[net-next-2.6.git] / net / ipv6 / mip6.c

/*
 * 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/module.h>
#include <linux/skbuff.h>
#include <linux/time.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ip6_checksum.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 inline void mip6_param_prob(struct sk_buff *skb, int code, int pos)
{
	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
}

static int mip6_mh_len(int type)
{
	int len = 0;

	switch (type) {
	case IP6_MH_TYPE_BRR:
		len = 0;
		break;
	case IP6_MH_TYPE_HOTI:
	case IP6_MH_TYPE_COTI:
	case IP6_MH_TYPE_BU:
	case IP6_MH_TYPE_BACK:
		len = 1;
		break;
	case IP6_MH_TYPE_HOT:
	case IP6_MH_TYPE_COT:
	case IP6_MH_TYPE_BERROR:
		len = 2;
		break;
	}
	return len;
}

int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
{
	struct ip6_mh *mh;

	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
				 ((skb_transport_header(skb)[1] + 1) << 3))))
		return -1;

	mh = (struct ip6_mh *)skb_transport_header(skb);

	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
			       mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
		mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
					 skb_network_header(skb)));
		return -1;
	}

	if (mh->ip6mh_proto != IPPROTO_NONE) {
		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
			       mh->ip6mh_proto);
		mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
					 skb_network_header(skb)));
		return -1;
	}

	return 0;
}

struct mip6_report_rate_limiter {
	spinlock_t lock;
	struct timeval stamp;
	int iif;
	struct in6_addr src;
	struct in6_addr dst;
};

static struct mip6_report_rate_limiter mip6_report_rl = {
	.lock = SPIN_LOCK_UNLOCKED
};

static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *iph = ipv6_hdr(skb);
	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_network_header(skb);
	*skb_network_header(skb) = IPPROTO_DSTOPTS;

	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
	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 inline int mip6_report_rl_allow(struct timeval *stamp,
				       struct in6_addr *dst,
				       struct in6_addr *src, int iif)
{
	int allow = 0;

	spin_lock_bh(&mip6_report_rl.lock);
	if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
	    mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
	    mip6_report_rl.iif != iif ||
	    !ipv6_addr_equal(&mip6_report_rl.src, src) ||
	    !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
		mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
		mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
		mip6_report_rl.iif = iif;
		ipv6_addr_copy(&mip6_report_rl.src, src);
		ipv6_addr_copy(&mip6_report_rl.dst, dst);
		allow = 1;
	}
	spin_unlock_bh(&mip6_report_rl.lock);
	return allow;
}

static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl)
{
	struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
	struct ipv6_destopt_hao *hao = NULL;
	struct xfrm_selector sel;
	int offset;
	struct timeval stamp;
	int err = 0;

	if (unlikely(fl->proto == IPPROTO_MH &&
		     fl->fl_mh_type <= IP6_MH_TYPE_MAX))
		goto out;

	if (likely(opt->dsthao)) {
		offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
		if (likely(offset >= 0))
			hao = (struct ipv6_destopt_hao *)
					(skb_network_header(skb) + offset);
	}

	skb_get_timestamp(skb, &stamp);

	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
				  hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
				  opt->iif))
		goto out;

	memset(&sel, 0, sizeof(sel));
	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
	       sizeof(sel.daddr));
	sel.prefixlen_d = 128;
	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
	       sizeof(sel.saddr));
	sel.prefixlen_s = 128;
	sel.family = AF_INET6;
	sel.proto = fl->proto;
	sel.dport = xfrm_flowi_dport(fl);
	if (sel.dport)
		sel.dport_mask = htons(~0);
	sel.sport = xfrm_flowi_sport(fl);
	if (sel.sport)
		sel.sport_mask = htons(~0);
	sel.ifindex = fl->oif;

	err = km_report(IPPROTO_DSTOPTS, &sel,
			(hao ? (xfrm_address_t *)&hao->addr : NULL));

 out:
	return err;
}

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 *)(ipv6_hdr(skb) + 1);
	const unsigned char *nh = skb_network_header(skb);
	unsigned int packet_len = skb->tail - nh;
	int found_rhdr = 0;

	*nexthdr = &ipv6_hdr(skb)->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 *)(nh + 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,
	.reject		= mip6_destopt_reject,
	.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_network_header(skb);
	*skb_network_header(skb) = IPPROTO_ROUTING;

	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
	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 *)(ipv6_hdr(skb) + 1);
	const unsigned char *nh = skb_network_header(skb);
	unsigned int packet_len = skb->tail - nh;
	int found_rhdr = 0;

	*nexthdr = &ipv6_hdr(skb)->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 *)(nh + 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 *)(nh + 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__);
}
Commit	Line	Data
2c8d7ca0 NT	1	/*
	2	* Copyright (C)2003-2006 Helsinki University of Technology
	3	* Copyright (C)2003-2006 USAGI/WIDE Project
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19	/*
	20	* Authors:
	21	* Noriaki TAKAMIYA @USAGI
	22	* Masahide NAKAMURA @USAGI
	23	*/
	24
2c8d7ca0 NT	25	#include <linux/module.h>
2c8d7ca0 NT	26	#include <linux/skbuff.h>
70182ed2	27	#include <linux/time.h>
2c8d7ca0	28	#include <linux/ipv6.h>
7be96f76 MN	29	#include <linux/icmpv6.h>
7be96f76 MN	30	#include <net/sock.h>
2c8d7ca0	31	#include <net/ipv6.h>
7be96f76	32	#include <net/ip6_checksum.h>
2c8d7ca0 NT	33	#include <net/xfrm.h>
	34	#include <net/mip6.h>
	35
	36	static xfrm_address_t mip6_xfrm_addr(struct xfrm_state x, xfrm_address_t *addr)
	37	{
	38	return x->coaddr;
	39	}
	40
3d126890 NT	41	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	42	{
	43	return (n - len + 16) & 0x7;
	44	}
	45
	46	static inline void mip6_padn(__u8 data, __u8 padlen)
	47	{
	48	if (!data)
	49	return NULL;
	50	if (padlen == 1) {
	51	data[0] = MIP6_OPT_PAD_1;
	52	} else if (padlen > 1) {
	53	data[0] = MIP6_OPT_PAD_N;
	54	data[1] = padlen - 2;
	55	if (padlen > 2)
	56	memset(data+2, 0, data[1]);
	57	}
	58	return data + padlen;
	59	}
	60
7be96f76 MN	61	static inline void mip6_param_prob(struct sk_buff *skb, int code, int pos)
	62	{
	63	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
	64	}
	65
	66	static int mip6_mh_len(int type)
	67	{
	68	int len = 0;
	69
	70	switch (type) {
	71	case IP6_MH_TYPE_BRR:
	72	len = 0;
	73	break;
	74	case IP6_MH_TYPE_HOTI:
	75	case IP6_MH_TYPE_COTI:
	76	case IP6_MH_TYPE_BU:
	77	case IP6_MH_TYPE_BACK:
	78	len = 1;
	79	break;
	80	case IP6_MH_TYPE_HOT:
	81	case IP6_MH_TYPE_COT:
	82	case IP6_MH_TYPE_BERROR:
	83	len = 2;
	84	break;
	85	}
	86	return len;
	87	}
	88
	89	int mip6_mh_filter(struct sock sk, struct sk_buff skb)
	90	{
	91	struct ip6_mh *mh;
7be96f76	92
ea2ae17d ACM	93	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) \|\|
ea2ae17d ACM	94	!pskb_may_pull(skb, (skb_transport_offset(skb) +
9c70220b	95	((skb_transport_header(skb)[1] + 1) << 3))))
7be96f76 MN	96	return -1;
7be96f76 MN	97
9c70220b	98	mh = (struct ip6_mh *)skb_transport_header(skb);
7be96f76 MN	99
	100	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
	101	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
	102	mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
d56f90a7 ACM	103	mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
d56f90a7 ACM	104	skb_network_header(skb)));
7be96f76 MN	105	return -1;
7be96f76 MN	106	}
7be96f76 MN	107
	108	if (mh->ip6mh_proto != IPPROTO_NONE) {
	109	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
	110	mh->ip6mh_proto);
d56f90a7 ACM	111	mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
d56f90a7 ACM	112	skb_network_header(skb)));
7be96f76 MN	113	return -1;
	114	}
	115
	116	return 0;
	117	}
	118
70182ed2 MN	119	struct mip6_report_rate_limiter {
	120	spinlock_t lock;
	121	struct timeval stamp;
	122	int iif;
	123	struct in6_addr src;
	124	struct in6_addr dst;
	125	};
	126
	127	static struct mip6_report_rate_limiter mip6_report_rl = {
	128	.lock = SPIN_LOCK_UNLOCKED
	129	};
	130
3d126890 NT	131	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	132	{
0660e03f	133	struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890 NT	134	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
	135
	136	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	137	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	138	return -ENOENT;
	139
	140	return destopt->nexthdr;
	141	}
	142
	143	/* Destination Option Header is inserted.
	144	* IP Header's src address is replaced with Home Address Option in
	145	* Destination Option Header.
	146	*/
	147	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	148	{
	149	struct ipv6hdr *iph;
	150	struct ipv6_destopt_hdr *dstopt;
	151	struct ipv6_destopt_hao *hao;
	152	u8 nexthdr;
	153	int len;
	154
	155	iph = (struct ipv6hdr *)skb->data;
	156	iph->payload_len = htons(skb->len - sizeof(*iph));
	157
d56f90a7 ACM	158	nexthdr = *skb_network_header(skb);
d56f90a7 ACM	159	*skb_network_header(skb) = IPPROTO_DSTOPTS;
3d126890	160
9c70220b	161	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
3d126890 NT	162	dstopt->nexthdr = nexthdr;
	163
	164	hao = mip6_padn((char *)(dstopt + 1),
	165	calc_padlen(sizeof(*dstopt), 6));
	166
	167	hao->type = IPV6_TLV_HAO;
	168	hao->length = sizeof(*hao) - 2;
	169	BUG_TRAP(hao->length == 16);
	170
	171	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	172
	173	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
	174	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
	175
	176	BUG_TRAP(len == x->props.header_len);
	177	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	178
	179	return 0;
	180	}
	181
70182ed2 MN	182	static inline int mip6_report_rl_allow(struct timeval *stamp,
	183	struct in6_addr *dst,
	184	struct in6_addr *src, int iif)
	185	{
	186	int allow = 0;
	187
	188	spin_lock_bh(&mip6_report_rl.lock);
	189	if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec \|\|
	190	mip6_report_rl.stamp.tv_usec != stamp->tv_usec \|\|
	191	mip6_report_rl.iif != iif \|\|
	192	!ipv6_addr_equal(&mip6_report_rl.src, src) \|\|
	193	!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
	194	mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
	195	mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
	196	mip6_report_rl.iif = iif;
	197	ipv6_addr_copy(&mip6_report_rl.src, src);
	198	ipv6_addr_copy(&mip6_report_rl.dst, dst);
	199	allow = 1;
	200	}
	201	spin_unlock_bh(&mip6_report_rl.lock);
	202	return allow;
	203	}
	204
	205	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb, struct flowi *fl)
	206	{
	207	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
	208	struct ipv6_destopt_hao *hao = NULL;
	209	struct xfrm_selector sel;
	210	int offset;
	211	struct timeval stamp;
	212	int err = 0;
	213
e731c248 YH	214	if (unlikely(fl->proto == IPPROTO_MH &&
e731c248 YH	215	fl->fl_mh_type <= IP6_MH_TYPE_MAX))
01be8e5d MN	216	goto out;
01be8e5d MN	217
70182ed2 MN	218	if (likely(opt->dsthao)) {
	219	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	220	if (likely(offset >= 0))
d56f90a7 ACM	221	hao = (struct ipv6_destopt_hao *)
d56f90a7 ACM	222	(skb_network_header(skb) + offset);
70182ed2 MN	223	}
	224
	225	skb_get_timestamp(skb, &stamp);
	226
0660e03f ACM	227	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
0660e03f ACM	228	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
70182ed2 MN	229	opt->iif))
	230	goto out;
	231
	232	memset(&sel, 0, sizeof(sel));
0660e03f	233	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
70182ed2 MN	234	sizeof(sel.daddr));
70182ed2 MN	235	sel.prefixlen_d = 128;
0660e03f	236	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
70182ed2 MN	237	sizeof(sel.saddr));
	238	sel.prefixlen_s = 128;
	239	sel.family = AF_INET6;
	240	sel.proto = fl->proto;
	241	sel.dport = xfrm_flowi_dport(fl);
	242	if (sel.dport)
e69a4adc	243	sel.dport_mask = htons(~0);
70182ed2 MN	244	sel.sport = xfrm_flowi_sport(fl);
70182ed2 MN	245	if (sel.sport)
e69a4adc	246	sel.sport_mask = htons(~0);
70182ed2 MN	247	sel.ifindex = fl->oif;
	248
	249	err = km_report(IPPROTO_DSTOPTS, &sel,
	250	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	251
	252	out:
	253	return err;
	254	}
	255
3d126890 NT	256	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	257	u8 **nexthdr)
	258	{
	259	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	260	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	261	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7 ACM	262	const unsigned char *nh = skb_network_header(skb);
d56f90a7 ACM	263	unsigned int packet_len = skb->tail - nh;
3d126890 NT	264	int found_rhdr = 0;
3d126890 NT	265
0660e03f	266	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	267
	268	while (offset + 1 <= packet_len) {
	269
	270	switch (**nexthdr) {
	271	case NEXTHDR_HOP:
	272	break;
	273	case NEXTHDR_ROUTING:
	274	found_rhdr = 1;
	275	break;
	276	case NEXTHDR_DEST:
	277	/*
	278	* HAO MUST NOT appear more than once.
	279	* XXX: It is better to try to find by the end of
	280	* XXX: packet if HAO exists.
	281	*/
	282	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	283	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	284	return offset;
	285	}
	286
	287	if (found_rhdr)
	288	return offset;
	289
	290	break;
	291	default:
	292	return offset;
	293	}
	294
	295	offset += ipv6_optlen(exthdr);
	296	*nexthdr = &exthdr->nexthdr;
d56f90a7	297	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	298	}
	299
	300	return offset;
	301	}
	302
	303	static int mip6_destopt_init_state(struct xfrm_state *x)
	304	{
	305	if (x->id.spi) {
	306	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	307	x->id.spi);
	308	return -EINVAL;
	309	}
	310	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	311	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	312	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	313	return -EINVAL;
	314	}
	315
	316	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	317	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	318	sizeof(struct ipv6_destopt_hao);
	319	BUG_TRAP(x->props.header_len == 24);
	320
	321	return 0;
	322	}
	323
	324	/*
	325	* Do nothing about destroying since it has no specific operation for
	326	* destination options header unlike IPsec protocols.
	327	*/
	328	static void mip6_destopt_destroy(struct xfrm_state *x)
	329	{
	330	}
	331
	332	static struct xfrm_type mip6_destopt_type =
	333	{
	334	.description = "MIP6DESTOPT",
	335	.owner = THIS_MODULE,
	336	.proto = IPPROTO_DSTOPTS,
	337	.flags = XFRM_TYPE_NON_FRAGMENT,
	338	.init_state = mip6_destopt_init_state,
	339	.destructor = mip6_destopt_destroy,
	340	.input = mip6_destopt_input,
	341	.output = mip6_destopt_output,
1ab1457c	342	.reject = mip6_destopt_reject,
3d126890 NT	343	.hdr_offset = mip6_destopt_offset,
	344	.local_addr = mip6_xfrm_addr,
	345	};
	346
2c8d7ca0 NT	347	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
	348	{
	349	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
	350
	351	if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
	352	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	353	return -ENOENT;
	354
	355	return rt2->rt_hdr.nexthdr;
	356	}
	357
	358	/* Routing Header type 2 is inserted.
	359	* IP Header's dst address is replaced with Routing Header's Home Address.
	360	*/
	361	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	362	{
	363	struct ipv6hdr *iph;
	364	struct rt2_hdr *rt2;
	365	u8 nexthdr;
	366
	367	iph = (struct ipv6hdr *)skb->data;
	368	iph->payload_len = htons(skb->len - sizeof(*iph));
	369
d56f90a7 ACM	370	nexthdr = *skb_network_header(skb);
d56f90a7 ACM	371	*skb_network_header(skb) = IPPROTO_ROUTING;
2c8d7ca0	372
9c70220b	373	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
2c8d7ca0 NT	374	rt2->rt_hdr.nexthdr = nexthdr;
	375	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	376	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	377	rt2->rt_hdr.segments_left = 1;
	378	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	379
	380	BUG_TRAP(rt2->rt_hdr.hdrlen == 2);
	381
	382	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
	383	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
	384
	385	return 0;
	386	}
	387
	388	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	389	u8 **nexthdr)
	390	{
	391	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	392	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	393	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7 ACM	394	const unsigned char *nh = skb_network_header(skb);
d56f90a7 ACM	395	unsigned int packet_len = skb->tail - nh;
2c8d7ca0 NT	396	int found_rhdr = 0;
2c8d7ca0 NT	397
0660e03f	398	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	399
	400	while (offset + 1 <= packet_len) {
	401
	402	switch (**nexthdr) {
	403	case NEXTHDR_HOP:
	404	break;
	405	case NEXTHDR_ROUTING:
	406	if (offset + 3 <= packet_len) {
	407	struct ipv6_rt_hdr *rt;
d56f90a7	408	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	409	if (rt->type != 0)
	410	return offset;
	411	}
	412	found_rhdr = 1;
	413	break;
	414	case NEXTHDR_DEST:
	415	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	416	return offset;
	417
	418	if (found_rhdr)
	419	return offset;
	420
	421	break;
	422	default:
	423	return offset;
	424	}
	425
	426	offset += ipv6_optlen(exthdr);
	427	*nexthdr = &exthdr->nexthdr;
d56f90a7	428	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	429	}
	430
	431	return offset;
	432	}
	433
	434	static int mip6_rthdr_init_state(struct xfrm_state *x)
	435	{
	436	if (x->id.spi) {
	437	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	438	x->id.spi);
	439	return -EINVAL;
	440	}
	441	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	442	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	443	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	444	return -EINVAL;
	445	}
	446
	447	x->props.header_len = sizeof(struct rt2_hdr);
	448
	449	return 0;
	450	}
	451
	452	/*
	453	* Do nothing about destroying since it has no specific operation for routing
	454	* header type 2 unlike IPsec protocols.
	455	*/
	456	static void mip6_rthdr_destroy(struct xfrm_state *x)
	457	{
	458	}
	459
	460	static struct xfrm_type mip6_rthdr_type =
	461	{
	462	.description = "MIP6RT",
	463	.owner = THIS_MODULE,
	464	.proto = IPPROTO_ROUTING,
	465	.flags = XFRM_TYPE_NON_FRAGMENT,
	466	.init_state = mip6_rthdr_init_state,
	467	.destructor = mip6_rthdr_destroy,
	468	.input = mip6_rthdr_input,
	469	.output = mip6_rthdr_output,
	470	.hdr_offset = mip6_rthdr_offset,
	471	.remote_addr = mip6_xfrm_addr,
	472	};
	473
	474	int __init mip6_init(void)
	475	{
	476	printk(KERN_INFO "Mobile IPv6\n");
	477
3d126890 NT	478	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
	479	printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
	480	goto mip6_destopt_xfrm_fail;
	481	}
2c8d7ca0 NT	482	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
	483	printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
	484	goto mip6_rthdr_xfrm_fail;
	485	}
	486	return 0;
	487
	488	mip6_rthdr_xfrm_fail:
3d126890 NT	489	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
3d126890 NT	490	mip6_destopt_xfrm_fail:
2c8d7ca0 NT	491	return -EAGAIN;
	492	}
	493
	494	void __exit mip6_fini(void)
	495	{
	496	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
	497	printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
3d126890 NT	498	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
3d126890 NT	499	printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
2c8d7ca0	500	}