1/*
2 * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2011 Intra2net AG <http://www.intra2net.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 (or any
7 * later at your option) as published by the Free Software Foundation.
8 */
9#include <linux/module.h>
10#include <linux/skbuff.h>
11
12#include <linux/netfilter/x_tables.h>
13#include <linux/netfilter/nfnetlink_acct.h>
14#include <linux/netfilter/xt_nfacct.h>
15
16MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
17MODULE_DESCRIPTION("Xtables: match for the extended accounting infrastructure");
18MODULE_LICENSE("GPL");
19MODULE_ALIAS("ipt_nfacct");
20MODULE_ALIAS("ip6t_nfacct");
21
22static bool nfacct_mt(const struct sk_buff *skb, struct xt_action_param *par)
23{
24	int overquota;
25	const struct xt_nfacct_match_info *info = par->targinfo;
26
27	nfnl_acct_update(skb, info->nfacct);
28
29	overquota = nfnl_acct_overquota(skb, info->nfacct);
30
31	return overquota == NFACCT_UNDERQUOTA ? false : true;
32}
33
34static int
35nfacct_mt_checkentry(const struct xt_mtchk_param *par)
36{
37	struct xt_nfacct_match_info *info = par->matchinfo;
38	struct nf_acct *nfacct;
39
40	nfacct = nfnl_acct_find_get(info->name);
41	if (nfacct == NULL) {
42		pr_info("xt_nfacct: accounting object with name `%s' "
43			"does not exists\n", info->name);
44		return -ENOENT;
45	}
46	info->nfacct = nfacct;
47	return 0;
48}
49
50static void
51nfacct_mt_destroy(const struct xt_mtdtor_param *par)
52{
53	const struct xt_nfacct_match_info *info = par->matchinfo;
54
55	nfnl_acct_put(info->nfacct);
56}
57
58static struct xt_match nfacct_mt_reg __read_mostly = {
59	.name       = "nfacct",
60	.family     = NFPROTO_UNSPEC,
61	.checkentry = nfacct_mt_checkentry,
62	.match      = nfacct_mt,
63	.destroy    = nfacct_mt_destroy,
64	.matchsize  = sizeof(struct xt_nfacct_match_info),
65	.me         = THIS_MODULE,
66};
67
68static int __init nfacct_mt_init(void)
69{
70	return xt_register_match(&nfacct_mt_reg);
71}
72
73static void __exit nfacct_mt_exit(void)
74{
75	xt_unregister_match(&nfacct_mt_reg);
76}
77
78module_init(nfacct_mt_init);
79module_exit(nfacct_mt_exit);
80