tc/q_netem.c

   1 /*
   2  * q_netem.c            NETEM.
   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:     Stephen Hemminger <shemminger@osdl.org>
  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
  23 #include "utils.h"
  24 #include "tc_util.h"
  25
  26 static void explain(void)
  27 {
  28         fprintf(stderr,
  29 "Usage: ... netem latency TIME [ jitter TIME ] [ limit PACKETS] \n" \
  30 "                 [ loss PERCENT ] [ duplicate PERCENT ]\n" \
  31 "                 [ gap PACKETS]\n");
  32 }
  33
  34 static void explain1(const char *arg)
  35 {
  36         fprintf(stderr, "Illegal \"%s\"\n", arg);
  37 }
  38
  39 #define usage() return(-1)
  40
  41 static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
  42                            struct nlmsghdr *n)
  43 {
  44         struct tc_netem_qopt opt;
  45         unsigned latency = 0;
  46         int ok = 0;
  47
  48         memset(&opt, 0, sizeof(opt));
  49         opt.limit = 1000;
  50
  51         while (argc > 0) {
  52                 if (matches(*argv, "limit") == 0) {
  53                         NEXT_ARG();
  54                         if (get_size(&opt.limit, *argv)) {
  55                                 explain1("limit");
  56                                 return -1;
  57                         }
  58                         ok++;
  59                 } else if (matches(*argv, "latency") == 0) {
  60                         NEXT_ARG();
  61                         if (get_usecs(&latency, *argv)) {
  62                                 explain1("latency");
  63                                 return -1;
  64                         }
  65                         ok++;
  66                 } else if (matches(*argv, "loss") == 0) {
  67                         NEXT_ARG();
  68                         if (get_percent(&opt.loss, *argv)) {
  69                                 explain1("loss");
  70                                 return -1;
  71                         }
  72                         ok++;
  73                 } else if (matches(*argv, "gap") == 0) {
  74                         NEXT_ARG();
  75                         if (get_u32(&opt.gap, *argv, 0)) {
  76                                 explain1("gap");
  77                                 return -1;
  78                         }
  79                         ok++;
  80                 } else if (matches(*argv, "duplicate") == 0) {
  81                         NEXT_ARG();
  82                         if (get_percent(&opt.duplicate, *argv)) {
  83                                 explain1("duplicate");
  84                                 return -1;
  85                         }
  86                         ok++;
  87                 } else if (matches(*argv, "jitter") == 0) {
  88                         NEXT_ARG();
  89                         if (get_usecs(&opt.jitter, *argv)) {
  90                                 explain1("jitter");
  91                                 return -1;
  92                         }
  93                         ok++;
  94                 } else if (strcmp(*argv, "help") == 0) {
  95                         explain();
  96                         return -1;
  97                 } else {
  98                         fprintf(stderr, "What is \"%s\"?\n", *argv);
  99                         explain();
 100                         return -1;
 101                 }
 102                 argc--; argv++;
 103         }
 104
 105         opt.latency = tc_core_usec2tick(latency);
 106
 107         return ok ? addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) : 0;
 108 }
 109
 110 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 111 {
 112         struct tc_netem_qopt *qopt;
 113         SPRINT_BUF(b1);
 114
 115         if (opt == NULL)
 116                 return 0;
 117
 118         if (RTA_PAYLOAD(opt)  < sizeof(*qopt))
 119                 return -1;
 120
 121         qopt = RTA_DATA(opt);
 122
 123         fprintf(f, "limit %d", qopt->limit);
 124         if (qopt->latency)
 125                 fprintf(f, " latency %s",
 126                         sprint_usecs(tc_core_tick2usec(qopt->latency), b1));
 127         if (qopt->jitter)
 128                 fprintf(f, " jitter %s", sprint_usecs(qopt->jitter, b1));
 129
 130         if (qopt->loss)
 131                 fprintf(f, " loss %s",
 132                         sprint_percent(qopt->loss, b1));
 133         if (qopt->gap)
 134                 fprintf(f, " gap %lu", (unsigned long)qopt->gap);
 135
 136
 137         return 0;
 138 }
 139
 140 static int netem_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 141 {
 142         return 0;
 143 }
 144
 145 struct qdisc_util netem_util = {
 146         .id             = "netem",
 147         .parse_qopt     = netem_parse_opt,
 148         .print_qopt     = netem_print_opt,
 149         .print_xstats   = netem_print_xstats,
 150 };