hostapd/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 program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Alternatively, this software may be distributed under the terms of BSD
  11  * license.
  12  *
  13  * See README and COPYING for more details.
  14  */
  15
  16 #include "includes.h"
  17
  18 #include "common.h"
  19 #include "drivers/driver.h"
  20 #include "hostapd.h"
  21 #include "config.h"
  22 #include "sta_info.h"
  23 #include "beacon.h"
  24 #include "ieee802_11.h"
  25
  26
  27 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
  28 {
  29         struct ieee80211_ht_capabilities *cap;
  30         u8 *pos = eid;
  31
  32         if (!hapd->iconf->ieee80211n)
  33                 return eid;
  34
  35         *pos++ = WLAN_EID_HT_CAP;
  36         *pos++ = sizeof(*cap);
  37
  38         cap = (struct ieee80211_ht_capabilities *) pos;
  39         os_memset(cap, 0, sizeof(*cap));
  40         cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
  41         cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
  42         os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
  43                   16);
  44
  45         /* TODO: ht_extended_capabilities (now fully disabled) */
  46         /* TODO: tx_bf_capability_info (now fully disabled) */
  47         /* TODO: asel_capabilities (now fully disabled) */
  48
  49         pos += sizeof(*cap);
  50
  51         return pos;
  52 }
  53
  54
  55 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
  56 {
  57         struct ieee80211_ht_operation *oper;
  58         u8 *pos = eid;
  59
  60         if (!hapd->iconf->ieee80211n)
  61                 return eid;
  62
  63         *pos++ = WLAN_EID_HT_OPERATION;
  64         *pos++ = sizeof(*oper);
  65
  66         oper = (struct ieee80211_ht_operation *) pos;
  67         os_memset(oper, 0, sizeof(*oper));
  68
  69         oper->control_chan = hapd->iconf->channel;
  70         oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
  71         if (hapd->iconf->secondary_channel == 1)
  72                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
  73                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  74         if (hapd->iconf->secondary_channel == -1)
  75                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
  76                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  77
  78         pos += sizeof(*oper);
  79
  80         return pos;
  81 }
  82
  83
  84 /*
  85 op_mode
  86 Set to 0 (HT pure) under the followign conditions
  87         - all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
  88         - all STAs in the BSS are 20 MHz HT in 20 MHz BSS
  89 Set to 1 (HT non-member protection) if there may be non-HT STAs
  90         in both the primary and the secondary channel
  91 Set to 2 if only HT STAs are associated in BSS,
  92         however and at least one 20 MHz HT STA is associated
  93 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
  94         (currently non-GF HT station is considered as non-HT STA also)
  95 */
  96 int hostapd_ht_operation_update(struct hostapd_iface *iface)
  97 {
  98         u16 cur_op_mode, new_op_mode;
  99         int op_mode_changes = 0;
 100
 101         if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 102                 return 0;
 103
 104         wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 105                    __func__, iface->ht_op_mode);
 106
 107         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
 108             && iface->num_sta_ht_no_gf) {
 109                 iface->ht_op_mode |=
 110                         HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 111                 op_mode_changes++;
 112         } else if ((iface->ht_op_mode &
 113                     HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
 114                    iface->num_sta_ht_no_gf == 0) {
 115                 iface->ht_op_mode &=
 116                         ~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 117                 op_mode_changes++;
 118         }
 119
 120         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 121             (iface->num_sta_no_ht || iface->olbc_ht)) {
 122                 iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 123                 op_mode_changes++;
 124         } else if ((iface->ht_op_mode &
 125                     HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 126                    (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 127                 iface->ht_op_mode &=
 128                         ~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 129                 op_mode_changes++;
 130         }
 131
 132         /* Note: currently we switch to the MIXED op mode if HT non-greenfield
 133          * station is associated. Probably it's a theoretical case, since
 134          * it looks like all known HT STAs support greenfield.
 135          */
 136         new_op_mode = 0;
 137         if (iface->num_sta_no_ht ||
 138             (iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT))
 139                 new_op_mode = OP_MODE_MIXED;
 140         else if ((iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)
 141                  && iface->num_sta_ht_20mhz)
 142                 new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
 143         else if (iface->olbc_ht)
 144                 new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
 145         else
 146                 new_op_mode = OP_MODE_PURE;
 147
 148         cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 149         if (cur_op_mode != new_op_mode) {
 150                 iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 151                 iface->ht_op_mode |= new_op_mode;
 152                 op_mode_changes++;
 153         }
 154
 155         wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 156                    __func__, iface->ht_op_mode, op_mode_changes);
 157
 158         return op_mode_changes;
 159 }
 160
 161
 162 u16 copy_sta_ht_capab(struct sta_info *sta, const u8 *ht_capab,
 163                       size_t ht_capab_len)
 164 {
 165         if (!ht_capab ||
 166             ht_capab_len < sizeof(struct ieee80211_ht_capabilities)) {
 167                 sta->flags &= ~WLAN_STA_HT;
 168                 os_free(sta->ht_capabilities);
 169                 sta->ht_capabilities = NULL;
 170                 return WLAN_STATUS_SUCCESS;
 171         }
 172
 173         if (sta->ht_capabilities == NULL) {
 174                 sta->ht_capabilities =
 175                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 176                 if (sta->ht_capabilities == NULL)
 177                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 178         }
 179
 180         sta->flags |= WLAN_STA_HT;
 181         os_memcpy(sta->ht_capabilities, ht_capab,
 182                   sizeof(struct ieee80211_ht_capabilities));
 183
 184         return WLAN_STATUS_SUCCESS;
 185 }
 186
 187
 188 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 189 {
 190         u16 ht_capab;
 191
 192         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 193         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 194                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 195         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 196                 if (!sta->no_ht_gf_set) {
 197                         sta->no_ht_gf_set = 1;
 198                         hapd->iface->num_sta_ht_no_gf++;
 199                 }
 200                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 201                            "of non-gf stations %d",
 202                            __func__, MAC2STR(sta->addr),
 203                            hapd->iface->num_sta_ht_no_gf);
 204         }
 205         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 206                 if (!sta->ht_20mhz_set) {
 207                         sta->ht_20mhz_set = 1;
 208                         hapd->iface->num_sta_ht_20mhz++;
 209                 }
 210                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 211                            "20MHz HT STAs %d",
 212                            __func__, MAC2STR(sta->addr),
 213                            hapd->iface->num_sta_ht_20mhz);
 214         }
 215 }
 216
 217
 218 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 219 {
 220         if (!sta->no_ht_set) {
 221                 sta->no_ht_set = 1;
 222                 hapd->iface->num_sta_no_ht++;
 223         }
 224         if (hapd->iconf->ieee80211n) {
 225                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 226                            "non-HT stations %d",
 227                            __func__, MAC2STR(sta->addr),
 228                            hapd->iface->num_sta_no_ht);
 229         }
 230 }
 231
 232
 233 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 234 {
 235         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 236                 update_sta_ht(hapd, sta);
 237         else
 238                 update_sta_no_ht(hapd, sta);
 239
 240         if (hostapd_ht_operation_update(hapd->iface) > 0)
 241                 ieee802_11_set_beacons(hapd->iface);
 242 }
 243
 244
 245 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 246                           struct ieee80211_ht_capabilities *ht_cap,
 247                           struct ieee80211_ht_capabilities *neg_ht_cap)
 248 {
 249         u16 cap;
 250
 251         if (ht_cap == NULL)
 252                 return;
 253         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 254         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 255         cap &= hapd->iconf->ht_capab;
 256         cap |= (hapd->iconf->ht_capab & HT_CAP_INFO_SMPS_DISABLED);
 257
 258         /* FIXME: Rx STBC needs to be handled specially */
 259         cap |= (hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK);
 260         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 261 }