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@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
  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
  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. */
  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  */
  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
  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
  89 void print_percent(char *buf, int len, __u32 per)
  90 {
  91         snprintf(buf, len, "%g%%", 100. * (double) per / max_percent_value);
  92 }
  93
  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  */
 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 */
 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
 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                 }
 430                 if (opt.gap == 0)
 431                         opt.gap = 1;
 432         } else if (opt.gap > 0) {
 433                 fprintf(stderr, "gap specified without reorder probability\n");
 434                 explain();
 435                 return -1;
 436         }
 437
 438         if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
 439                 fprintf(stderr, "distribution specified but no latency and jitter values\n");
 440                 explain();
 441                 return -1;
 442         }
 443
 444         if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
 445                 return -1;
 446
 447         if (present[TCA_NETEM_CORR] &&
 448             addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
 449                         return -1;
 450
 451         if (present[TCA_NETEM_REORDER] &&
 452             addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
 453                 return -1;
 454
 455         if (present[TCA_NETEM_CORRUPT] &&
 456             addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
 457                 return -1;
 458
 459         if (loss_type != NETEM_LOSS_UNSPEC) {
 460                 struct rtattr *start;
 461
 462                 start = addattr_nest(n, 1024, TCA_NETEM_LOSS | NLA_F_NESTED);
 463                 if (loss_type == NETEM_LOSS_GI) {
 464                         if (addattr_l(n, 1024, NETEM_LOSS_GI,
 465                                       &gimodel, sizeof(gimodel)) < 0)
 466                             return -1;
 467                 } else if (loss_type == NETEM_LOSS_GE) {
 468                         if (addattr_l(n, 1024, NETEM_LOSS_GE,
 469                                       &gemodel, sizeof(gemodel)) < 0)
 470                             return -1;
 471                 } else {
 472                         fprintf(stderr, "loss in the weeds!\n");
 473                         return -1;
 474                 }
 475
 476                 addattr_nest_end(n, start);
 477         }
 478
 479         if (present[TCA_NETEM_RATE] &&
 480             addattr_l(n, 1024, TCA_NETEM_RATE, &rate, sizeof(rate)) < 0)
 481                 return -1;
 482
 483         if (dist_data) {
 484                 if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
 485                               TCA_NETEM_DELAY_DIST,
 486                               dist_data, dist_size * sizeof(dist_data[0])) < 0)
 487                         return -1;
 488                 free(dist_data);
 489         }
 490         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 491         return 0;
 492 }
 493
 494 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 495 {
 496         const struct tc_netem_corr *cor = NULL;
 497         const struct tc_netem_reorder *reorder = NULL;
 498         const struct tc_netem_corrupt *corrupt = NULL;
 499         const struct tc_netem_gimodel *gimodel = NULL;
 500         const struct tc_netem_gemodel *gemodel = NULL;
 501         struct tc_netem_qopt qopt;
 502         const struct tc_netem_rate *rate = NULL;
 503         int len = RTA_PAYLOAD(opt) - sizeof(qopt);
 504         SPRINT_BUF(b1);
 505
 506         if (opt == NULL)
 507                 return 0;
 508
 509         if (len < 0) {
 510                 fprintf(stderr, "options size error\n");
 511                 return -1;
 512         }
 513         memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
 514
 515         if (len > 0) {
 516                 struct rtattr *tb[TCA_NETEM_MAX+1];
 517                 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
 518                              len);
 519
 520                 if (tb[TCA_NETEM_CORR]) {
 521                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
 522                                 return -1;
 523                         cor = RTA_DATA(tb[TCA_NETEM_CORR]);
 524                 }
 525                 if (tb[TCA_NETEM_REORDER]) {
 526                         if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
 527                                 return -1;
 528                         reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
 529                 }
 530                 if (tb[TCA_NETEM_CORRUPT]) {
 531                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
 532                                 return -1;
 533                         corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
 534                 }
 535                 if (tb[TCA_NETEM_LOSS]) {
 536                         struct rtattr *lb[NETEM_LOSS_MAX + 1];
 537
 538                         parse_rtattr_nested(lb, NETEM_LOSS_MAX, tb[TCA_NETEM_LOSS]);
 539                         if (lb[NETEM_LOSS_GI])
 540                                 gemodel = RTA_DATA(lb[NETEM_LOSS_GI]);
 541                         if (lb[NETEM_LOSS_GE])
 542                                 gemodel = RTA_DATA(lb[NETEM_LOSS_GE]);
 543                 }
 544                 if (tb[TCA_NETEM_RATE]) {
 545                         if (RTA_PAYLOAD(tb[TCA_NETEM_RATE]) < sizeof(*rate))
 546                                 return -1;
 547                         rate = RTA_DATA(tb[TCA_NETEM_RATE]);
 548                 }
 549         }
 550
 551         fprintf(f, "limit %d", qopt.limit);
 552
 553         if (qopt.latency) {
 554                 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
 555
 556                 if (qopt.jitter) {
 557                         fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
 558                         if (cor && cor->delay_corr)
 559                                 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
 560                 }
 561         }
 562
 563         if (qopt.loss) {
 564                 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
 565                 if (cor && cor->loss_corr)
 566                         fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
 567         }
 568
 569         if (gimodel) {
 570                 fprintf(f, " loss state p13 %s", sprint_percent(gimodel->p13, b1));
 571                 fprintf(f, " p31 %s", sprint_percent(gimodel->p31, b1));
 572                 fprintf(f, " p32 %s", sprint_percent(gimodel->p32, b1));
 573                 fprintf(f, " p23 %s", sprint_percent(gimodel->p23, b1));
 574                 fprintf(f, " p14 %s", sprint_percent(gimodel->p14, b1));
 575         }
 576
 577         if (gemodel) {
 578                 fprintf(f, "loss gemodel p %s",
 579                         sprint_percent(gemodel->p, b1));
 580                 fprintf(f, " r %s", sprint_percent(gemodel->r, b1));
 581                 fprintf(f, " 1-h %s", sprint_percent(gemodel->h, b1));
 582                 fprintf(f, " 1-k %s", sprint_percent(gemodel->k1, b1));
 583         }
 584
 585         if (qopt.duplicate) {
 586                 fprintf(f, " duplicate %s",
 587                         sprint_percent(qopt.duplicate, b1));
 588                 if (cor && cor->dup_corr)
 589                         fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
 590         }
 591
 592         if (reorder && reorder->probability) {
 593                 fprintf(f, " reorder %s",
 594                         sprint_percent(reorder->probability, b1));
 595                 if (reorder->correlation)
 596                         fprintf(f, " %s",
 597                                 sprint_percent(reorder->correlation, b1));
 598         }
 599
 600         if (corrupt && corrupt->probability) {
 601                 fprintf(f, " corrupt %s",
 602                         sprint_percent(corrupt->probability, b1));
 603                 if (corrupt->correlation)
 604                         fprintf(f, " %s",
 605                                 sprint_percent(corrupt->correlation, b1));
 606         }
 607
 608         if (rate && rate->rate) {
 609                 fprintf(f, " rate %s", sprint_rate(rate->rate, b1));
 610                 if (rate->packet_overhead)
 611                         fprintf(f, " packetoverhead %d", rate->packet_overhead);
 612                 if (rate->cell_size)
 613                         fprintf(f, " cellsize %u", rate->cell_size);
 614                 if (rate->cell_overhead)
 615                         fprintf(f, " celloverhead %d", rate->cell_overhead);
 616         }
 617
 618         if (qopt.gap)
 619                 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
 620
 621         return 0;
 622 }
 623
 624 struct qdisc_util netem_qdisc_util = {
 625         .id             = "netem",
 626         .parse_qopt     = netem_parse_opt,
 627         .print_qopt     = netem_print_opt,
 628 };
 629