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.chan = channel;
191
192 rcu_read_lock();
193 scan_sdata = rcu_dereference(local->scan_sdata);
194 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
195 scan_sdata->vif.cfg.assoc &&
196 ieee80211_have_rx_timestamp(rx_status)) {
197 struct ieee80211_bss_conf *link_conf = NULL;
198
199 /* for an MLO connection, set the TSF data only in case we have
200 * an indication on which of the links the frame was received
201 */
202 if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
203 if (rx_status->link_valid) {
204 s8 link_id = rx_status->link_id;
205
206 link_conf =
207 rcu_dereference(scan_sdata->vif.link_conf[link_id]);
208 }
209 } else {
210 link_conf = &scan_sdata->vif.bss_conf;
211 }
212
213 if (link_conf) {
214 bss_meta.parent_tsf =
215 ieee80211_calculate_rx_timestamp(local,
216 rx_status,
217 len + FCS_LEN,
218 24);
219
220 ether_addr_copy(bss_meta.parent_bssid,
221 link_conf->bssid);
222 }
223 }
224 rcu_read_unlock();
225
226 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
227 mgmt, len, GFP_ATOMIC);
228 if (!cbss)
229 return NULL;
230
231 /* In case the signal is invalid update the status */
232 signal_valid = channel == cbss->channel;
233 if (!signal_valid)
234 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
235
236 return (void *)cbss->priv;
237 }
238
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,struct ieee80211_channel * channel,u32 scan_flags,const u8 * da)239 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
240 struct ieee80211_channel *channel,
241 u32 scan_flags, const u8 *da)
242 {
243 if (!sdata)
244 return false;
245
246 /* accept broadcast on 6 GHz and for OCE */
247 if (is_broadcast_ether_addr(da) &&
248 (channel->band == NL80211_BAND_6GHZ ||
249 scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
250 return true;
251
252 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
253 return true;
254 return ether_addr_equal(da, sdata->vif.addr);
255 }
256
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)257 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
258 {
259 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
260 struct ieee80211_mgmt *mgmt = (void *)skb->data;
261 struct ieee80211_bss *bss;
262 struct ieee80211_channel *channel;
263 struct ieee80211_ext *ext;
264 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
265 u.probe_resp.variable);
266
267 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
268 !ieee80211_is_beacon(mgmt->frame_control) &&
269 !ieee80211_is_s1g_beacon(mgmt->frame_control))
270 return;
271
272 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
273 ext = (struct ieee80211_ext *)mgmt;
274 min_hdr_len =
275 offsetof(struct ieee80211_ext, u.s1g_beacon.variable) +
276 ieee80211_s1g_optional_len(ext->frame_control);
277 }
278
279 if (skb->len < min_hdr_len)
280 return;
281
282 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
283 /*
284 * we were passive scanning because of radar/no-IR, but
285 * the beacon/proberesp rx gives us an opportunity to upgrade
286 * to active scan
287 */
288 set_bit(SCAN_BEACON_DONE, &local->scanning);
289 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
290 }
291
292 channel = ieee80211_get_channel_khz(local->hw.wiphy,
293 ieee80211_rx_status_to_khz(rx_status));
294
295 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
296 return;
297
298 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
299 struct ieee80211_sub_if_data *sdata1, *sdata2;
300 struct cfg80211_scan_request *scan_req;
301 struct cfg80211_sched_scan_request *sched_scan_req;
302 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
303
304 sdata1 = rcu_dereference(local->scan_sdata);
305 sdata2 = rcu_dereference(local->sched_scan_sdata);
306
307 if (likely(!sdata1 && !sdata2))
308 return;
309
310 scan_req = rcu_dereference(local->scan_req);
311 sched_scan_req = rcu_dereference(local->sched_scan_req);
312
313 if (scan_req)
314 scan_req_flags = scan_req->flags;
315
316 if (sched_scan_req)
317 sched_scan_req_flags = sched_scan_req->flags;
318
319 /* ignore ProbeResp to foreign address or non-bcast (OCE)
320 * unless scanning with randomised address
321 */
322 if (!ieee80211_scan_accept_presp(sdata1, channel,
323 scan_req_flags,
324 mgmt->da) &&
325 !ieee80211_scan_accept_presp(sdata2, channel,
326 sched_scan_req_flags,
327 mgmt->da))
328 return;
329 } else {
330 /* Beacons are expected only with broadcast address */
331 if (!is_broadcast_ether_addr(mgmt->da))
332 return;
333 }
334
335 /* Do not update the BSS table in case of only monitor interfaces */
336 if (local->open_count == local->monitors)
337 return;
338
339 bss = ieee80211_bss_info_update(local, rx_status,
340 mgmt, skb->len,
341 channel);
342 if (bss)
343 ieee80211_rx_bss_put(local, bss);
344 }
345
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef)346 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
347 {
348 memset(chandef, 0, sizeof(*chandef));
349
350 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
351 }
352
353 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)354 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
355 {
356 struct ieee80211_local *local = sdata->local;
357 struct cfg80211_scan_request *req;
358 struct cfg80211_chan_def chandef;
359 u8 bands_used = 0;
360 int i, ielen;
361 u32 *n_chans;
362 u32 flags = 0;
363
364 req = rcu_dereference_protected(local->scan_req,
365 lockdep_is_held(&local->hw.wiphy->mtx));
366
367 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
368 return false;
369
370 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
371 local->hw_scan_req->req.n_channels = req->n_channels;
372
373 for (i = 0; i < req->n_channels; i++) {
374 local->hw_scan_req->req.channels[i] = req->channels[i];
375 bands_used |= BIT(req->channels[i]->band);
376 }
377 } else {
378 do {
379 if (local->hw_scan_band == NUM_NL80211_BANDS)
380 return false;
381
382 n_chans = &local->hw_scan_req->req.n_channels;
383 *n_chans = 0;
384
385 for (i = 0; i < req->n_channels; i++) {
386 if (req->channels[i]->band !=
387 local->hw_scan_band)
388 continue;
389 local->hw_scan_req->req.channels[(*n_chans)++] =
390 req->channels[i];
391
392 bands_used |= BIT(req->channels[i]->band);
393 }
394
395 local->hw_scan_band++;
396 } while (!*n_chans);
397 }
398
399 ieee80211_prepare_scan_chandef(&chandef);
400
401 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
402 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
403
404 ielen = ieee80211_build_preq_ies(sdata,
405 (u8 *)local->hw_scan_req->req.ie,
406 local->hw_scan_ies_bufsize,
407 &local->hw_scan_req->ies,
408 req->ie, req->ie_len,
409 bands_used, req->rates, &chandef,
410 flags);
411 if (ielen < 0)
412 return false;
413 local->hw_scan_req->req.ie_len = ielen;
414 local->hw_scan_req->req.no_cck = req->no_cck;
415 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
416 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
417 req->mac_addr_mask);
418 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
419
420 return true;
421 }
422
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)423 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
424 {
425 struct ieee80211_local *local = hw_to_local(hw);
426 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
427 bool was_scanning = local->scanning;
428 struct cfg80211_scan_request *scan_req;
429 struct ieee80211_sub_if_data *scan_sdata;
430 struct ieee80211_sub_if_data *sdata;
431
432 lockdep_assert_wiphy(local->hw.wiphy);
433
434 /*
435 * It's ok to abort a not-yet-running scan (that
436 * we have one at all will be verified by checking
437 * local->scan_req next), but not to complete it
438 * successfully.
439 */
440 if (WARN_ON(!local->scanning && !aborted))
441 aborted = true;
442
443 if (WARN_ON(!local->scan_req))
444 return;
445
446 scan_sdata = rcu_dereference_protected(local->scan_sdata,
447 lockdep_is_held(&local->hw.wiphy->mtx));
448
449 if (hw_scan && !aborted &&
450 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
451 ieee80211_prep_hw_scan(scan_sdata)) {
452 int rc;
453
454 rc = drv_hw_scan(local,
455 rcu_dereference_protected(local->scan_sdata,
456 lockdep_is_held(&local->hw.wiphy->mtx)),
457 local->hw_scan_req);
458
459 if (rc == 0)
460 return;
461
462 /* HW scan failed and is going to be reported as aborted,
463 * so clear old scan info.
464 */
465 memset(&local->scan_info, 0, sizeof(local->scan_info));
466 aborted = true;
467 }
468
469 kfree(local->hw_scan_req);
470 local->hw_scan_req = NULL;
471
472 scan_req = rcu_dereference_protected(local->scan_req,
473 lockdep_is_held(&local->hw.wiphy->mtx));
474
475 RCU_INIT_POINTER(local->scan_req, NULL);
476 RCU_INIT_POINTER(local->scan_sdata, NULL);
477
478 local->scanning = 0;
479 local->scan_chandef.chan = NULL;
480
481 synchronize_rcu();
482
483 if (scan_req != local->int_scan_req) {
484 local->scan_info.aborted = aborted;
485 cfg80211_scan_done(scan_req, &local->scan_info);
486 }
487
488 /* Set power back to normal operating levels. */
489 ieee80211_hw_conf_chan(local);
490
491 if (!hw_scan && was_scanning) {
492 ieee80211_configure_filter(local);
493 drv_sw_scan_complete(local, scan_sdata);
494 ieee80211_offchannel_return(local);
495 }
496
497 ieee80211_recalc_idle(local);
498
499 ieee80211_mlme_notify_scan_completed(local);
500 ieee80211_ibss_notify_scan_completed(local);
501
502 /* Requeue all the work that might have been ignored while
503 * the scan was in progress; if there was none this will
504 * just be a no-op for the particular interface.
505 */
506 list_for_each_entry(sdata, &local->interfaces, list) {
507 if (ieee80211_sdata_running(sdata))
508 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
509 }
510
511 if (was_scanning)
512 ieee80211_start_next_roc(local);
513 }
514
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)515 void ieee80211_scan_completed(struct ieee80211_hw *hw,
516 struct cfg80211_scan_info *info)
517 {
518 struct ieee80211_local *local = hw_to_local(hw);
519
520 trace_api_scan_completed(local, info->aborted);
521
522 set_bit(SCAN_COMPLETED, &local->scanning);
523 if (info->aborted)
524 set_bit(SCAN_ABORTED, &local->scanning);
525
526 memcpy(&local->scan_info, info, sizeof(*info));
527
528 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
529 }
530 EXPORT_SYMBOL(ieee80211_scan_completed);
531
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)532 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
533 struct ieee80211_sub_if_data *sdata)
534 {
535 /* Software scan is not supported in multi-channel cases */
536 if (!local->emulate_chanctx)
537 return -EOPNOTSUPP;
538
539 /*
540 * Hardware/driver doesn't support hw_scan, so use software
541 * scanning instead. First send a nullfunc frame with power save
542 * bit on so that AP will buffer the frames for us while we are not
543 * listening, then send probe requests to each channel and wait for
544 * the responses. After all channels are scanned, tune back to the
545 * original channel and send a nullfunc frame with power save bit
546 * off to trigger the AP to send us all the buffered frames.
547 *
548 * Note that while local->sw_scanning is true everything else but
549 * nullfunc frames and probe requests will be dropped in
550 * ieee80211_tx_h_check_assoc().
551 */
552 drv_sw_scan_start(local, sdata, local->scan_addr);
553
554 local->leave_oper_channel_time = jiffies;
555 local->next_scan_state = SCAN_DECISION;
556 local->scan_channel_idx = 0;
557
558 ieee80211_offchannel_stop_vifs(local);
559
560 /* ensure nullfunc is transmitted before leaving operating channel */
561 ieee80211_flush_queues(local, NULL, false);
562
563 ieee80211_configure_filter(local);
564
565 /* We need to set power level at maximum rate for scanning. */
566 ieee80211_hw_conf_chan(local);
567
568 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
569
570 return 0;
571 }
572
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)573 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
574 {
575 struct ieee80211_local *local = sdata->local;
576 struct ieee80211_sub_if_data *sdata_iter;
577 unsigned int link_id;
578
579 lockdep_assert_wiphy(local->hw.wiphy);
580
581 if (!ieee80211_is_radar_required(local))
582 return true;
583
584 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
585 return false;
586
587 list_for_each_entry(sdata_iter, &local->interfaces, list) {
588 for_each_valid_link(&sdata_iter->wdev, link_id)
589 if (sdata_iter->wdev.links[link_id].cac_started)
590 return false;
591 }
592
593 return true;
594 }
595
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)596 static bool ieee80211_can_scan(struct ieee80211_local *local,
597 struct ieee80211_sub_if_data *sdata)
598 {
599 if (!__ieee80211_can_leave_ch(sdata))
600 return false;
601
602 if (!list_empty(&local->roc_list))
603 return false;
604
605 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
606 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
607 return false;
608
609 return true;
610 }
611
ieee80211_run_deferred_scan(struct ieee80211_local * local)612 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
613 {
614 lockdep_assert_wiphy(local->hw.wiphy);
615
616 if (!local->scan_req || local->scanning)
617 return;
618
619 if (!ieee80211_can_scan(local,
620 rcu_dereference_protected(
621 local->scan_sdata,
622 lockdep_is_held(&local->hw.wiphy->mtx))))
623 return;
624
625 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
626 round_jiffies_relative(0));
627 }
628
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)629 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
630 const u8 *src, const u8 *dst,
631 const u8 *ssid, size_t ssid_len,
632 const u8 *ie, size_t ie_len,
633 u32 ratemask, u32 flags, u32 tx_flags,
634 struct ieee80211_channel *channel)
635 {
636 struct sk_buff *skb;
637
638 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
639 ssid, ssid_len,
640 ie, ie_len, flags);
641
642 if (skb) {
643 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
644 struct ieee80211_hdr *hdr = (void *)skb->data;
645 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
646 u16 sn = get_random_u16();
647
648 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
649 hdr->seq_ctrl =
650 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
651 }
652 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
653 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
654 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
655 }
656 }
657
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)658 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
659 unsigned long *next_delay)
660 {
661 int i;
662 struct ieee80211_sub_if_data *sdata;
663 struct cfg80211_scan_request *scan_req;
664 enum nl80211_band band = local->hw.conf.chandef.chan->band;
665 u32 flags = 0, tx_flags;
666
667 scan_req = rcu_dereference_protected(local->scan_req,
668 lockdep_is_held(&local->hw.wiphy->mtx));
669
670 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
671 if (scan_req->no_cck)
672 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
673 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
674 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
675 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
676 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
677
678 sdata = rcu_dereference_protected(local->scan_sdata,
679 lockdep_is_held(&local->hw.wiphy->mtx));
680
681 for (i = 0; i < scan_req->n_ssids; i++)
682 ieee80211_send_scan_probe_req(
683 sdata, local->scan_addr, scan_req->bssid,
684 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
685 scan_req->ie, scan_req->ie_len,
686 scan_req->rates[band], flags,
687 tx_flags, local->hw.conf.chandef.chan);
688
689 /*
690 * After sending probe requests, wait for probe responses
691 * on the channel.
692 */
693 *next_delay = msecs_to_jiffies(scan_req->duration) >
694 IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
695 msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
696 IEEE80211_CHANNEL_TIME;
697 local->next_scan_state = SCAN_DECISION;
698 }
699
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)700 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
701 struct cfg80211_scan_request *req)
702 {
703 struct ieee80211_local *local = sdata->local;
704 bool hw_scan = local->ops->hw_scan;
705 int rc;
706
707 lockdep_assert_wiphy(local->hw.wiphy);
708
709 if (local->scan_req)
710 return -EBUSY;
711
712 /* For an MLO connection, if a link ID was specified, validate that it
713 * is indeed active.
714 */
715 if (ieee80211_vif_is_mld(&sdata->vif) && req->tsf_report_link_id >= 0 &&
716 !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
717 return -EINVAL;
718
719 if (!__ieee80211_can_leave_ch(sdata))
720 return -EBUSY;
721
722 if (!ieee80211_can_scan(local, sdata)) {
723 /* wait for the work to finish/time out */
724 rcu_assign_pointer(local->scan_req, req);
725 rcu_assign_pointer(local->scan_sdata, sdata);
726 return 0;
727 }
728
729 again:
730 if (hw_scan) {
731 u8 *ies;
732
733 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
734
735 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
736 int i, n_bands = 0;
737 u8 bands_counted = 0;
738
739 for (i = 0; i < req->n_channels; i++) {
740 if (bands_counted & BIT(req->channels[i]->band))
741 continue;
742 bands_counted |= BIT(req->channels[i]->band);
743 n_bands++;
744 }
745
746 local->hw_scan_ies_bufsize *= n_bands;
747 }
748
749 local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
750 req.channels,
751 req->n_channels) +
752 local->hw_scan_ies_bufsize,
753 GFP_KERNEL);
754 if (!local->hw_scan_req)
755 return -ENOMEM;
756
757 local->hw_scan_req->req.ssids = req->ssids;
758 local->hw_scan_req->req.n_ssids = req->n_ssids;
759 /* None of the channels are actually set
760 * up but let UBSAN know the boundaries.
761 */
762 local->hw_scan_req->req.n_channels = req->n_channels;
763
764 ies = (u8 *)local->hw_scan_req +
765 sizeof(*local->hw_scan_req) +
766 req->n_channels * sizeof(req->channels[0]);
767 local->hw_scan_req->req.ie = ies;
768 local->hw_scan_req->req.flags = req->flags;
769 eth_broadcast_addr(local->hw_scan_req->req.bssid);
770 local->hw_scan_req->req.duration = req->duration;
771 local->hw_scan_req->req.duration_mandatory =
772 req->duration_mandatory;
773 local->hw_scan_req->req.tsf_report_link_id =
774 req->tsf_report_link_id;
775
776 local->hw_scan_band = 0;
777 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
778 local->hw_scan_req->req.scan_6ghz_params =
779 req->scan_6ghz_params;
780 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
781
782 /*
783 * After allocating local->hw_scan_req, we must
784 * go through until ieee80211_prep_hw_scan(), so
785 * anything that might be changed here and leave
786 * this function early must not go after this
787 * allocation.
788 */
789 }
790
791 rcu_assign_pointer(local->scan_req, req);
792 rcu_assign_pointer(local->scan_sdata, sdata);
793
794 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
795 get_random_mask_addr(local->scan_addr,
796 req->mac_addr,
797 req->mac_addr_mask);
798 else
799 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
800
801 if (hw_scan) {
802 __set_bit(SCAN_HW_SCANNING, &local->scanning);
803 } else if ((req->n_channels == 1) &&
804 (req->channels[0] == local->hw.conf.chandef.chan)) {
805 /*
806 * If we are scanning only on the operating channel
807 * then we do not need to stop normal activities
808 */
809 unsigned long next_delay;
810
811 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
812
813 ieee80211_recalc_idle(local);
814
815 /* Notify driver scan is starting, keep order of operations
816 * same as normal software scan, in case that matters. */
817 drv_sw_scan_start(local, sdata, local->scan_addr);
818
819 ieee80211_configure_filter(local); /* accept probe-responses */
820
821 /* We need to ensure power level is at max for scanning. */
822 ieee80211_hw_conf_chan(local);
823
824 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
825 IEEE80211_CHAN_RADAR)) ||
826 !req->n_ssids) {
827 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
828 if (req->n_ssids)
829 set_bit(SCAN_BEACON_WAIT, &local->scanning);
830 } else {
831 ieee80211_scan_state_send_probe(local, &next_delay);
832 next_delay = IEEE80211_CHANNEL_TIME;
833 }
834
835 /* Now, just wait a bit and we are all done! */
836 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
837 next_delay);
838 return 0;
839 } else {
840 /* Do normal software scan */
841 __set_bit(SCAN_SW_SCANNING, &local->scanning);
842 }
843
844 ieee80211_recalc_idle(local);
845
846 if (hw_scan) {
847 WARN_ON(!ieee80211_prep_hw_scan(sdata));
848 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
849 } else {
850 rc = ieee80211_start_sw_scan(local, sdata);
851 }
852
853 if (rc) {
854 kfree(local->hw_scan_req);
855 local->hw_scan_req = NULL;
856 local->scanning = 0;
857
858 ieee80211_recalc_idle(local);
859
860 local->scan_req = NULL;
861 RCU_INIT_POINTER(local->scan_sdata, NULL);
862 }
863
864 if (hw_scan && rc == 1) {
865 /*
866 * we can't fall back to software for P2P-GO
867 * as it must update NoA etc.
868 */
869 if (ieee80211_vif_type_p2p(&sdata->vif) ==
870 NL80211_IFTYPE_P2P_GO)
871 return -EOPNOTSUPP;
872 hw_scan = false;
873 goto again;
874 }
875
876 return rc;
877 }
878
879 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)880 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
881 {
882 /*
883 * TODO: channel switching also consumes quite some time,
884 * add that delay as well to get a better estimation
885 */
886 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
887 return IEEE80211_PASSIVE_CHANNEL_TIME;
888 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
889 }
890
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)891 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
892 unsigned long *next_delay)
893 {
894 bool associated = false;
895 bool tx_empty = true;
896 bool bad_latency;
897 struct ieee80211_sub_if_data *sdata;
898 struct ieee80211_channel *next_chan;
899 enum mac80211_scan_state next_scan_state;
900 struct cfg80211_scan_request *scan_req;
901
902 lockdep_assert_wiphy(local->hw.wiphy);
903
904 /*
905 * check if at least one STA interface is associated,
906 * check if at least one STA interface has pending tx frames
907 * and grab the lowest used beacon interval
908 */
909 list_for_each_entry(sdata, &local->interfaces, list) {
910 if (!ieee80211_sdata_running(sdata))
911 continue;
912
913 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
914 if (sdata->u.mgd.associated) {
915 associated = true;
916
917 if (!qdisc_all_tx_empty(sdata->dev)) {
918 tx_empty = false;
919 break;
920 }
921 }
922 }
923 }
924
925 scan_req = rcu_dereference_protected(local->scan_req,
926 lockdep_is_held(&local->hw.wiphy->mtx));
927
928 next_chan = scan_req->channels[local->scan_channel_idx];
929
930 /*
931 * we're currently scanning a different channel, let's
932 * see if we can scan another channel without interfering
933 * with the current traffic situation.
934 *
935 * Keep good latency, do not stay off-channel more than 125 ms.
936 */
937
938 bad_latency = time_after(jiffies +
939 ieee80211_scan_get_channel_time(next_chan),
940 local->leave_oper_channel_time + HZ / 8);
941
942 if (associated && !tx_empty) {
943 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
944 next_scan_state = SCAN_ABORT;
945 else
946 next_scan_state = SCAN_SUSPEND;
947 } else if (associated && bad_latency) {
948 next_scan_state = SCAN_SUSPEND;
949 } else {
950 next_scan_state = SCAN_SET_CHANNEL;
951 }
952
953 local->next_scan_state = next_scan_state;
954
955 *next_delay = 0;
956 }
957
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)958 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
959 unsigned long *next_delay)
960 {
961 int skip;
962 struct ieee80211_channel *chan;
963 struct cfg80211_scan_request *scan_req;
964
965 scan_req = rcu_dereference_protected(local->scan_req,
966 lockdep_is_held(&local->hw.wiphy->mtx));
967
968 skip = 0;
969 chan = scan_req->channels[local->scan_channel_idx];
970
971 local->scan_chandef.chan = chan;
972 local->scan_chandef.center_freq1 = chan->center_freq;
973 local->scan_chandef.freq1_offset = chan->freq_offset;
974 local->scan_chandef.center_freq2 = 0;
975
976 /* For scanning on the S1G band, detect the channel width according to
977 * the channel being scanned.
978 */
979 if (chan->band == NL80211_BAND_S1GHZ) {
980 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
981 goto set_channel;
982 }
983
984 /* If scanning on oper channel, use whatever channel-type
985 * is currently in use.
986 */
987 if (chan == local->hw.conf.chandef.chan)
988 local->scan_chandef = local->hw.conf.chandef;
989 else
990 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
991
992 set_channel:
993 if (ieee80211_hw_conf_chan(local))
994 skip = 1;
995
996 /* advance state machine to next channel/band */
997 local->scan_channel_idx++;
998
999 if (skip) {
1000 /* if we skip this channel return to the decision state */
1001 local->next_scan_state = SCAN_DECISION;
1002 return;
1003 }
1004
1005 /*
1006 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1007 * (which unfortunately doesn't say _why_ step a) is done,
1008 * but it waits for the probe delay or until a frame is
1009 * received - and the received frame would update the NAV).
1010 * For now, we do not support waiting until a frame is
1011 * received.
1012 *
1013 * In any case, it is not necessary for a passive scan.
1014 */
1015 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1016 !scan_req->n_ssids) {
1017 *next_delay = max(msecs_to_jiffies(scan_req->duration),
1018 IEEE80211_PASSIVE_CHANNEL_TIME);
1019 local->next_scan_state = SCAN_DECISION;
1020 if (scan_req->n_ssids)
1021 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1022 return;
1023 }
1024
1025 /* active scan, send probes */
1026 *next_delay = IEEE80211_PROBE_DELAY;
1027 local->next_scan_state = SCAN_SEND_PROBE;
1028 }
1029
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1030 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1031 unsigned long *next_delay)
1032 {
1033 /* switch back to the operating channel */
1034 local->scan_chandef.chan = NULL;
1035 ieee80211_hw_conf_chan(local);
1036
1037 /* disable PS */
1038 ieee80211_offchannel_return(local);
1039
1040 *next_delay = HZ / 5;
1041 /* afterwards, resume scan & go to next channel */
1042 local->next_scan_state = SCAN_RESUME;
1043 }
1044
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1045 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1046 unsigned long *next_delay)
1047 {
1048 ieee80211_offchannel_stop_vifs(local);
1049
1050 if (local->ops->flush) {
1051 ieee80211_flush_queues(local, NULL, false);
1052 *next_delay = 0;
1053 } else
1054 *next_delay = HZ / 10;
1055
1056 /* remember when we left the operating channel */
1057 local->leave_oper_channel_time = jiffies;
1058
1059 /* advance to the next channel to be scanned */
1060 local->next_scan_state = SCAN_SET_CHANNEL;
1061 }
1062
ieee80211_scan_work(struct wiphy * wiphy,struct wiphy_work * work)1063 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1064 {
1065 struct ieee80211_local *local =
1066 container_of(work, struct ieee80211_local, scan_work.work);
1067 struct ieee80211_sub_if_data *sdata;
1068 struct cfg80211_scan_request *scan_req;
1069 unsigned long next_delay = 0;
1070 bool aborted;
1071
1072 lockdep_assert_wiphy(local->hw.wiphy);
1073
1074 if (!ieee80211_can_run_worker(local)) {
1075 aborted = true;
1076 goto out_complete;
1077 }
1078
1079 sdata = rcu_dereference_protected(local->scan_sdata,
1080 lockdep_is_held(&local->hw.wiphy->mtx));
1081 scan_req = rcu_dereference_protected(local->scan_req,
1082 lockdep_is_held(&local->hw.wiphy->mtx));
1083
1084 /* When scanning on-channel, the first-callback means completed. */
1085 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1086 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1087 goto out_complete;
1088 }
1089
1090 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1091 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1092 goto out_complete;
1093 }
1094
1095 if (!sdata || !scan_req)
1096 return;
1097
1098 if (!local->scanning) {
1099 int rc;
1100
1101 RCU_INIT_POINTER(local->scan_req, NULL);
1102 RCU_INIT_POINTER(local->scan_sdata, NULL);
1103
1104 rc = __ieee80211_start_scan(sdata, scan_req);
1105 if (!rc)
1106 return;
1107 /* need to complete scan in cfg80211 */
1108 rcu_assign_pointer(local->scan_req, scan_req);
1109 aborted = true;
1110 goto out_complete;
1111 }
1112
1113 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1114
1115 /*
1116 * as long as no delay is required advance immediately
1117 * without scheduling a new work
1118 */
1119 do {
1120 if (!ieee80211_sdata_running(sdata)) {
1121 aborted = true;
1122 goto out_complete;
1123 }
1124
1125 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1126 local->next_scan_state == SCAN_DECISION)
1127 local->next_scan_state = SCAN_SEND_PROBE;
1128
1129 switch (local->next_scan_state) {
1130 case SCAN_DECISION:
1131 /* if no more bands/channels left, complete scan */
1132 if (local->scan_channel_idx >= scan_req->n_channels) {
1133 aborted = false;
1134 goto out_complete;
1135 }
1136 ieee80211_scan_state_decision(local, &next_delay);
1137 break;
1138 case SCAN_SET_CHANNEL:
1139 ieee80211_scan_state_set_channel(local, &next_delay);
1140 break;
1141 case SCAN_SEND_PROBE:
1142 ieee80211_scan_state_send_probe(local, &next_delay);
1143 break;
1144 case SCAN_SUSPEND:
1145 ieee80211_scan_state_suspend(local, &next_delay);
1146 break;
1147 case SCAN_RESUME:
1148 ieee80211_scan_state_resume(local, &next_delay);
1149 break;
1150 case SCAN_ABORT:
1151 aborted = true;
1152 goto out_complete;
1153 }
1154 } while (next_delay == 0);
1155
1156 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1157 next_delay);
1158 return;
1159
1160 out_complete:
1161 __ieee80211_scan_completed(&local->hw, aborted);
1162 }
1163
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1164 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1165 struct cfg80211_scan_request *req)
1166 {
1167 lockdep_assert_wiphy(sdata->local->hw.wiphy);
1168
1169 return __ieee80211_start_scan(sdata, req);
1170 }
1171
ieee80211_request_ibss_scan(struct ieee80211_sub_if_data * sdata,const u8 * ssid,u8 ssid_len,struct ieee80211_channel ** channels,unsigned int n_channels)1172 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1173 const u8 *ssid, u8 ssid_len,
1174 struct ieee80211_channel **channels,
1175 unsigned int n_channels)
1176 {
1177 struct ieee80211_local *local = sdata->local;
1178 int ret = -EBUSY, i, n_ch = 0;
1179 enum nl80211_band band;
1180
1181 lockdep_assert_wiphy(local->hw.wiphy);
1182
1183 /* busy scanning */
1184 if (local->scan_req)
1185 goto unlock;
1186
1187 /* fill internal scan request */
1188 if (!channels) {
1189 int max_n;
1190
1191 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1192 if (!local->hw.wiphy->bands[band] ||
1193 band == NL80211_BAND_6GHZ)
1194 continue;
1195
1196 max_n = local->hw.wiphy->bands[band]->n_channels;
1197 for (i = 0; i < max_n; i++) {
1198 struct ieee80211_channel *tmp_ch =
1199 &local->hw.wiphy->bands[band]->channels[i];
1200
1201 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1202 IEEE80211_CHAN_DISABLED))
1203 continue;
1204
1205 local->int_scan_req->channels[n_ch] = tmp_ch;
1206 n_ch++;
1207 }
1208 }
1209
1210 if (WARN_ON_ONCE(n_ch == 0))
1211 goto unlock;
1212
1213 local->int_scan_req->n_channels = n_ch;
1214 } else {
1215 for (i = 0; i < n_channels; i++) {
1216 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1217 IEEE80211_CHAN_DISABLED))
1218 continue;
1219
1220 local->int_scan_req->channels[n_ch] = channels[i];
1221 n_ch++;
1222 }
1223
1224 if (WARN_ON_ONCE(n_ch == 0))
1225 goto unlock;
1226
1227 local->int_scan_req->n_channels = n_ch;
1228 }
1229
1230 local->int_scan_req->ssids = &local->scan_ssid;
1231 local->int_scan_req->n_ssids = 1;
1232 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1233 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1234
1235 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1236 unlock:
1237 return ret;
1238 }
1239
ieee80211_scan_cancel(struct ieee80211_local * local)1240 void ieee80211_scan_cancel(struct ieee80211_local *local)
1241 {
1242 /* ensure a new scan cannot be queued */
1243 lockdep_assert_wiphy(local->hw.wiphy);
1244
1245 /*
1246 * We are canceling software scan, or deferred scan that was not
1247 * yet really started (see __ieee80211_start_scan ).
1248 *
1249 * Regarding hardware scan:
1250 * - we can not call __ieee80211_scan_completed() as when
1251 * SCAN_HW_SCANNING bit is set this function change
1252 * local->hw_scan_req to operate on 5G band, what race with
1253 * driver which can use local->hw_scan_req
1254 *
1255 * - we can not cancel scan_work since driver can schedule it
1256 * by ieee80211_scan_completed(..., true) to finish scan
1257 *
1258 * Hence we only call the cancel_hw_scan() callback, but the low-level
1259 * driver is still responsible for calling ieee80211_scan_completed()
1260 * after the scan was completed/aborted.
1261 */
1262
1263 if (!local->scan_req)
1264 return;
1265
1266 /*
1267 * We have a scan running and the driver already reported completion,
1268 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1269 * cancelled.
1270 */
1271 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1272 test_bit(SCAN_COMPLETED, &local->scanning)) {
1273 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1274 return;
1275 }
1276
1277 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1278 /*
1279 * Make sure that __ieee80211_scan_completed doesn't trigger a
1280 * scan on another band.
1281 */
1282 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1283 if (local->ops->cancel_hw_scan)
1284 drv_cancel_hw_scan(local,
1285 rcu_dereference_protected(local->scan_sdata,
1286 lockdep_is_held(&local->hw.wiphy->mtx)));
1287 return;
1288 }
1289
1290 wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1291 /* and clean up */
1292 memset(&local->scan_info, 0, sizeof(local->scan_info));
1293 __ieee80211_scan_completed(&local->hw, true);
1294 }
1295
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1296 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1297 struct cfg80211_sched_scan_request *req)
1298 {
1299 struct ieee80211_local *local = sdata->local;
1300 struct ieee80211_scan_ies sched_scan_ies = {};
1301 struct cfg80211_chan_def chandef;
1302 int ret, i, iebufsz, num_bands = 0;
1303 u32 rate_masks[NUM_NL80211_BANDS] = {};
1304 u8 bands_used = 0;
1305 u8 *ie;
1306 u32 flags = 0;
1307
1308 lockdep_assert_wiphy(local->hw.wiphy);
1309
1310 iebufsz = local->scan_ies_len + req->ie_len;
1311
1312 if (!local->ops->sched_scan_start)
1313 return -EOPNOTSUPP;
1314
1315 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1316 if (local->hw.wiphy->bands[i]) {
1317 bands_used |= BIT(i);
1318 rate_masks[i] = (u32) -1;
1319 num_bands++;
1320 }
1321 }
1322
1323 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1324 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1325
1326 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1327 if (!ie) {
1328 ret = -ENOMEM;
1329 goto out;
1330 }
1331
1332 ieee80211_prepare_scan_chandef(&chandef);
1333
1334 ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1335 &sched_scan_ies, req->ie,
1336 req->ie_len, bands_used, rate_masks,
1337 &chandef, flags);
1338 if (ret < 0)
1339 goto error;
1340
1341 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1342 if (ret == 0) {
1343 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1344 rcu_assign_pointer(local->sched_scan_req, req);
1345 }
1346
1347 error:
1348 kfree(ie);
1349 out:
1350 if (ret) {
1351 /* Clean in case of failure after HW restart or upon resume. */
1352 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1353 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1354 }
1355
1356 return ret;
1357 }
1358
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1359 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1360 struct cfg80211_sched_scan_request *req)
1361 {
1362 struct ieee80211_local *local = sdata->local;
1363
1364 lockdep_assert_wiphy(local->hw.wiphy);
1365
1366 if (rcu_access_pointer(local->sched_scan_sdata))
1367 return -EBUSY;
1368
1369 return __ieee80211_request_sched_scan_start(sdata, req);
1370 }
1371
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1372 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1373 {
1374 struct ieee80211_sub_if_data *sched_scan_sdata;
1375 int ret = -ENOENT;
1376
1377 lockdep_assert_wiphy(local->hw.wiphy);
1378
1379 if (!local->ops->sched_scan_stop)
1380 return -EOPNOTSUPP;
1381
1382 /* We don't want to restart sched scan anymore. */
1383 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1384
1385 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1386 lockdep_is_held(&local->hw.wiphy->mtx));
1387 if (sched_scan_sdata) {
1388 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1389 if (!ret)
1390 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1391 }
1392
1393 return ret;
1394 }
1395
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1396 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1397 {
1398 struct ieee80211_local *local = hw_to_local(hw);
1399
1400 trace_api_sched_scan_results(local);
1401
1402 cfg80211_sched_scan_results(hw->wiphy, 0);
1403 }
1404 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1405
ieee80211_sched_scan_end(struct ieee80211_local * local)1406 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1407 {
1408 lockdep_assert_wiphy(local->hw.wiphy);
1409
1410 if (!rcu_access_pointer(local->sched_scan_sdata))
1411 return;
1412
1413 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1414
1415 /* If sched scan was aborted by the driver. */
1416 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1417
1418 cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1419 }
1420
ieee80211_sched_scan_stopped_work(struct wiphy * wiphy,struct wiphy_work * work)1421 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1422 struct wiphy_work *work)
1423 {
1424 struct ieee80211_local *local =
1425 container_of(work, struct ieee80211_local,
1426 sched_scan_stopped_work);
1427
1428 ieee80211_sched_scan_end(local);
1429 }
1430
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1431 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1432 {
1433 struct ieee80211_local *local = hw_to_local(hw);
1434
1435 trace_api_sched_scan_stopped(local);
1436
1437 /*
1438 * this shouldn't really happen, so for simplicity
1439 * simply ignore it, and let mac80211 reconfigure
1440 * the sched scan later on.
1441 */
1442 if (local->in_reconfig)
1443 return;
1444
1445 wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1446 }
1447 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1448