[net-next-2.6.git] / net / ipv4 / netfilter / nf_defrag_ipv4.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 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.
 */

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/route.h>
#include <net/ip.h>

#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
#include <net/netfilter/nf_conntrack.h>

/* Returns new sk_buff, or NULL */
static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
{
	int err;

	skb_orphan(skb);

	local_bh_disable();
	err = ip_defrag(skb, user);
	local_bh_enable();

	if (!err)
		ip_send_check(ip_hdr(skb));

	return err;
}

static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
					      struct sk_buff *skb)
{
	u16 zone = NF_CT_DEFAULT_ZONE;

	if (skb->nfct)
		zone = nf_ct_zone((struct nf_conn *)skb->nfct);

#ifdef CONFIG_BRIDGE_NETFILTER
	if (skb->nf_bridge &&
	    skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
		return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
#endif
	if (hooknum == NF_INET_PRE_ROUTING)
		return IP_DEFRAG_CONNTRACK_IN + zone;
	else
		return IP_DEFRAG_CONNTRACK_OUT + zone;
}

static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
					  struct sk_buff *skb,
					  const struct net_device *in,
					  const struct net_device *out,
					  int (*okfn)(struct sk_buff *))
{
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
	/* Previously seen (loopback)?  Ignore.  Do this before
	   fragment check. */
	if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
		return NF_ACCEPT;
#endif
#endif
	/* Gather fragments. */
	if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
		enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb);
		if (nf_ct_ipv4_gather_frags(skb, user))
			return NF_STOLEN;
	}
	return NF_ACCEPT;
}

static struct nf_hook_ops ipv4_defrag_ops[] = {
	{
		.hook		= ipv4_conntrack_defrag,
		.owner		= THIS_MODULE,
		.pf		= PF_INET,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP_PRI_CONNTRACK_DEFRAG,
	},
	{
		.hook           = ipv4_conntrack_defrag,
		.owner          = THIS_MODULE,
		.pf             = PF_INET,
		.hooknum        = NF_INET_LOCAL_OUT,
		.priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
	},
};

static int __init nf_defrag_init(void)
{
	return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
}

static void __exit nf_defrag_fini(void)
{
	nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
}

void nf_defrag_ipv4_enable(void)
{
}
EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);

module_init(nf_defrag_init);
module_exit(nf_defrag_fini);

MODULE_LICENSE("GPL");
Commit	Line	Data
73e4022f KK	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/types.h>
	10	#include <linux/ip.h>
	11	#include <linux/netfilter.h>
	12	#include <linux/module.h>
	13	#include <linux/skbuff.h>
	14	#include <net/route.h>
	15	#include <net/ip.h>
	16
8fa9ff68	17	#include <linux/netfilter_bridge.h>
73e4022f	18	#include <linux/netfilter_ipv4.h>
5d0aa2cc	19	#include <net/netfilter/nf_conntrack_zones.h>
73e4022f	20	#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
76780373	21	#include <net/netfilter/nf_conntrack.h>
73e4022f KK	22
	23	/* Returns new sk_buff, or NULL */
	24	static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
	25	{
	26	int err;
	27
	28	skb_orphan(skb);
	29
	30	local_bh_disable();
	31	err = ip_defrag(skb, user);
	32	local_bh_enable();
	33
	34	if (!err)
	35	ip_send_check(ip_hdr(skb));
	36
	37	return err;
	38	}
	39
8fa9ff68 PM	40	static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
	41	struct sk_buff *skb)
	42	{
5d0aa2cc PM	43	u16 zone = NF_CT_DEFAULT_ZONE;
	44
	45	if (skb->nfct)
	46	zone = nf_ct_zone((struct nf_conn *)skb->nfct);
	47
8fa9ff68 PM	48	#ifdef CONFIG_BRIDGE_NETFILTER
	49	if (skb->nf_bridge &&
	50	skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
5d0aa2cc	51	return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
8fa9ff68 PM	52	#endif
8fa9ff68 PM	53	if (hooknum == NF_INET_PRE_ROUTING)
5d0aa2cc	54	return IP_DEFRAG_CONNTRACK_IN + zone;
8fa9ff68	55	else
5d0aa2cc	56	return IP_DEFRAG_CONNTRACK_OUT + zone;
8fa9ff68 PM	57	}
8fa9ff68 PM	58
73e4022f KK	59	static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
	60	struct sk_buff *skb,
	61	const struct net_device *in,
	62	const struct net_device *out,
	63	int (okfn)(struct sk_buff ))
	64	{
	65	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
38f7ac3e	66	#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
73e4022f KK	67	/* Previously seen (loopback)? Ignore. Do this before
73e4022f KK	68	fragment check. */
b2a15a60	69	if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
73e4022f KK	70	return NF_ACCEPT;
73e4022f KK	71	#endif
38f7ac3e	72	#endif
73e4022f KK	73	/* Gather fragments. */
73e4022f KK	74	if (ip_hdr(skb)->frag_off & htons(IP_MF \| IP_OFFSET)) {
8fa9ff68 PM	75	enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb);
8fa9ff68 PM	76	if (nf_ct_ipv4_gather_frags(skb, user))
73e4022f KK	77	return NF_STOLEN;
	78	}
	79	return NF_ACCEPT;
	80	}
	81
	82	static struct nf_hook_ops ipv4_defrag_ops[] = {
	83	{
	84	.hook = ipv4_conntrack_defrag,
	85	.owner = THIS_MODULE,
	86	.pf = PF_INET,
	87	.hooknum = NF_INET_PRE_ROUTING,
	88	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	89	},
	90	{
	91	.hook = ipv4_conntrack_defrag,
	92	.owner = THIS_MODULE,
	93	.pf = PF_INET,
	94	.hooknum = NF_INET_LOCAL_OUT,
	95	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	96	},
	97	};
	98
	99	static int __init nf_defrag_init(void)
	100	{
	101	return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	102	}
	103
	104	static void __exit nf_defrag_fini(void)
	105	{
	106	nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	107	}
	108
	109	void nf_defrag_ipv4_enable(void)
	110	{
	111	}
	112	EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
	113
	114	module_init(nf_defrag_init);
	115	module_exit(nf_defrag_fini);
	116
	117	MODULE_LICENSE("GPL");