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, int *seg1)
22{
23	int n_chans = 1;
24
25	*seg1 = 0;
26
27	if (iface->conf->ieee80211n && iface->conf->secondary_channel)
28		n_chans = 2;
29
30	if (iface->conf->ieee80211ac) {
31		switch (iface->conf->vht_oper_chwidth) {
32		case VHT_CHANWIDTH_USE_HT:
33			break;
34		case VHT_CHANWIDTH_80MHZ:
35			n_chans = 4;
36			break;
37		case VHT_CHANWIDTH_160MHZ:
38			n_chans = 8;
39			break;
40		case VHT_CHANWIDTH_80P80MHZ:
41			n_chans = 4;
42			*seg1 = 4;
43			break;
44		default:
45			break;
46		}
47	}
48
49	return n_chans;
50}
51
52
53static int dfs_channel_available(struct hostapd_channel_data *chan,
54				 int skip_radar)
55{
56	/*
57	 * When radar detection happens, CSA is performed. However, there's no
58	 * time for CAC, so radar channels must be skipped when finding a new
59	 * channel for CSA, unless they are available for immediate use.
60	 */
61	if (skip_radar && (chan->flag & HOSTAPD_CHAN_RADAR) &&
62	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) !=
63	     HOSTAPD_CHAN_DFS_AVAILABLE))
64		return 0;
65
66	if (chan->flag & HOSTAPD_CHAN_DISABLED)
67		return 0;
68	if ((chan->flag & HOSTAPD_CHAN_RADAR) &&
69	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) ==
70	     HOSTAPD_CHAN_DFS_UNAVAILABLE))
71		return 0;
72	return 1;
73}
74
75
76static int dfs_is_chan_allowed(struct hostapd_channel_data *chan, int n_chans)
77{
78	/*
79	 * The tables contain first valid channel number based on channel width.
80	 * We will also choose this first channel as the control one.
81	 */
82	int allowed_40[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
83			     184, 192 };
84	/*
85	 * VHT80, valid channels based on center frequency:
86	 * 42, 58, 106, 122, 138, 155
87	 */
88	int allowed_80[] = { 36, 52, 100, 116, 132, 149 };
89	/*
90	 * VHT160 valid channels based on center frequency:
91	 * 50, 114
92	 */
93	int allowed_160[] = { 36, 100 };
94	int *allowed = allowed_40;
95	unsigned int i, allowed_no = 0;
96
97	switch (n_chans) {
98	case 2:
99		allowed = allowed_40;
100		allowed_no = ARRAY_SIZE(allowed_40);
101		break;
102	case 4:
103		allowed = allowed_80;
104		allowed_no = ARRAY_SIZE(allowed_80);
105		break;
106	case 8:
107		allowed = allowed_160;
108		allowed_no = ARRAY_SIZE(allowed_160);
109		break;
110	default:
111		wpa_printf(MSG_DEBUG, "Unknown width for %d channels", n_chans);
112		break;
113	}
114
115	for (i = 0; i < allowed_no; i++) {
116		if (chan->chan == allowed[i])
117			return 1;
118	}
119
120	return 0;
121}
122
123
124static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
125				    int first_chan_idx, int num_chans,
126				    int skip_radar)
127{
128	struct hostapd_channel_data *first_chan, *chan;
129	int i;
130
131	if (first_chan_idx + num_chans >= mode->num_channels)
132		return 0;
133
134	first_chan = &mode->channels[first_chan_idx];
135
136	for (i = 0; i < num_chans; i++) {
137		chan = &mode->channels[first_chan_idx + i];
138
139		if (first_chan->freq + i * 20 != chan->freq)
140			return 0;
141
142		if (!dfs_channel_available(chan, skip_radar))
143			return 0;
144	}
145
146	return 1;
147}
148
149
150static int is_in_chanlist(struct hostapd_iface *iface,
151			  struct hostapd_channel_data *chan)
152{
153	int *entry;
154
155	if (!iface->conf->chanlist)
156		return 1;
157
158	for (entry = iface->conf->chanlist; *entry != -1; entry++) {
159		if (*entry == chan->chan)
160			return 1;
161	}
162	return 0;
163}
164
165
166/*
167 * The function assumes HT40+ operation.
168 * Make sure to adjust the following variables after calling this:
169 *  - hapd->secondary_channel
170 *  - hapd->vht_oper_centr_freq_seg0_idx
171 *  - hapd->vht_oper_centr_freq_seg1_idx
172 */
173static int dfs_find_channel(struct hostapd_iface *iface,
174			    struct hostapd_channel_data **ret_chan,
175			    int idx, int skip_radar)
176{
177	struct hostapd_hw_modes *mode;
178	struct hostapd_channel_data *chan;
179	int i, channel_idx = 0, n_chans, n_chans1;
180
181	mode = iface->current_mode;
182	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
183
184	wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
185	for (i = 0; i < mode->num_channels; i++) {
186		chan = &mode->channels[i];
187
188		/* Skip HT40/VHT incompatible channels */
189		if (iface->conf->ieee80211n &&
190		    iface->conf->secondary_channel &&
191		    !dfs_is_chan_allowed(chan, n_chans))
192			continue;
193
194		/* Skip incompatible chandefs */
195		if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
196			continue;
197
198		if (!is_in_chanlist(iface, chan))
199			continue;
200
201		if (ret_chan && idx == channel_idx) {
202			wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
203			*ret_chan = chan;
204			return idx;
205		}
206		wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
207		channel_idx++;
208	}
209	return channel_idx;
210}
211
212
213static void dfs_adjust_vht_center_freq(struct hostapd_iface *iface,
214				       struct hostapd_channel_data *chan,
215				       int secondary_channel,
216				       u8 *vht_oper_centr_freq_seg0_idx,
217				       u8 *vht_oper_centr_freq_seg1_idx)
218{
219	if (!iface->conf->ieee80211ac)
220		return;
221
222	if (!chan)
223		return;
224
225	*vht_oper_centr_freq_seg1_idx = 0;
226
227	switch (iface->conf->vht_oper_chwidth) {
228	case VHT_CHANWIDTH_USE_HT:
229		if (secondary_channel == 1)
230			*vht_oper_centr_freq_seg0_idx = chan->chan + 2;
231		else if (secondary_channel == -1)
232			*vht_oper_centr_freq_seg0_idx = chan->chan - 2;
233		else
234			*vht_oper_centr_freq_seg0_idx = chan->chan;
235		break;
236	case VHT_CHANWIDTH_80MHZ:
237		*vht_oper_centr_freq_seg0_idx = chan->chan + 6;
238		break;
239	case VHT_CHANWIDTH_160MHZ:
240		*vht_oper_centr_freq_seg0_idx = chan->chan + 14;
241		break;
242	default:
243		wpa_printf(MSG_INFO, "DFS only VHT20/40/80/160 is supported now");
244		*vht_oper_centr_freq_seg0_idx = 0;
245		break;
246	}
247
248	wpa_printf(MSG_DEBUG, "DFS adjusting VHT center frequency: %d, %d",
249		   *vht_oper_centr_freq_seg0_idx,
250		   *vht_oper_centr_freq_seg1_idx);
251}
252
253
254/* Return start channel idx we will use for mode->channels[idx] */
255static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start)
256{
257	struct hostapd_hw_modes *mode;
258	struct hostapd_channel_data *chan;
259	int channel_no = iface->conf->channel;
260	int res = -1, i;
261	int chan_seg1 = -1;
262
263	*seg1_start = -1;
264
265	/* HT40- */
266	if (iface->conf->ieee80211n && iface->conf->secondary_channel == -1)
267		channel_no -= 4;
268
269	/* VHT */
270	if (iface->conf->ieee80211ac) {
271		switch (iface->conf->vht_oper_chwidth) {
272		case VHT_CHANWIDTH_USE_HT:
273			break;
274		case VHT_CHANWIDTH_80MHZ:
275			channel_no =
276				iface->conf->vht_oper_centr_freq_seg0_idx - 6;
277			break;
278		case VHT_CHANWIDTH_160MHZ:
279			channel_no =
280				iface->conf->vht_oper_centr_freq_seg0_idx - 14;
281			break;
282		case VHT_CHANWIDTH_80P80MHZ:
283			channel_no =
284				iface->conf->vht_oper_centr_freq_seg0_idx - 6;
285			chan_seg1 =
286				iface->conf->vht_oper_centr_freq_seg1_idx - 6;
287			break;
288		default:
289			wpa_printf(MSG_INFO,
290				   "DFS only VHT20/40/80/160/80+80 is supported now");
291			channel_no = -1;
292			break;
293		}
294	}
295
296	/* Get idx */
297	mode = iface->current_mode;
298	for (i = 0; i < mode->num_channels; i++) {
299		chan = &mode->channels[i];
300		if (chan->chan == channel_no) {
301			res = i;
302			break;
303		}
304	}
305
306	if (res != -1 && chan_seg1 > -1) {
307		int found = 0;
308
309		/* Get idx for seg1 */
310		mode = iface->current_mode;
311		for (i = 0; i < mode->num_channels; i++) {
312			chan = &mode->channels[i];
313			if (chan->chan == chan_seg1) {
314				*seg1_start = i;
315				found = 1;
316				break;
317			}
318		}
319		if (!found)
320			res = -1;
321	}
322
323	if (res == -1) {
324		wpa_printf(MSG_DEBUG,
325			   "DFS chan_idx seems wrong; num-ch: %d ch-no: %d conf-ch-no: %d 11n: %d sec-ch: %d vht-oper-width: %d",
326			   mode->num_channels, channel_no, iface->conf->channel,
327			   iface->conf->ieee80211n,
328			   iface->conf->secondary_channel,
329			   iface->conf->vht_oper_chwidth);
330
331		for (i = 0; i < mode->num_channels; i++) {
332			wpa_printf(MSG_DEBUG, "Available channel: %d",
333				   mode->channels[i].chan);
334		}
335	}
336
337	return res;
338}
339
340
341/* At least one channel have radar flag */
342static int dfs_check_chans_radar(struct hostapd_iface *iface,
343				 int start_chan_idx, int n_chans)
344{
345	struct hostapd_channel_data *channel;
346	struct hostapd_hw_modes *mode;
347	int i, res = 0;
348
349	mode = iface->current_mode;
350
351	for (i = 0; i < n_chans; i++) {
352		channel = &mode->channels[start_chan_idx + i];
353		if (channel->flag & HOSTAPD_CHAN_RADAR)
354			res++;
355	}
356
357	return res;
358}
359
360
361/* All channels available */
362static int dfs_check_chans_available(struct hostapd_iface *iface,
363				     int start_chan_idx, int n_chans)
364{
365	struct hostapd_channel_data *channel;
366	struct hostapd_hw_modes *mode;
367	int i;
368
369	mode = iface->current_mode;
370
371	for (i = 0; i < n_chans; i++) {
372		channel = &mode->channels[start_chan_idx + i];
373
374		if (channel->flag & HOSTAPD_CHAN_DISABLED)
375			break;
376
377		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
378			continue;
379
380		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) !=
381		    HOSTAPD_CHAN_DFS_AVAILABLE)
382			break;
383	}
384
385	return i == n_chans;
386}
387
388
389/* At least one channel unavailable */
390static int dfs_check_chans_unavailable(struct hostapd_iface *iface,
391				       int start_chan_idx,
392				       int n_chans)
393{
394	struct hostapd_channel_data *channel;
395	struct hostapd_hw_modes *mode;
396	int i, res = 0;
397
398	mode = iface->current_mode;
399
400	for (i = 0; i < n_chans; i++) {
401		channel = &mode->channels[start_chan_idx + i];
402		if (channel->flag & HOSTAPD_CHAN_DISABLED)
403			res++;
404		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) ==
405		    HOSTAPD_CHAN_DFS_UNAVAILABLE)
406			res++;
407	}
408
409	return res;
410}
411
412
413static struct hostapd_channel_data *
414dfs_get_valid_channel(struct hostapd_iface *iface,
415		      int *secondary_channel,
416		      u8 *vht_oper_centr_freq_seg0_idx,
417		      u8 *vht_oper_centr_freq_seg1_idx,
418		      int skip_radar)
419{
420	struct hostapd_hw_modes *mode;
421	struct hostapd_channel_data *chan = NULL;
422	int num_available_chandefs;
423	int chan_idx;
424	u32 _rand;
425
426	wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
427	*secondary_channel = 0;
428	*vht_oper_centr_freq_seg0_idx = 0;
429	*vht_oper_centr_freq_seg1_idx = 0;
430
431	if (iface->current_mode == NULL)
432		return NULL;
433
434	mode = iface->current_mode;
435	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
436		return NULL;
437
438	/* Get the count first */
439	num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
440	if (num_available_chandefs == 0)
441		return NULL;
442
443	os_get_random((u8 *) &_rand, sizeof(_rand));
444	chan_idx = _rand % num_available_chandefs;
445	dfs_find_channel(iface, &chan, chan_idx, skip_radar);
446
447	/* dfs_find_channel() calculations assume HT40+ */
448	if (iface->conf->secondary_channel)
449		*secondary_channel = 1;
450	else
451		*secondary_channel = 0;
452
453	dfs_adjust_vht_center_freq(iface, chan,
454				   *secondary_channel,
455				   vht_oper_centr_freq_seg0_idx,
456				   vht_oper_centr_freq_seg1_idx);
457
458	return chan;
459}
460
461
462static int set_dfs_state_freq(struct hostapd_iface *iface, int freq, u32 state)
463{
464	struct hostapd_hw_modes *mode;
465	struct hostapd_channel_data *chan = NULL;
466	int i;
467
468	mode = iface->current_mode;
469	if (mode == NULL)
470		return 0;
471
472	wpa_printf(MSG_DEBUG, "set_dfs_state 0x%X for %d MHz", state, freq);
473	for (i = 0; i < iface->current_mode->num_channels; i++) {
474		chan = &iface->current_mode->channels[i];
475		if (chan->freq == freq) {
476			if (chan->flag & HOSTAPD_CHAN_RADAR) {
477				chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
478				chan->flag |= state;
479				return 1; /* Channel found */
480			}
481		}
482	}
483	wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
484	return 0;
485}
486
487
488static int set_dfs_state(struct hostapd_iface *iface, int freq, int ht_enabled,
489			 int chan_offset, int chan_width, int cf1,
490			 int cf2, u32 state)
491{
492	int n_chans = 1, i;
493	struct hostapd_hw_modes *mode;
494	int frequency = freq;
495	int ret = 0;
496
497	mode = iface->current_mode;
498	if (mode == NULL)
499		return 0;
500
501	if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
502		wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
503		return 0;
504	}
505
506	/* Seems cf1 and chan_width is enough here */
507	switch (chan_width) {
508	case CHAN_WIDTH_20_NOHT:
509	case CHAN_WIDTH_20:
510		n_chans = 1;
511		if (frequency == 0)
512			frequency = cf1;
513		break;
514	case CHAN_WIDTH_40:
515		n_chans = 2;
516		frequency = cf1 - 10;
517		break;
518	case CHAN_WIDTH_80:
519		n_chans = 4;
520		frequency = cf1 - 30;
521		break;
522	case CHAN_WIDTH_160:
523		n_chans = 8;
524		frequency = cf1 - 70;
525		break;
526	default:
527		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
528			   chan_width);
529		break;
530	}
531
532	wpa_printf(MSG_DEBUG, "DFS freq: %dMHz, n_chans: %d", frequency,
533		   n_chans);
534	for (i = 0; i < n_chans; i++) {
535		ret += set_dfs_state_freq(iface, frequency, state);
536		frequency = frequency + 20;
537	}
538
539	return ret;
540}
541
542
543static int dfs_are_channels_overlapped(struct hostapd_iface *iface, int freq,
544				       int chan_width, int cf1, int cf2)
545{
546	int start_chan_idx, start_chan_idx1;
547	struct hostapd_hw_modes *mode;
548	struct hostapd_channel_data *chan;
549	int n_chans, n_chans1, i, j, frequency = freq, radar_n_chans = 1;
550	u8 radar_chan;
551	int res = 0;
552
553	/* Our configuration */
554	mode = iface->current_mode;
555	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
556	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
557
558	/* Check we are on DFS channel(s) */
559	if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
560		return 0;
561
562	/* Reported via radar event */
563	switch (chan_width) {
564	case CHAN_WIDTH_20_NOHT:
565	case CHAN_WIDTH_20:
566		radar_n_chans = 1;
567		if (frequency == 0)
568			frequency = cf1;
569		break;
570	case CHAN_WIDTH_40:
571		radar_n_chans = 2;
572		frequency = cf1 - 10;
573		break;
574	case CHAN_WIDTH_80:
575		radar_n_chans = 4;
576		frequency = cf1 - 30;
577		break;
578	case CHAN_WIDTH_160:
579		radar_n_chans = 8;
580		frequency = cf1 - 70;
581		break;
582	default:
583		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
584			   chan_width);
585		break;
586	}
587
588	ieee80211_freq_to_chan(frequency, &radar_chan);
589
590	for (i = 0; i < n_chans; i++) {
591		chan = &mode->channels[start_chan_idx + i];
592		if (!(chan->flag & HOSTAPD_CHAN_RADAR))
593			continue;
594		for (j = 0; j < radar_n_chans; j++) {
595			wpa_printf(MSG_DEBUG, "checking our: %d, radar: %d",
596				   chan->chan, radar_chan + j * 4);
597			if (chan->chan == radar_chan + j * 4)
598				res++;
599		}
600	}
601
602	wpa_printf(MSG_DEBUG, "overlapped: %d", res);
603
604	return res;
605}
606
607
608static unsigned int dfs_get_cac_time(struct hostapd_iface *iface,
609				     int start_chan_idx, int n_chans)
610{
611	struct hostapd_channel_data *channel;
612	struct hostapd_hw_modes *mode;
613	int i;
614	unsigned int cac_time_ms = 0;
615
616	mode = iface->current_mode;
617
618	for (i = 0; i < n_chans; i++) {
619		channel = &mode->channels[start_chan_idx + i];
620		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
621			continue;
622		if (channel->dfs_cac_ms > cac_time_ms)
623			cac_time_ms = channel->dfs_cac_ms;
624	}
625
626	return cac_time_ms;
627}
628
629
630/*
631 * Main DFS handler
632 * 1 - continue channel/ap setup
633 * 0 - channel/ap setup will be continued after CAC
634 * -1 - hit critical error
635 */
636int hostapd_handle_dfs(struct hostapd_iface *iface)
637{
638	struct hostapd_channel_data *channel;
639	int res, n_chans, n_chans1, start_chan_idx, start_chan_idx1;
640	int skip_radar = 0;
641
642	iface->cac_started = 0;
643
644	do {
645		/* Get start (first) channel for current configuration */
646		start_chan_idx = dfs_get_start_chan_idx(iface,
647							&start_chan_idx1);
648		if (start_chan_idx == -1)
649			return -1;
650
651		/* Get number of used channels, depend on width */
652		n_chans = dfs_get_used_n_chans(iface, &n_chans1);
653
654		/* Setup CAC time */
655		iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
656						     n_chans);
657
658		/* Check if any of configured channels require DFS */
659		res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
660		wpa_printf(MSG_DEBUG,
661			   "DFS %d channels required radar detection",
662			   res);
663		if (!res)
664			return 1;
665
666		/* Check if all channels are DFS available */
667		res = dfs_check_chans_available(iface, start_chan_idx, n_chans);
668		wpa_printf(MSG_DEBUG,
669			   "DFS all channels available, (SKIP CAC): %s",
670			   res ? "yes" : "no");
671		if (res)
672			return 1;
673
674		/* Check if any of configured channels is unavailable */
675		res = dfs_check_chans_unavailable(iface, start_chan_idx,
676						  n_chans);
677		wpa_printf(MSG_DEBUG, "DFS %d chans unavailable - choose other channel: %s",
678			   res, res ? "yes": "no");
679		if (res) {
680			int sec = 0;
681			u8 cf1 = 0, cf2 = 0;
682
683			channel = dfs_get_valid_channel(iface, &sec, &cf1, &cf2,
684							skip_radar);
685			if (!channel) {
686				wpa_printf(MSG_ERROR, "could not get valid channel");
687				return -1;
688			}
689
690			iface->freq = channel->freq;
691			iface->conf->channel = channel->chan;
692			iface->conf->secondary_channel = sec;
693			iface->conf->vht_oper_centr_freq_seg0_idx = cf1;
694			iface->conf->vht_oper_centr_freq_seg1_idx = cf2;
695		}
696	} while (res);
697
698	/* Finally start CAC */
699	hostapd_set_state(iface, HAPD_IFACE_DFS);
700	wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz", iface->freq);
701	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
702		"freq=%d chan=%d sec_chan=%d, width=%d, seg0=%d, seg1=%d, cac_time=%ds",
703		iface->freq,
704		iface->conf->channel, iface->conf->secondary_channel,
705		iface->conf->vht_oper_chwidth,
706		iface->conf->vht_oper_centr_freq_seg0_idx,
707		iface->conf->vht_oper_centr_freq_seg1_idx,
708		iface->dfs_cac_ms / 1000);
709
710	res = hostapd_start_dfs_cac(iface, iface->conf->hw_mode,
711				    iface->freq,
712				    iface->conf->channel,
713				    iface->conf->ieee80211n,
714				    iface->conf->ieee80211ac,
715				    iface->conf->secondary_channel,
716				    iface->conf->vht_oper_chwidth,
717				    iface->conf->vht_oper_centr_freq_seg0_idx,
718				    iface->conf->vht_oper_centr_freq_seg1_idx);
719
720	if (res) {
721		wpa_printf(MSG_ERROR, "DFS start_dfs_cac() failed, %d", res);
722		return -1;
723	}
724
725	return 0;
726}
727
728
729int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
730			     int ht_enabled, int chan_offset, int chan_width,
731			     int cf1, int cf2)
732{
733	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
734		"success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
735		success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
736
737	if (success) {
738		/* Complete iface/ap configuration */
739		set_dfs_state(iface, freq, ht_enabled, chan_offset,
740			      chan_width, cf1, cf2,
741			      HOSTAPD_CHAN_DFS_AVAILABLE);
742		iface->cac_started = 0;
743		hostapd_setup_interface_complete(iface, 0);
744	}
745
746	return 0;
747}
748
749
750static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
751{
752	struct hostapd_channel_data *channel;
753	int secondary_channel;
754	u8 vht_oper_centr_freq_seg0_idx = 0;
755	u8 vht_oper_centr_freq_seg1_idx = 0;
756	int skip_radar = 0;
757	int err = 1;
758
759	/* Radar detected during active CAC */
760	iface->cac_started = 0;
761	channel = dfs_get_valid_channel(iface, &secondary_channel,
762					&vht_oper_centr_freq_seg0_idx,
763					&vht_oper_centr_freq_seg1_idx,
764					skip_radar);
765
766	if (!channel) {
767		wpa_printf(MSG_ERROR, "No valid channel available");
768		hostapd_setup_interface_complete(iface, err);
769		return err;
770	}
771
772	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
773		   channel->chan);
774	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
775		"freq=%d chan=%d sec_chan=%d", channel->freq,
776		channel->chan, secondary_channel);
777
778	iface->freq = channel->freq;
779	iface->conf->channel = channel->chan;
780	iface->conf->secondary_channel = secondary_channel;
781	iface->conf->vht_oper_centr_freq_seg0_idx =
782		vht_oper_centr_freq_seg0_idx;
783	iface->conf->vht_oper_centr_freq_seg1_idx =
784		vht_oper_centr_freq_seg1_idx;
785	err = 0;
786
787	hostapd_setup_interface_complete(iface, err);
788	return err;
789}
790
791
792static int hostapd_csa_in_progress(struct hostapd_iface *iface)
793{
794	unsigned int i;
795	for (i = 0; i < iface->num_bss; i++)
796		if (iface->bss[i]->csa_in_progress)
797			return 1;
798	return 0;
799}
800
801
802static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
803{
804	struct hostapd_channel_data *channel;
805	int secondary_channel;
806	u8 vht_oper_centr_freq_seg0_idx;
807	u8 vht_oper_centr_freq_seg1_idx;
808	int skip_radar = 1;
809	struct csa_settings csa_settings;
810	unsigned int i;
811	int err = 1;
812
813	wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
814		   __func__, iface->cac_started ? "yes" : "no",
815		   hostapd_csa_in_progress(iface) ? "yes" : "no");
816
817	/* Check if CSA in progress */
818	if (hostapd_csa_in_progress(iface))
819		return 0;
820
821	/* Check if active CAC */
822	if (iface->cac_started)
823		return hostapd_dfs_start_channel_switch_cac(iface);
824
825	/* Perform channel switch/CSA */
826	channel = dfs_get_valid_channel(iface, &secondary_channel,
827					&vht_oper_centr_freq_seg0_idx,
828					&vht_oper_centr_freq_seg1_idx,
829					skip_radar);
830
831	if (!channel) {
832		/*
833		 * If there is no channel to switch immediately to, check if
834		 * there is another channel where we can switch even if it
835		 * requires to perform a CAC first.
836		 */
837		skip_radar = 0;
838		channel = dfs_get_valid_channel(iface, &secondary_channel,
839						&vht_oper_centr_freq_seg0_idx,
840						&vht_oper_centr_freq_seg1_idx,
841						skip_radar);
842		if (!channel) {
843			/* FIXME: Wait for channel(s) to become available */
844			hostapd_disable_iface(iface);
845			return err;
846		}
847
848		iface->freq = channel->freq;
849		iface->conf->channel = channel->chan;
850		iface->conf->secondary_channel = secondary_channel;
851		iface->conf->vht_oper_centr_freq_seg0_idx =
852			vht_oper_centr_freq_seg0_idx;
853		iface->conf->vht_oper_centr_freq_seg1_idx =
854			vht_oper_centr_freq_seg1_idx;
855
856		hostapd_disable_iface(iface);
857		hostapd_enable_iface(iface);
858		return 0;
859	}
860
861	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
862		   channel->chan);
863	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
864		"freq=%d chan=%d sec_chan=%d", channel->freq,
865		channel->chan, secondary_channel);
866
867	/* Setup CSA request */
868	os_memset(&csa_settings, 0, sizeof(csa_settings));
869	csa_settings.cs_count = 5;
870	csa_settings.block_tx = 1;
871	err = hostapd_set_freq_params(&csa_settings.freq_params,
872				      iface->conf->hw_mode,
873				      channel->freq,
874				      channel->chan,
875				      iface->conf->ieee80211n,
876				      iface->conf->ieee80211ac,
877				      secondary_channel,
878				      iface->conf->vht_oper_chwidth,
879				      vht_oper_centr_freq_seg0_idx,
880				      vht_oper_centr_freq_seg1_idx,
881				      iface->current_mode->vht_capab);
882
883	if (err) {
884		wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
885		hostapd_disable_iface(iface);
886		return err;
887	}
888
889	for (i = 0; i < iface->num_bss; i++) {
890		err = hostapd_switch_channel(iface->bss[i], &csa_settings);
891		if (err)
892			break;
893	}
894
895	if (err) {
896		wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
897			   err);
898		iface->freq = channel->freq;
899		iface->conf->channel = channel->chan;
900		iface->conf->secondary_channel = secondary_channel;
901		iface->conf->vht_oper_centr_freq_seg0_idx =
902			vht_oper_centr_freq_seg0_idx;
903		iface->conf->vht_oper_centr_freq_seg1_idx =
904			vht_oper_centr_freq_seg1_idx;
905
906		hostapd_disable_iface(iface);
907		hostapd_enable_iface(iface);
908		return 0;
909	}
910
911	/* Channel configuration will be updated once CSA completes and
912	 * ch_switch_notify event is received */
913
914	wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
915	return 0;
916}
917
918
919int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
920			       int ht_enabled, int chan_offset, int chan_width,
921			       int cf1, int cf2)
922{
923	int res;
924
925	if (!iface->conf->ieee80211h)
926		return 0;
927
928	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
929		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
930		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
931
932	/* mark radar frequency as invalid */
933	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
934		      cf1, cf2, HOSTAPD_CHAN_DFS_UNAVAILABLE);
935
936	/* Skip if reported radar event not overlapped our channels */
937	res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
938	if (!res)
939		return 0;
940
941	/* radar detected while operating, switch the channel. */
942	res = hostapd_dfs_start_channel_switch(iface);
943
944	return res;
945}
946
947
948int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
949			     int ht_enabled, int chan_offset, int chan_width,
950			     int cf1, int cf2)
951{
952	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
953		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
954		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
955	/* TODO add correct implementation here */
956	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
957		      cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
958	return 0;
959}
960
961
962int hostapd_is_dfs_required(struct hostapd_iface *iface)
963{
964	int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
965
966	if (!iface->conf->ieee80211h || !iface->current_mode ||
967	    iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
968		return 0;
969
970	/* Get start (first) channel for current configuration */
971	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
972	if (start_chan_idx == -1)
973		return -1;
974
975	/* Get number of used channels, depend on width */
976	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
977
978	/* Check if any of configured channels require DFS */
979	res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
980	if (res)
981		return res;
982	if (start_chan_idx1 >= 0 && n_chans1 > 0)
983		res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
984	return res;
985}
986