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_params.h> 18 #include <linux/slab.h> 19 #include <net/sch_generic.h> 20 #include <linux/slab.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 = 1; 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 we are on-operating-channel, and this packet is for the 217 * current channel, pass the pkt on up the stack so that 218 * the rest of the stack can make use of it. 219 */ 220 if (ieee80211_cfg_on_oper_channel(sdata->local) 221 && (channel == sdata->local->oper_channel)) 222 return RX_CONTINUE; 223 224 dev_kfree_skb(skb); 225 return RX_QUEUED; 226 } 227 228 /* return false if no more work */ 229 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 230 { 231 struct cfg80211_scan_request *req = local->scan_req; 232 enum ieee80211_band band; 233 int i, ielen, n_chans; 234 235 do { 236 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 237 return false; 238 239 band = local->hw_scan_band; 240 n_chans = 0; 241 for (i = 0; i < req->n_channels; i++) { 242 if (req->channels[i]->band == band) { 243 local->hw_scan_req->channels[n_chans] = 244 req->channels[i]; 245 n_chans++; 246 } 247 } 248 249 local->hw_scan_band++; 250 } while (!n_chans); 251 252 local->hw_scan_req->n_channels = n_chans; 253 254 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 255 req->ie, req->ie_len, band, (u32) -1, 256 0); 257 local->hw_scan_req->ie_len = ielen; 258 259 return true; 260 } 261 262 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 263 bool was_hw_scan) 264 { 265 struct ieee80211_local *local = hw_to_local(hw); 266 bool on_oper_chan; 267 bool enable_beacons = false; 268 269 lockdep_assert_held(&local->mtx); 270 271 /* 272 * It's ok to abort a not-yet-running scan (that 273 * we have one at all will be verified by checking 274 * local->scan_req next), but not to complete it 275 * successfully. 276 */ 277 if (WARN_ON(!local->scanning && !aborted)) 278 aborted = true; 279 280 if (WARN_ON(!local->scan_req)) 281 return; 282 283 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 284 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); 285 if (rc == 0) 286 return; 287 } 288 289 kfree(local->hw_scan_req); 290 local->hw_scan_req = NULL; 291 292 if (local->scan_req != local->int_scan_req) 293 cfg80211_scan_done(local->scan_req, aborted); 294 local->scan_req = NULL; 295 local->scan_sdata = NULL; 296 297 local->scanning = 0; 298 local->scan_channel = NULL; 299 300 on_oper_chan = ieee80211_cfg_on_oper_channel(local); 301 302 if (was_hw_scan || !on_oper_chan) 303 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 304 else 305 /* Set power back to normal operating levels. */ 306 ieee80211_hw_config(local, 0); 307 308 if (!was_hw_scan) { 309 bool on_oper_chan2; 310 ieee80211_configure_filter(local); 311 drv_sw_scan_complete(local); 312 on_oper_chan2 = ieee80211_cfg_on_oper_channel(local); 313 /* We should always be on-channel at this point. */ 314 WARN_ON(!on_oper_chan2); 315 if (on_oper_chan2 && (on_oper_chan != on_oper_chan2)) 316 enable_beacons = true; 317 318 ieee80211_offchannel_return(local, enable_beacons, true); 319 } 320 321 ieee80211_recalc_idle(local); 322 323 ieee80211_mlme_notify_scan_completed(local); 324 ieee80211_ibss_notify_scan_completed(local); 325 ieee80211_mesh_notify_scan_completed(local); 326 ieee80211_queue_work(&local->hw, &local->work_work); 327 } 328 329 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 330 { 331 struct ieee80211_local *local = hw_to_local(hw); 332 333 trace_api_scan_completed(local, aborted); 334 335 set_bit(SCAN_COMPLETED, &local->scanning); 336 if (aborted) 337 set_bit(SCAN_ABORTED, &local->scanning); 338 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 339 } 340 EXPORT_SYMBOL(ieee80211_scan_completed); 341 342 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 343 { 344 /* 345 * Hardware/driver doesn't support hw_scan, so use software 346 * scanning instead. First send a nullfunc frame with power save 347 * bit on so that AP will buffer the frames for us while we are not 348 * listening, then send probe requests to each channel and wait for 349 * the responses. After all channels are scanned, tune back to the 350 * original channel and send a nullfunc frame with power save bit 351 * off to trigger the AP to send us all the buffered frames. 352 * 353 * Note that while local->sw_scanning is true everything else but 354 * nullfunc frames and probe requests will be dropped in 355 * ieee80211_tx_h_check_assoc(). 356 */ 357 drv_sw_scan_start(local); 358 359 local->leave_oper_channel_time = 0; 360 local->next_scan_state = SCAN_DECISION; 361 local->scan_channel_idx = 0; 362 363 /* We always want to use off-channel PS, even if we 364 * are not really leaving oper-channel. Don't 365 * tell the AP though, as long as we are on-channel. 366 */ 367 ieee80211_offchannel_enable_all_ps(local, false); 368 369 ieee80211_configure_filter(local); 370 371 /* We need to set power level at maximum rate for scanning. */ 372 ieee80211_hw_config(local, 0); 373 374 ieee80211_queue_delayed_work(&local->hw, 375 &local->scan_work, 376 IEEE80211_CHANNEL_TIME); 377 378 return 0; 379 } 380 381 382 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 383 struct cfg80211_scan_request *req) 384 { 385 struct ieee80211_local *local = sdata->local; 386 int rc; 387 388 lockdep_assert_held(&local->mtx); 389 390 if (local->scan_req) 391 return -EBUSY; 392 393 if (!list_empty(&local->work_list)) { 394 /* wait for the work to finish/time out */ 395 local->scan_req = req; 396 local->scan_sdata = sdata; 397 return 0; 398 } 399 400 if (local->ops->hw_scan) { 401 u8 *ies; 402 403 local->hw_scan_req = kmalloc( 404 sizeof(*local->hw_scan_req) + 405 req->n_channels * sizeof(req->channels[0]) + 406 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 407 req->ie_len, GFP_KERNEL); 408 if (!local->hw_scan_req) 409 return -ENOMEM; 410 411 local->hw_scan_req->ssids = req->ssids; 412 local->hw_scan_req->n_ssids = req->n_ssids; 413 ies = (u8 *)local->hw_scan_req + 414 sizeof(*local->hw_scan_req) + 415 req->n_channels * sizeof(req->channels[0]); 416 local->hw_scan_req->ie = ies; 417 418 local->hw_scan_band = 0; 419 420 /* 421 * After allocating local->hw_scan_req, we must 422 * go through until ieee80211_prep_hw_scan(), so 423 * anything that might be changed here and leave 424 * this function early must not go after this 425 * allocation. 426 */ 427 } 428 429 local->scan_req = req; 430 local->scan_sdata = sdata; 431 432 if (local->ops->hw_scan) 433 __set_bit(SCAN_HW_SCANNING, &local->scanning); 434 else 435 __set_bit(SCAN_SW_SCANNING, &local->scanning); 436 437 ieee80211_recalc_idle(local); 438 439 if (local->ops->hw_scan) { 440 WARN_ON(!ieee80211_prep_hw_scan(local)); 441 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 442 } else 443 rc = ieee80211_start_sw_scan(local); 444 445 if (rc) { 446 kfree(local->hw_scan_req); 447 local->hw_scan_req = NULL; 448 local->scanning = 0; 449 450 ieee80211_recalc_idle(local); 451 452 local->scan_req = NULL; 453 local->scan_sdata = NULL; 454 } 455 456 return rc; 457 } 458 459 static unsigned long 460 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 461 { 462 /* 463 * TODO: channel switching also consumes quite some time, 464 * add that delay as well to get a better estimation 465 */ 466 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 467 return IEEE80211_PASSIVE_CHANNEL_TIME; 468 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 469 } 470 471 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 472 unsigned long *next_delay) 473 { 474 bool associated = false; 475 bool tx_empty = true; 476 bool bad_latency; 477 bool listen_int_exceeded; 478 unsigned long min_beacon_int = 0; 479 struct ieee80211_sub_if_data *sdata; 480 struct ieee80211_channel *next_chan; 481 482 /* 483 * check if at least one STA interface is associated, 484 * check if at least one STA interface has pending tx frames 485 * and grab the lowest used beacon interval 486 */ 487 mutex_lock(&local->iflist_mtx); 488 list_for_each_entry(sdata, &local->interfaces, list) { 489 if (!ieee80211_sdata_running(sdata)) 490 continue; 491 492 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 493 if (sdata->u.mgd.associated) { 494 associated = true; 495 496 if (sdata->vif.bss_conf.beacon_int < 497 min_beacon_int || min_beacon_int == 0) 498 min_beacon_int = 499 sdata->vif.bss_conf.beacon_int; 500 501 if (!qdisc_all_tx_empty(sdata->dev)) { 502 tx_empty = false; 503 break; 504 } 505 } 506 } 507 } 508 mutex_unlock(&local->iflist_mtx); 509 510 next_chan = local->scan_req->channels[local->scan_channel_idx]; 511 512 if (ieee80211_cfg_on_oper_channel(local)) { 513 /* We're currently on operating channel. */ 514 if (next_chan == local->oper_channel) 515 /* We don't need to move off of operating channel. */ 516 local->next_scan_state = SCAN_SET_CHANNEL; 517 else 518 /* 519 * We do need to leave operating channel, as next 520 * scan is somewhere else. 521 */ 522 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 523 } else { 524 /* 525 * we're currently scanning a different channel, let's 526 * see if we can scan another channel without interfering 527 * with the current traffic situation. 528 * 529 * Since we don't know if the AP has pending frames for us 530 * we can only check for our tx queues and use the current 531 * pm_qos requirements for rx. Hence, if no tx traffic occurs 532 * at all we will scan as many channels in a row as the pm_qos 533 * latency allows us to. Additionally we also check for the 534 * currently negotiated listen interval to prevent losing 535 * frames unnecessarily. 536 * 537 * Otherwise switch back to the operating channel. 538 */ 539 540 bad_latency = time_after(jiffies + 541 ieee80211_scan_get_channel_time(next_chan), 542 local->leave_oper_channel_time + 543 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 544 545 listen_int_exceeded = time_after(jiffies + 546 ieee80211_scan_get_channel_time(next_chan), 547 local->leave_oper_channel_time + 548 usecs_to_jiffies(min_beacon_int * 1024) * 549 local->hw.conf.listen_interval); 550 551 if (associated && ( !tx_empty || bad_latency || 552 listen_int_exceeded)) 553 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 554 else 555 local->next_scan_state = SCAN_SET_CHANNEL; 556 } 557 558 *next_delay = 0; 559 } 560 561 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 562 unsigned long *next_delay) 563 { 564 /* PS will already be in off-channel mode, 565 * we do that once at the beginning of scanning. 566 */ 567 ieee80211_offchannel_stop_vifs(local, false); 568 569 /* 570 * What if the nullfunc frames didn't arrive? 571 */ 572 drv_flush(local, false); 573 if (local->ops->flush) 574 *next_delay = 0; 575 else 576 *next_delay = HZ / 10; 577 578 /* remember when we left the operating channel */ 579 local->leave_oper_channel_time = jiffies; 580 581 /* advance to the next channel to be scanned */ 582 local->next_scan_state = SCAN_SET_CHANNEL; 583 } 584 585 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 586 unsigned long *next_delay) 587 { 588 /* switch back to the operating channel */ 589 local->scan_channel = NULL; 590 if (!ieee80211_cfg_on_oper_channel(local)) 591 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 592 593 /* 594 * Re-enable vifs and beaconing. Leave PS 595 * in off-channel state..will put that back 596 * on-channel at the end of scanning. 597 */ 598 ieee80211_offchannel_return(local, true, false); 599 600 *next_delay = HZ / 5; 601 local->next_scan_state = SCAN_DECISION; 602 } 603 604 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 605 unsigned long *next_delay) 606 { 607 int skip; 608 struct ieee80211_channel *chan; 609 610 skip = 0; 611 chan = local->scan_req->channels[local->scan_channel_idx]; 612 613 local->scan_channel = chan; 614 615 /* Only call hw-config if we really need to change channels. */ 616 if (chan != local->hw.conf.channel) 617 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 618 skip = 1; 619 620 /* advance state machine to next channel/band */ 621 local->scan_channel_idx++; 622 623 if (skip) { 624 /* if we skip this channel return to the decision state */ 625 local->next_scan_state = SCAN_DECISION; 626 return; 627 } 628 629 /* 630 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 631 * (which unfortunately doesn't say _why_ step a) is done, 632 * but it waits for the probe delay or until a frame is 633 * received - and the received frame would update the NAV). 634 * For now, we do not support waiting until a frame is 635 * received. 636 * 637 * In any case, it is not necessary for a passive scan. 638 */ 639 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 640 !local->scan_req->n_ssids) { 641 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 642 local->next_scan_state = SCAN_DECISION; 643 return; 644 } 645 646 /* active scan, send probes */ 647 *next_delay = IEEE80211_PROBE_DELAY; 648 local->next_scan_state = SCAN_SEND_PROBE; 649 } 650 651 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 652 unsigned long *next_delay) 653 { 654 int i; 655 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 656 657 for (i = 0; i < local->scan_req->n_ssids; i++) 658 ieee80211_send_probe_req( 659 sdata, NULL, 660 local->scan_req->ssids[i].ssid, 661 local->scan_req->ssids[i].ssid_len, 662 local->scan_req->ie, local->scan_req->ie_len); 663 664 /* 665 * After sending probe requests, wait for probe responses 666 * on the channel. 667 */ 668 *next_delay = IEEE80211_CHANNEL_TIME; 669 local->next_scan_state = SCAN_DECISION; 670 } 671 672 void ieee80211_scan_work(struct work_struct *work) 673 { 674 struct ieee80211_local *local = 675 container_of(work, struct ieee80211_local, scan_work.work); 676 struct ieee80211_sub_if_data *sdata; 677 unsigned long next_delay = 0; 678 bool aborted, hw_scan; 679 680 mutex_lock(&local->mtx); 681 682 sdata = local->scan_sdata; 683 684 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 685 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 686 goto out_complete; 687 } 688 689 if (!sdata || !local->scan_req) 690 goto out; 691 692 if (local->scan_req && !local->scanning) { 693 struct cfg80211_scan_request *req = local->scan_req; 694 int rc; 695 696 local->scan_req = NULL; 697 local->scan_sdata = NULL; 698 699 rc = __ieee80211_start_scan(sdata, req); 700 if (rc) { 701 /* need to complete scan in cfg80211 */ 702 local->scan_req = req; 703 aborted = true; 704 goto out_complete; 705 } else 706 goto out; 707 } 708 709 /* 710 * Avoid re-scheduling when the sdata is going away. 711 */ 712 if (!ieee80211_sdata_running(sdata)) { 713 aborted = true; 714 goto out_complete; 715 } 716 717 /* 718 * as long as no delay is required advance immediately 719 * without scheduling a new work 720 */ 721 do { 722 switch (local->next_scan_state) { 723 case SCAN_DECISION: 724 /* if no more bands/channels left, complete scan */ 725 if (local->scan_channel_idx >= local->scan_req->n_channels) { 726 aborted = false; 727 goto out_complete; 728 } 729 ieee80211_scan_state_decision(local, &next_delay); 730 break; 731 case SCAN_SET_CHANNEL: 732 ieee80211_scan_state_set_channel(local, &next_delay); 733 break; 734 case SCAN_SEND_PROBE: 735 ieee80211_scan_state_send_probe(local, &next_delay); 736 break; 737 case SCAN_LEAVE_OPER_CHANNEL: 738 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 739 break; 740 case SCAN_ENTER_OPER_CHANNEL: 741 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 742 break; 743 } 744 } while (next_delay == 0); 745 746 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 747 goto out; 748 749 out_complete: 750 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 751 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 752 out: 753 mutex_unlock(&local->mtx); 754 } 755 756 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 757 struct cfg80211_scan_request *req) 758 { 759 int res; 760 761 mutex_lock(&sdata->local->mtx); 762 res = __ieee80211_start_scan(sdata, req); 763 mutex_unlock(&sdata->local->mtx); 764 765 return res; 766 } 767 768 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 769 const u8 *ssid, u8 ssid_len, 770 struct ieee80211_channel *chan) 771 { 772 struct ieee80211_local *local = sdata->local; 773 int ret = -EBUSY; 774 enum ieee80211_band band; 775 776 mutex_lock(&local->mtx); 777 778 /* busy scanning */ 779 if (local->scan_req) 780 goto unlock; 781 782 /* fill internal scan request */ 783 if (!chan) { 784 int i, nchan = 0; 785 786 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 787 if (!local->hw.wiphy->bands[band]) 788 continue; 789 for (i = 0; 790 i < local->hw.wiphy->bands[band]->n_channels; 791 i++) { 792 local->int_scan_req->channels[nchan] = 793 &local->hw.wiphy->bands[band]->channels[i]; 794 nchan++; 795 } 796 } 797 798 local->int_scan_req->n_channels = nchan; 799 } else { 800 local->int_scan_req->channels[0] = chan; 801 local->int_scan_req->n_channels = 1; 802 } 803 804 local->int_scan_req->ssids = &local->scan_ssid; 805 local->int_scan_req->n_ssids = 1; 806 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 807 local->int_scan_req->ssids[0].ssid_len = ssid_len; 808 809 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 810 unlock: 811 mutex_unlock(&local->mtx); 812 return ret; 813 } 814 815 /* 816 * Only call this function when a scan can't be queued -- under RTNL. 817 */ 818 void ieee80211_scan_cancel(struct ieee80211_local *local) 819 { 820 bool abortscan; 821 822 /* 823 * We are only canceling software scan, or deferred scan that was not 824 * yet really started (see __ieee80211_start_scan ). 825 * 826 * Regarding hardware scan: 827 * - we can not call __ieee80211_scan_completed() as when 828 * SCAN_HW_SCANNING bit is set this function change 829 * local->hw_scan_req to operate on 5G band, what race with 830 * driver which can use local->hw_scan_req 831 * 832 * - we can not cancel scan_work since driver can schedule it 833 * by ieee80211_scan_completed(..., true) to finish scan 834 * 835 * Hence low lever driver is responsible for canceling HW scan. 836 */ 837 838 mutex_lock(&local->mtx); 839 abortscan = local->scan_req && !test_bit(SCAN_HW_SCANNING, &local->scanning); 840 if (abortscan) { 841 /* 842 * The scan is canceled, but stop work from being pending. 843 * 844 * If the work is currently running, it must be blocked on 845 * the mutex, but we'll set scan_sdata = NULL and it'll 846 * simply exit once it acquires the mutex. 847 */ 848 cancel_delayed_work(&local->scan_work); 849 /* and clean up */ 850 __ieee80211_scan_completed(&local->hw, true, false); 851 } 852 mutex_unlock(&local->mtx); 853 } 854 855 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 856 struct cfg80211_sched_scan_request *req) 857 { 858 struct ieee80211_local *local = sdata->local; 859 int ret, i; 860 861 mutex_lock(&sdata->local->mtx); 862 863 if (local->sched_scanning) { 864 ret = -EBUSY; 865 goto out; 866 } 867 868 if (!local->ops->sched_scan_start) { 869 ret = -ENOTSUPP; 870 goto out; 871 } 872 873 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 874 local->sched_scan_ies.ie[i] = kzalloc(2 + 875 IEEE80211_MAX_SSID_LEN + 876 local->scan_ies_len, 877 GFP_KERNEL); 878 if (!local->sched_scan_ies.ie[i]) { 879 ret = -ENOMEM; 880 goto out_free; 881 } 882 883 local->sched_scan_ies.len[i] = 884 ieee80211_build_preq_ies(local, 885 local->sched_scan_ies.ie[i], 886 req->ie, req->ie_len, i, 887 (u32) -1, 0); 888 } 889 890 ret = drv_sched_scan_start(local, sdata, req, 891 &local->sched_scan_ies); 892 if (ret == 0) { 893 local->sched_scanning = true; 894 goto out; 895 } 896 897 out_free: 898 while (i > 0) 899 kfree(local->sched_scan_ies.ie[--i]); 900 out: 901 mutex_unlock(&sdata->local->mtx); 902 return ret; 903 } 904 905 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 906 { 907 struct ieee80211_local *local = sdata->local; 908 int ret = 0, i; 909 910 mutex_lock(&sdata->local->mtx); 911 912 if (!local->ops->sched_scan_stop) { 913 ret = -ENOTSUPP; 914 goto out; 915 } 916 917 if (local->sched_scanning) { 918 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 919 kfree(local->sched_scan_ies.ie[i]); 920 921 drv_sched_scan_stop(local, sdata); 922 local->sched_scanning = false; 923 } 924 out: 925 mutex_unlock(&sdata->local->mtx); 926 927 return ret; 928 } 929 930 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 931 { 932 struct ieee80211_local *local = hw_to_local(hw); 933 934 trace_api_sched_scan_results(local); 935 936 cfg80211_sched_scan_results(hw->wiphy); 937 } 938 EXPORT_SYMBOL(ieee80211_sched_scan_results); 939 940 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 941 { 942 struct ieee80211_local *local = 943 container_of(work, struct ieee80211_local, 944 sched_scan_stopped_work); 945 int i; 946 947 mutex_lock(&local->mtx); 948 949 if (!local->sched_scanning) { 950 mutex_unlock(&local->mtx); 951 return; 952 } 953 954 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 955 kfree(local->sched_scan_ies.ie[i]); 956 957 local->sched_scanning = false; 958 959 mutex_unlock(&local->mtx); 960 961 cfg80211_sched_scan_stopped(local->hw.wiphy); 962 } 963 964 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 965 { 966 struct ieee80211_local *local = hw_to_local(hw); 967 968 trace_api_sched_scan_stopped(local); 969 970 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 971 } 972 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 973