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 33void 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 42static 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 59struct ieee80211_bss * 60ieee80211_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 164void 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 struct cfg80211_scan_request *scan_req; 188 struct cfg80211_sched_scan_request *sched_scan_req; 189 190 scan_req = rcu_dereference(local->scan_req); 191 sched_scan_req = rcu_dereference(local->sched_scan_req); 192 193 /* ignore ProbeResp to foreign address unless scanning 194 * with randomised address 195 */ 196 if (!(sdata1 && 197 (ether_addr_equal(mgmt->da, sdata1->vif.addr) || 198 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) && 199 !(sdata2 && 200 (ether_addr_equal(mgmt->da, sdata2->vif.addr) || 201 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR))) 202 return; 203 204 elements = mgmt->u.probe_resp.variable; 205 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 206 } else { 207 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 208 elements = mgmt->u.beacon.variable; 209 } 210 211 if (baselen > skb->len) 212 return; 213 214 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 215 216 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 217 218 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 219 return; 220 221 bss = ieee80211_bss_info_update(local, rx_status, 222 mgmt, skb->len, &elems, 223 channel); 224 if (bss) 225 ieee80211_rx_bss_put(local, bss); 226} 227 228static void 229ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, 230 enum nl80211_bss_scan_width scan_width) 231{ 232 memset(chandef, 0, sizeof(*chandef)); 233 switch (scan_width) { 234 case NL80211_BSS_CHAN_WIDTH_5: 235 chandef->width = NL80211_CHAN_WIDTH_5; 236 break; 237 case NL80211_BSS_CHAN_WIDTH_10: 238 chandef->width = NL80211_CHAN_WIDTH_10; 239 break; 240 default: 241 chandef->width = NL80211_CHAN_WIDTH_20_NOHT; 242 break; 243 } 244} 245 246/* return false if no more work */ 247static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 248{ 249 struct cfg80211_scan_request *req; 250 struct cfg80211_chan_def chandef; 251 u8 bands_used = 0; 252 int i, ielen, n_chans; 253 254 req = rcu_dereference_protected(local->scan_req, 255 lockdep_is_held(&local->mtx)); 256 257 if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) 258 return false; 259 260 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 261 for (i = 0; i < req->n_channels; i++) { 262 local->hw_scan_req->req.channels[i] = req->channels[i]; 263 bands_used |= BIT(req->channels[i]->band); 264 } 265 266 n_chans = req->n_channels; 267 } else { 268 do { 269 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 270 return false; 271 272 n_chans = 0; 273 274 for (i = 0; i < req->n_channels; i++) { 275 if (req->channels[i]->band != 276 local->hw_scan_band) 277 continue; 278 local->hw_scan_req->req.channels[n_chans] = 279 req->channels[i]; 280 n_chans++; 281 bands_used |= BIT(req->channels[i]->band); 282 } 283 284 local->hw_scan_band++; 285 } while (!n_chans); 286 } 287 288 local->hw_scan_req->req.n_channels = n_chans; 289 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 290 291 ielen = ieee80211_build_preq_ies(local, 292 (u8 *)local->hw_scan_req->req.ie, 293 local->hw_scan_ies_bufsize, 294 &local->hw_scan_req->ies, 295 req->ie, req->ie_len, 296 bands_used, req->rates, &chandef); 297 local->hw_scan_req->req.ie_len = ielen; 298 local->hw_scan_req->req.no_cck = req->no_cck; 299 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr); 300 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask, 301 req->mac_addr_mask); 302 303 return true; 304} 305 306static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 307{ 308 struct ieee80211_local *local = hw_to_local(hw); 309 bool hw_scan = local->ops->hw_scan; 310 bool was_scanning = local->scanning; 311 struct cfg80211_scan_request *scan_req; 312 struct ieee80211_sub_if_data *scan_sdata; 313 struct ieee80211_sub_if_data *sdata; 314 315 lockdep_assert_held(&local->mtx); 316 317 /* 318 * It's ok to abort a not-yet-running scan (that 319 * we have one at all will be verified by checking 320 * local->scan_req next), but not to complete it 321 * successfully. 322 */ 323 if (WARN_ON(!local->scanning && !aborted)) 324 aborted = true; 325 326 if (WARN_ON(!local->scan_req)) 327 return; 328 329 if (hw_scan && !aborted && 330 !(local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) && 331 ieee80211_prep_hw_scan(local)) { 332 int rc; 333 334 rc = drv_hw_scan(local, 335 rcu_dereference_protected(local->scan_sdata, 336 lockdep_is_held(&local->mtx)), 337 local->hw_scan_req); 338 339 if (rc == 0) 340 return; 341 } 342 343 kfree(local->hw_scan_req); 344 local->hw_scan_req = NULL; 345 346 scan_req = rcu_dereference_protected(local->scan_req, 347 lockdep_is_held(&local->mtx)); 348 349 if (scan_req != local->int_scan_req) 350 cfg80211_scan_done(scan_req, aborted); 351 RCU_INIT_POINTER(local->scan_req, NULL); 352 353 scan_sdata = rcu_dereference_protected(local->scan_sdata, 354 lockdep_is_held(&local->mtx)); 355 RCU_INIT_POINTER(local->scan_sdata, NULL); 356 357 local->scanning = 0; 358 local->scan_chandef.chan = NULL; 359 360 /* Set power back to normal operating levels. */ 361 ieee80211_hw_config(local, 0); 362 363 if (!hw_scan) { 364 ieee80211_configure_filter(local); 365 drv_sw_scan_complete(local, scan_sdata); 366 ieee80211_offchannel_return(local); 367 } 368 369 ieee80211_recalc_idle(local); 370 371 ieee80211_mlme_notify_scan_completed(local); 372 ieee80211_ibss_notify_scan_completed(local); 373 374 /* Requeue all the work that might have been ignored while 375 * the scan was in progress; if there was none this will 376 * just be a no-op for the particular interface. 377 */ 378 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 379 if (ieee80211_sdata_running(sdata)) 380 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 381 } 382 383 if (was_scanning) 384 ieee80211_start_next_roc(local); 385} 386 387void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 388{ 389 struct ieee80211_local *local = hw_to_local(hw); 390 391 trace_api_scan_completed(local, aborted); 392 393 set_bit(SCAN_COMPLETED, &local->scanning); 394 if (aborted) 395 set_bit(SCAN_ABORTED, &local->scanning); 396 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 397} 398EXPORT_SYMBOL(ieee80211_scan_completed); 399 400static int ieee80211_start_sw_scan(struct ieee80211_local *local, 401 struct ieee80211_sub_if_data *sdata) 402{ 403 /* Software scan is not supported in multi-channel cases */ 404 if (local->use_chanctx) 405 return -EOPNOTSUPP; 406 407 /* 408 * Hardware/driver doesn't support hw_scan, so use software 409 * scanning instead. First send a nullfunc frame with power save 410 * bit on so that AP will buffer the frames for us while we are not 411 * listening, then send probe requests to each channel and wait for 412 * the responses. After all channels are scanned, tune back to the 413 * original channel and send a nullfunc frame with power save bit 414 * off to trigger the AP to send us all the buffered frames. 415 * 416 * Note that while local->sw_scanning is true everything else but 417 * nullfunc frames and probe requests will be dropped in 418 * ieee80211_tx_h_check_assoc(). 419 */ 420 drv_sw_scan_start(local, sdata, local->scan_addr); 421 422 local->leave_oper_channel_time = jiffies; 423 local->next_scan_state = SCAN_DECISION; 424 local->scan_channel_idx = 0; 425 426 ieee80211_offchannel_stop_vifs(local); 427 428 /* ensure nullfunc is transmitted before leaving operating channel */ 429 ieee80211_flush_queues(local, NULL, false); 430 431 ieee80211_configure_filter(local); 432 433 /* We need to set power level at maximum rate for scanning. */ 434 ieee80211_hw_config(local, 0); 435 436 ieee80211_queue_delayed_work(&local->hw, 437 &local->scan_work, 0); 438 439 return 0; 440} 441 442static bool ieee80211_can_scan(struct ieee80211_local *local, 443 struct ieee80211_sub_if_data *sdata) 444{ 445 if (ieee80211_is_radar_required(local)) 446 return false; 447 448 if (!list_empty(&local->roc_list)) 449 return false; 450 451 if (sdata->vif.type == NL80211_IFTYPE_STATION && 452 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) 453 return false; 454 455 return true; 456} 457 458void ieee80211_run_deferred_scan(struct ieee80211_local *local) 459{ 460 lockdep_assert_held(&local->mtx); 461 462 if (!local->scan_req || local->scanning) 463 return; 464 465 if (!ieee80211_can_scan(local, 466 rcu_dereference_protected( 467 local->scan_sdata, 468 lockdep_is_held(&local->mtx)))) 469 return; 470 471 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 472 round_jiffies_relative(0)); 473} 474 475static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 476 unsigned long *next_delay) 477{ 478 int i; 479 struct ieee80211_sub_if_data *sdata; 480 struct cfg80211_scan_request *scan_req; 481 enum ieee80211_band band = local->hw.conf.chandef.chan->band; 482 u32 tx_flags; 483 484 scan_req = rcu_dereference_protected(local->scan_req, 485 lockdep_is_held(&local->mtx)); 486 487 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 488 if (scan_req->no_cck) 489 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 490 491 sdata = rcu_dereference_protected(local->scan_sdata, 492 lockdep_is_held(&local->mtx)); 493 494 for (i = 0; i < scan_req->n_ssids; i++) 495 ieee80211_send_probe_req( 496 sdata, local->scan_addr, NULL, 497 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len, 498 scan_req->ie, scan_req->ie_len, 499 scan_req->rates[band], false, 500 tx_flags, local->hw.conf.chandef.chan, true); 501 502 /* 503 * After sending probe requests, wait for probe responses 504 * on the channel. 505 */ 506 *next_delay = IEEE80211_CHANNEL_TIME; 507 local->next_scan_state = SCAN_DECISION; 508} 509 510static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 511 struct cfg80211_scan_request *req) 512{ 513 struct ieee80211_local *local = sdata->local; 514 int rc; 515 516 lockdep_assert_held(&local->mtx); 517 518 if (local->scan_req || ieee80211_is_radar_required(local)) 519 return -EBUSY; 520 521 if (!ieee80211_can_scan(local, sdata)) { 522 /* wait for the work to finish/time out */ 523 rcu_assign_pointer(local->scan_req, req); 524 rcu_assign_pointer(local->scan_sdata, sdata); 525 return 0; 526 } 527 528 if (local->ops->hw_scan) { 529 u8 *ies; 530 531 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; 532 533 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) { 534 int i, n_bands = 0; 535 u8 bands_counted = 0; 536 537 for (i = 0; i < req->n_channels; i++) { 538 if (bands_counted & BIT(req->channels[i]->band)) 539 continue; 540 bands_counted |= BIT(req->channels[i]->band); 541 n_bands++; 542 } 543 544 local->hw_scan_ies_bufsize *= n_bands; 545 } 546 547 local->hw_scan_req = kmalloc( 548 sizeof(*local->hw_scan_req) + 549 req->n_channels * sizeof(req->channels[0]) + 550 local->hw_scan_ies_bufsize, GFP_KERNEL); 551 if (!local->hw_scan_req) 552 return -ENOMEM; 553 554 local->hw_scan_req->req.ssids = req->ssids; 555 local->hw_scan_req->req.n_ssids = req->n_ssids; 556 ies = (u8 *)local->hw_scan_req + 557 sizeof(*local->hw_scan_req) + 558 req->n_channels * sizeof(req->channels[0]); 559 local->hw_scan_req->req.ie = ies; 560 local->hw_scan_req->req.flags = req->flags; 561 562 local->hw_scan_band = 0; 563 564 /* 565 * After allocating local->hw_scan_req, we must 566 * go through until ieee80211_prep_hw_scan(), so 567 * anything that might be changed here and leave 568 * this function early must not go after this 569 * allocation. 570 */ 571 } 572 573 rcu_assign_pointer(local->scan_req, req); 574 rcu_assign_pointer(local->scan_sdata, sdata); 575 576 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) 577 get_random_mask_addr(local->scan_addr, 578 req->mac_addr, 579 req->mac_addr_mask); 580 else 581 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN); 582 583 if (local->ops->hw_scan) { 584 __set_bit(SCAN_HW_SCANNING, &local->scanning); 585 } else if ((req->n_channels == 1) && 586 (req->channels[0] == local->_oper_chandef.chan)) { 587 /* 588 * If we are scanning only on the operating channel 589 * then we do not need to stop normal activities 590 */ 591 unsigned long next_delay; 592 593 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 594 595 ieee80211_recalc_idle(local); 596 597 /* Notify driver scan is starting, keep order of operations 598 * same as normal software scan, in case that matters. */ 599 drv_sw_scan_start(local, sdata, local->scan_addr); 600 601 ieee80211_configure_filter(local); /* accept probe-responses */ 602 603 /* We need to ensure power level is at max for scanning. */ 604 ieee80211_hw_config(local, 0); 605 606 if ((req->channels[0]->flags & 607 IEEE80211_CHAN_NO_IR) || 608 !req->n_ssids) { 609 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 610 } else { 611 ieee80211_scan_state_send_probe(local, &next_delay); 612 next_delay = IEEE80211_CHANNEL_TIME; 613 } 614 615 /* Now, just wait a bit and we are all done! */ 616 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 617 next_delay); 618 return 0; 619 } else { 620 /* Do normal software scan */ 621 __set_bit(SCAN_SW_SCANNING, &local->scanning); 622 } 623 624 ieee80211_recalc_idle(local); 625 626 if (local->ops->hw_scan) { 627 WARN_ON(!ieee80211_prep_hw_scan(local)); 628 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 629 } else { 630 rc = ieee80211_start_sw_scan(local, sdata); 631 } 632 633 if (rc) { 634 kfree(local->hw_scan_req); 635 local->hw_scan_req = NULL; 636 local->scanning = 0; 637 638 ieee80211_recalc_idle(local); 639 640 local->scan_req = NULL; 641 RCU_INIT_POINTER(local->scan_sdata, NULL); 642 } 643 644 return rc; 645} 646 647static unsigned long 648ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 649{ 650 /* 651 * TODO: channel switching also consumes quite some time, 652 * add that delay as well to get a better estimation 653 */ 654 if (chan->flags & IEEE80211_CHAN_NO_IR) 655 return IEEE80211_PASSIVE_CHANNEL_TIME; 656 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 657} 658 659static void ieee80211_scan_state_decision(struct ieee80211_local *local, 660 unsigned long *next_delay) 661{ 662 bool associated = false; 663 bool tx_empty = true; 664 bool bad_latency; 665 struct ieee80211_sub_if_data *sdata; 666 struct ieee80211_channel *next_chan; 667 enum mac80211_scan_state next_scan_state; 668 struct cfg80211_scan_request *scan_req; 669 670 /* 671 * check if at least one STA interface is associated, 672 * check if at least one STA interface has pending tx frames 673 * and grab the lowest used beacon interval 674 */ 675 mutex_lock(&local->iflist_mtx); 676 list_for_each_entry(sdata, &local->interfaces, list) { 677 if (!ieee80211_sdata_running(sdata)) 678 continue; 679 680 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 681 if (sdata->u.mgd.associated) { 682 associated = true; 683 684 if (!qdisc_all_tx_empty(sdata->dev)) { 685 tx_empty = false; 686 break; 687 } 688 } 689 } 690 } 691 mutex_unlock(&local->iflist_mtx); 692 693 scan_req = rcu_dereference_protected(local->scan_req, 694 lockdep_is_held(&local->mtx)); 695 696 next_chan = scan_req->channels[local->scan_channel_idx]; 697 698 /* 699 * we're currently scanning a different channel, let's 700 * see if we can scan another channel without interfering 701 * with the current traffic situation. 702 * 703 * Keep good latency, do not stay off-channel more than 125 ms. 704 */ 705 706 bad_latency = time_after(jiffies + 707 ieee80211_scan_get_channel_time(next_chan), 708 local->leave_oper_channel_time + HZ / 8); 709 710 if (associated && !tx_empty) { 711 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 712 next_scan_state = SCAN_ABORT; 713 else 714 next_scan_state = SCAN_SUSPEND; 715 } else if (associated && bad_latency) { 716 next_scan_state = SCAN_SUSPEND; 717 } else { 718 next_scan_state = SCAN_SET_CHANNEL; 719 } 720 721 local->next_scan_state = next_scan_state; 722 723 *next_delay = 0; 724} 725 726static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 727 unsigned long *next_delay) 728{ 729 int skip; 730 struct ieee80211_channel *chan; 731 enum nl80211_bss_scan_width oper_scan_width; 732 struct cfg80211_scan_request *scan_req; 733 734 scan_req = rcu_dereference_protected(local->scan_req, 735 lockdep_is_held(&local->mtx)); 736 737 skip = 0; 738 chan = scan_req->channels[local->scan_channel_idx]; 739 740 local->scan_chandef.chan = chan; 741 local->scan_chandef.center_freq1 = chan->center_freq; 742 local->scan_chandef.center_freq2 = 0; 743 switch (scan_req->scan_width) { 744 case NL80211_BSS_CHAN_WIDTH_5: 745 local->scan_chandef.width = NL80211_CHAN_WIDTH_5; 746 break; 747 case NL80211_BSS_CHAN_WIDTH_10: 748 local->scan_chandef.width = NL80211_CHAN_WIDTH_10; 749 break; 750 case NL80211_BSS_CHAN_WIDTH_20: 751 /* If scanning on oper channel, use whatever channel-type 752 * is currently in use. 753 */ 754 oper_scan_width = cfg80211_chandef_to_scan_width( 755 &local->_oper_chandef); 756 if (chan == local->_oper_chandef.chan && 757 oper_scan_width == scan_req->scan_width) 758 local->scan_chandef = local->_oper_chandef; 759 else 760 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; 761 break; 762 } 763 764 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 765 skip = 1; 766 767 /* advance state machine to next channel/band */ 768 local->scan_channel_idx++; 769 770 if (skip) { 771 /* if we skip this channel return to the decision state */ 772 local->next_scan_state = SCAN_DECISION; 773 return; 774 } 775 776 /* 777 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 778 * (which unfortunately doesn't say _why_ step a) is done, 779 * but it waits for the probe delay or until a frame is 780 * received - and the received frame would update the NAV). 781 * For now, we do not support waiting until a frame is 782 * received. 783 * 784 * In any case, it is not necessary for a passive scan. 785 */ 786 if (chan->flags & IEEE80211_CHAN_NO_IR || !scan_req->n_ssids) { 787 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 788 local->next_scan_state = SCAN_DECISION; 789 return; 790 } 791 792 /* active scan, send probes */ 793 *next_delay = IEEE80211_PROBE_DELAY; 794 local->next_scan_state = SCAN_SEND_PROBE; 795} 796 797static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 798 unsigned long *next_delay) 799{ 800 /* switch back to the operating channel */ 801 local->scan_chandef.chan = NULL; 802 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 803 804 /* disable PS */ 805 ieee80211_offchannel_return(local); 806 807 *next_delay = HZ / 5; 808 /* afterwards, resume scan & go to next channel */ 809 local->next_scan_state = SCAN_RESUME; 810} 811 812static void ieee80211_scan_state_resume(struct ieee80211_local *local, 813 unsigned long *next_delay) 814{ 815 ieee80211_offchannel_stop_vifs(local); 816 817 if (local->ops->flush) { 818 ieee80211_flush_queues(local, NULL, false); 819 *next_delay = 0; 820 } else 821 *next_delay = HZ / 10; 822 823 /* remember when we left the operating channel */ 824 local->leave_oper_channel_time = jiffies; 825 826 /* advance to the next channel to be scanned */ 827 local->next_scan_state = SCAN_SET_CHANNEL; 828} 829 830void ieee80211_scan_work(struct work_struct *work) 831{ 832 struct ieee80211_local *local = 833 container_of(work, struct ieee80211_local, scan_work.work); 834 struct ieee80211_sub_if_data *sdata; 835 struct cfg80211_scan_request *scan_req; 836 unsigned long next_delay = 0; 837 bool aborted; 838 839 mutex_lock(&local->mtx); 840 841 if (!ieee80211_can_run_worker(local)) { 842 aborted = true; 843 goto out_complete; 844 } 845 846 sdata = rcu_dereference_protected(local->scan_sdata, 847 lockdep_is_held(&local->mtx)); 848 scan_req = rcu_dereference_protected(local->scan_req, 849 lockdep_is_held(&local->mtx)); 850 851 /* When scanning on-channel, the first-callback means completed. */ 852 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 853 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 854 goto out_complete; 855 } 856 857 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 858 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 859 goto out_complete; 860 } 861 862 if (!sdata || !scan_req) 863 goto out; 864 865 if (!local->scanning) { 866 int rc; 867 868 RCU_INIT_POINTER(local->scan_req, NULL); 869 RCU_INIT_POINTER(local->scan_sdata, NULL); 870 871 rc = __ieee80211_start_scan(sdata, scan_req); 872 if (rc) { 873 /* need to complete scan in cfg80211 */ 874 rcu_assign_pointer(local->scan_req, scan_req); 875 aborted = true; 876 goto out_complete; 877 } else 878 goto out; 879 } 880 881 /* 882 * as long as no delay is required advance immediately 883 * without scheduling a new work 884 */ 885 do { 886 if (!ieee80211_sdata_running(sdata)) { 887 aborted = true; 888 goto out_complete; 889 } 890 891 switch (local->next_scan_state) { 892 case SCAN_DECISION: 893 /* if no more bands/channels left, complete scan */ 894 if (local->scan_channel_idx >= scan_req->n_channels) { 895 aborted = false; 896 goto out_complete; 897 } 898 ieee80211_scan_state_decision(local, &next_delay); 899 break; 900 case SCAN_SET_CHANNEL: 901 ieee80211_scan_state_set_channel(local, &next_delay); 902 break; 903 case SCAN_SEND_PROBE: 904 ieee80211_scan_state_send_probe(local, &next_delay); 905 break; 906 case SCAN_SUSPEND: 907 ieee80211_scan_state_suspend(local, &next_delay); 908 break; 909 case SCAN_RESUME: 910 ieee80211_scan_state_resume(local, &next_delay); 911 break; 912 case SCAN_ABORT: 913 aborted = true; 914 goto out_complete; 915 } 916 } while (next_delay == 0); 917 918 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 919 goto out; 920 921out_complete: 922 __ieee80211_scan_completed(&local->hw, aborted); 923out: 924 mutex_unlock(&local->mtx); 925} 926 927int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 928 struct cfg80211_scan_request *req) 929{ 930 int res; 931 932 mutex_lock(&sdata->local->mtx); 933 res = __ieee80211_start_scan(sdata, req); 934 mutex_unlock(&sdata->local->mtx); 935 936 return res; 937} 938 939int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 940 const u8 *ssid, u8 ssid_len, 941 struct ieee80211_channel **channels, 942 unsigned int n_channels, 943 enum nl80211_bss_scan_width scan_width) 944{ 945 struct ieee80211_local *local = sdata->local; 946 int ret = -EBUSY, i, n_ch = 0; 947 enum ieee80211_band band; 948 949 mutex_lock(&local->mtx); 950 951 /* busy scanning */ 952 if (local->scan_req) 953 goto unlock; 954 955 /* fill internal scan request */ 956 if (!channels) { 957 int max_n; 958 959 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 960 if (!local->hw.wiphy->bands[band]) 961 continue; 962 963 max_n = local->hw.wiphy->bands[band]->n_channels; 964 for (i = 0; i < max_n; i++) { 965 struct ieee80211_channel *tmp_ch = 966 &local->hw.wiphy->bands[band]->channels[i]; 967 968 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | 969 IEEE80211_CHAN_DISABLED)) 970 continue; 971 972 local->int_scan_req->channels[n_ch] = tmp_ch; 973 n_ch++; 974 } 975 } 976 977 if (WARN_ON_ONCE(n_ch == 0)) 978 goto unlock; 979 980 local->int_scan_req->n_channels = n_ch; 981 } else { 982 for (i = 0; i < n_channels; i++) { 983 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR | 984 IEEE80211_CHAN_DISABLED)) 985 continue; 986 987 local->int_scan_req->channels[n_ch] = channels[i]; 988 n_ch++; 989 } 990 991 if (WARN_ON_ONCE(n_ch == 0)) 992 goto unlock; 993 994 local->int_scan_req->n_channels = n_ch; 995 } 996 997 local->int_scan_req->ssids = &local->scan_ssid; 998 local->int_scan_req->n_ssids = 1; 999 local->int_scan_req->scan_width = scan_width; 1000 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 1001 local->int_scan_req->ssids[0].ssid_len = ssid_len; 1002 1003 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 1004 unlock: 1005 mutex_unlock(&local->mtx); 1006 return ret; 1007} 1008 1009/* 1010 * Only call this function when a scan can't be queued -- under RTNL. 1011 */ 1012void ieee80211_scan_cancel(struct ieee80211_local *local) 1013{ 1014 /* 1015 * We are canceling software scan, or deferred scan that was not 1016 * yet really started (see __ieee80211_start_scan ). 1017 * 1018 * Regarding hardware scan: 1019 * - we can not call __ieee80211_scan_completed() as when 1020 * SCAN_HW_SCANNING bit is set this function change 1021 * local->hw_scan_req to operate on 5G band, what race with 1022 * driver which can use local->hw_scan_req 1023 * 1024 * - we can not cancel scan_work since driver can schedule it 1025 * by ieee80211_scan_completed(..., true) to finish scan 1026 * 1027 * Hence we only call the cancel_hw_scan() callback, but the low-level 1028 * driver is still responsible for calling ieee80211_scan_completed() 1029 * after the scan was completed/aborted. 1030 */ 1031 1032 mutex_lock(&local->mtx); 1033 if (!local->scan_req) 1034 goto out; 1035 1036 /* 1037 * We have a scan running and the driver already reported completion, 1038 * but the worker hasn't run yet or is stuck on the mutex - mark it as 1039 * cancelled. 1040 */ 1041 if (test_bit(SCAN_HW_SCANNING, &local->scanning) && 1042 test_bit(SCAN_COMPLETED, &local->scanning)) { 1043 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1044 goto out; 1045 } 1046 1047 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 1048 /* 1049 * Make sure that __ieee80211_scan_completed doesn't trigger a 1050 * scan on another band. 1051 */ 1052 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1053 if (local->ops->cancel_hw_scan) 1054 drv_cancel_hw_scan(local, 1055 rcu_dereference_protected(local->scan_sdata, 1056 lockdep_is_held(&local->mtx))); 1057 goto out; 1058 } 1059 1060 /* 1061 * If the work is currently running, it must be blocked on 1062 * the mutex, but we'll set scan_sdata = NULL and it'll 1063 * simply exit once it acquires the mutex. 1064 */ 1065 cancel_delayed_work(&local->scan_work); 1066 /* and clean up */ 1067 __ieee80211_scan_completed(&local->hw, true); 1068out: 1069 mutex_unlock(&local->mtx); 1070} 1071 1072int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1073 struct cfg80211_sched_scan_request *req) 1074{ 1075 struct ieee80211_local *local = sdata->local; 1076 struct ieee80211_scan_ies sched_scan_ies = {}; 1077 struct cfg80211_chan_def chandef; 1078 int ret, i, iebufsz, num_bands = 0; 1079 u32 rate_masks[IEEE80211_NUM_BANDS] = {}; 1080 u8 bands_used = 0; 1081 u8 *ie; 1082 size_t len; 1083 1084 iebufsz = local->scan_ies_len + req->ie_len; 1085 1086 lockdep_assert_held(&local->mtx); 1087 1088 if (!local->ops->sched_scan_start) 1089 return -ENOTSUPP; 1090 1091 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 1092 if (local->hw.wiphy->bands[i]) { 1093 bands_used |= BIT(i); 1094 rate_masks[i] = (u32) -1; 1095 num_bands++; 1096 } 1097 } 1098 1099 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL); 1100 if (!ie) { 1101 ret = -ENOMEM; 1102 goto out; 1103 } 1104 1105 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 1106 1107 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz, 1108 &sched_scan_ies, req->ie, 1109 req->ie_len, bands_used, 1110 rate_masks, &chandef); 1111 1112 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 1113 if (ret == 0) { 1114 rcu_assign_pointer(local->sched_scan_sdata, sdata); 1115 rcu_assign_pointer(local->sched_scan_req, req); 1116 } 1117 1118 kfree(ie); 1119 1120out: 1121 if (ret) { 1122 /* Clean in case of failure after HW restart or upon resume. */ 1123 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1124 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1125 } 1126 1127 return ret; 1128} 1129 1130int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1131 struct cfg80211_sched_scan_request *req) 1132{ 1133 struct ieee80211_local *local = sdata->local; 1134 int ret; 1135 1136 mutex_lock(&local->mtx); 1137 1138 if (rcu_access_pointer(local->sched_scan_sdata)) { 1139 mutex_unlock(&local->mtx); 1140 return -EBUSY; 1141 } 1142 1143 ret = __ieee80211_request_sched_scan_start(sdata, req); 1144 1145 mutex_unlock(&local->mtx); 1146 return ret; 1147} 1148 1149int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 1150{ 1151 struct ieee80211_local *local = sdata->local; 1152 int ret = 0; 1153 1154 mutex_lock(&local->mtx); 1155 1156 if (!local->ops->sched_scan_stop) { 1157 ret = -ENOTSUPP; 1158 goto out; 1159 } 1160 1161 /* We don't want to restart sched scan anymore. */ 1162 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1163 1164 if (rcu_access_pointer(local->sched_scan_sdata)) { 1165 ret = drv_sched_scan_stop(local, sdata); 1166 if (!ret) 1167 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1168 } 1169out: 1170 mutex_unlock(&local->mtx); 1171 1172 return ret; 1173} 1174 1175void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 1176{ 1177 struct ieee80211_local *local = hw_to_local(hw); 1178 1179 trace_api_sched_scan_results(local); 1180 1181 cfg80211_sched_scan_results(hw->wiphy); 1182} 1183EXPORT_SYMBOL(ieee80211_sched_scan_results); 1184 1185void ieee80211_sched_scan_end(struct ieee80211_local *local) 1186{ 1187 mutex_lock(&local->mtx); 1188 1189 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1190 mutex_unlock(&local->mtx); 1191 return; 1192 } 1193 1194 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1195 1196 /* If sched scan was aborted by the driver. */ 1197 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1198 1199 mutex_unlock(&local->mtx); 1200 1201 cfg80211_sched_scan_stopped(local->hw.wiphy); 1202} 1203 1204void ieee80211_sched_scan_stopped_work(struct work_struct *work) 1205{ 1206 struct ieee80211_local *local = 1207 container_of(work, struct ieee80211_local, 1208 sched_scan_stopped_work); 1209 1210 ieee80211_sched_scan_end(local); 1211} 1212 1213void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1214{ 1215 struct ieee80211_local *local = hw_to_local(hw); 1216 1217 trace_api_sched_scan_stopped(local); 1218 1219 schedule_work(&local->sched_scan_stopped_work); 1220} 1221EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1222