[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))

#if 0
#define DEBUGP(x, args...)	printk(KERN_DEBUG x, ## args)
#else
#define DEBUGP(x, args...)
#endif

static struct
{
	struct ip6t_replace repl;
	struct ip6t_standard entries[5];
	struct ip6t_error term;
} initial_table __initdata
= { { "mangle", MANGLE_VALID_HOOKS, 6,
      sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
      { [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},
      { [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},
      0, NULL, { } },
    {
	    /* PRE_ROUTING */
	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ip6t_entry),
		sizeof(struct ip6t_standard),
		0, { 0, 0 }, { } },
	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* LOCAL_IN */
	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ip6t_entry),
		sizeof(struct ip6t_standard),
		0, { 0, 0 }, { } },
	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* FORWARD */
	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ip6t_entry),
		sizeof(struct ip6t_standard),
		0, { 0, 0 }, { } },
	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* LOCAL_OUT */
	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ip6t_entry),
		sizeof(struct ip6t_standard),
		0, { 0, 0 }, { } },
	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* POST_ROUTING */
	    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ip6t_entry),
		sizeof(struct ip6t_standard),
		0, { 0, 0 }, { } },
	      { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } }
    },
    /* ERROR */
    { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	0,
	sizeof(struct ip6t_entry),
	sizeof(struct ip6t_error),
	0, { 0, 0 }, { } },
      { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
	  { } },
	"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
	24	#if 0
	25	#define DEBUGP(x, args...) printk(KERN_DEBUG x, ## args)
	26	#else
	27	#define DEBUGP(x, args...)
	28	#endif
	29
1da177e4 LT	30	static struct
	31	{
	32	struct ip6t_replace repl;
	33	struct ip6t_standard entries[5];
	34	struct ip6t_error term;
	35	} initial_table __initdata
	36	= { { "mangle", MANGLE_VALID_HOOKS, 6,
	37	sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
	38	{ [NF_IP6_PRE_ROUTING] = 0,
	39	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	40	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	41	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	42	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
	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	0, NULL, { } },
	49	{
	50	/* PRE_ROUTING */
1ab1457c	51	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	52	0,
	53	sizeof(struct ip6t_entry),
	54	sizeof(struct ip6t_standard),
	55	0, { 0, 0 }, { } },
	56	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	57	-NF_ACCEPT - 1 } },
	58	/* LOCAL_IN */
1ab1457c	59	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	60	0,
	61	sizeof(struct ip6t_entry),
	62	sizeof(struct ip6t_standard),
	63	0, { 0, 0 }, { } },
	64	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	65	-NF_ACCEPT - 1 } },
	66	/* FORWARD */
1ab1457c	67	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	68	0,
	69	sizeof(struct ip6t_entry),
	70	sizeof(struct ip6t_standard),
	71	0, { 0, 0 }, { } },
	72	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	73	-NF_ACCEPT - 1 } },
	74	/* LOCAL_OUT */
1ab1457c	75	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	76	0,
	77	sizeof(struct ip6t_entry),
	78	sizeof(struct ip6t_standard),
	79	0, { 0, 0 }, { } },
	80	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	81	-NF_ACCEPT - 1 } },
	82	/* POST_ROUTING */
	83	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	84	0,
	85	sizeof(struct ip6t_entry),
	86	sizeof(struct ip6t_standard),
	87	0, { 0, 0 }, { } },
	88	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	89	-NF_ACCEPT - 1 } }
	90	},
	91	/* ERROR */
	92	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	93	0,
	94	sizeof(struct ip6t_entry),
	95	sizeof(struct ip6t_error),
	96	0, { 0, 0 }, { } },
	97	{ { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
	98	{ } },
	99	"ERROR"
	100	}
	101	}
	102	};
	103
e60a13e0	104	static struct xt_table packet_mangler = {
1da177e4 LT	105	.name = "mangle",
	106	.valid_hooks = MANGLE_VALID_HOOKS,
	107	.lock = RW_LOCK_UNLOCKED,
	108	.me = THIS_MODULE,
2e4e6a17	109	.af = AF_INET6,
1da177e4 LT	110	};
	111
	112	/* The work comes in here from netfilter.c. */
	113	static unsigned int
	114	ip6t_route_hook(unsigned int hook,
	115	struct sk_buff **pskb,
	116	const struct net_device *in,
	117	const struct net_device *out,
	118	int (okfn)(struct sk_buff ))
	119	{
fe1cb108	120	return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4 LT	121	}
	122
	123	static unsigned int
	124	ip6t_local_hook(unsigned int hook,
	125	struct sk_buff **pskb,
	126	const struct net_device *in,
	127	const struct net_device *out,
	128	int (okfn)(struct sk_buff ))
	129	{
	130
1da177e4 LT	131	unsigned int ret;
	132	struct in6_addr saddr, daddr;
	133	u_int8_t hop_limit;
82e91ffe	134	u_int32_t flowlabel, mark;
1da177e4 LT	135
	136	#if 0
	137	/* root is playing with raw sockets. */
	138	if ((*pskb)->len < sizeof(struct iphdr)
c9bdd4b5	139	\|\| ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
1da177e4 LT	140	if (net_ratelimit())
	141	printk("ip6t_hook: happy cracking.\n");
	142	return NF_ACCEPT;
	143	}
	144	#endif
	145
82e91ffe	146	/* save source/dest address, mark, hoplimit, flowlabel, priority, */
0660e03f ACM	147	memcpy(&saddr, &ipv6_hdr(*pskb)->saddr, sizeof(saddr));
0660e03f ACM	148	memcpy(&daddr, &ipv6_hdr(*pskb)->daddr, sizeof(daddr));
82e91ffe	149	mark = (*pskb)->mark;
0660e03f	150	hop_limit = ipv6_hdr(*pskb)->hop_limit;
1da177e4 LT	151
1da177e4 LT	152	/* flowlabel and prio (includes version, which shouldn't change either */
0660e03f	153	flowlabel = ((u_int32_t )ipv6_hdr(*pskb));
1da177e4	154
fe1cb108	155	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4	156
1ab1457c	157	if (ret != NF_DROP && ret != NF_STOLEN
0660e03f ACM	158	&& (memcmp(&ipv6_hdr(*pskb)->saddr, &saddr, sizeof(saddr))
0660e03f ACM	159	\|\| memcmp(&ipv6_hdr(*pskb)->daddr, &daddr, sizeof(daddr))
82e91ffe	160	\|\| (*pskb)->mark != mark
0660e03f	161	\|\| ipv6_hdr(*pskb)->hop_limit != hop_limit))
9123de2c	162	return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;
1da177e4 LT	163
	164	return ret;
	165	}
	166
	167	static struct nf_hook_ops ip6t_ops[] = {
	168	{
	169	.hook = ip6t_route_hook,
	170	.owner = THIS_MODULE,
	171	.pf = PF_INET6,
	172	.hooknum = NF_IP6_PRE_ROUTING,
	173	.priority = NF_IP6_PRI_MANGLE,
	174	},
	175	{
	176	.hook = ip6t_local_hook,
	177	.owner = THIS_MODULE,
	178	.pf = PF_INET6,
	179	.hooknum = NF_IP6_LOCAL_IN,
	180	.priority = NF_IP6_PRI_MANGLE,
	181	},
	182	{
	183	.hook = ip6t_route_hook,
	184	.owner = THIS_MODULE,
	185	.pf = PF_INET6,
	186	.hooknum = NF_IP6_FORWARD,
	187	.priority = NF_IP6_PRI_MANGLE,
	188	},
	189	{
	190	.hook = ip6t_local_hook,
	191	.owner = THIS_MODULE,
	192	.pf = PF_INET6,
	193	.hooknum = NF_IP6_LOCAL_OUT,
	194	.priority = NF_IP6_PRI_MANGLE,
	195	},
	196	{
	197	.hook = ip6t_route_hook,
	198	.owner = THIS_MODULE,
	199	.pf = PF_INET6,
	200	.hooknum = NF_IP6_POST_ROUTING,
	201	.priority = NF_IP6_PRI_MANGLE,
	202	},
	203	};
	204
65b4b4e8	205	static int __init ip6table_mangle_init(void)
1da177e4 LT	206	{
	207	int ret;
	208
	209	/* Register table */
	210	ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
	211	if (ret < 0)
	212	return ret;
	213
	214	/* Register hooks */
964ddaa1	215	ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	216	if (ret < 0)
	217	goto cleanup_table;
	218
1da177e4 LT	219	return ret;
1da177e4 LT	220
1da177e4 LT	221	cleanup_table:
1da177e4 LT	222	ip6t_unregister_table(&packet_mangler);
1da177e4 LT	223	return ret;
	224	}
	225
65b4b4e8	226	static void __exit ip6table_mangle_fini(void)
1da177e4	227	{
964ddaa1	228	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	229	ip6t_unregister_table(&packet_mangler);
	230	}
	231
65b4b4e8 AM	232	module_init(ip6table_mangle_init);
65b4b4e8 AM	233	module_exit(ip6table_mangle_fini);