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

source code of linux/net/ieee802154/6lowpan/core.c