[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/ipv4/nf_defrag_ipv4.h>
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#include <net/netfilter/nf_conntrack.h>
#endif
#include <net/netfilter/nf_conntrack_zones.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 defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
	if (skb->nfct)
		zone = nf_ct_zone((struct nf_conn *)skb->nfct);
#endif

#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 *))
{
	struct sock *sk = skb->sk;
	struct inet_sock *inet = inet_sk(skb->sk);

	if (sk && (sk->sk_family == PF_INET) &&
	    inet->nodefrag)
		return NF_ACCEPT;

#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 KK	18	#include <linux/netfilter_ipv4.h>
73e4022f KK	19	#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
37ee3d5b	20	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
76780373	21	#include <net/netfilter/nf_conntrack.h>
37ee3d5b PM	22	#endif
37ee3d5b PM	23	#include <net/netfilter/nf_conntrack_zones.h>
73e4022f KK	24
	25	/* Returns new sk_buff, or NULL */
	26	static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
	27	{
	28	int err;
	29
	30	skb_orphan(skb);
	31
	32	local_bh_disable();
	33	err = ip_defrag(skb, user);
	34	local_bh_enable();
	35
	36	if (!err)
	37	ip_send_check(ip_hdr(skb));
	38
	39	return err;
	40	}
	41
8fa9ff68 PM	42	static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
	43	struct sk_buff *skb)
	44	{
5d0aa2cc PM	45	u16 zone = NF_CT_DEFAULT_ZONE;
5d0aa2cc PM	46
37ee3d5b	47	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
5d0aa2cc PM	48	if (skb->nfct)
5d0aa2cc PM	49	zone = nf_ct_zone((struct nf_conn *)skb->nfct);
37ee3d5b	50	#endif
5d0aa2cc	51
8fa9ff68 PM	52	#ifdef CONFIG_BRIDGE_NETFILTER
	53	if (skb->nf_bridge &&
	54	skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
5d0aa2cc	55	return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
8fa9ff68 PM	56	#endif
8fa9ff68 PM	57	if (hooknum == NF_INET_PRE_ROUTING)
5d0aa2cc	58	return IP_DEFRAG_CONNTRACK_IN + zone;
8fa9ff68	59	else
5d0aa2cc	60	return IP_DEFRAG_CONNTRACK_OUT + zone;
8fa9ff68 PM	61	}
8fa9ff68 PM	62
73e4022f KK	63	static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
	64	struct sk_buff *skb,
	65	const struct net_device *in,
	66	const struct net_device *out,
	67	int (okfn)(struct sk_buff ))
	68	{
cbdd769a	69	struct sock *sk = skb->sk;
7b2ff18e JO	70	struct inet_sock *inet = inet_sk(skb->sk);
7b2ff18e JO	71
cbdd769a JO	72	if (sk && (sk->sk_family == PF_INET) &&
cbdd769a JO	73	inet->nodefrag)
7b2ff18e JO	74	return NF_ACCEPT;
7b2ff18e JO	75
73e4022f	76	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
38f7ac3e	77	#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
73e4022f KK	78	/* Previously seen (loopback)? Ignore. Do this before
73e4022f KK	79	fragment check. */
b2a15a60	80	if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
73e4022f KK	81	return NF_ACCEPT;
73e4022f KK	82	#endif
38f7ac3e	83	#endif
73e4022f KK	84	/* Gather fragments. */
73e4022f KK	85	if (ip_hdr(skb)->frag_off & htons(IP_MF \| IP_OFFSET)) {
8fa9ff68 PM	86	enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb);
8fa9ff68 PM	87	if (nf_ct_ipv4_gather_frags(skb, user))
73e4022f KK	88	return NF_STOLEN;
	89	}
	90	return NF_ACCEPT;
	91	}
	92
	93	static struct nf_hook_ops ipv4_defrag_ops[] = {
	94	{
	95	.hook = ipv4_conntrack_defrag,
	96	.owner = THIS_MODULE,
	97	.pf = PF_INET,
	98	.hooknum = NF_INET_PRE_ROUTING,
	99	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	100	},
	101	{
	102	.hook = ipv4_conntrack_defrag,
	103	.owner = THIS_MODULE,
	104	.pf = PF_INET,
	105	.hooknum = NF_INET_LOCAL_OUT,
	106	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	107	},
	108	};
	109
	110	static int __init nf_defrag_init(void)
	111	{
	112	return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	113	}
	114
	115	static void __exit nf_defrag_fini(void)
	116	{
	117	nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	118	}
	119
	120	void nf_defrag_ipv4_enable(void)
	121	{
	122	}
	123	EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
	124
	125	module_init(nf_defrag_init);
	126	module_exit(nf_defrag_fini);
	127
	128	MODULE_LICENSE("GPL");