net/ipv6/mip6.c - SHIFTPHONES/kernel/shift/mainline - Gitiles

 /*
  * Copyright (C)2003-2006 Helsinki University of Technology
  * Copyright (C)2003-2006 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:
  *	Noriaki TAKAMIYA @USAGI
  *	Masahide NAKAMURA @USAGI
  */

 #include <linux/config.h>
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ipv6.h>
 #include <net/ipv6.h>
 #include <net/xfrm.h>
 #include <net/mip6.h>

 static xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr)
 {
 	return x->coaddr;
 }

 static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
 {
 	return (n - len + 16) & 0x7;
 }

 static inline void *mip6_padn(__u8 *data, __u8 padlen)
 {
 	if (!data)
 		return NULL;
 	if (padlen == 1) {
 		data[0] = MIP6_OPT_PAD_1;
 	} else if (padlen > 1) {
 		data[0] = MIP6_OPT_PAD_N;
 		data[1] = padlen - 2;
 		if (padlen > 2)
 			memset(data+2, 0, data[1]);
 	}
 	return data + padlen;
 }

 static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	struct ipv6hdr *iph = skb->nh.ipv6h;
 	struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;

 	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
 	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
 		return -ENOENT;

 	return destopt->nexthdr;
 }

 /* Destination Option Header is inserted.
  * IP Header's src address is replaced with Home Address Option in
  * Destination Option Header.
  */
 static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
 {
 	struct ipv6hdr *iph;
 	struct ipv6_destopt_hdr *dstopt;
 	struct ipv6_destopt_hao *hao;
 	u8 nexthdr;
 	int len;

 	iph = (struct ipv6hdr *)skb->data;
 	iph->payload_len = htons(skb->len - sizeof(*iph));

 	nexthdr = *skb->nh.raw;
 	*skb->nh.raw = IPPROTO_DSTOPTS;

 	dstopt = (struct ipv6_destopt_hdr *)skb->h.raw;
 	dstopt->nexthdr = nexthdr;

 	hao = mip6_padn((char *)(dstopt + 1),
 			calc_padlen(sizeof(*dstopt), 6));

 	hao->type = IPV6_TLV_HAO;
 	hao->length = sizeof(*hao) - 2;
 	BUG_TRAP(hao->length == 16);

 	len = ((char *)hao - (char *)dstopt) + sizeof(*hao);

 	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
 	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));

 	BUG_TRAP(len == x->props.header_len);
 	dstopt->hdrlen = (x->props.header_len >> 3) - 1;

 	return 0;
 }

 static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
 			       u8 **nexthdr)
 {
 	u16 offset = sizeof(struct ipv6hdr);
 	struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
 	unsigned int packet_len = skb->tail - skb->nh.raw;
 	int found_rhdr = 0;

 	*nexthdr = &skb->nh.ipv6h->nexthdr;

 	while (offset + 1 <= packet_len) {

 		switch (**nexthdr) {
 		case NEXTHDR_HOP:
 			break;
 		case NEXTHDR_ROUTING:
 			found_rhdr = 1;
 			break;
 		case NEXTHDR_DEST:
 			/*
 			 * HAO MUST NOT appear more than once.
 			 * XXX: It is better to try to find by the end of
 			 * XXX: packet if HAO exists.
 			 */
 			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
 				LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
 				return offset;
 			}

 			if (found_rhdr)
 				return offset;

 			break;
 		default:
 			return offset;
 		}

 		offset += ipv6_optlen(exthdr);
 		*nexthdr = &exthdr->nexthdr;
 		exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
 	}

 	return offset;
 }

 static int mip6_destopt_init_state(struct xfrm_state *x)
 {
 	if (x->id.spi) {
 		printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
 		       x->id.spi);
 		return -EINVAL;
 	}
 	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
 		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
 		       __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
 		return -EINVAL;
 	}

 	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
 		calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
 		sizeof(struct ipv6_destopt_hao);
 	BUG_TRAP(x->props.header_len == 24);

 	return 0;
 }

 /*
  * Do nothing about destroying since it has no specific operation for
  * destination options header unlike IPsec protocols.
  */
 static void mip6_destopt_destroy(struct xfrm_state *x)
 {
 }

 static struct xfrm_type mip6_destopt_type =
 {
 	.description	= "MIP6DESTOPT",
 	.owner		= THIS_MODULE,
 	.proto	     	= IPPROTO_DSTOPTS,
 	.flags		= XFRM_TYPE_NON_FRAGMENT,
 	.init_state	= mip6_destopt_init_state,
 	.destructor	= mip6_destopt_destroy,
 	.input		= mip6_destopt_input,
 	.output		= mip6_destopt_output,
 	.hdr_offset	= mip6_destopt_offset,
 	.local_addr	= mip6_xfrm_addr,
 };

 static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;

 	if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
 	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
 		return -ENOENT;

 	return rt2->rt_hdr.nexthdr;
 }

 /* Routing Header type 2 is inserted.
  * IP Header's dst address is replaced with Routing Header's Home Address.
  */
 static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
 {
 	struct ipv6hdr *iph;
 	struct rt2_hdr *rt2;
 	u8 nexthdr;

 	iph = (struct ipv6hdr *)skb->data;
 	iph->payload_len = htons(skb->len - sizeof(*iph));

 	nexthdr = *skb->nh.raw;
 	*skb->nh.raw = IPPROTO_ROUTING;

 	rt2 = (struct rt2_hdr *)skb->h.raw;
 	rt2->rt_hdr.nexthdr = nexthdr;
 	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
 	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
 	rt2->rt_hdr.segments_left = 1;
 	memset(&rt2->reserved, 0, sizeof(rt2->reserved));

 	BUG_TRAP(rt2->rt_hdr.hdrlen == 2);

 	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
 	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));

 	return 0;
 }

 static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
 			     u8 **nexthdr)
 {
 	u16 offset = sizeof(struct ipv6hdr);
 	struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
 	unsigned int packet_len = skb->tail - skb->nh.raw;
 	int found_rhdr = 0;

 	*nexthdr = &skb->nh.ipv6h->nexthdr;

 	while (offset + 1 <= packet_len) {

 		switch (**nexthdr) {
 		case NEXTHDR_HOP:
 			break;
 		case NEXTHDR_ROUTING:
 			if (offset + 3 <= packet_len) {
 				struct ipv6_rt_hdr *rt;
 				rt = (struct ipv6_rt_hdr *)(skb->nh.raw + offset);
 				if (rt->type != 0)
 					return offset;
 			}
 			found_rhdr = 1;
 			break;
 		case NEXTHDR_DEST:
 			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
 				return offset;

 			if (found_rhdr)
 				return offset;

 			break;
 		default:
 			return offset;
 		}

 		offset += ipv6_optlen(exthdr);
 		*nexthdr = &exthdr->nexthdr;
 		exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
 	}

 	return offset;
 }

 static int mip6_rthdr_init_state(struct xfrm_state *x)
 {
 	if (x->id.spi) {
 		printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
 		       x->id.spi);
 		return -EINVAL;
 	}
 	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
 		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
 		       __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
 		return -EINVAL;
 	}

 	x->props.header_len = sizeof(struct rt2_hdr);

 	return 0;
 }

 /*
  * Do nothing about destroying since it has no specific operation for routing
  * header type 2 unlike IPsec protocols.
  */
 static void mip6_rthdr_destroy(struct xfrm_state *x)
 {
 }

 static struct xfrm_type mip6_rthdr_type =
 {
 	.description	= "MIP6RT",
 	.owner		= THIS_MODULE,
 	.proto	     	= IPPROTO_ROUTING,
 	.flags		= XFRM_TYPE_NON_FRAGMENT,
 	.init_state	= mip6_rthdr_init_state,
 	.destructor	= mip6_rthdr_destroy,
 	.input		= mip6_rthdr_input,
 	.output		= mip6_rthdr_output,
 	.hdr_offset	= mip6_rthdr_offset,
 	.remote_addr	= mip6_xfrm_addr,
 };

 int __init mip6_init(void)
 {
 	printk(KERN_INFO "Mobile IPv6\n");

 	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
 		printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
 		goto mip6_destopt_xfrm_fail;
 	}
 	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
 		printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
 		goto mip6_rthdr_xfrm_fail;
 	}
 	return 0;

  mip6_rthdr_xfrm_fail:
 	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
  mip6_destopt_xfrm_fail:
 	return -EAGAIN;
 }

 void __exit mip6_fini(void)
 {
 	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
 		printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
 	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
 		printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
 }
	/*
	* Copyright (C)2003-2006 Helsinki University of Technology
	* Copyright (C)2003-2006 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:
	* Noriaki TAKAMIYA @USAGI
	* Masahide NAKAMURA @USAGI
	*/

	#include <linux/config.h>
	#include <linux/module.h>
	#include <linux/skbuff.h>
	#include <linux/ipv6.h>
	#include <net/ipv6.h>
	#include <net/xfrm.h>
	#include <net/mip6.h>

	static xfrm_address_t mip6_xfrm_addr(struct xfrm_state x, xfrm_address_t *addr)
	{
	return x->coaddr;
	}

	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	{
	return (n - len + 16) & 0x7;
	}

	static inline void mip6_padn(__u8 data, __u8 padlen)
	{
	if (!data)
	return NULL;
	if (padlen == 1) {
	data[0] = MIP6_OPT_PAD_1;
	} else if (padlen > 1) {
	data[0] = MIP6_OPT_PAD_N;
	data[1] = padlen - 2;
	if (padlen > 2)
	memset(data+2, 0, data[1]);
	}
	return data + padlen;
	}

	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
	{
	struct ipv6hdr *iph = skb->nh.ipv6h;
	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;

	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	return -ENOENT;

	return destopt->nexthdr;
	}

	/* Destination Option Header is inserted.
	* IP Header's src address is replaced with Home Address Option in
	* Destination Option Header.
	*/
	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	{
	struct ipv6hdr *iph;
	struct ipv6_destopt_hdr *dstopt;
	struct ipv6_destopt_hao *hao;
	u8 nexthdr;
	int len;

	iph = (struct ipv6hdr *)skb->data;
	iph->payload_len = htons(skb->len - sizeof(*iph));

	nexthdr = *skb->nh.raw;
	*skb->nh.raw = IPPROTO_DSTOPTS;

	dstopt = (struct ipv6_destopt_hdr *)skb->h.raw;
	dstopt->nexthdr = nexthdr;

	hao = mip6_padn((char *)(dstopt + 1),
	calc_padlen(sizeof(*dstopt), 6));

	hao->type = IPV6_TLV_HAO;
	hao->length = sizeof(*hao) - 2;
	BUG_TRAP(hao->length == 16);

	len = ((char )hao - (char )dstopt) + sizeof(*hao);

	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));

	BUG_TRAP(len == x->props.header_len);
	dstopt->hdrlen = (x->props.header_len >> 3) - 1;

	return 0;
	}

	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	u8 **nexthdr)
	{
	u16 offset = sizeof(struct ipv6hdr);
	struct ipv6_opt_hdr exthdr = (struct ipv6_opt_hdr)(skb->nh.ipv6h + 1);
	unsigned int packet_len = skb->tail - skb->nh.raw;
	int found_rhdr = 0;

	*nexthdr = &skb->nh.ipv6h->nexthdr;

	while (offset + 1 <= packet_len) {

	switch (**nexthdr) {
	case NEXTHDR_HOP:
	break;
	case NEXTHDR_ROUTING:
	found_rhdr = 1;
	break;
	case NEXTHDR_DEST:
	/*
	* HAO MUST NOT appear more than once.
	* XXX: It is better to try to find by the end of
	* XXX: packet if HAO exists.
	*/
	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	return offset;
	}

	if (found_rhdr)
	return offset;

	break;
	default:
	return offset;
	}

	offset += ipv6_optlen(exthdr);
	*nexthdr = &exthdr->nexthdr;
	exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
	}

	return offset;
	}

	static int mip6_destopt_init_state(struct xfrm_state *x)
	{
	if (x->id.spi) {
	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	x->id.spi);
	return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	return -EINVAL;
	}

	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	sizeof(struct ipv6_destopt_hao);
	BUG_TRAP(x->props.header_len == 24);

	return 0;
	}

	/*
	* Do nothing about destroying since it has no specific operation for
	* destination options header unlike IPsec protocols.
	*/
	static void mip6_destopt_destroy(struct xfrm_state *x)
	{
	}

	static struct xfrm_type mip6_destopt_type =
	{
	.description = "MIP6DESTOPT",
	.owner = THIS_MODULE,
	.proto = IPPROTO_DSTOPTS,
	.flags = XFRM_TYPE_NON_FRAGMENT,
	.init_state = mip6_destopt_init_state,
	.destructor = mip6_destopt_destroy,
	.input = mip6_destopt_input,
	.output = mip6_destopt_output,
	.hdr_offset = mip6_destopt_offset,
	.local_addr = mip6_xfrm_addr,
	};

	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
	{
	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;

	if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	return -ENOENT;

	return rt2->rt_hdr.nexthdr;
	}

	/* Routing Header type 2 is inserted.
	* IP Header's dst address is replaced with Routing Header's Home Address.
	*/
	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	{
	struct ipv6hdr *iph;
	struct rt2_hdr *rt2;
	u8 nexthdr;

	iph = (struct ipv6hdr *)skb->data;
	iph->payload_len = htons(skb->len - sizeof(*iph));

	nexthdr = *skb->nh.raw;
	*skb->nh.raw = IPPROTO_ROUTING;

	rt2 = (struct rt2_hdr *)skb->h.raw;
	rt2->rt_hdr.nexthdr = nexthdr;
	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	rt2->rt_hdr.segments_left = 1;
	memset(&rt2->reserved, 0, sizeof(rt2->reserved));

	BUG_TRAP(rt2->rt_hdr.hdrlen == 2);

	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));

	return 0;
	}

	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	u8 **nexthdr)
	{
	u16 offset = sizeof(struct ipv6hdr);
	struct ipv6_opt_hdr exthdr = (struct ipv6_opt_hdr)(skb->nh.ipv6h + 1);
	unsigned int packet_len = skb->tail - skb->nh.raw;
	int found_rhdr = 0;

	*nexthdr = &skb->nh.ipv6h->nexthdr;

	while (offset + 1 <= packet_len) {

	switch (**nexthdr) {
	case NEXTHDR_HOP:
	break;
	case NEXTHDR_ROUTING:
	if (offset + 3 <= packet_len) {
	struct ipv6_rt_hdr *rt;
	rt = (struct ipv6_rt_hdr *)(skb->nh.raw + offset);
	if (rt->type != 0)
	return offset;
	}
	found_rhdr = 1;
	break;
	case NEXTHDR_DEST:
	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	return offset;

	if (found_rhdr)
	return offset;

	break;
	default:
	return offset;
	}

	offset += ipv6_optlen(exthdr);
	*nexthdr = &exthdr->nexthdr;
	exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
	}

	return offset;
	}

	static int mip6_rthdr_init_state(struct xfrm_state *x)
	{
	if (x->id.spi) {
	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	x->id.spi);
	return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	return -EINVAL;
	}

	x->props.header_len = sizeof(struct rt2_hdr);

	return 0;
	}

	/*
	* Do nothing about destroying since it has no specific operation for routing
	* header type 2 unlike IPsec protocols.
	*/
	static void mip6_rthdr_destroy(struct xfrm_state *x)
	{
	}

	static struct xfrm_type mip6_rthdr_type =
	{
	.description = "MIP6RT",
	.owner = THIS_MODULE,
	.proto = IPPROTO_ROUTING,
	.flags = XFRM_TYPE_NON_FRAGMENT,
	.init_state = mip6_rthdr_init_state,
	.destructor = mip6_rthdr_destroy,
	.input = mip6_rthdr_input,
	.output = mip6_rthdr_output,
	.hdr_offset = mip6_rthdr_offset,
	.remote_addr = mip6_xfrm_addr,
	};

	int __init mip6_init(void)
	{
	printk(KERN_INFO "Mobile IPv6\n");

	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
	printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
	goto mip6_destopt_xfrm_fail;
	}
	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
	printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
	goto mip6_rthdr_xfrm_fail;
	}
	return 0;

	mip6_rthdr_xfrm_fail:
	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
	mip6_destopt_xfrm_fail:
	return -EAGAIN;
	}

	void __exit mip6_fini(void)
	{
	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
	printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
	printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
	}