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 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 179                       const u8 *ht_capab, size_t ht_capab_len)
 180 {
 181         /* Disable HT caps for STAs associated to no-HT BSSes. */
 182         if (!ht_capab ||
 183             ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
 184             hapd->conf->disable_11n) {
 185                 sta->flags &= ~WLAN_STA_HT;
 186                 os_free(sta->ht_capabilities);
 187                 sta->ht_capabilities = NULL;
 188                 return WLAN_STATUS_SUCCESS;
 189         }
 190
 191         if (sta->ht_capabilities == NULL) {
 192                 sta->ht_capabilities =
 193                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 194                 if (sta->ht_capabilities == NULL)
 195                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 196         }
 197
 198         sta->flags |= WLAN_STA_HT;
 199         os_memcpy(sta->ht_capabilities, ht_capab,
 200                   sizeof(struct ieee80211_ht_capabilities));
 201
 202         return WLAN_STATUS_SUCCESS;
 203 }
 204
 205
 206 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
 207 {
 208         if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 209                 return;
 210
 211         wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
 212                    " in Association Request", MAC2STR(sta->addr));
 213
 214         if (sta->ht40_intolerant_set)
 215                 return;
 216
 217         sta->ht40_intolerant_set = 1;
 218         iface->num_sta_ht40_intolerant++;
 219         eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 220
 221         if (iface->conf->secondary_channel &&
 222             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 223                 iface->conf->secondary_channel = 0;
 224                 ieee802_11_set_beacons(iface);
 225         }
 226 }
 227
 228
 229 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
 230 {
 231         if (!sta->ht40_intolerant_set)
 232                 return;
 233
 234         sta->ht40_intolerant_set = 0;
 235         iface->num_sta_ht40_intolerant--;
 236
 237         if (iface->num_sta_ht40_intolerant == 0 &&
 238             (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
 239             (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 240                 unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 241                         iface->conf->obss_interval;
 242                 wpa_printf(MSG_DEBUG,
 243                            "HT: Start 20->40 MHz transition timer (%d seconds)",
 244                            delay_time);
 245                 eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 246                 eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 247                                        iface, NULL);
 248         }
 249 }
 250
 251
 252 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 253 {
 254         u16 ht_capab;
 255
 256         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 257         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 258                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 259         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 260                 if (!sta->no_ht_gf_set) {
 261                         sta->no_ht_gf_set = 1;
 262                         hapd->iface->num_sta_ht_no_gf++;
 263                 }
 264                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 265                            "of non-gf stations %d",
 266                            __func__, MAC2STR(sta->addr),
 267                            hapd->iface->num_sta_ht_no_gf);
 268         }
 269         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 270                 if (!sta->ht_20mhz_set) {
 271                         sta->ht_20mhz_set = 1;
 272                         hapd->iface->num_sta_ht_20mhz++;
 273                 }
 274                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 275                            "20MHz HT STAs %d",
 276                            __func__, MAC2STR(sta->addr),
 277                            hapd->iface->num_sta_ht_20mhz);
 278         }
 279
 280         if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
 281                 ht40_intolerant_add(hapd->iface, sta);
 282 }
 283
 284
 285 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 286 {
 287         if (!sta->no_ht_set) {
 288                 sta->no_ht_set = 1;
 289                 hapd->iface->num_sta_no_ht++;
 290         }
 291         if (hapd->iconf->ieee80211n) {
 292                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 293                            "non-HT stations %d",
 294                            __func__, MAC2STR(sta->addr),
 295                            hapd->iface->num_sta_no_ht);
 296         }
 297 }
 298
 299
 300 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 301 {
 302         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 303                 update_sta_ht(hapd, sta);
 304         else
 305                 update_sta_no_ht(hapd, sta);
 306
 307         if (hostapd_ht_operation_update(hapd->iface) > 0)
 308                 ieee802_11_set_beacons(hapd->iface);
 309 }
 310
 311
 312 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 313                           struct ieee80211_ht_capabilities *ht_cap,
 314                           struct ieee80211_ht_capabilities *neg_ht_cap)
 315 {
 316         u16 cap;
 317
 318         if (ht_cap == NULL)
 319                 return;
 320         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 321         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 322
 323         /*
 324          * Mask out HT features we don't support, but don't overwrite
 325          * non-symmetric features like STBC and SMPS. Just because
 326          * we're not in dynamic SMPS mode the STA might still be.
 327          */
 328         cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
 329                 HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
 330
 331         /*
 332          * STBC needs to be handled specially
 333          * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
 334          * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
 335          */
 336         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
 337                 cap &= ~HT_CAP_INFO_TX_STBC;
 338         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
 339                 cap &= ~HT_CAP_INFO_RX_STBC_MASK;
 340
 341         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 342 }
 343
 344
 345 void ap_ht2040_timeout(void *eloop_data, void *user_data)
 346 {
 347         struct hostapd_iface *iface = eloop_data;
 348
 349         wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
 350
 351         iface->conf->secondary_channel = iface->secondary_ch;
 352         ieee802_11_set_beacons(iface);
 353 }