[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.
 *
 * Extended to all five netfilter hooks by Brad Chapman & Harald Welte
 */
#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.
	10	*
	11	* Extended to all five netfilter hooks by Brad Chapman & Harald Welte
	12	*/
	13	#include <linux/module.h>
	14	#include <linux/netfilter_ipv6/ip6_tables.h>
	15
	16	MODULE_LICENSE("GPL");
	17	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
	18	MODULE_DESCRIPTION("ip6tables mangle table");
	19
	20	#define MANGLE_VALID_HOOKS ((1 << NF_IP6_PRE_ROUTING) \| \
	21	(1 << NF_IP6_LOCAL_IN) \| \
	22	(1 << NF_IP6_FORWARD) \| \
	23	(1 << NF_IP6_LOCAL_OUT) \| \
	24	(1 << NF_IP6_POST_ROUTING))
	25
	26	#if 0
	27	#define DEBUGP(x, args...) printk(KERN_DEBUG x, ## args)
	28	#else
	29	#define DEBUGP(x, args...)
	30	#endif
	31
1da177e4 LT	32	static struct
	33	{
	34	struct ip6t_replace repl;
	35	struct ip6t_standard entries[5];
	36	struct ip6t_error term;
	37	} initial_table __initdata
	38	= { { "mangle", MANGLE_VALID_HOOKS, 6,
	39	sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
	40	{ [NF_IP6_PRE_ROUTING] = 0,
	41	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	42	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	43	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	44	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
	45	{ [NF_IP6_PRE_ROUTING] = 0,
	46	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	47	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	48	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	49	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
	50	0, NULL, { } },
	51	{
	52	/* PRE_ROUTING */
1ab1457c	53	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	54	0,
	55	sizeof(struct ip6t_entry),
	56	sizeof(struct ip6t_standard),
	57	0, { 0, 0 }, { } },
	58	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	59	-NF_ACCEPT - 1 } },
	60	/* LOCAL_IN */
1ab1457c	61	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	62	0,
	63	sizeof(struct ip6t_entry),
	64	sizeof(struct ip6t_standard),
	65	0, { 0, 0 }, { } },
	66	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	67	-NF_ACCEPT - 1 } },
	68	/* FORWARD */
1ab1457c	69	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	70	0,
	71	sizeof(struct ip6t_entry),
	72	sizeof(struct ip6t_standard),
	73	0, { 0, 0 }, { } },
	74	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	75	-NF_ACCEPT - 1 } },
	76	/* LOCAL_OUT */
1ab1457c	77	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
1da177e4 LT	78	0,
	79	sizeof(struct ip6t_entry),
	80	sizeof(struct ip6t_standard),
	81	0, { 0, 0 }, { } },
	82	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	83	-NF_ACCEPT - 1 } },
	84	/* POST_ROUTING */
	85	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	86	0,
	87	sizeof(struct ip6t_entry),
	88	sizeof(struct ip6t_standard),
	89	0, { 0, 0 }, { } },
	90	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
	91	-NF_ACCEPT - 1 } }
	92	},
	93	/* ERROR */
	94	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	95	0,
	96	sizeof(struct ip6t_entry),
	97	sizeof(struct ip6t_error),
	98	0, { 0, 0 }, { } },
	99	{ { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
	100	{ } },
	101	"ERROR"
	102	}
	103	}
	104	};
	105
e60a13e0	106	static struct xt_table packet_mangler = {
1da177e4 LT	107	.name = "mangle",
	108	.valid_hooks = MANGLE_VALID_HOOKS,
	109	.lock = RW_LOCK_UNLOCKED,
	110	.me = THIS_MODULE,
2e4e6a17	111	.af = AF_INET6,
1da177e4 LT	112	};
	113
	114	/* The work comes in here from netfilter.c. */
	115	static unsigned int
	116	ip6t_route_hook(unsigned int hook,
	117	struct sk_buff **pskb,
	118	const struct net_device *in,
	119	const struct net_device *out,
	120	int (okfn)(struct sk_buff ))
	121	{
fe1cb108	122	return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4 LT	123	}
	124
	125	static unsigned int
	126	ip6t_local_hook(unsigned int hook,
	127	struct sk_buff **pskb,
	128	const struct net_device *in,
	129	const struct net_device *out,
	130	int (okfn)(struct sk_buff ))
	131	{
	132
1da177e4 LT	133	unsigned int ret;
	134	struct in6_addr saddr, daddr;
	135	u_int8_t hop_limit;
82e91ffe	136	u_int32_t flowlabel, mark;
1da177e4 LT	137
	138	#if 0
	139	/* root is playing with raw sockets. */
	140	if ((*pskb)->len < sizeof(struct iphdr)
c9bdd4b5	141	\|\| ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
1da177e4 LT	142	if (net_ratelimit())
	143	printk("ip6t_hook: happy cracking.\n");
	144	return NF_ACCEPT;
	145	}
	146	#endif
	147
82e91ffe	148	/* save source/dest address, mark, hoplimit, flowlabel, priority, */
0660e03f ACM	149	memcpy(&saddr, &ipv6_hdr(*pskb)->saddr, sizeof(saddr));
0660e03f ACM	150	memcpy(&daddr, &ipv6_hdr(*pskb)->daddr, sizeof(daddr));
82e91ffe	151	mark = (*pskb)->mark;
0660e03f	152	hop_limit = ipv6_hdr(*pskb)->hop_limit;
1da177e4 LT	153
1da177e4 LT	154	/* flowlabel and prio (includes version, which shouldn't change either */
0660e03f	155	flowlabel = ((u_int32_t )ipv6_hdr(*pskb));
1da177e4	156
fe1cb108	157	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);
1da177e4	158
1ab1457c	159	if (ret != NF_DROP && ret != NF_STOLEN
0660e03f ACM	160	&& (memcmp(&ipv6_hdr(*pskb)->saddr, &saddr, sizeof(saddr))
0660e03f ACM	161	\|\| memcmp(&ipv6_hdr(*pskb)->daddr, &daddr, sizeof(daddr))
82e91ffe	162	\|\| (*pskb)->mark != mark
0660e03f	163	\|\| ipv6_hdr(*pskb)->hop_limit != hop_limit))
9123de2c	164	return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;
1da177e4 LT	165
	166	return ret;
	167	}
	168
	169	static struct nf_hook_ops ip6t_ops[] = {
	170	{
	171	.hook = ip6t_route_hook,
	172	.owner = THIS_MODULE,
	173	.pf = PF_INET6,
	174	.hooknum = NF_IP6_PRE_ROUTING,
	175	.priority = NF_IP6_PRI_MANGLE,
	176	},
	177	{
	178	.hook = ip6t_local_hook,
	179	.owner = THIS_MODULE,
	180	.pf = PF_INET6,
	181	.hooknum = NF_IP6_LOCAL_IN,
	182	.priority = NF_IP6_PRI_MANGLE,
	183	},
	184	{
	185	.hook = ip6t_route_hook,
	186	.owner = THIS_MODULE,
	187	.pf = PF_INET6,
	188	.hooknum = NF_IP6_FORWARD,
	189	.priority = NF_IP6_PRI_MANGLE,
	190	},
	191	{
	192	.hook = ip6t_local_hook,
	193	.owner = THIS_MODULE,
	194	.pf = PF_INET6,
	195	.hooknum = NF_IP6_LOCAL_OUT,
	196	.priority = NF_IP6_PRI_MANGLE,
	197	},
	198	{
	199	.hook = ip6t_route_hook,
	200	.owner = THIS_MODULE,
	201	.pf = PF_INET6,
	202	.hooknum = NF_IP6_POST_ROUTING,
	203	.priority = NF_IP6_PRI_MANGLE,
	204	},
	205	};
	206
65b4b4e8	207	static int __init ip6table_mangle_init(void)
1da177e4 LT	208	{
	209	int ret;
	210
	211	/* Register table */
	212	ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
	213	if (ret < 0)
	214	return ret;
	215
	216	/* Register hooks */
964ddaa1	217	ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	218	if (ret < 0)
	219	goto cleanup_table;
	220
1da177e4 LT	221	return ret;
1da177e4 LT	222
1da177e4 LT	223	cleanup_table:
1da177e4 LT	224	ip6t_unregister_table(&packet_mangler);
1da177e4 LT	225	return ret;
	226	}
	227
65b4b4e8	228	static void __exit ip6table_mangle_fini(void)
1da177e4	229	{
964ddaa1	230	nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
1da177e4 LT	231	ip6t_unregister_table(&packet_mangler);
	232	}
	233
65b4b4e8 AM	234	module_init(ip6table_mangle_init);
65b4b4e8 AM	235	module_exit(ip6table_mangle_fini);