xref: /linux/net/wireless/chan.c (revision e60e1ee60630cafef5e430c2ae364877e061d980)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This file contains helper code to handle channel
4  * settings and keeping track of what is possible at
5  * any point in time.
6  *
7  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
8  * Copyright 2013-2014  Intel Mobile Communications GmbH
9  */
10 
11 #include <linux/export.h>
12 #include <net/cfg80211.h>
13 #include "core.h"
14 #include "rdev-ops.h"
15 
16 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
17 			     struct ieee80211_channel *chan,
18 			     enum nl80211_channel_type chan_type)
19 {
20 	if (WARN_ON(!chan))
21 		return;
22 
23 	chandef->chan = chan;
24 	chandef->center_freq2 = 0;
25 
26 	switch (chan_type) {
27 	case NL80211_CHAN_NO_HT:
28 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
29 		chandef->center_freq1 = chan->center_freq;
30 		break;
31 	case NL80211_CHAN_HT20:
32 		chandef->width = NL80211_CHAN_WIDTH_20;
33 		chandef->center_freq1 = chan->center_freq;
34 		break;
35 	case NL80211_CHAN_HT40PLUS:
36 		chandef->width = NL80211_CHAN_WIDTH_40;
37 		chandef->center_freq1 = chan->center_freq + 10;
38 		break;
39 	case NL80211_CHAN_HT40MINUS:
40 		chandef->width = NL80211_CHAN_WIDTH_40;
41 		chandef->center_freq1 = chan->center_freq - 10;
42 		break;
43 	default:
44 		WARN_ON(1);
45 	}
46 }
47 EXPORT_SYMBOL(cfg80211_chandef_create);
48 
49 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
50 {
51 	u32 control_freq;
52 
53 	if (!chandef->chan)
54 		return false;
55 
56 	control_freq = chandef->chan->center_freq;
57 
58 	switch (chandef->width) {
59 	case NL80211_CHAN_WIDTH_5:
60 	case NL80211_CHAN_WIDTH_10:
61 	case NL80211_CHAN_WIDTH_20:
62 	case NL80211_CHAN_WIDTH_20_NOHT:
63 		if (chandef->center_freq1 != control_freq)
64 			return false;
65 		if (chandef->center_freq2)
66 			return false;
67 		break;
68 	case NL80211_CHAN_WIDTH_40:
69 		if (chandef->center_freq1 != control_freq + 10 &&
70 		    chandef->center_freq1 != control_freq - 10)
71 			return false;
72 		if (chandef->center_freq2)
73 			return false;
74 		break;
75 	case NL80211_CHAN_WIDTH_80P80:
76 		if (chandef->center_freq1 != control_freq + 30 &&
77 		    chandef->center_freq1 != control_freq + 10 &&
78 		    chandef->center_freq1 != control_freq - 10 &&
79 		    chandef->center_freq1 != control_freq - 30)
80 			return false;
81 		if (!chandef->center_freq2)
82 			return false;
83 		/* adjacent is not allowed -- that's a 160 MHz channel */
84 		if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
85 		    chandef->center_freq2 - chandef->center_freq1 == 80)
86 			return false;
87 		break;
88 	case NL80211_CHAN_WIDTH_80:
89 		if (chandef->center_freq1 != control_freq + 30 &&
90 		    chandef->center_freq1 != control_freq + 10 &&
91 		    chandef->center_freq1 != control_freq - 10 &&
92 		    chandef->center_freq1 != control_freq - 30)
93 			return false;
94 		if (chandef->center_freq2)
95 			return false;
96 		break;
97 	case NL80211_CHAN_WIDTH_160:
98 		if (chandef->center_freq1 != control_freq + 70 &&
99 		    chandef->center_freq1 != control_freq + 50 &&
100 		    chandef->center_freq1 != control_freq + 30 &&
101 		    chandef->center_freq1 != control_freq + 10 &&
102 		    chandef->center_freq1 != control_freq - 10 &&
103 		    chandef->center_freq1 != control_freq - 30 &&
104 		    chandef->center_freq1 != control_freq - 50 &&
105 		    chandef->center_freq1 != control_freq - 70)
106 			return false;
107 		if (chandef->center_freq2)
108 			return false;
109 		break;
110 	default:
111 		return false;
112 	}
113 
114 	return true;
115 }
116 EXPORT_SYMBOL(cfg80211_chandef_valid);
117 
118 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
119 				  u32 *pri40, u32 *pri80)
120 {
121 	int tmp;
122 
123 	switch (c->width) {
124 	case NL80211_CHAN_WIDTH_40:
125 		*pri40 = c->center_freq1;
126 		*pri80 = 0;
127 		break;
128 	case NL80211_CHAN_WIDTH_80:
129 	case NL80211_CHAN_WIDTH_80P80:
130 		*pri80 = c->center_freq1;
131 		/* n_P20 */
132 		tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
133 		/* n_P40 */
134 		tmp /= 2;
135 		/* freq_P40 */
136 		*pri40 = c->center_freq1 - 20 + 40 * tmp;
137 		break;
138 	case NL80211_CHAN_WIDTH_160:
139 		/* n_P20 */
140 		tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
141 		/* n_P40 */
142 		tmp /= 2;
143 		/* freq_P40 */
144 		*pri40 = c->center_freq1 - 60 + 40 * tmp;
145 		/* n_P80 */
146 		tmp /= 2;
147 		*pri80 = c->center_freq1 - 40 + 80 * tmp;
148 		break;
149 	default:
150 		WARN_ON_ONCE(1);
151 	}
152 }
153 
154 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
155 {
156 	int width;
157 
158 	switch (c->width) {
159 	case NL80211_CHAN_WIDTH_5:
160 		width = 5;
161 		break;
162 	case NL80211_CHAN_WIDTH_10:
163 		width = 10;
164 		break;
165 	case NL80211_CHAN_WIDTH_20:
166 	case NL80211_CHAN_WIDTH_20_NOHT:
167 		width = 20;
168 		break;
169 	case NL80211_CHAN_WIDTH_40:
170 		width = 40;
171 		break;
172 	case NL80211_CHAN_WIDTH_80P80:
173 	case NL80211_CHAN_WIDTH_80:
174 		width = 80;
175 		break;
176 	case NL80211_CHAN_WIDTH_160:
177 		width = 160;
178 		break;
179 	default:
180 		WARN_ON_ONCE(1);
181 		return -1;
182 	}
183 	return width;
184 }
185 
186 const struct cfg80211_chan_def *
187 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
188 			    const struct cfg80211_chan_def *c2)
189 {
190 	u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
191 
192 	/* If they are identical, return */
193 	if (cfg80211_chandef_identical(c1, c2))
194 		return c1;
195 
196 	/* otherwise, must have same control channel */
197 	if (c1->chan != c2->chan)
198 		return NULL;
199 
200 	/*
201 	 * If they have the same width, but aren't identical,
202 	 * then they can't be compatible.
203 	 */
204 	if (c1->width == c2->width)
205 		return NULL;
206 
207 	/*
208 	 * can't be compatible if one of them is 5 or 10 MHz,
209 	 * but they don't have the same width.
210 	 */
211 	if (c1->width == NL80211_CHAN_WIDTH_5 ||
212 	    c1->width == NL80211_CHAN_WIDTH_10 ||
213 	    c2->width == NL80211_CHAN_WIDTH_5 ||
214 	    c2->width == NL80211_CHAN_WIDTH_10)
215 		return NULL;
216 
217 	if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
218 	    c1->width == NL80211_CHAN_WIDTH_20)
219 		return c2;
220 
221 	if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
222 	    c2->width == NL80211_CHAN_WIDTH_20)
223 		return c1;
224 
225 	chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
226 	chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
227 
228 	if (c1_pri40 != c2_pri40)
229 		return NULL;
230 
231 	WARN_ON(!c1_pri80 && !c2_pri80);
232 	if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
233 		return NULL;
234 
235 	if (c1->width > c2->width)
236 		return c1;
237 	return c2;
238 }
239 EXPORT_SYMBOL(cfg80211_chandef_compatible);
240 
241 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
242 					 u32 bandwidth,
243 					 enum nl80211_dfs_state dfs_state)
244 {
245 	struct ieee80211_channel *c;
246 	u32 freq;
247 
248 	for (freq = center_freq - bandwidth/2 + 10;
249 	     freq <= center_freq + bandwidth/2 - 10;
250 	     freq += 20) {
251 		c = ieee80211_get_channel(wiphy, freq);
252 		if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
253 			continue;
254 
255 		c->dfs_state = dfs_state;
256 		c->dfs_state_entered = jiffies;
257 	}
258 }
259 
260 void cfg80211_set_dfs_state(struct wiphy *wiphy,
261 			    const struct cfg80211_chan_def *chandef,
262 			    enum nl80211_dfs_state dfs_state)
263 {
264 	int width;
265 
266 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
267 		return;
268 
269 	width = cfg80211_chandef_get_width(chandef);
270 	if (width < 0)
271 		return;
272 
273 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
274 				     width, dfs_state);
275 
276 	if (!chandef->center_freq2)
277 		return;
278 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
279 				     width, dfs_state);
280 }
281 
282 static u32 cfg80211_get_start_freq(u32 center_freq,
283 				   u32 bandwidth)
284 {
285 	u32 start_freq;
286 
287 	if (bandwidth <= 20)
288 		start_freq = center_freq;
289 	else
290 		start_freq = center_freq - bandwidth/2 + 10;
291 
292 	return start_freq;
293 }
294 
295 static u32 cfg80211_get_end_freq(u32 center_freq,
296 				 u32 bandwidth)
297 {
298 	u32 end_freq;
299 
300 	if (bandwidth <= 20)
301 		end_freq = center_freq;
302 	else
303 		end_freq = center_freq + bandwidth/2 - 10;
304 
305 	return end_freq;
306 }
307 
308 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
309 					    u32 center_freq,
310 					    u32 bandwidth)
311 {
312 	struct ieee80211_channel *c;
313 	u32 freq, start_freq, end_freq;
314 
315 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
316 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
317 
318 	for (freq = start_freq; freq <= end_freq; freq += 20) {
319 		c = ieee80211_get_channel(wiphy, freq);
320 		if (!c)
321 			return -EINVAL;
322 
323 		if (c->flags & IEEE80211_CHAN_RADAR)
324 			return 1;
325 	}
326 	return 0;
327 }
328 
329 
330 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
331 				  const struct cfg80211_chan_def *chandef,
332 				  enum nl80211_iftype iftype)
333 {
334 	int width;
335 	int ret;
336 
337 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
338 		return -EINVAL;
339 
340 	switch (iftype) {
341 	case NL80211_IFTYPE_ADHOC:
342 	case NL80211_IFTYPE_AP:
343 	case NL80211_IFTYPE_P2P_GO:
344 	case NL80211_IFTYPE_MESH_POINT:
345 		width = cfg80211_chandef_get_width(chandef);
346 		if (width < 0)
347 			return -EINVAL;
348 
349 		ret = cfg80211_get_chans_dfs_required(wiphy,
350 						      chandef->center_freq1,
351 						      width);
352 		if (ret < 0)
353 			return ret;
354 		else if (ret > 0)
355 			return BIT(chandef->width);
356 
357 		if (!chandef->center_freq2)
358 			return 0;
359 
360 		ret = cfg80211_get_chans_dfs_required(wiphy,
361 						      chandef->center_freq2,
362 						      width);
363 		if (ret < 0)
364 			return ret;
365 		else if (ret > 0)
366 			return BIT(chandef->width);
367 
368 		break;
369 	case NL80211_IFTYPE_STATION:
370 	case NL80211_IFTYPE_OCB:
371 	case NL80211_IFTYPE_P2P_CLIENT:
372 	case NL80211_IFTYPE_MONITOR:
373 	case NL80211_IFTYPE_AP_VLAN:
374 	case NL80211_IFTYPE_WDS:
375 	case NL80211_IFTYPE_P2P_DEVICE:
376 	case NL80211_IFTYPE_NAN:
377 		break;
378 	case NL80211_IFTYPE_UNSPECIFIED:
379 	case NUM_NL80211_IFTYPES:
380 		WARN_ON(1);
381 	}
382 
383 	return 0;
384 }
385 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
386 
387 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
388 					 u32 center_freq,
389 					 u32 bandwidth)
390 {
391 	struct ieee80211_channel *c;
392 	u32 freq, start_freq, end_freq;
393 	int count = 0;
394 
395 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
396 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
397 
398 	/*
399 	 * Check entire range of channels for the bandwidth.
400 	 * Check all channels are DFS channels (DFS_USABLE or
401 	 * DFS_AVAILABLE). Return number of usable channels
402 	 * (require CAC). Allow DFS and non-DFS channel mix.
403 	 */
404 	for (freq = start_freq; freq <= end_freq; freq += 20) {
405 		c = ieee80211_get_channel(wiphy, freq);
406 		if (!c)
407 			return -EINVAL;
408 
409 		if (c->flags & IEEE80211_CHAN_DISABLED)
410 			return -EINVAL;
411 
412 		if (c->flags & IEEE80211_CHAN_RADAR) {
413 			if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
414 				return -EINVAL;
415 
416 			if (c->dfs_state == NL80211_DFS_USABLE)
417 				count++;
418 		}
419 	}
420 
421 	return count;
422 }
423 
424 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
425 				 const struct cfg80211_chan_def *chandef)
426 {
427 	int width;
428 	int r1, r2 = 0;
429 
430 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
431 		return false;
432 
433 	width = cfg80211_chandef_get_width(chandef);
434 	if (width < 0)
435 		return false;
436 
437 	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
438 					  width);
439 
440 	if (r1 < 0)
441 		return false;
442 
443 	switch (chandef->width) {
444 	case NL80211_CHAN_WIDTH_80P80:
445 		WARN_ON(!chandef->center_freq2);
446 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
447 						   chandef->center_freq2,
448 						   width);
449 		if (r2 < 0)
450 			return false;
451 		break;
452 	default:
453 		WARN_ON(chandef->center_freq2);
454 		break;
455 	}
456 
457 	return (r1 + r2 > 0);
458 }
459 
460 /*
461  * Checks if center frequency of chan falls with in the bandwidth
462  * range of chandef.
463  */
464 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
465 			  struct ieee80211_channel *chan)
466 {
467 	int width;
468 	u32 freq;
469 
470 	if (chandef->chan->center_freq == chan->center_freq)
471 		return true;
472 
473 	width = cfg80211_chandef_get_width(chandef);
474 	if (width <= 20)
475 		return false;
476 
477 	for (freq = chandef->center_freq1 - width / 2 + 10;
478 	     freq <= chandef->center_freq1 + width / 2 - 10; freq += 20) {
479 		if (chan->center_freq == freq)
480 			return true;
481 	}
482 
483 	if (!chandef->center_freq2)
484 		return false;
485 
486 	for (freq = chandef->center_freq2 - width / 2 + 10;
487 	     freq <= chandef->center_freq2 + width / 2 - 10; freq += 20) {
488 		if (chan->center_freq == freq)
489 			return true;
490 	}
491 
492 	return false;
493 }
494 
495 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
496 {
497 	bool active = false;
498 
499 	ASSERT_WDEV_LOCK(wdev);
500 
501 	if (!wdev->chandef.chan)
502 		return false;
503 
504 	switch (wdev->iftype) {
505 	case NL80211_IFTYPE_AP:
506 	case NL80211_IFTYPE_P2P_GO:
507 		active = wdev->beacon_interval != 0;
508 		break;
509 	case NL80211_IFTYPE_ADHOC:
510 		active = wdev->ssid_len != 0;
511 		break;
512 	case NL80211_IFTYPE_MESH_POINT:
513 		active = wdev->mesh_id_len != 0;
514 		break;
515 	case NL80211_IFTYPE_STATION:
516 	case NL80211_IFTYPE_OCB:
517 	case NL80211_IFTYPE_P2P_CLIENT:
518 	case NL80211_IFTYPE_MONITOR:
519 	case NL80211_IFTYPE_AP_VLAN:
520 	case NL80211_IFTYPE_WDS:
521 	case NL80211_IFTYPE_P2P_DEVICE:
522 	/* Can NAN type be considered as beaconing interface? */
523 	case NL80211_IFTYPE_NAN:
524 		break;
525 	case NL80211_IFTYPE_UNSPECIFIED:
526 	case NUM_NL80211_IFTYPES:
527 		WARN_ON(1);
528 	}
529 
530 	return active;
531 }
532 
533 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
534 					struct ieee80211_channel *chan)
535 {
536 	struct wireless_dev *wdev;
537 
538 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
539 		wdev_lock(wdev);
540 		if (!cfg80211_beaconing_iface_active(wdev)) {
541 			wdev_unlock(wdev);
542 			continue;
543 		}
544 
545 		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
546 			wdev_unlock(wdev);
547 			return true;
548 		}
549 		wdev_unlock(wdev);
550 	}
551 
552 	return false;
553 }
554 
555 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
556 				  struct ieee80211_channel *chan)
557 {
558 	struct cfg80211_registered_device *rdev;
559 
560 	ASSERT_RTNL();
561 
562 	if (!(chan->flags & IEEE80211_CHAN_RADAR))
563 		return false;
564 
565 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
566 		if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
567 			continue;
568 
569 		if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
570 			return true;
571 	}
572 
573 	return false;
574 }
575 
576 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
577 					     u32 center_freq,
578 					     u32 bandwidth)
579 {
580 	struct ieee80211_channel *c;
581 	u32 freq, start_freq, end_freq;
582 
583 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
584 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
585 
586 	/*
587 	 * Check entire range of channels for the bandwidth.
588 	 * If any channel in between is disabled or has not
589 	 * had gone through CAC return false
590 	 */
591 	for (freq = start_freq; freq <= end_freq; freq += 20) {
592 		c = ieee80211_get_channel(wiphy, freq);
593 		if (!c)
594 			return false;
595 
596 		if (c->flags & IEEE80211_CHAN_DISABLED)
597 			return false;
598 
599 		if ((c->flags & IEEE80211_CHAN_RADAR)  &&
600 		    (c->dfs_state != NL80211_DFS_AVAILABLE))
601 			return false;
602 	}
603 
604 	return true;
605 }
606 
607 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
608 				const struct cfg80211_chan_def *chandef)
609 {
610 	int width;
611 	int r;
612 
613 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
614 		return false;
615 
616 	width = cfg80211_chandef_get_width(chandef);
617 	if (width < 0)
618 		return false;
619 
620 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
621 					     width);
622 
623 	/* If any of channels unavailable for cf1 just return */
624 	if (!r)
625 		return r;
626 
627 	switch (chandef->width) {
628 	case NL80211_CHAN_WIDTH_80P80:
629 		WARN_ON(!chandef->center_freq2);
630 		r = cfg80211_get_chans_dfs_available(wiphy,
631 						     chandef->center_freq2,
632 						     width);
633 		break;
634 	default:
635 		WARN_ON(chandef->center_freq2);
636 		break;
637 	}
638 
639 	return r;
640 }
641 
642 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
643 						    u32 center_freq,
644 						    u32 bandwidth)
645 {
646 	struct ieee80211_channel *c;
647 	u32 start_freq, end_freq, freq;
648 	unsigned int dfs_cac_ms = 0;
649 
650 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
651 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
652 
653 	for (freq = start_freq; freq <= end_freq; freq += 20) {
654 		c = ieee80211_get_channel(wiphy, freq);
655 		if (!c)
656 			return 0;
657 
658 		if (c->flags & IEEE80211_CHAN_DISABLED)
659 			return 0;
660 
661 		if (!(c->flags & IEEE80211_CHAN_RADAR))
662 			continue;
663 
664 		if (c->dfs_cac_ms > dfs_cac_ms)
665 			dfs_cac_ms = c->dfs_cac_ms;
666 	}
667 
668 	return dfs_cac_ms;
669 }
670 
671 unsigned int
672 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
673 			      const struct cfg80211_chan_def *chandef)
674 {
675 	int width;
676 	unsigned int t1 = 0, t2 = 0;
677 
678 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
679 		return 0;
680 
681 	width = cfg80211_chandef_get_width(chandef);
682 	if (width < 0)
683 		return 0;
684 
685 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
686 					     chandef->center_freq1,
687 					     width);
688 
689 	if (!chandef->center_freq2)
690 		return t1;
691 
692 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
693 					     chandef->center_freq2,
694 					     width);
695 
696 	return max(t1, t2);
697 }
698 
699 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
700 					u32 center_freq, u32 bandwidth,
701 					u32 prohibited_flags)
702 {
703 	struct ieee80211_channel *c;
704 	u32 freq, start_freq, end_freq;
705 
706 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
707 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
708 
709 	for (freq = start_freq; freq <= end_freq; freq += 20) {
710 		c = ieee80211_get_channel(wiphy, freq);
711 		if (!c || c->flags & prohibited_flags)
712 			return false;
713 	}
714 
715 	return true;
716 }
717 
718 bool cfg80211_chandef_usable(struct wiphy *wiphy,
719 			     const struct cfg80211_chan_def *chandef,
720 			     u32 prohibited_flags)
721 {
722 	struct ieee80211_sta_ht_cap *ht_cap;
723 	struct ieee80211_sta_vht_cap *vht_cap;
724 	u32 width, control_freq, cap;
725 
726 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
727 		return false;
728 
729 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
730 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
731 
732 	control_freq = chandef->chan->center_freq;
733 
734 	switch (chandef->width) {
735 	case NL80211_CHAN_WIDTH_5:
736 		width = 5;
737 		break;
738 	case NL80211_CHAN_WIDTH_10:
739 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
740 		width = 10;
741 		break;
742 	case NL80211_CHAN_WIDTH_20:
743 		if (!ht_cap->ht_supported)
744 			return false;
745 	case NL80211_CHAN_WIDTH_20_NOHT:
746 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
747 		width = 20;
748 		break;
749 	case NL80211_CHAN_WIDTH_40:
750 		width = 40;
751 		if (!ht_cap->ht_supported)
752 			return false;
753 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
754 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
755 			return false;
756 		if (chandef->center_freq1 < control_freq &&
757 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
758 			return false;
759 		if (chandef->center_freq1 > control_freq &&
760 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
761 			return false;
762 		break;
763 	case NL80211_CHAN_WIDTH_80P80:
764 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
765 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
766 			return false;
767 	case NL80211_CHAN_WIDTH_80:
768 		if (!vht_cap->vht_supported)
769 			return false;
770 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
771 		width = 80;
772 		break;
773 	case NL80211_CHAN_WIDTH_160:
774 		if (!vht_cap->vht_supported)
775 			return false;
776 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
777 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
778 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
779 			return false;
780 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
781 		width = 160;
782 		break;
783 	default:
784 		WARN_ON_ONCE(1);
785 		return false;
786 	}
787 
788 	/*
789 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
790 	 *	 allowed by the driver, or only certain combinations?
791 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
792 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
793 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
794 	 *	 no way to cover 80+80 MHz or more complex restrictions.
795 	 *	 Note that such restrictions also need to be advertised to
796 	 *	 userspace, for example for P2P channel selection.
797 	 */
798 
799 	if (width > 20)
800 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
801 
802 	/* 5 and 10 MHz are only defined for the OFDM PHY */
803 	if (width < 20)
804 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
805 
806 
807 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
808 					 width, prohibited_flags))
809 		return false;
810 
811 	if (!chandef->center_freq2)
812 		return true;
813 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
814 					   width, prohibited_flags);
815 }
816 EXPORT_SYMBOL(cfg80211_chandef_usable);
817 
818 /*
819  * Check if the channel can be used under permissive conditions mandated by
820  * some regulatory bodies, i.e., the channel is marked with
821  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
822  * associated to an AP on the same channel or on the same UNII band
823  * (assuming that the AP is an authorized master).
824  * In addition allow operation on a channel on which indoor operation is
825  * allowed, iff we are currently operating in an indoor environment.
826  */
827 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
828 					enum nl80211_iftype iftype,
829 					struct ieee80211_channel *chan)
830 {
831 	struct wireless_dev *wdev;
832 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
833 
834 	ASSERT_RTNL();
835 
836 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
837 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
838 		return false;
839 
840 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
841 	if (iftype != NL80211_IFTYPE_P2P_GO &&
842 	    iftype != NL80211_IFTYPE_STATION &&
843 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
844 		return false;
845 
846 	if (regulatory_indoor_allowed() &&
847 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
848 		return true;
849 
850 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
851 		return false;
852 
853 	/*
854 	 * Generally, it is possible to rely on another device/driver to allow
855 	 * the IR concurrent relaxation, however, since the device can further
856 	 * enforce the relaxation (by doing a similar verifications as this),
857 	 * and thus fail the GO instantiation, consider only the interfaces of
858 	 * the current registered device.
859 	 */
860 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
861 		struct ieee80211_channel *other_chan = NULL;
862 		int r1, r2;
863 
864 		wdev_lock(wdev);
865 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
866 		    wdev->current_bss)
867 			other_chan = wdev->current_bss->pub.channel;
868 
869 		/*
870 		 * If a GO already operates on the same GO_CONCURRENT channel,
871 		 * this one (maybe the same one) can beacon as well. We allow
872 		 * the operation even if the station we relied on with
873 		 * GO_CONCURRENT is disconnected now. But then we must make sure
874 		 * we're not outdoor on an indoor-only channel.
875 		 */
876 		if (iftype == NL80211_IFTYPE_P2P_GO &&
877 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
878 		    wdev->beacon_interval &&
879 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
880 			other_chan = wdev->chandef.chan;
881 		wdev_unlock(wdev);
882 
883 		if (!other_chan)
884 			continue;
885 
886 		if (chan == other_chan)
887 			return true;
888 
889 		if (chan->band != NL80211_BAND_5GHZ)
890 			continue;
891 
892 		r1 = cfg80211_get_unii(chan->center_freq);
893 		r2 = cfg80211_get_unii(other_chan->center_freq);
894 
895 		if (r1 != -EINVAL && r1 == r2) {
896 			/*
897 			 * At some locations channels 149-165 are considered a
898 			 * bundle, but at other locations, e.g., Indonesia,
899 			 * channels 149-161 are considered a bundle while
900 			 * channel 165 is left out and considered to be in a
901 			 * different bundle. Thus, in case that there is a
902 			 * station interface connected to an AP on channel 165,
903 			 * it is assumed that channels 149-161 are allowed for
904 			 * GO operations. However, having a station interface
905 			 * connected to an AP on channels 149-161, does not
906 			 * allow GO operation on channel 165.
907 			 */
908 			if (chan->center_freq == 5825 &&
909 			    other_chan->center_freq != 5825)
910 				continue;
911 			return true;
912 		}
913 	}
914 
915 	return false;
916 }
917 
918 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
919 				     struct cfg80211_chan_def *chandef,
920 				     enum nl80211_iftype iftype,
921 				     bool check_no_ir)
922 {
923 	bool res;
924 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
925 			       IEEE80211_CHAN_RADAR;
926 
927 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
928 
929 	if (check_no_ir)
930 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
931 
932 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
933 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
934 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
935 		prohibited_flags = IEEE80211_CHAN_DISABLED;
936 	}
937 
938 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
939 
940 	trace_cfg80211_return_bool(res);
941 	return res;
942 }
943 
944 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
945 			     struct cfg80211_chan_def *chandef,
946 			     enum nl80211_iftype iftype)
947 {
948 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
949 }
950 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
951 
952 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
953 				   struct cfg80211_chan_def *chandef,
954 				   enum nl80211_iftype iftype)
955 {
956 	bool check_no_ir;
957 
958 	ASSERT_RTNL();
959 
960 	/*
961 	 * Under certain conditions suggested by some regulatory bodies a
962 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
963 	 * only if such relaxations are not enabled and the conditions are not
964 	 * met.
965 	 */
966 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
967 						   chandef->chan);
968 
969 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
970 }
971 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
972 
973 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
974 				 struct cfg80211_chan_def *chandef)
975 {
976 	if (!rdev->ops->set_monitor_channel)
977 		return -EOPNOTSUPP;
978 	if (!cfg80211_has_monitors_only(rdev))
979 		return -EBUSY;
980 
981 	return rdev_set_monitor_channel(rdev, chandef);
982 }
983 
984 void
985 cfg80211_get_chan_state(struct wireless_dev *wdev,
986 		        struct ieee80211_channel **chan,
987 		        enum cfg80211_chan_mode *chanmode,
988 		        u8 *radar_detect)
989 {
990 	int ret;
991 
992 	*chan = NULL;
993 	*chanmode = CHAN_MODE_UNDEFINED;
994 
995 	ASSERT_WDEV_LOCK(wdev);
996 
997 	if (wdev->netdev && !netif_running(wdev->netdev))
998 		return;
999 
1000 	switch (wdev->iftype) {
1001 	case NL80211_IFTYPE_ADHOC:
1002 		if (wdev->current_bss) {
1003 			*chan = wdev->current_bss->pub.channel;
1004 			*chanmode = (wdev->ibss_fixed &&
1005 				     !wdev->ibss_dfs_possible)
1006 				  ? CHAN_MODE_SHARED
1007 				  : CHAN_MODE_EXCLUSIVE;
1008 
1009 			/* consider worst-case - IBSS can try to return to the
1010 			 * original user-specified channel as creator */
1011 			if (wdev->ibss_dfs_possible)
1012 				*radar_detect |= BIT(wdev->chandef.width);
1013 			return;
1014 		}
1015 		break;
1016 	case NL80211_IFTYPE_STATION:
1017 	case NL80211_IFTYPE_P2P_CLIENT:
1018 		if (wdev->current_bss) {
1019 			*chan = wdev->current_bss->pub.channel;
1020 			*chanmode = CHAN_MODE_SHARED;
1021 			return;
1022 		}
1023 		break;
1024 	case NL80211_IFTYPE_AP:
1025 	case NL80211_IFTYPE_P2P_GO:
1026 		if (wdev->cac_started) {
1027 			*chan = wdev->chandef.chan;
1028 			*chanmode = CHAN_MODE_SHARED;
1029 			*radar_detect |= BIT(wdev->chandef.width);
1030 		} else if (wdev->beacon_interval) {
1031 			*chan = wdev->chandef.chan;
1032 			*chanmode = CHAN_MODE_SHARED;
1033 
1034 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1035 							    &wdev->chandef,
1036 							    wdev->iftype);
1037 			WARN_ON(ret < 0);
1038 			if (ret > 0)
1039 				*radar_detect |= BIT(wdev->chandef.width);
1040 		}
1041 		return;
1042 	case NL80211_IFTYPE_MESH_POINT:
1043 		if (wdev->mesh_id_len) {
1044 			*chan = wdev->chandef.chan;
1045 			*chanmode = CHAN_MODE_SHARED;
1046 
1047 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1048 							    &wdev->chandef,
1049 							    wdev->iftype);
1050 			WARN_ON(ret < 0);
1051 			if (ret > 0)
1052 				*radar_detect |= BIT(wdev->chandef.width);
1053 		}
1054 		return;
1055 	case NL80211_IFTYPE_OCB:
1056 		if (wdev->chandef.chan) {
1057 			*chan = wdev->chandef.chan;
1058 			*chanmode = CHAN_MODE_SHARED;
1059 			return;
1060 		}
1061 		break;
1062 	case NL80211_IFTYPE_MONITOR:
1063 	case NL80211_IFTYPE_AP_VLAN:
1064 	case NL80211_IFTYPE_WDS:
1065 	case NL80211_IFTYPE_P2P_DEVICE:
1066 	case NL80211_IFTYPE_NAN:
1067 		/* these interface types don't really have a channel */
1068 		return;
1069 	case NL80211_IFTYPE_UNSPECIFIED:
1070 	case NUM_NL80211_IFTYPES:
1071 		WARN_ON(1);
1072 	}
1073 }
1074