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/pm_qos_params.h> 18 #include <net/sch_generic.h> 19 #include <linux/slab.h> 20 #include <net/mac80211.h> 21 22 #include "ieee80211_i.h" 23 #include "driver-ops.h" 24 #include "mesh.h" 25 26 #define IEEE80211_PROBE_DELAY (HZ / 33) 27 #define IEEE80211_CHANNEL_TIME (HZ / 33) 28 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) 29 30 struct ieee80211_bss * 31 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, 32 u8 *ssid, u8 ssid_len) 33 { 34 struct cfg80211_bss *cbss; 35 36 cbss = cfg80211_get_bss(local->hw.wiphy, 37 ieee80211_get_channel(local->hw.wiphy, freq), 38 bssid, ssid, ssid_len, 0, 0); 39 if (!cbss) 40 return NULL; 41 return (void *)cbss->priv; 42 } 43 44 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) 45 { 46 struct ieee80211_bss *bss = (void *)cbss->priv; 47 48 kfree(bss_mesh_id(bss)); 49 kfree(bss_mesh_cfg(bss)); 50 } 51 52 void ieee80211_rx_bss_put(struct ieee80211_local *local, 53 struct ieee80211_bss *bss) 54 { 55 if (!bss) 56 return; 57 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); 58 } 59 60 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 61 { 62 u8 qos_info; 63 64 if (elems->wmm_info && elems->wmm_info_len == 7 65 && elems->wmm_info[5] == 1) 66 qos_info = elems->wmm_info[6]; 67 else if (elems->wmm_param && elems->wmm_param_len == 24 68 && elems->wmm_param[5] == 1) 69 qos_info = elems->wmm_param[6]; 70 else 71 /* no valid wmm information or parameter element found */ 72 return false; 73 74 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 75 } 76 77 struct ieee80211_bss * 78 ieee80211_bss_info_update(struct ieee80211_local *local, 79 struct ieee80211_rx_status *rx_status, 80 struct ieee80211_mgmt *mgmt, 81 size_t len, 82 struct ieee802_11_elems *elems, 83 struct ieee80211_channel *channel, 84 bool beacon) 85 { 86 struct cfg80211_bss *cbss; 87 struct ieee80211_bss *bss; 88 int clen, srlen; 89 s32 signal = 0; 90 91 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 92 signal = rx_status->signal * 100; 93 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 94 signal = (rx_status->signal * 100) / local->hw.max_signal; 95 96 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, 97 mgmt, len, signal, GFP_ATOMIC); 98 99 if (!cbss) 100 return NULL; 101 102 cbss->free_priv = ieee80211_rx_bss_free; 103 bss = (void *)cbss->priv; 104 105 /* save the ERP value so that it is available at association time */ 106 if (elems->erp_info && elems->erp_info_len >= 1) { 107 bss->erp_value = elems->erp_info[0]; 108 bss->has_erp_value = 1; 109 } 110 111 if (elems->tim) { 112 struct ieee80211_tim_ie *tim_ie = 113 (struct ieee80211_tim_ie *)elems->tim; 114 bss->dtim_period = tim_ie->dtim_period; 115 } 116 117 /* replace old supported rates if we get new values */ 118 srlen = 0; 119 if (elems->supp_rates) { 120 clen = IEEE80211_MAX_SUPP_RATES; 121 if (clen > elems->supp_rates_len) 122 clen = elems->supp_rates_len; 123 memcpy(bss->supp_rates, elems->supp_rates, clen); 124 srlen += clen; 125 } 126 if (elems->ext_supp_rates) { 127 clen = IEEE80211_MAX_SUPP_RATES - srlen; 128 if (clen > elems->ext_supp_rates_len) 129 clen = elems->ext_supp_rates_len; 130 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); 131 srlen += clen; 132 } 133 if (srlen) 134 bss->supp_rates_len = srlen; 135 136 bss->wmm_used = elems->wmm_param || elems->wmm_info; 137 bss->uapsd_supported = is_uapsd_supported(elems); 138 139 if (!beacon) 140 bss->last_probe_resp = jiffies; 141 142 return bss; 143 } 144 145 ieee80211_rx_result 146 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 147 { 148 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 149 struct ieee80211_mgmt *mgmt; 150 struct ieee80211_bss *bss; 151 u8 *elements; 152 struct ieee80211_channel *channel; 153 size_t baselen; 154 int freq; 155 __le16 fc; 156 bool presp, beacon = false; 157 struct ieee802_11_elems elems; 158 159 if (skb->len < 2) 160 return RX_DROP_UNUSABLE; 161 162 mgmt = (struct ieee80211_mgmt *) skb->data; 163 fc = mgmt->frame_control; 164 165 if (ieee80211_is_ctl(fc)) 166 return RX_CONTINUE; 167 168 if (skb->len < 24) 169 return RX_DROP_MONITOR; 170 171 presp = ieee80211_is_probe_resp(fc); 172 if (presp) { 173 /* ignore ProbeResp to foreign address */ 174 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 175 return RX_DROP_MONITOR; 176 177 presp = true; 178 elements = mgmt->u.probe_resp.variable; 179 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 180 } else { 181 beacon = ieee80211_is_beacon(fc); 182 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 183 elements = mgmt->u.beacon.variable; 184 } 185 186 if (!presp && !beacon) 187 return RX_CONTINUE; 188 189 if (baselen > skb->len) 190 return RX_DROP_MONITOR; 191 192 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 193 194 if (elems.ds_params && elems.ds_params_len == 1) 195 freq = ieee80211_channel_to_frequency(elems.ds_params[0]); 196 else 197 freq = rx_status->freq; 198 199 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 200 201 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 202 return RX_DROP_MONITOR; 203 204 bss = ieee80211_bss_info_update(sdata->local, rx_status, 205 mgmt, skb->len, &elems, 206 channel, beacon); 207 if (bss) 208 ieee80211_rx_bss_put(sdata->local, bss); 209 210 dev_kfree_skb(skb); 211 return RX_QUEUED; 212 } 213 214 /* return false if no more work */ 215 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 216 { 217 struct cfg80211_scan_request *req = local->scan_req; 218 enum ieee80211_band band; 219 int i, ielen, n_chans; 220 221 do { 222 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 223 return false; 224 225 band = local->hw_scan_band; 226 n_chans = 0; 227 for (i = 0; i < req->n_channels; i++) { 228 if (req->channels[i]->band == band) { 229 local->hw_scan_req->channels[n_chans] = 230 req->channels[i]; 231 n_chans++; 232 } 233 } 234 235 local->hw_scan_band++; 236 } while (!n_chans); 237 238 local->hw_scan_req->n_channels = n_chans; 239 240 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 241 req->ie, req->ie_len, band); 242 local->hw_scan_req->ie_len = ielen; 243 244 return true; 245 } 246 247 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 248 { 249 struct ieee80211_local *local = hw_to_local(hw); 250 bool was_hw_scan; 251 252 trace_api_scan_completed(local, aborted); 253 254 mutex_lock(&local->scan_mtx); 255 256 /* 257 * It's ok to abort a not-yet-running scan (that 258 * we have one at all will be verified by checking 259 * local->scan_req next), but not to complete it 260 * successfully. 261 */ 262 if (WARN_ON(!local->scanning && !aborted)) 263 aborted = true; 264 265 if (WARN_ON(!local->scan_req)) { 266 mutex_unlock(&local->scan_mtx); 267 return; 268 } 269 270 was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 271 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 272 ieee80211_queue_delayed_work(&local->hw, 273 &local->scan_work, 0); 274 mutex_unlock(&local->scan_mtx); 275 return; 276 } 277 278 kfree(local->hw_scan_req); 279 local->hw_scan_req = NULL; 280 281 if (local->scan_req != local->int_scan_req) 282 cfg80211_scan_done(local->scan_req, aborted); 283 local->scan_req = NULL; 284 local->scan_sdata = NULL; 285 286 local->scanning = 0; 287 local->scan_channel = NULL; 288 289 /* we only have to protect scan_req and hw/sw scan */ 290 mutex_unlock(&local->scan_mtx); 291 292 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 293 if (was_hw_scan) 294 goto done; 295 296 ieee80211_configure_filter(local); 297 298 drv_sw_scan_complete(local); 299 300 ieee80211_offchannel_return(local, true); 301 302 done: 303 ieee80211_recalc_idle(local); 304 ieee80211_mlme_notify_scan_completed(local); 305 ieee80211_ibss_notify_scan_completed(local); 306 ieee80211_mesh_notify_scan_completed(local); 307 ieee80211_queue_work(&local->hw, &local->work_work); 308 } 309 EXPORT_SYMBOL(ieee80211_scan_completed); 310 311 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 312 { 313 /* 314 * Hardware/driver doesn't support hw_scan, so use software 315 * scanning instead. First send a nullfunc frame with power save 316 * bit on so that AP will buffer the frames for us while we are not 317 * listening, then send probe requests to each channel and wait for 318 * the responses. After all channels are scanned, tune back to the 319 * original channel and send a nullfunc frame with power save bit 320 * off to trigger the AP to send us all the buffered frames. 321 * 322 * Note that while local->sw_scanning is true everything else but 323 * nullfunc frames and probe requests will be dropped in 324 * ieee80211_tx_h_check_assoc(). 325 */ 326 drv_sw_scan_start(local); 327 328 ieee80211_offchannel_stop_beaconing(local); 329 330 local->leave_oper_channel_time = 0; 331 local->next_scan_state = SCAN_DECISION; 332 local->scan_channel_idx = 0; 333 334 drv_flush(local, false); 335 336 ieee80211_configure_filter(local); 337 338 ieee80211_queue_delayed_work(&local->hw, 339 &local->scan_work, 340 IEEE80211_CHANNEL_TIME); 341 342 return 0; 343 } 344 345 346 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 347 struct cfg80211_scan_request *req) 348 { 349 struct ieee80211_local *local = sdata->local; 350 int rc; 351 352 if (local->scan_req) 353 return -EBUSY; 354 355 if (!list_empty(&local->work_list)) { 356 /* wait for the work to finish/time out */ 357 local->scan_req = req; 358 local->scan_sdata = sdata; 359 return 0; 360 } 361 362 if (local->ops->hw_scan) { 363 u8 *ies; 364 365 local->hw_scan_req = kmalloc( 366 sizeof(*local->hw_scan_req) + 367 req->n_channels * sizeof(req->channels[0]) + 368 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 369 req->ie_len, GFP_KERNEL); 370 if (!local->hw_scan_req) 371 return -ENOMEM; 372 373 local->hw_scan_req->ssids = req->ssids; 374 local->hw_scan_req->n_ssids = req->n_ssids; 375 ies = (u8 *)local->hw_scan_req + 376 sizeof(*local->hw_scan_req) + 377 req->n_channels * sizeof(req->channels[0]); 378 local->hw_scan_req->ie = ies; 379 380 local->hw_scan_band = 0; 381 382 /* 383 * After allocating local->hw_scan_req, we must 384 * go through until ieee80211_prep_hw_scan(), so 385 * anything that might be changed here and leave 386 * this function early must not go after this 387 * allocation. 388 */ 389 } 390 391 local->scan_req = req; 392 local->scan_sdata = sdata; 393 394 if (local->ops->hw_scan) 395 __set_bit(SCAN_HW_SCANNING, &local->scanning); 396 else 397 __set_bit(SCAN_SW_SCANNING, &local->scanning); 398 399 /* 400 * Kicking off the scan need not be protected, 401 * only the scan variable stuff, since now 402 * local->scan_req is assigned and other callers 403 * will abort their scan attempts. 404 * 405 * This avoids too many locking dependencies 406 * so that the scan completed calls have more 407 * locking freedom. 408 */ 409 410 ieee80211_recalc_idle(local); 411 mutex_unlock(&local->scan_mtx); 412 413 if (local->ops->hw_scan) { 414 WARN_ON(!ieee80211_prep_hw_scan(local)); 415 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 416 } else 417 rc = ieee80211_start_sw_scan(local); 418 419 mutex_lock(&local->scan_mtx); 420 421 if (rc) { 422 kfree(local->hw_scan_req); 423 local->hw_scan_req = NULL; 424 local->scanning = 0; 425 426 ieee80211_recalc_idle(local); 427 428 local->scan_req = NULL; 429 local->scan_sdata = NULL; 430 } 431 432 return rc; 433 } 434 435 static unsigned long 436 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 437 { 438 /* 439 * TODO: channel switching also consumes quite some time, 440 * add that delay as well to get a better estimation 441 */ 442 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 443 return IEEE80211_PASSIVE_CHANNEL_TIME; 444 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 445 } 446 447 static int ieee80211_scan_state_decision(struct ieee80211_local *local, 448 unsigned long *next_delay) 449 { 450 bool associated = false; 451 bool tx_empty = true; 452 bool bad_latency; 453 bool listen_int_exceeded; 454 unsigned long min_beacon_int = 0; 455 struct ieee80211_sub_if_data *sdata; 456 struct ieee80211_channel *next_chan; 457 458 /* if no more bands/channels left, complete scan and advance to the idle state */ 459 if (local->scan_channel_idx >= local->scan_req->n_channels) { 460 ieee80211_scan_completed(&local->hw, false); 461 return 1; 462 } 463 464 /* 465 * check if at least one STA interface is associated, 466 * check if at least one STA interface has pending tx frames 467 * and grab the lowest used beacon interval 468 */ 469 mutex_lock(&local->iflist_mtx); 470 list_for_each_entry(sdata, &local->interfaces, list) { 471 if (!ieee80211_sdata_running(sdata)) 472 continue; 473 474 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 475 if (sdata->u.mgd.associated) { 476 associated = true; 477 478 if (sdata->vif.bss_conf.beacon_int < 479 min_beacon_int || min_beacon_int == 0) 480 min_beacon_int = 481 sdata->vif.bss_conf.beacon_int; 482 483 if (!qdisc_all_tx_empty(sdata->dev)) { 484 tx_empty = false; 485 break; 486 } 487 } 488 } 489 } 490 mutex_unlock(&local->iflist_mtx); 491 492 if (local->scan_channel) { 493 /* 494 * we're currently scanning a different channel, let's 495 * see if we can scan another channel without interfering 496 * with the current traffic situation. 497 * 498 * Since we don't know if the AP has pending frames for us 499 * we can only check for our tx queues and use the current 500 * pm_qos requirements for rx. Hence, if no tx traffic occurs 501 * at all we will scan as many channels in a row as the pm_qos 502 * latency allows us to. Additionally we also check for the 503 * currently negotiated listen interval to prevent losing 504 * frames unnecessarily. 505 * 506 * Otherwise switch back to the operating channel. 507 */ 508 next_chan = local->scan_req->channels[local->scan_channel_idx]; 509 510 bad_latency = time_after(jiffies + 511 ieee80211_scan_get_channel_time(next_chan), 512 local->leave_oper_channel_time + 513 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 514 515 listen_int_exceeded = time_after(jiffies + 516 ieee80211_scan_get_channel_time(next_chan), 517 local->leave_oper_channel_time + 518 usecs_to_jiffies(min_beacon_int * 1024) * 519 local->hw.conf.listen_interval); 520 521 if (associated && ( !tx_empty || bad_latency || 522 listen_int_exceeded)) 523 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 524 else 525 local->next_scan_state = SCAN_SET_CHANNEL; 526 } else { 527 /* 528 * we're on the operating channel currently, let's 529 * leave that channel now to scan another one 530 */ 531 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 532 } 533 534 *next_delay = 0; 535 return 0; 536 } 537 538 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 539 unsigned long *next_delay) 540 { 541 ieee80211_offchannel_stop_station(local); 542 543 __set_bit(SCAN_OFF_CHANNEL, &local->scanning); 544 545 /* 546 * What if the nullfunc frames didn't arrive? 547 */ 548 drv_flush(local, false); 549 if (local->ops->flush) 550 *next_delay = 0; 551 else 552 *next_delay = HZ / 10; 553 554 /* remember when we left the operating channel */ 555 local->leave_oper_channel_time = jiffies; 556 557 /* advance to the next channel to be scanned */ 558 local->next_scan_state = SCAN_SET_CHANNEL; 559 } 560 561 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 562 unsigned long *next_delay) 563 { 564 /* switch back to the operating channel */ 565 local->scan_channel = NULL; 566 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 567 568 /* 569 * Only re-enable station mode interface now; beaconing will be 570 * re-enabled once the full scan has been completed. 571 */ 572 ieee80211_offchannel_return(local, false); 573 574 __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); 575 576 *next_delay = HZ / 5; 577 local->next_scan_state = SCAN_DECISION; 578 } 579 580 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 581 unsigned long *next_delay) 582 { 583 int skip; 584 struct ieee80211_channel *chan; 585 586 skip = 0; 587 chan = local->scan_req->channels[local->scan_channel_idx]; 588 589 local->scan_channel = chan; 590 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 591 skip = 1; 592 593 /* advance state machine to next channel/band */ 594 local->scan_channel_idx++; 595 596 if (skip) { 597 /* if we skip this channel return to the decision state */ 598 local->next_scan_state = SCAN_DECISION; 599 return; 600 } 601 602 /* 603 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 604 * (which unfortunately doesn't say _why_ step a) is done, 605 * but it waits for the probe delay or until a frame is 606 * received - and the received frame would update the NAV). 607 * For now, we do not support waiting until a frame is 608 * received. 609 * 610 * In any case, it is not necessary for a passive scan. 611 */ 612 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 613 !local->scan_req->n_ssids) { 614 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 615 local->next_scan_state = SCAN_DECISION; 616 return; 617 } 618 619 /* active scan, send probes */ 620 *next_delay = IEEE80211_PROBE_DELAY; 621 local->next_scan_state = SCAN_SEND_PROBE; 622 } 623 624 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 625 unsigned long *next_delay) 626 { 627 int i; 628 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 629 630 for (i = 0; i < local->scan_req->n_ssids; i++) 631 ieee80211_send_probe_req( 632 sdata, NULL, 633 local->scan_req->ssids[i].ssid, 634 local->scan_req->ssids[i].ssid_len, 635 local->scan_req->ie, local->scan_req->ie_len); 636 637 /* 638 * After sending probe requests, wait for probe responses 639 * on the channel. 640 */ 641 *next_delay = IEEE80211_CHANNEL_TIME; 642 local->next_scan_state = SCAN_DECISION; 643 } 644 645 void ieee80211_scan_work(struct work_struct *work) 646 { 647 struct ieee80211_local *local = 648 container_of(work, struct ieee80211_local, scan_work.work); 649 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 650 unsigned long next_delay = 0; 651 652 mutex_lock(&local->scan_mtx); 653 if (!sdata || !local->scan_req) { 654 mutex_unlock(&local->scan_mtx); 655 return; 656 } 657 658 if (local->hw_scan_req) { 659 int rc = drv_hw_scan(local, sdata, local->hw_scan_req); 660 mutex_unlock(&local->scan_mtx); 661 if (rc) 662 ieee80211_scan_completed(&local->hw, true); 663 return; 664 } 665 666 if (local->scan_req && !local->scanning) { 667 struct cfg80211_scan_request *req = local->scan_req; 668 int rc; 669 670 local->scan_req = NULL; 671 local->scan_sdata = NULL; 672 673 rc = __ieee80211_start_scan(sdata, req); 674 mutex_unlock(&local->scan_mtx); 675 676 if (rc) 677 ieee80211_scan_completed(&local->hw, true); 678 return; 679 } 680 681 mutex_unlock(&local->scan_mtx); 682 683 /* 684 * Avoid re-scheduling when the sdata is going away. 685 */ 686 if (!ieee80211_sdata_running(sdata)) { 687 ieee80211_scan_completed(&local->hw, true); 688 return; 689 } 690 691 /* 692 * as long as no delay is required advance immediately 693 * without scheduling a new work 694 */ 695 do { 696 switch (local->next_scan_state) { 697 case SCAN_DECISION: 698 if (ieee80211_scan_state_decision(local, &next_delay)) 699 return; 700 break; 701 case SCAN_SET_CHANNEL: 702 ieee80211_scan_state_set_channel(local, &next_delay); 703 break; 704 case SCAN_SEND_PROBE: 705 ieee80211_scan_state_send_probe(local, &next_delay); 706 break; 707 case SCAN_LEAVE_OPER_CHANNEL: 708 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 709 break; 710 case SCAN_ENTER_OPER_CHANNEL: 711 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 712 break; 713 } 714 } while (next_delay == 0); 715 716 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 717 } 718 719 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 720 struct cfg80211_scan_request *req) 721 { 722 int res; 723 724 mutex_lock(&sdata->local->scan_mtx); 725 res = __ieee80211_start_scan(sdata, req); 726 mutex_unlock(&sdata->local->scan_mtx); 727 728 return res; 729 } 730 731 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 732 const u8 *ssid, u8 ssid_len, 733 struct ieee80211_channel *chan) 734 { 735 struct ieee80211_local *local = sdata->local; 736 int ret = -EBUSY; 737 enum nl80211_band band; 738 739 mutex_lock(&local->scan_mtx); 740 741 /* busy scanning */ 742 if (local->scan_req) 743 goto unlock; 744 745 /* fill internal scan request */ 746 if (!chan) { 747 int i, nchan = 0; 748 749 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 750 if (!local->hw.wiphy->bands[band]) 751 continue; 752 for (i = 0; 753 i < local->hw.wiphy->bands[band]->n_channels; 754 i++) { 755 local->int_scan_req->channels[nchan] = 756 &local->hw.wiphy->bands[band]->channels[i]; 757 nchan++; 758 } 759 } 760 761 local->int_scan_req->n_channels = nchan; 762 } else { 763 local->int_scan_req->channels[0] = chan; 764 local->int_scan_req->n_channels = 1; 765 } 766 767 local->int_scan_req->ssids = &local->scan_ssid; 768 local->int_scan_req->n_ssids = 1; 769 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 770 local->int_scan_req->ssids[0].ssid_len = ssid_len; 771 772 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 773 unlock: 774 mutex_unlock(&local->scan_mtx); 775 return ret; 776 } 777 778 void ieee80211_scan_cancel(struct ieee80211_local *local) 779 { 780 bool abortscan; 781 782 cancel_delayed_work_sync(&local->scan_work); 783 784 /* 785 * Only call this function when a scan can't be 786 * queued -- mostly at suspend under RTNL. 787 */ 788 mutex_lock(&local->scan_mtx); 789 abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || 790 (!local->scanning && local->scan_req); 791 mutex_unlock(&local->scan_mtx); 792 793 if (abortscan) 794 ieee80211_scan_completed(&local->hw, true); 795 } 796