122 строки
2.4 KiB
C
122 строки
2.4 KiB
C
/* tunnel4.c: Generic IP tunnel transformer.
|
|
*
|
|
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/icmp.h>
|
|
#include <net/ip.h>
|
|
#include <net/protocol.h>
|
|
#include <net/xfrm.h>
|
|
|
|
static struct xfrm_tunnel *tunnel4_handlers;
|
|
static DEFINE_MUTEX(tunnel4_mutex);
|
|
|
|
int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
|
|
{
|
|
struct xfrm_tunnel **pprev;
|
|
int ret = -EEXIST;
|
|
int priority = handler->priority;
|
|
|
|
mutex_lock(&tunnel4_mutex);
|
|
|
|
for (pprev = &tunnel4_handlers; *pprev; pprev = &(*pprev)->next) {
|
|
if ((*pprev)->priority > priority)
|
|
break;
|
|
if ((*pprev)->priority == priority)
|
|
goto err;
|
|
}
|
|
|
|
handler->next = *pprev;
|
|
*pprev = handler;
|
|
|
|
ret = 0;
|
|
|
|
err:
|
|
mutex_unlock(&tunnel4_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL(xfrm4_tunnel_register);
|
|
|
|
int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
|
|
{
|
|
struct xfrm_tunnel **pprev;
|
|
int ret = -ENOENT;
|
|
|
|
mutex_lock(&tunnel4_mutex);
|
|
|
|
for (pprev = &tunnel4_handlers; *pprev; pprev = &(*pprev)->next) {
|
|
if (*pprev == handler) {
|
|
*pprev = handler->next;
|
|
ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&tunnel4_mutex);
|
|
|
|
synchronize_net();
|
|
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL(xfrm4_tunnel_deregister);
|
|
|
|
static int tunnel4_rcv(struct sk_buff *skb)
|
|
{
|
|
struct xfrm_tunnel *handler;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
|
|
goto drop;
|
|
|
|
for (handler = tunnel4_handlers; handler; handler = handler->next)
|
|
if (!handler->handler(skb))
|
|
return 0;
|
|
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return 0;
|
|
}
|
|
|
|
static void tunnel4_err(struct sk_buff *skb, u32 info)
|
|
{
|
|
struct xfrm_tunnel *handler;
|
|
|
|
for (handler = tunnel4_handlers; handler; handler = handler->next)
|
|
if (!handler->err_handler(skb, info))
|
|
break;
|
|
}
|
|
|
|
static struct net_protocol tunnel4_protocol = {
|
|
.handler = tunnel4_rcv,
|
|
.err_handler = tunnel4_err,
|
|
.no_policy = 1,
|
|
};
|
|
|
|
static int __init tunnel4_init(void)
|
|
{
|
|
if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
|
|
printk(KERN_ERR "tunnel4 init: can't add protocol\n");
|
|
return -EAGAIN;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void __exit tunnel4_fini(void)
|
|
{
|
|
if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
|
|
printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
|
|
}
|
|
|
|
module_init(tunnel4_init);
|
|
module_exit(tunnel4_fini);
|
|
MODULE_LICENSE("GPL");
|