xref: /openbmc/linux/net/ieee802154/core.c (revision 5d331b7f)
1 /*
2  * Copyright (C) 2007, 2008, 2009 Siemens AG
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2
6  * as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 
20 #include <net/cfg802154.h>
21 #include <net/rtnetlink.h>
22 
23 #include "ieee802154.h"
24 #include "nl802154.h"
25 #include "sysfs.h"
26 #include "core.h"
27 
28 /* name for sysfs, %d is appended */
29 #define PHY_NAME "phy"
30 
31 /* RCU-protected (and RTNL for writers) */
32 LIST_HEAD(cfg802154_rdev_list);
33 int cfg802154_rdev_list_generation;
34 
35 static int wpan_phy_match(struct device *dev, const void *data)
36 {
37 	return !strcmp(dev_name(dev), (const char *)data);
38 }
39 
40 struct wpan_phy *wpan_phy_find(const char *str)
41 {
42 	struct device *dev;
43 
44 	if (WARN_ON(!str))
45 		return NULL;
46 
47 	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
48 	if (!dev)
49 		return NULL;
50 
51 	return container_of(dev, struct wpan_phy, dev);
52 }
53 EXPORT_SYMBOL(wpan_phy_find);
54 
55 struct wpan_phy_iter_data {
56 	int (*fn)(struct wpan_phy *phy, void *data);
57 	void *data;
58 };
59 
60 static int wpan_phy_iter(struct device *dev, void *_data)
61 {
62 	struct wpan_phy_iter_data *wpid = _data;
63 	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
64 
65 	return wpid->fn(phy, wpid->data);
66 }
67 
68 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
69 		      void *data)
70 {
71 	struct wpan_phy_iter_data wpid = {
72 		.fn = fn,
73 		.data = data,
74 	};
75 
76 	return class_for_each_device(&wpan_phy_class, NULL,
77 			&wpid, wpan_phy_iter);
78 }
79 EXPORT_SYMBOL(wpan_phy_for_each);
80 
81 struct cfg802154_registered_device *
82 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
83 {
84 	struct cfg802154_registered_device *result = NULL, *rdev;
85 
86 	ASSERT_RTNL();
87 
88 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
89 		if (rdev->wpan_phy_idx == wpan_phy_idx) {
90 			result = rdev;
91 			break;
92 		}
93 	}
94 
95 	return result;
96 }
97 
98 struct wpan_phy *wpan_phy_idx_to_wpan_phy(int wpan_phy_idx)
99 {
100 	struct cfg802154_registered_device *rdev;
101 
102 	ASSERT_RTNL();
103 
104 	rdev = cfg802154_rdev_by_wpan_phy_idx(wpan_phy_idx);
105 	if (!rdev)
106 		return NULL;
107 	return &rdev->wpan_phy;
108 }
109 
110 struct wpan_phy *
111 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
112 {
113 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
114 	struct cfg802154_registered_device *rdev;
115 	size_t alloc_size;
116 
117 	alloc_size = sizeof(*rdev) + priv_size;
118 	rdev = kzalloc(alloc_size, GFP_KERNEL);
119 	if (!rdev)
120 		return NULL;
121 
122 	rdev->ops = ops;
123 
124 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
125 
126 	if (unlikely(rdev->wpan_phy_idx < 0)) {
127 		/* ugh, wrapped! */
128 		atomic_dec(&wpan_phy_counter);
129 		kfree(rdev);
130 		return NULL;
131 	}
132 
133 	/* atomic_inc_return makes it start at 1, make it start at 0 */
134 	rdev->wpan_phy_idx--;
135 
136 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
137 	device_initialize(&rdev->wpan_phy.dev);
138 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
139 
140 	rdev->wpan_phy.dev.class = &wpan_phy_class;
141 	rdev->wpan_phy.dev.platform_data = rdev;
142 
143 	wpan_phy_net_set(&rdev->wpan_phy, &init_net);
144 
145 	init_waitqueue_head(&rdev->dev_wait);
146 
147 	return &rdev->wpan_phy;
148 }
149 EXPORT_SYMBOL(wpan_phy_new);
150 
151 int wpan_phy_register(struct wpan_phy *phy)
152 {
153 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
154 	int ret;
155 
156 	rtnl_lock();
157 	ret = device_add(&phy->dev);
158 	if (ret) {
159 		rtnl_unlock();
160 		return ret;
161 	}
162 
163 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
164 	cfg802154_rdev_list_generation++;
165 
166 	/* TODO phy registered lock */
167 	rtnl_unlock();
168 
169 	/* TODO nl802154 phy notify */
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL(wpan_phy_register);
174 
175 void wpan_phy_unregister(struct wpan_phy *phy)
176 {
177 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
178 
179 	wait_event(rdev->dev_wait, ({
180 		int __count;
181 		rtnl_lock();
182 		__count = rdev->opencount;
183 		rtnl_unlock();
184 		__count == 0; }));
185 
186 	rtnl_lock();
187 	/* TODO nl802154 phy notify */
188 	/* TODO phy registered lock */
189 
190 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
191 
192 	/* First remove the hardware from everywhere, this makes
193 	 * it impossible to find from userspace.
194 	 */
195 	list_del_rcu(&rdev->list);
196 	synchronize_rcu();
197 
198 	cfg802154_rdev_list_generation++;
199 
200 	device_del(&phy->dev);
201 
202 	rtnl_unlock();
203 }
204 EXPORT_SYMBOL(wpan_phy_unregister);
205 
206 void wpan_phy_free(struct wpan_phy *phy)
207 {
208 	put_device(&phy->dev);
209 }
210 EXPORT_SYMBOL(wpan_phy_free);
211 
212 int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
213 			   struct net *net)
214 {
215 	struct wpan_dev *wpan_dev;
216 	int err = 0;
217 
218 	list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
219 		if (!wpan_dev->netdev)
220 			continue;
221 		wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
222 		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
223 		if (err)
224 			break;
225 		wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
226 	}
227 
228 	if (err) {
229 		/* failed -- clean up to old netns */
230 		net = wpan_phy_net(&rdev->wpan_phy);
231 
232 		list_for_each_entry_continue_reverse(wpan_dev,
233 						     &rdev->wpan_dev_list,
234 						     list) {
235 			if (!wpan_dev->netdev)
236 				continue;
237 			wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
238 			err = dev_change_net_namespace(wpan_dev->netdev, net,
239 						       "wpan%d");
240 			WARN_ON(err);
241 			wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
242 		}
243 
244 		return err;
245 	}
246 
247 	wpan_phy_net_set(&rdev->wpan_phy, net);
248 
249 	err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
250 	WARN_ON(err);
251 
252 	return 0;
253 }
254 
255 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
256 {
257 	kfree(rdev);
258 }
259 
260 static void
261 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
262 			   int iftype, int num)
263 {
264 	ASSERT_RTNL();
265 
266 	rdev->num_running_ifaces += num;
267 }
268 
269 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
270 					  unsigned long state, void *ptr)
271 {
272 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
273 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
274 	struct cfg802154_registered_device *rdev;
275 
276 	if (!wpan_dev)
277 		return NOTIFY_DONE;
278 
279 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
280 
281 	/* TODO WARN_ON unspec type */
282 
283 	switch (state) {
284 		/* TODO NETDEV_DEVTYPE */
285 	case NETDEV_REGISTER:
286 		dev->features |= NETIF_F_NETNS_LOCAL;
287 		wpan_dev->identifier = ++rdev->wpan_dev_id;
288 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
289 		rdev->devlist_generation++;
290 
291 		wpan_dev->netdev = dev;
292 		break;
293 	case NETDEV_DOWN:
294 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
295 
296 		rdev->opencount--;
297 		wake_up(&rdev->dev_wait);
298 		break;
299 	case NETDEV_UP:
300 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
301 
302 		rdev->opencount++;
303 		break;
304 	case NETDEV_UNREGISTER:
305 		/* It is possible to get NETDEV_UNREGISTER
306 		 * multiple times. To detect that, check
307 		 * that the interface is still on the list
308 		 * of registered interfaces, and only then
309 		 * remove and clean it up.
310 		 */
311 		if (!list_empty(&wpan_dev->list)) {
312 			list_del_rcu(&wpan_dev->list);
313 			rdev->devlist_generation++;
314 		}
315 		/* synchronize (so that we won't find this netdev
316 		 * from other code any more) and then clear the list
317 		 * head so that the above code can safely check for
318 		 * !list_empty() to avoid double-cleanup.
319 		 */
320 		synchronize_rcu();
321 		INIT_LIST_HEAD(&wpan_dev->list);
322 		break;
323 	default:
324 		return NOTIFY_DONE;
325 	}
326 
327 	return NOTIFY_OK;
328 }
329 
330 static struct notifier_block cfg802154_netdev_notifier = {
331 	.notifier_call = cfg802154_netdev_notifier_call,
332 };
333 
334 static void __net_exit cfg802154_pernet_exit(struct net *net)
335 {
336 	struct cfg802154_registered_device *rdev;
337 
338 	rtnl_lock();
339 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
340 		if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
341 			WARN_ON(cfg802154_switch_netns(rdev, &init_net));
342 	}
343 	rtnl_unlock();
344 }
345 
346 static struct pernet_operations cfg802154_pernet_ops = {
347 	.exit = cfg802154_pernet_exit,
348 };
349 
350 static int __init wpan_phy_class_init(void)
351 {
352 	int rc;
353 
354 	rc = register_pernet_device(&cfg802154_pernet_ops);
355 	if (rc)
356 		goto err;
357 
358 	rc = wpan_phy_sysfs_init();
359 	if (rc)
360 		goto err_sysfs;
361 
362 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
363 	if (rc)
364 		goto err_nl;
365 
366 	rc = ieee802154_nl_init();
367 	if (rc)
368 		goto err_notifier;
369 
370 	rc = nl802154_init();
371 	if (rc)
372 		goto err_ieee802154_nl;
373 
374 	return 0;
375 
376 err_ieee802154_nl:
377 	ieee802154_nl_exit();
378 
379 err_notifier:
380 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
381 err_nl:
382 	wpan_phy_sysfs_exit();
383 err_sysfs:
384 	unregister_pernet_device(&cfg802154_pernet_ops);
385 err:
386 	return rc;
387 }
388 subsys_initcall(wpan_phy_class_init);
389 
390 static void __exit wpan_phy_class_exit(void)
391 {
392 	nl802154_exit();
393 	ieee802154_nl_exit();
394 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
395 	wpan_phy_sysfs_exit();
396 	unregister_pernet_device(&cfg802154_pernet_ops);
397 }
398 module_exit(wpan_phy_class_exit);
399 
400 MODULE_LICENSE("GPL v2");
401 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
402 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
403