1/*
2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
3 *
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/netfilter_ipv6/ip6_tables.h>
15#include <linux/slab.h>
16
17MODULE_LICENSE("GPL");
18MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
19MODULE_DESCRIPTION("ip6tables filter table");
20
21#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
22			    (1 << NF_INET_FORWARD) | \
23			    (1 << NF_INET_LOCAL_OUT))
24
25static const struct xt_table packet_filter = {
26	.name		= "filter",
27	.valid_hooks	= FILTER_VALID_HOOKS,
28	.me		= THIS_MODULE,
29	.af		= NFPROTO_IPV6,
30	.priority	= NF_IP6_PRI_FILTER,
31};
32
33/* The work comes in here from netfilter.c. */
34static unsigned int
35ip6table_filter_hook(const struct nf_hook_ops *ops, struct sk_buff *skb,
36		     const struct nf_hook_state *state)
37{
38	const struct net *net = dev_net(state->in ? state->in : state->out);
39
40	return ip6t_do_table(skb, ops->hooknum, state, net->ipv6.ip6table_filter);
41}
42
43static struct nf_hook_ops *filter_ops __read_mostly;
44
45/* Default to forward because I got too much mail already. */
46static bool forward = true;
47module_param(forward, bool, 0000);
48
49static int __net_init ip6table_filter_net_init(struct net *net)
50{
51	struct ip6t_replace *repl;
52
53	repl = ip6t_alloc_initial_table(&packet_filter);
54	if (repl == NULL)
55		return -ENOMEM;
56	/* Entry 1 is the FORWARD hook */
57	((struct ip6t_standard *)repl->entries)[1].target.verdict =
58		forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
59
60	net->ipv6.ip6table_filter =
61		ip6t_register_table(net, &packet_filter, repl);
62	kfree(repl);
63	return PTR_ERR_OR_ZERO(net->ipv6.ip6table_filter);
64}
65
66static void __net_exit ip6table_filter_net_exit(struct net *net)
67{
68	ip6t_unregister_table(net, net->ipv6.ip6table_filter);
69}
70
71static struct pernet_operations ip6table_filter_net_ops = {
72	.init = ip6table_filter_net_init,
73	.exit = ip6table_filter_net_exit,
74};
75
76static int __init ip6table_filter_init(void)
77{
78	int ret;
79
80	ret = register_pernet_subsys(&ip6table_filter_net_ops);
81	if (ret < 0)
82		return ret;
83
84	/* Register hooks */
85	filter_ops = xt_hook_link(&packet_filter, ip6table_filter_hook);
86	if (IS_ERR(filter_ops)) {
87		ret = PTR_ERR(filter_ops);
88		goto cleanup_table;
89	}
90
91	return ret;
92
93 cleanup_table:
94	unregister_pernet_subsys(&ip6table_filter_net_ops);
95	return ret;
96}
97
98static void __exit ip6table_filter_fini(void)
99{
100	xt_hook_unlink(&packet_filter, filter_ops);
101	unregister_pernet_subsys(&ip6table_filter_net_ops);
102}
103
104module_init(ip6table_filter_init);
105module_exit(ip6table_filter_fini);
106