xref: /openbmc/linux/net/ipv4/xfrm4_tunnel.c (revision 8bd1369b)
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 
15 static 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 
21 static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
22 {
23 	return ip_hdr(skb)->protocol;
24 }
25 
26 static 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 
39 static void ipip_destroy(struct xfrm_state *x)
40 {
41 }
42 
43 static 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 
53 static int xfrm_tunnel_rcv(struct sk_buff *skb)
54 {
55 	return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
56 }
57 
58 static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
59 {
60 	return -ENOENT;
61 }
62 
63 static 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)
70 static 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 
77 static 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 
100 static 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 
114 module_init(ipip_init);
115 module_exit(ipip_fini);
116 MODULE_LICENSE("GPL");
117 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);
118