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Commit 3d126890 authored by Noriaki TAKAMIYA's avatar Noriaki TAKAMIYA Committed by David S. Miller
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[IPV6] MIP6: Add destination options header transformation. 



Add destination options header transformation for Mobile IPv6.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>

Signed-off-by: default avatarNoriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: default avatarMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2c8d7ca0

include/net/mip6.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -25,6 +25,9 @@ 
#ifndef _NET_MIP6_H

#ifndef _NET_MIP6_H

#define _NET_MIP6_H

#define _NET_MIP6_H





#define MIP6_OPT_PAD_1	0

#define MIP6_OPT_PAD_N	1



extern int mip6_init(void);

extern int mip6_init(void);

extern void mip6_fini(void);

extern void mip6_fini(void);

net/ipv6/mip6.c

+167 −0
Original line number Original line Diff line number Diff line
@@ -35,6 +35,165 @@ static xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr 
	return x->coaddr;

	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 int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)

{

	struct ipv6hdr *iph = skb->nh.ipv6h;

	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->nh.raw;

	*skb->nh.raw = IPPROTO_DSTOPTS;



	dstopt = (struct ipv6_destopt_hdr *)skb->h.raw;

	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 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*)(skb->nh.ipv6h + 1);

	unsigned int packet_len = skb->tail - skb->nh.raw;

	int found_rhdr = 0;



	*nexthdr = &skb->nh.ipv6h->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*)(skb->nh.raw + 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,

	.hdr_offset	= mip6_destopt_offset,

	.local_addr	= mip6_xfrm_addr,

};



static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)

static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)

{

{

	struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;

	struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
@@ -164,6 +323,10 @@ int __init mip6_init(void) 
{

{

	printk(KERN_INFO "Mobile IPv6\n");

	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) {

	if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {

		printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);

		printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);

		goto mip6_rthdr_xfrm_fail;

		goto mip6_rthdr_xfrm_fail;
@@ -171,6 +334,8 @@ int __init mip6_init(void) 
	return 0;

	return 0;





 mip6_rthdr_xfrm_fail:

 mip6_rthdr_xfrm_fail:

	xfrm_unregister_type(&mip6_destopt_type, AF_INET6);

 mip6_destopt_xfrm_fail:

	return -EAGAIN;

	return -EAGAIN;

}

}
@@ -178,4 +343,6 @@ void __exit mip6_fini(void) 
{

{

	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)

	if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)

		printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);

		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__);

}
 
}