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