xref: /kernel/linux/linux-6.6/net/mac80211/scan.c (revision 62306a36)
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
32void 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
41static 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
58struct inform_bss_update_data {
59	struct ieee80211_rx_status *rx_status;
60	bool beacon;
61};
62
63void 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
163struct ieee80211_bss *
164ieee80211_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.scan_width = NL80211_BSS_CHAN_WIDTH_20;
191	if (rx_status->bw == RATE_INFO_BW_5)
192		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
193	else if (rx_status->bw == RATE_INFO_BW_10)
194		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
195
196	bss_meta.chan = channel;
197
198	rcu_read_lock();
199	scan_sdata = rcu_dereference(local->scan_sdata);
200	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
201	    scan_sdata->vif.cfg.assoc &&
202	    ieee80211_have_rx_timestamp(rx_status)) {
203		bss_meta.parent_tsf =
204			ieee80211_calculate_rx_timestamp(local, rx_status,
205							 len + FCS_LEN, 24);
206		ether_addr_copy(bss_meta.parent_bssid,
207				scan_sdata->vif.bss_conf.bssid);
208	}
209	rcu_read_unlock();
210
211	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
212					      mgmt, len, GFP_ATOMIC);
213	if (!cbss)
214		return NULL;
215
216	/* In case the signal is invalid update the status */
217	signal_valid = channel == cbss->channel;
218	if (!signal_valid)
219		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
220
221	return (void *)cbss->priv;
222}
223
224static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
225					struct ieee80211_channel *channel,
226					u32 scan_flags, const u8 *da)
227{
228	if (!sdata)
229		return false;
230
231	/* accept broadcast on 6 GHz and for OCE */
232	if (is_broadcast_ether_addr(da) &&
233	    (channel->band == NL80211_BAND_6GHZ ||
234	     scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
235		return true;
236
237	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
238		return true;
239	return ether_addr_equal(da, sdata->vif.addr);
240}
241
242void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
243{
244	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
245	struct ieee80211_sub_if_data *sdata1, *sdata2;
246	struct ieee80211_mgmt *mgmt = (void *)skb->data;
247	struct ieee80211_bss *bss;
248	struct ieee80211_channel *channel;
249	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
250				      u.probe_resp.variable);
251
252	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
253	    !ieee80211_is_beacon(mgmt->frame_control) &&
254	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
255		return;
256
257	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
258		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
259			min_hdr_len = offsetof(struct ieee80211_ext,
260					       u.s1g_short_beacon.variable);
261		else
262			min_hdr_len = offsetof(struct ieee80211_ext,
263					       u.s1g_beacon);
264	}
265
266	if (skb->len < min_hdr_len)
267		return;
268
269	sdata1 = rcu_dereference(local->scan_sdata);
270	sdata2 = rcu_dereference(local->sched_scan_sdata);
271
272	if (likely(!sdata1 && !sdata2))
273		return;
274
275	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
276		/*
277		 * we were passive scanning because of radar/no-IR, but
278		 * the beacon/proberesp rx gives us an opportunity to upgrade
279		 * to active scan
280		 */
281		set_bit(SCAN_BEACON_DONE, &local->scanning);
282		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
283	}
284
285	channel = ieee80211_get_channel_khz(local->hw.wiphy,
286					    ieee80211_rx_status_to_khz(rx_status));
287
288	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
289		return;
290
291	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
292		struct cfg80211_scan_request *scan_req;
293		struct cfg80211_sched_scan_request *sched_scan_req;
294		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
295
296		scan_req = rcu_dereference(local->scan_req);
297		sched_scan_req = rcu_dereference(local->sched_scan_req);
298
299		if (scan_req)
300			scan_req_flags = scan_req->flags;
301
302		if (sched_scan_req)
303			sched_scan_req_flags = sched_scan_req->flags;
304
305		/* ignore ProbeResp to foreign address or non-bcast (OCE)
306		 * unless scanning with randomised address
307		 */
308		if (!ieee80211_scan_accept_presp(sdata1, channel,
309						 scan_req_flags,
310						 mgmt->da) &&
311		    !ieee80211_scan_accept_presp(sdata2, channel,
312						 sched_scan_req_flags,
313						 mgmt->da))
314			return;
315	}
316
317	bss = ieee80211_bss_info_update(local, rx_status,
318					mgmt, skb->len,
319					channel);
320	if (bss)
321		ieee80211_rx_bss_put(local, bss);
322}
323
324static void
325ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
326			       enum nl80211_bss_scan_width scan_width)
327{
328	memset(chandef, 0, sizeof(*chandef));
329	switch (scan_width) {
330	case NL80211_BSS_CHAN_WIDTH_5:
331		chandef->width = NL80211_CHAN_WIDTH_5;
332		break;
333	case NL80211_BSS_CHAN_WIDTH_10:
334		chandef->width = NL80211_CHAN_WIDTH_10;
335		break;
336	default:
337		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
338		break;
339	}
340}
341
342/* return false if no more work */
343static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
344{
345	struct ieee80211_local *local = sdata->local;
346	struct cfg80211_scan_request *req;
347	struct cfg80211_chan_def chandef;
348	u8 bands_used = 0;
349	int i, ielen, n_chans;
350	u32 flags = 0;
351
352	req = rcu_dereference_protected(local->scan_req,
353					lockdep_is_held(&local->mtx));
354
355	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
356		return false;
357
358	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
359		for (i = 0; i < req->n_channels; i++) {
360			local->hw_scan_req->req.channels[i] = req->channels[i];
361			bands_used |= BIT(req->channels[i]->band);
362		}
363
364		n_chans = req->n_channels;
365	} else {
366		do {
367			if (local->hw_scan_band == NUM_NL80211_BANDS)
368				return false;
369
370			n_chans = 0;
371
372			for (i = 0; i < req->n_channels; i++) {
373				if (req->channels[i]->band !=
374				    local->hw_scan_band)
375					continue;
376				local->hw_scan_req->req.channels[n_chans] =
377							req->channels[i];
378				n_chans++;
379				bands_used |= BIT(req->channels[i]->band);
380			}
381
382			local->hw_scan_band++;
383		} while (!n_chans);
384	}
385
386	local->hw_scan_req->req.n_channels = n_chans;
387	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
388
389	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
390		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
391
392	ielen = ieee80211_build_preq_ies(sdata,
393					 (u8 *)local->hw_scan_req->req.ie,
394					 local->hw_scan_ies_bufsize,
395					 &local->hw_scan_req->ies,
396					 req->ie, req->ie_len,
397					 bands_used, req->rates, &chandef,
398					 flags);
399	local->hw_scan_req->req.ie_len = ielen;
400	local->hw_scan_req->req.no_cck = req->no_cck;
401	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
402	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
403			req->mac_addr_mask);
404	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
405
406	return true;
407}
408
409static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
410{
411	struct ieee80211_local *local = hw_to_local(hw);
412	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
413	bool was_scanning = local->scanning;
414	struct cfg80211_scan_request *scan_req;
415	struct ieee80211_sub_if_data *scan_sdata;
416	struct ieee80211_sub_if_data *sdata;
417
418	lockdep_assert_held(&local->mtx);
419
420	/*
421	 * It's ok to abort a not-yet-running scan (that
422	 * we have one at all will be verified by checking
423	 * local->scan_req next), but not to complete it
424	 * successfully.
425	 */
426	if (WARN_ON(!local->scanning && !aborted))
427		aborted = true;
428
429	if (WARN_ON(!local->scan_req))
430		return;
431
432	scan_sdata = rcu_dereference_protected(local->scan_sdata,
433					       lockdep_is_held(&local->mtx));
434
435	if (hw_scan && !aborted &&
436	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
437	    ieee80211_prep_hw_scan(scan_sdata)) {
438		int rc;
439
440		rc = drv_hw_scan(local,
441			rcu_dereference_protected(local->scan_sdata,
442						  lockdep_is_held(&local->mtx)),
443			local->hw_scan_req);
444
445		if (rc == 0)
446			return;
447
448		/* HW scan failed and is going to be reported as aborted,
449		 * so clear old scan info.
450		 */
451		memset(&local->scan_info, 0, sizeof(local->scan_info));
452		aborted = true;
453	}
454
455	kfree(local->hw_scan_req);
456	local->hw_scan_req = NULL;
457
458	scan_req = rcu_dereference_protected(local->scan_req,
459					     lockdep_is_held(&local->mtx));
460
461	RCU_INIT_POINTER(local->scan_req, NULL);
462	RCU_INIT_POINTER(local->scan_sdata, NULL);
463
464	local->scanning = 0;
465	local->scan_chandef.chan = NULL;
466
467	synchronize_rcu();
468
469	if (scan_req != local->int_scan_req) {
470		local->scan_info.aborted = aborted;
471		cfg80211_scan_done(scan_req, &local->scan_info);
472	}
473
474	/* Set power back to normal operating levels. */
475	ieee80211_hw_config(local, 0);
476
477	if (!hw_scan && was_scanning) {
478		ieee80211_configure_filter(local);
479		drv_sw_scan_complete(local, scan_sdata);
480		ieee80211_offchannel_return(local);
481	}
482
483	ieee80211_recalc_idle(local);
484
485	ieee80211_mlme_notify_scan_completed(local);
486	ieee80211_ibss_notify_scan_completed(local);
487
488	/* Requeue all the work that might have been ignored while
489	 * the scan was in progress; if there was none this will
490	 * just be a no-op for the particular interface.
491	 */
492	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
493		if (ieee80211_sdata_running(sdata))
494			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
495	}
496
497	if (was_scanning)
498		ieee80211_start_next_roc(local);
499}
500
501void ieee80211_scan_completed(struct ieee80211_hw *hw,
502			      struct cfg80211_scan_info *info)
503{
504	struct ieee80211_local *local = hw_to_local(hw);
505
506	trace_api_scan_completed(local, info->aborted);
507
508	set_bit(SCAN_COMPLETED, &local->scanning);
509	if (info->aborted)
510		set_bit(SCAN_ABORTED, &local->scanning);
511
512	memcpy(&local->scan_info, info, sizeof(*info));
513
514	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
515}
516EXPORT_SYMBOL(ieee80211_scan_completed);
517
518static int ieee80211_start_sw_scan(struct ieee80211_local *local,
519				   struct ieee80211_sub_if_data *sdata)
520{
521	/* Software scan is not supported in multi-channel cases */
522	if (local->use_chanctx)
523		return -EOPNOTSUPP;
524
525	/*
526	 * Hardware/driver doesn't support hw_scan, so use software
527	 * scanning instead. First send a nullfunc frame with power save
528	 * bit on so that AP will buffer the frames for us while we are not
529	 * listening, then send probe requests to each channel and wait for
530	 * the responses. After all channels are scanned, tune back to the
531	 * original channel and send a nullfunc frame with power save bit
532	 * off to trigger the AP to send us all the buffered frames.
533	 *
534	 * Note that while local->sw_scanning is true everything else but
535	 * nullfunc frames and probe requests will be dropped in
536	 * ieee80211_tx_h_check_assoc().
537	 */
538	drv_sw_scan_start(local, sdata, local->scan_addr);
539
540	local->leave_oper_channel_time = jiffies;
541	local->next_scan_state = SCAN_DECISION;
542	local->scan_channel_idx = 0;
543
544	ieee80211_offchannel_stop_vifs(local);
545
546	/* ensure nullfunc is transmitted before leaving operating channel */
547	ieee80211_flush_queues(local, NULL, false);
548
549	ieee80211_configure_filter(local);
550
551	/* We need to set power level at maximum rate for scanning. */
552	ieee80211_hw_config(local, 0);
553
554	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
555
556	return 0;
557}
558
559static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
560{
561	struct ieee80211_local *local = sdata->local;
562	struct ieee80211_sub_if_data *sdata_iter;
563
564	if (!ieee80211_is_radar_required(local))
565		return true;
566
567	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
568		return false;
569
570	mutex_lock(&local->iflist_mtx);
571	list_for_each_entry(sdata_iter, &local->interfaces, list) {
572		if (sdata_iter->wdev.cac_started) {
573			mutex_unlock(&local->iflist_mtx);
574			return false;
575		}
576	}
577	mutex_unlock(&local->iflist_mtx);
578
579	return true;
580}
581
582static bool ieee80211_can_scan(struct ieee80211_local *local,
583			       struct ieee80211_sub_if_data *sdata)
584{
585	if (!__ieee80211_can_leave_ch(sdata))
586		return false;
587
588	if (!list_empty(&local->roc_list))
589		return false;
590
591	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
592	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
593		return false;
594
595	return true;
596}
597
598void ieee80211_run_deferred_scan(struct ieee80211_local *local)
599{
600	lockdep_assert_held(&local->mtx);
601
602	if (!local->scan_req || local->scanning)
603		return;
604
605	if (!ieee80211_can_scan(local,
606				rcu_dereference_protected(
607					local->scan_sdata,
608					lockdep_is_held(&local->mtx))))
609		return;
610
611	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
612				 round_jiffies_relative(0));
613}
614
615static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
616					  const u8 *src, const u8 *dst,
617					  const u8 *ssid, size_t ssid_len,
618					  const u8 *ie, size_t ie_len,
619					  u32 ratemask, u32 flags, u32 tx_flags,
620					  struct ieee80211_channel *channel)
621{
622	struct sk_buff *skb;
623
624	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
625					ssid, ssid_len,
626					ie, ie_len, flags);
627
628	if (skb) {
629		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
630			struct ieee80211_hdr *hdr = (void *)skb->data;
631			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
632			u16 sn = get_random_u16();
633
634			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
635			hdr->seq_ctrl =
636				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
637		}
638		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
639		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
640	}
641}
642
643static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
644					    unsigned long *next_delay)
645{
646	int i;
647	struct ieee80211_sub_if_data *sdata;
648	struct cfg80211_scan_request *scan_req;
649	enum nl80211_band band = local->hw.conf.chandef.chan->band;
650	u32 flags = 0, tx_flags;
651
652	scan_req = rcu_dereference_protected(local->scan_req,
653					     lockdep_is_held(&local->mtx));
654
655	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
656	if (scan_req->no_cck)
657		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
658	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
659		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
660	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
661		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
662
663	sdata = rcu_dereference_protected(local->scan_sdata,
664					  lockdep_is_held(&local->mtx));
665
666	for (i = 0; i < scan_req->n_ssids; i++)
667		ieee80211_send_scan_probe_req(
668			sdata, local->scan_addr, scan_req->bssid,
669			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
670			scan_req->ie, scan_req->ie_len,
671			scan_req->rates[band], flags,
672			tx_flags, local->hw.conf.chandef.chan);
673
674	/*
675	 * After sending probe requests, wait for probe responses
676	 * on the channel.
677	 */
678	*next_delay = IEEE80211_CHANNEL_TIME;
679	local->next_scan_state = SCAN_DECISION;
680}
681
682static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
683				  struct cfg80211_scan_request *req)
684{
685	struct ieee80211_local *local = sdata->local;
686	bool hw_scan = local->ops->hw_scan;
687	int rc;
688
689	lockdep_assert_held(&local->mtx);
690
691	if (local->scan_req)
692		return -EBUSY;
693
694	if (!__ieee80211_can_leave_ch(sdata))
695		return -EBUSY;
696
697	if (!ieee80211_can_scan(local, sdata)) {
698		/* wait for the work to finish/time out */
699		rcu_assign_pointer(local->scan_req, req);
700		rcu_assign_pointer(local->scan_sdata, sdata);
701		return 0;
702	}
703
704 again:
705	if (hw_scan) {
706		u8 *ies;
707
708		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
709
710		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
711			int i, n_bands = 0;
712			u8 bands_counted = 0;
713
714			for (i = 0; i < req->n_channels; i++) {
715				if (bands_counted & BIT(req->channels[i]->band))
716					continue;
717				bands_counted |= BIT(req->channels[i]->band);
718				n_bands++;
719			}
720
721			local->hw_scan_ies_bufsize *= n_bands;
722		}
723
724		local->hw_scan_req = kmalloc(
725				sizeof(*local->hw_scan_req) +
726				req->n_channels * sizeof(req->channels[0]) +
727				local->hw_scan_ies_bufsize, GFP_KERNEL);
728		if (!local->hw_scan_req)
729			return -ENOMEM;
730
731		local->hw_scan_req->req.ssids = req->ssids;
732		local->hw_scan_req->req.n_ssids = req->n_ssids;
733		ies = (u8 *)local->hw_scan_req +
734			sizeof(*local->hw_scan_req) +
735			req->n_channels * sizeof(req->channels[0]);
736		local->hw_scan_req->req.ie = ies;
737		local->hw_scan_req->req.flags = req->flags;
738		eth_broadcast_addr(local->hw_scan_req->req.bssid);
739		local->hw_scan_req->req.duration = req->duration;
740		local->hw_scan_req->req.duration_mandatory =
741			req->duration_mandatory;
742
743		local->hw_scan_band = 0;
744		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
745		local->hw_scan_req->req.scan_6ghz_params =
746			req->scan_6ghz_params;
747		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
748
749		/*
750		 * After allocating local->hw_scan_req, we must
751		 * go through until ieee80211_prep_hw_scan(), so
752		 * anything that might be changed here and leave
753		 * this function early must not go after this
754		 * allocation.
755		 */
756	}
757
758	rcu_assign_pointer(local->scan_req, req);
759	rcu_assign_pointer(local->scan_sdata, sdata);
760
761	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
762		get_random_mask_addr(local->scan_addr,
763				     req->mac_addr,
764				     req->mac_addr_mask);
765	else
766		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
767
768	if (hw_scan) {
769		__set_bit(SCAN_HW_SCANNING, &local->scanning);
770	} else if ((req->n_channels == 1) &&
771		   (req->channels[0] == local->_oper_chandef.chan)) {
772		/*
773		 * If we are scanning only on the operating channel
774		 * then we do not need to stop normal activities
775		 */
776		unsigned long next_delay;
777
778		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
779
780		ieee80211_recalc_idle(local);
781
782		/* Notify driver scan is starting, keep order of operations
783		 * same as normal software scan, in case that matters. */
784		drv_sw_scan_start(local, sdata, local->scan_addr);
785
786		ieee80211_configure_filter(local); /* accept probe-responses */
787
788		/* We need to ensure power level is at max for scanning. */
789		ieee80211_hw_config(local, 0);
790
791		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
792						IEEE80211_CHAN_RADAR)) ||
793		    !req->n_ssids) {
794			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
795			if (req->n_ssids)
796				set_bit(SCAN_BEACON_WAIT, &local->scanning);
797		} else {
798			ieee80211_scan_state_send_probe(local, &next_delay);
799			next_delay = IEEE80211_CHANNEL_TIME;
800		}
801
802		/* Now, just wait a bit and we are all done! */
803		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
804					 next_delay);
805		return 0;
806	} else {
807		/* Do normal software scan */
808		__set_bit(SCAN_SW_SCANNING, &local->scanning);
809	}
810
811	ieee80211_recalc_idle(local);
812
813	if (hw_scan) {
814		WARN_ON(!ieee80211_prep_hw_scan(sdata));
815		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
816	} else {
817		rc = ieee80211_start_sw_scan(local, sdata);
818	}
819
820	if (rc) {
821		kfree(local->hw_scan_req);
822		local->hw_scan_req = NULL;
823		local->scanning = 0;
824
825		ieee80211_recalc_idle(local);
826
827		local->scan_req = NULL;
828		RCU_INIT_POINTER(local->scan_sdata, NULL);
829	}
830
831	if (hw_scan && rc == 1) {
832		/*
833		 * we can't fall back to software for P2P-GO
834		 * as it must update NoA etc.
835		 */
836		if (ieee80211_vif_type_p2p(&sdata->vif) ==
837				NL80211_IFTYPE_P2P_GO)
838			return -EOPNOTSUPP;
839		hw_scan = false;
840		goto again;
841	}
842
843	return rc;
844}
845
846static unsigned long
847ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
848{
849	/*
850	 * TODO: channel switching also consumes quite some time,
851	 * add that delay as well to get a better estimation
852	 */
853	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
854		return IEEE80211_PASSIVE_CHANNEL_TIME;
855	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
856}
857
858static void ieee80211_scan_state_decision(struct ieee80211_local *local,
859					  unsigned long *next_delay)
860{
861	bool associated = false;
862	bool tx_empty = true;
863	bool bad_latency;
864	struct ieee80211_sub_if_data *sdata;
865	struct ieee80211_channel *next_chan;
866	enum mac80211_scan_state next_scan_state;
867	struct cfg80211_scan_request *scan_req;
868
869	/*
870	 * check if at least one STA interface is associated,
871	 * check if at least one STA interface has pending tx frames
872	 * and grab the lowest used beacon interval
873	 */
874	mutex_lock(&local->iflist_mtx);
875	list_for_each_entry(sdata, &local->interfaces, list) {
876		if (!ieee80211_sdata_running(sdata))
877			continue;
878
879		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
880			if (sdata->u.mgd.associated) {
881				associated = true;
882
883				if (!qdisc_all_tx_empty(sdata->dev)) {
884					tx_empty = false;
885					break;
886				}
887			}
888		}
889	}
890	mutex_unlock(&local->iflist_mtx);
891
892	scan_req = rcu_dereference_protected(local->scan_req,
893					     lockdep_is_held(&local->mtx));
894
895	next_chan = scan_req->channels[local->scan_channel_idx];
896
897	/*
898	 * we're currently scanning a different channel, let's
899	 * see if we can scan another channel without interfering
900	 * with the current traffic situation.
901	 *
902	 * Keep good latency, do not stay off-channel more than 125 ms.
903	 */
904
905	bad_latency = time_after(jiffies +
906				 ieee80211_scan_get_channel_time(next_chan),
907				 local->leave_oper_channel_time + HZ / 8);
908
909	if (associated && !tx_empty) {
910		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
911			next_scan_state = SCAN_ABORT;
912		else
913			next_scan_state = SCAN_SUSPEND;
914	} else if (associated && bad_latency) {
915		next_scan_state = SCAN_SUSPEND;
916	} else {
917		next_scan_state = SCAN_SET_CHANNEL;
918	}
919
920	local->next_scan_state = next_scan_state;
921
922	*next_delay = 0;
923}
924
925static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
926					     unsigned long *next_delay)
927{
928	int skip;
929	struct ieee80211_channel *chan;
930	enum nl80211_bss_scan_width oper_scan_width;
931	struct cfg80211_scan_request *scan_req;
932
933	scan_req = rcu_dereference_protected(local->scan_req,
934					     lockdep_is_held(&local->mtx));
935
936	skip = 0;
937	chan = scan_req->channels[local->scan_channel_idx];
938
939	local->scan_chandef.chan = chan;
940	local->scan_chandef.center_freq1 = chan->center_freq;
941	local->scan_chandef.freq1_offset = chan->freq_offset;
942	local->scan_chandef.center_freq2 = 0;
943
944	/* For scanning on the S1G band, ignore scan_width (which is constant
945	 * across all channels) for now since channel width is specific to each
946	 * channel. Detect the required channel width here and likely revisit
947	 * later. Maybe scan_width could be used to build the channel scan list?
948	 */
949	if (chan->band == NL80211_BAND_S1GHZ) {
950		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
951		goto set_channel;
952	}
953
954	switch (scan_req->scan_width) {
955	case NL80211_BSS_CHAN_WIDTH_5:
956		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
957		break;
958	case NL80211_BSS_CHAN_WIDTH_10:
959		local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
960		break;
961	default:
962	case NL80211_BSS_CHAN_WIDTH_20:
963		/* If scanning on oper channel, use whatever channel-type
964		 * is currently in use.
965		 */
966		oper_scan_width = cfg80211_chandef_to_scan_width(
967					&local->_oper_chandef);
968		if (chan == local->_oper_chandef.chan &&
969		    oper_scan_width == scan_req->scan_width)
970			local->scan_chandef = local->_oper_chandef;
971		else
972			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
973		break;
974	case NL80211_BSS_CHAN_WIDTH_1:
975	case NL80211_BSS_CHAN_WIDTH_2:
976		/* shouldn't get here, S1G handled above */
977		WARN_ON(1);
978		break;
979	}
980
981set_channel:
982	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
983		skip = 1;
984
985	/* advance state machine to next channel/band */
986	local->scan_channel_idx++;
987
988	if (skip) {
989		/* if we skip this channel return to the decision state */
990		local->next_scan_state = SCAN_DECISION;
991		return;
992	}
993
994	/*
995	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
996	 * (which unfortunately doesn't say _why_ step a) is done,
997	 * but it waits for the probe delay or until a frame is
998	 * received - and the received frame would update the NAV).
999	 * For now, we do not support waiting until a frame is
1000	 * received.
1001	 *
1002	 * In any case, it is not necessary for a passive scan.
1003	 */
1004	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1005	    !scan_req->n_ssids) {
1006		*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1007		local->next_scan_state = SCAN_DECISION;
1008		if (scan_req->n_ssids)
1009			set_bit(SCAN_BEACON_WAIT, &local->scanning);
1010		return;
1011	}
1012
1013	/* active scan, send probes */
1014	*next_delay = IEEE80211_PROBE_DELAY;
1015	local->next_scan_state = SCAN_SEND_PROBE;
1016}
1017
1018static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1019					 unsigned long *next_delay)
1020{
1021	/* switch back to the operating channel */
1022	local->scan_chandef.chan = NULL;
1023	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1024
1025	/* disable PS */
1026	ieee80211_offchannel_return(local);
1027
1028	*next_delay = HZ / 5;
1029	/* afterwards, resume scan & go to next channel */
1030	local->next_scan_state = SCAN_RESUME;
1031}
1032
1033static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1034					unsigned long *next_delay)
1035{
1036	ieee80211_offchannel_stop_vifs(local);
1037
1038	if (local->ops->flush) {
1039		ieee80211_flush_queues(local, NULL, false);
1040		*next_delay = 0;
1041	} else
1042		*next_delay = HZ / 10;
1043
1044	/* remember when we left the operating channel */
1045	local->leave_oper_channel_time = jiffies;
1046
1047	/* advance to the next channel to be scanned */
1048	local->next_scan_state = SCAN_SET_CHANNEL;
1049}
1050
1051void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1052{
1053	struct ieee80211_local *local =
1054		container_of(work, struct ieee80211_local, scan_work.work);
1055	struct ieee80211_sub_if_data *sdata;
1056	struct cfg80211_scan_request *scan_req;
1057	unsigned long next_delay = 0;
1058	bool aborted;
1059
1060	mutex_lock(&local->mtx);
1061
1062	if (!ieee80211_can_run_worker(local)) {
1063		aborted = true;
1064		goto out_complete;
1065	}
1066
1067	sdata = rcu_dereference_protected(local->scan_sdata,
1068					  lockdep_is_held(&local->mtx));
1069	scan_req = rcu_dereference_protected(local->scan_req,
1070					     lockdep_is_held(&local->mtx));
1071
1072	/* When scanning on-channel, the first-callback means completed. */
1073	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1074		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1075		goto out_complete;
1076	}
1077
1078	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1079		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1080		goto out_complete;
1081	}
1082
1083	if (!sdata || !scan_req)
1084		goto out;
1085
1086	if (!local->scanning) {
1087		int rc;
1088
1089		RCU_INIT_POINTER(local->scan_req, NULL);
1090		RCU_INIT_POINTER(local->scan_sdata, NULL);
1091
1092		rc = __ieee80211_start_scan(sdata, scan_req);
1093		if (rc) {
1094			/* need to complete scan in cfg80211 */
1095			rcu_assign_pointer(local->scan_req, scan_req);
1096			aborted = true;
1097			goto out_complete;
1098		} else
1099			goto out;
1100	}
1101
1102	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1103
1104	/*
1105	 * as long as no delay is required advance immediately
1106	 * without scheduling a new work
1107	 */
1108	do {
1109		if (!ieee80211_sdata_running(sdata)) {
1110			aborted = true;
1111			goto out_complete;
1112		}
1113
1114		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1115		    local->next_scan_state == SCAN_DECISION)
1116			local->next_scan_state = SCAN_SEND_PROBE;
1117
1118		switch (local->next_scan_state) {
1119		case SCAN_DECISION:
1120			/* if no more bands/channels left, complete scan */
1121			if (local->scan_channel_idx >= scan_req->n_channels) {
1122				aborted = false;
1123				goto out_complete;
1124			}
1125			ieee80211_scan_state_decision(local, &next_delay);
1126			break;
1127		case SCAN_SET_CHANNEL:
1128			ieee80211_scan_state_set_channel(local, &next_delay);
1129			break;
1130		case SCAN_SEND_PROBE:
1131			ieee80211_scan_state_send_probe(local, &next_delay);
1132			break;
1133		case SCAN_SUSPEND:
1134			ieee80211_scan_state_suspend(local, &next_delay);
1135			break;
1136		case SCAN_RESUME:
1137			ieee80211_scan_state_resume(local, &next_delay);
1138			break;
1139		case SCAN_ABORT:
1140			aborted = true;
1141			goto out_complete;
1142		}
1143	} while (next_delay == 0);
1144
1145	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1146				 next_delay);
1147	goto out;
1148
1149out_complete:
1150	__ieee80211_scan_completed(&local->hw, aborted);
1151out:
1152	mutex_unlock(&local->mtx);
1153}
1154
1155int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1156			   struct cfg80211_scan_request *req)
1157{
1158	int res;
1159
1160	mutex_lock(&sdata->local->mtx);
1161	res = __ieee80211_start_scan(sdata, req);
1162	mutex_unlock(&sdata->local->mtx);
1163
1164	return res;
1165}
1166
1167int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1168				const u8 *ssid, u8 ssid_len,
1169				struct ieee80211_channel **channels,
1170				unsigned int n_channels,
1171				enum nl80211_bss_scan_width scan_width)
1172{
1173	struct ieee80211_local *local = sdata->local;
1174	int ret = -EBUSY, i, n_ch = 0;
1175	enum nl80211_band band;
1176
1177	mutex_lock(&local->mtx);
1178
1179	/* busy scanning */
1180	if (local->scan_req)
1181		goto unlock;
1182
1183	/* fill internal scan request */
1184	if (!channels) {
1185		int max_n;
1186
1187		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1188			if (!local->hw.wiphy->bands[band] ||
1189			    band == NL80211_BAND_6GHZ)
1190				continue;
1191
1192			max_n = local->hw.wiphy->bands[band]->n_channels;
1193			for (i = 0; i < max_n; i++) {
1194				struct ieee80211_channel *tmp_ch =
1195				    &local->hw.wiphy->bands[band]->channels[i];
1196
1197				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1198						     IEEE80211_CHAN_DISABLED))
1199					continue;
1200
1201				local->int_scan_req->channels[n_ch] = tmp_ch;
1202				n_ch++;
1203			}
1204		}
1205
1206		if (WARN_ON_ONCE(n_ch == 0))
1207			goto unlock;
1208
1209		local->int_scan_req->n_channels = n_ch;
1210	} else {
1211		for (i = 0; i < n_channels; i++) {
1212			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1213						  IEEE80211_CHAN_DISABLED))
1214				continue;
1215
1216			local->int_scan_req->channels[n_ch] = channels[i];
1217			n_ch++;
1218		}
1219
1220		if (WARN_ON_ONCE(n_ch == 0))
1221			goto unlock;
1222
1223		local->int_scan_req->n_channels = n_ch;
1224	}
1225
1226	local->int_scan_req->ssids = &local->scan_ssid;
1227	local->int_scan_req->n_ssids = 1;
1228	local->int_scan_req->scan_width = scan_width;
1229	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1230	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1231
1232	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1233 unlock:
1234	mutex_unlock(&local->mtx);
1235	return ret;
1236}
1237
1238void ieee80211_scan_cancel(struct ieee80211_local *local)
1239{
1240	/* ensure a new scan cannot be queued */
1241	lockdep_assert_wiphy(local->hw.wiphy);
1242
1243	/*
1244	 * We are canceling software scan, or deferred scan that was not
1245	 * yet really started (see __ieee80211_start_scan ).
1246	 *
1247	 * Regarding hardware scan:
1248	 * - we can not call  __ieee80211_scan_completed() as when
1249	 *   SCAN_HW_SCANNING bit is set this function change
1250	 *   local->hw_scan_req to operate on 5G band, what race with
1251	 *   driver which can use local->hw_scan_req
1252	 *
1253	 * - we can not cancel scan_work since driver can schedule it
1254	 *   by ieee80211_scan_completed(..., true) to finish scan
1255	 *
1256	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1257	 * driver is still responsible for calling ieee80211_scan_completed()
1258	 * after the scan was completed/aborted.
1259	 */
1260
1261	mutex_lock(&local->mtx);
1262	if (!local->scan_req)
1263		goto out;
1264
1265	/*
1266	 * We have a scan running and the driver already reported completion,
1267	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1268	 * cancelled.
1269	 */
1270	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1271	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1272		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1273		goto out;
1274	}
1275
1276	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1277		/*
1278		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1279		 * scan on another band.
1280		 */
1281		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1282		if (local->ops->cancel_hw_scan)
1283			drv_cancel_hw_scan(local,
1284				rcu_dereference_protected(local->scan_sdata,
1285						lockdep_is_held(&local->mtx)));
1286		goto out;
1287	}
1288
1289	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1290	/* and clean up */
1291	memset(&local->scan_info, 0, sizeof(local->scan_info));
1292	__ieee80211_scan_completed(&local->hw, true);
1293out:
1294	mutex_unlock(&local->mtx);
1295}
1296
1297int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1298					struct cfg80211_sched_scan_request *req)
1299{
1300	struct ieee80211_local *local = sdata->local;
1301	struct ieee80211_scan_ies sched_scan_ies = {};
1302	struct cfg80211_chan_def chandef;
1303	int ret, i, iebufsz, num_bands = 0;
1304	u32 rate_masks[NUM_NL80211_BANDS] = {};
1305	u8 bands_used = 0;
1306	u8 *ie;
1307	u32 flags = 0;
1308
1309	iebufsz = local->scan_ies_len + req->ie_len;
1310
1311	lockdep_assert_held(&local->mtx);
1312
1313	if (!local->ops->sched_scan_start)
1314		return -ENOTSUPP;
1315
1316	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1317		if (local->hw.wiphy->bands[i]) {
1318			bands_used |= BIT(i);
1319			rate_masks[i] = (u32) -1;
1320			num_bands++;
1321		}
1322	}
1323
1324	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1325		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1326
1327	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1328	if (!ie) {
1329		ret = -ENOMEM;
1330		goto out;
1331	}
1332
1333	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1334
1335	ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1336				 &sched_scan_ies, req->ie,
1337				 req->ie_len, bands_used, rate_masks, &chandef,
1338				 flags);
1339
1340	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1341	if (ret == 0) {
1342		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1343		rcu_assign_pointer(local->sched_scan_req, req);
1344	}
1345
1346	kfree(ie);
1347
1348out:
1349	if (ret) {
1350		/* Clean in case of failure after HW restart or upon resume. */
1351		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1352		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1353	}
1354
1355	return ret;
1356}
1357
1358int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1359				       struct cfg80211_sched_scan_request *req)
1360{
1361	struct ieee80211_local *local = sdata->local;
1362	int ret;
1363
1364	mutex_lock(&local->mtx);
1365
1366	if (rcu_access_pointer(local->sched_scan_sdata)) {
1367		mutex_unlock(&local->mtx);
1368		return -EBUSY;
1369	}
1370
1371	ret = __ieee80211_request_sched_scan_start(sdata, req);
1372
1373	mutex_unlock(&local->mtx);
1374	return ret;
1375}
1376
1377int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1378{
1379	struct ieee80211_sub_if_data *sched_scan_sdata;
1380	int ret = -ENOENT;
1381
1382	mutex_lock(&local->mtx);
1383
1384	if (!local->ops->sched_scan_stop) {
1385		ret = -ENOTSUPP;
1386		goto out;
1387	}
1388
1389	/* We don't want to restart sched scan anymore. */
1390	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1391
1392	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1393						lockdep_is_held(&local->mtx));
1394	if (sched_scan_sdata) {
1395		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1396		if (!ret)
1397			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1398	}
1399out:
1400	mutex_unlock(&local->mtx);
1401
1402	return ret;
1403}
1404
1405void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1406{
1407	struct ieee80211_local *local = hw_to_local(hw);
1408
1409	trace_api_sched_scan_results(local);
1410
1411	cfg80211_sched_scan_results(hw->wiphy, 0);
1412}
1413EXPORT_SYMBOL(ieee80211_sched_scan_results);
1414
1415void ieee80211_sched_scan_end(struct ieee80211_local *local)
1416{
1417	mutex_lock(&local->mtx);
1418
1419	if (!rcu_access_pointer(local->sched_scan_sdata)) {
1420		mutex_unlock(&local->mtx);
1421		return;
1422	}
1423
1424	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1425
1426	/* If sched scan was aborted by the driver. */
1427	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1428
1429	mutex_unlock(&local->mtx);
1430
1431	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1432}
1433
1434void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1435				       struct wiphy_work *work)
1436{
1437	struct ieee80211_local *local =
1438		container_of(work, struct ieee80211_local,
1439			     sched_scan_stopped_work);
1440
1441	ieee80211_sched_scan_end(local);
1442}
1443
1444void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1445{
1446	struct ieee80211_local *local = hw_to_local(hw);
1447
1448	trace_api_sched_scan_stopped(local);
1449
1450	/*
1451	 * this shouldn't really happen, so for simplicity
1452	 * simply ignore it, and let mac80211 reconfigure
1453	 * the sched scan later on.
1454	 */
1455	if (local->in_reconfig)
1456		return;
1457
1458	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1459}
1460EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1461