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 "                 [ ecn ]\n" \
  42 "                 [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n" \
  43 "                 [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n");
  44 }
  45
  46 static void explain1(const char *arg)
  47 {
  48         fprintf(stderr, "Illegal \"%s\"\n", arg);
  49 }
  50
  51 /* Upper bound on size of distribution
  52  *  really (TCA_BUF_MAX - other headers) / sizeof (__s16)
  53  */
  54 #define MAX_DIST        (16*1024)
  55
  56 static const double max_percent_value = 0xffffffff;
  57
  58 /* scaled value used to percent of maximum. */
  59 static void set_percent(__u32 *percent, double per)
  60 {
  61         *percent = (unsigned) rint(per * max_percent_value);
  62 }
  63
  64
  65 /* Parse either a fraction '.3' or percent '30%
  66  * return: 0 = ok, -1 = error, 1 = out of range
  67  */
  68 static int parse_percent(double *val, const char *str)
  69 {
  70         char *p;
  71
  72         *val = strtod(str, &p) / 100.;
  73         if (*p && strcmp(p, "%") )
  74                 return -1;
  75
  76         return 0;
  77 }
  78
  79 static int get_percent(__u32 *percent, const char *str)
  80 {
  81         double per;
  82
  83         if (parse_percent(&per, str))
  84                 return -1;
  85
  86         set_percent(percent, per);
  87         return 0;
  88 }
  89
  90 void print_percent(char *buf, int len, __u32 per)
  91 {
  92         snprintf(buf, len, "%g%%", 100. * (double) per / max_percent_value);
  93 }
  94
  95 char * sprint_percent(__u32 per, char *buf)
  96 {
  97         print_percent(buf, SPRINT_BSIZE-1, per);
  98         return buf;
  99 }
 100
 101 /*
 102  * Simplistic file parser for distrbution data.
 103  * Format is:
 104  *      # comment line(s)
 105  *      data0 data1 ...
 106  */
 107 static int get_distribution(const char *type, __s16 *data, int maxdata)
 108 {
 109         FILE *f;
 110         int n;
 111         long x;
 112         size_t len;
 113         char *line = NULL;
 114         char name[128];
 115
 116         snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
 117         if ((f = fopen(name, "r")) == NULL) {
 118                 fprintf(stderr, "No distribution data for %s (%s: %s)\n",
 119                         type, name, strerror(errno));
 120                 return -1;
 121         }
 122
 123         n = 0;
 124         while (getline(&line, &len, f) != -1) {
 125                 char *p, *endp;
 126                 if (*line == '\n' || *line == '#')
 127                         continue;
 128
 129                 for (p = line; ; p = endp) {
 130                         x = strtol(p, &endp, 0);
 131                         if (endp == p)
 132                                 break;
 133
 134                         if (n >= maxdata) {
 135                                 fprintf(stderr, "%s: too much data\n",
 136                                         name);
 137                                 n = -1;
 138                                 goto error;
 139                         }
 140                         data[n++] = x;
 141                 }
 142         }
 143  error:
 144         free(line);
 145         fclose(f);
 146         return n;
 147 }
 148
 149 #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isdigit(argv[1][0]))
 150
 151 /* Adjust for the fact that psched_ticks aren't always usecs
 152    (based on kernel PSCHED_CLOCK configuration */
 153 static int get_ticks(__u32 *ticks, const char *str)
 154 {
 155         unsigned t;
 156
 157         if(get_time(&t, str))
 158                 return -1;
 159
 160         if (tc_core_time2big(t)) {
 161                 fprintf(stderr, "Illegal %u time (too large)\n", t);
 162                 return -1;
 163         }
 164
 165         *ticks = tc_core_time2tick(t);
 166         return 0;
 167 }
 168
 169 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 170                            struct nlmsghdr *n)
 171 {
 172         int dist_size = 0;
 173         struct rtattr *tail;
 174         struct tc_netem_qopt opt = { .limit = 1000 };
 175         struct tc_netem_corr cor;
 176         struct tc_netem_reorder reorder;
 177         struct tc_netem_corrupt corrupt;
 178         struct tc_netem_gimodel gimodel;
 179         struct tc_netem_gemodel gemodel;
 180         struct tc_netem_rate rate;
 181         __s16 *dist_data = NULL;
 182         __u16 loss_type = NETEM_LOSS_UNSPEC;
 183         int present[__TCA_NETEM_MAX];
 184
 185         memset(&cor, 0, sizeof(cor));
 186         memset(&reorder, 0, sizeof(reorder));
 187         memset(&corrupt, 0, sizeof(corrupt));
 188         memset(&rate, 0, sizeof(rate));
 189         memset(present, 0, sizeof(present));
 190
 191         for( ; argc > 0; --argc, ++argv) {
 192                 if (matches(*argv, "limit") == 0) {
 193                         NEXT_ARG();
 194                         if (get_size(&opt.limit, *argv)) {
 195                                 explain1("limit");
 196                                 return -1;
 197                         }
 198                 } else if (matches(*argv, "latency") == 0 ||
 199                            matches(*argv, "delay") == 0) {
 200                         NEXT_ARG();
 201                         if (get_ticks(&opt.latency, *argv)) {
 202                                 explain1("latency");
 203                                 return -1;
 204                         }
 205
 206                         if (NEXT_IS_NUMBER()) {
 207                                 NEXT_ARG();
 208                                 if (get_ticks(&opt.jitter, *argv)) {
 209                                         explain1("latency");
 210                                         return -1;
 211                                 }
 212
 213                                 if (NEXT_IS_NUMBER()) {
 214                                         NEXT_ARG();
 215                                         ++present[TCA_NETEM_CORR];
 216                                         if (get_percent(&cor.delay_corr, *argv)) {
 217                                                 explain1("latency");
 218                                                 return -1;
 219                                         }
 220                                 }
 221                         }
 222                 } else if (matches(*argv, "loss") == 0 ||
 223                            matches(*argv, "drop") == 0) {
 224                         if (opt.loss > 0 || loss_type != NETEM_LOSS_UNSPEC) {
 225                                 explain1("duplicate loss argument\n");
 226                                 return -1;
 227                         }
 228
 229                         NEXT_ARG();
 230                         /* Old (deprecated) random loss model syntax */
 231                         if (isdigit(argv[0][0]))
 232                                 goto random_loss_model;
 233
 234                         if (!strcmp(*argv, "random")) {
 235                                 NEXT_ARG();
 236         random_loss_model:
 237                                 if (get_percent(&opt.loss, *argv)) {
 238                                         explain1("loss percent");
 239                                         return -1;
 240                                 }
 241                                 if (NEXT_IS_NUMBER()) {
 242                                         NEXT_ARG();
 243                                         ++present[TCA_NETEM_CORR];
 244                                         if (get_percent(&cor.loss_corr, *argv)) {
 245                                                 explain1("loss correllation");
 246                                                 return -1;
 247                                         }
 248                                 }
 249                         } else if (!strcmp(*argv, "state")) {
 250                                 double p13;
 251
 252                                 NEXT_ARG();
 253                                 if (parse_percent(&p13, *argv)) {
 254                                         explain1("loss p13");
 255                                         return -1;
 256                                 }
 257
 258                                 /* set defaults */
 259                                 set_percent(&gimodel.p13, p13);
 260                                 set_percent(&gimodel.p31, 1. - p13);
 261                                 set_percent(&gimodel.p32, 0);
 262                                 set_percent(&gimodel.p23, 1.);
 263                                 loss_type = NETEM_LOSS_GI;
 264
 265                                 if (!NEXT_IS_NUMBER())
 266                                         continue;
 267                                 NEXT_ARG();
 268                                 if (get_percent(&gimodel.p31, *argv)) {
 269                                         explain1("loss p31");
 270                                         return -1;
 271                                 }
 272
 273                                 if (!NEXT_IS_NUMBER())
 274                                         continue;
 275                                 NEXT_ARG();
 276                                 if (get_percent(&gimodel.p32, *argv)) {
 277                                         explain1("loss p32");
 278                                         return -1;
 279                                 }
 280
 281                                 if (!NEXT_IS_NUMBER())
 282                                         continue;
 283                                 NEXT_ARG();
 284                                 if (get_percent(&gimodel.p23, *argv)) {
 285                                         explain1("loss p23");
 286                                         return -1;
 287                                 }
 288
 289                         } else if (!strcmp(*argv, "gemodel")) {
 290                                 NEXT_ARG();
 291                                 if (get_percent(&gemodel.p, *argv)) {
 292                                         explain1("loss gemodel p");
 293                                         return -1;
 294                                 }
 295
 296                                 /* set defaults */
 297                                 set_percent(&gemodel.r, 1.);
 298                                 set_percent(&gemodel.h, 0);
 299                                 set_percent(&gemodel.k1, 1.);
 300                                 loss_type = NETEM_LOSS_GE;
 301
 302                                 if (!NEXT_IS_NUMBER())
 303                                         continue;
 304                                 NEXT_ARG();
 305                                 if (get_percent(&gemodel.r, *argv)) {
 306                                         explain1("loss gemodel r");
 307                                         return -1;
 308                                 }
 309
 310                                 if (!NEXT_IS_NUMBER())
 311                                         continue;
 312                                 NEXT_ARG();
 313                                 if (get_percent(&gemodel.h, *argv)) {
 314                                         explain1("loss gemodel h");
 315                                         return -1;
 316                                 }
 317
 318                                 if (!NEXT_IS_NUMBER())
 319                                         continue;
 320                                 NEXT_ARG();
 321                                 if (get_percent(&gemodel.k1, *argv)) {
 322                                         explain1("loss gemodel k");
 323                                         return -1;
 324                                 }
 325                         } else {
 326                                 fprintf(stderr, "Unknown loss parameter: %s\n",
 327                                         *argv);
 328                                 return -1;
 329                         }
 330                 } else if (matches(*argv, "ecn") == 0) {
 331                                 present[TCA_NETEM_ECN] = 1;
 332                 } else if (matches(*argv, "reorder") == 0) {
 333                         NEXT_ARG();
 334                         present[TCA_NETEM_REORDER] = 1;
 335                         if (get_percent(&reorder.probability, *argv)) {
 336                                 explain1("reorder");
 337                                 return -1;
 338                         }
 339                         if (NEXT_IS_NUMBER()) {
 340                                 NEXT_ARG();
 341                                 ++present[TCA_NETEM_CORR];
 342                                 if (get_percent(&reorder.correlation, *argv)) {
 343                                         explain1("reorder");
 344                                         return -1;
 345                                 }
 346                         }
 347                 } else if (matches(*argv, "corrupt") == 0) {
 348                         NEXT_ARG();
 349                         present[TCA_NETEM_CORRUPT] = 1;
 350                         if (get_percent(&corrupt.probability, *argv)) {
 351                                 explain1("corrupt");
 352                                 return -1;
 353                         }
 354                         if (NEXT_IS_NUMBER()) {
 355                                 NEXT_ARG();
 356                                 ++present[TCA_NETEM_CORR];
 357                                 if (get_percent(&corrupt.correlation, *argv)) {
 358                                         explain1("corrupt");
 359                                         return -1;
 360                                 }
 361                         }
 362                 } else if (matches(*argv, "gap") == 0) {
 363                         NEXT_ARG();
 364                         if (get_u32(&opt.gap, *argv, 0)) {
 365                                 explain1("gap");
 366                                 return -1;
 367                         }
 368                 } else if (matches(*argv, "duplicate") == 0) {
 369                         NEXT_ARG();
 370                         if (get_percent(&opt.duplicate, *argv)) {
 371                                 explain1("duplicate");
 372                                 return -1;
 373                         }
 374                         if (NEXT_IS_NUMBER()) {
 375                                 NEXT_ARG();
 376                                 if (get_percent(&cor.dup_corr, *argv)) {
 377                                         explain1("duplicate");
 378                                         return -1;
 379                                 }
 380                         }
 381                 } else if (matches(*argv, "distribution") == 0) {
 382                         NEXT_ARG();
 383                         dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
 384                         dist_size = get_distribution(*argv, dist_data, MAX_DIST);
 385                         if (dist_size <= 0) {
 386                                 free(dist_data);
 387                                 return -1;
 388                         }
 389                 } else if (matches(*argv, "rate") == 0) {
 390                         ++present[TCA_NETEM_RATE];
 391                         NEXT_ARG();
 392                         if (get_rate(&rate.rate, *argv)) {
 393                                 explain1("rate");
 394                                 return -1;
 395                         }
 396                         if (NEXT_IS_NUMBER()) {
 397                                 NEXT_ARG();
 398                                 if (get_s32(&rate.packet_overhead, *argv, 0)) {
 399                                         explain1("rate");
 400                                         return -1;
 401                                 }
 402                         }
 403                         if (NEXT_IS_NUMBER()) {
 404                                 NEXT_ARG();
 405                                 if (get_u32(&rate.cell_size, *argv, 0)) {
 406                                         explain1("rate");
 407                                         return -1;
 408                                 }
 409                         }
 410                         if (NEXT_IS_NUMBER()) {
 411                                 NEXT_ARG();
 412                                 if (get_s32(&rate.cell_overhead, *argv, 0)) {
 413                                         explain1("rate");
 414                                         return -1;
 415                                 }
 416                         }
 417                 } else if (strcmp(*argv, "help") == 0) {
 418                         explain();
 419                         return -1;
 420                 } else {
 421                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 422                         explain();
 423                         return -1;
 424                 }
 425         }
 426
 427         tail = NLMSG_TAIL(n);
 428
 429         if (reorder.probability) {
 430                 if (opt.latency == 0) {
 431                         fprintf(stderr, "reordering not possible without specifying some delay\n");
 432                         explain();
 433                         return -1;
 434                 }
 435                 if (opt.gap == 0)
 436                         opt.gap = 1;
 437         } else if (opt.gap > 0) {
 438                 fprintf(stderr, "gap specified without reorder probability\n");
 439                 explain();
 440                 return -1;
 441         }
 442
 443         if (present[TCA_NETEM_ECN]) {
 444                 if (opt.loss <= 0 && loss_type == NETEM_LOSS_UNSPEC) {
 445                         fprintf(stderr, "ecn requested without loss model\n");
 446                         explain();
 447                         return -1;
 448                 }
 449         }
 450
 451         if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
 452                 fprintf(stderr, "distribution specified but no latency and jitter values\n");
 453                 explain();
 454                 return -1;
 455         }
 456
 457         if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
 458                 return -1;
 459
 460         if (present[TCA_NETEM_CORR] &&
 461             addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
 462                         return -1;
 463
 464         if (present[TCA_NETEM_REORDER] &&
 465             addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
 466                 return -1;
 467
 468         if (present[TCA_NETEM_ECN] &&
 469             addattr_l(n, 1024, TCA_NETEM_ECN, &present[TCA_NETEM_ECN],
 470                       sizeof(present[TCA_NETEM_ECN])) < 0)
 471                         return -1;
 472
 473         if (present[TCA_NETEM_CORRUPT] &&
 474             addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
 475                 return -1;
 476
 477         if (loss_type != NETEM_LOSS_UNSPEC) {
 478                 struct rtattr *start;
 479
 480                 start = addattr_nest(n, 1024, TCA_NETEM_LOSS | NLA_F_NESTED);
 481                 if (loss_type == NETEM_LOSS_GI) {
 482                         if (addattr_l(n, 1024, NETEM_LOSS_GI,
 483                                       &gimodel, sizeof(gimodel)) < 0)
 484                             return -1;
 485                 } else if (loss_type == NETEM_LOSS_GE) {
 486                         if (addattr_l(n, 1024, NETEM_LOSS_GE,
 487                                       &gemodel, sizeof(gemodel)) < 0)
 488                             return -1;
 489                 } else {
 490                         fprintf(stderr, "loss in the weeds!\n");
 491                         return -1;
 492                 }
 493
 494                 addattr_nest_end(n, start);
 495         }
 496
 497         if (present[TCA_NETEM_RATE] &&
 498             addattr_l(n, 1024, TCA_NETEM_RATE, &rate, sizeof(rate)) < 0)
 499                 return -1;
 500
 501         if (dist_data) {
 502                 if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
 503                               TCA_NETEM_DELAY_DIST,
 504                               dist_data, dist_size * sizeof(dist_data[0])) < 0)
 505                         return -1;
 506                 free(dist_data);
 507         }
 508         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 509         return 0;
 510 }
 511
 512 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 513 {
 514         const struct tc_netem_corr *cor = NULL;
 515         const struct tc_netem_reorder *reorder = NULL;
 516         const struct tc_netem_corrupt *corrupt = NULL;
 517         const struct tc_netem_gimodel *gimodel = NULL;
 518         const struct tc_netem_gemodel *gemodel = NULL;
 519         int *ecn = NULL;
 520         struct tc_netem_qopt qopt;
 521         const struct tc_netem_rate *rate = NULL;
 522         int len = RTA_PAYLOAD(opt) - sizeof(qopt);
 523         SPRINT_BUF(b1);
 524
 525         if (opt == NULL)
 526                 return 0;
 527
 528         if (len < 0) {
 529                 fprintf(stderr, "options size error\n");
 530                 return -1;
 531         }
 532         memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
 533
 534         if (len > 0) {
 535                 struct rtattr *tb[TCA_NETEM_MAX+1];
 536                 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
 537                              len);
 538
 539                 if (tb[TCA_NETEM_CORR]) {
 540                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
 541                                 return -1;
 542                         cor = RTA_DATA(tb[TCA_NETEM_CORR]);
 543                 }
 544                 if (tb[TCA_NETEM_REORDER]) {
 545                         if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
 546                                 return -1;
 547                         reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
 548                 }
 549                 if (tb[TCA_NETEM_CORRUPT]) {
 550                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
 551                                 return -1;
 552                         corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
 553                 }
 554                 if (tb[TCA_NETEM_LOSS]) {
 555                         struct rtattr *lb[NETEM_LOSS_MAX + 1];
 556
 557                         parse_rtattr_nested(lb, NETEM_LOSS_MAX, tb[TCA_NETEM_LOSS]);
 558                         if (lb[NETEM_LOSS_GI])
 559                                 gemodel = RTA_DATA(lb[NETEM_LOSS_GI]);
 560                         if (lb[NETEM_LOSS_GE])
 561                                 gemodel = RTA_DATA(lb[NETEM_LOSS_GE]);
 562                 }
 563                 if (tb[TCA_NETEM_RATE]) {
 564                         if (RTA_PAYLOAD(tb[TCA_NETEM_RATE]) < sizeof(*rate))
 565                                 return -1;
 566                         rate = RTA_DATA(tb[TCA_NETEM_RATE]);
 567                 }
 568                 if (tb[TCA_NETEM_ECN]) {
 569                         if (RTA_PAYLOAD(tb[TCA_NETEM_ECN]) < sizeof(*ecn))
 570                                 return -1;
 571                         ecn = RTA_DATA(tb[TCA_NETEM_ECN]);
 572                 }
 573         }
 574
 575         fprintf(f, "limit %d", qopt.limit);
 576
 577         if (qopt.latency) {
 578                 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
 579
 580                 if (qopt.jitter) {
 581                         fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
 582                         if (cor && cor->delay_corr)
 583                                 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
 584                 }
 585         }
 586
 587         if (qopt.loss) {
 588                 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
 589                 if (cor && cor->loss_corr)
 590                         fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
 591         }
 592
 593         if (gimodel) {
 594                 fprintf(f, " loss state p13 %s", sprint_percent(gimodel->p13, b1));
 595                 fprintf(f, " p31 %s", sprint_percent(gimodel->p31, b1));
 596                 fprintf(f, " p32 %s", sprint_percent(gimodel->p32, b1));
 597                 fprintf(f, " p23 %s", sprint_percent(gimodel->p23, b1));
 598                 fprintf(f, " p14 %s", sprint_percent(gimodel->p14, b1));
 599         }
 600
 601         if (gemodel) {
 602                 fprintf(f, "loss gemodel p %s",
 603                         sprint_percent(gemodel->p, b1));
 604                 fprintf(f, " r %s", sprint_percent(gemodel->r, b1));
 605                 fprintf(f, " 1-h %s", sprint_percent(gemodel->h, b1));
 606                 fprintf(f, " 1-k %s", sprint_percent(gemodel->k1, b1));
 607         }
 608
 609         if (qopt.duplicate) {
 610                 fprintf(f, " duplicate %s",
 611                         sprint_percent(qopt.duplicate, b1));
 612                 if (cor && cor->dup_corr)
 613                         fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
 614         }
 615
 616         if (reorder && reorder->probability) {
 617                 fprintf(f, " reorder %s",
 618                         sprint_percent(reorder->probability, b1));
 619                 if (reorder->correlation)
 620                         fprintf(f, " %s",
 621                                 sprint_percent(reorder->correlation, b1));
 622         }
 623
 624         if (corrupt && corrupt->probability) {
 625                 fprintf(f, " corrupt %s",
 626                         sprint_percent(corrupt->probability, b1));
 627                 if (corrupt->correlation)
 628                         fprintf(f, " %s",
 629                                 sprint_percent(corrupt->correlation, b1));
 630         }
 631
 632         if (rate && rate->rate) {
 633                 fprintf(f, " rate %s", sprint_rate(rate->rate, b1));
 634                 if (rate->packet_overhead)
 635                         fprintf(f, " packetoverhead %d", rate->packet_overhead);
 636                 if (rate->cell_size)
 637                         fprintf(f, " cellsize %u", rate->cell_size);
 638                 if (rate->cell_overhead)
 639                         fprintf(f, " celloverhead %d", rate->cell_overhead);
 640         }
 641
 642         if (ecn)
 643                 fprintf(f, " ecn ");
 644
 645         if (qopt.gap)
 646                 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
 647
 648
 649         return 0;
 650 }
 651
 652 struct qdisc_util netem_qdisc_util = {
 653         .id             = "netem",
 654         .parse_qopt     = netem_parse_opt,
 655         .print_qopt     = netem_print_opt,
 656 };
 657