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

   1 /* Shared library add-on to iptables to add IP range matching support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <getopt.h>
   7
   8 #include <iptables.h>
   9 #include <linux/netfilter_ipv4/ipt_iprange.h>
  10
  11 /* Function which prints out usage message. */
  12 static void
  13 help(void)
  14 {
  15         printf(
  16 "iprange match v%s options:\n"
  17 "[!] --src-range ip-ip        Match source IP in the specified range\n"
  18 "[!] --dst-range ip-ip        Match destination IP in the specified range\n"
  19 "\n",
  20 IPTABLES_VERSION);
  21 }
  22
  23 static struct option opts[] = {
  24         { "src-range", 1, 0, '1' },
  25         { "dst-range", 1, 0, '2' },
  26         {0}
  27 };
  28
  29 static void
  30 parse_iprange(char *arg, struct ipt_iprange *range)
  31 {
  32         char *dash;
  33         struct in_addr *ip;
  34
  35         dash = strchr(arg, '-');
  36         if (dash)
  37                 *dash = '\0';
  38
  39         ip = dotted_to_addr(arg);
  40         if (!ip)
  41                 exit_error(PARAMETER_PROBLEM, "iprange match: Bad IP address `%s'\n",
  42                            arg);
  43         range->min_ip = ip->s_addr;
  44
  45         if (dash) {
  46                 ip = dotted_to_addr(dash+1);
  47                 if (!ip)
  48                         exit_error(PARAMETER_PROBLEM, "iprange match: Bad IP address `%s'\n",
  49                                    dash+1);
  50                 range->max_ip = ip->s_addr;
  51         } else
  52                 range->max_ip = range->min_ip;
  53 }
  54
  55 /* Function which parses command options; returns true if it
  56    ate an option */
  57 static int
  58 parse(int c, char **argv, int invert, unsigned int *flags,
  59       const struct ipt_entry *entry,
  60       unsigned int *nfcache,
  61       struct ipt_entry_match **match)
  62 {
  63         struct ipt_iprange_info *info = (struct ipt_iprange_info *)(*match)->data;
  64
  65         switch (c) {
  66         case '1':
  67                 if (*flags & IPRANGE_SRC)
  68                         exit_error(PARAMETER_PROBLEM,
  69                                    "iprange match: Only use --src-range ONCE!");
  70                 *flags |= IPRANGE_SRC;
  71
  72                 info->flags |= IPRANGE_SRC;
  73                 check_inverse(optarg, &invert, &optind, 0);
  74                 if (invert) {
  75                         info->flags |= IPRANGE_SRC_INV;
  76                 }
  77                 parse_iprange(optarg, &info->src);
  78
  79                 break;
  80
  81         case '2':
  82                 if (*flags & IPRANGE_DST)
  83                         exit_error(PARAMETER_PROBLEM,
  84                                    "iprange match: Only use --dst-range ONCE!");
  85                 *flags |= IPRANGE_DST;
  86
  87                 info->flags |= IPRANGE_DST;
  88                 check_inverse(optarg, &invert, &optind, 0);
  89                 if (invert)
  90                         info->flags |= IPRANGE_DST_INV;
  91
  92                 parse_iprange(optarg, &info->dst);
  93
  94                 break;
  95
  96         default:
  97                 return 0;
  98         }
  99         return 1;
 100 }
 101
 102 /* Final check; must have specified --src-range or --dst-range. */
 103 static void
 104 final_check(unsigned int flags)
 105 {
 106         if (!flags)
 107                 exit_error(PARAMETER_PROBLEM,
 108                            "iprange match: You must specify `--src-range' or `--dst-range'");
 109 }
 110
 111 static void
 112 print_iprange(const struct ipt_iprange *range)
 113 {
 114         const unsigned char *byte_min, *byte_max;
 115
 116         byte_min = (const unsigned char *) &(range->min_ip);
 117         byte_max = (const unsigned char *) &(range->max_ip);
 118         printf("%d.%d.%d.%d-%d.%d.%d.%d ",
 119                 byte_min[0], byte_min[1], byte_min[2], byte_min[3],
 120                 byte_max[0], byte_max[1], byte_max[2], byte_max[3]);
 121 }
 122
 123 /* Prints out the info. */
 124 static void
 125 print(const struct ipt_ip *ip,
 126       const struct ipt_entry_match *match,
 127       int numeric)
 128 {
 129         struct ipt_iprange_info *info = (struct ipt_iprange_info *)match->data;
 130
 131         if (info->flags & IPRANGE_SRC) {
 132                 printf("source IP range ");
 133                 if (info->flags & IPRANGE_SRC_INV)
 134                         printf("! ");
 135                 print_iprange(&info->src);
 136         }
 137         if (info->flags & IPRANGE_DST) {
 138                 printf("destination IP range ");
 139                 if (info->flags & IPRANGE_DST_INV)
 140                         printf("! ");
 141                 print_iprange(&info->dst);
 142         }
 143 }
 144
 145 /* Saves the union ipt_info in parsable form to stdout. */
 146 static void
 147 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 148 {
 149         struct ipt_iprange_info *info = (struct ipt_iprange_info *)match->data;
 150
 151         if (info->flags & IPRANGE_SRC) {
 152                 if (info->flags & IPRANGE_SRC_INV)
 153                         printf("! ");
 154                 printf("--src-range ");
 155                 print_iprange(&info->src);
 156                 if (info->flags & IPRANGE_DST)
 157                         fputc(' ', stdout);
 158         }
 159         if (info->flags & IPRANGE_DST) {
 160                 if (info->flags & IPRANGE_DST_INV)
 161                         printf("! ");
 162                 printf("--dst-range ");
 163                 print_iprange(&info->dst);
 164         }
 165 }
 166
 167 static struct iptables_match iprange = {
 168         .next           = NULL,
 169         .name           = "iprange",
 170         .version        = IPTABLES_VERSION,
 171         .size           = IPT_ALIGN(sizeof(struct ipt_iprange_info)),
 172         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_iprange_info)),
 173         .help           = &help,
 174         .parse          = &parse,
 175         .final_check    = &final_check,
 176         .print          = &print,
 177         .save           = &save,
 178         .extra_opts     = opts
 179 };
 180
 181 void _init(void)
 182 {
 183         register_match(&iprange);
 184 }