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 <linux/slab.h>
23#include <net/x25.h>
24
25LIST_HEAD(x25_route_list);
26DEFINE_RWLOCK(x25_route_list_lock);
27
28/*
29 *	Add a new route.
30 */
31static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
32			 struct net_device *dev)
33{
34	struct x25_route *rt;
35	struct list_head *entry;
36	int rc = -EINVAL;
37
38	write_lock_bh(&x25_route_list_lock);
39
40	list_for_each(entry, &x25_route_list) {
41		rt = list_entry(entry, struct x25_route, node);
42
43		if (!memcmp(&rt->address, address, sigdigits) &&
44		    rt->sigdigits == sigdigits)
45			goto out;
46	}
47
48	rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
49	rc = -ENOMEM;
50	if (!rt)
51		goto out;
52
53	strcpy(rt->address.x25_addr, "000000000000000");
54	memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);
55
56	rt->sigdigits = sigdigits;
57	rt->dev       = dev;
58	atomic_set(&rt->refcnt, 1);
59
60	list_add(&rt->node, &x25_route_list);
61	rc = 0;
62out:
63	write_unlock_bh(&x25_route_list_lock);
64	return rc;
65}
66
67/**
68 * __x25_remove_route - remove route from x25_route_list
69 * @rt - route to remove
70 *
71 * Remove route from x25_route_list. If it was there.
72 * Caller must hold x25_route_list_lock.
73 */
74static void __x25_remove_route(struct x25_route *rt)
75{
76	if (rt->node.next) {
77		list_del(&rt->node);
78		x25_route_put(rt);
79	}
80}
81
82static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
83			 struct net_device *dev)
84{
85	struct x25_route *rt;
86	struct list_head *entry;
87	int rc = -EINVAL;
88
89	write_lock_bh(&x25_route_list_lock);
90
91	list_for_each(entry, &x25_route_list) {
92		rt = list_entry(entry, struct x25_route, node);
93
94		if (!memcmp(&rt->address, address, sigdigits) &&
95		    rt->sigdigits == sigdigits && rt->dev == dev) {
96			__x25_remove_route(rt);
97			rc = 0;
98			break;
99		}
100	}
101
102	write_unlock_bh(&x25_route_list_lock);
103	return rc;
104}
105
106/*
107 *	A device has been removed, remove its routes.
108 */
109void x25_route_device_down(struct net_device *dev)
110{
111	struct x25_route *rt;
112	struct list_head *entry, *tmp;
113
114	write_lock_bh(&x25_route_list_lock);
115
116	list_for_each_safe(entry, tmp, &x25_route_list) {
117		rt = list_entry(entry, struct x25_route, node);
118
119		if (rt->dev == dev)
120			__x25_remove_route(rt);
121	}
122	write_unlock_bh(&x25_route_list_lock);
123
124	/* Remove any related forwarding */
125	x25_clear_forward_by_dev(dev);
126}
127
128/*
129 *	Check that the device given is a valid X.25 interface that is "up".
130 */
131struct net_device *x25_dev_get(char *devname)
132{
133	struct net_device *dev = dev_get_by_name(&init_net, devname);
134
135	if (dev &&
136	    (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25
137#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
138					&& dev->type != ARPHRD_ETHER
139#endif
140					))){
141		dev_put(dev);
142		dev = NULL;
143	}
144
145	return dev;
146}
147
148/**
149 * 	x25_get_route -	Find a route given an X.25 address.
150 * 	@addr - address to find a route for
151 *
152 * 	Find a route given an X.25 address.
153 */
154struct x25_route *x25_get_route(struct x25_address *addr)
155{
156	struct x25_route *rt, *use = NULL;
157	struct list_head *entry;
158
159	read_lock_bh(&x25_route_list_lock);
160
161	list_for_each(entry, &x25_route_list) {
162		rt = list_entry(entry, struct x25_route, node);
163
164		if (!memcmp(&rt->address, addr, rt->sigdigits)) {
165			if (!use)
166				use = rt;
167			else if (rt->sigdigits > use->sigdigits)
168				use = rt;
169		}
170	}
171
172	if (use)
173		x25_route_hold(use);
174
175	read_unlock_bh(&x25_route_list_lock);
176	return use;
177}
178
179/*
180 *	Handle the ioctls that control the routing functions.
181 */
182int x25_route_ioctl(unsigned int cmd, void __user *arg)
183{
184	struct x25_route_struct rt;
185	struct net_device *dev;
186	int rc = -EINVAL;
187
188	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
189		goto out;
190
191	rc = -EFAULT;
192	if (copy_from_user(&rt, arg, sizeof(rt)))
193		goto out;
194
195	rc = -EINVAL;
196	if (rt.sigdigits > 15)
197		goto out;
198
199	dev = x25_dev_get(rt.device);
200	if (!dev)
201		goto out;
202
203	if (cmd == SIOCADDRT)
204		rc = x25_add_route(&rt.address, rt.sigdigits, dev);
205	else
206		rc = x25_del_route(&rt.address, rt.sigdigits, dev);
207	dev_put(dev);
208out:
209	return rc;
210}
211
212/*
213 *	Release all memory associated with X.25 routing structures.
214 */
215void __exit x25_route_free(void)
216{
217	struct x25_route *rt;
218	struct list_head *entry, *tmp;
219
220	write_lock_bh(&x25_route_list_lock);
221	list_for_each_safe(entry, tmp, &x25_route_list) {
222		rt = list_entry(entry, struct x25_route, node);
223		__x25_remove_route(rt);
224	}
225	write_unlock_bh(&x25_route_list_lock);
226}
227