linux/net/ipv6/xfrm6_tunnel.c
Masahide NAKAMURA 7e49e6de30 [XFRM]: Add XFRM_MODE_xxx for future use.
Transformation mode is used as either IPsec transport or tunnel.
It is required to add two more items, route optimization and inbound trigger
for Mobile IPv6.
Based on MIPL2 kernel patch.

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

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>
2006-09-22 15:05:15 -07:00

369 lines
8.6 KiB
C

/*
* Copyright (C)2003,2004 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 Mitsuru KANDA <mk@linux-ipv6.org>
* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
*
* Based on net/ipv4/xfrm4_tunnel.c
*
*/
#include <linux/module.h>
#include <linux/xfrm.h>
#include <linux/list.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipv6.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>
/*
* xfrm_tunnel_spi things are for allocating unique id ("spi")
* per xfrm_address_t.
*/
struct xfrm6_tunnel_spi {
struct hlist_node list_byaddr;
struct hlist_node list_byspi;
xfrm_address_t addr;
u32 spi;
atomic_t refcnt;
};
static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock);
static u32 xfrm6_tunnel_spi;
#define XFRM6_TUNNEL_SPI_MIN 1
#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly;
#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
static unsigned inline xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
{
unsigned h;
h = addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3];
h ^= h >> 16;
h ^= h >> 8;
h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
return h;
}
static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi)
{
return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
}
static int xfrm6_tunnel_spi_init(void)
{
int i;
xfrm6_tunnel_spi = 0;
xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
sizeof(struct xfrm6_tunnel_spi),
0, SLAB_HWCACHE_ALIGN,
NULL, NULL);
if (!xfrm6_tunnel_spi_kmem)
return -ENOMEM;
for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]);
for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]);
return 0;
}
static void xfrm6_tunnel_spi_fini(void)
{
int i;
for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) {
if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i]))
return;
}
for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) {
if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i]))
return;
}
kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
xfrm6_tunnel_spi_kmem = NULL;
}
static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
struct hlist_node *pos;
hlist_for_each_entry(x6spi, pos,
&xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
list_byaddr) {
if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
return x6spi;
}
return NULL;
}
u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
read_lock_bh(&xfrm6_tunnel_spi_lock);
x6spi = __xfrm6_tunnel_spi_lookup(saddr);
spi = x6spi ? x6spi->spi : 0;
read_unlock_bh(&xfrm6_tunnel_spi_lock);
return spi;
}
EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
u32 spi;
struct xfrm6_tunnel_spi *x6spi;
struct hlist_node *pos;
unsigned index;
if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN ||
xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX)
xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN;
else
xfrm6_tunnel_spi++;
for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
index = xfrm6_tunnel_spi_hash_byspi(spi);
hlist_for_each_entry(x6spi, pos,
&xfrm6_tunnel_spi_byspi[index],
list_byspi) {
if (x6spi->spi == spi)
goto try_next_1;
}
xfrm6_tunnel_spi = spi;
goto alloc_spi;
try_next_1:;
}
for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
index = xfrm6_tunnel_spi_hash_byspi(spi);
hlist_for_each_entry(x6spi, pos,
&xfrm6_tunnel_spi_byspi[index],
list_byspi) {
if (x6spi->spi == spi)
goto try_next_2;
}
xfrm6_tunnel_spi = spi;
goto alloc_spi;
try_next_2:;
}
spi = 0;
goto out;
alloc_spi:
x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC);
if (!x6spi)
goto out;
memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
x6spi->spi = spi;
atomic_set(&x6spi->refcnt, 1);
hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);
index = xfrm6_tunnel_spi_hash_byaddr(saddr);
hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
out:
return spi;
}
u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
write_lock_bh(&xfrm6_tunnel_spi_lock);
x6spi = __xfrm6_tunnel_spi_lookup(saddr);
if (x6spi) {
atomic_inc(&x6spi->refcnt);
spi = x6spi->spi;
} else
spi = __xfrm6_tunnel_alloc_spi(saddr);
write_unlock_bh(&xfrm6_tunnel_spi_lock);
return spi;
}
EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
struct hlist_node *pos, *n;
write_lock_bh(&xfrm6_tunnel_spi_lock);
hlist_for_each_entry_safe(x6spi, pos, n,
&xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
list_byaddr)
{
if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
if (atomic_dec_and_test(&x6spi->refcnt)) {
hlist_del(&x6spi->list_byaddr);
hlist_del(&x6spi->list_byspi);
kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi);
break;
}
}
}
write_unlock_bh(&xfrm6_tunnel_spi_lock);
}
EXPORT_SYMBOL(xfrm6_tunnel_free_spi);
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *top_iph;
top_iph = (struct ipv6hdr *)skb->data;
top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
return 0;
}
static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
return 0;
}
static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
struct ipv6hdr *iph = skb->nh.ipv6h;
u32 spi;
spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
return xfrm6_rcv_spi(skb, spi);
}
static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __u32 info)
{
/* xfrm6_tunnel native err handling */
switch (type) {
case ICMPV6_DEST_UNREACH:
switch (code) {
case ICMPV6_NOROUTE:
case ICMPV6_ADM_PROHIBITED:
case ICMPV6_NOT_NEIGHBOUR:
case ICMPV6_ADDR_UNREACH:
case ICMPV6_PORT_UNREACH:
default:
break;
}
break;
case ICMPV6_PKT_TOOBIG:
break;
case ICMPV6_TIME_EXCEED:
switch (code) {
case ICMPV6_EXC_HOPLIMIT:
break;
case ICMPV6_EXC_FRAGTIME:
default:
break;
}
break;
case ICMPV6_PARAMPROB:
switch (code) {
case ICMPV6_HDR_FIELD: break;
case ICMPV6_UNK_NEXTHDR: break;
case ICMPV6_UNK_OPTION: break;
}
break;
default:
break;
}
return 0;
}
static int xfrm6_tunnel_init_state(struct xfrm_state *x)
{
if (x->props.mode != XFRM_MODE_TUNNEL)
return -EINVAL;
if (x->encap)
return -EINVAL;
x->props.header_len = sizeof(struct ipv6hdr);
return 0;
}
static void xfrm6_tunnel_destroy(struct xfrm_state *x)
{
xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
}
static struct xfrm_type xfrm6_tunnel_type = {
.description = "IP6IP6",
.owner = THIS_MODULE,
.proto = IPPROTO_IPV6,
.init_state = xfrm6_tunnel_init_state,
.destructor = xfrm6_tunnel_destroy,
.input = xfrm6_tunnel_input,
.output = xfrm6_tunnel_output,
};
static struct xfrm6_tunnel xfrm6_tunnel_handler = {
.handler = xfrm6_tunnel_rcv,
.err_handler = xfrm6_tunnel_err,
.priority = 2,
};
static int __init xfrm6_tunnel_init(void)
{
if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0)
return -EAGAIN;
if (xfrm6_tunnel_register(&xfrm6_tunnel_handler)) {
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
return -EAGAIN;
}
if (xfrm6_tunnel_spi_init() < 0) {
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler);
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
return -EAGAIN;
}
return 0;
}
static void __exit xfrm6_tunnel_fini(void)
{
xfrm6_tunnel_spi_fini();
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler);
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
}
module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_LICENSE("GPL");