[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 target(struct sk_buff **pskb, 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();
	}

	if ((*pskb)->secmark != secmark)
		(*pskb)->secmark = secmark;

	return XT_CONTINUE;
}

static int 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 0;
	}

	if (!sel->selsid) {
		printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
		       sel->selctx);
		return 0;
	}

	err = selinux_relabel_packet_permission(sel->selsid);
	if (err) {
		printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
		return 0;
	}

	return 1;
}

static int checkentry(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 0;
	}

	switch (info->mode) {
	case SECMARK_MODE_SEL:
		if (!checkentry_selinux(info))
			return 0;
		break;

	default:
		printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
		return 0;
	}

	if (!mode)
		mode = info->mode;
	return 1;
}

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

static int __init xt_secmark_init(void)
{
	return xt_register_targets(xt_secmark_target,
				   ARRAY_SIZE(xt_secmark_target));
}

static void __exit xt_secmark_fini(void)
{
	xt_unregister_targets(xt_secmark_target, ARRAY_SIZE(xt_secmark_target));
}

module_init(xt_secmark_init);
module_exit(xt_secmark_fini);
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
	31	static unsigned int target(struct sk_buff *pskb, const struct net_device in,
	32	const struct net_device *out, unsigned int hooknum,
	33	const struct xt_target *target,
fe1cb108	34	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
	50	if ((*pskb)->secmark != secmark)
	51	(*pskb)->secmark = secmark;
	52
	53	return XT_CONTINUE;
	54	}
	55
	56	static int checkentry_selinux(struct xt_secmark_target_info *info)
	57	{
	58	int err;
	59	struct xt_secmark_target_selinux_info *sel = &info->u.sel;
a280b899 JM	60
a280b899 JM	61	sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0';
5e6874cd JM	62
	63	err = selinux_string_to_sid(sel->selctx, &sel->selsid);
	64	if (err) {
	65	if (err == -EINVAL)
	66	printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
	67	sel->selctx);
	68	return 0;
	69	}
	70
	71	if (!sel->selsid) {
	72	printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
	73	sel->selctx);
	74	return 0;
	75	}
	76
	77	err = selinux_relabel_packet_permission(sel->selsid);
	78	if (err) {
	79	printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
	80	return 0;
	81	}
	82
	83	return 1;
	84	}
	85
	86	static int checkentry(const char tablename, const void entry,
	87	const struct xt_target target, void targinfo,
efa74165	88	unsigned int hook_mask)
5e6874cd JM	89	{
	90	struct xt_secmark_target_info *info = targinfo;
	91
	92	if (mode && mode != info->mode) {
	93	printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
	94	"rules for mode %hu\n", mode, info->mode);
	95	return 0;
	96	}
	97
	98	switch (info->mode) {
	99	case SECMARK_MODE_SEL:
	100	if (!checkentry_selinux(info))
	101	return 0;
	102	break;
	103
	104	default:
	105	printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
	106	return 0;
	107	}
	108
	109	if (!mode)
	110	mode = info->mode;
	111	return 1;
	112	}
	113
28094864	114	static struct xt_target xt_secmark_target[] = {
4470bbc7 PM	115	{
	116	.name = "SECMARK",
	117	.family = AF_INET,
	118	.checkentry = checkentry,
	119	.target = target,
	120	.targetsize = sizeof(struct xt_secmark_target_info),
	121	.table = "mangle",
	122	.me = THIS_MODULE,
	123	},
	124	{
	125	.name = "SECMARK",
	126	.family = AF_INET6,
	127	.checkentry = checkentry,
	128	.target = target,
	129	.targetsize = sizeof(struct xt_secmark_target_info),
	130	.table = "mangle",
	131	.me = THIS_MODULE,
	132	},
5e6874cd JM	133	};
	134
	135	static int __init xt_secmark_init(void)
	136	{
4470bbc7 PM	137	return xt_register_targets(xt_secmark_target,
4470bbc7 PM	138	ARRAY_SIZE(xt_secmark_target));
5e6874cd JM	139	}
	140
	141	static void __exit xt_secmark_fini(void)
	142	{
4470bbc7	143	xt_unregister_targets(xt_secmark_target, ARRAY_SIZE(xt_secmark_target));
5e6874cd JM	144	}
	145
	146	module_init(xt_secmark_init);
	147	module_exit(xt_secmark_fini);