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