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 [ gap PACKETS] \n" \
  30 "                 [ loss PERCENT ] [ duplicate PERCENT ]\n" \
  31 "                 [ rate KBPS ] [ limit BYTES]\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         int ok = 0;
  46
  47         memset(&opt, 0, sizeof(opt));
  48         opt.limit = 1000;
  49
  50         while (argc > 0) {
  51                 if (matches(*argv, "limit") == 0) {
  52                         NEXT_ARG();
  53                         if (get_size(&opt.limit, *argv)) {
  54                                 explain1("limit");
  55                                 return -1;
  56                         }
  57                         ok++;
  58                 } else if (matches(*argv, "latency") == 0) {
  59                         NEXT_ARG();
  60                         if (get_usecs(&opt.latency, *argv)) {
  61                                 explain1("latency");
  62                                 return -1;
  63                         }
  64                         ok++;
  65                 } else if (matches(*argv, "loss") == 0) {
  66                         NEXT_ARG();
  67                         if (get_percent(&opt.loss, *argv)) {
  68                                 explain1("loss");
  69                                 return -1;
  70                         }
  71                         ok++;
  72                 } else if (matches(*argv, "gap") == 0) {
  73                         char *p;
  74                         NEXT_ARG();
  75                         opt.gap = strtoul(*argv, &p, 0);
  76                         if (p == *argv || *p) {
  77                                 explain1("gap");
  78                                 return -1;
  79                         }
  80                         ok++;
  81                 } else if (matches(*argv, "duplicate") == 0) {
  82                         NEXT_ARG();
  83                         if (get_percent(&opt.duplicate, *argv)) {
  84                                 explain1("duplicate");
  85                                 return -1;
  86                         }
  87                         ok++;
  88                 } else if (matches(*argv, "rate") == 0) {
  89                         NEXT_ARG();
  90                         if (get_rate(&opt.rate, *argv)) {
  91                                 explain1("rate");
  92                                 return -1;
  93                         }
  94                         ok++;
  95                 } else if (strcmp(*argv, "help") == 0) {
  96                         explain();
  97                         return -1;
  98                 } else {
  99                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 100                         explain();
 101                         return -1;
 102                 }
 103                 argc--; argv++;
 104         }
 105
 106         if (ok)
 107                 addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
 108         return 0;
 109 }
 110
 111 static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 112 {
 113         struct tc_netem_qopt *qopt;
 114         SPRINT_BUF(b1);
 115         SPRINT_BUF(b2);
 116
 117         if (opt == NULL)
 118                 return 0;
 119
 120         if (RTA_PAYLOAD(opt)  < sizeof(*qopt))
 121                 return -1;
 122
 123         qopt = RTA_DATA(opt);
 124
 125         fprintf(f, "limit %d", qopt->limit);
 126         if (qopt->latency)
 127                 fprintf(f, " latency %s",
 128                         sprint_usecs(qopt->latency, b2));
 129         if (qopt->loss)
 130                 fprintf(f, " loss %s",
 131                         sprint_percent(qopt->loss, b1));
 132         if (qopt->gap)
 133                 fprintf(f, " gap %lu", (unsigned long)qopt->gap);
 134
 135         if (qopt->rate)
 136                 fprintf(f, " rate %s", sprint_rate(qopt->rate, b1));
 137
 138         return 0;
 139 }
 140
 141 static int netem_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
 142 {
 143         return 0;
 144 }
 145
 146 struct qdisc_util netem_util = {
 147         NULL,
 148         "netem",
 149         netem_parse_opt,
 150         netem_print_opt,
 151         netem_print_xstats,
 152 };