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.cfg.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, cbss);
 213         if (!elems)
 214                 return NULL;
 215
 216         /* In case the signal is invalid update the status */
 217         signal_valid = channel == cbss->channel;
 218         if (!signal_valid)
 219                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 220
 221         bss = (void *)cbss->priv;
 222         ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
 223         kfree(elems);
 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                 elems = ieee802_11_parse_elems(elements, len - baselen, false,
 229                                                non_tx_cbss);
 230                 if (!elems)
 231                         continue;
 232
 233                 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
 234                                                 rx_status, beacon);
 235                 kfree(elems);
 236         }
 237
 238         return bss;
 239 }
 240
 241 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 242                                         u32 scan_flags, const u8 *da)
 243 {
 244         if (!sdata)
 245                 return false;
 246         /* accept broadcast for OCE */
 247         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 248             is_broadcast_ether_addr(da))
 249                 return true;
 250         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 251                 return true;
 252         return ether_addr_equal(da, sdata->vif.addr);
 253 }
 254
 255 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 256 {
 257         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 258         struct ieee80211_sub_if_data *sdata1, *sdata2;
 259         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 260         struct ieee80211_bss *bss;
 261         struct ieee80211_channel *channel;
 262         size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 263                                       u.probe_resp.variable);
 264
 265         if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 266             !ieee80211_is_beacon(mgmt->frame_control) &&
 267             !ieee80211_is_s1g_beacon(mgmt->frame_control))
 268                 return;
 269
 270         if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 271                 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 272                         min_hdr_len = offsetof(struct ieee80211_ext,
 273                                                u.s1g_short_beacon.variable);
 274                 else
 275                         min_hdr_len = offsetof(struct ieee80211_ext,
 276                                                u.s1g_beacon);
 277         }
 278
 279         if (skb->len < min_hdr_len)
 280                 return;
 281
 282         sdata1 = rcu_dereference(local->scan_sdata);
 283         sdata2 = rcu_dereference(local->sched_scan_sdata);
 284
 285         if (likely(!sdata1 && !sdata2))
 286                 return;
 287
 288         if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
 289                 /*
 290                  * we were passive scanning because of radar/no-IR, but
 291                  * the beacon/proberesp rx gives us an opportunity to upgrade
 292                  * to active scan
 293                  */
 294                  set_bit(SCAN_BEACON_DONE, &local->scanning);
 295                  ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 296         }
 297
 298         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 299                 struct cfg80211_scan_request *scan_req;
 300                 struct cfg80211_sched_scan_request *sched_scan_req;
 301                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 302
 303                 scan_req = rcu_dereference(local->scan_req);
 304                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 305
 306                 if (scan_req)
 307                         scan_req_flags = scan_req->flags;
 308
 309                 if (sched_scan_req)
 310                         sched_scan_req_flags = sched_scan_req->flags;
 311
 312                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 313                  * unless scanning with randomised address
 314                  */
 315                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 316                                                  mgmt->da) &&
 317                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 318                                                  mgmt->da))
 319                         return;
 320         }
 321
 322         channel = ieee80211_get_channel_khz(local->hw.wiphy,
 323                                         ieee80211_rx_status_to_khz(rx_status));
 324
 325         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 326                 return;
 327
 328         bss = ieee80211_bss_info_update(local, rx_status,
 329                                         mgmt, skb->len,
 330                                         channel);
 331         if (bss)
 332                 ieee80211_rx_bss_put(local, bss);
 333 }
 334
 335 static void
 336 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 337                                enum nl80211_bss_scan_width scan_width)
 338 {
 339         memset(chandef, 0, sizeof(*chandef));
 340         switch (scan_width) {
 341         case NL80211_BSS_CHAN_WIDTH_5:
 342                 chandef->width = NL80211_CHAN_WIDTH_5;
 343                 break;
 344         case NL80211_BSS_CHAN_WIDTH_10:
 345                 chandef->width = NL80211_CHAN_WIDTH_10;
 346                 break;
 347         default:
 348                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 349                 break;
 350         }
 351 }
 352
 353 /* return false if no more work */
 354 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 355 {
 356         struct ieee80211_local *local = sdata->local;
 357         struct cfg80211_scan_request *req;
 358         struct cfg80211_chan_def chandef;
 359         u8 bands_used = 0;
 360         int i, ielen, n_chans;
 361         u32 flags = 0;
 362
 363         req = rcu_dereference_protected(local->scan_req,
 364                                         lockdep_is_held(&local->mtx));
 365
 366         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 367                 return false;
 368
 369         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 370                 for (i = 0; i < req->n_channels; i++) {
 371                         local->hw_scan_req->req.channels[i] = req->channels[i];
 372                         bands_used |= BIT(req->channels[i]->band);
 373                 }
 374
 375                 n_chans = req->n_channels;
 376         } else {
 377                 do {
 378                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 379                                 return false;
 380
 381                         n_chans = 0;
 382
 383                         for (i = 0; i < req->n_channels; i++) {
 384                                 if (req->channels[i]->band !=
 385                                     local->hw_scan_band)
 386                                         continue;
 387                                 local->hw_scan_req->req.channels[n_chans] =
 388                                                         req->channels[i];
 389                                 n_chans++;
 390                                 bands_used |= BIT(req->channels[i]->band);
 391                         }
 392
 393                         local->hw_scan_band++;
 394                 } while (!n_chans);
 395         }
 396
 397         local->hw_scan_req->req.n_channels = n_chans;
 398         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 399
 400         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 401                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 402
 403         ielen = ieee80211_build_preq_ies(sdata,
 404                                          (u8 *)local->hw_scan_req->req.ie,
 405                                          local->hw_scan_ies_bufsize,
 406                                          &local->hw_scan_req->ies,
 407                                          req->ie, req->ie_len,
 408                                          bands_used, req->rates, &chandef,
 409                                          flags);
 410         local->hw_scan_req->req.ie_len = ielen;
 411         local->hw_scan_req->req.no_cck = req->no_cck;
 412         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 413         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 414                         req->mac_addr_mask);
 415         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 416
 417         return true;
 418 }
 419
 420 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 421 {
 422         struct ieee80211_local *local = hw_to_local(hw);
 423         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 424         bool was_scanning = local->scanning;
 425         struct cfg80211_scan_request *scan_req;
 426         struct ieee80211_sub_if_data *scan_sdata;
 427         struct ieee80211_sub_if_data *sdata;
 428
 429         lockdep_assert_held(&local->mtx);
 430
 431         /*
 432          * It's ok to abort a not-yet-running scan (that
 433          * we have one at all will be verified by checking
 434          * local->scan_req next), but not to complete it
 435          * successfully.
 436          */
 437         if (WARN_ON(!local->scanning && !aborted))
 438                 aborted = true;
 439
 440         if (WARN_ON(!local->scan_req))
 441                 return;
 442
 443         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 444                                                lockdep_is_held(&local->mtx));
 445
 446         if (hw_scan && !aborted &&
 447             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 448             ieee80211_prep_hw_scan(scan_sdata)) {
 449                 int rc;
 450
 451                 rc = drv_hw_scan(local,
 452                         rcu_dereference_protected(local->scan_sdata,
 453                                                   lockdep_is_held(&local->mtx)),
 454                         local->hw_scan_req);
 455
 456                 if (rc == 0)
 457                         return;
 458
 459                 /* HW scan failed and is going to be reported as aborted,
 460                  * so clear old scan info.
 461                  */
 462                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 463                 aborted = true;
 464         }
 465
 466         kfree(local->hw_scan_req);
 467         local->hw_scan_req = NULL;
 468
 469         scan_req = rcu_dereference_protected(local->scan_req,
 470                                              lockdep_is_held(&local->mtx));
 471
 472         if (scan_req != local->int_scan_req) {
 473                 local->scan_info.aborted = aborted;
 474                 cfg80211_scan_done(scan_req, &local->scan_info);
 475         }
 476         RCU_INIT_POINTER(local->scan_req, NULL);
 477         RCU_INIT_POINTER(local->scan_sdata, NULL);
 478
 479         local->scanning = 0;
 480         local->scan_chandef.chan = NULL;
 481
 482         /* Set power back to normal operating levels. */
 483         ieee80211_hw_config(local, 0);
 484
 485         if (!hw_scan) {
 486                 ieee80211_configure_filter(local);
 487                 drv_sw_scan_complete(local, scan_sdata);
 488                 ieee80211_offchannel_return(local);
 489         }
 490
 491         ieee80211_recalc_idle(local);
 492
 493         ieee80211_mlme_notify_scan_completed(local);
 494         ieee80211_ibss_notify_scan_completed(local);
 495
 496         /* Requeue all the work that might have been ignored while
 497          * the scan was in progress; if there was none this will
 498          * just be a no-op for the particular interface.
 499          */
 500         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 501                 if (ieee80211_sdata_running(sdata))
 502                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 503         }
 504
 505         if (was_scanning)
 506                 ieee80211_start_next_roc(local);
 507 }
 508
 509 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 510                               struct cfg80211_scan_info *info)
 511 {
 512         struct ieee80211_local *local = hw_to_local(hw);
 513
 514         trace_api_scan_completed(local, info->aborted);
 515
 516         set_bit(SCAN_COMPLETED, &local->scanning);
 517         if (info->aborted)
 518                 set_bit(SCAN_ABORTED, &local->scanning);
 519
 520         memcpy(&local->scan_info, info, sizeof(*info));
 521
 522         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 523 }
 524 EXPORT_SYMBOL(ieee80211_scan_completed);
 525
 526 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 527                                    struct ieee80211_sub_if_data *sdata)
 528 {
 529         /* Software scan is not supported in multi-channel cases */
 530         if (local->use_chanctx)
 531                 return -EOPNOTSUPP;
 532
 533         /*
 534          * Hardware/driver doesn't support hw_scan, so use software
 535          * scanning instead. First send a nullfunc frame with power save
 536          * bit on so that AP will buffer the frames for us while we are not
 537          * listening, then send probe requests to each channel and wait for
 538          * the responses. After all channels are scanned, tune back to the
 539          * original channel and send a nullfunc frame with power save bit
 540          * off to trigger the AP to send us all the buffered frames.
 541          *
 542          * Note that while local->sw_scanning is true everything else but
 543          * nullfunc frames and probe requests will be dropped in
 544          * ieee80211_tx_h_check_assoc().
 545          */
 546         drv_sw_scan_start(local, sdata, local->scan_addr);
 547
 548         local->leave_oper_channel_time = jiffies;
 549         local->next_scan_state = SCAN_DECISION;
 550         local->scan_channel_idx = 0;
 551
 552         ieee80211_offchannel_stop_vifs(local);
 553
 554         /* ensure nullfunc is transmitted before leaving operating channel */
 555         ieee80211_flush_queues(local, NULL, false);
 556
 557         ieee80211_configure_filter(local);
 558
 559         /* We need to set power level at maximum rate for scanning. */
 560         ieee80211_hw_config(local, 0);
 561
 562         ieee80211_queue_delayed_work(&local->hw,
 563                                      &local->scan_work, 0);
 564
 565         return 0;
 566 }
 567
 568 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 569 {
 570         struct ieee80211_local *local = sdata->local;
 571         struct ieee80211_sub_if_data *sdata_iter;
 572
 573         if (!ieee80211_is_radar_required(local))
 574                 return true;
 575
 576         if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 577                 return false;
 578
 579         mutex_lock(&local->iflist_mtx);
 580         list_for_each_entry(sdata_iter, &local->interfaces, list) {
 581                 if (sdata_iter->wdev.cac_started) {
 582                         mutex_unlock(&local->iflist_mtx);
 583                         return false;
 584                 }
 585         }
 586         mutex_unlock(&local->iflist_mtx);
 587
 588         return true;
 589 }
 590
 591 static bool ieee80211_can_scan(struct ieee80211_local *local,
 592                                struct ieee80211_sub_if_data *sdata)
 593 {
 594         if (!__ieee80211_can_leave_ch(sdata))
 595                 return false;
 596
 597         if (!list_empty(&local->roc_list))
 598                 return false;
 599
 600         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 601             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 602                 return false;
 603
 604         return true;
 605 }
 606
 607 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 608 {
 609         lockdep_assert_held(&local->mtx);
 610
 611         if (!local->scan_req || local->scanning)
 612                 return;
 613
 614         if (!ieee80211_can_scan(local,
 615                                 rcu_dereference_protected(
 616                                         local->scan_sdata,
 617                                         lockdep_is_held(&local->mtx))))
 618                 return;
 619
 620         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 621                                      round_jiffies_relative(0));
 622 }
 623
 624 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 625                                           const u8 *src, const u8 *dst,
 626                                           const u8 *ssid, size_t ssid_len,
 627                                           const u8 *ie, size_t ie_len,
 628                                           u32 ratemask, u32 flags, u32 tx_flags,
 629                                           struct ieee80211_channel *channel)
 630 {
 631         struct sk_buff *skb;
 632
 633         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 634                                         ssid, ssid_len,
 635                                         ie, ie_len, flags);
 636
 637         if (skb) {
 638                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 639                         struct ieee80211_hdr *hdr = (void *)skb->data;
 640                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 641                         u16 sn = get_random_u32();
 642
 643                         info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 644                         hdr->seq_ctrl =
 645                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 646                 }
 647                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 648                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 649         }
 650 }
 651
 652 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 653                                             unsigned long *next_delay)
 654 {
 655         int i;
 656         struct ieee80211_sub_if_data *sdata;
 657         struct cfg80211_scan_request *scan_req;
 658         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 659         u32 flags = 0, tx_flags;
 660
 661         scan_req = rcu_dereference_protected(local->scan_req,
 662                                              lockdep_is_held(&local->mtx));
 663
 664         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 665         if (scan_req->no_cck)
 666                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 667         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 668                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 669         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 670                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 671
 672         sdata = rcu_dereference_protected(local->scan_sdata,
 673                                           lockdep_is_held(&local->mtx));
 674
 675         for (i = 0; i < scan_req->n_ssids; i++)
 676                 ieee80211_send_scan_probe_req(
 677                         sdata, local->scan_addr, scan_req->bssid,
 678                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 679                         scan_req->ie, scan_req->ie_len,
 680                         scan_req->rates[band], flags,
 681                         tx_flags, local->hw.conf.chandef.chan);
 682
 683         /*
 684          * After sending probe requests, wait for probe responses
 685          * on the channel.
 686          */
 687         *next_delay = IEEE80211_CHANNEL_TIME;
 688         local->next_scan_state = SCAN_DECISION;
 689 }
 690
 691 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 692                                   struct cfg80211_scan_request *req)
 693 {
 694         struct ieee80211_local *local = sdata->local;
 695         bool hw_scan = local->ops->hw_scan;
 696         int rc;
 697
 698         lockdep_assert_held(&local->mtx);
 699
 700         if (local->scan_req)
 701                 return -EBUSY;
 702
 703         if (!__ieee80211_can_leave_ch(sdata))
 704                 return -EBUSY;
 705
 706         if (!ieee80211_can_scan(local, sdata)) {
 707                 /* wait for the work to finish/time out */
 708                 rcu_assign_pointer(local->scan_req, req);
 709                 rcu_assign_pointer(local->scan_sdata, sdata);
 710                 return 0;
 711         }
 712
 713  again:
 714         if (hw_scan) {
 715                 u8 *ies;
 716
 717                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 718
 719                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 720                         int i, n_bands = 0;
 721                         u8 bands_counted = 0;
 722
 723                         for (i = 0; i < req->n_channels; i++) {
 724                                 if (bands_counted & BIT(req->channels[i]->band))
 725                                         continue;
 726                                 bands_counted |= BIT(req->channels[i]->band);
 727                                 n_bands++;
 728                         }
 729
 730                         local->hw_scan_ies_bufsize *= n_bands;
 731                 }
 732
 733                 local->hw_scan_req = kmalloc(
 734                                 sizeof(*local->hw_scan_req) +
 735                                 req->n_channels * sizeof(req->channels[0]) +
 736                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 737                 if (!local->hw_scan_req)
 738                         return -ENOMEM;
 739
 740                 local->hw_scan_req->req.ssids = req->ssids;
 741                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 742                 ies = (u8 *)local->hw_scan_req +
 743                         sizeof(*local->hw_scan_req) +
 744                         req->n_channels * sizeof(req->channels[0]);
 745                 local->hw_scan_req->req.ie = ies;
 746                 local->hw_scan_req->req.flags = req->flags;
 747                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 748                 local->hw_scan_req->req.duration = req->duration;
 749                 local->hw_scan_req->req.duration_mandatory =
 750                         req->duration_mandatory;
 751
 752                 local->hw_scan_band = 0;
 753                 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 754                 local->hw_scan_req->req.scan_6ghz_params =
 755                         req->scan_6ghz_params;
 756                 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 757
 758                 /*
 759                  * After allocating local->hw_scan_req, we must
 760                  * go through until ieee80211_prep_hw_scan(), so
 761                  * anything that might be changed here and leave
 762                  * this function early must not go after this
 763                  * allocation.
 764                  */
 765         }
 766
 767         rcu_assign_pointer(local->scan_req, req);
 768         rcu_assign_pointer(local->scan_sdata, sdata);
 769
 770         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 771                 get_random_mask_addr(local->scan_addr,
 772                                      req->mac_addr,
 773                                      req->mac_addr_mask);
 774         else
 775                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 776
 777         if (hw_scan) {
 778                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 779         } else if ((req->n_channels == 1) &&
 780                    (req->channels[0] == local->_oper_chandef.chan)) {
 781                 /*
 782                  * If we are scanning only on the operating channel
 783                  * then we do not need to stop normal activities
 784                  */
 785                 unsigned long next_delay;
 786
 787                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 788
 789                 ieee80211_recalc_idle(local);
 790
 791                 /* Notify driver scan is starting, keep order of operations
 792                  * same as normal software scan, in case that matters. */
 793                 drv_sw_scan_start(local, sdata, local->scan_addr);
 794
 795                 ieee80211_configure_filter(local); /* accept probe-responses */
 796
 797                 /* We need to ensure power level is at max for scanning. */
 798                 ieee80211_hw_config(local, 0);
 799
 800                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 801                                                 IEEE80211_CHAN_RADAR)) ||
 802                     !req->n_ssids) {
 803                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 804                         if (req->n_ssids)
 805                                 set_bit(SCAN_BEACON_WAIT, &local->scanning);
 806                 } else {
 807                         ieee80211_scan_state_send_probe(local, &next_delay);
 808                         next_delay = IEEE80211_CHANNEL_TIME;
 809                 }
 810
 811                 /* Now, just wait a bit and we are all done! */
 812                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 813                                              next_delay);
 814                 return 0;
 815         } else {
 816                 /* Do normal software scan */
 817                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 818         }
 819
 820         ieee80211_recalc_idle(local);
 821
 822         if (hw_scan) {
 823                 WARN_ON(!ieee80211_prep_hw_scan(sdata));
 824                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 825         } else {
 826                 rc = ieee80211_start_sw_scan(local, sdata);
 827         }
 828
 829         if (rc) {
 830                 kfree(local->hw_scan_req);
 831                 local->hw_scan_req = NULL;
 832                 local->scanning = 0;
 833
 834                 ieee80211_recalc_idle(local);
 835
 836                 local->scan_req = NULL;
 837                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 838         }
 839
 840         if (hw_scan && rc == 1) {
 841                 /*
 842                  * we can't fall back to software for P2P-GO
 843                  * as it must update NoA etc.
 844                  */
 845                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 846                                 NL80211_IFTYPE_P2P_GO)
 847                         return -EOPNOTSUPP;
 848                 hw_scan = false;
 849                 goto again;
 850         }
 851
 852         return rc;
 853 }
 854
 855 static unsigned long
 856 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 857 {
 858         /*
 859          * TODO: channel switching also consumes quite some time,
 860          * add that delay as well to get a better estimation
 861          */
 862         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 863                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 864         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 865 }
 866
 867 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 868                                           unsigned long *next_delay)
 869 {
 870         bool associated = false;
 871         bool tx_empty = true;
 872         bool bad_latency;
 873         struct ieee80211_sub_if_data *sdata;
 874         struct ieee80211_channel *next_chan;
 875         enum mac80211_scan_state next_scan_state;
 876         struct cfg80211_scan_request *scan_req;
 877
 878         /*
 879          * check if at least one STA interface is associated,
 880          * check if at least one STA interface has pending tx frames
 881          * and grab the lowest used beacon interval
 882          */
 883         mutex_lock(&local->iflist_mtx);
 884         list_for_each_entry(sdata, &local->interfaces, list) {
 885                 if (!ieee80211_sdata_running(sdata))
 886                         continue;
 887
 888                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 889                         if (sdata->u.mgd.associated) {
 890                                 associated = true;
 891
 892                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 893                                         tx_empty = false;
 894                                         break;
 895                                 }
 896                         }
 897                 }
 898         }
 899         mutex_unlock(&local->iflist_mtx);
 900
 901         scan_req = rcu_dereference_protected(local->scan_req,
 902                                              lockdep_is_held(&local->mtx));
 903
 904         next_chan = scan_req->channels[local->scan_channel_idx];
 905
 906         /*
 907          * we're currently scanning a different channel, let's
 908          * see if we can scan another channel without interfering
 909          * with the current traffic situation.
 910          *
 911          * Keep good latency, do not stay off-channel more than 125 ms.
 912          */
 913
 914         bad_latency = time_after(jiffies +
 915                                  ieee80211_scan_get_channel_time(next_chan),
 916                                  local->leave_oper_channel_time + HZ / 8);
 917
 918         if (associated && !tx_empty) {
 919                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 920                         next_scan_state = SCAN_ABORT;
 921                 else
 922                         next_scan_state = SCAN_SUSPEND;
 923         } else if (associated && bad_latency) {
 924                 next_scan_state = SCAN_SUSPEND;
 925         } else {
 926                 next_scan_state = SCAN_SET_CHANNEL;
 927         }
 928
 929         local->next_scan_state = next_scan_state;
 930
 931         *next_delay = 0;
 932 }
 933
 934 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 935                                              unsigned long *next_delay)
 936 {
 937         int skip;
 938         struct ieee80211_channel *chan;
 939         enum nl80211_bss_scan_width oper_scan_width;
 940         struct cfg80211_scan_request *scan_req;
 941
 942         scan_req = rcu_dereference_protected(local->scan_req,
 943                                              lockdep_is_held(&local->mtx));
 944
 945         skip = 0;
 946         chan = scan_req->channels[local->scan_channel_idx];
 947
 948         local->scan_chandef.chan = chan;
 949         local->scan_chandef.center_freq1 = chan->center_freq;
 950         local->scan_chandef.freq1_offset = chan->freq_offset;
 951         local->scan_chandef.center_freq2 = 0;
 952
 953         /* For scanning on the S1G band, ignore scan_width (which is constant
 954          * across all channels) for now since channel width is specific to each
 955          * channel. Detect the required channel width here and likely revisit
 956          * later. Maybe scan_width could be used to build the channel scan list?
 957          */
 958         if (chan->band == NL80211_BAND_S1GHZ) {
 959                 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 960                 goto set_channel;
 961         }
 962
 963         switch (scan_req->scan_width) {
 964         case NL80211_BSS_CHAN_WIDTH_5:
 965                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 966                 break;
 967         case NL80211_BSS_CHAN_WIDTH_10:
 968                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 969                 break;
 970         default:
 971         case NL80211_BSS_CHAN_WIDTH_20:
 972                 /* If scanning on oper channel, use whatever channel-type
 973                  * is currently in use.
 974                  */
 975                 oper_scan_width = cfg80211_chandef_to_scan_width(
 976                                         &local->_oper_chandef);
 977                 if (chan == local->_oper_chandef.chan &&
 978                     oper_scan_width == scan_req->scan_width)
 979                         local->scan_chandef = local->_oper_chandef;
 980                 else
 981                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 982                 break;
 983         case NL80211_BSS_CHAN_WIDTH_1:
 984         case NL80211_BSS_CHAN_WIDTH_2:
 985                 /* shouldn't get here, S1G handled above */
 986                 WARN_ON(1);
 987                 break;
 988         }
 989
 990 set_channel:
 991         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 992                 skip = 1;
 993
 994         /* advance state machine to next channel/band */
 995         local->scan_channel_idx++;
 996
 997         if (skip) {
 998                 /* if we skip this channel return to the decision state */
 999                 local->next_scan_state = SCAN_DECISION;
1000                 return;
1001         }
1002
1003         /*
1004          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1005          * (which unfortunately doesn't say _why_ step a) is done,
1006          * but it waits for the probe delay or until a frame is
1007          * received - and the received frame would update the NAV).
1008          * For now, we do not support waiting until a frame is
1009          * received.
1010          *
1011          * In any case, it is not necessary for a passive scan.
1012          */
1013         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1014             !scan_req->n_ssids) {
1015                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1016                 local->next_scan_state = SCAN_DECISION;
1017                 if (scan_req->n_ssids)
1018                         set_bit(SCAN_BEACON_WAIT, &local->scanning);
1019                 return;
1020         }
1021
1022         /* active scan, send probes */
1023         *next_delay = IEEE80211_PROBE_DELAY;
1024         local->next_scan_state = SCAN_SEND_PROBE;
1025 }
1026
1027 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1028                                          unsigned long *next_delay)
1029 {
1030         /* switch back to the operating channel */
1031         local->scan_chandef.chan = NULL;
1032         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1033
1034         /* disable PS */
1035         ieee80211_offchannel_return(local);
1036
1037         *next_delay = HZ / 5;
1038         /* afterwards, resume scan & go to next channel */
1039         local->next_scan_state = SCAN_RESUME;
1040 }
1041
1042 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1043                                         unsigned long *next_delay)
1044 {
1045         ieee80211_offchannel_stop_vifs(local);
1046
1047         if (local->ops->flush) {
1048                 ieee80211_flush_queues(local, NULL, false);
1049                 *next_delay = 0;
1050         } else
1051                 *next_delay = HZ / 10;
1052
1053         /* remember when we left the operating channel */
1054         local->leave_oper_channel_time = jiffies;
1055
1056         /* advance to the next channel to be scanned */
1057         local->next_scan_state = SCAN_SET_CHANNEL;
1058 }
1059
1060 void ieee80211_scan_work(struct work_struct *work)
1061 {
1062         struct ieee80211_local *local =
1063                 container_of(work, struct ieee80211_local, scan_work.work);
1064         struct ieee80211_sub_if_data *sdata;
1065         struct cfg80211_scan_request *scan_req;
1066         unsigned long next_delay = 0;
1067         bool aborted;
1068
1069         mutex_lock(&local->mtx);
1070
1071         if (!ieee80211_can_run_worker(local)) {
1072                 aborted = true;
1073                 goto out_complete;
1074         }
1075
1076         sdata = rcu_dereference_protected(local->scan_sdata,
1077                                           lockdep_is_held(&local->mtx));
1078         scan_req = rcu_dereference_protected(local->scan_req,
1079                                              lockdep_is_held(&local->mtx));
1080
1081         /* When scanning on-channel, the first-callback means completed. */
1082         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1083                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1084                 goto out_complete;
1085         }
1086
1087         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1088                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1089                 goto out_complete;
1090         }
1091
1092         if (!sdata || !scan_req)
1093                 goto out;
1094
1095         if (!local->scanning) {
1096                 int rc;
1097
1098                 RCU_INIT_POINTER(local->scan_req, NULL);
1099                 RCU_INIT_POINTER(local->scan_sdata, NULL);
1100
1101                 rc = __ieee80211_start_scan(sdata, scan_req);
1102                 if (rc) {
1103                         /* need to complete scan in cfg80211 */
1104                         rcu_assign_pointer(local->scan_req, scan_req);
1105                         aborted = true;
1106                         goto out_complete;
1107                 } else
1108                         goto out;
1109         }
1110
1111         clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1112
1113         /*
1114          * as long as no delay is required advance immediately
1115          * without scheduling a new work
1116          */
1117         do {
1118                 if (!ieee80211_sdata_running(sdata)) {
1119                         aborted = true;
1120                         goto out_complete;
1121                 }
1122
1123                 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1124                     local->next_scan_state == SCAN_DECISION)
1125                         local->next_scan_state = SCAN_SEND_PROBE;
1126
1127                 switch (local->next_scan_state) {
1128                 case SCAN_DECISION:
1129                         /* if no more bands/channels left, complete scan */
1130                         if (local->scan_channel_idx >= scan_req->n_channels) {
1131                                 aborted = false;
1132                                 goto out_complete;
1133                         }
1134                         ieee80211_scan_state_decision(local, &next_delay);
1135                         break;
1136                 case SCAN_SET_CHANNEL:
1137                         ieee80211_scan_state_set_channel(local, &next_delay);
1138                         break;
1139                 case SCAN_SEND_PROBE:
1140                         ieee80211_scan_state_send_probe(local, &next_delay);
1141                         break;
1142                 case SCAN_SUSPEND:
1143                         ieee80211_scan_state_suspend(local, &next_delay);
1144                         break;
1145                 case SCAN_RESUME:
1146                         ieee80211_scan_state_resume(local, &next_delay);
1147                         break;
1148                 case SCAN_ABORT:
1149                         aborted = true;
1150                         goto out_complete;
1151                 }
1152         } while (next_delay == 0);
1153
1154         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1155         goto out;
1156
1157 out_complete:
1158         __ieee80211_scan_completed(&local->hw, aborted);
1159 out:
1160         mutex_unlock(&local->mtx);
1161 }
1162
1163 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1164                            struct cfg80211_scan_request *req)
1165 {
1166         int res;
1167
1168         mutex_lock(&sdata->local->mtx);
1169         res = __ieee80211_start_scan(sdata, req);
1170         mutex_unlock(&sdata->local->mtx);
1171
1172         return res;
1173 }
1174
1175 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1176                                 const u8 *ssid, u8 ssid_len,
1177                                 struct ieee80211_channel **channels,
1178                                 unsigned int n_channels,
1179                                 enum nl80211_bss_scan_width scan_width)
1180 {
1181         struct ieee80211_local *local = sdata->local;
1182         int ret = -EBUSY, i, n_ch = 0;
1183         enum nl80211_band band;
1184
1185         mutex_lock(&local->mtx);
1186
1187         /* busy scanning */
1188         if (local->scan_req)
1189                 goto unlock;
1190
1191         /* fill internal scan request */
1192         if (!channels) {
1193                 int max_n;
1194
1195                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1196                         if (!local->hw.wiphy->bands[band] ||
1197                             band == NL80211_BAND_6GHZ)
1198                                 continue;
1199
1200                         max_n = local->hw.wiphy->bands[band]->n_channels;
1201                         for (i = 0; i < max_n; i++) {
1202                                 struct ieee80211_channel *tmp_ch =
1203                                     &local->hw.wiphy->bands[band]->channels[i];
1204
1205                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1206                                                      IEEE80211_CHAN_DISABLED))
1207                                         continue;
1208
1209                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1210                                 n_ch++;
1211                         }
1212                 }
1213
1214                 if (WARN_ON_ONCE(n_ch == 0))
1215                         goto unlock;
1216
1217                 local->int_scan_req->n_channels = n_ch;
1218         } else {
1219                 for (i = 0; i < n_channels; i++) {
1220                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1221                                                   IEEE80211_CHAN_DISABLED))
1222                                 continue;
1223
1224                         local->int_scan_req->channels[n_ch] = channels[i];
1225                         n_ch++;
1226                 }
1227
1228                 if (WARN_ON_ONCE(n_ch == 0))
1229                         goto unlock;
1230
1231                 local->int_scan_req->n_channels = n_ch;
1232         }
1233
1234         local->int_scan_req->ssids = &local->scan_ssid;
1235         local->int_scan_req->n_ssids = 1;
1236         local->int_scan_req->scan_width = scan_width;
1237         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1238         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1239
1240         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1241  unlock:
1242         mutex_unlock(&local->mtx);
1243         return ret;
1244 }
1245
1246 /*
1247  * Only call this function when a scan can't be queued -- under RTNL.
1248  */
1249 void ieee80211_scan_cancel(struct ieee80211_local *local)
1250 {
1251         /*
1252          * We are canceling software scan, or deferred scan that was not
1253          * yet really started (see __ieee80211_start_scan ).
1254          *
1255          * Regarding hardware scan:
1256          * - we can not call  __ieee80211_scan_completed() as when
1257          *   SCAN_HW_SCANNING bit is set this function change
1258          *   local->hw_scan_req to operate on 5G band, what race with
1259          *   driver which can use local->hw_scan_req
1260          *
1261          * - we can not cancel scan_work since driver can schedule it
1262          *   by ieee80211_scan_completed(..., true) to finish scan
1263          *
1264          * Hence we only call the cancel_hw_scan() callback, but the low-level
1265          * driver is still responsible for calling ieee80211_scan_completed()
1266          * after the scan was completed/aborted.
1267          */
1268
1269         mutex_lock(&local->mtx);
1270         if (!local->scan_req)
1271                 goto out;
1272
1273         /*
1274          * We have a scan running and the driver already reported completion,
1275          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1276          * cancelled.
1277          */
1278         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1279             test_bit(SCAN_COMPLETED, &local->scanning)) {
1280                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1281                 goto out;
1282         }
1283
1284         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1285                 /*
1286                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1287                  * scan on another band.
1288                  */
1289                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1290                 if (local->ops->cancel_hw_scan)
1291                         drv_cancel_hw_scan(local,
1292                                 rcu_dereference_protected(local->scan_sdata,
1293                                                 lockdep_is_held(&local->mtx)));
1294                 goto out;
1295         }
1296
1297         /*
1298          * If the work is currently running, it must be blocked on
1299          * the mutex, but we'll set scan_sdata = NULL and it'll
1300          * simply exit once it acquires the mutex.
1301          */
1302         cancel_delayed_work(&local->scan_work);
1303         /* and clean up */
1304         memset(&local->scan_info, 0, sizeof(local->scan_info));
1305         __ieee80211_scan_completed(&local->hw, true);
1306 out:
1307         mutex_unlock(&local->mtx);
1308 }
1309
1310 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1311                                         struct cfg80211_sched_scan_request *req)
1312 {
1313         struct ieee80211_local *local = sdata->local;
1314         struct ieee80211_scan_ies sched_scan_ies = {};
1315         struct cfg80211_chan_def chandef;
1316         int ret, i, iebufsz, num_bands = 0;
1317         u32 rate_masks[NUM_NL80211_BANDS] = {};
1318         u8 bands_used = 0;
1319         u8 *ie;
1320         u32 flags = 0;
1321
1322         iebufsz = local->scan_ies_len + req->ie_len;
1323
1324         lockdep_assert_held(&local->mtx);
1325
1326         if (!local->ops->sched_scan_start)
1327                 return -ENOTSUPP;
1328
1329         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1330                 if (local->hw.wiphy->bands[i]) {
1331                         bands_used |= BIT(i);
1332                         rate_masks[i] = (u32) -1;
1333                         num_bands++;
1334                 }
1335         }
1336
1337         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1338                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1339
1340         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1341         if (!ie) {
1342                 ret = -ENOMEM;
1343                 goto out;
1344         }
1345
1346         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1347
1348         ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1349                                  &sched_scan_ies, req->ie,
1350                                  req->ie_len, bands_used, rate_masks, &chandef,
1351                                  flags);
1352
1353         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1354         if (ret == 0) {
1355                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1356                 rcu_assign_pointer(local->sched_scan_req, req);
1357         }
1358
1359         kfree(ie);
1360
1361 out:
1362         if (ret) {
1363                 /* Clean in case of failure after HW restart or upon resume. */
1364                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1365                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1366         }
1367
1368         return ret;
1369 }
1370
1371 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1372                                        struct cfg80211_sched_scan_request *req)
1373 {
1374         struct ieee80211_local *local = sdata->local;
1375         int ret;
1376
1377         mutex_lock(&local->mtx);
1378
1379         if (rcu_access_pointer(local->sched_scan_sdata)) {
1380                 mutex_unlock(&local->mtx);
1381                 return -EBUSY;
1382         }
1383
1384         ret = __ieee80211_request_sched_scan_start(sdata, req);
1385
1386         mutex_unlock(&local->mtx);
1387         return ret;
1388 }
1389
1390 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1391 {
1392         struct ieee80211_sub_if_data *sched_scan_sdata;
1393         int ret = -ENOENT;
1394
1395         mutex_lock(&local->mtx);
1396
1397         if (!local->ops->sched_scan_stop) {
1398                 ret = -ENOTSUPP;
1399                 goto out;
1400         }
1401
1402         /* We don't want to restart sched scan anymore. */
1403         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1404
1405         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1406                                                 lockdep_is_held(&local->mtx));
1407         if (sched_scan_sdata) {
1408                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1409                 if (!ret)
1410                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1411         }
1412 out:
1413         mutex_unlock(&local->mtx);
1414
1415         return ret;
1416 }
1417
1418 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1419 {
1420         struct ieee80211_local *local = hw_to_local(hw);
1421
1422         trace_api_sched_scan_results(local);
1423
1424         cfg80211_sched_scan_results(hw->wiphy, 0);
1425 }
1426 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1427
1428 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1429 {
1430         mutex_lock(&local->mtx);
1431
1432         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1433                 mutex_unlock(&local->mtx);
1434                 return;
1435         }
1436
1437         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1438
1439         /* If sched scan was aborted by the driver. */
1440         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1441
1442         mutex_unlock(&local->mtx);
1443
1444         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1445 }
1446
1447 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1448 {
1449         struct ieee80211_local *local =
1450                 container_of(work, struct ieee80211_local,
1451                              sched_scan_stopped_work);
1452
1453         ieee80211_sched_scan_end(local);
1454 }
1455
1456 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1457 {
1458         struct ieee80211_local *local = hw_to_local(hw);
1459
1460         trace_api_sched_scan_stopped(local);
1461
1462         /*
1463          * this shouldn't really happen, so for simplicity
1464          * simply ignore it, and let mac80211 reconfigure
1465          * the sched scan later on.
1466          */
1467         if (local->in_reconfig)
1468                 return;
1469
1470         schedule_work(&local->sched_scan_stopped_work);
1471 }
1472 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);