net/ipv4: EXPORT_SYMBOL cleanups
[linux-2.6.git] / net / ipv4 / tunnel4.c
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
17 static struct xfrm_tunnel *tunnel4_handlers;
18 static struct xfrm_tunnel *tunnel64_handlers;
19 static DEFINE_MUTEX(tunnel4_mutex);
20
21 static inline struct xfrm_tunnel **fam_handlers(unsigned short family)
22 {
23         return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
24 }
25
26 int 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
46 err:
47         mutex_unlock(&tunnel4_mutex);
48
49         return ret;
50 }
51 EXPORT_SYMBOL(xfrm4_tunnel_register);
52
53 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family)
54 {
55         struct xfrm_tunnel **pprev;
56         int ret = -ENOENT;
57
58         mutex_lock(&tunnel4_mutex);
59
60         for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
61                 if (*pprev == handler) {
62                         *pprev = handler->next;
63                         ret = 0;
64                         break;
65                 }
66         }
67
68         mutex_unlock(&tunnel4_mutex);
69
70         synchronize_net();
71
72         return ret;
73 }
74 EXPORT_SYMBOL(xfrm4_tunnel_deregister);
75
76 static int tunnel4_rcv(struct sk_buff *skb)
77 {
78         struct xfrm_tunnel *handler;
79
80         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
81                 goto drop;
82
83         for (handler = tunnel4_handlers; handler; handler = handler->next)
84                 if (!handler->handler(skb))
85                         return 0;
86
87         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
88
89 drop:
90         kfree_skb(skb);
91         return 0;
92 }
93
94 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
95 static int tunnel64_rcv(struct sk_buff *skb)
96 {
97         struct xfrm_tunnel *handler;
98
99         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
100                 goto drop;
101
102         for (handler = tunnel64_handlers; handler; handler = handler->next)
103                 if (!handler->handler(skb))
104                         return 0;
105
106         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
107
108 drop:
109         kfree_skb(skb);
110         return 0;
111 }
112 #endif
113
114 static void tunnel4_err(struct sk_buff *skb, u32 info)
115 {
116         struct xfrm_tunnel *handler;
117
118         for (handler = tunnel4_handlers; handler; handler = handler->next)
119                 if (!handler->err_handler(skb, info))
120                         break;
121 }
122
123 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
124 static void tunnel64_err(struct sk_buff *skb, u32 info)
125 {
126         struct xfrm_tunnel *handler;
127
128         for (handler = tunnel64_handlers; handler; handler = handler->next)
129                 if (!handler->err_handler(skb, info))
130                         break;
131 }
132 #endif
133
134 static const struct net_protocol tunnel4_protocol = {
135         .handler        =       tunnel4_rcv,
136         .err_handler    =       tunnel4_err,
137         .no_policy      =       1,
138         .netns_ok       =       1,
139 };
140
141 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
142 static const struct net_protocol tunnel64_protocol = {
143         .handler        =       tunnel64_rcv,
144         .err_handler    =       tunnel64_err,
145         .no_policy      =       1,
146         .netns_ok       =       1,
147 };
148 #endif
149
150 static int __init tunnel4_init(void)
151 {
152         if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
153                 printk(KERN_ERR "tunnel4 init: can't add protocol\n");
154                 return -EAGAIN;
155         }
156 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
157         if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
158                 printk(KERN_ERR "tunnel64 init: can't add protocol\n");
159                 inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
160                 return -EAGAIN;
161         }
162 #endif
163         return 0;
164 }
165
166 static void __exit tunnel4_fini(void)
167 {
168 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
169         if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
170                 printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
171 #endif
172         if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
173                 printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
174 }
175
176 module_init(tunnel4_init);
177 module_exit(tunnel4_fini);
178 MODULE_LICENSE("GPL");