[deliverable/linux.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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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_PAD1;
	} 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)
{
	const 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,
				       const struct in6_addr *dst,
				       const 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;
		mip6_report_rl.src = *src;
		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,
			       const struct flowi *fl)
{
	struct net *net = xs_net(x);
	struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
	const struct flowi6 *fl6 = &fl->u.ip6;
	struct ipv6_destopt_hao *hao = NULL;
	struct xfrm_selector sel;
	int offset;
	struct timeval stamp;
	int err = 0;

	if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
		     fl6->fl6_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 = fl6->flowi6_proto;
	sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
	if (sel.dport)
		sel.dport_mask = htons(~0);
	sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
	if (sel.sport)
		sel.sport_mask = htons(~0);
	sel.ifindex = fl6->flowi6_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) {
		pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		pr_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)
{
	const 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) {
		pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		pr_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)
{
	pr_info("Mobile IPv6\n");

	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
		pr_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) {
		pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
		goto mip6_rthdr_xfrm_fail;
	}
	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
		pr_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)
		pr_info("%s: can't remove rawv6 mh filter\n", __func__);
	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
		pr_info("%s: can't remove xfrm type(rthdr)\n", __func__);
	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
		pr_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
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
f3213831 JP	25	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
f3213831 JP	26
2c8d7ca0 NT	27	#include <linux/module.h>
2c8d7ca0 NT	28	#include <linux/skbuff.h>
70182ed2	29	#include <linux/time.h>
2c8d7ca0	30	#include <linux/ipv6.h>
7be96f76 MN	31	#include <linux/icmpv6.h>
7be96f76 MN	32	#include <net/sock.h>
2c8d7ca0	33	#include <net/ipv6.h>
7be96f76	34	#include <net/ip6_checksum.h>
59fbb3a6	35	#include <net/rawv6.h>
2c8d7ca0 NT	36	#include <net/xfrm.h>
	37	#include <net/mip6.h>
	38
3d126890 NT	39	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	40	{
	41	return (n - len + 16) & 0x7;
	42	}
	43
	44	static inline void mip6_padn(__u8 data, __u8 padlen)
	45	{
	46	if (!data)
	47	return NULL;
	48	if (padlen == 1) {
1de5a71c	49	data[0] = IPV6_TLV_PAD1;
3d126890	50	} else if (padlen > 1) {
7f1eced8	51	data[0] = IPV6_TLV_PADN;
3d126890 NT	52	data[1] = padlen - 2;
	53	if (padlen > 2)
	54	memset(data+2, 0, data[1]);
	55	}
	56	return data + padlen;
	57	}
	58
d5fdd6ba	59	static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
7be96f76	60	{
3ffe533c	61	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
7be96f76 MN	62	}
	63
	64	static int mip6_mh_len(int type)
	65	{
	66	int len = 0;
	67
	68	switch (type) {
	69	case IP6_MH_TYPE_BRR:
	70	len = 0;
	71	break;
	72	case IP6_MH_TYPE_HOTI:
	73	case IP6_MH_TYPE_COTI:
	74	case IP6_MH_TYPE_BU:
	75	case IP6_MH_TYPE_BACK:
	76	len = 1;
	77	break;
	78	case IP6_MH_TYPE_HOT:
	79	case IP6_MH_TYPE_COT:
	80	case IP6_MH_TYPE_BERROR:
	81	len = 2;
	82	break;
	83	}
	84	return len;
	85	}
	86
59fbb3a6	87	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
7be96f76 MN	88	{
7be96f76 MN	89	struct ip6_mh *mh;
7be96f76	90
ea2ae17d ACM	91	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) \|\|
ea2ae17d ACM	92	!pskb_may_pull(skb, (skb_transport_offset(skb) +
9c70220b	93	((skb_transport_header(skb)[1] + 1) << 3))))
7be96f76 MN	94	return -1;
7be96f76 MN	95
9c70220b	96	mh = (struct ip6_mh *)skb_transport_header(skb);
7be96f76 MN	97
	98	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
	99	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
	100	mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
d56f90a7 ACM	101	mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
d56f90a7 ACM	102	skb_network_header(skb)));
7be96f76 MN	103	return -1;
7be96f76 MN	104	}
7be96f76 MN	105
	106	if (mh->ip6mh_proto != IPPROTO_NONE) {
	107	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
	108	mh->ip6mh_proto);
d56f90a7 ACM	109	mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
d56f90a7 ACM	110	skb_network_header(skb)));
7be96f76 MN	111	return -1;
	112	}
	113
	114	return 0;
	115	}
	116
70182ed2 MN	117	struct mip6_report_rate_limiter {
	118	spinlock_t lock;
	119	struct timeval stamp;
	120	int iif;
	121	struct in6_addr src;
	122	struct in6_addr dst;
	123	};
	124
	125	static struct mip6_report_rate_limiter mip6_report_rl = {
4ef8d0ae	126	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
70182ed2 MN	127	};
70182ed2 MN	128
3d126890 NT	129	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	130	{
b71d1d42	131	const struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890	132	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
0ebea8ef	133	int err = destopt->nexthdr;
3d126890	134
0ebea8ef	135	spin_lock(&x->lock);
3d126890 NT	136	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
3d126890 NT	137	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	138	err = -ENOENT;
0ebea8ef HX	139	spin_unlock(&x->lock);
3d126890	140
0ebea8ef	141	return err;
3d126890 NT	142	}
	143
	144	/* Destination Option Header is inserted.
	145	* IP Header's src address is replaced with Home Address Option in
	146	* Destination Option Header.
	147	*/
	148	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	149	{
	150	struct ipv6hdr *iph;
	151	struct ipv6_destopt_hdr *dstopt;
	152	struct ipv6_destopt_hao *hao;
	153	u8 nexthdr;
	154	int len;
	155
7b277b1a	156	skb_push(skb, -skb_network_offset(skb));
007f0211	157	iph = ipv6_hdr(skb);
3d126890	158
007f0211 HX	159	nexthdr = *skb_mac_header(skb);
007f0211 HX	160	*skb_mac_header(skb) = IPPROTO_DSTOPTS;
3d126890	161
9c70220b	162	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
3d126890 NT	163	dstopt->nexthdr = nexthdr;
	164
	165	hao = mip6_padn((char *)(dstopt + 1),
	166	calc_padlen(sizeof(*dstopt), 6));
	167
	168	hao->type = IPV6_TLV_HAO;
547b792c	169	BUILD_BUG_ON(sizeof(*hao) != 18);
3d126890	170	hao->length = sizeof(*hao) - 2;
3d126890 NT	171
	172	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	173
	174	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
b7c6538c	175	spin_lock_bh(&x->lock);
3d126890	176	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
b7c6538c	177	spin_unlock_bh(&x->lock);
3d126890	178
547b792c	179	WARN_ON(len != x->props.header_len);
3d126890 NT	180	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	181
	182	return 0;
	183	}
	184
70182ed2	185	static inline int mip6_report_rl_allow(struct timeval *stamp,
b71d1d42 ED	186	const struct in6_addr *dst,
b71d1d42 ED	187	const struct in6_addr *src, int iif)
70182ed2 MN	188	{
	189	int allow = 0;
	190
	191	spin_lock_bh(&mip6_report_rl.lock);
	192	if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec \|\|
	193	mip6_report_rl.stamp.tv_usec != stamp->tv_usec \|\|
	194	mip6_report_rl.iif != iif \|\|
	195	!ipv6_addr_equal(&mip6_report_rl.src, src) \|\|
	196	!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
	197	mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
	198	mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
	199	mip6_report_rl.iif = iif;
4e3fd7a0 AD	200	mip6_report_rl.src = *src;
4e3fd7a0 AD	201	mip6_report_rl.dst = *dst;
70182ed2 MN	202	allow = 1;
	203	}
	204	spin_unlock_bh(&mip6_report_rl.lock);
	205	return allow;
	206	}
	207
8f029de2 DM	208	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb,
8f029de2 DM	209	const struct flowi *fl)
70182ed2	210	{
db983c11	211	struct net *net = xs_net(x);
70182ed2	212	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
4c9483b2	213	const struct flowi6 *fl6 = &fl->u.ip6;
70182ed2 MN	214	struct ipv6_destopt_hao *hao = NULL;
	215	struct xfrm_selector sel;
	216	int offset;
	217	struct timeval stamp;
	218	int err = 0;
	219
4c9483b2	220	if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
1958b856	221	fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
01be8e5d MN	222	goto out;
01be8e5d MN	223
70182ed2 MN	224	if (likely(opt->dsthao)) {
	225	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	226	if (likely(offset >= 0))
d56f90a7 ACM	227	hao = (struct ipv6_destopt_hao *)
d56f90a7 ACM	228	(skb_network_header(skb) + offset);
70182ed2 MN	229	}
	230
	231	skb_get_timestamp(skb, &stamp);
	232
0660e03f ACM	233	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
0660e03f ACM	234	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
70182ed2 MN	235	opt->iif))
	236	goto out;
	237
	238	memset(&sel, 0, sizeof(sel));
0660e03f	239	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
70182ed2 MN	240	sizeof(sel.daddr));
70182ed2 MN	241	sel.prefixlen_d = 128;
0660e03f	242	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
70182ed2 MN	243	sizeof(sel.saddr));
	244	sel.prefixlen_s = 128;
	245	sel.family = AF_INET6;
4c9483b2 DM	246	sel.proto = fl6->flowi6_proto;
4c9483b2 DM	247	sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
70182ed2	248	if (sel.dport)
e69a4adc	249	sel.dport_mask = htons(~0);
4c9483b2	250	sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
70182ed2	251	if (sel.sport)
e69a4adc	252	sel.sport_mask = htons(~0);
4c9483b2	253	sel.ifindex = fl6->flowi6_oif;
70182ed2	254
db983c11	255	err = km_report(net, IPPROTO_DSTOPTS, &sel,
70182ed2 MN	256	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	257
	258	out:
	259	return err;
	260	}
	261
3d126890 NT	262	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	263	u8 **nexthdr)
	264	{
	265	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	266	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	267	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	268	const unsigned char *nh = skb_network_header(skb);
27a884dc	269	unsigned int packet_len = skb->tail - skb->network_header;
3d126890 NT	270	int found_rhdr = 0;
3d126890 NT	271
0660e03f	272	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	273
	274	while (offset + 1 <= packet_len) {
	275
	276	switch (**nexthdr) {
	277	case NEXTHDR_HOP:
	278	break;
	279	case NEXTHDR_ROUTING:
	280	found_rhdr = 1;
	281	break;
	282	case NEXTHDR_DEST:
	283	/*
	284	* HAO MUST NOT appear more than once.
	285	* XXX: It is better to try to find by the end of
	286	* XXX: packet if HAO exists.
	287	*/
	288	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	289	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	290	return offset;
	291	}
	292
	293	if (found_rhdr)
	294	return offset;
	295
	296	break;
	297	default:
	298	return offset;
	299	}
	300
	301	offset += ipv6_optlen(exthdr);
	302	*nexthdr = &exthdr->nexthdr;
d56f90a7	303	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	304	}
	305
	306	return offset;
	307	}
	308
	309	static int mip6_destopt_init_state(struct xfrm_state *x)
	310	{
	311	if (x->id.spi) {
f3213831	312	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
3d126890 NT	313	return -EINVAL;
	314	}
	315	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	316	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	317	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
3d126890 NT	318	return -EINVAL;
	319	}
	320
	321	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	322	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	323	sizeof(struct ipv6_destopt_hao);
547b792c	324	WARN_ON(x->props.header_len != 24);
3d126890 NT	325
	326	return 0;
	327	}
	328
	329	/*
	330	* Do nothing about destroying since it has no specific operation for
	331	* destination options header unlike IPsec protocols.
	332	*/
	333	static void mip6_destopt_destroy(struct xfrm_state *x)
	334	{
	335	}
	336
533cb5b0	337	static const struct xfrm_type mip6_destopt_type =
3d126890 NT	338	{
	339	.description = "MIP6DESTOPT",
	340	.owner = THIS_MODULE,
	341	.proto = IPPROTO_DSTOPTS,
f04e7e8d	342	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_LOCAL_COADDR,
3d126890 NT	343	.init_state = mip6_destopt_init_state,
	344	.destructor = mip6_destopt_destroy,
	345	.input = mip6_destopt_input,
	346	.output = mip6_destopt_output,
1ab1457c	347	.reject = mip6_destopt_reject,
3d126890	348	.hdr_offset = mip6_destopt_offset,
3d126890 NT	349	};
3d126890 NT	350
2c8d7ca0 NT	351	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
2c8d7ca0 NT	352	{
b71d1d42	353	const struct ipv6hdr *iph = ipv6_hdr(skb);
2c8d7ca0	354	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
0ebea8ef	355	int err = rt2->rt_hdr.nexthdr;
2c8d7ca0	356
0ebea8ef	357	spin_lock(&x->lock);
d9a9dc66	358	if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
2c8d7ca0	359	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	360	err = -ENOENT;
0ebea8ef HX	361	spin_unlock(&x->lock);
2c8d7ca0	362
0ebea8ef	363	return err;
2c8d7ca0 NT	364	}
	365
	366	/* Routing Header type 2 is inserted.
	367	* IP Header's dst address is replaced with Routing Header's Home Address.
	368	*/
	369	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	370	{
	371	struct ipv6hdr *iph;
	372	struct rt2_hdr *rt2;
	373	u8 nexthdr;
	374
7b277b1a	375	skb_push(skb, -skb_network_offset(skb));
007f0211	376	iph = ipv6_hdr(skb);
2c8d7ca0	377
007f0211 HX	378	nexthdr = *skb_mac_header(skb);
007f0211 HX	379	*skb_mac_header(skb) = IPPROTO_ROUTING;
2c8d7ca0	380
9c70220b	381	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
2c8d7ca0 NT	382	rt2->rt_hdr.nexthdr = nexthdr;
	383	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	384	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	385	rt2->rt_hdr.segments_left = 1;
	386	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	387
547b792c	388	WARN_ON(rt2->rt_hdr.hdrlen != 2);
2c8d7ca0 NT	389
2c8d7ca0 NT	390	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
b7c6538c	391	spin_lock_bh(&x->lock);
2c8d7ca0	392	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
b7c6538c	393	spin_unlock_bh(&x->lock);
2c8d7ca0 NT	394
	395	return 0;
	396	}
	397
	398	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	399	u8 **nexthdr)
	400	{
	401	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	402	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	403	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	404	const unsigned char *nh = skb_network_header(skb);
27a884dc	405	unsigned int packet_len = skb->tail - skb->network_header;
2c8d7ca0 NT	406	int found_rhdr = 0;
2c8d7ca0 NT	407
0660e03f	408	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	409
	410	while (offset + 1 <= packet_len) {
	411
	412	switch (**nexthdr) {
	413	case NEXTHDR_HOP:
	414	break;
	415	case NEXTHDR_ROUTING:
	416	if (offset + 3 <= packet_len) {
	417	struct ipv6_rt_hdr *rt;
d56f90a7	418	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	419	if (rt->type != 0)
	420	return offset;
	421	}
	422	found_rhdr = 1;
	423	break;
	424	case NEXTHDR_DEST:
	425	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	426	return offset;
	427
	428	if (found_rhdr)
	429	return offset;
	430
	431	break;
	432	default:
	433	return offset;
	434	}
	435
	436	offset += ipv6_optlen(exthdr);
	437	*nexthdr = &exthdr->nexthdr;
d56f90a7	438	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	439	}
	440
	441	return offset;
	442	}
	443
	444	static int mip6_rthdr_init_state(struct xfrm_state *x)
	445	{
	446	if (x->id.spi) {
f3213831	447	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
2c8d7ca0 NT	448	return -EINVAL;
	449	}
	450	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	451	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	452	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
2c8d7ca0 NT	453	return -EINVAL;
	454	}
	455
	456	x->props.header_len = sizeof(struct rt2_hdr);
	457
	458	return 0;
	459	}
	460
	461	/*
	462	* Do nothing about destroying since it has no specific operation for routing
	463	* header type 2 unlike IPsec protocols.
	464	*/
	465	static void mip6_rthdr_destroy(struct xfrm_state *x)
	466	{
	467	}
	468
533cb5b0	469	static const struct xfrm_type mip6_rthdr_type =
2c8d7ca0 NT	470	{
	471	.description = "MIP6RT",
	472	.owner = THIS_MODULE,
	473	.proto = IPPROTO_ROUTING,
f04e7e8d	474	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_REMOTE_COADDR,
2c8d7ca0 NT	475	.init_state = mip6_rthdr_init_state,
	476	.destructor = mip6_rthdr_destroy,
	477	.input = mip6_rthdr_input,
	478	.output = mip6_rthdr_output,
	479	.hdr_offset = mip6_rthdr_offset,
2c8d7ca0 NT	480	};
2c8d7ca0 NT	481
59fbb3a6	482	static int __init mip6_init(void)
2c8d7ca0	483	{
f3213831	484	pr_info("Mobile IPv6\n");
2c8d7ca0	485
3d126890	486	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
f3213831	487	pr_info("%s: can't add xfrm type(destopt)\n", __func__);
3d126890 NT	488	goto mip6_destopt_xfrm_fail;
3d126890 NT	489	}
2c8d7ca0	490	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
f3213831	491	pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
2c8d7ca0 NT	492	goto mip6_rthdr_xfrm_fail;
2c8d7ca0 NT	493	}
59fbb3a6	494	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
f3213831	495	pr_info("%s: can't add rawv6 mh filter\n", __func__);
59fbb3a6 MN	496	goto mip6_rawv6_mh_fail;
	497	}
	498
	499
2c8d7ca0 NT	500	return 0;
2c8d7ca0 NT	501
59fbb3a6 MN	502	mip6_rawv6_mh_fail:
59fbb3a6 MN	503	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
2c8d7ca0	504	mip6_rthdr_xfrm_fail:
3d126890 NT	505	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
3d126890 NT	506	mip6_destopt_xfrm_fail:
2c8d7ca0 NT	507	return -EAGAIN;
	508	}
	509
59fbb3a6	510	static void __exit mip6_fini(void)
2c8d7ca0	511	{
59fbb3a6	512	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
f3213831	513	pr_info("%s: can't remove rawv6 mh filter\n", __func__);
2c8d7ca0	514	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
f3213831	515	pr_info("%s: can't remove xfrm type(rthdr)\n", __func__);
3d126890	516	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
f3213831	517	pr_info("%s: can't remove xfrm type(destopt)\n", __func__);
2c8d7ca0	518	}
59fbb3a6 MN	519
	520	module_init(mip6_init);
	521	module_exit(mip6_fini);
	522
	523	MODULE_LICENSE("GPL");
d3d6dd3a MN	524	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
d3d6dd3a MN	525	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);