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

   1 /*
   2    Shared library add-on to iptables to add match support for the fuzzy match.
   3
   4    This file is distributed under the terms of the GNU General Public
   5    License (GPL). Copies of the GPL can be obtained from:
   6    ftp://prep.ai.mit.edu/pub/gnu/GPL
   7
   8 2002-08-07 Hime Aguiar e Oliveira Jr. <hime@engineer.com> : Initial version.
   9 2003-06-09 Hime Aguiar e Oliveira Jr. <hime@engineer.com> : Bug corrections in
  10 the save function , thanks to information given by Jean-Francois Patenaude .
  11
  12 */
  13
  14 #include <stdio.h>
  15 #include <netdb.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <syslog.h>
  19 #include <getopt.h>
  20 #include <iptables.h>
  21 #include <linux/netfilter_ipv4/ip_tables.h>
  22 #include <linux/netfilter_ipv4/ipt_fuzzy.h>
  23
  24
  25 static void
  26 help(void)
  27 {
  28         printf(
  29 "fuzzy v%s options:\n"
  30 "                      --lower-limit number (in packets per second)\n"
  31 "                      --upper-limit number\n"
  32 ,IPTABLES_VERSION);
  33 };
  34
  35 static struct option opts[] = {
  36         { "lower-limit", 1 , 0 , '1' } ,
  37         { "upper-limit", 1 , 0 , '2' } ,
  38         { 0 }
  39 };
  40
  41 /* Initialize data structures */
  42 static void
  43 init(struct ipt_entry_match *m, unsigned int *nfcache)
  44 {
  45         struct ipt_fuzzy_info *presentinfo = (struct ipt_fuzzy_info *)(m)->data;
  46
  47         /*
  48          * Default rates ( I'll improve this very soon with something based
  49          * on real statistics of the running machine ) .
  50         */
  51
  52         presentinfo->minimum_rate = 1000;
  53         presentinfo->maximum_rate = 2000;
  54 }
  55
  56 #define IPT_FUZZY_OPT_MINIMUM   0x01
  57 #define IPT_FUZZY_OPT_MAXIMUM   0x02
  58
  59 static int
  60 parse(int c, char **argv, int invert, unsigned int *flags,
  61       const struct ipt_entry *entry,
  62       unsigned int *nfcache,
  63       struct ipt_entry_match **match)
  64 {
  65
  66 struct ipt_fuzzy_info *fuzzyinfo = (struct ipt_fuzzy_info *)(*match)->data;
  67
  68         u_int32_t num;
  69
  70         switch (c) {
  71
  72         case '1':
  73
  74         if (invert)
  75                 exit_error(PARAMETER_PROBLEM,"Can't specify ! --lower-limit");
  76
  77         if (*flags & IPT_FUZZY_OPT_MINIMUM)
  78               exit_error(PARAMETER_PROBLEM,"Can't specify --lower-limit twice");
  79
  80         if (string_to_number(optarg,1,MAXFUZZYRATE,&num) == -1 || num < 1)
  81                         exit_error(PARAMETER_PROBLEM,"BAD --lower-limit");
  82
  83                 fuzzyinfo->minimum_rate = num ;
  84
  85                 *flags |= IPT_FUZZY_OPT_MINIMUM;
  86
  87                 break;
  88
  89         case '2':
  90
  91         if (invert)
  92                 exit_error(PARAMETER_PROBLEM,"Can't specify ! --upper-limit");
  93
  94         if (*flags & IPT_FUZZY_OPT_MAXIMUM)
  95            exit_error(PARAMETER_PROBLEM,"Can't specify --upper-limit twice");
  96
  97         if (string_to_number(optarg,1,MAXFUZZYRATE,&num) == -1 || num < 1)
  98                 exit_error(PARAMETER_PROBLEM,"BAD --upper-limit");
  99
 100                 fuzzyinfo->maximum_rate = num ;
 101
 102                 *flags |= IPT_FUZZY_OPT_MAXIMUM;
 103
 104                 break ;
 105
 106         default:
 107                 return 0;
 108         }
 109         return 1;
 110 }
 111
 112 static void final_check(unsigned int flags)
 113 {
 114 }
 115
 116 static void
 117 print(const struct ipt_ip *ip,
 118       const struct ipt_entry_match *match,
 119       int numeric)
 120 {
 121         const struct ipt_fuzzy_info *fuzzyinfo
 122                 = (const struct ipt_fuzzy_info *)match->data;
 123
 124         printf(" fuzzy: lower limit = %u pps - upper limit = %u pps ",fuzzyinfo->minimum_rate,fuzzyinfo->maximum_rate);
 125
 126 }
 127
 128 /* Saves the union ipt_targinfo in parsable form to stdout. */
 129 static void
 130 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 131 {
 132         const struct ipt_fuzzy_info *fuzzyinfo
 133                 = (const struct ipt_fuzzy_info *)match->data;
 134
 135         printf("--lower-limit %u ",fuzzyinfo->minimum_rate);
 136         printf("--upper-limit %u ",fuzzyinfo->maximum_rate);
 137
 138 }
 139
 140 static struct iptables_match fuzzy_match = {
 141         .next           = NULL,
 142         .name           = "fuzzy",
 143         .version        = IPTABLES_VERSION,
 144         .size           = IPT_ALIGN(sizeof(struct ipt_fuzzy_info)),
 145         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_fuzzy_info)),
 146         .help           = &help,
 147         .init           = &init,
 148         .parse          = &parse,
 149         .final_check    = &final_check,
 150         .print          = &print,
 151         .save           = &save,
 152         .extra_opts     = opts
 153 };
 154
 155 void _init(void)
 156 {
 157         register_match(&fuzzy_match);
 158 }