linux/net/ipv6/xfrm6_tunnel.c

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/*
* 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/rculist.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;
struct rcu_head rcu_head;
};
static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);
static u32 xfrm6_tunnel_spi;
#define XFRM6_TUNNEL_SPI_MIN 1
#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
static struct kmem_cache *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 inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
{
unsigned h;
h = (__force u32)(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 inline unsigned 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);
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;
}
rcu_barrier();
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_rcu(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;
}
__be32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
rcu_read_lock_bh();
x6spi = __xfrm6_tunnel_spi_lookup(saddr);
spi = x6spi ? x6spi->spi : 0;
rcu_read_unlock_bh();
return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
static int __xfrm6_tunnel_spi_check(u32 spi)
{
struct xfrm6_tunnel_spi *x6spi;
int index = xfrm6_tunnel_spi_hash_byspi(spi);
struct hlist_node *pos;
hlist_for_each_entry(x6spi, pos,
&xfrm6_tunnel_spi_byspi[index],
list_byspi) {
if (x6spi->spi == spi)
return -1;
}
return index;
}
static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
u32 spi;
struct xfrm6_tunnel_spi *x6spi;
int 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_check(spi);
if (index >= 0)
goto alloc_spi;
}
for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
index = __xfrm6_tunnel_spi_check(spi);
if (index >= 0)
goto alloc_spi;
}
spi = 0;
goto out;
alloc_spi:
xfrm6_tunnel_spi = spi;
x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
if (!x6spi)
goto out;
INIT_RCU_HEAD(&x6spi->rcu_head);
memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
x6spi->spi = spi;
atomic_set(&x6spi->refcnt, 1);
hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);
index = xfrm6_tunnel_spi_hash_byaddr(saddr);
hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
out:
return spi;
}
__be32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
spin_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);
spin_unlock_bh(&xfrm6_tunnel_spi_lock);
return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
static void x6spi_destroy_rcu(struct rcu_head *head)
{
kmem_cache_free(xfrm6_tunnel_spi_kmem,
container_of(head, struct xfrm6_tunnel_spi, rcu_head));
}
void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
struct hlist_node *pos, *n;
spin_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_rcu(&x6spi->list_byaddr);
hlist_del_rcu(&x6spi->list_byspi);
call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
break;
}
}
}
spin_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)
{
skb_push(skb, -skb_network_offset(skb));
return 0;
}
static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
return skb_network_header(skb)[IP6CB(skb)->nhoff];
}
[INET]: Introduce tunnel4/tunnel6 Basically this patch moves the generic tunnel protocol stuff out of xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c and tunnel6 respectively. The reason for this is that the problem that Hugo uncovered is only the tip of the iceberg. The real problem is that when we removed the dependency of ipip on xfrm4_tunnel we didn't really consider the module case at all. For instance, as it is it's possible to build both ipip and xfrm4_tunnel as modules and if the latter is loaded then ipip simply won't load. After considering the alternatives I've decided that the best way out of this is to restore the dependency of ipip on the non-xfrm-specific part of xfrm4_tunnel. This is acceptable IMHO because the intention of the removal was really to be able to use ipip without the xfrm subsystem. This is still preserved by this patch. So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles the arbitration between the two. The order of processing is determined by a simple integer which ensures that ipip gets processed before xfrm4_tunnel. The situation for ICMP handling is a little bit more complicated since we may not have enough information to determine who it's for. It's not a big deal at the moment since the xfrm ICMP handlers are basically no-ops. In future we can deal with this when we look at ICMP caching in general. The user-visible change to this is the removal of the TUNNEL Kconfig prompts. This makes sense because it can only be used through IPCOMP as it stands. The addition of the new modules shouldn't introduce any problems since module dependency will cause them to be loaded. Oh and I also turned some unnecessary pskb's in IPv6 related to this patch to skb's. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 09:12:13 +00:00
static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
struct ipv6hdr *iph = ipv6_hdr(skb);
__be32 spi;
spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
}
[INET]: Introduce tunnel4/tunnel6 Basically this patch moves the generic tunnel protocol stuff out of xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c and tunnel6 respectively. The reason for this is that the problem that Hugo uncovered is only the tip of the iceberg. The real problem is that when we removed the dependency of ipip on xfrm4_tunnel we didn't really consider the module case at all. For instance, as it is it's possible to build both ipip and xfrm4_tunnel as modules and if the latter is loaded then ipip simply won't load. After considering the alternatives I've decided that the best way out of this is to restore the dependency of ipip on the non-xfrm-specific part of xfrm4_tunnel. This is acceptable IMHO because the intention of the removal was really to be able to use ipip without the xfrm subsystem. This is still preserved by this patch. So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles the arbitration between the two. The order of processing is determined by a simple integer which ensures that ipip gets processed before xfrm4_tunnel. The situation for ICMP handling is a little bit more complicated since we may not have enough information to determine who it's for. It's not a big deal at the moment since the xfrm ICMP handlers are basically no-ops. In future we can deal with this when we look at ICMP caching in general. The user-visible change to this is the removal of the TUNNEL Kconfig prompts. This makes sense because it can only be used through IPCOMP as it stands. The addition of the new modules shouldn't introduce any problems since module dependency will cause them to be loaded. Oh and I also turned some unnecessary pskb's in IPv6 related to this patch to skb's. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 09:12:13 +00:00
static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 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;
}
[INET]: Introduce tunnel4/tunnel6 Basically this patch moves the generic tunnel protocol stuff out of xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c and tunnel6 respectively. The reason for this is that the problem that Hugo uncovered is only the tip of the iceberg. The real problem is that when we removed the dependency of ipip on xfrm4_tunnel we didn't really consider the module case at all. For instance, as it is it's possible to build both ipip and xfrm4_tunnel as modules and if the latter is loaded then ipip simply won't load. After considering the alternatives I've decided that the best way out of this is to restore the dependency of ipip on the non-xfrm-specific part of xfrm4_tunnel. This is acceptable IMHO because the intention of the removal was really to be able to use ipip without the xfrm subsystem. This is still preserved by this patch. So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles the arbitration between the two. The order of processing is determined by a simple integer which ensures that ipip gets processed before xfrm4_tunnel. The situation for ICMP handling is a little bit more complicated since we may not have enough information to determine who it's for. It's not a big deal at the moment since the xfrm ICMP handlers are basically no-ops. In future we can deal with this when we look at ICMP caching in general. The user-visible change to this is the removal of the TUNNEL Kconfig prompts. This makes sense because it can only be used through IPCOMP as it stands. The addition of the new modules shouldn't introduce any problems since module dependency will cause them to be loaded. Oh and I also turned some unnecessary pskb's in IPv6 related to this patch to skb's. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 09:12:13 +00:00
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 const 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,
};
[INET]: Introduce tunnel4/tunnel6 Basically this patch moves the generic tunnel protocol stuff out of xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c and tunnel6 respectively. The reason for this is that the problem that Hugo uncovered is only the tip of the iceberg. The real problem is that when we removed the dependency of ipip on xfrm4_tunnel we didn't really consider the module case at all. For instance, as it is it's possible to build both ipip and xfrm4_tunnel as modules and if the latter is loaded then ipip simply won't load. After considering the alternatives I've decided that the best way out of this is to restore the dependency of ipip on the non-xfrm-specific part of xfrm4_tunnel. This is acceptable IMHO because the intention of the removal was really to be able to use ipip without the xfrm subsystem. This is still preserved by this patch. So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles the arbitration between the two. The order of processing is determined by a simple integer which ensures that ipip gets processed before xfrm4_tunnel. The situation for ICMP handling is a little bit more complicated since we may not have enough information to determine who it's for. It's not a big deal at the moment since the xfrm ICMP handlers are basically no-ops. In future we can deal with this when we look at ICMP caching in general. The user-visible change to this is the removal of the TUNNEL Kconfig prompts. This makes sense because it can only be used through IPCOMP as it stands. The addition of the new modules shouldn't introduce any problems since module dependency will cause them to be loaded. Oh and I also turned some unnecessary pskb's in IPv6 related to this patch to skb's. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 09:12:13 +00:00
static struct xfrm6_tunnel xfrm6_tunnel_handler = {
.handler = xfrm6_tunnel_rcv,
[INET]: Introduce tunnel4/tunnel6 Basically this patch moves the generic tunnel protocol stuff out of xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c and tunnel6 respectively. The reason for this is that the problem that Hugo uncovered is only the tip of the iceberg. The real problem is that when we removed the dependency of ipip on xfrm4_tunnel we didn't really consider the module case at all. For instance, as it is it's possible to build both ipip and xfrm4_tunnel as modules and if the latter is loaded then ipip simply won't load. After considering the alternatives I've decided that the best way out of this is to restore the dependency of ipip on the non-xfrm-specific part of xfrm4_tunnel. This is acceptable IMHO because the intention of the removal was really to be able to use ipip without the xfrm subsystem. This is still preserved by this patch. So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles the arbitration between the two. The order of processing is determined by a simple integer which ensures that ipip gets processed before xfrm4_tunnel. The situation for ICMP handling is a little bit more complicated since we may not have enough information to determine who it's for. It's not a big deal at the moment since the xfrm ICMP handlers are basically no-ops. In future we can deal with this when we look at ICMP caching in general. The user-visible change to this is the removal of the TUNNEL Kconfig prompts. This makes sense because it can only be used through IPCOMP as it stands. The addition of the new modules shouldn't introduce any problems since module dependency will cause them to be loaded. Oh and I also turned some unnecessary pskb's in IPv6 related to this patch to skb's. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 09:12:13 +00:00
.err_handler = xfrm6_tunnel_err,
.priority = 2,
};
static struct xfrm6_tunnel xfrm46_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)
goto err;
if (xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6))
goto unreg;
if (xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET))
goto dereg6;
if (xfrm6_tunnel_spi_init() < 0)
goto dereg46;
return 0;
dereg46:
xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
dereg6:
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
unreg:
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
err:
return -EAGAIN;
}
static void __exit xfrm6_tunnel_fini(void)
{
xfrm6_tunnel_spi_fini();
xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
}
module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);