release/src/router/iptables/extensions/libipt_connrate.c

   1 /* Shared library add-on to iptables to add connection rate tracking
   2  * support.
   3  *
   4  * Copyright (c) 2004 Nuutti Kotivuori <naked@iki.fi>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  **/
  10 #include <stdio.h>
  11 #include <netdb.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <getopt.h>
  15 #include <iptables.h>
  16 #include <linux/netfilter/nf_conntrack_common.h>
  17 #include <linux/netfilter_ipv4/ipt_connrate.h>
  18
  19 /* Function which prints out usage message. */
  20 static void
  21 help(void)
  22 {
  23         printf(
  24 "connrate v%s options:\n"
  25 " --connrate [!] [from]:[to]\n"
  26 "                               Match connection transfer rate in bytes\n"
  27 "                               per second. `inf' can be used for maximum\n"
  28 "                               expressible value.\n"
  29 "\n", IPTABLES_VERSION);
  30 }
  31
  32 static struct option opts[] = {
  33         { "connrate", 1, 0, '1' },
  34         {0}
  35 };
  36
  37 static u_int32_t
  38 parse_value(const char *arg, u_int32_t def)
  39 {
  40         char *end;
  41         size_t len;
  42         u_int32_t value;
  43
  44         len = strlen(arg);
  45         if(len == 0)
  46                 return def;
  47         if(strcmp(arg, "inf") == 0)
  48                 return 0xFFFFFFFF;
  49         value = strtoul(arg, &end, 0);
  50         if(*end != '\0')
  51                 exit_error(PARAMETER_PROBLEM,
  52                            "Bad value in range `%s'", arg);
  53         return value;
  54 }
  55
  56 static void
  57 parse_range(const char *arg, struct ipt_connrate_info *si)
  58 {
  59         char *buffer;
  60         char *colon;
  61
  62         buffer = strdup(arg);
  63         if ((colon = strchr(buffer, ':')) == NULL)
  64                 exit_error(PARAMETER_PROBLEM, "Bad range `%s'", arg);
  65         *colon = '\0';
  66         si->from = parse_value(buffer, 0);
  67         si->to = parse_value(colon+1, 0xFFFFFFFF);
  68         if (si->from > si->to)
  69                 exit_error(PARAMETER_PROBLEM, "%u should be less than %u", si->from,si->to);
  70         free(buffer);
  71 }
  72
  73 #define CONNRATE_OPT 0x01
  74
  75 /* Function which parses command options; returns true if it
  76    ate an option */
  77 static int
  78 parse(int c, char **argv, int invert, unsigned int *flags,
  79       const struct ipt_entry *entry,
  80       unsigned int *nfcache,
  81       struct ipt_entry_match **match)
  82 {
  83         struct ipt_connrate_info *sinfo = (struct ipt_connrate_info *)(*match)->data;
  84         u_int32_t tmp;
  85
  86         switch (c) {
  87         case '1':
  88                 if (*flags & CONNRATE_OPT)
  89                         exit_error(PARAMETER_PROBLEM,
  90                                    "Only one `--connrate' allowed");
  91                 check_inverse(optarg, &invert, &optind, 0);
  92                 parse_range(argv[optind-1], sinfo);
  93                 if (invert) {
  94                         tmp = sinfo->from;
  95                         sinfo->from = sinfo->to;
  96                         sinfo->to = tmp;
  97                 }
  98                 *flags |= CONNRATE_OPT;
  99                 break;
 100
 101         default:
 102                 return 0;
 103         }
 104
 105         return 1;
 106 }
 107
 108 static void final_check(unsigned int flags)
 109 {
 110         if (!(flags & CONNRATE_OPT))
 111                 exit_error(PARAMETER_PROBLEM,
 112                            "connrate match: You must specify `--connrate'");
 113 }
 114
 115 static void
 116 print_value(u_int32_t value)
 117 {
 118         if(value == 0xFFFFFFFF)
 119                 printf("inf");
 120         else
 121                 printf("%u", value);
 122 }
 123
 124 static void
 125 print_range(struct ipt_connrate_info *sinfo)
 126 {
 127         if (sinfo->from > sinfo->to) {
 128                 printf("! ");
 129                 print_value(sinfo->to);
 130                 printf(":");
 131                 print_value(sinfo->from);
 132         } else {
 133                 print_value(sinfo->from);
 134                 printf(":");
 135                 print_value(sinfo->to);
 136         }
 137 }
 138
 139 /* Prints out the matchinfo. */
 140 static void
 141 print(const struct ipt_ip *ip,
 142       const struct ipt_entry_match *match,
 143       int numeric)
 144 {
 145         struct ipt_connrate_info *sinfo = (struct ipt_connrate_info *)match->data;
 146
 147         printf("connrate ");
 148         print_range(sinfo);
 149         printf(" ");
 150 }
 151
 152 /* Saves the matchinfo in parsable form to stdout. */
 153 static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 154 {
 155         struct ipt_connrate_info *sinfo = (struct ipt_connrate_info *)match->data;
 156
 157         printf("--connrate ");
 158         print_range(sinfo);
 159         printf(" ");
 160 }
 161
 162 static struct iptables_match state = {
 163         .next           = NULL,
 164         .name           = "connrate",
 165         .version        = IPTABLES_VERSION,
 166         .size           = IPT_ALIGN(sizeof(struct ipt_connrate_info)),
 167         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_connrate_info)),
 168         .help           = &help,
 169         .parse          = &parse,
 170         .final_check    = &final_check,
 171         .print          = &print,
 172         .save           = &save,
 173         .extra_opts     = opts
 174 };
 175
 176 void _init(void)
 177 {
 178         register_match(&state);
 179 }