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

   1 /* Shared library add-on to iptables for the XOR target
   2  * (C) 2000 by Tim Vandermeersch <Tim.Vandermeersch@pandora.be>
   3  * Based on libipt_TTL.c
   4  *
   5  * Version 1.0
   6  *
   7  * This program is distributed under the terms of GNU GPL
   8  */
   9
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <stdlib.h>
  13 #include <getopt.h>
  14 #include <iptables.h>
  15
  16 #include <linux/netfilter_ipv4/ip_tables.h>
  17 #include <linux/netfilter_ipv4/ipt_XOR.h>
  18
  19 #define IPT_KEY_SET             1
  20 #define IPT_BLOCKSIZE_SET       2
  21
  22 static void init(struct ipt_entry_target *t, unsigned int *nfcache)
  23 {
  24 }
  25
  26 static void help(void)
  27 {
  28         printf(
  29                 "XOR target v%s options\n"
  30                 "  --key string           Set key to \"string\"\n"
  31                 "  --block-size           Set block size\n",
  32                 IPTABLES_VERSION);
  33 }
  34
  35 static int parse(int c, char **argv, int invert, unsigned int *flags,
  36                 const struct ipt_entry *entry,
  37                 struct ipt_entry_target **target)
  38 {
  39         struct ipt_XOR_info *info = (struct ipt_XOR_info *) (*target)->data;
  40
  41         if (!optarg)
  42                 exit_error(PARAMETER_PROBLEM, "XOR: too few arguments");
  43
  44         if (check_inverse(optarg, &invert, NULL, 0))
  45                 exit_error(PARAMETER_PROBLEM, "XOR: unexpected '!'");
  46
  47         switch (c) {
  48                 case '1':
  49                         strncpy(info->key, optarg, 30);
  50                         info->key[29] = '\0';
  51                         *flags |= IPT_KEY_SET;
  52                         break;
  53                 case '2':
  54                         info->block_size = atoi(optarg);
  55                         *flags |= IPT_BLOCKSIZE_SET;
  56                         break;
  57                 default:
  58                         return 0;
  59         }
  60
  61         return 1;
  62 }
  63
  64 static void final_check(unsigned int flags)
  65 {
  66         if (!(flags & IPT_KEY_SET))
  67                 exit_error(PARAMETER_PROBLEM, "XOR: You must specify a key");
  68         if (!(flags & IPT_BLOCKSIZE_SET))
  69                 exit_error(PARAMETER_PROBLEM, "XOR: You must specify a block-size");
  70 }
  71
  72 static void save (const struct ipt_ip *ip,
  73                 const struct ipt_entry_target *target)
  74 {
  75         const struct ipt_XOR_info *info = (struct ipt_XOR_info *) target->data;
  76
  77         printf("--key %s ", info->key);
  78         printf("--block-size %u ", info->block_size);
  79 }
  80
  81 static void print (const struct ipt_ip *ip,
  82         const struct ipt_entry_target *target, int numeric)
  83 {
  84         const struct ipt_XOR_info *info = (struct ipt_XOR_info *) target->data;
  85
  86         printf("key: %s ", info->key);
  87         printf("block-size: %u ", info->block_size);
  88 }
  89
  90 static struct option opts[] = {
  91         { "key", 1, 0, '1' },
  92         { "block-size", 1, 0, '2' },
  93         { 0 }
  94 };
  95
  96 static struct iptables_target XOR = {
  97         .next           = NULL,
  98         .name           = "XOR",
  99         .version        = IPTABLES_VERSION,
 100         .size           = IPT_ALIGN(sizeof(struct ipt_XOR_info)),
 101         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_XOR_info)),
 102         .help           = &help,
 103         .init           = &init,
 104         .parse          = &parse,
 105         .final_check    = &final_check,
 106         .print          = &print,
 107         .save           = &save,
 108         .extra_opts     = opts
 109 };
 110
 111 void _init(void)
 112 {
 113         register_target(&XOR);
 114 }