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/etherdevice.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/pm_qos.h> 19 #include <net/sch_generic.h> 20 #include <linux/slab.h> 21 #include <linux/export.h> 22 #include <net/mac80211.h> 23 24 #include "ieee80211_i.h" 25 #include "driver-ops.h" 26 #include "mesh.h" 27 28 #define IEEE80211_PROBE_DELAY (HZ / 33) 29 #define IEEE80211_CHANNEL_TIME (HZ / 33) 30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9) 31 32 void ieee80211_rx_bss_put(struct ieee80211_local *local, 33 struct ieee80211_bss *bss) 34 { 35 if (!bss) 36 return; 37 cfg80211_put_bss(local->hw.wiphy, 38 container_of((void *)bss, struct cfg80211_bss, priv)); 39 } 40 41 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 42 { 43 u8 qos_info; 44 45 if (elems->wmm_info && elems->wmm_info_len == 7 46 && elems->wmm_info[5] == 1) 47 qos_info = elems->wmm_info[6]; 48 else if (elems->wmm_param && elems->wmm_param_len == 24 49 && elems->wmm_param[5] == 1) 50 qos_info = elems->wmm_param[6]; 51 else 52 /* no valid wmm information or parameter element found */ 53 return false; 54 55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 56 } 57 58 struct ieee80211_bss * 59 ieee80211_bss_info_update(struct ieee80211_local *local, 60 struct ieee80211_rx_status *rx_status, 61 struct ieee80211_mgmt *mgmt, size_t len, 62 struct ieee802_11_elems *elems, 63 struct ieee80211_channel *channel) 64 { 65 bool beacon = ieee80211_is_beacon(mgmt->frame_control); 66 struct cfg80211_bss *cbss; 67 struct ieee80211_bss *bss; 68 int clen, srlen; 69 s32 signal = 0; 70 71 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 72 signal = rx_status->signal * 100; 73 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 74 signal = (rx_status->signal * 100) / local->hw.max_signal; 75 76 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, 77 mgmt, len, signal, GFP_ATOMIC); 78 if (!cbss) 79 return NULL; 80 81 bss = (void *)cbss->priv; 82 83 if (beacon) 84 bss->device_ts_beacon = rx_status->device_timestamp; 85 else 86 bss->device_ts_presp = rx_status->device_timestamp; 87 88 if (elems->parse_error) { 89 if (beacon) 90 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 91 else 92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 93 } else { 94 if (beacon) 95 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 96 else 97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 98 } 99 100 /* save the ERP value so that it is available at association time */ 101 if (elems->erp_info && (!elems->parse_error || 102 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 103 bss->erp_value = elems->erp_info[0]; 104 bss->has_erp_value = true; 105 if (!elems->parse_error) 106 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 107 } 108 109 /* replace old supported rates if we get new values */ 110 if (!elems->parse_error || 111 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 112 srlen = 0; 113 if (elems->supp_rates) { 114 clen = IEEE80211_MAX_SUPP_RATES; 115 if (clen > elems->supp_rates_len) 116 clen = elems->supp_rates_len; 117 memcpy(bss->supp_rates, elems->supp_rates, clen); 118 srlen += clen; 119 } 120 if (elems->ext_supp_rates) { 121 clen = IEEE80211_MAX_SUPP_RATES - srlen; 122 if (clen > elems->ext_supp_rates_len) 123 clen = elems->ext_supp_rates_len; 124 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 125 clen); 126 srlen += clen; 127 } 128 if (srlen) { 129 bss->supp_rates_len = srlen; 130 if (!elems->parse_error) 131 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 132 } 133 } 134 135 if (!elems->parse_error || 136 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 137 bss->wmm_used = elems->wmm_param || elems->wmm_info; 138 bss->uapsd_supported = is_uapsd_supported(elems); 139 if (!elems->parse_error) 140 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 141 } 142 143 return bss; 144 } 145 146 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 147 { 148 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 149 struct ieee80211_sub_if_data *sdata1, *sdata2; 150 struct ieee80211_mgmt *mgmt = (void *)skb->data; 151 struct ieee80211_bss *bss; 152 u8 *elements; 153 struct ieee80211_channel *channel; 154 size_t baselen; 155 struct ieee802_11_elems elems; 156 157 if (skb->len < 24 || 158 (!ieee80211_is_probe_resp(mgmt->frame_control) && 159 !ieee80211_is_beacon(mgmt->frame_control))) 160 return; 161 162 sdata1 = rcu_dereference(local->scan_sdata); 163 sdata2 = rcu_dereference(local->sched_scan_sdata); 164 165 if (likely(!sdata1 && !sdata2)) 166 return; 167 168 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 169 /* ignore ProbeResp to foreign address */ 170 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) && 171 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr))) 172 return; 173 174 elements = mgmt->u.probe_resp.variable; 175 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 176 } else { 177 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 178 elements = mgmt->u.beacon.variable; 179 } 180 181 if (baselen > skb->len) 182 return; 183 184 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 185 186 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 187 188 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 189 return; 190 191 bss = ieee80211_bss_info_update(local, rx_status, 192 mgmt, skb->len, &elems, 193 channel); 194 if (bss) 195 ieee80211_rx_bss_put(local, bss); 196 } 197 198 /* return false if no more work */ 199 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 200 { 201 struct cfg80211_scan_request *req = local->scan_req; 202 enum ieee80211_band band; 203 int i, ielen, n_chans; 204 205 do { 206 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 207 return false; 208 209 band = local->hw_scan_band; 210 n_chans = 0; 211 for (i = 0; i < req->n_channels; i++) { 212 if (req->channels[i]->band == band) { 213 local->hw_scan_req->channels[n_chans] = 214 req->channels[i]; 215 n_chans++; 216 } 217 } 218 219 local->hw_scan_band++; 220 } while (!n_chans); 221 222 local->hw_scan_req->n_channels = n_chans; 223 224 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 225 local->hw_scan_ies_bufsize, 226 req->ie, req->ie_len, band, 227 req->rates[band], 0); 228 local->hw_scan_req->ie_len = ielen; 229 local->hw_scan_req->no_cck = req->no_cck; 230 231 return true; 232 } 233 234 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 235 bool was_hw_scan) 236 { 237 struct ieee80211_local *local = hw_to_local(hw); 238 239 lockdep_assert_held(&local->mtx); 240 241 /* 242 * It's ok to abort a not-yet-running scan (that 243 * we have one at all will be verified by checking 244 * local->scan_req next), but not to complete it 245 * successfully. 246 */ 247 if (WARN_ON(!local->scanning && !aborted)) 248 aborted = true; 249 250 if (WARN_ON(!local->scan_req)) 251 return; 252 253 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 254 int rc; 255 256 rc = drv_hw_scan(local, 257 rcu_dereference_protected(local->scan_sdata, 258 lockdep_is_held(&local->mtx)), 259 local->hw_scan_req); 260 261 if (rc == 0) 262 return; 263 } 264 265 kfree(local->hw_scan_req); 266 local->hw_scan_req = NULL; 267 268 if (local->scan_req != local->int_scan_req) 269 cfg80211_scan_done(local->scan_req, aborted); 270 local->scan_req = NULL; 271 rcu_assign_pointer(local->scan_sdata, NULL); 272 273 local->scanning = 0; 274 local->scan_channel = NULL; 275 276 /* Set power back to normal operating levels. */ 277 ieee80211_hw_config(local, 0); 278 279 if (!was_hw_scan) { 280 ieee80211_configure_filter(local); 281 drv_sw_scan_complete(local); 282 ieee80211_offchannel_return(local); 283 } 284 285 ieee80211_recalc_idle(local); 286 287 ieee80211_mlme_notify_scan_completed(local); 288 ieee80211_ibss_notify_scan_completed(local); 289 ieee80211_mesh_notify_scan_completed(local); 290 ieee80211_start_next_roc(local); 291 } 292 293 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 294 { 295 struct ieee80211_local *local = hw_to_local(hw); 296 297 trace_api_scan_completed(local, aborted); 298 299 set_bit(SCAN_COMPLETED, &local->scanning); 300 if (aborted) 301 set_bit(SCAN_ABORTED, &local->scanning); 302 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 303 } 304 EXPORT_SYMBOL(ieee80211_scan_completed); 305 306 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 307 { 308 /* Software scan is not supported in multi-channel cases */ 309 if (local->use_chanctx) 310 return -EOPNOTSUPP; 311 312 /* 313 * Hardware/driver doesn't support hw_scan, so use software 314 * scanning instead. First send a nullfunc frame with power save 315 * bit on so that AP will buffer the frames for us while we are not 316 * listening, then send probe requests to each channel and wait for 317 * the responses. After all channels are scanned, tune back to the 318 * original channel and send a nullfunc frame with power save bit 319 * off to trigger the AP to send us all the buffered frames. 320 * 321 * Note that while local->sw_scanning is true everything else but 322 * nullfunc frames and probe requests will be dropped in 323 * ieee80211_tx_h_check_assoc(). 324 */ 325 drv_sw_scan_start(local); 326 327 local->leave_oper_channel_time = jiffies; 328 local->next_scan_state = SCAN_DECISION; 329 local->scan_channel_idx = 0; 330 331 ieee80211_offchannel_stop_vifs(local); 332 333 /* ensure nullfunc is transmitted before leaving operating channel */ 334 ieee80211_flush_queues(local, NULL); 335 336 ieee80211_configure_filter(local); 337 338 /* We need to set power level at maximum rate for scanning. */ 339 ieee80211_hw_config(local, 0); 340 341 ieee80211_queue_delayed_work(&local->hw, 342 &local->scan_work, 0); 343 344 return 0; 345 } 346 347 static bool ieee80211_can_scan(struct ieee80211_local *local, 348 struct ieee80211_sub_if_data *sdata) 349 { 350 if (local->radar_detect_enabled) 351 return false; 352 353 if (!list_empty(&local->roc_list)) 354 return false; 355 356 if (sdata->vif.type == NL80211_IFTYPE_STATION && 357 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL | 358 IEEE80211_STA_CONNECTION_POLL)) 359 return false; 360 361 return true; 362 } 363 364 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 365 { 366 lockdep_assert_held(&local->mtx); 367 368 if (!local->scan_req || local->scanning) 369 return; 370 371 if (!ieee80211_can_scan(local, 372 rcu_dereference_protected( 373 local->scan_sdata, 374 lockdep_is_held(&local->mtx)))) 375 return; 376 377 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 378 round_jiffies_relative(0)); 379 } 380 381 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 382 unsigned long *next_delay) 383 { 384 int i; 385 struct ieee80211_sub_if_data *sdata; 386 enum ieee80211_band band = local->hw.conf.chandef.chan->band; 387 u32 tx_flags; 388 389 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 390 if (local->scan_req->no_cck) 391 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 392 393 sdata = rcu_dereference_protected(local->scan_sdata, 394 lockdep_is_held(&local->mtx)); 395 396 for (i = 0; i < local->scan_req->n_ssids; i++) 397 ieee80211_send_probe_req( 398 sdata, NULL, 399 local->scan_req->ssids[i].ssid, 400 local->scan_req->ssids[i].ssid_len, 401 local->scan_req->ie, local->scan_req->ie_len, 402 local->scan_req->rates[band], false, 403 tx_flags, local->hw.conf.chandef.chan, true); 404 405 /* 406 * After sending probe requests, wait for probe responses 407 * on the channel. 408 */ 409 *next_delay = IEEE80211_CHANNEL_TIME; 410 local->next_scan_state = SCAN_DECISION; 411 } 412 413 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 414 struct cfg80211_scan_request *req) 415 { 416 struct ieee80211_local *local = sdata->local; 417 int rc; 418 419 lockdep_assert_held(&local->mtx); 420 421 if (local->scan_req) 422 return -EBUSY; 423 424 if (!ieee80211_can_scan(local, sdata)) { 425 /* wait for the work to finish/time out */ 426 local->scan_req = req; 427 rcu_assign_pointer(local->scan_sdata, sdata); 428 return 0; 429 } 430 431 if (local->ops->hw_scan) { 432 u8 *ies; 433 434 local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN + 435 local->scan_ies_len + 436 req->ie_len; 437 local->hw_scan_req = kmalloc( 438 sizeof(*local->hw_scan_req) + 439 req->n_channels * sizeof(req->channels[0]) + 440 local->hw_scan_ies_bufsize, GFP_KERNEL); 441 if (!local->hw_scan_req) 442 return -ENOMEM; 443 444 local->hw_scan_req->ssids = req->ssids; 445 local->hw_scan_req->n_ssids = req->n_ssids; 446 ies = (u8 *)local->hw_scan_req + 447 sizeof(*local->hw_scan_req) + 448 req->n_channels * sizeof(req->channels[0]); 449 local->hw_scan_req->ie = ies; 450 local->hw_scan_req->flags = req->flags; 451 452 local->hw_scan_band = 0; 453 454 /* 455 * After allocating local->hw_scan_req, we must 456 * go through until ieee80211_prep_hw_scan(), so 457 * anything that might be changed here and leave 458 * this function early must not go after this 459 * allocation. 460 */ 461 } 462 463 local->scan_req = req; 464 rcu_assign_pointer(local->scan_sdata, sdata); 465 466 if (local->ops->hw_scan) { 467 __set_bit(SCAN_HW_SCANNING, &local->scanning); 468 } else if ((req->n_channels == 1) && 469 (req->channels[0] == local->_oper_chandef.chan)) { 470 /* 471 * If we are scanning only on the operating channel 472 * then we do not need to stop normal activities 473 */ 474 unsigned long next_delay; 475 476 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 477 478 ieee80211_recalc_idle(local); 479 480 /* Notify driver scan is starting, keep order of operations 481 * same as normal software scan, in case that matters. */ 482 drv_sw_scan_start(local); 483 484 ieee80211_configure_filter(local); /* accept probe-responses */ 485 486 /* We need to ensure power level is at max for scanning. */ 487 ieee80211_hw_config(local, 0); 488 489 if ((req->channels[0]->flags & 490 IEEE80211_CHAN_PASSIVE_SCAN) || 491 !local->scan_req->n_ssids) { 492 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 493 } else { 494 ieee80211_scan_state_send_probe(local, &next_delay); 495 next_delay = IEEE80211_CHANNEL_TIME; 496 } 497 498 /* Now, just wait a bit and we are all done! */ 499 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 500 next_delay); 501 return 0; 502 } else { 503 /* Do normal software scan */ 504 __set_bit(SCAN_SW_SCANNING, &local->scanning); 505 } 506 507 ieee80211_recalc_idle(local); 508 509 if (local->ops->hw_scan) { 510 WARN_ON(!ieee80211_prep_hw_scan(local)); 511 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 512 } else 513 rc = ieee80211_start_sw_scan(local); 514 515 if (rc) { 516 kfree(local->hw_scan_req); 517 local->hw_scan_req = NULL; 518 local->scanning = 0; 519 520 ieee80211_recalc_idle(local); 521 522 local->scan_req = NULL; 523 rcu_assign_pointer(local->scan_sdata, NULL); 524 } 525 526 return rc; 527 } 528 529 static unsigned long 530 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 531 { 532 /* 533 * TODO: channel switching also consumes quite some time, 534 * add that delay as well to get a better estimation 535 */ 536 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 537 return IEEE80211_PASSIVE_CHANNEL_TIME; 538 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 539 } 540 541 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 542 unsigned long *next_delay) 543 { 544 bool associated = false; 545 bool tx_empty = true; 546 bool bad_latency; 547 struct ieee80211_sub_if_data *sdata; 548 struct ieee80211_channel *next_chan; 549 enum mac80211_scan_state next_scan_state; 550 551 /* 552 * check if at least one STA interface is associated, 553 * check if at least one STA interface has pending tx frames 554 * and grab the lowest used beacon interval 555 */ 556 mutex_lock(&local->iflist_mtx); 557 list_for_each_entry(sdata, &local->interfaces, list) { 558 if (!ieee80211_sdata_running(sdata)) 559 continue; 560 561 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 562 if (sdata->u.mgd.associated) { 563 associated = true; 564 565 if (!qdisc_all_tx_empty(sdata->dev)) { 566 tx_empty = false; 567 break; 568 } 569 } 570 } 571 } 572 mutex_unlock(&local->iflist_mtx); 573 574 next_chan = local->scan_req->channels[local->scan_channel_idx]; 575 576 /* 577 * we're currently scanning a different channel, let's 578 * see if we can scan another channel without interfering 579 * with the current traffic situation. 580 * 581 * Keep good latency, do not stay off-channel more than 125 ms. 582 */ 583 584 bad_latency = time_after(jiffies + 585 ieee80211_scan_get_channel_time(next_chan), 586 local->leave_oper_channel_time + HZ / 8); 587 588 if (associated && !tx_empty) { 589 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 590 next_scan_state = SCAN_ABORT; 591 else 592 next_scan_state = SCAN_SUSPEND; 593 } else if (associated && bad_latency) { 594 next_scan_state = SCAN_SUSPEND; 595 } else { 596 next_scan_state = SCAN_SET_CHANNEL; 597 } 598 599 local->next_scan_state = next_scan_state; 600 601 *next_delay = 0; 602 } 603 604 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 605 unsigned long *next_delay) 606 { 607 int skip; 608 struct ieee80211_channel *chan; 609 610 skip = 0; 611 chan = local->scan_req->channels[local->scan_channel_idx]; 612 613 local->scan_channel = chan; 614 615 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 616 skip = 1; 617 618 /* advance state machine to next channel/band */ 619 local->scan_channel_idx++; 620 621 if (skip) { 622 /* if we skip this channel return to the decision state */ 623 local->next_scan_state = SCAN_DECISION; 624 return; 625 } 626 627 /* 628 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 629 * (which unfortunately doesn't say _why_ step a) is done, 630 * but it waits for the probe delay or until a frame is 631 * received - and the received frame would update the NAV). 632 * For now, we do not support waiting until a frame is 633 * received. 634 * 635 * In any case, it is not necessary for a passive scan. 636 */ 637 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 638 !local->scan_req->n_ssids) { 639 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 640 local->next_scan_state = SCAN_DECISION; 641 return; 642 } 643 644 /* active scan, send probes */ 645 *next_delay = IEEE80211_PROBE_DELAY; 646 local->next_scan_state = SCAN_SEND_PROBE; 647 } 648 649 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 650 unsigned long *next_delay) 651 { 652 /* switch back to the operating channel */ 653 local->scan_channel = NULL; 654 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 655 656 /* disable PS */ 657 ieee80211_offchannel_return(local); 658 659 *next_delay = HZ / 5; 660 /* afterwards, resume scan & go to next channel */ 661 local->next_scan_state = SCAN_RESUME; 662 } 663 664 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 665 unsigned long *next_delay) 666 { 667 ieee80211_offchannel_stop_vifs(local); 668 669 if (local->ops->flush) { 670 ieee80211_flush_queues(local, NULL); 671 *next_delay = 0; 672 } else 673 *next_delay = HZ / 10; 674 675 /* remember when we left the operating channel */ 676 local->leave_oper_channel_time = jiffies; 677 678 /* advance to the next channel to be scanned */ 679 local->next_scan_state = SCAN_SET_CHANNEL; 680 } 681 682 void ieee80211_scan_work(struct work_struct *work) 683 { 684 struct ieee80211_local *local = 685 container_of(work, struct ieee80211_local, scan_work.work); 686 struct ieee80211_sub_if_data *sdata; 687 unsigned long next_delay = 0; 688 bool aborted, hw_scan; 689 690 mutex_lock(&local->mtx); 691 692 sdata = rcu_dereference_protected(local->scan_sdata, 693 lockdep_is_held(&local->mtx)); 694 695 /* When scanning on-channel, the first-callback means completed. */ 696 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 697 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 698 goto out_complete; 699 } 700 701 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 702 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 703 goto out_complete; 704 } 705 706 if (!sdata || !local->scan_req) 707 goto out; 708 709 if (local->scan_req && !local->scanning) { 710 struct cfg80211_scan_request *req = local->scan_req; 711 int rc; 712 713 local->scan_req = NULL; 714 rcu_assign_pointer(local->scan_sdata, NULL); 715 716 rc = __ieee80211_start_scan(sdata, req); 717 if (rc) { 718 /* need to complete scan in cfg80211 */ 719 local->scan_req = req; 720 aborted = true; 721 goto out_complete; 722 } else 723 goto out; 724 } 725 726 /* 727 * Avoid re-scheduling when the sdata is going away. 728 */ 729 if (!ieee80211_sdata_running(sdata)) { 730 aborted = true; 731 goto out_complete; 732 } 733 734 /* 735 * as long as no delay is required advance immediately 736 * without scheduling a new work 737 */ 738 do { 739 if (!ieee80211_sdata_running(sdata)) { 740 aborted = true; 741 goto out_complete; 742 } 743 744 switch (local->next_scan_state) { 745 case SCAN_DECISION: 746 /* if no more bands/channels left, complete scan */ 747 if (local->scan_channel_idx >= local->scan_req->n_channels) { 748 aborted = false; 749 goto out_complete; 750 } 751 ieee80211_scan_state_decision(local, &next_delay); 752 break; 753 case SCAN_SET_CHANNEL: 754 ieee80211_scan_state_set_channel(local, &next_delay); 755 break; 756 case SCAN_SEND_PROBE: 757 ieee80211_scan_state_send_probe(local, &next_delay); 758 break; 759 case SCAN_SUSPEND: 760 ieee80211_scan_state_suspend(local, &next_delay); 761 break; 762 case SCAN_RESUME: 763 ieee80211_scan_state_resume(local, &next_delay); 764 break; 765 case SCAN_ABORT: 766 aborted = true; 767 goto out_complete; 768 } 769 } while (next_delay == 0); 770 771 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 772 goto out; 773 774 out_complete: 775 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 776 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 777 out: 778 mutex_unlock(&local->mtx); 779 } 780 781 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 782 struct cfg80211_scan_request *req) 783 { 784 int res; 785 786 mutex_lock(&sdata->local->mtx); 787 res = __ieee80211_start_scan(sdata, req); 788 mutex_unlock(&sdata->local->mtx); 789 790 return res; 791 } 792 793 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 794 const u8 *ssid, u8 ssid_len, 795 struct ieee80211_channel *chan) 796 { 797 struct ieee80211_local *local = sdata->local; 798 int ret = -EBUSY; 799 enum ieee80211_band band; 800 801 mutex_lock(&local->mtx); 802 803 /* busy scanning */ 804 if (local->scan_req) 805 goto unlock; 806 807 /* fill internal scan request */ 808 if (!chan) { 809 int i, max_n; 810 int n_ch = 0; 811 812 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 813 if (!local->hw.wiphy->bands[band]) 814 continue; 815 816 max_n = local->hw.wiphy->bands[band]->n_channels; 817 for (i = 0; i < max_n; i++) { 818 struct ieee80211_channel *tmp_ch = 819 &local->hw.wiphy->bands[band]->channels[i]; 820 821 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS | 822 IEEE80211_CHAN_DISABLED)) 823 continue; 824 825 local->int_scan_req->channels[n_ch] = tmp_ch; 826 n_ch++; 827 } 828 } 829 830 if (WARN_ON_ONCE(n_ch == 0)) 831 goto unlock; 832 833 local->int_scan_req->n_channels = n_ch; 834 } else { 835 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS | 836 IEEE80211_CHAN_DISABLED))) 837 goto unlock; 838 839 local->int_scan_req->channels[0] = chan; 840 local->int_scan_req->n_channels = 1; 841 } 842 843 local->int_scan_req->ssids = &local->scan_ssid; 844 local->int_scan_req->n_ssids = 1; 845 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 846 local->int_scan_req->ssids[0].ssid_len = ssid_len; 847 848 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 849 unlock: 850 mutex_unlock(&local->mtx); 851 return ret; 852 } 853 854 /* 855 * Only call this function when a scan can't be queued -- under RTNL. 856 */ 857 void ieee80211_scan_cancel(struct ieee80211_local *local) 858 { 859 /* 860 * We are canceling software scan, or deferred scan that was not 861 * yet really started (see __ieee80211_start_scan ). 862 * 863 * Regarding hardware scan: 864 * - we can not call __ieee80211_scan_completed() as when 865 * SCAN_HW_SCANNING bit is set this function change 866 * local->hw_scan_req to operate on 5G band, what race with 867 * driver which can use local->hw_scan_req 868 * 869 * - we can not cancel scan_work since driver can schedule it 870 * by ieee80211_scan_completed(..., true) to finish scan 871 * 872 * Hence we only call the cancel_hw_scan() callback, but the low-level 873 * driver is still responsible for calling ieee80211_scan_completed() 874 * after the scan was completed/aborted. 875 */ 876 877 mutex_lock(&local->mtx); 878 if (!local->scan_req) 879 goto out; 880 881 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 882 if (local->ops->cancel_hw_scan) 883 drv_cancel_hw_scan(local, 884 rcu_dereference_protected(local->scan_sdata, 885 lockdep_is_held(&local->mtx))); 886 goto out; 887 } 888 889 /* 890 * If the work is currently running, it must be blocked on 891 * the mutex, but we'll set scan_sdata = NULL and it'll 892 * simply exit once it acquires the mutex. 893 */ 894 cancel_delayed_work(&local->scan_work); 895 /* and clean up */ 896 __ieee80211_scan_completed(&local->hw, true, false); 897 out: 898 mutex_unlock(&local->mtx); 899 } 900 901 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 902 struct cfg80211_sched_scan_request *req) 903 { 904 struct ieee80211_local *local = sdata->local; 905 struct ieee80211_sched_scan_ies sched_scan_ies = {}; 906 int ret, i, iebufsz; 907 908 iebufsz = 2 + IEEE80211_MAX_SSID_LEN + 909 local->scan_ies_len + req->ie_len; 910 911 mutex_lock(&local->mtx); 912 913 if (rcu_access_pointer(local->sched_scan_sdata)) { 914 ret = -EBUSY; 915 goto out; 916 } 917 918 if (!local->ops->sched_scan_start) { 919 ret = -ENOTSUPP; 920 goto out; 921 } 922 923 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 924 if (!local->hw.wiphy->bands[i]) 925 continue; 926 927 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL); 928 if (!sched_scan_ies.ie[i]) { 929 ret = -ENOMEM; 930 goto out_free; 931 } 932 933 sched_scan_ies.len[i] = 934 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i], 935 iebufsz, req->ie, req->ie_len, 936 i, (u32) -1, 0); 937 } 938 939 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 940 if (ret == 0) 941 rcu_assign_pointer(local->sched_scan_sdata, sdata); 942 943 out_free: 944 while (i > 0) 945 kfree(sched_scan_ies.ie[--i]); 946 out: 947 mutex_unlock(&local->mtx); 948 return ret; 949 } 950 951 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 952 { 953 struct ieee80211_local *local = sdata->local; 954 int ret = 0; 955 956 mutex_lock(&local->mtx); 957 958 if (!local->ops->sched_scan_stop) { 959 ret = -ENOTSUPP; 960 goto out; 961 } 962 963 if (rcu_access_pointer(local->sched_scan_sdata)) 964 drv_sched_scan_stop(local, sdata); 965 966 out: 967 mutex_unlock(&local->mtx); 968 969 return ret; 970 } 971 972 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 973 { 974 struct ieee80211_local *local = hw_to_local(hw); 975 976 trace_api_sched_scan_results(local); 977 978 cfg80211_sched_scan_results(hw->wiphy); 979 } 980 EXPORT_SYMBOL(ieee80211_sched_scan_results); 981 982 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 983 { 984 struct ieee80211_local *local = 985 container_of(work, struct ieee80211_local, 986 sched_scan_stopped_work); 987 988 mutex_lock(&local->mtx); 989 990 if (!rcu_access_pointer(local->sched_scan_sdata)) { 991 mutex_unlock(&local->mtx); 992 return; 993 } 994 995 rcu_assign_pointer(local->sched_scan_sdata, NULL); 996 997 mutex_unlock(&local->mtx); 998 999 cfg80211_sched_scan_stopped(local->hw.wiphy); 1000 } 1001 1002 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1003 { 1004 struct ieee80211_local *local = hw_to_local(hw); 1005 1006 trace_api_sched_scan_stopped(local); 1007 1008 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 1009 } 1010 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1011