Merge tag 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford...
[cascardo/linux.git] / 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         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 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
461                                              u32 center_freq,
462                                              u32 bandwidth)
463 {
464         struct ieee80211_channel *c;
465         u32 freq, start_freq, end_freq;
466
467         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
468         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
469
470         /*
471          * Check entire range of channels for the bandwidth.
472          * If any channel in between is disabled or has not
473          * had gone through CAC return false
474          */
475         for (freq = start_freq; freq <= end_freq; freq += 20) {
476                 c = ieee80211_get_channel(wiphy, freq);
477                 if (!c)
478                         return false;
479
480                 if (c->flags & IEEE80211_CHAN_DISABLED)
481                         return false;
482
483                 if ((c->flags & IEEE80211_CHAN_RADAR)  &&
484                     (c->dfs_state != NL80211_DFS_AVAILABLE))
485                         return false;
486         }
487
488         return true;
489 }
490
491 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
492                                 const struct cfg80211_chan_def *chandef)
493 {
494         int width;
495         int r;
496
497         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
498                 return false;
499
500         width = cfg80211_chandef_get_width(chandef);
501         if (width < 0)
502                 return false;
503
504         r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
505                                              width);
506
507         /* If any of channels unavailable for cf1 just return */
508         if (!r)
509                 return r;
510
511         switch (chandef->width) {
512         case NL80211_CHAN_WIDTH_80P80:
513                 WARN_ON(!chandef->center_freq2);
514                 r = cfg80211_get_chans_dfs_available(wiphy,
515                                                      chandef->center_freq2,
516                                                      width);
517                 break;
518         default:
519                 WARN_ON(chandef->center_freq2);
520                 break;
521         }
522
523         return r;
524 }
525
526 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
527                                                     u32 center_freq,
528                                                     u32 bandwidth)
529 {
530         struct ieee80211_channel *c;
531         u32 start_freq, end_freq, freq;
532         unsigned int dfs_cac_ms = 0;
533
534         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
535         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
536
537         for (freq = start_freq; freq <= end_freq; freq += 20) {
538                 c = ieee80211_get_channel(wiphy, freq);
539                 if (!c)
540                         return 0;
541
542                 if (c->flags & IEEE80211_CHAN_DISABLED)
543                         return 0;
544
545                 if (!(c->flags & IEEE80211_CHAN_RADAR))
546                         continue;
547
548                 if (c->dfs_cac_ms > dfs_cac_ms)
549                         dfs_cac_ms = c->dfs_cac_ms;
550         }
551
552         return dfs_cac_ms;
553 }
554
555 unsigned int
556 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
557                               const struct cfg80211_chan_def *chandef)
558 {
559         int width;
560         unsigned int t1 = 0, t2 = 0;
561
562         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
563                 return 0;
564
565         width = cfg80211_chandef_get_width(chandef);
566         if (width < 0)
567                 return 0;
568
569         t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
570                                              chandef->center_freq1,
571                                              width);
572
573         if (!chandef->center_freq2)
574                 return t1;
575
576         t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
577                                              chandef->center_freq2,
578                                              width);
579
580         return max(t1, t2);
581 }
582
583 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
584                                         u32 center_freq, u32 bandwidth,
585                                         u32 prohibited_flags)
586 {
587         struct ieee80211_channel *c;
588         u32 freq, start_freq, end_freq;
589
590         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
591         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
592
593         for (freq = start_freq; freq <= end_freq; freq += 20) {
594                 c = ieee80211_get_channel(wiphy, freq);
595                 if (!c || c->flags & prohibited_flags)
596                         return false;
597         }
598
599         return true;
600 }
601
602 bool cfg80211_chandef_usable(struct wiphy *wiphy,
603                              const struct cfg80211_chan_def *chandef,
604                              u32 prohibited_flags)
605 {
606         struct ieee80211_sta_ht_cap *ht_cap;
607         struct ieee80211_sta_vht_cap *vht_cap;
608         u32 width, control_freq, cap;
609
610         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
611                 return false;
612
613         ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
614         vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
615
616         control_freq = chandef->chan->center_freq;
617
618         switch (chandef->width) {
619         case NL80211_CHAN_WIDTH_5:
620                 width = 5;
621                 break;
622         case NL80211_CHAN_WIDTH_10:
623                 prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
624                 width = 10;
625                 break;
626         case NL80211_CHAN_WIDTH_20:
627                 if (!ht_cap->ht_supported)
628                         return false;
629         case NL80211_CHAN_WIDTH_20_NOHT:
630                 prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
631                 width = 20;
632                 break;
633         case NL80211_CHAN_WIDTH_40:
634                 width = 40;
635                 if (!ht_cap->ht_supported)
636                         return false;
637                 if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
638                     ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
639                         return false;
640                 if (chandef->center_freq1 < control_freq &&
641                     chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
642                         return false;
643                 if (chandef->center_freq1 > control_freq &&
644                     chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
645                         return false;
646                 break;
647         case NL80211_CHAN_WIDTH_80P80:
648                 cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
649                 if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
650                         return false;
651         case NL80211_CHAN_WIDTH_80:
652                 if (!vht_cap->vht_supported)
653                         return false;
654                 prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
655                 width = 80;
656                 break;
657         case NL80211_CHAN_WIDTH_160:
658                 if (!vht_cap->vht_supported)
659                         return false;
660                 cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
661                 if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
662                     cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
663                         return false;
664                 prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
665                 width = 160;
666                 break;
667         default:
668                 WARN_ON_ONCE(1);
669                 return false;
670         }
671
672         /*
673          * TODO: What if there are only certain 80/160/80+80 MHz channels
674          *       allowed by the driver, or only certain combinations?
675          *       For 40 MHz the driver can set the NO_HT40 flags, but for
676          *       80/160 MHz and in particular 80+80 MHz this isn't really
677          *       feasible and we only have NO_80MHZ/NO_160MHZ so far but
678          *       no way to cover 80+80 MHz or more complex restrictions.
679          *       Note that such restrictions also need to be advertised to
680          *       userspace, for example for P2P channel selection.
681          */
682
683         if (width > 20)
684                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
685
686         /* 5 and 10 MHz are only defined for the OFDM PHY */
687         if (width < 20)
688                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
689
690
691         if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
692                                          width, prohibited_flags))
693                 return false;
694
695         if (!chandef->center_freq2)
696                 return true;
697         return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
698                                            width, prohibited_flags);
699 }
700 EXPORT_SYMBOL(cfg80211_chandef_usable);
701
702 /*
703  * Check if the channel can be used under permissive conditions mandated by
704  * some regulatory bodies, i.e., the channel is marked with
705  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
706  * associated to an AP on the same channel or on the same UNII band
707  * (assuming that the AP is an authorized master).
708  * In addition allow operation on a channel on which indoor operation is
709  * allowed, iff we are currently operating in an indoor environment.
710  */
711 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
712                                         enum nl80211_iftype iftype,
713                                         struct ieee80211_channel *chan)
714 {
715         struct wireless_dev *wdev;
716         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
717
718         ASSERT_RTNL();
719
720         if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
721             !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
722                 return false;
723
724         /* only valid for GO and TDLS off-channel (station/p2p-CL) */
725         if (iftype != NL80211_IFTYPE_P2P_GO &&
726             iftype != NL80211_IFTYPE_STATION &&
727             iftype != NL80211_IFTYPE_P2P_CLIENT)
728                 return false;
729
730         if (regulatory_indoor_allowed() &&
731             (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
732                 return true;
733
734         if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
735                 return false;
736
737         /*
738          * Generally, it is possible to rely on another device/driver to allow
739          * the IR concurrent relaxation, however, since the device can further
740          * enforce the relaxation (by doing a similar verifications as this),
741          * and thus fail the GO instantiation, consider only the interfaces of
742          * the current registered device.
743          */
744         list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
745                 struct ieee80211_channel *other_chan = NULL;
746                 int r1, r2;
747
748                 wdev_lock(wdev);
749                 if (wdev->iftype == NL80211_IFTYPE_STATION &&
750                     wdev->current_bss)
751                         other_chan = wdev->current_bss->pub.channel;
752
753                 /*
754                  * If a GO already operates on the same GO_CONCURRENT channel,
755                  * this one (maybe the same one) can beacon as well. We allow
756                  * the operation even if the station we relied on with
757                  * GO_CONCURRENT is disconnected now. But then we must make sure
758                  * we're not outdoor on an indoor-only channel.
759                  */
760                 if (iftype == NL80211_IFTYPE_P2P_GO &&
761                     wdev->iftype == NL80211_IFTYPE_P2P_GO &&
762                     wdev->beacon_interval &&
763                     !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
764                         other_chan = wdev->chandef.chan;
765                 wdev_unlock(wdev);
766
767                 if (!other_chan)
768                         continue;
769
770                 if (chan == other_chan)
771                         return true;
772
773                 if (chan->band != NL80211_BAND_5GHZ)
774                         continue;
775
776                 r1 = cfg80211_get_unii(chan->center_freq);
777                 r2 = cfg80211_get_unii(other_chan->center_freq);
778
779                 if (r1 != -EINVAL && r1 == r2) {
780                         /*
781                          * At some locations channels 149-165 are considered a
782                          * bundle, but at other locations, e.g., Indonesia,
783                          * channels 149-161 are considered a bundle while
784                          * channel 165 is left out and considered to be in a
785                          * different bundle. Thus, in case that there is a
786                          * station interface connected to an AP on channel 165,
787                          * it is assumed that channels 149-161 are allowed for
788                          * GO operations. However, having a station interface
789                          * connected to an AP on channels 149-161, does not
790                          * allow GO operation on channel 165.
791                          */
792                         if (chan->center_freq == 5825 &&
793                             other_chan->center_freq != 5825)
794                                 continue;
795                         return true;
796                 }
797         }
798
799         return false;
800 }
801
802 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
803                                      struct cfg80211_chan_def *chandef,
804                                      enum nl80211_iftype iftype,
805                                      bool check_no_ir)
806 {
807         bool res;
808         u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
809                                IEEE80211_CHAN_RADAR;
810
811         trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
812
813         if (check_no_ir)
814                 prohibited_flags |= IEEE80211_CHAN_NO_IR;
815
816         if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
817             cfg80211_chandef_dfs_available(wiphy, chandef)) {
818                 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
819                 prohibited_flags = IEEE80211_CHAN_DISABLED;
820         }
821
822         res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
823
824         trace_cfg80211_return_bool(res);
825         return res;
826 }
827
828 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
829                              struct cfg80211_chan_def *chandef,
830                              enum nl80211_iftype iftype)
831 {
832         return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
833 }
834 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
835
836 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
837                                    struct cfg80211_chan_def *chandef,
838                                    enum nl80211_iftype iftype)
839 {
840         bool check_no_ir;
841
842         ASSERT_RTNL();
843
844         /*
845          * Under certain conditions suggested by some regulatory bodies a
846          * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
847          * only if such relaxations are not enabled and the conditions are not
848          * met.
849          */
850         check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
851                                                    chandef->chan);
852
853         return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
854 }
855 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
856
857 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
858                                  struct cfg80211_chan_def *chandef)
859 {
860         if (!rdev->ops->set_monitor_channel)
861                 return -EOPNOTSUPP;
862         if (!cfg80211_has_monitors_only(rdev))
863                 return -EBUSY;
864
865         return rdev_set_monitor_channel(rdev, chandef);
866 }
867
868 void
869 cfg80211_get_chan_state(struct wireless_dev *wdev,
870                         struct ieee80211_channel **chan,
871                         enum cfg80211_chan_mode *chanmode,
872                         u8 *radar_detect)
873 {
874         int ret;
875
876         *chan = NULL;
877         *chanmode = CHAN_MODE_UNDEFINED;
878
879         ASSERT_WDEV_LOCK(wdev);
880
881         if (wdev->netdev && !netif_running(wdev->netdev))
882                 return;
883
884         switch (wdev->iftype) {
885         case NL80211_IFTYPE_ADHOC:
886                 if (wdev->current_bss) {
887                         *chan = wdev->current_bss->pub.channel;
888                         *chanmode = (wdev->ibss_fixed &&
889                                      !wdev->ibss_dfs_possible)
890                                   ? CHAN_MODE_SHARED
891                                   : CHAN_MODE_EXCLUSIVE;
892
893                         /* consider worst-case - IBSS can try to return to the
894                          * original user-specified channel as creator */
895                         if (wdev->ibss_dfs_possible)
896                                 *radar_detect |= BIT(wdev->chandef.width);
897                         return;
898                 }
899                 break;
900         case NL80211_IFTYPE_STATION:
901         case NL80211_IFTYPE_P2P_CLIENT:
902                 if (wdev->current_bss) {
903                         *chan = wdev->current_bss->pub.channel;
904                         *chanmode = CHAN_MODE_SHARED;
905                         return;
906                 }
907                 break;
908         case NL80211_IFTYPE_AP:
909         case NL80211_IFTYPE_P2P_GO:
910                 if (wdev->cac_started) {
911                         *chan = wdev->chandef.chan;
912                         *chanmode = CHAN_MODE_SHARED;
913                         *radar_detect |= BIT(wdev->chandef.width);
914                 } else if (wdev->beacon_interval) {
915                         *chan = wdev->chandef.chan;
916                         *chanmode = CHAN_MODE_SHARED;
917
918                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
919                                                             &wdev->chandef,
920                                                             wdev->iftype);
921                         WARN_ON(ret < 0);
922                         if (ret > 0)
923                                 *radar_detect |= BIT(wdev->chandef.width);
924                 }
925                 return;
926         case NL80211_IFTYPE_MESH_POINT:
927                 if (wdev->mesh_id_len) {
928                         *chan = wdev->chandef.chan;
929                         *chanmode = CHAN_MODE_SHARED;
930
931                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
932                                                             &wdev->chandef,
933                                                             wdev->iftype);
934                         WARN_ON(ret < 0);
935                         if (ret > 0)
936                                 *radar_detect |= BIT(wdev->chandef.width);
937                 }
938                 return;
939         case NL80211_IFTYPE_OCB:
940                 if (wdev->chandef.chan) {
941                         *chan = wdev->chandef.chan;
942                         *chanmode = CHAN_MODE_SHARED;
943                         return;
944                 }
945                 break;
946         case NL80211_IFTYPE_MONITOR:
947         case NL80211_IFTYPE_AP_VLAN:
948         case NL80211_IFTYPE_WDS:
949         case NL80211_IFTYPE_P2P_DEVICE:
950         case NL80211_IFTYPE_NAN:
951                 /* these interface types don't really have a channel */
952                 return;
953         case NL80211_IFTYPE_UNSPECIFIED:
954         case NUM_NL80211_IFTYPES:
955                 WARN_ON(1);
956         }
957 }