Merge tag 'arm-drivers-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
[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 = channel == cbss->channel;
205         if (!signal_valid)
206                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
207
208         bss = (void *)cbss->priv;
209         ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
210
211         list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
212                 non_tx_bss = (void *)non_tx_cbss->priv;
213
214                 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
215                                                 rx_status, beacon);
216         }
217
218         return bss;
219 }
220
221 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
222                                         u32 scan_flags, const u8 *da)
223 {
224         if (!sdata)
225                 return false;
226         /* accept broadcast for OCE */
227         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
228             is_broadcast_ether_addr(da))
229                 return true;
230         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
231                 return true;
232         return ether_addr_equal(da, sdata->vif.addr);
233 }
234
235 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
236 {
237         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
238         struct ieee80211_sub_if_data *sdata1, *sdata2;
239         struct ieee80211_mgmt *mgmt = (void *)skb->data;
240         struct ieee80211_bss *bss;
241         struct ieee80211_channel *channel;
242
243         if (skb->len < 24 ||
244             (!ieee80211_is_probe_resp(mgmt->frame_control) &&
245              !ieee80211_is_beacon(mgmt->frame_control)))
246                 return;
247
248         sdata1 = rcu_dereference(local->scan_sdata);
249         sdata2 = rcu_dereference(local->sched_scan_sdata);
250
251         if (likely(!sdata1 && !sdata2))
252                 return;
253
254         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
255                 struct cfg80211_scan_request *scan_req;
256                 struct cfg80211_sched_scan_request *sched_scan_req;
257                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
258
259                 scan_req = rcu_dereference(local->scan_req);
260                 sched_scan_req = rcu_dereference(local->sched_scan_req);
261
262                 if (scan_req)
263                         scan_req_flags = scan_req->flags;
264
265                 if (sched_scan_req)
266                         sched_scan_req_flags = sched_scan_req->flags;
267
268                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
269                  * unless scanning with randomised address
270                  */
271                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
272                                                  mgmt->da) &&
273                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
274                                                  mgmt->da))
275                         return;
276         }
277
278         channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
279
280         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
281                 return;
282
283         bss = ieee80211_bss_info_update(local, rx_status,
284                                         mgmt, skb->len,
285                                         channel);
286         if (bss)
287                 ieee80211_rx_bss_put(local, bss);
288 }
289
290 static void
291 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
292                                enum nl80211_bss_scan_width scan_width)
293 {
294         memset(chandef, 0, sizeof(*chandef));
295         switch (scan_width) {
296         case NL80211_BSS_CHAN_WIDTH_5:
297                 chandef->width = NL80211_CHAN_WIDTH_5;
298                 break;
299         case NL80211_BSS_CHAN_WIDTH_10:
300                 chandef->width = NL80211_CHAN_WIDTH_10;
301                 break;
302         default:
303                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
304                 break;
305         }
306 }
307
308 /* return false if no more work */
309 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
310 {
311         struct cfg80211_scan_request *req;
312         struct cfg80211_chan_def chandef;
313         u8 bands_used = 0;
314         int i, ielen, n_chans;
315         u32 flags = 0;
316
317         req = rcu_dereference_protected(local->scan_req,
318                                         lockdep_is_held(&local->mtx));
319
320         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
321                 return false;
322
323         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
324                 for (i = 0; i < req->n_channels; i++) {
325                         local->hw_scan_req->req.channels[i] = req->channels[i];
326                         bands_used |= BIT(req->channels[i]->band);
327                 }
328
329                 n_chans = req->n_channels;
330         } else {
331                 do {
332                         if (local->hw_scan_band == NUM_NL80211_BANDS)
333                                 return false;
334
335                         n_chans = 0;
336
337                         for (i = 0; i < req->n_channels; i++) {
338                                 if (req->channels[i]->band !=
339                                     local->hw_scan_band)
340                                         continue;
341                                 local->hw_scan_req->req.channels[n_chans] =
342                                                         req->channels[i];
343                                 n_chans++;
344                                 bands_used |= BIT(req->channels[i]->band);
345                         }
346
347                         local->hw_scan_band++;
348                 } while (!n_chans);
349         }
350
351         local->hw_scan_req->req.n_channels = n_chans;
352         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
353
354         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
355                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
356
357         ielen = ieee80211_build_preq_ies(local,
358                                          (u8 *)local->hw_scan_req->req.ie,
359                                          local->hw_scan_ies_bufsize,
360                                          &local->hw_scan_req->ies,
361                                          req->ie, req->ie_len,
362                                          bands_used, req->rates, &chandef,
363                                          flags);
364         local->hw_scan_req->req.ie_len = ielen;
365         local->hw_scan_req->req.no_cck = req->no_cck;
366         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
367         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
368                         req->mac_addr_mask);
369         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
370
371         return true;
372 }
373
374 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
375 {
376         struct ieee80211_local *local = hw_to_local(hw);
377         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
378         bool was_scanning = local->scanning;
379         struct cfg80211_scan_request *scan_req;
380         struct ieee80211_sub_if_data *scan_sdata;
381         struct ieee80211_sub_if_data *sdata;
382
383         lockdep_assert_held(&local->mtx);
384
385         /*
386          * It's ok to abort a not-yet-running scan (that
387          * we have one at all will be verified by checking
388          * local->scan_req next), but not to complete it
389          * successfully.
390          */
391         if (WARN_ON(!local->scanning && !aborted))
392                 aborted = true;
393
394         if (WARN_ON(!local->scan_req))
395                 return;
396
397         if (hw_scan && !aborted &&
398             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
399             ieee80211_prep_hw_scan(local)) {
400                 int rc;
401
402                 rc = drv_hw_scan(local,
403                         rcu_dereference_protected(local->scan_sdata,
404                                                   lockdep_is_held(&local->mtx)),
405                         local->hw_scan_req);
406
407                 if (rc == 0)
408                         return;
409
410                 /* HW scan failed and is going to be reported as aborted,
411                  * so clear old scan info.
412                  */
413                 memset(&local->scan_info, 0, sizeof(local->scan_info));
414                 aborted = true;
415         }
416
417         kfree(local->hw_scan_req);
418         local->hw_scan_req = NULL;
419
420         scan_req = rcu_dereference_protected(local->scan_req,
421                                              lockdep_is_held(&local->mtx));
422
423         if (scan_req != local->int_scan_req) {
424                 local->scan_info.aborted = aborted;
425                 cfg80211_scan_done(scan_req, &local->scan_info);
426         }
427         RCU_INIT_POINTER(local->scan_req, NULL);
428
429         scan_sdata = rcu_dereference_protected(local->scan_sdata,
430                                                lockdep_is_held(&local->mtx));
431         RCU_INIT_POINTER(local->scan_sdata, NULL);
432
433         local->scanning = 0;
434         local->scan_chandef.chan = NULL;
435
436         /* Set power back to normal operating levels. */
437         ieee80211_hw_config(local, 0);
438
439         if (!hw_scan) {
440                 ieee80211_configure_filter(local);
441                 drv_sw_scan_complete(local, scan_sdata);
442                 ieee80211_offchannel_return(local);
443         }
444
445         ieee80211_recalc_idle(local);
446
447         ieee80211_mlme_notify_scan_completed(local);
448         ieee80211_ibss_notify_scan_completed(local);
449
450         /* Requeue all the work that might have been ignored while
451          * the scan was in progress; if there was none this will
452          * just be a no-op for the particular interface.
453          */
454         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
455                 if (ieee80211_sdata_running(sdata))
456                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
457         }
458
459         if (was_scanning)
460                 ieee80211_start_next_roc(local);
461 }
462
463 void ieee80211_scan_completed(struct ieee80211_hw *hw,
464                               struct cfg80211_scan_info *info)
465 {
466         struct ieee80211_local *local = hw_to_local(hw);
467
468         trace_api_scan_completed(local, info->aborted);
469
470         set_bit(SCAN_COMPLETED, &local->scanning);
471         if (info->aborted)
472                 set_bit(SCAN_ABORTED, &local->scanning);
473
474         memcpy(&local->scan_info, info, sizeof(*info));
475
476         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
477 }
478 EXPORT_SYMBOL(ieee80211_scan_completed);
479
480 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
481                                    struct ieee80211_sub_if_data *sdata)
482 {
483         /* Software scan is not supported in multi-channel cases */
484         if (local->use_chanctx)
485                 return -EOPNOTSUPP;
486
487         /*
488          * Hardware/driver doesn't support hw_scan, so use software
489          * scanning instead. First send a nullfunc frame with power save
490          * bit on so that AP will buffer the frames for us while we are not
491          * listening, then send probe requests to each channel and wait for
492          * the responses. After all channels are scanned, tune back to the
493          * original channel and send a nullfunc frame with power save bit
494          * off to trigger the AP to send us all the buffered frames.
495          *
496          * Note that while local->sw_scanning is true everything else but
497          * nullfunc frames and probe requests will be dropped in
498          * ieee80211_tx_h_check_assoc().
499          */
500         drv_sw_scan_start(local, sdata, local->scan_addr);
501
502         local->leave_oper_channel_time = jiffies;
503         local->next_scan_state = SCAN_DECISION;
504         local->scan_channel_idx = 0;
505
506         ieee80211_offchannel_stop_vifs(local);
507
508         /* ensure nullfunc is transmitted before leaving operating channel */
509         ieee80211_flush_queues(local, NULL, false);
510
511         ieee80211_configure_filter(local);
512
513         /* We need to set power level at maximum rate for scanning. */
514         ieee80211_hw_config(local, 0);
515
516         ieee80211_queue_delayed_work(&local->hw,
517                                      &local->scan_work, 0);
518
519         return 0;
520 }
521
522 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
523 {
524         struct ieee80211_local *local = sdata->local;
525         struct ieee80211_sub_if_data *sdata_iter;
526
527         if (!ieee80211_is_radar_required(local))
528                 return true;
529
530         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
531                 return false;
532
533         mutex_lock(&local->iflist_mtx);
534         list_for_each_entry(sdata_iter, &local->interfaces, list) {
535                 if (sdata_iter->wdev.cac_started) {
536                         mutex_unlock(&local->iflist_mtx);
537                         return false;
538                 }
539         }
540         mutex_unlock(&local->iflist_mtx);
541
542         return true;
543 }
544
545 static bool ieee80211_can_scan(struct ieee80211_local *local,
546                                struct ieee80211_sub_if_data *sdata)
547 {
548         if (!__ieee80211_can_leave_ch(sdata))
549                 return false;
550
551         if (!list_empty(&local->roc_list))
552                 return false;
553
554         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
555             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
556                 return false;
557
558         return true;
559 }
560
561 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
562 {
563         lockdep_assert_held(&local->mtx);
564
565         if (!local->scan_req || local->scanning)
566                 return;
567
568         if (!ieee80211_can_scan(local,
569                                 rcu_dereference_protected(
570                                         local->scan_sdata,
571                                         lockdep_is_held(&local->mtx))))
572                 return;
573
574         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
575                                      round_jiffies_relative(0));
576 }
577
578 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
579                                           const u8 *src, const u8 *dst,
580                                           const u8 *ssid, size_t ssid_len,
581                                           const u8 *ie, size_t ie_len,
582                                           u32 ratemask, u32 flags, u32 tx_flags,
583                                           struct ieee80211_channel *channel)
584 {
585         struct sk_buff *skb;
586         u32 txdata_flags = 0;
587
588         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
589                                         ssid, ssid_len,
590                                         ie, ie_len, flags);
591
592         if (skb) {
593                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
594                         struct ieee80211_hdr *hdr = (void *)skb->data;
595                         u16 sn = get_random_u32();
596
597                         txdata_flags |= IEEE80211_TX_NO_SEQNO;
598                         hdr->seq_ctrl =
599                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
600                 }
601                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
602                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
603                                           txdata_flags);
604         }
605 }
606
607 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
608                                             unsigned long *next_delay)
609 {
610         int i;
611         struct ieee80211_sub_if_data *sdata;
612         struct cfg80211_scan_request *scan_req;
613         enum nl80211_band band = local->hw.conf.chandef.chan->band;
614         u32 flags = 0, tx_flags;
615
616         scan_req = rcu_dereference_protected(local->scan_req,
617                                              lockdep_is_held(&local->mtx));
618
619         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
620         if (scan_req->no_cck)
621                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
622         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
623                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
624         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
625                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
626
627         sdata = rcu_dereference_protected(local->scan_sdata,
628                                           lockdep_is_held(&local->mtx));
629
630         for (i = 0; i < scan_req->n_ssids; i++)
631                 ieee80211_send_scan_probe_req(
632                         sdata, local->scan_addr, scan_req->bssid,
633                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
634                         scan_req->ie, scan_req->ie_len,
635                         scan_req->rates[band], flags,
636                         tx_flags, local->hw.conf.chandef.chan);
637
638         /*
639          * After sending probe requests, wait for probe responses
640          * on the channel.
641          */
642         *next_delay = IEEE80211_CHANNEL_TIME;
643         local->next_scan_state = SCAN_DECISION;
644 }
645
646 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
647                                   struct cfg80211_scan_request *req)
648 {
649         struct ieee80211_local *local = sdata->local;
650         bool hw_scan = local->ops->hw_scan;
651         int rc;
652
653         lockdep_assert_held(&local->mtx);
654
655         if (local->scan_req)
656                 return -EBUSY;
657
658         if (!__ieee80211_can_leave_ch(sdata))
659                 return -EBUSY;
660
661         if (!ieee80211_can_scan(local, sdata)) {
662                 /* wait for the work to finish/time out */
663                 rcu_assign_pointer(local->scan_req, req);
664                 rcu_assign_pointer(local->scan_sdata, sdata);
665                 return 0;
666         }
667
668  again:
669         if (hw_scan) {
670                 u8 *ies;
671
672                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
673
674                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
675                         int i, n_bands = 0;
676                         u8 bands_counted = 0;
677
678                         for (i = 0; i < req->n_channels; i++) {
679                                 if (bands_counted & BIT(req->channels[i]->band))
680                                         continue;
681                                 bands_counted |= BIT(req->channels[i]->band);
682                                 n_bands++;
683                         }
684
685                         local->hw_scan_ies_bufsize *= n_bands;
686                 }
687
688                 local->hw_scan_req = kmalloc(
689                                 sizeof(*local->hw_scan_req) +
690                                 req->n_channels * sizeof(req->channels[0]) +
691                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
692                 if (!local->hw_scan_req)
693                         return -ENOMEM;
694
695                 local->hw_scan_req->req.ssids = req->ssids;
696                 local->hw_scan_req->req.n_ssids = req->n_ssids;
697                 ies = (u8 *)local->hw_scan_req +
698                         sizeof(*local->hw_scan_req) +
699                         req->n_channels * sizeof(req->channels[0]);
700                 local->hw_scan_req->req.ie = ies;
701                 local->hw_scan_req->req.flags = req->flags;
702                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
703                 local->hw_scan_req->req.duration = req->duration;
704                 local->hw_scan_req->req.duration_mandatory =
705                         req->duration_mandatory;
706
707                 local->hw_scan_band = 0;
708
709                 /*
710                  * After allocating local->hw_scan_req, we must
711                  * go through until ieee80211_prep_hw_scan(), so
712                  * anything that might be changed here and leave
713                  * this function early must not go after this
714                  * allocation.
715                  */
716         }
717
718         rcu_assign_pointer(local->scan_req, req);
719         rcu_assign_pointer(local->scan_sdata, sdata);
720
721         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
722                 get_random_mask_addr(local->scan_addr,
723                                      req->mac_addr,
724                                      req->mac_addr_mask);
725         else
726                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
727
728         if (hw_scan) {
729                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
730         } else if ((req->n_channels == 1) &&
731                    (req->channels[0] == local->_oper_chandef.chan)) {
732                 /*
733                  * If we are scanning only on the operating channel
734                  * then we do not need to stop normal activities
735                  */
736                 unsigned long next_delay;
737
738                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
739
740                 ieee80211_recalc_idle(local);
741
742                 /* Notify driver scan is starting, keep order of operations
743                  * same as normal software scan, in case that matters. */
744                 drv_sw_scan_start(local, sdata, local->scan_addr);
745
746                 ieee80211_configure_filter(local); /* accept probe-responses */
747
748                 /* We need to ensure power level is at max for scanning. */
749                 ieee80211_hw_config(local, 0);
750
751                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
752                                                 IEEE80211_CHAN_RADAR)) ||
753                     !req->n_ssids) {
754                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
755                 } else {
756                         ieee80211_scan_state_send_probe(local, &next_delay);
757                         next_delay = IEEE80211_CHANNEL_TIME;
758                 }
759
760                 /* Now, just wait a bit and we are all done! */
761                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
762                                              next_delay);
763                 return 0;
764         } else {
765                 /* Do normal software scan */
766                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
767         }
768
769         ieee80211_recalc_idle(local);
770
771         if (hw_scan) {
772                 WARN_ON(!ieee80211_prep_hw_scan(local));
773                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
774         } else {
775                 rc = ieee80211_start_sw_scan(local, sdata);
776         }
777
778         if (rc) {
779                 kfree(local->hw_scan_req);
780                 local->hw_scan_req = NULL;
781                 local->scanning = 0;
782
783                 ieee80211_recalc_idle(local);
784
785                 local->scan_req = NULL;
786                 RCU_INIT_POINTER(local->scan_sdata, NULL);
787         }
788
789         if (hw_scan && rc == 1) {
790                 /*
791                  * we can't fall back to software for P2P-GO
792                  * as it must update NoA etc.
793                  */
794                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
795                                 NL80211_IFTYPE_P2P_GO)
796                         return -EOPNOTSUPP;
797                 hw_scan = false;
798                 goto again;
799         }
800
801         return rc;
802 }
803
804 static unsigned long
805 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
806 {
807         /*
808          * TODO: channel switching also consumes quite some time,
809          * add that delay as well to get a better estimation
810          */
811         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
812                 return IEEE80211_PASSIVE_CHANNEL_TIME;
813         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
814 }
815
816 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
817                                           unsigned long *next_delay)
818 {
819         bool associated = false;
820         bool tx_empty = true;
821         bool bad_latency;
822         struct ieee80211_sub_if_data *sdata;
823         struct ieee80211_channel *next_chan;
824         enum mac80211_scan_state next_scan_state;
825         struct cfg80211_scan_request *scan_req;
826
827         /*
828          * check if at least one STA interface is associated,
829          * check if at least one STA interface has pending tx frames
830          * and grab the lowest used beacon interval
831          */
832         mutex_lock(&local->iflist_mtx);
833         list_for_each_entry(sdata, &local->interfaces, list) {
834                 if (!ieee80211_sdata_running(sdata))
835                         continue;
836
837                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
838                         if (sdata->u.mgd.associated) {
839                                 associated = true;
840
841                                 if (!qdisc_all_tx_empty(sdata->dev)) {
842                                         tx_empty = false;
843                                         break;
844                                 }
845                         }
846                 }
847         }
848         mutex_unlock(&local->iflist_mtx);
849
850         scan_req = rcu_dereference_protected(local->scan_req,
851                                              lockdep_is_held(&local->mtx));
852
853         next_chan = scan_req->channels[local->scan_channel_idx];
854
855         /*
856          * we're currently scanning a different channel, let's
857          * see if we can scan another channel without interfering
858          * with the current traffic situation.
859          *
860          * Keep good latency, do not stay off-channel more than 125 ms.
861          */
862
863         bad_latency = time_after(jiffies +
864                                  ieee80211_scan_get_channel_time(next_chan),
865                                  local->leave_oper_channel_time + HZ / 8);
866
867         if (associated && !tx_empty) {
868                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
869                         next_scan_state = SCAN_ABORT;
870                 else
871                         next_scan_state = SCAN_SUSPEND;
872         } else if (associated && bad_latency) {
873                 next_scan_state = SCAN_SUSPEND;
874         } else {
875                 next_scan_state = SCAN_SET_CHANNEL;
876         }
877
878         local->next_scan_state = next_scan_state;
879
880         *next_delay = 0;
881 }
882
883 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
884                                              unsigned long *next_delay)
885 {
886         int skip;
887         struct ieee80211_channel *chan;
888         enum nl80211_bss_scan_width oper_scan_width;
889         struct cfg80211_scan_request *scan_req;
890
891         scan_req = rcu_dereference_protected(local->scan_req,
892                                              lockdep_is_held(&local->mtx));
893
894         skip = 0;
895         chan = scan_req->channels[local->scan_channel_idx];
896
897         local->scan_chandef.chan = chan;
898         local->scan_chandef.center_freq1 = chan->center_freq;
899         local->scan_chandef.center_freq2 = 0;
900         switch (scan_req->scan_width) {
901         case NL80211_BSS_CHAN_WIDTH_5:
902                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
903                 break;
904         case NL80211_BSS_CHAN_WIDTH_10:
905                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
906                 break;
907         case NL80211_BSS_CHAN_WIDTH_20:
908                 /* If scanning on oper channel, use whatever channel-type
909                  * is currently in use.
910                  */
911                 oper_scan_width = cfg80211_chandef_to_scan_width(
912                                         &local->_oper_chandef);
913                 if (chan == local->_oper_chandef.chan &&
914                     oper_scan_width == scan_req->scan_width)
915                         local->scan_chandef = local->_oper_chandef;
916                 else
917                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
918                 break;
919         }
920
921         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
922                 skip = 1;
923
924         /* advance state machine to next channel/band */
925         local->scan_channel_idx++;
926
927         if (skip) {
928                 /* if we skip this channel return to the decision state */
929                 local->next_scan_state = SCAN_DECISION;
930                 return;
931         }
932
933         /*
934          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
935          * (which unfortunately doesn't say _why_ step a) is done,
936          * but it waits for the probe delay or until a frame is
937          * received - and the received frame would update the NAV).
938          * For now, we do not support waiting until a frame is
939          * received.
940          *
941          * In any case, it is not necessary for a passive scan.
942          */
943         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
944             !scan_req->n_ssids) {
945                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
946                 local->next_scan_state = SCAN_DECISION;
947                 return;
948         }
949
950         /* active scan, send probes */
951         *next_delay = IEEE80211_PROBE_DELAY;
952         local->next_scan_state = SCAN_SEND_PROBE;
953 }
954
955 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
956                                          unsigned long *next_delay)
957 {
958         /* switch back to the operating channel */
959         local->scan_chandef.chan = NULL;
960         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
961
962         /* disable PS */
963         ieee80211_offchannel_return(local);
964
965         *next_delay = HZ / 5;
966         /* afterwards, resume scan & go to next channel */
967         local->next_scan_state = SCAN_RESUME;
968 }
969
970 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
971                                         unsigned long *next_delay)
972 {
973         ieee80211_offchannel_stop_vifs(local);
974
975         if (local->ops->flush) {
976                 ieee80211_flush_queues(local, NULL, false);
977                 *next_delay = 0;
978         } else
979                 *next_delay = HZ / 10;
980
981         /* remember when we left the operating channel */
982         local->leave_oper_channel_time = jiffies;
983
984         /* advance to the next channel to be scanned */
985         local->next_scan_state = SCAN_SET_CHANNEL;
986 }
987
988 void ieee80211_scan_work(struct work_struct *work)
989 {
990         struct ieee80211_local *local =
991                 container_of(work, struct ieee80211_local, scan_work.work);
992         struct ieee80211_sub_if_data *sdata;
993         struct cfg80211_scan_request *scan_req;
994         unsigned long next_delay = 0;
995         bool aborted;
996
997         mutex_lock(&local->mtx);
998
999         if (!ieee80211_can_run_worker(local)) {
1000                 aborted = true;
1001                 goto out_complete;
1002         }
1003
1004         sdata = rcu_dereference_protected(local->scan_sdata,
1005                                           lockdep_is_held(&local->mtx));
1006         scan_req = rcu_dereference_protected(local->scan_req,
1007                                              lockdep_is_held(&local->mtx));
1008
1009         /* When scanning on-channel, the first-callback means completed. */
1010         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1011                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1012                 goto out_complete;
1013         }
1014
1015         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1016                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1017                 goto out_complete;
1018         }
1019
1020         if (!sdata || !scan_req)
1021                 goto out;
1022
1023         if (!local->scanning) {
1024                 int rc;
1025
1026                 RCU_INIT_POINTER(local->scan_req, NULL);
1027                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1028
1029                 rc = __ieee80211_start_scan(sdata, scan_req);
1030                 if (rc) {
1031                         /* need to complete scan in cfg80211 */
1032                         rcu_assign_pointer(local->scan_req, scan_req);
1033                         aborted = true;
1034                         goto out_complete;
1035                 } else
1036                         goto out;
1037         }
1038
1039         /*
1040          * as long as no delay is required advance immediately
1041          * without scheduling a new work
1042          */
1043         do {
1044                 if (!ieee80211_sdata_running(sdata)) {
1045                         aborted = true;
1046                         goto out_complete;
1047                 }
1048
1049                 switch (local->next_scan_state) {
1050                 case SCAN_DECISION:
1051                         /* if no more bands/channels left, complete scan */
1052                         if (local->scan_channel_idx >= scan_req->n_channels) {
1053                                 aborted = false;
1054                                 goto out_complete;
1055                         }
1056                         ieee80211_scan_state_decision(local, &next_delay);
1057                         break;
1058                 case SCAN_SET_CHANNEL:
1059                         ieee80211_scan_state_set_channel(local, &next_delay);
1060                         break;
1061                 case SCAN_SEND_PROBE:
1062                         ieee80211_scan_state_send_probe(local, &next_delay);
1063                         break;
1064                 case SCAN_SUSPEND:
1065                         ieee80211_scan_state_suspend(local, &next_delay);
1066                         break;
1067                 case SCAN_RESUME:
1068                         ieee80211_scan_state_resume(local, &next_delay);
1069                         break;
1070                 case SCAN_ABORT:
1071                         aborted = true;
1072                         goto out_complete;
1073                 }
1074         } while (next_delay == 0);
1075
1076         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1077         goto out;
1078
1079 out_complete:
1080         __ieee80211_scan_completed(&local->hw, aborted);
1081 out:
1082         mutex_unlock(&local->mtx);
1083 }
1084
1085 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1086                            struct cfg80211_scan_request *req)
1087 {
1088         int res;
1089
1090         mutex_lock(&sdata->local->mtx);
1091         res = __ieee80211_start_scan(sdata, req);
1092         mutex_unlock(&sdata->local->mtx);
1093
1094         return res;
1095 }
1096
1097 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1098                                 const u8 *ssid, u8 ssid_len,
1099                                 struct ieee80211_channel **channels,
1100                                 unsigned int n_channels,
1101                                 enum nl80211_bss_scan_width scan_width)
1102 {
1103         struct ieee80211_local *local = sdata->local;
1104         int ret = -EBUSY, i, n_ch = 0;
1105         enum nl80211_band band;
1106
1107         mutex_lock(&local->mtx);
1108
1109         /* busy scanning */
1110         if (local->scan_req)
1111                 goto unlock;
1112
1113         /* fill internal scan request */
1114         if (!channels) {
1115                 int max_n;
1116
1117                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1118                         if (!local->hw.wiphy->bands[band])
1119                                 continue;
1120
1121                         max_n = local->hw.wiphy->bands[band]->n_channels;
1122                         for (i = 0; i < max_n; i++) {
1123                                 struct ieee80211_channel *tmp_ch =
1124                                     &local->hw.wiphy->bands[band]->channels[i];
1125
1126                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1127                                                      IEEE80211_CHAN_DISABLED))
1128                                         continue;
1129
1130                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1131                                 n_ch++;
1132                         }
1133                 }
1134
1135                 if (WARN_ON_ONCE(n_ch == 0))
1136                         goto unlock;
1137
1138                 local->int_scan_req->n_channels = n_ch;
1139         } else {
1140                 for (i = 0; i < n_channels; i++) {
1141                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1142                                                   IEEE80211_CHAN_DISABLED))
1143                                 continue;
1144
1145                         local->int_scan_req->channels[n_ch] = channels[i];
1146                         n_ch++;
1147                 }
1148
1149                 if (WARN_ON_ONCE(n_ch == 0))
1150                         goto unlock;
1151
1152                 local->int_scan_req->n_channels = n_ch;
1153         }
1154
1155         local->int_scan_req->ssids = &local->scan_ssid;
1156         local->int_scan_req->n_ssids = 1;
1157         local->int_scan_req->scan_width = scan_width;
1158         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1159         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1160
1161         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1162  unlock:
1163         mutex_unlock(&local->mtx);
1164         return ret;
1165 }
1166
1167 /*
1168  * Only call this function when a scan can't be queued -- under RTNL.
1169  */
1170 void ieee80211_scan_cancel(struct ieee80211_local *local)
1171 {
1172         /*
1173          * We are canceling software scan, or deferred scan that was not
1174          * yet really started (see __ieee80211_start_scan ).
1175          *
1176          * Regarding hardware scan:
1177          * - we can not call  __ieee80211_scan_completed() as when
1178          *   SCAN_HW_SCANNING bit is set this function change
1179          *   local->hw_scan_req to operate on 5G band, what race with
1180          *   driver which can use local->hw_scan_req
1181          *
1182          * - we can not cancel scan_work since driver can schedule it
1183          *   by ieee80211_scan_completed(..., true) to finish scan
1184          *
1185          * Hence we only call the cancel_hw_scan() callback, but the low-level
1186          * driver is still responsible for calling ieee80211_scan_completed()
1187          * after the scan was completed/aborted.
1188          */
1189
1190         mutex_lock(&local->mtx);
1191         if (!local->scan_req)
1192                 goto out;
1193
1194         /*
1195          * We have a scan running and the driver already reported completion,
1196          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1197          * cancelled.
1198          */
1199         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1200             test_bit(SCAN_COMPLETED, &local->scanning)) {
1201                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1202                 goto out;
1203         }
1204
1205         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1206                 /*
1207                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1208                  * scan on another band.
1209                  */
1210                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1211                 if (local->ops->cancel_hw_scan)
1212                         drv_cancel_hw_scan(local,
1213                                 rcu_dereference_protected(local->scan_sdata,
1214                                                 lockdep_is_held(&local->mtx)));
1215                 goto out;
1216         }
1217
1218         /*
1219          * If the work is currently running, it must be blocked on
1220          * the mutex, but we'll set scan_sdata = NULL and it'll
1221          * simply exit once it acquires the mutex.
1222          */
1223         cancel_delayed_work(&local->scan_work);
1224         /* and clean up */
1225         memset(&local->scan_info, 0, sizeof(local->scan_info));
1226         __ieee80211_scan_completed(&local->hw, true);
1227 out:
1228         mutex_unlock(&local->mtx);
1229 }
1230
1231 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1232                                         struct cfg80211_sched_scan_request *req)
1233 {
1234         struct ieee80211_local *local = sdata->local;
1235         struct ieee80211_scan_ies sched_scan_ies = {};
1236         struct cfg80211_chan_def chandef;
1237         int ret, i, iebufsz, num_bands = 0;
1238         u32 rate_masks[NUM_NL80211_BANDS] = {};
1239         u8 bands_used = 0;
1240         u8 *ie;
1241         u32 flags = 0;
1242
1243         iebufsz = local->scan_ies_len + req->ie_len;
1244
1245         lockdep_assert_held(&local->mtx);
1246
1247         if (!local->ops->sched_scan_start)
1248                 return -ENOTSUPP;
1249
1250         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1251                 if (local->hw.wiphy->bands[i]) {
1252                         bands_used |= BIT(i);
1253                         rate_masks[i] = (u32) -1;
1254                         num_bands++;
1255                 }
1256         }
1257
1258         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1259                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1260
1261         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1262         if (!ie) {
1263                 ret = -ENOMEM;
1264                 goto out;
1265         }
1266
1267         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1268
1269         ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1270                                  &sched_scan_ies, req->ie,
1271                                  req->ie_len, bands_used, rate_masks, &chandef,
1272                                  flags);
1273
1274         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1275         if (ret == 0) {
1276                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1277                 rcu_assign_pointer(local->sched_scan_req, req);
1278         }
1279
1280         kfree(ie);
1281
1282 out:
1283         if (ret) {
1284                 /* Clean in case of failure after HW restart or upon resume. */
1285                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1286                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1287         }
1288
1289         return ret;
1290 }
1291
1292 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1293                                        struct cfg80211_sched_scan_request *req)
1294 {
1295         struct ieee80211_local *local = sdata->local;
1296         int ret;
1297
1298         mutex_lock(&local->mtx);
1299
1300         if (rcu_access_pointer(local->sched_scan_sdata)) {
1301                 mutex_unlock(&local->mtx);
1302                 return -EBUSY;
1303         }
1304
1305         ret = __ieee80211_request_sched_scan_start(sdata, req);
1306
1307         mutex_unlock(&local->mtx);
1308         return ret;
1309 }
1310
1311 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1312 {
1313         struct ieee80211_sub_if_data *sched_scan_sdata;
1314         int ret = -ENOENT;
1315
1316         mutex_lock(&local->mtx);
1317
1318         if (!local->ops->sched_scan_stop) {
1319                 ret = -ENOTSUPP;
1320                 goto out;
1321         }
1322
1323         /* We don't want to restart sched scan anymore. */
1324         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1325
1326         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1327                                                 lockdep_is_held(&local->mtx));
1328         if (sched_scan_sdata) {
1329                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1330                 if (!ret)
1331                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1332         }
1333 out:
1334         mutex_unlock(&local->mtx);
1335
1336         return ret;
1337 }
1338
1339 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1340 {
1341         struct ieee80211_local *local = hw_to_local(hw);
1342
1343         trace_api_sched_scan_results(local);
1344
1345         cfg80211_sched_scan_results(hw->wiphy, 0);
1346 }
1347 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1348
1349 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1350 {
1351         mutex_lock(&local->mtx);
1352
1353         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1354                 mutex_unlock(&local->mtx);
1355                 return;
1356         }
1357
1358         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1359
1360         /* If sched scan was aborted by the driver. */
1361         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1362
1363         mutex_unlock(&local->mtx);
1364
1365         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1366 }
1367
1368 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1369 {
1370         struct ieee80211_local *local =
1371                 container_of(work, struct ieee80211_local,
1372                              sched_scan_stopped_work);
1373
1374         ieee80211_sched_scan_end(local);
1375 }
1376
1377 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1378 {
1379         struct ieee80211_local *local = hw_to_local(hw);
1380
1381         trace_api_sched_scan_stopped(local);
1382
1383         /*
1384          * this shouldn't really happen, so for simplicity
1385          * simply ignore it, and let mac80211 reconfigure
1386          * the sched scan later on.
1387          */
1388         if (local->in_reconfig)
1389                 return;
1390
1391         schedule_work(&local->sched_scan_stopped_work);
1392 }
1393 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);