tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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 <linux/slab.h>
12#include <net/icmp.h>
13#include <net/ip.h>
14#include <net/protocol.h>
15#include <net/xfrm.h>
16
17static struct xfrm_tunnel *tunnel4_handlers;
18static struct xfrm_tunnel *tunnel64_handlers;
19static DEFINE_MUTEX(tunnel4_mutex);
20
21static inline struct xfrm_tunnel **fam_handlers(unsigned short family)
22{
23 return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
24}
25
26int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family)
27{
28 struct xfrm_tunnel **pprev;
29 int ret = -EEXIST;
30 int priority = handler->priority;
31
32 mutex_lock(&tunnel4_mutex);
33
34 for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
35 if ((*pprev)->priority > priority)
36 break;
37 if ((*pprev)->priority == priority)
38 goto err;
39 }
40
41 handler->next = *pprev;
42 *pprev = handler;
43
44 ret = 0;
45
46err:
47 mutex_unlock(&tunnel4_mutex);
48
49 return ret;
50}
51
52EXPORT_SYMBOL(xfrm4_tunnel_register);
53
54int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family)
55{
56 struct xfrm_tunnel **pprev;
57 int ret = -ENOENT;
58
59 mutex_lock(&tunnel4_mutex);
60
61 for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
62 if (*pprev == handler) {
63 *pprev = handler->next;
64 ret = 0;
65 break;
66 }
67 }
68
69 mutex_unlock(&tunnel4_mutex);
70
71 synchronize_net();
72
73 return ret;
74}
75
76EXPORT_SYMBOL(xfrm4_tunnel_deregister);
77
78static int tunnel4_rcv(struct sk_buff *skb)
79{
80 struct xfrm_tunnel *handler;
81
82 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
83 goto drop;
84
85 for (handler = tunnel4_handlers; handler; handler = handler->next)
86 if (!handler->handler(skb))
87 return 0;
88
89 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
90
91drop:
92 kfree_skb(skb);
93 return 0;
94}
95
96#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
97static int tunnel64_rcv(struct sk_buff *skb)
98{
99 struct xfrm_tunnel *handler;
100
101 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
102 goto drop;
103
104 for (handler = tunnel64_handlers; handler; handler = handler->next)
105 if (!handler->handler(skb))
106 return 0;
107
108 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
109
110drop:
111 kfree_skb(skb);
112 return 0;
113}
114#endif
115
116static void tunnel4_err(struct sk_buff *skb, u32 info)
117{
118 struct xfrm_tunnel *handler;
119
120 for (handler = tunnel4_handlers; handler; handler = handler->next)
121 if (!handler->err_handler(skb, info))
122 break;
123}
124
125#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
126static void tunnel64_err(struct sk_buff *skb, u32 info)
127{
128 struct xfrm_tunnel *handler;
129
130 for (handler = tunnel64_handlers; handler; handler = handler->next)
131 if (!handler->err_handler(skb, info))
132 break;
133}
134#endif
135
136static const struct net_protocol tunnel4_protocol = {
137 .handler = tunnel4_rcv,
138 .err_handler = tunnel4_err,
139 .no_policy = 1,
140 .netns_ok = 1,
141};
142
143#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
144static const struct net_protocol tunnel64_protocol = {
145 .handler = tunnel64_rcv,
146 .err_handler = tunnel64_err,
147 .no_policy = 1,
148 .netns_ok = 1,
149};
150#endif
151
152static int __init tunnel4_init(void)
153{
154 if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
155 printk(KERN_ERR "tunnel4 init: can't add protocol\n");
156 return -EAGAIN;
157 }
158#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
159 if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
160 printk(KERN_ERR "tunnel64 init: can't add protocol\n");
161 inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
162 return -EAGAIN;
163 }
164#endif
165 return 0;
166}
167
168static void __exit tunnel4_fini(void)
169{
170#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
171 if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
172 printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
173#endif
174 if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
175 printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
176}
177
178module_init(tunnel4_init);
179module_exit(tunnel4_fini);
180MODULE_LICENSE("GPL");