[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: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Noriaki TAKAMIYA 2006-08-23 20:32:34 -07:00 committed by David S. Miller
parent 2c8d7ca0f7
commit 3d126890dd
2 changed files with 170 additions and 0 deletions

View File

@ -25,6 +25,9 @@
#ifndef _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 void mip6_fini(void);

View File

@ -35,6 +35,165 @@ 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 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)
{
struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
@ -164,6 +323,10 @@ 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;
@ -171,6 +334,8 @@ int __init mip6_init(void)
return 0;
mip6_rthdr_xfrm_fail:
xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
mip6_destopt_xfrm_fail:
return -EAGAIN;
}
@ -178,4 +343,6 @@ void __exit mip6_fini(void)
{
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__);
}