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