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