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 int burst = 0;
  40         unsigned int avpkt = 0;
  41         double probability = 0.02;
  42         unsigned int rate = 0;
  43         int parm;
  44         __u8 sbuf[256];
  45         __u32 max_P;
  46         struct rtattr *tail;
  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                         opt.flags |= TC_RED_ECN;
  93                 } else if (strcmp(*argv, "harddrop") == 0) {
  94                         opt.flags |= TC_RED_HARDDROP;
  95                 } else if (strcmp(*argv, "adaptative") == 0) {
  96                         opt.flags |= TC_RED_ADAPTATIVE;
  97                 } else if (strcmp(*argv, "adaptive") == 0) {
  98                         opt.flags |= TC_RED_ADAPTATIVE;
  99                 } else if (strcmp(*argv, "help") == 0) {
 100                         explain();
 101                         return -1;
 102                 } else {
 103                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 104                         explain();
 105                         return -1;
 106                 }
 107                 argc--; argv++;
 108         }
 109
 110         if (!opt.limit || !avpkt) {
 111                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 112                 return -1;
 113         }
 114         /* Compute default min/max thresholds based on
 115          * Sally Floyd's recommendations:
 116          * http://www.icir.org/floyd/REDparameters.txt
 117          */
 118         if (!opt.qth_max)
 119                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 120         if (!opt.qth_min)
 121                 opt.qth_min = opt.qth_max / 3;
 122         if (!burst)
 123                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 124         if (!rate) {
 125                 get_rate(&rate, "10Mbit");
 126                 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
 127         }
 128         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 129                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 130                 return -1;
 131         }
 132         if (parm >= 10)
 133                 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
 134         opt.Wlog = parm;
 135         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 136                 fprintf(stderr, "RED: failed to calculate probability.\n");
 137                 return -1;
 138         }
 139         opt.Plog = parm;
 140         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 141                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 142                 return -1;
 143         }
 144         opt.Scell_log = parm;
 145
 146         tail = NLMSG_TAIL(n);
 147         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 148         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 149         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 150         max_P = probability * pow(2, 32);
 151         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 152         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 153         return 0;
 154 }
 155
 156 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 157 {
 158         struct rtattr *tb[TCA_RED_MAX + 1];
 159         struct tc_red_qopt *qopt;
 160         __u32 max_P = 0;
 161
 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 = rta_getattr_u32(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 };