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) 2018-2021 Intel Corporation
  13  */
  14
  15 #include <linux/if_arp.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rtnetlink.h>
  18 #include <net/sch_generic.h>
  19 #include <linux/slab.h>
  20 #include <linux/export.h>
  21 #include <linux/random.h>
  22 #include <net/mac80211.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "mesh.h"
  27
  28 #define IEEE80211_PROBE_DELAY (HZ / 33)
  29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  31
  32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  33                           struct ieee80211_bss *bss)
  34 {
  35         if (!bss)
  36                 return;
  37         cfg80211_put_bss(local->hw.wiphy,
  38                          container_of((void *)bss, struct cfg80211_bss, priv));
  39 }
  40
  41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  42 {
  43         u8 qos_info;
  44
  45         if (elems->wmm_info && elems->wmm_info_len == 7
  46             && elems->wmm_info[5] == 1)
  47                 qos_info = elems->wmm_info[6];
  48         else if (elems->wmm_param && elems->wmm_param_len == 24
  49                  && elems->wmm_param[5] == 1)
  50                 qos_info = elems->wmm_param[6];
  51         else
  52                 /* no valid wmm information or parameter element found */
  53                 return false;
  54
  55         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  56 }
  57
  58 static void
  59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
  60                                 struct ieee80211_bss *bss,
  61                                 struct ieee802_11_elems *elems,
  62                                 struct ieee80211_rx_status *rx_status,
  63                                 bool beacon)
  64 {
  65         int clen, srlen;
  66
  67         if (beacon)
  68                 bss->device_ts_beacon = rx_status->device_timestamp;
  69         else
  70                 bss->device_ts_presp = rx_status->device_timestamp;
  71
  72         if (elems->parse_error) {
  73                 if (beacon)
  74                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
  75                 else
  76                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
  77         } else {
  78                 if (beacon)
  79                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
  80                 else
  81                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
  82         }
  83
  84         /* save the ERP value so that it is available at association time */
  85         if (elems->erp_info && (!elems->parse_error ||
  86                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
  87                 bss->erp_value = elems->erp_info[0];
  88                 bss->has_erp_value = true;
  89                 if (!elems->parse_error)
  90                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
  91         }
  92
  93         /* replace old supported rates if we get new values */
  94         if (!elems->parse_error ||
  95             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
  96                 srlen = 0;
  97                 if (elems->supp_rates) {
  98                         clen = IEEE80211_MAX_SUPP_RATES;
  99                         if (clen > elems->supp_rates_len)
 100                                 clen = elems->supp_rates_len;
 101                         memcpy(bss->supp_rates, elems->supp_rates, clen);
 102                         srlen += clen;
 103                 }
 104                 if (elems->ext_supp_rates) {
 105                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 106                         if (clen > elems->ext_supp_rates_len)
 107                                 clen = elems->ext_supp_rates_len;
 108                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 109                                clen);
 110                         srlen += clen;
 111                 }
 112                 if (srlen) {
 113                         bss->supp_rates_len = srlen;
 114                         if (!elems->parse_error)
 115                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 116                 }
 117         }
 118
 119         if (!elems->parse_error ||
 120             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 121                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
 122                 bss->uapsd_supported = is_uapsd_supported(elems);
 123                 if (!elems->parse_error)
 124                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 125         }
 126
 127         if (beacon) {
 128                 struct ieee80211_supported_band *sband =
 129                         local->hw.wiphy->bands[rx_status->band];
 130                 if (!(rx_status->encoding == RX_ENC_HT) &&
 131                     !(rx_status->encoding == RX_ENC_VHT))
 132                         bss->beacon_rate =
 133                                 &sband->bitrates[rx_status->rate_idx];
 134         }
 135
 136         if (elems->vht_cap_elem)
 137                 bss->vht_cap_info =
 138                         le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
 139         else
 140                 bss->vht_cap_info = 0;
 141 }
 142
 143 struct ieee80211_bss *
 144 ieee80211_bss_info_update(struct ieee80211_local *local,
 145                           struct ieee80211_rx_status *rx_status,
 146                           struct ieee80211_mgmt *mgmt, size_t len,
 147                           struct ieee80211_channel *channel)
 148 {
 149         bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
 150                       ieee80211_is_s1g_beacon(mgmt->frame_control);
 151         struct cfg80211_bss *cbss, *non_tx_cbss;
 152         struct ieee80211_bss *bss, *non_tx_bss;
 153         struct cfg80211_inform_bss bss_meta = {
 154                 .boottime_ns = rx_status->boottime_ns,
 155         };
 156         bool signal_valid;
 157         struct ieee80211_sub_if_data *scan_sdata;
 158         struct ieee802_11_elems *elems;
 159         size_t baselen;
 160         u8 *elements;
 161
 162         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
 163                 bss_meta.signal = 0; /* invalid signal indication */
 164         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
 165                 bss_meta.signal = rx_status->signal * 100;
 166         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
 167                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
 168
 169         bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
 170         if (rx_status->bw == RATE_INFO_BW_5)
 171                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
 172         else if (rx_status->bw == RATE_INFO_BW_10)
 173                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
 174
 175         bss_meta.chan = channel;
 176
 177         rcu_read_lock();
 178         scan_sdata = rcu_dereference(local->scan_sdata);
 179         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
 180             scan_sdata->vif.bss_conf.assoc &&
 181             ieee80211_have_rx_timestamp(rx_status)) {
 182                 bss_meta.parent_tsf =
 183                         ieee80211_calculate_rx_timestamp(local, rx_status,
 184                                                          len + FCS_LEN, 24);
 185                 ether_addr_copy(bss_meta.parent_bssid,
 186                                 scan_sdata->vif.bss_conf.bssid);
 187         }
 188         rcu_read_unlock();
 189
 190         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 191                                               mgmt, len, GFP_ATOMIC);
 192         if (!cbss)
 193                 return NULL;
 194
 195         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 196                 elements = mgmt->u.probe_resp.variable;
 197                 baselen = offsetof(struct ieee80211_mgmt,
 198                                    u.probe_resp.variable);
 199         } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 200                 struct ieee80211_ext *ext = (void *) mgmt;
 201
 202                 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
 203                 elements = ext->u.s1g_beacon.variable;
 204         } else {
 205                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 206                 elements = mgmt->u.beacon.variable;
 207         }
 208
 209         if (baselen > len)
 210                 return NULL;
 211
 212         elems = ieee802_11_parse_elems(elements, len - baselen, false,
 213                                        mgmt->bssid, cbss->bssid);
 214         if (!elems)
 215                 return NULL;
 216
 217         /* In case the signal is invalid update the status */
 218         signal_valid = channel == cbss->channel;
 219         if (!signal_valid)
 220                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 221
 222         bss = (void *)cbss->priv;
 223         ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
 224
 225         list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
 226                 non_tx_bss = (void *)non_tx_cbss->priv;
 227
 228                 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
 229                                                 rx_status, beacon);
 230         }
 231
 232         kfree(elems);
 233
 234         return bss;
 235 }
 236
 237 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 238                                         u32 scan_flags, const u8 *da)
 239 {
 240         if (!sdata)
 241                 return false;
 242         /* accept broadcast for OCE */
 243         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 244             is_broadcast_ether_addr(da))
 245                 return true;
 246         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 247                 return true;
 248         return ether_addr_equal(da, sdata->vif.addr);
 249 }
 250
 251 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 252 {
 253         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 254         struct ieee80211_sub_if_data *sdata1, *sdata2;
 255         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 256         struct ieee80211_bss *bss;
 257         struct ieee80211_channel *channel;
 258         size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 259                                       u.probe_resp.variable);
 260
 261         if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 262             !ieee80211_is_beacon(mgmt->frame_control) &&
 263             !ieee80211_is_s1g_beacon(mgmt->frame_control))
 264                 return;
 265
 266         if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 267                 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 268                         min_hdr_len = offsetof(struct ieee80211_ext,
 269                                                u.s1g_short_beacon.variable);
 270                 else
 271                         min_hdr_len = offsetof(struct ieee80211_ext,
 272                                                u.s1g_beacon);
 273         }
 274
 275         if (skb->len < min_hdr_len)
 276                 return;
 277
 278         sdata1 = rcu_dereference(local->scan_sdata);
 279         sdata2 = rcu_dereference(local->sched_scan_sdata);
 280
 281         if (likely(!sdata1 && !sdata2))
 282                 return;
 283
 284         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 285                 struct cfg80211_scan_request *scan_req;
 286                 struct cfg80211_sched_scan_request *sched_scan_req;
 287                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 288
 289                 scan_req = rcu_dereference(local->scan_req);
 290                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 291
 292                 if (scan_req)
 293                         scan_req_flags = scan_req->flags;
 294
 295                 if (sched_scan_req)
 296                         sched_scan_req_flags = sched_scan_req->flags;
 297
 298                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 299                  * unless scanning with randomised address
 300                  */
 301                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 302                                                  mgmt->da) &&
 303                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 304                                                  mgmt->da))
 305                         return;
 306         }
 307
 308         channel = ieee80211_get_channel_khz(local->hw.wiphy,
 309                                         ieee80211_rx_status_to_khz(rx_status));
 310
 311         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 312                 return;
 313
 314         bss = ieee80211_bss_info_update(local, rx_status,
 315                                         mgmt, skb->len,
 316                                         channel);
 317         if (bss)
 318                 ieee80211_rx_bss_put(local, bss);
 319 }
 320
 321 static void
 322 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 323                                enum nl80211_bss_scan_width scan_width)
 324 {
 325         memset(chandef, 0, sizeof(*chandef));
 326         switch (scan_width) {
 327         case NL80211_BSS_CHAN_WIDTH_5:
 328                 chandef->width = NL80211_CHAN_WIDTH_5;
 329                 break;
 330         case NL80211_BSS_CHAN_WIDTH_10:
 331                 chandef->width = NL80211_CHAN_WIDTH_10;
 332                 break;
 333         default:
 334                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 335                 break;
 336         }
 337 }
 338
 339 /* return false if no more work */
 340 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 341 {
 342         struct ieee80211_local *local = sdata->local;
 343         struct cfg80211_scan_request *req;
 344         struct cfg80211_chan_def chandef;
 345         u8 bands_used = 0;
 346         int i, ielen, n_chans;
 347         u32 flags = 0;
 348
 349         req = rcu_dereference_protected(local->scan_req,
 350                                         lockdep_is_held(&local->mtx));
 351
 352         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 353                 return false;
 354
 355         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 356                 for (i = 0; i < req->n_channels; i++) {
 357                         local->hw_scan_req->req.channels[i] = req->channels[i];
 358                         bands_used |= BIT(req->channels[i]->band);
 359                 }
 360
 361                 n_chans = req->n_channels;
 362         } else {
 363                 do {
 364                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 365                                 return false;
 366
 367                         n_chans = 0;
 368
 369                         for (i = 0; i < req->n_channels; i++) {
 370                                 if (req->channels[i]->band !=
 371                                     local->hw_scan_band)
 372                                         continue;
 373                                 local->hw_scan_req->req.channels[n_chans] =
 374                                                         req->channels[i];
 375                                 n_chans++;
 376                                 bands_used |= BIT(req->channels[i]->band);
 377                         }
 378
 379                         local->hw_scan_band++;
 380                 } while (!n_chans);
 381         }
 382
 383         local->hw_scan_req->req.n_channels = n_chans;
 384         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 385
 386         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 387                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 388
 389         ielen = ieee80211_build_preq_ies(sdata,
 390                                          (u8 *)local->hw_scan_req->req.ie,
 391                                          local->hw_scan_ies_bufsize,
 392                                          &local->hw_scan_req->ies,
 393                                          req->ie, req->ie_len,
 394                                          bands_used, req->rates, &chandef,
 395                                          flags);
 396         local->hw_scan_req->req.ie_len = ielen;
 397         local->hw_scan_req->req.no_cck = req->no_cck;
 398         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 399         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 400                         req->mac_addr_mask);
 401         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 402
 403         return true;
 404 }
 405
 406 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 407 {
 408         struct ieee80211_local *local = hw_to_local(hw);
 409         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 410         bool was_scanning = local->scanning;
 411         struct cfg80211_scan_request *scan_req;
 412         struct ieee80211_sub_if_data *scan_sdata;
 413         struct ieee80211_sub_if_data *sdata;
 414
 415         lockdep_assert_held(&local->mtx);
 416
 417         /*
 418          * It's ok to abort a not-yet-running scan (that
 419          * we have one at all will be verified by checking
 420          * local->scan_req next), but not to complete it
 421          * successfully.
 422          */
 423         if (WARN_ON(!local->scanning && !aborted))
 424                 aborted = true;
 425
 426         if (WARN_ON(!local->scan_req))
 427                 return;
 428
 429         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 430                                                lockdep_is_held(&local->mtx));
 431
 432         if (hw_scan && !aborted &&
 433             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 434             ieee80211_prep_hw_scan(scan_sdata)) {
 435                 int rc;
 436
 437                 rc = drv_hw_scan(local,
 438                         rcu_dereference_protected(local->scan_sdata,
 439                                                   lockdep_is_held(&local->mtx)),
 440                         local->hw_scan_req);
 441
 442                 if (rc == 0)
 443                         return;
 444
 445                 /* HW scan failed and is going to be reported as aborted,
 446                  * so clear old scan info.
 447                  */
 448                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 449                 aborted = true;
 450         }
 451
 452         kfree(local->hw_scan_req);
 453         local->hw_scan_req = NULL;
 454
 455         scan_req = rcu_dereference_protected(local->scan_req,
 456                                              lockdep_is_held(&local->mtx));
 457
 458         if (scan_req != local->int_scan_req) {
 459                 local->scan_info.aborted = aborted;
 460                 cfg80211_scan_done(scan_req, &local->scan_info);
 461         }
 462         RCU_INIT_POINTER(local->scan_req, NULL);
 463         RCU_INIT_POINTER(local->scan_sdata, NULL);
 464
 465         local->scanning = 0;
 466         local->scan_chandef.chan = NULL;
 467
 468         /* Set power back to normal operating levels. */
 469         ieee80211_hw_config(local, 0);
 470
 471         if (!hw_scan) {
 472                 ieee80211_configure_filter(local);
 473                 drv_sw_scan_complete(local, scan_sdata);
 474                 ieee80211_offchannel_return(local);
 475         }
 476
 477         ieee80211_recalc_idle(local);
 478
 479         ieee80211_mlme_notify_scan_completed(local);
 480         ieee80211_ibss_notify_scan_completed(local);
 481
 482         /* Requeue all the work that might have been ignored while
 483          * the scan was in progress; if there was none this will
 484          * just be a no-op for the particular interface.
 485          */
 486         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 487                 if (ieee80211_sdata_running(sdata))
 488                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 489         }
 490
 491         if (was_scanning)
 492                 ieee80211_start_next_roc(local);
 493 }
 494
 495 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 496                               struct cfg80211_scan_info *info)
 497 {
 498         struct ieee80211_local *local = hw_to_local(hw);
 499
 500         trace_api_scan_completed(local, info->aborted);
 501
 502         set_bit(SCAN_COMPLETED, &local->scanning);
 503         if (info->aborted)
 504                 set_bit(SCAN_ABORTED, &local->scanning);
 505
 506         memcpy(&local->scan_info, info, sizeof(*info));
 507
 508         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 509 }
 510 EXPORT_SYMBOL(ieee80211_scan_completed);
 511
 512 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 513                                    struct ieee80211_sub_if_data *sdata)
 514 {
 515         /* Software scan is not supported in multi-channel cases */
 516         if (local->use_chanctx)
 517                 return -EOPNOTSUPP;
 518
 519         /*
 520          * Hardware/driver doesn't support hw_scan, so use software
 521          * scanning instead. First send a nullfunc frame with power save
 522          * bit on so that AP will buffer the frames for us while we are not
 523          * listening, then send probe requests to each channel and wait for
 524          * the responses. After all channels are scanned, tune back to the
 525          * original channel and send a nullfunc frame with power save bit
 526          * off to trigger the AP to send us all the buffered frames.
 527          *
 528          * Note that while local->sw_scanning is true everything else but
 529          * nullfunc frames and probe requests will be dropped in
 530          * ieee80211_tx_h_check_assoc().
 531          */
 532         drv_sw_scan_start(local, sdata, local->scan_addr);
 533
 534         local->leave_oper_channel_time = jiffies;
 535         local->next_scan_state = SCAN_DECISION;
 536         local->scan_channel_idx = 0;
 537
 538         ieee80211_offchannel_stop_vifs(local);
 539
 540         /* ensure nullfunc is transmitted before leaving operating channel */
 541         ieee80211_flush_queues(local, NULL, false);
 542
 543         ieee80211_configure_filter(local);
 544
 545         /* We need to set power level at maximum rate for scanning. */
 546         ieee80211_hw_config(local, 0);
 547
 548         ieee80211_queue_delayed_work(&local->hw,
 549                                      &local->scan_work, 0);
 550
 551         return 0;
 552 }
 553
 554 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 555 {
 556         struct ieee80211_local *local = sdata->local;
 557         struct ieee80211_sub_if_data *sdata_iter;
 558
 559         if (!ieee80211_is_radar_required(local))
 560                 return true;
 561
 562         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 563                 return false;
 564
 565         mutex_lock(&local->iflist_mtx);
 566         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 567                 if (sdata_iter->wdev.cac_started) {
 568                         mutex_unlock(&local->iflist_mtx);
 569                         return false;
 570                 }
 571         }
 572         mutex_unlock(&local->iflist_mtx);
 573
 574         return true;
 575 }
 576
 577 static bool ieee80211_can_scan(struct ieee80211_local *local,
 578                                struct ieee80211_sub_if_data *sdata)
 579 {
 580         if (!__ieee80211_can_leave_ch(sdata))
 581                 return false;
 582
 583         if (!list_empty(&local->roc_list))
 584                 return false;
 585
 586         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 587             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 588                 return false;
 589
 590         return true;
 591 }
 592
 593 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 594 {
 595         lockdep_assert_held(&local->mtx);
 596
 597         if (!local->scan_req || local->scanning)
 598                 return;
 599
 600         if (!ieee80211_can_scan(local,
 601                                 rcu_dereference_protected(
 602                                         local->scan_sdata,
 603                                         lockdep_is_held(&local->mtx))))
 604                 return;
 605
 606         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 607                                      round_jiffies_relative(0));
 608 }
 609
 610 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 611                                           const u8 *src, const u8 *dst,
 612                                           const u8 *ssid, size_t ssid_len,
 613                                           const u8 *ie, size_t ie_len,
 614                                           u32 ratemask, u32 flags, u32 tx_flags,
 615                                           struct ieee80211_channel *channel)
 616 {
 617         struct sk_buff *skb;
 618
 619         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 620                                         ssid, ssid_len,
 621                                         ie, ie_len, flags);
 622
 623         if (skb) {
 624                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 625                         struct ieee80211_hdr *hdr = (void *)skb->data;
 626                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 627                         u16 sn = get_random_u32();
 628
 629                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 630                         hdr->seq_ctrl =
 631                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 632                 }
 633                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 634                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 635         }
 636 }
 637
 638 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 639                                             unsigned long *next_delay)
 640 {
 641         int i;
 642         struct ieee80211_sub_if_data *sdata;
 643         struct cfg80211_scan_request *scan_req;
 644         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 645         u32 flags = 0, tx_flags;
 646
 647         scan_req = rcu_dereference_protected(local->scan_req,
 648                                              lockdep_is_held(&local->mtx));
 649
 650         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 651         if (scan_req->no_cck)
 652                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 653         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 654                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 655         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 656                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 657
 658         sdata = rcu_dereference_protected(local->scan_sdata,
 659                                           lockdep_is_held(&local->mtx));
 660
 661         for (i = 0; i < scan_req->n_ssids; i++)
 662                 ieee80211_send_scan_probe_req(
 663                         sdata, local->scan_addr, scan_req->bssid,
 664                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 665                         scan_req->ie, scan_req->ie_len,
 666                         scan_req->rates[band], flags,
 667                         tx_flags, local->hw.conf.chandef.chan);
 668
 669         /*
 670          * After sending probe requests, wait for probe responses
 671          * on the channel.
 672          */
 673         *next_delay = IEEE80211_CHANNEL_TIME;
 674         local->next_scan_state = SCAN_DECISION;
 675 }
 676
 677 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 678                                   struct cfg80211_scan_request *req)
 679 {
 680         struct ieee80211_local *local = sdata->local;
 681         bool hw_scan = local->ops->hw_scan;
 682         int rc;
 683
 684         lockdep_assert_held(&local->mtx);
 685
 686         if (local->scan_req)
 687                 return -EBUSY;
 688
 689         if (!__ieee80211_can_leave_ch(sdata))
 690                 return -EBUSY;
 691
 692         if (!ieee80211_can_scan(local, sdata)) {
 693                 /* wait for the work to finish/time out */
 694                 rcu_assign_pointer(local->scan_req, req);
 695                 rcu_assign_pointer(local->scan_sdata, sdata);
 696                 return 0;
 697         }
 698
 699  again:
 700         if (hw_scan) {
 701                 u8 *ies;
 702
 703                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 704
 705                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 706                         int i, n_bands = 0;
 707                         u8 bands_counted = 0;
 708
 709                         for (i = 0; i < req->n_channels; i++) {
 710                                 if (bands_counted & BIT(req->channels[i]->band))
 711                                         continue;
 712                                 bands_counted |= BIT(req->channels[i]->band);
 713                                 n_bands++;
 714                         }
 715
 716                         local->hw_scan_ies_bufsize *= n_bands;
 717                 }
 718
 719                 local->hw_scan_req = kmalloc(
 720                                 sizeof(*local->hw_scan_req) +
 721                                 req->n_channels * sizeof(req->channels[0]) +
 722                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 723                 if (!local->hw_scan_req)
 724                         return -ENOMEM;
 725
 726                 local->hw_scan_req->req.ssids = req->ssids;
 727                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 728                 ies = (u8 *)local->hw_scan_req +
 729                         sizeof(*local->hw_scan_req) +
 730                         req->n_channels * sizeof(req->channels[0]);
 731                 local->hw_scan_req->req.ie = ies;
 732                 local->hw_scan_req->req.flags = req->flags;
 733                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 734                 local->hw_scan_req->req.duration = req->duration;
 735                 local->hw_scan_req->req.duration_mandatory =
 736                         req->duration_mandatory;
 737
 738                 local->hw_scan_band = 0;
 739                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 740                 local->hw_scan_req->req.scan_6ghz_params =
 741                         req->scan_6ghz_params;
 742                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 743
 744                 /*
 745                  * After allocating local->hw_scan_req, we must
 746                  * go through until ieee80211_prep_hw_scan(), so
 747                  * anything that might be changed here and leave
 748                  * this function early must not go after this
 749                  * allocation.
 750                  */
 751         }
 752
 753         rcu_assign_pointer(local->scan_req, req);
 754         rcu_assign_pointer(local->scan_sdata, sdata);
 755
 756         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 757                 get_random_mask_addr(local->scan_addr,
 758                                      req->mac_addr,
 759                                      req->mac_addr_mask);
 760         else
 761                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 762
 763         if (hw_scan) {
 764                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 765         } else if ((req->n_channels == 1) &&
 766                    (req->channels[0] == local->_oper_chandef.chan)) {
 767                 /*
 768                  * If we are scanning only on the operating channel
 769                  * then we do not need to stop normal activities
 770                  */
 771                 unsigned long next_delay;
 772
 773                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 774
 775                 ieee80211_recalc_idle(local);
 776
 777                 /* Notify driver scan is starting, keep order of operations
 778                  * same as normal software scan, in case that matters. */
 779                 drv_sw_scan_start(local, sdata, local->scan_addr);
 780
 781                 ieee80211_configure_filter(local); /* accept probe-responses */
 782
 783                 /* We need to ensure power level is at max for scanning. */
 784                 ieee80211_hw_config(local, 0);
 785
 786                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 787                                                 IEEE80211_CHAN_RADAR)) ||
 788                     !req->n_ssids) {
 789                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 790                 } else {
 791                         ieee80211_scan_state_send_probe(local, &next_delay);
 792                         next_delay = IEEE80211_CHANNEL_TIME;
 793                 }
 794
 795                 /* Now, just wait a bit and we are all done! */
 796                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 797                                              next_delay);
 798                 return 0;
 799         } else {
 800                 /* Do normal software scan */
 801                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 802         }
 803
 804         ieee80211_recalc_idle(local);
 805
 806         if (hw_scan) {
 807                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 808                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 809         } else {
 810                 rc = ieee80211_start_sw_scan(local, sdata);
 811         }
 812
 813         if (rc) {
 814                 kfree(local->hw_scan_req);
 815                 local->hw_scan_req = NULL;
 816                 local->scanning = 0;
 817
 818                 ieee80211_recalc_idle(local);
 819
 820                 local->scan_req = NULL;
 821                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 822         }
 823
 824         if (hw_scan && rc == 1) {
 825                 /*
 826                  * we can't fall back to software for P2P-GO
 827                  * as it must update NoA etc.
 828                  */
 829                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 830                                 NL80211_IFTYPE_P2P_GO)
 831                         return -EOPNOTSUPP;
 832                 hw_scan = false;
 833                 goto again;
 834         }
 835
 836         return rc;
 837 }
 838
 839 static unsigned long
 840 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 841 {
 842         /*
 843          * TODO: channel switching also consumes quite some time,
 844          * add that delay as well to get a better estimation
 845          */
 846         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 847                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 848         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 849 }
 850
 851 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 852                                           unsigned long *next_delay)
 853 {
 854         bool associated = false;
 855         bool tx_empty = true;
 856         bool bad_latency;
 857         struct ieee80211_sub_if_data *sdata;
 858         struct ieee80211_channel *next_chan;
 859         enum mac80211_scan_state next_scan_state;
 860         struct cfg80211_scan_request *scan_req;
 861
 862         /*
 863          * check if at least one STA interface is associated,
 864          * check if at least one STA interface has pending tx frames
 865          * and grab the lowest used beacon interval
 866          */
 867         mutex_lock(&local->iflist_mtx);
 868         list_for_each_entry(sdata, &local->interfaces, list) {
 869                 if (!ieee80211_sdata_running(sdata))
 870                         continue;
 871
 872                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 873                         if (sdata->u.mgd.associated) {
 874                                 associated = true;
 875
 876                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 877                                         tx_empty = false;
 878                                         break;
 879                                 }
 880                         }
 881                 }
 882         }
 883         mutex_unlock(&local->iflist_mtx);
 884
 885         scan_req = rcu_dereference_protected(local->scan_req,
 886                                              lockdep_is_held(&local->mtx));
 887
 888         next_chan = scan_req->channels[local->scan_channel_idx];
 889
 890         /*
 891          * we're currently scanning a different channel, let's
 892          * see if we can scan another channel without interfering
 893          * with the current traffic situation.
 894          *
 895          * Keep good latency, do not stay off-channel more than 125 ms.
 896          */
 897
 898         bad_latency = time_after(jiffies +
 899                                  ieee80211_scan_get_channel_time(next_chan),
 900                                  local->leave_oper_channel_time + HZ / 8);
 901
 902         if (associated && !tx_empty) {
 903                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 904                         next_scan_state = SCAN_ABORT;
 905                 else
 906                         next_scan_state = SCAN_SUSPEND;
 907         } else if (associated && bad_latency) {
 908                 next_scan_state = SCAN_SUSPEND;
 909         } else {
 910                 next_scan_state = SCAN_SET_CHANNEL;
 911         }
 912
 913         local->next_scan_state = next_scan_state;
 914
 915         *next_delay = 0;
 916 }
 917
 918 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 919                                              unsigned long *next_delay)
 920 {
 921         int skip;
 922         struct ieee80211_channel *chan;
 923         enum nl80211_bss_scan_width oper_scan_width;
 924         struct cfg80211_scan_request *scan_req;
 925
 926         scan_req = rcu_dereference_protected(local->scan_req,
 927                                              lockdep_is_held(&local->mtx));
 928
 929         skip = 0;
 930         chan = scan_req->channels[local->scan_channel_idx];
 931
 932         local->scan_chandef.chan = chan;
 933         local->scan_chandef.center_freq1 = chan->center_freq;
 934         local->scan_chandef.freq1_offset = chan->freq_offset;
 935         local->scan_chandef.center_freq2 = 0;
 936
 937         /* For scanning on the S1G band, ignore scan_width (which is constant
 938          * across all channels) for now since channel width is specific to each
 939          * channel. Detect the required channel width here and likely revisit
 940          * later. Maybe scan_width could be used to build the channel scan list?
 941          */
 942         if (chan->band == NL80211_BAND_S1GHZ) {
 943                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 944                 goto set_channel;
 945         }
 946
 947         switch (scan_req->scan_width) {
 948         case NL80211_BSS_CHAN_WIDTH_5:
 949                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 950                 break;
 951         case NL80211_BSS_CHAN_WIDTH_10:
 952                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 953                 break;
 954         default:
 955         case NL80211_BSS_CHAN_WIDTH_20:
 956                 /* If scanning on oper channel, use whatever channel-type
 957                  * is currently in use.
 958                  */
 959                 oper_scan_width = cfg80211_chandef_to_scan_width(
 960                                         &local->_oper_chandef);
 961                 if (chan == local->_oper_chandef.chan &&
 962                     oper_scan_width == scan_req->scan_width)
 963                         local->scan_chandef = local->_oper_chandef;
 964                 else
 965                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 966                 break;
 967         case NL80211_BSS_CHAN_WIDTH_1:
 968         case NL80211_BSS_CHAN_WIDTH_2:
 969                 /* shouldn't get here, S1G handled above */
 970                 WARN_ON(1);
 971                 break;
 972         }
 973
 974 set_channel:
 975         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 976                 skip = 1;
 977
 978         /* advance state machine to next channel/band */
 979         local->scan_channel_idx++;
 980
 981         if (skip) {
 982                 /* if we skip this channel return to the decision state */
 983                 local->next_scan_state = SCAN_DECISION;
 984                 return;
 985         }
 986
 987         /*
 988          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 989          * (which unfortunately doesn't say _why_ step a) is done,
 990          * but it waits for the probe delay or until a frame is
 991          * received - and the received frame would update the NAV).
 992          * For now, we do not support waiting until a frame is
 993          * received.
 994          *
 995          * In any case, it is not necessary for a passive scan.
 996          */
 997         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 998             !scan_req->n_ssids) {
 999                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1000                 local->next_scan_state = SCAN_DECISION;
1001                 return;
1002         }
1003
1004         /* active scan, send probes */
1005         *next_delay = IEEE80211_PROBE_DELAY;
1006         local->next_scan_state = SCAN_SEND_PROBE;
1007 }
1008
1009 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1010                                          unsigned long *next_delay)
1011 {
1012         /* switch back to the operating channel */
1013         local->scan_chandef.chan = NULL;
1014         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1015
1016         /* disable PS */
1017         ieee80211_offchannel_return(local);
1018
1019         *next_delay = HZ / 5;
1020         /* afterwards, resume scan & go to next channel */
1021         local->next_scan_state = SCAN_RESUME;
1022 }
1023
1024 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1025                                         unsigned long *next_delay)
1026 {
1027         ieee80211_offchannel_stop_vifs(local);
1028
1029         if (local->ops->flush) {
1030                 ieee80211_flush_queues(local, NULL, false);
1031                 *next_delay = 0;
1032         } else
1033                 *next_delay = HZ / 10;
1034
1035         /* remember when we left the operating channel */
1036         local->leave_oper_channel_time = jiffies;
1037
1038         /* advance to the next channel to be scanned */
1039         local->next_scan_state = SCAN_SET_CHANNEL;
1040 }
1041
1042 void ieee80211_scan_work(struct work_struct *work)
1043 {
1044         struct ieee80211_local *local =
1045                 container_of(work, struct ieee80211_local, scan_work.work);
1046         struct ieee80211_sub_if_data *sdata;
1047         struct cfg80211_scan_request *scan_req;
1048         unsigned long next_delay = 0;
1049         bool aborted;
1050
1051         mutex_lock(&local->mtx);
1052
1053         if (!ieee80211_can_run_worker(local)) {
1054                 aborted = true;
1055                 goto out_complete;
1056         }
1057
1058         sdata = rcu_dereference_protected(local->scan_sdata,
1059                                           lockdep_is_held(&local->mtx));
1060         scan_req = rcu_dereference_protected(local->scan_req,
1061                                              lockdep_is_held(&local->mtx));
1062
1063         /* When scanning on-channel, the first-callback means completed. */
1064         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1065                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1066                 goto out_complete;
1067         }
1068
1069         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1070                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1071                 goto out_complete;
1072         }
1073
1074         if (!sdata || !scan_req)
1075                 goto out;
1076
1077         if (!local->scanning) {
1078                 int rc;
1079
1080                 RCU_INIT_POINTER(local->scan_req, NULL);
1081                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1082
1083                 rc = __ieee80211_start_scan(sdata, scan_req);
1084                 if (rc) {
1085                         /* need to complete scan in cfg80211 */
1086                         rcu_assign_pointer(local->scan_req, scan_req);
1087                         aborted = true;
1088                         goto out_complete;
1089                 } else
1090                         goto out;
1091         }
1092
1093         /*
1094          * as long as no delay is required advance immediately
1095          * without scheduling a new work
1096          */
1097         do {
1098                 if (!ieee80211_sdata_running(sdata)) {
1099                         aborted = true;
1100                         goto out_complete;
1101                 }
1102
1103                 switch (local->next_scan_state) {
1104                 case SCAN_DECISION:
1105                         /* if no more bands/channels left, complete scan */
1106                         if (local->scan_channel_idx >= scan_req->n_channels) {
1107                                 aborted = false;
1108                                 goto out_complete;
1109                         }
1110                         ieee80211_scan_state_decision(local, &next_delay);
1111                         break;
1112                 case SCAN_SET_CHANNEL:
1113                         ieee80211_scan_state_set_channel(local, &next_delay);
1114                         break;
1115                 case SCAN_SEND_PROBE:
1116                         ieee80211_scan_state_send_probe(local, &next_delay);
1117                         break;
1118                 case SCAN_SUSPEND:
1119                         ieee80211_scan_state_suspend(local, &next_delay);
1120                         break;
1121                 case SCAN_RESUME:
1122                         ieee80211_scan_state_resume(local, &next_delay);
1123                         break;
1124                 case SCAN_ABORT:
1125                         aborted = true;
1126                         goto out_complete;
1127                 }
1128         } while (next_delay == 0);
1129
1130         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1131         goto out;
1132
1133 out_complete:
1134         __ieee80211_scan_completed(&local->hw, aborted);
1135 out:
1136         mutex_unlock(&local->mtx);
1137 }
1138
1139 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1140                            struct cfg80211_scan_request *req)
1141 {
1142         int res;
1143
1144         mutex_lock(&sdata->local->mtx);
1145         res = __ieee80211_start_scan(sdata, req);
1146         mutex_unlock(&sdata->local->mtx);
1147
1148         return res;
1149 }
1150
1151 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1152                                 const u8 *ssid, u8 ssid_len,
1153                                 struct ieee80211_channel **channels,
1154                                 unsigned int n_channels,
1155                                 enum nl80211_bss_scan_width scan_width)
1156 {
1157         struct ieee80211_local *local = sdata->local;
1158         int ret = -EBUSY, i, n_ch = 0;
1159         enum nl80211_band band;
1160
1161         mutex_lock(&local->mtx);
1162
1163         /* busy scanning */
1164         if (local->scan_req)
1165                 goto unlock;
1166
1167         /* fill internal scan request */
1168         if (!channels) {
1169                 int max_n;
1170
1171                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1172                         if (!local->hw.wiphy->bands[band] ||
1173                             band == NL80211_BAND_6GHZ)
1174                                 continue;
1175
1176                         max_n = local->hw.wiphy->bands[band]->n_channels;
1177                         for (i = 0; i < max_n; i++) {
1178                                 struct ieee80211_channel *tmp_ch =
1179                                     &local->hw.wiphy->bands[band]->channels[i];
1180
1181                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1182                                                      IEEE80211_CHAN_DISABLED))
1183                                         continue;
1184
1185                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1186                                 n_ch++;
1187                         }
1188                 }
1189
1190                 if (WARN_ON_ONCE(n_ch == 0))
1191                         goto unlock;
1192
1193                 local->int_scan_req->n_channels = n_ch;
1194         } else {
1195                 for (i = 0; i < n_channels; i++) {
1196                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1197                                                   IEEE80211_CHAN_DISABLED))
1198                                 continue;
1199
1200                         local->int_scan_req->channels[n_ch] = channels[i];
1201                         n_ch++;
1202                 }
1203
1204                 if (WARN_ON_ONCE(n_ch == 0))
1205                         goto unlock;
1206
1207                 local->int_scan_req->n_channels = n_ch;
1208         }
1209
1210         local->int_scan_req->ssids = &local->scan_ssid;
1211         local->int_scan_req->n_ssids = 1;
1212         local->int_scan_req->scan_width = scan_width;
1213         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1214         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1215
1216         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1217  unlock:
1218         mutex_unlock(&local->mtx);
1219         return ret;
1220 }
1221
1222 /*
1223  * Only call this function when a scan can't be queued -- under RTNL.
1224  */
1225 void ieee80211_scan_cancel(struct ieee80211_local *local)
1226 {
1227         /*
1228          * We are canceling software scan, or deferred scan that was not
1229          * yet really started (see __ieee80211_start_scan ).
1230          *
1231          * Regarding hardware scan:
1232          * - we can not call  __ieee80211_scan_completed() as when
1233          *   SCAN_HW_SCANNING bit is set this function change
1234          *   local->hw_scan_req to operate on 5G band, what race with
1235          *   driver which can use local->hw_scan_req
1236          *
1237          * - we can not cancel scan_work since driver can schedule it
1238          *   by ieee80211_scan_completed(..., true) to finish scan
1239          *
1240          * Hence we only call the cancel_hw_scan() callback, but the low-level
1241          * driver is still responsible for calling ieee80211_scan_completed()
1242          * after the scan was completed/aborted.
1243          */
1244
1245         mutex_lock(&local->mtx);
1246         if (!local->scan_req)
1247                 goto out;
1248
1249         /*
1250          * We have a scan running and the driver already reported completion,
1251          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1252          * cancelled.
1253          */
1254         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1255             test_bit(SCAN_COMPLETED, &local->scanning)) {
1256                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1257                 goto out;
1258         }
1259
1260         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1261                 /*
1262                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1263                  * scan on another band.
1264                  */
1265                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1266                 if (local->ops->cancel_hw_scan)
1267                         drv_cancel_hw_scan(local,
1268                                 rcu_dereference_protected(local->scan_sdata,
1269                                                 lockdep_is_held(&local->mtx)));
1270                 goto out;
1271         }
1272
1273         /*
1274          * If the work is currently running, it must be blocked on
1275          * the mutex, but we'll set scan_sdata = NULL and it'll
1276          * simply exit once it acquires the mutex.
1277          */
1278         cancel_delayed_work(&local->scan_work);
1279         /* and clean up */
1280         memset(&local->scan_info, 0, sizeof(local->scan_info));
1281         __ieee80211_scan_completed(&local->hw, true);
1282 out:
1283         mutex_unlock(&local->mtx);
1284 }
1285
1286 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1287                                         struct cfg80211_sched_scan_request *req)
1288 {
1289         struct ieee80211_local *local = sdata->local;
1290         struct ieee80211_scan_ies sched_scan_ies = {};
1291         struct cfg80211_chan_def chandef;
1292         int ret, i, iebufsz, num_bands = 0;
1293         u32 rate_masks[NUM_NL80211_BANDS] = {};
1294         u8 bands_used = 0;
1295         u8 *ie;
1296         u32 flags = 0;
1297
1298         iebufsz = local->scan_ies_len + req->ie_len;
1299
1300         lockdep_assert_held(&local->mtx);
1301
1302         if (!local->ops->sched_scan_start)
1303                 return -ENOTSUPP;
1304
1305         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1306                 if (local->hw.wiphy->bands[i]) {
1307                         bands_used |= BIT(i);
1308                         rate_masks[i] = (u32) -1;
1309                         num_bands++;
1310                 }
1311         }
1312
1313         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1314                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1315
1316         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1317         if (!ie) {
1318                 ret = -ENOMEM;
1319                 goto out;
1320         }
1321
1322         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1323
1324         ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1325                                  &sched_scan_ies, req->ie,
1326                                  req->ie_len, bands_used, rate_masks, &chandef,
1327                                  flags);
1328
1329         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1330         if (ret == 0) {
1331                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1332                 rcu_assign_pointer(local->sched_scan_req, req);
1333         }
1334
1335         kfree(ie);
1336
1337 out:
1338         if (ret) {
1339                 /* Clean in case of failure after HW restart or upon resume. */
1340                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1341                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1342         }
1343
1344         return ret;
1345 }
1346
1347 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1348                                        struct cfg80211_sched_scan_request *req)
1349 {
1350         struct ieee80211_local *local = sdata->local;
1351         int ret;
1352
1353         mutex_lock(&local->mtx);
1354
1355         if (rcu_access_pointer(local->sched_scan_sdata)) {
1356                 mutex_unlock(&local->mtx);
1357                 return -EBUSY;
1358         }
1359
1360         ret = __ieee80211_request_sched_scan_start(sdata, req);
1361
1362         mutex_unlock(&local->mtx);
1363         return ret;
1364 }
1365
1366 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1367 {
1368         struct ieee80211_sub_if_data *sched_scan_sdata;
1369         int ret = -ENOENT;
1370
1371         mutex_lock(&local->mtx);
1372
1373         if (!local->ops->sched_scan_stop) {
1374                 ret = -ENOTSUPP;
1375                 goto out;
1376         }
1377
1378         /* We don't want to restart sched scan anymore. */
1379         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1380
1381         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1382                                                 lockdep_is_held(&local->mtx));
1383         if (sched_scan_sdata) {
1384                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1385                 if (!ret)
1386                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1387         }
1388 out:
1389         mutex_unlock(&local->mtx);
1390
1391         return ret;
1392 }
1393
1394 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1395 {
1396         struct ieee80211_local *local = hw_to_local(hw);
1397
1398         trace_api_sched_scan_results(local);
1399
1400         cfg80211_sched_scan_results(hw->wiphy, 0);
1401 }
1402 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1403
1404 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1405 {
1406         mutex_lock(&local->mtx);
1407
1408         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1409                 mutex_unlock(&local->mtx);
1410                 return;
1411         }
1412
1413         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1414
1415         /* If sched scan was aborted by the driver. */
1416         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1417
1418         mutex_unlock(&local->mtx);
1419
1420         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1421 }
1422
1423 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1424 {
1425         struct ieee80211_local *local =
1426                 container_of(work, struct ieee80211_local,
1427                              sched_scan_stopped_work);
1428
1429         ieee80211_sched_scan_end(local);
1430 }
1431
1432 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1433 {
1434         struct ieee80211_local *local = hw_to_local(hw);
1435
1436         trace_api_sched_scan_stopped(local);
1437
1438         /*
1439          * this shouldn't really happen, so for simplicity
1440          * simply ignore it, and let mac80211 reconfigure
1441          * the sched scan later on.
1442          */
1443         if (local->in_reconfig)
1444                 return;
1445
1446         schedule_work(&local->sched_scan_stopped_work);
1447 }
1448 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);