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, "               [adaptative] [probability PROBABILITY] bandwidth KBPS\n");
  32         fprintf(stderr, "               [ecn] [harddrop]\n");
  33 }
  34
  35 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
  36 {
  37         struct tc_red_qopt opt;
  38         unsigned burst = 0;
  39         unsigned avpkt = 0;
  40         double probability = 0.02;
  41         unsigned rate = 0;
  42         int wlog;
  43         __u8 sbuf[256];
  44         __u32 max_P;
  45         struct rtattr *tail;
  46
  47         memset(&opt, 0, sizeof(opt));
  48
  49         while (argc > 0) {
  50                 if (strcmp(*argv, "limit") == 0) {
  51                         NEXT_ARG();
  52                         if (get_size(&opt.limit, *argv)) {
  53                                 fprintf(stderr, "Illegal \"limit\"\n");
  54                                 return -1;
  55                         }
  56                 } else if (strcmp(*argv, "min") == 0) {
  57                         NEXT_ARG();
  58                         if (get_size(&opt.qth_min, *argv)) {
  59                                 fprintf(stderr, "Illegal \"min\"\n");
  60                                 return -1;
  61                         }
  62                 } else if (strcmp(*argv, "max") == 0) {
  63                         NEXT_ARG();
  64                         if (get_size(&opt.qth_max, *argv)) {
  65                                 fprintf(stderr, "Illegal \"max\"\n");
  66                                 return -1;
  67                         }
  68                 } else if (strcmp(*argv, "burst") == 0) {
  69                         NEXT_ARG();
  70                         if (get_unsigned(&burst, *argv, 0)) {
  71                                 fprintf(stderr, "Illegal \"burst\"\n");
  72                                 return -1;
  73                         }
  74                 } else if (strcmp(*argv, "avpkt") == 0) {
  75                         NEXT_ARG();
  76                         if (get_size(&avpkt, *argv)) {
  77                                 fprintf(stderr, "Illegal \"avpkt\"\n");
  78                                 return -1;
  79                         }
  80                 } else if (strcmp(*argv, "probability") == 0) {
  81                         NEXT_ARG();
  82                         if (sscanf(*argv, "%lg", &probability) != 1) {
  83                                 fprintf(stderr, "Illegal \"probability\"\n");
  84                                 return -1;
  85                         }
  86                 } else if (strcmp(*argv, "bandwidth") == 0) {
  87                         NEXT_ARG();
  88                         if (get_rate(&rate, *argv)) {
  89                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
  90                                 return -1;
  91                         }
  92                 } else if (strcmp(*argv, "ecn") == 0) {
  93                         opt.flags |= TC_RED_ECN;
  94                 } else if (strcmp(*argv, "harddrop") == 0) {
  95                         opt.flags |= TC_RED_HARDDROP;
  96                 } else if (strcmp(*argv, "adaptative") == 0) {
  97                         opt.flags |= TC_RED_ADAPTATIVE;
  98                 } else if (strcmp(*argv, "help") == 0) {
  99                         explain();
 100                         return -1;
 101                 } else {
 102                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 103                         explain();
 104                         return -1;
 105                 }
 106                 argc--; argv++;
 107         }
 108
 109         if (rate == 0)
 110                 get_rate(&rate, "10Mbit");
 111
 112         if (!opt.limit || !avpkt) {
 113                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 114                 return -1;
 115         }
 116         /* Compute default min/max thresholds based on
 117          * Sally Floyd's recommendations:
 118          * http://www.icir.org/floyd/REDparameters.txt
 119          */
 120         if (!opt.qth_max)
 121                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 122         if (!opt.qth_min)
 123                 opt.qth_min = opt.qth_max / 3;
 124         if (!burst)
 125                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 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 too 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
 144         tail = NLMSG_TAIL(n);
 145         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 146         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 147         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 148         max_P = probability * pow(2, 32);
 149         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 150         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 151         return 0;
 152 }
 153
 154 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 155 {
 156         struct rtattr *tb[TCA_RED_MAX + 1];
 157         struct tc_red_qopt *qopt;
 158         __u32 max_P = 0;
 159         SPRINT_BUF(b1);
 160         SPRINT_BUF(b2);
 161         SPRINT_BUF(b3);
 162
 163         if (opt == NULL)
 164                 return 0;
 165
 166         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 167
 168         if (tb[TCA_RED_PARMS] == NULL)
 169                 return -1;
 170         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 171         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 172                 return -1;
 173
 174         if (tb[TCA_RED_MAX_P] &&
 175             RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
 176                 max_P = *(__u32 *)RTA_DATA(tb[TCA_RED_MAX_P]);
 177
 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         if (qopt->flags & TC_RED_ECN)
 183                 fprintf(f, "ecn ");
 184         if (qopt->flags & TC_RED_HARDDROP)
 185                 fprintf(f, "harddrop ");
 186         if (qopt->flags & TC_RED_ADAPTATIVE)
 187                 fprintf(f, "adaptative ");
 188         if (show_details) {
 189                 fprintf(f, "ewma %u ", qopt->Wlog);
 190                 if (max_P)
 191                         fprintf(f, "probability %lg ", max_P / pow(2, 32));
 192                 else
 193                         fprintf(f, "Plog %u ", qopt->Plog);
 194                 fprintf(f, "Scell_log %u", qopt->Scell_log);
 195         }
 196         return 0;
 197 }
 198
 199 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 200 {
 201 #ifdef TC_RED_ECN
 202         struct tc_red_xstats *st;
 203
 204         if (xstats == NULL)
 205                 return 0;
 206
 207         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 208                 return -1;
 209
 210         st = RTA_DATA(xstats);
 211         fprintf(f, "  marked %u early %u pdrop %u other %u",
 212                 st->marked, st->early, st->pdrop, st->other);
 213         return 0;
 214
 215 #endif
 216         return 0;
 217 }
 218
 219
 220 struct qdisc_util red_qdisc_util = {
 221         .id             = "red",
 222         .parse_qopt     = red_parse_opt,
 223         .print_qopt     = red_print_opt,
 224         .print_xstats   = red_print_xstats,
 225 };