xref: /openbmc/linux/net/wireless/core.c (revision 05bcf503)
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 struct cfg80211_registered_device *
100 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
101 {
102 	struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV);
103 	struct net_device *dev;
104 
105 	mutex_lock(&cfg80211_mutex);
106 	dev = dev_get_by_index(net, ifindex);
107 	if (!dev)
108 		goto out;
109 	if (dev->ieee80211_ptr) {
110 		rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
111 		mutex_lock(&rdev->mtx);
112 	} else
113 		rdev = ERR_PTR(-ENODEV);
114 	dev_put(dev);
115  out:
116 	mutex_unlock(&cfg80211_mutex);
117 	return rdev;
118 }
119 
120 /* requires cfg80211_mutex to be held */
121 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
122 			char *newname)
123 {
124 	struct cfg80211_registered_device *rdev2;
125 	int wiphy_idx, taken = -1, result, digits;
126 
127 	assert_cfg80211_lock();
128 
129 	/* prohibit calling the thing phy%d when %d is not its number */
130 	sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
131 	if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
132 		/* count number of places needed to print wiphy_idx */
133 		digits = 1;
134 		while (wiphy_idx /= 10)
135 			digits++;
136 		/*
137 		 * deny the name if it is phy<idx> where <idx> is printed
138 		 * without leading zeroes. taken == strlen(newname) here
139 		 */
140 		if (taken == strlen(PHY_NAME) + digits)
141 			return -EINVAL;
142 	}
143 
144 
145 	/* Ignore nop renames */
146 	if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
147 		return 0;
148 
149 	/* Ensure another device does not already have this name. */
150 	list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
151 		if (strcmp(newname, dev_name(&rdev2->wiphy.dev)) == 0)
152 			return -EINVAL;
153 
154 	result = device_rename(&rdev->wiphy.dev, newname);
155 	if (result)
156 		return result;
157 
158 	if (rdev->wiphy.debugfsdir &&
159 	    !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
160 			    rdev->wiphy.debugfsdir,
161 			    rdev->wiphy.debugfsdir->d_parent,
162 			    newname))
163 		pr_err("failed to rename debugfs dir to %s!\n", newname);
164 
165 	nl80211_notify_dev_rename(rdev);
166 
167 	return 0;
168 }
169 
170 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
171 			  struct net *net)
172 {
173 	struct wireless_dev *wdev;
174 	int err = 0;
175 
176 	if (!(rdev->wiphy.flags & WIPHY_FLAG_NETNS_OK))
177 		return -EOPNOTSUPP;
178 
179 	list_for_each_entry(wdev, &rdev->wdev_list, list) {
180 		if (!wdev->netdev)
181 			continue;
182 		wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
183 		err = dev_change_net_namespace(wdev->netdev, net, "wlan%d");
184 		if (err)
185 			break;
186 		wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
187 	}
188 
189 	if (err) {
190 		/* failed -- clean up to old netns */
191 		net = wiphy_net(&rdev->wiphy);
192 
193 		list_for_each_entry_continue_reverse(wdev, &rdev->wdev_list,
194 						     list) {
195 			if (!wdev->netdev)
196 				continue;
197 			wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
198 			err = dev_change_net_namespace(wdev->netdev, net,
199 							"wlan%d");
200 			WARN_ON(err);
201 			wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
202 		}
203 
204 		return err;
205 	}
206 
207 	wiphy_net_set(&rdev->wiphy, net);
208 
209 	err = device_rename(&rdev->wiphy.dev, dev_name(&rdev->wiphy.dev));
210 	WARN_ON(err);
211 
212 	return 0;
213 }
214 
215 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
216 {
217 	struct cfg80211_registered_device *rdev = data;
218 
219 	rdev->ops->rfkill_poll(&rdev->wiphy);
220 }
221 
222 static int cfg80211_rfkill_set_block(void *data, bool blocked)
223 {
224 	struct cfg80211_registered_device *rdev = data;
225 	struct wireless_dev *wdev;
226 
227 	if (!blocked)
228 		return 0;
229 
230 	rtnl_lock();
231 	mutex_lock(&rdev->devlist_mtx);
232 
233 	list_for_each_entry(wdev, &rdev->wdev_list, list) {
234 		if (wdev->netdev) {
235 			dev_close(wdev->netdev);
236 			continue;
237 		}
238 		/* otherwise, check iftype */
239 		switch (wdev->iftype) {
240 		case NL80211_IFTYPE_P2P_DEVICE:
241 			if (!wdev->p2p_started)
242 				break;
243 			rdev->ops->stop_p2p_device(&rdev->wiphy, wdev);
244 			wdev->p2p_started = false;
245 			rdev->opencount--;
246 			break;
247 		default:
248 			break;
249 		}
250 	}
251 
252 	mutex_unlock(&rdev->devlist_mtx);
253 	rtnl_unlock();
254 
255 	return 0;
256 }
257 
258 static void cfg80211_rfkill_sync_work(struct work_struct *work)
259 {
260 	struct cfg80211_registered_device *rdev;
261 
262 	rdev = container_of(work, struct cfg80211_registered_device, rfkill_sync);
263 	cfg80211_rfkill_set_block(rdev, rfkill_blocked(rdev->rfkill));
264 }
265 
266 static void cfg80211_event_work(struct work_struct *work)
267 {
268 	struct cfg80211_registered_device *rdev;
269 
270 	rdev = container_of(work, struct cfg80211_registered_device,
271 			    event_work);
272 
273 	rtnl_lock();
274 	cfg80211_lock_rdev(rdev);
275 
276 	cfg80211_process_rdev_events(rdev);
277 	cfg80211_unlock_rdev(rdev);
278 	rtnl_unlock();
279 }
280 
281 /* exported functions */
282 
283 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
284 {
285 	static int wiphy_counter;
286 
287 	struct cfg80211_registered_device *rdev;
288 	int alloc_size;
289 
290 	WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
291 	WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
292 	WARN_ON(ops->connect && !ops->disconnect);
293 	WARN_ON(ops->join_ibss && !ops->leave_ibss);
294 	WARN_ON(ops->add_virtual_intf && !ops->del_virtual_intf);
295 	WARN_ON(ops->add_station && !ops->del_station);
296 	WARN_ON(ops->add_mpath && !ops->del_mpath);
297 	WARN_ON(ops->join_mesh && !ops->leave_mesh);
298 
299 	alloc_size = sizeof(*rdev) + sizeof_priv;
300 
301 	rdev = kzalloc(alloc_size, GFP_KERNEL);
302 	if (!rdev)
303 		return NULL;
304 
305 	rdev->ops = ops;
306 
307 	mutex_lock(&cfg80211_mutex);
308 
309 	rdev->wiphy_idx = wiphy_counter++;
310 
311 	if (unlikely(!wiphy_idx_valid(rdev->wiphy_idx))) {
312 		wiphy_counter--;
313 		mutex_unlock(&cfg80211_mutex);
314 		/* ugh, wrapped! */
315 		kfree(rdev);
316 		return NULL;
317 	}
318 
319 	mutex_unlock(&cfg80211_mutex);
320 
321 	/* give it a proper name */
322 	dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
323 
324 	mutex_init(&rdev->mtx);
325 	mutex_init(&rdev->devlist_mtx);
326 	mutex_init(&rdev->sched_scan_mtx);
327 	INIT_LIST_HEAD(&rdev->wdev_list);
328 	spin_lock_init(&rdev->bss_lock);
329 	INIT_LIST_HEAD(&rdev->bss_list);
330 	INIT_WORK(&rdev->scan_done_wk, __cfg80211_scan_done);
331 	INIT_WORK(&rdev->sched_scan_results_wk, __cfg80211_sched_scan_results);
332 #ifdef CONFIG_CFG80211_WEXT
333 	rdev->wiphy.wext = &cfg80211_wext_handler;
334 #endif
335 
336 	device_initialize(&rdev->wiphy.dev);
337 	rdev->wiphy.dev.class = &ieee80211_class;
338 	rdev->wiphy.dev.platform_data = rdev;
339 
340 #ifdef CONFIG_CFG80211_DEFAULT_PS
341 	rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
342 #endif
343 
344 	wiphy_net_set(&rdev->wiphy, &init_net);
345 
346 	rdev->rfkill_ops.set_block = cfg80211_rfkill_set_block;
347 	rdev->rfkill = rfkill_alloc(dev_name(&rdev->wiphy.dev),
348 				   &rdev->wiphy.dev, RFKILL_TYPE_WLAN,
349 				   &rdev->rfkill_ops, rdev);
350 
351 	if (!rdev->rfkill) {
352 		kfree(rdev);
353 		return NULL;
354 	}
355 
356 	INIT_WORK(&rdev->rfkill_sync, cfg80211_rfkill_sync_work);
357 	INIT_WORK(&rdev->conn_work, cfg80211_conn_work);
358 	INIT_WORK(&rdev->event_work, cfg80211_event_work);
359 
360 	init_waitqueue_head(&rdev->dev_wait);
361 
362 	/*
363 	 * Initialize wiphy parameters to IEEE 802.11 MIB default values.
364 	 * Fragmentation and RTS threshold are disabled by default with the
365 	 * special -1 value.
366 	 */
367 	rdev->wiphy.retry_short = 7;
368 	rdev->wiphy.retry_long = 4;
369 	rdev->wiphy.frag_threshold = (u32) -1;
370 	rdev->wiphy.rts_threshold = (u32) -1;
371 	rdev->wiphy.coverage_class = 0;
372 
373 	return &rdev->wiphy;
374 }
375 EXPORT_SYMBOL(wiphy_new);
376 
377 static int wiphy_verify_combinations(struct wiphy *wiphy)
378 {
379 	const struct ieee80211_iface_combination *c;
380 	int i, j;
381 
382 	for (i = 0; i < wiphy->n_iface_combinations; i++) {
383 		u32 cnt = 0;
384 		u16 all_iftypes = 0;
385 
386 		c = &wiphy->iface_combinations[i];
387 
388 		/* Combinations with just one interface aren't real */
389 		if (WARN_ON(c->max_interfaces < 2))
390 			return -EINVAL;
391 
392 		/* Need at least one channel */
393 		if (WARN_ON(!c->num_different_channels))
394 			return -EINVAL;
395 
396 		/*
397 		 * Put a sane limit on maximum number of different
398 		 * channels to simplify channel accounting code.
399 		 */
400 		if (WARN_ON(c->num_different_channels >
401 				CFG80211_MAX_NUM_DIFFERENT_CHANNELS))
402 			return -EINVAL;
403 
404 		if (WARN_ON(!c->n_limits))
405 			return -EINVAL;
406 
407 		for (j = 0; j < c->n_limits; j++) {
408 			u16 types = c->limits[j].types;
409 
410 			/*
411 			 * interface types shouldn't overlap, this is
412 			 * used in cfg80211_can_change_interface()
413 			 */
414 			if (WARN_ON(types & all_iftypes))
415 				return -EINVAL;
416 			all_iftypes |= types;
417 
418 			if (WARN_ON(!c->limits[j].max))
419 				return -EINVAL;
420 
421 			/* Shouldn't list software iftypes in combinations! */
422 			if (WARN_ON(wiphy->software_iftypes & types))
423 				return -EINVAL;
424 
425 			/* Only a single P2P_DEVICE can be allowed */
426 			if (WARN_ON(types & BIT(NL80211_IFTYPE_P2P_DEVICE) &&
427 				    c->limits[j].max > 1))
428 				return -EINVAL;
429 
430 			cnt += c->limits[j].max;
431 			/*
432 			 * Don't advertise an unsupported type
433 			 * in a combination.
434 			 */
435 			if (WARN_ON((wiphy->interface_modes & types) != types))
436 				return -EINVAL;
437 		}
438 
439 		/* You can't even choose that many! */
440 		if (WARN_ON(cnt < c->max_interfaces))
441 			return -EINVAL;
442 	}
443 
444 	return 0;
445 }
446 
447 int wiphy_register(struct wiphy *wiphy)
448 {
449 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
450 	int res;
451 	enum ieee80211_band band;
452 	struct ieee80211_supported_band *sband;
453 	bool have_band = false;
454 	int i;
455 	u16 ifmodes = wiphy->interface_modes;
456 
457 #ifdef CONFIG_PM
458 	if (WARN_ON((wiphy->wowlan.flags & WIPHY_WOWLAN_GTK_REKEY_FAILURE) &&
459 		    !(wiphy->wowlan.flags & WIPHY_WOWLAN_SUPPORTS_GTK_REKEY)))
460 		return -EINVAL;
461 #endif
462 
463 	if (WARN_ON(wiphy->ap_sme_capa &&
464 		    !(wiphy->flags & WIPHY_FLAG_HAVE_AP_SME)))
465 		return -EINVAL;
466 
467 	if (WARN_ON(wiphy->addresses && !wiphy->n_addresses))
468 		return -EINVAL;
469 
470 	if (WARN_ON(wiphy->addresses &&
471 		    !is_zero_ether_addr(wiphy->perm_addr) &&
472 		    memcmp(wiphy->perm_addr, wiphy->addresses[0].addr,
473 			   ETH_ALEN)))
474 		return -EINVAL;
475 
476 	if (wiphy->addresses)
477 		memcpy(wiphy->perm_addr, wiphy->addresses[0].addr, ETH_ALEN);
478 
479 	/* sanity check ifmodes */
480 	WARN_ON(!ifmodes);
481 	ifmodes &= ((1 << NUM_NL80211_IFTYPES) - 1) & ~1;
482 	if (WARN_ON(ifmodes != wiphy->interface_modes))
483 		wiphy->interface_modes = ifmodes;
484 
485 	res = wiphy_verify_combinations(wiphy);
486 	if (res)
487 		return res;
488 
489 	/* sanity check supported bands/channels */
490 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
491 		sband = wiphy->bands[band];
492 		if (!sband)
493 			continue;
494 
495 		sband->band = band;
496 		if (WARN_ON(!sband->n_channels))
497 			return -EINVAL;
498 		/*
499 		 * on 60gHz band, there are no legacy rates, so
500 		 * n_bitrates is 0
501 		 */
502 		if (WARN_ON(band != IEEE80211_BAND_60GHZ &&
503 			    !sband->n_bitrates))
504 			return -EINVAL;
505 
506 		/*
507 		 * Since cfg80211_disable_40mhz_24ghz is global, we can
508 		 * modify the sband's ht data even if the driver uses a
509 		 * global structure for that.
510 		 */
511 		if (cfg80211_disable_40mhz_24ghz &&
512 		    band == IEEE80211_BAND_2GHZ &&
513 		    sband->ht_cap.ht_supported) {
514 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
515 			sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
516 		}
517 
518 		/*
519 		 * Since we use a u32 for rate bitmaps in
520 		 * ieee80211_get_response_rate, we cannot
521 		 * have more than 32 legacy rates.
522 		 */
523 		if (WARN_ON(sband->n_bitrates > 32))
524 			return -EINVAL;
525 
526 		for (i = 0; i < sband->n_channels; i++) {
527 			sband->channels[i].orig_flags =
528 				sband->channels[i].flags;
529 			sband->channels[i].orig_mag = INT_MAX;
530 			sband->channels[i].orig_mpwr =
531 				sband->channels[i].max_power;
532 			sband->channels[i].band = band;
533 		}
534 
535 		have_band = true;
536 	}
537 
538 	if (!have_band) {
539 		WARN_ON(1);
540 		return -EINVAL;
541 	}
542 
543 #ifdef CONFIG_PM
544 	if (rdev->wiphy.wowlan.n_patterns) {
545 		if (WARN_ON(!rdev->wiphy.wowlan.pattern_min_len ||
546 			    rdev->wiphy.wowlan.pattern_min_len >
547 			    rdev->wiphy.wowlan.pattern_max_len))
548 			return -EINVAL;
549 	}
550 #endif
551 
552 	/* check and set up bitrates */
553 	ieee80211_set_bitrate_flags(wiphy);
554 
555 	mutex_lock(&cfg80211_mutex);
556 
557 	res = device_add(&rdev->wiphy.dev);
558 	if (res) {
559 		mutex_unlock(&cfg80211_mutex);
560 		return res;
561 	}
562 
563 	/* set up regulatory info */
564 	wiphy_regulatory_register(wiphy);
565 
566 	list_add_rcu(&rdev->list, &cfg80211_rdev_list);
567 	cfg80211_rdev_list_generation++;
568 
569 	/* add to debugfs */
570 	rdev->wiphy.debugfsdir =
571 		debugfs_create_dir(wiphy_name(&rdev->wiphy),
572 				   ieee80211_debugfs_dir);
573 	if (IS_ERR(rdev->wiphy.debugfsdir))
574 		rdev->wiphy.debugfsdir = NULL;
575 
576 	if (wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY) {
577 		struct regulatory_request request;
578 
579 		request.wiphy_idx = get_wiphy_idx(wiphy);
580 		request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
581 		request.alpha2[0] = '9';
582 		request.alpha2[1] = '9';
583 
584 		nl80211_send_reg_change_event(&request);
585 	}
586 
587 	cfg80211_debugfs_rdev_add(rdev);
588 	mutex_unlock(&cfg80211_mutex);
589 
590 	/*
591 	 * due to a locking dependency this has to be outside of the
592 	 * cfg80211_mutex lock
593 	 */
594 	res = rfkill_register(rdev->rfkill);
595 	if (res)
596 		goto out_rm_dev;
597 
598 	rtnl_lock();
599 	rdev->wiphy.registered = true;
600 	rtnl_unlock();
601 	return 0;
602 
603 out_rm_dev:
604 	device_del(&rdev->wiphy.dev);
605 	return res;
606 }
607 EXPORT_SYMBOL(wiphy_register);
608 
609 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
610 {
611 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
612 
613 	if (!rdev->ops->rfkill_poll)
614 		return;
615 	rdev->rfkill_ops.poll = cfg80211_rfkill_poll;
616 	rfkill_resume_polling(rdev->rfkill);
617 }
618 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
619 
620 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
621 {
622 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
623 
624 	rfkill_pause_polling(rdev->rfkill);
625 }
626 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
627 
628 void wiphy_unregister(struct wiphy *wiphy)
629 {
630 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
631 
632 	rtnl_lock();
633 	rdev->wiphy.registered = false;
634 	rtnl_unlock();
635 
636 	rfkill_unregister(rdev->rfkill);
637 
638 	/* protect the device list */
639 	mutex_lock(&cfg80211_mutex);
640 
641 	wait_event(rdev->dev_wait, ({
642 		int __count;
643 		mutex_lock(&rdev->devlist_mtx);
644 		__count = rdev->opencount;
645 		mutex_unlock(&rdev->devlist_mtx);
646 		__count == 0; }));
647 
648 	mutex_lock(&rdev->devlist_mtx);
649 	BUG_ON(!list_empty(&rdev->wdev_list));
650 	mutex_unlock(&rdev->devlist_mtx);
651 
652 	/*
653 	 * First remove the hardware from everywhere, this makes
654 	 * it impossible to find from userspace.
655 	 */
656 	debugfs_remove_recursive(rdev->wiphy.debugfsdir);
657 	list_del_rcu(&rdev->list);
658 	synchronize_rcu();
659 
660 	/*
661 	 * Try to grab rdev->mtx. If a command is still in progress,
662 	 * hopefully the driver will refuse it since it's tearing
663 	 * down the device already. We wait for this command to complete
664 	 * before unlinking the item from the list.
665 	 * Note: as codified by the BUG_ON above we cannot get here if
666 	 * a virtual interface is still present. Hence, we can only get
667 	 * to lock contention here if userspace issues a command that
668 	 * identified the hardware by wiphy index.
669 	 */
670 	cfg80211_lock_rdev(rdev);
671 	/* nothing */
672 	cfg80211_unlock_rdev(rdev);
673 
674 	/*
675 	 * If this device got a regulatory hint tell core its
676 	 * free to listen now to a new shiny device regulatory hint
677 	 */
678 	wiphy_regulatory_deregister(wiphy);
679 
680 	cfg80211_rdev_list_generation++;
681 	device_del(&rdev->wiphy.dev);
682 
683 	mutex_unlock(&cfg80211_mutex);
684 
685 	flush_work(&rdev->scan_done_wk);
686 	cancel_work_sync(&rdev->conn_work);
687 	flush_work(&rdev->event_work);
688 
689 	if (rdev->wowlan && rdev->ops->set_wakeup)
690 		rdev->ops->set_wakeup(&rdev->wiphy, false);
691 	cfg80211_rdev_free_wowlan(rdev);
692 }
693 EXPORT_SYMBOL(wiphy_unregister);
694 
695 void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
696 {
697 	struct cfg80211_internal_bss *scan, *tmp;
698 	rfkill_destroy(rdev->rfkill);
699 	mutex_destroy(&rdev->mtx);
700 	mutex_destroy(&rdev->devlist_mtx);
701 	mutex_destroy(&rdev->sched_scan_mtx);
702 	list_for_each_entry_safe(scan, tmp, &rdev->bss_list, list)
703 		cfg80211_put_bss(&scan->pub);
704 	kfree(rdev);
705 }
706 
707 void wiphy_free(struct wiphy *wiphy)
708 {
709 	put_device(&wiphy->dev);
710 }
711 EXPORT_SYMBOL(wiphy_free);
712 
713 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
714 {
715 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
716 
717 	if (rfkill_set_hw_state(rdev->rfkill, blocked))
718 		schedule_work(&rdev->rfkill_sync);
719 }
720 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
721 
722 static void wdev_cleanup_work(struct work_struct *work)
723 {
724 	struct wireless_dev *wdev;
725 	struct cfg80211_registered_device *rdev;
726 
727 	wdev = container_of(work, struct wireless_dev, cleanup_work);
728 	rdev = wiphy_to_dev(wdev->wiphy);
729 
730 	cfg80211_lock_rdev(rdev);
731 
732 	if (WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev)) {
733 		rdev->scan_req->aborted = true;
734 		___cfg80211_scan_done(rdev, true);
735 	}
736 
737 	cfg80211_unlock_rdev(rdev);
738 
739 	mutex_lock(&rdev->sched_scan_mtx);
740 
741 	if (WARN_ON(rdev->sched_scan_req &&
742 		    rdev->sched_scan_req->dev == wdev->netdev)) {
743 		__cfg80211_stop_sched_scan(rdev, false);
744 	}
745 
746 	mutex_unlock(&rdev->sched_scan_mtx);
747 
748 	mutex_lock(&rdev->devlist_mtx);
749 	rdev->opencount--;
750 	mutex_unlock(&rdev->devlist_mtx);
751 	wake_up(&rdev->dev_wait);
752 
753 	dev_put(wdev->netdev);
754 }
755 
756 void cfg80211_unregister_wdev(struct wireless_dev *wdev)
757 {
758 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
759 
760 	ASSERT_RTNL();
761 
762 	if (WARN_ON(wdev->netdev))
763 		return;
764 
765 	mutex_lock(&rdev->devlist_mtx);
766 	list_del_rcu(&wdev->list);
767 	rdev->devlist_generation++;
768 
769 	switch (wdev->iftype) {
770 	case NL80211_IFTYPE_P2P_DEVICE:
771 		if (!wdev->p2p_started)
772 			break;
773 		rdev->ops->stop_p2p_device(&rdev->wiphy, wdev);
774 		wdev->p2p_started = false;
775 		rdev->opencount--;
776 		break;
777 	default:
778 		WARN_ON_ONCE(1);
779 		break;
780 	}
781 	mutex_unlock(&rdev->devlist_mtx);
782 }
783 EXPORT_SYMBOL(cfg80211_unregister_wdev);
784 
785 static struct device_type wiphy_type = {
786 	.name	= "wlan",
787 };
788 
789 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
790 			       enum nl80211_iftype iftype, int num)
791 {
792 	ASSERT_RTNL();
793 
794 	rdev->num_running_ifaces += num;
795 	if (iftype == NL80211_IFTYPE_MONITOR)
796 		rdev->num_running_monitor_ifaces += num;
797 }
798 
799 static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
800 					 unsigned long state,
801 					 void *ndev)
802 {
803 	struct net_device *dev = ndev;
804 	struct wireless_dev *wdev = dev->ieee80211_ptr;
805 	struct cfg80211_registered_device *rdev;
806 	int ret;
807 
808 	if (!wdev)
809 		return NOTIFY_DONE;
810 
811 	rdev = wiphy_to_dev(wdev->wiphy);
812 
813 	WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
814 
815 	switch (state) {
816 	case NETDEV_POST_INIT:
817 		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
818 		break;
819 	case NETDEV_REGISTER:
820 		/*
821 		 * NB: cannot take rdev->mtx here because this may be
822 		 * called within code protected by it when interfaces
823 		 * are added with nl80211.
824 		 */
825 		mutex_init(&wdev->mtx);
826 		INIT_WORK(&wdev->cleanup_work, wdev_cleanup_work);
827 		INIT_LIST_HEAD(&wdev->event_list);
828 		spin_lock_init(&wdev->event_lock);
829 		INIT_LIST_HEAD(&wdev->mgmt_registrations);
830 		spin_lock_init(&wdev->mgmt_registrations_lock);
831 
832 		mutex_lock(&rdev->devlist_mtx);
833 		wdev->identifier = ++rdev->wdev_id;
834 		list_add_rcu(&wdev->list, &rdev->wdev_list);
835 		rdev->devlist_generation++;
836 		/* can only change netns with wiphy */
837 		dev->features |= NETIF_F_NETNS_LOCAL;
838 
839 		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
840 				      "phy80211")) {
841 			pr_err("failed to add phy80211 symlink to netdev!\n");
842 		}
843 		wdev->netdev = dev;
844 		wdev->sme_state = CFG80211_SME_IDLE;
845 		mutex_unlock(&rdev->devlist_mtx);
846 #ifdef CONFIG_CFG80211_WEXT
847 		wdev->wext.default_key = -1;
848 		wdev->wext.default_mgmt_key = -1;
849 		wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
850 #endif
851 
852 		if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
853 			wdev->ps = true;
854 		else
855 			wdev->ps = false;
856 		/* allow mac80211 to determine the timeout */
857 		wdev->ps_timeout = -1;
858 
859 		if (!dev->ethtool_ops)
860 			dev->ethtool_ops = &cfg80211_ethtool_ops;
861 
862 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
863 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
864 		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
865 			dev->priv_flags |= IFF_DONT_BRIDGE;
866 		break;
867 	case NETDEV_GOING_DOWN:
868 		switch (wdev->iftype) {
869 		case NL80211_IFTYPE_ADHOC:
870 			cfg80211_leave_ibss(rdev, dev, true);
871 			break;
872 		case NL80211_IFTYPE_P2P_CLIENT:
873 		case NL80211_IFTYPE_STATION:
874 			mutex_lock(&rdev->sched_scan_mtx);
875 			__cfg80211_stop_sched_scan(rdev, false);
876 			mutex_unlock(&rdev->sched_scan_mtx);
877 
878 			wdev_lock(wdev);
879 #ifdef CONFIG_CFG80211_WEXT
880 			kfree(wdev->wext.ie);
881 			wdev->wext.ie = NULL;
882 			wdev->wext.ie_len = 0;
883 			wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
884 #endif
885 			__cfg80211_disconnect(rdev, dev,
886 					      WLAN_REASON_DEAUTH_LEAVING, true);
887 			cfg80211_mlme_down(rdev, dev);
888 			wdev_unlock(wdev);
889 			break;
890 		case NL80211_IFTYPE_MESH_POINT:
891 			cfg80211_leave_mesh(rdev, dev);
892 			break;
893 		case NL80211_IFTYPE_AP:
894 			cfg80211_stop_ap(rdev, dev);
895 			break;
896 		default:
897 			break;
898 		}
899 		wdev->beacon_interval = 0;
900 		break;
901 	case NETDEV_DOWN:
902 		cfg80211_update_iface_num(rdev, wdev->iftype, -1);
903 		dev_hold(dev);
904 		queue_work(cfg80211_wq, &wdev->cleanup_work);
905 		break;
906 	case NETDEV_UP:
907 		/*
908 		 * If we have a really quick DOWN/UP succession we may
909 		 * have this work still pending ... cancel it and see
910 		 * if it was pending, in which case we need to account
911 		 * for some of the work it would have done.
912 		 */
913 		if (cancel_work_sync(&wdev->cleanup_work)) {
914 			mutex_lock(&rdev->devlist_mtx);
915 			rdev->opencount--;
916 			mutex_unlock(&rdev->devlist_mtx);
917 			dev_put(dev);
918 		}
919 		cfg80211_update_iface_num(rdev, wdev->iftype, 1);
920 		cfg80211_lock_rdev(rdev);
921 		mutex_lock(&rdev->devlist_mtx);
922 		wdev_lock(wdev);
923 		switch (wdev->iftype) {
924 #ifdef CONFIG_CFG80211_WEXT
925 		case NL80211_IFTYPE_ADHOC:
926 			cfg80211_ibss_wext_join(rdev, wdev);
927 			break;
928 		case NL80211_IFTYPE_STATION:
929 			cfg80211_mgd_wext_connect(rdev, wdev);
930 			break;
931 #endif
932 #ifdef CONFIG_MAC80211_MESH
933 		case NL80211_IFTYPE_MESH_POINT:
934 			{
935 				/* backward compat code... */
936 				struct mesh_setup setup;
937 				memcpy(&setup, &default_mesh_setup,
938 						sizeof(setup));
939 				 /* back compat only needed for mesh_id */
940 				setup.mesh_id = wdev->ssid;
941 				setup.mesh_id_len = wdev->mesh_id_up_len;
942 				if (wdev->mesh_id_up_len)
943 					__cfg80211_join_mesh(rdev, dev,
944 							&setup,
945 							&default_mesh_config);
946 				break;
947 			}
948 #endif
949 		default:
950 			break;
951 		}
952 		wdev_unlock(wdev);
953 		rdev->opencount++;
954 		mutex_unlock(&rdev->devlist_mtx);
955 		cfg80211_unlock_rdev(rdev);
956 
957 		/*
958 		 * Configure power management to the driver here so that its
959 		 * correctly set also after interface type changes etc.
960 		 */
961 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
962 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
963 		    rdev->ops->set_power_mgmt)
964 			if (rdev->ops->set_power_mgmt(wdev->wiphy, dev,
965 						      wdev->ps,
966 						      wdev->ps_timeout)) {
967 				/* assume this means it's off */
968 				wdev->ps = false;
969 			}
970 		break;
971 	case NETDEV_UNREGISTER:
972 		/*
973 		 * NB: cannot take rdev->mtx here because this may be
974 		 * called within code protected by it when interfaces
975 		 * are removed with nl80211.
976 		 */
977 		mutex_lock(&rdev->devlist_mtx);
978 		/*
979 		 * It is possible to get NETDEV_UNREGISTER
980 		 * multiple times. To detect that, check
981 		 * that the interface is still on the list
982 		 * of registered interfaces, and only then
983 		 * remove and clean it up.
984 		 */
985 		if (!list_empty(&wdev->list)) {
986 			sysfs_remove_link(&dev->dev.kobj, "phy80211");
987 			list_del_rcu(&wdev->list);
988 			rdev->devlist_generation++;
989 			cfg80211_mlme_purge_registrations(wdev);
990 #ifdef CONFIG_CFG80211_WEXT
991 			kfree(wdev->wext.keys);
992 #endif
993 		}
994 		mutex_unlock(&rdev->devlist_mtx);
995 		/*
996 		 * synchronise (so that we won't find this netdev
997 		 * from other code any more) and then clear the list
998 		 * head so that the above code can safely check for
999 		 * !list_empty() to avoid double-cleanup.
1000 		 */
1001 		synchronize_rcu();
1002 		INIT_LIST_HEAD(&wdev->list);
1003 		/*
1004 		 * Ensure that all events have been processed and
1005 		 * freed.
1006 		 */
1007 		cfg80211_process_wdev_events(wdev);
1008 		break;
1009 	case NETDEV_PRE_UP:
1010 		if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
1011 			return notifier_from_errno(-EOPNOTSUPP);
1012 		if (rfkill_blocked(rdev->rfkill))
1013 			return notifier_from_errno(-ERFKILL);
1014 		mutex_lock(&rdev->devlist_mtx);
1015 		ret = cfg80211_can_add_interface(rdev, wdev->iftype);
1016 		mutex_unlock(&rdev->devlist_mtx);
1017 		if (ret)
1018 			return notifier_from_errno(ret);
1019 		break;
1020 	}
1021 
1022 	return NOTIFY_DONE;
1023 }
1024 
1025 static struct notifier_block cfg80211_netdev_notifier = {
1026 	.notifier_call = cfg80211_netdev_notifier_call,
1027 };
1028 
1029 static void __net_exit cfg80211_pernet_exit(struct net *net)
1030 {
1031 	struct cfg80211_registered_device *rdev;
1032 
1033 	rtnl_lock();
1034 	mutex_lock(&cfg80211_mutex);
1035 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
1036 		if (net_eq(wiphy_net(&rdev->wiphy), net))
1037 			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
1038 	}
1039 	mutex_unlock(&cfg80211_mutex);
1040 	rtnl_unlock();
1041 }
1042 
1043 static struct pernet_operations cfg80211_pernet_ops = {
1044 	.exit = cfg80211_pernet_exit,
1045 };
1046 
1047 static int __init cfg80211_init(void)
1048 {
1049 	int err;
1050 
1051 	err = register_pernet_device(&cfg80211_pernet_ops);
1052 	if (err)
1053 		goto out_fail_pernet;
1054 
1055 	err = wiphy_sysfs_init();
1056 	if (err)
1057 		goto out_fail_sysfs;
1058 
1059 	err = register_netdevice_notifier(&cfg80211_netdev_notifier);
1060 	if (err)
1061 		goto out_fail_notifier;
1062 
1063 	err = nl80211_init();
1064 	if (err)
1065 		goto out_fail_nl80211;
1066 
1067 	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
1068 
1069 	err = regulatory_init();
1070 	if (err)
1071 		goto out_fail_reg;
1072 
1073 	cfg80211_wq = create_singlethread_workqueue("cfg80211");
1074 	if (!cfg80211_wq)
1075 		goto out_fail_wq;
1076 
1077 	return 0;
1078 
1079 out_fail_wq:
1080 	regulatory_exit();
1081 out_fail_reg:
1082 	debugfs_remove(ieee80211_debugfs_dir);
1083 out_fail_nl80211:
1084 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1085 out_fail_notifier:
1086 	wiphy_sysfs_exit();
1087 out_fail_sysfs:
1088 	unregister_pernet_device(&cfg80211_pernet_ops);
1089 out_fail_pernet:
1090 	return err;
1091 }
1092 subsys_initcall(cfg80211_init);
1093 
1094 static void __exit cfg80211_exit(void)
1095 {
1096 	debugfs_remove(ieee80211_debugfs_dir);
1097 	nl80211_exit();
1098 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1099 	wiphy_sysfs_exit();
1100 	regulatory_exit();
1101 	unregister_pernet_device(&cfg80211_pernet_ops);
1102 	destroy_workqueue(cfg80211_wq);
1103 }
1104 module_exit(cfg80211_exit);
1105