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) 2018-2023 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                 bss_meta.parent_tsf =
 198                         ieee80211_calculate_rx_timestamp(local, rx_status,
 199                                                          len + FCS_LEN, 24);
 200                 ether_addr_copy(bss_meta.parent_bssid,
 201                                 scan_sdata->vif.bss_conf.bssid);
 202         }
 203         rcu_read_unlock();
 204
 205         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 206                                               mgmt, len, GFP_ATOMIC);
 207         if (!cbss)
 208                 return NULL;
 209
 210         /* In case the signal is invalid update the status */
 211         signal_valid = channel == cbss->channel;
 212         if (!signal_valid)
 213                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 214
 215         return (void *)cbss->priv;
 216 }
 217
 218 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 219                                         u32 scan_flags, const u8 *da)
 220 {
 221         if (!sdata)
 222                 return false;
 223         /* accept broadcast for OCE */
 224         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 225             is_broadcast_ether_addr(da))
 226                 return true;
 227         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 228                 return true;
 229         return ether_addr_equal(da, sdata->vif.addr);
 230 }
 231
 232 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 233 {
 234         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 235         struct ieee80211_sub_if_data *sdata1, *sdata2;
 236         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 237         struct ieee80211_bss *bss;
 238         struct ieee80211_channel *channel;
 239         size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 240                                       u.probe_resp.variable);
 241
 242         if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 243             !ieee80211_is_beacon(mgmt->frame_control) &&
 244             !ieee80211_is_s1g_beacon(mgmt->frame_control))
 245                 return;
 246
 247         if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 248                 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 249                         min_hdr_len = offsetof(struct ieee80211_ext,
 250                                                u.s1g_short_beacon.variable);
 251                 else
 252                         min_hdr_len = offsetof(struct ieee80211_ext,
 253                                                u.s1g_beacon);
 254         }
 255
 256         if (skb->len < min_hdr_len)
 257                 return;
 258
 259         sdata1 = rcu_dereference(local->scan_sdata);
 260         sdata2 = rcu_dereference(local->sched_scan_sdata);
 261
 262         if (likely(!sdata1 && !sdata2))
 263                 return;
 264
 265         if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
 266                 /*
 267                  * we were passive scanning because of radar/no-IR, but
 268                  * the beacon/proberesp rx gives us an opportunity to upgrade
 269                  * to active scan
 270                  */
 271                 set_bit(SCAN_BEACON_DONE, &local->scanning);
 272                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 273         }
 274
 275         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 276                 struct cfg80211_scan_request *scan_req;
 277                 struct cfg80211_sched_scan_request *sched_scan_req;
 278                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 279
 280                 scan_req = rcu_dereference(local->scan_req);
 281                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 282
 283                 if (scan_req)
 284                         scan_req_flags = scan_req->flags;
 285
 286                 if (sched_scan_req)
 287                         sched_scan_req_flags = sched_scan_req->flags;
 288
 289                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 290                  * unless scanning with randomised address
 291                  */
 292                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 293                                                  mgmt->da) &&
 294                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 295                                                  mgmt->da))
 296                         return;
 297         }
 298
 299         channel = ieee80211_get_channel_khz(local->hw.wiphy,
 300                                         ieee80211_rx_status_to_khz(rx_status));
 301
 302         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 303                 return;
 304
 305         bss = ieee80211_bss_info_update(local, rx_status,
 306                                         mgmt, skb->len,
 307                                         channel);
 308         if (bss)
 309                 ieee80211_rx_bss_put(local, bss);
 310 }
 311
 312 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
 313 {
 314         memset(chandef, 0, sizeof(*chandef));
 315
 316         chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 317 }
 318
 319 /* return false if no more work */
 320 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 321 {
 322         struct ieee80211_local *local = sdata->local;
 323         struct cfg80211_scan_request *req;
 324         struct cfg80211_chan_def chandef;
 325         u8 bands_used = 0;
 326         int i, ielen, n_chans;
 327         u32 flags = 0;
 328
 329         req = rcu_dereference_protected(local->scan_req,
 330                                         lockdep_is_held(&local->hw.wiphy->mtx));
 331
 332         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 333                 return false;
 334
 335         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 336                 for (i = 0; i < req->n_channels; i++) {
 337                         local->hw_scan_req->req.channels[i] = req->channels[i];
 338                         bands_used |= BIT(req->channels[i]->band);
 339                 }
 340
 341                 n_chans = req->n_channels;
 342         } else {
 343                 do {
 344                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 345                                 return false;
 346
 347                         n_chans = 0;
 348
 349                         for (i = 0; i < req->n_channels; i++) {
 350                                 if (req->channels[i]->band !=
 351                                     local->hw_scan_band)
 352                                         continue;
 353                                 local->hw_scan_req->req.channels[n_chans] =
 354                                                         req->channels[i];
 355                                 n_chans++;
 356                                 bands_used |= BIT(req->channels[i]->band);
 357                         }
 358
 359                         local->hw_scan_band++;
 360                 } while (!n_chans);
 361         }
 362
 363         local->hw_scan_req->req.n_channels = n_chans;
 364         ieee80211_prepare_scan_chandef(&chandef);
 365
 366         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 367                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 368
 369         ielen = ieee80211_build_preq_ies(sdata,
 370                                          (u8 *)local->hw_scan_req->req.ie,
 371                                          local->hw_scan_ies_bufsize,
 372                                          &local->hw_scan_req->ies,
 373                                          req->ie, req->ie_len,
 374                                          bands_used, req->rates, &chandef,
 375                                          flags);
 376         local->hw_scan_req->req.ie_len = ielen;
 377         local->hw_scan_req->req.no_cck = req->no_cck;
 378         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 379         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 380                         req->mac_addr_mask);
 381         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 382
 383         return true;
 384 }
 385
 386 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 387 {
 388         struct ieee80211_local *local = hw_to_local(hw);
 389         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 390         bool was_scanning = local->scanning;
 391         struct cfg80211_scan_request *scan_req;
 392         struct ieee80211_sub_if_data *scan_sdata;
 393         struct ieee80211_sub_if_data *sdata;
 394
 395         lockdep_assert_wiphy(local->hw.wiphy);
 396
 397         /*
 398          * It's ok to abort a not-yet-running scan (that
 399          * we have one at all will be verified by checking
 400          * local->scan_req next), but not to complete it
 401          * successfully.
 402          */
 403         if (WARN_ON(!local->scanning && !aborted))
 404                 aborted = true;
 405
 406         if (WARN_ON(!local->scan_req))
 407                 return;
 408
 409         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 410                                                lockdep_is_held(&local->hw.wiphy->mtx));
 411
 412         if (hw_scan && !aborted &&
 413             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 414             ieee80211_prep_hw_scan(scan_sdata)) {
 415                 int rc;
 416
 417                 rc = drv_hw_scan(local,
 418                         rcu_dereference_protected(local->scan_sdata,
 419                                                   lockdep_is_held(&local->hw.wiphy->mtx)),
 420                         local->hw_scan_req);
 421
 422                 if (rc == 0)
 423                         return;
 424
 425                 /* HW scan failed and is going to be reported as aborted,
 426                  * so clear old scan info.
 427                  */
 428                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 429                 aborted = true;
 430         }
 431
 432         kfree(local->hw_scan_req);
 433         local->hw_scan_req = NULL;
 434
 435         scan_req = rcu_dereference_protected(local->scan_req,
 436                                              lockdep_is_held(&local->hw.wiphy->mtx));
 437
 438         RCU_INIT_POINTER(local->scan_req, NULL);
 439         RCU_INIT_POINTER(local->scan_sdata, NULL);
 440
 441         local->scanning = 0;
 442         local->scan_chandef.chan = NULL;
 443
 444         synchronize_rcu();
 445
 446         if (scan_req != local->int_scan_req) {
 447                 local->scan_info.aborted = aborted;
 448                 cfg80211_scan_done(scan_req, &local->scan_info);
 449         }
 450
 451         /* Set power back to normal operating levels. */
 452         ieee80211_hw_config(local, 0);
 453
 454         if (!hw_scan && was_scanning) {
 455                 ieee80211_configure_filter(local);
 456                 drv_sw_scan_complete(local, scan_sdata);
 457                 ieee80211_offchannel_return(local);
 458         }
 459
 460         ieee80211_recalc_idle(local);
 461
 462         ieee80211_mlme_notify_scan_completed(local);
 463         ieee80211_ibss_notify_scan_completed(local);
 464
 465         /* Requeue all the work that might have been ignored while
 466          * the scan was in progress; if there was none this will
 467          * just be a no-op for the particular interface.
 468          */
 469         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 470                 if (ieee80211_sdata_running(sdata))
 471                         wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
 472         }
 473
 474         if (was_scanning)
 475                 ieee80211_start_next_roc(local);
 476 }
 477
 478 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 479                               struct cfg80211_scan_info *info)
 480 {
 481         struct ieee80211_local *local = hw_to_local(hw);
 482
 483         trace_api_scan_completed(local, info->aborted);
 484
 485         set_bit(SCAN_COMPLETED, &local->scanning);
 486         if (info->aborted)
 487                 set_bit(SCAN_ABORTED, &local->scanning);
 488
 489         memcpy(&local->scan_info, info, sizeof(*info));
 490
 491         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 492 }
 493 EXPORT_SYMBOL(ieee80211_scan_completed);
 494
 495 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 496                                    struct ieee80211_sub_if_data *sdata)
 497 {
 498         /* Software scan is not supported in multi-channel cases */
 499         if (local->use_chanctx)
 500                 return -EOPNOTSUPP;
 501
 502         /*
 503          * Hardware/driver doesn't support hw_scan, so use software
 504          * scanning instead. First send a nullfunc frame with power save
 505          * bit on so that AP will buffer the frames for us while we are not
 506          * listening, then send probe requests to each channel and wait for
 507          * the responses. After all channels are scanned, tune back to the
 508          * original channel and send a nullfunc frame with power save bit
 509          * off to trigger the AP to send us all the buffered frames.
 510          *
 511          * Note that while local->sw_scanning is true everything else but
 512          * nullfunc frames and probe requests will be dropped in
 513          * ieee80211_tx_h_check_assoc().
 514          */
 515         drv_sw_scan_start(local, sdata, local->scan_addr);
 516
 517         local->leave_oper_channel_time = jiffies;
 518         local->next_scan_state = SCAN_DECISION;
 519         local->scan_channel_idx = 0;
 520
 521         ieee80211_offchannel_stop_vifs(local);
 522
 523         /* ensure nullfunc is transmitted before leaving operating channel */
 524         ieee80211_flush_queues(local, NULL, false);
 525
 526         ieee80211_configure_filter(local);
 527
 528         /* We need to set power level at maximum rate for scanning. */
 529         ieee80211_hw_config(local, 0);
 530
 531         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 532
 533         return 0;
 534 }
 535
 536 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 537 {
 538         struct ieee80211_local *local = sdata->local;
 539         struct ieee80211_sub_if_data *sdata_iter;
 540
 541         lockdep_assert_wiphy(local->hw.wiphy);
 542
 543         if (!ieee80211_is_radar_required(local))
 544                 return true;
 545
 546         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 547                 return false;
 548
 549         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 550                 if (sdata_iter->wdev.cac_started)
 551                         return false;
 552         }
 553
 554         return true;
 555 }
 556
 557 static bool ieee80211_can_scan(struct ieee80211_local *local,
 558                                struct ieee80211_sub_if_data *sdata)
 559 {
 560         if (!__ieee80211_can_leave_ch(sdata))
 561                 return false;
 562
 563         if (!list_empty(&local->roc_list))
 564                 return false;
 565
 566         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 567             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 568                 return false;
 569
 570         return true;
 571 }
 572
 573 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 574 {
 575         lockdep_assert_wiphy(local->hw.wiphy);
 576
 577         if (!local->scan_req || local->scanning)
 578                 return;
 579
 580         if (!ieee80211_can_scan(local,
 581                                 rcu_dereference_protected(
 582                                         local->scan_sdata,
 583                                         lockdep_is_held(&local->hw.wiphy->mtx))))
 584                 return;
 585
 586         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 587                                  round_jiffies_relative(0));
 588 }
 589
 590 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 591                                           const u8 *src, const u8 *dst,
 592                                           const u8 *ssid, size_t ssid_len,
 593                                           const u8 *ie, size_t ie_len,
 594                                           u32 ratemask, u32 flags, u32 tx_flags,
 595                                           struct ieee80211_channel *channel)
 596 {
 597         struct sk_buff *skb;
 598
 599         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 600                                         ssid, ssid_len,
 601                                         ie, ie_len, flags);
 602
 603         if (skb) {
 604                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 605                         struct ieee80211_hdr *hdr = (void *)skb->data;
 606                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 607                         u16 sn = get_random_u16();
 608
 609                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 610                         hdr->seq_ctrl =
 611                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 612                 }
 613                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 614                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 615         }
 616 }
 617
 618 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 619                                             unsigned long *next_delay)
 620 {
 621         int i;
 622         struct ieee80211_sub_if_data *sdata;
 623         struct cfg80211_scan_request *scan_req;
 624         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 625         u32 flags = 0, tx_flags;
 626
 627         scan_req = rcu_dereference_protected(local->scan_req,
 628                                              lockdep_is_held(&local->hw.wiphy->mtx));
 629
 630         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 631         if (scan_req->no_cck)
 632                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 633         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 634                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 635         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 636                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 637
 638         sdata = rcu_dereference_protected(local->scan_sdata,
 639                                           lockdep_is_held(&local->hw.wiphy->mtx));
 640
 641         for (i = 0; i < scan_req->n_ssids; i++)
 642                 ieee80211_send_scan_probe_req(
 643                         sdata, local->scan_addr, scan_req->bssid,
 644                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 645                         scan_req->ie, scan_req->ie_len,
 646                         scan_req->rates[band], flags,
 647                         tx_flags, local->hw.conf.chandef.chan);
 648
 649         /*
 650          * After sending probe requests, wait for probe responses
 651          * on the channel.
 652          */
 653         *next_delay = IEEE80211_CHANNEL_TIME;
 654         local->next_scan_state = SCAN_DECISION;
 655 }
 656
 657 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 658                                   struct cfg80211_scan_request *req)
 659 {
 660         struct ieee80211_local *local = sdata->local;
 661         bool hw_scan = local->ops->hw_scan;
 662         int rc;
 663
 664         lockdep_assert_wiphy(local->hw.wiphy);
 665
 666         if (local->scan_req)
 667                 return -EBUSY;
 668
 669         if (!__ieee80211_can_leave_ch(sdata))
 670                 return -EBUSY;
 671
 672         if (!ieee80211_can_scan(local, sdata)) {
 673                 /* wait for the work to finish/time out */
 674                 rcu_assign_pointer(local->scan_req, req);
 675                 rcu_assign_pointer(local->scan_sdata, sdata);
 676                 return 0;
 677         }
 678
 679  again:
 680         if (hw_scan) {
 681                 u8 *ies;
 682
 683                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 684
 685                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 686                         int i, n_bands = 0;
 687                         u8 bands_counted = 0;
 688
 689                         for (i = 0; i < req->n_channels; i++) {
 690                                 if (bands_counted & BIT(req->channels[i]->band))
 691                                         continue;
 692                                 bands_counted |= BIT(req->channels[i]->band);
 693                                 n_bands++;
 694                         }
 695
 696                         local->hw_scan_ies_bufsize *= n_bands;
 697                 }
 698
 699                 local->hw_scan_req = kmalloc(
 700                                 sizeof(*local->hw_scan_req) +
 701                                 req->n_channels * sizeof(req->channels[0]) +
 702                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 703                 if (!local->hw_scan_req)
 704                         return -ENOMEM;
 705
 706                 local->hw_scan_req->req.ssids = req->ssids;
 707                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 708                 ies = (u8 *)local->hw_scan_req +
 709                         sizeof(*local->hw_scan_req) +
 710                         req->n_channels * sizeof(req->channels[0]);
 711                 local->hw_scan_req->req.ie = ies;
 712                 local->hw_scan_req->req.flags = req->flags;
 713                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 714                 local->hw_scan_req->req.duration = req->duration;
 715                 local->hw_scan_req->req.duration_mandatory =
 716                         req->duration_mandatory;
 717
 718                 local->hw_scan_band = 0;
 719                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 720                 local->hw_scan_req->req.scan_6ghz_params =
 721                         req->scan_6ghz_params;
 722                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 723
 724                 /*
 725                  * After allocating local->hw_scan_req, we must
 726                  * go through until ieee80211_prep_hw_scan(), so
 727                  * anything that might be changed here and leave
 728                  * this function early must not go after this
 729                  * allocation.
 730                  */
 731         }
 732
 733         rcu_assign_pointer(local->scan_req, req);
 734         rcu_assign_pointer(local->scan_sdata, sdata);
 735
 736         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 737                 get_random_mask_addr(local->scan_addr,
 738                                      req->mac_addr,
 739                                      req->mac_addr_mask);
 740         else
 741                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 742
 743         if (hw_scan) {
 744                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 745         } else if ((req->n_channels == 1) &&
 746                    (req->channels[0] == local->_oper_chandef.chan)) {
 747                 /*
 748                  * If we are scanning only on the operating channel
 749                  * then we do not need to stop normal activities
 750                  */
 751                 unsigned long next_delay;
 752
 753                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 754
 755                 ieee80211_recalc_idle(local);
 756
 757                 /* Notify driver scan is starting, keep order of operations
 758                  * same as normal software scan, in case that matters. */
 759                 drv_sw_scan_start(local, sdata, local->scan_addr);
 760
 761                 ieee80211_configure_filter(local); /* accept probe-responses */
 762
 763                 /* We need to ensure power level is at max for scanning. */
 764                 ieee80211_hw_config(local, 0);
 765
 766                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 767                                                 IEEE80211_CHAN_RADAR)) ||
 768                     !req->n_ssids) {
 769                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 770                         if (req->n_ssids)
 771                                 set_bit(SCAN_BEACON_WAIT, &local->scanning);
 772                 } else {
 773                         ieee80211_scan_state_send_probe(local, &next_delay);
 774                         next_delay = IEEE80211_CHANNEL_TIME;
 775                 }
 776
 777                 /* Now, just wait a bit and we are all done! */
 778                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 779                                          next_delay);
 780                 return 0;
 781         } else {
 782                 /* Do normal software scan */
 783                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 784         }
 785
 786         ieee80211_recalc_idle(local);
 787
 788         if (hw_scan) {
 789                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 790                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 791         } else {
 792                 rc = ieee80211_start_sw_scan(local, sdata);
 793         }
 794
 795         if (rc) {
 796                 kfree(local->hw_scan_req);
 797                 local->hw_scan_req = NULL;
 798                 local->scanning = 0;
 799
 800                 ieee80211_recalc_idle(local);
 801
 802                 local->scan_req = NULL;
 803                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 804         }
 805
 806         if (hw_scan && rc == 1) {
 807                 /*
 808                  * we can't fall back to software for P2P-GO
 809                  * as it must update NoA etc.
 810                  */
 811                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 812                                 NL80211_IFTYPE_P2P_GO)
 813                         return -EOPNOTSUPP;
 814                 hw_scan = false;
 815                 goto again;
 816         }
 817
 818         return rc;
 819 }
 820
 821 static unsigned long
 822 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 823 {
 824         /*
 825          * TODO: channel switching also consumes quite some time,
 826          * add that delay as well to get a better estimation
 827          */
 828         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 829                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 830         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 831 }
 832
 833 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 834                                           unsigned long *next_delay)
 835 {
 836         bool associated = false;
 837         bool tx_empty = true;
 838         bool bad_latency;
 839         struct ieee80211_sub_if_data *sdata;
 840         struct ieee80211_channel *next_chan;
 841         enum mac80211_scan_state next_scan_state;
 842         struct cfg80211_scan_request *scan_req;
 843
 844         lockdep_assert_wiphy(local->hw.wiphy);
 845
 846         /*
 847          * check if at least one STA interface is associated,
 848          * check if at least one STA interface has pending tx frames
 849          * and grab the lowest used beacon interval
 850          */
 851         list_for_each_entry(sdata, &local->interfaces, list) {
 852                 if (!ieee80211_sdata_running(sdata))
 853                         continue;
 854
 855                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 856                         if (sdata->u.mgd.associated) {
 857                                 associated = true;
 858
 859                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 860                                         tx_empty = false;
 861                                         break;
 862                                 }
 863                         }
 864                 }
 865         }
 866
 867         scan_req = rcu_dereference_protected(local->scan_req,
 868                                              lockdep_is_held(&local->hw.wiphy->mtx));
 869
 870         next_chan = scan_req->channels[local->scan_channel_idx];
 871
 872         /*
 873          * we're currently scanning a different channel, let's
 874          * see if we can scan another channel without interfering
 875          * with the current traffic situation.
 876          *
 877          * Keep good latency, do not stay off-channel more than 125 ms.
 878          */
 879
 880         bad_latency = time_after(jiffies +
 881                                  ieee80211_scan_get_channel_time(next_chan),
 882                                  local->leave_oper_channel_time + HZ / 8);
 883
 884         if (associated && !tx_empty) {
 885                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 886                         next_scan_state = SCAN_ABORT;
 887                 else
 888                         next_scan_state = SCAN_SUSPEND;
 889         } else if (associated && bad_latency) {
 890                 next_scan_state = SCAN_SUSPEND;
 891         } else {
 892                 next_scan_state = SCAN_SET_CHANNEL;
 893         }
 894
 895         local->next_scan_state = next_scan_state;
 896
 897         *next_delay = 0;
 898 }
 899
 900 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 901                                              unsigned long *next_delay)
 902 {
 903         int skip;
 904         struct ieee80211_channel *chan;
 905         struct cfg80211_scan_request *scan_req;
 906
 907         scan_req = rcu_dereference_protected(local->scan_req,
 908                                              lockdep_is_held(&local->hw.wiphy->mtx));
 909
 910         skip = 0;
 911         chan = scan_req->channels[local->scan_channel_idx];
 912
 913         local->scan_chandef.chan = chan;
 914         local->scan_chandef.center_freq1 = chan->center_freq;
 915         local->scan_chandef.freq1_offset = chan->freq_offset;
 916         local->scan_chandef.center_freq2 = 0;
 917
 918         /* For scanning on the S1G band, detect the channel width according to
 919          * the channel being scanned.
 920          */
 921         if (chan->band == NL80211_BAND_S1GHZ) {
 922                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 923                 goto set_channel;
 924         }
 925
 926         /* If scanning on oper channel, use whatever channel-type
 927          * is currently in use.
 928          */
 929         if (chan == local->_oper_chandef.chan)
 930                 local->scan_chandef = local->_oper_chandef;
 931         else
 932                 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 933
 934 set_channel:
 935         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 936                 skip = 1;
 937
 938         /* advance state machine to next channel/band */
 939         local->scan_channel_idx++;
 940
 941         if (skip) {
 942                 /* if we skip this channel return to the decision state */
 943                 local->next_scan_state = SCAN_DECISION;
 944                 return;
 945         }
 946
 947         /*
 948          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 949          * (which unfortunately doesn't say _why_ step a) is done,
 950          * but it waits for the probe delay or until a frame is
 951          * received - and the received frame would update the NAV).
 952          * For now, we do not support waiting until a frame is
 953          * received.
 954          *
 955          * In any case, it is not necessary for a passive scan.
 956          */
 957         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 958             !scan_req->n_ssids) {
 959                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 960                 local->next_scan_state = SCAN_DECISION;
 961                 if (scan_req->n_ssids)
 962                         set_bit(SCAN_BEACON_WAIT, &local->scanning);
 963                 return;
 964         }
 965
 966         /* active scan, send probes */
 967         *next_delay = IEEE80211_PROBE_DELAY;
 968         local->next_scan_state = SCAN_SEND_PROBE;
 969 }
 970
 971 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 972                                          unsigned long *next_delay)
 973 {
 974         /* switch back to the operating channel */
 975         local->scan_chandef.chan = NULL;
 976         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 977
 978         /* disable PS */
 979         ieee80211_offchannel_return(local);
 980
 981         *next_delay = HZ / 5;
 982         /* afterwards, resume scan & go to next channel */
 983         local->next_scan_state = SCAN_RESUME;
 984 }
 985
 986 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
 987                                         unsigned long *next_delay)
 988 {
 989         ieee80211_offchannel_stop_vifs(local);
 990
 991         if (local->ops->flush) {
 992                 ieee80211_flush_queues(local, NULL, false);
 993                 *next_delay = 0;
 994         } else
 995                 *next_delay = HZ / 10;
 996
 997         /* remember when we left the operating channel */
 998         local->leave_oper_channel_time = jiffies;
 999
1000         /* advance to the next channel to be scanned */
1001         local->next_scan_state = SCAN_SET_CHANNEL;
1002 }
1003
1004 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1005 {
1006         struct ieee80211_local *local =
1007                 container_of(work, struct ieee80211_local, scan_work.work);
1008         struct ieee80211_sub_if_data *sdata;
1009         struct cfg80211_scan_request *scan_req;
1010         unsigned long next_delay = 0;
1011         bool aborted;
1012
1013         lockdep_assert_wiphy(local->hw.wiphy);
1014
1015         if (!ieee80211_can_run_worker(local)) {
1016                 aborted = true;
1017                 goto out_complete;
1018         }
1019
1020         sdata = rcu_dereference_protected(local->scan_sdata,
1021                                           lockdep_is_held(&local->hw.wiphy->mtx));
1022         scan_req = rcu_dereference_protected(local->scan_req,
1023                                              lockdep_is_held(&local->hw.wiphy->mtx));
1024
1025         /* When scanning on-channel, the first-callback means completed. */
1026         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1027                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1028                 goto out_complete;
1029         }
1030
1031         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1032                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1033                 goto out_complete;
1034         }
1035
1036         if (!sdata || !scan_req)
1037                 return;
1038
1039         if (!local->scanning) {
1040                 int rc;
1041
1042                 RCU_INIT_POINTER(local->scan_req, NULL);
1043                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1044
1045                 rc = __ieee80211_start_scan(sdata, scan_req);
1046                 if (!rc)
1047                         return;
1048                 /* need to complete scan in cfg80211 */
1049                 rcu_assign_pointer(local->scan_req, scan_req);
1050                 aborted = true;
1051                 goto out_complete;
1052         }
1053
1054         clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1055
1056         /*
1057          * as long as no delay is required advance immediately
1058          * without scheduling a new work
1059          */
1060         do {
1061                 if (!ieee80211_sdata_running(sdata)) {
1062                         aborted = true;
1063                         goto out_complete;
1064                 }
1065
1066                 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1067                     local->next_scan_state == SCAN_DECISION)
1068                         local->next_scan_state = SCAN_SEND_PROBE;
1069
1070                 switch (local->next_scan_state) {
1071                 case SCAN_DECISION:
1072                         /* if no more bands/channels left, complete scan */
1073                         if (local->scan_channel_idx >= scan_req->n_channels) {
1074                                 aborted = false;
1075                                 goto out_complete;
1076                         }
1077                         ieee80211_scan_state_decision(local, &next_delay);
1078                         break;
1079                 case SCAN_SET_CHANNEL:
1080                         ieee80211_scan_state_set_channel(local, &next_delay);
1081                         break;
1082                 case SCAN_SEND_PROBE:
1083                         ieee80211_scan_state_send_probe(local, &next_delay);
1084                         break;
1085                 case SCAN_SUSPEND:
1086                         ieee80211_scan_state_suspend(local, &next_delay);
1087                         break;
1088                 case SCAN_RESUME:
1089                         ieee80211_scan_state_resume(local, &next_delay);
1090                         break;
1091                 case SCAN_ABORT:
1092                         aborted = true;
1093                         goto out_complete;
1094                 }
1095         } while (next_delay == 0);
1096
1097         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1098                                  next_delay);
1099         return;
1100
1101 out_complete:
1102         __ieee80211_scan_completed(&local->hw, aborted);
1103 }
1104
1105 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1106                            struct cfg80211_scan_request *req)
1107 {
1108         lockdep_assert_wiphy(sdata->local->hw.wiphy);
1109
1110         return __ieee80211_start_scan(sdata, req);
1111 }
1112
1113 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1114                                 const u8 *ssid, u8 ssid_len,
1115                                 struct ieee80211_channel **channels,
1116                                 unsigned int n_channels)
1117 {
1118         struct ieee80211_local *local = sdata->local;
1119         int ret = -EBUSY, i, n_ch = 0;
1120         enum nl80211_band band;
1121
1122         lockdep_assert_wiphy(local->hw.wiphy);
1123
1124         /* busy scanning */
1125         if (local->scan_req)
1126                 goto unlock;
1127
1128         /* fill internal scan request */
1129         if (!channels) {
1130                 int max_n;
1131
1132                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1133                         if (!local->hw.wiphy->bands[band] ||
1134                             band == NL80211_BAND_6GHZ)
1135                                 continue;
1136
1137                         max_n = local->hw.wiphy->bands[band]->n_channels;
1138                         for (i = 0; i < max_n; i++) {
1139                                 struct ieee80211_channel *tmp_ch =
1140                                     &local->hw.wiphy->bands[band]->channels[i];
1141
1142                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1143                                                      IEEE80211_CHAN_DISABLED))
1144                                         continue;
1145
1146                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1147                                 n_ch++;
1148                         }
1149                 }
1150
1151                 if (WARN_ON_ONCE(n_ch == 0))
1152                         goto unlock;
1153
1154                 local->int_scan_req->n_channels = n_ch;
1155         } else {
1156                 for (i = 0; i < n_channels; i++) {
1157                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1158                                                   IEEE80211_CHAN_DISABLED))
1159                                 continue;
1160
1161                         local->int_scan_req->channels[n_ch] = channels[i];
1162                         n_ch++;
1163                 }
1164
1165                 if (WARN_ON_ONCE(n_ch == 0))
1166                         goto unlock;
1167
1168                 local->int_scan_req->n_channels = n_ch;
1169         }
1170
1171         local->int_scan_req->ssids = &local->scan_ssid;
1172         local->int_scan_req->n_ssids = 1;
1173         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1174         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1175
1176         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1177  unlock:
1178         return ret;
1179 }
1180
1181 void ieee80211_scan_cancel(struct ieee80211_local *local)
1182 {
1183         /* ensure a new scan cannot be queued */
1184         lockdep_assert_wiphy(local->hw.wiphy);
1185
1186         /*
1187          * We are canceling software scan, or deferred scan that was not
1188          * yet really started (see __ieee80211_start_scan ).
1189          *
1190          * Regarding hardware scan:
1191          * - we can not call  __ieee80211_scan_completed() as when
1192          *   SCAN_HW_SCANNING bit is set this function change
1193          *   local->hw_scan_req to operate on 5G band, what race with
1194          *   driver which can use local->hw_scan_req
1195          *
1196          * - we can not cancel scan_work since driver can schedule it
1197          *   by ieee80211_scan_completed(..., true) to finish scan
1198          *
1199          * Hence we only call the cancel_hw_scan() callback, but the low-level
1200          * driver is still responsible for calling ieee80211_scan_completed()
1201          * after the scan was completed/aborted.
1202          */
1203
1204         if (!local->scan_req)
1205                 return;
1206
1207         /*
1208          * We have a scan running and the driver already reported completion,
1209          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1210          * cancelled.
1211          */
1212         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1213             test_bit(SCAN_COMPLETED, &local->scanning)) {
1214                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1215                 return;
1216         }
1217
1218         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1219                 /*
1220                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1221                  * scan on another band.
1222                  */
1223                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1224                 if (local->ops->cancel_hw_scan)
1225                         drv_cancel_hw_scan(local,
1226                                 rcu_dereference_protected(local->scan_sdata,
1227                                                 lockdep_is_held(&local->hw.wiphy->mtx)));
1228                 return;
1229         }
1230
1231         wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1232         /* and clean up */
1233         memset(&local->scan_info, 0, sizeof(local->scan_info));
1234         __ieee80211_scan_completed(&local->hw, true);
1235 }
1236
1237 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1238                                         struct cfg80211_sched_scan_request *req)
1239 {
1240         struct ieee80211_local *local = sdata->local;
1241         struct ieee80211_scan_ies sched_scan_ies = {};
1242         struct cfg80211_chan_def chandef;
1243         int ret, i, iebufsz, num_bands = 0;
1244         u32 rate_masks[NUM_NL80211_BANDS] = {};
1245         u8 bands_used = 0;
1246         u8 *ie;
1247         u32 flags = 0;
1248
1249         lockdep_assert_wiphy(local->hw.wiphy);
1250
1251         iebufsz = local->scan_ies_len + req->ie_len;
1252
1253         if (!local->ops->sched_scan_start)
1254                 return -ENOTSUPP;
1255
1256         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1257                 if (local->hw.wiphy->bands[i]) {
1258                         bands_used |= BIT(i);
1259                         rate_masks[i] = (u32) -1;
1260                         num_bands++;
1261                 }
1262         }
1263
1264         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1265                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1266
1267         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1268         if (!ie) {
1269                 ret = -ENOMEM;
1270                 goto out;
1271         }
1272
1273         ieee80211_prepare_scan_chandef(&chandef);
1274
1275         ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1276                                  &sched_scan_ies, req->ie,
1277                                  req->ie_len, bands_used, rate_masks, &chandef,
1278                                  flags);
1279
1280         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1281         if (ret == 0) {
1282                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1283                 rcu_assign_pointer(local->sched_scan_req, req);
1284         }
1285
1286         kfree(ie);
1287
1288 out:
1289         if (ret) {
1290                 /* Clean in case of failure after HW restart or upon resume. */
1291                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1292                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1293         }
1294
1295         return ret;
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
1303         lockdep_assert_wiphy(local->hw.wiphy);
1304
1305         if (rcu_access_pointer(local->sched_scan_sdata))
1306                 return -EBUSY;
1307
1308         return __ieee80211_request_sched_scan_start(sdata, req);
1309 }
1310
1311 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1312 {
1313         struct ieee80211_sub_if_data *sched_scan_sdata;
1314         int ret = -ENOENT;
1315
1316         lockdep_assert_wiphy(local->hw.wiphy);
1317
1318         if (!local->ops->sched_scan_stop)
1319                 return -ENOTSUPP;
1320
1321         /* We don't want to restart sched scan anymore. */
1322         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1323
1324         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1325                                                 lockdep_is_held(&local->hw.wiphy->mtx));
1326         if (sched_scan_sdata) {
1327                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1328                 if (!ret)
1329                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1330         }
1331
1332         return ret;
1333 }
1334
1335 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1336 {
1337         struct ieee80211_local *local = hw_to_local(hw);
1338
1339         trace_api_sched_scan_results(local);
1340
1341         cfg80211_sched_scan_results(hw->wiphy, 0);
1342 }
1343 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1344
1345 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1346 {
1347         lockdep_assert_wiphy(local->hw.wiphy);
1348
1349         if (!rcu_access_pointer(local->sched_scan_sdata))
1350                 return;
1351
1352         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1353
1354         /* If sched scan was aborted by the driver. */
1355         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1356
1357         cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1358 }
1359
1360 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1361                                        struct wiphy_work *work)
1362 {
1363         struct ieee80211_local *local =
1364                 container_of(work, struct ieee80211_local,
1365                              sched_scan_stopped_work);
1366
1367         ieee80211_sched_scan_end(local);
1368 }
1369
1370 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1371 {
1372         struct ieee80211_local *local = hw_to_local(hw);
1373
1374         trace_api_sched_scan_stopped(local);
1375
1376         /*
1377          * this shouldn't really happen, so for simplicity
1378          * simply ignore it, and let mac80211 reconfigure
1379          * the sched scan later on.
1380          */
1381         if (local->in_reconfig)
1382                 return;
1383
1384         wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1385 }
1386 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);