net/mac80211/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Scanning implementation
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2004, Instant802 Networks, Inc.
   7  * Copyright 2005, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2013-2015  Intel Mobile Communications GmbH
  11  * Copyright 2016-2017  Intel Deutschland GmbH
  12  * Copyright (C) 2018-2019 Intel Corporation
  13  */
  14
  15 #include <linux/if_arp.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rtnetlink.h>
  18 #include <net/sch_generic.h>
  19 #include <linux/slab.h>
  20 #include <linux/export.h>
  21 #include <linux/random.h>
  22 #include <net/mac80211.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "mesh.h"
  27
  28 #define IEEE80211_PROBE_DELAY (HZ / 33)
  29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  31
  32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  33                           struct ieee80211_bss *bss)
  34 {
  35         if (!bss)
  36                 return;
  37         cfg80211_put_bss(local->hw.wiphy,
  38                          container_of((void *)bss, struct cfg80211_bss, priv));
  39 }
  40
  41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  42 {
  43         u8 qos_info;
  44
  45         if (elems->wmm_info && elems->wmm_info_len == 7
  46             && elems->wmm_info[5] == 1)
  47                 qos_info = elems->wmm_info[6];
  48         else if (elems->wmm_param && elems->wmm_param_len == 24
  49                  && elems->wmm_param[5] == 1)
  50                 qos_info = elems->wmm_param[6];
  51         else
  52                 /* no valid wmm information or parameter element found */
  53                 return false;
  54
  55         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  56 }
  57
  58 static void
  59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
  60                                 struct ieee80211_bss *bss,
  61                                 struct ieee802_11_elems *elems,
  62                                 struct ieee80211_rx_status *rx_status,
  63                                 bool beacon)
  64 {
  65         int clen, srlen;
  66
  67         if (beacon)
  68                 bss->device_ts_beacon = rx_status->device_timestamp;
  69         else
  70                 bss->device_ts_presp = rx_status->device_timestamp;
  71
  72         if (elems->parse_error) {
  73                 if (beacon)
  74                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
  75                 else
  76                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
  77         } else {
  78                 if (beacon)
  79                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
  80                 else
  81                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
  82         }
  83
  84         /* save the ERP value so that it is available at association time */
  85         if (elems->erp_info && (!elems->parse_error ||
  86                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
  87                 bss->erp_value = elems->erp_info[0];
  88                 bss->has_erp_value = true;
  89                 if (!elems->parse_error)
  90                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
  91         }
  92
  93         /* replace old supported rates if we get new values */
  94         if (!elems->parse_error ||
  95             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
  96                 srlen = 0;
  97                 if (elems->supp_rates) {
  98                         clen = IEEE80211_MAX_SUPP_RATES;
  99                         if (clen > elems->supp_rates_len)
 100                                 clen = elems->supp_rates_len;
 101                         memcpy(bss->supp_rates, elems->supp_rates, clen);
 102                         srlen += clen;
 103                 }
 104                 if (elems->ext_supp_rates) {
 105                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 106                         if (clen > elems->ext_supp_rates_len)
 107                                 clen = elems->ext_supp_rates_len;
 108                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 109                                clen);
 110                         srlen += clen;
 111                 }
 112                 if (srlen) {
 113                         bss->supp_rates_len = srlen;
 114                         if (!elems->parse_error)
 115                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 116                 }
 117         }
 118
 119         if (!elems->parse_error ||
 120             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 121                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
 122                 bss->uapsd_supported = is_uapsd_supported(elems);
 123                 if (!elems->parse_error)
 124                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 125         }
 126
 127         if (beacon) {
 128                 struct ieee80211_supported_band *sband =
 129                         local->hw.wiphy->bands[rx_status->band];
 130                 if (!(rx_status->encoding == RX_ENC_HT) &&
 131                     !(rx_status->encoding == RX_ENC_VHT))
 132                         bss->beacon_rate =
 133                                 &sband->bitrates[rx_status->rate_idx];
 134         }
 135 }
 136
 137 struct ieee80211_bss *
 138 ieee80211_bss_info_update(struct ieee80211_local *local,
 139                           struct ieee80211_rx_status *rx_status,
 140                           struct ieee80211_mgmt *mgmt, size_t len,
 141                           struct ieee80211_channel *channel)
 142 {
 143         bool beacon = ieee80211_is_beacon(mgmt->frame_control);
 144         struct cfg80211_bss *cbss, *non_tx_cbss;
 145         struct ieee80211_bss *bss, *non_tx_bss;
 146         struct cfg80211_inform_bss bss_meta = {
 147                 .boottime_ns = rx_status->boottime_ns,
 148         };
 149         bool signal_valid;
 150         struct ieee80211_sub_if_data *scan_sdata;
 151         struct ieee802_11_elems elems;
 152         size_t baselen;
 153         u8 *elements;
 154
 155         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
 156                 bss_meta.signal = 0; /* invalid signal indication */
 157         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
 158                 bss_meta.signal = rx_status->signal * 100;
 159         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
 160                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
 161
 162         bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
 163         if (rx_status->bw == RATE_INFO_BW_5)
 164                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
 165         else if (rx_status->bw == RATE_INFO_BW_10)
 166                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
 167
 168         bss_meta.chan = channel;
 169
 170         rcu_read_lock();
 171         scan_sdata = rcu_dereference(local->scan_sdata);
 172         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
 173             scan_sdata->vif.bss_conf.assoc &&
 174             ieee80211_have_rx_timestamp(rx_status)) {
 175                 bss_meta.parent_tsf =
 176                         ieee80211_calculate_rx_timestamp(local, rx_status,
 177                                                          len + FCS_LEN, 24);
 178                 ether_addr_copy(bss_meta.parent_bssid,
 179                                 scan_sdata->vif.bss_conf.bssid);
 180         }
 181         rcu_read_unlock();
 182
 183         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 184                                               mgmt, len, GFP_ATOMIC);
 185         if (!cbss)
 186                 return NULL;
 187
 188         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 189                 elements = mgmt->u.probe_resp.variable;
 190                 baselen = offsetof(struct ieee80211_mgmt,
 191                                    u.probe_resp.variable);
 192         } else {
 193                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 194                 elements = mgmt->u.beacon.variable;
 195         }
 196
 197         if (baselen > len)
 198                 return NULL;
 199
 200         ieee802_11_parse_elems(elements, len - baselen, false, &elems,
 201                                mgmt->bssid, cbss->bssid);
 202
 203         /* In case the signal is invalid update the status */
 204         signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
 205                 <= local->hw.wiphy->max_adj_channel_rssi_comp;
 206         if (!signal_valid)
 207                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 208
 209         bss = (void *)cbss->priv;
 210         ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
 211
 212         list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
 213                 non_tx_bss = (void *)non_tx_cbss->priv;
 214
 215                 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
 216                                                 rx_status, beacon);
 217         }
 218
 219         return bss;
 220 }
 221
 222 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 223                                         u32 scan_flags, const u8 *da)
 224 {
 225         if (!sdata)
 226                 return false;
 227         /* accept broadcast for OCE */
 228         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 229             is_broadcast_ether_addr(da))
 230                 return true;
 231         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 232                 return true;
 233         return ether_addr_equal(da, sdata->vif.addr);
 234 }
 235
 236 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 237 {
 238         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 239         struct ieee80211_sub_if_data *sdata1, *sdata2;
 240         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 241         struct ieee80211_bss *bss;
 242         struct ieee80211_channel *channel;
 243
 244         if (skb->len < 24 ||
 245             (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 246              !ieee80211_is_beacon(mgmt->frame_control)))
 247                 return;
 248
 249         sdata1 = rcu_dereference(local->scan_sdata);
 250         sdata2 = rcu_dereference(local->sched_scan_sdata);
 251
 252         if (likely(!sdata1 && !sdata2))
 253                 return;
 254
 255         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 256                 struct cfg80211_scan_request *scan_req;
 257                 struct cfg80211_sched_scan_request *sched_scan_req;
 258                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 259
 260                 scan_req = rcu_dereference(local->scan_req);
 261                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 262
 263                 if (scan_req)
 264                         scan_req_flags = scan_req->flags;
 265
 266                 if (sched_scan_req)
 267                         sched_scan_req_flags = sched_scan_req->flags;
 268
 269                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 270                  * unless scanning with randomised address
 271                  */
 272                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 273                                                  mgmt->da) &&
 274                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 275                                                  mgmt->da))
 276                         return;
 277         }
 278
 279         channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
 280
 281         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 282                 return;
 283
 284         bss = ieee80211_bss_info_update(local, rx_status,
 285                                         mgmt, skb->len,
 286                                         channel);
 287         if (bss)
 288                 ieee80211_rx_bss_put(local, bss);
 289 }
 290
 291 static void
 292 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 293                                enum nl80211_bss_scan_width scan_width)
 294 {
 295         memset(chandef, 0, sizeof(*chandef));
 296         switch (scan_width) {
 297         case NL80211_BSS_CHAN_WIDTH_5:
 298                 chandef->width = NL80211_CHAN_WIDTH_5;
 299                 break;
 300         case NL80211_BSS_CHAN_WIDTH_10:
 301                 chandef->width = NL80211_CHAN_WIDTH_10;
 302                 break;
 303         default:
 304                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 305                 break;
 306         }
 307 }
 308
 309 /* return false if no more work */
 310 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 311 {
 312         struct cfg80211_scan_request *req;
 313         struct cfg80211_chan_def chandef;
 314         u8 bands_used = 0;
 315         int i, ielen, n_chans;
 316         u32 flags = 0;
 317
 318         req = rcu_dereference_protected(local->scan_req,
 319                                         lockdep_is_held(&local->mtx));
 320
 321         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 322                 return false;
 323
 324         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 325                 for (i = 0; i < req->n_channels; i++) {
 326                         local->hw_scan_req->req.channels[i] = req->channels[i];
 327                         bands_used |= BIT(req->channels[i]->band);
 328                 }
 329
 330                 n_chans = req->n_channels;
 331         } else {
 332                 do {
 333                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 334                                 return false;
 335
 336                         n_chans = 0;
 337
 338                         for (i = 0; i < req->n_channels; i++) {
 339                                 if (req->channels[i]->band !=
 340                                     local->hw_scan_band)
 341                                         continue;
 342                                 local->hw_scan_req->req.channels[n_chans] =
 343                                                         req->channels[i];
 344                                 n_chans++;
 345                                 bands_used |= BIT(req->channels[i]->band);
 346                         }
 347
 348                         local->hw_scan_band++;
 349                 } while (!n_chans);
 350         }
 351
 352         local->hw_scan_req->req.n_channels = n_chans;
 353         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 354
 355         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 356                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 357
 358         ielen = ieee80211_build_preq_ies(local,
 359                                          (u8 *)local->hw_scan_req->req.ie,
 360                                          local->hw_scan_ies_bufsize,
 361                                          &local->hw_scan_req->ies,
 362                                          req->ie, req->ie_len,
 363                                          bands_used, req->rates, &chandef,
 364                                          flags);
 365         local->hw_scan_req->req.ie_len = ielen;
 366         local->hw_scan_req->req.no_cck = req->no_cck;
 367         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 368         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 369                         req->mac_addr_mask);
 370         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 371
 372         return true;
 373 }
 374
 375 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 376 {
 377         struct ieee80211_local *local = hw_to_local(hw);
 378         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 379         bool was_scanning = local->scanning;
 380         struct cfg80211_scan_request *scan_req;
 381         struct ieee80211_sub_if_data *scan_sdata;
 382         struct ieee80211_sub_if_data *sdata;
 383
 384         lockdep_assert_held(&local->mtx);
 385
 386         /*
 387          * It's ok to abort a not-yet-running scan (that
 388          * we have one at all will be verified by checking
 389          * local->scan_req next), but not to complete it
 390          * successfully.
 391          */
 392         if (WARN_ON(!local->scanning && !aborted))
 393                 aborted = true;
 394
 395         if (WARN_ON(!local->scan_req))
 396                 return;
 397
 398         if (hw_scan && !aborted &&
 399             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 400             ieee80211_prep_hw_scan(local)) {
 401                 int rc;
 402
 403                 rc = drv_hw_scan(local,
 404                         rcu_dereference_protected(local->scan_sdata,
 405                                                   lockdep_is_held(&local->mtx)),
 406                         local->hw_scan_req);
 407
 408                 if (rc == 0)
 409                         return;
 410
 411                 /* HW scan failed and is going to be reported as aborted,
 412                  * so clear old scan info.
 413                  */
 414                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 415                 aborted = true;
 416         }
 417
 418         kfree(local->hw_scan_req);
 419         local->hw_scan_req = NULL;
 420
 421         scan_req = rcu_dereference_protected(local->scan_req,
 422                                              lockdep_is_held(&local->mtx));
 423
 424         if (scan_req != local->int_scan_req) {
 425                 local->scan_info.aborted = aborted;
 426                 cfg80211_scan_done(scan_req, &local->scan_info);
 427         }
 428         RCU_INIT_POINTER(local->scan_req, NULL);
 429
 430         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 431                                                lockdep_is_held(&local->mtx));
 432         RCU_INIT_POINTER(local->scan_sdata, NULL);
 433
 434         local->scanning = 0;
 435         local->scan_chandef.chan = NULL;
 436
 437         /* Set power back to normal operating levels. */
 438         ieee80211_hw_config(local, 0);
 439
 440         if (!hw_scan) {
 441                 ieee80211_configure_filter(local);
 442                 drv_sw_scan_complete(local, scan_sdata);
 443                 ieee80211_offchannel_return(local);
 444         }
 445
 446         ieee80211_recalc_idle(local);
 447
 448         ieee80211_mlme_notify_scan_completed(local);
 449         ieee80211_ibss_notify_scan_completed(local);
 450
 451         /* Requeue all the work that might have been ignored while
 452          * the scan was in progress; if there was none this will
 453          * just be a no-op for the particular interface.
 454          */
 455         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 456                 if (ieee80211_sdata_running(sdata))
 457                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 458         }
 459
 460         if (was_scanning)
 461                 ieee80211_start_next_roc(local);
 462 }
 463
 464 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 465                               struct cfg80211_scan_info *info)
 466 {
 467         struct ieee80211_local *local = hw_to_local(hw);
 468
 469         trace_api_scan_completed(local, info->aborted);
 470
 471         set_bit(SCAN_COMPLETED, &local->scanning);
 472         if (info->aborted)
 473                 set_bit(SCAN_ABORTED, &local->scanning);
 474
 475         memcpy(&local->scan_info, info, sizeof(*info));
 476
 477         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 478 }
 479 EXPORT_SYMBOL(ieee80211_scan_completed);
 480
 481 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 482                                    struct ieee80211_sub_if_data *sdata)
 483 {
 484         /* Software scan is not supported in multi-channel cases */
 485         if (local->use_chanctx)
 486                 return -EOPNOTSUPP;
 487
 488         /*
 489          * Hardware/driver doesn't support hw_scan, so use software
 490          * scanning instead. First send a nullfunc frame with power save
 491          * bit on so that AP will buffer the frames for us while we are not
 492          * listening, then send probe requests to each channel and wait for
 493          * the responses. After all channels are scanned, tune back to the
 494          * original channel and send a nullfunc frame with power save bit
 495          * off to trigger the AP to send us all the buffered frames.
 496          *
 497          * Note that while local->sw_scanning is true everything else but
 498          * nullfunc frames and probe requests will be dropped in
 499          * ieee80211_tx_h_check_assoc().
 500          */
 501         drv_sw_scan_start(local, sdata, local->scan_addr);
 502
 503         local->leave_oper_channel_time = jiffies;
 504         local->next_scan_state = SCAN_DECISION;
 505         local->scan_channel_idx = 0;
 506
 507         ieee80211_offchannel_stop_vifs(local);
 508
 509         /* ensure nullfunc is transmitted before leaving operating channel */
 510         ieee80211_flush_queues(local, NULL, false);
 511
 512         ieee80211_configure_filter(local);
 513
 514         /* We need to set power level at maximum rate for scanning. */
 515         ieee80211_hw_config(local, 0);
 516
 517         ieee80211_queue_delayed_work(&local->hw,
 518                                      &local->scan_work, 0);
 519
 520         return 0;
 521 }
 522
 523 static bool ieee80211_can_scan(struct ieee80211_local *local,
 524                                struct ieee80211_sub_if_data *sdata)
 525 {
 526         if (ieee80211_is_radar_required(local))
 527                 return false;
 528
 529         if (!list_empty(&local->roc_list))
 530                 return false;
 531
 532         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 533             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 534                 return false;
 535
 536         return true;
 537 }
 538
 539 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 540 {
 541         lockdep_assert_held(&local->mtx);
 542
 543         if (!local->scan_req || local->scanning)
 544                 return;
 545
 546         if (!ieee80211_can_scan(local,
 547                                 rcu_dereference_protected(
 548                                         local->scan_sdata,
 549                                         lockdep_is_held(&local->mtx))))
 550                 return;
 551
 552         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 553                                      round_jiffies_relative(0));
 554 }
 555
 556 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 557                                           const u8 *src, const u8 *dst,
 558                                           const u8 *ssid, size_t ssid_len,
 559                                           const u8 *ie, size_t ie_len,
 560                                           u32 ratemask, u32 flags, u32 tx_flags,
 561                                           struct ieee80211_channel *channel)
 562 {
 563         struct sk_buff *skb;
 564         u32 txdata_flags = 0;
 565
 566         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 567                                         ssid, ssid_len,
 568                                         ie, ie_len, flags);
 569
 570         if (skb) {
 571                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 572                         struct ieee80211_hdr *hdr = (void *)skb->data;
 573                         u16 sn = get_random_u32();
 574
 575                         txdata_flags |= IEEE80211_TX_NO_SEQNO;
 576                         hdr->seq_ctrl =
 577                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 578                 }
 579                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 580                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
 581                                           txdata_flags);
 582         }
 583 }
 584
 585 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 586                                             unsigned long *next_delay)
 587 {
 588         int i;
 589         struct ieee80211_sub_if_data *sdata;
 590         struct cfg80211_scan_request *scan_req;
 591         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 592         u32 flags = 0, tx_flags;
 593
 594         scan_req = rcu_dereference_protected(local->scan_req,
 595                                              lockdep_is_held(&local->mtx));
 596
 597         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 598         if (scan_req->no_cck)
 599                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 600         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 601                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 602         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 603                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 604
 605         sdata = rcu_dereference_protected(local->scan_sdata,
 606                                           lockdep_is_held(&local->mtx));
 607
 608         for (i = 0; i < scan_req->n_ssids; i++)
 609                 ieee80211_send_scan_probe_req(
 610                         sdata, local->scan_addr, scan_req->bssid,
 611                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 612                         scan_req->ie, scan_req->ie_len,
 613                         scan_req->rates[band], flags,
 614                         tx_flags, local->hw.conf.chandef.chan);
 615
 616         /*
 617          * After sending probe requests, wait for probe responses
 618          * on the channel.
 619          */
 620         *next_delay = IEEE80211_CHANNEL_TIME;
 621         local->next_scan_state = SCAN_DECISION;
 622 }
 623
 624 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 625                                   struct cfg80211_scan_request *req)
 626 {
 627         struct ieee80211_local *local = sdata->local;
 628         bool hw_scan = local->ops->hw_scan;
 629         int rc;
 630
 631         lockdep_assert_held(&local->mtx);
 632
 633         if (local->scan_req || ieee80211_is_radar_required(local))
 634                 return -EBUSY;
 635
 636         if (!ieee80211_can_scan(local, sdata)) {
 637                 /* wait for the work to finish/time out */
 638                 rcu_assign_pointer(local->scan_req, req);
 639                 rcu_assign_pointer(local->scan_sdata, sdata);
 640                 return 0;
 641         }
 642
 643  again:
 644         if (hw_scan) {
 645                 u8 *ies;
 646
 647                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 648
 649                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 650                         int i, n_bands = 0;
 651                         u8 bands_counted = 0;
 652
 653                         for (i = 0; i < req->n_channels; i++) {
 654                                 if (bands_counted & BIT(req->channels[i]->band))
 655                                         continue;
 656                                 bands_counted |= BIT(req->channels[i]->band);
 657                                 n_bands++;
 658                         }
 659
 660                         local->hw_scan_ies_bufsize *= n_bands;
 661                 }
 662
 663                 local->hw_scan_req = kmalloc(
 664                                 sizeof(*local->hw_scan_req) +
 665                                 req->n_channels * sizeof(req->channels[0]) +
 666                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 667                 if (!local->hw_scan_req)
 668                         return -ENOMEM;
 669
 670                 local->hw_scan_req->req.ssids = req->ssids;
 671                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 672                 ies = (u8 *)local->hw_scan_req +
 673                         sizeof(*local->hw_scan_req) +
 674                         req->n_channels * sizeof(req->channels[0]);
 675                 local->hw_scan_req->req.ie = ies;
 676                 local->hw_scan_req->req.flags = req->flags;
 677                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 678                 local->hw_scan_req->req.duration = req->duration;
 679                 local->hw_scan_req->req.duration_mandatory =
 680                         req->duration_mandatory;
 681
 682                 local->hw_scan_band = 0;
 683
 684                 /*
 685                  * After allocating local->hw_scan_req, we must
 686                  * go through until ieee80211_prep_hw_scan(), so
 687                  * anything that might be changed here and leave
 688                  * this function early must not go after this
 689                  * allocation.
 690                  */
 691         }
 692
 693         rcu_assign_pointer(local->scan_req, req);
 694         rcu_assign_pointer(local->scan_sdata, sdata);
 695
 696         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 697                 get_random_mask_addr(local->scan_addr,
 698                                      req->mac_addr,
 699                                      req->mac_addr_mask);
 700         else
 701                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 702
 703         if (hw_scan) {
 704                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 705         } else if ((req->n_channels == 1) &&
 706                    (req->channels[0] == local->_oper_chandef.chan)) {
 707                 /*
 708                  * If we are scanning only on the operating channel
 709                  * then we do not need to stop normal activities
 710                  */
 711                 unsigned long next_delay;
 712
 713                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 714
 715                 ieee80211_recalc_idle(local);
 716
 717                 /* Notify driver scan is starting, keep order of operations
 718                  * same as normal software scan, in case that matters. */
 719                 drv_sw_scan_start(local, sdata, local->scan_addr);
 720
 721                 ieee80211_configure_filter(local); /* accept probe-responses */
 722
 723                 /* We need to ensure power level is at max for scanning. */
 724                 ieee80211_hw_config(local, 0);
 725
 726                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 727                                                 IEEE80211_CHAN_RADAR)) ||
 728                     !req->n_ssids) {
 729                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 730                 } else {
 731                         ieee80211_scan_state_send_probe(local, &next_delay);
 732                         next_delay = IEEE80211_CHANNEL_TIME;
 733                 }
 734
 735                 /* Now, just wait a bit and we are all done! */
 736                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 737                                              next_delay);
 738                 return 0;
 739         } else {
 740                 /* Do normal software scan */
 741                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 742         }
 743
 744         ieee80211_recalc_idle(local);
 745
 746         if (hw_scan) {
 747                 WARN_ON(!ieee80211_prep_hw_scan(local));
 748                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 749         } else {
 750                 rc = ieee80211_start_sw_scan(local, sdata);
 751         }
 752
 753         if (rc) {
 754                 kfree(local->hw_scan_req);
 755                 local->hw_scan_req = NULL;
 756                 local->scanning = 0;
 757
 758                 ieee80211_recalc_idle(local);
 759
 760                 local->scan_req = NULL;
 761                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 762         }
 763
 764         if (hw_scan && rc == 1) {
 765                 /*
 766                  * we can't fall back to software for P2P-GO
 767                  * as it must update NoA etc.
 768                  */
 769                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 770                                 NL80211_IFTYPE_P2P_GO)
 771                         return -EOPNOTSUPP;
 772                 hw_scan = false;
 773                 goto again;
 774         }
 775
 776         return rc;
 777 }
 778
 779 static unsigned long
 780 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 781 {
 782         /*
 783          * TODO: channel switching also consumes quite some time,
 784          * add that delay as well to get a better estimation
 785          */
 786         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 787                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 788         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 789 }
 790
 791 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 792                                           unsigned long *next_delay)
 793 {
 794         bool associated = false;
 795         bool tx_empty = true;
 796         bool bad_latency;
 797         struct ieee80211_sub_if_data *sdata;
 798         struct ieee80211_channel *next_chan;
 799         enum mac80211_scan_state next_scan_state;
 800         struct cfg80211_scan_request *scan_req;
 801
 802         /*
 803          * check if at least one STA interface is associated,
 804          * check if at least one STA interface has pending tx frames
 805          * and grab the lowest used beacon interval
 806          */
 807         mutex_lock(&local->iflist_mtx);
 808         list_for_each_entry(sdata, &local->interfaces, list) {
 809                 if (!ieee80211_sdata_running(sdata))
 810                         continue;
 811
 812                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 813                         if (sdata->u.mgd.associated) {
 814                                 associated = true;
 815
 816                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 817                                         tx_empty = false;
 818                                         break;
 819                                 }
 820                         }
 821                 }
 822         }
 823         mutex_unlock(&local->iflist_mtx);
 824
 825         scan_req = rcu_dereference_protected(local->scan_req,
 826                                              lockdep_is_held(&local->mtx));
 827
 828         next_chan = scan_req->channels[local->scan_channel_idx];
 829
 830         /*
 831          * we're currently scanning a different channel, let's
 832          * see if we can scan another channel without interfering
 833          * with the current traffic situation.
 834          *
 835          * Keep good latency, do not stay off-channel more than 125 ms.
 836          */
 837
 838         bad_latency = time_after(jiffies +
 839                                  ieee80211_scan_get_channel_time(next_chan),
 840                                  local->leave_oper_channel_time + HZ / 8);
 841
 842         if (associated && !tx_empty) {
 843                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 844                         next_scan_state = SCAN_ABORT;
 845                 else
 846                         next_scan_state = SCAN_SUSPEND;
 847         } else if (associated && bad_latency) {
 848                 next_scan_state = SCAN_SUSPEND;
 849         } else {
 850                 next_scan_state = SCAN_SET_CHANNEL;
 851         }
 852
 853         local->next_scan_state = next_scan_state;
 854
 855         *next_delay = 0;
 856 }
 857
 858 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 859                                              unsigned long *next_delay)
 860 {
 861         int skip;
 862         struct ieee80211_channel *chan;
 863         enum nl80211_bss_scan_width oper_scan_width;
 864         struct cfg80211_scan_request *scan_req;
 865
 866         scan_req = rcu_dereference_protected(local->scan_req,
 867                                              lockdep_is_held(&local->mtx));
 868
 869         skip = 0;
 870         chan = scan_req->channels[local->scan_channel_idx];
 871
 872         local->scan_chandef.chan = chan;
 873         local->scan_chandef.center_freq1 = chan->center_freq;
 874         local->scan_chandef.center_freq2 = 0;
 875         switch (scan_req->scan_width) {
 876         case NL80211_BSS_CHAN_WIDTH_5:
 877                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 878                 break;
 879         case NL80211_BSS_CHAN_WIDTH_10:
 880                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 881                 break;
 882         case NL80211_BSS_CHAN_WIDTH_20:
 883                 /* If scanning on oper channel, use whatever channel-type
 884                  * is currently in use.
 885                  */
 886                 oper_scan_width = cfg80211_chandef_to_scan_width(
 887                                         &local->_oper_chandef);
 888                 if (chan == local->_oper_chandef.chan &&
 889                     oper_scan_width == scan_req->scan_width)
 890                         local->scan_chandef = local->_oper_chandef;
 891                 else
 892                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 893                 break;
 894         }
 895
 896         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 897                 skip = 1;
 898
 899         /* advance state machine to next channel/band */
 900         local->scan_channel_idx++;
 901
 902         if (skip) {
 903                 /* if we skip this channel return to the decision state */
 904                 local->next_scan_state = SCAN_DECISION;
 905                 return;
 906         }
 907
 908         /*
 909          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 910          * (which unfortunately doesn't say _why_ step a) is done,
 911          * but it waits for the probe delay or until a frame is
 912          * received - and the received frame would update the NAV).
 913          * For now, we do not support waiting until a frame is
 914          * received.
 915          *
 916          * In any case, it is not necessary for a passive scan.
 917          */
 918         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 919             !scan_req->n_ssids) {
 920                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 921                 local->next_scan_state = SCAN_DECISION;
 922                 return;
 923         }
 924
 925         /* active scan, send probes */
 926         *next_delay = IEEE80211_PROBE_DELAY;
 927         local->next_scan_state = SCAN_SEND_PROBE;
 928 }
 929
 930 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 931                                          unsigned long *next_delay)
 932 {
 933         /* switch back to the operating channel */
 934         local->scan_chandef.chan = NULL;
 935         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 936
 937         /* disable PS */
 938         ieee80211_offchannel_return(local);
 939
 940         *next_delay = HZ / 5;
 941         /* afterwards, resume scan & go to next channel */
 942         local->next_scan_state = SCAN_RESUME;
 943 }
 944
 945 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
 946                                         unsigned long *next_delay)
 947 {
 948         ieee80211_offchannel_stop_vifs(local);
 949
 950         if (local->ops->flush) {
 951                 ieee80211_flush_queues(local, NULL, false);
 952                 *next_delay = 0;
 953         } else
 954                 *next_delay = HZ / 10;
 955
 956         /* remember when we left the operating channel */
 957         local->leave_oper_channel_time = jiffies;
 958
 959         /* advance to the next channel to be scanned */
 960         local->next_scan_state = SCAN_SET_CHANNEL;
 961 }
 962
 963 void ieee80211_scan_work(struct work_struct *work)
 964 {
 965         struct ieee80211_local *local =
 966                 container_of(work, struct ieee80211_local, scan_work.work);
 967         struct ieee80211_sub_if_data *sdata;
 968         struct cfg80211_scan_request *scan_req;
 969         unsigned long next_delay = 0;
 970         bool aborted;
 971
 972         mutex_lock(&local->mtx);
 973
 974         if (!ieee80211_can_run_worker(local)) {
 975                 aborted = true;
 976                 goto out_complete;
 977         }
 978
 979         sdata = rcu_dereference_protected(local->scan_sdata,
 980                                           lockdep_is_held(&local->mtx));
 981         scan_req = rcu_dereference_protected(local->scan_req,
 982                                              lockdep_is_held(&local->mtx));
 983
 984         /* When scanning on-channel, the first-callback means completed. */
 985         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
 986                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 987                 goto out_complete;
 988         }
 989
 990         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
 991                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 992                 goto out_complete;
 993         }
 994
 995         if (!sdata || !scan_req)
 996                 goto out;
 997
 998         if (!local->scanning) {
 999                 int rc;
1000
1001                 RCU_INIT_POINTER(local->scan_req, NULL);
1002                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1003
1004                 rc = __ieee80211_start_scan(sdata, scan_req);
1005                 if (rc) {
1006                         /* need to complete scan in cfg80211 */
1007                         rcu_assign_pointer(local->scan_req, scan_req);
1008                         aborted = true;
1009                         goto out_complete;
1010                 } else
1011                         goto out;
1012         }
1013
1014         /*
1015          * as long as no delay is required advance immediately
1016          * without scheduling a new work
1017          */
1018         do {
1019                 if (!ieee80211_sdata_running(sdata)) {
1020                         aborted = true;
1021                         goto out_complete;
1022                 }
1023
1024                 switch (local->next_scan_state) {
1025                 case SCAN_DECISION:
1026                         /* if no more bands/channels left, complete scan */
1027                         if (local->scan_channel_idx >= scan_req->n_channels) {
1028                                 aborted = false;
1029                                 goto out_complete;
1030                         }
1031                         ieee80211_scan_state_decision(local, &next_delay);
1032                         break;
1033                 case SCAN_SET_CHANNEL:
1034                         ieee80211_scan_state_set_channel(local, &next_delay);
1035                         break;
1036                 case SCAN_SEND_PROBE:
1037                         ieee80211_scan_state_send_probe(local, &next_delay);
1038                         break;
1039                 case SCAN_SUSPEND:
1040                         ieee80211_scan_state_suspend(local, &next_delay);
1041                         break;
1042                 case SCAN_RESUME:
1043                         ieee80211_scan_state_resume(local, &next_delay);
1044                         break;
1045                 case SCAN_ABORT:
1046                         aborted = true;
1047                         goto out_complete;
1048                 }
1049         } while (next_delay == 0);
1050
1051         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1052         goto out;
1053
1054 out_complete:
1055         __ieee80211_scan_completed(&local->hw, aborted);
1056 out:
1057         mutex_unlock(&local->mtx);
1058 }
1059
1060 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1061                            struct cfg80211_scan_request *req)
1062 {
1063         int res;
1064
1065         mutex_lock(&sdata->local->mtx);
1066         res = __ieee80211_start_scan(sdata, req);
1067         mutex_unlock(&sdata->local->mtx);
1068
1069         return res;
1070 }
1071
1072 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1073                                 const u8 *ssid, u8 ssid_len,
1074                                 struct ieee80211_channel **channels,
1075                                 unsigned int n_channels,
1076                                 enum nl80211_bss_scan_width scan_width)
1077 {
1078         struct ieee80211_local *local = sdata->local;
1079         int ret = -EBUSY, i, n_ch = 0;
1080         enum nl80211_band band;
1081
1082         mutex_lock(&local->mtx);
1083
1084         /* busy scanning */
1085         if (local->scan_req)
1086                 goto unlock;
1087
1088         /* fill internal scan request */
1089         if (!channels) {
1090                 int max_n;
1091
1092                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1093                         if (!local->hw.wiphy->bands[band])
1094                                 continue;
1095
1096                         max_n = local->hw.wiphy->bands[band]->n_channels;
1097                         for (i = 0; i < max_n; i++) {
1098                                 struct ieee80211_channel *tmp_ch =
1099                                     &local->hw.wiphy->bands[band]->channels[i];
1100
1101                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1102                                                      IEEE80211_CHAN_DISABLED))
1103                                         continue;
1104
1105                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1106                                 n_ch++;
1107                         }
1108                 }
1109
1110                 if (WARN_ON_ONCE(n_ch == 0))
1111                         goto unlock;
1112
1113                 local->int_scan_req->n_channels = n_ch;
1114         } else {
1115                 for (i = 0; i < n_channels; i++) {
1116                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1117                                                   IEEE80211_CHAN_DISABLED))
1118                                 continue;
1119
1120                         local->int_scan_req->channels[n_ch] = channels[i];
1121                         n_ch++;
1122                 }
1123
1124                 if (WARN_ON_ONCE(n_ch == 0))
1125                         goto unlock;
1126
1127                 local->int_scan_req->n_channels = n_ch;
1128         }
1129
1130         local->int_scan_req->ssids = &local->scan_ssid;
1131         local->int_scan_req->n_ssids = 1;
1132         local->int_scan_req->scan_width = scan_width;
1133         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1134         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1135
1136         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1137  unlock:
1138         mutex_unlock(&local->mtx);
1139         return ret;
1140 }
1141
1142 /*
1143  * Only call this function when a scan can't be queued -- under RTNL.
1144  */
1145 void ieee80211_scan_cancel(struct ieee80211_local *local)
1146 {
1147         /*
1148          * We are canceling software scan, or deferred scan that was not
1149          * yet really started (see __ieee80211_start_scan ).
1150          *
1151          * Regarding hardware scan:
1152          * - we can not call  __ieee80211_scan_completed() as when
1153          *   SCAN_HW_SCANNING bit is set this function change
1154          *   local->hw_scan_req to operate on 5G band, what race with
1155          *   driver which can use local->hw_scan_req
1156          *
1157          * - we can not cancel scan_work since driver can schedule it
1158          *   by ieee80211_scan_completed(..., true) to finish scan
1159          *
1160          * Hence we only call the cancel_hw_scan() callback, but the low-level
1161          * driver is still responsible for calling ieee80211_scan_completed()
1162          * after the scan was completed/aborted.
1163          */
1164
1165         mutex_lock(&local->mtx);
1166         if (!local->scan_req)
1167                 goto out;
1168
1169         /*
1170          * We have a scan running and the driver already reported completion,
1171          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1172          * cancelled.
1173          */
1174         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1175             test_bit(SCAN_COMPLETED, &local->scanning)) {
1176                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1177                 goto out;
1178         }
1179
1180         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1181                 /*
1182                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1183                  * scan on another band.
1184                  */
1185                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1186                 if (local->ops->cancel_hw_scan)
1187                         drv_cancel_hw_scan(local,
1188                                 rcu_dereference_protected(local->scan_sdata,
1189                                                 lockdep_is_held(&local->mtx)));
1190                 goto out;
1191         }
1192
1193         /*
1194          * If the work is currently running, it must be blocked on
1195          * the mutex, but we'll set scan_sdata = NULL and it'll
1196          * simply exit once it acquires the mutex.
1197          */
1198         cancel_delayed_work(&local->scan_work);
1199         /* and clean up */
1200         memset(&local->scan_info, 0, sizeof(local->scan_info));
1201         __ieee80211_scan_completed(&local->hw, true);
1202 out:
1203         mutex_unlock(&local->mtx);
1204 }
1205
1206 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1207                                         struct cfg80211_sched_scan_request *req)
1208 {
1209         struct ieee80211_local *local = sdata->local;
1210         struct ieee80211_scan_ies sched_scan_ies = {};
1211         struct cfg80211_chan_def chandef;
1212         int ret, i, iebufsz, num_bands = 0;
1213         u32 rate_masks[NUM_NL80211_BANDS] = {};
1214         u8 bands_used = 0;
1215         u8 *ie;
1216         u32 flags = 0;
1217
1218         iebufsz = local->scan_ies_len + req->ie_len;
1219
1220         lockdep_assert_held(&local->mtx);
1221
1222         if (!local->ops->sched_scan_start)
1223                 return -ENOTSUPP;
1224
1225         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1226                 if (local->hw.wiphy->bands[i]) {
1227                         bands_used |= BIT(i);
1228                         rate_masks[i] = (u32) -1;
1229                         num_bands++;
1230                 }
1231         }
1232
1233         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1234                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1235
1236         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1237         if (!ie) {
1238                 ret = -ENOMEM;
1239                 goto out;
1240         }
1241
1242         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1243
1244         ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1245                                  &sched_scan_ies, req->ie,
1246                                  req->ie_len, bands_used, rate_masks, &chandef,
1247                                  flags);
1248
1249         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1250         if (ret == 0) {
1251                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1252                 rcu_assign_pointer(local->sched_scan_req, req);
1253         }
1254
1255         kfree(ie);
1256
1257 out:
1258         if (ret) {
1259                 /* Clean in case of failure after HW restart or upon resume. */
1260                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1261                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1262         }
1263
1264         return ret;
1265 }
1266
1267 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1268                                        struct cfg80211_sched_scan_request *req)
1269 {
1270         struct ieee80211_local *local = sdata->local;
1271         int ret;
1272
1273         mutex_lock(&local->mtx);
1274
1275         if (rcu_access_pointer(local->sched_scan_sdata)) {
1276                 mutex_unlock(&local->mtx);
1277                 return -EBUSY;
1278         }
1279
1280         ret = __ieee80211_request_sched_scan_start(sdata, req);
1281
1282         mutex_unlock(&local->mtx);
1283         return ret;
1284 }
1285
1286 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1287 {
1288         struct ieee80211_sub_if_data *sched_scan_sdata;
1289         int ret = -ENOENT;
1290
1291         mutex_lock(&local->mtx);
1292
1293         if (!local->ops->sched_scan_stop) {
1294                 ret = -ENOTSUPP;
1295                 goto out;
1296         }
1297
1298         /* We don't want to restart sched scan anymore. */
1299         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1300
1301         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1302                                                 lockdep_is_held(&local->mtx));
1303         if (sched_scan_sdata) {
1304                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1305                 if (!ret)
1306                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1307         }
1308 out:
1309         mutex_unlock(&local->mtx);
1310
1311         return ret;
1312 }
1313
1314 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1315 {
1316         struct ieee80211_local *local = hw_to_local(hw);
1317
1318         trace_api_sched_scan_results(local);
1319
1320         cfg80211_sched_scan_results(hw->wiphy, 0);
1321 }
1322 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1323
1324 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1325 {
1326         mutex_lock(&local->mtx);
1327
1328         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1329                 mutex_unlock(&local->mtx);
1330                 return;
1331         }
1332
1333         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1334
1335         /* If sched scan was aborted by the driver. */
1336         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1337
1338         mutex_unlock(&local->mtx);
1339
1340         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1341 }
1342
1343 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1344 {
1345         struct ieee80211_local *local =
1346                 container_of(work, struct ieee80211_local,
1347                              sched_scan_stopped_work);
1348
1349         ieee80211_sched_scan_end(local);
1350 }
1351
1352 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1353 {
1354         struct ieee80211_local *local = hw_to_local(hw);
1355
1356         trace_api_sched_scan_stopped(local);
1357
1358         /*
1359          * this shouldn't really happen, so for simplicity
1360          * simply ignore it, and let mac80211 reconfigure
1361          * the sched scan later on.
1362          */
1363         if (local->in_reconfig)
1364                 return;
1365
1366         schedule_work(&local->sched_scan_stopped_work);
1367 }
1368 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);