src/common/hw_features_common.c

   1 /*
   2  * Common hostapd/wpa_supplicant HW features
   3  * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 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 "includes.h"
  11
  12 #include "common.h"
  13 #include "defs.h"
  14 #include "ieee802_11_defs.h"
  15 #include "ieee802_11_common.h"
  16 #include "hw_features_common.h"
  17
  18
  19 struct hostapd_channel_data * hw_get_channel_chan(struct hostapd_hw_modes *mode,
  20                                                   int chan, int *freq)
  21 {
  22         int i;
  23
  24         if (freq)
  25                 *freq = 0;
  26
  27         if (!mode)
  28                 return NULL;
  29
  30         for (i = 0; i < mode->num_channels; i++) {
  31                 struct hostapd_channel_data *ch = &mode->channels[i];
  32                 if (ch->chan == chan) {
  33                         if (freq)
  34                                 *freq = ch->freq;
  35                         return ch;
  36                 }
  37         }
  38
  39         return NULL;
  40 }
  41
  42
  43 struct hostapd_channel_data * hw_get_channel_freq(struct hostapd_hw_modes *mode,
  44                                                   int freq, int *chan)
  45 {
  46         int i;
  47
  48         if (chan)
  49                 *chan = 0;
  50
  51         if (!mode)
  52                 return NULL;
  53
  54         for (i = 0; i < mode->num_channels; i++) {
  55                 struct hostapd_channel_data *ch = &mode->channels[i];
  56                 if (ch->freq == freq) {
  57                         if (chan)
  58                                 *chan = ch->chan;
  59                         return ch;
  60                 }
  61         }
  62
  63         return NULL;
  64 }
  65
  66
  67 int hw_get_freq(struct hostapd_hw_modes *mode, int chan)
  68 {
  69         int freq;
  70
  71         hw_get_channel_chan(mode, chan, &freq);
  72
  73         return freq;
  74 }
  75
  76
  77 int hw_get_chan(struct hostapd_hw_modes *mode, int freq)
  78 {
  79         int chan;
  80
  81         hw_get_channel_freq(mode, freq, &chan);
  82
  83         return chan;
  84 }
  85
  86
  87 int allowed_ht40_channel_pair(struct hostapd_hw_modes *mode, int pri_chan,
  88                               int sec_chan)
  89 {
  90         int ok, first;
  91         int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 140,
  92                           149, 157, 165, 184, 192 };
  93         size_t k;
  94         struct hostapd_channel_data *p_chan, *s_chan;
  95         const int ht40_plus = pri_chan < sec_chan;
  96
  97         p_chan = hw_get_channel_chan(mode, pri_chan, NULL);
  98         if (!p_chan)
  99                 return 0;
 100
 101         if (pri_chan == sec_chan || !sec_chan) {
 102                 if (chan_pri_allowed(p_chan))
 103                         return 1; /* HT40 not used */
 104
 105                 wpa_printf(MSG_ERROR, "Channel %d is not allowed as primary",
 106                            pri_chan);
 107                 return 0;
 108         }
 109
 110         s_chan = hw_get_channel_chan(mode, sec_chan, NULL);
 111         if (!s_chan)
 112                 return 0;
 113
 114         wpa_printf(MSG_DEBUG,
 115                    "HT40: control channel: %d  secondary channel: %d",
 116                    pri_chan, sec_chan);
 117
 118         /* Verify that HT40 secondary channel is an allowed 20 MHz
 119          * channel */
 120         if ((s_chan->flag & HOSTAPD_CHAN_DISABLED) ||
 121             (ht40_plus && !(p_chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40P)) ||
 122             (!ht40_plus && !(p_chan->allowed_bw & HOSTAPD_CHAN_WIDTH_40M))) {
 123                 wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
 124                            sec_chan);
 125                 return 0;
 126         }
 127
 128         /*
 129          * Verify that HT40 primary,secondary channel pair is allowed per
 130          * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
 131          * 2.4 GHz rules allow all cases where the secondary channel fits into
 132          * the list of allowed channels (already checked above).
 133          */
 134         if (mode->mode != HOSTAPD_MODE_IEEE80211A)
 135                 return 1;
 136
 137         first = pri_chan < sec_chan ? pri_chan : sec_chan;
 138
 139         ok = 0;
 140         for (k = 0; k < ARRAY_SIZE(allowed); k++) {
 141                 if (first == allowed[k]) {
 142                         ok = 1;
 143                         break;
 144                 }
 145         }
 146         if (!ok) {
 147                 wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
 148                            pri_chan, sec_chan);
 149                 return 0;
 150         }
 151
 152         return 1;
 153 }
 154
 155
 156 void get_pri_sec_chan(struct wpa_scan_res *bss, int *pri_chan, int *sec_chan)
 157 {
 158         struct ieee80211_ht_operation *oper;
 159         struct ieee802_11_elems elems;
 160
 161         *pri_chan = *sec_chan = 0;
 162
 163         ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
 164         if (elems.ht_operation) {
 165                 oper = (struct ieee80211_ht_operation *) elems.ht_operation;
 166                 *pri_chan = oper->primary_chan;
 167                 if (oper->ht_param & HT_INFO_HT_PARAM_STA_CHNL_WIDTH) {
 168                         int sec = oper->ht_param &
 169                                 HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
 170                         if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
 171                                 *sec_chan = *pri_chan + 4;
 172                         else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
 173                                 *sec_chan = *pri_chan - 4;
 174                 }
 175         }
 176 }
 177
 178
 179 int check_40mhz_5g(struct hostapd_hw_modes *mode,
 180                    struct wpa_scan_results *scan_res, int pri_chan,
 181                    int sec_chan)
 182 {
 183         int pri_freq, sec_freq, pri_bss, sec_bss;
 184         int bss_pri_chan, bss_sec_chan;
 185         size_t i;
 186         int match;
 187
 188         if (!mode || !scan_res || !pri_chan || !sec_chan ||
 189             pri_chan == sec_chan)
 190                 return 0;
 191
 192         pri_freq = hw_get_freq(mode, pri_chan);
 193         sec_freq = hw_get_freq(mode, sec_chan);
 194
 195         /*
 196          * Switch PRI/SEC channels if Beacons were detected on selected SEC
 197          * channel, but not on selected PRI channel.
 198          */
 199         pri_bss = sec_bss = 0;
 200         for (i = 0; i < scan_res->num; i++) {
 201                 struct wpa_scan_res *bss = scan_res->res[i];
 202                 if (bss->freq == pri_freq)
 203                         pri_bss++;
 204                 else if (bss->freq == sec_freq)
 205                         sec_bss++;
 206         }
 207         if (sec_bss && !pri_bss) {
 208                 wpa_printf(MSG_INFO,
 209                            "Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes");
 210                 return 2;
 211         }
 212
 213         /*
 214          * Match PRI/SEC channel with any existing HT40 BSS on the same
 215          * channels that we are about to use (if already mixed order in
 216          * existing BSSes, use own preference).
 217          */
 218         match = 0;
 219         for (i = 0; i < scan_res->num; i++) {
 220                 struct wpa_scan_res *bss = scan_res->res[i];
 221                 get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
 222                 if (pri_chan == bss_pri_chan &&
 223                     sec_chan == bss_sec_chan) {
 224                         match = 1;
 225                         break;
 226                 }
 227         }
 228         if (!match) {
 229                 for (i = 0; i < scan_res->num; i++) {
 230                         struct wpa_scan_res *bss = scan_res->res[i];
 231                         get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
 232                         if (pri_chan == bss_sec_chan &&
 233                             sec_chan == bss_pri_chan) {
 234                                 wpa_printf(MSG_INFO, "Switch own primary and "
 235                                            "secondary channel due to BSS "
 236                                            "overlap with " MACSTR,
 237                                            MAC2STR(bss->bssid));
 238                                 return 2;
 239                         }
 240                 }
 241         }
 242
 243         return 1;
 244 }
 245
 246
 247 static int check_20mhz_bss(struct wpa_scan_res *bss, int pri_freq, int start,
 248                            int end)
 249 {
 250         struct ieee802_11_elems elems;
 251         struct ieee80211_ht_operation *oper;
 252
 253         if (bss->freq < start || bss->freq > end || bss->freq == pri_freq)
 254                 return 0;
 255
 256         ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
 257         if (!elems.ht_capabilities) {
 258                 wpa_printf(MSG_DEBUG, "Found overlapping legacy BSS: "
 259                            MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
 260                 return 1;
 261         }
 262
 263         if (elems.ht_operation) {
 264                 oper = (struct ieee80211_ht_operation *) elems.ht_operation;
 265                 if (oper->ht_param & HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK)
 266                         return 0;
 267
 268                 wpa_printf(MSG_DEBUG, "Found overlapping 20 MHz HT BSS: "
 269                            MACSTR " freq=%d", MAC2STR(bss->bssid), bss->freq);
 270                 return 1;
 271         }
 272         return 0;
 273 }
 274
 275
 276 int check_40mhz_2g4(struct hostapd_hw_modes *mode,
 277                     struct wpa_scan_results *scan_res, int pri_chan,
 278                     int sec_chan)
 279 {
 280         int pri_freq, sec_freq;
 281         int affected_start, affected_end;
 282         size_t i;
 283
 284         if (!mode || !scan_res || !pri_chan || !sec_chan ||
 285             pri_chan == sec_chan)
 286                 return 0;
 287
 288         pri_freq = hw_get_freq(mode, pri_chan);
 289         sec_freq = hw_get_freq(mode, sec_chan);
 290
 291         affected_start = (pri_freq + sec_freq) / 2 - 25;
 292         affected_end = (pri_freq + sec_freq) / 2 + 25;
 293         wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
 294                    affected_start, affected_end);
 295         for (i = 0; i < scan_res->num; i++) {
 296                 struct wpa_scan_res *bss = scan_res->res[i];
 297                 int pri = bss->freq;
 298                 int sec = pri;
 299                 struct ieee802_11_elems elems;
 300
 301                 /* Check for overlapping 20 MHz BSS */
 302                 if (check_20mhz_bss(bss, pri_freq, affected_start,
 303                                     affected_end)) {
 304                         wpa_printf(MSG_DEBUG,
 305                                    "Overlapping 20 MHz BSS is found");
 306                         return 0;
 307                 }
 308
 309                 get_pri_sec_chan(bss, &pri_chan, &sec_chan);
 310
 311                 if (sec_chan) {
 312                         if (sec_chan < pri_chan)
 313                                 sec = pri - 20;
 314                         else
 315                                 sec = pri + 20;
 316                 }
 317
 318                 if ((pri < affected_start || pri > affected_end) &&
 319                     (sec < affected_start || sec > affected_end))
 320                         continue; /* not within affected channel range */
 321
 322                 wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
 323                            " freq=%d pri=%d sec=%d",
 324                            MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
 325
 326                 if (sec_chan) {
 327                         if (pri_freq != pri || sec_freq != sec) {
 328                                 wpa_printf(MSG_DEBUG,
 329                                            "40 MHz pri/sec mismatch with BSS "
 330                                            MACSTR
 331                                            " <%d,%d> (chan=%d%c) vs. <%d,%d>",
 332                                            MAC2STR(bss->bssid),
 333                                            pri, sec, pri_chan,
 334                                            sec > pri ? '+' : '-',
 335                                            pri_freq, sec_freq);
 336                                 return 0;
 337                         }
 338                 }
 339
 340                 ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
 341                                        0);
 342                 if (elems.ht_capabilities) {
 343                         struct ieee80211_ht_capabilities *ht_cap =
 344                                 (struct ieee80211_ht_capabilities *)
 345                                 elems.ht_capabilities;
 346
 347                         if (le_to_host16(ht_cap->ht_capabilities_info) &
 348                             HT_CAP_INFO_40MHZ_INTOLERANT) {
 349                                 wpa_printf(MSG_DEBUG,
 350                                            "40 MHz Intolerant is set on channel %d in BSS "
 351                                            MACSTR, pri, MAC2STR(bss->bssid));
 352                                 return 0;
 353                         }
 354                 }
 355         }
 356
 357         return 1;
 358 }
 359
 360
 361 int hostapd_set_freq_params(struct hostapd_freq_params *data,
 362                             enum hostapd_hw_mode mode,
 363                             int freq, int channel, int ht_enabled,
 364                             int vht_enabled, int sec_channel_offset,
 365                             int oper_chwidth, int center_segment0,
 366                             int center_segment1, u32 vht_caps)
 367 {
 368         os_memset(data, 0, sizeof(*data));
 369         data->mode = mode;
 370         data->freq = freq;
 371         data->channel = channel;
 372         data->ht_enabled = ht_enabled;
 373         data->vht_enabled = vht_enabled;
 374         data->sec_channel_offset = sec_channel_offset;
 375         data->center_freq1 = freq + sec_channel_offset * 10;
 376         data->center_freq2 = 0;
 377         data->bandwidth = sec_channel_offset ? 40 : 20;
 378
 379         if (data->vht_enabled) switch (oper_chwidth) {
 380         case CHANWIDTH_USE_HT:
 381                 if (center_segment1 ||
 382                     (center_segment0 != 0 &&
 383                      5000 + center_segment0 * 5 != data->center_freq1 &&
 384                      2407 + center_segment0 * 5 != data->center_freq1))
 385                         return -1;
 386                 break;
 387         case CHANWIDTH_80P80MHZ:
 388                 if (!(vht_caps & VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)) {
 389                         wpa_printf(MSG_ERROR,
 390                                    "80+80 channel width is not supported!");
 391                         return -1;
 392                 }
 393                 if (center_segment1 == center_segment0 + 4 ||
 394                     center_segment1 == center_segment0 - 4)
 395                         return -1;
 396                 data->center_freq2 = 5000 + center_segment1 * 5;
 397                 /* fall through */
 398         case CHANWIDTH_80MHZ:
 399                 data->bandwidth = 80;
 400                 if ((oper_chwidth == CHANWIDTH_80MHZ &&
 401                      center_segment1) ||
 402                     (oper_chwidth == CHANWIDTH_80P80MHZ &&
 403                      !center_segment1) ||
 404                     !sec_channel_offset)
 405                         return -1;
 406                 if (!center_segment0) {
 407                         if (channel <= 48)
 408                                 center_segment0 = 42;
 409                         else if (channel <= 64)
 410                                 center_segment0 = 58;
 411                         else if (channel <= 112)
 412                                 center_segment0 = 106;
 413                         else if (channel <= 128)
 414                                 center_segment0 = 122;
 415                         else if (channel <= 144)
 416                                 center_segment0 = 138;
 417                         else if (channel <= 161)
 418                                 center_segment0 = 155;
 419                         data->center_freq1 = 5000 + center_segment0 * 5;
 420                 } else {
 421                         /*
 422                          * Note: HT/VHT config and params are coupled. Check if
 423                          * HT40 channel band is in VHT80 Pri channel band
 424                          * configuration.
 425                          */
 426                         if (center_segment0 == channel + 6 ||
 427                             center_segment0 == channel + 2 ||
 428                             center_segment0 == channel - 2 ||
 429                             center_segment0 == channel - 6)
 430                                 data->center_freq1 = 5000 + center_segment0 * 5;
 431                         else
 432                                 return -1;
 433                 }
 434                 break;
 435         case CHANWIDTH_160MHZ:
 436                 data->bandwidth = 160;
 437                 if (!(vht_caps & (VHT_CAP_SUPP_CHAN_WIDTH_160MHZ |
 438                                   VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))) {
 439                         wpa_printf(MSG_ERROR,
 440                                    "160MHZ channel width is not supported!");
 441                         return -1;
 442                 }
 443                 if (center_segment1)
 444                         return -1;
 445                 if (!sec_channel_offset)
 446                         return -1;
 447                 /*
 448                  * Note: HT/VHT config and params are coupled. Check if
 449                  * HT40 channel band is in VHT160 channel band configuration.
 450                  */
 451                 if (center_segment0 == channel + 14 ||
 452                     center_segment0 == channel + 10 ||
 453                     center_segment0 == channel + 6 ||
 454                     center_segment0 == channel + 2 ||
 455                     center_segment0 == channel - 2 ||
 456                     center_segment0 == channel - 6 ||
 457                     center_segment0 == channel - 10 ||
 458                     center_segment0 == channel - 14)
 459                         data->center_freq1 = 5000 + center_segment0 * 5;
 460                 else
 461                         return -1;
 462                 break;
 463         }
 464
 465         return 0;
 466 }
 467
 468
 469 void set_disable_ht40(struct ieee80211_ht_capabilities *htcaps,
 470                       int disabled)
 471 {
 472         /* Masking these out disables HT40 */
 473         le16 msk = host_to_le16(HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET |
 474                                 HT_CAP_INFO_SHORT_GI40MHZ);
 475
 476         if (disabled)
 477                 htcaps->ht_capabilities_info &= ~msk;
 478         else
 479                 htcaps->ht_capabilities_info |= msk;
 480 }
 481
 482
 483 #ifdef CONFIG_IEEE80211AC
 484
 485 static int _ieee80211ac_cap_check(u32 hw, u32 conf, u32 cap,
 486                                   const char *name)
 487 {
 488         u32 req_cap = conf & cap;
 489
 490         /*
 491          * Make sure we support all requested capabilities.
 492          * NOTE: We assume that 'cap' represents a capability mask,
 493          * not a discrete value.
 494          */
 495         if ((hw & req_cap) != req_cap) {
 496                 wpa_printf(MSG_ERROR,
 497                            "Driver does not support configured VHT capability [%s]",
 498                            name);
 499                 return 0;
 500         }
 501         return 1;
 502 }
 503
 504
 505 static int ieee80211ac_cap_check_max(u32 hw, u32 conf, u32 mask,
 506                                      unsigned int shift,
 507                                      const char *name)
 508 {
 509         u32 hw_max = hw & mask;
 510         u32 conf_val = conf & mask;
 511
 512         if (conf_val > hw_max) {
 513                 wpa_printf(MSG_ERROR,
 514                            "Configured VHT capability [%s] exceeds max value supported by the driver (%d > %d)",
 515                            name, conf_val >> shift, hw_max >> shift);
 516                 return 0;
 517         }
 518         return 1;
 519 }
 520
 521
 522 int ieee80211ac_cap_check(u32 hw, u32 conf)
 523 {
 524 #define VHT_CAP_CHECK(cap) \
 525         do { \
 526                 if (!_ieee80211ac_cap_check(hw, conf, cap, #cap)) \
 527                         return 0; \
 528         } while (0)
 529
 530 #define VHT_CAP_CHECK_MAX(cap) \
 531         do { \
 532                 if (!ieee80211ac_cap_check_max(hw, conf, cap, cap ## _SHIFT, \
 533                                                #cap)) \
 534                         return 0; \
 535         } while (0)
 536
 537         VHT_CAP_CHECK_MAX(VHT_CAP_MAX_MPDU_LENGTH_MASK);
 538         VHT_CAP_CHECK_MAX(VHT_CAP_SUPP_CHAN_WIDTH_MASK);
 539         VHT_CAP_CHECK(VHT_CAP_RXLDPC);
 540         VHT_CAP_CHECK(VHT_CAP_SHORT_GI_80);
 541         VHT_CAP_CHECK(VHT_CAP_SHORT_GI_160);
 542         VHT_CAP_CHECK(VHT_CAP_TXSTBC);
 543         VHT_CAP_CHECK_MAX(VHT_CAP_RXSTBC_MASK);
 544         VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMER_CAPABLE);
 545         VHT_CAP_CHECK(VHT_CAP_SU_BEAMFORMEE_CAPABLE);
 546         VHT_CAP_CHECK_MAX(VHT_CAP_BEAMFORMEE_STS_MAX);
 547         VHT_CAP_CHECK_MAX(VHT_CAP_SOUNDING_DIMENSION_MAX);
 548         VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMER_CAPABLE);
 549         VHT_CAP_CHECK(VHT_CAP_MU_BEAMFORMEE_CAPABLE);
 550         VHT_CAP_CHECK(VHT_CAP_VHT_TXOP_PS);
 551         VHT_CAP_CHECK(VHT_CAP_HTC_VHT);
 552         VHT_CAP_CHECK_MAX(VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MAX);
 553         VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB);
 554         VHT_CAP_CHECK(VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB);
 555         VHT_CAP_CHECK(VHT_CAP_RX_ANTENNA_PATTERN);
 556         VHT_CAP_CHECK(VHT_CAP_TX_ANTENNA_PATTERN);
 557
 558 #undef VHT_CAP_CHECK
 559 #undef VHT_CAP_CHECK_MAX
 560
 561         return 1;
 562 }
 563
 564 #endif /* CONFIG_IEEE80211AC */
 565
 566
 567 u32 num_chan_to_bw(int num_chans)
 568 {
 569         switch (num_chans) {
 570         case 2:
 571         case 4:
 572         case 8:
 573                 return num_chans * 20;
 574         default:
 575                 return 20;
 576         }
 577 }
 578
 579
 580 /* check if BW is applicable for channel */
 581 int chan_bw_allowed(const struct hostapd_channel_data *chan, u32 bw,
 582                     int ht40_plus, int pri)
 583 {
 584         u32 bw_mask;
 585
 586         switch (bw) {
 587         case 20:
 588                 bw_mask = HOSTAPD_CHAN_WIDTH_20;
 589                 break;
 590         case 40:
 591                 /* HT 40 MHz support declared only for primary channel,
 592                  * just skip 40 MHz secondary checking */
 593                 if (pri && ht40_plus)
 594                         bw_mask = HOSTAPD_CHAN_WIDTH_40P;
 595                 else if (pri && !ht40_plus)
 596                         bw_mask = HOSTAPD_CHAN_WIDTH_40M;
 597                 else
 598                         bw_mask = 0;
 599                 break;
 600         case 80:
 601                 bw_mask = HOSTAPD_CHAN_WIDTH_80;
 602                 break;
 603         case 160:
 604                 bw_mask = HOSTAPD_CHAN_WIDTH_160;
 605                 break;
 606         default:
 607                 bw_mask = 0;
 608                 break;
 609         }
 610
 611         return (chan->allowed_bw & bw_mask) == bw_mask;
 612 }
 613
 614
 615 /* check if channel is allowed to be used as primary */
 616 int chan_pri_allowed(const struct hostapd_channel_data *chan)
 617 {
 618         return !(chan->flag & HOSTAPD_CHAN_DISABLED) &&
 619                 (chan->allowed_bw & HOSTAPD_CHAN_WIDTH_20);
 620 }