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@osdl.org>
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 <errno.h>
23
24 #include "utils.h"
25 #include "tc_util.h"
26 #include "tc_common.h"
27
explain(void)28 static void explain(void)
29 {
30 fprintf(stderr,
31 "Usage: ... netem [ limit PACKETS ] \n" \
32 " [ delay TIME [ JITTER [CORRELATION]]]\n" \
33 " [ distribution {uniform|normal|pareto|paretonormal} ]\n" \
34 " [ drop PERCENT [CORRELATION]] \n" \
35 " [ corrupt PERCENT [CORRELATION]] \n" \
36 " [ duplicate PERCENT [CORRELATION]]\n" \
37 " [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n");
38 }
39
explain1(const char * arg)40 static void explain1(const char *arg)
41 {
42 fprintf(stderr, "Illegal \"%s\"\n", arg);
43 }
44
45 /* Upper bound on size of distribution
46 * really (TCA_BUF_MAX - other headers) / sizeof (__s16)
47 */
48 #define MAX_DIST (16*1024)
49
50 /*
51 * Simplistic file parser for distrbution data.
52 * Format is:
53 * # comment line(s)
54 * data0 data1 ...
55 */
get_distribution(const char * type,__s16 * data,int maxdata)56 static int get_distribution(const char *type, __s16 *data, int maxdata)
57 {
58 FILE *f;
59 int n;
60 long x;
61 size_t len;
62 char *line = NULL;
63 char name[128];
64
65 snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
66 if ((f = fopen(name, "r")) == NULL) {
67 fprintf(stderr, "No distribution data for %s (%s: %s)\n",
68 type, name, strerror(errno));
69 return -1;
70 }
71
72 n = 0;
73 while (getline(&line, &len, f) != -1) {
74 char *p, *endp;
75 if (*line == '\n' || *line == '#')
76 continue;
77
78 for (p = line; ; p = endp) {
79 x = strtol(p, &endp, 0);
80 if (endp == p)
81 break;
82
83 if (n >= maxdata) {
84 fprintf(stderr, "%s: too much data\n",
85 name);
86 n = -1;
87 goto error;
88 }
89 data[n++] = x;
90 }
91 }
92 error:
93 free(line);
94 fclose(f);
95 return n;
96 }
97
isnumber(const char * arg)98 static int isnumber(const char *arg)
99 {
100 char *p;
101
102 return strtod(arg, &p) != 0 || p != arg;
103 }
104
105 #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1]))
106
107 /* Adjust for the fact that psched_ticks aren't always usecs
108 (based on kernel PSCHED_CLOCK configuration */
get_ticks(__u32 * ticks,const char * str)109 static int get_ticks(__u32 *ticks, const char *str)
110 {
111 unsigned t;
112
113 if(get_time(&t, str))
114 return -1;
115
116 if (tc_core_time2big(t)) {
117 fprintf(stderr, "Illegal %u time (too large)\n", t);
118 return -1;
119 }
120
121 *ticks = tc_core_time2tick(t);
122 return 0;
123 }
124
netem_parse_opt(struct qdisc_util * qu,int argc,char ** argv,struct nlmsghdr * n)125 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
126 struct nlmsghdr *n)
127 {
128 size_t dist_size = 0;
129 struct rtattr *tail;
130 struct tc_netem_qopt opt;
131 struct tc_netem_corr cor;
132 struct tc_netem_reorder reorder;
133 struct tc_netem_corrupt corrupt;
134 __s16 *dist_data = NULL;
135 int present[__TCA_NETEM_MAX];
136
137 memset(&opt, 0, sizeof(opt));
138 opt.limit = 1000;
139 memset(&cor, 0, sizeof(cor));
140 memset(&reorder, 0, sizeof(reorder));
141 memset(&corrupt, 0, sizeof(corrupt));
142 memset(present, 0, sizeof(present));
143
144 while (argc > 0) {
145 if (matches(*argv, "limit") == 0) {
146 NEXT_ARG();
147 if (get_size(&opt.limit, *argv)) {
148 explain1("limit");
149 return -1;
150 }
151 } else if (matches(*argv, "latency") == 0 ||
152 matches(*argv, "delay") == 0) {
153 NEXT_ARG();
154 if (get_ticks(&opt.latency, *argv)) {
155 explain1("latency");
156 return -1;
157 }
158
159 if (NEXT_IS_NUMBER()) {
160 NEXT_ARG();
161 if (get_ticks(&opt.jitter, *argv)) {
162 explain1("latency");
163 return -1;
164 }
165
166 if (NEXT_IS_NUMBER()) {
167 NEXT_ARG();
168 ++present[TCA_NETEM_CORR];
169 if (get_percent(&cor.delay_corr, *argv)) {
170 explain1("latency");
171 return -1;
172 }
173 }
174 }
175 } else if (matches(*argv, "loss") == 0 ||
176 matches(*argv, "drop") == 0) {
177 NEXT_ARG();
178 if (get_percent(&opt.loss, *argv)) {
179 explain1("loss");
180 return -1;
181 }
182 if (NEXT_IS_NUMBER()) {
183 NEXT_ARG();
184 ++present[TCA_NETEM_CORR];
185 if (get_percent(&cor.loss_corr, *argv)) {
186 explain1("loss");
187 return -1;
188 }
189 }
190 } else if (matches(*argv, "reorder") == 0) {
191 NEXT_ARG();
192 present[TCA_NETEM_REORDER] = 1;
193 if (get_percent(&reorder.probability, *argv)) {
194 explain1("reorder");
195 return -1;
196 }
197 if (NEXT_IS_NUMBER()) {
198 NEXT_ARG();
199 ++present[TCA_NETEM_CORR];
200 if (get_percent(&reorder.correlation, *argv)) {
201 explain1("reorder");
202 return -1;
203 }
204 }
205 } else if (matches(*argv, "corrupt") == 0) {
206 NEXT_ARG();
207 present[TCA_NETEM_CORRUPT] = 1;
208 if (get_percent(&corrupt.probability, *argv)) {
209 explain1("corrupt");
210 return -1;
211 }
212 if (NEXT_IS_NUMBER()) {
213 NEXT_ARG();
214 ++present[TCA_NETEM_CORR];
215 if (get_percent(&corrupt.correlation, *argv)) {
216 explain1("corrupt");
217 return -1;
218 }
219 }
220 } else if (matches(*argv, "gap") == 0) {
221 NEXT_ARG();
222 if (get_u32(&opt.gap, *argv, 0)) {
223 explain1("gap");
224 return -1;
225 }
226 } else if (matches(*argv, "duplicate") == 0) {
227 NEXT_ARG();
228 if (get_percent(&opt.duplicate, *argv)) {
229 explain1("duplicate");
230 return -1;
231 }
232 if (NEXT_IS_NUMBER()) {
233 NEXT_ARG();
234 if (get_percent(&cor.dup_corr, *argv)) {
235 explain1("duplicate");
236 return -1;
237 }
238 }
239 } else if (matches(*argv, "distribution") == 0) {
240 NEXT_ARG();
241 dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
242 dist_size = get_distribution(*argv, dist_data, MAX_DIST);
243 if (dist_size <= 0) {
244 free(dist_data);
245 return -1;
246 }
247 } else if (strcmp(*argv, "help") == 0) {
248 explain();
249 return -1;
250 } else {
251 fprintf(stderr, "What is \"%s\"?\n", *argv);
252 explain();
253 return -1;
254 }
255 argc--; argv++;
256 }
257
258 tail = NLMSG_TAIL(n);
259
260 if (reorder.probability) {
261 if (opt.latency == 0) {
262 fprintf(stderr, "reordering not possible without specifying some delay\n");
263 }
264 if (opt.gap == 0)
265 opt.gap = 1;
266 } else if (opt.gap > 0) {
267 fprintf(stderr, "gap specified without reorder probability\n");
268 explain();
269 return -1;
270 }
271
272 if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
273 fprintf(stderr, "distribution specified but no latency and jitter values\n");
274 explain();
275 return -1;
276 }
277
278 if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
279 return -1;
280
281 if (present[TCA_NETEM_CORR] &&
282 addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
283 return -1;
284
285 if (present[TCA_NETEM_REORDER] &&
286 addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
287 return -1;
288
289 if (present[TCA_NETEM_CORRUPT] &&
290 addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
291 return -1;
292
293 if (dist_data) {
294 if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
295 TCA_NETEM_DELAY_DIST,
296 dist_data, dist_size * sizeof(dist_data[0])) < 0)
297 return -1;
298 free(dist_data);
299 }
300 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
301 return 0;
302 }
303
netem_print_opt(struct qdisc_util * qu,FILE * f,struct rtattr * opt)304 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
305 {
306 const struct tc_netem_corr *cor = NULL;
307 const struct tc_netem_reorder *reorder = NULL;
308 const struct tc_netem_corrupt *corrupt = NULL;
309 struct tc_netem_qopt qopt;
310 int len = RTA_PAYLOAD(opt) - sizeof(qopt);
311 SPRINT_BUF(b1);
312
313 if (opt == NULL)
314 return 0;
315
316 if (len < 0) {
317 fprintf(stderr, "options size error\n");
318 return -1;
319 }
320 memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
321
322 if (len > 0) {
323 struct rtattr *tb[TCA_NETEM_MAX+1];
324 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
325 len);
326
327 if (tb[TCA_NETEM_CORR]) {
328 if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
329 return -1;
330 cor = RTA_DATA(tb[TCA_NETEM_CORR]);
331 }
332 if (tb[TCA_NETEM_REORDER]) {
333 if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
334 return -1;
335 reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
336 }
337 if (tb[TCA_NETEM_CORRUPT]) {
338 if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
339 return -1;
340 corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
341 }
342 }
343
344 fprintf(f, "limit %d", qopt.limit);
345
346 if (qopt.latency) {
347 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
348
349 if (qopt.jitter) {
350 fprintf(f, " %s", sprint_ticks(qopt.jitter, b1));
351 if (cor && cor->delay_corr)
352 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
353 }
354 }
355
356 if (qopt.loss) {
357 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
358 if (cor && cor->loss_corr)
359 fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
360 }
361
362 if (qopt.duplicate) {
363 fprintf(f, " duplicate %s",
364 sprint_percent(qopt.duplicate, b1));
365 if (cor && cor->dup_corr)
366 fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
367 }
368
369 if (reorder && reorder->probability) {
370 fprintf(f, " reorder %s",
371 sprint_percent(reorder->probability, b1));
372 if (reorder->correlation)
373 fprintf(f, " %s",
374 sprint_percent(reorder->correlation, b1));
375 }
376
377 if (corrupt && corrupt->probability) {
378 fprintf(f, " corrupt %s",
379 sprint_percent(corrupt->probability, b1));
380 if (corrupt->correlation)
381 fprintf(f, " %s",
382 sprint_percent(corrupt->correlation, b1));
383 }
384
385 if (qopt.gap)
386 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
387
388 return 0;
389 }
390
391 struct qdisc_util netem_qdisc_util = {
392 .id = "netem",
393 .parse_qopt = netem_parse_opt,
394 .print_qopt = netem_print_opt,
395 };
396
397