summaryrefslogtreecommitdiff
path: root/net/x25/x25_route.c
blob: 6c5d37517035866e874cef3f82e1cda304fbafd4 (plain) (blame)
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine,
 *	randomly fail to work with new releases, misbehave and/or generally
 *	screw up. It might even work. 
 *
 *	This code REQUIRES 2.1.15 or higher
 *
 *	This module:
 *		This module is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	History
 *	X.25 001	Jonathan Naylor	Started coding.
 */

#include <linux/config.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <net/x25.h>

struct list_head x25_route_list = LIST_HEAD_INIT(x25_route_list);
DEFINE_RWLOCK(x25_route_list_lock);

/*
 *	Add a new route.
 */
static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
			 struct net_device *dev)
{
	struct x25_route *rt;
	struct list_head *entry;
	int rc = -EINVAL;

	write_lock_bh(&x25_route_list_lock);

	list_for_each(entry, &x25_route_list) {
		rt = list_entry(entry, struct x25_route, node);

		if (!memcmp(&rt->address, address, sigdigits) &&
		    rt->sigdigits == sigdigits)
			goto out;
	}

	rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
	rc = -ENOMEM;
	if (!rt)
		goto out;

	strcpy(rt->address.x25_addr, "000000000000000");
	memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);

	rt->sigdigits = sigdigits;
	rt->dev       = dev;
	atomic_set(&rt->refcnt, 1);

	list_add(&rt->node, &x25_route_list);
	rc = 0;
out:
	write_unlock_bh(&x25_route_list_lock);
	return rc;
}

/**
 * __x25_remove_route - remove route from x25_route_list
 * @rt - route to remove
 *
 * Remove route from x25_route_list. If it was there.
 * Caller must hold x25_route_list_lock.
 */
static void __x25_remove_route(struct x25_route *rt)
{
	if (rt->node.next) {
		list_del(&rt->node);
		x25_route_put(rt);
	}
}

static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
			 struct net_device *dev)
{
	struct x25_route *rt;
	struct list_head *entry;
	int rc = -EINVAL;

	write_lock_bh(&x25_route_list_lock);

	list_for_each(entry, &x25_route_list) {
		rt = list_entry(entry, struct x25_route, node);

		if (!memcmp(&rt->address, address, sigdigits) &&
		    rt->sigdigits == sigdigits && rt->dev == dev) {
			__x25_remove_route(rt);
			rc = 0;
			break;
		}
	}

	write_unlock_bh(&x25_route_list_lock);
	return rc;
}

/*
 *	A device has been removed, remove its routes.
 */
void x25_route_device_down(struct net_device *dev)
{
	struct x25_route *rt;
	struct list_head *entry, *tmp;

	write_lock_bh(&x25_route_list_lock);

	list_for_each_safe(entry, tmp, &x25_route_list) {
		rt = list_entry(entry, struct x25_route, node);

		if (rt->dev == dev)
			__x25_remove_route(rt);
	}
	write_unlock_bh(&x25_route_list_lock);
}

/*
 *	Check that the device given is a valid X.25 interface that is "up".
 */
struct net_device *x25_dev_get(char *devname)
{
	struct net_device *dev = dev_get_by_name(devname);

	if (dev &&
	    (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25
#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
					&& dev->type != ARPHRD_ETHER
#endif
					)))
		dev_put(dev);

	return dev;
}

/**
 * 	x25_get_route -	Find a route given an X.25 address.
 * 	@addr - address to find a route for
 *
 * 	Find a route given an X.25 address.
 */
struct x25_route *x25_get_route(struct x25_address *addr)
{
	struct x25_route *rt, *use = NULL;
	struct list_head *entry;

	read_lock_bh(&x25_route_list_lock);

	list_for_each(entry, &x25_route_list) {
		rt = list_entry(entry, struct x25_route, node);

		if (!memcmp(&rt->address, addr, rt->sigdigits)) {
			if (!use)
				use = rt;
			else if (rt->sigdigits > use->sigdigits)
				use = rt;
		}
	}

	if (use)
		x25_route_hold(use);

	read_unlock_bh(&x25_route_list_lock);
	return use;
}

/*
 *	Handle the ioctls that control the routing functions.
 */
int x25_route_ioctl(unsigned int cmd, void __user *arg)
{
	struct x25_route_struct rt;
	struct net_device *dev;
	int rc = -EINVAL;

	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
		goto out;

	rc = -EFAULT;
	if (copy_from_user(&rt, arg, sizeof(rt)))
		goto out;

	rc = -EINVAL;
	if (rt.sigdigits < 0 || rt.sigdigits > 15)
		goto out;

	dev = x25_dev_get(rt.device);
	if (!dev)
		goto out;

	if (cmd == SIOCADDRT)
		rc = x25_add_route(&rt.address, rt.sigdigits, dev);
	else
		rc = x25_del_route(&rt.address, rt.sigdigits, dev);
	dev_put(dev);
out:
	return rc;
}

/*
 *	Release all memory associated with X.25 routing structures.
 */
void __exit x25_route_free(void)
{
	struct x25_route *rt;
	struct list_head *entry, *tmp;

	write_lock_bh(&x25_route_list_lock);
	list_for_each_safe(entry, tmp, &x25_route_list) {
		rt = list_entry(entry, struct x25_route, node);
		__x25_remove_route(rt);
	}
	write_unlock_bh(&x25_route_list_lock);
}