tc/q_netem.c

   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
  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
  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  */
  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
  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 */
 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
 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
 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