1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Scanning implementation 4 * 5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 6 * Copyright 2004, Instant802 Networks, Inc. 7 * Copyright 2005, Devicescape Software, Inc. 8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 10 * Copyright 2013-2015 Intel Mobile Communications GmbH 11 * Copyright 2016-2017 Intel Deutschland GmbH 12 * Copyright (C) 2018-2021 Intel Corporation 13 */ 14 15 #include <linux/if_arp.h> 16 #include <linux/etherdevice.h> 17 #include <linux/rtnetlink.h> 18 #include <net/sch_generic.h> 19 #include <linux/slab.h> 20 #include <linux/export.h> 21 #include <linux/random.h> 22 #include <net/mac80211.h> 23 24 #include "ieee80211_i.h" 25 #include "driver-ops.h" 26 #include "mesh.h" 27 28 #define IEEE80211_PROBE_DELAY (HZ / 33) 29 #define IEEE80211_CHANNEL_TIME (HZ / 33) 30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9) 31 32 void ieee80211_rx_bss_put(struct ieee80211_local *local, 33 struct ieee80211_bss *bss) 34 { 35 if (!bss) 36 return; 37 cfg80211_put_bss(local->hw.wiphy, 38 container_of((void *)bss, struct cfg80211_bss, priv)); 39 } 40 41 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 42 { 43 u8 qos_info; 44 45 if (elems->wmm_info && elems->wmm_info_len == 7 46 && elems->wmm_info[5] == 1) 47 qos_info = elems->wmm_info[6]; 48 else if (elems->wmm_param && elems->wmm_param_len == 24 49 && elems->wmm_param[5] == 1) 50 qos_info = elems->wmm_param[6]; 51 else 52 /* no valid wmm information or parameter element found */ 53 return false; 54 55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 56 } 57 58 static void 59 ieee80211_update_bss_from_elems(struct ieee80211_local *local, 60 struct ieee80211_bss *bss, 61 struct ieee802_11_elems *elems, 62 struct ieee80211_rx_status *rx_status, 63 bool beacon) 64 { 65 int clen, srlen; 66 67 if (beacon) 68 bss->device_ts_beacon = rx_status->device_timestamp; 69 else 70 bss->device_ts_presp = rx_status->device_timestamp; 71 72 if (elems->parse_error) { 73 if (beacon) 74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 75 else 76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 77 } else { 78 if (beacon) 79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 80 else 81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 82 } 83 84 /* save the ERP value so that it is available at association time */ 85 if (elems->erp_info && (!elems->parse_error || 86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 87 bss->erp_value = elems->erp_info[0]; 88 bss->has_erp_value = true; 89 if (!elems->parse_error) 90 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 91 } 92 93 /* replace old supported rates if we get new values */ 94 if (!elems->parse_error || 95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 96 srlen = 0; 97 if (elems->supp_rates) { 98 clen = IEEE80211_MAX_SUPP_RATES; 99 if (clen > elems->supp_rates_len) 100 clen = elems->supp_rates_len; 101 memcpy(bss->supp_rates, elems->supp_rates, clen); 102 srlen += clen; 103 } 104 if (elems->ext_supp_rates) { 105 clen = IEEE80211_MAX_SUPP_RATES - srlen; 106 if (clen > elems->ext_supp_rates_len) 107 clen = elems->ext_supp_rates_len; 108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 109 clen); 110 srlen += clen; 111 } 112 if (srlen) { 113 bss->supp_rates_len = srlen; 114 if (!elems->parse_error) 115 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 116 } 117 } 118 119 if (!elems->parse_error || 120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 121 bss->wmm_used = elems->wmm_param || elems->wmm_info; 122 bss->uapsd_supported = is_uapsd_supported(elems); 123 if (!elems->parse_error) 124 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 125 } 126 127 if (beacon) { 128 struct ieee80211_supported_band *sband = 129 local->hw.wiphy->bands[rx_status->band]; 130 if (!(rx_status->encoding == RX_ENC_HT) && 131 !(rx_status->encoding == RX_ENC_VHT)) 132 bss->beacon_rate = 133 &sband->bitrates[rx_status->rate_idx]; 134 } 135 136 if (elems->vht_cap_elem) 137 bss->vht_cap_info = 138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info); 139 else 140 bss->vht_cap_info = 0; 141 } 142 143 struct ieee80211_bss * 144 ieee80211_bss_info_update(struct ieee80211_local *local, 145 struct ieee80211_rx_status *rx_status, 146 struct ieee80211_mgmt *mgmt, size_t len, 147 struct ieee80211_channel *channel) 148 { 149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) || 150 ieee80211_is_s1g_beacon(mgmt->frame_control); 151 struct cfg80211_bss *cbss, *non_tx_cbss; 152 struct ieee80211_bss *bss, *non_tx_bss; 153 struct cfg80211_inform_bss bss_meta = { 154 .boottime_ns = rx_status->boottime_ns, 155 }; 156 bool signal_valid; 157 struct ieee80211_sub_if_data *scan_sdata; 158 struct ieee802_11_elems *elems; 159 size_t baselen; 160 u8 *elements; 161 162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL) 163 bss_meta.signal = 0; /* invalid signal indication */ 164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM)) 165 bss_meta.signal = rx_status->signal * 100; 166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC)) 167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal; 168 169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20; 170 if (rx_status->bw == RATE_INFO_BW_5) 171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5; 172 else if (rx_status->bw == RATE_INFO_BW_10) 173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10; 174 175 bss_meta.chan = channel; 176 177 rcu_read_lock(); 178 scan_sdata = rcu_dereference(local->scan_sdata); 179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION && 180 scan_sdata->vif.cfg.assoc && 181 ieee80211_have_rx_timestamp(rx_status)) { 182 bss_meta.parent_tsf = 183 ieee80211_calculate_rx_timestamp(local, rx_status, 184 len + FCS_LEN, 24); 185 ether_addr_copy(bss_meta.parent_bssid, 186 scan_sdata->vif.bss_conf.bssid); 187 } 188 rcu_read_unlock(); 189 190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, 191 mgmt, len, GFP_ATOMIC); 192 if (!cbss) 193 return NULL; 194 195 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 196 elements = mgmt->u.probe_resp.variable; 197 baselen = offsetof(struct ieee80211_mgmt, 198 u.probe_resp.variable); 199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) { 200 struct ieee80211_ext *ext = (void *) mgmt; 201 202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable); 203 elements = ext->u.s1g_beacon.variable; 204 } else { 205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 206 elements = mgmt->u.beacon.variable; 207 } 208 209 if (baselen > len) 210 return NULL; 211 212 elems = ieee802_11_parse_elems(elements, len - baselen, false, cbss); 213 if (!elems) 214 return NULL; 215 216 /* In case the signal is invalid update the status */ 217 signal_valid = channel == cbss->channel; 218 if (!signal_valid) 219 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL; 220 221 bss = (void *)cbss->priv; 222 ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon); 223 kfree(elems); 224 225 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) { 226 non_tx_bss = (void *)non_tx_cbss->priv; 227 228 elems = ieee802_11_parse_elems(elements, len - baselen, false, 229 non_tx_cbss); 230 if (!elems) 231 continue; 232 233 ieee80211_update_bss_from_elems(local, non_tx_bss, elems, 234 rx_status, beacon); 235 kfree(elems); 236 } 237 238 return bss; 239 } 240 241 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata, 242 u32 scan_flags, const u8 *da) 243 { 244 if (!sdata) 245 return false; 246 /* accept broadcast for OCE */ 247 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP && 248 is_broadcast_ether_addr(da)) 249 return true; 250 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR) 251 return true; 252 return ether_addr_equal(da, sdata->vif.addr); 253 } 254 255 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 256 { 257 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 258 struct ieee80211_sub_if_data *sdata1, *sdata2; 259 struct ieee80211_mgmt *mgmt = (void *)skb->data; 260 struct ieee80211_bss *bss; 261 struct ieee80211_channel *channel; 262 size_t min_hdr_len = offsetof(struct ieee80211_mgmt, 263 u.probe_resp.variable); 264 265 if (!ieee80211_is_probe_resp(mgmt->frame_control) && 266 !ieee80211_is_beacon(mgmt->frame_control) && 267 !ieee80211_is_s1g_beacon(mgmt->frame_control)) 268 return; 269 270 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) { 271 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control)) 272 min_hdr_len = offsetof(struct ieee80211_ext, 273 u.s1g_short_beacon.variable); 274 else 275 min_hdr_len = offsetof(struct ieee80211_ext, 276 u.s1g_beacon); 277 } 278 279 if (skb->len < min_hdr_len) 280 return; 281 282 sdata1 = rcu_dereference(local->scan_sdata); 283 sdata2 = rcu_dereference(local->sched_scan_sdata); 284 285 if (likely(!sdata1 && !sdata2)) 286 return; 287 288 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) { 289 /* 290 * we were passive scanning because of radar/no-IR, but 291 * the beacon/proberesp rx gives us an opportunity to upgrade 292 * to active scan 293 */ 294 set_bit(SCAN_BEACON_DONE, &local->scanning); 295 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 296 } 297 298 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 299 struct cfg80211_scan_request *scan_req; 300 struct cfg80211_sched_scan_request *sched_scan_req; 301 u32 scan_req_flags = 0, sched_scan_req_flags = 0; 302 303 scan_req = rcu_dereference(local->scan_req); 304 sched_scan_req = rcu_dereference(local->sched_scan_req); 305 306 if (scan_req) 307 scan_req_flags = scan_req->flags; 308 309 if (sched_scan_req) 310 sched_scan_req_flags = sched_scan_req->flags; 311 312 /* ignore ProbeResp to foreign address or non-bcast (OCE) 313 * unless scanning with randomised address 314 */ 315 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags, 316 mgmt->da) && 317 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags, 318 mgmt->da)) 319 return; 320 } 321 322 channel = ieee80211_get_channel_khz(local->hw.wiphy, 323 ieee80211_rx_status_to_khz(rx_status)); 324 325 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 326 return; 327 328 bss = ieee80211_bss_info_update(local, rx_status, 329 mgmt, skb->len, 330 channel); 331 if (bss) 332 ieee80211_rx_bss_put(local, bss); 333 } 334 335 static void 336 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, 337 enum nl80211_bss_scan_width scan_width) 338 { 339 memset(chandef, 0, sizeof(*chandef)); 340 switch (scan_width) { 341 case NL80211_BSS_CHAN_WIDTH_5: 342 chandef->width = NL80211_CHAN_WIDTH_5; 343 break; 344 case NL80211_BSS_CHAN_WIDTH_10: 345 chandef->width = NL80211_CHAN_WIDTH_10; 346 break; 347 default: 348 chandef->width = NL80211_CHAN_WIDTH_20_NOHT; 349 break; 350 } 351 } 352 353 /* return false if no more work */ 354 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata) 355 { 356 struct ieee80211_local *local = sdata->local; 357 struct cfg80211_scan_request *req; 358 struct cfg80211_chan_def chandef; 359 u8 bands_used = 0; 360 int i, ielen, n_chans; 361 u32 flags = 0; 362 363 req = rcu_dereference_protected(local->scan_req, 364 lockdep_is_held(&local->mtx)); 365 366 if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) 367 return false; 368 369 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { 370 for (i = 0; i < req->n_channels; i++) { 371 local->hw_scan_req->req.channels[i] = req->channels[i]; 372 bands_used |= BIT(req->channels[i]->band); 373 } 374 375 n_chans = req->n_channels; 376 } else { 377 do { 378 if (local->hw_scan_band == NUM_NL80211_BANDS) 379 return false; 380 381 n_chans = 0; 382 383 for (i = 0; i < req->n_channels; i++) { 384 if (req->channels[i]->band != 385 local->hw_scan_band) 386 continue; 387 local->hw_scan_req->req.channels[n_chans] = 388 req->channels[i]; 389 n_chans++; 390 bands_used |= BIT(req->channels[i]->band); 391 } 392 393 local->hw_scan_band++; 394 } while (!n_chans); 395 } 396 397 local->hw_scan_req->req.n_channels = n_chans; 398 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 399 400 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT) 401 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT; 402 403 ielen = ieee80211_build_preq_ies(sdata, 404 (u8 *)local->hw_scan_req->req.ie, 405 local->hw_scan_ies_bufsize, 406 &local->hw_scan_req->ies, 407 req->ie, req->ie_len, 408 bands_used, req->rates, &chandef, 409 flags); 410 local->hw_scan_req->req.ie_len = ielen; 411 local->hw_scan_req->req.no_cck = req->no_cck; 412 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr); 413 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask, 414 req->mac_addr_mask); 415 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid); 416 417 return true; 418 } 419 420 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 421 { 422 struct ieee80211_local *local = hw_to_local(hw); 423 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 424 bool was_scanning = local->scanning; 425 struct cfg80211_scan_request *scan_req; 426 struct ieee80211_sub_if_data *scan_sdata; 427 struct ieee80211_sub_if_data *sdata; 428 429 lockdep_assert_held(&local->mtx); 430 431 /* 432 * It's ok to abort a not-yet-running scan (that 433 * we have one at all will be verified by checking 434 * local->scan_req next), but not to complete it 435 * successfully. 436 */ 437 if (WARN_ON(!local->scanning && !aborted)) 438 aborted = true; 439 440 if (WARN_ON(!local->scan_req)) 441 return; 442 443 scan_sdata = rcu_dereference_protected(local->scan_sdata, 444 lockdep_is_held(&local->mtx)); 445 446 if (hw_scan && !aborted && 447 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) && 448 ieee80211_prep_hw_scan(scan_sdata)) { 449 int rc; 450 451 rc = drv_hw_scan(local, 452 rcu_dereference_protected(local->scan_sdata, 453 lockdep_is_held(&local->mtx)), 454 local->hw_scan_req); 455 456 if (rc == 0) 457 return; 458 459 /* HW scan failed and is going to be reported as aborted, 460 * so clear old scan info. 461 */ 462 memset(&local->scan_info, 0, sizeof(local->scan_info)); 463 aborted = true; 464 } 465 466 kfree(local->hw_scan_req); 467 local->hw_scan_req = NULL; 468 469 scan_req = rcu_dereference_protected(local->scan_req, 470 lockdep_is_held(&local->mtx)); 471 472 RCU_INIT_POINTER(local->scan_req, NULL); 473 RCU_INIT_POINTER(local->scan_sdata, NULL); 474 475 local->scanning = 0; 476 local->scan_chandef.chan = NULL; 477 478 synchronize_rcu(); 479 480 if (scan_req != local->int_scan_req) { 481 local->scan_info.aborted = aborted; 482 cfg80211_scan_done(scan_req, &local->scan_info); 483 } 484 485 /* Set power back to normal operating levels. */ 486 ieee80211_hw_config(local, 0); 487 488 if (!hw_scan && was_scanning) { 489 ieee80211_configure_filter(local); 490 drv_sw_scan_complete(local, scan_sdata); 491 ieee80211_offchannel_return(local); 492 } 493 494 ieee80211_recalc_idle(local); 495 496 ieee80211_mlme_notify_scan_completed(local); 497 ieee80211_ibss_notify_scan_completed(local); 498 499 /* Requeue all the work that might have been ignored while 500 * the scan was in progress; if there was none this will 501 * just be a no-op for the particular interface. 502 */ 503 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 504 if (ieee80211_sdata_running(sdata)) 505 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 506 } 507 508 if (was_scanning) 509 ieee80211_start_next_roc(local); 510 } 511 512 void ieee80211_scan_completed(struct ieee80211_hw *hw, 513 struct cfg80211_scan_info *info) 514 { 515 struct ieee80211_local *local = hw_to_local(hw); 516 517 trace_api_scan_completed(local, info->aborted); 518 519 set_bit(SCAN_COMPLETED, &local->scanning); 520 if (info->aborted) 521 set_bit(SCAN_ABORTED, &local->scanning); 522 523 memcpy(&local->scan_info, info, sizeof(*info)); 524 525 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 526 } 527 EXPORT_SYMBOL(ieee80211_scan_completed); 528 529 static int ieee80211_start_sw_scan(struct ieee80211_local *local, 530 struct ieee80211_sub_if_data *sdata) 531 { 532 /* Software scan is not supported in multi-channel cases */ 533 if (local->use_chanctx) 534 return -EOPNOTSUPP; 535 536 /* 537 * Hardware/driver doesn't support hw_scan, so use software 538 * scanning instead. First send a nullfunc frame with power save 539 * bit on so that AP will buffer the frames for us while we are not 540 * listening, then send probe requests to each channel and wait for 541 * the responses. After all channels are scanned, tune back to the 542 * original channel and send a nullfunc frame with power save bit 543 * off to trigger the AP to send us all the buffered frames. 544 * 545 * Note that while local->sw_scanning is true everything else but 546 * nullfunc frames and probe requests will be dropped in 547 * ieee80211_tx_h_check_assoc(). 548 */ 549 drv_sw_scan_start(local, sdata, local->scan_addr); 550 551 local->leave_oper_channel_time = jiffies; 552 local->next_scan_state = SCAN_DECISION; 553 local->scan_channel_idx = 0; 554 555 ieee80211_offchannel_stop_vifs(local); 556 557 /* ensure nullfunc is transmitted before leaving operating channel */ 558 ieee80211_flush_queues(local, NULL, false); 559 560 ieee80211_configure_filter(local); 561 562 /* We need to set power level at maximum rate for scanning. */ 563 ieee80211_hw_config(local, 0); 564 565 ieee80211_queue_delayed_work(&local->hw, 566 &local->scan_work, 0); 567 568 return 0; 569 } 570 571 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata) 572 { 573 struct ieee80211_local *local = sdata->local; 574 struct ieee80211_sub_if_data *sdata_iter; 575 576 if (!ieee80211_is_radar_required(local)) 577 return true; 578 579 if (!regulatory_pre_cac_allowed(local->hw.wiphy)) 580 return false; 581 582 mutex_lock(&local->iflist_mtx); 583 list_for_each_entry(sdata_iter, &local->interfaces, list) { 584 if (sdata_iter->wdev.cac_started) { 585 mutex_unlock(&local->iflist_mtx); 586 return false; 587 } 588 } 589 mutex_unlock(&local->iflist_mtx); 590 591 return true; 592 } 593 594 static bool ieee80211_can_scan(struct ieee80211_local *local, 595 struct ieee80211_sub_if_data *sdata) 596 { 597 if (!__ieee80211_can_leave_ch(sdata)) 598 return false; 599 600 if (!list_empty(&local->roc_list)) 601 return false; 602 603 if (sdata->vif.type == NL80211_IFTYPE_STATION && 604 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) 605 return false; 606 607 return true; 608 } 609 610 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 611 { 612 lockdep_assert_held(&local->mtx); 613 614 if (!local->scan_req || local->scanning) 615 return; 616 617 if (!ieee80211_can_scan(local, 618 rcu_dereference_protected( 619 local->scan_sdata, 620 lockdep_is_held(&local->mtx)))) 621 return; 622 623 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 624 round_jiffies_relative(0)); 625 } 626 627 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata, 628 const u8 *src, const u8 *dst, 629 const u8 *ssid, size_t ssid_len, 630 const u8 *ie, size_t ie_len, 631 u32 ratemask, u32 flags, u32 tx_flags, 632 struct ieee80211_channel *channel) 633 { 634 struct sk_buff *skb; 635 636 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel, 637 ssid, ssid_len, 638 ie, ie_len, flags); 639 640 if (skb) { 641 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) { 642 struct ieee80211_hdr *hdr = (void *)skb->data; 643 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 644 u16 sn = get_random_u16(); 645 646 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO; 647 hdr->seq_ctrl = 648 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn)); 649 } 650 IEEE80211_SKB_CB(skb)->flags |= tx_flags; 651 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band); 652 } 653 } 654 655 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 656 unsigned long *next_delay) 657 { 658 int i; 659 struct ieee80211_sub_if_data *sdata; 660 struct cfg80211_scan_request *scan_req; 661 enum nl80211_band band = local->hw.conf.chandef.chan->band; 662 u32 flags = 0, tx_flags; 663 664 scan_req = rcu_dereference_protected(local->scan_req, 665 lockdep_is_held(&local->mtx)); 666 667 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 668 if (scan_req->no_cck) 669 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 670 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT) 671 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT; 672 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN) 673 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN; 674 675 sdata = rcu_dereference_protected(local->scan_sdata, 676 lockdep_is_held(&local->mtx)); 677 678 for (i = 0; i < scan_req->n_ssids; i++) 679 ieee80211_send_scan_probe_req( 680 sdata, local->scan_addr, scan_req->bssid, 681 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len, 682 scan_req->ie, scan_req->ie_len, 683 scan_req->rates[band], flags, 684 tx_flags, local->hw.conf.chandef.chan); 685 686 /* 687 * After sending probe requests, wait for probe responses 688 * on the channel. 689 */ 690 *next_delay = IEEE80211_CHANNEL_TIME; 691 local->next_scan_state = SCAN_DECISION; 692 } 693 694 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 695 struct cfg80211_scan_request *req) 696 { 697 struct ieee80211_local *local = sdata->local; 698 bool hw_scan = local->ops->hw_scan; 699 int rc; 700 701 lockdep_assert_held(&local->mtx); 702 703 if (local->scan_req) 704 return -EBUSY; 705 706 if (!__ieee80211_can_leave_ch(sdata)) 707 return -EBUSY; 708 709 if (!ieee80211_can_scan(local, sdata)) { 710 /* wait for the work to finish/time out */ 711 rcu_assign_pointer(local->scan_req, req); 712 rcu_assign_pointer(local->scan_sdata, sdata); 713 return 0; 714 } 715 716 again: 717 if (hw_scan) { 718 u8 *ies; 719 720 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; 721 722 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { 723 int i, n_bands = 0; 724 u8 bands_counted = 0; 725 726 for (i = 0; i < req->n_channels; i++) { 727 if (bands_counted & BIT(req->channels[i]->band)) 728 continue; 729 bands_counted |= BIT(req->channels[i]->band); 730 n_bands++; 731 } 732 733 local->hw_scan_ies_bufsize *= n_bands; 734 } 735 736 local->hw_scan_req = kmalloc( 737 sizeof(*local->hw_scan_req) + 738 req->n_channels * sizeof(req->channels[0]) + 739 local->hw_scan_ies_bufsize, GFP_KERNEL); 740 if (!local->hw_scan_req) 741 return -ENOMEM; 742 743 local->hw_scan_req->req.ssids = req->ssids; 744 local->hw_scan_req->req.n_ssids = req->n_ssids; 745 ies = (u8 *)local->hw_scan_req + 746 sizeof(*local->hw_scan_req) + 747 req->n_channels * sizeof(req->channels[0]); 748 local->hw_scan_req->req.ie = ies; 749 local->hw_scan_req->req.flags = req->flags; 750 eth_broadcast_addr(local->hw_scan_req->req.bssid); 751 local->hw_scan_req->req.duration = req->duration; 752 local->hw_scan_req->req.duration_mandatory = 753 req->duration_mandatory; 754 755 local->hw_scan_band = 0; 756 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params; 757 local->hw_scan_req->req.scan_6ghz_params = 758 req->scan_6ghz_params; 759 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz; 760 761 /* 762 * After allocating local->hw_scan_req, we must 763 * go through until ieee80211_prep_hw_scan(), so 764 * anything that might be changed here and leave 765 * this function early must not go after this 766 * allocation. 767 */ 768 } 769 770 rcu_assign_pointer(local->scan_req, req); 771 rcu_assign_pointer(local->scan_sdata, sdata); 772 773 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) 774 get_random_mask_addr(local->scan_addr, 775 req->mac_addr, 776 req->mac_addr_mask); 777 else 778 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN); 779 780 if (hw_scan) { 781 __set_bit(SCAN_HW_SCANNING, &local->scanning); 782 } else if ((req->n_channels == 1) && 783 (req->channels[0] == local->_oper_chandef.chan)) { 784 /* 785 * If we are scanning only on the operating channel 786 * then we do not need to stop normal activities 787 */ 788 unsigned long next_delay; 789 790 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 791 792 ieee80211_recalc_idle(local); 793 794 /* Notify driver scan is starting, keep order of operations 795 * same as normal software scan, in case that matters. */ 796 drv_sw_scan_start(local, sdata, local->scan_addr); 797 798 ieee80211_configure_filter(local); /* accept probe-responses */ 799 800 /* We need to ensure power level is at max for scanning. */ 801 ieee80211_hw_config(local, 0); 802 803 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR | 804 IEEE80211_CHAN_RADAR)) || 805 !req->n_ssids) { 806 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 807 if (req->n_ssids) 808 set_bit(SCAN_BEACON_WAIT, &local->scanning); 809 } else { 810 ieee80211_scan_state_send_probe(local, &next_delay); 811 next_delay = IEEE80211_CHANNEL_TIME; 812 } 813 814 /* Now, just wait a bit and we are all done! */ 815 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 816 next_delay); 817 return 0; 818 } else { 819 /* Do normal software scan */ 820 __set_bit(SCAN_SW_SCANNING, &local->scanning); 821 } 822 823 ieee80211_recalc_idle(local); 824 825 if (hw_scan) { 826 WARN_ON(!ieee80211_prep_hw_scan(sdata)); 827 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 828 } else { 829 rc = ieee80211_start_sw_scan(local, sdata); 830 } 831 832 if (rc) { 833 kfree(local->hw_scan_req); 834 local->hw_scan_req = NULL; 835 local->scanning = 0; 836 837 ieee80211_recalc_idle(local); 838 839 local->scan_req = NULL; 840 RCU_INIT_POINTER(local->scan_sdata, NULL); 841 } 842 843 if (hw_scan && rc == 1) { 844 /* 845 * we can't fall back to software for P2P-GO 846 * as it must update NoA etc. 847 */ 848 if (ieee80211_vif_type_p2p(&sdata->vif) == 849 NL80211_IFTYPE_P2P_GO) 850 return -EOPNOTSUPP; 851 hw_scan = false; 852 goto again; 853 } 854 855 return rc; 856 } 857 858 static unsigned long 859 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 860 { 861 /* 862 * TODO: channel switching also consumes quite some time, 863 * add that delay as well to get a better estimation 864 */ 865 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) 866 return IEEE80211_PASSIVE_CHANNEL_TIME; 867 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 868 } 869 870 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 871 unsigned long *next_delay) 872 { 873 bool associated = false; 874 bool tx_empty = true; 875 bool bad_latency; 876 struct ieee80211_sub_if_data *sdata; 877 struct ieee80211_channel *next_chan; 878 enum mac80211_scan_state next_scan_state; 879 struct cfg80211_scan_request *scan_req; 880 881 /* 882 * check if at least one STA interface is associated, 883 * check if at least one STA interface has pending tx frames 884 * and grab the lowest used beacon interval 885 */ 886 mutex_lock(&local->iflist_mtx); 887 list_for_each_entry(sdata, &local->interfaces, list) { 888 if (!ieee80211_sdata_running(sdata)) 889 continue; 890 891 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 892 if (sdata->u.mgd.associated) { 893 associated = true; 894 895 if (!qdisc_all_tx_empty(sdata->dev)) { 896 tx_empty = false; 897 break; 898 } 899 } 900 } 901 } 902 mutex_unlock(&local->iflist_mtx); 903 904 scan_req = rcu_dereference_protected(local->scan_req, 905 lockdep_is_held(&local->mtx)); 906 907 next_chan = scan_req->channels[local->scan_channel_idx]; 908 909 /* 910 * we're currently scanning a different channel, let's 911 * see if we can scan another channel without interfering 912 * with the current traffic situation. 913 * 914 * Keep good latency, do not stay off-channel more than 125 ms. 915 */ 916 917 bad_latency = time_after(jiffies + 918 ieee80211_scan_get_channel_time(next_chan), 919 local->leave_oper_channel_time + HZ / 8); 920 921 if (associated && !tx_empty) { 922 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 923 next_scan_state = SCAN_ABORT; 924 else 925 next_scan_state = SCAN_SUSPEND; 926 } else if (associated && bad_latency) { 927 next_scan_state = SCAN_SUSPEND; 928 } else { 929 next_scan_state = SCAN_SET_CHANNEL; 930 } 931 932 local->next_scan_state = next_scan_state; 933 934 *next_delay = 0; 935 } 936 937 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 938 unsigned long *next_delay) 939 { 940 int skip; 941 struct ieee80211_channel *chan; 942 enum nl80211_bss_scan_width oper_scan_width; 943 struct cfg80211_scan_request *scan_req; 944 945 scan_req = rcu_dereference_protected(local->scan_req, 946 lockdep_is_held(&local->mtx)); 947 948 skip = 0; 949 chan = scan_req->channels[local->scan_channel_idx]; 950 951 local->scan_chandef.chan = chan; 952 local->scan_chandef.center_freq1 = chan->center_freq; 953 local->scan_chandef.freq1_offset = chan->freq_offset; 954 local->scan_chandef.center_freq2 = 0; 955 956 /* For scanning on the S1G band, ignore scan_width (which is constant 957 * across all channels) for now since channel width is specific to each 958 * channel. Detect the required channel width here and likely revisit 959 * later. Maybe scan_width could be used to build the channel scan list? 960 */ 961 if (chan->band == NL80211_BAND_S1GHZ) { 962 local->scan_chandef.width = ieee80211_s1g_channel_width(chan); 963 goto set_channel; 964 } 965 966 switch (scan_req->scan_width) { 967 case NL80211_BSS_CHAN_WIDTH_5: 968 local->scan_chandef.width = NL80211_CHAN_WIDTH_5; 969 break; 970 case NL80211_BSS_CHAN_WIDTH_10: 971 local->scan_chandef.width = NL80211_CHAN_WIDTH_10; 972 break; 973 default: 974 case NL80211_BSS_CHAN_WIDTH_20: 975 /* If scanning on oper channel, use whatever channel-type 976 * is currently in use. 977 */ 978 oper_scan_width = cfg80211_chandef_to_scan_width( 979 &local->_oper_chandef); 980 if (chan == local->_oper_chandef.chan && 981 oper_scan_width == scan_req->scan_width) 982 local->scan_chandef = local->_oper_chandef; 983 else 984 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; 985 break; 986 case NL80211_BSS_CHAN_WIDTH_1: 987 case NL80211_BSS_CHAN_WIDTH_2: 988 /* shouldn't get here, S1G handled above */ 989 WARN_ON(1); 990 break; 991 } 992 993 set_channel: 994 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 995 skip = 1; 996 997 /* advance state machine to next channel/band */ 998 local->scan_channel_idx++; 999 1000 if (skip) { 1001 /* if we skip this channel return to the decision state */ 1002 local->next_scan_state = SCAN_DECISION; 1003 return; 1004 } 1005 1006 /* 1007 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 1008 * (which unfortunately doesn't say _why_ step a) is done, 1009 * but it waits for the probe delay or until a frame is 1010 * received - and the received frame would update the NAV). 1011 * For now, we do not support waiting until a frame is 1012 * received. 1013 * 1014 * In any case, it is not necessary for a passive scan. 1015 */ 1016 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) || 1017 !scan_req->n_ssids) { 1018 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 1019 local->next_scan_state = SCAN_DECISION; 1020 if (scan_req->n_ssids) 1021 set_bit(SCAN_BEACON_WAIT, &local->scanning); 1022 return; 1023 } 1024 1025 /* active scan, send probes */ 1026 *next_delay = IEEE80211_PROBE_DELAY; 1027 local->next_scan_state = SCAN_SEND_PROBE; 1028 } 1029 1030 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 1031 unsigned long *next_delay) 1032 { 1033 /* switch back to the operating channel */ 1034 local->scan_chandef.chan = NULL; 1035 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 1036 1037 /* disable PS */ 1038 ieee80211_offchannel_return(local); 1039 1040 *next_delay = HZ / 5; 1041 /* afterwards, resume scan & go to next channel */ 1042 local->next_scan_state = SCAN_RESUME; 1043 } 1044 1045 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 1046 unsigned long *next_delay) 1047 { 1048 ieee80211_offchannel_stop_vifs(local); 1049 1050 if (local->ops->flush) { 1051 ieee80211_flush_queues(local, NULL, false); 1052 *next_delay = 0; 1053 } else 1054 *next_delay = HZ / 10; 1055 1056 /* remember when we left the operating channel */ 1057 local->leave_oper_channel_time = jiffies; 1058 1059 /* advance to the next channel to be scanned */ 1060 local->next_scan_state = SCAN_SET_CHANNEL; 1061 } 1062 1063 void ieee80211_scan_work(struct work_struct *work) 1064 { 1065 struct ieee80211_local *local = 1066 container_of(work, struct ieee80211_local, scan_work.work); 1067 struct ieee80211_sub_if_data *sdata; 1068 struct cfg80211_scan_request *scan_req; 1069 unsigned long next_delay = 0; 1070 bool aborted; 1071 1072 mutex_lock(&local->mtx); 1073 1074 if (!ieee80211_can_run_worker(local)) { 1075 aborted = true; 1076 goto out_complete; 1077 } 1078 1079 sdata = rcu_dereference_protected(local->scan_sdata, 1080 lockdep_is_held(&local->mtx)); 1081 scan_req = rcu_dereference_protected(local->scan_req, 1082 lockdep_is_held(&local->mtx)); 1083 1084 /* When scanning on-channel, the first-callback means completed. */ 1085 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 1086 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 1087 goto out_complete; 1088 } 1089 1090 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 1091 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 1092 goto out_complete; 1093 } 1094 1095 if (!sdata || !scan_req) 1096 goto out; 1097 1098 if (!local->scanning) { 1099 int rc; 1100 1101 RCU_INIT_POINTER(local->scan_req, NULL); 1102 RCU_INIT_POINTER(local->scan_sdata, NULL); 1103 1104 rc = __ieee80211_start_scan(sdata, scan_req); 1105 if (rc) { 1106 /* need to complete scan in cfg80211 */ 1107 rcu_assign_pointer(local->scan_req, scan_req); 1108 aborted = true; 1109 goto out_complete; 1110 } else 1111 goto out; 1112 } 1113 1114 clear_bit(SCAN_BEACON_WAIT, &local->scanning); 1115 1116 /* 1117 * as long as no delay is required advance immediately 1118 * without scheduling a new work 1119 */ 1120 do { 1121 if (!ieee80211_sdata_running(sdata)) { 1122 aborted = true; 1123 goto out_complete; 1124 } 1125 1126 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) && 1127 local->next_scan_state == SCAN_DECISION) 1128 local->next_scan_state = SCAN_SEND_PROBE; 1129 1130 switch (local->next_scan_state) { 1131 case SCAN_DECISION: 1132 /* if no more bands/channels left, complete scan */ 1133 if (local->scan_channel_idx >= scan_req->n_channels) { 1134 aborted = false; 1135 goto out_complete; 1136 } 1137 ieee80211_scan_state_decision(local, &next_delay); 1138 break; 1139 case SCAN_SET_CHANNEL: 1140 ieee80211_scan_state_set_channel(local, &next_delay); 1141 break; 1142 case SCAN_SEND_PROBE: 1143 ieee80211_scan_state_send_probe(local, &next_delay); 1144 break; 1145 case SCAN_SUSPEND: 1146 ieee80211_scan_state_suspend(local, &next_delay); 1147 break; 1148 case SCAN_RESUME: 1149 ieee80211_scan_state_resume(local, &next_delay); 1150 break; 1151 case SCAN_ABORT: 1152 aborted = true; 1153 goto out_complete; 1154 } 1155 } while (next_delay == 0); 1156 1157 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 1158 goto out; 1159 1160 out_complete: 1161 __ieee80211_scan_completed(&local->hw, aborted); 1162 out: 1163 mutex_unlock(&local->mtx); 1164 } 1165 1166 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 1167 struct cfg80211_scan_request *req) 1168 { 1169 int res; 1170 1171 mutex_lock(&sdata->local->mtx); 1172 res = __ieee80211_start_scan(sdata, req); 1173 mutex_unlock(&sdata->local->mtx); 1174 1175 return res; 1176 } 1177 1178 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 1179 const u8 *ssid, u8 ssid_len, 1180 struct ieee80211_channel **channels, 1181 unsigned int n_channels, 1182 enum nl80211_bss_scan_width scan_width) 1183 { 1184 struct ieee80211_local *local = sdata->local; 1185 int ret = -EBUSY, i, n_ch = 0; 1186 enum nl80211_band band; 1187 1188 mutex_lock(&local->mtx); 1189 1190 /* busy scanning */ 1191 if (local->scan_req) 1192 goto unlock; 1193 1194 /* fill internal scan request */ 1195 if (!channels) { 1196 int max_n; 1197 1198 for (band = 0; band < NUM_NL80211_BANDS; band++) { 1199 if (!local->hw.wiphy->bands[band] || 1200 band == NL80211_BAND_6GHZ) 1201 continue; 1202 1203 max_n = local->hw.wiphy->bands[band]->n_channels; 1204 for (i = 0; i < max_n; i++) { 1205 struct ieee80211_channel *tmp_ch = 1206 &local->hw.wiphy->bands[band]->channels[i]; 1207 1208 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | 1209 IEEE80211_CHAN_DISABLED)) 1210 continue; 1211 1212 local->int_scan_req->channels[n_ch] = tmp_ch; 1213 n_ch++; 1214 } 1215 } 1216 1217 if (WARN_ON_ONCE(n_ch == 0)) 1218 goto unlock; 1219 1220 local->int_scan_req->n_channels = n_ch; 1221 } else { 1222 for (i = 0; i < n_channels; i++) { 1223 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR | 1224 IEEE80211_CHAN_DISABLED)) 1225 continue; 1226 1227 local->int_scan_req->channels[n_ch] = channels[i]; 1228 n_ch++; 1229 } 1230 1231 if (WARN_ON_ONCE(n_ch == 0)) 1232 goto unlock; 1233 1234 local->int_scan_req->n_channels = n_ch; 1235 } 1236 1237 local->int_scan_req->ssids = &local->scan_ssid; 1238 local->int_scan_req->n_ssids = 1; 1239 local->int_scan_req->scan_width = scan_width; 1240 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 1241 local->int_scan_req->ssids[0].ssid_len = ssid_len; 1242 1243 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 1244 unlock: 1245 mutex_unlock(&local->mtx); 1246 return ret; 1247 } 1248 1249 /* 1250 * Only call this function when a scan can't be queued -- under RTNL. 1251 */ 1252 void ieee80211_scan_cancel(struct ieee80211_local *local) 1253 { 1254 /* 1255 * We are canceling software scan, or deferred scan that was not 1256 * yet really started (see __ieee80211_start_scan ). 1257 * 1258 * Regarding hardware scan: 1259 * - we can not call __ieee80211_scan_completed() as when 1260 * SCAN_HW_SCANNING bit is set this function change 1261 * local->hw_scan_req to operate on 5G band, what race with 1262 * driver which can use local->hw_scan_req 1263 * 1264 * - we can not cancel scan_work since driver can schedule it 1265 * by ieee80211_scan_completed(..., true) to finish scan 1266 * 1267 * Hence we only call the cancel_hw_scan() callback, but the low-level 1268 * driver is still responsible for calling ieee80211_scan_completed() 1269 * after the scan was completed/aborted. 1270 */ 1271 1272 mutex_lock(&local->mtx); 1273 if (!local->scan_req) 1274 goto out; 1275 1276 /* 1277 * We have a scan running and the driver already reported completion, 1278 * but the worker hasn't run yet or is stuck on the mutex - mark it as 1279 * cancelled. 1280 */ 1281 if (test_bit(SCAN_HW_SCANNING, &local->scanning) && 1282 test_bit(SCAN_COMPLETED, &local->scanning)) { 1283 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1284 goto out; 1285 } 1286 1287 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 1288 /* 1289 * Make sure that __ieee80211_scan_completed doesn't trigger a 1290 * scan on another band. 1291 */ 1292 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1293 if (local->ops->cancel_hw_scan) 1294 drv_cancel_hw_scan(local, 1295 rcu_dereference_protected(local->scan_sdata, 1296 lockdep_is_held(&local->mtx))); 1297 goto out; 1298 } 1299 1300 /* 1301 * If the work is currently running, it must be blocked on 1302 * the mutex, but we'll set scan_sdata = NULL and it'll 1303 * simply exit once it acquires the mutex. 1304 */ 1305 cancel_delayed_work(&local->scan_work); 1306 /* and clean up */ 1307 memset(&local->scan_info, 0, sizeof(local->scan_info)); 1308 __ieee80211_scan_completed(&local->hw, true); 1309 out: 1310 mutex_unlock(&local->mtx); 1311 } 1312 1313 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1314 struct cfg80211_sched_scan_request *req) 1315 { 1316 struct ieee80211_local *local = sdata->local; 1317 struct ieee80211_scan_ies sched_scan_ies = {}; 1318 struct cfg80211_chan_def chandef; 1319 int ret, i, iebufsz, num_bands = 0; 1320 u32 rate_masks[NUM_NL80211_BANDS] = {}; 1321 u8 bands_used = 0; 1322 u8 *ie; 1323 u32 flags = 0; 1324 1325 iebufsz = local->scan_ies_len + req->ie_len; 1326 1327 lockdep_assert_held(&local->mtx); 1328 1329 if (!local->ops->sched_scan_start) 1330 return -ENOTSUPP; 1331 1332 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1333 if (local->hw.wiphy->bands[i]) { 1334 bands_used |= BIT(i); 1335 rate_masks[i] = (u32) -1; 1336 num_bands++; 1337 } 1338 } 1339 1340 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT) 1341 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT; 1342 1343 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL); 1344 if (!ie) { 1345 ret = -ENOMEM; 1346 goto out; 1347 } 1348 1349 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 1350 1351 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz, 1352 &sched_scan_ies, req->ie, 1353 req->ie_len, bands_used, rate_masks, &chandef, 1354 flags); 1355 1356 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 1357 if (ret == 0) { 1358 rcu_assign_pointer(local->sched_scan_sdata, sdata); 1359 rcu_assign_pointer(local->sched_scan_req, req); 1360 } 1361 1362 kfree(ie); 1363 1364 out: 1365 if (ret) { 1366 /* Clean in case of failure after HW restart or upon resume. */ 1367 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1368 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1369 } 1370 1371 return ret; 1372 } 1373 1374 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1375 struct cfg80211_sched_scan_request *req) 1376 { 1377 struct ieee80211_local *local = sdata->local; 1378 int ret; 1379 1380 mutex_lock(&local->mtx); 1381 1382 if (rcu_access_pointer(local->sched_scan_sdata)) { 1383 mutex_unlock(&local->mtx); 1384 return -EBUSY; 1385 } 1386 1387 ret = __ieee80211_request_sched_scan_start(sdata, req); 1388 1389 mutex_unlock(&local->mtx); 1390 return ret; 1391 } 1392 1393 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local) 1394 { 1395 struct ieee80211_sub_if_data *sched_scan_sdata; 1396 int ret = -ENOENT; 1397 1398 mutex_lock(&local->mtx); 1399 1400 if (!local->ops->sched_scan_stop) { 1401 ret = -ENOTSUPP; 1402 goto out; 1403 } 1404 1405 /* We don't want to restart sched scan anymore. */ 1406 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1407 1408 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata, 1409 lockdep_is_held(&local->mtx)); 1410 if (sched_scan_sdata) { 1411 ret = drv_sched_scan_stop(local, sched_scan_sdata); 1412 if (!ret) 1413 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1414 } 1415 out: 1416 mutex_unlock(&local->mtx); 1417 1418 return ret; 1419 } 1420 1421 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 1422 { 1423 struct ieee80211_local *local = hw_to_local(hw); 1424 1425 trace_api_sched_scan_results(local); 1426 1427 cfg80211_sched_scan_results(hw->wiphy, 0); 1428 } 1429 EXPORT_SYMBOL(ieee80211_sched_scan_results); 1430 1431 void ieee80211_sched_scan_end(struct ieee80211_local *local) 1432 { 1433 mutex_lock(&local->mtx); 1434 1435 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1436 mutex_unlock(&local->mtx); 1437 return; 1438 } 1439 1440 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1441 1442 /* If sched scan was aborted by the driver. */ 1443 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1444 1445 mutex_unlock(&local->mtx); 1446 1447 cfg80211_sched_scan_stopped(local->hw.wiphy, 0); 1448 } 1449 1450 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 1451 { 1452 struct ieee80211_local *local = 1453 container_of(work, struct ieee80211_local, 1454 sched_scan_stopped_work); 1455 1456 ieee80211_sched_scan_end(local); 1457 } 1458 1459 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1460 { 1461 struct ieee80211_local *local = hw_to_local(hw); 1462 1463 trace_api_sched_scan_stopped(local); 1464 1465 /* 1466 * this shouldn't really happen, so for simplicity 1467 * simply ignore it, and let mac80211 reconfigure 1468 * the sched scan later on. 1469 */ 1470 if (local->in_reconfig) 1471 return; 1472 1473 schedule_work(&local->sched_scan_stopped_work); 1474 } 1475 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1476