aboutsummaryrefslogtreecommitdiff
path: root/net/ipv4/xfrm4_tunnel.c
blob: e1fe360ed27ad1645a861c07ddabd2293694f694 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/* xfrm4_tunnel.c: Generic IP tunnel transformer.
 *
 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
 */

#include <linux/skbuff.h>
#include <linux/module.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/protocol.h>

static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct iphdr *iph;
	
	iph = skb->nh.iph;
	iph->tot_len = htons(skb->len);
	ip_send_check(iph);

	return 0;
}

static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
	return 0;
}

static struct xfrm_tunnel *ipip_handler;
static DECLARE_MUTEX(xfrm4_tunnel_sem);

int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
{
	int ret;

	down(&xfrm4_tunnel_sem);
	ret = 0;
	if (ipip_handler != NULL)
		ret = -EINVAL;
	if (!ret)
		ipip_handler = handler;
	up(&xfrm4_tunnel_sem);

	return ret;
}

EXPORT_SYMBOL(xfrm4_tunnel_register);

int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
{
	int ret;

	down(&xfrm4_tunnel_sem);
	ret = 0;
	if (ipip_handler != handler)
		ret = -EINVAL;
	if (!ret)
		ipip_handler = NULL;
	up(&xfrm4_tunnel_sem);

	synchronize_net();

	return ret;
}

EXPORT_SYMBOL(xfrm4_tunnel_deregister);

static int ipip_rcv(struct sk_buff *skb)
{
	struct xfrm_tunnel *handler = ipip_handler;

	/* Tunnel devices take precedence.  */
	if (handler && handler->handler(skb) == 0)
		return 0;

	return xfrm4_rcv(skb);
}

static void ipip_err(struct sk_buff *skb, u32 info)
{
	struct xfrm_tunnel *handler = ipip_handler;
	u32 arg = info;

	if (handler)
		handler->err_handler(skb, &arg);
}

static int ipip_init_state(struct xfrm_state *x)
{
	if (!x->props.mode)
		return -EINVAL;

	if (x->encap)
		return -EINVAL;

	x->props.header_len = sizeof(struct iphdr);

	return 0;
}

static void ipip_destroy(struct xfrm_state *x)
{
}

static struct xfrm_type ipip_type = {
	.description	= "IPIP",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_IPIP,
	.init_state	= ipip_init_state,
	.destructor	= ipip_destroy,
	.input		= ipip_xfrm_rcv,
	.output		= ipip_output
};

static struct net_protocol ipip_protocol = {
	.handler	=	ipip_rcv,
	.err_handler	=	ipip_err,
	.no_policy	=	1,
};

static int __init ipip_init(void)
{
	if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
		printk(KERN_INFO "ipip init: can't add xfrm type\n");
		return -EAGAIN;
	}
	if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) {
		printk(KERN_INFO "ipip init: can't add protocol\n");
		xfrm_unregister_type(&ipip_type, AF_INET);
		return -EAGAIN;
	}
	return 0;
}

static void __exit ipip_fini(void)
{
	if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0)
		printk(KERN_INFO "ipip close: can't remove protocol\n");
	if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
		printk(KERN_INFO "ipip close: can't remove xfrm type\n");
}

module_init(ipip_init);
module_exit(ipip_fini);
MODULE_LICENSE("GPL");