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 #include <linux/if_arp.h>
51
52 #include <net/ipv6.h>
53 #include <net/netdev_lock.h>
54
55 #include "6lowpan_i.h"
56
57 static int open_count;
58
59 static const struct header_ops lowpan_header_ops = {
60 .create = lowpan_header_create,
61 };
62
lowpan_dev_init(struct net_device * ldev)63 static int lowpan_dev_init(struct net_device *ldev)
64 {
65 netdev_lockdep_set_classes(ldev);
66
67 return 0;
68 }
69
lowpan_open(struct net_device * dev)70 static int lowpan_open(struct net_device *dev)
71 {
72 if (!open_count)
73 lowpan_rx_init();
74 open_count++;
75 return 0;
76 }
77
lowpan_stop(struct net_device * dev)78 static int lowpan_stop(struct net_device *dev)
79 {
80 open_count--;
81 if (!open_count)
82 lowpan_rx_exit();
83 return 0;
84 }
85
lowpan_neigh_construct(struct net_device * dev,struct neighbour * n)86 static int lowpan_neigh_construct(struct net_device *dev, struct neighbour *n)
87 {
88 struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
89
90 /* default no short_addr is available for a neighbour */
91 neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
92 return 0;
93 }
94
lowpan_get_iflink(const struct net_device * dev)95 static int lowpan_get_iflink(const struct net_device *dev)
96 {
97 return READ_ONCE(lowpan_802154_dev(dev)->wdev->ifindex);
98 }
99
100 static const struct net_device_ops lowpan_netdev_ops = {
101 .ndo_init = lowpan_dev_init,
102 .ndo_start_xmit = lowpan_xmit,
103 .ndo_open = lowpan_open,
104 .ndo_stop = lowpan_stop,
105 .ndo_neigh_construct = lowpan_neigh_construct,
106 .ndo_get_iflink = lowpan_get_iflink,
107 };
108
lowpan_setup(struct net_device * ldev)109 static void lowpan_setup(struct net_device *ldev)
110 {
111 memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
112 /* We need an ipv6hdr as minimum len when calling xmit */
113 ldev->hard_header_len = sizeof(struct ipv6hdr);
114 ldev->flags = IFF_BROADCAST | IFF_MULTICAST;
115 ldev->priv_flags |= IFF_NO_QUEUE;
116
117 ldev->netdev_ops = &lowpan_netdev_ops;
118 ldev->header_ops = &lowpan_header_ops;
119 ldev->needs_free_netdev = true;
120 ldev->netns_immutable = true;
121 }
122
lowpan_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)123 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
124 struct netlink_ext_ack *extack)
125 {
126 if (tb[IFLA_ADDRESS]) {
127 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
128 return -EINVAL;
129 }
130 return 0;
131 }
132
lowpan_newlink(struct net_device * ldev,struct rtnl_newlink_params * params,struct netlink_ext_ack * extack)133 static int lowpan_newlink(struct net_device *ldev,
134 struct rtnl_newlink_params *params,
135 struct netlink_ext_ack *extack)
136 {
137 struct nlattr **tb = params->tb;
138 struct net_device *wdev;
139 int ret;
140
141 ASSERT_RTNL();
142
143 pr_debug("adding new link\n");
144
145 if (!tb[IFLA_LINK])
146 return -EINVAL;
147 if (params->link_net && !net_eq(params->link_net, dev_net(ldev)))
148 return -EINVAL;
149 /* find and hold wpan device */
150 wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
151 if (!wdev)
152 return -ENODEV;
153 if (wdev->type != ARPHRD_IEEE802154) {
154 dev_put(wdev);
155 return -EINVAL;
156 }
157
158 if (wdev->ieee802154_ptr->lowpan_dev) {
159 dev_put(wdev);
160 return -EBUSY;
161 }
162
163 lowpan_802154_dev(ldev)->wdev = wdev;
164 /* Set the lowpan hardware address to the wpan hardware address. */
165 __dev_addr_set(ldev, wdev->dev_addr, IEEE802154_ADDR_LEN);
166 /* We need headroom for possible wpan_dev_hard_header call and tailroom
167 * for encryption/fcs handling. The lowpan interface will replace
168 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
169 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
170 * header.
171 */
172 ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
173 wdev->needed_headroom;
174 ldev->needed_tailroom = wdev->needed_tailroom;
175
176 ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
177
178 ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
179 if (ret < 0) {
180 dev_put(wdev);
181 return ret;
182 }
183
184 wdev->ieee802154_ptr->lowpan_dev = ldev;
185 return 0;
186 }
187
lowpan_dellink(struct net_device * ldev,struct list_head * head)188 static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
189 {
190 struct net_device *wdev = lowpan_802154_dev(ldev)->wdev;
191
192 ASSERT_RTNL();
193
194 wdev->ieee802154_ptr->lowpan_dev = NULL;
195 lowpan_unregister_netdevice(ldev);
196 dev_put(wdev);
197 }
198
199 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
200 .kind = "lowpan",
201 .priv_size = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)),
202 .setup = lowpan_setup,
203 .newlink = lowpan_newlink,
204 .dellink = lowpan_dellink,
205 .validate = lowpan_validate,
206 };
207
lowpan_netlink_init(void)208 static inline int __init lowpan_netlink_init(void)
209 {
210 return rtnl_link_register(&lowpan_link_ops);
211 }
212
lowpan_netlink_fini(void)213 static inline void lowpan_netlink_fini(void)
214 {
215 rtnl_link_unregister(&lowpan_link_ops);
216 }
217
lowpan_device_event(struct notifier_block * unused,unsigned long event,void * ptr)218 static int lowpan_device_event(struct notifier_block *unused,
219 unsigned long event, void *ptr)
220 {
221 struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
222 struct wpan_dev *wpan_dev;
223
224 if (ndev->type != ARPHRD_IEEE802154)
225 return NOTIFY_DONE;
226 wpan_dev = ndev->ieee802154_ptr;
227 if (!wpan_dev)
228 return NOTIFY_DONE;
229
230 switch (event) {
231 case NETDEV_UNREGISTER:
232 /* Check if wpan interface is unregistered that we
233 * also delete possible lowpan interfaces which belongs
234 * to the wpan interface.
235 */
236 if (wpan_dev->lowpan_dev)
237 lowpan_dellink(wpan_dev->lowpan_dev, NULL);
238 break;
239 default:
240 return NOTIFY_DONE;
241 }
242
243 return NOTIFY_OK;
244 }
245
246 static struct notifier_block lowpan_dev_notifier = {
247 .notifier_call = lowpan_device_event,
248 };
249
lowpan_init_module(void)250 static int __init lowpan_init_module(void)
251 {
252 int err = 0;
253
254 err = lowpan_net_frag_init();
255 if (err < 0)
256 goto out;
257
258 err = lowpan_netlink_init();
259 if (err < 0)
260 goto out_frag;
261
262 err = register_netdevice_notifier(&lowpan_dev_notifier);
263 if (err < 0)
264 goto out_pack;
265
266 return 0;
267
268 out_pack:
269 lowpan_netlink_fini();
270 out_frag:
271 lowpan_net_frag_exit();
272 out:
273 return err;
274 }
275
lowpan_cleanup_module(void)276 static void __exit lowpan_cleanup_module(void)
277 {
278 lowpan_netlink_fini();
279
280 lowpan_net_frag_exit();
281
282 unregister_netdevice_notifier(&lowpan_dev_notifier);
283 }
284
285 module_init(lowpan_init_module);
286 module_exit(lowpan_cleanup_module);
287 MODULE_DESCRIPTION("IPv6 over Low power Wireless Personal Area Network IEEE 802.15.4 core");
288 MODULE_LICENSE("GPL");
289 MODULE_ALIAS_RTNL_LINK("lowpan");
290