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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) 2008-2009, Jouni Malinen <j@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 
hostapd_free_hw_features(struct hostapd_hw_modes * hw_features,size_t num_hw_features)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 
hostapd_get_hw_features(struct hostapd_iface * iface)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 
hostapd_prepare_rates(struct hostapd_data * hapd,struct hostapd_hw_modes * mode)104 int hostapd_prepare_rates(struct hostapd_data *hapd,
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 (hapd->iconf->basic_rates)
114 		basic_rates = hapd->iconf->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 	if (hostapd_set_rate_sets(hapd, hapd->iconf->supported_rates,
130 				  basic_rates, mode->mode)) {
131 		wpa_printf(MSG_ERROR, "Failed to update rate sets in kernel "
132 			   "module");
133 	}
134 
135 	os_free(hapd->iface->current_rates);
136 	hapd->iface->num_rates = 0;
137 
138 	hapd->iface->current_rates =
139 		os_zalloc(mode->num_rates * sizeof(struct hostapd_rate_data));
140 	if (!hapd->iface->current_rates) {
141 		wpa_printf(MSG_ERROR, "Failed to allocate memory for rate "
142 			   "table.");
143 		return -1;
144 	}
145 
146 	for (i = 0; i < mode->num_rates; i++) {
147 		struct hostapd_rate_data *rate;
148 
149 		if (hapd->iconf->supported_rates &&
150 		    !hostapd_rate_found(hapd->iconf->supported_rates,
151 					mode->rates[i]))
152 			continue;
153 
154 		rate = &hapd->iface->current_rates[hapd->iface->num_rates];
155 		rate->rate = mode->rates[i];
156 		if (hostapd_rate_found(basic_rates, rate->rate)) {
157 			rate->flags |= HOSTAPD_RATE_BASIC;
158 			num_basic_rates++;
159 		}
160 		wpa_printf(MSG_DEBUG, "RATE[%d] rate=%d flags=0x%x",
161 			   hapd->iface->num_rates, rate->rate, rate->flags);
162 		hapd->iface->num_rates++;
163 	}
164 
165 	if ((hapd->iface->num_rates == 0 || num_basic_rates == 0) &&
166 	    (!hapd->iconf->ieee80211n || !hapd->iconf->require_ht)) {
167 		wpa_printf(MSG_ERROR, "No rates remaining in supported/basic "
168 			   "rate sets (%d,%d).",
169 			   hapd->iface->num_rates, num_basic_rates);
170 		return -1;
171 	}
172 
173 	return 0;
174 }
175 
176 
177 #ifdef CONFIG_IEEE80211N
ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface * iface)178 static int ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface *iface)
179 {
180 	int sec_chan, ok, j, first;
181 	int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
182 			  184, 192 };
183 	size_t k;
184 
185 	if (!iface->conf->secondary_channel)
186 		return 1; /* HT40 not used */
187 
188 	sec_chan = iface->conf->channel + iface->conf->secondary_channel * 4;
189 	wpa_printf(MSG_DEBUG, "HT40: control channel: %d  "
190 		   "secondary channel: %d",
191 		   iface->conf->channel, sec_chan);
192 
193 	/* Verify that HT40 secondary channel is an allowed 20 MHz
194 	 * channel */
195 	ok = 0;
196 	for (j = 0; j < iface->current_mode->num_channels; j++) {
197 		struct hostapd_channel_data *chan =
198 			&iface->current_mode->channels[j];
199 		if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
200 		    chan->chan == sec_chan) {
201 			ok = 1;
202 			break;
203 		}
204 	}
205 	if (!ok) {
206 		wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
207 			   sec_chan);
208 		return 0;
209 	}
210 
211 	/*
212 	 * Verify that HT40 primary,secondary channel pair is allowed per
213 	 * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
214 	 * 2.4 GHz rules allow all cases where the secondary channel fits into
215 	 * the list of allowed channels (already checked above).
216 	 */
217 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
218 		return 1;
219 
220 	if (iface->conf->secondary_channel > 0)
221 		first = iface->conf->channel;
222 	else
223 		first = sec_chan;
224 
225 	ok = 0;
226 	for (k = 0; k < sizeof(allowed) / sizeof(allowed[0]); k++) {
227 		if (first == allowed[k]) {
228 			ok = 1;
229 			break;
230 		}
231 	}
232 	if (!ok) {
233 		wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
234 			   iface->conf->channel,
235 			   iface->conf->secondary_channel);
236 		return 0;
237 	}
238 
239 	return 1;
240 }
241 
242 
ieee80211n_switch_pri_sec(struct hostapd_iface * iface)243 static void ieee80211n_switch_pri_sec(struct hostapd_iface *iface)
244 {
245 	if (iface->conf->secondary_channel > 0) {
246 		iface->conf->channel += 4;
247 		iface->conf->secondary_channel = -1;
248 	} else {
249 		iface->conf->channel -= 4;
250 		iface->conf->secondary_channel = 1;
251 	}
252 }
253 
254 
ieee80211n_get_pri_sec_chan(struct wpa_scan_res * bss,int * pri_chan,int * sec_chan)255 static void ieee80211n_get_pri_sec_chan(struct wpa_scan_res *bss,
256 					int *pri_chan, int *sec_chan)
257 {
258 	struct ieee80211_ht_operation *oper;
259 	struct ieee802_11_elems elems;
260 
261 	*pri_chan = *sec_chan = 0;
262 
263 	ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
264 	if (elems.ht_operation &&
265 	    elems.ht_operation_len >= sizeof(*oper)) {
266 		oper = (struct ieee80211_ht_operation *) elems.ht_operation;
267 		*pri_chan = oper->control_chan;
268 		if (oper->ht_param & HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH) {
269 			int sec = oper->ht_param &
270 				HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
271 			if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
272 				*sec_chan = *pri_chan + 4;
273 			else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
274 				*sec_chan = *pri_chan - 4;
275 		}
276 	}
277 }
278 
279 
ieee80211n_check_40mhz_5g(struct hostapd_iface * iface,struct wpa_scan_results * scan_res)280 static int ieee80211n_check_40mhz_5g(struct hostapd_iface *iface,
281 				     struct wpa_scan_results *scan_res)
282 {
283 	int pri_chan, sec_chan, pri_freq, sec_freq, pri_bss, sec_bss;
284 	int bss_pri_chan, bss_sec_chan;
285 	size_t i;
286 	int match;
287 
288 	pri_chan = iface->conf->channel;
289 	sec_chan = iface->conf->secondary_channel * 4;
290 	pri_freq = hostapd_hw_get_freq(iface->bss[0], pri_chan);
291 	if (iface->conf->secondary_channel > 0)
292 		sec_freq = pri_freq + 20;
293 	else
294 		sec_freq = pri_freq - 20;
295 
296 	/*
297 	 * Switch PRI/SEC channels if Beacons were detected on selected SEC
298 	 * channel, but not on selected PRI channel.
299 	 */
300 	pri_bss = sec_bss = 0;
301 	for (i = 0; i < scan_res->num; i++) {
302 		struct wpa_scan_res *bss = scan_res->res[i];
303 		if (bss->freq == pri_freq)
304 			pri_bss++;
305 		else if (bss->freq == sec_freq)
306 			sec_bss++;
307 	}
308 	if (sec_bss && !pri_bss) {
309 		wpa_printf(MSG_INFO, "Switch own primary and secondary "
310 			   "channel to get secondary channel with no Beacons "
311 			   "from other BSSes");
312 		ieee80211n_switch_pri_sec(iface);
313 	}
314 
315 	/*
316 	 * Match PRI/SEC channel with any existing HT40 BSS on the same
317 	 * channels that we are about to use (if already mixed order in
318 	 * existing BSSes, use own preference).
319 	 */
320 	match = 0;
321 	for (i = 0; i < scan_res->num; i++) {
322 		struct wpa_scan_res *bss = scan_res->res[i];
323 		ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
324 		if (pri_chan == bss_pri_chan &&
325 		    sec_chan == bss_sec_chan) {
326 			match = 1;
327 			break;
328 		}
329 	}
330 	if (!match) {
331 		for (i = 0; i < scan_res->num; i++) {
332 			struct wpa_scan_res *bss = scan_res->res[i];
333 			ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan,
334 						    &bss_sec_chan);
335 			if (pri_chan == bss_sec_chan &&
336 			    sec_chan == bss_pri_chan) {
337 				wpa_printf(MSG_INFO, "Switch own primary and "
338 					   "secondary channel due to BSS "
339 					   "overlap with " MACSTR,
340 					   MAC2STR(bss->bssid));
341 				ieee80211n_switch_pri_sec(iface);
342 				break;
343 			}
344 		}
345 	}
346 
347 	return 1;
348 }
349 
350 
ieee80211n_check_40mhz_2g4(struct hostapd_iface * iface,struct wpa_scan_results * scan_res)351 static int ieee80211n_check_40mhz_2g4(struct hostapd_iface *iface,
352 				      struct wpa_scan_results *scan_res)
353 {
354 	int pri_freq, sec_freq;
355 	int affected_start, affected_end;
356 	size_t i;
357 
358 	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
359 	if (iface->conf->secondary_channel > 0)
360 		sec_freq = pri_freq + 20;
361 	else
362 		sec_freq = pri_freq - 20;
363 	affected_start = (pri_freq + sec_freq) / 2 - 25;
364 	affected_end = (pri_freq + sec_freq) / 2 + 25;
365 	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
366 		   affected_start, affected_end);
367 	for (i = 0; i < scan_res->num; i++) {
368 		struct wpa_scan_res *bss = scan_res->res[i];
369 		int pri = bss->freq;
370 		int sec = pri;
371 		int sec_chan, pri_chan;
372 
373 		ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
374 
375 		if (sec_chan) {
376 			if (sec_chan < pri_chan)
377 				sec = pri - 20;
378 			else
379 				sec = pri + 20;
380 		}
381 
382 		if ((pri < affected_start || pri > affected_end) &&
383 		    (sec < affected_start || sec > affected_end))
384 			continue; /* not within affected channel range */
385 
386 		wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
387 			   " freq=%d pri=%d sec=%d",
388 			   MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
389 
390 		if (sec_chan) {
391 			if (pri_freq != pri || sec_freq != sec) {
392 				wpa_printf(MSG_DEBUG, "40 MHz pri/sec "
393 					   "mismatch with BSS " MACSTR
394 					   " <%d,%d> (chan=%d%c) vs. <%d,%d>",
395 					   MAC2STR(bss->bssid),
396 					   pri, sec, pri_chan,
397 					   sec > pri ? '+' : '-',
398 					   pri_freq, sec_freq);
399 				return 0;
400 			}
401 		}
402 
403 		/* TODO: 40 MHz intolerant */
404 	}
405 
406 	return 1;
407 }
408 
409 
wpa_scan_results_free(struct wpa_scan_results * res)410 static void wpa_scan_results_free(struct wpa_scan_results *res)
411 {
412 	size_t i;
413 
414 	if (res == NULL)
415 		return;
416 
417 	for (i = 0; i < res->num; i++)
418 		os_free(res->res[i]);
419 	os_free(res->res);
420 	os_free(res);
421 }
422 
423 
ieee80211n_check_scan(struct hostapd_iface * iface)424 static void ieee80211n_check_scan(struct hostapd_iface *iface)
425 {
426 	struct wpa_scan_results *scan_res;
427 	int oper40;
428 	int res;
429 
430 	/* Check list of neighboring BSSes (from scan) to see whether 40 MHz is
431 	 * allowed per IEEE 802.11n/D7.0, 11.14.3.2 */
432 
433 	iface->scan_cb = NULL;
434 
435 	scan_res = hostapd_driver_get_scan_results(iface->bss[0]);
436 	if (scan_res == NULL) {
437 		hostapd_setup_interface_complete(iface, 1);
438 		return;
439 	}
440 
441 	if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A)
442 		oper40 = ieee80211n_check_40mhz_5g(iface, scan_res);
443 	else
444 		oper40 = ieee80211n_check_40mhz_2g4(iface, scan_res);
445 	wpa_scan_results_free(scan_res);
446 
447 	if (!oper40) {
448 		wpa_printf(MSG_INFO, "20/40 MHz operation not permitted on "
449 			   "channel pri=%d sec=%d based on overlapping BSSes",
450 			   iface->conf->channel,
451 			   iface->conf->channel +
452 			   iface->conf->secondary_channel * 4);
453 		iface->conf->secondary_channel = 0;
454 		iface->conf->ht_capab &= ~HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET;
455 	}
456 
457 	res = ieee80211n_allowed_ht40_channel_pair(iface);
458 	hostapd_setup_interface_complete(iface, !res);
459 }
460 
461 
ieee80211n_check_40mhz(struct hostapd_iface * iface)462 static int ieee80211n_check_40mhz(struct hostapd_iface *iface)
463 {
464 	struct wpa_driver_scan_params params;
465 
466 	if (!iface->conf->secondary_channel)
467 		return 0; /* HT40 not used */
468 
469 	wpa_printf(MSG_DEBUG, "Scan for neighboring BSSes prior to enabling "
470 		   "40 MHz channel");
471 	os_memset(&params, 0, sizeof(params));
472 	/* TODO: scan only the needed frequency */
473 	if (hostapd_driver_scan(iface->bss[0], &params) < 0) {
474 		wpa_printf(MSG_ERROR, "Failed to request a scan of "
475 			   "neighboring BSSes");
476 		return -1;
477 	}
478 
479 	iface->scan_cb = ieee80211n_check_scan;
480 	return 1;
481 }
482 
483 
ieee80211n_supported_ht_capab(struct hostapd_iface * iface)484 static int ieee80211n_supported_ht_capab(struct hostapd_iface *iface)
485 {
486 	u16 hw = iface->current_mode->ht_capab;
487 	u16 conf = iface->conf->ht_capab;
488 
489 	if ((conf & HT_CAP_INFO_LDPC_CODING_CAP) &&
490 	    !(hw & HT_CAP_INFO_LDPC_CODING_CAP)) {
491 		wpa_printf(MSG_ERROR, "Driver does not support configured "
492 			   "HT capability [LDPC]");
493 		return 0;
494 	}
495 
496 	if ((conf & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
497 	    !(hw & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
498 		wpa_printf(MSG_ERROR, "Driver does not support configured "
499 			   "HT capability [HT40*]");
500 		return 0;
501 	}
502 
503 	if ((conf & HT_CAP_INFO_SMPS_MASK) != (hw & HT_CAP_INFO_SMPS_MASK) &&
504 	    (conf & HT_CAP_INFO_SMPS_MASK) != HT_CAP_INFO_SMPS_DISABLED) {
505 		wpa_printf(MSG_ERROR, "Driver does not support configured "
506 			   "HT capability [SMPS-*]");
507 		return 0;
508 	}
509 
510 	if ((conf & HT_CAP_INFO_GREEN_FIELD) &&
511 	    !(hw & HT_CAP_INFO_GREEN_FIELD)) {
512 		wpa_printf(MSG_ERROR, "Driver does not support configured "
513 			   "HT capability [GF]");
514 		return 0;
515 	}
516 
517 	if ((conf & HT_CAP_INFO_SHORT_GI20MHZ) &&
518 	    !(hw & HT_CAP_INFO_SHORT_GI20MHZ)) {
519 		wpa_printf(MSG_ERROR, "Driver does not support configured "
520 			   "HT capability [SHORT-GI-20]");
521 		return 0;
522 	}
523 
524 	if ((conf & HT_CAP_INFO_SHORT_GI40MHZ) &&
525 	    !(hw & HT_CAP_INFO_SHORT_GI40MHZ)) {
526 		wpa_printf(MSG_ERROR, "Driver does not support configured "
527 			   "HT capability [SHORT-GI-40]");
528 		return 0;
529 	}
530 
531 	if ((conf & HT_CAP_INFO_TX_STBC) && !(hw & HT_CAP_INFO_TX_STBC)) {
532 		wpa_printf(MSG_ERROR, "Driver does not support configured "
533 			   "HT capability [TX-STBC]");
534 		return 0;
535 	}
536 
537 	if ((conf & HT_CAP_INFO_RX_STBC_MASK) >
538 	    (hw & HT_CAP_INFO_RX_STBC_MASK)) {
539 		wpa_printf(MSG_ERROR, "Driver does not support configured "
540 			   "HT capability [RX-STBC*]");
541 		return 0;
542 	}
543 
544 	if ((conf & HT_CAP_INFO_DELAYED_BA) &&
545 	    !(hw & HT_CAP_INFO_DELAYED_BA)) {
546 		wpa_printf(MSG_ERROR, "Driver does not support configured "
547 			   "HT capability [DELAYED-BA]");
548 		return 0;
549 	}
550 
551 	if ((conf & HT_CAP_INFO_MAX_AMSDU_SIZE) &&
552 	    !(hw & HT_CAP_INFO_MAX_AMSDU_SIZE)) {
553 		wpa_printf(MSG_ERROR, "Driver does not support configured "
554 			   "HT capability [MAX-AMSDU-7935]");
555 		return 0;
556 	}
557 
558 	if ((conf & HT_CAP_INFO_DSSS_CCK40MHZ) &&
559 	    !(hw & HT_CAP_INFO_DSSS_CCK40MHZ)) {
560 		wpa_printf(MSG_ERROR, "Driver does not support configured "
561 			   "HT capability [DSSS_CCK-40]");
562 		return 0;
563 	}
564 
565 	if ((conf & HT_CAP_INFO_PSMP_SUPP) && !(hw & HT_CAP_INFO_PSMP_SUPP)) {
566 		wpa_printf(MSG_ERROR, "Driver does not support configured "
567 			   "HT capability [PSMP]");
568 		return 0;
569 	}
570 
571 	if ((conf & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT) &&
572 	    !(hw & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT)) {
573 		wpa_printf(MSG_ERROR, "Driver does not support configured "
574 			   "HT capability [LSIG-TXOP-PROT]");
575 		return 0;
576 	}
577 
578 	return 1;
579 }
580 
581 #endif /* CONFIG_IEEE80211N */
582 
583 
hostapd_check_ht_capab(struct hostapd_iface * iface)584 int hostapd_check_ht_capab(struct hostapd_iface *iface)
585 {
586 #ifdef CONFIG_IEEE80211N
587 	int ret;
588 	if (!iface->conf->ieee80211n)
589 		return 0;
590 	if (!ieee80211n_supported_ht_capab(iface))
591 		return -1;
592 	ret = ieee80211n_check_40mhz(iface);
593 	if (ret)
594 		return ret;
595 	if (!ieee80211n_allowed_ht40_channel_pair(iface))
596 		return -1;
597 #endif /* CONFIG_IEEE80211N */
598 
599 	return 0;
600 }
601 
602 
603 /**
604  * hostapd_select_hw_mode - Select the hardware mode
605  * @iface: Pointer to interface data.
606  * Returns: 0 on success, < 0 on failure
607  *
608  * Sets up the hardware mode, channel, rates, and passive scanning
609  * based on the configuration.
610  */
hostapd_select_hw_mode(struct hostapd_iface * iface)611 int hostapd_select_hw_mode(struct hostapd_iface *iface)
612 {
613 	int i, j, ok;
614 
615 	if (iface->num_hw_features < 1)
616 		return -1;
617 
618 	iface->current_mode = NULL;
619 	for (i = 0; i < iface->num_hw_features; i++) {
620 		struct hostapd_hw_modes *mode = &iface->hw_features[i];
621 		if (mode->mode == iface->conf->hw_mode) {
622 			iface->current_mode = mode;
623 			break;
624 		}
625 	}
626 
627 	if (iface->current_mode == NULL) {
628 		wpa_printf(MSG_ERROR, "Hardware does not support configured "
629 			   "mode");
630 		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
631 			       HOSTAPD_LEVEL_WARNING,
632 			       "Hardware does not support configured mode "
633 			       "(%d)", (int) iface->conf->hw_mode);
634 		return -2;
635 	}
636 
637 	ok = 0;
638 	for (j = 0; j < iface->current_mode->num_channels; j++) {
639 		struct hostapd_channel_data *chan =
640 			&iface->current_mode->channels[j];
641 		if (chan->chan == iface->conf->channel) {
642 			if (chan->flag & HOSTAPD_CHAN_DISABLED) {
643 				wpa_printf(MSG_ERROR,
644 					   "channel [%i] (%i) is disabled for "
645 					   "use in AP mode, flags: 0x%x",
646 					   j, chan->chan, chan->flag);
647 			} else {
648 				ok = 1;
649 				break;
650 			}
651 		}
652 	}
653 	if (ok && iface->conf->secondary_channel) {
654 		int sec_ok = 0;
655 		int sec_chan = iface->conf->channel +
656 			iface->conf->secondary_channel * 4;
657 		for (j = 0; j < iface->current_mode->num_channels; j++) {
658 			struct hostapd_channel_data *chan =
659 				&iface->current_mode->channels[j];
660 			if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
661 			    (chan->chan == sec_chan)) {
662 				sec_ok = 1;
663 				break;
664 			}
665 		}
666 		if (!sec_ok) {
667 			hostapd_logger(iface->bss[0], NULL,
668 				       HOSTAPD_MODULE_IEEE80211,
669 				       HOSTAPD_LEVEL_WARNING,
670 				       "Configured HT40 secondary channel "
671 				       "(%d) not found from the channel list "
672 				       "of current mode (%d) %s",
673 				       sec_chan, iface->current_mode->mode,
674 				       hostapd_hw_mode_txt(
675 					       iface->current_mode->mode));
676 			ok = 0;
677 		}
678 	}
679 	if (iface->conf->channel == 0) {
680 		/* TODO: could request a scan of neighboring BSSes and select
681 		 * the channel automatically */
682 		wpa_printf(MSG_ERROR, "Channel not configured "
683 			   "(hw_mode/channel in hostapd.conf)");
684 		return -3;
685 	}
686 	if (ok == 0 && iface->conf->channel != 0) {
687 		hostapd_logger(iface->bss[0], NULL,
688 			       HOSTAPD_MODULE_IEEE80211,
689 			       HOSTAPD_LEVEL_WARNING,
690 			       "Configured channel (%d) not found from the "
691 			       "channel list of current mode (%d) %s",
692 			       iface->conf->channel,
693 			       iface->current_mode->mode,
694 			       hostapd_hw_mode_txt(iface->current_mode->mode));
695 		iface->current_mode = NULL;
696 	}
697 
698 	if (iface->current_mode == NULL) {
699 		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
700 			       HOSTAPD_LEVEL_WARNING,
701 			       "Hardware does not support configured channel");
702 		return -4;
703 	}
704 
705 	return 0;
706 }
707 
708 
hostapd_hw_mode_txt(int mode)709 const char * hostapd_hw_mode_txt(int mode)
710 {
711 	switch (mode) {
712 	case HOSTAPD_MODE_IEEE80211A:
713 		return "IEEE 802.11a";
714 	case HOSTAPD_MODE_IEEE80211B:
715 		return "IEEE 802.11b";
716 	case HOSTAPD_MODE_IEEE80211G:
717 		return "IEEE 802.11g";
718 	default:
719 		return "UNKNOWN";
720 	}
721 }
722 
723 
hostapd_hw_get_freq(struct hostapd_data * hapd,int chan)724 int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
725 {
726 	int i;
727 
728 	if (!hapd->iface->current_mode)
729 		return 0;
730 
731 	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
732 		struct hostapd_channel_data *ch =
733 			&hapd->iface->current_mode->channels[i];
734 		if (ch->chan == chan)
735 			return ch->freq;
736 	}
737 
738 	return 0;
739 }
740 
741 
hostapd_hw_get_channel(struct hostapd_data * hapd,int freq)742 int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
743 {
744 	int i;
745 
746 	if (!hapd->iface->current_mode)
747 		return 0;
748 
749 	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
750 		struct hostapd_channel_data *ch =
751 			&hapd->iface->current_mode->channels[i];
752 		if (ch->freq == freq)
753 			return ch->chan;
754 	}
755 
756 	return 0;
757 }
758