xref: /linux/net/wireless/chan.c (revision 83a37b3292f4aca799b355179ad6fbdd78a08e10)
1 /*
2  * This file contains helper code to handle channel
3  * settings and keeping track of what is possible at
4  * any point in time.
5  *
6  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
7  * Copyright 2013-2014  Intel Mobile Communications GmbH
8  */
9 
10 #include <linux/export.h>
11 #include <net/cfg80211.h>
12 #include "core.h"
13 #include "rdev-ops.h"
14 
15 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
16 			     struct ieee80211_channel *chan,
17 			     enum nl80211_channel_type chan_type)
18 {
19 	if (WARN_ON(!chan))
20 		return;
21 
22 	chandef->chan = chan;
23 	chandef->center_freq2 = 0;
24 
25 	switch (chan_type) {
26 	case NL80211_CHAN_NO_HT:
27 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
28 		chandef->center_freq1 = chan->center_freq;
29 		break;
30 	case NL80211_CHAN_HT20:
31 		chandef->width = NL80211_CHAN_WIDTH_20;
32 		chandef->center_freq1 = chan->center_freq;
33 		break;
34 	case NL80211_CHAN_HT40PLUS:
35 		chandef->width = NL80211_CHAN_WIDTH_40;
36 		chandef->center_freq1 = chan->center_freq + 10;
37 		break;
38 	case NL80211_CHAN_HT40MINUS:
39 		chandef->width = NL80211_CHAN_WIDTH_40;
40 		chandef->center_freq1 = chan->center_freq - 10;
41 		break;
42 	default:
43 		WARN_ON(1);
44 	}
45 }
46 EXPORT_SYMBOL(cfg80211_chandef_create);
47 
48 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
49 {
50 	u32 control_freq;
51 
52 	if (!chandef->chan)
53 		return false;
54 
55 	control_freq = chandef->chan->center_freq;
56 
57 	switch (chandef->width) {
58 	case NL80211_CHAN_WIDTH_5:
59 	case NL80211_CHAN_WIDTH_10:
60 	case NL80211_CHAN_WIDTH_20:
61 	case NL80211_CHAN_WIDTH_20_NOHT:
62 		if (chandef->center_freq1 != control_freq)
63 			return false;
64 		if (chandef->center_freq2)
65 			return false;
66 		break;
67 	case NL80211_CHAN_WIDTH_40:
68 		if (chandef->center_freq1 != control_freq + 10 &&
69 		    chandef->center_freq1 != control_freq - 10)
70 			return false;
71 		if (chandef->center_freq2)
72 			return false;
73 		break;
74 	case NL80211_CHAN_WIDTH_80P80:
75 		if (chandef->center_freq1 != control_freq + 30 &&
76 		    chandef->center_freq1 != control_freq + 10 &&
77 		    chandef->center_freq1 != control_freq - 10 &&
78 		    chandef->center_freq1 != control_freq - 30)
79 			return false;
80 		if (!chandef->center_freq2)
81 			return false;
82 		/* adjacent is not allowed -- that's a 160 MHz channel */
83 		if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
84 		    chandef->center_freq2 - chandef->center_freq1 == 80)
85 			return false;
86 		break;
87 	case NL80211_CHAN_WIDTH_80:
88 		if (chandef->center_freq1 != control_freq + 30 &&
89 		    chandef->center_freq1 != control_freq + 10 &&
90 		    chandef->center_freq1 != control_freq - 10 &&
91 		    chandef->center_freq1 != control_freq - 30)
92 			return false;
93 		if (chandef->center_freq2)
94 			return false;
95 		break;
96 	case NL80211_CHAN_WIDTH_160:
97 		if (chandef->center_freq1 != control_freq + 70 &&
98 		    chandef->center_freq1 != control_freq + 50 &&
99 		    chandef->center_freq1 != control_freq + 30 &&
100 		    chandef->center_freq1 != control_freq + 10 &&
101 		    chandef->center_freq1 != control_freq - 10 &&
102 		    chandef->center_freq1 != control_freq - 30 &&
103 		    chandef->center_freq1 != control_freq - 50 &&
104 		    chandef->center_freq1 != control_freq - 70)
105 			return false;
106 		if (chandef->center_freq2)
107 			return false;
108 		break;
109 	default:
110 		return false;
111 	}
112 
113 	return true;
114 }
115 EXPORT_SYMBOL(cfg80211_chandef_valid);
116 
117 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
118 				  u32 *pri40, u32 *pri80)
119 {
120 	int tmp;
121 
122 	switch (c->width) {
123 	case NL80211_CHAN_WIDTH_40:
124 		*pri40 = c->center_freq1;
125 		*pri80 = 0;
126 		break;
127 	case NL80211_CHAN_WIDTH_80:
128 	case NL80211_CHAN_WIDTH_80P80:
129 		*pri80 = c->center_freq1;
130 		/* n_P20 */
131 		tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
132 		/* n_P40 */
133 		tmp /= 2;
134 		/* freq_P40 */
135 		*pri40 = c->center_freq1 - 20 + 40 * tmp;
136 		break;
137 	case NL80211_CHAN_WIDTH_160:
138 		/* n_P20 */
139 		tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
140 		/* n_P40 */
141 		tmp /= 2;
142 		/* freq_P40 */
143 		*pri40 = c->center_freq1 - 60 + 40 * tmp;
144 		/* n_P80 */
145 		tmp /= 2;
146 		*pri80 = c->center_freq1 - 40 + 80 * tmp;
147 		break;
148 	default:
149 		WARN_ON_ONCE(1);
150 	}
151 }
152 
153 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
154 {
155 	int width;
156 
157 	switch (c->width) {
158 	case NL80211_CHAN_WIDTH_5:
159 		width = 5;
160 		break;
161 	case NL80211_CHAN_WIDTH_10:
162 		width = 10;
163 		break;
164 	case NL80211_CHAN_WIDTH_20:
165 	case NL80211_CHAN_WIDTH_20_NOHT:
166 		width = 20;
167 		break;
168 	case NL80211_CHAN_WIDTH_40:
169 		width = 40;
170 		break;
171 	case NL80211_CHAN_WIDTH_80P80:
172 	case NL80211_CHAN_WIDTH_80:
173 		width = 80;
174 		break;
175 	case NL80211_CHAN_WIDTH_160:
176 		width = 160;
177 		break;
178 	default:
179 		WARN_ON_ONCE(1);
180 		return -1;
181 	}
182 	return width;
183 }
184 
185 const struct cfg80211_chan_def *
186 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
187 			    const struct cfg80211_chan_def *c2)
188 {
189 	u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
190 
191 	/* If they are identical, return */
192 	if (cfg80211_chandef_identical(c1, c2))
193 		return c1;
194 
195 	/* otherwise, must have same control channel */
196 	if (c1->chan != c2->chan)
197 		return NULL;
198 
199 	/*
200 	 * If they have the same width, but aren't identical,
201 	 * then they can't be compatible.
202 	 */
203 	if (c1->width == c2->width)
204 		return NULL;
205 
206 	/*
207 	 * can't be compatible if one of them is 5 or 10 MHz,
208 	 * but they don't have the same width.
209 	 */
210 	if (c1->width == NL80211_CHAN_WIDTH_5 ||
211 	    c1->width == NL80211_CHAN_WIDTH_10 ||
212 	    c2->width == NL80211_CHAN_WIDTH_5 ||
213 	    c2->width == NL80211_CHAN_WIDTH_10)
214 		return NULL;
215 
216 	if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
217 	    c1->width == NL80211_CHAN_WIDTH_20)
218 		return c2;
219 
220 	if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
221 	    c2->width == NL80211_CHAN_WIDTH_20)
222 		return c1;
223 
224 	chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
225 	chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
226 
227 	if (c1_pri40 != c2_pri40)
228 		return NULL;
229 
230 	WARN_ON(!c1_pri80 && !c2_pri80);
231 	if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
232 		return NULL;
233 
234 	if (c1->width > c2->width)
235 		return c1;
236 	return c2;
237 }
238 EXPORT_SYMBOL(cfg80211_chandef_compatible);
239 
240 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
241 					 u32 bandwidth,
242 					 enum nl80211_dfs_state dfs_state)
243 {
244 	struct ieee80211_channel *c;
245 	u32 freq;
246 
247 	for (freq = center_freq - bandwidth/2 + 10;
248 	     freq <= center_freq + bandwidth/2 - 10;
249 	     freq += 20) {
250 		c = ieee80211_get_channel(wiphy, freq);
251 		if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
252 			continue;
253 
254 		c->dfs_state = dfs_state;
255 		c->dfs_state_entered = jiffies;
256 	}
257 }
258 
259 void cfg80211_set_dfs_state(struct wiphy *wiphy,
260 			    const struct cfg80211_chan_def *chandef,
261 			    enum nl80211_dfs_state dfs_state)
262 {
263 	int width;
264 
265 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
266 		return;
267 
268 	width = cfg80211_chandef_get_width(chandef);
269 	if (width < 0)
270 		return;
271 
272 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
273 				     width, dfs_state);
274 
275 	if (!chandef->center_freq2)
276 		return;
277 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
278 				     width, dfs_state);
279 }
280 
281 static u32 cfg80211_get_start_freq(u32 center_freq,
282 				   u32 bandwidth)
283 {
284 	u32 start_freq;
285 
286 	if (bandwidth <= 20)
287 		start_freq = center_freq;
288 	else
289 		start_freq = center_freq - bandwidth/2 + 10;
290 
291 	return start_freq;
292 }
293 
294 static u32 cfg80211_get_end_freq(u32 center_freq,
295 				 u32 bandwidth)
296 {
297 	u32 end_freq;
298 
299 	if (bandwidth <= 20)
300 		end_freq = center_freq;
301 	else
302 		end_freq = center_freq + bandwidth/2 - 10;
303 
304 	return end_freq;
305 }
306 
307 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
308 					    u32 center_freq,
309 					    u32 bandwidth)
310 {
311 	struct ieee80211_channel *c;
312 	u32 freq, start_freq, end_freq;
313 
314 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
315 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
316 
317 	for (freq = start_freq; freq <= end_freq; freq += 20) {
318 		c = ieee80211_get_channel(wiphy, freq);
319 		if (!c)
320 			return -EINVAL;
321 
322 		if (c->flags & IEEE80211_CHAN_RADAR)
323 			return 1;
324 	}
325 	return 0;
326 }
327 
328 
329 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
330 				  const struct cfg80211_chan_def *chandef,
331 				  enum nl80211_iftype iftype)
332 {
333 	int width;
334 	int ret;
335 
336 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
337 		return -EINVAL;
338 
339 	switch (iftype) {
340 	case NL80211_IFTYPE_ADHOC:
341 	case NL80211_IFTYPE_AP:
342 	case NL80211_IFTYPE_P2P_GO:
343 	case NL80211_IFTYPE_MESH_POINT:
344 		width = cfg80211_chandef_get_width(chandef);
345 		if (width < 0)
346 			return -EINVAL;
347 
348 		ret = cfg80211_get_chans_dfs_required(wiphy,
349 						      chandef->center_freq1,
350 						      width);
351 		if (ret < 0)
352 			return ret;
353 		else if (ret > 0)
354 			return BIT(chandef->width);
355 
356 		if (!chandef->center_freq2)
357 			return 0;
358 
359 		ret = cfg80211_get_chans_dfs_required(wiphy,
360 						      chandef->center_freq2,
361 						      width);
362 		if (ret < 0)
363 			return ret;
364 		else if (ret > 0)
365 			return BIT(chandef->width);
366 
367 		break;
368 	case NL80211_IFTYPE_STATION:
369 	case NL80211_IFTYPE_OCB:
370 	case NL80211_IFTYPE_P2P_CLIENT:
371 	case NL80211_IFTYPE_MONITOR:
372 	case NL80211_IFTYPE_AP_VLAN:
373 	case NL80211_IFTYPE_WDS:
374 	case NL80211_IFTYPE_P2P_DEVICE:
375 	case NL80211_IFTYPE_NAN:
376 		break;
377 	case NL80211_IFTYPE_UNSPECIFIED:
378 	case NUM_NL80211_IFTYPES:
379 		WARN_ON(1);
380 	}
381 
382 	return 0;
383 }
384 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
385 
386 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
387 					 u32 center_freq,
388 					 u32 bandwidth)
389 {
390 	struct ieee80211_channel *c;
391 	u32 freq, start_freq, end_freq;
392 	int count = 0;
393 
394 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
395 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
396 
397 	/*
398 	 * Check entire range of channels for the bandwidth.
399 	 * Check all channels are DFS channels (DFS_USABLE or
400 	 * DFS_AVAILABLE). Return number of usable channels
401 	 * (require CAC). Allow DFS and non-DFS channel mix.
402 	 */
403 	for (freq = start_freq; freq <= end_freq; freq += 20) {
404 		c = ieee80211_get_channel(wiphy, freq);
405 		if (!c)
406 			return -EINVAL;
407 
408 		if (c->flags & IEEE80211_CHAN_DISABLED)
409 			return -EINVAL;
410 
411 		if (c->flags & IEEE80211_CHAN_RADAR) {
412 			if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
413 				return -EINVAL;
414 
415 			if (c->dfs_state == NL80211_DFS_USABLE)
416 				count++;
417 		}
418 	}
419 
420 	return count;
421 }
422 
423 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
424 				 const struct cfg80211_chan_def *chandef)
425 {
426 	int width;
427 	int r1, r2 = 0;
428 
429 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
430 		return false;
431 
432 	width = cfg80211_chandef_get_width(chandef);
433 	if (width < 0)
434 		return false;
435 
436 	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
437 					  width);
438 
439 	if (r1 < 0)
440 		return false;
441 
442 	switch (chandef->width) {
443 	case NL80211_CHAN_WIDTH_80P80:
444 		WARN_ON(!chandef->center_freq2);
445 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
446 						   chandef->center_freq2,
447 						   width);
448 		if (r2 < 0)
449 			return false;
450 		break;
451 	default:
452 		WARN_ON(chandef->center_freq2);
453 		break;
454 	}
455 
456 	return (r1 + r2 > 0);
457 }
458 
459 /*
460  * Checks if center frequency of chan falls with in the bandwidth
461  * range of chandef.
462  */
463 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
464 			  struct ieee80211_channel *chan)
465 {
466 	int width;
467 	u32 freq;
468 
469 	if (chandef->chan->center_freq == chan->center_freq)
470 		return true;
471 
472 	width = cfg80211_chandef_get_width(chandef);
473 	if (width <= 20)
474 		return false;
475 
476 	for (freq = chandef->center_freq1 - width / 2 + 10;
477 	     freq <= chandef->center_freq1 + width / 2 - 10; freq += 20) {
478 		if (chan->center_freq == freq)
479 			return true;
480 	}
481 
482 	if (!chandef->center_freq2)
483 		return false;
484 
485 	for (freq = chandef->center_freq2 - width / 2 + 10;
486 	     freq <= chandef->center_freq2 + width / 2 - 10; freq += 20) {
487 		if (chan->center_freq == freq)
488 			return true;
489 	}
490 
491 	return false;
492 }
493 
494 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
495 {
496 	bool active = false;
497 
498 	ASSERT_WDEV_LOCK(wdev);
499 
500 	if (!wdev->chandef.chan)
501 		return false;
502 
503 	switch (wdev->iftype) {
504 	case NL80211_IFTYPE_AP:
505 	case NL80211_IFTYPE_P2P_GO:
506 		active = wdev->beacon_interval != 0;
507 		break;
508 	case NL80211_IFTYPE_ADHOC:
509 		active = wdev->ssid_len != 0;
510 		break;
511 	case NL80211_IFTYPE_MESH_POINT:
512 		active = wdev->mesh_id_len != 0;
513 		break;
514 	case NL80211_IFTYPE_STATION:
515 	case NL80211_IFTYPE_OCB:
516 	case NL80211_IFTYPE_P2P_CLIENT:
517 	case NL80211_IFTYPE_MONITOR:
518 	case NL80211_IFTYPE_AP_VLAN:
519 	case NL80211_IFTYPE_WDS:
520 	case NL80211_IFTYPE_P2P_DEVICE:
521 	/* Can NAN type be considered as beaconing interface? */
522 	case NL80211_IFTYPE_NAN:
523 		break;
524 	case NL80211_IFTYPE_UNSPECIFIED:
525 	case NUM_NL80211_IFTYPES:
526 		WARN_ON(1);
527 	}
528 
529 	return active;
530 }
531 
532 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
533 					struct ieee80211_channel *chan)
534 {
535 	struct wireless_dev *wdev;
536 
537 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
538 		wdev_lock(wdev);
539 		if (!cfg80211_beaconing_iface_active(wdev)) {
540 			wdev_unlock(wdev);
541 			continue;
542 		}
543 
544 		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
545 			wdev_unlock(wdev);
546 			return true;
547 		}
548 		wdev_unlock(wdev);
549 	}
550 
551 	return false;
552 }
553 
554 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
555 				  struct ieee80211_channel *chan)
556 {
557 	struct cfg80211_registered_device *rdev;
558 
559 	ASSERT_RTNL();
560 
561 	if (!(chan->flags & IEEE80211_CHAN_RADAR))
562 		return false;
563 
564 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
565 		if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
566 			continue;
567 
568 		if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
569 			return true;
570 	}
571 
572 	return false;
573 }
574 
575 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
576 					     u32 center_freq,
577 					     u32 bandwidth)
578 {
579 	struct ieee80211_channel *c;
580 	u32 freq, start_freq, end_freq;
581 
582 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
583 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
584 
585 	/*
586 	 * Check entire range of channels for the bandwidth.
587 	 * If any channel in between is disabled or has not
588 	 * had gone through CAC return false
589 	 */
590 	for (freq = start_freq; freq <= end_freq; freq += 20) {
591 		c = ieee80211_get_channel(wiphy, freq);
592 		if (!c)
593 			return false;
594 
595 		if (c->flags & IEEE80211_CHAN_DISABLED)
596 			return false;
597 
598 		if ((c->flags & IEEE80211_CHAN_RADAR)  &&
599 		    (c->dfs_state != NL80211_DFS_AVAILABLE))
600 			return false;
601 	}
602 
603 	return true;
604 }
605 
606 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
607 				const struct cfg80211_chan_def *chandef)
608 {
609 	int width;
610 	int r;
611 
612 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
613 		return false;
614 
615 	width = cfg80211_chandef_get_width(chandef);
616 	if (width < 0)
617 		return false;
618 
619 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
620 					     width);
621 
622 	/* If any of channels unavailable for cf1 just return */
623 	if (!r)
624 		return r;
625 
626 	switch (chandef->width) {
627 	case NL80211_CHAN_WIDTH_80P80:
628 		WARN_ON(!chandef->center_freq2);
629 		r = cfg80211_get_chans_dfs_available(wiphy,
630 						     chandef->center_freq2,
631 						     width);
632 		break;
633 	default:
634 		WARN_ON(chandef->center_freq2);
635 		break;
636 	}
637 
638 	return r;
639 }
640 
641 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
642 						    u32 center_freq,
643 						    u32 bandwidth)
644 {
645 	struct ieee80211_channel *c;
646 	u32 start_freq, end_freq, freq;
647 	unsigned int dfs_cac_ms = 0;
648 
649 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
650 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
651 
652 	for (freq = start_freq; freq <= end_freq; freq += 20) {
653 		c = ieee80211_get_channel(wiphy, freq);
654 		if (!c)
655 			return 0;
656 
657 		if (c->flags & IEEE80211_CHAN_DISABLED)
658 			return 0;
659 
660 		if (!(c->flags & IEEE80211_CHAN_RADAR))
661 			continue;
662 
663 		if (c->dfs_cac_ms > dfs_cac_ms)
664 			dfs_cac_ms = c->dfs_cac_ms;
665 	}
666 
667 	return dfs_cac_ms;
668 }
669 
670 unsigned int
671 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
672 			      const struct cfg80211_chan_def *chandef)
673 {
674 	int width;
675 	unsigned int t1 = 0, t2 = 0;
676 
677 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
678 		return 0;
679 
680 	width = cfg80211_chandef_get_width(chandef);
681 	if (width < 0)
682 		return 0;
683 
684 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
685 					     chandef->center_freq1,
686 					     width);
687 
688 	if (!chandef->center_freq2)
689 		return t1;
690 
691 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
692 					     chandef->center_freq2,
693 					     width);
694 
695 	return max(t1, t2);
696 }
697 
698 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
699 					u32 center_freq, u32 bandwidth,
700 					u32 prohibited_flags)
701 {
702 	struct ieee80211_channel *c;
703 	u32 freq, start_freq, end_freq;
704 
705 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
706 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
707 
708 	for (freq = start_freq; freq <= end_freq; freq += 20) {
709 		c = ieee80211_get_channel(wiphy, freq);
710 		if (!c || c->flags & prohibited_flags)
711 			return false;
712 	}
713 
714 	return true;
715 }
716 
717 bool cfg80211_chandef_usable(struct wiphy *wiphy,
718 			     const struct cfg80211_chan_def *chandef,
719 			     u32 prohibited_flags)
720 {
721 	struct ieee80211_sta_ht_cap *ht_cap;
722 	struct ieee80211_sta_vht_cap *vht_cap;
723 	u32 width, control_freq, cap;
724 
725 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
726 		return false;
727 
728 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
729 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
730 
731 	control_freq = chandef->chan->center_freq;
732 
733 	switch (chandef->width) {
734 	case NL80211_CHAN_WIDTH_5:
735 		width = 5;
736 		break;
737 	case NL80211_CHAN_WIDTH_10:
738 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
739 		width = 10;
740 		break;
741 	case NL80211_CHAN_WIDTH_20:
742 		if (!ht_cap->ht_supported)
743 			return false;
744 	case NL80211_CHAN_WIDTH_20_NOHT:
745 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
746 		width = 20;
747 		break;
748 	case NL80211_CHAN_WIDTH_40:
749 		width = 40;
750 		if (!ht_cap->ht_supported)
751 			return false;
752 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
753 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
754 			return false;
755 		if (chandef->center_freq1 < control_freq &&
756 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
757 			return false;
758 		if (chandef->center_freq1 > control_freq &&
759 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
760 			return false;
761 		break;
762 	case NL80211_CHAN_WIDTH_80P80:
763 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
764 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
765 			return false;
766 	case NL80211_CHAN_WIDTH_80:
767 		if (!vht_cap->vht_supported)
768 			return false;
769 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
770 		width = 80;
771 		break;
772 	case NL80211_CHAN_WIDTH_160:
773 		if (!vht_cap->vht_supported)
774 			return false;
775 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
776 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
777 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
778 			return false;
779 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
780 		width = 160;
781 		break;
782 	default:
783 		WARN_ON_ONCE(1);
784 		return false;
785 	}
786 
787 	/*
788 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
789 	 *	 allowed by the driver, or only certain combinations?
790 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
791 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
792 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
793 	 *	 no way to cover 80+80 MHz or more complex restrictions.
794 	 *	 Note that such restrictions also need to be advertised to
795 	 *	 userspace, for example for P2P channel selection.
796 	 */
797 
798 	if (width > 20)
799 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
800 
801 	/* 5 and 10 MHz are only defined for the OFDM PHY */
802 	if (width < 20)
803 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
804 
805 
806 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
807 					 width, prohibited_flags))
808 		return false;
809 
810 	if (!chandef->center_freq2)
811 		return true;
812 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
813 					   width, prohibited_flags);
814 }
815 EXPORT_SYMBOL(cfg80211_chandef_usable);
816 
817 /*
818  * Check if the channel can be used under permissive conditions mandated by
819  * some regulatory bodies, i.e., the channel is marked with
820  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
821  * associated to an AP on the same channel or on the same UNII band
822  * (assuming that the AP is an authorized master).
823  * In addition allow operation on a channel on which indoor operation is
824  * allowed, iff we are currently operating in an indoor environment.
825  */
826 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
827 					enum nl80211_iftype iftype,
828 					struct ieee80211_channel *chan)
829 {
830 	struct wireless_dev *wdev;
831 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
832 
833 	ASSERT_RTNL();
834 
835 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
836 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
837 		return false;
838 
839 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
840 	if (iftype != NL80211_IFTYPE_P2P_GO &&
841 	    iftype != NL80211_IFTYPE_STATION &&
842 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
843 		return false;
844 
845 	if (regulatory_indoor_allowed() &&
846 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
847 		return true;
848 
849 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
850 		return false;
851 
852 	/*
853 	 * Generally, it is possible to rely on another device/driver to allow
854 	 * the IR concurrent relaxation, however, since the device can further
855 	 * enforce the relaxation (by doing a similar verifications as this),
856 	 * and thus fail the GO instantiation, consider only the interfaces of
857 	 * the current registered device.
858 	 */
859 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
860 		struct ieee80211_channel *other_chan = NULL;
861 		int r1, r2;
862 
863 		wdev_lock(wdev);
864 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
865 		    wdev->current_bss)
866 			other_chan = wdev->current_bss->pub.channel;
867 
868 		/*
869 		 * If a GO already operates on the same GO_CONCURRENT channel,
870 		 * this one (maybe the same one) can beacon as well. We allow
871 		 * the operation even if the station we relied on with
872 		 * GO_CONCURRENT is disconnected now. But then we must make sure
873 		 * we're not outdoor on an indoor-only channel.
874 		 */
875 		if (iftype == NL80211_IFTYPE_P2P_GO &&
876 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
877 		    wdev->beacon_interval &&
878 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
879 			other_chan = wdev->chandef.chan;
880 		wdev_unlock(wdev);
881 
882 		if (!other_chan)
883 			continue;
884 
885 		if (chan == other_chan)
886 			return true;
887 
888 		if (chan->band != NL80211_BAND_5GHZ)
889 			continue;
890 
891 		r1 = cfg80211_get_unii(chan->center_freq);
892 		r2 = cfg80211_get_unii(other_chan->center_freq);
893 
894 		if (r1 != -EINVAL && r1 == r2) {
895 			/*
896 			 * At some locations channels 149-165 are considered a
897 			 * bundle, but at other locations, e.g., Indonesia,
898 			 * channels 149-161 are considered a bundle while
899 			 * channel 165 is left out and considered to be in a
900 			 * different bundle. Thus, in case that there is a
901 			 * station interface connected to an AP on channel 165,
902 			 * it is assumed that channels 149-161 are allowed for
903 			 * GO operations. However, having a station interface
904 			 * connected to an AP on channels 149-161, does not
905 			 * allow GO operation on channel 165.
906 			 */
907 			if (chan->center_freq == 5825 &&
908 			    other_chan->center_freq != 5825)
909 				continue;
910 			return true;
911 		}
912 	}
913 
914 	return false;
915 }
916 
917 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
918 				     struct cfg80211_chan_def *chandef,
919 				     enum nl80211_iftype iftype,
920 				     bool check_no_ir)
921 {
922 	bool res;
923 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
924 			       IEEE80211_CHAN_RADAR;
925 
926 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
927 
928 	if (check_no_ir)
929 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
930 
931 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
932 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
933 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
934 		prohibited_flags = IEEE80211_CHAN_DISABLED;
935 	}
936 
937 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
938 
939 	trace_cfg80211_return_bool(res);
940 	return res;
941 }
942 
943 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
944 			     struct cfg80211_chan_def *chandef,
945 			     enum nl80211_iftype iftype)
946 {
947 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
948 }
949 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
950 
951 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
952 				   struct cfg80211_chan_def *chandef,
953 				   enum nl80211_iftype iftype)
954 {
955 	bool check_no_ir;
956 
957 	ASSERT_RTNL();
958 
959 	/*
960 	 * Under certain conditions suggested by some regulatory bodies a
961 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
962 	 * only if such relaxations are not enabled and the conditions are not
963 	 * met.
964 	 */
965 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
966 						   chandef->chan);
967 
968 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
969 }
970 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
971 
972 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
973 				 struct cfg80211_chan_def *chandef)
974 {
975 	if (!rdev->ops->set_monitor_channel)
976 		return -EOPNOTSUPP;
977 	if (!cfg80211_has_monitors_only(rdev))
978 		return -EBUSY;
979 
980 	return rdev_set_monitor_channel(rdev, chandef);
981 }
982 
983 void
984 cfg80211_get_chan_state(struct wireless_dev *wdev,
985 		        struct ieee80211_channel **chan,
986 		        enum cfg80211_chan_mode *chanmode,
987 		        u8 *radar_detect)
988 {
989 	int ret;
990 
991 	*chan = NULL;
992 	*chanmode = CHAN_MODE_UNDEFINED;
993 
994 	ASSERT_WDEV_LOCK(wdev);
995 
996 	if (wdev->netdev && !netif_running(wdev->netdev))
997 		return;
998 
999 	switch (wdev->iftype) {
1000 	case NL80211_IFTYPE_ADHOC:
1001 		if (wdev->current_bss) {
1002 			*chan = wdev->current_bss->pub.channel;
1003 			*chanmode = (wdev->ibss_fixed &&
1004 				     !wdev->ibss_dfs_possible)
1005 				  ? CHAN_MODE_SHARED
1006 				  : CHAN_MODE_EXCLUSIVE;
1007 
1008 			/* consider worst-case - IBSS can try to return to the
1009 			 * original user-specified channel as creator */
1010 			if (wdev->ibss_dfs_possible)
1011 				*radar_detect |= BIT(wdev->chandef.width);
1012 			return;
1013 		}
1014 		break;
1015 	case NL80211_IFTYPE_STATION:
1016 	case NL80211_IFTYPE_P2P_CLIENT:
1017 		if (wdev->current_bss) {
1018 			*chan = wdev->current_bss->pub.channel;
1019 			*chanmode = CHAN_MODE_SHARED;
1020 			return;
1021 		}
1022 		break;
1023 	case NL80211_IFTYPE_AP:
1024 	case NL80211_IFTYPE_P2P_GO:
1025 		if (wdev->cac_started) {
1026 			*chan = wdev->chandef.chan;
1027 			*chanmode = CHAN_MODE_SHARED;
1028 			*radar_detect |= BIT(wdev->chandef.width);
1029 		} else if (wdev->beacon_interval) {
1030 			*chan = wdev->chandef.chan;
1031 			*chanmode = CHAN_MODE_SHARED;
1032 
1033 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1034 							    &wdev->chandef,
1035 							    wdev->iftype);
1036 			WARN_ON(ret < 0);
1037 			if (ret > 0)
1038 				*radar_detect |= BIT(wdev->chandef.width);
1039 		}
1040 		return;
1041 	case NL80211_IFTYPE_MESH_POINT:
1042 		if (wdev->mesh_id_len) {
1043 			*chan = wdev->chandef.chan;
1044 			*chanmode = CHAN_MODE_SHARED;
1045 
1046 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1047 							    &wdev->chandef,
1048 							    wdev->iftype);
1049 			WARN_ON(ret < 0);
1050 			if (ret > 0)
1051 				*radar_detect |= BIT(wdev->chandef.width);
1052 		}
1053 		return;
1054 	case NL80211_IFTYPE_OCB:
1055 		if (wdev->chandef.chan) {
1056 			*chan = wdev->chandef.chan;
1057 			*chanmode = CHAN_MODE_SHARED;
1058 			return;
1059 		}
1060 		break;
1061 	case NL80211_IFTYPE_MONITOR:
1062 	case NL80211_IFTYPE_AP_VLAN:
1063 	case NL80211_IFTYPE_WDS:
1064 	case NL80211_IFTYPE_P2P_DEVICE:
1065 	case NL80211_IFTYPE_NAN:
1066 		/* these interface types don't really have a channel */
1067 		return;
1068 	case NL80211_IFTYPE_UNSPECIFIED:
1069 	case NUM_NL80211_IFTYPES:
1070 		WARN_ON(1);
1071 	}
1072 }
1073