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
comment_mt(const struct sk_buff * skb,struct xt_action_param * par)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 
comment_mt_init(void)35 static int __init comment_mt_init(void)
36 {
37 	return xt_register_match(&comment_mt_reg);
38 }
39 
comment_mt_exit(void)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);
47