xref: /linux/net/mac80211/scan.c (revision f058b2dd70b1a5503dff899010aeb53b436091e5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Scanning implementation
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2004, Instant802 Networks, Inc.
7  * Copyright 2005, Devicescape Software, Inc.
8  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2013-2015  Intel Mobile Communications GmbH
11  * Copyright 2016-2017  Intel Deutschland GmbH
12  * Copyright (C) 2018-2024 Intel Corporation
13  */
14 
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23 
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27 
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31 
32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 			  struct ieee80211_bss *bss)
34 {
35 	if (!bss)
36 		return;
37 	cfg80211_put_bss(local->hw.wiphy,
38 			 container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40 
41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43 	u8 qos_info;
44 
45 	if (elems->wmm_info && elems->wmm_info_len == 7
46 	    && elems->wmm_info[5] == 1)
47 		qos_info = elems->wmm_info[6];
48 	else if (elems->wmm_param && elems->wmm_param_len == 24
49 		 && elems->wmm_param[5] == 1)
50 		qos_info = elems->wmm_param[6];
51 	else
52 		/* no valid wmm information or parameter element found */
53 		return false;
54 
55 	return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57 
58 struct inform_bss_update_data {
59 	struct ieee80211_rx_status *rx_status;
60 	bool beacon;
61 };
62 
63 void ieee80211_inform_bss(struct wiphy *wiphy,
64 			  struct cfg80211_bss *cbss,
65 			  const struct cfg80211_bss_ies *ies,
66 			  void *data)
67 {
68 	struct ieee80211_local *local = wiphy_priv(wiphy);
69 	struct inform_bss_update_data *update_data = data;
70 	struct ieee80211_bss *bss = (void *)cbss->priv;
71 	struct ieee80211_rx_status *rx_status;
72 	struct ieee802_11_elems *elems;
73 	int clen, srlen;
74 
75 	/* This happens while joining an IBSS */
76 	if (!update_data)
77 		return;
78 
79 	elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
80 	if (!elems)
81 		return;
82 
83 	rx_status = update_data->rx_status;
84 
85 	if (update_data->beacon)
86 		bss->device_ts_beacon = rx_status->device_timestamp;
87 	else
88 		bss->device_ts_presp = rx_status->device_timestamp;
89 
90 	if (elems->parse_error) {
91 		if (update_data->beacon)
92 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
93 		else
94 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 	} else {
96 		if (update_data->beacon)
97 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
98 		else
99 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 	}
101 
102 	/* save the ERP value so that it is available at association time */
103 	if (elems->erp_info && (!elems->parse_error ||
104 				!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
105 		bss->erp_value = elems->erp_info[0];
106 		bss->has_erp_value = true;
107 		if (!elems->parse_error)
108 			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 	}
110 
111 	/* replace old supported rates if we get new values */
112 	if (!elems->parse_error ||
113 	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
114 		srlen = 0;
115 		if (elems->supp_rates) {
116 			clen = IEEE80211_MAX_SUPP_RATES;
117 			if (clen > elems->supp_rates_len)
118 				clen = elems->supp_rates_len;
119 			memcpy(bss->supp_rates, elems->supp_rates, clen);
120 			srlen += clen;
121 		}
122 		if (elems->ext_supp_rates) {
123 			clen = IEEE80211_MAX_SUPP_RATES - srlen;
124 			if (clen > elems->ext_supp_rates_len)
125 				clen = elems->ext_supp_rates_len;
126 			memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
127 			       clen);
128 			srlen += clen;
129 		}
130 		if (srlen) {
131 			bss->supp_rates_len = srlen;
132 			if (!elems->parse_error)
133 				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
134 		}
135 	}
136 
137 	if (!elems->parse_error ||
138 	    !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
139 		bss->wmm_used = elems->wmm_param || elems->wmm_info;
140 		bss->uapsd_supported = is_uapsd_supported(elems);
141 		if (!elems->parse_error)
142 			bss->valid_data |= IEEE80211_BSS_VALID_WMM;
143 	}
144 
145 	if (update_data->beacon) {
146 		struct ieee80211_supported_band *sband =
147 			local->hw.wiphy->bands[rx_status->band];
148 		if (!(rx_status->encoding == RX_ENC_HT) &&
149 		    !(rx_status->encoding == RX_ENC_VHT))
150 			bss->beacon_rate =
151 				&sband->bitrates[rx_status->rate_idx];
152 	}
153 
154 	if (elems->vht_cap_elem)
155 		bss->vht_cap_info =
156 			le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
157 	else
158 		bss->vht_cap_info = 0;
159 
160 	kfree(elems);
161 }
162 
163 struct ieee80211_bss *
164 ieee80211_bss_info_update(struct ieee80211_local *local,
165 			  struct ieee80211_rx_status *rx_status,
166 			  struct ieee80211_mgmt *mgmt, size_t len,
167 			  struct ieee80211_channel *channel)
168 {
169 	bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
170 		      ieee80211_is_s1g_beacon(mgmt->frame_control);
171 	struct cfg80211_bss *cbss;
172 	struct inform_bss_update_data update_data = {
173 		.rx_status = rx_status,
174 		.beacon = beacon,
175 	};
176 	struct cfg80211_inform_bss bss_meta = {
177 		.boottime_ns = rx_status->boottime_ns,
178 		.drv_data = (void *)&update_data,
179 	};
180 	bool signal_valid;
181 	struct ieee80211_sub_if_data *scan_sdata;
182 
183 	if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
184 		bss_meta.signal = 0; /* invalid signal indication */
185 	else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
186 		bss_meta.signal = rx_status->signal * 100;
187 	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
188 		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
189 
190 	bss_meta.chan = channel;
191 
192 	rcu_read_lock();
193 	scan_sdata = rcu_dereference(local->scan_sdata);
194 	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
195 	    scan_sdata->vif.cfg.assoc &&
196 	    ieee80211_have_rx_timestamp(rx_status)) {
197 		struct ieee80211_bss_conf *link_conf = NULL;
198 
199 		/* for an MLO connection, set the TSF data only in case we have
200 		 * an indication on which of the links the frame was received
201 		 */
202 		if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
203 			if (rx_status->link_valid) {
204 				s8 link_id = rx_status->link_id;
205 
206 				link_conf =
207 					rcu_dereference(scan_sdata->vif.link_conf[link_id]);
208 			}
209 		} else {
210 			link_conf = &scan_sdata->vif.bss_conf;
211 		}
212 
213 		if (link_conf) {
214 			bss_meta.parent_tsf =
215 				ieee80211_calculate_rx_timestamp(local,
216 								 rx_status,
217 								 len + FCS_LEN,
218 								 24);
219 
220 			ether_addr_copy(bss_meta.parent_bssid,
221 					link_conf->bssid);
222 		}
223 	}
224 	rcu_read_unlock();
225 
226 	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
227 					      mgmt, len, GFP_ATOMIC);
228 	if (!cbss)
229 		return NULL;
230 
231 	/* In case the signal is invalid update the status */
232 	signal_valid = channel == cbss->channel;
233 	if (!signal_valid)
234 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
235 
236 	return (void *)cbss->priv;
237 }
238 
239 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
240 					struct ieee80211_channel *channel,
241 					u32 scan_flags, const u8 *da)
242 {
243 	if (!sdata)
244 		return false;
245 
246 	/* accept broadcast on 6 GHz and for OCE */
247 	if (is_broadcast_ether_addr(da) &&
248 	    (channel->band == NL80211_BAND_6GHZ ||
249 	     scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
250 		return true;
251 
252 	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
253 		return true;
254 	return ether_addr_equal(da, sdata->vif.addr);
255 }
256 
257 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
258 {
259 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
260 	struct ieee80211_sub_if_data *sdata1, *sdata2;
261 	struct ieee80211_mgmt *mgmt = (void *)skb->data;
262 	struct ieee80211_bss *bss;
263 	struct ieee80211_channel *channel;
264 	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
265 				      u.probe_resp.variable);
266 
267 	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
268 	    !ieee80211_is_beacon(mgmt->frame_control) &&
269 	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
270 		return;
271 
272 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
273 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
274 			min_hdr_len = offsetof(struct ieee80211_ext,
275 					       u.s1g_short_beacon.variable);
276 		else
277 			min_hdr_len = offsetof(struct ieee80211_ext,
278 					       u.s1g_beacon);
279 	}
280 
281 	if (skb->len < min_hdr_len)
282 		return;
283 
284 	sdata1 = rcu_dereference(local->scan_sdata);
285 	sdata2 = rcu_dereference(local->sched_scan_sdata);
286 
287 	if (likely(!sdata1 && !sdata2))
288 		return;
289 
290 	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
291 		/*
292 		 * we were passive scanning because of radar/no-IR, but
293 		 * the beacon/proberesp rx gives us an opportunity to upgrade
294 		 * to active scan
295 		 */
296 		set_bit(SCAN_BEACON_DONE, &local->scanning);
297 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
298 	}
299 
300 	channel = ieee80211_get_channel_khz(local->hw.wiphy,
301 					    ieee80211_rx_status_to_khz(rx_status));
302 
303 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
304 		return;
305 
306 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
307 		struct cfg80211_scan_request *scan_req;
308 		struct cfg80211_sched_scan_request *sched_scan_req;
309 		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
310 
311 		scan_req = rcu_dereference(local->scan_req);
312 		sched_scan_req = rcu_dereference(local->sched_scan_req);
313 
314 		if (scan_req)
315 			scan_req_flags = scan_req->flags;
316 
317 		if (sched_scan_req)
318 			sched_scan_req_flags = sched_scan_req->flags;
319 
320 		/* ignore ProbeResp to foreign address or non-bcast (OCE)
321 		 * unless scanning with randomised address
322 		 */
323 		if (!ieee80211_scan_accept_presp(sdata1, channel,
324 						 scan_req_flags,
325 						 mgmt->da) &&
326 		    !ieee80211_scan_accept_presp(sdata2, channel,
327 						 sched_scan_req_flags,
328 						 mgmt->da))
329 			return;
330 	}
331 
332 	bss = ieee80211_bss_info_update(local, rx_status,
333 					mgmt, skb->len,
334 					channel);
335 	if (bss)
336 		ieee80211_rx_bss_put(local, bss);
337 }
338 
339 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
340 {
341 	memset(chandef, 0, sizeof(*chandef));
342 
343 	chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
344 }
345 
346 /* return false if no more work */
347 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
348 {
349 	struct ieee80211_local *local = sdata->local;
350 	struct cfg80211_scan_request *req;
351 	struct cfg80211_chan_def chandef;
352 	u8 bands_used = 0;
353 	int i, ielen, n_chans;
354 	u32 flags = 0;
355 
356 	req = rcu_dereference_protected(local->scan_req,
357 					lockdep_is_held(&local->hw.wiphy->mtx));
358 
359 	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
360 		return false;
361 
362 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
363 		for (i = 0; i < req->n_channels; i++) {
364 			local->hw_scan_req->req.channels[i] = req->channels[i];
365 			bands_used |= BIT(req->channels[i]->band);
366 		}
367 
368 		n_chans = req->n_channels;
369 	} else {
370 		do {
371 			if (local->hw_scan_band == NUM_NL80211_BANDS)
372 				return false;
373 
374 			n_chans = 0;
375 
376 			for (i = 0; i < req->n_channels; i++) {
377 				if (req->channels[i]->band !=
378 				    local->hw_scan_band)
379 					continue;
380 				local->hw_scan_req->req.channels[n_chans] =
381 							req->channels[i];
382 				n_chans++;
383 				bands_used |= BIT(req->channels[i]->band);
384 			}
385 
386 			local->hw_scan_band++;
387 		} while (!n_chans);
388 	}
389 
390 	local->hw_scan_req->req.n_channels = n_chans;
391 	ieee80211_prepare_scan_chandef(&chandef);
392 
393 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
394 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
395 
396 	ielen = ieee80211_build_preq_ies(sdata,
397 					 (u8 *)local->hw_scan_req->req.ie,
398 					 local->hw_scan_ies_bufsize,
399 					 &local->hw_scan_req->ies,
400 					 req->ie, req->ie_len,
401 					 bands_used, req->rates, &chandef,
402 					 flags);
403 	if (ielen < 0)
404 		return false;
405 	local->hw_scan_req->req.ie_len = ielen;
406 	local->hw_scan_req->req.no_cck = req->no_cck;
407 	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
408 	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
409 			req->mac_addr_mask);
410 	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
411 
412 	return true;
413 }
414 
415 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
416 {
417 	struct ieee80211_local *local = hw_to_local(hw);
418 	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
419 	bool was_scanning = local->scanning;
420 	struct cfg80211_scan_request *scan_req;
421 	struct ieee80211_sub_if_data *scan_sdata;
422 	struct ieee80211_sub_if_data *sdata;
423 
424 	lockdep_assert_wiphy(local->hw.wiphy);
425 
426 	/*
427 	 * It's ok to abort a not-yet-running scan (that
428 	 * we have one at all will be verified by checking
429 	 * local->scan_req next), but not to complete it
430 	 * successfully.
431 	 */
432 	if (WARN_ON(!local->scanning && !aborted))
433 		aborted = true;
434 
435 	if (WARN_ON(!local->scan_req))
436 		return;
437 
438 	scan_sdata = rcu_dereference_protected(local->scan_sdata,
439 					       lockdep_is_held(&local->hw.wiphy->mtx));
440 
441 	if (hw_scan && !aborted &&
442 	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
443 	    ieee80211_prep_hw_scan(scan_sdata)) {
444 		int rc;
445 
446 		rc = drv_hw_scan(local,
447 			rcu_dereference_protected(local->scan_sdata,
448 						  lockdep_is_held(&local->hw.wiphy->mtx)),
449 			local->hw_scan_req);
450 
451 		if (rc == 0)
452 			return;
453 
454 		/* HW scan failed and is going to be reported as aborted,
455 		 * so clear old scan info.
456 		 */
457 		memset(&local->scan_info, 0, sizeof(local->scan_info));
458 		aborted = true;
459 	}
460 
461 	kfree(local->hw_scan_req);
462 	local->hw_scan_req = NULL;
463 
464 	scan_req = rcu_dereference_protected(local->scan_req,
465 					     lockdep_is_held(&local->hw.wiphy->mtx));
466 
467 	RCU_INIT_POINTER(local->scan_req, NULL);
468 	RCU_INIT_POINTER(local->scan_sdata, NULL);
469 
470 	local->scanning = 0;
471 	local->scan_chandef.chan = NULL;
472 
473 	synchronize_rcu();
474 
475 	if (scan_req != local->int_scan_req) {
476 		local->scan_info.aborted = aborted;
477 		cfg80211_scan_done(scan_req, &local->scan_info);
478 	}
479 
480 	/* Set power back to normal operating levels. */
481 	ieee80211_hw_conf_chan(local);
482 
483 	if (!hw_scan && was_scanning) {
484 		ieee80211_configure_filter(local);
485 		drv_sw_scan_complete(local, scan_sdata);
486 		ieee80211_offchannel_return(local);
487 	}
488 
489 	ieee80211_recalc_idle(local);
490 
491 	ieee80211_mlme_notify_scan_completed(local);
492 	ieee80211_ibss_notify_scan_completed(local);
493 
494 	/* Requeue all the work that might have been ignored while
495 	 * the scan was in progress; if there was none this will
496 	 * just be a no-op for the particular interface.
497 	 */
498 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
499 		if (ieee80211_sdata_running(sdata))
500 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
501 	}
502 
503 	if (was_scanning)
504 		ieee80211_start_next_roc(local);
505 }
506 
507 void ieee80211_scan_completed(struct ieee80211_hw *hw,
508 			      struct cfg80211_scan_info *info)
509 {
510 	struct ieee80211_local *local = hw_to_local(hw);
511 
512 	trace_api_scan_completed(local, info->aborted);
513 
514 	set_bit(SCAN_COMPLETED, &local->scanning);
515 	if (info->aborted)
516 		set_bit(SCAN_ABORTED, &local->scanning);
517 
518 	memcpy(&local->scan_info, info, sizeof(*info));
519 
520 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
521 }
522 EXPORT_SYMBOL(ieee80211_scan_completed);
523 
524 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
525 				   struct ieee80211_sub_if_data *sdata)
526 {
527 	/* Software scan is not supported in multi-channel cases */
528 	if (!local->emulate_chanctx)
529 		return -EOPNOTSUPP;
530 
531 	/*
532 	 * Hardware/driver doesn't support hw_scan, so use software
533 	 * scanning instead. First send a nullfunc frame with power save
534 	 * bit on so that AP will buffer the frames for us while we are not
535 	 * listening, then send probe requests to each channel and wait for
536 	 * the responses. After all channels are scanned, tune back to the
537 	 * original channel and send a nullfunc frame with power save bit
538 	 * off to trigger the AP to send us all the buffered frames.
539 	 *
540 	 * Note that while local->sw_scanning is true everything else but
541 	 * nullfunc frames and probe requests will be dropped in
542 	 * ieee80211_tx_h_check_assoc().
543 	 */
544 	drv_sw_scan_start(local, sdata, local->scan_addr);
545 
546 	local->leave_oper_channel_time = jiffies;
547 	local->next_scan_state = SCAN_DECISION;
548 	local->scan_channel_idx = 0;
549 
550 	ieee80211_offchannel_stop_vifs(local);
551 
552 	/* ensure nullfunc is transmitted before leaving operating channel */
553 	ieee80211_flush_queues(local, NULL, false);
554 
555 	ieee80211_configure_filter(local);
556 
557 	/* We need to set power level at maximum rate for scanning. */
558 	ieee80211_hw_conf_chan(local);
559 
560 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
561 
562 	return 0;
563 }
564 
565 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
566 {
567 	struct ieee80211_local *local = sdata->local;
568 	struct ieee80211_sub_if_data *sdata_iter;
569 
570 	lockdep_assert_wiphy(local->hw.wiphy);
571 
572 	if (!ieee80211_is_radar_required(local))
573 		return true;
574 
575 	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
576 		return false;
577 
578 	list_for_each_entry(sdata_iter, &local->interfaces, list) {
579 		if (sdata_iter->wdev.cac_started)
580 			return false;
581 	}
582 
583 	return true;
584 }
585 
586 static bool ieee80211_can_scan(struct ieee80211_local *local,
587 			       struct ieee80211_sub_if_data *sdata)
588 {
589 	if (!__ieee80211_can_leave_ch(sdata))
590 		return false;
591 
592 	if (!list_empty(&local->roc_list))
593 		return false;
594 
595 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
596 	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
597 		return false;
598 
599 	return true;
600 }
601 
602 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
603 {
604 	lockdep_assert_wiphy(local->hw.wiphy);
605 
606 	if (!local->scan_req || local->scanning)
607 		return;
608 
609 	if (!ieee80211_can_scan(local,
610 				rcu_dereference_protected(
611 					local->scan_sdata,
612 					lockdep_is_held(&local->hw.wiphy->mtx))))
613 		return;
614 
615 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
616 				 round_jiffies_relative(0));
617 }
618 
619 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
620 					  const u8 *src, const u8 *dst,
621 					  const u8 *ssid, size_t ssid_len,
622 					  const u8 *ie, size_t ie_len,
623 					  u32 ratemask, u32 flags, u32 tx_flags,
624 					  struct ieee80211_channel *channel)
625 {
626 	struct sk_buff *skb;
627 
628 	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
629 					ssid, ssid_len,
630 					ie, ie_len, flags);
631 
632 	if (skb) {
633 		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
634 			struct ieee80211_hdr *hdr = (void *)skb->data;
635 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
636 			u16 sn = get_random_u16();
637 
638 			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
639 			hdr->seq_ctrl =
640 				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
641 		}
642 		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
643 		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
644 	}
645 }
646 
647 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
648 					    unsigned long *next_delay)
649 {
650 	int i;
651 	struct ieee80211_sub_if_data *sdata;
652 	struct cfg80211_scan_request *scan_req;
653 	enum nl80211_band band = local->hw.conf.chandef.chan->band;
654 	u32 flags = 0, tx_flags;
655 
656 	scan_req = rcu_dereference_protected(local->scan_req,
657 					     lockdep_is_held(&local->hw.wiphy->mtx));
658 
659 	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
660 	if (scan_req->no_cck)
661 		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
662 	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
663 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
664 	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
665 		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
666 
667 	sdata = rcu_dereference_protected(local->scan_sdata,
668 					  lockdep_is_held(&local->hw.wiphy->mtx));
669 
670 	for (i = 0; i < scan_req->n_ssids; i++)
671 		ieee80211_send_scan_probe_req(
672 			sdata, local->scan_addr, scan_req->bssid,
673 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
674 			scan_req->ie, scan_req->ie_len,
675 			scan_req->rates[band], flags,
676 			tx_flags, local->hw.conf.chandef.chan);
677 
678 	/*
679 	 * After sending probe requests, wait for probe responses
680 	 * on the channel.
681 	 */
682 	*next_delay = msecs_to_jiffies(scan_req->duration) >
683 		      IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
684 		      msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
685 		      IEEE80211_CHANNEL_TIME;
686 	local->next_scan_state = SCAN_DECISION;
687 }
688 
689 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
690 				  struct cfg80211_scan_request *req)
691 {
692 	struct ieee80211_local *local = sdata->local;
693 	bool hw_scan = local->ops->hw_scan;
694 	int rc;
695 
696 	lockdep_assert_wiphy(local->hw.wiphy);
697 
698 	if (local->scan_req)
699 		return -EBUSY;
700 
701 	/* For an MLO connection, if a link ID was specified, validate that it
702 	 * is indeed active. If no link ID was specified, select one of the
703 	 * active links.
704 	 */
705 	if (ieee80211_vif_is_mld(&sdata->vif)) {
706 		if (req->tsf_report_link_id >= 0) {
707 			if (!(sdata->vif.active_links &
708 			      BIT(req->tsf_report_link_id)))
709 				return -EINVAL;
710 		} else {
711 			req->tsf_report_link_id =
712 				__ffs(sdata->vif.active_links);
713 		}
714 	}
715 
716 	if (!__ieee80211_can_leave_ch(sdata))
717 		return -EBUSY;
718 
719 	if (!ieee80211_can_scan(local, sdata)) {
720 		/* wait for the work to finish/time out */
721 		rcu_assign_pointer(local->scan_req, req);
722 		rcu_assign_pointer(local->scan_sdata, sdata);
723 		return 0;
724 	}
725 
726  again:
727 	if (hw_scan) {
728 		u8 *ies;
729 
730 		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
731 
732 		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
733 			int i, n_bands = 0;
734 			u8 bands_counted = 0;
735 
736 			for (i = 0; i < req->n_channels; i++) {
737 				if (bands_counted & BIT(req->channels[i]->band))
738 					continue;
739 				bands_counted |= BIT(req->channels[i]->band);
740 				n_bands++;
741 			}
742 
743 			local->hw_scan_ies_bufsize *= n_bands;
744 		}
745 
746 		local->hw_scan_req = kmalloc(
747 				sizeof(*local->hw_scan_req) +
748 				req->n_channels * sizeof(req->channels[0]) +
749 				local->hw_scan_ies_bufsize, GFP_KERNEL);
750 		if (!local->hw_scan_req)
751 			return -ENOMEM;
752 
753 		local->hw_scan_req->req.ssids = req->ssids;
754 		local->hw_scan_req->req.n_ssids = req->n_ssids;
755 		ies = (u8 *)local->hw_scan_req +
756 			sizeof(*local->hw_scan_req) +
757 			req->n_channels * sizeof(req->channels[0]);
758 		local->hw_scan_req->req.ie = ies;
759 		local->hw_scan_req->req.flags = req->flags;
760 		eth_broadcast_addr(local->hw_scan_req->req.bssid);
761 		local->hw_scan_req->req.duration = req->duration;
762 		local->hw_scan_req->req.duration_mandatory =
763 			req->duration_mandatory;
764 		local->hw_scan_req->req.tsf_report_link_id =
765 			req->tsf_report_link_id;
766 
767 		local->hw_scan_band = 0;
768 		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
769 		local->hw_scan_req->req.scan_6ghz_params =
770 			req->scan_6ghz_params;
771 		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
772 
773 		/*
774 		 * After allocating local->hw_scan_req, we must
775 		 * go through until ieee80211_prep_hw_scan(), so
776 		 * anything that might be changed here and leave
777 		 * this function early must not go after this
778 		 * allocation.
779 		 */
780 	}
781 
782 	rcu_assign_pointer(local->scan_req, req);
783 	rcu_assign_pointer(local->scan_sdata, sdata);
784 
785 	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
786 		get_random_mask_addr(local->scan_addr,
787 				     req->mac_addr,
788 				     req->mac_addr_mask);
789 	else
790 		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
791 
792 	if (hw_scan) {
793 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
794 	} else if ((req->n_channels == 1) &&
795 		   (req->channels[0] == local->hw.conf.chandef.chan)) {
796 		/*
797 		 * If we are scanning only on the operating channel
798 		 * then we do not need to stop normal activities
799 		 */
800 		unsigned long next_delay;
801 
802 		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
803 
804 		ieee80211_recalc_idle(local);
805 
806 		/* Notify driver scan is starting, keep order of operations
807 		 * same as normal software scan, in case that matters. */
808 		drv_sw_scan_start(local, sdata, local->scan_addr);
809 
810 		ieee80211_configure_filter(local); /* accept probe-responses */
811 
812 		/* We need to ensure power level is at max for scanning. */
813 		ieee80211_hw_conf_chan(local);
814 
815 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
816 						IEEE80211_CHAN_RADAR)) ||
817 		    !req->n_ssids) {
818 			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
819 			if (req->n_ssids)
820 				set_bit(SCAN_BEACON_WAIT, &local->scanning);
821 		} else {
822 			ieee80211_scan_state_send_probe(local, &next_delay);
823 			next_delay = IEEE80211_CHANNEL_TIME;
824 		}
825 
826 		/* Now, just wait a bit and we are all done! */
827 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
828 					 next_delay);
829 		return 0;
830 	} else {
831 		/* Do normal software scan */
832 		__set_bit(SCAN_SW_SCANNING, &local->scanning);
833 	}
834 
835 	ieee80211_recalc_idle(local);
836 
837 	if (hw_scan) {
838 		WARN_ON(!ieee80211_prep_hw_scan(sdata));
839 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
840 	} else {
841 		rc = ieee80211_start_sw_scan(local, sdata);
842 	}
843 
844 	if (rc) {
845 		kfree(local->hw_scan_req);
846 		local->hw_scan_req = NULL;
847 		local->scanning = 0;
848 
849 		ieee80211_recalc_idle(local);
850 
851 		local->scan_req = NULL;
852 		RCU_INIT_POINTER(local->scan_sdata, NULL);
853 	}
854 
855 	if (hw_scan && rc == 1) {
856 		/*
857 		 * we can't fall back to software for P2P-GO
858 		 * as it must update NoA etc.
859 		 */
860 		if (ieee80211_vif_type_p2p(&sdata->vif) ==
861 				NL80211_IFTYPE_P2P_GO)
862 			return -EOPNOTSUPP;
863 		hw_scan = false;
864 		goto again;
865 	}
866 
867 	return rc;
868 }
869 
870 static unsigned long
871 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
872 {
873 	/*
874 	 * TODO: channel switching also consumes quite some time,
875 	 * add that delay as well to get a better estimation
876 	 */
877 	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
878 		return IEEE80211_PASSIVE_CHANNEL_TIME;
879 	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
880 }
881 
882 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
883 					  unsigned long *next_delay)
884 {
885 	bool associated = false;
886 	bool tx_empty = true;
887 	bool bad_latency;
888 	struct ieee80211_sub_if_data *sdata;
889 	struct ieee80211_channel *next_chan;
890 	enum mac80211_scan_state next_scan_state;
891 	struct cfg80211_scan_request *scan_req;
892 
893 	lockdep_assert_wiphy(local->hw.wiphy);
894 
895 	/*
896 	 * check if at least one STA interface is associated,
897 	 * check if at least one STA interface has pending tx frames
898 	 * and grab the lowest used beacon interval
899 	 */
900 	list_for_each_entry(sdata, &local->interfaces, list) {
901 		if (!ieee80211_sdata_running(sdata))
902 			continue;
903 
904 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
905 			if (sdata->u.mgd.associated) {
906 				associated = true;
907 
908 				if (!qdisc_all_tx_empty(sdata->dev)) {
909 					tx_empty = false;
910 					break;
911 				}
912 			}
913 		}
914 	}
915 
916 	scan_req = rcu_dereference_protected(local->scan_req,
917 					     lockdep_is_held(&local->hw.wiphy->mtx));
918 
919 	next_chan = scan_req->channels[local->scan_channel_idx];
920 
921 	/*
922 	 * we're currently scanning a different channel, let's
923 	 * see if we can scan another channel without interfering
924 	 * with the current traffic situation.
925 	 *
926 	 * Keep good latency, do not stay off-channel more than 125 ms.
927 	 */
928 
929 	bad_latency = time_after(jiffies +
930 				 ieee80211_scan_get_channel_time(next_chan),
931 				 local->leave_oper_channel_time + HZ / 8);
932 
933 	if (associated && !tx_empty) {
934 		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
935 			next_scan_state = SCAN_ABORT;
936 		else
937 			next_scan_state = SCAN_SUSPEND;
938 	} else if (associated && bad_latency) {
939 		next_scan_state = SCAN_SUSPEND;
940 	} else {
941 		next_scan_state = SCAN_SET_CHANNEL;
942 	}
943 
944 	local->next_scan_state = next_scan_state;
945 
946 	*next_delay = 0;
947 }
948 
949 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
950 					     unsigned long *next_delay)
951 {
952 	int skip;
953 	struct ieee80211_channel *chan;
954 	struct cfg80211_scan_request *scan_req;
955 
956 	scan_req = rcu_dereference_protected(local->scan_req,
957 					     lockdep_is_held(&local->hw.wiphy->mtx));
958 
959 	skip = 0;
960 	chan = scan_req->channels[local->scan_channel_idx];
961 
962 	local->scan_chandef.chan = chan;
963 	local->scan_chandef.center_freq1 = chan->center_freq;
964 	local->scan_chandef.freq1_offset = chan->freq_offset;
965 	local->scan_chandef.center_freq2 = 0;
966 
967 	/* For scanning on the S1G band, detect the channel width according to
968 	 * the channel being scanned.
969 	 */
970 	if (chan->band == NL80211_BAND_S1GHZ) {
971 		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
972 		goto set_channel;
973 	}
974 
975 	/* If scanning on oper channel, use whatever channel-type
976 	 * is currently in use.
977 	 */
978 	if (chan == local->hw.conf.chandef.chan)
979 		local->scan_chandef = local->hw.conf.chandef;
980 	else
981 		local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
982 
983 set_channel:
984 	if (ieee80211_hw_conf_chan(local))
985 		skip = 1;
986 
987 	/* advance state machine to next channel/band */
988 	local->scan_channel_idx++;
989 
990 	if (skip) {
991 		/* if we skip this channel return to the decision state */
992 		local->next_scan_state = SCAN_DECISION;
993 		return;
994 	}
995 
996 	/*
997 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
998 	 * (which unfortunately doesn't say _why_ step a) is done,
999 	 * but it waits for the probe delay or until a frame is
1000 	 * received - and the received frame would update the NAV).
1001 	 * For now, we do not support waiting until a frame is
1002 	 * received.
1003 	 *
1004 	 * In any case, it is not necessary for a passive scan.
1005 	 */
1006 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1007 	    !scan_req->n_ssids) {
1008 		*next_delay = msecs_to_jiffies(scan_req->duration) >
1009 			      IEEE80211_PASSIVE_CHANNEL_TIME ?
1010 			      msecs_to_jiffies(scan_req->duration) :
1011 			      IEEE80211_PASSIVE_CHANNEL_TIME;
1012 		local->next_scan_state = SCAN_DECISION;
1013 		if (scan_req->n_ssids)
1014 			set_bit(SCAN_BEACON_WAIT, &local->scanning);
1015 		return;
1016 	}
1017 
1018 	/* active scan, send probes */
1019 	*next_delay = IEEE80211_PROBE_DELAY;
1020 	local->next_scan_state = SCAN_SEND_PROBE;
1021 }
1022 
1023 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1024 					 unsigned long *next_delay)
1025 {
1026 	/* switch back to the operating channel */
1027 	local->scan_chandef.chan = NULL;
1028 	ieee80211_hw_conf_chan(local);
1029 
1030 	/* disable PS */
1031 	ieee80211_offchannel_return(local);
1032 
1033 	*next_delay = HZ / 5;
1034 	/* afterwards, resume scan & go to next channel */
1035 	local->next_scan_state = SCAN_RESUME;
1036 }
1037 
1038 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1039 					unsigned long *next_delay)
1040 {
1041 	ieee80211_offchannel_stop_vifs(local);
1042 
1043 	if (local->ops->flush) {
1044 		ieee80211_flush_queues(local, NULL, false);
1045 		*next_delay = 0;
1046 	} else
1047 		*next_delay = HZ / 10;
1048 
1049 	/* remember when we left the operating channel */
1050 	local->leave_oper_channel_time = jiffies;
1051 
1052 	/* advance to the next channel to be scanned */
1053 	local->next_scan_state = SCAN_SET_CHANNEL;
1054 }
1055 
1056 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1057 {
1058 	struct ieee80211_local *local =
1059 		container_of(work, struct ieee80211_local, scan_work.work);
1060 	struct ieee80211_sub_if_data *sdata;
1061 	struct cfg80211_scan_request *scan_req;
1062 	unsigned long next_delay = 0;
1063 	bool aborted;
1064 
1065 	lockdep_assert_wiphy(local->hw.wiphy);
1066 
1067 	if (!ieee80211_can_run_worker(local)) {
1068 		aborted = true;
1069 		goto out_complete;
1070 	}
1071 
1072 	sdata = rcu_dereference_protected(local->scan_sdata,
1073 					  lockdep_is_held(&local->hw.wiphy->mtx));
1074 	scan_req = rcu_dereference_protected(local->scan_req,
1075 					     lockdep_is_held(&local->hw.wiphy->mtx));
1076 
1077 	/* When scanning on-channel, the first-callback means completed. */
1078 	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1079 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1080 		goto out_complete;
1081 	}
1082 
1083 	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1084 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1085 		goto out_complete;
1086 	}
1087 
1088 	if (!sdata || !scan_req)
1089 		return;
1090 
1091 	if (!local->scanning) {
1092 		int rc;
1093 
1094 		RCU_INIT_POINTER(local->scan_req, NULL);
1095 		RCU_INIT_POINTER(local->scan_sdata, NULL);
1096 
1097 		rc = __ieee80211_start_scan(sdata, scan_req);
1098 		if (!rc)
1099 			return;
1100 		/* need to complete scan in cfg80211 */
1101 		rcu_assign_pointer(local->scan_req, scan_req);
1102 		aborted = true;
1103 		goto out_complete;
1104 	}
1105 
1106 	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1107 
1108 	/*
1109 	 * as long as no delay is required advance immediately
1110 	 * without scheduling a new work
1111 	 */
1112 	do {
1113 		if (!ieee80211_sdata_running(sdata)) {
1114 			aborted = true;
1115 			goto out_complete;
1116 		}
1117 
1118 		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1119 		    local->next_scan_state == SCAN_DECISION)
1120 			local->next_scan_state = SCAN_SEND_PROBE;
1121 
1122 		switch (local->next_scan_state) {
1123 		case SCAN_DECISION:
1124 			/* if no more bands/channels left, complete scan */
1125 			if (local->scan_channel_idx >= scan_req->n_channels) {
1126 				aborted = false;
1127 				goto out_complete;
1128 			}
1129 			ieee80211_scan_state_decision(local, &next_delay);
1130 			break;
1131 		case SCAN_SET_CHANNEL:
1132 			ieee80211_scan_state_set_channel(local, &next_delay);
1133 			break;
1134 		case SCAN_SEND_PROBE:
1135 			ieee80211_scan_state_send_probe(local, &next_delay);
1136 			break;
1137 		case SCAN_SUSPEND:
1138 			ieee80211_scan_state_suspend(local, &next_delay);
1139 			break;
1140 		case SCAN_RESUME:
1141 			ieee80211_scan_state_resume(local, &next_delay);
1142 			break;
1143 		case SCAN_ABORT:
1144 			aborted = true;
1145 			goto out_complete;
1146 		}
1147 	} while (next_delay == 0);
1148 
1149 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1150 				 next_delay);
1151 	return;
1152 
1153 out_complete:
1154 	__ieee80211_scan_completed(&local->hw, aborted);
1155 }
1156 
1157 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1158 			   struct cfg80211_scan_request *req)
1159 {
1160 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1161 
1162 	return __ieee80211_start_scan(sdata, req);
1163 }
1164 
1165 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1166 				const u8 *ssid, u8 ssid_len,
1167 				struct ieee80211_channel **channels,
1168 				unsigned int n_channels)
1169 {
1170 	struct ieee80211_local *local = sdata->local;
1171 	int ret = -EBUSY, i, n_ch = 0;
1172 	enum nl80211_band band;
1173 
1174 	lockdep_assert_wiphy(local->hw.wiphy);
1175 
1176 	/* busy scanning */
1177 	if (local->scan_req)
1178 		goto unlock;
1179 
1180 	/* fill internal scan request */
1181 	if (!channels) {
1182 		int max_n;
1183 
1184 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1185 			if (!local->hw.wiphy->bands[band] ||
1186 			    band == NL80211_BAND_6GHZ)
1187 				continue;
1188 
1189 			max_n = local->hw.wiphy->bands[band]->n_channels;
1190 			for (i = 0; i < max_n; i++) {
1191 				struct ieee80211_channel *tmp_ch =
1192 				    &local->hw.wiphy->bands[band]->channels[i];
1193 
1194 				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1195 						     IEEE80211_CHAN_DISABLED))
1196 					continue;
1197 
1198 				local->int_scan_req->channels[n_ch] = tmp_ch;
1199 				n_ch++;
1200 			}
1201 		}
1202 
1203 		if (WARN_ON_ONCE(n_ch == 0))
1204 			goto unlock;
1205 
1206 		local->int_scan_req->n_channels = n_ch;
1207 	} else {
1208 		for (i = 0; i < n_channels; i++) {
1209 			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1210 						  IEEE80211_CHAN_DISABLED))
1211 				continue;
1212 
1213 			local->int_scan_req->channels[n_ch] = channels[i];
1214 			n_ch++;
1215 		}
1216 
1217 		if (WARN_ON_ONCE(n_ch == 0))
1218 			goto unlock;
1219 
1220 		local->int_scan_req->n_channels = n_ch;
1221 	}
1222 
1223 	local->int_scan_req->ssids = &local->scan_ssid;
1224 	local->int_scan_req->n_ssids = 1;
1225 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1226 	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1227 
1228 	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1229  unlock:
1230 	return ret;
1231 }
1232 
1233 void ieee80211_scan_cancel(struct ieee80211_local *local)
1234 {
1235 	/* ensure a new scan cannot be queued */
1236 	lockdep_assert_wiphy(local->hw.wiphy);
1237 
1238 	/*
1239 	 * We are canceling software scan, or deferred scan that was not
1240 	 * yet really started (see __ieee80211_start_scan ).
1241 	 *
1242 	 * Regarding hardware scan:
1243 	 * - we can not call  __ieee80211_scan_completed() as when
1244 	 *   SCAN_HW_SCANNING bit is set this function change
1245 	 *   local->hw_scan_req to operate on 5G band, what race with
1246 	 *   driver which can use local->hw_scan_req
1247 	 *
1248 	 * - we can not cancel scan_work since driver can schedule it
1249 	 *   by ieee80211_scan_completed(..., true) to finish scan
1250 	 *
1251 	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1252 	 * driver is still responsible for calling ieee80211_scan_completed()
1253 	 * after the scan was completed/aborted.
1254 	 */
1255 
1256 	if (!local->scan_req)
1257 		return;
1258 
1259 	/*
1260 	 * We have a scan running and the driver already reported completion,
1261 	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1262 	 * cancelled.
1263 	 */
1264 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1265 	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1266 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1267 		return;
1268 	}
1269 
1270 	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1271 		/*
1272 		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1273 		 * scan on another band.
1274 		 */
1275 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1276 		if (local->ops->cancel_hw_scan)
1277 			drv_cancel_hw_scan(local,
1278 				rcu_dereference_protected(local->scan_sdata,
1279 						lockdep_is_held(&local->hw.wiphy->mtx)));
1280 		return;
1281 	}
1282 
1283 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1284 	/* and clean up */
1285 	memset(&local->scan_info, 0, sizeof(local->scan_info));
1286 	__ieee80211_scan_completed(&local->hw, true);
1287 }
1288 
1289 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1290 					struct cfg80211_sched_scan_request *req)
1291 {
1292 	struct ieee80211_local *local = sdata->local;
1293 	struct ieee80211_scan_ies sched_scan_ies = {};
1294 	struct cfg80211_chan_def chandef;
1295 	int ret, i, iebufsz, num_bands = 0;
1296 	u32 rate_masks[NUM_NL80211_BANDS] = {};
1297 	u8 bands_used = 0;
1298 	u8 *ie;
1299 	u32 flags = 0;
1300 
1301 	lockdep_assert_wiphy(local->hw.wiphy);
1302 
1303 	iebufsz = local->scan_ies_len + req->ie_len;
1304 
1305 	if (!local->ops->sched_scan_start)
1306 		return -EOPNOTSUPP;
1307 
1308 	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1309 		if (local->hw.wiphy->bands[i]) {
1310 			bands_used |= BIT(i);
1311 			rate_masks[i] = (u32) -1;
1312 			num_bands++;
1313 		}
1314 	}
1315 
1316 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1317 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1318 
1319 	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1320 	if (!ie) {
1321 		ret = -ENOMEM;
1322 		goto out;
1323 	}
1324 
1325 	ieee80211_prepare_scan_chandef(&chandef);
1326 
1327 	ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1328 				       &sched_scan_ies, req->ie,
1329 				       req->ie_len, bands_used, rate_masks,
1330 				       &chandef, flags);
1331 	if (ret < 0)
1332 		goto error;
1333 
1334 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1335 	if (ret == 0) {
1336 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1337 		rcu_assign_pointer(local->sched_scan_req, req);
1338 	}
1339 
1340 error:
1341 	kfree(ie);
1342 out:
1343 	if (ret) {
1344 		/* Clean in case of failure after HW restart or upon resume. */
1345 		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1346 		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1347 	}
1348 
1349 	return ret;
1350 }
1351 
1352 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1353 				       struct cfg80211_sched_scan_request *req)
1354 {
1355 	struct ieee80211_local *local = sdata->local;
1356 
1357 	lockdep_assert_wiphy(local->hw.wiphy);
1358 
1359 	if (rcu_access_pointer(local->sched_scan_sdata))
1360 		return -EBUSY;
1361 
1362 	return __ieee80211_request_sched_scan_start(sdata, req);
1363 }
1364 
1365 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1366 {
1367 	struct ieee80211_sub_if_data *sched_scan_sdata;
1368 	int ret = -ENOENT;
1369 
1370 	lockdep_assert_wiphy(local->hw.wiphy);
1371 
1372 	if (!local->ops->sched_scan_stop)
1373 		return -EOPNOTSUPP;
1374 
1375 	/* We don't want to restart sched scan anymore. */
1376 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1377 
1378 	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1379 						lockdep_is_held(&local->hw.wiphy->mtx));
1380 	if (sched_scan_sdata) {
1381 		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1382 		if (!ret)
1383 			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1384 	}
1385 
1386 	return ret;
1387 }
1388 
1389 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1390 {
1391 	struct ieee80211_local *local = hw_to_local(hw);
1392 
1393 	trace_api_sched_scan_results(local);
1394 
1395 	cfg80211_sched_scan_results(hw->wiphy, 0);
1396 }
1397 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1398 
1399 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1400 {
1401 	lockdep_assert_wiphy(local->hw.wiphy);
1402 
1403 	if (!rcu_access_pointer(local->sched_scan_sdata))
1404 		return;
1405 
1406 	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1407 
1408 	/* If sched scan was aborted by the driver. */
1409 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1410 
1411 	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1412 }
1413 
1414 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1415 				       struct wiphy_work *work)
1416 {
1417 	struct ieee80211_local *local =
1418 		container_of(work, struct ieee80211_local,
1419 			     sched_scan_stopped_work);
1420 
1421 	ieee80211_sched_scan_end(local);
1422 }
1423 
1424 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1425 {
1426 	struct ieee80211_local *local = hw_to_local(hw);
1427 
1428 	trace_api_sched_scan_stopped(local);
1429 
1430 	/*
1431 	 * this shouldn't really happen, so for simplicity
1432 	 * simply ignore it, and let mac80211 reconfigure
1433 	 * the sched scan later on.
1434 	 */
1435 	if (local->in_reconfig)
1436 		return;
1437 
1438 	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1439 }
1440 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1441