SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/if_arp.h>
  16 #include <linux/rtnetlink.h>
  17 #include <linux/slab.h>
  18 #include <net/mac80211.h>
  19
  20 #include "ieee80211_i.h"
  21 #include "driver-ops.h"
  22 #include "mesh.h"
  23
  24 #define IEEE80211_PROBE_DELAY (HZ / 33)
  25 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  26 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8)
  27
  28 struct ieee80211_bss *
  29 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
  30                      u8 *ssid, u8 ssid_len)
  31 {
  32         struct cfg80211_bss *cbss;
  33
  34         cbss = cfg80211_get_bss(local->hw.wiphy,
  35                                 ieee80211_get_channel(local->hw.wiphy, freq),
  36                                 bssid, ssid, ssid_len, 0, 0);
  37         if (!cbss)
  38                 return NULL;
  39         return (void *)cbss->priv;
  40 }
  41
  42 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
  43 {
  44         struct ieee80211_bss *bss = (void *)cbss->priv;
  45
  46         kfree(bss_mesh_id(bss));
  47         kfree(bss_mesh_cfg(bss));
  48 }
  49
  50 void ieee80211_rx_bss_put(struct ieee80211_local *local,
  51                           struct ieee80211_bss *bss)
  52 {
  53         if (!bss)
  54                 return;
  55         cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
  56 }
  57
  58 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  59 {
  60         u8 qos_info;
  61
  62         if (elems->wmm_info && elems->wmm_info_len == 7
  63             && elems->wmm_info[5] == 1)
  64                 qos_info = elems->wmm_info[6];
  65         else if (elems->wmm_param && elems->wmm_param_len == 24
  66                  && elems->wmm_param[5] == 1)
  67                 qos_info = elems->wmm_param[6];
  68         else
  69                 /* no valid wmm information or parameter element found */
  70                 return false;
  71
  72         return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  73 }
  74
  75 struct ieee80211_bss *
  76 ieee80211_bss_info_update(struct ieee80211_local *local,
  77                           struct ieee80211_rx_status *rx_status,
  78                           struct ieee80211_mgmt *mgmt,
  79                           size_t len,
  80                           struct ieee802_11_elems *elems,
  81                           struct ieee80211_channel *channel,
  82                           bool beacon)
  83 {
  84         struct cfg80211_bss *cbss;
  85         struct ieee80211_bss *bss;
  86         int clen;
  87         s32 signal = 0;
  88
  89         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  90                 signal = rx_status->signal * 100;
  91         else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
  92                 signal = (rx_status->signal * 100) / local->hw.max_signal;
  93
  94         cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
  95                                          mgmt, len, signal, GFP_ATOMIC);
  96
  97         if (!cbss)
  98                 return NULL;
  99
 100         cbss->free_priv = ieee80211_rx_bss_free;
 101         bss = (void *)cbss->priv;
 102
 103         /* save the ERP value so that it is available at association time */
 104         if (elems->erp_info && elems->erp_info_len >= 1) {
 105                 bss->erp_value = elems->erp_info[0];
 106                 bss->has_erp_value = 1;
 107         }
 108
 109         if (elems->tim) {
 110                 struct ieee80211_tim_ie *tim_ie =
 111                         (struct ieee80211_tim_ie *)elems->tim;
 112                 bss->dtim_period = tim_ie->dtim_period;
 113         }
 114
 115         bss->supp_rates_len = 0;
 116         if (elems->supp_rates) {
 117                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 118                 if (clen > elems->supp_rates_len)
 119                         clen = elems->supp_rates_len;
 120                 memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
 121                        clen);
 122                 bss->supp_rates_len += clen;
 123         }
 124         if (elems->ext_supp_rates) {
 125                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 126                 if (clen > elems->ext_supp_rates_len)
 127                         clen = elems->ext_supp_rates_len;
 128                 memcpy(&bss->supp_rates[bss->supp_rates_len],
 129                        elems->ext_supp_rates, clen);
 130                 bss->supp_rates_len += clen;
 131         }
 132
 133         bss->wmm_used = elems->wmm_param || elems->wmm_info;
 134         bss->uapsd_supported = is_uapsd_supported(elems);
 135
 136         if (!beacon)
 137                 bss->last_probe_resp = jiffies;
 138
 139         return bss;
 140 }
 141
 142 ieee80211_rx_result
 143 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 144 {
 145         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 146         struct ieee80211_mgmt *mgmt;
 147         struct ieee80211_bss *bss;
 148         u8 *elements;
 149         struct ieee80211_channel *channel;
 150         size_t baselen;
 151         int freq;
 152         __le16 fc;
 153         bool presp, beacon = false;
 154         struct ieee802_11_elems elems;
 155
 156         if (skb->len < 2)
 157                 return RX_DROP_UNUSABLE;
 158
 159         mgmt = (struct ieee80211_mgmt *) skb->data;
 160         fc = mgmt->frame_control;
 161
 162         if (ieee80211_is_ctl(fc))
 163                 return RX_CONTINUE;
 164
 165         if (skb->len < 24)
 166                 return RX_DROP_MONITOR;
 167
 168         presp = ieee80211_is_probe_resp(fc);
 169         if (presp) {
 170                 /* ignore ProbeResp to foreign address */
 171                 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 172                         return RX_DROP_MONITOR;
 173
 174                 presp = true;
 175                 elements = mgmt->u.probe_resp.variable;
 176                 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
 177         } else {
 178                 beacon = ieee80211_is_beacon(fc);
 179                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 180                 elements = mgmt->u.beacon.variable;
 181         }
 182
 183         if (!presp && !beacon)
 184                 return RX_CONTINUE;
 185
 186         if (baselen > skb->len)
 187                 return RX_DROP_MONITOR;
 188
 189         ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
 190
 191         if (elems.ds_params && elems.ds_params_len == 1)
 192                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 193         else
 194                 freq = rx_status->freq;
 195
 196         channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
 197
 198         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 199                 return RX_DROP_MONITOR;
 200
 201         bss = ieee80211_bss_info_update(sdata->local, rx_status,
 202                                         mgmt, skb->len, &elems,
 203                                         channel, beacon);
 204         if (bss)
 205                 ieee80211_rx_bss_put(sdata->local, bss);
 206
 207         dev_kfree_skb(skb);
 208         return RX_QUEUED;
 209 }
 210
 211 /* return false if no more work */
 212 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 213 {
 214         struct cfg80211_scan_request *req = local->scan_req;
 215         enum ieee80211_band band;
 216         int i, ielen, n_chans;
 217
 218         do {
 219                 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
 220                         return false;
 221
 222                 band = local->hw_scan_band;
 223                 n_chans = 0;
 224                 for (i = 0; i < req->n_channels; i++) {
 225                         if (req->channels[i]->band == band) {
 226                                 local->hw_scan_req->channels[n_chans] =
 227                                                         req->channels[i];
 228                                 n_chans++;
 229                         }
 230                 }
 231
 232                 local->hw_scan_band++;
 233         } while (!n_chans);
 234
 235         local->hw_scan_req->n_channels = n_chans;
 236
 237         ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
 238                                          req->ie, req->ie_len, band);
 239         local->hw_scan_req->ie_len = ielen;
 240
 241         return true;
 242 }
 243
 244 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 245 {
 246         struct ieee80211_local *local = hw_to_local(hw);
 247         bool was_hw_scan;
 248
 249         mutex_lock(&local->scan_mtx);
 250
 251         /*
 252          * It's ok to abort a not-yet-running scan (that
 253          * we have one at all will be verified by checking
 254          * local->scan_req next), but not to complete it
 255          * successfully.
 256          */
 257         if (WARN_ON(!local->scanning && !aborted))
 258                 aborted = true;
 259
 260         if (WARN_ON(!local->scan_req)) {
 261                 mutex_unlock(&local->scan_mtx);
 262                 return;
 263         }
 264
 265         was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 266         if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
 267                 ieee80211_queue_delayed_work(&local->hw,
 268                                              &local->scan_work, 0);
 269                 mutex_unlock(&local->scan_mtx);
 270                 return;
 271         }
 272
 273         kfree(local->hw_scan_req);
 274         local->hw_scan_req = NULL;
 275
 276         if (local->scan_req != local->int_scan_req)
 277                 cfg80211_scan_done(local->scan_req, aborted);
 278         local->scan_req = NULL;
 279         local->scan_sdata = NULL;
 280
 281         local->scanning = 0;
 282         local->scan_channel = NULL;
 283
 284         /* we only have to protect scan_req and hw/sw scan */
 285         mutex_unlock(&local->scan_mtx);
 286
 287         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 288         if (was_hw_scan)
 289                 goto done;
 290
 291         ieee80211_configure_filter(local);
 292
 293         drv_sw_scan_complete(local);
 294
 295         ieee80211_offchannel_return(local, true);
 296
 297  done:
 298         ieee80211_recalc_idle(local);
 299         ieee80211_mlme_notify_scan_completed(local);
 300         ieee80211_ibss_notify_scan_completed(local);
 301         ieee80211_mesh_notify_scan_completed(local);
 302         ieee80211_queue_work(&local->hw, &local->work_work);
 303 }
 304 EXPORT_SYMBOL(ieee80211_scan_completed);
 305
 306 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 307 {
 308         /*
 309          * Hardware/driver doesn't support hw_scan, so use software
 310          * scanning instead. First send a nullfunc frame with power save
 311          * bit on so that AP will buffer the frames for us while we are not
 312          * listening, then send probe requests to each channel and wait for
 313          * the responses. After all channels are scanned, tune back to the
 314          * original channel and send a nullfunc frame with power save bit
 315          * off to trigger the AP to send us all the buffered frames.
 316          *
 317          * Note that while local->sw_scanning is true everything else but
 318          * nullfunc frames and probe requests will be dropped in
 319          * ieee80211_tx_h_check_assoc().
 320          */
 321         drv_sw_scan_start(local);
 322
 323         ieee80211_offchannel_stop_beaconing(local);
 324
 325         local->next_scan_state = SCAN_DECISION;
 326         local->scan_channel_idx = 0;
 327
 328         drv_flush(local, false);
 329
 330         ieee80211_configure_filter(local);
 331
 332         ieee80211_queue_delayed_work(&local->hw,
 333                                      &local->scan_work,
 334                                      IEEE80211_CHANNEL_TIME);
 335
 336         return 0;
 337 }
 338
 339
 340 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 341                                   struct cfg80211_scan_request *req)
 342 {
 343         struct ieee80211_local *local = sdata->local;
 344         int rc;
 345
 346         if (local->scan_req)
 347                 return -EBUSY;
 348
 349         if (!list_empty(&local->work_list)) {
 350                 /* wait for the work to finish/time out */
 351                 local->scan_req = req;
 352                 local->scan_sdata = sdata;
 353                 return 0;
 354         }
 355
 356         if (local->ops->hw_scan) {
 357                 u8 *ies;
 358
 359                 local->hw_scan_req = kmalloc(
 360                                 sizeof(*local->hw_scan_req) +
 361                                 req->n_channels * sizeof(req->channels[0]) +
 362                                 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
 363                                 req->ie_len, GFP_KERNEL);
 364                 if (!local->hw_scan_req)
 365                         return -ENOMEM;
 366
 367                 local->hw_scan_req->ssids = req->ssids;
 368                 local->hw_scan_req->n_ssids = req->n_ssids;
 369                 ies = (u8 *)local->hw_scan_req +
 370                         sizeof(*local->hw_scan_req) +
 371                         req->n_channels * sizeof(req->channels[0]);
 372                 local->hw_scan_req->ie = ies;
 373
 374                 local->hw_scan_band = 0;
 375
 376                 /*
 377                  * After allocating local->hw_scan_req, we must
 378                  * go through until ieee80211_prep_hw_scan(), so
 379                  * anything that might be changed here and leave
 380                  * this function early must not go after this
 381                  * allocation.
 382                  */
 383         }
 384
 385         local->scan_req = req;
 386         local->scan_sdata = sdata;
 387
 388         if (local->ops->hw_scan)
 389                 __set_bit(SCAN_HW_SCANNING, &local->scanning);
 390         else
 391                 __set_bit(SCAN_SW_SCANNING, &local->scanning);
 392
 393         /*
 394          * Kicking off the scan need not be protected,
 395          * only the scan variable stuff, since now
 396          * local->scan_req is assigned and other callers
 397          * will abort their scan attempts.
 398          *
 399          * This avoids too many locking dependencies
 400          * so that the scan completed calls have more
 401          * locking freedom.
 402          */
 403
 404         ieee80211_recalc_idle(local);
 405         mutex_unlock(&local->scan_mtx);
 406
 407         if (local->ops->hw_scan) {
 408                 WARN_ON(!ieee80211_prep_hw_scan(local));
 409                 rc = drv_hw_scan(local, local->hw_scan_req);
 410         } else
 411                 rc = ieee80211_start_sw_scan(local);
 412
 413         mutex_lock(&local->scan_mtx);
 414
 415         if (rc) {
 416                 kfree(local->hw_scan_req);
 417                 local->hw_scan_req = NULL;
 418                 local->scanning = 0;
 419
 420                 ieee80211_recalc_idle(local);
 421
 422                 local->scan_req = NULL;
 423                 local->scan_sdata = NULL;
 424         }
 425
 426         return rc;
 427 }
 428
 429 static int ieee80211_scan_state_decision(struct ieee80211_local *local,
 430                                          unsigned long *next_delay)
 431 {
 432         bool associated = false;
 433         struct ieee80211_sub_if_data *sdata;
 434
 435         /* if no more bands/channels left, complete scan and advance to the idle state */
 436         if (local->scan_channel_idx >= local->scan_req->n_channels) {
 437                 ieee80211_scan_completed(&local->hw, false);
 438                 return 1;
 439         }
 440
 441         /* check if at least one STA interface is associated */
 442         mutex_lock(&local->iflist_mtx);
 443         list_for_each_entry(sdata, &local->interfaces, list) {
 444                 if (!ieee80211_sdata_running(sdata))
 445                         continue;
 446
 447                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 448                         if (sdata->u.mgd.associated) {
 449                                 associated = true;
 450                                 break;
 451                         }
 452                 }
 453         }
 454         mutex_unlock(&local->iflist_mtx);
 455
 456         if (local->scan_channel) {
 457                 /*
 458                  * we're currently scanning a different channel, let's
 459                  * switch back to the operating channel now if at least
 460                  * one interface is associated. Otherwise just scan the
 461                  * next channel
 462                  */
 463                 if (associated)
 464                         local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
 465                 else
 466                         local->next_scan_state = SCAN_SET_CHANNEL;
 467         } else {
 468                 /*
 469                  * we're on the operating channel currently, let's
 470                  * leave that channel now to scan another one
 471                  */
 472                 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
 473         }
 474
 475         *next_delay = 0;
 476         return 0;
 477 }
 478
 479 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
 480                                                     unsigned long *next_delay)
 481 {
 482         ieee80211_offchannel_stop_station(local);
 483
 484         __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
 485
 486         /*
 487          * What if the nullfunc frames didn't arrive?
 488          */
 489         drv_flush(local, false);
 490         if (local->ops->flush)
 491                 *next_delay = 0;
 492         else
 493                 *next_delay = HZ / 10;
 494
 495         /* advance to the next channel to be scanned */
 496         local->next_scan_state = SCAN_SET_CHANNEL;
 497 }
 498
 499 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
 500                                                     unsigned long *next_delay)
 501 {
 502         /* switch back to the operating channel */
 503         local->scan_channel = NULL;
 504         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 505
 506         /*
 507          * Only re-enable station mode interface now; beaconing will be
 508          * re-enabled once the full scan has been completed.
 509          */
 510         ieee80211_offchannel_return(local, false);
 511
 512         __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
 513
 514         *next_delay = HZ / 5;
 515         local->next_scan_state = SCAN_DECISION;
 516 }
 517
 518 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 519                                              unsigned long *next_delay)
 520 {
 521         int skip;
 522         struct ieee80211_channel *chan;
 523
 524         skip = 0;
 525         chan = local->scan_req->channels[local->scan_channel_idx];
 526
 527         local->scan_channel = chan;
 528         if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 529                 skip = 1;
 530
 531         /* advance state machine to next channel/band */
 532         local->scan_channel_idx++;
 533
 534         if (skip) {
 535                 /* if we skip this channel return to the decision state */
 536                 local->next_scan_state = SCAN_DECISION;
 537                 return;
 538         }
 539
 540         /*
 541          * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 542          * (which unfortunately doesn't say _why_ step a) is done,
 543          * but it waits for the probe delay or until a frame is
 544          * received - and the received frame would update the NAV).
 545          * For now, we do not support waiting until a frame is
 546          * received.
 547          *
 548          * In any case, it is not necessary for a passive scan.
 549          */
 550         if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
 551             !local->scan_req->n_ssids) {
 552                 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 553                 local->next_scan_state = SCAN_DECISION;
 554                 return;
 555         }
 556
 557         /* active scan, send probes */
 558         *next_delay = IEEE80211_PROBE_DELAY;
 559         local->next_scan_state = SCAN_SEND_PROBE;
 560 }
 561
 562 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 563                                             unsigned long *next_delay)
 564 {
 565         int i;
 566         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 567
 568         for (i = 0; i < local->scan_req->n_ssids; i++)
 569                 ieee80211_send_probe_req(
 570                         sdata, NULL,
 571                         local->scan_req->ssids[i].ssid,
 572                         local->scan_req->ssids[i].ssid_len,
 573                         local->scan_req->ie, local->scan_req->ie_len);
 574
 575         /*
 576          * After sending probe requests, wait for probe responses
 577          * on the channel.
 578          */
 579         *next_delay = IEEE80211_CHANNEL_TIME;
 580         local->next_scan_state = SCAN_DECISION;
 581 }
 582
 583 void ieee80211_scan_work(struct work_struct *work)
 584 {
 585         struct ieee80211_local *local =
 586                 container_of(work, struct ieee80211_local, scan_work.work);
 587         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 588         unsigned long next_delay = 0;
 589
 590         mutex_lock(&local->scan_mtx);
 591         if (!sdata || !local->scan_req) {
 592                 mutex_unlock(&local->scan_mtx);
 593                 return;
 594         }
 595
 596         if (local->hw_scan_req) {
 597                 int rc = drv_hw_scan(local, local->hw_scan_req);
 598                 mutex_unlock(&local->scan_mtx);
 599                 if (rc)
 600                         ieee80211_scan_completed(&local->hw, true);
 601                 return;
 602         }
 603
 604         if (local->scan_req && !local->scanning) {
 605                 struct cfg80211_scan_request *req = local->scan_req;
 606                 int rc;
 607
 608                 local->scan_req = NULL;
 609                 local->scan_sdata = NULL;
 610
 611                 rc = __ieee80211_start_scan(sdata, req);
 612                 mutex_unlock(&local->scan_mtx);
 613
 614                 if (rc)
 615                         ieee80211_scan_completed(&local->hw, true);
 616                 return;
 617         }
 618
 619         mutex_unlock(&local->scan_mtx);
 620
 621         /*
 622          * Avoid re-scheduling when the sdata is going away.
 623          */
 624         if (!ieee80211_sdata_running(sdata)) {
 625                 ieee80211_scan_completed(&local->hw, true);
 626                 return;
 627         }
 628
 629         /*
 630          * as long as no delay is required advance immediately
 631          * without scheduling a new work
 632          */
 633         do {
 634                 switch (local->next_scan_state) {
 635                 case SCAN_DECISION:
 636                         if (ieee80211_scan_state_decision(local, &next_delay))
 637                                 return;
 638                         break;
 639                 case SCAN_SET_CHANNEL:
 640                         ieee80211_scan_state_set_channel(local, &next_delay);
 641                         break;
 642                 case SCAN_SEND_PROBE:
 643                         ieee80211_scan_state_send_probe(local, &next_delay);
 644                         break;
 645                 case SCAN_LEAVE_OPER_CHANNEL:
 646                         ieee80211_scan_state_leave_oper_channel(local, &next_delay);
 647                         break;
 648                 case SCAN_ENTER_OPER_CHANNEL:
 649                         ieee80211_scan_state_enter_oper_channel(local, &next_delay);
 650                         break;
 651                 }
 652         } while (next_delay == 0);
 653
 654         ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
 655 }
 656
 657 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 658                            struct cfg80211_scan_request *req)
 659 {
 660         int res;
 661
 662         mutex_lock(&sdata->local->scan_mtx);
 663         res = __ieee80211_start_scan(sdata, req);
 664         mutex_unlock(&sdata->local->scan_mtx);
 665
 666         return res;
 667 }
 668
 669 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
 670                                     const u8 *ssid, u8 ssid_len)
 671 {
 672         struct ieee80211_local *local = sdata->local;
 673         int ret = -EBUSY;
 674
 675         mutex_lock(&local->scan_mtx);
 676
 677         /* busy scanning */
 678         if (local->scan_req)
 679                 goto unlock;
 680
 681         memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
 682         local->int_scan_req->ssids[0].ssid_len = ssid_len;
 683
 684         ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
 685  unlock:
 686         mutex_unlock(&local->scan_mtx);
 687         return ret;
 688 }
 689
 690 void ieee80211_scan_cancel(struct ieee80211_local *local)
 691 {
 692         bool abortscan;
 693
 694         cancel_delayed_work_sync(&local->scan_work);
 695
 696         /*
 697          * Only call this function when a scan can't be
 698          * queued -- mostly at suspend under RTNL.
 699          */
 700         mutex_lock(&local->scan_mtx);
 701         abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
 702                     (!local->scanning && local->scan_req);
 703         mutex_unlock(&local->scan_mtx);
 704
 705         if (abortscan)
 706                 ieee80211_scan_completed(&local->hw, true);
 707 }