[net-next-2.6.git] / net / ipv4 / netfilter / iptable_security.c

/*
 * "security" table
 *
 * This is for use by Mandatory Access Control (MAC) security models,
 * which need to be able to manage security policy in separate context
 * to DAC.
 *
 * Based on iptable_mangle.c
 *
 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
 * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
 *
 * 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/netfilter_ipv4/ip_tables.h>
#include <net/ip.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
MODULE_DESCRIPTION("iptables security table, for MAC rules");

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

static const struct xt_table security_table = {
	.name		= "security",
	.valid_hooks	= SECURITY_VALID_HOOKS,
	.me		= THIS_MODULE,
	.af		= NFPROTO_IPV4,
	.priority	= NF_IP_PRI_SECURITY,
};

static unsigned int
iptable_security_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)))
		/* Somebody 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_security);
}

static struct nf_hook_ops *sectbl_ops __read_mostly;

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

	repl = ipt_alloc_initial_table(&security_table);
	if (repl == NULL)
		return -ENOMEM;
	net->ipv4.iptable_security =
		ipt_register_table(net, &security_table, repl);
	kfree(repl);
	if (IS_ERR(net->ipv4.iptable_security))
		return PTR_ERR(net->ipv4.iptable_security);

	return 0;
}

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

static struct pernet_operations iptable_security_net_ops = {
	.init = iptable_security_net_init,
	.exit = iptable_security_net_exit,
};

static int __init iptable_security_init(void)
{
	int ret;

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

	sectbl_ops = xt_hook_link(&security_table, iptable_security_hook);
	if (IS_ERR(sectbl_ops)) {
		ret = PTR_ERR(sectbl_ops);
		goto cleanup_table;
	}

	return ret;

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

static void __exit iptable_security_fini(void)
{
	xt_hook_unlink(&security_table, sectbl_ops);
	unregister_pernet_subsys(&iptable_security_net_ops);
}

module_init(iptable_security_init);
module_exit(iptable_security_fini);
Commit	Line	Data
560ee653 JM	1	/*
	2	* "security" table
	3	*
	4	* This is for use by Mandatory Access Control (MAC) security models,
	5	* which need to be able to manage security policy in separate context
	6	* to DAC.
	7	*
	8	* Based on iptable_mangle.c
	9	*
	10	* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
	11	* Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
	12	* Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License version 2 as
	16	* published by the Free Software Foundation.
	17	*/
	18	#include <linux/module.h>
	19	#include <linux/netfilter_ipv4/ip_tables.h>
	20	#include <net/ip.h>
	21
	22	MODULE_LICENSE("GPL");
	23	MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
	24	MODULE_DESCRIPTION("iptables security table, for MAC rules");
	25
	26	#define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) \| \
	27	(1 << NF_INET_FORWARD) \| \
	28	(1 << NF_INET_LOCAL_OUT)
	29
35aad0ff	30	static const struct xt_table security_table = {
560ee653 JM	31	.name = "security",
560ee653 JM	32	.valid_hooks = SECURITY_VALID_HOOKS,
560ee653	33	.me = THIS_MODULE,
f88e6a8a	34	.af = NFPROTO_IPV4,
2b95efe7	35	.priority = NF_IP_PRI_SECURITY,
560ee653 JM	36	};
	37
	38	static unsigned int
737535c5 JE	39	iptable_security_hook(unsigned int hook, struct sk_buff *skb,
	40	const struct net_device *in,
	41	const struct net_device *out,
	42	int (okfn)(struct sk_buff ))
560ee653	43	{
2b21e051	44	const struct net *net;
560ee653	45
2b21e051 JE	46	if (hook == NF_INET_LOCAL_OUT &&
	47	(skb->len < sizeof(struct iphdr) \|\|
	48	ip_hdrlen(skb) < sizeof(struct iphdr)))
	49	/* Somebody is playing with raw sockets. */
	50	return NF_ACCEPT;
560ee653	51
2b21e051 JE	52	net = dev_net((in != NULL) ? in : out);
2b21e051 JE	53	return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_security);
560ee653 JM	54	}
560ee653 JM	55
2b95efe7	56	static struct nf_hook_ops *sectbl_ops __read_mostly;
560ee653 JM	57
	58	static int __net_init iptable_security_net_init(struct net *net)
	59	{
e3eaa991	60	struct ipt_replace *repl;
560ee653	61
e3eaa991 JE	62	repl = ipt_alloc_initial_table(&security_table);
	63	if (repl == NULL)
	64	return -ENOMEM;
	65	net->ipv4.iptable_security =
	66	ipt_register_table(net, &security_table, repl);
	67	kfree(repl);
560ee653 JM	68	if (IS_ERR(net->ipv4.iptable_security))
	69	return PTR_ERR(net->ipv4.iptable_security);
	70
	71	return 0;
	72	}
	73
	74	static void __net_exit iptable_security_net_exit(struct net *net)
	75	{
f54e9367	76	ipt_unregister_table(net, net->ipv4.iptable_security);
560ee653 JM	77	}
	78
	79	static struct pernet_operations iptable_security_net_ops = {
	80	.init = iptable_security_net_init,
	81	.exit = iptable_security_net_exit,
	82	};
	83
	84	static int __init iptable_security_init(void)
	85	{
	86	int ret;
	87
	88	ret = register_pernet_subsys(&iptable_security_net_ops);
	89	if (ret < 0)
	90	return ret;
	91
2b95efe7 JE	92	sectbl_ops = xt_hook_link(&security_table, iptable_security_hook);
	93	if (IS_ERR(sectbl_ops)) {
	94	ret = PTR_ERR(sectbl_ops);
560ee653	95	goto cleanup_table;
2b95efe7	96	}
560ee653 JM	97
	98	return ret;
	99
	100	cleanup_table:
	101	unregister_pernet_subsys(&iptable_security_net_ops);
	102	return ret;
	103	}
	104
	105	static void __exit iptable_security_fini(void)
	106	{
2b95efe7	107	xt_hook_unlink(&security_table, sectbl_ops);
560ee653 JM	108	unregister_pernet_subsys(&iptable_security_net_ops);
	109	}
	110
	111	module_init(iptable_security_init);
	112	module_exit(iptable_security_fini);