libeap/src/ap/dfs.c

   1 /*
   2  * DFS - Dynamic Frequency Selection
   3  * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 2013-2015, Qualcomm Atheros, Inc.
   5  *
   6  * This software may be distributed under the terms of the BSD license.
   7  * See README for more details.
   8  */
   9
  10 #include "utils/includes.h"
  11
  12 #include "utils/common.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "common/hw_features_common.h"
  15 #include "common/wpa_ctrl.h"
  16 #include "hostapd.h"
  17 #include "ap_drv_ops.h"
  18 #include "drivers/driver.h"
  19 #include "dfs.h"
  20
  21
  22 static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1)
  23 {
  24         int n_chans = 1;
  25
  26         *seg1 = 0;
  27
  28         if (iface->conf->ieee80211n && iface->conf->secondary_channel)
  29                 n_chans = 2;
  30
  31         if (iface->conf->ieee80211ac) {
  32                 switch (iface->conf->vht_oper_chwidth) {
  33                 case VHT_CHANWIDTH_USE_HT:
  34                         break;
  35                 case VHT_CHANWIDTH_80MHZ:
  36                         n_chans = 4;
  37                         break;
  38                 case VHT_CHANWIDTH_160MHZ:
  39                         n_chans = 8;
  40                         break;
  41                 case VHT_CHANWIDTH_80P80MHZ:
  42                         n_chans = 4;
  43                         *seg1 = 4;
  44                         break;
  45                 default:
  46                         break;
  47                 }
  48         }
  49
  50         return n_chans;
  51 }
  52
  53
  54 static int dfs_channel_available(struct hostapd_channel_data *chan,
  55                                  int skip_radar)
  56 {
  57         /*
  58          * When radar detection happens, CSA is performed. However, there's no
  59          * time for CAC, so radar channels must be skipped when finding a new
  60          * channel for CSA, unless they are available for immediate use.
  61          */
  62         if (skip_radar && (chan->flag & HOSTAPD_CHAN_RADAR) &&
  63             ((chan->flag & HOSTAPD_CHAN_DFS_MASK) !=
  64              HOSTAPD_CHAN_DFS_AVAILABLE))
  65                 return 0;
  66
  67         if (chan->flag & HOSTAPD_CHAN_DISABLED)
  68                 return 0;
  69         if ((chan->flag & HOSTAPD_CHAN_RADAR) &&
  70             ((chan->flag & HOSTAPD_CHAN_DFS_MASK) ==
  71              HOSTAPD_CHAN_DFS_UNAVAILABLE))
  72                 return 0;
  73         return 1;
  74 }
  75
  76
  77 static int dfs_is_chan_allowed(struct hostapd_channel_data *chan, int n_chans)
  78 {
  79         /*
  80          * The tables contain first valid channel number based on channel width.
  81          * We will also choose this first channel as the control one.
  82          */
  83         int allowed_40[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
  84                              184, 192 };
  85         /*
  86          * VHT80, valid channels based on center frequency:
  87          * 42, 58, 106, 122, 138, 155
  88          */
  89         int allowed_80[] = { 36, 52, 100, 116, 132, 149 };
  90         /*
  91          * VHT160 valid channels based on center frequency:
  92          * 50, 114
  93          */
  94         int allowed_160[] = { 36, 100 };
  95         int *allowed = allowed_40;
  96         unsigned int i, allowed_no = 0;
  97
  98         switch (n_chans) {
  99         case 2:
 100                 allowed = allowed_40;
 101                 allowed_no = ARRAY_SIZE(allowed_40);
 102                 break;
 103         case 4:
 104                 allowed = allowed_80;
 105                 allowed_no = ARRAY_SIZE(allowed_80);
 106                 break;
 107         case 8:
 108                 allowed = allowed_160;
 109                 allowed_no = ARRAY_SIZE(allowed_160);
 110                 break;
 111         default:
 112                 wpa_printf(MSG_DEBUG, "Unknown width for %d channels", n_chans);
 113                 break;
 114         }
 115
 116         for (i = 0; i < allowed_no; i++) {
 117                 if (chan->chan == allowed[i])
 118                         return 1;
 119         }
 120
 121         return 0;
 122 }
 123
 124
 125 static struct hostapd_channel_data *
 126 dfs_get_chan_data(struct hostapd_hw_modes *mode, int freq, int first_chan_idx)
 127 {
 128         int i;
 129
 130         for (i = first_chan_idx; i < mode->num_channels; i++) {
 131                 if (mode->channels[i].freq == freq)
 132                         return &mode->channels[i];
 133         }
 134
 135         return NULL;
 136 }
 137
 138
 139 static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
 140                                     int first_chan_idx, int num_chans,
 141                                     int skip_radar)
 142 {
 143         struct hostapd_channel_data *first_chan, *chan;
 144         int i;
 145
 146         if (first_chan_idx + num_chans > mode->num_channels)
 147                 return 0;
 148
 149         first_chan = &mode->channels[first_chan_idx];
 150
 151         for (i = 0; i < num_chans; i++) {
 152                 chan = dfs_get_chan_data(mode, first_chan->freq + i * 20,
 153                                          first_chan_idx);
 154                 if (!chan)
 155                         return 0;
 156
 157                 if (!dfs_channel_available(chan, skip_radar))
 158                         return 0;
 159         }
 160
 161         return 1;
 162 }
 163
 164
 165 static int is_in_chanlist(struct hostapd_iface *iface,
 166                           struct hostapd_channel_data *chan)
 167 {
 168         if (!iface->conf->acs_ch_list.num)
 169                 return 1;
 170
 171         return freq_range_list_includes(&iface->conf->acs_ch_list, chan->chan);
 172 }
 173
 174
 175 /*
 176  * The function assumes HT40+ operation.
 177  * Make sure to adjust the following variables after calling this:
 178  *  - hapd->secondary_channel
 179  *  - hapd->vht_oper_centr_freq_seg0_idx
 180  *  - hapd->vht_oper_centr_freq_seg1_idx
 181  */
 182 static int dfs_find_channel(struct hostapd_iface *iface,
 183                             struct hostapd_channel_data **ret_chan,
 184                             int idx, int skip_radar)
 185 {
 186         struct hostapd_hw_modes *mode;
 187         struct hostapd_channel_data *chan;
 188         int i, channel_idx = 0, n_chans, n_chans1;
 189
 190         mode = iface->current_mode;
 191         n_chans = dfs_get_used_n_chans(iface, &n_chans1);
 192
 193         wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
 194         for (i = 0; i < mode->num_channels; i++) {
 195                 chan = &mode->channels[i];
 196
 197                 /* Skip HT40/VHT incompatible channels */
 198                 if (iface->conf->ieee80211n &&
 199                     iface->conf->secondary_channel &&
 200                     !dfs_is_chan_allowed(chan, n_chans))
 201                         continue;
 202
 203                 /* Skip incompatible chandefs */
 204                 if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
 205                         continue;
 206
 207                 if (!is_in_chanlist(iface, chan))
 208                         continue;
 209
 210                 if (ret_chan && idx == channel_idx) {
 211                         wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
 212                         *ret_chan = chan;
 213                         return idx;
 214                 }
 215                 wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
 216                 channel_idx++;
 217         }
 218         return channel_idx;
 219 }
 220
 221
 222 static void dfs_adjust_vht_center_freq(struct hostapd_iface *iface,
 223                                        struct hostapd_channel_data *chan,
 224                                        int secondary_channel,
 225                                        u8 *vht_oper_centr_freq_seg0_idx,
 226                                        u8 *vht_oper_centr_freq_seg1_idx)
 227 {
 228         if (!iface->conf->ieee80211ac)
 229                 return;
 230
 231         if (!chan)
 232                 return;
 233
 234         *vht_oper_centr_freq_seg1_idx = 0;
 235
 236         switch (iface->conf->vht_oper_chwidth) {
 237         case VHT_CHANWIDTH_USE_HT:
 238                 if (secondary_channel == 1)
 239                         *vht_oper_centr_freq_seg0_idx = chan->chan + 2;
 240                 else if (secondary_channel == -1)
 241                         *vht_oper_centr_freq_seg0_idx = chan->chan - 2;
 242                 else
 243                         *vht_oper_centr_freq_seg0_idx = chan->chan;
 244                 break;
 245         case VHT_CHANWIDTH_80MHZ:
 246                 *vht_oper_centr_freq_seg0_idx = chan->chan + 6;
 247                 break;
 248         case VHT_CHANWIDTH_160MHZ:
 249                 *vht_oper_centr_freq_seg0_idx = chan->chan + 14;
 250                 break;
 251         default:
 252                 wpa_printf(MSG_INFO, "DFS only VHT20/40/80/160 is supported now");
 253                 *vht_oper_centr_freq_seg0_idx = 0;
 254                 break;
 255         }
 256
 257         wpa_printf(MSG_DEBUG, "DFS adjusting VHT center frequency: %d, %d",
 258                    *vht_oper_centr_freq_seg0_idx,
 259                    *vht_oper_centr_freq_seg1_idx);
 260 }
 261
 262
 263 /* Return start channel idx we will use for mode->channels[idx] */
 264 static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start)
 265 {
 266         struct hostapd_hw_modes *mode;
 267         struct hostapd_channel_data *chan;
 268         int channel_no = iface->conf->channel;
 269         int res = -1, i;
 270         int chan_seg1 = -1;
 271
 272         *seg1_start = -1;
 273
 274         /* HT40- */
 275         if (iface->conf->ieee80211n && iface->conf->secondary_channel == -1)
 276                 channel_no -= 4;
 277
 278         /* VHT */
 279         if (iface->conf->ieee80211ac) {
 280                 switch (iface->conf->vht_oper_chwidth) {
 281                 case VHT_CHANWIDTH_USE_HT:
 282                         break;
 283                 case VHT_CHANWIDTH_80MHZ:
 284                         channel_no =
 285                                 iface->conf->vht_oper_centr_freq_seg0_idx - 6;
 286                         break;
 287                 case VHT_CHANWIDTH_160MHZ:
 288                         channel_no =
 289                                 iface->conf->vht_oper_centr_freq_seg0_idx - 14;
 290                         break;
 291                 case VHT_CHANWIDTH_80P80MHZ:
 292                         channel_no =
 293                                 iface->conf->vht_oper_centr_freq_seg0_idx - 6;
 294                         chan_seg1 =
 295                                 iface->conf->vht_oper_centr_freq_seg1_idx - 6;
 296                         break;
 297                 default:
 298                         wpa_printf(MSG_INFO,
 299                                    "DFS only VHT20/40/80/160/80+80 is supported now");
 300                         channel_no = -1;
 301                         break;
 302                 }
 303         }
 304
 305         /* Get idx */
 306         mode = iface->current_mode;
 307         for (i = 0; i < mode->num_channels; i++) {
 308                 chan = &mode->channels[i];
 309                 if (chan->chan == channel_no) {
 310                         res = i;
 311                         break;
 312                 }
 313         }
 314
 315         if (res != -1 && chan_seg1 > -1) {
 316                 int found = 0;
 317
 318                 /* Get idx for seg1 */
 319                 mode = iface->current_mode;
 320                 for (i = 0; i < mode->num_channels; i++) {
 321                         chan = &mode->channels[i];
 322                         if (chan->chan == chan_seg1) {
 323                                 *seg1_start = i;
 324                                 found = 1;
 325                                 break;
 326                         }
 327                 }
 328                 if (!found)
 329                         res = -1;
 330         }
 331
 332         if (res == -1) {
 333                 wpa_printf(MSG_DEBUG,
 334                            "DFS chan_idx seems wrong; num-ch: %d ch-no: %d conf-ch-no: %d 11n: %d sec-ch: %d vht-oper-width: %d",
 335                            mode->num_channels, channel_no, iface->conf->channel,
 336                            iface->conf->ieee80211n,
 337                            iface->conf->secondary_channel,
 338                            iface->conf->vht_oper_chwidth);
 339
 340                 for (i = 0; i < mode->num_channels; i++) {
 341                         wpa_printf(MSG_DEBUG, "Available channel: %d",
 342                                    mode->channels[i].chan);
 343                 }
 344         }
 345
 346         return res;
 347 }
 348
 349
 350 /* At least one channel have radar flag */
 351 static int dfs_check_chans_radar(struct hostapd_iface *iface,
 352                                  int start_chan_idx, int n_chans)
 353 {
 354         struct hostapd_channel_data *channel;
 355         struct hostapd_hw_modes *mode;
 356         int i, res = 0;
 357
 358         mode = iface->current_mode;
 359
 360         for (i = 0; i < n_chans; i++) {
 361                 channel = &mode->channels[start_chan_idx + i];
 362                 if (channel->flag & HOSTAPD_CHAN_RADAR)
 363                         res++;
 364         }
 365
 366         return res;
 367 }
 368
 369
 370 /* All channels available */
 371 static int dfs_check_chans_available(struct hostapd_iface *iface,
 372                                      int start_chan_idx, int n_chans)
 373 {
 374         struct hostapd_channel_data *channel;
 375         struct hostapd_hw_modes *mode;
 376         int i;
 377
 378         mode = iface->current_mode;
 379
 380         for (i = 0; i < n_chans; i++) {
 381                 channel = &mode->channels[start_chan_idx + i];
 382
 383                 if (channel->flag & HOSTAPD_CHAN_DISABLED)
 384                         break;
 385
 386                 if (!(channel->flag & HOSTAPD_CHAN_RADAR))
 387                         continue;
 388
 389                 if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) !=
 390                     HOSTAPD_CHAN_DFS_AVAILABLE)
 391                         break;
 392         }
 393
 394         return i == n_chans;
 395 }
 396
 397
 398 /* At least one channel unavailable */
 399 static int dfs_check_chans_unavailable(struct hostapd_iface *iface,
 400                                        int start_chan_idx,
 401                                        int n_chans)
 402 {
 403         struct hostapd_channel_data *channel;
 404         struct hostapd_hw_modes *mode;
 405         int i, res = 0;
 406
 407         mode = iface->current_mode;
 408
 409         for (i = 0; i < n_chans; i++) {
 410                 channel = &mode->channels[start_chan_idx + i];
 411                 if (channel->flag & HOSTAPD_CHAN_DISABLED)
 412                         res++;
 413                 if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) ==
 414                     HOSTAPD_CHAN_DFS_UNAVAILABLE)
 415                         res++;
 416         }
 417
 418         return res;
 419 }
 420
 421
 422 static struct hostapd_channel_data *
 423 dfs_get_valid_channel(struct hostapd_iface *iface,
 424                       int *secondary_channel,
 425                       u8 *vht_oper_centr_freq_seg0_idx,
 426                       u8 *vht_oper_centr_freq_seg1_idx,
 427                       int skip_radar)
 428 {
 429         struct hostapd_hw_modes *mode;
 430         struct hostapd_channel_data *chan = NULL;
 431         int num_available_chandefs;
 432         int chan_idx;
 433         u32 _rand;
 434
 435         wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
 436         *secondary_channel = 0;
 437         *vht_oper_centr_freq_seg0_idx = 0;
 438         *vht_oper_centr_freq_seg1_idx = 0;
 439
 440         if (iface->current_mode == NULL)
 441                 return NULL;
 442
 443         mode = iface->current_mode;
 444         if (mode->mode != HOSTAPD_MODE_IEEE80211A)
 445                 return NULL;
 446
 447         /* Get the count first */
 448         num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
 449         if (num_available_chandefs == 0)
 450                 return NULL;
 451
 452         if (os_get_random((u8 *) &_rand, sizeof(_rand)) < 0)
 453                 return NULL;
 454         chan_idx = _rand % num_available_chandefs;
 455         dfs_find_channel(iface, &chan, chan_idx, skip_radar);
 456
 457         /* dfs_find_channel() calculations assume HT40+ */
 458         if (iface->conf->secondary_channel)
 459                 *secondary_channel = 1;
 460         else
 461                 *secondary_channel = 0;
 462
 463         dfs_adjust_vht_center_freq(iface, chan,
 464                                    *secondary_channel,
 465                                    vht_oper_centr_freq_seg0_idx,
 466                                    vht_oper_centr_freq_seg1_idx);
 467
 468         return chan;
 469 }
 470
 471
 472 static int set_dfs_state_freq(struct hostapd_iface *iface, int freq, u32 state)
 473 {
 474         struct hostapd_hw_modes *mode;
 475         struct hostapd_channel_data *chan = NULL;
 476         int i;
 477
 478         mode = iface->current_mode;
 479         if (mode == NULL)
 480                 return 0;
 481
 482         wpa_printf(MSG_DEBUG, "set_dfs_state 0x%X for %d MHz", state, freq);
 483         for (i = 0; i < iface->current_mode->num_channels; i++) {
 484                 chan = &iface->current_mode->channels[i];
 485                 if (chan->freq == freq) {
 486                         if (chan->flag & HOSTAPD_CHAN_RADAR) {
 487                                 chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
 488                                 chan->flag |= state;
 489                                 return 1; /* Channel found */
 490                         }
 491                 }
 492         }
 493         wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
 494         return 0;
 495 }
 496
 497
 498 static int set_dfs_state(struct hostapd_iface *iface, int freq, int ht_enabled,
 499                          int chan_offset, int chan_width, int cf1,
 500                          int cf2, u32 state)
 501 {
 502         int n_chans = 1, i;
 503         struct hostapd_hw_modes *mode;
 504         int frequency = freq;
 505         int ret = 0;
 506
 507         mode = iface->current_mode;
 508         if (mode == NULL)
 509                 return 0;
 510
 511         if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
 512                 wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
 513                 return 0;
 514         }
 515
 516         /* Seems cf1 and chan_width is enough here */
 517         switch (chan_width) {
 518         case CHAN_WIDTH_20_NOHT:
 519         case CHAN_WIDTH_20:
 520                 n_chans = 1;
 521                 if (frequency == 0)
 522                         frequency = cf1;
 523                 break;
 524         case CHAN_WIDTH_40:
 525                 n_chans = 2;
 526                 frequency = cf1 - 10;
 527                 break;
 528         case CHAN_WIDTH_80:
 529                 n_chans = 4;
 530                 frequency = cf1 - 30;
 531                 break;
 532         case CHAN_WIDTH_160:
 533                 n_chans = 8;
 534                 frequency = cf1 - 70;
 535                 break;
 536         default:
 537                 wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
 538                            chan_width);
 539                 break;
 540         }
 541
 542         wpa_printf(MSG_DEBUG, "DFS freq: %dMHz, n_chans: %d", frequency,
 543                    n_chans);
 544         for (i = 0; i < n_chans; i++) {
 545                 ret += set_dfs_state_freq(iface, frequency, state);
 546                 frequency = frequency + 20;
 547         }
 548
 549         return ret;
 550 }
 551
 552
 553 static int dfs_are_channels_overlapped(struct hostapd_iface *iface, int freq,
 554                                        int chan_width, int cf1, int cf2)
 555 {
 556         int start_chan_idx, start_chan_idx1;
 557         struct hostapd_hw_modes *mode;
 558         struct hostapd_channel_data *chan;
 559         int n_chans, n_chans1, i, j, frequency = freq, radar_n_chans = 1;
 560         u8 radar_chan;
 561         int res = 0;
 562
 563         /* Our configuration */
 564         mode = iface->current_mode;
 565         start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
 566         n_chans = dfs_get_used_n_chans(iface, &n_chans1);
 567
 568         /* Check we are on DFS channel(s) */
 569         if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
 570                 return 0;
 571
 572         /* Reported via radar event */
 573         switch (chan_width) {
 574         case CHAN_WIDTH_20_NOHT:
 575         case CHAN_WIDTH_20:
 576                 radar_n_chans = 1;
 577                 if (frequency == 0)
 578                         frequency = cf1;
 579                 break;
 580         case CHAN_WIDTH_40:
 581                 radar_n_chans = 2;
 582                 frequency = cf1 - 10;
 583                 break;
 584         case CHAN_WIDTH_80:
 585                 radar_n_chans = 4;
 586                 frequency = cf1 - 30;
 587                 break;
 588         case CHAN_WIDTH_160:
 589                 radar_n_chans = 8;
 590                 frequency = cf1 - 70;
 591                 break;
 592         default:
 593                 wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
 594                            chan_width);
 595                 break;
 596         }
 597
 598         ieee80211_freq_to_chan(frequency, &radar_chan);
 599
 600         for (i = 0; i < n_chans; i++) {
 601                 chan = &mode->channels[start_chan_idx + i];
 602                 if (!(chan->flag & HOSTAPD_CHAN_RADAR))
 603                         continue;
 604                 for (j = 0; j < radar_n_chans; j++) {
 605                         wpa_printf(MSG_DEBUG, "checking our: %d, radar: %d",
 606                                    chan->chan, radar_chan + j * 4);
 607                         if (chan->chan == radar_chan + j * 4)
 608                                 res++;
 609                 }
 610         }
 611
 612         wpa_printf(MSG_DEBUG, "overlapped: %d", res);
 613
 614         return res;
 615 }
 616
 617
 618 static unsigned int dfs_get_cac_time(struct hostapd_iface *iface,
 619                                      int start_chan_idx, int n_chans)
 620 {
 621         struct hostapd_channel_data *channel;
 622         struct hostapd_hw_modes *mode;
 623         int i;
 624         unsigned int cac_time_ms = 0;
 625
 626         mode = iface->current_mode;
 627
 628         for (i = 0; i < n_chans; i++) {
 629                 channel = &mode->channels[start_chan_idx + i];
 630                 if (!(channel->flag & HOSTAPD_CHAN_RADAR))
 631                         continue;
 632                 if (channel->dfs_cac_ms > cac_time_ms)
 633                         cac_time_ms = channel->dfs_cac_ms;
 634         }
 635
 636         return cac_time_ms;
 637 }
 638
 639
 640 /*
 641  * Main DFS handler
 642  * 1 - continue channel/ap setup
 643  * 0 - channel/ap setup will be continued after CAC
 644  * -1 - hit critical error
 645  */
 646 int hostapd_handle_dfs(struct hostapd_iface *iface)
 647 {
 648         struct hostapd_channel_data *channel;
 649         int res, n_chans, n_chans1, start_chan_idx, start_chan_idx1;
 650         int skip_radar = 0;
 651
 652         if (!iface->current_mode) {
 653                 /*
 654                  * This can happen with drivers that do not provide mode
 655                  * information and as such, cannot really use hostapd for DFS.
 656                  */
 657                 wpa_printf(MSG_DEBUG,
 658                            "DFS: No current_mode information - assume no need to perform DFS operations by hostapd");
 659                 return 1;
 660         }
 661
 662         iface->cac_started = 0;
 663
 664         do {
 665                 /* Get start (first) channel for current configuration */
 666                 start_chan_idx = dfs_get_start_chan_idx(iface,
 667                                                         &start_chan_idx1);
 668                 if (start_chan_idx == -1)
 669                         return -1;
 670
 671                 /* Get number of used channels, depend on width */
 672                 n_chans = dfs_get_used_n_chans(iface, &n_chans1);
 673
 674                 /* Setup CAC time */
 675                 iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
 676                                                      n_chans);
 677
 678                 /* Check if any of configured channels require DFS */
 679                 res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
 680                 wpa_printf(MSG_DEBUG,
 681                            "DFS %d channels required radar detection",
 682                            res);
 683                 if (!res)
 684                         return 1;
 685
 686                 /* Check if all channels are DFS available */
 687                 res = dfs_check_chans_available(iface, start_chan_idx, n_chans);
 688                 wpa_printf(MSG_DEBUG,
 689                            "DFS all channels available, (SKIP CAC): %s",
 690                            res ? "yes" : "no");
 691                 if (res)
 692                         return 1;
 693
 694                 /* Check if any of configured channels is unavailable */
 695                 res = dfs_check_chans_unavailable(iface, start_chan_idx,
 696                                                   n_chans);
 697                 wpa_printf(MSG_DEBUG, "DFS %d chans unavailable - choose other channel: %s",
 698                            res, res ? "yes": "no");
 699                 if (res) {
 700                         int sec = 0;
 701                         u8 cf1 = 0, cf2 = 0;
 702
 703                         channel = dfs_get_valid_channel(iface, &sec, &cf1, &cf2,
 704                                                         skip_radar);
 705                         if (!channel) {
 706                                 wpa_printf(MSG_ERROR, "could not get valid channel");
 707                                 hostapd_set_state(iface, HAPD_IFACE_DFS);
 708                                 return 0;
 709                         }
 710
 711                         iface->freq = channel->freq;
 712                         iface->conf->channel = channel->chan;
 713                         iface->conf->secondary_channel = sec;
 714                         iface->conf->vht_oper_centr_freq_seg0_idx = cf1;
 715                         iface->conf->vht_oper_centr_freq_seg1_idx = cf2;
 716                 }
 717         } while (res);
 718
 719         /* Finally start CAC */
 720         hostapd_set_state(iface, HAPD_IFACE_DFS);
 721         wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz", iface->freq);
 722         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
 723                 "freq=%d chan=%d sec_chan=%d, width=%d, seg0=%d, seg1=%d, cac_time=%ds",
 724                 iface->freq,
 725                 iface->conf->channel, iface->conf->secondary_channel,
 726                 iface->conf->vht_oper_chwidth,
 727                 iface->conf->vht_oper_centr_freq_seg0_idx,
 728                 iface->conf->vht_oper_centr_freq_seg1_idx,
 729                 iface->dfs_cac_ms / 1000);
 730
 731         res = hostapd_start_dfs_cac(iface, iface->conf->hw_mode,
 732                                     iface->freq,
 733                                     iface->conf->channel,
 734                                     iface->conf->ieee80211n,
 735                                     iface->conf->ieee80211ac,
 736                                     iface->conf->secondary_channel,
 737                                     iface->conf->vht_oper_chwidth,
 738                                     iface->conf->vht_oper_centr_freq_seg0_idx,
 739                                     iface->conf->vht_oper_centr_freq_seg1_idx);
 740
 741         if (res) {
 742                 wpa_printf(MSG_ERROR, "DFS start_dfs_cac() failed, %d", res);
 743                 return -1;
 744         }
 745
 746         return 0;
 747 }
 748
 749
 750 int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
 751                              int ht_enabled, int chan_offset, int chan_width,
 752                              int cf1, int cf2)
 753 {
 754         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
 755                 "success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
 756                 success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
 757
 758         if (success) {
 759                 /* Complete iface/ap configuration */
 760                 if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) {
 761                         /* Complete AP configuration for the first bring up. */
 762                         if (iface->state != HAPD_IFACE_ENABLED)
 763                                 hostapd_setup_interface_complete(iface, 0);
 764                         else
 765                                 iface->cac_started = 0;
 766                 } else {
 767                         set_dfs_state(iface, freq, ht_enabled, chan_offset,
 768                                       chan_width, cf1, cf2,
 769                                       HOSTAPD_CHAN_DFS_AVAILABLE);
 770                         iface->cac_started = 0;
 771                         hostapd_setup_interface_complete(iface, 0);
 772                 }
 773         }
 774
 775         return 0;
 776 }
 777
 778
 779 static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
 780 {
 781         struct hostapd_channel_data *channel;
 782         int secondary_channel;
 783         u8 vht_oper_centr_freq_seg0_idx = 0;
 784         u8 vht_oper_centr_freq_seg1_idx = 0;
 785         int skip_radar = 0;
 786         int err = 1;
 787
 788         /* Radar detected during active CAC */
 789         iface->cac_started = 0;
 790         channel = dfs_get_valid_channel(iface, &secondary_channel,
 791                                         &vht_oper_centr_freq_seg0_idx,
 792                                         &vht_oper_centr_freq_seg1_idx,
 793                                         skip_radar);
 794
 795         if (!channel) {
 796                 wpa_printf(MSG_ERROR, "No valid channel available");
 797                 return err;
 798         }
 799
 800         wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
 801                    channel->chan);
 802         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
 803                 "freq=%d chan=%d sec_chan=%d", channel->freq,
 804                 channel->chan, secondary_channel);
 805
 806         iface->freq = channel->freq;
 807         iface->conf->channel = channel->chan;
 808         iface->conf->secondary_channel = secondary_channel;
 809         iface->conf->vht_oper_centr_freq_seg0_idx =
 810                 vht_oper_centr_freq_seg0_idx;
 811         iface->conf->vht_oper_centr_freq_seg1_idx =
 812                 vht_oper_centr_freq_seg1_idx;
 813         err = 0;
 814
 815         hostapd_setup_interface_complete(iface, err);
 816         return err;
 817 }
 818
 819
 820 static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
 821 {
 822         struct hostapd_channel_data *channel;
 823         int secondary_channel;
 824         u8 vht_oper_centr_freq_seg0_idx;
 825         u8 vht_oper_centr_freq_seg1_idx;
 826         int skip_radar = 1;
 827         struct csa_settings csa_settings;
 828         unsigned int i;
 829         int err = 1;
 830
 831         wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
 832                    __func__, iface->cac_started ? "yes" : "no",
 833                    hostapd_csa_in_progress(iface) ? "yes" : "no");
 834
 835         /* Check if CSA in progress */
 836         if (hostapd_csa_in_progress(iface))
 837                 return 0;
 838
 839         /* Check if active CAC */
 840         if (iface->cac_started)
 841                 return hostapd_dfs_start_channel_switch_cac(iface);
 842
 843         /* Perform channel switch/CSA */
 844         channel = dfs_get_valid_channel(iface, &secondary_channel,
 845                                         &vht_oper_centr_freq_seg0_idx,
 846                                         &vht_oper_centr_freq_seg1_idx,
 847                                         skip_radar);
 848
 849         if (!channel) {
 850                 /*
 851                  * If there is no channel to switch immediately to, check if
 852                  * there is another channel where we can switch even if it
 853                  * requires to perform a CAC first.
 854                  */
 855                 skip_radar = 0;
 856                 channel = dfs_get_valid_channel(iface, &secondary_channel,
 857                                                 &vht_oper_centr_freq_seg0_idx,
 858                                                 &vht_oper_centr_freq_seg1_idx,
 859                                                 skip_radar);
 860                 if (!channel) {
 861                         wpa_printf(MSG_INFO,
 862                                    "%s: no DFS channels left, waiting for NOP to finish",
 863                                    __func__);
 864                         return err;
 865                 }
 866
 867                 iface->freq = channel->freq;
 868                 iface->conf->channel = channel->chan;
 869                 iface->conf->secondary_channel = secondary_channel;
 870                 iface->conf->vht_oper_centr_freq_seg0_idx =
 871                         vht_oper_centr_freq_seg0_idx;
 872                 iface->conf->vht_oper_centr_freq_seg1_idx =
 873                         vht_oper_centr_freq_seg1_idx;
 874
 875                 hostapd_disable_iface(iface);
 876                 hostapd_enable_iface(iface);
 877                 return 0;
 878         }
 879
 880         wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
 881                    channel->chan);
 882         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
 883                 "freq=%d chan=%d sec_chan=%d", channel->freq,
 884                 channel->chan, secondary_channel);
 885
 886         /* Setup CSA request */
 887         os_memset(&csa_settings, 0, sizeof(csa_settings));
 888         csa_settings.cs_count = 5;
 889         csa_settings.block_tx = 1;
 890         err = hostapd_set_freq_params(&csa_settings.freq_params,
 891                                       iface->conf->hw_mode,
 892                                       channel->freq,
 893                                       channel->chan,
 894                                       iface->conf->ieee80211n,
 895                                       iface->conf->ieee80211ac,
 896                                       secondary_channel,
 897                                       iface->conf->vht_oper_chwidth,
 898                                       vht_oper_centr_freq_seg0_idx,
 899                                       vht_oper_centr_freq_seg1_idx,
 900                                       iface->current_mode->vht_capab);
 901
 902         if (err) {
 903                 wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
 904                 hostapd_disable_iface(iface);
 905                 return err;
 906         }
 907
 908         for (i = 0; i < iface->num_bss; i++) {
 909                 err = hostapd_switch_channel(iface->bss[i], &csa_settings);
 910                 if (err)
 911                         break;
 912         }
 913
 914         if (err) {
 915                 wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
 916                            err);
 917                 iface->freq = channel->freq;
 918                 iface->conf->channel = channel->chan;
 919                 iface->conf->secondary_channel = secondary_channel;
 920                 iface->conf->vht_oper_centr_freq_seg0_idx =
 921                         vht_oper_centr_freq_seg0_idx;
 922                 iface->conf->vht_oper_centr_freq_seg1_idx =
 923                         vht_oper_centr_freq_seg1_idx;
 924
 925                 hostapd_disable_iface(iface);
 926                 hostapd_enable_iface(iface);
 927                 return 0;
 928         }
 929
 930         /* Channel configuration will be updated once CSA completes and
 931          * ch_switch_notify event is received */
 932
 933         wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
 934         return 0;
 935 }
 936
 937
 938 int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
 939                                int ht_enabled, int chan_offset, int chan_width,
 940                                int cf1, int cf2)
 941 {
 942         int res;
 943
 944         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
 945                 "freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
 946                 freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
 947
 948         /* Proceed only if DFS is not offloaded to the driver */
 949         if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
 950                 return 0;
 951
 952         if (!iface->conf->ieee80211h)
 953                 return 0;
 954
 955         /* mark radar frequency as invalid */
 956         set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
 957                       cf1, cf2, HOSTAPD_CHAN_DFS_UNAVAILABLE);
 958
 959         /* Skip if reported radar event not overlapped our channels */
 960         res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
 961         if (!res)
 962                 return 0;
 963
 964         /* radar detected while operating, switch the channel. */
 965         res = hostapd_dfs_start_channel_switch(iface);
 966
 967         return res;
 968 }
 969
 970
 971 int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
 972                              int ht_enabled, int chan_offset, int chan_width,
 973                              int cf1, int cf2)
 974 {
 975         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
 976                 "freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
 977                 freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
 978
 979         /* Proceed only if DFS is not offloaded to the driver */
 980         if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
 981                 return 0;
 982
 983         /* TODO add correct implementation here */
 984         set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
 985                       cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
 986
 987         /* Handle cases where all channels were initially unavailable */
 988         if (iface->state == HAPD_IFACE_DFS && !iface->cac_started)
 989                 hostapd_handle_dfs(iface);
 990
 991         return 0;
 992 }
 993
 994
 995 int hostapd_is_dfs_required(struct hostapd_iface *iface)
 996 {
 997         int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
 998
 999         if (!iface->conf->ieee80211h || !iface->current_mode ||
1000             iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
1001                 return 0;
1002
1003         /* Get start (first) channel for current configuration */
1004         start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
1005         if (start_chan_idx == -1)
1006                 return -1;
1007
1008         /* Get number of used channels, depend on width */
1009         n_chans = dfs_get_used_n_chans(iface, &n_chans1);
1010
1011         /* Check if any of configured channels require DFS */
1012         res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
1013         if (res)
1014                 return res;
1015         if (start_chan_idx1 >= 0 && n_chans1 > 0)
1016                 res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
1017         return res;
1018 }
1019
1020
1021 int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
1022                           int ht_enabled, int chan_offset, int chan_width,
1023                           int cf1, int cf2)
1024 {
1025         wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
1026                 "freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
1027                 "seg1=%d cac_time=%ds",
1028                 freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2, 60);
1029         iface->cac_started = 1;
1030         return 0;
1031 }
1032
1033
1034 /*
1035  * Main DFS handler for offloaded case.
1036  * 2 - continue channel/AP setup for non-DFS channel
1037  * 1 - continue channel/AP setup for DFS channel
1038  * 0 - channel/AP setup will be continued after CAC
1039  * -1 - hit critical error
1040  */
1041 int hostapd_handle_dfs_offload(struct hostapd_iface *iface)
1042 {
1043         wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1044                    __func__, iface->cac_started);
1045
1046         /*
1047          * If DFS has already been started, then we are being called from a
1048          * callback to continue AP/channel setup. Reset the CAC start flag and
1049          * return.
1050          */
1051         if (iface->cac_started) {
1052                 wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1053                            __func__, iface->cac_started);
1054                 iface->cac_started = 0;
1055                 return 1;
1056         }
1057
1058         if (ieee80211_is_dfs(iface->freq)) {
1059                 wpa_printf(MSG_DEBUG, "%s: freq %d MHz requires DFS",
1060                            __func__, iface->freq);
1061                 return 0;
1062         }
1063
1064         wpa_printf(MSG_DEBUG,
1065                    "%s: freq %d MHz does not require DFS. Continue channel/AP setup",
1066                    __func__, iface->freq);
1067         return 2;
1068 }