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
32static struct xfrm6_tunnel *tunnel6_handlers;
33static struct xfrm6_tunnel *tunnel46_handlers;
34static DEFINE_MUTEX(tunnel6_mutex);
35
36int 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
57err:
58	mutex_unlock(&tunnel6_mutex);
59
60	return ret;
61}
62
63EXPORT_SYMBOL(xfrm6_tunnel_register);
64
65int 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
88EXPORT_SYMBOL(xfrm6_tunnel_deregister);
89
90static 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
104drop:
105	kfree_skb(skb);
106	return 0;
107}
108
109static 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
123drop:
124	kfree_skb(skb);
125	return 0;
126}
127
128static 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
138static struct inet6_protocol tunnel6_protocol = {
139	.handler	= tunnel6_rcv,
140	.err_handler	= tunnel6_err,
141	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
142};
143
144static struct inet6_protocol tunnel46_protocol = {
145	.handler	= tunnel46_rcv,
146	.err_handler	= tunnel6_err,
147	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
148};
149
150static 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
164static 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
172module_init(tunnel6_init);
173module_exit(tunnel6_fini);
174MODULE_LICENSE("GPL");
175