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 #include "tc_qevent.h"
  26
  27 #include "tc_red.h"
  28
  29 static void explain(void)
  30 {
  31         fprintf(stderr,
  32                 "Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n"
  33                 "               [adaptive] [probability PROBABILITY] [bandwidth KBPS]\n"
  34                 "               [ecn] [harddrop] [nodrop]\n"
  35                 "               [qevent early_drop block IDX] [qevent mark block IDX]\n");
  36 }
  37
  38 #define RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
  39
  40 static struct qevent_plain qe_early_drop = {};
  41 static struct qevent_plain qe_mark = {};
  42 static struct qevent_util qevents[] = {
  43         QEVENT("early_drop", plain, &qe_early_drop, TCA_RED_EARLY_DROP_BLOCK),
  44         QEVENT("mark", plain, &qe_mark, TCA_RED_MARK_BLOCK),
  45         {},
  46 };
  47
  48 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
  49                          struct nlmsghdr *n, const char *dev)
  50 {
  51         struct nla_bitfield32 flags_bf = {
  52                 .selector = RED_SUPPORTED_FLAGS,
  53         };
  54         struct tc_red_qopt opt = {};
  55         unsigned int burst = 0;
  56         unsigned int avpkt = 0;
  57         double probability = 0.02;
  58         unsigned int rate = 0;
  59         int parm;
  60         __u8 sbuf[256];
  61         __u32 max_P;
  62         struct rtattr *tail;
  63
  64         qevents_init(qevents);
  65
  66         while (argc > 0) {
  67                 if (strcmp(*argv, "limit") == 0) {
  68                         NEXT_ARG();
  69                         if (get_size(&opt.limit, *argv)) {
  70                                 fprintf(stderr, "Illegal \"limit\"\n");
  71                                 return -1;
  72                         }
  73                 } else if (strcmp(*argv, "min") == 0) {
  74                         NEXT_ARG();
  75                         if (get_size(&opt.qth_min, *argv)) {
  76                                 fprintf(stderr, "Illegal \"min\"\n");
  77                                 return -1;
  78                         }
  79                 } else if (strcmp(*argv, "max") == 0) {
  80                         NEXT_ARG();
  81                         if (get_size(&opt.qth_max, *argv)) {
  82                                 fprintf(stderr, "Illegal \"max\"\n");
  83                                 return -1;
  84                         }
  85                 } else if (strcmp(*argv, "burst") == 0) {
  86                         NEXT_ARG();
  87                         if (get_unsigned(&burst, *argv, 0)) {
  88                                 fprintf(stderr, "Illegal \"burst\"\n");
  89                                 return -1;
  90                         }
  91                 } else if (strcmp(*argv, "avpkt") == 0) {
  92                         NEXT_ARG();
  93                         if (get_size(&avpkt, *argv)) {
  94                                 fprintf(stderr, "Illegal \"avpkt\"\n");
  95                                 return -1;
  96                         }
  97                 } else if (strcmp(*argv, "probability") == 0) {
  98                         NEXT_ARG();
  99                         if (sscanf(*argv, "%lg", &probability) != 1) {
 100                                 fprintf(stderr, "Illegal \"probability\"\n");
 101                                 return -1;
 102                         }
 103                 } else if (strcmp(*argv, "bandwidth") == 0) {
 104                         NEXT_ARG();
 105                         if (strchr(*argv, '%')) {
 106                                 if (get_percent_rate(&rate, *argv, dev)) {
 107                                         fprintf(stderr, "Illegal \"bandwidth\"\n");
 108                                         return -1;
 109                                 }
 110                         } else if (get_rate(&rate, *argv)) {
 111                                 fprintf(stderr, "Illegal \"bandwidth\"\n");
 112                                 return -1;
 113                         }
 114                 } else if (strcmp(*argv, "ecn") == 0) {
 115                         flags_bf.value |= TC_RED_ECN;
 116                 } else if (strcmp(*argv, "harddrop") == 0) {
 117                         flags_bf.value |= TC_RED_HARDDROP;
 118                 } else if (strcmp(*argv, "nodrop") == 0) {
 119                         flags_bf.value |= TC_RED_NODROP;
 120                 } else if (strcmp(*argv, "adaptative") == 0) {
 121                         flags_bf.value |= TC_RED_ADAPTATIVE;
 122                 } else if (strcmp(*argv, "adaptive") == 0) {
 123                         flags_bf.value |= TC_RED_ADAPTATIVE;
 124                 } else if (matches(*argv, "qevent") == 0) {
 125                         NEXT_ARG();
 126                         if (qevent_parse(qevents, &argc, &argv))
 127                                 return -1;
 128                         continue;
 129                 } else if (strcmp(*argv, "help") == 0) {
 130                         explain();
 131                         return -1;
 132                 } else {
 133                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 134                         explain();
 135                         return -1;
 136                 }
 137                 argc--; argv++;
 138         }
 139
 140         if (!opt.limit || !avpkt) {
 141                 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
 142                 return -1;
 143         }
 144         /* Compute default min/max thresholds based on
 145          * Sally Floyd's recommendations:
 146          * http://www.icir.org/floyd/REDparameters.txt
 147          */
 148         if (!opt.qth_max)
 149                 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
 150         if (!opt.qth_min)
 151                 opt.qth_min = opt.qth_max / 3;
 152         if (!burst)
 153                 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
 154         if (!rate) {
 155                 get_rate(&rate, "10Mbit");
 156                 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
 157         }
 158         if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
 159                 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
 160                 return -1;
 161         }
 162         if (parm >= 10)
 163                 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
 164         opt.Wlog = parm;
 165         if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
 166                 fprintf(stderr, "RED: failed to calculate probability.\n");
 167                 return -1;
 168         }
 169         opt.Plog = parm;
 170         if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
 171                 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
 172                 return -1;
 173         }
 174         opt.Scell_log = parm;
 175
 176         tail = addattr_nest(n, 1024, TCA_OPTIONS);
 177         addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
 178         addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
 179         max_P = probability * pow(2, 32);
 180         addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
 181         addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
 182         if (qevents_dump(qevents, n))
 183                 return -1;
 184         addattr_nest_end(n, tail);
 185         return 0;
 186 }
 187
 188 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 189 {
 190         struct rtattr *tb[TCA_RED_MAX + 1];
 191         struct nla_bitfield32 *flags_bf;
 192         struct tc_red_qopt *qopt;
 193         __u32 max_P = 0;
 194
 195         SPRINT_BUF(b1);
 196         SPRINT_BUF(b2);
 197         SPRINT_BUF(b3);
 198
 199         if (opt == NULL)
 200                 return 0;
 201
 202         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 203
 204         if (tb[TCA_RED_PARMS] == NULL)
 205                 return -1;
 206         qopt = RTA_DATA(tb[TCA_RED_PARMS]);
 207         if (RTA_PAYLOAD(tb[TCA_RED_PARMS])  < sizeof(*qopt))
 208                 return -1;
 209
 210         if (tb[TCA_RED_MAX_P] &&
 211             RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
 212                 max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
 213
 214         if (tb[TCA_RED_FLAGS] &&
 215             RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(*flags_bf)) {
 216                 flags_bf = RTA_DATA(tb[TCA_RED_FLAGS]);
 217                 qopt->flags = flags_bf->value;
 218         }
 219
 220         print_uint(PRINT_JSON, "limit", NULL, qopt->limit);
 221         print_string(PRINT_FP, NULL, "limit %s ", sprint_size(qopt->limit, b1));
 222         print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);
 223         print_string(PRINT_FP, NULL, "min %s ", sprint_size(qopt->qth_min, b2));
 224         print_uint(PRINT_JSON, "max", NULL, qopt->qth_max);
 225         print_string(PRINT_FP, NULL, "max %s ", sprint_size(qopt->qth_max, b3));
 226
 227         tc_red_print_flags(qopt->flags);
 228
 229         if (show_details) {
 230                 print_uint(PRINT_ANY, "ewma", "ewma %u ", qopt->Wlog);
 231                 if (max_P)
 232                         print_float(PRINT_ANY, "probability",
 233                                     "probability %lg ", max_P / pow(2, 32));
 234                 else
 235                         print_uint(PRINT_ANY, "Plog", "Plog %u ", qopt->Plog);
 236                 print_uint(PRINT_ANY, "Scell_log", "Scell_log %u",
 237                            qopt->Scell_log);
 238         }
 239
 240         qevents_init(qevents);
 241         if (qevents_read(qevents, tb))
 242                 return -1;
 243         qevents_print(qevents, f);
 244         return 0;
 245 }
 246
 247 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 248 {
 249 #ifdef TC_RED_ECN
 250         struct tc_red_xstats *st;
 251
 252         if (xstats == NULL)
 253                 return 0;
 254
 255         if (RTA_PAYLOAD(xstats) < sizeof(*st))
 256                 return -1;
 257
 258         st = RTA_DATA(xstats);
 259         print_uint(PRINT_ANY, "marked", "  marked %u ", st->marked);
 260         print_uint(PRINT_ANY, "early", "early %u ", st->early);
 261         print_uint(PRINT_ANY, "pdrop", "pdrop %u ", st->pdrop);
 262         print_uint(PRINT_ANY, "other", "other %u ", st->other);
 263 #endif
 264         return 0;
 265 }
 266
 267 static int red_has_block(struct qdisc_util *qu, struct rtattr *opt, __u32 block_idx, bool *p_has)
 268 {
 269         struct rtattr *tb[TCA_RED_MAX + 1];
 270
 271         if (opt == NULL)
 272                 return 0;
 273
 274         parse_rtattr_nested(tb, TCA_RED_MAX, opt);
 275
 276         qevents_init(qevents);
 277         if (qevents_read(qevents, tb))
 278                 return -1;
 279
 280         *p_has = qevents_have_block(qevents, block_idx);
 281         return 0;
 282 }
 283
 284 struct qdisc_util red_qdisc_util = {
 285         .id             = "red",
 286         .parse_qopt     = red_parse_opt,
 287         .print_qopt     = red_print_opt,
 288         .print_xstats   = red_print_xstats,
 289         .has_block      = red_has_block,
 290 };