[net-next-2.6.git] / net / netfilter / xt_SECMARK.c

/*
 * Module for modifying the secmark field of the skb, for use by
 * security subsystems.
 *
 * Based on the nfmark match by:
 * (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
 *
 * (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *
 * 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/skbuff.h>
#include <linux/selinux.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_SECMARK.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
MODULE_DESCRIPTION("ip[6]tables SECMARK modification module");
MODULE_ALIAS("ipt_SECMARK");
MODULE_ALIAS("ip6t_SECMARK");

#define PFX "SECMARK: "

static u8 mode;

static unsigned int
secmark_tg(struct sk_buff *skb, const struct net_device *in,
           const struct net_device *out, unsigned int hooknum,
           const struct xt_target *target, const void *targinfo)
{
	u32 secmark = 0;
	const struct xt_secmark_target_info *info = targinfo;

	BUG_ON(info->mode != mode);

	switch (mode) {
	case SECMARK_MODE_SEL:
		secmark = info->u.sel.selsid;
		break;

	default:
		BUG();
	}

	skb->secmark = secmark;
	return XT_CONTINUE;
}

static bool checkentry_selinux(struct xt_secmark_target_info *info)
{
	int err;
	struct xt_secmark_target_selinux_info *sel = &info->u.sel;

	sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0';

	err = selinux_string_to_sid(sel->selctx, &sel->selsid);
	if (err) {
		if (err == -EINVAL)
			printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
			       sel->selctx);
		return false;
	}

	if (!sel->selsid) {
		printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
		       sel->selctx);
		return false;
	}

	err = selinux_relabel_packet_permission(sel->selsid);
	if (err) {
		printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
		return false;
	}

	return true;
}

static bool
secmark_tg_check(const char *tablename, const void *entry,
                 const struct xt_target *target, void *targinfo,
                 unsigned int hook_mask)
{
	struct xt_secmark_target_info *info = targinfo;

	if (mode && mode != info->mode) {
		printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
		       "rules for mode %hu\n", mode, info->mode);
		return false;
	}

	switch (info->mode) {
	case SECMARK_MODE_SEL:
		if (!checkentry_selinux(info))
			return false;
		break;

	default:
		printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
		return false;
	}

	if (!mode)
		mode = info->mode;
	return true;
}

static struct xt_target secmark_tg_reg[] __read_mostly = {
	{
		.name		= "SECMARK",
		.family		= AF_INET,
		.checkentry	= secmark_tg_check,
		.target		= secmark_tg,
		.targetsize	= sizeof(struct xt_secmark_target_info),
		.table		= "mangle",
		.me		= THIS_MODULE,
	},
	{
		.name		= "SECMARK",
		.family		= AF_INET6,
		.checkentry	= secmark_tg_check,
		.target		= secmark_tg,
		.targetsize	= sizeof(struct xt_secmark_target_info),
		.table		= "mangle",
		.me		= THIS_MODULE,
	},
};

static int __init secmark_tg_init(void)
{
	return xt_register_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg));
}

static void __exit secmark_tg_exit(void)
{
	xt_unregister_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg));
}

module_init(secmark_tg_init);
module_exit(secmark_tg_exit);
Commit	Line	Data
5e6874cd JM	1	/*
	2	* Module for modifying the secmark field of the skb, for use by
	3	* security subsystems.
	4	*
	5	* Based on the nfmark match by:
	6	* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
	7	*
	8	* (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	*/
	15	#include <linux/module.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/selinux.h>
	18	#include <linux/netfilter/x_tables.h>
	19	#include <linux/netfilter/xt_SECMARK.h>
	20
	21	MODULE_LICENSE("GPL");
	22	MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
	23	MODULE_DESCRIPTION("ip[6]tables SECMARK modification module");
	24	MODULE_ALIAS("ipt_SECMARK");
	25	MODULE_ALIAS("ip6t_SECMARK");
	26
	27	#define PFX "SECMARK: "
	28
	29	static u8 mode;
	30
d3c5ee6d JE	31	static unsigned int
	32	secmark_tg(struct sk_buff skb, const struct net_device in,
	33	const struct net_device *out, unsigned int hooknum,
	34	const struct xt_target target, const void targinfo)
5e6874cd JM	35	{
	36	u32 secmark = 0;
	37	const struct xt_secmark_target_info *info = targinfo;
	38
	39	BUG_ON(info->mode != mode);
	40
	41	switch (mode) {
	42	case SECMARK_MODE_SEL:
	43	secmark = info->u.sel.selsid;
	44	break;
	45
	46	default:
	47	BUG();
	48	}
	49
3db05fea	50	skb->secmark = secmark;
5e6874cd JM	51	return XT_CONTINUE;
	52	}
	53
e1931b78	54	static bool checkentry_selinux(struct xt_secmark_target_info *info)
5e6874cd JM	55	{
	56	int err;
	57	struct xt_secmark_target_selinux_info *sel = &info->u.sel;
601e68e1	58
a280b899	59	sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0';
5e6874cd JM	60
	61	err = selinux_string_to_sid(sel->selctx, &sel->selsid);
	62	if (err) {
	63	if (err == -EINVAL)
	64	printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
	65	sel->selctx);
e1931b78	66	return false;
5e6874cd JM	67	}
	68
	69	if (!sel->selsid) {
	70	printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
	71	sel->selctx);
e1931b78	72	return false;
5e6874cd JM	73	}
	74
	75	err = selinux_relabel_packet_permission(sel->selsid);
	76	if (err) {
	77	printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
e1931b78	78	return false;
5e6874cd JM	79	}
5e6874cd JM	80
e1931b78	81	return true;
5e6874cd JM	82	}
5e6874cd JM	83
d3c5ee6d JE	84	static bool
	85	secmark_tg_check(const char tablename, const void entry,
	86	const struct xt_target target, void targinfo,
	87	unsigned int hook_mask)
5e6874cd JM	88	{
	89	struct xt_secmark_target_info *info = targinfo;
	90
	91	if (mode && mode != info->mode) {
	92	printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
	93	"rules for mode %hu\n", mode, info->mode);
e1931b78	94	return false;
5e6874cd JM	95	}
	96
	97	switch (info->mode) {
	98	case SECMARK_MODE_SEL:
	99	if (!checkentry_selinux(info))
e1931b78	100	return false;
5e6874cd JM	101	break;
	102
	103	default:
	104	printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
e1931b78	105	return false;
5e6874cd JM	106	}
	107
	108	if (!mode)
	109	mode = info->mode;
e1931b78	110	return true;
5e6874cd JM	111	}
5e6874cd JM	112
d3c5ee6d	113	static struct xt_target secmark_tg_reg[] __read_mostly = {
4470bbc7 PM	114	{
	115	.name = "SECMARK",
	116	.family = AF_INET,
d3c5ee6d JE	117	.checkentry = secmark_tg_check,
d3c5ee6d JE	118	.target = secmark_tg,
4470bbc7 PM	119	.targetsize = sizeof(struct xt_secmark_target_info),
	120	.table = "mangle",
	121	.me = THIS_MODULE,
	122	},
	123	{
	124	.name = "SECMARK",
	125	.family = AF_INET6,
d3c5ee6d JE	126	.checkentry = secmark_tg_check,
d3c5ee6d JE	127	.target = secmark_tg,
4470bbc7 PM	128	.targetsize = sizeof(struct xt_secmark_target_info),
	129	.table = "mangle",
	130	.me = THIS_MODULE,
	131	},
5e6874cd JM	132	};
5e6874cd JM	133
d3c5ee6d	134	static int __init secmark_tg_init(void)
5e6874cd	135	{
d3c5ee6d	136	return xt_register_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg));
5e6874cd JM	137	}
5e6874cd JM	138
d3c5ee6d	139	static void __exit secmark_tg_exit(void)
5e6874cd	140	{
d3c5ee6d	141	xt_unregister_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg));
5e6874cd JM	142	}
5e6874cd JM	143
d3c5ee6d JE	144	module_init(secmark_tg_init);
d3c5ee6d JE	145	module_exit(secmark_tg_exit);