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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 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 "utils/eloop.h"
     14 #include "common/ieee802_11_defs.h"
     15 #include "hostapd.h"
     16 #include "ap_config.h"
     17 #include "sta_info.h"
     18 #include "beacon.h"
     19 #include "ieee802_11.h"
     20 #include "hw_features.h"
     21 #include "ap_drv_ops.h"
     22 
     23 
     24 u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
     25 {
     26 	struct ieee80211_ht_capabilities *cap;
     27 	u8 *pos = eid;
     28 
     29 	if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
     30 	    hapd->conf->disable_11n)
     31 		return eid;
     32 
     33 	*pos++ = WLAN_EID_HT_CAP;
     34 	*pos++ = sizeof(*cap);
     35 
     36 	cap = (struct ieee80211_ht_capabilities *) pos;
     37 	os_memset(cap, 0, sizeof(*cap));
     38 	cap->ht_capabilities_info = host_to_le16(hapd->iconf->ht_capab);
     39 	cap->a_mpdu_params = hapd->iface->current_mode->a_mpdu_params;
     40 	os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
     41 		  16);
     42 
     43 	/* TODO: ht_extended_capabilities (now fully disabled) */
     44 	/* TODO: tx_bf_capability_info (now fully disabled) */
     45 	/* TODO: asel_capabilities (now fully disabled) */
     46 
     47  	pos += sizeof(*cap);
     48 
     49 	if (hapd->iconf->obss_interval) {
     50 		struct ieee80211_obss_scan_parameters *scan_params;
     51 
     52 		*pos++ = WLAN_EID_OVERLAPPING_BSS_SCAN_PARAMS;
     53 		*pos++ = sizeof(*scan_params);
     54 
     55 		scan_params = (struct ieee80211_obss_scan_parameters *) pos;
     56 		os_memset(scan_params, 0, sizeof(*scan_params));
     57 		scan_params->width_trigger_scan_interval =
     58 			host_to_le16(hapd->iconf->obss_interval);
     59 
     60 		/* Fill in default values for remaining parameters
     61 		 * (IEEE Std 802.11-2012, 8.4.2.61 and MIB defval) */
     62 		scan_params->scan_passive_dwell =
     63 			host_to_le16(20);
     64 		scan_params->scan_active_dwell =
     65 			host_to_le16(10);
     66 		scan_params->scan_passive_total_per_channel =
     67 			host_to_le16(200);
     68 		scan_params->scan_active_total_per_channel =
     69 			host_to_le16(20);
     70 		scan_params->channel_transition_delay_factor =
     71 			host_to_le16(5);
     72 		scan_params->scan_activity_threshold =
     73 			host_to_le16(25);
     74 
     75 		pos += sizeof(*scan_params);
     76 	}
     77 
     78 	return pos;
     79 }
     80 
     81 
     82 u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
     83 {
     84 	struct ieee80211_ht_operation *oper;
     85 	u8 *pos = eid;
     86 
     87 	if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n)
     88 		return eid;
     89 
     90 	*pos++ = WLAN_EID_HT_OPERATION;
     91 	*pos++ = sizeof(*oper);
     92 
     93 	oper = (struct ieee80211_ht_operation *) pos;
     94 	os_memset(oper, 0, sizeof(*oper));
     95 
     96 	oper->primary_chan = hapd->iconf->channel;
     97 	oper->operation_mode = host_to_le16(hapd->iface->ht_op_mode);
     98 	if (hapd->iconf->secondary_channel == 1)
     99 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE |
    100 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
    101 	if (hapd->iconf->secondary_channel == -1)
    102 		oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
    103 			HT_INFO_HT_PARAM_STA_CHNL_WIDTH;
    104 
    105 	pos += sizeof(*oper);
    106 
    107 	return pos;
    108 }
    109 
    110 
    111 /*
    112 op_mode
    113 Set to 0 (HT pure) under the followign conditions
    114 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
    115 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
    116 Set to 1 (HT non-member protection) if there may be non-HT STAs
    117 	in both the primary and the secondary channel
    118 Set to 2 if only HT STAs are associated in BSS,
    119 	however and at least one 20 MHz HT STA is associated
    120 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
    121 */
    122 int hostapd_ht_operation_update(struct hostapd_iface *iface)
    123 {
    124 	u16 cur_op_mode, new_op_mode;
    125 	int op_mode_changes = 0;
    126 
    127 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
    128 		return 0;
    129 
    130 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
    131 		   __func__, iface->ht_op_mode);
    132 
    133 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
    134 	    && iface->num_sta_ht_no_gf) {
    135 		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
    136 		op_mode_changes++;
    137 	} else if ((iface->ht_op_mode &
    138 		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
    139 		   iface->num_sta_ht_no_gf == 0) {
    140 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
    141 		op_mode_changes++;
    142 	}
    143 
    144 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
    145 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
    146 		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
    147 		op_mode_changes++;
    148 	} else if ((iface->ht_op_mode &
    149 		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
    150 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
    151 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
    152 		op_mode_changes++;
    153 	}
    154 
    155 	if (iface->num_sta_no_ht)
    156 		new_op_mode = HT_PROT_NON_HT_MIXED;
    157 	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
    158 		new_op_mode = HT_PROT_20MHZ_PROTECTION;
    159 	else if (iface->olbc_ht)
    160 		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
    161 	else
    162 		new_op_mode = HT_PROT_NO_PROTECTION;
    163 
    164 	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
    165 	if (cur_op_mode != new_op_mode) {
    166 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
    167 		iface->ht_op_mode |= new_op_mode;
    168 		op_mode_changes++;
    169 	}
    170 
    171 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
    172 		   __func__, iface->ht_op_mode, op_mode_changes);
    173 
    174 	return op_mode_changes;
    175 }
    176 
    177 
    178 static int is_40_allowed(struct hostapd_iface *iface, int channel)
    179 {
    180 	int pri_freq, sec_freq;
    181 	int affected_start, affected_end;
    182 	int pri = 2407 + 5 * channel;
    183 
    184 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
    185 		return 1;
    186 
    187 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
    188 
    189 	if (iface->conf->secondary_channel > 0)
    190 		sec_freq = pri_freq + 20;
    191 	else
    192 		sec_freq = pri_freq - 20;
    193 
    194 	affected_start = (pri_freq + sec_freq) / 2 - 25;
    195 	affected_end = (pri_freq + sec_freq) / 2 + 25;
    196 	if ((pri < affected_start || pri > affected_end))
    197 		return 1; /* not within affected channel range */
    198 
    199 	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
    200 		   affected_start, affected_end);
    201 	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
    202 	return 0;
    203 }
    204 
    205 
    206 void hostapd_2040_coex_action(struct hostapd_data *hapd,
    207 			      const struct ieee80211_mgmt *mgmt, size_t len)
    208 {
    209 	struct hostapd_iface *iface = hapd->iface;
    210 	struct ieee80211_2040_bss_coex_ie *bc_ie;
    211 	struct ieee80211_2040_intol_chan_report *ic_report;
    212 	int is_ht40_allowed = 1;
    213 	int i;
    214 	const u8 *start = (const u8 *) mgmt;
    215 	const u8 *data = start + IEEE80211_HDRLEN + 2;
    216 
    217 	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
    218 		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
    219 		       mgmt->u.action.u.public_action.action);
    220 
    221 	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
    222 		return;
    223 
    224 	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
    225 		return;
    226 
    227 	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
    228 	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
    229 	    bc_ie->length < 1) {
    230 		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
    231 			   bc_ie->element_id, bc_ie->length);
    232 		return;
    233 	}
    234 	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
    235 		return;
    236 	data += 2 + bc_ie->length;
    237 
    238 	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
    239 		   bc_ie->coex_param);
    240 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
    241 		hostapd_logger(hapd, mgmt->sa,
    242 			       HOSTAPD_MODULE_IEEE80211,
    243 			       HOSTAPD_LEVEL_DEBUG,
    244 			       "20 MHz BSS width request bit is set in BSS coexistence information field");
    245 		is_ht40_allowed = 0;
    246 	}
    247 
    248 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
    249 		hostapd_logger(hapd, mgmt->sa,
    250 			       HOSTAPD_MODULE_IEEE80211,
    251 			       HOSTAPD_LEVEL_DEBUG,
    252 			       "40 MHz intolerant bit is set in BSS coexistence information field");
    253 		is_ht40_allowed = 0;
    254 	}
    255 
    256 	if (start + len - data >= 3 &&
    257 	    data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
    258 		u8 ielen = data[1];
    259 
    260 		if (ielen > start + len - data - 2)
    261 			return;
    262 		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
    263 		wpa_printf(MSG_DEBUG,
    264 			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
    265 			   ic_report->op_class);
    266 
    267 		/* Go through the channel report to find any BSS there in the
    268 		 * affected channel range */
    269 		for (i = 0; i < ielen - 1; i++) {
    270 			u8 chan = ic_report->variable[i];
    271 
    272 			if (is_40_allowed(iface, chan))
    273 				continue;
    274 			hostapd_logger(hapd, mgmt->sa,
    275 				       HOSTAPD_MODULE_IEEE80211,
    276 				       HOSTAPD_LEVEL_DEBUG,
    277 				       "20_40_INTOLERANT channel %d reported",
    278 				       chan);
    279 			is_ht40_allowed = 0;
    280 		}
    281 	}
    282 	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
    283 		   is_ht40_allowed, iface->num_sta_ht40_intolerant);
    284 
    285 	if (!is_ht40_allowed &&
    286 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    287 		if (iface->conf->secondary_channel) {
    288 			hostapd_logger(hapd, mgmt->sa,
    289 				       HOSTAPD_MODULE_IEEE80211,
    290 				       HOSTAPD_LEVEL_INFO,
    291 				       "Switching to 20 MHz operation");
    292 			iface->conf->secondary_channel = 0;
    293 			ieee802_11_set_beacons(iface);
    294 		}
    295 		if (!iface->num_sta_ht40_intolerant &&
    296 		    iface->conf->obss_interval) {
    297 			unsigned int delay_time;
    298 			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
    299 				iface->conf->obss_interval;
    300 			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
    301 					     NULL);
    302 			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
    303 					       hapd->iface, NULL);
    304 			wpa_printf(MSG_DEBUG,
    305 				   "Reschedule HT 20/40 timeout to occur in %u seconds",
    306 				   delay_time);
    307 		}
    308 	}
    309 }
    310 
    311 
    312 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
    313 		      const u8 *ht_capab)
    314 {
    315 	/*
    316 	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
    317 	 * that did not specify a valid WMM IE in the (Re)Association Request
    318 	 * frame.
    319 	 */
    320 	if (!ht_capab ||
    321 	    !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
    322 		sta->flags &= ~WLAN_STA_HT;
    323 		os_free(sta->ht_capabilities);
    324 		sta->ht_capabilities = NULL;
    325 		return WLAN_STATUS_SUCCESS;
    326 	}
    327 
    328 	if (sta->ht_capabilities == NULL) {
    329 		sta->ht_capabilities =
    330 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
    331 		if (sta->ht_capabilities == NULL)
    332 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
    333 	}
    334 
    335 	sta->flags |= WLAN_STA_HT;
    336 	os_memcpy(sta->ht_capabilities, ht_capab,
    337 		  sizeof(struct ieee80211_ht_capabilities));
    338 
    339 	return WLAN_STATUS_SUCCESS;
    340 }
    341 
    342 
    343 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
    344 {
    345 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
    346 		return;
    347 
    348 	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
    349 		   " in Association Request", MAC2STR(sta->addr));
    350 
    351 	if (sta->ht40_intolerant_set)
    352 		return;
    353 
    354 	sta->ht40_intolerant_set = 1;
    355 	iface->num_sta_ht40_intolerant++;
    356 	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
    357 
    358 	if (iface->conf->secondary_channel &&
    359 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    360 		iface->conf->secondary_channel = 0;
    361 		ieee802_11_set_beacons(iface);
    362 	}
    363 }
    364 
    365 
    366 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
    367 {
    368 	if (!sta->ht40_intolerant_set)
    369 		return;
    370 
    371 	sta->ht40_intolerant_set = 0;
    372 	iface->num_sta_ht40_intolerant--;
    373 
    374 	if (iface->num_sta_ht40_intolerant == 0 &&
    375 	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
    376 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    377 		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
    378 			iface->conf->obss_interval;
    379 		wpa_printf(MSG_DEBUG,
    380 			   "HT: Start 20->40 MHz transition timer (%d seconds)",
    381 			   delay_time);
    382 		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
    383 		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
    384 				       iface, NULL);
    385 	}
    386 }
    387 
    388 
    389 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
    390 {
    391 	u16 ht_capab;
    392 
    393 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
    394 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
    395 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
    396 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
    397 		if (!sta->no_ht_gf_set) {
    398 			sta->no_ht_gf_set = 1;
    399 			hapd->iface->num_sta_ht_no_gf++;
    400 		}
    401 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
    402 			   "of non-gf stations %d",
    403 			   __func__, MAC2STR(sta->addr),
    404 			   hapd->iface->num_sta_ht_no_gf);
    405 	}
    406 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
    407 		if (!sta->ht_20mhz_set) {
    408 			sta->ht_20mhz_set = 1;
    409 			hapd->iface->num_sta_ht_20mhz++;
    410 		}
    411 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
    412 			   "20MHz HT STAs %d",
    413 			   __func__, MAC2STR(sta->addr),
    414 			   hapd->iface->num_sta_ht_20mhz);
    415 	}
    416 
    417 	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
    418 		ht40_intolerant_add(hapd->iface, sta);
    419 }
    420 
    421 
    422 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
    423 {
    424 	if (!sta->no_ht_set) {
    425 		sta->no_ht_set = 1;
    426 		hapd->iface->num_sta_no_ht++;
    427 	}
    428 	if (hapd->iconf->ieee80211n) {
    429 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
    430 			   "non-HT stations %d",
    431 			   __func__, MAC2STR(sta->addr),
    432 			   hapd->iface->num_sta_no_ht);
    433 	}
    434 }
    435 
    436 
    437 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
    438 {
    439 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
    440 		update_sta_ht(hapd, sta);
    441 	else
    442 		update_sta_no_ht(hapd, sta);
    443 
    444 	if (hostapd_ht_operation_update(hapd->iface) > 0)
    445 		ieee802_11_set_beacons(hapd->iface);
    446 }
    447 
    448 
    449 void hostapd_get_ht_capab(struct hostapd_data *hapd,
    450 			  struct ieee80211_ht_capabilities *ht_cap,
    451 			  struct ieee80211_ht_capabilities *neg_ht_cap)
    452 {
    453 	u16 cap;
    454 
    455 	if (ht_cap == NULL)
    456 		return;
    457 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
    458 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
    459 
    460 	/*
    461 	 * Mask out HT features we don't support, but don't overwrite
    462 	 * non-symmetric features like STBC and SMPS. Just because
    463 	 * we're not in dynamic SMPS mode the STA might still be.
    464 	 */
    465 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
    466 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
    467 
    468 	/*
    469 	 * STBC needs to be handled specially
    470 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
    471 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
    472 	 */
    473 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
    474 		cap &= ~HT_CAP_INFO_TX_STBC;
    475 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
    476 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
    477 
    478 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
    479 }
    480 
    481 
    482 void ap_ht2040_timeout(void *eloop_data, void *user_data)
    483 {
    484 	struct hostapd_iface *iface = eloop_data;
    485 
    486 	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
    487 
    488 	iface->conf->secondary_channel = iface->secondary_ch;
    489 	ieee802_11_set_beacons(iface);
    490 }
    491