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 /*
  48  * Simplistic file parser for distrbution data.
  49  * Format is:
  50  *      # comment line(s)
  51  *      data0 data1
  52  */
  53 #define MAXDIST 65536
  54 static int get_distribution(const char *type, __s16 *data)
  55 {
  56         FILE *f;
  57         int n;
  58         long x;
  59         size_t len;
  60         char *line = NULL;
  61         char name[128];
  62
  63         snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
  64         if ((f = fopen(name, "r")) == NULL) {
  65                 fprintf(stderr, "No distribution data for %s (%s: %s)\n",
  66                         type, name, strerror(errno));
  67                 return -1;
  68         }
  69
  70         n = 0;
  71         while (getline(&line, &len, f) != -1) {
  72                 char *p, *endp;
  73                 if (*line == '\n' || *line == '#')
  74                         continue;
  75
  76                 for (p = line; ; p = endp) {
  77                         x = strtol(p, &endp, 0);
  78                         if (endp == p)
  79                                 break;
  80
  81                         if (n >= MAXDIST) {
  82                                 fprintf(stderr, "%s: too much data\n",
  83                                         name);
  84                                 n = -1;
  85                                 goto error;
  86                         }
  87                         data[n++] = x;
  88                 }
  89         }
  90  error:
  91         free(line);
  92         fclose(f);
  93         return n;
  94 }
  95
  96 static int isnumber(const char *arg)
  97 {
  98         char *p;
  99         (void) strtod(arg, &p);
 100         return (p != arg);
 101 }
 102
 103 #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1]))
 104
 105 /* Adjust for the fact that psched_ticks aren't always usecs
 106    (based on kernel PSCHED_CLOCK configuration */
 107 static int get_ticks(__u32 *ticks, const char *str)
 108 {
 109         unsigned t;
 110
 111         if(get_time(&t, str))
 112                 return -1;
 113
 114         if (tc_core_time2big(t)) {
 115                 fprintf(stderr, "Illegal %u time (too large)\n", t);
 116                 return -1;
 117         }
 118
 119         *ticks = tc_core_time2tick(t);
 120         return 0;
 121 }
 122
 123 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 124                            struct nlmsghdr *n)
 125 {
 126         size_t dist_size = 0;
 127         struct rtattr *tail;
 128         struct tc_netem_qopt opt;
 129         struct tc_netem_corr cor;
 130         struct tc_netem_reorder reorder;
 131         struct tc_netem_corrupt corrupt;
 132         __s16 *dist_data = NULL;
 133         int present[__TCA_NETEM_MAX];
 134
 135         memset(&opt, 0, sizeof(opt));
 136         opt.limit = 1000;
 137         memset(&cor, 0, sizeof(cor));
 138         memset(&reorder, 0, sizeof(reorder));
 139         memset(&corrupt, 0, sizeof(corrupt));
 140         memset(present, 0, sizeof(present));
 141
 142         while (argc > 0) {
 143                 if (matches(*argv, "limit") == 0) {
 144                         NEXT_ARG();
 145                         if (get_size(&opt.limit, *argv)) {
 146                                 explain1("limit");
 147                                 return -1;
 148                         }
 149                 } else if (matches(*argv, "latency") == 0 ||
 150                            matches(*argv, "delay") == 0) {
 151                         NEXT_ARG();
 152                         if (get_ticks(&opt.latency, *argv)) {
 153                                 explain1("latency");
 154                                 return -1;
 155                         }
 156
 157                         if (NEXT_IS_NUMBER()) {
 158                                 NEXT_ARG();
 159                                 if (get_ticks(&opt.jitter, *argv)) {
 160                                         explain1("latency");
 161                                         return -1;
 162                                 }
 163
 164                                 if (NEXT_IS_NUMBER()) {
 165                                         NEXT_ARG();
 166                                         ++present[TCA_NETEM_CORR];
 167                                         if (get_percent(&cor.delay_corr,                                                        *argv)) {
 168                                                 explain1("latency");
 169                                                 return -1;
 170                                         }
 171                                 }
 172                         }
 173                 } else if (matches(*argv, "loss") == 0 ||
 174                            matches(*argv, "drop") == 0) {
 175                         NEXT_ARG();
 176                         if (get_percent(&opt.loss, *argv)) {
 177                                 explain1("loss");
 178                                 return -1;
 179                         }
 180                         if (NEXT_IS_NUMBER()) {
 181                                 NEXT_ARG();
 182                                 ++present[TCA_NETEM_CORR];
 183                                 if (get_percent(&cor.loss_corr, *argv)) {
 184                                         explain1("loss");
 185                                         return -1;
 186                                 }
 187                         }
 188                 } else if (matches(*argv, "reorder") == 0) {
 189                         NEXT_ARG();
 190                         present[TCA_NETEM_REORDER] = 1;
 191                         if (get_percent(&reorder.probability, *argv)) {
 192                                 explain1("reorder");
 193                                 return -1;
 194                         }
 195                         if (NEXT_IS_NUMBER()) {
 196                                 NEXT_ARG();
 197                                 ++present[TCA_NETEM_CORR];
 198                                 if (get_percent(&reorder.correlation, *argv)) {
 199                                         explain1("reorder");
 200                                         return -1;
 201                                 }
 202                         }
 203                 } else if (matches(*argv, "corrupt") == 0) {
 204                         NEXT_ARG();
 205                         present[TCA_NETEM_CORRUPT] = 1;
 206                         if (get_percent(&corrupt.probability, *argv)) {
 207                                 explain1("corrupt");
 208                                 return -1;
 209                         }
 210                         if (NEXT_IS_NUMBER()) {
 211                                 NEXT_ARG();
 212                                 ++present[TCA_NETEM_CORR];
 213                                 if (get_percent(&corrupt.correlation, *argv)) {
 214                                         explain1("corrupt");
 215                                         return -1;
 216                                 }
 217                         }
 218                 } else if (matches(*argv, "gap") == 0) {
 219                         NEXT_ARG();
 220                         if (get_u32(&opt.gap, *argv, 0)) {
 221                                 explain1("gap");
 222                                 return -1;
 223                         }
 224                 } else if (matches(*argv, "duplicate") == 0) {
 225                         NEXT_ARG();
 226                         if (get_percent(&opt.duplicate, *argv)) {
 227                                 explain1("duplicate");
 228                                 return -1;
 229                         }
 230                         if (NEXT_IS_NUMBER()) {
 231                                 NEXT_ARG();
 232                                 if (get_percent(&cor.dup_corr, *argv)) {
 233                                         explain1("duplicate");
 234                                         return -1;
 235                                 }
 236                         }
 237                 } else if (matches(*argv, "distribution") == 0) {
 238                         NEXT_ARG();
 239                         dist_data = alloca(MAXDIST);
 240                         dist_size = get_distribution(*argv, dist_data);
 241                         if (dist_size < 0)
 242                                 return -1;
 243                 } else if (strcmp(*argv, "help") == 0) {
 244                         explain();
 245                         return -1;
 246                 } else {
 247                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 248                         explain();
 249                         return -1;
 250                 }
 251                 argc--; argv++;
 252         }
 253
 254         tail = NLMSG_TAIL(n);
 255
 256         if (reorder.probability) {
 257                 if (opt.latency == 0) {
 258                         fprintf(stderr, "reordering not possible without specifying some delay\n");
 259                 }
 260                 if (opt.gap == 0)
 261                         opt.gap = 1;
 262         } else if (opt.gap > 0) {
 263                 fprintf(stderr, "gap specified without reorder probability\n");
 264                 explain();
 265                 return -1;
 266         }
 267
 268         if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
 269                 fprintf(stderr, "distribution specified but no latency and jitter values\n");
 270                 explain();
 271                 return -1;
 272         }
 273
 274         if (addattr_l(n, TCA_BUF_MAX, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
 275                 return -1;
 276
 277         if (present[TCA_NETEM_CORR] &&
 278             addattr_l(n, TCA_BUF_MAX, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
 279                         return -1;
 280
 281         if (present[TCA_NETEM_REORDER] &&
 282             addattr_l(n, TCA_BUF_MAX, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
 283                 return -1;
 284
 285         if (present[TCA_NETEM_CORRUPT] &&
 286             addattr_l(n, TCA_BUF_MAX, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
 287                 return -1;
 288
 289         if (dist_data) {
 290                 if (addattr_l(n, 32768, TCA_NETEM_DELAY_DIST,
 291                               dist_data, dist_size*sizeof(dist_data[0])) < 0)
 292                         return -1;
 293         }
 294         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 295         return 0;
 296 }
 297
 298 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 299 {
 300         const struct tc_netem_corr *cor = NULL;
 301         const struct tc_netem_reorder *reorder = NULL;
 302         const struct tc_netem_corrupt *corrupt = NULL;
 303         struct tc_netem_qopt qopt;
 304         int len = RTA_PAYLOAD(opt) - sizeof(qopt);
 305         SPRINT_BUF(b1);
 306
 307         if (opt == NULL)
 308                 return 0;
 309
 310         if (len < 0) {
 311                 fprintf(stderr, "options size error\n");
 312                 return -1;
 313         }
 314         memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
 315
 316         if (len > 0) {
 317                 struct rtattr *tb[TCA_NETEM_MAX+1];
 318                 parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
 319                              len);
 320
 321                 if (tb[TCA_NETEM_CORR]) {
 322                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
 323                                 return -1;
 324                         cor = RTA_DATA(tb[TCA_NETEM_CORR]);
 325                 }
 326                 if (tb[TCA_NETEM_REORDER]) {
 327                         if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
 328                                 return -1;
 329                         reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
 330                 }
 331                 if (tb[TCA_NETEM_CORRUPT]) {
 332                         if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
 333                                 return -1;
 334                         corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
 335                 }
 336         }
 337
 338         fprintf(f, "limit %d", qopt.limit);
 339
 340         if (qopt.latency) {
 341                 fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
 342
 343                 if (qopt.jitter) {
 344                         fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
 345                         if (cor && cor->delay_corr)
 346                                 fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
 347                 }
 348         }
 349
 350         if (qopt.loss) {
 351                 fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
 352                 if (cor && cor->loss_corr)
 353                         fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
 354         }
 355
 356         if (qopt.duplicate) {
 357                 fprintf(f, " duplicate %s",
 358                         sprint_percent(qopt.duplicate, b1));
 359                 if (cor && cor->dup_corr)
 360                         fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
 361         }
 362
 363         if (reorder && reorder->probability) {
 364                 fprintf(f, " reorder %s",
 365                         sprint_percent(reorder->probability, b1));
 366                 if (reorder->correlation)
 367                         fprintf(f, " %s",
 368                                 sprint_percent(reorder->correlation, b1));
 369         }
 370
 371         if (corrupt && corrupt->probability) {
 372                 fprintf(f, " corrupt %s",
 373                         sprint_percent(corrupt->probability, b1));
 374                 if (corrupt->correlation)
 375                         fprintf(f, " %s",
 376                                 sprint_percent(corrupt->correlation, b1));
 377         }
 378
 379         if (qopt.gap)
 380                 fprintf(f, " gap %lu", (unsigned long)qopt.gap);
 381
 382         return 0;
 383 }
 384
 385 struct qdisc_util netem_qdisc_util = {
 386         .id             = "netem",
 387         .parse_qopt     = netem_parse_opt,
 388         .print_qopt     = netem_print_opt,
 389 };
 390