1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Scanning implementation
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2004, Instant802 Networks, Inc.
7  * Copyright 2005, Devicescape Software, Inc.
8  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2013-2015  Intel Mobile Communications GmbH
11  * Copyright 2016-2017  Intel Deutschland GmbH
12  * Copyright (C) 2018-2024 Intel Corporation
13  */
14 
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23 
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27 
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31 
ieee80211_rx_bss_put(struct ieee80211_local * local,struct ieee80211_bss * bss)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 
is_uapsd_supported(struct ieee802_11_elems * elems)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 
ieee80211_inform_bss(struct wiphy * wiphy,struct cfg80211_bss * cbss,const struct cfg80211_bss_ies * ies,void * data)63 void ieee80211_inform_bss(struct wiphy *wiphy,
64 			  struct cfg80211_bss *cbss,
65 			  const struct cfg80211_bss_ies *ies,
66 			  void *data)
67 {
68 	struct ieee80211_local *local = wiphy_priv(wiphy);
69 	struct inform_bss_update_data *update_data = data;
70 	struct ieee80211_bss *bss = (void *)cbss->priv;
71 	struct ieee80211_rx_status *rx_status;
72 	struct ieee802_11_elems *elems;
73 	int clen, srlen;
74 
75 	/* This happens while joining an IBSS */
76 	if (!update_data)
77 		return;
78 
79 	elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
80 	if (!elems)
81 		return;
82 
83 	rx_status = update_data->rx_status;
84 
85 	if (update_data->beacon)
86 		bss->device_ts_beacon = rx_status->device_timestamp;
87 	else
88 		bss->device_ts_presp = rx_status->device_timestamp;
89 
90 	if (elems->parse_error) {
91 		if (update_data->beacon)
92 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
93 		else
94 			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 	} else {
96 		if (update_data->beacon)
97 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
98 		else
99 			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 	}
101 
102 	/* save the ERP value so that it is available at association time */
103 	if (elems->erp_info && (!elems->parse_error ||
104 				!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
105 		bss->erp_value = elems->erp_info[0];
106 		bss->has_erp_value = true;
107 		if (!elems->parse_error)
108 			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 	}
110 
111 	/* replace old supported rates if we get new values */
112 	if (!elems->parse_error ||
113 	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
114 		srlen = 0;
115 		if (elems->supp_rates) {
116 			clen = IEEE80211_MAX_SUPP_RATES;
117 			if (clen > elems->supp_rates_len)
118 				clen = elems->supp_rates_len;
119 			memcpy(bss->supp_rates, elems->supp_rates, clen);
120 			srlen += clen;
121 		}
122 		if (elems->ext_supp_rates) {
123 			clen = IEEE80211_MAX_SUPP_RATES - srlen;
124 			if (clen > elems->ext_supp_rates_len)
125 				clen = elems->ext_supp_rates_len;
126 			memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
127 			       clen);
128 			srlen += clen;
129 		}
130 		if (srlen) {
131 			bss->supp_rates_len = srlen;
132 			if (!elems->parse_error)
133 				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
134 		}
135 	}
136 
137 	if (!elems->parse_error ||
138 	    !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
139 		bss->wmm_used = elems->wmm_param || elems->wmm_info;
140 		bss->uapsd_supported = is_uapsd_supported(elems);
141 		if (!elems->parse_error)
142 			bss->valid_data |= IEEE80211_BSS_VALID_WMM;
143 	}
144 
145 	if (update_data->beacon) {
146 		struct ieee80211_supported_band *sband =
147 			local->hw.wiphy->bands[rx_status->band];
148 		if (!(rx_status->encoding == RX_ENC_HT) &&
149 		    !(rx_status->encoding == RX_ENC_VHT))
150 			bss->beacon_rate =
151 				&sband->bitrates[rx_status->rate_idx];
152 	}
153 
154 	if (elems->vht_cap_elem)
155 		bss->vht_cap_info =
156 			le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
157 	else
158 		bss->vht_cap_info = 0;
159 
160 	kfree(elems);
161 }
162 
163 struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local * local,struct ieee80211_rx_status * rx_status,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_channel * channel)164 ieee80211_bss_info_update(struct ieee80211_local *local,
165 			  struct ieee80211_rx_status *rx_status,
166 			  struct ieee80211_mgmt *mgmt, size_t len,
167 			  struct ieee80211_channel *channel)
168 {
169 	bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
170 		      ieee80211_is_s1g_beacon(mgmt->frame_control);
171 	struct cfg80211_bss *cbss;
172 	struct inform_bss_update_data update_data = {
173 		.rx_status = rx_status,
174 		.beacon = beacon,
175 	};
176 	struct cfg80211_inform_bss bss_meta = {
177 		.boottime_ns = rx_status->boottime_ns,
178 		.drv_data = (void *)&update_data,
179 	};
180 	bool signal_valid;
181 	struct ieee80211_sub_if_data *scan_sdata;
182 
183 	if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
184 		bss_meta.signal = 0; /* invalid signal indication */
185 	else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
186 		bss_meta.signal = rx_status->signal * 100;
187 	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
188 		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
189 
190 	bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
191 	if (rx_status->bw == RATE_INFO_BW_5)
192 		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
193 	else if (rx_status->bw == RATE_INFO_BW_10)
194 		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
195 
196 	bss_meta.chan = channel;
197 
198 	rcu_read_lock();
199 	scan_sdata = rcu_dereference(local->scan_sdata);
200 	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
201 	    scan_sdata->vif.cfg.assoc &&
202 	    ieee80211_have_rx_timestamp(rx_status)) {
203 		bss_meta.parent_tsf =
204 			ieee80211_calculate_rx_timestamp(local, rx_status,
205 							 len + FCS_LEN, 24);
206 		ether_addr_copy(bss_meta.parent_bssid,
207 				scan_sdata->vif.bss_conf.bssid);
208 	}
209 	rcu_read_unlock();
210 
211 	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
212 					      mgmt, len, GFP_ATOMIC);
213 	if (!cbss)
214 		return NULL;
215 
216 	/* In case the signal is invalid update the status */
217 	signal_valid = channel == cbss->channel;
218 	if (!signal_valid)
219 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
220 
221 	return (void *)cbss->priv;
222 }
223 
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,struct ieee80211_channel * channel,u32 scan_flags,const u8 * da)224 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
225 					struct ieee80211_channel *channel,
226 					u32 scan_flags, const u8 *da)
227 {
228 	if (!sdata)
229 		return false;
230 
231 	/* accept broadcast on 6 GHz and for OCE */
232 	if (is_broadcast_ether_addr(da) &&
233 	    (channel->band == NL80211_BAND_6GHZ ||
234 	     scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
235 		return true;
236 
237 	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
238 		return true;
239 	return ether_addr_equal(da, sdata->vif.addr);
240 }
241 
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)242 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
243 {
244 	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
245 	struct ieee80211_sub_if_data *sdata1, *sdata2;
246 	struct ieee80211_mgmt *mgmt = (void *)skb->data;
247 	struct ieee80211_bss *bss;
248 	struct ieee80211_channel *channel;
249 	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
250 				      u.probe_resp.variable);
251 
252 	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
253 	    !ieee80211_is_beacon(mgmt->frame_control) &&
254 	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
255 		return;
256 
257 	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
258 		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
259 			min_hdr_len = offsetof(struct ieee80211_ext,
260 					       u.s1g_short_beacon.variable);
261 		else
262 			min_hdr_len = offsetof(struct ieee80211_ext,
263 					       u.s1g_beacon);
264 	}
265 
266 	if (skb->len < min_hdr_len)
267 		return;
268 
269 	sdata1 = rcu_dereference(local->scan_sdata);
270 	sdata2 = rcu_dereference(local->sched_scan_sdata);
271 
272 	if (likely(!sdata1 && !sdata2))
273 		return;
274 
275 	if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
276 		/*
277 		 * we were passive scanning because of radar/no-IR, but
278 		 * the beacon/proberesp rx gives us an opportunity to upgrade
279 		 * to active scan
280 		 */
281 		set_bit(SCAN_BEACON_DONE, &local->scanning);
282 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
283 	}
284 
285 	channel = ieee80211_get_channel_khz(local->hw.wiphy,
286 					    ieee80211_rx_status_to_khz(rx_status));
287 
288 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
289 		return;
290 
291 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
292 		struct cfg80211_scan_request *scan_req;
293 		struct cfg80211_sched_scan_request *sched_scan_req;
294 		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
295 
296 		scan_req = rcu_dereference(local->scan_req);
297 		sched_scan_req = rcu_dereference(local->sched_scan_req);
298 
299 		if (scan_req)
300 			scan_req_flags = scan_req->flags;
301 
302 		if (sched_scan_req)
303 			sched_scan_req_flags = sched_scan_req->flags;
304 
305 		/* ignore ProbeResp to foreign address or non-bcast (OCE)
306 		 * unless scanning with randomised address
307 		 */
308 		if (!ieee80211_scan_accept_presp(sdata1, channel,
309 						 scan_req_flags,
310 						 mgmt->da) &&
311 		    !ieee80211_scan_accept_presp(sdata2, channel,
312 						 sched_scan_req_flags,
313 						 mgmt->da))
314 			return;
315 	}
316 
317 	bss = ieee80211_bss_info_update(local, rx_status,
318 					mgmt, skb->len,
319 					channel);
320 	if (bss)
321 		ieee80211_rx_bss_put(local, bss);
322 }
323 
324 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)325 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
326 			       enum nl80211_bss_scan_width scan_width)
327 {
328 	memset(chandef, 0, sizeof(*chandef));
329 	switch (scan_width) {
330 	case NL80211_BSS_CHAN_WIDTH_5:
331 		chandef->width = NL80211_CHAN_WIDTH_5;
332 		break;
333 	case NL80211_BSS_CHAN_WIDTH_10:
334 		chandef->width = NL80211_CHAN_WIDTH_10;
335 		break;
336 	default:
337 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
338 		break;
339 	}
340 }
341 
342 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)343 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
344 {
345 	struct ieee80211_local *local = sdata->local;
346 	struct cfg80211_scan_request *req;
347 	struct cfg80211_chan_def chandef;
348 	u8 bands_used = 0;
349 	int i, ielen, n_chans;
350 	u32 flags = 0;
351 
352 	req = rcu_dereference_protected(local->scan_req,
353 					lockdep_is_held(&local->mtx));
354 
355 	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
356 		return false;
357 
358 	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
359 		for (i = 0; i < req->n_channels; i++) {
360 			local->hw_scan_req->req.channels[i] = req->channels[i];
361 			bands_used |= BIT(req->channels[i]->band);
362 		}
363 
364 		n_chans = req->n_channels;
365 	} else {
366 		do {
367 			if (local->hw_scan_band == NUM_NL80211_BANDS)
368 				return false;
369 
370 			n_chans = 0;
371 
372 			for (i = 0; i < req->n_channels; i++) {
373 				if (req->channels[i]->band !=
374 				    local->hw_scan_band)
375 					continue;
376 				local->hw_scan_req->req.channels[n_chans] =
377 							req->channels[i];
378 				n_chans++;
379 				bands_used |= BIT(req->channels[i]->band);
380 			}
381 
382 			local->hw_scan_band++;
383 		} while (!n_chans);
384 	}
385 
386 	local->hw_scan_req->req.n_channels = n_chans;
387 	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
388 
389 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
390 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
391 
392 	ielen = ieee80211_build_preq_ies(sdata,
393 					 (u8 *)local->hw_scan_req->req.ie,
394 					 local->hw_scan_ies_bufsize,
395 					 &local->hw_scan_req->ies,
396 					 req->ie, req->ie_len,
397 					 bands_used, req->rates, &chandef,
398 					 flags);
399 	local->hw_scan_req->req.ie_len = ielen;
400 	local->hw_scan_req->req.no_cck = req->no_cck;
401 	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
402 	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
403 			req->mac_addr_mask);
404 	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
405 
406 	return true;
407 }
408 
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)409 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
410 {
411 	struct ieee80211_local *local = hw_to_local(hw);
412 	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
413 	bool was_scanning = local->scanning;
414 	struct cfg80211_scan_request *scan_req;
415 	struct ieee80211_sub_if_data *scan_sdata;
416 	struct ieee80211_sub_if_data *sdata;
417 
418 	lockdep_assert_held(&local->mtx);
419 
420 	/*
421 	 * It's ok to abort a not-yet-running scan (that
422 	 * we have one at all will be verified by checking
423 	 * local->scan_req next), but not to complete it
424 	 * successfully.
425 	 */
426 	if (WARN_ON(!local->scanning && !aborted))
427 		aborted = true;
428 
429 	if (WARN_ON(!local->scan_req))
430 		return;
431 
432 	scan_sdata = rcu_dereference_protected(local->scan_sdata,
433 					       lockdep_is_held(&local->mtx));
434 
435 	if (hw_scan && !aborted &&
436 	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
437 	    ieee80211_prep_hw_scan(scan_sdata)) {
438 		int rc;
439 
440 		rc = drv_hw_scan(local,
441 			rcu_dereference_protected(local->scan_sdata,
442 						  lockdep_is_held(&local->mtx)),
443 			local->hw_scan_req);
444 
445 		if (rc == 0)
446 			return;
447 
448 		/* HW scan failed and is going to be reported as aborted,
449 		 * so clear old scan info.
450 		 */
451 		memset(&local->scan_info, 0, sizeof(local->scan_info));
452 		aborted = true;
453 	}
454 
455 	kfree(local->hw_scan_req);
456 	local->hw_scan_req = NULL;
457 
458 	scan_req = rcu_dereference_protected(local->scan_req,
459 					     lockdep_is_held(&local->mtx));
460 
461 	RCU_INIT_POINTER(local->scan_req, NULL);
462 	RCU_INIT_POINTER(local->scan_sdata, NULL);
463 
464 	local->scanning = 0;
465 	local->scan_chandef.chan = NULL;
466 
467 	synchronize_rcu();
468 
469 	if (scan_req != local->int_scan_req) {
470 		local->scan_info.aborted = aborted;
471 		cfg80211_scan_done(scan_req, &local->scan_info);
472 	}
473 
474 	/* Set power back to normal operating levels. */
475 	ieee80211_hw_config(local, 0);
476 
477 	if (!hw_scan && was_scanning) {
478 		ieee80211_configure_filter(local);
479 		drv_sw_scan_complete(local, scan_sdata);
480 		ieee80211_offchannel_return(local);
481 	}
482 
483 	ieee80211_recalc_idle(local);
484 
485 	ieee80211_mlme_notify_scan_completed(local);
486 	ieee80211_ibss_notify_scan_completed(local);
487 
488 	/* Requeue all the work that might have been ignored while
489 	 * the scan was in progress; if there was none this will
490 	 * just be a no-op for the particular interface.
491 	 */
492 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
493 		if (ieee80211_sdata_running(sdata))
494 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
495 	}
496 
497 	if (was_scanning)
498 		ieee80211_start_next_roc(local);
499 }
500 
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)501 void ieee80211_scan_completed(struct ieee80211_hw *hw,
502 			      struct cfg80211_scan_info *info)
503 {
504 	struct ieee80211_local *local = hw_to_local(hw);
505 
506 	trace_api_scan_completed(local, info->aborted);
507 
508 	set_bit(SCAN_COMPLETED, &local->scanning);
509 	if (info->aborted)
510 		set_bit(SCAN_ABORTED, &local->scanning);
511 
512 	memcpy(&local->scan_info, info, sizeof(*info));
513 
514 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
515 }
516 EXPORT_SYMBOL(ieee80211_scan_completed);
517 
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)518 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
519 				   struct ieee80211_sub_if_data *sdata)
520 {
521 	/* Software scan is not supported in multi-channel cases */
522 	if (local->use_chanctx)
523 		return -EOPNOTSUPP;
524 
525 	/*
526 	 * Hardware/driver doesn't support hw_scan, so use software
527 	 * scanning instead. First send a nullfunc frame with power save
528 	 * bit on so that AP will buffer the frames for us while we are not
529 	 * listening, then send probe requests to each channel and wait for
530 	 * the responses. After all channels are scanned, tune back to the
531 	 * original channel and send a nullfunc frame with power save bit
532 	 * off to trigger the AP to send us all the buffered frames.
533 	 *
534 	 * Note that while local->sw_scanning is true everything else but
535 	 * nullfunc frames and probe requests will be dropped in
536 	 * ieee80211_tx_h_check_assoc().
537 	 */
538 	drv_sw_scan_start(local, sdata, local->scan_addr);
539 
540 	local->leave_oper_channel_time = jiffies;
541 	local->next_scan_state = SCAN_DECISION;
542 	local->scan_channel_idx = 0;
543 
544 	ieee80211_offchannel_stop_vifs(local);
545 
546 	/* ensure nullfunc is transmitted before leaving operating channel */
547 	ieee80211_flush_queues(local, NULL, false);
548 
549 	ieee80211_configure_filter(local);
550 
551 	/* We need to set power level at maximum rate for scanning. */
552 	ieee80211_hw_config(local, 0);
553 
554 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
555 
556 	return 0;
557 }
558 
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)559 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
560 {
561 	struct ieee80211_local *local = sdata->local;
562 	struct ieee80211_sub_if_data *sdata_iter;
563 
564 	if (!ieee80211_is_radar_required(local))
565 		return true;
566 
567 	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
568 		return false;
569 
570 	mutex_lock(&local->iflist_mtx);
571 	list_for_each_entry(sdata_iter, &local->interfaces, list) {
572 		if (sdata_iter->wdev.cac_started) {
573 			mutex_unlock(&local->iflist_mtx);
574 			return false;
575 		}
576 	}
577 	mutex_unlock(&local->iflist_mtx);
578 
579 	return true;
580 }
581 
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)582 static bool ieee80211_can_scan(struct ieee80211_local *local,
583 			       struct ieee80211_sub_if_data *sdata)
584 {
585 	if (!__ieee80211_can_leave_ch(sdata))
586 		return false;
587 
588 	if (!list_empty(&local->roc_list))
589 		return false;
590 
591 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
592 	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
593 		return false;
594 
595 	return true;
596 }
597 
ieee80211_run_deferred_scan(struct ieee80211_local * local)598 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
599 {
600 	lockdep_assert_held(&local->mtx);
601 
602 	if (!local->scan_req || local->scanning)
603 		return;
604 
605 	if (!ieee80211_can_scan(local,
606 				rcu_dereference_protected(
607 					local->scan_sdata,
608 					lockdep_is_held(&local->mtx))))
609 		return;
610 
611 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
612 				 round_jiffies_relative(0));
613 }
614 
ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data * sdata,const u8 * src,const u8 * dst,const u8 * ssid,size_t ssid_len,const u8 * ie,size_t ie_len,u32 ratemask,u32 flags,u32 tx_flags,struct ieee80211_channel * channel)615 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
616 					  const u8 *src, const u8 *dst,
617 					  const u8 *ssid, size_t ssid_len,
618 					  const u8 *ie, size_t ie_len,
619 					  u32 ratemask, u32 flags, u32 tx_flags,
620 					  struct ieee80211_channel *channel)
621 {
622 	struct sk_buff *skb;
623 
624 	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
625 					ssid, ssid_len,
626 					ie, ie_len, flags);
627 
628 	if (skb) {
629 		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
630 			struct ieee80211_hdr *hdr = (void *)skb->data;
631 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
632 			u16 sn = get_random_u16();
633 
634 			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
635 			hdr->seq_ctrl =
636 				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
637 		}
638 		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
639 		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
640 	}
641 }
642 
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)643 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
644 					    unsigned long *next_delay)
645 {
646 	int i;
647 	struct ieee80211_sub_if_data *sdata;
648 	struct cfg80211_scan_request *scan_req;
649 	enum nl80211_band band = local->hw.conf.chandef.chan->band;
650 	u32 flags = 0, tx_flags;
651 
652 	scan_req = rcu_dereference_protected(local->scan_req,
653 					     lockdep_is_held(&local->mtx));
654 
655 	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
656 	if (scan_req->no_cck)
657 		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
658 	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
659 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
660 	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
661 		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
662 
663 	sdata = rcu_dereference_protected(local->scan_sdata,
664 					  lockdep_is_held(&local->mtx));
665 
666 	for (i = 0; i < scan_req->n_ssids; i++)
667 		ieee80211_send_scan_probe_req(
668 			sdata, local->scan_addr, scan_req->bssid,
669 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
670 			scan_req->ie, scan_req->ie_len,
671 			scan_req->rates[band], flags,
672 			tx_flags, local->hw.conf.chandef.chan);
673 
674 	/*
675 	 * After sending probe requests, wait for probe responses
676 	 * on the channel.
677 	 */
678 	*next_delay = IEEE80211_CHANNEL_TIME;
679 	local->next_scan_state = SCAN_DECISION;
680 }
681 
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)682 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
683 				  struct cfg80211_scan_request *req)
684 {
685 	struct ieee80211_local *local = sdata->local;
686 	bool hw_scan = local->ops->hw_scan;
687 	int rc;
688 
689 	lockdep_assert_held(&local->mtx);
690 
691 	if (local->scan_req)
692 		return -EBUSY;
693 
694 	if (!__ieee80211_can_leave_ch(sdata))
695 		return -EBUSY;
696 
697 	if (!ieee80211_can_scan(local, sdata)) {
698 		/* wait for the work to finish/time out */
699 		rcu_assign_pointer(local->scan_req, req);
700 		rcu_assign_pointer(local->scan_sdata, sdata);
701 		return 0;
702 	}
703 
704  again:
705 	if (hw_scan) {
706 		u8 *ies;
707 
708 		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
709 
710 		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
711 			int i, n_bands = 0;
712 			u8 bands_counted = 0;
713 
714 			for (i = 0; i < req->n_channels; i++) {
715 				if (bands_counted & BIT(req->channels[i]->band))
716 					continue;
717 				bands_counted |= BIT(req->channels[i]->band);
718 				n_bands++;
719 			}
720 
721 			local->hw_scan_ies_bufsize *= n_bands;
722 		}
723 
724 		local->hw_scan_req = kmalloc(
725 				sizeof(*local->hw_scan_req) +
726 				req->n_channels * sizeof(req->channels[0]) +
727 				local->hw_scan_ies_bufsize, GFP_KERNEL);
728 		if (!local->hw_scan_req)
729 			return -ENOMEM;
730 
731 		local->hw_scan_req->req.ssids = req->ssids;
732 		local->hw_scan_req->req.n_ssids = req->n_ssids;
733 		ies = (u8 *)local->hw_scan_req +
734 			sizeof(*local->hw_scan_req) +
735 			req->n_channels * sizeof(req->channels[0]);
736 		local->hw_scan_req->req.ie = ies;
737 		local->hw_scan_req->req.flags = req->flags;
738 		eth_broadcast_addr(local->hw_scan_req->req.bssid);
739 		local->hw_scan_req->req.duration = req->duration;
740 		local->hw_scan_req->req.duration_mandatory =
741 			req->duration_mandatory;
742 
743 		local->hw_scan_band = 0;
744 		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
745 		local->hw_scan_req->req.scan_6ghz_params =
746 			req->scan_6ghz_params;
747 		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
748 
749 		/*
750 		 * After allocating local->hw_scan_req, we must
751 		 * go through until ieee80211_prep_hw_scan(), so
752 		 * anything that might be changed here and leave
753 		 * this function early must not go after this
754 		 * allocation.
755 		 */
756 	}
757 
758 	rcu_assign_pointer(local->scan_req, req);
759 	rcu_assign_pointer(local->scan_sdata, sdata);
760 
761 	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
762 		get_random_mask_addr(local->scan_addr,
763 				     req->mac_addr,
764 				     req->mac_addr_mask);
765 	else
766 		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
767 
768 	if (hw_scan) {
769 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
770 	} else if ((req->n_channels == 1) &&
771 		   (req->channels[0] == local->_oper_chandef.chan)) {
772 		/*
773 		 * If we are scanning only on the operating channel
774 		 * then we do not need to stop normal activities
775 		 */
776 		unsigned long next_delay;
777 
778 		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
779 
780 		ieee80211_recalc_idle(local);
781 
782 		/* Notify driver scan is starting, keep order of operations
783 		 * same as normal software scan, in case that matters. */
784 		drv_sw_scan_start(local, sdata, local->scan_addr);
785 
786 		ieee80211_configure_filter(local); /* accept probe-responses */
787 
788 		/* We need to ensure power level is at max for scanning. */
789 		ieee80211_hw_config(local, 0);
790 
791 		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
792 						IEEE80211_CHAN_RADAR)) ||
793 		    !req->n_ssids) {
794 			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
795 			if (req->n_ssids)
796 				set_bit(SCAN_BEACON_WAIT, &local->scanning);
797 		} else {
798 			ieee80211_scan_state_send_probe(local, &next_delay);
799 			next_delay = IEEE80211_CHANNEL_TIME;
800 		}
801 
802 		/* Now, just wait a bit and we are all done! */
803 		wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
804 					 next_delay);
805 		return 0;
806 	} else {
807 		/* Do normal software scan */
808 		__set_bit(SCAN_SW_SCANNING, &local->scanning);
809 	}
810 
811 	ieee80211_recalc_idle(local);
812 
813 	if (hw_scan) {
814 		WARN_ON(!ieee80211_prep_hw_scan(sdata));
815 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
816 	} else {
817 		rc = ieee80211_start_sw_scan(local, sdata);
818 	}
819 
820 	if (rc) {
821 		kfree(local->hw_scan_req);
822 		local->hw_scan_req = NULL;
823 		local->scanning = 0;
824 
825 		ieee80211_recalc_idle(local);
826 
827 		local->scan_req = NULL;
828 		RCU_INIT_POINTER(local->scan_sdata, NULL);
829 	}
830 
831 	if (hw_scan && rc == 1) {
832 		/*
833 		 * we can't fall back to software for P2P-GO
834 		 * as it must update NoA etc.
835 		 */
836 		if (ieee80211_vif_type_p2p(&sdata->vif) ==
837 				NL80211_IFTYPE_P2P_GO)
838 			return -EOPNOTSUPP;
839 		hw_scan = false;
840 		goto again;
841 	}
842 
843 	return rc;
844 }
845 
846 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)847 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
848 {
849 	/*
850 	 * TODO: channel switching also consumes quite some time,
851 	 * add that delay as well to get a better estimation
852 	 */
853 	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
854 		return IEEE80211_PASSIVE_CHANNEL_TIME;
855 	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
856 }
857 
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)858 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
859 					  unsigned long *next_delay)
860 {
861 	bool associated = false;
862 	bool tx_empty = true;
863 	bool bad_latency;
864 	struct ieee80211_sub_if_data *sdata;
865 	struct ieee80211_channel *next_chan;
866 	enum mac80211_scan_state next_scan_state;
867 	struct cfg80211_scan_request *scan_req;
868 
869 	/*
870 	 * check if at least one STA interface is associated,
871 	 * check if at least one STA interface has pending tx frames
872 	 * and grab the lowest used beacon interval
873 	 */
874 	mutex_lock(&local->iflist_mtx);
875 	list_for_each_entry(sdata, &local->interfaces, list) {
876 		if (!ieee80211_sdata_running(sdata))
877 			continue;
878 
879 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
880 			if (sdata->u.mgd.associated) {
881 				associated = true;
882 
883 				if (!qdisc_all_tx_empty(sdata->dev)) {
884 					tx_empty = false;
885 					break;
886 				}
887 			}
888 		}
889 	}
890 	mutex_unlock(&local->iflist_mtx);
891 
892 	scan_req = rcu_dereference_protected(local->scan_req,
893 					     lockdep_is_held(&local->mtx));
894 
895 	next_chan = scan_req->channels[local->scan_channel_idx];
896 
897 	/*
898 	 * we're currently scanning a different channel, let's
899 	 * see if we can scan another channel without interfering
900 	 * with the current traffic situation.
901 	 *
902 	 * Keep good latency, do not stay off-channel more than 125 ms.
903 	 */
904 
905 	bad_latency = time_after(jiffies +
906 				 ieee80211_scan_get_channel_time(next_chan),
907 				 local->leave_oper_channel_time + HZ / 8);
908 
909 	if (associated && !tx_empty) {
910 		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
911 			next_scan_state = SCAN_ABORT;
912 		else
913 			next_scan_state = SCAN_SUSPEND;
914 	} else if (associated && bad_latency) {
915 		next_scan_state = SCAN_SUSPEND;
916 	} else {
917 		next_scan_state = SCAN_SET_CHANNEL;
918 	}
919 
920 	local->next_scan_state = next_scan_state;
921 
922 	*next_delay = 0;
923 }
924 
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)925 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
926 					     unsigned long *next_delay)
927 {
928 	int skip;
929 	struct ieee80211_channel *chan;
930 	enum nl80211_bss_scan_width oper_scan_width;
931 	struct cfg80211_scan_request *scan_req;
932 
933 	scan_req = rcu_dereference_protected(local->scan_req,
934 					     lockdep_is_held(&local->mtx));
935 
936 	skip = 0;
937 	chan = scan_req->channels[local->scan_channel_idx];
938 
939 	local->scan_chandef.chan = chan;
940 	local->scan_chandef.center_freq1 = chan->center_freq;
941 	local->scan_chandef.freq1_offset = chan->freq_offset;
942 	local->scan_chandef.center_freq2 = 0;
943 
944 	/* For scanning on the S1G band, ignore scan_width (which is constant
945 	 * across all channels) for now since channel width is specific to each
946 	 * channel. Detect the required channel width here and likely revisit
947 	 * later. Maybe scan_width could be used to build the channel scan list?
948 	 */
949 	if (chan->band == NL80211_BAND_S1GHZ) {
950 		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
951 		goto set_channel;
952 	}
953 
954 	switch (scan_req->scan_width) {
955 	case NL80211_BSS_CHAN_WIDTH_5:
956 		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
957 		break;
958 	case NL80211_BSS_CHAN_WIDTH_10:
959 		local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
960 		break;
961 	default:
962 	case NL80211_BSS_CHAN_WIDTH_20:
963 		/* If scanning on oper channel, use whatever channel-type
964 		 * is currently in use.
965 		 */
966 		oper_scan_width = cfg80211_chandef_to_scan_width(
967 					&local->_oper_chandef);
968 		if (chan == local->_oper_chandef.chan &&
969 		    oper_scan_width == scan_req->scan_width)
970 			local->scan_chandef = local->_oper_chandef;
971 		else
972 			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
973 		break;
974 	case NL80211_BSS_CHAN_WIDTH_1:
975 	case NL80211_BSS_CHAN_WIDTH_2:
976 		/* shouldn't get here, S1G handled above */
977 		WARN_ON(1);
978 		break;
979 	}
980 
981 set_channel:
982 	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
983 		skip = 1;
984 
985 	/* advance state machine to next channel/band */
986 	local->scan_channel_idx++;
987 
988 	if (skip) {
989 		/* if we skip this channel return to the decision state */
990 		local->next_scan_state = SCAN_DECISION;
991 		return;
992 	}
993 
994 	/*
995 	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
996 	 * (which unfortunately doesn't say _why_ step a) is done,
997 	 * but it waits for the probe delay or until a frame is
998 	 * received - and the received frame would update the NAV).
999 	 * For now, we do not support waiting until a frame is
1000 	 * received.
1001 	 *
1002 	 * In any case, it is not necessary for a passive scan.
1003 	 */
1004 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1005 	    !scan_req->n_ssids) {
1006 		*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1007 		local->next_scan_state = SCAN_DECISION;
1008 		if (scan_req->n_ssids)
1009 			set_bit(SCAN_BEACON_WAIT, &local->scanning);
1010 		return;
1011 	}
1012 
1013 	/* active scan, send probes */
1014 	*next_delay = IEEE80211_PROBE_DELAY;
1015 	local->next_scan_state = SCAN_SEND_PROBE;
1016 }
1017 
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1018 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1019 					 unsigned long *next_delay)
1020 {
1021 	/* switch back to the operating channel */
1022 	local->scan_chandef.chan = NULL;
1023 	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1024 
1025 	/* disable PS */
1026 	ieee80211_offchannel_return(local);
1027 
1028 	*next_delay = HZ / 5;
1029 	/* afterwards, resume scan & go to next channel */
1030 	local->next_scan_state = SCAN_RESUME;
1031 }
1032 
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1033 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1034 					unsigned long *next_delay)
1035 {
1036 	ieee80211_offchannel_stop_vifs(local);
1037 
1038 	if (local->ops->flush) {
1039 		ieee80211_flush_queues(local, NULL, false);
1040 		*next_delay = 0;
1041 	} else
1042 		*next_delay = HZ / 10;
1043 
1044 	/* remember when we left the operating channel */
1045 	local->leave_oper_channel_time = jiffies;
1046 
1047 	/* advance to the next channel to be scanned */
1048 	local->next_scan_state = SCAN_SET_CHANNEL;
1049 }
1050 
ieee80211_scan_work(struct wiphy * wiphy,struct wiphy_work * work)1051 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1052 {
1053 	struct ieee80211_local *local =
1054 		container_of(work, struct ieee80211_local, scan_work.work);
1055 	struct ieee80211_sub_if_data *sdata;
1056 	struct cfg80211_scan_request *scan_req;
1057 	unsigned long next_delay = 0;
1058 	bool aborted;
1059 
1060 	mutex_lock(&local->mtx);
1061 
1062 	if (!ieee80211_can_run_worker(local)) {
1063 		aborted = true;
1064 		goto out_complete;
1065 	}
1066 
1067 	sdata = rcu_dereference_protected(local->scan_sdata,
1068 					  lockdep_is_held(&local->mtx));
1069 	scan_req = rcu_dereference_protected(local->scan_req,
1070 					     lockdep_is_held(&local->mtx));
1071 
1072 	/* When scanning on-channel, the first-callback means completed. */
1073 	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1074 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1075 		goto out_complete;
1076 	}
1077 
1078 	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1079 		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1080 		goto out_complete;
1081 	}
1082 
1083 	if (!sdata || !scan_req)
1084 		goto out;
1085 
1086 	if (!local->scanning) {
1087 		int rc;
1088 
1089 		RCU_INIT_POINTER(local->scan_req, NULL);
1090 		RCU_INIT_POINTER(local->scan_sdata, NULL);
1091 
1092 		rc = __ieee80211_start_scan(sdata, scan_req);
1093 		if (rc) {
1094 			/* need to complete scan in cfg80211 */
1095 			rcu_assign_pointer(local->scan_req, scan_req);
1096 			aborted = true;
1097 			goto out_complete;
1098 		} else
1099 			goto out;
1100 	}
1101 
1102 	clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1103 
1104 	/*
1105 	 * as long as no delay is required advance immediately
1106 	 * without scheduling a new work
1107 	 */
1108 	do {
1109 		if (!ieee80211_sdata_running(sdata)) {
1110 			aborted = true;
1111 			goto out_complete;
1112 		}
1113 
1114 		if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1115 		    local->next_scan_state == SCAN_DECISION)
1116 			local->next_scan_state = SCAN_SEND_PROBE;
1117 
1118 		switch (local->next_scan_state) {
1119 		case SCAN_DECISION:
1120 			/* if no more bands/channels left, complete scan */
1121 			if (local->scan_channel_idx >= scan_req->n_channels) {
1122 				aborted = false;
1123 				goto out_complete;
1124 			}
1125 			ieee80211_scan_state_decision(local, &next_delay);
1126 			break;
1127 		case SCAN_SET_CHANNEL:
1128 			ieee80211_scan_state_set_channel(local, &next_delay);
1129 			break;
1130 		case SCAN_SEND_PROBE:
1131 			ieee80211_scan_state_send_probe(local, &next_delay);
1132 			break;
1133 		case SCAN_SUSPEND:
1134 			ieee80211_scan_state_suspend(local, &next_delay);
1135 			break;
1136 		case SCAN_RESUME:
1137 			ieee80211_scan_state_resume(local, &next_delay);
1138 			break;
1139 		case SCAN_ABORT:
1140 			aborted = true;
1141 			goto out_complete;
1142 		}
1143 	} while (next_delay == 0);
1144 
1145 	wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1146 				 next_delay);
1147 	goto out;
1148 
1149 out_complete:
1150 	__ieee80211_scan_completed(&local->hw, aborted);
1151 out:
1152 	mutex_unlock(&local->mtx);
1153 }
1154 
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1155 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1156 			   struct cfg80211_scan_request *req)
1157 {
1158 	int res;
1159 
1160 	mutex_lock(&sdata->local->mtx);
1161 	res = __ieee80211_start_scan(sdata, req);
1162 	mutex_unlock(&sdata->local->mtx);
1163 
1164 	return res;
1165 }
1166 
ieee80211_request_ibss_scan(struct ieee80211_sub_if_data * sdata,const u8 * ssid,u8 ssid_len,struct ieee80211_channel ** channels,unsigned int n_channels,enum nl80211_bss_scan_width scan_width)1167 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1168 				const u8 *ssid, u8 ssid_len,
1169 				struct ieee80211_channel **channels,
1170 				unsigned int n_channels,
1171 				enum nl80211_bss_scan_width scan_width)
1172 {
1173 	struct ieee80211_local *local = sdata->local;
1174 	int ret = -EBUSY, i, n_ch = 0;
1175 	enum nl80211_band band;
1176 
1177 	mutex_lock(&local->mtx);
1178 
1179 	/* busy scanning */
1180 	if (local->scan_req)
1181 		goto unlock;
1182 
1183 	/* fill internal scan request */
1184 	if (!channels) {
1185 		int max_n;
1186 
1187 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1188 			if (!local->hw.wiphy->bands[band] ||
1189 			    band == NL80211_BAND_6GHZ)
1190 				continue;
1191 
1192 			max_n = local->hw.wiphy->bands[band]->n_channels;
1193 			for (i = 0; i < max_n; i++) {
1194 				struct ieee80211_channel *tmp_ch =
1195 				    &local->hw.wiphy->bands[band]->channels[i];
1196 
1197 				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1198 						     IEEE80211_CHAN_DISABLED))
1199 					continue;
1200 
1201 				local->int_scan_req->channels[n_ch] = tmp_ch;
1202 				n_ch++;
1203 			}
1204 		}
1205 
1206 		if (WARN_ON_ONCE(n_ch == 0))
1207 			goto unlock;
1208 
1209 		local->int_scan_req->n_channels = n_ch;
1210 	} else {
1211 		for (i = 0; i < n_channels; i++) {
1212 			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1213 						  IEEE80211_CHAN_DISABLED))
1214 				continue;
1215 
1216 			local->int_scan_req->channels[n_ch] = channels[i];
1217 			n_ch++;
1218 		}
1219 
1220 		if (WARN_ON_ONCE(n_ch == 0))
1221 			goto unlock;
1222 
1223 		local->int_scan_req->n_channels = n_ch;
1224 	}
1225 
1226 	local->int_scan_req->ssids = &local->scan_ssid;
1227 	local->int_scan_req->n_ssids = 1;
1228 	local->int_scan_req->scan_width = scan_width;
1229 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1230 	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1231 
1232 	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1233  unlock:
1234 	mutex_unlock(&local->mtx);
1235 	return ret;
1236 }
1237 
ieee80211_scan_cancel(struct ieee80211_local * local)1238 void ieee80211_scan_cancel(struct ieee80211_local *local)
1239 {
1240 	/* ensure a new scan cannot be queued */
1241 	lockdep_assert_wiphy(local->hw.wiphy);
1242 
1243 	/*
1244 	 * We are canceling software scan, or deferred scan that was not
1245 	 * yet really started (see __ieee80211_start_scan ).
1246 	 *
1247 	 * Regarding hardware scan:
1248 	 * - we can not call  __ieee80211_scan_completed() as when
1249 	 *   SCAN_HW_SCANNING bit is set this function change
1250 	 *   local->hw_scan_req to operate on 5G band, what race with
1251 	 *   driver which can use local->hw_scan_req
1252 	 *
1253 	 * - we can not cancel scan_work since driver can schedule it
1254 	 *   by ieee80211_scan_completed(..., true) to finish scan
1255 	 *
1256 	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1257 	 * driver is still responsible for calling ieee80211_scan_completed()
1258 	 * after the scan was completed/aborted.
1259 	 */
1260 
1261 	mutex_lock(&local->mtx);
1262 	if (!local->scan_req)
1263 		goto out;
1264 
1265 	/*
1266 	 * We have a scan running and the driver already reported completion,
1267 	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1268 	 * cancelled.
1269 	 */
1270 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1271 	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1272 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1273 		goto out;
1274 	}
1275 
1276 	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1277 		/*
1278 		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1279 		 * scan on another band.
1280 		 */
1281 		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1282 		if (local->ops->cancel_hw_scan)
1283 			drv_cancel_hw_scan(local,
1284 				rcu_dereference_protected(local->scan_sdata,
1285 						lockdep_is_held(&local->mtx)));
1286 		goto out;
1287 	}
1288 
1289 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1290 	/* and clean up */
1291 	memset(&local->scan_info, 0, sizeof(local->scan_info));
1292 	__ieee80211_scan_completed(&local->hw, true);
1293 out:
1294 	mutex_unlock(&local->mtx);
1295 }
1296 
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1297 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1298 					struct cfg80211_sched_scan_request *req)
1299 {
1300 	struct ieee80211_local *local = sdata->local;
1301 	struct ieee80211_scan_ies sched_scan_ies = {};
1302 	struct cfg80211_chan_def chandef;
1303 	int ret, i, iebufsz, num_bands = 0;
1304 	u32 rate_masks[NUM_NL80211_BANDS] = {};
1305 	u8 bands_used = 0;
1306 	u8 *ie;
1307 	u32 flags = 0;
1308 
1309 	iebufsz = local->scan_ies_len + req->ie_len;
1310 
1311 	lockdep_assert_held(&local->mtx);
1312 
1313 	if (!local->ops->sched_scan_start)
1314 		return -ENOTSUPP;
1315 
1316 	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1317 		if (local->hw.wiphy->bands[i]) {
1318 			bands_used |= BIT(i);
1319 			rate_masks[i] = (u32) -1;
1320 			num_bands++;
1321 		}
1322 	}
1323 
1324 	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1325 		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1326 
1327 	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1328 	if (!ie) {
1329 		ret = -ENOMEM;
1330 		goto out;
1331 	}
1332 
1333 	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1334 
1335 	ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1336 				 &sched_scan_ies, req->ie,
1337 				 req->ie_len, bands_used, rate_masks, &chandef,
1338 				 flags);
1339 
1340 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1341 	if (ret == 0) {
1342 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1343 		rcu_assign_pointer(local->sched_scan_req, req);
1344 	}
1345 
1346 	kfree(ie);
1347 
1348 out:
1349 	if (ret) {
1350 		/* Clean in case of failure after HW restart or upon resume. */
1351 		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1352 		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1353 	}
1354 
1355 	return ret;
1356 }
1357 
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1358 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1359 				       struct cfg80211_sched_scan_request *req)
1360 {
1361 	struct ieee80211_local *local = sdata->local;
1362 	int ret;
1363 
1364 	mutex_lock(&local->mtx);
1365 
1366 	if (rcu_access_pointer(local->sched_scan_sdata)) {
1367 		mutex_unlock(&local->mtx);
1368 		return -EBUSY;
1369 	}
1370 
1371 	ret = __ieee80211_request_sched_scan_start(sdata, req);
1372 
1373 	mutex_unlock(&local->mtx);
1374 	return ret;
1375 }
1376 
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1377 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1378 {
1379 	struct ieee80211_sub_if_data *sched_scan_sdata;
1380 	int ret = -ENOENT;
1381 
1382 	mutex_lock(&local->mtx);
1383 
1384 	if (!local->ops->sched_scan_stop) {
1385 		ret = -ENOTSUPP;
1386 		goto out;
1387 	}
1388 
1389 	/* We don't want to restart sched scan anymore. */
1390 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1391 
1392 	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1393 						lockdep_is_held(&local->mtx));
1394 	if (sched_scan_sdata) {
1395 		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1396 		if (!ret)
1397 			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1398 	}
1399 out:
1400 	mutex_unlock(&local->mtx);
1401 
1402 	return ret;
1403 }
1404 
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1405 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1406 {
1407 	struct ieee80211_local *local = hw_to_local(hw);
1408 
1409 	trace_api_sched_scan_results(local);
1410 
1411 	cfg80211_sched_scan_results(hw->wiphy, 0);
1412 }
1413 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1414 
ieee80211_sched_scan_end(struct ieee80211_local * local)1415 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1416 {
1417 	mutex_lock(&local->mtx);
1418 
1419 	if (!rcu_access_pointer(local->sched_scan_sdata)) {
1420 		mutex_unlock(&local->mtx);
1421 		return;
1422 	}
1423 
1424 	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1425 
1426 	/* If sched scan was aborted by the driver. */
1427 	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1428 
1429 	mutex_unlock(&local->mtx);
1430 
1431 	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1432 }
1433 
ieee80211_sched_scan_stopped_work(struct wiphy * wiphy,struct wiphy_work * work)1434 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1435 				       struct wiphy_work *work)
1436 {
1437 	struct ieee80211_local *local =
1438 		container_of(work, struct ieee80211_local,
1439 			     sched_scan_stopped_work);
1440 
1441 	ieee80211_sched_scan_end(local);
1442 }
1443 
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1444 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1445 {
1446 	struct ieee80211_local *local = hw_to_local(hw);
1447 
1448 	trace_api_sched_scan_stopped(local);
1449 
1450 	/*
1451 	 * this shouldn't really happen, so for simplicity
1452 	 * simply ignore it, and let mac80211 reconfigure
1453 	 * the sched scan later on.
1454 	 */
1455 	if (local->in_reconfig)
1456 		return;
1457 
1458 	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1459 }
1460 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1461