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 30struct ieee80211_bss * 31ieee80211_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 44static 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 52void 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 60static 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 77struct ieee80211_bss * 78ieee80211_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 /* If the beacon had no TIM IE, or it was invalid, use 1 */ 118 if (beacon && !bss->dtim_period) 119 bss->dtim_period = 1; 120 121 /* replace old supported rates if we get new values */ 122 srlen = 0; 123 if (elems->supp_rates) { 124 clen = IEEE80211_MAX_SUPP_RATES; 125 if (clen > elems->supp_rates_len) 126 clen = elems->supp_rates_len; 127 memcpy(bss->supp_rates, elems->supp_rates, clen); 128 srlen += clen; 129 } 130 if (elems->ext_supp_rates) { 131 clen = IEEE80211_MAX_SUPP_RATES - srlen; 132 if (clen > elems->ext_supp_rates_len) 133 clen = elems->ext_supp_rates_len; 134 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); 135 srlen += clen; 136 } 137 if (srlen) 138 bss->supp_rates_len = srlen; 139 140 bss->wmm_used = elems->wmm_param || elems->wmm_info; 141 bss->uapsd_supported = is_uapsd_supported(elems); 142 143 if (!beacon) 144 bss->last_probe_resp = jiffies; 145 146 return bss; 147} 148 149ieee80211_rx_result 150ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 151{ 152 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 153 struct ieee80211_mgmt *mgmt; 154 struct ieee80211_bss *bss; 155 u8 *elements; 156 struct ieee80211_channel *channel; 157 size_t baselen; 158 int freq; 159 __le16 fc; 160 bool presp, beacon = false; 161 struct ieee802_11_elems elems; 162 163 if (skb->len < 2) 164 return RX_DROP_UNUSABLE; 165 166 mgmt = (struct ieee80211_mgmt *) skb->data; 167 fc = mgmt->frame_control; 168 169 if (ieee80211_is_ctl(fc)) 170 return RX_CONTINUE; 171 172 if (skb->len < 24) 173 return RX_DROP_MONITOR; 174 175 presp = ieee80211_is_probe_resp(fc); 176 if (presp) { 177 /* ignore ProbeResp to foreign address */ 178 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 179 return RX_DROP_MONITOR; 180 181 presp = true; 182 elements = mgmt->u.probe_resp.variable; 183 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 184 } else { 185 beacon = ieee80211_is_beacon(fc); 186 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 187 elements = mgmt->u.beacon.variable; 188 } 189 190 if (!presp && !beacon) 191 return RX_CONTINUE; 192 193 if (baselen > skb->len) 194 return RX_DROP_MONITOR; 195 196 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 197 198 if (elems.ds_params && elems.ds_params_len == 1) 199 freq = ieee80211_channel_to_frequency(elems.ds_params[0]); 200 else 201 freq = rx_status->freq; 202 203 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 204 205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 206 return RX_DROP_MONITOR; 207 208 bss = ieee80211_bss_info_update(sdata->local, rx_status, 209 mgmt, skb->len, &elems, 210 channel, beacon); 211 if (bss) 212 ieee80211_rx_bss_put(sdata->local, bss); 213 214 dev_kfree_skb(skb); 215 return RX_QUEUED; 216} 217 218/* return false if no more work */ 219static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 220{ 221 struct cfg80211_scan_request *req = local->scan_req; 222 enum ieee80211_band band; 223 int i, ielen, n_chans; 224 225 do { 226 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 227 return false; 228 229 band = local->hw_scan_band; 230 n_chans = 0; 231 for (i = 0; i < req->n_channels; i++) { 232 if (req->channels[i]->band == band) { 233 local->hw_scan_req->channels[n_chans] = 234 req->channels[i]; 235 n_chans++; 236 } 237 } 238 239 local->hw_scan_band++; 240 } while (!n_chans); 241 242 local->hw_scan_req->n_channels = n_chans; 243 244 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 245 req->ie, req->ie_len, band); 246 local->hw_scan_req->ie_len = ielen; 247 248 return true; 249} 250 251void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 252{ 253 struct ieee80211_local *local = hw_to_local(hw); 254 bool was_hw_scan; 255 256 trace_api_scan_completed(local, aborted); 257 258 mutex_lock(&local->scan_mtx); 259 260 /* 261 * It's ok to abort a not-yet-running scan (that 262 * we have one at all will be verified by checking 263 * local->scan_req next), but not to complete it 264 * successfully. 265 */ 266 if (WARN_ON(!local->scanning && !aborted)) 267 aborted = true; 268 269 if (WARN_ON(!local->scan_req)) { 270 mutex_unlock(&local->scan_mtx); 271 return; 272 } 273 274 was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 275 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 276 ieee80211_queue_delayed_work(&local->hw, 277 &local->scan_work, 0); 278 mutex_unlock(&local->scan_mtx); 279 return; 280 } 281 282 kfree(local->hw_scan_req); 283 local->hw_scan_req = NULL; 284 285 if (local->scan_req != local->int_scan_req) 286 cfg80211_scan_done(local->scan_req, aborted); 287 local->scan_req = NULL; 288 local->scan_sdata = NULL; 289 290 local->scanning = 0; 291 local->scan_channel = NULL; 292 293 /* we only have to protect scan_req and hw/sw scan */ 294 mutex_unlock(&local->scan_mtx); 295 296 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 297 if (was_hw_scan) 298 goto done; 299 300 ieee80211_configure_filter(local); 301 302 drv_sw_scan_complete(local); 303 304 ieee80211_offchannel_return(local, true); 305 306 done: 307 ieee80211_recalc_idle(local); 308 ieee80211_mlme_notify_scan_completed(local); 309 ieee80211_ibss_notify_scan_completed(local); 310 ieee80211_mesh_notify_scan_completed(local); 311 ieee80211_queue_work(&local->hw, &local->work_work); 312} 313EXPORT_SYMBOL(ieee80211_scan_completed); 314 315static int ieee80211_start_sw_scan(struct ieee80211_local *local) 316{ 317 /* 318 * Hardware/driver doesn't support hw_scan, so use software 319 * scanning instead. First send a nullfunc frame with power save 320 * bit on so that AP will buffer the frames for us while we are not 321 * listening, then send probe requests to each channel and wait for 322 * the responses. After all channels are scanned, tune back to the 323 * original channel and send a nullfunc frame with power save bit 324 * off to trigger the AP to send us all the buffered frames. 325 * 326 * Note that while local->sw_scanning is true everything else but 327 * nullfunc frames and probe requests will be dropped in 328 * ieee80211_tx_h_check_assoc(). 329 */ 330 drv_sw_scan_start(local); 331 332 ieee80211_offchannel_stop_beaconing(local); 333 334 local->leave_oper_channel_time = 0; 335 local->next_scan_state = SCAN_DECISION; 336 local->scan_channel_idx = 0; 337 338 drv_flush(local, false); 339 340 ieee80211_configure_filter(local); 341 342 ieee80211_queue_delayed_work(&local->hw, 343 &local->scan_work, 344 IEEE80211_CHANNEL_TIME); 345 346 return 0; 347} 348 349 350static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 351 struct cfg80211_scan_request *req) 352{ 353 struct ieee80211_local *local = sdata->local; 354 int rc; 355 356 if (local->scan_req) 357 return -EBUSY; 358 359 if (!list_empty(&local->work_list)) { 360 /* wait for the work to finish/time out */ 361 local->scan_req = req; 362 local->scan_sdata = sdata; 363 return 0; 364 } 365 366 if (local->ops->hw_scan) { 367 u8 *ies; 368 369 local->hw_scan_req = kmalloc( 370 sizeof(*local->hw_scan_req) + 371 req->n_channels * sizeof(req->channels[0]) + 372 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 373 req->ie_len, GFP_KERNEL); 374 if (!local->hw_scan_req) 375 return -ENOMEM; 376 377 local->hw_scan_req->ssids = req->ssids; 378 local->hw_scan_req->n_ssids = req->n_ssids; 379 ies = (u8 *)local->hw_scan_req + 380 sizeof(*local->hw_scan_req) + 381 req->n_channels * sizeof(req->channels[0]); 382 local->hw_scan_req->ie = ies; 383 384 local->hw_scan_band = 0; 385 386 /* 387 * After allocating local->hw_scan_req, we must 388 * go through until ieee80211_prep_hw_scan(), so 389 * anything that might be changed here and leave 390 * this function early must not go after this 391 * allocation. 392 */ 393 } 394 395 local->scan_req = req; 396 local->scan_sdata = sdata; 397 398 if (local->ops->hw_scan) 399 __set_bit(SCAN_HW_SCANNING, &local->scanning); 400 else 401 __set_bit(SCAN_SW_SCANNING, &local->scanning); 402 403 ieee80211_recalc_idle(local); 404 405 if (local->ops->hw_scan) { 406 WARN_ON(!ieee80211_prep_hw_scan(local)); 407 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 408 } else 409 rc = ieee80211_start_sw_scan(local); 410 411 if (rc) { 412 kfree(local->hw_scan_req); 413 local->hw_scan_req = NULL; 414 local->scanning = 0; 415 416 ieee80211_recalc_idle(local); 417 418 local->scan_req = NULL; 419 local->scan_sdata = NULL; 420 } 421 422 return rc; 423} 424 425static unsigned long 426ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 427{ 428 /* 429 * TODO: channel switching also consumes quite some time, 430 * add that delay as well to get a better estimation 431 */ 432 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 433 return IEEE80211_PASSIVE_CHANNEL_TIME; 434 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 435} 436 437static int ieee80211_scan_state_decision(struct ieee80211_local *local, 438 unsigned long *next_delay) 439{ 440 bool associated = false; 441 bool tx_empty = true; 442 bool bad_latency; 443 bool listen_int_exceeded; 444 unsigned long min_beacon_int = 0; 445 struct ieee80211_sub_if_data *sdata; 446 struct ieee80211_channel *next_chan; 447 448 /* if no more bands/channels left, complete scan and advance to the idle state */ 449 if (local->scan_channel_idx >= local->scan_req->n_channels) { 450 ieee80211_scan_completed(&local->hw, false); 451 return 1; 452 } 453 454 /* 455 * check if at least one STA interface is associated, 456 * check if at least one STA interface has pending tx frames 457 * and grab the lowest used beacon interval 458 */ 459 mutex_lock(&local->iflist_mtx); 460 list_for_each_entry(sdata, &local->interfaces, list) { 461 if (!ieee80211_sdata_running(sdata)) 462 continue; 463 464 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 465 if (sdata->u.mgd.associated) { 466 associated = true; 467 468 if (sdata->vif.bss_conf.beacon_int < 469 min_beacon_int || min_beacon_int == 0) 470 min_beacon_int = 471 sdata->vif.bss_conf.beacon_int; 472 473 if (!qdisc_all_tx_empty(sdata->dev)) { 474 tx_empty = false; 475 break; 476 } 477 } 478 } 479 } 480 mutex_unlock(&local->iflist_mtx); 481 482 if (local->scan_channel) { 483 /* 484 * we're currently scanning a different channel, let's 485 * see if we can scan another channel without interfering 486 * with the current traffic situation. 487 * 488 * Since we don't know if the AP has pending frames for us 489 * we can only check for our tx queues and use the current 490 * pm_qos requirements for rx. Hence, if no tx traffic occurs 491 * at all we will scan as many channels in a row as the pm_qos 492 * latency allows us to. Additionally we also check for the 493 * currently negotiated listen interval to prevent losing 494 * frames unnecessarily. 495 * 496 * Otherwise switch back to the operating channel. 497 */ 498 next_chan = local->scan_req->channels[local->scan_channel_idx]; 499 500 bad_latency = time_after(jiffies + 501 ieee80211_scan_get_channel_time(next_chan), 502 local->leave_oper_channel_time + 503 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 504 505 listen_int_exceeded = time_after(jiffies + 506 ieee80211_scan_get_channel_time(next_chan), 507 local->leave_oper_channel_time + 508 usecs_to_jiffies(min_beacon_int * 1024) * 509 local->hw.conf.listen_interval); 510 511 if (associated && ( !tx_empty || bad_latency || 512 listen_int_exceeded)) 513 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 514 else 515 local->next_scan_state = SCAN_SET_CHANNEL; 516 } else { 517 /* 518 * we're on the operating channel currently, let's 519 * leave that channel now to scan another one 520 */ 521 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 522 } 523 524 *next_delay = 0; 525 return 0; 526} 527 528static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 529 unsigned long *next_delay) 530{ 531 ieee80211_offchannel_stop_station(local); 532 533 __set_bit(SCAN_OFF_CHANNEL, &local->scanning); 534 535 /* 536 * What if the nullfunc frames didn't arrive? 537 */ 538 drv_flush(local, false); 539 if (local->ops->flush) 540 *next_delay = 0; 541 else 542 *next_delay = HZ / 10; 543 544 /* remember when we left the operating channel */ 545 local->leave_oper_channel_time = jiffies; 546 547 /* advance to the next channel to be scanned */ 548 local->next_scan_state = SCAN_SET_CHANNEL; 549} 550 551static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 552 unsigned long *next_delay) 553{ 554 /* switch back to the operating channel */ 555 local->scan_channel = NULL; 556 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 557 558 /* 559 * Only re-enable station mode interface now; beaconing will be 560 * re-enabled once the full scan has been completed. 561 */ 562 ieee80211_offchannel_return(local, false); 563 564 __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); 565 566 *next_delay = HZ / 5; 567 local->next_scan_state = SCAN_DECISION; 568} 569 570static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 571 unsigned long *next_delay) 572{ 573 int skip; 574 struct ieee80211_channel *chan; 575 576 skip = 0; 577 chan = local->scan_req->channels[local->scan_channel_idx]; 578 579 local->scan_channel = chan; 580 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 581 skip = 1; 582 583 /* advance state machine to next channel/band */ 584 local->scan_channel_idx++; 585 586 if (skip) { 587 /* if we skip this channel return to the decision state */ 588 local->next_scan_state = SCAN_DECISION; 589 return; 590 } 591 592 /* 593 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 594 * (which unfortunately doesn't say _why_ step a) is done, 595 * but it waits for the probe delay or until a frame is 596 * received - and the received frame would update the NAV). 597 * For now, we do not support waiting until a frame is 598 * received. 599 * 600 * In any case, it is not necessary for a passive scan. 601 */ 602 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 603 !local->scan_req->n_ssids) { 604 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 605 local->next_scan_state = SCAN_DECISION; 606 return; 607 } 608 609 /* active scan, send probes */ 610 *next_delay = IEEE80211_PROBE_DELAY; 611 local->next_scan_state = SCAN_SEND_PROBE; 612} 613 614static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 615 unsigned long *next_delay) 616{ 617 int i; 618 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 619 620 for (i = 0; i < local->scan_req->n_ssids; i++) 621 ieee80211_send_probe_req( 622 sdata, NULL, 623 local->scan_req->ssids[i].ssid, 624 local->scan_req->ssids[i].ssid_len, 625 local->scan_req->ie, local->scan_req->ie_len); 626 627 /* 628 * After sending probe requests, wait for probe responses 629 * on the channel. 630 */ 631 *next_delay = IEEE80211_CHANNEL_TIME; 632 local->next_scan_state = SCAN_DECISION; 633} 634 635void ieee80211_scan_work(struct work_struct *work) 636{ 637 struct ieee80211_local *local = 638 container_of(work, struct ieee80211_local, scan_work.work); 639 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 640 unsigned long next_delay = 0; 641 642 mutex_lock(&local->scan_mtx); 643 if (!sdata || !local->scan_req) { 644 mutex_unlock(&local->scan_mtx); 645 return; 646 } 647 648 if (local->hw_scan_req) { 649 int rc = drv_hw_scan(local, sdata, local->hw_scan_req); 650 mutex_unlock(&local->scan_mtx); 651 if (rc) 652 ieee80211_scan_completed(&local->hw, true); 653 return; 654 } 655 656 if (local->scan_req && !local->scanning) { 657 struct cfg80211_scan_request *req = local->scan_req; 658 int rc; 659 660 local->scan_req = NULL; 661 local->scan_sdata = NULL; 662 663 rc = __ieee80211_start_scan(sdata, req); 664 mutex_unlock(&local->scan_mtx); 665 666 if (rc) 667 ieee80211_scan_completed(&local->hw, true); 668 return; 669 } 670 671 mutex_unlock(&local->scan_mtx); 672 673 /* 674 * Avoid re-scheduling when the sdata is going away. 675 */ 676 if (!ieee80211_sdata_running(sdata)) { 677 ieee80211_scan_completed(&local->hw, true); 678 return; 679 } 680 681 /* 682 * as long as no delay is required advance immediately 683 * without scheduling a new work 684 */ 685 do { 686 switch (local->next_scan_state) { 687 case SCAN_DECISION: 688 if (ieee80211_scan_state_decision(local, &next_delay)) 689 return; 690 break; 691 case SCAN_SET_CHANNEL: 692 ieee80211_scan_state_set_channel(local, &next_delay); 693 break; 694 case SCAN_SEND_PROBE: 695 ieee80211_scan_state_send_probe(local, &next_delay); 696 break; 697 case SCAN_LEAVE_OPER_CHANNEL: 698 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 699 break; 700 case SCAN_ENTER_OPER_CHANNEL: 701 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 702 break; 703 } 704 } while (next_delay == 0); 705 706 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 707} 708 709int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 710 struct cfg80211_scan_request *req) 711{ 712 int res; 713 714 mutex_lock(&sdata->local->scan_mtx); 715 res = __ieee80211_start_scan(sdata, req); 716 mutex_unlock(&sdata->local->scan_mtx); 717 718 return res; 719} 720 721int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 722 const u8 *ssid, u8 ssid_len, 723 struct ieee80211_channel *chan) 724{ 725 struct ieee80211_local *local = sdata->local; 726 int ret = -EBUSY; 727 enum ieee80211_band band; 728 729 mutex_lock(&local->scan_mtx); 730 731 /* busy scanning */ 732 if (local->scan_req) 733 goto unlock; 734 735 /* fill internal scan request */ 736 if (!chan) { 737 int i, nchan = 0; 738 739 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 740 if (!local->hw.wiphy->bands[band]) 741 continue; 742 for (i = 0; 743 i < local->hw.wiphy->bands[band]->n_channels; 744 i++) { 745 local->int_scan_req->channels[nchan] = 746 &local->hw.wiphy->bands[band]->channels[i]; 747 nchan++; 748 } 749 } 750 751 local->int_scan_req->n_channels = nchan; 752 } else { 753 local->int_scan_req->channels[0] = chan; 754 local->int_scan_req->n_channels = 1; 755 } 756 757 local->int_scan_req->ssids = &local->scan_ssid; 758 local->int_scan_req->n_ssids = 1; 759 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 760 local->int_scan_req->ssids[0].ssid_len = ssid_len; 761 762 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 763 unlock: 764 mutex_unlock(&local->scan_mtx); 765 return ret; 766} 767 768void ieee80211_scan_cancel(struct ieee80211_local *local) 769{ 770 bool abortscan; 771 772 cancel_delayed_work_sync(&local->scan_work); 773 774 /* 775 * Only call this function when a scan can't be 776 * queued -- mostly at suspend under RTNL. 777 */ 778 mutex_lock(&local->scan_mtx); 779 abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || 780 (!local->scanning && local->scan_req); 781 mutex_unlock(&local->scan_mtx); 782 783 if (abortscan) 784 ieee80211_scan_completed(&local->hw, true); 785} 786