xref: /linux/net/wireless/core.c (revision 492c826b9facefa84995f4dea917e301b5ee0884)
1 /*
2  * This is the linux wireless configuration interface.
3  *
4  * Copyright 2006-2010		Johannes Berg <johannes@sipsolutions.net>
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/if.h>
10 #include <linux/module.h>
11 #include <linux/err.h>
12 #include <linux/list.h>
13 #include <linux/slab.h>
14 #include <linux/nl80211.h>
15 #include <linux/debugfs.h>
16 #include <linux/notifier.h>
17 #include <linux/device.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <linux/sched.h>
21 #include <net/genetlink.h>
22 #include <net/cfg80211.h>
23 #include "nl80211.h"
24 #include "core.h"
25 #include "sysfs.h"
26 #include "debugfs.h"
27 #include "wext-compat.h"
28 #include "ethtool.h"
29 
30 /* name for sysfs, %d is appended */
31 #define PHY_NAME "phy"
32 
33 MODULE_AUTHOR("Johannes Berg");
34 MODULE_LICENSE("GPL");
35 MODULE_DESCRIPTION("wireless configuration support");
36 
37 /* RCU-protected (and cfg80211_mutex for writers) */
38 LIST_HEAD(cfg80211_rdev_list);
39 int cfg80211_rdev_list_generation;
40 
41 DEFINE_MUTEX(cfg80211_mutex);
42 
43 /* for debugfs */
44 static struct dentry *ieee80211_debugfs_dir;
45 
46 /* for the cleanup, scan and event works */
47 struct workqueue_struct *cfg80211_wq;
48 
49 static bool cfg80211_disable_40mhz_24ghz;
50 module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
51 MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
52 		 "Disable 40MHz support in the 2.4GHz band");
53 
54 /* requires cfg80211_mutex to be held! */
55 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
56 {
57 	struct cfg80211_registered_device *result = NULL, *rdev;
58 
59 	if (!wiphy_idx_valid(wiphy_idx))
60 		return NULL;
61 
62 	assert_cfg80211_lock();
63 
64 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
65 		if (rdev->wiphy_idx == wiphy_idx) {
66 			result = rdev;
67 			break;
68 		}
69 	}
70 
71 	return result;
72 }
73 
74 int get_wiphy_idx(struct wiphy *wiphy)
75 {
76 	struct cfg80211_registered_device *rdev;
77 	if (!wiphy)
78 		return WIPHY_IDX_STALE;
79 	rdev = wiphy_to_dev(wiphy);
80 	return rdev->wiphy_idx;
81 }
82 
83 /* requires cfg80211_rdev_mutex to be held! */
84 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
85 {
86 	struct cfg80211_registered_device *rdev;
87 
88 	if (!wiphy_idx_valid(wiphy_idx))
89 		return NULL;
90 
91 	assert_cfg80211_lock();
92 
93 	rdev = cfg80211_rdev_by_wiphy_idx(wiphy_idx);
94 	if (!rdev)
95 		return NULL;
96 	return &rdev->wiphy;
97 }
98 
99 /* requires cfg80211_mutex to be held! */
100 struct cfg80211_registered_device *
101 __cfg80211_rdev_from_info(struct genl_info *info)
102 {
103 	int ifindex;
104 	struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
105 	struct net_device *dev;
106 	int err = -EINVAL;
107 
108 	assert_cfg80211_lock();
109 
110 	if (info->attrs[NL80211_ATTR_WIPHY]) {
111 		bywiphyidx = cfg80211_rdev_by_wiphy_idx(
112 				nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
113 		err = -ENODEV;
114 	}
115 
116 	if (info->attrs[NL80211_ATTR_IFINDEX]) {
117 		ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
118 		dev = dev_get_by_index(genl_info_net(info), ifindex);
119 		if (dev) {
120 			if (dev->ieee80211_ptr)
121 				byifidx =
122 					wiphy_to_dev(dev->ieee80211_ptr->wiphy);
123 			dev_put(dev);
124 		}
125 		err = -ENODEV;
126 	}
127 
128 	if (bywiphyidx && byifidx) {
129 		if (bywiphyidx != byifidx)
130 			return ERR_PTR(-EINVAL);
131 		else
132 			return bywiphyidx; /* == byifidx */
133 	}
134 	if (bywiphyidx)
135 		return bywiphyidx;
136 
137 	if (byifidx)
138 		return byifidx;
139 
140 	return ERR_PTR(err);
141 }
142 
143 struct cfg80211_registered_device *
144 cfg80211_get_dev_from_info(struct genl_info *info)
145 {
146 	struct cfg80211_registered_device *rdev;
147 
148 	mutex_lock(&cfg80211_mutex);
149 	rdev = __cfg80211_rdev_from_info(info);
150 
151 	/* if it is not an error we grab the lock on
152 	 * it to assure it won't be going away while
153 	 * we operate on it */
154 	if (!IS_ERR(rdev))
155 		mutex_lock(&rdev->mtx);
156 
157 	mutex_unlock(&cfg80211_mutex);
158 
159 	return rdev;
160 }
161 
162 struct cfg80211_registered_device *
163 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
164 {
165 	struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV);
166 	struct net_device *dev;
167 
168 	mutex_lock(&cfg80211_mutex);
169 	dev = dev_get_by_index(net, ifindex);
170 	if (!dev)
171 		goto out;
172 	if (dev->ieee80211_ptr) {
173 		rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
174 		mutex_lock(&rdev->mtx);
175 	} else
176 		rdev = ERR_PTR(-ENODEV);
177 	dev_put(dev);
178  out:
179 	mutex_unlock(&cfg80211_mutex);
180 	return rdev;
181 }
182 
183 /* requires cfg80211_mutex to be held */
184 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
185 			char *newname)
186 {
187 	struct cfg80211_registered_device *rdev2;
188 	int wiphy_idx, taken = -1, result, digits;
189 
190 	assert_cfg80211_lock();
191 
192 	/* prohibit calling the thing phy%d when %d is not its number */
193 	sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
194 	if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
195 		/* count number of places needed to print wiphy_idx */
196 		digits = 1;
197 		while (wiphy_idx /= 10)
198 			digits++;
199 		/*
200 		 * deny the name if it is phy<idx> where <idx> is printed
201 		 * without leading zeroes. taken == strlen(newname) here
202 		 */
203 		if (taken == strlen(PHY_NAME) + digits)
204 			return -EINVAL;
205 	}
206 
207 
208 	/* Ignore nop renames */
209 	if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
210 		return 0;
211 
212 	/* Ensure another device does not already have this name. */
213 	list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
214 		if (strcmp(newname, dev_name(&rdev2->wiphy.dev)) == 0)
215 			return -EINVAL;
216 
217 	result = device_rename(&rdev->wiphy.dev, newname);
218 	if (result)
219 		return result;
220 
221 	if (rdev->wiphy.debugfsdir &&
222 	    !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
223 			    rdev->wiphy.debugfsdir,
224 			    rdev->wiphy.debugfsdir->d_parent,
225 			    newname))
226 		pr_err("failed to rename debugfs dir to %s!\n", newname);
227 
228 	nl80211_notify_dev_rename(rdev);
229 
230 	return 0;
231 }
232 
233 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
234 			  struct net *net)
235 {
236 	struct wireless_dev *wdev;
237 	int err = 0;
238 
239 	if (!(rdev->wiphy.flags & WIPHY_FLAG_NETNS_OK))
240 		return -EOPNOTSUPP;
241 
242 	list_for_each_entry(wdev, &rdev->netdev_list, list) {
243 		wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
244 		err = dev_change_net_namespace(wdev->netdev, net, "wlan%d");
245 		if (err)
246 			break;
247 		wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
248 	}
249 
250 	if (err) {
251 		/* failed -- clean up to old netns */
252 		net = wiphy_net(&rdev->wiphy);
253 
254 		list_for_each_entry_continue_reverse(wdev, &rdev->netdev_list,
255 						     list) {
256 			wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
257 			err = dev_change_net_namespace(wdev->netdev, net,
258 							"wlan%d");
259 			WARN_ON(err);
260 			wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
261 		}
262 
263 		return err;
264 	}
265 
266 	wiphy_net_set(&rdev->wiphy, net);
267 
268 	err = device_rename(&rdev->wiphy.dev, dev_name(&rdev->wiphy.dev));
269 	WARN_ON(err);
270 
271 	return 0;
272 }
273 
274 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
275 {
276 	struct cfg80211_registered_device *rdev = data;
277 
278 	rdev->ops->rfkill_poll(&rdev->wiphy);
279 }
280 
281 static int cfg80211_rfkill_set_block(void *data, bool blocked)
282 {
283 	struct cfg80211_registered_device *rdev = data;
284 	struct wireless_dev *wdev;
285 
286 	if (!blocked)
287 		return 0;
288 
289 	rtnl_lock();
290 	mutex_lock(&rdev->devlist_mtx);
291 
292 	list_for_each_entry(wdev, &rdev->netdev_list, list)
293 		dev_close(wdev->netdev);
294 
295 	mutex_unlock(&rdev->devlist_mtx);
296 	rtnl_unlock();
297 
298 	return 0;
299 }
300 
301 static void cfg80211_rfkill_sync_work(struct work_struct *work)
302 {
303 	struct cfg80211_registered_device *rdev;
304 
305 	rdev = container_of(work, struct cfg80211_registered_device, rfkill_sync);
306 	cfg80211_rfkill_set_block(rdev, rfkill_blocked(rdev->rfkill));
307 }
308 
309 static void cfg80211_event_work(struct work_struct *work)
310 {
311 	struct cfg80211_registered_device *rdev;
312 
313 	rdev = container_of(work, struct cfg80211_registered_device,
314 			    event_work);
315 
316 	rtnl_lock();
317 	cfg80211_lock_rdev(rdev);
318 
319 	cfg80211_process_rdev_events(rdev);
320 	cfg80211_unlock_rdev(rdev);
321 	rtnl_unlock();
322 }
323 
324 /* exported functions */
325 
326 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
327 {
328 	static int wiphy_counter;
329 
330 	struct cfg80211_registered_device *rdev;
331 	int alloc_size;
332 
333 	WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
334 	WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
335 	WARN_ON(ops->connect && !ops->disconnect);
336 	WARN_ON(ops->join_ibss && !ops->leave_ibss);
337 	WARN_ON(ops->add_virtual_intf && !ops->del_virtual_intf);
338 	WARN_ON(ops->add_station && !ops->del_station);
339 	WARN_ON(ops->add_mpath && !ops->del_mpath);
340 	WARN_ON(ops->join_mesh && !ops->leave_mesh);
341 
342 	alloc_size = sizeof(*rdev) + sizeof_priv;
343 
344 	rdev = kzalloc(alloc_size, GFP_KERNEL);
345 	if (!rdev)
346 		return NULL;
347 
348 	rdev->ops = ops;
349 
350 	mutex_lock(&cfg80211_mutex);
351 
352 	rdev->wiphy_idx = wiphy_counter++;
353 
354 	if (unlikely(!wiphy_idx_valid(rdev->wiphy_idx))) {
355 		wiphy_counter--;
356 		mutex_unlock(&cfg80211_mutex);
357 		/* ugh, wrapped! */
358 		kfree(rdev);
359 		return NULL;
360 	}
361 
362 	mutex_unlock(&cfg80211_mutex);
363 
364 	/* give it a proper name */
365 	dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
366 
367 	mutex_init(&rdev->mtx);
368 	mutex_init(&rdev->devlist_mtx);
369 	INIT_LIST_HEAD(&rdev->netdev_list);
370 	spin_lock_init(&rdev->bss_lock);
371 	INIT_LIST_HEAD(&rdev->bss_list);
372 	INIT_WORK(&rdev->scan_done_wk, __cfg80211_scan_done);
373 	INIT_WORK(&rdev->sched_scan_results_wk, __cfg80211_sched_scan_results);
374 #ifdef CONFIG_CFG80211_WEXT
375 	rdev->wiphy.wext = &cfg80211_wext_handler;
376 #endif
377 
378 	device_initialize(&rdev->wiphy.dev);
379 	rdev->wiphy.dev.class = &ieee80211_class;
380 	rdev->wiphy.dev.platform_data = rdev;
381 
382 #ifdef CONFIG_CFG80211_DEFAULT_PS
383 	rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
384 #endif
385 
386 	wiphy_net_set(&rdev->wiphy, &init_net);
387 
388 	rdev->rfkill_ops.set_block = cfg80211_rfkill_set_block;
389 	rdev->rfkill = rfkill_alloc(dev_name(&rdev->wiphy.dev),
390 				   &rdev->wiphy.dev, RFKILL_TYPE_WLAN,
391 				   &rdev->rfkill_ops, rdev);
392 
393 	if (!rdev->rfkill) {
394 		kfree(rdev);
395 		return NULL;
396 	}
397 
398 	INIT_WORK(&rdev->rfkill_sync, cfg80211_rfkill_sync_work);
399 	INIT_WORK(&rdev->conn_work, cfg80211_conn_work);
400 	INIT_WORK(&rdev->event_work, cfg80211_event_work);
401 
402 	init_waitqueue_head(&rdev->dev_wait);
403 
404 	/*
405 	 * Initialize wiphy parameters to IEEE 802.11 MIB default values.
406 	 * Fragmentation and RTS threshold are disabled by default with the
407 	 * special -1 value.
408 	 */
409 	rdev->wiphy.retry_short = 7;
410 	rdev->wiphy.retry_long = 4;
411 	rdev->wiphy.frag_threshold = (u32) -1;
412 	rdev->wiphy.rts_threshold = (u32) -1;
413 	rdev->wiphy.coverage_class = 0;
414 
415 	return &rdev->wiphy;
416 }
417 EXPORT_SYMBOL(wiphy_new);
418 
419 static int wiphy_verify_combinations(struct wiphy *wiphy)
420 {
421 	const struct ieee80211_iface_combination *c;
422 	int i, j;
423 
424 	/* If we have combinations enforce them */
425 	if (wiphy->n_iface_combinations)
426 		wiphy->flags |= WIPHY_FLAG_ENFORCE_COMBINATIONS;
427 
428 	for (i = 0; i < wiphy->n_iface_combinations; i++) {
429 		u32 cnt = 0;
430 		u16 all_iftypes = 0;
431 
432 		c = &wiphy->iface_combinations[i];
433 
434 		/* Combinations with just one interface aren't real */
435 		if (WARN_ON(c->max_interfaces < 2))
436 			return -EINVAL;
437 
438 		/* Need at least one channel */
439 		if (WARN_ON(!c->num_different_channels))
440 			return -EINVAL;
441 
442 		if (WARN_ON(!c->n_limits))
443 			return -EINVAL;
444 
445 		for (j = 0; j < c->n_limits; j++) {
446 			u16 types = c->limits[j].types;
447 
448 			/*
449 			 * interface types shouldn't overlap, this is
450 			 * used in cfg80211_can_change_interface()
451 			 */
452 			if (WARN_ON(types & all_iftypes))
453 				return -EINVAL;
454 			all_iftypes |= types;
455 
456 			if (WARN_ON(!c->limits[j].max))
457 				return -EINVAL;
458 
459 			/* Shouldn't list software iftypes in combinations! */
460 			if (WARN_ON(wiphy->software_iftypes & types))
461 				return -EINVAL;
462 
463 			cnt += c->limits[j].max;
464 			/*
465 			 * Don't advertise an unsupported type
466 			 * in a combination.
467 			 */
468 			if (WARN_ON((wiphy->interface_modes & types) != types))
469 				return -EINVAL;
470 		}
471 
472 		/* You can't even choose that many! */
473 		if (WARN_ON(cnt < c->max_interfaces))
474 			return -EINVAL;
475 	}
476 
477 	return 0;
478 }
479 
480 int wiphy_register(struct wiphy *wiphy)
481 {
482 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
483 	int res;
484 	enum ieee80211_band band;
485 	struct ieee80211_supported_band *sband;
486 	bool have_band = false;
487 	int i;
488 	u16 ifmodes = wiphy->interface_modes;
489 
490 	if (WARN_ON(wiphy->addresses && !wiphy->n_addresses))
491 		return -EINVAL;
492 
493 	if (WARN_ON(wiphy->addresses &&
494 		    !is_zero_ether_addr(wiphy->perm_addr) &&
495 		    memcmp(wiphy->perm_addr, wiphy->addresses[0].addr,
496 			   ETH_ALEN)))
497 		return -EINVAL;
498 
499 	if (wiphy->addresses)
500 		memcpy(wiphy->perm_addr, wiphy->addresses[0].addr, ETH_ALEN);
501 
502 	/* sanity check ifmodes */
503 	WARN_ON(!ifmodes);
504 	ifmodes &= ((1 << NUM_NL80211_IFTYPES) - 1) & ~1;
505 	if (WARN_ON(ifmodes != wiphy->interface_modes))
506 		wiphy->interface_modes = ifmodes;
507 
508 	res = wiphy_verify_combinations(wiphy);
509 	if (res)
510 		return res;
511 
512 	/* sanity check supported bands/channels */
513 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
514 		sband = wiphy->bands[band];
515 		if (!sband)
516 			continue;
517 
518 		sband->band = band;
519 
520 		if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
521 			return -EINVAL;
522 
523 		/*
524 		 * Since cfg80211_disable_40mhz_24ghz is global, we can
525 		 * modify the sband's ht data even if the driver uses a
526 		 * global structure for that.
527 		 */
528 		if (cfg80211_disable_40mhz_24ghz &&
529 		    band == IEEE80211_BAND_2GHZ &&
530 		    sband->ht_cap.ht_supported) {
531 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
532 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
533 		}
534 
535 		/*
536 		 * Since we use a u32 for rate bitmaps in
537 		 * ieee80211_get_response_rate, we cannot
538 		 * have more than 32 legacy rates.
539 		 */
540 		if (WARN_ON(sband->n_bitrates > 32))
541 			return -EINVAL;
542 
543 		for (i = 0; i < sband->n_channels; i++) {
544 			sband->channels[i].orig_flags =
545 				sband->channels[i].flags;
546 			sband->channels[i].orig_mag =
547 				sband->channels[i].max_antenna_gain;
548 			sband->channels[i].orig_mpwr =
549 				sband->channels[i].max_power;
550 			sband->channels[i].band = band;
551 		}
552 
553 		have_band = true;
554 	}
555 
556 	if (!have_band) {
557 		WARN_ON(1);
558 		return -EINVAL;
559 	}
560 
561 	if (rdev->wiphy.wowlan.n_patterns) {
562 		if (WARN_ON(!rdev->wiphy.wowlan.pattern_min_len ||
563 			    rdev->wiphy.wowlan.pattern_min_len >
564 			    rdev->wiphy.wowlan.pattern_max_len))
565 			return -EINVAL;
566 	}
567 
568 	/* check and set up bitrates */
569 	ieee80211_set_bitrate_flags(wiphy);
570 
571 	mutex_lock(&cfg80211_mutex);
572 
573 	res = device_add(&rdev->wiphy.dev);
574 	if (res) {
575 		mutex_unlock(&cfg80211_mutex);
576 		return res;
577 	}
578 
579 	/* set up regulatory info */
580 	wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
581 
582 	list_add_rcu(&rdev->list, &cfg80211_rdev_list);
583 	cfg80211_rdev_list_generation++;
584 
585 	/* add to debugfs */
586 	rdev->wiphy.debugfsdir =
587 		debugfs_create_dir(wiphy_name(&rdev->wiphy),
588 				   ieee80211_debugfs_dir);
589 	if (IS_ERR(rdev->wiphy.debugfsdir))
590 		rdev->wiphy.debugfsdir = NULL;
591 
592 	if (wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY) {
593 		struct regulatory_request request;
594 
595 		request.wiphy_idx = get_wiphy_idx(wiphy);
596 		request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
597 		request.alpha2[0] = '9';
598 		request.alpha2[1] = '9';
599 
600 		nl80211_send_reg_change_event(&request);
601 	}
602 
603 	cfg80211_debugfs_rdev_add(rdev);
604 	mutex_unlock(&cfg80211_mutex);
605 
606 	/*
607 	 * due to a locking dependency this has to be outside of the
608 	 * cfg80211_mutex lock
609 	 */
610 	res = rfkill_register(rdev->rfkill);
611 	if (res)
612 		goto out_rm_dev;
613 
614 	return 0;
615 
616 out_rm_dev:
617 	device_del(&rdev->wiphy.dev);
618 	return res;
619 }
620 EXPORT_SYMBOL(wiphy_register);
621 
622 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
623 {
624 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
625 
626 	if (!rdev->ops->rfkill_poll)
627 		return;
628 	rdev->rfkill_ops.poll = cfg80211_rfkill_poll;
629 	rfkill_resume_polling(rdev->rfkill);
630 }
631 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
632 
633 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
634 {
635 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
636 
637 	rfkill_pause_polling(rdev->rfkill);
638 }
639 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
640 
641 void wiphy_unregister(struct wiphy *wiphy)
642 {
643 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
644 
645 	rfkill_unregister(rdev->rfkill);
646 
647 	/* protect the device list */
648 	mutex_lock(&cfg80211_mutex);
649 
650 	wait_event(rdev->dev_wait, ({
651 		int __count;
652 		mutex_lock(&rdev->devlist_mtx);
653 		__count = rdev->opencount;
654 		mutex_unlock(&rdev->devlist_mtx);
655 		__count == 0;}));
656 
657 	mutex_lock(&rdev->devlist_mtx);
658 	BUG_ON(!list_empty(&rdev->netdev_list));
659 	mutex_unlock(&rdev->devlist_mtx);
660 
661 	/*
662 	 * First remove the hardware from everywhere, this makes
663 	 * it impossible to find from userspace.
664 	 */
665 	debugfs_remove_recursive(rdev->wiphy.debugfsdir);
666 	list_del_rcu(&rdev->list);
667 	synchronize_rcu();
668 
669 	/*
670 	 * Try to grab rdev->mtx. If a command is still in progress,
671 	 * hopefully the driver will refuse it since it's tearing
672 	 * down the device already. We wait for this command to complete
673 	 * before unlinking the item from the list.
674 	 * Note: as codified by the BUG_ON above we cannot get here if
675 	 * a virtual interface is still present. Hence, we can only get
676 	 * to lock contention here if userspace issues a command that
677 	 * identified the hardware by wiphy index.
678 	 */
679 	cfg80211_lock_rdev(rdev);
680 	/* nothing */
681 	cfg80211_unlock_rdev(rdev);
682 
683 	/* If this device got a regulatory hint tell core its
684 	 * free to listen now to a new shiny device regulatory hint */
685 	reg_device_remove(wiphy);
686 
687 	cfg80211_rdev_list_generation++;
688 	device_del(&rdev->wiphy.dev);
689 
690 	mutex_unlock(&cfg80211_mutex);
691 
692 	flush_work(&rdev->scan_done_wk);
693 	cancel_work_sync(&rdev->conn_work);
694 	flush_work(&rdev->event_work);
695 }
696 EXPORT_SYMBOL(wiphy_unregister);
697 
698 void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
699 {
700 	struct cfg80211_internal_bss *scan, *tmp;
701 	rfkill_destroy(rdev->rfkill);
702 	mutex_destroy(&rdev->mtx);
703 	mutex_destroy(&rdev->devlist_mtx);
704 	list_for_each_entry_safe(scan, tmp, &rdev->bss_list, list)
705 		cfg80211_put_bss(&scan->pub);
706 	cfg80211_rdev_free_wowlan(rdev);
707 	kfree(rdev);
708 }
709 
710 void wiphy_free(struct wiphy *wiphy)
711 {
712 	put_device(&wiphy->dev);
713 }
714 EXPORT_SYMBOL(wiphy_free);
715 
716 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
717 {
718 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
719 
720 	if (rfkill_set_hw_state(rdev->rfkill, blocked))
721 		schedule_work(&rdev->rfkill_sync);
722 }
723 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
724 
725 static void wdev_cleanup_work(struct work_struct *work)
726 {
727 	struct wireless_dev *wdev;
728 	struct cfg80211_registered_device *rdev;
729 
730 	wdev = container_of(work, struct wireless_dev, cleanup_work);
731 	rdev = wiphy_to_dev(wdev->wiphy);
732 
733 	cfg80211_lock_rdev(rdev);
734 
735 	if (WARN_ON(rdev->scan_req && rdev->scan_req->dev == wdev->netdev)) {
736 		rdev->scan_req->aborted = true;
737 		___cfg80211_scan_done(rdev, true);
738 	}
739 
740 	if (WARN_ON(rdev->sched_scan_req &&
741 		    rdev->sched_scan_req->dev == wdev->netdev)) {
742 		__cfg80211_stop_sched_scan(rdev, false);
743 	}
744 
745 	cfg80211_unlock_rdev(rdev);
746 
747 	mutex_lock(&rdev->devlist_mtx);
748 	rdev->opencount--;
749 	mutex_unlock(&rdev->devlist_mtx);
750 	wake_up(&rdev->dev_wait);
751 
752 	dev_put(wdev->netdev);
753 }
754 
755 static struct device_type wiphy_type = {
756 	.name	= "wlan",
757 };
758 
759 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
760 					 unsigned long state,
761 					 void *ndev)
762 {
763 	struct net_device *dev = ndev;
764 	struct wireless_dev *wdev = dev->ieee80211_ptr;
765 	struct cfg80211_registered_device *rdev;
766 	int ret;
767 
768 	if (!wdev)
769 		return NOTIFY_DONE;
770 
771 	rdev = wiphy_to_dev(wdev->wiphy);
772 
773 	WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
774 
775 	switch (state) {
776 	case NETDEV_POST_INIT:
777 		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
778 		break;
779 	case NETDEV_REGISTER:
780 		/*
781 		 * NB: cannot take rdev->mtx here because this may be
782 		 * called within code protected by it when interfaces
783 		 * are added with nl80211.
784 		 */
785 		mutex_init(&wdev->mtx);
786 		INIT_WORK(&wdev->cleanup_work, wdev_cleanup_work);
787 		INIT_LIST_HEAD(&wdev->event_list);
788 		spin_lock_init(&wdev->event_lock);
789 		INIT_LIST_HEAD(&wdev->mgmt_registrations);
790 		spin_lock_init(&wdev->mgmt_registrations_lock);
791 
792 		mutex_lock(&rdev->devlist_mtx);
793 		list_add_rcu(&wdev->list, &rdev->netdev_list);
794 		rdev->devlist_generation++;
795 		/* can only change netns with wiphy */
796 		dev->features |= NETIF_F_NETNS_LOCAL;
797 
798 		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
799 				      "phy80211")) {
800 			pr_err("failed to add phy80211 symlink to netdev!\n");
801 		}
802 		wdev->netdev = dev;
803 		wdev->sme_state = CFG80211_SME_IDLE;
804 		mutex_unlock(&rdev->devlist_mtx);
805 #ifdef CONFIG_CFG80211_WEXT
806 		wdev->wext.default_key = -1;
807 		wdev->wext.default_mgmt_key = -1;
808 		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
809 #endif
810 
811 		if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
812 			wdev->ps = true;
813 		else
814 			wdev->ps = false;
815 		/* allow mac80211 to determine the timeout */
816 		wdev->ps_timeout = -1;
817 
818 		if (!dev->ethtool_ops)
819 			dev->ethtool_ops = &cfg80211_ethtool_ops;
820 
821 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
822 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
823 		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
824 			dev->priv_flags |= IFF_DONT_BRIDGE;
825 		break;
826 	case NETDEV_GOING_DOWN:
827 		switch (wdev->iftype) {
828 		case NL80211_IFTYPE_ADHOC:
829 			cfg80211_leave_ibss(rdev, dev, true);
830 			break;
831 		case NL80211_IFTYPE_P2P_CLIENT:
832 		case NL80211_IFTYPE_STATION:
833 			cfg80211_lock_rdev(rdev);
834 			__cfg80211_stop_sched_scan(rdev, false);
835 			cfg80211_unlock_rdev(rdev);
836 
837 			wdev_lock(wdev);
838 #ifdef CONFIG_CFG80211_WEXT
839 			kfree(wdev->wext.ie);
840 			wdev->wext.ie = NULL;
841 			wdev->wext.ie_len = 0;
842 			wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
843 #endif
844 			__cfg80211_disconnect(rdev, dev,
845 					      WLAN_REASON_DEAUTH_LEAVING, true);
846 			cfg80211_mlme_down(rdev, dev);
847 			wdev_unlock(wdev);
848 			break;
849 		case NL80211_IFTYPE_MESH_POINT:
850 			cfg80211_leave_mesh(rdev, dev);
851 			break;
852 		default:
853 			break;
854 		}
855 		wdev->beacon_interval = 0;
856 		break;
857 	case NETDEV_DOWN:
858 		dev_hold(dev);
859 		queue_work(cfg80211_wq, &wdev->cleanup_work);
860 		break;
861 	case NETDEV_UP:
862 		/*
863 		 * If we have a really quick DOWN/UP succession we may
864 		 * have this work still pending ... cancel it and see
865 		 * if it was pending, in which case we need to account
866 		 * for some of the work it would have done.
867 		 */
868 		if (cancel_work_sync(&wdev->cleanup_work)) {
869 			mutex_lock(&rdev->devlist_mtx);
870 			rdev->opencount--;
871 			mutex_unlock(&rdev->devlist_mtx);
872 			dev_put(dev);
873 		}
874 		cfg80211_lock_rdev(rdev);
875 		mutex_lock(&rdev->devlist_mtx);
876 		wdev_lock(wdev);
877 		switch (wdev->iftype) {
878 #ifdef CONFIG_CFG80211_WEXT
879 		case NL80211_IFTYPE_ADHOC:
880 			cfg80211_ibss_wext_join(rdev, wdev);
881 			break;
882 		case NL80211_IFTYPE_STATION:
883 			cfg80211_mgd_wext_connect(rdev, wdev);
884 			break;
885 #endif
886 #ifdef CONFIG_MAC80211_MESH
887 		case NL80211_IFTYPE_MESH_POINT:
888 			{
889 				/* backward compat code... */
890 				struct mesh_setup setup;
891 				memcpy(&setup, &default_mesh_setup,
892 						sizeof(setup));
893 				 /* back compat only needed for mesh_id */
894 				setup.mesh_id = wdev->ssid;
895 				setup.mesh_id_len = wdev->mesh_id_up_len;
896 				if (wdev->mesh_id_up_len)
897 					__cfg80211_join_mesh(rdev, dev,
898 							&setup,
899 							&default_mesh_config);
900 				break;
901 			}
902 #endif
903 		default:
904 			break;
905 		}
906 		wdev_unlock(wdev);
907 		rdev->opencount++;
908 		mutex_unlock(&rdev->devlist_mtx);
909 		cfg80211_unlock_rdev(rdev);
910 
911 		/*
912 		 * Configure power management to the driver here so that its
913 		 * correctly set also after interface type changes etc.
914 		 */
915 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
916 		    rdev->ops->set_power_mgmt)
917 			if (rdev->ops->set_power_mgmt(wdev->wiphy, dev,
918 						      wdev->ps,
919 						      wdev->ps_timeout)) {
920 				/* assume this means it's off */
921 				wdev->ps = false;
922 			}
923 		break;
924 	case NETDEV_UNREGISTER:
925 		/*
926 		 * NB: cannot take rdev->mtx here because this may be
927 		 * called within code protected by it when interfaces
928 		 * are removed with nl80211.
929 		 */
930 		mutex_lock(&rdev->devlist_mtx);
931 		/*
932 		 * It is possible to get NETDEV_UNREGISTER
933 		 * multiple times. To detect that, check
934 		 * that the interface is still on the list
935 		 * of registered interfaces, and only then
936 		 * remove and clean it up.
937 		 */
938 		if (!list_empty(&wdev->list)) {
939 			sysfs_remove_link(&dev->dev.kobj, "phy80211");
940 			list_del_rcu(&wdev->list);
941 			rdev->devlist_generation++;
942 			cfg80211_mlme_purge_registrations(wdev);
943 #ifdef CONFIG_CFG80211_WEXT
944 			kfree(wdev->wext.keys);
945 #endif
946 		}
947 		mutex_unlock(&rdev->devlist_mtx);
948 		/*
949 		 * synchronise (so that we won't find this netdev
950 		 * from other code any more) and then clear the list
951 		 * head so that the above code can safely check for
952 		 * !list_empty() to avoid double-cleanup.
953 		 */
954 		synchronize_rcu();
955 		INIT_LIST_HEAD(&wdev->list);
956 		break;
957 	case NETDEV_PRE_UP:
958 		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
959 			return notifier_from_errno(-EOPNOTSUPP);
960 		if (rfkill_blocked(rdev->rfkill))
961 			return notifier_from_errno(-ERFKILL);
962 		ret = cfg80211_can_add_interface(rdev, wdev->iftype);
963 		if (ret)
964 			return notifier_from_errno(ret);
965 		break;
966 	}
967 
968 	return NOTIFY_DONE;
969 }
970 
971 static struct notifier_block cfg80211_netdev_notifier = {
972 	.notifier_call = cfg80211_netdev_notifier_call,
973 };
974 
975 static void __net_exit cfg80211_pernet_exit(struct net *net)
976 {
977 	struct cfg80211_registered_device *rdev;
978 
979 	rtnl_lock();
980 	mutex_lock(&cfg80211_mutex);
981 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
982 		if (net_eq(wiphy_net(&rdev->wiphy), net))
983 			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
984 	}
985 	mutex_unlock(&cfg80211_mutex);
986 	rtnl_unlock();
987 }
988 
989 static struct pernet_operations cfg80211_pernet_ops = {
990 	.exit = cfg80211_pernet_exit,
991 };
992 
993 static int __init cfg80211_init(void)
994 {
995 	int err;
996 
997 	err = register_pernet_device(&cfg80211_pernet_ops);
998 	if (err)
999 		goto out_fail_pernet;
1000 
1001 	err = wiphy_sysfs_init();
1002 	if (err)
1003 		goto out_fail_sysfs;
1004 
1005 	err = register_netdevice_notifier(&cfg80211_netdev_notifier);
1006 	if (err)
1007 		goto out_fail_notifier;
1008 
1009 	err = nl80211_init();
1010 	if (err)
1011 		goto out_fail_nl80211;
1012 
1013 	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
1014 
1015 	err = regulatory_init();
1016 	if (err)
1017 		goto out_fail_reg;
1018 
1019 	cfg80211_wq = create_singlethread_workqueue("cfg80211");
1020 	if (!cfg80211_wq)
1021 		goto out_fail_wq;
1022 
1023 	return 0;
1024 
1025 out_fail_wq:
1026 	regulatory_exit();
1027 out_fail_reg:
1028 	debugfs_remove(ieee80211_debugfs_dir);
1029 out_fail_nl80211:
1030 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1031 out_fail_notifier:
1032 	wiphy_sysfs_exit();
1033 out_fail_sysfs:
1034 	unregister_pernet_device(&cfg80211_pernet_ops);
1035 out_fail_pernet:
1036 	return err;
1037 }
1038 subsys_initcall(cfg80211_init);
1039 
1040 static void __exit cfg80211_exit(void)
1041 {
1042 	debugfs_remove(ieee80211_debugfs_dir);
1043 	nl80211_exit();
1044 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1045 	wiphy_sysfs_exit();
1046 	regulatory_exit();
1047 	unregister_pernet_device(&cfg80211_pernet_ops);
1048 	destroy_workqueue(cfg80211_wq);
1049 }
1050 module_exit(cfg80211_exit);
1051