1 /*
2 * q_netem.c NETEM.
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: Stephen Hemminger <shemminger@linux-foundation.org>
10 *
11 */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <math.h>
16 #include <ctype.h>
17 #include <unistd.h>
18 #include <syslog.h>
19 #include <fcntl.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
23 #include <string.h>
24 #include <errno.h>
25
26 #include "utils.h"
27 #include "tc_util.h"
28 #include "tc_common.h"
29
explain(void)30 static void explain(void)
31 {
32 fprintf(stderr,
33 "Usage: ... netem [ limit PACKETS ] \n" \
34 " [ delay TIME [ JITTER [CORRELATION]]]\n" \
35 " [ distribution {uniform|normal|pareto|paretonormal} ]\n" \
36 " [ corrupt PERCENT [CORRELATION]] \n" \
37 " [ duplicate PERCENT [CORRELATION]]\n" \
38 " [ loss random PERCENT [CORRELATION]]\n" \
39 " [ loss state P13 [P31 [P32 [P23 P14]]]\n" \
40 " [ loss gemodel PERCENT [R [1-H [1-K]]]\n" \
41 " [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n" \
42 " [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n");
43 }
44
explain1(const char * arg)45 static void explain1(const char *arg)
46 {
47 fprintf(stderr, "Illegal \"%s\"\n", arg);
48 }
49
50 /* Upper bound on size of distribution
51 * really (TCA_BUF_MAX - other headers) / sizeof (__s16)
52 */
53 #define MAX_DIST (16*1024)
54
55 static const double max_percent_value = 0xffffffff;
56
57 /* scaled value used to percent of maximum. */
set_percent(__u32 * percent,double per)58 static void set_percent(__u32 *percent, double per)
59 {
60 *percent = (unsigned) rint(per * max_percent_value);
61 }
62
63
64 /* Parse either a fraction '.3' or percent '30%
65 * return: 0 = ok, -1 = error, 1 = out of range
66 */
parse_percent(double * val,const char * str)67 static int parse_percent(double *val, const char *str)
68 {
69 char *p;
70
71 *val = strtod(str, &p) / 100.;
72 if (*p && strcmp(p, "%") )
73 return -1;
74
75 return 0;
76 }
77
get_percent(__u32 * percent,const char * str)78 static int get_percent(__u32 *percent, const char *str)
79 {
80 double per;
81
82 if (parse_percent(&per, str))
83 return -1;
84
85 set_percent(percent, per);
86 return 0;
87 }
88
print_percent(char * buf,int len,__u32 per)89 void print_percent(char *buf, int len, __u32 per)
90 {
91 snprintf(buf, len, "%g%%", 100. * (double) per / max_percent_value);
92 }
93
sprint_percent(__u32 per,char * buf)94 char * sprint_percent(__u32 per, char *buf)
95 {
96 print_percent(buf, SPRINT_BSIZE-1, per);
97 return buf;
98 }
99
100 /*
101 * Simplistic file parser for distrbution data.
102 * Format is:
103 * # comment line(s)
104 * data0 data1 ...
105 */
get_distribution(const char * type,__s16 * data,int maxdata)106 static int get_distribution(const char *type, __s16 *data, int maxdata)
107 {
108 FILE *f;
109 int n;
110 long x;
111 size_t len;
112 char *line = NULL;
113 char name[128];
114
115 snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
116 if ((f = fopen(name, "r")) == NULL) {
117 fprintf(stderr, "No distribution data for %s (%s: %s)\n",
118 type, name, strerror(errno));
119 return -1;
120 }
121
122 n = 0;
123 while (getline(&line, &len, f) != -1) {
124 char *p, *endp;
125 if (*line == '\n' || *line == '#')
126 continue;
127
128 for (p = line; ; p = endp) {
129 x = strtol(p, &endp, 0);
130 if (endp == p)
131 break;
132
133 if (n >= maxdata) {
134 fprintf(stderr, "%s: too much data\n",
135 name);
136 n = -1;
137 goto error;
138 }
139 data[n++] = x;
140 }
141 }
142 error:
143 free(line);
144 fclose(f);
145 return n;
146 }
147
148 #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isdigit(argv[1][0]))
149
150 /* Adjust for the fact that psched_ticks aren't always usecs
151 (based on kernel PSCHED_CLOCK configuration */
get_ticks(__u32 * ticks,const char * str)152 static int get_ticks(__u32 *ticks, const char *str)
153 {
154 unsigned t;
155
156 if(get_time(&t, str))
157 return -1;
158
159 if (tc_core_time2big(t)) {
160 fprintf(stderr, "Illegal %u time (too large)\n", t);
161 return -1;
162 }
163
164 *ticks = tc_core_time2tick(t);
165 return 0;
166 }
167
netem_parse_opt(struct qdisc_util * qu,int argc,char ** argv,struct nlmsghdr * n)168 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
169 struct nlmsghdr *n)
170 {
171 int dist_size = 0;
172 struct rtattr *tail;
173 struct tc_netem_qopt opt = { .limit = 1000 };
174 struct tc_netem_corr cor;
175 struct tc_netem_reorder reorder;
176 struct tc_netem_corrupt corrupt;
177 struct tc_netem_gimodel gimodel;
178 struct tc_netem_gemodel gemodel;
179 struct tc_netem_rate rate;
180 __s16 *dist_data = NULL;
181 __u16 loss_type = NETEM_LOSS_UNSPEC;
182 int present[__TCA_NETEM_MAX];
183
184 memset(&cor, 0, sizeof(cor));
185 memset(&reorder, 0, sizeof(reorder));
186 memset(&corrupt, 0, sizeof(corrupt));
187 memset(&rate, 0, sizeof(rate));
188 memset(present, 0, sizeof(present));
189
190 for( ; argc > 0; --argc, ++argv) {
191 if (matches(*argv, "limit") == 0) {
192 NEXT_ARG();
193 if (get_size(&opt.limit, *argv)) {
194 explain1("limit");
195 return -1;
196 }
197 } else if (matches(*argv, "latency") == 0 ||
198 matches(*argv, "delay") == 0) {
199 NEXT_ARG();
200 if (get_ticks(&opt.latency, *argv)) {
201 explain1("latency");
202 return -1;
203 }
204
205 if (NEXT_IS_NUMBER()) {
206 NEXT_ARG();
207 if (get_ticks(&opt.jitter, *argv)) {
208 explain1("latency");
209 return -1;
210 }
211
212 if (NEXT_IS_NUMBER()) {
213 NEXT_ARG();
214 ++present[TCA_NETEM_CORR];
215 if (get_percent(&cor.delay_corr, *argv)) {
216 explain1("latency");
217 return -1;
218 }
219 }
220 }
221 } else if (matches(*argv, "loss") == 0 ||
222 matches(*argv, "drop") == 0) {
223 if (opt.loss > 0 || loss_type != NETEM_LOSS_UNSPEC) {
224 explain1("duplicate loss argument\n");
225 return -1;
226 }
227
228 NEXT_ARG();
229 /* Old (deprecated) random loss model syntax */
230 if (isdigit(argv[0][0]))
231 goto random_loss_model;
232
233 if (!strcmp(*argv, "random")) {
234 NEXT_ARG();
235 random_loss_model:
236 if (get_percent(&opt.loss, *argv)) {
237 explain1("loss percent");
238 return -1;
239 }
240 if (NEXT_IS_NUMBER()) {
241 NEXT_ARG();
242 ++present[TCA_NETEM_CORR];
243 if (get_percent(&cor.loss_corr, *argv)) {
244 explain1("loss correllation");
245 return -1;
246 }
247 }
248 } else if (!strcmp(*argv, "state")) {
249 double p13;
250
251 NEXT_ARG();
252 if (parse_percent(&p13, *argv)) {
253 explain1("loss p13");
254 return -1;
255 }
256
257 /* set defaults */
258 set_percent(&gimodel.p13, p13);
259 set_percent(&gimodel.p31, 1. - p13);
260 set_percent(&gimodel.p32, 0);
261 set_percent(&gimodel.p23, 1.);
262 loss_type = NETEM_LOSS_GI;
263
264 if (!NEXT_IS_NUMBER())
265 continue;
266 NEXT_ARG();
267 if (get_percent(&gimodel.p31, *argv)) {
268 explain1("loss p31");
269 return -1;
270 }
271
272 if (!NEXT_IS_NUMBER())
273 continue;
274 NEXT_ARG();
275 if (get_percent(&gimodel.p32, *argv)) {
276 explain1("loss p32");
277 return -1;
278 }
279
280 if (!NEXT_IS_NUMBER())
281 continue;
282 NEXT_ARG();
283 if (get_percent(&gimodel.p23, *argv)) {
284 explain1("loss p23");
285 return -1;
286 }
287
288 } else if (!strcmp(*argv, "gemodel")) {
289 NEXT_ARG();
290 if (get_percent(&gemodel.p, *argv)) {
291 explain1("loss gemodel p");
292 return -1;
293 }
294
295 /* set defaults */
296 set_percent(&gemodel.r, 1.);
297 set_percent(&gemodel.h, 0);
298 set_percent(&gemodel.k1, 1.);
299 loss_type = NETEM_LOSS_GE;
300
301 if (!NEXT_IS_NUMBER())
302 continue;
303 NEXT_ARG();
304 if (get_percent(&gemodel.r, *argv)) {
305 explain1("loss gemodel r");
306 return -1;
307 }
308
309 if (!NEXT_IS_NUMBER())
310 continue;
311 NEXT_ARG();
312 if (get_percent(&gemodel.h, *argv)) {
313 explain1("loss gemodel h");
314 return -1;
315 }
316
317 if (!NEXT_IS_NUMBER())
318 continue;
319 NEXT_ARG();
320 if (get_percent(&gemodel.k1, *argv)) {
321 explain1("loss gemodel k");
322 return -1;
323 }
324 } else {
325 fprintf(stderr, "Unknown loss parameter: %s\n",
326 *argv);
327 return -1;
328 }
329 } else if (matches(*argv, "reorder") == 0) {
330 NEXT_ARG();
331 present[TCA_NETEM_REORDER] = 1;
332 if (get_percent(&reorder.probability, *argv)) {
333 explain1("reorder");
334 return -1;
335 }
336 if (NEXT_IS_NUMBER()) {
337 NEXT_ARG();
338 ++present[TCA_NETEM_CORR];
339 if (get_percent(&reorder.correlation, *argv)) {
340 explain1("reorder");
341 return -1;
342 }
343 }
344 } else if (matches(*argv, "corrupt") == 0) {
345 NEXT_ARG();
346 present[TCA_NETEM_CORRUPT] = 1;
347 if (get_percent(&corrupt.probability, *argv)) {
348 explain1("corrupt");
349 return -1;
350 }
351 if (NEXT_IS_NUMBER()) {
352 NEXT_ARG();
353 ++present[TCA_NETEM_CORR];
354 if (get_percent(&corrupt.correlation, *argv)) {
355 explain1("corrupt");
356 return -1;
357 }
358 }
359 } else if (matches(*argv, "gap") == 0) {
360 NEXT_ARG();
361 if (get_u32(&opt.gap, *argv, 0)) {
362 explain1("gap");
363 return -1;
364 }
365 } else if (matches(*argv, "duplicate") == 0) {
366 NEXT_ARG();
367 if (get_percent(&opt.duplicate, *argv)) {
368 explain1("duplicate");
369 return -1;
370 }
371 if (NEXT_IS_NUMBER()) {
372 NEXT_ARG();
373 if (get_percent(&cor.dup_corr, *argv)) {
374 explain1("duplicate");
375 return -1;
376 }
377 }
378 } else if (matches(*argv, "distribution") == 0) {
379 NEXT_ARG();
380 dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
381 dist_size = get_distribution(*argv, dist_data, MAX_DIST);
382 if (dist_size <= 0) {
383 free(dist_data);
384 return -1;
385 }
386 } else if (matches(*argv, "rate") == 0) {
387 ++present[TCA_NETEM_RATE];
388 NEXT_ARG();
389 if (get_rate(&rate.rate, *argv)) {
390 explain1("rate");
391 return -1;
392 }
393 if (NEXT_IS_NUMBER()) {
394 NEXT_ARG();
395 if (get_s32(&rate.packet_overhead, *argv, 0)) {
396 explain1("rate");
397 return -1;
398 }
399 }
400 if (NEXT_IS_NUMBER()) {
401 NEXT_ARG();
402 if (get_u32(&rate.cell_size, *argv, 0)) {
403 explain1("rate");
404 return -1;
405 }
406 }
407 if (NEXT_IS_NUMBER()) {
408 NEXT_ARG();
409 if (get_s32(&rate.cell_overhead, *argv, 0)) {
410 explain1("rate");
411 return -1;
412 }
413 }
414 } else if (strcmp(*argv, "help") == 0) {
415 explain();
416 return -1;
417 } else {
418 fprintf(stderr, "What is \"%s\"?\n", *argv);
419 explain();
420 return -1;
421 }
422 }
423
424 tail = NLMSG_TAIL(n);
425
426 if (reorder.probability) {
427 if (opt.latency == 0) {
428 fprintf(stderr, "reordering not possible without specifying some delay\n");
429 explain();
430 return -1;
431 }
432 if (opt.gap == 0)
433 opt.gap = 1;
434 } else if (opt.gap > 0) {
435 fprintf(stderr, "gap specified without reorder probability\n");
436 explain();
437 return -1;
438 }
439
440 if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
441 fprintf(stderr, "distribution specified but no latency and jitter values\n");
442 explain();
443 return -1;
444 }
445
446 if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
447 return -1;
448
449 if (present[TCA_NETEM_CORR] &&
450 addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
451 return -1;
452
453 if (present[TCA_NETEM_REORDER] &&
454 addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
455 return -1;
456
457 if (present[TCA_NETEM_CORRUPT] &&
458 addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
459 return -1;
460
461 if (loss_type != NETEM_LOSS_UNSPEC) {
462 struct rtattr *start;
463
464 start = addattr_nest(n, 1024, TCA_NETEM_LOSS | NLA_F_NESTED);
465 if (loss_type == NETEM_LOSS_GI) {
466 if (addattr_l(n, 1024, NETEM_LOSS_GI,
467 &gimodel, sizeof(gimodel)) < 0)
468 return -1;
469 } else if (loss_type == NETEM_LOSS_GE) {
470 if (addattr_l(n, 1024, NETEM_LOSS_GE,
471 &gemodel, sizeof(gemodel)) < 0)
472 return -1;
473 } else {
474 fprintf(stderr, "loss in the weeds!\n");
475 return -1;
476 }
477
478 addattr_nest_end(n, start);
479 }
480
481 if (present[TCA_NETEM_RATE] &&
482 addattr_l(n, 1024, TCA_NETEM_RATE, &rate, sizeof(rate)) < 0)
483 return -1;
484
485 if (dist_data) {
486 if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
487 TCA_NETEM_DELAY_DIST,
488 dist_data, dist_size * sizeof(dist_data[0])) < 0)
489 return -1;
490 free(dist_data);
491 }
492 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
493 return 0;
494 }
495
netem_print_opt(struct qdisc_util * qu,FILE * f,struct rtattr * opt)496 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
497 {
498 const struct tc_netem_corr *cor = NULL;
499 const struct tc_netem_reorder *reorder = NULL;
500 const struct tc_netem_corrupt *corrupt = NULL;
501 const struct tc_netem_gimodel *gimodel = NULL;
502 const struct tc_netem_gemodel *gemodel = NULL;
503 struct tc_netem_qopt qopt;
504 const struct tc_netem_rate *rate = NULL;
505 int len = RTA_PAYLOAD(opt) - sizeof(qopt);
506 SPRINT_BUF(b1);
507
508 if (opt == NULL)
509 return 0;
510
511 if (len < 0) {
512 fprintf(stderr, "options size error\n");
513 return -1;
514 }
515 memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
516
517 if (len > 0) {
518 struct rtattr *tb[TCA_NETEM_MAX+1];
519 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
520 len);
521
522 if (tb[TCA_NETEM_CORR]) {
523 if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
524 return -1;
525 cor = RTA_DATA(tb[TCA_NETEM_CORR]);
526 }
527 if (tb[TCA_NETEM_REORDER]) {
528 if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
529 return -1;
530 reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
531 }
532 if (tb[TCA_NETEM_CORRUPT]) {
533 if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
534 return -1;
535 corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
536 }
537 if (tb[TCA_NETEM_LOSS]) {
538 struct rtattr *lb[NETEM_LOSS_MAX + 1];
539
540 parse_rtattr_nested(lb, NETEM_LOSS_MAX, tb[TCA_NETEM_LOSS]);
541 if (lb[NETEM_LOSS_GI])
542 gemodel = RTA_DATA(lb[NETEM_LOSS_GI]);
543 if (lb[NETEM_LOSS_GE])
544 gemodel = RTA_DATA(lb[NETEM_LOSS_GE]);
545 }
546 if (tb[TCA_NETEM_RATE]) {
547 if (RTA_PAYLOAD(tb[TCA_NETEM_RATE]) < sizeof(*rate))
548 return -1;
549 rate = RTA_DATA(tb[TCA_NETEM_RATE]);
550 }
551 }
552
553 fprintf(f, "limit %d", qopt.limit);
554
555 if (qopt.latency) {
556 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
557
558 if (qopt.jitter) {
559 fprintf(f, " %s", sprint_ticks(qopt.jitter, b1));
560 if (cor && cor->delay_corr)
561 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
562 }
563 }
564
565 if (qopt.loss) {
566 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
567 if (cor && cor->loss_corr)
568 fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
569 }
570
571 if (gimodel) {
572 fprintf(f, " loss state p13 %s", sprint_percent(gimodel->p13, b1));
573 fprintf(f, " p31 %s", sprint_percent(gimodel->p31, b1));
574 fprintf(f, " p32 %s", sprint_percent(gimodel->p32, b1));
575 fprintf(f, " p23 %s", sprint_percent(gimodel->p23, b1));
576 fprintf(f, " p14 %s", sprint_percent(gimodel->p14, b1));
577 }
578
579 if (gemodel) {
580 fprintf(f, "loss gemodel p %s",
581 sprint_percent(gemodel->p, b1));
582 fprintf(f, " r %s", sprint_percent(gemodel->r, b1));
583 fprintf(f, " 1-h %s", sprint_percent(gemodel->h, b1));
584 fprintf(f, " 1-k %s", sprint_percent(gemodel->k1, b1));
585 }
586
587 if (qopt.duplicate) {
588 fprintf(f, " duplicate %s",
589 sprint_percent(qopt.duplicate, b1));
590 if (cor && cor->dup_corr)
591 fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
592 }
593
594 if (reorder && reorder->probability) {
595 fprintf(f, " reorder %s",
596 sprint_percent(reorder->probability, b1));
597 if (reorder->correlation)
598 fprintf(f, " %s",
599 sprint_percent(reorder->correlation, b1));
600 }
601
602 if (corrupt && corrupt->probability) {
603 fprintf(f, " corrupt %s",
604 sprint_percent(corrupt->probability, b1));
605 if (corrupt->correlation)
606 fprintf(f, " %s",
607 sprint_percent(corrupt->correlation, b1));
608 }
609
610 if (rate && rate->rate) {
611 fprintf(f, " rate %s", sprint_rate(rate->rate, b1));
612 if (rate->packet_overhead)
613 fprintf(f, " packetoverhead %d", rate->packet_overhead);
614 if (rate->cell_size)
615 fprintf(f, " cellsize %u", rate->cell_size);
616 if (rate->cell_overhead)
617 fprintf(f, " celloverhead %d", rate->cell_overhead);
618 }
619
620 if (qopt.gap)
621 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
622
623 return 0;
624 }
625
626 struct qdisc_util netem_qdisc_util = {
627 .id = "netem",
628 .parse_qopt = netem_parse_opt,
629 .print_qopt = netem_print_opt,
630 };
631
632