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] [nodrop]\n");
  34 }
  35
  36 #define RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
  37
  38 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
  39                          struct nlmsghdr *n, const char *dev)
  40 {
  41         struct nla_bitfield32 flags_bf = {
  42                 .selector = RED_SUPPORTED_FLAGS,
  43         };
  44         struct tc_red_qopt opt = {};
  45         unsigned int burst = 0;
  46         unsigned int avpkt = 0;
  47         double probability = 0.02;
  48         unsigned int rate = 0;
  49         int parm;
  50         __u8 sbuf[256];
  51         __u32 max_P;
  52         struct rtattr *tail;
  53
  54         while (argc > 0) {
  55                 if (strcmp(*argv, "limit") == 0) {
  56                         NEXT_ARG();
  57                         if (get_size(&opt.limit, *argv)) {
  58                                 fprintf(stderr, "Illegal \"limit\"\n");
  59                                 return -1;
  60                         }
  61                 } else if (strcmp(*argv, "min") == 0) {
  62                         NEXT_ARG();
  63                         if (get_size(&opt.qth_min, *argv)) {
  64                                 fprintf(stderr, "Illegal \"min\"\n");
  65                                 return -1;
  66                         }
  67                 } else if (strcmp(*argv, "max") == 0) {
  68                         NEXT_ARG();
  69                         if (get_size(&opt.qth_max, *argv)) {
  70                                 fprintf(stderr, "Illegal \"max\"\n");
  71                                 return -1;
  72                         }
  73                 } else if (strcmp(*argv, "burst") == 0) {
  74                         NEXT_ARG();
  75                         if (get_unsigned(&burst, *argv, 0)) {
  76                                 fprintf(stderr, "Illegal \"burst\"\n");
  77                                 return -1;
  78                         }
  79                 } else if (strcmp(*argv, "avpkt") == 0) {
  80                         NEXT_ARG();
  81                         if (get_size(&avpkt, *argv)) {
  82                                 fprintf(stderr, "Illegal \"avpkt\"\n");
  83                                 return -1;
  84                         }
  85                 } else if (strcmp(*argv, "probability") == 0) {
  86                         NEXT_ARG();
  87                         if (sscanf(*argv, "%lg", &probability) != 1) {
  88                                 fprintf(stderr, "Illegal \"probability\"\n");
  89                                 return -1;
  90                         }
  91                 } else if (strcmp(*argv, "bandwidth") == 0) {
  92                         NEXT_ARG();
  93                         if (strchr(*argv, '%')) {
  94                                 if (get_percent_rate(&rate, *argv, dev)) {
  95                                         fprintf(stderr, "Illegal \"bandwidth\"\n");
  96                                         return -1;
  97                                 }
  98                         } else if (get_rate(&rate, *argv)) {
  99                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
 100                                 return -1;
 101                         }
 102                 } else if (strcmp(*argv, "ecn") == 0) {
 103                         flags_bf.value |= TC_RED_ECN;
 104                 } else if (strcmp(*argv, "harddrop") == 0) {
 105                         flags_bf.value |= TC_RED_HARDDROP;
 106                 } else if (strcmp(*argv, "nodrop") == 0) {
 107                         flags_bf.value |= TC_RED_NODROP;
 108                 } else if (strcmp(*argv, "adaptative") == 0) {
 109                         flags_bf.value |= TC_RED_ADAPTATIVE;
 110                 } else if (strcmp(*argv, "adaptive") == 0) {
 111                         flags_bf.value |= TC_RED_ADAPTATIVE;
 112                 } else if (strcmp(*argv, "help") == 0) {
 113                         explain();
 114                         return -1;
 115                 } else {
 116                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 117                         explain();
 118                         return -1;
 119                 }
 120                 argc--; argv++;
 121         }
 122
 123         if (!opt.limit || !avpkt) {
 124                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 125                 return -1;
 126         }
 127         /* Compute default min/max thresholds based on
 128          * Sally Floyd's recommendations:
 129          * http://www.icir.org/floyd/REDparameters.txt
 130          */
 131         if (!opt.qth_max)
 132                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 133         if (!opt.qth_min)
 134                 opt.qth_min = opt.qth_max / 3;
 135         if (!burst)
 136                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 137         if (!rate) {
 138                 get_rate(&rate, "10Mbit");
 139                 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
 140         }
 141         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 142                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 143                 return -1;
 144         }
 145         if (parm >= 10)
 146                 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
 147         opt.Wlog = parm;
 148         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 149                 fprintf(stderr, "RED: failed to calculate probability.\n");
 150                 return -1;
 151         }
 152         opt.Plog = parm;
 153         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 154                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 155                 return -1;
 156         }
 157         opt.Scell_log = parm;
 158
 159         tail = addattr_nest(n, 1024, TCA_OPTIONS);
 160         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 161         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 162         max_P = probability * pow(2, 32);
 163         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 164         addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
 165         addattr_nest_end(n, tail);
 166         return 0;
 167 }
 168
 169 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 170 {
 171         struct rtattr *tb[TCA_RED_MAX + 1];
 172         struct nla_bitfield32 *flags_bf;
 173         struct tc_red_qopt *qopt;
 174         __u32 max_P = 0;
 175
 176         SPRINT_BUF(b1);
 177         SPRINT_BUF(b2);
 178         SPRINT_BUF(b3);
 179
 180         if (opt == NULL)
 181                 return 0;
 182
 183         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 184
 185         if (tb[TCA_RED_PARMS] == NULL)
 186                 return -1;
 187         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 188         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 189                 return -1;
 190
 191         if (tb[TCA_RED_MAX_P] &&
 192             RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
 193                 max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
 194
 195         if (tb[TCA_RED_FLAGS] &&
 196             RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(*flags_bf)) {
 197                 flags_bf = RTA_DATA(tb[TCA_RED_FLAGS]);
 198                 qopt->flags = flags_bf->value;
 199         }
 200
 201         print_uint(PRINT_JSON, "limit", NULL, qopt->limit);
 202         print_string(PRINT_FP, NULL, "limit %s ", sprint_size(qopt->limit, b1));
 203         print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);
 204         print_string(PRINT_FP, NULL, "min %s ", sprint_size(qopt->qth_min, b2));
 205         print_uint(PRINT_JSON, "max", NULL, qopt->qth_max);
 206         print_string(PRINT_FP, NULL, "max %s ", sprint_size(qopt->qth_max, b3));
 207
 208         tc_red_print_flags(qopt->flags);
 209
 210         if (show_details) {
 211                 print_uint(PRINT_ANY, "ewma", "ewma %u ", qopt->Wlog);
 212                 if (max_P)
 213                         print_float(PRINT_ANY, "probability",
 214                                     "probability %lg ", max_P / pow(2, 32));
 215                 else
 216                         print_uint(PRINT_ANY, "Plog", "Plog %u ", qopt->Plog);
 217                 print_uint(PRINT_ANY, "Scell_log", "Scell_log %u",
 218                            qopt->Scell_log);
 219         }
 220         return 0;
 221 }
 222
 223 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 224 {
 225 #ifdef TC_RED_ECN
 226         struct tc_red_xstats *st;
 227
 228         if (xstats == NULL)
 229                 return 0;
 230
 231         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 232                 return -1;
 233
 234         st = RTA_DATA(xstats);
 235         print_uint(PRINT_ANY, "marked", "  marked %u ", st->marked);
 236         print_uint(PRINT_ANY, "early", "early %u ", st->early);
 237         print_uint(PRINT_ANY, "pdrop", "pdrop %u ", st->pdrop);
 238         print_uint(PRINT_ANY, "other", "other %u ", st->other);
 239 #endif
 240         return 0;
 241 }
 242
 243
 244 struct qdisc_util red_qdisc_util = {
 245         .id             = "red",
 246         .parse_qopt     = red_parse_opt,
 247         .print_qopt     = red_print_opt,
 248         .print_xstats   = red_print_xstats,
 249 };