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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 u8 * hostapd_eid_secondary_channel(struct hostapd_data *hapd, u8 *eid)
    112 {
    113 	u8 sec_ch;
    114 
    115 	if (!hapd->cs_freq_params.channel ||
    116 	    !hapd->cs_freq_params.sec_channel_offset)
    117 		return eid;
    118 
    119 	if (hapd->cs_freq_params.sec_channel_offset == -1)
    120 		sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW;
    121 	else if (hapd->cs_freq_params.sec_channel_offset == 1)
    122 		sec_ch = HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE;
    123 	else
    124 		return eid;
    125 
    126 	*eid++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET;
    127 	*eid++ = 1;
    128 	*eid++ = sec_ch;
    129 
    130 	return eid;
    131 }
    132 
    133 
    134 /*
    135 op_mode
    136 Set to 0 (HT pure) under the followign conditions
    137 	- all STAs in the BSS are 20/40 MHz HT in 20/40 MHz BSS or
    138 	- all STAs in the BSS are 20 MHz HT in 20 MHz BSS
    139 Set to 1 (HT non-member protection) if there may be non-HT STAs
    140 	in both the primary and the secondary channel
    141 Set to 2 if only HT STAs are associated in BSS,
    142 	however and at least one 20 MHz HT STA is associated
    143 Set to 3 (HT mixed mode) when one or more non-HT STAs are associated
    144 */
    145 int hostapd_ht_operation_update(struct hostapd_iface *iface)
    146 {
    147 	u16 cur_op_mode, new_op_mode;
    148 	int op_mode_changes = 0;
    149 
    150 	if (!iface->conf->ieee80211n || iface->conf->ht_op_mode_fixed)
    151 		return 0;
    152 
    153 	wpa_printf(MSG_DEBUG, "%s current operation mode=0x%X",
    154 		   __func__, iface->ht_op_mode);
    155 
    156 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT)
    157 	    && iface->num_sta_ht_no_gf) {
    158 		iface->ht_op_mode |= HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
    159 		op_mode_changes++;
    160 	} else if ((iface->ht_op_mode &
    161 		    HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT) &&
    162 		   iface->num_sta_ht_no_gf == 0) {
    163 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_NON_GF_HT_STAS_PRESENT;
    164 		op_mode_changes++;
    165 	}
    166 
    167 	if (!(iface->ht_op_mode & HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
    168 	    (iface->num_sta_no_ht || iface->olbc_ht)) {
    169 		iface->ht_op_mode |= HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
    170 		op_mode_changes++;
    171 	} else if ((iface->ht_op_mode &
    172 		    HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT) &&
    173 		   (iface->num_sta_no_ht == 0 && !iface->olbc_ht)) {
    174 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_OBSS_NON_HT_STAS_PRESENT;
    175 		op_mode_changes++;
    176 	}
    177 
    178 	if (iface->num_sta_no_ht)
    179 		new_op_mode = HT_PROT_NON_HT_MIXED;
    180 	else if (iface->conf->secondary_channel && iface->num_sta_ht_20mhz)
    181 		new_op_mode = HT_PROT_20MHZ_PROTECTION;
    182 	else if (iface->olbc_ht)
    183 		new_op_mode = HT_PROT_NONMEMBER_PROTECTION;
    184 	else
    185 		new_op_mode = HT_PROT_NO_PROTECTION;
    186 
    187 	cur_op_mode = iface->ht_op_mode & HT_OPER_OP_MODE_HT_PROT_MASK;
    188 	if (cur_op_mode != new_op_mode) {
    189 		iface->ht_op_mode &= ~HT_OPER_OP_MODE_HT_PROT_MASK;
    190 		iface->ht_op_mode |= new_op_mode;
    191 		op_mode_changes++;
    192 	}
    193 
    194 	wpa_printf(MSG_DEBUG, "%s new operation mode=0x%X changes=%d",
    195 		   __func__, iface->ht_op_mode, op_mode_changes);
    196 
    197 	return op_mode_changes;
    198 }
    199 
    200 
    201 static int is_40_allowed(struct hostapd_iface *iface, int channel)
    202 {
    203 	int pri_freq, sec_freq;
    204 	int affected_start, affected_end;
    205 	int pri = 2407 + 5 * channel;
    206 
    207 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
    208 		return 1;
    209 
    210 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
    211 
    212 	if (iface->conf->secondary_channel > 0)
    213 		sec_freq = pri_freq + 20;
    214 	else
    215 		sec_freq = pri_freq - 20;
    216 
    217 	affected_start = (pri_freq + sec_freq) / 2 - 25;
    218 	affected_end = (pri_freq + sec_freq) / 2 + 25;
    219 	if ((pri < affected_start || pri > affected_end))
    220 		return 1; /* not within affected channel range */
    221 
    222 	wpa_printf(MSG_ERROR, "40 MHz affected channel range: [%d,%d] MHz",
    223 		   affected_start, affected_end);
    224 	wpa_printf(MSG_ERROR, "Neighboring BSS: freq=%d", pri);
    225 	return 0;
    226 }
    227 
    228 
    229 void hostapd_2040_coex_action(struct hostapd_data *hapd,
    230 			      const struct ieee80211_mgmt *mgmt, size_t len)
    231 {
    232 	struct hostapd_iface *iface = hapd->iface;
    233 	struct ieee80211_2040_bss_coex_ie *bc_ie;
    234 	struct ieee80211_2040_intol_chan_report *ic_report;
    235 	int is_ht40_allowed = 1;
    236 	int i;
    237 	const u8 *start = (const u8 *) mgmt;
    238 	const u8 *data = start + IEEE80211_HDRLEN + 2;
    239 
    240 	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
    241 		       HOSTAPD_LEVEL_DEBUG, "hostapd_public_action - action=%d",
    242 		       mgmt->u.action.u.public_action.action);
    243 
    244 	if (!(iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET))
    245 		return;
    246 
    247 	if (len < IEEE80211_HDRLEN + 2 + sizeof(*bc_ie))
    248 		return;
    249 
    250 	bc_ie = (struct ieee80211_2040_bss_coex_ie *) data;
    251 	if (bc_ie->element_id != WLAN_EID_20_40_BSS_COEXISTENCE ||
    252 	    bc_ie->length < 1) {
    253 		wpa_printf(MSG_DEBUG, "Unexpected IE (%u,%u) in coex report",
    254 			   bc_ie->element_id, bc_ie->length);
    255 		return;
    256 	}
    257 	if (len < IEEE80211_HDRLEN + 2 + 2 + bc_ie->length)
    258 		return;
    259 	data += 2 + bc_ie->length;
    260 
    261 	wpa_printf(MSG_DEBUG, "20/40 BSS Coexistence Information field: 0x%x",
    262 		   bc_ie->coex_param);
    263 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_20MHZ_WIDTH_REQ) {
    264 		hostapd_logger(hapd, mgmt->sa,
    265 			       HOSTAPD_MODULE_IEEE80211,
    266 			       HOSTAPD_LEVEL_DEBUG,
    267 			       "20 MHz BSS width request bit is set in BSS coexistence information field");
    268 		is_ht40_allowed = 0;
    269 	}
    270 
    271 	if (bc_ie->coex_param & WLAN_20_40_BSS_COEX_40MHZ_INTOL) {
    272 		hostapd_logger(hapd, mgmt->sa,
    273 			       HOSTAPD_MODULE_IEEE80211,
    274 			       HOSTAPD_LEVEL_DEBUG,
    275 			       "40 MHz intolerant bit is set in BSS coexistence information field");
    276 		is_ht40_allowed = 0;
    277 	}
    278 
    279 	if (start + len - data >= 3 &&
    280 	    data[0] == WLAN_EID_20_40_BSS_INTOLERANT && data[1] >= 1) {
    281 		u8 ielen = data[1];
    282 
    283 		if (ielen > start + len - data - 2)
    284 			return;
    285 		ic_report = (struct ieee80211_2040_intol_chan_report *) data;
    286 		wpa_printf(MSG_DEBUG,
    287 			   "20/40 BSS Intolerant Channel Report: Operating Class %u",
    288 			   ic_report->op_class);
    289 
    290 		/* Go through the channel report to find any BSS there in the
    291 		 * affected channel range */
    292 		for (i = 0; i < ielen - 1; i++) {
    293 			u8 chan = ic_report->variable[i];
    294 
    295 			if (is_40_allowed(iface, chan))
    296 				continue;
    297 			hostapd_logger(hapd, mgmt->sa,
    298 				       HOSTAPD_MODULE_IEEE80211,
    299 				       HOSTAPD_LEVEL_DEBUG,
    300 				       "20_40_INTOLERANT channel %d reported",
    301 				       chan);
    302 			is_ht40_allowed = 0;
    303 		}
    304 	}
    305 	wpa_printf(MSG_DEBUG, "is_ht40_allowed=%d num_sta_ht40_intolerant=%d",
    306 		   is_ht40_allowed, iface->num_sta_ht40_intolerant);
    307 
    308 	if (!is_ht40_allowed &&
    309 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    310 		if (iface->conf->secondary_channel) {
    311 			hostapd_logger(hapd, mgmt->sa,
    312 				       HOSTAPD_MODULE_IEEE80211,
    313 				       HOSTAPD_LEVEL_INFO,
    314 				       "Switching to 20 MHz operation");
    315 			iface->conf->secondary_channel = 0;
    316 			ieee802_11_set_beacons(iface);
    317 		}
    318 		if (!iface->num_sta_ht40_intolerant &&
    319 		    iface->conf->obss_interval) {
    320 			unsigned int delay_time;
    321 			delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
    322 				iface->conf->obss_interval;
    323 			eloop_cancel_timeout(ap_ht2040_timeout, hapd->iface,
    324 					     NULL);
    325 			eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
    326 					       hapd->iface, NULL);
    327 			wpa_printf(MSG_DEBUG,
    328 				   "Reschedule HT 20/40 timeout to occur in %u seconds",
    329 				   delay_time);
    330 		}
    331 	}
    332 }
    333 
    334 
    335 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
    336 		      const u8 *ht_capab)
    337 {
    338 	/*
    339 	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
    340 	 * that did not specify a valid WMM IE in the (Re)Association Request
    341 	 * frame.
    342 	 */
    343 	if (!ht_capab ||
    344 	    !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
    345 		sta->flags &= ~WLAN_STA_HT;
    346 		os_free(sta->ht_capabilities);
    347 		sta->ht_capabilities = NULL;
    348 		return WLAN_STATUS_SUCCESS;
    349 	}
    350 
    351 	if (sta->ht_capabilities == NULL) {
    352 		sta->ht_capabilities =
    353 			os_zalloc(sizeof(struct ieee80211_ht_capabilities));
    354 		if (sta->ht_capabilities == NULL)
    355 			return WLAN_STATUS_UNSPECIFIED_FAILURE;
    356 	}
    357 
    358 	sta->flags |= WLAN_STA_HT;
    359 	os_memcpy(sta->ht_capabilities, ht_capab,
    360 		  sizeof(struct ieee80211_ht_capabilities));
    361 
    362 	return WLAN_STATUS_SUCCESS;
    363 }
    364 
    365 
    366 void ht40_intolerant_add(struct hostapd_iface *iface, struct sta_info *sta)
    367 {
    368 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
    369 		return;
    370 
    371 	wpa_printf(MSG_INFO, "HT: Forty MHz Intolerant is set by STA " MACSTR
    372 		   " in Association Request", MAC2STR(sta->addr));
    373 
    374 	if (sta->ht40_intolerant_set)
    375 		return;
    376 
    377 	sta->ht40_intolerant_set = 1;
    378 	iface->num_sta_ht40_intolerant++;
    379 	eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
    380 
    381 	if (iface->conf->secondary_channel &&
    382 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    383 		iface->conf->secondary_channel = 0;
    384 		ieee802_11_set_beacons(iface);
    385 	}
    386 }
    387 
    388 
    389 void ht40_intolerant_remove(struct hostapd_iface *iface, struct sta_info *sta)
    390 {
    391 	if (!sta->ht40_intolerant_set)
    392 		return;
    393 
    394 	sta->ht40_intolerant_set = 0;
    395 	iface->num_sta_ht40_intolerant--;
    396 
    397 	if (iface->num_sta_ht40_intolerant == 0 &&
    398 	    (iface->conf->ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
    399 	    (iface->drv_flags & WPA_DRIVER_FLAGS_HT_2040_COEX)) {
    400 		unsigned int delay_time = OVERLAPPING_BSS_TRANS_DELAY_FACTOR *
    401 			iface->conf->obss_interval;
    402 		wpa_printf(MSG_DEBUG,
    403 			   "HT: Start 20->40 MHz transition timer (%d seconds)",
    404 			   delay_time);
    405 		eloop_cancel_timeout(ap_ht2040_timeout, iface, NULL);
    406 		eloop_register_timeout(delay_time, 0, ap_ht2040_timeout,
    407 				       iface, NULL);
    408 	}
    409 }
    410 
    411 
    412 static void update_sta_ht(struct hostapd_data *hapd, struct sta_info *sta)
    413 {
    414 	u16 ht_capab;
    415 
    416 	ht_capab = le_to_host16(sta->ht_capabilities->ht_capabilities_info);
    417 	wpa_printf(MSG_DEBUG, "HT: STA " MACSTR " HT Capabilities Info: "
    418 		   "0x%04x", MAC2STR(sta->addr), ht_capab);
    419 	if ((ht_capab & HT_CAP_INFO_GREEN_FIELD) == 0) {
    420 		if (!sta->no_ht_gf_set) {
    421 			sta->no_ht_gf_set = 1;
    422 			hapd->iface->num_sta_ht_no_gf++;
    423 		}
    424 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no greenfield, num "
    425 			   "of non-gf stations %d",
    426 			   __func__, MAC2STR(sta->addr),
    427 			   hapd->iface->num_sta_ht_no_gf);
    428 	}
    429 	if ((ht_capab & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) == 0) {
    430 		if (!sta->ht_20mhz_set) {
    431 			sta->ht_20mhz_set = 1;
    432 			hapd->iface->num_sta_ht_20mhz++;
    433 		}
    434 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - 20 MHz HT, num of "
    435 			   "20MHz HT STAs %d",
    436 			   __func__, MAC2STR(sta->addr),
    437 			   hapd->iface->num_sta_ht_20mhz);
    438 	}
    439 
    440 	if (ht_capab & HT_CAP_INFO_40MHZ_INTOLERANT)
    441 		ht40_intolerant_add(hapd->iface, sta);
    442 }
    443 
    444 
    445 static void update_sta_no_ht(struct hostapd_data *hapd, struct sta_info *sta)
    446 {
    447 	if (!sta->no_ht_set) {
    448 		sta->no_ht_set = 1;
    449 		hapd->iface->num_sta_no_ht++;
    450 	}
    451 	if (hapd->iconf->ieee80211n) {
    452 		wpa_printf(MSG_DEBUG, "%s STA " MACSTR " - no HT, num of "
    453 			   "non-HT stations %d",
    454 			   __func__, MAC2STR(sta->addr),
    455 			   hapd->iface->num_sta_no_ht);
    456 	}
    457 }
    458 
    459 
    460 void update_ht_state(struct hostapd_data *hapd, struct sta_info *sta)
    461 {
    462 	if ((sta->flags & WLAN_STA_HT) && sta->ht_capabilities)
    463 		update_sta_ht(hapd, sta);
    464 	else
    465 		update_sta_no_ht(hapd, sta);
    466 
    467 	if (hostapd_ht_operation_update(hapd->iface) > 0)
    468 		ieee802_11_set_beacons(hapd->iface);
    469 }
    470 
    471 
    472 void hostapd_get_ht_capab(struct hostapd_data *hapd,
    473 			  struct ieee80211_ht_capabilities *ht_cap,
    474 			  struct ieee80211_ht_capabilities *neg_ht_cap)
    475 {
    476 	u16 cap;
    477 
    478 	if (ht_cap == NULL)
    479 		return;
    480 	os_memcpy(neg_ht_cap, ht_cap, sizeof(*neg_ht_cap));
    481 	cap = le_to_host16(neg_ht_cap->ht_capabilities_info);
    482 
    483 	/*
    484 	 * Mask out HT features we don't support, but don't overwrite
    485 	 * non-symmetric features like STBC and SMPS. Just because
    486 	 * we're not in dynamic SMPS mode the STA might still be.
    487 	 */
    488 	cap &= (hapd->iconf->ht_capab | HT_CAP_INFO_RX_STBC_MASK |
    489 		HT_CAP_INFO_TX_STBC | HT_CAP_INFO_SMPS_MASK);
    490 
    491 	/*
    492 	 * STBC needs to be handled specially
    493 	 * if we don't support RX STBC, mask out TX STBC in the STA's HT caps
    494 	 * if we don't support TX STBC, mask out RX STBC in the STA's HT caps
    495 	 */
    496 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_RX_STBC_MASK))
    497 		cap &= ~HT_CAP_INFO_TX_STBC;
    498 	if (!(hapd->iconf->ht_capab & HT_CAP_INFO_TX_STBC))
    499 		cap &= ~HT_CAP_INFO_RX_STBC_MASK;
    500 
    501 	neg_ht_cap->ht_capabilities_info = host_to_le16(cap);
    502 }
    503 
    504 
    505 void ap_ht2040_timeout(void *eloop_data, void *user_data)
    506 {
    507 	struct hostapd_iface *iface = eloop_data;
    508 
    509 	wpa_printf(MSG_INFO, "Switching to 40 MHz operation");
    510 
    511 	iface->conf->secondary_channel = iface->secondary_ch;
    512 	ieee802_11_set_beacons(iface);
    513 }
    514