[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / netfilter / iptable_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_ipv4/ip_tables.h>
#include <linux/slab.h>
#include <net/ip.h>

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

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

static const struct xt_table packet_filter = {
	.name		= "filter",
	.valid_hooks	= FILTER_VALID_HOOKS,
	.me		= THIS_MODULE,
	.af		= NFPROTO_IPV4,
	.priority	= NF_IP_PRI_FILTER,
};

static unsigned int
iptable_filter_hook(unsigned int hook, struct sk_buff *skb,
		    const struct net_device *in, const struct net_device *out,
		    int (*okfn)(struct sk_buff *))
{
	const struct net *net;

	if (hook == NF_INET_LOCAL_OUT &&
	    (skb->len < sizeof(struct iphdr) ||
	     ip_hdrlen(skb) < sizeof(struct iphdr)))
		/* root is playing with raw sockets. */
		return NF_ACCEPT;

	net = dev_net((in != NULL) ? in : out);
	return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_filter);
}

static struct nf_hook_ops *filter_ops __read_mostly;

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

static int __net_init iptable_filter_net_init(struct net *net)
{
	struct ipt_replace *repl;

	repl = ipt_alloc_initial_table(&packet_filter);
	if (repl == NULL)
		return -ENOMEM;
	/* Entry 1 is the FORWARD hook */
	((struct ipt_standard *)repl->entries)[1].target.verdict =
		-forward - 1;

	net->ipv4.iptable_filter =
		ipt_register_table(net, &packet_filter, repl);
	kfree(repl);
	if (IS_ERR(net->ipv4.iptable_filter))
		return PTR_ERR(net->ipv4.iptable_filter);
	return 0;
}

static void __net_exit iptable_filter_net_exit(struct net *net)
{
	ipt_unregister_table(net, net->ipv4.iptable_filter);
}

static struct pernet_operations iptable_filter_net_ops = {
	.init = iptable_filter_net_init,
	.exit = iptable_filter_net_exit,
};

static int __init iptable_filter_init(void)
{
	int ret;

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

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

	/* Register hooks */
	filter_ops = xt_hook_link(&packet_filter, iptable_filter_hook);
	if (IS_ERR(filter_ops)) {
		ret = PTR_ERR(filter_ops);
		goto cleanup_table;
	}

	return ret;

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

static void __exit iptable_filter_fini(void)
{
	xt_hook_unlink(&packet_filter, filter_ops);
	unregister_pernet_subsys(&iptable_filter_net_ops);
}

module_init(iptable_filter_init);
module_exit(iptable_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
	13	#include <linux/module.h>
	14	#include <linux/moduleparam.h>
	15	#include <linux/netfilter_ipv4/ip_tables.h>
5a0e3ad6	16	#include <linux/slab.h>
c9bdd4b5	17	#include <net/ip.h>
1da177e4 LT	18
	19	MODULE_LICENSE("GPL");
	20	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
	21	MODULE_DESCRIPTION("iptables filter table");
	22
6e23ae2a PM	23	#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) \| \
	24	(1 << NF_INET_FORWARD) \| \
	25	(1 << NF_INET_LOCAL_OUT))
1da177e4	26
35aad0ff	27	static const struct xt_table packet_filter = {
1da177e4 LT	28	.name = "filter",
1da177e4 LT	29	.valid_hooks = FILTER_VALID_HOOKS,
2e4e6a17	30	.me = THIS_MODULE,
f88e6a8a	31	.af = NFPROTO_IPV4,
2b95efe7	32	.priority = NF_IP_PRI_FILTER,
1da177e4 LT	33	};
1da177e4 LT	34
666953df	35	static unsigned int
737535c5 JE	36	iptable_filter_hook(unsigned int hook, struct sk_buff *skb,
	37	const struct net_device in, const struct net_device out,
	38	int (okfn)(struct sk_buff ))
666953df	39	{
2b21e051	40	const struct net *net;
666953df	41
2b21e051 JE	42	if (hook == NF_INET_LOCAL_OUT &&
	43	(skb->len < sizeof(struct iphdr) \|\|
	44	ip_hdrlen(skb) < sizeof(struct iphdr)))
	45	/* root is playing with raw sockets. */
	46	return NF_ACCEPT;
1da177e4	47
2b21e051 JE	48	net = dev_net((in != NULL) ? in : out);
2b21e051 JE	49	return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_filter);
1da177e4 LT	50	}
1da177e4 LT	51
2b95efe7	52	static struct nf_hook_ops *filter_ops __read_mostly;
1da177e4 LT	53
	54	/* Default to forward because I got too much mail already. */
	55	static int forward = NF_ACCEPT;
	56	module_param(forward, bool, 0000);
	57
9335f047 AD	58	static int __net_init iptable_filter_net_init(struct net *net)
9335f047 AD	59	{
e3eaa991 JE	60	struct ipt_replace *repl;
	61
	62	repl = ipt_alloc_initial_table(&packet_filter);
	63	if (repl == NULL)
	64	return -ENOMEM;
	65	/* Entry 1 is the FORWARD hook */
	66	((struct ipt_standard *)repl->entries)[1].target.verdict =
	67	-forward - 1;
	68
9335f047	69	net->ipv4.iptable_filter =
e3eaa991 JE	70	ipt_register_table(net, &packet_filter, repl);
e3eaa991 JE	71	kfree(repl);
9335f047 AD	72	if (IS_ERR(net->ipv4.iptable_filter))
	73	return PTR_ERR(net->ipv4.iptable_filter);
	74	return 0;
	75	}
	76
	77	static void __net_exit iptable_filter_net_exit(struct net *net)
	78	{
f54e9367	79	ipt_unregister_table(net, net->ipv4.iptable_filter);
9335f047 AD	80	}
	81
	82	static struct pernet_operations iptable_filter_net_ops = {
	83	.init = iptable_filter_net_init,
	84	.exit = iptable_filter_net_exit,
	85	};
	86
65b4b4e8	87	static int __init iptable_filter_init(void)
1da177e4 LT	88	{
	89	int ret;
	90
	91	if (forward < 0 \|\| forward > NF_MAX_VERDICT) {
	92	printk("iptables forward must be 0 or 1\n");
	93	return -EINVAL;
	94	}
	95
9335f047 AD	96	ret = register_pernet_subsys(&iptable_filter_net_ops);
	97	if (ret < 0)
	98	return ret;
1da177e4 LT	99
1da177e4 LT	100	/* Register hooks */
2b95efe7 JE	101	filter_ops = xt_hook_link(&packet_filter, iptable_filter_hook);
	102	if (IS_ERR(filter_ops)) {
	103	ret = PTR_ERR(filter_ops);
1da177e4	104	goto cleanup_table;
2b95efe7	105	}
1da177e4	106
1da177e4 LT	107	return ret;
1da177e4 LT	108
1da177e4	109	cleanup_table:
9335f047	110	unregister_pernet_subsys(&iptable_filter_net_ops);
1da177e4 LT	111	return ret;
	112	}
	113
65b4b4e8	114	static void __exit iptable_filter_fini(void)
1da177e4	115	{
2b95efe7	116	xt_hook_unlink(&packet_filter, filter_ops);
9335f047	117	unregister_pernet_subsys(&iptable_filter_net_ops);
1da177e4 LT	118	}
1da177e4 LT	119
65b4b4e8 AM	120	module_init(iptable_filter_init);
65b4b4e8 AM	121	module_exit(iptable_filter_fini);