net/netfilter/xt_MARK.c

/* This is a module which is used for setting the NFMARK field of an skb. */

/* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
 *
 * 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/ip.h>
#include <net/checksum.h>

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_MARK.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("ip[6]tables MARK modification module");
MODULE_ALIAS("ipt_MARK");
MODULE_ALIAS("ip6t_MARK");

static unsigned int
target_v0(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)
{
	const struct xt_mark_target_info *markinfo = targinfo;

	if((*pskb)->nfmark != markinfo->mark)
		(*pskb)->nfmark = markinfo->mark;

	return XT_CONTINUE;
}

static unsigned int
target_v1(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)
{
	const struct xt_mark_target_info_v1 *markinfo = targinfo;
	int mark = 0;

	switch (markinfo->mode) {
	case XT_MARK_SET:
		mark = markinfo->mark;
		break;
		
	case XT_MARK_AND:
		mark = (*pskb)->nfmark & markinfo->mark;
		break;
		
	case XT_MARK_OR:
		mark = (*pskb)->nfmark | markinfo->mark;
		break;
	}

	if((*pskb)->nfmark != mark)
		(*pskb)->nfmark = mark;

	return XT_CONTINUE;
}


static int
checkentry_v0(const char *tablename,
	      const void *entry,
	      const struct xt_target *target,
	      void *targinfo,
	      unsigned int targinfosize,
	      unsigned int hook_mask)
{
	struct xt_mark_target_info *markinfo = targinfo;

	if (markinfo->mark > 0xffffffff) {
		printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
		return 0;
	}
	return 1;
}

static int
checkentry_v1(const char *tablename,
	      const void *entry,
	      const struct xt_target *target,
	      void *targinfo,
	      unsigned int targinfosize,
	      unsigned int hook_mask)
{
	struct xt_mark_target_info_v1 *markinfo = targinfo;

	if (markinfo->mode != XT_MARK_SET
	    && markinfo->mode != XT_MARK_AND
	    && markinfo->mode != XT_MARK_OR) {
		printk(KERN_WARNING "MARK: unknown mode %u\n",
		       markinfo->mode);
		return 0;
	}
	if (markinfo->mark > 0xffffffff) {
		printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
		return 0;
	}
	return 1;
}

static struct xt_target xt_mark_target[] = {
	{
		.name		= "MARK",
		.family		= AF_INET,
		.revision	= 0,
		.checkentry	= checkentry_v0,
		.target		= target_v0,
		.targetsize	= sizeof(struct xt_mark_target_info),
		.table		= "mangle",
		.me		= THIS_MODULE,
	},
	{
		.name		= "MARK",
		.family		= AF_INET,
		.revision	= 1,
		.checkentry	= checkentry_v1,
		.target		= target_v1,
		.targetsize	= sizeof(struct xt_mark_target_info_v1),
		.table		= "mangle",
		.me		= THIS_MODULE,
	},
	{
		.name		= "MARK",
		.family		= AF_INET6,
		.revision	= 0,
		.checkentry	= checkentry_v0,
		.target		= target_v0,
		.targetsize	= sizeof(struct xt_mark_target_info),
		.table		= "mangle",
		.me		= THIS_MODULE,
	},
};

static int __init xt_mark_init(void)
{
	return xt_register_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
}

static void __exit xt_mark_fini(void)
{
	xt_unregister_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
}

module_init(xt_mark_init);
module_exit(xt_mark_fini);