[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
 */

#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,
			       const 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
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>
59fbb3a6	33	#include <net/rawv6.h>
2c8d7ca0 NT	34	#include <net/xfrm.h>
	35	#include <net/mip6.h>
	36
3d126890 NT	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) {
7f1eced8	47	data[0] = IPV6_TLV_PAD0;
3d126890	48	} else if (padlen > 1) {
7f1eced8	49	data[0] = IPV6_TLV_PADN;
3d126890 NT	50	data[1] = padlen - 2;
	51	if (padlen > 2)
	52	memset(data+2, 0, data[1]);
	53	}
	54	return data + padlen;
	55	}
	56
d5fdd6ba	57	static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
7be96f76	58	{
3ffe533c	59	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
7be96f76 MN	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
59fbb3a6	85	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
7be96f76 MN	86	{
7be96f76 MN	87	struct ip6_mh *mh;
7be96f76	88
ea2ae17d ACM	89	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) \|\|
ea2ae17d ACM	90	!pskb_may_pull(skb, (skb_transport_offset(skb) +
9c70220b	91	((skb_transport_header(skb)[1] + 1) << 3))))
7be96f76 MN	92	return -1;
7be96f76 MN	93
9c70220b	94	mh = (struct ip6_mh *)skb_transport_header(skb);
7be96f76 MN	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));
d56f90a7 ACM	99	mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
d56f90a7 ACM	100	skb_network_header(skb)));
7be96f76 MN	101	return -1;
7be96f76 MN	102	}
7be96f76 MN	103
	104	if (mh->ip6mh_proto != IPPROTO_NONE) {
	105	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
	106	mh->ip6mh_proto);
d56f90a7 ACM	107	mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
d56f90a7 ACM	108	skb_network_header(skb)));
7be96f76 MN	109	return -1;
	110	}
	111
	112	return 0;
	113	}
	114
70182ed2 MN	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 = {
4ef8d0ae	124	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
70182ed2 MN	125	};
70182ed2 MN	126
3d126890 NT	127	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	128	{
0660e03f	129	struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890	130	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
0ebea8ef	131	int err = destopt->nexthdr;
3d126890	132
0ebea8ef	133	spin_lock(&x->lock);
3d126890 NT	134	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
3d126890 NT	135	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	136	err = -ENOENT;
0ebea8ef HX	137	spin_unlock(&x->lock);
3d126890	138
0ebea8ef	139	return err;
3d126890 NT	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
7b277b1a	154	skb_push(skb, -skb_network_offset(skb));
007f0211	155	iph = ipv6_hdr(skb);
3d126890	156
007f0211 HX	157	nexthdr = *skb_mac_header(skb);
007f0211 HX	158	*skb_mac_header(skb) = IPPROTO_DSTOPTS;
3d126890	159
9c70220b	160	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
3d126890 NT	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;
547b792c	167	BUILD_BUG_ON(sizeof(*hao) != 18);
3d126890	168	hao->length = sizeof(*hao) - 2;
3d126890 NT	169
	170	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	171
	172	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
b7c6538c	173	spin_lock_bh(&x->lock);
3d126890	174	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
b7c6538c	175	spin_unlock_bh(&x->lock);
3d126890	176
547b792c	177	WARN_ON(len != x->props.header_len);
3d126890 NT	178	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	179
	180	return 0;
	181	}
	182
70182ed2 MN	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
8f029de2 DM	206	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb,
8f029de2 DM	207	const struct flowi *fl)
70182ed2	208	{
db983c11	209	struct net *net = xs_net(x);
70182ed2 MN	210	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
	211	struct ipv6_destopt_hao *hao = NULL;
	212	struct xfrm_selector sel;
	213	int offset;
	214	struct timeval stamp;
	215	int err = 0;
	216
e731c248 YH	217	if (unlikely(fl->proto == IPPROTO_MH &&
e731c248 YH	218	fl->fl_mh_type <= IP6_MH_TYPE_MAX))
01be8e5d MN	219	goto out;
01be8e5d MN	220
70182ed2 MN	221	if (likely(opt->dsthao)) {
	222	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	223	if (likely(offset >= 0))
d56f90a7 ACM	224	hao = (struct ipv6_destopt_hao *)
d56f90a7 ACM	225	(skb_network_header(skb) + offset);
70182ed2 MN	226	}
	227
	228	skb_get_timestamp(skb, &stamp);
	229
0660e03f ACM	230	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
0660e03f ACM	231	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
70182ed2 MN	232	opt->iif))
	233	goto out;
	234
	235	memset(&sel, 0, sizeof(sel));
0660e03f	236	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
70182ed2 MN	237	sizeof(sel.daddr));
70182ed2 MN	238	sel.prefixlen_d = 128;
0660e03f	239	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
70182ed2 MN	240	sizeof(sel.saddr));
	241	sel.prefixlen_s = 128;
	242	sel.family = AF_INET6;
	243	sel.proto = fl->proto;
	244	sel.dport = xfrm_flowi_dport(fl);
	245	if (sel.dport)
e69a4adc	246	sel.dport_mask = htons(~0);
70182ed2 MN	247	sel.sport = xfrm_flowi_sport(fl);
70182ed2 MN	248	if (sel.sport)
e69a4adc	249	sel.sport_mask = htons(~0);
70182ed2 MN	250	sel.ifindex = fl->oif;
70182ed2 MN	251
db983c11	252	err = km_report(net, IPPROTO_DSTOPTS, &sel,
70182ed2 MN	253	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	254
	255	out:
	256	return err;
	257	}
	258
3d126890 NT	259	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	260	u8 **nexthdr)
	261	{
	262	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	263	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	264	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	265	const unsigned char *nh = skb_network_header(skb);
27a884dc	266	unsigned int packet_len = skb->tail - skb->network_header;
3d126890 NT	267	int found_rhdr = 0;
3d126890 NT	268
0660e03f	269	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	270
	271	while (offset + 1 <= packet_len) {
	272
	273	switch (**nexthdr) {
	274	case NEXTHDR_HOP:
	275	break;
	276	case NEXTHDR_ROUTING:
	277	found_rhdr = 1;
	278	break;
	279	case NEXTHDR_DEST:
	280	/*
	281	* HAO MUST NOT appear more than once.
	282	* XXX: It is better to try to find by the end of
	283	* XXX: packet if HAO exists.
	284	*/
	285	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	286	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	287	return offset;
	288	}
	289
	290	if (found_rhdr)
	291	return offset;
	292
	293	break;
	294	default:
	295	return offset;
	296	}
	297
	298	offset += ipv6_optlen(exthdr);
	299	*nexthdr = &exthdr->nexthdr;
d56f90a7	300	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	301	}
	302
	303	return offset;
	304	}
	305
	306	static int mip6_destopt_init_state(struct xfrm_state *x)
	307	{
	308	if (x->id.spi) {
0dc47877	309	printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
3d126890 NT	310	x->id.spi);
	311	return -EINVAL;
	312	}
	313	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	314	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
0dc47877	315	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
3d126890 NT	316	return -EINVAL;
	317	}
	318
	319	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	320	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	321	sizeof(struct ipv6_destopt_hao);
547b792c	322	WARN_ON(x->props.header_len != 24);
3d126890 NT	323
	324	return 0;
	325	}
	326
	327	/*
	328	* Do nothing about destroying since it has no specific operation for
	329	* destination options header unlike IPsec protocols.
	330	*/
	331	static void mip6_destopt_destroy(struct xfrm_state *x)
	332	{
	333	}
	334
533cb5b0	335	static const struct xfrm_type mip6_destopt_type =
3d126890 NT	336	{
	337	.description = "MIP6DESTOPT",
	338	.owner = THIS_MODULE,
	339	.proto = IPPROTO_DSTOPTS,
f04e7e8d	340	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_LOCAL_COADDR,
3d126890 NT	341	.init_state = mip6_destopt_init_state,
	342	.destructor = mip6_destopt_destroy,
	343	.input = mip6_destopt_input,
	344	.output = mip6_destopt_output,
1ab1457c	345	.reject = mip6_destopt_reject,
3d126890	346	.hdr_offset = mip6_destopt_offset,
3d126890 NT	347	};
3d126890 NT	348
2c8d7ca0 NT	349	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
2c8d7ca0 NT	350	{
d9a9dc66	351	struct ipv6hdr *iph = ipv6_hdr(skb);
2c8d7ca0	352	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
0ebea8ef	353	int err = rt2->rt_hdr.nexthdr;
2c8d7ca0	354
0ebea8ef	355	spin_lock(&x->lock);
d9a9dc66	356	if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
2c8d7ca0	357	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	358	err = -ENOENT;
0ebea8ef HX	359	spin_unlock(&x->lock);
2c8d7ca0	360
0ebea8ef	361	return err;
2c8d7ca0 NT	362	}
	363
	364	/* Routing Header type 2 is inserted.
	365	* IP Header's dst address is replaced with Routing Header's Home Address.
	366	*/
	367	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	368	{
	369	struct ipv6hdr *iph;
	370	struct rt2_hdr *rt2;
	371	u8 nexthdr;
	372
7b277b1a	373	skb_push(skb, -skb_network_offset(skb));
007f0211	374	iph = ipv6_hdr(skb);
2c8d7ca0	375
007f0211 HX	376	nexthdr = *skb_mac_header(skb);
007f0211 HX	377	*skb_mac_header(skb) = IPPROTO_ROUTING;
2c8d7ca0	378
9c70220b	379	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
2c8d7ca0 NT	380	rt2->rt_hdr.nexthdr = nexthdr;
	381	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	382	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	383	rt2->rt_hdr.segments_left = 1;
	384	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	385
547b792c	386	WARN_ON(rt2->rt_hdr.hdrlen != 2);
2c8d7ca0 NT	387
2c8d7ca0 NT	388	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
b7c6538c	389	spin_lock_bh(&x->lock);
2c8d7ca0	390	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
b7c6538c	391	spin_unlock_bh(&x->lock);
2c8d7ca0 NT	392
	393	return 0;
	394	}
	395
	396	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	397	u8 **nexthdr)
	398	{
	399	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	400	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	401	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	402	const unsigned char *nh = skb_network_header(skb);
27a884dc	403	unsigned int packet_len = skb->tail - skb->network_header;
2c8d7ca0 NT	404	int found_rhdr = 0;
2c8d7ca0 NT	405
0660e03f	406	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	407
	408	while (offset + 1 <= packet_len) {
	409
	410	switch (**nexthdr) {
	411	case NEXTHDR_HOP:
	412	break;
	413	case NEXTHDR_ROUTING:
	414	if (offset + 3 <= packet_len) {
	415	struct ipv6_rt_hdr *rt;
d56f90a7	416	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	417	if (rt->type != 0)
	418	return offset;
	419	}
	420	found_rhdr = 1;
	421	break;
	422	case NEXTHDR_DEST:
	423	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	424	return offset;
	425
	426	if (found_rhdr)
	427	return offset;
	428
	429	break;
	430	default:
	431	return offset;
	432	}
	433
	434	offset += ipv6_optlen(exthdr);
	435	*nexthdr = &exthdr->nexthdr;
d56f90a7	436	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	437	}
	438
	439	return offset;
	440	}
	441
	442	static int mip6_rthdr_init_state(struct xfrm_state *x)
	443	{
	444	if (x->id.spi) {
0dc47877	445	printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
2c8d7ca0 NT	446	x->id.spi);
	447	return -EINVAL;
	448	}
	449	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	450	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
0dc47877	451	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
2c8d7ca0 NT	452	return -EINVAL;
	453	}
	454
	455	x->props.header_len = sizeof(struct rt2_hdr);
	456
	457	return 0;
	458	}
	459
	460	/*
	461	* Do nothing about destroying since it has no specific operation for routing
	462	* header type 2 unlike IPsec protocols.
	463	*/
	464	static void mip6_rthdr_destroy(struct xfrm_state *x)
	465	{
	466	}
	467
533cb5b0	468	static const struct xfrm_type mip6_rthdr_type =
2c8d7ca0 NT	469	{
	470	.description = "MIP6RT",
	471	.owner = THIS_MODULE,
	472	.proto = IPPROTO_ROUTING,
f04e7e8d	473	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_REMOTE_COADDR,
2c8d7ca0 NT	474	.init_state = mip6_rthdr_init_state,
	475	.destructor = mip6_rthdr_destroy,
	476	.input = mip6_rthdr_input,
	477	.output = mip6_rthdr_output,
	478	.hdr_offset = mip6_rthdr_offset,
2c8d7ca0 NT	479	};
2c8d7ca0 NT	480
59fbb3a6	481	static int __init mip6_init(void)
2c8d7ca0 NT	482	{
	483	printk(KERN_INFO "Mobile IPv6\n");
	484
3d126890	485	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
0dc47877	486	printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __func__);
3d126890 NT	487	goto mip6_destopt_xfrm_fail;
3d126890 NT	488	}
2c8d7ca0	489	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
0dc47877	490	printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __func__);
2c8d7ca0 NT	491	goto mip6_rthdr_xfrm_fail;
2c8d7ca0 NT	492	}
59fbb3a6	493	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
0dc47877	494	printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __func__);
59fbb3a6 MN	495	goto mip6_rawv6_mh_fail;
	496	}
	497
	498
2c8d7ca0 NT	499	return 0;
2c8d7ca0 NT	500
59fbb3a6 MN	501	mip6_rawv6_mh_fail:
59fbb3a6 MN	502	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
2c8d7ca0	503	mip6_rthdr_xfrm_fail:
3d126890 NT	504	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
3d126890 NT	505	mip6_destopt_xfrm_fail:
2c8d7ca0 NT	506	return -EAGAIN;
	507	}
	508
59fbb3a6	509	static void __exit mip6_fini(void)
2c8d7ca0	510	{
59fbb3a6	511	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
0dc47877	512	printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
2c8d7ca0	513	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
0dc47877	514	printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
3d126890	515	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
0dc47877	516	printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
2c8d7ca0	517	}
59fbb3a6 MN	518
	519	module_init(mip6_init);
	520	module_exit(mip6_fini);
	521
	522	MODULE_LICENSE("GPL");
d3d6dd3a MN	523	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
d3d6dd3a MN	524	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);