net/mac80211/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Scanning implementation
   4  *
   5  * Copyright 2003, Jouni Malinen <[email protected]>
   6  * Copyright 2004, Instant802 Networks, Inc.
   7  * Copyright 2005, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <[email protected]>
   9  * Copyright 2007, Michael Wu <[email protected]>
  10  * Copyright 2013-2015  Intel Mobile Communications GmbH
  11  * Copyright 2016-2017  Intel Deutschland GmbH
  12  * Copyright (C) 2018-2024 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 struct inform_bss_update_data {
  59         struct ieee80211_rx_status *rx_status;
  60         bool beacon;
  61 };
  62
  63 void ieee80211_inform_bss(struct wiphy *wiphy,
  64                           struct cfg80211_bss *cbss,
  65                           const struct cfg80211_bss_ies *ies,
  66                           void *data)
  67 {
  68         struct ieee80211_local *local = wiphy_priv(wiphy);
  69         struct inform_bss_update_data *update_data = data;
  70         struct ieee80211_bss *bss = (void *)cbss->priv;
  71         struct ieee80211_rx_status *rx_status;
  72         struct ieee802_11_elems *elems;
  73         int clen, srlen;
  74
  75         /* This happens while joining an IBSS */
  76         if (!update_data)
  77                 return;
  78
  79         elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
  80         if (!elems)
  81                 return;
  82
  83         rx_status = update_data->rx_status;
  84
  85         if (update_data->beacon)
  86                 bss->device_ts_beacon = rx_status->device_timestamp;
  87         else
  88                 bss->device_ts_presp = rx_status->device_timestamp;
  89
  90         if (elems->parse_error) {
  91                 if (update_data->beacon)
  92                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
  93                 else
  94                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
  95         } else {
  96                 if (update_data->beacon)
  97                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
  98                 else
  99                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
 100         }
 101
 102         /* save the ERP value so that it is available at association time */
 103         if (elems->erp_info && (!elems->parse_error ||
 104                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
 105                 bss->erp_value = elems->erp_info[0];
 106                 bss->has_erp_value = true;
 107                 if (!elems->parse_error)
 108                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
 109         }
 110
 111         /* replace old supported rates if we get new values */
 112         if (!elems->parse_error ||
 113             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
 114                 srlen = 0;
 115                 if (elems->supp_rates) {
 116                         clen = IEEE80211_MAX_SUPP_RATES;
 117                         if (clen > elems->supp_rates_len)
 118                                 clen = elems->supp_rates_len;
 119                         memcpy(bss->supp_rates, elems->supp_rates, clen);
 120                         srlen += clen;
 121                 }
 122                 if (elems->ext_supp_rates) {
 123                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 124                         if (clen > elems->ext_supp_rates_len)
 125                                 clen = elems->ext_supp_rates_len;
 126                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 127                                clen);
 128                         srlen += clen;
 129                 }
 130                 if (srlen) {
 131                         bss->supp_rates_len = srlen;
 132                         if (!elems->parse_error)
 133                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 134                 }
 135         }
 136
 137         if (!elems->parse_error ||
 138             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 139                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
 140                 bss->uapsd_supported = is_uapsd_supported(elems);
 141                 if (!elems->parse_error)
 142                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 143         }
 144
 145         if (update_data->beacon) {
 146                 struct ieee80211_supported_band *sband =
 147                         local->hw.wiphy->bands[rx_status->band];
 148                 if (!(rx_status->encoding == RX_ENC_HT) &&
 149                     !(rx_status->encoding == RX_ENC_VHT))
 150                         bss->beacon_rate =
 151                                 &sband->bitrates[rx_status->rate_idx];
 152         }
 153
 154         if (elems->vht_cap_elem)
 155                 bss->vht_cap_info =
 156                         le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
 157         else
 158                 bss->vht_cap_info = 0;
 159
 160         kfree(elems);
 161 }
 162
 163 struct ieee80211_bss *
 164 ieee80211_bss_info_update(struct ieee80211_local *local,
 165                           struct ieee80211_rx_status *rx_status,
 166                           struct ieee80211_mgmt *mgmt, size_t len,
 167                           struct ieee80211_channel *channel)
 168 {
 169         bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
 170                       ieee80211_is_s1g_beacon(mgmt->frame_control);
 171         struct cfg80211_bss *cbss;
 172         struct inform_bss_update_data update_data = {
 173                 .rx_status = rx_status,
 174                 .beacon = beacon,
 175         };
 176         struct cfg80211_inform_bss bss_meta = {
 177                 .boottime_ns = rx_status->boottime_ns,
 178                 .drv_data = (void *)&update_data,
 179         };
 180         bool signal_valid;
 181         struct ieee80211_sub_if_data *scan_sdata;
 182
 183         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
 184                 bss_meta.signal = 0; /* invalid signal indication */
 185         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
 186                 bss_meta.signal = rx_status->signal * 100;
 187         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
 188                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
 189
 190         bss_meta.chan = channel;
 191
 192         rcu_read_lock();
 193         scan_sdata = rcu_dereference(local->scan_sdata);
 194         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
 195             scan_sdata->vif.cfg.assoc &&
 196             ieee80211_have_rx_timestamp(rx_status)) {
 197                 struct ieee80211_bss_conf *link_conf = NULL;
 198
 199                 /* for an MLO connection, set the TSF data only in case we have
 200                  * an indication on which of the links the frame was received
 201                  */
 202                 if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
 203                         if (rx_status->link_valid) {
 204                                 s8 link_id = rx_status->link_id;
 205
 206                                 link_conf =
 207                                         rcu_dereference(scan_sdata->vif.link_conf[link_id]);
 208                         }
 209                 } else {
 210                         link_conf = &scan_sdata->vif.bss_conf;
 211                 }
 212
 213                 if (link_conf) {
 214                         bss_meta.parent_tsf =
 215                                 ieee80211_calculate_rx_timestamp(local,
 216                                                                  rx_status,
 217                                                                  len + FCS_LEN,
 218                                                                  24);
 219
 220                         ether_addr_copy(bss_meta.parent_bssid,
 221                                         link_conf->bssid);
 222                 }
 223         }
 224         rcu_read_unlock();
 225
 226         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 227                                               mgmt, len, GFP_ATOMIC);
 228         if (!cbss)
 229                 return NULL;
 230
 231         /* In case the signal is invalid update the status */
 232         signal_valid = channel == cbss->channel;
 233         if (!signal_valid)
 234                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 235
 236         return (void *)cbss->priv;
 237 }
 238
 239 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 240                                         struct ieee80211_channel *channel,
 241                                         u32 scan_flags, const u8 *da)
 242 {
 243         if (!sdata)
 244                 return false;
 245
 246         /* accept broadcast on 6 GHz and for OCE */
 247         if (is_broadcast_ether_addr(da) &&
 248             (channel->band == NL80211_BAND_6GHZ ||
 249              scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
 250                 return true;
 251
 252         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 253                 return true;
 254         return ether_addr_equal(da, sdata->vif.addr);
 255 }
 256
 257 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 258 {
 259         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 260         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 261         struct ieee80211_bss *bss;
 262         struct ieee80211_channel *channel;
 263         size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 264                                       u.probe_resp.variable);
 265
 266         if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 267             !ieee80211_is_beacon(mgmt->frame_control) &&
 268             !ieee80211_is_s1g_beacon(mgmt->frame_control))
 269                 return;
 270
 271         if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 272                 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 273                         min_hdr_len = offsetof(struct ieee80211_ext,
 274                                                u.s1g_short_beacon.variable);
 275                 else
 276                         min_hdr_len = offsetof(struct ieee80211_ext,
 277                                                u.s1g_beacon);
 278         }
 279
 280         if (skb->len < min_hdr_len)
 281                 return;
 282
 283         if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
 284                 /*
 285                  * we were passive scanning because of radar/no-IR, but
 286                  * the beacon/proberesp rx gives us an opportunity to upgrade
 287                  * to active scan
 288                  */
 289                 set_bit(SCAN_BEACON_DONE, &local->scanning);
 290                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 291         }
 292
 293         channel = ieee80211_get_channel_khz(local->hw.wiphy,
 294                                             ieee80211_rx_status_to_khz(rx_status));
 295
 296         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 297                 return;
 298
 299         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 300                 struct ieee80211_sub_if_data *sdata1, *sdata2;
 301                 struct cfg80211_scan_request *scan_req;
 302                 struct cfg80211_sched_scan_request *sched_scan_req;
 303                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 304
 305                 sdata1 = rcu_dereference(local->scan_sdata);
 306                 sdata2 = rcu_dereference(local->sched_scan_sdata);
 307
 308                 if (likely(!sdata1 && !sdata2))
 309                         return;
 310
 311                 scan_req = rcu_dereference(local->scan_req);
 312                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 313
 314                 if (scan_req)
 315                         scan_req_flags = scan_req->flags;
 316
 317                 if (sched_scan_req)
 318                         sched_scan_req_flags = sched_scan_req->flags;
 319
 320                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 321                  * unless scanning with randomised address
 322                  */
 323                 if (!ieee80211_scan_accept_presp(sdata1, channel,
 324                                                  scan_req_flags,
 325                                                  mgmt->da) &&
 326                     !ieee80211_scan_accept_presp(sdata2, channel,
 327                                                  sched_scan_req_flags,
 328                                                  mgmt->da))
 329                         return;
 330         } else {
 331                 /* Beacons are expected only with broadcast address */
 332                 if (!is_broadcast_ether_addr(mgmt->da))
 333                         return;
 334         }
 335
 336         /* Do not update the BSS table in case of only monitor interfaces */
 337         if (local->open_count == local->monitors)
 338                 return;
 339
 340         bss = ieee80211_bss_info_update(local, rx_status,
 341                                         mgmt, skb->len,
 342                                         channel);
 343         if (bss)
 344                 ieee80211_rx_bss_put(local, bss);
 345 }
 346
 347 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
 348 {
 349         memset(chandef, 0, sizeof(*chandef));
 350
 351         chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 352 }
 353
 354 /* return false if no more work */
 355 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 356 {
 357         struct ieee80211_local *local = sdata->local;
 358         struct cfg80211_scan_request *req;
 359         struct cfg80211_chan_def chandef;
 360         u8 bands_used = 0;
 361         int i, ielen;
 362         u32 *n_chans;
 363         u32 flags = 0;
 364
 365         req = rcu_dereference_protected(local->scan_req,
 366                                         lockdep_is_held(&local->hw.wiphy->mtx));
 367
 368         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 369                 return false;
 370
 371         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 372                 local->hw_scan_req->req.n_channels = req->n_channels;
 373
 374                 for (i = 0; i < req->n_channels; i++) {
 375                         local->hw_scan_req->req.channels[i] = req->channels[i];
 376                         bands_used |= BIT(req->channels[i]->band);
 377                 }
 378         } else {
 379                 do {
 380                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 381                                 return false;
 382
 383                         n_chans = &local->hw_scan_req->req.n_channels;
 384                         *n_chans = 0;
 385
 386                         for (i = 0; i < req->n_channels; i++) {
 387                                 if (req->channels[i]->band !=
 388                                     local->hw_scan_band)
 389                                         continue;
 390                                 local->hw_scan_req->req.channels[(*n_chans)++] =
 391                                                         req->channels[i];
 392
 393                                 bands_used |= BIT(req->channels[i]->band);
 394                         }
 395
 396                         local->hw_scan_band++;
 397                 } while (!*n_chans);
 398         }
 399
 400         ieee80211_prepare_scan_chandef(&chandef);
 401
 402         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 403                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 404
 405         ielen = ieee80211_build_preq_ies(sdata,
 406                                          (u8 *)local->hw_scan_req->req.ie,
 407                                          local->hw_scan_ies_bufsize,
 408                                          &local->hw_scan_req->ies,
 409                                          req->ie, req->ie_len,
 410                                          bands_used, req->rates, &chandef,
 411                                          flags);
 412         if (ielen < 0)
 413                 return false;
 414         local->hw_scan_req->req.ie_len = ielen;
 415         local->hw_scan_req->req.no_cck = req->no_cck;
 416         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 417         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 418                         req->mac_addr_mask);
 419         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 420
 421         return true;
 422 }
 423
 424 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 425 {
 426         struct ieee80211_local *local = hw_to_local(hw);
 427         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 428         bool was_scanning = local->scanning;
 429         struct cfg80211_scan_request *scan_req;
 430         struct ieee80211_sub_if_data *scan_sdata;
 431         struct ieee80211_sub_if_data *sdata;
 432
 433         lockdep_assert_wiphy(local->hw.wiphy);
 434
 435         /*
 436          * It's ok to abort a not-yet-running scan (that
 437          * we have one at all will be verified by checking
 438          * local->scan_req next), but not to complete it
 439          * successfully.
 440          */
 441         if (WARN_ON(!local->scanning && !aborted))
 442                 aborted = true;
 443
 444         if (WARN_ON(!local->scan_req))
 445                 return;
 446
 447         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 448                                                lockdep_is_held(&local->hw.wiphy->mtx));
 449
 450         if (hw_scan && !aborted &&
 451             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 452             ieee80211_prep_hw_scan(scan_sdata)) {
 453                 int rc;
 454
 455                 rc = drv_hw_scan(local,
 456                         rcu_dereference_protected(local->scan_sdata,
 457                                                   lockdep_is_held(&local->hw.wiphy->mtx)),
 458                         local->hw_scan_req);
 459
 460                 if (rc == 0)
 461                         return;
 462
 463                 /* HW scan failed and is going to be reported as aborted,
 464                  * so clear old scan info.
 465                  */
 466                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 467                 aborted = true;
 468         }
 469
 470         kfree(local->hw_scan_req);
 471         local->hw_scan_req = NULL;
 472
 473         scan_req = rcu_dereference_protected(local->scan_req,
 474                                              lockdep_is_held(&local->hw.wiphy->mtx));
 475
 476         RCU_INIT_POINTER(local->scan_req, NULL);
 477         RCU_INIT_POINTER(local->scan_sdata, NULL);
 478
 479         local->scanning = 0;
 480         local->scan_chandef.chan = NULL;
 481
 482         synchronize_rcu();
 483
 484         if (scan_req != local->int_scan_req) {
 485                 local->scan_info.aborted = aborted;
 486                 cfg80211_scan_done(scan_req, &local->scan_info);
 487         }
 488
 489         /* Set power back to normal operating levels. */
 490         ieee80211_hw_conf_chan(local);
 491
 492         if (!hw_scan && was_scanning) {
 493                 ieee80211_configure_filter(local);
 494                 drv_sw_scan_complete(local, scan_sdata);
 495                 ieee80211_offchannel_return(local);
 496         }
 497
 498         ieee80211_recalc_idle(local);
 499
 500         ieee80211_mlme_notify_scan_completed(local);
 501         ieee80211_ibss_notify_scan_completed(local);
 502
 503         /* Requeue all the work that might have been ignored while
 504          * the scan was in progress; if there was none this will
 505          * just be a no-op for the particular interface.
 506          */
 507         list_for_each_entry(sdata, &local->interfaces, list) {
 508                 if (ieee80211_sdata_running(sdata))
 509                         wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
 510         }
 511
 512         if (was_scanning)
 513                 ieee80211_start_next_roc(local);
 514 }
 515
 516 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 517                               struct cfg80211_scan_info *info)
 518 {
 519         struct ieee80211_local *local = hw_to_local(hw);
 520
 521         trace_api_scan_completed(local, info->aborted);
 522
 523         set_bit(SCAN_COMPLETED, &local->scanning);
 524         if (info->aborted)
 525                 set_bit(SCAN_ABORTED, &local->scanning);
 526
 527         memcpy(&local->scan_info, info, sizeof(*info));
 528
 529         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 530 }
 531 EXPORT_SYMBOL(ieee80211_scan_completed);
 532
 533 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 534                                    struct ieee80211_sub_if_data *sdata)
 535 {
 536         /* Software scan is not supported in multi-channel cases */
 537         if (!local->emulate_chanctx)
 538                 return -EOPNOTSUPP;
 539
 540         /*
 541          * Hardware/driver doesn't support hw_scan, so use software
 542          * scanning instead. First send a nullfunc frame with power save
 543          * bit on so that AP will buffer the frames for us while we are not
 544          * listening, then send probe requests to each channel and wait for
 545          * the responses. After all channels are scanned, tune back to the
 546          * original channel and send a nullfunc frame with power save bit
 547          * off to trigger the AP to send us all the buffered frames.
 548          *
 549          * Note that while local->sw_scanning is true everything else but
 550          * nullfunc frames and probe requests will be dropped in
 551          * ieee80211_tx_h_check_assoc().
 552          */
 553         drv_sw_scan_start(local, sdata, local->scan_addr);
 554
 555         local->leave_oper_channel_time = jiffies;
 556         local->next_scan_state = SCAN_DECISION;
 557         local->scan_channel_idx = 0;
 558
 559         ieee80211_offchannel_stop_vifs(local);
 560
 561         /* ensure nullfunc is transmitted before leaving operating channel */
 562         ieee80211_flush_queues(local, NULL, false);
 563
 564         ieee80211_configure_filter(local);
 565
 566         /* We need to set power level at maximum rate for scanning. */
 567         ieee80211_hw_conf_chan(local);
 568
 569         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 570
 571         return 0;
 572 }
 573
 574 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 575 {
 576         struct ieee80211_local *local = sdata->local;
 577         struct ieee80211_sub_if_data *sdata_iter;
 578         unsigned int link_id;
 579
 580         lockdep_assert_wiphy(local->hw.wiphy);
 581
 582         if (!ieee80211_is_radar_required(local))
 583                 return true;
 584
 585         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 586                 return false;
 587
 588         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 589                 for_each_valid_link(&sdata_iter->wdev, link_id)
 590                         if (sdata_iter->wdev.links[link_id].cac_started)
 591                                 return false;
 592         }
 593
 594         return true;
 595 }
 596
 597 static bool ieee80211_can_scan(struct ieee80211_local *local,
 598                                struct ieee80211_sub_if_data *sdata)
 599 {
 600         if (!__ieee80211_can_leave_ch(sdata))
 601                 return false;
 602
 603         if (!list_empty(&local->roc_list))
 604                 return false;
 605
 606         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 607             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 608                 return false;
 609
 610         return true;
 611 }
 612
 613 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 614 {
 615         lockdep_assert_wiphy(local->hw.wiphy);
 616
 617         if (!local->scan_req || local->scanning)
 618                 return;
 619
 620         if (!ieee80211_can_scan(local,
 621                                 rcu_dereference_protected(
 622                                         local->scan_sdata,
 623                                         lockdep_is_held(&local->hw.wiphy->mtx))))
 624                 return;
 625
 626         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 627                                  round_jiffies_relative(0));
 628 }
 629
 630 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 631                                           const u8 *src, const u8 *dst,
 632                                           const u8 *ssid, size_t ssid_len,
 633                                           const u8 *ie, size_t ie_len,
 634                                           u32 ratemask, u32 flags, u32 tx_flags,
 635                                           struct ieee80211_channel *channel)
 636 {
 637         struct sk_buff *skb;
 638
 639         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 640                                         ssid, ssid_len,
 641                                         ie, ie_len, flags);
 642
 643         if (skb) {
 644                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 645                         struct ieee80211_hdr *hdr = (void *)skb->data;
 646                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 647                         u16 sn = get_random_u16();
 648
 649                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 650                         hdr->seq_ctrl =
 651                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 652                 }
 653                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 654                 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
 655                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 656         }
 657 }
 658
 659 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 660                                             unsigned long *next_delay)
 661 {
 662         int i;
 663         struct ieee80211_sub_if_data *sdata;
 664         struct cfg80211_scan_request *scan_req;
 665         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 666         u32 flags = 0, tx_flags;
 667
 668         scan_req = rcu_dereference_protected(local->scan_req,
 669                                              lockdep_is_held(&local->hw.wiphy->mtx));
 670
 671         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 672         if (scan_req->no_cck)
 673                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 674         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 675                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 676         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 677                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 678
 679         sdata = rcu_dereference_protected(local->scan_sdata,
 680                                           lockdep_is_held(&local->hw.wiphy->mtx));
 681
 682         for (i = 0; i < scan_req->n_ssids; i++)
 683                 ieee80211_send_scan_probe_req(
 684                         sdata, local->scan_addr, scan_req->bssid,
 685                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 686                         scan_req->ie, scan_req->ie_len,
 687                         scan_req->rates[band], flags,
 688                         tx_flags, local->hw.conf.chandef.chan);
 689
 690         /*
 691          * After sending probe requests, wait for probe responses
 692          * on the channel.
 693          */
 694         *next_delay = msecs_to_jiffies(scan_req->duration) >
 695                       IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
 696                       msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
 697                       IEEE80211_CHANNEL_TIME;
 698         local->next_scan_state = SCAN_DECISION;
 699 }
 700
 701 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 702                                   struct cfg80211_scan_request *req)
 703 {
 704         struct ieee80211_local *local = sdata->local;
 705         bool hw_scan = local->ops->hw_scan;
 706         int rc;
 707
 708         lockdep_assert_wiphy(local->hw.wiphy);
 709
 710         if (local->scan_req)
 711                 return -EBUSY;
 712
 713         /* For an MLO connection, if a link ID was specified, validate that it
 714          * is indeed active.
 715          */
 716         if (ieee80211_vif_is_mld(&sdata->vif) && req->tsf_report_link_id >= 0 &&
 717             !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
 718                 return -EINVAL;
 719
 720         if (!__ieee80211_can_leave_ch(sdata))
 721                 return -EBUSY;
 722
 723         if (!ieee80211_can_scan(local, sdata)) {
 724                 /* wait for the work to finish/time out */
 725                 rcu_assign_pointer(local->scan_req, req);
 726                 rcu_assign_pointer(local->scan_sdata, sdata);
 727                 return 0;
 728         }
 729
 730  again:
 731         if (hw_scan) {
 732                 u8 *ies;
 733
 734                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 735
 736                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 737                         int i, n_bands = 0;
 738                         u8 bands_counted = 0;
 739
 740                         for (i = 0; i < req->n_channels; i++) {
 741                                 if (bands_counted & BIT(req->channels[i]->band))
 742                                         continue;
 743                                 bands_counted |= BIT(req->channels[i]->band);
 744                                 n_bands++;
 745                         }
 746
 747                         local->hw_scan_ies_bufsize *= n_bands;
 748                 }
 749
 750                 local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
 751                                                          req.channels,
 752                                                          req->n_channels) +
 753                                              local->hw_scan_ies_bufsize,
 754                                              GFP_KERNEL);
 755                 if (!local->hw_scan_req)
 756                         return -ENOMEM;
 757
 758                 local->hw_scan_req->req.ssids = req->ssids;
 759                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 760                 /* None of the channels are actually set
 761                  * up but let UBSAN know the boundaries.
 762                  */
 763                 local->hw_scan_req->req.n_channels = req->n_channels;
 764
 765                 ies = (u8 *)local->hw_scan_req +
 766                         sizeof(*local->hw_scan_req) +
 767                         req->n_channels * sizeof(req->channels[0]);
 768                 local->hw_scan_req->req.ie = ies;
 769                 local->hw_scan_req->req.flags = req->flags;
 770                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 771                 local->hw_scan_req->req.duration = req->duration;
 772                 local->hw_scan_req->req.duration_mandatory =
 773                         req->duration_mandatory;
 774                 local->hw_scan_req->req.tsf_report_link_id =
 775                         req->tsf_report_link_id;
 776
 777                 local->hw_scan_band = 0;
 778                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 779                 local->hw_scan_req->req.scan_6ghz_params =
 780                         req->scan_6ghz_params;
 781                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 782
 783                 /*
 784                  * After allocating local->hw_scan_req, we must
 785                  * go through until ieee80211_prep_hw_scan(), so
 786                  * anything that might be changed here and leave
 787                  * this function early must not go after this
 788                  * allocation.
 789                  */
 790         }
 791
 792         rcu_assign_pointer(local->scan_req, req);
 793         rcu_assign_pointer(local->scan_sdata, sdata);
 794
 795         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 796                 get_random_mask_addr(local->scan_addr,
 797                                      req->mac_addr,
 798                                      req->mac_addr_mask);
 799         else
 800                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 801
 802         if (hw_scan) {
 803                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 804         } else if ((req->n_channels == 1) &&
 805                    (req->channels[0] == local->hw.conf.chandef.chan)) {
 806                 /*
 807                  * If we are scanning only on the operating channel
 808                  * then we do not need to stop normal activities
 809                  */
 810                 unsigned long next_delay;
 811
 812                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 813
 814                 ieee80211_recalc_idle(local);
 815
 816                 /* Notify driver scan is starting, keep order of operations
 817                  * same as normal software scan, in case that matters. */
 818                 drv_sw_scan_start(local, sdata, local->scan_addr);
 819
 820                 ieee80211_configure_filter(local); /* accept probe-responses */
 821
 822                 /* We need to ensure power level is at max for scanning. */
 823                 ieee80211_hw_conf_chan(local);
 824
 825                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 826                                                 IEEE80211_CHAN_RADAR)) ||
 827                     !req->n_ssids) {
 828                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 829                         if (req->n_ssids)
 830                                 set_bit(SCAN_BEACON_WAIT, &local->scanning);
 831                 } else {
 832                         ieee80211_scan_state_send_probe(local, &next_delay);
 833                         next_delay = IEEE80211_CHANNEL_TIME;
 834                 }
 835
 836                 /* Now, just wait a bit and we are all done! */
 837                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 838                                          next_delay);
 839                 return 0;
 840         } else {
 841                 /* Do normal software scan */
 842                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 843         }
 844
 845         ieee80211_recalc_idle(local);
 846
 847         if (hw_scan) {
 848                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 849                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 850         } else {
 851                 rc = ieee80211_start_sw_scan(local, sdata);
 852         }
 853
 854         if (rc) {
 855                 kfree(local->hw_scan_req);
 856                 local->hw_scan_req = NULL;
 857                 local->scanning = 0;
 858
 859                 ieee80211_recalc_idle(local);
 860
 861                 local->scan_req = NULL;
 862                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 863         }
 864
 865         if (hw_scan && rc == 1) {
 866                 /*
 867                  * we can't fall back to software for P2P-GO
 868                  * as it must update NoA etc.
 869                  */
 870                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 871                                 NL80211_IFTYPE_P2P_GO)
 872                         return -EOPNOTSUPP;
 873                 hw_scan = false;
 874                 goto again;
 875         }
 876
 877         return rc;
 878 }
 879
 880 static unsigned long
 881 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 882 {
 883         /*
 884          * TODO: channel switching also consumes quite some time,
 885          * add that delay as well to get a better estimation
 886          */
 887         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 888                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 889         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 890 }
 891
 892 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 893                                           unsigned long *next_delay)
 894 {
 895         bool associated = false;
 896         bool tx_empty = true;
 897         bool bad_latency;
 898         struct ieee80211_sub_if_data *sdata;
 899         struct ieee80211_channel *next_chan;
 900         enum mac80211_scan_state next_scan_state;
 901         struct cfg80211_scan_request *scan_req;
 902
 903         lockdep_assert_wiphy(local->hw.wiphy);
 904
 905         /*
 906          * check if at least one STA interface is associated,
 907          * check if at least one STA interface has pending tx frames
 908          * and grab the lowest used beacon interval
 909          */
 910         list_for_each_entry(sdata, &local->interfaces, list) {
 911                 if (!ieee80211_sdata_running(sdata))
 912                         continue;
 913
 914                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 915                         if (sdata->u.mgd.associated) {
 916                                 associated = true;
 917
 918                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 919                                         tx_empty = false;
 920                                         break;
 921                                 }
 922                         }
 923                 }
 924         }
 925
 926         scan_req = rcu_dereference_protected(local->scan_req,
 927                                              lockdep_is_held(&local->hw.wiphy->mtx));
 928
 929         next_chan = scan_req->channels[local->scan_channel_idx];
 930
 931         /*
 932          * we're currently scanning a different channel, let's
 933          * see if we can scan another channel without interfering
 934          * with the current traffic situation.
 935          *
 936          * Keep good latency, do not stay off-channel more than 125 ms.
 937          */
 938
 939         bad_latency = time_after(jiffies +
 940                                  ieee80211_scan_get_channel_time(next_chan),
 941                                  local->leave_oper_channel_time + HZ / 8);
 942
 943         if (associated && !tx_empty) {
 944                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 945                         next_scan_state = SCAN_ABORT;
 946                 else
 947                         next_scan_state = SCAN_SUSPEND;
 948         } else if (associated && bad_latency) {
 949                 next_scan_state = SCAN_SUSPEND;
 950         } else {
 951                 next_scan_state = SCAN_SET_CHANNEL;
 952         }
 953
 954         local->next_scan_state = next_scan_state;
 955
 956         *next_delay = 0;
 957 }
 958
 959 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 960                                              unsigned long *next_delay)
 961 {
 962         int skip;
 963         struct ieee80211_channel *chan;
 964         struct cfg80211_scan_request *scan_req;
 965
 966         scan_req = rcu_dereference_protected(local->scan_req,
 967                                              lockdep_is_held(&local->hw.wiphy->mtx));
 968
 969         skip = 0;
 970         chan = scan_req->channels[local->scan_channel_idx];
 971
 972         local->scan_chandef.chan = chan;
 973         local->scan_chandef.center_freq1 = chan->center_freq;
 974         local->scan_chandef.freq1_offset = chan->freq_offset;
 975         local->scan_chandef.center_freq2 = 0;
 976
 977         /* For scanning on the S1G band, detect the channel width according to
 978          * the channel being scanned.
 979          */
 980         if (chan->band == NL80211_BAND_S1GHZ) {
 981                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 982                 goto set_channel;
 983         }
 984
 985         /* If scanning on oper channel, use whatever channel-type
 986          * is currently in use.
 987          */
 988         if (chan == local->hw.conf.chandef.chan)
 989                 local->scan_chandef = local->hw.conf.chandef;
 990         else
 991                 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 992
 993 set_channel:
 994         if (ieee80211_hw_conf_chan(local))
 995                 skip = 1;
 996
 997         /* advance state machine to next channel/band */
 998         local->scan_channel_idx++;
 999
1000         if (skip) {
1001                 /* if we skip this channel return to the decision state */
1002                 local->next_scan_state = SCAN_DECISION;
1003                 return;
1004         }
1005
1006         /*
1007          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1008          * (which unfortunately doesn't say _why_ step a) is done,
1009          * but it waits for the probe delay or until a frame is
1010          * received - and the received frame would update the NAV).
1011          * For now, we do not support waiting until a frame is
1012          * received.
1013          *
1014          * In any case, it is not necessary for a passive scan.
1015          */
1016         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1017             !scan_req->n_ssids) {
1018                 *next_delay = max(msecs_to_jiffies(scan_req->duration),
1019                                   IEEE80211_PASSIVE_CHANNEL_TIME);
1020                 local->next_scan_state = SCAN_DECISION;
1021                 if (scan_req->n_ssids)
1022                         set_bit(SCAN_BEACON_WAIT, &local->scanning);
1023                 return;
1024         }
1025
1026         /* active scan, send probes */
1027         *next_delay = IEEE80211_PROBE_DELAY;
1028         local->next_scan_state = SCAN_SEND_PROBE;
1029 }
1030
1031 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1032                                          unsigned long *next_delay)
1033 {
1034         /* switch back to the operating channel */
1035         local->scan_chandef.chan = NULL;
1036         ieee80211_hw_conf_chan(local);
1037
1038         /* disable PS */
1039         ieee80211_offchannel_return(local);
1040
1041         *next_delay = HZ / 5;
1042         /* afterwards, resume scan & go to next channel */
1043         local->next_scan_state = SCAN_RESUME;
1044 }
1045
1046 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1047                                         unsigned long *next_delay)
1048 {
1049         ieee80211_offchannel_stop_vifs(local);
1050
1051         if (local->ops->flush) {
1052                 ieee80211_flush_queues(local, NULL, false);
1053                 *next_delay = 0;
1054         } else
1055                 *next_delay = HZ / 10;
1056
1057         /* remember when we left the operating channel */
1058         local->leave_oper_channel_time = jiffies;
1059
1060         /* advance to the next channel to be scanned */
1061         local->next_scan_state = SCAN_SET_CHANNEL;
1062 }
1063
1064 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1065 {
1066         struct ieee80211_local *local =
1067                 container_of(work, struct ieee80211_local, scan_work.work);
1068         struct ieee80211_sub_if_data *sdata;
1069         struct cfg80211_scan_request *scan_req;
1070         unsigned long next_delay = 0;
1071         bool aborted;
1072
1073         lockdep_assert_wiphy(local->hw.wiphy);
1074
1075         if (!ieee80211_can_run_worker(local)) {
1076                 aborted = true;
1077                 goto out_complete;
1078         }
1079
1080         sdata = rcu_dereference_protected(local->scan_sdata,
1081                                           lockdep_is_held(&local->hw.wiphy->mtx));
1082         scan_req = rcu_dereference_protected(local->scan_req,
1083                                              lockdep_is_held(&local->hw.wiphy->mtx));
1084
1085         /* When scanning on-channel, the first-callback means completed. */
1086         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1087                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1088                 goto out_complete;
1089         }
1090
1091         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1092                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1093                 goto out_complete;
1094         }
1095
1096         if (!sdata || !scan_req)
1097                 return;
1098
1099         if (!local->scanning) {
1100                 int rc;
1101
1102                 RCU_INIT_POINTER(local->scan_req, NULL);
1103                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1104
1105                 rc = __ieee80211_start_scan(sdata, scan_req);
1106                 if (!rc)
1107                         return;
1108                 /* need to complete scan in cfg80211 */
1109                 rcu_assign_pointer(local->scan_req, scan_req);
1110                 aborted = true;
1111                 goto out_complete;
1112         }
1113
1114         clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1115
1116         /*
1117          * as long as no delay is required advance immediately
1118          * without scheduling a new work
1119          */
1120         do {
1121                 if (!ieee80211_sdata_running(sdata)) {
1122                         aborted = true;
1123                         goto out_complete;
1124                 }
1125
1126                 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1127                     local->next_scan_state == SCAN_DECISION)
1128                         local->next_scan_state = SCAN_SEND_PROBE;
1129
1130                 switch (local->next_scan_state) {
1131                 case SCAN_DECISION:
1132                         /* if no more bands/channels left, complete scan */
1133                         if (local->scan_channel_idx >= scan_req->n_channels) {
1134                                 aborted = false;
1135                                 goto out_complete;
1136                         }
1137                         ieee80211_scan_state_decision(local, &next_delay);
1138                         break;
1139                 case SCAN_SET_CHANNEL:
1140                         ieee80211_scan_state_set_channel(local, &next_delay);
1141                         break;
1142                 case SCAN_SEND_PROBE:
1143                         ieee80211_scan_state_send_probe(local, &next_delay);
1144                         break;
1145                 case SCAN_SUSPEND:
1146                         ieee80211_scan_state_suspend(local, &next_delay);
1147                         break;
1148                 case SCAN_RESUME:
1149                         ieee80211_scan_state_resume(local, &next_delay);
1150                         break;
1151                 case SCAN_ABORT:
1152                         aborted = true;
1153                         goto out_complete;
1154                 }
1155         } while (next_delay == 0);
1156
1157         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1158                                  next_delay);
1159         return;
1160
1161 out_complete:
1162         __ieee80211_scan_completed(&local->hw, aborted);
1163 }
1164
1165 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1166                            struct cfg80211_scan_request *req)
1167 {
1168         lockdep_assert_wiphy(sdata->local->hw.wiphy);
1169
1170         return __ieee80211_start_scan(sdata, req);
1171 }
1172
1173 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1174                                 const u8 *ssid, u8 ssid_len,
1175                                 struct ieee80211_channel **channels,
1176                                 unsigned int n_channels)
1177 {
1178         struct ieee80211_local *local = sdata->local;
1179         int i, n_ch = 0;
1180         enum nl80211_band band;
1181
1182         lockdep_assert_wiphy(local->hw.wiphy);
1183
1184         /* busy scanning */
1185         if (local->scan_req)
1186                 return -EBUSY;
1187
1188         /* fill internal scan request */
1189         if (!channels) {
1190                 int max_n;
1191
1192                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1193                         if (!local->hw.wiphy->bands[band] ||
1194                             band == NL80211_BAND_6GHZ)
1195                                 continue;
1196
1197                         max_n = local->hw.wiphy->bands[band]->n_channels;
1198                         for (i = 0; i < max_n; i++) {
1199                                 struct ieee80211_channel *tmp_ch =
1200                                     &local->hw.wiphy->bands[band]->channels[i];
1201
1202                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1203                                                      IEEE80211_CHAN_DISABLED) ||
1204                                     !cfg80211_wdev_channel_allowed(&sdata->wdev,
1205                                                                    tmp_ch))
1206                                         continue;
1207
1208                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1209                                 n_ch++;
1210                         }
1211                 }
1212
1213                 if (WARN_ON_ONCE(n_ch == 0))
1214                         return -EINVAL;
1215
1216                 local->int_scan_req->n_channels = n_ch;
1217         } else {
1218                 for (i = 0; i < n_channels; i++) {
1219                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1220                                                   IEEE80211_CHAN_DISABLED) ||
1221                             !cfg80211_wdev_channel_allowed(&sdata->wdev,
1222                                                            channels[i]))
1223                                 continue;
1224
1225                         local->int_scan_req->channels[n_ch] = channels[i];
1226                         n_ch++;
1227                 }
1228
1229                 if (n_ch == 0)
1230                         return -EINVAL;
1231
1232                 local->int_scan_req->n_channels = n_ch;
1233         }
1234
1235         local->int_scan_req->ssids = &local->scan_ssid;
1236         local->int_scan_req->n_ssids = 1;
1237         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1238         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1239
1240         return __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1241 }
1242
1243 void ieee80211_scan_cancel(struct ieee80211_local *local)
1244 {
1245         /* ensure a new scan cannot be queued */
1246         lockdep_assert_wiphy(local->hw.wiphy);
1247
1248         /*
1249          * We are canceling software scan, or deferred scan that was not
1250          * yet really started (see __ieee80211_start_scan ).
1251          *
1252          * Regarding hardware scan:
1253          * - we can not call  __ieee80211_scan_completed() as when
1254          *   SCAN_HW_SCANNING bit is set this function change
1255          *   local->hw_scan_req to operate on 5G band, what race with
1256          *   driver which can use local->hw_scan_req
1257          *
1258          * - we can not cancel scan_work since driver can schedule it
1259          *   by ieee80211_scan_completed(..., true) to finish scan
1260          *
1261          * Hence we only call the cancel_hw_scan() callback, but the low-level
1262          * driver is still responsible for calling ieee80211_scan_completed()
1263          * after the scan was completed/aborted.
1264          */
1265
1266         if (!local->scan_req)
1267                 return;
1268
1269         /*
1270          * We have a scan running and the driver already reported completion,
1271          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1272          * cancelled.
1273          */
1274         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1275             test_bit(SCAN_COMPLETED, &local->scanning)) {
1276                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1277                 return;
1278         }
1279
1280         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1281                 /*
1282                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1283                  * scan on another band.
1284                  */
1285                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1286                 if (local->ops->cancel_hw_scan)
1287                         drv_cancel_hw_scan(local,
1288                                 rcu_dereference_protected(local->scan_sdata,
1289                                                 lockdep_is_held(&local->hw.wiphy->mtx)));
1290                 return;
1291         }
1292
1293         wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1294         /* and clean up */
1295         memset(&local->scan_info, 0, sizeof(local->scan_info));
1296         __ieee80211_scan_completed(&local->hw, true);
1297 }
1298
1299 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1300                                         struct cfg80211_sched_scan_request *req)
1301 {
1302         struct ieee80211_local *local = sdata->local;
1303         struct ieee80211_scan_ies sched_scan_ies = {};
1304         struct cfg80211_chan_def chandef;
1305         int ret, i, iebufsz, num_bands = 0;
1306         u32 rate_masks[NUM_NL80211_BANDS] = {};
1307         u8 bands_used = 0;
1308         u8 *ie;
1309         u32 flags = 0;
1310
1311         lockdep_assert_wiphy(local->hw.wiphy);
1312
1313         iebufsz = local->scan_ies_len + req->ie_len;
1314
1315         if (!local->ops->sched_scan_start)
1316                 return -EOPNOTSUPP;
1317
1318         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1319                 if (local->hw.wiphy->bands[i]) {
1320                         bands_used |= BIT(i);
1321                         rate_masks[i] = (u32) -1;
1322                         num_bands++;
1323                 }
1324         }
1325
1326         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1327                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1328
1329         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1330         if (!ie) {
1331                 ret = -ENOMEM;
1332                 goto out;
1333         }
1334
1335         ieee80211_prepare_scan_chandef(&chandef);
1336
1337         ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1338                                        &sched_scan_ies, req->ie,
1339                                        req->ie_len, bands_used, rate_masks,
1340                                        &chandef, flags);
1341         if (ret < 0)
1342                 goto error;
1343
1344         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1345         if (ret == 0) {
1346                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1347                 rcu_assign_pointer(local->sched_scan_req, req);
1348         }
1349
1350 error:
1351         kfree(ie);
1352 out:
1353         if (ret) {
1354                 /* Clean in case of failure after HW restart or upon resume. */
1355                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1356                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1357         }
1358
1359         return ret;
1360 }
1361
1362 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1363                                        struct cfg80211_sched_scan_request *req)
1364 {
1365         struct ieee80211_local *local = sdata->local;
1366
1367         lockdep_assert_wiphy(local->hw.wiphy);
1368
1369         if (rcu_access_pointer(local->sched_scan_sdata))
1370                 return -EBUSY;
1371
1372         return __ieee80211_request_sched_scan_start(sdata, req);
1373 }
1374
1375 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1376 {
1377         struct ieee80211_sub_if_data *sched_scan_sdata;
1378         int ret = -ENOENT;
1379
1380         lockdep_assert_wiphy(local->hw.wiphy);
1381
1382         if (!local->ops->sched_scan_stop)
1383                 return -EOPNOTSUPP;
1384
1385         /* We don't want to restart sched scan anymore. */
1386         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1387
1388         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1389                                                 lockdep_is_held(&local->hw.wiphy->mtx));
1390         if (sched_scan_sdata) {
1391                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1392                 if (!ret)
1393                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1394         }
1395
1396         return ret;
1397 }
1398
1399 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1400 {
1401         struct ieee80211_local *local = hw_to_local(hw);
1402
1403         trace_api_sched_scan_results(local);
1404
1405         cfg80211_sched_scan_results(hw->wiphy, 0);
1406 }
1407 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1408
1409 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1410 {
1411         lockdep_assert_wiphy(local->hw.wiphy);
1412
1413         if (!rcu_access_pointer(local->sched_scan_sdata))
1414                 return;
1415
1416         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1417
1418         /* If sched scan was aborted by the driver. */
1419         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1420
1421         cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1422 }
1423
1424 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1425                                        struct wiphy_work *work)
1426 {
1427         struct ieee80211_local *local =
1428                 container_of(work, struct ieee80211_local,
1429                              sched_scan_stopped_work);
1430
1431         ieee80211_sched_scan_end(local);
1432 }
1433
1434 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1435 {
1436         struct ieee80211_local *local = hw_to_local(hw);
1437
1438         trace_api_sched_scan_stopped(local);
1439
1440         /*
1441          * this shouldn't really happen, so for simplicity
1442          * simply ignore it, and let mac80211 reconfigure
1443          * the sched scan later on.
1444          */
1445         if (local->in_reconfig)
1446                 return;
1447
1448         wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1449 }
1450 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);