dfs.c revision df5a7e4c5c64890c2425bb47d665bbce4992b676
1/*
2 * DFS - Dynamic Frequency Selection
3 * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
4 * Copyright (c) 2013, Qualcomm Atheros, Inc.
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 "common/ieee802_11_defs.h"
14#include "common/wpa_ctrl.h"
15#include "hostapd.h"
16#include "ap_drv_ops.h"
17#include "drivers/driver.h"
18#include "dfs.h"
19
20
21static int dfs_get_used_n_chans(struct hostapd_iface *iface)
22{
23	int n_chans = 1;
24
25	if (iface->conf->ieee80211n && iface->conf->secondary_channel)
26		n_chans = 2;
27
28	if (iface->conf->ieee80211ac) {
29		switch (iface->conf->vht_oper_chwidth) {
30		case VHT_CHANWIDTH_USE_HT:
31			break;
32		case VHT_CHANWIDTH_80MHZ:
33			n_chans = 4;
34			break;
35		case VHT_CHANWIDTH_160MHZ:
36			n_chans = 8;
37			break;
38		default:
39			break;
40		}
41	}
42
43	return n_chans;
44}
45
46
47static int dfs_channel_available(struct hostapd_channel_data *chan,
48				 int skip_radar)
49{
50	/*
51	 * When radar detection happens, CSA is performed. However, there's no
52	 * time for CAC, so radar channels must be skipped when finding a new
53	 * channel for CSA, unless they are available for immediate use.
54	 */
55	if (skip_radar && (chan->flag & HOSTAPD_CHAN_RADAR) &&
56	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) !=
57	     HOSTAPD_CHAN_DFS_AVAILABLE))
58		return 0;
59
60	if (chan->flag & HOSTAPD_CHAN_DISABLED)
61		return 0;
62	if ((chan->flag & HOSTAPD_CHAN_RADAR) &&
63	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) ==
64	     HOSTAPD_CHAN_DFS_UNAVAILABLE))
65		return 0;
66	return 1;
67}
68
69
70static int dfs_is_chan_allowed(struct hostapd_channel_data *chan, int n_chans)
71{
72	/*
73	 * The tables contain first valid channel number based on channel width.
74	 * We will also choose this first channel as the control one.
75	 */
76	int allowed_40[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
77			     184, 192 };
78	/*
79	 * VHT80, valid channels based on center frequency:
80	 * 42, 58, 106, 122, 138, 155
81	 */
82	int allowed_80[] = { 36, 52, 100, 116, 132, 149 };
83	/*
84	 * VHT160 valid channels based on center frequency:
85	 * 50, 114
86	 */
87	int allowed_160[] = { 36, 100 };
88	int *allowed = allowed_40;
89	unsigned int i, allowed_no = 0;
90
91	switch (n_chans) {
92	case 2:
93		allowed = allowed_40;
94		allowed_no = ARRAY_SIZE(allowed_40);
95		break;
96	case 4:
97		allowed = allowed_80;
98		allowed_no = ARRAY_SIZE(allowed_80);
99		break;
100	case 8:
101		allowed = allowed_160;
102		allowed_no = ARRAY_SIZE(allowed_160);
103		break;
104	default:
105		wpa_printf(MSG_DEBUG, "Unknown width for %d channels", n_chans);
106		break;
107	}
108
109	for (i = 0; i < allowed_no; i++) {
110		if (chan->chan == allowed[i])
111			return 1;
112	}
113
114	return 0;
115}
116
117
118static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
119				    int first_chan_idx, int num_chans,
120				    int skip_radar)
121{
122	struct hostapd_channel_data *first_chan, *chan;
123	int i;
124
125	if (first_chan_idx + num_chans >= mode->num_channels)
126		return 0;
127
128	first_chan = &mode->channels[first_chan_idx];
129
130	for (i = 0; i < num_chans; i++) {
131		chan = &mode->channels[first_chan_idx + i];
132
133		if (first_chan->freq + i * 20 != chan->freq)
134			return 0;
135
136		if (!dfs_channel_available(chan, skip_radar))
137			return 0;
138	}
139
140	return 1;
141}
142
143
144static int is_in_chanlist(struct hostapd_iface *iface,
145			  struct hostapd_channel_data *chan)
146{
147	int *entry;
148
149	if (!iface->conf->chanlist)
150		return 1;
151
152	for (entry = iface->conf->chanlist; *entry != -1; entry++) {
153		if (*entry == chan->chan)
154			return 1;
155	}
156	return 0;
157}
158
159
160/*
161 * The function assumes HT40+ operation.
162 * Make sure to adjust the following variables after calling this:
163 *  - hapd->secondary_channel
164 *  - hapd->vht_oper_centr_freq_seg0_idx
165 *  - hapd->vht_oper_centr_freq_seg1_idx
166 */
167static int dfs_find_channel(struct hostapd_iface *iface,
168			    struct hostapd_channel_data **ret_chan,
169			    int idx, int skip_radar)
170{
171	struct hostapd_hw_modes *mode;
172	struct hostapd_channel_data *chan;
173	int i, channel_idx = 0, n_chans;
174
175	mode = iface->current_mode;
176	n_chans = dfs_get_used_n_chans(iface);
177
178	wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
179	for (i = 0; i < mode->num_channels; i++) {
180		chan = &mode->channels[i];
181
182		/* Skip HT40/VHT incompatible channels */
183		if (iface->conf->ieee80211n &&
184		    iface->conf->secondary_channel &&
185		    !dfs_is_chan_allowed(chan, n_chans))
186			continue;
187
188		/* Skip incompatible chandefs */
189		if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
190			continue;
191
192		if (!is_in_chanlist(iface, chan))
193			continue;
194
195		if (ret_chan && idx == channel_idx) {
196			wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
197			*ret_chan = chan;
198			return idx;
199		}
200		wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
201		channel_idx++;
202	}
203	return channel_idx;
204}
205
206
207static void dfs_adjust_vht_center_freq(struct hostapd_iface *iface,
208				       struct hostapd_channel_data *chan,
209				       int secondary_channel,
210				       u8 *vht_oper_centr_freq_seg0_idx,
211				       u8 *vht_oper_centr_freq_seg1_idx)
212{
213	if (!iface->conf->ieee80211ac)
214		return;
215
216	if (!chan)
217		return;
218
219	*vht_oper_centr_freq_seg1_idx = 0;
220
221	switch (iface->conf->vht_oper_chwidth) {
222	case VHT_CHANWIDTH_USE_HT:
223		if (secondary_channel == 1)
224			*vht_oper_centr_freq_seg0_idx = chan->chan + 2;
225		else if (secondary_channel == -1)
226			*vht_oper_centr_freq_seg0_idx = chan->chan - 2;
227		else
228			*vht_oper_centr_freq_seg0_idx = chan->chan;
229		break;
230	case VHT_CHANWIDTH_80MHZ:
231		*vht_oper_centr_freq_seg0_idx = chan->chan + 6;
232		break;
233	case VHT_CHANWIDTH_160MHZ:
234		*vht_oper_centr_freq_seg0_idx = chan->chan + 14;
235		break;
236	default:
237		wpa_printf(MSG_INFO, "DFS only VHT20/40/80/160 is supported now");
238		*vht_oper_centr_freq_seg0_idx = 0;
239		break;
240	}
241
242	wpa_printf(MSG_DEBUG, "DFS adjusting VHT center frequency: %d, %d",
243		   *vht_oper_centr_freq_seg0_idx,
244		   *vht_oper_centr_freq_seg1_idx);
245}
246
247
248/* Return start channel idx we will use for mode->channels[idx] */
249static int dfs_get_start_chan_idx(struct hostapd_iface *iface)
250{
251	struct hostapd_hw_modes *mode;
252	struct hostapd_channel_data *chan;
253	int channel_no = iface->conf->channel;
254	int res = -1, i;
255
256	/* HT40- */
257	if (iface->conf->ieee80211n && iface->conf->secondary_channel == -1)
258		channel_no -= 4;
259
260	/* VHT */
261	if (iface->conf->ieee80211ac) {
262		switch (iface->conf->vht_oper_chwidth) {
263		case VHT_CHANWIDTH_USE_HT:
264			break;
265		case VHT_CHANWIDTH_80MHZ:
266			channel_no =
267				iface->conf->vht_oper_centr_freq_seg0_idx - 6;
268			break;
269		case VHT_CHANWIDTH_160MHZ:
270			channel_no =
271				iface->conf->vht_oper_centr_freq_seg0_idx - 14;
272			break;
273		default:
274			wpa_printf(MSG_INFO,
275				   "DFS only VHT20/40/80/160 is supported now");
276			channel_no = -1;
277			break;
278		}
279	}
280
281	/* Get idx */
282	mode = iface->current_mode;
283	for (i = 0; i < mode->num_channels; i++) {
284		chan = &mode->channels[i];
285		if (chan->chan == channel_no) {
286			res = i;
287			break;
288		}
289	}
290
291	if (res == -1) {
292		wpa_printf(MSG_DEBUG,
293			   "DFS chan_idx seems wrong; num-ch: %d ch-no: %d conf-ch-no: %d 11n: %d sec-ch: %d vht-oper-width: %d",
294			   mode->num_channels, channel_no, iface->conf->channel,
295			   iface->conf->ieee80211n,
296			   iface->conf->secondary_channel,
297			   iface->conf->vht_oper_chwidth);
298
299		for (i = 0; i < mode->num_channels; i++) {
300			wpa_printf(MSG_DEBUG, "Available channel: %d",
301				   mode->channels[i].chan);
302		}
303	}
304
305	return res;
306}
307
308
309/* At least one channel have radar flag */
310static int dfs_check_chans_radar(struct hostapd_iface *iface,
311				 int start_chan_idx, int n_chans)
312{
313	struct hostapd_channel_data *channel;
314	struct hostapd_hw_modes *mode;
315	int i, res = 0;
316
317	mode = iface->current_mode;
318
319	for (i = 0; i < n_chans; i++) {
320		channel = &mode->channels[start_chan_idx + i];
321		if (channel->flag & HOSTAPD_CHAN_RADAR)
322			res++;
323	}
324
325	return res;
326}
327
328
329/* All channels available */
330static int dfs_check_chans_available(struct hostapd_iface *iface,
331				     int start_chan_idx, int n_chans)
332{
333	struct hostapd_channel_data *channel;
334	struct hostapd_hw_modes *mode;
335	int i;
336
337	mode = iface->current_mode;
338
339	for (i = 0; i < n_chans; i++) {
340		channel = &mode->channels[start_chan_idx + i];
341
342		if (channel->flag & HOSTAPD_CHAN_DISABLED)
343			break;
344
345		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
346			continue;
347
348		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) !=
349		    HOSTAPD_CHAN_DFS_AVAILABLE)
350			break;
351	}
352
353	return i == n_chans;
354}
355
356
357/* At least one channel unavailable */
358static int dfs_check_chans_unavailable(struct hostapd_iface *iface,
359				       int start_chan_idx,
360				       int n_chans)
361{
362	struct hostapd_channel_data *channel;
363	struct hostapd_hw_modes *mode;
364	int i, res = 0;
365
366	mode = iface->current_mode;
367
368	for (i = 0; i < n_chans; i++) {
369		channel = &mode->channels[start_chan_idx + i];
370		if (channel->flag & HOSTAPD_CHAN_DISABLED)
371			res++;
372		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) ==
373		    HOSTAPD_CHAN_DFS_UNAVAILABLE)
374			res++;
375	}
376
377	return res;
378}
379
380
381static struct hostapd_channel_data *
382dfs_get_valid_channel(struct hostapd_iface *iface,
383		      int *secondary_channel,
384		      u8 *vht_oper_centr_freq_seg0_idx,
385		      u8 *vht_oper_centr_freq_seg1_idx,
386		      int skip_radar)
387{
388	struct hostapd_hw_modes *mode;
389	struct hostapd_channel_data *chan = NULL;
390	int num_available_chandefs;
391	int chan_idx;
392	u32 _rand;
393
394	wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
395	*secondary_channel = 0;
396	*vht_oper_centr_freq_seg0_idx = 0;
397	*vht_oper_centr_freq_seg1_idx = 0;
398
399	if (iface->current_mode == NULL)
400		return NULL;
401
402	mode = iface->current_mode;
403	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
404		return NULL;
405
406	/* Get the count first */
407	num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
408	if (num_available_chandefs == 0)
409		return NULL;
410
411	os_get_random((u8 *) &_rand, sizeof(_rand));
412	chan_idx = _rand % num_available_chandefs;
413	dfs_find_channel(iface, &chan, chan_idx, skip_radar);
414
415	/* dfs_find_channel() calculations assume HT40+ */
416	if (iface->conf->secondary_channel)
417		*secondary_channel = 1;
418	else
419		*secondary_channel = 0;
420
421	dfs_adjust_vht_center_freq(iface, chan,
422				   *secondary_channel,
423				   vht_oper_centr_freq_seg0_idx,
424				   vht_oper_centr_freq_seg1_idx);
425
426	return chan;
427}
428
429
430static int set_dfs_state_freq(struct hostapd_iface *iface, int freq, u32 state)
431{
432	struct hostapd_hw_modes *mode;
433	struct hostapd_channel_data *chan = NULL;
434	int i;
435
436	mode = iface->current_mode;
437	if (mode == NULL)
438		return 0;
439
440	wpa_printf(MSG_DEBUG, "set_dfs_state 0x%X for %d MHz", state, freq);
441	for (i = 0; i < iface->current_mode->num_channels; i++) {
442		chan = &iface->current_mode->channels[i];
443		if (chan->freq == freq) {
444			if (chan->flag & HOSTAPD_CHAN_RADAR) {
445				chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
446				chan->flag |= state;
447				return 1; /* Channel found */
448			}
449		}
450	}
451	wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
452	return 0;
453}
454
455
456static int set_dfs_state(struct hostapd_iface *iface, int freq, int ht_enabled,
457			 int chan_offset, int chan_width, int cf1,
458			 int cf2, u32 state)
459{
460	int n_chans = 1, i;
461	struct hostapd_hw_modes *mode;
462	int frequency = freq;
463	int ret = 0;
464
465	mode = iface->current_mode;
466	if (mode == NULL)
467		return 0;
468
469	if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
470		wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
471		return 0;
472	}
473
474	/* Seems cf1 and chan_width is enough here */
475	switch (chan_width) {
476	case CHAN_WIDTH_20_NOHT:
477	case CHAN_WIDTH_20:
478		n_chans = 1;
479		if (frequency == 0)
480			frequency = cf1;
481		break;
482	case CHAN_WIDTH_40:
483		n_chans = 2;
484		frequency = cf1 - 10;
485		break;
486	case CHAN_WIDTH_80:
487		n_chans = 4;
488		frequency = cf1 - 30;
489		break;
490	case CHAN_WIDTH_160:
491		n_chans = 8;
492		frequency = cf1 - 70;
493		break;
494	default:
495		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
496			   chan_width);
497		break;
498	}
499
500	wpa_printf(MSG_DEBUG, "DFS freq: %dMHz, n_chans: %d", frequency,
501		   n_chans);
502	for (i = 0; i < n_chans; i++) {
503		ret += set_dfs_state_freq(iface, frequency, state);
504		frequency = frequency + 20;
505	}
506
507	return ret;
508}
509
510
511static int dfs_are_channels_overlapped(struct hostapd_iface *iface, int freq,
512				       int chan_width, int cf1, int cf2)
513{
514	int start_chan_idx;
515	struct hostapd_hw_modes *mode;
516	struct hostapd_channel_data *chan;
517	int n_chans, i, j, frequency = freq, radar_n_chans = 1;
518	u8 radar_chan;
519	int res = 0;
520
521	/* Our configuration */
522	mode = iface->current_mode;
523	start_chan_idx = dfs_get_start_chan_idx(iface);
524	n_chans = dfs_get_used_n_chans(iface);
525
526	/* Check we are on DFS channel(s) */
527	if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
528		return 0;
529
530	/* Reported via radar event */
531	switch (chan_width) {
532	case CHAN_WIDTH_20_NOHT:
533	case CHAN_WIDTH_20:
534		radar_n_chans = 1;
535		if (frequency == 0)
536			frequency = cf1;
537		break;
538	case CHAN_WIDTH_40:
539		radar_n_chans = 2;
540		frequency = cf1 - 10;
541		break;
542	case CHAN_WIDTH_80:
543		radar_n_chans = 4;
544		frequency = cf1 - 30;
545		break;
546	case CHAN_WIDTH_160:
547		radar_n_chans = 8;
548		frequency = cf1 - 70;
549		break;
550	default:
551		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
552			   chan_width);
553		break;
554	}
555
556	ieee80211_freq_to_chan(frequency, &radar_chan);
557
558	for (i = 0; i < n_chans; i++) {
559		chan = &mode->channels[start_chan_idx + i];
560		if (!(chan->flag & HOSTAPD_CHAN_RADAR))
561			continue;
562		for (j = 0; j < radar_n_chans; j++) {
563			wpa_printf(MSG_DEBUG, "checking our: %d, radar: %d",
564				   chan->chan, radar_chan + j * 4);
565			if (chan->chan == radar_chan + j * 4)
566				res++;
567		}
568	}
569
570	wpa_printf(MSG_DEBUG, "overlapped: %d", res);
571
572	return res;
573}
574
575
576static unsigned int dfs_get_cac_time(struct hostapd_iface *iface,
577				     int start_chan_idx, int n_chans)
578{
579	struct hostapd_channel_data *channel;
580	struct hostapd_hw_modes *mode;
581	int i;
582	unsigned int cac_time_ms = 0;
583
584	mode = iface->current_mode;
585
586	for (i = 0; i < n_chans; i++) {
587		channel = &mode->channels[start_chan_idx + i];
588		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
589			continue;
590		if (channel->dfs_cac_ms > cac_time_ms)
591			cac_time_ms = channel->dfs_cac_ms;
592	}
593
594	return cac_time_ms;
595}
596
597
598/*
599 * Main DFS handler
600 * 1 - continue channel/ap setup
601 * 0 - channel/ap setup will be continued after CAC
602 * -1 - hit critical error
603 */
604int hostapd_handle_dfs(struct hostapd_iface *iface)
605{
606	struct hostapd_channel_data *channel;
607	int res, n_chans, start_chan_idx;
608	int skip_radar = 0;
609
610	iface->cac_started = 0;
611
612	do {
613		/* Get start (first) channel for current configuration */
614		start_chan_idx = dfs_get_start_chan_idx(iface);
615		if (start_chan_idx == -1)
616			return -1;
617
618		/* Get number of used channels, depend on width */
619		n_chans = dfs_get_used_n_chans(iface);
620
621		/* Setup CAC time */
622		iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
623						     n_chans);
624
625		/* Check if any of configured channels require DFS */
626		res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
627		wpa_printf(MSG_DEBUG,
628			   "DFS %d channels required radar detection",
629			   res);
630		if (!res)
631			return 1;
632
633		/* Check if all channels are DFS available */
634		res = dfs_check_chans_available(iface, start_chan_idx, n_chans);
635		wpa_printf(MSG_DEBUG,
636			   "DFS all channels available, (SKIP CAC): %s",
637			   res ? "yes" : "no");
638		if (res)
639			return 1;
640
641		/* Check if any of configured channels is unavailable */
642		res = dfs_check_chans_unavailable(iface, start_chan_idx,
643						  n_chans);
644		wpa_printf(MSG_DEBUG, "DFS %d chans unavailable - choose other channel: %s",
645			   res, res ? "yes": "no");
646		if (res) {
647			int sec = 0;
648			u8 cf1 = 0, cf2 = 0;
649
650			channel = dfs_get_valid_channel(iface, &sec, &cf1, &cf2,
651							skip_radar);
652			if (!channel) {
653				wpa_printf(MSG_ERROR, "could not get valid channel");
654				return -1;
655			}
656
657			iface->freq = channel->freq;
658			iface->conf->channel = channel->chan;
659			iface->conf->secondary_channel = sec;
660			iface->conf->vht_oper_centr_freq_seg0_idx = cf1;
661			iface->conf->vht_oper_centr_freq_seg1_idx = cf2;
662		}
663	} while (res);
664
665	/* Finally start CAC */
666	hostapd_set_state(iface, HAPD_IFACE_DFS);
667	wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz", iface->freq);
668	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
669		"freq=%d chan=%d sec_chan=%d, width=%d, seg0=%d, seg1=%d, cac_time=%ds",
670		iface->freq,
671		iface->conf->channel, iface->conf->secondary_channel,
672		iface->conf->vht_oper_chwidth,
673		iface->conf->vht_oper_centr_freq_seg0_idx,
674		iface->conf->vht_oper_centr_freq_seg1_idx,
675		iface->dfs_cac_ms / 1000);
676
677	res = hostapd_start_dfs_cac(iface, iface->conf->hw_mode,
678				    iface->freq,
679				    iface->conf->channel,
680				    iface->conf->ieee80211n,
681				    iface->conf->ieee80211ac,
682				    iface->conf->secondary_channel,
683				    iface->conf->vht_oper_chwidth,
684				    iface->conf->vht_oper_centr_freq_seg0_idx,
685				    iface->conf->vht_oper_centr_freq_seg1_idx);
686
687	if (res) {
688		wpa_printf(MSG_ERROR, "DFS start_dfs_cac() failed, %d", res);
689		return -1;
690	}
691
692	return 0;
693}
694
695
696int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
697			     int ht_enabled, int chan_offset, int chan_width,
698			     int cf1, int cf2)
699{
700	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
701		"success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
702		success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
703
704	if (success) {
705		/* Complete iface/ap configuration */
706		set_dfs_state(iface, freq, ht_enabled, chan_offset,
707			      chan_width, cf1, cf2,
708			      HOSTAPD_CHAN_DFS_AVAILABLE);
709		iface->cac_started = 0;
710		hostapd_setup_interface_complete(iface, 0);
711	}
712
713	return 0;
714}
715
716
717static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
718{
719	struct hostapd_channel_data *channel;
720	int secondary_channel;
721	u8 vht_oper_centr_freq_seg0_idx = 0;
722	u8 vht_oper_centr_freq_seg1_idx = 0;
723	int skip_radar = 0;
724	int err = 1;
725
726	/* Radar detected during active CAC */
727	iface->cac_started = 0;
728	channel = dfs_get_valid_channel(iface, &secondary_channel,
729					&vht_oper_centr_freq_seg0_idx,
730					&vht_oper_centr_freq_seg1_idx,
731					skip_radar);
732
733	if (!channel) {
734		wpa_printf(MSG_ERROR, "No valid channel available");
735		hostapd_setup_interface_complete(iface, err);
736		return err;
737	}
738
739	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
740		   channel->chan);
741	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
742		"freq=%d chan=%d sec_chan=%d", channel->freq,
743		channel->chan, secondary_channel);
744
745	iface->freq = channel->freq;
746	iface->conf->channel = channel->chan;
747	iface->conf->secondary_channel = secondary_channel;
748	iface->conf->vht_oper_centr_freq_seg0_idx =
749		vht_oper_centr_freq_seg0_idx;
750	iface->conf->vht_oper_centr_freq_seg1_idx =
751		vht_oper_centr_freq_seg1_idx;
752	err = 0;
753
754	hostapd_setup_interface_complete(iface, err);
755	return err;
756}
757
758
759static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
760{
761	struct hostapd_channel_data *channel;
762	int secondary_channel;
763	u8 vht_oper_centr_freq_seg0_idx;
764	u8 vht_oper_centr_freq_seg1_idx;
765	int skip_radar = 1;
766	struct csa_settings csa_settings;
767	struct hostapd_data *hapd = iface->bss[0];
768	int err = 1;
769
770	wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
771		   __func__, iface->cac_started ? "yes" : "no",
772		   iface->csa_in_progress ? "yes" : "no");
773
774	/* Check if CSA in progress */
775	if (iface->csa_in_progress)
776		return 0;
777
778	/* Check if active CAC */
779	if (iface->cac_started)
780		return hostapd_dfs_start_channel_switch_cac(iface);
781
782	/* Perform channel switch/CSA */
783	channel = dfs_get_valid_channel(iface, &secondary_channel,
784					&vht_oper_centr_freq_seg0_idx,
785					&vht_oper_centr_freq_seg1_idx,
786					skip_radar);
787
788	if (!channel) {
789		/*
790		 * If there is no channel to switch immediately to, check if
791		 * there is another channel where we can switch even if it
792		 * requires to perform a CAC first.
793		 */
794		skip_radar = 0;
795		channel = dfs_get_valid_channel(iface, &secondary_channel,
796						&vht_oper_centr_freq_seg0_idx,
797						&vht_oper_centr_freq_seg1_idx,
798						skip_radar);
799		if (!channel) {
800			/* FIXME: Wait for channel(s) to become available */
801			hostapd_disable_iface(iface);
802			return err;
803		}
804
805		iface->freq = channel->freq;
806		iface->conf->channel = channel->chan;
807		iface->conf->secondary_channel = secondary_channel;
808		iface->conf->vht_oper_centr_freq_seg0_idx =
809			vht_oper_centr_freq_seg0_idx;
810		iface->conf->vht_oper_centr_freq_seg1_idx =
811			vht_oper_centr_freq_seg1_idx;
812
813		hostapd_disable_iface(iface);
814		hostapd_enable_iface(iface);
815		return 0;
816	}
817
818	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
819		   channel->chan);
820	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
821		"freq=%d chan=%d sec_chan=%d", channel->freq,
822		channel->chan, secondary_channel);
823
824	/* Setup CSA request */
825	os_memset(&csa_settings, 0, sizeof(csa_settings));
826	csa_settings.cs_count = 5;
827	csa_settings.block_tx = 1;
828	err = hostapd_set_freq_params(&csa_settings.freq_params,
829				      iface->conf->hw_mode,
830				      channel->freq,
831				      channel->chan,
832				      iface->conf->ieee80211n,
833				      iface->conf->ieee80211ac,
834				      secondary_channel,
835				      iface->conf->vht_oper_chwidth,
836				      vht_oper_centr_freq_seg0_idx,
837				      vht_oper_centr_freq_seg1_idx,
838				      iface->current_mode->vht_capab);
839
840	if (err) {
841		wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
842		hostapd_disable_iface(iface);
843		return err;
844	}
845
846	err = hostapd_switch_channel(hapd, &csa_settings);
847	if (err) {
848		wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
849			   err);
850		iface->freq = channel->freq;
851		iface->conf->channel = channel->chan;
852		iface->conf->secondary_channel = secondary_channel;
853		iface->conf->vht_oper_centr_freq_seg0_idx =
854			vht_oper_centr_freq_seg0_idx;
855		iface->conf->vht_oper_centr_freq_seg1_idx =
856			vht_oper_centr_freq_seg1_idx;
857
858		hostapd_disable_iface(iface);
859		hostapd_enable_iface(iface);
860		return 0;
861	}
862
863	/* Channel configuration will be updated once CSA completes and
864	 * ch_switch_notify event is received */
865
866	wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
867	return 0;
868}
869
870
871int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
872			       int ht_enabled, int chan_offset, int chan_width,
873			       int cf1, int cf2)
874{
875	int res;
876
877	if (!iface->conf->ieee80211h)
878		return 0;
879
880	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
881		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
882		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
883
884	/* mark radar frequency as invalid */
885	res = set_dfs_state(iface, freq, ht_enabled, chan_offset,
886			    chan_width, cf1, cf2,
887			    HOSTAPD_CHAN_DFS_UNAVAILABLE);
888
889	/* Skip if reported radar event not overlapped our channels */
890	res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
891	if (!res)
892		return 0;
893
894	/* radar detected while operating, switch the channel. */
895	res = hostapd_dfs_start_channel_switch(iface);
896
897	return res;
898}
899
900
901int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
902			     int ht_enabled, int chan_offset, int chan_width,
903			     int cf1, int cf2)
904{
905	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
906		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
907		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
908	/* TODO add correct implementation here */
909	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
910		      cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
911	return 0;
912}
913
914
915int hostapd_is_dfs_required(struct hostapd_iface *iface)
916{
917	int n_chans, start_chan_idx;
918
919	if (!iface->current_mode)
920		return -1;
921
922	/* Get start (first) channel for current configuration */
923	start_chan_idx = dfs_get_start_chan_idx(iface);
924	if (start_chan_idx == -1)
925		return -1;
926
927	/* Get number of used channels, depend on width */
928	n_chans = dfs_get_used_n_chans(iface);
929
930	/* Check if any of configured channels require DFS */
931	return dfs_check_chans_radar(iface, start_chan_idx, n_chans);
932}
933