[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/rawv6.h>
#include <net/xfrm.h>
#include <net/mip6.h>

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] = IPV6_TLV_PAD0;
	} else if (padlen > 1) {
		data[0] = IPV6_TLV_PADN;
		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, u8 code, int pos)
{
	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
}

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;
}

static 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(mip6_report_rl.lock)
};

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;
	int err = destopt->nexthdr;

	spin_lock(&x->lock);
	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
		err = -ENOENT;
	spin_unlock(&x->lock);

	return err;
}

/* 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;

	skb_push(skb, -skb_network_offset(skb));
	iph = ipv6_hdr(skb);

	nexthdr = *skb_mac_header(skb);
	*skb_mac_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;
	BUILD_BUG_ON(sizeof(*hao) != 18);
	hao->length = sizeof(*hao) - 2;

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

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

	WARN_ON(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 net *net = xs_net(x);
	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(net, 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 - skb->network_header;
	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", __func__,
		       x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
		       __func__, 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);
	WARN_ON(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 const struct xfrm_type mip6_destopt_type =
{
	.description	= "MIP6DESTOPT",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_DSTOPTS,
	.flags		= XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
	.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,
};

static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *iph = ipv6_hdr(skb);
	struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
	int err = rt2->rt_hdr.nexthdr;

	spin_lock(&x->lock);
	if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
		err = -ENOENT;
	spin_unlock(&x->lock);

	return err;
}

/* 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;

	skb_push(skb, -skb_network_offset(skb));
	iph = ipv6_hdr(skb);

	nexthdr = *skb_mac_header(skb);
	*skb_mac_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));

	WARN_ON(rt2->rt_hdr.hdrlen != 2);

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

	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 - skb->network_header;
	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", __func__,
		       x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
		       __func__, 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 const struct xfrm_type mip6_rthdr_type =
{
	.description	= "MIP6RT",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_ROUTING,
	.flags		= XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
	.init_state	= mip6_rthdr_init_state,
	.destructor	= mip6_rthdr_destroy,
	.input		= mip6_rthdr_input,
	.output		= mip6_rthdr_output,
	.hdr_offset	= mip6_rthdr_offset,
};

static 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", __func__);
		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", __func__);
		goto mip6_rthdr_xfrm_fail;
	}
	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
		printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __func__);
		goto mip6_rawv6_mh_fail;
	}


	return 0;

 mip6_rawv6_mh_fail:
	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
 mip6_rthdr_xfrm_fail:
	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
 mip6_destopt_xfrm_fail:
	return -EAGAIN;
}

static void __exit mip6_fini(void)
{
	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
		printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
		printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
		printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
}

module_init(mip6_init);
module_exit(mip6_fini);

MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
Commit	Line	Data
	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
	25	#include <linux/module.h>
	26	#include <linux/skbuff.h>
	27	#include <linux/time.h>
	28	#include <linux/ipv6.h>
	29	#include <linux/icmpv6.h>
	30	#include <net/sock.h>
	31	#include <net/ipv6.h>
	32	#include <net/ip6_checksum.h>
	33	#include <net/rawv6.h>
	34	#include <net/xfrm.h>
	35	#include <net/mip6.h>
	36
	37	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	38	{
	39	return (n - len + 16) & 0x7;
	40	}
	41
	42	static inline void mip6_padn(__u8 data, __u8 padlen)
	43	{
	44	if (!data)
	45	return NULL;
	46	if (padlen == 1) {
	47	data[0] = IPV6_TLV_PAD0;
	48	} else if (padlen > 1) {
	49	data[0] = IPV6_TLV_PADN;
	50	data[1] = padlen - 2;
	51	if (padlen > 2)
	52	memset(data+2, 0, data[1]);
	53	}
	54	return data + padlen;
	55	}
	56
	57	static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
	58	{
	59	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
	60	}
	61
	62	static int mip6_mh_len(int type)
	63	{
	64	int len = 0;
	65
	66	switch (type) {
	67	case IP6_MH_TYPE_BRR:
	68	len = 0;
	69	break;
	70	case IP6_MH_TYPE_HOTI:
	71	case IP6_MH_TYPE_COTI:
	72	case IP6_MH_TYPE_BU:
	73	case IP6_MH_TYPE_BACK:
	74	len = 1;
	75	break;
	76	case IP6_MH_TYPE_HOT:
	77	case IP6_MH_TYPE_COT:
	78	case IP6_MH_TYPE_BERROR:
	79	len = 2;
	80	break;
	81	}
	82	return len;
	83	}
	84
	85	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
	86	{
	87	struct ip6_mh *mh;
	88
	89	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) \|\|
	90	!pskb_may_pull(skb, (skb_transport_offset(skb) +
	91	((skb_transport_header(skb)[1] + 1) << 3))))
	92	return -1;
	93
	94	mh = (struct ip6_mh *)skb_transport_header(skb);
	95
	96	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
	97	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
	98	mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
	99	mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
	100	skb_network_header(skb)));
	101	return -1;
	102	}
	103
	104	if (mh->ip6mh_proto != IPPROTO_NONE) {
	105	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
	106	mh->ip6mh_proto);
	107	mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
	108	skb_network_header(skb)));
	109	return -1;
	110	}
	111
	112	return 0;
	113	}
	114
	115	struct mip6_report_rate_limiter {
	116	spinlock_t lock;
	117	struct timeval stamp;
	118	int iif;
	119	struct in6_addr src;
	120	struct in6_addr dst;
	121	};
	122
	123	static struct mip6_report_rate_limiter mip6_report_rl = {
	124	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
	125	};
	126
	127	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
	128	{
	129	struct ipv6hdr *iph = ipv6_hdr(skb);
	130	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
	131	int err = destopt->nexthdr;
	132
	133	spin_lock(&x->lock);
	134	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	135	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	136	err = -ENOENT;
	137	spin_unlock(&x->lock);
	138
	139	return err;
	140	}
	141
	142	/* Destination Option Header is inserted.
	143	* IP Header's src address is replaced with Home Address Option in
	144	* Destination Option Header.
	145	*/
	146	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	147	{
	148	struct ipv6hdr *iph;
	149	struct ipv6_destopt_hdr *dstopt;
	150	struct ipv6_destopt_hao *hao;
	151	u8 nexthdr;
	152	int len;
	153
	154	skb_push(skb, -skb_network_offset(skb));
	155	iph = ipv6_hdr(skb);
	156
	157	nexthdr = *skb_mac_header(skb);
	158	*skb_mac_header(skb) = IPPROTO_DSTOPTS;
	159
	160	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
	161	dstopt->nexthdr = nexthdr;
	162
	163	hao = mip6_padn((char *)(dstopt + 1),
	164	calc_padlen(sizeof(*dstopt), 6));
	165
	166	hao->type = IPV6_TLV_HAO;
	167	BUILD_BUG_ON(sizeof(*hao) != 18);
	168	hao->length = sizeof(*hao) - 2;
	169
	170	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	171
	172	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
	173	spin_lock_bh(&x->lock);
	174	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
	175	spin_unlock_bh(&x->lock);
	176
	177	WARN_ON(len != x->props.header_len);
	178	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	179
	180	return 0;
	181	}
	182
	183	static inline int mip6_report_rl_allow(struct timeval *stamp,
	184	struct in6_addr *dst,
	185	struct in6_addr *src, int iif)
	186	{
	187	int allow = 0;
	188
	189	spin_lock_bh(&mip6_report_rl.lock);
	190	if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec \|\|
	191	mip6_report_rl.stamp.tv_usec != stamp->tv_usec \|\|
	192	mip6_report_rl.iif != iif \|\|
	193	!ipv6_addr_equal(&mip6_report_rl.src, src) \|\|
	194	!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
	195	mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
	196	mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
	197	mip6_report_rl.iif = iif;
	198	ipv6_addr_copy(&mip6_report_rl.src, src);
	199	ipv6_addr_copy(&mip6_report_rl.dst, dst);
	200	allow = 1;
	201	}
	202	spin_unlock_bh(&mip6_report_rl.lock);
	203	return allow;
	204	}
	205
	206	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb, struct flowi *fl)
	207	{
	208	struct net *net = xs_net(x);
	209	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
	210	struct ipv6_destopt_hao *hao = NULL;
	211	struct xfrm_selector sel;
	212	int offset;
	213	struct timeval stamp;
	214	int err = 0;
	215
	216	if (unlikely(fl->proto == IPPROTO_MH &&
	217	fl->fl_mh_type <= IP6_MH_TYPE_MAX))
	218	goto out;
	219
	220	if (likely(opt->dsthao)) {
	221	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	222	if (likely(offset >= 0))
	223	hao = (struct ipv6_destopt_hao *)
	224	(skb_network_header(skb) + offset);
	225	}
	226
	227	skb_get_timestamp(skb, &stamp);
	228
	229	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
	230	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
	231	opt->iif))
	232	goto out;
	233
	234	memset(&sel, 0, sizeof(sel));
	235	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
	236	sizeof(sel.daddr));
	237	sel.prefixlen_d = 128;
	238	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
	239	sizeof(sel.saddr));
	240	sel.prefixlen_s = 128;
	241	sel.family = AF_INET6;
	242	sel.proto = fl->proto;
	243	sel.dport = xfrm_flowi_dport(fl);
	244	if (sel.dport)
	245	sel.dport_mask = htons(~0);
	246	sel.sport = xfrm_flowi_sport(fl);
	247	if (sel.sport)
	248	sel.sport_mask = htons(~0);
	249	sel.ifindex = fl->oif;
	250
	251	err = km_report(net, IPPROTO_DSTOPTS, &sel,
	252	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	253
	254	out:
	255	return err;
	256	}
	257
	258	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	259	u8 **nexthdr)
	260	{
	261	u16 offset = sizeof(struct ipv6hdr);
	262	struct ipv6_opt_hdr *exthdr =
	263	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
	264	const unsigned char *nh = skb_network_header(skb);
	265	unsigned int packet_len = skb->tail - skb->network_header;
	266	int found_rhdr = 0;
	267
	268	*nexthdr = &ipv6_hdr(skb)->nexthdr;
	269
	270	while (offset + 1 <= packet_len) {
	271
	272	switch (**nexthdr) {
	273	case NEXTHDR_HOP:
	274	break;
	275	case NEXTHDR_ROUTING:
	276	found_rhdr = 1;
	277	break;
	278	case NEXTHDR_DEST:
	279	/*
	280	* HAO MUST NOT appear more than once.
	281	* XXX: It is better to try to find by the end of
	282	* XXX: packet if HAO exists.
	283	*/
	284	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	285	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	286	return offset;
	287	}
	288
	289	if (found_rhdr)
	290	return offset;
	291
	292	break;
	293	default:
	294	return offset;
	295	}
	296
	297	offset += ipv6_optlen(exthdr);
	298	*nexthdr = &exthdr->nexthdr;
	299	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
	300	}
	301
	302	return offset;
	303	}
	304
	305	static int mip6_destopt_init_state(struct xfrm_state *x)
	306	{
	307	if (x->id.spi) {
	308	printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
	309	x->id.spi);
	310	return -EINVAL;
	311	}
	312	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	313	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	314	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	315	return -EINVAL;
	316	}
	317
	318	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	319	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	320	sizeof(struct ipv6_destopt_hao);
	321	WARN_ON(x->props.header_len != 24);
	322
	323	return 0;
	324	}
	325
	326	/*
	327	* Do nothing about destroying since it has no specific operation for
	328	* destination options header unlike IPsec protocols.
	329	*/
	330	static void mip6_destopt_destroy(struct xfrm_state *x)
	331	{
	332	}
	333
	334	static const struct xfrm_type mip6_destopt_type =
	335	{
	336	.description = "MIP6DESTOPT",
	337	.owner = THIS_MODULE,
	338	.proto = IPPROTO_DSTOPTS,
	339	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_LOCAL_COADDR,
	340	.init_state = mip6_destopt_init_state,
	341	.destructor = mip6_destopt_destroy,
	342	.input = mip6_destopt_input,
	343	.output = mip6_destopt_output,
	344	.reject = mip6_destopt_reject,
	345	.hdr_offset = mip6_destopt_offset,
	346	};
	347
	348	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
	349	{
	350	struct ipv6hdr *iph = ipv6_hdr(skb);
	351	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
	352	int err = rt2->rt_hdr.nexthdr;
	353
	354	spin_lock(&x->lock);
	355	if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
	356	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	357	err = -ENOENT;
	358	spin_unlock(&x->lock);
	359
	360	return err;
	361	}
	362
	363	/* Routing Header type 2 is inserted.
	364	* IP Header's dst address is replaced with Routing Header's Home Address.
	365	*/
	366	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	367	{
	368	struct ipv6hdr *iph;
	369	struct rt2_hdr *rt2;
	370	u8 nexthdr;
	371
	372	skb_push(skb, -skb_network_offset(skb));
	373	iph = ipv6_hdr(skb);
	374
	375	nexthdr = *skb_mac_header(skb);
	376	*skb_mac_header(skb) = IPPROTO_ROUTING;
	377
	378	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
	379	rt2->rt_hdr.nexthdr = nexthdr;
	380	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	381	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	382	rt2->rt_hdr.segments_left = 1;
	383	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	384
	385	WARN_ON(rt2->rt_hdr.hdrlen != 2);
	386
	387	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
	388	spin_lock_bh(&x->lock);
	389	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
	390	spin_unlock_bh(&x->lock);
	391
	392	return 0;
	393	}
	394
	395	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	396	u8 **nexthdr)
	397	{
	398	u16 offset = sizeof(struct ipv6hdr);
	399	struct ipv6_opt_hdr *exthdr =
	400	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
	401	const unsigned char *nh = skb_network_header(skb);
	402	unsigned int packet_len = skb->tail - skb->network_header;
	403	int found_rhdr = 0;
	404
	405	*nexthdr = &ipv6_hdr(skb)->nexthdr;
	406
	407	while (offset + 1 <= packet_len) {
	408
	409	switch (**nexthdr) {
	410	case NEXTHDR_HOP:
	411	break;
	412	case NEXTHDR_ROUTING:
	413	if (offset + 3 <= packet_len) {
	414	struct ipv6_rt_hdr *rt;
	415	rt = (struct ipv6_rt_hdr *)(nh + offset);
	416	if (rt->type != 0)
	417	return offset;
	418	}
	419	found_rhdr = 1;
	420	break;
	421	case NEXTHDR_DEST:
	422	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	423	return offset;
	424
	425	if (found_rhdr)
	426	return offset;
	427
	428	break;
	429	default:
	430	return offset;
	431	}
	432
	433	offset += ipv6_optlen(exthdr);
	434	*nexthdr = &exthdr->nexthdr;
	435	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
	436	}
	437
	438	return offset;
	439	}
	440
	441	static int mip6_rthdr_init_state(struct xfrm_state *x)
	442	{
	443	if (x->id.spi) {
	444	printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
	445	x->id.spi);
	446	return -EINVAL;
	447	}
	448	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	449	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	450	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	451	return -EINVAL;
	452	}
	453
	454	x->props.header_len = sizeof(struct rt2_hdr);
	455
	456	return 0;
	457	}
	458
	459	/*
	460	* Do nothing about destroying since it has no specific operation for routing
	461	* header type 2 unlike IPsec protocols.
	462	*/
	463	static void mip6_rthdr_destroy(struct xfrm_state *x)
	464	{
	465	}
	466
	467	static const struct xfrm_type mip6_rthdr_type =
	468	{
	469	.description = "MIP6RT",
	470	.owner = THIS_MODULE,
	471	.proto = IPPROTO_ROUTING,
	472	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_REMOTE_COADDR,
	473	.init_state = mip6_rthdr_init_state,
	474	.destructor = mip6_rthdr_destroy,
	475	.input = mip6_rthdr_input,
	476	.output = mip6_rthdr_output,
	477	.hdr_offset = mip6_rthdr_offset,
	478	};
	479
	480	static int __init mip6_init(void)
	481	{
	482	printk(KERN_INFO "Mobile IPv6\n");
	483
	484	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
	485	printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __func__);
	486	goto mip6_destopt_xfrm_fail;
	487	}
	488	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
	489	printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __func__);
	490	goto mip6_rthdr_xfrm_fail;
	491	}
	492	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
	493	printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __func__);
	494	goto mip6_rawv6_mh_fail;
	495	}
	496
	497
	498	return 0;
	499
	500	mip6_rawv6_mh_fail:
	501	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
	502	mip6_rthdr_xfrm_fail:
	503	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
	504	mip6_destopt_xfrm_fail:
	505	return -EAGAIN;
	506	}
	507
	508	static void __exit mip6_fini(void)
	509	{
	510	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
	511	printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
	512	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
	513	printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
	514	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
	515	printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
	516	}
	517
	518	module_init(mip6_init);
	519	module_exit(mip6_fini);
	520
	521	MODULE_LICENSE("GPL");
	522	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
	523	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);