[GitHub/MotorolaMobilityLLC/kernel-slsi.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 xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr)
{
	return x->coaddr;
}

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] = MIP6_OPT_PAD_1;
	} else if (padlen > 1) {
		data[0] = MIP6_OPT_PAD_N;
		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, int code, int pos)
{
	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
}

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;

	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
		return -ENOENT;

	return destopt->nexthdr;
}

/* 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;

	iph = (struct ipv6hdr *)skb->data;
	iph->payload_len = htons(skb->len - sizeof(*iph));

	nexthdr = *skb_network_header(skb);
	*skb_network_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;
	hao->length = sizeof(*hao) - 2;
	BUG_TRAP(hao->length == 16);

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

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

	BUG_TRAP(len == x->props.header_len);
	dstopt->hdrlen = (x->props.header_len >> 3) - 1;

	return 0;
}

static inline int mip6_report_rl_allow(struct timeval *stamp,
				       struct in6_addr *dst,
				       struct in6_addr *src, int iif)
{
	int allow = 0;

	spin_lock_bh(&mip6_report_rl.lock);
	if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
	    mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
	    mip6_report_rl.iif != iif ||
	    !ipv6_addr_equal(&mip6_report_rl.src, src) ||
	    !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
		mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
		mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
		mip6_report_rl.iif = iif;
		ipv6_addr_copy(&mip6_report_rl.src, src);
		ipv6_addr_copy(&mip6_report_rl.dst, dst);
		allow = 1;
	}
	spin_unlock_bh(&mip6_report_rl.lock);
	return allow;
}

static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl)
{
	struct 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(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", __FUNCTION__,
		       x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
		       __FUNCTION__, 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);
	BUG_TRAP(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 struct xfrm_type mip6_destopt_type =
{
	.description	= "MIP6DESTOPT",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_DSTOPTS,
	.flags		= XFRM_TYPE_NON_FRAGMENT,
	.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,
	.local_addr	= mip6_xfrm_addr,
};

static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
{
	struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;

	if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
	    !ipv6_addr_any((struct in6_addr *)x->coaddr))
		return -ENOENT;

	return rt2->rt_hdr.nexthdr;
}

/* 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;

	iph = (struct ipv6hdr *)skb->data;
	iph->payload_len = htons(skb->len - sizeof(*iph));

	nexthdr = *skb_network_header(skb);
	*skb_network_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));

	BUG_TRAP(rt2->rt_hdr.hdrlen == 2);

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

	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", __FUNCTION__,
		       x->id.spi);
		return -EINVAL;
	}
	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
		printk(KERN_INFO "%s: state's mode is not %u: %u\n",
		       __FUNCTION__, 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 struct xfrm_type mip6_rthdr_type =
{
	.description	= "MIP6RT",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_ROUTING,
	.flags		= XFRM_TYPE_NON_FRAGMENT,
	.init_state	= mip6_rthdr_init_state,
	.destructor	= mip6_rthdr_destroy,
	.input		= mip6_rthdr_input,
	.output		= mip6_rthdr_output,
	.hdr_offset	= mip6_rthdr_offset,
	.remote_addr	= mip6_xfrm_addr,
};

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", __FUNCTION__);
		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", __FUNCTION__);
		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", __FUNCTION__);
		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", __FUNCTION__);
	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
		printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
		printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
}

module_init(mip6_init);
module_exit(mip6_fini);

MODULE_LICENSE("GPL");
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
	37	static xfrm_address_t mip6_xfrm_addr(struct xfrm_state x, xfrm_address_t *addr)
	38	{
	39	return x->coaddr;
	40	}
	41
3d126890 NT	42	static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
	43	{
	44	return (n - len + 16) & 0x7;
	45	}
	46
	47	static inline void mip6_padn(__u8 data, __u8 padlen)
	48	{
	49	if (!data)
	50	return NULL;
	51	if (padlen == 1) {
	52	data[0] = MIP6_OPT_PAD_1;
	53	} else if (padlen > 1) {
	54	data[0] = MIP6_OPT_PAD_N;
	55	data[1] = padlen - 2;
	56	if (padlen > 2)
	57	memset(data+2, 0, data[1]);
	58	}
	59	return data + padlen;
	60	}
	61
7be96f76 MN	62	static inline void mip6_param_prob(struct sk_buff *skb, int code, int pos)
	63	{
	64	icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
	65	}
	66
	67	static int mip6_mh_len(int type)
	68	{
	69	int len = 0;
	70
	71	switch (type) {
	72	case IP6_MH_TYPE_BRR:
	73	len = 0;
	74	break;
	75	case IP6_MH_TYPE_HOTI:
	76	case IP6_MH_TYPE_COTI:
	77	case IP6_MH_TYPE_BU:
	78	case IP6_MH_TYPE_BACK:
	79	len = 1;
	80	break;
	81	case IP6_MH_TYPE_HOT:
	82	case IP6_MH_TYPE_COT:
	83	case IP6_MH_TYPE_BERROR:
	84	len = 2;
	85	break;
	86	}
	87	return len;
	88	}
	89
59fbb3a6	90	static int mip6_mh_filter(struct sock sk, struct sk_buff skb)
7be96f76 MN	91	{
7be96f76 MN	92	struct ip6_mh *mh;
7be96f76	93
ea2ae17d ACM	94	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) \|\|
ea2ae17d ACM	95	!pskb_may_pull(skb, (skb_transport_offset(skb) +
9c70220b	96	((skb_transport_header(skb)[1] + 1) << 3))))
7be96f76 MN	97	return -1;
7be96f76 MN	98
9c70220b	99	mh = (struct ip6_mh *)skb_transport_header(skb);
7be96f76 MN	100
	101	if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
	102	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
	103	mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
d56f90a7 ACM	104	mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
d56f90a7 ACM	105	skb_network_header(skb)));
7be96f76 MN	106	return -1;
7be96f76 MN	107	}
7be96f76 MN	108
	109	if (mh->ip6mh_proto != IPPROTO_NONE) {
	110	LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
	111	mh->ip6mh_proto);
d56f90a7 ACM	112	mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
d56f90a7 ACM	113	skb_network_header(skb)));
7be96f76 MN	114	return -1;
	115	}
	116
	117	return 0;
	118	}
	119
70182ed2 MN	120	struct mip6_report_rate_limiter {
	121	spinlock_t lock;
	122	struct timeval stamp;
	123	int iif;
	124	struct in6_addr src;
	125	struct in6_addr dst;
	126	};
	127
	128	static struct mip6_report_rate_limiter mip6_report_rl = {
4ef8d0ae	129	.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
70182ed2 MN	130	};
70182ed2 MN	131
3d126890 NT	132	static int mip6_destopt_input(struct xfrm_state x, struct sk_buff skb)
3d126890 NT	133	{
0660e03f	134	struct ipv6hdr *iph = ipv6_hdr(skb);
3d126890 NT	135	struct ipv6_destopt_hdr destopt = (struct ipv6_destopt_hdr )skb->data;
	136
	137	if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
	138	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	139	return -ENOENT;
	140
	141	return destopt->nexthdr;
	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
	156	iph = (struct ipv6hdr *)skb->data;
	157	iph->payload_len = htons(skb->len - sizeof(*iph));
	158
d56f90a7 ACM	159	nexthdr = *skb_network_header(skb);
d56f90a7 ACM	160	*skb_network_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;
	169	hao->length = sizeof(*hao) - 2;
	170	BUG_TRAP(hao->length == 16);
	171
	172	len = ((char )hao - (char )dstopt) + sizeof(*hao);
	173
	174	memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
	175	memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
	176
	177	BUG_TRAP(len == x->props.header_len);
	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
	206	static int mip6_destopt_reject(struct xfrm_state x, struct sk_buff skb, struct flowi *fl)
	207	{
	208	struct inet6_skb_parm opt = (struct inet6_skb_parm )skb->cb;
	209	struct ipv6_destopt_hao *hao = NULL;
	210	struct xfrm_selector sel;
	211	int offset;
	212	struct timeval stamp;
	213	int err = 0;
	214
e731c248 YH	215	if (unlikely(fl->proto == IPPROTO_MH &&
e731c248 YH	216	fl->fl_mh_type <= IP6_MH_TYPE_MAX))
01be8e5d MN	217	goto out;
01be8e5d MN	218
70182ed2 MN	219	if (likely(opt->dsthao)) {
	220	offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
	221	if (likely(offset >= 0))
d56f90a7 ACM	222	hao = (struct ipv6_destopt_hao *)
d56f90a7 ACM	223	(skb_network_header(skb) + offset);
70182ed2 MN	224	}
	225
	226	skb_get_timestamp(skb, &stamp);
	227
0660e03f ACM	228	if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
0660e03f ACM	229	hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
70182ed2 MN	230	opt->iif))
	231	goto out;
	232
	233	memset(&sel, 0, sizeof(sel));
0660e03f	234	memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
70182ed2 MN	235	sizeof(sel.daddr));
70182ed2 MN	236	sel.prefixlen_d = 128;
0660e03f	237	memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
70182ed2 MN	238	sizeof(sel.saddr));
	239	sel.prefixlen_s = 128;
	240	sel.family = AF_INET6;
	241	sel.proto = fl->proto;
	242	sel.dport = xfrm_flowi_dport(fl);
	243	if (sel.dport)
e69a4adc	244	sel.dport_mask = htons(~0);
70182ed2 MN	245	sel.sport = xfrm_flowi_sport(fl);
70182ed2 MN	246	if (sel.sport)
e69a4adc	247	sel.sport_mask = htons(~0);
70182ed2 MN	248	sel.ifindex = fl->oif;
	249
	250	err = km_report(IPPROTO_DSTOPTS, &sel,
	251	(hao ? (xfrm_address_t *)&hao->addr : NULL));
	252
	253	out:
	254	return err;
	255	}
	256
3d126890 NT	257	static int mip6_destopt_offset(struct xfrm_state x, struct sk_buff skb,
	258	u8 **nexthdr)
	259	{
	260	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	261	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	262	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	263	const unsigned char *nh = skb_network_header(skb);
27a884dc	264	unsigned int packet_len = skb->tail - skb->network_header;
3d126890 NT	265	int found_rhdr = 0;
3d126890 NT	266
0660e03f	267	*nexthdr = &ipv6_hdr(skb)->nexthdr;
3d126890 NT	268
	269	while (offset + 1 <= packet_len) {
	270
	271	switch (**nexthdr) {
	272	case NEXTHDR_HOP:
	273	break;
	274	case NEXTHDR_ROUTING:
	275	found_rhdr = 1;
	276	break;
	277	case NEXTHDR_DEST:
	278	/*
	279	* HAO MUST NOT appear more than once.
	280	* XXX: It is better to try to find by the end of
	281	* XXX: packet if HAO exists.
	282	*/
	283	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
	284	LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
	285	return offset;
	286	}
	287
	288	if (found_rhdr)
	289	return offset;
	290
	291	break;
	292	default:
	293	return offset;
	294	}
	295
	296	offset += ipv6_optlen(exthdr);
	297	*nexthdr = &exthdr->nexthdr;
d56f90a7	298	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
3d126890 NT	299	}
	300
	301	return offset;
	302	}
	303
	304	static int mip6_destopt_init_state(struct xfrm_state *x)
	305	{
	306	if (x->id.spi) {
	307	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	308	x->id.spi);
	309	return -EINVAL;
	310	}
	311	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	312	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	313	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	314	return -EINVAL;
	315	}
	316
	317	x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
	318	calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
	319	sizeof(struct ipv6_destopt_hao);
	320	BUG_TRAP(x->props.header_len == 24);
	321
	322	return 0;
	323	}
	324
	325	/*
	326	* Do nothing about destroying since it has no specific operation for
	327	* destination options header unlike IPsec protocols.
	328	*/
	329	static void mip6_destopt_destroy(struct xfrm_state *x)
	330	{
	331	}
	332
	333	static struct xfrm_type mip6_destopt_type =
	334	{
	335	.description = "MIP6DESTOPT",
	336	.owner = THIS_MODULE,
	337	.proto = IPPROTO_DSTOPTS,
	338	.flags = XFRM_TYPE_NON_FRAGMENT,
	339	.init_state = mip6_destopt_init_state,
	340	.destructor = mip6_destopt_destroy,
	341	.input = mip6_destopt_input,
	342	.output = mip6_destopt_output,
1ab1457c	343	.reject = mip6_destopt_reject,
3d126890 NT	344	.hdr_offset = mip6_destopt_offset,
	345	.local_addr = mip6_xfrm_addr,
	346	};
	347
2c8d7ca0 NT	348	static int mip6_rthdr_input(struct xfrm_state x, struct sk_buff skb)
	349	{
	350	struct rt2_hdr rt2 = (struct rt2_hdr )skb->data;
	351
	352	if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
	353	!ipv6_addr_any((struct in6_addr *)x->coaddr))
	354	return -ENOENT;
	355
	356	return rt2->rt_hdr.nexthdr;
	357	}
	358
	359	/* Routing Header type 2 is inserted.
	360	* IP Header's dst address is replaced with Routing Header's Home Address.
	361	*/
	362	static int mip6_rthdr_output(struct xfrm_state x, struct sk_buff skb)
	363	{
	364	struct ipv6hdr *iph;
	365	struct rt2_hdr *rt2;
	366	u8 nexthdr;
	367
	368	iph = (struct ipv6hdr *)skb->data;
	369	iph->payload_len = htons(skb->len - sizeof(*iph));
	370
d56f90a7 ACM	371	nexthdr = *skb_network_header(skb);
d56f90a7 ACM	372	*skb_network_header(skb) = IPPROTO_ROUTING;
2c8d7ca0	373
9c70220b	374	rt2 = (struct rt2_hdr *)skb_transport_header(skb);
2c8d7ca0 NT	375	rt2->rt_hdr.nexthdr = nexthdr;
	376	rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
	377	rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
	378	rt2->rt_hdr.segments_left = 1;
	379	memset(&rt2->reserved, 0, sizeof(rt2->reserved));
	380
	381	BUG_TRAP(rt2->rt_hdr.hdrlen == 2);
	382
	383	memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
	384	memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
	385
	386	return 0;
	387	}
	388
	389	static int mip6_rthdr_offset(struct xfrm_state x, struct sk_buff skb,
	390	u8 **nexthdr)
	391	{
	392	u16 offset = sizeof(struct ipv6hdr);
0660e03f ACM	393	struct ipv6_opt_hdr *exthdr =
0660e03f ACM	394	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
d56f90a7	395	const unsigned char *nh = skb_network_header(skb);
27a884dc	396	unsigned int packet_len = skb->tail - skb->network_header;
2c8d7ca0 NT	397	int found_rhdr = 0;
2c8d7ca0 NT	398
0660e03f	399	*nexthdr = &ipv6_hdr(skb)->nexthdr;
2c8d7ca0 NT	400
	401	while (offset + 1 <= packet_len) {
	402
	403	switch (**nexthdr) {
	404	case NEXTHDR_HOP:
	405	break;
	406	case NEXTHDR_ROUTING:
	407	if (offset + 3 <= packet_len) {
	408	struct ipv6_rt_hdr *rt;
d56f90a7	409	rt = (struct ipv6_rt_hdr *)(nh + offset);
2c8d7ca0 NT	410	if (rt->type != 0)
	411	return offset;
	412	}
	413	found_rhdr = 1;
	414	break;
	415	case NEXTHDR_DEST:
	416	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	417	return offset;
	418
	419	if (found_rhdr)
	420	return offset;
	421
	422	break;
	423	default:
	424	return offset;
	425	}
	426
	427	offset += ipv6_optlen(exthdr);
	428	*nexthdr = &exthdr->nexthdr;
d56f90a7	429	exthdr = (struct ipv6_opt_hdr *)(nh + offset);
2c8d7ca0 NT	430	}
	431
	432	return offset;
	433	}
	434
	435	static int mip6_rthdr_init_state(struct xfrm_state *x)
	436	{
	437	if (x->id.spi) {
	438	printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
	439	x->id.spi);
	440	return -EINVAL;
	441	}
	442	if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
	443	printk(KERN_INFO "%s: state's mode is not %u: %u\n",
	444	__FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
	445	return -EINVAL;
	446	}
	447
	448	x->props.header_len = sizeof(struct rt2_hdr);
	449
	450	return 0;
	451	}
	452
	453	/*
	454	* Do nothing about destroying since it has no specific operation for routing
	455	* header type 2 unlike IPsec protocols.
	456	*/
	457	static void mip6_rthdr_destroy(struct xfrm_state *x)
	458	{
	459	}
	460
	461	static struct xfrm_type mip6_rthdr_type =
	462	{
	463	.description = "MIP6RT",
	464	.owner = THIS_MODULE,
	465	.proto = IPPROTO_ROUTING,
	466	.flags = XFRM_TYPE_NON_FRAGMENT,
	467	.init_state = mip6_rthdr_init_state,
	468	.destructor = mip6_rthdr_destroy,
	469	.input = mip6_rthdr_input,
	470	.output = mip6_rthdr_output,
	471	.hdr_offset = mip6_rthdr_offset,
	472	.remote_addr = mip6_xfrm_addr,
	473	};
	474
59fbb3a6	475	static int __init mip6_init(void)
2c8d7ca0 NT	476	{
	477	printk(KERN_INFO "Mobile IPv6\n");
	478
3d126890 NT	479	if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
	480	printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
	481	goto mip6_destopt_xfrm_fail;
	482	}
2c8d7ca0 NT	483	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
	484	printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
	485	goto mip6_rthdr_xfrm_fail;
	486	}
59fbb3a6 MN	487	if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
	488	printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __FUNCTION__);
	489	goto mip6_rawv6_mh_fail;
	490	}
	491
	492
2c8d7ca0 NT	493	return 0;
2c8d7ca0 NT	494
59fbb3a6 MN	495	mip6_rawv6_mh_fail:
59fbb3a6 MN	496	xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
2c8d7ca0	497	mip6_rthdr_xfrm_fail:
3d126890 NT	498	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
3d126890 NT	499	mip6_destopt_xfrm_fail:
2c8d7ca0 NT	500	return -EAGAIN;
	501	}
	502
59fbb3a6	503	static void __exit mip6_fini(void)
2c8d7ca0	504	{
59fbb3a6 MN	505	if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
59fbb3a6 MN	506	printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __FUNCTION__);
2c8d7ca0 NT	507	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
2c8d7ca0 NT	508	printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
3d126890 NT	509	if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
3d126890 NT	510	printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
2c8d7ca0	511	}
59fbb3a6 MN	512
	513	module_init(mip6_init);
	514	module_exit(mip6_fini);
	515
	516	MODULE_LICENSE("GPL");