hostap/src/ap/ieee802_11_ht.c - nest-cam/4320010/hostap - Git at Google

 /*
  * hostapd / IEEE 802.11n HT
  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
  * Copyright (c) 2007-2008, Intel Corporation
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "utils/includes.h"

 #include "utils/common.h"
 #include "utils/eloop.h"
 #include "common/ieee802_11_defs.h"
 #include "hostapd.h"
 #include "ap_config.h"
 #include "sta_info.h"
 #include "beacon.h"
 #include "ieee802_11.h"
 #include "hw_features.h"
 #include "ap_drv_ops.h"


 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
 {
 	struct ieee80211_ht_capabilities *cap;
 	u8 *pos = eid;

 	if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
 	    hapd->conf->disable_11n)
 		return eid;

 	*pos++ = WLAN_EID_HT_CAP;
 	*pos++ = sizeof(*cap);

 	cap = (struct ieee80211_ht_capabilities *) pos;
 	os_memset(cap, 0, sizeof(*cap));
 	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
 	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
 	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
 		  16);

 	/* TODO: ht_extended_capabilities (now fully disabled) */
 	/* TODO: tx_bf_capability_info (now fully disabled) */
 	/* TODO: asel_capabilities (now fully disabled) */

  	pos += sizeof(*cap);

 	if (hapd->iconf->obss_interval) {
 		struct ieee80211_obss_scan_parameters *scan_params;

 		*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
 		*pos++ = sizeof(*scan_params);

 		scan_params = (struct ieee80211_obss_scan_parameters *) pos;
 		os_memset(scan_params, 0, sizeof(*scan_params));
 		scan_params->width_trigger_scan_interval =
 			host_to_le16(hapd->iconf->obss_interval);

 		/* Fill in default values for remaining parameters
 		 * (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
 		scan_params->scan_passive_dwell =
 			host_to_le16(20);
 		scan_params->scan_active_dwell =
 			host_to_le16(10);
 		scan_params->scan_passive_total_per_channel =
 			host_to_le16(200);
 		scan_params->scan_active_total_per_channel =
 			host_to_le16(20);
 		scan_params->channel_transition_delay_factor =
 			host_to_le16(5);
 		scan_params->scan_activity_threshold =
 			host_to_le16(25);

 		pos += sizeof(*scan_params);
 	}

 	return pos;
 }


 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
 {
 	struct ieee80211_ht_operation *oper;
 	u8 *pos = eid;

 	if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
 		return eid;

 	*pos++ = WLAN_EID_HT_OPERATION;
 	*pos++ = sizeof(*oper);

 	oper = (struct ieee80211_ht_operation *) pos;
 	os_memset(oper, 0, sizeof(*oper));

 	oper->primary_chan = hapd->iconf->channel;
 	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
 	if (hapd->iconf->secondary_channel == 1)
 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
 	if (hapd->iconf->secondary_channel == -1)
 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;

 	pos += sizeof(*oper);

 	return pos;
 }


 /*
 op_mode
 Set to 0 (HT pure) under the followign conditions
 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
 Set to 1 (HT non-member protection) if there may be non-HT STAs
 	in both the primary and the secondary channel
 Set to 2 if only HT STAs are associated in BSS,
 	however and at least one 20 MHz HT STA is associated
 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
 */
 int hostapd_ht_operation_update(struct hostapd_iface *iface)
 {
 	u16 cur_op_mode, new_op_mode;
 	int op_mode_changes = 0;

 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
 		return 0;

 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
 		   __func__, iface->ht_op_mode);

 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
 	    && iface->num_sta_ht_no_gf) {
 		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 		op_mode_changes++;
 	} else if ((iface->ht_op_mode &
 		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
 		   iface->num_sta_ht_no_gf == 0) {
 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
 		op_mode_changes++;
 	}

 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
 		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 		op_mode_changes++;
 	} else if ((iface->ht_op_mode &
 		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
 		op_mode_changes++;
 	}

 	if (iface->num_sta_no_ht)
 		new_op_mode = HT_PROT_NON_HT_MIXED;
 	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
 		new_op_mode = HT_PROT_20MHZ_PROTECTION;
 	else if (iface->olbc_ht)
 		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
 	else
 		new_op_mode = HT_PROT_NO_PROTECTION;

 	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
 	if (cur_op_mode != new_op_mode) {
 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
 		iface->ht_op_mode |= new_op_mode;
 		op_mode_changes++;
 	}

 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
 		   __func__, iface->ht_op_mode, op_mode_changes);

 	return op_mode_changes;
 }


 static int is_40_allowed(struct hostapd_iface *iface, int channel)
 {
 	int pri_freq, sec_freq;
 	int affected_start, affected_end;
 	int pri = 2407 + 5 * channel;

 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 		return 1;

 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);

 	if (iface->conf->secondary_channel > 0)
 		sec_freq = pri_freq + 20;
 	else
 		sec_freq = pri_freq - 20;

 	affected_start = (pri_freq + sec_freq) / 2 - 25;
 	affected_end = (pri_freq + sec_freq) / 2 + 25;
 	if ((pri < affected_start || pri > affected_end))
 		return 1; /* not within affected channel range */

 	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
 		   affected_start, affected_end);
 	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
 	return 0;
 }


 void hostapd_2040_coex_action(struct hostapd_data *hapd,
 			      const struct ieee80211_mgmt *mgmt, size_t len)
 {
 	struct hostapd_iface *iface = hapd->iface;
 	struct ieee80211_2040_bss_coex_ie *bc_ie;
 	struct ieee80211_2040_intol_chan_report *ic_report;
 	int is_ht40_allowed = 1;
 	int i;
 	const u8 *start = (const u8 *) mgmt;
 	const u8 *data = start + IEEE80211_HDRLEN + 2;

 	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
 		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
 		       mgmt->u.action.u.public_action.action);

 	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
 		return;

 	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
 		return;

 	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
 	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
 	    bc_ie->length < 1) {
 		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
 			   bc_ie->element_id, bc_ie->length);
 		return;
 	}
 	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
 		return;
 	data += 2 + bc_ie->length;

 	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
 		   bc_ie->coex_param);
 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
 		hostapd_logger(hapd, mgmt->sa,
 			       HOSTAPD_MODULE_IEEE80211,
 			       HOSTAPD_LEVEL_DEBUG,
 			       "20 MHz BSS width request bit is set in BSS coexistence information field");
 		is_ht40_allowed = 0;
 	}

 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
 		hostapd_logger(hapd, mgmt->sa,
 			       HOSTAPD_MODULE_IEEE80211,
 			       HOSTAPD_LEVEL_DEBUG,
 			       "40 MHz intolerant bit is set in BSS coexistence information field");
 		is_ht40_allowed = 0;
 	}

 	if (start + len - data >= 3 &&
 	    data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
 		u8 ielen = data[1];

 		if (ielen > start + len - data - 2)
 			return;
 		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
 		wpa_printf(MSG_DEBUG,
 			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
 			   ic_report->op_class);

 		/* Go through the channel report to find any BSS there in the
 		 * affected channel range */
 		for (i = 0; i < ielen - 1; i++) {
 			u8 chan = ic_report->variable[i];

 			if (is_40_allowed(iface, chan))
 				continue;
 			hostapd_logger(hapd, mgmt->sa,
 				       HOSTAPD_MODULE_IEEE80211,
 				       HOSTAPD_LEVEL_DEBUG,
 				       "20_40_INTOLERANT channel %d reported",
 				       chan);
 			is_ht40_allowed = 0;
 		}
 	}
 	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
 		   is_ht40_allowed, iface->num_sta_ht40_intolerant);

 	if (!is_ht40_allowed &&
 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 		if (iface->conf->secondary_channel) {
 			hostapd_logger(hapd, mgmt->sa,
 				       HOSTAPD_MODULE_IEEE80211,
 				       HOSTAPD_LEVEL_INFO,
 				       "Switching to 20 MHz operation");
 			iface->conf->secondary_channel = 0;
 			ieee802_11_set_beacons(iface);
 		}
 		if (!iface->num_sta_ht40_intolerant &&
 		    iface->conf->obss_interval) {
 			unsigned int delay_time;
 			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 				iface->conf->obss_interval;
 			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
 					     NULL);
 			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 					       hapd->iface, NULL);
 			wpa_printf(MSG_DEBUG,
 				   "Reschedule HT 20/40 timeout to occur in %u seconds",
 				   delay_time);
 		}
 	}
 }


 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 		      const u8 *ht_capab)
 {
 	/*
 	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
 	 * that did not specify a valid WMM IE in the (Re)Association Request
 	 * frame.
 	 */
 	if (!ht_capab ||
 	    !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
 		sta->flags &= ~WLAN_STA_HT;
 		os_free(sta->ht_capabilities);
 		sta->ht_capabilities = NULL;
 		return WLAN_STATUS_SUCCESS;
 	}

 	if (sta->ht_capabilities == NULL) {
 		sta->ht_capabilities =
 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
 		if (sta->ht_capabilities == NULL)
 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
 	}

 	sta->flags |= WLAN_STA_HT;
 	os_memcpy(sta->ht_capabilities, ht_capab,
 		  sizeof(struct ieee80211_ht_capabilities));

 	return WLAN_STATUS_SUCCESS;
 }


 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
 {
 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
 		return;

 	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
 		   " in Association Request", MAC2STR(sta->addr));

 	if (sta->ht40_intolerant_set)
 		return;

 	sta->ht40_intolerant_set = 1;
 	iface->num_sta_ht40_intolerant++;
 	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);

 	if (iface->conf->secondary_channel &&
 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 		iface->conf->secondary_channel = 0;
 		ieee802_11_set_beacons(iface);
 	}
 }


 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
 {
 	if (!sta->ht40_intolerant_set)
 		return;

 	sta->ht40_intolerant_set = 0;
 	iface->num_sta_ht40_intolerant--;

 	if (iface->num_sta_ht40_intolerant == 0 &&
 	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
 		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
 			iface->conf->obss_interval;
 		wpa_printf(MSG_DEBUG,
 			   "HT: Start 20->40 MHz transition timer (%d seconds)",
 			   delay_time);
 		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
 		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
 				       iface, NULL);
 	}
 }


 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
 {
 	u16 ht_capab;

 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
 		if (!sta->no_ht_gf_set) {
 			sta->no_ht_gf_set = 1;
 			hapd->iface->num_sta_ht_no_gf++;
 		}
 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
 			   "of non-gf stations %d",
 			   __func__, MAC2STR(sta->addr),
 			   hapd->iface->num_sta_ht_no_gf);
 	}
 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
 		if (!sta->ht_20mhz_set) {
 			sta->ht_20mhz_set = 1;
 			hapd->iface->num_sta_ht_20mhz++;
 		}
 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
 			   "20MHz HT STAs %d",
 			   __func__, MAC2STR(sta->addr),
 			   hapd->iface->num_sta_ht_20mhz);
 	}

 	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
 		ht40_intolerant_add(hapd->iface, sta);
 }


 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
 {
 	if (!sta->no_ht_set) {
 		sta->no_ht_set = 1;
 		hapd->iface->num_sta_no_ht++;
 	}
 	if (hapd->iconf->ieee80211n) {
 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
 			   "non-HT stations %d",
 			   __func__, MAC2STR(sta->addr),
 			   hapd->iface->num_sta_no_ht);
 	}
 }


 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
 {
 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
 		update_sta_ht(hapd, sta);
 	else
 		update_sta_no_ht(hapd, sta);

 	if (hostapd_ht_operation_update(hapd->iface) > 0)
 		ieee802_11_set_beacons(hapd->iface);
 }


 void hostapd_get_ht_capab(struct hostapd_data *hapd,
 			  struct ieee80211_ht_capabilities *ht_cap,
 			  struct ieee80211_ht_capabilities *neg_ht_cap)
 {
 	u16 cap;

 	if (ht_cap == NULL)
 		return;
 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);

 	/*
 	 * Mask out HT features we don't support, but don't overwrite
 	 * non-symmetric features like STBC and SMPS. Just because
 	 * we're not in dynamic SMPS mode the STA might still be.
 	 */
 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);

 	/*
 	 * STBC needs to be handled specially
 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
 	 */
 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
 		cap &= ~HT_CAP_INFO_TX_STBC;
 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;

 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
 }


 void ap_ht2040_timeout(void *eloop_data, void *user_data)
 {
 	struct hostapd_iface *iface = eloop_data;

 	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");

 	iface->conf->secondary_channel = iface->secondary_ch;
 	ieee802_11_set_beacons(iface);
 }
	/*
	* hostapd / IEEE 802.11n HT
	* Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
	* Copyright (c) 2007-2008, Intel Corporation
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "utils/includes.h"

	#include "utils/common.h"
	#include "utils/eloop.h"
	#include "common/ieee802_11_defs.h"
	#include "hostapd.h"
	#include "ap_config.h"
	#include "sta_info.h"
	#include "beacon.h"
	#include "ieee802_11.h"
	#include "hw_features.h"
	#include "ap_drv_ops.h"


	u8 * hostapd_eid_ht_capabilities(struct hostapd_data hapd, u8 eid)
	{
	struct ieee80211_ht_capabilities *cap;
	u8 *pos = eid;

	if (!hapd->iconf->ieee80211n \|\| !hapd->iface->current_mode \|\|
	hapd->conf->disable_11n)
	return eid;

	*pos++ = WLAN_EID_HT_CAP;
	pos++ = sizeof(cap);

	cap = (struct ieee80211_ht_capabilities *) pos;
	os_memset(cap, 0, sizeof(*cap));
	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
	16);

	/* TODO: ht_extended_capabilities (now fully disabled) */
	/* TODO: tx_bf_capability_info (now fully disabled) */
	/* TODO: asel_capabilities (now fully disabled) */

	pos += sizeof(*cap);

	if (hapd->iconf->obss_interval) {
	struct ieee80211_obss_scan_parameters *scan_params;

	*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
	pos++ = sizeof(scan_params);

	scan_params = (struct ieee80211_obss_scan_parameters *) pos;
	os_memset(scan_params, 0, sizeof(*scan_params));
	scan_params->width_trigger_scan_interval =
	host_to_le16(hapd->iconf->obss_interval);

	/* Fill in default values for remaining parameters
	* (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
	scan_params->scan_passive_dwell =
	host_to_le16(20);
	scan_params->scan_active_dwell =
	host_to_le16(10);
	scan_params->scan_passive_total_per_channel =
	host_to_le16(200);
	scan_params->scan_active_total_per_channel =
	host_to_le16(20);
	scan_params->channel_transition_delay_factor =
	host_to_le16(5);
	scan_params->scan_activity_threshold =
	host_to_le16(25);

	pos += sizeof(*scan_params);
	}

	return pos;
	}


	u8 * hostapd_eid_ht_operation(struct hostapd_data hapd, u8 eid)
	{
	struct ieee80211_ht_operation *oper;
	u8 *pos = eid;

	if (!hapd->iconf->ieee80211n \|\| hapd->conf->disable_11n)
	return eid;

	*pos++ = WLAN_EID_HT_OPERATION;
	pos++ = sizeof(oper);

	oper = (struct ieee80211_ht_operation *) pos;
	os_memset(oper, 0, sizeof(*oper));

	oper->primary_chan = hapd->iconf->channel;
	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
	if (hapd->iconf->secondary_channel == 1)
	oper->ht_param \|= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE \|
	HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
	if (hapd->iconf->secondary_channel == -1)
	oper->ht_param \|= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW \|
	HT_INFO_HT_PARAM_STA_CHNL_WIDTH;

	pos += sizeof(*oper);

	return pos;
	}


	/*
	op_mode
	Set to 0 (HT pure) under the followign conditions
	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
	Set to 1 (HT non-member protection) if there may be non-HT STAs
	in both the primary and the secondary channel
	Set to 2 if only HT STAs are associated in BSS,
	however and at least one 20 MHz HT STA is associated
	Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
	*/
	int hostapd_ht_operation_update(struct hostapd_iface *iface)
	{
	u16 cur_op_mode, new_op_mode;
	int op_mode_changes = 0;

	if (!iface->conf->ieee80211n \|\| iface->conf->ht_op_mode_fixed)
	return 0;

	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
	__func__, iface->ht_op_mode);

	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
	&& iface->num_sta_ht_no_gf) {
	iface->ht_op_mode \|= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
	op_mode_changes++;
	} else if ((iface->ht_op_mode &
	HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
	iface->num_sta_ht_no_gf == 0) {
	iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
	op_mode_changes++;
	}

	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
	(iface->num_sta_no_ht \|\| iface->olbc_ht)) {
	iface->ht_op_mode \|= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
	op_mode_changes++;
	} else if ((iface->ht_op_mode &
	HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
	(iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
	iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
	op_mode_changes++;
	}

	if (iface->num_sta_no_ht)
	new_op_mode = HT_PROT_NON_HT_MIXED;
	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
	new_op_mode = HT_PROT_20MHZ_PROTECTION;
	else if (iface->olbc_ht)
	new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
	else
	new_op_mode = HT_PROT_NO_PROTECTION;

	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
	if (cur_op_mode != new_op_mode) {
	iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
	iface->ht_op_mode \|= new_op_mode;
	op_mode_changes++;
	}

	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
	__func__, iface->ht_op_mode, op_mode_changes);

	return op_mode_changes;
	}


	static int is_40_allowed(struct hostapd_iface *iface, int channel)
	{
	int pri_freq, sec_freq;
	int affected_start, affected_end;
	int pri = 2407 + 5 * channel;

	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
	return 1;

	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);

	if (iface->conf->secondary_channel > 0)
	sec_freq = pri_freq + 20;
	else
	sec_freq = pri_freq - 20;

	affected_start = (pri_freq + sec_freq) / 2 - 25;
	affected_end = (pri_freq + sec_freq) / 2 + 25;
	if ((pri < affected_start \|\| pri > affected_end))
	return 1; /* not within affected channel range */

	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
	affected_start, affected_end);
	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
	return 0;
	}


	void hostapd_2040_coex_action(struct hostapd_data *hapd,
	const struct ieee80211_mgmt *mgmt, size_t len)
	{
	struct hostapd_iface *iface = hapd->iface;
	struct ieee80211_2040_bss_coex_ie *bc_ie;
	struct ieee80211_2040_intol_chan_report *ic_report;
	int is_ht40_allowed = 1;
	int i;
	const u8 start = (const u8 ) mgmt;
	const u8 *data = start + IEEE80211_HDRLEN + 2;

	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
	HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
	mgmt->u.action.u.public_action.action);

	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
	return;

	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
	return;

	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE \|\|
	bc_ie->length < 1) {
	wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
	bc_ie->element_id, bc_ie->length);
	return;
	}
	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
	return;
	data += 2 + bc_ie->length;

	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
	bc_ie->coex_param);
	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
	hostapd_logger(hapd, mgmt->sa,
	HOSTAPD_MODULE_IEEE80211,
	HOSTAPD_LEVEL_DEBUG,
	"20 MHz BSS width request bit is set in BSS coexistence information field");
	is_ht40_allowed = 0;
	}

	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
	hostapd_logger(hapd, mgmt->sa,
	HOSTAPD_MODULE_IEEE80211,
	HOSTAPD_LEVEL_DEBUG,
	"40 MHz intolerant bit is set in BSS coexistence information field");
	is_ht40_allowed = 0;
	}

	if (start + len - data >= 3 &&
	data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
	u8 ielen = data[1];

	if (ielen > start + len - data - 2)
	return;
	ic_report = (struct ieee80211_2040_intol_chan_report *) data;
	wpa_printf(MSG_DEBUG,
	"20/40 BSS Intolerant Channel Report: Operating Class %u",
	ic_report->op_class);

	/* Go through the channel report to find any BSS there in the
	* affected channel range */
	for (i = 0; i < ielen - 1; i++) {
	u8 chan = ic_report->variable[i];

	if (is_40_allowed(iface, chan))
	continue;
	hostapd_logger(hapd, mgmt->sa,
	HOSTAPD_MODULE_IEEE80211,
	HOSTAPD_LEVEL_DEBUG,
	"20_40_INTOLERANT channel %d reported",
	chan);
	is_ht40_allowed = 0;
	}
	}
	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
	is_ht40_allowed, iface->num_sta_ht40_intolerant);

	if (!is_ht40_allowed &&
	(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
	if (iface->conf->secondary_channel) {
	hostapd_logger(hapd, mgmt->sa,
	HOSTAPD_MODULE_IEEE80211,
	HOSTAPD_LEVEL_INFO,
	"Switching to 20 MHz operation");
	iface->conf->secondary_channel = 0;
	ieee802_11_set_beacons(iface);
	}
	if (!iface->num_sta_ht40_intolerant &&
	iface->conf->obss_interval) {
	unsigned int delay_time;
	delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
	iface->conf->obss_interval;
	eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
	NULL);
	eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
	hapd->iface, NULL);
	wpa_printf(MSG_DEBUG,
	"Reschedule HT 20/40 timeout to occur in %u seconds",
	delay_time);
	}
	}
	}


	u16 copy_sta_ht_capab(struct hostapd_data hapd, struct sta_info sta,
	const u8 *ht_capab)
	{
	/*
	* Disable HT caps for STAs associated to no-HT BSSes, or for stations
	* that did not specify a valid WMM IE in the (Re)Association Request
	* frame.
	*/
	if (!ht_capab \|\|
	!(sta->flags & WLAN_STA_WMM) \|\| hapd->conf->disable_11n) {
	sta->flags &= ~WLAN_STA_HT;
	os_free(sta->ht_capabilities);
	sta->ht_capabilities = NULL;
	return WLAN_STATUS_SUCCESS;
	}

	if (sta->ht_capabilities == NULL) {
	sta->ht_capabilities =
	os_zalloc(sizeof(struct ieee80211_ht_capabilities));
	if (sta->ht_capabilities == NULL)
	return WLAN_STATUS_UNSPECIFIED_FAILURE;
	}

	sta->flags \|= WLAN_STA_HT;
	os_memcpy(sta->ht_capabilities, ht_capab,
	sizeof(struct ieee80211_ht_capabilities));

	return WLAN_STATUS_SUCCESS;
	}


	void ht40_intolerant_add(struct hostapd_iface iface, struct sta_info sta)
	{
	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
	return;

	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
	" in Association Request", MAC2STR(sta->addr));

	if (sta->ht40_intolerant_set)
	return;

	sta->ht40_intolerant_set = 1;
	iface->num_sta_ht40_intolerant++;
	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);

	if (iface->conf->secondary_channel &&
	(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
	iface->conf->secondary_channel = 0;
	ieee802_11_set_beacons(iface);
	}
	}


	void ht40_intolerant_remove(struct hostapd_iface iface, struct sta_info sta)
	{
	if (!sta->ht40_intolerant_set)
	return;

	sta->ht40_intolerant_set = 0;
	iface->num_sta_ht40_intolerant--;

	if (iface->num_sta_ht40_intolerant == 0 &&
	(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
	(iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
	unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
	iface->conf->obss_interval;
	wpa_printf(MSG_DEBUG,
	"HT: Start 20->40 MHz transition timer (%d seconds)",
	delay_time);
	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
	eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
	iface, NULL);
	}
	}


	static void update_sta_ht(struct hostapd_data hapd, struct sta_info sta)
	{
	u16 ht_capab;

	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
	"0x%04x", MAC2STR(sta->addr), ht_capab);
	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
	if (!sta->no_ht_gf_set) {
	sta->no_ht_gf_set = 1;
	hapd->iface->num_sta_ht_no_gf++;
	}
	wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
	"of non-gf stations %d",
	__func__, MAC2STR(sta->addr),
	hapd->iface->num_sta_ht_no_gf);
	}
	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
	if (!sta->ht_20mhz_set) {
	sta->ht_20mhz_set = 1;
	hapd->iface->num_sta_ht_20mhz++;
	}
	wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
	"20MHz HT STAs %d",
	__func__, MAC2STR(sta->addr),
	hapd->iface->num_sta_ht_20mhz);
	}

	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
	ht40_intolerant_add(hapd->iface, sta);
	}


	static void update_sta_no_ht(struct hostapd_data hapd, struct sta_info sta)
	{
	if (!sta->no_ht_set) {
	sta->no_ht_set = 1;
	hapd->iface->num_sta_no_ht++;
	}
	if (hapd->iconf->ieee80211n) {
	wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
	"non-HT stations %d",
	__func__, MAC2STR(sta->addr),
	hapd->iface->num_sta_no_ht);
	}
	}


	void update_ht_state(struct hostapd_data hapd, struct sta_info sta)
	{
	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
	update_sta_ht(hapd, sta);
	else
	update_sta_no_ht(hapd, sta);

	if (hostapd_ht_operation_update(hapd->iface) > 0)
	ieee802_11_set_beacons(hapd->iface);
	}


	void hostapd_get_ht_capab(struct hostapd_data *hapd,
	struct ieee80211_ht_capabilities *ht_cap,
	struct ieee80211_ht_capabilities *neg_ht_cap)
	{
	u16 cap;

	if (ht_cap == NULL)
	return;
	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);

	/*
	* Mask out HT features we don't support, but don't overwrite
	* non-symmetric features like STBC and SMPS. Just because
	* we're not in dynamic SMPS mode the STA might still be.
	*/
	cap &= (hapd->iconf->ht_capab \| HT_CAP_INFO_RX_STBC_MASK \|
	HT_CAP_INFO_TX_STBC \| HT_CAP_INFO_SMPS_MASK);

	/*
	* STBC needs to be handled specially
	* if we don't support RX STBC, mask out TX STBC in the STA's HT caps
	* if we don't support TX STBC, mask out RX STBC in the STA's HT caps
	*/
	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
	cap &= ~HT_CAP_INFO_TX_STBC;
	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
	cap &= ~HT_CAP_INFO_RX_STBC_MASK;

	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
	}


	void ap_ht2040_timeout(void eloop_data, void user_data)
	{
	struct hostapd_iface *iface = eloop_data;

	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");

	iface->conf->secondary_channel = iface->secondary_ch;
	ieee802_11_set_beacons(iface);
	}