xref: /linux/net/mac80211/scan.c (revision 95444b9eeb8c5c0330563931d70c61ca3b101548)
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_mgmt *mgmt = (void *)skb->data;
261 	struct ieee80211_bss *bss;
262 	struct ieee80211_channel *channel;
263 	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
264 				      u.probe_resp.variable);
265 
266 	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
267 	    !ieee80211_is_beacon(mgmt->frame_control) &&
268 	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
269 		return;
270 
271 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
272 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
273 			min_hdr_len = offsetof(struct ieee80211_ext,
274 					       u.s1g_short_beacon.variable);
275 		else
276 			min_hdr_len = offsetof(struct ieee80211_ext,
277 					       u.s1g_beacon);
278 	}
279 
280 	if (skb->len < min_hdr_len)
281 		return;
282 
283 	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
284 		/*
285 		 * we were passive scanning because of radar/no-IR, but
286 		 * the beacon/proberesp rx gives us an opportunity to upgrade
287 		 * to active scan
288 		 */
289 		set_bit(SCAN_BEACON_DONE, &local->scanning);
290 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
291 	}
292 
293 	channel = ieee80211_get_channel_khz(local->hw.wiphy,
294 					    ieee80211_rx_status_to_khz(rx_status));
295 
296 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
297 		return;
298 
299 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
300 		struct ieee80211_sub_if_data *sdata1, *sdata2;
301 		struct cfg80211_scan_request *scan_req;
302 		struct cfg80211_sched_scan_request *sched_scan_req;
303 		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
304 
305 		sdata1 = rcu_dereference(local->scan_sdata);
306 		sdata2 = rcu_dereference(local->sched_scan_sdata);
307 
308 		if (likely(!sdata1 && !sdata2))
309 			return;
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 	} else {
331 		/* Beacons are expected only with broadcast address */
332 		if (!is_broadcast_ether_addr(mgmt->da))
333 			return;
334 	}
335 
336 	/* Do not update the BSS table in case of only monitor interfaces */
337 	if (local->open_count == local->monitors)
338 		return;
339 
340 	bss = ieee80211_bss_info_update(local, rx_status,
341 					mgmt, skb->len,
342 					channel);
343 	if (bss)
344 		ieee80211_rx_bss_put(local, bss);
345 }
346 
347 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
348 {
349 	memset(chandef, 0, sizeof(*chandef));
350 
351 	chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
352 }
353 
354 /* return false if no more work */
355 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
356 {
357 	struct ieee80211_local *local = sdata->local;
358 	struct cfg80211_scan_request *req;
359 	struct cfg80211_chan_def chandef;
360 	u8 bands_used = 0;
361 	int i, ielen, n_chans;
362 	u32 flags = 0;
363 
364 	req = rcu_dereference_protected(local->scan_req,
365 					lockdep_is_held(&local->hw.wiphy->mtx));
366 
367 	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
368 		return false;
369 
370 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
371 		for (i = 0; i < req->n_channels; i++) {
372 			local->hw_scan_req->req.channels[i] = req->channels[i];
373 			bands_used |= BIT(req->channels[i]->band);
374 		}
375 
376 		n_chans = req->n_channels;
377 	} else {
378 		do {
379 			if (local->hw_scan_band == NUM_NL80211_BANDS)
380 				return false;
381 
382 			n_chans = 0;
383 
384 			for (i = 0; i < req->n_channels; i++) {
385 				if (req->channels[i]->band !=
386 				    local->hw_scan_band)
387 					continue;
388 				local->hw_scan_req->req.channels[n_chans] =
389 							req->channels[i];
390 				n_chans++;
391 				bands_used |= BIT(req->channels[i]->band);
392 			}
393 
394 			local->hw_scan_band++;
395 		} while (!n_chans);
396 	}
397 
398 	local->hw_scan_req->req.n_channels = n_chans;
399 	ieee80211_prepare_scan_chandef(&chandef);
400 
401 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
402 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
403 
404 	ielen = ieee80211_build_preq_ies(sdata,
405 					 (u8 *)local->hw_scan_req->req.ie,
406 					 local->hw_scan_ies_bufsize,
407 					 &local->hw_scan_req->ies,
408 					 req->ie, req->ie_len,
409 					 bands_used, req->rates, &chandef,
410 					 flags);
411 	if (ielen < 0)
412 		return false;
413 	local->hw_scan_req->req.ie_len = ielen;
414 	local->hw_scan_req->req.no_cck = req->no_cck;
415 	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
416 	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
417 			req->mac_addr_mask);
418 	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
419 
420 	return true;
421 }
422 
423 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
424 {
425 	struct ieee80211_local *local = hw_to_local(hw);
426 	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
427 	bool was_scanning = local->scanning;
428 	struct cfg80211_scan_request *scan_req;
429 	struct ieee80211_sub_if_data *scan_sdata;
430 	struct ieee80211_sub_if_data *sdata;
431 
432 	lockdep_assert_wiphy(local->hw.wiphy);
433 
434 	/*
435 	 * It's ok to abort a not-yet-running scan (that
436 	 * we have one at all will be verified by checking
437 	 * local->scan_req next), but not to complete it
438 	 * successfully.
439 	 */
440 	if (WARN_ON(!local->scanning && !aborted))
441 		aborted = true;
442 
443 	if (WARN_ON(!local->scan_req))
444 		return;
445 
446 	scan_sdata = rcu_dereference_protected(local->scan_sdata,
447 					       lockdep_is_held(&local->hw.wiphy->mtx));
448 
449 	if (hw_scan && !aborted &&
450 	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
451 	    ieee80211_prep_hw_scan(scan_sdata)) {
452 		int rc;
453 
454 		rc = drv_hw_scan(local,
455 			rcu_dereference_protected(local->scan_sdata,
456 						  lockdep_is_held(&local->hw.wiphy->mtx)),
457 			local->hw_scan_req);
458 
459 		if (rc == 0)
460 			return;
461 
462 		/* HW scan failed and is going to be reported as aborted,
463 		 * so clear old scan info.
464 		 */
465 		memset(&local->scan_info, 0, sizeof(local->scan_info));
466 		aborted = true;
467 	}
468 
469 	kfree(local->hw_scan_req);
470 	local->hw_scan_req = NULL;
471 
472 	scan_req = rcu_dereference_protected(local->scan_req,
473 					     lockdep_is_held(&local->hw.wiphy->mtx));
474 
475 	RCU_INIT_POINTER(local->scan_req, NULL);
476 	RCU_INIT_POINTER(local->scan_sdata, NULL);
477 
478 	local->scanning = 0;
479 	local->scan_chandef.chan = NULL;
480 
481 	synchronize_rcu();
482 
483 	if (scan_req != local->int_scan_req) {
484 		local->scan_info.aborted = aborted;
485 		cfg80211_scan_done(scan_req, &local->scan_info);
486 	}
487 
488 	/* Set power back to normal operating levels. */
489 	ieee80211_hw_conf_chan(local);
490 
491 	if (!hw_scan && was_scanning) {
492 		ieee80211_configure_filter(local);
493 		drv_sw_scan_complete(local, scan_sdata);
494 		ieee80211_offchannel_return(local);
495 	}
496 
497 	ieee80211_recalc_idle(local);
498 
499 	ieee80211_mlme_notify_scan_completed(local);
500 	ieee80211_ibss_notify_scan_completed(local);
501 
502 	/* Requeue all the work that might have been ignored while
503 	 * the scan was in progress; if there was none this will
504 	 * just be a no-op for the particular interface.
505 	 */
506 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
507 		if (ieee80211_sdata_running(sdata))
508 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
509 	}
510 
511 	if (was_scanning)
512 		ieee80211_start_next_roc(local);
513 }
514 
515 void ieee80211_scan_completed(struct ieee80211_hw *hw,
516 			      struct cfg80211_scan_info *info)
517 {
518 	struct ieee80211_local *local = hw_to_local(hw);
519 
520 	trace_api_scan_completed(local, info->aborted);
521 
522 	set_bit(SCAN_COMPLETED, &local->scanning);
523 	if (info->aborted)
524 		set_bit(SCAN_ABORTED, &local->scanning);
525 
526 	memcpy(&local->scan_info, info, sizeof(*info));
527 
528 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
529 }
530 EXPORT_SYMBOL(ieee80211_scan_completed);
531 
532 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
533 				   struct ieee80211_sub_if_data *sdata)
534 {
535 	/* Software scan is not supported in multi-channel cases */
536 	if (!local->emulate_chanctx)
537 		return -EOPNOTSUPP;
538 
539 	/*
540 	 * Hardware/driver doesn't support hw_scan, so use software
541 	 * scanning instead. First send a nullfunc frame with power save
542 	 * bit on so that AP will buffer the frames for us while we are not
543 	 * listening, then send probe requests to each channel and wait for
544 	 * the responses. After all channels are scanned, tune back to the
545 	 * original channel and send a nullfunc frame with power save bit
546 	 * off to trigger the AP to send us all the buffered frames.
547 	 *
548 	 * Note that while local->sw_scanning is true everything else but
549 	 * nullfunc frames and probe requests will be dropped in
550 	 * ieee80211_tx_h_check_assoc().
551 	 */
552 	drv_sw_scan_start(local, sdata, local->scan_addr);
553 
554 	local->leave_oper_channel_time = jiffies;
555 	local->next_scan_state = SCAN_DECISION;
556 	local->scan_channel_idx = 0;
557 
558 	ieee80211_offchannel_stop_vifs(local);
559 
560 	/* ensure nullfunc is transmitted before leaving operating channel */
561 	ieee80211_flush_queues(local, NULL, false);
562 
563 	ieee80211_configure_filter(local);
564 
565 	/* We need to set power level at maximum rate for scanning. */
566 	ieee80211_hw_conf_chan(local);
567 
568 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
569 
570 	return 0;
571 }
572 
573 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
574 {
575 	struct ieee80211_local *local = sdata->local;
576 	struct ieee80211_sub_if_data *sdata_iter;
577 
578 	lockdep_assert_wiphy(local->hw.wiphy);
579 
580 	if (!ieee80211_is_radar_required(local))
581 		return true;
582 
583 	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
584 		return false;
585 
586 	list_for_each_entry(sdata_iter, &local->interfaces, list) {
587 		if (sdata_iter->wdev.cac_started)
588 			return false;
589 	}
590 
591 	return true;
592 }
593 
594 static bool ieee80211_can_scan(struct ieee80211_local *local,
595 			       struct ieee80211_sub_if_data *sdata)
596 {
597 	if (!__ieee80211_can_leave_ch(sdata))
598 		return false;
599 
600 	if (!list_empty(&local->roc_list))
601 		return false;
602 
603 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
604 	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
605 		return false;
606 
607 	return true;
608 }
609 
610 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
611 {
612 	lockdep_assert_wiphy(local->hw.wiphy);
613 
614 	if (!local->scan_req || local->scanning)
615 		return;
616 
617 	if (!ieee80211_can_scan(local,
618 				rcu_dereference_protected(
619 					local->scan_sdata,
620 					lockdep_is_held(&local->hw.wiphy->mtx))))
621 		return;
622 
623 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
624 				 round_jiffies_relative(0));
625 }
626 
627 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
628 					  const u8 *src, const u8 *dst,
629 					  const u8 *ssid, size_t ssid_len,
630 					  const u8 *ie, size_t ie_len,
631 					  u32 ratemask, u32 flags, u32 tx_flags,
632 					  struct ieee80211_channel *channel)
633 {
634 	struct sk_buff *skb;
635 
636 	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
637 					ssid, ssid_len,
638 					ie, ie_len, flags);
639 
640 	if (skb) {
641 		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
642 			struct ieee80211_hdr *hdr = (void *)skb->data;
643 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
644 			u16 sn = get_random_u16();
645 
646 			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
647 			hdr->seq_ctrl =
648 				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
649 		}
650 		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
651 		IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_SCAN_TX;
652 		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
653 	}
654 }
655 
656 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
657 					    unsigned long *next_delay)
658 {
659 	int i;
660 	struct ieee80211_sub_if_data *sdata;
661 	struct cfg80211_scan_request *scan_req;
662 	enum nl80211_band band = local->hw.conf.chandef.chan->band;
663 	u32 flags = 0, tx_flags;
664 
665 	scan_req = rcu_dereference_protected(local->scan_req,
666 					     lockdep_is_held(&local->hw.wiphy->mtx));
667 
668 	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
669 	if (scan_req->no_cck)
670 		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
671 	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
672 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
673 	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
674 		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
675 
676 	sdata = rcu_dereference_protected(local->scan_sdata,
677 					  lockdep_is_held(&local->hw.wiphy->mtx));
678 
679 	for (i = 0; i < scan_req->n_ssids; i++)
680 		ieee80211_send_scan_probe_req(
681 			sdata, local->scan_addr, scan_req->bssid,
682 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
683 			scan_req->ie, scan_req->ie_len,
684 			scan_req->rates[band], flags,
685 			tx_flags, local->hw.conf.chandef.chan);
686 
687 	/*
688 	 * After sending probe requests, wait for probe responses
689 	 * on the channel.
690 	 */
691 	*next_delay = msecs_to_jiffies(scan_req->duration) >
692 		      IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
693 		      msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
694 		      IEEE80211_CHANNEL_TIME;
695 	local->next_scan_state = SCAN_DECISION;
696 }
697 
698 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
699 				  struct cfg80211_scan_request *req)
700 {
701 	struct ieee80211_local *local = sdata->local;
702 	bool hw_scan = local->ops->hw_scan;
703 	int rc;
704 
705 	lockdep_assert_wiphy(local->hw.wiphy);
706 
707 	if (local->scan_req)
708 		return -EBUSY;
709 
710 	/* For an MLO connection, if a link ID was specified, validate that it
711 	 * is indeed active.
712 	 */
713 	if (ieee80211_vif_is_mld(&sdata->vif) && req->tsf_report_link_id >= 0 &&
714 	    !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
715 		return -EINVAL;
716 
717 	if (!__ieee80211_can_leave_ch(sdata))
718 		return -EBUSY;
719 
720 	if (!ieee80211_can_scan(local, sdata)) {
721 		/* wait for the work to finish/time out */
722 		rcu_assign_pointer(local->scan_req, req);
723 		rcu_assign_pointer(local->scan_sdata, sdata);
724 		return 0;
725 	}
726 
727  again:
728 	if (hw_scan) {
729 		u8 *ies;
730 
731 		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
732 
733 		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
734 			int i, n_bands = 0;
735 			u8 bands_counted = 0;
736 
737 			for (i = 0; i < req->n_channels; i++) {
738 				if (bands_counted & BIT(req->channels[i]->band))
739 					continue;
740 				bands_counted |= BIT(req->channels[i]->band);
741 				n_bands++;
742 			}
743 
744 			local->hw_scan_ies_bufsize *= n_bands;
745 		}
746 
747 		local->hw_scan_req = kmalloc(
748 				sizeof(*local->hw_scan_req) +
749 				req->n_channels * sizeof(req->channels[0]) +
750 				local->hw_scan_ies_bufsize, GFP_KERNEL);
751 		if (!local->hw_scan_req)
752 			return -ENOMEM;
753 
754 		local->hw_scan_req->req.ssids = req->ssids;
755 		local->hw_scan_req->req.n_ssids = req->n_ssids;
756 		ies = (u8 *)local->hw_scan_req +
757 			sizeof(*local->hw_scan_req) +
758 			req->n_channels * sizeof(req->channels[0]);
759 		local->hw_scan_req->req.ie = ies;
760 		local->hw_scan_req->req.flags = req->flags;
761 		eth_broadcast_addr(local->hw_scan_req->req.bssid);
762 		local->hw_scan_req->req.duration = req->duration;
763 		local->hw_scan_req->req.duration_mandatory =
764 			req->duration_mandatory;
765 		local->hw_scan_req->req.tsf_report_link_id =
766 			req->tsf_report_link_id;
767 
768 		local->hw_scan_band = 0;
769 		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
770 		local->hw_scan_req->req.scan_6ghz_params =
771 			req->scan_6ghz_params;
772 		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
773 
774 		/*
775 		 * After allocating local->hw_scan_req, we must
776 		 * go through until ieee80211_prep_hw_scan(), so
777 		 * anything that might be changed here and leave
778 		 * this function early must not go after this
779 		 * allocation.
780 		 */
781 	}
782 
783 	rcu_assign_pointer(local->scan_req, req);
784 	rcu_assign_pointer(local->scan_sdata, sdata);
785 
786 	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
787 		get_random_mask_addr(local->scan_addr,
788 				     req->mac_addr,
789 				     req->mac_addr_mask);
790 	else
791 		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
792 
793 	if (hw_scan) {
794 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
795 	} else if ((req->n_channels == 1) &&
796 		   (req->channels[0] == local->hw.conf.chandef.chan)) {
797 		/*
798 		 * If we are scanning only on the operating channel
799 		 * then we do not need to stop normal activities
800 		 */
801 		unsigned long next_delay;
802 
803 		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
804 
805 		ieee80211_recalc_idle(local);
806 
807 		/* Notify driver scan is starting, keep order of operations
808 		 * same as normal software scan, in case that matters. */
809 		drv_sw_scan_start(local, sdata, local->scan_addr);
810 
811 		ieee80211_configure_filter(local); /* accept probe-responses */
812 
813 		/* We need to ensure power level is at max for scanning. */
814 		ieee80211_hw_conf_chan(local);
815 
816 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
817 						IEEE80211_CHAN_RADAR)) ||
818 		    !req->n_ssids) {
819 			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
820 			if (req->n_ssids)
821 				set_bit(SCAN_BEACON_WAIT, &local->scanning);
822 		} else {
823 			ieee80211_scan_state_send_probe(local, &next_delay);
824 			next_delay = IEEE80211_CHANNEL_TIME;
825 		}
826 
827 		/* Now, just wait a bit and we are all done! */
828 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
829 					 next_delay);
830 		return 0;
831 	} else {
832 		/* Do normal software scan */
833 		__set_bit(SCAN_SW_SCANNING, &local->scanning);
834 	}
835 
836 	ieee80211_recalc_idle(local);
837 
838 	if (hw_scan) {
839 		WARN_ON(!ieee80211_prep_hw_scan(sdata));
840 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
841 	} else {
842 		rc = ieee80211_start_sw_scan(local, sdata);
843 	}
844 
845 	if (rc) {
846 		kfree(local->hw_scan_req);
847 		local->hw_scan_req = NULL;
848 		local->scanning = 0;
849 
850 		ieee80211_recalc_idle(local);
851 
852 		local->scan_req = NULL;
853 		RCU_INIT_POINTER(local->scan_sdata, NULL);
854 	}
855 
856 	if (hw_scan && rc == 1) {
857 		/*
858 		 * we can't fall back to software for P2P-GO
859 		 * as it must update NoA etc.
860 		 */
861 		if (ieee80211_vif_type_p2p(&sdata->vif) ==
862 				NL80211_IFTYPE_P2P_GO)
863 			return -EOPNOTSUPP;
864 		hw_scan = false;
865 		goto again;
866 	}
867 
868 	return rc;
869 }
870 
871 static unsigned long
872 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
873 {
874 	/*
875 	 * TODO: channel switching also consumes quite some time,
876 	 * add that delay as well to get a better estimation
877 	 */
878 	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
879 		return IEEE80211_PASSIVE_CHANNEL_TIME;
880 	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
881 }
882 
883 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
884 					  unsigned long *next_delay)
885 {
886 	bool associated = false;
887 	bool tx_empty = true;
888 	bool bad_latency;
889 	struct ieee80211_sub_if_data *sdata;
890 	struct ieee80211_channel *next_chan;
891 	enum mac80211_scan_state next_scan_state;
892 	struct cfg80211_scan_request *scan_req;
893 
894 	lockdep_assert_wiphy(local->hw.wiphy);
895 
896 	/*
897 	 * check if at least one STA interface is associated,
898 	 * check if at least one STA interface has pending tx frames
899 	 * and grab the lowest used beacon interval
900 	 */
901 	list_for_each_entry(sdata, &local->interfaces, list) {
902 		if (!ieee80211_sdata_running(sdata))
903 			continue;
904 
905 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
906 			if (sdata->u.mgd.associated) {
907 				associated = true;
908 
909 				if (!qdisc_all_tx_empty(sdata->dev)) {
910 					tx_empty = false;
911 					break;
912 				}
913 			}
914 		}
915 	}
916 
917 	scan_req = rcu_dereference_protected(local->scan_req,
918 					     lockdep_is_held(&local->hw.wiphy->mtx));
919 
920 	next_chan = scan_req->channels[local->scan_channel_idx];
921 
922 	/*
923 	 * we're currently scanning a different channel, let's
924 	 * see if we can scan another channel without interfering
925 	 * with the current traffic situation.
926 	 *
927 	 * Keep good latency, do not stay off-channel more than 125 ms.
928 	 */
929 
930 	bad_latency = time_after(jiffies +
931 				 ieee80211_scan_get_channel_time(next_chan),
932 				 local->leave_oper_channel_time + HZ / 8);
933 
934 	if (associated && !tx_empty) {
935 		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
936 			next_scan_state = SCAN_ABORT;
937 		else
938 			next_scan_state = SCAN_SUSPEND;
939 	} else if (associated && bad_latency) {
940 		next_scan_state = SCAN_SUSPEND;
941 	} else {
942 		next_scan_state = SCAN_SET_CHANNEL;
943 	}
944 
945 	local->next_scan_state = next_scan_state;
946 
947 	*next_delay = 0;
948 }
949 
950 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
951 					     unsigned long *next_delay)
952 {
953 	int skip;
954 	struct ieee80211_channel *chan;
955 	struct cfg80211_scan_request *scan_req;
956 
957 	scan_req = rcu_dereference_protected(local->scan_req,
958 					     lockdep_is_held(&local->hw.wiphy->mtx));
959 
960 	skip = 0;
961 	chan = scan_req->channels[local->scan_channel_idx];
962 
963 	local->scan_chandef.chan = chan;
964 	local->scan_chandef.center_freq1 = chan->center_freq;
965 	local->scan_chandef.freq1_offset = chan->freq_offset;
966 	local->scan_chandef.center_freq2 = 0;
967 
968 	/* For scanning on the S1G band, detect the channel width according to
969 	 * the channel being scanned.
970 	 */
971 	if (chan->band == NL80211_BAND_S1GHZ) {
972 		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
973 		goto set_channel;
974 	}
975 
976 	/* If scanning on oper channel, use whatever channel-type
977 	 * is currently in use.
978 	 */
979 	if (chan == local->hw.conf.chandef.chan)
980 		local->scan_chandef = local->hw.conf.chandef;
981 	else
982 		local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
983 
984 set_channel:
985 	if (ieee80211_hw_conf_chan(local))
986 		skip = 1;
987 
988 	/* advance state machine to next channel/band */
989 	local->scan_channel_idx++;
990 
991 	if (skip) {
992 		/* if we skip this channel return to the decision state */
993 		local->next_scan_state = SCAN_DECISION;
994 		return;
995 	}
996 
997 	/*
998 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
999 	 * (which unfortunately doesn't say _why_ step a) is done,
1000 	 * but it waits for the probe delay or until a frame is
1001 	 * received - and the received frame would update the NAV).
1002 	 * For now, we do not support waiting until a frame is
1003 	 * received.
1004 	 *
1005 	 * In any case, it is not necessary for a passive scan.
1006 	 */
1007 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1008 	    !scan_req->n_ssids) {
1009 		*next_delay = msecs_to_jiffies(scan_req->duration) >
1010 			      IEEE80211_PASSIVE_CHANNEL_TIME ?
1011 			      msecs_to_jiffies(scan_req->duration) :
1012 			      IEEE80211_PASSIVE_CHANNEL_TIME;
1013 		local->next_scan_state = SCAN_DECISION;
1014 		if (scan_req->n_ssids)
1015 			set_bit(SCAN_BEACON_WAIT, &local->scanning);
1016 		return;
1017 	}
1018 
1019 	/* active scan, send probes */
1020 	*next_delay = IEEE80211_PROBE_DELAY;
1021 	local->next_scan_state = SCAN_SEND_PROBE;
1022 }
1023 
1024 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1025 					 unsigned long *next_delay)
1026 {
1027 	/* switch back to the operating channel */
1028 	local->scan_chandef.chan = NULL;
1029 	ieee80211_hw_conf_chan(local);
1030 
1031 	/* disable PS */
1032 	ieee80211_offchannel_return(local);
1033 
1034 	*next_delay = HZ / 5;
1035 	/* afterwards, resume scan & go to next channel */
1036 	local->next_scan_state = SCAN_RESUME;
1037 }
1038 
1039 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1040 					unsigned long *next_delay)
1041 {
1042 	ieee80211_offchannel_stop_vifs(local);
1043 
1044 	if (local->ops->flush) {
1045 		ieee80211_flush_queues(local, NULL, false);
1046 		*next_delay = 0;
1047 	} else
1048 		*next_delay = HZ / 10;
1049 
1050 	/* remember when we left the operating channel */
1051 	local->leave_oper_channel_time = jiffies;
1052 
1053 	/* advance to the next channel to be scanned */
1054 	local->next_scan_state = SCAN_SET_CHANNEL;
1055 }
1056 
1057 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1058 {
1059 	struct ieee80211_local *local =
1060 		container_of(work, struct ieee80211_local, scan_work.work);
1061 	struct ieee80211_sub_if_data *sdata;
1062 	struct cfg80211_scan_request *scan_req;
1063 	unsigned long next_delay = 0;
1064 	bool aborted;
1065 
1066 	lockdep_assert_wiphy(local->hw.wiphy);
1067 
1068 	if (!ieee80211_can_run_worker(local)) {
1069 		aborted = true;
1070 		goto out_complete;
1071 	}
1072 
1073 	sdata = rcu_dereference_protected(local->scan_sdata,
1074 					  lockdep_is_held(&local->hw.wiphy->mtx));
1075 	scan_req = rcu_dereference_protected(local->scan_req,
1076 					     lockdep_is_held(&local->hw.wiphy->mtx));
1077 
1078 	/* When scanning on-channel, the first-callback means completed. */
1079 	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1080 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1081 		goto out_complete;
1082 	}
1083 
1084 	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1085 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1086 		goto out_complete;
1087 	}
1088 
1089 	if (!sdata || !scan_req)
1090 		return;
1091 
1092 	if (!local->scanning) {
1093 		int rc;
1094 
1095 		RCU_INIT_POINTER(local->scan_req, NULL);
1096 		RCU_INIT_POINTER(local->scan_sdata, NULL);
1097 
1098 		rc = __ieee80211_start_scan(sdata, scan_req);
1099 		if (!rc)
1100 			return;
1101 		/* need to complete scan in cfg80211 */
1102 		rcu_assign_pointer(local->scan_req, scan_req);
1103 		aborted = true;
1104 		goto out_complete;
1105 	}
1106 
1107 	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1108 
1109 	/*
1110 	 * as long as no delay is required advance immediately
1111 	 * without scheduling a new work
1112 	 */
1113 	do {
1114 		if (!ieee80211_sdata_running(sdata)) {
1115 			aborted = true;
1116 			goto out_complete;
1117 		}
1118 
1119 		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1120 		    local->next_scan_state == SCAN_DECISION)
1121 			local->next_scan_state = SCAN_SEND_PROBE;
1122 
1123 		switch (local->next_scan_state) {
1124 		case SCAN_DECISION:
1125 			/* if no more bands/channels left, complete scan */
1126 			if (local->scan_channel_idx >= scan_req->n_channels) {
1127 				aborted = false;
1128 				goto out_complete;
1129 			}
1130 			ieee80211_scan_state_decision(local, &next_delay);
1131 			break;
1132 		case SCAN_SET_CHANNEL:
1133 			ieee80211_scan_state_set_channel(local, &next_delay);
1134 			break;
1135 		case SCAN_SEND_PROBE:
1136 			ieee80211_scan_state_send_probe(local, &next_delay);
1137 			break;
1138 		case SCAN_SUSPEND:
1139 			ieee80211_scan_state_suspend(local, &next_delay);
1140 			break;
1141 		case SCAN_RESUME:
1142 			ieee80211_scan_state_resume(local, &next_delay);
1143 			break;
1144 		case SCAN_ABORT:
1145 			aborted = true;
1146 			goto out_complete;
1147 		}
1148 	} while (next_delay == 0);
1149 
1150 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1151 				 next_delay);
1152 	return;
1153 
1154 out_complete:
1155 	__ieee80211_scan_completed(&local->hw, aborted);
1156 }
1157 
1158 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1159 			   struct cfg80211_scan_request *req)
1160 {
1161 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1162 
1163 	return __ieee80211_start_scan(sdata, req);
1164 }
1165 
1166 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1167 				const u8 *ssid, u8 ssid_len,
1168 				struct ieee80211_channel **channels,
1169 				unsigned int n_channels)
1170 {
1171 	struct ieee80211_local *local = sdata->local;
1172 	int ret = -EBUSY, i, n_ch = 0;
1173 	enum nl80211_band band;
1174 
1175 	lockdep_assert_wiphy(local->hw.wiphy);
1176 
1177 	/* busy scanning */
1178 	if (local->scan_req)
1179 		goto unlock;
1180 
1181 	/* fill internal scan request */
1182 	if (!channels) {
1183 		int max_n;
1184 
1185 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1186 			if (!local->hw.wiphy->bands[band] ||
1187 			    band == NL80211_BAND_6GHZ)
1188 				continue;
1189 
1190 			max_n = local->hw.wiphy->bands[band]->n_channels;
1191 			for (i = 0; i < max_n; i++) {
1192 				struct ieee80211_channel *tmp_ch =
1193 				    &local->hw.wiphy->bands[band]->channels[i];
1194 
1195 				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1196 						     IEEE80211_CHAN_DISABLED))
1197 					continue;
1198 
1199 				local->int_scan_req->channels[n_ch] = tmp_ch;
1200 				n_ch++;
1201 			}
1202 		}
1203 
1204 		if (WARN_ON_ONCE(n_ch == 0))
1205 			goto unlock;
1206 
1207 		local->int_scan_req->n_channels = n_ch;
1208 	} else {
1209 		for (i = 0; i < n_channels; i++) {
1210 			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1211 						  IEEE80211_CHAN_DISABLED))
1212 				continue;
1213 
1214 			local->int_scan_req->channels[n_ch] = channels[i];
1215 			n_ch++;
1216 		}
1217 
1218 		if (WARN_ON_ONCE(n_ch == 0))
1219 			goto unlock;
1220 
1221 		local->int_scan_req->n_channels = n_ch;
1222 	}
1223 
1224 	local->int_scan_req->ssids = &local->scan_ssid;
1225 	local->int_scan_req->n_ssids = 1;
1226 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1227 	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1228 
1229 	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1230  unlock:
1231 	return ret;
1232 }
1233 
1234 void ieee80211_scan_cancel(struct ieee80211_local *local)
1235 {
1236 	/* ensure a new scan cannot be queued */
1237 	lockdep_assert_wiphy(local->hw.wiphy);
1238 
1239 	/*
1240 	 * We are canceling software scan, or deferred scan that was not
1241 	 * yet really started (see __ieee80211_start_scan ).
1242 	 *
1243 	 * Regarding hardware scan:
1244 	 * - we can not call  __ieee80211_scan_completed() as when
1245 	 *   SCAN_HW_SCANNING bit is set this function change
1246 	 *   local->hw_scan_req to operate on 5G band, what race with
1247 	 *   driver which can use local->hw_scan_req
1248 	 *
1249 	 * - we can not cancel scan_work since driver can schedule it
1250 	 *   by ieee80211_scan_completed(..., true) to finish scan
1251 	 *
1252 	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1253 	 * driver is still responsible for calling ieee80211_scan_completed()
1254 	 * after the scan was completed/aborted.
1255 	 */
1256 
1257 	if (!local->scan_req)
1258 		return;
1259 
1260 	/*
1261 	 * We have a scan running and the driver already reported completion,
1262 	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1263 	 * cancelled.
1264 	 */
1265 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1266 	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1267 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1268 		return;
1269 	}
1270 
1271 	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1272 		/*
1273 		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1274 		 * scan on another band.
1275 		 */
1276 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1277 		if (local->ops->cancel_hw_scan)
1278 			drv_cancel_hw_scan(local,
1279 				rcu_dereference_protected(local->scan_sdata,
1280 						lockdep_is_held(&local->hw.wiphy->mtx)));
1281 		return;
1282 	}
1283 
1284 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1285 	/* and clean up */
1286 	memset(&local->scan_info, 0, sizeof(local->scan_info));
1287 	__ieee80211_scan_completed(&local->hw, true);
1288 }
1289 
1290 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1291 					struct cfg80211_sched_scan_request *req)
1292 {
1293 	struct ieee80211_local *local = sdata->local;
1294 	struct ieee80211_scan_ies sched_scan_ies = {};
1295 	struct cfg80211_chan_def chandef;
1296 	int ret, i, iebufsz, num_bands = 0;
1297 	u32 rate_masks[NUM_NL80211_BANDS] = {};
1298 	u8 bands_used = 0;
1299 	u8 *ie;
1300 	u32 flags = 0;
1301 
1302 	lockdep_assert_wiphy(local->hw.wiphy);
1303 
1304 	iebufsz = local->scan_ies_len + req->ie_len;
1305 
1306 	if (!local->ops->sched_scan_start)
1307 		return -EOPNOTSUPP;
1308 
1309 	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1310 		if (local->hw.wiphy->bands[i]) {
1311 			bands_used |= BIT(i);
1312 			rate_masks[i] = (u32) -1;
1313 			num_bands++;
1314 		}
1315 	}
1316 
1317 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1318 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1319 
1320 	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1321 	if (!ie) {
1322 		ret = -ENOMEM;
1323 		goto out;
1324 	}
1325 
1326 	ieee80211_prepare_scan_chandef(&chandef);
1327 
1328 	ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1329 				       &sched_scan_ies, req->ie,
1330 				       req->ie_len, bands_used, rate_masks,
1331 				       &chandef, flags);
1332 	if (ret < 0)
1333 		goto error;
1334 
1335 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1336 	if (ret == 0) {
1337 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1338 		rcu_assign_pointer(local->sched_scan_req, req);
1339 	}
1340 
1341 error:
1342 	kfree(ie);
1343 out:
1344 	if (ret) {
1345 		/* Clean in case of failure after HW restart or upon resume. */
1346 		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1347 		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1348 	}
1349 
1350 	return ret;
1351 }
1352 
1353 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1354 				       struct cfg80211_sched_scan_request *req)
1355 {
1356 	struct ieee80211_local *local = sdata->local;
1357 
1358 	lockdep_assert_wiphy(local->hw.wiphy);
1359 
1360 	if (rcu_access_pointer(local->sched_scan_sdata))
1361 		return -EBUSY;
1362 
1363 	return __ieee80211_request_sched_scan_start(sdata, req);
1364 }
1365 
1366 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1367 {
1368 	struct ieee80211_sub_if_data *sched_scan_sdata;
1369 	int ret = -ENOENT;
1370 
1371 	lockdep_assert_wiphy(local->hw.wiphy);
1372 
1373 	if (!local->ops->sched_scan_stop)
1374 		return -EOPNOTSUPP;
1375 
1376 	/* We don't want to restart sched scan anymore. */
1377 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1378 
1379 	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1380 						lockdep_is_held(&local->hw.wiphy->mtx));
1381 	if (sched_scan_sdata) {
1382 		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1383 		if (!ret)
1384 			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1385 	}
1386 
1387 	return ret;
1388 }
1389 
1390 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1391 {
1392 	struct ieee80211_local *local = hw_to_local(hw);
1393 
1394 	trace_api_sched_scan_results(local);
1395 
1396 	cfg80211_sched_scan_results(hw->wiphy, 0);
1397 }
1398 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1399 
1400 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1401 {
1402 	lockdep_assert_wiphy(local->hw.wiphy);
1403 
1404 	if (!rcu_access_pointer(local->sched_scan_sdata))
1405 		return;
1406 
1407 	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1408 
1409 	/* If sched scan was aborted by the driver. */
1410 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1411 
1412 	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1413 }
1414 
1415 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1416 				       struct wiphy_work *work)
1417 {
1418 	struct ieee80211_local *local =
1419 		container_of(work, struct ieee80211_local,
1420 			     sched_scan_stopped_work);
1421 
1422 	ieee80211_sched_scan_end(local);
1423 }
1424 
1425 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1426 {
1427 	struct ieee80211_local *local = hw_to_local(hw);
1428 
1429 	trace_api_sched_scan_stopped(local);
1430 
1431 	/*
1432 	 * this shouldn't really happen, so for simplicity
1433 	 * simply ignore it, and let mac80211 reconfigure
1434 	 * the sched scan later on.
1435 	 */
1436 	if (local->in_reconfig)
1437 		return;
1438 
1439 	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1440 }
1441 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1442