[deliverable/linux.git] / net / ipv6 / netfilter / ip6table_filter.c

/*
 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
 *
 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/netfilter_ipv6/ip6_tables.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("ip6tables filter table");

#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
			    (1 << NF_INET_FORWARD) | \
			    (1 << NF_INET_LOCAL_OUT))

static struct
{
	struct ip6t_replace repl;
	struct ip6t_standard entries[3];
	struct ip6t_error term;
} initial_table __net_initdata = {
	.repl = {
		.name = "filter",
		.valid_hooks = FILTER_VALID_HOOKS,
		.num_entries = 4,
		.size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
		.hook_entry = {
			[NF_INET_LOCAL_IN] = 0,
			[NF_INET_FORWARD] = sizeof(struct ip6t_standard),
			[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
		},
		.underflow = {
			[NF_INET_LOCAL_IN] = 0,
			[NF_INET_FORWARD] = sizeof(struct ip6t_standard),
			[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
		},
	},
	.entries = {
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
	},
	.term = IP6T_ERROR_INIT,		/* ERROR */
};

static struct xt_table packet_filter = {
	.name		= "filter",
	.valid_hooks	= FILTER_VALID_HOOKS,
	.lock		= __RW_LOCK_UNLOCKED(packet_filter.lock),
	.me		= THIS_MODULE,
	.af		= AF_INET6,
};

/* The work comes in here from netfilter.c. */
static unsigned int
ip6t_local_in_hook(unsigned int hook,
		   struct sk_buff *skb,
		   const struct net_device *in,
		   const struct net_device *out,
		   int (*okfn)(struct sk_buff *))
{
	return ip6t_do_table(skb, hook, in, out,
			     dev_net(in)->ipv6.ip6table_filter);
}

static unsigned int
ip6t_forward_hook(unsigned int hook,
		  struct sk_buff *skb,
		  const struct net_device *in,
		  const struct net_device *out,
		  int (*okfn)(struct sk_buff *))
{
	return ip6t_do_table(skb, hook, in, out,
			     dev_net(in)->ipv6.ip6table_filter);
}

static unsigned int
ip6t_local_out_hook(unsigned int hook,
		   struct sk_buff *skb,
		   const struct net_device *in,
		   const struct net_device *out,
		   int (*okfn)(struct sk_buff *))
{
#if 0
	/* root is playing with raw sockets. */
	if (skb->len < sizeof(struct iphdr)
	    || ip_hdrlen(skb) < sizeof(struct iphdr)) {
		if (net_ratelimit())
			printk("ip6t_hook: happy cracking.\n");
		return NF_ACCEPT;
	}
#endif

	return ip6t_do_table(skb, hook, in, out,
			     dev_net(out)->ipv6.ip6table_filter);
}

static struct nf_hook_ops ip6t_ops[] __read_mostly = {
	{
		.hook		= ip6t_local_in_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_INET_LOCAL_IN,
		.priority	= NF_IP6_PRI_FILTER,
	},
	{
		.hook		= ip6t_forward_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_INET_FORWARD,
		.priority	= NF_IP6_PRI_FILTER,
	},
	{
		.hook		= ip6t_local_out_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_INET_LOCAL_OUT,
		.priority	= NF_IP6_PRI_FILTER,
	},
};

/* Default to forward because I got too much mail already. */
static int forward = NF_ACCEPT;
module_param(forward, bool, 0000);

static int __net_init ip6table_filter_net_init(struct net *net)
{
	/* Register table */
	net->ipv6.ip6table_filter =
		ip6t_register_table(net, &packet_filter, &initial_table.repl);
	if (IS_ERR(net->ipv6.ip6table_filter))
		return PTR_ERR(net->ipv6.ip6table_filter);
	return 0;
}

static void __net_exit ip6table_filter_net_exit(struct net *net)
{
	ip6t_unregister_table(net->ipv6.ip6table_filter);
}

static struct pernet_operations ip6table_filter_net_ops = {
	.init = ip6table_filter_net_init,
	.exit = ip6table_filter_net_exit,
};

static int __init ip6table_filter_init(void)
{
	int ret;

	if (forward < 0 || forward > NF_MAX_VERDICT) {
		printk("iptables forward must be 0 or 1\n");
		return -EINVAL;
	}

	/* Entry 1 is the FORWARD hook */
	initial_table.entries[1].target.verdict = -forward - 1;

	ret = register_pernet_subsys(&ip6table_filter_net_ops);
	if (ret < 0)
		return ret;

	/* Register hooks */
	ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
	if (ret < 0)
		goto cleanup_table;

	return ret;

 cleanup_table:
	unregister_pernet_subsys(&ip6table_filter_net_ops);
	return ret;
}

static void __exit ip6table_filter_fini(void)
{
	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
	unregister_pernet_subsys(&ip6table_filter_net_ops);
}

module_init(ip6table_filter_init);
module_exit(ip6table_filter_fini);
Commit	Line	Data
1da177e4 LT	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
	16	MODULE_LICENSE("GPL");
	17	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
	18	MODULE_DESCRIPTION("ip6tables filter table");
	19
6e23ae2a PM	20	#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) \| \
	21	(1 << NF_INET_FORWARD) \| \
	22	(1 << NF_INET_LOCAL_OUT))
1da177e4	23
1da177e4 LT	24	static struct
	25	{
	26	struct ip6t_replace repl;
	27	struct ip6t_standard entries[3];
	28	struct ip6t_error term;
8280aa61	29	} initial_table __net_initdata = {
3c2ad469 PM	30	.repl = {
	31	.name = "filter",
	32	.valid_hooks = FILTER_VALID_HOOKS,
	33	.num_entries = 4,
	34	.size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
	35	.hook_entry = {
6e23ae2a PM	36	[NF_INET_LOCAL_IN] = 0,
	37	[NF_INET_FORWARD] = sizeof(struct ip6t_standard),
	38	[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
3c2ad469 PM	39	},
3c2ad469 PM	40	.underflow = {
6e23ae2a PM	41	[NF_INET_LOCAL_IN] = 0,
	42	[NF_INET_FORWARD] = sizeof(struct ip6t_standard),
	43	[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
3c2ad469 PM	44	},
	45	},
	46	.entries = {
	47	IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
	48	IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
	49	IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
	50	},
	51	.term = IP6T_ERROR_INIT, /* ERROR */
1da177e4 LT	52	};
1da177e4 LT	53
8280aa61	54	static struct xt_table packet_filter = {
1da177e4 LT	55	.name = "filter",
1da177e4 LT	56	.valid_hooks = FILTER_VALID_HOOKS,
fdccecd0	57	.lock = __RW_LOCK_UNLOCKED(packet_filter.lock),
1da177e4	58	.me = THIS_MODULE,
2e4e6a17	59	.af = AF_INET6,
1da177e4 LT	60	};
	61
	62	/* The work comes in here from netfilter.c. */
	63	static unsigned int
43de9dfe AD	64	ip6t_local_in_hook(unsigned int hook,
	65	struct sk_buff *skb,
	66	const struct net_device *in,
	67	const struct net_device *out,
	68	int (okfn)(struct sk_buff ))
	69	{
	70	return ip6t_do_table(skb, hook, in, out,
48dc7865	71	dev_net(in)->ipv6.ip6table_filter);
43de9dfe AD	72	}
	73
	74	static unsigned int
	75	ip6t_forward_hook(unsigned int hook,
	76	struct sk_buff *skb,
	77	const struct net_device *in,
	78	const struct net_device *out,
	79	int (okfn)(struct sk_buff ))
1da177e4	80	{
43de9dfe	81	return ip6t_do_table(skb, hook, in, out,
48dc7865	82	dev_net(in)->ipv6.ip6table_filter);
1da177e4 LT	83	}
	84
	85	static unsigned int
	86	ip6t_local_out_hook(unsigned int hook,
3db05fea	87	struct sk_buff *skb,
1da177e4 LT	88	const struct net_device *in,
	89	const struct net_device *out,
	90	int (okfn)(struct sk_buff ))
	91	{
	92	#if 0
	93	/* root is playing with raw sockets. */
3db05fea HX	94	if (skb->len < sizeof(struct iphdr)
3db05fea HX	95	\|\| ip_hdrlen(skb) < sizeof(struct iphdr)) {
1da177e4 LT	96	if (net_ratelimit())
	97	printk("ip6t_hook: happy cracking.\n");
	98	return NF_ACCEPT;
	99	}
	100	#endif
	101
43de9dfe	102	return ip6t_do_table(skb, hook, in, out,
48dc7865	103	dev_net(out)->ipv6.ip6table_filter);
1da177e4 LT	104	}
1da177e4 LT	105
1999414a	106	static struct nf_hook_ops ip6t_ops[] __read_mostly = {
1da177e4	107	{
43de9dfe	108	.hook = ip6t_local_in_hook,
1da177e4 LT	109	.owner = THIS_MODULE,
1da177e4 LT	110	.pf = PF_INET6,
6e23ae2a	111	.hooknum = NF_INET_LOCAL_IN,
1da177e4 LT	112	.priority = NF_IP6_PRI_FILTER,
	113	},
	114	{
43de9dfe	115	.hook = ip6t_forward_hook,
1da177e4 LT	116	.owner = THIS_MODULE,
1da177e4 LT	117	.pf = PF_INET6,
6e23ae2a	118	.hooknum = NF_INET_FORWARD,
1da177e4 LT	119	.priority = NF_IP6_PRI_FILTER,
	120	},
	121	{
	122	.hook = ip6t_local_out_hook,
	123	.owner = THIS_MODULE,
	124	.pf = PF_INET6,
6e23ae2a	125	.hooknum = NF_INET_LOCAL_OUT,
1da177e4 LT	126	.priority = NF_IP6_PRI_FILTER,
	127	},
	128	};
	129
	130	/* Default to forward because I got too much mail already. */
	131	static int forward = NF_ACCEPT;
	132	module_param(forward, bool, 0000);
	133
8280aa61 AD	134	static int __net_init ip6table_filter_net_init(struct net *net)
	135	{
	136	/* Register table */
	137	net->ipv6.ip6table_filter =
	138	ip6t_register_table(net, &packet_filter, &initial_table.repl);
	139	if (IS_ERR(net->ipv6.ip6table_filter))
	140	return PTR_ERR(net->ipv6.ip6table_filter);
	141	return 0;
	142	}
	143
	144	static void __net_exit ip6table_filter_net_exit(struct net *net)
	145	{
	146	ip6t_unregister_table(net->ipv6.ip6table_filter);
	147	}
	148
	149	static struct pernet_operations ip6table_filter_net_ops = {
	150	.init = ip6table_filter_net_init,
	151	.exit = ip6table_filter_net_exit,
	152	};
	153
65b4b4e8	154	static int __init ip6table_filter_init(void)
1da177e4 LT	155	{
	156	int ret;
	157
	158	if (forward < 0 \|\| forward > NF_MAX_VERDICT) {
	159	printk("iptables forward must be 0 or 1\n");
	160	return -EINVAL;
	161	}
	162
	163	/* Entry 1 is the FORWARD hook */
	164	initial_table.entries[1].target.verdict = -forward - 1;
	165
8280aa61 AD	166	ret = register_pernet_subsys(&ip6table_filter_net_ops);
	167	if (ret < 0)
	168	return ret;
1da177e4 LT	169
1da177e4 LT	170	/* Register hooks */
964ddaa1	171	ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	172	if (ret < 0)
	173	goto cleanup_table;
	174
1da177e4 LT	175	return ret;
1da177e4 LT	176
1da177e4	177	cleanup_table:
8280aa61	178	unregister_pernet_subsys(&ip6table_filter_net_ops);
1da177e4 LT	179	return ret;
	180	}
	181
65b4b4e8	182	static void __exit ip6table_filter_fini(void)
1da177e4	183	{
964ddaa1	184	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
8280aa61	185	unregister_pernet_subsys(&ip6table_filter_net_ops);
1da177e4 LT	186	}
1da177e4 LT	187
65b4b4e8 AM	188	module_init(ip6table_filter_init);
65b4b4e8 AM	189	module_exit(ip6table_filter_fini);