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