sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd
[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 <linux/slab.h>
29 #include <net/ipv6.h>
30 #include <net/protocol.h>
31 #include <net/xfrm.h>
32
33 static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
34 static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
35 static DEFINE_MUTEX(tunnel6_mutex);
36
37 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
38 {
39         struct xfrm6_tunnel __rcu **pprev;
40         struct xfrm6_tunnel *t;
41         int ret = -EEXIST;
42         int priority = handler->priority;
43
44         mutex_lock(&tunnel6_mutex);
45
46         for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
47              (t = rcu_dereference_protected(*pprev,
48                         lockdep_is_held(&tunnel6_mutex))) != NULL;
49              pprev = &t->next) {
50                 if (t->priority > priority)
51                         break;
52                 if (t->priority == priority)
53                         goto err;
54         }
55
56         handler->next = *pprev;
57         rcu_assign_pointer(*pprev, handler);
58
59         ret = 0;
60
61 err:
62         mutex_unlock(&tunnel6_mutex);
63
64         return ret;
65 }
66
67 EXPORT_SYMBOL(xfrm6_tunnel_register);
68
69 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
70 {
71         struct xfrm6_tunnel __rcu **pprev;
72         struct xfrm6_tunnel *t;
73         int ret = -ENOENT;
74
75         mutex_lock(&tunnel6_mutex);
76
77         for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
78              (t = rcu_dereference_protected(*pprev,
79                         lockdep_is_held(&tunnel6_mutex))) != NULL;
80              pprev = &t->next) {
81                 if (t == handler) {
82                         *pprev = handler->next;
83                         ret = 0;
84                         break;
85                 }
86         }
87
88         mutex_unlock(&tunnel6_mutex);
89
90         synchronize_net();
91
92         return ret;
93 }
94
95 EXPORT_SYMBOL(xfrm6_tunnel_deregister);
96
97 #define for_each_tunnel_rcu(head, handler)              \
98         for (handler = rcu_dereference(head);           \
99              handler != NULL;                           \
100              handler = rcu_dereference(handler->next))  \
101
102 static int tunnel6_rcv(struct sk_buff *skb)
103 {
104         struct xfrm6_tunnel *handler;
105
106         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
107                 goto drop;
108
109         for_each_tunnel_rcu(tunnel6_handlers, handler)
110                 if (!handler->handler(skb))
111                         return 0;
112
113         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
114
115 drop:
116         kfree_skb(skb);
117         return 0;
118 }
119
120 static int tunnel46_rcv(struct sk_buff *skb)
121 {
122         struct xfrm6_tunnel *handler;
123
124         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
125                 goto drop;
126
127         for_each_tunnel_rcu(tunnel46_handlers, handler)
128                 if (!handler->handler(skb))
129                         return 0;
130
131         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
132
133 drop:
134         kfree_skb(skb);
135         return 0;
136 }
137
138 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
139                         u8 type, u8 code, int offset, __be32 info)
140 {
141         struct xfrm6_tunnel *handler;
142
143         for_each_tunnel_rcu(tunnel6_handlers, handler)
144                 if (!handler->err_handler(skb, opt, type, code, offset, info))
145                         break;
146 }
147
148 static const struct inet6_protocol tunnel6_protocol = {
149         .handler        = tunnel6_rcv,
150         .err_handler    = tunnel6_err,
151         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
152 };
153
154 static const struct inet6_protocol tunnel46_protocol = {
155         .handler        = tunnel46_rcv,
156         .err_handler    = tunnel6_err,
157         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
158 };
159
160 static int __init tunnel6_init(void)
161 {
162         if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
163                 printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
164                 return -EAGAIN;
165         }
166         if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
167                 printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
168                 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
169                 return -EAGAIN;
170         }
171         return 0;
172 }
173
174 static void __exit tunnel6_fini(void)
175 {
176         if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
177                 printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
178         if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
179                 printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
180 }
181
182 module_init(tunnel6_init);
183 module_exit(tunnel6_fini);
184 MODULE_LICENSE("GPL");