tc/q_gred.c

   1 /*
   2  * q_gred.c             GRED.
   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:    J Hadi Salim(hadi@nortelnetworks.com)
  10  *             code ruthlessly ripped from
  11  *             Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  12  *
  13  */
  14
  15 #include <stdio.h>
  16 #include <stdlib.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 <math.h>
  25
  26 #include "utils.h"
  27 #include "tc_util.h"
  28
  29 #include "tc_red.h"
  30
  31
  32 #if 0
  33 #define DPRINTF(format,args...) fprintf(stderr,format,##args)
  34 #else
  35 #define DPRINTF(format,args...)
  36 #endif
  37
  38 static void explain(void)
  39 {
  40         fprintf(stderr, "Usage: tc qdisc { add | replace | change } ... gred setup vqs NUMBER\n");
  41         fprintf(stderr, "           default DEFAULT_VQ [ grio ] [ limit BYTES ]\n");
  42         fprintf(stderr, "       tc qdisc change ... gred vq VQ [ prio VALUE ] limit BYTES\n");
  43         fprintf(stderr, "           min BYTES max BYTES avpkt BYTES [ burst PACKETS ]\n");
  44         fprintf(stderr, "           [ probability PROBABILITY ] [ bandwidth KBPS ]\n");
  45 }
  46
  47 static int init_gred(struct qdisc_util *qu, int argc, char **argv,
  48                      struct nlmsghdr *n)
  49 {
  50
  51         struct rtattr *tail;
  52         struct tc_gred_sopt opt = { 0 };
  53         __u32 limit = 0;
  54
  55         opt.def_DP = MAX_DPs;
  56
  57         while (argc > 0) {
  58                 DPRINTF(stderr,"init_gred: invoked with %s\n",*argv);
  59                 if (strcmp(*argv, "vqs") == 0 ||
  60                     strcmp(*argv, "DPs") == 0) {
  61                         NEXT_ARG();
  62                         if (get_unsigned(&opt.DPs, *argv, 10)) {
  63                                 fprintf(stderr, "Illegal \"vqs\"\n");
  64                                 return -1;
  65                         } else if (opt.DPs > MAX_DPs) {
  66                                 fprintf(stderr, "GRED: only %u VQs are "
  67                                         "currently supported\n", MAX_DPs);
  68                                 return -1;
  69                         }
  70                 } else if (strcmp(*argv, "default") == 0) {
  71                         if (opt.DPs == 0) {
  72                                 fprintf(stderr, "\"default\" must be defined "
  73                                         "after \"vqs\"\n");
  74                                 return -1;
  75                         }
  76                         NEXT_ARG();
  77                         if (get_unsigned(&opt.def_DP, *argv, 10)) {
  78                                 fprintf(stderr, "Illegal \"default\"\n");
  79                                 return -1;
  80                         } else if (opt.def_DP >= opt.DPs) {
  81                                 fprintf(stderr, "\"default\" must be less than "
  82                                         "\"vqs\"\n");
  83                                 return -1;
  84                         }
  85                 } else if (strcmp(*argv, "grio") == 0) {
  86                         opt.grio = 1;
  87                 } else if (strcmp(*argv, "limit") == 0) {
  88                         NEXT_ARG();
  89                         if (get_size(&limit, *argv)) {
  90                                 fprintf(stderr, "Illegal \"limit\"\n");
  91                                 return -1;
  92                         }
  93                 } else if (strcmp(*argv, "help") == 0) {
  94                         explain();
  95                         return -1;
  96                 } else {
  97                         fprintf(stderr, "What is \"%s\"?\n", *argv);
  98                         explain();
  99                         return -1;
 100                 }
 101                 argc--; argv++;
 102         }
 103
 104         if (!opt.DPs || opt.def_DP == MAX_DPs) {
 105                 fprintf(stderr, "Illegal gred setup parameters \n");
 106                 return -1;
 107         }
 108
 109         DPRINTF("TC_GRED: sending DPs=%u def_DP=%u\n",opt.DPs,opt.def_DP);
 110         n->nlmsg_flags|=NLM_F_CREATE;
 111         tail = NLMSG_TAIL(n);
 112         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 113         addattr_l(n, 1024, TCA_GRED_DPS, &opt, sizeof(struct tc_gred_sopt));
 114         if (limit)
 115                 addattr32(n, 1024, TCA_GRED_LIMIT, limit);
 116         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 117         return 0;
 118 }
 119 /*
 120 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 121 */
 122 static int gred_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
 123 {
 124         int ok=0;
 125         struct tc_gred_qopt opt = { 0 };
 126         unsigned burst = 0;
 127         unsigned avpkt = 0;
 128         double probability = 0.02;
 129         unsigned rate = 0;
 130         int parm;
 131         __u8 sbuf[256];
 132         struct rtattr *tail;
 133         __u32 max_P;
 134
 135         opt.DP = MAX_DPs;
 136
 137         while (argc > 0) {
 138                 if (strcmp(*argv, "limit") == 0) {
 139                         NEXT_ARG();
 140                         if (get_size(&opt.limit, *argv)) {
 141                                 fprintf(stderr, "Illegal \"limit\"\n");
 142                                 return -1;
 143                         }
 144                         ok++;
 145                 } else if (strcmp(*argv, "setup") == 0) {
 146                         if (ok) {
 147                                 fprintf(stderr, "Illegal \"setup\"\n");
 148                                 return -1;
 149                         }
 150                         return init_gred(qu, argc-1, argv+1, n);
 151                 } else if (strcmp(*argv, "min") == 0) {
 152                         NEXT_ARG();
 153                         if (get_size(&opt.qth_min, *argv)) {
 154                                 fprintf(stderr, "Illegal \"min\"\n");
 155                                 return -1;
 156                         }
 157                         ok++;
 158                 } else if (strcmp(*argv, "max") == 0) {
 159                         NEXT_ARG();
 160                         if (get_size(&opt.qth_max, *argv)) {
 161                                 fprintf(stderr, "Illegal \"max\"\n");
 162                                 return -1;
 163                         }
 164                         ok++;
 165                 } else if (strcmp(*argv, "vq") == 0 ||
 166                            strcmp(*argv, "DP") == 0) {
 167                         NEXT_ARG();
 168                         if (get_unsigned(&opt.DP, *argv, 10)) {
 169                                 fprintf(stderr, "Illegal \"vq\"\n");
 170                                 return -1;
 171                         } else if (opt.DP >= MAX_DPs) {
 172                                 fprintf(stderr, "GRED: only %u VQs are "
 173                                         "currently supported\n", MAX_DPs);
 174                                 return -1;
 175                         } /* need a better error check */
 176                         ok++;
 177                 } else if (strcmp(*argv, "burst") == 0) {
 178                         NEXT_ARG();
 179                         if (get_unsigned(&burst, *argv, 0)) {
 180                                 fprintf(stderr, "Illegal \"burst\"\n");
 181                                 return -1;
 182                         }
 183                         ok++;
 184                 } else if (strcmp(*argv, "avpkt") == 0) {
 185                         NEXT_ARG();
 186                         if (get_size(&avpkt, *argv)) {
 187                                 fprintf(stderr, "Illegal \"avpkt\"\n");
 188                                 return -1;
 189                         }
 190                         ok++;
 191                 } else if (strcmp(*argv, "probability") == 0) {
 192                         NEXT_ARG();
 193                         if (sscanf(*argv, "%lg", &probability) != 1) {
 194                                 fprintf(stderr, "Illegal \"probability\"\n");
 195                                 return -1;
 196                         }
 197                         ok++;
 198                 } else if (strcmp(*argv, "prio") == 0) {
 199                         NEXT_ARG();
 200                         opt.prio=strtol(*argv, (char **)NULL, 10);
 201                         /* some error check here */
 202                         ok++;
 203                 } else if (strcmp(*argv, "bandwidth") == 0) {
 204                         NEXT_ARG();
 205                         if (get_rate(&rate, *argv)) {
 206                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
 207                                 return -1;
 208                         }
 209                         ok++;
 210                 } else if (strcmp(*argv, "help") == 0) {
 211                         explain();
 212                         return -1;
 213                 } else {
 214                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 215                         explain();
 216                         return -1;
 217                 }
 218                 argc--; argv++;
 219         }
 220
 221         if (!ok) {
 222                 explain();
 223                 return -1;
 224         }
 225         if (opt.DP == MAX_DPs || !opt.limit || !opt.qth_min || !opt.qth_max ||
 226             !avpkt) {
 227                 fprintf(stderr, "Required parameter (vq, limit, min, max, "
 228                         "avpkt) is missing\n");
 229                 return -1;
 230         }
 231         if (!burst) {
 232                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 233                 fprintf(stderr, "GRED: set burst to %u\n", burst);
 234         }
 235         if (!rate) {
 236                 get_rate(&rate, "10Mbit");
 237                 fprintf(stderr, "GRED: set bandwidth to 10Mbit\n");
 238         }
 239         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 240                 fprintf(stderr, "GRED: failed to calculate EWMA constant.\n");
 241                 return -1;
 242         }
 243         if (parm >= 10)
 244                 fprintf(stderr, "GRED: WARNING. Burst %u seems to be too "
 245                     "large.\n", burst);
 246         opt.Wlog = parm;
 247         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 248                 fprintf(stderr, "GRED: failed to calculate probability.\n");
 249                 return -1;
 250         }
 251         opt.Plog = parm;
 252         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0)
 253             {
 254                 fprintf(stderr, "GRED: failed to calculate idle damping "
 255                     "table.\n");
 256                 return -1;
 257         }
 258         opt.Scell_log = parm;
 259
 260         tail = NLMSG_TAIL(n);
 261         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 262         addattr_l(n, 1024, TCA_GRED_PARMS, &opt, sizeof(opt));
 263         addattr_l(n, 1024, TCA_GRED_STAB, sbuf, 256);
 264         max_P = probability * pow(2, 32);
 265         addattr32(n, 1024, TCA_GRED_MAX_P, max_P);
 266         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 267         return 0;
 268 }
 269
 270 static int gred_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 271 {
 272         struct rtattr *tb[TCA_GRED_MAX + 1];
 273         struct tc_gred_sopt *sopt;
 274         struct tc_gred_qopt *qopt;
 275         __u32 *max_p = NULL;
 276         __u32 *limit = NULL;
 277         unsigned i;
 278         SPRINT_BUF(b1);
 279         SPRINT_BUF(b2);
 280         SPRINT_BUF(b3);
 281
 282         if (opt == NULL)
 283                 return 0;
 284
 285         parse_rtattr_nested(tb, TCA_GRED_MAX, opt);
 286
 287         if (tb[TCA_GRED_PARMS] == NULL)
 288                 return -1;
 289
 290         if (tb[TCA_GRED_MAX_P] &&
 291             RTA_PAYLOAD(tb[TCA_GRED_MAX_P]) >= sizeof(__u32) * MAX_DPs)
 292                 max_p = RTA_DATA(tb[TCA_GRED_MAX_P]);
 293
 294         if (tb[TCA_GRED_LIMIT] &&
 295             RTA_PAYLOAD(tb[TCA_GRED_LIMIT]) == sizeof(__u32))
 296                 limit = RTA_DATA(tb[TCA_GRED_LIMIT]);
 297
 298         sopt = RTA_DATA(tb[TCA_GRED_DPS]);
 299         qopt = RTA_DATA(tb[TCA_GRED_PARMS]);
 300         if (RTA_PAYLOAD(tb[TCA_GRED_DPS]) < sizeof(*sopt) ||
 301             RTA_PAYLOAD(tb[TCA_GRED_PARMS]) < sizeof(*qopt)*MAX_DPs) {
 302                 fprintf(f,"\n GRED received message smaller than expected\n");
 303                 return -1;
 304         }
 305
 306 /* Bad hack! should really return a proper message as shown above*/
 307
 308         fprintf(f, "vqs %u default %u %s",
 309                 sopt->DPs,
 310                 sopt->def_DP,
 311                 sopt->grio ? "grio " : "");
 312
 313         if (limit)
 314                 fprintf(f, "limit %s ",
 315                         sprint_size(*limit, b1));
 316
 317         for (i=0;i<MAX_DPs;i++, qopt++) {
 318                 if (qopt->DP >= MAX_DPs) continue;
 319                 fprintf(f, "\n vq %u prio %hhu limit %s min %s max %s ",
 320                         qopt->DP,
 321                         qopt->prio,
 322                         sprint_size(qopt->limit, b1),
 323                         sprint_size(qopt->qth_min, b2),
 324                         sprint_size(qopt->qth_max, b3));
 325                 if (show_details) {
 326                         fprintf(f, "ewma %u ", qopt->Wlog);
 327                         if (max_p)
 328                                 fprintf(f, "probability %lg ", max_p[i] / pow(2, 32));
 329                         else
 330                                 fprintf(f, "Plog %u ", qopt->Plog);
 331                         fprintf(f, "Scell_log %u ", qopt->Scell_log);
 332                 }
 333                 if (show_stats) {
 334                         fprintf(f, "\n  Queue size: average %s current %s ",
 335                                 sprint_size(qopt->qave, b1),
 336                                 sprint_size(qopt->backlog, b2));
 337                         fprintf(f, "\n  Dropped packets: forced %u early %u pdrop %u other %u ",
 338                                 qopt->forced,
 339                                 qopt->early,
 340                                 qopt->pdrop,
 341                                 qopt->other);
 342                         fprintf(f, "\n  Total packets: %u (%s) ",
 343                                 qopt->packets,
 344                                 sprint_size(qopt->bytesin, b1));
 345                 }
 346         }
 347         return 0;
 348 }
 349
 350 struct qdisc_util gred_qdisc_util = {
 351         .id             = "gred",
 352         .parse_qopt     = gred_parse_opt,
 353         .print_qopt     = gred_print_opt,
 354 };