mac80211/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Scanning implementation
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2004, Instant802 Networks, Inc.
   7  * Copyright 2005, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2013-2015  Intel Mobile Communications GmbH
  11  * Copyright 2016-2017  Intel Deutschland GmbH
  12  * Copyright (C) 2018-2024 Intel Corporation
  13  */
  14
  15 #include <linux/if_arp.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rtnetlink.h>
  18 #include <net/sch_generic.h>
  19 #include <linux/slab.h>
  20 #include <linux/export.h>
  21 #include <linux/random.h>
  22 #include <net/mac80211.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "mesh.h"
  27
  28 #define IEEE80211_PROBE_DELAY (HZ / 33)
  29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  31
  32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  33                           struct ieee80211_bss *bss)
  34 {
  35         if (!bss)
  36                 return;
  37         cfg80211_put_bss(local->hw.wiphy,
  38                          container_of((void *)bss, struct cfg80211_bss, priv));
  39 }
  40
  41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  42 {
  43         u8 qos_info;
  44
  45         if (elems->wmm_info && elems->wmm_info_len == 7
  46             && elems->wmm_info[5] == 1)
  47                 qos_info = elems->wmm_info[6];
  48         else if (elems->wmm_param && elems->wmm_param_len == 24
  49                  && elems->wmm_param[5] == 1)
  50                 qos_info = elems->wmm_param[6];
  51         else
  52                 /* no valid wmm information or parameter element found */
  53                 return false;
  54
  55         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  56 }
  57
  58 struct inform_bss_update_data {
  59         struct ieee80211_rx_status *rx_status;
  60         bool beacon;
  61 };
  62
  63 void ieee80211_inform_bss(struct wiphy *wiphy,
  64                           struct cfg80211_bss *cbss,
  65                           const struct cfg80211_bss_ies *ies,
  66                           void *data)
  67 {
  68         struct ieee80211_local *local = wiphy_priv(wiphy);
  69         struct inform_bss_update_data *update_data = data;
  70         struct ieee80211_bss *bss = (void *)cbss->priv;
  71         struct ieee80211_rx_status *rx_status;
  72         struct ieee802_11_elems *elems;
  73         int clen, srlen;
  74
  75         /* This happens while joining an IBSS */
  76         if (!update_data)
  77                 return;
  78
  79         elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
  80         if (!elems)
  81                 return;
  82
  83         rx_status = update_data->rx_status;
  84
  85         if (update_data->beacon)
  86                 bss->device_ts_beacon = rx_status->device_timestamp;
  87         else
  88                 bss->device_ts_presp = rx_status->device_timestamp;
  89
  90         if (elems->parse_error) {
  91                 if (update_data->beacon)
  92                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
  93                 else
  94                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
  95         } else {
  96                 if (update_data->beacon)
  97                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
  98                 else
  99                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
 100         }
 101
 102         /* save the ERP value so that it is available at association time */
 103         if (elems->erp_info && (!elems->parse_error ||
 104                                 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
 105                 bss->erp_value = elems->erp_info[0];
 106                 bss->has_erp_value = true;
 107                 if (!elems->parse_error)
 108                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
 109         }
 110
 111         /* replace old supported rates if we get new values */
 112         if (!elems->parse_error ||
 113             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
 114                 srlen = 0;
 115                 if (elems->supp_rates) {
 116                         clen = IEEE80211_MAX_SUPP_RATES;
 117                         if (clen > elems->supp_rates_len)
 118                                 clen = elems->supp_rates_len;
 119                         memcpy(bss->supp_rates, elems->supp_rates, clen);
 120                         srlen += clen;
 121                 }
 122                 if (elems->ext_supp_rates) {
 123                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 124                         if (clen > elems->ext_supp_rates_len)
 125                                 clen = elems->ext_supp_rates_len;
 126                         memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 127                                clen);
 128                         srlen += clen;
 129                 }
 130                 if (srlen) {
 131                         bss->supp_rates_len = srlen;
 132                         if (!elems->parse_error)
 133                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 134                 }
 135         }
 136
 137         if (!elems->parse_error ||
 138             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 139                 bss->wmm_used = elems->wmm_param || elems->wmm_info;
 140                 bss->uapsd_supported = is_uapsd_supported(elems);
 141                 if (!elems->parse_error)
 142                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 143         }
 144
 145         if (update_data->beacon) {
 146                 struct ieee80211_supported_band *sband =
 147                         local->hw.wiphy->bands[rx_status->band];
 148                 if (!(rx_status->encoding == RX_ENC_HT) &&
 149                     !(rx_status->encoding == RX_ENC_VHT))
 150                         bss->beacon_rate =
 151                                 &sband->bitrates[rx_status->rate_idx];
 152         }
 153
 154         if (elems->vht_cap_elem)
 155                 bss->vht_cap_info =
 156                         le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
 157         else
 158                 bss->vht_cap_info = 0;
 159
 160         kfree(elems);
 161 }
 162
 163 struct ieee80211_bss *
 164 ieee80211_bss_info_update(struct ieee80211_local *local,
 165                           struct ieee80211_rx_status *rx_status,
 166                           struct ieee80211_mgmt *mgmt, size_t len,
 167                           struct ieee80211_channel *channel)
 168 {
 169         bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
 170                       ieee80211_is_s1g_beacon(mgmt->frame_control);
 171         struct cfg80211_bss *cbss;
 172         struct inform_bss_update_data update_data = {
 173                 .rx_status = rx_status,
 174                 .beacon = beacon,
 175         };
 176         struct cfg80211_inform_bss bss_meta = {
 177                 .boottime_ns = rx_status->boottime_ns,
 178                 .drv_data = (void *)&update_data,
 179         };
 180         bool signal_valid;
 181         struct ieee80211_sub_if_data *scan_sdata;
 182
 183         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
 184                 bss_meta.signal = 0; /* invalid signal indication */
 185         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
 186                 bss_meta.signal = rx_status->signal * 100;
 187         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
 188                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
 189
 190         bss_meta.chan = channel;
 191
 192         rcu_read_lock();
 193         scan_sdata = rcu_dereference(local->scan_sdata);
 194         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
 195             scan_sdata->vif.cfg.assoc &&
 196             ieee80211_have_rx_timestamp(rx_status)) {
 197                 struct ieee80211_bss_conf *link_conf = NULL;
 198
 199                 /* for an MLO connection, set the TSF data only in case we have
 200                  * an indication on which of the links the frame was received
 201                  */
 202                 if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
 203                         if (rx_status->link_valid) {
 204                                 s8 link_id = rx_status->link_id;
 205
 206                                 link_conf =
 207                                         rcu_dereference(scan_sdata->vif.link_conf[link_id]);
 208                         }
 209                 } else {
 210                         link_conf = &scan_sdata->vif.bss_conf;
 211                 }
 212
 213                 if (link_conf) {
 214                         bss_meta.parent_tsf =
 215                                 ieee80211_calculate_rx_timestamp(local,
 216                                                                  rx_status,
 217                                                                  len + FCS_LEN,
 218                                                                  24);
 219
 220                         ether_addr_copy(bss_meta.parent_bssid,
 221                                         link_conf->bssid);
 222                 }
 223         }
 224         rcu_read_unlock();
 225
 226         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 227                                               mgmt, len, GFP_ATOMIC);
 228         if (!cbss)
 229                 return NULL;
 230
 231         /* In case the signal is invalid update the status */
 232         signal_valid = channel == cbss->channel;
 233         if (!signal_valid)
 234                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 235
 236         return (void *)cbss->priv;
 237 }
 238
 239 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 240                                         struct ieee80211_channel *channel,
 241                                         u32 scan_flags, const u8 *da)
 242 {
 243         if (!sdata)
 244                 return false;
 245
 246         /* accept broadcast on 6 GHz and for OCE */
 247         if (is_broadcast_ether_addr(da) &&
 248             (channel->band == NL80211_BAND_6GHZ ||
 249              scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
 250                 return true;
 251
 252         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 253                 return true;
 254         return ether_addr_equal(da, sdata->vif.addr);
 255 }
 256
 257 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 258 {
 259         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 260         struct ieee80211_sub_if_data *sdata1, *sdata2;
 261         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 262         struct ieee80211_bss *bss;
 263         struct ieee80211_channel *channel;
 264         size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 265                                       u.probe_resp.variable);
 266
 267         if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 268             !ieee80211_is_beacon(mgmt->frame_control) &&
 269             !ieee80211_is_s1g_beacon(mgmt->frame_control))
 270                 return;
 271
 272         if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 273                 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 274                         min_hdr_len = offsetof(struct ieee80211_ext,
 275                                                u.s1g_short_beacon.variable);
 276                 else
 277                         min_hdr_len = offsetof(struct ieee80211_ext,
 278                                                u.s1g_beacon);
 279         }
 280
 281         if (skb->len < min_hdr_len)
 282                 return;
 283
 284         sdata1 = rcu_dereference(local->scan_sdata);
 285         sdata2 = rcu_dereference(local->sched_scan_sdata);
 286
 287         if (likely(!sdata1 && !sdata2))
 288                 return;
 289
 290         if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
 291                 /*
 292                  * we were passive scanning because of radar/no-IR, but
 293                  * the beacon/proberesp rx gives us an opportunity to upgrade
 294                  * to active scan
 295                  */
 296                 set_bit(SCAN_BEACON_DONE, &local->scanning);
 297                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 298         }
 299
 300         channel = ieee80211_get_channel_khz(local->hw.wiphy,
 301                                             ieee80211_rx_status_to_khz(rx_status));
 302
 303         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 304                 return;
 305
 306         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 307                 struct cfg80211_scan_request *scan_req;
 308                 struct cfg80211_sched_scan_request *sched_scan_req;
 309                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 310
 311                 scan_req = rcu_dereference(local->scan_req);
 312                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 313
 314                 if (scan_req)
 315                         scan_req_flags = scan_req->flags;
 316
 317                 if (sched_scan_req)
 318                         sched_scan_req_flags = sched_scan_req->flags;
 319
 320                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 321                  * unless scanning with randomised address
 322                  */
 323                 if (!ieee80211_scan_accept_presp(sdata1, channel,
 324                                                  scan_req_flags,
 325                                                  mgmt->da) &&
 326                     !ieee80211_scan_accept_presp(sdata2, channel,
 327                                                  sched_scan_req_flags,
 328                                                  mgmt->da))
 329                         return;
 330         }
 331
 332         bss = ieee80211_bss_info_update(local, rx_status,
 333                                         mgmt, skb->len,
 334                                         channel);
 335         if (bss)
 336                 ieee80211_rx_bss_put(local, bss);
 337 }
 338
 339 static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
 340 {
 341         memset(chandef, 0, sizeof(*chandef));
 342
 343         chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 344 }
 345
 346 /* return false if no more work */
 347 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 348 {
 349         struct ieee80211_local *local = sdata->local;
 350         struct cfg80211_scan_request *req;
 351         struct cfg80211_chan_def chandef;
 352         u8 bands_used = 0;
 353         int i, ielen, n_chans;
 354         u32 flags = 0;
 355
 356         req = rcu_dereference_protected(local->scan_req,
 357                                         lockdep_is_held(&local->hw.wiphy->mtx));
 358
 359         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 360                 return false;
 361
 362         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 363                 for (i = 0; i < req->n_channels; i++) {
 364                         local->hw_scan_req->req.channels[i] = req->channels[i];
 365                         bands_used |= BIT(req->channels[i]->band);
 366                 }
 367
 368                 n_chans = req->n_channels;
 369         } else {
 370                 do {
 371                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 372                                 return false;
 373
 374                         n_chans = 0;
 375
 376                         for (i = 0; i < req->n_channels; i++) {
 377                                 if (req->channels[i]->band !=
 378                                     local->hw_scan_band)
 379                                         continue;
 380                                 local->hw_scan_req->req.channels[n_chans] =
 381                                                         req->channels[i];
 382                                 n_chans++;
 383                                 bands_used |= BIT(req->channels[i]->band);
 384                         }
 385
 386                         local->hw_scan_band++;
 387                 } while (!n_chans);
 388         }
 389
 390         local->hw_scan_req->req.n_channels = n_chans;
 391         ieee80211_prepare_scan_chandef(&chandef);
 392
 393         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 394                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 395
 396         ielen = ieee80211_build_preq_ies(sdata,
 397                                          (u8 *)local->hw_scan_req->req.ie,
 398                                          local->hw_scan_ies_bufsize,
 399                                          &local->hw_scan_req->ies,
 400                                          req->ie, req->ie_len,
 401                                          bands_used, req->rates, &chandef,
 402                                          flags);
 403         local->hw_scan_req->req.ie_len = ielen;
 404         local->hw_scan_req->req.no_cck = req->no_cck;
 405         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 406         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 407                         req->mac_addr_mask);
 408         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 409
 410         return true;
 411 }
 412
 413 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 414 {
 415         struct ieee80211_local *local = hw_to_local(hw);
 416         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 417         bool was_scanning = local->scanning;
 418         struct cfg80211_scan_request *scan_req;
 419         struct ieee80211_sub_if_data *scan_sdata;
 420         struct ieee80211_sub_if_data *sdata;
 421
 422         lockdep_assert_wiphy(local->hw.wiphy);
 423
 424         /*
 425          * It's ok to abort a not-yet-running scan (that
 426          * we have one at all will be verified by checking
 427          * local->scan_req next), but not to complete it
 428          * successfully.
 429          */
 430         if (WARN_ON(!local->scanning && !aborted))
 431                 aborted = true;
 432
 433         if (WARN_ON(!local->scan_req))
 434                 return;
 435
 436         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 437                                                lockdep_is_held(&local->hw.wiphy->mtx));
 438
 439         if (hw_scan && !aborted &&
 440             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 441             ieee80211_prep_hw_scan(scan_sdata)) {
 442                 int rc;
 443
 444                 rc = drv_hw_scan(local,
 445                         rcu_dereference_protected(local->scan_sdata,
 446                                                   lockdep_is_held(&local->hw.wiphy->mtx)),
 447                         local->hw_scan_req);
 448
 449                 if (rc == 0)
 450                         return;
 451
 452                 /* HW scan failed and is going to be reported as aborted,
 453                  * so clear old scan info.
 454                  */
 455                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 456                 aborted = true;
 457         }
 458
 459         kfree(local->hw_scan_req);
 460         local->hw_scan_req = NULL;
 461
 462         scan_req = rcu_dereference_protected(local->scan_req,
 463                                              lockdep_is_held(&local->hw.wiphy->mtx));
 464
 465         RCU_INIT_POINTER(local->scan_req, NULL);
 466         RCU_INIT_POINTER(local->scan_sdata, NULL);
 467
 468         local->scanning = 0;
 469         local->scan_chandef.chan = NULL;
 470
 471         synchronize_rcu();
 472
 473         if (scan_req != local->int_scan_req) {
 474                 local->scan_info.aborted = aborted;
 475                 cfg80211_scan_done(scan_req, &local->scan_info);
 476         }
 477
 478         /* Set power back to normal operating levels. */
 479         ieee80211_hw_config(local, 0);
 480
 481         if (!hw_scan && was_scanning) {
 482                 ieee80211_configure_filter(local);
 483                 drv_sw_scan_complete(local, scan_sdata);
 484                 ieee80211_offchannel_return(local);
 485         }
 486
 487         ieee80211_recalc_idle(local);
 488
 489         ieee80211_mlme_notify_scan_completed(local);
 490         ieee80211_ibss_notify_scan_completed(local);
 491
 492         /* Requeue all the work that might have been ignored while
 493          * the scan was in progress; if there was none this will
 494          * just be a no-op for the particular interface.
 495          */
 496         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 497                 if (ieee80211_sdata_running(sdata))
 498                         wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
 499         }
 500
 501         if (was_scanning)
 502                 ieee80211_start_next_roc(local);
 503 }
 504
 505 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 506                               struct cfg80211_scan_info *info)
 507 {
 508         struct ieee80211_local *local = hw_to_local(hw);
 509
 510         trace_api_scan_completed(local, info->aborted);
 511
 512         set_bit(SCAN_COMPLETED, &local->scanning);
 513         if (info->aborted)
 514                 set_bit(SCAN_ABORTED, &local->scanning);
 515
 516         memcpy(&local->scan_info, info, sizeof(*info));
 517
 518         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 519 }
 520 EXPORT_SYMBOL(ieee80211_scan_completed);
 521
 522 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 523                                    struct ieee80211_sub_if_data *sdata)
 524 {
 525         /* Software scan is not supported in multi-channel cases */
 526         if (local->use_chanctx)
 527                 return -EOPNOTSUPP;
 528
 529         /*
 530          * Hardware/driver doesn't support hw_scan, so use software
 531          * scanning instead. First send a nullfunc frame with power save
 532          * bit on so that AP will buffer the frames for us while we are not
 533          * listening, then send probe requests to each channel and wait for
 534          * the responses. After all channels are scanned, tune back to the
 535          * original channel and send a nullfunc frame with power save bit
 536          * off to trigger the AP to send us all the buffered frames.
 537          *
 538          * Note that while local->sw_scanning is true everything else but
 539          * nullfunc frames and probe requests will be dropped in
 540          * ieee80211_tx_h_check_assoc().
 541          */
 542         drv_sw_scan_start(local, sdata, local->scan_addr);
 543
 544         local->leave_oper_channel_time = jiffies;
 545         local->next_scan_state = SCAN_DECISION;
 546         local->scan_channel_idx = 0;
 547
 548         ieee80211_offchannel_stop_vifs(local);
 549
 550         /* ensure nullfunc is transmitted before leaving operating channel */
 551         ieee80211_flush_queues(local, NULL, false);
 552
 553         ieee80211_configure_filter(local);
 554
 555         /* We need to set power level at maximum rate for scanning. */
 556         ieee80211_hw_config(local, 0);
 557
 558         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
 559
 560         return 0;
 561 }
 562
 563 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 564 {
 565         struct ieee80211_local *local = sdata->local;
 566         struct ieee80211_sub_if_data *sdata_iter;
 567
 568         lockdep_assert_wiphy(local->hw.wiphy);
 569
 570         if (!ieee80211_is_radar_required(local))
 571                 return true;
 572
 573         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 574                 return false;
 575
 576         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 577                 if (sdata_iter->wdev.cac_started)
 578                         return false;
 579         }
 580
 581         return true;
 582 }
 583
 584 static bool ieee80211_can_scan(struct ieee80211_local *local,
 585                                struct ieee80211_sub_if_data *sdata)
 586 {
 587         if (!__ieee80211_can_leave_ch(sdata))
 588                 return false;
 589
 590         if (!list_empty(&local->roc_list))
 591                 return false;
 592
 593         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 594             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 595                 return false;
 596
 597         return true;
 598 }
 599
 600 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 601 {
 602         lockdep_assert_wiphy(local->hw.wiphy);
 603
 604         if (!local->scan_req || local->scanning)
 605                 return;
 606
 607         if (!ieee80211_can_scan(local,
 608                                 rcu_dereference_protected(
 609                                         local->scan_sdata,
 610                                         lockdep_is_held(&local->hw.wiphy->mtx))))
 611                 return;
 612
 613         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 614                                  round_jiffies_relative(0));
 615 }
 616
 617 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 618                                           const u8 *src, const u8 *dst,
 619                                           const u8 *ssid, size_t ssid_len,
 620                                           const u8 *ie, size_t ie_len,
 621                                           u32 ratemask, u32 flags, u32 tx_flags,
 622                                           struct ieee80211_channel *channel)
 623 {
 624         struct sk_buff *skb;
 625
 626         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 627                                         ssid, ssid_len,
 628                                         ie, ie_len, flags);
 629
 630         if (skb) {
 631                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 632                         struct ieee80211_hdr *hdr = (void *)skb->data;
 633                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 634                         u16 sn = get_random_u16();
 635
 636                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 637                         hdr->seq_ctrl =
 638                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 639                 }
 640                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 641                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 642         }
 643 }
 644
 645 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 646                                             unsigned long *next_delay)
 647 {
 648         int i;
 649         struct ieee80211_sub_if_data *sdata;
 650         struct cfg80211_scan_request *scan_req;
 651         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 652         u32 flags = 0, tx_flags;
 653
 654         scan_req = rcu_dereference_protected(local->scan_req,
 655                                              lockdep_is_held(&local->hw.wiphy->mtx));
 656
 657         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 658         if (scan_req->no_cck)
 659                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 660         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 661                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 662         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 663                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 664
 665         sdata = rcu_dereference_protected(local->scan_sdata,
 666                                           lockdep_is_held(&local->hw.wiphy->mtx));
 667
 668         for (i = 0; i < scan_req->n_ssids; i++)
 669                 ieee80211_send_scan_probe_req(
 670                         sdata, local->scan_addr, scan_req->bssid,
 671                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 672                         scan_req->ie, scan_req->ie_len,
 673                         scan_req->rates[band], flags,
 674                         tx_flags, local->hw.conf.chandef.chan);
 675
 676         /*
 677          * After sending probe requests, wait for probe responses
 678          * on the channel.
 679          */
 680         *next_delay = IEEE80211_CHANNEL_TIME;
 681         local->next_scan_state = SCAN_DECISION;
 682 }
 683
 684 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 685                                   struct cfg80211_scan_request *req)
 686 {
 687         struct ieee80211_local *local = sdata->local;
 688         bool hw_scan = local->ops->hw_scan;
 689         int rc;
 690
 691         lockdep_assert_wiphy(local->hw.wiphy);
 692
 693         if (local->scan_req)
 694                 return -EBUSY;
 695
 696         /* For an MLO connection, if a link ID was specified, validate that it
 697          * is indeed active. If no link ID was specified, select one of the
 698          * active links.
 699          */
 700         if (ieee80211_vif_is_mld(&sdata->vif)) {
 701                 if (req->tsf_report_link_id >= 0) {
 702                         if (!(sdata->vif.active_links &
 703                               BIT(req->tsf_report_link_id)))
 704                                 return -EINVAL;
 705                 } else {
 706                         req->tsf_report_link_id =
 707                                 __ffs(sdata->vif.active_links);
 708                 }
 709         }
 710
 711         if (!__ieee80211_can_leave_ch(sdata))
 712                 return -EBUSY;
 713
 714         if (!ieee80211_can_scan(local, sdata)) {
 715                 /* wait for the work to finish/time out */
 716                 rcu_assign_pointer(local->scan_req, req);
 717                 rcu_assign_pointer(local->scan_sdata, sdata);
 718                 return 0;
 719         }
 720
 721  again:
 722         if (hw_scan) {
 723                 u8 *ies;
 724
 725                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 726
 727                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 728                         int i, n_bands = 0;
 729                         u8 bands_counted = 0;
 730
 731                         for (i = 0; i < req->n_channels; i++) {
 732                                 if (bands_counted & BIT(req->channels[i]->band))
 733                                         continue;
 734                                 bands_counted |= BIT(req->channels[i]->band);
 735                                 n_bands++;
 736                         }
 737
 738                         local->hw_scan_ies_bufsize *= n_bands;
 739                 }
 740
 741                 local->hw_scan_req = kmalloc(
 742                                 sizeof(*local->hw_scan_req) +
 743                                 req->n_channels * sizeof(req->channels[0]) +
 744                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 745                 if (!local->hw_scan_req)
 746                         return -ENOMEM;
 747
 748                 local->hw_scan_req->req.ssids = req->ssids;
 749                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 750                 ies = (u8 *)local->hw_scan_req +
 751                         sizeof(*local->hw_scan_req) +
 752                         req->n_channels * sizeof(req->channels[0]);
 753                 local->hw_scan_req->req.ie = ies;
 754                 local->hw_scan_req->req.flags = req->flags;
 755                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 756                 local->hw_scan_req->req.duration = req->duration;
 757                 local->hw_scan_req->req.duration_mandatory =
 758                         req->duration_mandatory;
 759                 local->hw_scan_req->req.tsf_report_link_id =
 760                         req->tsf_report_link_id;
 761
 762                 local->hw_scan_band = 0;
 763                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 764                 local->hw_scan_req->req.scan_6ghz_params =
 765                         req->scan_6ghz_params;
 766                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 767
 768                 /*
 769                  * After allocating local->hw_scan_req, we must
 770                  * go through until ieee80211_prep_hw_scan(), so
 771                  * anything that might be changed here and leave
 772                  * this function early must not go after this
 773                  * allocation.
 774                  */
 775         }
 776
 777         rcu_assign_pointer(local->scan_req, req);
 778         rcu_assign_pointer(local->scan_sdata, sdata);
 779
 780         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 781                 get_random_mask_addr(local->scan_addr,
 782                                      req->mac_addr,
 783                                      req->mac_addr_mask);
 784         else
 785                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 786
 787         if (hw_scan) {
 788                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 789         } else if ((req->n_channels == 1) &&
 790                    (req->channels[0] == local->_oper_chandef.chan)) {
 791                 /*
 792                  * If we are scanning only on the operating channel
 793                  * then we do not need to stop normal activities
 794                  */
 795                 unsigned long next_delay;
 796
 797                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 798
 799                 ieee80211_recalc_idle(local);
 800
 801                 /* Notify driver scan is starting, keep order of operations
 802                  * same as normal software scan, in case that matters. */
 803                 drv_sw_scan_start(local, sdata, local->scan_addr);
 804
 805                 ieee80211_configure_filter(local); /* accept probe-responses */
 806
 807                 /* We need to ensure power level is at max for scanning. */
 808                 ieee80211_hw_config(local, 0);
 809
 810                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 811                                                 IEEE80211_CHAN_RADAR)) ||
 812                     !req->n_ssids) {
 813                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 814                         if (req->n_ssids)
 815                                 set_bit(SCAN_BEACON_WAIT, &local->scanning);
 816                 } else {
 817                         ieee80211_scan_state_send_probe(local, &next_delay);
 818                         next_delay = IEEE80211_CHANNEL_TIME;
 819                 }
 820
 821                 /* Now, just wait a bit and we are all done! */
 822                 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
 823                                          next_delay);
 824                 return 0;
 825         } else {
 826                 /* Do normal software scan */
 827                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 828         }
 829
 830         ieee80211_recalc_idle(local);
 831
 832         if (hw_scan) {
 833                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 834                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 835         } else {
 836                 rc = ieee80211_start_sw_scan(local, sdata);
 837         }
 838
 839         if (rc) {
 840                 kfree(local->hw_scan_req);
 841                 local->hw_scan_req = NULL;
 842                 local->scanning = 0;
 843
 844                 ieee80211_recalc_idle(local);
 845
 846                 local->scan_req = NULL;
 847                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 848         }
 849
 850         if (hw_scan && rc == 1) {
 851                 /*
 852                  * we can't fall back to software for P2P-GO
 853                  * as it must update NoA etc.
 854                  */
 855                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 856                                 NL80211_IFTYPE_P2P_GO)
 857                         return -EOPNOTSUPP;
 858                 hw_scan = false;
 859                 goto again;
 860         }
 861
 862         return rc;
 863 }
 864
 865 static unsigned long
 866 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 867 {
 868         /*
 869          * TODO: channel switching also consumes quite some time,
 870          * add that delay as well to get a better estimation
 871          */
 872         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 873                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 874         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 875 }
 876
 877 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 878                                           unsigned long *next_delay)
 879 {
 880         bool associated = false;
 881         bool tx_empty = true;
 882         bool bad_latency;
 883         struct ieee80211_sub_if_data *sdata;
 884         struct ieee80211_channel *next_chan;
 885         enum mac80211_scan_state next_scan_state;
 886         struct cfg80211_scan_request *scan_req;
 887
 888         lockdep_assert_wiphy(local->hw.wiphy);
 889
 890         /*
 891          * check if at least one STA interface is associated,
 892          * check if at least one STA interface has pending tx frames
 893          * and grab the lowest used beacon interval
 894          */
 895         list_for_each_entry(sdata, &local->interfaces, list) {
 896                 if (!ieee80211_sdata_running(sdata))
 897                         continue;
 898
 899                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 900                         if (sdata->u.mgd.associated) {
 901                                 associated = true;
 902
 903                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 904                                         tx_empty = false;
 905                                         break;
 906                                 }
 907                         }
 908                 }
 909         }
 910
 911         scan_req = rcu_dereference_protected(local->scan_req,
 912                                              lockdep_is_held(&local->hw.wiphy->mtx));
 913
 914         next_chan = scan_req->channels[local->scan_channel_idx];
 915
 916         /*
 917          * we're currently scanning a different channel, let's
 918          * see if we can scan another channel without interfering
 919          * with the current traffic situation.
 920          *
 921          * Keep good latency, do not stay off-channel more than 125 ms.
 922          */
 923
 924         bad_latency = time_after(jiffies +
 925                                  ieee80211_scan_get_channel_time(next_chan),
 926                                  local->leave_oper_channel_time + HZ / 8);
 927
 928         if (associated && !tx_empty) {
 929                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 930                         next_scan_state = SCAN_ABORT;
 931                 else
 932                         next_scan_state = SCAN_SUSPEND;
 933         } else if (associated && bad_latency) {
 934                 next_scan_state = SCAN_SUSPEND;
 935         } else {
 936                 next_scan_state = SCAN_SET_CHANNEL;
 937         }
 938
 939         local->next_scan_state = next_scan_state;
 940
 941         *next_delay = 0;
 942 }
 943
 944 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 945                                              unsigned long *next_delay)
 946 {
 947         int skip;
 948         struct ieee80211_channel *chan;
 949         struct cfg80211_scan_request *scan_req;
 950
 951         scan_req = rcu_dereference_protected(local->scan_req,
 952                                              lockdep_is_held(&local->hw.wiphy->mtx));
 953
 954         skip = 0;
 955         chan = scan_req->channels[local->scan_channel_idx];
 956
 957         local->scan_chandef.chan = chan;
 958         local->scan_chandef.center_freq1 = chan->center_freq;
 959         local->scan_chandef.freq1_offset = chan->freq_offset;
 960         local->scan_chandef.center_freq2 = 0;
 961
 962         /* For scanning on the S1G band, detect the channel width according to
 963          * the channel being scanned.
 964          */
 965         if (chan->band == NL80211_BAND_S1GHZ) {
 966                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 967                 goto set_channel;
 968         }
 969
 970         /* If scanning on oper channel, use whatever channel-type
 971          * is currently in use.
 972          */
 973         if (chan == local->_oper_chandef.chan)
 974                 local->scan_chandef = local->_oper_chandef;
 975         else
 976                 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 977
 978 set_channel:
 979         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 980                 skip = 1;
 981
 982         /* advance state machine to next channel/band */
 983         local->scan_channel_idx++;
 984
 985         if (skip) {
 986                 /* if we skip this channel return to the decision state */
 987                 local->next_scan_state = SCAN_DECISION;
 988                 return;
 989         }
 990
 991         /*
 992          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 993          * (which unfortunately doesn't say _why_ step a) is done,
 994          * but it waits for the probe delay or until a frame is
 995          * received - and the received frame would update the NAV).
 996          * For now, we do not support waiting until a frame is
 997          * received.
 998          *
 999          * In any case, it is not necessary for a passive scan.
1000          */
1001         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1002             !scan_req->n_ssids) {
1003                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1004                 local->next_scan_state = SCAN_DECISION;
1005                 if (scan_req->n_ssids)
1006                         set_bit(SCAN_BEACON_WAIT, &local->scanning);
1007                 return;
1008         }
1009
1010         /* active scan, send probes */
1011         *next_delay = IEEE80211_PROBE_DELAY;
1012         local->next_scan_state = SCAN_SEND_PROBE;
1013 }
1014
1015 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1016                                          unsigned long *next_delay)
1017 {
1018         /* switch back to the operating channel */
1019         local->scan_chandef.chan = NULL;
1020         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1021
1022         /* disable PS */
1023         ieee80211_offchannel_return(local);
1024
1025         *next_delay = HZ / 5;
1026         /* afterwards, resume scan & go to next channel */
1027         local->next_scan_state = SCAN_RESUME;
1028 }
1029
1030 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1031                                         unsigned long *next_delay)
1032 {
1033         ieee80211_offchannel_stop_vifs(local);
1034
1035         if (local->ops->flush) {
1036                 ieee80211_flush_queues(local, NULL, false);
1037                 *next_delay = 0;
1038         } else
1039                 *next_delay = HZ / 10;
1040
1041         /* remember when we left the operating channel */
1042         local->leave_oper_channel_time = jiffies;
1043
1044         /* advance to the next channel to be scanned */
1045         local->next_scan_state = SCAN_SET_CHANNEL;
1046 }
1047
1048 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1049 {
1050         struct ieee80211_local *local =
1051                 container_of(work, struct ieee80211_local, scan_work.work);
1052         struct ieee80211_sub_if_data *sdata;
1053         struct cfg80211_scan_request *scan_req;
1054         unsigned long next_delay = 0;
1055         bool aborted;
1056
1057         lockdep_assert_wiphy(local->hw.wiphy);
1058
1059         if (!ieee80211_can_run_worker(local)) {
1060                 aborted = true;
1061                 goto out_complete;
1062         }
1063
1064         sdata = rcu_dereference_protected(local->scan_sdata,
1065                                           lockdep_is_held(&local->hw.wiphy->mtx));
1066         scan_req = rcu_dereference_protected(local->scan_req,
1067                                              lockdep_is_held(&local->hw.wiphy->mtx));
1068
1069         /* When scanning on-channel, the first-callback means completed. */
1070         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1071                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1072                 goto out_complete;
1073         }
1074
1075         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1076                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1077                 goto out_complete;
1078         }
1079
1080         if (!sdata || !scan_req)
1081                 return;
1082
1083         if (!local->scanning) {
1084                 int rc;
1085
1086                 RCU_INIT_POINTER(local->scan_req, NULL);
1087                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1088
1089                 rc = __ieee80211_start_scan(sdata, scan_req);
1090                 if (!rc)
1091                         return;
1092                 /* need to complete scan in cfg80211 */
1093                 rcu_assign_pointer(local->scan_req, scan_req);
1094                 aborted = true;
1095                 goto out_complete;
1096         }
1097
1098         clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1099
1100         /*
1101          * as long as no delay is required advance immediately
1102          * without scheduling a new work
1103          */
1104         do {
1105                 if (!ieee80211_sdata_running(sdata)) {
1106                         aborted = true;
1107                         goto out_complete;
1108                 }
1109
1110                 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1111                     local->next_scan_state == SCAN_DECISION)
1112                         local->next_scan_state = SCAN_SEND_PROBE;
1113
1114                 switch (local->next_scan_state) {
1115                 case SCAN_DECISION:
1116                         /* if no more bands/channels left, complete scan */
1117                         if (local->scan_channel_idx >= scan_req->n_channels) {
1118                                 aborted = false;
1119                                 goto out_complete;
1120                         }
1121                         ieee80211_scan_state_decision(local, &next_delay);
1122                         break;
1123                 case SCAN_SET_CHANNEL:
1124                         ieee80211_scan_state_set_channel(local, &next_delay);
1125                         break;
1126                 case SCAN_SEND_PROBE:
1127                         ieee80211_scan_state_send_probe(local, &next_delay);
1128                         break;
1129                 case SCAN_SUSPEND:
1130                         ieee80211_scan_state_suspend(local, &next_delay);
1131                         break;
1132                 case SCAN_RESUME:
1133                         ieee80211_scan_state_resume(local, &next_delay);
1134                         break;
1135                 case SCAN_ABORT:
1136                         aborted = true;
1137                         goto out_complete;
1138                 }
1139         } while (next_delay == 0);
1140
1141         wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1142                                  next_delay);
1143         return;
1144
1145 out_complete:
1146         __ieee80211_scan_completed(&local->hw, aborted);
1147 }
1148
1149 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1150                            struct cfg80211_scan_request *req)
1151 {
1152         lockdep_assert_wiphy(sdata->local->hw.wiphy);
1153
1154         return __ieee80211_start_scan(sdata, req);
1155 }
1156
1157 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1158                                 const u8 *ssid, u8 ssid_len,
1159                                 struct ieee80211_channel **channels,
1160                                 unsigned int n_channels)
1161 {
1162         struct ieee80211_local *local = sdata->local;
1163         int ret = -EBUSY, i, n_ch = 0;
1164         enum nl80211_band band;
1165
1166         lockdep_assert_wiphy(local->hw.wiphy);
1167
1168         /* busy scanning */
1169         if (local->scan_req)
1170                 goto unlock;
1171
1172         /* fill internal scan request */
1173         if (!channels) {
1174                 int max_n;
1175
1176                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1177                         if (!local->hw.wiphy->bands[band] ||
1178                             band == NL80211_BAND_6GHZ)
1179                                 continue;
1180
1181                         max_n = local->hw.wiphy->bands[band]->n_channels;
1182                         for (i = 0; i < max_n; i++) {
1183                                 struct ieee80211_channel *tmp_ch =
1184                                     &local->hw.wiphy->bands[band]->channels[i];
1185
1186                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1187                                                      IEEE80211_CHAN_DISABLED))
1188                                         continue;
1189
1190                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1191                                 n_ch++;
1192                         }
1193                 }
1194
1195                 if (WARN_ON_ONCE(n_ch == 0))
1196                         goto unlock;
1197
1198                 local->int_scan_req->n_channels = n_ch;
1199         } else {
1200                 for (i = 0; i < n_channels; i++) {
1201                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1202                                                   IEEE80211_CHAN_DISABLED))
1203                                 continue;
1204
1205                         local->int_scan_req->channels[n_ch] = channels[i];
1206                         n_ch++;
1207                 }
1208
1209                 if (WARN_ON_ONCE(n_ch == 0))
1210                         goto unlock;
1211
1212                 local->int_scan_req->n_channels = n_ch;
1213         }
1214
1215         local->int_scan_req->ssids = &local->scan_ssid;
1216         local->int_scan_req->n_ssids = 1;
1217         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1218         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1219
1220         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1221  unlock:
1222         return ret;
1223 }
1224
1225 void ieee80211_scan_cancel(struct ieee80211_local *local)
1226 {
1227         /* ensure a new scan cannot be queued */
1228         lockdep_assert_wiphy(local->hw.wiphy);
1229
1230         /*
1231          * We are canceling software scan, or deferred scan that was not
1232          * yet really started (see __ieee80211_start_scan ).
1233          *
1234          * Regarding hardware scan:
1235          * - we can not call  __ieee80211_scan_completed() as when
1236          *   SCAN_HW_SCANNING bit is set this function change
1237          *   local->hw_scan_req to operate on 5G band, what race with
1238          *   driver which can use local->hw_scan_req
1239          *
1240          * - we can not cancel scan_work since driver can schedule it
1241          *   by ieee80211_scan_completed(..., true) to finish scan
1242          *
1243          * Hence we only call the cancel_hw_scan() callback, but the low-level
1244          * driver is still responsible for calling ieee80211_scan_completed()
1245          * after the scan was completed/aborted.
1246          */
1247
1248         if (!local->scan_req)
1249                 return;
1250
1251         /*
1252          * We have a scan running and the driver already reported completion,
1253          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1254          * cancelled.
1255          */
1256         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1257             test_bit(SCAN_COMPLETED, &local->scanning)) {
1258                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1259                 return;
1260         }
1261
1262         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1263                 /*
1264                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1265                  * scan on another band.
1266                  */
1267                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1268                 if (local->ops->cancel_hw_scan)
1269                         drv_cancel_hw_scan(local,
1270                                 rcu_dereference_protected(local->scan_sdata,
1271                                                 lockdep_is_held(&local->hw.wiphy->mtx)));
1272                 return;
1273         }
1274
1275         wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1276         /* and clean up */
1277         memset(&local->scan_info, 0, sizeof(local->scan_info));
1278         __ieee80211_scan_completed(&local->hw, true);
1279 }
1280
1281 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1282                                         struct cfg80211_sched_scan_request *req)
1283 {
1284         struct ieee80211_local *local = sdata->local;
1285         struct ieee80211_scan_ies sched_scan_ies = {};
1286         struct cfg80211_chan_def chandef;
1287         int ret, i, iebufsz, num_bands = 0;
1288         u32 rate_masks[NUM_NL80211_BANDS] = {};
1289         u8 bands_used = 0;
1290         u8 *ie;
1291         u32 flags = 0;
1292
1293         lockdep_assert_wiphy(local->hw.wiphy);
1294
1295         iebufsz = local->scan_ies_len + req->ie_len;
1296
1297         if (!local->ops->sched_scan_start)
1298                 return -EOPNOTSUPP;
1299
1300         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1301                 if (local->hw.wiphy->bands[i]) {
1302                         bands_used |= BIT(i);
1303                         rate_masks[i] = (u32) -1;
1304                         num_bands++;
1305                 }
1306         }
1307
1308         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1309                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1310
1311         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1312         if (!ie) {
1313                 ret = -ENOMEM;
1314                 goto out;
1315         }
1316
1317         ieee80211_prepare_scan_chandef(&chandef);
1318
1319         ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1320                                  &sched_scan_ies, req->ie,
1321                                  req->ie_len, bands_used, rate_masks, &chandef,
1322                                  flags);
1323
1324         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1325         if (ret == 0) {
1326                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1327                 rcu_assign_pointer(local->sched_scan_req, req);
1328         }
1329
1330         kfree(ie);
1331
1332 out:
1333         if (ret) {
1334                 /* Clean in case of failure after HW restart or upon resume. */
1335                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1336                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1337         }
1338
1339         return ret;
1340 }
1341
1342 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1343                                        struct cfg80211_sched_scan_request *req)
1344 {
1345         struct ieee80211_local *local = sdata->local;
1346
1347         lockdep_assert_wiphy(local->hw.wiphy);
1348
1349         if (rcu_access_pointer(local->sched_scan_sdata))
1350                 return -EBUSY;
1351
1352         return __ieee80211_request_sched_scan_start(sdata, req);
1353 }
1354
1355 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1356 {
1357         struct ieee80211_sub_if_data *sched_scan_sdata;
1358         int ret = -ENOENT;
1359
1360         lockdep_assert_wiphy(local->hw.wiphy);
1361
1362         if (!local->ops->sched_scan_stop)
1363                 return -EOPNOTSUPP;
1364
1365         /* We don't want to restart sched scan anymore. */
1366         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1367
1368         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1369                                                 lockdep_is_held(&local->hw.wiphy->mtx));
1370         if (sched_scan_sdata) {
1371                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1372                 if (!ret)
1373                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1374         }
1375
1376         return ret;
1377 }
1378
1379 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1380 {
1381         struct ieee80211_local *local = hw_to_local(hw);
1382
1383         trace_api_sched_scan_results(local);
1384
1385         cfg80211_sched_scan_results(hw->wiphy, 0);
1386 }
1387 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1388
1389 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1390 {
1391         lockdep_assert_wiphy(local->hw.wiphy);
1392
1393         if (!rcu_access_pointer(local->sched_scan_sdata))
1394                 return;
1395
1396         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1397
1398         /* If sched scan was aborted by the driver. */
1399         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1400
1401         cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1402 }
1403
1404 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1405                                        struct wiphy_work *work)
1406 {
1407         struct ieee80211_local *local =
1408                 container_of(work, struct ieee80211_local,
1409                              sched_scan_stopped_work);
1410
1411         ieee80211_sched_scan_end(local);
1412 }
1413
1414 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1415 {
1416         struct ieee80211_local *local = hw_to_local(hw);
1417
1418         trace_api_sched_scan_stopped(local);
1419
1420         /*
1421          * this shouldn't really happen, so for simplicity
1422          * simply ignore it, and let mac80211 reconfigure
1423          * the sched scan later on.
1424          */
1425         if (local->in_reconfig)
1426                 return;
1427
1428         wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1429 }
1430 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);