1 /*
2 * DFS - Dynamic Frequency Selection
3 * Copyright (c) 2002-2013, Jouni Malinen <j@w1.fi>
4 * Copyright (c) 2013-2015, 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
dfs_get_used_n_chans(struct hostapd_iface * iface,int * seg1)22 static 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
dfs_channel_available(struct hostapd_channel_data * chan,int skip_radar)54 static 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
dfs_is_chan_allowed(struct hostapd_channel_data * chan,int n_chans)77 static 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
125 static struct hostapd_channel_data *
dfs_get_chan_data(struct hostapd_hw_modes * mode,int freq,int first_chan_idx)126 dfs_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
dfs_chan_range_available(struct hostapd_hw_modes * mode,int first_chan_idx,int num_chans,int skip_radar)139 static 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
is_in_chanlist(struct hostapd_iface * iface,struct hostapd_channel_data * chan)165 static 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 */
dfs_find_channel(struct hostapd_iface * iface,struct hostapd_channel_data ** ret_chan,int idx,int skip_radar)182 static 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
dfs_adjust_vht_center_freq(struct hostapd_iface * iface,struct hostapd_channel_data * chan,int secondary_channel,u8 * vht_oper_centr_freq_seg0_idx,u8 * vht_oper_centr_freq_seg1_idx)222 static 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] */
dfs_get_start_chan_idx(struct hostapd_iface * iface,int * seg1_start)264 static 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 */
dfs_check_chans_radar(struct hostapd_iface * iface,int start_chan_idx,int n_chans)351 static 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 */
dfs_check_chans_available(struct hostapd_iface * iface,int start_chan_idx,int n_chans)371 static 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 */
dfs_check_chans_unavailable(struct hostapd_iface * iface,int start_chan_idx,int n_chans)399 static 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
422 static struct hostapd_channel_data *
dfs_get_valid_channel(struct hostapd_iface * iface,int * secondary_channel,u8 * vht_oper_centr_freq_seg0_idx,u8 * vht_oper_centr_freq_seg1_idx,int skip_radar)423 dfs_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
set_dfs_state_freq(struct hostapd_iface * iface,int freq,u32 state)472 static 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
set_dfs_state(struct hostapd_iface * iface,int freq,int ht_enabled,int chan_offset,int chan_width,int cf1,int cf2,u32 state)498 static 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
dfs_are_channels_overlapped(struct hostapd_iface * iface,int freq,int chan_width,int cf1,int cf2)553 static 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
dfs_get_cac_time(struct hostapd_iface * iface,int start_chan_idx,int n_chans)618 static 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 */
hostapd_handle_dfs(struct hostapd_iface * iface)646 int 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
hostapd_dfs_complete_cac(struct hostapd_iface * iface,int success,int freq,int ht_enabled,int chan_offset,int chan_width,int cf1,int cf2)750 int hostapd_dfs_complete_cac(struct hostapd_iface *iface, int success, int freq,
751 int ht_enabled, int chan_offset, int chan_width,
752 int cf1, int cf2)
753 {
754 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_COMPLETED
755 "success=%d freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
756 success, freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
757
758 if (success) {
759 /* Complete iface/ap configuration */
760 if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD) {
761 /* Complete AP configuration for the first bring up. */
762 if (iface->state != HAPD_IFACE_ENABLED)
763 hostapd_setup_interface_complete(iface, 0);
764 else
765 iface->cac_started = 0;
766 } else {
767 set_dfs_state(iface, freq, ht_enabled, chan_offset,
768 chan_width, cf1, cf2,
769 HOSTAPD_CHAN_DFS_AVAILABLE);
770 iface->cac_started = 0;
771 hostapd_setup_interface_complete(iface, 0);
772 }
773 }
774
775 return 0;
776 }
777
778
hostapd_dfs_start_channel_switch_cac(struct hostapd_iface * iface)779 static int hostapd_dfs_start_channel_switch_cac(struct hostapd_iface *iface)
780 {
781 struct hostapd_channel_data *channel;
782 int secondary_channel;
783 u8 vht_oper_centr_freq_seg0_idx = 0;
784 u8 vht_oper_centr_freq_seg1_idx = 0;
785 int skip_radar = 0;
786 int err = 1;
787
788 /* Radar detected during active CAC */
789 iface->cac_started = 0;
790 channel = dfs_get_valid_channel(iface, &secondary_channel,
791 &vht_oper_centr_freq_seg0_idx,
792 &vht_oper_centr_freq_seg1_idx,
793 skip_radar);
794
795 if (!channel) {
796 wpa_printf(MSG_ERROR, "No valid channel available");
797 return err;
798 }
799
800 wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
801 channel->chan);
802 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
803 "freq=%d chan=%d sec_chan=%d", channel->freq,
804 channel->chan, secondary_channel);
805
806 iface->freq = channel->freq;
807 iface->conf->channel = channel->chan;
808 iface->conf->secondary_channel = secondary_channel;
809 iface->conf->vht_oper_centr_freq_seg0_idx =
810 vht_oper_centr_freq_seg0_idx;
811 iface->conf->vht_oper_centr_freq_seg1_idx =
812 vht_oper_centr_freq_seg1_idx;
813 err = 0;
814
815 hostapd_setup_interface_complete(iface, err);
816 return err;
817 }
818
819
hostapd_dfs_start_channel_switch(struct hostapd_iface * iface)820 static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
821 {
822 struct hostapd_channel_data *channel;
823 int secondary_channel;
824 u8 vht_oper_centr_freq_seg0_idx;
825 u8 vht_oper_centr_freq_seg1_idx;
826 int skip_radar = 1;
827 struct csa_settings csa_settings;
828 unsigned int i;
829 int err = 1;
830
831 wpa_printf(MSG_DEBUG, "%s called (CAC active: %s, CSA active: %s)",
832 __func__, iface->cac_started ? "yes" : "no",
833 hostapd_csa_in_progress(iface) ? "yes" : "no");
834
835 /* Check if CSA in progress */
836 if (hostapd_csa_in_progress(iface))
837 return 0;
838
839 /* Check if active CAC */
840 if (iface->cac_started)
841 return hostapd_dfs_start_channel_switch_cac(iface);
842
843 /* Perform channel switch/CSA */
844 channel = dfs_get_valid_channel(iface, &secondary_channel,
845 &vht_oper_centr_freq_seg0_idx,
846 &vht_oper_centr_freq_seg1_idx,
847 skip_radar);
848
849 if (!channel) {
850 /*
851 * If there is no channel to switch immediately to, check if
852 * there is another channel where we can switch even if it
853 * requires to perform a CAC first.
854 */
855 skip_radar = 0;
856 channel = dfs_get_valid_channel(iface, &secondary_channel,
857 &vht_oper_centr_freq_seg0_idx,
858 &vht_oper_centr_freq_seg1_idx,
859 skip_radar);
860 if (!channel) {
861 wpa_printf(MSG_INFO,
862 "%s: no DFS channels left, waiting for NOP to finish",
863 __func__);
864 return err;
865 }
866
867 iface->freq = channel->freq;
868 iface->conf->channel = channel->chan;
869 iface->conf->secondary_channel = secondary_channel;
870 iface->conf->vht_oper_centr_freq_seg0_idx =
871 vht_oper_centr_freq_seg0_idx;
872 iface->conf->vht_oper_centr_freq_seg1_idx =
873 vht_oper_centr_freq_seg1_idx;
874
875 hostapd_disable_iface(iface);
876 hostapd_enable_iface(iface);
877 return 0;
878 }
879
880 wpa_printf(MSG_DEBUG, "DFS will switch to a new channel %d",
881 channel->chan);
882 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NEW_CHANNEL
883 "freq=%d chan=%d sec_chan=%d", channel->freq,
884 channel->chan, secondary_channel);
885
886 /* Setup CSA request */
887 os_memset(&csa_settings, 0, sizeof(csa_settings));
888 csa_settings.cs_count = 5;
889 csa_settings.block_tx = 1;
890 err = hostapd_set_freq_params(&csa_settings.freq_params,
891 iface->conf->hw_mode,
892 channel->freq,
893 channel->chan,
894 iface->conf->ieee80211n,
895 iface->conf->ieee80211ac,
896 secondary_channel,
897 iface->conf->vht_oper_chwidth,
898 vht_oper_centr_freq_seg0_idx,
899 vht_oper_centr_freq_seg1_idx,
900 iface->current_mode->vht_capab);
901
902 if (err) {
903 wpa_printf(MSG_ERROR, "DFS failed to calculate CSA freq params");
904 hostapd_disable_iface(iface);
905 return err;
906 }
907
908 for (i = 0; i < iface->num_bss; i++) {
909 err = hostapd_switch_channel(iface->bss[i], &csa_settings);
910 if (err)
911 break;
912 }
913
914 if (err) {
915 wpa_printf(MSG_WARNING, "DFS failed to schedule CSA (%d) - trying fallback",
916 err);
917 iface->freq = channel->freq;
918 iface->conf->channel = channel->chan;
919 iface->conf->secondary_channel = secondary_channel;
920 iface->conf->vht_oper_centr_freq_seg0_idx =
921 vht_oper_centr_freq_seg0_idx;
922 iface->conf->vht_oper_centr_freq_seg1_idx =
923 vht_oper_centr_freq_seg1_idx;
924
925 hostapd_disable_iface(iface);
926 hostapd_enable_iface(iface);
927 return 0;
928 }
929
930 /* Channel configuration will be updated once CSA completes and
931 * ch_switch_notify event is received */
932
933 wpa_printf(MSG_DEBUG, "DFS waiting channel switch event");
934 return 0;
935 }
936
937
hostapd_dfs_radar_detected(struct hostapd_iface * iface,int freq,int ht_enabled,int chan_offset,int chan_width,int cf1,int cf2)938 int hostapd_dfs_radar_detected(struct hostapd_iface *iface, int freq,
939 int ht_enabled, int chan_offset, int chan_width,
940 int cf1, int cf2)
941 {
942 int res;
943
944 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_RADAR_DETECTED
945 "freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
946 freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
947
948 /* Proceed only if DFS is not offloaded to the driver */
949 if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
950 return 0;
951
952 if (!iface->conf->ieee80211h)
953 return 0;
954
955 /* mark radar frequency as invalid */
956 set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
957 cf1, cf2, HOSTAPD_CHAN_DFS_UNAVAILABLE);
958
959 /* Skip if reported radar event not overlapped our channels */
960 res = dfs_are_channels_overlapped(iface, freq, chan_width, cf1, cf2);
961 if (!res)
962 return 0;
963
964 /* radar detected while operating, switch the channel. */
965 res = hostapd_dfs_start_channel_switch(iface);
966
967 return res;
968 }
969
970
hostapd_dfs_nop_finished(struct hostapd_iface * iface,int freq,int ht_enabled,int chan_offset,int chan_width,int cf1,int cf2)971 int hostapd_dfs_nop_finished(struct hostapd_iface *iface, int freq,
972 int ht_enabled, int chan_offset, int chan_width,
973 int cf1, int cf2)
974 {
975 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_NOP_FINISHED
976 "freq=%d ht_enabled=%d chan_offset=%d chan_width=%d cf1=%d cf2=%d",
977 freq, ht_enabled, chan_offset, chan_width, cf1, cf2);
978
979 /* Proceed only if DFS is not offloaded to the driver */
980 if (iface->drv_flags & WPA_DRIVER_FLAGS_DFS_OFFLOAD)
981 return 0;
982
983 /* TODO add correct implementation here */
984 set_dfs_state(iface, freq, ht_enabled, chan_offset, chan_width,
985 cf1, cf2, HOSTAPD_CHAN_DFS_USABLE);
986
987 /* Handle cases where all channels were initially unavailable */
988 if (iface->state == HAPD_IFACE_DFS && !iface->cac_started)
989 hostapd_handle_dfs(iface);
990
991 return 0;
992 }
993
994
hostapd_is_dfs_required(struct hostapd_iface * iface)995 int hostapd_is_dfs_required(struct hostapd_iface *iface)
996 {
997 int n_chans, n_chans1, start_chan_idx, start_chan_idx1, res;
998
999 if (!iface->conf->ieee80211h || !iface->current_mode ||
1000 iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A)
1001 return 0;
1002
1003 /* Get start (first) channel for current configuration */
1004 start_chan_idx = dfs_get_start_chan_idx(iface, &start_chan_idx1);
1005 if (start_chan_idx == -1)
1006 return -1;
1007
1008 /* Get number of used channels, depend on width */
1009 n_chans = dfs_get_used_n_chans(iface, &n_chans1);
1010
1011 /* Check if any of configured channels require DFS */
1012 res = dfs_check_chans_radar(iface, start_chan_idx, n_chans);
1013 if (res)
1014 return res;
1015 if (start_chan_idx1 >= 0 && n_chans1 > 0)
1016 res = dfs_check_chans_radar(iface, start_chan_idx1, n_chans1);
1017 return res;
1018 }
1019
1020
hostapd_dfs_start_cac(struct hostapd_iface * iface,int freq,int ht_enabled,int chan_offset,int chan_width,int cf1,int cf2)1021 int hostapd_dfs_start_cac(struct hostapd_iface *iface, int freq,
1022 int ht_enabled, int chan_offset, int chan_width,
1023 int cf1, int cf2)
1024 {
1025 wpa_msg(iface->bss[0]->msg_ctx, MSG_INFO, DFS_EVENT_CAC_START
1026 "freq=%d chan=%d chan_offset=%d width=%d seg0=%d "
1027 "seg1=%d cac_time=%ds",
1028 freq, (freq - 5000) / 5, chan_offset, chan_width, cf1, cf2, 60);
1029 iface->cac_started = 1;
1030 return 0;
1031 }
1032
1033
1034 /*
1035 * Main DFS handler for offloaded case.
1036 * 2 - continue channel/AP setup for non-DFS channel
1037 * 1 - continue channel/AP setup for DFS channel
1038 * 0 - channel/AP setup will be continued after CAC
1039 * -1 - hit critical error
1040 */
hostapd_handle_dfs_offload(struct hostapd_iface * iface)1041 int hostapd_handle_dfs_offload(struct hostapd_iface *iface)
1042 {
1043 wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1044 __func__, iface->cac_started);
1045
1046 /*
1047 * If DFS has already been started, then we are being called from a
1048 * callback to continue AP/channel setup. Reset the CAC start flag and
1049 * return.
1050 */
1051 if (iface->cac_started) {
1052 wpa_printf(MSG_DEBUG, "%s: iface->cac_started: %d",
1053 __func__, iface->cac_started);
1054 iface->cac_started = 0;
1055 return 1;
1056 }
1057
1058 if (ieee80211_is_dfs(iface->freq)) {
1059 wpa_printf(MSG_DEBUG, "%s: freq %d MHz requires DFS",
1060 __func__, iface->freq);
1061 return 0;
1062 }
1063
1064 wpa_printf(MSG_DEBUG,
1065 "%s: freq %d MHz does not require DFS. Continue channel/AP setup",
1066 __func__, iface->freq);
1067 return 2;
1068 }
1069