libeap/src/ap/ieee802_11_ht.c

   1 /*
   2  * hostapd / IEEE 802.11n HT
   3  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
   4  * Copyright (c) 2007-2008, Intel Corporation
   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 "utils/eloop.h"
  14 #include "common/ieee802_11_defs.h"
  15 #include "hostapd.h"
  16 #include "ap_config.h"
  17 #include "sta_info.h"
  18 #include "beacon.h"
  19 #include "ieee802_11.h"
  20 #include "hw_features.h"
  21 #include "ap_drv_ops.h"
  22
  23
  24 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
  25 {
  26         struct ieee80211_ht_capabilities *cap;
  27         u8 *pos = eid;
  28
  29         if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
  30             hapd->conf->disable_11n)
  31                 return eid;
  32
  33         *pos++ = WLAN_EID_HT_CAP;
  34         *pos++ = sizeof(*cap);
  35
  36         cap = (struct ieee80211_ht_capabilities *) pos;
  37         os_memset(cap, 0, sizeof(*cap));
  38         cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
  39         cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
  40         os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
  41                   16);
  42
  43         /* TODO: ht_extended_capabilities (now fully disabled) */
  44         /* TODO: tx_bf_capability_info (now fully disabled) */
  45         /* TODO: asel_capabilities (now fully disabled) */
  46
  47         pos += sizeof(*cap);
  48
  49         if (hapd->iconf->obss_interval) {
  50                 struct ieee80211_obss_scan_parameters *scan_params;
  51
  52                 *pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
  53                 *pos++ = sizeof(*scan_params);
  54
  55                 scan_params = (struct ieee80211_obss_scan_parameters *) pos;
  56                 os_memset(scan_params, 0, sizeof(*scan_params));
  57                 scan_params->width_trigger_scan_interval =
  58                         host_to_le16(hapd->iconf->obss_interval);
  59
  60                 /* Fill in default values for remaining parameters
  61                  * (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
  62                 scan_params->scan_passive_dwell =
  63                         host_to_le16(20);
  64                 scan_params->scan_active_dwell =
  65                         host_to_le16(10);
  66                 scan_params->scan_passive_total_per_channel =
  67                         host_to_le16(200);
  68                 scan_params->scan_active_total_per_channel =
  69                         host_to_le16(20);
  70                 scan_params->channel_transition_delay_factor =
  71                         host_to_le16(5);
  72                 scan_params->scan_activity_threshold =
  73                         host_to_le16(25);
  74
  75                 pos += sizeof(*scan_params);
  76         }
  77
  78         return pos;
  79 }
  80
  81
  82 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
  83 {
  84         struct ieee80211_ht_operation *oper;
  85         u8 *pos = eid;
  86
  87         if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
  88                 return eid;
  89
  90         *pos++ = WLAN_EID_HT_OPERATION;
  91         *pos++ = sizeof(*oper);
  92
  93         oper = (struct ieee80211_ht_operation *) pos;
  94         os_memset(oper, 0, sizeof(*oper));
  95
  96         oper->primary_chan = hapd->iconf->channel;
  97         oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
  98         if (hapd->iconf->secondary_channel == 1)
  99                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
 100                         HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
 101         if (hapd->iconf->secondary_channel == -1)
 102                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
 103                         HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
 104
 105         pos += sizeof(*oper);
 106
 107         return pos;
 108 }
 109
 110
 111 u8 * hostapd_eid_secondary_channel(struct hostapd_data *hapd, u8 *eid)
 112 {
 113         u8 sec_ch;
 114
 115         if (!hapd->cs_freq_params.channel ||
 116             !hapd->cs_freq_params.sec_channel_offset)
 117                 return eid;
 118
 119         if (hapd->cs_freq_params.sec_channel_offset == -1)
 120                 sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW;
 121         else if (hapd->cs_freq_params.sec_channel_offset == 1)
 122                 sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE;
 123         else
 124                 return eid;
 125
 126         *eid++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
 127         *eid++ = 1;
 128         *eid++ = sec_ch;
 129
 130         return eid;
 131 }
 132
 133
 134 /*
 135 op_mode
 136 Set to 0 (HT pure) under the followign conditions
 137         - all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
 138         - all STAs in the BSS are 20 MHz HT in 20 MHz BSS
 139 Set to 1 (HT non-member protection) if there may be non-HT STAs
 140         in both the primary and the secondary channel
 141 Set to 2 if only HT STAs are associated in BSS,
 142         however and at least one 20 MHz HT STA is associated
 143 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
 144 */
 145 int hostapd_ht_operation_update(struct hostapd_iface *iface)
 146 {
 147         u16 cur_op_mode, new_op_mode;
 148         int op_mode_changes = 0;
 149
 150         if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 151                 return 0;
 152
 153         wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 154                    __func__, iface->ht_op_mode);
 155
 156         if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
 157             && iface->num_sta_ht_no_gf) {
 158                 iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 159                 op_mode_changes++;
 160         } else if ((iface->ht_op_mode &
 161                     HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
 162                    iface->num_sta_ht_no_gf == 0) {
 163                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 164                 op_mode_changes++;
 165         }
 166
 167         if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 168             (iface->num_sta_no_ht || iface->olbc_ht)) {
 169                 iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 170                 op_mode_changes++;
 171         } else if ((iface->ht_op_mode &
 172                     HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 173                    (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 174                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 175                 op_mode_changes++;
 176         }
 177
 178         if (iface->num_sta_no_ht)
 179                 new_op_mode = HT_PROT_NON_HT_MIXED;
 180         else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
 181                 new_op_mode = HT_PROT_20MHZ_PROTECTION;
 182         else if (iface->olbc_ht)
 183                 new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
 184         else
 185                 new_op_mode = HT_PROT_NO_PROTECTION;
 186
 187         cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
 188         if (cur_op_mode != new_op_mode) {
 189                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
 190                 iface->ht_op_mode |= new_op_mode;
 191                 op_mode_changes++;
 192         }
 193
 194         wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 195                    __func__, iface->ht_op_mode, op_mode_changes);
 196
 197         return op_mode_changes;
 198 }
 199
 200
 201 static int is_40_allowed(struct hostapd_iface *iface, int channel)
 202 {
 203         int pri_freq, sec_freq;
 204         int affected_start, affected_end;
 205         int pri = 2407 + 5 * channel;
 206
 207         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 208                 return 1;
 209
 210         pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
 211
 212         if (iface->conf->secondary_channel > 0)
 213                 sec_freq = pri_freq + 20;
 214         else
 215                 sec_freq = pri_freq - 20;
 216
 217         affected_start = (pri_freq + sec_freq) / 2 - 25;
 218         affected_end = (pri_freq + sec_freq) / 2 + 25;
 219         if ((pri < affected_start || pri > affected_end))
 220                 return 1; /* not within affected channel range */
 221
 222         wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
 223                    affected_start, affected_end);
 224         wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
 225         return 0;
 226 }
 227
 228
 229 void hostapd_2040_coex_action(struct hostapd_data *hapd,
 230                               const struct ieee80211_mgmt *mgmt, size_t len)
 231 {
 232         struct hostapd_iface *iface = hapd->iface;
 233         struct ieee80211_2040_bss_coex_ie *bc_ie;
 234         struct ieee80211_2040_intol_chan_report *ic_report;
 235         int is_ht40_allowed = 1;
 236         int i;
 237         const u8 *start = (const u8 *) mgmt;
 238         const u8 *data = start + IEEE80211_HDRLEN + 2;
 239
 240         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 241                        HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
 242                        mgmt->u.action.u.public_action.action);
 243
 244         if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
 245                 return;
 246
 247         if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
 248                 return;
 249
 250         bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
 251         if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
 252             bc_ie->length < 1) {
 253                 wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
 254                            bc_ie->element_id, bc_ie->length);
 255                 return;
 256         }
 257         if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
 258                 return;
 259         data += 2 + bc_ie->length;
 260
 261         wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
 262                    bc_ie->coex_param);
 263         if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
 264                 hostapd_logger(hapd, mgmt->sa,
 265                                HOSTAPD_MODULE_IEEE80211,
 266                                HOSTAPD_LEVEL_DEBUG,
 267                                "20 MHz BSS width request bit is set in BSS coexistence information field");
 268                 is_ht40_allowed = 0;
 269         }
 270
 271         if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
 272                 hostapd_logger(hapd, mgmt->sa,
 273                                HOSTAPD_MODULE_IEEE80211,
 274                                HOSTAPD_LEVEL_DEBUG,
 275                                "40 MHz intolerant bit is set in BSS coexistence information field");
 276                 is_ht40_allowed = 0;
 277         }
 278
 279         if (start + len - data >= 3 &&
 280             data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
 281                 u8 ielen = data[1];
 282
 283                 if (ielen > start + len - data - 2)
 284                         return;
 285                 ic_report = (struct ieee80211_2040_intol_chan_report *) data;
 286                 wpa_printf(MSG_DEBUG,
 287                            "20/40 BSS Intolerant Channel Report: Operating Class %u",
 288                            ic_report->op_class);
 289
 290                 /* Go through the channel report to find any BSS there in the
 291                  * affected channel range */
 292                 for (i = 0; i < ielen - 1; i++) {
 293                         u8 chan = ic_report->variable[i];
 294
 295                         if (is_40_allowed(iface, chan))
 296                                 continue;
 297                         hostapd_logger(hapd, mgmt->sa,
 298                                        HOSTAPD_MODULE_IEEE80211,
 299                                        HOSTAPD_LEVEL_DEBUG,
 300                                        "20_40_INTOLERANT channel %d reported",
 301                                        chan);
 302                         is_ht40_allowed = 0;
 303                 }
 304         }
 305         wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
 306                    is_ht40_allowed, iface->num_sta_ht40_intolerant);
 307
 308         if (!is_ht40_allowed &&
 309             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 310                 if (iface->conf->secondary_channel) {
 311                         hostapd_logger(hapd, mgmt->sa,
 312                                        HOSTAPD_MODULE_IEEE80211,
 313                                        HOSTAPD_LEVEL_INFO,
 314                                        "Switching to 20 MHz operation");
 315                         iface->conf->secondary_channel = 0;
 316                         ieee802_11_set_beacons(iface);
 317                 }
 318                 if (!iface->num_sta_ht40_intolerant &&
 319                     iface->conf->obss_interval) {
 320                         unsigned int delay_time;
 321                         delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 322                                 iface->conf->obss_interval;
 323                         eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
 324                                              NULL);
 325                         eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 326                                                hapd->iface, NULL);
 327                         wpa_printf(MSG_DEBUG,
 328                                    "Reschedule HT 20/40 timeout to occur in %u seconds",
 329                                    delay_time);
 330                 }
 331         }
 332 }
 333
 334
 335 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 336                       const u8 *ht_capab)
 337 {
 338         /*
 339          * Disable HT caps for STAs associated to no-HT BSSes, or for stations
 340          * that did not specify a valid WMM IE in the (Re)Association Request
 341          * frame.
 342          */
 343         if (!ht_capab ||
 344             !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
 345                 sta->flags &= ~WLAN_STA_HT;
 346                 os_free(sta->ht_capabilities);
 347                 sta->ht_capabilities = NULL;
 348                 return WLAN_STATUS_SUCCESS;
 349         }
 350
 351         if (sta->ht_capabilities == NULL) {
 352                 sta->ht_capabilities =
 353                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 354                 if (sta->ht_capabilities == NULL)
 355                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 356         }
 357
 358         sta->flags |= WLAN_STA_HT;
 359         os_memcpy(sta->ht_capabilities, ht_capab,
 360                   sizeof(struct ieee80211_ht_capabilities));
 361
 362         return WLAN_STATUS_SUCCESS;
 363 }
 364
 365
 366 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
 367 {
 368         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 369                 return;
 370
 371         wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
 372                    " in Association Request", MAC2STR(sta->addr));
 373
 374         if (sta->ht40_intolerant_set)
 375                 return;
 376
 377         sta->ht40_intolerant_set = 1;
 378         iface->num_sta_ht40_intolerant++;
 379         eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 380
 381         if (iface->conf->secondary_channel &&
 382             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 383                 iface->conf->secondary_channel = 0;
 384                 ieee802_11_set_beacons(iface);
 385         }
 386 }
 387
 388
 389 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
 390 {
 391         if (!sta->ht40_intolerant_set)
 392                 return;
 393
 394         sta->ht40_intolerant_set = 0;
 395         iface->num_sta_ht40_intolerant--;
 396
 397         if (iface->num_sta_ht40_intolerant == 0 &&
 398             (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
 399             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 400                 unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 401                         iface->conf->obss_interval;
 402                 wpa_printf(MSG_DEBUG,
 403                            "HT: Start 20->40 MHz transition timer (%d seconds)",
 404                            delay_time);
 405                 eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 406                 eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 407                                        iface, NULL);
 408         }
 409 }
 410
 411
 412 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 413 {
 414         u16 ht_capab;
 415
 416         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 417         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 418                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 419         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 420                 if (!sta->no_ht_gf_set) {
 421                         sta->no_ht_gf_set = 1;
 422                         hapd->iface->num_sta_ht_no_gf++;
 423                 }
 424                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 425                            "of non-gf stations %d",
 426                            __func__, MAC2STR(sta->addr),
 427                            hapd->iface->num_sta_ht_no_gf);
 428         }
 429         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 430                 if (!sta->ht_20mhz_set) {
 431                         sta->ht_20mhz_set = 1;
 432                         hapd->iface->num_sta_ht_20mhz++;
 433                 }
 434                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 435                            "20MHz HT STAs %d",
 436                            __func__, MAC2STR(sta->addr),
 437                            hapd->iface->num_sta_ht_20mhz);
 438         }
 439
 440         if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
 441                 ht40_intolerant_add(hapd->iface, sta);
 442 }
 443
 444
 445 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 446 {
 447         if (!sta->no_ht_set) {
 448                 sta->no_ht_set = 1;
 449                 hapd->iface->num_sta_no_ht++;
 450         }
 451         if (hapd->iconf->ieee80211n) {
 452                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 453                            "non-HT stations %d",
 454                            __func__, MAC2STR(sta->addr),
 455                            hapd->iface->num_sta_no_ht);
 456         }
 457 }
 458
 459
 460 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 461 {
 462         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 463                 update_sta_ht(hapd, sta);
 464         else
 465                 update_sta_no_ht(hapd, sta);
 466
 467         if (hostapd_ht_operation_update(hapd->iface) > 0)
 468                 ieee802_11_set_beacons(hapd->iface);
 469 }
 470
 471
 472 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 473                           struct ieee80211_ht_capabilities *ht_cap,
 474                           struct ieee80211_ht_capabilities *neg_ht_cap)
 475 {
 476         u16 cap;
 477
 478         if (ht_cap == NULL)
 479                 return;
 480         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 481         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 482
 483         /*
 484          * Mask out HT features we don't support, but don't overwrite
 485          * non-symmetric features like STBC and SMPS. Just because
 486          * we're not in dynamic SMPS mode the STA might still be.
 487          */
 488         cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
 489                 HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
 490
 491         /*
 492          * STBC needs to be handled specially
 493          * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
 494          * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
 495          */
 496         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
 497                 cap &= ~HT_CAP_INFO_TX_STBC;
 498         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
 499                 cap &= ~HT_CAP_INFO_RX_STBC_MASK;
 500
 501         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 502 }
 503
 504
 505 void ap_ht2040_timeout(void *eloop_data, void *user_data)
 506 {
 507         struct hostapd_iface *iface = eloop_data;
 508
 509         wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
 510
 511         iface->conf->secondary_channel = iface->secondary_ch;
 512         ieee802_11_set_beacons(iface);
 513 }