scan.c revision 6d3560d4fc9c5b9fe1a07a63926ea70512c69c32
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/wireless.h> 16#include <linux/if_arp.h> 17#include <linux/rtnetlink.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 28struct ieee80211_bss * 29ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, 30 u8 *ssid, u8 ssid_len) 31{ 32 return (void *)cfg80211_get_bss(local->hw.wiphy, 33 ieee80211_get_channel(local->hw.wiphy, 34 freq), 35 bssid, ssid, ssid_len, 36 0, 0); 37} 38 39static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) 40{ 41 struct ieee80211_bss *bss = (void *)cbss; 42 43 kfree(bss_mesh_id(bss)); 44 kfree(bss_mesh_cfg(bss)); 45} 46 47void ieee80211_rx_bss_put(struct ieee80211_local *local, 48 struct ieee80211_bss *bss) 49{ 50 cfg80211_put_bss((struct cfg80211_bss *)bss); 51} 52 53struct ieee80211_bss * 54ieee80211_bss_info_update(struct ieee80211_local *local, 55 struct ieee80211_rx_status *rx_status, 56 struct ieee80211_mgmt *mgmt, 57 size_t len, 58 struct ieee802_11_elems *elems, 59 struct ieee80211_channel *channel, 60 bool beacon) 61{ 62 struct ieee80211_bss *bss; 63 int clen; 64 s32 signal = 0; 65 66 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 67 signal = rx_status->signal * 100; 68 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 69 signal = (rx_status->signal * 100) / local->hw.max_signal; 70 71 bss = (void *)cfg80211_inform_bss_frame(local->hw.wiphy, channel, 72 mgmt, len, signal, GFP_ATOMIC); 73 74 if (!bss) 75 return NULL; 76 77 bss->cbss.free_priv = ieee80211_rx_bss_free; 78 79 /* save the ERP value so that it is available at association time */ 80 if (elems->erp_info && elems->erp_info_len >= 1) { 81 bss->erp_value = elems->erp_info[0]; 82 bss->has_erp_value = 1; 83 } 84 85 if (elems->tim) { 86 struct ieee80211_tim_ie *tim_ie = 87 (struct ieee80211_tim_ie *)elems->tim; 88 bss->dtim_period = tim_ie->dtim_period; 89 } 90 91 /* set default value for buggy AP/no TIM element */ 92 if (bss->dtim_period == 0) 93 bss->dtim_period = 1; 94 95 bss->supp_rates_len = 0; 96 if (elems->supp_rates) { 97 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; 98 if (clen > elems->supp_rates_len) 99 clen = elems->supp_rates_len; 100 memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates, 101 clen); 102 bss->supp_rates_len += clen; 103 } 104 if (elems->ext_supp_rates) { 105 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; 106 if (clen > elems->ext_supp_rates_len) 107 clen = elems->ext_supp_rates_len; 108 memcpy(&bss->supp_rates[bss->supp_rates_len], 109 elems->ext_supp_rates, clen); 110 bss->supp_rates_len += clen; 111 } 112 113 bss->wmm_used = elems->wmm_param || elems->wmm_info; 114 115 if (!beacon) 116 bss->last_probe_resp = jiffies; 117 118 return bss; 119} 120 121ieee80211_rx_result 122ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 123{ 124 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 125 struct ieee80211_mgmt *mgmt; 126 struct ieee80211_bss *bss; 127 u8 *elements; 128 struct ieee80211_channel *channel; 129 size_t baselen; 130 int freq; 131 __le16 fc; 132 bool presp, beacon = false; 133 struct ieee802_11_elems elems; 134 135 if (skb->len < 2) 136 return RX_DROP_UNUSABLE; 137 138 mgmt = (struct ieee80211_mgmt *) skb->data; 139 fc = mgmt->frame_control; 140 141 if (ieee80211_is_ctl(fc)) 142 return RX_CONTINUE; 143 144 if (skb->len < 24) 145 return RX_DROP_MONITOR; 146 147 presp = ieee80211_is_probe_resp(fc); 148 if (presp) { 149 /* ignore ProbeResp to foreign address */ 150 if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN)) 151 return RX_DROP_MONITOR; 152 153 presp = true; 154 elements = mgmt->u.probe_resp.variable; 155 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 156 } else { 157 beacon = ieee80211_is_beacon(fc); 158 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 159 elements = mgmt->u.beacon.variable; 160 } 161 162 if (!presp && !beacon) 163 return RX_CONTINUE; 164 165 if (baselen > skb->len) 166 return RX_DROP_MONITOR; 167 168 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 169 170 if (elems.ds_params && elems.ds_params_len == 1) 171 freq = ieee80211_channel_to_frequency(elems.ds_params[0]); 172 else 173 freq = rx_status->freq; 174 175 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 176 177 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 178 return RX_DROP_MONITOR; 179 180 bss = ieee80211_bss_info_update(sdata->local, rx_status, 181 mgmt, skb->len, &elems, 182 channel, beacon); 183 if (bss) 184 ieee80211_rx_bss_put(sdata->local, bss); 185 186 dev_kfree_skb(skb); 187 return RX_QUEUED; 188} 189 190/* return false if no more work */ 191static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 192{ 193 struct cfg80211_scan_request *req = local->scan_req; 194 enum ieee80211_band band; 195 int i, ielen, n_chans; 196 197 do { 198 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 199 return false; 200 201 band = local->hw_scan_band; 202 n_chans = 0; 203 for (i = 0; i < req->n_channels; i++) { 204 if (req->channels[i]->band == band) { 205 local->hw_scan_req->channels[n_chans] = 206 req->channels[i]; 207 n_chans++; 208 } 209 } 210 211 local->hw_scan_band++; 212 } while (!n_chans); 213 214 local->hw_scan_req->n_channels = n_chans; 215 216 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 217 req->ie, req->ie_len, band); 218 local->hw_scan_req->ie_len = ielen; 219 220 return true; 221} 222 223/* 224 * inform AP that we will go to sleep so that it will buffer the frames 225 * while we scan 226 */ 227static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata) 228{ 229 struct ieee80211_local *local = sdata->local; 230 bool ps = false; 231 232 /* FIXME: what to do when local->pspolling is true? */ 233 234 del_timer_sync(&local->dynamic_ps_timer); 235 cancel_work_sync(&local->dynamic_ps_enable_work); 236 237 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 238 ps = true; 239 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 240 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 241 } 242 243 if (!ps || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) 244 /* 245 * If power save was enabled, no need to send a nullfunc 246 * frame because AP knows that we are sleeping. But if the 247 * hardware is creating the nullfunc frame for power save 248 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 249 * enabled) and power save was enabled, the firmware just 250 * sent a null frame with power save disabled. So we need 251 * to send a new nullfunc frame to inform the AP that we 252 * are again sleeping. 253 */ 254 ieee80211_send_nullfunc(local, sdata, 1); 255} 256 257/* inform AP that we are awake again, unless power save is enabled */ 258static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata) 259{ 260 struct ieee80211_local *local = sdata->local; 261 262 if (!local->ps_sdata) 263 ieee80211_send_nullfunc(local, sdata, 0); 264 else { 265 /* 266 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 267 * will send a nullfunc frame with the powersave bit set 268 * even though the AP already knows that we are sleeping. 269 * This could be avoided by sending a null frame with power 270 * save bit disabled before enabling the power save, but 271 * this doesn't gain anything. 272 * 273 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 274 * to send a nullfunc frame because AP already knows that 275 * we are sleeping, let's just enable power save mode in 276 * hardware. 277 */ 278 local->hw.conf.flags |= IEEE80211_CONF_PS; 279 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 280 } 281} 282 283void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 284{ 285 struct ieee80211_local *local = hw_to_local(hw); 286 struct ieee80211_sub_if_data *sdata; 287 bool was_hw_scan; 288 289 mutex_lock(&local->scan_mtx); 290 291 /* 292 * It's ok to abort a not-yet-running scan (that 293 * we have one at all will be verified by checking 294 * local->scan_req next), but not to complete it 295 * successfully. 296 */ 297 if (WARN_ON(!local->scanning && !aborted)) 298 aborted = true; 299 300 if (WARN_ON(!local->scan_req)) { 301 mutex_unlock(&local->scan_mtx); 302 return; 303 } 304 305 was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 306 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 307 ieee80211_queue_delayed_work(&local->hw, 308 &local->scan_work, 0); 309 mutex_unlock(&local->scan_mtx); 310 return; 311 } 312 313 kfree(local->hw_scan_req); 314 local->hw_scan_req = NULL; 315 316 if (local->scan_req != local->int_scan_req) 317 cfg80211_scan_done(local->scan_req, aborted); 318 local->scan_req = NULL; 319 local->scan_sdata = NULL; 320 321 local->scanning = 0; 322 local->scan_channel = NULL; 323 324 /* we only have to protect scan_req and hw/sw scan */ 325 mutex_unlock(&local->scan_mtx); 326 327 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 328 if (was_hw_scan) 329 goto done; 330 331 ieee80211_configure_filter(local); 332 333 drv_sw_scan_complete(local); 334 335 mutex_lock(&local->iflist_mtx); 336 list_for_each_entry(sdata, &local->interfaces, list) { 337 if (!netif_running(sdata->dev)) 338 continue; 339 340 /* Tell AP we're back */ 341 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 342 if (sdata->u.mgd.associated) { 343 ieee80211_scan_ps_disable(sdata); 344 netif_wake_queue(sdata->dev); 345 } 346 } else 347 netif_wake_queue(sdata->dev); 348 349 /* re-enable beaconing */ 350 if (sdata->vif.type == NL80211_IFTYPE_AP || 351 sdata->vif.type == NL80211_IFTYPE_ADHOC || 352 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 353 ieee80211_bss_info_change_notify( 354 sdata, BSS_CHANGED_BEACON_ENABLED); 355 } 356 mutex_unlock(&local->iflist_mtx); 357 358 done: 359 ieee80211_recalc_idle(local); 360 ieee80211_mlme_notify_scan_completed(local); 361 ieee80211_ibss_notify_scan_completed(local); 362 ieee80211_mesh_notify_scan_completed(local); 363} 364EXPORT_SYMBOL(ieee80211_scan_completed); 365 366static int ieee80211_start_sw_scan(struct ieee80211_local *local) 367{ 368 struct ieee80211_sub_if_data *sdata; 369 370 /* 371 * Hardware/driver doesn't support hw_scan, so use software 372 * scanning instead. First send a nullfunc frame with power save 373 * bit on so that AP will buffer the frames for us while we are not 374 * listening, then send probe requests to each channel and wait for 375 * the responses. After all channels are scanned, tune back to the 376 * original channel and send a nullfunc frame with power save bit 377 * off to trigger the AP to send us all the buffered frames. 378 * 379 * Note that while local->sw_scanning is true everything else but 380 * nullfunc frames and probe requests will be dropped in 381 * ieee80211_tx_h_check_assoc(). 382 */ 383 drv_sw_scan_start(local); 384 385 mutex_lock(&local->iflist_mtx); 386 list_for_each_entry(sdata, &local->interfaces, list) { 387 if (!netif_running(sdata->dev)) 388 continue; 389 390 /* disable beaconing */ 391 if (sdata->vif.type == NL80211_IFTYPE_AP || 392 sdata->vif.type == NL80211_IFTYPE_ADHOC || 393 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 394 ieee80211_bss_info_change_notify( 395 sdata, BSS_CHANGED_BEACON_ENABLED); 396 397 /* 398 * only handle non-STA interfaces here, STA interfaces 399 * are handled in the scan state machine 400 */ 401 if (sdata->vif.type != NL80211_IFTYPE_STATION) 402 netif_stop_queue(sdata->dev); 403 } 404 mutex_unlock(&local->iflist_mtx); 405 406 local->next_scan_state = SCAN_DECISION; 407 local->scan_channel_idx = 0; 408 409 ieee80211_configure_filter(local); 410 411 /* TODO: start scan as soon as all nullfunc frames are ACKed */ 412 ieee80211_queue_delayed_work(&local->hw, 413 &local->scan_work, 414 IEEE80211_CHANNEL_TIME); 415 416 return 0; 417} 418 419 420static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 421 struct cfg80211_scan_request *req) 422{ 423 struct ieee80211_local *local = sdata->local; 424 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 425 int rc; 426 427 if (local->scan_req) 428 return -EBUSY; 429 430 if (local->ops->hw_scan) { 431 u8 *ies; 432 433 local->hw_scan_req = kmalloc( 434 sizeof(*local->hw_scan_req) + 435 req->n_channels * sizeof(req->channels[0]) + 436 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 437 req->ie_len, GFP_KERNEL); 438 if (!local->hw_scan_req) 439 return -ENOMEM; 440 441 local->hw_scan_req->ssids = req->ssids; 442 local->hw_scan_req->n_ssids = req->n_ssids; 443 ies = (u8 *)local->hw_scan_req + 444 sizeof(*local->hw_scan_req) + 445 req->n_channels * sizeof(req->channels[0]); 446 local->hw_scan_req->ie = ies; 447 448 local->hw_scan_band = 0; 449 } 450 451 local->scan_req = req; 452 local->scan_sdata = sdata; 453 454 if (req != local->int_scan_req && 455 sdata->vif.type == NL80211_IFTYPE_STATION && 456 !list_empty(&ifmgd->work_list)) { 457 /* actually wait for the work it's doing to finish/time out */ 458 set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request); 459 return 0; 460 } 461 462 if (local->ops->hw_scan) 463 __set_bit(SCAN_HW_SCANNING, &local->scanning); 464 else 465 __set_bit(SCAN_SW_SCANNING, &local->scanning); 466 /* 467 * Kicking off the scan need not be protected, 468 * only the scan variable stuff, since now 469 * local->scan_req is assigned and other callers 470 * will abort their scan attempts. 471 * 472 * This avoids getting a scan_mtx -> iflist_mtx 473 * dependency, so that the scan completed calls 474 * have more locking freedom. 475 */ 476 477 ieee80211_recalc_idle(local); 478 mutex_unlock(&local->scan_mtx); 479 480 if (local->ops->hw_scan) { 481 WARN_ON(!ieee80211_prep_hw_scan(local)); 482 rc = drv_hw_scan(local, local->hw_scan_req); 483 } else 484 rc = ieee80211_start_sw_scan(local); 485 486 mutex_lock(&local->scan_mtx); 487 488 if (rc) { 489 kfree(local->hw_scan_req); 490 local->hw_scan_req = NULL; 491 local->scanning = 0; 492 493 ieee80211_recalc_idle(local); 494 495 local->scan_req = NULL; 496 local->scan_sdata = NULL; 497 } 498 499 return rc; 500} 501 502static int ieee80211_scan_state_decision(struct ieee80211_local *local, 503 unsigned long *next_delay) 504{ 505 bool associated = false; 506 struct ieee80211_sub_if_data *sdata; 507 508 /* if no more bands/channels left, complete scan and advance to the idle state */ 509 if (local->scan_channel_idx >= local->scan_req->n_channels) { 510 ieee80211_scan_completed(&local->hw, false); 511 return 1; 512 } 513 514 /* check if at least one STA interface is associated */ 515 mutex_lock(&local->iflist_mtx); 516 list_for_each_entry(sdata, &local->interfaces, list) { 517 if (!netif_running(sdata->dev)) 518 continue; 519 520 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 521 if (sdata->u.mgd.associated) { 522 associated = true; 523 break; 524 } 525 } 526 } 527 mutex_unlock(&local->iflist_mtx); 528 529 if (local->scan_channel) { 530 /* 531 * we're currently scanning a different channel, let's 532 * switch back to the operating channel now if at least 533 * one interface is associated. Otherwise just scan the 534 * next channel 535 */ 536 if (associated) 537 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 538 else 539 local->next_scan_state = SCAN_SET_CHANNEL; 540 } else { 541 /* 542 * we're on the operating channel currently, let's 543 * leave that channel now to scan another one 544 */ 545 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 546 } 547 548 *next_delay = 0; 549 return 0; 550} 551 552static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 553 unsigned long *next_delay) 554{ 555 struct ieee80211_sub_if_data *sdata; 556 557 /* 558 * notify the AP about us leaving the channel and stop all STA interfaces 559 */ 560 mutex_lock(&local->iflist_mtx); 561 list_for_each_entry(sdata, &local->interfaces, list) { 562 if (!netif_running(sdata->dev)) 563 continue; 564 565 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 566 netif_stop_queue(sdata->dev); 567 if (sdata->u.mgd.associated) 568 ieee80211_scan_ps_enable(sdata); 569 } 570 } 571 mutex_unlock(&local->iflist_mtx); 572 573 __set_bit(SCAN_OFF_CHANNEL, &local->scanning); 574 575 /* advance to the next channel to be scanned */ 576 *next_delay = HZ / 10; 577 local->next_scan_state = SCAN_SET_CHANNEL; 578} 579 580static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 581 unsigned long *next_delay) 582{ 583 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 584 585 /* switch back to the operating channel */ 586 local->scan_channel = NULL; 587 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 588 589 /* 590 * notify the AP about us being back and restart all STA interfaces 591 */ 592 mutex_lock(&local->iflist_mtx); 593 list_for_each_entry(sdata, &local->interfaces, list) { 594 if (!netif_running(sdata->dev)) 595 continue; 596 597 /* Tell AP we're back */ 598 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 599 if (sdata->u.mgd.associated) 600 ieee80211_scan_ps_disable(sdata); 601 netif_wake_queue(sdata->dev); 602 } 603 } 604 mutex_unlock(&local->iflist_mtx); 605 606 __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); 607 608 *next_delay = HZ / 5; 609 local->next_scan_state = SCAN_DECISION; 610} 611 612static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 613 unsigned long *next_delay) 614{ 615 int skip; 616 struct ieee80211_channel *chan; 617 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 618 619 skip = 0; 620 chan = local->scan_req->channels[local->scan_channel_idx]; 621 622 if (chan->flags & IEEE80211_CHAN_DISABLED || 623 (sdata->vif.type == NL80211_IFTYPE_ADHOC && 624 chan->flags & IEEE80211_CHAN_NO_IBSS)) 625 skip = 1; 626 627 if (!skip) { 628 local->scan_channel = chan; 629 if (ieee80211_hw_config(local, 630 IEEE80211_CONF_CHANGE_CHANNEL)) 631 skip = 1; 632 } 633 634 /* advance state machine to next channel/band */ 635 local->scan_channel_idx++; 636 637 if (skip) { 638 /* if we skip this channel return to the decision state */ 639 local->next_scan_state = SCAN_DECISION; 640 return; 641 } 642 643 /* 644 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 645 * (which unfortunately doesn't say _why_ step a) is done, 646 * but it waits for the probe delay or until a frame is 647 * received - and the received frame would update the NAV). 648 * For now, we do not support waiting until a frame is 649 * received. 650 * 651 * In any case, it is not necessary for a passive scan. 652 */ 653 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 654 !local->scan_req->n_ssids) { 655 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 656 local->next_scan_state = SCAN_DECISION; 657 return; 658 } 659 660 /* active scan, send probes */ 661 *next_delay = IEEE80211_PROBE_DELAY; 662 local->next_scan_state = SCAN_SEND_PROBE; 663} 664 665static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 666 unsigned long *next_delay) 667{ 668 int i; 669 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 670 671 for (i = 0; i < local->scan_req->n_ssids; i++) 672 ieee80211_send_probe_req( 673 sdata, NULL, 674 local->scan_req->ssids[i].ssid, 675 local->scan_req->ssids[i].ssid_len, 676 local->scan_req->ie, local->scan_req->ie_len); 677 678 /* 679 * After sending probe requests, wait for probe responses 680 * on the channel. 681 */ 682 *next_delay = IEEE80211_CHANNEL_TIME; 683 local->next_scan_state = SCAN_DECISION; 684} 685 686void ieee80211_scan_work(struct work_struct *work) 687{ 688 struct ieee80211_local *local = 689 container_of(work, struct ieee80211_local, scan_work.work); 690 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 691 unsigned long next_delay = 0; 692 693 mutex_lock(&local->scan_mtx); 694 if (!sdata || !local->scan_req) { 695 mutex_unlock(&local->scan_mtx); 696 return; 697 } 698 699 if (local->hw_scan_req) { 700 int rc = drv_hw_scan(local, local->hw_scan_req); 701 mutex_unlock(&local->scan_mtx); 702 if (rc) 703 ieee80211_scan_completed(&local->hw, true); 704 return; 705 } 706 707 if (local->scan_req && !local->scanning) { 708 struct cfg80211_scan_request *req = local->scan_req; 709 int rc; 710 711 local->scan_req = NULL; 712 local->scan_sdata = NULL; 713 714 rc = __ieee80211_start_scan(sdata, req); 715 mutex_unlock(&local->scan_mtx); 716 717 if (rc) 718 ieee80211_scan_completed(&local->hw, true); 719 return; 720 } 721 722 mutex_unlock(&local->scan_mtx); 723 724 /* 725 * Avoid re-scheduling when the sdata is going away. 726 */ 727 if (!netif_running(sdata->dev)) { 728 ieee80211_scan_completed(&local->hw, true); 729 return; 730 } 731 732 /* 733 * as long as no delay is required advance immediately 734 * without scheduling a new work 735 */ 736 do { 737 switch (local->next_scan_state) { 738 case SCAN_DECISION: 739 if (ieee80211_scan_state_decision(local, &next_delay)) 740 return; 741 break; 742 case SCAN_SET_CHANNEL: 743 ieee80211_scan_state_set_channel(local, &next_delay); 744 break; 745 case SCAN_SEND_PROBE: 746 ieee80211_scan_state_send_probe(local, &next_delay); 747 break; 748 case SCAN_LEAVE_OPER_CHANNEL: 749 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 750 break; 751 case SCAN_ENTER_OPER_CHANNEL: 752 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 753 break; 754 } 755 } while (next_delay == 0); 756 757 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 758} 759 760int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 761 struct cfg80211_scan_request *req) 762{ 763 int res; 764 765 mutex_lock(&sdata->local->scan_mtx); 766 res = __ieee80211_start_scan(sdata, req); 767 mutex_unlock(&sdata->local->scan_mtx); 768 769 return res; 770} 771 772int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 773 const u8 *ssid, u8 ssid_len) 774{ 775 struct ieee80211_local *local = sdata->local; 776 int ret = -EBUSY; 777 778 mutex_lock(&local->scan_mtx); 779 780 /* busy scanning */ 781 if (local->scan_req) 782 goto unlock; 783 784 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 785 local->int_scan_req->ssids[0].ssid_len = ssid_len; 786 787 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 788 unlock: 789 mutex_unlock(&local->scan_mtx); 790 return ret; 791} 792 793void ieee80211_scan_cancel(struct ieee80211_local *local) 794{ 795 bool abortscan; 796 797 cancel_delayed_work_sync(&local->scan_work); 798 799 /* 800 * Only call this function when a scan can't be 801 * queued -- mostly at suspend under RTNL. 802 */ 803 mutex_lock(&local->scan_mtx); 804 abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || 805 (!local->scanning && local->scan_req); 806 mutex_unlock(&local->scan_mtx); 807 808 if (abortscan) 809 ieee80211_scan_completed(&local->hw, true); 810} 811