1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2011 Intra2net AG <https://www.intra2net.com>
5 */
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/module.h>
9#include <linux/skbuff.h>
10
11#include <linux/netfilter/x_tables.h>
12#include <linux/netfilter/nfnetlink_acct.h>
13#include <linux/netfilter/xt_nfacct.h>
14
15MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
16MODULE_DESCRIPTION("Xtables: match for the extended accounting infrastructure");
17MODULE_LICENSE("GPL");
18MODULE_ALIAS("ipt_nfacct");
19MODULE_ALIAS("ip6t_nfacct");
20
21static bool nfacct_mt(const struct sk_buff *skb, struct xt_action_param *par)
22{
23	int overquota;
24	const struct xt_nfacct_match_info *info = par->targinfo;
25
26	nfnl_acct_update(skb, info->nfacct);
27
28	overquota = nfnl_acct_overquota(xt_net(par), info->nfacct);
29
30	return overquota != NFACCT_UNDERQUOTA;
31}
32
33static int
34nfacct_mt_checkentry(const struct xt_mtchk_param *par)
35{
36	struct xt_nfacct_match_info *info = par->matchinfo;
37	struct nf_acct *nfacct;
38
39	nfacct = nfnl_acct_find_get(par->net, info->name);
40	if (nfacct == NULL) {
41		pr_info_ratelimited("accounting object `%s' does not exists\n",
42				    info->name);
43		return -ENOENT;
44	}
45	info->nfacct = nfacct;
46	return 0;
47}
48
49static void
50nfacct_mt_destroy(const struct xt_mtdtor_param *par)
51{
52	const struct xt_nfacct_match_info *info = par->matchinfo;
53
54	nfnl_acct_put(info->nfacct);
55}
56
57static struct xt_match nfacct_mt_reg[] __read_mostly = {
58	{
59		.name       = "nfacct",
60		.revision   = 0,
61		.family     = NFPROTO_UNSPEC,
62		.checkentry = nfacct_mt_checkentry,
63		.match      = nfacct_mt,
64		.destroy    = nfacct_mt_destroy,
65		.matchsize  = sizeof(struct xt_nfacct_match_info),
66		.usersize   = offsetof(struct xt_nfacct_match_info, nfacct),
67		.me         = THIS_MODULE,
68	},
69	{
70		.name       = "nfacct",
71		.revision   = 1,
72		.family     = NFPROTO_UNSPEC,
73		.checkentry = nfacct_mt_checkentry,
74		.match      = nfacct_mt,
75		.destroy    = nfacct_mt_destroy,
76		.matchsize  = sizeof(struct xt_nfacct_match_info_v1),
77		.usersize   = offsetof(struct xt_nfacct_match_info_v1, nfacct),
78		.me         = THIS_MODULE,
79	},
80};
81
82static int __init nfacct_mt_init(void)
83{
84	return xt_register_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
85}
86
87static void __exit nfacct_mt_exit(void)
88{
89	xt_unregister_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
90}
91
92module_init(nfacct_mt_init);
93module_exit(nfacct_mt_exit);
94