23e2809878ae87a82e527415b399d80b493103d8
[linux-2.6.git] / net / ipv6 / tunnel6.c
1 /*
2  * Copyright (C)2003,2004 USAGI/WIDE Project
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17  *
18  * Authors      Mitsuru KANDA  <mk@linux-ipv6.org>
19  *              YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
20  */
21
22 #include <linux/icmpv6.h>
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <net/ipv6.h>
29 #include <net/protocol.h>
30 #include <net/xfrm.h>
31
32 static struct xfrm6_tunnel *tunnel6_handlers;
33 static struct xfrm6_tunnel *tunnel46_handlers;
34 static DEFINE_MUTEX(tunnel6_mutex);
35
36 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
37 {
38         struct xfrm6_tunnel **pprev;
39         int ret = -EEXIST;
40         int priority = handler->priority;
41
42         mutex_lock(&tunnel6_mutex);
43
44         for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
45              *pprev; pprev = &(*pprev)->next) {
46                 if ((*pprev)->priority > priority)
47                         break;
48                 if ((*pprev)->priority == priority)
49                         goto err;
50         }
51
52         handler->next = *pprev;
53         *pprev = handler;
54
55         ret = 0;
56
57 err:
58         mutex_unlock(&tunnel6_mutex);
59
60         return ret;
61 }
62
63 EXPORT_SYMBOL(xfrm6_tunnel_register);
64
65 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
66 {
67         struct xfrm6_tunnel **pprev;
68         int ret = -ENOENT;
69
70         mutex_lock(&tunnel6_mutex);
71
72         for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
73              *pprev; pprev = &(*pprev)->next) {
74                 if (*pprev == handler) {
75                         *pprev = handler->next;
76                         ret = 0;
77                         break;
78                 }
79         }
80
81         mutex_unlock(&tunnel6_mutex);
82
83         synchronize_net();
84
85         return ret;
86 }
87
88 EXPORT_SYMBOL(xfrm6_tunnel_deregister);
89
90 static int tunnel6_rcv(struct sk_buff **pskb)
91 {
92         struct sk_buff *skb = *pskb;
93         struct xfrm6_tunnel *handler;
94
95         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
96                 goto drop;
97
98         for (handler = tunnel6_handlers; handler; handler = handler->next)
99                 if (!handler->handler(skb))
100                         return 0;
101
102         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev);
103
104 drop:
105         kfree_skb(skb);
106         return 0;
107 }
108
109 static int tunnel46_rcv(struct sk_buff **pskb)
110 {
111         struct sk_buff *skb = *pskb;
112         struct xfrm6_tunnel *handler;
113
114         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
115                 goto drop;
116
117         for (handler = tunnel46_handlers; handler; handler = handler->next)
118                 if (!handler->handler(skb))
119                         return 0;
120
121         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev);
122
123 drop:
124         kfree_skb(skb);
125         return 0;
126 }
127
128 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
129                         int type, int code, int offset, __be32 info)
130 {
131         struct xfrm6_tunnel *handler;
132
133         for (handler = tunnel6_handlers; handler; handler = handler->next)
134                 if (!handler->err_handler(skb, opt, type, code, offset, info))
135                         break;
136 }
137
138 static struct inet6_protocol tunnel6_protocol = {
139         .handler        = tunnel6_rcv,
140         .err_handler    = tunnel6_err,
141         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
142 };
143
144 static struct inet6_protocol tunnel46_protocol = {
145         .handler        = tunnel46_rcv,
146         .err_handler    = tunnel6_err,
147         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
148 };
149
150 static int __init tunnel6_init(void)
151 {
152         if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
153                 printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
154                 return -EAGAIN;
155         }
156         if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
157                 printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
158                 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
159                 return -EAGAIN;
160         }
161         return 0;
162 }
163
164 static void __exit tunnel6_fini(void)
165 {
166         if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
167                 printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
168         if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
169                 printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
170 }
171
172 module_init(tunnel6_init);
173 module_exit(tunnel6_fini);
174 MODULE_LICENSE("GPL");