xref: /openbmc/linux/net/wireless/chan.c (revision 6d99a79c)
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 	bool dfs_offload;
583 
584 	dfs_offload = wiphy_ext_feature_isset(wiphy,
585 					      NL80211_EXT_FEATURE_DFS_OFFLOAD);
586 
587 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
588 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
589 
590 	/*
591 	 * Check entire range of channels for the bandwidth.
592 	 * If any channel in between is disabled or has not
593 	 * had gone through CAC return false
594 	 */
595 	for (freq = start_freq; freq <= end_freq; freq += 20) {
596 		c = ieee80211_get_channel(wiphy, freq);
597 		if (!c)
598 			return false;
599 
600 		if (c->flags & IEEE80211_CHAN_DISABLED)
601 			return false;
602 
603 		if ((c->flags & IEEE80211_CHAN_RADAR) &&
604 		    (c->dfs_state != NL80211_DFS_AVAILABLE) &&
605 		    !(c->dfs_state == NL80211_DFS_USABLE && dfs_offload))
606 			return false;
607 	}
608 
609 	return true;
610 }
611 
612 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
613 				const struct cfg80211_chan_def *chandef)
614 {
615 	int width;
616 	int r;
617 
618 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
619 		return false;
620 
621 	width = cfg80211_chandef_get_width(chandef);
622 	if (width < 0)
623 		return false;
624 
625 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
626 					     width);
627 
628 	/* If any of channels unavailable for cf1 just return */
629 	if (!r)
630 		return r;
631 
632 	switch (chandef->width) {
633 	case NL80211_CHAN_WIDTH_80P80:
634 		WARN_ON(!chandef->center_freq2);
635 		r = cfg80211_get_chans_dfs_available(wiphy,
636 						     chandef->center_freq2,
637 						     width);
638 		break;
639 	default:
640 		WARN_ON(chandef->center_freq2);
641 		break;
642 	}
643 
644 	return r;
645 }
646 
647 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
648 						    u32 center_freq,
649 						    u32 bandwidth)
650 {
651 	struct ieee80211_channel *c;
652 	u32 start_freq, end_freq, freq;
653 	unsigned int dfs_cac_ms = 0;
654 
655 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
656 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
657 
658 	for (freq = start_freq; freq <= end_freq; freq += 20) {
659 		c = ieee80211_get_channel(wiphy, freq);
660 		if (!c)
661 			return 0;
662 
663 		if (c->flags & IEEE80211_CHAN_DISABLED)
664 			return 0;
665 
666 		if (!(c->flags & IEEE80211_CHAN_RADAR))
667 			continue;
668 
669 		if (c->dfs_cac_ms > dfs_cac_ms)
670 			dfs_cac_ms = c->dfs_cac_ms;
671 	}
672 
673 	return dfs_cac_ms;
674 }
675 
676 unsigned int
677 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
678 			      const struct cfg80211_chan_def *chandef)
679 {
680 	int width;
681 	unsigned int t1 = 0, t2 = 0;
682 
683 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
684 		return 0;
685 
686 	width = cfg80211_chandef_get_width(chandef);
687 	if (width < 0)
688 		return 0;
689 
690 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
691 					     chandef->center_freq1,
692 					     width);
693 
694 	if (!chandef->center_freq2)
695 		return t1;
696 
697 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
698 					     chandef->center_freq2,
699 					     width);
700 
701 	return max(t1, t2);
702 }
703 
704 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
705 					u32 center_freq, u32 bandwidth,
706 					u32 prohibited_flags)
707 {
708 	struct ieee80211_channel *c;
709 	u32 freq, start_freq, end_freq;
710 
711 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
712 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
713 
714 	for (freq = start_freq; freq <= end_freq; freq += 20) {
715 		c = ieee80211_get_channel(wiphy, freq);
716 		if (!c || c->flags & prohibited_flags)
717 			return false;
718 	}
719 
720 	return true;
721 }
722 
723 bool cfg80211_chandef_usable(struct wiphy *wiphy,
724 			     const struct cfg80211_chan_def *chandef,
725 			     u32 prohibited_flags)
726 {
727 	struct ieee80211_sta_ht_cap *ht_cap;
728 	struct ieee80211_sta_vht_cap *vht_cap;
729 	u32 width, control_freq, cap;
730 
731 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
732 		return false;
733 
734 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
735 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
736 
737 	control_freq = chandef->chan->center_freq;
738 
739 	switch (chandef->width) {
740 	case NL80211_CHAN_WIDTH_5:
741 		width = 5;
742 		break;
743 	case NL80211_CHAN_WIDTH_10:
744 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
745 		width = 10;
746 		break;
747 	case NL80211_CHAN_WIDTH_20:
748 		if (!ht_cap->ht_supported)
749 			return false;
750 	case NL80211_CHAN_WIDTH_20_NOHT:
751 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
752 		width = 20;
753 		break;
754 	case NL80211_CHAN_WIDTH_40:
755 		width = 40;
756 		if (!ht_cap->ht_supported)
757 			return false;
758 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
759 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
760 			return false;
761 		if (chandef->center_freq1 < control_freq &&
762 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
763 			return false;
764 		if (chandef->center_freq1 > control_freq &&
765 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
766 			return false;
767 		break;
768 	case NL80211_CHAN_WIDTH_80P80:
769 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
770 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
771 			return false;
772 	case NL80211_CHAN_WIDTH_80:
773 		if (!vht_cap->vht_supported)
774 			return false;
775 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
776 		width = 80;
777 		break;
778 	case NL80211_CHAN_WIDTH_160:
779 		if (!vht_cap->vht_supported)
780 			return false;
781 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
782 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
783 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
784 			return false;
785 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
786 		width = 160;
787 		break;
788 	default:
789 		WARN_ON_ONCE(1);
790 		return false;
791 	}
792 
793 	/*
794 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
795 	 *	 allowed by the driver, or only certain combinations?
796 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
797 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
798 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
799 	 *	 no way to cover 80+80 MHz or more complex restrictions.
800 	 *	 Note that such restrictions also need to be advertised to
801 	 *	 userspace, for example for P2P channel selection.
802 	 */
803 
804 	if (width > 20)
805 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
806 
807 	/* 5 and 10 MHz are only defined for the OFDM PHY */
808 	if (width < 20)
809 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
810 
811 
812 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
813 					 width, prohibited_flags))
814 		return false;
815 
816 	if (!chandef->center_freq2)
817 		return true;
818 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
819 					   width, prohibited_flags);
820 }
821 EXPORT_SYMBOL(cfg80211_chandef_usable);
822 
823 /*
824  * Check if the channel can be used under permissive conditions mandated by
825  * some regulatory bodies, i.e., the channel is marked with
826  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
827  * associated to an AP on the same channel or on the same UNII band
828  * (assuming that the AP is an authorized master).
829  * In addition allow operation on a channel on which indoor operation is
830  * allowed, iff we are currently operating in an indoor environment.
831  */
832 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
833 					enum nl80211_iftype iftype,
834 					struct ieee80211_channel *chan)
835 {
836 	struct wireless_dev *wdev;
837 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
838 
839 	ASSERT_RTNL();
840 
841 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
842 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
843 		return false;
844 
845 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
846 	if (iftype != NL80211_IFTYPE_P2P_GO &&
847 	    iftype != NL80211_IFTYPE_STATION &&
848 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
849 		return false;
850 
851 	if (regulatory_indoor_allowed() &&
852 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
853 		return true;
854 
855 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
856 		return false;
857 
858 	/*
859 	 * Generally, it is possible to rely on another device/driver to allow
860 	 * the IR concurrent relaxation, however, since the device can further
861 	 * enforce the relaxation (by doing a similar verifications as this),
862 	 * and thus fail the GO instantiation, consider only the interfaces of
863 	 * the current registered device.
864 	 */
865 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
866 		struct ieee80211_channel *other_chan = NULL;
867 		int r1, r2;
868 
869 		wdev_lock(wdev);
870 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
871 		    wdev->current_bss)
872 			other_chan = wdev->current_bss->pub.channel;
873 
874 		/*
875 		 * If a GO already operates on the same GO_CONCURRENT channel,
876 		 * this one (maybe the same one) can beacon as well. We allow
877 		 * the operation even if the station we relied on with
878 		 * GO_CONCURRENT is disconnected now. But then we must make sure
879 		 * we're not outdoor on an indoor-only channel.
880 		 */
881 		if (iftype == NL80211_IFTYPE_P2P_GO &&
882 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
883 		    wdev->beacon_interval &&
884 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
885 			other_chan = wdev->chandef.chan;
886 		wdev_unlock(wdev);
887 
888 		if (!other_chan)
889 			continue;
890 
891 		if (chan == other_chan)
892 			return true;
893 
894 		if (chan->band != NL80211_BAND_5GHZ)
895 			continue;
896 
897 		r1 = cfg80211_get_unii(chan->center_freq);
898 		r2 = cfg80211_get_unii(other_chan->center_freq);
899 
900 		if (r1 != -EINVAL && r1 == r2) {
901 			/*
902 			 * At some locations channels 149-165 are considered a
903 			 * bundle, but at other locations, e.g., Indonesia,
904 			 * channels 149-161 are considered a bundle while
905 			 * channel 165 is left out and considered to be in a
906 			 * different bundle. Thus, in case that there is a
907 			 * station interface connected to an AP on channel 165,
908 			 * it is assumed that channels 149-161 are allowed for
909 			 * GO operations. However, having a station interface
910 			 * connected to an AP on channels 149-161, does not
911 			 * allow GO operation on channel 165.
912 			 */
913 			if (chan->center_freq == 5825 &&
914 			    other_chan->center_freq != 5825)
915 				continue;
916 			return true;
917 		}
918 	}
919 
920 	return false;
921 }
922 
923 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
924 				     struct cfg80211_chan_def *chandef,
925 				     enum nl80211_iftype iftype,
926 				     bool check_no_ir)
927 {
928 	bool res;
929 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
930 			       IEEE80211_CHAN_RADAR;
931 
932 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
933 
934 	if (check_no_ir)
935 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
936 
937 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
938 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
939 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
940 		prohibited_flags = IEEE80211_CHAN_DISABLED;
941 	}
942 
943 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
944 
945 	trace_cfg80211_return_bool(res);
946 	return res;
947 }
948 
949 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
950 			     struct cfg80211_chan_def *chandef,
951 			     enum nl80211_iftype iftype)
952 {
953 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
954 }
955 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
956 
957 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
958 				   struct cfg80211_chan_def *chandef,
959 				   enum nl80211_iftype iftype)
960 {
961 	bool check_no_ir;
962 
963 	ASSERT_RTNL();
964 
965 	/*
966 	 * Under certain conditions suggested by some regulatory bodies a
967 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
968 	 * only if such relaxations are not enabled and the conditions are not
969 	 * met.
970 	 */
971 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
972 						   chandef->chan);
973 
974 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
975 }
976 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
977 
978 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
979 				 struct cfg80211_chan_def *chandef)
980 {
981 	if (!rdev->ops->set_monitor_channel)
982 		return -EOPNOTSUPP;
983 	if (!cfg80211_has_monitors_only(rdev))
984 		return -EBUSY;
985 
986 	return rdev_set_monitor_channel(rdev, chandef);
987 }
988 
989 void
990 cfg80211_get_chan_state(struct wireless_dev *wdev,
991 		        struct ieee80211_channel **chan,
992 		        enum cfg80211_chan_mode *chanmode,
993 		        u8 *radar_detect)
994 {
995 	int ret;
996 
997 	*chan = NULL;
998 	*chanmode = CHAN_MODE_UNDEFINED;
999 
1000 	ASSERT_WDEV_LOCK(wdev);
1001 
1002 	if (wdev->netdev && !netif_running(wdev->netdev))
1003 		return;
1004 
1005 	switch (wdev->iftype) {
1006 	case NL80211_IFTYPE_ADHOC:
1007 		if (wdev->current_bss) {
1008 			*chan = wdev->current_bss->pub.channel;
1009 			*chanmode = (wdev->ibss_fixed &&
1010 				     !wdev->ibss_dfs_possible)
1011 				  ? CHAN_MODE_SHARED
1012 				  : CHAN_MODE_EXCLUSIVE;
1013 
1014 			/* consider worst-case - IBSS can try to return to the
1015 			 * original user-specified channel as creator */
1016 			if (wdev->ibss_dfs_possible)
1017 				*radar_detect |= BIT(wdev->chandef.width);
1018 			return;
1019 		}
1020 		break;
1021 	case NL80211_IFTYPE_STATION:
1022 	case NL80211_IFTYPE_P2P_CLIENT:
1023 		if (wdev->current_bss) {
1024 			*chan = wdev->current_bss->pub.channel;
1025 			*chanmode = CHAN_MODE_SHARED;
1026 			return;
1027 		}
1028 		break;
1029 	case NL80211_IFTYPE_AP:
1030 	case NL80211_IFTYPE_P2P_GO:
1031 		if (wdev->cac_started) {
1032 			*chan = wdev->chandef.chan;
1033 			*chanmode = CHAN_MODE_SHARED;
1034 			*radar_detect |= BIT(wdev->chandef.width);
1035 		} else if (wdev->beacon_interval) {
1036 			*chan = wdev->chandef.chan;
1037 			*chanmode = CHAN_MODE_SHARED;
1038 
1039 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1040 							    &wdev->chandef,
1041 							    wdev->iftype);
1042 			WARN_ON(ret < 0);
1043 			if (ret > 0)
1044 				*radar_detect |= BIT(wdev->chandef.width);
1045 		}
1046 		return;
1047 	case NL80211_IFTYPE_MESH_POINT:
1048 		if (wdev->mesh_id_len) {
1049 			*chan = wdev->chandef.chan;
1050 			*chanmode = CHAN_MODE_SHARED;
1051 
1052 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1053 							    &wdev->chandef,
1054 							    wdev->iftype);
1055 			WARN_ON(ret < 0);
1056 			if (ret > 0)
1057 				*radar_detect |= BIT(wdev->chandef.width);
1058 		}
1059 		return;
1060 	case NL80211_IFTYPE_OCB:
1061 		if (wdev->chandef.chan) {
1062 			*chan = wdev->chandef.chan;
1063 			*chanmode = CHAN_MODE_SHARED;
1064 			return;
1065 		}
1066 		break;
1067 	case NL80211_IFTYPE_MONITOR:
1068 	case NL80211_IFTYPE_AP_VLAN:
1069 	case NL80211_IFTYPE_WDS:
1070 	case NL80211_IFTYPE_P2P_DEVICE:
1071 	case NL80211_IFTYPE_NAN:
1072 		/* these interface types don't really have a channel */
1073 		return;
1074 	case NL80211_IFTYPE_UNSPECIFIED:
1075 	case NUM_NL80211_IFTYPES:
1076 		WARN_ON(1);
1077 	}
1078 }
1079