Merge v4.4-rc1 into MTD development
[linux-2.6-microblaze.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, see <http://www.gnu.org/licenses/>.
16  *
17  * Authors      Mitsuru KANDA  <mk@linux-ipv6.org>
18  *              YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
19  */
20
21 #define pr_fmt(fmt) "IPv6: " fmt
22
23 #include <linux/icmpv6.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/mutex.h>
27 #include <linux/netdevice.h>
28 #include <linux/skbuff.h>
29 #include <linux/slab.h>
30 #include <net/ipv6.h>
31 #include <net/protocol.h>
32 #include <net/xfrm.h>
33
34 static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
35 static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
36 static DEFINE_MUTEX(tunnel6_mutex);
37
38 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
39 {
40         struct xfrm6_tunnel __rcu **pprev;
41         struct xfrm6_tunnel *t;
42         int ret = -EEXIST;
43         int priority = handler->priority;
44
45         mutex_lock(&tunnel6_mutex);
46
47         for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
48              (t = rcu_dereference_protected(*pprev,
49                         lockdep_is_held(&tunnel6_mutex))) != NULL;
50              pprev = &t->next) {
51                 if (t->priority > priority)
52                         break;
53                 if (t->priority == priority)
54                         goto err;
55         }
56
57         handler->next = *pprev;
58         rcu_assign_pointer(*pprev, handler);
59
60         ret = 0;
61
62 err:
63         mutex_unlock(&tunnel6_mutex);
64
65         return ret;
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 EXPORT_SYMBOL(xfrm6_tunnel_deregister);
95
96 #define for_each_tunnel_rcu(head, handler)              \
97         for (handler = rcu_dereference(head);           \
98              handler != NULL;                           \
99              handler = rcu_dereference(handler->next))  \
100
101 static int tunnel6_rcv(struct sk_buff *skb)
102 {
103         struct xfrm6_tunnel *handler;
104
105         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
106                 goto drop;
107
108         for_each_tunnel_rcu(tunnel6_handlers, handler)
109                 if (!handler->handler(skb))
110                         return 0;
111
112         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
113
114 drop:
115         kfree_skb(skb);
116         return 0;
117 }
118
119 static int tunnel46_rcv(struct sk_buff *skb)
120 {
121         struct xfrm6_tunnel *handler;
122
123         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
124                 goto drop;
125
126         for_each_tunnel_rcu(tunnel46_handlers, handler)
127                 if (!handler->handler(skb))
128                         return 0;
129
130         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
131
132 drop:
133         kfree_skb(skb);
134         return 0;
135 }
136
137 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
138                         u8 type, u8 code, int offset, __be32 info)
139 {
140         struct xfrm6_tunnel *handler;
141
142         for_each_tunnel_rcu(tunnel6_handlers, handler)
143                 if (!handler->err_handler(skb, opt, type, code, offset, info))
144                         break;
145 }
146
147 static void tunnel46_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
148                          u8 type, u8 code, int offset, __be32 info)
149 {
150         struct xfrm6_tunnel *handler;
151
152         for_each_tunnel_rcu(tunnel46_handlers, handler)
153                 if (!handler->err_handler(skb, opt, type, code, offset, info))
154                         break;
155 }
156
157 static const struct inet6_protocol tunnel6_protocol = {
158         .handler        = tunnel6_rcv,
159         .err_handler    = tunnel6_err,
160         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
161 };
162
163 static const struct inet6_protocol tunnel46_protocol = {
164         .handler        = tunnel46_rcv,
165         .err_handler    = tunnel46_err,
166         .flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
167 };
168
169 static int __init tunnel6_init(void)
170 {
171         if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
172                 pr_err("%s: can't add protocol\n", __func__);
173                 return -EAGAIN;
174         }
175         if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
176                 pr_err("%s: can't add protocol\n", __func__);
177                 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
178                 return -EAGAIN;
179         }
180         return 0;
181 }
182
183 static void __exit tunnel6_fini(void)
184 {
185         if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
186                 pr_err("%s: can't remove protocol\n", __func__);
187         if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
188                 pr_err("%s: can't remove protocol\n", __func__);
189 }
190
191 module_init(tunnel6_init);
192 module_exit(tunnel6_fini);
193 MODULE_LICENSE("GPL");