xref: /openbmc/linux/net/wireless/chan.c (revision be709d48)
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  * Copyright 2018       Intel Corporation
10  */
11 
12 #include <linux/export.h>
13 #include <net/cfg80211.h>
14 #include "core.h"
15 #include "rdev-ops.h"
16 
17 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
18 			     struct ieee80211_channel *chan,
19 			     enum nl80211_channel_type chan_type)
20 {
21 	if (WARN_ON(!chan))
22 		return;
23 
24 	chandef->chan = chan;
25 	chandef->center_freq2 = 0;
26 
27 	switch (chan_type) {
28 	case NL80211_CHAN_NO_HT:
29 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
30 		chandef->center_freq1 = chan->center_freq;
31 		break;
32 	case NL80211_CHAN_HT20:
33 		chandef->width = NL80211_CHAN_WIDTH_20;
34 		chandef->center_freq1 = chan->center_freq;
35 		break;
36 	case NL80211_CHAN_HT40PLUS:
37 		chandef->width = NL80211_CHAN_WIDTH_40;
38 		chandef->center_freq1 = chan->center_freq + 10;
39 		break;
40 	case NL80211_CHAN_HT40MINUS:
41 		chandef->width = NL80211_CHAN_WIDTH_40;
42 		chandef->center_freq1 = chan->center_freq - 10;
43 		break;
44 	default:
45 		WARN_ON(1);
46 	}
47 }
48 EXPORT_SYMBOL(cfg80211_chandef_create);
49 
50 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
51 {
52 	u32 control_freq;
53 
54 	if (!chandef->chan)
55 		return false;
56 
57 	control_freq = chandef->chan->center_freq;
58 
59 	switch (chandef->width) {
60 	case NL80211_CHAN_WIDTH_5:
61 	case NL80211_CHAN_WIDTH_10:
62 	case NL80211_CHAN_WIDTH_20:
63 	case NL80211_CHAN_WIDTH_20_NOHT:
64 		if (chandef->center_freq1 != control_freq)
65 			return false;
66 		if (chandef->center_freq2)
67 			return false;
68 		break;
69 	case NL80211_CHAN_WIDTH_40:
70 		if (chandef->center_freq1 != control_freq + 10 &&
71 		    chandef->center_freq1 != control_freq - 10)
72 			return false;
73 		if (chandef->center_freq2)
74 			return false;
75 		break;
76 	case NL80211_CHAN_WIDTH_80P80:
77 		if (chandef->center_freq1 != control_freq + 30 &&
78 		    chandef->center_freq1 != control_freq + 10 &&
79 		    chandef->center_freq1 != control_freq - 10 &&
80 		    chandef->center_freq1 != control_freq - 30)
81 			return false;
82 		if (!chandef->center_freq2)
83 			return false;
84 		/* adjacent is not allowed -- that's a 160 MHz channel */
85 		if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
86 		    chandef->center_freq2 - chandef->center_freq1 == 80)
87 			return false;
88 		break;
89 	case NL80211_CHAN_WIDTH_80:
90 		if (chandef->center_freq1 != control_freq + 30 &&
91 		    chandef->center_freq1 != control_freq + 10 &&
92 		    chandef->center_freq1 != control_freq - 10 &&
93 		    chandef->center_freq1 != control_freq - 30)
94 			return false;
95 		if (chandef->center_freq2)
96 			return false;
97 		break;
98 	case NL80211_CHAN_WIDTH_160:
99 		if (chandef->center_freq1 != control_freq + 70 &&
100 		    chandef->center_freq1 != control_freq + 50 &&
101 		    chandef->center_freq1 != control_freq + 30 &&
102 		    chandef->center_freq1 != control_freq + 10 &&
103 		    chandef->center_freq1 != control_freq - 10 &&
104 		    chandef->center_freq1 != control_freq - 30 &&
105 		    chandef->center_freq1 != control_freq - 50 &&
106 		    chandef->center_freq1 != control_freq - 70)
107 			return false;
108 		if (chandef->center_freq2)
109 			return false;
110 		break;
111 	default:
112 		return false;
113 	}
114 
115 	return true;
116 }
117 EXPORT_SYMBOL(cfg80211_chandef_valid);
118 
119 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
120 				  u32 *pri40, u32 *pri80)
121 {
122 	int tmp;
123 
124 	switch (c->width) {
125 	case NL80211_CHAN_WIDTH_40:
126 		*pri40 = c->center_freq1;
127 		*pri80 = 0;
128 		break;
129 	case NL80211_CHAN_WIDTH_80:
130 	case NL80211_CHAN_WIDTH_80P80:
131 		*pri80 = c->center_freq1;
132 		/* n_P20 */
133 		tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
134 		/* n_P40 */
135 		tmp /= 2;
136 		/* freq_P40 */
137 		*pri40 = c->center_freq1 - 20 + 40 * tmp;
138 		break;
139 	case NL80211_CHAN_WIDTH_160:
140 		/* n_P20 */
141 		tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
142 		/* n_P40 */
143 		tmp /= 2;
144 		/* freq_P40 */
145 		*pri40 = c->center_freq1 - 60 + 40 * tmp;
146 		/* n_P80 */
147 		tmp /= 2;
148 		*pri80 = c->center_freq1 - 40 + 80 * tmp;
149 		break;
150 	default:
151 		WARN_ON_ONCE(1);
152 	}
153 }
154 
155 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
156 {
157 	int width;
158 
159 	switch (c->width) {
160 	case NL80211_CHAN_WIDTH_5:
161 		width = 5;
162 		break;
163 	case NL80211_CHAN_WIDTH_10:
164 		width = 10;
165 		break;
166 	case NL80211_CHAN_WIDTH_20:
167 	case NL80211_CHAN_WIDTH_20_NOHT:
168 		width = 20;
169 		break;
170 	case NL80211_CHAN_WIDTH_40:
171 		width = 40;
172 		break;
173 	case NL80211_CHAN_WIDTH_80P80:
174 	case NL80211_CHAN_WIDTH_80:
175 		width = 80;
176 		break;
177 	case NL80211_CHAN_WIDTH_160:
178 		width = 160;
179 		break;
180 	default:
181 		WARN_ON_ONCE(1);
182 		return -1;
183 	}
184 	return width;
185 }
186 
187 const struct cfg80211_chan_def *
188 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
189 			    const struct cfg80211_chan_def *c2)
190 {
191 	u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
192 
193 	/* If they are identical, return */
194 	if (cfg80211_chandef_identical(c1, c2))
195 		return c1;
196 
197 	/* otherwise, must have same control channel */
198 	if (c1->chan != c2->chan)
199 		return NULL;
200 
201 	/*
202 	 * If they have the same width, but aren't identical,
203 	 * then they can't be compatible.
204 	 */
205 	if (c1->width == c2->width)
206 		return NULL;
207 
208 	/*
209 	 * can't be compatible if one of them is 5 or 10 MHz,
210 	 * but they don't have the same width.
211 	 */
212 	if (c1->width == NL80211_CHAN_WIDTH_5 ||
213 	    c1->width == NL80211_CHAN_WIDTH_10 ||
214 	    c2->width == NL80211_CHAN_WIDTH_5 ||
215 	    c2->width == NL80211_CHAN_WIDTH_10)
216 		return NULL;
217 
218 	if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
219 	    c1->width == NL80211_CHAN_WIDTH_20)
220 		return c2;
221 
222 	if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
223 	    c2->width == NL80211_CHAN_WIDTH_20)
224 		return c1;
225 
226 	chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
227 	chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
228 
229 	if (c1_pri40 != c2_pri40)
230 		return NULL;
231 
232 	WARN_ON(!c1_pri80 && !c2_pri80);
233 	if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
234 		return NULL;
235 
236 	if (c1->width > c2->width)
237 		return c1;
238 	return c2;
239 }
240 EXPORT_SYMBOL(cfg80211_chandef_compatible);
241 
242 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
243 					 u32 bandwidth,
244 					 enum nl80211_dfs_state dfs_state)
245 {
246 	struct ieee80211_channel *c;
247 	u32 freq;
248 
249 	for (freq = center_freq - bandwidth/2 + 10;
250 	     freq <= center_freq + bandwidth/2 - 10;
251 	     freq += 20) {
252 		c = ieee80211_get_channel(wiphy, freq);
253 		if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
254 			continue;
255 
256 		c->dfs_state = dfs_state;
257 		c->dfs_state_entered = jiffies;
258 	}
259 }
260 
261 void cfg80211_set_dfs_state(struct wiphy *wiphy,
262 			    const struct cfg80211_chan_def *chandef,
263 			    enum nl80211_dfs_state dfs_state)
264 {
265 	int width;
266 
267 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
268 		return;
269 
270 	width = cfg80211_chandef_get_width(chandef);
271 	if (width < 0)
272 		return;
273 
274 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
275 				     width, dfs_state);
276 
277 	if (!chandef->center_freq2)
278 		return;
279 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
280 				     width, dfs_state);
281 }
282 
283 static u32 cfg80211_get_start_freq(u32 center_freq,
284 				   u32 bandwidth)
285 {
286 	u32 start_freq;
287 
288 	if (bandwidth <= 20)
289 		start_freq = center_freq;
290 	else
291 		start_freq = center_freq - bandwidth/2 + 10;
292 
293 	return start_freq;
294 }
295 
296 static u32 cfg80211_get_end_freq(u32 center_freq,
297 				 u32 bandwidth)
298 {
299 	u32 end_freq;
300 
301 	if (bandwidth <= 20)
302 		end_freq = center_freq;
303 	else
304 		end_freq = center_freq + bandwidth/2 - 10;
305 
306 	return end_freq;
307 }
308 
309 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
310 					    u32 center_freq,
311 					    u32 bandwidth)
312 {
313 	struct ieee80211_channel *c;
314 	u32 freq, start_freq, end_freq;
315 
316 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
317 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
318 
319 	for (freq = start_freq; freq <= end_freq; freq += 20) {
320 		c = ieee80211_get_channel(wiphy, freq);
321 		if (!c)
322 			return -EINVAL;
323 
324 		if (c->flags & IEEE80211_CHAN_RADAR)
325 			return 1;
326 	}
327 	return 0;
328 }
329 
330 
331 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
332 				  const struct cfg80211_chan_def *chandef,
333 				  enum nl80211_iftype iftype)
334 {
335 	int width;
336 	int ret;
337 
338 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
339 		return -EINVAL;
340 
341 	switch (iftype) {
342 	case NL80211_IFTYPE_ADHOC:
343 	case NL80211_IFTYPE_AP:
344 	case NL80211_IFTYPE_P2P_GO:
345 	case NL80211_IFTYPE_MESH_POINT:
346 		width = cfg80211_chandef_get_width(chandef);
347 		if (width < 0)
348 			return -EINVAL;
349 
350 		ret = cfg80211_get_chans_dfs_required(wiphy,
351 						      chandef->center_freq1,
352 						      width);
353 		if (ret < 0)
354 			return ret;
355 		else if (ret > 0)
356 			return BIT(chandef->width);
357 
358 		if (!chandef->center_freq2)
359 			return 0;
360 
361 		ret = cfg80211_get_chans_dfs_required(wiphy,
362 						      chandef->center_freq2,
363 						      width);
364 		if (ret < 0)
365 			return ret;
366 		else if (ret > 0)
367 			return BIT(chandef->width);
368 
369 		break;
370 	case NL80211_IFTYPE_STATION:
371 	case NL80211_IFTYPE_OCB:
372 	case NL80211_IFTYPE_P2P_CLIENT:
373 	case NL80211_IFTYPE_MONITOR:
374 	case NL80211_IFTYPE_AP_VLAN:
375 	case NL80211_IFTYPE_WDS:
376 	case NL80211_IFTYPE_P2P_DEVICE:
377 	case NL80211_IFTYPE_NAN:
378 		break;
379 	case NL80211_IFTYPE_UNSPECIFIED:
380 	case NUM_NL80211_IFTYPES:
381 		WARN_ON(1);
382 	}
383 
384 	return 0;
385 }
386 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
387 
388 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
389 					 u32 center_freq,
390 					 u32 bandwidth)
391 {
392 	struct ieee80211_channel *c;
393 	u32 freq, start_freq, end_freq;
394 	int count = 0;
395 
396 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
397 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
398 
399 	/*
400 	 * Check entire range of channels for the bandwidth.
401 	 * Check all channels are DFS channels (DFS_USABLE or
402 	 * DFS_AVAILABLE). Return number of usable channels
403 	 * (require CAC). Allow DFS and non-DFS channel mix.
404 	 */
405 	for (freq = start_freq; freq <= end_freq; freq += 20) {
406 		c = ieee80211_get_channel(wiphy, freq);
407 		if (!c)
408 			return -EINVAL;
409 
410 		if (c->flags & IEEE80211_CHAN_DISABLED)
411 			return -EINVAL;
412 
413 		if (c->flags & IEEE80211_CHAN_RADAR) {
414 			if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
415 				return -EINVAL;
416 
417 			if (c->dfs_state == NL80211_DFS_USABLE)
418 				count++;
419 		}
420 	}
421 
422 	return count;
423 }
424 
425 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
426 				 const struct cfg80211_chan_def *chandef)
427 {
428 	int width;
429 	int r1, r2 = 0;
430 
431 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
432 		return false;
433 
434 	width = cfg80211_chandef_get_width(chandef);
435 	if (width < 0)
436 		return false;
437 
438 	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
439 					  width);
440 
441 	if (r1 < 0)
442 		return false;
443 
444 	switch (chandef->width) {
445 	case NL80211_CHAN_WIDTH_80P80:
446 		WARN_ON(!chandef->center_freq2);
447 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
448 						   chandef->center_freq2,
449 						   width);
450 		if (r2 < 0)
451 			return false;
452 		break;
453 	default:
454 		WARN_ON(chandef->center_freq2);
455 		break;
456 	}
457 
458 	return (r1 + r2 > 0);
459 }
460 
461 /*
462  * Checks if center frequency of chan falls with in the bandwidth
463  * range of chandef.
464  */
465 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
466 			  struct ieee80211_channel *chan)
467 {
468 	int width;
469 	u32 freq;
470 
471 	if (chandef->chan->center_freq == chan->center_freq)
472 		return true;
473 
474 	width = cfg80211_chandef_get_width(chandef);
475 	if (width <= 20)
476 		return false;
477 
478 	for (freq = chandef->center_freq1 - width / 2 + 10;
479 	     freq <= chandef->center_freq1 + width / 2 - 10; freq += 20) {
480 		if (chan->center_freq == freq)
481 			return true;
482 	}
483 
484 	if (!chandef->center_freq2)
485 		return false;
486 
487 	for (freq = chandef->center_freq2 - width / 2 + 10;
488 	     freq <= chandef->center_freq2 + width / 2 - 10; freq += 20) {
489 		if (chan->center_freq == freq)
490 			return true;
491 	}
492 
493 	return false;
494 }
495 
496 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
497 {
498 	bool active = false;
499 
500 	ASSERT_WDEV_LOCK(wdev);
501 
502 	if (!wdev->chandef.chan)
503 		return false;
504 
505 	switch (wdev->iftype) {
506 	case NL80211_IFTYPE_AP:
507 	case NL80211_IFTYPE_P2P_GO:
508 		active = wdev->beacon_interval != 0;
509 		break;
510 	case NL80211_IFTYPE_ADHOC:
511 		active = wdev->ssid_len != 0;
512 		break;
513 	case NL80211_IFTYPE_MESH_POINT:
514 		active = wdev->mesh_id_len != 0;
515 		break;
516 	case NL80211_IFTYPE_STATION:
517 	case NL80211_IFTYPE_OCB:
518 	case NL80211_IFTYPE_P2P_CLIENT:
519 	case NL80211_IFTYPE_MONITOR:
520 	case NL80211_IFTYPE_AP_VLAN:
521 	case NL80211_IFTYPE_WDS:
522 	case NL80211_IFTYPE_P2P_DEVICE:
523 	/* Can NAN type be considered as beaconing interface? */
524 	case NL80211_IFTYPE_NAN:
525 		break;
526 	case NL80211_IFTYPE_UNSPECIFIED:
527 	case NUM_NL80211_IFTYPES:
528 		WARN_ON(1);
529 	}
530 
531 	return active;
532 }
533 
534 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
535 					struct ieee80211_channel *chan)
536 {
537 	struct wireless_dev *wdev;
538 
539 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
540 		wdev_lock(wdev);
541 		if (!cfg80211_beaconing_iface_active(wdev)) {
542 			wdev_unlock(wdev);
543 			continue;
544 		}
545 
546 		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
547 			wdev_unlock(wdev);
548 			return true;
549 		}
550 		wdev_unlock(wdev);
551 	}
552 
553 	return false;
554 }
555 
556 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
557 				  struct ieee80211_channel *chan)
558 {
559 	struct cfg80211_registered_device *rdev;
560 
561 	ASSERT_RTNL();
562 
563 	if (!(chan->flags & IEEE80211_CHAN_RADAR))
564 		return false;
565 
566 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
567 		if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
568 			continue;
569 
570 		if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
571 			return true;
572 	}
573 
574 	return false;
575 }
576 
577 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
578 					     u32 center_freq,
579 					     u32 bandwidth)
580 {
581 	struct ieee80211_channel *c;
582 	u32 freq, start_freq, end_freq;
583 	bool dfs_offload;
584 
585 	dfs_offload = wiphy_ext_feature_isset(wiphy,
586 					      NL80211_EXT_FEATURE_DFS_OFFLOAD);
587 
588 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
589 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
590 
591 	/*
592 	 * Check entire range of channels for the bandwidth.
593 	 * If any channel in between is disabled or has not
594 	 * had gone through CAC return false
595 	 */
596 	for (freq = start_freq; freq <= end_freq; freq += 20) {
597 		c = ieee80211_get_channel(wiphy, freq);
598 		if (!c)
599 			return false;
600 
601 		if (c->flags & IEEE80211_CHAN_DISABLED)
602 			return false;
603 
604 		if ((c->flags & IEEE80211_CHAN_RADAR) &&
605 		    (c->dfs_state != NL80211_DFS_AVAILABLE) &&
606 		    !(c->dfs_state == NL80211_DFS_USABLE && dfs_offload))
607 			return false;
608 	}
609 
610 	return true;
611 }
612 
613 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
614 				const struct cfg80211_chan_def *chandef)
615 {
616 	int width;
617 	int r;
618 
619 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
620 		return false;
621 
622 	width = cfg80211_chandef_get_width(chandef);
623 	if (width < 0)
624 		return false;
625 
626 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
627 					     width);
628 
629 	/* If any of channels unavailable for cf1 just return */
630 	if (!r)
631 		return r;
632 
633 	switch (chandef->width) {
634 	case NL80211_CHAN_WIDTH_80P80:
635 		WARN_ON(!chandef->center_freq2);
636 		r = cfg80211_get_chans_dfs_available(wiphy,
637 						     chandef->center_freq2,
638 						     width);
639 		break;
640 	default:
641 		WARN_ON(chandef->center_freq2);
642 		break;
643 	}
644 
645 	return r;
646 }
647 
648 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
649 						    u32 center_freq,
650 						    u32 bandwidth)
651 {
652 	struct ieee80211_channel *c;
653 	u32 start_freq, end_freq, freq;
654 	unsigned int dfs_cac_ms = 0;
655 
656 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
657 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
658 
659 	for (freq = start_freq; freq <= end_freq; freq += 20) {
660 		c = ieee80211_get_channel(wiphy, freq);
661 		if (!c)
662 			return 0;
663 
664 		if (c->flags & IEEE80211_CHAN_DISABLED)
665 			return 0;
666 
667 		if (!(c->flags & IEEE80211_CHAN_RADAR))
668 			continue;
669 
670 		if (c->dfs_cac_ms > dfs_cac_ms)
671 			dfs_cac_ms = c->dfs_cac_ms;
672 	}
673 
674 	return dfs_cac_ms;
675 }
676 
677 unsigned int
678 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
679 			      const struct cfg80211_chan_def *chandef)
680 {
681 	int width;
682 	unsigned int t1 = 0, t2 = 0;
683 
684 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
685 		return 0;
686 
687 	width = cfg80211_chandef_get_width(chandef);
688 	if (width < 0)
689 		return 0;
690 
691 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
692 					     chandef->center_freq1,
693 					     width);
694 
695 	if (!chandef->center_freq2)
696 		return t1;
697 
698 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
699 					     chandef->center_freq2,
700 					     width);
701 
702 	return max(t1, t2);
703 }
704 
705 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
706 					u32 center_freq, u32 bandwidth,
707 					u32 prohibited_flags)
708 {
709 	struct ieee80211_channel *c;
710 	u32 freq, start_freq, end_freq;
711 
712 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
713 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
714 
715 	for (freq = start_freq; freq <= end_freq; freq += 20) {
716 		c = ieee80211_get_channel(wiphy, freq);
717 		if (!c || c->flags & prohibited_flags)
718 			return false;
719 	}
720 
721 	return true;
722 }
723 
724 bool cfg80211_chandef_usable(struct wiphy *wiphy,
725 			     const struct cfg80211_chan_def *chandef,
726 			     u32 prohibited_flags)
727 {
728 	struct ieee80211_sta_ht_cap *ht_cap;
729 	struct ieee80211_sta_vht_cap *vht_cap;
730 	u32 width, control_freq, cap;
731 
732 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
733 		return false;
734 
735 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
736 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
737 
738 	control_freq = chandef->chan->center_freq;
739 
740 	switch (chandef->width) {
741 	case NL80211_CHAN_WIDTH_5:
742 		width = 5;
743 		break;
744 	case NL80211_CHAN_WIDTH_10:
745 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
746 		width = 10;
747 		break;
748 	case NL80211_CHAN_WIDTH_20:
749 		if (!ht_cap->ht_supported)
750 			return false;
751 		/* fall through */
752 	case NL80211_CHAN_WIDTH_20_NOHT:
753 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
754 		width = 20;
755 		break;
756 	case NL80211_CHAN_WIDTH_40:
757 		width = 40;
758 		if (!ht_cap->ht_supported)
759 			return false;
760 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
761 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
762 			return false;
763 		if (chandef->center_freq1 < control_freq &&
764 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
765 			return false;
766 		if (chandef->center_freq1 > control_freq &&
767 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
768 			return false;
769 		break;
770 	case NL80211_CHAN_WIDTH_80P80:
771 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
772 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
773 			return false;
774 		/* fall through */
775 	case NL80211_CHAN_WIDTH_80:
776 		if (!vht_cap->vht_supported)
777 			return false;
778 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
779 		width = 80;
780 		break;
781 	case NL80211_CHAN_WIDTH_160:
782 		if (!vht_cap->vht_supported)
783 			return false;
784 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
785 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
786 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
787 			return false;
788 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
789 		width = 160;
790 		break;
791 	default:
792 		WARN_ON_ONCE(1);
793 		return false;
794 	}
795 
796 	/*
797 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
798 	 *	 allowed by the driver, or only certain combinations?
799 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
800 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
801 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
802 	 *	 no way to cover 80+80 MHz or more complex restrictions.
803 	 *	 Note that such restrictions also need to be advertised to
804 	 *	 userspace, for example for P2P channel selection.
805 	 */
806 
807 	if (width > 20)
808 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
809 
810 	/* 5 and 10 MHz are only defined for the OFDM PHY */
811 	if (width < 20)
812 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
813 
814 
815 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
816 					 width, prohibited_flags))
817 		return false;
818 
819 	if (!chandef->center_freq2)
820 		return true;
821 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
822 					   width, prohibited_flags);
823 }
824 EXPORT_SYMBOL(cfg80211_chandef_usable);
825 
826 /*
827  * Check if the channel can be used under permissive conditions mandated by
828  * some regulatory bodies, i.e., the channel is marked with
829  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
830  * associated to an AP on the same channel or on the same UNII band
831  * (assuming that the AP is an authorized master).
832  * In addition allow operation on a channel on which indoor operation is
833  * allowed, iff we are currently operating in an indoor environment.
834  */
835 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
836 					enum nl80211_iftype iftype,
837 					struct ieee80211_channel *chan)
838 {
839 	struct wireless_dev *wdev;
840 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
841 
842 	ASSERT_RTNL();
843 
844 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
845 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
846 		return false;
847 
848 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
849 	if (iftype != NL80211_IFTYPE_P2P_GO &&
850 	    iftype != NL80211_IFTYPE_STATION &&
851 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
852 		return false;
853 
854 	if (regulatory_indoor_allowed() &&
855 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
856 		return true;
857 
858 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
859 		return false;
860 
861 	/*
862 	 * Generally, it is possible to rely on another device/driver to allow
863 	 * the IR concurrent relaxation, however, since the device can further
864 	 * enforce the relaxation (by doing a similar verifications as this),
865 	 * and thus fail the GO instantiation, consider only the interfaces of
866 	 * the current registered device.
867 	 */
868 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
869 		struct ieee80211_channel *other_chan = NULL;
870 		int r1, r2;
871 
872 		wdev_lock(wdev);
873 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
874 		    wdev->current_bss)
875 			other_chan = wdev->current_bss->pub.channel;
876 
877 		/*
878 		 * If a GO already operates on the same GO_CONCURRENT channel,
879 		 * this one (maybe the same one) can beacon as well. We allow
880 		 * the operation even if the station we relied on with
881 		 * GO_CONCURRENT is disconnected now. But then we must make sure
882 		 * we're not outdoor on an indoor-only channel.
883 		 */
884 		if (iftype == NL80211_IFTYPE_P2P_GO &&
885 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
886 		    wdev->beacon_interval &&
887 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
888 			other_chan = wdev->chandef.chan;
889 		wdev_unlock(wdev);
890 
891 		if (!other_chan)
892 			continue;
893 
894 		if (chan == other_chan)
895 			return true;
896 
897 		if (chan->band != NL80211_BAND_5GHZ)
898 			continue;
899 
900 		r1 = cfg80211_get_unii(chan->center_freq);
901 		r2 = cfg80211_get_unii(other_chan->center_freq);
902 
903 		if (r1 != -EINVAL && r1 == r2) {
904 			/*
905 			 * At some locations channels 149-165 are considered a
906 			 * bundle, but at other locations, e.g., Indonesia,
907 			 * channels 149-161 are considered a bundle while
908 			 * channel 165 is left out and considered to be in a
909 			 * different bundle. Thus, in case that there is a
910 			 * station interface connected to an AP on channel 165,
911 			 * it is assumed that channels 149-161 are allowed for
912 			 * GO operations. However, having a station interface
913 			 * connected to an AP on channels 149-161, does not
914 			 * allow GO operation on channel 165.
915 			 */
916 			if (chan->center_freq == 5825 &&
917 			    other_chan->center_freq != 5825)
918 				continue;
919 			return true;
920 		}
921 	}
922 
923 	return false;
924 }
925 
926 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
927 				     struct cfg80211_chan_def *chandef,
928 				     enum nl80211_iftype iftype,
929 				     bool check_no_ir)
930 {
931 	bool res;
932 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
933 			       IEEE80211_CHAN_RADAR;
934 
935 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
936 
937 	if (check_no_ir)
938 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
939 
940 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
941 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
942 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
943 		prohibited_flags = IEEE80211_CHAN_DISABLED;
944 	}
945 
946 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
947 
948 	trace_cfg80211_return_bool(res);
949 	return res;
950 }
951 
952 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
953 			     struct cfg80211_chan_def *chandef,
954 			     enum nl80211_iftype iftype)
955 {
956 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
957 }
958 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
959 
960 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
961 				   struct cfg80211_chan_def *chandef,
962 				   enum nl80211_iftype iftype)
963 {
964 	bool check_no_ir;
965 
966 	ASSERT_RTNL();
967 
968 	/*
969 	 * Under certain conditions suggested by some regulatory bodies a
970 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
971 	 * only if such relaxations are not enabled and the conditions are not
972 	 * met.
973 	 */
974 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
975 						   chandef->chan);
976 
977 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
978 }
979 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
980 
981 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
982 				 struct cfg80211_chan_def *chandef)
983 {
984 	if (!rdev->ops->set_monitor_channel)
985 		return -EOPNOTSUPP;
986 	if (!cfg80211_has_monitors_only(rdev))
987 		return -EBUSY;
988 
989 	return rdev_set_monitor_channel(rdev, chandef);
990 }
991 
992 void
993 cfg80211_get_chan_state(struct wireless_dev *wdev,
994 		        struct ieee80211_channel **chan,
995 		        enum cfg80211_chan_mode *chanmode,
996 		        u8 *radar_detect)
997 {
998 	int ret;
999 
1000 	*chan = NULL;
1001 	*chanmode = CHAN_MODE_UNDEFINED;
1002 
1003 	ASSERT_WDEV_LOCK(wdev);
1004 
1005 	if (wdev->netdev && !netif_running(wdev->netdev))
1006 		return;
1007 
1008 	switch (wdev->iftype) {
1009 	case NL80211_IFTYPE_ADHOC:
1010 		if (wdev->current_bss) {
1011 			*chan = wdev->current_bss->pub.channel;
1012 			*chanmode = (wdev->ibss_fixed &&
1013 				     !wdev->ibss_dfs_possible)
1014 				  ? CHAN_MODE_SHARED
1015 				  : CHAN_MODE_EXCLUSIVE;
1016 
1017 			/* consider worst-case - IBSS can try to return to the
1018 			 * original user-specified channel as creator */
1019 			if (wdev->ibss_dfs_possible)
1020 				*radar_detect |= BIT(wdev->chandef.width);
1021 			return;
1022 		}
1023 		break;
1024 	case NL80211_IFTYPE_STATION:
1025 	case NL80211_IFTYPE_P2P_CLIENT:
1026 		if (wdev->current_bss) {
1027 			*chan = wdev->current_bss->pub.channel;
1028 			*chanmode = CHAN_MODE_SHARED;
1029 			return;
1030 		}
1031 		break;
1032 	case NL80211_IFTYPE_AP:
1033 	case NL80211_IFTYPE_P2P_GO:
1034 		if (wdev->cac_started) {
1035 			*chan = wdev->chandef.chan;
1036 			*chanmode = CHAN_MODE_SHARED;
1037 			*radar_detect |= BIT(wdev->chandef.width);
1038 		} else if (wdev->beacon_interval) {
1039 			*chan = wdev->chandef.chan;
1040 			*chanmode = CHAN_MODE_SHARED;
1041 
1042 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1043 							    &wdev->chandef,
1044 							    wdev->iftype);
1045 			WARN_ON(ret < 0);
1046 			if (ret > 0)
1047 				*radar_detect |= BIT(wdev->chandef.width);
1048 		}
1049 		return;
1050 	case NL80211_IFTYPE_MESH_POINT:
1051 		if (wdev->mesh_id_len) {
1052 			*chan = wdev->chandef.chan;
1053 			*chanmode = CHAN_MODE_SHARED;
1054 
1055 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1056 							    &wdev->chandef,
1057 							    wdev->iftype);
1058 			WARN_ON(ret < 0);
1059 			if (ret > 0)
1060 				*radar_detect |= BIT(wdev->chandef.width);
1061 		}
1062 		return;
1063 	case NL80211_IFTYPE_OCB:
1064 		if (wdev->chandef.chan) {
1065 			*chan = wdev->chandef.chan;
1066 			*chanmode = CHAN_MODE_SHARED;
1067 			return;
1068 		}
1069 		break;
1070 	case NL80211_IFTYPE_MONITOR:
1071 	case NL80211_IFTYPE_AP_VLAN:
1072 	case NL80211_IFTYPE_WDS:
1073 	case NL80211_IFTYPE_P2P_DEVICE:
1074 	case NL80211_IFTYPE_NAN:
1075 		/* these interface types don't really have a channel */
1076 		return;
1077 	case NL80211_IFTYPE_UNSPECIFIED:
1078 	case NUM_NL80211_IFTYPES:
1079 		WARN_ON(1);
1080 	}
1081 }
1082