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;
  16
  17         iph = skb->nh.iph;
  18         iph->tot_len = htons(skb->len);
  19         ip_send_check(iph);
  20
  21         return 0;
  22 }
  23
  24 static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
  25 {
  26         return 0;
  27 }
  28
  29 static int ipip_init_state(struct xfrm_state *x)
  30 {
  31         if (x->props.mode != XFRM_MODE_TUNNEL)
  32                 return -EINVAL;
  33
  34         if (x->encap)
  35                 return -EINVAL;
  36
  37         x->props.header_len = sizeof(struct iphdr);
  38
  39         return 0;
  40 }
  41
  42 static void ipip_destroy(struct xfrm_state *x)
  43 {
  44 }
  45
  46 static struct xfrm_type ipip_type = {
  47         .description    = "IPIP",
  48         .owner          = THIS_MODULE,
  49         .proto          = IPPROTO_IPIP,
  50         .init_state     = ipip_init_state,
  51         .destructor     = ipip_destroy,
  52         .input          = ipip_xfrm_rcv,
  53         .output         = ipip_output
  54 };
  55
  56 static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
  57 {
  58         return -ENOENT;
  59 }
  60
  61 static struct xfrm_tunnel xfrm_tunnel_handler = {
  62         .handler        =       xfrm4_rcv,
  63         .err_handler    =       xfrm_tunnel_err,
  64         .priority       =       2,
  65 };
  66
  67 static int __init ipip_init(void)
  68 {
  69         if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
  70                 printk(KERN_INFO "ipip init: can't add xfrm type\n");
  71                 return -EAGAIN;
  72         }
  73         if (xfrm4_tunnel_register(&xfrm_tunnel_handler)) {
  74                 printk(KERN_INFO "ipip init: can't add xfrm handler\n");
  75                 xfrm_unregister_type(&ipip_type, AF_INET);
  76                 return -EAGAIN;
  77         }
  78         return 0;
  79 }
  80
  81 static void __exit ipip_fini(void)
  82 {
  83         if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler))
  84                 printk(KERN_INFO "ipip close: can't remove xfrm handler\n");
  85         if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
  86                 printk(KERN_INFO "ipip close: can't remove xfrm type\n");
  87 }
  88
  89 module_init(ipip_init);
  90 module_exit(ipip_fini);
  91 MODULE_LICENSE("GPL");