xref: /openbmc/linux/net/ipv4/tunnel4.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 <net/icmp.h>
12 #include <net/ip.h>
13 #include <net/protocol.h>
14 #include <net/xfrm.h>
15 
16 static struct xfrm_tunnel *tunnel4_handlers;
17 static struct xfrm_tunnel *tunnel64_handlers;
18 static DEFINE_MUTEX(tunnel4_mutex);
19 
20 int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family)
21 {
22 	struct xfrm_tunnel **pprev;
23 	int ret = -EEXIST;
24 	int priority = handler->priority;
25 
26 	mutex_lock(&tunnel4_mutex);
27 
28 	for (pprev = (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
29 	     *pprev; pprev = &(*pprev)->next) {
30 		if ((*pprev)->priority > priority)
31 			break;
32 		if ((*pprev)->priority == priority)
33 			goto err;
34 	}
35 
36 	handler->next = *pprev;
37 	*pprev = handler;
38 
39 	ret = 0;
40 
41 err:
42 	mutex_unlock(&tunnel4_mutex);
43 
44 	return ret;
45 }
46 
47 EXPORT_SYMBOL(xfrm4_tunnel_register);
48 
49 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family)
50 {
51 	struct xfrm_tunnel **pprev;
52 	int ret = -ENOENT;
53 
54 	mutex_lock(&tunnel4_mutex);
55 
56 	for (pprev = (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
57 	     *pprev; pprev = &(*pprev)->next) {
58 		if (*pprev == handler) {
59 			*pprev = handler->next;
60 			ret = 0;
61 			break;
62 		}
63 	}
64 
65 	mutex_unlock(&tunnel4_mutex);
66 
67 	synchronize_net();
68 
69 	return ret;
70 }
71 
72 EXPORT_SYMBOL(xfrm4_tunnel_deregister);
73 
74 static int tunnel4_rcv(struct sk_buff *skb)
75 {
76 	struct xfrm_tunnel *handler;
77 
78 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
79 		goto drop;
80 
81 	for (handler = tunnel4_handlers; handler; handler = handler->next)
82 		if (!handler->handler(skb))
83 			return 0;
84 
85 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
86 
87 drop:
88 	kfree_skb(skb);
89 	return 0;
90 }
91 
92 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
93 static int tunnel64_rcv(struct sk_buff *skb)
94 {
95 	struct xfrm_tunnel *handler;
96 
97 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
98 		goto drop;
99 
100 	for (handler = tunnel64_handlers; handler; handler = handler->next)
101 		if (!handler->handler(skb))
102 			return 0;
103 
104 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
105 
106 drop:
107 	kfree_skb(skb);
108 	return 0;
109 }
110 #endif
111 
112 static void tunnel4_err(struct sk_buff *skb, u32 info)
113 {
114 	struct xfrm_tunnel *handler;
115 
116 	for (handler = tunnel4_handlers; handler; handler = handler->next)
117 		if (!handler->err_handler(skb, info))
118 			break;
119 }
120 
121 static struct net_protocol tunnel4_protocol = {
122 	.handler	=	tunnel4_rcv,
123 	.err_handler	=	tunnel4_err,
124 	.no_policy	=	1,
125 };
126 
127 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
128 static struct net_protocol tunnel64_protocol = {
129 	.handler	=	tunnel64_rcv,
130 	.err_handler	=	tunnel4_err,
131 	.no_policy	=	1,
132 };
133 #endif
134 
135 static int __init tunnel4_init(void)
136 {
137 	if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
138 		printk(KERN_ERR "tunnel4 init: can't add protocol\n");
139 		return -EAGAIN;
140 	}
141 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
142 	if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
143 		printk(KERN_ERR "tunnel64 init: can't add protocol\n");
144 		inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
145 		return -EAGAIN;
146 	}
147 #endif
148 	return 0;
149 }
150 
151 static void __exit tunnel4_fini(void)
152 {
153 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
154 	if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
155 		printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
156 #endif
157 	if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
158 		printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
159 }
160 
161 module_init(tunnel4_init);
162 module_exit(tunnel4_fini);
163 MODULE_LICENSE("GPL");
164