1/*
2 * DFS - Dynamic Frequency Selection
3 * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
4 * Copyright (c) 2013-2017, 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/hw_features_common.h"
15#include "common/wpa_ctrl.h"
16#include "hostapd.h"
17#include "ap_drv_ops.h"
18#include "drivers/driver.h"
19#include "dfs.h"
20
21
22static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1)
23{
24	int n_chans = 1;
25
26	*seg1 = 0;
27
28	if (iface->conf->ieee80211n && iface->conf->secondary_channel)
29		n_chans = 2;
30
31	if (iface->conf->ieee80211ac) {
32		switch (iface->conf->vht_oper_chwidth) {
33		case VHT_CHANWIDTH_USE_HT:
34			break;
35		case VHT_CHANWIDTH_80MHZ:
36			n_chans = 4;
37			break;
38		case VHT_CHANWIDTH_160MHZ:
39			n_chans = 8;
40			break;
41		case VHT_CHANWIDTH_80P80MHZ:
42			n_chans = 4;
43			*seg1 = 4;
44			break;
45		default:
46			break;
47		}
48	}
49
50	return n_chans;
51}
52
53
54static int dfs_channel_available(struct hostapd_channel_data *chan,
55				 int skip_radar)
56{
57	/*
58	 * When radar detection happens, CSA is performed. However, there's no
59	 * time for CAC, so radar channels must be skipped when finding a new
60	 * channel for CSA, unless they are available for immediate use.
61	 */
62	if (skip_radar && (chan->flag & HOSTAPD_CHAN_RADAR) &&
63	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) !=
64	     HOSTAPD_CHAN_DFS_AVAILABLE))
65		return 0;
66
67	if (chan->flag & HOSTAPD_CHAN_DISABLED)
68		return 0;
69	if ((chan->flag & HOSTAPD_CHAN_RADAR) &&
70	    ((chan->flag & HOSTAPD_CHAN_DFS_MASK) ==
71	     HOSTAPD_CHAN_DFS_UNAVAILABLE))
72		return 0;
73	return 1;
74}
75
76
77static int dfs_is_chan_allowed(struct hostapd_channel_data *chan, int n_chans)
78{
79	/*
80	 * The tables contain first valid channel number based on channel width.
81	 * We will also choose this first channel as the control one.
82	 */
83	int allowed_40[] = { 36, 44, 52, 60, 100, 108, 116, 124, 132, 149, 157,
84			     184, 192 };
85	/*
86	 * VHT80, valid channels based on center frequency:
87	 * 42, 58, 106, 122, 138, 155
88	 */
89	int allowed_80[] = { 36, 52, 100, 116, 132, 149 };
90	/*
91	 * VHT160 valid channels based on center frequency:
92	 * 50, 114
93	 */
94	int allowed_160[] = { 36, 100 };
95	int *allowed = allowed_40;
96	unsigned int i, allowed_no = 0;
97
98	switch (n_chans) {
99	case 2:
100		allowed = allowed_40;
101		allowed_no = ARRAY_SIZE(allowed_40);
102		break;
103	case 4:
104		allowed = allowed_80;
105		allowed_no = ARRAY_SIZE(allowed_80);
106		break;
107	case 8:
108		allowed = allowed_160;
109		allowed_no = ARRAY_SIZE(allowed_160);
110		break;
111	default:
112		wpa_printf(MSG_DEBUG, "Unknown width for %d channels", n_chans);
113		break;
114	}
115
116	for (i = 0; i < allowed_no; i++) {
117		if (chan->chan == allowed[i])
118			return 1;
119	}
120
121	return 0;
122}
123
124
125static struct hostapd_channel_data *
126dfs_get_chan_data(struct hostapd_hw_modes *mode, int freq, int first_chan_idx)
127{
128	int i;
129
130	for (i = first_chan_idx; i < mode->num_channels; i++) {
131		if (mode->channels[i].freq == freq)
132			return &mode->channels[i];
133	}
134
135	return NULL;
136}
137
138
139static int dfs_chan_range_available(struct hostapd_hw_modes *mode,
140				    int first_chan_idx, int num_chans,
141				    int skip_radar)
142{
143	struct hostapd_channel_data *first_chan, *chan;
144	int i;
145
146	if (first_chan_idx + num_chans > mode->num_channels)
147		return 0;
148
149	first_chan = &mode->channels[first_chan_idx];
150
151	for (i = 0; i < num_chans; i++) {
152		chan = dfs_get_chan_data(mode, first_chan->freq + i * 20,
153					 first_chan_idx);
154		if (!chan)
155			return 0;
156
157		if (!dfs_channel_available(chan, skip_radar))
158			return 0;
159	}
160
161	return 1;
162}
163
164
165static int is_in_chanlist(struct hostapd_iface *iface,
166			  struct hostapd_channel_data *chan)
167{
168	if (!iface->conf->acs_ch_list.num)
169		return 1;
170
171	return freq_range_list_includes(&iface->conf->acs_ch_list, chan->chan);
172}
173
174
175/*
176 * The function assumes HT40+ operation.
177 * Make sure to adjust the following variables after calling this:
178 *  - hapd->secondary_channel
179 *  - hapd->vht_oper_centr_freq_seg0_idx
180 *  - hapd->vht_oper_centr_freq_seg1_idx
181 */
182static int dfs_find_channel(struct hostapd_iface *iface,
183			    struct hostapd_channel_data **ret_chan,
184			    int idx, int skip_radar)
185{
186	struct hostapd_hw_modes *mode;
187	struct hostapd_channel_data *chan;
188	int i, channel_idx = 0, n_chans, n_chans1;
189
190	mode = iface->current_mode;
191	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
192
193	wpa_printf(MSG_DEBUG, "DFS new chan checking %d channels", n_chans);
194	for (i = 0; i < mode->num_channels; i++) {
195		chan = &mode->channels[i];
196
197		/* Skip HT40/VHT incompatible channels */
198		if (iface->conf->ieee80211n &&
199		    iface->conf->secondary_channel &&
200		    !dfs_is_chan_allowed(chan, n_chans))
201			continue;
202
203		/* Skip incompatible chandefs */
204		if (!dfs_chan_range_available(mode, i, n_chans, skip_radar))
205			continue;
206
207		if (!is_in_chanlist(iface, chan))
208			continue;
209
210		if (ret_chan && idx == channel_idx) {
211			wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
212			*ret_chan = chan;
213			return idx;
214		}
215		wpa_printf(MSG_DEBUG, "Adding channel: %d", chan->chan);
216		channel_idx++;
217	}
218	return channel_idx;
219}
220
221
222static void dfs_adjust_vht_center_freq(struct hostapd_iface *iface,
223				       struct hostapd_channel_data *chan,
224				       int secondary_channel,
225				       u8 *vht_oper_centr_freq_seg0_idx,
226				       u8 *vht_oper_centr_freq_seg1_idx)
227{
228	if (!iface->conf->ieee80211ac)
229		return;
230
231	if (!chan)
232		return;
233
234	*vht_oper_centr_freq_seg1_idx = 0;
235
236	switch (iface->conf->vht_oper_chwidth) {
237	case VHT_CHANWIDTH_USE_HT:
238		if (secondary_channel == 1)
239			*vht_oper_centr_freq_seg0_idx = chan->chan + 2;
240		else if (secondary_channel == -1)
241			*vht_oper_centr_freq_seg0_idx = chan->chan - 2;
242		else
243			*vht_oper_centr_freq_seg0_idx = chan->chan;
244		break;
245	case VHT_CHANWIDTH_80MHZ:
246		*vht_oper_centr_freq_seg0_idx = chan->chan + 6;
247		break;
248	case VHT_CHANWIDTH_160MHZ:
249		*vht_oper_centr_freq_seg0_idx = chan->chan + 14;
250		break;
251	default:
252		wpa_printf(MSG_INFO, "DFS only VHT20/40/80/160 is supported now");
253		*vht_oper_centr_freq_seg0_idx = 0;
254		break;
255	}
256
257	wpa_printf(MSG_DEBUG, "DFS adjusting VHT center frequency: %d, %d",
258		   *vht_oper_centr_freq_seg0_idx,
259		   *vht_oper_centr_freq_seg1_idx);
260}
261
262
263/* Return start channel idx we will use for mode->channels[idx] */
264static int dfs_get_start_chan_idx(struct hostapd_iface *iface, int *seg1_start)
265{
266	struct hostapd_hw_modes *mode;
267	struct hostapd_channel_data *chan;
268	int channel_no = iface->conf->channel;
269	int res = -1, i;
270	int chan_seg1 = -1;
271
272	*seg1_start = -1;
273
274	/* HT40- */
275	if (iface->conf->ieee80211n && iface->conf->secondary_channel == -1)
276		channel_no -= 4;
277
278	/* VHT */
279	if (iface->conf->ieee80211ac) {
280		switch (iface->conf->vht_oper_chwidth) {
281		case VHT_CHANWIDTH_USE_HT:
282			break;
283		case VHT_CHANWIDTH_80MHZ:
284			channel_no =
285				iface->conf->vht_oper_centr_freq_seg0_idx - 6;
286			break;
287		case VHT_CHANWIDTH_160MHZ:
288			channel_no =
289				iface->conf->vht_oper_centr_freq_seg0_idx - 14;
290			break;
291		case VHT_CHANWIDTH_80P80MHZ:
292			channel_no =
293				iface->conf->vht_oper_centr_freq_seg0_idx - 6;
294			chan_seg1 =
295				iface->conf->vht_oper_centr_freq_seg1_idx - 6;
296			break;
297		default:
298			wpa_printf(MSG_INFO,
299				   "DFS only VHT20/40/80/160/80+80 is supported now");
300			channel_no = -1;
301			break;
302		}
303	}
304
305	/* Get idx */
306	mode = iface->current_mode;
307	for (i = 0; i < mode->num_channels; i++) {
308		chan = &mode->channels[i];
309		if (chan->chan == channel_no) {
310			res = i;
311			break;
312		}
313	}
314
315	if (res != -1 && chan_seg1 > -1) {
316		int found = 0;
317
318		/* Get idx for seg1 */
319		mode = iface->current_mode;
320		for (i = 0; i < mode->num_channels; i++) {
321			chan = &mode->channels[i];
322			if (chan->chan == chan_seg1) {
323				*seg1_start = i;
324				found = 1;
325				break;
326			}
327		}
328		if (!found)
329			res = -1;
330	}
331
332	if (res == -1) {
333		wpa_printf(MSG_DEBUG,
334			   "DFS chan_idx seems wrong; num-ch: %d ch-no: %d conf-ch-no: %d 11n: %d sec-ch: %d vht-oper-width: %d",
335			   mode->num_channels, channel_no, iface->conf->channel,
336			   iface->conf->ieee80211n,
337			   iface->conf->secondary_channel,
338			   iface->conf->vht_oper_chwidth);
339
340		for (i = 0; i < mode->num_channels; i++) {
341			wpa_printf(MSG_DEBUG, "Available channel: %d",
342				   mode->channels[i].chan);
343		}
344	}
345
346	return res;
347}
348
349
350/* At least one channel have radar flag */
351static int dfs_check_chans_radar(struct hostapd_iface *iface,
352				 int start_chan_idx, int n_chans)
353{
354	struct hostapd_channel_data *channel;
355	struct hostapd_hw_modes *mode;
356	int i, res = 0;
357
358	mode = iface->current_mode;
359
360	for (i = 0; i < n_chans; i++) {
361		channel = &mode->channels[start_chan_idx + i];
362		if (channel->flag & HOSTAPD_CHAN_RADAR)
363			res++;
364	}
365
366	return res;
367}
368
369
370/* All channels available */
371static int dfs_check_chans_available(struct hostapd_iface *iface,
372				     int start_chan_idx, int n_chans)
373{
374	struct hostapd_channel_data *channel;
375	struct hostapd_hw_modes *mode;
376	int i;
377
378	mode = iface->current_mode;
379
380	for (i = 0; i < n_chans; i++) {
381		channel = &mode->channels[start_chan_idx + i];
382
383		if (channel->flag & HOSTAPD_CHAN_DISABLED)
384			break;
385
386		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
387			continue;
388
389		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) !=
390		    HOSTAPD_CHAN_DFS_AVAILABLE)
391			break;
392	}
393
394	return i == n_chans;
395}
396
397
398/* At least one channel unavailable */
399static int dfs_check_chans_unavailable(struct hostapd_iface *iface,
400				       int start_chan_idx,
401				       int n_chans)
402{
403	struct hostapd_channel_data *channel;
404	struct hostapd_hw_modes *mode;
405	int i, res = 0;
406
407	mode = iface->current_mode;
408
409	for (i = 0; i < n_chans; i++) {
410		channel = &mode->channels[start_chan_idx + i];
411		if (channel->flag & HOSTAPD_CHAN_DISABLED)
412			res++;
413		if ((channel->flag & HOSTAPD_CHAN_DFS_MASK) ==
414		    HOSTAPD_CHAN_DFS_UNAVAILABLE)
415			res++;
416	}
417
418	return res;
419}
420
421
422static struct hostapd_channel_data *
423dfs_get_valid_channel(struct hostapd_iface *iface,
424		      int *secondary_channel,
425		      u8 *vht_oper_centr_freq_seg0_idx,
426		      u8 *vht_oper_centr_freq_seg1_idx,
427		      int skip_radar)
428{
429	struct hostapd_hw_modes *mode;
430	struct hostapd_channel_data *chan = NULL;
431	int num_available_chandefs;
432	int chan_idx;
433	u32 _rand;
434
435	wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
436	*secondary_channel = 0;
437	*vht_oper_centr_freq_seg0_idx = 0;
438	*vht_oper_centr_freq_seg1_idx = 0;
439
440	if (iface->current_mode == NULL)
441		return NULL;
442
443	mode = iface->current_mode;
444	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
445		return NULL;
446
447	/* Get the count first */
448	num_available_chandefs = dfs_find_channel(iface, NULL, 0, skip_radar);
449	if (num_available_chandefs == 0)
450		return NULL;
451
452	if (os_get_random((u8 *) &_rand, sizeof(_rand)) < 0)
453		return NULL;
454	chan_idx = _rand % num_available_chandefs;
455	dfs_find_channel(iface, &chan, chan_idx, skip_radar);
456
457	/* dfs_find_channel() calculations assume HT40+ */
458	if (iface->conf->secondary_channel)
459		*secondary_channel = 1;
460	else
461		*secondary_channel = 0;
462
463	dfs_adjust_vht_center_freq(iface, chan,
464				   *secondary_channel,
465				   vht_oper_centr_freq_seg0_idx,
466				   vht_oper_centr_freq_seg1_idx);
467
468	return chan;
469}
470
471
472static int set_dfs_state_freq(struct hostapd_iface *iface, int freq, u32 state)
473{
474	struct hostapd_hw_modes *mode;
475	struct hostapd_channel_data *chan = NULL;
476	int i;
477
478	mode = iface->current_mode;
479	if (mode == NULL)
480		return 0;
481
482	wpa_printf(MSG_DEBUG, "set_dfs_state 0x%X for %d MHz", state, freq);
483	for (i = 0; i < iface->current_mode->num_channels; i++) {
484		chan = &iface->current_mode->channels[i];
485		if (chan->freq == freq) {
486			if (chan->flag & HOSTAPD_CHAN_RADAR) {
487				chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
488				chan->flag |= state;
489				return 1; /* Channel found */
490			}
491		}
492	}
493	wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
494	return 0;
495}
496
497
498static int set_dfs_state(struct hostapd_iface *iface, int freq, int ht_enabled,
499			 int chan_offset, int chan_width, int cf1,
500			 int cf2, u32 state)
501{
502	int n_chans = 1, i;
503	struct hostapd_hw_modes *mode;
504	int frequency = freq;
505	int ret = 0;
506
507	mode = iface->current_mode;
508	if (mode == NULL)
509		return 0;
510
511	if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
512		wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
513		return 0;
514	}
515
516	/* Seems cf1 and chan_width is enough here */
517	switch (chan_width) {
518	case CHAN_WIDTH_20_NOHT:
519	case CHAN_WIDTH_20:
520		n_chans = 1;
521		if (frequency == 0)
522			frequency = cf1;
523		break;
524	case CHAN_WIDTH_40:
525		n_chans = 2;
526		frequency = cf1 - 10;
527		break;
528	case CHAN_WIDTH_80:
529		n_chans = 4;
530		frequency = cf1 - 30;
531		break;
532	case CHAN_WIDTH_160:
533		n_chans = 8;
534		frequency = cf1 - 70;
535		break;
536	default:
537		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
538			   chan_width);
539		break;
540	}
541
542	wpa_printf(MSG_DEBUG, "DFS freq: %dMHz, n_chans: %d", frequency,
543		   n_chans);
544	for (i = 0; i < n_chans; i++) {
545		ret += set_dfs_state_freq(iface, frequency, state);
546		frequency = frequency + 20;
547	}
548
549	return ret;
550}
551
552
553static int dfs_are_channels_overlapped(struct hostapd_iface *iface, int freq,
554				       int chan_width, int cf1, int cf2)
555{
556	int start_chan_idx, start_chan_idx1;
557	struct hostapd_hw_modes *mode;
558	struct hostapd_channel_data *chan;
559	int n_chans, n_chans1, i, j, frequency = freq, radar_n_chans = 1;
560	u8 radar_chan;
561	int res = 0;
562
563	/* Our configuration */
564	mode = iface->current_mode;
565	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
566	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
567
568	/* Check we are on DFS channel(s) */
569	if (!dfs_check_chans_radar(iface, start_chan_idx, n_chans))
570		return 0;
571
572	/* Reported via radar event */
573	switch (chan_width) {
574	case CHAN_WIDTH_20_NOHT:
575	case CHAN_WIDTH_20:
576		radar_n_chans = 1;
577		if (frequency == 0)
578			frequency = cf1;
579		break;
580	case CHAN_WIDTH_40:
581		radar_n_chans = 2;
582		frequency = cf1 - 10;
583		break;
584	case CHAN_WIDTH_80:
585		radar_n_chans = 4;
586		frequency = cf1 - 30;
587		break;
588	case CHAN_WIDTH_160:
589		radar_n_chans = 8;
590		frequency = cf1 - 70;
591		break;
592	default:
593		wpa_printf(MSG_INFO, "DFS chan_width %d not supported",
594			   chan_width);
595		break;
596	}
597
598	ieee80211_freq_to_chan(frequency, &radar_chan);
599
600	for (i = 0; i < n_chans; i++) {
601		chan = &mode->channels[start_chan_idx + i];
602		if (!(chan->flag & HOSTAPD_CHAN_RADAR))
603			continue;
604		for (j = 0; j < radar_n_chans; j++) {
605			wpa_printf(MSG_DEBUG, "checking our: %d, radar: %d",
606				   chan->chan, radar_chan + j * 4);
607			if (chan->chan == radar_chan + j * 4)
608				res++;
609		}
610	}
611
612	wpa_printf(MSG_DEBUG, "overlapped: %d", res);
613
614	return res;
615}
616
617
618static unsigned int dfs_get_cac_time(struct hostapd_iface *iface,
619				     int start_chan_idx, int n_chans)
620{
621	struct hostapd_channel_data *channel;
622	struct hostapd_hw_modes *mode;
623	int i;
624	unsigned int cac_time_ms = 0;
625
626	mode = iface->current_mode;
627
628	for (i = 0; i < n_chans; i++) {
629		channel = &mode->channels[start_chan_idx + i];
630		if (!(channel->flag & HOSTAPD_CHAN_RADAR))
631			continue;
632		if (channel->dfs_cac_ms > cac_time_ms)
633			cac_time_ms = channel->dfs_cac_ms;
634	}
635
636	return cac_time_ms;
637}
638
639
640/*
641 * Main DFS handler
642 * 1 - continue channel/ap setup
643 * 0 - channel/ap setup will be continued after CAC
644 * -1 - hit critical error
645 */
646int hostapd_handle_dfs(struct hostapd_iface *iface)
647{
648	struct hostapd_channel_data *channel;
649	int res, n_chans, n_chans1, start_chan_idx, start_chan_idx1;
650	int skip_radar = 0;
651
652	if (!iface->current_mode) {
653		/*
654		 * This can happen with drivers that do not provide mode
655		 * information and as such, cannot really use hostapd for DFS.
656		 */
657		wpa_printf(MSG_DEBUG,
658			   "DFS: No current_mode information - assume no need to perform DFS operations by hostapd");
659		return 1;
660	}
661
662	iface->cac_started = 0;
663
664	do {
665		/* Get start (first) channel for current configuration */
666		start_chan_idx = dfs_get_start_chan_idx(iface,
667							&start_chan_idx1);
668		if (start_chan_idx == -1)
669			return -1;
670
671		/* Get number of used channels, depend on width */
672		n_chans = dfs_get_used_n_chans(iface, &n_chans1);
673
674		/* Setup CAC time */
675		iface->dfs_cac_ms = dfs_get_cac_time(iface, start_chan_idx,
676						     n_chans);
677
678		/* Check if any of configured channels require DFS */
679		res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
680		wpa_printf(MSG_DEBUG,
681			   "DFS %d channels required radar detection",
682			   res);
683		if (!res)
684			return 1;
685
686		/* Check if all channels are DFS available */
687		res = dfs_check_chans_available(iface, start_chan_idx, n_chans);
688		wpa_printf(MSG_DEBUG,
689			   "DFS all channels available, (SKIP CAC): %s",
690			   res ? "yes" : "no");
691		if (res)
692			return 1;
693
694		/* Check if any of configured channels is unavailable */
695		res = dfs_check_chans_unavailable(iface, start_chan_idx,
696						  n_chans);
697		wpa_printf(MSG_DEBUG, "DFS %d chans unavailable - choose other channel: %s",
698			   res, res ? "yes": "no");
699		if (res) {
700			int sec = 0;
701			u8 cf1 = 0, cf2 = 0;
702
703			channel = dfs_get_valid_channel(iface, &sec, &cf1, &cf2,
704							skip_radar);
705			if (!channel) {
706				wpa_printf(MSG_ERROR, "could not get valid channel");
707				hostapd_set_state(iface, HAPD_IFACE_DFS);
708				return 0;
709			}
710
711			iface->freq = channel->freq;
712			iface->conf->channel = channel->chan;
713			iface->conf->secondary_channel = sec;
714			iface->conf->vht_oper_centr_freq_seg0_idx = cf1;
715			iface->conf->vht_oper_centr_freq_seg1_idx = cf2;
716		}
717	} while (res);
718
719	/* Finally start CAC */
720	hostapd_set_state(iface, HAPD_IFACE_DFS);
721	wpa_printf(MSG_DEBUG, "DFS start CAC on %d MHz", iface->freq);
722	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
723		"freq=%d chan=%d sec_chan=%d, width=%d, seg0=%d, seg1=%d, cac_time=%ds",
724		iface->freq,
725		iface->conf->channel, iface->conf->secondary_channel,
726		iface->conf->vht_oper_chwidth,
727		iface->conf->vht_oper_centr_freq_seg0_idx,
728		iface->conf->vht_oper_centr_freq_seg1_idx,
729		iface->dfs_cac_ms / 1000);
730
731	res = hostapd_start_dfs_cac(iface, iface->conf->hw_mode,
732				    iface->freq,
733				    iface->conf->channel,
734				    iface->conf->ieee80211n,
735				    iface->conf->ieee80211ac,
736				    iface->conf->secondary_channel,
737				    iface->conf->vht_oper_chwidth,
738				    iface->conf->vht_oper_centr_freq_seg0_idx,
739				    iface->conf->vht_oper_centr_freq_seg1_idx);
740
741	if (res) {
742		wpa_printf(MSG_ERROR, "DFS start_dfs_cac() failed, %d", res);
743		return -1;
744	}
745
746	return 0;
747}
748
749
750static int hostapd_config_dfs_chan_available(struct hostapd_iface *iface)
751{
752	int n_chans, n_chans1, start_chan_idx, start_chan_idx1;
753
754	/* Get the start (first) channel for current configuration */
755	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
756	if (start_chan_idx < 0)
757		return 0;
758
759	/* Get the number of used channels, depending on width */
760	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
761
762	/* Check if all channels are DFS available */
763	return dfs_check_chans_available(iface, start_chan_idx, n_chans);
764}
765
766
767int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
768			     int ht_enabled, int chan_offset, int chan_width,
769			     int cf1, int cf2)
770{
771	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
772		"success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
773		success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
774
775	if (success) {
776		/* Complete iface/ap configuration */
777		if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) {
778			/* Complete AP configuration for the first bring up. */
779			if (iface->state != HAPD_IFACE_ENABLED)
780				hostapd_setup_interface_complete(iface, 0);
781			else
782				iface->cac_started = 0;
783		} else {
784			set_dfs_state(iface, freq, ht_enabled, chan_offset,
785				      chan_width, cf1, cf2,
786				      HOSTAPD_CHAN_DFS_AVAILABLE);
787			/*
788			 * Just mark the channel available when CAC completion
789			 * event is received in enabled state. CAC result could
790			 * have been propagated from another radio having the
791			 * same regulatory configuration. When CAC completion is
792			 * received during non-HAPD_IFACE_ENABLED state, make
793			 * sure the configured channel is available because this
794			 * CAC completion event could have been propagated from
795			 * another radio.
796			 */
797			if (iface->state != HAPD_IFACE_ENABLED &&
798			    hostapd_config_dfs_chan_available(iface)) {
799				hostapd_setup_interface_complete(iface, 0);
800				iface->cac_started = 0;
801			}
802		}
803	}
804
805	return 0;
806}
807
808
809int hostapd_dfs_pre_cac_expired(struct hostapd_iface *iface, int freq,
810				int ht_enabled, int chan_offset, int chan_width,
811				int cf1, int cf2)
812{
813	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_PRE_CAC_EXPIRED
814		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
815		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
816
817	/* Proceed only if DFS is not offloaded to the driver */
818	if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
819		return 0;
820
821	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
822		      cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
823
824	return 0;
825}
826
827
828static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
829{
830	struct hostapd_channel_data *channel;
831	int secondary_channel;
832	u8 vht_oper_centr_freq_seg0_idx = 0;
833	u8 vht_oper_centr_freq_seg1_idx = 0;
834	int skip_radar = 0;
835	int err = 1;
836
837	/* Radar detected during active CAC */
838	iface->cac_started = 0;
839	channel = dfs_get_valid_channel(iface, &secondary_channel,
840					&vht_oper_centr_freq_seg0_idx,
841					&vht_oper_centr_freq_seg1_idx,
842					skip_radar);
843
844	if (!channel) {
845		wpa_printf(MSG_ERROR, "No valid channel available");
846		return err;
847	}
848
849	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
850		   channel->chan);
851	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
852		"freq=%d chan=%d sec_chan=%d", channel->freq,
853		channel->chan, secondary_channel);
854
855	iface->freq = channel->freq;
856	iface->conf->channel = channel->chan;
857	iface->conf->secondary_channel = secondary_channel;
858	iface->conf->vht_oper_centr_freq_seg0_idx =
859		vht_oper_centr_freq_seg0_idx;
860	iface->conf->vht_oper_centr_freq_seg1_idx =
861		vht_oper_centr_freq_seg1_idx;
862	err = 0;
863
864	hostapd_setup_interface_complete(iface, err);
865	return err;
866}
867
868
869static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
870{
871	struct hostapd_channel_data *channel;
872	int secondary_channel;
873	u8 vht_oper_centr_freq_seg0_idx;
874	u8 vht_oper_centr_freq_seg1_idx;
875	int skip_radar = 1;
876	struct csa_settings csa_settings;
877	unsigned int i;
878	int err = 1;
879
880	wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
881		   __func__, iface->cac_started ? "yes" : "no",
882		   hostapd_csa_in_progress(iface) ? "yes" : "no");
883
884	/* Check if CSA in progress */
885	if (hostapd_csa_in_progress(iface))
886		return 0;
887
888	/* Check if active CAC */
889	if (iface->cac_started)
890		return hostapd_dfs_start_channel_switch_cac(iface);
891
892	/*
893	 * Allow selection of DFS channel in ETSI to comply with
894	 * uniform spreading.
895	 */
896	if (iface->dfs_domain == HOSTAPD_DFS_REGION_ETSI)
897		skip_radar = 0;
898
899	/* Perform channel switch/CSA */
900	channel = dfs_get_valid_channel(iface, &secondary_channel,
901					&vht_oper_centr_freq_seg0_idx,
902					&vht_oper_centr_freq_seg1_idx,
903					skip_radar);
904
905	if (!channel) {
906		/*
907		 * If there is no channel to switch immediately to, check if
908		 * there is another channel where we can switch even if it
909		 * requires to perform a CAC first.
910		 */
911		skip_radar = 0;
912		channel = dfs_get_valid_channel(iface, &secondary_channel,
913						&vht_oper_centr_freq_seg0_idx,
914						&vht_oper_centr_freq_seg1_idx,
915						skip_radar);
916		if (!channel) {
917			wpa_printf(MSG_INFO,
918				   "%s: no DFS channels left, waiting for NOP to finish",
919				   __func__);
920			return err;
921		}
922
923		iface->freq = channel->freq;
924		iface->conf->channel = channel->chan;
925		iface->conf->secondary_channel = secondary_channel;
926		iface->conf->vht_oper_centr_freq_seg0_idx =
927			vht_oper_centr_freq_seg0_idx;
928		iface->conf->vht_oper_centr_freq_seg1_idx =
929			vht_oper_centr_freq_seg1_idx;
930
931		hostapd_disable_iface(iface);
932		hostapd_enable_iface(iface);
933		return 0;
934	}
935
936	wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
937		   channel->chan);
938	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
939		"freq=%d chan=%d sec_chan=%d", channel->freq,
940		channel->chan, secondary_channel);
941
942	/* Setup CSA request */
943	os_memset(&csa_settings, 0, sizeof(csa_settings));
944	csa_settings.cs_count = 5;
945	csa_settings.block_tx = 1;
946	err = hostapd_set_freq_params(&csa_settings.freq_params,
947				      iface->conf->hw_mode,
948				      channel->freq,
949				      channel->chan,
950				      iface->conf->ieee80211n,
951				      iface->conf->ieee80211ac,
952				      secondary_channel,
953				      iface->conf->vht_oper_chwidth,
954				      vht_oper_centr_freq_seg0_idx,
955				      vht_oper_centr_freq_seg1_idx,
956				      iface->current_mode->vht_capab);
957
958	if (err) {
959		wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
960		hostapd_disable_iface(iface);
961		return err;
962	}
963
964	for (i = 0; i < iface->num_bss; i++) {
965		err = hostapd_switch_channel(iface->bss[i], &csa_settings);
966		if (err)
967			break;
968	}
969
970	if (err) {
971		wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
972			   err);
973		iface->freq = channel->freq;
974		iface->conf->channel = channel->chan;
975		iface->conf->secondary_channel = secondary_channel;
976		iface->conf->vht_oper_centr_freq_seg0_idx =
977			vht_oper_centr_freq_seg0_idx;
978		iface->conf->vht_oper_centr_freq_seg1_idx =
979			vht_oper_centr_freq_seg1_idx;
980
981		hostapd_disable_iface(iface);
982		hostapd_enable_iface(iface);
983		return 0;
984	}
985
986	/* Channel configuration will be updated once CSA completes and
987	 * ch_switch_notify event is received */
988
989	wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
990	return 0;
991}
992
993
994int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
995			       int ht_enabled, int chan_offset, int chan_width,
996			       int cf1, int cf2)
997{
998	int res;
999
1000	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
1001		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
1002		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
1003
1004	/* Proceed only if DFS is not offloaded to the driver */
1005	if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
1006		return 0;
1007
1008	if (!iface->conf->ieee80211h)
1009		return 0;
1010
1011	/* mark radar frequency as invalid */
1012	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
1013		      cf1, cf2, HOSTAPD_CHAN_DFS_UNAVAILABLE);
1014
1015	/* Skip if reported radar event not overlapped our channels */
1016	res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
1017	if (!res)
1018		return 0;
1019
1020	/* radar detected while operating, switch the channel. */
1021	res = hostapd_dfs_start_channel_switch(iface);
1022
1023	return res;
1024}
1025
1026
1027int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
1028			     int ht_enabled, int chan_offset, int chan_width,
1029			     int cf1, int cf2)
1030{
1031	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
1032		"freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
1033		freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
1034
1035	/* Proceed only if DFS is not offloaded to the driver */
1036	if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
1037		return 0;
1038
1039	/* TODO add correct implementation here */
1040	set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
1041		      cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
1042
1043	/* Handle cases where all channels were initially unavailable */
1044	if (iface->state == HAPD_IFACE_DFS && !iface->cac_started)
1045		hostapd_handle_dfs(iface);
1046
1047	return 0;
1048}
1049
1050
1051int hostapd_is_dfs_required(struct hostapd_iface *iface)
1052{
1053	int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
1054
1055	if (!iface->conf->ieee80211h || !iface->current_mode ||
1056	    iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
1057		return 0;
1058
1059	/* Get start (first) channel for current configuration */
1060	start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
1061	if (start_chan_idx == -1)
1062		return -1;
1063
1064	/* Get number of used channels, depend on width */
1065	n_chans = dfs_get_used_n_chans(iface, &n_chans1);
1066
1067	/* Check if any of configured channels require DFS */
1068	res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
1069	if (res)
1070		return res;
1071	if (start_chan_idx1 >= 0 && n_chans1 > 0)
1072		res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
1073	return res;
1074}
1075
1076
1077int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
1078			  int ht_enabled, int chan_offset, int chan_width,
1079			  int cf1, int cf2)
1080{
1081	wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
1082		"freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
1083		"seg1=%d cac_time=%ds",
1084		freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2, 60);
1085	iface->cac_started = 1;
1086	return 0;
1087}
1088
1089
1090/*
1091 * Main DFS handler for offloaded case.
1092 * 2 - continue channel/AP setup for non-DFS channel
1093 * 1 - continue channel/AP setup for DFS channel
1094 * 0 - channel/AP setup will be continued after CAC
1095 * -1 - hit critical error
1096 */
1097int hostapd_handle_dfs_offload(struct hostapd_iface *iface)
1098{
1099	wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1100		   __func__, iface->cac_started);
1101
1102	/*
1103	 * If DFS has already been started, then we are being called from a
1104	 * callback to continue AP/channel setup. Reset the CAC start flag and
1105	 * return.
1106	 */
1107	if (iface->cac_started) {
1108		wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1109			   __func__, iface->cac_started);
1110		iface->cac_started = 0;
1111		return 1;
1112	}
1113
1114	if (ieee80211_is_dfs(iface->freq)) {
1115		wpa_printf(MSG_DEBUG, "%s: freq %d MHz requires DFS",
1116			   __func__, iface->freq);
1117		return 0;
1118	}
1119
1120	wpa_printf(MSG_DEBUG,
1121		   "%s: freq %d MHz does not require DFS. Continue channel/AP setup",
1122		   __func__, iface->freq);
1123	return 2;
1124}
1125