1/*
2 * q_sfq.c		SFQ.
3 *
4 *		This program is free software; you can redistribute it and/or
5 *		modify it under the terms of the GNU General Public License
6 *		as published by the Free Software Foundation; either version
7 *		2 of the License, or (at your option) any later version.
8 *
9 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13#include <stdio.h>
14#include <stdlib.h>
15#include <unistd.h>
16#include <syslog.h>
17#include <fcntl.h>
18#include <sys/socket.h>
19#include <netinet/in.h>
20#include <arpa/inet.h>
21#include <string.h>
22#include <math.h>
23
24#include "utils.h"
25#include "tc_util.h"
26#include "tc_red.h"
27
28static void explain(void)
29{
30	fprintf(stderr, "Usage: ... sfq [ limit NUMBER ] [ perturb SECS ] [ quantum BYTES ]\n");
31	fprintf(stderr, "               [ divisor NUMBER ] [ flows NUMBER] [ depth NUMBER ]\n");
32	fprintf(stderr, "               [ headdrop ]\n");
33	fprintf(stderr, "               [ redflowlimit BYTES ] [ min BYTES ] [ max BYTES ]\n");
34	fprintf(stderr, "               [ avpkt BYTES ] [ burst PACKETS ] [ probability P ]\n");
35	fprintf(stderr, "               [ ecn ] [ harddrop ]\n");
36}
37
38static int sfq_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
39{
40	int ok = 0, red = 0;
41	struct tc_sfq_qopt_v1 opt;
42	unsigned int burst = 0;
43	int wlog;
44	unsigned int avpkt = 1000;
45	double probability = 0.02;
46
47	memset(&opt, 0, sizeof(opt));
48
49	while (argc > 0) {
50		if (strcmp(*argv, "quantum") == 0) {
51			NEXT_ARG();
52			if (get_size(&opt.v0.quantum, *argv)) {
53				fprintf(stderr, "Illegal \"limit\"\n");
54				return -1;
55			}
56			ok++;
57		} else if (strcmp(*argv, "perturb") == 0) {
58			NEXT_ARG();
59			if (get_integer(&opt.v0.perturb_period, *argv, 0)) {
60				fprintf(stderr, "Illegal \"perturb\"\n");
61				return -1;
62			}
63			ok++;
64		} else if (strcmp(*argv, "limit") == 0) {
65			NEXT_ARG();
66			if (get_u32(&opt.v0.limit, *argv, 0)) {
67				fprintf(stderr, "Illegal \"limit\"\n");
68				return -1;
69			}
70			if (opt.v0.limit < 2) {
71				fprintf(stderr, "Illegal \"limit\", must be > 1\n");
72				return -1;
73			}
74			ok++;
75		} else if (strcmp(*argv, "divisor") == 0) {
76			NEXT_ARG();
77			if (get_u32(&opt.v0.divisor, *argv, 0)) {
78				fprintf(stderr, "Illegal \"divisor\"\n");
79				return -1;
80			}
81			ok++;
82		} else if (strcmp(*argv, "flows") == 0) {
83			NEXT_ARG();
84			if (get_u32(&opt.v0.flows, *argv, 0)) {
85				fprintf(stderr, "Illegal \"flows\"\n");
86				return -1;
87			}
88			ok++;
89		} else if (strcmp(*argv, "depth") == 0) {
90			NEXT_ARG();
91			if (get_u32(&opt.depth, *argv, 0)) {
92				fprintf(stderr, "Illegal \"flows\"\n");
93				return -1;
94			}
95			ok++;
96		} else if (strcmp(*argv, "headdrop") == 0) {
97			opt.headdrop = 1;
98			ok++;
99		} else if (strcmp(*argv, "redflowlimit") == 0) {
100			NEXT_ARG();
101			if (get_u32(&opt.limit, *argv, 0)) {
102				fprintf(stderr, "Illegal \"redflowlimit\"\n");
103				return -1;
104			}
105			red++;
106		} else if (strcmp(*argv, "min") == 0) {
107			NEXT_ARG();
108			if (get_u32(&opt.qth_min, *argv, 0)) {
109				fprintf(stderr, "Illegal \"min\"\n");
110				return -1;
111			}
112			red++;
113		} else if (strcmp(*argv, "max") == 0) {
114			NEXT_ARG();
115			if (get_u32(&opt.qth_max, *argv, 0)) {
116				fprintf(stderr, "Illegal \"max\"\n");
117				return -1;
118			}
119			red++;
120		} else if (strcmp(*argv, "burst") == 0) {
121			NEXT_ARG();
122			if (get_unsigned(&burst, *argv, 0)) {
123				fprintf(stderr, "Illegal \"burst\"\n");
124				return -1;
125			}
126			red++;
127		} else if (strcmp(*argv, "avpkt") == 0) {
128			NEXT_ARG();
129			if (get_size(&avpkt, *argv)) {
130				fprintf(stderr, "Illegal \"avpkt\"\n");
131				return -1;
132			}
133			red++;
134		} else if (strcmp(*argv, "probability") == 0) {
135			NEXT_ARG();
136			if (sscanf(*argv, "%lg", &probability) != 1) {
137				fprintf(stderr, "Illegal \"probability\"\n");
138				return -1;
139			}
140			red++;
141		} else if (strcmp(*argv, "ecn") == 0) {
142			opt.flags |= TC_RED_ECN;
143			red++;
144		} else if (strcmp(*argv, "harddrop") == 0) {
145			opt.flags |= TC_RED_HARDDROP;
146			red++;
147		} else if (strcmp(*argv, "help") == 0) {
148			explain();
149			return -1;
150		} else {
151			fprintf(stderr, "What is \"%s\"?\n", *argv);
152			explain();
153			return -1;
154		}
155		argc--; argv++;
156	}
157	if (red) {
158		if (!opt.limit) {
159			fprintf(stderr, "Required parameter (redflowlimit) is missing\n");
160			return -1;
161		}
162		/* Compute default min/max thresholds based on
163		   Sally Floyd's recommendations:
164		   http://www.icir.org/floyd/REDparameters.txt
165		*/
166		if (!opt.qth_max)
167			opt.qth_max = opt.limit / 4;
168		if (!opt.qth_min)
169			opt.qth_min = opt.qth_max / 3;
170		if (!burst)
171			burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
172
173		if (opt.qth_max > opt.limit) {
174			fprintf(stderr, "\"max\" is larger than \"limit\"\n");
175			return -1;
176		}
177
178		if (opt.qth_min >= opt.qth_max) {
179			fprintf(stderr, "\"min\" is not smaller than \"max\"\n");
180			return -1;
181		}
182
183		wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt);
184		if (wlog < 0) {
185			fprintf(stderr, "SFQ: failed to calculate EWMA constant.\n");
186			return -1;
187		}
188		if (wlog >= 10)
189			fprintf(stderr, "SFQ: WARNING. Burst %u seems to be too large.\n", burst);
190		opt.Wlog = wlog;
191
192		wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability);
193		if (wlog < 0) {
194			fprintf(stderr, "SFQ: failed to calculate probability.\n");
195			return -1;
196		}
197		opt.Plog = wlog;
198		opt.max_P = probability * pow(2, 32);
199	}
200
201	if (ok || red)
202		addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
203	return 0;
204}
205
206static int sfq_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
207{
208	struct tc_sfq_qopt *qopt;
209	struct tc_sfq_qopt_v1 *qopt_ext = NULL;
210	SPRINT_BUF(b1);
211	SPRINT_BUF(b2);
212	SPRINT_BUF(b3);
213	if (opt == NULL)
214		return 0;
215
216	if (RTA_PAYLOAD(opt)  < sizeof(*qopt))
217		return -1;
218	if (RTA_PAYLOAD(opt) >= sizeof(*qopt_ext))
219		qopt_ext = RTA_DATA(opt);
220	qopt = RTA_DATA(opt);
221	fprintf(f, "limit %up ", qopt->limit);
222	fprintf(f, "quantum %s ", sprint_size(qopt->quantum, b1));
223	if (qopt_ext && qopt_ext->depth)
224		fprintf(f, "depth %u ", qopt_ext->depth);
225	if (qopt_ext && qopt_ext->headdrop)
226		fprintf(f, "headdrop ");
227
228	if (show_details) {
229		fprintf(f, "flows %u/%u ", qopt->flows, qopt->divisor);
230	}
231	fprintf(f, "divisor %u ", qopt->divisor);
232	if (qopt->perturb_period)
233		fprintf(f, "perturb %dsec ", qopt->perturb_period);
234	if (qopt_ext && qopt_ext->qth_min) {
235		fprintf(f, "\n ewma %u ", qopt_ext->Wlog);
236		fprintf(f, "min %s max %s probability %g ",
237			sprint_size(qopt_ext->qth_min, b2),
238			sprint_size(qopt_ext->qth_max, b3),
239			qopt_ext->max_P / pow(2, 32));
240		if (qopt_ext->flags & TC_RED_ECN)
241			fprintf(f, "ecn ");
242		if (show_stats) {
243			fprintf(f, "\n prob_mark %u prob_mark_head %u prob_drop %u",
244				qopt_ext->stats.prob_mark,
245				qopt_ext->stats.prob_mark_head,
246				qopt_ext->stats.prob_drop);
247			fprintf(f, "\n forced_mark %u forced_mark_head %u forced_drop %u",
248				qopt_ext->stats.forced_mark,
249				qopt_ext->stats.forced_mark_head,
250				qopt_ext->stats.forced_drop);
251		}
252	}
253	return 0;
254}
255
256static int sfq_print_xstats(struct qdisc_util *qu, FILE *f,
257			    struct rtattr *xstats)
258{
259	struct tc_sfq_xstats *st;
260
261	if (xstats == NULL)
262		return 0;
263	if (RTA_PAYLOAD(xstats) < sizeof(*st))
264		return -1;
265	st = RTA_DATA(xstats);
266
267	fprintf(f, " allot %d ", st->allot);
268	fprintf(f, "\n");
269	return 0;
270}
271
272struct qdisc_util sfq_qdisc_util = {
273	.id		= "sfq",
274	.parse_qopt	= sfq_parse_opt,
275	.print_qopt	= sfq_print_opt,
276	.print_xstats	= sfq_print_xstats,
277};
278