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 
explain(void)28 static 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 
sfq_parse_opt(struct qdisc_util * qu,int argc,char ** argv,struct nlmsghdr * n)38 static 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 
sfq_print_opt(struct qdisc_util * qu,FILE * f,struct rtattr * opt)206 static 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 
sfq_print_xstats(struct qdisc_util * qu,FILE * f,struct rtattr * xstats)256 static 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 
272 struct 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