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->erp_info_len >= 1 && 102 (!elems->parse_error || 103 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 104 bss->erp_value = elems->erp_info[0]; 105 bss->has_erp_value = true; 106 if (!elems->parse_error) 107 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 108 } 109 110 /* replace old supported rates if we get new values */ 111 if (!elems->parse_error || 112 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 113 srlen = 0; 114 if (elems->supp_rates) { 115 clen = IEEE80211_MAX_SUPP_RATES; 116 if (clen > elems->supp_rates_len) 117 clen = elems->supp_rates_len; 118 memcpy(bss->supp_rates, elems->supp_rates, clen); 119 srlen += clen; 120 } 121 if (elems->ext_supp_rates) { 122 clen = IEEE80211_MAX_SUPP_RATES - srlen; 123 if (clen > elems->ext_supp_rates_len) 124 clen = elems->ext_supp_rates_len; 125 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 126 clen); 127 srlen += clen; 128 } 129 if (srlen) { 130 bss->supp_rates_len = srlen; 131 if (!elems->parse_error) 132 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 133 } 134 } 135 136 if (!elems->parse_error || 137 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 138 bss->wmm_used = elems->wmm_param || elems->wmm_info; 139 bss->uapsd_supported = is_uapsd_supported(elems); 140 if (!elems->parse_error) 141 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 142 } 143 144 return bss; 145 } 146 147 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 148 { 149 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 150 struct ieee80211_sub_if_data *sdata1, *sdata2; 151 struct ieee80211_mgmt *mgmt = (void *)skb->data; 152 struct ieee80211_bss *bss; 153 u8 *elements; 154 struct ieee80211_channel *channel; 155 size_t baselen; 156 bool beacon; 157 struct ieee802_11_elems elems; 158 159 if (skb->len < 24 || 160 (!ieee80211_is_probe_resp(mgmt->frame_control) && 161 !ieee80211_is_beacon(mgmt->frame_control))) 162 return; 163 164 sdata1 = rcu_dereference(local->scan_sdata); 165 sdata2 = rcu_dereference(local->sched_scan_sdata); 166 167 if (likely(!sdata1 && !sdata2)) 168 return; 169 170 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 171 /* ignore ProbeResp to foreign address */ 172 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) && 173 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr))) 174 return; 175 176 elements = mgmt->u.probe_resp.variable; 177 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 178 beacon = false; 179 } else { 180 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 181 elements = mgmt->u.beacon.variable; 182 beacon = true; 183 } 184 185 if (baselen > skb->len) 186 return; 187 188 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 189 190 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 191 192 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 193 return; 194 195 bss = ieee80211_bss_info_update(local, rx_status, 196 mgmt, skb->len, &elems, 197 channel); 198 if (bss) 199 ieee80211_rx_bss_put(local, bss); 200 } 201 202 /* return false if no more work */ 203 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 204 { 205 struct cfg80211_scan_request *req = local->scan_req; 206 enum ieee80211_band band; 207 int i, ielen, n_chans; 208 209 do { 210 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 211 return false; 212 213 band = local->hw_scan_band; 214 n_chans = 0; 215 for (i = 0; i < req->n_channels; i++) { 216 if (req->channels[i]->band == band) { 217 local->hw_scan_req->channels[n_chans] = 218 req->channels[i]; 219 n_chans++; 220 } 221 } 222 223 local->hw_scan_band++; 224 } while (!n_chans); 225 226 local->hw_scan_req->n_channels = n_chans; 227 228 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 229 local->hw_scan_ies_bufsize, 230 req->ie, req->ie_len, band, 231 req->rates[band], 0); 232 local->hw_scan_req->ie_len = ielen; 233 local->hw_scan_req->no_cck = req->no_cck; 234 235 return true; 236 } 237 238 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 239 bool was_hw_scan) 240 { 241 struct ieee80211_local *local = hw_to_local(hw); 242 243 lockdep_assert_held(&local->mtx); 244 245 /* 246 * It's ok to abort a not-yet-running scan (that 247 * we have one at all will be verified by checking 248 * local->scan_req next), but not to complete it 249 * successfully. 250 */ 251 if (WARN_ON(!local->scanning && !aborted)) 252 aborted = true; 253 254 if (WARN_ON(!local->scan_req)) 255 return; 256 257 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 258 int rc; 259 260 rc = drv_hw_scan(local, 261 rcu_dereference_protected(local->scan_sdata, 262 lockdep_is_held(&local->mtx)), 263 local->hw_scan_req); 264 265 if (rc == 0) 266 return; 267 } 268 269 kfree(local->hw_scan_req); 270 local->hw_scan_req = NULL; 271 272 if (local->scan_req != local->int_scan_req) 273 cfg80211_scan_done(local->scan_req, aborted); 274 local->scan_req = NULL; 275 rcu_assign_pointer(local->scan_sdata, NULL); 276 277 local->scanning = 0; 278 local->scan_channel = NULL; 279 280 /* Set power back to normal operating levels. */ 281 ieee80211_hw_config(local, 0); 282 283 if (!was_hw_scan) { 284 ieee80211_configure_filter(local); 285 drv_sw_scan_complete(local); 286 ieee80211_offchannel_return(local); 287 } 288 289 ieee80211_recalc_idle(local); 290 291 ieee80211_mlme_notify_scan_completed(local); 292 ieee80211_ibss_notify_scan_completed(local); 293 ieee80211_mesh_notify_scan_completed(local); 294 ieee80211_start_next_roc(local); 295 } 296 297 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 298 { 299 struct ieee80211_local *local = hw_to_local(hw); 300 301 trace_api_scan_completed(local, aborted); 302 303 set_bit(SCAN_COMPLETED, &local->scanning); 304 if (aborted) 305 set_bit(SCAN_ABORTED, &local->scanning); 306 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 307 } 308 EXPORT_SYMBOL(ieee80211_scan_completed); 309 310 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 311 { 312 /* Software scan is not supported in multi-channel cases */ 313 if (local->use_chanctx) 314 return -EOPNOTSUPP; 315 316 /* 317 * Hardware/driver doesn't support hw_scan, so use software 318 * scanning instead. First send a nullfunc frame with power save 319 * bit on so that AP will buffer the frames for us while we are not 320 * listening, then send probe requests to each channel and wait for 321 * the responses. After all channels are scanned, tune back to the 322 * original channel and send a nullfunc frame with power save bit 323 * off to trigger the AP to send us all the buffered frames. 324 * 325 * Note that while local->sw_scanning is true everything else but 326 * nullfunc frames and probe requests will be dropped in 327 * ieee80211_tx_h_check_assoc(). 328 */ 329 drv_sw_scan_start(local); 330 331 local->leave_oper_channel_time = jiffies; 332 local->next_scan_state = SCAN_DECISION; 333 local->scan_channel_idx = 0; 334 335 ieee80211_offchannel_stop_vifs(local); 336 337 /* ensure nullfunc is transmitted before leaving operating channel */ 338 drv_flush(local, false); 339 340 ieee80211_configure_filter(local); 341 342 /* We need to set power level at maximum rate for scanning. */ 343 ieee80211_hw_config(local, 0); 344 345 ieee80211_queue_delayed_work(&local->hw, 346 &local->scan_work, 0); 347 348 return 0; 349 } 350 351 static bool ieee80211_can_scan(struct ieee80211_local *local, 352 struct ieee80211_sub_if_data *sdata) 353 { 354 if (local->radar_detect_enabled) 355 return false; 356 357 if (!list_empty(&local->roc_list)) 358 return false; 359 360 if (sdata->vif.type == NL80211_IFTYPE_STATION && 361 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL | 362 IEEE80211_STA_CONNECTION_POLL)) 363 return false; 364 365 return true; 366 } 367 368 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 369 { 370 lockdep_assert_held(&local->mtx); 371 372 if (!local->scan_req || local->scanning) 373 return; 374 375 if (!ieee80211_can_scan(local, 376 rcu_dereference_protected( 377 local->scan_sdata, 378 lockdep_is_held(&local->mtx)))) 379 return; 380 381 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 382 round_jiffies_relative(0)); 383 } 384 385 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 386 unsigned long *next_delay) 387 { 388 int i; 389 struct ieee80211_sub_if_data *sdata; 390 enum ieee80211_band band = local->hw.conf.channel->band; 391 u32 tx_flags; 392 393 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 394 if (local->scan_req->no_cck) 395 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 396 397 sdata = rcu_dereference_protected(local->scan_sdata, 398 lockdep_is_held(&local->mtx)); 399 400 for (i = 0; i < local->scan_req->n_ssids; i++) 401 ieee80211_send_probe_req( 402 sdata, NULL, 403 local->scan_req->ssids[i].ssid, 404 local->scan_req->ssids[i].ssid_len, 405 local->scan_req->ie, local->scan_req->ie_len, 406 local->scan_req->rates[band], false, 407 tx_flags, local->hw.conf.channel, true); 408 409 /* 410 * After sending probe requests, wait for probe responses 411 * on the channel. 412 */ 413 *next_delay = IEEE80211_CHANNEL_TIME; 414 local->next_scan_state = SCAN_DECISION; 415 } 416 417 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 418 struct cfg80211_scan_request *req) 419 { 420 struct ieee80211_local *local = sdata->local; 421 int rc; 422 423 lockdep_assert_held(&local->mtx); 424 425 if (local->scan_req) 426 return -EBUSY; 427 428 if (!ieee80211_can_scan(local, sdata)) { 429 /* wait for the work to finish/time out */ 430 local->scan_req = req; 431 rcu_assign_pointer(local->scan_sdata, sdata); 432 return 0; 433 } 434 435 if (local->ops->hw_scan) { 436 u8 *ies; 437 438 local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN + 439 local->scan_ies_len + 440 req->ie_len; 441 local->hw_scan_req = kmalloc( 442 sizeof(*local->hw_scan_req) + 443 req->n_channels * sizeof(req->channels[0]) + 444 local->hw_scan_ies_bufsize, GFP_KERNEL); 445 if (!local->hw_scan_req) 446 return -ENOMEM; 447 448 local->hw_scan_req->ssids = req->ssids; 449 local->hw_scan_req->n_ssids = req->n_ssids; 450 ies = (u8 *)local->hw_scan_req + 451 sizeof(*local->hw_scan_req) + 452 req->n_channels * sizeof(req->channels[0]); 453 local->hw_scan_req->ie = ies; 454 local->hw_scan_req->flags = req->flags; 455 456 local->hw_scan_band = 0; 457 458 /* 459 * After allocating local->hw_scan_req, we must 460 * go through until ieee80211_prep_hw_scan(), so 461 * anything that might be changed here and leave 462 * this function early must not go after this 463 * allocation. 464 */ 465 } 466 467 local->scan_req = req; 468 rcu_assign_pointer(local->scan_sdata, sdata); 469 470 if (local->ops->hw_scan) { 471 __set_bit(SCAN_HW_SCANNING, &local->scanning); 472 } else if ((req->n_channels == 1) && 473 (req->channels[0] == local->_oper_channel)) { 474 /* 475 * If we are scanning only on the operating channel 476 * then we do not need to stop normal activities 477 */ 478 unsigned long next_delay; 479 480 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 481 482 ieee80211_recalc_idle(local); 483 484 /* Notify driver scan is starting, keep order of operations 485 * same as normal software scan, in case that matters. */ 486 drv_sw_scan_start(local); 487 488 ieee80211_configure_filter(local); /* accept probe-responses */ 489 490 /* We need to ensure power level is at max for scanning. */ 491 ieee80211_hw_config(local, 0); 492 493 if ((req->channels[0]->flags & 494 IEEE80211_CHAN_PASSIVE_SCAN) || 495 !local->scan_req->n_ssids) { 496 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 497 } else { 498 ieee80211_scan_state_send_probe(local, &next_delay); 499 next_delay = IEEE80211_CHANNEL_TIME; 500 } 501 502 /* Now, just wait a bit and we are all done! */ 503 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 504 next_delay); 505 return 0; 506 } else { 507 /* Do normal software scan */ 508 __set_bit(SCAN_SW_SCANNING, &local->scanning); 509 } 510 511 ieee80211_recalc_idle(local); 512 513 if (local->ops->hw_scan) { 514 WARN_ON(!ieee80211_prep_hw_scan(local)); 515 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 516 } else 517 rc = ieee80211_start_sw_scan(local); 518 519 if (rc) { 520 kfree(local->hw_scan_req); 521 local->hw_scan_req = NULL; 522 local->scanning = 0; 523 524 ieee80211_recalc_idle(local); 525 526 local->scan_req = NULL; 527 rcu_assign_pointer(local->scan_sdata, NULL); 528 } 529 530 return rc; 531 } 532 533 static unsigned long 534 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 535 { 536 /* 537 * TODO: channel switching also consumes quite some time, 538 * add that delay as well to get a better estimation 539 */ 540 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 541 return IEEE80211_PASSIVE_CHANNEL_TIME; 542 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 543 } 544 545 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 546 unsigned long *next_delay) 547 { 548 bool associated = false; 549 bool tx_empty = true; 550 bool bad_latency; 551 struct ieee80211_sub_if_data *sdata; 552 struct ieee80211_channel *next_chan; 553 enum mac80211_scan_state next_scan_state; 554 555 /* 556 * check if at least one STA interface is associated, 557 * check if at least one STA interface has pending tx frames 558 * and grab the lowest used beacon interval 559 */ 560 mutex_lock(&local->iflist_mtx); 561 list_for_each_entry(sdata, &local->interfaces, list) { 562 if (!ieee80211_sdata_running(sdata)) 563 continue; 564 565 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 566 if (sdata->u.mgd.associated) { 567 associated = true; 568 569 if (!qdisc_all_tx_empty(sdata->dev)) { 570 tx_empty = false; 571 break; 572 } 573 } 574 } 575 } 576 mutex_unlock(&local->iflist_mtx); 577 578 next_chan = local->scan_req->channels[local->scan_channel_idx]; 579 580 /* 581 * we're currently scanning a different channel, let's 582 * see if we can scan another channel without interfering 583 * with the current traffic situation. 584 * 585 * Keep good latency, do not stay off-channel more than 125 ms. 586 */ 587 588 bad_latency = time_after(jiffies + 589 ieee80211_scan_get_channel_time(next_chan), 590 local->leave_oper_channel_time + HZ / 8); 591 592 if (associated && !tx_empty) { 593 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 594 next_scan_state = SCAN_ABORT; 595 else 596 next_scan_state = SCAN_SUSPEND; 597 } else if (associated && bad_latency) { 598 next_scan_state = SCAN_SUSPEND; 599 } else { 600 next_scan_state = SCAN_SET_CHANNEL; 601 } 602 603 local->next_scan_state = next_scan_state; 604 605 *next_delay = 0; 606 } 607 608 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 609 unsigned long *next_delay) 610 { 611 int skip; 612 struct ieee80211_channel *chan; 613 614 skip = 0; 615 chan = local->scan_req->channels[local->scan_channel_idx]; 616 617 local->scan_channel = chan; 618 619 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 620 skip = 1; 621 622 /* advance state machine to next channel/band */ 623 local->scan_channel_idx++; 624 625 if (skip) { 626 /* if we skip this channel return to the decision state */ 627 local->next_scan_state = SCAN_DECISION; 628 return; 629 } 630 631 /* 632 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 633 * (which unfortunately doesn't say _why_ step a) is done, 634 * but it waits for the probe delay or until a frame is 635 * received - and the received frame would update the NAV). 636 * For now, we do not support waiting until a frame is 637 * received. 638 * 639 * In any case, it is not necessary for a passive scan. 640 */ 641 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 642 !local->scan_req->n_ssids) { 643 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 644 local->next_scan_state = SCAN_DECISION; 645 return; 646 } 647 648 /* active scan, send probes */ 649 *next_delay = IEEE80211_PROBE_DELAY; 650 local->next_scan_state = SCAN_SEND_PROBE; 651 } 652 653 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 654 unsigned long *next_delay) 655 { 656 /* switch back to the operating channel */ 657 local->scan_channel = NULL; 658 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 659 660 /* disable PS */ 661 ieee80211_offchannel_return(local); 662 663 *next_delay = HZ / 5; 664 /* afterwards, resume scan & go to next channel */ 665 local->next_scan_state = SCAN_RESUME; 666 } 667 668 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 669 unsigned long *next_delay) 670 { 671 ieee80211_offchannel_stop_vifs(local); 672 673 if (local->ops->flush) { 674 drv_flush(local, false); 675 *next_delay = 0; 676 } else 677 *next_delay = HZ / 10; 678 679 /* remember when we left the operating channel */ 680 local->leave_oper_channel_time = jiffies; 681 682 /* advance to the next channel to be scanned */ 683 local->next_scan_state = SCAN_SET_CHANNEL; 684 } 685 686 void 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; 691 unsigned long next_delay = 0; 692 bool aborted, hw_scan; 693 694 mutex_lock(&local->mtx); 695 696 sdata = rcu_dereference_protected(local->scan_sdata, 697 lockdep_is_held(&local->mtx)); 698 699 /* When scanning on-channel, the first-callback means completed. */ 700 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 701 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 702 goto out_complete; 703 } 704 705 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 706 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 707 goto out_complete; 708 } 709 710 if (!sdata || !local->scan_req) 711 goto out; 712 713 if (local->scan_req && !local->scanning) { 714 struct cfg80211_scan_request *req = local->scan_req; 715 int rc; 716 717 local->scan_req = NULL; 718 rcu_assign_pointer(local->scan_sdata, NULL); 719 720 rc = __ieee80211_start_scan(sdata, req); 721 if (rc) { 722 /* need to complete scan in cfg80211 */ 723 local->scan_req = req; 724 aborted = true; 725 goto out_complete; 726 } else 727 goto out; 728 } 729 730 /* 731 * Avoid re-scheduling when the sdata is going away. 732 */ 733 if (!ieee80211_sdata_running(sdata)) { 734 aborted = true; 735 goto out_complete; 736 } 737 738 /* 739 * as long as no delay is required advance immediately 740 * without scheduling a new work 741 */ 742 do { 743 if (!ieee80211_sdata_running(sdata)) { 744 aborted = true; 745 goto out_complete; 746 } 747 748 switch (local->next_scan_state) { 749 case SCAN_DECISION: 750 /* if no more bands/channels left, complete scan */ 751 if (local->scan_channel_idx >= local->scan_req->n_channels) { 752 aborted = false; 753 goto out_complete; 754 } 755 ieee80211_scan_state_decision(local, &next_delay); 756 break; 757 case SCAN_SET_CHANNEL: 758 ieee80211_scan_state_set_channel(local, &next_delay); 759 break; 760 case SCAN_SEND_PROBE: 761 ieee80211_scan_state_send_probe(local, &next_delay); 762 break; 763 case SCAN_SUSPEND: 764 ieee80211_scan_state_suspend(local, &next_delay); 765 break; 766 case SCAN_RESUME: 767 ieee80211_scan_state_resume(local, &next_delay); 768 break; 769 case SCAN_ABORT: 770 aborted = true; 771 goto out_complete; 772 } 773 } while (next_delay == 0); 774 775 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 776 goto out; 777 778 out_complete: 779 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 780 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 781 out: 782 mutex_unlock(&local->mtx); 783 } 784 785 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 786 struct cfg80211_scan_request *req) 787 { 788 int res; 789 790 mutex_lock(&sdata->local->mtx); 791 res = __ieee80211_start_scan(sdata, req); 792 mutex_unlock(&sdata->local->mtx); 793 794 return res; 795 } 796 797 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 798 const u8 *ssid, u8 ssid_len, 799 struct ieee80211_channel *chan) 800 { 801 struct ieee80211_local *local = sdata->local; 802 int ret = -EBUSY; 803 enum ieee80211_band band; 804 805 mutex_lock(&local->mtx); 806 807 /* busy scanning */ 808 if (local->scan_req) 809 goto unlock; 810 811 /* fill internal scan request */ 812 if (!chan) { 813 int i, max_n; 814 int n_ch = 0; 815 816 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 817 if (!local->hw.wiphy->bands[band]) 818 continue; 819 820 max_n = local->hw.wiphy->bands[band]->n_channels; 821 for (i = 0; i < max_n; i++) { 822 struct ieee80211_channel *tmp_ch = 823 &local->hw.wiphy->bands[band]->channels[i]; 824 825 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS | 826 IEEE80211_CHAN_DISABLED)) 827 continue; 828 829 local->int_scan_req->channels[n_ch] = tmp_ch; 830 n_ch++; 831 } 832 } 833 834 if (WARN_ON_ONCE(n_ch == 0)) 835 goto unlock; 836 837 local->int_scan_req->n_channels = n_ch; 838 } else { 839 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS | 840 IEEE80211_CHAN_DISABLED))) 841 goto unlock; 842 843 local->int_scan_req->channels[0] = chan; 844 local->int_scan_req->n_channels = 1; 845 } 846 847 local->int_scan_req->ssids = &local->scan_ssid; 848 local->int_scan_req->n_ssids = 1; 849 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 850 local->int_scan_req->ssids[0].ssid_len = ssid_len; 851 852 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 853 unlock: 854 mutex_unlock(&local->mtx); 855 return ret; 856 } 857 858 /* 859 * Only call this function when a scan can't be queued -- under RTNL. 860 */ 861 void ieee80211_scan_cancel(struct ieee80211_local *local) 862 { 863 /* 864 * We are canceling software scan, or deferred scan that was not 865 * yet really started (see __ieee80211_start_scan ). 866 * 867 * Regarding hardware scan: 868 * - we can not call __ieee80211_scan_completed() as when 869 * SCAN_HW_SCANNING bit is set this function change 870 * local->hw_scan_req to operate on 5G band, what race with 871 * driver which can use local->hw_scan_req 872 * 873 * - we can not cancel scan_work since driver can schedule it 874 * by ieee80211_scan_completed(..., true) to finish scan 875 * 876 * Hence we only call the cancel_hw_scan() callback, but the low-level 877 * driver is still responsible for calling ieee80211_scan_completed() 878 * after the scan was completed/aborted. 879 */ 880 881 mutex_lock(&local->mtx); 882 if (!local->scan_req) 883 goto out; 884 885 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 886 if (local->ops->cancel_hw_scan) 887 drv_cancel_hw_scan(local, 888 rcu_dereference_protected(local->scan_sdata, 889 lockdep_is_held(&local->mtx))); 890 goto out; 891 } 892 893 /* 894 * If the work is currently running, it must be blocked on 895 * the mutex, but we'll set scan_sdata = NULL and it'll 896 * simply exit once it acquires the mutex. 897 */ 898 cancel_delayed_work(&local->scan_work); 899 /* and clean up */ 900 __ieee80211_scan_completed(&local->hw, true, false); 901 out: 902 mutex_unlock(&local->mtx); 903 } 904 905 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 906 struct cfg80211_sched_scan_request *req) 907 { 908 struct ieee80211_local *local = sdata->local; 909 struct ieee80211_sched_scan_ies sched_scan_ies = {}; 910 int ret, i, iebufsz; 911 912 iebufsz = 2 + IEEE80211_MAX_SSID_LEN + 913 local->scan_ies_len + req->ie_len; 914 915 mutex_lock(&local->mtx); 916 917 if (rcu_access_pointer(local->sched_scan_sdata)) { 918 ret = -EBUSY; 919 goto out; 920 } 921 922 if (!local->ops->sched_scan_start) { 923 ret = -ENOTSUPP; 924 goto out; 925 } 926 927 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 928 if (!local->hw.wiphy->bands[i]) 929 continue; 930 931 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL); 932 if (!sched_scan_ies.ie[i]) { 933 ret = -ENOMEM; 934 goto out_free; 935 } 936 937 sched_scan_ies.len[i] = 938 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i], 939 iebufsz, req->ie, req->ie_len, 940 i, (u32) -1, 0); 941 } 942 943 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 944 if (ret == 0) 945 rcu_assign_pointer(local->sched_scan_sdata, sdata); 946 947 out_free: 948 while (i > 0) 949 kfree(sched_scan_ies.ie[--i]); 950 out: 951 mutex_unlock(&local->mtx); 952 return ret; 953 } 954 955 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 956 { 957 struct ieee80211_local *local = sdata->local; 958 int ret = 0; 959 960 mutex_lock(&local->mtx); 961 962 if (!local->ops->sched_scan_stop) { 963 ret = -ENOTSUPP; 964 goto out; 965 } 966 967 if (rcu_access_pointer(local->sched_scan_sdata)) 968 drv_sched_scan_stop(local, sdata); 969 970 out: 971 mutex_unlock(&local->mtx); 972 973 return ret; 974 } 975 976 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 977 { 978 struct ieee80211_local *local = hw_to_local(hw); 979 980 trace_api_sched_scan_results(local); 981 982 cfg80211_sched_scan_results(hw->wiphy); 983 } 984 EXPORT_SYMBOL(ieee80211_sched_scan_results); 985 986 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 987 { 988 struct ieee80211_local *local = 989 container_of(work, struct ieee80211_local, 990 sched_scan_stopped_work); 991 992 mutex_lock(&local->mtx); 993 994 if (!rcu_access_pointer(local->sched_scan_sdata)) { 995 mutex_unlock(&local->mtx); 996 return; 997 } 998 999 rcu_assign_pointer(local->sched_scan_sdata, NULL); 1000 1001 mutex_unlock(&local->mtx); 1002 1003 cfg80211_sched_scan_stopped(local->hw.wiphy); 1004 } 1005 1006 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1007 { 1008 struct ieee80211_local *local = hw_to_local(hw); 1009 1010 trace_api_sched_scan_stopped(local); 1011 1012 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 1013 } 1014 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1015