Merge tag 'socfpga_dts_updates_for_v5.5_part2' of git://git.kernel.org/pub/scm/linux...
[linux-2.6-microblaze.git] / net / mac80211 / scan.c
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) 2018-2019 Intel Corporation
13  */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33                           struct ieee80211_bss *bss)
34 {
35         if (!bss)
36                 return;
37         cfg80211_put_bss(local->hw.wiphy,
38                          container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40
41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43         u8 qos_info;
44
45         if (elems->wmm_info && elems->wmm_info_len == 7
46             && elems->wmm_info[5] == 1)
47                 qos_info = elems->wmm_info[6];
48         else if (elems->wmm_param && elems->wmm_param_len == 24
49                  && elems->wmm_param[5] == 1)
50                 qos_info = elems->wmm_param[6];
51         else
52                 /* no valid wmm information or parameter element found */
53                 return false;
54
55         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57
58 static void
59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60                                 struct ieee80211_bss *bss,
61                                 struct ieee802_11_elems *elems,
62                                 struct ieee80211_rx_status *rx_status,
63                                 bool beacon)
64 {
65         int clen, srlen;
66
67         if (beacon)
68                 bss->device_ts_beacon = rx_status->device_timestamp;
69         else
70                 bss->device_ts_presp = rx_status->device_timestamp;
71
72         if (elems->parse_error) {
73                 if (beacon)
74                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75                 else
76                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77         } else {
78                 if (beacon)
79                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80                 else
81                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82         }
83
84         /* save the ERP value so that it is available at association time */
85         if (elems->erp_info && (!elems->parse_error ||
86                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87                 bss->erp_value = elems->erp_info[0];
88                 bss->has_erp_value = true;
89                 if (!elems->parse_error)
90                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91         }
92
93         /* replace old supported rates if we get new values */
94         if (!elems->parse_error ||
95             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96                 srlen = 0;
97                 if (elems->supp_rates) {
98                         clen = IEEE80211_MAX_SUPP_RATES;
99                         if (clen > elems->supp_rates_len)
100                                 clen = elems->supp_rates_len;
101                         memcpy(bss->supp_rates, elems->supp_rates, clen);
102                         srlen += clen;
103                 }
104                 if (elems->ext_supp_rates) {
105                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
106                         if (clen > elems->ext_supp_rates_len)
107                                 clen = elems->ext_supp_rates_len;
108                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109                                clen);
110                         srlen += clen;
111                 }
112                 if (srlen) {
113                         bss->supp_rates_len = srlen;
114                         if (!elems->parse_error)
115                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116                 }
117         }
118
119         if (!elems->parse_error ||
120             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122                 bss->uapsd_supported = is_uapsd_supported(elems);
123                 if (!elems->parse_error)
124                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125         }
126
127         if (beacon) {
128                 struct ieee80211_supported_band *sband =
129                         local->hw.wiphy->bands[rx_status->band];
130                 if (!(rx_status->encoding == RX_ENC_HT) &&
131                     !(rx_status->encoding == RX_ENC_VHT))
132                         bss->beacon_rate =
133                                 &sband->bitrates[rx_status->rate_idx];
134         }
135 }
136
137 struct ieee80211_bss *
138 ieee80211_bss_info_update(struct ieee80211_local *local,
139                           struct ieee80211_rx_status *rx_status,
140                           struct ieee80211_mgmt *mgmt, size_t len,
141                           struct ieee80211_channel *channel)
142 {
143         bool beacon = ieee80211_is_beacon(mgmt->frame_control);
144         struct cfg80211_bss *cbss, *non_tx_cbss;
145         struct ieee80211_bss *bss, *non_tx_bss;
146         struct cfg80211_inform_bss bss_meta = {
147                 .boottime_ns = rx_status->boottime_ns,
148         };
149         bool signal_valid;
150         struct ieee80211_sub_if_data *scan_sdata;
151         struct ieee802_11_elems elems;
152         size_t baselen;
153         u8 *elements;
154
155         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
156                 bss_meta.signal = 0; /* invalid signal indication */
157         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
158                 bss_meta.signal = rx_status->signal * 100;
159         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
160                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
161
162         bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
163         if (rx_status->bw == RATE_INFO_BW_5)
164                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
165         else if (rx_status->bw == RATE_INFO_BW_10)
166                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
167
168         bss_meta.chan = channel;
169
170         rcu_read_lock();
171         scan_sdata = rcu_dereference(local->scan_sdata);
172         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
173             scan_sdata->vif.bss_conf.assoc &&
174             ieee80211_have_rx_timestamp(rx_status)) {
175                 bss_meta.parent_tsf =
176                         ieee80211_calculate_rx_timestamp(local, rx_status,
177                                                          len + FCS_LEN, 24);
178                 ether_addr_copy(bss_meta.parent_bssid,
179                                 scan_sdata->vif.bss_conf.bssid);
180         }
181         rcu_read_unlock();
182
183         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
184                                               mgmt, len, GFP_ATOMIC);
185         if (!cbss)
186                 return NULL;
187
188         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
189                 elements = mgmt->u.probe_resp.variable;
190                 baselen = offsetof(struct ieee80211_mgmt,
191                                    u.probe_resp.variable);
192         } else {
193                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
194                 elements = mgmt->u.beacon.variable;
195         }
196
197         if (baselen > len)
198                 return NULL;
199
200         ieee802_11_parse_elems(elements, len - baselen, false, &elems,
201                                mgmt->bssid, cbss->bssid);
202
203         /* In case the signal is invalid update the status */
204         signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
205                 <= local->hw.wiphy->max_adj_channel_rssi_comp;
206         if (!signal_valid)
207                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
208
209         bss = (void *)cbss->priv;
210         ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
211
212         list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
213                 non_tx_bss = (void *)non_tx_cbss->priv;
214
215                 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
216                                                 rx_status, beacon);
217         }
218
219         return bss;
220 }
221
222 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
223                                         u32 scan_flags, const u8 *da)
224 {
225         if (!sdata)
226                 return false;
227         /* accept broadcast for OCE */
228         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
229             is_broadcast_ether_addr(da))
230                 return true;
231         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
232                 return true;
233         return ether_addr_equal(da, sdata->vif.addr);
234 }
235
236 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
237 {
238         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
239         struct ieee80211_sub_if_data *sdata1, *sdata2;
240         struct ieee80211_mgmt *mgmt = (void *)skb->data;
241         struct ieee80211_bss *bss;
242         struct ieee80211_channel *channel;
243
244         if (skb->len < 24 ||
245             (!ieee80211_is_probe_resp(mgmt->frame_control) &&
246              !ieee80211_is_beacon(mgmt->frame_control)))
247                 return;
248
249         sdata1 = rcu_dereference(local->scan_sdata);
250         sdata2 = rcu_dereference(local->sched_scan_sdata);
251
252         if (likely(!sdata1 && !sdata2))
253                 return;
254
255         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
256                 struct cfg80211_scan_request *scan_req;
257                 struct cfg80211_sched_scan_request *sched_scan_req;
258                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
259
260                 scan_req = rcu_dereference(local->scan_req);
261                 sched_scan_req = rcu_dereference(local->sched_scan_req);
262
263                 if (scan_req)
264                         scan_req_flags = scan_req->flags;
265
266                 if (sched_scan_req)
267                         sched_scan_req_flags = sched_scan_req->flags;
268
269                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
270                  * unless scanning with randomised address
271                  */
272                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
273                                                  mgmt->da) &&
274                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
275                                                  mgmt->da))
276                         return;
277         }
278
279         channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
280
281         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
282                 return;
283
284         bss = ieee80211_bss_info_update(local, rx_status,
285                                         mgmt, skb->len,
286                                         channel);
287         if (bss)
288                 ieee80211_rx_bss_put(local, bss);
289 }
290
291 static void
292 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
293                                enum nl80211_bss_scan_width scan_width)
294 {
295         memset(chandef, 0, sizeof(*chandef));
296         switch (scan_width) {
297         case NL80211_BSS_CHAN_WIDTH_5:
298                 chandef->width = NL80211_CHAN_WIDTH_5;
299                 break;
300         case NL80211_BSS_CHAN_WIDTH_10:
301                 chandef->width = NL80211_CHAN_WIDTH_10;
302                 break;
303         default:
304                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
305                 break;
306         }
307 }
308
309 /* return false if no more work */
310 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
311 {
312         struct cfg80211_scan_request *req;
313         struct cfg80211_chan_def chandef;
314         u8 bands_used = 0;
315         int i, ielen, n_chans;
316         u32 flags = 0;
317
318         req = rcu_dereference_protected(local->scan_req,
319                                         lockdep_is_held(&local->mtx));
320
321         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
322                 return false;
323
324         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
325                 for (i = 0; i < req->n_channels; i++) {
326                         local->hw_scan_req->req.channels[i] = req->channels[i];
327                         bands_used |= BIT(req->channels[i]->band);
328                 }
329
330                 n_chans = req->n_channels;
331         } else {
332                 do {
333                         if (local->hw_scan_band == NUM_NL80211_BANDS)
334                                 return false;
335
336                         n_chans = 0;
337
338                         for (i = 0; i < req->n_channels; i++) {
339                                 if (req->channels[i]->band !=
340                                     local->hw_scan_band)
341                                         continue;
342                                 local->hw_scan_req->req.channels[n_chans] =
343                                                         req->channels[i];
344                                 n_chans++;
345                                 bands_used |= BIT(req->channels[i]->band);
346                         }
347
348                         local->hw_scan_band++;
349                 } while (!n_chans);
350         }
351
352         local->hw_scan_req->req.n_channels = n_chans;
353         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
354
355         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
356                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
357
358         ielen = ieee80211_build_preq_ies(local,
359                                          (u8 *)local->hw_scan_req->req.ie,
360                                          local->hw_scan_ies_bufsize,
361                                          &local->hw_scan_req->ies,
362                                          req->ie, req->ie_len,
363                                          bands_used, req->rates, &chandef,
364                                          flags);
365         local->hw_scan_req->req.ie_len = ielen;
366         local->hw_scan_req->req.no_cck = req->no_cck;
367         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
368         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
369                         req->mac_addr_mask);
370         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
371
372         return true;
373 }
374
375 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
376 {
377         struct ieee80211_local *local = hw_to_local(hw);
378         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
379         bool was_scanning = local->scanning;
380         struct cfg80211_scan_request *scan_req;
381         struct ieee80211_sub_if_data *scan_sdata;
382         struct ieee80211_sub_if_data *sdata;
383
384         lockdep_assert_held(&local->mtx);
385
386         /*
387          * It's ok to abort a not-yet-running scan (that
388          * we have one at all will be verified by checking
389          * local->scan_req next), but not to complete it
390          * successfully.
391          */
392         if (WARN_ON(!local->scanning && !aborted))
393                 aborted = true;
394
395         if (WARN_ON(!local->scan_req))
396                 return;
397
398         if (hw_scan && !aborted &&
399             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
400             ieee80211_prep_hw_scan(local)) {
401                 int rc;
402
403                 rc = drv_hw_scan(local,
404                         rcu_dereference_protected(local->scan_sdata,
405                                                   lockdep_is_held(&local->mtx)),
406                         local->hw_scan_req);
407
408                 if (rc == 0)
409                         return;
410
411                 /* HW scan failed and is going to be reported as aborted,
412                  * so clear old scan info.
413                  */
414                 memset(&local->scan_info, 0, sizeof(local->scan_info));
415                 aborted = true;
416         }
417
418         kfree(local->hw_scan_req);
419         local->hw_scan_req = NULL;
420
421         scan_req = rcu_dereference_protected(local->scan_req,
422                                              lockdep_is_held(&local->mtx));
423
424         if (scan_req != local->int_scan_req) {
425                 local->scan_info.aborted = aborted;
426                 cfg80211_scan_done(scan_req, &local->scan_info);
427         }
428         RCU_INIT_POINTER(local->scan_req, NULL);
429
430         scan_sdata = rcu_dereference_protected(local->scan_sdata,
431                                                lockdep_is_held(&local->mtx));
432         RCU_INIT_POINTER(local->scan_sdata, NULL);
433
434         local->scanning = 0;
435         local->scan_chandef.chan = NULL;
436
437         /* Set power back to normal operating levels. */
438         ieee80211_hw_config(local, 0);
439
440         if (!hw_scan) {
441                 ieee80211_configure_filter(local);
442                 drv_sw_scan_complete(local, scan_sdata);
443                 ieee80211_offchannel_return(local);
444         }
445
446         ieee80211_recalc_idle(local);
447
448         ieee80211_mlme_notify_scan_completed(local);
449         ieee80211_ibss_notify_scan_completed(local);
450
451         /* Requeue all the work that might have been ignored while
452          * the scan was in progress; if there was none this will
453          * just be a no-op for the particular interface.
454          */
455         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
456                 if (ieee80211_sdata_running(sdata))
457                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
458         }
459
460         if (was_scanning)
461                 ieee80211_start_next_roc(local);
462 }
463
464 void ieee80211_scan_completed(struct ieee80211_hw *hw,
465                               struct cfg80211_scan_info *info)
466 {
467         struct ieee80211_local *local = hw_to_local(hw);
468
469         trace_api_scan_completed(local, info->aborted);
470
471         set_bit(SCAN_COMPLETED, &local->scanning);
472         if (info->aborted)
473                 set_bit(SCAN_ABORTED, &local->scanning);
474
475         memcpy(&local->scan_info, info, sizeof(*info));
476
477         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
478 }
479 EXPORT_SYMBOL(ieee80211_scan_completed);
480
481 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
482                                    struct ieee80211_sub_if_data *sdata)
483 {
484         /* Software scan is not supported in multi-channel cases */
485         if (local->use_chanctx)
486                 return -EOPNOTSUPP;
487
488         /*
489          * Hardware/driver doesn't support hw_scan, so use software
490          * scanning instead. First send a nullfunc frame with power save
491          * bit on so that AP will buffer the frames for us while we are not
492          * listening, then send probe requests to each channel and wait for
493          * the responses. After all channels are scanned, tune back to the
494          * original channel and send a nullfunc frame with power save bit
495          * off to trigger the AP to send us all the buffered frames.
496          *
497          * Note that while local->sw_scanning is true everything else but
498          * nullfunc frames and probe requests will be dropped in
499          * ieee80211_tx_h_check_assoc().
500          */
501         drv_sw_scan_start(local, sdata, local->scan_addr);
502
503         local->leave_oper_channel_time = jiffies;
504         local->next_scan_state = SCAN_DECISION;
505         local->scan_channel_idx = 0;
506
507         ieee80211_offchannel_stop_vifs(local);
508
509         /* ensure nullfunc is transmitted before leaving operating channel */
510         ieee80211_flush_queues(local, NULL, false);
511
512         ieee80211_configure_filter(local);
513
514         /* We need to set power level at maximum rate for scanning. */
515         ieee80211_hw_config(local, 0);
516
517         ieee80211_queue_delayed_work(&local->hw,
518                                      &local->scan_work, 0);
519
520         return 0;
521 }
522
523 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
524 {
525         struct ieee80211_local *local = sdata->local;
526         struct ieee80211_sub_if_data *sdata_iter;
527
528         if (!ieee80211_is_radar_required(local))
529                 return true;
530
531         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
532                 return false;
533
534         mutex_lock(&local->iflist_mtx);
535         list_for_each_entry(sdata_iter, &local->interfaces, list) {
536                 if (sdata_iter->wdev.cac_started) {
537                         mutex_unlock(&local->iflist_mtx);
538                         return false;
539                 }
540         }
541         mutex_unlock(&local->iflist_mtx);
542
543         return true;
544 }
545
546 static bool ieee80211_can_scan(struct ieee80211_local *local,
547                                struct ieee80211_sub_if_data *sdata)
548 {
549         if (!__ieee80211_can_leave_ch(sdata))
550                 return false;
551
552         if (!list_empty(&local->roc_list))
553                 return false;
554
555         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
556             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
557                 return false;
558
559         return true;
560 }
561
562 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
563 {
564         lockdep_assert_held(&local->mtx);
565
566         if (!local->scan_req || local->scanning)
567                 return;
568
569         if (!ieee80211_can_scan(local,
570                                 rcu_dereference_protected(
571                                         local->scan_sdata,
572                                         lockdep_is_held(&local->mtx))))
573                 return;
574
575         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
576                                      round_jiffies_relative(0));
577 }
578
579 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
580                                           const u8 *src, const u8 *dst,
581                                           const u8 *ssid, size_t ssid_len,
582                                           const u8 *ie, size_t ie_len,
583                                           u32 ratemask, u32 flags, u32 tx_flags,
584                                           struct ieee80211_channel *channel)
585 {
586         struct sk_buff *skb;
587         u32 txdata_flags = 0;
588
589         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
590                                         ssid, ssid_len,
591                                         ie, ie_len, flags);
592
593         if (skb) {
594                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
595                         struct ieee80211_hdr *hdr = (void *)skb->data;
596                         u16 sn = get_random_u32();
597
598                         txdata_flags |= IEEE80211_TX_NO_SEQNO;
599                         hdr->seq_ctrl =
600                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
601                 }
602                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
603                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
604                                           txdata_flags);
605         }
606 }
607
608 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
609                                             unsigned long *next_delay)
610 {
611         int i;
612         struct ieee80211_sub_if_data *sdata;
613         struct cfg80211_scan_request *scan_req;
614         enum nl80211_band band = local->hw.conf.chandef.chan->band;
615         u32 flags = 0, tx_flags;
616
617         scan_req = rcu_dereference_protected(local->scan_req,
618                                              lockdep_is_held(&local->mtx));
619
620         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
621         if (scan_req->no_cck)
622                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
623         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
624                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
625         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
626                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
627
628         sdata = rcu_dereference_protected(local->scan_sdata,
629                                           lockdep_is_held(&local->mtx));
630
631         for (i = 0; i < scan_req->n_ssids; i++)
632                 ieee80211_send_scan_probe_req(
633                         sdata, local->scan_addr, scan_req->bssid,
634                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
635                         scan_req->ie, scan_req->ie_len,
636                         scan_req->rates[band], flags,
637                         tx_flags, local->hw.conf.chandef.chan);
638
639         /*
640          * After sending probe requests, wait for probe responses
641          * on the channel.
642          */
643         *next_delay = IEEE80211_CHANNEL_TIME;
644         local->next_scan_state = SCAN_DECISION;
645 }
646
647 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
648                                   struct cfg80211_scan_request *req)
649 {
650         struct ieee80211_local *local = sdata->local;
651         bool hw_scan = local->ops->hw_scan;
652         int rc;
653
654         lockdep_assert_held(&local->mtx);
655
656         if (local->scan_req)
657                 return -EBUSY;
658
659         if (!__ieee80211_can_leave_ch(sdata))
660                 return -EBUSY;
661
662         if (!ieee80211_can_scan(local, sdata)) {
663                 /* wait for the work to finish/time out */
664                 rcu_assign_pointer(local->scan_req, req);
665                 rcu_assign_pointer(local->scan_sdata, sdata);
666                 return 0;
667         }
668
669  again:
670         if (hw_scan) {
671                 u8 *ies;
672
673                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
674
675                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
676                         int i, n_bands = 0;
677                         u8 bands_counted = 0;
678
679                         for (i = 0; i < req->n_channels; i++) {
680                                 if (bands_counted & BIT(req->channels[i]->band))
681                                         continue;
682                                 bands_counted |= BIT(req->channels[i]->band);
683                                 n_bands++;
684                         }
685
686                         local->hw_scan_ies_bufsize *= n_bands;
687                 }
688
689                 local->hw_scan_req = kmalloc(
690                                 sizeof(*local->hw_scan_req) +
691                                 req->n_channels * sizeof(req->channels[0]) +
692                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
693                 if (!local->hw_scan_req)
694                         return -ENOMEM;
695
696                 local->hw_scan_req->req.ssids = req->ssids;
697                 local->hw_scan_req->req.n_ssids = req->n_ssids;
698                 ies = (u8 *)local->hw_scan_req +
699                         sizeof(*local->hw_scan_req) +
700                         req->n_channels * sizeof(req->channels[0]);
701                 local->hw_scan_req->req.ie = ies;
702                 local->hw_scan_req->req.flags = req->flags;
703                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
704                 local->hw_scan_req->req.duration = req->duration;
705                 local->hw_scan_req->req.duration_mandatory =
706                         req->duration_mandatory;
707
708                 local->hw_scan_band = 0;
709
710                 /*
711                  * After allocating local->hw_scan_req, we must
712                  * go through until ieee80211_prep_hw_scan(), so
713                  * anything that might be changed here and leave
714                  * this function early must not go after this
715                  * allocation.
716                  */
717         }
718
719         rcu_assign_pointer(local->scan_req, req);
720         rcu_assign_pointer(local->scan_sdata, sdata);
721
722         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
723                 get_random_mask_addr(local->scan_addr,
724                                      req->mac_addr,
725                                      req->mac_addr_mask);
726         else
727                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
728
729         if (hw_scan) {
730                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
731         } else if ((req->n_channels == 1) &&
732                    (req->channels[0] == local->_oper_chandef.chan)) {
733                 /*
734                  * If we are scanning only on the operating channel
735                  * then we do not need to stop normal activities
736                  */
737                 unsigned long next_delay;
738
739                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
740
741                 ieee80211_recalc_idle(local);
742
743                 /* Notify driver scan is starting, keep order of operations
744                  * same as normal software scan, in case that matters. */
745                 drv_sw_scan_start(local, sdata, local->scan_addr);
746
747                 ieee80211_configure_filter(local); /* accept probe-responses */
748
749                 /* We need to ensure power level is at max for scanning. */
750                 ieee80211_hw_config(local, 0);
751
752                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
753                                                 IEEE80211_CHAN_RADAR)) ||
754                     !req->n_ssids) {
755                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
756                 } else {
757                         ieee80211_scan_state_send_probe(local, &next_delay);
758                         next_delay = IEEE80211_CHANNEL_TIME;
759                 }
760
761                 /* Now, just wait a bit and we are all done! */
762                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
763                                              next_delay);
764                 return 0;
765         } else {
766                 /* Do normal software scan */
767                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
768         }
769
770         ieee80211_recalc_idle(local);
771
772         if (hw_scan) {
773                 WARN_ON(!ieee80211_prep_hw_scan(local));
774                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
775         } else {
776                 rc = ieee80211_start_sw_scan(local, sdata);
777         }
778
779         if (rc) {
780                 kfree(local->hw_scan_req);
781                 local->hw_scan_req = NULL;
782                 local->scanning = 0;
783
784                 ieee80211_recalc_idle(local);
785
786                 local->scan_req = NULL;
787                 RCU_INIT_POINTER(local->scan_sdata, NULL);
788         }
789
790         if (hw_scan && rc == 1) {
791                 /*
792                  * we can't fall back to software for P2P-GO
793                  * as it must update NoA etc.
794                  */
795                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
796                                 NL80211_IFTYPE_P2P_GO)
797                         return -EOPNOTSUPP;
798                 hw_scan = false;
799                 goto again;
800         }
801
802         return rc;
803 }
804
805 static unsigned long
806 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
807 {
808         /*
809          * TODO: channel switching also consumes quite some time,
810          * add that delay as well to get a better estimation
811          */
812         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
813                 return IEEE80211_PASSIVE_CHANNEL_TIME;
814         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
815 }
816
817 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
818                                           unsigned long *next_delay)
819 {
820         bool associated = false;
821         bool tx_empty = true;
822         bool bad_latency;
823         struct ieee80211_sub_if_data *sdata;
824         struct ieee80211_channel *next_chan;
825         enum mac80211_scan_state next_scan_state;
826         struct cfg80211_scan_request *scan_req;
827
828         /*
829          * check if at least one STA interface is associated,
830          * check if at least one STA interface has pending tx frames
831          * and grab the lowest used beacon interval
832          */
833         mutex_lock(&local->iflist_mtx);
834         list_for_each_entry(sdata, &local->interfaces, list) {
835                 if (!ieee80211_sdata_running(sdata))
836                         continue;
837
838                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
839                         if (sdata->u.mgd.associated) {
840                                 associated = true;
841
842                                 if (!qdisc_all_tx_empty(sdata->dev)) {
843                                         tx_empty = false;
844                                         break;
845                                 }
846                         }
847                 }
848         }
849         mutex_unlock(&local->iflist_mtx);
850
851         scan_req = rcu_dereference_protected(local->scan_req,
852                                              lockdep_is_held(&local->mtx));
853
854         next_chan = scan_req->channels[local->scan_channel_idx];
855
856         /*
857          * we're currently scanning a different channel, let's
858          * see if we can scan another channel without interfering
859          * with the current traffic situation.
860          *
861          * Keep good latency, do not stay off-channel more than 125 ms.
862          */
863
864         bad_latency = time_after(jiffies +
865                                  ieee80211_scan_get_channel_time(next_chan),
866                                  local->leave_oper_channel_time + HZ / 8);
867
868         if (associated && !tx_empty) {
869                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
870                         next_scan_state = SCAN_ABORT;
871                 else
872                         next_scan_state = SCAN_SUSPEND;
873         } else if (associated && bad_latency) {
874                 next_scan_state = SCAN_SUSPEND;
875         } else {
876                 next_scan_state = SCAN_SET_CHANNEL;
877         }
878
879         local->next_scan_state = next_scan_state;
880
881         *next_delay = 0;
882 }
883
884 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
885                                              unsigned long *next_delay)
886 {
887         int skip;
888         struct ieee80211_channel *chan;
889         enum nl80211_bss_scan_width oper_scan_width;
890         struct cfg80211_scan_request *scan_req;
891
892         scan_req = rcu_dereference_protected(local->scan_req,
893                                              lockdep_is_held(&local->mtx));
894
895         skip = 0;
896         chan = scan_req->channels[local->scan_channel_idx];
897
898         local->scan_chandef.chan = chan;
899         local->scan_chandef.center_freq1 = chan->center_freq;
900         local->scan_chandef.center_freq2 = 0;
901         switch (scan_req->scan_width) {
902         case NL80211_BSS_CHAN_WIDTH_5:
903                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
904                 break;
905         case NL80211_BSS_CHAN_WIDTH_10:
906                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
907                 break;
908         case NL80211_BSS_CHAN_WIDTH_20:
909                 /* If scanning on oper channel, use whatever channel-type
910                  * is currently in use.
911                  */
912                 oper_scan_width = cfg80211_chandef_to_scan_width(
913                                         &local->_oper_chandef);
914                 if (chan == local->_oper_chandef.chan &&
915                     oper_scan_width == scan_req->scan_width)
916                         local->scan_chandef = local->_oper_chandef;
917                 else
918                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
919                 break;
920         }
921
922         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
923                 skip = 1;
924
925         /* advance state machine to next channel/band */
926         local->scan_channel_idx++;
927
928         if (skip) {
929                 /* if we skip this channel return to the decision state */
930                 local->next_scan_state = SCAN_DECISION;
931                 return;
932         }
933
934         /*
935          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
936          * (which unfortunately doesn't say _why_ step a) is done,
937          * but it waits for the probe delay or until a frame is
938          * received - and the received frame would update the NAV).
939          * For now, we do not support waiting until a frame is
940          * received.
941          *
942          * In any case, it is not necessary for a passive scan.
943          */
944         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
945             !scan_req->n_ssids) {
946                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
947                 local->next_scan_state = SCAN_DECISION;
948                 return;
949         }
950
951         /* active scan, send probes */
952         *next_delay = IEEE80211_PROBE_DELAY;
953         local->next_scan_state = SCAN_SEND_PROBE;
954 }
955
956 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
957                                          unsigned long *next_delay)
958 {
959         /* switch back to the operating channel */
960         local->scan_chandef.chan = NULL;
961         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
962
963         /* disable PS */
964         ieee80211_offchannel_return(local);
965
966         *next_delay = HZ / 5;
967         /* afterwards, resume scan & go to next channel */
968         local->next_scan_state = SCAN_RESUME;
969 }
970
971 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
972                                         unsigned long *next_delay)
973 {
974         ieee80211_offchannel_stop_vifs(local);
975
976         if (local->ops->flush) {
977                 ieee80211_flush_queues(local, NULL, false);
978                 *next_delay = 0;
979         } else
980                 *next_delay = HZ / 10;
981
982         /* remember when we left the operating channel */
983         local->leave_oper_channel_time = jiffies;
984
985         /* advance to the next channel to be scanned */
986         local->next_scan_state = SCAN_SET_CHANNEL;
987 }
988
989 void ieee80211_scan_work(struct work_struct *work)
990 {
991         struct ieee80211_local *local =
992                 container_of(work, struct ieee80211_local, scan_work.work);
993         struct ieee80211_sub_if_data *sdata;
994         struct cfg80211_scan_request *scan_req;
995         unsigned long next_delay = 0;
996         bool aborted;
997
998         mutex_lock(&local->mtx);
999
1000         if (!ieee80211_can_run_worker(local)) {
1001                 aborted = true;
1002                 goto out_complete;
1003         }
1004
1005         sdata = rcu_dereference_protected(local->scan_sdata,
1006                                           lockdep_is_held(&local->mtx));
1007         scan_req = rcu_dereference_protected(local->scan_req,
1008                                              lockdep_is_held(&local->mtx));
1009
1010         /* When scanning on-channel, the first-callback means completed. */
1011         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1012                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1013                 goto out_complete;
1014         }
1015
1016         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1017                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1018                 goto out_complete;
1019         }
1020
1021         if (!sdata || !scan_req)
1022                 goto out;
1023
1024         if (!local->scanning) {
1025                 int rc;
1026
1027                 RCU_INIT_POINTER(local->scan_req, NULL);
1028                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1029
1030                 rc = __ieee80211_start_scan(sdata, scan_req);
1031                 if (rc) {
1032                         /* need to complete scan in cfg80211 */
1033                         rcu_assign_pointer(local->scan_req, scan_req);
1034                         aborted = true;
1035                         goto out_complete;
1036                 } else
1037                         goto out;
1038         }
1039
1040         /*
1041          * as long as no delay is required advance immediately
1042          * without scheduling a new work
1043          */
1044         do {
1045                 if (!ieee80211_sdata_running(sdata)) {
1046                         aborted = true;
1047                         goto out_complete;
1048                 }
1049
1050                 switch (local->next_scan_state) {
1051                 case SCAN_DECISION:
1052                         /* if no more bands/channels left, complete scan */
1053                         if (local->scan_channel_idx >= scan_req->n_channels) {
1054                                 aborted = false;
1055                                 goto out_complete;
1056                         }
1057                         ieee80211_scan_state_decision(local, &next_delay);
1058                         break;
1059                 case SCAN_SET_CHANNEL:
1060                         ieee80211_scan_state_set_channel(local, &next_delay);
1061                         break;
1062                 case SCAN_SEND_PROBE:
1063                         ieee80211_scan_state_send_probe(local, &next_delay);
1064                         break;
1065                 case SCAN_SUSPEND:
1066                         ieee80211_scan_state_suspend(local, &next_delay);
1067                         break;
1068                 case SCAN_RESUME:
1069                         ieee80211_scan_state_resume(local, &next_delay);
1070                         break;
1071                 case SCAN_ABORT:
1072                         aborted = true;
1073                         goto out_complete;
1074                 }
1075         } while (next_delay == 0);
1076
1077         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1078         goto out;
1079
1080 out_complete:
1081         __ieee80211_scan_completed(&local->hw, aborted);
1082 out:
1083         mutex_unlock(&local->mtx);
1084 }
1085
1086 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1087                            struct cfg80211_scan_request *req)
1088 {
1089         int res;
1090
1091         mutex_lock(&sdata->local->mtx);
1092         res = __ieee80211_start_scan(sdata, req);
1093         mutex_unlock(&sdata->local->mtx);
1094
1095         return res;
1096 }
1097
1098 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1099                                 const u8 *ssid, u8 ssid_len,
1100                                 struct ieee80211_channel **channels,
1101                                 unsigned int n_channels,
1102                                 enum nl80211_bss_scan_width scan_width)
1103 {
1104         struct ieee80211_local *local = sdata->local;
1105         int ret = -EBUSY, i, n_ch = 0;
1106         enum nl80211_band band;
1107
1108         mutex_lock(&local->mtx);
1109
1110         /* busy scanning */
1111         if (local->scan_req)
1112                 goto unlock;
1113
1114         /* fill internal scan request */
1115         if (!channels) {
1116                 int max_n;
1117
1118                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1119                         if (!local->hw.wiphy->bands[band])
1120                                 continue;
1121
1122                         max_n = local->hw.wiphy->bands[band]->n_channels;
1123                         for (i = 0; i < max_n; i++) {
1124                                 struct ieee80211_channel *tmp_ch =
1125                                     &local->hw.wiphy->bands[band]->channels[i];
1126
1127                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1128                                                      IEEE80211_CHAN_DISABLED))
1129                                         continue;
1130
1131                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1132                                 n_ch++;
1133                         }
1134                 }
1135
1136                 if (WARN_ON_ONCE(n_ch == 0))
1137                         goto unlock;
1138
1139                 local->int_scan_req->n_channels = n_ch;
1140         } else {
1141                 for (i = 0; i < n_channels; i++) {
1142                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1143                                                   IEEE80211_CHAN_DISABLED))
1144                                 continue;
1145
1146                         local->int_scan_req->channels[n_ch] = channels[i];
1147                         n_ch++;
1148                 }
1149
1150                 if (WARN_ON_ONCE(n_ch == 0))
1151                         goto unlock;
1152
1153                 local->int_scan_req->n_channels = n_ch;
1154         }
1155
1156         local->int_scan_req->ssids = &local->scan_ssid;
1157         local->int_scan_req->n_ssids = 1;
1158         local->int_scan_req->scan_width = scan_width;
1159         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1160         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1161
1162         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1163  unlock:
1164         mutex_unlock(&local->mtx);
1165         return ret;
1166 }
1167
1168 /*
1169  * Only call this function when a scan can't be queued -- under RTNL.
1170  */
1171 void ieee80211_scan_cancel(struct ieee80211_local *local)
1172 {
1173         /*
1174          * We are canceling software scan, or deferred scan that was not
1175          * yet really started (see __ieee80211_start_scan ).
1176          *
1177          * Regarding hardware scan:
1178          * - we can not call  __ieee80211_scan_completed() as when
1179          *   SCAN_HW_SCANNING bit is set this function change
1180          *   local->hw_scan_req to operate on 5G band, what race with
1181          *   driver which can use local->hw_scan_req
1182          *
1183          * - we can not cancel scan_work since driver can schedule it
1184          *   by ieee80211_scan_completed(..., true) to finish scan
1185          *
1186          * Hence we only call the cancel_hw_scan() callback, but the low-level
1187          * driver is still responsible for calling ieee80211_scan_completed()
1188          * after the scan was completed/aborted.
1189          */
1190
1191         mutex_lock(&local->mtx);
1192         if (!local->scan_req)
1193                 goto out;
1194
1195         /*
1196          * We have a scan running and the driver already reported completion,
1197          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1198          * cancelled.
1199          */
1200         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1201             test_bit(SCAN_COMPLETED, &local->scanning)) {
1202                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1203                 goto out;
1204         }
1205
1206         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1207                 /*
1208                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1209                  * scan on another band.
1210                  */
1211                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1212                 if (local->ops->cancel_hw_scan)
1213                         drv_cancel_hw_scan(local,
1214                                 rcu_dereference_protected(local->scan_sdata,
1215                                                 lockdep_is_held(&local->mtx)));
1216                 goto out;
1217         }
1218
1219         /*
1220          * If the work is currently running, it must be blocked on
1221          * the mutex, but we'll set scan_sdata = NULL and it'll
1222          * simply exit once it acquires the mutex.
1223          */
1224         cancel_delayed_work(&local->scan_work);
1225         /* and clean up */
1226         memset(&local->scan_info, 0, sizeof(local->scan_info));
1227         __ieee80211_scan_completed(&local->hw, true);
1228 out:
1229         mutex_unlock(&local->mtx);
1230 }
1231
1232 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1233                                         struct cfg80211_sched_scan_request *req)
1234 {
1235         struct ieee80211_local *local = sdata->local;
1236         struct ieee80211_scan_ies sched_scan_ies = {};
1237         struct cfg80211_chan_def chandef;
1238         int ret, i, iebufsz, num_bands = 0;
1239         u32 rate_masks[NUM_NL80211_BANDS] = {};
1240         u8 bands_used = 0;
1241         u8 *ie;
1242         u32 flags = 0;
1243
1244         iebufsz = local->scan_ies_len + req->ie_len;
1245
1246         lockdep_assert_held(&local->mtx);
1247
1248         if (!local->ops->sched_scan_start)
1249                 return -ENOTSUPP;
1250
1251         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1252                 if (local->hw.wiphy->bands[i]) {
1253                         bands_used |= BIT(i);
1254                         rate_masks[i] = (u32) -1;
1255                         num_bands++;
1256                 }
1257         }
1258
1259         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1260                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1261
1262         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1263         if (!ie) {
1264                 ret = -ENOMEM;
1265                 goto out;
1266         }
1267
1268         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1269
1270         ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1271                                  &sched_scan_ies, req->ie,
1272                                  req->ie_len, bands_used, rate_masks, &chandef,
1273                                  flags);
1274
1275         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1276         if (ret == 0) {
1277                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1278                 rcu_assign_pointer(local->sched_scan_req, req);
1279         }
1280
1281         kfree(ie);
1282
1283 out:
1284         if (ret) {
1285                 /* Clean in case of failure after HW restart or upon resume. */
1286                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1287                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1288         }
1289
1290         return ret;
1291 }
1292
1293 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1294                                        struct cfg80211_sched_scan_request *req)
1295 {
1296         struct ieee80211_local *local = sdata->local;
1297         int ret;
1298
1299         mutex_lock(&local->mtx);
1300
1301         if (rcu_access_pointer(local->sched_scan_sdata)) {
1302                 mutex_unlock(&local->mtx);
1303                 return -EBUSY;
1304         }
1305
1306         ret = __ieee80211_request_sched_scan_start(sdata, req);
1307
1308         mutex_unlock(&local->mtx);
1309         return ret;
1310 }
1311
1312 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1313 {
1314         struct ieee80211_sub_if_data *sched_scan_sdata;
1315         int ret = -ENOENT;
1316
1317         mutex_lock(&local->mtx);
1318
1319         if (!local->ops->sched_scan_stop) {
1320                 ret = -ENOTSUPP;
1321                 goto out;
1322         }
1323
1324         /* We don't want to restart sched scan anymore. */
1325         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1326
1327         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1328                                                 lockdep_is_held(&local->mtx));
1329         if (sched_scan_sdata) {
1330                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1331                 if (!ret)
1332                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1333         }
1334 out:
1335         mutex_unlock(&local->mtx);
1336
1337         return ret;
1338 }
1339
1340 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1341 {
1342         struct ieee80211_local *local = hw_to_local(hw);
1343
1344         trace_api_sched_scan_results(local);
1345
1346         cfg80211_sched_scan_results(hw->wiphy, 0);
1347 }
1348 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1349
1350 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1351 {
1352         mutex_lock(&local->mtx);
1353
1354         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1355                 mutex_unlock(&local->mtx);
1356                 return;
1357         }
1358
1359         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1360
1361         /* If sched scan was aborted by the driver. */
1362         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1363
1364         mutex_unlock(&local->mtx);
1365
1366         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1367 }
1368
1369 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1370 {
1371         struct ieee80211_local *local =
1372                 container_of(work, struct ieee80211_local,
1373                              sched_scan_stopped_work);
1374
1375         ieee80211_sched_scan_end(local);
1376 }
1377
1378 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1379 {
1380         struct ieee80211_local *local = hw_to_local(hw);
1381
1382         trace_api_sched_scan_stopped(local);
1383
1384         /*
1385          * this shouldn't really happen, so for simplicity
1386          * simply ignore it, and let mac80211 reconfigure
1387          * the sched scan later on.
1388          */
1389         if (local->in_reconfig)
1390                 return;
1391
1392         schedule_work(&local->sched_scan_stopped_work);
1393 }
1394 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);