LXR linux/net/ipv4/xfrm4

   1/* xfrm4_tunnel.c: Generic IP tunnel transformer.
   2 *
   3 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
   4 */
   5
   6#define pr_fmt(fmt) "IPsec: " fmt
   7
   8#include <linux/skbuff.h>
   9#include <linux/module.h>
  10#include <linux/mutex.h>
  11#include <net/xfrm.h>
  12#include <net/ip.h>
  13#include <net/protocol.h>
  14
  15static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
  16{
  17        skb_push(skb, -skb_network_offset(skb));
  18        return 0;
  19}
  20
  21static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
  22{
  23        return ip_hdr(skb)->protocol;
  24}
  25
  26static int ipip_init_state(struct xfrm_state *x)
  27{
  28        if (x->props.mode != XFRM_MODE_TUNNEL)
  29                return -EINVAL;
  30
  31        if (x->encap)
  32                return -EINVAL;
  33
  34        x->props.header_len = sizeof(struct iphdr);
  35
  36        return 0;
  37}
  38
  39static void ipip_destroy(struct xfrm_state *x)
  40{
  41}
  42
  43static const struct xfrm_type ipip_type = {
  44        .description    = "IPIP",
  45        .owner          = THIS_MODULE,
  46        .proto          = IPPROTO_IPIP,
  47        .init_state     = ipip_init_state,
  48        .destructor     = ipip_destroy,
  49        .input          = ipip_xfrm_rcv,
  50        .output         = ipip_output
  51};
  52
  53static int xfrm_tunnel_rcv(struct sk_buff *skb)
  54{
  55        return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
  56}
  57
  58static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
  59{
  60        return -ENOENT;
  61}
  62
  63static struct xfrm_tunnel xfrm_tunnel_handler __read_mostly = {
  64        .handler        =       xfrm_tunnel_rcv,
  65        .err_handler    =       xfrm_tunnel_err,
  66        .priority       =       3,
  67};
  68
  69#if IS_ENABLED(CONFIG_IPV6)
  70static struct xfrm_tunnel xfrm64_tunnel_handler __read_mostly = {
  71        .handler        =       xfrm_tunnel_rcv,
  72        .err_handler    =       xfrm_tunnel_err,
  73        .priority       =       2,
  74};
  75#endif
  76
  77static int __init ipip_init(void)
  78{
  79        if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
  80                pr_info("%s: can't add xfrm type\n", __func__);
  81                return -EAGAIN;
  82        }
  83
  84        if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
  85                pr_info("%s: can't add xfrm handler for AF_INET\n", __func__);
  86                xfrm_unregister_type(&ipip_type, AF_INET);
  87                return -EAGAIN;
  88        }
  89#if IS_ENABLED(CONFIG_IPV6)
  90        if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
  91                pr_info("%s: can't add xfrm handler for AF_INET6\n", __func__);
  92                xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET);
  93                xfrm_unregister_type(&ipip_type, AF_INET);
  94                return -EAGAIN;
  95        }
  96#endif
  97        return 0;
  98}
  99
 100static void __exit ipip_fini(void)
 101{
 102#if IS_ENABLED(CONFIG_IPV6)
 103        if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6))
 104                pr_info("%s: can't remove xfrm handler for AF_INET6\n",
 105                        __func__);
 106#endif
 107        if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET))
 108                pr_info("%s: can't remove xfrm handler for AF_INET\n",
 109                        __func__);
 110        if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
 111                pr_info("%s: can't remove xfrm type\n", __func__);
 112}
 113
 114module_init(ipip_init);
 115module_exit(ipip_fini);
 116MODULE_LICENSE("GPL");
 117MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);
 118