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 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 "utils/includes.h"
  17
  18 #include "utils/common.h"
  19 #include "common/ieee802_11_defs.h"
  20 #include "drivers/driver.h"
  21 #include "hostapd.h"
  22 #include "ap_config.h"
  23 #include "sta_info.h"
  24 #include "beacon.h"
  25 #include "ieee802_11.h"
  26
  27
  28 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
  29 {
  30         struct ieee80211_ht_capabilities *cap;
  31         u8 *pos = eid;
  32
  33         if (!hapd->iconf->ieee80211n)
  34                 return eid;
  35
  36         *pos++ = WLAN_EID_HT_CAP;
  37         *pos++ = sizeof(*cap);
  38
  39         cap = (struct ieee80211_ht_capabilities *) pos;
  40         os_memset(cap, 0, sizeof(*cap));
  41         cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
  42         cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
  43         os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
  44                   16);
  45
  46         /* TODO: ht_extended_capabilities (now fully disabled) */
  47         /* TODO: tx_bf_capability_info (now fully disabled) */
  48         /* TODO: asel_capabilities (now fully disabled) */
  49
  50         pos += sizeof(*cap);
  51
  52         return pos;
  53 }
  54
  55
  56 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
  57 {
  58         struct ieee80211_ht_operation *oper;
  59         u8 *pos = eid;
  60
  61         if (!hapd->iconf->ieee80211n)
  62                 return eid;
  63
  64         *pos++ = WLAN_EID_HT_OPERATION;
  65         *pos++ = sizeof(*oper);
  66
  67         oper = (struct ieee80211_ht_operation *) pos;
  68         os_memset(oper, 0, sizeof(*oper));
  69
  70         oper->control_chan = hapd->iconf->channel;
  71         oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
  72         if (hapd->iconf->secondary_channel == 1)
  73                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
  74                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  75         if (hapd->iconf->secondary_channel == -1)
  76                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
  77                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  78
  79         pos += sizeof(*oper);
  80
  81         return pos;
  82 }
  83
  84
  85 /*
  86 op_mode
  87 Set to 0 (HT pure) under the followign conditions
  88         - all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
  89         - all STAs in the BSS are 20 MHz HT in 20 MHz BSS
  90 Set to 1 (HT non-member protection) if there may be non-HT STAs
  91         in both the primary and the secondary channel
  92 Set to 2 if only HT STAs are associated in BSS,
  93         however and at least one 20 MHz HT STA is associated
  94 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
  95         (currently non-GF HT station is considered as non-HT STA also)
  96 */
  97 int hostapd_ht_operation_update(struct hostapd_iface *iface)
  98 {
  99         u16 cur_op_mode, new_op_mode;
 100         int op_mode_changes = 0;
 101
 102         if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 103                 return 0;
 104
 105         wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 106                    __func__, iface->ht_op_mode);
 107
 108         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
 109             && iface->num_sta_ht_no_gf) {
 110                 iface->ht_op_mode |=
 111                         HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 112                 op_mode_changes++;
 113         } else if ((iface->ht_op_mode &
 114                     HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
 115                    iface->num_sta_ht_no_gf == 0) {
 116                 iface->ht_op_mode &=
 117                         ~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 118                 op_mode_changes++;
 119         }
 120
 121         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 122             (iface->num_sta_no_ht || iface->olbc_ht)) {
 123                 iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 124                 op_mode_changes++;
 125         } else if ((iface->ht_op_mode &
 126                     HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 127                    (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 128                 iface->ht_op_mode &=
 129                         ~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 130                 op_mode_changes++;
 131         }
 132
 133         /* Note: currently we switch to the MIXED op mode if HT non-greenfield
 134          * station is associated. Probably it's a theoretical case, since
 135          * it looks like all known HT STAs support greenfield.
 136          */
 137         new_op_mode = 0;
 138         if (iface->num_sta_no_ht ||
 139             (iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT))
 140                 new_op_mode = OP_MODE_MIXED;
 141         else if ((iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)
 142                  && iface->num_sta_ht_20mhz)
 143                 new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
 144         else if (iface->olbc_ht)
 145                 new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
 146         else
 147                 new_op_mode = OP_MODE_PURE;
 148
 149         cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 150         if (cur_op_mode != new_op_mode) {
 151                 iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 152                 iface->ht_op_mode |= new_op_mode;
 153                 op_mode_changes++;
 154         }
 155
 156         wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 157                    __func__, iface->ht_op_mode, op_mode_changes);
 158
 159         return op_mode_changes;
 160 }
 161
 162
 163 u16 copy_sta_ht_capab(struct sta_info *sta, const u8 *ht_capab,
 164                       size_t ht_capab_len)
 165 {
 166         if (!ht_capab ||
 167             ht_capab_len < sizeof(struct ieee80211_ht_capabilities)) {
 168                 sta->flags &= ~WLAN_STA_HT;
 169                 os_free(sta->ht_capabilities);
 170                 sta->ht_capabilities = NULL;
 171                 return WLAN_STATUS_SUCCESS;
 172         }
 173
 174         if (sta->ht_capabilities == NULL) {
 175                 sta->ht_capabilities =
 176                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 177                 if (sta->ht_capabilities == NULL)
 178                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 179         }
 180
 181         sta->flags |= WLAN_STA_HT;
 182         os_memcpy(sta->ht_capabilities, ht_capab,
 183                   sizeof(struct ieee80211_ht_capabilities));
 184
 185         return WLAN_STATUS_SUCCESS;
 186 }
 187
 188
 189 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 190 {
 191         u16 ht_capab;
 192
 193         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 194         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 195                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 196         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 197                 if (!sta->no_ht_gf_set) {
 198                         sta->no_ht_gf_set = 1;
 199                         hapd->iface->num_sta_ht_no_gf++;
 200                 }
 201                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 202                            "of non-gf stations %d",
 203                            __func__, MAC2STR(sta->addr),
 204                            hapd->iface->num_sta_ht_no_gf);
 205         }
 206         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 207                 if (!sta->ht_20mhz_set) {
 208                         sta->ht_20mhz_set = 1;
 209                         hapd->iface->num_sta_ht_20mhz++;
 210                 }
 211                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 212                            "20MHz HT STAs %d",
 213                            __func__, MAC2STR(sta->addr),
 214                            hapd->iface->num_sta_ht_20mhz);
 215         }
 216 }
 217
 218
 219 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 220 {
 221         if (!sta->no_ht_set) {
 222                 sta->no_ht_set = 1;
 223                 hapd->iface->num_sta_no_ht++;
 224         }
 225         if (hapd->iconf->ieee80211n) {
 226                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 227                            "non-HT stations %d",
 228                            __func__, MAC2STR(sta->addr),
 229                            hapd->iface->num_sta_no_ht);
 230         }
 231 }
 232
 233
 234 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 235 {
 236         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 237                 update_sta_ht(hapd, sta);
 238         else
 239                 update_sta_no_ht(hapd, sta);
 240
 241         if (hostapd_ht_operation_update(hapd->iface) > 0)
 242                 ieee802_11_set_beacons(hapd->iface);
 243 }
 244
 245
 246 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 247                           struct ieee80211_ht_capabilities *ht_cap,
 248                           struct ieee80211_ht_capabilities *neg_ht_cap)
 249 {
 250         u16 cap;
 251
 252         if (ht_cap == NULL)
 253                 return;
 254         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 255         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 256         cap &= hapd->iconf->ht_capab;
 257         cap |= (hapd->iconf->ht_capab & HT_CAP_INFO_SMPS_DISABLED);
 258
 259         /* FIXME: Rx STBC needs to be handled specially */
 260         cap |= (hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK);
 261         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 262 }