xref: /openbmc/linux/net/wireless/chan.c (revision d3964221)
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 cf_offset, 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 	cf_offset = width / 2 - 10;
478 
479 	for (freq = chandef->center_freq1 - width / 2 + 10;
480 	     freq <= chandef->center_freq1 + width / 2 - 10; freq += 20) {
481 		if (chan->center_freq == freq)
482 			return true;
483 	}
484 
485 	if (!chandef->center_freq2)
486 		return false;
487 
488 	for (freq = chandef->center_freq2 - width / 2 + 10;
489 	     freq <= chandef->center_freq2 + width / 2 - 10; freq += 20) {
490 		if (chan->center_freq == freq)
491 			return true;
492 	}
493 
494 	return false;
495 }
496 
497 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
498 {
499 	bool active = false;
500 
501 	ASSERT_WDEV_LOCK(wdev);
502 
503 	if (!wdev->chandef.chan)
504 		return false;
505 
506 	switch (wdev->iftype) {
507 	case NL80211_IFTYPE_AP:
508 	case NL80211_IFTYPE_P2P_GO:
509 		active = wdev->beacon_interval != 0;
510 		break;
511 	case NL80211_IFTYPE_ADHOC:
512 		active = wdev->ssid_len != 0;
513 		break;
514 	case NL80211_IFTYPE_MESH_POINT:
515 		active = wdev->mesh_id_len != 0;
516 		break;
517 	case NL80211_IFTYPE_STATION:
518 	case NL80211_IFTYPE_OCB:
519 	case NL80211_IFTYPE_P2P_CLIENT:
520 	case NL80211_IFTYPE_MONITOR:
521 	case NL80211_IFTYPE_AP_VLAN:
522 	case NL80211_IFTYPE_WDS:
523 	case NL80211_IFTYPE_P2P_DEVICE:
524 	/* Can NAN type be considered as beaconing interface? */
525 	case NL80211_IFTYPE_NAN:
526 		break;
527 	case NL80211_IFTYPE_UNSPECIFIED:
528 	case NUM_NL80211_IFTYPES:
529 		WARN_ON(1);
530 	}
531 
532 	return active;
533 }
534 
535 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
536 					struct ieee80211_channel *chan)
537 {
538 	struct wireless_dev *wdev;
539 
540 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
541 		wdev_lock(wdev);
542 		if (!cfg80211_beaconing_iface_active(wdev)) {
543 			wdev_unlock(wdev);
544 			continue;
545 		}
546 
547 		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
548 			wdev_unlock(wdev);
549 			return true;
550 		}
551 		wdev_unlock(wdev);
552 	}
553 
554 	return false;
555 }
556 
557 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
558 				  struct ieee80211_channel *chan)
559 {
560 	struct cfg80211_registered_device *rdev;
561 
562 	ASSERT_RTNL();
563 
564 	if (!(chan->flags & IEEE80211_CHAN_RADAR))
565 		return false;
566 
567 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
568 		if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
569 			continue;
570 
571 		if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
572 			return true;
573 	}
574 
575 	return false;
576 }
577 
578 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
579 					     u32 center_freq,
580 					     u32 bandwidth)
581 {
582 	struct ieee80211_channel *c;
583 	u32 freq, start_freq, end_freq;
584 
585 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
586 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
587 
588 	/*
589 	 * Check entire range of channels for the bandwidth.
590 	 * If any channel in between is disabled or has not
591 	 * had gone through CAC return false
592 	 */
593 	for (freq = start_freq; freq <= end_freq; freq += 20) {
594 		c = ieee80211_get_channel(wiphy, freq);
595 		if (!c)
596 			return false;
597 
598 		if (c->flags & IEEE80211_CHAN_DISABLED)
599 			return false;
600 
601 		if ((c->flags & IEEE80211_CHAN_RADAR)  &&
602 		    (c->dfs_state != NL80211_DFS_AVAILABLE))
603 			return false;
604 	}
605 
606 	return true;
607 }
608 
609 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
610 				const struct cfg80211_chan_def *chandef)
611 {
612 	int width;
613 	int r;
614 
615 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
616 		return false;
617 
618 	width = cfg80211_chandef_get_width(chandef);
619 	if (width < 0)
620 		return false;
621 
622 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
623 					     width);
624 
625 	/* If any of channels unavailable for cf1 just return */
626 	if (!r)
627 		return r;
628 
629 	switch (chandef->width) {
630 	case NL80211_CHAN_WIDTH_80P80:
631 		WARN_ON(!chandef->center_freq2);
632 		r = cfg80211_get_chans_dfs_available(wiphy,
633 						     chandef->center_freq2,
634 						     width);
635 		break;
636 	default:
637 		WARN_ON(chandef->center_freq2);
638 		break;
639 	}
640 
641 	return r;
642 }
643 
644 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
645 						    u32 center_freq,
646 						    u32 bandwidth)
647 {
648 	struct ieee80211_channel *c;
649 	u32 start_freq, end_freq, freq;
650 	unsigned int dfs_cac_ms = 0;
651 
652 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
653 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
654 
655 	for (freq = start_freq; freq <= end_freq; freq += 20) {
656 		c = ieee80211_get_channel(wiphy, freq);
657 		if (!c)
658 			return 0;
659 
660 		if (c->flags & IEEE80211_CHAN_DISABLED)
661 			return 0;
662 
663 		if (!(c->flags & IEEE80211_CHAN_RADAR))
664 			continue;
665 
666 		if (c->dfs_cac_ms > dfs_cac_ms)
667 			dfs_cac_ms = c->dfs_cac_ms;
668 	}
669 
670 	return dfs_cac_ms;
671 }
672 
673 unsigned int
674 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
675 			      const struct cfg80211_chan_def *chandef)
676 {
677 	int width;
678 	unsigned int t1 = 0, t2 = 0;
679 
680 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
681 		return 0;
682 
683 	width = cfg80211_chandef_get_width(chandef);
684 	if (width < 0)
685 		return 0;
686 
687 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
688 					     chandef->center_freq1,
689 					     width);
690 
691 	if (!chandef->center_freq2)
692 		return t1;
693 
694 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
695 					     chandef->center_freq2,
696 					     width);
697 
698 	return max(t1, t2);
699 }
700 
701 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
702 					u32 center_freq, u32 bandwidth,
703 					u32 prohibited_flags)
704 {
705 	struct ieee80211_channel *c;
706 	u32 freq, start_freq, end_freq;
707 
708 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
709 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
710 
711 	for (freq = start_freq; freq <= end_freq; freq += 20) {
712 		c = ieee80211_get_channel(wiphy, freq);
713 		if (!c || c->flags & prohibited_flags)
714 			return false;
715 	}
716 
717 	return true;
718 }
719 
720 bool cfg80211_chandef_usable(struct wiphy *wiphy,
721 			     const struct cfg80211_chan_def *chandef,
722 			     u32 prohibited_flags)
723 {
724 	struct ieee80211_sta_ht_cap *ht_cap;
725 	struct ieee80211_sta_vht_cap *vht_cap;
726 	u32 width, control_freq, cap;
727 
728 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
729 		return false;
730 
731 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
732 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
733 
734 	control_freq = chandef->chan->center_freq;
735 
736 	switch (chandef->width) {
737 	case NL80211_CHAN_WIDTH_5:
738 		width = 5;
739 		break;
740 	case NL80211_CHAN_WIDTH_10:
741 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
742 		width = 10;
743 		break;
744 	case NL80211_CHAN_WIDTH_20:
745 		if (!ht_cap->ht_supported)
746 			return false;
747 	case NL80211_CHAN_WIDTH_20_NOHT:
748 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
749 		width = 20;
750 		break;
751 	case NL80211_CHAN_WIDTH_40:
752 		width = 40;
753 		if (!ht_cap->ht_supported)
754 			return false;
755 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
756 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
757 			return false;
758 		if (chandef->center_freq1 < control_freq &&
759 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
760 			return false;
761 		if (chandef->center_freq1 > control_freq &&
762 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
763 			return false;
764 		break;
765 	case NL80211_CHAN_WIDTH_80P80:
766 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
767 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
768 			return false;
769 	case NL80211_CHAN_WIDTH_80:
770 		if (!vht_cap->vht_supported)
771 			return false;
772 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
773 		width = 80;
774 		break;
775 	case NL80211_CHAN_WIDTH_160:
776 		if (!vht_cap->vht_supported)
777 			return false;
778 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
779 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
780 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
781 			return false;
782 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
783 		width = 160;
784 		break;
785 	default:
786 		WARN_ON_ONCE(1);
787 		return false;
788 	}
789 
790 	/*
791 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
792 	 *	 allowed by the driver, or only certain combinations?
793 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
794 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
795 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
796 	 *	 no way to cover 80+80 MHz or more complex restrictions.
797 	 *	 Note that such restrictions also need to be advertised to
798 	 *	 userspace, for example for P2P channel selection.
799 	 */
800 
801 	if (width > 20)
802 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
803 
804 	/* 5 and 10 MHz are only defined for the OFDM PHY */
805 	if (width < 20)
806 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
807 
808 
809 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
810 					 width, prohibited_flags))
811 		return false;
812 
813 	if (!chandef->center_freq2)
814 		return true;
815 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
816 					   width, prohibited_flags);
817 }
818 EXPORT_SYMBOL(cfg80211_chandef_usable);
819 
820 /*
821  * Check if the channel can be used under permissive conditions mandated by
822  * some regulatory bodies, i.e., the channel is marked with
823  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
824  * associated to an AP on the same channel or on the same UNII band
825  * (assuming that the AP is an authorized master).
826  * In addition allow operation on a channel on which indoor operation is
827  * allowed, iff we are currently operating in an indoor environment.
828  */
829 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
830 					enum nl80211_iftype iftype,
831 					struct ieee80211_channel *chan)
832 {
833 	struct wireless_dev *wdev;
834 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
835 
836 	ASSERT_RTNL();
837 
838 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
839 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
840 		return false;
841 
842 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
843 	if (iftype != NL80211_IFTYPE_P2P_GO &&
844 	    iftype != NL80211_IFTYPE_STATION &&
845 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
846 		return false;
847 
848 	if (regulatory_indoor_allowed() &&
849 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
850 		return true;
851 
852 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
853 		return false;
854 
855 	/*
856 	 * Generally, it is possible to rely on another device/driver to allow
857 	 * the IR concurrent relaxation, however, since the device can further
858 	 * enforce the relaxation (by doing a similar verifications as this),
859 	 * and thus fail the GO instantiation, consider only the interfaces of
860 	 * the current registered device.
861 	 */
862 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
863 		struct ieee80211_channel *other_chan = NULL;
864 		int r1, r2;
865 
866 		wdev_lock(wdev);
867 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
868 		    wdev->current_bss)
869 			other_chan = wdev->current_bss->pub.channel;
870 
871 		/*
872 		 * If a GO already operates on the same GO_CONCURRENT channel,
873 		 * this one (maybe the same one) can beacon as well. We allow
874 		 * the operation even if the station we relied on with
875 		 * GO_CONCURRENT is disconnected now. But then we must make sure
876 		 * we're not outdoor on an indoor-only channel.
877 		 */
878 		if (iftype == NL80211_IFTYPE_P2P_GO &&
879 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
880 		    wdev->beacon_interval &&
881 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
882 			other_chan = wdev->chandef.chan;
883 		wdev_unlock(wdev);
884 
885 		if (!other_chan)
886 			continue;
887 
888 		if (chan == other_chan)
889 			return true;
890 
891 		if (chan->band != NL80211_BAND_5GHZ)
892 			continue;
893 
894 		r1 = cfg80211_get_unii(chan->center_freq);
895 		r2 = cfg80211_get_unii(other_chan->center_freq);
896 
897 		if (r1 != -EINVAL && r1 == r2) {
898 			/*
899 			 * At some locations channels 149-165 are considered a
900 			 * bundle, but at other locations, e.g., Indonesia,
901 			 * channels 149-161 are considered a bundle while
902 			 * channel 165 is left out and considered to be in a
903 			 * different bundle. Thus, in case that there is a
904 			 * station interface connected to an AP on channel 165,
905 			 * it is assumed that channels 149-161 are allowed for
906 			 * GO operations. However, having a station interface
907 			 * connected to an AP on channels 149-161, does not
908 			 * allow GO operation on channel 165.
909 			 */
910 			if (chan->center_freq == 5825 &&
911 			    other_chan->center_freq != 5825)
912 				continue;
913 			return true;
914 		}
915 	}
916 
917 	return false;
918 }
919 
920 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
921 				     struct cfg80211_chan_def *chandef,
922 				     enum nl80211_iftype iftype,
923 				     bool check_no_ir)
924 {
925 	bool res;
926 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
927 			       IEEE80211_CHAN_RADAR;
928 
929 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
930 
931 	if (check_no_ir)
932 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
933 
934 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
935 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
936 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
937 		prohibited_flags = IEEE80211_CHAN_DISABLED;
938 	}
939 
940 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
941 
942 	trace_cfg80211_return_bool(res);
943 	return res;
944 }
945 
946 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
947 			     struct cfg80211_chan_def *chandef,
948 			     enum nl80211_iftype iftype)
949 {
950 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
951 }
952 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
953 
954 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
955 				   struct cfg80211_chan_def *chandef,
956 				   enum nl80211_iftype iftype)
957 {
958 	bool check_no_ir;
959 
960 	ASSERT_RTNL();
961 
962 	/*
963 	 * Under certain conditions suggested by some regulatory bodies a
964 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
965 	 * only if such relaxations are not enabled and the conditions are not
966 	 * met.
967 	 */
968 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
969 						   chandef->chan);
970 
971 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
972 }
973 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
974 
975 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
976 				 struct cfg80211_chan_def *chandef)
977 {
978 	if (!rdev->ops->set_monitor_channel)
979 		return -EOPNOTSUPP;
980 	if (!cfg80211_has_monitors_only(rdev))
981 		return -EBUSY;
982 
983 	return rdev_set_monitor_channel(rdev, chandef);
984 }
985 
986 void
987 cfg80211_get_chan_state(struct wireless_dev *wdev,
988 		        struct ieee80211_channel **chan,
989 		        enum cfg80211_chan_mode *chanmode,
990 		        u8 *radar_detect)
991 {
992 	int ret;
993 
994 	*chan = NULL;
995 	*chanmode = CHAN_MODE_UNDEFINED;
996 
997 	ASSERT_WDEV_LOCK(wdev);
998 
999 	if (wdev->netdev && !netif_running(wdev->netdev))
1000 		return;
1001 
1002 	switch (wdev->iftype) {
1003 	case NL80211_IFTYPE_ADHOC:
1004 		if (wdev->current_bss) {
1005 			*chan = wdev->current_bss->pub.channel;
1006 			*chanmode = (wdev->ibss_fixed &&
1007 				     !wdev->ibss_dfs_possible)
1008 				  ? CHAN_MODE_SHARED
1009 				  : CHAN_MODE_EXCLUSIVE;
1010 
1011 			/* consider worst-case - IBSS can try to return to the
1012 			 * original user-specified channel as creator */
1013 			if (wdev->ibss_dfs_possible)
1014 				*radar_detect |= BIT(wdev->chandef.width);
1015 			return;
1016 		}
1017 		break;
1018 	case NL80211_IFTYPE_STATION:
1019 	case NL80211_IFTYPE_P2P_CLIENT:
1020 		if (wdev->current_bss) {
1021 			*chan = wdev->current_bss->pub.channel;
1022 			*chanmode = CHAN_MODE_SHARED;
1023 			return;
1024 		}
1025 		break;
1026 	case NL80211_IFTYPE_AP:
1027 	case NL80211_IFTYPE_P2P_GO:
1028 		if (wdev->cac_started) {
1029 			*chan = wdev->chandef.chan;
1030 			*chanmode = CHAN_MODE_SHARED;
1031 			*radar_detect |= BIT(wdev->chandef.width);
1032 		} else if (wdev->beacon_interval) {
1033 			*chan = wdev->chandef.chan;
1034 			*chanmode = CHAN_MODE_SHARED;
1035 
1036 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1037 							    &wdev->chandef,
1038 							    wdev->iftype);
1039 			WARN_ON(ret < 0);
1040 			if (ret > 0)
1041 				*radar_detect |= BIT(wdev->chandef.width);
1042 		}
1043 		return;
1044 	case NL80211_IFTYPE_MESH_POINT:
1045 		if (wdev->mesh_id_len) {
1046 			*chan = wdev->chandef.chan;
1047 			*chanmode = CHAN_MODE_SHARED;
1048 
1049 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1050 							    &wdev->chandef,
1051 							    wdev->iftype);
1052 			WARN_ON(ret < 0);
1053 			if (ret > 0)
1054 				*radar_detect |= BIT(wdev->chandef.width);
1055 		}
1056 		return;
1057 	case NL80211_IFTYPE_OCB:
1058 		if (wdev->chandef.chan) {
1059 			*chan = wdev->chandef.chan;
1060 			*chanmode = CHAN_MODE_SHARED;
1061 			return;
1062 		}
1063 		break;
1064 	case NL80211_IFTYPE_MONITOR:
1065 	case NL80211_IFTYPE_AP_VLAN:
1066 	case NL80211_IFTYPE_WDS:
1067 	case NL80211_IFTYPE_P2P_DEVICE:
1068 	case NL80211_IFTYPE_NAN:
1069 		/* these interface types don't really have a channel */
1070 		return;
1071 	case NL80211_IFTYPE_UNSPECIFIED:
1072 	case NUM_NL80211_IFTYPES:
1073 		WARN_ON(1);
1074 	}
1075 }
1076