scan.c revision c56ef6725068c0ce499e517409c0da226ef51b08
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 32void 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 41static 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 58struct ieee80211_bss * 59ieee80211_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 enum nl80211_bss_scan_width scan_width; 70 s32 signal = 0; 71 72 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 73 signal = rx_status->signal * 100; 74 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 75 signal = (rx_status->signal * 100) / local->hw.max_signal; 76 77 scan_width = NL80211_BSS_CHAN_WIDTH_20; 78 if (rx_status->flag & RX_FLAG_5MHZ) 79 scan_width = NL80211_BSS_CHAN_WIDTH_5; 80 if (rx_status->flag & RX_FLAG_10MHZ) 81 scan_width = NL80211_BSS_CHAN_WIDTH_10; 82 83 cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel, 84 scan_width, mgmt, len, signal, 85 GFP_ATOMIC); 86 if (!cbss) 87 return NULL; 88 89 bss = (void *)cbss->priv; 90 91 if (beacon) 92 bss->device_ts_beacon = rx_status->device_timestamp; 93 else 94 bss->device_ts_presp = rx_status->device_timestamp; 95 96 if (elems->parse_error) { 97 if (beacon) 98 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 99 else 100 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 101 } else { 102 if (beacon) 103 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 104 else 105 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 106 } 107 108 /* save the ERP value so that it is available at association time */ 109 if (elems->erp_info && (!elems->parse_error || 110 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 111 bss->erp_value = elems->erp_info[0]; 112 bss->has_erp_value = true; 113 if (!elems->parse_error) 114 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 115 } 116 117 /* replace old supported rates if we get new values */ 118 if (!elems->parse_error || 119 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 120 srlen = 0; 121 if (elems->supp_rates) { 122 clen = IEEE80211_MAX_SUPP_RATES; 123 if (clen > elems->supp_rates_len) 124 clen = elems->supp_rates_len; 125 memcpy(bss->supp_rates, elems->supp_rates, clen); 126 srlen += clen; 127 } 128 if (elems->ext_supp_rates) { 129 clen = IEEE80211_MAX_SUPP_RATES - srlen; 130 if (clen > elems->ext_supp_rates_len) 131 clen = elems->ext_supp_rates_len; 132 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 133 clen); 134 srlen += clen; 135 } 136 if (srlen) { 137 bss->supp_rates_len = srlen; 138 if (!elems->parse_error) 139 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 140 } 141 } 142 143 if (!elems->parse_error || 144 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 145 bss->wmm_used = elems->wmm_param || elems->wmm_info; 146 bss->uapsd_supported = is_uapsd_supported(elems); 147 if (!elems->parse_error) 148 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 149 } 150 151 if (beacon) { 152 struct ieee80211_supported_band *sband = 153 local->hw.wiphy->bands[rx_status->band]; 154 if (!(rx_status->flag & RX_FLAG_HT) && 155 !(rx_status->flag & RX_FLAG_VHT)) 156 bss->beacon_rate = 157 &sband->bitrates[rx_status->rate_idx]; 158 } 159 160 return bss; 161} 162 163void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 164{ 165 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 166 struct ieee80211_sub_if_data *sdata1, *sdata2; 167 struct ieee80211_mgmt *mgmt = (void *)skb->data; 168 struct ieee80211_bss *bss; 169 u8 *elements; 170 struct ieee80211_channel *channel; 171 size_t baselen; 172 struct ieee802_11_elems elems; 173 174 if (skb->len < 24 || 175 (!ieee80211_is_probe_resp(mgmt->frame_control) && 176 !ieee80211_is_beacon(mgmt->frame_control))) 177 return; 178 179 sdata1 = rcu_dereference(local->scan_sdata); 180 sdata2 = rcu_dereference(local->sched_scan_sdata); 181 182 if (likely(!sdata1 && !sdata2)) 183 return; 184 185 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 186 /* ignore ProbeResp to foreign address */ 187 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) && 188 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr))) 189 return; 190 191 elements = mgmt->u.probe_resp.variable; 192 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 193 } else { 194 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 195 elements = mgmt->u.beacon.variable; 196 } 197 198 if (baselen > skb->len) 199 return; 200 201 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 202 203 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 204 205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 206 return; 207 208 bss = ieee80211_bss_info_update(local, rx_status, 209 mgmt, skb->len, &elems, 210 channel); 211 if (bss) 212 ieee80211_rx_bss_put(local, bss); 213} 214 215static void 216ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, 217 enum nl80211_bss_scan_width scan_width) 218{ 219 memset(chandef, 0, sizeof(*chandef)); 220 switch (scan_width) { 221 case NL80211_BSS_CHAN_WIDTH_5: 222 chandef->width = NL80211_CHAN_WIDTH_5; 223 break; 224 case NL80211_BSS_CHAN_WIDTH_10: 225 chandef->width = NL80211_CHAN_WIDTH_10; 226 break; 227 default: 228 chandef->width = NL80211_CHAN_WIDTH_20_NOHT; 229 break; 230 } 231} 232 233/* return false if no more work */ 234static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 235{ 236 struct cfg80211_scan_request *req = local->scan_req; 237 struct cfg80211_chan_def chandef; 238 u8 bands_used = 0; 239 int i, ielen, n_chans; 240 241 if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) 242 return false; 243 244 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 245 for (i = 0; i < req->n_channels; i++) { 246 local->hw_scan_req->req.channels[i] = req->channels[i]; 247 bands_used |= BIT(req->channels[i]->band); 248 } 249 250 n_chans = req->n_channels; 251 } else { 252 do { 253 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 254 return false; 255 256 n_chans = 0; 257 258 for (i = 0; i < req->n_channels; i++) { 259 if (req->channels[i]->band != 260 local->hw_scan_band) 261 continue; 262 local->hw_scan_req->req.channels[n_chans] = 263 req->channels[i]; 264 n_chans++; 265 bands_used |= BIT(req->channels[i]->band); 266 } 267 268 local->hw_scan_band++; 269 } while (!n_chans); 270 } 271 272 local->hw_scan_req->req.n_channels = n_chans; 273 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 274 275 ielen = ieee80211_build_preq_ies(local, 276 (u8 *)local->hw_scan_req->req.ie, 277 local->hw_scan_ies_bufsize, 278 &local->hw_scan_req->ies, 279 req->ie, req->ie_len, 280 bands_used, req->rates, &chandef); 281 local->hw_scan_req->req.ie_len = ielen; 282 local->hw_scan_req->req.no_cck = req->no_cck; 283 284 return true; 285} 286 287static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 288{ 289 struct ieee80211_local *local = hw_to_local(hw); 290 bool hw_scan = local->ops->hw_scan; 291 bool was_scanning = local->scanning; 292 293 lockdep_assert_held(&local->mtx); 294 295 /* 296 * It's ok to abort a not-yet-running scan (that 297 * we have one at all will be verified by checking 298 * local->scan_req next), but not to complete it 299 * successfully. 300 */ 301 if (WARN_ON(!local->scanning && !aborted)) 302 aborted = true; 303 304 if (WARN_ON(!local->scan_req)) 305 return; 306 307 if (hw_scan && !aborted && 308 !(local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) && 309 ieee80211_prep_hw_scan(local)) { 310 int rc; 311 312 rc = drv_hw_scan(local, 313 rcu_dereference_protected(local->scan_sdata, 314 lockdep_is_held(&local->mtx)), 315 local->hw_scan_req); 316 317 if (rc == 0) 318 return; 319 } 320 321 kfree(local->hw_scan_req); 322 local->hw_scan_req = NULL; 323 324 if (local->scan_req != local->int_scan_req) 325 cfg80211_scan_done(local->scan_req, aborted); 326 local->scan_req = NULL; 327 RCU_INIT_POINTER(local->scan_sdata, NULL); 328 329 local->scanning = 0; 330 local->scan_chandef.chan = NULL; 331 332 /* Set power back to normal operating levels. */ 333 ieee80211_hw_config(local, 0); 334 335 if (!hw_scan) { 336 ieee80211_configure_filter(local); 337 drv_sw_scan_complete(local); 338 ieee80211_offchannel_return(local); 339 } 340 341 ieee80211_recalc_idle(local); 342 343 ieee80211_mlme_notify_scan_completed(local); 344 ieee80211_ibss_notify_scan_completed(local); 345 ieee80211_mesh_notify_scan_completed(local); 346 if (was_scanning) 347 ieee80211_start_next_roc(local); 348} 349 350void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 351{ 352 struct ieee80211_local *local = hw_to_local(hw); 353 354 trace_api_scan_completed(local, aborted); 355 356 set_bit(SCAN_COMPLETED, &local->scanning); 357 if (aborted) 358 set_bit(SCAN_ABORTED, &local->scanning); 359 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 360} 361EXPORT_SYMBOL(ieee80211_scan_completed); 362 363static int ieee80211_start_sw_scan(struct ieee80211_local *local) 364{ 365 /* Software scan is not supported in multi-channel cases */ 366 if (local->use_chanctx) 367 return -EOPNOTSUPP; 368 369 /* 370 * Hardware/driver doesn't support hw_scan, so use software 371 * scanning instead. First send a nullfunc frame with power save 372 * bit on so that AP will buffer the frames for us while we are not 373 * listening, then send probe requests to each channel and wait for 374 * the responses. After all channels are scanned, tune back to the 375 * original channel and send a nullfunc frame with power save bit 376 * off to trigger the AP to send us all the buffered frames. 377 * 378 * Note that while local->sw_scanning is true everything else but 379 * nullfunc frames and probe requests will be dropped in 380 * ieee80211_tx_h_check_assoc(). 381 */ 382 drv_sw_scan_start(local); 383 384 local->leave_oper_channel_time = jiffies; 385 local->next_scan_state = SCAN_DECISION; 386 local->scan_channel_idx = 0; 387 388 ieee80211_offchannel_stop_vifs(local); 389 390 /* ensure nullfunc is transmitted before leaving operating channel */ 391 ieee80211_flush_queues(local, NULL); 392 393 ieee80211_configure_filter(local); 394 395 /* We need to set power level at maximum rate for scanning. */ 396 ieee80211_hw_config(local, 0); 397 398 ieee80211_queue_delayed_work(&local->hw, 399 &local->scan_work, 0); 400 401 return 0; 402} 403 404static bool ieee80211_can_scan(struct ieee80211_local *local, 405 struct ieee80211_sub_if_data *sdata) 406{ 407 if (local->radar_detect_enabled) 408 return false; 409 410 if (!list_empty(&local->roc_list)) 411 return false; 412 413 if (sdata->vif.type == NL80211_IFTYPE_STATION && 414 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) 415 return false; 416 417 return true; 418} 419 420void ieee80211_run_deferred_scan(struct ieee80211_local *local) 421{ 422 lockdep_assert_held(&local->mtx); 423 424 if (!local->scan_req || local->scanning) 425 return; 426 427 if (!ieee80211_can_scan(local, 428 rcu_dereference_protected( 429 local->scan_sdata, 430 lockdep_is_held(&local->mtx)))) 431 return; 432 433 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 434 round_jiffies_relative(0)); 435} 436 437static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 438 unsigned long *next_delay) 439{ 440 int i; 441 struct ieee80211_sub_if_data *sdata; 442 enum ieee80211_band band = local->hw.conf.chandef.chan->band; 443 u32 tx_flags; 444 445 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 446 if (local->scan_req->no_cck) 447 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 448 449 sdata = rcu_dereference_protected(local->scan_sdata, 450 lockdep_is_held(&local->mtx)); 451 452 for (i = 0; i < local->scan_req->n_ssids; i++) 453 ieee80211_send_probe_req( 454 sdata, NULL, 455 local->scan_req->ssids[i].ssid, 456 local->scan_req->ssids[i].ssid_len, 457 local->scan_req->ie, local->scan_req->ie_len, 458 local->scan_req->rates[band], false, 459 tx_flags, local->hw.conf.chandef.chan, true); 460 461 /* 462 * After sending probe requests, wait for probe responses 463 * on the channel. 464 */ 465 *next_delay = IEEE80211_CHANNEL_TIME; 466 local->next_scan_state = SCAN_DECISION; 467} 468 469static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 470 struct cfg80211_scan_request *req) 471{ 472 struct ieee80211_local *local = sdata->local; 473 int rc; 474 475 lockdep_assert_held(&local->mtx); 476 477 if (local->scan_req) 478 return -EBUSY; 479 480 if (!ieee80211_can_scan(local, sdata)) { 481 /* wait for the work to finish/time out */ 482 local->scan_req = req; 483 rcu_assign_pointer(local->scan_sdata, sdata); 484 return 0; 485 } 486 487 if (local->ops->hw_scan) { 488 u8 *ies; 489 490 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; 491 492 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 493 int i, n_bands = 0; 494 u8 bands_counted = 0; 495 496 for (i = 0; i < req->n_channels; i++) { 497 if (bands_counted & BIT(req->channels[i]->band)) 498 continue; 499 bands_counted |= BIT(req->channels[i]->band); 500 n_bands++; 501 } 502 503 local->hw_scan_ies_bufsize *= n_bands; 504 } 505 506 local->hw_scan_req = kmalloc( 507 sizeof(*local->hw_scan_req) + 508 req->n_channels * sizeof(req->channels[0]) + 509 local->hw_scan_ies_bufsize, GFP_KERNEL); 510 if (!local->hw_scan_req) 511 return -ENOMEM; 512 513 local->hw_scan_req->req.ssids = req->ssids; 514 local->hw_scan_req->req.n_ssids = req->n_ssids; 515 ies = (u8 *)local->hw_scan_req + 516 sizeof(*local->hw_scan_req) + 517 req->n_channels * sizeof(req->channels[0]); 518 local->hw_scan_req->req.ie = ies; 519 local->hw_scan_req->req.flags = req->flags; 520 521 local->hw_scan_band = 0; 522 523 /* 524 * After allocating local->hw_scan_req, we must 525 * go through until ieee80211_prep_hw_scan(), so 526 * anything that might be changed here and leave 527 * this function early must not go after this 528 * allocation. 529 */ 530 } 531 532 local->scan_req = req; 533 rcu_assign_pointer(local->scan_sdata, sdata); 534 535 if (local->ops->hw_scan) { 536 __set_bit(SCAN_HW_SCANNING, &local->scanning); 537 } else if ((req->n_channels == 1) && 538 (req->channels[0] == local->_oper_chandef.chan)) { 539 /* 540 * If we are scanning only on the operating channel 541 * then we do not need to stop normal activities 542 */ 543 unsigned long next_delay; 544 545 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 546 547 ieee80211_recalc_idle(local); 548 549 /* Notify driver scan is starting, keep order of operations 550 * same as normal software scan, in case that matters. */ 551 drv_sw_scan_start(local); 552 553 ieee80211_configure_filter(local); /* accept probe-responses */ 554 555 /* We need to ensure power level is at max for scanning. */ 556 ieee80211_hw_config(local, 0); 557 558 if ((req->channels[0]->flags & 559 IEEE80211_CHAN_NO_IR) || 560 !local->scan_req->n_ssids) { 561 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 562 } else { 563 ieee80211_scan_state_send_probe(local, &next_delay); 564 next_delay = IEEE80211_CHANNEL_TIME; 565 } 566 567 /* Now, just wait a bit and we are all done! */ 568 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 569 next_delay); 570 return 0; 571 } else { 572 /* Do normal software scan */ 573 __set_bit(SCAN_SW_SCANNING, &local->scanning); 574 } 575 576 ieee80211_recalc_idle(local); 577 578 if (local->ops->hw_scan) { 579 WARN_ON(!ieee80211_prep_hw_scan(local)); 580 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 581 } else 582 rc = ieee80211_start_sw_scan(local); 583 584 if (rc) { 585 kfree(local->hw_scan_req); 586 local->hw_scan_req = NULL; 587 local->scanning = 0; 588 589 ieee80211_recalc_idle(local); 590 591 local->scan_req = NULL; 592 RCU_INIT_POINTER(local->scan_sdata, NULL); 593 } 594 595 return rc; 596} 597 598static unsigned long 599ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 600{ 601 /* 602 * TODO: channel switching also consumes quite some time, 603 * add that delay as well to get a better estimation 604 */ 605 if (chan->flags & IEEE80211_CHAN_NO_IR) 606 return IEEE80211_PASSIVE_CHANNEL_TIME; 607 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 608} 609 610static void ieee80211_scan_state_decision(struct ieee80211_local *local, 611 unsigned long *next_delay) 612{ 613 bool associated = false; 614 bool tx_empty = true; 615 bool bad_latency; 616 struct ieee80211_sub_if_data *sdata; 617 struct ieee80211_channel *next_chan; 618 enum mac80211_scan_state next_scan_state; 619 620 /* 621 * check if at least one STA interface is associated, 622 * check if at least one STA interface has pending tx frames 623 * and grab the lowest used beacon interval 624 */ 625 mutex_lock(&local->iflist_mtx); 626 list_for_each_entry(sdata, &local->interfaces, list) { 627 if (!ieee80211_sdata_running(sdata)) 628 continue; 629 630 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 631 if (sdata->u.mgd.associated) { 632 associated = true; 633 634 if (!qdisc_all_tx_empty(sdata->dev)) { 635 tx_empty = false; 636 break; 637 } 638 } 639 } 640 } 641 mutex_unlock(&local->iflist_mtx); 642 643 next_chan = local->scan_req->channels[local->scan_channel_idx]; 644 645 /* 646 * we're currently scanning a different channel, let's 647 * see if we can scan another channel without interfering 648 * with the current traffic situation. 649 * 650 * Keep good latency, do not stay off-channel more than 125 ms. 651 */ 652 653 bad_latency = time_after(jiffies + 654 ieee80211_scan_get_channel_time(next_chan), 655 local->leave_oper_channel_time + HZ / 8); 656 657 if (associated && !tx_empty) { 658 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 659 next_scan_state = SCAN_ABORT; 660 else 661 next_scan_state = SCAN_SUSPEND; 662 } else if (associated && bad_latency) { 663 next_scan_state = SCAN_SUSPEND; 664 } else { 665 next_scan_state = SCAN_SET_CHANNEL; 666 } 667 668 local->next_scan_state = next_scan_state; 669 670 *next_delay = 0; 671} 672 673static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 674 unsigned long *next_delay) 675{ 676 int skip; 677 struct ieee80211_channel *chan; 678 enum nl80211_bss_scan_width oper_scan_width; 679 680 skip = 0; 681 chan = local->scan_req->channels[local->scan_channel_idx]; 682 683 local->scan_chandef.chan = chan; 684 local->scan_chandef.center_freq1 = chan->center_freq; 685 local->scan_chandef.center_freq2 = 0; 686 switch (local->scan_req->scan_width) { 687 case NL80211_BSS_CHAN_WIDTH_5: 688 local->scan_chandef.width = NL80211_CHAN_WIDTH_5; 689 break; 690 case NL80211_BSS_CHAN_WIDTH_10: 691 local->scan_chandef.width = NL80211_CHAN_WIDTH_10; 692 break; 693 case NL80211_BSS_CHAN_WIDTH_20: 694 /* If scanning on oper channel, use whatever channel-type 695 * is currently in use. 696 */ 697 oper_scan_width = cfg80211_chandef_to_scan_width( 698 &local->_oper_chandef); 699 if (chan == local->_oper_chandef.chan && 700 oper_scan_width == local->scan_req->scan_width) 701 local->scan_chandef = local->_oper_chandef; 702 else 703 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; 704 break; 705 } 706 707 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 708 skip = 1; 709 710 /* advance state machine to next channel/band */ 711 local->scan_channel_idx++; 712 713 if (skip) { 714 /* if we skip this channel return to the decision state */ 715 local->next_scan_state = SCAN_DECISION; 716 return; 717 } 718 719 /* 720 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 721 * (which unfortunately doesn't say _why_ step a) is done, 722 * but it waits for the probe delay or until a frame is 723 * received - and the received frame would update the NAV). 724 * For now, we do not support waiting until a frame is 725 * received. 726 * 727 * In any case, it is not necessary for a passive scan. 728 */ 729 if (chan->flags & IEEE80211_CHAN_NO_IR || 730 !local->scan_req->n_ssids) { 731 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 732 local->next_scan_state = SCAN_DECISION; 733 return; 734 } 735 736 /* active scan, send probes */ 737 *next_delay = IEEE80211_PROBE_DELAY; 738 local->next_scan_state = SCAN_SEND_PROBE; 739} 740 741static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 742 unsigned long *next_delay) 743{ 744 /* switch back to the operating channel */ 745 local->scan_chandef.chan = NULL; 746 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 747 748 /* disable PS */ 749 ieee80211_offchannel_return(local); 750 751 *next_delay = HZ / 5; 752 /* afterwards, resume scan & go to next channel */ 753 local->next_scan_state = SCAN_RESUME; 754} 755 756static void ieee80211_scan_state_resume(struct ieee80211_local *local, 757 unsigned long *next_delay) 758{ 759 ieee80211_offchannel_stop_vifs(local); 760 761 if (local->ops->flush) { 762 ieee80211_flush_queues(local, NULL); 763 *next_delay = 0; 764 } else 765 *next_delay = HZ / 10; 766 767 /* remember when we left the operating channel */ 768 local->leave_oper_channel_time = jiffies; 769 770 /* advance to the next channel to be scanned */ 771 local->next_scan_state = SCAN_SET_CHANNEL; 772} 773 774void ieee80211_scan_work(struct work_struct *work) 775{ 776 struct ieee80211_local *local = 777 container_of(work, struct ieee80211_local, scan_work.work); 778 struct ieee80211_sub_if_data *sdata; 779 unsigned long next_delay = 0; 780 bool aborted; 781 782 mutex_lock(&local->mtx); 783 784 sdata = rcu_dereference_protected(local->scan_sdata, 785 lockdep_is_held(&local->mtx)); 786 787 /* When scanning on-channel, the first-callback means completed. */ 788 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 789 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 790 goto out_complete; 791 } 792 793 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 794 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 795 goto out_complete; 796 } 797 798 if (!sdata || !local->scan_req) 799 goto out; 800 801 if (local->scan_req && !local->scanning) { 802 struct cfg80211_scan_request *req = local->scan_req; 803 int rc; 804 805 local->scan_req = NULL; 806 RCU_INIT_POINTER(local->scan_sdata, NULL); 807 808 rc = __ieee80211_start_scan(sdata, req); 809 if (rc) { 810 /* need to complete scan in cfg80211 */ 811 local->scan_req = req; 812 aborted = true; 813 goto out_complete; 814 } else 815 goto out; 816 } 817 818 /* 819 * as long as no delay is required advance immediately 820 * without scheduling a new work 821 */ 822 do { 823 if (!ieee80211_sdata_running(sdata)) { 824 aborted = true; 825 goto out_complete; 826 } 827 828 switch (local->next_scan_state) { 829 case SCAN_DECISION: 830 /* if no more bands/channels left, complete scan */ 831 if (local->scan_channel_idx >= local->scan_req->n_channels) { 832 aborted = false; 833 goto out_complete; 834 } 835 ieee80211_scan_state_decision(local, &next_delay); 836 break; 837 case SCAN_SET_CHANNEL: 838 ieee80211_scan_state_set_channel(local, &next_delay); 839 break; 840 case SCAN_SEND_PROBE: 841 ieee80211_scan_state_send_probe(local, &next_delay); 842 break; 843 case SCAN_SUSPEND: 844 ieee80211_scan_state_suspend(local, &next_delay); 845 break; 846 case SCAN_RESUME: 847 ieee80211_scan_state_resume(local, &next_delay); 848 break; 849 case SCAN_ABORT: 850 aborted = true; 851 goto out_complete; 852 } 853 } while (next_delay == 0); 854 855 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 856 goto out; 857 858out_complete: 859 __ieee80211_scan_completed(&local->hw, aborted); 860out: 861 mutex_unlock(&local->mtx); 862} 863 864int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 865 struct cfg80211_scan_request *req) 866{ 867 int res; 868 869 mutex_lock(&sdata->local->mtx); 870 res = __ieee80211_start_scan(sdata, req); 871 mutex_unlock(&sdata->local->mtx); 872 873 return res; 874} 875 876int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 877 const u8 *ssid, u8 ssid_len, 878 struct ieee80211_channel *chan, 879 enum nl80211_bss_scan_width scan_width) 880{ 881 struct ieee80211_local *local = sdata->local; 882 int ret = -EBUSY; 883 enum ieee80211_band band; 884 885 mutex_lock(&local->mtx); 886 887 /* busy scanning */ 888 if (local->scan_req) 889 goto unlock; 890 891 /* fill internal scan request */ 892 if (!chan) { 893 int i, max_n; 894 int n_ch = 0; 895 896 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 897 if (!local->hw.wiphy->bands[band]) 898 continue; 899 900 max_n = local->hw.wiphy->bands[band]->n_channels; 901 for (i = 0; i < max_n; i++) { 902 struct ieee80211_channel *tmp_ch = 903 &local->hw.wiphy->bands[band]->channels[i]; 904 905 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | 906 IEEE80211_CHAN_DISABLED)) 907 continue; 908 909 local->int_scan_req->channels[n_ch] = tmp_ch; 910 n_ch++; 911 } 912 } 913 914 if (WARN_ON_ONCE(n_ch == 0)) 915 goto unlock; 916 917 local->int_scan_req->n_channels = n_ch; 918 } else { 919 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR | 920 IEEE80211_CHAN_DISABLED))) 921 goto unlock; 922 923 local->int_scan_req->channels[0] = chan; 924 local->int_scan_req->n_channels = 1; 925 } 926 927 local->int_scan_req->ssids = &local->scan_ssid; 928 local->int_scan_req->n_ssids = 1; 929 local->int_scan_req->scan_width = scan_width; 930 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 931 local->int_scan_req->ssids[0].ssid_len = ssid_len; 932 933 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 934 unlock: 935 mutex_unlock(&local->mtx); 936 return ret; 937} 938 939/* 940 * Only call this function when a scan can't be queued -- under RTNL. 941 */ 942void ieee80211_scan_cancel(struct ieee80211_local *local) 943{ 944 /* 945 * We are canceling software scan, or deferred scan that was not 946 * yet really started (see __ieee80211_start_scan ). 947 * 948 * Regarding hardware scan: 949 * - we can not call __ieee80211_scan_completed() as when 950 * SCAN_HW_SCANNING bit is set this function change 951 * local->hw_scan_req to operate on 5G band, what race with 952 * driver which can use local->hw_scan_req 953 * 954 * - we can not cancel scan_work since driver can schedule it 955 * by ieee80211_scan_completed(..., true) to finish scan 956 * 957 * Hence we only call the cancel_hw_scan() callback, but the low-level 958 * driver is still responsible for calling ieee80211_scan_completed() 959 * after the scan was completed/aborted. 960 */ 961 962 mutex_lock(&local->mtx); 963 if (!local->scan_req) 964 goto out; 965 966 /* 967 * We have a scan running and the driver already reported completion, 968 * but the worker hasn't run yet or is stuck on the mutex - mark it as 969 * cancelled. 970 */ 971 if (test_bit(SCAN_HW_SCANNING, &local->scanning) && 972 test_bit(SCAN_COMPLETED, &local->scanning)) { 973 set_bit(SCAN_HW_CANCELLED, &local->scanning); 974 goto out; 975 } 976 977 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 978 /* 979 * Make sure that __ieee80211_scan_completed doesn't trigger a 980 * scan on another band. 981 */ 982 set_bit(SCAN_HW_CANCELLED, &local->scanning); 983 if (local->ops->cancel_hw_scan) 984 drv_cancel_hw_scan(local, 985 rcu_dereference_protected(local->scan_sdata, 986 lockdep_is_held(&local->mtx))); 987 goto out; 988 } 989 990 /* 991 * If the work is currently running, it must be blocked on 992 * the mutex, but we'll set scan_sdata = NULL and it'll 993 * simply exit once it acquires the mutex. 994 */ 995 cancel_delayed_work(&local->scan_work); 996 /* and clean up */ 997 __ieee80211_scan_completed(&local->hw, true); 998out: 999 mutex_unlock(&local->mtx); 1000} 1001 1002int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1003 struct cfg80211_sched_scan_request *req) 1004{ 1005 struct ieee80211_local *local = sdata->local; 1006 struct ieee80211_sched_scan_ies sched_scan_ies = {}; 1007 struct cfg80211_chan_def chandef; 1008 int ret, i, iebufsz; 1009 struct ieee80211_scan_ies dummy_ie_desc; 1010 1011 iebufsz = local->scan_ies_len + req->ie_len; 1012 1013 lockdep_assert_held(&local->mtx); 1014 1015 if (!local->ops->sched_scan_start) 1016 return -ENOTSUPP; 1017 1018 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 1019 u32 rate_masks[IEEE80211_NUM_BANDS] = {}; 1020 1021 if (!local->hw.wiphy->bands[i]) 1022 continue; 1023 1024 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL); 1025 if (!sched_scan_ies.ie[i]) { 1026 ret = -ENOMEM; 1027 goto out_free; 1028 } 1029 1030 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 1031 rate_masks[i] = (u32) -1; 1032 1033 sched_scan_ies.len[i] = 1034 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i], 1035 iebufsz, &dummy_ie_desc, 1036 req->ie, req->ie_len, BIT(i), 1037 rate_masks, &chandef); 1038 } 1039 1040 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 1041 if (ret == 0) { 1042 rcu_assign_pointer(local->sched_scan_sdata, sdata); 1043 local->sched_scan_req = req; 1044 } 1045 1046out_free: 1047 while (i > 0) 1048 kfree(sched_scan_ies.ie[--i]); 1049 1050 if (ret) { 1051 /* Clean in case of failure after HW restart or upon resume. */ 1052 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1053 local->sched_scan_req = NULL; 1054 } 1055 1056 return ret; 1057} 1058 1059int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1060 struct cfg80211_sched_scan_request *req) 1061{ 1062 struct ieee80211_local *local = sdata->local; 1063 int ret; 1064 1065 mutex_lock(&local->mtx); 1066 1067 if (rcu_access_pointer(local->sched_scan_sdata)) { 1068 mutex_unlock(&local->mtx); 1069 return -EBUSY; 1070 } 1071 1072 ret = __ieee80211_request_sched_scan_start(sdata, req); 1073 1074 mutex_unlock(&local->mtx); 1075 return ret; 1076} 1077 1078int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 1079{ 1080 struct ieee80211_local *local = sdata->local; 1081 int ret = 0; 1082 1083 mutex_lock(&local->mtx); 1084 1085 if (!local->ops->sched_scan_stop) { 1086 ret = -ENOTSUPP; 1087 goto out; 1088 } 1089 1090 /* We don't want to restart sched scan anymore. */ 1091 local->sched_scan_req = NULL; 1092 1093 if (rcu_access_pointer(local->sched_scan_sdata)) { 1094 ret = drv_sched_scan_stop(local, sdata); 1095 if (!ret) 1096 rcu_assign_pointer(local->sched_scan_sdata, NULL); 1097 } 1098out: 1099 mutex_unlock(&local->mtx); 1100 1101 return ret; 1102} 1103 1104void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 1105{ 1106 struct ieee80211_local *local = hw_to_local(hw); 1107 1108 trace_api_sched_scan_results(local); 1109 1110 cfg80211_sched_scan_results(hw->wiphy); 1111} 1112EXPORT_SYMBOL(ieee80211_sched_scan_results); 1113 1114void ieee80211_sched_scan_end(struct ieee80211_local *local) 1115{ 1116 mutex_lock(&local->mtx); 1117 1118 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1119 mutex_unlock(&local->mtx); 1120 return; 1121 } 1122 1123 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1124 1125 /* If sched scan was aborted by the driver. */ 1126 local->sched_scan_req = NULL; 1127 1128 mutex_unlock(&local->mtx); 1129 1130 cfg80211_sched_scan_stopped(local->hw.wiphy); 1131} 1132 1133void ieee80211_sched_scan_stopped_work(struct work_struct *work) 1134{ 1135 struct ieee80211_local *local = 1136 container_of(work, struct ieee80211_local, 1137 sched_scan_stopped_work); 1138 1139 ieee80211_sched_scan_end(local); 1140} 1141 1142void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1143{ 1144 struct ieee80211_local *local = hw_to_local(hw); 1145 1146 trace_api_sched_scan_stopped(local); 1147 1148 schedule_work(&local->sched_scan_stopped_work); 1149} 1150EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1151