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 <fcntl.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <string.h>
  21 #include <math.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, "               [adaptive] [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,
  36                          struct nlmsghdr *n, const char *dev)
  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 (strchr(*argv, '%')) {
  88                                 if (get_percent_rate(&rate, *argv, dev)) {
  89                                         fprintf(stderr, "Illegal \"bandwidth\"\n");
  90                                         return -1;
  91                                 }
  92                         } else if (get_rate(&rate, *argv)) {
  93                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
  94                                 return -1;
  95                         }
  96                 } else if (strcmp(*argv, "ecn") == 0) {
  97                         opt.flags |= TC_RED_ECN;
  98                 } else if (strcmp(*argv, "harddrop") == 0) {
  99                         opt.flags |= TC_RED_HARDDROP;
 100                 } else if (strcmp(*argv, "adaptative") == 0) {
 101                         opt.flags |= TC_RED_ADAPTATIVE;
 102                 } else if (strcmp(*argv, "adaptive") == 0) {
 103                         opt.flags |= TC_RED_ADAPTATIVE;
 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 (!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 (!rate) {
 130                 get_rate(&rate, "10Mbit");
 131                 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
 132         }
 133         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 134                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 135                 return -1;
 136         }
 137         if (parm >= 10)
 138                 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
 139         opt.Wlog = parm;
 140         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 141                 fprintf(stderr, "RED: failed to calculate probability.\n");
 142                 return -1;
 143         }
 144         opt.Plog = parm;
 145         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 146                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 147                 return -1;
 148         }
 149         opt.Scell_log = parm;
 150
 151         tail = NLMSG_TAIL(n);
 152         addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
 153         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 154         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 155         max_P = probability * pow(2, 32);
 156         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 157         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 158         return 0;
 159 }
 160
 161 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 162 {
 163         struct rtattr *tb[TCA_RED_MAX + 1];
 164         struct tc_red_qopt *qopt;
 165         __u32 max_P = 0;
 166
 167         SPRINT_BUF(b1);
 168         SPRINT_BUF(b2);
 169         SPRINT_BUF(b3);
 170
 171         if (opt == NULL)
 172                 return 0;
 173
 174         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 175
 176         if (tb[TCA_RED_PARMS] == NULL)
 177                 return -1;
 178         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 179         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 180                 return -1;
 181
 182         if (tb[TCA_RED_MAX_P] &&
 183             RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
 184                 max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
 185
 186         fprintf(f, "limit %s min %s max %s ",
 187                 sprint_size(qopt->limit, b1),
 188                 sprint_size(qopt->qth_min, b2),
 189                 sprint_size(qopt->qth_max, b3));
 190         if (qopt->flags & TC_RED_ECN)
 191                 fprintf(f, "ecn ");
 192         if (qopt->flags & TC_RED_HARDDROP)
 193                 fprintf(f, "harddrop ");
 194         if (qopt->flags & TC_RED_ADAPTATIVE)
 195                 fprintf(f, "adaptive ");
 196         if (show_details) {
 197                 fprintf(f, "ewma %u ", qopt->Wlog);
 198                 if (max_P)
 199                         fprintf(f, "probability %lg ", max_P / pow(2, 32));
 200                 else
 201                         fprintf(f, "Plog %u ", qopt->Plog);
 202                 fprintf(f, "Scell_log %u", qopt->Scell_log);
 203         }
 204         return 0;
 205 }
 206
 207 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 208 {
 209 #ifdef TC_RED_ECN
 210         struct tc_red_xstats *st;
 211
 212         if (xstats == NULL)
 213                 return 0;
 214
 215         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 216                 return -1;
 217
 218         st = RTA_DATA(xstats);
 219         fprintf(f, "  marked %u early %u pdrop %u other %u",
 220                 st->marked, st->early, st->pdrop, st->other);
 221         return 0;
 222
 223 #endif
 224         return 0;
 225 }
 226
 227
 228 struct qdisc_util red_qdisc_util = {
 229         .id             = "red",
 230         .parse_qopt     = red_parse_opt,
 231         .print_qopt     = red_print_opt,
 232         .print_xstats   = red_print_xstats,
 233 };