1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * cfg80211 scan result handling 4 * 5 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net> 6 * Copyright 2013-2014 Intel Mobile Communications GmbH 7 * Copyright 2016 Intel Deutschland GmbH 8 * Copyright (C) 2018-2019 Intel Corporation 9 */ 10 #include <linux/kernel.h> 11 #include <linux/slab.h> 12 #include <linux/module.h> 13 #include <linux/netdevice.h> 14 #include <linux/wireless.h> 15 #include <linux/nl80211.h> 16 #include <linux/etherdevice.h> 17 #include <net/arp.h> 18 #include <net/cfg80211.h> 19 #include <net/cfg80211-wext.h> 20 #include <net/iw_handler.h> 21 #include "core.h" 22 #include "nl80211.h" 23 #include "wext-compat.h" 24 #include "rdev-ops.h" 25 26 /** 27 * DOC: BSS tree/list structure 28 * 29 * At the top level, the BSS list is kept in both a list in each 30 * registered device (@bss_list) as well as an RB-tree for faster 31 * lookup. In the RB-tree, entries can be looked up using their 32 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID 33 * for other BSSes. 34 * 35 * Due to the possibility of hidden SSIDs, there's a second level 36 * structure, the "hidden_list" and "hidden_beacon_bss" pointer. 37 * The hidden_list connects all BSSes belonging to a single AP 38 * that has a hidden SSID, and connects beacon and probe response 39 * entries. For a probe response entry for a hidden SSID, the 40 * hidden_beacon_bss pointer points to the BSS struct holding the 41 * beacon's information. 42 * 43 * Reference counting is done for all these references except for 44 * the hidden_list, so that a beacon BSS struct that is otherwise 45 * not referenced has one reference for being on the bss_list and 46 * one for each probe response entry that points to it using the 47 * hidden_beacon_bss pointer. When a BSS struct that has such a 48 * pointer is get/put, the refcount update is also propagated to 49 * the referenced struct, this ensure that it cannot get removed 50 * while somebody is using the probe response version. 51 * 52 * Note that the hidden_beacon_bss pointer never changes, due to 53 * the reference counting. Therefore, no locking is needed for 54 * it. 55 * 56 * Also note that the hidden_beacon_bss pointer is only relevant 57 * if the driver uses something other than the IEs, e.g. private 58 * data stored stored in the BSS struct, since the beacon IEs are 59 * also linked into the probe response struct. 60 */ 61 62 /* 63 * Limit the number of BSS entries stored in mac80211. Each one is 64 * a bit over 4k at most, so this limits to roughly 4-5M of memory. 65 * If somebody wants to really attack this though, they'd likely 66 * use small beacons, and only one type of frame, limiting each of 67 * the entries to a much smaller size (in order to generate more 68 * entries in total, so overhead is bigger.) 69 */ 70 static int bss_entries_limit = 1000; 71 module_param(bss_entries_limit, int, 0644); 72 MODULE_PARM_DESC(bss_entries_limit, 73 "limit to number of scan BSS entries (per wiphy, default 1000)"); 74 75 #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) 76 77 static void bss_free(struct cfg80211_internal_bss *bss) 78 { 79 struct cfg80211_bss_ies *ies; 80 81 if (WARN_ON(atomic_read(&bss->hold))) 82 return; 83 84 ies = (void *)rcu_access_pointer(bss->pub.beacon_ies); 85 if (ies && !bss->pub.hidden_beacon_bss) 86 kfree_rcu(ies, rcu_head); 87 ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies); 88 if (ies) 89 kfree_rcu(ies, rcu_head); 90 91 /* 92 * This happens when the module is removed, it doesn't 93 * really matter any more save for completeness 94 */ 95 if (!list_empty(&bss->hidden_list)) 96 list_del(&bss->hidden_list); 97 98 kfree(bss); 99 } 100 101 static inline void bss_ref_get(struct cfg80211_registered_device *rdev, 102 struct cfg80211_internal_bss *bss) 103 { 104 lockdep_assert_held(&rdev->bss_lock); 105 106 bss->refcount++; 107 if (bss->pub.hidden_beacon_bss) { 108 bss = container_of(bss->pub.hidden_beacon_bss, 109 struct cfg80211_internal_bss, 110 pub); 111 bss->refcount++; 112 } 113 if (bss->pub.transmitted_bss) { 114 bss = container_of(bss->pub.transmitted_bss, 115 struct cfg80211_internal_bss, 116 pub); 117 bss->refcount++; 118 } 119 } 120 121 static inline void bss_ref_put(struct cfg80211_registered_device *rdev, 122 struct cfg80211_internal_bss *bss) 123 { 124 lockdep_assert_held(&rdev->bss_lock); 125 126 if (bss->pub.hidden_beacon_bss) { 127 struct cfg80211_internal_bss *hbss; 128 hbss = container_of(bss->pub.hidden_beacon_bss, 129 struct cfg80211_internal_bss, 130 pub); 131 hbss->refcount--; 132 if (hbss->refcount == 0) 133 bss_free(hbss); 134 } 135 136 if (bss->pub.transmitted_bss) { 137 struct cfg80211_internal_bss *tbss; 138 139 tbss = container_of(bss->pub.transmitted_bss, 140 struct cfg80211_internal_bss, 141 pub); 142 tbss->refcount--; 143 if (tbss->refcount == 0) 144 bss_free(tbss); 145 } 146 147 bss->refcount--; 148 if (bss->refcount == 0) 149 bss_free(bss); 150 } 151 152 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, 153 struct cfg80211_internal_bss *bss) 154 { 155 lockdep_assert_held(&rdev->bss_lock); 156 157 if (!list_empty(&bss->hidden_list)) { 158 /* 159 * don't remove the beacon entry if it has 160 * probe responses associated with it 161 */ 162 if (!bss->pub.hidden_beacon_bss) 163 return false; 164 /* 165 * if it's a probe response entry break its 166 * link to the other entries in the group 167 */ 168 list_del_init(&bss->hidden_list); 169 } 170 171 list_del_init(&bss->list); 172 list_del_init(&bss->pub.nontrans_list); 173 rb_erase(&bss->rbn, &rdev->bss_tree); 174 rdev->bss_entries--; 175 WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list), 176 "rdev bss entries[%d]/list[empty:%d] corruption\n", 177 rdev->bss_entries, list_empty(&rdev->bss_list)); 178 bss_ref_put(rdev, bss); 179 return true; 180 } 181 182 bool cfg80211_is_element_inherited(const struct element *elem, 183 const struct element *non_inherit_elem) 184 { 185 u8 id_len, ext_id_len, i, loop_len, id; 186 const u8 *list; 187 188 if (elem->id == WLAN_EID_MULTIPLE_BSSID) 189 return false; 190 191 if (!non_inherit_elem || non_inherit_elem->datalen < 2) 192 return true; 193 194 /* 195 * non inheritance element format is: 196 * ext ID (56) | IDs list len | list | extension IDs list len | list 197 * Both lists are optional. Both lengths are mandatory. 198 * This means valid length is: 199 * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths 200 */ 201 id_len = non_inherit_elem->data[1]; 202 if (non_inherit_elem->datalen < 3 + id_len) 203 return true; 204 205 ext_id_len = non_inherit_elem->data[2 + id_len]; 206 if (non_inherit_elem->datalen < 3 + id_len + ext_id_len) 207 return true; 208 209 if (elem->id == WLAN_EID_EXTENSION) { 210 if (!ext_id_len) 211 return true; 212 loop_len = ext_id_len; 213 list = &non_inherit_elem->data[3 + id_len]; 214 id = elem->data[0]; 215 } else { 216 if (!id_len) 217 return true; 218 loop_len = id_len; 219 list = &non_inherit_elem->data[2]; 220 id = elem->id; 221 } 222 223 for (i = 0; i < loop_len; i++) { 224 if (list[i] == id) 225 return false; 226 } 227 228 return true; 229 } 230 EXPORT_SYMBOL(cfg80211_is_element_inherited); 231 232 static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, 233 const u8 *subelement, size_t subie_len, 234 u8 *new_ie, gfp_t gfp) 235 { 236 u8 *pos, *tmp; 237 const u8 *tmp_old, *tmp_new; 238 const struct element *non_inherit_elem; 239 u8 *sub_copy; 240 241 /* copy subelement as we need to change its content to 242 * mark an ie after it is processed. 243 */ 244 sub_copy = kmemdup(subelement, subie_len, gfp); 245 if (!sub_copy) 246 return 0; 247 248 pos = &new_ie[0]; 249 250 /* set new ssid */ 251 tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len); 252 if (tmp_new) { 253 memcpy(pos, tmp_new, tmp_new[1] + 2); 254 pos += (tmp_new[1] + 2); 255 } 256 257 /* get non inheritance list if exists */ 258 non_inherit_elem = 259 cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, 260 sub_copy, subie_len); 261 262 /* go through IEs in ie (skip SSID) and subelement, 263 * merge them into new_ie 264 */ 265 tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); 266 tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie; 267 268 while (tmp_old + tmp_old[1] + 2 - ie <= ielen) { 269 if (tmp_old[0] == 0) { 270 tmp_old++; 271 continue; 272 } 273 274 if (tmp_old[0] == WLAN_EID_EXTENSION) 275 tmp = (u8 *)cfg80211_find_ext_ie(tmp_old[2], sub_copy, 276 subie_len); 277 else 278 tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy, 279 subie_len); 280 281 if (!tmp) { 282 const struct element *old_elem = (void *)tmp_old; 283 284 /* ie in old ie but not in subelement */ 285 if (cfg80211_is_element_inherited(old_elem, 286 non_inherit_elem)) { 287 memcpy(pos, tmp_old, tmp_old[1] + 2); 288 pos += tmp_old[1] + 2; 289 } 290 } else { 291 /* ie in transmitting ie also in subelement, 292 * copy from subelement and flag the ie in subelement 293 * as copied (by setting eid field to WLAN_EID_SSID, 294 * which is skipped anyway). 295 * For vendor ie, compare OUI + type + subType to 296 * determine if they are the same ie. 297 */ 298 if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) { 299 if (!memcmp(tmp_old + 2, tmp + 2, 5)) { 300 /* same vendor ie, copy from 301 * subelement 302 */ 303 memcpy(pos, tmp, tmp[1] + 2); 304 pos += tmp[1] + 2; 305 tmp[0] = WLAN_EID_SSID; 306 } else { 307 memcpy(pos, tmp_old, tmp_old[1] + 2); 308 pos += tmp_old[1] + 2; 309 } 310 } else { 311 /* copy ie from subelement into new ie */ 312 memcpy(pos, tmp, tmp[1] + 2); 313 pos += tmp[1] + 2; 314 tmp[0] = WLAN_EID_SSID; 315 } 316 } 317 318 if (tmp_old + tmp_old[1] + 2 - ie == ielen) 319 break; 320 321 tmp_old += tmp_old[1] + 2; 322 } 323 324 /* go through subelement again to check if there is any ie not 325 * copied to new ie, skip ssid, capability, bssid-index ie 326 */ 327 tmp_new = sub_copy; 328 while (tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) { 329 if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP || 330 tmp_new[0] == WLAN_EID_SSID)) { 331 memcpy(pos, tmp_new, tmp_new[1] + 2); 332 pos += tmp_new[1] + 2; 333 } 334 if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len) 335 break; 336 tmp_new += tmp_new[1] + 2; 337 } 338 339 kfree(sub_copy); 340 return pos - new_ie; 341 } 342 343 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, 344 const u8 *ssid, size_t ssid_len) 345 { 346 const struct cfg80211_bss_ies *ies; 347 const u8 *ssidie; 348 349 if (bssid && !ether_addr_equal(a->bssid, bssid)) 350 return false; 351 352 if (!ssid) 353 return true; 354 355 ies = rcu_access_pointer(a->ies); 356 if (!ies) 357 return false; 358 ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 359 if (!ssidie) 360 return false; 361 if (ssidie[1] != ssid_len) 362 return false; 363 return memcmp(ssidie + 2, ssid, ssid_len) == 0; 364 } 365 366 static int 367 cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss, 368 struct cfg80211_bss *nontrans_bss) 369 { 370 const u8 *ssid; 371 size_t ssid_len; 372 struct cfg80211_bss *bss = NULL; 373 374 rcu_read_lock(); 375 ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); 376 if (!ssid) { 377 rcu_read_unlock(); 378 return -EINVAL; 379 } 380 ssid_len = ssid[1]; 381 ssid = ssid + 2; 382 rcu_read_unlock(); 383 384 /* check if nontrans_bss is in the list */ 385 list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) { 386 if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) 387 return 0; 388 } 389 390 /* add to the list */ 391 list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); 392 return 0; 393 } 394 395 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, 396 unsigned long expire_time) 397 { 398 struct cfg80211_internal_bss *bss, *tmp; 399 bool expired = false; 400 401 lockdep_assert_held(&rdev->bss_lock); 402 403 list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) { 404 if (atomic_read(&bss->hold)) 405 continue; 406 if (!time_after(expire_time, bss->ts)) 407 continue; 408 409 if (__cfg80211_unlink_bss(rdev, bss)) 410 expired = true; 411 } 412 413 if (expired) 414 rdev->bss_generation++; 415 } 416 417 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) 418 { 419 struct cfg80211_internal_bss *bss, *oldest = NULL; 420 bool ret; 421 422 lockdep_assert_held(&rdev->bss_lock); 423 424 list_for_each_entry(bss, &rdev->bss_list, list) { 425 if (atomic_read(&bss->hold)) 426 continue; 427 428 if (!list_empty(&bss->hidden_list) && 429 !bss->pub.hidden_beacon_bss) 430 continue; 431 432 if (oldest && time_before(oldest->ts, bss->ts)) 433 continue; 434 oldest = bss; 435 } 436 437 if (WARN_ON(!oldest)) 438 return false; 439 440 /* 441 * The callers make sure to increase rdev->bss_generation if anything 442 * gets removed (and a new entry added), so there's no need to also do 443 * it here. 444 */ 445 446 ret = __cfg80211_unlink_bss(rdev, oldest); 447 WARN_ON(!ret); 448 return ret; 449 } 450 451 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, 452 bool send_message) 453 { 454 struct cfg80211_scan_request *request; 455 struct wireless_dev *wdev; 456 struct sk_buff *msg; 457 #ifdef CONFIG_CFG80211_WEXT 458 union iwreq_data wrqu; 459 #endif 460 461 ASSERT_RTNL(); 462 463 if (rdev->scan_msg) { 464 nl80211_send_scan_msg(rdev, rdev->scan_msg); 465 rdev->scan_msg = NULL; 466 return; 467 } 468 469 request = rdev->scan_req; 470 if (!request) 471 return; 472 473 wdev = request->wdev; 474 475 /* 476 * This must be before sending the other events! 477 * Otherwise, wpa_supplicant gets completely confused with 478 * wext events. 479 */ 480 if (wdev->netdev) 481 cfg80211_sme_scan_done(wdev->netdev); 482 483 if (!request->info.aborted && 484 request->flags & NL80211_SCAN_FLAG_FLUSH) { 485 /* flush entries from previous scans */ 486 spin_lock_bh(&rdev->bss_lock); 487 __cfg80211_bss_expire(rdev, request->scan_start); 488 spin_unlock_bh(&rdev->bss_lock); 489 } 490 491 msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted); 492 493 #ifdef CONFIG_CFG80211_WEXT 494 if (wdev->netdev && !request->info.aborted) { 495 memset(&wrqu, 0, sizeof(wrqu)); 496 497 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL); 498 } 499 #endif 500 501 if (wdev->netdev) 502 dev_put(wdev->netdev); 503 504 rdev->scan_req = NULL; 505 kfree(request); 506 507 if (!send_message) 508 rdev->scan_msg = msg; 509 else 510 nl80211_send_scan_msg(rdev, msg); 511 } 512 513 void __cfg80211_scan_done(struct work_struct *wk) 514 { 515 struct cfg80211_registered_device *rdev; 516 517 rdev = container_of(wk, struct cfg80211_registered_device, 518 scan_done_wk); 519 520 rtnl_lock(); 521 ___cfg80211_scan_done(rdev, true); 522 rtnl_unlock(); 523 } 524 525 void cfg80211_scan_done(struct cfg80211_scan_request *request, 526 struct cfg80211_scan_info *info) 527 { 528 trace_cfg80211_scan_done(request, info); 529 WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req); 530 531 request->info = *info; 532 request->notified = true; 533 queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk); 534 } 535 EXPORT_SYMBOL(cfg80211_scan_done); 536 537 void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev, 538 struct cfg80211_sched_scan_request *req) 539 { 540 ASSERT_RTNL(); 541 542 list_add_rcu(&req->list, &rdev->sched_scan_req_list); 543 } 544 545 static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev, 546 struct cfg80211_sched_scan_request *req) 547 { 548 ASSERT_RTNL(); 549 550 list_del_rcu(&req->list); 551 kfree_rcu(req, rcu_head); 552 } 553 554 static struct cfg80211_sched_scan_request * 555 cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid) 556 { 557 struct cfg80211_sched_scan_request *pos; 558 559 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); 560 561 list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) { 562 if (pos->reqid == reqid) 563 return pos; 564 } 565 return NULL; 566 } 567 568 /* 569 * Determines if a scheduled scan request can be handled. When a legacy 570 * scheduled scan is running no other scheduled scan is allowed regardless 571 * whether the request is for legacy or multi-support scan. When a multi-support 572 * scheduled scan is running a request for legacy scan is not allowed. In this 573 * case a request for multi-support scan can be handled if resources are 574 * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached. 575 */ 576 int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev, 577 bool want_multi) 578 { 579 struct cfg80211_sched_scan_request *pos; 580 int i = 0; 581 582 list_for_each_entry(pos, &rdev->sched_scan_req_list, list) { 583 /* request id zero means legacy in progress */ 584 if (!i && !pos->reqid) 585 return -EINPROGRESS; 586 i++; 587 } 588 589 if (i) { 590 /* no legacy allowed when multi request(s) are active */ 591 if (!want_multi) 592 return -EINPROGRESS; 593 594 /* resource limit reached */ 595 if (i == rdev->wiphy.max_sched_scan_reqs) 596 return -ENOSPC; 597 } 598 return 0; 599 } 600 601 void cfg80211_sched_scan_results_wk(struct work_struct *work) 602 { 603 struct cfg80211_registered_device *rdev; 604 struct cfg80211_sched_scan_request *req, *tmp; 605 606 rdev = container_of(work, struct cfg80211_registered_device, 607 sched_scan_res_wk); 608 609 rtnl_lock(); 610 list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) { 611 if (req->report_results) { 612 req->report_results = false; 613 if (req->flags & NL80211_SCAN_FLAG_FLUSH) { 614 /* flush entries from previous scans */ 615 spin_lock_bh(&rdev->bss_lock); 616 __cfg80211_bss_expire(rdev, req->scan_start); 617 spin_unlock_bh(&rdev->bss_lock); 618 req->scan_start = jiffies; 619 } 620 nl80211_send_sched_scan(req, 621 NL80211_CMD_SCHED_SCAN_RESULTS); 622 } 623 } 624 rtnl_unlock(); 625 } 626 627 void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid) 628 { 629 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 630 struct cfg80211_sched_scan_request *request; 631 632 trace_cfg80211_sched_scan_results(wiphy, reqid); 633 /* ignore if we're not scanning */ 634 635 rcu_read_lock(); 636 request = cfg80211_find_sched_scan_req(rdev, reqid); 637 if (request) { 638 request->report_results = true; 639 queue_work(cfg80211_wq, &rdev->sched_scan_res_wk); 640 } 641 rcu_read_unlock(); 642 } 643 EXPORT_SYMBOL(cfg80211_sched_scan_results); 644 645 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy, u64 reqid) 646 { 647 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 648 649 ASSERT_RTNL(); 650 651 trace_cfg80211_sched_scan_stopped(wiphy, reqid); 652 653 __cfg80211_stop_sched_scan(rdev, reqid, true); 654 } 655 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl); 656 657 void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid) 658 { 659 rtnl_lock(); 660 cfg80211_sched_scan_stopped_rtnl(wiphy, reqid); 661 rtnl_unlock(); 662 } 663 EXPORT_SYMBOL(cfg80211_sched_scan_stopped); 664 665 int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev, 666 struct cfg80211_sched_scan_request *req, 667 bool driver_initiated) 668 { 669 ASSERT_RTNL(); 670 671 if (!driver_initiated) { 672 int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid); 673 if (err) 674 return err; 675 } 676 677 nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED); 678 679 cfg80211_del_sched_scan_req(rdev, req); 680 681 return 0; 682 } 683 684 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, 685 u64 reqid, bool driver_initiated) 686 { 687 struct cfg80211_sched_scan_request *sched_scan_req; 688 689 ASSERT_RTNL(); 690 691 sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid); 692 if (!sched_scan_req) 693 return -ENOENT; 694 695 return cfg80211_stop_sched_scan_req(rdev, sched_scan_req, 696 driver_initiated); 697 } 698 699 void cfg80211_bss_age(struct cfg80211_registered_device *rdev, 700 unsigned long age_secs) 701 { 702 struct cfg80211_internal_bss *bss; 703 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); 704 705 spin_lock_bh(&rdev->bss_lock); 706 list_for_each_entry(bss, &rdev->bss_list, list) 707 bss->ts -= age_jiffies; 708 spin_unlock_bh(&rdev->bss_lock); 709 } 710 711 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev) 712 { 713 __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); 714 } 715 716 const struct element * 717 cfg80211_find_elem_match(u8 eid, const u8 *ies, unsigned int len, 718 const u8 *match, unsigned int match_len, 719 unsigned int match_offset) 720 { 721 const struct element *elem; 722 723 for_each_element_id(elem, eid, ies, len) { 724 if (elem->datalen >= match_offset + match_len && 725 !memcmp(elem->data + match_offset, match, match_len)) 726 return elem; 727 } 728 729 return NULL; 730 } 731 EXPORT_SYMBOL(cfg80211_find_elem_match); 732 733 const struct element *cfg80211_find_vendor_elem(unsigned int oui, int oui_type, 734 const u8 *ies, 735 unsigned int len) 736 { 737 const struct element *elem; 738 u8 match[] = { oui >> 16, oui >> 8, oui, oui_type }; 739 int match_len = (oui_type < 0) ? 3 : sizeof(match); 740 741 if (WARN_ON(oui_type > 0xff)) 742 return NULL; 743 744 elem = cfg80211_find_elem_match(WLAN_EID_VENDOR_SPECIFIC, ies, len, 745 match, match_len, 0); 746 747 if (!elem || elem->datalen < 4) 748 return NULL; 749 750 return elem; 751 } 752 EXPORT_SYMBOL(cfg80211_find_vendor_elem); 753 754 /** 755 * enum bss_compare_mode - BSS compare mode 756 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) 757 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode 758 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode 759 */ 760 enum bss_compare_mode { 761 BSS_CMP_REGULAR, 762 BSS_CMP_HIDE_ZLEN, 763 BSS_CMP_HIDE_NUL, 764 }; 765 766 static int cmp_bss(struct cfg80211_bss *a, 767 struct cfg80211_bss *b, 768 enum bss_compare_mode mode) 769 { 770 const struct cfg80211_bss_ies *a_ies, *b_ies; 771 const u8 *ie1 = NULL; 772 const u8 *ie2 = NULL; 773 int i, r; 774 775 if (a->channel != b->channel) 776 return b->channel->center_freq - a->channel->center_freq; 777 778 a_ies = rcu_access_pointer(a->ies); 779 if (!a_ies) 780 return -1; 781 b_ies = rcu_access_pointer(b->ies); 782 if (!b_ies) 783 return 1; 784 785 if (WLAN_CAPABILITY_IS_STA_BSS(a->capability)) 786 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID, 787 a_ies->data, a_ies->len); 788 if (WLAN_CAPABILITY_IS_STA_BSS(b->capability)) 789 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID, 790 b_ies->data, b_ies->len); 791 if (ie1 && ie2) { 792 int mesh_id_cmp; 793 794 if (ie1[1] == ie2[1]) 795 mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]); 796 else 797 mesh_id_cmp = ie2[1] - ie1[1]; 798 799 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 800 a_ies->data, a_ies->len); 801 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 802 b_ies->data, b_ies->len); 803 if (ie1 && ie2) { 804 if (mesh_id_cmp) 805 return mesh_id_cmp; 806 if (ie1[1] != ie2[1]) 807 return ie2[1] - ie1[1]; 808 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 809 } 810 } 811 812 r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); 813 if (r) 814 return r; 815 816 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len); 817 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len); 818 819 if (!ie1 && !ie2) 820 return 0; 821 822 /* 823 * Note that with "hide_ssid", the function returns a match if 824 * the already-present BSS ("b") is a hidden SSID beacon for 825 * the new BSS ("a"). 826 */ 827 828 /* sort missing IE before (left of) present IE */ 829 if (!ie1) 830 return -1; 831 if (!ie2) 832 return 1; 833 834 switch (mode) { 835 case BSS_CMP_HIDE_ZLEN: 836 /* 837 * In ZLEN mode we assume the BSS entry we're 838 * looking for has a zero-length SSID. So if 839 * the one we're looking at right now has that, 840 * return 0. Otherwise, return the difference 841 * in length, but since we're looking for the 842 * 0-length it's really equivalent to returning 843 * the length of the one we're looking at. 844 * 845 * No content comparison is needed as we assume 846 * the content length is zero. 847 */ 848 return ie2[1]; 849 case BSS_CMP_REGULAR: 850 default: 851 /* sort by length first, then by contents */ 852 if (ie1[1] != ie2[1]) 853 return ie2[1] - ie1[1]; 854 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 855 case BSS_CMP_HIDE_NUL: 856 if (ie1[1] != ie2[1]) 857 return ie2[1] - ie1[1]; 858 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */ 859 for (i = 0; i < ie2[1]; i++) 860 if (ie2[i + 2]) 861 return -1; 862 return 0; 863 } 864 } 865 866 static bool cfg80211_bss_type_match(u16 capability, 867 enum nl80211_band band, 868 enum ieee80211_bss_type bss_type) 869 { 870 bool ret = true; 871 u16 mask, val; 872 873 if (bss_type == IEEE80211_BSS_TYPE_ANY) 874 return ret; 875 876 if (band == NL80211_BAND_60GHZ) { 877 mask = WLAN_CAPABILITY_DMG_TYPE_MASK; 878 switch (bss_type) { 879 case IEEE80211_BSS_TYPE_ESS: 880 val = WLAN_CAPABILITY_DMG_TYPE_AP; 881 break; 882 case IEEE80211_BSS_TYPE_PBSS: 883 val = WLAN_CAPABILITY_DMG_TYPE_PBSS; 884 break; 885 case IEEE80211_BSS_TYPE_IBSS: 886 val = WLAN_CAPABILITY_DMG_TYPE_IBSS; 887 break; 888 default: 889 return false; 890 } 891 } else { 892 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS; 893 switch (bss_type) { 894 case IEEE80211_BSS_TYPE_ESS: 895 val = WLAN_CAPABILITY_ESS; 896 break; 897 case IEEE80211_BSS_TYPE_IBSS: 898 val = WLAN_CAPABILITY_IBSS; 899 break; 900 case IEEE80211_BSS_TYPE_MBSS: 901 val = 0; 902 break; 903 default: 904 return false; 905 } 906 } 907 908 ret = ((capability & mask) == val); 909 return ret; 910 } 911 912 /* Returned bss is reference counted and must be cleaned up appropriately. */ 913 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, 914 struct ieee80211_channel *channel, 915 const u8 *bssid, 916 const u8 *ssid, size_t ssid_len, 917 enum ieee80211_bss_type bss_type, 918 enum ieee80211_privacy privacy) 919 { 920 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 921 struct cfg80211_internal_bss *bss, *res = NULL; 922 unsigned long now = jiffies; 923 int bss_privacy; 924 925 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type, 926 privacy); 927 928 spin_lock_bh(&rdev->bss_lock); 929 930 list_for_each_entry(bss, &rdev->bss_list, list) { 931 if (!cfg80211_bss_type_match(bss->pub.capability, 932 bss->pub.channel->band, bss_type)) 933 continue; 934 935 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY); 936 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) || 937 (privacy == IEEE80211_PRIVACY_OFF && bss_privacy)) 938 continue; 939 if (channel && bss->pub.channel != channel) 940 continue; 941 if (!is_valid_ether_addr(bss->pub.bssid)) 942 continue; 943 /* Don't get expired BSS structs */ 944 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && 945 !atomic_read(&bss->hold)) 946 continue; 947 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { 948 res = bss; 949 bss_ref_get(rdev, res); 950 break; 951 } 952 } 953 954 spin_unlock_bh(&rdev->bss_lock); 955 if (!res) 956 return NULL; 957 trace_cfg80211_return_bss(&res->pub); 958 return &res->pub; 959 } 960 EXPORT_SYMBOL(cfg80211_get_bss); 961 962 static void rb_insert_bss(struct cfg80211_registered_device *rdev, 963 struct cfg80211_internal_bss *bss) 964 { 965 struct rb_node **p = &rdev->bss_tree.rb_node; 966 struct rb_node *parent = NULL; 967 struct cfg80211_internal_bss *tbss; 968 int cmp; 969 970 while (*p) { 971 parent = *p; 972 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); 973 974 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR); 975 976 if (WARN_ON(!cmp)) { 977 /* will sort of leak this BSS */ 978 return; 979 } 980 981 if (cmp < 0) 982 p = &(*p)->rb_left; 983 else 984 p = &(*p)->rb_right; 985 } 986 987 rb_link_node(&bss->rbn, parent, p); 988 rb_insert_color(&bss->rbn, &rdev->bss_tree); 989 } 990 991 static struct cfg80211_internal_bss * 992 rb_find_bss(struct cfg80211_registered_device *rdev, 993 struct cfg80211_internal_bss *res, 994 enum bss_compare_mode mode) 995 { 996 struct rb_node *n = rdev->bss_tree.rb_node; 997 struct cfg80211_internal_bss *bss; 998 int r; 999 1000 while (n) { 1001 bss = rb_entry(n, struct cfg80211_internal_bss, rbn); 1002 r = cmp_bss(&res->pub, &bss->pub, mode); 1003 1004 if (r == 0) 1005 return bss; 1006 else if (r < 0) 1007 n = n->rb_left; 1008 else 1009 n = n->rb_right; 1010 } 1011 1012 return NULL; 1013 } 1014 1015 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, 1016 struct cfg80211_internal_bss *new) 1017 { 1018 const struct cfg80211_bss_ies *ies; 1019 struct cfg80211_internal_bss *bss; 1020 const u8 *ie; 1021 int i, ssidlen; 1022 u8 fold = 0; 1023 u32 n_entries = 0; 1024 1025 ies = rcu_access_pointer(new->pub.beacon_ies); 1026 if (WARN_ON(!ies)) 1027 return false; 1028 1029 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 1030 if (!ie) { 1031 /* nothing to do */ 1032 return true; 1033 } 1034 1035 ssidlen = ie[1]; 1036 for (i = 0; i < ssidlen; i++) 1037 fold |= ie[2 + i]; 1038 1039 if (fold) { 1040 /* not a hidden SSID */ 1041 return true; 1042 } 1043 1044 /* This is the bad part ... */ 1045 1046 list_for_each_entry(bss, &rdev->bss_list, list) { 1047 /* 1048 * we're iterating all the entries anyway, so take the 1049 * opportunity to validate the list length accounting 1050 */ 1051 n_entries++; 1052 1053 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) 1054 continue; 1055 if (bss->pub.channel != new->pub.channel) 1056 continue; 1057 if (bss->pub.scan_width != new->pub.scan_width) 1058 continue; 1059 if (rcu_access_pointer(bss->pub.beacon_ies)) 1060 continue; 1061 ies = rcu_access_pointer(bss->pub.ies); 1062 if (!ies) 1063 continue; 1064 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 1065 if (!ie) 1066 continue; 1067 if (ssidlen && ie[1] != ssidlen) 1068 continue; 1069 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss)) 1070 continue; 1071 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list))) 1072 list_del(&bss->hidden_list); 1073 /* combine them */ 1074 list_add(&bss->hidden_list, &new->hidden_list); 1075 bss->pub.hidden_beacon_bss = &new->pub; 1076 new->refcount += bss->refcount; 1077 rcu_assign_pointer(bss->pub.beacon_ies, 1078 new->pub.beacon_ies); 1079 } 1080 1081 WARN_ONCE(n_entries != rdev->bss_entries, 1082 "rdev bss entries[%d]/list[len:%d] corruption\n", 1083 rdev->bss_entries, n_entries); 1084 1085 return true; 1086 } 1087 1088 struct cfg80211_non_tx_bss { 1089 struct cfg80211_bss *tx_bss; 1090 u8 max_bssid_indicator; 1091 u8 bssid_index; 1092 }; 1093 1094 static bool 1095 cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, 1096 struct cfg80211_internal_bss *known, 1097 struct cfg80211_internal_bss *new, 1098 bool signal_valid) 1099 { 1100 lockdep_assert_held(&rdev->bss_lock); 1101 1102 /* Update IEs */ 1103 if (rcu_access_pointer(new->pub.proberesp_ies)) { 1104 const struct cfg80211_bss_ies *old; 1105 1106 old = rcu_access_pointer(known->pub.proberesp_ies); 1107 1108 rcu_assign_pointer(known->pub.proberesp_ies, 1109 new->pub.proberesp_ies); 1110 /* Override possible earlier Beacon frame IEs */ 1111 rcu_assign_pointer(known->pub.ies, 1112 new->pub.proberesp_ies); 1113 if (old) 1114 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1115 } else if (rcu_access_pointer(new->pub.beacon_ies)) { 1116 const struct cfg80211_bss_ies *old; 1117 struct cfg80211_internal_bss *bss; 1118 1119 if (known->pub.hidden_beacon_bss && 1120 !list_empty(&known->hidden_list)) { 1121 const struct cfg80211_bss_ies *f; 1122 1123 /* The known BSS struct is one of the probe 1124 * response members of a group, but we're 1125 * receiving a beacon (beacon_ies in the new 1126 * bss is used). This can only mean that the 1127 * AP changed its beacon from not having an 1128 * SSID to showing it, which is confusing so 1129 * drop this information. 1130 */ 1131 1132 f = rcu_access_pointer(new->pub.beacon_ies); 1133 kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head); 1134 return false; 1135 } 1136 1137 old = rcu_access_pointer(known->pub.beacon_ies); 1138 1139 rcu_assign_pointer(known->pub.beacon_ies, new->pub.beacon_ies); 1140 1141 /* Override IEs if they were from a beacon before */ 1142 if (old == rcu_access_pointer(known->pub.ies)) 1143 rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies); 1144 1145 /* Assign beacon IEs to all sub entries */ 1146 list_for_each_entry(bss, &known->hidden_list, hidden_list) { 1147 const struct cfg80211_bss_ies *ies; 1148 1149 ies = rcu_access_pointer(bss->pub.beacon_ies); 1150 WARN_ON(ies != old); 1151 1152 rcu_assign_pointer(bss->pub.beacon_ies, 1153 new->pub.beacon_ies); 1154 } 1155 1156 if (old) 1157 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1158 } 1159 1160 known->pub.beacon_interval = new->pub.beacon_interval; 1161 1162 /* don't update the signal if beacon was heard on 1163 * adjacent channel. 1164 */ 1165 if (signal_valid) 1166 known->pub.signal = new->pub.signal; 1167 known->pub.capability = new->pub.capability; 1168 known->ts = new->ts; 1169 known->ts_boottime = new->ts_boottime; 1170 known->parent_tsf = new->parent_tsf; 1171 known->pub.chains = new->pub.chains; 1172 memcpy(known->pub.chain_signal, new->pub.chain_signal, 1173 IEEE80211_MAX_CHAINS); 1174 ether_addr_copy(known->parent_bssid, new->parent_bssid); 1175 known->pub.max_bssid_indicator = new->pub.max_bssid_indicator; 1176 known->pub.bssid_index = new->pub.bssid_index; 1177 1178 return true; 1179 } 1180 1181 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1182 struct cfg80211_internal_bss * 1183 cfg80211_bss_update(struct cfg80211_registered_device *rdev, 1184 struct cfg80211_internal_bss *tmp, 1185 bool signal_valid, unsigned long ts) 1186 { 1187 struct cfg80211_internal_bss *found = NULL; 1188 1189 if (WARN_ON(!tmp->pub.channel)) 1190 return NULL; 1191 1192 tmp->ts = ts; 1193 1194 spin_lock_bh(&rdev->bss_lock); 1195 1196 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) { 1197 spin_unlock_bh(&rdev->bss_lock); 1198 return NULL; 1199 } 1200 1201 found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR); 1202 1203 if (found) { 1204 if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid)) 1205 goto drop; 1206 } else { 1207 struct cfg80211_internal_bss *new; 1208 struct cfg80211_internal_bss *hidden; 1209 struct cfg80211_bss_ies *ies; 1210 1211 /* 1212 * create a copy -- the "res" variable that is passed in 1213 * is allocated on the stack since it's not needed in the 1214 * more common case of an update 1215 */ 1216 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size, 1217 GFP_ATOMIC); 1218 if (!new) { 1219 ies = (void *)rcu_dereference(tmp->pub.beacon_ies); 1220 if (ies) 1221 kfree_rcu(ies, rcu_head); 1222 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies); 1223 if (ies) 1224 kfree_rcu(ies, rcu_head); 1225 goto drop; 1226 } 1227 memcpy(new, tmp, sizeof(*new)); 1228 new->refcount = 1; 1229 INIT_LIST_HEAD(&new->hidden_list); 1230 INIT_LIST_HEAD(&new->pub.nontrans_list); 1231 1232 if (rcu_access_pointer(tmp->pub.proberesp_ies)) { 1233 hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); 1234 if (!hidden) 1235 hidden = rb_find_bss(rdev, tmp, 1236 BSS_CMP_HIDE_NUL); 1237 if (hidden) { 1238 new->pub.hidden_beacon_bss = &hidden->pub; 1239 list_add(&new->hidden_list, 1240 &hidden->hidden_list); 1241 hidden->refcount++; 1242 rcu_assign_pointer(new->pub.beacon_ies, 1243 hidden->pub.beacon_ies); 1244 } 1245 } else { 1246 /* 1247 * Ok so we found a beacon, and don't have an entry. If 1248 * it's a beacon with hidden SSID, we might be in for an 1249 * expensive search for any probe responses that should 1250 * be grouped with this beacon for updates ... 1251 */ 1252 if (!cfg80211_combine_bsses(rdev, new)) { 1253 kfree(new); 1254 goto drop; 1255 } 1256 } 1257 1258 if (rdev->bss_entries >= bss_entries_limit && 1259 !cfg80211_bss_expire_oldest(rdev)) { 1260 kfree(new); 1261 goto drop; 1262 } 1263 1264 /* This must be before the call to bss_ref_get */ 1265 if (tmp->pub.transmitted_bss) { 1266 struct cfg80211_internal_bss *pbss = 1267 container_of(tmp->pub.transmitted_bss, 1268 struct cfg80211_internal_bss, 1269 pub); 1270 1271 new->pub.transmitted_bss = tmp->pub.transmitted_bss; 1272 bss_ref_get(rdev, pbss); 1273 } 1274 1275 list_add_tail(&new->list, &rdev->bss_list); 1276 rdev->bss_entries++; 1277 rb_insert_bss(rdev, new); 1278 found = new; 1279 } 1280 1281 rdev->bss_generation++; 1282 bss_ref_get(rdev, found); 1283 spin_unlock_bh(&rdev->bss_lock); 1284 1285 return found; 1286 drop: 1287 spin_unlock_bh(&rdev->bss_lock); 1288 return NULL; 1289 } 1290 1291 /* 1292 * Update RX channel information based on the available frame payload 1293 * information. This is mainly for the 2.4 GHz band where frames can be received 1294 * from neighboring channels and the Beacon frames use the DSSS Parameter Set 1295 * element to indicate the current (transmitting) channel, but this might also 1296 * be needed on other bands if RX frequency does not match with the actual 1297 * operating channel of a BSS. 1298 */ 1299 static struct ieee80211_channel * 1300 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, 1301 struct ieee80211_channel *channel, 1302 enum nl80211_bss_scan_width scan_width) 1303 { 1304 const u8 *tmp; 1305 u32 freq; 1306 int channel_number = -1; 1307 struct ieee80211_channel *alt_channel; 1308 1309 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen); 1310 if (tmp && tmp[1] == 1) { 1311 channel_number = tmp[2]; 1312 } else { 1313 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen); 1314 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) { 1315 struct ieee80211_ht_operation *htop = (void *)(tmp + 2); 1316 1317 channel_number = htop->primary_chan; 1318 } 1319 } 1320 1321 if (channel_number < 0) { 1322 /* No channel information in frame payload */ 1323 return channel; 1324 } 1325 1326 freq = ieee80211_channel_to_frequency(channel_number, channel->band); 1327 alt_channel = ieee80211_get_channel(wiphy, freq); 1328 if (!alt_channel) { 1329 if (channel->band == NL80211_BAND_2GHZ) { 1330 /* 1331 * Better not allow unexpected channels when that could 1332 * be going beyond the 1-11 range (e.g., discovering 1333 * BSS on channel 12 when radio is configured for 1334 * channel 11. 1335 */ 1336 return NULL; 1337 } 1338 1339 /* No match for the payload channel number - ignore it */ 1340 return channel; 1341 } 1342 1343 if (scan_width == NL80211_BSS_CHAN_WIDTH_10 || 1344 scan_width == NL80211_BSS_CHAN_WIDTH_5) { 1345 /* 1346 * Ignore channel number in 5 and 10 MHz channels where there 1347 * may not be an n:1 or 1:n mapping between frequencies and 1348 * channel numbers. 1349 */ 1350 return channel; 1351 } 1352 1353 /* 1354 * Use the channel determined through the payload channel number 1355 * instead of the RX channel reported by the driver. 1356 */ 1357 if (alt_channel->flags & IEEE80211_CHAN_DISABLED) 1358 return NULL; 1359 return alt_channel; 1360 } 1361 1362 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1363 static struct cfg80211_bss * 1364 cfg80211_inform_single_bss_data(struct wiphy *wiphy, 1365 struct cfg80211_inform_bss *data, 1366 enum cfg80211_bss_frame_type ftype, 1367 const u8 *bssid, u64 tsf, u16 capability, 1368 u16 beacon_interval, const u8 *ie, size_t ielen, 1369 struct cfg80211_non_tx_bss *non_tx_data, 1370 gfp_t gfp) 1371 { 1372 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1373 struct cfg80211_bss_ies *ies; 1374 struct ieee80211_channel *channel; 1375 struct cfg80211_internal_bss tmp = {}, *res; 1376 int bss_type; 1377 bool signal_valid; 1378 unsigned long ts; 1379 1380 if (WARN_ON(!wiphy)) 1381 return NULL; 1382 1383 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 1384 (data->signal < 0 || data->signal > 100))) 1385 return NULL; 1386 1387 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan, 1388 data->scan_width); 1389 if (!channel) 1390 return NULL; 1391 1392 memcpy(tmp.pub.bssid, bssid, ETH_ALEN); 1393 tmp.pub.channel = channel; 1394 tmp.pub.scan_width = data->scan_width; 1395 tmp.pub.signal = data->signal; 1396 tmp.pub.beacon_interval = beacon_interval; 1397 tmp.pub.capability = capability; 1398 tmp.ts_boottime = data->boottime_ns; 1399 if (non_tx_data) { 1400 tmp.pub.transmitted_bss = non_tx_data->tx_bss; 1401 ts = bss_from_pub(non_tx_data->tx_bss)->ts; 1402 tmp.pub.bssid_index = non_tx_data->bssid_index; 1403 tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; 1404 } else { 1405 ts = jiffies; 1406 } 1407 1408 /* 1409 * If we do not know here whether the IEs are from a Beacon or Probe 1410 * Response frame, we need to pick one of the options and only use it 1411 * with the driver that does not provide the full Beacon/Probe Response 1412 * frame. Use Beacon frame pointer to avoid indicating that this should 1413 * override the IEs pointer should we have received an earlier 1414 * indication of Probe Response data. 1415 */ 1416 ies = kzalloc(sizeof(*ies) + ielen, gfp); 1417 if (!ies) 1418 return NULL; 1419 ies->len = ielen; 1420 ies->tsf = tsf; 1421 ies->from_beacon = false; 1422 memcpy(ies->data, ie, ielen); 1423 1424 switch (ftype) { 1425 case CFG80211_BSS_FTYPE_BEACON: 1426 ies->from_beacon = true; 1427 /* fall through */ 1428 case CFG80211_BSS_FTYPE_UNKNOWN: 1429 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 1430 break; 1431 case CFG80211_BSS_FTYPE_PRESP: 1432 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 1433 break; 1434 } 1435 rcu_assign_pointer(tmp.pub.ies, ies); 1436 1437 signal_valid = abs(data->chan->center_freq - channel->center_freq) <= 1438 wiphy->max_adj_channel_rssi_comp; 1439 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts); 1440 if (!res) 1441 return NULL; 1442 1443 if (channel->band == NL80211_BAND_60GHZ) { 1444 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 1445 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 1446 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 1447 regulatory_hint_found_beacon(wiphy, channel, gfp); 1448 } else { 1449 if (res->pub.capability & WLAN_CAPABILITY_ESS) 1450 regulatory_hint_found_beacon(wiphy, channel, gfp); 1451 } 1452 1453 if (non_tx_data) { 1454 /* this is a nontransmitting bss, we need to add it to 1455 * transmitting bss' list if it is not there 1456 */ 1457 if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, 1458 &res->pub)) { 1459 if (__cfg80211_unlink_bss(rdev, res)) 1460 rdev->bss_generation++; 1461 } 1462 } 1463 1464 trace_cfg80211_return_bss(&res->pub); 1465 /* cfg80211_bss_update gives us a referenced result */ 1466 return &res->pub; 1467 } 1468 1469 static const struct element 1470 *cfg80211_get_profile_continuation(const u8 *ie, size_t ielen, 1471 const struct element *mbssid_elem, 1472 const struct element *sub_elem) 1473 { 1474 const u8 *mbssid_end = mbssid_elem->data + mbssid_elem->datalen; 1475 const struct element *next_mbssid; 1476 const struct element *next_sub; 1477 1478 next_mbssid = cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID, 1479 mbssid_end, 1480 ielen - (mbssid_end - ie)); 1481 1482 /* 1483 * If is is not the last subelement in current MBSSID IE or there isn't 1484 * a next MBSSID IE - profile is complete. 1485 */ 1486 if ((sub_elem->data + sub_elem->datalen < mbssid_end - 1) || 1487 !next_mbssid) 1488 return NULL; 1489 1490 /* For any length error, just return NULL */ 1491 1492 if (next_mbssid->datalen < 4) 1493 return NULL; 1494 1495 next_sub = (void *)&next_mbssid->data[1]; 1496 1497 if (next_mbssid->data + next_mbssid->datalen < 1498 next_sub->data + next_sub->datalen) 1499 return NULL; 1500 1501 if (next_sub->id != 0 || next_sub->datalen < 2) 1502 return NULL; 1503 1504 /* 1505 * Check if the first element in the next sub element is a start 1506 * of a new profile 1507 */ 1508 return next_sub->data[0] == WLAN_EID_NON_TX_BSSID_CAP ? 1509 NULL : next_mbssid; 1510 } 1511 1512 size_t cfg80211_merge_profile(const u8 *ie, size_t ielen, 1513 const struct element *mbssid_elem, 1514 const struct element *sub_elem, 1515 u8 *merged_ie, size_t max_copy_len) 1516 { 1517 size_t copied_len = sub_elem->datalen; 1518 const struct element *next_mbssid; 1519 1520 if (sub_elem->datalen > max_copy_len) 1521 return 0; 1522 1523 memcpy(merged_ie, sub_elem->data, sub_elem->datalen); 1524 1525 while ((next_mbssid = cfg80211_get_profile_continuation(ie, ielen, 1526 mbssid_elem, 1527 sub_elem))) { 1528 const struct element *next_sub = (void *)&next_mbssid->data[1]; 1529 1530 if (copied_len + next_sub->datalen > max_copy_len) 1531 break; 1532 memcpy(merged_ie + copied_len, next_sub->data, 1533 next_sub->datalen); 1534 copied_len += next_sub->datalen; 1535 } 1536 1537 return copied_len; 1538 } 1539 EXPORT_SYMBOL(cfg80211_merge_profile); 1540 1541 static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, 1542 struct cfg80211_inform_bss *data, 1543 enum cfg80211_bss_frame_type ftype, 1544 const u8 *bssid, u64 tsf, 1545 u16 beacon_interval, const u8 *ie, 1546 size_t ielen, 1547 struct cfg80211_non_tx_bss *non_tx_data, 1548 gfp_t gfp) 1549 { 1550 const u8 *mbssid_index_ie; 1551 const struct element *elem, *sub; 1552 size_t new_ie_len; 1553 u8 new_bssid[ETH_ALEN]; 1554 u8 *new_ie, *profile; 1555 u64 seen_indices = 0; 1556 u16 capability; 1557 struct cfg80211_bss *bss; 1558 1559 if (!non_tx_data) 1560 return; 1561 if (!cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) 1562 return; 1563 if (!wiphy->support_mbssid) 1564 return; 1565 if (wiphy->support_only_he_mbssid && 1566 !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) 1567 return; 1568 1569 new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp); 1570 if (!new_ie) 1571 return; 1572 1573 profile = kmalloc(ielen, gfp); 1574 if (!profile) 1575 goto out; 1576 1577 for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) { 1578 if (elem->datalen < 4) 1579 continue; 1580 for_each_element(sub, elem->data + 1, elem->datalen - 1) { 1581 u8 profile_len; 1582 1583 if (sub->id != 0 || sub->datalen < 4) { 1584 /* not a valid BSS profile */ 1585 continue; 1586 } 1587 1588 if (sub->data[0] != WLAN_EID_NON_TX_BSSID_CAP || 1589 sub->data[1] != 2) { 1590 /* The first element within the Nontransmitted 1591 * BSSID Profile is not the Nontransmitted 1592 * BSSID Capability element. 1593 */ 1594 continue; 1595 } 1596 1597 memset(profile, 0, ielen); 1598 profile_len = cfg80211_merge_profile(ie, ielen, 1599 elem, 1600 sub, 1601 profile, 1602 ielen); 1603 1604 /* found a Nontransmitted BSSID Profile */ 1605 mbssid_index_ie = cfg80211_find_ie 1606 (WLAN_EID_MULTI_BSSID_IDX, 1607 profile, profile_len); 1608 if (!mbssid_index_ie || mbssid_index_ie[1] < 1 || 1609 mbssid_index_ie[2] == 0 || 1610 mbssid_index_ie[2] > 46) { 1611 /* No valid Multiple BSSID-Index element */ 1612 continue; 1613 } 1614 1615 if (seen_indices & BIT_ULL(mbssid_index_ie[2])) 1616 /* We don't support legacy split of a profile */ 1617 net_dbg_ratelimited("Partial info for BSSID index %d\n", 1618 mbssid_index_ie[2]); 1619 1620 seen_indices |= BIT_ULL(mbssid_index_ie[2]); 1621 1622 non_tx_data->bssid_index = mbssid_index_ie[2]; 1623 non_tx_data->max_bssid_indicator = elem->data[0]; 1624 1625 cfg80211_gen_new_bssid(bssid, 1626 non_tx_data->max_bssid_indicator, 1627 non_tx_data->bssid_index, 1628 new_bssid); 1629 memset(new_ie, 0, IEEE80211_MAX_DATA_LEN); 1630 new_ie_len = cfg80211_gen_new_ie(ie, ielen, 1631 profile, 1632 profile_len, new_ie, 1633 gfp); 1634 if (!new_ie_len) 1635 continue; 1636 1637 capability = get_unaligned_le16(profile + 2); 1638 bss = cfg80211_inform_single_bss_data(wiphy, data, 1639 ftype, 1640 new_bssid, tsf, 1641 capability, 1642 beacon_interval, 1643 new_ie, 1644 new_ie_len, 1645 non_tx_data, 1646 gfp); 1647 if (!bss) 1648 break; 1649 cfg80211_put_bss(wiphy, bss); 1650 } 1651 } 1652 1653 out: 1654 kfree(new_ie); 1655 kfree(profile); 1656 } 1657 1658 struct cfg80211_bss * 1659 cfg80211_inform_bss_data(struct wiphy *wiphy, 1660 struct cfg80211_inform_bss *data, 1661 enum cfg80211_bss_frame_type ftype, 1662 const u8 *bssid, u64 tsf, u16 capability, 1663 u16 beacon_interval, const u8 *ie, size_t ielen, 1664 gfp_t gfp) 1665 { 1666 struct cfg80211_bss *res; 1667 struct cfg80211_non_tx_bss non_tx_data; 1668 1669 res = cfg80211_inform_single_bss_data(wiphy, data, ftype, bssid, tsf, 1670 capability, beacon_interval, ie, 1671 ielen, NULL, gfp); 1672 if (!res) 1673 return NULL; 1674 non_tx_data.tx_bss = res; 1675 cfg80211_parse_mbssid_data(wiphy, data, ftype, bssid, tsf, 1676 beacon_interval, ie, ielen, &non_tx_data, 1677 gfp); 1678 return res; 1679 } 1680 EXPORT_SYMBOL(cfg80211_inform_bss_data); 1681 1682 static void 1683 cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy, 1684 struct cfg80211_inform_bss *data, 1685 struct ieee80211_mgmt *mgmt, size_t len, 1686 struct cfg80211_non_tx_bss *non_tx_data, 1687 gfp_t gfp) 1688 { 1689 enum cfg80211_bss_frame_type ftype; 1690 const u8 *ie = mgmt->u.probe_resp.variable; 1691 size_t ielen = len - offsetof(struct ieee80211_mgmt, 1692 u.probe_resp.variable); 1693 1694 ftype = ieee80211_is_beacon(mgmt->frame_control) ? 1695 CFG80211_BSS_FTYPE_BEACON : CFG80211_BSS_FTYPE_PRESP; 1696 1697 cfg80211_parse_mbssid_data(wiphy, data, ftype, mgmt->bssid, 1698 le64_to_cpu(mgmt->u.probe_resp.timestamp), 1699 le16_to_cpu(mgmt->u.probe_resp.beacon_int), 1700 ie, ielen, non_tx_data, gfp); 1701 } 1702 1703 static void 1704 cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, 1705 struct cfg80211_bss *nontrans_bss, 1706 struct ieee80211_mgmt *mgmt, size_t len) 1707 { 1708 u8 *ie, *new_ie, *pos; 1709 const u8 *nontrans_ssid, *trans_ssid, *mbssid; 1710 size_t ielen = len - offsetof(struct ieee80211_mgmt, 1711 u.probe_resp.variable); 1712 size_t new_ie_len; 1713 struct cfg80211_bss_ies *new_ies; 1714 const struct cfg80211_bss_ies *old; 1715 u8 cpy_len; 1716 1717 lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock); 1718 1719 ie = mgmt->u.probe_resp.variable; 1720 1721 new_ie_len = ielen; 1722 trans_ssid = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); 1723 if (!trans_ssid) 1724 return; 1725 new_ie_len -= trans_ssid[1]; 1726 mbssid = cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen); 1727 /* 1728 * It's not valid to have the MBSSID element before SSID 1729 * ignore if that happens - the code below assumes it is 1730 * after (while copying things inbetween). 1731 */ 1732 if (!mbssid || mbssid < trans_ssid) 1733 return; 1734 new_ie_len -= mbssid[1]; 1735 1736 nontrans_ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); 1737 if (!nontrans_ssid) 1738 return; 1739 1740 new_ie_len += nontrans_ssid[1]; 1741 1742 /* generate new ie for nontrans BSS 1743 * 1. replace SSID with nontrans BSS' SSID 1744 * 2. skip MBSSID IE 1745 */ 1746 new_ie = kzalloc(new_ie_len, GFP_ATOMIC); 1747 if (!new_ie) 1748 return; 1749 1750 new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC); 1751 if (!new_ies) 1752 goto out_free; 1753 1754 pos = new_ie; 1755 1756 /* copy the nontransmitted SSID */ 1757 cpy_len = nontrans_ssid[1] + 2; 1758 memcpy(pos, nontrans_ssid, cpy_len); 1759 pos += cpy_len; 1760 /* copy the IEs between SSID and MBSSID */ 1761 cpy_len = trans_ssid[1] + 2; 1762 memcpy(pos, (trans_ssid + cpy_len), (mbssid - (trans_ssid + cpy_len))); 1763 pos += (mbssid - (trans_ssid + cpy_len)); 1764 /* copy the IEs after MBSSID */ 1765 cpy_len = mbssid[1] + 2; 1766 memcpy(pos, mbssid + cpy_len, ((ie + ielen) - (mbssid + cpy_len))); 1767 1768 /* update ie */ 1769 new_ies->len = new_ie_len; 1770 new_ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 1771 new_ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); 1772 memcpy(new_ies->data, new_ie, new_ie_len); 1773 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 1774 old = rcu_access_pointer(nontrans_bss->proberesp_ies); 1775 rcu_assign_pointer(nontrans_bss->proberesp_ies, new_ies); 1776 rcu_assign_pointer(nontrans_bss->ies, new_ies); 1777 if (old) 1778 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1779 } else { 1780 old = rcu_access_pointer(nontrans_bss->beacon_ies); 1781 rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies); 1782 rcu_assign_pointer(nontrans_bss->ies, new_ies); 1783 if (old) 1784 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1785 } 1786 1787 out_free: 1788 kfree(new_ie); 1789 } 1790 1791 /* cfg80211_inform_bss_width_frame helper */ 1792 static struct cfg80211_bss * 1793 cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, 1794 struct cfg80211_inform_bss *data, 1795 struct ieee80211_mgmt *mgmt, size_t len, 1796 gfp_t gfp) 1797 { 1798 struct cfg80211_internal_bss tmp = {}, *res; 1799 struct cfg80211_bss_ies *ies; 1800 struct ieee80211_channel *channel; 1801 bool signal_valid; 1802 size_t ielen = len - offsetof(struct ieee80211_mgmt, 1803 u.probe_resp.variable); 1804 int bss_type; 1805 1806 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) != 1807 offsetof(struct ieee80211_mgmt, u.beacon.variable)); 1808 1809 trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len); 1810 1811 if (WARN_ON(!mgmt)) 1812 return NULL; 1813 1814 if (WARN_ON(!wiphy)) 1815 return NULL; 1816 1817 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 1818 (data->signal < 0 || data->signal > 100))) 1819 return NULL; 1820 1821 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable))) 1822 return NULL; 1823 1824 channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable, 1825 ielen, data->chan, data->scan_width); 1826 if (!channel) 1827 return NULL; 1828 1829 ies = kzalloc(sizeof(*ies) + ielen, gfp); 1830 if (!ies) 1831 return NULL; 1832 ies->len = ielen; 1833 ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 1834 ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); 1835 memcpy(ies->data, mgmt->u.probe_resp.variable, ielen); 1836 1837 if (ieee80211_is_probe_resp(mgmt->frame_control)) 1838 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 1839 else 1840 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 1841 rcu_assign_pointer(tmp.pub.ies, ies); 1842 1843 memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN); 1844 tmp.pub.channel = channel; 1845 tmp.pub.scan_width = data->scan_width; 1846 tmp.pub.signal = data->signal; 1847 tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); 1848 tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); 1849 tmp.ts_boottime = data->boottime_ns; 1850 tmp.parent_tsf = data->parent_tsf; 1851 tmp.pub.chains = data->chains; 1852 memcpy(tmp.pub.chain_signal, data->chain_signal, IEEE80211_MAX_CHAINS); 1853 ether_addr_copy(tmp.parent_bssid, data->parent_bssid); 1854 1855 signal_valid = abs(data->chan->center_freq - channel->center_freq) <= 1856 wiphy->max_adj_channel_rssi_comp; 1857 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, 1858 jiffies); 1859 if (!res) 1860 return NULL; 1861 1862 if (channel->band == NL80211_BAND_60GHZ) { 1863 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 1864 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 1865 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 1866 regulatory_hint_found_beacon(wiphy, channel, gfp); 1867 } else { 1868 if (res->pub.capability & WLAN_CAPABILITY_ESS) 1869 regulatory_hint_found_beacon(wiphy, channel, gfp); 1870 } 1871 1872 trace_cfg80211_return_bss(&res->pub); 1873 /* cfg80211_bss_update gives us a referenced result */ 1874 return &res->pub; 1875 } 1876 1877 struct cfg80211_bss * 1878 cfg80211_inform_bss_frame_data(struct wiphy *wiphy, 1879 struct cfg80211_inform_bss *data, 1880 struct ieee80211_mgmt *mgmt, size_t len, 1881 gfp_t gfp) 1882 { 1883 struct cfg80211_bss *res, *tmp_bss; 1884 const u8 *ie = mgmt->u.probe_resp.variable; 1885 const struct cfg80211_bss_ies *ies1, *ies2; 1886 size_t ielen = len - offsetof(struct ieee80211_mgmt, 1887 u.probe_resp.variable); 1888 struct cfg80211_non_tx_bss non_tx_data; 1889 1890 res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt, 1891 len, gfp); 1892 if (!res || !wiphy->support_mbssid || 1893 !cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) 1894 return res; 1895 if (wiphy->support_only_he_mbssid && 1896 !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) 1897 return res; 1898 1899 non_tx_data.tx_bss = res; 1900 /* process each non-transmitting bss */ 1901 cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len, 1902 &non_tx_data, gfp); 1903 1904 spin_lock_bh(&wiphy_to_rdev(wiphy)->bss_lock); 1905 1906 /* check if the res has other nontransmitting bss which is not 1907 * in MBSSID IE 1908 */ 1909 ies1 = rcu_access_pointer(res->ies); 1910 1911 /* go through nontrans_list, if the timestamp of the BSS is 1912 * earlier than the timestamp of the transmitting BSS then 1913 * update it 1914 */ 1915 list_for_each_entry(tmp_bss, &res->nontrans_list, 1916 nontrans_list) { 1917 ies2 = rcu_access_pointer(tmp_bss->ies); 1918 if (ies2->tsf < ies1->tsf) 1919 cfg80211_update_notlisted_nontrans(wiphy, tmp_bss, 1920 mgmt, len); 1921 } 1922 spin_unlock_bh(&wiphy_to_rdev(wiphy)->bss_lock); 1923 1924 return res; 1925 } 1926 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data); 1927 1928 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1929 { 1930 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1931 struct cfg80211_internal_bss *bss; 1932 1933 if (!pub) 1934 return; 1935 1936 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1937 1938 spin_lock_bh(&rdev->bss_lock); 1939 bss_ref_get(rdev, bss); 1940 spin_unlock_bh(&rdev->bss_lock); 1941 } 1942 EXPORT_SYMBOL(cfg80211_ref_bss); 1943 1944 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1945 { 1946 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1947 struct cfg80211_internal_bss *bss; 1948 1949 if (!pub) 1950 return; 1951 1952 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1953 1954 spin_lock_bh(&rdev->bss_lock); 1955 bss_ref_put(rdev, bss); 1956 spin_unlock_bh(&rdev->bss_lock); 1957 } 1958 EXPORT_SYMBOL(cfg80211_put_bss); 1959 1960 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1961 { 1962 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1963 struct cfg80211_internal_bss *bss, *tmp1; 1964 struct cfg80211_bss *nontrans_bss, *tmp; 1965 1966 if (WARN_ON(!pub)) 1967 return; 1968 1969 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1970 1971 spin_lock_bh(&rdev->bss_lock); 1972 if (list_empty(&bss->list)) 1973 goto out; 1974 1975 list_for_each_entry_safe(nontrans_bss, tmp, 1976 &pub->nontrans_list, 1977 nontrans_list) { 1978 tmp1 = container_of(nontrans_bss, 1979 struct cfg80211_internal_bss, pub); 1980 if (__cfg80211_unlink_bss(rdev, tmp1)) 1981 rdev->bss_generation++; 1982 } 1983 1984 if (__cfg80211_unlink_bss(rdev, bss)) 1985 rdev->bss_generation++; 1986 out: 1987 spin_unlock_bh(&rdev->bss_lock); 1988 } 1989 EXPORT_SYMBOL(cfg80211_unlink_bss); 1990 1991 void cfg80211_bss_iter(struct wiphy *wiphy, 1992 struct cfg80211_chan_def *chandef, 1993 void (*iter)(struct wiphy *wiphy, 1994 struct cfg80211_bss *bss, 1995 void *data), 1996 void *iter_data) 1997 { 1998 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1999 struct cfg80211_internal_bss *bss; 2000 2001 spin_lock_bh(&rdev->bss_lock); 2002 2003 list_for_each_entry(bss, &rdev->bss_list, list) { 2004 if (!chandef || cfg80211_is_sub_chan(chandef, bss->pub.channel)) 2005 iter(wiphy, &bss->pub, iter_data); 2006 } 2007 2008 spin_unlock_bh(&rdev->bss_lock); 2009 } 2010 EXPORT_SYMBOL(cfg80211_bss_iter); 2011 2012 void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev, 2013 struct ieee80211_channel *chan) 2014 { 2015 struct wiphy *wiphy = wdev->wiphy; 2016 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2017 struct cfg80211_internal_bss *cbss = wdev->current_bss; 2018 struct cfg80211_internal_bss *new = NULL; 2019 struct cfg80211_internal_bss *bss; 2020 struct cfg80211_bss *nontrans_bss; 2021 struct cfg80211_bss *tmp; 2022 2023 spin_lock_bh(&rdev->bss_lock); 2024 2025 if (WARN_ON(cbss->pub.channel == chan)) 2026 goto done; 2027 2028 /* use transmitting bss */ 2029 if (cbss->pub.transmitted_bss) 2030 cbss = container_of(cbss->pub.transmitted_bss, 2031 struct cfg80211_internal_bss, 2032 pub); 2033 2034 cbss->pub.channel = chan; 2035 2036 list_for_each_entry(bss, &rdev->bss_list, list) { 2037 if (!cfg80211_bss_type_match(bss->pub.capability, 2038 bss->pub.channel->band, 2039 wdev->conn_bss_type)) 2040 continue; 2041 2042 if (bss == cbss) 2043 continue; 2044 2045 if (!cmp_bss(&bss->pub, &cbss->pub, BSS_CMP_REGULAR)) { 2046 new = bss; 2047 break; 2048 } 2049 } 2050 2051 if (new) { 2052 /* to save time, update IEs for transmitting bss only */ 2053 if (cfg80211_update_known_bss(rdev, cbss, new, false)) { 2054 new->pub.proberesp_ies = NULL; 2055 new->pub.beacon_ies = NULL; 2056 } 2057 2058 list_for_each_entry_safe(nontrans_bss, tmp, 2059 &new->pub.nontrans_list, 2060 nontrans_list) { 2061 bss = container_of(nontrans_bss, 2062 struct cfg80211_internal_bss, pub); 2063 if (__cfg80211_unlink_bss(rdev, bss)) 2064 rdev->bss_generation++; 2065 } 2066 2067 WARN_ON(atomic_read(&new->hold)); 2068 if (!WARN_ON(!__cfg80211_unlink_bss(rdev, new))) 2069 rdev->bss_generation++; 2070 } 2071 2072 rb_erase(&cbss->rbn, &rdev->bss_tree); 2073 rb_insert_bss(rdev, cbss); 2074 rdev->bss_generation++; 2075 2076 list_for_each_entry_safe(nontrans_bss, tmp, 2077 &cbss->pub.nontrans_list, 2078 nontrans_list) { 2079 bss = container_of(nontrans_bss, 2080 struct cfg80211_internal_bss, pub); 2081 bss->pub.channel = chan; 2082 rb_erase(&bss->rbn, &rdev->bss_tree); 2083 rb_insert_bss(rdev, bss); 2084 rdev->bss_generation++; 2085 } 2086 2087 done: 2088 spin_unlock_bh(&rdev->bss_lock); 2089 } 2090 2091 #ifdef CONFIG_CFG80211_WEXT 2092 static struct cfg80211_registered_device * 2093 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) 2094 { 2095 struct cfg80211_registered_device *rdev; 2096 struct net_device *dev; 2097 2098 ASSERT_RTNL(); 2099 2100 dev = dev_get_by_index(net, ifindex); 2101 if (!dev) 2102 return ERR_PTR(-ENODEV); 2103 if (dev->ieee80211_ptr) 2104 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy); 2105 else 2106 rdev = ERR_PTR(-ENODEV); 2107 dev_put(dev); 2108 return rdev; 2109 } 2110 2111 int cfg80211_wext_siwscan(struct net_device *dev, 2112 struct iw_request_info *info, 2113 union iwreq_data *wrqu, char *extra) 2114 { 2115 struct cfg80211_registered_device *rdev; 2116 struct wiphy *wiphy; 2117 struct iw_scan_req *wreq = NULL; 2118 struct cfg80211_scan_request *creq = NULL; 2119 int i, err, n_channels = 0; 2120 enum nl80211_band band; 2121 2122 if (!netif_running(dev)) 2123 return -ENETDOWN; 2124 2125 if (wrqu->data.length == sizeof(struct iw_scan_req)) 2126 wreq = (struct iw_scan_req *)extra; 2127 2128 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 2129 2130 if (IS_ERR(rdev)) 2131 return PTR_ERR(rdev); 2132 2133 if (rdev->scan_req || rdev->scan_msg) { 2134 err = -EBUSY; 2135 goto out; 2136 } 2137 2138 wiphy = &rdev->wiphy; 2139 2140 /* Determine number of channels, needed to allocate creq */ 2141 if (wreq && wreq->num_channels) 2142 n_channels = wreq->num_channels; 2143 else 2144 n_channels = ieee80211_get_num_supported_channels(wiphy); 2145 2146 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + 2147 n_channels * sizeof(void *), 2148 GFP_ATOMIC); 2149 if (!creq) { 2150 err = -ENOMEM; 2151 goto out; 2152 } 2153 2154 creq->wiphy = wiphy; 2155 creq->wdev = dev->ieee80211_ptr; 2156 /* SSIDs come after channels */ 2157 creq->ssids = (void *)&creq->channels[n_channels]; 2158 creq->n_channels = n_channels; 2159 creq->n_ssids = 1; 2160 creq->scan_start = jiffies; 2161 2162 /* translate "Scan on frequencies" request */ 2163 i = 0; 2164 for (band = 0; band < NUM_NL80211_BANDS; band++) { 2165 int j; 2166 2167 if (!wiphy->bands[band]) 2168 continue; 2169 2170 for (j = 0; j < wiphy->bands[band]->n_channels; j++) { 2171 /* ignore disabled channels */ 2172 if (wiphy->bands[band]->channels[j].flags & 2173 IEEE80211_CHAN_DISABLED) 2174 continue; 2175 2176 /* If we have a wireless request structure and the 2177 * wireless request specifies frequencies, then search 2178 * for the matching hardware channel. 2179 */ 2180 if (wreq && wreq->num_channels) { 2181 int k; 2182 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq; 2183 for (k = 0; k < wreq->num_channels; k++) { 2184 struct iw_freq *freq = 2185 &wreq->channel_list[k]; 2186 int wext_freq = 2187 cfg80211_wext_freq(freq); 2188 2189 if (wext_freq == wiphy_freq) 2190 goto wext_freq_found; 2191 } 2192 goto wext_freq_not_found; 2193 } 2194 2195 wext_freq_found: 2196 creq->channels[i] = &wiphy->bands[band]->channels[j]; 2197 i++; 2198 wext_freq_not_found: ; 2199 } 2200 } 2201 /* No channels found? */ 2202 if (!i) { 2203 err = -EINVAL; 2204 goto out; 2205 } 2206 2207 /* Set real number of channels specified in creq->channels[] */ 2208 creq->n_channels = i; 2209 2210 /* translate "Scan for SSID" request */ 2211 if (wreq) { 2212 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) { 2213 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) { 2214 err = -EINVAL; 2215 goto out; 2216 } 2217 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); 2218 creq->ssids[0].ssid_len = wreq->essid_len; 2219 } 2220 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) 2221 creq->n_ssids = 0; 2222 } 2223 2224 for (i = 0; i < NUM_NL80211_BANDS; i++) 2225 if (wiphy->bands[i]) 2226 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; 2227 2228 eth_broadcast_addr(creq->bssid); 2229 2230 rdev->scan_req = creq; 2231 err = rdev_scan(rdev, creq); 2232 if (err) { 2233 rdev->scan_req = NULL; 2234 /* creq will be freed below */ 2235 } else { 2236 nl80211_send_scan_start(rdev, dev->ieee80211_ptr); 2237 /* creq now owned by driver */ 2238 creq = NULL; 2239 dev_hold(dev); 2240 } 2241 out: 2242 kfree(creq); 2243 return err; 2244 } 2245 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan); 2246 2247 static char *ieee80211_scan_add_ies(struct iw_request_info *info, 2248 const struct cfg80211_bss_ies *ies, 2249 char *current_ev, char *end_buf) 2250 { 2251 const u8 *pos, *end, *next; 2252 struct iw_event iwe; 2253 2254 if (!ies) 2255 return current_ev; 2256 2257 /* 2258 * If needed, fragment the IEs buffer (at IE boundaries) into short 2259 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. 2260 */ 2261 pos = ies->data; 2262 end = pos + ies->len; 2263 2264 while (end - pos > IW_GENERIC_IE_MAX) { 2265 next = pos + 2 + pos[1]; 2266 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) 2267 next = next + 2 + next[1]; 2268 2269 memset(&iwe, 0, sizeof(iwe)); 2270 iwe.cmd = IWEVGENIE; 2271 iwe.u.data.length = next - pos; 2272 current_ev = iwe_stream_add_point_check(info, current_ev, 2273 end_buf, &iwe, 2274 (void *)pos); 2275 if (IS_ERR(current_ev)) 2276 return current_ev; 2277 pos = next; 2278 } 2279 2280 if (end > pos) { 2281 memset(&iwe, 0, sizeof(iwe)); 2282 iwe.cmd = IWEVGENIE; 2283 iwe.u.data.length = end - pos; 2284 current_ev = iwe_stream_add_point_check(info, current_ev, 2285 end_buf, &iwe, 2286 (void *)pos); 2287 if (IS_ERR(current_ev)) 2288 return current_ev; 2289 } 2290 2291 return current_ev; 2292 } 2293 2294 static char * 2295 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, 2296 struct cfg80211_internal_bss *bss, char *current_ev, 2297 char *end_buf) 2298 { 2299 const struct cfg80211_bss_ies *ies; 2300 struct iw_event iwe; 2301 const u8 *ie; 2302 u8 buf[50]; 2303 u8 *cfg, *p, *tmp; 2304 int rem, i, sig; 2305 bool ismesh = false; 2306 2307 memset(&iwe, 0, sizeof(iwe)); 2308 iwe.cmd = SIOCGIWAP; 2309 iwe.u.ap_addr.sa_family = ARPHRD_ETHER; 2310 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN); 2311 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2312 IW_EV_ADDR_LEN); 2313 if (IS_ERR(current_ev)) 2314 return current_ev; 2315 2316 memset(&iwe, 0, sizeof(iwe)); 2317 iwe.cmd = SIOCGIWFREQ; 2318 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq); 2319 iwe.u.freq.e = 0; 2320 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2321 IW_EV_FREQ_LEN); 2322 if (IS_ERR(current_ev)) 2323 return current_ev; 2324 2325 memset(&iwe, 0, sizeof(iwe)); 2326 iwe.cmd = SIOCGIWFREQ; 2327 iwe.u.freq.m = bss->pub.channel->center_freq; 2328 iwe.u.freq.e = 6; 2329 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2330 IW_EV_FREQ_LEN); 2331 if (IS_ERR(current_ev)) 2332 return current_ev; 2333 2334 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) { 2335 memset(&iwe, 0, sizeof(iwe)); 2336 iwe.cmd = IWEVQUAL; 2337 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED | 2338 IW_QUAL_NOISE_INVALID | 2339 IW_QUAL_QUAL_UPDATED; 2340 switch (wiphy->signal_type) { 2341 case CFG80211_SIGNAL_TYPE_MBM: 2342 sig = bss->pub.signal / 100; 2343 iwe.u.qual.level = sig; 2344 iwe.u.qual.updated |= IW_QUAL_DBM; 2345 if (sig < -110) /* rather bad */ 2346 sig = -110; 2347 else if (sig > -40) /* perfect */ 2348 sig = -40; 2349 /* will give a range of 0 .. 70 */ 2350 iwe.u.qual.qual = sig + 110; 2351 break; 2352 case CFG80211_SIGNAL_TYPE_UNSPEC: 2353 iwe.u.qual.level = bss->pub.signal; 2354 /* will give range 0 .. 100 */ 2355 iwe.u.qual.qual = bss->pub.signal; 2356 break; 2357 default: 2358 /* not reached */ 2359 break; 2360 } 2361 current_ev = iwe_stream_add_event_check(info, current_ev, 2362 end_buf, &iwe, 2363 IW_EV_QUAL_LEN); 2364 if (IS_ERR(current_ev)) 2365 return current_ev; 2366 } 2367 2368 memset(&iwe, 0, sizeof(iwe)); 2369 iwe.cmd = SIOCGIWENCODE; 2370 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY) 2371 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; 2372 else 2373 iwe.u.data.flags = IW_ENCODE_DISABLED; 2374 iwe.u.data.length = 0; 2375 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 2376 &iwe, ""); 2377 if (IS_ERR(current_ev)) 2378 return current_ev; 2379 2380 rcu_read_lock(); 2381 ies = rcu_dereference(bss->pub.ies); 2382 rem = ies->len; 2383 ie = ies->data; 2384 2385 while (rem >= 2) { 2386 /* invalid data */ 2387 if (ie[1] > rem - 2) 2388 break; 2389 2390 switch (ie[0]) { 2391 case WLAN_EID_SSID: 2392 memset(&iwe, 0, sizeof(iwe)); 2393 iwe.cmd = SIOCGIWESSID; 2394 iwe.u.data.length = ie[1]; 2395 iwe.u.data.flags = 1; 2396 current_ev = iwe_stream_add_point_check(info, 2397 current_ev, 2398 end_buf, &iwe, 2399 (u8 *)ie + 2); 2400 if (IS_ERR(current_ev)) 2401 goto unlock; 2402 break; 2403 case WLAN_EID_MESH_ID: 2404 memset(&iwe, 0, sizeof(iwe)); 2405 iwe.cmd = SIOCGIWESSID; 2406 iwe.u.data.length = ie[1]; 2407 iwe.u.data.flags = 1; 2408 current_ev = iwe_stream_add_point_check(info, 2409 current_ev, 2410 end_buf, &iwe, 2411 (u8 *)ie + 2); 2412 if (IS_ERR(current_ev)) 2413 goto unlock; 2414 break; 2415 case WLAN_EID_MESH_CONFIG: 2416 ismesh = true; 2417 if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) 2418 break; 2419 cfg = (u8 *)ie + 2; 2420 memset(&iwe, 0, sizeof(iwe)); 2421 iwe.cmd = IWEVCUSTOM; 2422 sprintf(buf, "Mesh Network Path Selection Protocol ID: " 2423 "0x%02X", cfg[0]); 2424 iwe.u.data.length = strlen(buf); 2425 current_ev = iwe_stream_add_point_check(info, 2426 current_ev, 2427 end_buf, 2428 &iwe, buf); 2429 if (IS_ERR(current_ev)) 2430 goto unlock; 2431 sprintf(buf, "Path Selection Metric ID: 0x%02X", 2432 cfg[1]); 2433 iwe.u.data.length = strlen(buf); 2434 current_ev = iwe_stream_add_point_check(info, 2435 current_ev, 2436 end_buf, 2437 &iwe, buf); 2438 if (IS_ERR(current_ev)) 2439 goto unlock; 2440 sprintf(buf, "Congestion Control Mode ID: 0x%02X", 2441 cfg[2]); 2442 iwe.u.data.length = strlen(buf); 2443 current_ev = iwe_stream_add_point_check(info, 2444 current_ev, 2445 end_buf, 2446 &iwe, buf); 2447 if (IS_ERR(current_ev)) 2448 goto unlock; 2449 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]); 2450 iwe.u.data.length = strlen(buf); 2451 current_ev = iwe_stream_add_point_check(info, 2452 current_ev, 2453 end_buf, 2454 &iwe, buf); 2455 if (IS_ERR(current_ev)) 2456 goto unlock; 2457 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]); 2458 iwe.u.data.length = strlen(buf); 2459 current_ev = iwe_stream_add_point_check(info, 2460 current_ev, 2461 end_buf, 2462 &iwe, buf); 2463 if (IS_ERR(current_ev)) 2464 goto unlock; 2465 sprintf(buf, "Formation Info: 0x%02X", cfg[5]); 2466 iwe.u.data.length = strlen(buf); 2467 current_ev = iwe_stream_add_point_check(info, 2468 current_ev, 2469 end_buf, 2470 &iwe, buf); 2471 if (IS_ERR(current_ev)) 2472 goto unlock; 2473 sprintf(buf, "Capabilities: 0x%02X", cfg[6]); 2474 iwe.u.data.length = strlen(buf); 2475 current_ev = iwe_stream_add_point_check(info, 2476 current_ev, 2477 end_buf, 2478 &iwe, buf); 2479 if (IS_ERR(current_ev)) 2480 goto unlock; 2481 break; 2482 case WLAN_EID_SUPP_RATES: 2483 case WLAN_EID_EXT_SUPP_RATES: 2484 /* display all supported rates in readable format */ 2485 p = current_ev + iwe_stream_lcp_len(info); 2486 2487 memset(&iwe, 0, sizeof(iwe)); 2488 iwe.cmd = SIOCGIWRATE; 2489 /* Those two flags are ignored... */ 2490 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; 2491 2492 for (i = 0; i < ie[1]; i++) { 2493 iwe.u.bitrate.value = 2494 ((ie[i + 2] & 0x7f) * 500000); 2495 tmp = p; 2496 p = iwe_stream_add_value(info, current_ev, p, 2497 end_buf, &iwe, 2498 IW_EV_PARAM_LEN); 2499 if (p == tmp) { 2500 current_ev = ERR_PTR(-E2BIG); 2501 goto unlock; 2502 } 2503 } 2504 current_ev = p; 2505 break; 2506 } 2507 rem -= ie[1] + 2; 2508 ie += ie[1] + 2; 2509 } 2510 2511 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) || 2512 ismesh) { 2513 memset(&iwe, 0, sizeof(iwe)); 2514 iwe.cmd = SIOCGIWMODE; 2515 if (ismesh) 2516 iwe.u.mode = IW_MODE_MESH; 2517 else if (bss->pub.capability & WLAN_CAPABILITY_ESS) 2518 iwe.u.mode = IW_MODE_MASTER; 2519 else 2520 iwe.u.mode = IW_MODE_ADHOC; 2521 current_ev = iwe_stream_add_event_check(info, current_ev, 2522 end_buf, &iwe, 2523 IW_EV_UINT_LEN); 2524 if (IS_ERR(current_ev)) 2525 goto unlock; 2526 } 2527 2528 memset(&iwe, 0, sizeof(iwe)); 2529 iwe.cmd = IWEVCUSTOM; 2530 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf)); 2531 iwe.u.data.length = strlen(buf); 2532 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 2533 &iwe, buf); 2534 if (IS_ERR(current_ev)) 2535 goto unlock; 2536 memset(&iwe, 0, sizeof(iwe)); 2537 iwe.cmd = IWEVCUSTOM; 2538 sprintf(buf, " Last beacon: %ums ago", 2539 elapsed_jiffies_msecs(bss->ts)); 2540 iwe.u.data.length = strlen(buf); 2541 current_ev = iwe_stream_add_point_check(info, current_ev, 2542 end_buf, &iwe, buf); 2543 if (IS_ERR(current_ev)) 2544 goto unlock; 2545 2546 current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf); 2547 2548 unlock: 2549 rcu_read_unlock(); 2550 return current_ev; 2551 } 2552 2553 2554 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev, 2555 struct iw_request_info *info, 2556 char *buf, size_t len) 2557 { 2558 char *current_ev = buf; 2559 char *end_buf = buf + len; 2560 struct cfg80211_internal_bss *bss; 2561 int err = 0; 2562 2563 spin_lock_bh(&rdev->bss_lock); 2564 cfg80211_bss_expire(rdev); 2565 2566 list_for_each_entry(bss, &rdev->bss_list, list) { 2567 if (buf + len - current_ev <= IW_EV_ADDR_LEN) { 2568 err = -E2BIG; 2569 break; 2570 } 2571 current_ev = ieee80211_bss(&rdev->wiphy, info, bss, 2572 current_ev, end_buf); 2573 if (IS_ERR(current_ev)) { 2574 err = PTR_ERR(current_ev); 2575 break; 2576 } 2577 } 2578 spin_unlock_bh(&rdev->bss_lock); 2579 2580 if (err) 2581 return err; 2582 return current_ev - buf; 2583 } 2584 2585 2586 int cfg80211_wext_giwscan(struct net_device *dev, 2587 struct iw_request_info *info, 2588 struct iw_point *data, char *extra) 2589 { 2590 struct cfg80211_registered_device *rdev; 2591 int res; 2592 2593 if (!netif_running(dev)) 2594 return -ENETDOWN; 2595 2596 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 2597 2598 if (IS_ERR(rdev)) 2599 return PTR_ERR(rdev); 2600 2601 if (rdev->scan_req || rdev->scan_msg) 2602 return -EAGAIN; 2603 2604 res = ieee80211_scan_results(rdev, info, extra, data->length); 2605 data->length = 0; 2606 if (res >= 0) { 2607 data->length = res; 2608 res = 0; 2609 } 2610 2611 return res; 2612 } 2613 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan); 2614 #endif 2615