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 * Copyright 2013-2014 Intel Mobile Communications GmbH 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #include <linux/if_arp.h> 17 #include <linux/etherdevice.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/pm_qos.h> 20 #include <net/sch_generic.h> 21 #include <linux/slab.h> 22 #include <linux/export.h> 23 #include <net/mac80211.h> 24 25 #include "ieee80211_i.h" 26 #include "driver-ops.h" 27 #include "mesh.h" 28 29 #define IEEE80211_PROBE_DELAY (HZ / 33) 30 #define IEEE80211_CHANNEL_TIME (HZ / 33) 31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9) 32 33 void ieee80211_rx_bss_put(struct ieee80211_local *local, 34 struct ieee80211_bss *bss) 35 { 36 if (!bss) 37 return; 38 cfg80211_put_bss(local->hw.wiphy, 39 container_of((void *)bss, struct cfg80211_bss, priv)); 40 } 41 42 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 43 { 44 u8 qos_info; 45 46 if (elems->wmm_info && elems->wmm_info_len == 7 47 && elems->wmm_info[5] == 1) 48 qos_info = elems->wmm_info[6]; 49 else if (elems->wmm_param && elems->wmm_param_len == 24 50 && elems->wmm_param[5] == 1) 51 qos_info = elems->wmm_param[6]; 52 else 53 /* no valid wmm information or parameter element found */ 54 return false; 55 56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 57 } 58 59 struct ieee80211_bss * 60 ieee80211_bss_info_update(struct ieee80211_local *local, 61 struct ieee80211_rx_status *rx_status, 62 struct ieee80211_mgmt *mgmt, size_t len, 63 struct ieee802_11_elems *elems, 64 struct ieee80211_channel *channel) 65 { 66 bool beacon = ieee80211_is_beacon(mgmt->frame_control); 67 struct cfg80211_bss *cbss; 68 struct ieee80211_bss *bss; 69 int clen, srlen; 70 enum nl80211_bss_scan_width scan_width; 71 s32 signal = 0; 72 73 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 74 signal = rx_status->signal * 100; 75 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 76 signal = (rx_status->signal * 100) / local->hw.max_signal; 77 78 scan_width = NL80211_BSS_CHAN_WIDTH_20; 79 if (rx_status->flag & RX_FLAG_5MHZ) 80 scan_width = NL80211_BSS_CHAN_WIDTH_5; 81 if (rx_status->flag & RX_FLAG_10MHZ) 82 scan_width = NL80211_BSS_CHAN_WIDTH_10; 83 84 cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel, 85 scan_width, mgmt, len, signal, 86 GFP_ATOMIC); 87 if (!cbss) 88 return NULL; 89 90 bss = (void *)cbss->priv; 91 92 if (beacon) 93 bss->device_ts_beacon = rx_status->device_timestamp; 94 else 95 bss->device_ts_presp = rx_status->device_timestamp; 96 97 if (elems->parse_error) { 98 if (beacon) 99 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 100 else 101 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 102 } else { 103 if (beacon) 104 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 105 else 106 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 107 } 108 109 /* save the ERP value so that it is available at association time */ 110 if (elems->erp_info && (!elems->parse_error || 111 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 112 bss->erp_value = elems->erp_info[0]; 113 bss->has_erp_value = true; 114 if (!elems->parse_error) 115 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 116 } 117 118 /* replace old supported rates if we get new values */ 119 if (!elems->parse_error || 120 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 121 srlen = 0; 122 if (elems->supp_rates) { 123 clen = IEEE80211_MAX_SUPP_RATES; 124 if (clen > elems->supp_rates_len) 125 clen = elems->supp_rates_len; 126 memcpy(bss->supp_rates, elems->supp_rates, clen); 127 srlen += clen; 128 } 129 if (elems->ext_supp_rates) { 130 clen = IEEE80211_MAX_SUPP_RATES - srlen; 131 if (clen > elems->ext_supp_rates_len) 132 clen = elems->ext_supp_rates_len; 133 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 134 clen); 135 srlen += clen; 136 } 137 if (srlen) { 138 bss->supp_rates_len = srlen; 139 if (!elems->parse_error) 140 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 141 } 142 } 143 144 if (!elems->parse_error || 145 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 146 bss->wmm_used = elems->wmm_param || elems->wmm_info; 147 bss->uapsd_supported = is_uapsd_supported(elems); 148 if (!elems->parse_error) 149 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 150 } 151 152 if (beacon) { 153 struct ieee80211_supported_band *sband = 154 local->hw.wiphy->bands[rx_status->band]; 155 if (!(rx_status->flag & RX_FLAG_HT) && 156 !(rx_status->flag & RX_FLAG_VHT)) 157 bss->beacon_rate = 158 &sband->bitrates[rx_status->rate_idx]; 159 } 160 161 return bss; 162 } 163 164 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 165 { 166 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 167 struct ieee80211_sub_if_data *sdata1, *sdata2; 168 struct ieee80211_mgmt *mgmt = (void *)skb->data; 169 struct ieee80211_bss *bss; 170 u8 *elements; 171 struct ieee80211_channel *channel; 172 size_t baselen; 173 struct ieee802_11_elems elems; 174 175 if (skb->len < 24 || 176 (!ieee80211_is_probe_resp(mgmt->frame_control) && 177 !ieee80211_is_beacon(mgmt->frame_control))) 178 return; 179 180 sdata1 = rcu_dereference(local->scan_sdata); 181 sdata2 = rcu_dereference(local->sched_scan_sdata); 182 183 if (likely(!sdata1 && !sdata2)) 184 return; 185 186 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 187 /* ignore ProbeResp to foreign address */ 188 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) && 189 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr))) 190 return; 191 192 elements = mgmt->u.probe_resp.variable; 193 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 194 } else { 195 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 196 elements = mgmt->u.beacon.variable; 197 } 198 199 if (baselen > skb->len) 200 return; 201 202 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 203 204 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 205 206 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 207 return; 208 209 bss = ieee80211_bss_info_update(local, rx_status, 210 mgmt, skb->len, &elems, 211 channel); 212 if (bss) 213 ieee80211_rx_bss_put(local, bss); 214 } 215 216 static void 217 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, 218 enum nl80211_bss_scan_width scan_width) 219 { 220 memset(chandef, 0, sizeof(*chandef)); 221 switch (scan_width) { 222 case NL80211_BSS_CHAN_WIDTH_5: 223 chandef->width = NL80211_CHAN_WIDTH_5; 224 break; 225 case NL80211_BSS_CHAN_WIDTH_10: 226 chandef->width = NL80211_CHAN_WIDTH_10; 227 break; 228 default: 229 chandef->width = NL80211_CHAN_WIDTH_20_NOHT; 230 break; 231 } 232 } 233 234 /* return false if no more work */ 235 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 236 { 237 struct cfg80211_scan_request *req = local->scan_req; 238 struct cfg80211_chan_def chandef; 239 u8 bands_used = 0; 240 int i, ielen, n_chans; 241 242 if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) 243 return false; 244 245 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 246 for (i = 0; i < req->n_channels; i++) { 247 local->hw_scan_req->req.channels[i] = req->channels[i]; 248 bands_used |= BIT(req->channels[i]->band); 249 } 250 251 n_chans = req->n_channels; 252 } else { 253 do { 254 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 255 return false; 256 257 n_chans = 0; 258 259 for (i = 0; i < req->n_channels; i++) { 260 if (req->channels[i]->band != 261 local->hw_scan_band) 262 continue; 263 local->hw_scan_req->req.channels[n_chans] = 264 req->channels[i]; 265 n_chans++; 266 bands_used |= BIT(req->channels[i]->band); 267 } 268 269 local->hw_scan_band++; 270 } while (!n_chans); 271 } 272 273 local->hw_scan_req->req.n_channels = n_chans; 274 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 275 276 ielen = ieee80211_build_preq_ies(local, 277 (u8 *)local->hw_scan_req->req.ie, 278 local->hw_scan_ies_bufsize, 279 &local->hw_scan_req->ies, 280 req->ie, req->ie_len, 281 bands_used, req->rates, &chandef); 282 local->hw_scan_req->req.ie_len = ielen; 283 local->hw_scan_req->req.no_cck = req->no_cck; 284 285 return true; 286 } 287 288 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 289 { 290 struct ieee80211_local *local = hw_to_local(hw); 291 bool hw_scan = local->ops->hw_scan; 292 bool was_scanning = local->scanning; 293 294 lockdep_assert_held(&local->mtx); 295 296 /* 297 * It's ok to abort a not-yet-running scan (that 298 * we have one at all will be verified by checking 299 * local->scan_req next), but not to complete it 300 * successfully. 301 */ 302 if (WARN_ON(!local->scanning && !aborted)) 303 aborted = true; 304 305 if (WARN_ON(!local->scan_req)) 306 return; 307 308 if (hw_scan && !aborted && 309 !(local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) && 310 ieee80211_prep_hw_scan(local)) { 311 int rc; 312 313 rc = drv_hw_scan(local, 314 rcu_dereference_protected(local->scan_sdata, 315 lockdep_is_held(&local->mtx)), 316 local->hw_scan_req); 317 318 if (rc == 0) 319 return; 320 } 321 322 kfree(local->hw_scan_req); 323 local->hw_scan_req = NULL; 324 325 if (local->scan_req != local->int_scan_req) 326 cfg80211_scan_done(local->scan_req, aborted); 327 local->scan_req = NULL; 328 RCU_INIT_POINTER(local->scan_sdata, NULL); 329 330 local->scanning = 0; 331 local->scan_chandef.chan = NULL; 332 333 /* Set power back to normal operating levels. */ 334 ieee80211_hw_config(local, 0); 335 336 if (!hw_scan) { 337 ieee80211_configure_filter(local); 338 drv_sw_scan_complete(local); 339 ieee80211_offchannel_return(local); 340 } 341 342 ieee80211_recalc_idle(local); 343 344 ieee80211_mlme_notify_scan_completed(local); 345 ieee80211_ibss_notify_scan_completed(local); 346 ieee80211_mesh_notify_scan_completed(local); 347 if (was_scanning) 348 ieee80211_start_next_roc(local); 349 } 350 351 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 352 { 353 struct ieee80211_local *local = hw_to_local(hw); 354 355 trace_api_scan_completed(local, aborted); 356 357 set_bit(SCAN_COMPLETED, &local->scanning); 358 if (aborted) 359 set_bit(SCAN_ABORTED, &local->scanning); 360 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 361 } 362 EXPORT_SYMBOL(ieee80211_scan_completed); 363 364 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 365 { 366 /* Software scan is not supported in multi-channel cases */ 367 if (local->use_chanctx) 368 return -EOPNOTSUPP; 369 370 /* 371 * Hardware/driver doesn't support hw_scan, so use software 372 * scanning instead. First send a nullfunc frame with power save 373 * bit on so that AP will buffer the frames for us while we are not 374 * listening, then send probe requests to each channel and wait for 375 * the responses. After all channels are scanned, tune back to the 376 * original channel and send a nullfunc frame with power save bit 377 * off to trigger the AP to send us all the buffered frames. 378 * 379 * Note that while local->sw_scanning is true everything else but 380 * nullfunc frames and probe requests will be dropped in 381 * ieee80211_tx_h_check_assoc(). 382 */ 383 drv_sw_scan_start(local); 384 385 local->leave_oper_channel_time = jiffies; 386 local->next_scan_state = SCAN_DECISION; 387 local->scan_channel_idx = 0; 388 389 ieee80211_offchannel_stop_vifs(local); 390 391 /* ensure nullfunc is transmitted before leaving operating channel */ 392 ieee80211_flush_queues(local, NULL); 393 394 ieee80211_configure_filter(local); 395 396 /* We need to set power level at maximum rate for scanning. */ 397 ieee80211_hw_config(local, 0); 398 399 ieee80211_queue_delayed_work(&local->hw, 400 &local->scan_work, 0); 401 402 return 0; 403 } 404 405 static bool ieee80211_can_scan(struct ieee80211_local *local, 406 struct ieee80211_sub_if_data *sdata) 407 { 408 if (local->radar_detect_enabled) 409 return false; 410 411 if (!list_empty(&local->roc_list)) 412 return false; 413 414 if (sdata->vif.type == NL80211_IFTYPE_STATION && 415 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) 416 return false; 417 418 return true; 419 } 420 421 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 422 { 423 lockdep_assert_held(&local->mtx); 424 425 if (!local->scan_req || local->scanning) 426 return; 427 428 if (!ieee80211_can_scan(local, 429 rcu_dereference_protected( 430 local->scan_sdata, 431 lockdep_is_held(&local->mtx)))) 432 return; 433 434 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 435 round_jiffies_relative(0)); 436 } 437 438 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 439 unsigned long *next_delay) 440 { 441 int i; 442 struct ieee80211_sub_if_data *sdata; 443 enum ieee80211_band band = local->hw.conf.chandef.chan->band; 444 u32 tx_flags; 445 446 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 447 if (local->scan_req->no_cck) 448 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 449 450 sdata = rcu_dereference_protected(local->scan_sdata, 451 lockdep_is_held(&local->mtx)); 452 453 for (i = 0; i < local->scan_req->n_ssids; i++) 454 ieee80211_send_probe_req( 455 sdata, NULL, 456 local->scan_req->ssids[i].ssid, 457 local->scan_req->ssids[i].ssid_len, 458 local->scan_req->ie, local->scan_req->ie_len, 459 local->scan_req->rates[band], false, 460 tx_flags, local->hw.conf.chandef.chan, true); 461 462 /* 463 * After sending probe requests, wait for probe responses 464 * on the channel. 465 */ 466 *next_delay = IEEE80211_CHANNEL_TIME; 467 local->next_scan_state = SCAN_DECISION; 468 } 469 470 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 471 struct cfg80211_scan_request *req) 472 { 473 struct ieee80211_local *local = sdata->local; 474 int rc; 475 476 lockdep_assert_held(&local->mtx); 477 478 if (local->scan_req) 479 return -EBUSY; 480 481 if (!ieee80211_can_scan(local, sdata)) { 482 /* wait for the work to finish/time out */ 483 local->scan_req = req; 484 rcu_assign_pointer(local->scan_sdata, sdata); 485 return 0; 486 } 487 488 if (local->ops->hw_scan) { 489 u8 *ies; 490 491 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; 492 493 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 494 int i, n_bands = 0; 495 u8 bands_counted = 0; 496 497 for (i = 0; i < req->n_channels; i++) { 498 if (bands_counted & BIT(req->channels[i]->band)) 499 continue; 500 bands_counted |= BIT(req->channels[i]->band); 501 n_bands++; 502 } 503 504 local->hw_scan_ies_bufsize *= n_bands; 505 } 506 507 local->hw_scan_req = kmalloc( 508 sizeof(*local->hw_scan_req) + 509 req->n_channels * sizeof(req->channels[0]) + 510 local->hw_scan_ies_bufsize, GFP_KERNEL); 511 if (!local->hw_scan_req) 512 return -ENOMEM; 513 514 local->hw_scan_req->req.ssids = req->ssids; 515 local->hw_scan_req->req.n_ssids = req->n_ssids; 516 ies = (u8 *)local->hw_scan_req + 517 sizeof(*local->hw_scan_req) + 518 req->n_channels * sizeof(req->channels[0]); 519 local->hw_scan_req->req.ie = ies; 520 local->hw_scan_req->req.flags = req->flags; 521 522 local->hw_scan_band = 0; 523 524 /* 525 * After allocating local->hw_scan_req, we must 526 * go through until ieee80211_prep_hw_scan(), so 527 * anything that might be changed here and leave 528 * this function early must not go after this 529 * allocation. 530 */ 531 } 532 533 local->scan_req = req; 534 rcu_assign_pointer(local->scan_sdata, sdata); 535 536 if (local->ops->hw_scan) { 537 __set_bit(SCAN_HW_SCANNING, &local->scanning); 538 } else if ((req->n_channels == 1) && 539 (req->channels[0] == local->_oper_chandef.chan)) { 540 /* 541 * If we are scanning only on the operating channel 542 * then we do not need to stop normal activities 543 */ 544 unsigned long next_delay; 545 546 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 547 548 ieee80211_recalc_idle(local); 549 550 /* Notify driver scan is starting, keep order of operations 551 * same as normal software scan, in case that matters. */ 552 drv_sw_scan_start(local); 553 554 ieee80211_configure_filter(local); /* accept probe-responses */ 555 556 /* We need to ensure power level is at max for scanning. */ 557 ieee80211_hw_config(local, 0); 558 559 if ((req->channels[0]->flags & 560 IEEE80211_CHAN_NO_IR) || 561 !local->scan_req->n_ssids) { 562 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 563 } else { 564 ieee80211_scan_state_send_probe(local, &next_delay); 565 next_delay = IEEE80211_CHANNEL_TIME; 566 } 567 568 /* Now, just wait a bit and we are all done! */ 569 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 570 next_delay); 571 return 0; 572 } else { 573 /* Do normal software scan */ 574 __set_bit(SCAN_SW_SCANNING, &local->scanning); 575 } 576 577 ieee80211_recalc_idle(local); 578 579 if (local->ops->hw_scan) { 580 WARN_ON(!ieee80211_prep_hw_scan(local)); 581 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 582 } else 583 rc = ieee80211_start_sw_scan(local); 584 585 if (rc) { 586 kfree(local->hw_scan_req); 587 local->hw_scan_req = NULL; 588 local->scanning = 0; 589 590 ieee80211_recalc_idle(local); 591 592 local->scan_req = NULL; 593 RCU_INIT_POINTER(local->scan_sdata, NULL); 594 } 595 596 return rc; 597 } 598 599 static unsigned long 600 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 601 { 602 /* 603 * TODO: channel switching also consumes quite some time, 604 * add that delay as well to get a better estimation 605 */ 606 if (chan->flags & IEEE80211_CHAN_NO_IR) 607 return IEEE80211_PASSIVE_CHANNEL_TIME; 608 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 609 } 610 611 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 612 unsigned long *next_delay) 613 { 614 bool associated = false; 615 bool tx_empty = true; 616 bool bad_latency; 617 struct ieee80211_sub_if_data *sdata; 618 struct ieee80211_channel *next_chan; 619 enum mac80211_scan_state next_scan_state; 620 621 /* 622 * check if at least one STA interface is associated, 623 * check if at least one STA interface has pending tx frames 624 * and grab the lowest used beacon interval 625 */ 626 mutex_lock(&local->iflist_mtx); 627 list_for_each_entry(sdata, &local->interfaces, list) { 628 if (!ieee80211_sdata_running(sdata)) 629 continue; 630 631 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 632 if (sdata->u.mgd.associated) { 633 associated = true; 634 635 if (!qdisc_all_tx_empty(sdata->dev)) { 636 tx_empty = false; 637 break; 638 } 639 } 640 } 641 } 642 mutex_unlock(&local->iflist_mtx); 643 644 next_chan = local->scan_req->channels[local->scan_channel_idx]; 645 646 /* 647 * we're currently scanning a different channel, let's 648 * see if we can scan another channel without interfering 649 * with the current traffic situation. 650 * 651 * Keep good latency, do not stay off-channel more than 125 ms. 652 */ 653 654 bad_latency = time_after(jiffies + 655 ieee80211_scan_get_channel_time(next_chan), 656 local->leave_oper_channel_time + HZ / 8); 657 658 if (associated && !tx_empty) { 659 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 660 next_scan_state = SCAN_ABORT; 661 else 662 next_scan_state = SCAN_SUSPEND; 663 } else if (associated && bad_latency) { 664 next_scan_state = SCAN_SUSPEND; 665 } else { 666 next_scan_state = SCAN_SET_CHANNEL; 667 } 668 669 local->next_scan_state = next_scan_state; 670 671 *next_delay = 0; 672 } 673 674 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 675 unsigned long *next_delay) 676 { 677 int skip; 678 struct ieee80211_channel *chan; 679 enum nl80211_bss_scan_width oper_scan_width; 680 681 skip = 0; 682 chan = local->scan_req->channels[local->scan_channel_idx]; 683 684 local->scan_chandef.chan = chan; 685 local->scan_chandef.center_freq1 = chan->center_freq; 686 local->scan_chandef.center_freq2 = 0; 687 switch (local->scan_req->scan_width) { 688 case NL80211_BSS_CHAN_WIDTH_5: 689 local->scan_chandef.width = NL80211_CHAN_WIDTH_5; 690 break; 691 case NL80211_BSS_CHAN_WIDTH_10: 692 local->scan_chandef.width = NL80211_CHAN_WIDTH_10; 693 break; 694 case NL80211_BSS_CHAN_WIDTH_20: 695 /* If scanning on oper channel, use whatever channel-type 696 * is currently in use. 697 */ 698 oper_scan_width = cfg80211_chandef_to_scan_width( 699 &local->_oper_chandef); 700 if (chan == local->_oper_chandef.chan && 701 oper_scan_width == local->scan_req->scan_width) 702 local->scan_chandef = local->_oper_chandef; 703 else 704 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; 705 break; 706 } 707 708 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 709 skip = 1; 710 711 /* advance state machine to next channel/band */ 712 local->scan_channel_idx++; 713 714 if (skip) { 715 /* if we skip this channel return to the decision state */ 716 local->next_scan_state = SCAN_DECISION; 717 return; 718 } 719 720 /* 721 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 722 * (which unfortunately doesn't say _why_ step a) is done, 723 * but it waits for the probe delay or until a frame is 724 * received - and the received frame would update the NAV). 725 * For now, we do not support waiting until a frame is 726 * received. 727 * 728 * In any case, it is not necessary for a passive scan. 729 */ 730 if (chan->flags & IEEE80211_CHAN_NO_IR || 731 !local->scan_req->n_ssids) { 732 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 733 local->next_scan_state = SCAN_DECISION; 734 return; 735 } 736 737 /* active scan, send probes */ 738 *next_delay = IEEE80211_PROBE_DELAY; 739 local->next_scan_state = SCAN_SEND_PROBE; 740 } 741 742 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 743 unsigned long *next_delay) 744 { 745 /* switch back to the operating channel */ 746 local->scan_chandef.chan = NULL; 747 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 748 749 /* disable PS */ 750 ieee80211_offchannel_return(local); 751 752 *next_delay = HZ / 5; 753 /* afterwards, resume scan & go to next channel */ 754 local->next_scan_state = SCAN_RESUME; 755 } 756 757 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 758 unsigned long *next_delay) 759 { 760 ieee80211_offchannel_stop_vifs(local); 761 762 if (local->ops->flush) { 763 ieee80211_flush_queues(local, NULL); 764 *next_delay = 0; 765 } else 766 *next_delay = HZ / 10; 767 768 /* remember when we left the operating channel */ 769 local->leave_oper_channel_time = jiffies; 770 771 /* advance to the next channel to be scanned */ 772 local->next_scan_state = SCAN_SET_CHANNEL; 773 } 774 775 void ieee80211_scan_work(struct work_struct *work) 776 { 777 struct ieee80211_local *local = 778 container_of(work, struct ieee80211_local, scan_work.work); 779 struct ieee80211_sub_if_data *sdata; 780 unsigned long next_delay = 0; 781 bool aborted; 782 783 mutex_lock(&local->mtx); 784 785 sdata = rcu_dereference_protected(local->scan_sdata, 786 lockdep_is_held(&local->mtx)); 787 788 /* When scanning on-channel, the first-callback means completed. */ 789 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 790 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 791 goto out_complete; 792 } 793 794 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 795 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 796 goto out_complete; 797 } 798 799 if (!sdata || !local->scan_req) 800 goto out; 801 802 if (local->scan_req && !local->scanning) { 803 struct cfg80211_scan_request *req = local->scan_req; 804 int rc; 805 806 local->scan_req = NULL; 807 RCU_INIT_POINTER(local->scan_sdata, NULL); 808 809 rc = __ieee80211_start_scan(sdata, req); 810 if (rc) { 811 /* need to complete scan in cfg80211 */ 812 local->scan_req = req; 813 aborted = true; 814 goto out_complete; 815 } else 816 goto out; 817 } 818 819 /* 820 * as long as no delay is required advance immediately 821 * without scheduling a new work 822 */ 823 do { 824 if (!ieee80211_sdata_running(sdata)) { 825 aborted = true; 826 goto out_complete; 827 } 828 829 switch (local->next_scan_state) { 830 case SCAN_DECISION: 831 /* if no more bands/channels left, complete scan */ 832 if (local->scan_channel_idx >= local->scan_req->n_channels) { 833 aborted = false; 834 goto out_complete; 835 } 836 ieee80211_scan_state_decision(local, &next_delay); 837 break; 838 case SCAN_SET_CHANNEL: 839 ieee80211_scan_state_set_channel(local, &next_delay); 840 break; 841 case SCAN_SEND_PROBE: 842 ieee80211_scan_state_send_probe(local, &next_delay); 843 break; 844 case SCAN_SUSPEND: 845 ieee80211_scan_state_suspend(local, &next_delay); 846 break; 847 case SCAN_RESUME: 848 ieee80211_scan_state_resume(local, &next_delay); 849 break; 850 case SCAN_ABORT: 851 aborted = true; 852 goto out_complete; 853 } 854 } while (next_delay == 0); 855 856 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 857 goto out; 858 859 out_complete: 860 __ieee80211_scan_completed(&local->hw, aborted); 861 out: 862 mutex_unlock(&local->mtx); 863 } 864 865 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 866 struct cfg80211_scan_request *req) 867 { 868 int res; 869 870 mutex_lock(&sdata->local->mtx); 871 res = __ieee80211_start_scan(sdata, req); 872 mutex_unlock(&sdata->local->mtx); 873 874 return res; 875 } 876 877 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 878 const u8 *ssid, u8 ssid_len, 879 struct ieee80211_channel *chan, 880 enum nl80211_bss_scan_width scan_width) 881 { 882 struct ieee80211_local *local = sdata->local; 883 int ret = -EBUSY; 884 enum ieee80211_band band; 885 886 mutex_lock(&local->mtx); 887 888 /* busy scanning */ 889 if (local->scan_req) 890 goto unlock; 891 892 /* fill internal scan request */ 893 if (!chan) { 894 int i, max_n; 895 int n_ch = 0; 896 897 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 898 if (!local->hw.wiphy->bands[band]) 899 continue; 900 901 max_n = local->hw.wiphy->bands[band]->n_channels; 902 for (i = 0; i < max_n; i++) { 903 struct ieee80211_channel *tmp_ch = 904 &local->hw.wiphy->bands[band]->channels[i]; 905 906 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | 907 IEEE80211_CHAN_DISABLED)) 908 continue; 909 910 local->int_scan_req->channels[n_ch] = tmp_ch; 911 n_ch++; 912 } 913 } 914 915 if (WARN_ON_ONCE(n_ch == 0)) 916 goto unlock; 917 918 local->int_scan_req->n_channels = n_ch; 919 } else { 920 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR | 921 IEEE80211_CHAN_DISABLED))) 922 goto unlock; 923 924 local->int_scan_req->channels[0] = chan; 925 local->int_scan_req->n_channels = 1; 926 } 927 928 local->int_scan_req->ssids = &local->scan_ssid; 929 local->int_scan_req->n_ssids = 1; 930 local->int_scan_req->scan_width = scan_width; 931 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 932 local->int_scan_req->ssids[0].ssid_len = ssid_len; 933 934 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 935 unlock: 936 mutex_unlock(&local->mtx); 937 return ret; 938 } 939 940 /* 941 * Only call this function when a scan can't be queued -- under RTNL. 942 */ 943 void ieee80211_scan_cancel(struct ieee80211_local *local) 944 { 945 /* 946 * We are canceling software scan, or deferred scan that was not 947 * yet really started (see __ieee80211_start_scan ). 948 * 949 * Regarding hardware scan: 950 * - we can not call __ieee80211_scan_completed() as when 951 * SCAN_HW_SCANNING bit is set this function change 952 * local->hw_scan_req to operate on 5G band, what race with 953 * driver which can use local->hw_scan_req 954 * 955 * - we can not cancel scan_work since driver can schedule it 956 * by ieee80211_scan_completed(..., true) to finish scan 957 * 958 * Hence we only call the cancel_hw_scan() callback, but the low-level 959 * driver is still responsible for calling ieee80211_scan_completed() 960 * after the scan was completed/aborted. 961 */ 962 963 mutex_lock(&local->mtx); 964 if (!local->scan_req) 965 goto out; 966 967 /* 968 * We have a scan running and the driver already reported completion, 969 * but the worker hasn't run yet or is stuck on the mutex - mark it as 970 * cancelled. 971 */ 972 if (test_bit(SCAN_HW_SCANNING, &local->scanning) && 973 test_bit(SCAN_COMPLETED, &local->scanning)) { 974 set_bit(SCAN_HW_CANCELLED, &local->scanning); 975 goto out; 976 } 977 978 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 979 /* 980 * Make sure that __ieee80211_scan_completed doesn't trigger a 981 * scan on another band. 982 */ 983 set_bit(SCAN_HW_CANCELLED, &local->scanning); 984 if (local->ops->cancel_hw_scan) 985 drv_cancel_hw_scan(local, 986 rcu_dereference_protected(local->scan_sdata, 987 lockdep_is_held(&local->mtx))); 988 goto out; 989 } 990 991 /* 992 * If the work is currently running, it must be blocked on 993 * the mutex, but we'll set scan_sdata = NULL and it'll 994 * simply exit once it acquires the mutex. 995 */ 996 cancel_delayed_work(&local->scan_work); 997 /* and clean up */ 998 __ieee80211_scan_completed(&local->hw, true); 999 out: 1000 mutex_unlock(&local->mtx); 1001 } 1002 1003 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1004 struct cfg80211_sched_scan_request *req) 1005 { 1006 struct ieee80211_local *local = sdata->local; 1007 struct ieee80211_scan_ies sched_scan_ies = {}; 1008 struct cfg80211_chan_def chandef; 1009 int ret, i, iebufsz, num_bands = 0; 1010 u32 rate_masks[IEEE80211_NUM_BANDS] = {}; 1011 u8 bands_used = 0; 1012 u8 *ie; 1013 size_t len; 1014 1015 iebufsz = local->scan_ies_len + req->ie_len; 1016 1017 lockdep_assert_held(&local->mtx); 1018 1019 if (!local->ops->sched_scan_start) 1020 return -ENOTSUPP; 1021 1022 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 1023 if (local->hw.wiphy->bands[i]) { 1024 bands_used |= BIT(i); 1025 rate_masks[i] = (u32) -1; 1026 num_bands++; 1027 } 1028 } 1029 1030 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL); 1031 if (!ie) { 1032 ret = -ENOMEM; 1033 goto out; 1034 } 1035 1036 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 1037 1038 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz, 1039 &sched_scan_ies, req->ie, 1040 req->ie_len, bands_used, 1041 rate_masks, &chandef); 1042 1043 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 1044 if (ret == 0) { 1045 rcu_assign_pointer(local->sched_scan_sdata, sdata); 1046 local->sched_scan_req = req; 1047 } 1048 1049 kfree(ie); 1050 1051 out: 1052 if (ret) { 1053 /* Clean in case of failure after HW restart or upon resume. */ 1054 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1055 local->sched_scan_req = NULL; 1056 } 1057 1058 return ret; 1059 } 1060 1061 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1062 struct cfg80211_sched_scan_request *req) 1063 { 1064 struct ieee80211_local *local = sdata->local; 1065 int ret; 1066 1067 mutex_lock(&local->mtx); 1068 1069 if (rcu_access_pointer(local->sched_scan_sdata)) { 1070 mutex_unlock(&local->mtx); 1071 return -EBUSY; 1072 } 1073 1074 ret = __ieee80211_request_sched_scan_start(sdata, req); 1075 1076 mutex_unlock(&local->mtx); 1077 return ret; 1078 } 1079 1080 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 1081 { 1082 struct ieee80211_local *local = sdata->local; 1083 int ret = 0; 1084 1085 mutex_lock(&local->mtx); 1086 1087 if (!local->ops->sched_scan_stop) { 1088 ret = -ENOTSUPP; 1089 goto out; 1090 } 1091 1092 /* We don't want to restart sched scan anymore. */ 1093 local->sched_scan_req = NULL; 1094 1095 if (rcu_access_pointer(local->sched_scan_sdata)) { 1096 ret = drv_sched_scan_stop(local, sdata); 1097 if (!ret) 1098 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1099 } 1100 out: 1101 mutex_unlock(&local->mtx); 1102 1103 return ret; 1104 } 1105 1106 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 1107 { 1108 struct ieee80211_local *local = hw_to_local(hw); 1109 1110 trace_api_sched_scan_results(local); 1111 1112 cfg80211_sched_scan_results(hw->wiphy); 1113 } 1114 EXPORT_SYMBOL(ieee80211_sched_scan_results); 1115 1116 void ieee80211_sched_scan_end(struct ieee80211_local *local) 1117 { 1118 mutex_lock(&local->mtx); 1119 1120 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1121 mutex_unlock(&local->mtx); 1122 return; 1123 } 1124 1125 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1126 1127 /* If sched scan was aborted by the driver. */ 1128 local->sched_scan_req = NULL; 1129 1130 mutex_unlock(&local->mtx); 1131 1132 cfg80211_sched_scan_stopped(local->hw.wiphy); 1133 } 1134 1135 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 1136 { 1137 struct ieee80211_local *local = 1138 container_of(work, struct ieee80211_local, 1139 sched_scan_stopped_work); 1140 1141 ieee80211_sched_scan_end(local); 1142 } 1143 1144 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1145 { 1146 struct ieee80211_local *local = hw_to_local(hw); 1147 1148 trace_api_sched_scan_stopped(local); 1149 1150 schedule_work(&local->sched_scan_stopped_work); 1151 } 1152 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1153