1 /* 2 * Scanning implementation 3 * 4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 5 * Copyright 2004, Instant802 Networks, Inc. 6 * Copyright 2005, Devicescape Software, Inc. 7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/if_arp.h> 16 #include <linux/etherdevice.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/pm_qos.h> 19 #include <net/sch_generic.h> 20 #include <linux/slab.h> 21 #include <linux/export.h> 22 #include <net/mac80211.h> 23 24 #include "ieee80211_i.h" 25 #include "driver-ops.h" 26 #include "mesh.h" 27 28 #define IEEE80211_PROBE_DELAY (HZ / 33) 29 #define IEEE80211_CHANNEL_TIME (HZ / 33) 30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) 31 32 struct ieee80211_bss * 33 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, 34 u8 *ssid, u8 ssid_len) 35 { 36 struct cfg80211_bss *cbss; 37 38 cbss = cfg80211_get_bss(local->hw.wiphy, 39 ieee80211_get_channel(local->hw.wiphy, freq), 40 bssid, ssid, ssid_len, 0, 0); 41 if (!cbss) 42 return NULL; 43 return (void *)cbss->priv; 44 } 45 46 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) 47 { 48 struct ieee80211_bss *bss = (void *)cbss->priv; 49 50 kfree(bss_mesh_id(bss)); 51 kfree(bss_mesh_cfg(bss)); 52 } 53 54 void ieee80211_rx_bss_put(struct ieee80211_local *local, 55 struct ieee80211_bss *bss) 56 { 57 if (!bss) 58 return; 59 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); 60 } 61 62 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 63 { 64 u8 qos_info; 65 66 if (elems->wmm_info && elems->wmm_info_len == 7 67 && elems->wmm_info[5] == 1) 68 qos_info = elems->wmm_info[6]; 69 else if (elems->wmm_param && elems->wmm_param_len == 24 70 && elems->wmm_param[5] == 1) 71 qos_info = elems->wmm_param[6]; 72 else 73 /* no valid wmm information or parameter element found */ 74 return false; 75 76 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 77 } 78 79 struct ieee80211_bss * 80 ieee80211_bss_info_update(struct ieee80211_local *local, 81 struct ieee80211_rx_status *rx_status, 82 struct ieee80211_mgmt *mgmt, 83 size_t len, 84 struct ieee802_11_elems *elems, 85 struct ieee80211_channel *channel, 86 bool beacon) 87 { 88 struct cfg80211_bss *cbss; 89 struct ieee80211_bss *bss; 90 int clen, srlen; 91 s32 signal = 0; 92 93 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 94 signal = rx_status->signal * 100; 95 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 96 signal = (rx_status->signal * 100) / local->hw.max_signal; 97 98 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, 99 mgmt, len, signal, GFP_ATOMIC); 100 101 if (!cbss) 102 return NULL; 103 104 cbss->free_priv = ieee80211_rx_bss_free; 105 bss = (void *)cbss->priv; 106 107 if (elems->parse_error) { 108 if (beacon) 109 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 110 else 111 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 112 } else { 113 if (beacon) 114 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 115 else 116 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 117 } 118 119 /* save the ERP value so that it is available at association time */ 120 if (elems->erp_info && elems->erp_info_len >= 1 && 121 (!elems->parse_error || 122 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 123 bss->erp_value = elems->erp_info[0]; 124 bss->has_erp_value = true; 125 if (!elems->parse_error) 126 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 127 } 128 129 if (elems->tim && (!elems->parse_error || 130 !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) { 131 struct ieee80211_tim_ie *tim_ie = 132 (struct ieee80211_tim_ie *)elems->tim; 133 bss->dtim_period = tim_ie->dtim_period; 134 if (!elems->parse_error) 135 bss->valid_data |= IEEE80211_BSS_VALID_DTIM; 136 } 137 138 /* If the beacon had no TIM IE, or it was invalid, use 1 */ 139 if (beacon && !bss->dtim_period) 140 bss->dtim_period = 1; 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 bss->last_probe_resp = jiffies; 178 179 return bss; 180 } 181 182 ieee80211_rx_result 183 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 184 { 185 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 186 struct ieee80211_mgmt *mgmt; 187 struct ieee80211_bss *bss; 188 u8 *elements; 189 struct ieee80211_channel *channel; 190 size_t baselen; 191 int freq; 192 __le16 fc; 193 bool presp, beacon = false; 194 struct ieee802_11_elems elems; 195 196 if (skb->len < 2) 197 return RX_DROP_UNUSABLE; 198 199 mgmt = (struct ieee80211_mgmt *) skb->data; 200 fc = mgmt->frame_control; 201 202 if (ieee80211_is_ctl(fc)) 203 return RX_CONTINUE; 204 205 if (skb->len < 24) 206 return RX_CONTINUE; 207 208 presp = ieee80211_is_probe_resp(fc); 209 if (presp) { 210 /* ignore ProbeResp to foreign address */ 211 if (compare_ether_addr(mgmt->da, sdata->vif.addr)) 212 return RX_DROP_MONITOR; 213 214 presp = true; 215 elements = mgmt->u.probe_resp.variable; 216 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 217 } else { 218 beacon = ieee80211_is_beacon(fc); 219 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 220 elements = mgmt->u.beacon.variable; 221 } 222 223 if (!presp && !beacon) 224 return RX_CONTINUE; 225 226 if (baselen > skb->len) 227 return RX_DROP_MONITOR; 228 229 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 230 231 if (elems.ds_params && elems.ds_params_len == 1) 232 freq = ieee80211_channel_to_frequency(elems.ds_params[0], 233 rx_status->band); 234 else 235 freq = rx_status->freq; 236 237 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 238 239 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 240 return RX_DROP_MONITOR; 241 242 bss = ieee80211_bss_info_update(sdata->local, rx_status, 243 mgmt, skb->len, &elems, 244 channel, beacon); 245 if (bss) 246 ieee80211_rx_bss_put(sdata->local, bss); 247 248 if (channel == sdata->local->oper_channel) 249 return RX_CONTINUE; 250 251 dev_kfree_skb(skb); 252 return RX_QUEUED; 253 } 254 255 /* return false if no more work */ 256 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 257 { 258 struct cfg80211_scan_request *req = local->scan_req; 259 enum ieee80211_band band; 260 int i, ielen, n_chans; 261 262 do { 263 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 264 return false; 265 266 band = local->hw_scan_band; 267 n_chans = 0; 268 for (i = 0; i < req->n_channels; i++) { 269 if (req->channels[i]->band == band) { 270 local->hw_scan_req->channels[n_chans] = 271 req->channels[i]; 272 n_chans++; 273 } 274 } 275 276 local->hw_scan_band++; 277 } while (!n_chans); 278 279 local->hw_scan_req->n_channels = n_chans; 280 281 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 282 req->ie, req->ie_len, band, 283 req->rates[band], 0); 284 local->hw_scan_req->ie_len = ielen; 285 local->hw_scan_req->no_cck = req->no_cck; 286 287 return true; 288 } 289 290 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 291 bool was_hw_scan) 292 { 293 struct ieee80211_local *local = hw_to_local(hw); 294 295 lockdep_assert_held(&local->mtx); 296 297 /* 298 * It's ok to abort a not-yet-running scan (that 299 * we have one at all will be verified by checking 300 * local->scan_req next), but not to complete it 301 * successfully. 302 */ 303 if (WARN_ON(!local->scanning && !aborted)) 304 aborted = true; 305 306 if (WARN_ON(!local->scan_req)) 307 return; 308 309 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 310 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); 311 if (rc == 0) 312 return; 313 } 314 315 kfree(local->hw_scan_req); 316 local->hw_scan_req = NULL; 317 318 if (local->scan_req != local->int_scan_req) 319 cfg80211_scan_done(local->scan_req, aborted); 320 local->scan_req = NULL; 321 local->scan_sdata = NULL; 322 323 local->scanning = 0; 324 local->scan_channel = NULL; 325 326 /* Set power back to normal operating levels. */ 327 ieee80211_hw_config(local, 0); 328 329 if (!was_hw_scan) { 330 ieee80211_configure_filter(local); 331 drv_sw_scan_complete(local); 332 ieee80211_offchannel_return(local, true); 333 } 334 335 ieee80211_recalc_idle(local); 336 337 ieee80211_mlme_notify_scan_completed(local); 338 ieee80211_ibss_notify_scan_completed(local); 339 ieee80211_mesh_notify_scan_completed(local); 340 ieee80211_queue_work(&local->hw, &local->work_work); 341 } 342 343 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 344 { 345 struct ieee80211_local *local = hw_to_local(hw); 346 347 trace_api_scan_completed(local, aborted); 348 349 set_bit(SCAN_COMPLETED, &local->scanning); 350 if (aborted) 351 set_bit(SCAN_ABORTED, &local->scanning); 352 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 353 } 354 EXPORT_SYMBOL(ieee80211_scan_completed); 355 356 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 357 { 358 /* 359 * Hardware/driver doesn't support hw_scan, so use software 360 * scanning instead. First send a nullfunc frame with power save 361 * bit on so that AP will buffer the frames for us while we are not 362 * listening, then send probe requests to each channel and wait for 363 * the responses. After all channels are scanned, tune back to the 364 * original channel and send a nullfunc frame with power save bit 365 * off to trigger the AP to send us all the buffered frames. 366 * 367 * Note that while local->sw_scanning is true everything else but 368 * nullfunc frames and probe requests will be dropped in 369 * ieee80211_tx_h_check_assoc(). 370 */ 371 drv_sw_scan_start(local); 372 373 local->leave_oper_channel_time = jiffies; 374 local->next_scan_state = SCAN_DECISION; 375 local->scan_channel_idx = 0; 376 377 ieee80211_offchannel_stop_vifs(local, true); 378 379 ieee80211_configure_filter(local); 380 381 /* We need to set power level at maximum rate for scanning. */ 382 ieee80211_hw_config(local, 0); 383 384 ieee80211_queue_delayed_work(&local->hw, 385 &local->scan_work, 0); 386 387 return 0; 388 } 389 390 391 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 392 struct cfg80211_scan_request *req) 393 { 394 struct ieee80211_local *local = sdata->local; 395 int rc; 396 397 lockdep_assert_held(&local->mtx); 398 399 if (local->scan_req) 400 return -EBUSY; 401 402 if (!list_empty(&local->work_list)) { 403 /* wait for the work to finish/time out */ 404 local->scan_req = req; 405 local->scan_sdata = sdata; 406 return 0; 407 } 408 409 if (local->ops->hw_scan) { 410 u8 *ies; 411 412 local->hw_scan_req = kmalloc( 413 sizeof(*local->hw_scan_req) + 414 req->n_channels * sizeof(req->channels[0]) + 415 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 416 req->ie_len, GFP_KERNEL); 417 if (!local->hw_scan_req) 418 return -ENOMEM; 419 420 local->hw_scan_req->ssids = req->ssids; 421 local->hw_scan_req->n_ssids = req->n_ssids; 422 ies = (u8 *)local->hw_scan_req + 423 sizeof(*local->hw_scan_req) + 424 req->n_channels * sizeof(req->channels[0]); 425 local->hw_scan_req->ie = ies; 426 427 local->hw_scan_band = 0; 428 429 /* 430 * After allocating local->hw_scan_req, we must 431 * go through until ieee80211_prep_hw_scan(), so 432 * anything that might be changed here and leave 433 * this function early must not go after this 434 * allocation. 435 */ 436 } 437 438 local->scan_req = req; 439 local->scan_sdata = sdata; 440 441 if (local->ops->hw_scan) 442 __set_bit(SCAN_HW_SCANNING, &local->scanning); 443 else 444 __set_bit(SCAN_SW_SCANNING, &local->scanning); 445 446 ieee80211_recalc_idle(local); 447 448 if (local->ops->hw_scan) { 449 WARN_ON(!ieee80211_prep_hw_scan(local)); 450 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 451 } else 452 rc = ieee80211_start_sw_scan(local); 453 454 if (rc) { 455 kfree(local->hw_scan_req); 456 local->hw_scan_req = NULL; 457 local->scanning = 0; 458 459 ieee80211_recalc_idle(local); 460 461 local->scan_req = NULL; 462 local->scan_sdata = NULL; 463 } 464 465 return rc; 466 } 467 468 static unsigned long 469 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 470 { 471 /* 472 * TODO: channel switching also consumes quite some time, 473 * add that delay as well to get a better estimation 474 */ 475 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 476 return IEEE80211_PASSIVE_CHANNEL_TIME; 477 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 478 } 479 480 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 481 unsigned long *next_delay) 482 { 483 bool associated = false; 484 bool tx_empty = true; 485 bool bad_latency; 486 bool listen_int_exceeded; 487 unsigned long min_beacon_int = 0; 488 struct ieee80211_sub_if_data *sdata; 489 struct ieee80211_channel *next_chan; 490 491 /* 492 * check if at least one STA interface is associated, 493 * check if at least one STA interface has pending tx frames 494 * and grab the lowest used beacon interval 495 */ 496 mutex_lock(&local->iflist_mtx); 497 list_for_each_entry(sdata, &local->interfaces, list) { 498 if (!ieee80211_sdata_running(sdata)) 499 continue; 500 501 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 502 if (sdata->u.mgd.associated) { 503 associated = true; 504 505 if (sdata->vif.bss_conf.beacon_int < 506 min_beacon_int || min_beacon_int == 0) 507 min_beacon_int = 508 sdata->vif.bss_conf.beacon_int; 509 510 if (!qdisc_all_tx_empty(sdata->dev)) { 511 tx_empty = false; 512 break; 513 } 514 } 515 } 516 } 517 mutex_unlock(&local->iflist_mtx); 518 519 next_chan = local->scan_req->channels[local->scan_channel_idx]; 520 521 /* 522 * we're currently scanning a different channel, let's 523 * see if we can scan another channel without interfering 524 * with the current traffic situation. 525 * 526 * Since we don't know if the AP has pending frames for us 527 * we can only check for our tx queues and use the current 528 * pm_qos requirements for rx. Hence, if no tx traffic occurs 529 * at all we will scan as many channels in a row as the pm_qos 530 * latency allows us to. Additionally we also check for the 531 * currently negotiated listen interval to prevent losing 532 * frames unnecessarily. 533 * 534 * Otherwise switch back to the operating channel. 535 */ 536 537 bad_latency = time_after(jiffies + 538 ieee80211_scan_get_channel_time(next_chan), 539 local->leave_oper_channel_time + 540 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 541 542 listen_int_exceeded = time_after(jiffies + 543 ieee80211_scan_get_channel_time(next_chan), 544 local->leave_oper_channel_time + 545 usecs_to_jiffies(min_beacon_int * 1024) * 546 local->hw.conf.listen_interval); 547 548 if (associated && (!tx_empty || bad_latency || listen_int_exceeded)) 549 local->next_scan_state = SCAN_SUSPEND; 550 else 551 local->next_scan_state = SCAN_SET_CHANNEL; 552 553 *next_delay = 0; 554 } 555 556 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 557 unsigned long *next_delay) 558 { 559 int skip; 560 struct ieee80211_channel *chan; 561 562 skip = 0; 563 chan = local->scan_req->channels[local->scan_channel_idx]; 564 565 local->scan_channel = chan; 566 567 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 568 skip = 1; 569 570 /* advance state machine to next channel/band */ 571 local->scan_channel_idx++; 572 573 if (skip) { 574 /* if we skip this channel return to the decision state */ 575 local->next_scan_state = SCAN_DECISION; 576 return; 577 } 578 579 /* 580 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 581 * (which unfortunately doesn't say _why_ step a) is done, 582 * but it waits for the probe delay or until a frame is 583 * received - and the received frame would update the NAV). 584 * For now, we do not support waiting until a frame is 585 * received. 586 * 587 * In any case, it is not necessary for a passive scan. 588 */ 589 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 590 !local->scan_req->n_ssids) { 591 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 592 local->next_scan_state = SCAN_DECISION; 593 return; 594 } 595 596 /* active scan, send probes */ 597 *next_delay = IEEE80211_PROBE_DELAY; 598 local->next_scan_state = SCAN_SEND_PROBE; 599 } 600 601 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 602 unsigned long *next_delay) 603 { 604 int i; 605 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 606 enum ieee80211_band band = local->hw.conf.channel->band; 607 608 for (i = 0; i < local->scan_req->n_ssids; i++) 609 ieee80211_send_probe_req( 610 sdata, NULL, 611 local->scan_req->ssids[i].ssid, 612 local->scan_req->ssids[i].ssid_len, 613 local->scan_req->ie, local->scan_req->ie_len, 614 local->scan_req->rates[band], false, 615 local->scan_req->no_cck); 616 617 /* 618 * After sending probe requests, wait for probe responses 619 * on the channel. 620 */ 621 *next_delay = IEEE80211_CHANNEL_TIME; 622 local->next_scan_state = SCAN_DECISION; 623 } 624 625 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 626 unsigned long *next_delay) 627 { 628 /* switch back to the operating channel */ 629 local->scan_channel = NULL; 630 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 631 632 /* 633 * Re-enable vifs and beaconing. Leave PS 634 * in off-channel state..will put that back 635 * on-channel at the end of scanning. 636 */ 637 ieee80211_offchannel_return(local, false); 638 639 *next_delay = HZ / 5; 640 /* afterwards, resume scan & go to next channel */ 641 local->next_scan_state = SCAN_RESUME; 642 } 643 644 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 645 unsigned long *next_delay) 646 { 647 /* PS already is in off-channel mode */ 648 ieee80211_offchannel_stop_vifs(local, false); 649 650 if (local->ops->flush) { 651 drv_flush(local, false); 652 *next_delay = 0; 653 } else 654 *next_delay = HZ / 10; 655 656 /* remember when we left the operating channel */ 657 local->leave_oper_channel_time = jiffies; 658 659 /* advance to the next channel to be scanned */ 660 local->next_scan_state = SCAN_SET_CHANNEL; 661 } 662 663 void ieee80211_scan_work(struct work_struct *work) 664 { 665 struct ieee80211_local *local = 666 container_of(work, struct ieee80211_local, scan_work.work); 667 struct ieee80211_sub_if_data *sdata; 668 unsigned long next_delay = 0; 669 bool aborted, hw_scan; 670 671 mutex_lock(&local->mtx); 672 673 sdata = local->scan_sdata; 674 675 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 676 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 677 goto out_complete; 678 } 679 680 if (!sdata || !local->scan_req) 681 goto out; 682 683 if (local->scan_req && !local->scanning) { 684 struct cfg80211_scan_request *req = local->scan_req; 685 int rc; 686 687 local->scan_req = NULL; 688 local->scan_sdata = NULL; 689 690 rc = __ieee80211_start_scan(sdata, req); 691 if (rc) { 692 /* need to complete scan in cfg80211 */ 693 local->scan_req = req; 694 aborted = true; 695 goto out_complete; 696 } else 697 goto out; 698 } 699 700 /* 701 * Avoid re-scheduling when the sdata is going away. 702 */ 703 if (!ieee80211_sdata_running(sdata)) { 704 aborted = true; 705 goto out_complete; 706 } 707 708 /* 709 * as long as no delay is required advance immediately 710 * without scheduling a new work 711 */ 712 do { 713 if (!ieee80211_sdata_running(sdata)) { 714 aborted = true; 715 goto out_complete; 716 } 717 718 switch (local->next_scan_state) { 719 case SCAN_DECISION: 720 /* if no more bands/channels left, complete scan */ 721 if (local->scan_channel_idx >= local->scan_req->n_channels) { 722 aborted = false; 723 goto out_complete; 724 } 725 ieee80211_scan_state_decision(local, &next_delay); 726 break; 727 case SCAN_SET_CHANNEL: 728 ieee80211_scan_state_set_channel(local, &next_delay); 729 break; 730 case SCAN_SEND_PROBE: 731 ieee80211_scan_state_send_probe(local, &next_delay); 732 break; 733 case SCAN_SUSPEND: 734 ieee80211_scan_state_suspend(local, &next_delay); 735 break; 736 case SCAN_RESUME: 737 ieee80211_scan_state_resume(local, &next_delay); 738 break; 739 } 740 } while (next_delay == 0); 741 742 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 743 goto out; 744 745 out_complete: 746 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 747 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 748 out: 749 mutex_unlock(&local->mtx); 750 } 751 752 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 753 struct cfg80211_scan_request *req) 754 { 755 int res; 756 757 mutex_lock(&sdata->local->mtx); 758 res = __ieee80211_start_scan(sdata, req); 759 mutex_unlock(&sdata->local->mtx); 760 761 return res; 762 } 763 764 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 765 const u8 *ssid, u8 ssid_len, 766 struct ieee80211_channel *chan) 767 { 768 struct ieee80211_local *local = sdata->local; 769 int ret = -EBUSY; 770 enum ieee80211_band band; 771 772 mutex_lock(&local->mtx); 773 774 /* busy scanning */ 775 if (local->scan_req) 776 goto unlock; 777 778 /* fill internal scan request */ 779 if (!chan) { 780 int i, nchan = 0; 781 782 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 783 if (!local->hw.wiphy->bands[band]) 784 continue; 785 for (i = 0; 786 i < local->hw.wiphy->bands[band]->n_channels; 787 i++) { 788 local->int_scan_req->channels[nchan] = 789 &local->hw.wiphy->bands[band]->channels[i]; 790 nchan++; 791 } 792 } 793 794 local->int_scan_req->n_channels = nchan; 795 } else { 796 local->int_scan_req->channels[0] = chan; 797 local->int_scan_req->n_channels = 1; 798 } 799 800 local->int_scan_req->ssids = &local->scan_ssid; 801 local->int_scan_req->n_ssids = 1; 802 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 803 local->int_scan_req->ssids[0].ssid_len = ssid_len; 804 805 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 806 unlock: 807 mutex_unlock(&local->mtx); 808 return ret; 809 } 810 811 /* 812 * Only call this function when a scan can't be queued -- under RTNL. 813 */ 814 void ieee80211_scan_cancel(struct ieee80211_local *local) 815 { 816 /* 817 * We are canceling software scan, or deferred scan that was not 818 * yet really started (see __ieee80211_start_scan ). 819 * 820 * Regarding hardware scan: 821 * - we can not call __ieee80211_scan_completed() as when 822 * SCAN_HW_SCANNING bit is set this function change 823 * local->hw_scan_req to operate on 5G band, what race with 824 * driver which can use local->hw_scan_req 825 * 826 * - we can not cancel scan_work since driver can schedule it 827 * by ieee80211_scan_completed(..., true) to finish scan 828 * 829 * Hence we only call the cancel_hw_scan() callback, but the low-level 830 * driver is still responsible for calling ieee80211_scan_completed() 831 * after the scan was completed/aborted. 832 */ 833 834 mutex_lock(&local->mtx); 835 if (!local->scan_req) 836 goto out; 837 838 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 839 if (local->ops->cancel_hw_scan) 840 drv_cancel_hw_scan(local, local->scan_sdata); 841 goto out; 842 } 843 844 /* 845 * If the work is currently running, it must be blocked on 846 * the mutex, but we'll set scan_sdata = NULL and it'll 847 * simply exit once it acquires the mutex. 848 */ 849 cancel_delayed_work(&local->scan_work); 850 /* and clean up */ 851 __ieee80211_scan_completed(&local->hw, true, false); 852 out: 853 mutex_unlock(&local->mtx); 854 } 855 856 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 857 struct cfg80211_sched_scan_request *req) 858 { 859 struct ieee80211_local *local = sdata->local; 860 int ret, i; 861 862 mutex_lock(&sdata->local->mtx); 863 864 if (local->sched_scanning) { 865 ret = -EBUSY; 866 goto out; 867 } 868 869 if (!local->ops->sched_scan_start) { 870 ret = -ENOTSUPP; 871 goto out; 872 } 873 874 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 875 local->sched_scan_ies.ie[i] = kzalloc(2 + 876 IEEE80211_MAX_SSID_LEN + 877 local->scan_ies_len + 878 req->ie_len, 879 GFP_KERNEL); 880 if (!local->sched_scan_ies.ie[i]) { 881 ret = -ENOMEM; 882 goto out_free; 883 } 884 885 local->sched_scan_ies.len[i] = 886 ieee80211_build_preq_ies(local, 887 local->sched_scan_ies.ie[i], 888 req->ie, req->ie_len, i, 889 (u32) -1, 0); 890 } 891 892 ret = drv_sched_scan_start(local, sdata, req, 893 &local->sched_scan_ies); 894 if (ret == 0) { 895 local->sched_scanning = true; 896 goto out; 897 } 898 899 out_free: 900 while (i > 0) 901 kfree(local->sched_scan_ies.ie[--i]); 902 out: 903 mutex_unlock(&sdata->local->mtx); 904 return ret; 905 } 906 907 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 908 { 909 struct ieee80211_local *local = sdata->local; 910 int ret = 0, i; 911 912 mutex_lock(&sdata->local->mtx); 913 914 if (!local->ops->sched_scan_stop) { 915 ret = -ENOTSUPP; 916 goto out; 917 } 918 919 if (local->sched_scanning) { 920 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 921 kfree(local->sched_scan_ies.ie[i]); 922 923 drv_sched_scan_stop(local, sdata); 924 local->sched_scanning = false; 925 } 926 out: 927 mutex_unlock(&sdata->local->mtx); 928 929 return ret; 930 } 931 932 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 933 { 934 struct ieee80211_local *local = hw_to_local(hw); 935 936 trace_api_sched_scan_results(local); 937 938 cfg80211_sched_scan_results(hw->wiphy); 939 } 940 EXPORT_SYMBOL(ieee80211_sched_scan_results); 941 942 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 943 { 944 struct ieee80211_local *local = 945 container_of(work, struct ieee80211_local, 946 sched_scan_stopped_work); 947 int i; 948 949 mutex_lock(&local->mtx); 950 951 if (!local->sched_scanning) { 952 mutex_unlock(&local->mtx); 953 return; 954 } 955 956 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 957 kfree(local->sched_scan_ies.ie[i]); 958 959 local->sched_scanning = false; 960 961 mutex_unlock(&local->mtx); 962 963 cfg80211_sched_scan_stopped(local->hw.wiphy); 964 } 965 966 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 967 { 968 struct ieee80211_local *local = hw_to_local(hw); 969 970 trace_api_sched_scan_stopped(local); 971 972 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 973 } 974 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 975