[mirror_ubuntu-bionic-kernel.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

/* Standard entry. */
struct ip6t_standard
{
	struct ip6t_entry entry;
	struct ip6t_standard_target target;
};

struct ip6t_error_target
{
	struct ip6t_entry_target target;
	char errorname[IP6T_FUNCTION_MAXNAMELEN];
};

struct ip6t_error
{
	struct ip6t_entry entry;
	struct ip6t_error_target target;
};

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 ip6t_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, NULL);
}

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

#if 0
	/* root is playing with raw sockets. */
	if ((*pskb)->len < sizeof(struct iphdr)
	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
		if (net_ratelimit())
			printk("ip6t_hook: happy cracking.\n");
		return NF_ACCEPT;
	}
#endif

	/* save source/dest address, nfmark, hoplimit, flowlabel, priority,  */
	memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));
	memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));
	nfmark = (*pskb)->nfmark;
	hop_limit = (*pskb)->nh.ipv6h->hop_limit;

	/* flowlabel and prio (includes version, which shouldn't change either */
	flowlabel = *((u_int32_t *) (*pskb)->nh.ipv6h);

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

	if (ret != NF_DROP && ret != NF_STOLEN 
		&& (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))
		    || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))
		    || (*pskb)->nfmark != nfmark
		    || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) {

		/* something which could affect routing has changed */

		DEBUGP("ip6table_mangle: we'd need to re-route a packet\n");
	}

	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 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_hook(&ip6t_ops[0]);
	if (ret < 0)
		goto cleanup_table;

	ret = nf_register_hook(&ip6t_ops[1]);
	if (ret < 0)
		goto cleanup_hook0;

	ret = nf_register_hook(&ip6t_ops[2]);
	if (ret < 0)
		goto cleanup_hook1;

	ret = nf_register_hook(&ip6t_ops[3]);
	if (ret < 0)
		goto cleanup_hook2;

	ret = nf_register_hook(&ip6t_ops[4]);
	if (ret < 0)
		goto cleanup_hook3;

	return ret;

 cleanup_hook3:
        nf_unregister_hook(&ip6t_ops[3]);
 cleanup_hook2:
	nf_unregister_hook(&ip6t_ops[2]);
 cleanup_hook1:
	nf_unregister_hook(&ip6t_ops[1]);
 cleanup_hook0:
	nf_unregister_hook(&ip6t_ops[0]);
 cleanup_table:
	ip6t_unregister_table(&packet_mangler);

	return ret;
}

static void __exit fini(void)
{
	unsigned int i;

	for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++)
		nf_unregister_hook(&ip6t_ops[i]);

	ip6t_unregister_table(&packet_mangler);
}

module_init(init);
module_exit(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
	32	/* Standard entry. */
	33	struct ip6t_standard
	34	{
	35	struct ip6t_entry entry;
	36	struct ip6t_standard_target target;
	37	};
	38
	39	struct ip6t_error_target
	40	{
	41	struct ip6t_entry_target target;
	42	char errorname[IP6T_FUNCTION_MAXNAMELEN];
	43	};
	44
	45	struct ip6t_error
	46	{
	47	struct ip6t_entry entry;
	48	struct ip6t_error_target target;
	49	};
	50
	51	static struct
	52	{
	53	struct ip6t_replace repl;
	54	struct ip6t_standard entries[5];
	55	struct ip6t_error term;
	56	} initial_table __initdata
	57	= { { "mangle", MANGLE_VALID_HOOKS, 6,
	58	sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
	59	{ [NF_IP6_PRE_ROUTING] = 0,
	60	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
	61	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
	62	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
	63	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
	64	{ [NF_IP6_PRE_ROUTING] = 0,
65	[NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
66	[NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
67	[NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
68	[NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
69	0, NULL, { } },
70	{
71	/* PRE_ROUTING */
72	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
73	0,
74	sizeof(struct ip6t_entry),
75	sizeof(struct ip6t_standard),
76	0, { 0, 0 }, { } },
77	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
78	-NF_ACCEPT - 1 } },
79	/* LOCAL_IN */
80	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
81	0,
82	sizeof(struct ip6t_entry),
83	sizeof(struct ip6t_standard),
84	0, { 0, 0 }, { } },
85	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
86	-NF_ACCEPT - 1 } },
87	/* FORWARD */
88	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
89	0,
90	sizeof(struct ip6t_entry),
91	sizeof(struct ip6t_standard),
92	0, { 0, 0 }, { } },
93	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
94	-NF_ACCEPT - 1 } },
95	/* LOCAL_OUT */
96	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
97	0,
98	sizeof(struct ip6t_entry),
99	sizeof(struct ip6t_standard),
100	0, { 0, 0 }, { } },
101	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
102	-NF_ACCEPT - 1 } },
103	/* POST_ROUTING */
104	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
105	0,
106	sizeof(struct ip6t_entry),
107	sizeof(struct ip6t_standard),
108	0, { 0, 0 }, { } },
109	{ { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
110	-NF_ACCEPT - 1 } }
111	},
112	/* ERROR */
113	{ { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
114	0,
115	sizeof(struct ip6t_entry),
116	sizeof(struct ip6t_error),
117	0, { 0, 0 }, { } },
118	{ { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
119	{ } },
120	"ERROR"
121	}
122	}
123	};
124
125	static struct ip6t_table packet_mangler = {
126	.name = "mangle",
127	.valid_hooks = MANGLE_VALID_HOOKS,
128	.lock = RW_LOCK_UNLOCKED,
129	.me = THIS_MODULE,
2e4e6a17	130	.af = AF_INET6,
1da177e4 LT	131	};
	132
	133	/* The work comes in here from netfilter.c. */
	134	static unsigned int
	135	ip6t_route_hook(unsigned int hook,
	136	struct sk_buff **pskb,
	137	const struct net_device *in,
	138	const struct net_device *out,
	139	int (okfn)(struct sk_buff ))
	140	{
	141	return ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
	142	}
	143
	144	static unsigned int
	145	ip6t_local_hook(unsigned int hook,
	146	struct sk_buff **pskb,
	147	const struct net_device *in,
	148	const struct net_device *out,
	149	int (okfn)(struct sk_buff ))
	150	{
	151
	152	unsigned long nfmark;
	153	unsigned int ret;
	154	struct in6_addr saddr, daddr;
	155	u_int8_t hop_limit;
	156	u_int32_t flowlabel;
	157
	158	#if 0
	159	/* root is playing with raw sockets. */
	160	if ((*pskb)->len < sizeof(struct iphdr)
	161	\|\| (pskb)->nh.iph->ihl 4 < sizeof(struct iphdr)) {
	162	if (net_ratelimit())
	163	printk("ip6t_hook: happy cracking.\n");
	164	return NF_ACCEPT;
	165	}
	166	#endif
	167
	168	/* save source/dest address, nfmark, hoplimit, flowlabel, priority, */
	169	memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));
	170	memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));
	171	nfmark = (*pskb)->nfmark;
	172	hop_limit = (*pskb)->nh.ipv6h->hop_limit;
	173
	174	/* flowlabel and prio (includes version, which shouldn't change either */
	175	flowlabel = ((u_int32_t ) (*pskb)->nh.ipv6h);
	176
	177	ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
	178
	179	if (ret != NF_DROP && ret != NF_STOLEN
	180	&& (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))
	181	\|\| memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))
	182	\|\| (*pskb)->nfmark != nfmark
	183	\|\| (*pskb)->nh.ipv6h->hop_limit != hop_limit)) {
	184
	185	/* something which could affect routing has changed */
	186
	187	DEBUGP("ip6table_mangle: we'd need to re-route a packet\n");
	188	}
	189
	190	return ret;
	191	}
	192
	193	static struct nf_hook_ops ip6t_ops[] = {
	194	{
195	.hook = ip6t_route_hook,
196	.owner = THIS_MODULE,
197	.pf = PF_INET6,
198	.hooknum = NF_IP6_PRE_ROUTING,
199	.priority = NF_IP6_PRI_MANGLE,
200	},
201	{
202	.hook = ip6t_local_hook,
203	.owner = THIS_MODULE,
204	.pf = PF_INET6,
205	.hooknum = NF_IP6_LOCAL_IN,
206	.priority = NF_IP6_PRI_MANGLE,
207	},
208	{
209	.hook = ip6t_route_hook,
210	.owner = THIS_MODULE,
211	.pf = PF_INET6,
212	.hooknum = NF_IP6_FORWARD,
213	.priority = NF_IP6_PRI_MANGLE,
214	},
215	{
216	.hook = ip6t_local_hook,
217	.owner = THIS_MODULE,
218	.pf = PF_INET6,
219	.hooknum = NF_IP6_LOCAL_OUT,
220	.priority = NF_IP6_PRI_MANGLE,
221	},
222	{
223	.hook = ip6t_route_hook,
224	.owner = THIS_MODULE,
225	.pf = PF_INET6,
226	.hooknum = NF_IP6_POST_ROUTING,
227	.priority = NF_IP6_PRI_MANGLE,
228	},
229	};
230
231	static int __init init(void)
232	{
233	int ret;
234
235	/* Register table */
236	ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
237	if (ret < 0)
238	return ret;
239
240	/* Register hooks */
241	ret = nf_register_hook(&ip6t_ops[0]);
242	if (ret < 0)
243	goto cleanup_table;
244
245	ret = nf_register_hook(&ip6t_ops[1]);
246	if (ret < 0)
247	goto cleanup_hook0;
248
249	ret = nf_register_hook(&ip6t_ops[2]);
250	if (ret < 0)
251	goto cleanup_hook1;
252
253	ret = nf_register_hook(&ip6t_ops[3]);
254	if (ret < 0)
255	goto cleanup_hook2;
256
257	ret = nf_register_hook(&ip6t_ops[4]);
258	if (ret < 0)
259	goto cleanup_hook3;
260
261	return ret;
262
263	cleanup_hook3:
264	nf_unregister_hook(&ip6t_ops[3]);
265	cleanup_hook2:
266	nf_unregister_hook(&ip6t_ops[2]);
267	cleanup_hook1:
268	nf_unregister_hook(&ip6t_ops[1]);
269	cleanup_hook0:
270	nf_unregister_hook(&ip6t_ops[0]);
271	cleanup_table:
272	ip6t_unregister_table(&packet_mangler);
273
274	return ret;
275	}
276
277	static void __exit fini(void)
278	{
279	unsigned int i;
280
281	for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++)
282	nf_unregister_hook(&ip6t_ops[i]);
283
284	ip6t_unregister_table(&packet_mangler);
285	}
286
287	module_init(init);
288	module_exit(fini);