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/* xfrm4_tunnel.c: Generic IP tunnel transformer.
*
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
*/
#include <linux/skbuff.h>
#include <linux/module.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/protocol.h>
static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct iphdr *iph;
iph = skb->nh.iph;
iph->tot_len = htons(skb->len);
ip_send_check(iph);
return 0;
}
static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
return 0;
}
static struct xfrm_tunnel *ipip_handler;
static DECLARE_MUTEX(xfrm4_tunnel_sem);
int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
{
int ret;
down(&xfrm4_tunnel_sem);
ret = 0;
if (ipip_handler != NULL)
ret = -EINVAL;
if (!ret)
ipip_handler = handler;
up(&xfrm4_tunnel_sem);
return ret;
}
EXPORT_SYMBOL(xfrm4_tunnel_register);
int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
{
int ret;
down(&xfrm4_tunnel_sem);
ret = 0;
if (ipip_handler != handler)
ret = -EINVAL;
if (!ret)
ipip_handler = NULL;
up(&xfrm4_tunnel_sem);
synchronize_net();
return ret;
}
EXPORT_SYMBOL(xfrm4_tunnel_deregister);
static int ipip_rcv(struct sk_buff *skb)
{
struct xfrm_tunnel *handler = ipip_handler;
/* Tunnel devices take precedence. */
if (handler && handler->handler(skb) == 0)
return 0;
return xfrm4_rcv(skb);
}
static void ipip_err(struct sk_buff *skb, u32 info)
{
struct xfrm_tunnel *handler = ipip_handler;
u32 arg = info;
if (handler)
handler->err_handler(skb, &arg);
}
static int ipip_init_state(struct xfrm_state *x)
{
if (!x->props.mode)
return -EINVAL;
if (x->encap)
return -EINVAL;
x->props.header_len = sizeof(struct iphdr);
return 0;
}
static void ipip_destroy(struct xfrm_state *x)
{
}
static struct xfrm_type ipip_type = {
.description = "IPIP",
.owner = THIS_MODULE,
.proto = IPPROTO_IPIP,
.init_state = ipip_init_state,
.destructor = ipip_destroy,
.input = ipip_xfrm_rcv,
.output = ipip_output
};
static struct net_protocol ipip_protocol = {
.handler = ipip_rcv,
.err_handler = ipip_err,
.no_policy = 1,
};
static int __init ipip_init(void)
{
if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
printk(KERN_INFO "ipip init: can't add xfrm type\n");
return -EAGAIN;
}
if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) {
printk(KERN_INFO "ipip init: can't add protocol\n");
xfrm_unregister_type(&ipip_type, AF_INET);
return -EAGAIN;
}
return 0;
}
static void __exit ipip_fini(void)
{
if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0)
printk(KERN_INFO "ipip close: can't remove protocol\n");
if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
printk(KERN_INFO "ipip close: can't remove xfrm type\n");
}
module_init(ipip_init);
module_exit(ipip_fini);
MODULE_LICENSE("GPL");
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