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      1 /*
      2  * hostapd / Hardware feature query and different modes
      3  * Copyright 2002-2003, Instant802 Networks, Inc.
      4  * Copyright 2005-2006, Devicescape Software, Inc.
      5  * Copyright (c) 2008-2012, Jouni Malinen <j (at) w1.fi>
      6  *
      7  * This program is free software; you can redistribute it and/or modify
      8  * it under the terms of the GNU General Public License version 2 as
      9  * published by the Free Software Foundation.
     10  *
     11  * Alternatively, this software may be distributed under the terms of BSD
     12  * license.
     13  *
     14  * See README and COPYING for more details.
     15  */
     16 
     17 #include "utils/includes.h"
     18 
     19 #include "utils/common.h"
     20 #include "utils/eloop.h"
     21 #include "common/ieee802_11_defs.h"
     22 #include "common/ieee802_11_common.h"
     23 #include "drivers/driver.h"
     24 #include "hostapd.h"
     25 #include "ap_config.h"
     26 #include "ap_drv_ops.h"
     27 #include "hw_features.h"
     28 
     29 
     30 void hostapd_free_hw_features(struct hostapd_hw_modes *hw_features,
     31 			      size_t num_hw_features)
     32 {
     33 	size_t i;
     34 
     35 	if (hw_features == NULL)
     36 		return;
     37 
     38 	for (i = 0; i < num_hw_features; i++) {
     39 		os_free(hw_features[i].channels);
     40 		os_free(hw_features[i].rates);
     41 	}
     42 
     43 	os_free(hw_features);
     44 }
     45 
     46 
     47 int hostapd_get_hw_features(struct hostapd_iface *iface)
     48 {
     49 	struct hostapd_data *hapd = iface->bss[0];
     50 	int ret = 0, i, j;
     51 	u16 num_modes, flags;
     52 	struct hostapd_hw_modes *modes;
     53 
     54 	if (hostapd_drv_none(hapd))
     55 		return -1;
     56 	modes = hostapd_get_hw_feature_data(hapd, &num_modes, &flags);
     57 	if (modes == NULL) {
     58 		hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
     59 			       HOSTAPD_LEVEL_DEBUG,
     60 			       "Fetching hardware channel/rate support not "
     61 			       "supported.");
     62 		return -1;
     63 	}
     64 
     65 	iface->hw_flags = flags;
     66 
     67 	hostapd_free_hw_features(iface->hw_features, iface->num_hw_features);
     68 	iface->hw_features = modes;
     69 	iface->num_hw_features = num_modes;
     70 
     71 	for (i = 0; i < num_modes; i++) {
     72 		struct hostapd_hw_modes *feature = &modes[i];
     73 		/* set flag for channels we can use in current regulatory
     74 		 * domain */
     75 		for (j = 0; j < feature->num_channels; j++) {
     76 			/*
     77 			 * Disable all channels that are marked not to allow
     78 			 * IBSS operation or active scanning. In addition,
     79 			 * disable all channels that require radar detection,
     80 			 * since that (in addition to full DFS) is not yet
     81 			 * supported.
     82 			 */
     83 			if (feature->channels[j].flag &
     84 			    (HOSTAPD_CHAN_NO_IBSS |
     85 			     HOSTAPD_CHAN_PASSIVE_SCAN |
     86 			     HOSTAPD_CHAN_RADAR))
     87 				feature->channels[j].flag |=
     88 					HOSTAPD_CHAN_DISABLED;
     89 			if (feature->channels[j].flag & HOSTAPD_CHAN_DISABLED)
     90 				continue;
     91 			wpa_printf(MSG_MSGDUMP, "Allowed channel: mode=%d "
     92 				   "chan=%d freq=%d MHz max_tx_power=%d dBm",
     93 				   feature->mode,
     94 				   feature->channels[j].chan,
     95 				   feature->channels[j].freq,
     96 				   feature->channels[j].max_tx_power);
     97 		}
     98 	}
     99 
    100 	return ret;
    101 }
    102 
    103 
    104 int hostapd_prepare_rates(struct hostapd_iface *iface,
    105 			  struct hostapd_hw_modes *mode)
    106 {
    107 	int i, num_basic_rates = 0;
    108 	int basic_rates_a[] = { 60, 120, 240, -1 };
    109 	int basic_rates_b[] = { 10, 20, -1 };
    110 	int basic_rates_g[] = { 10, 20, 55, 110, -1 };
    111 	int *basic_rates;
    112 
    113 	if (iface->conf->basic_rates)
    114 		basic_rates = iface->conf->basic_rates;
    115 	else switch (mode->mode) {
    116 	case HOSTAPD_MODE_IEEE80211A:
    117 		basic_rates = basic_rates_a;
    118 		break;
    119 	case HOSTAPD_MODE_IEEE80211B:
    120 		basic_rates = basic_rates_b;
    121 		break;
    122 	case HOSTAPD_MODE_IEEE80211G:
    123 		basic_rates = basic_rates_g;
    124 		break;
    125 	default:
    126 		return -1;
    127 	}
    128 
    129 	i = 0;
    130 	while (basic_rates[i] >= 0)
    131 		i++;
    132 	if (i)
    133 		i++; /* -1 termination */
    134 	os_free(iface->basic_rates);
    135 	iface->basic_rates = os_malloc(i * sizeof(int));
    136 	if (iface->basic_rates)
    137 		os_memcpy(iface->basic_rates, basic_rates, i * sizeof(int));
    138 
    139 	os_free(iface->current_rates);
    140 	iface->num_rates = 0;
    141 
    142 	iface->current_rates =
    143 		os_calloc(mode->num_rates, sizeof(struct hostapd_rate_data));
    144 	if (!iface->current_rates) {
    145 		wpa_printf(MSG_ERROR, "Failed to allocate memory for rate "
    146 			   "table.");
    147 		return -1;
    148 	}
    149 
    150 	for (i = 0; i < mode->num_rates; i++) {
    151 		struct hostapd_rate_data *rate;
    152 
    153 		if (iface->conf->supported_rates &&
    154 		    !hostapd_rate_found(iface->conf->supported_rates,
    155 					mode->rates[i]))
    156 			continue;
    157 
    158 		rate = &iface->current_rates[iface->num_rates];
    159 		rate->rate = mode->rates[i];
    160 		if (hostapd_rate_found(basic_rates, rate->rate)) {
    161 			rate->flags |= HOSTAPD_RATE_BASIC;
    162 			num_basic_rates++;
    163 		}
    164 		wpa_printf(MSG_DEBUG, "RATE[%d] rate=%d flags=0x%x",
    165 			   iface->num_rates, rate->rate, rate->flags);
    166 		iface->num_rates++;
    167 	}
    168 
    169 	if ((iface->num_rates == 0 || num_basic_rates == 0) &&
    170 	    (!iface->conf->ieee80211n || !iface->conf->require_ht)) {
    171 		wpa_printf(MSG_ERROR, "No rates remaining in supported/basic "
    172 			   "rate sets (%d,%d).",
    173 			   iface->num_rates, num_basic_rates);
    174 		return -1;
    175 	}
    176 
    177 	return 0;
    178 }
    179 
    180 
    181 #ifdef CONFIG_IEEE80211N
    182 static int ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface *iface)
    183 {
    184 	int sec_chan, ok, j, first;
    185 	int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
    186 			  184, 192 };
    187 	size_t k;
    188 
    189 	if (!iface->conf->secondary_channel)
    190 		return 1; /* HT40 not used */
    191 
    192 	sec_chan = iface->conf->channel + iface->conf->secondary_channel * 4;
    193 	wpa_printf(MSG_DEBUG, "HT40: control channel: %d  "
    194 		   "secondary channel: %d",
    195 		   iface->conf->channel, sec_chan);
    196 
    197 	/* Verify that HT40 secondary channel is an allowed 20 MHz
    198 	 * channel */
    199 	ok = 0;
    200 	for (j = 0; j < iface->current_mode->num_channels; j++) {
    201 		struct hostapd_channel_data *chan =
    202 			&iface->current_mode->channels[j];
    203 		if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
    204 		    chan->chan == sec_chan) {
    205 			ok = 1;
    206 			break;
    207 		}
    208 	}
    209 	if (!ok) {
    210 		wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
    211 			   sec_chan);
    212 		return 0;
    213 	}
    214 
    215 	/*
    216 	 * Verify that HT40 primary,secondary channel pair is allowed per
    217 	 * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
    218 	 * 2.4 GHz rules allow all cases where the secondary channel fits into
    219 	 * the list of allowed channels (already checked above).
    220 	 */
    221 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
    222 		return 1;
    223 
    224 	if (iface->conf->secondary_channel > 0)
    225 		first = iface->conf->channel;
    226 	else
    227 		first = sec_chan;
    228 
    229 	ok = 0;
    230 	for (k = 0; k < sizeof(allowed) / sizeof(allowed[0]); k++) {
    231 		if (first == allowed[k]) {
    232 			ok = 1;
    233 			break;
    234 		}
    235 	}
    236 	if (!ok) {
    237 		wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
    238 			   iface->conf->channel,
    239 			   iface->conf->secondary_channel);
    240 		return 0;
    241 	}
    242 
    243 	return 1;
    244 }
    245 
    246 
    247 static void ieee80211n_switch_pri_sec(struct hostapd_iface *iface)
    248 {
    249 	if (iface->conf->secondary_channel > 0) {
    250 		iface->conf->channel += 4;
    251 		iface->conf->secondary_channel = -1;
    252 	} else {
    253 		iface->conf->channel -= 4;
    254 		iface->conf->secondary_channel = 1;
    255 	}
    256 }
    257 
    258 
    259 static void ieee80211n_get_pri_sec_chan(struct wpa_scan_res *bss,
    260 					int *pri_chan, int *sec_chan)
    261 {
    262 	struct ieee80211_ht_operation *oper;
    263 	struct ieee802_11_elems elems;
    264 
    265 	*pri_chan = *sec_chan = 0;
    266 
    267 	ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
    268 	if (elems.ht_operation &&
    269 	    elems.ht_operation_len >= sizeof(*oper)) {
    270 		oper = (struct ieee80211_ht_operation *) elems.ht_operation;
    271 		*pri_chan = oper->control_chan;
    272 		if (oper->ht_param & HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH) {
    273 			int sec = oper->ht_param &
    274 				HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
    275 			if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
    276 				*sec_chan = *pri_chan + 4;
    277 			else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
    278 				*sec_chan = *pri_chan - 4;
    279 		}
    280 	}
    281 }
    282 
    283 
    284 static int ieee80211n_check_40mhz_5g(struct hostapd_iface *iface,
    285 				     struct wpa_scan_results *scan_res)
    286 {
    287 	int pri_chan, sec_chan, pri_freq, sec_freq, pri_bss, sec_bss;
    288 	int bss_pri_chan, bss_sec_chan;
    289 	size_t i;
    290 	int match;
    291 
    292 	pri_chan = iface->conf->channel;
    293 	sec_chan = iface->conf->secondary_channel * 4;
    294 	pri_freq = hostapd_hw_get_freq(iface->bss[0], pri_chan);
    295 	if (iface->conf->secondary_channel > 0)
    296 		sec_freq = pri_freq + 20;
    297 	else
    298 		sec_freq = pri_freq - 20;
    299 
    300 	/*
    301 	 * Switch PRI/SEC channels if Beacons were detected on selected SEC
    302 	 * channel, but not on selected PRI channel.
    303 	 */
    304 	pri_bss = sec_bss = 0;
    305 	for (i = 0; i < scan_res->num; i++) {
    306 		struct wpa_scan_res *bss = scan_res->res[i];
    307 		if (bss->freq == pri_freq)
    308 			pri_bss++;
    309 		else if (bss->freq == sec_freq)
    310 			sec_bss++;
    311 	}
    312 	if (sec_bss && !pri_bss) {
    313 		wpa_printf(MSG_INFO, "Switch own primary and secondary "
    314 			   "channel to get secondary channel with no Beacons "
    315 			   "from other BSSes");
    316 		ieee80211n_switch_pri_sec(iface);
    317 	}
    318 
    319 	/*
    320 	 * Match PRI/SEC channel with any existing HT40 BSS on the same
    321 	 * channels that we are about to use (if already mixed order in
    322 	 * existing BSSes, use own preference).
    323 	 */
    324 	match = 0;
    325 	for (i = 0; i < scan_res->num; i++) {
    326 		struct wpa_scan_res *bss = scan_res->res[i];
    327 		ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
    328 		if (pri_chan == bss_pri_chan &&
    329 		    sec_chan == bss_sec_chan) {
    330 			match = 1;
    331 			break;
    332 		}
    333 	}
    334 	if (!match) {
    335 		for (i = 0; i < scan_res->num; i++) {
    336 			struct wpa_scan_res *bss = scan_res->res[i];
    337 			ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan,
    338 						    &bss_sec_chan);
    339 			if (pri_chan == bss_sec_chan &&
    340 			    sec_chan == bss_pri_chan) {
    341 				wpa_printf(MSG_INFO, "Switch own primary and "
    342 					   "secondary channel due to BSS "
    343 					   "overlap with " MACSTR,
    344 					   MAC2STR(bss->bssid));
    345 				ieee80211n_switch_pri_sec(iface);
    346 				break;
    347 			}
    348 		}
    349 	}
    350 
    351 	return 1;
    352 }
    353 
    354 
    355 static int ieee80211n_check_40mhz_2g4(struct hostapd_iface *iface,
    356 				      struct wpa_scan_results *scan_res)
    357 {
    358 	int pri_freq, sec_freq;
    359 	int affected_start, affected_end;
    360 	size_t i;
    361 
    362 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
    363 	if (iface->conf->secondary_channel > 0)
    364 		sec_freq = pri_freq + 20;
    365 	else
    366 		sec_freq = pri_freq - 20;
    367 	affected_start = (pri_freq + sec_freq) / 2 - 25;
    368 	affected_end = (pri_freq + sec_freq) / 2 + 25;
    369 	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
    370 		   affected_start, affected_end);
    371 	for (i = 0; i < scan_res->num; i++) {
    372 		struct wpa_scan_res *bss = scan_res->res[i];
    373 		int pri = bss->freq;
    374 		int sec = pri;
    375 		int sec_chan, pri_chan;
    376 
    377 		ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
    378 
    379 		if (sec_chan) {
    380 			if (sec_chan < pri_chan)
    381 				sec = pri - 20;
    382 			else
    383 				sec = pri + 20;
    384 		}
    385 
    386 		if ((pri < affected_start || pri > affected_end) &&
    387 		    (sec < affected_start || sec > affected_end))
    388 			continue; /* not within affected channel range */
    389 
    390 		wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
    391 			   " freq=%d pri=%d sec=%d",
    392 			   MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
    393 
    394 		if (sec_chan) {
    395 			if (pri_freq != pri || sec_freq != sec) {
    396 				wpa_printf(MSG_DEBUG, "40 MHz pri/sec "
    397 					   "mismatch with BSS " MACSTR
    398 					   " <%d,%d> (chan=%d%c) vs. <%d,%d>",
    399 					   MAC2STR(bss->bssid),
    400 					   pri, sec, pri_chan,
    401 					   sec > pri ? '+' : '-',
    402 					   pri_freq, sec_freq);
    403 				return 0;
    404 			}
    405 		}
    406 
    407 		/* TODO: 40 MHz intolerant */
    408 	}
    409 
    410 	return 1;
    411 }
    412 
    413 
    414 static void ieee80211n_check_scan(struct hostapd_iface *iface)
    415 {
    416 	struct wpa_scan_results *scan_res;
    417 	int oper40;
    418 	int res;
    419 
    420 	/* Check list of neighboring BSSes (from scan) to see whether 40 MHz is
    421 	 * allowed per IEEE Std 802.11-2012, 10.15.3.2 */
    422 
    423 	iface->scan_cb = NULL;
    424 
    425 	scan_res = hostapd_driver_get_scan_results(iface->bss[0]);
    426 	if (scan_res == NULL) {
    427 		hostapd_setup_interface_complete(iface, 1);
    428 		return;
    429 	}
    430 
    431 	if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A)
    432 		oper40 = ieee80211n_check_40mhz_5g(iface, scan_res);
    433 	else
    434 		oper40 = ieee80211n_check_40mhz_2g4(iface, scan_res);
    435 	wpa_scan_results_free(scan_res);
    436 
    437 	if (!oper40) {
    438 		wpa_printf(MSG_INFO, "20/40 MHz operation not permitted on "
    439 			   "channel pri=%d sec=%d based on overlapping BSSes",
    440 			   iface->conf->channel,
    441 			   iface->conf->channel +
    442 			   iface->conf->secondary_channel * 4);
    443 		iface->conf->secondary_channel = 0;
    444 		iface->conf->ht_capab &= ~HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET;
    445 	}
    446 
    447 	res = ieee80211n_allowed_ht40_channel_pair(iface);
    448 	hostapd_setup_interface_complete(iface, !res);
    449 }
    450 
    451 
    452 static void ieee80211n_scan_channels_2g4(struct hostapd_iface *iface,
    453 					 struct wpa_driver_scan_params *params)
    454 {
    455 	/* Scan only the affected frequency range */
    456 	int pri_freq, sec_freq;
    457 	int affected_start, affected_end;
    458 	int i, pos;
    459 	struct hostapd_hw_modes *mode;
    460 
    461 	if (iface->current_mode == NULL)
    462 		return;
    463 
    464 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
    465 	if (iface->conf->secondary_channel > 0)
    466 		sec_freq = pri_freq + 20;
    467 	else
    468 		sec_freq = pri_freq - 20;
    469 	affected_start = (pri_freq + sec_freq) / 2 - 25;
    470 	affected_end = (pri_freq + sec_freq) / 2 + 25;
    471 	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
    472 		   affected_start, affected_end);
    473 
    474 	mode = iface->current_mode;
    475 	params->freqs = os_calloc(mode->num_channels + 1, sizeof(int));
    476 	if (params->freqs == NULL)
    477 		return;
    478 	pos = 0;
    479 
    480 	for (i = 0; i < mode->num_channels; i++) {
    481 		struct hostapd_channel_data *chan = &mode->channels[i];
    482 		if (chan->flag & HOSTAPD_CHAN_DISABLED)
    483 			continue;
    484 		if (chan->freq < affected_start ||
    485 		    chan->freq > affected_end)
    486 			continue;
    487 		params->freqs[pos++] = chan->freq;
    488 	}
    489 }
    490 
    491 
    492 static int ieee80211n_check_40mhz(struct hostapd_iface *iface)
    493 {
    494 	struct wpa_driver_scan_params params;
    495 
    496 	if (!iface->conf->secondary_channel)
    497 		return 0; /* HT40 not used */
    498 
    499 	wpa_printf(MSG_DEBUG, "Scan for neighboring BSSes prior to enabling "
    500 		   "40 MHz channel");
    501 	os_memset(&params, 0, sizeof(params));
    502 	if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211G)
    503 		ieee80211n_scan_channels_2g4(iface, &params);
    504 	if (hostapd_driver_scan(iface->bss[0], &params) < 0) {
    505 		wpa_printf(MSG_ERROR, "Failed to request a scan of "
    506 			   "neighboring BSSes");
    507 		os_free(params.freqs);
    508 		return -1;
    509 	}
    510 	os_free(params.freqs);
    511 
    512 	iface->scan_cb = ieee80211n_check_scan;
    513 	return 1;
    514 }
    515 
    516 
    517 static int ieee80211n_supported_ht_capab(struct hostapd_iface *iface)
    518 {
    519 	u16 hw = iface->current_mode->ht_capab;
    520 	u16 conf = iface->conf->ht_capab;
    521 
    522 	if ((conf & HT_CAP_INFO_LDPC_CODING_CAP) &&
    523 	    !(hw & HT_CAP_INFO_LDPC_CODING_CAP)) {
    524 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    525 			   "HT capability [LDPC]");
    526 		return 0;
    527 	}
    528 
    529 	if ((conf & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
    530 	    !(hw & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
    531 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    532 			   "HT capability [HT40*]");
    533 		return 0;
    534 	}
    535 
    536 	if ((conf & HT_CAP_INFO_SMPS_MASK) != (hw & HT_CAP_INFO_SMPS_MASK) &&
    537 	    (conf & HT_CAP_INFO_SMPS_MASK) != HT_CAP_INFO_SMPS_DISABLED) {
    538 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    539 			   "HT capability [SMPS-*]");
    540 		return 0;
    541 	}
    542 
    543 	if ((conf & HT_CAP_INFO_GREEN_FIELD) &&
    544 	    !(hw & HT_CAP_INFO_GREEN_FIELD)) {
    545 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    546 			   "HT capability [GF]");
    547 		return 0;
    548 	}
    549 
    550 	if ((conf & HT_CAP_INFO_SHORT_GI20MHZ) &&
    551 	    !(hw & HT_CAP_INFO_SHORT_GI20MHZ)) {
    552 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    553 			   "HT capability [SHORT-GI-20]");
    554 		return 0;
    555 	}
    556 
    557 	if ((conf & HT_CAP_INFO_SHORT_GI40MHZ) &&
    558 	    !(hw & HT_CAP_INFO_SHORT_GI40MHZ)) {
    559 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    560 			   "HT capability [SHORT-GI-40]");
    561 		return 0;
    562 	}
    563 
    564 	if ((conf & HT_CAP_INFO_TX_STBC) && !(hw & HT_CAP_INFO_TX_STBC)) {
    565 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    566 			   "HT capability [TX-STBC]");
    567 		return 0;
    568 	}
    569 
    570 	if ((conf & HT_CAP_INFO_RX_STBC_MASK) >
    571 	    (hw & HT_CAP_INFO_RX_STBC_MASK)) {
    572 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    573 			   "HT capability [RX-STBC*]");
    574 		return 0;
    575 	}
    576 
    577 	if ((conf & HT_CAP_INFO_DELAYED_BA) &&
    578 	    !(hw & HT_CAP_INFO_DELAYED_BA)) {
    579 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    580 			   "HT capability [DELAYED-BA]");
    581 		return 0;
    582 	}
    583 
    584 	if ((conf & HT_CAP_INFO_MAX_AMSDU_SIZE) &&
    585 	    !(hw & HT_CAP_INFO_MAX_AMSDU_SIZE)) {
    586 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    587 			   "HT capability [MAX-AMSDU-7935]");
    588 		return 0;
    589 	}
    590 
    591 	if ((conf & HT_CAP_INFO_DSSS_CCK40MHZ) &&
    592 	    !(hw & HT_CAP_INFO_DSSS_CCK40MHZ)) {
    593 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    594 			   "HT capability [DSSS_CCK-40]");
    595 		return 0;
    596 	}
    597 
    598 	if ((conf & HT_CAP_INFO_PSMP_SUPP) && !(hw & HT_CAP_INFO_PSMP_SUPP)) {
    599 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    600 			   "HT capability [PSMP]");
    601 		return 0;
    602 	}
    603 
    604 	if ((conf & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT) &&
    605 	    !(hw & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT)) {
    606 		wpa_printf(MSG_ERROR, "Driver does not support configured "
    607 			   "HT capability [LSIG-TXOP-PROT]");
    608 		return 0;
    609 	}
    610 
    611 	return 1;
    612 }
    613 
    614 #endif /* CONFIG_IEEE80211N */
    615 
    616 
    617 int hostapd_check_ht_capab(struct hostapd_iface *iface)
    618 {
    619 #ifdef CONFIG_IEEE80211N
    620 	int ret;
    621 	if (!iface->conf->ieee80211n)
    622 		return 0;
    623 	if (!ieee80211n_supported_ht_capab(iface))
    624 		return -1;
    625 	ret = ieee80211n_check_40mhz(iface);
    626 	if (ret)
    627 		return ret;
    628 	if (!ieee80211n_allowed_ht40_channel_pair(iface))
    629 		return -1;
    630 #endif /* CONFIG_IEEE80211N */
    631 
    632 	return 0;
    633 }
    634 
    635 
    636 /**
    637  * hostapd_select_hw_mode - Select the hardware mode
    638  * @iface: Pointer to interface data.
    639  * Returns: 0 on success, < 0 on failure
    640  *
    641  * Sets up the hardware mode, channel, rates, and passive scanning
    642  * based on the configuration.
    643  */
    644 int hostapd_select_hw_mode(struct hostapd_iface *iface)
    645 {
    646 	int i, j, ok;
    647 
    648 	if (iface->num_hw_features < 1)
    649 		return -1;
    650 
    651 	iface->current_mode = NULL;
    652 	for (i = 0; i < iface->num_hw_features; i++) {
    653 		struct hostapd_hw_modes *mode = &iface->hw_features[i];
    654 		if (mode->mode == iface->conf->hw_mode) {
    655 			iface->current_mode = mode;
    656 			break;
    657 		}
    658 	}
    659 
    660 	if (iface->current_mode == NULL) {
    661 		wpa_printf(MSG_ERROR, "Hardware does not support configured "
    662 			   "mode");
    663 		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
    664 			       HOSTAPD_LEVEL_WARNING,
    665 			       "Hardware does not support configured mode "
    666 			       "(%d) (hw_mode in hostapd.conf)",
    667 			       (int) iface->conf->hw_mode);
    668 		return -2;
    669 	}
    670 
    671 	ok = 0;
    672 	for (j = 0; j < iface->current_mode->num_channels; j++) {
    673 		struct hostapd_channel_data *chan =
    674 			&iface->current_mode->channels[j];
    675 		if (chan->chan == iface->conf->channel) {
    676 			if (chan->flag & HOSTAPD_CHAN_DISABLED) {
    677 				wpa_printf(MSG_ERROR,
    678 					   "channel [%i] (%i) is disabled for "
    679 					   "use in AP mode, flags: 0x%x%s%s%s",
    680 					   j, chan->chan, chan->flag,
    681 					   chan->flag & HOSTAPD_CHAN_NO_IBSS ?
    682 					   " NO-IBSS" : "",
    683 					   chan->flag &
    684 					   HOSTAPD_CHAN_PASSIVE_SCAN ?
    685 					   " PASSIVE-SCAN" : "",
    686 					   chan->flag & HOSTAPD_CHAN_RADAR ?
    687 					   " RADAR" : "");
    688 			} else {
    689 				ok = 1;
    690 				break;
    691 			}
    692 		}
    693 	}
    694 	if (ok && iface->conf->secondary_channel) {
    695 		int sec_ok = 0;
    696 		int sec_chan = iface->conf->channel +
    697 			iface->conf->secondary_channel * 4;
    698 		for (j = 0; j < iface->current_mode->num_channels; j++) {
    699 			struct hostapd_channel_data *chan =
    700 				&iface->current_mode->channels[j];
    701 			if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
    702 			    (chan->chan == sec_chan)) {
    703 				sec_ok = 1;
    704 				break;
    705 			}
    706 		}
    707 		if (!sec_ok) {
    708 			hostapd_logger(iface->bss[0], NULL,
    709 				       HOSTAPD_MODULE_IEEE80211,
    710 				       HOSTAPD_LEVEL_WARNING,
    711 				       "Configured HT40 secondary channel "
    712 				       "(%d) not found from the channel list "
    713 				       "of current mode (%d) %s",
    714 				       sec_chan, iface->current_mode->mode,
    715 				       hostapd_hw_mode_txt(
    716 					       iface->current_mode->mode));
    717 			ok = 0;
    718 		}
    719 	}
    720 	if (iface->conf->channel == 0) {
    721 		/* TODO: could request a scan of neighboring BSSes and select
    722 		 * the channel automatically */
    723 		wpa_printf(MSG_ERROR, "Channel not configured "
    724 			   "(hw_mode/channel in hostapd.conf)");
    725 		return -3;
    726 	}
    727 	if (ok == 0 && iface->conf->channel != 0) {
    728 		hostapd_logger(iface->bss[0], NULL,
    729 			       HOSTAPD_MODULE_IEEE80211,
    730 			       HOSTAPD_LEVEL_WARNING,
    731 			       "Configured channel (%d) not found from the "
    732 			       "channel list of current mode (%d) %s",
    733 			       iface->conf->channel,
    734 			       iface->current_mode->mode,
    735 			       hostapd_hw_mode_txt(iface->current_mode->mode));
    736 		iface->current_mode = NULL;
    737 	}
    738 
    739 	if (iface->current_mode == NULL) {
    740 		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
    741 			       HOSTAPD_LEVEL_WARNING,
    742 			       "Hardware does not support configured channel");
    743 		return -4;
    744 	}
    745 
    746 	return 0;
    747 }
    748 
    749 
    750 const char * hostapd_hw_mode_txt(int mode)
    751 {
    752 	switch (mode) {
    753 	case HOSTAPD_MODE_IEEE80211A:
    754 		return "IEEE 802.11a";
    755 	case HOSTAPD_MODE_IEEE80211B:
    756 		return "IEEE 802.11b";
    757 	case HOSTAPD_MODE_IEEE80211G:
    758 		return "IEEE 802.11g";
    759 	default:
    760 		return "UNKNOWN";
    761 	}
    762 }
    763 
    764 
    765 int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
    766 {
    767 	int i;
    768 
    769 	if (!hapd->iface->current_mode)
    770 		return 0;
    771 
    772 	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
    773 		struct hostapd_channel_data *ch =
    774 			&hapd->iface->current_mode->channels[i];
    775 		if (ch->chan == chan)
    776 			return ch->freq;
    777 	}
    778 
    779 	return 0;
    780 }
    781 
    782 
    783 int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
    784 {
    785 	int i;
    786 
    787 	if (!hapd->iface->current_mode)
    788 		return 0;
    789 
    790 	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
    791 		struct hostapd_channel_data *ch =
    792 			&hapd->iface->current_mode->channels[i];
    793 		if (ch->freq == freq)
    794 			return ch->chan;
    795 	}
    796 
    797 	return 0;
    798 }
    799