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);