hostapd/hw_features.c

   1 /*
   2  * hostapd / Hardware feature query and different modes
   3  * Copyright 2002-2003, Instant802 Networks, Inc.
   4  * Copyright 2005-2006, Devicescape Software, Inc.
   5  * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * Alternatively, this software may be distributed under the terms of BSD
  12  * license.
  13  *
  14  * See README and COPYING for more details.
  15  */
  16
  17 #include "includes.h"
  18
  19 #include "hostapd.h"
  20 #include "ieee802_11_defs.h"
  21 #include "ieee802_11_common.h"
  22 #include "eloop.h"
  23 #include "hw_features.h"
  24 #include "driver_i.h"
  25 #include "config.h"
  26
  27
  28 void hostapd_free_hw_features(struct hostapd_hw_modes *hw_features,
  29                               size_t num_hw_features)
  30 {
  31         size_t i;
  32
  33         if (hw_features == NULL)
  34                 return;
  35
  36         for (i = 0; i < num_hw_features; i++) {
  37                 os_free(hw_features[i].channels);
  38                 os_free(hw_features[i].rates);
  39         }
  40
  41         os_free(hw_features);
  42 }
  43
  44
  45 int hostapd_get_hw_features(struct hostapd_iface *iface)
  46 {
  47         struct hostapd_data *hapd = iface->bss[0];
  48         int ret = 0, i, j;
  49         u16 num_modes, flags;
  50         struct hostapd_hw_modes *modes;
  51
  52         if (hostapd_drv_none(hapd))
  53                 return -1;
  54         modes = hostapd_get_hw_feature_data(hapd, &num_modes, &flags);
  55         if (modes == NULL) {
  56                 hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
  57                                HOSTAPD_LEVEL_DEBUG,
  58                                "Fetching hardware channel/rate support not "
  59                                "supported.");
  60                 return -1;
  61         }
  62
  63         iface->hw_flags = flags;
  64
  65         hostapd_free_hw_features(iface->hw_features, iface->num_hw_features);
  66         iface->hw_features = modes;
  67         iface->num_hw_features = num_modes;
  68
  69         for (i = 0; i < num_modes; i++) {
  70                 struct hostapd_hw_modes *feature = &modes[i];
  71                 /* set flag for channels we can use in current regulatory
  72                  * domain */
  73                 for (j = 0; j < feature->num_channels; j++) {
  74                         /*
  75                          * Disable all channels that are marked not to allow
  76                          * IBSS operation or active scanning. In addition,
  77                          * disable all channels that require radar detection,
  78                          * since that (in addition to full DFS) is not yet
  79                          * supported.
  80                          */
  81                         if (feature->channels[j].flag &
  82                             (HOSTAPD_CHAN_NO_IBSS |
  83                              HOSTAPD_CHAN_PASSIVE_SCAN |
  84                              HOSTAPD_CHAN_RADAR))
  85                                 feature->channels[j].flag |=
  86                                         HOSTAPD_CHAN_DISABLED;
  87                         if (feature->channels[j].flag & HOSTAPD_CHAN_DISABLED)
  88                                 continue;
  89                         wpa_printf(MSG_MSGDUMP, "Allowed channel: mode=%d "
  90                                    "chan=%d freq=%d MHz max_tx_power=%d dBm",
  91                                    feature->mode,
  92                                    feature->channels[j].chan,
  93                                    feature->channels[j].freq,
  94                                    feature->channels[j].max_tx_power);
  95                 }
  96         }
  97
  98         return ret;
  99 }
 100
 101
 102 static int hostapd_prepare_rates(struct hostapd_data *hapd,
 103                                  struct hostapd_hw_modes *mode)
 104 {
 105         int i, num_basic_rates = 0;
 106         int basic_rates_a[] = { 60, 120, 240, -1 };
 107         int basic_rates_b[] = { 10, 20, -1 };
 108         int basic_rates_g[] = { 10, 20, 55, 110, -1 };
 109         int *basic_rates;
 110
 111         if (hapd->iconf->basic_rates)
 112                 basic_rates = hapd->iconf->basic_rates;
 113         else switch (mode->mode) {
 114         case HOSTAPD_MODE_IEEE80211A:
 115                 basic_rates = basic_rates_a;
 116                 break;
 117         case HOSTAPD_MODE_IEEE80211B:
 118                 basic_rates = basic_rates_b;
 119                 break;
 120         case HOSTAPD_MODE_IEEE80211G:
 121                 basic_rates = basic_rates_g;
 122                 break;
 123         default:
 124                 return -1;
 125         }
 126
 127         if (hostapd_set_rate_sets(hapd, hapd->iconf->supported_rates,
 128                                   basic_rates, mode->mode)) {
 129                 wpa_printf(MSG_ERROR, "Failed to update rate sets in kernel "
 130                            "module");
 131         }
 132
 133         os_free(hapd->iface->current_rates);
 134         hapd->iface->num_rates = 0;
 135
 136         hapd->iface->current_rates =
 137                 os_malloc(mode->num_rates * sizeof(struct hostapd_rate_data));
 138         if (!hapd->iface->current_rates) {
 139                 wpa_printf(MSG_ERROR, "Failed to allocate memory for rate "
 140                            "table.");
 141                 return -1;
 142         }
 143
 144         for (i = 0; i < mode->num_rates; i++) {
 145                 struct hostapd_rate_data *rate;
 146
 147                 if (hapd->iconf->supported_rates &&
 148                     !hostapd_rate_found(hapd->iconf->supported_rates,
 149                                         mode->rates[i].rate))
 150                         continue;
 151
 152                 rate = &hapd->iface->current_rates[hapd->iface->num_rates];
 153                 os_memcpy(rate, &mode->rates[i],
 154                           sizeof(struct hostapd_rate_data));
 155                 if (hostapd_rate_found(basic_rates, rate->rate)) {
 156                         rate->flags |= HOSTAPD_RATE_BASIC;
 157                         num_basic_rates++;
 158                 } else
 159                         rate->flags &= ~HOSTAPD_RATE_BASIC;
 160                 wpa_printf(MSG_DEBUG, "RATE[%d] rate=%d flags=0x%x",
 161                            hapd->iface->num_rates, rate->rate, rate->flags);
 162                 hapd->iface->num_rates++;
 163         }
 164
 165         if (hapd->iface->num_rates == 0 || num_basic_rates == 0) {
 166                 wpa_printf(MSG_ERROR, "No rates remaining in supported/basic "
 167                            "rate sets (%d,%d).",
 168                            hapd->iface->num_rates, num_basic_rates);
 169                 return -1;
 170         }
 171
 172         return 0;
 173 }
 174
 175
 176 #ifdef CONFIG_IEEE80211N
 177 static int ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface *iface)
 178 {
 179         int sec_chan, ok, j, first;
 180         int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
 181                           184, 192 };
 182         size_t k;
 183
 184         if (!iface->conf->secondary_channel)
 185                 return 1; /* HT40 not used */
 186
 187         sec_chan = iface->conf->channel + iface->conf->secondary_channel * 4;
 188         wpa_printf(MSG_DEBUG, "HT40: control channel: %d  "
 189                    "secondary channel: %d",
 190                    iface->conf->channel, sec_chan);
 191
 192         /* Verify that HT40 secondary channel is an allowed 20 MHz
 193          * channel */
 194         ok = 0;
 195         for (j = 0; j < iface->current_mode->num_channels; j++) {
 196                 struct hostapd_channel_data *chan =
 197                         &iface->current_mode->channels[j];
 198                 if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
 199                     chan->chan == sec_chan) {
 200                         ok = 1;
 201                         break;
 202                 }
 203         }
 204         if (!ok) {
 205                 wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
 206                            sec_chan);
 207                 return 0;
 208         }
 209
 210         /*
 211          * Verify that HT40 primary,secondary channel pair is allowed per
 212          * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
 213          * 2.4 GHz rules allow all cases where the secondary channel fits into
 214          * the list of allowed channels (already checked above).
 215          */
 216         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
 217                 return 1;
 218
 219         if (iface->conf->secondary_channel > 0)
 220                 first = iface->conf->channel;
 221         else
 222                 first = sec_chan;
 223
 224         ok = 0;
 225         for (k = 0; k < sizeof(allowed) / sizeof(allowed[0]); k++) {
 226                 if (first == allowed[k]) {
 227                         ok = 1;
 228                         break;
 229                 }
 230         }
 231         if (!ok) {
 232                 wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
 233                            iface->conf->channel,
 234                            iface->conf->secondary_channel);
 235                 return 0;
 236         }
 237
 238         return 1;
 239 }
 240
 241
 242 static void ieee80211n_switch_pri_sec(struct hostapd_iface *iface)
 243 {
 244         if (iface->conf->secondary_channel > 0) {
 245                 iface->conf->channel += 4;
 246                 iface->conf->secondary_channel = -1;
 247         } else {
 248                 iface->conf->channel -= 4;
 249                 iface->conf->secondary_channel = 1;
 250         }
 251 }
 252
 253
 254 static void ieee80211n_get_pri_sec_chan(struct wpa_scan_res *bss,
 255                                         int *pri_chan, int *sec_chan)
 256 {
 257         struct ieee80211_ht_operation *oper;
 258         struct ieee802_11_elems elems;
 259
 260         *pri_chan = *sec_chan = 0;
 261
 262         ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
 263         if (elems.ht_operation &&
 264             elems.ht_operation_len >= sizeof(*oper)) {
 265                 oper = (struct ieee80211_ht_operation *) elems.ht_operation;
 266                 *pri_chan = oper->control_chan;
 267                 if (oper->ht_param & HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH) {
 268                         if (oper->ht_param &
 269                             HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
 270                                 *sec_chan = *pri_chan + 4;
 271                         else if (oper->ht_param &
 272                                  HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
 273                                 *sec_chan = *pri_chan - 4;
 274                 }
 275         }
 276 }
 277
 278
 279 static int ieee80211n_check_40mhz_5g(struct hostapd_iface *iface,
 280                                      struct wpa_scan_results *scan_res)
 281 {
 282         int pri_chan, sec_chan, pri_freq, sec_freq, pri_bss, sec_bss;
 283         int bss_pri_chan, bss_sec_chan;
 284         size_t i;
 285         int match;
 286
 287         pri_chan = iface->conf->channel;
 288         sec_chan = iface->conf->secondary_channel * 4;
 289         pri_freq = hostapd_hw_get_freq(iface->bss[0], pri_chan);
 290         if (iface->conf->secondary_channel > 0)
 291                 sec_freq = pri_freq + 20;
 292         else
 293                 sec_freq = pri_freq - 20;
 294
 295         /*
 296          * Switch PRI/SEC channels if Beacons were detected on selected SEC
 297          * channel, but not on selected PRI channel.
 298          */
 299         pri_bss = sec_bss = 0;
 300         for (i = 0; i < scan_res->num; i++) {
 301                 struct wpa_scan_res *bss = scan_res->res[i];
 302                 if (bss->freq == pri_freq)
 303                         pri_bss++;
 304                 else if (bss->freq == sec_freq)
 305                         sec_bss++;
 306         }
 307         if (sec_bss && !pri_bss) {
 308                 wpa_printf(MSG_INFO, "Switch own primary and secondary "
 309                            "channel to get secondary channel with no Beacons "
 310                            "from other BSSes");
 311                 ieee80211n_switch_pri_sec(iface);
 312         }
 313
 314         /*
 315          * Match PRI/SEC channel with any existing HT40 BSS on the same
 316          * channels that we are about to use (if already mixed order in
 317          * existing BSSes, use own preference).
 318          */
 319         match = 0;
 320         for (i = 0; i < scan_res->num; i++) {
 321                 struct wpa_scan_res *bss = scan_res->res[i];
 322                 ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
 323                 if (pri_chan == bss_pri_chan &&
 324                     sec_chan == bss_sec_chan) {
 325                         match = 1;
 326                         break;
 327                 }
 328         }
 329         if (!match) {
 330                 for (i = 0; i < scan_res->num; i++) {
 331                         struct wpa_scan_res *bss = scan_res->res[i];
 332                         ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan,
 333                                                     &bss_sec_chan);
 334                         if (pri_chan == bss_sec_chan &&
 335                             sec_chan == bss_pri_chan) {
 336                                 wpa_printf(MSG_INFO, "Switch own primary and "
 337                                            "secondary channel due to BSS "
 338                                            "overlap with " MACSTR,
 339                                            MAC2STR(bss->bssid));
 340                                 ieee80211n_switch_pri_sec(iface);
 341                                 break;
 342                         }
 343                 }
 344         }
 345
 346         return 1;
 347 }
 348
 349
 350 static int ieee80211n_check_40mhz_2g4(struct hostapd_iface *iface,
 351                                       struct wpa_scan_results *scan_res)
 352 {
 353         int pri_freq, sec_freq;
 354         int affected_start, affected_end;
 355         size_t i;
 356
 357         pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
 358         if (iface->conf->secondary_channel > 0)
 359                 sec_freq = pri_freq + 20;
 360         else
 361                 sec_freq = pri_freq - 20;
 362         affected_start = (pri_freq + sec_freq) / 2 - 25;
 363         affected_end = (pri_freq + sec_freq) / 2 + 25;
 364         wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
 365                    affected_start, affected_end);
 366         for (i = 0; i < scan_res->num; i++) {
 367                 struct wpa_scan_res *bss = scan_res->res[i];
 368                 int pri = bss->freq;
 369                 int sec = pri;
 370                 int sec_chan, pri_chan;
 371
 372                 ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
 373
 374                 if (sec_chan) {
 375                         if (sec_chan < pri_chan)
 376                                 sec = pri - 20;
 377                         else
 378                                 sec = pri + 20;
 379                 }
 380
 381                 if ((pri < affected_start || pri > affected_end) &&
 382                     (sec < affected_start || sec > affected_end))
 383                         continue; /* not within affected channel range */
 384
 385                 wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
 386                            " freq=%d pri=%d sec=%d",
 387                            MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
 388
 389                 if (sec_chan) {
 390                         if (pri_freq != pri || sec_freq != sec) {
 391                                 wpa_printf(MSG_DEBUG, "40 MHz pri/sec "
 392                                            "mismatch with BSS " MACSTR
 393                                            " <%d,%d> (chan=%d%c) vs. <%d,%d>",
 394                                            MAC2STR(bss->bssid),
 395                                            pri, sec, pri_chan,
 396                                            sec > pri ? '+' : '-',
 397                                            pri_freq, sec_freq);
 398                                 return 0;
 399                         }
 400                 }
 401
 402                 /* TODO: 40 MHz intolerant */
 403         }
 404
 405         return 1;
 406 }
 407
 408
 409 static void ieee80211n_check_scan(struct hostapd_iface *iface)
 410 {
 411         struct wpa_scan_results *scan_res;
 412         int oper40;
 413
 414         /* Check list of neighboring BSSes (from scan) to see whether 40 MHz is
 415          * allowed per IEEE 802.11n/D7.0, 11.14.3.2 */
 416
 417         iface->scan_cb = NULL;
 418
 419         scan_res = hostapd_driver_get_scan_results(iface->bss[0]);
 420         if (scan_res == NULL) {
 421                 hostapd_setup_interface_complete(iface, 1);
 422                 return;
 423         }
 424
 425         if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A)
 426                 oper40 = ieee80211n_check_40mhz_5g(iface, scan_res);
 427         else
 428                 oper40 = ieee80211n_check_40mhz_2g4(iface, scan_res);
 429         wpa_scan_results_free(scan_res);
 430
 431         if (!oper40) {
 432                 wpa_printf(MSG_INFO, "20/40 MHz operation not permitted on "
 433                            "channel pri=%d sec=%d based on overlapping BSSes",
 434                            iface->conf->channel,
 435                            iface->conf->channel +
 436                            iface->conf->secondary_channel * 4);
 437                 iface->conf->secondary_channel = 0;
 438                 iface->conf->ht_capab &= ~HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET;
 439         }
 440
 441         hostapd_setup_interface_complete(iface, 0);
 442 }
 443
 444
 445 static int ieee80211n_check_40mhz(struct hostapd_iface *iface)
 446 {
 447         struct wpa_driver_scan_params params;
 448
 449         if (!iface->conf->secondary_channel)
 450                 return 0; /* HT40 not used */
 451
 452         wpa_printf(MSG_DEBUG, "Scan for neighboring BSSes prior to enabling "
 453                    "40 MHz channel");
 454         os_memset(&params, 0, sizeof(params));
 455         /* TODO: scan only the needed frequency */
 456         if (hostapd_driver_scan(iface->bss[0], &params) < 0) {
 457                 wpa_printf(MSG_ERROR, "Failed to request a scan of "
 458                            "neighboring BSSes");
 459                 return -1;
 460         }
 461
 462         iface->scan_cb = ieee80211n_check_scan;
 463         return 1;
 464 }
 465
 466
 467 static int ieee80211n_supported_ht_capab(struct hostapd_iface *iface)
 468 {
 469         u16 hw = iface->current_mode->ht_capab;
 470         u16 conf = iface->conf->ht_capab;
 471
 472         if (!iface->conf->ieee80211n)
 473                 return 1;
 474
 475         if ((conf & HT_CAP_INFO_LDPC_CODING_CAP) &&
 476             !(hw & HT_CAP_INFO_LDPC_CODING_CAP)) {
 477                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 478                            "HT capability [LDPC]");
 479                 return 0;
 480         }
 481
 482         if ((conf & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
 483             !(hw & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
 484                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 485                            "HT capability [HT40*]");
 486                 return 0;
 487         }
 488
 489         if ((conf & HT_CAP_INFO_SMPS_MASK) != (hw & HT_CAP_INFO_SMPS_MASK) &&
 490             (conf & HT_CAP_INFO_SMPS_MASK) != HT_CAP_INFO_SMPS_DISABLED) {
 491                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 492                            "HT capability [SMPS-*]");
 493                 return 0;
 494         }
 495
 496         if ((conf & HT_CAP_INFO_GREEN_FIELD) &&
 497             !(hw & HT_CAP_INFO_GREEN_FIELD)) {
 498                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 499                            "HT capability [GF]");
 500                 return 0;
 501         }
 502
 503         if ((conf & HT_CAP_INFO_SHORT_GI20MHZ) &&
 504             !(hw & HT_CAP_INFO_SHORT_GI20MHZ)) {
 505                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 506                            "HT capability [SHORT-GI-20]");
 507                 return 0;
 508         }
 509
 510         if ((conf & HT_CAP_INFO_SHORT_GI40MHZ) &&
 511             !(hw & HT_CAP_INFO_SHORT_GI40MHZ)) {
 512                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 513                            "HT capability [SHORT-GI-40]");
 514                 return 0;
 515         }
 516
 517         if ((conf & HT_CAP_INFO_TX_STBC) && !(hw & HT_CAP_INFO_TX_STBC)) {
 518                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 519                            "HT capability [TX-STBC]");
 520                 return 0;
 521         }
 522
 523         if ((conf & HT_CAP_INFO_RX_STBC_MASK) >
 524             (hw & HT_CAP_INFO_RX_STBC_MASK)) {
 525                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 526                            "HT capability [RX-STBC*]");
 527                 return 0;
 528         }
 529
 530         if ((conf & HT_CAP_INFO_DELAYED_BA) &&
 531             !(hw & HT_CAP_INFO_DELAYED_BA)) {
 532                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 533                            "HT capability [DELAYED-BA]");
 534                 return 0;
 535         }
 536
 537         if ((conf & HT_CAP_INFO_MAX_AMSDU_SIZE) &&
 538             !(hw & HT_CAP_INFO_MAX_AMSDU_SIZE)) {
 539                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 540                            "HT capability [MAX-AMSDU-7935]");
 541                 return 0;
 542         }
 543
 544         if ((conf & HT_CAP_INFO_DSSS_CCK40MHZ) &&
 545             !(hw & HT_CAP_INFO_DSSS_CCK40MHZ)) {
 546                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 547                            "HT capability [DSSS_CCK-40]");
 548                 return 0;
 549         }
 550
 551         if ((conf & HT_CAP_INFO_PSMP_SUPP) && !(hw & HT_CAP_INFO_PSMP_SUPP)) {
 552                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 553                            "HT capability [PSMP]");
 554                 return 0;
 555         }
 556
 557         if ((conf & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT) &&
 558             !(hw & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT)) {
 559                 wpa_printf(MSG_ERROR, "Driver does not support configured "
 560                            "HT capability [LSIG-TXOP-PROT]");
 561                 return 0;
 562         }
 563
 564         return 1;
 565 }
 566
 567 #endif /* CONFIG_IEEE80211N */
 568
 569
 570 int hostapd_check_ht_capab(struct hostapd_iface *iface)
 571 {
 572 #ifdef CONFIG_IEEE80211N
 573         int ret;
 574         ret = ieee80211n_check_40mhz(iface);
 575         if (ret)
 576                 return ret;
 577         if (!ieee80211n_allowed_ht40_channel_pair(iface))
 578                 return -1;
 579         if (!ieee80211n_supported_ht_capab(iface))
 580                 return -1;
 581 #endif /* CONFIG_IEEE80211N */
 582
 583         return 0;
 584 }
 585
 586
 587 /**
 588  * hostapd_select_hw_mode - Select the hardware mode
 589  * @iface: Pointer to interface data.
 590  * Returns: 0 on success, -1 on failure
 591  *
 592  * Sets up the hardware mode, channel, rates, and passive scanning
 593  * based on the configuration.
 594  */
 595 int hostapd_select_hw_mode(struct hostapd_iface *iface)
 596 {
 597         int i, j, ok;
 598
 599         if (iface->num_hw_features < 1)
 600                 return -1;
 601
 602         iface->current_mode = NULL;
 603         for (i = 0; i < iface->num_hw_features; i++) {
 604                 struct hostapd_hw_modes *mode = &iface->hw_features[i];
 605                 if (mode->mode == iface->conf->hw_mode) {
 606                         iface->current_mode = mode;
 607                         break;
 608                 }
 609         }
 610
 611         if (iface->current_mode == NULL) {
 612                 wpa_printf(MSG_ERROR, "Hardware does not support configured "
 613                            "mode");
 614                 hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
 615                                HOSTAPD_LEVEL_WARNING,
 616                                "Hardware does not support configured mode "
 617                                "(%d)", (int) iface->conf->hw_mode);
 618                 return -1;
 619         }
 620
 621         ok = 0;
 622         for (j = 0; j < iface->current_mode->num_channels; j++) {
 623                 struct hostapd_channel_data *chan =
 624                         &iface->current_mode->channels[j];
 625                 if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
 626                     (chan->chan == iface->conf->channel)) {
 627                         ok = 1;
 628                         break;
 629                 }
 630         }
 631         if (iface->conf->channel == 0) {
 632                 /* TODO: could request a scan of neighboring BSSes and select
 633                  * the channel automatically */
 634                 wpa_printf(MSG_ERROR, "Channel not configured "
 635                            "(hw_mode/channel in hostapd.conf)");
 636                 return -1;
 637         }
 638         if (ok == 0 && iface->conf->channel != 0) {
 639                 hostapd_logger(iface->bss[0], NULL,
 640                                HOSTAPD_MODULE_IEEE80211,
 641                                HOSTAPD_LEVEL_WARNING,
 642                                "Configured channel (%d) not found from the "
 643                                "channel list of current mode (%d) %s",
 644                                iface->conf->channel,
 645                                iface->current_mode->mode,
 646                                hostapd_hw_mode_txt(iface->current_mode->mode));
 647                 iface->current_mode = NULL;
 648         }
 649
 650         if (iface->current_mode == NULL) {
 651                 hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
 652                                HOSTAPD_LEVEL_WARNING,
 653                                "Hardware does not support configured channel");
 654                 return -1;
 655         }
 656
 657         if (hostapd_prepare_rates(iface->bss[0], iface->current_mode)) {
 658                 wpa_printf(MSG_ERROR, "Failed to prepare rates table.");
 659                 hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
 660                                            HOSTAPD_LEVEL_WARNING,
 661                                            "Failed to prepare rates table.");
 662                 return -1;
 663         }
 664
 665         return 0;
 666 }
 667
 668
 669 const char * hostapd_hw_mode_txt(int mode)
 670 {
 671         switch (mode) {
 672         case HOSTAPD_MODE_IEEE80211A:
 673                 return "IEEE 802.11a";
 674         case HOSTAPD_MODE_IEEE80211B:
 675                 return "IEEE 802.11b";
 676         case HOSTAPD_MODE_IEEE80211G:
 677                 return "IEEE 802.11g";
 678         default:
 679                 return "UNKNOWN";
 680         }
 681 }
 682
 683
 684 int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
 685 {
 686         int i;
 687
 688         if (!hapd->iface->current_mode)
 689                 return 0;
 690
 691         for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
 692                 struct hostapd_channel_data *ch =
 693                         &hapd->iface->current_mode->channels[i];
 694                 if (ch->chan == chan)
 695                         return ch->freq;
 696         }
 697
 698         return 0;
 699 }
 700
 701
 702 int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
 703 {
 704         int i;
 705
 706         if (!hapd->iface->current_mode)
 707                 return 0;
 708
 709         for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
 710                 struct hostapd_channel_data *ch =
 711                         &hapd->iface->current_mode->channels[i];
 712                 if (ch->freq == freq)
 713                         return ch->chan;
 714         }
 715
 716         return 0;
 717 }