[IPSEC]: Add xfrm_init_state
[linux-2.6.git] / net / ipv4 / xfrm4_tunnel.c
1 /* xfrm4_tunnel.c: Generic IP tunnel transformer.
2  *
3  * Copyright (C) 2003 David S. Miller (davem@redhat.com)
4  */
5
6 #include <linux/skbuff.h>
7 #include <linux/module.h>
8 #include <net/xfrm.h>
9 #include <net/ip.h>
10 #include <net/protocol.h>
11
12 static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
13 {
14         struct iphdr *iph;
15         
16         iph = skb->nh.iph;
17         iph->tot_len = htons(skb->len);
18         ip_send_check(iph);
19
20         return 0;
21 }
22
23 static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
24 {
25         return 0;
26 }
27
28 static struct xfrm_tunnel *ipip_handler;
29 static DECLARE_MUTEX(xfrm4_tunnel_sem);
30
31 int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
32 {
33         int ret;
34
35         down(&xfrm4_tunnel_sem);
36         ret = 0;
37         if (ipip_handler != NULL)
38                 ret = -EINVAL;
39         if (!ret)
40                 ipip_handler = handler;
41         up(&xfrm4_tunnel_sem);
42
43         return ret;
44 }
45
46 EXPORT_SYMBOL(xfrm4_tunnel_register);
47
48 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
49 {
50         int ret;
51
52         down(&xfrm4_tunnel_sem);
53         ret = 0;
54         if (ipip_handler != handler)
55                 ret = -EINVAL;
56         if (!ret)
57                 ipip_handler = NULL;
58         up(&xfrm4_tunnel_sem);
59
60         synchronize_net();
61
62         return ret;
63 }
64
65 EXPORT_SYMBOL(xfrm4_tunnel_deregister);
66
67 static int ipip_rcv(struct sk_buff *skb)
68 {
69         struct xfrm_tunnel *handler = ipip_handler;
70
71         /* Tunnel devices take precedence.  */
72         if (handler && handler->handler(skb) == 0)
73                 return 0;
74
75         return xfrm4_rcv(skb);
76 }
77
78 static void ipip_err(struct sk_buff *skb, u32 info)
79 {
80         struct xfrm_tunnel *handler = ipip_handler;
81         u32 arg = info;
82
83         if (handler)
84                 handler->err_handler(skb, &arg);
85 }
86
87 static int ipip_init_state(struct xfrm_state *x)
88 {
89         if (!x->props.mode)
90                 return -EINVAL;
91
92         if (x->encap)
93                 return -EINVAL;
94
95         x->props.header_len = sizeof(struct iphdr);
96
97         return 0;
98 }
99
100 static void ipip_destroy(struct xfrm_state *x)
101 {
102 }
103
104 static struct xfrm_type ipip_type = {
105         .description    = "IPIP",
106         .owner          = THIS_MODULE,
107         .proto          = IPPROTO_IPIP,
108         .init_state     = ipip_init_state,
109         .destructor     = ipip_destroy,
110         .input          = ipip_xfrm_rcv,
111         .output         = ipip_output
112 };
113
114 static struct net_protocol ipip_protocol = {
115         .handler        =       ipip_rcv,
116         .err_handler    =       ipip_err,
117         .no_policy      =       1,
118 };
119
120 static int __init ipip_init(void)
121 {
122         if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
123                 printk(KERN_INFO "ipip init: can't add xfrm type\n");
124                 return -EAGAIN;
125         }
126         if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) {
127                 printk(KERN_INFO "ipip init: can't add protocol\n");
128                 xfrm_unregister_type(&ipip_type, AF_INET);
129                 return -EAGAIN;
130         }
131         return 0;
132 }
133
134 static void __exit ipip_fini(void)
135 {
136         if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0)
137                 printk(KERN_INFO "ipip close: can't remove protocol\n");
138         if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
139                 printk(KERN_INFO "ipip close: can't remove xfrm type\n");
140 }
141
142 module_init(ipip_init);
143 module_exit(ipip_fini);
144 MODULE_LICENSE("GPL");