[deliverable/linux.git] / net / ipv6 / netfilter / ip6table_mangle.c

/*
 * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
 *
 * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
 * 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/netfilter_ipv6/ip6_tables.h>

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

#define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) | \
			    (1 << NF_IP6_LOCAL_IN) | \
			    (1 << NF_IP6_FORWARD) | \
			    (1 << NF_IP6_LOCAL_OUT) | \
			    (1 << NF_IP6_POST_ROUTING))

static struct
{
	struct ip6t_replace repl;
	struct ip6t_standard entries[5];
	struct ip6t_error term;
} initial_table __initdata = {
	.repl = {
		.name = "mangle",
		.valid_hooks = MANGLE_VALID_HOOKS,
		.num_entries = 6,
		.size = sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
		.hook_entry = {
			[NF_IP6_PRE_ROUTING] 	= 0,
			[NF_IP6_LOCAL_IN]	= sizeof(struct ip6t_standard),
			[NF_IP6_FORWARD]	= sizeof(struct ip6t_standard) * 2,
			[NF_IP6_LOCAL_OUT] 	= sizeof(struct ip6t_standard) * 3,
			[NF_IP6_POST_ROUTING]	= sizeof(struct ip6t_standard) * 4,
		},
		.underflow = {
			[NF_IP6_PRE_ROUTING] 	= 0,
			[NF_IP6_LOCAL_IN]	= sizeof(struct ip6t_standard),
			[NF_IP6_FORWARD]	= sizeof(struct ip6t_standard) * 2,
			[NF_IP6_LOCAL_OUT] 	= sizeof(struct ip6t_standard) * 3,
			[NF_IP6_POST_ROUTING]	= sizeof(struct ip6t_standard) * 4,
		},
	},
	.entries = {
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* PRE_ROUTING */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
		IP6T_STANDARD_INIT(NF_ACCEPT),	/* POST_ROUTING */
	},
	.term = IP6T_ERROR_INIT,		/* ERROR */
};

static struct xt_table packet_mangler = {
	.name		= "mangle",
	.valid_hooks	= MANGLE_VALID_HOOKS,
	.lock		= RW_LOCK_UNLOCKED,
	.me		= THIS_MODULE,
	.af		= AF_INET6,
};

/* The work comes in here from netfilter.c. */
static unsigned int
ip6t_route_hook(unsigned int hook,
	 struct sk_buff **pskb,
	 const struct net_device *in,
	 const struct net_device *out,
	 int (*okfn)(struct sk_buff *))
{
	return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
}

static unsigned int
ip6t_local_hook(unsigned int hook,
		   struct sk_buff **pskb,
		   const struct net_device *in,
		   const struct net_device *out,
		   int (*okfn)(struct sk_buff *))
{

	unsigned int ret;
	struct in6_addr saddr, daddr;
	u_int8_t hop_limit;
	u_int32_t flowlabel, mark;

#if 0
	/* root is playing with raw sockets. */
	if ((*pskb)->len < sizeof(struct iphdr)
	    || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
		if (net_ratelimit())
			printk("ip6t_hook: happy cracking.\n");
		return NF_ACCEPT;
	}
#endif

	/* save source/dest address, mark, hoplimit, flowlabel, priority,  */
	memcpy(&saddr, &ipv6_hdr(*pskb)->saddr, sizeof(saddr));
	memcpy(&daddr, &ipv6_hdr(*pskb)->daddr, sizeof(daddr));
	mark = (*pskb)->mark;
	hop_limit = ipv6_hdr(*pskb)->hop_limit;

	/* flowlabel and prio (includes version, which shouldn't change either */
	flowlabel = *((u_int32_t *)ipv6_hdr(*pskb));

	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);

	if (ret != NF_DROP && ret != NF_STOLEN
		&& (memcmp(&ipv6_hdr(*pskb)->saddr, &saddr, sizeof(saddr))
		    || memcmp(&ipv6_hdr(*pskb)->daddr, &daddr, sizeof(daddr))
		    || (*pskb)->mark != mark
		    || ipv6_hdr(*pskb)->hop_limit != hop_limit))
		return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;

	return ret;
}

static struct nf_hook_ops ip6t_ops[] = {
	{
		.hook		= ip6t_route_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_IP6_PRE_ROUTING,
		.priority	= NF_IP6_PRI_MANGLE,
	},
	{
		.hook		= ip6t_local_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_IP6_LOCAL_IN,
		.priority	= NF_IP6_PRI_MANGLE,
	},
	{
		.hook		= ip6t_route_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_IP6_FORWARD,
		.priority	= NF_IP6_PRI_MANGLE,
	},
	{
		.hook		= ip6t_local_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_IP6_LOCAL_OUT,
		.priority	= NF_IP6_PRI_MANGLE,
	},
	{
		.hook		= ip6t_route_hook,
		.owner		= THIS_MODULE,
		.pf		= PF_INET6,
		.hooknum	= NF_IP6_POST_ROUTING,
		.priority	= NF_IP6_PRI_MANGLE,
	},
};

static int __init ip6table_mangle_init(void)
{
	int ret;

	/* Register table */
	ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
	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:
	ip6t_unregister_table(&packet_mangler);
	return ret;
}

static void __exit ip6table_mangle_fini(void)
{
	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
	ip6t_unregister_table(&packet_mangler);
}

module_init(ip6table_mangle_init);
module_exit(ip6table_mangle_fini);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
	3	*
	4	* Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
	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.
1da177e4 LT	10	*/
	11	#include <linux/module.h>
	12	#include <linux/netfilter_ipv6/ip6_tables.h>
	13
	14	MODULE_LICENSE("GPL");
	15	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
	16	MODULE_DESCRIPTION("ip6tables mangle table");
	17
	18	#define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) \| \
	19	(1 << NF_IP6_LOCAL_IN) \| \
	20	(1 << NF_IP6_FORWARD) \| \
	21	(1 << NF_IP6_LOCAL_OUT) \| \
	22	(1 << NF_IP6_POST_ROUTING))
	23
1da177e4 LT	24	static struct
	25	{
	26	struct ip6t_replace repl;
	27	struct ip6t_standard entries[5];
	28	struct ip6t_error term;
3c2ad469 PM	29	} initial_table __initdata = {
	30	.repl = {
	31	.name = "mangle",
	32	.valid_hooks = MANGLE_VALID_HOOKS,
	33	.num_entries = 6,
	34	.size = sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
	35	.hook_entry = {
	36	[NF_IP6_PRE_ROUTING] = 0,
	37	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	38	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	39	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	40	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
	41	},
	42	.underflow = {
	43	[NF_IP6_PRE_ROUTING] = 0,
	44	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	45	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	46	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	47	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
	48	},
	49	},
	50	.entries = {
	51	IP6T_STANDARD_INIT(NF_ACCEPT), /* PRE_ROUTING */
	52	IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
	53	IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
	54	IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
	55	IP6T_STANDARD_INIT(NF_ACCEPT), /* POST_ROUTING */
	56	},
	57	.term = IP6T_ERROR_INIT, /* ERROR */
1da177e4 LT	58	};
1da177e4 LT	59
e60a13e0	60	static struct xt_table packet_mangler = {
1da177e4 LT	61	.name = "mangle",
	62	.valid_hooks = MANGLE_VALID_HOOKS,
	63	.lock = RW_LOCK_UNLOCKED,
	64	.me = THIS_MODULE,
2e4e6a17	65	.af = AF_INET6,
1da177e4 LT	66	};
	67
	68	/* The work comes in here from netfilter.c. */
	69	static unsigned int
	70	ip6t_route_hook(unsigned int hook,
	71	struct sk_buff **pskb,
	72	const struct net_device *in,
	73	const struct net_device *out,
	74	int (okfn)(struct sk_buff ))
	75	{
fe1cb108	76	return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4 LT	77	}
	78
	79	static unsigned int
	80	ip6t_local_hook(unsigned int hook,
	81	struct sk_buff **pskb,
	82	const struct net_device *in,
	83	const struct net_device *out,
	84	int (okfn)(struct sk_buff ))
	85	{
	86
1da177e4 LT	87	unsigned int ret;
	88	struct in6_addr saddr, daddr;
	89	u_int8_t hop_limit;
82e91ffe	90	u_int32_t flowlabel, mark;
1da177e4 LT	91
	92	#if 0
	93	/* root is playing with raw sockets. */
	94	if ((*pskb)->len < sizeof(struct iphdr)
c9bdd4b5	95	\|\| ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
1da177e4 LT	96	if (net_ratelimit())
	97	printk("ip6t_hook: happy cracking.\n");
	98	return NF_ACCEPT;
	99	}
	100	#endif
	101
82e91ffe	102	/* save source/dest address, mark, hoplimit, flowlabel, priority, */
0660e03f ACM	103	memcpy(&saddr, &ipv6_hdr(*pskb)->saddr, sizeof(saddr));
0660e03f ACM	104	memcpy(&daddr, &ipv6_hdr(*pskb)->daddr, sizeof(daddr));
82e91ffe	105	mark = (*pskb)->mark;
0660e03f	106	hop_limit = ipv6_hdr(*pskb)->hop_limit;
1da177e4 LT	107
1da177e4 LT	108	/* flowlabel and prio (includes version, which shouldn't change either */
0660e03f	109	flowlabel = ((u_int32_t )ipv6_hdr(*pskb));
1da177e4	110
fe1cb108	111	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4	112
1ab1457c	113	if (ret != NF_DROP && ret != NF_STOLEN
0660e03f ACM	114	&& (memcmp(&ipv6_hdr(*pskb)->saddr, &saddr, sizeof(saddr))
0660e03f ACM	115	\|\| memcmp(&ipv6_hdr(*pskb)->daddr, &daddr, sizeof(daddr))
82e91ffe	116	\|\| (*pskb)->mark != mark
0660e03f	117	\|\| ipv6_hdr(*pskb)->hop_limit != hop_limit))
9123de2c	118	return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;
1da177e4 LT	119
	120	return ret;
	121	}
	122
	123	static struct nf_hook_ops ip6t_ops[] = {
	124	{
	125	.hook = ip6t_route_hook,
	126	.owner = THIS_MODULE,
	127	.pf = PF_INET6,
	128	.hooknum = NF_IP6_PRE_ROUTING,
	129	.priority = NF_IP6_PRI_MANGLE,
	130	},
	131	{
	132	.hook = ip6t_local_hook,
	133	.owner = THIS_MODULE,
	134	.pf = PF_INET6,
	135	.hooknum = NF_IP6_LOCAL_IN,
	136	.priority = NF_IP6_PRI_MANGLE,
	137	},
	138	{
	139	.hook = ip6t_route_hook,
	140	.owner = THIS_MODULE,
	141	.pf = PF_INET6,
	142	.hooknum = NF_IP6_FORWARD,
	143	.priority = NF_IP6_PRI_MANGLE,
	144	},
	145	{
	146	.hook = ip6t_local_hook,
	147	.owner = THIS_MODULE,
	148	.pf = PF_INET6,
	149	.hooknum = NF_IP6_LOCAL_OUT,
	150	.priority = NF_IP6_PRI_MANGLE,
	151	},
	152	{
	153	.hook = ip6t_route_hook,
	154	.owner = THIS_MODULE,
	155	.pf = PF_INET6,
	156	.hooknum = NF_IP6_POST_ROUTING,
	157	.priority = NF_IP6_PRI_MANGLE,
	158	},
	159	};
	160
65b4b4e8	161	static int __init ip6table_mangle_init(void)
1da177e4 LT	162	{
	163	int ret;
	164
	165	/* Register table */
	166	ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
	167	if (ret < 0)
	168	return ret;
	169
	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 LT	177	cleanup_table:
1da177e4 LT	178	ip6t_unregister_table(&packet_mangler);
1da177e4 LT	179	return ret;
	180	}
	181
65b4b4e8	182	static void __exit ip6table_mangle_fini(void)
1da177e4	183	{
964ddaa1	184	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	185	ip6t_unregister_table(&packet_mangler);
	186	}
	187
65b4b4e8 AM	188	module_init(ip6table_mangle_init);
65b4b4e8 AM	189	module_exit(ip6table_mangle_fini);