xref: /linux/net/mac80211/scan.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
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) 2018-2025 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,
80 				       update_data->beacon ?
81 					IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON :
82 					IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_PROBE_RESP,
83 				       NULL);
84 	if (!elems)
85 		return;
86 
87 	rx_status = update_data->rx_status;
88 
89 	if (update_data->beacon)
90 		bss->device_ts_beacon = rx_status->device_timestamp;
91 	else
92 		bss->device_ts_presp = rx_status->device_timestamp;
93 
94 	if (elems->parse_error) {
95 		if (update_data->beacon)
96 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
97 		else
98 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
99 	} else {
100 		if (update_data->beacon)
101 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
102 		else
103 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
104 	}
105 
106 	/* save the ERP value so that it is available at association time */
107 	if (elems->erp_info && (!elems->parse_error ||
108 				!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
109 		bss->erp_value = elems->erp_info[0];
110 		bss->has_erp_value = true;
111 		if (!elems->parse_error)
112 			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
113 	}
114 
115 	/* replace old supported rates if we get new values */
116 	if (!elems->parse_error ||
117 	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
118 		srlen = 0;
119 		if (elems->supp_rates) {
120 			clen = IEEE80211_MAX_SUPP_RATES;
121 			if (clen > elems->supp_rates_len)
122 				clen = elems->supp_rates_len;
123 			memcpy(bss->supp_rates, elems->supp_rates, clen);
124 			srlen += clen;
125 		}
126 		if (elems->ext_supp_rates) {
127 			clen = IEEE80211_MAX_SUPP_RATES - srlen;
128 			if (clen > elems->ext_supp_rates_len)
129 				clen = elems->ext_supp_rates_len;
130 			memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
131 			       clen);
132 			srlen += clen;
133 		}
134 		if (srlen) {
135 			bss->supp_rates_len = srlen;
136 			if (!elems->parse_error)
137 				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
138 		}
139 	}
140 
141 	if (!elems->parse_error ||
142 	    !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
143 		bss->wmm_used = elems->wmm_param || elems->wmm_info;
144 		bss->uapsd_supported = is_uapsd_supported(elems);
145 		if (!elems->parse_error)
146 			bss->valid_data |= IEEE80211_BSS_VALID_WMM;
147 	}
148 
149 	if (update_data->beacon) {
150 		struct ieee80211_supported_band *sband =
151 			local->hw.wiphy->bands[rx_status->band];
152 		if (!(rx_status->encoding == RX_ENC_HT) &&
153 		    !(rx_status->encoding == RX_ENC_VHT))
154 			bss->beacon_rate =
155 				&sband->bitrates[rx_status->rate_idx];
156 	}
157 
158 	if (elems->vht_cap_elem)
159 		bss->vht_cap_info =
160 			le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
161 	else
162 		bss->vht_cap_info = 0;
163 
164 	kfree(elems);
165 }
166 
167 struct ieee80211_bss *
168 ieee80211_bss_info_update(struct ieee80211_local *local,
169 			  struct ieee80211_rx_status *rx_status,
170 			  struct ieee80211_mgmt *mgmt, size_t len,
171 			  struct ieee80211_channel *channel)
172 {
173 	bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
174 		      ieee80211_is_s1g_beacon(mgmt->frame_control);
175 	struct cfg80211_bss *cbss;
176 	struct inform_bss_update_data update_data = {
177 		.rx_status = rx_status,
178 		.beacon = beacon,
179 	};
180 	struct cfg80211_inform_bss bss_meta = {
181 		.boottime_ns = rx_status->boottime_ns,
182 		.drv_data = (void *)&update_data,
183 	};
184 	bool signal_valid;
185 	struct ieee80211_sub_if_data *scan_sdata;
186 
187 	if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
188 		bss_meta.signal = 0; /* invalid signal indication */
189 	else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
190 		bss_meta.signal = rx_status->signal * 100;
191 	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
192 		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
193 
194 	bss_meta.chan = channel;
195 
196 	rcu_read_lock();
197 	scan_sdata = rcu_dereference(local->scan_sdata);
198 	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
199 	    scan_sdata->vif.cfg.assoc &&
200 	    ieee80211_have_rx_timestamp(rx_status)) {
201 		struct ieee80211_bss_conf *link_conf = NULL;
202 
203 		/* for an MLO connection, set the TSF data only in case we have
204 		 * an indication on which of the links the frame was received
205 		 */
206 		if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
207 			if (rx_status->link_valid) {
208 				s8 link_id = rx_status->link_id;
209 
210 				link_conf =
211 					rcu_dereference(scan_sdata->vif.link_conf[link_id]);
212 			}
213 		} else {
214 			link_conf = &scan_sdata->vif.bss_conf;
215 		}
216 
217 		if (link_conf) {
218 			bss_meta.parent_tsf =
219 				ieee80211_calculate_rx_timestamp(local,
220 								 rx_status,
221 								 len + FCS_LEN,
222 								 24);
223 
224 			ether_addr_copy(bss_meta.parent_bssid,
225 					link_conf->bssid);
226 		}
227 	}
228 	rcu_read_unlock();
229 
230 	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
231 					      mgmt, len, GFP_ATOMIC);
232 	if (!cbss)
233 		return NULL;
234 
235 	/* In case the signal is invalid update the status */
236 	signal_valid = channel == cbss->channel;
237 	if (!signal_valid)
238 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
239 
240 	return (void *)cbss->priv;
241 }
242 
243 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
244 					struct ieee80211_channel *channel,
245 					u32 scan_flags, const u8 *da)
246 {
247 	struct ieee80211_link_data *link_sdata;
248 	u8 link_id;
249 
250 	if (!sdata)
251 		return false;
252 
253 	/* accept broadcast on 6 GHz and for OCE */
254 	if (is_broadcast_ether_addr(da) &&
255 	    (channel->band == NL80211_BAND_6GHZ ||
256 	     scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
257 		return true;
258 
259 	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
260 		return true;
261 
262 	if (ether_addr_equal(da, sdata->vif.addr))
263 		return true;
264 
265 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
266 		link_sdata = rcu_dereference(sdata->link[link_id]);
267 		if (!link_sdata)
268 			continue;
269 
270 		if (ether_addr_equal(da, link_sdata->conf->addr))
271 			return true;
272 	}
273 
274 	return false;
275 }
276 
277 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
278 {
279 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
280 	struct ieee80211_mgmt *mgmt = (void *)skb->data;
281 	struct ieee80211_bss *bss;
282 	struct ieee80211_channel *channel;
283 	struct ieee80211_ext *ext;
284 	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
285 				      u.probe_resp.variable);
286 
287 	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
288 	    !ieee80211_is_beacon(mgmt->frame_control) &&
289 	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
290 		return;
291 
292 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
293 		ext = (struct ieee80211_ext *)mgmt;
294 		min_hdr_len =
295 			offsetof(struct ieee80211_ext, u.s1g_beacon.variable) +
296 			ieee80211_s1g_optional_len(ext->frame_control);
297 	}
298 
299 	if (skb->len < min_hdr_len)
300 		return;
301 
302 	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
303 		/*
304 		 * we were passive scanning because of radar/no-IR, but
305 		 * the beacon/proberesp rx gives us an opportunity to upgrade
306 		 * to active scan
307 		 */
308 		set_bit(SCAN_BEACON_DONE, &local->scanning);
309 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
310 	}
311 
312 	channel = ieee80211_get_channel_khz(local->hw.wiphy,
313 					    ieee80211_rx_status_to_khz(rx_status));
314 
315 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
316 		return;
317 
318 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
319 		struct ieee80211_sub_if_data *sdata1, *sdata2;
320 		struct cfg80211_scan_request *scan_req;
321 		struct cfg80211_sched_scan_request *sched_scan_req;
322 		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
323 
324 		sdata1 = rcu_dereference(local->scan_sdata);
325 		sdata2 = rcu_dereference(local->sched_scan_sdata);
326 
327 		if (likely(!sdata1 && !sdata2))
328 			return;
329 
330 		scan_req = rcu_dereference(local->scan_req);
331 		sched_scan_req = rcu_dereference(local->sched_scan_req);
332 
333 		if (scan_req)
334 			scan_req_flags = scan_req->flags;
335 
336 		if (sched_scan_req)
337 			sched_scan_req_flags = sched_scan_req->flags;
338 
339 		/* ignore ProbeResp to foreign address or non-bcast (OCE)
340 		 * unless scanning with randomised address
341 		 */
342 		if (!ieee80211_scan_accept_presp(sdata1, channel,
343 						 scan_req_flags,
344 						 mgmt->da) &&
345 		    !ieee80211_scan_accept_presp(sdata2, channel,
346 						 sched_scan_req_flags,
347 						 mgmt->da))
348 			return;
349 	} else {
350 		/* Beacons are expected only with broadcast address */
351 		if (!is_broadcast_ether_addr(mgmt->da))
352 			return;
353 	}
354 
355 	/* Do not update the BSS table in case of only monitor interfaces */
356 	if (local->open_count == local->monitors)
357 		return;
358 
359 	bss = ieee80211_bss_info_update(local, rx_status,
360 					mgmt, skb->len,
361 					channel);
362 	if (bss)
363 		ieee80211_rx_bss_put(local, bss);
364 }
365 
366 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
367 {
368 	memset(chandef, 0, sizeof(*chandef));
369 
370 	chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
371 }
372 
373 /* return false if no more work */
374 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
375 {
376 	struct ieee80211_local *local = sdata->local;
377 	struct cfg80211_scan_request *req;
378 	struct cfg80211_chan_def chandef;
379 	u8 bands_used = 0;
380 	int i, ielen;
381 	u32 *n_chans;
382 	u32 flags = 0;
383 
384 	req = rcu_dereference_protected(local->scan_req,
385 					lockdep_is_held(&local->hw.wiphy->mtx));
386 
387 	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
388 		return false;
389 
390 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
391 		local->hw_scan_req->req.n_channels = req->n_channels;
392 
393 		for (i = 0; i < req->n_channels; i++) {
394 			local->hw_scan_req->req.channels[i] = req->channels[i];
395 			bands_used |= BIT(req->channels[i]->band);
396 		}
397 	} else {
398 		do {
399 			if (local->hw_scan_band == NUM_NL80211_BANDS)
400 				return false;
401 
402 			n_chans = &local->hw_scan_req->req.n_channels;
403 			*n_chans = 0;
404 
405 			for (i = 0; i < req->n_channels; i++) {
406 				if (req->channels[i]->band !=
407 				    local->hw_scan_band)
408 					continue;
409 				local->hw_scan_req->req.channels[(*n_chans)++] =
410 							req->channels[i];
411 
412 				bands_used |= BIT(req->channels[i]->band);
413 			}
414 
415 			local->hw_scan_band++;
416 		} while (!*n_chans);
417 	}
418 
419 	ieee80211_prepare_scan_chandef(&chandef);
420 
421 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
422 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
423 
424 	ielen = ieee80211_build_preq_ies(sdata,
425 					 (u8 *)local->hw_scan_req->req.ie,
426 					 local->hw_scan_ies_bufsize,
427 					 &local->hw_scan_req->ies,
428 					 req->ie, req->ie_len,
429 					 bands_used, req->rates, &chandef,
430 					 flags);
431 	if (ielen < 0)
432 		return false;
433 	local->hw_scan_req->req.ie_len = ielen;
434 	local->hw_scan_req->req.no_cck = req->no_cck;
435 	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
436 	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
437 			req->mac_addr_mask);
438 	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
439 
440 	return true;
441 }
442 
443 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
444 {
445 	struct ieee80211_local *local = hw_to_local(hw);
446 	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
447 	bool was_scanning = local->scanning;
448 	struct cfg80211_scan_request *scan_req;
449 	struct ieee80211_sub_if_data *scan_sdata;
450 	struct ieee80211_sub_if_data *sdata;
451 
452 	lockdep_assert_wiphy(local->hw.wiphy);
453 
454 	/*
455 	 * It's ok to abort a not-yet-running scan (that
456 	 * we have one at all will be verified by checking
457 	 * local->scan_req next), but not to complete it
458 	 * successfully.
459 	 */
460 	if (WARN_ON(!local->scanning && !aborted))
461 		aborted = true;
462 
463 	if (WARN_ON(!local->scan_req))
464 		return;
465 
466 	scan_sdata = rcu_dereference_protected(local->scan_sdata,
467 					       lockdep_is_held(&local->hw.wiphy->mtx));
468 
469 	if (hw_scan && !aborted &&
470 	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
471 	    ieee80211_prep_hw_scan(scan_sdata)) {
472 		int rc;
473 
474 		rc = drv_hw_scan(local,
475 			rcu_dereference_protected(local->scan_sdata,
476 						  lockdep_is_held(&local->hw.wiphy->mtx)),
477 			local->hw_scan_req);
478 
479 		if (rc == 0)
480 			return;
481 
482 		/* HW scan failed and is going to be reported as aborted,
483 		 * so clear old scan info.
484 		 */
485 		memset(&local->scan_info, 0, sizeof(local->scan_info));
486 		aborted = true;
487 	}
488 
489 	kfree(local->hw_scan_req);
490 	local->hw_scan_req = NULL;
491 
492 	scan_req = rcu_dereference_protected(local->scan_req,
493 					     lockdep_is_held(&local->hw.wiphy->mtx));
494 
495 	RCU_INIT_POINTER(local->scan_req, NULL);
496 	RCU_INIT_POINTER(local->scan_sdata, NULL);
497 
498 	local->scanning = 0;
499 	local->scan_chandef.chan = NULL;
500 
501 	synchronize_rcu();
502 
503 	if (scan_req != local->int_scan_req) {
504 		local->scan_info.aborted = aborted;
505 		cfg80211_scan_done(scan_req, &local->scan_info);
506 	}
507 
508 	/* Set power back to normal operating levels. */
509 	ieee80211_hw_conf_chan(local);
510 
511 	if (!hw_scan && was_scanning) {
512 		ieee80211_configure_filter(local);
513 		drv_sw_scan_complete(local, scan_sdata);
514 		ieee80211_offchannel_return(local);
515 	}
516 
517 	ieee80211_recalc_idle(local);
518 
519 	ieee80211_mlme_notify_scan_completed(local);
520 	ieee80211_ibss_notify_scan_completed(local);
521 
522 	/* Requeue all the work that might have been ignored while
523 	 * the scan was in progress; if there was none this will
524 	 * just be a no-op for the particular interface.
525 	 */
526 	list_for_each_entry(sdata, &local->interfaces, list) {
527 		if (ieee80211_sdata_running(sdata))
528 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
529 	}
530 
531 	if (was_scanning)
532 		ieee80211_start_next_roc(local);
533 }
534 
535 void ieee80211_scan_completed(struct ieee80211_hw *hw,
536 			      struct cfg80211_scan_info *info)
537 {
538 	struct ieee80211_local *local = hw_to_local(hw);
539 
540 	trace_api_scan_completed(local, info->aborted);
541 
542 	set_bit(SCAN_COMPLETED, &local->scanning);
543 	if (info->aborted)
544 		set_bit(SCAN_ABORTED, &local->scanning);
545 
546 	memcpy(&local->scan_info, info, sizeof(*info));
547 
548 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
549 }
550 EXPORT_SYMBOL(ieee80211_scan_completed);
551 
552 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
553 				   struct ieee80211_sub_if_data *sdata)
554 {
555 	/* Software scan is not supported in multi-channel cases */
556 	if (!local->emulate_chanctx)
557 		return -EOPNOTSUPP;
558 
559 	/*
560 	 * Hardware/driver doesn't support hw_scan, so use software
561 	 * scanning instead. First send a nullfunc frame with power save
562 	 * bit on so that AP will buffer the frames for us while we are not
563 	 * listening, then send probe requests to each channel and wait for
564 	 * the responses. After all channels are scanned, tune back to the
565 	 * original channel and send a nullfunc frame with power save bit
566 	 * off to trigger the AP to send us all the buffered frames.
567 	 *
568 	 * Note that while local->sw_scanning is true everything else but
569 	 * nullfunc frames and probe requests will be dropped in
570 	 * ieee80211_tx_h_check_assoc().
571 	 */
572 	drv_sw_scan_start(local, sdata, local->scan_addr);
573 
574 	local->leave_oper_channel_time = jiffies;
575 	local->next_scan_state = SCAN_DECISION;
576 	local->scan_channel_idx = 0;
577 
578 	ieee80211_offchannel_stop_vifs(local);
579 
580 	/* ensure nullfunc is transmitted before leaving operating channel */
581 	ieee80211_flush_queues(local, NULL, false);
582 
583 	ieee80211_configure_filter(local);
584 
585 	/* We need to set power level at maximum rate for scanning. */
586 	ieee80211_hw_conf_chan(local);
587 
588 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
589 
590 	return 0;
591 }
592 
593 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata,
594 				     struct cfg80211_scan_request *req)
595 {
596 	struct ieee80211_local *local = sdata->local;
597 	struct ieee80211_sub_if_data *sdata_iter;
598 	unsigned int link_id;
599 
600 	lockdep_assert_wiphy(local->hw.wiphy);
601 
602 	if (!ieee80211_is_radar_required(local, req))
603 		return true;
604 
605 	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
606 		return false;
607 
608 	list_for_each_entry(sdata_iter, &local->interfaces, list) {
609 		for_each_valid_link(&sdata_iter->wdev, link_id)
610 			if (sdata_iter->wdev.links[link_id].cac_started)
611 				return false;
612 	}
613 
614 	return true;
615 }
616 
617 static bool ieee80211_can_scan(struct ieee80211_local *local,
618 			       struct ieee80211_sub_if_data *sdata,
619 			       struct cfg80211_scan_request *req)
620 {
621 	if (!__ieee80211_can_leave_ch(sdata, req))
622 		return false;
623 
624 	if (!list_empty(&local->roc_list))
625 		return false;
626 
627 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
628 	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
629 		return false;
630 
631 	return true;
632 }
633 
634 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
635 {
636 	struct cfg80211_scan_request *req;
637 
638 	lockdep_assert_wiphy(local->hw.wiphy);
639 
640 	if (!local->scan_req || local->scanning)
641 		return;
642 
643 	req = wiphy_dereference(local->hw.wiphy, local->scan_req);
644 	if (!ieee80211_can_scan(local,
645 				rcu_dereference_protected(
646 					local->scan_sdata,
647 					lockdep_is_held(&local->hw.wiphy->mtx)),
648 				req))
649 		return;
650 
651 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
652 				 round_jiffies_relative(0));
653 }
654 
655 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
656 					  const u8 *src, const u8 *dst,
657 					  const u8 *ssid, size_t ssid_len,
658 					  const u8 *ie, size_t ie_len,
659 					  u32 ratemask, u32 flags, u32 tx_flags,
660 					  struct ieee80211_channel *channel)
661 {
662 	struct sk_buff *skb;
663 
664 	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
665 					ssid, ssid_len,
666 					ie, ie_len, flags);
667 
668 	if (skb) {
669 		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
670 			struct ieee80211_hdr *hdr = (void *)skb->data;
671 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
672 			u16 sn = get_random_u16();
673 
674 			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
675 			hdr->seq_ctrl =
676 				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
677 		}
678 		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
679 		IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
680 		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
681 	}
682 }
683 
684 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
685 					    unsigned long *next_delay)
686 {
687 	int i;
688 	struct ieee80211_sub_if_data *sdata;
689 	struct cfg80211_scan_request *scan_req;
690 	enum nl80211_band band = local->hw.conf.chandef.chan->band;
691 	u32 flags = 0, tx_flags;
692 
693 	scan_req = rcu_dereference_protected(local->scan_req,
694 					     lockdep_is_held(&local->hw.wiphy->mtx));
695 
696 	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
697 	if (scan_req->no_cck)
698 		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
699 	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
700 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
701 	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
702 		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
703 
704 	sdata = rcu_dereference_protected(local->scan_sdata,
705 					  lockdep_is_held(&local->hw.wiphy->mtx));
706 
707 	for (i = 0; i < scan_req->n_ssids; i++)
708 		ieee80211_send_scan_probe_req(
709 			sdata, local->scan_addr, scan_req->bssid,
710 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
711 			scan_req->ie, scan_req->ie_len,
712 			scan_req->rates[band], flags,
713 			tx_flags, local->hw.conf.chandef.chan);
714 
715 	/*
716 	 * After sending probe requests, wait for probe responses
717 	 * on the channel.
718 	 */
719 	*next_delay = msecs_to_jiffies(scan_req->duration) >
720 		      IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
721 		      msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
722 		      IEEE80211_CHANNEL_TIME;
723 	local->next_scan_state = SCAN_DECISION;
724 }
725 
726 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
727 				  struct cfg80211_scan_request *req)
728 {
729 	struct ieee80211_local *local = sdata->local;
730 	bool hw_scan = local->ops->hw_scan;
731 	int rc;
732 
733 	lockdep_assert_wiphy(local->hw.wiphy);
734 
735 	if (local->scan_req)
736 		return -EBUSY;
737 
738 	/* For an MLO connection, if a link ID was specified, validate that it
739 	 * is indeed active.
740 	 */
741 	if (ieee80211_vif_is_mld(&sdata->vif) && req->tsf_report_link_id >= 0 &&
742 	    !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
743 		return -EINVAL;
744 
745 	if (!__ieee80211_can_leave_ch(sdata, req))
746 		return -EBUSY;
747 
748 	if (!ieee80211_can_scan(local, sdata, req)) {
749 		/* wait for the work to finish/time out */
750 		rcu_assign_pointer(local->scan_req, req);
751 		rcu_assign_pointer(local->scan_sdata, sdata);
752 		return 0;
753 	}
754 
755  again:
756 	if (hw_scan) {
757 		u8 *ies;
758 
759 		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
760 
761 		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
762 			int i, n_bands = 0;
763 			u8 bands_counted = 0;
764 
765 			for (i = 0; i < req->n_channels; i++) {
766 				if (bands_counted & BIT(req->channels[i]->band))
767 					continue;
768 				bands_counted |= BIT(req->channels[i]->band);
769 				n_bands++;
770 			}
771 
772 			local->hw_scan_ies_bufsize *= n_bands;
773 		}
774 
775 		local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
776 							 req.channels,
777 							 req->n_channels) +
778 					     local->hw_scan_ies_bufsize,
779 					     GFP_KERNEL);
780 		if (!local->hw_scan_req)
781 			return -ENOMEM;
782 
783 		local->hw_scan_req->req.ssids = req->ssids;
784 		local->hw_scan_req->req.n_ssids = req->n_ssids;
785 		/* None of the channels are actually set
786 		 * up but let UBSAN know the boundaries.
787 		 */
788 		local->hw_scan_req->req.n_channels = req->n_channels;
789 
790 		ies = (u8 *)local->hw_scan_req +
791 			sizeof(*local->hw_scan_req) +
792 			req->n_channels * sizeof(req->channels[0]);
793 		local->hw_scan_req->req.ie = ies;
794 		local->hw_scan_req->req.flags = req->flags;
795 		eth_broadcast_addr(local->hw_scan_req->req.bssid);
796 		local->hw_scan_req->req.duration = req->duration;
797 		local->hw_scan_req->req.duration_mandatory =
798 			req->duration_mandatory;
799 		local->hw_scan_req->req.tsf_report_link_id =
800 			req->tsf_report_link_id;
801 
802 		local->hw_scan_band = 0;
803 		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
804 		local->hw_scan_req->req.scan_6ghz_params =
805 			req->scan_6ghz_params;
806 		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
807 		local->hw_scan_req->req.first_part = req->first_part;
808 
809 		/*
810 		 * After allocating local->hw_scan_req, we must
811 		 * go through until ieee80211_prep_hw_scan(), so
812 		 * anything that might be changed here and leave
813 		 * this function early must not go after this
814 		 * allocation.
815 		 */
816 	}
817 
818 	rcu_assign_pointer(local->scan_req, req);
819 	rcu_assign_pointer(local->scan_sdata, sdata);
820 
821 	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
822 		get_random_mask_addr(local->scan_addr,
823 				     req->mac_addr,
824 				     req->mac_addr_mask);
825 	else
826 		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
827 
828 	if (hw_scan) {
829 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
830 	} else if ((req->n_channels == 1) &&
831 		   (req->channels[0] == local->hw.conf.chandef.chan)) {
832 		/*
833 		 * If we are scanning only on the operating channel
834 		 * then we do not need to stop normal activities
835 		 */
836 		unsigned long next_delay;
837 
838 		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
839 
840 		ieee80211_recalc_idle(local);
841 
842 		/* Notify driver scan is starting, keep order of operations
843 		 * same as normal software scan, in case that matters. */
844 		drv_sw_scan_start(local, sdata, local->scan_addr);
845 
846 		ieee80211_configure_filter(local); /* accept probe-responses */
847 
848 		/* We need to ensure power level is at max for scanning. */
849 		ieee80211_hw_conf_chan(local);
850 
851 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
852 						IEEE80211_CHAN_RADAR)) ||
853 		    !req->n_ssids) {
854 			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
855 			if (req->n_ssids)
856 				set_bit(SCAN_BEACON_WAIT, &local->scanning);
857 		} else {
858 			ieee80211_scan_state_send_probe(local, &next_delay);
859 			next_delay = IEEE80211_CHANNEL_TIME;
860 		}
861 
862 		/* Now, just wait a bit and we are all done! */
863 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
864 					 next_delay);
865 		return 0;
866 	} else {
867 		/* Do normal software scan */
868 		__set_bit(SCAN_SW_SCANNING, &local->scanning);
869 	}
870 
871 	ieee80211_recalc_idle(local);
872 
873 	if (hw_scan) {
874 		WARN_ON(!ieee80211_prep_hw_scan(sdata));
875 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
876 	} else {
877 		rc = ieee80211_start_sw_scan(local, sdata);
878 	}
879 
880 	if (rc) {
881 		kfree(local->hw_scan_req);
882 		local->hw_scan_req = NULL;
883 		local->scanning = 0;
884 
885 		ieee80211_recalc_idle(local);
886 
887 		local->scan_req = NULL;
888 		RCU_INIT_POINTER(local->scan_sdata, NULL);
889 	}
890 
891 	if (hw_scan && rc == 1) {
892 		/*
893 		 * we can't fall back to software for P2P-GO
894 		 * as it must update NoA etc.
895 		 */
896 		if (ieee80211_vif_type_p2p(&sdata->vif) ==
897 				NL80211_IFTYPE_P2P_GO)
898 			return -EOPNOTSUPP;
899 		hw_scan = false;
900 		goto again;
901 	}
902 
903 	return rc;
904 }
905 
906 static unsigned long
907 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
908 {
909 	/*
910 	 * TODO: channel switching also consumes quite some time,
911 	 * add that delay as well to get a better estimation
912 	 */
913 	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
914 		return IEEE80211_PASSIVE_CHANNEL_TIME;
915 	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
916 }
917 
918 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
919 					  unsigned long *next_delay)
920 {
921 	bool associated = false;
922 	bool tx_empty = true;
923 	bool bad_latency;
924 	struct ieee80211_sub_if_data *sdata;
925 	struct ieee80211_channel *next_chan;
926 	enum mac80211_scan_state next_scan_state;
927 	struct cfg80211_scan_request *scan_req;
928 
929 	lockdep_assert_wiphy(local->hw.wiphy);
930 
931 	/*
932 	 * check if at least one STA interface is associated,
933 	 * check if at least one STA interface has pending tx frames
934 	 * and grab the lowest used beacon interval
935 	 */
936 	list_for_each_entry(sdata, &local->interfaces, list) {
937 		if (!ieee80211_sdata_running(sdata))
938 			continue;
939 
940 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
941 			if (sdata->u.mgd.associated) {
942 				associated = true;
943 
944 				if (!qdisc_all_tx_empty(sdata->dev)) {
945 					tx_empty = false;
946 					break;
947 				}
948 			}
949 		}
950 	}
951 
952 	scan_req = rcu_dereference_protected(local->scan_req,
953 					     lockdep_is_held(&local->hw.wiphy->mtx));
954 
955 	next_chan = scan_req->channels[local->scan_channel_idx];
956 
957 	/*
958 	 * we're currently scanning a different channel, let's
959 	 * see if we can scan another channel without interfering
960 	 * with the current traffic situation.
961 	 *
962 	 * Keep good latency, do not stay off-channel more than 125 ms.
963 	 */
964 
965 	bad_latency = time_after(jiffies +
966 				 ieee80211_scan_get_channel_time(next_chan),
967 				 local->leave_oper_channel_time + HZ / 8);
968 
969 	if (associated && !tx_empty) {
970 		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
971 			next_scan_state = SCAN_ABORT;
972 		else
973 			next_scan_state = SCAN_SUSPEND;
974 	} else if (associated && bad_latency) {
975 		next_scan_state = SCAN_SUSPEND;
976 	} else {
977 		next_scan_state = SCAN_SET_CHANNEL;
978 	}
979 
980 	local->next_scan_state = next_scan_state;
981 
982 	*next_delay = 0;
983 }
984 
985 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
986 					     unsigned long *next_delay)
987 {
988 	int skip;
989 	struct ieee80211_channel *chan;
990 	struct cfg80211_scan_request *scan_req;
991 
992 	scan_req = rcu_dereference_protected(local->scan_req,
993 					     lockdep_is_held(&local->hw.wiphy->mtx));
994 
995 	skip = 0;
996 	chan = scan_req->channels[local->scan_channel_idx];
997 
998 	local->scan_chandef.chan = chan;
999 	local->scan_chandef.center_freq1 = chan->center_freq;
1000 	local->scan_chandef.freq1_offset = chan->freq_offset;
1001 	local->scan_chandef.center_freq2 = 0;
1002 
1003 	/* For S1G, only scan the 1MHz primaries. */
1004 	if (chan->band == NL80211_BAND_S1GHZ) {
1005 		local->scan_chandef.width = NL80211_CHAN_WIDTH_1;
1006 		local->scan_chandef.s1g_primary_2mhz = false;
1007 		goto set_channel;
1008 	}
1009 
1010 	/*
1011 	 * If scanning on oper channel, use whatever channel-type
1012 	 * is currently in use.
1013 	 */
1014 	if (chan == local->hw.conf.chandef.chan)
1015 		local->scan_chandef = local->hw.conf.chandef;
1016 	else
1017 		local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
1018 
1019 set_channel:
1020 	if (ieee80211_hw_conf_chan(local))
1021 		skip = 1;
1022 
1023 	/* advance state machine to next channel/band */
1024 	local->scan_channel_idx++;
1025 
1026 	if (skip) {
1027 		/* if we skip this channel return to the decision state */
1028 		local->next_scan_state = SCAN_DECISION;
1029 		return;
1030 	}
1031 
1032 	/*
1033 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1034 	 * (which unfortunately doesn't say _why_ step a) is done,
1035 	 * but it waits for the probe delay or until a frame is
1036 	 * received - and the received frame would update the NAV).
1037 	 * For now, we do not support waiting until a frame is
1038 	 * received.
1039 	 *
1040 	 * In any case, it is not necessary for a passive scan.
1041 	 */
1042 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1043 	    !scan_req->n_ssids) {
1044 		*next_delay = max(msecs_to_jiffies(scan_req->duration),
1045 				  IEEE80211_PASSIVE_CHANNEL_TIME);
1046 		local->next_scan_state = SCAN_DECISION;
1047 		if (scan_req->n_ssids)
1048 			set_bit(SCAN_BEACON_WAIT, &local->scanning);
1049 		return;
1050 	}
1051 
1052 	/* active scan, send probes */
1053 	*next_delay = IEEE80211_PROBE_DELAY;
1054 	local->next_scan_state = SCAN_SEND_PROBE;
1055 }
1056 
1057 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1058 					 unsigned long *next_delay)
1059 {
1060 	/* switch back to the operating channel */
1061 	local->scan_chandef.chan = NULL;
1062 	ieee80211_hw_conf_chan(local);
1063 
1064 	/* disable PS */
1065 	ieee80211_offchannel_return(local);
1066 
1067 	*next_delay = HZ / 5;
1068 	/* afterwards, resume scan & go to next channel */
1069 	local->next_scan_state = SCAN_RESUME;
1070 }
1071 
1072 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1073 					unsigned long *next_delay)
1074 {
1075 	ieee80211_offchannel_stop_vifs(local);
1076 
1077 	if (local->ops->flush) {
1078 		ieee80211_flush_queues(local, NULL, false);
1079 		*next_delay = 0;
1080 	} else
1081 		*next_delay = HZ / 10;
1082 
1083 	/* remember when we left the operating channel */
1084 	local->leave_oper_channel_time = jiffies;
1085 
1086 	/* advance to the next channel to be scanned */
1087 	local->next_scan_state = SCAN_SET_CHANNEL;
1088 }
1089 
1090 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1091 {
1092 	struct ieee80211_local *local =
1093 		container_of(work, struct ieee80211_local, scan_work.work);
1094 	struct ieee80211_sub_if_data *sdata;
1095 	struct cfg80211_scan_request *scan_req;
1096 	unsigned long next_delay = 0;
1097 	bool aborted;
1098 
1099 	lockdep_assert_wiphy(local->hw.wiphy);
1100 
1101 	if (!ieee80211_can_run_worker(local)) {
1102 		aborted = true;
1103 		goto out_complete;
1104 	}
1105 
1106 	sdata = rcu_dereference_protected(local->scan_sdata,
1107 					  lockdep_is_held(&local->hw.wiphy->mtx));
1108 	scan_req = rcu_dereference_protected(local->scan_req,
1109 					     lockdep_is_held(&local->hw.wiphy->mtx));
1110 
1111 	/* When scanning on-channel, the first-callback means completed. */
1112 	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1113 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1114 		goto out_complete;
1115 	}
1116 
1117 	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1118 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1119 		goto out_complete;
1120 	}
1121 
1122 	if (!sdata || !scan_req)
1123 		return;
1124 
1125 	if (!local->scanning) {
1126 		int rc;
1127 
1128 		RCU_INIT_POINTER(local->scan_req, NULL);
1129 		RCU_INIT_POINTER(local->scan_sdata, NULL);
1130 
1131 		rc = __ieee80211_start_scan(sdata, scan_req);
1132 		if (!rc)
1133 			return;
1134 		/* need to complete scan in cfg80211 */
1135 		rcu_assign_pointer(local->scan_req, scan_req);
1136 		aborted = true;
1137 		goto out_complete;
1138 	}
1139 
1140 	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1141 
1142 	/*
1143 	 * as long as no delay is required advance immediately
1144 	 * without scheduling a new work
1145 	 */
1146 	do {
1147 		if (!ieee80211_sdata_running(sdata)) {
1148 			aborted = true;
1149 			goto out_complete;
1150 		}
1151 
1152 		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1153 		    local->next_scan_state == SCAN_DECISION)
1154 			local->next_scan_state = SCAN_SEND_PROBE;
1155 
1156 		switch (local->next_scan_state) {
1157 		case SCAN_DECISION:
1158 			/* if no more bands/channels left, complete scan */
1159 			if (local->scan_channel_idx >= scan_req->n_channels) {
1160 				aborted = false;
1161 				goto out_complete;
1162 			}
1163 			ieee80211_scan_state_decision(local, &next_delay);
1164 			break;
1165 		case SCAN_SET_CHANNEL:
1166 			ieee80211_scan_state_set_channel(local, &next_delay);
1167 			break;
1168 		case SCAN_SEND_PROBE:
1169 			ieee80211_scan_state_send_probe(local, &next_delay);
1170 			break;
1171 		case SCAN_SUSPEND:
1172 			ieee80211_scan_state_suspend(local, &next_delay);
1173 			break;
1174 		case SCAN_RESUME:
1175 			ieee80211_scan_state_resume(local, &next_delay);
1176 			break;
1177 		case SCAN_ABORT:
1178 			aborted = true;
1179 			goto out_complete;
1180 		}
1181 	} while (next_delay == 0);
1182 
1183 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1184 				 next_delay);
1185 	return;
1186 
1187 out_complete:
1188 	__ieee80211_scan_completed(&local->hw, aborted);
1189 }
1190 
1191 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1192 			   struct cfg80211_scan_request *req)
1193 {
1194 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1195 
1196 	return __ieee80211_start_scan(sdata, req);
1197 }
1198 
1199 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1200 				const u8 *ssid, u8 ssid_len,
1201 				struct ieee80211_channel **channels,
1202 				unsigned int n_channels)
1203 {
1204 	struct ieee80211_local *local = sdata->local;
1205 	int i, n_ch = 0;
1206 	enum nl80211_band band;
1207 
1208 	lockdep_assert_wiphy(local->hw.wiphy);
1209 
1210 	/* busy scanning */
1211 	if (local->scan_req)
1212 		return -EBUSY;
1213 
1214 	/* fill internal scan request */
1215 	if (!channels) {
1216 		int max_n;
1217 
1218 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1219 			if (!local->hw.wiphy->bands[band] ||
1220 			    band == NL80211_BAND_6GHZ ||
1221 			    band == NL80211_BAND_S1GHZ)
1222 				continue;
1223 
1224 			max_n = local->hw.wiphy->bands[band]->n_channels;
1225 			for (i = 0; i < max_n; i++) {
1226 				struct ieee80211_channel *tmp_ch =
1227 				    &local->hw.wiphy->bands[band]->channels[i];
1228 
1229 				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1230 						     IEEE80211_CHAN_DISABLED) ||
1231 				    !cfg80211_wdev_channel_allowed(&sdata->wdev,
1232 								   tmp_ch))
1233 					continue;
1234 
1235 				local->int_scan_req->channels[n_ch] = tmp_ch;
1236 				n_ch++;
1237 			}
1238 		}
1239 
1240 		if (WARN_ON_ONCE(n_ch == 0))
1241 			return -EINVAL;
1242 
1243 		local->int_scan_req->n_channels = n_ch;
1244 	} else {
1245 		for (i = 0; i < n_channels; i++) {
1246 			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1247 						  IEEE80211_CHAN_DISABLED) ||
1248 			    !cfg80211_wdev_channel_allowed(&sdata->wdev,
1249 							   channels[i]))
1250 				continue;
1251 
1252 			local->int_scan_req->channels[n_ch] = channels[i];
1253 			n_ch++;
1254 		}
1255 
1256 		if (n_ch == 0)
1257 			return -EINVAL;
1258 
1259 		local->int_scan_req->n_channels = n_ch;
1260 	}
1261 
1262 	local->int_scan_req->ssids = &local->scan_ssid;
1263 	local->int_scan_req->n_ssids = 1;
1264 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1265 	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1266 
1267 	return __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1268 }
1269 
1270 void ieee80211_scan_cancel(struct ieee80211_local *local)
1271 {
1272 	/* ensure a new scan cannot be queued */
1273 	lockdep_assert_wiphy(local->hw.wiphy);
1274 
1275 	/*
1276 	 * We are canceling software scan, or deferred scan that was not
1277 	 * yet really started (see __ieee80211_start_scan ).
1278 	 *
1279 	 * Regarding hardware scan:
1280 	 * - we can not call  __ieee80211_scan_completed() as when
1281 	 *   SCAN_HW_SCANNING bit is set this function change
1282 	 *   local->hw_scan_req to operate on 5G band, what race with
1283 	 *   driver which can use local->hw_scan_req
1284 	 *
1285 	 * - we can not cancel scan_work since driver can schedule it
1286 	 *   by ieee80211_scan_completed(..., true) to finish scan
1287 	 *
1288 	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1289 	 * driver is still responsible for calling ieee80211_scan_completed()
1290 	 * after the scan was completed/aborted.
1291 	 */
1292 
1293 	if (!local->scan_req)
1294 		return;
1295 
1296 	/*
1297 	 * We have a scan running and the driver already reported completion,
1298 	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1299 	 * cancelled.
1300 	 */
1301 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1302 	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1303 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1304 		return;
1305 	}
1306 
1307 	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1308 		/*
1309 		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1310 		 * scan on another band.
1311 		 */
1312 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1313 		if (local->ops->cancel_hw_scan)
1314 			drv_cancel_hw_scan(local,
1315 				rcu_dereference_protected(local->scan_sdata,
1316 						lockdep_is_held(&local->hw.wiphy->mtx)));
1317 		return;
1318 	}
1319 
1320 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1321 	/* and clean up */
1322 	memset(&local->scan_info, 0, sizeof(local->scan_info));
1323 	__ieee80211_scan_completed(&local->hw, true);
1324 }
1325 
1326 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1327 					struct cfg80211_sched_scan_request *req)
1328 {
1329 	struct ieee80211_local *local = sdata->local;
1330 	struct ieee80211_scan_ies sched_scan_ies = {};
1331 	struct cfg80211_chan_def chandef;
1332 	int ret, i, iebufsz, num_bands = 0;
1333 	u32 rate_masks[NUM_NL80211_BANDS] = {};
1334 	u8 bands_used = 0;
1335 	u8 *ie;
1336 	u32 flags = 0;
1337 
1338 	lockdep_assert_wiphy(local->hw.wiphy);
1339 
1340 	iebufsz = local->scan_ies_len + req->ie_len;
1341 
1342 	if (!local->ops->sched_scan_start)
1343 		return -EOPNOTSUPP;
1344 
1345 	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1346 		if (local->hw.wiphy->bands[i]) {
1347 			bands_used |= BIT(i);
1348 			rate_masks[i] = (u32) -1;
1349 			num_bands++;
1350 		}
1351 	}
1352 
1353 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1354 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1355 
1356 	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1357 	if (!ie) {
1358 		ret = -ENOMEM;
1359 		goto out;
1360 	}
1361 
1362 	ieee80211_prepare_scan_chandef(&chandef);
1363 
1364 	ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1365 				       &sched_scan_ies, req->ie,
1366 				       req->ie_len, bands_used, rate_masks,
1367 				       &chandef, flags);
1368 	if (ret < 0)
1369 		goto error;
1370 
1371 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1372 	if (ret == 0) {
1373 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1374 		rcu_assign_pointer(local->sched_scan_req, req);
1375 	}
1376 
1377 error:
1378 	kfree(ie);
1379 out:
1380 	if (ret) {
1381 		/* Clean in case of failure after HW restart or upon resume. */
1382 		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1383 		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1384 	}
1385 
1386 	return ret;
1387 }
1388 
1389 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1390 				       struct cfg80211_sched_scan_request *req)
1391 {
1392 	struct ieee80211_local *local = sdata->local;
1393 
1394 	lockdep_assert_wiphy(local->hw.wiphy);
1395 
1396 	if (rcu_access_pointer(local->sched_scan_sdata))
1397 		return -EBUSY;
1398 
1399 	return __ieee80211_request_sched_scan_start(sdata, req);
1400 }
1401 
1402 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1403 {
1404 	struct ieee80211_sub_if_data *sched_scan_sdata;
1405 	int ret = -ENOENT;
1406 
1407 	lockdep_assert_wiphy(local->hw.wiphy);
1408 
1409 	if (!local->ops->sched_scan_stop)
1410 		return -EOPNOTSUPP;
1411 
1412 	/* We don't want to restart sched scan anymore. */
1413 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1414 
1415 	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1416 						lockdep_is_held(&local->hw.wiphy->mtx));
1417 	if (sched_scan_sdata) {
1418 		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1419 		if (!ret)
1420 			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1421 	}
1422 
1423 	return ret;
1424 }
1425 
1426 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1427 {
1428 	struct ieee80211_local *local = hw_to_local(hw);
1429 
1430 	trace_api_sched_scan_results(local);
1431 
1432 	cfg80211_sched_scan_results(hw->wiphy, 0);
1433 }
1434 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1435 
1436 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1437 {
1438 	lockdep_assert_wiphy(local->hw.wiphy);
1439 
1440 	if (!rcu_access_pointer(local->sched_scan_sdata))
1441 		return;
1442 
1443 	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1444 
1445 	/* If sched scan was aborted by the driver. */
1446 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1447 
1448 	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1449 }
1450 
1451 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1452 				       struct wiphy_work *work)
1453 {
1454 	struct ieee80211_local *local =
1455 		container_of(work, struct ieee80211_local,
1456 			     sched_scan_stopped_work);
1457 
1458 	ieee80211_sched_scan_end(local);
1459 }
1460 
1461 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1462 {
1463 	struct ieee80211_local *local = hw_to_local(hw);
1464 
1465 	trace_api_sched_scan_stopped(local);
1466 
1467 	/*
1468 	 * this shouldn't really happen, so for simplicity
1469 	 * simply ignore it, and let mac80211 reconfigure
1470 	 * the sched scan later on.
1471 	 */
1472 	if (local->in_reconfig)
1473 		return;
1474 
1475 	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1476 }
1477 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1478