1/*-
2 * Copyright (c) 2009-2010
3 * Swinburne University of Technology, Melbourne, Australia
4 * Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010-2011 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * This software was developed at the Centre for Advanced Internet
9 * Architectures, Swinburne University of Technology, by David Hayes and
10 * Lawrence Stewart, made possible in part by a grant from the Cisco University
11 * Research Program Fund at Community Foundation Silicon Valley.
12 *
13 * Portions of this software were developed at the Centre for Advanced Internet
14 * Architectures, Swinburne University of Technology, Melbourne, Australia by
15 * David Hayes under sponsorship from the FreeBSD Foundation.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39/*
40 * An implementation of the Hamilton Institute's delay-based congestion control
41 * algorithm for FreeBSD, based on "A strategy for fair coexistence of loss and
42 * delay-based congestion control algorithms," by L. Budzisz, R. Stanojevic, R.
43 * Shorten, and F. Baker, IEEE Commun. Lett., vol. 13, no. 7, pp. 555--557, Jul.
44 * 2009.
45 *
46 * Originally released as part of the NewTCP research project at Swinburne
47 * University of Technology's Centre for Advanced Internet Architectures,
48 * Melbourne, Australia, which was made possible in part by a grant from the
49 * Cisco University Research Program Fund at Community Foundation Silicon
50 * Valley. More details are available at:
51 * http://caia.swin.edu.au/urp/newtcp/
52 */
53
54#include <sys/cdefs.h>
| 1/*-
2 * Copyright (c) 2009-2010
3 * Swinburne University of Technology, Melbourne, Australia
4 * Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010-2011 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * This software was developed at the Centre for Advanced Internet
9 * Architectures, Swinburne University of Technology, by David Hayes and
10 * Lawrence Stewart, made possible in part by a grant from the Cisco University
11 * Research Program Fund at Community Foundation Silicon Valley.
12 *
13 * Portions of this software were developed at the Centre for Advanced Internet
14 * Architectures, Swinburne University of Technology, Melbourne, Australia by
15 * David Hayes under sponsorship from the FreeBSD Foundation.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39/*
40 * An implementation of the Hamilton Institute's delay-based congestion control
41 * algorithm for FreeBSD, based on "A strategy for fair coexistence of loss and
42 * delay-based congestion control algorithms," by L. Budzisz, R. Stanojevic, R.
43 * Shorten, and F. Baker, IEEE Commun. Lett., vol. 13, no. 7, pp. 555--557, Jul.
44 * 2009.
45 *
46 * Originally released as part of the NewTCP research project at Swinburne
47 * University of Technology's Centre for Advanced Internet Architectures,
48 * Melbourne, Australia, which was made possible in part by a grant from the
49 * Cisco University Research Program Fund at Community Foundation Silicon
50 * Valley. More details are available at:
51 * http://caia.swin.edu.au/urp/newtcp/
52 */
53
54#include <sys/cdefs.h>
|
76#include <netinet/cc/cc_module.h>
77
78#include <netinet/khelp/h_ertt.h>
79
80#define CAST_PTR_INT(X) (*((int*)(X)))
81
82/* Largest possible number returned by random(). */
83#define RANDOM_MAX INT_MAX
84
85static void hd_ack_received(struct cc_var *ccv, uint16_t ack_type);
86static int hd_mod_init(void);
87
88static int ertt_id;
89
90static VNET_DEFINE(uint32_t, hd_qthresh) = 20;
91static VNET_DEFINE(uint32_t, hd_qmin) = 5;
92static VNET_DEFINE(uint32_t, hd_pmax) = 5;
93#define V_hd_qthresh VNET(hd_qthresh)
94#define V_hd_qmin VNET(hd_qmin)
95#define V_hd_pmax VNET(hd_pmax)
96
97struct cc_algo hd_cc_algo = {
98 .name = "hd",
99 .ack_received = hd_ack_received,
100 .mod_init = hd_mod_init
101};
102
103/*
104 * Hamilton backoff function. Returns 1 if we should backoff or 0 otherwise.
105 */
106static __inline int
107should_backoff(int qdly, int maxqdly)
108{
109 unsigned long p;
110
111 if (qdly < V_hd_qthresh) {
112 p = (((RANDOM_MAX / 100) * V_hd_pmax) /
113 (V_hd_qthresh - V_hd_qmin)) * (qdly - V_hd_qmin);
114 } else {
115 if (qdly > V_hd_qthresh)
116 p = (((RANDOM_MAX / 100) * V_hd_pmax) /
117 (maxqdly - V_hd_qthresh)) * (maxqdly - qdly);
118 else
119 p = (RANDOM_MAX / 100) * V_hd_pmax;
120 }
121
122 return (random() < p);
123}
124
125/*
126 * If the ack type is CC_ACK, and the inferred queueing delay is greater than
127 * the Qmin threshold, cwnd is reduced probabilistically. When backing off due
128 * to delay, HD behaves like NewReno when an ECN signal is received. HD behaves
129 * as NewReno in all other circumstances.
130 */
131static void
132hd_ack_received(struct cc_var *ccv, uint16_t ack_type)
133{
134 struct ertt *e_t;
135 int qdly;
136
137 if (ack_type == CC_ACK) {
138 e_t = khelp_get_osd(CCV(ccv, osd), ertt_id);
139
140 if (e_t->rtt && e_t->minrtt && V_hd_qthresh > 0) {
141 qdly = e_t->rtt - e_t->minrtt;
142
143 if (qdly > V_hd_qmin &&
144 !IN_RECOVERY(CCV(ccv, t_flags))) {
145 /* Probabilistic backoff of cwnd. */
146 if (should_backoff(qdly,
147 e_t->maxrtt - e_t->minrtt)) {
148 /*
149 * Update cwnd and ssthresh update to
150 * half cwnd and behave like an ECN (ie
151 * not a packet loss).
152 */
153 newreno_cc_algo.cong_signal(ccv,
154 CC_ECN);
155 return;
156 }
157 }
158 }
159 }
160 newreno_cc_algo.ack_received(ccv, ack_type); /* As for NewReno. */
161}
162
163static int
164hd_mod_init(void)
165{
166
167 ertt_id = khelp_get_id("ertt");
168 if (ertt_id <= 0) {
169 printf("%s: h_ertt module not found\n", __func__);
170 return (ENOENT);
171 }
172
173 hd_cc_algo.after_idle = newreno_cc_algo.after_idle;
174 hd_cc_algo.cong_signal = newreno_cc_algo.cong_signal;
175 hd_cc_algo.post_recovery = newreno_cc_algo.post_recovery;
176
177 return (0);
178}
179
180static int
181hd_pmax_handler(SYSCTL_HANDLER_ARGS)
182{
183 int error;
184 uint32_t new;
185
186 new = V_hd_pmax;
187 error = sysctl_handle_int(oidp, &new, 0, req);
188 if (error == 0 && req->newptr != NULL) {
189 if (CAST_PTR_INT(req->newptr) == 0 ||
190 CAST_PTR_INT(req->newptr) > 100)
191 error = EINVAL;
192 else
193 V_hd_pmax = new;
194 }
195
196 return (error);
197}
198
199static int
200hd_qmin_handler(SYSCTL_HANDLER_ARGS)
201{
202 int error;
203 uint32_t new;
204
205 new = V_hd_qmin;
206 error = sysctl_handle_int(oidp, &new, 0, req);
207 if (error == 0 && req->newptr != NULL) {
208 if (CAST_PTR_INT(req->newptr) > V_hd_qthresh)
209 error = EINVAL;
210 else
211 V_hd_qmin = new;
212 }
213
214 return (error);
215}
216
217static int
218hd_qthresh_handler(SYSCTL_HANDLER_ARGS)
219{
220 int error;
221 uint32_t new;
222
223 new = V_hd_qthresh;
224 error = sysctl_handle_int(oidp, &new, 0, req);
225 if (error == 0 && req->newptr != NULL) {
226 if (CAST_PTR_INT(req->newptr) < 1 ||
227 CAST_PTR_INT(req->newptr) < V_hd_qmin)
228 error = EINVAL;
229 else
230 V_hd_qthresh = new;
231 }
232
233 return (error);
234}
235
236SYSCTL_DECL(_net_inet_tcp_cc_hd);
237SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, hd, CTLFLAG_RW, NULL,
238 "Hamilton delay-based congestion control related settings");
239
240SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_threshold,
241 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qthresh), 20,
242 &hd_qthresh_handler, "IU", "queueing congestion threshold (qth) in ticks");
243
244SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, pmax,
245 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_pmax), 5,
246 &hd_pmax_handler, "IU",
247 "per packet maximum backoff probability as a percentage");
248
249SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_min,
250 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qmin), 5,
251 &hd_qmin_handler, "IU", "minimum queueing delay threshold (qmin) in ticks");
252
253DECLARE_CC_MODULE(hd, &hd_cc_algo);
254MODULE_DEPEND(hd, ertt, 1, 1, 1);
| 76#include <netinet/cc/cc_module.h>
77
78#include <netinet/khelp/h_ertt.h>
79
80#define CAST_PTR_INT(X) (*((int*)(X)))
81
82/* Largest possible number returned by random(). */
83#define RANDOM_MAX INT_MAX
84
85static void hd_ack_received(struct cc_var *ccv, uint16_t ack_type);
86static int hd_mod_init(void);
87
88static int ertt_id;
89
90static VNET_DEFINE(uint32_t, hd_qthresh) = 20;
91static VNET_DEFINE(uint32_t, hd_qmin) = 5;
92static VNET_DEFINE(uint32_t, hd_pmax) = 5;
93#define V_hd_qthresh VNET(hd_qthresh)
94#define V_hd_qmin VNET(hd_qmin)
95#define V_hd_pmax VNET(hd_pmax)
96
97struct cc_algo hd_cc_algo = {
98 .name = "hd",
99 .ack_received = hd_ack_received,
100 .mod_init = hd_mod_init
101};
102
103/*
104 * Hamilton backoff function. Returns 1 if we should backoff or 0 otherwise.
105 */
106static __inline int
107should_backoff(int qdly, int maxqdly)
108{
109 unsigned long p;
110
111 if (qdly < V_hd_qthresh) {
112 p = (((RANDOM_MAX / 100) * V_hd_pmax) /
113 (V_hd_qthresh - V_hd_qmin)) * (qdly - V_hd_qmin);
114 } else {
115 if (qdly > V_hd_qthresh)
116 p = (((RANDOM_MAX / 100) * V_hd_pmax) /
117 (maxqdly - V_hd_qthresh)) * (maxqdly - qdly);
118 else
119 p = (RANDOM_MAX / 100) * V_hd_pmax;
120 }
121
122 return (random() < p);
123}
124
125/*
126 * If the ack type is CC_ACK, and the inferred queueing delay is greater than
127 * the Qmin threshold, cwnd is reduced probabilistically. When backing off due
128 * to delay, HD behaves like NewReno when an ECN signal is received. HD behaves
129 * as NewReno in all other circumstances.
130 */
131static void
132hd_ack_received(struct cc_var *ccv, uint16_t ack_type)
133{
134 struct ertt *e_t;
135 int qdly;
136
137 if (ack_type == CC_ACK) {
138 e_t = khelp_get_osd(CCV(ccv, osd), ertt_id);
139
140 if (e_t->rtt && e_t->minrtt && V_hd_qthresh > 0) {
141 qdly = e_t->rtt - e_t->minrtt;
142
143 if (qdly > V_hd_qmin &&
144 !IN_RECOVERY(CCV(ccv, t_flags))) {
145 /* Probabilistic backoff of cwnd. */
146 if (should_backoff(qdly,
147 e_t->maxrtt - e_t->minrtt)) {
148 /*
149 * Update cwnd and ssthresh update to
150 * half cwnd and behave like an ECN (ie
151 * not a packet loss).
152 */
153 newreno_cc_algo.cong_signal(ccv,
154 CC_ECN);
155 return;
156 }
157 }
158 }
159 }
160 newreno_cc_algo.ack_received(ccv, ack_type); /* As for NewReno. */
161}
162
163static int
164hd_mod_init(void)
165{
166
167 ertt_id = khelp_get_id("ertt");
168 if (ertt_id <= 0) {
169 printf("%s: h_ertt module not found\n", __func__);
170 return (ENOENT);
171 }
172
173 hd_cc_algo.after_idle = newreno_cc_algo.after_idle;
174 hd_cc_algo.cong_signal = newreno_cc_algo.cong_signal;
175 hd_cc_algo.post_recovery = newreno_cc_algo.post_recovery;
176
177 return (0);
178}
179
180static int
181hd_pmax_handler(SYSCTL_HANDLER_ARGS)
182{
183 int error;
184 uint32_t new;
185
186 new = V_hd_pmax;
187 error = sysctl_handle_int(oidp, &new, 0, req);
188 if (error == 0 && req->newptr != NULL) {
189 if (CAST_PTR_INT(req->newptr) == 0 ||
190 CAST_PTR_INT(req->newptr) > 100)
191 error = EINVAL;
192 else
193 V_hd_pmax = new;
194 }
195
196 return (error);
197}
198
199static int
200hd_qmin_handler(SYSCTL_HANDLER_ARGS)
201{
202 int error;
203 uint32_t new;
204
205 new = V_hd_qmin;
206 error = sysctl_handle_int(oidp, &new, 0, req);
207 if (error == 0 && req->newptr != NULL) {
208 if (CAST_PTR_INT(req->newptr) > V_hd_qthresh)
209 error = EINVAL;
210 else
211 V_hd_qmin = new;
212 }
213
214 return (error);
215}
216
217static int
218hd_qthresh_handler(SYSCTL_HANDLER_ARGS)
219{
220 int error;
221 uint32_t new;
222
223 new = V_hd_qthresh;
224 error = sysctl_handle_int(oidp, &new, 0, req);
225 if (error == 0 && req->newptr != NULL) {
226 if (CAST_PTR_INT(req->newptr) < 1 ||
227 CAST_PTR_INT(req->newptr) < V_hd_qmin)
228 error = EINVAL;
229 else
230 V_hd_qthresh = new;
231 }
232
233 return (error);
234}
235
236SYSCTL_DECL(_net_inet_tcp_cc_hd);
237SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, hd, CTLFLAG_RW, NULL,
238 "Hamilton delay-based congestion control related settings");
239
240SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_threshold,
241 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qthresh), 20,
242 &hd_qthresh_handler, "IU", "queueing congestion threshold (qth) in ticks");
243
244SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, pmax,
245 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_pmax), 5,
246 &hd_pmax_handler, "IU",
247 "per packet maximum backoff probability as a percentage");
248
249SYSCTL_PROC(_net_inet_tcp_cc_hd, OID_AUTO, queue_min,
250 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(hd_qmin), 5,
251 &hd_qmin_handler, "IU", "minimum queueing delay threshold (qmin) in ticks");
252
253DECLARE_CC_MODULE(hd, &hd_cc_algo);
254MODULE_DEPEND(hd, ertt, 1, 1, 1);
|