net/netfilter/xt_comment.c

   1 /*
   2  * Implements a dummy match to allow attaching comments to rules
   3  *
   4  * 2003-05-13 Brad Fisher (brad@info-link.net)
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/skbuff.h>
   9 #include <linux/netfilter/x_tables.h>
  10 #include <linux/netfilter/xt_comment.h>
  11
  12 MODULE_AUTHOR("Brad Fisher <brad@info-link.net>");
  13 MODULE_DESCRIPTION("iptables comment match module");
  14 MODULE_LICENSE("GPL");
  15 MODULE_ALIAS("ipt_comment");
  16 MODULE_ALIAS("ip6t_comment");
  17
  18 static int
  19 match(const struct sk_buff *skb,
  20       const struct net_device *in,
  21       const struct net_device *out,
  22       const struct xt_match *match,
  23       const void *matchinfo,
  24       int offset,
  25       unsigned int protooff,
  26       int *hotdrop)
  27 {
  28         /* We always match */
  29         return 1;
  30 }
  31
  32 static struct xt_match comment_match = {
  33         .name           = "comment",
  34         .match          = match,
  35         .matchsize      = sizeof(struct xt_comment_info),
  36         .family         = AF_INET,
  37         .me             = THIS_MODULE
  38 };
  39
  40 static struct xt_match comment6_match = {
  41         .name           = "comment",
  42         .match          = match,
  43         .matchsize      = sizeof(struct xt_comment_info),
  44         .family         = AF_INET6,
  45         .me             = THIS_MODULE
  46 };
  47
  48 static int __init xt_comment_init(void)
  49 {
  50         int ret;
  51
  52         ret = xt_register_match(&comment_match);
  53         if (ret)
  54                 return ret;
  55
  56         ret = xt_register_match(&comment6_match);
  57         if (ret)
  58                 xt_unregister_match(&comment_match);
  59
  60         return ret;
  61 }
  62
  63 static void __exit xt_comment_fini(void)
  64 {
  65         xt_unregister_match(&comment_match);
  66         xt_unregister_match(&comment6_match);
  67 }
  68
  69 module_init(xt_comment_init);
  70 module_exit(xt_comment_fini);