xref: /openbmc/linux/net/wireless/chan.c (revision 7587eb18)
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 		break;
376 	case NL80211_IFTYPE_UNSPECIFIED:
377 	case NUM_NL80211_IFTYPES:
378 		WARN_ON(1);
379 	}
380 
381 	return 0;
382 }
383 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
384 
385 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
386 					 u32 center_freq,
387 					 u32 bandwidth)
388 {
389 	struct ieee80211_channel *c;
390 	u32 freq, start_freq, end_freq;
391 	int count = 0;
392 
393 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
394 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
395 
396 	/*
397 	 * Check entire range of channels for the bandwidth.
398 	 * Check all channels are DFS channels (DFS_USABLE or
399 	 * DFS_AVAILABLE). Return number of usable channels
400 	 * (require CAC). Allow DFS and non-DFS channel mix.
401 	 */
402 	for (freq = start_freq; freq <= end_freq; freq += 20) {
403 		c = ieee80211_get_channel(wiphy, freq);
404 		if (!c)
405 			return -EINVAL;
406 
407 		if (c->flags & IEEE80211_CHAN_DISABLED)
408 			return -EINVAL;
409 
410 		if (c->flags & IEEE80211_CHAN_RADAR) {
411 			if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
412 				return -EINVAL;
413 
414 			if (c->dfs_state == NL80211_DFS_USABLE)
415 				count++;
416 		}
417 	}
418 
419 	return count;
420 }
421 
422 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
423 				 const struct cfg80211_chan_def *chandef)
424 {
425 	int width;
426 	int r1, r2 = 0;
427 
428 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
429 		return false;
430 
431 	width = cfg80211_chandef_get_width(chandef);
432 	if (width < 0)
433 		return false;
434 
435 	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
436 					  width);
437 
438 	if (r1 < 0)
439 		return false;
440 
441 	switch (chandef->width) {
442 	case NL80211_CHAN_WIDTH_80P80:
443 		WARN_ON(!chandef->center_freq2);
444 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
445 						   chandef->center_freq2,
446 						   width);
447 		if (r2 < 0)
448 			return false;
449 		break;
450 	default:
451 		WARN_ON(chandef->center_freq2);
452 		break;
453 	}
454 
455 	return (r1 + r2 > 0);
456 }
457 
458 
459 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
460 					     u32 center_freq,
461 					     u32 bandwidth)
462 {
463 	struct ieee80211_channel *c;
464 	u32 freq, start_freq, end_freq;
465 
466 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
467 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
468 
469 	/*
470 	 * Check entire range of channels for the bandwidth.
471 	 * If any channel in between is disabled or has not
472 	 * had gone through CAC return false
473 	 */
474 	for (freq = start_freq; freq <= end_freq; freq += 20) {
475 		c = ieee80211_get_channel(wiphy, freq);
476 		if (!c)
477 			return false;
478 
479 		if (c->flags & IEEE80211_CHAN_DISABLED)
480 			return false;
481 
482 		if ((c->flags & IEEE80211_CHAN_RADAR)  &&
483 		    (c->dfs_state != NL80211_DFS_AVAILABLE))
484 			return false;
485 	}
486 
487 	return true;
488 }
489 
490 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
491 				const struct cfg80211_chan_def *chandef)
492 {
493 	int width;
494 	int r;
495 
496 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
497 		return false;
498 
499 	width = cfg80211_chandef_get_width(chandef);
500 	if (width < 0)
501 		return false;
502 
503 	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
504 					     width);
505 
506 	/* If any of channels unavailable for cf1 just return */
507 	if (!r)
508 		return r;
509 
510 	switch (chandef->width) {
511 	case NL80211_CHAN_WIDTH_80P80:
512 		WARN_ON(!chandef->center_freq2);
513 		r = cfg80211_get_chans_dfs_available(wiphy,
514 						     chandef->center_freq2,
515 						     width);
516 	default:
517 		WARN_ON(chandef->center_freq2);
518 		break;
519 	}
520 
521 	return r;
522 }
523 
524 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
525 						    u32 center_freq,
526 						    u32 bandwidth)
527 {
528 	struct ieee80211_channel *c;
529 	u32 start_freq, end_freq, freq;
530 	unsigned int dfs_cac_ms = 0;
531 
532 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
533 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
534 
535 	for (freq = start_freq; freq <= end_freq; freq += 20) {
536 		c = ieee80211_get_channel(wiphy, freq);
537 		if (!c)
538 			return 0;
539 
540 		if (c->flags & IEEE80211_CHAN_DISABLED)
541 			return 0;
542 
543 		if (!(c->flags & IEEE80211_CHAN_RADAR))
544 			continue;
545 
546 		if (c->dfs_cac_ms > dfs_cac_ms)
547 			dfs_cac_ms = c->dfs_cac_ms;
548 	}
549 
550 	return dfs_cac_ms;
551 }
552 
553 unsigned int
554 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
555 			      const struct cfg80211_chan_def *chandef)
556 {
557 	int width;
558 	unsigned int t1 = 0, t2 = 0;
559 
560 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
561 		return 0;
562 
563 	width = cfg80211_chandef_get_width(chandef);
564 	if (width < 0)
565 		return 0;
566 
567 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
568 					     chandef->center_freq1,
569 					     width);
570 
571 	if (!chandef->center_freq2)
572 		return t1;
573 
574 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
575 					     chandef->center_freq2,
576 					     width);
577 
578 	return max(t1, t2);
579 }
580 
581 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
582 					u32 center_freq, u32 bandwidth,
583 					u32 prohibited_flags)
584 {
585 	struct ieee80211_channel *c;
586 	u32 freq, start_freq, end_freq;
587 
588 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
589 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
590 
591 	for (freq = start_freq; freq <= end_freq; freq += 20) {
592 		c = ieee80211_get_channel(wiphy, freq);
593 		if (!c || c->flags & prohibited_flags)
594 			return false;
595 	}
596 
597 	return true;
598 }
599 
600 bool cfg80211_chandef_usable(struct wiphy *wiphy,
601 			     const struct cfg80211_chan_def *chandef,
602 			     u32 prohibited_flags)
603 {
604 	struct ieee80211_sta_ht_cap *ht_cap;
605 	struct ieee80211_sta_vht_cap *vht_cap;
606 	u32 width, control_freq, cap;
607 
608 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
609 		return false;
610 
611 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
612 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
613 
614 	control_freq = chandef->chan->center_freq;
615 
616 	switch (chandef->width) {
617 	case NL80211_CHAN_WIDTH_5:
618 		width = 5;
619 		break;
620 	case NL80211_CHAN_WIDTH_10:
621 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
622 		width = 10;
623 		break;
624 	case NL80211_CHAN_WIDTH_20:
625 		if (!ht_cap->ht_supported)
626 			return false;
627 	case NL80211_CHAN_WIDTH_20_NOHT:
628 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
629 		width = 20;
630 		break;
631 	case NL80211_CHAN_WIDTH_40:
632 		width = 40;
633 		if (!ht_cap->ht_supported)
634 			return false;
635 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
636 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
637 			return false;
638 		if (chandef->center_freq1 < control_freq &&
639 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
640 			return false;
641 		if (chandef->center_freq1 > control_freq &&
642 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
643 			return false;
644 		break;
645 	case NL80211_CHAN_WIDTH_80P80:
646 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
647 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
648 			return false;
649 	case NL80211_CHAN_WIDTH_80:
650 		if (!vht_cap->vht_supported)
651 			return false;
652 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
653 		width = 80;
654 		break;
655 	case NL80211_CHAN_WIDTH_160:
656 		if (!vht_cap->vht_supported)
657 			return false;
658 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
659 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
660 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
661 			return false;
662 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
663 		width = 160;
664 		break;
665 	default:
666 		WARN_ON_ONCE(1);
667 		return false;
668 	}
669 
670 	/*
671 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
672 	 *	 allowed by the driver, or only certain combinations?
673 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
674 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
675 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
676 	 *	 no way to cover 80+80 MHz or more complex restrictions.
677 	 *	 Note that such restrictions also need to be advertised to
678 	 *	 userspace, for example for P2P channel selection.
679 	 */
680 
681 	if (width > 20)
682 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
683 
684 	/* 5 and 10 MHz are only defined for the OFDM PHY */
685 	if (width < 20)
686 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
687 
688 
689 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
690 					 width, prohibited_flags))
691 		return false;
692 
693 	if (!chandef->center_freq2)
694 		return true;
695 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
696 					   width, prohibited_flags);
697 }
698 EXPORT_SYMBOL(cfg80211_chandef_usable);
699 
700 /*
701  * Check if the channel can be used under permissive conditions mandated by
702  * some regulatory bodies, i.e., the channel is marked with
703  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
704  * associated to an AP on the same channel or on the same UNII band
705  * (assuming that the AP is an authorized master).
706  * In addition allow operation on a channel on which indoor operation is
707  * allowed, iff we are currently operating in an indoor environment.
708  */
709 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
710 					enum nl80211_iftype iftype,
711 					struct ieee80211_channel *chan)
712 {
713 	struct wireless_dev *wdev;
714 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
715 
716 	ASSERT_RTNL();
717 
718 	if (!config_enabled(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
719 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
720 		return false;
721 
722 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
723 	if (iftype != NL80211_IFTYPE_P2P_GO &&
724 	    iftype != NL80211_IFTYPE_STATION &&
725 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
726 		return false;
727 
728 	if (regulatory_indoor_allowed() &&
729 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
730 		return true;
731 
732 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
733 		return false;
734 
735 	/*
736 	 * Generally, it is possible to rely on another device/driver to allow
737 	 * the IR concurrent relaxation, however, since the device can further
738 	 * enforce the relaxation (by doing a similar verifications as this),
739 	 * and thus fail the GO instantiation, consider only the interfaces of
740 	 * the current registered device.
741 	 */
742 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
743 		struct ieee80211_channel *other_chan = NULL;
744 		int r1, r2;
745 
746 		wdev_lock(wdev);
747 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
748 		    wdev->current_bss)
749 			other_chan = wdev->current_bss->pub.channel;
750 
751 		/*
752 		 * If a GO already operates on the same GO_CONCURRENT channel,
753 		 * this one (maybe the same one) can beacon as well. We allow
754 		 * the operation even if the station we relied on with
755 		 * GO_CONCURRENT is disconnected now. But then we must make sure
756 		 * we're not outdoor on an indoor-only channel.
757 		 */
758 		if (iftype == NL80211_IFTYPE_P2P_GO &&
759 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
760 		    wdev->beacon_interval &&
761 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
762 			other_chan = wdev->chandef.chan;
763 		wdev_unlock(wdev);
764 
765 		if (!other_chan)
766 			continue;
767 
768 		if (chan == other_chan)
769 			return true;
770 
771 		if (chan->band != NL80211_BAND_5GHZ)
772 			continue;
773 
774 		r1 = cfg80211_get_unii(chan->center_freq);
775 		r2 = cfg80211_get_unii(other_chan->center_freq);
776 
777 		if (r1 != -EINVAL && r1 == r2) {
778 			/*
779 			 * At some locations channels 149-165 are considered a
780 			 * bundle, but at other locations, e.g., Indonesia,
781 			 * channels 149-161 are considered a bundle while
782 			 * channel 165 is left out and considered to be in a
783 			 * different bundle. Thus, in case that there is a
784 			 * station interface connected to an AP on channel 165,
785 			 * it is assumed that channels 149-161 are allowed for
786 			 * GO operations. However, having a station interface
787 			 * connected to an AP on channels 149-161, does not
788 			 * allow GO operation on channel 165.
789 			 */
790 			if (chan->center_freq == 5825 &&
791 			    other_chan->center_freq != 5825)
792 				continue;
793 			return true;
794 		}
795 	}
796 
797 	return false;
798 }
799 
800 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
801 				     struct cfg80211_chan_def *chandef,
802 				     enum nl80211_iftype iftype,
803 				     bool check_no_ir)
804 {
805 	bool res;
806 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
807 			       IEEE80211_CHAN_RADAR;
808 
809 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
810 
811 	if (check_no_ir)
812 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
813 
814 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
815 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
816 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
817 		prohibited_flags = IEEE80211_CHAN_DISABLED;
818 	}
819 
820 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
821 
822 	trace_cfg80211_return_bool(res);
823 	return res;
824 }
825 
826 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
827 			     struct cfg80211_chan_def *chandef,
828 			     enum nl80211_iftype iftype)
829 {
830 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
831 }
832 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
833 
834 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
835 				   struct cfg80211_chan_def *chandef,
836 				   enum nl80211_iftype iftype)
837 {
838 	bool check_no_ir;
839 
840 	ASSERT_RTNL();
841 
842 	/*
843 	 * Under certain conditions suggested by some regulatory bodies a
844 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
845 	 * only if such relaxations are not enabled and the conditions are not
846 	 * met.
847 	 */
848 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
849 						   chandef->chan);
850 
851 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
852 }
853 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
854 
855 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
856 				 struct cfg80211_chan_def *chandef)
857 {
858 	if (!rdev->ops->set_monitor_channel)
859 		return -EOPNOTSUPP;
860 	if (!cfg80211_has_monitors_only(rdev))
861 		return -EBUSY;
862 
863 	return rdev_set_monitor_channel(rdev, chandef);
864 }
865 
866 void
867 cfg80211_get_chan_state(struct wireless_dev *wdev,
868 		        struct ieee80211_channel **chan,
869 		        enum cfg80211_chan_mode *chanmode,
870 		        u8 *radar_detect)
871 {
872 	int ret;
873 
874 	*chan = NULL;
875 	*chanmode = CHAN_MODE_UNDEFINED;
876 
877 	ASSERT_WDEV_LOCK(wdev);
878 
879 	if (wdev->netdev && !netif_running(wdev->netdev))
880 		return;
881 
882 	switch (wdev->iftype) {
883 	case NL80211_IFTYPE_ADHOC:
884 		if (wdev->current_bss) {
885 			*chan = wdev->current_bss->pub.channel;
886 			*chanmode = (wdev->ibss_fixed &&
887 				     !wdev->ibss_dfs_possible)
888 				  ? CHAN_MODE_SHARED
889 				  : CHAN_MODE_EXCLUSIVE;
890 
891 			/* consider worst-case - IBSS can try to return to the
892 			 * original user-specified channel as creator */
893 			if (wdev->ibss_dfs_possible)
894 				*radar_detect |= BIT(wdev->chandef.width);
895 			return;
896 		}
897 		break;
898 	case NL80211_IFTYPE_STATION:
899 	case NL80211_IFTYPE_P2P_CLIENT:
900 		if (wdev->current_bss) {
901 			*chan = wdev->current_bss->pub.channel;
902 			*chanmode = CHAN_MODE_SHARED;
903 			return;
904 		}
905 		break;
906 	case NL80211_IFTYPE_AP:
907 	case NL80211_IFTYPE_P2P_GO:
908 		if (wdev->cac_started) {
909 			*chan = wdev->chandef.chan;
910 			*chanmode = CHAN_MODE_SHARED;
911 			*radar_detect |= BIT(wdev->chandef.width);
912 		} else if (wdev->beacon_interval) {
913 			*chan = wdev->chandef.chan;
914 			*chanmode = CHAN_MODE_SHARED;
915 
916 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
917 							    &wdev->chandef,
918 							    wdev->iftype);
919 			WARN_ON(ret < 0);
920 			if (ret > 0)
921 				*radar_detect |= BIT(wdev->chandef.width);
922 		}
923 		return;
924 	case NL80211_IFTYPE_MESH_POINT:
925 		if (wdev->mesh_id_len) {
926 			*chan = wdev->chandef.chan;
927 			*chanmode = CHAN_MODE_SHARED;
928 
929 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
930 							    &wdev->chandef,
931 							    wdev->iftype);
932 			WARN_ON(ret < 0);
933 			if (ret > 0)
934 				*radar_detect |= BIT(wdev->chandef.width);
935 		}
936 		return;
937 	case NL80211_IFTYPE_OCB:
938 		if (wdev->chandef.chan) {
939 			*chan = wdev->chandef.chan;
940 			*chanmode = CHAN_MODE_SHARED;
941 			return;
942 		}
943 		break;
944 	case NL80211_IFTYPE_MONITOR:
945 	case NL80211_IFTYPE_AP_VLAN:
946 	case NL80211_IFTYPE_WDS:
947 	case NL80211_IFTYPE_P2P_DEVICE:
948 		/* these interface types don't really have a channel */
949 		return;
950 	case NL80211_IFTYPE_UNSPECIFIED:
951 	case NUM_NL80211_IFTYPES:
952 		WARN_ON(1);
953 	}
954 }
955