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 if (beacon) { 144 struct ieee80211_supported_band *sband = 145 local->hw.wiphy->bands[rx_status->band]; 146 if (!(rx_status->flag & RX_FLAG_HT) && 147 !(rx_status->flag & RX_FLAG_VHT)) 148 bss->beacon_rate = 149 &sband->bitrates[rx_status->rate_idx]; 150 } 151 152 return bss; 153 } 154 155 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 156 { 157 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 158 struct ieee80211_sub_if_data *sdata1, *sdata2; 159 struct ieee80211_mgmt *mgmt = (void *)skb->data; 160 struct ieee80211_bss *bss; 161 u8 *elements; 162 struct ieee80211_channel *channel; 163 size_t baselen; 164 struct ieee802_11_elems elems; 165 166 if (skb->len < 24 || 167 (!ieee80211_is_probe_resp(mgmt->frame_control) && 168 !ieee80211_is_beacon(mgmt->frame_control))) 169 return; 170 171 sdata1 = rcu_dereference(local->scan_sdata); 172 sdata2 = rcu_dereference(local->sched_scan_sdata); 173 174 if (likely(!sdata1 && !sdata2)) 175 return; 176 177 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 178 /* ignore ProbeResp to foreign address */ 179 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) && 180 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr))) 181 return; 182 183 elements = mgmt->u.probe_resp.variable; 184 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 185 } else { 186 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 187 elements = mgmt->u.beacon.variable; 188 } 189 190 if (baselen > skb->len) 191 return; 192 193 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 194 195 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 196 197 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 198 return; 199 200 bss = ieee80211_bss_info_update(local, rx_status, 201 mgmt, skb->len, &elems, 202 channel); 203 if (bss) 204 ieee80211_rx_bss_put(local, bss); 205 } 206 207 /* return false if no more work */ 208 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 209 { 210 struct cfg80211_scan_request *req = local->scan_req; 211 enum ieee80211_band band; 212 int i, ielen, n_chans; 213 214 do { 215 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 216 return false; 217 218 band = local->hw_scan_band; 219 n_chans = 0; 220 for (i = 0; i < req->n_channels; i++) { 221 if (req->channels[i]->band == band) { 222 local->hw_scan_req->channels[n_chans] = 223 req->channels[i]; 224 n_chans++; 225 } 226 } 227 228 local->hw_scan_band++; 229 } while (!n_chans); 230 231 local->hw_scan_req->n_channels = n_chans; 232 233 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 234 local->hw_scan_ies_bufsize, 235 req->ie, req->ie_len, band, 236 req->rates[band], 0); 237 local->hw_scan_req->ie_len = ielen; 238 local->hw_scan_req->no_cck = req->no_cck; 239 240 return true; 241 } 242 243 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 244 bool was_hw_scan) 245 { 246 struct ieee80211_local *local = hw_to_local(hw); 247 248 lockdep_assert_held(&local->mtx); 249 250 /* 251 * It's ok to abort a not-yet-running scan (that 252 * we have one at all will be verified by checking 253 * local->scan_req next), but not to complete it 254 * successfully. 255 */ 256 if (WARN_ON(!local->scanning && !aborted)) 257 aborted = true; 258 259 if (WARN_ON(!local->scan_req)) 260 return; 261 262 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 263 int rc; 264 265 rc = drv_hw_scan(local, 266 rcu_dereference_protected(local->scan_sdata, 267 lockdep_is_held(&local->mtx)), 268 local->hw_scan_req); 269 270 if (rc == 0) 271 return; 272 } 273 274 kfree(local->hw_scan_req); 275 local->hw_scan_req = NULL; 276 277 if (local->scan_req != local->int_scan_req) 278 cfg80211_scan_done(local->scan_req, aborted); 279 local->scan_req = NULL; 280 rcu_assign_pointer(local->scan_sdata, NULL); 281 282 local->scanning = 0; 283 local->scan_channel = NULL; 284 285 /* Set power back to normal operating levels. */ 286 ieee80211_hw_config(local, 0); 287 288 if (!was_hw_scan) { 289 ieee80211_configure_filter(local); 290 drv_sw_scan_complete(local); 291 ieee80211_offchannel_return(local); 292 } 293 294 ieee80211_recalc_idle(local); 295 296 ieee80211_mlme_notify_scan_completed(local); 297 ieee80211_ibss_notify_scan_completed(local); 298 ieee80211_mesh_notify_scan_completed(local); 299 ieee80211_start_next_roc(local); 300 } 301 302 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 303 { 304 struct ieee80211_local *local = hw_to_local(hw); 305 306 trace_api_scan_completed(local, aborted); 307 308 set_bit(SCAN_COMPLETED, &local->scanning); 309 if (aborted) 310 set_bit(SCAN_ABORTED, &local->scanning); 311 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 312 } 313 EXPORT_SYMBOL(ieee80211_scan_completed); 314 315 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 316 { 317 /* Software scan is not supported in multi-channel cases */ 318 if (local->use_chanctx) 319 return -EOPNOTSUPP; 320 321 /* 322 * Hardware/driver doesn't support hw_scan, so use software 323 * scanning instead. First send a nullfunc frame with power save 324 * bit on so that AP will buffer the frames for us while we are not 325 * listening, then send probe requests to each channel and wait for 326 * the responses. After all channels are scanned, tune back to the 327 * original channel and send a nullfunc frame with power save bit 328 * off to trigger the AP to send us all the buffered frames. 329 * 330 * Note that while local->sw_scanning is true everything else but 331 * nullfunc frames and probe requests will be dropped in 332 * ieee80211_tx_h_check_assoc(). 333 */ 334 drv_sw_scan_start(local); 335 336 local->leave_oper_channel_time = jiffies; 337 local->next_scan_state = SCAN_DECISION; 338 local->scan_channel_idx = 0; 339 340 ieee80211_offchannel_stop_vifs(local); 341 342 /* ensure nullfunc is transmitted before leaving operating channel */ 343 ieee80211_flush_queues(local, NULL); 344 345 ieee80211_configure_filter(local); 346 347 /* We need to set power level at maximum rate for scanning. */ 348 ieee80211_hw_config(local, 0); 349 350 ieee80211_queue_delayed_work(&local->hw, 351 &local->scan_work, 0); 352 353 return 0; 354 } 355 356 static bool ieee80211_can_scan(struct ieee80211_local *local, 357 struct ieee80211_sub_if_data *sdata) 358 { 359 if (local->radar_detect_enabled) 360 return false; 361 362 if (!list_empty(&local->roc_list)) 363 return false; 364 365 if (sdata->vif.type == NL80211_IFTYPE_STATION && 366 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL | 367 IEEE80211_STA_CONNECTION_POLL)) 368 return false; 369 370 return true; 371 } 372 373 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 374 { 375 lockdep_assert_held(&local->mtx); 376 377 if (!local->scan_req || local->scanning) 378 return; 379 380 if (!ieee80211_can_scan(local, 381 rcu_dereference_protected( 382 local->scan_sdata, 383 lockdep_is_held(&local->mtx)))) 384 return; 385 386 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 387 round_jiffies_relative(0)); 388 } 389 390 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 391 unsigned long *next_delay) 392 { 393 int i; 394 struct ieee80211_sub_if_data *sdata; 395 enum ieee80211_band band = local->hw.conf.chandef.chan->band; 396 u32 tx_flags; 397 398 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 399 if (local->scan_req->no_cck) 400 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 401 402 sdata = rcu_dereference_protected(local->scan_sdata, 403 lockdep_is_held(&local->mtx)); 404 405 for (i = 0; i < local->scan_req->n_ssids; i++) 406 ieee80211_send_probe_req( 407 sdata, NULL, 408 local->scan_req->ssids[i].ssid, 409 local->scan_req->ssids[i].ssid_len, 410 local->scan_req->ie, local->scan_req->ie_len, 411 local->scan_req->rates[band], false, 412 tx_flags, local->hw.conf.chandef.chan, true); 413 414 /* 415 * After sending probe requests, wait for probe responses 416 * on the channel. 417 */ 418 *next_delay = IEEE80211_CHANNEL_TIME; 419 local->next_scan_state = SCAN_DECISION; 420 } 421 422 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 423 struct cfg80211_scan_request *req) 424 { 425 struct ieee80211_local *local = sdata->local; 426 int rc; 427 428 lockdep_assert_held(&local->mtx); 429 430 if (local->scan_req) 431 return -EBUSY; 432 433 if (!ieee80211_can_scan(local, sdata)) { 434 /* wait for the work to finish/time out */ 435 local->scan_req = req; 436 rcu_assign_pointer(local->scan_sdata, sdata); 437 return 0; 438 } 439 440 if (local->ops->hw_scan) { 441 u8 *ies; 442 443 local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN + 444 local->scan_ies_len + 445 req->ie_len; 446 local->hw_scan_req = kmalloc( 447 sizeof(*local->hw_scan_req) + 448 req->n_channels * sizeof(req->channels[0]) + 449 local->hw_scan_ies_bufsize, GFP_KERNEL); 450 if (!local->hw_scan_req) 451 return -ENOMEM; 452 453 local->hw_scan_req->ssids = req->ssids; 454 local->hw_scan_req->n_ssids = req->n_ssids; 455 ies = (u8 *)local->hw_scan_req + 456 sizeof(*local->hw_scan_req) + 457 req->n_channels * sizeof(req->channels[0]); 458 local->hw_scan_req->ie = ies; 459 local->hw_scan_req->flags = req->flags; 460 461 local->hw_scan_band = 0; 462 463 /* 464 * After allocating local->hw_scan_req, we must 465 * go through until ieee80211_prep_hw_scan(), so 466 * anything that might be changed here and leave 467 * this function early must not go after this 468 * allocation. 469 */ 470 } 471 472 local->scan_req = req; 473 rcu_assign_pointer(local->scan_sdata, sdata); 474 475 if (local->ops->hw_scan) { 476 __set_bit(SCAN_HW_SCANNING, &local->scanning); 477 } else if ((req->n_channels == 1) && 478 (req->channels[0] == local->_oper_chandef.chan)) { 479 /* 480 * If we are scanning only on the operating channel 481 * then we do not need to stop normal activities 482 */ 483 unsigned long next_delay; 484 485 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 486 487 ieee80211_recalc_idle(local); 488 489 /* Notify driver scan is starting, keep order of operations 490 * same as normal software scan, in case that matters. */ 491 drv_sw_scan_start(local); 492 493 ieee80211_configure_filter(local); /* accept probe-responses */ 494 495 /* We need to ensure power level is at max for scanning. */ 496 ieee80211_hw_config(local, 0); 497 498 if ((req->channels[0]->flags & 499 IEEE80211_CHAN_PASSIVE_SCAN) || 500 !local->scan_req->n_ssids) { 501 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 502 } else { 503 ieee80211_scan_state_send_probe(local, &next_delay); 504 next_delay = IEEE80211_CHANNEL_TIME; 505 } 506 507 /* Now, just wait a bit and we are all done! */ 508 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 509 next_delay); 510 return 0; 511 } else { 512 /* Do normal software scan */ 513 __set_bit(SCAN_SW_SCANNING, &local->scanning); 514 } 515 516 ieee80211_recalc_idle(local); 517 518 if (local->ops->hw_scan) { 519 WARN_ON(!ieee80211_prep_hw_scan(local)); 520 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 521 } else 522 rc = ieee80211_start_sw_scan(local); 523 524 if (rc) { 525 kfree(local->hw_scan_req); 526 local->hw_scan_req = NULL; 527 local->scanning = 0; 528 529 ieee80211_recalc_idle(local); 530 531 local->scan_req = NULL; 532 rcu_assign_pointer(local->scan_sdata, NULL); 533 } 534 535 return rc; 536 } 537 538 static unsigned long 539 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 540 { 541 /* 542 * TODO: channel switching also consumes quite some time, 543 * add that delay as well to get a better estimation 544 */ 545 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 546 return IEEE80211_PASSIVE_CHANNEL_TIME; 547 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 548 } 549 550 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 551 unsigned long *next_delay) 552 { 553 bool associated = false; 554 bool tx_empty = true; 555 bool bad_latency; 556 struct ieee80211_sub_if_data *sdata; 557 struct ieee80211_channel *next_chan; 558 enum mac80211_scan_state next_scan_state; 559 560 /* 561 * check if at least one STA interface is associated, 562 * check if at least one STA interface has pending tx frames 563 * and grab the lowest used beacon interval 564 */ 565 mutex_lock(&local->iflist_mtx); 566 list_for_each_entry(sdata, &local->interfaces, list) { 567 if (!ieee80211_sdata_running(sdata)) 568 continue; 569 570 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 571 if (sdata->u.mgd.associated) { 572 associated = true; 573 574 if (!qdisc_all_tx_empty(sdata->dev)) { 575 tx_empty = false; 576 break; 577 } 578 } 579 } 580 } 581 mutex_unlock(&local->iflist_mtx); 582 583 next_chan = local->scan_req->channels[local->scan_channel_idx]; 584 585 /* 586 * we're currently scanning a different channel, let's 587 * see if we can scan another channel without interfering 588 * with the current traffic situation. 589 * 590 * Keep good latency, do not stay off-channel more than 125 ms. 591 */ 592 593 bad_latency = time_after(jiffies + 594 ieee80211_scan_get_channel_time(next_chan), 595 local->leave_oper_channel_time + HZ / 8); 596 597 if (associated && !tx_empty) { 598 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 599 next_scan_state = SCAN_ABORT; 600 else 601 next_scan_state = SCAN_SUSPEND; 602 } else if (associated && bad_latency) { 603 next_scan_state = SCAN_SUSPEND; 604 } else { 605 next_scan_state = SCAN_SET_CHANNEL; 606 } 607 608 local->next_scan_state = next_scan_state; 609 610 *next_delay = 0; 611 } 612 613 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 614 unsigned long *next_delay) 615 { 616 int skip; 617 struct ieee80211_channel *chan; 618 619 skip = 0; 620 chan = local->scan_req->channels[local->scan_channel_idx]; 621 622 local->scan_channel = chan; 623 624 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 625 skip = 1; 626 627 /* advance state machine to next channel/band */ 628 local->scan_channel_idx++; 629 630 if (skip) { 631 /* if we skip this channel return to the decision state */ 632 local->next_scan_state = SCAN_DECISION; 633 return; 634 } 635 636 /* 637 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 638 * (which unfortunately doesn't say _why_ step a) is done, 639 * but it waits for the probe delay or until a frame is 640 * received - and the received frame would update the NAV). 641 * For now, we do not support waiting until a frame is 642 * received. 643 * 644 * In any case, it is not necessary for a passive scan. 645 */ 646 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 647 !local->scan_req->n_ssids) { 648 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 649 local->next_scan_state = SCAN_DECISION; 650 return; 651 } 652 653 /* active scan, send probes */ 654 *next_delay = IEEE80211_PROBE_DELAY; 655 local->next_scan_state = SCAN_SEND_PROBE; 656 } 657 658 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 659 unsigned long *next_delay) 660 { 661 /* switch back to the operating channel */ 662 local->scan_channel = NULL; 663 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 664 665 /* disable PS */ 666 ieee80211_offchannel_return(local); 667 668 *next_delay = HZ / 5; 669 /* afterwards, resume scan & go to next channel */ 670 local->next_scan_state = SCAN_RESUME; 671 } 672 673 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 674 unsigned long *next_delay) 675 { 676 ieee80211_offchannel_stop_vifs(local); 677 678 if (local->ops->flush) { 679 ieee80211_flush_queues(local, NULL); 680 *next_delay = 0; 681 } else 682 *next_delay = HZ / 10; 683 684 /* remember when we left the operating channel */ 685 local->leave_oper_channel_time = jiffies; 686 687 /* advance to the next channel to be scanned */ 688 local->next_scan_state = SCAN_SET_CHANNEL; 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; 696 unsigned long next_delay = 0; 697 bool aborted, hw_scan; 698 699 mutex_lock(&local->mtx); 700 701 sdata = rcu_dereference_protected(local->scan_sdata, 702 lockdep_is_held(&local->mtx)); 703 704 /* When scanning on-channel, the first-callback means completed. */ 705 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 706 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 707 goto out_complete; 708 } 709 710 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 711 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 712 goto out_complete; 713 } 714 715 if (!sdata || !local->scan_req) 716 goto out; 717 718 if (local->scan_req && !local->scanning) { 719 struct cfg80211_scan_request *req = local->scan_req; 720 int rc; 721 722 local->scan_req = NULL; 723 rcu_assign_pointer(local->scan_sdata, NULL); 724 725 rc = __ieee80211_start_scan(sdata, req); 726 if (rc) { 727 /* need to complete scan in cfg80211 */ 728 local->scan_req = req; 729 aborted = true; 730 goto out_complete; 731 } else 732 goto out; 733 } 734 735 /* 736 * Avoid re-scheduling when the sdata is going away. 737 */ 738 if (!ieee80211_sdata_running(sdata)) { 739 aborted = true; 740 goto out_complete; 741 } 742 743 /* 744 * as long as no delay is required advance immediately 745 * without scheduling a new work 746 */ 747 do { 748 if (!ieee80211_sdata_running(sdata)) { 749 aborted = true; 750 goto out_complete; 751 } 752 753 switch (local->next_scan_state) { 754 case SCAN_DECISION: 755 /* if no more bands/channels left, complete scan */ 756 if (local->scan_channel_idx >= local->scan_req->n_channels) { 757 aborted = false; 758 goto out_complete; 759 } 760 ieee80211_scan_state_decision(local, &next_delay); 761 break; 762 case SCAN_SET_CHANNEL: 763 ieee80211_scan_state_set_channel(local, &next_delay); 764 break; 765 case SCAN_SEND_PROBE: 766 ieee80211_scan_state_send_probe(local, &next_delay); 767 break; 768 case SCAN_SUSPEND: 769 ieee80211_scan_state_suspend(local, &next_delay); 770 break; 771 case SCAN_RESUME: 772 ieee80211_scan_state_resume(local, &next_delay); 773 break; 774 case SCAN_ABORT: 775 aborted = true; 776 goto out_complete; 777 } 778 } while (next_delay == 0); 779 780 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 781 goto out; 782 783 out_complete: 784 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 785 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 786 out: 787 mutex_unlock(&local->mtx); 788 } 789 790 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 791 struct cfg80211_scan_request *req) 792 { 793 int res; 794 795 mutex_lock(&sdata->local->mtx); 796 res = __ieee80211_start_scan(sdata, req); 797 mutex_unlock(&sdata->local->mtx); 798 799 return res; 800 } 801 802 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 803 const u8 *ssid, u8 ssid_len, 804 struct ieee80211_channel *chan) 805 { 806 struct ieee80211_local *local = sdata->local; 807 int ret = -EBUSY; 808 enum ieee80211_band band; 809 810 mutex_lock(&local->mtx); 811 812 /* busy scanning */ 813 if (local->scan_req) 814 goto unlock; 815 816 /* fill internal scan request */ 817 if (!chan) { 818 int i, max_n; 819 int n_ch = 0; 820 821 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 822 if (!local->hw.wiphy->bands[band]) 823 continue; 824 825 max_n = local->hw.wiphy->bands[band]->n_channels; 826 for (i = 0; i < max_n; i++) { 827 struct ieee80211_channel *tmp_ch = 828 &local->hw.wiphy->bands[band]->channels[i]; 829 830 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS | 831 IEEE80211_CHAN_DISABLED)) 832 continue; 833 834 local->int_scan_req->channels[n_ch] = tmp_ch; 835 n_ch++; 836 } 837 } 838 839 if (WARN_ON_ONCE(n_ch == 0)) 840 goto unlock; 841 842 local->int_scan_req->n_channels = n_ch; 843 } else { 844 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS | 845 IEEE80211_CHAN_DISABLED))) 846 goto unlock; 847 848 local->int_scan_req->channels[0] = chan; 849 local->int_scan_req->n_channels = 1; 850 } 851 852 local->int_scan_req->ssids = &local->scan_ssid; 853 local->int_scan_req->n_ssids = 1; 854 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 855 local->int_scan_req->ssids[0].ssid_len = ssid_len; 856 857 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 858 unlock: 859 mutex_unlock(&local->mtx); 860 return ret; 861 } 862 863 /* 864 * Only call this function when a scan can't be queued -- under RTNL. 865 */ 866 void ieee80211_scan_cancel(struct ieee80211_local *local) 867 { 868 /* 869 * We are canceling software scan, or deferred scan that was not 870 * yet really started (see __ieee80211_start_scan ). 871 * 872 * Regarding hardware scan: 873 * - we can not call __ieee80211_scan_completed() as when 874 * SCAN_HW_SCANNING bit is set this function change 875 * local->hw_scan_req to operate on 5G band, what race with 876 * driver which can use local->hw_scan_req 877 * 878 * - we can not cancel scan_work since driver can schedule it 879 * by ieee80211_scan_completed(..., true) to finish scan 880 * 881 * Hence we only call the cancel_hw_scan() callback, but the low-level 882 * driver is still responsible for calling ieee80211_scan_completed() 883 * after the scan was completed/aborted. 884 */ 885 886 mutex_lock(&local->mtx); 887 if (!local->scan_req) 888 goto out; 889 890 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 891 if (local->ops->cancel_hw_scan) 892 drv_cancel_hw_scan(local, 893 rcu_dereference_protected(local->scan_sdata, 894 lockdep_is_held(&local->mtx))); 895 goto out; 896 } 897 898 /* 899 * If the work is currently running, it must be blocked on 900 * the mutex, but we'll set scan_sdata = NULL and it'll 901 * simply exit once it acquires the mutex. 902 */ 903 cancel_delayed_work(&local->scan_work); 904 /* and clean up */ 905 __ieee80211_scan_completed(&local->hw, true, false); 906 out: 907 mutex_unlock(&local->mtx); 908 } 909 910 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 911 struct cfg80211_sched_scan_request *req) 912 { 913 struct ieee80211_local *local = sdata->local; 914 struct ieee80211_sched_scan_ies sched_scan_ies = {}; 915 int ret, i, iebufsz; 916 917 iebufsz = 2 + IEEE80211_MAX_SSID_LEN + 918 local->scan_ies_len + req->ie_len; 919 920 mutex_lock(&local->mtx); 921 922 if (rcu_access_pointer(local->sched_scan_sdata)) { 923 ret = -EBUSY; 924 goto out; 925 } 926 927 if (!local->ops->sched_scan_start) { 928 ret = -ENOTSUPP; 929 goto out; 930 } 931 932 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 933 if (!local->hw.wiphy->bands[i]) 934 continue; 935 936 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL); 937 if (!sched_scan_ies.ie[i]) { 938 ret = -ENOMEM; 939 goto out_free; 940 } 941 942 sched_scan_ies.len[i] = 943 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i], 944 iebufsz, req->ie, req->ie_len, 945 i, (u32) -1, 0); 946 } 947 948 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 949 if (ret == 0) 950 rcu_assign_pointer(local->sched_scan_sdata, sdata); 951 952 out_free: 953 while (i > 0) 954 kfree(sched_scan_ies.ie[--i]); 955 out: 956 mutex_unlock(&local->mtx); 957 return ret; 958 } 959 960 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 961 { 962 struct ieee80211_local *local = sdata->local; 963 int ret = 0; 964 965 mutex_lock(&local->mtx); 966 967 if (!local->ops->sched_scan_stop) { 968 ret = -ENOTSUPP; 969 goto out; 970 } 971 972 if (rcu_access_pointer(local->sched_scan_sdata)) 973 drv_sched_scan_stop(local, sdata); 974 975 out: 976 mutex_unlock(&local->mtx); 977 978 return ret; 979 } 980 981 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 982 { 983 struct ieee80211_local *local = hw_to_local(hw); 984 985 trace_api_sched_scan_results(local); 986 987 cfg80211_sched_scan_results(hw->wiphy); 988 } 989 EXPORT_SYMBOL(ieee80211_sched_scan_results); 990 991 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 992 { 993 struct ieee80211_local *local = 994 container_of(work, struct ieee80211_local, 995 sched_scan_stopped_work); 996 997 mutex_lock(&local->mtx); 998 999 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1000 mutex_unlock(&local->mtx); 1001 return; 1002 } 1003 1004 rcu_assign_pointer(local->sched_scan_sdata, NULL); 1005 1006 mutex_unlock(&local->mtx); 1007 1008 cfg80211_sched_scan_stopped(local->hw.wiphy); 1009 } 1010 1011 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1012 { 1013 struct ieee80211_local *local = hw_to_local(hw); 1014 1015 trace_api_sched_scan_stopped(local); 1016 1017 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 1018 } 1019 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1020