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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 <net/icmp.h>
12#include <net/ip.h>
13#include <net/protocol.h>
14#include <net/xfrm.h>
15
16static struct xfrm_tunnel *tunnel4_handlers;
17static struct xfrm_tunnel *tunnel64_handlers;
18static DEFINE_MUTEX(tunnel4_mutex);
19
20static inline struct xfrm_tunnel **fam_handlers(unsigned short family)
21{
22 return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
23}
24
25int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family)
26{
27 struct xfrm_tunnel **pprev;
28 int ret = -EEXIST;
29 int priority = handler->priority;
30
31 mutex_lock(&tunnel4_mutex);
32
33 for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
34 if ((*pprev)->priority > priority)
35 break;
36 if ((*pprev)->priority == priority)
37 goto err;
38 }
39
40 handler->next = *pprev;
41 *pprev = handler;
42
43 ret = 0;
44
45err:
46 mutex_unlock(&tunnel4_mutex);
47
48 return ret;
49}
50
51EXPORT_SYMBOL(xfrm4_tunnel_register);
52
53int 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
75EXPORT_SYMBOL(xfrm4_tunnel_deregister);
76
77static int tunnel4_rcv(struct sk_buff *skb)
78{
79 struct xfrm_tunnel *handler;
80
81 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
82 goto drop;
83
84 for (handler = tunnel4_handlers; handler; handler = handler->next)
85 if (!handler->handler(skb))
86 return 0;
87
88 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
89
90drop:
91 kfree_skb(skb);
92 return 0;
93}
94
95#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
96static int tunnel64_rcv(struct sk_buff *skb)
97{
98 struct xfrm_tunnel *handler;
99
100 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
101 goto drop;
102
103 for (handler = tunnel64_handlers; handler; handler = handler->next)
104 if (!handler->handler(skb))
105 return 0;
106
107 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
108
109drop:
110 kfree_skb(skb);
111 return 0;
112}
113#endif
114
115static void tunnel4_err(struct sk_buff *skb, u32 info)
116{
117 struct xfrm_tunnel *handler;
118
119 for (handler = tunnel4_handlers; handler; handler = handler->next)
120 if (!handler->err_handler(skb, info))
121 break;
122}
123
124#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
125static void tunnel64_err(struct sk_buff *skb, u32 info)
126{
127 struct xfrm_tunnel *handler;
128
129 for (handler = tunnel64_handlers; handler; handler = handler->next)
130 if (!handler->err_handler(skb, info))
131 break;
132}
133#endif
134
135static const struct net_protocol tunnel4_protocol = {
136 .handler = tunnel4_rcv,
137 .err_handler = tunnel4_err,
138 .no_policy = 1,
139 .netns_ok = 1,
140};
141
142#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
143static const struct net_protocol tunnel64_protocol = {
144 .handler = tunnel64_rcv,
145 .err_handler = tunnel64_err,
146 .no_policy = 1,
147 .netns_ok = 1,
148};
149#endif
150
151static int __init tunnel4_init(void)
152{
153 if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
154 printk(KERN_ERR "tunnel4 init: can't add protocol\n");
155 return -EAGAIN;
156 }
157#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
158 if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
159 printk(KERN_ERR "tunnel64 init: can't add protocol\n");
160 inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
161 return -EAGAIN;
162 }
163#endif
164 return 0;
165}
166
167static void __exit tunnel4_fini(void)
168{
169#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
170 if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
171 printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
172#endif
173 if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
174 printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
175}
176
177module_init(tunnel4_init);
178module_exit(tunnel4_fini);
179MODULE_LICENSE("GPL");
180
