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

   1 /* Shared library add-on to iptables to add MAC address support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <getopt.h>
   7 #if defined(__GLIBC__) && __GLIBC__ == 2
   8 #include <net/ethernet.h>
   9 #else
  10 #include <linux/if_ether.h>
  11 #endif
  12 #include <iptables.h>
  13 #include <linux/netfilter_ipv4/ipt_mac.h>
  14
  15 /* Function which prints out usage message. */
  16 static void
  17 help(void)
  18 {
  19         printf(
  20 "MAC v%s options:\n"
  21 " --mac-source [!] XX:XX:XX:XX:XX:XX\n"
  22 "                               Match source MAC address\n"
  23 "\n", IPTABLES_VERSION);
  24 }
  25
  26 static struct option opts[] = {
  27         { "mac-source", 1, 0, '1' },
  28         {0}
  29 };
  30
  31 static void
  32 parse_mac(const char *mac, struct ipt_mac_info *info)
  33 {
  34         unsigned int i = 0;
  35
  36         if (strlen(mac) != ETH_ALEN*3-1)
  37                 exit_error(PARAMETER_PROBLEM, "Bad mac address `%s'", mac);
  38
  39         for (i = 0; i < ETH_ALEN; i++) {
  40                 long number;
  41                 char *end;
  42
  43                 number = strtol(mac + i*3, &end, 16);
  44
  45                 if (end == mac + i*3 + 2
  46                     && number >= 0
  47                     && number <= 255)
  48                         info->srcaddr[i] = number;
  49                 else
  50                         exit_error(PARAMETER_PROBLEM,
  51                                    "Bad mac address `%s'", mac);
  52         }
  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_mac_info *macinfo = (struct ipt_mac_info *)(*match)->data;
  64
  65         switch (c) {
  66         case '1':
  67                 check_inverse(optarg, &invert, &optind, 0);
  68                 parse_mac(argv[optind-1], macinfo);
  69                 if (invert)
  70                         macinfo->invert = 1;
  71                 *flags = 1;
  72                 break;
  73
  74         default:
  75                 return 0;
  76         }
  77
  78         return 1;
  79 }
  80
  81 static void print_mac(unsigned char macaddress[ETH_ALEN])
  82 {
  83         unsigned int i;
  84
  85         printf("%02X", macaddress[0]);
  86         for (i = 1; i < ETH_ALEN; i++)
  87                 printf(":%02X", macaddress[i]);
  88         printf(" ");
  89 }
  90
  91 /* Final check; must have specified --mac. */
  92 static void final_check(unsigned int flags)
  93 {
  94         if (!flags)
  95                 exit_error(PARAMETER_PROBLEM,
  96                            "You must specify `--mac-source'");
  97 }
  98
  99 /* Prints out the matchinfo. */
 100 static void
 101 print(const struct ipt_ip *ip,
 102       const struct ipt_entry_match *match,
 103       int numeric)
 104 {
 105         printf("MAC ");
 106
 107         if (((struct ipt_mac_info *)match->data)->invert)
 108                 printf("! ");
 109
 110         print_mac(((struct ipt_mac_info *)match->data)->srcaddr);
 111 }
 112
 113 /* Saves the union ipt_matchinfo in parsable form to stdout. */
 114 static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 115 {
 116         if (((struct ipt_mac_info *)match->data)->invert)
 117                 printf("! ");
 118
 119         printf("--mac-source ");
 120         print_mac(((struct ipt_mac_info *)match->data)->srcaddr);
 121 }
 122
 123 static struct iptables_match mac = {
 124         .next           = NULL,
 125         .name           = "mac",
 126         .version        = IPTABLES_VERSION,
 127         .size           = IPT_ALIGN(sizeof(struct ipt_mac_info)),
 128         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_mac_info)),
 129         .help           = &help,
 130         .parse          = &parse,
 131         .final_check    = &final_check,
 132         .print          = &print,
 133         .save           = &save,
 134         .extra_opts     = opts
 135 };
 136
 137 void _init(void)
 138 {
 139         register_match(&mac);
 140 }