x25_route.c revision f8e1d20183bf56f889d60edadd48f54912b9277f 
1/*
2 *	X.25 Packet Layer release 002
3 *
4 *	This is ALPHA test software. This code may break your machine,
5 *	randomly fail to work with new releases, misbehave and/or generally
6 *	screw up. It might even work.
7 *
8 *	This code REQUIRES 2.1.15 or higher
9 *
10 *	This module:
11 *		This module is free software; you can redistribute it and/or
12 *		modify it under the terms of the GNU General Public License
13 *		as published by the Free Software Foundation; either version
14 *		2 of the License, or (at your option) any later version.
15 *
16 *	History
17 *	X.25 001	Jonathan Naylor	Started coding.
18 */
19
20#include <linux/if_arp.h>
21#include <linux/init.h>
22#include <net/x25.h>
23
24struct list_head x25_route_list = LIST_HEAD_INIT(x25_route_list);
25DEFINE_RWLOCK(x25_route_list_lock);
26
27/*
28 *	Add a new route.
29 */
30static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
31			 struct net_device *dev)
32{
33	struct x25_route *rt;
34	struct list_head *entry;
35	int rc = -EINVAL;
36
37	write_lock_bh(&x25_route_list_lock);
38
39	list_for_each(entry, &x25_route_list) {
40		rt = list_entry(entry, struct x25_route, node);
41
42		if (!memcmp(&rt->address, address, sigdigits) &&
43		    rt->sigdigits == sigdigits)
44			goto out;
45	}
46
47	rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
48	rc = -ENOMEM;
49	if (!rt)
50		goto out;
51
52	strcpy(rt->address.x25_addr, "000000000000000");
53	memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);
54
55	rt->sigdigits = sigdigits;
56	rt->dev       = dev;
57	atomic_set(&rt->refcnt, 1);
58
59	list_add(&rt->node, &x25_route_list);
60	rc = 0;
61out:
62	write_unlock_bh(&x25_route_list_lock);
63	return rc;
64}
65
66/**
67 * __x25_remove_route - remove route from x25_route_list
68 * @rt - route to remove
69 *
70 * Remove route from x25_route_list. If it was there.
71 * Caller must hold x25_route_list_lock.
72 */
73static void __x25_remove_route(struct x25_route *rt)
74{
75	if (rt->node.next) {
76		list_del(&rt->node);
77		x25_route_put(rt);
78	}
79}
80
81static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
82			 struct net_device *dev)
83{
84	struct x25_route *rt;
85	struct list_head *entry;
86	int rc = -EINVAL;
87
88	write_lock_bh(&x25_route_list_lock);
89
90	list_for_each(entry, &x25_route_list) {
91		rt = list_entry(entry, struct x25_route, node);
92
93		if (!memcmp(&rt->address, address, sigdigits) &&
94		    rt->sigdigits == sigdigits && rt->dev == dev) {
95			__x25_remove_route(rt);
96			rc = 0;
97			break;
98		}
99	}
100
101	write_unlock_bh(&x25_route_list_lock);
102	return rc;
103}
104
105/*
106 *	A device has been removed, remove its routes.
107 */
108void x25_route_device_down(struct net_device *dev)
109{
110	struct x25_route *rt;
111	struct list_head *entry, *tmp;
112
113	write_lock_bh(&x25_route_list_lock);
114
115	list_for_each_safe(entry, tmp, &x25_route_list) {
116		rt = list_entry(entry, struct x25_route, node);
117
118		if (rt->dev == dev)
119			__x25_remove_route(rt);
120	}
121	write_unlock_bh(&x25_route_list_lock);
122
123	/* Remove any related forwarding */
124	x25_clear_forward_by_dev(dev);
125}
126
127/*
128 *	Check that the device given is a valid X.25 interface that is "up".
129 */
130struct net_device *x25_dev_get(char *devname)
131{
132	struct net_device *dev = dev_get_by_name(devname);
133
134	if (dev &&
135	    (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25
136#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
137					&& dev->type != ARPHRD_ETHER
138#endif
139					)))
140		dev_put(dev);
141
142	return dev;
143}
144
145/**
146 * 	x25_get_route -	Find a route given an X.25 address.
147 * 	@addr - address to find a route for
148 *
149 * 	Find a route given an X.25 address.
150 */
151struct x25_route *x25_get_route(struct x25_address *addr)
152{
153	struct x25_route *rt, *use = NULL;
154	struct list_head *entry;
155
156	read_lock_bh(&x25_route_list_lock);
157
158	list_for_each(entry, &x25_route_list) {
159		rt = list_entry(entry, struct x25_route, node);
160
161		if (!memcmp(&rt->address, addr, rt->sigdigits)) {
162			if (!use)
163				use = rt;
164			else if (rt->sigdigits > use->sigdigits)
165				use = rt;
166		}
167	}
168
169	if (use)
170		x25_route_hold(use);
171
172	read_unlock_bh(&x25_route_list_lock);
173	return use;
174}
175
176/*
177 *	Handle the ioctls that control the routing functions.
178 */
179int x25_route_ioctl(unsigned int cmd, void __user *arg)
180{
181	struct x25_route_struct rt;
182	struct net_device *dev;
183	int rc = -EINVAL;
184
185	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
186		goto out;
187
188	rc = -EFAULT;
189	if (copy_from_user(&rt, arg, sizeof(rt)))
190		goto out;
191
192	rc = -EINVAL;
193	if (rt.sigdigits < 0 || rt.sigdigits > 15)
194		goto out;
195
196	dev = x25_dev_get(rt.device);
197	if (!dev)
198		goto out;
199
200	if (cmd == SIOCADDRT)
201		rc = x25_add_route(&rt.address, rt.sigdigits, dev);
202	else
203		rc = x25_del_route(&rt.address, rt.sigdigits, dev);
204	dev_put(dev);
205out:
206	return rc;
207}
208
209/*
210 *	Release all memory associated with X.25 routing structures.
211 */
212void __exit x25_route_free(void)
213{
214	struct x25_route *rt;
215	struct list_head *entry, *tmp;
216
217	write_lock_bh(&x25_route_list_lock);
218	list_for_each_safe(entry, tmp, &x25_route_list) {
219		rt = list_entry(entry, struct x25_route, node);
220		__x25_remove_route(rt);
221	}
222	write_unlock_bh(&x25_route_list_lock);
223}
224