[TCP] FRTO: Improve interoperability with other undo_marker users
[linux-2.6] / 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 <linux/mutex.h>
9 #include <net/xfrm.h>
10 #include <net/ip.h>
11 #include <net/protocol.h>
12
13 static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
14 {
15         struct iphdr *iph = ip_hdr(skb);
16
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 sk_buff *skb)
24 {
25         return 0;
26 }
27
28 static int ipip_init_state(struct xfrm_state *x)
29 {
30         if (x->props.mode != XFRM_MODE_TUNNEL)
31                 return -EINVAL;
32
33         if (x->encap)
34                 return -EINVAL;
35
36         x->props.header_len = sizeof(struct iphdr);
37
38         return 0;
39 }
40
41 static void ipip_destroy(struct xfrm_state *x)
42 {
43 }
44
45 static struct xfrm_type ipip_type = {
46         .description    = "IPIP",
47         .owner          = THIS_MODULE,
48         .proto          = IPPROTO_IPIP,
49         .init_state     = ipip_init_state,
50         .destructor     = ipip_destroy,
51         .input          = ipip_xfrm_rcv,
52         .output         = ipip_output
53 };
54
55 static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
56 {
57         return -ENOENT;
58 }
59
60 static struct xfrm_tunnel xfrm_tunnel_handler = {
61         .handler        =       xfrm4_rcv,
62         .err_handler    =       xfrm_tunnel_err,
63         .priority       =       2,
64 };
65
66 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
67 static struct xfrm_tunnel xfrm64_tunnel_handler = {
68         .handler        =       xfrm4_rcv,
69         .err_handler    =       xfrm_tunnel_err,
70         .priority       =       2,
71 };
72 #endif
73
74 static int __init ipip_init(void)
75 {
76         if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
77                 printk(KERN_INFO "ipip init: can't add xfrm type\n");
78                 return -EAGAIN;
79         }
80
81         if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
82                 printk(KERN_INFO "ipip init: can't add xfrm handler for AF_INET\n");
83                 xfrm_unregister_type(&ipip_type, AF_INET);
84                 return -EAGAIN;
85         }
86 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
87         if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
88                 printk(KERN_INFO "ipip init: can't add xfrm handler for AF_INET6\n");
89                 xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET);
90                 xfrm_unregister_type(&ipip_type, AF_INET);
91                 return -EAGAIN;
92         }
93 #endif
94         return 0;
95 }
96
97 static void __exit ipip_fini(void)
98 {
99 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
100         if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6))
101                 printk(KERN_INFO "ipip close: can't remove xfrm handler for AF_INET6\n");
102 #endif
103         if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET))
104                 printk(KERN_INFO "ipip close: can't remove xfrm handler for AF_INET\n");
105         if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
106                 printk(KERN_INFO "ipip close: can't remove xfrm type\n");
107 }
108
109 module_init(ipip_init);
110 module_exit(ipip_fini);
111 MODULE_LICENSE("GPL");
112 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);