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 #include <math.h>
  23
  24 #include "utils.h"
  25 #include "tc_util.h"
  26
  27 #include "tc_red.h"
  28
  29 static void explain(void)
  30 {
  31         fprintf(stderr, "Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n");
  32         fprintf(stderr, "               [adaptive] [probability PROBABILITY] bandwidth KBPS\n");
  33         fprintf(stderr, "               [ecn] [harddrop]\n");
  34 }
  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 wlog;
  44         __u8 sbuf[256];
  45         __u32 max_P;
  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                         opt.flags |= TC_RED_ECN;
  95                 } else if (strcmp(*argv, "harddrop") == 0) {
  96                         opt.flags |= TC_RED_HARDDROP;
  97                 } else if (strcmp(*argv, "adaptative") == 0) {
  98                         opt.flags |= TC_RED_ADAPTATIVE;
  99                 } else if (strcmp(*argv, "adaptive") == 0) {
 100                         opt.flags |= TC_RED_ADAPTATIVE;
 101                 } else if (strcmp(*argv, "help") == 0) {
 102                         explain();
 103                         return -1;
 104                 } else {
 105                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 106                         explain();
 107                         return -1;
 108                 }
 109                 argc--; argv++;
 110         }
 111
 112         if (rate == 0)
 113                 get_rate(&rate, "10Mbit");
 114
 115         if (!opt.limit || !avpkt) {
 116                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 117                 return -1;
 118         }
 119         /* Compute default min/max thresholds based on
 120          * Sally Floyd's recommendations:
 121          * http://www.icir.org/floyd/REDparameters.txt
 122          */
 123         if (!opt.qth_max)
 124                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 125         if (!opt.qth_min)
 126                 opt.qth_min = opt.qth_max / 3;
 127         if (!burst)
 128                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 129         if ((wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 130                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 131                 return -1;
 132         }
 133         if (wlog >= 10)
 134                 fprintf(stderr, "RED: WARNING. Burst %d seems to be too large.\n", burst);
 135         opt.Wlog = wlog;
 136         if ((wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 137                 fprintf(stderr, "RED: failed to calculate probability.\n");
 138                 return -1;
 139         }
 140         opt.Plog = wlog;
 141         if ((wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 142                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 143                 return -1;
 144         }
 145         opt.Scell_log = wlog;
 146
 147         tail = NLMSG_TAIL(n);
 148         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 149         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 150         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 151         max_P = probability * pow(2, 32);
 152         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 153         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 154         return 0;
 155 }
 156
 157 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 158 {
 159         struct rtattr *tb[TCA_RED_MAX + 1];
 160         struct tc_red_qopt *qopt;
 161         __u32 max_P = 0;
 162         SPRINT_BUF(b1);
 163         SPRINT_BUF(b2);
 164         SPRINT_BUF(b3);
 165
 166         if (opt == NULL)
 167                 return 0;
 168
 169         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 170
 171         if (tb[TCA_RED_PARMS] == NULL)
 172                 return -1;
 173         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 174         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 175                 return -1;
 176
 177         if (tb[TCA_RED_MAX_P] &&
 178             RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
 179                 max_P = *(__u32 *)RTA_DATA(tb[TCA_RED_MAX_P]);
 180
 181         fprintf(f, "limit %s min %s max %s ",
 182                 sprint_size(qopt->limit, b1),
 183                 sprint_size(qopt->qth_min, b2),
 184                 sprint_size(qopt->qth_max, b3));
 185         if (qopt->flags & TC_RED_ECN)
 186                 fprintf(f, "ecn ");
 187         if (qopt->flags & TC_RED_HARDDROP)
 188                 fprintf(f, "harddrop ");
 189         if (qopt->flags & TC_RED_ADAPTATIVE)
 190                 fprintf(f, "adaptive ");
 191         if (show_details) {
 192                 fprintf(f, "ewma %u ", qopt->Wlog);
 193                 if (max_P)
 194                         fprintf(f, "probability %lg ", max_P / pow(2, 32));
 195                 else
 196                         fprintf(f, "Plog %u ", qopt->Plog);
 197                 fprintf(f, "Scell_log %u", qopt->Scell_log);
 198         }
 199         return 0;
 200 }
 201
 202 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 203 {
 204 #ifdef TC_RED_ECN
 205         struct tc_red_xstats *st;
 206
 207         if (xstats == NULL)
 208                 return 0;
 209
 210         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 211                 return -1;
 212
 213         st = RTA_DATA(xstats);
 214         fprintf(f, "  marked %u early %u pdrop %u other %u",
 215                 st->marked, st->early, st->pdrop, st->other);
 216         return 0;
 217
 218 #endif
 219         return 0;
 220 }
 221
 222
 223 struct qdisc_util red_qdisc_util = {
 224         .id             = "red",
 225         .parse_qopt     = red_parse_opt,
 226         .print_qopt     = red_print_opt,
 227         .print_xstats   = red_print_xstats,
 228 };