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 2013-2015 Intel Mobile Communications GmbH 10 * Copyright 2016-2017 Intel Deutschland GmbH 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License version 2 as 14 * published by the Free Software Foundation. 15 */ 16 17 #include <linux/if_arp.h> 18 #include <linux/etherdevice.h> 19 #include <linux/rtnetlink.h> 20 #include <net/sch_generic.h> 21 #include <linux/slab.h> 22 #include <linux/export.h> 23 #include <net/mac80211.h> 24 25 #include "ieee80211_i.h" 26 #include "driver-ops.h" 27 #include "mesh.h" 28 29 #define IEEE80211_PROBE_DELAY (HZ / 33) 30 #define IEEE80211_CHANNEL_TIME (HZ / 33) 31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9) 32 33 void ieee80211_rx_bss_put(struct ieee80211_local *local, 34 struct ieee80211_bss *bss) 35 { 36 if (!bss) 37 return; 38 cfg80211_put_bss(local->hw.wiphy, 39 container_of((void *)bss, struct cfg80211_bss, priv)); 40 } 41 42 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 43 { 44 u8 qos_info; 45 46 if (elems->wmm_info && elems->wmm_info_len == 7 47 && elems->wmm_info[5] == 1) 48 qos_info = elems->wmm_info[6]; 49 else if (elems->wmm_param && elems->wmm_param_len == 24 50 && elems->wmm_param[5] == 1) 51 qos_info = elems->wmm_param[6]; 52 else 53 /* no valid wmm information or parameter element found */ 54 return false; 55 56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 57 } 58 59 struct ieee80211_bss * 60 ieee80211_bss_info_update(struct ieee80211_local *local, 61 struct ieee80211_rx_status *rx_status, 62 struct ieee80211_mgmt *mgmt, size_t len, 63 struct ieee802_11_elems *elems, 64 struct ieee80211_channel *channel) 65 { 66 bool beacon = ieee80211_is_beacon(mgmt->frame_control); 67 struct cfg80211_bss *cbss; 68 struct ieee80211_bss *bss; 69 int clen, srlen; 70 struct cfg80211_inform_bss bss_meta = { 71 .boottime_ns = rx_status->boottime_ns, 72 }; 73 bool signal_valid; 74 struct ieee80211_sub_if_data *scan_sdata; 75 76 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL) 77 bss_meta.signal = 0; /* invalid signal indication */ 78 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM)) 79 bss_meta.signal = rx_status->signal * 100; 80 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC)) 81 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal; 82 83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20; 84 if (rx_status->bw == RATE_INFO_BW_5) 85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5; 86 else if (rx_status->bw == RATE_INFO_BW_10) 87 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10; 88 89 bss_meta.chan = channel; 90 91 rcu_read_lock(); 92 scan_sdata = rcu_dereference(local->scan_sdata); 93 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION && 94 scan_sdata->vif.bss_conf.assoc && 95 ieee80211_have_rx_timestamp(rx_status)) { 96 bss_meta.parent_tsf = 97 ieee80211_calculate_rx_timestamp(local, rx_status, 98 len + FCS_LEN, 24); 99 ether_addr_copy(bss_meta.parent_bssid, 100 scan_sdata->vif.bss_conf.bssid); 101 } 102 rcu_read_unlock(); 103 104 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, 105 mgmt, len, GFP_ATOMIC); 106 if (!cbss) 107 return NULL; 108 /* In case the signal is invalid update the status */ 109 signal_valid = abs(channel->center_freq - cbss->channel->center_freq) 110 <= local->hw.wiphy->max_adj_channel_rssi_comp; 111 if (!signal_valid) 112 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL; 113 114 bss = (void *)cbss->priv; 115 116 if (beacon) 117 bss->device_ts_beacon = rx_status->device_timestamp; 118 else 119 bss->device_ts_presp = rx_status->device_timestamp; 120 121 if (elems->parse_error) { 122 if (beacon) 123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 124 else 125 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 126 } else { 127 if (beacon) 128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 129 else 130 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 131 } 132 133 /* save the ERP value so that it is available at association time */ 134 if (elems->erp_info && (!elems->parse_error || 135 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 136 bss->erp_value = elems->erp_info[0]; 137 bss->has_erp_value = true; 138 if (!elems->parse_error) 139 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 140 } 141 142 /* replace old supported rates if we get new values */ 143 if (!elems->parse_error || 144 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 145 srlen = 0; 146 if (elems->supp_rates) { 147 clen = IEEE80211_MAX_SUPP_RATES; 148 if (clen > elems->supp_rates_len) 149 clen = elems->supp_rates_len; 150 memcpy(bss->supp_rates, elems->supp_rates, clen); 151 srlen += clen; 152 } 153 if (elems->ext_supp_rates) { 154 clen = IEEE80211_MAX_SUPP_RATES - srlen; 155 if (clen > elems->ext_supp_rates_len) 156 clen = elems->ext_supp_rates_len; 157 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 158 clen); 159 srlen += clen; 160 } 161 if (srlen) { 162 bss->supp_rates_len = srlen; 163 if (!elems->parse_error) 164 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 165 } 166 } 167 168 if (!elems->parse_error || 169 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 170 bss->wmm_used = elems->wmm_param || elems->wmm_info; 171 bss->uapsd_supported = is_uapsd_supported(elems); 172 if (!elems->parse_error) 173 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 174 } 175 176 if (beacon) { 177 struct ieee80211_supported_band *sband = 178 local->hw.wiphy->bands[rx_status->band]; 179 if (!(rx_status->encoding == RX_ENC_HT) && 180 !(rx_status->encoding == RX_ENC_VHT)) 181 bss->beacon_rate = 182 &sband->bitrates[rx_status->rate_idx]; 183 } 184 185 return bss; 186 } 187 188 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata, 189 u32 scan_flags, const u8 *da) 190 { 191 if (!sdata) 192 return false; 193 /* accept broadcast for OCE */ 194 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP && 195 is_broadcast_ether_addr(da)) 196 return true; 197 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR) 198 return true; 199 return ether_addr_equal(da, sdata->vif.addr); 200 } 201 202 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) 203 { 204 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 205 struct ieee80211_sub_if_data *sdata1, *sdata2; 206 struct ieee80211_mgmt *mgmt = (void *)skb->data; 207 struct ieee80211_bss *bss; 208 u8 *elements; 209 struct ieee80211_channel *channel; 210 size_t baselen; 211 struct ieee802_11_elems elems; 212 213 if (skb->len < 24 || 214 (!ieee80211_is_probe_resp(mgmt->frame_control) && 215 !ieee80211_is_beacon(mgmt->frame_control))) 216 return; 217 218 sdata1 = rcu_dereference(local->scan_sdata); 219 sdata2 = rcu_dereference(local->sched_scan_sdata); 220 221 if (likely(!sdata1 && !sdata2)) 222 return; 223 224 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 225 struct cfg80211_scan_request *scan_req; 226 struct cfg80211_sched_scan_request *sched_scan_req; 227 u32 scan_req_flags = 0, sched_scan_req_flags = 0; 228 229 scan_req = rcu_dereference(local->scan_req); 230 sched_scan_req = rcu_dereference(local->sched_scan_req); 231 232 if (scan_req) 233 scan_req_flags = scan_req->flags; 234 235 if (sched_scan_req) 236 sched_scan_req_flags = sched_scan_req->flags; 237 238 /* ignore ProbeResp to foreign address or non-bcast (OCE) 239 * unless scanning with randomised address 240 */ 241 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags, 242 mgmt->da) && 243 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags, 244 mgmt->da)) 245 return; 246 247 elements = mgmt->u.probe_resp.variable; 248 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 249 } else { 250 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 251 elements = mgmt->u.beacon.variable; 252 } 253 254 if (baselen > skb->len) 255 return; 256 257 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); 258 259 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); 260 261 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 262 return; 263 264 bss = ieee80211_bss_info_update(local, rx_status, 265 mgmt, skb->len, &elems, 266 channel); 267 if (bss) 268 ieee80211_rx_bss_put(local, bss); 269 } 270 271 static void 272 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, 273 enum nl80211_bss_scan_width scan_width) 274 { 275 memset(chandef, 0, sizeof(*chandef)); 276 switch (scan_width) { 277 case NL80211_BSS_CHAN_WIDTH_5: 278 chandef->width = NL80211_CHAN_WIDTH_5; 279 break; 280 case NL80211_BSS_CHAN_WIDTH_10: 281 chandef->width = NL80211_CHAN_WIDTH_10; 282 break; 283 default: 284 chandef->width = NL80211_CHAN_WIDTH_20_NOHT; 285 break; 286 } 287 } 288 289 /* return false if no more work */ 290 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 291 { 292 struct cfg80211_scan_request *req; 293 struct cfg80211_chan_def chandef; 294 u8 bands_used = 0; 295 int i, ielen, n_chans; 296 297 req = rcu_dereference_protected(local->scan_req, 298 lockdep_is_held(&local->mtx)); 299 300 if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) 301 return false; 302 303 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { 304 for (i = 0; i < req->n_channels; i++) { 305 local->hw_scan_req->req.channels[i] = req->channels[i]; 306 bands_used |= BIT(req->channels[i]->band); 307 } 308 309 n_chans = req->n_channels; 310 } else { 311 do { 312 if (local->hw_scan_band == NUM_NL80211_BANDS) 313 return false; 314 315 n_chans = 0; 316 317 for (i = 0; i < req->n_channels; i++) { 318 if (req->channels[i]->band != 319 local->hw_scan_band) 320 continue; 321 local->hw_scan_req->req.channels[n_chans] = 322 req->channels[i]; 323 n_chans++; 324 bands_used |= BIT(req->channels[i]->band); 325 } 326 327 local->hw_scan_band++; 328 } while (!n_chans); 329 } 330 331 local->hw_scan_req->req.n_channels = n_chans; 332 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 333 334 ielen = ieee80211_build_preq_ies(local, 335 (u8 *)local->hw_scan_req->req.ie, 336 local->hw_scan_ies_bufsize, 337 &local->hw_scan_req->ies, 338 req->ie, req->ie_len, 339 bands_used, req->rates, &chandef); 340 local->hw_scan_req->req.ie_len = ielen; 341 local->hw_scan_req->req.no_cck = req->no_cck; 342 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr); 343 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask, 344 req->mac_addr_mask); 345 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid); 346 347 return true; 348 } 349 350 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 351 { 352 struct ieee80211_local *local = hw_to_local(hw); 353 bool hw_scan = local->ops->hw_scan; 354 bool was_scanning = local->scanning; 355 struct cfg80211_scan_request *scan_req; 356 struct ieee80211_sub_if_data *scan_sdata; 357 struct ieee80211_sub_if_data *sdata; 358 359 lockdep_assert_held(&local->mtx); 360 361 /* 362 * It's ok to abort a not-yet-running scan (that 363 * we have one at all will be verified by checking 364 * local->scan_req next), but not to complete it 365 * successfully. 366 */ 367 if (WARN_ON(!local->scanning && !aborted)) 368 aborted = true; 369 370 if (WARN_ON(!local->scan_req)) 371 return; 372 373 if (hw_scan && !aborted && 374 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) && 375 ieee80211_prep_hw_scan(local)) { 376 int rc; 377 378 rc = drv_hw_scan(local, 379 rcu_dereference_protected(local->scan_sdata, 380 lockdep_is_held(&local->mtx)), 381 local->hw_scan_req); 382 383 if (rc == 0) 384 return; 385 386 /* HW scan failed and is going to be reported as aborted, 387 * so clear old scan info. 388 */ 389 memset(&local->scan_info, 0, sizeof(local->scan_info)); 390 aborted = true; 391 } 392 393 kfree(local->hw_scan_req); 394 local->hw_scan_req = NULL; 395 396 scan_req = rcu_dereference_protected(local->scan_req, 397 lockdep_is_held(&local->mtx)); 398 399 if (scan_req != local->int_scan_req) { 400 local->scan_info.aborted = aborted; 401 cfg80211_scan_done(scan_req, &local->scan_info); 402 } 403 RCU_INIT_POINTER(local->scan_req, NULL); 404 405 scan_sdata = rcu_dereference_protected(local->scan_sdata, 406 lockdep_is_held(&local->mtx)); 407 RCU_INIT_POINTER(local->scan_sdata, NULL); 408 409 local->scanning = 0; 410 local->scan_chandef.chan = NULL; 411 412 /* Set power back to normal operating levels. */ 413 ieee80211_hw_config(local, 0); 414 415 if (!hw_scan) { 416 ieee80211_configure_filter(local); 417 drv_sw_scan_complete(local, scan_sdata); 418 ieee80211_offchannel_return(local); 419 } 420 421 ieee80211_recalc_idle(local); 422 423 ieee80211_mlme_notify_scan_completed(local); 424 ieee80211_ibss_notify_scan_completed(local); 425 426 /* Requeue all the work that might have been ignored while 427 * the scan was in progress; if there was none this will 428 * just be a no-op for the particular interface. 429 */ 430 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 431 if (ieee80211_sdata_running(sdata)) 432 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 433 } 434 435 if (was_scanning) 436 ieee80211_start_next_roc(local); 437 } 438 439 void ieee80211_scan_completed(struct ieee80211_hw *hw, 440 struct cfg80211_scan_info *info) 441 { 442 struct ieee80211_local *local = hw_to_local(hw); 443 444 trace_api_scan_completed(local, info->aborted); 445 446 set_bit(SCAN_COMPLETED, &local->scanning); 447 if (info->aborted) 448 set_bit(SCAN_ABORTED, &local->scanning); 449 450 memcpy(&local->scan_info, info, sizeof(*info)); 451 452 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 453 } 454 EXPORT_SYMBOL(ieee80211_scan_completed); 455 456 static int ieee80211_start_sw_scan(struct ieee80211_local *local, 457 struct ieee80211_sub_if_data *sdata) 458 { 459 /* Software scan is not supported in multi-channel cases */ 460 if (local->use_chanctx) 461 return -EOPNOTSUPP; 462 463 /* 464 * Hardware/driver doesn't support hw_scan, so use software 465 * scanning instead. First send a nullfunc frame with power save 466 * bit on so that AP will buffer the frames for us while we are not 467 * listening, then send probe requests to each channel and wait for 468 * the responses. After all channels are scanned, tune back to the 469 * original channel and send a nullfunc frame with power save bit 470 * off to trigger the AP to send us all the buffered frames. 471 * 472 * Note that while local->sw_scanning is true everything else but 473 * nullfunc frames and probe requests will be dropped in 474 * ieee80211_tx_h_check_assoc(). 475 */ 476 drv_sw_scan_start(local, sdata, local->scan_addr); 477 478 local->leave_oper_channel_time = jiffies; 479 local->next_scan_state = SCAN_DECISION; 480 local->scan_channel_idx = 0; 481 482 ieee80211_offchannel_stop_vifs(local); 483 484 /* ensure nullfunc is transmitted before leaving operating channel */ 485 ieee80211_flush_queues(local, NULL, false); 486 487 ieee80211_configure_filter(local); 488 489 /* We need to set power level at maximum rate for scanning. */ 490 ieee80211_hw_config(local, 0); 491 492 ieee80211_queue_delayed_work(&local->hw, 493 &local->scan_work, 0); 494 495 return 0; 496 } 497 498 static bool ieee80211_can_scan(struct ieee80211_local *local, 499 struct ieee80211_sub_if_data *sdata) 500 { 501 if (ieee80211_is_radar_required(local)) 502 return false; 503 504 if (!list_empty(&local->roc_list)) 505 return false; 506 507 if (sdata->vif.type == NL80211_IFTYPE_STATION && 508 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) 509 return false; 510 511 return true; 512 } 513 514 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 515 { 516 lockdep_assert_held(&local->mtx); 517 518 if (!local->scan_req || local->scanning) 519 return; 520 521 if (!ieee80211_can_scan(local, 522 rcu_dereference_protected( 523 local->scan_sdata, 524 lockdep_is_held(&local->mtx)))) 525 return; 526 527 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 528 round_jiffies_relative(0)); 529 } 530 531 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 532 unsigned long *next_delay) 533 { 534 int i; 535 struct ieee80211_sub_if_data *sdata; 536 struct cfg80211_scan_request *scan_req; 537 enum nl80211_band band = local->hw.conf.chandef.chan->band; 538 u32 tx_flags; 539 540 scan_req = rcu_dereference_protected(local->scan_req, 541 lockdep_is_held(&local->mtx)); 542 543 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; 544 if (scan_req->no_cck) 545 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; 546 547 sdata = rcu_dereference_protected(local->scan_sdata, 548 lockdep_is_held(&local->mtx)); 549 550 for (i = 0; i < scan_req->n_ssids; i++) 551 ieee80211_send_probe_req( 552 sdata, local->scan_addr, scan_req->bssid, 553 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len, 554 scan_req->ie, scan_req->ie_len, 555 scan_req->rates[band], false, 556 tx_flags, local->hw.conf.chandef.chan, true); 557 558 /* 559 * After sending probe requests, wait for probe responses 560 * on the channel. 561 */ 562 *next_delay = IEEE80211_CHANNEL_TIME; 563 local->next_scan_state = SCAN_DECISION; 564 } 565 566 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 567 struct cfg80211_scan_request *req) 568 { 569 struct ieee80211_local *local = sdata->local; 570 int rc; 571 572 lockdep_assert_held(&local->mtx); 573 574 if (local->scan_req || ieee80211_is_radar_required(local)) 575 return -EBUSY; 576 577 if (!ieee80211_can_scan(local, sdata)) { 578 /* wait for the work to finish/time out */ 579 rcu_assign_pointer(local->scan_req, req); 580 rcu_assign_pointer(local->scan_sdata, sdata); 581 return 0; 582 } 583 584 if (local->ops->hw_scan) { 585 u8 *ies; 586 587 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; 588 589 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { 590 int i, n_bands = 0; 591 u8 bands_counted = 0; 592 593 for (i = 0; i < req->n_channels; i++) { 594 if (bands_counted & BIT(req->channels[i]->band)) 595 continue; 596 bands_counted |= BIT(req->channels[i]->band); 597 n_bands++; 598 } 599 600 local->hw_scan_ies_bufsize *= n_bands; 601 } 602 603 local->hw_scan_req = kmalloc( 604 sizeof(*local->hw_scan_req) + 605 req->n_channels * sizeof(req->channels[0]) + 606 local->hw_scan_ies_bufsize, GFP_KERNEL); 607 if (!local->hw_scan_req) 608 return -ENOMEM; 609 610 local->hw_scan_req->req.ssids = req->ssids; 611 local->hw_scan_req->req.n_ssids = req->n_ssids; 612 ies = (u8 *)local->hw_scan_req + 613 sizeof(*local->hw_scan_req) + 614 req->n_channels * sizeof(req->channels[0]); 615 local->hw_scan_req->req.ie = ies; 616 local->hw_scan_req->req.flags = req->flags; 617 eth_broadcast_addr(local->hw_scan_req->req.bssid); 618 local->hw_scan_req->req.duration = req->duration; 619 local->hw_scan_req->req.duration_mandatory = 620 req->duration_mandatory; 621 622 local->hw_scan_band = 0; 623 624 /* 625 * After allocating local->hw_scan_req, we must 626 * go through until ieee80211_prep_hw_scan(), so 627 * anything that might be changed here and leave 628 * this function early must not go after this 629 * allocation. 630 */ 631 } 632 633 rcu_assign_pointer(local->scan_req, req); 634 rcu_assign_pointer(local->scan_sdata, sdata); 635 636 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) 637 get_random_mask_addr(local->scan_addr, 638 req->mac_addr, 639 req->mac_addr_mask); 640 else 641 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN); 642 643 if (local->ops->hw_scan) { 644 __set_bit(SCAN_HW_SCANNING, &local->scanning); 645 } else if ((req->n_channels == 1) && 646 (req->channels[0] == local->_oper_chandef.chan)) { 647 /* 648 * If we are scanning only on the operating channel 649 * then we do not need to stop normal activities 650 */ 651 unsigned long next_delay; 652 653 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 654 655 ieee80211_recalc_idle(local); 656 657 /* Notify driver scan is starting, keep order of operations 658 * same as normal software scan, in case that matters. */ 659 drv_sw_scan_start(local, sdata, local->scan_addr); 660 661 ieee80211_configure_filter(local); /* accept probe-responses */ 662 663 /* We need to ensure power level is at max for scanning. */ 664 ieee80211_hw_config(local, 0); 665 666 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR | 667 IEEE80211_CHAN_RADAR)) || 668 !req->n_ssids) { 669 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 670 } else { 671 ieee80211_scan_state_send_probe(local, &next_delay); 672 next_delay = IEEE80211_CHANNEL_TIME; 673 } 674 675 /* Now, just wait a bit and we are all done! */ 676 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 677 next_delay); 678 return 0; 679 } else { 680 /* Do normal software scan */ 681 __set_bit(SCAN_SW_SCANNING, &local->scanning); 682 } 683 684 ieee80211_recalc_idle(local); 685 686 if (local->ops->hw_scan) { 687 WARN_ON(!ieee80211_prep_hw_scan(local)); 688 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 689 } else { 690 rc = ieee80211_start_sw_scan(local, sdata); 691 } 692 693 if (rc) { 694 kfree(local->hw_scan_req); 695 local->hw_scan_req = NULL; 696 local->scanning = 0; 697 698 ieee80211_recalc_idle(local); 699 700 local->scan_req = NULL; 701 RCU_INIT_POINTER(local->scan_sdata, NULL); 702 } 703 704 return rc; 705 } 706 707 static unsigned long 708 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 709 { 710 /* 711 * TODO: channel switching also consumes quite some time, 712 * add that delay as well to get a better estimation 713 */ 714 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) 715 return IEEE80211_PASSIVE_CHANNEL_TIME; 716 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 717 } 718 719 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 720 unsigned long *next_delay) 721 { 722 bool associated = false; 723 bool tx_empty = true; 724 bool bad_latency; 725 struct ieee80211_sub_if_data *sdata; 726 struct ieee80211_channel *next_chan; 727 enum mac80211_scan_state next_scan_state; 728 struct cfg80211_scan_request *scan_req; 729 730 /* 731 * check if at least one STA interface is associated, 732 * check if at least one STA interface has pending tx frames 733 * and grab the lowest used beacon interval 734 */ 735 mutex_lock(&local->iflist_mtx); 736 list_for_each_entry(sdata, &local->interfaces, list) { 737 if (!ieee80211_sdata_running(sdata)) 738 continue; 739 740 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 741 if (sdata->u.mgd.associated) { 742 associated = true; 743 744 if (!qdisc_all_tx_empty(sdata->dev)) { 745 tx_empty = false; 746 break; 747 } 748 } 749 } 750 } 751 mutex_unlock(&local->iflist_mtx); 752 753 scan_req = rcu_dereference_protected(local->scan_req, 754 lockdep_is_held(&local->mtx)); 755 756 next_chan = scan_req->channels[local->scan_channel_idx]; 757 758 /* 759 * we're currently scanning a different channel, let's 760 * see if we can scan another channel without interfering 761 * with the current traffic situation. 762 * 763 * Keep good latency, do not stay off-channel more than 125 ms. 764 */ 765 766 bad_latency = time_after(jiffies + 767 ieee80211_scan_get_channel_time(next_chan), 768 local->leave_oper_channel_time + HZ / 8); 769 770 if (associated && !tx_empty) { 771 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) 772 next_scan_state = SCAN_ABORT; 773 else 774 next_scan_state = SCAN_SUSPEND; 775 } else if (associated && bad_latency) { 776 next_scan_state = SCAN_SUSPEND; 777 } else { 778 next_scan_state = SCAN_SET_CHANNEL; 779 } 780 781 local->next_scan_state = next_scan_state; 782 783 *next_delay = 0; 784 } 785 786 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 787 unsigned long *next_delay) 788 { 789 int skip; 790 struct ieee80211_channel *chan; 791 enum nl80211_bss_scan_width oper_scan_width; 792 struct cfg80211_scan_request *scan_req; 793 794 scan_req = rcu_dereference_protected(local->scan_req, 795 lockdep_is_held(&local->mtx)); 796 797 skip = 0; 798 chan = scan_req->channels[local->scan_channel_idx]; 799 800 local->scan_chandef.chan = chan; 801 local->scan_chandef.center_freq1 = chan->center_freq; 802 local->scan_chandef.center_freq2 = 0; 803 switch (scan_req->scan_width) { 804 case NL80211_BSS_CHAN_WIDTH_5: 805 local->scan_chandef.width = NL80211_CHAN_WIDTH_5; 806 break; 807 case NL80211_BSS_CHAN_WIDTH_10: 808 local->scan_chandef.width = NL80211_CHAN_WIDTH_10; 809 break; 810 case NL80211_BSS_CHAN_WIDTH_20: 811 /* If scanning on oper channel, use whatever channel-type 812 * is currently in use. 813 */ 814 oper_scan_width = cfg80211_chandef_to_scan_width( 815 &local->_oper_chandef); 816 if (chan == local->_oper_chandef.chan && 817 oper_scan_width == scan_req->scan_width) 818 local->scan_chandef = local->_oper_chandef; 819 else 820 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; 821 break; 822 } 823 824 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 825 skip = 1; 826 827 /* advance state machine to next channel/band */ 828 local->scan_channel_idx++; 829 830 if (skip) { 831 /* if we skip this channel return to the decision state */ 832 local->next_scan_state = SCAN_DECISION; 833 return; 834 } 835 836 /* 837 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 838 * (which unfortunately doesn't say _why_ step a) is done, 839 * but it waits for the probe delay or until a frame is 840 * received - and the received frame would update the NAV). 841 * For now, we do not support waiting until a frame is 842 * received. 843 * 844 * In any case, it is not necessary for a passive scan. 845 */ 846 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) || 847 !scan_req->n_ssids) { 848 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 849 local->next_scan_state = SCAN_DECISION; 850 return; 851 } 852 853 /* active scan, send probes */ 854 *next_delay = IEEE80211_PROBE_DELAY; 855 local->next_scan_state = SCAN_SEND_PROBE; 856 } 857 858 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 859 unsigned long *next_delay) 860 { 861 /* switch back to the operating channel */ 862 local->scan_chandef.chan = NULL; 863 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 864 865 /* disable PS */ 866 ieee80211_offchannel_return(local); 867 868 *next_delay = HZ / 5; 869 /* afterwards, resume scan & go to next channel */ 870 local->next_scan_state = SCAN_RESUME; 871 } 872 873 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 874 unsigned long *next_delay) 875 { 876 ieee80211_offchannel_stop_vifs(local); 877 878 if (local->ops->flush) { 879 ieee80211_flush_queues(local, NULL, false); 880 *next_delay = 0; 881 } else 882 *next_delay = HZ / 10; 883 884 /* remember when we left the operating channel */ 885 local->leave_oper_channel_time = jiffies; 886 887 /* advance to the next channel to be scanned */ 888 local->next_scan_state = SCAN_SET_CHANNEL; 889 } 890 891 void ieee80211_scan_work(struct work_struct *work) 892 { 893 struct ieee80211_local *local = 894 container_of(work, struct ieee80211_local, scan_work.work); 895 struct ieee80211_sub_if_data *sdata; 896 struct cfg80211_scan_request *scan_req; 897 unsigned long next_delay = 0; 898 bool aborted; 899 900 mutex_lock(&local->mtx); 901 902 if (!ieee80211_can_run_worker(local)) { 903 aborted = true; 904 goto out_complete; 905 } 906 907 sdata = rcu_dereference_protected(local->scan_sdata, 908 lockdep_is_held(&local->mtx)); 909 scan_req = rcu_dereference_protected(local->scan_req, 910 lockdep_is_held(&local->mtx)); 911 912 /* When scanning on-channel, the first-callback means completed. */ 913 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 914 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 915 goto out_complete; 916 } 917 918 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 919 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 920 goto out_complete; 921 } 922 923 if (!sdata || !scan_req) 924 goto out; 925 926 if (!local->scanning) { 927 int rc; 928 929 RCU_INIT_POINTER(local->scan_req, NULL); 930 RCU_INIT_POINTER(local->scan_sdata, NULL); 931 932 rc = __ieee80211_start_scan(sdata, scan_req); 933 if (rc) { 934 /* need to complete scan in cfg80211 */ 935 rcu_assign_pointer(local->scan_req, scan_req); 936 aborted = true; 937 goto out_complete; 938 } else 939 goto out; 940 } 941 942 /* 943 * as long as no delay is required advance immediately 944 * without scheduling a new work 945 */ 946 do { 947 if (!ieee80211_sdata_running(sdata)) { 948 aborted = true; 949 goto out_complete; 950 } 951 952 switch (local->next_scan_state) { 953 case SCAN_DECISION: 954 /* if no more bands/channels left, complete scan */ 955 if (local->scan_channel_idx >= scan_req->n_channels) { 956 aborted = false; 957 goto out_complete; 958 } 959 ieee80211_scan_state_decision(local, &next_delay); 960 break; 961 case SCAN_SET_CHANNEL: 962 ieee80211_scan_state_set_channel(local, &next_delay); 963 break; 964 case SCAN_SEND_PROBE: 965 ieee80211_scan_state_send_probe(local, &next_delay); 966 break; 967 case SCAN_SUSPEND: 968 ieee80211_scan_state_suspend(local, &next_delay); 969 break; 970 case SCAN_RESUME: 971 ieee80211_scan_state_resume(local, &next_delay); 972 break; 973 case SCAN_ABORT: 974 aborted = true; 975 goto out_complete; 976 } 977 } while (next_delay == 0); 978 979 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 980 goto out; 981 982 out_complete: 983 __ieee80211_scan_completed(&local->hw, aborted); 984 out: 985 mutex_unlock(&local->mtx); 986 } 987 988 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 989 struct cfg80211_scan_request *req) 990 { 991 int res; 992 993 mutex_lock(&sdata->local->mtx); 994 res = __ieee80211_start_scan(sdata, req); 995 mutex_unlock(&sdata->local->mtx); 996 997 return res; 998 } 999 1000 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, 1001 const u8 *ssid, u8 ssid_len, 1002 struct ieee80211_channel **channels, 1003 unsigned int n_channels, 1004 enum nl80211_bss_scan_width scan_width) 1005 { 1006 struct ieee80211_local *local = sdata->local; 1007 int ret = -EBUSY, i, n_ch = 0; 1008 enum nl80211_band band; 1009 1010 mutex_lock(&local->mtx); 1011 1012 /* busy scanning */ 1013 if (local->scan_req) 1014 goto unlock; 1015 1016 /* fill internal scan request */ 1017 if (!channels) { 1018 int max_n; 1019 1020 for (band = 0; band < NUM_NL80211_BANDS; band++) { 1021 if (!local->hw.wiphy->bands[band]) 1022 continue; 1023 1024 max_n = local->hw.wiphy->bands[band]->n_channels; 1025 for (i = 0; i < max_n; i++) { 1026 struct ieee80211_channel *tmp_ch = 1027 &local->hw.wiphy->bands[band]->channels[i]; 1028 1029 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | 1030 IEEE80211_CHAN_DISABLED)) 1031 continue; 1032 1033 local->int_scan_req->channels[n_ch] = tmp_ch; 1034 n_ch++; 1035 } 1036 } 1037 1038 if (WARN_ON_ONCE(n_ch == 0)) 1039 goto unlock; 1040 1041 local->int_scan_req->n_channels = n_ch; 1042 } else { 1043 for (i = 0; i < n_channels; i++) { 1044 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR | 1045 IEEE80211_CHAN_DISABLED)) 1046 continue; 1047 1048 local->int_scan_req->channels[n_ch] = channels[i]; 1049 n_ch++; 1050 } 1051 1052 if (WARN_ON_ONCE(n_ch == 0)) 1053 goto unlock; 1054 1055 local->int_scan_req->n_channels = n_ch; 1056 } 1057 1058 local->int_scan_req->ssids = &local->scan_ssid; 1059 local->int_scan_req->n_ssids = 1; 1060 local->int_scan_req->scan_width = scan_width; 1061 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 1062 local->int_scan_req->ssids[0].ssid_len = ssid_len; 1063 1064 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 1065 unlock: 1066 mutex_unlock(&local->mtx); 1067 return ret; 1068 } 1069 1070 /* 1071 * Only call this function when a scan can't be queued -- under RTNL. 1072 */ 1073 void ieee80211_scan_cancel(struct ieee80211_local *local) 1074 { 1075 /* 1076 * We are canceling software scan, or deferred scan that was not 1077 * yet really started (see __ieee80211_start_scan ). 1078 * 1079 * Regarding hardware scan: 1080 * - we can not call __ieee80211_scan_completed() as when 1081 * SCAN_HW_SCANNING bit is set this function change 1082 * local->hw_scan_req to operate on 5G band, what race with 1083 * driver which can use local->hw_scan_req 1084 * 1085 * - we can not cancel scan_work since driver can schedule it 1086 * by ieee80211_scan_completed(..., true) to finish scan 1087 * 1088 * Hence we only call the cancel_hw_scan() callback, but the low-level 1089 * driver is still responsible for calling ieee80211_scan_completed() 1090 * after the scan was completed/aborted. 1091 */ 1092 1093 mutex_lock(&local->mtx); 1094 if (!local->scan_req) 1095 goto out; 1096 1097 /* 1098 * We have a scan running and the driver already reported completion, 1099 * but the worker hasn't run yet or is stuck on the mutex - mark it as 1100 * cancelled. 1101 */ 1102 if (test_bit(SCAN_HW_SCANNING, &local->scanning) && 1103 test_bit(SCAN_COMPLETED, &local->scanning)) { 1104 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1105 goto out; 1106 } 1107 1108 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 1109 /* 1110 * Make sure that __ieee80211_scan_completed doesn't trigger a 1111 * scan on another band. 1112 */ 1113 set_bit(SCAN_HW_CANCELLED, &local->scanning); 1114 if (local->ops->cancel_hw_scan) 1115 drv_cancel_hw_scan(local, 1116 rcu_dereference_protected(local->scan_sdata, 1117 lockdep_is_held(&local->mtx))); 1118 goto out; 1119 } 1120 1121 /* 1122 * If the work is currently running, it must be blocked on 1123 * the mutex, but we'll set scan_sdata = NULL and it'll 1124 * simply exit once it acquires the mutex. 1125 */ 1126 cancel_delayed_work(&local->scan_work); 1127 /* and clean up */ 1128 memset(&local->scan_info, 0, sizeof(local->scan_info)); 1129 __ieee80211_scan_completed(&local->hw, true); 1130 out: 1131 mutex_unlock(&local->mtx); 1132 } 1133 1134 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1135 struct cfg80211_sched_scan_request *req) 1136 { 1137 struct ieee80211_local *local = sdata->local; 1138 struct ieee80211_scan_ies sched_scan_ies = {}; 1139 struct cfg80211_chan_def chandef; 1140 int ret, i, iebufsz, num_bands = 0; 1141 u32 rate_masks[NUM_NL80211_BANDS] = {}; 1142 u8 bands_used = 0; 1143 u8 *ie; 1144 1145 iebufsz = local->scan_ies_len + req->ie_len; 1146 1147 lockdep_assert_held(&local->mtx); 1148 1149 if (!local->ops->sched_scan_start) 1150 return -ENOTSUPP; 1151 1152 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1153 if (local->hw.wiphy->bands[i]) { 1154 bands_used |= BIT(i); 1155 rate_masks[i] = (u32) -1; 1156 num_bands++; 1157 } 1158 } 1159 1160 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL); 1161 if (!ie) { 1162 ret = -ENOMEM; 1163 goto out; 1164 } 1165 1166 ieee80211_prepare_scan_chandef(&chandef, req->scan_width); 1167 1168 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz, 1169 &sched_scan_ies, req->ie, 1170 req->ie_len, bands_used, rate_masks, &chandef); 1171 1172 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); 1173 if (ret == 0) { 1174 rcu_assign_pointer(local->sched_scan_sdata, sdata); 1175 rcu_assign_pointer(local->sched_scan_req, req); 1176 } 1177 1178 kfree(ie); 1179 1180 out: 1181 if (ret) { 1182 /* Clean in case of failure after HW restart or upon resume. */ 1183 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1184 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1185 } 1186 1187 return ret; 1188 } 1189 1190 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 1191 struct cfg80211_sched_scan_request *req) 1192 { 1193 struct ieee80211_local *local = sdata->local; 1194 int ret; 1195 1196 mutex_lock(&local->mtx); 1197 1198 if (rcu_access_pointer(local->sched_scan_sdata)) { 1199 mutex_unlock(&local->mtx); 1200 return -EBUSY; 1201 } 1202 1203 ret = __ieee80211_request_sched_scan_start(sdata, req); 1204 1205 mutex_unlock(&local->mtx); 1206 return ret; 1207 } 1208 1209 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local) 1210 { 1211 struct ieee80211_sub_if_data *sched_scan_sdata; 1212 int ret = -ENOENT; 1213 1214 mutex_lock(&local->mtx); 1215 1216 if (!local->ops->sched_scan_stop) { 1217 ret = -ENOTSUPP; 1218 goto out; 1219 } 1220 1221 /* We don't want to restart sched scan anymore. */ 1222 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1223 1224 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata, 1225 lockdep_is_held(&local->mtx)); 1226 if (sched_scan_sdata) { 1227 ret = drv_sched_scan_stop(local, sched_scan_sdata); 1228 if (!ret) 1229 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1230 } 1231 out: 1232 mutex_unlock(&local->mtx); 1233 1234 return ret; 1235 } 1236 1237 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 1238 { 1239 struct ieee80211_local *local = hw_to_local(hw); 1240 1241 trace_api_sched_scan_results(local); 1242 1243 cfg80211_sched_scan_results(hw->wiphy, 0); 1244 } 1245 EXPORT_SYMBOL(ieee80211_sched_scan_results); 1246 1247 void ieee80211_sched_scan_end(struct ieee80211_local *local) 1248 { 1249 mutex_lock(&local->mtx); 1250 1251 if (!rcu_access_pointer(local->sched_scan_sdata)) { 1252 mutex_unlock(&local->mtx); 1253 return; 1254 } 1255 1256 RCU_INIT_POINTER(local->sched_scan_sdata, NULL); 1257 1258 /* If sched scan was aborted by the driver. */ 1259 RCU_INIT_POINTER(local->sched_scan_req, NULL); 1260 1261 mutex_unlock(&local->mtx); 1262 1263 cfg80211_sched_scan_stopped(local->hw.wiphy, 0); 1264 } 1265 1266 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 1267 { 1268 struct ieee80211_local *local = 1269 container_of(work, struct ieee80211_local, 1270 sched_scan_stopped_work); 1271 1272 ieee80211_sched_scan_end(local); 1273 } 1274 1275 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1276 { 1277 struct ieee80211_local *local = hw_to_local(hw); 1278 1279 trace_api_sched_scan_stopped(local); 1280 1281 /* 1282 * this shouldn't really happen, so for simplicity 1283 * simply ignore it, and let mac80211 reconfigure 1284 * the sched scan later on. 1285 */ 1286 if (local->in_reconfig) 1287 return; 1288 1289 schedule_work(&local->sched_scan_stopped_work); 1290 } 1291 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1292