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
55 static int open_count;
56
57 static const struct header_ops lowpan_header_ops = {
58 .create = lowpan_header_create,
59 };
60
lowpan_dev_init(struct net_device * ldev)61 static int lowpan_dev_init(struct net_device *ldev)
62 {
63 netdev_lockdep_set_classes(ldev);
64
65 return 0;
66 }
67
lowpan_open(struct net_device * dev)68 static int lowpan_open(struct net_device *dev)
69 {
70 if (!open_count)
71 lowpan_rx_init();
72 open_count++;
73 return 0;
74 }
75
lowpan_stop(struct net_device * dev)76 static int lowpan_stop(struct net_device *dev)
77 {
78 open_count--;
79 if (!open_count)
80 lowpan_rx_exit();
81 return 0;
82 }
83
lowpan_neigh_construct(struct net_device * dev,struct neighbour * n)84 static 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
lowpan_get_iflink(const struct net_device * dev)93 static int lowpan_get_iflink(const struct net_device *dev)
94 {
95 return lowpan_802154_dev(dev)->wdev->ifindex;
96 }
97
98 static 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
lowpan_setup(struct net_device * ldev)107 static 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
114 ldev->netdev_ops = &lowpan_netdev_ops;
115 ldev->header_ops = &lowpan_header_ops;
116 ldev->needs_free_netdev = true;
117 ldev->features |= NETIF_F_NETNS_LOCAL;
118 }
119
lowpan_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)120 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
121 struct netlink_ext_ack *extack)
122 {
123 if (tb[IFLA_ADDRESS]) {
124 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
125 return -EINVAL;
126 }
127 return 0;
128 }
129
lowpan_newlink(struct net * src_net,struct net_device * ldev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)130 static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
131 struct nlattr *tb[], struct nlattr *data[],
132 struct netlink_ext_ack *extack)
133 {
134 struct net_device *wdev;
135 int ret;
136
137 ASSERT_RTNL();
138
139 pr_debug("adding new link\n");
140
141 if (!tb[IFLA_LINK])
142 return -EINVAL;
143 /* find and hold wpan device */
144 wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
145 if (!wdev)
146 return -ENODEV;
147 if (wdev->type != ARPHRD_IEEE802154) {
148 dev_put(wdev);
149 return -EINVAL;
150 }
151
152 if (wdev->ieee802154_ptr->lowpan_dev) {
153 dev_put(wdev);
154 return -EBUSY;
155 }
156
157 lowpan_802154_dev(ldev)->wdev = wdev;
158 /* Set the lowpan hardware address to the wpan hardware address. */
159 memcpy(ldev->dev_addr, wdev->dev_addr, IEEE802154_ADDR_LEN);
160 /* We need headroom for possible wpan_dev_hard_header call and tailroom
161 * for encryption/fcs handling. The lowpan interface will replace
162 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
163 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
164 * header.
165 */
166 ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
167 wdev->needed_headroom;
168 ldev->needed_tailroom = wdev->needed_tailroom;
169
170 ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
171
172 ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
173 if (ret < 0) {
174 dev_put(wdev);
175 return ret;
176 }
177
178 wdev->ieee802154_ptr->lowpan_dev = ldev;
179 return 0;
180 }
181
lowpan_dellink(struct net_device * ldev,struct list_head * head)182 static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
183 {
184 struct net_device *wdev = lowpan_802154_dev(ldev)->wdev;
185
186 ASSERT_RTNL();
187
188 wdev->ieee802154_ptr->lowpan_dev = NULL;
189 lowpan_unregister_netdevice(ldev);
190 dev_put(wdev);
191 }
192
193 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
194 .kind = "lowpan",
195 .priv_size = LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)),
196 .setup = lowpan_setup,
197 .newlink = lowpan_newlink,
198 .dellink = lowpan_dellink,
199 .validate = lowpan_validate,
200 };
201
lowpan_netlink_init(void)202 static inline int __init lowpan_netlink_init(void)
203 {
204 return rtnl_link_register(&lowpan_link_ops);
205 }
206
lowpan_netlink_fini(void)207 static inline void lowpan_netlink_fini(void)
208 {
209 rtnl_link_unregister(&lowpan_link_ops);
210 }
211
lowpan_device_event(struct notifier_block * unused,unsigned long event,void * ptr)212 static int lowpan_device_event(struct notifier_block *unused,
213 unsigned long event, void *ptr)
214 {
215 struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
216 struct wpan_dev *wpan_dev;
217
218 if (ndev->type != ARPHRD_IEEE802154)
219 return NOTIFY_DONE;
220 wpan_dev = ndev->ieee802154_ptr;
221 if (!wpan_dev)
222 return NOTIFY_DONE;
223
224 switch (event) {
225 case NETDEV_UNREGISTER:
226 /* Check if wpan interface is unregistered that we
227 * also delete possible lowpan interfaces which belongs
228 * to the wpan interface.
229 */
230 if (wpan_dev->lowpan_dev)
231 lowpan_dellink(wpan_dev->lowpan_dev, NULL);
232 break;
233 default:
234 return NOTIFY_DONE;
235 }
236
237 return NOTIFY_OK;
238 }
239
240 static struct notifier_block lowpan_dev_notifier = {
241 .notifier_call = lowpan_device_event,
242 };
243
lowpan_init_module(void)244 static int __init lowpan_init_module(void)
245 {
246 int err = 0;
247
248 err = lowpan_net_frag_init();
249 if (err < 0)
250 goto out;
251
252 err = lowpan_netlink_init();
253 if (err < 0)
254 goto out_frag;
255
256 err = register_netdevice_notifier(&lowpan_dev_notifier);
257 if (err < 0)
258 goto out_pack;
259
260 return 0;
261
262 out_pack:
263 lowpan_netlink_fini();
264 out_frag:
265 lowpan_net_frag_exit();
266 out:
267 return err;
268 }
269
lowpan_cleanup_module(void)270 static void __exit lowpan_cleanup_module(void)
271 {
272 lowpan_netlink_fini();
273
274 lowpan_net_frag_exit();
275
276 unregister_netdevice_notifier(&lowpan_dev_notifier);
277 }
278
279 module_init(lowpan_init_module);
280 module_exit(lowpan_cleanup_module);
281 MODULE_LICENSE("GPL");
282 MODULE_ALIAS_RTNL_LINK("lowpan");
283