1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
4 *
5 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
6 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
7 */
8
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/netfilter_ipv6/ip6_tables.h>
12#include <linux/slab.h>
13
14MODULE_LICENSE("GPL");
15MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
16MODULE_DESCRIPTION("ip6tables filter table");
17
18#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
19			    (1 << NF_INET_FORWARD) | \
20			    (1 << NF_INET_LOCAL_OUT))
21
22static const struct xt_table packet_filter = {
23	.name		= "filter",
24	.valid_hooks	= FILTER_VALID_HOOKS,
25	.me		= THIS_MODULE,
26	.af		= NFPROTO_IPV6,
27	.priority	= NF_IP6_PRI_FILTER,
28};
29
30static struct nf_hook_ops *filter_ops __read_mostly;
31
32/* Default to forward because I got too much mail already. */
33static bool forward = true;
34module_param(forward, bool, 0000);
35
36static int ip6table_filter_table_init(struct net *net)
37{
38	struct ip6t_replace *repl;
39	int err;
40
41	repl = ip6t_alloc_initial_table(&packet_filter);
42	if (repl == NULL)
43		return -ENOMEM;
44	/* Entry 1 is the FORWARD hook */
45	((struct ip6t_standard *)repl->entries)[1].target.verdict =
46		forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
47
48	err = ip6t_register_table(net, &packet_filter, repl, filter_ops);
49	kfree(repl);
50	return err;
51}
52
53static int __net_init ip6table_filter_net_init(struct net *net)
54{
55	if (!forward)
56		return ip6table_filter_table_init(net);
57
58	return 0;
59}
60
61static void __net_exit ip6table_filter_net_pre_exit(struct net *net)
62{
63	ip6t_unregister_table_pre_exit(net, "filter");
64}
65
66static void __net_exit ip6table_filter_net_exit(struct net *net)
67{
68	ip6t_unregister_table_exit(net, "filter");
69}
70
71static struct pernet_operations ip6table_filter_net_ops = {
72	.init = ip6table_filter_net_init,
73	.pre_exit = ip6table_filter_net_pre_exit,
74	.exit = ip6table_filter_net_exit,
75};
76
77static int __init ip6table_filter_init(void)
78{
79	int ret = xt_register_template(&packet_filter,
80					ip6table_filter_table_init);
81
82	if (ret < 0)
83		return ret;
84
85	filter_ops = xt_hook_ops_alloc(&packet_filter, ip6t_do_table);
86	if (IS_ERR(filter_ops)) {
87		xt_unregister_template(&packet_filter);
88		return PTR_ERR(filter_ops);
89	}
90
91	ret = register_pernet_subsys(&ip6table_filter_net_ops);
92	if (ret < 0) {
93		xt_unregister_template(&packet_filter);
94		kfree(filter_ops);
95		return ret;
96	}
97
98	return ret;
99}
100
101static void __exit ip6table_filter_fini(void)
102{
103	unregister_pernet_subsys(&ip6table_filter_net_ops);
104	xt_unregister_template(&packet_filter);
105	kfree(filter_ops);
106}
107
108module_init(ip6table_filter_init);
109module_exit(ip6table_filter_fini);
110