xref: /linux/net/mac80211/scan.c (revision 59fff63cc2b75dcfe08f9eeb4b2187d73e53843d)
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) 2018-2023 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 		bss_meta.parent_tsf =
198 			ieee80211_calculate_rx_timestamp(local, rx_status,
199 							 len + FCS_LEN, 24);
200 		ether_addr_copy(bss_meta.parent_bssid,
201 				scan_sdata->vif.bss_conf.bssid);
202 	}
203 	rcu_read_unlock();
204 
205 	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
206 					      mgmt, len, GFP_ATOMIC);
207 	if (!cbss)
208 		return NULL;
209 
210 	/* In case the signal is invalid update the status */
211 	signal_valid = channel == cbss->channel;
212 	if (!signal_valid)
213 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
214 
215 	return (void *)cbss->priv;
216 }
217 
218 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
219 					u32 scan_flags, const u8 *da)
220 {
221 	if (!sdata)
222 		return false;
223 	/* accept broadcast for OCE */
224 	if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
225 	    is_broadcast_ether_addr(da))
226 		return true;
227 	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
228 		return true;
229 	return ether_addr_equal(da, sdata->vif.addr);
230 }
231 
232 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
233 {
234 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
235 	struct ieee80211_sub_if_data *sdata1, *sdata2;
236 	struct ieee80211_mgmt *mgmt = (void *)skb->data;
237 	struct ieee80211_bss *bss;
238 	struct ieee80211_channel *channel;
239 	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
240 				      u.probe_resp.variable);
241 
242 	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
243 	    !ieee80211_is_beacon(mgmt->frame_control) &&
244 	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
245 		return;
246 
247 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
248 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
249 			min_hdr_len = offsetof(struct ieee80211_ext,
250 					       u.s1g_short_beacon.variable);
251 		else
252 			min_hdr_len = offsetof(struct ieee80211_ext,
253 					       u.s1g_beacon);
254 	}
255 
256 	if (skb->len < min_hdr_len)
257 		return;
258 
259 	sdata1 = rcu_dereference(local->scan_sdata);
260 	sdata2 = rcu_dereference(local->sched_scan_sdata);
261 
262 	if (likely(!sdata1 && !sdata2))
263 		return;
264 
265 	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
266 		/*
267 		 * we were passive scanning because of radar/no-IR, but
268 		 * the beacon/proberesp rx gives us an opportunity to upgrade
269 		 * to active scan
270 		 */
271 		set_bit(SCAN_BEACON_DONE, &local->scanning);
272 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
273 	}
274 
275 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
276 		struct cfg80211_scan_request *scan_req;
277 		struct cfg80211_sched_scan_request *sched_scan_req;
278 		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
279 
280 		scan_req = rcu_dereference(local->scan_req);
281 		sched_scan_req = rcu_dereference(local->sched_scan_req);
282 
283 		if (scan_req)
284 			scan_req_flags = scan_req->flags;
285 
286 		if (sched_scan_req)
287 			sched_scan_req_flags = sched_scan_req->flags;
288 
289 		/* ignore ProbeResp to foreign address or non-bcast (OCE)
290 		 * unless scanning with randomised address
291 		 */
292 		if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
293 						 mgmt->da) &&
294 		    !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
295 						 mgmt->da))
296 			return;
297 	}
298 
299 	channel = ieee80211_get_channel_khz(local->hw.wiphy,
300 					ieee80211_rx_status_to_khz(rx_status));
301 
302 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
303 		return;
304 
305 	bss = ieee80211_bss_info_update(local, rx_status,
306 					mgmt, skb->len,
307 					channel);
308 	if (bss)
309 		ieee80211_rx_bss_put(local, bss);
310 }
311 
312 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
313 {
314 	memset(chandef, 0, sizeof(*chandef));
315 
316 	chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
317 }
318 
319 /* return false if no more work */
320 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
321 {
322 	struct ieee80211_local *local = sdata->local;
323 	struct cfg80211_scan_request *req;
324 	struct cfg80211_chan_def chandef;
325 	u8 bands_used = 0;
326 	int i, ielen, n_chans;
327 	u32 flags = 0;
328 
329 	req = rcu_dereference_protected(local->scan_req,
330 					lockdep_is_held(&local->hw.wiphy->mtx));
331 
332 	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
333 		return false;
334 
335 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
336 		for (i = 0; i < req->n_channels; i++) {
337 			local->hw_scan_req->req.channels[i] = req->channels[i];
338 			bands_used |= BIT(req->channels[i]->band);
339 		}
340 
341 		n_chans = req->n_channels;
342 	} else {
343 		do {
344 			if (local->hw_scan_band == NUM_NL80211_BANDS)
345 				return false;
346 
347 			n_chans = 0;
348 
349 			for (i = 0; i < req->n_channels; i++) {
350 				if (req->channels[i]->band !=
351 				    local->hw_scan_band)
352 					continue;
353 				local->hw_scan_req->req.channels[n_chans] =
354 							req->channels[i];
355 				n_chans++;
356 				bands_used |= BIT(req->channels[i]->band);
357 			}
358 
359 			local->hw_scan_band++;
360 		} while (!n_chans);
361 	}
362 
363 	local->hw_scan_req->req.n_channels = n_chans;
364 	ieee80211_prepare_scan_chandef(&chandef);
365 
366 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
367 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
368 
369 	ielen = ieee80211_build_preq_ies(sdata,
370 					 (u8 *)local->hw_scan_req->req.ie,
371 					 local->hw_scan_ies_bufsize,
372 					 &local->hw_scan_req->ies,
373 					 req->ie, req->ie_len,
374 					 bands_used, req->rates, &chandef,
375 					 flags);
376 	local->hw_scan_req->req.ie_len = ielen;
377 	local->hw_scan_req->req.no_cck = req->no_cck;
378 	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
379 	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
380 			req->mac_addr_mask);
381 	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
382 
383 	return true;
384 }
385 
386 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
387 {
388 	struct ieee80211_local *local = hw_to_local(hw);
389 	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
390 	bool was_scanning = local->scanning;
391 	struct cfg80211_scan_request *scan_req;
392 	struct ieee80211_sub_if_data *scan_sdata;
393 	struct ieee80211_sub_if_data *sdata;
394 
395 	lockdep_assert_wiphy(local->hw.wiphy);
396 
397 	/*
398 	 * It's ok to abort a not-yet-running scan (that
399 	 * we have one at all will be verified by checking
400 	 * local->scan_req next), but not to complete it
401 	 * successfully.
402 	 */
403 	if (WARN_ON(!local->scanning && !aborted))
404 		aborted = true;
405 
406 	if (WARN_ON(!local->scan_req))
407 		return;
408 
409 	scan_sdata = rcu_dereference_protected(local->scan_sdata,
410 					       lockdep_is_held(&local->hw.wiphy->mtx));
411 
412 	if (hw_scan && !aborted &&
413 	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
414 	    ieee80211_prep_hw_scan(scan_sdata)) {
415 		int rc;
416 
417 		rc = drv_hw_scan(local,
418 			rcu_dereference_protected(local->scan_sdata,
419 						  lockdep_is_held(&local->hw.wiphy->mtx)),
420 			local->hw_scan_req);
421 
422 		if (rc == 0)
423 			return;
424 
425 		/* HW scan failed and is going to be reported as aborted,
426 		 * so clear old scan info.
427 		 */
428 		memset(&local->scan_info, 0, sizeof(local->scan_info));
429 		aborted = true;
430 	}
431 
432 	kfree(local->hw_scan_req);
433 	local->hw_scan_req = NULL;
434 
435 	scan_req = rcu_dereference_protected(local->scan_req,
436 					     lockdep_is_held(&local->hw.wiphy->mtx));
437 
438 	RCU_INIT_POINTER(local->scan_req, NULL);
439 	RCU_INIT_POINTER(local->scan_sdata, NULL);
440 
441 	local->scanning = 0;
442 	local->scan_chandef.chan = NULL;
443 
444 	synchronize_rcu();
445 
446 	if (scan_req != local->int_scan_req) {
447 		local->scan_info.aborted = aborted;
448 		cfg80211_scan_done(scan_req, &local->scan_info);
449 	}
450 
451 	/* Set power back to normal operating levels. */
452 	ieee80211_hw_config(local, 0);
453 
454 	if (!hw_scan && was_scanning) {
455 		ieee80211_configure_filter(local);
456 		drv_sw_scan_complete(local, scan_sdata);
457 		ieee80211_offchannel_return(local);
458 	}
459 
460 	ieee80211_recalc_idle(local);
461 
462 	ieee80211_mlme_notify_scan_completed(local);
463 	ieee80211_ibss_notify_scan_completed(local);
464 
465 	/* Requeue all the work that might have been ignored while
466 	 * the scan was in progress; if there was none this will
467 	 * just be a no-op for the particular interface.
468 	 */
469 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
470 		if (ieee80211_sdata_running(sdata))
471 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
472 	}
473 
474 	if (was_scanning)
475 		ieee80211_start_next_roc(local);
476 }
477 
478 void ieee80211_scan_completed(struct ieee80211_hw *hw,
479 			      struct cfg80211_scan_info *info)
480 {
481 	struct ieee80211_local *local = hw_to_local(hw);
482 
483 	trace_api_scan_completed(local, info->aborted);
484 
485 	set_bit(SCAN_COMPLETED, &local->scanning);
486 	if (info->aborted)
487 		set_bit(SCAN_ABORTED, &local->scanning);
488 
489 	memcpy(&local->scan_info, info, sizeof(*info));
490 
491 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
492 }
493 EXPORT_SYMBOL(ieee80211_scan_completed);
494 
495 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
496 				   struct ieee80211_sub_if_data *sdata)
497 {
498 	/* Software scan is not supported in multi-channel cases */
499 	if (local->use_chanctx)
500 		return -EOPNOTSUPP;
501 
502 	/*
503 	 * Hardware/driver doesn't support hw_scan, so use software
504 	 * scanning instead. First send a nullfunc frame with power save
505 	 * bit on so that AP will buffer the frames for us while we are not
506 	 * listening, then send probe requests to each channel and wait for
507 	 * the responses. After all channels are scanned, tune back to the
508 	 * original channel and send a nullfunc frame with power save bit
509 	 * off to trigger the AP to send us all the buffered frames.
510 	 *
511 	 * Note that while local->sw_scanning is true everything else but
512 	 * nullfunc frames and probe requests will be dropped in
513 	 * ieee80211_tx_h_check_assoc().
514 	 */
515 	drv_sw_scan_start(local, sdata, local->scan_addr);
516 
517 	local->leave_oper_channel_time = jiffies;
518 	local->next_scan_state = SCAN_DECISION;
519 	local->scan_channel_idx = 0;
520 
521 	ieee80211_offchannel_stop_vifs(local);
522 
523 	/* ensure nullfunc is transmitted before leaving operating channel */
524 	ieee80211_flush_queues(local, NULL, false);
525 
526 	ieee80211_configure_filter(local);
527 
528 	/* We need to set power level at maximum rate for scanning. */
529 	ieee80211_hw_config(local, 0);
530 
531 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
532 
533 	return 0;
534 }
535 
536 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
537 {
538 	struct ieee80211_local *local = sdata->local;
539 	struct ieee80211_sub_if_data *sdata_iter;
540 
541 	lockdep_assert_wiphy(local->hw.wiphy);
542 
543 	if (!ieee80211_is_radar_required(local))
544 		return true;
545 
546 	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
547 		return false;
548 
549 	list_for_each_entry(sdata_iter, &local->interfaces, list) {
550 		if (sdata_iter->wdev.cac_started)
551 			return false;
552 	}
553 
554 	return true;
555 }
556 
557 static bool ieee80211_can_scan(struct ieee80211_local *local,
558 			       struct ieee80211_sub_if_data *sdata)
559 {
560 	if (!__ieee80211_can_leave_ch(sdata))
561 		return false;
562 
563 	if (!list_empty(&local->roc_list))
564 		return false;
565 
566 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
567 	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
568 		return false;
569 
570 	return true;
571 }
572 
573 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
574 {
575 	lockdep_assert_wiphy(local->hw.wiphy);
576 
577 	if (!local->scan_req || local->scanning)
578 		return;
579 
580 	if (!ieee80211_can_scan(local,
581 				rcu_dereference_protected(
582 					local->scan_sdata,
583 					lockdep_is_held(&local->hw.wiphy->mtx))))
584 		return;
585 
586 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
587 				 round_jiffies_relative(0));
588 }
589 
590 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
591 					  const u8 *src, const u8 *dst,
592 					  const u8 *ssid, size_t ssid_len,
593 					  const u8 *ie, size_t ie_len,
594 					  u32 ratemask, u32 flags, u32 tx_flags,
595 					  struct ieee80211_channel *channel)
596 {
597 	struct sk_buff *skb;
598 
599 	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
600 					ssid, ssid_len,
601 					ie, ie_len, flags);
602 
603 	if (skb) {
604 		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
605 			struct ieee80211_hdr *hdr = (void *)skb->data;
606 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
607 			u16 sn = get_random_u16();
608 
609 			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
610 			hdr->seq_ctrl =
611 				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
612 		}
613 		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
614 		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
615 	}
616 }
617 
618 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
619 					    unsigned long *next_delay)
620 {
621 	int i;
622 	struct ieee80211_sub_if_data *sdata;
623 	struct cfg80211_scan_request *scan_req;
624 	enum nl80211_band band = local->hw.conf.chandef.chan->band;
625 	u32 flags = 0, tx_flags;
626 
627 	scan_req = rcu_dereference_protected(local->scan_req,
628 					     lockdep_is_held(&local->hw.wiphy->mtx));
629 
630 	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
631 	if (scan_req->no_cck)
632 		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
633 	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
634 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
635 	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
636 		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
637 
638 	sdata = rcu_dereference_protected(local->scan_sdata,
639 					  lockdep_is_held(&local->hw.wiphy->mtx));
640 
641 	for (i = 0; i < scan_req->n_ssids; i++)
642 		ieee80211_send_scan_probe_req(
643 			sdata, local->scan_addr, scan_req->bssid,
644 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
645 			scan_req->ie, scan_req->ie_len,
646 			scan_req->rates[band], flags,
647 			tx_flags, local->hw.conf.chandef.chan);
648 
649 	/*
650 	 * After sending probe requests, wait for probe responses
651 	 * on the channel.
652 	 */
653 	*next_delay = IEEE80211_CHANNEL_TIME;
654 	local->next_scan_state = SCAN_DECISION;
655 }
656 
657 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
658 				  struct cfg80211_scan_request *req)
659 {
660 	struct ieee80211_local *local = sdata->local;
661 	bool hw_scan = local->ops->hw_scan;
662 	int rc;
663 
664 	lockdep_assert_wiphy(local->hw.wiphy);
665 
666 	if (local->scan_req)
667 		return -EBUSY;
668 
669 	if (!__ieee80211_can_leave_ch(sdata))
670 		return -EBUSY;
671 
672 	if (!ieee80211_can_scan(local, sdata)) {
673 		/* wait for the work to finish/time out */
674 		rcu_assign_pointer(local->scan_req, req);
675 		rcu_assign_pointer(local->scan_sdata, sdata);
676 		return 0;
677 	}
678 
679  again:
680 	if (hw_scan) {
681 		u8 *ies;
682 
683 		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
684 
685 		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
686 			int i, n_bands = 0;
687 			u8 bands_counted = 0;
688 
689 			for (i = 0; i < req->n_channels; i++) {
690 				if (bands_counted & BIT(req->channels[i]->band))
691 					continue;
692 				bands_counted |= BIT(req->channels[i]->band);
693 				n_bands++;
694 			}
695 
696 			local->hw_scan_ies_bufsize *= n_bands;
697 		}
698 
699 		local->hw_scan_req = kmalloc(
700 				sizeof(*local->hw_scan_req) +
701 				req->n_channels * sizeof(req->channels[0]) +
702 				local->hw_scan_ies_bufsize, GFP_KERNEL);
703 		if (!local->hw_scan_req)
704 			return -ENOMEM;
705 
706 		local->hw_scan_req->req.ssids = req->ssids;
707 		local->hw_scan_req->req.n_ssids = req->n_ssids;
708 		ies = (u8 *)local->hw_scan_req +
709 			sizeof(*local->hw_scan_req) +
710 			req->n_channels * sizeof(req->channels[0]);
711 		local->hw_scan_req->req.ie = ies;
712 		local->hw_scan_req->req.flags = req->flags;
713 		eth_broadcast_addr(local->hw_scan_req->req.bssid);
714 		local->hw_scan_req->req.duration = req->duration;
715 		local->hw_scan_req->req.duration_mandatory =
716 			req->duration_mandatory;
717 
718 		local->hw_scan_band = 0;
719 		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
720 		local->hw_scan_req->req.scan_6ghz_params =
721 			req->scan_6ghz_params;
722 		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
723 
724 		/*
725 		 * After allocating local->hw_scan_req, we must
726 		 * go through until ieee80211_prep_hw_scan(), so
727 		 * anything that might be changed here and leave
728 		 * this function early must not go after this
729 		 * allocation.
730 		 */
731 	}
732 
733 	rcu_assign_pointer(local->scan_req, req);
734 	rcu_assign_pointer(local->scan_sdata, sdata);
735 
736 	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
737 		get_random_mask_addr(local->scan_addr,
738 				     req->mac_addr,
739 				     req->mac_addr_mask);
740 	else
741 		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
742 
743 	if (hw_scan) {
744 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
745 	} else if ((req->n_channels == 1) &&
746 		   (req->channels[0] == local->_oper_chandef.chan)) {
747 		/*
748 		 * If we are scanning only on the operating channel
749 		 * then we do not need to stop normal activities
750 		 */
751 		unsigned long next_delay;
752 
753 		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
754 
755 		ieee80211_recalc_idle(local);
756 
757 		/* Notify driver scan is starting, keep order of operations
758 		 * same as normal software scan, in case that matters. */
759 		drv_sw_scan_start(local, sdata, local->scan_addr);
760 
761 		ieee80211_configure_filter(local); /* accept probe-responses */
762 
763 		/* We need to ensure power level is at max for scanning. */
764 		ieee80211_hw_config(local, 0);
765 
766 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
767 						IEEE80211_CHAN_RADAR)) ||
768 		    !req->n_ssids) {
769 			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
770 			if (req->n_ssids)
771 				set_bit(SCAN_BEACON_WAIT, &local->scanning);
772 		} else {
773 			ieee80211_scan_state_send_probe(local, &next_delay);
774 			next_delay = IEEE80211_CHANNEL_TIME;
775 		}
776 
777 		/* Now, just wait a bit and we are all done! */
778 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
779 					 next_delay);
780 		return 0;
781 	} else {
782 		/* Do normal software scan */
783 		__set_bit(SCAN_SW_SCANNING, &local->scanning);
784 	}
785 
786 	ieee80211_recalc_idle(local);
787 
788 	if (hw_scan) {
789 		WARN_ON(!ieee80211_prep_hw_scan(sdata));
790 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
791 	} else {
792 		rc = ieee80211_start_sw_scan(local, sdata);
793 	}
794 
795 	if (rc) {
796 		kfree(local->hw_scan_req);
797 		local->hw_scan_req = NULL;
798 		local->scanning = 0;
799 
800 		ieee80211_recalc_idle(local);
801 
802 		local->scan_req = NULL;
803 		RCU_INIT_POINTER(local->scan_sdata, NULL);
804 	}
805 
806 	if (hw_scan && rc == 1) {
807 		/*
808 		 * we can't fall back to software for P2P-GO
809 		 * as it must update NoA etc.
810 		 */
811 		if (ieee80211_vif_type_p2p(&sdata->vif) ==
812 				NL80211_IFTYPE_P2P_GO)
813 			return -EOPNOTSUPP;
814 		hw_scan = false;
815 		goto again;
816 	}
817 
818 	return rc;
819 }
820 
821 static unsigned long
822 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
823 {
824 	/*
825 	 * TODO: channel switching also consumes quite some time,
826 	 * add that delay as well to get a better estimation
827 	 */
828 	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
829 		return IEEE80211_PASSIVE_CHANNEL_TIME;
830 	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
831 }
832 
833 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
834 					  unsigned long *next_delay)
835 {
836 	bool associated = false;
837 	bool tx_empty = true;
838 	bool bad_latency;
839 	struct ieee80211_sub_if_data *sdata;
840 	struct ieee80211_channel *next_chan;
841 	enum mac80211_scan_state next_scan_state;
842 	struct cfg80211_scan_request *scan_req;
843 
844 	lockdep_assert_wiphy(local->hw.wiphy);
845 
846 	/*
847 	 * check if at least one STA interface is associated,
848 	 * check if at least one STA interface has pending tx frames
849 	 * and grab the lowest used beacon interval
850 	 */
851 	list_for_each_entry(sdata, &local->interfaces, list) {
852 		if (!ieee80211_sdata_running(sdata))
853 			continue;
854 
855 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
856 			if (sdata->u.mgd.associated) {
857 				associated = true;
858 
859 				if (!qdisc_all_tx_empty(sdata->dev)) {
860 					tx_empty = false;
861 					break;
862 				}
863 			}
864 		}
865 	}
866 
867 	scan_req = rcu_dereference_protected(local->scan_req,
868 					     lockdep_is_held(&local->hw.wiphy->mtx));
869 
870 	next_chan = scan_req->channels[local->scan_channel_idx];
871 
872 	/*
873 	 * we're currently scanning a different channel, let's
874 	 * see if we can scan another channel without interfering
875 	 * with the current traffic situation.
876 	 *
877 	 * Keep good latency, do not stay off-channel more than 125 ms.
878 	 */
879 
880 	bad_latency = time_after(jiffies +
881 				 ieee80211_scan_get_channel_time(next_chan),
882 				 local->leave_oper_channel_time + HZ / 8);
883 
884 	if (associated && !tx_empty) {
885 		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
886 			next_scan_state = SCAN_ABORT;
887 		else
888 			next_scan_state = SCAN_SUSPEND;
889 	} else if (associated && bad_latency) {
890 		next_scan_state = SCAN_SUSPEND;
891 	} else {
892 		next_scan_state = SCAN_SET_CHANNEL;
893 	}
894 
895 	local->next_scan_state = next_scan_state;
896 
897 	*next_delay = 0;
898 }
899 
900 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
901 					     unsigned long *next_delay)
902 {
903 	int skip;
904 	struct ieee80211_channel *chan;
905 	struct cfg80211_scan_request *scan_req;
906 
907 	scan_req = rcu_dereference_protected(local->scan_req,
908 					     lockdep_is_held(&local->hw.wiphy->mtx));
909 
910 	skip = 0;
911 	chan = scan_req->channels[local->scan_channel_idx];
912 
913 	local->scan_chandef.chan = chan;
914 	local->scan_chandef.center_freq1 = chan->center_freq;
915 	local->scan_chandef.freq1_offset = chan->freq_offset;
916 	local->scan_chandef.center_freq2 = 0;
917 
918 	/* For scanning on the S1G band, detect the channel width according to
919 	 * the channel being scanned.
920 	 */
921 	if (chan->band == NL80211_BAND_S1GHZ) {
922 		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
923 		goto set_channel;
924 	}
925 
926 	/* If scanning on oper channel, use whatever channel-type
927 	 * is currently in use.
928 	 */
929 	if (chan == local->_oper_chandef.chan)
930 		local->scan_chandef = local->_oper_chandef;
931 	else
932 		local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
933 
934 set_channel:
935 	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
936 		skip = 1;
937 
938 	/* advance state machine to next channel/band */
939 	local->scan_channel_idx++;
940 
941 	if (skip) {
942 		/* if we skip this channel return to the decision state */
943 		local->next_scan_state = SCAN_DECISION;
944 		return;
945 	}
946 
947 	/*
948 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
949 	 * (which unfortunately doesn't say _why_ step a) is done,
950 	 * but it waits for the probe delay or until a frame is
951 	 * received - and the received frame would update the NAV).
952 	 * For now, we do not support waiting until a frame is
953 	 * received.
954 	 *
955 	 * In any case, it is not necessary for a passive scan.
956 	 */
957 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
958 	    !scan_req->n_ssids) {
959 		*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
960 		local->next_scan_state = SCAN_DECISION;
961 		if (scan_req->n_ssids)
962 			set_bit(SCAN_BEACON_WAIT, &local->scanning);
963 		return;
964 	}
965 
966 	/* active scan, send probes */
967 	*next_delay = IEEE80211_PROBE_DELAY;
968 	local->next_scan_state = SCAN_SEND_PROBE;
969 }
970 
971 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
972 					 unsigned long *next_delay)
973 {
974 	/* switch back to the operating channel */
975 	local->scan_chandef.chan = NULL;
976 	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
977 
978 	/* disable PS */
979 	ieee80211_offchannel_return(local);
980 
981 	*next_delay = HZ / 5;
982 	/* afterwards, resume scan & go to next channel */
983 	local->next_scan_state = SCAN_RESUME;
984 }
985 
986 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
987 					unsigned long *next_delay)
988 {
989 	ieee80211_offchannel_stop_vifs(local);
990 
991 	if (local->ops->flush) {
992 		ieee80211_flush_queues(local, NULL, false);
993 		*next_delay = 0;
994 	} else
995 		*next_delay = HZ / 10;
996 
997 	/* remember when we left the operating channel */
998 	local->leave_oper_channel_time = jiffies;
999 
1000 	/* advance to the next channel to be scanned */
1001 	local->next_scan_state = SCAN_SET_CHANNEL;
1002 }
1003 
1004 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1005 {
1006 	struct ieee80211_local *local =
1007 		container_of(work, struct ieee80211_local, scan_work.work);
1008 	struct ieee80211_sub_if_data *sdata;
1009 	struct cfg80211_scan_request *scan_req;
1010 	unsigned long next_delay = 0;
1011 	bool aborted;
1012 
1013 	lockdep_assert_wiphy(local->hw.wiphy);
1014 
1015 	if (!ieee80211_can_run_worker(local)) {
1016 		aborted = true;
1017 		goto out_complete;
1018 	}
1019 
1020 	sdata = rcu_dereference_protected(local->scan_sdata,
1021 					  lockdep_is_held(&local->hw.wiphy->mtx));
1022 	scan_req = rcu_dereference_protected(local->scan_req,
1023 					     lockdep_is_held(&local->hw.wiphy->mtx));
1024 
1025 	/* When scanning on-channel, the first-callback means completed. */
1026 	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1027 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1028 		goto out_complete;
1029 	}
1030 
1031 	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1032 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1033 		goto out_complete;
1034 	}
1035 
1036 	if (!sdata || !scan_req)
1037 		return;
1038 
1039 	if (!local->scanning) {
1040 		int rc;
1041 
1042 		RCU_INIT_POINTER(local->scan_req, NULL);
1043 		RCU_INIT_POINTER(local->scan_sdata, NULL);
1044 
1045 		rc = __ieee80211_start_scan(sdata, scan_req);
1046 		if (!rc)
1047 			return;
1048 		/* need to complete scan in cfg80211 */
1049 		rcu_assign_pointer(local->scan_req, scan_req);
1050 		aborted = true;
1051 		goto out_complete;
1052 	}
1053 
1054 	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1055 
1056 	/*
1057 	 * as long as no delay is required advance immediately
1058 	 * without scheduling a new work
1059 	 */
1060 	do {
1061 		if (!ieee80211_sdata_running(sdata)) {
1062 			aborted = true;
1063 			goto out_complete;
1064 		}
1065 
1066 		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1067 		    local->next_scan_state == SCAN_DECISION)
1068 			local->next_scan_state = SCAN_SEND_PROBE;
1069 
1070 		switch (local->next_scan_state) {
1071 		case SCAN_DECISION:
1072 			/* if no more bands/channels left, complete scan */
1073 			if (local->scan_channel_idx >= scan_req->n_channels) {
1074 				aborted = false;
1075 				goto out_complete;
1076 			}
1077 			ieee80211_scan_state_decision(local, &next_delay);
1078 			break;
1079 		case SCAN_SET_CHANNEL:
1080 			ieee80211_scan_state_set_channel(local, &next_delay);
1081 			break;
1082 		case SCAN_SEND_PROBE:
1083 			ieee80211_scan_state_send_probe(local, &next_delay);
1084 			break;
1085 		case SCAN_SUSPEND:
1086 			ieee80211_scan_state_suspend(local, &next_delay);
1087 			break;
1088 		case SCAN_RESUME:
1089 			ieee80211_scan_state_resume(local, &next_delay);
1090 			break;
1091 		case SCAN_ABORT:
1092 			aborted = true;
1093 			goto out_complete;
1094 		}
1095 	} while (next_delay == 0);
1096 
1097 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1098 				 next_delay);
1099 	return;
1100 
1101 out_complete:
1102 	__ieee80211_scan_completed(&local->hw, aborted);
1103 }
1104 
1105 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1106 			   struct cfg80211_scan_request *req)
1107 {
1108 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1109 
1110 	return __ieee80211_start_scan(sdata, req);
1111 }
1112 
1113 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1114 				const u8 *ssid, u8 ssid_len,
1115 				struct ieee80211_channel **channels,
1116 				unsigned int n_channels)
1117 {
1118 	struct ieee80211_local *local = sdata->local;
1119 	int ret = -EBUSY, i, n_ch = 0;
1120 	enum nl80211_band band;
1121 
1122 	lockdep_assert_wiphy(local->hw.wiphy);
1123 
1124 	/* busy scanning */
1125 	if (local->scan_req)
1126 		goto unlock;
1127 
1128 	/* fill internal scan request */
1129 	if (!channels) {
1130 		int max_n;
1131 
1132 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1133 			if (!local->hw.wiphy->bands[band] ||
1134 			    band == NL80211_BAND_6GHZ)
1135 				continue;
1136 
1137 			max_n = local->hw.wiphy->bands[band]->n_channels;
1138 			for (i = 0; i < max_n; i++) {
1139 				struct ieee80211_channel *tmp_ch =
1140 				    &local->hw.wiphy->bands[band]->channels[i];
1141 
1142 				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1143 						     IEEE80211_CHAN_DISABLED))
1144 					continue;
1145 
1146 				local->int_scan_req->channels[n_ch] = tmp_ch;
1147 				n_ch++;
1148 			}
1149 		}
1150 
1151 		if (WARN_ON_ONCE(n_ch == 0))
1152 			goto unlock;
1153 
1154 		local->int_scan_req->n_channels = n_ch;
1155 	} else {
1156 		for (i = 0; i < n_channels; i++) {
1157 			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1158 						  IEEE80211_CHAN_DISABLED))
1159 				continue;
1160 
1161 			local->int_scan_req->channels[n_ch] = channels[i];
1162 			n_ch++;
1163 		}
1164 
1165 		if (WARN_ON_ONCE(n_ch == 0))
1166 			goto unlock;
1167 
1168 		local->int_scan_req->n_channels = n_ch;
1169 	}
1170 
1171 	local->int_scan_req->ssids = &local->scan_ssid;
1172 	local->int_scan_req->n_ssids = 1;
1173 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1174 	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1175 
1176 	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1177  unlock:
1178 	return ret;
1179 }
1180 
1181 void ieee80211_scan_cancel(struct ieee80211_local *local)
1182 {
1183 	/* ensure a new scan cannot be queued */
1184 	lockdep_assert_wiphy(local->hw.wiphy);
1185 
1186 	/*
1187 	 * We are canceling software scan, or deferred scan that was not
1188 	 * yet really started (see __ieee80211_start_scan ).
1189 	 *
1190 	 * Regarding hardware scan:
1191 	 * - we can not call  __ieee80211_scan_completed() as when
1192 	 *   SCAN_HW_SCANNING bit is set this function change
1193 	 *   local->hw_scan_req to operate on 5G band, what race with
1194 	 *   driver which can use local->hw_scan_req
1195 	 *
1196 	 * - we can not cancel scan_work since driver can schedule it
1197 	 *   by ieee80211_scan_completed(..., true) to finish scan
1198 	 *
1199 	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1200 	 * driver is still responsible for calling ieee80211_scan_completed()
1201 	 * after the scan was completed/aborted.
1202 	 */
1203 
1204 	if (!local->scan_req)
1205 		return;
1206 
1207 	/*
1208 	 * We have a scan running and the driver already reported completion,
1209 	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1210 	 * cancelled.
1211 	 */
1212 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1213 	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1214 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1215 		return;
1216 	}
1217 
1218 	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1219 		/*
1220 		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1221 		 * scan on another band.
1222 		 */
1223 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1224 		if (local->ops->cancel_hw_scan)
1225 			drv_cancel_hw_scan(local,
1226 				rcu_dereference_protected(local->scan_sdata,
1227 						lockdep_is_held(&local->hw.wiphy->mtx)));
1228 		return;
1229 	}
1230 
1231 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1232 	/* and clean up */
1233 	memset(&local->scan_info, 0, sizeof(local->scan_info));
1234 	__ieee80211_scan_completed(&local->hw, true);
1235 }
1236 
1237 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1238 					struct cfg80211_sched_scan_request *req)
1239 {
1240 	struct ieee80211_local *local = sdata->local;
1241 	struct ieee80211_scan_ies sched_scan_ies = {};
1242 	struct cfg80211_chan_def chandef;
1243 	int ret, i, iebufsz, num_bands = 0;
1244 	u32 rate_masks[NUM_NL80211_BANDS] = {};
1245 	u8 bands_used = 0;
1246 	u8 *ie;
1247 	u32 flags = 0;
1248 
1249 	lockdep_assert_wiphy(local->hw.wiphy);
1250 
1251 	iebufsz = local->scan_ies_len + req->ie_len;
1252 
1253 	if (!local->ops->sched_scan_start)
1254 		return -ENOTSUPP;
1255 
1256 	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1257 		if (local->hw.wiphy->bands[i]) {
1258 			bands_used |= BIT(i);
1259 			rate_masks[i] = (u32) -1;
1260 			num_bands++;
1261 		}
1262 	}
1263 
1264 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1265 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1266 
1267 	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1268 	if (!ie) {
1269 		ret = -ENOMEM;
1270 		goto out;
1271 	}
1272 
1273 	ieee80211_prepare_scan_chandef(&chandef);
1274 
1275 	ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1276 				 &sched_scan_ies, req->ie,
1277 				 req->ie_len, bands_used, rate_masks, &chandef,
1278 				 flags);
1279 
1280 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1281 	if (ret == 0) {
1282 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1283 		rcu_assign_pointer(local->sched_scan_req, req);
1284 	}
1285 
1286 	kfree(ie);
1287 
1288 out:
1289 	if (ret) {
1290 		/* Clean in case of failure after HW restart or upon resume. */
1291 		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1292 		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1293 	}
1294 
1295 	return ret;
1296 }
1297 
1298 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1299 				       struct cfg80211_sched_scan_request *req)
1300 {
1301 	struct ieee80211_local *local = sdata->local;
1302 
1303 	lockdep_assert_wiphy(local->hw.wiphy);
1304 
1305 	if (rcu_access_pointer(local->sched_scan_sdata))
1306 		return -EBUSY;
1307 
1308 	return __ieee80211_request_sched_scan_start(sdata, req);
1309 }
1310 
1311 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1312 {
1313 	struct ieee80211_sub_if_data *sched_scan_sdata;
1314 	int ret = -ENOENT;
1315 
1316 	lockdep_assert_wiphy(local->hw.wiphy);
1317 
1318 	if (!local->ops->sched_scan_stop)
1319 		return -ENOTSUPP;
1320 
1321 	/* We don't want to restart sched scan anymore. */
1322 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1323 
1324 	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1325 						lockdep_is_held(&local->hw.wiphy->mtx));
1326 	if (sched_scan_sdata) {
1327 		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1328 		if (!ret)
1329 			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1330 	}
1331 
1332 	return ret;
1333 }
1334 
1335 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1336 {
1337 	struct ieee80211_local *local = hw_to_local(hw);
1338 
1339 	trace_api_sched_scan_results(local);
1340 
1341 	cfg80211_sched_scan_results(hw->wiphy, 0);
1342 }
1343 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1344 
1345 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1346 {
1347 	lockdep_assert_wiphy(local->hw.wiphy);
1348 
1349 	if (!rcu_access_pointer(local->sched_scan_sdata))
1350 		return;
1351 
1352 	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1353 
1354 	/* If sched scan was aborted by the driver. */
1355 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1356 
1357 	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1358 }
1359 
1360 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1361 				       struct wiphy_work *work)
1362 {
1363 	struct ieee80211_local *local =
1364 		container_of(work, struct ieee80211_local,
1365 			     sched_scan_stopped_work);
1366 
1367 	ieee80211_sched_scan_end(local);
1368 }
1369 
1370 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1371 {
1372 	struct ieee80211_local *local = hw_to_local(hw);
1373 
1374 	trace_api_sched_scan_stopped(local);
1375 
1376 	/*
1377 	 * this shouldn't really happen, so for simplicity
1378 	 * simply ignore it, and let mac80211 reconfigure
1379 	 * the sched scan later on.
1380 	 */
1381 	if (local->in_reconfig)
1382 		return;
1383 
1384 	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1385 }
1386 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1387