hw_features.c revision 61d9df3e62aaa0e87ad05452fcb95142159a17b6
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@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
30void 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
47int 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
104int 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	os_free(iface->basic_rates);
133	iface->basic_rates = os_malloc(i * sizeof(int));
134	if (iface->basic_rates)
135		os_memcpy(iface->basic_rates, basic_rates, i * sizeof(int));
136
137	os_free(iface->current_rates);
138	iface->num_rates = 0;
139
140	iface->current_rates =
141		os_calloc(mode->num_rates, sizeof(struct hostapd_rate_data));
142	if (!iface->current_rates) {
143		wpa_printf(MSG_ERROR, "Failed to allocate memory for rate "
144			   "table.");
145		return -1;
146	}
147
148	for (i = 0; i < mode->num_rates; i++) {
149		struct hostapd_rate_data *rate;
150
151		if (iface->conf->supported_rates &&
152		    !hostapd_rate_found(iface->conf->supported_rates,
153					mode->rates[i]))
154			continue;
155
156		rate = &iface->current_rates[iface->num_rates];
157		rate->rate = mode->rates[i];
158		if (hostapd_rate_found(basic_rates, rate->rate)) {
159			rate->flags |= HOSTAPD_RATE_BASIC;
160			num_basic_rates++;
161		}
162		wpa_printf(MSG_DEBUG, "RATE[%d] rate=%d flags=0x%x",
163			   iface->num_rates, rate->rate, rate->flags);
164		iface->num_rates++;
165	}
166
167	if ((iface->num_rates == 0 || num_basic_rates == 0) &&
168	    (!iface->conf->ieee80211n || !iface->conf->require_ht)) {
169		wpa_printf(MSG_ERROR, "No rates remaining in supported/basic "
170			   "rate sets (%d,%d).",
171			   iface->num_rates, num_basic_rates);
172		return -1;
173	}
174
175	return 0;
176}
177
178
179#ifdef CONFIG_IEEE80211N
180static int ieee80211n_allowed_ht40_channel_pair(struct hostapd_iface *iface)
181{
182	int sec_chan, ok, j, first;
183	int allowed[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
184			  184, 192 };
185	size_t k;
186
187	if (!iface->conf->secondary_channel)
188		return 1; /* HT40 not used */
189
190	sec_chan = iface->conf->channel + iface->conf->secondary_channel * 4;
191	wpa_printf(MSG_DEBUG, "HT40: control channel: %d  "
192		   "secondary channel: %d",
193		   iface->conf->channel, sec_chan);
194
195	/* Verify that HT40 secondary channel is an allowed 20 MHz
196	 * channel */
197	ok = 0;
198	for (j = 0; j < iface->current_mode->num_channels; j++) {
199		struct hostapd_channel_data *chan =
200			&iface->current_mode->channels[j];
201		if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
202		    chan->chan == sec_chan) {
203			ok = 1;
204			break;
205		}
206	}
207	if (!ok) {
208		wpa_printf(MSG_ERROR, "HT40 secondary channel %d not allowed",
209			   sec_chan);
210		return 0;
211	}
212
213	/*
214	 * Verify that HT40 primary,secondary channel pair is allowed per
215	 * IEEE 802.11n Annex J. This is only needed for 5 GHz band since
216	 * 2.4 GHz rules allow all cases where the secondary channel fits into
217	 * the list of allowed channels (already checked above).
218	 */
219	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
220		return 1;
221
222	if (iface->conf->secondary_channel > 0)
223		first = iface->conf->channel;
224	else
225		first = sec_chan;
226
227	ok = 0;
228	for (k = 0; k < sizeof(allowed) / sizeof(allowed[0]); k++) {
229		if (first == allowed[k]) {
230			ok = 1;
231			break;
232		}
233	}
234	if (!ok) {
235		wpa_printf(MSG_ERROR, "HT40 channel pair (%d, %d) not allowed",
236			   iface->conf->channel,
237			   iface->conf->secondary_channel);
238		return 0;
239	}
240
241	return 1;
242}
243
244
245static void ieee80211n_switch_pri_sec(struct hostapd_iface *iface)
246{
247	if (iface->conf->secondary_channel > 0) {
248		iface->conf->channel += 4;
249		iface->conf->secondary_channel = -1;
250	} else {
251		iface->conf->channel -= 4;
252		iface->conf->secondary_channel = 1;
253	}
254}
255
256
257static void ieee80211n_get_pri_sec_chan(struct wpa_scan_res *bss,
258					int *pri_chan, int *sec_chan)
259{
260	struct ieee80211_ht_operation *oper;
261	struct ieee802_11_elems elems;
262
263	*pri_chan = *sec_chan = 0;
264
265	ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems, 0);
266	if (elems.ht_operation &&
267	    elems.ht_operation_len >= sizeof(*oper)) {
268		oper = (struct ieee80211_ht_operation *) elems.ht_operation;
269		*pri_chan = oper->control_chan;
270		if (oper->ht_param & HT_INFO_HT_PARAM_REC_TRANS_CHNL_WIDTH) {
271			int sec = oper->ht_param &
272				HT_INFO_HT_PARAM_SECONDARY_CHNL_OFF_MASK;
273			if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_ABOVE)
274				*sec_chan = *pri_chan + 4;
275			else if (sec == HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW)
276				*sec_chan = *pri_chan - 4;
277		}
278	}
279}
280
281
282static int ieee80211n_check_40mhz_5g(struct hostapd_iface *iface,
283				     struct wpa_scan_results *scan_res)
284{
285	int pri_chan, sec_chan, pri_freq, sec_freq, pri_bss, sec_bss;
286	int bss_pri_chan, bss_sec_chan;
287	size_t i;
288	int match;
289
290	pri_chan = iface->conf->channel;
291	sec_chan = iface->conf->secondary_channel * 4;
292	pri_freq = hostapd_hw_get_freq(iface->bss[0], pri_chan);
293	if (iface->conf->secondary_channel > 0)
294		sec_freq = pri_freq + 20;
295	else
296		sec_freq = pri_freq - 20;
297
298	/*
299	 * Switch PRI/SEC channels if Beacons were detected on selected SEC
300	 * channel, but not on selected PRI channel.
301	 */
302	pri_bss = sec_bss = 0;
303	for (i = 0; i < scan_res->num; i++) {
304		struct wpa_scan_res *bss = scan_res->res[i];
305		if (bss->freq == pri_freq)
306			pri_bss++;
307		else if (bss->freq == sec_freq)
308			sec_bss++;
309	}
310	if (sec_bss && !pri_bss) {
311		wpa_printf(MSG_INFO, "Switch own primary and secondary "
312			   "channel to get secondary channel with no Beacons "
313			   "from other BSSes");
314		ieee80211n_switch_pri_sec(iface);
315	}
316
317	/*
318	 * Match PRI/SEC channel with any existing HT40 BSS on the same
319	 * channels that we are about to use (if already mixed order in
320	 * existing BSSes, use own preference).
321	 */
322	match = 0;
323	for (i = 0; i < scan_res->num; i++) {
324		struct wpa_scan_res *bss = scan_res->res[i];
325		ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan, &bss_sec_chan);
326		if (pri_chan == bss_pri_chan &&
327		    sec_chan == bss_sec_chan) {
328			match = 1;
329			break;
330		}
331	}
332	if (!match) {
333		for (i = 0; i < scan_res->num; i++) {
334			struct wpa_scan_res *bss = scan_res->res[i];
335			ieee80211n_get_pri_sec_chan(bss, &bss_pri_chan,
336						    &bss_sec_chan);
337			if (pri_chan == bss_sec_chan &&
338			    sec_chan == bss_pri_chan) {
339				wpa_printf(MSG_INFO, "Switch own primary and "
340					   "secondary channel due to BSS "
341					   "overlap with " MACSTR,
342					   MAC2STR(bss->bssid));
343				ieee80211n_switch_pri_sec(iface);
344				break;
345			}
346		}
347	}
348
349	return 1;
350}
351
352
353static int ieee80211n_check_40mhz_2g4(struct hostapd_iface *iface,
354				      struct wpa_scan_results *scan_res)
355{
356	int pri_freq, sec_freq;
357	int affected_start, affected_end;
358	size_t i;
359
360	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
361	if (iface->conf->secondary_channel > 0)
362		sec_freq = pri_freq + 20;
363	else
364		sec_freq = pri_freq - 20;
365	affected_start = (pri_freq + sec_freq) / 2 - 25;
366	affected_end = (pri_freq + sec_freq) / 2 + 25;
367	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
368		   affected_start, affected_end);
369	for (i = 0; i < scan_res->num; i++) {
370		struct wpa_scan_res *bss = scan_res->res[i];
371		int pri = bss->freq;
372		int sec = pri;
373		int sec_chan, pri_chan;
374
375		ieee80211n_get_pri_sec_chan(bss, &pri_chan, &sec_chan);
376
377		if (sec_chan) {
378			if (sec_chan < pri_chan)
379				sec = pri - 20;
380			else
381				sec = pri + 20;
382		}
383
384		if ((pri < affected_start || pri > affected_end) &&
385		    (sec < affected_start || sec > affected_end))
386			continue; /* not within affected channel range */
387
388		wpa_printf(MSG_DEBUG, "Neighboring BSS: " MACSTR
389			   " freq=%d pri=%d sec=%d",
390			   MAC2STR(bss->bssid), bss->freq, pri_chan, sec_chan);
391
392		if (sec_chan) {
393			if (pri_freq != pri || sec_freq != sec) {
394				wpa_printf(MSG_DEBUG, "40 MHz pri/sec "
395					   "mismatch with BSS " MACSTR
396					   " <%d,%d> (chan=%d%c) vs. <%d,%d>",
397					   MAC2STR(bss->bssid),
398					   pri, sec, pri_chan,
399					   sec > pri ? '+' : '-',
400					   pri_freq, sec_freq);
401				return 0;
402			}
403		}
404
405		/* TODO: 40 MHz intolerant */
406	}
407
408	return 1;
409}
410
411
412static void ieee80211n_check_scan(struct hostapd_iface *iface)
413{
414	struct wpa_scan_results *scan_res;
415	int oper40;
416	int res;
417
418	/* Check list of neighboring BSSes (from scan) to see whether 40 MHz is
419	 * allowed per IEEE Std 802.11-2012, 10.15.3.2 */
420
421	iface->scan_cb = NULL;
422
423	scan_res = hostapd_driver_get_scan_results(iface->bss[0]);
424	if (scan_res == NULL) {
425		hostapd_setup_interface_complete(iface, 1);
426		return;
427	}
428
429	if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A)
430		oper40 = ieee80211n_check_40mhz_5g(iface, scan_res);
431	else
432		oper40 = ieee80211n_check_40mhz_2g4(iface, scan_res);
433	wpa_scan_results_free(scan_res);
434
435	if (!oper40) {
436		wpa_printf(MSG_INFO, "20/40 MHz operation not permitted on "
437			   "channel pri=%d sec=%d based on overlapping BSSes",
438			   iface->conf->channel,
439			   iface->conf->channel +
440			   iface->conf->secondary_channel * 4);
441		iface->conf->secondary_channel = 0;
442		iface->conf->ht_capab &= ~HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET;
443	}
444
445	res = ieee80211n_allowed_ht40_channel_pair(iface);
446	hostapd_setup_interface_complete(iface, !res);
447}
448
449
450static void ieee80211n_scan_channels_2g4(struct hostapd_iface *iface,
451					 struct wpa_driver_scan_params *params)
452{
453	/* Scan only the affected frequency range */
454	int pri_freq, sec_freq;
455	int affected_start, affected_end;
456	int i, pos;
457	struct hostapd_hw_modes *mode;
458
459	if (iface->current_mode == NULL)
460		return;
461
462	pri_freq = hostapd_hw_get_freq(iface->bss[0], iface->conf->channel);
463	if (iface->conf->secondary_channel > 0)
464		sec_freq = pri_freq + 20;
465	else
466		sec_freq = pri_freq - 20;
467	affected_start = (pri_freq + sec_freq) / 2 - 25;
468	affected_end = (pri_freq + sec_freq) / 2 + 25;
469	wpa_printf(MSG_DEBUG, "40 MHz affected channel range: [%d,%d] MHz",
470		   affected_start, affected_end);
471
472	mode = iface->current_mode;
473	params->freqs = os_calloc(mode->num_channels + 1, sizeof(int));
474	if (params->freqs == NULL)
475		return;
476	pos = 0;
477
478	for (i = 0; i < mode->num_channels; i++) {
479		struct hostapd_channel_data *chan = &mode->channels[i];
480		if (chan->flag & HOSTAPD_CHAN_DISABLED)
481			continue;
482		if (chan->freq < affected_start ||
483		    chan->freq > affected_end)
484			continue;
485		params->freqs[pos++] = chan->freq;
486	}
487}
488
489
490static int ieee80211n_check_40mhz(struct hostapd_iface *iface)
491{
492	struct wpa_driver_scan_params params;
493
494	if (!iface->conf->secondary_channel)
495		return 0; /* HT40 not used */
496
497	wpa_printf(MSG_DEBUG, "Scan for neighboring BSSes prior to enabling "
498		   "40 MHz channel");
499	os_memset(&params, 0, sizeof(params));
500	if (iface->current_mode->mode == HOSTAPD_MODE_IEEE80211G)
501		ieee80211n_scan_channels_2g4(iface, &params);
502	if (hostapd_driver_scan(iface->bss[0], &params) < 0) {
503		wpa_printf(MSG_ERROR, "Failed to request a scan of "
504			   "neighboring BSSes");
505		os_free(params.freqs);
506		return -1;
507	}
508	os_free(params.freqs);
509
510	iface->scan_cb = ieee80211n_check_scan;
511	return 1;
512}
513
514
515static int ieee80211n_supported_ht_capab(struct hostapd_iface *iface)
516{
517	u16 hw = iface->current_mode->ht_capab;
518	u16 conf = iface->conf->ht_capab;
519
520	if ((conf & HT_CAP_INFO_LDPC_CODING_CAP) &&
521	    !(hw & HT_CAP_INFO_LDPC_CODING_CAP)) {
522		wpa_printf(MSG_ERROR, "Driver does not support configured "
523			   "HT capability [LDPC]");
524		return 0;
525	}
526
527	if ((conf & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET) &&
528	    !(hw & HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
529		wpa_printf(MSG_ERROR, "Driver does not support configured "
530			   "HT capability [HT40*]");
531		return 0;
532	}
533
534	if ((conf & HT_CAP_INFO_SMPS_MASK) != (hw & HT_CAP_INFO_SMPS_MASK) &&
535	    (conf & HT_CAP_INFO_SMPS_MASK) != HT_CAP_INFO_SMPS_DISABLED) {
536		wpa_printf(MSG_ERROR, "Driver does not support configured "
537			   "HT capability [SMPS-*]");
538		return 0;
539	}
540
541	if ((conf & HT_CAP_INFO_GREEN_FIELD) &&
542	    !(hw & HT_CAP_INFO_GREEN_FIELD)) {
543		wpa_printf(MSG_ERROR, "Driver does not support configured "
544			   "HT capability [GF]");
545		return 0;
546	}
547
548	if ((conf & HT_CAP_INFO_SHORT_GI20MHZ) &&
549	    !(hw & HT_CAP_INFO_SHORT_GI20MHZ)) {
550		wpa_printf(MSG_ERROR, "Driver does not support configured "
551			   "HT capability [SHORT-GI-20]");
552		return 0;
553	}
554
555	if ((conf & HT_CAP_INFO_SHORT_GI40MHZ) &&
556	    !(hw & HT_CAP_INFO_SHORT_GI40MHZ)) {
557		wpa_printf(MSG_ERROR, "Driver does not support configured "
558			   "HT capability [SHORT-GI-40]");
559		return 0;
560	}
561
562	if ((conf & HT_CAP_INFO_TX_STBC) && !(hw & HT_CAP_INFO_TX_STBC)) {
563		wpa_printf(MSG_ERROR, "Driver does not support configured "
564			   "HT capability [TX-STBC]");
565		return 0;
566	}
567
568	if ((conf & HT_CAP_INFO_RX_STBC_MASK) >
569	    (hw & HT_CAP_INFO_RX_STBC_MASK)) {
570		wpa_printf(MSG_ERROR, "Driver does not support configured "
571			   "HT capability [RX-STBC*]");
572		return 0;
573	}
574
575	if ((conf & HT_CAP_INFO_DELAYED_BA) &&
576	    !(hw & HT_CAP_INFO_DELAYED_BA)) {
577		wpa_printf(MSG_ERROR, "Driver does not support configured "
578			   "HT capability [DELAYED-BA]");
579		return 0;
580	}
581
582	if ((conf & HT_CAP_INFO_MAX_AMSDU_SIZE) &&
583	    !(hw & HT_CAP_INFO_MAX_AMSDU_SIZE)) {
584		wpa_printf(MSG_ERROR, "Driver does not support configured "
585			   "HT capability [MAX-AMSDU-7935]");
586		return 0;
587	}
588
589	if ((conf & HT_CAP_INFO_DSSS_CCK40MHZ) &&
590	    !(hw & HT_CAP_INFO_DSSS_CCK40MHZ)) {
591		wpa_printf(MSG_ERROR, "Driver does not support configured "
592			   "HT capability [DSSS_CCK-40]");
593		return 0;
594	}
595
596	if ((conf & HT_CAP_INFO_PSMP_SUPP) && !(hw & HT_CAP_INFO_PSMP_SUPP)) {
597		wpa_printf(MSG_ERROR, "Driver does not support configured "
598			   "HT capability [PSMP]");
599		return 0;
600	}
601
602	if ((conf & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT) &&
603	    !(hw & HT_CAP_INFO_LSIG_TXOP_PROTECT_SUPPORT)) {
604		wpa_printf(MSG_ERROR, "Driver does not support configured "
605			   "HT capability [LSIG-TXOP-PROT]");
606		return 0;
607	}
608
609	return 1;
610}
611
612#endif /* CONFIG_IEEE80211N */
613
614
615int hostapd_check_ht_capab(struct hostapd_iface *iface)
616{
617#ifdef CONFIG_IEEE80211N
618	int ret;
619	if (!iface->conf->ieee80211n)
620		return 0;
621	if (!ieee80211n_supported_ht_capab(iface))
622		return -1;
623	ret = ieee80211n_check_40mhz(iface);
624	if (ret)
625		return ret;
626	if (!ieee80211n_allowed_ht40_channel_pair(iface))
627		return -1;
628#endif /* CONFIG_IEEE80211N */
629
630	return 0;
631}
632
633
634/**
635 * hostapd_select_hw_mode - Select the hardware mode
636 * @iface: Pointer to interface data.
637 * Returns: 0 on success, < 0 on failure
638 *
639 * Sets up the hardware mode, channel, rates, and passive scanning
640 * based on the configuration.
641 */
642int hostapd_select_hw_mode(struct hostapd_iface *iface)
643{
644	int i, j, ok;
645
646	if (iface->num_hw_features < 1)
647		return -1;
648
649	iface->current_mode = NULL;
650	for (i = 0; i < iface->num_hw_features; i++) {
651		struct hostapd_hw_modes *mode = &iface->hw_features[i];
652		if (mode->mode == iface->conf->hw_mode) {
653			iface->current_mode = mode;
654			break;
655		}
656	}
657
658	if (iface->current_mode == NULL) {
659		wpa_printf(MSG_ERROR, "Hardware does not support configured "
660			   "mode");
661		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
662			       HOSTAPD_LEVEL_WARNING,
663			       "Hardware does not support configured mode "
664			       "(%d) (hw_mode in hostapd.conf)",
665			       (int) iface->conf->hw_mode);
666		return -2;
667	}
668
669	ok = 0;
670	for (j = 0; j < iface->current_mode->num_channels; j++) {
671		struct hostapd_channel_data *chan =
672			&iface->current_mode->channels[j];
673		if (chan->chan == iface->conf->channel) {
674			if (chan->flag & HOSTAPD_CHAN_DISABLED) {
675				wpa_printf(MSG_ERROR,
676					   "channel [%i] (%i) is disabled for "
677					   "use in AP mode, flags: 0x%x%s%s%s",
678					   j, chan->chan, chan->flag,
679					   chan->flag & HOSTAPD_CHAN_NO_IBSS ?
680					   " NO-IBSS" : "",
681					   chan->flag &
682					   HOSTAPD_CHAN_PASSIVE_SCAN ?
683					   " PASSIVE-SCAN" : "",
684					   chan->flag & HOSTAPD_CHAN_RADAR ?
685					   " RADAR" : "");
686			} else {
687				ok = 1;
688				break;
689			}
690		}
691	}
692	if (ok && iface->conf->secondary_channel) {
693		int sec_ok = 0;
694		int sec_chan = iface->conf->channel +
695			iface->conf->secondary_channel * 4;
696		for (j = 0; j < iface->current_mode->num_channels; j++) {
697			struct hostapd_channel_data *chan =
698				&iface->current_mode->channels[j];
699			if (!(chan->flag & HOSTAPD_CHAN_DISABLED) &&
700			    (chan->chan == sec_chan)) {
701				sec_ok = 1;
702				break;
703			}
704		}
705		if (!sec_ok) {
706			hostapd_logger(iface->bss[0], NULL,
707				       HOSTAPD_MODULE_IEEE80211,
708				       HOSTAPD_LEVEL_WARNING,
709				       "Configured HT40 secondary channel "
710				       "(%d) not found from the channel list "
711				       "of current mode (%d) %s",
712				       sec_chan, iface->current_mode->mode,
713				       hostapd_hw_mode_txt(
714					       iface->current_mode->mode));
715			ok = 0;
716		}
717	}
718	if (iface->conf->channel == 0) {
719		/* TODO: could request a scan of neighboring BSSes and select
720		 * the channel automatically */
721		wpa_printf(MSG_ERROR, "Channel not configured "
722			   "(hw_mode/channel in hostapd.conf)");
723		return -3;
724	}
725	if (ok == 0 && iface->conf->channel != 0) {
726		hostapd_logger(iface->bss[0], NULL,
727			       HOSTAPD_MODULE_IEEE80211,
728			       HOSTAPD_LEVEL_WARNING,
729			       "Configured channel (%d) not found from the "
730			       "channel list of current mode (%d) %s",
731			       iface->conf->channel,
732			       iface->current_mode->mode,
733			       hostapd_hw_mode_txt(iface->current_mode->mode));
734		iface->current_mode = NULL;
735	}
736
737	if (iface->current_mode == NULL) {
738		hostapd_logger(iface->bss[0], NULL, HOSTAPD_MODULE_IEEE80211,
739			       HOSTAPD_LEVEL_WARNING,
740			       "Hardware does not support configured channel");
741		return -4;
742	}
743
744	return 0;
745}
746
747
748const char * hostapd_hw_mode_txt(int mode)
749{
750	switch (mode) {
751	case HOSTAPD_MODE_IEEE80211A:
752		return "IEEE 802.11a";
753	case HOSTAPD_MODE_IEEE80211B:
754		return "IEEE 802.11b";
755	case HOSTAPD_MODE_IEEE80211G:
756		return "IEEE 802.11g";
757	default:
758		return "UNKNOWN";
759	}
760}
761
762
763int hostapd_hw_get_freq(struct hostapd_data *hapd, int chan)
764{
765	int i;
766
767	if (!hapd->iface->current_mode)
768		return 0;
769
770	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
771		struct hostapd_channel_data *ch =
772			&hapd->iface->current_mode->channels[i];
773		if (ch->chan == chan)
774			return ch->freq;
775	}
776
777	return 0;
778}
779
780
781int hostapd_hw_get_channel(struct hostapd_data *hapd, int freq)
782{
783	int i;
784
785	if (!hapd->iface->current_mode)
786		return 0;
787
788	for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
789		struct hostapd_channel_data *ch =
790			&hapd->iface->current_mode->channels[i];
791		if (ch->freq == freq)
792			return ch->chan;
793	}
794
795	return 0;
796}
797