1/* Copyright 2011, Siemens AG
2 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
3 */
4
5/* Based on patches from Jon Smirl <jonsmirl@gmail.com>
6 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2
10 * as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17
18/* Jon's code is based on 6lowpan implementation for Contiki which is:
19 * Copyright (c) 2008, Swedish Institute of Computer Science.
20 * All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. Neither the name of the Institute nor the names of its contributors
31 *    may be used to endorse or promote products derived from this software
32 *    without specific prior written permission.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 */
46
47#include <linux/module.h>
48#include <linux/netdevice.h>
49#include <linux/ieee802154.h>
50
51#include <net/ipv6.h>
52
53#include "6lowpan_i.h"
54
55LIST_HEAD(lowpan_devices);
56static int lowpan_open_count;
57
58static __le16 lowpan_get_pan_id(const struct net_device *dev)
59{
60	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
61
62	return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
63}
64
65static __le16 lowpan_get_short_addr(const struct net_device *dev)
66{
67	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
68
69	return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
70}
71
72static u8 lowpan_get_dsn(const struct net_device *dev)
73{
74	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
75
76	return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
77}
78
79static struct header_ops lowpan_header_ops = {
80	.create	= lowpan_header_create,
81};
82
83static struct lock_class_key lowpan_tx_busylock;
84static struct lock_class_key lowpan_netdev_xmit_lock_key;
85
86static void lowpan_set_lockdep_class_one(struct net_device *dev,
87					 struct netdev_queue *txq,
88					 void *_unused)
89{
90	lockdep_set_class(&txq->_xmit_lock,
91			  &lowpan_netdev_xmit_lock_key);
92}
93
94static int lowpan_dev_init(struct net_device *dev)
95{
96	netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
97	dev->qdisc_tx_busylock = &lowpan_tx_busylock;
98	return 0;
99}
100
101static const struct net_device_ops lowpan_netdev_ops = {
102	.ndo_init		= lowpan_dev_init,
103	.ndo_start_xmit		= lowpan_xmit,
104};
105
106static struct ieee802154_mlme_ops lowpan_mlme = {
107	.get_pan_id = lowpan_get_pan_id,
108	.get_short_addr = lowpan_get_short_addr,
109	.get_dsn = lowpan_get_dsn,
110};
111
112static void lowpan_setup(struct net_device *dev)
113{
114	dev->addr_len		= IEEE802154_ADDR_LEN;
115	memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
116	dev->type		= ARPHRD_6LOWPAN;
117	/* Frame Control + Sequence Number + Address fields + Security Header */
118	dev->hard_header_len	= 2 + 1 + 20 + 14;
119	dev->needed_tailroom	= 2; /* FCS */
120	dev->mtu		= IPV6_MIN_MTU;
121	dev->tx_queue_len	= 0;
122	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
123	dev->watchdog_timeo	= 0;
124
125	dev->netdev_ops		= &lowpan_netdev_ops;
126	dev->header_ops		= &lowpan_header_ops;
127	dev->ml_priv		= &lowpan_mlme;
128	dev->destructor		= free_netdev;
129	dev->features		|= NETIF_F_NETNS_LOCAL;
130}
131
132static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
133{
134	if (tb[IFLA_ADDRESS]) {
135		if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
136			return -EINVAL;
137	}
138	return 0;
139}
140
141static int lowpan_newlink(struct net *src_net, struct net_device *dev,
142			  struct nlattr *tb[], struct nlattr *data[])
143{
144	struct net_device *real_dev;
145	struct lowpan_dev_record *entry;
146	int ret;
147
148	ASSERT_RTNL();
149
150	pr_debug("adding new link\n");
151
152	if (!tb[IFLA_LINK] ||
153	    !net_eq(dev_net(dev), &init_net))
154		return -EINVAL;
155	/* find and hold real wpan device */
156	real_dev = dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
157	if (!real_dev)
158		return -ENODEV;
159	if (real_dev->type != ARPHRD_IEEE802154) {
160		dev_put(real_dev);
161		return -EINVAL;
162	}
163
164	lowpan_dev_info(dev)->real_dev = real_dev;
165	mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
166
167	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
168	if (!entry) {
169		dev_put(real_dev);
170		lowpan_dev_info(dev)->real_dev = NULL;
171		return -ENOMEM;
172	}
173
174	entry->ldev = dev;
175
176	/* Set the lowpan hardware address to the wpan hardware address. */
177	memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
178
179	mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
180	INIT_LIST_HEAD(&entry->list);
181	list_add_tail(&entry->list, &lowpan_devices);
182	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
183
184	ret = register_netdevice(dev);
185	if (ret >= 0) {
186		if (!lowpan_open_count)
187			lowpan_rx_init();
188		lowpan_open_count++;
189	}
190
191	return ret;
192}
193
194static void lowpan_dellink(struct net_device *dev, struct list_head *head)
195{
196	struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
197	struct net_device *real_dev = lowpan_dev->real_dev;
198	struct lowpan_dev_record *entry, *tmp;
199
200	ASSERT_RTNL();
201
202	lowpan_open_count--;
203	if (!lowpan_open_count)
204		lowpan_rx_exit();
205
206	mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
207	list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
208		if (entry->ldev == dev) {
209			list_del(&entry->list);
210			kfree(entry);
211		}
212	}
213	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
214
215	mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
216
217	unregister_netdevice_queue(dev, head);
218
219	dev_put(real_dev);
220}
221
222static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
223	.kind		= "lowpan",
224	.priv_size	= sizeof(struct lowpan_dev_info),
225	.setup		= lowpan_setup,
226	.newlink	= lowpan_newlink,
227	.dellink	= lowpan_dellink,
228	.validate	= lowpan_validate,
229};
230
231static inline int __init lowpan_netlink_init(void)
232{
233	return rtnl_link_register(&lowpan_link_ops);
234}
235
236static inline void lowpan_netlink_fini(void)
237{
238	rtnl_link_unregister(&lowpan_link_ops);
239}
240
241static int lowpan_device_event(struct notifier_block *unused,
242			       unsigned long event, void *ptr)
243{
244	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
245	LIST_HEAD(del_list);
246	struct lowpan_dev_record *entry, *tmp;
247
248	if (dev->type != ARPHRD_IEEE802154)
249		goto out;
250
251	if (event == NETDEV_UNREGISTER) {
252		list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
253			if (lowpan_dev_info(entry->ldev)->real_dev == dev)
254				lowpan_dellink(entry->ldev, &del_list);
255		}
256
257		unregister_netdevice_many(&del_list);
258	}
259
260out:
261	return NOTIFY_DONE;
262}
263
264static struct notifier_block lowpan_dev_notifier = {
265	.notifier_call = lowpan_device_event,
266};
267
268static int __init lowpan_init_module(void)
269{
270	int err = 0;
271
272	err = lowpan_net_frag_init();
273	if (err < 0)
274		goto out;
275
276	err = lowpan_netlink_init();
277	if (err < 0)
278		goto out_frag;
279
280	err = register_netdevice_notifier(&lowpan_dev_notifier);
281	if (err < 0)
282		goto out_pack;
283
284	return 0;
285
286out_pack:
287	lowpan_netlink_fini();
288out_frag:
289	lowpan_net_frag_exit();
290out:
291	return err;
292}
293
294static void __exit lowpan_cleanup_module(void)
295{
296	lowpan_netlink_fini();
297
298	lowpan_net_frag_exit();
299
300	unregister_netdevice_notifier(&lowpan_dev_notifier);
301}
302
303module_init(lowpan_init_module);
304module_exit(lowpan_cleanup_module);
305MODULE_LICENSE("GPL");
306MODULE_ALIAS_RTNL_LINK("lowpan");
307