[deliverable/linux.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>

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));
		skb->ignore_df = 1;
	}

	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(const struct nf_hook_ops *ops,
					  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_is_fragment(ip_hdr(skb))) {
		enum ip_defrag_users user =
			nf_ct_defrag_user(ops->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		= NFPROTO_IPV4,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP_PRI_CONNTRACK_DEFRAG,
	},
	{
		.hook           = ipv4_conntrack_defrag,
		.owner          = THIS_MODULE,
		.pf             = NFPROTO_IPV4,
		.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	24
73e4022f KK	25	static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
	26	{
	27	int err;
	28
	29	skb_orphan(skb);
	30
	31	local_bh_disable();
	32	err = ip_defrag(skb, user);
	33	local_bh_enable();
	34
895162b1	35	if (!err) {
73e4022f	36	ip_send_check(ip_hdr(skb));
60ff7467	37	skb->ignore_df = 1;
895162b1	38	}
73e4022f KK	39
	40	return err;
	41	}
	42
8fa9ff68 PM	43	static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
	44	struct sk_buff *skb)
	45	{
5d0aa2cc PM	46	u16 zone = NF_CT_DEFAULT_ZONE;
5d0aa2cc PM	47
37ee3d5b	48	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
5d0aa2cc PM	49	if (skb->nfct)
5d0aa2cc PM	50	zone = nf_ct_zone((struct nf_conn *)skb->nfct);
37ee3d5b	51	#endif
5d0aa2cc	52
8fa9ff68 PM	53	#ifdef CONFIG_BRIDGE_NETFILTER
	54	if (skb->nf_bridge &&
	55	skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
5d0aa2cc	56	return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
8fa9ff68 PM	57	#endif
8fa9ff68 PM	58	if (hooknum == NF_INET_PRE_ROUTING)
5d0aa2cc	59	return IP_DEFRAG_CONNTRACK_IN + zone;
8fa9ff68	60	else
5d0aa2cc	61	return IP_DEFRAG_CONNTRACK_OUT + zone;
8fa9ff68 PM	62	}
8fa9ff68 PM	63
795aa6ef	64	static unsigned int ipv4_conntrack_defrag(const struct nf_hook_ops *ops,
73e4022f KK	65	struct sk_buff *skb,
	66	const struct net_device *in,
	67	const struct net_device *out,
	68	int (okfn)(struct sk_buff ))
	69	{
cbdd769a	70	struct sock *sk = skb->sk;
7b2ff18e JO	71	struct inet_sock *inet = inet_sk(skb->sk);
7b2ff18e JO	72
cbdd769a JO	73	if (sk && (sk->sk_family == PF_INET) &&
cbdd769a JO	74	inet->nodefrag)
7b2ff18e JO	75	return NF_ACCEPT;
7b2ff18e JO	76
73e4022f	77	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
38f7ac3e	78	#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
73e4022f KK	79	/* Previously seen (loopback)? Ignore. Do this before
73e4022f KK	80	fragment check. */
b2a15a60	81	if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
73e4022f KK	82	return NF_ACCEPT;
73e4022f KK	83	#endif
38f7ac3e	84	#endif
73e4022f	85	/* Gather fragments. */
56f8a75c	86	if (ip_is_fragment(ip_hdr(skb))) {
795aa6ef PM	87	enum ip_defrag_users user =
	88	nf_ct_defrag_user(ops->hooknum, skb);
	89
8fa9ff68	90	if (nf_ct_ipv4_gather_frags(skb, user))
73e4022f KK	91	return NF_STOLEN;
	92	}
	93	return NF_ACCEPT;
	94	}
	95
	96	static struct nf_hook_ops ipv4_defrag_ops[] = {
	97	{
	98	.hook = ipv4_conntrack_defrag,
	99	.owner = THIS_MODULE,
89a48e35	100	.pf = NFPROTO_IPV4,
73e4022f KK	101	.hooknum = NF_INET_PRE_ROUTING,
	102	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	103	},
	104	{
	105	.hook = ipv4_conntrack_defrag,
	106	.owner = THIS_MODULE,
89a48e35	107	.pf = NFPROTO_IPV4,
73e4022f KK	108	.hooknum = NF_INET_LOCAL_OUT,
	109	.priority = NF_IP_PRI_CONNTRACK_DEFRAG,
	110	},
	111	};
	112
	113	static int __init nf_defrag_init(void)
	114	{
	115	return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	116	}
	117
	118	static void __exit nf_defrag_fini(void)
	119	{
	120	nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
	121	}
	122
	123	void nf_defrag_ipv4_enable(void)
	124	{
	125	}
	126	EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
	127
	128	module_init(nf_defrag_init);
	129	module_exit(nf_defrag_fini);
	130
	131	MODULE_LICENSE("GPL");