net/mac80211/scan.c

   1 /*
   2  * Scanning implementation
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2004, Instant802 Networks, Inc.
   6  * Copyright 2005, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  * Copyright 2013-2015  Intel Mobile Communications GmbH
  10  * Copyright 2016-2017  Intel Deutschland GmbH
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #include <linux/if_arp.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/rtnetlink.h>
  20 #include <net/sch_generic.h>
  21 #include <linux/slab.h>
  22 #include <linux/export.h>
  23 #include <linux/random.h>
  24 #include <net/mac80211.h>
  25
  26 #include "ieee80211_i.h"
  27 #include "driver-ops.h"
  28 #include "mesh.h"
  29
  30 #define IEEE80211_PROBE_DELAY (HZ / 33)
  31 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  32 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  33
  34 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  35                           struct ieee80211_bss *bss)
  36 {
  37         if (!bss)
  38                 return;
  39         cfg80211_put_bss(local->hw.wiphy,
  40                          container_of((void *)bss, struct cfg80211_bss, priv));
  41 }
  42
  43 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  44 {
  45         u8 qos_info;
  46
  47         if (elems->wmm_info && elems->wmm_info_len == 7
  48             && elems->wmm_info[5] == 1)
  49                 qos_info = elems->wmm_info[6];
  50         else if (elems->wmm_param && elems->wmm_param_len == 24
  51                  && elems->wmm_param[5] == 1)
  52                 qos_info = elems->wmm_param[6];
  53         else
  54                 /* no valid wmm information or parameter element found */
  55                 return false;
  56
  57         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  58 }
  59
  60 struct ieee80211_bss *
  61 ieee80211_bss_info_update(struct ieee80211_local *local,
  62                           struct ieee80211_rx_status *rx_status,
  63                           struct ieee80211_mgmt *mgmt, size_t len,
  64                           struct ieee802_11_elems *elems,
  65                           struct ieee80211_channel *channel)
  66 {
  67         bool beacon = ieee80211_is_beacon(mgmt->frame_control);
  68         struct cfg80211_bss *cbss;
  69         struct ieee80211_bss *bss;
  70         int clen, srlen;
  71         struct cfg80211_inform_bss bss_meta = {
  72                 .boottime_ns = rx_status->boottime_ns,
  73         };
  74         bool signal_valid;
  75         struct ieee80211_sub_if_data *scan_sdata;
  76
  77         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
  78                 bss_meta.signal = 0; /* invalid signal indication */
  79         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
  80                 bss_meta.signal = rx_status->signal * 100;
  81         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
  82                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
  83
  84         bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
  85         if (rx_status->bw == RATE_INFO_BW_5)
  86                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
  87         else if (rx_status->bw == RATE_INFO_BW_10)
  88                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
  89
  90         bss_meta.chan = channel;
  91
  92         rcu_read_lock();
  93         scan_sdata = rcu_dereference(local->scan_sdata);
  94         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
  95             scan_sdata->vif.bss_conf.assoc &&
  96             ieee80211_have_rx_timestamp(rx_status)) {
  97                 bss_meta.parent_tsf =
  98                         ieee80211_calculate_rx_timestamp(local, rx_status,
  99                                                          len + FCS_LEN, 24);
 100                 ether_addr_copy(bss_meta.parent_bssid,
 101                                 scan_sdata->vif.bss_conf.bssid);
 102         }
 103         rcu_read_unlock();
 104
 105         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 106                                               mgmt, len, GFP_ATOMIC);
 107         if (!cbss)
 108                 return NULL;
 109         /* In case the signal is invalid update the status */
 110         signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
 111                 <= local->hw.wiphy->max_adj_channel_rssi_comp;
 112         if (!signal_valid)
 113                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 114
 115         bss = (void *)cbss->priv;
 116
 117         if (beacon)
 118                 bss->device_ts_beacon = rx_status->device_timestamp;
 119         else
 120                 bss->device_ts_presp = rx_status->device_timestamp;
 121
 122         if (elems->parse_error) {
 123                 if (beacon)
 124                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
 125                 else
 126                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
 127         } else {
 128                 if (beacon)
 129                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
 130                 else
 131                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
 132         }
 133
 134         /* save the ERP value so that it is available at association time */
 135         if (elems->erp_info && (!elems->parse_error ||
 136                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
 137                 bss->erp_value = elems->erp_info[0];
 138                 bss->has_erp_value = true;
 139                 if (!elems->parse_error)
 140                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
 141         }
 142
 143         /* replace old supported rates if we get new values */
 144         if (!elems->parse_error ||
 145             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
 146                 srlen = 0;
 147                 if (elems->supp_rates) {
 148                         clen = IEEE80211_MAX_SUPP_RATES;
 149                         if (clen > elems->supp_rates_len)
 150                                 clen = elems->supp_rates_len;
 151                         memcpy(bss->supp_rates, elems->supp_rates, clen);
 152                         srlen += clen;
 153                 }
 154                 if (elems->ext_supp_rates) {
 155                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 156                         if (clen > elems->ext_supp_rates_len)
 157                                 clen = elems->ext_supp_rates_len;
 158                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 159                                clen);
 160                         srlen += clen;
 161                 }
 162                 if (srlen) {
 163                         bss->supp_rates_len = srlen;
 164                         if (!elems->parse_error)
 165                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 166                 }
 167         }
 168
 169         if (!elems->parse_error ||
 170             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 171                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
 172                 bss->uapsd_supported = is_uapsd_supported(elems);
 173                 if (!elems->parse_error)
 174                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 175         }
 176
 177         if (beacon) {
 178                 struct ieee80211_supported_band *sband =
 179                         local->hw.wiphy->bands[rx_status->band];
 180                 if (!(rx_status->encoding == RX_ENC_HT) &&
 181                     !(rx_status->encoding == RX_ENC_VHT))
 182                         bss->beacon_rate =
 183                                 &sband->bitrates[rx_status->rate_idx];
 184         }
 185
 186         return bss;
 187 }
 188
 189 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 190                                         u32 scan_flags, const u8 *da)
 191 {
 192         if (!sdata)
 193                 return false;
 194         /* accept broadcast for OCE */
 195         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 196             is_broadcast_ether_addr(da))
 197                 return true;
 198         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 199                 return true;
 200         return ether_addr_equal(da, sdata->vif.addr);
 201 }
 202
 203 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 204 {
 205         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 206         struct ieee80211_sub_if_data *sdata1, *sdata2;
 207         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 208         struct ieee80211_bss *bss;
 209         u8 *elements;
 210         struct ieee80211_channel *channel;
 211         size_t baselen;
 212         struct ieee802_11_elems elems;
 213
 214         if (skb->len < 24 ||
 215             (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 216              !ieee80211_is_beacon(mgmt->frame_control)))
 217                 return;
 218
 219         sdata1 = rcu_dereference(local->scan_sdata);
 220         sdata2 = rcu_dereference(local->sched_scan_sdata);
 221
 222         if (likely(!sdata1 && !sdata2))
 223                 return;
 224
 225         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 226                 struct cfg80211_scan_request *scan_req;
 227                 struct cfg80211_sched_scan_request *sched_scan_req;
 228                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 229
 230                 scan_req = rcu_dereference(local->scan_req);
 231                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 232
 233                 if (scan_req)
 234                         scan_req_flags = scan_req->flags;
 235
 236                 if (sched_scan_req)
 237                         sched_scan_req_flags = sched_scan_req->flags;
 238
 239                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 240                  * unless scanning with randomised address
 241                  */
 242                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 243                                                  mgmt->da) &&
 244                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 245                                                  mgmt->da))
 246                         return;
 247
 248                 elements = mgmt->u.probe_resp.variable;
 249                 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
 250         } else {
 251                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 252                 elements = mgmt->u.beacon.variable;
 253         }
 254
 255         if (baselen > skb->len)
 256                 return;
 257
 258         ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
 259
 260         channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
 261
 262         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 263                 return;
 264
 265         bss = ieee80211_bss_info_update(local, rx_status,
 266                                         mgmt, skb->len, &elems,
 267                                         channel);
 268         if (bss)
 269                 ieee80211_rx_bss_put(local, bss);
 270 }
 271
 272 static void
 273 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 274                                enum nl80211_bss_scan_width scan_width)
 275 {
 276         memset(chandef, 0, sizeof(*chandef));
 277         switch (scan_width) {
 278         case NL80211_BSS_CHAN_WIDTH_5:
 279                 chandef->width = NL80211_CHAN_WIDTH_5;
 280                 break;
 281         case NL80211_BSS_CHAN_WIDTH_10:
 282                 chandef->width = NL80211_CHAN_WIDTH_10;
 283                 break;
 284         default:
 285                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 286                 break;
 287         }
 288 }
 289
 290 /* return false if no more work */
 291 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 292 {
 293         struct cfg80211_scan_request *req;
 294         struct cfg80211_chan_def chandef;
 295         u8 bands_used = 0;
 296         int i, ielen, n_chans;
 297         u32 flags = 0;
 298
 299         req = rcu_dereference_protected(local->scan_req,
 300                                         lockdep_is_held(&local->mtx));
 301
 302         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 303                 return false;
 304
 305         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 306                 for (i = 0; i < req->n_channels; i++) {
 307                         local->hw_scan_req->req.channels[i] = req->channels[i];
 308                         bands_used |= BIT(req->channels[i]->band);
 309                 }
 310
 311                 n_chans = req->n_channels;
 312         } else {
 313                 do {
 314                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 315                                 return false;
 316
 317                         n_chans = 0;
 318
 319                         for (i = 0; i < req->n_channels; i++) {
 320                                 if (req->channels[i]->band !=
 321                                     local->hw_scan_band)
 322                                         continue;
 323                                 local->hw_scan_req->req.channels[n_chans] =
 324                                                         req->channels[i];
 325                                 n_chans++;
 326                                 bands_used |= BIT(req->channels[i]->band);
 327                         }
 328
 329                         local->hw_scan_band++;
 330                 } while (!n_chans);
 331         }
 332
 333         local->hw_scan_req->req.n_channels = n_chans;
 334         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 335
 336         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 337                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 338
 339         ielen = ieee80211_build_preq_ies(local,
 340                                          (u8 *)local->hw_scan_req->req.ie,
 341                                          local->hw_scan_ies_bufsize,
 342                                          &local->hw_scan_req->ies,
 343                                          req->ie, req->ie_len,
 344                                          bands_used, req->rates, &chandef,
 345                                          flags);
 346         local->hw_scan_req->req.ie_len = ielen;
 347         local->hw_scan_req->req.no_cck = req->no_cck;
 348         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 349         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 350                         req->mac_addr_mask);
 351         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 352
 353         return true;
 354 }
 355
 356 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 357 {
 358         struct ieee80211_local *local = hw_to_local(hw);
 359         bool hw_scan = local->ops->hw_scan;
 360         bool was_scanning = local->scanning;
 361         struct cfg80211_scan_request *scan_req;
 362         struct ieee80211_sub_if_data *scan_sdata;
 363         struct ieee80211_sub_if_data *sdata;
 364
 365         lockdep_assert_held(&local->mtx);
 366
 367         /*
 368          * It's ok to abort a not-yet-running scan (that
 369          * we have one at all will be verified by checking
 370          * local->scan_req next), but not to complete it
 371          * successfully.
 372          */
 373         if (WARN_ON(!local->scanning && !aborted))
 374                 aborted = true;
 375
 376         if (WARN_ON(!local->scan_req))
 377                 return;
 378
 379         if (hw_scan && !aborted &&
 380             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 381             ieee80211_prep_hw_scan(local)) {
 382                 int rc;
 383
 384                 rc = drv_hw_scan(local,
 385                         rcu_dereference_protected(local->scan_sdata,
 386                                                   lockdep_is_held(&local->mtx)),
 387                         local->hw_scan_req);
 388
 389                 if (rc == 0)
 390                         return;
 391
 392                 /* HW scan failed and is going to be reported as aborted,
 393                  * so clear old scan info.
 394                  */
 395                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 396                 aborted = true;
 397         }
 398
 399         kfree(local->hw_scan_req);
 400         local->hw_scan_req = NULL;
 401
 402         scan_req = rcu_dereference_protected(local->scan_req,
 403                                              lockdep_is_held(&local->mtx));
 404
 405         if (scan_req != local->int_scan_req) {
 406                 local->scan_info.aborted = aborted;
 407                 cfg80211_scan_done(scan_req, &local->scan_info);
 408         }
 409         RCU_INIT_POINTER(local->scan_req, NULL);
 410
 411         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 412                                                lockdep_is_held(&local->mtx));
 413         RCU_INIT_POINTER(local->scan_sdata, NULL);
 414
 415         local->scanning = 0;
 416         local->scan_chandef.chan = NULL;
 417
 418         /* Set power back to normal operating levels. */
 419         ieee80211_hw_config(local, 0);
 420
 421         if (!hw_scan) {
 422                 ieee80211_configure_filter(local);
 423                 drv_sw_scan_complete(local, scan_sdata);
 424                 ieee80211_offchannel_return(local);
 425         }
 426
 427         ieee80211_recalc_idle(local);
 428
 429         ieee80211_mlme_notify_scan_completed(local);
 430         ieee80211_ibss_notify_scan_completed(local);
 431
 432         /* Requeue all the work that might have been ignored while
 433          * the scan was in progress; if there was none this will
 434          * just be a no-op for the particular interface.
 435          */
 436         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 437                 if (ieee80211_sdata_running(sdata))
 438                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 439         }
 440
 441         if (was_scanning)
 442                 ieee80211_start_next_roc(local);
 443 }
 444
 445 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 446                               struct cfg80211_scan_info *info)
 447 {
 448         struct ieee80211_local *local = hw_to_local(hw);
 449
 450         trace_api_scan_completed(local, info->aborted);
 451
 452         set_bit(SCAN_COMPLETED, &local->scanning);
 453         if (info->aborted)
 454                 set_bit(SCAN_ABORTED, &local->scanning);
 455
 456         memcpy(&local->scan_info, info, sizeof(*info));
 457
 458         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 459 }
 460 EXPORT_SYMBOL(ieee80211_scan_completed);
 461
 462 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 463                                    struct ieee80211_sub_if_data *sdata)
 464 {
 465         /* Software scan is not supported in multi-channel cases */
 466         if (local->use_chanctx)
 467                 return -EOPNOTSUPP;
 468
 469         /*
 470          * Hardware/driver doesn't support hw_scan, so use software
 471          * scanning instead. First send a nullfunc frame with power save
 472          * bit on so that AP will buffer the frames for us while we are not
 473          * listening, then send probe requests to each channel and wait for
 474          * the responses. After all channels are scanned, tune back to the
 475          * original channel and send a nullfunc frame with power save bit
 476          * off to trigger the AP to send us all the buffered frames.
 477          *
 478          * Note that while local->sw_scanning is true everything else but
 479          * nullfunc frames and probe requests will be dropped in
 480          * ieee80211_tx_h_check_assoc().
 481          */
 482         drv_sw_scan_start(local, sdata, local->scan_addr);
 483
 484         local->leave_oper_channel_time = jiffies;
 485         local->next_scan_state = SCAN_DECISION;
 486         local->scan_channel_idx = 0;
 487
 488         ieee80211_offchannel_stop_vifs(local);
 489
 490         /* ensure nullfunc is transmitted before leaving operating channel */
 491         ieee80211_flush_queues(local, NULL, false);
 492
 493         ieee80211_configure_filter(local);
 494
 495         /* We need to set power level at maximum rate for scanning. */
 496         ieee80211_hw_config(local, 0);
 497
 498         ieee80211_queue_delayed_work(&local->hw,
 499                                      &local->scan_work, 0);
 500
 501         return 0;
 502 }
 503
 504 static bool ieee80211_can_scan(struct ieee80211_local *local,
 505                                struct ieee80211_sub_if_data *sdata)
 506 {
 507         if (ieee80211_is_radar_required(local))
 508                 return false;
 509
 510         if (!list_empty(&local->roc_list))
 511                 return false;
 512
 513         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 514             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 515                 return false;
 516
 517         return true;
 518 }
 519
 520 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 521 {
 522         lockdep_assert_held(&local->mtx);
 523
 524         if (!local->scan_req || local->scanning)
 525                 return;
 526
 527         if (!ieee80211_can_scan(local,
 528                                 rcu_dereference_protected(
 529                                         local->scan_sdata,
 530                                         lockdep_is_held(&local->mtx))))
 531                 return;
 532
 533         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 534                                      round_jiffies_relative(0));
 535 }
 536
 537 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 538                                           const u8 *src, const u8 *dst,
 539                                           const u8 *ssid, size_t ssid_len,
 540                                           const u8 *ie, size_t ie_len,
 541                                           u32 ratemask, u32 flags, u32 tx_flags,
 542                                           struct ieee80211_channel *channel)
 543 {
 544         struct sk_buff *skb;
 545         u32 txdata_flags = 0;
 546
 547         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 548                                         ssid, ssid_len,
 549                                         ie, ie_len, flags);
 550
 551         if (skb) {
 552                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 553                         struct ieee80211_hdr *hdr = (void *)skb->data;
 554                         u16 sn = get_random_u32();
 555
 556                         txdata_flags |= IEEE80211_TX_NO_SEQNO;
 557                         hdr->seq_ctrl =
 558                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 559                 }
 560                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 561                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
 562                                           txdata_flags);
 563         }
 564 }
 565
 566 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 567                                             unsigned long *next_delay)
 568 {
 569         int i;
 570         struct ieee80211_sub_if_data *sdata;
 571         struct cfg80211_scan_request *scan_req;
 572         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 573         u32 flags = 0, tx_flags;
 574
 575         scan_req = rcu_dereference_protected(local->scan_req,
 576                                              lockdep_is_held(&local->mtx));
 577
 578         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 579         if (scan_req->no_cck)
 580                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 581         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 582                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 583         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 584                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 585
 586         sdata = rcu_dereference_protected(local->scan_sdata,
 587                                           lockdep_is_held(&local->mtx));
 588
 589         for (i = 0; i < scan_req->n_ssids; i++)
 590                 ieee80211_send_scan_probe_req(
 591                         sdata, local->scan_addr, scan_req->bssid,
 592                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 593                         scan_req->ie, scan_req->ie_len,
 594                         scan_req->rates[band], flags,
 595                         tx_flags, local->hw.conf.chandef.chan);
 596
 597         /*
 598          * After sending probe requests, wait for probe responses
 599          * on the channel.
 600          */
 601         *next_delay = IEEE80211_CHANNEL_TIME;
 602         local->next_scan_state = SCAN_DECISION;
 603 }
 604
 605 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 606                                   struct cfg80211_scan_request *req)
 607 {
 608         struct ieee80211_local *local = sdata->local;
 609         int rc;
 610
 611         lockdep_assert_held(&local->mtx);
 612
 613         if (local->scan_req || ieee80211_is_radar_required(local))
 614                 return -EBUSY;
 615
 616         if (!ieee80211_can_scan(local, sdata)) {
 617                 /* wait for the work to finish/time out */
 618                 rcu_assign_pointer(local->scan_req, req);
 619                 rcu_assign_pointer(local->scan_sdata, sdata);
 620                 return 0;
 621         }
 622
 623         if (local->ops->hw_scan) {
 624                 u8 *ies;
 625
 626                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 627
 628                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 629                         int i, n_bands = 0;
 630                         u8 bands_counted = 0;
 631
 632                         for (i = 0; i < req->n_channels; i++) {
 633                                 if (bands_counted & BIT(req->channels[i]->band))
 634                                         continue;
 635                                 bands_counted |= BIT(req->channels[i]->band);
 636                                 n_bands++;
 637                         }
 638
 639                         local->hw_scan_ies_bufsize *= n_bands;
 640                 }
 641
 642                 local->hw_scan_req = kmalloc(
 643                                 sizeof(*local->hw_scan_req) +
 644                                 req->n_channels * sizeof(req->channels[0]) +
 645                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 646                 if (!local->hw_scan_req)
 647                         return -ENOMEM;
 648
 649                 local->hw_scan_req->req.ssids = req->ssids;
 650                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 651                 ies = (u8 *)local->hw_scan_req +
 652                         sizeof(*local->hw_scan_req) +
 653                         req->n_channels * sizeof(req->channels[0]);
 654                 local->hw_scan_req->req.ie = ies;
 655                 local->hw_scan_req->req.flags = req->flags;
 656                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 657                 local->hw_scan_req->req.duration = req->duration;
 658                 local->hw_scan_req->req.duration_mandatory =
 659                         req->duration_mandatory;
 660
 661                 local->hw_scan_band = 0;
 662
 663                 /*
 664                  * After allocating local->hw_scan_req, we must
 665                  * go through until ieee80211_prep_hw_scan(), so
 666                  * anything that might be changed here and leave
 667                  * this function early must not go after this
 668                  * allocation.
 669                  */
 670         }
 671
 672         rcu_assign_pointer(local->scan_req, req);
 673         rcu_assign_pointer(local->scan_sdata, sdata);
 674
 675         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 676                 get_random_mask_addr(local->scan_addr,
 677                                      req->mac_addr,
 678                                      req->mac_addr_mask);
 679         else
 680                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 681
 682         if (local->ops->hw_scan) {
 683                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 684         } else if ((req->n_channels == 1) &&
 685                    (req->channels[0] == local->_oper_chandef.chan)) {
 686                 /*
 687                  * If we are scanning only on the operating channel
 688                  * then we do not need to stop normal activities
 689                  */
 690                 unsigned long next_delay;
 691
 692                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 693
 694                 ieee80211_recalc_idle(local);
 695
 696                 /* Notify driver scan is starting, keep order of operations
 697                  * same as normal software scan, in case that matters. */
 698                 drv_sw_scan_start(local, sdata, local->scan_addr);
 699
 700                 ieee80211_configure_filter(local); /* accept probe-responses */
 701
 702                 /* We need to ensure power level is at max for scanning. */
 703                 ieee80211_hw_config(local, 0);
 704
 705                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 706                                                 IEEE80211_CHAN_RADAR)) ||
 707                     !req->n_ssids) {
 708                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 709                 } else {
 710                         ieee80211_scan_state_send_probe(local, &next_delay);
 711                         next_delay = IEEE80211_CHANNEL_TIME;
 712                 }
 713
 714                 /* Now, just wait a bit and we are all done! */
 715                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 716                                              next_delay);
 717                 return 0;
 718         } else {
 719                 /* Do normal software scan */
 720                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 721         }
 722
 723         ieee80211_recalc_idle(local);
 724
 725         if (local->ops->hw_scan) {
 726                 WARN_ON(!ieee80211_prep_hw_scan(local));
 727                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 728         } else {
 729                 rc = ieee80211_start_sw_scan(local, sdata);
 730         }
 731
 732         if (rc) {
 733                 kfree(local->hw_scan_req);
 734                 local->hw_scan_req = NULL;
 735                 local->scanning = 0;
 736
 737                 ieee80211_recalc_idle(local);
 738
 739                 local->scan_req = NULL;
 740                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 741         }
 742
 743         return rc;
 744 }
 745
 746 static unsigned long
 747 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 748 {
 749         /*
 750          * TODO: channel switching also consumes quite some time,
 751          * add that delay as well to get a better estimation
 752          */
 753         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 754                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 755         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 756 }
 757
 758 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 759                                           unsigned long *next_delay)
 760 {
 761         bool associated = false;
 762         bool tx_empty = true;
 763         bool bad_latency;
 764         struct ieee80211_sub_if_data *sdata;
 765         struct ieee80211_channel *next_chan;
 766         enum mac80211_scan_state next_scan_state;
 767         struct cfg80211_scan_request *scan_req;
 768
 769         /*
 770          * check if at least one STA interface is associated,
 771          * check if at least one STA interface has pending tx frames
 772          * and grab the lowest used beacon interval
 773          */
 774         mutex_lock(&local->iflist_mtx);
 775         list_for_each_entry(sdata, &local->interfaces, list) {
 776                 if (!ieee80211_sdata_running(sdata))
 777                         continue;
 778
 779                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 780                         if (sdata->u.mgd.associated) {
 781                                 associated = true;
 782
 783                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 784                                         tx_empty = false;
 785                                         break;
 786                                 }
 787                         }
 788                 }
 789         }
 790         mutex_unlock(&local->iflist_mtx);
 791
 792         scan_req = rcu_dereference_protected(local->scan_req,
 793                                              lockdep_is_held(&local->mtx));
 794
 795         next_chan = scan_req->channels[local->scan_channel_idx];
 796
 797         /*
 798          * we're currently scanning a different channel, let's
 799          * see if we can scan another channel without interfering
 800          * with the current traffic situation.
 801          *
 802          * Keep good latency, do not stay off-channel more than 125 ms.
 803          */
 804
 805         bad_latency = time_after(jiffies +
 806                                  ieee80211_scan_get_channel_time(next_chan),
 807                                  local->leave_oper_channel_time + HZ / 8);
 808
 809         if (associated && !tx_empty) {
 810                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 811                         next_scan_state = SCAN_ABORT;
 812                 else
 813                         next_scan_state = SCAN_SUSPEND;
 814         } else if (associated && bad_latency) {
 815                 next_scan_state = SCAN_SUSPEND;
 816         } else {
 817                 next_scan_state = SCAN_SET_CHANNEL;
 818         }
 819
 820         local->next_scan_state = next_scan_state;
 821
 822         *next_delay = 0;
 823 }
 824
 825 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 826                                              unsigned long *next_delay)
 827 {
 828         int skip;
 829         struct ieee80211_channel *chan;
 830         enum nl80211_bss_scan_width oper_scan_width;
 831         struct cfg80211_scan_request *scan_req;
 832
 833         scan_req = rcu_dereference_protected(local->scan_req,
 834                                              lockdep_is_held(&local->mtx));
 835
 836         skip = 0;
 837         chan = scan_req->channels[local->scan_channel_idx];
 838
 839         local->scan_chandef.chan = chan;
 840         local->scan_chandef.center_freq1 = chan->center_freq;
 841         local->scan_chandef.center_freq2 = 0;
 842         switch (scan_req->scan_width) {
 843         case NL80211_BSS_CHAN_WIDTH_5:
 844                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 845                 break;
 846         case NL80211_BSS_CHAN_WIDTH_10:
 847                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 848                 break;
 849         case NL80211_BSS_CHAN_WIDTH_20:
 850                 /* If scanning on oper channel, use whatever channel-type
 851                  * is currently in use.
 852                  */
 853                 oper_scan_width = cfg80211_chandef_to_scan_width(
 854                                         &local->_oper_chandef);
 855                 if (chan == local->_oper_chandef.chan &&
 856                     oper_scan_width == scan_req->scan_width)
 857                         local->scan_chandef = local->_oper_chandef;
 858                 else
 859                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 860                 break;
 861         }
 862
 863         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 864                 skip = 1;
 865
 866         /* advance state machine to next channel/band */
 867         local->scan_channel_idx++;
 868
 869         if (skip) {
 870                 /* if we skip this channel return to the decision state */
 871                 local->next_scan_state = SCAN_DECISION;
 872                 return;
 873         }
 874
 875         /*
 876          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 877          * (which unfortunately doesn't say _why_ step a) is done,
 878          * but it waits for the probe delay or until a frame is
 879          * received - and the received frame would update the NAV).
 880          * For now, we do not support waiting until a frame is
 881          * received.
 882          *
 883          * In any case, it is not necessary for a passive scan.
 884          */
 885         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 886             !scan_req->n_ssids) {
 887                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 888                 local->next_scan_state = SCAN_DECISION;
 889                 return;
 890         }
 891
 892         /* active scan, send probes */
 893         *next_delay = IEEE80211_PROBE_DELAY;
 894         local->next_scan_state = SCAN_SEND_PROBE;
 895 }
 896
 897 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 898                                          unsigned long *next_delay)
 899 {
 900         /* switch back to the operating channel */
 901         local->scan_chandef.chan = NULL;
 902         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 903
 904         /* disable PS */
 905         ieee80211_offchannel_return(local);
 906
 907         *next_delay = HZ / 5;
 908         /* afterwards, resume scan & go to next channel */
 909         local->next_scan_state = SCAN_RESUME;
 910 }
 911
 912 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
 913                                         unsigned long *next_delay)
 914 {
 915         ieee80211_offchannel_stop_vifs(local);
 916
 917         if (local->ops->flush) {
 918                 ieee80211_flush_queues(local, NULL, false);
 919                 *next_delay = 0;
 920         } else
 921                 *next_delay = HZ / 10;
 922
 923         /* remember when we left the operating channel */
 924         local->leave_oper_channel_time = jiffies;
 925
 926         /* advance to the next channel to be scanned */
 927         local->next_scan_state = SCAN_SET_CHANNEL;
 928 }
 929
 930 void ieee80211_scan_work(struct work_struct *work)
 931 {
 932         struct ieee80211_local *local =
 933                 container_of(work, struct ieee80211_local, scan_work.work);
 934         struct ieee80211_sub_if_data *sdata;
 935         struct cfg80211_scan_request *scan_req;
 936         unsigned long next_delay = 0;
 937         bool aborted;
 938
 939         mutex_lock(&local->mtx);
 940
 941         if (!ieee80211_can_run_worker(local)) {
 942                 aborted = true;
 943                 goto out_complete;
 944         }
 945
 946         sdata = rcu_dereference_protected(local->scan_sdata,
 947                                           lockdep_is_held(&local->mtx));
 948         scan_req = rcu_dereference_protected(local->scan_req,
 949                                              lockdep_is_held(&local->mtx));
 950
 951         /* When scanning on-channel, the first-callback means completed. */
 952         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
 953                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 954                 goto out_complete;
 955         }
 956
 957         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
 958                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 959                 goto out_complete;
 960         }
 961
 962         if (!sdata || !scan_req)
 963                 goto out;
 964
 965         if (!local->scanning) {
 966                 int rc;
 967
 968                 RCU_INIT_POINTER(local->scan_req, NULL);
 969                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 970
 971                 rc = __ieee80211_start_scan(sdata, scan_req);
 972                 if (rc) {
 973                         /* need to complete scan in cfg80211 */
 974                         rcu_assign_pointer(local->scan_req, scan_req);
 975                         aborted = true;
 976                         goto out_complete;
 977                 } else
 978                         goto out;
 979         }
 980
 981         /*
 982          * as long as no delay is required advance immediately
 983          * without scheduling a new work
 984          */
 985         do {
 986                 if (!ieee80211_sdata_running(sdata)) {
 987                         aborted = true;
 988                         goto out_complete;
 989                 }
 990
 991                 switch (local->next_scan_state) {
 992                 case SCAN_DECISION:
 993                         /* if no more bands/channels left, complete scan */
 994                         if (local->scan_channel_idx >= scan_req->n_channels) {
 995                                 aborted = false;
 996                                 goto out_complete;
 997                         }
 998                         ieee80211_scan_state_decision(local, &next_delay);
 999                         break;
1000                 case SCAN_SET_CHANNEL:
1001                         ieee80211_scan_state_set_channel(local, &next_delay);
1002                         break;
1003                 case SCAN_SEND_PROBE:
1004                         ieee80211_scan_state_send_probe(local, &next_delay);
1005                         break;
1006                 case SCAN_SUSPEND:
1007                         ieee80211_scan_state_suspend(local, &next_delay);
1008                         break;
1009                 case SCAN_RESUME:
1010                         ieee80211_scan_state_resume(local, &next_delay);
1011                         break;
1012                 case SCAN_ABORT:
1013                         aborted = true;
1014                         goto out_complete;
1015                 }
1016         } while (next_delay == 0);
1017
1018         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1019         goto out;
1020
1021 out_complete:
1022         __ieee80211_scan_completed(&local->hw, aborted);
1023 out:
1024         mutex_unlock(&local->mtx);
1025 }
1026
1027 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1028                            struct cfg80211_scan_request *req)
1029 {
1030         int res;
1031
1032         mutex_lock(&sdata->local->mtx);
1033         res = __ieee80211_start_scan(sdata, req);
1034         mutex_unlock(&sdata->local->mtx);
1035
1036         return res;
1037 }
1038
1039 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1040                                 const u8 *ssid, u8 ssid_len,
1041                                 struct ieee80211_channel **channels,
1042                                 unsigned int n_channels,
1043                                 enum nl80211_bss_scan_width scan_width)
1044 {
1045         struct ieee80211_local *local = sdata->local;
1046         int ret = -EBUSY, i, n_ch = 0;
1047         enum nl80211_band band;
1048
1049         mutex_lock(&local->mtx);
1050
1051         /* busy scanning */
1052         if (local->scan_req)
1053                 goto unlock;
1054
1055         /* fill internal scan request */
1056         if (!channels) {
1057                 int max_n;
1058
1059                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1060                         if (!local->hw.wiphy->bands[band])
1061                                 continue;
1062
1063                         max_n = local->hw.wiphy->bands[band]->n_channels;
1064                         for (i = 0; i < max_n; i++) {
1065                                 struct ieee80211_channel *tmp_ch =
1066                                     &local->hw.wiphy->bands[band]->channels[i];
1067
1068                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1069                                                      IEEE80211_CHAN_DISABLED))
1070                                         continue;
1071
1072                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1073                                 n_ch++;
1074                         }
1075                 }
1076
1077                 if (WARN_ON_ONCE(n_ch == 0))
1078                         goto unlock;
1079
1080                 local->int_scan_req->n_channels = n_ch;
1081         } else {
1082                 for (i = 0; i < n_channels; i++) {
1083                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1084                                                   IEEE80211_CHAN_DISABLED))
1085                                 continue;
1086
1087                         local->int_scan_req->channels[n_ch] = channels[i];
1088                         n_ch++;
1089                 }
1090
1091                 if (WARN_ON_ONCE(n_ch == 0))
1092                         goto unlock;
1093
1094                 local->int_scan_req->n_channels = n_ch;
1095         }
1096
1097         local->int_scan_req->ssids = &local->scan_ssid;
1098         local->int_scan_req->n_ssids = 1;
1099         local->int_scan_req->scan_width = scan_width;
1100         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1101         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1102
1103         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1104  unlock:
1105         mutex_unlock(&local->mtx);
1106         return ret;
1107 }
1108
1109 /*
1110  * Only call this function when a scan can't be queued -- under RTNL.
1111  */
1112 void ieee80211_scan_cancel(struct ieee80211_local *local)
1113 {
1114         /*
1115          * We are canceling software scan, or deferred scan that was not
1116          * yet really started (see __ieee80211_start_scan ).
1117          *
1118          * Regarding hardware scan:
1119          * - we can not call  __ieee80211_scan_completed() as when
1120          *   SCAN_HW_SCANNING bit is set this function change
1121          *   local->hw_scan_req to operate on 5G band, what race with
1122          *   driver which can use local->hw_scan_req
1123          *
1124          * - we can not cancel scan_work since driver can schedule it
1125          *   by ieee80211_scan_completed(..., true) to finish scan
1126          *
1127          * Hence we only call the cancel_hw_scan() callback, but the low-level
1128          * driver is still responsible for calling ieee80211_scan_completed()
1129          * after the scan was completed/aborted.
1130          */
1131
1132         mutex_lock(&local->mtx);
1133         if (!local->scan_req)
1134                 goto out;
1135
1136         /*
1137          * We have a scan running and the driver already reported completion,
1138          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1139          * cancelled.
1140          */
1141         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1142             test_bit(SCAN_COMPLETED, &local->scanning)) {
1143                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1144                 goto out;
1145         }
1146
1147         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1148                 /*
1149                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1150                  * scan on another band.
1151                  */
1152                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1153                 if (local->ops->cancel_hw_scan)
1154                         drv_cancel_hw_scan(local,
1155                                 rcu_dereference_protected(local->scan_sdata,
1156                                                 lockdep_is_held(&local->mtx)));
1157                 goto out;
1158         }
1159
1160         /*
1161          * If the work is currently running, it must be blocked on
1162          * the mutex, but we'll set scan_sdata = NULL and it'll
1163          * simply exit once it acquires the mutex.
1164          */
1165         cancel_delayed_work(&local->scan_work);
1166         /* and clean up */
1167         memset(&local->scan_info, 0, sizeof(local->scan_info));
1168         __ieee80211_scan_completed(&local->hw, true);
1169 out:
1170         mutex_unlock(&local->mtx);
1171 }
1172
1173 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1174                                         struct cfg80211_sched_scan_request *req)
1175 {
1176         struct ieee80211_local *local = sdata->local;
1177         struct ieee80211_scan_ies sched_scan_ies = {};
1178         struct cfg80211_chan_def chandef;
1179         int ret, i, iebufsz, num_bands = 0;
1180         u32 rate_masks[NUM_NL80211_BANDS] = {};
1181         u8 bands_used = 0;
1182         u8 *ie;
1183         u32 flags = 0;
1184
1185         iebufsz = local->scan_ies_len + req->ie_len;
1186
1187         lockdep_assert_held(&local->mtx);
1188
1189         if (!local->ops->sched_scan_start)
1190                 return -ENOTSUPP;
1191
1192         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1193                 if (local->hw.wiphy->bands[i]) {
1194                         bands_used |= BIT(i);
1195                         rate_masks[i] = (u32) -1;
1196                         num_bands++;
1197                 }
1198         }
1199
1200         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1201                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1202
1203         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1204         if (!ie) {
1205                 ret = -ENOMEM;
1206                 goto out;
1207         }
1208
1209         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1210
1211         ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1212                                  &sched_scan_ies, req->ie,
1213                                  req->ie_len, bands_used, rate_masks, &chandef,
1214                                  flags);
1215
1216         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1217         if (ret == 0) {
1218                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1219                 rcu_assign_pointer(local->sched_scan_req, req);
1220         }
1221
1222         kfree(ie);
1223
1224 out:
1225         if (ret) {
1226                 /* Clean in case of failure after HW restart or upon resume. */
1227                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1228                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1229         }
1230
1231         return ret;
1232 }
1233
1234 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1235                                        struct cfg80211_sched_scan_request *req)
1236 {
1237         struct ieee80211_local *local = sdata->local;
1238         int ret;
1239
1240         mutex_lock(&local->mtx);
1241
1242         if (rcu_access_pointer(local->sched_scan_sdata)) {
1243                 mutex_unlock(&local->mtx);
1244                 return -EBUSY;
1245         }
1246
1247         ret = __ieee80211_request_sched_scan_start(sdata, req);
1248
1249         mutex_unlock(&local->mtx);
1250         return ret;
1251 }
1252
1253 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1254 {
1255         struct ieee80211_sub_if_data *sched_scan_sdata;
1256         int ret = -ENOENT;
1257
1258         mutex_lock(&local->mtx);
1259
1260         if (!local->ops->sched_scan_stop) {
1261                 ret = -ENOTSUPP;
1262                 goto out;
1263         }
1264
1265         /* We don't want to restart sched scan anymore. */
1266         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1267
1268         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1269                                                 lockdep_is_held(&local->mtx));
1270         if (sched_scan_sdata) {
1271                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1272                 if (!ret)
1273                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1274         }
1275 out:
1276         mutex_unlock(&local->mtx);
1277
1278         return ret;
1279 }
1280
1281 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1282 {
1283         struct ieee80211_local *local = hw_to_local(hw);
1284
1285         trace_api_sched_scan_results(local);
1286
1287         cfg80211_sched_scan_results(hw->wiphy, 0);
1288 }
1289 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1290
1291 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1292 {
1293         mutex_lock(&local->mtx);
1294
1295         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1296                 mutex_unlock(&local->mtx);
1297                 return;
1298         }
1299
1300         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1301
1302         /* If sched scan was aborted by the driver. */
1303         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1304
1305         mutex_unlock(&local->mtx);
1306
1307         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1308 }
1309
1310 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1311 {
1312         struct ieee80211_local *local =
1313                 container_of(work, struct ieee80211_local,
1314                              sched_scan_stopped_work);
1315
1316         ieee80211_sched_scan_end(local);
1317 }
1318
1319 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1320 {
1321         struct ieee80211_local *local = hw_to_local(hw);
1322
1323         trace_api_sched_scan_stopped(local);
1324
1325         /*
1326          * this shouldn't really happen, so for simplicity
1327          * simply ignore it, and let mac80211 reconfigure
1328          * the sched scan later on.
1329          */
1330         if (local->in_reconfig)
1331                 return;
1332
1333         schedule_work(&local->sched_scan_stopped_work);
1334 }
1335 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);