Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / wireless / chan.c
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  * For GO only, check if the channel can be used under permissive conditions
702  * mandated by the some regulatory bodies, i.e., the channel is marked with
703  * IEEE80211_CHAN_GO_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 the GO to operate on a channel on which indoor operation is
707  * allowed, iff we are currently operating in an indoor environment.
708  */
709 static bool cfg80211_go_permissive_chan(struct cfg80211_registered_device *rdev,
710                                         struct ieee80211_channel *chan)
711 {
712         struct wireless_dev *wdev_iter;
713         struct wiphy *wiphy = wiphy_idx_to_wiphy(rdev->wiphy_idx);
714
715         ASSERT_RTNL();
716
717         if (!config_enabled(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
718             !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
719                 return false;
720
721         if (regulatory_indoor_allowed() &&
722             (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
723                 return true;
724
725         if (!(chan->flags & IEEE80211_CHAN_GO_CONCURRENT))
726                 return false;
727
728         /*
729          * Generally, it is possible to rely on another device/driver to allow
730          * the GO concurrent relaxation, however, since the device can further
731          * enforce the relaxation (by doing a similar verifications as this),
732          * and thus fail the GO instantiation, consider only the interfaces of
733          * the current registered device.
734          */
735         list_for_each_entry(wdev_iter, &rdev->wdev_list, list) {
736                 struct ieee80211_channel *other_chan = NULL;
737                 int r1, r2;
738
739                 if (wdev_iter->iftype != NL80211_IFTYPE_STATION ||
740                     !netif_running(wdev_iter->netdev))
741                         continue;
742
743                 wdev_lock(wdev_iter);
744                 if (wdev_iter->current_bss)
745                         other_chan = wdev_iter->current_bss->pub.channel;
746                 wdev_unlock(wdev_iter);
747
748                 if (!other_chan)
749                         continue;
750
751                 if (chan == other_chan)
752                         return true;
753
754                 if (chan->band != IEEE80211_BAND_5GHZ)
755                         continue;
756
757                 r1 = cfg80211_get_unii(chan->center_freq);
758                 r2 = cfg80211_get_unii(other_chan->center_freq);
759
760                 if (r1 != -EINVAL && r1 == r2) {
761                         /*
762                          * At some locations channels 149-165 are considered a
763                          * bundle, but at other locations, e.g., Indonesia,
764                          * channels 149-161 are considered a bundle while
765                          * channel 165 is left out and considered to be in a
766                          * different bundle. Thus, in case that there is a
767                          * station interface connected to an AP on channel 165,
768                          * it is assumed that channels 149-161 are allowed for
769                          * GO operations. However, having a station interface
770                          * connected to an AP on channels 149-161, does not
771                          * allow GO operation on channel 165.
772                          */
773                         if (chan->center_freq == 5825 &&
774                             other_chan->center_freq != 5825)
775                                 continue;
776                         return true;
777                 }
778         }
779
780         return false;
781 }
782
783 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
784                              struct cfg80211_chan_def *chandef,
785                              enum nl80211_iftype iftype)
786 {
787         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
788         bool res;
789         u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
790                                IEEE80211_CHAN_RADAR;
791
792         trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype);
793
794         /*
795          * Under certain conditions suggested by the some regulatory bodies
796          * a GO can operate on channels marked with IEEE80211_NO_IR
797          * so set this flag only if such relaxations are not enabled and
798          * the conditions are not met.
799          */
800         if (iftype != NL80211_IFTYPE_P2P_GO ||
801             !cfg80211_go_permissive_chan(rdev, chandef->chan))
802                 prohibited_flags |= IEEE80211_CHAN_NO_IR;
803
804         if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
805             cfg80211_chandef_dfs_available(wiphy, chandef)) {
806                 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
807                 prohibited_flags = IEEE80211_CHAN_DISABLED;
808         }
809
810         res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
811
812         trace_cfg80211_return_bool(res);
813         return res;
814 }
815 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
816
817 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
818                                  struct cfg80211_chan_def *chandef)
819 {
820         if (!rdev->ops->set_monitor_channel)
821                 return -EOPNOTSUPP;
822         if (!cfg80211_has_monitors_only(rdev))
823                 return -EBUSY;
824
825         return rdev_set_monitor_channel(rdev, chandef);
826 }
827
828 void
829 cfg80211_get_chan_state(struct wireless_dev *wdev,
830                         struct ieee80211_channel **chan,
831                         enum cfg80211_chan_mode *chanmode,
832                         u8 *radar_detect)
833 {
834         int ret;
835
836         *chan = NULL;
837         *chanmode = CHAN_MODE_UNDEFINED;
838
839         ASSERT_WDEV_LOCK(wdev);
840
841         if (wdev->netdev && !netif_running(wdev->netdev))
842                 return;
843
844         switch (wdev->iftype) {
845         case NL80211_IFTYPE_ADHOC:
846                 if (wdev->current_bss) {
847                         *chan = wdev->current_bss->pub.channel;
848                         *chanmode = (wdev->ibss_fixed &&
849                                      !wdev->ibss_dfs_possible)
850                                   ? CHAN_MODE_SHARED
851                                   : CHAN_MODE_EXCLUSIVE;
852
853                         /* consider worst-case - IBSS can try to return to the
854                          * original user-specified channel as creator */
855                         if (wdev->ibss_dfs_possible)
856                                 *radar_detect |= BIT(wdev->chandef.width);
857                         return;
858                 }
859                 break;
860         case NL80211_IFTYPE_STATION:
861         case NL80211_IFTYPE_P2P_CLIENT:
862                 if (wdev->current_bss) {
863                         *chan = wdev->current_bss->pub.channel;
864                         *chanmode = CHAN_MODE_SHARED;
865                         return;
866                 }
867                 break;
868         case NL80211_IFTYPE_AP:
869         case NL80211_IFTYPE_P2P_GO:
870                 if (wdev->cac_started) {
871                         *chan = wdev->chandef.chan;
872                         *chanmode = CHAN_MODE_SHARED;
873                         *radar_detect |= BIT(wdev->chandef.width);
874                 } else if (wdev->beacon_interval) {
875                         *chan = wdev->chandef.chan;
876                         *chanmode = CHAN_MODE_SHARED;
877
878                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
879                                                             &wdev->chandef,
880                                                             wdev->iftype);
881                         WARN_ON(ret < 0);
882                         if (ret > 0)
883                                 *radar_detect |= BIT(wdev->chandef.width);
884                 }
885                 return;
886         case NL80211_IFTYPE_MESH_POINT:
887                 if (wdev->mesh_id_len) {
888                         *chan = wdev->chandef.chan;
889                         *chanmode = CHAN_MODE_SHARED;
890
891                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
892                                                             &wdev->chandef,
893                                                             wdev->iftype);
894                         WARN_ON(ret < 0);
895                         if (ret > 0)
896                                 *radar_detect |= BIT(wdev->chandef.width);
897                 }
898                 return;
899         case NL80211_IFTYPE_OCB:
900                 if (wdev->chandef.chan) {
901                         *chan = wdev->chandef.chan;
902                         *chanmode = CHAN_MODE_SHARED;
903                         return;
904                 }
905                 break;
906         case NL80211_IFTYPE_MONITOR:
907         case NL80211_IFTYPE_AP_VLAN:
908         case NL80211_IFTYPE_WDS:
909         case NL80211_IFTYPE_P2P_DEVICE:
910                 /* these interface types don't really have a channel */
911                 return;
912         case NL80211_IFTYPE_UNSPECIFIED:
913         case NUM_NL80211_IFTYPES:
914                 WARN_ON(1);
915         }
916 }