[deliverable/linux.git] / net / ipv4 / netfilter / arptable_filter.c

/*
 * Filtering ARP tables module.
 *
 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
 *
 */

#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_arp/arp_tables.h>
#include <linux/slab.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("arptables filter table");

#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
			   (1 << NF_ARP_FORWARD))

static const struct xt_table packet_filter = {
	.name		= "filter",
	.valid_hooks	= FILTER_VALID_HOOKS,
	.me		= THIS_MODULE,
	.af		= NFPROTO_ARP,
	.priority	= NF_IP_PRI_FILTER,
};

/* The work comes in here from netfilter.c */
static unsigned int
arptable_filter_hook(const struct nf_hook_ops *ops, struct sk_buff *skb,
		     const struct net_device *in, const struct net_device *out,
		     int (*okfn)(struct sk_buff *))
{
	const struct net *net = dev_net((in != NULL) ? in : out);

	return arpt_do_table(skb, ops->hooknum, in, out,
			     net->ipv4.arptable_filter);
}

static struct nf_hook_ops *arpfilter_ops __read_mostly;

static int __net_init arptable_filter_net_init(struct net *net)
{
	struct arpt_replace *repl;
	
	repl = arpt_alloc_initial_table(&packet_filter);
	if (repl == NULL)
		return -ENOMEM;
	net->ipv4.arptable_filter =
		arpt_register_table(net, &packet_filter, repl);
	kfree(repl);
	return PTR_ERR_OR_ZERO(net->ipv4.arptable_filter);
}

static void __net_exit arptable_filter_net_exit(struct net *net)
{
	arpt_unregister_table(net->ipv4.arptable_filter);
}

static struct pernet_operations arptable_filter_net_ops = {
	.init = arptable_filter_net_init,
	.exit = arptable_filter_net_exit,
};

static int __init arptable_filter_init(void)
{
	int ret;

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

	arpfilter_ops = xt_hook_link(&packet_filter, arptable_filter_hook);
	if (IS_ERR(arpfilter_ops)) {
		ret = PTR_ERR(arpfilter_ops);
		goto cleanup_table;
	}
	return ret;

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

static void __exit arptable_filter_fini(void)
{
	xt_hook_unlink(&packet_filter, arpfilter_ops);
	unregister_pernet_subsys(&arptable_filter_net_ops);
}

module_init(arptable_filter_init);
module_exit(arptable_filter_fini);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Filtering ARP tables module.
	3	*
	4	* Copyright (C) 2002 David S. Miller (davem@redhat.com)
	5	*
	6	*/
	7
	8	#include <linux/module.h>
e3eaa991	9	#include <linux/netfilter/x_tables.h>
1da177e4	10	#include <linux/netfilter_arp/arp_tables.h>
5a0e3ad6	11	#include <linux/slab.h>
1da177e4 LT	12
	13	MODULE_LICENSE("GPL");
	14	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	15	MODULE_DESCRIPTION("arptables filter table");
	16
	17	#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) \| (1 << NF_ARP_OUT) \| \
	18	(1 << NF_ARP_FORWARD))
	19
35aad0ff	20	static const struct xt_table packet_filter = {
1da177e4 LT	21	.name = "filter",
1da177e4 LT	22	.valid_hooks = FILTER_VALID_HOOKS,
1da177e4	23	.me = THIS_MODULE,
ee999d8b	24	.af = NFPROTO_ARP,
2b95efe7	25	.priority = NF_IP_PRI_FILTER,
1da177e4 LT	26	};
	27
	28	/* The work comes in here from netfilter.c */
737535c5	29	static unsigned int
795aa6ef	30	arptable_filter_hook(const struct nf_hook_ops ops, struct sk_buff skb,
737535c5 JE	31	const struct net_device in, const struct net_device out,
737535c5 JE	32	int (okfn)(struct sk_buff ))
1da177e4	33	{
2b21e051	34	const struct net *net = dev_net((in != NULL) ? in : out);
3918fed5	35
795aa6ef PM	36	return arpt_do_table(skb, ops->hooknum, in, out,
795aa6ef PM	37	net->ipv4.arptable_filter);
3918fed5 AD	38	}
3918fed5 AD	39
2b95efe7	40	static struct nf_hook_ops *arpfilter_ops __read_mostly;
1da177e4	41
9ea0cb26 AD	42	static int __net_init arptable_filter_net_init(struct net *net)
9ea0cb26 AD	43	{
e3eaa991 JE	44	struct arpt_replace *repl;
	45
	46	repl = arpt_alloc_initial_table(&packet_filter);
	47	if (repl == NULL)
	48	return -ENOMEM;
9ea0cb26	49	net->ipv4.arptable_filter =
e3eaa991 JE	50	arpt_register_table(net, &packet_filter, repl);
e3eaa991 JE	51	kfree(repl);
8c6ffba0	52	return PTR_ERR_OR_ZERO(net->ipv4.arptable_filter);
9ea0cb26 AD	53	}
	54
	55	static void __net_exit arptable_filter_net_exit(struct net *net)
	56	{
	57	arpt_unregister_table(net->ipv4.arptable_filter);
	58	}
	59
	60	static struct pernet_operations arptable_filter_net_ops = {
	61	.init = arptable_filter_net_init,
	62	.exit = arptable_filter_net_exit,
	63	};
	64
65b4b4e8	65	static int __init arptable_filter_init(void)
1da177e4	66	{
964ddaa1	67	int ret;
1da177e4	68
9ea0cb26 AD	69	ret = register_pernet_subsys(&arptable_filter_net_ops);
	70	if (ret < 0)
	71	return ret;
1da177e4	72
2b95efe7 JE	73	arpfilter_ops = xt_hook_link(&packet_filter, arptable_filter_hook);
	74	if (IS_ERR(arpfilter_ops)) {
	75	ret = PTR_ERR(arpfilter_ops);
964ddaa1	76	goto cleanup_table;
2b95efe7	77	}
1da177e4 LT	78	return ret;
1da177e4 LT	79
964ddaa1	80	cleanup_table:
9ea0cb26	81	unregister_pernet_subsys(&arptable_filter_net_ops);
1da177e4 LT	82	return ret;
	83	}
	84
65b4b4e8	85	static void __exit arptable_filter_fini(void)
1da177e4	86	{
2b95efe7	87	xt_hook_unlink(&packet_filter, arpfilter_ops);
9ea0cb26	88	unregister_pernet_subsys(&arptable_filter_net_ops);
1da177e4 LT	89	}
1da177e4 LT	90
65b4b4e8 AM	91	module_init(arptable_filter_init);
65b4b4e8 AM	92	module_exit(arptable_filter_fini);