[linux-2.6-block.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, see <http://www.gnu.org/licenses/>.
 */
/*
 * 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 _hdr;
	const struct ip6_mh *mh;

	mh = skb_header_pointer(skb, skb_transport_offset(skb),
				sizeof(_hdr), &_hdr);
	if (!mh)
		return -1;

	if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
		return -1;

	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
		net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n",
				    mh->ip6mh_hdrlen,
				    mip6_mh_len(mh->ip6mh_type));
		mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
				skb_network_header_len(skb));
		return -1;
	}

	if (mh->ip6mh_proto != IPPROTO_NONE) {
		net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n",
				    mh->ip6mh_proto);
		mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
				skb_network_header_len(skb));
		return -1;
	}

	return 0;
}

struct mip6_report_rate_limiter {
	spinlock_t lock;
	ktime_t 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(ktime_t stamp,
				       const struct in6_addr *dst,
				       const struct in6_addr *src, int iif)
{
	int allow = 0;

	spin_lock_bh(&mip6_report_rl.lock);
	if (!ktime_equal(mip6_report_rl.stamp, stamp) ||
	    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 = stamp;
		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;
	ktime_t 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);
	}

	stamp = skb_get_ktime(skb);

	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_pointer(skb) -
		skb_network_header(skb);
	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) {
				net_dbg_ratelimited("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_pointer(skb) -
		skb_network_header(skb);
	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
a99421d9	16	* along with this program; if not, see <http://www.gnu.org/licenses/>.
2c8d7ca0 NT	17	*/
	18	/*
	19	* Authors:
	20	* Noriaki TAKAMIYA @USAGI
	21	* Masahide NAKAMURA @USAGI
	22	*/
	23
f3213831 JP	24	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
f3213831 JP	25
2c8d7ca0 NT	26	#include <linux/module.h>
2c8d7ca0 NT	27	#include <linux/skbuff.h>
70182ed2	28	#include <linux/time.h>
2c8d7ca0	29	#include <linux/ipv6.h>
7be96f76 MN	30	#include <linux/icmpv6.h>
7be96f76 MN	31	#include <net/sock.h>
2c8d7ca0	32	#include <net/ipv6.h>
7be96f76	33	#include <net/ip6_checksum.h>
59fbb3a6	34	#include <net/rawv6.h>
2c8d7ca0 NT	35	#include <net/xfrm.h>
	36	#include <net/mip6.h>
	37
3d126890 NT	38	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	39	{
	40	return (n - len + 16) & 0x7;
	41	}
	42
	43	static inline void mip6_padn(__u8 data, __u8 padlen)
	44	{
	45	if (!data)
	46	return NULL;
	47	if (padlen == 1) {
1de5a71c	48	data[0] = IPV6_TLV_PAD1;
3d126890	49	} else if (padlen > 1) {
7f1eced8	50	data[0] = IPV6_TLV_PADN;
3d126890 NT	51	data[1] = padlen - 2;
	52	if (padlen > 2)
	53	memset(data+2, 0, data[1]);
	54	}
	55	return data + padlen;
	56	}
	57
d5fdd6ba	58	static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
7be96f76	59	{
3ffe533c	60	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
7be96f76 MN	61	}
	62
	63	static int mip6_mh_len(int type)
	64	{
	65	int len = 0;
	66
	67	switch (type) {
	68	case IP6_MH_TYPE_BRR:
	69	len = 0;
	70	break;
	71	case IP6_MH_TYPE_HOTI:
	72	case IP6_MH_TYPE_COTI:
	73	case IP6_MH_TYPE_BU:
	74	case IP6_MH_TYPE_BACK:
	75	len = 1;
	76	break;
	77	case IP6_MH_TYPE_HOT:
	78	case IP6_MH_TYPE_COT:
	79	case IP6_MH_TYPE_BERROR:
	80	len = 2;
	81	break;
	82	}
	83	return len;
	84	}
	85
59fbb3a6	86	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
7be96f76	87	{
96af69ea ED	88	struct ip6_mh _hdr;
96af69ea ED	89	const struct ip6_mh *mh;
7be96f76	90
96af69ea ED	91	mh = skb_header_pointer(skb, skb_transport_offset(skb),
	92	sizeof(_hdr), &_hdr);
	93	if (!mh)
7be96f76 MN	94	return -1;
7be96f76 MN	95
96af69ea ED	96	if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
96af69ea ED	97	return -1;
7be96f76 MN	98
7be96f76 MN	99	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
ba7a46f1 JP	100	net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n",
	101	mh->ip6mh_hdrlen,
	102	mip6_mh_len(mh->ip6mh_type));
96af69ea ED	103	mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
96af69ea ED	104	skb_network_header_len(skb));
7be96f76 MN	105	return -1;
7be96f76 MN	106	}
7be96f76 MN	107
7be96f76 MN	108	if (mh->ip6mh_proto != IPPROTO_NONE) {
ba7a46f1 JP	109	net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n",
ba7a46f1 JP	110	mh->ip6mh_proto);
96af69ea ED	111	mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
96af69ea ED	112	skb_network_header_len(skb));
7be96f76 MN	113	return -1;
	114	}
	115
	116	return 0;
	117	}
	118
70182ed2 MN	119	struct mip6_report_rate_limiter {
70182ed2 MN	120	spinlock_t lock;
3dd7669f	121	ktime_t stamp;
70182ed2 MN	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 = {
4ef8d0ae	128	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
70182ed2 MN	129	};
70182ed2 MN	130
3d126890 NT	131	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	132	{
b71d1d42	133	const struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890	134	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
0ebea8ef	135	int err = destopt->nexthdr;
3d126890	136
0ebea8ef	137	spin_lock(&x->lock);
3d126890 NT	138	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
3d126890 NT	139	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	140	err = -ENOENT;
0ebea8ef HX	141	spin_unlock(&x->lock);
3d126890	142
0ebea8ef	143	return err;
3d126890 NT	144	}
	145
	146	/* Destination Option Header is inserted.
	147	* IP Header's src address is replaced with Home Address Option in
	148	* Destination Option Header.
	149	*/
	150	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	151	{
	152	struct ipv6hdr *iph;
	153	struct ipv6_destopt_hdr *dstopt;
	154	struct ipv6_destopt_hao *hao;
	155	u8 nexthdr;
	156	int len;
	157
7b277b1a	158	skb_push(skb, -skb_network_offset(skb));
007f0211	159	iph = ipv6_hdr(skb);
3d126890	160
007f0211 HX	161	nexthdr = *skb_mac_header(skb);
007f0211 HX	162	*skb_mac_header(skb) = IPPROTO_DSTOPTS;
3d126890	163
9c70220b	164	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
3d126890 NT	165	dstopt->nexthdr = nexthdr;
	166
	167	hao = mip6_padn((char *)(dstopt + 1),
	168	calc_padlen(sizeof(*dstopt), 6));
	169
	170	hao->type = IPV6_TLV_HAO;
547b792c	171	BUILD_BUG_ON(sizeof(*hao) != 18);
3d126890	172	hao->length = sizeof(*hao) - 2;
3d126890 NT	173
	174	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	175
	176	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
b7c6538c	177	spin_lock_bh(&x->lock);
3d126890	178	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
b7c6538c	179	spin_unlock_bh(&x->lock);
3d126890	180
547b792c	181	WARN_ON(len != x->props.header_len);
3d126890 NT	182	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	183
	184	return 0;
	185	}
	186
3dd7669f	187	static inline int mip6_report_rl_allow(ktime_t stamp,
b71d1d42 ED	188	const struct in6_addr *dst,
b71d1d42 ED	189	const struct in6_addr *src, int iif)
70182ed2 MN	190	{
	191	int allow = 0;
	192
	193	spin_lock_bh(&mip6_report_rl.lock);
3dd7669f	194	if (!ktime_equal(mip6_report_rl.stamp, stamp) \|\|
70182ed2 MN	195	mip6_report_rl.iif != iif \|\|
	196	!ipv6_addr_equal(&mip6_report_rl.src, src) \|\|
	197	!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
3dd7669f	198	mip6_report_rl.stamp = stamp;
70182ed2	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;
3dd7669f	217	ktime_t stamp;
70182ed2 MN	218	int err = 0;
70182ed2 MN	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	}
70182ed2 MN	230
3dd7669f	231	stamp = skb_get_ktime(skb);
70182ed2	232
3dd7669f	233	if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr,
0660e03f	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);
29a3cad5 SH	269	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	270	skb_network_header(skb);
3d126890 NT	271	int found_rhdr = 0;
3d126890 NT	272
0660e03f	273	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	274
	275	while (offset + 1 <= packet_len) {
	276
	277	switch (**nexthdr) {
	278	case NEXTHDR_HOP:
	279	break;
	280	case NEXTHDR_ROUTING:
	281	found_rhdr = 1;
	282	break;
	283	case NEXTHDR_DEST:
	284	/*
	285	* HAO MUST NOT appear more than once.
	286	* XXX: It is better to try to find by the end of
	287	* XXX: packet if HAO exists.
	288	*/
	289	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
ba7a46f1	290	net_dbg_ratelimited("mip6: hao exists already, override\n");
3d126890 NT	291	return offset;
	292	}
	293
	294	if (found_rhdr)
	295	return offset;
	296
	297	break;
	298	default:
	299	return offset;
	300	}
	301
	302	offset += ipv6_optlen(exthdr);
	303	*nexthdr = &exthdr->nexthdr;
d56f90a7	304	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	305	}
	306
	307	return offset;
	308	}
	309
	310	static int mip6_destopt_init_state(struct xfrm_state *x)
	311	{
	312	if (x->id.spi) {
f3213831	313	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
3d126890 NT	314	return -EINVAL;
	315	}
	316	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	317	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	318	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
3d126890 NT	319	return -EINVAL;
	320	}
	321
	322	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	323	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	324	sizeof(struct ipv6_destopt_hao);
547b792c	325	WARN_ON(x->props.header_len != 24);
3d126890 NT	326
	327	return 0;
	328	}
	329
	330	/*
	331	* Do nothing about destroying since it has no specific operation for
	332	* destination options header unlike IPsec protocols.
	333	*/
	334	static void mip6_destopt_destroy(struct xfrm_state *x)
	335	{
	336	}
	337
cc24beca	338	static const struct xfrm_type mip6_destopt_type = {
3d126890 NT	339	.description = "MIP6DESTOPT",
3d126890 NT	340	.owner = THIS_MODULE,
cc24beca	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);
29a3cad5 SH	405	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	406	skb_network_header(skb);
2c8d7ca0 NT	407	int found_rhdr = 0;
2c8d7ca0 NT	408
0660e03f	409	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	410
	411	while (offset + 1 <= packet_len) {
	412
	413	switch (**nexthdr) {
	414	case NEXTHDR_HOP:
	415	break;
	416	case NEXTHDR_ROUTING:
	417	if (offset + 3 <= packet_len) {
	418	struct ipv6_rt_hdr *rt;
d56f90a7	419	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	420	if (rt->type != 0)
	421	return offset;
	422	}
	423	found_rhdr = 1;
	424	break;
	425	case NEXTHDR_DEST:
	426	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	427	return offset;
	428
	429	if (found_rhdr)
	430	return offset;
	431
	432	break;
	433	default:
	434	return offset;
	435	}
	436
	437	offset += ipv6_optlen(exthdr);
	438	*nexthdr = &exthdr->nexthdr;
d56f90a7	439	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	440	}
	441
	442	return offset;
	443	}
	444
	445	static int mip6_rthdr_init_state(struct xfrm_state *x)
	446	{
	447	if (x->id.spi) {
f3213831	448	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
2c8d7ca0 NT	449	return -EINVAL;
	450	}
	451	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	452	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	453	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
2c8d7ca0 NT	454	return -EINVAL;
	455	}
	456
	457	x->props.header_len = sizeof(struct rt2_hdr);
	458
	459	return 0;
	460	}
	461
	462	/*
	463	* Do nothing about destroying since it has no specific operation for routing
	464	* header type 2 unlike IPsec protocols.
	465	*/
	466	static void mip6_rthdr_destroy(struct xfrm_state *x)
	467	{
	468	}
	469
cc24beca	470	static const struct xfrm_type mip6_rthdr_type = {
2c8d7ca0 NT	471	.description = "MIP6RT",
2c8d7ca0 NT	472	.owner = THIS_MODULE,
cc24beca	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);