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