scan.c revision 15d6030b4bec618742b8b9ccae9209c8f9e4a916
1/* 2 * cfg80211 scan result handling 3 * 4 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net> 5 */ 6#include <linux/kernel.h> 7#include <linux/slab.h> 8#include <linux/module.h> 9#include <linux/netdevice.h> 10#include <linux/wireless.h> 11#include <linux/nl80211.h> 12#include <linux/etherdevice.h> 13#include <net/arp.h> 14#include <net/cfg80211.h> 15#include <net/cfg80211-wext.h> 16#include <net/iw_handler.h> 17#include "core.h" 18#include "nl80211.h" 19#include "wext-compat.h" 20 21#define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) 22 23static void bss_release(struct kref *ref) 24{ 25 struct cfg80211_internal_bss *bss; 26 27 bss = container_of(ref, struct cfg80211_internal_bss, ref); 28 if (bss->pub.free_priv) 29 bss->pub.free_priv(&bss->pub); 30 31 if (bss->beacon_ies_allocated) 32 kfree(bss->pub.beacon_ies); 33 if (bss->proberesp_ies_allocated) 34 kfree(bss->pub.proberesp_ies); 35 36 BUG_ON(atomic_read(&bss->hold)); 37 38 kfree(bss); 39} 40 41/* must hold dev->bss_lock! */ 42static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev, 43 struct cfg80211_internal_bss *bss) 44{ 45 list_del_init(&bss->list); 46 rb_erase(&bss->rbn, &dev->bss_tree); 47 kref_put(&bss->ref, bss_release); 48} 49 50/* must hold dev->bss_lock! */ 51static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev, 52 unsigned long expire_time) 53{ 54 struct cfg80211_internal_bss *bss, *tmp; 55 bool expired = false; 56 57 list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) { 58 if (atomic_read(&bss->hold)) 59 continue; 60 if (!time_after(expire_time, bss->ts)) 61 continue; 62 63 __cfg80211_unlink_bss(dev, bss); 64 expired = true; 65 } 66 67 if (expired) 68 dev->bss_generation++; 69} 70 71void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) 72{ 73 struct cfg80211_scan_request *request; 74 struct wireless_dev *wdev; 75#ifdef CONFIG_CFG80211_WEXT 76 union iwreq_data wrqu; 77#endif 78 79 ASSERT_RDEV_LOCK(rdev); 80 81 request = rdev->scan_req; 82 83 if (!request) 84 return; 85 86 wdev = request->wdev; 87 88 /* 89 * This must be before sending the other events! 90 * Otherwise, wpa_supplicant gets completely confused with 91 * wext events. 92 */ 93 if (wdev->netdev) 94 cfg80211_sme_scan_done(wdev->netdev); 95 96 if (request->aborted) { 97 nl80211_send_scan_aborted(rdev, wdev); 98 } else { 99 if (request->flags & NL80211_SCAN_FLAG_FLUSH) { 100 /* flush entries from previous scans */ 101 spin_lock_bh(&rdev->bss_lock); 102 __cfg80211_bss_expire(rdev, request->scan_start); 103 spin_unlock_bh(&rdev->bss_lock); 104 } 105 nl80211_send_scan_done(rdev, wdev); 106 } 107 108#ifdef CONFIG_CFG80211_WEXT 109 if (wdev->netdev && !request->aborted) { 110 memset(&wrqu, 0, sizeof(wrqu)); 111 112 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL); 113 } 114#endif 115 116 if (wdev->netdev) 117 dev_put(wdev->netdev); 118 119 rdev->scan_req = NULL; 120 121 /* 122 * OK. If this is invoked with "leak" then we can't 123 * free this ... but we've cleaned it up anyway. The 124 * driver failed to call the scan_done callback, so 125 * all bets are off, it might still be trying to use 126 * the scan request or not ... if it accesses the dev 127 * in there (it shouldn't anyway) then it may crash. 128 */ 129 if (!leak) 130 kfree(request); 131} 132 133void __cfg80211_scan_done(struct work_struct *wk) 134{ 135 struct cfg80211_registered_device *rdev; 136 137 rdev = container_of(wk, struct cfg80211_registered_device, 138 scan_done_wk); 139 140 cfg80211_lock_rdev(rdev); 141 ___cfg80211_scan_done(rdev, false); 142 cfg80211_unlock_rdev(rdev); 143} 144 145void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted) 146{ 147 WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req); 148 149 request->aborted = aborted; 150 queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk); 151} 152EXPORT_SYMBOL(cfg80211_scan_done); 153 154void __cfg80211_sched_scan_results(struct work_struct *wk) 155{ 156 struct cfg80211_registered_device *rdev; 157 struct cfg80211_sched_scan_request *request; 158 159 rdev = container_of(wk, struct cfg80211_registered_device, 160 sched_scan_results_wk); 161 162 request = rdev->sched_scan_req; 163 164 mutex_lock(&rdev->sched_scan_mtx); 165 166 /* we don't have sched_scan_req anymore if the scan is stopping */ 167 if (request) { 168 if (request->flags & NL80211_SCAN_FLAG_FLUSH) { 169 /* flush entries from previous scans */ 170 spin_lock_bh(&rdev->bss_lock); 171 __cfg80211_bss_expire(rdev, request->scan_start); 172 spin_unlock_bh(&rdev->bss_lock); 173 request->scan_start = 174 jiffies + msecs_to_jiffies(request->interval); 175 } 176 nl80211_send_sched_scan_results(rdev, request->dev); 177 } 178 179 mutex_unlock(&rdev->sched_scan_mtx); 180} 181 182void cfg80211_sched_scan_results(struct wiphy *wiphy) 183{ 184 /* ignore if we're not scanning */ 185 if (wiphy_to_dev(wiphy)->sched_scan_req) 186 queue_work(cfg80211_wq, 187 &wiphy_to_dev(wiphy)->sched_scan_results_wk); 188} 189EXPORT_SYMBOL(cfg80211_sched_scan_results); 190 191void cfg80211_sched_scan_stopped(struct wiphy *wiphy) 192{ 193 struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy); 194 195 mutex_lock(&rdev->sched_scan_mtx); 196 __cfg80211_stop_sched_scan(rdev, true); 197 mutex_unlock(&rdev->sched_scan_mtx); 198} 199EXPORT_SYMBOL(cfg80211_sched_scan_stopped); 200 201int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, 202 bool driver_initiated) 203{ 204 struct net_device *dev; 205 206 lockdep_assert_held(&rdev->sched_scan_mtx); 207 208 if (!rdev->sched_scan_req) 209 return -ENOENT; 210 211 dev = rdev->sched_scan_req->dev; 212 213 if (!driver_initiated) { 214 int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev); 215 if (err) 216 return err; 217 } 218 219 nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED); 220 221 kfree(rdev->sched_scan_req); 222 rdev->sched_scan_req = NULL; 223 224 return 0; 225} 226 227/* must hold dev->bss_lock! */ 228void cfg80211_bss_age(struct cfg80211_registered_device *dev, 229 unsigned long age_secs) 230{ 231 struct cfg80211_internal_bss *bss; 232 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); 233 234 list_for_each_entry(bss, &dev->bss_list, list) { 235 bss->ts -= age_jiffies; 236 } 237} 238 239void cfg80211_bss_expire(struct cfg80211_registered_device *dev) 240{ 241 __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); 242} 243 244const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len) 245{ 246 while (len > 2 && ies[0] != eid) { 247 len -= ies[1] + 2; 248 ies += ies[1] + 2; 249 } 250 if (len < 2) 251 return NULL; 252 if (len < 2 + ies[1]) 253 return NULL; 254 return ies; 255} 256EXPORT_SYMBOL(cfg80211_find_ie); 257 258const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type, 259 const u8 *ies, int len) 260{ 261 struct ieee80211_vendor_ie *ie; 262 const u8 *pos = ies, *end = ies + len; 263 int ie_oui; 264 265 while (pos < end) { 266 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos, 267 end - pos); 268 if (!pos) 269 return NULL; 270 271 if (end - pos < sizeof(*ie)) 272 return NULL; 273 274 ie = (struct ieee80211_vendor_ie *)pos; 275 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2]; 276 if (ie_oui == oui && ie->oui_type == oui_type) 277 return pos; 278 279 pos += 2 + ie->len; 280 } 281 return NULL; 282} 283EXPORT_SYMBOL(cfg80211_find_vendor_ie); 284 285static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2) 286{ 287 const u8 *ie1 = cfg80211_find_ie(num, ies1, len1); 288 const u8 *ie2 = cfg80211_find_ie(num, ies2, len2); 289 290 /* equal if both missing */ 291 if (!ie1 && !ie2) 292 return 0; 293 /* sort missing IE before (left of) present IE */ 294 if (!ie1) 295 return -1; 296 if (!ie2) 297 return 1; 298 299 /* sort by length first, then by contents */ 300 if (ie1[1] != ie2[1]) 301 return ie2[1] - ie1[1]; 302 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 303} 304 305static bool is_bss(struct cfg80211_bss *a, 306 const u8 *bssid, 307 const u8 *ssid, size_t ssid_len) 308{ 309 const u8 *ssidie; 310 311 if (bssid && !ether_addr_equal(a->bssid, bssid)) 312 return false; 313 314 if (!ssid) 315 return true; 316 317 ssidie = cfg80211_find_ie(WLAN_EID_SSID, 318 a->information_elements, 319 a->len_information_elements); 320 if (!ssidie) 321 return false; 322 if (ssidie[1] != ssid_len) 323 return false; 324 return memcmp(ssidie + 2, ssid, ssid_len) == 0; 325} 326 327static bool is_mesh_bss(struct cfg80211_bss *a) 328{ 329 const u8 *ie; 330 331 if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability)) 332 return false; 333 334 ie = cfg80211_find_ie(WLAN_EID_MESH_ID, 335 a->information_elements, 336 a->len_information_elements); 337 if (!ie) 338 return false; 339 340 ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 341 a->information_elements, 342 a->len_information_elements); 343 if (!ie) 344 return false; 345 346 return true; 347} 348 349static bool is_mesh(struct cfg80211_bss *a, 350 const u8 *meshid, size_t meshidlen, 351 const u8 *meshcfg) 352{ 353 const u8 *ie; 354 355 if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability)) 356 return false; 357 358 ie = cfg80211_find_ie(WLAN_EID_MESH_ID, 359 a->information_elements, 360 a->len_information_elements); 361 if (!ie) 362 return false; 363 if (ie[1] != meshidlen) 364 return false; 365 if (memcmp(ie + 2, meshid, meshidlen)) 366 return false; 367 368 ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 369 a->information_elements, 370 a->len_information_elements); 371 if (!ie) 372 return false; 373 if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) 374 return false; 375 376 /* 377 * Ignore mesh capability (last two bytes of the IE) when 378 * comparing since that may differ between stations taking 379 * part in the same mesh. 380 */ 381 return memcmp(ie + 2, meshcfg, 382 sizeof(struct ieee80211_meshconf_ie) - 2) == 0; 383} 384 385static int cmp_bss_core(struct cfg80211_bss *a, 386 struct cfg80211_bss *b) 387{ 388 int r; 389 390 if (a->channel != b->channel) 391 return b->channel->center_freq - a->channel->center_freq; 392 393 if (is_mesh_bss(a) && is_mesh_bss(b)) { 394 r = cmp_ies(WLAN_EID_MESH_ID, 395 a->information_elements, 396 a->len_information_elements, 397 b->information_elements, 398 b->len_information_elements); 399 if (r) 400 return r; 401 return cmp_ies(WLAN_EID_MESH_CONFIG, 402 a->information_elements, 403 a->len_information_elements, 404 b->information_elements, 405 b->len_information_elements); 406 } 407 408 /* 409 * we can't use compare_ether_addr here since we need a < > operator. 410 * The binary return value of compare_ether_addr isn't enough 411 */ 412 return memcmp(a->bssid, b->bssid, sizeof(a->bssid)); 413} 414 415static int cmp_bss(struct cfg80211_bss *a, 416 struct cfg80211_bss *b) 417{ 418 int r; 419 420 r = cmp_bss_core(a, b); 421 if (r) 422 return r; 423 424 return cmp_ies(WLAN_EID_SSID, 425 a->information_elements, 426 a->len_information_elements, 427 b->information_elements, 428 b->len_information_elements); 429} 430 431static int cmp_hidden_bss(struct cfg80211_bss *a, 432 struct cfg80211_bss *b) 433{ 434 const u8 *ie1; 435 const u8 *ie2; 436 int i; 437 int r; 438 439 r = cmp_bss_core(a, b); 440 if (r) 441 return r; 442 443 ie1 = cfg80211_find_ie(WLAN_EID_SSID, 444 a->information_elements, 445 a->len_information_elements); 446 ie2 = cfg80211_find_ie(WLAN_EID_SSID, 447 b->information_elements, 448 b->len_information_elements); 449 450 /* Key comparator must use same algorithm in any rb-tree 451 * search function (order is important), otherwise ordering 452 * of items in the tree is broken and search gives incorrect 453 * results. This code uses same order as cmp_ies() does. */ 454 455 /* sort missing IE before (left of) present IE */ 456 if (!ie1) 457 return -1; 458 if (!ie2) 459 return 1; 460 461 /* zero-size SSID is used as an indication of the hidden bss */ 462 if (!ie2[1]) 463 return 0; 464 465 /* sort by length first, then by contents */ 466 if (ie1[1] != ie2[1]) 467 return ie2[1] - ie1[1]; 468 469 /* zeroed SSID ie is another indication of a hidden bss */ 470 for (i = 0; i < ie2[1]; i++) 471 if (ie2[i + 2]) 472 return -1; 473 474 return 0; 475} 476 477struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, 478 struct ieee80211_channel *channel, 479 const u8 *bssid, 480 const u8 *ssid, size_t ssid_len, 481 u16 capa_mask, u16 capa_val) 482{ 483 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); 484 struct cfg80211_internal_bss *bss, *res = NULL; 485 unsigned long now = jiffies; 486 487 spin_lock_bh(&dev->bss_lock); 488 489 list_for_each_entry(bss, &dev->bss_list, list) { 490 if ((bss->pub.capability & capa_mask) != capa_val) 491 continue; 492 if (channel && bss->pub.channel != channel) 493 continue; 494 /* Don't get expired BSS structs */ 495 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && 496 !atomic_read(&bss->hold)) 497 continue; 498 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { 499 res = bss; 500 kref_get(&res->ref); 501 break; 502 } 503 } 504 505 spin_unlock_bh(&dev->bss_lock); 506 if (!res) 507 return NULL; 508 return &res->pub; 509} 510EXPORT_SYMBOL(cfg80211_get_bss); 511 512struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy, 513 struct ieee80211_channel *channel, 514 const u8 *meshid, size_t meshidlen, 515 const u8 *meshcfg) 516{ 517 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); 518 struct cfg80211_internal_bss *bss, *res = NULL; 519 520 spin_lock_bh(&dev->bss_lock); 521 522 list_for_each_entry(bss, &dev->bss_list, list) { 523 if (channel && bss->pub.channel != channel) 524 continue; 525 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) { 526 res = bss; 527 kref_get(&res->ref); 528 break; 529 } 530 } 531 532 spin_unlock_bh(&dev->bss_lock); 533 if (!res) 534 return NULL; 535 return &res->pub; 536} 537EXPORT_SYMBOL(cfg80211_get_mesh); 538 539 540static void rb_insert_bss(struct cfg80211_registered_device *dev, 541 struct cfg80211_internal_bss *bss) 542{ 543 struct rb_node **p = &dev->bss_tree.rb_node; 544 struct rb_node *parent = NULL; 545 struct cfg80211_internal_bss *tbss; 546 int cmp; 547 548 while (*p) { 549 parent = *p; 550 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); 551 552 cmp = cmp_bss(&bss->pub, &tbss->pub); 553 554 if (WARN_ON(!cmp)) { 555 /* will sort of leak this BSS */ 556 return; 557 } 558 559 if (cmp < 0) 560 p = &(*p)->rb_left; 561 else 562 p = &(*p)->rb_right; 563 } 564 565 rb_link_node(&bss->rbn, parent, p); 566 rb_insert_color(&bss->rbn, &dev->bss_tree); 567} 568 569static struct cfg80211_internal_bss * 570rb_find_bss(struct cfg80211_registered_device *dev, 571 struct cfg80211_internal_bss *res) 572{ 573 struct rb_node *n = dev->bss_tree.rb_node; 574 struct cfg80211_internal_bss *bss; 575 int r; 576 577 while (n) { 578 bss = rb_entry(n, struct cfg80211_internal_bss, rbn); 579 r = cmp_bss(&res->pub, &bss->pub); 580 581 if (r == 0) 582 return bss; 583 else if (r < 0) 584 n = n->rb_left; 585 else 586 n = n->rb_right; 587 } 588 589 return NULL; 590} 591 592static struct cfg80211_internal_bss * 593rb_find_hidden_bss(struct cfg80211_registered_device *dev, 594 struct cfg80211_internal_bss *res) 595{ 596 struct rb_node *n = dev->bss_tree.rb_node; 597 struct cfg80211_internal_bss *bss; 598 int r; 599 600 while (n) { 601 bss = rb_entry(n, struct cfg80211_internal_bss, rbn); 602 r = cmp_hidden_bss(&res->pub, &bss->pub); 603 604 if (r == 0) 605 return bss; 606 else if (r < 0) 607 n = n->rb_left; 608 else 609 n = n->rb_right; 610 } 611 612 return NULL; 613} 614 615static void 616copy_hidden_ies(struct cfg80211_internal_bss *res, 617 struct cfg80211_internal_bss *hidden) 618{ 619 if (unlikely(res->pub.beacon_ies)) 620 return; 621 if (WARN_ON(!hidden->pub.beacon_ies)) 622 return; 623 624 res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC); 625 if (unlikely(!res->pub.beacon_ies)) 626 return; 627 628 res->beacon_ies_allocated = true; 629 res->pub.len_beacon_ies = hidden->pub.len_beacon_ies; 630 memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies, 631 res->pub.len_beacon_ies); 632} 633 634static struct cfg80211_internal_bss * 635cfg80211_bss_update(struct cfg80211_registered_device *dev, 636 struct cfg80211_internal_bss *res) 637{ 638 struct cfg80211_internal_bss *found = NULL; 639 640 /* 641 * The reference to "res" is donated to this function. 642 */ 643 644 if (WARN_ON(!res->pub.channel)) { 645 kref_put(&res->ref, bss_release); 646 return NULL; 647 } 648 649 res->ts = jiffies; 650 651 spin_lock_bh(&dev->bss_lock); 652 653 found = rb_find_bss(dev, res); 654 655 if (found) { 656 found->pub.beacon_interval = res->pub.beacon_interval; 657 found->pub.tsf = res->pub.tsf; 658 found->pub.signal = res->pub.signal; 659 found->pub.capability = res->pub.capability; 660 found->ts = res->ts; 661 662 /* Update IEs */ 663 if (res->pub.proberesp_ies) { 664 size_t used = dev->wiphy.bss_priv_size + sizeof(*res); 665 size_t ielen = res->pub.len_proberesp_ies; 666 667 if (found->pub.proberesp_ies && 668 !found->proberesp_ies_allocated && 669 ksize(found) >= used + ielen) { 670 memcpy(found->pub.proberesp_ies, 671 res->pub.proberesp_ies, ielen); 672 found->pub.len_proberesp_ies = ielen; 673 } else { 674 u8 *ies = found->pub.proberesp_ies; 675 676 if (found->proberesp_ies_allocated) 677 ies = krealloc(ies, ielen, GFP_ATOMIC); 678 else 679 ies = kmalloc(ielen, GFP_ATOMIC); 680 681 if (ies) { 682 memcpy(ies, res->pub.proberesp_ies, 683 ielen); 684 found->proberesp_ies_allocated = true; 685 found->pub.proberesp_ies = ies; 686 found->pub.len_proberesp_ies = ielen; 687 } 688 } 689 690 /* Override possible earlier Beacon frame IEs */ 691 found->pub.information_elements = 692 found->pub.proberesp_ies; 693 found->pub.len_information_elements = 694 found->pub.len_proberesp_ies; 695 } 696 if (res->pub.beacon_ies) { 697 size_t used = dev->wiphy.bss_priv_size + sizeof(*res); 698 size_t ielen = res->pub.len_beacon_ies; 699 bool information_elements_is_beacon_ies = 700 (found->pub.information_elements == 701 found->pub.beacon_ies); 702 703 if (found->pub.beacon_ies && 704 !found->beacon_ies_allocated && 705 ksize(found) >= used + ielen) { 706 memcpy(found->pub.beacon_ies, 707 res->pub.beacon_ies, ielen); 708 found->pub.len_beacon_ies = ielen; 709 } else { 710 u8 *ies = found->pub.beacon_ies; 711 712 if (found->beacon_ies_allocated) 713 ies = krealloc(ies, ielen, GFP_ATOMIC); 714 else 715 ies = kmalloc(ielen, GFP_ATOMIC); 716 717 if (ies) { 718 memcpy(ies, res->pub.beacon_ies, 719 ielen); 720 found->beacon_ies_allocated = true; 721 found->pub.beacon_ies = ies; 722 found->pub.len_beacon_ies = ielen; 723 } 724 } 725 726 /* Override IEs if they were from a beacon before */ 727 if (information_elements_is_beacon_ies) { 728 found->pub.information_elements = 729 found->pub.beacon_ies; 730 found->pub.len_information_elements = 731 found->pub.len_beacon_ies; 732 } 733 } 734 735 kref_put(&res->ref, bss_release); 736 } else { 737 struct cfg80211_internal_bss *hidden; 738 739 /* First check if the beacon is a probe response from 740 * a hidden bss. If so, copy beacon ies (with nullified 741 * ssid) into the probe response bss entry (with real ssid). 742 * It is required basically for PSM implementation 743 * (probe responses do not contain tim ie) */ 744 745 /* TODO: The code is not trying to update existing probe 746 * response bss entries when beacon ies are 747 * getting changed. */ 748 hidden = rb_find_hidden_bss(dev, res); 749 if (hidden) 750 copy_hidden_ies(res, hidden); 751 752 /* this "consumes" the reference */ 753 list_add_tail(&res->list, &dev->bss_list); 754 rb_insert_bss(dev, res); 755 found = res; 756 } 757 758 dev->bss_generation++; 759 spin_unlock_bh(&dev->bss_lock); 760 761 kref_get(&found->ref); 762 return found; 763} 764 765struct cfg80211_bss* 766cfg80211_inform_bss(struct wiphy *wiphy, 767 struct ieee80211_channel *channel, 768 const u8 *bssid, u64 tsf, u16 capability, 769 u16 beacon_interval, const u8 *ie, size_t ielen, 770 s32 signal, gfp_t gfp) 771{ 772 struct cfg80211_internal_bss *res; 773 size_t privsz; 774 775 if (WARN_ON(!wiphy)) 776 return NULL; 777 778 privsz = wiphy->bss_priv_size; 779 780 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 781 (signal < 0 || signal > 100))) 782 return NULL; 783 784 res = kzalloc(sizeof(*res) + privsz + ielen, gfp); 785 if (!res) 786 return NULL; 787 788 memcpy(res->pub.bssid, bssid, ETH_ALEN); 789 res->pub.channel = channel; 790 res->pub.signal = signal; 791 res->pub.tsf = tsf; 792 res->pub.beacon_interval = beacon_interval; 793 res->pub.capability = capability; 794 /* 795 * Since we do not know here whether the IEs are from a Beacon or Probe 796 * Response frame, we need to pick one of the options and only use it 797 * with the driver that does not provide the full Beacon/Probe Response 798 * frame. Use Beacon frame pointer to avoid indicating that this should 799 * override the information_elements pointer should we have received an 800 * earlier indication of Probe Response data. 801 * 802 * The initial buffer for the IEs is allocated with the BSS entry and 803 * is located after the private area. 804 */ 805 res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz; 806 memcpy(res->pub.beacon_ies, ie, ielen); 807 res->pub.len_beacon_ies = ielen; 808 res->pub.information_elements = res->pub.beacon_ies; 809 res->pub.len_information_elements = res->pub.len_beacon_ies; 810 811 kref_init(&res->ref); 812 813 res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); 814 if (!res) 815 return NULL; 816 817 if (res->pub.capability & WLAN_CAPABILITY_ESS) 818 regulatory_hint_found_beacon(wiphy, channel, gfp); 819 820 /* cfg80211_bss_update gives us a referenced result */ 821 return &res->pub; 822} 823EXPORT_SYMBOL(cfg80211_inform_bss); 824 825struct cfg80211_bss * 826cfg80211_inform_bss_frame(struct wiphy *wiphy, 827 struct ieee80211_channel *channel, 828 struct ieee80211_mgmt *mgmt, size_t len, 829 s32 signal, gfp_t gfp) 830{ 831 struct cfg80211_internal_bss *res; 832 size_t ielen = len - offsetof(struct ieee80211_mgmt, 833 u.probe_resp.variable); 834 size_t privsz; 835 836 if (WARN_ON(!mgmt)) 837 return NULL; 838 839 if (WARN_ON(!wiphy)) 840 return NULL; 841 842 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 843 (signal < 0 || signal > 100))) 844 return NULL; 845 846 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable))) 847 return NULL; 848 849 privsz = wiphy->bss_priv_size; 850 851 res = kzalloc(sizeof(*res) + privsz + ielen, gfp); 852 if (!res) 853 return NULL; 854 855 memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN); 856 res->pub.channel = channel; 857 res->pub.signal = signal; 858 res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 859 res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); 860 res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); 861 /* 862 * The initial buffer for the IEs is allocated with the BSS entry and 863 * is located after the private area. 864 */ 865 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 866 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz; 867 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable, 868 ielen); 869 res->pub.len_proberesp_ies = ielen; 870 res->pub.information_elements = res->pub.proberesp_ies; 871 res->pub.len_information_elements = res->pub.len_proberesp_ies; 872 } else { 873 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz; 874 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen); 875 res->pub.len_beacon_ies = ielen; 876 res->pub.information_elements = res->pub.beacon_ies; 877 res->pub.len_information_elements = res->pub.len_beacon_ies; 878 } 879 880 kref_init(&res->ref); 881 882 res = cfg80211_bss_update(wiphy_to_dev(wiphy), res); 883 if (!res) 884 return NULL; 885 886 if (res->pub.capability & WLAN_CAPABILITY_ESS) 887 regulatory_hint_found_beacon(wiphy, channel, gfp); 888 889 /* cfg80211_bss_update gives us a referenced result */ 890 return &res->pub; 891} 892EXPORT_SYMBOL(cfg80211_inform_bss_frame); 893 894void cfg80211_ref_bss(struct cfg80211_bss *pub) 895{ 896 struct cfg80211_internal_bss *bss; 897 898 if (!pub) 899 return; 900 901 bss = container_of(pub, struct cfg80211_internal_bss, pub); 902 kref_get(&bss->ref); 903} 904EXPORT_SYMBOL(cfg80211_ref_bss); 905 906void cfg80211_put_bss(struct cfg80211_bss *pub) 907{ 908 struct cfg80211_internal_bss *bss; 909 910 if (!pub) 911 return; 912 913 bss = container_of(pub, struct cfg80211_internal_bss, pub); 914 kref_put(&bss->ref, bss_release); 915} 916EXPORT_SYMBOL(cfg80211_put_bss); 917 918void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 919{ 920 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); 921 struct cfg80211_internal_bss *bss; 922 923 if (WARN_ON(!pub)) 924 return; 925 926 bss = container_of(pub, struct cfg80211_internal_bss, pub); 927 928 spin_lock_bh(&dev->bss_lock); 929 if (!list_empty(&bss->list)) { 930 __cfg80211_unlink_bss(dev, bss); 931 dev->bss_generation++; 932 } 933 spin_unlock_bh(&dev->bss_lock); 934} 935EXPORT_SYMBOL(cfg80211_unlink_bss); 936 937#ifdef CONFIG_CFG80211_WEXT 938int cfg80211_wext_siwscan(struct net_device *dev, 939 struct iw_request_info *info, 940 union iwreq_data *wrqu, char *extra) 941{ 942 struct cfg80211_registered_device *rdev; 943 struct wiphy *wiphy; 944 struct iw_scan_req *wreq = NULL; 945 struct cfg80211_scan_request *creq = NULL; 946 int i, err, n_channels = 0; 947 enum ieee80211_band band; 948 949 if (!netif_running(dev)) 950 return -ENETDOWN; 951 952 if (wrqu->data.length == sizeof(struct iw_scan_req)) 953 wreq = (struct iw_scan_req *)extra; 954 955 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 956 957 if (IS_ERR(rdev)) 958 return PTR_ERR(rdev); 959 960 if (rdev->scan_req) { 961 err = -EBUSY; 962 goto out; 963 } 964 965 wiphy = &rdev->wiphy; 966 967 /* Determine number of channels, needed to allocate creq */ 968 if (wreq && wreq->num_channels) 969 n_channels = wreq->num_channels; 970 else { 971 for (band = 0; band < IEEE80211_NUM_BANDS; band++) 972 if (wiphy->bands[band]) 973 n_channels += wiphy->bands[band]->n_channels; 974 } 975 976 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + 977 n_channels * sizeof(void *), 978 GFP_ATOMIC); 979 if (!creq) { 980 err = -ENOMEM; 981 goto out; 982 } 983 984 creq->wiphy = wiphy; 985 creq->wdev = dev->ieee80211_ptr; 986 /* SSIDs come after channels */ 987 creq->ssids = (void *)&creq->channels[n_channels]; 988 creq->n_channels = n_channels; 989 creq->n_ssids = 1; 990 creq->scan_start = jiffies; 991 992 /* translate "Scan on frequencies" request */ 993 i = 0; 994 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 995 int j; 996 997 if (!wiphy->bands[band]) 998 continue; 999 1000 for (j = 0; j < wiphy->bands[band]->n_channels; j++) { 1001 /* ignore disabled channels */ 1002 if (wiphy->bands[band]->channels[j].flags & 1003 IEEE80211_CHAN_DISABLED) 1004 continue; 1005 1006 /* If we have a wireless request structure and the 1007 * wireless request specifies frequencies, then search 1008 * for the matching hardware channel. 1009 */ 1010 if (wreq && wreq->num_channels) { 1011 int k; 1012 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq; 1013 for (k = 0; k < wreq->num_channels; k++) { 1014 int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]); 1015 if (wext_freq == wiphy_freq) 1016 goto wext_freq_found; 1017 } 1018 goto wext_freq_not_found; 1019 } 1020 1021 wext_freq_found: 1022 creq->channels[i] = &wiphy->bands[band]->channels[j]; 1023 i++; 1024 wext_freq_not_found: ; 1025 } 1026 } 1027 /* No channels found? */ 1028 if (!i) { 1029 err = -EINVAL; 1030 goto out; 1031 } 1032 1033 /* Set real number of channels specified in creq->channels[] */ 1034 creq->n_channels = i; 1035 1036 /* translate "Scan for SSID" request */ 1037 if (wreq) { 1038 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) { 1039 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) { 1040 err = -EINVAL; 1041 goto out; 1042 } 1043 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); 1044 creq->ssids[0].ssid_len = wreq->essid_len; 1045 } 1046 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) 1047 creq->n_ssids = 0; 1048 } 1049 1050 for (i = 0; i < IEEE80211_NUM_BANDS; i++) 1051 if (wiphy->bands[i]) 1052 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; 1053 1054 rdev->scan_req = creq; 1055 err = rdev->ops->scan(wiphy, creq); 1056 if (err) { 1057 rdev->scan_req = NULL; 1058 /* creq will be freed below */ 1059 } else { 1060 nl80211_send_scan_start(rdev, dev->ieee80211_ptr); 1061 /* creq now owned by driver */ 1062 creq = NULL; 1063 dev_hold(dev); 1064 } 1065 out: 1066 kfree(creq); 1067 cfg80211_unlock_rdev(rdev); 1068 return err; 1069} 1070EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan); 1071 1072static void ieee80211_scan_add_ies(struct iw_request_info *info, 1073 struct cfg80211_bss *bss, 1074 char **current_ev, char *end_buf) 1075{ 1076 u8 *pos, *end, *next; 1077 struct iw_event iwe; 1078 1079 if (!bss->information_elements || 1080 !bss->len_information_elements) 1081 return; 1082 1083 /* 1084 * If needed, fragment the IEs buffer (at IE boundaries) into short 1085 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. 1086 */ 1087 pos = bss->information_elements; 1088 end = pos + bss->len_information_elements; 1089 1090 while (end - pos > IW_GENERIC_IE_MAX) { 1091 next = pos + 2 + pos[1]; 1092 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) 1093 next = next + 2 + next[1]; 1094 1095 memset(&iwe, 0, sizeof(iwe)); 1096 iwe.cmd = IWEVGENIE; 1097 iwe.u.data.length = next - pos; 1098 *current_ev = iwe_stream_add_point(info, *current_ev, 1099 end_buf, &iwe, pos); 1100 1101 pos = next; 1102 } 1103 1104 if (end > pos) { 1105 memset(&iwe, 0, sizeof(iwe)); 1106 iwe.cmd = IWEVGENIE; 1107 iwe.u.data.length = end - pos; 1108 *current_ev = iwe_stream_add_point(info, *current_ev, 1109 end_buf, &iwe, pos); 1110 } 1111} 1112 1113static inline unsigned int elapsed_jiffies_msecs(unsigned long start) 1114{ 1115 unsigned long end = jiffies; 1116 1117 if (end >= start) 1118 return jiffies_to_msecs(end - start); 1119 1120 return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1); 1121} 1122 1123static char * 1124ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, 1125 struct cfg80211_internal_bss *bss, char *current_ev, 1126 char *end_buf) 1127{ 1128 struct iw_event iwe; 1129 u8 *buf, *cfg, *p; 1130 u8 *ie = bss->pub.information_elements; 1131 int rem = bss->pub.len_information_elements, i, sig; 1132 bool ismesh = false; 1133 1134 memset(&iwe, 0, sizeof(iwe)); 1135 iwe.cmd = SIOCGIWAP; 1136 iwe.u.ap_addr.sa_family = ARPHRD_ETHER; 1137 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN); 1138 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, 1139 IW_EV_ADDR_LEN); 1140 1141 memset(&iwe, 0, sizeof(iwe)); 1142 iwe.cmd = SIOCGIWFREQ; 1143 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq); 1144 iwe.u.freq.e = 0; 1145 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, 1146 IW_EV_FREQ_LEN); 1147 1148 memset(&iwe, 0, sizeof(iwe)); 1149 iwe.cmd = SIOCGIWFREQ; 1150 iwe.u.freq.m = bss->pub.channel->center_freq; 1151 iwe.u.freq.e = 6; 1152 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, 1153 IW_EV_FREQ_LEN); 1154 1155 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) { 1156 memset(&iwe, 0, sizeof(iwe)); 1157 iwe.cmd = IWEVQUAL; 1158 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED | 1159 IW_QUAL_NOISE_INVALID | 1160 IW_QUAL_QUAL_UPDATED; 1161 switch (wiphy->signal_type) { 1162 case CFG80211_SIGNAL_TYPE_MBM: 1163 sig = bss->pub.signal / 100; 1164 iwe.u.qual.level = sig; 1165 iwe.u.qual.updated |= IW_QUAL_DBM; 1166 if (sig < -110) /* rather bad */ 1167 sig = -110; 1168 else if (sig > -40) /* perfect */ 1169 sig = -40; 1170 /* will give a range of 0 .. 70 */ 1171 iwe.u.qual.qual = sig + 110; 1172 break; 1173 case CFG80211_SIGNAL_TYPE_UNSPEC: 1174 iwe.u.qual.level = bss->pub.signal; 1175 /* will give range 0 .. 100 */ 1176 iwe.u.qual.qual = bss->pub.signal; 1177 break; 1178 default: 1179 /* not reached */ 1180 break; 1181 } 1182 current_ev = iwe_stream_add_event(info, current_ev, end_buf, 1183 &iwe, IW_EV_QUAL_LEN); 1184 } 1185 1186 memset(&iwe, 0, sizeof(iwe)); 1187 iwe.cmd = SIOCGIWENCODE; 1188 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY) 1189 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; 1190 else 1191 iwe.u.data.flags = IW_ENCODE_DISABLED; 1192 iwe.u.data.length = 0; 1193 current_ev = iwe_stream_add_point(info, current_ev, end_buf, 1194 &iwe, ""); 1195 1196 while (rem >= 2) { 1197 /* invalid data */ 1198 if (ie[1] > rem - 2) 1199 break; 1200 1201 switch (ie[0]) { 1202 case WLAN_EID_SSID: 1203 memset(&iwe, 0, sizeof(iwe)); 1204 iwe.cmd = SIOCGIWESSID; 1205 iwe.u.data.length = ie[1]; 1206 iwe.u.data.flags = 1; 1207 current_ev = iwe_stream_add_point(info, current_ev, end_buf, 1208 &iwe, ie + 2); 1209 break; 1210 case WLAN_EID_MESH_ID: 1211 memset(&iwe, 0, sizeof(iwe)); 1212 iwe.cmd = SIOCGIWESSID; 1213 iwe.u.data.length = ie[1]; 1214 iwe.u.data.flags = 1; 1215 current_ev = iwe_stream_add_point(info, current_ev, end_buf, 1216 &iwe, ie + 2); 1217 break; 1218 case WLAN_EID_MESH_CONFIG: 1219 ismesh = true; 1220 if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) 1221 break; 1222 buf = kmalloc(50, GFP_ATOMIC); 1223 if (!buf) 1224 break; 1225 cfg = ie + 2; 1226 memset(&iwe, 0, sizeof(iwe)); 1227 iwe.cmd = IWEVCUSTOM; 1228 sprintf(buf, "Mesh Network Path Selection Protocol ID: " 1229 "0x%02X", cfg[0]); 1230 iwe.u.data.length = strlen(buf); 1231 current_ev = iwe_stream_add_point(info, current_ev, 1232 end_buf, 1233 &iwe, buf); 1234 sprintf(buf, "Path Selection Metric ID: 0x%02X", 1235 cfg[1]); 1236 iwe.u.data.length = strlen(buf); 1237 current_ev = iwe_stream_add_point(info, current_ev, 1238 end_buf, 1239 &iwe, buf); 1240 sprintf(buf, "Congestion Control Mode ID: 0x%02X", 1241 cfg[2]); 1242 iwe.u.data.length = strlen(buf); 1243 current_ev = iwe_stream_add_point(info, current_ev, 1244 end_buf, 1245 &iwe, buf); 1246 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]); 1247 iwe.u.data.length = strlen(buf); 1248 current_ev = iwe_stream_add_point(info, current_ev, 1249 end_buf, 1250 &iwe, buf); 1251 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]); 1252 iwe.u.data.length = strlen(buf); 1253 current_ev = iwe_stream_add_point(info, current_ev, 1254 end_buf, 1255 &iwe, buf); 1256 sprintf(buf, "Formation Info: 0x%02X", cfg[5]); 1257 iwe.u.data.length = strlen(buf); 1258 current_ev = iwe_stream_add_point(info, current_ev, 1259 end_buf, 1260 &iwe, buf); 1261 sprintf(buf, "Capabilities: 0x%02X", cfg[6]); 1262 iwe.u.data.length = strlen(buf); 1263 current_ev = iwe_stream_add_point(info, current_ev, 1264 end_buf, 1265 &iwe, buf); 1266 kfree(buf); 1267 break; 1268 case WLAN_EID_SUPP_RATES: 1269 case WLAN_EID_EXT_SUPP_RATES: 1270 /* display all supported rates in readable format */ 1271 p = current_ev + iwe_stream_lcp_len(info); 1272 1273 memset(&iwe, 0, sizeof(iwe)); 1274 iwe.cmd = SIOCGIWRATE; 1275 /* Those two flags are ignored... */ 1276 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; 1277 1278 for (i = 0; i < ie[1]; i++) { 1279 iwe.u.bitrate.value = 1280 ((ie[i + 2] & 0x7f) * 500000); 1281 p = iwe_stream_add_value(info, current_ev, p, 1282 end_buf, &iwe, IW_EV_PARAM_LEN); 1283 } 1284 current_ev = p; 1285 break; 1286 } 1287 rem -= ie[1] + 2; 1288 ie += ie[1] + 2; 1289 } 1290 1291 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) || 1292 ismesh) { 1293 memset(&iwe, 0, sizeof(iwe)); 1294 iwe.cmd = SIOCGIWMODE; 1295 if (ismesh) 1296 iwe.u.mode = IW_MODE_MESH; 1297 else if (bss->pub.capability & WLAN_CAPABILITY_ESS) 1298 iwe.u.mode = IW_MODE_MASTER; 1299 else 1300 iwe.u.mode = IW_MODE_ADHOC; 1301 current_ev = iwe_stream_add_event(info, current_ev, end_buf, 1302 &iwe, IW_EV_UINT_LEN); 1303 } 1304 1305 buf = kmalloc(30, GFP_ATOMIC); 1306 if (buf) { 1307 memset(&iwe, 0, sizeof(iwe)); 1308 iwe.cmd = IWEVCUSTOM; 1309 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf)); 1310 iwe.u.data.length = strlen(buf); 1311 current_ev = iwe_stream_add_point(info, current_ev, end_buf, 1312 &iwe, buf); 1313 memset(&iwe, 0, sizeof(iwe)); 1314 iwe.cmd = IWEVCUSTOM; 1315 sprintf(buf, " Last beacon: %ums ago", 1316 elapsed_jiffies_msecs(bss->ts)); 1317 iwe.u.data.length = strlen(buf); 1318 current_ev = iwe_stream_add_point(info, current_ev, 1319 end_buf, &iwe, buf); 1320 kfree(buf); 1321 } 1322 1323 ieee80211_scan_add_ies(info, &bss->pub, ¤t_ev, end_buf); 1324 1325 return current_ev; 1326} 1327 1328 1329static int ieee80211_scan_results(struct cfg80211_registered_device *dev, 1330 struct iw_request_info *info, 1331 char *buf, size_t len) 1332{ 1333 char *current_ev = buf; 1334 char *end_buf = buf + len; 1335 struct cfg80211_internal_bss *bss; 1336 1337 spin_lock_bh(&dev->bss_lock); 1338 cfg80211_bss_expire(dev); 1339 1340 list_for_each_entry(bss, &dev->bss_list, list) { 1341 if (buf + len - current_ev <= IW_EV_ADDR_LEN) { 1342 spin_unlock_bh(&dev->bss_lock); 1343 return -E2BIG; 1344 } 1345 current_ev = ieee80211_bss(&dev->wiphy, info, bss, 1346 current_ev, end_buf); 1347 } 1348 spin_unlock_bh(&dev->bss_lock); 1349 return current_ev - buf; 1350} 1351 1352 1353int cfg80211_wext_giwscan(struct net_device *dev, 1354 struct iw_request_info *info, 1355 struct iw_point *data, char *extra) 1356{ 1357 struct cfg80211_registered_device *rdev; 1358 int res; 1359 1360 if (!netif_running(dev)) 1361 return -ENETDOWN; 1362 1363 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 1364 1365 if (IS_ERR(rdev)) 1366 return PTR_ERR(rdev); 1367 1368 if (rdev->scan_req) { 1369 res = -EAGAIN; 1370 goto out; 1371 } 1372 1373 res = ieee80211_scan_results(rdev, info, extra, data->length); 1374 data->length = 0; 1375 if (res >= 0) { 1376 data->length = res; 1377 res = 0; 1378 } 1379 1380 out: 1381 cfg80211_unlock_rdev(rdev); 1382 return res; 1383} 1384EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan); 1385#endif 1386