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
16MODULE_LICENSE("GPL");
17MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
18MODULE_DESCRIPTION("ip6tables filter table");
19
20#define FILTER_VALID_HOOKS ((1 << NF_IP6_LOCAL_IN) | (1 << NF_IP6_FORWARD) | (1 << NF_IP6_LOCAL_OUT))
21
22static struct
23{
24	struct ip6t_replace repl;
25	struct ip6t_standard entries[3];
26	struct ip6t_error term;
27} initial_table __initdata = {
28	.repl = {
29		.name = "filter",
30		.valid_hooks = FILTER_VALID_HOOKS,
31		.num_entries = 4,
32		.size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
33		.hook_entry = {
34			[NF_IP6_LOCAL_IN] = 0,
35			[NF_IP6_FORWARD] = sizeof(struct ip6t_standard),
36			[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
37		},
38		.underflow = {
39			[NF_IP6_LOCAL_IN] = 0,
40			[NF_IP6_FORWARD] = sizeof(struct ip6t_standard),
41			[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
42		},
43	},
44	.entries = {
45		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
46		IP6T_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
47		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
48	},
49	.term = IP6T_ERROR_INIT,		/* ERROR */
50};
51
52static struct xt_table packet_filter = {
53	.name		= "filter",
54	.valid_hooks	= FILTER_VALID_HOOKS,
55	.lock		= RW_LOCK_UNLOCKED,
56	.me		= THIS_MODULE,
57	.af		= AF_INET6,
58};
59
60/* The work comes in here from netfilter.c. */
61static unsigned int
62ip6t_hook(unsigned int hook,
63	 struct sk_buff **pskb,
64	 const struct net_device *in,
65	 const struct net_device *out,
66	 int (*okfn)(struct sk_buff *))
67{
68	return ip6t_do_table(pskb, hook, in, out, &packet_filter);
69}
70
71static unsigned int
72ip6t_local_out_hook(unsigned int hook,
73		   struct sk_buff **pskb,
74		   const struct net_device *in,
75		   const struct net_device *out,
76		   int (*okfn)(struct sk_buff *))
77{
78
79	return ip6t_do_table(pskb, hook, in, out, &packet_filter);
80}
81
82static struct nf_hook_ops ip6t_ops[] = {
83	{
84		.hook		= ip6t_hook,
85		.owner		= THIS_MODULE,
86		.pf		= PF_INET6,
87		.hooknum	= NF_IP6_LOCAL_IN,
88		.priority	= NF_IP6_PRI_FILTER,
89	},
90	{
91		.hook		= ip6t_hook,
92		.owner		= THIS_MODULE,
93		.pf		= PF_INET6,
94		.hooknum	= NF_IP6_FORWARD,
95		.priority	= NF_IP6_PRI_FILTER,
96	},
97	{
98		.hook		= ip6t_local_out_hook,
99		.owner		= THIS_MODULE,
100		.pf		= PF_INET6,
101		.hooknum	= NF_IP6_LOCAL_OUT,
102		.priority	= NF_IP6_PRI_FILTER,
103	},
104};
105
106/* Default to forward because I got too much mail already. */
107static int forward = NF_ACCEPT;
108module_param(forward, bool, 0000);
109
110static int __init ip6table_filter_init(void)
111{
112	int ret;
113
114	if (forward < 0 || forward > NF_MAX_VERDICT) {
115		printk("iptables forward must be 0 or 1\n");
116		return -EINVAL;
117	}
118
119	/* Entry 1 is the FORWARD hook */
120	initial_table.entries[1].target.verdict = -forward - 1;
121
122	/* Register table */
123	ret = ip6t_register_table(&packet_filter, &initial_table.repl);
124	if (ret < 0)
125		return ret;
126
127	/* Register hooks */
128	ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
129	if (ret < 0)
130		goto cleanup_table;
131
132	return ret;
133
134 cleanup_table:
135	ip6t_unregister_table(&packet_filter);
136	return ret;
137}
138
139static void __exit ip6table_filter_fini(void)
140{
141	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
142	ip6t_unregister_table(&packet_filter);
143}
144
145module_init(ip6table_filter_init);
146module_exit(ip6table_filter_fini);
147