1 /* 2 * Scanning implementation 3 * 4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 5 * Copyright 2004, Instant802 Networks, Inc. 6 * Copyright 2005, Devicescape Software, Inc. 7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/if_arp.h> 16 #include <linux/rtnetlink.h> 17 #include <linux/pm_qos.h> 18 #include <net/sch_generic.h> 19 #include <linux/slab.h> 20 #include <linux/export.h> 21 #include <net/mac80211.h> 22 23 #include "ieee80211_i.h" 24 #include "driver-ops.h" 25 #include "mesh.h" 26 27 #define IEEE80211_PROBE_DELAY (HZ / 33) 28 #define IEEE80211_CHANNEL_TIME (HZ / 33) 29 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) 30 31 struct ieee80211_bss * 32 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, 33 u8 *ssid, u8 ssid_len) 34 { 35 struct cfg80211_bss *cbss; 36 37 cbss = cfg80211_get_bss(local->hw.wiphy, 38 ieee80211_get_channel(local->hw.wiphy, freq), 39 bssid, ssid, ssid_len, 0, 0); 40 if (!cbss) 41 return NULL; 42 return (void *)cbss->priv; 43 } 44 45 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) 46 { 47 struct ieee80211_bss *bss = (void *)cbss->priv; 48 49 kfree(bss_mesh_id(bss)); 50 kfree(bss_mesh_cfg(bss)); 51 } 52 53 void ieee80211_rx_bss_put(struct ieee80211_local *local, 54 struct ieee80211_bss *bss) 55 { 56 if (!bss) 57 return; 58 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); 59 } 60 61 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 62 { 63 u8 qos_info; 64 65 if (elems->wmm_info && elems->wmm_info_len == 7 66 && elems->wmm_info[5] == 1) 67 qos_info = elems->wmm_info[6]; 68 else if (elems->wmm_param && elems->wmm_param_len == 24 69 && elems->wmm_param[5] == 1) 70 qos_info = elems->wmm_param[6]; 71 else 72 /* no valid wmm information or parameter element found */ 73 return false; 74 75 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 76 } 77 78 struct ieee80211_bss * 79 ieee80211_bss_info_update(struct ieee80211_local *local, 80 struct ieee80211_rx_status *rx_status, 81 struct ieee80211_mgmt *mgmt, 82 size_t len, 83 struct ieee802_11_elems *elems, 84 struct ieee80211_channel *channel, 85 bool beacon) 86 { 87 struct cfg80211_bss *cbss; 88 struct ieee80211_bss *bss; 89 int clen, srlen; 90 s32 signal = 0; 91 92 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 93 signal = rx_status->signal * 100; 94 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 95 signal = (rx_status->signal * 100) / local->hw.max_signal; 96 97 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, 98 mgmt, len, signal, GFP_ATOMIC); 99 100 if (!cbss) 101 return NULL; 102 103 cbss->free_priv = ieee80211_rx_bss_free; 104 bss = (void *)cbss->priv; 105 106 /* save the ERP value so that it is available at association time */ 107 if (elems->erp_info && elems->erp_info_len >= 1) { 108 bss->erp_value = elems->erp_info[0]; 109 bss->has_erp_value = true; 110 } 111 112 if (elems->tim) { 113 struct ieee80211_tim_ie *tim_ie = 114 (struct ieee80211_tim_ie *)elems->tim; 115 bss->dtim_period = tim_ie->dtim_period; 116 } 117 118 /* If the beacon had no TIM IE, or it was invalid, use 1 */ 119 if (beacon && !bss->dtim_period) 120 bss->dtim_period = 1; 121 122 /* replace old supported rates if we get new values */ 123 srlen = 0; 124 if (elems->supp_rates) { 125 clen = IEEE80211_MAX_SUPP_RATES; 126 if (clen > elems->supp_rates_len) 127 clen = elems->supp_rates_len; 128 memcpy(bss->supp_rates, elems->supp_rates, clen); 129 srlen += clen; 130 } 131 if (elems->ext_supp_rates) { 132 clen = IEEE80211_MAX_SUPP_RATES - srlen; 133 if (clen > elems->ext_supp_rates_len) 134 clen = elems->ext_supp_rates_len; 135 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); 136 srlen += clen; 137 } 138 if (srlen) 139 bss->supp_rates_len = srlen; 140 141 bss->wmm_used = elems->wmm_param || elems->wmm_info; 142 bss->uapsd_supported = is_uapsd_supported(elems); 143 144 if (!beacon) 145 bss->last_probe_resp = jiffies; 146 147 return bss; 148 } 149 150 ieee80211_rx_result 151 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 152 { 153 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 154 struct ieee80211_mgmt *mgmt; 155 struct ieee80211_bss *bss; 156 u8 *elements; 157 struct ieee80211_channel *channel; 158 size_t baselen; 159 int freq; 160 __le16 fc; 161 bool presp, beacon = false; 162 struct ieee802_11_elems elems; 163 164 if (skb->len < 2) 165 return RX_DROP_UNUSABLE; 166 167 mgmt = (struct ieee80211_mgmt *) skb->data; 168 fc = mgmt->frame_control; 169 170 if (ieee80211_is_ctl(fc)) 171 return RX_CONTINUE; 172 173 if (skb->len < 24) 174 return RX_CONTINUE; 175 176 presp = ieee80211_is_probe_resp(fc); 177 if (presp) { 178 /* ignore ProbeResp to foreign address */ 179 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 180 return RX_DROP_MONITOR; 181 182 presp = true; 183 elements = mgmt->u.probe_resp.variable; 184 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 185 } else { 186 beacon = ieee80211_is_beacon(fc); 187 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 188 elements = mgmt->u.beacon.variable; 189 } 190 191 if (!presp && !beacon) 192 return RX_CONTINUE; 193 194 if (baselen > skb->len) 195 return RX_DROP_MONITOR; 196 197 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 198 199 if (elems.ds_params && elems.ds_params_len == 1) 200 freq = ieee80211_channel_to_frequency(elems.ds_params[0], 201 rx_status->band); 202 else 203 freq = rx_status->freq; 204 205 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 206 207 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 208 return RX_DROP_MONITOR; 209 210 bss = ieee80211_bss_info_update(sdata->local, rx_status, 211 mgmt, skb->len, &elems, 212 channel, beacon); 213 if (bss) 214 ieee80211_rx_bss_put(sdata->local, bss); 215 216 if (channel == sdata->local->oper_channel) 217 return RX_CONTINUE; 218 219 dev_kfree_skb(skb); 220 return RX_QUEUED; 221 } 222 223 /* return false if no more work */ 224 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 225 { 226 struct cfg80211_scan_request *req = local->scan_req; 227 enum ieee80211_band band; 228 int i, ielen, n_chans; 229 230 do { 231 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 232 return false; 233 234 band = local->hw_scan_band; 235 n_chans = 0; 236 for (i = 0; i < req->n_channels; i++) { 237 if (req->channels[i]->band == band) { 238 local->hw_scan_req->channels[n_chans] = 239 req->channels[i]; 240 n_chans++; 241 } 242 } 243 244 local->hw_scan_band++; 245 } while (!n_chans); 246 247 local->hw_scan_req->n_channels = n_chans; 248 249 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 250 req->ie, req->ie_len, band, 251 req->rates[band], 0); 252 local->hw_scan_req->ie_len = ielen; 253 local->hw_scan_req->no_cck = req->no_cck; 254 255 return true; 256 } 257 258 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 259 bool was_hw_scan) 260 { 261 struct ieee80211_local *local = hw_to_local(hw); 262 263 lockdep_assert_held(&local->mtx); 264 265 /* 266 * It's ok to abort a not-yet-running scan (that 267 * we have one at all will be verified by checking 268 * local->scan_req next), but not to complete it 269 * successfully. 270 */ 271 if (WARN_ON(!local->scanning && !aborted)) 272 aborted = true; 273 274 if (WARN_ON(!local->scan_req)) 275 return; 276 277 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 278 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); 279 if (rc == 0) 280 return; 281 } 282 283 kfree(local->hw_scan_req); 284 local->hw_scan_req = NULL; 285 286 if (local->scan_req != local->int_scan_req) 287 cfg80211_scan_done(local->scan_req, aborted); 288 local->scan_req = NULL; 289 local->scan_sdata = NULL; 290 291 local->scanning = 0; 292 local->scan_channel = NULL; 293 294 /* Set power back to normal operating levels. */ 295 ieee80211_hw_config(local, 0); 296 297 if (!was_hw_scan) { 298 ieee80211_configure_filter(local); 299 drv_sw_scan_complete(local); 300 ieee80211_offchannel_return(local, true); 301 } 302 303 ieee80211_recalc_idle(local); 304 305 ieee80211_mlme_notify_scan_completed(local); 306 ieee80211_ibss_notify_scan_completed(local); 307 ieee80211_mesh_notify_scan_completed(local); 308 ieee80211_queue_work(&local->hw, &local->work_work); 309 } 310 311 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 312 { 313 struct ieee80211_local *local = hw_to_local(hw); 314 315 trace_api_scan_completed(local, aborted); 316 317 set_bit(SCAN_COMPLETED, &local->scanning); 318 if (aborted) 319 set_bit(SCAN_ABORTED, &local->scanning); 320 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 321 } 322 EXPORT_SYMBOL(ieee80211_scan_completed); 323 324 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 325 { 326 /* 327 * Hardware/driver doesn't support hw_scan, so use software 328 * scanning instead. First send a nullfunc frame with power save 329 * bit on so that AP will buffer the frames for us while we are not 330 * listening, then send probe requests to each channel and wait for 331 * the responses. After all channels are scanned, tune back to the 332 * original channel and send a nullfunc frame with power save bit 333 * off to trigger the AP to send us all the buffered frames. 334 * 335 * Note that while local->sw_scanning is true everything else but 336 * nullfunc frames and probe requests will be dropped in 337 * ieee80211_tx_h_check_assoc(). 338 */ 339 drv_sw_scan_start(local); 340 341 local->leave_oper_channel_time = 0; 342 local->next_scan_state = SCAN_DECISION; 343 local->scan_channel_idx = 0; 344 345 ieee80211_offchannel_stop_vifs(local, true); 346 347 ieee80211_configure_filter(local); 348 349 /* We need to set power level at maximum rate for scanning. */ 350 ieee80211_hw_config(local, 0); 351 352 ieee80211_queue_delayed_work(&local->hw, 353 &local->scan_work, 0); 354 355 return 0; 356 } 357 358 359 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 360 struct cfg80211_scan_request *req) 361 { 362 struct ieee80211_local *local = sdata->local; 363 int rc; 364 365 lockdep_assert_held(&local->mtx); 366 367 if (local->scan_req) 368 return -EBUSY; 369 370 if (!list_empty(&local->work_list)) { 371 /* wait for the work to finish/time out */ 372 local->scan_req = req; 373 local->scan_sdata = sdata; 374 return 0; 375 } 376 377 if (local->ops->hw_scan) { 378 u8 *ies; 379 380 local->hw_scan_req = kmalloc( 381 sizeof(*local->hw_scan_req) + 382 req->n_channels * sizeof(req->channels[0]) + 383 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 384 req->ie_len, GFP_KERNEL); 385 if (!local->hw_scan_req) 386 return -ENOMEM; 387 388 local->hw_scan_req->ssids = req->ssids; 389 local->hw_scan_req->n_ssids = req->n_ssids; 390 ies = (u8 *)local->hw_scan_req + 391 sizeof(*local->hw_scan_req) + 392 req->n_channels * sizeof(req->channels[0]); 393 local->hw_scan_req->ie = ies; 394 395 local->hw_scan_band = 0; 396 397 /* 398 * After allocating local->hw_scan_req, we must 399 * go through until ieee80211_prep_hw_scan(), so 400 * anything that might be changed here and leave 401 * this function early must not go after this 402 * allocation. 403 */ 404 } 405 406 local->scan_req = req; 407 local->scan_sdata = sdata; 408 409 if (local->ops->hw_scan) 410 __set_bit(SCAN_HW_SCANNING, &local->scanning); 411 else 412 __set_bit(SCAN_SW_SCANNING, &local->scanning); 413 414 ieee80211_recalc_idle(local); 415 416 if (local->ops->hw_scan) { 417 WARN_ON(!ieee80211_prep_hw_scan(local)); 418 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 419 } else 420 rc = ieee80211_start_sw_scan(local); 421 422 if (rc) { 423 kfree(local->hw_scan_req); 424 local->hw_scan_req = NULL; 425 local->scanning = 0; 426 427 ieee80211_recalc_idle(local); 428 429 local->scan_req = NULL; 430 local->scan_sdata = NULL; 431 } 432 433 return rc; 434 } 435 436 static unsigned long 437 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 438 { 439 /* 440 * TODO: channel switching also consumes quite some time, 441 * add that delay as well to get a better estimation 442 */ 443 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 444 return IEEE80211_PASSIVE_CHANNEL_TIME; 445 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 446 } 447 448 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 449 unsigned long *next_delay) 450 { 451 bool associated = false; 452 bool tx_empty = true; 453 bool bad_latency; 454 bool listen_int_exceeded; 455 unsigned long min_beacon_int = 0; 456 struct ieee80211_sub_if_data *sdata; 457 struct ieee80211_channel *next_chan; 458 459 /* 460 * check if at least one STA interface is associated, 461 * check if at least one STA interface has pending tx frames 462 * and grab the lowest used beacon interval 463 */ 464 mutex_lock(&local->iflist_mtx); 465 list_for_each_entry(sdata, &local->interfaces, list) { 466 if (!ieee80211_sdata_running(sdata)) 467 continue; 468 469 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 470 if (sdata->u.mgd.associated) { 471 associated = true; 472 473 if (sdata->vif.bss_conf.beacon_int < 474 min_beacon_int || min_beacon_int == 0) 475 min_beacon_int = 476 sdata->vif.bss_conf.beacon_int; 477 478 if (!qdisc_all_tx_empty(sdata->dev)) { 479 tx_empty = false; 480 break; 481 } 482 } 483 } 484 } 485 mutex_unlock(&local->iflist_mtx); 486 487 next_chan = local->scan_req->channels[local->scan_channel_idx]; 488 489 /* 490 * we're currently scanning a different channel, let's 491 * see if we can scan another channel without interfering 492 * with the current traffic situation. 493 * 494 * Since we don't know if the AP has pending frames for us 495 * we can only check for our tx queues and use the current 496 * pm_qos requirements for rx. Hence, if no tx traffic occurs 497 * at all we will scan as many channels in a row as the pm_qos 498 * latency allows us to. Additionally we also check for the 499 * currently negotiated listen interval to prevent losing 500 * frames unnecessarily. 501 * 502 * Otherwise switch back to the operating channel. 503 */ 504 505 bad_latency = time_after(jiffies + 506 ieee80211_scan_get_channel_time(next_chan), 507 local->leave_oper_channel_time + 508 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 509 510 listen_int_exceeded = time_after(jiffies + 511 ieee80211_scan_get_channel_time(next_chan), 512 local->leave_oper_channel_time + 513 usecs_to_jiffies(min_beacon_int * 1024) * 514 local->hw.conf.listen_interval); 515 516 if (associated && (!tx_empty || bad_latency || listen_int_exceeded)) 517 local->next_scan_state = SCAN_SUSPEND; 518 else 519 local->next_scan_state = SCAN_SET_CHANNEL; 520 521 *next_delay = 0; 522 } 523 524 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 525 unsigned long *next_delay) 526 { 527 int skip; 528 struct ieee80211_channel *chan; 529 530 skip = 0; 531 chan = local->scan_req->channels[local->scan_channel_idx]; 532 533 local->scan_channel = chan; 534 535 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 536 skip = 1; 537 538 /* advance state machine to next channel/band */ 539 local->scan_channel_idx++; 540 541 if (skip) { 542 /* if we skip this channel return to the decision state */ 543 local->next_scan_state = SCAN_DECISION; 544 return; 545 } 546 547 /* 548 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 549 * (which unfortunately doesn't say _why_ step a) is done, 550 * but it waits for the probe delay or until a frame is 551 * received - and the received frame would update the NAV). 552 * For now, we do not support waiting until a frame is 553 * received. 554 * 555 * In any case, it is not necessary for a passive scan. 556 */ 557 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 558 !local->scan_req->n_ssids) { 559 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 560 local->next_scan_state = SCAN_DECISION; 561 return; 562 } 563 564 /* active scan, send probes */ 565 *next_delay = IEEE80211_PROBE_DELAY; 566 local->next_scan_state = SCAN_SEND_PROBE; 567 } 568 569 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 570 unsigned long *next_delay) 571 { 572 int i; 573 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 574 enum ieee80211_band band = local->hw.conf.channel->band; 575 576 for (i = 0; i < local->scan_req->n_ssids; i++) 577 ieee80211_send_probe_req( 578 sdata, NULL, 579 local->scan_req->ssids[i].ssid, 580 local->scan_req->ssids[i].ssid_len, 581 local->scan_req->ie, local->scan_req->ie_len, 582 local->scan_req->rates[band], false, 583 local->scan_req->no_cck); 584 585 /* 586 * After sending probe requests, wait for probe responses 587 * on the channel. 588 */ 589 *next_delay = IEEE80211_CHANNEL_TIME; 590 local->next_scan_state = SCAN_DECISION; 591 } 592 593 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 594 unsigned long *next_delay) 595 { 596 /* switch back to the operating channel */ 597 local->scan_channel = NULL; 598 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 599 600 /* 601 * Re-enable vifs and beaconing. Leave PS 602 * in off-channel state..will put that back 603 * on-channel at the end of scanning. 604 */ 605 ieee80211_offchannel_return(local, false); 606 607 *next_delay = HZ / 5; 608 /* afterwards, resume scan & go to next channel */ 609 local->next_scan_state = SCAN_RESUME; 610 } 611 612 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 613 unsigned long *next_delay) 614 { 615 /* PS already is in off-channel mode */ 616 ieee80211_offchannel_stop_vifs(local, false); 617 618 if (local->ops->flush) { 619 drv_flush(local, false); 620 *next_delay = 0; 621 } else 622 *next_delay = HZ / 10; 623 624 /* remember when we left the operating channel */ 625 local->leave_oper_channel_time = jiffies; 626 627 /* advance to the next channel to be scanned */ 628 local->next_scan_state = SCAN_SET_CHANNEL; 629 } 630 631 void ieee80211_scan_work(struct work_struct *work) 632 { 633 struct ieee80211_local *local = 634 container_of(work, struct ieee80211_local, scan_work.work); 635 struct ieee80211_sub_if_data *sdata; 636 unsigned long next_delay = 0; 637 bool aborted, hw_scan; 638 639 mutex_lock(&local->mtx); 640 641 sdata = local->scan_sdata; 642 643 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 644 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 645 goto out_complete; 646 } 647 648 if (!sdata || !local->scan_req) 649 goto out; 650 651 if (local->scan_req && !local->scanning) { 652 struct cfg80211_scan_request *req = local->scan_req; 653 int rc; 654 655 local->scan_req = NULL; 656 local->scan_sdata = NULL; 657 658 rc = __ieee80211_start_scan(sdata, req); 659 if (rc) { 660 /* need to complete scan in cfg80211 */ 661 local->scan_req = req; 662 aborted = true; 663 goto out_complete; 664 } else 665 goto out; 666 } 667 668 /* 669 * Avoid re-scheduling when the sdata is going away. 670 */ 671 if (!ieee80211_sdata_running(sdata)) { 672 aborted = true; 673 goto out_complete; 674 } 675 676 /* 677 * as long as no delay is required advance immediately 678 * without scheduling a new work 679 */ 680 do { 681 if (!ieee80211_sdata_running(sdata)) { 682 aborted = true; 683 goto out_complete; 684 } 685 686 switch (local->next_scan_state) { 687 case SCAN_DECISION: 688 /* if no more bands/channels left, complete scan */ 689 if (local->scan_channel_idx >= local->scan_req->n_channels) { 690 aborted = false; 691 goto out_complete; 692 } 693 ieee80211_scan_state_decision(local, &next_delay); 694 break; 695 case SCAN_SET_CHANNEL: 696 ieee80211_scan_state_set_channel(local, &next_delay); 697 break; 698 case SCAN_SEND_PROBE: 699 ieee80211_scan_state_send_probe(local, &next_delay); 700 break; 701 case SCAN_SUSPEND: 702 ieee80211_scan_state_suspend(local, &next_delay); 703 break; 704 case SCAN_RESUME: 705 ieee80211_scan_state_resume(local, &next_delay); 706 break; 707 } 708 } while (next_delay == 0); 709 710 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 711 goto out; 712 713 out_complete: 714 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 715 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 716 out: 717 mutex_unlock(&local->mtx); 718 } 719 720 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 721 struct cfg80211_scan_request *req) 722 { 723 int res; 724 725 mutex_lock(&sdata->local->mtx); 726 res = __ieee80211_start_scan(sdata, req); 727 mutex_unlock(&sdata->local->mtx); 728 729 return res; 730 } 731 732 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 733 const u8 *ssid, u8 ssid_len, 734 struct ieee80211_channel *chan) 735 { 736 struct ieee80211_local *local = sdata->local; 737 int ret = -EBUSY; 738 enum ieee80211_band band; 739 740 mutex_lock(&local->mtx); 741 742 /* busy scanning */ 743 if (local->scan_req) 744 goto unlock; 745 746 /* fill internal scan request */ 747 if (!chan) { 748 int i, nchan = 0; 749 750 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 751 if (!local->hw.wiphy->bands[band]) 752 continue; 753 for (i = 0; 754 i < local->hw.wiphy->bands[band]->n_channels; 755 i++) { 756 local->int_scan_req->channels[nchan] = 757 &local->hw.wiphy->bands[band]->channels[i]; 758 nchan++; 759 } 760 } 761 762 local->int_scan_req->n_channels = nchan; 763 } else { 764 local->int_scan_req->channels[0] = chan; 765 local->int_scan_req->n_channels = 1; 766 } 767 768 local->int_scan_req->ssids = &local->scan_ssid; 769 local->int_scan_req->n_ssids = 1; 770 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 771 local->int_scan_req->ssids[0].ssid_len = ssid_len; 772 773 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 774 unlock: 775 mutex_unlock(&local->mtx); 776 return ret; 777 } 778 779 /* 780 * Only call this function when a scan can't be queued -- under RTNL. 781 */ 782 void ieee80211_scan_cancel(struct ieee80211_local *local) 783 { 784 /* 785 * We are canceling software scan, or deferred scan that was not 786 * yet really started (see __ieee80211_start_scan ). 787 * 788 * Regarding hardware scan: 789 * - we can not call __ieee80211_scan_completed() as when 790 * SCAN_HW_SCANNING bit is set this function change 791 * local->hw_scan_req to operate on 5G band, what race with 792 * driver which can use local->hw_scan_req 793 * 794 * - we can not cancel scan_work since driver can schedule it 795 * by ieee80211_scan_completed(..., true) to finish scan 796 * 797 * Hence we only call the cancel_hw_scan() callback, but the low-level 798 * driver is still responsible for calling ieee80211_scan_completed() 799 * after the scan was completed/aborted. 800 */ 801 802 mutex_lock(&local->mtx); 803 if (!local->scan_req) 804 goto out; 805 806 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 807 if (local->ops->cancel_hw_scan) 808 drv_cancel_hw_scan(local, local->scan_sdata); 809 goto out; 810 } 811 812 /* 813 * If the work is currently running, it must be blocked on 814 * the mutex, but we'll set scan_sdata = NULL and it'll 815 * simply exit once it acquires the mutex. 816 */ 817 cancel_delayed_work(&local->scan_work); 818 /* and clean up */ 819 __ieee80211_scan_completed(&local->hw, true, false); 820 out: 821 mutex_unlock(&local->mtx); 822 } 823 824 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 825 struct cfg80211_sched_scan_request *req) 826 { 827 struct ieee80211_local *local = sdata->local; 828 int ret, i; 829 830 mutex_lock(&sdata->local->mtx); 831 832 if (local->sched_scanning) { 833 ret = -EBUSY; 834 goto out; 835 } 836 837 if (!local->ops->sched_scan_start) { 838 ret = -ENOTSUPP; 839 goto out; 840 } 841 842 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 843 local->sched_scan_ies.ie[i] = kzalloc(2 + 844 IEEE80211_MAX_SSID_LEN + 845 local->scan_ies_len + 846 req->ie_len, 847 GFP_KERNEL); 848 if (!local->sched_scan_ies.ie[i]) { 849 ret = -ENOMEM; 850 goto out_free; 851 } 852 853 local->sched_scan_ies.len[i] = 854 ieee80211_build_preq_ies(local, 855 local->sched_scan_ies.ie[i], 856 req->ie, req->ie_len, i, 857 (u32) -1, 0); 858 } 859 860 ret = drv_sched_scan_start(local, sdata, req, 861 &local->sched_scan_ies); 862 if (ret == 0) { 863 local->sched_scanning = true; 864 goto out; 865 } 866 867 out_free: 868 while (i > 0) 869 kfree(local->sched_scan_ies.ie[--i]); 870 out: 871 mutex_unlock(&sdata->local->mtx); 872 return ret; 873 } 874 875 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 876 { 877 struct ieee80211_local *local = sdata->local; 878 int ret = 0, i; 879 880 mutex_lock(&sdata->local->mtx); 881 882 if (!local->ops->sched_scan_stop) { 883 ret = -ENOTSUPP; 884 goto out; 885 } 886 887 if (local->sched_scanning) { 888 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 889 kfree(local->sched_scan_ies.ie[i]); 890 891 drv_sched_scan_stop(local, sdata); 892 local->sched_scanning = false; 893 } 894 out: 895 mutex_unlock(&sdata->local->mtx); 896 897 return ret; 898 } 899 900 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 901 { 902 struct ieee80211_local *local = hw_to_local(hw); 903 904 trace_api_sched_scan_results(local); 905 906 cfg80211_sched_scan_results(hw->wiphy); 907 } 908 EXPORT_SYMBOL(ieee80211_sched_scan_results); 909 910 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 911 { 912 struct ieee80211_local *local = 913 container_of(work, struct ieee80211_local, 914 sched_scan_stopped_work); 915 int i; 916 917 mutex_lock(&local->mtx); 918 919 if (!local->sched_scanning) { 920 mutex_unlock(&local->mtx); 921 return; 922 } 923 924 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 925 kfree(local->sched_scan_ies.ie[i]); 926 927 local->sched_scanning = false; 928 929 mutex_unlock(&local->mtx); 930 931 cfg80211_sched_scan_stopped(local->hw.wiphy); 932 } 933 934 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 935 { 936 struct ieee80211_local *local = hw_to_local(hw); 937 938 trace_api_sched_scan_stopped(local); 939 940 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 941 } 942 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 943