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;
 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                 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
 647                         return false;
 648         case NL80211_CHAN_WIDTH_80:
 649                 if (!vht_cap->vht_supported)
 650                         return false;
 651                 prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
 652                 width = 80;
 653                 break;
 654         case NL80211_CHAN_WIDTH_160:
 655                 if (!vht_cap->vht_supported)
 656                         return false;
 657                 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
 658                         return false;
 659                 prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
 660                 width = 160;
 661                 break;
 662         default:
 663                 WARN_ON_ONCE(1);
 664                 return false;
 665         }
 666
 667         /*
 668          * TODO: What if there are only certain 80/160/80+80 MHz channels
 669          *       allowed by the driver, or only certain combinations?
 670          *       For 40 MHz the driver can set the NO_HT40 flags, but for
 671          *       80/160 MHz and in particular 80+80 MHz this isn't really
 672          *       feasible and we only have NO_80MHZ/NO_160MHZ so far but
 673          *       no way to cover 80+80 MHz or more complex restrictions.
 674          *       Note that such restrictions also need to be advertised to
 675          *       userspace, for example for P2P channel selection.
 676          */
 677
 678         if (width > 20)
 679                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 680
 681         /* 5 and 10 MHz are only defined for the OFDM PHY */
 682         if (width < 20)
 683                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 684
 685
 686         if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
 687                                          width, prohibited_flags))
 688                 return false;
 689
 690         if (!chandef->center_freq2)
 691                 return true;
 692         return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
 693                                            width, prohibited_flags);
 694 }
 695 EXPORT_SYMBOL(cfg80211_chandef_usable);
 696
 697 /*
 698  * For GO only, check if the channel can be used under permissive conditions
 699  * mandated by the some regulatory bodies, i.e., the channel is marked with
 700  * IEEE80211_CHAN_GO_CONCURRENT and there is an additional station interface
 701  * associated to an AP on the same channel or on the same UNII band
 702  * (assuming that the AP is an authorized master).
 703  * In addition allow the GO to operate on a channel on which indoor operation is
 704  * allowed, iff we are currently operating in an indoor environment.
 705  */
 706 static bool cfg80211_go_permissive_chan(struct cfg80211_registered_device *rdev,
 707                                         struct ieee80211_channel *chan)
 708 {
 709         struct wireless_dev *wdev_iter;
 710         struct wiphy *wiphy = wiphy_idx_to_wiphy(rdev->wiphy_idx);
 711
 712         ASSERT_RTNL();
 713
 714         if (!config_enabled(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
 715             !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
 716                 return false;
 717
 718         if (regulatory_indoor_allowed() &&
 719             (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
 720                 return true;
 721
 722         if (!(chan->flags & IEEE80211_CHAN_GO_CONCURRENT))
 723                 return false;
 724
 725         /*
 726          * Generally, it is possible to rely on another device/driver to allow
 727          * the GO concurrent relaxation, however, since the device can further
 728          * enforce the relaxation (by doing a similar verifications as this),
 729          * and thus fail the GO instantiation, consider only the interfaces of
 730          * the current registered device.
 731          */
 732         list_for_each_entry(wdev_iter, &rdev->wdev_list, list) {
 733                 struct ieee80211_channel *other_chan = NULL;
 734                 int r1, r2;
 735
 736                 if (wdev_iter->iftype != NL80211_IFTYPE_STATION ||
 737                     !netif_running(wdev_iter->netdev))
 738                         continue;
 739
 740                 wdev_lock(wdev_iter);
 741                 if (wdev_iter->current_bss)
 742                         other_chan = wdev_iter->current_bss->pub.channel;
 743                 wdev_unlock(wdev_iter);
 744
 745                 if (!other_chan)
 746                         continue;
 747
 748                 if (chan == other_chan)
 749                         return true;
 750
 751                 if (chan->band != IEEE80211_BAND_5GHZ)
 752                         continue;
 753
 754                 r1 = cfg80211_get_unii(chan->center_freq);
 755                 r2 = cfg80211_get_unii(other_chan->center_freq);
 756
 757                 if (r1 != -EINVAL && r1 == r2) {
 758                         /*
 759                          * At some locations channels 149-165 are considered a
 760                          * bundle, but at other locations, e.g., Indonesia,
 761                          * channels 149-161 are considered a bundle while
 762                          * channel 165 is left out and considered to be in a
 763                          * different bundle. Thus, in case that there is a
 764                          * station interface connected to an AP on channel 165,
 765                          * it is assumed that channels 149-161 are allowed for
 766                          * GO operations. However, having a station interface
 767                          * connected to an AP on channels 149-161, does not
 768                          * allow GO operation on channel 165.
 769                          */
 770                         if (chan->center_freq == 5825 &&
 771                             other_chan->center_freq != 5825)
 772                                 continue;
 773                         return true;
 774                 }
 775         }
 776
 777         return false;
 778 }
 779
 780 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
 781                              struct cfg80211_chan_def *chandef,
 782                              enum nl80211_iftype iftype)
 783 {
 784         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 785         bool res;
 786         u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
 787                                IEEE80211_CHAN_RADAR;
 788
 789         trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype);
 790
 791         /*
 792          * Under certain conditions suggested by the some regulatory bodies
 793          * a GO can operate on channels marked with IEEE80211_NO_IR
 794          * so set this flag only if such relaxations are not enabled and
 795          * the conditions are not met.
 796          */
 797         if (iftype != NL80211_IFTYPE_P2P_GO ||
 798             !cfg80211_go_permissive_chan(rdev, chandef->chan))
 799                 prohibited_flags |= IEEE80211_CHAN_NO_IR;
 800
 801         if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
 802             cfg80211_chandef_dfs_available(wiphy, chandef)) {
 803                 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
 804                 prohibited_flags = IEEE80211_CHAN_DISABLED;
 805         }
 806
 807         res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
 808
 809         trace_cfg80211_return_bool(res);
 810         return res;
 811 }
 812 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
 813
 814 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
 815                                  struct cfg80211_chan_def *chandef)
 816 {
 817         if (!rdev->ops->set_monitor_channel)
 818                 return -EOPNOTSUPP;
 819         if (!cfg80211_has_monitors_only(rdev))
 820                 return -EBUSY;
 821
 822         return rdev_set_monitor_channel(rdev, chandef);
 823 }
 824
 825 void
 826 cfg80211_get_chan_state(struct wireless_dev *wdev,
 827                         struct ieee80211_channel **chan,
 828                         enum cfg80211_chan_mode *chanmode,
 829                         u8 *radar_detect)
 830 {
 831         int ret;
 832
 833         *chan = NULL;
 834         *chanmode = CHAN_MODE_UNDEFINED;
 835
 836         ASSERT_WDEV_LOCK(wdev);
 837
 838         if (wdev->netdev && !netif_running(wdev->netdev))
 839                 return;
 840
 841         switch (wdev->iftype) {
 842         case NL80211_IFTYPE_ADHOC:
 843                 if (wdev->current_bss) {
 844                         *chan = wdev->current_bss->pub.channel;
 845                         *chanmode = (wdev->ibss_fixed &&
 846                                      !wdev->ibss_dfs_possible)
 847                                   ? CHAN_MODE_SHARED
 848                                   : CHAN_MODE_EXCLUSIVE;
 849
 850                         /* consider worst-case - IBSS can try to return to the
 851                          * original user-specified channel as creator */
 852                         if (wdev->ibss_dfs_possible)
 853                                 *radar_detect |= BIT(wdev->chandef.width);
 854                         return;
 855                 }
 856                 break;
 857         case NL80211_IFTYPE_STATION:
 858         case NL80211_IFTYPE_P2P_CLIENT:
 859                 if (wdev->current_bss) {
 860                         *chan = wdev->current_bss->pub.channel;
 861                         *chanmode = CHAN_MODE_SHARED;
 862                         return;
 863                 }
 864                 break;
 865         case NL80211_IFTYPE_AP:
 866         case NL80211_IFTYPE_P2P_GO:
 867                 if (wdev->cac_started) {
 868                         *chan = wdev->chandef.chan;
 869                         *chanmode = CHAN_MODE_SHARED;
 870                         *radar_detect |= BIT(wdev->chandef.width);
 871                 } else if (wdev->beacon_interval) {
 872                         *chan = wdev->chandef.chan;
 873                         *chanmode = CHAN_MODE_SHARED;
 874
 875                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
 876                                                             &wdev->chandef,
 877                                                             wdev->iftype);
 878                         WARN_ON(ret < 0);
 879                         if (ret > 0)
 880                                 *radar_detect |= BIT(wdev->chandef.width);
 881                 }
 882                 return;
 883         case NL80211_IFTYPE_MESH_POINT:
 884                 if (wdev->mesh_id_len) {
 885                         *chan = wdev->chandef.chan;
 886                         *chanmode = CHAN_MODE_SHARED;
 887
 888                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
 889                                                             &wdev->chandef,
 890                                                             wdev->iftype);
 891                         WARN_ON(ret < 0);
 892                         if (ret > 0)
 893                                 *radar_detect |= BIT(wdev->chandef.width);
 894                 }
 895                 return;
 896         case NL80211_IFTYPE_OCB:
 897                 if (wdev->chandef.chan) {
 898                         *chan = wdev->chandef.chan;
 899                         *chanmode = CHAN_MODE_SHARED;
 900                         return;
 901                 }
 902                 break;
 903         case NL80211_IFTYPE_MONITOR:
 904         case NL80211_IFTYPE_AP_VLAN:
 905         case NL80211_IFTYPE_WDS:
 906         case NL80211_IFTYPE_P2P_DEVICE:
 907                 /* these interface types don't really have a channel */
 908                 return;
 909         case NL80211_IFTYPE_UNSPECIFIED:
 910         case NUM_NL80211_IFTYPES:
 911                 WARN_ON(1);
 912         }
 913 }