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      1 /*
      2  * hostapd / IEEE 802.11n HT
      3  * Copyright (c) 2002-2009, Jouni Malinen <j (at) 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->secondary_channel && iface->num_sta_ht_20mhz)
    137 		new_op_mode = OP_MODE_20MHZ_HT_STA_ASSOCED;
    138 	else if (iface->olbc_ht)
    139 		new_op_mode = OP_MODE_MAY_BE_LEGACY_STAS;
    140 	else
    141 		new_op_mode = OP_MODE_PURE;
    142 
    143 	cur_op_mode = iface->ht_op_mode & HT_INFO_OPERATION_MODE_OP_MODE_MASK;
    144 	if (cur_op_mode != new_op_mode) {
    145 		iface->ht_op_mode &= ~HT_INFO_OPERATION_MODE_OP_MODE_MASK;
    146 		iface->ht_op_mode |= new_op_mode;
    147 		op_mode_changes++;
    148 	}
    149 
    150 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
    151 		   __func__, iface->ht_op_mode, op_mode_changes);
    152 
    153 	return op_mode_changes;
    154 }
    155 
    156 
    157 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
    158 		      const u8 *ht_capab, size_t ht_capab_len)
    159 {
    160 	/* Disable HT caps for STAs associated to no-HT BSSes. */
    161 	if (!ht_capab ||
    162 	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
    163 	    hapd->conf->disable_11n) {
    164 		sta->flags &= ~WLAN_STA_HT;
    165 		os_free(sta->ht_capabilities);
    166 		sta->ht_capabilities = NULL;
    167 		return WLAN_STATUS_SUCCESS;
    168 	}
    169 
    170 	if (sta->ht_capabilities == NULL) {
    171 		sta->ht_capabilities =
    172 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
    173 		if (sta->ht_capabilities == NULL)
    174 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
    175 	}
    176 
    177 	sta->flags |= WLAN_STA_HT;
    178 	os_memcpy(sta->ht_capabilities, ht_capab,
    179 		  sizeof(struct ieee80211_ht_capabilities));
    180 
    181 	return WLAN_STATUS_SUCCESS;
    182 }
    183 
    184 
    185 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
    186 {
    187 	u16 ht_capab;
    188 
    189 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
    190 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
    191 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
    192 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
    193 		if (!sta->no_ht_gf_set) {
    194 			sta->no_ht_gf_set = 1;
    195 			hapd->iface->num_sta_ht_no_gf++;
    196 		}
    197 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
    198 			   "of non-gf stations %d",
    199 			   __func__, MAC2STR(sta->addr),
    200 			   hapd->iface->num_sta_ht_no_gf);
    201 	}
    202 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
    203 		if (!sta->ht_20mhz_set) {
    204 			sta->ht_20mhz_set = 1;
    205 			hapd->iface->num_sta_ht_20mhz++;
    206 		}
    207 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
    208 			   "20MHz HT STAs %d",
    209 			   __func__, MAC2STR(sta->addr),
    210 			   hapd->iface->num_sta_ht_20mhz);
    211 	}
    212 }
    213 
    214 
    215 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
    216 {
    217 	if (!sta->no_ht_set) {
    218 		sta->no_ht_set = 1;
    219 		hapd->iface->num_sta_no_ht++;
    220 	}
    221 	if (hapd->iconf->ieee80211n) {
    222 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
    223 			   "non-HT stations %d",
    224 			   __func__, MAC2STR(sta->addr),
    225 			   hapd->iface->num_sta_no_ht);
    226 	}
    227 }
    228 
    229 
    230 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
    231 {
    232 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
    233 		update_sta_ht(hapd, sta);
    234 	else
    235 		update_sta_no_ht(hapd, sta);
    236 
    237 	if (hostapd_ht_operation_update(hapd->iface) > 0)
    238 		ieee802_11_set_beacons(hapd->iface);
    239 }
    240 
    241 
    242 void hostapd_get_ht_capab(struct hostapd_data *hapd,
    243 			  struct ieee80211_ht_capabilities *ht_cap,
    244 			  struct ieee80211_ht_capabilities *neg_ht_cap)
    245 {
    246 	u16 cap;
    247 
    248 	if (ht_cap == NULL)
    249 		return;
    250 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
    251 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
    252 
    253 	/*
    254 	 * Mask out HT features we don't support, but don't overwrite
    255 	 * non-symmetric features like STBC and SMPS. Just because
    256 	 * we're not in dynamic SMPS mode the STA might still be.
    257 	 */
    258 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
    259 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
    260 
    261 	/*
    262 	 * STBC needs to be handled specially
    263 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
    264 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
    265 	 */
    266 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
    267 		cap &= ~HT_CAP_INFO_TX_STBC;
    268 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
    269 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
    270 
    271 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
    272 }
    273