xref: /linux/net/wireless/core.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * This is the linux wireless configuration interface.
3  *
4  * Copyright 2006-2010		Johannes Berg <johannes@sipsolutions.net>
5  * Copyright 2013-2014  Intel Mobile Communications GmbH
6  * Copyright 2015	Intel Deutschland GmbH
7  */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/if.h>
12 #include <linux/module.h>
13 #include <linux/err.h>
14 #include <linux/list.h>
15 #include <linux/slab.h>
16 #include <linux/nl80211.h>
17 #include <linux/debugfs.h>
18 #include <linux/notifier.h>
19 #include <linux/device.h>
20 #include <linux/etherdevice.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/sched.h>
23 #include <net/genetlink.h>
24 #include <net/cfg80211.h>
25 #include "nl80211.h"
26 #include "core.h"
27 #include "sysfs.h"
28 #include "debugfs.h"
29 #include "wext-compat.h"
30 #include "rdev-ops.h"
31 
32 /* name for sysfs, %d is appended */
33 #define PHY_NAME "phy"
34 
35 MODULE_AUTHOR("Johannes Berg");
36 MODULE_LICENSE("GPL");
37 MODULE_DESCRIPTION("wireless configuration support");
38 MODULE_ALIAS_GENL_FAMILY(NL80211_GENL_NAME);
39 
40 /* RCU-protected (and RTNL for writers) */
41 LIST_HEAD(cfg80211_rdev_list);
42 int cfg80211_rdev_list_generation;
43 
44 /* for debugfs */
45 static struct dentry *ieee80211_debugfs_dir;
46 
47 /* for the cleanup, scan and event works */
48 struct workqueue_struct *cfg80211_wq;
49 
50 static bool cfg80211_disable_40mhz_24ghz;
51 module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
52 MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
53 		 "Disable 40MHz support in the 2.4GHz band");
54 
55 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
56 {
57 	struct cfg80211_registered_device *result = NULL, *rdev;
58 
59 	ASSERT_RTNL();
60 
61 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
62 		if (rdev->wiphy_idx == wiphy_idx) {
63 			result = rdev;
64 			break;
65 		}
66 	}
67 
68 	return result;
69 }
70 
71 int get_wiphy_idx(struct wiphy *wiphy)
72 {
73 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
74 
75 	return rdev->wiphy_idx;
76 }
77 
78 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
79 {
80 	struct cfg80211_registered_device *rdev;
81 
82 	ASSERT_RTNL();
83 
84 	rdev = cfg80211_rdev_by_wiphy_idx(wiphy_idx);
85 	if (!rdev)
86 		return NULL;
87 	return &rdev->wiphy;
88 }
89 
90 static int cfg80211_dev_check_name(struct cfg80211_registered_device *rdev,
91 				   const char *newname)
92 {
93 	struct cfg80211_registered_device *rdev2;
94 	int wiphy_idx, taken = -1, digits;
95 
96 	ASSERT_RTNL();
97 
98 	/* prohibit calling the thing phy%d when %d is not its number */
99 	sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
100 	if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
101 		/* count number of places needed to print wiphy_idx */
102 		digits = 1;
103 		while (wiphy_idx /= 10)
104 			digits++;
105 		/*
106 		 * deny the name if it is phy<idx> where <idx> is printed
107 		 * without leading zeroes. taken == strlen(newname) here
108 		 */
109 		if (taken == strlen(PHY_NAME) + digits)
110 			return -EINVAL;
111 	}
112 
113 	/* Ensure another device does not already have this name. */
114 	list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
115 		if (strcmp(newname, wiphy_name(&rdev2->wiphy)) == 0)
116 			return -EINVAL;
117 
118 	return 0;
119 }
120 
121 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
122 			char *newname)
123 {
124 	int result;
125 
126 	ASSERT_RTNL();
127 
128 	/* Ignore nop renames */
129 	if (strcmp(newname, wiphy_name(&rdev->wiphy)) == 0)
130 		return 0;
131 
132 	result = cfg80211_dev_check_name(rdev, newname);
133 	if (result < 0)
134 		return result;
135 
136 	result = device_rename(&rdev->wiphy.dev, newname);
137 	if (result)
138 		return result;
139 
140 	if (rdev->wiphy.debugfsdir &&
141 	    !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
142 			    rdev->wiphy.debugfsdir,
143 			    rdev->wiphy.debugfsdir->d_parent,
144 			    newname))
145 		pr_err("failed to rename debugfs dir to %s!\n", newname);
146 
147 	nl80211_notify_wiphy(rdev, NL80211_CMD_NEW_WIPHY);
148 
149 	return 0;
150 }
151 
152 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
153 			  struct net *net)
154 {
155 	struct wireless_dev *wdev;
156 	int err = 0;
157 
158 	if (!(rdev->wiphy.flags & WIPHY_FLAG_NETNS_OK))
159 		return -EOPNOTSUPP;
160 
161 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
162 		if (!wdev->netdev)
163 			continue;
164 		wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
165 		err = dev_change_net_namespace(wdev->netdev, net, "wlan%d");
166 		if (err)
167 			break;
168 		wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
169 	}
170 
171 	if (err) {
172 		/* failed -- clean up to old netns */
173 		net = wiphy_net(&rdev->wiphy);
174 
175 		list_for_each_entry_continue_reverse(wdev,
176 						     &rdev->wiphy.wdev_list,
177 						     list) {
178 			if (!wdev->netdev)
179 				continue;
180 			wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
181 			err = dev_change_net_namespace(wdev->netdev, net,
182 							"wlan%d");
183 			WARN_ON(err);
184 			wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
185 		}
186 
187 		return err;
188 	}
189 
190 	wiphy_net_set(&rdev->wiphy, net);
191 
192 	err = device_rename(&rdev->wiphy.dev, dev_name(&rdev->wiphy.dev));
193 	WARN_ON(err);
194 
195 	return 0;
196 }
197 
198 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
199 {
200 	struct cfg80211_registered_device *rdev = data;
201 
202 	rdev_rfkill_poll(rdev);
203 }
204 
205 void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev,
206 			      struct wireless_dev *wdev)
207 {
208 	ASSERT_RTNL();
209 
210 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_P2P_DEVICE))
211 		return;
212 
213 	if (!wdev_running(wdev))
214 		return;
215 
216 	rdev_stop_p2p_device(rdev, wdev);
217 	wdev->is_running = false;
218 
219 	rdev->opencount--;
220 
221 	if (rdev->scan_req && rdev->scan_req->wdev == wdev) {
222 		if (WARN_ON(!rdev->scan_req->notified))
223 			rdev->scan_req->info.aborted = true;
224 		___cfg80211_scan_done(rdev, false);
225 	}
226 }
227 
228 void cfg80211_stop_nan(struct cfg80211_registered_device *rdev,
229 		       struct wireless_dev *wdev)
230 {
231 	ASSERT_RTNL();
232 
233 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_NAN))
234 		return;
235 
236 	if (!wdev_running(wdev))
237 		return;
238 
239 	rdev_stop_nan(rdev, wdev);
240 	wdev->is_running = false;
241 
242 	rdev->opencount--;
243 }
244 
245 void cfg80211_shutdown_all_interfaces(struct wiphy *wiphy)
246 {
247 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
248 	struct wireless_dev *wdev;
249 
250 	ASSERT_RTNL();
251 
252 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
253 		if (wdev->netdev) {
254 			dev_close(wdev->netdev);
255 			continue;
256 		}
257 		/* otherwise, check iftype */
258 		switch (wdev->iftype) {
259 		case NL80211_IFTYPE_P2P_DEVICE:
260 			cfg80211_stop_p2p_device(rdev, wdev);
261 			break;
262 		case NL80211_IFTYPE_NAN:
263 			cfg80211_stop_nan(rdev, wdev);
264 			break;
265 		default:
266 			break;
267 		}
268 	}
269 }
270 EXPORT_SYMBOL_GPL(cfg80211_shutdown_all_interfaces);
271 
272 static int cfg80211_rfkill_set_block(void *data, bool blocked)
273 {
274 	struct cfg80211_registered_device *rdev = data;
275 
276 	if (!blocked)
277 		return 0;
278 
279 	rtnl_lock();
280 	cfg80211_shutdown_all_interfaces(&rdev->wiphy);
281 	rtnl_unlock();
282 
283 	return 0;
284 }
285 
286 static void cfg80211_rfkill_sync_work(struct work_struct *work)
287 {
288 	struct cfg80211_registered_device *rdev;
289 
290 	rdev = container_of(work, struct cfg80211_registered_device, rfkill_sync);
291 	cfg80211_rfkill_set_block(rdev, rfkill_blocked(rdev->rfkill));
292 }
293 
294 static void cfg80211_event_work(struct work_struct *work)
295 {
296 	struct cfg80211_registered_device *rdev;
297 
298 	rdev = container_of(work, struct cfg80211_registered_device,
299 			    event_work);
300 
301 	rtnl_lock();
302 	cfg80211_process_rdev_events(rdev);
303 	rtnl_unlock();
304 }
305 
306 void cfg80211_destroy_ifaces(struct cfg80211_registered_device *rdev)
307 {
308 	struct cfg80211_iface_destroy *item;
309 
310 	ASSERT_RTNL();
311 
312 	spin_lock_irq(&rdev->destroy_list_lock);
313 	while ((item = list_first_entry_or_null(&rdev->destroy_list,
314 						struct cfg80211_iface_destroy,
315 						list))) {
316 		struct wireless_dev *wdev, *tmp;
317 		u32 nlportid = item->nlportid;
318 
319 		list_del(&item->list);
320 		kfree(item);
321 		spin_unlock_irq(&rdev->destroy_list_lock);
322 
323 		list_for_each_entry_safe(wdev, tmp,
324 					 &rdev->wiphy.wdev_list, list) {
325 			if (nlportid == wdev->owner_nlportid)
326 				rdev_del_virtual_intf(rdev, wdev);
327 		}
328 
329 		spin_lock_irq(&rdev->destroy_list_lock);
330 	}
331 	spin_unlock_irq(&rdev->destroy_list_lock);
332 }
333 
334 static void cfg80211_destroy_iface_wk(struct work_struct *work)
335 {
336 	struct cfg80211_registered_device *rdev;
337 
338 	rdev = container_of(work, struct cfg80211_registered_device,
339 			    destroy_work);
340 
341 	rtnl_lock();
342 	cfg80211_destroy_ifaces(rdev);
343 	rtnl_unlock();
344 }
345 
346 static void cfg80211_sched_scan_stop_wk(struct work_struct *work)
347 {
348 	struct cfg80211_registered_device *rdev;
349 
350 	rdev = container_of(work, struct cfg80211_registered_device,
351 			   sched_scan_stop_wk);
352 
353 	rtnl_lock();
354 
355 	__cfg80211_stop_sched_scan(rdev, false);
356 
357 	rtnl_unlock();
358 }
359 
360 /* exported functions */
361 
362 struct wiphy *wiphy_new_nm(const struct cfg80211_ops *ops, int sizeof_priv,
363 			   const char *requested_name)
364 {
365 	static atomic_t wiphy_counter = ATOMIC_INIT(0);
366 
367 	struct cfg80211_registered_device *rdev;
368 	int alloc_size;
369 
370 	WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
371 	WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
372 	WARN_ON(ops->connect && !ops->disconnect);
373 	WARN_ON(ops->join_ibss && !ops->leave_ibss);
374 	WARN_ON(ops->add_virtual_intf && !ops->del_virtual_intf);
375 	WARN_ON(ops->add_station && !ops->del_station);
376 	WARN_ON(ops->add_mpath && !ops->del_mpath);
377 	WARN_ON(ops->join_mesh && !ops->leave_mesh);
378 	WARN_ON(ops->start_p2p_device && !ops->stop_p2p_device);
379 	WARN_ON(ops->start_ap && !ops->stop_ap);
380 	WARN_ON(ops->join_ocb && !ops->leave_ocb);
381 	WARN_ON(ops->suspend && !ops->resume);
382 	WARN_ON(ops->sched_scan_start && !ops->sched_scan_stop);
383 	WARN_ON(ops->remain_on_channel && !ops->cancel_remain_on_channel);
384 	WARN_ON(ops->tdls_channel_switch && !ops->tdls_cancel_channel_switch);
385 	WARN_ON(ops->add_tx_ts && !ops->del_tx_ts);
386 
387 	alloc_size = sizeof(*rdev) + sizeof_priv;
388 
389 	rdev = kzalloc(alloc_size, GFP_KERNEL);
390 	if (!rdev)
391 		return NULL;
392 
393 	rdev->ops = ops;
394 
395 	rdev->wiphy_idx = atomic_inc_return(&wiphy_counter);
396 
397 	if (unlikely(rdev->wiphy_idx < 0)) {
398 		/* ugh, wrapped! */
399 		atomic_dec(&wiphy_counter);
400 		kfree(rdev);
401 		return NULL;
402 	}
403 
404 	/* atomic_inc_return makes it start at 1, make it start at 0 */
405 	rdev->wiphy_idx--;
406 
407 	/* give it a proper name */
408 	if (requested_name && requested_name[0]) {
409 		int rv;
410 
411 		rtnl_lock();
412 		rv = cfg80211_dev_check_name(rdev, requested_name);
413 
414 		if (rv < 0) {
415 			rtnl_unlock();
416 			goto use_default_name;
417 		}
418 
419 		rv = dev_set_name(&rdev->wiphy.dev, "%s", requested_name);
420 		rtnl_unlock();
421 		if (rv)
422 			goto use_default_name;
423 	} else {
424 use_default_name:
425 		/* NOTE:  This is *probably* safe w/out holding rtnl because of
426 		 * the restrictions on phy names.  Probably this call could
427 		 * fail if some other part of the kernel (re)named a device
428 		 * phyX.  But, might should add some locking and check return
429 		 * value, and use a different name if this one exists?
430 		 */
431 		dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
432 	}
433 
434 	INIT_LIST_HEAD(&rdev->wiphy.wdev_list);
435 	INIT_LIST_HEAD(&rdev->beacon_registrations);
436 	spin_lock_init(&rdev->beacon_registrations_lock);
437 	spin_lock_init(&rdev->bss_lock);
438 	INIT_LIST_HEAD(&rdev->bss_list);
439 	INIT_WORK(&rdev->scan_done_wk, __cfg80211_scan_done);
440 	INIT_WORK(&rdev->sched_scan_results_wk, __cfg80211_sched_scan_results);
441 	INIT_LIST_HEAD(&rdev->mlme_unreg);
442 	spin_lock_init(&rdev->mlme_unreg_lock);
443 	INIT_WORK(&rdev->mlme_unreg_wk, cfg80211_mlme_unreg_wk);
444 	INIT_DELAYED_WORK(&rdev->dfs_update_channels_wk,
445 			  cfg80211_dfs_channels_update_work);
446 #ifdef CONFIG_CFG80211_WEXT
447 	rdev->wiphy.wext = &cfg80211_wext_handler;
448 #endif
449 
450 	device_initialize(&rdev->wiphy.dev);
451 	rdev->wiphy.dev.class = &ieee80211_class;
452 	rdev->wiphy.dev.platform_data = rdev;
453 	device_enable_async_suspend(&rdev->wiphy.dev);
454 
455 	INIT_LIST_HEAD(&rdev->destroy_list);
456 	spin_lock_init(&rdev->destroy_list_lock);
457 	INIT_WORK(&rdev->destroy_work, cfg80211_destroy_iface_wk);
458 	INIT_WORK(&rdev->sched_scan_stop_wk, cfg80211_sched_scan_stop_wk);
459 
460 #ifdef CONFIG_CFG80211_DEFAULT_PS
461 	rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
462 #endif
463 
464 	wiphy_net_set(&rdev->wiphy, &init_net);
465 
466 	rdev->rfkill_ops.set_block = cfg80211_rfkill_set_block;
467 	rdev->rfkill = rfkill_alloc(dev_name(&rdev->wiphy.dev),
468 				   &rdev->wiphy.dev, RFKILL_TYPE_WLAN,
469 				   &rdev->rfkill_ops, rdev);
470 
471 	if (!rdev->rfkill) {
472 		kfree(rdev);
473 		return NULL;
474 	}
475 
476 	INIT_WORK(&rdev->rfkill_sync, cfg80211_rfkill_sync_work);
477 	INIT_WORK(&rdev->conn_work, cfg80211_conn_work);
478 	INIT_WORK(&rdev->event_work, cfg80211_event_work);
479 
480 	init_waitqueue_head(&rdev->dev_wait);
481 
482 	/*
483 	 * Initialize wiphy parameters to IEEE 802.11 MIB default values.
484 	 * Fragmentation and RTS threshold are disabled by default with the
485 	 * special -1 value.
486 	 */
487 	rdev->wiphy.retry_short = 7;
488 	rdev->wiphy.retry_long = 4;
489 	rdev->wiphy.frag_threshold = (u32) -1;
490 	rdev->wiphy.rts_threshold = (u32) -1;
491 	rdev->wiphy.coverage_class = 0;
492 
493 	rdev->wiphy.max_num_csa_counters = 1;
494 
495 	rdev->wiphy.max_sched_scan_plans = 1;
496 	rdev->wiphy.max_sched_scan_plan_interval = U32_MAX;
497 
498 	return &rdev->wiphy;
499 }
500 EXPORT_SYMBOL(wiphy_new_nm);
501 
502 static int wiphy_verify_combinations(struct wiphy *wiphy)
503 {
504 	const struct ieee80211_iface_combination *c;
505 	int i, j;
506 
507 	for (i = 0; i < wiphy->n_iface_combinations; i++) {
508 		u32 cnt = 0;
509 		u16 all_iftypes = 0;
510 
511 		c = &wiphy->iface_combinations[i];
512 
513 		/*
514 		 * Combinations with just one interface aren't real,
515 		 * however we make an exception for DFS.
516 		 */
517 		if (WARN_ON((c->max_interfaces < 2) && !c->radar_detect_widths))
518 			return -EINVAL;
519 
520 		/* Need at least one channel */
521 		if (WARN_ON(!c->num_different_channels))
522 			return -EINVAL;
523 
524 		/*
525 		 * Put a sane limit on maximum number of different
526 		 * channels to simplify channel accounting code.
527 		 */
528 		if (WARN_ON(c->num_different_channels >
529 				CFG80211_MAX_NUM_DIFFERENT_CHANNELS))
530 			return -EINVAL;
531 
532 		/* DFS only works on one channel. */
533 		if (WARN_ON(c->radar_detect_widths &&
534 			    (c->num_different_channels > 1)))
535 			return -EINVAL;
536 
537 		if (WARN_ON(!c->n_limits))
538 			return -EINVAL;
539 
540 		for (j = 0; j < c->n_limits; j++) {
541 			u16 types = c->limits[j].types;
542 
543 			/* interface types shouldn't overlap */
544 			if (WARN_ON(types & all_iftypes))
545 				return -EINVAL;
546 			all_iftypes |= types;
547 
548 			if (WARN_ON(!c->limits[j].max))
549 				return -EINVAL;
550 
551 			/* Shouldn't list software iftypes in combinations! */
552 			if (WARN_ON(wiphy->software_iftypes & types))
553 				return -EINVAL;
554 
555 			/* Only a single P2P_DEVICE can be allowed */
556 			if (WARN_ON(types & BIT(NL80211_IFTYPE_P2P_DEVICE) &&
557 				    c->limits[j].max > 1))
558 				return -EINVAL;
559 
560 			/* Only a single NAN can be allowed */
561 			if (WARN_ON(types & BIT(NL80211_IFTYPE_NAN) &&
562 				    c->limits[j].max > 1))
563 				return -EINVAL;
564 
565 			/*
566 			 * This isn't well-defined right now. If you have an
567 			 * IBSS interface, then its beacon interval may change
568 			 * by joining other networks, and nothing prevents it
569 			 * from doing that.
570 			 * So technically we probably shouldn't even allow AP
571 			 * and IBSS in the same interface, but it seems that
572 			 * some drivers support that, possibly only with fixed
573 			 * beacon intervals for IBSS.
574 			 */
575 			if (WARN_ON(types & BIT(NL80211_IFTYPE_ADHOC) &&
576 				    c->beacon_int_min_gcd)) {
577 				return -EINVAL;
578 			}
579 
580 			cnt += c->limits[j].max;
581 			/*
582 			 * Don't advertise an unsupported type
583 			 * in a combination.
584 			 */
585 			if (WARN_ON((wiphy->interface_modes & types) != types))
586 				return -EINVAL;
587 		}
588 
589 #ifndef CONFIG_WIRELESS_WDS
590 		if (WARN_ON(all_iftypes & BIT(NL80211_IFTYPE_WDS)))
591 			return -EINVAL;
592 #endif
593 
594 		/* You can't even choose that many! */
595 		if (WARN_ON(cnt < c->max_interfaces))
596 			return -EINVAL;
597 	}
598 
599 	return 0;
600 }
601 
602 int wiphy_register(struct wiphy *wiphy)
603 {
604 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
605 	int res;
606 	enum nl80211_band band;
607 	struct ieee80211_supported_band *sband;
608 	bool have_band = false;
609 	int i;
610 	u16 ifmodes = wiphy->interface_modes;
611 
612 #ifdef CONFIG_PM
613 	if (WARN_ON(wiphy->wowlan &&
614 		    (wiphy->wowlan->flags & WIPHY_WOWLAN_GTK_REKEY_FAILURE) &&
615 		    !(wiphy->wowlan->flags & WIPHY_WOWLAN_SUPPORTS_GTK_REKEY)))
616 		return -EINVAL;
617 	if (WARN_ON(wiphy->wowlan &&
618 		    !wiphy->wowlan->flags && !wiphy->wowlan->n_patterns &&
619 		    !wiphy->wowlan->tcp))
620 		return -EINVAL;
621 #endif
622 	if (WARN_ON((wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) &&
623 		    (!rdev->ops->tdls_channel_switch ||
624 		     !rdev->ops->tdls_cancel_channel_switch)))
625 		return -EINVAL;
626 
627 	if (WARN_ON((wiphy->interface_modes & BIT(NL80211_IFTYPE_NAN)) &&
628 		    (!rdev->ops->start_nan || !rdev->ops->stop_nan ||
629 		     !rdev->ops->add_nan_func || !rdev->ops->del_nan_func ||
630 		     !(wiphy->nan_supported_bands & BIT(NL80211_BAND_2GHZ)))))
631 		return -EINVAL;
632 
633 #ifndef CONFIG_WIRELESS_WDS
634 	if (WARN_ON(wiphy->interface_modes & BIT(NL80211_IFTYPE_WDS)))
635 		return -EINVAL;
636 #endif
637 
638 	/*
639 	 * if a wiphy has unsupported modes for regulatory channel enforcement,
640 	 * opt-out of enforcement checking
641 	 */
642 	if (wiphy->interface_modes & ~(BIT(NL80211_IFTYPE_STATION) |
643 				       BIT(NL80211_IFTYPE_P2P_CLIENT) |
644 				       BIT(NL80211_IFTYPE_AP) |
645 				       BIT(NL80211_IFTYPE_P2P_GO) |
646 				       BIT(NL80211_IFTYPE_ADHOC) |
647 				       BIT(NL80211_IFTYPE_P2P_DEVICE) |
648 				       BIT(NL80211_IFTYPE_NAN) |
649 				       BIT(NL80211_IFTYPE_AP_VLAN) |
650 				       BIT(NL80211_IFTYPE_MONITOR)))
651 		wiphy->regulatory_flags |= REGULATORY_IGNORE_STALE_KICKOFF;
652 
653 	if (WARN_ON((wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED) &&
654 		    (wiphy->regulatory_flags &
655 					(REGULATORY_CUSTOM_REG |
656 					 REGULATORY_STRICT_REG |
657 					 REGULATORY_COUNTRY_IE_FOLLOW_POWER |
658 					 REGULATORY_COUNTRY_IE_IGNORE))))
659 		return -EINVAL;
660 
661 	if (WARN_ON(wiphy->coalesce &&
662 		    (!wiphy->coalesce->n_rules ||
663 		     !wiphy->coalesce->n_patterns) &&
664 		    (!wiphy->coalesce->pattern_min_len ||
665 		     wiphy->coalesce->pattern_min_len >
666 			wiphy->coalesce->pattern_max_len)))
667 		return -EINVAL;
668 
669 	if (WARN_ON(wiphy->ap_sme_capa &&
670 		    !(wiphy->flags & WIPHY_FLAG_HAVE_AP_SME)))
671 		return -EINVAL;
672 
673 	if (WARN_ON(wiphy->addresses && !wiphy->n_addresses))
674 		return -EINVAL;
675 
676 	if (WARN_ON(wiphy->addresses &&
677 		    !is_zero_ether_addr(wiphy->perm_addr) &&
678 		    memcmp(wiphy->perm_addr, wiphy->addresses[0].addr,
679 			   ETH_ALEN)))
680 		return -EINVAL;
681 
682 	if (WARN_ON(wiphy->max_acl_mac_addrs &&
683 		    (!(wiphy->flags & WIPHY_FLAG_HAVE_AP_SME) ||
684 		     !rdev->ops->set_mac_acl)))
685 		return -EINVAL;
686 
687 	/* assure only valid behaviours are flagged by driver
688 	 * hence subtract 2 as bit 0 is invalid.
689 	 */
690 	if (WARN_ON(wiphy->bss_select_support &&
691 		    (wiphy->bss_select_support & ~(BIT(__NL80211_BSS_SELECT_ATTR_AFTER_LAST) - 2))))
692 		return -EINVAL;
693 
694 	if (wiphy->addresses)
695 		memcpy(wiphy->perm_addr, wiphy->addresses[0].addr, ETH_ALEN);
696 
697 	/* sanity check ifmodes */
698 	WARN_ON(!ifmodes);
699 	ifmodes &= ((1 << NUM_NL80211_IFTYPES) - 1) & ~1;
700 	if (WARN_ON(ifmodes != wiphy->interface_modes))
701 		wiphy->interface_modes = ifmodes;
702 
703 	res = wiphy_verify_combinations(wiphy);
704 	if (res)
705 		return res;
706 
707 	/* sanity check supported bands/channels */
708 	for (band = 0; band < NUM_NL80211_BANDS; band++) {
709 		sband = wiphy->bands[band];
710 		if (!sband)
711 			continue;
712 
713 		sband->band = band;
714 		if (WARN_ON(!sband->n_channels))
715 			return -EINVAL;
716 		/*
717 		 * on 60GHz band, there are no legacy rates, so
718 		 * n_bitrates is 0
719 		 */
720 		if (WARN_ON(band != NL80211_BAND_60GHZ &&
721 			    !sband->n_bitrates))
722 			return -EINVAL;
723 
724 		/*
725 		 * Since cfg80211_disable_40mhz_24ghz is global, we can
726 		 * modify the sband's ht data even if the driver uses a
727 		 * global structure for that.
728 		 */
729 		if (cfg80211_disable_40mhz_24ghz &&
730 		    band == NL80211_BAND_2GHZ &&
731 		    sband->ht_cap.ht_supported) {
732 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
733 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
734 		}
735 
736 		/*
737 		 * Since we use a u32 for rate bitmaps in
738 		 * ieee80211_get_response_rate, we cannot
739 		 * have more than 32 legacy rates.
740 		 */
741 		if (WARN_ON(sband->n_bitrates > 32))
742 			return -EINVAL;
743 
744 		for (i = 0; i < sband->n_channels; i++) {
745 			sband->channels[i].orig_flags =
746 				sband->channels[i].flags;
747 			sband->channels[i].orig_mag = INT_MAX;
748 			sband->channels[i].orig_mpwr =
749 				sband->channels[i].max_power;
750 			sband->channels[i].band = band;
751 		}
752 
753 		have_band = true;
754 	}
755 
756 	if (!have_band) {
757 		WARN_ON(1);
758 		return -EINVAL;
759 	}
760 
761 #ifdef CONFIG_PM
762 	if (WARN_ON(rdev->wiphy.wowlan && rdev->wiphy.wowlan->n_patterns &&
763 		    (!rdev->wiphy.wowlan->pattern_min_len ||
764 		     rdev->wiphy.wowlan->pattern_min_len >
765 				rdev->wiphy.wowlan->pattern_max_len)))
766 		return -EINVAL;
767 #endif
768 
769 	/* check and set up bitrates */
770 	ieee80211_set_bitrate_flags(wiphy);
771 
772 	rdev->wiphy.features |= NL80211_FEATURE_SCAN_FLUSH;
773 
774 	rtnl_lock();
775 	res = device_add(&rdev->wiphy.dev);
776 	if (res) {
777 		rtnl_unlock();
778 		return res;
779 	}
780 
781 	/* set up regulatory info */
782 	wiphy_regulatory_register(wiphy);
783 
784 	list_add_rcu(&rdev->list, &cfg80211_rdev_list);
785 	cfg80211_rdev_list_generation++;
786 
787 	/* add to debugfs */
788 	rdev->wiphy.debugfsdir =
789 		debugfs_create_dir(wiphy_name(&rdev->wiphy),
790 				   ieee80211_debugfs_dir);
791 	if (IS_ERR(rdev->wiphy.debugfsdir))
792 		rdev->wiphy.debugfsdir = NULL;
793 
794 	cfg80211_debugfs_rdev_add(rdev);
795 	nl80211_notify_wiphy(rdev, NL80211_CMD_NEW_WIPHY);
796 
797 	if (wiphy->regulatory_flags & REGULATORY_CUSTOM_REG) {
798 		struct regulatory_request request;
799 
800 		request.wiphy_idx = get_wiphy_idx(wiphy);
801 		request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
802 		request.alpha2[0] = '9';
803 		request.alpha2[1] = '9';
804 
805 		nl80211_send_reg_change_event(&request);
806 	}
807 
808 	/* Check that nobody globally advertises any capabilities they do not
809 	 * advertise on all possible interface types.
810 	 */
811 	if (wiphy->extended_capabilities_len &&
812 	    wiphy->num_iftype_ext_capab &&
813 	    wiphy->iftype_ext_capab) {
814 		u8 supported_on_all, j;
815 		const struct wiphy_iftype_ext_capab *capab;
816 
817 		capab = wiphy->iftype_ext_capab;
818 		for (j = 0; j < wiphy->extended_capabilities_len; j++) {
819 			if (capab[0].extended_capabilities_len > j)
820 				supported_on_all =
821 					capab[0].extended_capabilities[j];
822 			else
823 				supported_on_all = 0x00;
824 			for (i = 1; i < wiphy->num_iftype_ext_capab; i++) {
825 				if (j >= capab[i].extended_capabilities_len) {
826 					supported_on_all = 0x00;
827 					break;
828 				}
829 				supported_on_all &=
830 					capab[i].extended_capabilities[j];
831 			}
832 			if (WARN_ON(wiphy->extended_capabilities[j] &
833 				    ~supported_on_all))
834 				break;
835 		}
836 	}
837 
838 	rdev->wiphy.registered = true;
839 	rtnl_unlock();
840 
841 	res = rfkill_register(rdev->rfkill);
842 	if (res) {
843 		rfkill_destroy(rdev->rfkill);
844 		rdev->rfkill = NULL;
845 		wiphy_unregister(&rdev->wiphy);
846 		return res;
847 	}
848 
849 	return 0;
850 }
851 EXPORT_SYMBOL(wiphy_register);
852 
853 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
854 {
855 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
856 
857 	if (!rdev->ops->rfkill_poll)
858 		return;
859 	rdev->rfkill_ops.poll = cfg80211_rfkill_poll;
860 	rfkill_resume_polling(rdev->rfkill);
861 }
862 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
863 
864 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
865 {
866 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
867 
868 	rfkill_pause_polling(rdev->rfkill);
869 }
870 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
871 
872 void wiphy_unregister(struct wiphy *wiphy)
873 {
874 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
875 
876 	wait_event(rdev->dev_wait, ({
877 		int __count;
878 		rtnl_lock();
879 		__count = rdev->opencount;
880 		rtnl_unlock();
881 		__count == 0; }));
882 
883 	if (rdev->rfkill)
884 		rfkill_unregister(rdev->rfkill);
885 
886 	rtnl_lock();
887 	nl80211_notify_wiphy(rdev, NL80211_CMD_DEL_WIPHY);
888 	rdev->wiphy.registered = false;
889 
890 	WARN_ON(!list_empty(&rdev->wiphy.wdev_list));
891 
892 	/*
893 	 * First remove the hardware from everywhere, this makes
894 	 * it impossible to find from userspace.
895 	 */
896 	debugfs_remove_recursive(rdev->wiphy.debugfsdir);
897 	list_del_rcu(&rdev->list);
898 	synchronize_rcu();
899 
900 	/*
901 	 * If this device got a regulatory hint tell core its
902 	 * free to listen now to a new shiny device regulatory hint
903 	 */
904 	wiphy_regulatory_deregister(wiphy);
905 
906 	cfg80211_rdev_list_generation++;
907 	device_del(&rdev->wiphy.dev);
908 
909 	rtnl_unlock();
910 
911 	flush_work(&rdev->scan_done_wk);
912 	cancel_work_sync(&rdev->conn_work);
913 	flush_work(&rdev->event_work);
914 	cancel_delayed_work_sync(&rdev->dfs_update_channels_wk);
915 	flush_work(&rdev->destroy_work);
916 	flush_work(&rdev->sched_scan_stop_wk);
917 	flush_work(&rdev->mlme_unreg_wk);
918 
919 #ifdef CONFIG_PM
920 	if (rdev->wiphy.wowlan_config && rdev->ops->set_wakeup)
921 		rdev_set_wakeup(rdev, false);
922 #endif
923 	cfg80211_rdev_free_wowlan(rdev);
924 	cfg80211_rdev_free_coalesce(rdev);
925 }
926 EXPORT_SYMBOL(wiphy_unregister);
927 
928 void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
929 {
930 	struct cfg80211_internal_bss *scan, *tmp;
931 	struct cfg80211_beacon_registration *reg, *treg;
932 	rfkill_destroy(rdev->rfkill);
933 	list_for_each_entry_safe(reg, treg, &rdev->beacon_registrations, list) {
934 		list_del(&reg->list);
935 		kfree(reg);
936 	}
937 	list_for_each_entry_safe(scan, tmp, &rdev->bss_list, list)
938 		cfg80211_put_bss(&rdev->wiphy, &scan->pub);
939 	kfree(rdev);
940 }
941 
942 void wiphy_free(struct wiphy *wiphy)
943 {
944 	put_device(&wiphy->dev);
945 }
946 EXPORT_SYMBOL(wiphy_free);
947 
948 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
949 {
950 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
951 
952 	if (rfkill_set_hw_state(rdev->rfkill, blocked))
953 		schedule_work(&rdev->rfkill_sync);
954 }
955 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
956 
957 void cfg80211_unregister_wdev(struct wireless_dev *wdev)
958 {
959 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
960 
961 	ASSERT_RTNL();
962 
963 	if (WARN_ON(wdev->netdev))
964 		return;
965 
966 	nl80211_notify_iface(rdev, wdev, NL80211_CMD_DEL_INTERFACE);
967 
968 	list_del_rcu(&wdev->list);
969 	rdev->devlist_generation++;
970 
971 	switch (wdev->iftype) {
972 	case NL80211_IFTYPE_P2P_DEVICE:
973 		cfg80211_mlme_purge_registrations(wdev);
974 		cfg80211_stop_p2p_device(rdev, wdev);
975 		break;
976 	case NL80211_IFTYPE_NAN:
977 		cfg80211_stop_nan(rdev, wdev);
978 		break;
979 	default:
980 		WARN_ON_ONCE(1);
981 		break;
982 	}
983 }
984 EXPORT_SYMBOL(cfg80211_unregister_wdev);
985 
986 static const struct device_type wiphy_type = {
987 	.name	= "wlan",
988 };
989 
990 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
991 			       enum nl80211_iftype iftype, int num)
992 {
993 	ASSERT_RTNL();
994 
995 	rdev->num_running_ifaces += num;
996 	if (iftype == NL80211_IFTYPE_MONITOR)
997 		rdev->num_running_monitor_ifaces += num;
998 }
999 
1000 void __cfg80211_leave(struct cfg80211_registered_device *rdev,
1001 		      struct wireless_dev *wdev)
1002 {
1003 	struct net_device *dev = wdev->netdev;
1004 	struct cfg80211_sched_scan_request *sched_scan_req;
1005 
1006 	ASSERT_RTNL();
1007 	ASSERT_WDEV_LOCK(wdev);
1008 
1009 	switch (wdev->iftype) {
1010 	case NL80211_IFTYPE_ADHOC:
1011 		__cfg80211_leave_ibss(rdev, dev, true);
1012 		break;
1013 	case NL80211_IFTYPE_P2P_CLIENT:
1014 	case NL80211_IFTYPE_STATION:
1015 		sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
1016 		if (sched_scan_req && dev == sched_scan_req->dev)
1017 			__cfg80211_stop_sched_scan(rdev, false);
1018 
1019 #ifdef CONFIG_CFG80211_WEXT
1020 		kfree(wdev->wext.ie);
1021 		wdev->wext.ie = NULL;
1022 		wdev->wext.ie_len = 0;
1023 		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
1024 #endif
1025 		cfg80211_disconnect(rdev, dev,
1026 				    WLAN_REASON_DEAUTH_LEAVING, true);
1027 		break;
1028 	case NL80211_IFTYPE_MESH_POINT:
1029 		__cfg80211_leave_mesh(rdev, dev);
1030 		break;
1031 	case NL80211_IFTYPE_AP:
1032 	case NL80211_IFTYPE_P2P_GO:
1033 		__cfg80211_stop_ap(rdev, dev, true);
1034 		break;
1035 	case NL80211_IFTYPE_OCB:
1036 		__cfg80211_leave_ocb(rdev, dev);
1037 		break;
1038 	case NL80211_IFTYPE_WDS:
1039 		/* must be handled by mac80211/driver, has no APIs */
1040 		break;
1041 	case NL80211_IFTYPE_P2P_DEVICE:
1042 	case NL80211_IFTYPE_NAN:
1043 		/* cannot happen, has no netdev */
1044 		break;
1045 	case NL80211_IFTYPE_AP_VLAN:
1046 	case NL80211_IFTYPE_MONITOR:
1047 		/* nothing to do */
1048 		break;
1049 	case NL80211_IFTYPE_UNSPECIFIED:
1050 	case NUM_NL80211_IFTYPES:
1051 		/* invalid */
1052 		break;
1053 	}
1054 }
1055 
1056 void cfg80211_leave(struct cfg80211_registered_device *rdev,
1057 		    struct wireless_dev *wdev)
1058 {
1059 	wdev_lock(wdev);
1060 	__cfg80211_leave(rdev, wdev);
1061 	wdev_unlock(wdev);
1062 }
1063 
1064 void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
1065 			 gfp_t gfp)
1066 {
1067 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1068 	struct cfg80211_event *ev;
1069 	unsigned long flags;
1070 
1071 	trace_cfg80211_stop_iface(wiphy, wdev);
1072 
1073 	ev = kzalloc(sizeof(*ev), gfp);
1074 	if (!ev)
1075 		return;
1076 
1077 	ev->type = EVENT_STOPPED;
1078 
1079 	spin_lock_irqsave(&wdev->event_lock, flags);
1080 	list_add_tail(&ev->list, &wdev->event_list);
1081 	spin_unlock_irqrestore(&wdev->event_lock, flags);
1082 	queue_work(cfg80211_wq, &rdev->event_work);
1083 }
1084 EXPORT_SYMBOL(cfg80211_stop_iface);
1085 
1086 static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
1087 					 unsigned long state, void *ptr)
1088 {
1089 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1090 	struct wireless_dev *wdev = dev->ieee80211_ptr;
1091 	struct cfg80211_registered_device *rdev;
1092 	struct cfg80211_sched_scan_request *sched_scan_req;
1093 
1094 	if (!wdev)
1095 		return NOTIFY_DONE;
1096 
1097 	rdev = wiphy_to_rdev(wdev->wiphy);
1098 
1099 	WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
1100 
1101 	switch (state) {
1102 	case NETDEV_POST_INIT:
1103 		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
1104 		break;
1105 	case NETDEV_REGISTER:
1106 		/*
1107 		 * NB: cannot take rdev->mtx here because this may be
1108 		 * called within code protected by it when interfaces
1109 		 * are added with nl80211.
1110 		 */
1111 		mutex_init(&wdev->mtx);
1112 		INIT_LIST_HEAD(&wdev->event_list);
1113 		spin_lock_init(&wdev->event_lock);
1114 		INIT_LIST_HEAD(&wdev->mgmt_registrations);
1115 		spin_lock_init(&wdev->mgmt_registrations_lock);
1116 
1117 		wdev->identifier = ++rdev->wdev_id;
1118 		list_add_rcu(&wdev->list, &rdev->wiphy.wdev_list);
1119 		rdev->devlist_generation++;
1120 		/* can only change netns with wiphy */
1121 		dev->features |= NETIF_F_NETNS_LOCAL;
1122 
1123 		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
1124 				      "phy80211")) {
1125 			pr_err("failed to add phy80211 symlink to netdev!\n");
1126 		}
1127 		wdev->netdev = dev;
1128 #ifdef CONFIG_CFG80211_WEXT
1129 		wdev->wext.default_key = -1;
1130 		wdev->wext.default_mgmt_key = -1;
1131 		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
1132 #endif
1133 
1134 		if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
1135 			wdev->ps = true;
1136 		else
1137 			wdev->ps = false;
1138 		/* allow mac80211 to determine the timeout */
1139 		wdev->ps_timeout = -1;
1140 
1141 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
1142 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
1143 		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
1144 			dev->priv_flags |= IFF_DONT_BRIDGE;
1145 
1146 		INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk);
1147 
1148 		nl80211_notify_iface(rdev, wdev, NL80211_CMD_NEW_INTERFACE);
1149 		break;
1150 	case NETDEV_GOING_DOWN:
1151 		cfg80211_leave(rdev, wdev);
1152 		break;
1153 	case NETDEV_DOWN:
1154 		cfg80211_update_iface_num(rdev, wdev->iftype, -1);
1155 		if (rdev->scan_req && rdev->scan_req->wdev == wdev) {
1156 			if (WARN_ON(!rdev->scan_req->notified))
1157 				rdev->scan_req->info.aborted = true;
1158 			___cfg80211_scan_done(rdev, false);
1159 		}
1160 
1161 		sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
1162 		if (WARN_ON(sched_scan_req &&
1163 			    sched_scan_req->dev == wdev->netdev)) {
1164 			__cfg80211_stop_sched_scan(rdev, false);
1165 		}
1166 
1167 		rdev->opencount--;
1168 		wake_up(&rdev->dev_wait);
1169 		break;
1170 	case NETDEV_UP:
1171 		cfg80211_update_iface_num(rdev, wdev->iftype, 1);
1172 		wdev_lock(wdev);
1173 		switch (wdev->iftype) {
1174 #ifdef CONFIG_CFG80211_WEXT
1175 		case NL80211_IFTYPE_ADHOC:
1176 			cfg80211_ibss_wext_join(rdev, wdev);
1177 			break;
1178 		case NL80211_IFTYPE_STATION:
1179 			cfg80211_mgd_wext_connect(rdev, wdev);
1180 			break;
1181 #endif
1182 #ifdef CONFIG_MAC80211_MESH
1183 		case NL80211_IFTYPE_MESH_POINT:
1184 			{
1185 				/* backward compat code... */
1186 				struct mesh_setup setup;
1187 				memcpy(&setup, &default_mesh_setup,
1188 						sizeof(setup));
1189 				 /* back compat only needed for mesh_id */
1190 				setup.mesh_id = wdev->ssid;
1191 				setup.mesh_id_len = wdev->mesh_id_up_len;
1192 				if (wdev->mesh_id_up_len)
1193 					__cfg80211_join_mesh(rdev, dev,
1194 							&setup,
1195 							&default_mesh_config);
1196 				break;
1197 			}
1198 #endif
1199 		default:
1200 			break;
1201 		}
1202 		wdev_unlock(wdev);
1203 		rdev->opencount++;
1204 
1205 		/*
1206 		 * Configure power management to the driver here so that its
1207 		 * correctly set also after interface type changes etc.
1208 		 */
1209 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
1210 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
1211 		    rdev->ops->set_power_mgmt)
1212 			if (rdev_set_power_mgmt(rdev, dev, wdev->ps,
1213 						wdev->ps_timeout)) {
1214 				/* assume this means it's off */
1215 				wdev->ps = false;
1216 			}
1217 		break;
1218 	case NETDEV_UNREGISTER:
1219 		/*
1220 		 * It is possible to get NETDEV_UNREGISTER
1221 		 * multiple times. To detect that, check
1222 		 * that the interface is still on the list
1223 		 * of registered interfaces, and only then
1224 		 * remove and clean it up.
1225 		 */
1226 		if (!list_empty(&wdev->list)) {
1227 			nl80211_notify_iface(rdev, wdev,
1228 					     NL80211_CMD_DEL_INTERFACE);
1229 			sysfs_remove_link(&dev->dev.kobj, "phy80211");
1230 			list_del_rcu(&wdev->list);
1231 			rdev->devlist_generation++;
1232 			cfg80211_mlme_purge_registrations(wdev);
1233 #ifdef CONFIG_CFG80211_WEXT
1234 			kzfree(wdev->wext.keys);
1235 #endif
1236 			flush_work(&wdev->disconnect_wk);
1237 		}
1238 		/*
1239 		 * synchronise (so that we won't find this netdev
1240 		 * from other code any more) and then clear the list
1241 		 * head so that the above code can safely check for
1242 		 * !list_empty() to avoid double-cleanup.
1243 		 */
1244 		synchronize_rcu();
1245 		INIT_LIST_HEAD(&wdev->list);
1246 		/*
1247 		 * Ensure that all events have been processed and
1248 		 * freed.
1249 		 */
1250 		cfg80211_process_wdev_events(wdev);
1251 
1252 		if (WARN_ON(wdev->current_bss)) {
1253 			cfg80211_unhold_bss(wdev->current_bss);
1254 			cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
1255 			wdev->current_bss = NULL;
1256 		}
1257 		break;
1258 	case NETDEV_PRE_UP:
1259 		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
1260 			return notifier_from_errno(-EOPNOTSUPP);
1261 		if (rfkill_blocked(rdev->rfkill))
1262 			return notifier_from_errno(-ERFKILL);
1263 		break;
1264 	default:
1265 		return NOTIFY_DONE;
1266 	}
1267 
1268 	wireless_nlevent_flush();
1269 
1270 	return NOTIFY_OK;
1271 }
1272 
1273 static struct notifier_block cfg80211_netdev_notifier = {
1274 	.notifier_call = cfg80211_netdev_notifier_call,
1275 };
1276 
1277 static void __net_exit cfg80211_pernet_exit(struct net *net)
1278 {
1279 	struct cfg80211_registered_device *rdev;
1280 
1281 	rtnl_lock();
1282 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
1283 		if (net_eq(wiphy_net(&rdev->wiphy), net))
1284 			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
1285 	}
1286 	rtnl_unlock();
1287 }
1288 
1289 static struct pernet_operations cfg80211_pernet_ops = {
1290 	.exit = cfg80211_pernet_exit,
1291 };
1292 
1293 static int __init cfg80211_init(void)
1294 {
1295 	int err;
1296 
1297 	err = register_pernet_device(&cfg80211_pernet_ops);
1298 	if (err)
1299 		goto out_fail_pernet;
1300 
1301 	err = wiphy_sysfs_init();
1302 	if (err)
1303 		goto out_fail_sysfs;
1304 
1305 	err = register_netdevice_notifier(&cfg80211_netdev_notifier);
1306 	if (err)
1307 		goto out_fail_notifier;
1308 
1309 	err = nl80211_init();
1310 	if (err)
1311 		goto out_fail_nl80211;
1312 
1313 	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
1314 
1315 	err = regulatory_init();
1316 	if (err)
1317 		goto out_fail_reg;
1318 
1319 	cfg80211_wq = alloc_ordered_workqueue("cfg80211", WQ_MEM_RECLAIM);
1320 	if (!cfg80211_wq) {
1321 		err = -ENOMEM;
1322 		goto out_fail_wq;
1323 	}
1324 
1325 	return 0;
1326 
1327 out_fail_wq:
1328 	regulatory_exit();
1329 out_fail_reg:
1330 	debugfs_remove(ieee80211_debugfs_dir);
1331 	nl80211_exit();
1332 out_fail_nl80211:
1333 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1334 out_fail_notifier:
1335 	wiphy_sysfs_exit();
1336 out_fail_sysfs:
1337 	unregister_pernet_device(&cfg80211_pernet_ops);
1338 out_fail_pernet:
1339 	return err;
1340 }
1341 subsys_initcall(cfg80211_init);
1342 
1343 static void __exit cfg80211_exit(void)
1344 {
1345 	debugfs_remove(ieee80211_debugfs_dir);
1346 	nl80211_exit();
1347 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1348 	wiphy_sysfs_exit();
1349 	regulatory_exit();
1350 	unregister_pernet_device(&cfg80211_pernet_ops);
1351 	destroy_workqueue(cfg80211_wq);
1352 }
1353 module_exit(cfg80211_exit);
1354