xref: /openbmc/linux/net/wireless/chan.c (revision bc5aa3a0)
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 		break;
517 	default:
518 		WARN_ON(chandef->center_freq2);
519 		break;
520 	}
521 
522 	return r;
523 }
524 
525 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
526 						    u32 center_freq,
527 						    u32 bandwidth)
528 {
529 	struct ieee80211_channel *c;
530 	u32 start_freq, end_freq, freq;
531 	unsigned int dfs_cac_ms = 0;
532 
533 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
534 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
535 
536 	for (freq = start_freq; freq <= end_freq; freq += 20) {
537 		c = ieee80211_get_channel(wiphy, freq);
538 		if (!c)
539 			return 0;
540 
541 		if (c->flags & IEEE80211_CHAN_DISABLED)
542 			return 0;
543 
544 		if (!(c->flags & IEEE80211_CHAN_RADAR))
545 			continue;
546 
547 		if (c->dfs_cac_ms > dfs_cac_ms)
548 			dfs_cac_ms = c->dfs_cac_ms;
549 	}
550 
551 	return dfs_cac_ms;
552 }
553 
554 unsigned int
555 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
556 			      const struct cfg80211_chan_def *chandef)
557 {
558 	int width;
559 	unsigned int t1 = 0, t2 = 0;
560 
561 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
562 		return 0;
563 
564 	width = cfg80211_chandef_get_width(chandef);
565 	if (width < 0)
566 		return 0;
567 
568 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
569 					     chandef->center_freq1,
570 					     width);
571 
572 	if (!chandef->center_freq2)
573 		return t1;
574 
575 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
576 					     chandef->center_freq2,
577 					     width);
578 
579 	return max(t1, t2);
580 }
581 
582 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
583 					u32 center_freq, u32 bandwidth,
584 					u32 prohibited_flags)
585 {
586 	struct ieee80211_channel *c;
587 	u32 freq, start_freq, end_freq;
588 
589 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
590 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
591 
592 	for (freq = start_freq; freq <= end_freq; freq += 20) {
593 		c = ieee80211_get_channel(wiphy, freq);
594 		if (!c || c->flags & prohibited_flags)
595 			return false;
596 	}
597 
598 	return true;
599 }
600 
601 bool cfg80211_chandef_usable(struct wiphy *wiphy,
602 			     const struct cfg80211_chan_def *chandef,
603 			     u32 prohibited_flags)
604 {
605 	struct ieee80211_sta_ht_cap *ht_cap;
606 	struct ieee80211_sta_vht_cap *vht_cap;
607 	u32 width, control_freq, cap;
608 
609 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
610 		return false;
611 
612 	ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
613 	vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
614 
615 	control_freq = chandef->chan->center_freq;
616 
617 	switch (chandef->width) {
618 	case NL80211_CHAN_WIDTH_5:
619 		width = 5;
620 		break;
621 	case NL80211_CHAN_WIDTH_10:
622 		prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
623 		width = 10;
624 		break;
625 	case NL80211_CHAN_WIDTH_20:
626 		if (!ht_cap->ht_supported)
627 			return false;
628 	case NL80211_CHAN_WIDTH_20_NOHT:
629 		prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
630 		width = 20;
631 		break;
632 	case NL80211_CHAN_WIDTH_40:
633 		width = 40;
634 		if (!ht_cap->ht_supported)
635 			return false;
636 		if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
637 		    ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
638 			return false;
639 		if (chandef->center_freq1 < control_freq &&
640 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
641 			return false;
642 		if (chandef->center_freq1 > control_freq &&
643 		    chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
644 			return false;
645 		break;
646 	case NL80211_CHAN_WIDTH_80P80:
647 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
648 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
649 			return false;
650 	case NL80211_CHAN_WIDTH_80:
651 		if (!vht_cap->vht_supported)
652 			return false;
653 		prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
654 		width = 80;
655 		break;
656 	case NL80211_CHAN_WIDTH_160:
657 		if (!vht_cap->vht_supported)
658 			return false;
659 		cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
660 		if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
661 		    cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
662 			return false;
663 		prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
664 		width = 160;
665 		break;
666 	default:
667 		WARN_ON_ONCE(1);
668 		return false;
669 	}
670 
671 	/*
672 	 * TODO: What if there are only certain 80/160/80+80 MHz channels
673 	 *	 allowed by the driver, or only certain combinations?
674 	 *	 For 40 MHz the driver can set the NO_HT40 flags, but for
675 	 *	 80/160 MHz and in particular 80+80 MHz this isn't really
676 	 *	 feasible and we only have NO_80MHZ/NO_160MHZ so far but
677 	 *	 no way to cover 80+80 MHz or more complex restrictions.
678 	 *	 Note that such restrictions also need to be advertised to
679 	 *	 userspace, for example for P2P channel selection.
680 	 */
681 
682 	if (width > 20)
683 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
684 
685 	/* 5 and 10 MHz are only defined for the OFDM PHY */
686 	if (width < 20)
687 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
688 
689 
690 	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
691 					 width, prohibited_flags))
692 		return false;
693 
694 	if (!chandef->center_freq2)
695 		return true;
696 	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
697 					   width, prohibited_flags);
698 }
699 EXPORT_SYMBOL(cfg80211_chandef_usable);
700 
701 /*
702  * Check if the channel can be used under permissive conditions mandated by
703  * some regulatory bodies, i.e., the channel is marked with
704  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
705  * associated to an AP on the same channel or on the same UNII band
706  * (assuming that the AP is an authorized master).
707  * In addition allow operation on a channel on which indoor operation is
708  * allowed, iff we are currently operating in an indoor environment.
709  */
710 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
711 					enum nl80211_iftype iftype,
712 					struct ieee80211_channel *chan)
713 {
714 	struct wireless_dev *wdev;
715 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
716 
717 	ASSERT_RTNL();
718 
719 	if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
720 	    !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
721 		return false;
722 
723 	/* only valid for GO and TDLS off-channel (station/p2p-CL) */
724 	if (iftype != NL80211_IFTYPE_P2P_GO &&
725 	    iftype != NL80211_IFTYPE_STATION &&
726 	    iftype != NL80211_IFTYPE_P2P_CLIENT)
727 		return false;
728 
729 	if (regulatory_indoor_allowed() &&
730 	    (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
731 		return true;
732 
733 	if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
734 		return false;
735 
736 	/*
737 	 * Generally, it is possible to rely on another device/driver to allow
738 	 * the IR concurrent relaxation, however, since the device can further
739 	 * enforce the relaxation (by doing a similar verifications as this),
740 	 * and thus fail the GO instantiation, consider only the interfaces of
741 	 * the current registered device.
742 	 */
743 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
744 		struct ieee80211_channel *other_chan = NULL;
745 		int r1, r2;
746 
747 		wdev_lock(wdev);
748 		if (wdev->iftype == NL80211_IFTYPE_STATION &&
749 		    wdev->current_bss)
750 			other_chan = wdev->current_bss->pub.channel;
751 
752 		/*
753 		 * If a GO already operates on the same GO_CONCURRENT channel,
754 		 * this one (maybe the same one) can beacon as well. We allow
755 		 * the operation even if the station we relied on with
756 		 * GO_CONCURRENT is disconnected now. But then we must make sure
757 		 * we're not outdoor on an indoor-only channel.
758 		 */
759 		if (iftype == NL80211_IFTYPE_P2P_GO &&
760 		    wdev->iftype == NL80211_IFTYPE_P2P_GO &&
761 		    wdev->beacon_interval &&
762 		    !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
763 			other_chan = wdev->chandef.chan;
764 		wdev_unlock(wdev);
765 
766 		if (!other_chan)
767 			continue;
768 
769 		if (chan == other_chan)
770 			return true;
771 
772 		if (chan->band != NL80211_BAND_5GHZ)
773 			continue;
774 
775 		r1 = cfg80211_get_unii(chan->center_freq);
776 		r2 = cfg80211_get_unii(other_chan->center_freq);
777 
778 		if (r1 != -EINVAL && r1 == r2) {
779 			/*
780 			 * At some locations channels 149-165 are considered a
781 			 * bundle, but at other locations, e.g., Indonesia,
782 			 * channels 149-161 are considered a bundle while
783 			 * channel 165 is left out and considered to be in a
784 			 * different bundle. Thus, in case that there is a
785 			 * station interface connected to an AP on channel 165,
786 			 * it is assumed that channels 149-161 are allowed for
787 			 * GO operations. However, having a station interface
788 			 * connected to an AP on channels 149-161, does not
789 			 * allow GO operation on channel 165.
790 			 */
791 			if (chan->center_freq == 5825 &&
792 			    other_chan->center_freq != 5825)
793 				continue;
794 			return true;
795 		}
796 	}
797 
798 	return false;
799 }
800 
801 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
802 				     struct cfg80211_chan_def *chandef,
803 				     enum nl80211_iftype iftype,
804 				     bool check_no_ir)
805 {
806 	bool res;
807 	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
808 			       IEEE80211_CHAN_RADAR;
809 
810 	trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
811 
812 	if (check_no_ir)
813 		prohibited_flags |= IEEE80211_CHAN_NO_IR;
814 
815 	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
816 	    cfg80211_chandef_dfs_available(wiphy, chandef)) {
817 		/* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
818 		prohibited_flags = IEEE80211_CHAN_DISABLED;
819 	}
820 
821 	res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
822 
823 	trace_cfg80211_return_bool(res);
824 	return res;
825 }
826 
827 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
828 			     struct cfg80211_chan_def *chandef,
829 			     enum nl80211_iftype iftype)
830 {
831 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
832 }
833 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
834 
835 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
836 				   struct cfg80211_chan_def *chandef,
837 				   enum nl80211_iftype iftype)
838 {
839 	bool check_no_ir;
840 
841 	ASSERT_RTNL();
842 
843 	/*
844 	 * Under certain conditions suggested by some regulatory bodies a
845 	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
846 	 * only if such relaxations are not enabled and the conditions are not
847 	 * met.
848 	 */
849 	check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
850 						   chandef->chan);
851 
852 	return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
853 }
854 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
855 
856 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
857 				 struct cfg80211_chan_def *chandef)
858 {
859 	if (!rdev->ops->set_monitor_channel)
860 		return -EOPNOTSUPP;
861 	if (!cfg80211_has_monitors_only(rdev))
862 		return -EBUSY;
863 
864 	return rdev_set_monitor_channel(rdev, chandef);
865 }
866 
867 void
868 cfg80211_get_chan_state(struct wireless_dev *wdev,
869 		        struct ieee80211_channel **chan,
870 		        enum cfg80211_chan_mode *chanmode,
871 		        u8 *radar_detect)
872 {
873 	int ret;
874 
875 	*chan = NULL;
876 	*chanmode = CHAN_MODE_UNDEFINED;
877 
878 	ASSERT_WDEV_LOCK(wdev);
879 
880 	if (wdev->netdev && !netif_running(wdev->netdev))
881 		return;
882 
883 	switch (wdev->iftype) {
884 	case NL80211_IFTYPE_ADHOC:
885 		if (wdev->current_bss) {
886 			*chan = wdev->current_bss->pub.channel;
887 			*chanmode = (wdev->ibss_fixed &&
888 				     !wdev->ibss_dfs_possible)
889 				  ? CHAN_MODE_SHARED
890 				  : CHAN_MODE_EXCLUSIVE;
891 
892 			/* consider worst-case - IBSS can try to return to the
893 			 * original user-specified channel as creator */
894 			if (wdev->ibss_dfs_possible)
895 				*radar_detect |= BIT(wdev->chandef.width);
896 			return;
897 		}
898 		break;
899 	case NL80211_IFTYPE_STATION:
900 	case NL80211_IFTYPE_P2P_CLIENT:
901 		if (wdev->current_bss) {
902 			*chan = wdev->current_bss->pub.channel;
903 			*chanmode = CHAN_MODE_SHARED;
904 			return;
905 		}
906 		break;
907 	case NL80211_IFTYPE_AP:
908 	case NL80211_IFTYPE_P2P_GO:
909 		if (wdev->cac_started) {
910 			*chan = wdev->chandef.chan;
911 			*chanmode = CHAN_MODE_SHARED;
912 			*radar_detect |= BIT(wdev->chandef.width);
913 		} else if (wdev->beacon_interval) {
914 			*chan = wdev->chandef.chan;
915 			*chanmode = CHAN_MODE_SHARED;
916 
917 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
918 							    &wdev->chandef,
919 							    wdev->iftype);
920 			WARN_ON(ret < 0);
921 			if (ret > 0)
922 				*radar_detect |= BIT(wdev->chandef.width);
923 		}
924 		return;
925 	case NL80211_IFTYPE_MESH_POINT:
926 		if (wdev->mesh_id_len) {
927 			*chan = wdev->chandef.chan;
928 			*chanmode = CHAN_MODE_SHARED;
929 
930 			ret = cfg80211_chandef_dfs_required(wdev->wiphy,
931 							    &wdev->chandef,
932 							    wdev->iftype);
933 			WARN_ON(ret < 0);
934 			if (ret > 0)
935 				*radar_detect |= BIT(wdev->chandef.width);
936 		}
937 		return;
938 	case NL80211_IFTYPE_OCB:
939 		if (wdev->chandef.chan) {
940 			*chan = wdev->chandef.chan;
941 			*chanmode = CHAN_MODE_SHARED;
942 			return;
943 		}
944 		break;
945 	case NL80211_IFTYPE_MONITOR:
946 	case NL80211_IFTYPE_AP_VLAN:
947 	case NL80211_IFTYPE_WDS:
948 	case NL80211_IFTYPE_P2P_DEVICE:
949 		/* these interface types don't really have a channel */
950 		return;
951 	case NL80211_IFTYPE_UNSPECIFIED:
952 	case NUM_NL80211_IFTYPES:
953 		WARN_ON(1);
954 	}
955 }
956