[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 <linux/slab.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>
5a0e3ad6	20	#include <linux/slab.h>
560ee653 JM	21	#include <net/ip.h>
	22
	23	MODULE_LICENSE("GPL");
	24	MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
	25	MODULE_DESCRIPTION("iptables security table, for MAC rules");
	26
	27	#define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) \| \
	28	(1 << NF_INET_FORWARD) \| \
	29	(1 << NF_INET_LOCAL_OUT)
	30
35aad0ff	31	static const struct xt_table security_table = {
560ee653 JM	32	.name = "security",
560ee653 JM	33	.valid_hooks = SECURITY_VALID_HOOKS,
560ee653	34	.me = THIS_MODULE,
f88e6a8a	35	.af = NFPROTO_IPV4,
2b95efe7	36	.priority = NF_IP_PRI_SECURITY,
560ee653 JM	37	};
	38
	39	static unsigned int
737535c5 JE	40	iptable_security_hook(unsigned int hook, struct sk_buff *skb,
	41	const struct net_device *in,
	42	const struct net_device *out,
	43	int (okfn)(struct sk_buff ))
560ee653	44	{
2b21e051	45	const struct net *net;
560ee653	46
2b21e051 JE	47	if (hook == NF_INET_LOCAL_OUT &&
	48	(skb->len < sizeof(struct iphdr) \|\|
	49	ip_hdrlen(skb) < sizeof(struct iphdr)))
	50	/* Somebody is playing with raw sockets. */
	51	return NF_ACCEPT;
560ee653	52
2b21e051 JE	53	net = dev_net((in != NULL) ? in : out);
2b21e051 JE	54	return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_security);
560ee653 JM	55	}
560ee653 JM	56
2b95efe7	57	static struct nf_hook_ops *sectbl_ops __read_mostly;
560ee653 JM	58
	59	static int __net_init iptable_security_net_init(struct net *net)
	60	{
e3eaa991	61	struct ipt_replace *repl;
560ee653	62
e3eaa991 JE	63	repl = ipt_alloc_initial_table(&security_table);
	64	if (repl == NULL)
	65	return -ENOMEM;
	66	net->ipv4.iptable_security =
	67	ipt_register_table(net, &security_table, repl);
	68	kfree(repl);
560ee653 JM	69	if (IS_ERR(net->ipv4.iptable_security))
	70	return PTR_ERR(net->ipv4.iptable_security);
	71
	72	return 0;
	73	}
	74
	75	static void __net_exit iptable_security_net_exit(struct net *net)
	76	{
f54e9367	77	ipt_unregister_table(net, net->ipv4.iptable_security);
560ee653 JM	78	}
	79
	80	static struct pernet_operations iptable_security_net_ops = {
	81	.init = iptable_security_net_init,
	82	.exit = iptable_security_net_exit,
	83	};
	84
	85	static int __init iptable_security_init(void)
	86	{
	87	int ret;
	88
	89	ret = register_pernet_subsys(&iptable_security_net_ops);
	90	if (ret < 0)
	91	return ret;
	92
2b95efe7 JE	93	sectbl_ops = xt_hook_link(&security_table, iptable_security_hook);
	94	if (IS_ERR(sectbl_ops)) {
	95	ret = PTR_ERR(sectbl_ops);
560ee653	96	goto cleanup_table;
2b95efe7	97	}
560ee653 JM	98
	99	return ret;
	100
	101	cleanup_table:
	102	unregister_pernet_subsys(&iptable_security_net_ops);
	103	return ret;
	104	}
	105
	106	static void __exit iptable_security_fini(void)
	107	{
2b95efe7	108	xt_hook_unlink(&security_table, sectbl_ops);
560ee653 JM	109	unregister_pernet_subsys(&iptable_security_net_ops);
	110	}
	111
	112	module_init(iptable_security_init);
	113	module_exit(iptable_security_fini);