net/mac80211/scan.c

   1 /*
   2  * Scanning implementation
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2004, Instant802 Networks, Inc.
   6  * Copyright 2005, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  * Copyright 2013-2015  Intel Mobile Communications GmbH
  10  * Copyright 2016-2017  Intel Deutschland GmbH
  11  * Copyright (C) 2018-2019 Intel Corporation
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License version 2 as
  15  * published by the Free Software Foundation.
  16  */
  17
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/sch_generic.h>
  22 #include <linux/slab.h>
  23 #include <linux/export.h>
  24 #include <linux/random.h>
  25 #include <net/mac80211.h>
  26
  27 #include "ieee80211_i.h"
  28 #include "driver-ops.h"
  29 #include "mesh.h"
  30
  31 #define IEEE80211_PROBE_DELAY (HZ / 33)
  32 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  33 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  34
  35 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  36                           struct ieee80211_bss *bss)
  37 {
  38         if (!bss)
  39                 return;
  40         cfg80211_put_bss(local->hw.wiphy,
  41                          container_of((void *)bss, struct cfg80211_bss, priv));
  42 }
  43
  44 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  45 {
  46         u8 qos_info;
  47
  48         if (elems->wmm_info && elems->wmm_info_len == 7
  49             && elems->wmm_info[5] == 1)
  50                 qos_info = elems->wmm_info[6];
  51         else if (elems->wmm_param && elems->wmm_param_len == 24
  52                  && elems->wmm_param[5] == 1)
  53                 qos_info = elems->wmm_param[6];
  54         else
  55                 /* no valid wmm information or parameter element found */
  56                 return false;
  57
  58         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  59 }
  60
  61 struct ieee80211_bss *
  62 ieee80211_bss_info_update(struct ieee80211_local *local,
  63                           struct ieee80211_rx_status *rx_status,
  64                           struct ieee80211_mgmt *mgmt, size_t len,
  65                           struct ieee80211_channel *channel)
  66 {
  67         bool beacon = ieee80211_is_beacon(mgmt->frame_control);
  68         struct cfg80211_bss *cbss;
  69         struct ieee80211_bss *bss;
  70         int clen, srlen;
  71         struct cfg80211_inform_bss bss_meta = {
  72                 .boottime_ns = rx_status->boottime_ns,
  73         };
  74         bool signal_valid;
  75         struct ieee80211_sub_if_data *scan_sdata;
  76         struct ieee802_11_elems elems;
  77         size_t baselen;
  78         u8 *elements;
  79
  80         if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
  81                 bss_meta.signal = 0; /* invalid signal indication */
  82         else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
  83                 bss_meta.signal = rx_status->signal * 100;
  84         else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
  85                 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
  86
  87         bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
  88         if (rx_status->bw == RATE_INFO_BW_5)
  89                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
  90         else if (rx_status->bw == RATE_INFO_BW_10)
  91                 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
  92
  93         bss_meta.chan = channel;
  94
  95         rcu_read_lock();
  96         scan_sdata = rcu_dereference(local->scan_sdata);
  97         if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
  98             scan_sdata->vif.bss_conf.assoc &&
  99             ieee80211_have_rx_timestamp(rx_status)) {
 100                 bss_meta.parent_tsf =
 101                         ieee80211_calculate_rx_timestamp(local, rx_status,
 102                                                          len + FCS_LEN, 24);
 103                 ether_addr_copy(bss_meta.parent_bssid,
 104                                 scan_sdata->vif.bss_conf.bssid);
 105         }
 106         rcu_read_unlock();
 107
 108         cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 109                                               mgmt, len, GFP_ATOMIC);
 110         if (!cbss)
 111                 return NULL;
 112
 113         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 114                 elements = mgmt->u.probe_resp.variable;
 115                 baselen = offsetof(struct ieee80211_mgmt,
 116                                    u.probe_resp.variable);
 117         } else {
 118                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 119                 elements = mgmt->u.beacon.variable;
 120         }
 121
 122         if (baselen > len)
 123                 return NULL;
 124
 125         ieee802_11_parse_elems(elements, len - baselen, false, &elems,
 126                                mgmt->bssid, cbss->bssid);
 127
 128         /* In case the signal is invalid update the status */
 129         signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
 130                 <= local->hw.wiphy->max_adj_channel_rssi_comp;
 131         if (!signal_valid)
 132                 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 133
 134         bss = (void *)cbss->priv;
 135
 136         if (beacon)
 137                 bss->device_ts_beacon = rx_status->device_timestamp;
 138         else
 139                 bss->device_ts_presp = rx_status->device_timestamp;
 140
 141         if (elems.parse_error) {
 142                 if (beacon)
 143                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
 144                 else
 145                         bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
 146         } else {
 147                 if (beacon)
 148                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
 149                 else
 150                         bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
 151         }
 152
 153         /* save the ERP value so that it is available at association time */
 154         if (elems.erp_info && (!elems.parse_error ||
 155                                !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
 156                 bss->erp_value = elems.erp_info[0];
 157                 bss->has_erp_value = true;
 158                 if (!elems.parse_error)
 159                         bss->valid_data |= IEEE80211_BSS_VALID_ERP;
 160         }
 161
 162         /* replace old supported rates if we get new values */
 163         if (!elems.parse_error ||
 164             !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
 165                 srlen = 0;
 166                 if (elems.supp_rates) {
 167                         clen = IEEE80211_MAX_SUPP_RATES;
 168                         if (clen > elems.supp_rates_len)
 169                                 clen = elems.supp_rates_len;
 170                         memcpy(bss->supp_rates, elems.supp_rates, clen);
 171                         srlen += clen;
 172                 }
 173                 if (elems.ext_supp_rates) {
 174                         clen = IEEE80211_MAX_SUPP_RATES - srlen;
 175                         if (clen > elems.ext_supp_rates_len)
 176                                 clen = elems.ext_supp_rates_len;
 177                         memcpy(bss->supp_rates + srlen, elems.ext_supp_rates,
 178                                clen);
 179                         srlen += clen;
 180                 }
 181                 if (srlen) {
 182                         bss->supp_rates_len = srlen;
 183                         if (!elems.parse_error)
 184                                 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 185                 }
 186         }
 187
 188         if (!elems.parse_error ||
 189             !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 190                 bss->wmm_used = elems.wmm_param || elems.wmm_info;
 191                 bss->uapsd_supported = is_uapsd_supported(&elems);
 192                 if (!elems.parse_error)
 193                         bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 194         }
 195
 196         if (beacon) {
 197                 struct ieee80211_supported_band *sband =
 198                         local->hw.wiphy->bands[rx_status->band];
 199                 if (!(rx_status->encoding == RX_ENC_HT) &&
 200                     !(rx_status->encoding == RX_ENC_VHT))
 201                         bss->beacon_rate =
 202                                 &sband->bitrates[rx_status->rate_idx];
 203         }
 204
 205         return bss;
 206 }
 207
 208 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 209                                         u32 scan_flags, const u8 *da)
 210 {
 211         if (!sdata)
 212                 return false;
 213         /* accept broadcast for OCE */
 214         if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 215             is_broadcast_ether_addr(da))
 216                 return true;
 217         if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 218                 return true;
 219         return ether_addr_equal(da, sdata->vif.addr);
 220 }
 221
 222 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 223 {
 224         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 225         struct ieee80211_sub_if_data *sdata1, *sdata2;
 226         struct ieee80211_mgmt *mgmt = (void *)skb->data;
 227         struct ieee80211_bss *bss;
 228         struct ieee80211_channel *channel;
 229
 230         if (skb->len < 24 ||
 231             (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 232              !ieee80211_is_beacon(mgmt->frame_control)))
 233                 return;
 234
 235         sdata1 = rcu_dereference(local->scan_sdata);
 236         sdata2 = rcu_dereference(local->sched_scan_sdata);
 237
 238         if (likely(!sdata1 && !sdata2))
 239                 return;
 240
 241         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 242                 struct cfg80211_scan_request *scan_req;
 243                 struct cfg80211_sched_scan_request *sched_scan_req;
 244                 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 245
 246                 scan_req = rcu_dereference(local->scan_req);
 247                 sched_scan_req = rcu_dereference(local->sched_scan_req);
 248
 249                 if (scan_req)
 250                         scan_req_flags = scan_req->flags;
 251
 252                 if (sched_scan_req)
 253                         sched_scan_req_flags = sched_scan_req->flags;
 254
 255                 /* ignore ProbeResp to foreign address or non-bcast (OCE)
 256                  * unless scanning with randomised address
 257                  */
 258                 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 259                                                  mgmt->da) &&
 260                     !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 261                                                  mgmt->da))
 262                         return;
 263         }
 264
 265         channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
 266
 267         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 268                 return;
 269
 270         bss = ieee80211_bss_info_update(local, rx_status,
 271                                         mgmt, skb->len,
 272                                         channel);
 273         if (bss)
 274                 ieee80211_rx_bss_put(local, bss);
 275 }
 276
 277 static void
 278 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 279                                enum nl80211_bss_scan_width scan_width)
 280 {
 281         memset(chandef, 0, sizeof(*chandef));
 282         switch (scan_width) {
 283         case NL80211_BSS_CHAN_WIDTH_5:
 284                 chandef->width = NL80211_CHAN_WIDTH_5;
 285                 break;
 286         case NL80211_BSS_CHAN_WIDTH_10:
 287                 chandef->width = NL80211_CHAN_WIDTH_10;
 288                 break;
 289         default:
 290                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 291                 break;
 292         }
 293 }
 294
 295 /* return false if no more work */
 296 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 297 {
 298         struct cfg80211_scan_request *req;
 299         struct cfg80211_chan_def chandef;
 300         u8 bands_used = 0;
 301         int i, ielen, n_chans;
 302         u32 flags = 0;
 303
 304         req = rcu_dereference_protected(local->scan_req,
 305                                         lockdep_is_held(&local->mtx));
 306
 307         if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 308                 return false;
 309
 310         if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 311                 for (i = 0; i < req->n_channels; i++) {
 312                         local->hw_scan_req->req.channels[i] = req->channels[i];
 313                         bands_used |= BIT(req->channels[i]->band);
 314                 }
 315
 316                 n_chans = req->n_channels;
 317         } else {
 318                 do {
 319                         if (local->hw_scan_band == NUM_NL80211_BANDS)
 320                                 return false;
 321
 322                         n_chans = 0;
 323
 324                         for (i = 0; i < req->n_channels; i++) {
 325                                 if (req->channels[i]->band !=
 326                                     local->hw_scan_band)
 327                                         continue;
 328                                 local->hw_scan_req->req.channels[n_chans] =
 329                                                         req->channels[i];
 330                                 n_chans++;
 331                                 bands_used |= BIT(req->channels[i]->band);
 332                         }
 333
 334                         local->hw_scan_band++;
 335                 } while (!n_chans);
 336         }
 337
 338         local->hw_scan_req->req.n_channels = n_chans;
 339         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 340
 341         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 342                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 343
 344         ielen = ieee80211_build_preq_ies(local,
 345                                          (u8 *)local->hw_scan_req->req.ie,
 346                                          local->hw_scan_ies_bufsize,
 347                                          &local->hw_scan_req->ies,
 348                                          req->ie, req->ie_len,
 349                                          bands_used, req->rates, &chandef,
 350                                          flags);
 351         local->hw_scan_req->req.ie_len = ielen;
 352         local->hw_scan_req->req.no_cck = req->no_cck;
 353         ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 354         ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 355                         req->mac_addr_mask);
 356         ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 357
 358         return true;
 359 }
 360
 361 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 362 {
 363         struct ieee80211_local *local = hw_to_local(hw);
 364         bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 365         bool was_scanning = local->scanning;
 366         struct cfg80211_scan_request *scan_req;
 367         struct ieee80211_sub_if_data *scan_sdata;
 368         struct ieee80211_sub_if_data *sdata;
 369
 370         lockdep_assert_held(&local->mtx);
 371
 372         /*
 373          * It's ok to abort a not-yet-running scan (that
 374          * we have one at all will be verified by checking
 375          * local->scan_req next), but not to complete it
 376          * successfully.
 377          */
 378         if (WARN_ON(!local->scanning && !aborted))
 379                 aborted = true;
 380
 381         if (WARN_ON(!local->scan_req))
 382                 return;
 383
 384         if (hw_scan && !aborted &&
 385             !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 386             ieee80211_prep_hw_scan(local)) {
 387                 int rc;
 388
 389                 rc = drv_hw_scan(local,
 390                         rcu_dereference_protected(local->scan_sdata,
 391                                                   lockdep_is_held(&local->mtx)),
 392                         local->hw_scan_req);
 393
 394                 if (rc == 0)
 395                         return;
 396
 397                 /* HW scan failed and is going to be reported as aborted,
 398                  * so clear old scan info.
 399                  */
 400                 memset(&local->scan_info, 0, sizeof(local->scan_info));
 401                 aborted = true;
 402         }
 403
 404         kfree(local->hw_scan_req);
 405         local->hw_scan_req = NULL;
 406
 407         scan_req = rcu_dereference_protected(local->scan_req,
 408                                              lockdep_is_held(&local->mtx));
 409
 410         if (scan_req != local->int_scan_req) {
 411                 local->scan_info.aborted = aborted;
 412                 cfg80211_scan_done(scan_req, &local->scan_info);
 413         }
 414         RCU_INIT_POINTER(local->scan_req, NULL);
 415
 416         scan_sdata = rcu_dereference_protected(local->scan_sdata,
 417                                                lockdep_is_held(&local->mtx));
 418         RCU_INIT_POINTER(local->scan_sdata, NULL);
 419
 420         local->scanning = 0;
 421         local->scan_chandef.chan = NULL;
 422
 423         /* Set power back to normal operating levels. */
 424         ieee80211_hw_config(local, 0);
 425
 426         if (!hw_scan) {
 427                 ieee80211_configure_filter(local);
 428                 drv_sw_scan_complete(local, scan_sdata);
 429                 ieee80211_offchannel_return(local);
 430         }
 431
 432         ieee80211_recalc_idle(local);
 433
 434         ieee80211_mlme_notify_scan_completed(local);
 435         ieee80211_ibss_notify_scan_completed(local);
 436
 437         /* Requeue all the work that might have been ignored while
 438          * the scan was in progress; if there was none this will
 439          * just be a no-op for the particular interface.
 440          */
 441         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 442                 if (ieee80211_sdata_running(sdata))
 443                         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 444         }
 445
 446         if (was_scanning)
 447                 ieee80211_start_next_roc(local);
 448 }
 449
 450 void ieee80211_scan_completed(struct ieee80211_hw *hw,
 451                               struct cfg80211_scan_info *info)
 452 {
 453         struct ieee80211_local *local = hw_to_local(hw);
 454
 455         trace_api_scan_completed(local, info->aborted);
 456
 457         set_bit(SCAN_COMPLETED, &local->scanning);
 458         if (info->aborted)
 459                 set_bit(SCAN_ABORTED, &local->scanning);
 460
 461         memcpy(&local->scan_info, info, sizeof(*info));
 462
 463         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 464 }
 465 EXPORT_SYMBOL(ieee80211_scan_completed);
 466
 467 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 468                                    struct ieee80211_sub_if_data *sdata)
 469 {
 470         /* Software scan is not supported in multi-channel cases */
 471         if (local->use_chanctx)
 472                 return -EOPNOTSUPP;
 473
 474         /*
 475          * Hardware/driver doesn't support hw_scan, so use software
 476          * scanning instead. First send a nullfunc frame with power save
 477          * bit on so that AP will buffer the frames for us while we are not
 478          * listening, then send probe requests to each channel and wait for
 479          * the responses. After all channels are scanned, tune back to the
 480          * original channel and send a nullfunc frame with power save bit
 481          * off to trigger the AP to send us all the buffered frames.
 482          *
 483          * Note that while local->sw_scanning is true everything else but
 484          * nullfunc frames and probe requests will be dropped in
 485          * ieee80211_tx_h_check_assoc().
 486          */
 487         drv_sw_scan_start(local, sdata, local->scan_addr);
 488
 489         local->leave_oper_channel_time = jiffies;
 490         local->next_scan_state = SCAN_DECISION;
 491         local->scan_channel_idx = 0;
 492
 493         ieee80211_offchannel_stop_vifs(local);
 494
 495         /* ensure nullfunc is transmitted before leaving operating channel */
 496         ieee80211_flush_queues(local, NULL, false);
 497
 498         ieee80211_configure_filter(local);
 499
 500         /* We need to set power level at maximum rate for scanning. */
 501         ieee80211_hw_config(local, 0);
 502
 503         ieee80211_queue_delayed_work(&local->hw,
 504                                      &local->scan_work, 0);
 505
 506         return 0;
 507 }
 508
 509 static bool ieee80211_can_scan(struct ieee80211_local *local,
 510                                struct ieee80211_sub_if_data *sdata)
 511 {
 512         if (ieee80211_is_radar_required(local))
 513                 return false;
 514
 515         if (!list_empty(&local->roc_list))
 516                 return false;
 517
 518         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 519             sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 520                 return false;
 521
 522         return true;
 523 }
 524
 525 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 526 {
 527         lockdep_assert_held(&local->mtx);
 528
 529         if (!local->scan_req || local->scanning)
 530                 return;
 531
 532         if (!ieee80211_can_scan(local,
 533                                 rcu_dereference_protected(
 534                                         local->scan_sdata,
 535                                         lockdep_is_held(&local->mtx))))
 536                 return;
 537
 538         ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 539                                      round_jiffies_relative(0));
 540 }
 541
 542 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 543                                           const u8 *src, const u8 *dst,
 544                                           const u8 *ssid, size_t ssid_len,
 545                                           const u8 *ie, size_t ie_len,
 546                                           u32 ratemask, u32 flags, u32 tx_flags,
 547                                           struct ieee80211_channel *channel)
 548 {
 549         struct sk_buff *skb;
 550         u32 txdata_flags = 0;
 551
 552         skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 553                                         ssid, ssid_len,
 554                                         ie, ie_len, flags);
 555
 556         if (skb) {
 557                 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 558                         struct ieee80211_hdr *hdr = (void *)skb->data;
 559                         u16 sn = get_random_u32();
 560
 561                         txdata_flags |= IEEE80211_TX_NO_SEQNO;
 562                         hdr->seq_ctrl =
 563                                 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 564                 }
 565                 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 566                 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
 567                                           txdata_flags);
 568         }
 569 }
 570
 571 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 572                                             unsigned long *next_delay)
 573 {
 574         int i;
 575         struct ieee80211_sub_if_data *sdata;
 576         struct cfg80211_scan_request *scan_req;
 577         enum nl80211_band band = local->hw.conf.chandef.chan->band;
 578         u32 flags = 0, tx_flags;
 579
 580         scan_req = rcu_dereference_protected(local->scan_req,
 581                                              lockdep_is_held(&local->mtx));
 582
 583         tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 584         if (scan_req->no_cck)
 585                 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 586         if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 587                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 588         if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 589                 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 590
 591         sdata = rcu_dereference_protected(local->scan_sdata,
 592                                           lockdep_is_held(&local->mtx));
 593
 594         for (i = 0; i < scan_req->n_ssids; i++)
 595                 ieee80211_send_scan_probe_req(
 596                         sdata, local->scan_addr, scan_req->bssid,
 597                         scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 598                         scan_req->ie, scan_req->ie_len,
 599                         scan_req->rates[band], flags,
 600                         tx_flags, local->hw.conf.chandef.chan);
 601
 602         /*
 603          * After sending probe requests, wait for probe responses
 604          * on the channel.
 605          */
 606         *next_delay = IEEE80211_CHANNEL_TIME;
 607         local->next_scan_state = SCAN_DECISION;
 608 }
 609
 610 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 611                                   struct cfg80211_scan_request *req)
 612 {
 613         struct ieee80211_local *local = sdata->local;
 614         bool hw_scan = local->ops->hw_scan;
 615         int rc;
 616
 617         lockdep_assert_held(&local->mtx);
 618
 619         if (local->scan_req || ieee80211_is_radar_required(local))
 620                 return -EBUSY;
 621
 622         if (!ieee80211_can_scan(local, sdata)) {
 623                 /* wait for the work to finish/time out */
 624                 rcu_assign_pointer(local->scan_req, req);
 625                 rcu_assign_pointer(local->scan_sdata, sdata);
 626                 return 0;
 627         }
 628
 629  again:
 630         if (hw_scan) {
 631                 u8 *ies;
 632
 633                 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 634
 635                 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 636                         int i, n_bands = 0;
 637                         u8 bands_counted = 0;
 638
 639                         for (i = 0; i < req->n_channels; i++) {
 640                                 if (bands_counted & BIT(req->channels[i]->band))
 641                                         continue;
 642                                 bands_counted |= BIT(req->channels[i]->band);
 643                                 n_bands++;
 644                         }
 645
 646                         local->hw_scan_ies_bufsize *= n_bands;
 647                 }
 648
 649                 local->hw_scan_req = kmalloc(
 650                                 sizeof(*local->hw_scan_req) +
 651                                 req->n_channels * sizeof(req->channels[0]) +
 652                                 local->hw_scan_ies_bufsize, GFP_KERNEL);
 653                 if (!local->hw_scan_req)
 654                         return -ENOMEM;
 655
 656                 local->hw_scan_req->req.ssids = req->ssids;
 657                 local->hw_scan_req->req.n_ssids = req->n_ssids;
 658                 ies = (u8 *)local->hw_scan_req +
 659                         sizeof(*local->hw_scan_req) +
 660                         req->n_channels * sizeof(req->channels[0]);
 661                 local->hw_scan_req->req.ie = ies;
 662                 local->hw_scan_req->req.flags = req->flags;
 663                 eth_broadcast_addr(local->hw_scan_req->req.bssid);
 664                 local->hw_scan_req->req.duration = req->duration;
 665                 local->hw_scan_req->req.duration_mandatory =
 666                         req->duration_mandatory;
 667
 668                 local->hw_scan_band = 0;
 669
 670                 /*
 671                  * After allocating local->hw_scan_req, we must
 672                  * go through until ieee80211_prep_hw_scan(), so
 673                  * anything that might be changed here and leave
 674                  * this function early must not go after this
 675                  * allocation.
 676                  */
 677         }
 678
 679         rcu_assign_pointer(local->scan_req, req);
 680         rcu_assign_pointer(local->scan_sdata, sdata);
 681
 682         if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 683                 get_random_mask_addr(local->scan_addr,
 684                                      req->mac_addr,
 685                                      req->mac_addr_mask);
 686         else
 687                 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 688
 689         if (hw_scan) {
 690                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 691         } else if ((req->n_channels == 1) &&
 692                    (req->channels[0] == local->_oper_chandef.chan)) {
 693                 /*
 694                  * If we are scanning only on the operating channel
 695                  * then we do not need to stop normal activities
 696                  */
 697                 unsigned long next_delay;
 698
 699                 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 700
 701                 ieee80211_recalc_idle(local);
 702
 703                 /* Notify driver scan is starting, keep order of operations
 704                  * same as normal software scan, in case that matters. */
 705                 drv_sw_scan_start(local, sdata, local->scan_addr);
 706
 707                 ieee80211_configure_filter(local); /* accept probe-responses */
 708
 709                 /* We need to ensure power level is at max for scanning. */
 710                 ieee80211_hw_config(local, 0);
 711
 712                 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 713                                                 IEEE80211_CHAN_RADAR)) ||
 714                     !req->n_ssids) {
 715                         next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 716                 } else {
 717                         ieee80211_scan_state_send_probe(local, &next_delay);
 718                         next_delay = IEEE80211_CHANNEL_TIME;
 719                 }
 720
 721                 /* Now, just wait a bit and we are all done! */
 722                 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 723                                              next_delay);
 724                 return 0;
 725         } else {
 726                 /* Do normal software scan */
 727                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 728         }
 729
 730         ieee80211_recalc_idle(local);
 731
 732         if (hw_scan) {
 733                 WARN_ON(!ieee80211_prep_hw_scan(local));
 734                 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 735         } else {
 736                 rc = ieee80211_start_sw_scan(local, sdata);
 737         }
 738
 739         if (rc) {
 740                 kfree(local->hw_scan_req);
 741                 local->hw_scan_req = NULL;
 742                 local->scanning = 0;
 743
 744                 ieee80211_recalc_idle(local);
 745
 746                 local->scan_req = NULL;
 747                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 748         }
 749
 750         if (hw_scan && rc == 1) {
 751                 /*
 752                  * we can't fall back to software for P2P-GO
 753                  * as it must update NoA etc.
 754                  */
 755                 if (ieee80211_vif_type_p2p(&sdata->vif) ==
 756                                 NL80211_IFTYPE_P2P_GO)
 757                         return -EOPNOTSUPP;
 758                 hw_scan = false;
 759                 goto again;
 760         }
 761
 762         return rc;
 763 }
 764
 765 static unsigned long
 766 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 767 {
 768         /*
 769          * TODO: channel switching also consumes quite some time,
 770          * add that delay as well to get a better estimation
 771          */
 772         if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 773                 return IEEE80211_PASSIVE_CHANNEL_TIME;
 774         return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 775 }
 776
 777 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 778                                           unsigned long *next_delay)
 779 {
 780         bool associated = false;
 781         bool tx_empty = true;
 782         bool bad_latency;
 783         struct ieee80211_sub_if_data *sdata;
 784         struct ieee80211_channel *next_chan;
 785         enum mac80211_scan_state next_scan_state;
 786         struct cfg80211_scan_request *scan_req;
 787
 788         /*
 789          * check if at least one STA interface is associated,
 790          * check if at least one STA interface has pending tx frames
 791          * and grab the lowest used beacon interval
 792          */
 793         mutex_lock(&local->iflist_mtx);
 794         list_for_each_entry(sdata, &local->interfaces, list) {
 795                 if (!ieee80211_sdata_running(sdata))
 796                         continue;
 797
 798                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 799                         if (sdata->u.mgd.associated) {
 800                                 associated = true;
 801
 802                                 if (!qdisc_all_tx_empty(sdata->dev)) {
 803                                         tx_empty = false;
 804                                         break;
 805                                 }
 806                         }
 807                 }
 808         }
 809         mutex_unlock(&local->iflist_mtx);
 810
 811         scan_req = rcu_dereference_protected(local->scan_req,
 812                                              lockdep_is_held(&local->mtx));
 813
 814         next_chan = scan_req->channels[local->scan_channel_idx];
 815
 816         /*
 817          * we're currently scanning a different channel, let's
 818          * see if we can scan another channel without interfering
 819          * with the current traffic situation.
 820          *
 821          * Keep good latency, do not stay off-channel more than 125 ms.
 822          */
 823
 824         bad_latency = time_after(jiffies +
 825                                  ieee80211_scan_get_channel_time(next_chan),
 826                                  local->leave_oper_channel_time + HZ / 8);
 827
 828         if (associated && !tx_empty) {
 829                 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 830                         next_scan_state = SCAN_ABORT;
 831                 else
 832                         next_scan_state = SCAN_SUSPEND;
 833         } else if (associated && bad_latency) {
 834                 next_scan_state = SCAN_SUSPEND;
 835         } else {
 836                 next_scan_state = SCAN_SET_CHANNEL;
 837         }
 838
 839         local->next_scan_state = next_scan_state;
 840
 841         *next_delay = 0;
 842 }
 843
 844 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 845                                              unsigned long *next_delay)
 846 {
 847         int skip;
 848         struct ieee80211_channel *chan;
 849         enum nl80211_bss_scan_width oper_scan_width;
 850         struct cfg80211_scan_request *scan_req;
 851
 852         scan_req = rcu_dereference_protected(local->scan_req,
 853                                              lockdep_is_held(&local->mtx));
 854
 855         skip = 0;
 856         chan = scan_req->channels[local->scan_channel_idx];
 857
 858         local->scan_chandef.chan = chan;
 859         local->scan_chandef.center_freq1 = chan->center_freq;
 860         local->scan_chandef.center_freq2 = 0;
 861         switch (scan_req->scan_width) {
 862         case NL80211_BSS_CHAN_WIDTH_5:
 863                 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 864                 break;
 865         case NL80211_BSS_CHAN_WIDTH_10:
 866                 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 867                 break;
 868         case NL80211_BSS_CHAN_WIDTH_20:
 869                 /* If scanning on oper channel, use whatever channel-type
 870                  * is currently in use.
 871                  */
 872                 oper_scan_width = cfg80211_chandef_to_scan_width(
 873                                         &local->_oper_chandef);
 874                 if (chan == local->_oper_chandef.chan &&
 875                     oper_scan_width == scan_req->scan_width)
 876                         local->scan_chandef = local->_oper_chandef;
 877                 else
 878                         local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 879                 break;
 880         }
 881
 882         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 883                 skip = 1;
 884
 885         /* advance state machine to next channel/band */
 886         local->scan_channel_idx++;
 887
 888         if (skip) {
 889                 /* if we skip this channel return to the decision state */
 890                 local->next_scan_state = SCAN_DECISION;
 891                 return;
 892         }
 893
 894         /*
 895          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 896          * (which unfortunately doesn't say _why_ step a) is done,
 897          * but it waits for the probe delay or until a frame is
 898          * received - and the received frame would update the NAV).
 899          * For now, we do not support waiting until a frame is
 900          * received.
 901          *
 902          * In any case, it is not necessary for a passive scan.
 903          */
 904         if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 905             !scan_req->n_ssids) {
 906                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 907                 local->next_scan_state = SCAN_DECISION;
 908                 return;
 909         }
 910
 911         /* active scan, send probes */
 912         *next_delay = IEEE80211_PROBE_DELAY;
 913         local->next_scan_state = SCAN_SEND_PROBE;
 914 }
 915
 916 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 917                                          unsigned long *next_delay)
 918 {
 919         /* switch back to the operating channel */
 920         local->scan_chandef.chan = NULL;
 921         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 922
 923         /* disable PS */
 924         ieee80211_offchannel_return(local);
 925
 926         *next_delay = HZ / 5;
 927         /* afterwards, resume scan & go to next channel */
 928         local->next_scan_state = SCAN_RESUME;
 929 }
 930
 931 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
 932                                         unsigned long *next_delay)
 933 {
 934         ieee80211_offchannel_stop_vifs(local);
 935
 936         if (local->ops->flush) {
 937                 ieee80211_flush_queues(local, NULL, false);
 938                 *next_delay = 0;
 939         } else
 940                 *next_delay = HZ / 10;
 941
 942         /* remember when we left the operating channel */
 943         local->leave_oper_channel_time = jiffies;
 944
 945         /* advance to the next channel to be scanned */
 946         local->next_scan_state = SCAN_SET_CHANNEL;
 947 }
 948
 949 void ieee80211_scan_work(struct work_struct *work)
 950 {
 951         struct ieee80211_local *local =
 952                 container_of(work, struct ieee80211_local, scan_work.work);
 953         struct ieee80211_sub_if_data *sdata;
 954         struct cfg80211_scan_request *scan_req;
 955         unsigned long next_delay = 0;
 956         bool aborted;
 957
 958         mutex_lock(&local->mtx);
 959
 960         if (!ieee80211_can_run_worker(local)) {
 961                 aborted = true;
 962                 goto out_complete;
 963         }
 964
 965         sdata = rcu_dereference_protected(local->scan_sdata,
 966                                           lockdep_is_held(&local->mtx));
 967         scan_req = rcu_dereference_protected(local->scan_req,
 968                                              lockdep_is_held(&local->mtx));
 969
 970         /* When scanning on-channel, the first-callback means completed. */
 971         if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
 972                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 973                 goto out_complete;
 974         }
 975
 976         if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
 977                 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 978                 goto out_complete;
 979         }
 980
 981         if (!sdata || !scan_req)
 982                 goto out;
 983
 984         if (!local->scanning) {
 985                 int rc;
 986
 987                 RCU_INIT_POINTER(local->scan_req, NULL);
 988                 RCU_INIT_POINTER(local->scan_sdata, NULL);
 989
 990                 rc = __ieee80211_start_scan(sdata, scan_req);
 991                 if (rc) {
 992                         /* need to complete scan in cfg80211 */
 993                         rcu_assign_pointer(local->scan_req, scan_req);
 994                         aborted = true;
 995                         goto out_complete;
 996                 } else
 997                         goto out;
 998         }
 999
1000         /*
1001          * as long as no delay is required advance immediately
1002          * without scheduling a new work
1003          */
1004         do {
1005                 if (!ieee80211_sdata_running(sdata)) {
1006                         aborted = true;
1007                         goto out_complete;
1008                 }
1009
1010                 switch (local->next_scan_state) {
1011                 case SCAN_DECISION:
1012                         /* if no more bands/channels left, complete scan */
1013                         if (local->scan_channel_idx >= scan_req->n_channels) {
1014                                 aborted = false;
1015                                 goto out_complete;
1016                         }
1017                         ieee80211_scan_state_decision(local, &next_delay);
1018                         break;
1019                 case SCAN_SET_CHANNEL:
1020                         ieee80211_scan_state_set_channel(local, &next_delay);
1021                         break;
1022                 case SCAN_SEND_PROBE:
1023                         ieee80211_scan_state_send_probe(local, &next_delay);
1024                         break;
1025                 case SCAN_SUSPEND:
1026                         ieee80211_scan_state_suspend(local, &next_delay);
1027                         break;
1028                 case SCAN_RESUME:
1029                         ieee80211_scan_state_resume(local, &next_delay);
1030                         break;
1031                 case SCAN_ABORT:
1032                         aborted = true;
1033                         goto out_complete;
1034                 }
1035         } while (next_delay == 0);
1036
1037         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1038         goto out;
1039
1040 out_complete:
1041         __ieee80211_scan_completed(&local->hw, aborted);
1042 out:
1043         mutex_unlock(&local->mtx);
1044 }
1045
1046 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1047                            struct cfg80211_scan_request *req)
1048 {
1049         int res;
1050
1051         mutex_lock(&sdata->local->mtx);
1052         res = __ieee80211_start_scan(sdata, req);
1053         mutex_unlock(&sdata->local->mtx);
1054
1055         return res;
1056 }
1057
1058 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1059                                 const u8 *ssid, u8 ssid_len,
1060                                 struct ieee80211_channel **channels,
1061                                 unsigned int n_channels,
1062                                 enum nl80211_bss_scan_width scan_width)
1063 {
1064         struct ieee80211_local *local = sdata->local;
1065         int ret = -EBUSY, i, n_ch = 0;
1066         enum nl80211_band band;
1067
1068         mutex_lock(&local->mtx);
1069
1070         /* busy scanning */
1071         if (local->scan_req)
1072                 goto unlock;
1073
1074         /* fill internal scan request */
1075         if (!channels) {
1076                 int max_n;
1077
1078                 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1079                         if (!local->hw.wiphy->bands[band])
1080                                 continue;
1081
1082                         max_n = local->hw.wiphy->bands[band]->n_channels;
1083                         for (i = 0; i < max_n; i++) {
1084                                 struct ieee80211_channel *tmp_ch =
1085                                     &local->hw.wiphy->bands[band]->channels[i];
1086
1087                                 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1088                                                      IEEE80211_CHAN_DISABLED))
1089                                         continue;
1090
1091                                 local->int_scan_req->channels[n_ch] = tmp_ch;
1092                                 n_ch++;
1093                         }
1094                 }
1095
1096                 if (WARN_ON_ONCE(n_ch == 0))
1097                         goto unlock;
1098
1099                 local->int_scan_req->n_channels = n_ch;
1100         } else {
1101                 for (i = 0; i < n_channels; i++) {
1102                         if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1103                                                   IEEE80211_CHAN_DISABLED))
1104                                 continue;
1105
1106                         local->int_scan_req->channels[n_ch] = channels[i];
1107                         n_ch++;
1108                 }
1109
1110                 if (WARN_ON_ONCE(n_ch == 0))
1111                         goto unlock;
1112
1113                 local->int_scan_req->n_channels = n_ch;
1114         }
1115
1116         local->int_scan_req->ssids = &local->scan_ssid;
1117         local->int_scan_req->n_ssids = 1;
1118         local->int_scan_req->scan_width = scan_width;
1119         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1120         local->int_scan_req->ssids[0].ssid_len = ssid_len;
1121
1122         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1123  unlock:
1124         mutex_unlock(&local->mtx);
1125         return ret;
1126 }
1127
1128 /*
1129  * Only call this function when a scan can't be queued -- under RTNL.
1130  */
1131 void ieee80211_scan_cancel(struct ieee80211_local *local)
1132 {
1133         /*
1134          * We are canceling software scan, or deferred scan that was not
1135          * yet really started (see __ieee80211_start_scan ).
1136          *
1137          * Regarding hardware scan:
1138          * - we can not call  __ieee80211_scan_completed() as when
1139          *   SCAN_HW_SCANNING bit is set this function change
1140          *   local->hw_scan_req to operate on 5G band, what race with
1141          *   driver which can use local->hw_scan_req
1142          *
1143          * - we can not cancel scan_work since driver can schedule it
1144          *   by ieee80211_scan_completed(..., true) to finish scan
1145          *
1146          * Hence we only call the cancel_hw_scan() callback, but the low-level
1147          * driver is still responsible for calling ieee80211_scan_completed()
1148          * after the scan was completed/aborted.
1149          */
1150
1151         mutex_lock(&local->mtx);
1152         if (!local->scan_req)
1153                 goto out;
1154
1155         /*
1156          * We have a scan running and the driver already reported completion,
1157          * but the worker hasn't run yet or is stuck on the mutex - mark it as
1158          * cancelled.
1159          */
1160         if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1161             test_bit(SCAN_COMPLETED, &local->scanning)) {
1162                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1163                 goto out;
1164         }
1165
1166         if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1167                 /*
1168                  * Make sure that __ieee80211_scan_completed doesn't trigger a
1169                  * scan on another band.
1170                  */
1171                 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1172                 if (local->ops->cancel_hw_scan)
1173                         drv_cancel_hw_scan(local,
1174                                 rcu_dereference_protected(local->scan_sdata,
1175                                                 lockdep_is_held(&local->mtx)));
1176                 goto out;
1177         }
1178
1179         /*
1180          * If the work is currently running, it must be blocked on
1181          * the mutex, but we'll set scan_sdata = NULL and it'll
1182          * simply exit once it acquires the mutex.
1183          */
1184         cancel_delayed_work(&local->scan_work);
1185         /* and clean up */
1186         memset(&local->scan_info, 0, sizeof(local->scan_info));
1187         __ieee80211_scan_completed(&local->hw, true);
1188 out:
1189         mutex_unlock(&local->mtx);
1190 }
1191
1192 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1193                                         struct cfg80211_sched_scan_request *req)
1194 {
1195         struct ieee80211_local *local = sdata->local;
1196         struct ieee80211_scan_ies sched_scan_ies = {};
1197         struct cfg80211_chan_def chandef;
1198         int ret, i, iebufsz, num_bands = 0;
1199         u32 rate_masks[NUM_NL80211_BANDS] = {};
1200         u8 bands_used = 0;
1201         u8 *ie;
1202         u32 flags = 0;
1203
1204         iebufsz = local->scan_ies_len + req->ie_len;
1205
1206         lockdep_assert_held(&local->mtx);
1207
1208         if (!local->ops->sched_scan_start)
1209                 return -ENOTSUPP;
1210
1211         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1212                 if (local->hw.wiphy->bands[i]) {
1213                         bands_used |= BIT(i);
1214                         rate_masks[i] = (u32) -1;
1215                         num_bands++;
1216                 }
1217         }
1218
1219         if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1220                 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1221
1222         ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1223         if (!ie) {
1224                 ret = -ENOMEM;
1225                 goto out;
1226         }
1227
1228         ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1229
1230         ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1231                                  &sched_scan_ies, req->ie,
1232                                  req->ie_len, bands_used, rate_masks, &chandef,
1233                                  flags);
1234
1235         ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1236         if (ret == 0) {
1237                 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1238                 rcu_assign_pointer(local->sched_scan_req, req);
1239         }
1240
1241         kfree(ie);
1242
1243 out:
1244         if (ret) {
1245                 /* Clean in case of failure after HW restart or upon resume. */
1246                 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1247                 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1248         }
1249
1250         return ret;
1251 }
1252
1253 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1254                                        struct cfg80211_sched_scan_request *req)
1255 {
1256         struct ieee80211_local *local = sdata->local;
1257         int ret;
1258
1259         mutex_lock(&local->mtx);
1260
1261         if (rcu_access_pointer(local->sched_scan_sdata)) {
1262                 mutex_unlock(&local->mtx);
1263                 return -EBUSY;
1264         }
1265
1266         ret = __ieee80211_request_sched_scan_start(sdata, req);
1267
1268         mutex_unlock(&local->mtx);
1269         return ret;
1270 }
1271
1272 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1273 {
1274         struct ieee80211_sub_if_data *sched_scan_sdata;
1275         int ret = -ENOENT;
1276
1277         mutex_lock(&local->mtx);
1278
1279         if (!local->ops->sched_scan_stop) {
1280                 ret = -ENOTSUPP;
1281                 goto out;
1282         }
1283
1284         /* We don't want to restart sched scan anymore. */
1285         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1286
1287         sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1288                                                 lockdep_is_held(&local->mtx));
1289         if (sched_scan_sdata) {
1290                 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1291                 if (!ret)
1292                         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1293         }
1294 out:
1295         mutex_unlock(&local->mtx);
1296
1297         return ret;
1298 }
1299
1300 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1301 {
1302         struct ieee80211_local *local = hw_to_local(hw);
1303
1304         trace_api_sched_scan_results(local);
1305
1306         cfg80211_sched_scan_results(hw->wiphy, 0);
1307 }
1308 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1309
1310 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1311 {
1312         mutex_lock(&local->mtx);
1313
1314         if (!rcu_access_pointer(local->sched_scan_sdata)) {
1315                 mutex_unlock(&local->mtx);
1316                 return;
1317         }
1318
1319         RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1320
1321         /* If sched scan was aborted by the driver. */
1322         RCU_INIT_POINTER(local->sched_scan_req, NULL);
1323
1324         mutex_unlock(&local->mtx);
1325
1326         cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1327 }
1328
1329 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1330 {
1331         struct ieee80211_local *local =
1332                 container_of(work, struct ieee80211_local,
1333                              sched_scan_stopped_work);
1334
1335         ieee80211_sched_scan_end(local);
1336 }
1337
1338 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1339 {
1340         struct ieee80211_local *local = hw_to_local(hw);
1341
1342         trace_api_sched_scan_stopped(local);
1343
1344         /*
1345          * this shouldn't really happen, so for simplicity
1346          * simply ignore it, and let mac80211 reconfigure
1347          * the sched scan later on.
1348          */
1349         if (local->in_reconfig)
1350                 return;
1351
1352         schedule_work(&local->sched_scan_stopped_work);
1353 }
1354 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);