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