net/ipv6/xfrm6_tunnel.c - linux - Git at Google

 /*
  * Copyright (C)2003,2004 USAGI/WIDE Project
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * Authors	Mitsuru KANDA  <mk@linux-ipv6.org>
  * 		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
  *
  * Based on net/ipv4/xfrm4_tunnel.c
  *
  */
 #include <linux/module.h>
 #include <linux/xfrm.h>
 #include <linux/rculist.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
 #include <net/ipv6.h>
 #include <linux/ipv6.h>
 #include <linux/icmpv6.h>
 #include <linux/mutex.h>
 #include <net/netns/generic.h>

 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256

 #define XFRM6_TUNNEL_SPI_MIN	1
 #define XFRM6_TUNNEL_SPI_MAX	0xffffffff

 struct xfrm6_tunnel_net {
 	struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
 	struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
 	u32 spi;
 };

 static int xfrm6_tunnel_net_id __read_mostly;
 static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
 {
 	return net_generic(net, xfrm6_tunnel_net_id);
 }

 /*
  * xfrm_tunnel_spi things are for allocating unique id ("spi")
  * per xfrm_address_t.
  */
 struct xfrm6_tunnel_spi {
 	struct hlist_node	list_byaddr;
 	struct hlist_node	list_byspi;
 	xfrm_address_t		addr;
 	u32			spi;
 	atomic_t		refcnt;
 	struct rcu_head		rcu_head;
 };

 static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);

 static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;

 static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
 {
 	unsigned h;

 	h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]);
 	h ^= h >> 16;
 	h ^= h >> 8;
 	h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;

 	return h;
 }

 static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi)
 {
 	return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
 }


 static int __init xfrm6_tunnel_spi_init(void)
 {
 	xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
 						  sizeof(struct xfrm6_tunnel_spi),
 						  0, SLAB_HWCACHE_ALIGN,
 						  NULL);
 	if (!xfrm6_tunnel_spi_kmem)
 		return -ENOMEM;
 	return 0;
 }

 static void xfrm6_tunnel_spi_fini(void)
 {
 	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
 }

 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
 {
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	struct xfrm6_tunnel_spi *x6spi;
 	struct hlist_node *pos;

 	hlist_for_each_entry_rcu(x6spi, pos,
 			     &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
 			     list_byaddr) {
 		if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
 			return x6spi;
 	}

 	return NULL;
 }

 __be32 xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr)
 {
 	struct xfrm6_tunnel_spi *x6spi;
 	u32 spi;

 	rcu_read_lock_bh();
 	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
 	spi = x6spi ? x6spi->spi : 0;
 	rcu_read_unlock_bh();
 	return htonl(spi);
 }

 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);

 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
 {
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	struct xfrm6_tunnel_spi *x6spi;
 	int index = xfrm6_tunnel_spi_hash_byspi(spi);
 	struct hlist_node *pos;

 	hlist_for_each_entry(x6spi, pos,
 			     &xfrm6_tn->spi_byspi[index],
 			     list_byspi) {
 		if (x6spi->spi == spi)
 			return -1;
 	}
 	return index;
 }

 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
 {
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	u32 spi;
 	struct xfrm6_tunnel_spi *x6spi;
 	int index;

 	if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
 	    xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
 		xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
 	else
 		xfrm6_tn->spi++;

 	for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
 		index = __xfrm6_tunnel_spi_check(net, spi);
 		if (index >= 0)
 			goto alloc_spi;
 	}
 	for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
 		index = __xfrm6_tunnel_spi_check(net, spi);
 		if (index >= 0)
 			goto alloc_spi;
 	}
 	spi = 0;
 	goto out;
 alloc_spi:
 	xfrm6_tn->spi = spi;
 	x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
 	if (!x6spi)
 		goto out;

 	INIT_RCU_HEAD(&x6spi->rcu_head);
 	memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
 	x6spi->spi = spi;
 	atomic_set(&x6spi->refcnt, 1);

 	hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);

 	index = xfrm6_tunnel_spi_hash_byaddr(saddr);
 	hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
 out:
 	return spi;
 }

 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
 {
 	struct xfrm6_tunnel_spi *x6spi;
 	u32 spi;

 	spin_lock_bh(&xfrm6_tunnel_spi_lock);
 	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
 	if (x6spi) {
 		atomic_inc(&x6spi->refcnt);
 		spi = x6spi->spi;
 	} else
 		spi = __xfrm6_tunnel_alloc_spi(net, saddr);
 	spin_unlock_bh(&xfrm6_tunnel_spi_lock);

 	return htonl(spi);
 }

 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);

 static void x6spi_destroy_rcu(struct rcu_head *head)
 {
 	kmem_cache_free(xfrm6_tunnel_spi_kmem,
 			container_of(head, struct xfrm6_tunnel_spi, rcu_head));
 }

 void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
 {
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	struct xfrm6_tunnel_spi *x6spi;
 	struct hlist_node *pos, *n;

 	spin_lock_bh(&xfrm6_tunnel_spi_lock);

 	hlist_for_each_entry_safe(x6spi, pos, n,
 				  &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
 				  list_byaddr)
 	{
 		if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
 			if (atomic_dec_and_test(&x6spi->refcnt)) {
 				hlist_del_rcu(&x6spi->list_byaddr);
 				hlist_del_rcu(&x6spi->list_byspi);
 				call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
 				break;
 			}
 		}
 	}
 	spin_unlock_bh(&xfrm6_tunnel_spi_lock);
 }

 EXPORT_SYMBOL(xfrm6_tunnel_free_spi);

 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 {
 	skb_push(skb, -skb_network_offset(skb));
 	return 0;
 }

 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	return skb_network_header(skb)[IP6CB(skb)->nhoff];
 }

 static int xfrm6_tunnel_rcv(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
 	struct ipv6hdr *iph = ipv6_hdr(skb);
 	__be32 spi;

 	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&iph->saddr);
 	return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
 }

 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 			    u8 type, u8 code, int offset, __be32 info)
 {
 	/* xfrm6_tunnel native err handling */
 	switch (type) {
 	case ICMPV6_DEST_UNREACH:
 		switch (code) {
 		case ICMPV6_NOROUTE:
 		case ICMPV6_ADM_PROHIBITED:
 		case ICMPV6_NOT_NEIGHBOUR:
 		case ICMPV6_ADDR_UNREACH:
 		case ICMPV6_PORT_UNREACH:
 		default:
 			break;
 		}
 		break;
 	case ICMPV6_PKT_TOOBIG:
 		break;
 	case ICMPV6_TIME_EXCEED:
 		switch (code) {
 		case ICMPV6_EXC_HOPLIMIT:
 			break;
 		case ICMPV6_EXC_FRAGTIME:
 		default:
 			break;
 		}
 		break;
 	case ICMPV6_PARAMPROB:
 		switch (code) {
 		case ICMPV6_HDR_FIELD: break;
 		case ICMPV6_UNK_NEXTHDR: break;
 		case ICMPV6_UNK_OPTION: break;
 		}
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 static int xfrm6_tunnel_init_state(struct xfrm_state *x)
 {
 	if (x->props.mode != XFRM_MODE_TUNNEL)
 		return -EINVAL;

 	if (x->encap)
 		return -EINVAL;

 	x->props.header_len = sizeof(struct ipv6hdr);

 	return 0;
 }

 static void xfrm6_tunnel_destroy(struct xfrm_state *x)
 {
 	struct net *net = xs_net(x);

 	xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
 }

 static const struct xfrm_type xfrm6_tunnel_type = {
 	.description	= "IP6IP6",
 	.owner          = THIS_MODULE,
 	.proto		= IPPROTO_IPV6,
 	.init_state	= xfrm6_tunnel_init_state,
 	.destructor	= xfrm6_tunnel_destroy,
 	.input		= xfrm6_tunnel_input,
 	.output		= xfrm6_tunnel_output,
 };

 static struct xfrm6_tunnel xfrm6_tunnel_handler = {
 	.handler	= xfrm6_tunnel_rcv,
 	.err_handler	= xfrm6_tunnel_err,
 	.priority	= 2,
 };

 static struct xfrm6_tunnel xfrm46_tunnel_handler = {
 	.handler	= xfrm6_tunnel_rcv,
 	.err_handler	= xfrm6_tunnel_err,
 	.priority	= 2,
 };

 static int __net_init xfrm6_tunnel_net_init(struct net *net)
 {
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	unsigned int i;

 	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
 		INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
 	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
 		INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
 	xfrm6_tn->spi = 0;

 	return 0;
 }

 static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
 {
 }

 static struct pernet_operations xfrm6_tunnel_net_ops = {
 	.init	= xfrm6_tunnel_net_init,
 	.exit	= xfrm6_tunnel_net_exit,
 	.id	= &xfrm6_tunnel_net_id,
 	.size	= sizeof(struct xfrm6_tunnel_net),
 };

 static int __init xfrm6_tunnel_init(void)
 {
 	int rv;

 	rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
 	if (rv < 0)
 		goto err;
 	rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
 	if (rv < 0)
 		goto unreg;
 	rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
 	if (rv < 0)
 		goto dereg6;
 	rv = xfrm6_tunnel_spi_init();
 	if (rv < 0)
 		goto dereg46;
 	rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
 	if (rv < 0)
 		goto deregspi;
 	return 0;

 deregspi:
 	xfrm6_tunnel_spi_fini();
 dereg46:
 	xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
 dereg6:
 	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
 unreg:
 	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
 err:
 	return rv;
 }

 static void __exit xfrm6_tunnel_fini(void)
 {
 	unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
 	xfrm6_tunnel_spi_fini();
 	xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
 	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
 	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
 }

 module_init(xfrm6_tunnel_init);
 module_exit(xfrm6_tunnel_fini);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);
	/*
	* Copyright (C)2003,2004 USAGI/WIDE Project
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* Authors Mitsuru KANDA <mk@linux-ipv6.org>
	* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
	*
	* Based on net/ipv4/xfrm4_tunnel.c
	*
	*/
	#include <linux/module.h>
	#include <linux/xfrm.h>
	#include <linux/rculist.h>
	#include <net/ip.h>
	#include <net/xfrm.h>
	#include <net/ipv6.h>
	#include <linux/ipv6.h>
	#include <linux/icmpv6.h>
	#include <linux/mutex.h>
	#include <net/netns/generic.h>

	#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
	#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256

	#define XFRM6_TUNNEL_SPI_MIN 1
	#define XFRM6_TUNNEL_SPI_MAX 0xffffffff

	struct xfrm6_tunnel_net {
	struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
	struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
	u32 spi;
	};

	static int xfrm6_tunnel_net_id __read_mostly;
	static inline struct xfrm6_tunnel_net xfrm6_tunnel_pernet(struct net net)
	{
	return net_generic(net, xfrm6_tunnel_net_id);
	}

	/*
	* xfrm_tunnel_spi things are for allocating unique id ("spi")
	* per xfrm_address_t.
	*/
	struct xfrm6_tunnel_spi {
	struct hlist_node list_byaddr;
	struct hlist_node list_byspi;
	xfrm_address_t addr;
	u32 spi;
	atomic_t refcnt;
	struct rcu_head rcu_head;
	};

	static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);

	static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;

	static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
	{
	unsigned h;

	h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]);
	h ^= h >> 16;
	h ^= h >> 8;
	h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;

	return h;
	}

	static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi)
	{
	return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
	}


	static int __init xfrm6_tunnel_spi_init(void)
	{
	xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
	sizeof(struct xfrm6_tunnel_spi),
	0, SLAB_HWCACHE_ALIGN,
	NULL);
	if (!xfrm6_tunnel_spi_kmem)
	return -ENOMEM;
	return 0;
	}

	static void xfrm6_tunnel_spi_fini(void)
	{
	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
	}

	static struct xfrm6_tunnel_spi __xfrm6_tunnel_spi_lookup(struct net net, xfrm_address_t *saddr)
	{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node *pos;

	hlist_for_each_entry_rcu(x6spi, pos,
	&xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
	list_byaddr) {
	if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
	return x6spi;
	}

	return NULL;
	}

	__be32 xfrm6_tunnel_spi_lookup(struct net net, xfrm_address_t saddr)
	{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	rcu_read_lock_bh();
	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
	spi = x6spi ? x6spi->spi : 0;
	rcu_read_unlock_bh();
	return htonl(spi);
	}

	EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);

	static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
	{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;
	int index = xfrm6_tunnel_spi_hash_byspi(spi);
	struct hlist_node *pos;

	hlist_for_each_entry(x6spi, pos,
	&xfrm6_tn->spi_byspi[index],
	list_byspi) {
	if (x6spi->spi == spi)
	return -1;
	}
	return index;
	}

	static u32 __xfrm6_tunnel_alloc_spi(struct net net, xfrm_address_t saddr)
	{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	u32 spi;
	struct xfrm6_tunnel_spi *x6spi;
	int index;

	if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN \|\|
	xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
	xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
	else
	xfrm6_tn->spi++;

	for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
	index = __xfrm6_tunnel_spi_check(net, spi);
	if (index >= 0)
	goto alloc_spi;
	}
	for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
	index = __xfrm6_tunnel_spi_check(net, spi);
	if (index >= 0)
	goto alloc_spi;
	}
	spi = 0;
	goto out;
	alloc_spi:
	xfrm6_tn->spi = spi;
	x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
	if (!x6spi)
	goto out;

	INIT_RCU_HEAD(&x6spi->rcu_head);
	memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
	x6spi->spi = spi;
	atomic_set(&x6spi->refcnt, 1);

	hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);

	index = xfrm6_tunnel_spi_hash_byaddr(saddr);
	hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
	out:
	return spi;
	}

	__be32 xfrm6_tunnel_alloc_spi(struct net net, xfrm_address_t saddr)
	{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	spin_lock_bh(&xfrm6_tunnel_spi_lock);
	x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
	if (x6spi) {
	atomic_inc(&x6spi->refcnt);
	spi = x6spi->spi;
	} else
	spi = __xfrm6_tunnel_alloc_spi(net, saddr);
	spin_unlock_bh(&xfrm6_tunnel_spi_lock);

	return htonl(spi);
	}

	EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);

	static void x6spi_destroy_rcu(struct rcu_head *head)
	{
	kmem_cache_free(xfrm6_tunnel_spi_kmem,
	container_of(head, struct xfrm6_tunnel_spi, rcu_head));
	}

	void xfrm6_tunnel_free_spi(struct net net, xfrm_address_t saddr)
	{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node pos, n;

	spin_lock_bh(&xfrm6_tunnel_spi_lock);

	hlist_for_each_entry_safe(x6spi, pos, n,
	&xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
	list_byaddr)
	{
	if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
	if (atomic_dec_and_test(&x6spi->refcnt)) {
	hlist_del_rcu(&x6spi->list_byaddr);
	hlist_del_rcu(&x6spi->list_byspi);
	call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
	break;
	}
	}
	}
	spin_unlock_bh(&xfrm6_tunnel_spi_lock);
	}

	EXPORT_SYMBOL(xfrm6_tunnel_free_spi);

	static int xfrm6_tunnel_output(struct xfrm_state x, struct sk_buff skb)
	{
	skb_push(skb, -skb_network_offset(skb));
	return 0;
	}

	static int xfrm6_tunnel_input(struct xfrm_state x, struct sk_buff skb)
	{
	return skb_network_header(skb)[IP6CB(skb)->nhoff];
	}

	static int xfrm6_tunnel_rcv(struct sk_buff *skb)
	{
	struct net *net = dev_net(skb->dev);
	struct ipv6hdr *iph = ipv6_hdr(skb);
	__be32 spi;

	spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&iph->saddr);
	return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
	}

	static int xfrm6_tunnel_err(struct sk_buff skb, struct inet6_skb_parm opt,
	u8 type, u8 code, int offset, __be32 info)
	{
	/* xfrm6_tunnel native err handling */
	switch (type) {
	case ICMPV6_DEST_UNREACH:
	switch (code) {
	case ICMPV6_NOROUTE:
	case ICMPV6_ADM_PROHIBITED:
	case ICMPV6_NOT_NEIGHBOUR:
	case ICMPV6_ADDR_UNREACH:
	case ICMPV6_PORT_UNREACH:
	default:
	break;
	}
	break;
	case ICMPV6_PKT_TOOBIG:
	break;
	case ICMPV6_TIME_EXCEED:
	switch (code) {
	case ICMPV6_EXC_HOPLIMIT:
	break;
	case ICMPV6_EXC_FRAGTIME:
	default:
	break;
	}
	break;
	case ICMPV6_PARAMPROB:
	switch (code) {
	case ICMPV6_HDR_FIELD: break;
	case ICMPV6_UNK_NEXTHDR: break;
	case ICMPV6_UNK_OPTION: break;
	}
	break;
	default:
	break;
	}

	return 0;
	}

	static int xfrm6_tunnel_init_state(struct xfrm_state *x)
	{
	if (x->props.mode != XFRM_MODE_TUNNEL)
	return -EINVAL;

	if (x->encap)
	return -EINVAL;

	x->props.header_len = sizeof(struct ipv6hdr);

	return 0;
	}

	static void xfrm6_tunnel_destroy(struct xfrm_state *x)
	{
	struct net *net = xs_net(x);

	xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
	}

	static const struct xfrm_type xfrm6_tunnel_type = {
	.description = "IP6IP6",
	.owner = THIS_MODULE,
	.proto = IPPROTO_IPV6,
	.init_state = xfrm6_tunnel_init_state,
	.destructor = xfrm6_tunnel_destroy,
	.input = xfrm6_tunnel_input,
	.output = xfrm6_tunnel_output,
	};

	static struct xfrm6_tunnel xfrm6_tunnel_handler = {
	.handler = xfrm6_tunnel_rcv,
	.err_handler = xfrm6_tunnel_err,
	.priority = 2,
	};

	static struct xfrm6_tunnel xfrm46_tunnel_handler = {
	.handler = xfrm6_tunnel_rcv,
	.err_handler = xfrm6_tunnel_err,
	.priority = 2,
	};

	static int __net_init xfrm6_tunnel_net_init(struct net *net)
	{
	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
	unsigned int i;

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
	INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
	INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
	xfrm6_tn->spi = 0;

	return 0;
	}

	static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
	{
	}

	static struct pernet_operations xfrm6_tunnel_net_ops = {
	.init = xfrm6_tunnel_net_init,
	.exit = xfrm6_tunnel_net_exit,
	.id = &xfrm6_tunnel_net_id,
	.size = sizeof(struct xfrm6_tunnel_net),
	};

	static int __init xfrm6_tunnel_init(void)
	{
	int rv;

	rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
	if (rv < 0)
	goto err;
	rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
	if (rv < 0)
	goto unreg;
	rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
	if (rv < 0)
	goto dereg6;
	rv = xfrm6_tunnel_spi_init();
	if (rv < 0)
	goto dereg46;
	rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
	if (rv < 0)
	goto deregspi;
	return 0;

	deregspi:
	xfrm6_tunnel_spi_fini();
	dereg46:
	xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
	dereg6:
	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
	unreg:
	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
	err:
	return rv;
	}

	static void __exit xfrm6_tunnel_fini(void)
	{
	unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
	xfrm6_tunnel_spi_fini();
	xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
	xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
	}

	module_init(xfrm6_tunnel_init);
	module_exit(xfrm6_tunnel_fini);
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);