xref: /linux/net/ieee802154/core.c (revision 056a5087d87ead77dedbe9cf5bde53b7cd4b4651)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007, 2008, 2009 Siemens AG
4  */
5 
6 #include <linux/slab.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/device.h>
10 
11 #include <net/cfg802154.h>
12 #include <net/rtnetlink.h>
13 
14 #include "ieee802154.h"
15 #include "nl802154.h"
16 #include "sysfs.h"
17 #include "core.h"
18 
19 /* name for sysfs, %d is appended */
20 #define PHY_NAME "phy"
21 
22 /* RCU-protected (and RTNL for writers) */
23 LIST_HEAD(cfg802154_rdev_list);
24 int cfg802154_rdev_list_generation;
25 
26 struct wpan_phy *wpan_phy_find(const char *str)
27 {
28 	struct device *dev;
29 
30 	if (WARN_ON(!str))
31 		return NULL;
32 
33 	dev = class_find_device_by_name(&wpan_phy_class, str);
34 	if (!dev)
35 		return NULL;
36 
37 	return container_of(dev, struct wpan_phy, dev);
38 }
39 EXPORT_SYMBOL(wpan_phy_find);
40 
41 struct wpan_phy_iter_data {
42 	int (*fn)(struct wpan_phy *phy, void *data);
43 	void *data;
44 };
45 
46 static int wpan_phy_iter(struct device *dev, void *_data)
47 {
48 	struct wpan_phy_iter_data *wpid = _data;
49 	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
50 
51 	return wpid->fn(phy, wpid->data);
52 }
53 
54 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
55 		      void *data)
56 {
57 	struct wpan_phy_iter_data wpid = {
58 		.fn = fn,
59 		.data = data,
60 	};
61 
62 	return class_for_each_device(&wpan_phy_class, NULL,
63 			&wpid, wpan_phy_iter);
64 }
65 EXPORT_SYMBOL(wpan_phy_for_each);
66 
67 struct cfg802154_registered_device *
68 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
69 {
70 	struct cfg802154_registered_device *result = NULL, *rdev;
71 
72 	ASSERT_RTNL();
73 
74 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
75 		if (rdev->wpan_phy_idx == wpan_phy_idx) {
76 			result = rdev;
77 			break;
78 		}
79 	}
80 
81 	return result;
82 }
83 
84 struct wpan_phy *wpan_phy_idx_to_wpan_phy(int wpan_phy_idx)
85 {
86 	struct cfg802154_registered_device *rdev;
87 
88 	ASSERT_RTNL();
89 
90 	rdev = cfg802154_rdev_by_wpan_phy_idx(wpan_phy_idx);
91 	if (!rdev)
92 		return NULL;
93 	return &rdev->wpan_phy;
94 }
95 
96 struct wpan_phy *
97 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
98 {
99 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
100 	struct cfg802154_registered_device *rdev;
101 	size_t alloc_size;
102 
103 	alloc_size = sizeof(*rdev) + priv_size;
104 	rdev = kzalloc(alloc_size, GFP_KERNEL);
105 	if (!rdev)
106 		return NULL;
107 
108 	rdev->ops = ops;
109 
110 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
111 
112 	if (unlikely(rdev->wpan_phy_idx < 0)) {
113 		/* ugh, wrapped! */
114 		atomic_dec(&wpan_phy_counter);
115 		kfree(rdev);
116 		return NULL;
117 	}
118 
119 	/* atomic_inc_return makes it start at 1, make it start at 0 */
120 	rdev->wpan_phy_idx--;
121 
122 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
123 	device_initialize(&rdev->wpan_phy.dev);
124 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
125 
126 	rdev->wpan_phy.dev.class = &wpan_phy_class;
127 	rdev->wpan_phy.dev.platform_data = rdev;
128 
129 	wpan_phy_net_set(&rdev->wpan_phy, &init_net);
130 
131 	init_waitqueue_head(&rdev->dev_wait);
132 	init_waitqueue_head(&rdev->wpan_phy.sync_txq);
133 
134 	spin_lock_init(&rdev->wpan_phy.queue_lock);
135 
136 	return &rdev->wpan_phy;
137 }
138 EXPORT_SYMBOL(wpan_phy_new);
139 
140 int wpan_phy_register(struct wpan_phy *phy)
141 {
142 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
143 	int ret;
144 
145 	rtnl_lock();
146 	ret = device_add(&phy->dev);
147 	if (ret) {
148 		rtnl_unlock();
149 		return ret;
150 	}
151 
152 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
153 	cfg802154_rdev_list_generation++;
154 
155 	/* TODO phy registered lock */
156 	rtnl_unlock();
157 
158 	/* TODO nl802154 phy notify */
159 
160 	return 0;
161 }
162 EXPORT_SYMBOL(wpan_phy_register);
163 
164 void wpan_phy_unregister(struct wpan_phy *phy)
165 {
166 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
167 
168 	wait_event(rdev->dev_wait, ({
169 		int __count;
170 		rtnl_lock();
171 		__count = rdev->opencount;
172 		rtnl_unlock();
173 		__count == 0; }));
174 
175 	rtnl_lock();
176 	/* TODO nl802154 phy notify */
177 	/* TODO phy registered lock */
178 
179 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
180 
181 	/* First remove the hardware from everywhere, this makes
182 	 * it impossible to find from userspace.
183 	 */
184 	list_del_rcu(&rdev->list);
185 	synchronize_rcu();
186 
187 	cfg802154_rdev_list_generation++;
188 
189 	device_del(&phy->dev);
190 
191 	rtnl_unlock();
192 }
193 EXPORT_SYMBOL(wpan_phy_unregister);
194 
195 void wpan_phy_free(struct wpan_phy *phy)
196 {
197 	put_device(&phy->dev);
198 }
199 EXPORT_SYMBOL(wpan_phy_free);
200 
201 static void cfg802154_free_peer_structures(struct wpan_dev *wpan_dev)
202 {
203 	struct ieee802154_pan_device *child, *tmp;
204 
205 	mutex_lock(&wpan_dev->association_lock);
206 
207 	kfree(wpan_dev->parent);
208 	wpan_dev->parent = NULL;
209 
210 	list_for_each_entry_safe(child, tmp, &wpan_dev->children, node) {
211 		list_del(&child->node);
212 		kfree(child);
213 	}
214 
215 	wpan_dev->nchildren = 0;
216 
217 	mutex_unlock(&wpan_dev->association_lock);
218 }
219 
220 int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
221 			   struct net *net)
222 {
223 	struct wpan_dev *wpan_dev;
224 	int err = 0;
225 
226 	list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
227 		if (!wpan_dev->netdev)
228 			continue;
229 		wpan_dev->netdev->netns_immutable = false;
230 		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
231 		if (err) {
232 			WARN_ON(err && err != -ENOMEM);
233 			break;
234 		}
235 		wpan_dev->netdev->netns_immutable = true;
236 	}
237 
238 	if (err)
239 		goto errout;
240 
241 	err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
242 	WARN_ON(err && err != -ENOMEM);
243 
244 	if (err)
245 		goto errout;
246 
247 	wpan_phy_net_set(&rdev->wpan_phy, net);
248 
249 	return 0;
250 
251 errout:
252 	/* failed -- clean up to old netns */
253 	net = wpan_phy_net(&rdev->wpan_phy);
254 
255 	list_for_each_entry_continue_reverse(wpan_dev,
256 					     &rdev->wpan_dev_list,
257 					     list) {
258 		if (!wpan_dev->netdev)
259 			continue;
260 		wpan_dev->netdev->netns_immutable = false;
261 		err = dev_change_net_namespace(wpan_dev->netdev, net,
262 					       "wpan%d");
263 		WARN_ON(err && err != -ENOMEM);
264 		wpan_dev->netdev->netns_immutable = true;
265 	}
266 
267 	return err;
268 }
269 
270 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
271 {
272 	kfree(rdev);
273 }
274 
275 static void
276 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
277 			   int iftype, int num)
278 {
279 	ASSERT_RTNL();
280 
281 	rdev->num_running_ifaces += num;
282 }
283 
284 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
285 					  unsigned long state, void *ptr)
286 {
287 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
288 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
289 	struct cfg802154_registered_device *rdev;
290 
291 	if (!wpan_dev)
292 		return NOTIFY_DONE;
293 
294 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
295 
296 	/* TODO WARN_ON unspec type */
297 
298 	switch (state) {
299 		/* TODO NETDEV_DEVTYPE */
300 	case NETDEV_REGISTER:
301 		dev->netns_immutable = true;
302 		wpan_dev->identifier = ++rdev->wpan_dev_id;
303 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
304 		rdev->devlist_generation++;
305 		mutex_init(&wpan_dev->association_lock);
306 		INIT_LIST_HEAD(&wpan_dev->children);
307 		wpan_dev->max_associations = SZ_16K;
308 
309 		wpan_dev->netdev = dev;
310 		break;
311 	case NETDEV_DOWN:
312 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
313 
314 		rdev->opencount--;
315 		wake_up(&rdev->dev_wait);
316 		break;
317 	case NETDEV_UP:
318 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
319 
320 		rdev->opencount++;
321 		break;
322 	case NETDEV_UNREGISTER:
323 		cfg802154_free_peer_structures(wpan_dev);
324 
325 		/* It is possible to get NETDEV_UNREGISTER
326 		 * multiple times. To detect that, check
327 		 * that the interface is still on the list
328 		 * of registered interfaces, and only then
329 		 * remove and clean it up.
330 		 */
331 		if (!list_empty(&wpan_dev->list)) {
332 			list_del_rcu(&wpan_dev->list);
333 			rdev->devlist_generation++;
334 		}
335 		/* synchronize (so that we won't find this netdev
336 		 * from other code any more) and then clear the list
337 		 * head so that the above code can safely check for
338 		 * !list_empty() to avoid double-cleanup.
339 		 */
340 		synchronize_rcu();
341 		INIT_LIST_HEAD(&wpan_dev->list);
342 		break;
343 	default:
344 		return NOTIFY_DONE;
345 	}
346 
347 	return NOTIFY_OK;
348 }
349 
350 static struct notifier_block cfg802154_netdev_notifier = {
351 	.notifier_call = cfg802154_netdev_notifier_call,
352 };
353 
354 static void __net_exit cfg802154_pernet_exit(struct net *net)
355 {
356 	struct cfg802154_registered_device *rdev;
357 
358 	rtnl_lock();
359 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
360 		if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
361 			cfg802154_switch_netns(rdev, &init_net);
362 	}
363 	rtnl_unlock();
364 }
365 
366 static struct pernet_operations cfg802154_pernet_ops = {
367 	.exit = cfg802154_pernet_exit,
368 };
369 
370 static int __init wpan_phy_class_init(void)
371 {
372 	int rc;
373 
374 	rc = register_pernet_device(&cfg802154_pernet_ops);
375 	if (rc)
376 		goto err;
377 
378 	rc = wpan_phy_sysfs_init();
379 	if (rc)
380 		goto err_sysfs;
381 
382 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
383 	if (rc)
384 		goto err_nl;
385 
386 	rc = ieee802154_nl_init();
387 	if (rc)
388 		goto err_notifier;
389 
390 	rc = nl802154_init();
391 	if (rc)
392 		goto err_ieee802154_nl;
393 
394 	return 0;
395 
396 err_ieee802154_nl:
397 	ieee802154_nl_exit();
398 
399 err_notifier:
400 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
401 err_nl:
402 	wpan_phy_sysfs_exit();
403 err_sysfs:
404 	unregister_pernet_device(&cfg802154_pernet_ops);
405 err:
406 	return rc;
407 }
408 subsys_initcall(wpan_phy_class_init);
409 
410 static void __exit wpan_phy_class_exit(void)
411 {
412 	nl802154_exit();
413 	ieee802154_nl_exit();
414 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
415 	wpan_phy_sysfs_exit();
416 	unregister_pernet_device(&cfg802154_pernet_ops);
417 }
418 module_exit(wpan_phy_class_exit);
419 
420 MODULE_LICENSE("GPL v2");
421 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
422 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
423