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 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 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 39 static 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 47 void ieee80211_rx_bss_put(struct ieee80211_local *local, 48 struct ieee80211_bss *bss) 49 { 50 cfg80211_put_bss((struct cfg80211_bss *)bss); 51 } 52 53 struct ieee80211_bss * 54 ieee80211_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 } 120 121 ieee80211_rx_result 122 ieee80211_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 */ 191 static 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 */ 227 static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata) 228 { 229 struct ieee80211_local *local = sdata->local; 230 231 local->scan_ps_enabled = false; 232 233 /* FIXME: what to do when local->pspolling is true? */ 234 235 del_timer_sync(&local->dynamic_ps_timer); 236 cancel_work_sync(&local->dynamic_ps_enable_work); 237 238 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 239 local->scan_ps_enabled = true; 240 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 241 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 242 } 243 244 if (!(local->scan_ps_enabled) || 245 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) 246 /* 247 * If power save was enabled, no need to send a nullfunc 248 * frame because AP knows that we are sleeping. But if the 249 * hardware is creating the nullfunc frame for power save 250 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 251 * enabled) and power save was enabled, the firmware just 252 * sent a null frame with power save disabled. So we need 253 * to send a new nullfunc frame to inform the AP that we 254 * are again sleeping. 255 */ 256 ieee80211_send_nullfunc(local, sdata, 1); 257 } 258 259 /* inform AP that we are awake again, unless power save is enabled */ 260 static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata) 261 { 262 struct ieee80211_local *local = sdata->local; 263 264 if (!local->ps_sdata) 265 ieee80211_send_nullfunc(local, sdata, 0); 266 else if (local->scan_ps_enabled) { 267 /* 268 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 269 * will send a nullfunc frame with the powersave bit set 270 * even though the AP already knows that we are sleeping. 271 * This could be avoided by sending a null frame with power 272 * save bit disabled before enabling the power save, but 273 * this doesn't gain anything. 274 * 275 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 276 * to send a nullfunc frame because AP already knows that 277 * we are sleeping, let's just enable power save mode in 278 * hardware. 279 */ 280 local->hw.conf.flags |= IEEE80211_CONF_PS; 281 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 282 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 283 /* 284 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 285 * had been running before leaving the operating channel, 286 * restart the timer now and send a nullfunc frame to inform 287 * the AP that we are awake. 288 */ 289 ieee80211_send_nullfunc(local, sdata, 0); 290 mod_timer(&local->dynamic_ps_timer, jiffies + 291 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 292 } 293 } 294 295 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 296 { 297 struct ieee80211_local *local = hw_to_local(hw); 298 struct ieee80211_sub_if_data *sdata; 299 bool was_hw_scan; 300 301 mutex_lock(&local->scan_mtx); 302 303 /* 304 * It's ok to abort a not-yet-running scan (that 305 * we have one at all will be verified by checking 306 * local->scan_req next), but not to complete it 307 * successfully. 308 */ 309 if (WARN_ON(!local->scanning && !aborted)) 310 aborted = true; 311 312 if (WARN_ON(!local->scan_req)) { 313 mutex_unlock(&local->scan_mtx); 314 return; 315 } 316 317 was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 318 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 319 ieee80211_queue_delayed_work(&local->hw, 320 &local->scan_work, 0); 321 mutex_unlock(&local->scan_mtx); 322 return; 323 } 324 325 kfree(local->hw_scan_req); 326 local->hw_scan_req = NULL; 327 328 if (local->scan_req != local->int_scan_req) 329 cfg80211_scan_done(local->scan_req, aborted); 330 local->scan_req = NULL; 331 local->scan_sdata = NULL; 332 333 local->scanning = 0; 334 local->scan_channel = NULL; 335 336 /* we only have to protect scan_req and hw/sw scan */ 337 mutex_unlock(&local->scan_mtx); 338 339 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 340 if (was_hw_scan) 341 goto done; 342 343 ieee80211_configure_filter(local); 344 345 drv_sw_scan_complete(local); 346 347 mutex_lock(&local->iflist_mtx); 348 list_for_each_entry(sdata, &local->interfaces, list) { 349 if (!netif_running(sdata->dev)) 350 continue; 351 352 /* Tell AP we're back */ 353 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 354 if (sdata->u.mgd.associated) { 355 ieee80211_scan_ps_disable(sdata); 356 netif_tx_wake_all_queues(sdata->dev); 357 } 358 } else 359 netif_tx_wake_all_queues(sdata->dev); 360 361 /* re-enable beaconing */ 362 if (sdata->vif.type == NL80211_IFTYPE_AP || 363 sdata->vif.type == NL80211_IFTYPE_ADHOC || 364 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 365 ieee80211_bss_info_change_notify( 366 sdata, BSS_CHANGED_BEACON_ENABLED); 367 } 368 mutex_unlock(&local->iflist_mtx); 369 370 done: 371 ieee80211_recalc_idle(local); 372 ieee80211_mlme_notify_scan_completed(local); 373 ieee80211_ibss_notify_scan_completed(local); 374 ieee80211_mesh_notify_scan_completed(local); 375 } 376 EXPORT_SYMBOL(ieee80211_scan_completed); 377 378 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 379 { 380 struct ieee80211_sub_if_data *sdata; 381 382 /* 383 * Hardware/driver doesn't support hw_scan, so use software 384 * scanning instead. First send a nullfunc frame with power save 385 * bit on so that AP will buffer the frames for us while we are not 386 * listening, then send probe requests to each channel and wait for 387 * the responses. After all channels are scanned, tune back to the 388 * original channel and send a nullfunc frame with power save bit 389 * off to trigger the AP to send us all the buffered frames. 390 * 391 * Note that while local->sw_scanning is true everything else but 392 * nullfunc frames and probe requests will be dropped in 393 * ieee80211_tx_h_check_assoc(). 394 */ 395 drv_sw_scan_start(local); 396 397 mutex_lock(&local->iflist_mtx); 398 list_for_each_entry(sdata, &local->interfaces, list) { 399 if (!netif_running(sdata->dev)) 400 continue; 401 402 /* disable beaconing */ 403 if (sdata->vif.type == NL80211_IFTYPE_AP || 404 sdata->vif.type == NL80211_IFTYPE_ADHOC || 405 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 406 ieee80211_bss_info_change_notify( 407 sdata, BSS_CHANGED_BEACON_ENABLED); 408 409 /* 410 * only handle non-STA interfaces here, STA interfaces 411 * are handled in the scan state machine 412 */ 413 if (sdata->vif.type != NL80211_IFTYPE_STATION) 414 netif_tx_stop_all_queues(sdata->dev); 415 } 416 mutex_unlock(&local->iflist_mtx); 417 418 local->next_scan_state = SCAN_DECISION; 419 local->scan_channel_idx = 0; 420 421 ieee80211_configure_filter(local); 422 423 /* TODO: start scan as soon as all nullfunc frames are ACKed */ 424 ieee80211_queue_delayed_work(&local->hw, 425 &local->scan_work, 426 IEEE80211_CHANNEL_TIME); 427 428 return 0; 429 } 430 431 432 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 433 struct cfg80211_scan_request *req) 434 { 435 struct ieee80211_local *local = sdata->local; 436 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 437 int rc; 438 439 if (local->scan_req) 440 return -EBUSY; 441 442 if (req != local->int_scan_req && 443 sdata->vif.type == NL80211_IFTYPE_STATION && 444 !list_empty(&ifmgd->work_list)) { 445 /* actually wait for the work it's doing to finish/time out */ 446 set_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request); 447 local->scan_req = req; 448 local->scan_sdata = sdata; 449 return 0; 450 } 451 452 if (local->ops->hw_scan) { 453 u8 *ies; 454 455 local->hw_scan_req = kmalloc( 456 sizeof(*local->hw_scan_req) + 457 req->n_channels * sizeof(req->channels[0]) + 458 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 459 req->ie_len, GFP_KERNEL); 460 if (!local->hw_scan_req) 461 return -ENOMEM; 462 463 local->hw_scan_req->ssids = req->ssids; 464 local->hw_scan_req->n_ssids = req->n_ssids; 465 ies = (u8 *)local->hw_scan_req + 466 sizeof(*local->hw_scan_req) + 467 req->n_channels * sizeof(req->channels[0]); 468 local->hw_scan_req->ie = ies; 469 470 local->hw_scan_band = 0; 471 } 472 473 local->scan_req = req; 474 local->scan_sdata = sdata; 475 476 if (local->ops->hw_scan) 477 __set_bit(SCAN_HW_SCANNING, &local->scanning); 478 else 479 __set_bit(SCAN_SW_SCANNING, &local->scanning); 480 /* 481 * Kicking off the scan need not be protected, 482 * only the scan variable stuff, since now 483 * local->scan_req is assigned and other callers 484 * will abort their scan attempts. 485 * 486 * This avoids getting a scan_mtx -> iflist_mtx 487 * dependency, so that the scan completed calls 488 * have more locking freedom. 489 */ 490 491 ieee80211_recalc_idle(local); 492 mutex_unlock(&local->scan_mtx); 493 494 if (local->ops->hw_scan) { 495 WARN_ON(!ieee80211_prep_hw_scan(local)); 496 rc = drv_hw_scan(local, local->hw_scan_req); 497 } else 498 rc = ieee80211_start_sw_scan(local); 499 500 mutex_lock(&local->scan_mtx); 501 502 if (rc) { 503 kfree(local->hw_scan_req); 504 local->hw_scan_req = NULL; 505 local->scanning = 0; 506 507 ieee80211_recalc_idle(local); 508 509 local->scan_req = NULL; 510 local->scan_sdata = NULL; 511 } 512 513 return rc; 514 } 515 516 static int ieee80211_scan_state_decision(struct ieee80211_local *local, 517 unsigned long *next_delay) 518 { 519 bool associated = false; 520 struct ieee80211_sub_if_data *sdata; 521 522 /* if no more bands/channels left, complete scan and advance to the idle state */ 523 if (local->scan_channel_idx >= local->scan_req->n_channels) { 524 ieee80211_scan_completed(&local->hw, false); 525 return 1; 526 } 527 528 /* check if at least one STA interface is associated */ 529 mutex_lock(&local->iflist_mtx); 530 list_for_each_entry(sdata, &local->interfaces, list) { 531 if (!netif_running(sdata->dev)) 532 continue; 533 534 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 535 if (sdata->u.mgd.associated) { 536 associated = true; 537 break; 538 } 539 } 540 } 541 mutex_unlock(&local->iflist_mtx); 542 543 if (local->scan_channel) { 544 /* 545 * we're currently scanning a different channel, let's 546 * switch back to the operating channel now if at least 547 * one interface is associated. Otherwise just scan the 548 * next channel 549 */ 550 if (associated) 551 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 552 else 553 local->next_scan_state = SCAN_SET_CHANNEL; 554 } else { 555 /* 556 * we're on the operating channel currently, let's 557 * leave that channel now to scan another one 558 */ 559 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 560 } 561 562 *next_delay = 0; 563 return 0; 564 } 565 566 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 567 unsigned long *next_delay) 568 { 569 struct ieee80211_sub_if_data *sdata; 570 571 /* 572 * notify the AP about us leaving the channel and stop all STA interfaces 573 */ 574 mutex_lock(&local->iflist_mtx); 575 list_for_each_entry(sdata, &local->interfaces, list) { 576 if (!netif_running(sdata->dev)) 577 continue; 578 579 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 580 netif_tx_stop_all_queues(sdata->dev); 581 if (sdata->u.mgd.associated) 582 ieee80211_scan_ps_enable(sdata); 583 } 584 } 585 mutex_unlock(&local->iflist_mtx); 586 587 __set_bit(SCAN_OFF_CHANNEL, &local->scanning); 588 589 /* advance to the next channel to be scanned */ 590 *next_delay = HZ / 10; 591 local->next_scan_state = SCAN_SET_CHANNEL; 592 } 593 594 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 595 unsigned long *next_delay) 596 { 597 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 598 599 /* switch back to the operating channel */ 600 local->scan_channel = NULL; 601 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 602 603 /* 604 * notify the AP about us being back and restart all STA interfaces 605 */ 606 mutex_lock(&local->iflist_mtx); 607 list_for_each_entry(sdata, &local->interfaces, list) { 608 if (!netif_running(sdata->dev)) 609 continue; 610 611 /* Tell AP we're back */ 612 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 613 if (sdata->u.mgd.associated) 614 ieee80211_scan_ps_disable(sdata); 615 netif_tx_wake_all_queues(sdata->dev); 616 } 617 } 618 mutex_unlock(&local->iflist_mtx); 619 620 __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); 621 622 *next_delay = HZ / 5; 623 local->next_scan_state = SCAN_DECISION; 624 } 625 626 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 627 unsigned long *next_delay) 628 { 629 int skip; 630 struct ieee80211_channel *chan; 631 632 skip = 0; 633 chan = local->scan_req->channels[local->scan_channel_idx]; 634 635 local->scan_channel = chan; 636 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 637 skip = 1; 638 639 /* advance state machine to next channel/band */ 640 local->scan_channel_idx++; 641 642 if (skip) { 643 /* if we skip this channel return to the decision state */ 644 local->next_scan_state = SCAN_DECISION; 645 return; 646 } 647 648 /* 649 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 650 * (which unfortunately doesn't say _why_ step a) is done, 651 * but it waits for the probe delay or until a frame is 652 * received - and the received frame would update the NAV). 653 * For now, we do not support waiting until a frame is 654 * received. 655 * 656 * In any case, it is not necessary for a passive scan. 657 */ 658 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 659 !local->scan_req->n_ssids) { 660 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 661 local->next_scan_state = SCAN_DECISION; 662 return; 663 } 664 665 /* active scan, send probes */ 666 *next_delay = IEEE80211_PROBE_DELAY; 667 local->next_scan_state = SCAN_SEND_PROBE; 668 } 669 670 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 671 unsigned long *next_delay) 672 { 673 int i; 674 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 675 676 for (i = 0; i < local->scan_req->n_ssids; i++) 677 ieee80211_send_probe_req( 678 sdata, NULL, 679 local->scan_req->ssids[i].ssid, 680 local->scan_req->ssids[i].ssid_len, 681 local->scan_req->ie, local->scan_req->ie_len); 682 683 /* 684 * After sending probe requests, wait for probe responses 685 * on the channel. 686 */ 687 *next_delay = IEEE80211_CHANNEL_TIME; 688 local->next_scan_state = SCAN_DECISION; 689 } 690 691 void ieee80211_scan_work(struct work_struct *work) 692 { 693 struct ieee80211_local *local = 694 container_of(work, struct ieee80211_local, scan_work.work); 695 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 696 unsigned long next_delay = 0; 697 698 mutex_lock(&local->scan_mtx); 699 if (!sdata || !local->scan_req) { 700 mutex_unlock(&local->scan_mtx); 701 return; 702 } 703 704 if (local->hw_scan_req) { 705 int rc = drv_hw_scan(local, local->hw_scan_req); 706 mutex_unlock(&local->scan_mtx); 707 if (rc) 708 ieee80211_scan_completed(&local->hw, true); 709 return; 710 } 711 712 if (local->scan_req && !local->scanning) { 713 struct cfg80211_scan_request *req = local->scan_req; 714 int rc; 715 716 local->scan_req = NULL; 717 local->scan_sdata = NULL; 718 719 rc = __ieee80211_start_scan(sdata, req); 720 mutex_unlock(&local->scan_mtx); 721 722 if (rc) 723 ieee80211_scan_completed(&local->hw, true); 724 return; 725 } 726 727 mutex_unlock(&local->scan_mtx); 728 729 /* 730 * Avoid re-scheduling when the sdata is going away. 731 */ 732 if (!netif_running(sdata->dev)) { 733 ieee80211_scan_completed(&local->hw, true); 734 return; 735 } 736 737 /* 738 * as long as no delay is required advance immediately 739 * without scheduling a new work 740 */ 741 do { 742 switch (local->next_scan_state) { 743 case SCAN_DECISION: 744 if (ieee80211_scan_state_decision(local, &next_delay)) 745 return; 746 break; 747 case SCAN_SET_CHANNEL: 748 ieee80211_scan_state_set_channel(local, &next_delay); 749 break; 750 case SCAN_SEND_PROBE: 751 ieee80211_scan_state_send_probe(local, &next_delay); 752 break; 753 case SCAN_LEAVE_OPER_CHANNEL: 754 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 755 break; 756 case SCAN_ENTER_OPER_CHANNEL: 757 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 758 break; 759 } 760 } while (next_delay == 0); 761 762 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 763 } 764 765 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 766 struct cfg80211_scan_request *req) 767 { 768 int res; 769 770 mutex_lock(&sdata->local->scan_mtx); 771 res = __ieee80211_start_scan(sdata, req); 772 mutex_unlock(&sdata->local->scan_mtx); 773 774 return res; 775 } 776 777 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 778 const u8 *ssid, u8 ssid_len) 779 { 780 struct ieee80211_local *local = sdata->local; 781 int ret = -EBUSY; 782 783 mutex_lock(&local->scan_mtx); 784 785 /* busy scanning */ 786 if (local->scan_req) 787 goto unlock; 788 789 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 790 local->int_scan_req->ssids[0].ssid_len = ssid_len; 791 792 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 793 unlock: 794 mutex_unlock(&local->scan_mtx); 795 return ret; 796 } 797 798 void ieee80211_scan_cancel(struct ieee80211_local *local) 799 { 800 bool abortscan; 801 802 cancel_delayed_work_sync(&local->scan_work); 803 804 /* 805 * Only call this function when a scan can't be 806 * queued -- mostly at suspend under RTNL. 807 */ 808 mutex_lock(&local->scan_mtx); 809 abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || 810 (!local->scanning && local->scan_req); 811 mutex_unlock(&local->scan_mtx); 812 813 if (abortscan) 814 ieee80211_scan_completed(&local->hw, true); 815 } 816