contrib/hostapd/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 "common/ieee802_11_defs.h"
  14 #include "hostapd.h"
  15 #include "ap_config.h"
  16 #include "sta_info.h"
  17 #include "beacon.h"
  18 #include "ieee802_11.h"
  19
  20
  21 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
  22 {
  23         struct ieee80211_ht_capabilities *cap;
  24         u8 *pos = eid;
  25
  26         if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
  27             hapd->conf->disable_11n)
  28                 return eid;
  29
  30         *pos++ = WLAN_EID_HT_CAP;
  31         *pos++ = sizeof(*cap);
  32
  33         cap = (struct ieee80211_ht_capabilities *) pos;
  34         os_memset(cap, 0, sizeof(*cap));
  35         cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
  36         cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
  37         os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
  38                   16);
  39
  40         /* TODO: ht_extended_capabilities (now fully disabled) */
  41         /* TODO: tx_bf_capability_info (now fully disabled) */
  42         /* TODO: asel_capabilities (now fully disabled) */
  43
  44         pos += sizeof(*cap);
  45
  46         if (hapd->iconf->obss_interval) {
  47                 struct ieee80211_obss_scan_parameters *scan_params;
  48
  49                 *pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
  50                 *pos++ = sizeof(*scan_params);
  51
  52                 scan_params = (struct ieee80211_obss_scan_parameters *) pos;
  53                 os_memset(scan_params, 0, sizeof(*scan_params));
  54                 scan_params->width_trigger_scan_interval =
  55                         host_to_le16(hapd->iconf->obss_interval);
  56
  57                 /* TODO: Fill in more parameters (supplicant ignores them) */
  58
  59                 pos += sizeof(*scan_params);
  60         }
  61
  62         return pos;
  63 }
  64
  65
  66 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
  67 {
  68         struct ieee80211_ht_operation *oper;
  69         u8 *pos = eid;
  70
  71         if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
  72                 return eid;
  73
  74         *pos++ = WLAN_EID_HT_OPERATION;
  75         *pos++ = sizeof(*oper);
  76
  77         oper = (struct ieee80211_ht_operation *) pos;
  78         os_memset(oper, 0, sizeof(*oper));
  79
  80         oper->control_chan = hapd->iconf->channel;
  81         oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
  82         if (hapd->iconf->secondary_channel == 1)
  83                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
  84                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  85         if (hapd->iconf->secondary_channel == -1)
  86                 oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
  87                         HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH;
  88
  89         pos += sizeof(*oper);
  90
  91         return pos;
  92 }
  93
  94
  95 /*
  96 op_mode
  97 Set to 0 (HT pure) under the followign conditions
  98         - all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
  99         - all STAs in the BSS are 20 MHz HT in 20 MHz BSS
 100 Set to 1 (HT non-member protection) if there may be non-HT STAs
 101         in both the primary and the secondary channel
 102 Set to 2 if only HT STAs are associated in BSS,
 103         however and at least one 20 MHz HT STA is associated
 104 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
 105 */
 106 int hostapd_ht_operation_update(struct hostapd_iface *iface)
 107 {
 108         u16 cur_op_mode, new_op_mode;
 109         int op_mode_changes = 0;
 110
 111         if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 112                 return 0;
 113
 114         wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 115                    __func__, iface->ht_op_mode);
 116
 117         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT)
 118             && iface->num_sta_ht_no_gf) {
 119                 iface->ht_op_mode |=
 120                         HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 121                 op_mode_changes++;
 122         } else if ((iface->ht_op_mode &
 123                     HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT) &&
 124                    iface->num_sta_ht_no_gf == 0) {
 125                 iface->ht_op_mode &=
 126                         ~HT_INFO_OPERATION_MODE_NON_GF_DEVS_PRESENT;
 127                 op_mode_changes++;
 128         }
 129
 130         if (!(iface->ht_op_mode & HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 131             (iface->num_sta_no_ht || iface->olbc_ht)) {
 132                 iface->ht_op_mode |= HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 133                 op_mode_changes++;
 134         } else if ((iface->ht_op_mode &
 135                     HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT) &&
 136                    (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 137                 iface->ht_op_mode &=
 138                         ~HT_INFO_OPERATION_MODE_NON_HT_STA_PRESENT;
 139                 op_mode_changes++;
 140         }
 141
 142         new_op_mode = 0;
 143         if (iface->num_sta_no_ht)
 144                 new_op_mode = OP_MODE_MIXED;
 145         else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
 146                 new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
 147         else if (iface->olbc_ht)
 148                 new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
 149         else
 150                 new_op_mode = OP_MODE_PURE;
 151
 152         cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 153         if (cur_op_mode != new_op_mode) {
 154                 iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
 155                 iface->ht_op_mode |= new_op_mode;
 156                 op_mode_changes++;
 157         }
 158
 159         wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 160                    __func__, iface->ht_op_mode, op_mode_changes);
 161
 162         return op_mode_changes;
 163 }
 164
 165
 166 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 167                       const u8 *ht_capab, size_t ht_capab_len)
 168 {
 169         /* Disable HT caps for STAs associated to no-HT BSSes. */
 170         if (!ht_capab ||
 171             ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
 172             hapd->conf->disable_11n) {
 173                 sta->flags &= ~WLAN_STA_HT;
 174                 os_free(sta->ht_capabilities);
 175                 sta->ht_capabilities = NULL;
 176                 return WLAN_STATUS_SUCCESS;
 177         }
 178
 179         if (sta->ht_capabilities == NULL) {
 180                 sta->ht_capabilities =
 181                         os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 182                 if (sta->ht_capabilities == NULL)
 183                         return WLAN_STATUS_UNSPECIFIED_FAILURE;
 184         }
 185
 186         sta->flags |= WLAN_STA_HT;
 187         os_memcpy(sta->ht_capabilities, ht_capab,
 188                   sizeof(struct ieee80211_ht_capabilities));
 189
 190         return WLAN_STATUS_SUCCESS;
 191 }
 192
 193
 194 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 195 {
 196         u16 ht_capab;
 197
 198         ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 199         wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 200                    "0x%04x", MAC2STR(sta->addr), ht_capab);
 201         if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 202                 if (!sta->no_ht_gf_set) {
 203                         sta->no_ht_gf_set = 1;
 204                         hapd->iface->num_sta_ht_no_gf++;
 205                 }
 206                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 207                            "of non-gf stations %d",
 208                            __func__, MAC2STR(sta->addr),
 209                            hapd->iface->num_sta_ht_no_gf);
 210         }
 211         if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 212                 if (!sta->ht_20mhz_set) {
 213                         sta->ht_20mhz_set = 1;
 214                         hapd->iface->num_sta_ht_20mhz++;
 215                 }
 216                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 217                            "20MHz HT STAs %d",
 218                            __func__, MAC2STR(sta->addr),
 219                            hapd->iface->num_sta_ht_20mhz);
 220         }
 221 }
 222
 223
 224 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 225 {
 226         if (!sta->no_ht_set) {
 227                 sta->no_ht_set = 1;
 228                 hapd->iface->num_sta_no_ht++;
 229         }
 230         if (hapd->iconf->ieee80211n) {
 231                 wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 232                            "non-HT stations %d",
 233                            __func__, MAC2STR(sta->addr),
 234                            hapd->iface->num_sta_no_ht);
 235         }
 236 }
 237
 238
 239 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 240 {
 241         if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 242                 update_sta_ht(hapd, sta);
 243         else
 244                 update_sta_no_ht(hapd, sta);
 245
 246         if (hostapd_ht_operation_update(hapd->iface) > 0)
 247                 ieee802_11_set_beacons(hapd->iface);
 248 }
 249
 250
 251 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 252                           struct ieee80211_ht_capabilities *ht_cap,
 253                           struct ieee80211_ht_capabilities *neg_ht_cap)
 254 {
 255         u16 cap;
 256
 257         if (ht_cap == NULL)
 258                 return;
 259         os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 260         cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
 261
 262         /*
 263          * Mask out HT features we don't support, but don't overwrite
 264          * non-symmetric features like STBC and SMPS. Just because
 265          * we're not in dynamic SMPS mode the STA might still be.
 266          */
 267         cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
 268                 HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
 269
 270         /*
 271          * STBC needs to be handled specially
 272          * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
 273          * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
 274          */
 275         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
 276                 cap &= ~HT_CAP_INFO_TX_STBC;
 277         if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
 278                 cap &= ~HT_CAP_INFO_RX_STBC_MASK;
 279
 280         neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 281 }