[linux.git] / net / ipv6 / mip6.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C)2003-2006 Helsinki University of Technology
 * Copyright (C)2003-2006 USAGI/WIDE Project
 */
/*
 * 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 (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__);
	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
}

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
1ccea77e	1	// SPDX-License-Identifier: GPL-2.0-or-later
2c8d7ca0 NT	2	/*
	3	* Copyright (C)2003-2006 Helsinki University of Technology
	4	* Copyright (C)2003-2006 USAGI/WIDE Project
2c8d7ca0 NT	5	*/
	6	/*
	7	* Authors:
	8	* Noriaki TAKAMIYA @USAGI
	9	* Masahide NAKAMURA @USAGI
	10	*/
	11
f3213831 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
f3213831 JP	13
2c8d7ca0 NT	14	#include <linux/module.h>
2c8d7ca0 NT	15	#include <linux/skbuff.h>
70182ed2	16	#include <linux/time.h>
2c8d7ca0	17	#include <linux/ipv6.h>
7be96f76 MN	18	#include <linux/icmpv6.h>
7be96f76 MN	19	#include <net/sock.h>
2c8d7ca0	20	#include <net/ipv6.h>
7be96f76	21	#include <net/ip6_checksum.h>
59fbb3a6	22	#include <net/rawv6.h>
2c8d7ca0 NT	23	#include <net/xfrm.h>
	24	#include <net/mip6.h>
	25
3d126890 NT	26	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	27	{
	28	return (n - len + 16) & 0x7;
	29	}
	30
	31	static inline void mip6_padn(__u8 data, __u8 padlen)
	32	{
	33	if (!data)
	34	return NULL;
	35	if (padlen == 1) {
1de5a71c	36	data[0] = IPV6_TLV_PAD1;
3d126890	37	} else if (padlen > 1) {
7f1eced8	38	data[0] = IPV6_TLV_PADN;
3d126890 NT	39	data[1] = padlen - 2;
	40	if (padlen > 2)
	41	memset(data+2, 0, data[1]);
	42	}
	43	return data + padlen;
	44	}
	45
d5fdd6ba	46	static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
7be96f76	47	{
3ffe533c	48	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
7be96f76 MN	49	}
	50
	51	static int mip6_mh_len(int type)
	52	{
	53	int len = 0;
	54
	55	switch (type) {
	56	case IP6_MH_TYPE_BRR:
	57	len = 0;
	58	break;
	59	case IP6_MH_TYPE_HOTI:
	60	case IP6_MH_TYPE_COTI:
	61	case IP6_MH_TYPE_BU:
	62	case IP6_MH_TYPE_BACK:
	63	len = 1;
	64	break;
	65	case IP6_MH_TYPE_HOT:
	66	case IP6_MH_TYPE_COT:
	67	case IP6_MH_TYPE_BERROR:
	68	len = 2;
	69	break;
	70	}
	71	return len;
	72	}
	73
59fbb3a6	74	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
7be96f76	75	{
96af69ea ED	76	struct ip6_mh _hdr;
96af69ea ED	77	const struct ip6_mh *mh;
7be96f76	78
96af69ea ED	79	mh = skb_header_pointer(skb, skb_transport_offset(skb),
	80	sizeof(_hdr), &_hdr);
	81	if (!mh)
7be96f76 MN	82	return -1;
7be96f76 MN	83
96af69ea ED	84	if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
96af69ea ED	85	return -1;
7be96f76 MN	86
7be96f76 MN	87	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
ba7a46f1 JP	88	net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n",
	89	mh->ip6mh_hdrlen,
	90	mip6_mh_len(mh->ip6mh_type));
96af69ea ED	91	mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
96af69ea ED	92	skb_network_header_len(skb));
7be96f76 MN	93	return -1;
7be96f76 MN	94	}
7be96f76 MN	95
7be96f76 MN	96	if (mh->ip6mh_proto != IPPROTO_NONE) {
ba7a46f1 JP	97	net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n",
ba7a46f1 JP	98	mh->ip6mh_proto);
96af69ea ED	99	mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
96af69ea ED	100	skb_network_header_len(skb));
7be96f76 MN	101	return -1;
	102	}
	103
	104	return 0;
	105	}
	106
70182ed2 MN	107	struct mip6_report_rate_limiter {
70182ed2 MN	108	spinlock_t lock;
3dd7669f	109	ktime_t stamp;
70182ed2 MN	110	int iif;
	111	struct in6_addr src;
	112	struct in6_addr dst;
	113	};
	114
	115	static struct mip6_report_rate_limiter mip6_report_rl = {
4ef8d0ae	116	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
70182ed2 MN	117	};
70182ed2 MN	118
3d126890 NT	119	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	120	{
b71d1d42	121	const struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890	122	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
0ebea8ef	123	int err = destopt->nexthdr;
3d126890	124
0ebea8ef	125	spin_lock(&x->lock);
3d126890 NT	126	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
3d126890 NT	127	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	128	err = -ENOENT;
0ebea8ef HX	129	spin_unlock(&x->lock);
3d126890	130
0ebea8ef	131	return err;
3d126890 NT	132	}
	133
	134	/* Destination Option Header is inserted.
	135	* IP Header's src address is replaced with Home Address Option in
	136	* Destination Option Header.
	137	*/
	138	static int mip6_destopt_output(struct xfrm_state x, struct sk_buff skb)
	139	{
	140	struct ipv6hdr *iph;
	141	struct ipv6_destopt_hdr *dstopt;
	142	struct ipv6_destopt_hao *hao;
	143	u8 nexthdr;
	144	int len;
	145
7b277b1a	146	skb_push(skb, -skb_network_offset(skb));
007f0211	147	iph = ipv6_hdr(skb);
3d126890	148
007f0211 HX	149	nexthdr = *skb_mac_header(skb);
007f0211 HX	150	*skb_mac_header(skb) = IPPROTO_DSTOPTS;
3d126890	151
9c70220b	152	dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
3d126890 NT	153	dstopt->nexthdr = nexthdr;
	154
	155	hao = mip6_padn((char *)(dstopt + 1),
	156	calc_padlen(sizeof(*dstopt), 6));
	157
	158	hao->type = IPV6_TLV_HAO;
547b792c	159	BUILD_BUG_ON(sizeof(*hao) != 18);
3d126890	160	hao->length = sizeof(*hao) - 2;
3d126890 NT	161
	162	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	163
	164	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
b7c6538c	165	spin_lock_bh(&x->lock);
3d126890	166	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
b7c6538c	167	spin_unlock_bh(&x->lock);
3d126890	168
547b792c	169	WARN_ON(len != x->props.header_len);
3d126890 NT	170	dstopt->hdrlen = (x->props.header_len >> 3) - 1;
	171
	172	return 0;
	173	}
	174
3dd7669f	175	static inline int mip6_report_rl_allow(ktime_t stamp,
b71d1d42 ED	176	const struct in6_addr *dst,
b71d1d42 ED	177	const struct in6_addr *src, int iif)
70182ed2 MN	178	{
	179	int allow = 0;
	180
	181	spin_lock_bh(&mip6_report_rl.lock);
1f3a8e49	182	if (mip6_report_rl.stamp != stamp \|\|
70182ed2 MN	183	mip6_report_rl.iif != iif \|\|
	184	!ipv6_addr_equal(&mip6_report_rl.src, src) \|\|
	185	!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
3dd7669f	186	mip6_report_rl.stamp = stamp;
70182ed2	187	mip6_report_rl.iif = iif;
4e3fd7a0 AD	188	mip6_report_rl.src = *src;
4e3fd7a0 AD	189	mip6_report_rl.dst = *dst;
70182ed2 MN	190	allow = 1;
	191	}
	192	spin_unlock_bh(&mip6_report_rl.lock);
	193	return allow;
	194	}
	195
8f029de2 DM	196	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb,
8f029de2 DM	197	const struct flowi *fl)
70182ed2	198	{
db983c11	199	struct net *net = xs_net(x);
70182ed2	200	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
4c9483b2	201	const struct flowi6 *fl6 = &fl->u.ip6;
70182ed2 MN	202	struct ipv6_destopt_hao *hao = NULL;
	203	struct xfrm_selector sel;
	204	int offset;
3dd7669f	205	ktime_t stamp;
70182ed2 MN	206	int err = 0;
70182ed2 MN	207
4c9483b2	208	if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
1958b856	209	fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
01be8e5d MN	210	goto out;
01be8e5d MN	211
70182ed2 MN	212	if (likely(opt->dsthao)) {
	213	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	214	if (likely(offset >= 0))
d56f90a7 ACM	215	hao = (struct ipv6_destopt_hao *)
d56f90a7 ACM	216	(skb_network_header(skb) + offset);
70182ed2 MN	217	}
70182ed2 MN	218
3dd7669f	219	stamp = skb_get_ktime(skb);
70182ed2	220
3dd7669f	221	if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr,
0660e03f	222	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
70182ed2 MN	223	opt->iif))
	224	goto out;
	225
	226	memset(&sel, 0, sizeof(sel));
0660e03f	227	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
70182ed2 MN	228	sizeof(sel.daddr));
70182ed2 MN	229	sel.prefixlen_d = 128;
0660e03f	230	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
70182ed2 MN	231	sizeof(sel.saddr));
	232	sel.prefixlen_s = 128;
	233	sel.family = AF_INET6;
4c9483b2 DM	234	sel.proto = fl6->flowi6_proto;
4c9483b2 DM	235	sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
70182ed2	236	if (sel.dport)
e69a4adc	237	sel.dport_mask = htons(~0);
4c9483b2	238	sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
70182ed2	239	if (sel.sport)
e69a4adc	240	sel.sport_mask = htons(~0);
4c9483b2	241	sel.ifindex = fl6->flowi6_oif;
70182ed2	242
db983c11	243	err = km_report(net, IPPROTO_DSTOPTS, &sel,
70182ed2 MN	244	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	245
	246	out:
	247	return err;
	248	}
	249
3d126890 NT	250	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	251	u8 **nexthdr)
	252	{
	253	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	254	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	255	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	256	const unsigned char *nh = skb_network_header(skb);
29a3cad5 SH	257	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	258	skb_network_header(skb);
3d126890 NT	259	int found_rhdr = 0;
3d126890 NT	260
0660e03f	261	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	262
	263	while (offset + 1 <= packet_len) {
	264
	265	switch (**nexthdr) {
	266	case NEXTHDR_HOP:
	267	break;
	268	case NEXTHDR_ROUTING:
	269	found_rhdr = 1;
	270	break;
	271	case NEXTHDR_DEST:
	272	/*
	273	* HAO MUST NOT appear more than once.
	274	* XXX: It is better to try to find by the end of
	275	* XXX: packet if HAO exists.
	276	*/
	277	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
ba7a46f1	278	net_dbg_ratelimited("mip6: hao exists already, override\n");
3d126890 NT	279	return offset;
	280	}
	281
	282	if (found_rhdr)
	283	return offset;
	284
	285	break;
	286	default:
	287	return offset;
	288	}
	289
	290	offset += ipv6_optlen(exthdr);
	291	*nexthdr = &exthdr->nexthdr;
d56f90a7	292	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	293	}
	294
	295	return offset;
	296	}
	297
	298	static int mip6_destopt_init_state(struct xfrm_state *x)
	299	{
	300	if (x->id.spi) {
f3213831	301	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
3d126890 NT	302	return -EINVAL;
	303	}
	304	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	305	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	306	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
3d126890 NT	307	return -EINVAL;
	308	}
	309
	310	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	311	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	312	sizeof(struct ipv6_destopt_hao);
547b792c	313	WARN_ON(x->props.header_len != 24);
3d126890 NT	314
	315	return 0;
	316	}
	317
	318	/*
	319	* Do nothing about destroying since it has no specific operation for
	320	* destination options header unlike IPsec protocols.
	321	*/
	322	static void mip6_destopt_destroy(struct xfrm_state *x)
	323	{
	324	}
	325
cc24beca	326	static const struct xfrm_type mip6_destopt_type = {
3d126890 NT	327	.description = "MIP6DESTOPT",
3d126890 NT	328	.owner = THIS_MODULE,
cc24beca	329	.proto = IPPROTO_DSTOPTS,
f04e7e8d	330	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_LOCAL_COADDR,
3d126890 NT	331	.init_state = mip6_destopt_init_state,
	332	.destructor = mip6_destopt_destroy,
	333	.input = mip6_destopt_input,
	334	.output = mip6_destopt_output,
1ab1457c	335	.reject = mip6_destopt_reject,
3d126890	336	.hdr_offset = mip6_destopt_offset,
3d126890 NT	337	};
3d126890 NT	338
2c8d7ca0 NT	339	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
2c8d7ca0 NT	340	{
b71d1d42	341	const struct ipv6hdr *iph = ipv6_hdr(skb);
2c8d7ca0	342	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
0ebea8ef	343	int err = rt2->rt_hdr.nexthdr;
2c8d7ca0	344
0ebea8ef	345	spin_lock(&x->lock);
d9a9dc66	346	if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
2c8d7ca0	347	!ipv6_addr_any((struct in6_addr *)x->coaddr))
0ebea8ef HX	348	err = -ENOENT;
0ebea8ef HX	349	spin_unlock(&x->lock);
2c8d7ca0	350
0ebea8ef	351	return err;
2c8d7ca0 NT	352	}
	353
	354	/* Routing Header type 2 is inserted.
	355	* IP Header's dst address is replaced with Routing Header's Home Address.
	356	*/
	357	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	358	{
	359	struct ipv6hdr *iph;
	360	struct rt2_hdr *rt2;
	361	u8 nexthdr;
	362
7b277b1a	363	skb_push(skb, -skb_network_offset(skb));
007f0211	364	iph = ipv6_hdr(skb);
2c8d7ca0	365
007f0211 HX	366	nexthdr = *skb_mac_header(skb);
007f0211 HX	367	*skb_mac_header(skb) = IPPROTO_ROUTING;
2c8d7ca0	368
9c70220b	369	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
2c8d7ca0 NT	370	rt2->rt_hdr.nexthdr = nexthdr;
	371	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	372	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	373	rt2->rt_hdr.segments_left = 1;
	374	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	375
547b792c	376	WARN_ON(rt2->rt_hdr.hdrlen != 2);
2c8d7ca0 NT	377
2c8d7ca0 NT	378	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
b7c6538c	379	spin_lock_bh(&x->lock);
2c8d7ca0	380	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
b7c6538c	381	spin_unlock_bh(&x->lock);
2c8d7ca0 NT	382
	383	return 0;
	384	}
	385
	386	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	387	u8 **nexthdr)
	388	{
	389	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	390	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	391	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	392	const unsigned char *nh = skb_network_header(skb);
29a3cad5 SH	393	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	394	skb_network_header(skb);
2c8d7ca0 NT	395	int found_rhdr = 0;
2c8d7ca0 NT	396
0660e03f	397	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	398
	399	while (offset + 1 <= packet_len) {
	400
	401	switch (**nexthdr) {
	402	case NEXTHDR_HOP:
	403	break;
	404	case NEXTHDR_ROUTING:
	405	if (offset + 3 <= packet_len) {
	406	struct ipv6_rt_hdr *rt;
d56f90a7	407	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	408	if (rt->type != 0)
	409	return offset;
	410	}
	411	found_rhdr = 1;
	412	break;
	413	case NEXTHDR_DEST:
	414	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	415	return offset;
	416
	417	if (found_rhdr)
	418	return offset;
	419
	420	break;
	421	default:
	422	return offset;
	423	}
	424
	425	offset += ipv6_optlen(exthdr);
	426	*nexthdr = &exthdr->nexthdr;
d56f90a7	427	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	428	}
	429
	430	return offset;
	431	}
	432
	433	static int mip6_rthdr_init_state(struct xfrm_state *x)
	434	{
	435	if (x->id.spi) {
f3213831	436	pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
2c8d7ca0 NT	437	return -EINVAL;
	438	}
	439	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
f3213831 JP	440	pr_info("%s: state's mode is not %u: %u\n",
f3213831 JP	441	__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
2c8d7ca0 NT	442	return -EINVAL;
	443	}
	444
	445	x->props.header_len = sizeof(struct rt2_hdr);
	446
	447	return 0;
	448	}
	449
	450	/*
	451	* Do nothing about destroying since it has no specific operation for routing
	452	* header type 2 unlike IPsec protocols.
	453	*/
	454	static void mip6_rthdr_destroy(struct xfrm_state *x)
	455	{
	456	}
	457
cc24beca	458	static const struct xfrm_type mip6_rthdr_type = {
2c8d7ca0 NT	459	.description = "MIP6RT",
2c8d7ca0 NT	460	.owner = THIS_MODULE,
cc24beca	461	.proto = IPPROTO_ROUTING,
f04e7e8d	462	.flags = XFRM_TYPE_NON_FRAGMENT \| XFRM_TYPE_REMOTE_COADDR,
2c8d7ca0 NT	463	.init_state = mip6_rthdr_init_state,
	464	.destructor = mip6_rthdr_destroy,
	465	.input = mip6_rthdr_input,
	466	.output = mip6_rthdr_output,
	467	.hdr_offset = mip6_rthdr_offset,
2c8d7ca0 NT	468	};
2c8d7ca0 NT	469
59fbb3a6	470	static int __init mip6_init(void)
2c8d7ca0	471	{
f3213831	472	pr_info("Mobile IPv6\n");
2c8d7ca0	473
3d126890	474	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
f3213831	475	pr_info("%s: can't add xfrm type(destopt)\n", __func__);
3d126890 NT	476	goto mip6_destopt_xfrm_fail;
3d126890 NT	477	}
2c8d7ca0	478	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
f3213831	479	pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
2c8d7ca0 NT	480	goto mip6_rthdr_xfrm_fail;
2c8d7ca0 NT	481	}
59fbb3a6	482	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
f3213831	483	pr_info("%s: can't add rawv6 mh filter\n", __func__);
59fbb3a6 MN	484	goto mip6_rawv6_mh_fail;
	485	}
	486
	487
2c8d7ca0 NT	488	return 0;
2c8d7ca0 NT	489
59fbb3a6 MN	490	mip6_rawv6_mh_fail:
59fbb3a6 MN	491	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
2c8d7ca0	492	mip6_rthdr_xfrm_fail:
3d126890 NT	493	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
3d126890 NT	494	mip6_destopt_xfrm_fail:
2c8d7ca0 NT	495	return -EAGAIN;
	496	}
	497
59fbb3a6	498	static void __exit mip6_fini(void)
2c8d7ca0	499	{
59fbb3a6	500	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
f3213831	501	pr_info("%s: can't remove rawv6 mh filter\n", __func__);
4f518e80 FW	502	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
4f518e80 FW	503	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
2c8d7ca0	504	}
59fbb3a6 MN	505
	506	module_init(mip6_init);
	507	module_exit(mip6_fini);
	508
	509	MODULE_LICENSE("GPL");
d3d6dd3a MN	510	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
d3d6dd3a MN	511	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);