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         int ok=0;
  39         struct tc_red_qopt opt;
  40         unsigned burst = 0;
  41         unsigned avpkt = 0;
  42         double probability = 0.02;
  43         unsigned rate = 0;
  44         int ecn_ok = 0;
  45         int wlog;
  46         __u8 sbuf[256];
  47         struct rtattr *tail;
  48
  49         memset(&opt, 0, sizeof(opt));
  50
  51         while (argc > 0) {
  52                 if (strcmp(*argv, "limit") == 0) {
  53                         NEXT_ARG();
  54                         if (get_size(&opt.limit, *argv)) {
  55                                 fprintf(stderr, "Illegal \"limit\"\n");
  56                                 return -1;
  57                         }
  58                         ok++;
  59                 } else if (strcmp(*argv, "min") == 0) {
  60                         NEXT_ARG();
  61                         if (get_size(&opt.qth_min, *argv)) {
  62                                 fprintf(stderr, "Illegal \"min\"\n");
  63                                 return -1;
  64                         }
  65                         ok++;
  66                 } else if (strcmp(*argv, "max") == 0) {
  67                         NEXT_ARG();
  68                         if (get_size(&opt.qth_max, *argv)) {
  69                                 fprintf(stderr, "Illegal \"max\"\n");
  70                                 return -1;
  71                         }
  72                         ok++;
  73                 } else if (strcmp(*argv, "burst") == 0) {
  74                         NEXT_ARG();
  75                         if (get_unsigned(&burst, *argv, 0)) {
  76                                 fprintf(stderr, "Illegal \"burst\"\n");
  77                                 return -1;
  78                         }
  79                         ok++;
  80                 } else if (strcmp(*argv, "avpkt") == 0) {
  81                         NEXT_ARG();
  82                         if (get_size(&avpkt, *argv)) {
  83                                 fprintf(stderr, "Illegal \"avpkt\"\n");
  84                                 return -1;
  85                         }
  86                         ok++;
  87                 } else if (strcmp(*argv, "probability") == 0) {
  88                         NEXT_ARG();
  89                         if (sscanf(*argv, "%lg", &probability) != 1) {
  90                                 fprintf(stderr, "Illegal \"probability\"\n");
  91                                 return -1;
  92                         }
  93                         ok++;
  94                 } else if (strcmp(*argv, "bandwidth") == 0) {
  95                         NEXT_ARG();
  96                         if (get_rate(&rate, *argv)) {
  97                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
  98                                 return -1;
  99                         }
 100                         ok++;
 101                 } else if (strcmp(*argv, "ecn") == 0) {
 102                         ecn_ok = 1;
 103                         ok++;
 104                 } else if (strcmp(*argv, "help") == 0) {
 105                         explain();
 106                         return -1;
 107                 } else {
 108                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 109                         explain();
 110                         return -1;
 111                 }
 112                 argc--; argv++;
 113         }
 114
 115         if (!ok)
 116                 return 0;
 117
 118         if (rate == 0)
 119                 get_rate(&rate, "10Mbit");
 120
 121         if (!opt.qth_min || !opt.qth_max || !burst || !opt.limit || !avpkt) {
 122                 fprintf(stderr, "Required parameter (min, max, burst, limit, avpket) is missing\n");
 123                 return -1;
 124         }
 125
 126         if ((wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 127                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 128                 return -1;
 129         }
 130         if (wlog >= 10)
 131                 fprintf(stderr, "RED: WARNING. Burst %d seems to be to large.\n", burst);
 132         opt.Wlog = wlog;
 133         if ((wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 134                 fprintf(stderr, "RED: failed to calculate probability.\n");
 135                 return -1;
 136         }
 137         opt.Plog = wlog;
 138         if ((wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 139                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 140                 return -1;
 141         }
 142         opt.Scell_log = wlog;
 143         if (ecn_ok) {
 144 #ifdef TC_RED_ECN
 145                 opt.flags |= TC_RED_ECN;
 146 #else
 147                 fprintf(stderr, "RED: ECN support is missing in this binary.\n");
 148                 return -1;
 149 #endif
 150         }
 151
 152         tail = NLMSG_TAIL(n);
 153         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 154         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 155         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 156         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 157         return 0;
 158 }
 159
 160 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 161 {
 162         struct rtattr *tb[TCA_RED_STAB+1];
 163         struct tc_red_qopt *qopt;
 164         SPRINT_BUF(b1);
 165         SPRINT_BUF(b2);
 166         SPRINT_BUF(b3);
 167
 168         if (opt == NULL)
 169                 return 0;
 170
 171         parse_rtattr_nested(tb, TCA_RED_STAB, opt);
 172
 173         if (tb[TCA_RED_PARMS] == NULL)
 174                 return -1;
 175         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 176         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 177                 return -1;
 178         fprintf(f, "limit %s min %s max %s ",
 179                 sprint_size(qopt->limit, b1),
 180                 sprint_size(qopt->qth_min, b2),
 181                 sprint_size(qopt->qth_max, b3));
 182 #ifdef TC_RED_ECN
 183         if (qopt->flags & TC_RED_ECN)
 184                 fprintf(f, "ecn ");
 185 #endif
 186         if (show_details) {
 187                 fprintf(f, "ewma %u Plog %u Scell_log %u",
 188                         qopt->Wlog, qopt->Plog, qopt->Scell_log);
 189         }
 190         return 0;
 191 }
 192
 193 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 194 {
 195 #ifdef TC_RED_ECN
 196         struct tc_red_xstats *st;
 197
 198         if (xstats == NULL)
 199                 return 0;
 200
 201         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 202                 return -1;
 203
 204         st = RTA_DATA(xstats);
 205         fprintf(f, "  marked %u early %u pdrop %u other %u",
 206                 st->marked, st->early, st->pdrop, st->other);
 207         return 0;
 208
 209 #endif
 210         return 0;
 211 }
 212
 213
 214 struct qdisc_util red_qdisc_util = {
 215         .id             = "red",
 216         .parse_qopt     = red_parse_opt,
 217         .print_qopt     = red_print_opt,
 218         .print_xstats   = red_print_xstats,
 219 };