xref: /linux/net/wireless/chan.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
1 /*
2  * This file contains helper code to handle channel
3  * settings and keeping track of what is possible at
4  * any point in time.
5  *
6  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
7  * Copyright 2013-2014  Intel Mobile Communications GmbH
8  */
9 
10 #include <linux/export.h>
11 #include <net/cfg80211.h>
12 #include "core.h"
13 #include "rdev-ops.h"
14 
15 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
16 			     struct ieee80211_channel *chan,
17 			     enum nl80211_channel_type chan_type)
18 {
19 	if (WARN_ON(!chan))
20 		return;
21 
22 	chandef->chan = chan;
23 	chandef->center_freq2 = 0;
24 
25 	switch (chan_type) {
26 	case NL80211_CHAN_NO_HT:
27 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
28 		chandef->center_freq1 = chan->center_freq;
29 		break;
30 	case NL80211_CHAN_HT20:
31 		chandef->width = NL80211_CHAN_WIDTH_20;
32 		chandef->center_freq1 = chan->center_freq;
33 		break;
34 	case NL80211_CHAN_HT40PLUS:
35 		chandef->width = NL80211_CHAN_WIDTH_40;
36 		chandef->center_freq1 = chan->center_freq + 10;
37 		break;
38 	case NL80211_CHAN_HT40MINUS:
39 		chandef->width = NL80211_CHAN_WIDTH_40;
40 		chandef->center_freq1 = chan->center_freq - 10;
41 		break;
42 	default:
43 		WARN_ON(1);
44 	}
45 }
46 EXPORT_SYMBOL(cfg80211_chandef_create);
47 
48 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
49 {
50 	u32 control_freq;
51 
52 	if (!chandef->chan)
53 		return false;
54 
55 	control_freq = chandef->chan->center_freq;
56 
57 	switch (chandef->width) {
58 	case NL80211_CHAN_WIDTH_5:
59 	case NL80211_CHAN_WIDTH_10:
60 	case NL80211_CHAN_WIDTH_20:
61 	case NL80211_CHAN_WIDTH_20_NOHT:
62 		if (chandef->center_freq1 != control_freq)
63 			return false;
64 		if (chandef->center_freq2)
65 			return false;
66 		break;
67 	case NL80211_CHAN_WIDTH_40:
68 		if (chandef->center_freq1 != control_freq + 10 &&
69 		    chandef->center_freq1 != control_freq - 10)
70 			return false;
71 		if (chandef->center_freq2)
72 			return false;
73 		break;
74 	case NL80211_CHAN_WIDTH_80P80:
75 		if (chandef->center_freq1 != control_freq + 30 &&
76 		    chandef->center_freq1 != control_freq + 10 &&
77 		    chandef->center_freq1 != control_freq - 10 &&
78 		    chandef->center_freq1 != control_freq - 30)
79 			return false;
80 		if (!chandef->center_freq2)
81 			return false;
82 		/* adjacent is not allowed -- that's a 160 MHz channel */
83 		if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
84 		    chandef->center_freq2 - chandef->center_freq1 == 80)
85 			return false;
86 		break;
87 	case NL80211_CHAN_WIDTH_80:
88 		if (chandef->center_freq1 != control_freq + 30 &&
89 		    chandef->center_freq1 != control_freq + 10 &&
90 		    chandef->center_freq1 != control_freq - 10 &&
91 		    chandef->center_freq1 != control_freq - 30)
92 			return false;
93 		if (chandef->center_freq2)
94 			return false;
95 		break;
96 	case NL80211_CHAN_WIDTH_160:
97 		if (chandef->center_freq1 != control_freq + 70 &&
98 		    chandef->center_freq1 != control_freq + 50 &&
99 		    chandef->center_freq1 != control_freq + 30 &&
100 		    chandef->center_freq1 != control_freq + 10 &&
101 		    chandef->center_freq1 != control_freq - 10 &&
102 		    chandef->center_freq1 != control_freq - 30 &&
103 		    chandef->center_freq1 != control_freq - 50 &&
104 		    chandef->center_freq1 != control_freq - 70)
105 			return false;
106 		if (chandef->center_freq2)
107 			return false;
108 		break;
109 	default:
110 		return false;
111 	}
112 
113 	return true;
114 }
115 EXPORT_SYMBOL(cfg80211_chandef_valid);
116 
117 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
118 				  u32 *pri40, u32 *pri80)
119 {
120 	int tmp;
121 
122 	switch (c->width) {
123 	case NL80211_CHAN_WIDTH_40:
124 		*pri40 = c->center_freq1;
125 		*pri80 = 0;
126 		break;
127 	case NL80211_CHAN_WIDTH_80:
128 	case NL80211_CHAN_WIDTH_80P80:
129 		*pri80 = c->center_freq1;
130 		/* n_P20 */
131 		tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
132 		/* n_P40 */
133 		tmp /= 2;
134 		/* freq_P40 */
135 		*pri40 = c->center_freq1 - 20 + 40 * tmp;
136 		break;
137 	case NL80211_CHAN_WIDTH_160:
138 		/* n_P20 */
139 		tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
140 		/* n_P40 */
141 		tmp /= 2;
142 		/* freq_P40 */
143 		*pri40 = c->center_freq1 - 60 + 40 * tmp;
144 		/* n_P80 */
145 		tmp /= 2;
146 		*pri80 = c->center_freq1 - 40 + 80 * tmp;
147 		break;
148 	default:
149 		WARN_ON_ONCE(1);
150 	}
151 }
152 
153 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
154 {
155 	int width;
156 
157 	switch (c->width) {
158 	case NL80211_CHAN_WIDTH_5:
159 		width = 5;
160 		break;
161 	case NL80211_CHAN_WIDTH_10:
162 		width = 10;
163 		break;
164 	case NL80211_CHAN_WIDTH_20:
165 	case NL80211_CHAN_WIDTH_20_NOHT:
166 		width = 20;
167 		break;
168 	case NL80211_CHAN_WIDTH_40:
169 		width = 40;
170 		break;
171 	case NL80211_CHAN_WIDTH_80P80:
172 	case NL80211_CHAN_WIDTH_80:
173 		width = 80;
174 		break;
175 	case NL80211_CHAN_WIDTH_160:
176 		width = 160;
177 		break;
178 	default:
179 		WARN_ON_ONCE(1);
180 		return -1;
181 	}
182 	return width;
183 }
184 
185 const struct cfg80211_chan_def *
186 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
187 			    const struct cfg80211_chan_def *c2)
188 {
189 	u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
190 
191 	/* If they are identical, return */
192 	if (cfg80211_chandef_identical(c1, c2))
193 		return c1;
194 
195 	/* otherwise, must have same control channel */
196 	if (c1->chan != c2->chan)
197 		return NULL;
198 
199 	/*
200 	 * If they have the same width, but aren't identical,
201 	 * then they can't be compatible.
202 	 */
203 	if (c1->width == c2->width)
204 		return NULL;
205 
206 	/*
207 	 * can't be compatible if one of them is 5 or 10 MHz,
208 	 * but they don't have the same width.
209 	 */
210 	if (c1->width == NL80211_CHAN_WIDTH_5 ||
211 	    c1->width == NL80211_CHAN_WIDTH_10 ||
212 	    c2->width == NL80211_CHAN_WIDTH_5 ||
213 	    c2->width == NL80211_CHAN_WIDTH_10)
214 		return NULL;
215 
216 	if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
217 	    c1->width == NL80211_CHAN_WIDTH_20)
218 		return c2;
219 
220 	if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
221 	    c2->width == NL80211_CHAN_WIDTH_20)
222 		return c1;
223 
224 	chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
225 	chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
226 
227 	if (c1_pri40 != c2_pri40)
228 		return NULL;
229 
230 	WARN_ON(!c1_pri80 && !c2_pri80);
231 	if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
232 		return NULL;
233 
234 	if (c1->width > c2->width)
235 		return c1;
236 	return c2;
237 }
238 EXPORT_SYMBOL(cfg80211_chandef_compatible);
239 
240 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
241 					 u32 bandwidth,
242 					 enum nl80211_dfs_state dfs_state)
243 {
244 	struct ieee80211_channel *c;
245 	u32 freq;
246 
247 	for (freq = center_freq - bandwidth/2 + 10;
248 	     freq <= center_freq + bandwidth/2 - 10;
249 	     freq += 20) {
250 		c = ieee80211_get_channel(wiphy, freq);
251 		if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
252 			continue;
253 
254 		c->dfs_state = dfs_state;
255 		c->dfs_state_entered = jiffies;
256 	}
257 }
258 
259 void cfg80211_set_dfs_state(struct wiphy *wiphy,
260 			    const struct cfg80211_chan_def *chandef,
261 			    enum nl80211_dfs_state dfs_state)
262 {
263 	int width;
264 
265 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
266 		return;
267 
268 	width = cfg80211_chandef_get_width(chandef);
269 	if (width < 0)
270 		return;
271 
272 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
273 				     width, dfs_state);
274 
275 	if (!chandef->center_freq2)
276 		return;
277 	cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
278 				     width, dfs_state);
279 }
280 
281 static u32 cfg80211_get_start_freq(u32 center_freq,
282 				   u32 bandwidth)
283 {
284 	u32 start_freq;
285 
286 	if (bandwidth <= 20)
287 		start_freq = center_freq;
288 	else
289 		start_freq = center_freq - bandwidth/2 + 10;
290 
291 	return start_freq;
292 }
293 
294 static u32 cfg80211_get_end_freq(u32 center_freq,
295 				 u32 bandwidth)
296 {
297 	u32 end_freq;
298 
299 	if (bandwidth <= 20)
300 		end_freq = center_freq;
301 	else
302 		end_freq = center_freq + bandwidth/2 - 10;
303 
304 	return end_freq;
305 }
306 
307 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
308 					    u32 center_freq,
309 					    u32 bandwidth)
310 {
311 	struct ieee80211_channel *c;
312 	u32 freq, start_freq, end_freq;
313 
314 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
315 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
316 
317 	for (freq = start_freq; freq <= end_freq; freq += 20) {
318 		c = ieee80211_get_channel(wiphy, freq);
319 		if (!c)
320 			return -EINVAL;
321 
322 		if (c->flags & IEEE80211_CHAN_RADAR)
323 			return 1;
324 	}
325 	return 0;
326 }
327 
328 
329 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
330 				  const struct cfg80211_chan_def *chandef,
331 				  enum nl80211_iftype iftype)
332 {
333 	int width;
334 	int ret;
335 
336 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
337 		return -EINVAL;
338 
339 	switch (iftype) {
340 	case NL80211_IFTYPE_ADHOC:
341 	case NL80211_IFTYPE_AP:
342 	case NL80211_IFTYPE_P2P_GO:
343 	case NL80211_IFTYPE_MESH_POINT:
344 		width = cfg80211_chandef_get_width(chandef);
345 		if (width < 0)
346 			return -EINVAL;
347 
348 		ret = cfg80211_get_chans_dfs_required(wiphy,
349 						      chandef->center_freq1,
350 						      width);
351 		if (ret < 0)
352 			return ret;
353 		else if (ret > 0)
354 			return BIT(chandef->width);
355 
356 		if (!chandef->center_freq2)
357 			return 0;
358 
359 		ret = cfg80211_get_chans_dfs_required(wiphy,
360 						      chandef->center_freq2,
361 						      width);
362 		if (ret < 0)
363 			return ret;
364 		else if (ret > 0)
365 			return BIT(chandef->width);
366 
367 		break;
368 	case NL80211_IFTYPE_STATION:
369 	case NL80211_IFTYPE_OCB:
370 	case NL80211_IFTYPE_P2P_CLIENT:
371 	case NL80211_IFTYPE_MONITOR:
372 	case NL80211_IFTYPE_AP_VLAN:
373 	case NL80211_IFTYPE_WDS:
374 	case NL80211_IFTYPE_P2P_DEVICE:
375 	case NL80211_IFTYPE_NAN:
376 		break;
377 	case NL80211_IFTYPE_UNSPECIFIED:
378 	case NUM_NL80211_IFTYPES:
379 		WARN_ON(1);
380 	}
381 
382 	return 0;
383 }
384 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
385 
386 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
387 					 u32 center_freq,
388 					 u32 bandwidth)
389 {
390 	struct ieee80211_channel *c;
391 	u32 freq, start_freq, end_freq;
392 	int count = 0;
393 
394 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
395 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
396 
397 	/*
398 	 * Check entire range of channels for the bandwidth.
399 	 * Check all channels are DFS channels (DFS_USABLE or
400 	 * DFS_AVAILABLE). Return number of usable channels
401 	 * (require CAC). Allow DFS and non-DFS channel mix.
402 	 */
403 	for (freq = start_freq; freq <= end_freq; freq += 20) {
404 		c = ieee80211_get_channel(wiphy, freq);
405 		if (!c)
406 			return -EINVAL;
407 
408 		if (c->flags & IEEE80211_CHAN_DISABLED)
409 			return -EINVAL;
410 
411 		if (c->flags & IEEE80211_CHAN_RADAR) {
412 			if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
413 				return -EINVAL;
414 
415 			if (c->dfs_state == NL80211_DFS_USABLE)
416 				count++;
417 		}
418 	}
419 
420 	return count;
421 }
422 
423 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
424 				 const struct cfg80211_chan_def *chandef)
425 {
426 	int width;
427 	int r1, r2 = 0;
428 
429 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
430 		return false;
431 
432 	width = cfg80211_chandef_get_width(chandef);
433 	if (width < 0)
434 		return false;
435 
436 	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
437 					  width);
438 
439 	if (r1 < 0)
440 		return false;
441 
442 	switch (chandef->width) {
443 	case NL80211_CHAN_WIDTH_80P80:
444 		WARN_ON(!chandef->center_freq2);
445 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
446 						   chandef->center_freq2,
447 						   width);
448 		if (r2 < 0)
449 			return false;
450 		break;
451 	default:
452 		WARN_ON(chandef->center_freq2);
453 		break;
454 	}
455 
456 	return (r1 + r2 > 0);
457 }
458 
459 /*
460  * Checks if center frequency of chan falls with in the bandwidth
461  * range of chandef.
462  */
463 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
464 			  struct ieee80211_channel *chan)
465 {
466 	int width;
467 	u32 cf_offset, freq;
468 
469 	if (chandef->chan->center_freq == chan->center_freq)
470 		return true;
471 
472 	width = cfg80211_chandef_get_width(chandef);
473 	if (width <= 20)
474 		return false;
475 
476 	cf_offset = width / 2 - 10;
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 
584 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
585 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
586 
587 	/*
588 	 * Check entire range of channels for the bandwidth.
589 	 * If any channel in between is disabled or has not
590 	 * had gone through CAC return false
591 	 */
592 	for (freq = start_freq; freq <= end_freq; freq += 20) {
593 		c = ieee80211_get_channel(wiphy, freq);
594 		if (!c)
595 			return false;
596 
597 		if (c->flags & IEEE80211_CHAN_DISABLED)
598 			return false;
599 
600 		if ((c->flags & IEEE80211_CHAN_RADAR)  &&
601 		    (c->dfs_state != NL80211_DFS_AVAILABLE))
602 			return false;
603 	}
604 
605 	return true;
606 }
607 
608 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
609 				const struct cfg80211_chan_def *chandef)
610 {
611 	int width;
612 	int r;
613 
614 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
615 		return false;
616 
617 	width = cfg80211_chandef_get_width(chandef);
618 	if (width < 0)
619 		return false;
620 
621 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
622 					     width);
623 
624 	/* If any of channels unavailable for cf1 just return */
625 	if (!r)
626 		return r;
627 
628 	switch (chandef->width) {
629 	case NL80211_CHAN_WIDTH_80P80:
630 		WARN_ON(!chandef->center_freq2);
631 		r = cfg80211_get_chans_dfs_available(wiphy,
632 						     chandef->center_freq2,
633 						     width);
634 		break;
635 	default:
636 		WARN_ON(chandef->center_freq2);
637 		break;
638 	}
639 
640 	return r;
641 }
642 
643 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
644 						    u32 center_freq,
645 						    u32 bandwidth)
646 {
647 	struct ieee80211_channel *c;
648 	u32 start_freq, end_freq, freq;
649 	unsigned int dfs_cac_ms = 0;
650 
651 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
652 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
653 
654 	for (freq = start_freq; freq <= end_freq; freq += 20) {
655 		c = ieee80211_get_channel(wiphy, freq);
656 		if (!c)
657 			return 0;
658 
659 		if (c->flags & IEEE80211_CHAN_DISABLED)
660 			return 0;
661 
662 		if (!(c->flags & IEEE80211_CHAN_RADAR))
663 			continue;
664 
665 		if (c->dfs_cac_ms > dfs_cac_ms)
666 			dfs_cac_ms = c->dfs_cac_ms;
667 	}
668 
669 	return dfs_cac_ms;
670 }
671 
672 unsigned int
673 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
674 			      const struct cfg80211_chan_def *chandef)
675 {
676 	int width;
677 	unsigned int t1 = 0, t2 = 0;
678 
679 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
680 		return 0;
681 
682 	width = cfg80211_chandef_get_width(chandef);
683 	if (width < 0)
684 		return 0;
685 
686 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
687 					     chandef->center_freq1,
688 					     width);
689 
690 	if (!chandef->center_freq2)
691 		return t1;
692 
693 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
694 					     chandef->center_freq2,
695 					     width);
696 
697 	return max(t1, t2);
698 }
699 
700 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
701 					u32 center_freq, u32 bandwidth,
702 					u32 prohibited_flags)
703 {
704 	struct ieee80211_channel *c;
705 	u32 freq, start_freq, end_freq;
706 
707 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
708 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
709 
710 	for (freq = start_freq; freq <= end_freq; freq += 20) {
711 		c = ieee80211_get_channel(wiphy, freq);
712 		if (!c || c->flags & prohibited_flags)
713 			return false;
714 	}
715 
716 	return true;
717 }
718 
719 bool cfg80211_chandef_usable(struct wiphy *wiphy,
720 			     const struct cfg80211_chan_def *chandef,
721 			     u32 prohibited_flags)
722 {
723 	struct ieee80211_sta_ht_cap *ht_cap;
724 	struct ieee80211_sta_vht_cap *vht_cap;
725 	u32 width, control_freq, cap;
726 
727 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
728 		return false;
729 
730 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
731 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
732 
733 	control_freq = chandef->chan->center_freq;
734 
735 	switch (chandef->width) {
736 	case NL80211_CHAN_WIDTH_5:
737 		width = 5;
738 		break;
739 	case NL80211_CHAN_WIDTH_10:
740 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
741 		width = 10;
742 		break;
743 	case NL80211_CHAN_WIDTH_20:
744 		if (!ht_cap->ht_supported)
745 			return false;
746 	case NL80211_CHAN_WIDTH_20_NOHT:
747 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
748 		width = 20;
749 		break;
750 	case NL80211_CHAN_WIDTH_40:
751 		width = 40;
752 		if (!ht_cap->ht_supported)
753 			return false;
754 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
755 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
756 			return false;
757 		if (chandef->center_freq1 < control_freq &&
758 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
759 			return false;
760 		if (chandef->center_freq1 > control_freq &&
761 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
762 			return false;
763 		break;
764 	case NL80211_CHAN_WIDTH_80P80:
765 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
766 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
767 			return false;
768 	case NL80211_CHAN_WIDTH_80:
769 		if (!vht_cap->vht_supported)
770 			return false;
771 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
772 		width = 80;
773 		break;
774 	case NL80211_CHAN_WIDTH_160:
775 		if (!vht_cap->vht_supported)
776 			return false;
777 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
778 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
779 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
780 			return false;
781 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
782 		width = 160;
783 		break;
784 	default:
785 		WARN_ON_ONCE(1);
786 		return false;
787 	}
788 
789 	/*
790 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
791 	 *	 allowed by the driver, or only certain combinations?
792 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
793 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
794 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
795 	 *	 no way to cover 80+80 MHz or more complex restrictions.
796 	 *	 Note that such restrictions also need to be advertised to
797 	 *	 userspace, for example for P2P channel selection.
798 	 */
799 
800 	if (width > 20)
801 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
802 
803 	/* 5 and 10 MHz are only defined for the OFDM PHY */
804 	if (width < 20)
805 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
806 
807 
808 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
809 					 width, prohibited_flags))
810 		return false;
811 
812 	if (!chandef->center_freq2)
813 		return true;
814 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
815 					   width, prohibited_flags);
816 }
817 EXPORT_SYMBOL(cfg80211_chandef_usable);
818 
819 /*
820  * Check if the channel can be used under permissive conditions mandated by
821  * some regulatory bodies, i.e., the channel is marked with
822  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
823  * associated to an AP on the same channel or on the same UNII band
824  * (assuming that the AP is an authorized master).
825  * In addition allow operation on a channel on which indoor operation is
826  * allowed, iff we are currently operating in an indoor environment.
827  */
828 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
829 					enum nl80211_iftype iftype,
830 					struct ieee80211_channel *chan)
831 {
832 	struct wireless_dev *wdev;
833 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
834 
835 	ASSERT_RTNL();
836 
837 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
838 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
839 		return false;
840 
841 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
842 	if (iftype != NL80211_IFTYPE_P2P_GO &&
843 	    iftype != NL80211_IFTYPE_STATION &&
844 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
845 		return false;
846 
847 	if (regulatory_indoor_allowed() &&
848 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
849 		return true;
850 
851 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
852 		return false;
853 
854 	/*
855 	 * Generally, it is possible to rely on another device/driver to allow
856 	 * the IR concurrent relaxation, however, since the device can further
857 	 * enforce the relaxation (by doing a similar verifications as this),
858 	 * and thus fail the GO instantiation, consider only the interfaces of
859 	 * the current registered device.
860 	 */
861 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
862 		struct ieee80211_channel *other_chan = NULL;
863 		int r1, r2;
864 
865 		wdev_lock(wdev);
866 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
867 		    wdev->current_bss)
868 			other_chan = wdev->current_bss->pub.channel;
869 
870 		/*
871 		 * If a GO already operates on the same GO_CONCURRENT channel,
872 		 * this one (maybe the same one) can beacon as well. We allow
873 		 * the operation even if the station we relied on with
874 		 * GO_CONCURRENT is disconnected now. But then we must make sure
875 		 * we're not outdoor on an indoor-only channel.
876 		 */
877 		if (iftype == NL80211_IFTYPE_P2P_GO &&
878 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
879 		    wdev->beacon_interval &&
880 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
881 			other_chan = wdev->chandef.chan;
882 		wdev_unlock(wdev);
883 
884 		if (!other_chan)
885 			continue;
886 
887 		if (chan == other_chan)
888 			return true;
889 
890 		if (chan->band != NL80211_BAND_5GHZ)
891 			continue;
892 
893 		r1 = cfg80211_get_unii(chan->center_freq);
894 		r2 = cfg80211_get_unii(other_chan->center_freq);
895 
896 		if (r1 != -EINVAL && r1 == r2) {
897 			/*
898 			 * At some locations channels 149-165 are considered a
899 			 * bundle, but at other locations, e.g., Indonesia,
900 			 * channels 149-161 are considered a bundle while
901 			 * channel 165 is left out and considered to be in a
902 			 * different bundle. Thus, in case that there is a
903 			 * station interface connected to an AP on channel 165,
904 			 * it is assumed that channels 149-161 are allowed for
905 			 * GO operations. However, having a station interface
906 			 * connected to an AP on channels 149-161, does not
907 			 * allow GO operation on channel 165.
908 			 */
909 			if (chan->center_freq == 5825 &&
910 			    other_chan->center_freq != 5825)
911 				continue;
912 			return true;
913 		}
914 	}
915 
916 	return false;
917 }
918 
919 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
920 				     struct cfg80211_chan_def *chandef,
921 				     enum nl80211_iftype iftype,
922 				     bool check_no_ir)
923 {
924 	bool res;
925 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
926 			       IEEE80211_CHAN_RADAR;
927 
928 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
929 
930 	if (check_no_ir)
931 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
932 
933 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
934 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
935 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
936 		prohibited_flags = IEEE80211_CHAN_DISABLED;
937 	}
938 
939 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
940 
941 	trace_cfg80211_return_bool(res);
942 	return res;
943 }
944 
945 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
946 			     struct cfg80211_chan_def *chandef,
947 			     enum nl80211_iftype iftype)
948 {
949 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
950 }
951 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
952 
953 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
954 				   struct cfg80211_chan_def *chandef,
955 				   enum nl80211_iftype iftype)
956 {
957 	bool check_no_ir;
958 
959 	ASSERT_RTNL();
960 
961 	/*
962 	 * Under certain conditions suggested by some regulatory bodies a
963 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
964 	 * only if such relaxations are not enabled and the conditions are not
965 	 * met.
966 	 */
967 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
968 						   chandef->chan);
969 
970 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
971 }
972 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
973 
974 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
975 				 struct cfg80211_chan_def *chandef)
976 {
977 	if (!rdev->ops->set_monitor_channel)
978 		return -EOPNOTSUPP;
979 	if (!cfg80211_has_monitors_only(rdev))
980 		return -EBUSY;
981 
982 	return rdev_set_monitor_channel(rdev, chandef);
983 }
984 
985 void
986 cfg80211_get_chan_state(struct wireless_dev *wdev,
987 		        struct ieee80211_channel **chan,
988 		        enum cfg80211_chan_mode *chanmode,
989 		        u8 *radar_detect)
990 {
991 	int ret;
992 
993 	*chan = NULL;
994 	*chanmode = CHAN_MODE_UNDEFINED;
995 
996 	ASSERT_WDEV_LOCK(wdev);
997 
998 	if (wdev->netdev && !netif_running(wdev->netdev))
999 		return;
1000 
1001 	switch (wdev->iftype) {
1002 	case NL80211_IFTYPE_ADHOC:
1003 		if (wdev->current_bss) {
1004 			*chan = wdev->current_bss->pub.channel;
1005 			*chanmode = (wdev->ibss_fixed &&
1006 				     !wdev->ibss_dfs_possible)
1007 				  ? CHAN_MODE_SHARED
1008 				  : CHAN_MODE_EXCLUSIVE;
1009 
1010 			/* consider worst-case - IBSS can try to return to the
1011 			 * original user-specified channel as creator */
1012 			if (wdev->ibss_dfs_possible)
1013 				*radar_detect |= BIT(wdev->chandef.width);
1014 			return;
1015 		}
1016 		break;
1017 	case NL80211_IFTYPE_STATION:
1018 	case NL80211_IFTYPE_P2P_CLIENT:
1019 		if (wdev->current_bss) {
1020 			*chan = wdev->current_bss->pub.channel;
1021 			*chanmode = CHAN_MODE_SHARED;
1022 			return;
1023 		}
1024 		break;
1025 	case NL80211_IFTYPE_AP:
1026 	case NL80211_IFTYPE_P2P_GO:
1027 		if (wdev->cac_started) {
1028 			*chan = wdev->chandef.chan;
1029 			*chanmode = CHAN_MODE_SHARED;
1030 			*radar_detect |= BIT(wdev->chandef.width);
1031 		} else if (wdev->beacon_interval) {
1032 			*chan = wdev->chandef.chan;
1033 			*chanmode = CHAN_MODE_SHARED;
1034 
1035 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1036 							    &wdev->chandef,
1037 							    wdev->iftype);
1038 			WARN_ON(ret < 0);
1039 			if (ret > 0)
1040 				*radar_detect |= BIT(wdev->chandef.width);
1041 		}
1042 		return;
1043 	case NL80211_IFTYPE_MESH_POINT:
1044 		if (wdev->mesh_id_len) {
1045 			*chan = wdev->chandef.chan;
1046 			*chanmode = CHAN_MODE_SHARED;
1047 
1048 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1049 							    &wdev->chandef,
1050 							    wdev->iftype);
1051 			WARN_ON(ret < 0);
1052 			if (ret > 0)
1053 				*radar_detect |= BIT(wdev->chandef.width);
1054 		}
1055 		return;
1056 	case NL80211_IFTYPE_OCB:
1057 		if (wdev->chandef.chan) {
1058 			*chan = wdev->chandef.chan;
1059 			*chanmode = CHAN_MODE_SHARED;
1060 			return;
1061 		}
1062 		break;
1063 	case NL80211_IFTYPE_MONITOR:
1064 	case NL80211_IFTYPE_AP_VLAN:
1065 	case NL80211_IFTYPE_WDS:
1066 	case NL80211_IFTYPE_P2P_DEVICE:
1067 	case NL80211_IFTYPE_NAN:
1068 		/* these interface types don't really have a channel */
1069 		return;
1070 	case NL80211_IFTYPE_UNSPECIFIED:
1071 	case NUM_NL80211_IFTYPES:
1072 		WARN_ON(1);
1073 	}
1074 }
1075