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
55static int open_count;
56
57static const struct header_ops lowpan_header_ops = {
58	.create	= lowpan_header_create,
59};
60
61static int lowpan_dev_init(struct net_device *ldev)
62{
63	netdev_lockdep_set_classes(ldev);
64
65	return 0;
66}
67
68static int lowpan_open(struct net_device *dev)
69{
70	if (!open_count)
71		lowpan_rx_init();
72	open_count++;
73	return 0;
74}
75
76static int lowpan_stop(struct net_device *dev)
77{
78	open_count--;
79	if (!open_count)
80		lowpan_rx_exit();
81	return 0;
82}
83
84static int lowpan_neigh_construct(struct net_device *dev, struct neighbour *n)
85{
86	struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
87
88	/* default no short_addr is available for a neighbour */
89	neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
90	return 0;
91}
92
93static int lowpan_get_iflink(const struct net_device *dev)
94{
95	return lowpan_802154_dev(dev)->wdev->ifindex;
96}
97
98static const struct net_device_ops lowpan_netdev_ops = {
99	.ndo_init		= lowpan_dev_init,
100	.ndo_start_xmit		= lowpan_xmit,
101	.ndo_open		= lowpan_open,
102	.ndo_stop		= lowpan_stop,
103	.ndo_neigh_construct    = lowpan_neigh_construct,
104	.ndo_get_iflink         = lowpan_get_iflink,
105};
106
107static void lowpan_setup(struct net_device *ldev)
108{
109	memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
110	/* We need an ipv6hdr as minimum len when calling xmit */
111	ldev->hard_header_len	= sizeof(struct ipv6hdr);
112	ldev->flags		= IFF_BROADCAST | IFF_MULTICAST;
113	ldev->priv_flags	|= IFF_NO_QUEUE;
114
115	ldev->netdev_ops	= &lowpan_netdev_ops;
116	ldev->header_ops	= &lowpan_header_ops;
117	ldev->needs_free_netdev	= true;
118	ldev->features		|= NETIF_F_NETNS_LOCAL;
119}
120
121static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
122			   struct netlink_ext_ack *extack)
123{
124	if (tb[IFLA_ADDRESS]) {
125		if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
126			return -EINVAL;
127	}
128	return 0;
129}
130
131static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
132			  struct nlattr *tb[], struct nlattr *data[],
133			  struct netlink_ext_ack *extack)
134{
135	struct net_device *wdev;
136	int ret;
137
138	ASSERT_RTNL();
139
140	pr_debug("adding new link\n");
141
142	if (!tb[IFLA_LINK])
143		return -EINVAL;
144	/* find and hold wpan device */
145	wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
146	if (!wdev)
147		return -ENODEV;
148	if (wdev->type != ARPHRD_IEEE802154) {
149		dev_put(wdev);
150		return -EINVAL;
151	}
152
153	if (wdev->ieee802154_ptr->lowpan_dev) {
154		dev_put(wdev);
155		return -EBUSY;
156	}
157
158	lowpan_802154_dev(ldev)->wdev = wdev;
159	/* Set the lowpan hardware address to the wpan hardware address. */
160	memcpy(ldev->dev_addr, wdev->dev_addr, IEEE802154_ADDR_LEN);
161	/* We need headroom for possible wpan_dev_hard_header call and tailroom
162	 * for encryption/fcs handling. The lowpan interface will replace
163	 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
164	 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
165	 * header.
166	 */
167	ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
168				wdev->needed_headroom;
169	ldev->needed_tailroom = wdev->needed_tailroom;
170
171	ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
172
173	ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
174	if (ret < 0) {
175		dev_put(wdev);
176		return ret;
177	}
178
179	wdev->ieee802154_ptr->lowpan_dev = ldev;
180	return 0;
181}
182
183static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
184{
185	struct net_device *wdev = lowpan_802154_dev(ldev)->wdev;
186
187	ASSERT_RTNL();
188
189	wdev->ieee802154_ptr->lowpan_dev = NULL;
190	lowpan_unregister_netdevice(ldev);
191	dev_put(wdev);
192}
193
194static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
195	.kind		= "lowpan",
196	.priv_size	= LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)),
197	.setup		= lowpan_setup,
198	.newlink	= lowpan_newlink,
199	.dellink	= lowpan_dellink,
200	.validate	= lowpan_validate,
201};
202
203static inline int __init lowpan_netlink_init(void)
204{
205	return rtnl_link_register(&lowpan_link_ops);
206}
207
208static inline void lowpan_netlink_fini(void)
209{
210	rtnl_link_unregister(&lowpan_link_ops);
211}
212
213static int lowpan_device_event(struct notifier_block *unused,
214			       unsigned long event, void *ptr)
215{
216	struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
217	struct wpan_dev *wpan_dev;
218
219	if (ndev->type != ARPHRD_IEEE802154)
220		return NOTIFY_DONE;
221	wpan_dev = ndev->ieee802154_ptr;
222	if (!wpan_dev)
223		return NOTIFY_DONE;
224
225	switch (event) {
226	case NETDEV_UNREGISTER:
227		/* Check if wpan interface is unregistered that we
228		 * also delete possible lowpan interfaces which belongs
229		 * to the wpan interface.
230		 */
231		if (wpan_dev->lowpan_dev)
232			lowpan_dellink(wpan_dev->lowpan_dev, NULL);
233		break;
234	default:
235		return NOTIFY_DONE;
236	}
237
238	return NOTIFY_OK;
239}
240
241static struct notifier_block lowpan_dev_notifier = {
242	.notifier_call = lowpan_device_event,
243};
244
245static int __init lowpan_init_module(void)
246{
247	int err = 0;
248
249	err = lowpan_net_frag_init();
250	if (err < 0)
251		goto out;
252
253	err = lowpan_netlink_init();
254	if (err < 0)
255		goto out_frag;
256
257	err = register_netdevice_notifier(&lowpan_dev_notifier);
258	if (err < 0)
259		goto out_pack;
260
261	return 0;
262
263out_pack:
264	lowpan_netlink_fini();
265out_frag:
266	lowpan_net_frag_exit();
267out:
268	return err;
269}
270
271static void __exit lowpan_cleanup_module(void)
272{
273	lowpan_netlink_fini();
274
275	lowpan_net_frag_exit();
276
277	unregister_netdevice_notifier(&lowpan_dev_notifier);
278}
279
280module_init(lowpan_init_module);
281module_exit(lowpan_cleanup_module);
282MODULE_LICENSE("GPL");
283MODULE_ALIAS_RTNL_LINK("lowpan");
284