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 #define usage() return(-1)
  46
  47 /* Upper bound on size of distribution
  48  *  really (TCA_BUF_MAX - other headers) / sizeof (__s16)
  49  */
  50 #define MAX_DIST        (16*1024)
  51
  52 /*
  53  * Simplistic file parser for distrbution data.
  54  * Format is:
  55  *      # comment line(s)
  56  *      data0 data1 ...
  57  */
  58 static int get_distribution(const char *type, __s16 *data, int maxdata)
  59 {
  60         FILE *f;
  61         int n;
  62         long x;
  63         size_t len;
  64         char *line = NULL;
  65         char name[128];
  66
  67         snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
  68         if ((f = fopen(name, "r")) == NULL) {
  69                 fprintf(stderr, "No distribution data for %s (%s: %s)\n",
  70                         type, name, strerror(errno));
  71                 return -1;
  72         }
  73
  74         n = 0;
  75         while (getline(&line, &len, f) != -1) {
  76                 char *p, *endp;
  77                 if (*line == '\n' || *line == '#')
  78                         continue;
  79
  80                 for (p = line; ; p = endp) {
  81                         x = strtol(p, &endp, 0);
  82                         if (endp == p)
  83                                 break;
  84
  85                         if (n >= maxdata) {
  86                                 fprintf(stderr, "%s: too much data\n",
  87                                         name);
  88                                 n = -1;
  89                                 goto error;
  90                         }
  91                         data[n++] = x;
  92                 }
  93         }
  94  error:
  95         free(line);
  96         fclose(f);
  97         return n;
  98 }
  99
 100 static int isnumber(const char *arg)
 101 {
 102         char *p;
 103         (void) strtod(arg, &p);
 104         return (p != arg);
 105 }
 106
 107 #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1]))
 108
 109 /* Adjust for the fact that psched_ticks aren't always usecs
 110    (based on kernel PSCHED_CLOCK configuration */
 111 static int get_ticks(__u32 *ticks, const char *str)
 112 {
 113         unsigned t;
 114
 115         if(get_time(&t, str))
 116                 return -1;
 117
 118         if (tc_core_time2big(t)) {
 119                 fprintf(stderr, "Illegal %u time (too large)\n", t);
 120                 return -1;
 121         }
 122
 123         *ticks = tc_core_time2tick(t);
 124         return 0;
 125 }
 126
 127 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 128                            struct nlmsghdr *n)
 129 {
 130         size_t dist_size = 0;
 131         struct rtattr *tail;
 132         struct tc_netem_qopt opt;
 133         struct tc_netem_corr cor;
 134         struct tc_netem_reorder reorder;
 135         struct tc_netem_corrupt corrupt;
 136         __s16 *dist_data = NULL;
 137         int present[__TCA_NETEM_MAX];
 138
 139         memset(&opt, 0, sizeof(opt));
 140         opt.limit = 1000;
 141         memset(&cor, 0, sizeof(cor));
 142         memset(&reorder, 0, sizeof(reorder));
 143         memset(&corrupt, 0, sizeof(corrupt));
 144         memset(present, 0, sizeof(present));
 145
 146         while (argc > 0) {
 147                 if (matches(*argv, "limit") == 0) {
 148                         NEXT_ARG();
 149                         if (get_size(&opt.limit, *argv)) {
 150                                 explain1("limit");
 151                                 return -1;
 152                         }
 153                 } else if (matches(*argv, "latency") == 0 ||
 154                            matches(*argv, "delay") == 0) {
 155                         NEXT_ARG();
 156                         if (get_ticks(&opt.latency, *argv)) {
 157                                 explain1("latency");
 158                                 return -1;
 159                         }
 160
 161                         if (NEXT_IS_NUMBER()) {
 162                                 NEXT_ARG();
 163                                 if (get_ticks(&opt.jitter, *argv)) {
 164                                         explain1("latency");
 165                                         return -1;
 166                                 }
 167
 168                                 if (NEXT_IS_NUMBER()) {
 169                                         NEXT_ARG();
 170                                         ++present[TCA_NETEM_CORR];
 171                                         if (get_percent(&cor.delay_corr,                                                        *argv)) {
 172                                                 explain1("latency");
 173                                                 return -1;
 174                                         }
 175                                 }
 176                         }
 177                 } else if (matches(*argv, "loss") == 0 ||
 178                            matches(*argv, "drop") == 0) {
 179                         NEXT_ARG();
 180                         if (get_percent(&opt.loss, *argv)) {
 181                                 explain1("loss");
 182                                 return -1;
 183                         }
 184                         if (NEXT_IS_NUMBER()) {
 185                                 NEXT_ARG();
 186                                 ++present[TCA_NETEM_CORR];
 187                                 if (get_percent(&cor.loss_corr, *argv)) {
 188                                         explain1("loss");
 189                                         return -1;
 190                                 }
 191                         }
 192                 } else if (matches(*argv, "reorder") == 0) {
 193                         NEXT_ARG();
 194                         present[TCA_NETEM_REORDER] = 1;
 195                         if (get_percent(&reorder.probability, *argv)) {
 196                                 explain1("reorder");
 197                                 return -1;
 198                         }
 199                         if (NEXT_IS_NUMBER()) {
 200                                 NEXT_ARG();
 201                                 ++present[TCA_NETEM_CORR];
 202                                 if (get_percent(&reorder.correlation, *argv)) {
 203                                         explain1("reorder");
 204                                         return -1;
 205                                 }
 206                         }
 207                 } else if (matches(*argv, "corrupt") == 0) {
 208                         NEXT_ARG();
 209                         present[TCA_NETEM_CORRUPT] = 1;
 210                         if (get_percent(&corrupt.probability, *argv)) {
 211                                 explain1("corrupt");
 212                                 return -1;
 213                         }
 214                         if (NEXT_IS_NUMBER()) {
 215                                 NEXT_ARG();
 216                                 ++present[TCA_NETEM_CORR];
 217                                 if (get_percent(&corrupt.correlation, *argv)) {
 218                                         explain1("corrupt");
 219                                         return -1;
 220                                 }
 221                         }
 222                 } else if (matches(*argv, "gap") == 0) {
 223                         NEXT_ARG();
 224                         if (get_u32(&opt.gap, *argv, 0)) {
 225                                 explain1("gap");
 226                                 return -1;
 227                         }
 228                 } else if (matches(*argv, "duplicate") == 0) {
 229                         NEXT_ARG();
 230                         if (get_percent(&opt.duplicate, *argv)) {
 231                                 explain1("duplicate");
 232                                 return -1;
 233                         }
 234                         if (NEXT_IS_NUMBER()) {
 235                                 NEXT_ARG();
 236                                 if (get_percent(&cor.dup_corr, *argv)) {
 237                                         explain1("duplicate");
 238                                         return -1;
 239                                 }
 240                         }
 241                 } else if (matches(*argv, "distribution") == 0) {
 242                         NEXT_ARG();
 243                         dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
 244                         dist_size = get_distribution(*argv, dist_data, MAX_DIST);
 245                         if (dist_size <= 0) {
 246                                 free(dist_data);
 247                                 return -1;
 248                         }
 249                 } else if (strcmp(*argv, "help") == 0) {
 250                         explain();
 251                         return -1;
 252                 } else {
 253                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 254                         explain();
 255                         return -1;
 256                 }
 257                 argc--; argv++;
 258         }
 259
 260         tail = NLMSG_TAIL(n);
 261
 262         if (reorder.probability) {
 263                 if (opt.latency == 0) {
 264                         fprintf(stderr, "reordering not possible without specifying some delay\n");
 265                 }
 266                 if (opt.gap == 0)
 267                         opt.gap = 1;
 268         } else if (opt.gap > 0) {
 269                 fprintf(stderr, "gap specified without reorder probability\n");
 270                 explain();
 271                 return -1;
 272         }
 273
 274         if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
 275                 fprintf(stderr, "distribution specified but no latency and jitter values\n");
 276                 explain();
 277                 return -1;
 278         }
 279
 280         if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
 281                 return -1;
 282
 283         if (present[TCA_NETEM_CORR] &&
 284             addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
 285                         return -1;
 286
 287         if (present[TCA_NETEM_REORDER] &&
 288             addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
 289                 return -1;
 290
 291         if (present[TCA_NETEM_CORRUPT] &&
 292             addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
 293                 return -1;
 294
 295         if (dist_data) {
 296                 if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
 297                               TCA_NETEM_DELAY_DIST,
 298                               dist_data, dist_size * sizeof(dist_data[0])) < 0)
 299                         return -1;
 300                 free(dist_data);
 301         }
 302         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 303         return 0;
 304 }
 305
 306 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 307 {
 308         const struct tc_netem_corr *cor = NULL;
 309         const struct tc_netem_reorder *reorder = NULL;
 310         const struct tc_netem_corrupt *corrupt = NULL;
 311         struct tc_netem_qopt qopt;
 312         int len = RTA_PAYLOAD(opt) - sizeof(qopt);
 313         SPRINT_BUF(b1);
 314
 315         if (opt == NULL)
 316                 return 0;
 317
 318         if (len < 0) {
 319                 fprintf(stderr, "options size error\n");
 320                 return -1;
 321         }
 322         memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
 323
 324         if (len > 0) {
 325                 struct rtattr *tb[TCA_NETEM_MAX+1];
 326                 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
 327                              len);
 328
 329                 if (tb[TCA_NETEM_CORR]) {
 330                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
 331                                 return -1;
 332                         cor = RTA_DATA(tb[TCA_NETEM_CORR]);
 333                 }
 334                 if (tb[TCA_NETEM_REORDER]) {
 335                         if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
 336                                 return -1;
 337                         reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
 338                 }
 339                 if (tb[TCA_NETEM_CORRUPT]) {
 340                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
 341                                 return -1;
 342                         corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
 343                 }
 344         }
 345
 346         fprintf(f, "limit %d", qopt.limit);
 347
 348         if (qopt.latency) {
 349                 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
 350
 351                 if (qopt.jitter) {
 352                         fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
 353                         if (cor && cor->delay_corr)
 354                                 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
 355                 }
 356         }
 357
 358         if (qopt.loss) {
 359                 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
 360                 if (cor && cor->loss_corr)
 361                         fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
 362         }
 363
 364         if (qopt.duplicate) {
 365                 fprintf(f, " duplicate %s",
 366                         sprint_percent(qopt.duplicate, b1));
 367                 if (cor && cor->dup_corr)
 368                         fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
 369         }
 370
 371         if (reorder && reorder->probability) {
 372                 fprintf(f, " reorder %s",
 373                         sprint_percent(reorder->probability, b1));
 374                 if (reorder->correlation)
 375                         fprintf(f, " %s",
 376                                 sprint_percent(reorder->correlation, b1));
 377         }
 378
 379         if (corrupt && corrupt->probability) {
 380                 fprintf(f, " corrupt %s",
 381                         sprint_percent(corrupt->probability, b1));
 382                 if (corrupt->correlation)
 383                         fprintf(f, " %s",
 384                                 sprint_percent(corrupt->correlation, b1));
 385         }
 386
 387         if (qopt.gap)
 388                 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
 389
 390         return 0;
 391 }
 392
 393 struct qdisc_util netem_qdisc_util = {
 394         .id             = "netem",
 395         .parse_qopt     = netem_parse_opt,
 396         .print_qopt     = netem_print_opt,
 397 };
 398