#include <sys/limits.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/module.h>
|
|
#include <sys/queue.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/systm.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/vnet.h>
|
|
|
|
#include <netinet/cc.h>
|
|
#include <netinet/tcp_seq.h>
|
|
#include <netinet/tcp_timer.h>
|
|
#include <netinet/tcp_var.h>
|
|
|
|
#include <netinet/cc/cc_module.h>
|
|
|
|
#include <netinet/khelp/h_ertt.h>
|
|
|
|
#define CAST_PTR_INT(X) (*((int*)(X)))
|
|
|
|
/* Largest possible number returned by random(). */
|
|
#define RANDOM_MAX INT_MAX
|
|
|
|
static void hd_ack_received(struct cc_var *ccv, uint16_t ack_type);
|
|
static int hd_mod_init(void);
|
|
|
|
static int ertt_id;
|
|
|
|
static VNET_DEFINE(uint32_t, hd_qthresh) = 20;
|
|
static VNET_DEFINE(uint32_t, hd_qmin) = 5;
|
|
static VNET_DEFINE(uint32_t, hd_pmax) = 5;
|
|
#define V_hd_qthresh VNET(hd_qthresh)
|
|
#define V_hd_qmin VNET(hd_qmin)
|
|
#define V_hd_pmax VNET(hd_pmax)
|
|
|
|
struct cc_algo hd_cc_algo = {
|
|
.name = "hd",
|
|
.ack_received = hd_ack_received,
|
|
.mod_init = hd_mod_init
|
|
};
|
|
|
|
/*
|
|
* Hamilton backoff function. Returns 1 if we should backoff or 0 otherwise.
|
|
*/
|
|
static __inline int
|
|
should_backoff(int qdly, int maxqdly)
|
|
{
|
|
unsigned long p;
|
|
|
|
if (qdly < V_hd_qthresh) {
|
|
p = (((RANDOM_MAX / 100) * V_hd_pmax) /
|
|
(V_hd_qthresh - V_hd_qmin)) * (qdly - V_hd_qmin);
|
|
} else {
|
|
if (qdly > V_hd_qthresh)
|
|
p = (((RANDOM_MAX / 100) * V_hd_pmax) /
|
|
(maxqdly - V_hd_qthresh)) * (maxqdly - qdly);
|
|
else
|
|
p = (RANDOM_MAX / 100) * V_hd_pmax;
|
|
}
|
|
|
|
return (random() < p);
|
|
}
|
|
|
|
/*
|
|
* If the ack type is CC_ACK, and the inferred queueing delay is greater than
|
|
* the Qmin threshold, cwnd is reduced probabilistically. When backing off due
|
|
* to delay, HD behaves like NewReno when an ECN signal is received. HD behaves
|
|
* as NewReno in all other circumstances.
|
|
*/
|
|
static void
|
|
hd_ack_received(struct cc_var *ccv, uint16_t ack_type)
|
|
{
|
|
struct ertt *e_t;
|
|
int qdly;
|
|
|
|
if (ack_type == CC_ACK) {
|
|
e_t = khelp_get_osd(CCV(ccv, osd), ertt_id);
|
|
|
|
if (e_t->rtt && e_t->minrtt && V_hd_qthresh > 0) {
|
|
qdly = e_t->rtt - e_t->minrtt;
|
|
|
|
if (qdly > V_hd_qmin &&
|
|
!IN_RECOVERY(CCV(ccv, t_flags))) {
|
|
/* Probabilistic backoff of cwnd. */
|
|
if (should_backoff(qdly,
|
|
e_t->maxrtt - e_t->minrtt)) {
|
|
/*
|
|
* Update cwnd and ssthresh update to
|
|
* half cwnd and behave like an ECN (ie
|
|
* not a packet loss).
|
|
*/
|
|
newreno_cc_algo.cong_signal(ccv,
|
|
CC_ECN);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
newreno_cc_algo.ack_received(ccv, ack_type); /* As for NewReno. */
|
|
}
|
|
|
|
static int
|
|
hd_mod_init(void)
|
|
{
|
|
|
|
ertt_id = khelp_get_id("ertt");
|
|
if (ertt_id <= 0) {
|
|
printf("%s: h_ertt module not found\n", __func__);
|
|
return (ENOENT);
|
|
}
|
|
|
|
hd_cc_algo.after_idle = newreno_cc_algo.after_idle;
|
|
hd_cc_algo.cong_signal = newreno_cc_algo.cong_signal;
|
|
hd_cc_algo.post_recovery = newreno_cc_algo.post_recovery;
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
hd_pmax_handler(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
uint32_t new;
|
|
|
|
new = V_hd_pmax;
|
|
error = sysctl_handle_int(oidp, &new, 0, req);
|
|
if (error == 0 && req->newptr != NULL) {
|
|
if (CAST_PTR_INT(req->newptr) == 0 ||
|
|
CAST_PTR_INT(req->newptr) > 100)
|
|
error = EINVAL;
|
|
else
|
|
V_hd_pmax = new;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
hd_qmin_handler(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
uint32_t new;
|
|
|
|
new = V_hd_qmin;
|
|
error = sysctl_handle_int(oidp, &new, 0, req);
|
|
if (error == 0 && req->newptr != NULL) {
|
|
if (CAST_PTR_INT(req->newptr) > V_hd_qthresh)
|
|
error = EINVAL;
|
|
else
|
|
V_hd_qmin = new;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
hd_qthresh_handler(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
uint32_t new;
|
|
|
|
new = V_hd_qthresh;
|
|
error = sysctl_handle_int(oidp, &new, 0, req);
|
|
if (error == 0 && req->newptr != NULL) {
|
|
if (CAST_PTR_INT(req->newptr) < 1 ||
|
|
CAST_PTR_INT(req->newptr) < V_hd_qmin)
|
|
error = EINVAL;
|
|
else
|
|
V_hd_qthresh = new;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_DECL(_net_inet_tcp_cc_hd);
|
|
SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, hd, CTLFLAG_RW, NULL,
|
|
"Hamilton delay-based congestion control related settings");
|
|
|
|
SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_threshold,
|
|
CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qthresh), 20,
|
|
&hd_qthresh_handler, "IU", "queueing congestion threshold (qth) in ticks");
|
|
|
|
SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, pmax,
|
|
CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_pmax), 5,
|
|
&hd_pmax_handler, "IU",
|
|
"per packet maximum backoff probability as a percentage");
|
|
|
|
SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_min,
|
|
CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qmin), 5,
|
|
&hd_qmin_handler, "IU", "minimum queueing delay threshold (qmin) in ticks");
|
|
|
|
DECLARE_CC_MODULE(hd, &hd_cc_algo);
|
|
MODULE_DEPEND(hd, ertt, 1, 1, 1);
|