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 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) 33 { 34 struct ieee80211_bss *bss = (void *)cbss->priv; 35 36 kfree(bss_mesh_id(bss)); 37 kfree(bss_mesh_cfg(bss)); 38 } 39 40 void ieee80211_rx_bss_put(struct ieee80211_local *local, 41 struct ieee80211_bss *bss) 42 { 43 if (!bss) 44 return; 45 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); 46 } 47 48 static bool is_uapsd_supported(struct ieee802_11_elems *elems) 49 { 50 u8 qos_info; 51 52 if (elems->wmm_info && elems->wmm_info_len == 7 53 && elems->wmm_info[5] == 1) 54 qos_info = elems->wmm_info[6]; 55 else if (elems->wmm_param && elems->wmm_param_len == 24 56 && elems->wmm_param[5] == 1) 57 qos_info = elems->wmm_param[6]; 58 else 59 /* no valid wmm information or parameter element found */ 60 return false; 61 62 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; 63 } 64 65 struct ieee80211_bss * 66 ieee80211_bss_info_update(struct ieee80211_local *local, 67 struct ieee80211_rx_status *rx_status, 68 struct ieee80211_mgmt *mgmt, 69 size_t len, 70 struct ieee802_11_elems *elems, 71 struct ieee80211_channel *channel, 72 bool beacon) 73 { 74 struct cfg80211_bss *cbss; 75 struct ieee80211_bss *bss; 76 int clen, srlen; 77 s32 signal = 0; 78 79 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) 80 signal = rx_status->signal * 100; 81 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) 82 signal = (rx_status->signal * 100) / local->hw.max_signal; 83 84 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, 85 mgmt, len, signal, GFP_ATOMIC); 86 87 if (!cbss) 88 return NULL; 89 90 cbss->free_priv = ieee80211_rx_bss_free; 91 bss = (void *)cbss->priv; 92 93 if (elems->parse_error) { 94 if (beacon) 95 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; 96 else 97 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; 98 } else { 99 if (beacon) 100 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; 101 else 102 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; 103 } 104 105 /* save the ERP value so that it is available at association time */ 106 if (elems->erp_info && elems->erp_info_len >= 1 && 107 (!elems->parse_error || 108 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { 109 bss->erp_value = elems->erp_info[0]; 110 bss->has_erp_value = true; 111 if (!elems->parse_error) 112 bss->valid_data |= IEEE80211_BSS_VALID_ERP; 113 } 114 115 if (elems->tim && (!elems->parse_error || 116 !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) { 117 struct ieee80211_tim_ie *tim_ie = 118 (struct ieee80211_tim_ie *)elems->tim; 119 bss->dtim_period = tim_ie->dtim_period; 120 if (!elems->parse_error) 121 bss->valid_data |= IEEE80211_BSS_VALID_DTIM; 122 } 123 124 /* If the beacon had no TIM IE, or it was invalid, use 1 */ 125 if (beacon && !bss->dtim_period) 126 bss->dtim_period = 1; 127 128 /* replace old supported rates if we get new values */ 129 if (!elems->parse_error || 130 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { 131 srlen = 0; 132 if (elems->supp_rates) { 133 clen = IEEE80211_MAX_SUPP_RATES; 134 if (clen > elems->supp_rates_len) 135 clen = elems->supp_rates_len; 136 memcpy(bss->supp_rates, elems->supp_rates, clen); 137 srlen += clen; 138 } 139 if (elems->ext_supp_rates) { 140 clen = IEEE80211_MAX_SUPP_RATES - srlen; 141 if (clen > elems->ext_supp_rates_len) 142 clen = elems->ext_supp_rates_len; 143 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, 144 clen); 145 srlen += clen; 146 } 147 if (srlen) { 148 bss->supp_rates_len = srlen; 149 if (!elems->parse_error) 150 bss->valid_data |= IEEE80211_BSS_VALID_RATES; 151 } 152 } 153 154 if (!elems->parse_error || 155 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { 156 bss->wmm_used = elems->wmm_param || elems->wmm_info; 157 bss->uapsd_supported = is_uapsd_supported(elems); 158 if (!elems->parse_error) 159 bss->valid_data |= IEEE80211_BSS_VALID_WMM; 160 } 161 162 if (!beacon) 163 bss->last_probe_resp = jiffies; 164 165 return bss; 166 } 167 168 ieee80211_rx_result 169 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 170 { 171 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); 172 struct ieee80211_mgmt *mgmt; 173 struct ieee80211_bss *bss; 174 u8 *elements; 175 struct ieee80211_channel *channel; 176 size_t baselen; 177 int freq; 178 __le16 fc; 179 bool presp, beacon = false; 180 struct ieee802_11_elems elems; 181 182 if (skb->len < 2) 183 return RX_DROP_UNUSABLE; 184 185 mgmt = (struct ieee80211_mgmt *) skb->data; 186 fc = mgmt->frame_control; 187 188 if (ieee80211_is_ctl(fc)) 189 return RX_CONTINUE; 190 191 if (skb->len < 24) 192 return RX_CONTINUE; 193 194 presp = ieee80211_is_probe_resp(fc); 195 if (presp) { 196 /* ignore ProbeResp to foreign address */ 197 if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) 198 return RX_DROP_MONITOR; 199 200 presp = true; 201 elements = mgmt->u.probe_resp.variable; 202 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); 203 } else { 204 beacon = ieee80211_is_beacon(fc); 205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); 206 elements = mgmt->u.beacon.variable; 207 } 208 209 if (!presp && !beacon) 210 return RX_CONTINUE; 211 212 if (baselen > skb->len) 213 return RX_DROP_MONITOR; 214 215 ieee802_11_parse_elems(elements, skb->len - baselen, &elems); 216 217 if (elems.ds_params && elems.ds_params_len == 1) 218 freq = ieee80211_channel_to_frequency(elems.ds_params[0], 219 rx_status->band); 220 else 221 freq = rx_status->freq; 222 223 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); 224 225 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 226 return RX_DROP_MONITOR; 227 228 bss = ieee80211_bss_info_update(sdata->local, rx_status, 229 mgmt, skb->len, &elems, 230 channel, beacon); 231 if (bss) 232 ieee80211_rx_bss_put(sdata->local, bss); 233 234 if (channel == sdata->local->oper_channel) 235 return RX_CONTINUE; 236 237 dev_kfree_skb(skb); 238 return RX_QUEUED; 239 } 240 241 /* return false if no more work */ 242 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 243 { 244 struct cfg80211_scan_request *req = local->scan_req; 245 enum ieee80211_band band; 246 int i, ielen, n_chans; 247 248 do { 249 if (local->hw_scan_band == IEEE80211_NUM_BANDS) 250 return false; 251 252 band = local->hw_scan_band; 253 n_chans = 0; 254 for (i = 0; i < req->n_channels; i++) { 255 if (req->channels[i]->band == band) { 256 local->hw_scan_req->channels[n_chans] = 257 req->channels[i]; 258 n_chans++; 259 } 260 } 261 262 local->hw_scan_band++; 263 } while (!n_chans); 264 265 local->hw_scan_req->n_channels = n_chans; 266 267 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, 268 req->ie, req->ie_len, band, 269 req->rates[band], 0); 270 local->hw_scan_req->ie_len = ielen; 271 local->hw_scan_req->no_cck = req->no_cck; 272 273 return true; 274 } 275 276 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, 277 bool was_hw_scan) 278 { 279 struct ieee80211_local *local = hw_to_local(hw); 280 281 lockdep_assert_held(&local->mtx); 282 283 /* 284 * It's ok to abort a not-yet-running scan (that 285 * we have one at all will be verified by checking 286 * local->scan_req next), but not to complete it 287 * successfully. 288 */ 289 if (WARN_ON(!local->scanning && !aborted)) 290 aborted = true; 291 292 if (WARN_ON(!local->scan_req)) 293 return; 294 295 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { 296 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); 297 if (rc == 0) 298 return; 299 } 300 301 kfree(local->hw_scan_req); 302 local->hw_scan_req = NULL; 303 304 if (local->scan_req != local->int_scan_req) 305 cfg80211_scan_done(local->scan_req, aborted); 306 local->scan_req = NULL; 307 local->scan_sdata = NULL; 308 309 local->scanning = 0; 310 local->scan_channel = NULL; 311 312 /* Set power back to normal operating levels. */ 313 ieee80211_hw_config(local, 0); 314 315 if (!was_hw_scan) { 316 ieee80211_configure_filter(local); 317 drv_sw_scan_complete(local); 318 ieee80211_offchannel_return(local, 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 = jiffies; 360 local->next_scan_state = SCAN_DECISION; 361 local->scan_channel_idx = 0; 362 363 ieee80211_offchannel_stop_vifs(local, true); 364 365 ieee80211_configure_filter(local); 366 367 /* We need to set power level at maximum rate for scanning. */ 368 ieee80211_hw_config(local, 0); 369 370 ieee80211_queue_delayed_work(&local->hw, 371 &local->scan_work, 0); 372 373 return 0; 374 } 375 376 static bool ieee80211_can_scan(struct ieee80211_local *local, 377 struct ieee80211_sub_if_data *sdata) 378 { 379 if (!list_empty(&local->work_list)) 380 return false; 381 382 if (sdata->vif.type == NL80211_IFTYPE_STATION && 383 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL | 384 IEEE80211_STA_CONNECTION_POLL)) 385 return false; 386 387 return true; 388 } 389 390 void ieee80211_run_deferred_scan(struct ieee80211_local *local) 391 { 392 lockdep_assert_held(&local->mtx); 393 394 if (!local->scan_req || local->scanning) 395 return; 396 397 if (!ieee80211_can_scan(local, local->scan_sdata)) 398 return; 399 400 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 401 round_jiffies_relative(0)); 402 } 403 404 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, 405 unsigned long *next_delay) 406 { 407 int i; 408 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 409 enum ieee80211_band band = local->hw.conf.channel->band; 410 411 for (i = 0; i < local->scan_req->n_ssids; i++) 412 ieee80211_send_probe_req( 413 sdata, NULL, 414 local->scan_req->ssids[i].ssid, 415 local->scan_req->ssids[i].ssid_len, 416 local->scan_req->ie, local->scan_req->ie_len, 417 local->scan_req->rates[band], false, 418 local->scan_req->no_cck); 419 420 /* 421 * After sending probe requests, wait for probe responses 422 * on the channel. 423 */ 424 *next_delay = IEEE80211_CHANNEL_TIME; 425 local->next_scan_state = SCAN_DECISION; 426 } 427 428 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, 429 struct cfg80211_scan_request *req) 430 { 431 struct ieee80211_local *local = sdata->local; 432 int rc; 433 434 lockdep_assert_held(&local->mtx); 435 436 if (local->scan_req) 437 return -EBUSY; 438 439 if (!ieee80211_can_scan(local, sdata)) { 440 /* wait for the work to finish/time out */ 441 local->scan_req = req; 442 local->scan_sdata = sdata; 443 return 0; 444 } 445 446 if (local->ops->hw_scan) { 447 u8 *ies; 448 449 local->hw_scan_req = kmalloc( 450 sizeof(*local->hw_scan_req) + 451 req->n_channels * sizeof(req->channels[0]) + 452 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + 453 req->ie_len, GFP_KERNEL); 454 if (!local->hw_scan_req) 455 return -ENOMEM; 456 457 local->hw_scan_req->ssids = req->ssids; 458 local->hw_scan_req->n_ssids = req->n_ssids; 459 ies = (u8 *)local->hw_scan_req + 460 sizeof(*local->hw_scan_req) + 461 req->n_channels * sizeof(req->channels[0]); 462 local->hw_scan_req->ie = ies; 463 464 local->hw_scan_band = 0; 465 466 /* 467 * After allocating local->hw_scan_req, we must 468 * go through until ieee80211_prep_hw_scan(), so 469 * anything that might be changed here and leave 470 * this function early must not go after this 471 * allocation. 472 */ 473 } 474 475 local->scan_req = req; 476 local->scan_sdata = sdata; 477 478 if (local->ops->hw_scan) { 479 __set_bit(SCAN_HW_SCANNING, &local->scanning); 480 } else if ((req->n_channels == 1) && 481 (req->channels[0]->center_freq == 482 local->hw.conf.channel->center_freq)) { 483 484 /* If we are scanning only on the current channel, then 485 * we do not need to stop normal activities 486 */ 487 unsigned long next_delay; 488 489 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); 490 491 ieee80211_recalc_idle(local); 492 493 /* Notify driver scan is starting, keep order of operations 494 * same as normal software scan, in case that matters. */ 495 drv_sw_scan_start(local); 496 497 ieee80211_configure_filter(local); /* accept probe-responses */ 498 499 /* We need to ensure power level is at max for scanning. */ 500 ieee80211_hw_config(local, 0); 501 502 if ((req->channels[0]->flags & 503 IEEE80211_CHAN_PASSIVE_SCAN) || 504 !local->scan_req->n_ssids) { 505 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 506 } else { 507 ieee80211_scan_state_send_probe(local, &next_delay); 508 next_delay = IEEE80211_CHANNEL_TIME; 509 } 510 511 /* Now, just wait a bit and we are all done! */ 512 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 513 next_delay); 514 return 0; 515 } else { 516 /* Do normal software scan */ 517 __set_bit(SCAN_SW_SCANNING, &local->scanning); 518 } 519 520 ieee80211_recalc_idle(local); 521 522 if (local->ops->hw_scan) { 523 WARN_ON(!ieee80211_prep_hw_scan(local)); 524 rc = drv_hw_scan(local, sdata, local->hw_scan_req); 525 } else 526 rc = ieee80211_start_sw_scan(local); 527 528 if (rc) { 529 kfree(local->hw_scan_req); 530 local->hw_scan_req = NULL; 531 local->scanning = 0; 532 533 ieee80211_recalc_idle(local); 534 535 local->scan_req = NULL; 536 local->scan_sdata = NULL; 537 } 538 539 return rc; 540 } 541 542 static unsigned long 543 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) 544 { 545 /* 546 * TODO: channel switching also consumes quite some time, 547 * add that delay as well to get a better estimation 548 */ 549 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) 550 return IEEE80211_PASSIVE_CHANNEL_TIME; 551 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; 552 } 553 554 static void ieee80211_scan_state_decision(struct ieee80211_local *local, 555 unsigned long *next_delay) 556 { 557 bool associated = false; 558 bool tx_empty = true; 559 bool bad_latency; 560 bool listen_int_exceeded; 561 unsigned long min_beacon_int = 0; 562 struct ieee80211_sub_if_data *sdata; 563 struct ieee80211_channel *next_chan; 564 565 /* 566 * check if at least one STA interface is associated, 567 * check if at least one STA interface has pending tx frames 568 * and grab the lowest used beacon interval 569 */ 570 mutex_lock(&local->iflist_mtx); 571 list_for_each_entry(sdata, &local->interfaces, list) { 572 if (!ieee80211_sdata_running(sdata)) 573 continue; 574 575 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 576 if (sdata->u.mgd.associated) { 577 associated = true; 578 579 if (sdata->vif.bss_conf.beacon_int < 580 min_beacon_int || min_beacon_int == 0) 581 min_beacon_int = 582 sdata->vif.bss_conf.beacon_int; 583 584 if (!qdisc_all_tx_empty(sdata->dev)) { 585 tx_empty = false; 586 break; 587 } 588 } 589 } 590 } 591 mutex_unlock(&local->iflist_mtx); 592 593 next_chan = local->scan_req->channels[local->scan_channel_idx]; 594 595 /* 596 * we're currently scanning a different channel, let's 597 * see if we can scan another channel without interfering 598 * with the current traffic situation. 599 * 600 * Since we don't know if the AP has pending frames for us 601 * we can only check for our tx queues and use the current 602 * pm_qos requirements for rx. Hence, if no tx traffic occurs 603 * at all we will scan as many channels in a row as the pm_qos 604 * latency allows us to. Additionally we also check for the 605 * currently negotiated listen interval to prevent losing 606 * frames unnecessarily. 607 * 608 * Otherwise switch back to the operating channel. 609 */ 610 611 bad_latency = time_after(jiffies + 612 ieee80211_scan_get_channel_time(next_chan), 613 local->leave_oper_channel_time + 614 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); 615 616 listen_int_exceeded = time_after(jiffies + 617 ieee80211_scan_get_channel_time(next_chan), 618 local->leave_oper_channel_time + 619 usecs_to_jiffies(min_beacon_int * 1024) * 620 local->hw.conf.listen_interval); 621 622 if (associated && (!tx_empty || bad_latency || listen_int_exceeded)) 623 local->next_scan_state = SCAN_SUSPEND; 624 else 625 local->next_scan_state = SCAN_SET_CHANNEL; 626 627 *next_delay = 0; 628 } 629 630 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, 631 unsigned long *next_delay) 632 { 633 int skip; 634 struct ieee80211_channel *chan; 635 636 skip = 0; 637 chan = local->scan_req->channels[local->scan_channel_idx]; 638 639 local->scan_channel = chan; 640 641 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) 642 skip = 1; 643 644 /* advance state machine to next channel/band */ 645 local->scan_channel_idx++; 646 647 if (skip) { 648 /* if we skip this channel return to the decision state */ 649 local->next_scan_state = SCAN_DECISION; 650 return; 651 } 652 653 /* 654 * Probe delay is used to update the NAV, cf. 11.1.3.2.2 655 * (which unfortunately doesn't say _why_ step a) is done, 656 * but it waits for the probe delay or until a frame is 657 * received - and the received frame would update the NAV). 658 * For now, we do not support waiting until a frame is 659 * received. 660 * 661 * In any case, it is not necessary for a passive scan. 662 */ 663 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || 664 !local->scan_req->n_ssids) { 665 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; 666 local->next_scan_state = SCAN_DECISION; 667 return; 668 } 669 670 /* active scan, send probes */ 671 *next_delay = IEEE80211_PROBE_DELAY; 672 local->next_scan_state = SCAN_SEND_PROBE; 673 } 674 675 static void ieee80211_scan_state_suspend(struct ieee80211_local *local, 676 unsigned long *next_delay) 677 { 678 /* switch back to the operating channel */ 679 local->scan_channel = NULL; 680 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 681 682 /* 683 * Re-enable vifs and beaconing. Leave PS 684 * in off-channel state..will put that back 685 * on-channel at the end of scanning. 686 */ 687 ieee80211_offchannel_return(local, false); 688 689 *next_delay = HZ / 5; 690 /* afterwards, resume scan & go to next channel */ 691 local->next_scan_state = SCAN_RESUME; 692 } 693 694 static void ieee80211_scan_state_resume(struct ieee80211_local *local, 695 unsigned long *next_delay) 696 { 697 /* PS already is in off-channel mode */ 698 ieee80211_offchannel_stop_vifs(local, false); 699 700 if (local->ops->flush) { 701 drv_flush(local, false); 702 *next_delay = 0; 703 } else 704 *next_delay = HZ / 10; 705 706 /* remember when we left the operating channel */ 707 local->leave_oper_channel_time = jiffies; 708 709 /* advance to the next channel to be scanned */ 710 local->next_scan_state = SCAN_SET_CHANNEL; 711 } 712 713 void ieee80211_scan_work(struct work_struct *work) 714 { 715 struct ieee80211_local *local = 716 container_of(work, struct ieee80211_local, scan_work.work); 717 struct ieee80211_sub_if_data *sdata; 718 unsigned long next_delay = 0; 719 bool aborted, hw_scan; 720 721 mutex_lock(&local->mtx); 722 723 sdata = local->scan_sdata; 724 725 /* When scanning on-channel, the first-callback means completed. */ 726 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { 727 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 728 goto out_complete; 729 } 730 731 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { 732 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); 733 goto out_complete; 734 } 735 736 if (!sdata || !local->scan_req) 737 goto out; 738 739 if (local->scan_req && !local->scanning) { 740 struct cfg80211_scan_request *req = local->scan_req; 741 int rc; 742 743 local->scan_req = NULL; 744 local->scan_sdata = NULL; 745 746 rc = __ieee80211_start_scan(sdata, req); 747 if (rc) { 748 /* need to complete scan in cfg80211 */ 749 local->scan_req = req; 750 aborted = true; 751 goto out_complete; 752 } else 753 goto out; 754 } 755 756 /* 757 * Avoid re-scheduling when the sdata is going away. 758 */ 759 if (!ieee80211_sdata_running(sdata)) { 760 aborted = true; 761 goto out_complete; 762 } 763 764 /* 765 * as long as no delay is required advance immediately 766 * without scheduling a new work 767 */ 768 do { 769 if (!ieee80211_sdata_running(sdata)) { 770 aborted = true; 771 goto out_complete; 772 } 773 774 switch (local->next_scan_state) { 775 case SCAN_DECISION: 776 /* if no more bands/channels left, complete scan */ 777 if (local->scan_channel_idx >= local->scan_req->n_channels) { 778 aborted = false; 779 goto out_complete; 780 } 781 ieee80211_scan_state_decision(local, &next_delay); 782 break; 783 case SCAN_SET_CHANNEL: 784 ieee80211_scan_state_set_channel(local, &next_delay); 785 break; 786 case SCAN_SEND_PROBE: 787 ieee80211_scan_state_send_probe(local, &next_delay); 788 break; 789 case SCAN_SUSPEND: 790 ieee80211_scan_state_suspend(local, &next_delay); 791 break; 792 case SCAN_RESUME: 793 ieee80211_scan_state_resume(local, &next_delay); 794 break; 795 } 796 } while (next_delay == 0); 797 798 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); 799 goto out; 800 801 out_complete: 802 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); 803 __ieee80211_scan_completed(&local->hw, aborted, hw_scan); 804 out: 805 mutex_unlock(&local->mtx); 806 } 807 808 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, 809 struct cfg80211_scan_request *req) 810 { 811 int res; 812 813 mutex_lock(&sdata->local->mtx); 814 res = __ieee80211_start_scan(sdata, req); 815 mutex_unlock(&sdata->local->mtx); 816 817 return res; 818 } 819 820 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, 821 const u8 *ssid, u8 ssid_len, 822 struct ieee80211_channel *chan) 823 { 824 struct ieee80211_local *local = sdata->local; 825 int ret = -EBUSY; 826 enum ieee80211_band band; 827 828 mutex_lock(&local->mtx); 829 830 /* busy scanning */ 831 if (local->scan_req) 832 goto unlock; 833 834 /* fill internal scan request */ 835 if (!chan) { 836 int i, nchan = 0; 837 838 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 839 if (!local->hw.wiphy->bands[band]) 840 continue; 841 for (i = 0; 842 i < local->hw.wiphy->bands[band]->n_channels; 843 i++) { 844 local->int_scan_req->channels[nchan] = 845 &local->hw.wiphy->bands[band]->channels[i]; 846 nchan++; 847 } 848 } 849 850 local->int_scan_req->n_channels = nchan; 851 } else { 852 local->int_scan_req->channels[0] = chan; 853 local->int_scan_req->n_channels = 1; 854 } 855 856 local->int_scan_req->ssids = &local->scan_ssid; 857 local->int_scan_req->n_ssids = 1; 858 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); 859 local->int_scan_req->ssids[0].ssid_len = ssid_len; 860 861 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); 862 unlock: 863 mutex_unlock(&local->mtx); 864 return ret; 865 } 866 867 /* 868 * Only call this function when a scan can't be queued -- under RTNL. 869 */ 870 void ieee80211_scan_cancel(struct ieee80211_local *local) 871 { 872 /* 873 * We are canceling software scan, or deferred scan that was not 874 * yet really started (see __ieee80211_start_scan ). 875 * 876 * Regarding hardware scan: 877 * - we can not call __ieee80211_scan_completed() as when 878 * SCAN_HW_SCANNING bit is set this function change 879 * local->hw_scan_req to operate on 5G band, what race with 880 * driver which can use local->hw_scan_req 881 * 882 * - we can not cancel scan_work since driver can schedule it 883 * by ieee80211_scan_completed(..., true) to finish scan 884 * 885 * Hence we only call the cancel_hw_scan() callback, but the low-level 886 * driver is still responsible for calling ieee80211_scan_completed() 887 * after the scan was completed/aborted. 888 */ 889 890 mutex_lock(&local->mtx); 891 if (!local->scan_req) 892 goto out; 893 894 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { 895 if (local->ops->cancel_hw_scan) 896 drv_cancel_hw_scan(local, local->scan_sdata); 897 goto out; 898 } 899 900 /* 901 * If the work is currently running, it must be blocked on 902 * the mutex, but we'll set scan_sdata = NULL and it'll 903 * simply exit once it acquires the mutex. 904 */ 905 cancel_delayed_work(&local->scan_work); 906 /* and clean up */ 907 __ieee80211_scan_completed(&local->hw, true, false); 908 out: 909 mutex_unlock(&local->mtx); 910 } 911 912 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, 913 struct cfg80211_sched_scan_request *req) 914 { 915 struct ieee80211_local *local = sdata->local; 916 int ret, i; 917 918 mutex_lock(&sdata->local->mtx); 919 920 if (local->sched_scanning) { 921 ret = -EBUSY; 922 goto out; 923 } 924 925 if (!local->ops->sched_scan_start) { 926 ret = -ENOTSUPP; 927 goto out; 928 } 929 930 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 931 local->sched_scan_ies.ie[i] = kzalloc(2 + 932 IEEE80211_MAX_SSID_LEN + 933 local->scan_ies_len + 934 req->ie_len, 935 GFP_KERNEL); 936 if (!local->sched_scan_ies.ie[i]) { 937 ret = -ENOMEM; 938 goto out_free; 939 } 940 941 local->sched_scan_ies.len[i] = 942 ieee80211_build_preq_ies(local, 943 local->sched_scan_ies.ie[i], 944 req->ie, req->ie_len, i, 945 (u32) -1, 0); 946 } 947 948 ret = drv_sched_scan_start(local, sdata, req, 949 &local->sched_scan_ies); 950 if (ret == 0) { 951 local->sched_scanning = true; 952 goto out; 953 } 954 955 out_free: 956 while (i > 0) 957 kfree(local->sched_scan_ies.ie[--i]); 958 out: 959 mutex_unlock(&sdata->local->mtx); 960 return ret; 961 } 962 963 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) 964 { 965 struct ieee80211_local *local = sdata->local; 966 int ret = 0, i; 967 968 mutex_lock(&sdata->local->mtx); 969 970 if (!local->ops->sched_scan_stop) { 971 ret = -ENOTSUPP; 972 goto out; 973 } 974 975 if (local->sched_scanning) { 976 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 977 kfree(local->sched_scan_ies.ie[i]); 978 979 drv_sched_scan_stop(local, sdata); 980 local->sched_scanning = false; 981 } 982 out: 983 mutex_unlock(&sdata->local->mtx); 984 985 return ret; 986 } 987 988 void ieee80211_sched_scan_results(struct ieee80211_hw *hw) 989 { 990 struct ieee80211_local *local = hw_to_local(hw); 991 992 trace_api_sched_scan_results(local); 993 994 cfg80211_sched_scan_results(hw->wiphy); 995 } 996 EXPORT_SYMBOL(ieee80211_sched_scan_results); 997 998 void ieee80211_sched_scan_stopped_work(struct work_struct *work) 999 { 1000 struct ieee80211_local *local = 1001 container_of(work, struct ieee80211_local, 1002 sched_scan_stopped_work); 1003 int i; 1004 1005 mutex_lock(&local->mtx); 1006 1007 if (!local->sched_scanning) { 1008 mutex_unlock(&local->mtx); 1009 return; 1010 } 1011 1012 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 1013 kfree(local->sched_scan_ies.ie[i]); 1014 1015 local->sched_scanning = false; 1016 1017 mutex_unlock(&local->mtx); 1018 1019 cfg80211_sched_scan_stopped(local->hw.wiphy); 1020 } 1021 1022 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) 1023 { 1024 struct ieee80211_local *local = hw_to_local(hw); 1025 1026 trace_api_sched_scan_stopped(local); 1027 1028 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); 1029 } 1030 EXPORT_SYMBOL(ieee80211_sched_scan_stopped); 1031