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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* tunnel4.c: Generic IP tunnel transformer.
2 *
3 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
4 */
5
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/mutex.h>
9#include <linux/netdevice.h>
10#include <linux/skbuff.h>
11#include <net/icmp.h>
12#include <net/ip.h>
13#include <net/protocol.h>
14#include <net/xfrm.h>
15
16static struct xfrm_tunnel *tunnel4_handlers;
17static DEFINE_MUTEX(tunnel4_mutex);
18
19int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
20{
21 struct xfrm_tunnel **pprev;
22 int ret = -EEXIST;
23 int priority = handler->priority;
24
25 mutex_lock(&tunnel4_mutex);
26
27 for (pprev = &tunnel4_handlers; *pprev; pprev = &(*pprev)->next) {
28 if ((*pprev)->priority > priority)
29 break;
30 if ((*pprev)->priority == priority)
31 goto err;
32 }
33
34 handler->next = *pprev;
35 *pprev = handler;
36
37 ret = 0;
38
39err:
40 mutex_unlock(&tunnel4_mutex);
41
42 return ret;
43}
44
45EXPORT_SYMBOL(xfrm4_tunnel_register);
46
47int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
48{
49 struct xfrm_tunnel **pprev;
50 int ret = -ENOENT;
51
52 mutex_lock(&tunnel4_mutex);
53
54 for (pprev = &tunnel4_handlers; *pprev; pprev = &(*pprev)->next) {
55 if (*pprev == handler) {
56 *pprev = handler->next;
57 ret = 0;
58 break;
59 }
60 }
61
62 mutex_unlock(&tunnel4_mutex);
63
64 synchronize_net();
65
66 return ret;
67}
68
69EXPORT_SYMBOL(xfrm4_tunnel_deregister);
70
71static int tunnel4_rcv(struct sk_buff *skb)
72{
73 struct xfrm_tunnel *handler;
74
75 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
76 goto drop;
77
78 for (handler = tunnel4_handlers; handler; handler = handler->next)
79 if (!handler->handler(skb))
80 return 0;
81
82 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
83
84drop:
85 kfree_skb(skb);
86 return 0;
87}
88
89static void tunnel4_err(struct sk_buff *skb, u32 info)
90{
91 struct xfrm_tunnel *handler;
92
93 for (handler = tunnel4_handlers; handler; handler = handler->next)
94 if (!handler->err_handler(skb, info))
95 break;
96}
97
98static struct net_protocol tunnel4_protocol = {
99 .handler = tunnel4_rcv,
100 .err_handler = tunnel4_err,
101 .no_policy = 1,
102};
103
104static int __init tunnel4_init(void)
105{
106 if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
107 printk(KERN_ERR "tunnel4 init: can't add protocol\n");
108 return -EAGAIN;
109 }
110 return 0;
111}
112
113static void __exit tunnel4_fini(void)
114{
115 if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
116 printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
117}
118
119module_init(tunnel4_init);
120module_exit(tunnel4_fini);
121MODULE_LICENSE("GPL");