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,
  31                 "Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n"
  32                 "               [adaptive] [probability PROBABILITY] [bandwidth KBPS]\n"
  33                 "               [ecn] [harddrop]\n");
  34 }
  35
  36 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
  37                          struct nlmsghdr *n, const char *dev)
  38 {
  39         struct tc_red_qopt opt = {};
  40         unsigned int burst = 0;
  41         unsigned int avpkt = 0;
  42         double probability = 0.02;
  43         unsigned int rate = 0;
  44         int parm;
  45         __u8 sbuf[256];
  46         __u32 max_P;
  47         struct rtattr *tail;
  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 (strchr(*argv, '%')) {
  89                                 if (get_percent_rate(&rate, *argv, dev)) {
  90                                         fprintf(stderr, "Illegal \"bandwidth\"\n");
  91                                         return -1;
  92                                 }
  93                         } else if (get_rate(&rate, *argv)) {
  94                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
  95                                 return -1;
  96                         }
  97                 } else if (strcmp(*argv, "ecn") == 0) {
  98                         opt.flags |= TC_RED_ECN;
  99                 } else if (strcmp(*argv, "harddrop") == 0) {
 100                         opt.flags |= TC_RED_HARDDROP;
 101                 } else if (strcmp(*argv, "adaptative") == 0) {
 102                         opt.flags |= TC_RED_ADAPTATIVE;
 103                 } else if (strcmp(*argv, "adaptive") == 0) {
 104                         opt.flags |= TC_RED_ADAPTATIVE;
 105                 } else if (strcmp(*argv, "help") == 0) {
 106                         explain();
 107                         return -1;
 108                 } else {
 109                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 110                         explain();
 111                         return -1;
 112                 }
 113                 argc--; argv++;
 114         }
 115
 116         if (!opt.limit || !avpkt) {
 117                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 118                 return -1;
 119         }
 120         /* Compute default min/max thresholds based on
 121          * Sally Floyd's recommendations:
 122          * http://www.icir.org/floyd/REDparameters.txt
 123          */
 124         if (!opt.qth_max)
 125                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 126         if (!opt.qth_min)
 127                 opt.qth_min = opt.qth_max / 3;
 128         if (!burst)
 129                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 130         if (!rate) {
 131                 get_rate(&rate, "10Mbit");
 132                 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
 133         }
 134         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 135                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 136                 return -1;
 137         }
 138         if (parm >= 10)
 139                 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
 140         opt.Wlog = parm;
 141         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 142                 fprintf(stderr, "RED: failed to calculate probability.\n");
 143                 return -1;
 144         }
 145         opt.Plog = parm;
 146         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 147                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 148                 return -1;
 149         }
 150         opt.Scell_log = parm;
 151
 152         tail = addattr_nest(n, 1024, TCA_OPTIONS);
 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         addattr_nest_end(n, 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         print_uint(PRINT_JSON, "limit", NULL, qopt->limit);
 187         print_string(PRINT_FP, NULL, "limit %s ", sprint_size(qopt->limit, b1));
 188         print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);
 189         print_string(PRINT_FP, NULL, "min %s ", sprint_size(qopt->qth_min, b2));
 190         print_uint(PRINT_JSON, "max", NULL, qopt->qth_max);
 191         print_string(PRINT_FP, NULL, "max %s ", sprint_size(qopt->qth_max, b3));
 192
 193         tc_red_print_flags(qopt->flags);
 194
 195         if (show_details) {
 196                 print_uint(PRINT_ANY, "ewma", "ewma %u ", qopt->Wlog);
 197                 if (max_P)
 198                         print_float(PRINT_ANY, "probability",
 199                                     "probability %lg ", max_P / pow(2, 32));
 200                 else
 201                         print_uint(PRINT_ANY, "Plog", "Plog %u ", qopt->Plog);
 202                 print_uint(PRINT_ANY, "Scell_log", "Scell_log %u",
 203                            qopt->Scell_log);
 204         }
 205         return 0;
 206 }
 207
 208 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 209 {
 210 #ifdef TC_RED_ECN
 211         struct tc_red_xstats *st;
 212
 213         if (xstats == NULL)
 214                 return 0;
 215
 216         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 217                 return -1;
 218
 219         st = RTA_DATA(xstats);
 220         print_uint(PRINT_ANY, "marked", "  marked %u ", st->marked);
 221         print_uint(PRINT_ANY, "early", "early %u ", st->early);
 222         print_uint(PRINT_ANY, "pdrop", "pdrop %u ", st->pdrop);
 223         print_uint(PRINT_ANY, "other", "other %u ", st->other);
 224 #endif
 225         return 0;
 226 }
 227
 228
 229 struct qdisc_util red_qdisc_util = {
 230         .id             = "red",
 231         .parse_qopt     = red_parse_opt,
 232         .print_qopt     = red_print_opt,
 233         .print_xstats   = red_print_xstats,
 234 };