xref: /kernel/linux/linux-5.10/net/mac80211/scan.c (revision 8c2ecf20)
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) 2018-2020 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
58static void
59ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60				struct ieee80211_bss *bss,
61				struct ieee802_11_elems *elems,
62				struct ieee80211_rx_status *rx_status,
63				bool beacon)
64{
65	int clen, srlen;
66
67	if (beacon)
68		bss->device_ts_beacon = rx_status->device_timestamp;
69	else
70		bss->device_ts_presp = rx_status->device_timestamp;
71
72	if (elems->parse_error) {
73		if (beacon)
74			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75		else
76			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77	} else {
78		if (beacon)
79			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80		else
81			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82	}
83
84	/* save the ERP value so that it is available at association time */
85	if (elems->erp_info && (!elems->parse_error ||
86				!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87		bss->erp_value = elems->erp_info[0];
88		bss->has_erp_value = true;
89		if (!elems->parse_error)
90			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91	}
92
93	/* replace old supported rates if we get new values */
94	if (!elems->parse_error ||
95	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96		srlen = 0;
97		if (elems->supp_rates) {
98			clen = IEEE80211_MAX_SUPP_RATES;
99			if (clen > elems->supp_rates_len)
100				clen = elems->supp_rates_len;
101			memcpy(bss->supp_rates, elems->supp_rates, clen);
102			srlen += clen;
103		}
104		if (elems->ext_supp_rates) {
105			clen = IEEE80211_MAX_SUPP_RATES - srlen;
106			if (clen > elems->ext_supp_rates_len)
107				clen = elems->ext_supp_rates_len;
108			memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109			       clen);
110			srlen += clen;
111		}
112		if (srlen) {
113			bss->supp_rates_len = srlen;
114			if (!elems->parse_error)
115				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116		}
117	}
118
119	if (!elems->parse_error ||
120	    !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121		bss->wmm_used = elems->wmm_param || elems->wmm_info;
122		bss->uapsd_supported = is_uapsd_supported(elems);
123		if (!elems->parse_error)
124			bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125	}
126
127	if (beacon) {
128		struct ieee80211_supported_band *sband =
129			local->hw.wiphy->bands[rx_status->band];
130		if (!(rx_status->encoding == RX_ENC_HT) &&
131		    !(rx_status->encoding == RX_ENC_VHT))
132			bss->beacon_rate =
133				&sband->bitrates[rx_status->rate_idx];
134	}
135
136	if (elems->vht_cap_elem)
137		bss->vht_cap_info =
138			le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
139	else
140		bss->vht_cap_info = 0;
141}
142
143struct ieee80211_bss *
144ieee80211_bss_info_update(struct ieee80211_local *local,
145			  struct ieee80211_rx_status *rx_status,
146			  struct ieee80211_mgmt *mgmt, size_t len,
147			  struct ieee80211_channel *channel)
148{
149	bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150		      ieee80211_is_s1g_beacon(mgmt->frame_control);
151	struct cfg80211_bss *cbss, *non_tx_cbss;
152	struct ieee80211_bss *bss, *non_tx_bss;
153	struct cfg80211_inform_bss bss_meta = {
154		.boottime_ns = rx_status->boottime_ns,
155	};
156	bool signal_valid;
157	struct ieee80211_sub_if_data *scan_sdata;
158	struct ieee802_11_elems elems;
159	size_t baselen;
160	u8 *elements;
161
162	if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163		bss_meta.signal = 0; /* invalid signal indication */
164	else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165		bss_meta.signal = rx_status->signal * 100;
166	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
168
169	bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170	if (rx_status->bw == RATE_INFO_BW_5)
171		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172	else if (rx_status->bw == RATE_INFO_BW_10)
173		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
174
175	bss_meta.chan = channel;
176
177	rcu_read_lock();
178	scan_sdata = rcu_dereference(local->scan_sdata);
179	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180	    scan_sdata->vif.bss_conf.assoc &&
181	    ieee80211_have_rx_timestamp(rx_status)) {
182		bss_meta.parent_tsf =
183			ieee80211_calculate_rx_timestamp(local, rx_status,
184							 len + FCS_LEN, 24);
185		ether_addr_copy(bss_meta.parent_bssid,
186				scan_sdata->vif.bss_conf.bssid);
187	}
188	rcu_read_unlock();
189
190	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191					      mgmt, len, GFP_ATOMIC);
192	if (!cbss)
193		return NULL;
194
195	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196		elements = mgmt->u.probe_resp.variable;
197		baselen = offsetof(struct ieee80211_mgmt,
198				   u.probe_resp.variable);
199	} else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200		struct ieee80211_ext *ext = (void *) mgmt;
201
202		baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203		elements = ext->u.s1g_beacon.variable;
204	} else {
205		baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206		elements = mgmt->u.beacon.variable;
207	}
208
209	if (baselen > len)
210		return NULL;
211
212	ieee802_11_parse_elems(elements, len - baselen, false, &elems,
213			       mgmt->bssid, cbss->bssid);
214
215	/* In case the signal is invalid update the status */
216	signal_valid = channel == cbss->channel;
217	if (!signal_valid)
218		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
219
220	bss = (void *)cbss->priv;
221	ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
222
223	list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
224		non_tx_bss = (void *)non_tx_cbss->priv;
225
226		ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
227						rx_status, beacon);
228	}
229
230	kfree(elems.nontx_profile);
231
232	return bss;
233}
234
235static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
236					u32 scan_flags, const u8 *da)
237{
238	if (!sdata)
239		return false;
240	/* accept broadcast for OCE */
241	if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
242	    is_broadcast_ether_addr(da))
243		return true;
244	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
245		return true;
246	return ether_addr_equal(da, sdata->vif.addr);
247}
248
249void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
250{
251	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
252	struct ieee80211_sub_if_data *sdata1, *sdata2;
253	struct ieee80211_mgmt *mgmt = (void *)skb->data;
254	struct ieee80211_bss *bss;
255	struct ieee80211_channel *channel;
256	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
257				      u.probe_resp.variable);
258
259	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
260	    !ieee80211_is_beacon(mgmt->frame_control) &&
261	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
262		return;
263
264	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
265		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
266			min_hdr_len = offsetof(struct ieee80211_ext,
267					       u.s1g_short_beacon.variable);
268		else
269			min_hdr_len = offsetof(struct ieee80211_ext,
270					       u.s1g_beacon);
271	}
272
273	if (skb->len < min_hdr_len)
274		return;
275
276	sdata1 = rcu_dereference(local->scan_sdata);
277	sdata2 = rcu_dereference(local->sched_scan_sdata);
278
279	if (likely(!sdata1 && !sdata2))
280		return;
281
282	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
283		/*
284		 * we were passive scanning because of radar/no-IR, but
285		 * the beacon/proberesp rx gives us an opportunity to upgrade
286		 * to active scan
287		 */
288		 set_bit(SCAN_BEACON_DONE, &local->scanning);
289		 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
290	}
291
292	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
293		struct cfg80211_scan_request *scan_req;
294		struct cfg80211_sched_scan_request *sched_scan_req;
295		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
296
297		scan_req = rcu_dereference(local->scan_req);
298		sched_scan_req = rcu_dereference(local->sched_scan_req);
299
300		if (scan_req)
301			scan_req_flags = scan_req->flags;
302
303		if (sched_scan_req)
304			sched_scan_req_flags = sched_scan_req->flags;
305
306		/* ignore ProbeResp to foreign address or non-bcast (OCE)
307		 * unless scanning with randomised address
308		 */
309		if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
310						 mgmt->da) &&
311		    !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
312						 mgmt->da))
313			return;
314	}
315
316	channel = ieee80211_get_channel_khz(local->hw.wiphy,
317					ieee80211_rx_status_to_khz(rx_status));
318
319	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
320		return;
321
322	bss = ieee80211_bss_info_update(local, rx_status,
323					mgmt, skb->len,
324					channel);
325	if (bss)
326		ieee80211_rx_bss_put(local, bss);
327}
328
329static void
330ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
331			       enum nl80211_bss_scan_width scan_width)
332{
333	memset(chandef, 0, sizeof(*chandef));
334	switch (scan_width) {
335	case NL80211_BSS_CHAN_WIDTH_5:
336		chandef->width = NL80211_CHAN_WIDTH_5;
337		break;
338	case NL80211_BSS_CHAN_WIDTH_10:
339		chandef->width = NL80211_CHAN_WIDTH_10;
340		break;
341	default:
342		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
343		break;
344	}
345}
346
347/* return false if no more work */
348static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
349{
350	struct ieee80211_local *local = sdata->local;
351	struct cfg80211_scan_request *req;
352	struct cfg80211_chan_def chandef;
353	u8 bands_used = 0;
354	int i, ielen, n_chans;
355	u32 flags = 0;
356
357	req = rcu_dereference_protected(local->scan_req,
358					lockdep_is_held(&local->mtx));
359
360	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
361		return false;
362
363	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
364		for (i = 0; i < req->n_channels; i++) {
365			local->hw_scan_req->req.channels[i] = req->channels[i];
366			bands_used |= BIT(req->channels[i]->band);
367		}
368
369		n_chans = req->n_channels;
370	} else {
371		do {
372			if (local->hw_scan_band == NUM_NL80211_BANDS)
373				return false;
374
375			n_chans = 0;
376
377			for (i = 0; i < req->n_channels; i++) {
378				if (req->channels[i]->band !=
379				    local->hw_scan_band)
380					continue;
381				local->hw_scan_req->req.channels[n_chans] =
382							req->channels[i];
383				n_chans++;
384				bands_used |= BIT(req->channels[i]->band);
385			}
386
387			local->hw_scan_band++;
388		} while (!n_chans);
389	}
390
391	local->hw_scan_req->req.n_channels = n_chans;
392	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
393
394	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
395		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
396
397	ielen = ieee80211_build_preq_ies(sdata,
398					 (u8 *)local->hw_scan_req->req.ie,
399					 local->hw_scan_ies_bufsize,
400					 &local->hw_scan_req->ies,
401					 req->ie, req->ie_len,
402					 bands_used, req->rates, &chandef,
403					 flags);
404	local->hw_scan_req->req.ie_len = ielen;
405	local->hw_scan_req->req.no_cck = req->no_cck;
406	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
407	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
408			req->mac_addr_mask);
409	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
410
411	return true;
412}
413
414static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
415{
416	struct ieee80211_local *local = hw_to_local(hw);
417	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
418	bool was_scanning = local->scanning;
419	struct cfg80211_scan_request *scan_req;
420	struct ieee80211_sub_if_data *scan_sdata;
421	struct ieee80211_sub_if_data *sdata;
422
423	lockdep_assert_held(&local->mtx);
424
425	/*
426	 * It's ok to abort a not-yet-running scan (that
427	 * we have one at all will be verified by checking
428	 * local->scan_req next), but not to complete it
429	 * successfully.
430	 */
431	if (WARN_ON(!local->scanning && !aborted))
432		aborted = true;
433
434	if (WARN_ON(!local->scan_req))
435		return;
436
437	scan_sdata = rcu_dereference_protected(local->scan_sdata,
438					       lockdep_is_held(&local->mtx));
439
440	if (hw_scan && !aborted &&
441	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
442	    ieee80211_prep_hw_scan(scan_sdata)) {
443		int rc;
444
445		rc = drv_hw_scan(local,
446			rcu_dereference_protected(local->scan_sdata,
447						  lockdep_is_held(&local->mtx)),
448			local->hw_scan_req);
449
450		if (rc == 0)
451			return;
452
453		/* HW scan failed and is going to be reported as aborted,
454		 * so clear old scan info.
455		 */
456		memset(&local->scan_info, 0, sizeof(local->scan_info));
457		aborted = true;
458	}
459
460	kfree(local->hw_scan_req);
461	local->hw_scan_req = NULL;
462
463	scan_req = rcu_dereference_protected(local->scan_req,
464					     lockdep_is_held(&local->mtx));
465
466	RCU_INIT_POINTER(local->scan_req, NULL);
467	RCU_INIT_POINTER(local->scan_sdata, NULL);
468
469	local->scanning = 0;
470	local->scan_chandef.chan = NULL;
471
472	synchronize_rcu();
473
474	if (scan_req != local->int_scan_req) {
475		local->scan_info.aborted = aborted;
476		cfg80211_scan_done(scan_req, &local->scan_info);
477	}
478
479	/* Set power back to normal operating levels. */
480	ieee80211_hw_config(local, 0);
481
482	if (!hw_scan) {
483		ieee80211_configure_filter(local);
484		drv_sw_scan_complete(local, scan_sdata);
485		ieee80211_offchannel_return(local);
486	}
487
488	ieee80211_recalc_idle(local);
489
490	ieee80211_mlme_notify_scan_completed(local);
491	ieee80211_ibss_notify_scan_completed(local);
492
493	/* Requeue all the work that might have been ignored while
494	 * the scan was in progress; if there was none this will
495	 * just be a no-op for the particular interface.
496	 */
497	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
498		if (ieee80211_sdata_running(sdata))
499			ieee80211_queue_work(&sdata->local->hw, &sdata->work);
500	}
501
502	if (was_scanning)
503		ieee80211_start_next_roc(local);
504}
505
506void ieee80211_scan_completed(struct ieee80211_hw *hw,
507			      struct cfg80211_scan_info *info)
508{
509	struct ieee80211_local *local = hw_to_local(hw);
510
511	trace_api_scan_completed(local, info->aborted);
512
513	set_bit(SCAN_COMPLETED, &local->scanning);
514	if (info->aborted)
515		set_bit(SCAN_ABORTED, &local->scanning);
516
517	memcpy(&local->scan_info, info, sizeof(*info));
518
519	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
520}
521EXPORT_SYMBOL(ieee80211_scan_completed);
522
523static int ieee80211_start_sw_scan(struct ieee80211_local *local,
524				   struct ieee80211_sub_if_data *sdata)
525{
526	/* Software scan is not supported in multi-channel cases */
527	if (local->use_chanctx)
528		return -EOPNOTSUPP;
529
530	/*
531	 * Hardware/driver doesn't support hw_scan, so use software
532	 * scanning instead. First send a nullfunc frame with power save
533	 * bit on so that AP will buffer the frames for us while we are not
534	 * listening, then send probe requests to each channel and wait for
535	 * the responses. After all channels are scanned, tune back to the
536	 * original channel and send a nullfunc frame with power save bit
537	 * off to trigger the AP to send us all the buffered frames.
538	 *
539	 * Note that while local->sw_scanning is true everything else but
540	 * nullfunc frames and probe requests will be dropped in
541	 * ieee80211_tx_h_check_assoc().
542	 */
543	drv_sw_scan_start(local, sdata, local->scan_addr);
544
545	local->leave_oper_channel_time = jiffies;
546	local->next_scan_state = SCAN_DECISION;
547	local->scan_channel_idx = 0;
548
549	ieee80211_offchannel_stop_vifs(local);
550
551	/* ensure nullfunc is transmitted before leaving operating channel */
552	ieee80211_flush_queues(local, NULL, false);
553
554	ieee80211_configure_filter(local);
555
556	/* We need to set power level at maximum rate for scanning. */
557	ieee80211_hw_config(local, 0);
558
559	ieee80211_queue_delayed_work(&local->hw,
560				     &local->scan_work, 0);
561
562	return 0;
563}
564
565static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
566{
567	struct ieee80211_local *local = sdata->local;
568	struct ieee80211_sub_if_data *sdata_iter;
569
570	if (!ieee80211_is_radar_required(local))
571		return true;
572
573	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
574		return false;
575
576	mutex_lock(&local->iflist_mtx);
577	list_for_each_entry(sdata_iter, &local->interfaces, list) {
578		if (sdata_iter->wdev.cac_started) {
579			mutex_unlock(&local->iflist_mtx);
580			return false;
581		}
582	}
583	mutex_unlock(&local->iflist_mtx);
584
585	return true;
586}
587
588static bool ieee80211_can_scan(struct ieee80211_local *local,
589			       struct ieee80211_sub_if_data *sdata)
590{
591	if (!__ieee80211_can_leave_ch(sdata))
592		return false;
593
594	if (!list_empty(&local->roc_list))
595		return false;
596
597	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
598	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
599		return false;
600
601	return true;
602}
603
604void ieee80211_run_deferred_scan(struct ieee80211_local *local)
605{
606	lockdep_assert_held(&local->mtx);
607
608	if (!local->scan_req || local->scanning)
609		return;
610
611	if (!ieee80211_can_scan(local,
612				rcu_dereference_protected(
613					local->scan_sdata,
614					lockdep_is_held(&local->mtx))))
615		return;
616
617	ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
618				     round_jiffies_relative(0));
619}
620
621static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
622					  const u8 *src, const u8 *dst,
623					  const u8 *ssid, size_t ssid_len,
624					  const u8 *ie, size_t ie_len,
625					  u32 ratemask, u32 flags, u32 tx_flags,
626					  struct ieee80211_channel *channel)
627{
628	struct sk_buff *skb;
629
630	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
631					ssid, ssid_len,
632					ie, ie_len, flags);
633
634	if (skb) {
635		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
636			struct ieee80211_hdr *hdr = (void *)skb->data;
637			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
638			u16 sn = get_random_u32();
639
640			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
641			hdr->seq_ctrl =
642				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
643		}
644		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
645		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
646	}
647}
648
649static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
650					    unsigned long *next_delay)
651{
652	int i;
653	struct ieee80211_sub_if_data *sdata;
654	struct cfg80211_scan_request *scan_req;
655	enum nl80211_band band = local->hw.conf.chandef.chan->band;
656	u32 flags = 0, tx_flags;
657
658	scan_req = rcu_dereference_protected(local->scan_req,
659					     lockdep_is_held(&local->mtx));
660
661	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
662	if (scan_req->no_cck)
663		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
664	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
665		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
666	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
667		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
668
669	sdata = rcu_dereference_protected(local->scan_sdata,
670					  lockdep_is_held(&local->mtx));
671
672	for (i = 0; i < scan_req->n_ssids; i++)
673		ieee80211_send_scan_probe_req(
674			sdata, local->scan_addr, scan_req->bssid,
675			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
676			scan_req->ie, scan_req->ie_len,
677			scan_req->rates[band], flags,
678			tx_flags, local->hw.conf.chandef.chan);
679
680	/*
681	 * After sending probe requests, wait for probe responses
682	 * on the channel.
683	 */
684	*next_delay = IEEE80211_CHANNEL_TIME;
685	local->next_scan_state = SCAN_DECISION;
686}
687
688static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
689				  struct cfg80211_scan_request *req)
690{
691	struct ieee80211_local *local = sdata->local;
692	bool hw_scan = local->ops->hw_scan;
693	int rc;
694
695	lockdep_assert_held(&local->mtx);
696
697	if (local->scan_req)
698		return -EBUSY;
699
700	if (!__ieee80211_can_leave_ch(sdata))
701		return -EBUSY;
702
703	if (!ieee80211_can_scan(local, sdata)) {
704		/* wait for the work to finish/time out */
705		rcu_assign_pointer(local->scan_req, req);
706		rcu_assign_pointer(local->scan_sdata, sdata);
707		return 0;
708	}
709
710 again:
711	if (hw_scan) {
712		u8 *ies;
713
714		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
715
716		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
717			int i, n_bands = 0;
718			u8 bands_counted = 0;
719
720			for (i = 0; i < req->n_channels; i++) {
721				if (bands_counted & BIT(req->channels[i]->band))
722					continue;
723				bands_counted |= BIT(req->channels[i]->band);
724				n_bands++;
725			}
726
727			local->hw_scan_ies_bufsize *= n_bands;
728		}
729
730		local->hw_scan_req = kmalloc(
731				sizeof(*local->hw_scan_req) +
732				req->n_channels * sizeof(req->channels[0]) +
733				local->hw_scan_ies_bufsize, GFP_KERNEL);
734		if (!local->hw_scan_req)
735			return -ENOMEM;
736
737		local->hw_scan_req->req.ssids = req->ssids;
738		local->hw_scan_req->req.n_ssids = req->n_ssids;
739		ies = (u8 *)local->hw_scan_req +
740			sizeof(*local->hw_scan_req) +
741			req->n_channels * sizeof(req->channels[0]);
742		local->hw_scan_req->req.ie = ies;
743		local->hw_scan_req->req.flags = req->flags;
744		eth_broadcast_addr(local->hw_scan_req->req.bssid);
745		local->hw_scan_req->req.duration = req->duration;
746		local->hw_scan_req->req.duration_mandatory =
747			req->duration_mandatory;
748
749		local->hw_scan_band = 0;
750		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
751		local->hw_scan_req->req.scan_6ghz_params =
752			req->scan_6ghz_params;
753		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
754
755		/*
756		 * After allocating local->hw_scan_req, we must
757		 * go through until ieee80211_prep_hw_scan(), so
758		 * anything that might be changed here and leave
759		 * this function early must not go after this
760		 * allocation.
761		 */
762	}
763
764	rcu_assign_pointer(local->scan_req, req);
765	rcu_assign_pointer(local->scan_sdata, sdata);
766
767	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
768		get_random_mask_addr(local->scan_addr,
769				     req->mac_addr,
770				     req->mac_addr_mask);
771	else
772		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
773
774	if (hw_scan) {
775		__set_bit(SCAN_HW_SCANNING, &local->scanning);
776	} else if ((req->n_channels == 1) &&
777		   (req->channels[0] == local->_oper_chandef.chan)) {
778		/*
779		 * If we are scanning only on the operating channel
780		 * then we do not need to stop normal activities
781		 */
782		unsigned long next_delay;
783
784		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
785
786		ieee80211_recalc_idle(local);
787
788		/* Notify driver scan is starting, keep order of operations
789		 * same as normal software scan, in case that matters. */
790		drv_sw_scan_start(local, sdata, local->scan_addr);
791
792		ieee80211_configure_filter(local); /* accept probe-responses */
793
794		/* We need to ensure power level is at max for scanning. */
795		ieee80211_hw_config(local, 0);
796
797		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
798						IEEE80211_CHAN_RADAR)) ||
799		    !req->n_ssids) {
800			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
801			if (req->n_ssids)
802				set_bit(SCAN_BEACON_WAIT, &local->scanning);
803		} else {
804			ieee80211_scan_state_send_probe(local, &next_delay);
805			next_delay = IEEE80211_CHANNEL_TIME;
806		}
807
808		/* Now, just wait a bit and we are all done! */
809		ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
810					     next_delay);
811		return 0;
812	} else {
813		/* Do normal software scan */
814		__set_bit(SCAN_SW_SCANNING, &local->scanning);
815	}
816
817	ieee80211_recalc_idle(local);
818
819	if (hw_scan) {
820		WARN_ON(!ieee80211_prep_hw_scan(sdata));
821		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
822	} else {
823		rc = ieee80211_start_sw_scan(local, sdata);
824	}
825
826	if (rc) {
827		kfree(local->hw_scan_req);
828		local->hw_scan_req = NULL;
829		local->scanning = 0;
830
831		ieee80211_recalc_idle(local);
832
833		local->scan_req = NULL;
834		RCU_INIT_POINTER(local->scan_sdata, NULL);
835	}
836
837	if (hw_scan && rc == 1) {
838		/*
839		 * we can't fall back to software for P2P-GO
840		 * as it must update NoA etc.
841		 */
842		if (ieee80211_vif_type_p2p(&sdata->vif) ==
843				NL80211_IFTYPE_P2P_GO)
844			return -EOPNOTSUPP;
845		hw_scan = false;
846		goto again;
847	}
848
849	return rc;
850}
851
852static unsigned long
853ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
854{
855	/*
856	 * TODO: channel switching also consumes quite some time,
857	 * add that delay as well to get a better estimation
858	 */
859	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
860		return IEEE80211_PASSIVE_CHANNEL_TIME;
861	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
862}
863
864static void ieee80211_scan_state_decision(struct ieee80211_local *local,
865					  unsigned long *next_delay)
866{
867	bool associated = false;
868	bool tx_empty = true;
869	bool bad_latency;
870	struct ieee80211_sub_if_data *sdata;
871	struct ieee80211_channel *next_chan;
872	enum mac80211_scan_state next_scan_state;
873	struct cfg80211_scan_request *scan_req;
874
875	/*
876	 * check if at least one STA interface is associated,
877	 * check if at least one STA interface has pending tx frames
878	 * and grab the lowest used beacon interval
879	 */
880	mutex_lock(&local->iflist_mtx);
881	list_for_each_entry(sdata, &local->interfaces, list) {
882		if (!ieee80211_sdata_running(sdata))
883			continue;
884
885		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
886			if (sdata->u.mgd.associated) {
887				associated = true;
888
889				if (!qdisc_all_tx_empty(sdata->dev)) {
890					tx_empty = false;
891					break;
892				}
893			}
894		}
895	}
896	mutex_unlock(&local->iflist_mtx);
897
898	scan_req = rcu_dereference_protected(local->scan_req,
899					     lockdep_is_held(&local->mtx));
900
901	next_chan = scan_req->channels[local->scan_channel_idx];
902
903	/*
904	 * we're currently scanning a different channel, let's
905	 * see if we can scan another channel without interfering
906	 * with the current traffic situation.
907	 *
908	 * Keep good latency, do not stay off-channel more than 125 ms.
909	 */
910
911	bad_latency = time_after(jiffies +
912				 ieee80211_scan_get_channel_time(next_chan),
913				 local->leave_oper_channel_time + HZ / 8);
914
915	if (associated && !tx_empty) {
916		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
917			next_scan_state = SCAN_ABORT;
918		else
919			next_scan_state = SCAN_SUSPEND;
920	} else if (associated && bad_latency) {
921		next_scan_state = SCAN_SUSPEND;
922	} else {
923		next_scan_state = SCAN_SET_CHANNEL;
924	}
925
926	local->next_scan_state = next_scan_state;
927
928	*next_delay = 0;
929}
930
931static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
932					     unsigned long *next_delay)
933{
934	int skip;
935	struct ieee80211_channel *chan;
936	enum nl80211_bss_scan_width oper_scan_width;
937	struct cfg80211_scan_request *scan_req;
938
939	scan_req = rcu_dereference_protected(local->scan_req,
940					     lockdep_is_held(&local->mtx));
941
942	skip = 0;
943	chan = scan_req->channels[local->scan_channel_idx];
944
945	local->scan_chandef.chan = chan;
946	local->scan_chandef.center_freq1 = chan->center_freq;
947	local->scan_chandef.freq1_offset = chan->freq_offset;
948	local->scan_chandef.center_freq2 = 0;
949
950	/* For scanning on the S1G band, ignore scan_width (which is constant
951	 * across all channels) for now since channel width is specific to each
952	 * channel. Detect the required channel width here and likely revisit
953	 * later. Maybe scan_width could be used to build the channel scan list?
954	 */
955	if (chan->band == NL80211_BAND_S1GHZ) {
956		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
957		goto set_channel;
958	}
959
960	switch (scan_req->scan_width) {
961	case NL80211_BSS_CHAN_WIDTH_5:
962		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
963		break;
964	case NL80211_BSS_CHAN_WIDTH_10:
965		local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
966		break;
967	default:
968	case NL80211_BSS_CHAN_WIDTH_20:
969		/* If scanning on oper channel, use whatever channel-type
970		 * is currently in use.
971		 */
972		oper_scan_width = cfg80211_chandef_to_scan_width(
973					&local->_oper_chandef);
974		if (chan == local->_oper_chandef.chan &&
975		    oper_scan_width == scan_req->scan_width)
976			local->scan_chandef = local->_oper_chandef;
977		else
978			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
979		break;
980	case NL80211_BSS_CHAN_WIDTH_1:
981	case NL80211_BSS_CHAN_WIDTH_2:
982		/* shouldn't get here, S1G handled above */
983		WARN_ON(1);
984		break;
985	}
986
987set_channel:
988	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
989		skip = 1;
990
991	/* advance state machine to next channel/band */
992	local->scan_channel_idx++;
993
994	if (skip) {
995		/* if we skip this channel return to the decision state */
996		local->next_scan_state = SCAN_DECISION;
997		return;
998	}
999
1000	/*
1001	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1002	 * (which unfortunately doesn't say _why_ step a) is done,
1003	 * but it waits for the probe delay or until a frame is
1004	 * received - and the received frame would update the NAV).
1005	 * For now, we do not support waiting until a frame is
1006	 * received.
1007	 *
1008	 * In any case, it is not necessary for a passive scan.
1009	 */
1010	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1011	    !scan_req->n_ssids) {
1012		*next_delay = 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
1024static 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_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
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
1039static 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
1057void ieee80211_scan_work(struct work_struct *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	mutex_lock(&local->mtx);
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->mtx));
1075	scan_req = rcu_dereference_protected(local->scan_req,
1076					     lockdep_is_held(&local->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		goto out;
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			/* need to complete scan in cfg80211 */
1101			rcu_assign_pointer(local->scan_req, scan_req);
1102			aborted = true;
1103			goto out_complete;
1104		} else
1105			goto out;
1106	}
1107
1108	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1109
1110	/*
1111	 * as long as no delay is required advance immediately
1112	 * without scheduling a new work
1113	 */
1114	do {
1115		if (!ieee80211_sdata_running(sdata)) {
1116			aborted = true;
1117			goto out_complete;
1118		}
1119
1120		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1121		    local->next_scan_state == SCAN_DECISION)
1122			local->next_scan_state = SCAN_SEND_PROBE;
1123
1124		switch (local->next_scan_state) {
1125		case SCAN_DECISION:
1126			/* if no more bands/channels left, complete scan */
1127			if (local->scan_channel_idx >= scan_req->n_channels) {
1128				aborted = false;
1129				goto out_complete;
1130			}
1131			ieee80211_scan_state_decision(local, &next_delay);
1132			break;
1133		case SCAN_SET_CHANNEL:
1134			ieee80211_scan_state_set_channel(local, &next_delay);
1135			break;
1136		case SCAN_SEND_PROBE:
1137			ieee80211_scan_state_send_probe(local, &next_delay);
1138			break;
1139		case SCAN_SUSPEND:
1140			ieee80211_scan_state_suspend(local, &next_delay);
1141			break;
1142		case SCAN_RESUME:
1143			ieee80211_scan_state_resume(local, &next_delay);
1144			break;
1145		case SCAN_ABORT:
1146			aborted = true;
1147			goto out_complete;
1148		}
1149	} while (next_delay == 0);
1150
1151	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1152	goto out;
1153
1154out_complete:
1155	__ieee80211_scan_completed(&local->hw, aborted);
1156out:
1157	mutex_unlock(&local->mtx);
1158}
1159
1160int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1161			   struct cfg80211_scan_request *req)
1162{
1163	int res;
1164
1165	mutex_lock(&sdata->local->mtx);
1166	res = __ieee80211_start_scan(sdata, req);
1167	mutex_unlock(&sdata->local->mtx);
1168
1169	return res;
1170}
1171
1172int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1173				const u8 *ssid, u8 ssid_len,
1174				struct ieee80211_channel **channels,
1175				unsigned int n_channels,
1176				enum nl80211_bss_scan_width scan_width)
1177{
1178	struct ieee80211_local *local = sdata->local;
1179	int ret = -EBUSY, i, n_ch = 0;
1180	enum nl80211_band band;
1181
1182	mutex_lock(&local->mtx);
1183
1184	/* busy scanning */
1185	if (local->scan_req)
1186		goto unlock;
1187
1188	/* fill internal scan request */
1189	if (!channels) {
1190		int max_n;
1191
1192		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1193			if (!local->hw.wiphy->bands[band] ||
1194			    band == NL80211_BAND_6GHZ)
1195				continue;
1196
1197			max_n = local->hw.wiphy->bands[band]->n_channels;
1198			for (i = 0; i < max_n; i++) {
1199				struct ieee80211_channel *tmp_ch =
1200				    &local->hw.wiphy->bands[band]->channels[i];
1201
1202				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1203						     IEEE80211_CHAN_DISABLED))
1204					continue;
1205
1206				local->int_scan_req->channels[n_ch] = tmp_ch;
1207				n_ch++;
1208			}
1209		}
1210
1211		if (WARN_ON_ONCE(n_ch == 0))
1212			goto unlock;
1213
1214		local->int_scan_req->n_channels = n_ch;
1215	} else {
1216		for (i = 0; i < n_channels; i++) {
1217			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1218						  IEEE80211_CHAN_DISABLED))
1219				continue;
1220
1221			local->int_scan_req->channels[n_ch] = channels[i];
1222			n_ch++;
1223		}
1224
1225		if (WARN_ON_ONCE(n_ch == 0))
1226			goto unlock;
1227
1228		local->int_scan_req->n_channels = n_ch;
1229	}
1230
1231	local->int_scan_req->ssids = &local->scan_ssid;
1232	local->int_scan_req->n_ssids = 1;
1233	local->int_scan_req->scan_width = scan_width;
1234	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1235	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1236
1237	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1238 unlock:
1239	mutex_unlock(&local->mtx);
1240	return ret;
1241}
1242
1243/*
1244 * Only call this function when a scan can't be queued -- under RTNL.
1245 */
1246void ieee80211_scan_cancel(struct ieee80211_local *local)
1247{
1248	/*
1249	 * We are canceling software scan, or deferred scan that was not
1250	 * yet really started (see __ieee80211_start_scan ).
1251	 *
1252	 * Regarding hardware scan:
1253	 * - we can not call  __ieee80211_scan_completed() as when
1254	 *   SCAN_HW_SCANNING bit is set this function change
1255	 *   local->hw_scan_req to operate on 5G band, what race with
1256	 *   driver which can use local->hw_scan_req
1257	 *
1258	 * - we can not cancel scan_work since driver can schedule it
1259	 *   by ieee80211_scan_completed(..., true) to finish scan
1260	 *
1261	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1262	 * driver is still responsible for calling ieee80211_scan_completed()
1263	 * after the scan was completed/aborted.
1264	 */
1265
1266	mutex_lock(&local->mtx);
1267	if (!local->scan_req)
1268		goto out;
1269
1270	/*
1271	 * We have a scan running and the driver already reported completion,
1272	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1273	 * cancelled.
1274	 */
1275	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1276	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1277		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1278		goto out;
1279	}
1280
1281	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1282		/*
1283		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1284		 * scan on another band.
1285		 */
1286		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1287		if (local->ops->cancel_hw_scan)
1288			drv_cancel_hw_scan(local,
1289				rcu_dereference_protected(local->scan_sdata,
1290						lockdep_is_held(&local->mtx)));
1291		goto out;
1292	}
1293
1294	/*
1295	 * If the work is currently running, it must be blocked on
1296	 * the mutex, but we'll set scan_sdata = NULL and it'll
1297	 * simply exit once it acquires the mutex.
1298	 */
1299	cancel_delayed_work(&local->scan_work);
1300	/* and clean up */
1301	memset(&local->scan_info, 0, sizeof(local->scan_info));
1302	__ieee80211_scan_completed(&local->hw, true);
1303out:
1304	mutex_unlock(&local->mtx);
1305}
1306
1307int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1308					struct cfg80211_sched_scan_request *req)
1309{
1310	struct ieee80211_local *local = sdata->local;
1311	struct ieee80211_scan_ies sched_scan_ies = {};
1312	struct cfg80211_chan_def chandef;
1313	int ret, i, iebufsz, num_bands = 0;
1314	u32 rate_masks[NUM_NL80211_BANDS] = {};
1315	u8 bands_used = 0;
1316	u8 *ie;
1317	u32 flags = 0;
1318
1319	iebufsz = local->scan_ies_len + req->ie_len;
1320
1321	lockdep_assert_held(&local->mtx);
1322
1323	if (!local->ops->sched_scan_start)
1324		return -ENOTSUPP;
1325
1326	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1327		if (local->hw.wiphy->bands[i]) {
1328			bands_used |= BIT(i);
1329			rate_masks[i] = (u32) -1;
1330			num_bands++;
1331		}
1332	}
1333
1334	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1335		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1336
1337	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1338	if (!ie) {
1339		ret = -ENOMEM;
1340		goto out;
1341	}
1342
1343	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1344
1345	ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1346				 &sched_scan_ies, req->ie,
1347				 req->ie_len, bands_used, rate_masks, &chandef,
1348				 flags);
1349
1350	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1351	if (ret == 0) {
1352		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1353		rcu_assign_pointer(local->sched_scan_req, req);
1354	}
1355
1356	kfree(ie);
1357
1358out:
1359	if (ret) {
1360		/* Clean in case of failure after HW restart or upon resume. */
1361		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1362		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1363	}
1364
1365	return ret;
1366}
1367
1368int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1369				       struct cfg80211_sched_scan_request *req)
1370{
1371	struct ieee80211_local *local = sdata->local;
1372	int ret;
1373
1374	mutex_lock(&local->mtx);
1375
1376	if (rcu_access_pointer(local->sched_scan_sdata)) {
1377		mutex_unlock(&local->mtx);
1378		return -EBUSY;
1379	}
1380
1381	ret = __ieee80211_request_sched_scan_start(sdata, req);
1382
1383	mutex_unlock(&local->mtx);
1384	return ret;
1385}
1386
1387int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1388{
1389	struct ieee80211_sub_if_data *sched_scan_sdata;
1390	int ret = -ENOENT;
1391
1392	mutex_lock(&local->mtx);
1393
1394	if (!local->ops->sched_scan_stop) {
1395		ret = -ENOTSUPP;
1396		goto out;
1397	}
1398
1399	/* We don't want to restart sched scan anymore. */
1400	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1401
1402	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1403						lockdep_is_held(&local->mtx));
1404	if (sched_scan_sdata) {
1405		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1406		if (!ret)
1407			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1408	}
1409out:
1410	mutex_unlock(&local->mtx);
1411
1412	return ret;
1413}
1414
1415void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1416{
1417	struct ieee80211_local *local = hw_to_local(hw);
1418
1419	trace_api_sched_scan_results(local);
1420
1421	cfg80211_sched_scan_results(hw->wiphy, 0);
1422}
1423EXPORT_SYMBOL(ieee80211_sched_scan_results);
1424
1425void ieee80211_sched_scan_end(struct ieee80211_local *local)
1426{
1427	mutex_lock(&local->mtx);
1428
1429	if (!rcu_access_pointer(local->sched_scan_sdata)) {
1430		mutex_unlock(&local->mtx);
1431		return;
1432	}
1433
1434	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1435
1436	/* If sched scan was aborted by the driver. */
1437	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1438
1439	mutex_unlock(&local->mtx);
1440
1441	cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1442}
1443
1444void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1445{
1446	struct ieee80211_local *local =
1447		container_of(work, struct ieee80211_local,
1448			     sched_scan_stopped_work);
1449
1450	ieee80211_sched_scan_end(local);
1451}
1452
1453void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1454{
1455	struct ieee80211_local *local = hw_to_local(hw);
1456
1457	trace_api_sched_scan_stopped(local);
1458
1459	/*
1460	 * this shouldn't really happen, so for simplicity
1461	 * simply ignore it, and let mac80211 reconfigure
1462	 * the sched scan later on.
1463	 */
1464	if (local->in_reconfig)
1465		return;
1466
1467	schedule_work(&local->sched_scan_stopped_work);
1468}
1469EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1470