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) 2018-2024 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, n_chans;
 362         u32 flags = 0;
 363
 364         req = rcu_dereference_protected(local->scan_req,
 365                                         lockdep_is_held(&local->hw.wiphy->mtx));
 366
 367         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 368                 return false;
 369
 370         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 371                 for (i = 0; i < req->n_channels; i++) {
 372                         local->hw_scan_req->req.channels[i] = req->channels[i];
 373                         bands_used |= BIT(req->channels[i]->band);
 374                 }
 375
 376                 n_chans = req->n_channels;
 377         } else {
 378                 do {
 379                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 380                                 return false;
 381
 382                         n_chans = 0;
 383
 384                         for (i = 0; i < req->n_channels; i++) {
 385                                 if (req->channels[i]->band !=
 386                                     local->hw_scan_band)
 387                                         continue;
 388                                 local->hw_scan_req->req.channels[n_chans] =
 389                                                         req->channels[i];
 390                                 n_chans++;
 391                                 bands_used |= BIT(req->channels[i]->band);
 392                         }
 393
 394                         local->hw_scan_band++;
 395                 } while (!n_chans);
 396         }
 397
 398         local->hw_scan_req->req.n_channels = n_chans;
 399         ieee80211_prepare_scan_chandef(&chandef);
 400
 401         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 402                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 403
 404         ielen = ieee80211_build_preq_ies(sdata,
 405                                          (u8 *)local->hw_scan_req->req.ie,
 406                                          local->hw_scan_ies_bufsize,
 407                                          &local->hw_scan_req->ies,
 408                                          req->ie, req->ie_len,
 409                                          bands_used, req->rates, &chandef,
 410                                          flags);
 411         if (ielen < 0)
 412                 return false;
 413         local->hw_scan_req->req.ie_len = ielen;
 414         local->hw_scan_req->req.no_cck = req->no_cck;
 415         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 416         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 417                         req->mac_addr_mask);
 418         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 419
 420         return true;
 421 }
 422
 423 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 424 {
 425         struct ieee80211_local *local = hw_to_local(hw);
 426         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 427         bool was_scanning = local->scanning;
 428         struct cfg80211_scan_request *scan_req;
 429         struct ieee80211_sub_if_data *scan_sdata;
 430         struct ieee80211_sub_if_data *sdata;
 431
 432         lockdep_assert_wiphy(local->hw.wiphy);
 433
 434         /*
 435          * It's ok to abort a not-yet-running scan (that
 436          * we have one at all will be verified by checking
 437          * local->scan_req next), but not to complete it
 438          * successfully.
 439          */
 440         if (WARN_ON(!local->scanning && !aborted))
 441                 aborted = true;
 442
 443         if (WARN_ON(!local->scan_req))
 444                 return;
 445
 446         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 447                                                lockdep_is_held(&local->hw.wiphy->mtx));
 448
 449         if (hw_scan && !aborted &&
 450             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 451             ieee80211_prep_hw_scan(scan_sdata)) {
 452                 int rc;
 453
 454                 rc = drv_hw_scan(local,
 455                         rcu_dereference_protected(local->scan_sdata,
 456                                                   lockdep_is_held(&local->hw.wiphy->mtx)),
 457                         local->hw_scan_req);
 458
 459                 if (rc == 0)
 460                         return;
 461
 462                 /* HW scan failed and is going to be reported as aborted,
 463                  * so clear old scan info.
 464                  */
 465                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 466                 aborted = true;
 467         }
 468
 469         kfree(local->hw_scan_req);
 470         local->hw_scan_req = NULL;
 471
 472         scan_req = rcu_dereference_protected(local->scan_req,
 473                                              lockdep_is_held(&local->hw.wiphy->mtx));
 474
 475         RCU_INIT_POINTER(local->scan_req, NULL);
 476         RCU_INIT_POINTER(local->scan_sdata, NULL);
 477
 478         local->scanning = 0;
 479         local->scan_chandef.chan = NULL;
 480
 481         synchronize_rcu();
 482
 483         if (scan_req != local->int_scan_req) {
 484                 local->scan_info.aborted = aborted;
 485                 cfg80211_scan_done(scan_req, &local->scan_info);
 486         }
 487
 488         /* Set power back to normal operating levels. */
 489         ieee80211_hw_conf_chan(local);
 490
 491         if (!hw_scan && was_scanning) {
 492                 ieee80211_configure_filter(local);
 493                 drv_sw_scan_complete(local, scan_sdata);
 494                 ieee80211_offchannel_return(local);
 495         }
 496
 497         ieee80211_recalc_idle(local);
 498
 499         ieee80211_mlme_notify_scan_completed(local);
 500         ieee80211_ibss_notify_scan_completed(local);
 501
 502         /* Requeue all the work that might have been ignored while
 503          * the scan was in progress; if there was none this will
 504          * just be a no-op for the particular interface.
 505          */
 506         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 507                 if (ieee80211_sdata_running(sdata))
 508                         wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
 509         }
 510
 511         if (was_scanning)
 512                 ieee80211_start_next_roc(local);
 513 }
 514
 515 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 516                               struct cfg80211_scan_info *info)
 517 {
 518         struct ieee80211_local *local = hw_to_local(hw);
 519
 520         trace_api_scan_completed(local, info->aborted);
 521
 522         set_bit(SCAN_COMPLETED, &local->scanning);
 523         if (info->aborted)
 524                 set_bit(SCAN_ABORTED, &local->scanning);
 525
 526         memcpy(&local->scan_info, info, sizeof(*info));
 527
 528         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 529 }
 530 EXPORT_SYMBOL(ieee80211_scan_completed);
 531
 532 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 533                                    struct ieee80211_sub_if_data *sdata)
 534 {
 535         /* Software scan is not supported in multi-channel cases */
 536         if (!local->emulate_chanctx)
 537                 return -EOPNOTSUPP;
 538
 539         /*
 540          * Hardware/driver doesn't support hw_scan, so use software
 541          * scanning instead. First send a nullfunc frame with power save
 542          * bit on so that AP will buffer the frames for us while we are not
 543          * listening, then send probe requests to each channel and wait for
 544          * the responses. After all channels are scanned, tune back to the
 545          * original channel and send a nullfunc frame with power save bit
 546          * off to trigger the AP to send us all the buffered frames.
 547          *
 548          * Note that while local->sw_scanning is true everything else but
 549          * nullfunc frames and probe requests will be dropped in
 550          * ieee80211_tx_h_check_assoc().
 551          */
 552         drv_sw_scan_start(local, sdata, local->scan_addr);
 553
 554         local->leave_oper_channel_time = jiffies;
 555         local->next_scan_state = SCAN_DECISION;
 556         local->scan_channel_idx = 0;
 557
 558         ieee80211_offchannel_stop_vifs(local);
 559
 560         /* ensure nullfunc is transmitted before leaving operating channel */
 561         ieee80211_flush_queues(local, NULL, false);
 562
 563         ieee80211_configure_filter(local);
 564
 565         /* We need to set power level at maximum rate for scanning. */
 566         ieee80211_hw_conf_chan(local);
 567
 568         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 569
 570         return 0;
 571 }
 572
 573 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 574 {
 575         struct ieee80211_local *local = sdata->local;
 576         struct ieee80211_sub_if_data *sdata_iter;
 577
 578         lockdep_assert_wiphy(local->hw.wiphy);
 579
 580         if (!ieee80211_is_radar_required(local))
 581                 return true;
 582
 583         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 584                 return false;
 585
 586         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 587                 if (sdata_iter->wdev.cac_started)
 588                         return false;
 589         }
 590
 591         return true;
 592 }
 593
 594 static bool ieee80211_can_scan(struct ieee80211_local *local,
 595                                struct ieee80211_sub_if_data *sdata)
 596 {
 597         if (!__ieee80211_can_leave_ch(sdata))
 598                 return false;
 599
 600         if (!list_empty(&local->roc_list))
 601                 return false;
 602
 603         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 604             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 605                 return false;
 606
 607         return true;
 608 }
 609
 610 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 611 {
 612         lockdep_assert_wiphy(local->hw.wiphy);
 613
 614         if (!local->scan_req || local->scanning)
 615                 return;
 616
 617         if (!ieee80211_can_scan(local,
 618                                 rcu_dereference_protected(
 619                                         local->scan_sdata,
 620                                         lockdep_is_held(&local->hw.wiphy->mtx))))
 621                 return;
 622
 623         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 624                                  round_jiffies_relative(0));
 625 }
 626
 627 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 628                                           const u8 *src, const u8 *dst,
 629                                           const u8 *ssid, size_t ssid_len,
 630                                           const u8 *ie, size_t ie_len,
 631                                           u32 ratemask, u32 flags, u32 tx_flags,
 632                                           struct ieee80211_channel *channel)
 633 {
 634         struct sk_buff *skb;
 635
 636         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 637                                         ssid, ssid_len,
 638                                         ie, ie_len, flags);
 639
 640         if (skb) {
 641                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 642                         struct ieee80211_hdr *hdr = (void *)skb->data;
 643                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 644                         u16 sn = get_random_u16();
 645
 646                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 647                         hdr->seq_ctrl =
 648                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 649                 }
 650                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 651                 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_SCAN_TX;
 652                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 653         }
 654 }
 655
 656 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 657                                             unsigned long *next_delay)
 658 {
 659         int i;
 660         struct ieee80211_sub_if_data *sdata;
 661         struct cfg80211_scan_request *scan_req;
 662         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 663         u32 flags = 0, tx_flags;
 664
 665         scan_req = rcu_dereference_protected(local->scan_req,
 666                                              lockdep_is_held(&local->hw.wiphy->mtx));
 667
 668         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 669         if (scan_req->no_cck)
 670                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 671         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 672                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 673         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 674                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 675
 676         sdata = rcu_dereference_protected(local->scan_sdata,
 677                                           lockdep_is_held(&local->hw.wiphy->mtx));
 678
 679         for (i = 0; i < scan_req->n_ssids; i++)
 680                 ieee80211_send_scan_probe_req(
 681                         sdata, local->scan_addr, scan_req->bssid,
 682                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 683                         scan_req->ie, scan_req->ie_len,
 684                         scan_req->rates[band], flags,
 685                         tx_flags, local->hw.conf.chandef.chan);
 686
 687         /*
 688          * After sending probe requests, wait for probe responses
 689          * on the channel.
 690          */
 691         *next_delay = msecs_to_jiffies(scan_req->duration) >
 692                       IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
 693                       msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
 694                       IEEE80211_CHANNEL_TIME;
 695         local->next_scan_state = SCAN_DECISION;
 696 }
 697
 698 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 699                                   struct cfg80211_scan_request *req)
 700 {
 701         struct ieee80211_local *local = sdata->local;
 702         bool hw_scan = local->ops->hw_scan;
 703         int rc;
 704
 705         lockdep_assert_wiphy(local->hw.wiphy);
 706
 707         if (local->scan_req)
 708                 return -EBUSY;
 709
 710         /* For an MLO connection, if a link ID was specified, validate that it
 711          * is indeed active. If no link ID was specified, select one of the
 712          * active links.
 713          */
 714         if (ieee80211_vif_is_mld(&sdata->vif)) {
 715                 if (req->tsf_report_link_id >= 0) {
 716                         if (!(sdata->vif.active_links &
 717                               BIT(req->tsf_report_link_id)))
 718                                 return -EINVAL;
 719                 } else {
 720                         req->tsf_report_link_id =
 721                                 __ffs(sdata->vif.active_links);
 722                 }
 723         }
 724
 725         if (!__ieee80211_can_leave_ch(sdata))
 726                 return -EBUSY;
 727
 728         if (!ieee80211_can_scan(local, sdata)) {
 729                 /* wait for the work to finish/time out */
 730                 rcu_assign_pointer(local->scan_req, req);
 731                 rcu_assign_pointer(local->scan_sdata, sdata);
 732                 return 0;
 733         }
 734
 735  again:
 736         if (hw_scan) {
 737                 u8 *ies;
 738
 739                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 740
 741                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 742                         int i, n_bands = 0;
 743                         u8 bands_counted = 0;
 744
 745                         for (i = 0; i < req->n_channels; i++) {
 746                                 if (bands_counted & BIT(req->channels[i]->band))
 747                                         continue;
 748                                 bands_counted |= BIT(req->channels[i]->band);
 749                                 n_bands++;
 750                         }
 751
 752                         local->hw_scan_ies_bufsize *= n_bands;
 753                 }
 754
 755                 local->hw_scan_req = kmalloc(
 756                                 sizeof(*local->hw_scan_req) +
 757                                 req->n_channels * sizeof(req->channels[0]) +
 758                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 759                 if (!local->hw_scan_req)
 760                         return -ENOMEM;
 761
 762                 local->hw_scan_req->req.ssids = req->ssids;
 763                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 764                 ies = (u8 *)local->hw_scan_req +
 765                         sizeof(*local->hw_scan_req) +
 766                         req->n_channels * sizeof(req->channels[0]);
 767                 local->hw_scan_req->req.ie = ies;
 768                 local->hw_scan_req->req.flags = req->flags;
 769                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 770                 local->hw_scan_req->req.duration = req->duration;
 771                 local->hw_scan_req->req.duration_mandatory =
 772                         req->duration_mandatory;
 773                 local->hw_scan_req->req.tsf_report_link_id =
 774                         req->tsf_report_link_id;
 775
 776                 local->hw_scan_band = 0;
 777                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 778                 local->hw_scan_req->req.scan_6ghz_params =
 779                         req->scan_6ghz_params;
 780                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 781
 782                 /*
 783                  * After allocating local->hw_scan_req, we must
 784                  * go through until ieee80211_prep_hw_scan(), so
 785                  * anything that might be changed here and leave
 786                  * this function early must not go after this
 787                  * allocation.
 788                  */
 789         }
 790
 791         rcu_assign_pointer(local->scan_req, req);
 792         rcu_assign_pointer(local->scan_sdata, sdata);
 793
 794         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 795                 get_random_mask_addr(local->scan_addr,
 796                                      req->mac_addr,
 797                                      req->mac_addr_mask);
 798         else
 799                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 800
 801         if (hw_scan) {
 802                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 803         } else if ((req->n_channels == 1) &&
 804                    (req->channels[0] == local->hw.conf.chandef.chan)) {
 805                 /*
 806                  * If we are scanning only on the operating channel
 807                  * then we do not need to stop normal activities
 808                  */
 809                 unsigned long next_delay;
 810
 811                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 812
 813                 ieee80211_recalc_idle(local);
 814
 815                 /* Notify driver scan is starting, keep order of operations
 816                  * same as normal software scan, in case that matters. */
 817                 drv_sw_scan_start(local, sdata, local->scan_addr);
 818
 819                 ieee80211_configure_filter(local); /* accept probe-responses */
 820
 821                 /* We need to ensure power level is at max for scanning. */
 822                 ieee80211_hw_conf_chan(local);
 823
 824                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 825                                                 IEEE80211_CHAN_RADAR)) ||
 826                     !req->n_ssids) {
 827                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 828                         if (req->n_ssids)
 829                                 set_bit(SCAN_BEACON_WAIT, &local->scanning);
 830                 } else {
 831                         ieee80211_scan_state_send_probe(local, &next_delay);
 832                         next_delay = IEEE80211_CHANNEL_TIME;
 833                 }
 834
 835                 /* Now, just wait a bit and we are all done! */
 836                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 837                                          next_delay);
 838                 return 0;
 839         } else {
 840                 /* Do normal software scan */
 841                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 842         }
 843
 844         ieee80211_recalc_idle(local);
 845
 846         if (hw_scan) {
 847                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 848                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 849         } else {
 850                 rc = ieee80211_start_sw_scan(local, sdata);
 851         }
 852
 853         if (rc) {
 854                 kfree(local->hw_scan_req);
 855                 local->hw_scan_req = NULL;
 856                 local->scanning = 0;
 857
 858                 ieee80211_recalc_idle(local);
 859
 860                 local->scan_req = NULL;
 861                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 862         }
 863
 864         if (hw_scan && rc == 1) {
 865                 /*
 866                  * we can't fall back to software for P2P-GO
 867                  * as it must update NoA etc.
 868                  */
 869                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 870                                 NL80211_IFTYPE_P2P_GO)
 871                         return -EOPNOTSUPP;
 872                 hw_scan = false;
 873                 goto again;
 874         }
 875
 876         return rc;
 877 }
 878
 879 static unsigned long
 880 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 881 {
 882         /*
 883          * TODO: channel switching also consumes quite some time,
 884          * add that delay as well to get a better estimation
 885          */
 886         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 887                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 888         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 889 }
 890
 891 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 892                                           unsigned long *next_delay)
 893 {
 894         bool associated = false;
 895         bool tx_empty = true;
 896         bool bad_latency;
 897         struct ieee80211_sub_if_data *sdata;
 898         struct ieee80211_channel *next_chan;
 899         enum mac80211_scan_state next_scan_state;
 900         struct cfg80211_scan_request *scan_req;
 901
 902         lockdep_assert_wiphy(local->hw.wiphy);
 903
 904         /*
 905          * check if at least one STA interface is associated,
 906          * check if at least one STA interface has pending tx frames
 907          * and grab the lowest used beacon interval
 908          */
 909         list_for_each_entry(sdata, &local->interfaces, list) {
 910                 if (!ieee80211_sdata_running(sdata))
 911                         continue;
 912
 913                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 914                         if (sdata->u.mgd.associated) {
 915                                 associated = true;
 916
 917                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 918                                         tx_empty = false;
 919                                         break;
 920                                 }
 921                         }
 922                 }
 923         }
 924
 925         scan_req = rcu_dereference_protected(local->scan_req,
 926                                              lockdep_is_held(&local->hw.wiphy->mtx));
 927
 928         next_chan = scan_req->channels[local->scan_channel_idx];
 929
 930         /*
 931          * we're currently scanning a different channel, let's
 932          * see if we can scan another channel without interfering
 933          * with the current traffic situation.
 934          *
 935          * Keep good latency, do not stay off-channel more than 125 ms.
 936          */
 937
 938         bad_latency = time_after(jiffies +
 939                                  ieee80211_scan_get_channel_time(next_chan),
 940                                  local->leave_oper_channel_time + HZ / 8);
 941
 942         if (associated && !tx_empty) {
 943                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 944                         next_scan_state = SCAN_ABORT;
 945                 else
 946                         next_scan_state = SCAN_SUSPEND;
 947         } else if (associated && bad_latency) {
 948                 next_scan_state = SCAN_SUSPEND;
 949         } else {
 950                 next_scan_state = SCAN_SET_CHANNEL;
 951         }
 952
 953         local->next_scan_state = next_scan_state;
 954
 955         *next_delay = 0;
 956 }
 957
 958 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 959                                              unsigned long *next_delay)
 960 {
 961         int skip;
 962         struct ieee80211_channel *chan;
 963         struct cfg80211_scan_request *scan_req;
 964
 965         scan_req = rcu_dereference_protected(local->scan_req,
 966                                              lockdep_is_held(&local->hw.wiphy->mtx));
 967
 968         skip = 0;
 969         chan = scan_req->channels[local->scan_channel_idx];
 970
 971         local->scan_chandef.chan = chan;
 972         local->scan_chandef.center_freq1 = chan->center_freq;
 973         local->scan_chandef.freq1_offset = chan->freq_offset;
 974         local->scan_chandef.center_freq2 = 0;
 975
 976         /* For scanning on the S1G band, detect the channel width according to
 977          * the channel being scanned.
 978          */
 979         if (chan->band == NL80211_BAND_S1GHZ) {
 980                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 981                 goto set_channel;
 982         }
 983
 984         /* If scanning on oper channel, use whatever channel-type
 985          * is currently in use.
 986          */
 987         if (chan == local->hw.conf.chandef.chan)
 988                 local->scan_chandef = local->hw.conf.chandef;
 989         else
 990                 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 991
 992 set_channel:
 993         if (ieee80211_hw_conf_chan(local))
 994                 skip = 1;
 995
 996         /* advance state machine to next channel/band */
 997         local->scan_channel_idx++;
 998
 999         if (skip) {
1000                 /* if we skip this channel return to the decision state */
1001                 local->next_scan_state = SCAN_DECISION;
1002                 return;
1003         }
1004
1005         /*
1006          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1007          * (which unfortunately doesn't say _why_ step a) is done,
1008          * but it waits for the probe delay or until a frame is
1009          * received - and the received frame would update the NAV).
1010          * For now, we do not support waiting until a frame is
1011          * received.
1012          *
1013          * In any case, it is not necessary for a passive scan.
1014          */
1015         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1016             !scan_req->n_ssids) {
1017                 *next_delay = msecs_to_jiffies(scan_req->duration) >
1018                               IEEE80211_PASSIVE_CHANNEL_TIME ?
1019                               msecs_to_jiffies(scan_req->duration) :
1020                               IEEE80211_PASSIVE_CHANNEL_TIME;
1021                 local->next_scan_state = SCAN_DECISION;
1022                 if (scan_req->n_ssids)
1023                         set_bit(SCAN_BEACON_WAIT, &local->scanning);
1024                 return;
1025         }
1026
1027         /* active scan, send probes */
1028         *next_delay = IEEE80211_PROBE_DELAY;
1029         local->next_scan_state = SCAN_SEND_PROBE;
1030 }
1031
1032 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1033                                          unsigned long *next_delay)
1034 {
1035         /* switch back to the operating channel */
1036         local->scan_chandef.chan = NULL;
1037         ieee80211_hw_conf_chan(local);
1038
1039         /* disable PS */
1040         ieee80211_offchannel_return(local);
1041
1042         *next_delay = HZ / 5;
1043         /* afterwards, resume scan & go to next channel */
1044         local->next_scan_state = SCAN_RESUME;
1045 }
1046
1047 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1048                                         unsigned long *next_delay)
1049 {
1050         ieee80211_offchannel_stop_vifs(local);
1051
1052         if (local->ops->flush) {
1053                 ieee80211_flush_queues(local, NULL, false);
1054                 *next_delay = 0;
1055         } else
1056                 *next_delay = HZ / 10;
1057
1058         /* remember when we left the operating channel */
1059         local->leave_oper_channel_time = jiffies;
1060
1061         /* advance to the next channel to be scanned */
1062         local->next_scan_state = SCAN_SET_CHANNEL;
1063 }
1064
1065 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1066 {
1067         struct ieee80211_local *local =
1068                 container_of(work, struct ieee80211_local, scan_work.work);
1069         struct ieee80211_sub_if_data *sdata;
1070         struct cfg80211_scan_request *scan_req;
1071         unsigned long next_delay = 0;
1072         bool aborted;
1073
1074         lockdep_assert_wiphy(local->hw.wiphy);
1075
1076         if (!ieee80211_can_run_worker(local)) {
1077                 aborted = true;
1078                 goto out_complete;
1079         }
1080
1081         sdata = rcu_dereference_protected(local->scan_sdata,
1082                                           lockdep_is_held(&local->hw.wiphy->mtx));
1083         scan_req = rcu_dereference_protected(local->scan_req,
1084                                              lockdep_is_held(&local->hw.wiphy->mtx));
1085
1086         /* When scanning on-channel, the first-callback means completed. */
1087         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1088                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1089                 goto out_complete;
1090         }
1091
1092         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1093                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1094                 goto out_complete;
1095         }
1096
1097         if (!sdata || !scan_req)
1098                 return;
1099
1100         if (!local->scanning) {
1101                 int rc;
1102
1103                 RCU_INIT_POINTER(local->scan_req, NULL);
1104                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1105
1106                 rc = __ieee80211_start_scan(sdata, scan_req);
1107                 if (!rc)
1108                         return;
1109                 /* need to complete scan in cfg80211 */
1110                 rcu_assign_pointer(local->scan_req, scan_req);
1111                 aborted = true;
1112                 goto out_complete;
1113         }
1114
1115         clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1116
1117         /*
1118          * as long as no delay is required advance immediately
1119          * without scheduling a new work
1120          */
1121         do {
1122                 if (!ieee80211_sdata_running(sdata)) {
1123                         aborted = true;
1124                         goto out_complete;
1125                 }
1126
1127                 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1128                     local->next_scan_state == SCAN_DECISION)
1129                         local->next_scan_state = SCAN_SEND_PROBE;
1130
1131                 switch (local->next_scan_state) {
1132                 case SCAN_DECISION:
1133                         /* if no more bands/channels left, complete scan */
1134                         if (local->scan_channel_idx >= scan_req->n_channels) {
1135                                 aborted = false;
1136                                 goto out_complete;
1137                         }
1138                         ieee80211_scan_state_decision(local, &next_delay);
1139                         break;
1140                 case SCAN_SET_CHANNEL:
1141                         ieee80211_scan_state_set_channel(local, &next_delay);
1142                         break;
1143                 case SCAN_SEND_PROBE:
1144                         ieee80211_scan_state_send_probe(local, &next_delay);
1145                         break;
1146                 case SCAN_SUSPEND:
1147                         ieee80211_scan_state_suspend(local, &next_delay);
1148                         break;
1149                 case SCAN_RESUME:
1150                         ieee80211_scan_state_resume(local, &next_delay);
1151                         break;
1152                 case SCAN_ABORT:
1153                         aborted = true;
1154                         goto out_complete;
1155                 }
1156         } while (next_delay == 0);
1157
1158         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1159                                  next_delay);
1160         return;
1161
1162 out_complete:
1163         __ieee80211_scan_completed(&local->hw, aborted);
1164 }
1165
1166 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1167                            struct cfg80211_scan_request *req)
1168 {
1169         lockdep_assert_wiphy(sdata->local->hw.wiphy);
1170
1171         return __ieee80211_start_scan(sdata, req);
1172 }
1173
1174 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1175                                 const u8 *ssid, u8 ssid_len,
1176                                 struct ieee80211_channel **channels,
1177                                 unsigned int n_channels)
1178 {
1179         struct ieee80211_local *local = sdata->local;
1180         int ret = -EBUSY, i, n_ch = 0;
1181         enum nl80211_band band;
1182
1183         lockdep_assert_wiphy(local->hw.wiphy);
1184
1185         /* busy scanning */
1186         if (local->scan_req)
1187                 goto unlock;
1188
1189         /* fill internal scan request */
1190         if (!channels) {
1191                 int max_n;
1192
1193                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1194                         if (!local->hw.wiphy->bands[band] ||
1195                             band == NL80211_BAND_6GHZ)
1196                                 continue;
1197
1198                         max_n = local->hw.wiphy->bands[band]->n_channels;
1199                         for (i = 0; i < max_n; i++) {
1200                                 struct ieee80211_channel *tmp_ch =
1201                                     &local->hw.wiphy->bands[band]->channels[i];
1202
1203                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1204                                                      IEEE80211_CHAN_DISABLED))
1205                                         continue;
1206
1207                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1208                                 n_ch++;
1209                         }
1210                 }
1211
1212                 if (WARN_ON_ONCE(n_ch == 0))
1213                         goto unlock;
1214
1215                 local->int_scan_req->n_channels = n_ch;
1216         } else {
1217                 for (i = 0; i < n_channels; i++) {
1218                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1219                                                   IEEE80211_CHAN_DISABLED))
1220                                 continue;
1221
1222                         local->int_scan_req->channels[n_ch] = channels[i];
1223                         n_ch++;
1224                 }
1225
1226                 if (WARN_ON_ONCE(n_ch == 0))
1227                         goto unlock;
1228
1229                 local->int_scan_req->n_channels = n_ch;
1230         }
1231
1232         local->int_scan_req->ssids = &local->scan_ssid;
1233         local->int_scan_req->n_ssids = 1;
1234         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1235         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1236
1237         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1238  unlock:
1239         return ret;
1240 }
1241
1242 void ieee80211_scan_cancel(struct ieee80211_local *local)
1243 {
1244         /* ensure a new scan cannot be queued */
1245         lockdep_assert_wiphy(local->hw.wiphy);
1246
1247         /*
1248          * We are canceling software scan, or deferred scan that was not
1249          * yet really started (see __ieee80211_start_scan ).
1250          *
1251          * Regarding hardware scan:
1252          * - we can not call  __ieee80211_scan_completed() as when
1253          *   SCAN_HW_SCANNING bit is set this function change
1254          *   local->hw_scan_req to operate on 5G band, what race with
1255          *   driver which can use local->hw_scan_req
1256          *
1257          * - we can not cancel scan_work since driver can schedule it
1258          *   by ieee80211_scan_completed(..., true) to finish scan
1259          *
1260          * Hence we only call the cancel_hw_scan() callback, but the low-level
1261          * driver is still responsible for calling ieee80211_scan_completed()
1262          * after the scan was completed/aborted.
1263          */
1264
1265         if (!local->scan_req)
1266                 return;
1267
1268         /*
1269          * We have a scan running and the driver already reported completion,
1270          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1271          * cancelled.
1272          */
1273         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1274             test_bit(SCAN_COMPLETED, &local->scanning)) {
1275                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1276                 return;
1277         }
1278
1279         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1280                 /*
1281                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1282                  * scan on another band.
1283                  */
1284                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1285                 if (local->ops->cancel_hw_scan)
1286                         drv_cancel_hw_scan(local,
1287                                 rcu_dereference_protected(local->scan_sdata,
1288                                                 lockdep_is_held(&local->hw.wiphy->mtx)));
1289                 return;
1290         }
1291
1292         wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1293         /* and clean up */
1294         memset(&local->scan_info, 0, sizeof(local->scan_info));
1295         __ieee80211_scan_completed(&local->hw, true);
1296 }
1297
1298 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1299                                         struct cfg80211_sched_scan_request *req)
1300 {
1301         struct ieee80211_local *local = sdata->local;
1302         struct ieee80211_scan_ies sched_scan_ies = {};
1303         struct cfg80211_chan_def chandef;
1304         int ret, i, iebufsz, num_bands = 0;
1305         u32 rate_masks[NUM_NL80211_BANDS] = {};
1306         u8 bands_used = 0;
1307         u8 *ie;
1308         u32 flags = 0;
1309
1310         lockdep_assert_wiphy(local->hw.wiphy);
1311
1312         iebufsz = local->scan_ies_len + req->ie_len;
1313
1314         if (!local->ops->sched_scan_start)
1315                 return -EOPNOTSUPP;
1316
1317         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1318                 if (local->hw.wiphy->bands[i]) {
1319                         bands_used |= BIT(i);
1320                         rate_masks[i] = (u32) -1;
1321                         num_bands++;
1322                 }
1323         }
1324
1325         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1326                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1327
1328         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1329         if (!ie) {
1330                 ret = -ENOMEM;
1331                 goto out;
1332         }
1333
1334         ieee80211_prepare_scan_chandef(&chandef);
1335
1336         ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1337                                        &sched_scan_ies, req->ie,
1338                                        req->ie_len, bands_used, rate_masks,
1339                                        &chandef, flags);
1340         if (ret < 0)
1341                 goto error;
1342
1343         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1344         if (ret == 0) {
1345                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1346                 rcu_assign_pointer(local->sched_scan_req, req);
1347         }
1348
1349 error:
1350         kfree(ie);
1351 out:
1352         if (ret) {
1353                 /* Clean in case of failure after HW restart or upon resume. */
1354                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1355                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1356         }
1357
1358         return ret;
1359 }
1360
1361 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1362                                        struct cfg80211_sched_scan_request *req)
1363 {
1364         struct ieee80211_local *local = sdata->local;
1365
1366         lockdep_assert_wiphy(local->hw.wiphy);
1367
1368         if (rcu_access_pointer(local->sched_scan_sdata))
1369                 return -EBUSY;
1370
1371         return __ieee80211_request_sched_scan_start(sdata, req);
1372 }
1373
1374 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1375 {
1376         struct ieee80211_sub_if_data *sched_scan_sdata;
1377         int ret = -ENOENT;
1378
1379         lockdep_assert_wiphy(local->hw.wiphy);
1380
1381         if (!local->ops->sched_scan_stop)
1382                 return -EOPNOTSUPP;
1383
1384         /* We don't want to restart sched scan anymore. */
1385         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1386
1387         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1388                                                 lockdep_is_held(&local->hw.wiphy->mtx));
1389         if (sched_scan_sdata) {
1390                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1391                 if (!ret)
1392                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1393         }
1394
1395         return ret;
1396 }
1397
1398 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1399 {
1400         struct ieee80211_local *local = hw_to_local(hw);
1401
1402         trace_api_sched_scan_results(local);
1403
1404         cfg80211_sched_scan_results(hw->wiphy, 0);
1405 }
1406 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1407
1408 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1409 {
1410         lockdep_assert_wiphy(local->hw.wiphy);
1411
1412         if (!rcu_access_pointer(local->sched_scan_sdata))
1413                 return;
1414
1415         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1416
1417         /* If sched scan was aborted by the driver. */
1418         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1419
1420         cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1421 }
1422
1423 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1424                                        struct wiphy_work *work)
1425 {
1426         struct ieee80211_local *local =
1427                 container_of(work, struct ieee80211_local,
1428                              sched_scan_stopped_work);
1429
1430         ieee80211_sched_scan_end(local);
1431 }
1432
1433 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1434 {
1435         struct ieee80211_local *local = hw_to_local(hw);
1436
1437         trace_api_sched_scan_stopped(local);
1438
1439         /*
1440          * this shouldn't really happen, so for simplicity
1441          * simply ignore it, and let mac80211 reconfigure
1442          * the sched scan later on.
1443          */
1444         if (local->in_reconfig)
1445                 return;
1446
1447         wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1448 }
1449 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);