net/netfilter/xt_comment.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Implements a dummy match to allow attaching comments to rules
   4  *
   5  * 2003-05-13 Brad Fisher (brad@info-link.net)
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/netfilter/x_tables.h>
  11 #include <linux/netfilter/xt_comment.h>
  12
  13 MODULE_AUTHOR("Brad Fisher <brad@info-link.net>");
  14 MODULE_DESCRIPTION("Xtables: No-op match which can be tagged with a comment");
  15 MODULE_LICENSE("GPL");
  16 MODULE_ALIAS("ipt_comment");
  17 MODULE_ALIAS("ip6t_comment");
  18
  19 static bool
  20 comment_mt(const struct sk_buff *skb, struct xt_action_param *par)
  21 {
  22         /* We always match */
  23         return true;
  24 }
  25
  26 static struct xt_match comment_mt_reg __read_mostly = {
  27         .name      = "comment",
  28         .revision  = 0,
  29         .family    = NFPROTO_UNSPEC,
  30         .match     = comment_mt,
  31         .matchsize = sizeof(struct xt_comment_info),
  32         .me        = THIS_MODULE,
  33 };
  34
  35 static int __init comment_mt_init(void)
  36 {
  37         return xt_register_match(&comment_mt_reg);
  38 }
  39
  40 static void __exit comment_mt_exit(void)
  41 {
  42         xt_unregister_match(&comment_mt_reg);
  43 }
  44
  45 module_init(comment_mt_init);
  46 module_exit(comment_mt_exit);