net/wireless/chan.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This file contains helper code to handle channel
   4  * settings and keeping track of what is possible at
   5  * any point in time.
   6  *
   7  * Copyright 2009       Johannes Berg <[email protected]>
   8  * Copyright 2013-2014  Intel Mobile Communications GmbH
   9  */
  10
  11 #include <linux/export.h>
  12 #include <net/cfg80211.h>
  13 #include "core.h"
  14 #include "rdev-ops.h"
  15
  16 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
  17                              struct ieee80211_channel *chan,
  18                              enum nl80211_channel_type chan_type)
  19 {
  20         if (WARN_ON(!chan))
  21                 return;
  22
  23         chandef->chan = chan;
  24         chandef->center_freq2 = 0;
  25
  26         switch (chan_type) {
  27         case NL80211_CHAN_NO_HT:
  28                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
  29                 chandef->center_freq1 = chan->center_freq;
  30                 break;
  31         case NL80211_CHAN_HT20:
  32                 chandef->width = NL80211_CHAN_WIDTH_20;
  33                 chandef->center_freq1 = chan->center_freq;
  34                 break;
  35         case NL80211_CHAN_HT40PLUS:
  36                 chandef->width = NL80211_CHAN_WIDTH_40;
  37                 chandef->center_freq1 = chan->center_freq + 10;
  38                 break;
  39         case NL80211_CHAN_HT40MINUS:
  40                 chandef->width = NL80211_CHAN_WIDTH_40;
  41                 chandef->center_freq1 = chan->center_freq - 10;
  42                 break;
  43         default:
  44                 WARN_ON(1);
  45         }
  46 }
  47 EXPORT_SYMBOL(cfg80211_chandef_create);
  48
  49 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
  50 {
  51         u32 control_freq;
  52
  53         if (!chandef->chan)
  54                 return false;
  55
  56         control_freq = chandef->chan->center_freq;
  57
  58         switch (chandef->width) {
  59         case NL80211_CHAN_WIDTH_5:
  60         case NL80211_CHAN_WIDTH_10:
  61         case NL80211_CHAN_WIDTH_20:
  62         case NL80211_CHAN_WIDTH_20_NOHT:
  63                 if (chandef->center_freq1 != control_freq)
  64                         return false;
  65                 if (chandef->center_freq2)
  66                         return false;
  67                 break;
  68         case NL80211_CHAN_WIDTH_40:
  69                 if (chandef->center_freq1 != control_freq + 10 &&
  70                     chandef->center_freq1 != control_freq - 10)
  71                         return false;
  72                 if (chandef->center_freq2)
  73                         return false;
  74                 break;
  75         case NL80211_CHAN_WIDTH_80P80:
  76                 if (chandef->center_freq1 != control_freq + 30 &&
  77                     chandef->center_freq1 != control_freq + 10 &&
  78                     chandef->center_freq1 != control_freq - 10 &&
  79                     chandef->center_freq1 != control_freq - 30)
  80                         return false;
  81                 if (!chandef->center_freq2)
  82                         return false;
  83                 /* adjacent is not allowed -- that's a 160 MHz channel */
  84                 if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
  85                     chandef->center_freq2 - chandef->center_freq1 == 80)
  86                         return false;
  87                 break;
  88         case NL80211_CHAN_WIDTH_80:
  89                 if (chandef->center_freq1 != control_freq + 30 &&
  90                     chandef->center_freq1 != control_freq + 10 &&
  91                     chandef->center_freq1 != control_freq - 10 &&
  92                     chandef->center_freq1 != control_freq - 30)
  93                         return false;
  94                 if (chandef->center_freq2)
  95                         return false;
  96                 break;
  97         case NL80211_CHAN_WIDTH_160:
  98                 if (chandef->center_freq1 != control_freq + 70 &&
  99                     chandef->center_freq1 != control_freq + 50 &&
 100                     chandef->center_freq1 != control_freq + 30 &&
 101                     chandef->center_freq1 != control_freq + 10 &&
 102                     chandef->center_freq1 != control_freq - 10 &&
 103                     chandef->center_freq1 != control_freq - 30 &&
 104                     chandef->center_freq1 != control_freq - 50 &&
 105                     chandef->center_freq1 != control_freq - 70)
 106                         return false;
 107                 if (chandef->center_freq2)
 108                         return false;
 109                 break;
 110         default:
 111                 return false;
 112         }
 113
 114         return true;
 115 }
 116 EXPORT_SYMBOL(cfg80211_chandef_valid);
 117
 118 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
 119                                   u32 *pri40, u32 *pri80)
 120 {
 121         int tmp;
 122
 123         switch (c->width) {
 124         case NL80211_CHAN_WIDTH_40:
 125                 *pri40 = c->center_freq1;
 126                 *pri80 = 0;
 127                 break;
 128         case NL80211_CHAN_WIDTH_80:
 129         case NL80211_CHAN_WIDTH_80P80:
 130                 *pri80 = c->center_freq1;
 131                 /* n_P20 */
 132                 tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
 133                 /* n_P40 */
 134                 tmp /= 2;
 135                 /* freq_P40 */
 136                 *pri40 = c->center_freq1 - 20 + 40 * tmp;
 137                 break;
 138         case NL80211_CHAN_WIDTH_160:
 139                 /* n_P20 */
 140                 tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
 141                 /* n_P40 */
 142                 tmp /= 2;
 143                 /* freq_P40 */
 144                 *pri40 = c->center_freq1 - 60 + 40 * tmp;
 145                 /* n_P80 */
 146                 tmp /= 2;
 147                 *pri80 = c->center_freq1 - 40 + 80 * tmp;
 148                 break;
 149         default:
 150                 WARN_ON_ONCE(1);
 151         }
 152 }
 153
 154 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
 155 {
 156         int width;
 157
 158         switch (c->width) {
 159         case NL80211_CHAN_WIDTH_5:
 160                 width = 5;
 161                 break;
 162         case NL80211_CHAN_WIDTH_10:
 163                 width = 10;
 164                 break;
 165         case NL80211_CHAN_WIDTH_20:
 166         case NL80211_CHAN_WIDTH_20_NOHT:
 167                 width = 20;
 168                 break;
 169         case NL80211_CHAN_WIDTH_40:
 170                 width = 40;
 171                 break;
 172         case NL80211_CHAN_WIDTH_80P80:
 173         case NL80211_CHAN_WIDTH_80:
 174                 width = 80;
 175                 break;
 176         case NL80211_CHAN_WIDTH_160:
 177                 width = 160;
 178                 break;
 179         default:
 180                 WARN_ON_ONCE(1);
 181                 return -1;
 182         }
 183         return width;
 184 }
 185
 186 const struct cfg80211_chan_def *
 187 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
 188                             const struct cfg80211_chan_def *c2)
 189 {
 190         u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
 191
 192         /* If they are identical, return */
 193         if (cfg80211_chandef_identical(c1, c2))
 194                 return c1;
 195
 196         /* otherwise, must have same control channel */
 197         if (c1->chan != c2->chan)
 198                 return NULL;
 199
 200         /*
 201          * If they have the same width, but aren't identical,
 202          * then they can't be compatible.
 203          */
 204         if (c1->width == c2->width)
 205                 return NULL;
 206
 207         /*
 208          * can't be compatible if one of them is 5 or 10 MHz,
 209          * but they don't have the same width.
 210          */
 211         if (c1->width == NL80211_CHAN_WIDTH_5 ||
 212             c1->width == NL80211_CHAN_WIDTH_10 ||
 213             c2->width == NL80211_CHAN_WIDTH_5 ||
 214             c2->width == NL80211_CHAN_WIDTH_10)
 215                 return NULL;
 216
 217         if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
 218             c1->width == NL80211_CHAN_WIDTH_20)
 219                 return c2;
 220
 221         if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
 222             c2->width == NL80211_CHAN_WIDTH_20)
 223                 return c1;
 224
 225         chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
 226         chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
 227
 228         if (c1_pri40 != c2_pri40)
 229                 return NULL;
 230
 231         WARN_ON(!c1_pri80 && !c2_pri80);
 232         if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
 233                 return NULL;
 234
 235         if (c1->width > c2->width)
 236                 return c1;
 237         return c2;
 238 }
 239 EXPORT_SYMBOL(cfg80211_chandef_compatible);
 240
 241 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
 242                                          u32 bandwidth,
 243                                          enum nl80211_dfs_state dfs_state)
 244 {
 245         struct ieee80211_channel *c;
 246         u32 freq;
 247
 248         for (freq = center_freq - bandwidth/2 + 10;
 249              freq <= center_freq + bandwidth/2 - 10;
 250              freq += 20) {
 251                 c = ieee80211_get_channel(wiphy, freq);
 252                 if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
 253                         continue;
 254
 255                 c->dfs_state = dfs_state;
 256                 c->dfs_state_entered = jiffies;
 257         }
 258 }
 259
 260 void cfg80211_set_dfs_state(struct wiphy *wiphy,
 261                             const struct cfg80211_chan_def *chandef,
 262                             enum nl80211_dfs_state dfs_state)
 263 {
 264         int width;
 265
 266         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 267                 return;
 268
 269         width = cfg80211_chandef_get_width(chandef);
 270         if (width < 0)
 271                 return;
 272
 273         cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
 274                                      width, dfs_state);
 275
 276         if (!chandef->center_freq2)
 277                 return;
 278         cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
 279                                      width, dfs_state);
 280 }
 281
 282 static u32 cfg80211_get_start_freq(u32 center_freq,
 283                                    u32 bandwidth)
 284 {
 285         u32 start_freq;
 286
 287         if (bandwidth <= 20)
 288                 start_freq = center_freq;
 289         else
 290                 start_freq = center_freq - bandwidth/2 + 10;
 291
 292         return start_freq;
 293 }
 294
 295 static u32 cfg80211_get_end_freq(u32 center_freq,
 296                                  u32 bandwidth)
 297 {
 298         u32 end_freq;
 299
 300         if (bandwidth <= 20)
 301                 end_freq = center_freq;
 302         else
 303                 end_freq = center_freq + bandwidth/2 - 10;
 304
 305         return end_freq;
 306 }
 307
 308 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
 309                                             u32 center_freq,
 310                                             u32 bandwidth)
 311 {
 312         struct ieee80211_channel *c;
 313         u32 freq, start_freq, end_freq;
 314
 315         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 316         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 317
 318         for (freq = start_freq; freq <= end_freq; freq += 20) {
 319                 c = ieee80211_get_channel(wiphy, freq);
 320                 if (!c)
 321                         return -EINVAL;
 322
 323                 if (c->flags & IEEE80211_CHAN_RADAR)
 324                         return 1;
 325         }
 326         return 0;
 327 }
 328
 329
 330 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
 331                                   const struct cfg80211_chan_def *chandef,
 332                                   enum nl80211_iftype iftype)
 333 {
 334         int width;
 335         int ret;
 336
 337         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 338                 return -EINVAL;
 339
 340         switch (iftype) {
 341         case NL80211_IFTYPE_ADHOC:
 342         case NL80211_IFTYPE_AP:
 343         case NL80211_IFTYPE_P2P_GO:
 344         case NL80211_IFTYPE_MESH_POINT:
 345                 width = cfg80211_chandef_get_width(chandef);
 346                 if (width < 0)
 347                         return -EINVAL;
 348
 349                 ret = cfg80211_get_chans_dfs_required(wiphy,
 350                                                       chandef->center_freq1,
 351                                                       width);
 352                 if (ret < 0)
 353                         return ret;
 354                 else if (ret > 0)
 355                         return BIT(chandef->width);
 356
 357                 if (!chandef->center_freq2)
 358                         return 0;
 359
 360                 ret = cfg80211_get_chans_dfs_required(wiphy,
 361                                                       chandef->center_freq2,
 362                                                       width);
 363                 if (ret < 0)
 364                         return ret;
 365                 else if (ret > 0)
 366                         return BIT(chandef->width);
 367
 368                 break;
 369         case NL80211_IFTYPE_STATION:
 370         case NL80211_IFTYPE_OCB:
 371         case NL80211_IFTYPE_P2P_CLIENT:
 372         case NL80211_IFTYPE_MONITOR:
 373         case NL80211_IFTYPE_AP_VLAN:
 374         case NL80211_IFTYPE_WDS:
 375         case NL80211_IFTYPE_P2P_DEVICE:
 376         case NL80211_IFTYPE_NAN:
 377                 break;
 378         case NL80211_IFTYPE_UNSPECIFIED:
 379         case NUM_NL80211_IFTYPES:
 380                 WARN_ON(1);
 381         }
 382
 383         return 0;
 384 }
 385 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
 386
 387 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
 388                                          u32 center_freq,
 389                                          u32 bandwidth)
 390 {
 391         struct ieee80211_channel *c;
 392         u32 freq, start_freq, end_freq;
 393         int count = 0;
 394
 395         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 396         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 397
 398         /*
 399          * Check entire range of channels for the bandwidth.
 400          * Check all channels are DFS channels (DFS_USABLE or
 401          * DFS_AVAILABLE). Return number of usable channels
 402          * (require CAC). Allow DFS and non-DFS channel mix.
 403          */
 404         for (freq = start_freq; freq <= end_freq; freq += 20) {
 405                 c = ieee80211_get_channel(wiphy, freq);
 406                 if (!c)
 407                         return -EINVAL;
 408
 409                 if (c->flags & IEEE80211_CHAN_DISABLED)
 410                         return -EINVAL;
 411
 412                 if (c->flags & IEEE80211_CHAN_RADAR) {
 413                         if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
 414                                 return -EINVAL;
 415
 416                         if (c->dfs_state == NL80211_DFS_USABLE)
 417                                 count++;
 418                 }
 419         }
 420
 421         return count;
 422 }
 423
 424 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
 425                                  const struct cfg80211_chan_def *chandef)
 426 {
 427         int width;
 428         int r1, r2 = 0;
 429
 430         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 431                 return false;
 432
 433         width = cfg80211_chandef_get_width(chandef);
 434         if (width < 0)
 435                 return false;
 436
 437         r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
 438                                           width);
 439
 440         if (r1 < 0)
 441                 return false;
 442
 443         switch (chandef->width) {
 444         case NL80211_CHAN_WIDTH_80P80:
 445                 WARN_ON(!chandef->center_freq2);
 446                 r2 = cfg80211_get_chans_dfs_usable(wiphy,
 447                                                    chandef->center_freq2,
 448                                                    width);
 449                 if (r2 < 0)
 450                         return false;
 451                 break;
 452         default:
 453                 WARN_ON(chandef->center_freq2);
 454                 break;
 455         }
 456
 457         return (r1 + r2 > 0);
 458 }
 459
 460 /*
 461  * Checks if center frequency of chan falls with in the bandwidth
 462  * range of chandef.
 463  */
 464 bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
 465                           struct ieee80211_channel *chan)
 466 {
 467         int width;
 468         u32 freq;
 469
 470         if (chandef->chan->center_freq == chan->center_freq)
 471                 return true;
 472
 473         width = cfg80211_chandef_get_width(chandef);
 474         if (width <= 20)
 475                 return false;
 476
 477         for (freq = chandef->center_freq1 - width / 2 + 10;
 478              freq <= chandef->center_freq1 + width / 2 - 10; freq += 20) {
 479                 if (chan->center_freq == freq)
 480                         return true;
 481         }
 482
 483         if (!chandef->center_freq2)
 484                 return false;
 485
 486         for (freq = chandef->center_freq2 - width / 2 + 10;
 487              freq <= chandef->center_freq2 + width / 2 - 10; freq += 20) {
 488                 if (chan->center_freq == freq)
 489                         return true;
 490         }
 491
 492         return false;
 493 }
 494
 495 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
 496 {
 497         bool active = false;
 498
 499         ASSERT_WDEV_LOCK(wdev);
 500
 501         if (!wdev->chandef.chan)
 502                 return false;
 503
 504         switch (wdev->iftype) {
 505         case NL80211_IFTYPE_AP:
 506         case NL80211_IFTYPE_P2P_GO:
 507                 active = wdev->beacon_interval != 0;
 508                 break;
 509         case NL80211_IFTYPE_ADHOC:
 510                 active = wdev->ssid_len != 0;
 511                 break;
 512         case NL80211_IFTYPE_MESH_POINT:
 513                 active = wdev->mesh_id_len != 0;
 514                 break;
 515         case NL80211_IFTYPE_STATION:
 516         case NL80211_IFTYPE_OCB:
 517         case NL80211_IFTYPE_P2P_CLIENT:
 518         case NL80211_IFTYPE_MONITOR:
 519         case NL80211_IFTYPE_AP_VLAN:
 520         case NL80211_IFTYPE_WDS:
 521         case NL80211_IFTYPE_P2P_DEVICE:
 522         /* Can NAN type be considered as beaconing interface? */
 523         case NL80211_IFTYPE_NAN:
 524                 break;
 525         case NL80211_IFTYPE_UNSPECIFIED:
 526         case NUM_NL80211_IFTYPES:
 527                 WARN_ON(1);
 528         }
 529
 530         return active;
 531 }
 532
 533 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
 534                                         struct ieee80211_channel *chan)
 535 {
 536         struct wireless_dev *wdev;
 537
 538         list_for_each_entry(wdev, &wiphy->wdev_list, list) {
 539                 wdev_lock(wdev);
 540                 if (!cfg80211_beaconing_iface_active(wdev)) {
 541                         wdev_unlock(wdev);
 542                         continue;
 543                 }
 544
 545                 if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
 546                         wdev_unlock(wdev);
 547                         return true;
 548                 }
 549                 wdev_unlock(wdev);
 550         }
 551
 552         return false;
 553 }
 554
 555 bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
 556                                   struct ieee80211_channel *chan)
 557 {
 558         struct cfg80211_registered_device *rdev;
 559
 560         ASSERT_RTNL();
 561
 562         if (!(chan->flags & IEEE80211_CHAN_RADAR))
 563                 return false;
 564
 565         list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
 566                 if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
 567                         continue;
 568
 569                 if (cfg80211_is_wiphy_oper_chan(&rdev->wiphy, chan))
 570                         return true;
 571         }
 572
 573         return false;
 574 }
 575
 576 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
 577                                              u32 center_freq,
 578                                              u32 bandwidth)
 579 {
 580         struct ieee80211_channel *c;
 581         u32 freq, start_freq, end_freq;
 582         bool dfs_offload;
 583
 584         dfs_offload = wiphy_ext_feature_isset(wiphy,
 585                                               NL80211_EXT_FEATURE_DFS_OFFLOAD);
 586
 587         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 588         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 589
 590         /*
 591          * Check entire range of channels for the bandwidth.
 592          * If any channel in between is disabled or has not
 593          * had gone through CAC return false
 594          */
 595         for (freq = start_freq; freq <= end_freq; freq += 20) {
 596                 c = ieee80211_get_channel(wiphy, freq);
 597                 if (!c)
 598                         return false;
 599
 600                 if (c->flags & IEEE80211_CHAN_DISABLED)
 601                         return false;
 602
 603                 if ((c->flags & IEEE80211_CHAN_RADAR) &&
 604                     (c->dfs_state != NL80211_DFS_AVAILABLE) &&
 605                     !(c->dfs_state == NL80211_DFS_USABLE && dfs_offload))
 606                         return false;
 607         }
 608
 609         return true;
 610 }
 611
 612 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
 613                                 const struct cfg80211_chan_def *chandef)
 614 {
 615         int width;
 616         int r;
 617
 618         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 619                 return false;
 620
 621         width = cfg80211_chandef_get_width(chandef);
 622         if (width < 0)
 623                 return false;
 624
 625         r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
 626                                              width);
 627
 628         /* If any of channels unavailable for cf1 just return */
 629         if (!r)
 630                 return r;
 631
 632         switch (chandef->width) {
 633         case NL80211_CHAN_WIDTH_80P80:
 634                 WARN_ON(!chandef->center_freq2);
 635                 r = cfg80211_get_chans_dfs_available(wiphy,
 636                                                      chandef->center_freq2,
 637                                                      width);
 638                 break;
 639         default:
 640                 WARN_ON(chandef->center_freq2);
 641                 break;
 642         }
 643
 644         return r;
 645 }
 646
 647 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
 648                                                     u32 center_freq,
 649                                                     u32 bandwidth)
 650 {
 651         struct ieee80211_channel *c;
 652         u32 start_freq, end_freq, freq;
 653         unsigned int dfs_cac_ms = 0;
 654
 655         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 656         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 657
 658         for (freq = start_freq; freq <= end_freq; freq += 20) {
 659                 c = ieee80211_get_channel(wiphy, freq);
 660                 if (!c)
 661                         return 0;
 662
 663                 if (c->flags & IEEE80211_CHAN_DISABLED)
 664                         return 0;
 665
 666                 if (!(c->flags & IEEE80211_CHAN_RADAR))
 667                         continue;
 668
 669                 if (c->dfs_cac_ms > dfs_cac_ms)
 670                         dfs_cac_ms = c->dfs_cac_ms;
 671         }
 672
 673         return dfs_cac_ms;
 674 }
 675
 676 unsigned int
 677 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
 678                               const struct cfg80211_chan_def *chandef)
 679 {
 680         int width;
 681         unsigned int t1 = 0, t2 = 0;
 682
 683         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 684                 return 0;
 685
 686         width = cfg80211_chandef_get_width(chandef);
 687         if (width < 0)
 688                 return 0;
 689
 690         t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
 691                                              chandef->center_freq1,
 692                                              width);
 693
 694         if (!chandef->center_freq2)
 695                 return t1;
 696
 697         t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
 698                                              chandef->center_freq2,
 699                                              width);
 700
 701         return max(t1, t2);
 702 }
 703
 704 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
 705                                         u32 center_freq, u32 bandwidth,
 706                                         u32 prohibited_flags)
 707 {
 708         struct ieee80211_channel *c;
 709         u32 freq, start_freq, end_freq;
 710
 711         start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 712         end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 713
 714         for (freq = start_freq; freq <= end_freq; freq += 20) {
 715                 c = ieee80211_get_channel(wiphy, freq);
 716                 if (!c || c->flags & prohibited_flags)
 717                         return false;
 718         }
 719
 720         return true;
 721 }
 722
 723 bool cfg80211_chandef_usable(struct wiphy *wiphy,
 724                              const struct cfg80211_chan_def *chandef,
 725                              u32 prohibited_flags)
 726 {
 727         struct ieee80211_sta_ht_cap *ht_cap;
 728         struct ieee80211_sta_vht_cap *vht_cap;
 729         u32 width, control_freq, cap;
 730
 731         if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 732                 return false;
 733
 734         ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
 735         vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
 736
 737         control_freq = chandef->chan->center_freq;
 738
 739         switch (chandef->width) {
 740         case NL80211_CHAN_WIDTH_5:
 741                 width = 5;
 742                 break;
 743         case NL80211_CHAN_WIDTH_10:
 744                 prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
 745                 width = 10;
 746                 break;
 747         case NL80211_CHAN_WIDTH_20:
 748                 if (!ht_cap->ht_supported)
 749                         return false;
 750         case NL80211_CHAN_WIDTH_20_NOHT:
 751                 prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
 752                 width = 20;
 753                 break;
 754         case NL80211_CHAN_WIDTH_40:
 755                 width = 40;
 756                 if (!ht_cap->ht_supported)
 757                         return false;
 758                 if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
 759                     ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
 760                         return false;
 761                 if (chandef->center_freq1 < control_freq &&
 762                     chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
 763                         return false;
 764                 if (chandef->center_freq1 > control_freq &&
 765                     chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
 766                         return false;
 767                 break;
 768         case NL80211_CHAN_WIDTH_80P80:
 769                 cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
 770                 if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
 771                         return false;
 772         case NL80211_CHAN_WIDTH_80:
 773                 if (!vht_cap->vht_supported)
 774                         return false;
 775                 prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
 776                 width = 80;
 777                 break;
 778         case NL80211_CHAN_WIDTH_160:
 779                 if (!vht_cap->vht_supported)
 780                         return false;
 781                 cap = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
 782                 if (cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
 783                     cap != IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
 784                         return false;
 785                 prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
 786                 width = 160;
 787                 break;
 788         default:
 789                 WARN_ON_ONCE(1);
 790                 return false;
 791         }
 792
 793         /*
 794          * TODO: What if there are only certain 80/160/80+80 MHz channels
 795          *       allowed by the driver, or only certain combinations?
 796          *       For 40 MHz the driver can set the NO_HT40 flags, but for
 797          *       80/160 MHz and in particular 80+80 MHz this isn't really
 798          *       feasible and we only have NO_80MHZ/NO_160MHZ so far but
 799          *       no way to cover 80+80 MHz or more complex restrictions.
 800          *       Note that such restrictions also need to be advertised to
 801          *       userspace, for example for P2P channel selection.
 802          */
 803
 804         if (width > 20)
 805                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 806
 807         /* 5 and 10 MHz are only defined for the OFDM PHY */
 808         if (width < 20)
 809                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 810
 811
 812         if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
 813                                          width, prohibited_flags))
 814                 return false;
 815
 816         if (!chandef->center_freq2)
 817                 return true;
 818         return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
 819                                            width, prohibited_flags);
 820 }
 821 EXPORT_SYMBOL(cfg80211_chandef_usable);
 822
 823 /*
 824  * Check if the channel can be used under permissive conditions mandated by
 825  * some regulatory bodies, i.e., the channel is marked with
 826  * IEEE80211_CHAN_IR_CONCURRENT and there is an additional station interface
 827  * associated to an AP on the same channel or on the same UNII band
 828  * (assuming that the AP is an authorized master).
 829  * In addition allow operation on a channel on which indoor operation is
 830  * allowed, iff we are currently operating in an indoor environment.
 831  */
 832 static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
 833                                         enum nl80211_iftype iftype,
 834                                         struct ieee80211_channel *chan)
 835 {
 836         struct wireless_dev *wdev;
 837         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 838
 839         ASSERT_RTNL();
 840
 841         if (!IS_ENABLED(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
 842             !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
 843                 return false;
 844
 845         /* only valid for GO and TDLS off-channel (station/p2p-CL) */
 846         if (iftype != NL80211_IFTYPE_P2P_GO &&
 847             iftype != NL80211_IFTYPE_STATION &&
 848             iftype != NL80211_IFTYPE_P2P_CLIENT)
 849                 return false;
 850
 851         if (regulatory_indoor_allowed() &&
 852             (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
 853                 return true;
 854
 855         if (!(chan->flags & IEEE80211_CHAN_IR_CONCURRENT))
 856                 return false;
 857
 858         /*
 859          * Generally, it is possible to rely on another device/driver to allow
 860          * the IR concurrent relaxation, however, since the device can further
 861          * enforce the relaxation (by doing a similar verifications as this),
 862          * and thus fail the GO instantiation, consider only the interfaces of
 863          * the current registered device.
 864          */
 865         list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 866                 struct ieee80211_channel *other_chan = NULL;
 867                 int r1, r2;
 868
 869                 wdev_lock(wdev);
 870                 if (wdev->iftype == NL80211_IFTYPE_STATION &&
 871                     wdev->current_bss)
 872                         other_chan = wdev->current_bss->pub.channel;
 873
 874                 /*
 875                  * If a GO already operates on the same GO_CONCURRENT channel,
 876                  * this one (maybe the same one) can beacon as well. We allow
 877                  * the operation even if the station we relied on with
 878                  * GO_CONCURRENT is disconnected now. But then we must make sure
 879                  * we're not outdoor on an indoor-only channel.
 880                  */
 881                 if (iftype == NL80211_IFTYPE_P2P_GO &&
 882                     wdev->iftype == NL80211_IFTYPE_P2P_GO &&
 883                     wdev->beacon_interval &&
 884                     !(chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
 885                         other_chan = wdev->chandef.chan;
 886                 wdev_unlock(wdev);
 887
 888                 if (!other_chan)
 889                         continue;
 890
 891                 if (chan == other_chan)
 892                         return true;
 893
 894                 if (chan->band != NL80211_BAND_5GHZ)
 895                         continue;
 896
 897                 r1 = cfg80211_get_unii(chan->center_freq);
 898                 r2 = cfg80211_get_unii(other_chan->center_freq);
 899
 900                 if (r1 != -EINVAL && r1 == r2) {
 901                         /*
 902                          * At some locations channels 149-165 are considered a
 903                          * bundle, but at other locations, e.g., Indonesia,
 904                          * channels 149-161 are considered a bundle while
 905                          * channel 165 is left out and considered to be in a
 906                          * different bundle. Thus, in case that there is a
 907                          * station interface connected to an AP on channel 165,
 908                          * it is assumed that channels 149-161 are allowed for
 909                          * GO operations. However, having a station interface
 910                          * connected to an AP on channels 149-161, does not
 911                          * allow GO operation on channel 165.
 912                          */
 913                         if (chan->center_freq == 5825 &&
 914                             other_chan->center_freq != 5825)
 915                                 continue;
 916                         return true;
 917                 }
 918         }
 919
 920         return false;
 921 }
 922
 923 static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy,
 924                                      struct cfg80211_chan_def *chandef,
 925                                      enum nl80211_iftype iftype,
 926                                      bool check_no_ir)
 927 {
 928         bool res;
 929         u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
 930                                IEEE80211_CHAN_RADAR;
 931
 932         trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
 933
 934         if (check_no_ir)
 935                 prohibited_flags |= IEEE80211_CHAN_NO_IR;
 936
 937         if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
 938             cfg80211_chandef_dfs_available(wiphy, chandef)) {
 939                 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
 940                 prohibited_flags = IEEE80211_CHAN_DISABLED;
 941         }
 942
 943         res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
 944
 945         trace_cfg80211_return_bool(res);
 946         return res;
 947 }
 948
 949 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
 950                              struct cfg80211_chan_def *chandef,
 951                              enum nl80211_iftype iftype)
 952 {
 953         return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, true);
 954 }
 955 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
 956
 957 bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
 958                                    struct cfg80211_chan_def *chandef,
 959                                    enum nl80211_iftype iftype)
 960 {
 961         bool check_no_ir;
 962
 963         ASSERT_RTNL();
 964
 965         /*
 966          * Under certain conditions suggested by some regulatory bodies a
 967          * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
 968          * only if such relaxations are not enabled and the conditions are not
 969          * met.
 970          */
 971         check_no_ir = !cfg80211_ir_permissive_chan(wiphy, iftype,
 972                                                    chandef->chan);
 973
 974         return _cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir);
 975 }
 976 EXPORT_SYMBOL(cfg80211_reg_can_beacon_relax);
 977
 978 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
 979                                  struct cfg80211_chan_def *chandef)
 980 {
 981         if (!rdev->ops->set_monitor_channel)
 982                 return -EOPNOTSUPP;
 983         if (!cfg80211_has_monitors_only(rdev))
 984                 return -EBUSY;
 985
 986         return rdev_set_monitor_channel(rdev, chandef);
 987 }
 988
 989 void
 990 cfg80211_get_chan_state(struct wireless_dev *wdev,
 991                         struct ieee80211_channel **chan,
 992                         enum cfg80211_chan_mode *chanmode,
 993                         u8 *radar_detect)
 994 {
 995         int ret;
 996
 997         *chan = NULL;
 998         *chanmode = CHAN_MODE_UNDEFINED;
 999
1000         ASSERT_WDEV_LOCK(wdev);
1001
1002         if (wdev->netdev && !netif_running(wdev->netdev))
1003                 return;
1004
1005         switch (wdev->iftype) {
1006         case NL80211_IFTYPE_ADHOC:
1007                 if (wdev->current_bss) {
1008                         *chan = wdev->current_bss->pub.channel;
1009                         *chanmode = (wdev->ibss_fixed &&
1010                                      !wdev->ibss_dfs_possible)
1011                                   ? CHAN_MODE_SHARED
1012                                   : CHAN_MODE_EXCLUSIVE;
1013
1014                         /* consider worst-case - IBSS can try to return to the
1015                          * original user-specified channel as creator */
1016                         if (wdev->ibss_dfs_possible)
1017                                 *radar_detect |= BIT(wdev->chandef.width);
1018                         return;
1019                 }
1020                 break;
1021         case NL80211_IFTYPE_STATION:
1022         case NL80211_IFTYPE_P2P_CLIENT:
1023                 if (wdev->current_bss) {
1024                         *chan = wdev->current_bss->pub.channel;
1025                         *chanmode = CHAN_MODE_SHARED;
1026                         return;
1027                 }
1028                 break;
1029         case NL80211_IFTYPE_AP:
1030         case NL80211_IFTYPE_P2P_GO:
1031                 if (wdev->cac_started) {
1032                         *chan = wdev->chandef.chan;
1033                         *chanmode = CHAN_MODE_SHARED;
1034                         *radar_detect |= BIT(wdev->chandef.width);
1035                 } else if (wdev->beacon_interval) {
1036                         *chan = wdev->chandef.chan;
1037                         *chanmode = CHAN_MODE_SHARED;
1038
1039                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1040                                                             &wdev->chandef,
1041                                                             wdev->iftype);
1042                         WARN_ON(ret < 0);
1043                         if (ret > 0)
1044                                 *radar_detect |= BIT(wdev->chandef.width);
1045                 }
1046                 return;
1047         case NL80211_IFTYPE_MESH_POINT:
1048                 if (wdev->mesh_id_len) {
1049                         *chan = wdev->chandef.chan;
1050                         *chanmode = CHAN_MODE_SHARED;
1051
1052                         ret = cfg80211_chandef_dfs_required(wdev->wiphy,
1053                                                             &wdev->chandef,
1054                                                             wdev->iftype);
1055                         WARN_ON(ret < 0);
1056                         if (ret > 0)
1057                                 *radar_detect |= BIT(wdev->chandef.width);
1058                 }
1059                 return;
1060         case NL80211_IFTYPE_OCB:
1061                 if (wdev->chandef.chan) {
1062                         *chan = wdev->chandef.chan;
1063                         *chanmode = CHAN_MODE_SHARED;
1064                         return;
1065                 }
1066                 break;
1067         case NL80211_IFTYPE_MONITOR:
1068         case NL80211_IFTYPE_AP_VLAN:
1069         case NL80211_IFTYPE_WDS:
1070         case NL80211_IFTYPE_P2P_DEVICE:
1071         case NL80211_IFTYPE_NAN:
1072                 /* these interface types don't really have a channel */
1073                 return;
1074         case NL80211_IFTYPE_UNSPECIFIED:
1075         case NUM_NL80211_IFTYPES:
1076                 WARN_ON(1);
1077         }
1078 }