tc/q_red.c

   1 /*
   2  * q_red.c              RED.
   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:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  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
  23 #include "utils.h"
  24 #include "tc_util.h"
  25
  26 #include "tc_red.h"
  27
  28 static void explain(void)
  29 {
  30         fprintf(stderr, "Usage: ... red limit BYTES min BYTES max BYTES avpkt BYTES burst PACKETS\n");
  31         fprintf(stderr, "               probability PROBABILITY bandwidth KBPS [ ecn ]\n");
  32 }
  33
  34 #define usage() return(-1)
  35
  36 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
  37 {
  38         struct tc_red_qopt opt;
  39         unsigned burst = 0;
  40         unsigned avpkt = 0;
  41         double probability = 0.02;
  42         unsigned rate = 0;
  43         int ecn_ok = 0;
  44         int wlog;
  45         __u8 sbuf[256];
  46         struct rtattr *tail;
  47
  48         memset(&opt, 0, sizeof(opt));
  49
  50         while (argc > 0) {
  51                 if (strcmp(*argv, "limit") == 0) {
  52                         NEXT_ARG();
  53                         if (get_size(&opt.limit, *argv)) {
  54                                 fprintf(stderr, "Illegal \"limit\"\n");
  55                                 return -1;
  56                         }
  57                 } else if (strcmp(*argv, "min") == 0) {
  58                         NEXT_ARG();
  59                         if (get_size(&opt.qth_min, *argv)) {
  60                                 fprintf(stderr, "Illegal \"min\"\n");
  61                                 return -1;
  62                         }
  63                 } else if (strcmp(*argv, "max") == 0) {
  64                         NEXT_ARG();
  65                         if (get_size(&opt.qth_max, *argv)) {
  66                                 fprintf(stderr, "Illegal \"max\"\n");
  67                                 return -1;
  68                         }
  69                 } else if (strcmp(*argv, "burst") == 0) {
  70                         NEXT_ARG();
  71                         if (get_unsigned(&burst, *argv, 0)) {
  72                                 fprintf(stderr, "Illegal \"burst\"\n");
  73                                 return -1;
  74                         }
  75                 } else if (strcmp(*argv, "avpkt") == 0) {
  76                         NEXT_ARG();
  77                         if (get_size(&avpkt, *argv)) {
  78                                 fprintf(stderr, "Illegal \"avpkt\"\n");
  79                                 return -1;
  80                         }
  81                 } else if (strcmp(*argv, "probability") == 0) {
  82                         NEXT_ARG();
  83                         if (sscanf(*argv, "%lg", &probability) != 1) {
  84                                 fprintf(stderr, "Illegal \"probability\"\n");
  85                                 return -1;
  86                         }
  87                 } else if (strcmp(*argv, "bandwidth") == 0) {
  88                         NEXT_ARG();
  89                         if (get_rate(&rate, *argv)) {
  90                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
  91                                 return -1;
  92                         }
  93                 } else if (strcmp(*argv, "ecn") == 0) {
  94                         ecn_ok = 1;
  95                 } else if (strcmp(*argv, "help") == 0) {
  96                         explain();
  97                         return -1;
  98                 } else {
  99                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 100                         explain();
 101                         return -1;
 102                 }
 103                 argc--; argv++;
 104         }
 105
 106         if (rate == 0)
 107                 get_rate(&rate, "10Mbit");
 108
 109         if (!opt.qth_min || !opt.qth_max || !burst || !opt.limit || !avpkt) {
 110                 fprintf(stderr, "Required parameter (min, max, burst, limit, avpkt) is missing\n");
 111                 return -1;
 112         }
 113
 114         if ((wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 115                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 116                 return -1;
 117         }
 118         if (wlog >= 10)
 119                 fprintf(stderr, "RED: WARNING. Burst %d seems to be to large.\n", burst);
 120         opt.Wlog = wlog;
 121         if ((wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 122                 fprintf(stderr, "RED: failed to calculate probability.\n");
 123                 return -1;
 124         }
 125         opt.Plog = wlog;
 126         if ((wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 127                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 128                 return -1;
 129         }
 130         opt.Scell_log = wlog;
 131         if (ecn_ok) {
 132 #ifdef TC_RED_ECN
 133                 opt.flags |= TC_RED_ECN;
 134 #else
 135                 fprintf(stderr, "RED: ECN support is missing in this binary.\n");
 136                 return -1;
 137 #endif
 138         }
 139
 140         tail = NLMSG_TAIL(n);
 141         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 142         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 143         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 144         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 145         return 0;
 146 }
 147
 148 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 149 {
 150         struct rtattr *tb[TCA_RED_STAB+1];
 151         struct tc_red_qopt *qopt;
 152         SPRINT_BUF(b1);
 153         SPRINT_BUF(b2);
 154         SPRINT_BUF(b3);
 155
 156         if (opt == NULL)
 157                 return 0;
 158
 159         parse_rtattr_nested(tb, TCA_RED_STAB, opt);
 160
 161         if (tb[TCA_RED_PARMS] == NULL)
 162                 return -1;
 163         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 164         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 165                 return -1;
 166         fprintf(f, "limit %s min %s max %s ",
 167                 sprint_size(qopt->limit, b1),
 168                 sprint_size(qopt->qth_min, b2),
 169                 sprint_size(qopt->qth_max, b3));
 170 #ifdef TC_RED_ECN
 171         if (qopt->flags & TC_RED_ECN)
 172                 fprintf(f, "ecn ");
 173 #endif
 174         if (show_details) {
 175                 fprintf(f, "ewma %u Plog %u Scell_log %u",
 176                         qopt->Wlog, qopt->Plog, qopt->Scell_log);
 177         }
 178         return 0;
 179 }
 180
 181 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 182 {
 183 #ifdef TC_RED_ECN
 184         struct tc_red_xstats *st;
 185
 186         if (xstats == NULL)
 187                 return 0;
 188
 189         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 190                 return -1;
 191
 192         st = RTA_DATA(xstats);
 193         fprintf(f, "  marked %u early %u pdrop %u other %u",
 194                 st->marked, st->early, st->pdrop, st->other);
 195         return 0;
 196
 197 #endif
 198         return 0;
 199 }
 200
 201
 202 struct qdisc_util red_qdisc_util = {
 203         .id             = "red",
 204         .parse_qopt     = red_parse_opt,
 205         .print_qopt     = red_print_opt,
 206         .print_xstats   = red_print_xstats,
 207 };