contrib/wpa/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 /*
 112 op_mode
 113 Set to 0 (HT pure) under the followign conditions
 114         - all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
 115         - all STAs in the BSS are 20 MHz HT in 20 MHz BSS
 116 Set to 1 (HT non-member protection) if there may be non-HT STAs
 117         in both the primary and the secondary channel
 118 Set to 2 if only HT STAs are associated in BSS,
 119         however and at least one 20 MHz HT STA is associated
 120 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
 121 */
 122 int hostapd_ht_operation_update(struct hostapd_iface *iface)
 123 {
 124         u16 cur_op_mode, new_op_mode;
 125         int op_mode_changes = 0;
 126
 127         if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 128                 return 0;
 129
 130         wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 131                    __func__, iface->ht_op_mode);
 132
 133         if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
 134             && iface->num_sta_ht_no_gf) {
 135                 iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 136                 op_mode_changes++;
 137         } else if ((iface->ht_op_mode &
 138                     HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
 139                    iface->num_sta_ht_no_gf == 0) {
 140                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 141                 op_mode_changes++;
 142         }
 143
 144         if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 145             (iface->num_sta_no_ht || iface->olbc_ht)) {
 146                 iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 147                 op_mode_changes++;
 148         } else if ((iface->ht_op_mode &
 149                     HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 150                    (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 151                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 152                 op_mode_changes++;
 153         }
 154
 155         if (iface->num_sta_no_ht)
 156                 new_op_mode = HT_PROT_NON_HT_MIXED;
 157         else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
 158                 new_op_mode = HT_PROT_20MHZ_PROTECTION;
 159         else if (iface->olbc_ht)
 160                 new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
 161         else
 162                 new_op_mode = HT_PROT_NO_PROTECTION;
 163
 164         cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
 165         if (cur_op_mode != new_op_mode) {
 166                 iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
 167                 iface->ht_op_mode |= new_op_mode;
 168                 op_mode_changes++;
 169         }
 170
 171         wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 172                    __func__, iface->ht_op_mode, op_mode_changes);
 173
 174         return op_mode_changes;
 175 }
 176
 177
 178 static int is_40_allowed(struct hostapd_iface *iface, int channel)
 179 {
 180         int pri_freq, sec_freq;
 181         int affected_start, affected_end;
 182         int pri = 2407 + 5 * channel;
 183
 184         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 185                 return 1;
 186
 187         pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
 188
 189         if (iface->conf->secondary_channel > 0)
 190                 sec_freq = pri_freq + 20;
 191         else
 192                 sec_freq = pri_freq - 20;
 193
 194         affected_start = (pri_freq + sec_freq) / 2 - 25;
 195         affected_end = (pri_freq + sec_freq) / 2 + 25;
 196         if ((pri < affected_start || pri > affected_end))
 197                 return 1; /* not within affected channel range */
 198
 199         wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
 200                    affected_start, affected_end);
 201         wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
 202         return 0;
 203 }
 204
 205
 206 void hostapd_2040_coex_action(struct hostapd_data *hapd,
 207                               const struct ieee80211_mgmt *mgmt, size_t len)
 208 {
 209         struct hostapd_iface *iface = hapd->iface;
 210         struct ieee80211_2040_bss_coex_ie *bc_ie;
 211         struct ieee80211_2040_intol_chan_report *ic_report;
 212         int is_ht_allowed = 1;
 213         int i;
 214         const u8 *start = (const u8 *) mgmt;
 215         const u8 *data = start + IEEE80211_HDRLEN + 2;
 216
 217         hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 218                        HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
 219                        mgmt->u.action.u.public_action.action);
 220
 221         if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
 222                 return;
 223
 224         if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
 225                 return;
 226
 227         bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
 228         if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
 229             bc_ie->length < 1) {
 230                 wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
 231                            bc_ie->element_id, bc_ie->length);
 232                 return;
 233         }
 234         if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
 235                 return;
 236         data += 2 + bc_ie->length;
 237
 238         wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
 239                    bc_ie->coex_param);
 240         if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
 241                 hostapd_logger(hapd, mgmt->sa,
 242                                HOSTAPD_MODULE_IEEE80211,
 243                                HOSTAPD_LEVEL_DEBUG,
 244                                "20 MHz BSS width request bit is set in BSS coexistence information field");
 245                 is_ht_allowed = 0;
 246         }
 247
 248         if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
 249                 hostapd_logger(hapd, mgmt->sa,
 250                                HOSTAPD_MODULE_IEEE80211,
 251                                HOSTAPD_LEVEL_DEBUG,
 252                                "40 MHz intolerant bit is set in BSS coexistence information field");
 253                 is_ht_allowed = 0;
 254         }
 255
 256         if (start + len - data >= 3 &&
 257             data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
 258                 u8 ielen = data[1];
 259
 260                 if (ielen > start + len - data - 2)
 261                         return;
 262                 ic_report = (struct ieee80211_2040_intol_chan_report *) data;
 263                 wpa_printf(MSG_DEBUG,
 264                            "20/40 BSS Intolerant Channel Report: Operating Class %u",
 265                            ic_report->op_class);
 266
 267                 /* Go through the channel report to find any BSS there in the
 268                  * affected channel range */
 269                 for (i = 0; i < ielen - 1; i++) {
 270                         u8 chan = ic_report->variable[i];
 271
 272                         if (is_40_allowed(iface, chan))
 273                                 continue;
 274                         hostapd_logger(hapd, mgmt->sa,
 275                                        HOSTAPD_MODULE_IEEE80211,
 276                                        HOSTAPD_LEVEL_DEBUG,
 277                                        "20_40_INTOLERANT channel %d reported",
 278                                        chan);
 279                         is_ht_allowed = 0;
 280                 }
 281         }
 282         wpa_printf(MSG_DEBUG, "is_ht_allowed=%d num_sta_ht40_intolerant=%d",
 283                    is_ht_allowed, iface->num_sta_ht40_intolerant);
 284
 285         if (!is_ht_allowed &&
 286             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 287                 if (iface->conf->secondary_channel) {
 288                         hostapd_logger(hapd, mgmt->sa,
 289                                        HOSTAPD_MODULE_IEEE80211,
 290                                        HOSTAPD_LEVEL_INFO,
 291                                        "Switching to 20 MHz operation");
 292                         iface->conf->secondary_channel = 0;
 293                         ieee802_11_set_beacons(iface);
 294                 }
 295                 if (!iface->num_sta_ht40_intolerant &&
 296                     iface->conf->obss_interval) {
 297                         unsigned int delay_time;
 298                         delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 299                                 iface->conf->obss_interval;
 300                         eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
 301                                              NULL);
 302                         eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 303                                                hapd->iface, NULL);
 304                         wpa_printf(MSG_DEBUG,
 305                                    "Reschedule HT 20/40 timeout to occur in %u seconds",
 306                                    delay_time);
 307                 }
 308         }
 309 }
 310
 311
 312 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 313                       const u8 *ht_capab, size_t ht_capab_len)
 314 {
 315         /* Disable HT caps for STAs associated to no-HT BSSes. */
 316         if (!ht_capab ||
 317             ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
 318             hapd->conf->disable_11n) {
 319                 sta->flags &= ~WLAN_STA_HT;
 320                 os_free(sta->ht_capabilities);
 321                 sta->ht_capabilities = NULL;
 322                 return WLAN_STATUS_SUCCESS;
 323         }
 324
 325         if (sta->ht_capabilities == NULL) {
 326                 sta->ht_capabilities =
 327                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 328                 if (sta->ht_capabilities == NULL)
 329                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 330         }
 331
 332         sta->flags |= WLAN_STA_HT;
 333         os_memcpy(sta->ht_capabilities, ht_capab,
 334                   sizeof(struct ieee80211_ht_capabilities));
 335
 336         return WLAN_STATUS_SUCCESS;
 337 }
 338
 339
 340 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
 341 {
 342         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 343                 return;
 344
 345         wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
 346                    " in Association Request", MAC2STR(sta->addr));
 347
 348         if (sta->ht40_intolerant_set)
 349                 return;
 350
 351         sta->ht40_intolerant_set = 1;
 352         iface->num_sta_ht40_intolerant++;
 353         eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 354
 355         if (iface->conf->secondary_channel &&
 356             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 357                 iface->conf->secondary_channel = 0;
 358                 ieee802_11_set_beacons(iface);
 359         }
 360 }
 361
 362
 363 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
 364 {
 365         if (!sta->ht40_intolerant_set)
 366                 return;
 367
 368         sta->ht40_intolerant_set = 0;
 369         iface->num_sta_ht40_intolerant--;
 370
 371         if (iface->num_sta_ht40_intolerant == 0 &&
 372             (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
 373             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 374                 unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 375                         iface->conf->obss_interval;
 376                 wpa_printf(MSG_DEBUG,
 377                            "HT: Start 20->40 MHz transition timer (%d seconds)",
 378                            delay_time);
 379                 eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 380                 eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 381                                        iface, NULL);
 382         }
 383 }
 384
 385
 386 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 387 {
 388         u16 ht_capab;
 389
 390         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 391         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 392                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 393         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 394                 if (!sta->no_ht_gf_set) {
 395                         sta->no_ht_gf_set = 1;
 396                         hapd->iface->num_sta_ht_no_gf++;
 397                 }
 398                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 399                            "of non-gf stations %d",
 400                            __func__, MAC2STR(sta->addr),
 401                            hapd->iface->num_sta_ht_no_gf);
 402         }
 403         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 404                 if (!sta->ht_20mhz_set) {
 405                         sta->ht_20mhz_set = 1;
 406                         hapd->iface->num_sta_ht_20mhz++;
 407                 }
 408                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 409                            "20MHz HT STAs %d",
 410                            __func__, MAC2STR(sta->addr),
 411                            hapd->iface->num_sta_ht_20mhz);
 412         }
 413
 414         if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
 415                 ht40_intolerant_add(hapd->iface, sta);
 416 }
 417
 418
 419 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 420 {
 421         if (!sta->no_ht_set) {
 422                 sta->no_ht_set = 1;
 423                 hapd->iface->num_sta_no_ht++;
 424         }
 425         if (hapd->iconf->ieee80211n) {
 426                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 427                            "non-HT stations %d",
 428                            __func__, MAC2STR(sta->addr),
 429                            hapd->iface->num_sta_no_ht);
 430         }
 431 }
 432
 433
 434 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 435 {
 436         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 437                 update_sta_ht(hapd, sta);
 438         else
 439                 update_sta_no_ht(hapd, sta);
 440
 441         if (hostapd_ht_operation_update(hapd->iface) > 0)
 442                 ieee802_11_set_beacons(hapd->iface);
 443 }
 444
 445
 446 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 447                           struct ieee80211_ht_capabilities *ht_cap,
 448                           struct ieee80211_ht_capabilities *neg_ht_cap)
 449 {
 450         u16 cap;
 451
 452         if (ht_cap == NULL)
 453                 return;
 454         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 455         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 456
 457         /*
 458          * Mask out HT features we don't support, but don't overwrite
 459          * non-symmetric features like STBC and SMPS. Just because
 460          * we're not in dynamic SMPS mode the STA might still be.
 461          */
 462         cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
 463                 HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
 464
 465         /*
 466          * STBC needs to be handled specially
 467          * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
 468          * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
 469          */
 470         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
 471                 cap &= ~HT_CAP_INFO_TX_STBC;
 472         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
 473                 cap &= ~HT_CAP_INFO_RX_STBC_MASK;
 474
 475         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 476 }
 477
 478
 479 void ap_ht2040_timeout(void *eloop_data, void *user_data)
 480 {
 481         struct hostapd_iface *iface = eloop_data;
 482
 483         wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
 484
 485         iface->conf->secondary_channel = iface->secondary_ch;
 486         ieee802_11_set_beacons(iface);
 487 }