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 = 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, 256 req->rates[band], 0); 257 local->hw_scan_req->ie_len = ielen; 258 local->hw_scan_req->no_cck = req->no_cck; 259 260 return true; 261 } 262 263 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 264 bool was_hw_scan) 265 { 266 struct ieee80211_local *local = hw_to_local(hw); 267 bool on_oper_chan; 268 bool enable_beacons = false; 269 270 lockdep_assert_held(&local->mtx); 271 272 /* 273 * It's ok to abort a not-yet-running scan (that 274 * we have one at all will be verified by checking 275 * local->scan_req next), but not to complete it 276 * successfully. 277 */ 278 if (WARN_ON(!local->scanning && !aborted)) 279 aborted = true; 280 281 if (WARN_ON(!local->scan_req)) 282 return; 283 284 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 285 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); 286 if (rc == 0) 287 return; 288 } 289 290 kfree(local->hw_scan_req); 291 local->hw_scan_req = NULL; 292 293 if (local->scan_req != local->int_scan_req) 294 cfg80211_scan_done(local->scan_req, aborted); 295 local->scan_req = NULL; 296 local->scan_sdata = NULL; 297 298 local->scanning = 0; 299 local->scan_channel = NULL; 300 301 on_oper_chan = ieee80211_cfg_on_oper_channel(local); 302 303 if (was_hw_scan || !on_oper_chan) 304 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 305 else 306 /* Set power back to normal operating levels. */ 307 ieee80211_hw_config(local, 0); 308 309 if (!was_hw_scan) { 310 bool on_oper_chan2; 311 ieee80211_configure_filter(local); 312 drv_sw_scan_complete(local); 313 on_oper_chan2 = ieee80211_cfg_on_oper_channel(local); 314 /* We should always be on-channel at this point. */ 315 WARN_ON(!on_oper_chan2); 316 if (on_oper_chan2 && (on_oper_chan != on_oper_chan2)) 317 enable_beacons = true; 318 319 ieee80211_offchannel_return(local, enable_beacons, true); 320 } 321 322 ieee80211_recalc_idle(local); 323 324 ieee80211_mlme_notify_scan_completed(local); 325 ieee80211_ibss_notify_scan_completed(local); 326 ieee80211_mesh_notify_scan_completed(local); 327 ieee80211_queue_work(&local->hw, &local->work_work); 328 } 329 330 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 331 { 332 struct ieee80211_local *local = hw_to_local(hw); 333 334 trace_api_scan_completed(local, aborted); 335 336 set_bit(SCAN_COMPLETED, &local->scanning); 337 if (aborted) 338 set_bit(SCAN_ABORTED, &local->scanning); 339 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); 340 } 341 EXPORT_SYMBOL(ieee80211_scan_completed); 342 343 static int ieee80211_start_sw_scan(struct ieee80211_local *local) 344 { 345 /* 346 * Hardware/driver doesn't support hw_scan, so use software 347 * scanning instead. First send a nullfunc frame with power save 348 * bit on so that AP will buffer the frames for us while we are not 349 * listening, then send probe requests to each channel and wait for 350 * the responses. After all channels are scanned, tune back to the 351 * original channel and send a nullfunc frame with power save bit 352 * off to trigger the AP to send us all the buffered frames. 353 * 354 * Note that while local->sw_scanning is true everything else but 355 * nullfunc frames and probe requests will be dropped in 356 * ieee80211_tx_h_check_assoc(). 357 */ 358 drv_sw_scan_start(local); 359 360 local->leave_oper_channel_time = 0; 361 local->next_scan_state = SCAN_DECISION; 362 local->scan_channel_idx = 0; 363 364 /* We always want to use off-channel PS, even if we 365 * are not really leaving oper-channel. Don't 366 * tell the AP though, as long as we are on-channel. 367 */ 368 ieee80211_offchannel_enable_all_ps(local, false); 369 370 ieee80211_configure_filter(local); 371 372 /* We need to set power level at maximum rate for scanning. */ 373 ieee80211_hw_config(local, 0); 374 375 ieee80211_queue_delayed_work(&local->hw, 376 &local->scan_work, 377 IEEE80211_CHANNEL_TIME); 378 379 return 0; 380 } 381 382 383 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 384 struct cfg80211_scan_request *req) 385 { 386 struct ieee80211_local *local = sdata->local; 387 int rc; 388 389 lockdep_assert_held(&local->mtx); 390 391 if (local->scan_req) 392 return -EBUSY; 393 394 if (!list_empty(&local->work_list)) { 395 /* wait for the work to finish/time out */ 396 local->scan_req = req; 397 local->scan_sdata = sdata; 398 return 0; 399 } 400 401 if (local->ops->hw_scan) { 402 u8 *ies; 403 404 local->hw_scan_req = kmalloc( 405 sizeof(*local->hw_scan_req) + 406 req->n_channels * sizeof(req->channels[0]) + 407 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 408 req->ie_len, GFP_KERNEL); 409 if (!local->hw_scan_req) 410 return -ENOMEM; 411 412 local->hw_scan_req->ssids = req->ssids; 413 local->hw_scan_req->n_ssids = req->n_ssids; 414 ies = (u8 *)local->hw_scan_req + 415 sizeof(*local->hw_scan_req) + 416 req->n_channels * sizeof(req->channels[0]); 417 local->hw_scan_req->ie = ies; 418 419 local->hw_scan_band = 0; 420 421 /* 422 * After allocating local->hw_scan_req, we must 423 * go through until ieee80211_prep_hw_scan(), so 424 * anything that might be changed here and leave 425 * this function early must not go after this 426 * allocation. 427 */ 428 } 429 430 local->scan_req = req; 431 local->scan_sdata = sdata; 432 433 if (local->ops->hw_scan) 434 __set_bit(SCAN_HW_SCANNING, &local->scanning); 435 else 436 __set_bit(SCAN_SW_SCANNING, &local->scanning); 437 438 ieee80211_recalc_idle(local); 439 440 if (local->ops->hw_scan) { 441 WARN_ON(!ieee80211_prep_hw_scan(local)); 442 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 443 } else 444 rc = ieee80211_start_sw_scan(local); 445 446 if (rc) { 447 kfree(local->hw_scan_req); 448 local->hw_scan_req = NULL; 449 local->scanning = 0; 450 451 ieee80211_recalc_idle(local); 452 453 local->scan_req = NULL; 454 local->scan_sdata = NULL; 455 } 456 457 return rc; 458 } 459 460 static unsigned long 461 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 462 { 463 /* 464 * TODO: channel switching also consumes quite some time, 465 * add that delay as well to get a better estimation 466 */ 467 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 468 return IEEE80211_PASSIVE_CHANNEL_TIME; 469 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 470 } 471 472 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 473 unsigned long *next_delay) 474 { 475 bool associated = false; 476 bool tx_empty = true; 477 bool bad_latency; 478 bool listen_int_exceeded; 479 unsigned long min_beacon_int = 0; 480 struct ieee80211_sub_if_data *sdata; 481 struct ieee80211_channel *next_chan; 482 483 /* 484 * check if at least one STA interface is associated, 485 * check if at least one STA interface has pending tx frames 486 * and grab the lowest used beacon interval 487 */ 488 mutex_lock(&local->iflist_mtx); 489 list_for_each_entry(sdata, &local->interfaces, list) { 490 if (!ieee80211_sdata_running(sdata)) 491 continue; 492 493 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 494 if (sdata->u.mgd.associated) { 495 associated = true; 496 497 if (sdata->vif.bss_conf.beacon_int < 498 min_beacon_int || min_beacon_int == 0) 499 min_beacon_int = 500 sdata->vif.bss_conf.beacon_int; 501 502 if (!qdisc_all_tx_empty(sdata->dev)) { 503 tx_empty = false; 504 break; 505 } 506 } 507 } 508 } 509 mutex_unlock(&local->iflist_mtx); 510 511 next_chan = local->scan_req->channels[local->scan_channel_idx]; 512 513 if (ieee80211_cfg_on_oper_channel(local)) { 514 /* We're currently on operating channel. */ 515 if (next_chan == local->oper_channel) 516 /* We don't need to move off of operating channel. */ 517 local->next_scan_state = SCAN_SET_CHANNEL; 518 else 519 /* 520 * We do need to leave operating channel, as next 521 * scan is somewhere else. 522 */ 523 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; 524 } else { 525 /* 526 * we're currently scanning a different channel, let's 527 * see if we can scan another channel without interfering 528 * with the current traffic situation. 529 * 530 * Since we don't know if the AP has pending frames for us 531 * we can only check for our tx queues and use the current 532 * pm_qos requirements for rx. Hence, if no tx traffic occurs 533 * at all we will scan as many channels in a row as the pm_qos 534 * latency allows us to. Additionally we also check for the 535 * currently negotiated listen interval to prevent losing 536 * frames unnecessarily. 537 * 538 * Otherwise switch back to the operating channel. 539 */ 540 541 bad_latency = time_after(jiffies + 542 ieee80211_scan_get_channel_time(next_chan), 543 local->leave_oper_channel_time + 544 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 545 546 listen_int_exceeded = time_after(jiffies + 547 ieee80211_scan_get_channel_time(next_chan), 548 local->leave_oper_channel_time + 549 usecs_to_jiffies(min_beacon_int * 1024) * 550 local->hw.conf.listen_interval); 551 552 if (associated && ( !tx_empty || bad_latency || 553 listen_int_exceeded)) 554 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; 555 else 556 local->next_scan_state = SCAN_SET_CHANNEL; 557 } 558 559 *next_delay = 0; 560 } 561 562 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, 563 unsigned long *next_delay) 564 { 565 /* PS will already be in off-channel mode, 566 * we do that once at the beginning of scanning. 567 */ 568 ieee80211_offchannel_stop_vifs(local, false); 569 570 /* 571 * What if the nullfunc frames didn't arrive? 572 */ 573 drv_flush(local, false); 574 if (local->ops->flush) 575 *next_delay = 0; 576 else 577 *next_delay = HZ / 10; 578 579 /* remember when we left the operating channel */ 580 local->leave_oper_channel_time = jiffies; 581 582 /* advance to the next channel to be scanned */ 583 local->next_scan_state = SCAN_SET_CHANNEL; 584 } 585 586 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, 587 unsigned long *next_delay) 588 { 589 /* switch back to the operating channel */ 590 local->scan_channel = NULL; 591 if (!ieee80211_cfg_on_oper_channel(local)) 592 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 593 594 /* 595 * Re-enable vifs and beaconing. Leave PS 596 * in off-channel state..will put that back 597 * on-channel at the end of scanning. 598 */ 599 ieee80211_offchannel_return(local, true, false); 600 601 *next_delay = HZ / 5; 602 local->next_scan_state = SCAN_DECISION; 603 } 604 605 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 606 unsigned long *next_delay) 607 { 608 int skip; 609 struct ieee80211_channel *chan; 610 611 skip = 0; 612 chan = local->scan_req->channels[local->scan_channel_idx]; 613 614 local->scan_channel = chan; 615 616 /* Only call hw-config if we really need to change channels. */ 617 if (chan != local->hw.conf.channel) 618 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 619 skip = 1; 620 621 /* advance state machine to next channel/band */ 622 local->scan_channel_idx++; 623 624 if (skip) { 625 /* if we skip this channel return to the decision state */ 626 local->next_scan_state = SCAN_DECISION; 627 return; 628 } 629 630 /* 631 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 632 * (which unfortunately doesn't say _why_ step a) is done, 633 * but it waits for the probe delay or until a frame is 634 * received - and the received frame would update the NAV). 635 * For now, we do not support waiting until a frame is 636 * received. 637 * 638 * In any case, it is not necessary for a passive scan. 639 */ 640 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 641 !local->scan_req->n_ssids) { 642 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 643 local->next_scan_state = SCAN_DECISION; 644 return; 645 } 646 647 /* active scan, send probes */ 648 *next_delay = IEEE80211_PROBE_DELAY; 649 local->next_scan_state = SCAN_SEND_PROBE; 650 } 651 652 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 653 unsigned long *next_delay) 654 { 655 int i; 656 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 657 enum ieee80211_band band = local->hw.conf.channel->band; 658 659 for (i = 0; i < local->scan_req->n_ssids; i++) 660 ieee80211_send_probe_req( 661 sdata, NULL, 662 local->scan_req->ssids[i].ssid, 663 local->scan_req->ssids[i].ssid_len, 664 local->scan_req->ie, local->scan_req->ie_len, 665 local->scan_req->rates[band], false, 666 local->scan_req->no_cck); 667 668 /* 669 * After sending probe requests, wait for probe responses 670 * on the channel. 671 */ 672 *next_delay = IEEE80211_CHANNEL_TIME; 673 local->next_scan_state = SCAN_DECISION; 674 } 675 676 void ieee80211_scan_work(struct work_struct *work) 677 { 678 struct ieee80211_local *local = 679 container_of(work, struct ieee80211_local, scan_work.work); 680 struct ieee80211_sub_if_data *sdata; 681 unsigned long next_delay = 0; 682 bool aborted, hw_scan; 683 684 mutex_lock(&local->mtx); 685 686 sdata = local->scan_sdata; 687 688 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 689 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 690 goto out_complete; 691 } 692 693 if (!sdata || !local->scan_req) 694 goto out; 695 696 if (local->scan_req && !local->scanning) { 697 struct cfg80211_scan_request *req = local->scan_req; 698 int rc; 699 700 local->scan_req = NULL; 701 local->scan_sdata = NULL; 702 703 rc = __ieee80211_start_scan(sdata, req); 704 if (rc) { 705 /* need to complete scan in cfg80211 */ 706 local->scan_req = req; 707 aborted = true; 708 goto out_complete; 709 } else 710 goto out; 711 } 712 713 /* 714 * Avoid re-scheduling when the sdata is going away. 715 */ 716 if (!ieee80211_sdata_running(sdata)) { 717 aborted = true; 718 goto out_complete; 719 } 720 721 /* 722 * as long as no delay is required advance immediately 723 * without scheduling a new work 724 */ 725 do { 726 if (!ieee80211_sdata_running(sdata)) { 727 aborted = true; 728 goto out_complete; 729 } 730 731 switch (local->next_scan_state) { 732 case SCAN_DECISION: 733 /* if no more bands/channels left, complete scan */ 734 if (local->scan_channel_idx >= local->scan_req->n_channels) { 735 aborted = false; 736 goto out_complete; 737 } 738 ieee80211_scan_state_decision(local, &next_delay); 739 break; 740 case SCAN_SET_CHANNEL: 741 ieee80211_scan_state_set_channel(local, &next_delay); 742 break; 743 case SCAN_SEND_PROBE: 744 ieee80211_scan_state_send_probe(local, &next_delay); 745 break; 746 case SCAN_LEAVE_OPER_CHANNEL: 747 ieee80211_scan_state_leave_oper_channel(local, &next_delay); 748 break; 749 case SCAN_ENTER_OPER_CHANNEL: 750 ieee80211_scan_state_enter_oper_channel(local, &next_delay); 751 break; 752 } 753 } while (next_delay == 0); 754 755 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 756 goto out; 757 758 out_complete: 759 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 760 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 761 out: 762 mutex_unlock(&local->mtx); 763 } 764 765 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 766 struct cfg80211_scan_request *req) 767 { 768 int res; 769 770 mutex_lock(&sdata->local->mtx); 771 res = __ieee80211_start_scan(sdata, req); 772 mutex_unlock(&sdata->local->mtx); 773 774 return res; 775 } 776 777 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 778 const u8 *ssid, u8 ssid_len, 779 struct ieee80211_channel *chan) 780 { 781 struct ieee80211_local *local = sdata->local; 782 int ret = -EBUSY; 783 enum ieee80211_band band; 784 785 mutex_lock(&local->mtx); 786 787 /* busy scanning */ 788 if (local->scan_req) 789 goto unlock; 790 791 /* fill internal scan request */ 792 if (!chan) { 793 int i, nchan = 0; 794 795 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 796 if (!local->hw.wiphy->bands[band]) 797 continue; 798 for (i = 0; 799 i < local->hw.wiphy->bands[band]->n_channels; 800 i++) { 801 local->int_scan_req->channels[nchan] = 802 &local->hw.wiphy->bands[band]->channels[i]; 803 nchan++; 804 } 805 } 806 807 local->int_scan_req->n_channels = nchan; 808 } else { 809 local->int_scan_req->channels[0] = chan; 810 local->int_scan_req->n_channels = 1; 811 } 812 813 local->int_scan_req->ssids = &local->scan_ssid; 814 local->int_scan_req->n_ssids = 1; 815 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 816 local->int_scan_req->ssids[0].ssid_len = ssid_len; 817 818 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 819 unlock: 820 mutex_unlock(&local->mtx); 821 return ret; 822 } 823 824 /* 825 * Only call this function when a scan can't be queued -- under RTNL. 826 */ 827 void ieee80211_scan_cancel(struct ieee80211_local *local) 828 { 829 /* 830 * We are canceling software scan, or deferred scan that was not 831 * yet really started (see __ieee80211_start_scan ). 832 * 833 * Regarding hardware scan: 834 * - we can not call __ieee80211_scan_completed() as when 835 * SCAN_HW_SCANNING bit is set this function change 836 * local->hw_scan_req to operate on 5G band, what race with 837 * driver which can use local->hw_scan_req 838 * 839 * - we can not cancel scan_work since driver can schedule it 840 * by ieee80211_scan_completed(..., true) to finish scan 841 * 842 * Hence we only call the cancel_hw_scan() callback, but the low-level 843 * driver is still responsible for calling ieee80211_scan_completed() 844 * after the scan was completed/aborted. 845 */ 846 847 mutex_lock(&local->mtx); 848 if (!local->scan_req) 849 goto out; 850 851 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 852 if (local->ops->cancel_hw_scan) 853 drv_cancel_hw_scan(local, local->scan_sdata); 854 goto out; 855 } 856 857 /* 858 * If the work is currently running, it must be blocked on 859 * the mutex, but we'll set scan_sdata = NULL and it'll 860 * simply exit once it acquires the mutex. 861 */ 862 cancel_delayed_work(&local->scan_work); 863 /* and clean up */ 864 __ieee80211_scan_completed(&local->hw, true, false); 865 out: 866 mutex_unlock(&local->mtx); 867 } 868 869 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 870 struct cfg80211_sched_scan_request *req) 871 { 872 struct ieee80211_local *local = sdata->local; 873 int ret, i; 874 875 mutex_lock(&sdata->local->mtx); 876 877 if (local->sched_scanning) { 878 ret = -EBUSY; 879 goto out; 880 } 881 882 if (!local->ops->sched_scan_start) { 883 ret = -ENOTSUPP; 884 goto out; 885 } 886 887 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 888 local->sched_scan_ies.ie[i] = kzalloc(2 + 889 IEEE80211_MAX_SSID_LEN + 890 local->scan_ies_len + 891 req->ie_len, 892 GFP_KERNEL); 893 if (!local->sched_scan_ies.ie[i]) { 894 ret = -ENOMEM; 895 goto out_free; 896 } 897 898 local->sched_scan_ies.len[i] = 899 ieee80211_build_preq_ies(local, 900 local->sched_scan_ies.ie[i], 901 req->ie, req->ie_len, i, 902 (u32) -1, 0); 903 } 904 905 ret = drv_sched_scan_start(local, sdata, req, 906 &local->sched_scan_ies); 907 if (ret == 0) { 908 local->sched_scanning = true; 909 goto out; 910 } 911 912 out_free: 913 while (i > 0) 914 kfree(local->sched_scan_ies.ie[--i]); 915 out: 916 mutex_unlock(&sdata->local->mtx); 917 return ret; 918 } 919 920 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 921 { 922 struct ieee80211_local *local = sdata->local; 923 int ret = 0, i; 924 925 mutex_lock(&sdata->local->mtx); 926 927 if (!local->ops->sched_scan_stop) { 928 ret = -ENOTSUPP; 929 goto out; 930 } 931 932 if (local->sched_scanning) { 933 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 934 kfree(local->sched_scan_ies.ie[i]); 935 936 drv_sched_scan_stop(local, sdata); 937 local->sched_scanning = false; 938 } 939 out: 940 mutex_unlock(&sdata->local->mtx); 941 942 return ret; 943 } 944 945 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 946 { 947 struct ieee80211_local *local = hw_to_local(hw); 948 949 trace_api_sched_scan_results(local); 950 951 cfg80211_sched_scan_results(hw->wiphy); 952 } 953 EXPORT_SYMBOL(ieee80211_sched_scan_results); 954 955 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 956 { 957 struct ieee80211_local *local = 958 container_of(work, struct ieee80211_local, 959 sched_scan_stopped_work); 960 int i; 961 962 mutex_lock(&local->mtx); 963 964 if (!local->sched_scanning) { 965 mutex_unlock(&local->mtx); 966 return; 967 } 968 969 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 970 kfree(local->sched_scan_ies.ie[i]); 971 972 local->sched_scanning = false; 973 974 mutex_unlock(&local->mtx); 975 976 cfg80211_sched_scan_stopped(local->hw.wiphy); 977 } 978 979 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 980 { 981 struct ieee80211_local *local = hw_to_local(hw); 982 983 trace_api_sched_scan_stopped(local); 984 985 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 986 } 987 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 988