[linux-2.6-block.git] / net / netfilter / xt_CONNMARK.c

/*
 *	xt_CONNMARK - Netfilter module to modify the connection mark values
 *
 *	Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
 *	by Henrik Nordstrom <hno@marasystems.com>
 *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *	Jan Engelhardt <jengelh@computergmbh.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/checksum.h>

MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
MODULE_DESCRIPTION("Xtables: connection mark modification");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_CONNMARK");
MODULE_ALIAS("ip6t_CONNMARK");

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_CONNMARK.h>
#include <net/netfilter/nf_conntrack_ecache.h>

static unsigned int
connmark_tg_v0(struct sk_buff *skb, const struct xt_target_param *par)
{
	const struct xt_connmark_target_info *markinfo = par->targinfo;
	struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	u_int32_t diff;
	u_int32_t mark;
	u_int32_t newmark;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) {
		switch(markinfo->mode) {
		case XT_CONNMARK_SET:
			newmark = (ct->mark & ~markinfo->mask) | markinfo->mark;
			if (newmark != ct->mark) {
				ct->mark = newmark;
				nf_conntrack_event_cache(IPCT_MARK, ct);
			}
			break;
		case XT_CONNMARK_SAVE:
			newmark = (ct->mark & ~markinfo->mask) |
				  (skb->mark & markinfo->mask);
			if (ct->mark != newmark) {
				ct->mark = newmark;
				nf_conntrack_event_cache(IPCT_MARK, ct);
			}
			break;
		case XT_CONNMARK_RESTORE:
			mark = skb->mark;
			diff = (ct->mark ^ mark) & markinfo->mask;
			skb->mark = mark ^ diff;
			break;
		}
	}

	return XT_CONTINUE;
}

static unsigned int
connmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
	const struct xt_connmark_tginfo1 *info = par->targinfo;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	u_int32_t newmark;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct == NULL)
		return XT_CONTINUE;

	switch (info->mode) {
	case XT_CONNMARK_SET:
		newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
		if (ct->mark != newmark) {
			ct->mark = newmark;
			nf_conntrack_event_cache(IPCT_MARK, ct);
		}
		break;
	case XT_CONNMARK_SAVE:
		newmark = (ct->mark & ~info->ctmask) ^
		          (skb->mark & info->nfmask);
		if (ct->mark != newmark) {
			ct->mark = newmark;
			nf_conntrack_event_cache(IPCT_MARK, ct);
		}
		break;
	case XT_CONNMARK_RESTORE:
		newmark = (skb->mark & ~info->nfmask) ^
		          (ct->mark & info->ctmask);
		skb->mark = newmark;
		break;
	}

	return XT_CONTINUE;
}

static bool connmark_tg_check_v0(const struct xt_tgchk_param *par)
{
	const struct xt_connmark_target_info *matchinfo = par->targinfo;

	if (matchinfo->mode == XT_CONNMARK_RESTORE) {
		if (strcmp(par->table, "mangle") != 0) {
			printk(KERN_WARNING "CONNMARK: restore can only be "
			       "called from \"mangle\" table, not \"%s\"\n",
			       par->table);
			return false;
		}
	}
	if (matchinfo->mark > 0xffffffff || matchinfo->mask > 0xffffffff) {
		printk(KERN_WARNING "CONNMARK: Only supports 32bit mark\n");
		return false;
	}
	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
		printk(KERN_WARNING "can't load conntrack support for "
				    "proto=%u\n", par->family);
		return false;
	}
	return true;
}

static bool connmark_tg_check(const struct xt_tgchk_param *par)
{
	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
		printk(KERN_WARNING "cannot load conntrack support for "
		       "proto=%u\n", par->family);
		return false;
	}
	return true;
}

static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
{
	nf_ct_l3proto_module_put(par->family);
}

#ifdef CONFIG_COMPAT
struct compat_xt_connmark_target_info {
	compat_ulong_t	mark, mask;
	u_int8_t	mode;
	u_int8_t	__pad1;
	u_int16_t	__pad2;
};

static void connmark_tg_compat_from_user_v0(void *dst, void *src)
{
	const struct compat_xt_connmark_target_info *cm = src;
	struct xt_connmark_target_info m = {
		.mark	= cm->mark,
		.mask	= cm->mask,
		.mode	= cm->mode,
	};
	memcpy(dst, &m, sizeof(m));
}

static int connmark_tg_compat_to_user_v0(void __user *dst, void *src)
{
	const struct xt_connmark_target_info *m = src;
	struct compat_xt_connmark_target_info cm = {
		.mark	= m->mark,
		.mask	= m->mask,
		.mode	= m->mode,
	};
	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
}
#endif /* CONFIG_COMPAT */

static struct xt_target connmark_tg_reg[] __read_mostly = {
	{
		.name		= "CONNMARK",
		.revision	= 0,
		.family		= NFPROTO_UNSPEC,
		.checkentry	= connmark_tg_check_v0,
		.destroy	= connmark_tg_destroy,
		.target		= connmark_tg_v0,
		.targetsize	= sizeof(struct xt_connmark_target_info),
#ifdef CONFIG_COMPAT
		.compatsize	= sizeof(struct compat_xt_connmark_target_info),
		.compat_from_user = connmark_tg_compat_from_user_v0,
		.compat_to_user	= connmark_tg_compat_to_user_v0,
#endif
		.me		= THIS_MODULE
	},
	{
		.name           = "CONNMARK",
		.revision       = 1,
		.family         = NFPROTO_UNSPEC,
		.checkentry     = connmark_tg_check,
		.target         = connmark_tg,
		.targetsize     = sizeof(struct xt_connmark_tginfo1),
		.destroy        = connmark_tg_destroy,
		.me             = THIS_MODULE,
	},
};

static int __init connmark_tg_init(void)
{
	return xt_register_targets(connmark_tg_reg,
	       ARRAY_SIZE(connmark_tg_reg));
}

static void __exit connmark_tg_exit(void)
{
	xt_unregister_targets(connmark_tg_reg, ARRAY_SIZE(connmark_tg_reg));
}

module_init(connmark_tg_init);
module_exit(connmark_tg_exit);
Commit	Line	Data
0dc8c760 JE	1	/*
0dc8c760 JE	2	* xt_CONNMARK - Netfilter module to modify the connection mark values
1da177e4	3	*
0dc8c760 JE	4	* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
	5	* by Henrik Nordstrom <hno@marasystems.com>
	6	* Copyright © CC Computer Consultants GmbH, 2007 - 2008
	7	* Jan Engelhardt <jengelh@computergmbh.de>
1da177e4 LT	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23	#include <linux/module.h>
	24	#include <linux/skbuff.h>
	25	#include <linux/ip.h>
	26	#include <net/checksum.h>
	27
3a4fa0a2	28	MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
2ae15b64	29	MODULE_DESCRIPTION("Xtables: connection mark modification");
1da177e4	30	MODULE_LICENSE("GPL");
2e4e6a17	31	MODULE_ALIAS("ipt_CONNMARK");
73aaf935	32	MODULE_ALIAS("ip6t_CONNMARK");
1da177e4	33
2e4e6a17 HW	34	#include <linux/netfilter/x_tables.h>
2e4e6a17 HW	35	#include <linux/netfilter/xt_CONNMARK.h>
f6180121	36	#include <net/netfilter/nf_conntrack_ecache.h>
1da177e4 LT	37
1da177e4 LT	38	static unsigned int
7eb35586	39	connmark_tg_v0(struct sk_buff skb, const struct xt_target_param par)
1da177e4	40	{
7eb35586	41	const struct xt_connmark_target_info *markinfo = par->targinfo;
587aa641 PM	42	struct nf_conn *ct;
587aa641 PM	43	enum ip_conntrack_info ctinfo;
bf3a46aa	44	u_int32_t diff;
82e91ffe	45	u_int32_t mark;
bf3a46aa	46	u_int32_t newmark;
1da177e4	47
3db05fea	48	ct = nf_ct_get(skb, &ctinfo);
587aa641	49	if (ct) {
90528e6f PM	50	switch(markinfo->mode) {
90528e6f PM	51	case XT_CONNMARK_SET:
587aa641 PM	52	newmark = (ct->mark & ~markinfo->mask) \| markinfo->mark;
	53	if (newmark != ct->mark) {
	54	ct->mark = newmark;
a71996fc	55	nf_conntrack_event_cache(IPCT_MARK, ct);
2822b0d9	56	}
90528e6f PM	57	break;
90528e6f PM	58	case XT_CONNMARK_SAVE:
587aa641	59	newmark = (ct->mark & ~markinfo->mask) \|
3db05fea	60	(skb->mark & markinfo->mask);
587aa641 PM	61	if (ct->mark != newmark) {
587aa641 PM	62	ct->mark = newmark;
a71996fc	63	nf_conntrack_event_cache(IPCT_MARK, ct);
90528e6f PM	64	}
	65	break;
	66	case XT_CONNMARK_RESTORE:
3db05fea	67	mark = skb->mark;
587aa641	68	diff = (ct->mark ^ mark) & markinfo->mask;
3db05fea	69	skb->mark = mark ^ diff;
90528e6f	70	break;
2521c12c	71	}
1da177e4 LT	72	}
1da177e4 LT	73
2e4e6a17	74	return XT_CONTINUE;
1da177e4 LT	75	}
1da177e4 LT	76
0dc8c760	77	static unsigned int
7eb35586	78	connmark_tg(struct sk_buff skb, const struct xt_target_param par)
0dc8c760	79	{
7eb35586	80	const struct xt_connmark_tginfo1 *info = par->targinfo;
0dc8c760 JE	81	enum ip_conntrack_info ctinfo;
	82	struct nf_conn *ct;
	83	u_int32_t newmark;
	84
	85	ct = nf_ct_get(skb, &ctinfo);
	86	if (ct == NULL)
	87	return XT_CONTINUE;
	88
	89	switch (info->mode) {
	90	case XT_CONNMARK_SET:
	91	newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
	92	if (ct->mark != newmark) {
	93	ct->mark = newmark;
a71996fc	94	nf_conntrack_event_cache(IPCT_MARK, ct);
0dc8c760 JE	95	}
	96	break;
	97	case XT_CONNMARK_SAVE:
	98	newmark = (ct->mark & ~info->ctmask) ^
	99	(skb->mark & info->nfmask);
	100	if (ct->mark != newmark) {
	101	ct->mark = newmark;
a71996fc	102	nf_conntrack_event_cache(IPCT_MARK, ct);
0dc8c760 JE	103	}
	104	break;
	105	case XT_CONNMARK_RESTORE:
	106	newmark = (skb->mark & ~info->nfmask) ^
	107	(ct->mark & info->ctmask);
	108	skb->mark = newmark;
	109	break;
	110	}
	111
	112	return XT_CONTINUE;
	113	}
	114
af5d6dc2	115	static bool connmark_tg_check_v0(const struct xt_tgchk_param *par)
1da177e4	116	{
af5d6dc2	117	const struct xt_connmark_target_info *matchinfo = par->targinfo;
1da177e4	118
2e4e6a17	119	if (matchinfo->mode == XT_CONNMARK_RESTORE) {
af5d6dc2	120	if (strcmp(par->table, "mangle") != 0) {
90528e6f PM	121	printk(KERN_WARNING "CONNMARK: restore can only be "
90528e6f PM	122	"called from \"mangle\" table, not \"%s\"\n",
af5d6dc2	123	par->table);
e1931b78	124	return false;
90528e6f	125	}
1da177e4	126	}
bf3a46aa HW	127	if (matchinfo->mark > 0xffffffff \|\| matchinfo->mask > 0xffffffff) {
bf3a46aa HW	128	printk(KERN_WARNING "CONNMARK: Only supports 32bit mark\n");
e1931b78	129	return false;
bf3a46aa	130	}
92f3b2b1	131	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
67b4af29	132	printk(KERN_WARNING "can't load conntrack support for "
92f3b2b1	133	"proto=%u\n", par->family);
67b4af29 JE	134	return false;
67b4af29 JE	135	}
e1931b78	136	return true;
1da177e4 LT	137	}
1da177e4 LT	138
af5d6dc2	139	static bool connmark_tg_check(const struct xt_tgchk_param *par)
0dc8c760	140	{
92f3b2b1	141	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
0dc8c760	142	printk(KERN_WARNING "cannot load conntrack support for "
92f3b2b1	143	"proto=%u\n", par->family);
0dc8c760 JE	144	return false;
	145	}
	146	return true;
	147	}
	148
a2df1648	149	static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
11078c37	150	{
92f3b2b1	151	nf_ct_l3proto_module_put(par->family);
11078c37 YK	152	}
11078c37 YK	153
7ce975b9 PM	154	#ifdef CONFIG_COMPAT
	155	struct compat_xt_connmark_target_info {
	156	compat_ulong_t mark, mask;
	157	u_int8_t mode;
	158	u_int8_t __pad1;
	159	u_int16_t __pad2;
	160	};
	161
0dc8c760	162	static void connmark_tg_compat_from_user_v0(void dst, void src)
7ce975b9	163	{
a47362a2	164	const struct compat_xt_connmark_target_info *cm = src;
7ce975b9 PM	165	struct xt_connmark_target_info m = {
	166	.mark = cm->mark,
	167	.mask = cm->mask,
	168	.mode = cm->mode,
	169	};
	170	memcpy(dst, &m, sizeof(m));
	171	}
	172
0dc8c760	173	static int connmark_tg_compat_to_user_v0(void __user dst, void src)
7ce975b9	174	{
a47362a2	175	const struct xt_connmark_target_info *m = src;
7ce975b9 PM	176	struct compat_xt_connmark_target_info cm = {
	177	.mark = m->mark,
	178	.mask = m->mask,
	179	.mode = m->mode,
	180	};
	181	return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
	182	}
	183	#endif /* CONFIG_COMPAT */
	184
d3c5ee6d	185	static struct xt_target connmark_tg_reg[] __read_mostly = {
4470bbc7 PM	186	{
4470bbc7 PM	187	.name = "CONNMARK",
0dc8c760	188	.revision = 0,
92f3b2b1	189	.family = NFPROTO_UNSPEC,
0dc8c760	190	.checkentry = connmark_tg_check_v0,
d3c5ee6d	191	.destroy = connmark_tg_destroy,
0dc8c760	192	.target = connmark_tg_v0,
4470bbc7	193	.targetsize = sizeof(struct xt_connmark_target_info),
7ce975b9 PM	194	#ifdef CONFIG_COMPAT
7ce975b9 PM	195	.compatsize = sizeof(struct compat_xt_connmark_target_info),
0dc8c760 JE	196	.compat_from_user = connmark_tg_compat_from_user_v0,
0dc8c760 JE	197	.compat_to_user = connmark_tg_compat_to_user_v0,
7ce975b9	198	#endif
4470bbc7 PM	199	.me = THIS_MODULE
4470bbc7 PM	200	},
0dc8c760 JE	201	{
	202	.name = "CONNMARK",
	203	.revision = 1,
92f3b2b1	204	.family = NFPROTO_UNSPEC,
0dc8c760 JE	205	.checkentry = connmark_tg_check,
	206	.target = connmark_tg,
	207	.targetsize = sizeof(struct xt_connmark_tginfo1),
	208	.destroy = connmark_tg_destroy,
	209	.me = THIS_MODULE,
	210	},
1da177e4 LT	211	};
1da177e4 LT	212
d3c5ee6d	213	static int __init connmark_tg_init(void)
1da177e4	214	{
d3c5ee6d JE	215	return xt_register_targets(connmark_tg_reg,
d3c5ee6d JE	216	ARRAY_SIZE(connmark_tg_reg));
1da177e4 LT	217	}
1da177e4 LT	218
d3c5ee6d	219	static void __exit connmark_tg_exit(void)
1da177e4	220	{
d3c5ee6d	221	xt_unregister_targets(connmark_tg_reg, ARRAY_SIZE(connmark_tg_reg));
1da177e4 LT	222	}
1da177e4 LT	223
d3c5ee6d JE	224	module_init(connmark_tg_init);
d3c5ee6d JE	225	module_exit(connmark_tg_exit);