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) 2018-2021 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 <linux/crc32.h> 18 #include <linux/bitfield.h> 19 #include <net/arp.h> 20 #include <net/cfg80211.h> 21 #include <net/cfg80211-wext.h> 22 #include <net/iw_handler.h> 23 #include "core.h" 24 #include "nl80211.h" 25 #include "wext-compat.h" 26 #include "rdev-ops.h" 27 28 /** 29 * DOC: BSS tree/list structure 30 * 31 * At the top level, the BSS list is kept in both a list in each 32 * registered device (@bss_list) as well as an RB-tree for faster 33 * lookup. In the RB-tree, entries can be looked up using their 34 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID 35 * for other BSSes. 36 * 37 * Due to the possibility of hidden SSIDs, there's a second level 38 * structure, the "hidden_list" and "hidden_beacon_bss" pointer. 39 * The hidden_list connects all BSSes belonging to a single AP 40 * that has a hidden SSID, and connects beacon and probe response 41 * entries. For a probe response entry for a hidden SSID, the 42 * hidden_beacon_bss pointer points to the BSS struct holding the 43 * beacon's information. 44 * 45 * Reference counting is done for all these references except for 46 * the hidden_list, so that a beacon BSS struct that is otherwise 47 * not referenced has one reference for being on the bss_list and 48 * one for each probe response entry that points to it using the 49 * hidden_beacon_bss pointer. When a BSS struct that has such a 50 * pointer is get/put, the refcount update is also propagated to 51 * the referenced struct, this ensure that it cannot get removed 52 * while somebody is using the probe response version. 53 * 54 * Note that the hidden_beacon_bss pointer never changes, due to 55 * the reference counting. Therefore, no locking is needed for 56 * it. 57 * 58 * Also note that the hidden_beacon_bss pointer is only relevant 59 * if the driver uses something other than the IEs, e.g. private 60 * data stored in the BSS struct, since the beacon IEs are 61 * also linked into the probe response struct. 62 */ 63 64 /* 65 * Limit the number of BSS entries stored in mac80211. Each one is 66 * a bit over 4k at most, so this limits to roughly 4-5M of memory. 67 * If somebody wants to really attack this though, they'd likely 68 * use small beacons, and only one type of frame, limiting each of 69 * the entries to a much smaller size (in order to generate more 70 * entries in total, so overhead is bigger.) 71 */ 72 static int bss_entries_limit = 1000; 73 module_param(bss_entries_limit, int, 0644); 74 MODULE_PARM_DESC(bss_entries_limit, 75 "limit to number of scan BSS entries (per wiphy, default 1000)"); 76 77 #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) 78 79 /** 80 * struct cfg80211_colocated_ap - colocated AP information 81 * 82 * @list: linked list to all colocated aPS 83 * @bssid: BSSID of the reported AP 84 * @ssid: SSID of the reported AP 85 * @ssid_len: length of the ssid 86 * @center_freq: frequency the reported AP is on 87 * @unsolicited_probe: the reported AP is part of an ESS, where all the APs 88 * that operate in the same channel as the reported AP and that might be 89 * detected by a STA receiving this frame, are transmitting unsolicited 90 * Probe Response frames every 20 TUs 91 * @oct_recommended: OCT is recommended to exchange MMPDUs with the reported AP 92 * @same_ssid: the reported AP has the same SSID as the reporting AP 93 * @multi_bss: the reported AP is part of a multiple BSSID set 94 * @transmitted_bssid: the reported AP is the transmitting BSSID 95 * @colocated_ess: all the APs that share the same ESS as the reported AP are 96 * colocated and can be discovered via legacy bands. 97 * @short_ssid_valid: short_ssid is valid and can be used 98 * @short_ssid: the short SSID for this SSID 99 */ 100 struct cfg80211_colocated_ap { 101 struct list_head list; 102 u8 bssid[ETH_ALEN]; 103 u8 ssid[IEEE80211_MAX_SSID_LEN]; 104 size_t ssid_len; 105 u32 short_ssid; 106 u32 center_freq; 107 u8 unsolicited_probe:1, 108 oct_recommended:1, 109 same_ssid:1, 110 multi_bss:1, 111 transmitted_bssid:1, 112 colocated_ess:1, 113 short_ssid_valid:1; 114 }; 115 116 static void bss_free(struct cfg80211_internal_bss *bss) 117 { 118 struct cfg80211_bss_ies *ies; 119 120 if (WARN_ON(atomic_read(&bss->hold))) 121 return; 122 123 ies = (void *)rcu_access_pointer(bss->pub.beacon_ies); 124 if (ies && !bss->pub.hidden_beacon_bss) 125 kfree_rcu(ies, rcu_head); 126 ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies); 127 if (ies) 128 kfree_rcu(ies, rcu_head); 129 130 /* 131 * This happens when the module is removed, it doesn't 132 * really matter any more save for completeness 133 */ 134 if (!list_empty(&bss->hidden_list)) 135 list_del(&bss->hidden_list); 136 137 kfree(bss); 138 } 139 140 static inline void bss_ref_get(struct cfg80211_registered_device *rdev, 141 struct cfg80211_internal_bss *bss) 142 { 143 lockdep_assert_held(&rdev->bss_lock); 144 145 bss->refcount++; 146 if (bss->pub.hidden_beacon_bss) { 147 bss = container_of(bss->pub.hidden_beacon_bss, 148 struct cfg80211_internal_bss, 149 pub); 150 bss->refcount++; 151 } 152 if (bss->pub.transmitted_bss) { 153 bss = container_of(bss->pub.transmitted_bss, 154 struct cfg80211_internal_bss, 155 pub); 156 bss->refcount++; 157 } 158 } 159 160 static inline void bss_ref_put(struct cfg80211_registered_device *rdev, 161 struct cfg80211_internal_bss *bss) 162 { 163 lockdep_assert_held(&rdev->bss_lock); 164 165 if (bss->pub.hidden_beacon_bss) { 166 struct cfg80211_internal_bss *hbss; 167 hbss = container_of(bss->pub.hidden_beacon_bss, 168 struct cfg80211_internal_bss, 169 pub); 170 hbss->refcount--; 171 if (hbss->refcount == 0) 172 bss_free(hbss); 173 } 174 175 if (bss->pub.transmitted_bss) { 176 struct cfg80211_internal_bss *tbss; 177 178 tbss = container_of(bss->pub.transmitted_bss, 179 struct cfg80211_internal_bss, 180 pub); 181 tbss->refcount--; 182 if (tbss->refcount == 0) 183 bss_free(tbss); 184 } 185 186 bss->refcount--; 187 if (bss->refcount == 0) 188 bss_free(bss); 189 } 190 191 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, 192 struct cfg80211_internal_bss *bss) 193 { 194 lockdep_assert_held(&rdev->bss_lock); 195 196 if (!list_empty(&bss->hidden_list)) { 197 /* 198 * don't remove the beacon entry if it has 199 * probe responses associated with it 200 */ 201 if (!bss->pub.hidden_beacon_bss) 202 return false; 203 /* 204 * if it's a probe response entry break its 205 * link to the other entries in the group 206 */ 207 list_del_init(&bss->hidden_list); 208 } 209 210 list_del_init(&bss->list); 211 list_del_init(&bss->pub.nontrans_list); 212 rb_erase(&bss->rbn, &rdev->bss_tree); 213 rdev->bss_entries--; 214 WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list), 215 "rdev bss entries[%d]/list[empty:%d] corruption\n", 216 rdev->bss_entries, list_empty(&rdev->bss_list)); 217 bss_ref_put(rdev, bss); 218 return true; 219 } 220 221 bool cfg80211_is_element_inherited(const struct element *elem, 222 const struct element *non_inherit_elem) 223 { 224 u8 id_len, ext_id_len, i, loop_len, id; 225 const u8 *list; 226 227 if (elem->id == WLAN_EID_MULTIPLE_BSSID) 228 return false; 229 230 if (!non_inherit_elem || non_inherit_elem->datalen < 2) 231 return true; 232 233 /* 234 * non inheritance element format is: 235 * ext ID (56) | IDs list len | list | extension IDs list len | list 236 * Both lists are optional. Both lengths are mandatory. 237 * This means valid length is: 238 * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths 239 */ 240 id_len = non_inherit_elem->data[1]; 241 if (non_inherit_elem->datalen < 3 + id_len) 242 return true; 243 244 ext_id_len = non_inherit_elem->data[2 + id_len]; 245 if (non_inherit_elem->datalen < 3 + id_len + ext_id_len) 246 return true; 247 248 if (elem->id == WLAN_EID_EXTENSION) { 249 if (!ext_id_len) 250 return true; 251 loop_len = ext_id_len; 252 list = &non_inherit_elem->data[3 + id_len]; 253 id = elem->data[0]; 254 } else { 255 if (!id_len) 256 return true; 257 loop_len = id_len; 258 list = &non_inherit_elem->data[2]; 259 id = elem->id; 260 } 261 262 for (i = 0; i < loop_len; i++) { 263 if (list[i] == id) 264 return false; 265 } 266 267 return true; 268 } 269 EXPORT_SYMBOL(cfg80211_is_element_inherited); 270 271 static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, 272 const u8 *subelement, size_t subie_len, 273 u8 *new_ie, gfp_t gfp) 274 { 275 u8 *pos, *tmp; 276 const u8 *tmp_old, *tmp_new; 277 const struct element *non_inherit_elem; 278 u8 *sub_copy; 279 280 /* copy subelement as we need to change its content to 281 * mark an ie after it is processed. 282 */ 283 sub_copy = kmemdup(subelement, subie_len, gfp); 284 if (!sub_copy) 285 return 0; 286 287 pos = &new_ie[0]; 288 289 /* set new ssid */ 290 tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len); 291 if (tmp_new) { 292 memcpy(pos, tmp_new, tmp_new[1] + 2); 293 pos += (tmp_new[1] + 2); 294 } 295 296 /* get non inheritance list if exists */ 297 non_inherit_elem = 298 cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, 299 sub_copy, subie_len); 300 301 /* go through IEs in ie (skip SSID) and subelement, 302 * merge them into new_ie 303 */ 304 tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); 305 tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie; 306 307 while (tmp_old + tmp_old[1] + 2 - ie <= ielen) { 308 if (tmp_old[0] == 0) { 309 tmp_old++; 310 continue; 311 } 312 313 if (tmp_old[0] == WLAN_EID_EXTENSION) 314 tmp = (u8 *)cfg80211_find_ext_ie(tmp_old[2], sub_copy, 315 subie_len); 316 else 317 tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy, 318 subie_len); 319 320 if (!tmp) { 321 const struct element *old_elem = (void *)tmp_old; 322 323 /* ie in old ie but not in subelement */ 324 if (cfg80211_is_element_inherited(old_elem, 325 non_inherit_elem)) { 326 memcpy(pos, tmp_old, tmp_old[1] + 2); 327 pos += tmp_old[1] + 2; 328 } 329 } else { 330 /* ie in transmitting ie also in subelement, 331 * copy from subelement and flag the ie in subelement 332 * as copied (by setting eid field to WLAN_EID_SSID, 333 * which is skipped anyway). 334 * For vendor ie, compare OUI + type + subType to 335 * determine if they are the same ie. 336 */ 337 if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) { 338 if (!memcmp(tmp_old + 2, tmp + 2, 5)) { 339 /* same vendor ie, copy from 340 * subelement 341 */ 342 memcpy(pos, tmp, tmp[1] + 2); 343 pos += tmp[1] + 2; 344 tmp[0] = WLAN_EID_SSID; 345 } else { 346 memcpy(pos, tmp_old, tmp_old[1] + 2); 347 pos += tmp_old[1] + 2; 348 } 349 } else { 350 /* copy ie from subelement into new ie */ 351 memcpy(pos, tmp, tmp[1] + 2); 352 pos += tmp[1] + 2; 353 tmp[0] = WLAN_EID_SSID; 354 } 355 } 356 357 if (tmp_old + tmp_old[1] + 2 - ie == ielen) 358 break; 359 360 tmp_old += tmp_old[1] + 2; 361 } 362 363 /* go through subelement again to check if there is any ie not 364 * copied to new ie, skip ssid, capability, bssid-index ie 365 */ 366 tmp_new = sub_copy; 367 while (tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) { 368 if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP || 369 tmp_new[0] == WLAN_EID_SSID)) { 370 memcpy(pos, tmp_new, tmp_new[1] + 2); 371 pos += tmp_new[1] + 2; 372 } 373 if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len) 374 break; 375 tmp_new += tmp_new[1] + 2; 376 } 377 378 kfree(sub_copy); 379 return pos - new_ie; 380 } 381 382 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, 383 const u8 *ssid, size_t ssid_len) 384 { 385 const struct cfg80211_bss_ies *ies; 386 const struct element *ssid_elem; 387 388 if (bssid && !ether_addr_equal(a->bssid, bssid)) 389 return false; 390 391 if (!ssid) 392 return true; 393 394 ies = rcu_access_pointer(a->ies); 395 if (!ies) 396 return false; 397 ssid_elem = cfg80211_find_elem(WLAN_EID_SSID, ies->data, ies->len); 398 if (!ssid_elem) 399 return false; 400 if (ssid_elem->datalen != ssid_len) 401 return false; 402 return memcmp(ssid_elem->data, ssid, ssid_len) == 0; 403 } 404 405 static int 406 cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss, 407 struct cfg80211_bss *nontrans_bss) 408 { 409 const u8 *ssid; 410 size_t ssid_len; 411 struct cfg80211_bss *bss = NULL; 412 413 rcu_read_lock(); 414 ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); 415 if (!ssid) { 416 rcu_read_unlock(); 417 return -EINVAL; 418 } 419 ssid_len = ssid[1]; 420 ssid = ssid + 2; 421 rcu_read_unlock(); 422 423 /* check if nontrans_bss is in the list */ 424 list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) { 425 if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) 426 return 0; 427 } 428 429 /* add to the list */ 430 list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); 431 return 0; 432 } 433 434 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, 435 unsigned long expire_time) 436 { 437 struct cfg80211_internal_bss *bss, *tmp; 438 bool expired = false; 439 440 lockdep_assert_held(&rdev->bss_lock); 441 442 list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) { 443 if (atomic_read(&bss->hold)) 444 continue; 445 if (!time_after(expire_time, bss->ts)) 446 continue; 447 448 if (__cfg80211_unlink_bss(rdev, bss)) 449 expired = true; 450 } 451 452 if (expired) 453 rdev->bss_generation++; 454 } 455 456 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) 457 { 458 struct cfg80211_internal_bss *bss, *oldest = NULL; 459 bool ret; 460 461 lockdep_assert_held(&rdev->bss_lock); 462 463 list_for_each_entry(bss, &rdev->bss_list, list) { 464 if (atomic_read(&bss->hold)) 465 continue; 466 467 if (!list_empty(&bss->hidden_list) && 468 !bss->pub.hidden_beacon_bss) 469 continue; 470 471 if (oldest && time_before(oldest->ts, bss->ts)) 472 continue; 473 oldest = bss; 474 } 475 476 if (WARN_ON(!oldest)) 477 return false; 478 479 /* 480 * The callers make sure to increase rdev->bss_generation if anything 481 * gets removed (and a new entry added), so there's no need to also do 482 * it here. 483 */ 484 485 ret = __cfg80211_unlink_bss(rdev, oldest); 486 WARN_ON(!ret); 487 return ret; 488 } 489 490 static u8 cfg80211_parse_bss_param(u8 data, 491 struct cfg80211_colocated_ap *coloc_ap) 492 { 493 coloc_ap->oct_recommended = 494 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_OCT_RECOMMENDED); 495 coloc_ap->same_ssid = 496 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_SAME_SSID); 497 coloc_ap->multi_bss = 498 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_MULTI_BSSID); 499 coloc_ap->transmitted_bssid = 500 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_TRANSMITTED_BSSID); 501 coloc_ap->unsolicited_probe = 502 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_PROBE_ACTIVE); 503 coloc_ap->colocated_ess = 504 u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_ESS); 505 506 return u8_get_bits(data, IEEE80211_RNR_TBTT_PARAMS_COLOC_AP); 507 } 508 509 static int cfg80211_calc_short_ssid(const struct cfg80211_bss_ies *ies, 510 const struct element **elem, u32 *s_ssid) 511 { 512 513 *elem = cfg80211_find_elem(WLAN_EID_SSID, ies->data, ies->len); 514 if (!*elem || (*elem)->datalen > IEEE80211_MAX_SSID_LEN) 515 return -EINVAL; 516 517 *s_ssid = ~crc32_le(~0, (*elem)->data, (*elem)->datalen); 518 return 0; 519 } 520 521 static void cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list) 522 { 523 struct cfg80211_colocated_ap *ap, *tmp_ap; 524 525 list_for_each_entry_safe(ap, tmp_ap, coloc_ap_list, list) { 526 list_del(&ap->list); 527 kfree(ap); 528 } 529 } 530 531 static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry, 532 const u8 *pos, u8 length, 533 const struct element *ssid_elem, 534 int s_ssid_tmp) 535 { 536 /* skip the TBTT offset */ 537 pos++; 538 539 memcpy(entry->bssid, pos, ETH_ALEN); 540 pos += ETH_ALEN; 541 542 if (length == IEEE80211_TBTT_INFO_OFFSET_BSSID_SSSID_BSS_PARAM) { 543 memcpy(&entry->short_ssid, pos, 544 sizeof(entry->short_ssid)); 545 entry->short_ssid_valid = true; 546 pos += 4; 547 } 548 549 /* skip non colocated APs */ 550 if (!cfg80211_parse_bss_param(*pos, entry)) 551 return -EINVAL; 552 pos++; 553 554 if (length == IEEE80211_TBTT_INFO_OFFSET_BSSID_BSS_PARAM) { 555 /* 556 * no information about the short ssid. Consider the entry valid 557 * for now. It would later be dropped in case there are explicit 558 * SSIDs that need to be matched 559 */ 560 if (!entry->same_ssid) 561 return 0; 562 } 563 564 if (entry->same_ssid) { 565 entry->short_ssid = s_ssid_tmp; 566 entry->short_ssid_valid = true; 567 568 /* 569 * This is safe because we validate datalen in 570 * cfg80211_parse_colocated_ap(), before calling this 571 * function. 572 */ 573 memcpy(&entry->ssid, &ssid_elem->data, 574 ssid_elem->datalen); 575 entry->ssid_len = ssid_elem->datalen; 576 } 577 return 0; 578 } 579 580 static int cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies, 581 struct list_head *list) 582 { 583 struct ieee80211_neighbor_ap_info *ap_info; 584 const struct element *elem, *ssid_elem; 585 const u8 *pos, *end; 586 u32 s_ssid_tmp; 587 int n_coloc = 0, ret; 588 LIST_HEAD(ap_list); 589 590 elem = cfg80211_find_elem(WLAN_EID_REDUCED_NEIGHBOR_REPORT, ies->data, 591 ies->len); 592 if (!elem) 593 return 0; 594 595 pos = elem->data; 596 end = pos + elem->datalen; 597 598 ret = cfg80211_calc_short_ssid(ies, &ssid_elem, &s_ssid_tmp); 599 if (ret) 600 return ret; 601 602 /* RNR IE may contain more than one NEIGHBOR_AP_INFO */ 603 while (pos + sizeof(*ap_info) <= end) { 604 enum nl80211_band band; 605 int freq; 606 u8 length, i, count; 607 608 ap_info = (void *)pos; 609 count = u8_get_bits(ap_info->tbtt_info_hdr, 610 IEEE80211_AP_INFO_TBTT_HDR_COUNT) + 1; 611 length = ap_info->tbtt_info_len; 612 613 pos += sizeof(*ap_info); 614 615 if (!ieee80211_operating_class_to_band(ap_info->op_class, 616 &band)) 617 break; 618 619 freq = ieee80211_channel_to_frequency(ap_info->channel, band); 620 621 if (end - pos < count * length) 622 break; 623 624 /* 625 * TBTT info must include bss param + BSSID + 626 * (short SSID or same_ssid bit to be set). 627 * ignore other options, and move to the 628 * next AP info 629 */ 630 if (band != NL80211_BAND_6GHZ || 631 (length != IEEE80211_TBTT_INFO_OFFSET_BSSID_BSS_PARAM && 632 length < IEEE80211_TBTT_INFO_OFFSET_BSSID_SSSID_BSS_PARAM)) { 633 pos += count * length; 634 continue; 635 } 636 637 for (i = 0; i < count; i++) { 638 struct cfg80211_colocated_ap *entry; 639 640 entry = kzalloc(sizeof(*entry) + IEEE80211_MAX_SSID_LEN, 641 GFP_ATOMIC); 642 643 if (!entry) 644 break; 645 646 entry->center_freq = freq; 647 648 if (!cfg80211_parse_ap_info(entry, pos, length, 649 ssid_elem, s_ssid_tmp)) { 650 n_coloc++; 651 list_add_tail(&entry->list, &ap_list); 652 } else { 653 kfree(entry); 654 } 655 656 pos += length; 657 } 658 } 659 660 if (pos != end) { 661 cfg80211_free_coloc_ap_list(&ap_list); 662 return 0; 663 } 664 665 list_splice_tail(&ap_list, list); 666 return n_coloc; 667 } 668 669 static void cfg80211_scan_req_add_chan(struct cfg80211_scan_request *request, 670 struct ieee80211_channel *chan, 671 bool add_to_6ghz) 672 { 673 int i; 674 u32 n_channels = request->n_channels; 675 struct cfg80211_scan_6ghz_params *params = 676 &request->scan_6ghz_params[request->n_6ghz_params]; 677 678 for (i = 0; i < n_channels; i++) { 679 if (request->channels[i] == chan) { 680 if (add_to_6ghz) 681 params->channel_idx = i; 682 return; 683 } 684 } 685 686 request->channels[n_channels] = chan; 687 if (add_to_6ghz) 688 request->scan_6ghz_params[request->n_6ghz_params].channel_idx = 689 n_channels; 690 691 request->n_channels++; 692 } 693 694 static bool cfg80211_find_ssid_match(struct cfg80211_colocated_ap *ap, 695 struct cfg80211_scan_request *request) 696 { 697 int i; 698 u32 s_ssid; 699 700 for (i = 0; i < request->n_ssids; i++) { 701 /* wildcard ssid in the scan request */ 702 if (!request->ssids[i].ssid_len) 703 return true; 704 705 if (ap->ssid_len && 706 ap->ssid_len == request->ssids[i].ssid_len) { 707 if (!memcmp(request->ssids[i].ssid, ap->ssid, 708 ap->ssid_len)) 709 return true; 710 } else if (ap->short_ssid_valid) { 711 s_ssid = ~crc32_le(~0, request->ssids[i].ssid, 712 request->ssids[i].ssid_len); 713 714 if (ap->short_ssid == s_ssid) 715 return true; 716 } 717 } 718 719 return false; 720 } 721 722 static int cfg80211_scan_6ghz(struct cfg80211_registered_device *rdev) 723 { 724 u8 i; 725 struct cfg80211_colocated_ap *ap; 726 int n_channels, count = 0, err; 727 struct cfg80211_scan_request *request, *rdev_req = rdev->scan_req; 728 LIST_HEAD(coloc_ap_list); 729 bool need_scan_psc = true; 730 const struct ieee80211_sband_iftype_data *iftd; 731 732 rdev_req->scan_6ghz = true; 733 734 if (!rdev->wiphy.bands[NL80211_BAND_6GHZ]) 735 return -EOPNOTSUPP; 736 737 iftd = ieee80211_get_sband_iftype_data(rdev->wiphy.bands[NL80211_BAND_6GHZ], 738 rdev_req->wdev->iftype); 739 if (!iftd || !iftd->he_cap.has_he) 740 return -EOPNOTSUPP; 741 742 n_channels = rdev->wiphy.bands[NL80211_BAND_6GHZ]->n_channels; 743 744 if (rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ) { 745 struct cfg80211_internal_bss *intbss; 746 747 spin_lock_bh(&rdev->bss_lock); 748 list_for_each_entry(intbss, &rdev->bss_list, list) { 749 struct cfg80211_bss *res = &intbss->pub; 750 const struct cfg80211_bss_ies *ies; 751 752 ies = rcu_access_pointer(res->ies); 753 count += cfg80211_parse_colocated_ap(ies, 754 &coloc_ap_list); 755 } 756 spin_unlock_bh(&rdev->bss_lock); 757 } 758 759 request = kzalloc(struct_size(request, channels, n_channels) + 760 sizeof(*request->scan_6ghz_params) * count + 761 sizeof(*request->ssids) * rdev_req->n_ssids, 762 GFP_KERNEL); 763 if (!request) { 764 cfg80211_free_coloc_ap_list(&coloc_ap_list); 765 return -ENOMEM; 766 } 767 768 *request = *rdev_req; 769 request->n_channels = 0; 770 request->scan_6ghz_params = 771 (void *)&request->channels[n_channels]; 772 773 /* 774 * PSC channels should not be scanned in case of direct scan with 1 SSID 775 * and at least one of the reported co-located APs with same SSID 776 * indicating that all APs in the same ESS are co-located 777 */ 778 if (count && request->n_ssids == 1 && request->ssids[0].ssid_len) { 779 list_for_each_entry(ap, &coloc_ap_list, list) { 780 if (ap->colocated_ess && 781 cfg80211_find_ssid_match(ap, request)) { 782 need_scan_psc = false; 783 break; 784 } 785 } 786 } 787 788 /* 789 * add to the scan request the channels that need to be scanned 790 * regardless of the collocated APs (PSC channels or all channels 791 * in case that NL80211_SCAN_FLAG_COLOCATED_6GHZ is not set) 792 */ 793 for (i = 0; i < rdev_req->n_channels; i++) { 794 if (rdev_req->channels[i]->band == NL80211_BAND_6GHZ && 795 ((need_scan_psc && 796 cfg80211_channel_is_psc(rdev_req->channels[i])) || 797 !(rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ))) { 798 cfg80211_scan_req_add_chan(request, 799 rdev_req->channels[i], 800 false); 801 } 802 } 803 804 if (!(rdev_req->flags & NL80211_SCAN_FLAG_COLOCATED_6GHZ)) 805 goto skip; 806 807 list_for_each_entry(ap, &coloc_ap_list, list) { 808 bool found = false; 809 struct cfg80211_scan_6ghz_params *scan_6ghz_params = 810 &request->scan_6ghz_params[request->n_6ghz_params]; 811 struct ieee80211_channel *chan = 812 ieee80211_get_channel(&rdev->wiphy, ap->center_freq); 813 814 if (!chan || chan->flags & IEEE80211_CHAN_DISABLED) 815 continue; 816 817 for (i = 0; i < rdev_req->n_channels; i++) { 818 if (rdev_req->channels[i] == chan) 819 found = true; 820 } 821 822 if (!found) 823 continue; 824 825 if (request->n_ssids > 0 && 826 !cfg80211_find_ssid_match(ap, request)) 827 continue; 828 829 cfg80211_scan_req_add_chan(request, chan, true); 830 memcpy(scan_6ghz_params->bssid, ap->bssid, ETH_ALEN); 831 scan_6ghz_params->short_ssid = ap->short_ssid; 832 scan_6ghz_params->short_ssid_valid = ap->short_ssid_valid; 833 scan_6ghz_params->unsolicited_probe = ap->unsolicited_probe; 834 835 /* 836 * If a PSC channel is added to the scan and 'need_scan_psc' is 837 * set to false, then all the APs that the scan logic is 838 * interested with on the channel are collocated and thus there 839 * is no need to perform the initial PSC channel listen. 840 */ 841 if (cfg80211_channel_is_psc(chan) && !need_scan_psc) 842 scan_6ghz_params->psc_no_listen = true; 843 844 request->n_6ghz_params++; 845 } 846 847 skip: 848 cfg80211_free_coloc_ap_list(&coloc_ap_list); 849 850 if (request->n_channels) { 851 struct cfg80211_scan_request *old = rdev->int_scan_req; 852 rdev->int_scan_req = request; 853 854 /* 855 * Add the ssids from the parent scan request to the new scan 856 * request, so the driver would be able to use them in its 857 * probe requests to discover hidden APs on PSC channels. 858 */ 859 request->ssids = (void *)&request->channels[request->n_channels]; 860 request->n_ssids = rdev_req->n_ssids; 861 memcpy(request->ssids, rdev_req->ssids, sizeof(*request->ssids) * 862 request->n_ssids); 863 864 /* 865 * If this scan follows a previous scan, save the scan start 866 * info from the first part of the scan 867 */ 868 if (old) 869 rdev->int_scan_req->info = old->info; 870 871 err = rdev_scan(rdev, request); 872 if (err) { 873 rdev->int_scan_req = old; 874 kfree(request); 875 } else { 876 kfree(old); 877 } 878 879 return err; 880 } 881 882 kfree(request); 883 return -EINVAL; 884 } 885 886 int cfg80211_scan(struct cfg80211_registered_device *rdev) 887 { 888 struct cfg80211_scan_request *request; 889 struct cfg80211_scan_request *rdev_req = rdev->scan_req; 890 u32 n_channels = 0, idx, i; 891 892 if (!(rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ)) 893 return rdev_scan(rdev, rdev_req); 894 895 for (i = 0; i < rdev_req->n_channels; i++) { 896 if (rdev_req->channels[i]->band != NL80211_BAND_6GHZ) 897 n_channels++; 898 } 899 900 if (!n_channels) 901 return cfg80211_scan_6ghz(rdev); 902 903 request = kzalloc(struct_size(request, channels, n_channels), 904 GFP_KERNEL); 905 if (!request) 906 return -ENOMEM; 907 908 *request = *rdev_req; 909 request->n_channels = n_channels; 910 911 for (i = idx = 0; i < rdev_req->n_channels; i++) { 912 if (rdev_req->channels[i]->band != NL80211_BAND_6GHZ) 913 request->channels[idx++] = rdev_req->channels[i]; 914 } 915 916 rdev_req->scan_6ghz = false; 917 rdev->int_scan_req = request; 918 return rdev_scan(rdev, request); 919 } 920 921 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, 922 bool send_message) 923 { 924 struct cfg80211_scan_request *request, *rdev_req; 925 struct wireless_dev *wdev; 926 struct sk_buff *msg; 927 #ifdef CONFIG_CFG80211_WEXT 928 union iwreq_data wrqu; 929 #endif 930 931 lockdep_assert_held(&rdev->wiphy.mtx); 932 933 if (rdev->scan_msg) { 934 nl80211_send_scan_msg(rdev, rdev->scan_msg); 935 rdev->scan_msg = NULL; 936 return; 937 } 938 939 rdev_req = rdev->scan_req; 940 if (!rdev_req) 941 return; 942 943 wdev = rdev_req->wdev; 944 request = rdev->int_scan_req ? rdev->int_scan_req : rdev_req; 945 946 if (wdev_running(wdev) && 947 (rdev->wiphy.flags & WIPHY_FLAG_SPLIT_SCAN_6GHZ) && 948 !rdev_req->scan_6ghz && !request->info.aborted && 949 !cfg80211_scan_6ghz(rdev)) 950 return; 951 952 /* 953 * This must be before sending the other events! 954 * Otherwise, wpa_supplicant gets completely confused with 955 * wext events. 956 */ 957 if (wdev->netdev) 958 cfg80211_sme_scan_done(wdev->netdev); 959 960 if (!request->info.aborted && 961 request->flags & NL80211_SCAN_FLAG_FLUSH) { 962 /* flush entries from previous scans */ 963 spin_lock_bh(&rdev->bss_lock); 964 __cfg80211_bss_expire(rdev, request->scan_start); 965 spin_unlock_bh(&rdev->bss_lock); 966 } 967 968 msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted); 969 970 #ifdef CONFIG_CFG80211_WEXT 971 if (wdev->netdev && !request->info.aborted) { 972 memset(&wrqu, 0, sizeof(wrqu)); 973 974 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL); 975 } 976 #endif 977 978 dev_put(wdev->netdev); 979 980 kfree(rdev->int_scan_req); 981 rdev->int_scan_req = NULL; 982 983 kfree(rdev->scan_req); 984 rdev->scan_req = NULL; 985 986 if (!send_message) 987 rdev->scan_msg = msg; 988 else 989 nl80211_send_scan_msg(rdev, msg); 990 } 991 992 void __cfg80211_scan_done(struct work_struct *wk) 993 { 994 struct cfg80211_registered_device *rdev; 995 996 rdev = container_of(wk, struct cfg80211_registered_device, 997 scan_done_wk); 998 999 wiphy_lock(&rdev->wiphy); 1000 ___cfg80211_scan_done(rdev, true); 1001 wiphy_unlock(&rdev->wiphy); 1002 } 1003 1004 void cfg80211_scan_done(struct cfg80211_scan_request *request, 1005 struct cfg80211_scan_info *info) 1006 { 1007 struct cfg80211_scan_info old_info = request->info; 1008 1009 trace_cfg80211_scan_done(request, info); 1010 WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req && 1011 request != wiphy_to_rdev(request->wiphy)->int_scan_req); 1012 1013 request->info = *info; 1014 1015 /* 1016 * In case the scan is split, the scan_start_tsf and tsf_bssid should 1017 * be of the first part. In such a case old_info.scan_start_tsf should 1018 * be non zero. 1019 */ 1020 if (request->scan_6ghz && old_info.scan_start_tsf) { 1021 request->info.scan_start_tsf = old_info.scan_start_tsf; 1022 memcpy(request->info.tsf_bssid, old_info.tsf_bssid, 1023 sizeof(request->info.tsf_bssid)); 1024 } 1025 1026 request->notified = true; 1027 queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk); 1028 } 1029 EXPORT_SYMBOL(cfg80211_scan_done); 1030 1031 void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev, 1032 struct cfg80211_sched_scan_request *req) 1033 { 1034 lockdep_assert_held(&rdev->wiphy.mtx); 1035 1036 list_add_rcu(&req->list, &rdev->sched_scan_req_list); 1037 } 1038 1039 static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev, 1040 struct cfg80211_sched_scan_request *req) 1041 { 1042 lockdep_assert_held(&rdev->wiphy.mtx); 1043 1044 list_del_rcu(&req->list); 1045 kfree_rcu(req, rcu_head); 1046 } 1047 1048 static struct cfg80211_sched_scan_request * 1049 cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid) 1050 { 1051 struct cfg80211_sched_scan_request *pos; 1052 1053 list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list, 1054 lockdep_is_held(&rdev->wiphy.mtx)) { 1055 if (pos->reqid == reqid) 1056 return pos; 1057 } 1058 return NULL; 1059 } 1060 1061 /* 1062 * Determines if a scheduled scan request can be handled. When a legacy 1063 * scheduled scan is running no other scheduled scan is allowed regardless 1064 * whether the request is for legacy or multi-support scan. When a multi-support 1065 * scheduled scan is running a request for legacy scan is not allowed. In this 1066 * case a request for multi-support scan can be handled if resources are 1067 * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached. 1068 */ 1069 int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev, 1070 bool want_multi) 1071 { 1072 struct cfg80211_sched_scan_request *pos; 1073 int i = 0; 1074 1075 list_for_each_entry(pos, &rdev->sched_scan_req_list, list) { 1076 /* request id zero means legacy in progress */ 1077 if (!i && !pos->reqid) 1078 return -EINPROGRESS; 1079 i++; 1080 } 1081 1082 if (i) { 1083 /* no legacy allowed when multi request(s) are active */ 1084 if (!want_multi) 1085 return -EINPROGRESS; 1086 1087 /* resource limit reached */ 1088 if (i == rdev->wiphy.max_sched_scan_reqs) 1089 return -ENOSPC; 1090 } 1091 return 0; 1092 } 1093 1094 void cfg80211_sched_scan_results_wk(struct work_struct *work) 1095 { 1096 struct cfg80211_registered_device *rdev; 1097 struct cfg80211_sched_scan_request *req, *tmp; 1098 1099 rdev = container_of(work, struct cfg80211_registered_device, 1100 sched_scan_res_wk); 1101 1102 wiphy_lock(&rdev->wiphy); 1103 list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) { 1104 if (req->report_results) { 1105 req->report_results = false; 1106 if (req->flags & NL80211_SCAN_FLAG_FLUSH) { 1107 /* flush entries from previous scans */ 1108 spin_lock_bh(&rdev->bss_lock); 1109 __cfg80211_bss_expire(rdev, req->scan_start); 1110 spin_unlock_bh(&rdev->bss_lock); 1111 req->scan_start = jiffies; 1112 } 1113 nl80211_send_sched_scan(req, 1114 NL80211_CMD_SCHED_SCAN_RESULTS); 1115 } 1116 } 1117 wiphy_unlock(&rdev->wiphy); 1118 } 1119 1120 void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid) 1121 { 1122 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1123 struct cfg80211_sched_scan_request *request; 1124 1125 trace_cfg80211_sched_scan_results(wiphy, reqid); 1126 /* ignore if we're not scanning */ 1127 1128 rcu_read_lock(); 1129 request = cfg80211_find_sched_scan_req(rdev, reqid); 1130 if (request) { 1131 request->report_results = true; 1132 queue_work(cfg80211_wq, &rdev->sched_scan_res_wk); 1133 } 1134 rcu_read_unlock(); 1135 } 1136 EXPORT_SYMBOL(cfg80211_sched_scan_results); 1137 1138 void cfg80211_sched_scan_stopped_locked(struct wiphy *wiphy, u64 reqid) 1139 { 1140 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1141 1142 lockdep_assert_held(&wiphy->mtx); 1143 1144 trace_cfg80211_sched_scan_stopped(wiphy, reqid); 1145 1146 __cfg80211_stop_sched_scan(rdev, reqid, true); 1147 } 1148 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_locked); 1149 1150 void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid) 1151 { 1152 wiphy_lock(wiphy); 1153 cfg80211_sched_scan_stopped_locked(wiphy, reqid); 1154 wiphy_unlock(wiphy); 1155 } 1156 EXPORT_SYMBOL(cfg80211_sched_scan_stopped); 1157 1158 int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev, 1159 struct cfg80211_sched_scan_request *req, 1160 bool driver_initiated) 1161 { 1162 lockdep_assert_held(&rdev->wiphy.mtx); 1163 1164 if (!driver_initiated) { 1165 int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid); 1166 if (err) 1167 return err; 1168 } 1169 1170 nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED); 1171 1172 cfg80211_del_sched_scan_req(rdev, req); 1173 1174 return 0; 1175 } 1176 1177 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, 1178 u64 reqid, bool driver_initiated) 1179 { 1180 struct cfg80211_sched_scan_request *sched_scan_req; 1181 1182 lockdep_assert_held(&rdev->wiphy.mtx); 1183 1184 sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid); 1185 if (!sched_scan_req) 1186 return -ENOENT; 1187 1188 return cfg80211_stop_sched_scan_req(rdev, sched_scan_req, 1189 driver_initiated); 1190 } 1191 1192 void cfg80211_bss_age(struct cfg80211_registered_device *rdev, 1193 unsigned long age_secs) 1194 { 1195 struct cfg80211_internal_bss *bss; 1196 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); 1197 1198 spin_lock_bh(&rdev->bss_lock); 1199 list_for_each_entry(bss, &rdev->bss_list, list) 1200 bss->ts -= age_jiffies; 1201 spin_unlock_bh(&rdev->bss_lock); 1202 } 1203 1204 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev) 1205 { 1206 __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); 1207 } 1208 1209 void cfg80211_bss_flush(struct wiphy *wiphy) 1210 { 1211 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1212 1213 spin_lock_bh(&rdev->bss_lock); 1214 __cfg80211_bss_expire(rdev, jiffies); 1215 spin_unlock_bh(&rdev->bss_lock); 1216 } 1217 EXPORT_SYMBOL(cfg80211_bss_flush); 1218 1219 const struct element * 1220 cfg80211_find_elem_match(u8 eid, const u8 *ies, unsigned int len, 1221 const u8 *match, unsigned int match_len, 1222 unsigned int match_offset) 1223 { 1224 const struct element *elem; 1225 1226 for_each_element_id(elem, eid, ies, len) { 1227 if (elem->datalen >= match_offset + match_len && 1228 !memcmp(elem->data + match_offset, match, match_len)) 1229 return elem; 1230 } 1231 1232 return NULL; 1233 } 1234 EXPORT_SYMBOL(cfg80211_find_elem_match); 1235 1236 const struct element *cfg80211_find_vendor_elem(unsigned int oui, int oui_type, 1237 const u8 *ies, 1238 unsigned int len) 1239 { 1240 const struct element *elem; 1241 u8 match[] = { oui >> 16, oui >> 8, oui, oui_type }; 1242 int match_len = (oui_type < 0) ? 3 : sizeof(match); 1243 1244 if (WARN_ON(oui_type > 0xff)) 1245 return NULL; 1246 1247 elem = cfg80211_find_elem_match(WLAN_EID_VENDOR_SPECIFIC, ies, len, 1248 match, match_len, 0); 1249 1250 if (!elem || elem->datalen < 4) 1251 return NULL; 1252 1253 return elem; 1254 } 1255 EXPORT_SYMBOL(cfg80211_find_vendor_elem); 1256 1257 /** 1258 * enum bss_compare_mode - BSS compare mode 1259 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) 1260 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode 1261 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode 1262 */ 1263 enum bss_compare_mode { 1264 BSS_CMP_REGULAR, 1265 BSS_CMP_HIDE_ZLEN, 1266 BSS_CMP_HIDE_NUL, 1267 }; 1268 1269 static int cmp_bss(struct cfg80211_bss *a, 1270 struct cfg80211_bss *b, 1271 enum bss_compare_mode mode) 1272 { 1273 const struct cfg80211_bss_ies *a_ies, *b_ies; 1274 const u8 *ie1 = NULL; 1275 const u8 *ie2 = NULL; 1276 int i, r; 1277 1278 if (a->channel != b->channel) 1279 return b->channel->center_freq - a->channel->center_freq; 1280 1281 a_ies = rcu_access_pointer(a->ies); 1282 if (!a_ies) 1283 return -1; 1284 b_ies = rcu_access_pointer(b->ies); 1285 if (!b_ies) 1286 return 1; 1287 1288 if (WLAN_CAPABILITY_IS_STA_BSS(a->capability)) 1289 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID, 1290 a_ies->data, a_ies->len); 1291 if (WLAN_CAPABILITY_IS_STA_BSS(b->capability)) 1292 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID, 1293 b_ies->data, b_ies->len); 1294 if (ie1 && ie2) { 1295 int mesh_id_cmp; 1296 1297 if (ie1[1] == ie2[1]) 1298 mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]); 1299 else 1300 mesh_id_cmp = ie2[1] - ie1[1]; 1301 1302 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 1303 a_ies->data, a_ies->len); 1304 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 1305 b_ies->data, b_ies->len); 1306 if (ie1 && ie2) { 1307 if (mesh_id_cmp) 1308 return mesh_id_cmp; 1309 if (ie1[1] != ie2[1]) 1310 return ie2[1] - ie1[1]; 1311 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 1312 } 1313 } 1314 1315 r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); 1316 if (r) 1317 return r; 1318 1319 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len); 1320 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len); 1321 1322 if (!ie1 && !ie2) 1323 return 0; 1324 1325 /* 1326 * Note that with "hide_ssid", the function returns a match if 1327 * the already-present BSS ("b") is a hidden SSID beacon for 1328 * the new BSS ("a"). 1329 */ 1330 1331 /* sort missing IE before (left of) present IE */ 1332 if (!ie1) 1333 return -1; 1334 if (!ie2) 1335 return 1; 1336 1337 switch (mode) { 1338 case BSS_CMP_HIDE_ZLEN: 1339 /* 1340 * In ZLEN mode we assume the BSS entry we're 1341 * looking for has a zero-length SSID. So if 1342 * the one we're looking at right now has that, 1343 * return 0. Otherwise, return the difference 1344 * in length, but since we're looking for the 1345 * 0-length it's really equivalent to returning 1346 * the length of the one we're looking at. 1347 * 1348 * No content comparison is needed as we assume 1349 * the content length is zero. 1350 */ 1351 return ie2[1]; 1352 case BSS_CMP_REGULAR: 1353 default: 1354 /* sort by length first, then by contents */ 1355 if (ie1[1] != ie2[1]) 1356 return ie2[1] - ie1[1]; 1357 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 1358 case BSS_CMP_HIDE_NUL: 1359 if (ie1[1] != ie2[1]) 1360 return ie2[1] - ie1[1]; 1361 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */ 1362 for (i = 0; i < ie2[1]; i++) 1363 if (ie2[i + 2]) 1364 return -1; 1365 return 0; 1366 } 1367 } 1368 1369 static bool cfg80211_bss_type_match(u16 capability, 1370 enum nl80211_band band, 1371 enum ieee80211_bss_type bss_type) 1372 { 1373 bool ret = true; 1374 u16 mask, val; 1375 1376 if (bss_type == IEEE80211_BSS_TYPE_ANY) 1377 return ret; 1378 1379 if (band == NL80211_BAND_60GHZ) { 1380 mask = WLAN_CAPABILITY_DMG_TYPE_MASK; 1381 switch (bss_type) { 1382 case IEEE80211_BSS_TYPE_ESS: 1383 val = WLAN_CAPABILITY_DMG_TYPE_AP; 1384 break; 1385 case IEEE80211_BSS_TYPE_PBSS: 1386 val = WLAN_CAPABILITY_DMG_TYPE_PBSS; 1387 break; 1388 case IEEE80211_BSS_TYPE_IBSS: 1389 val = WLAN_CAPABILITY_DMG_TYPE_IBSS; 1390 break; 1391 default: 1392 return false; 1393 } 1394 } else { 1395 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS; 1396 switch (bss_type) { 1397 case IEEE80211_BSS_TYPE_ESS: 1398 val = WLAN_CAPABILITY_ESS; 1399 break; 1400 case IEEE80211_BSS_TYPE_IBSS: 1401 val = WLAN_CAPABILITY_IBSS; 1402 break; 1403 case IEEE80211_BSS_TYPE_MBSS: 1404 val = 0; 1405 break; 1406 default: 1407 return false; 1408 } 1409 } 1410 1411 ret = ((capability & mask) == val); 1412 return ret; 1413 } 1414 1415 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1416 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, 1417 struct ieee80211_channel *channel, 1418 const u8 *bssid, 1419 const u8 *ssid, size_t ssid_len, 1420 enum ieee80211_bss_type bss_type, 1421 enum ieee80211_privacy privacy) 1422 { 1423 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1424 struct cfg80211_internal_bss *bss, *res = NULL; 1425 unsigned long now = jiffies; 1426 int bss_privacy; 1427 1428 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type, 1429 privacy); 1430 1431 spin_lock_bh(&rdev->bss_lock); 1432 1433 list_for_each_entry(bss, &rdev->bss_list, list) { 1434 if (!cfg80211_bss_type_match(bss->pub.capability, 1435 bss->pub.channel->band, bss_type)) 1436 continue; 1437 1438 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY); 1439 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) || 1440 (privacy == IEEE80211_PRIVACY_OFF && bss_privacy)) 1441 continue; 1442 if (channel && bss->pub.channel != channel) 1443 continue; 1444 if (!is_valid_ether_addr(bss->pub.bssid)) 1445 continue; 1446 /* Don't get expired BSS structs */ 1447 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && 1448 !atomic_read(&bss->hold)) 1449 continue; 1450 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { 1451 res = bss; 1452 bss_ref_get(rdev, res); 1453 break; 1454 } 1455 } 1456 1457 spin_unlock_bh(&rdev->bss_lock); 1458 if (!res) 1459 return NULL; 1460 trace_cfg80211_return_bss(&res->pub); 1461 return &res->pub; 1462 } 1463 EXPORT_SYMBOL(cfg80211_get_bss); 1464 1465 static void rb_insert_bss(struct cfg80211_registered_device *rdev, 1466 struct cfg80211_internal_bss *bss) 1467 { 1468 struct rb_node **p = &rdev->bss_tree.rb_node; 1469 struct rb_node *parent = NULL; 1470 struct cfg80211_internal_bss *tbss; 1471 int cmp; 1472 1473 while (*p) { 1474 parent = *p; 1475 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); 1476 1477 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR); 1478 1479 if (WARN_ON(!cmp)) { 1480 /* will sort of leak this BSS */ 1481 return; 1482 } 1483 1484 if (cmp < 0) 1485 p = &(*p)->rb_left; 1486 else 1487 p = &(*p)->rb_right; 1488 } 1489 1490 rb_link_node(&bss->rbn, parent, p); 1491 rb_insert_color(&bss->rbn, &rdev->bss_tree); 1492 } 1493 1494 static struct cfg80211_internal_bss * 1495 rb_find_bss(struct cfg80211_registered_device *rdev, 1496 struct cfg80211_internal_bss *res, 1497 enum bss_compare_mode mode) 1498 { 1499 struct rb_node *n = rdev->bss_tree.rb_node; 1500 struct cfg80211_internal_bss *bss; 1501 int r; 1502 1503 while (n) { 1504 bss = rb_entry(n, struct cfg80211_internal_bss, rbn); 1505 r = cmp_bss(&res->pub, &bss->pub, mode); 1506 1507 if (r == 0) 1508 return bss; 1509 else if (r < 0) 1510 n = n->rb_left; 1511 else 1512 n = n->rb_right; 1513 } 1514 1515 return NULL; 1516 } 1517 1518 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, 1519 struct cfg80211_internal_bss *new) 1520 { 1521 const struct cfg80211_bss_ies *ies; 1522 struct cfg80211_internal_bss *bss; 1523 const u8 *ie; 1524 int i, ssidlen; 1525 u8 fold = 0; 1526 u32 n_entries = 0; 1527 1528 ies = rcu_access_pointer(new->pub.beacon_ies); 1529 if (WARN_ON(!ies)) 1530 return false; 1531 1532 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 1533 if (!ie) { 1534 /* nothing to do */ 1535 return true; 1536 } 1537 1538 ssidlen = ie[1]; 1539 for (i = 0; i < ssidlen; i++) 1540 fold |= ie[2 + i]; 1541 1542 if (fold) { 1543 /* not a hidden SSID */ 1544 return true; 1545 } 1546 1547 /* This is the bad part ... */ 1548 1549 list_for_each_entry(bss, &rdev->bss_list, list) { 1550 /* 1551 * we're iterating all the entries anyway, so take the 1552 * opportunity to validate the list length accounting 1553 */ 1554 n_entries++; 1555 1556 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) 1557 continue; 1558 if (bss->pub.channel != new->pub.channel) 1559 continue; 1560 if (bss->pub.scan_width != new->pub.scan_width) 1561 continue; 1562 if (rcu_access_pointer(bss->pub.beacon_ies)) 1563 continue; 1564 ies = rcu_access_pointer(bss->pub.ies); 1565 if (!ies) 1566 continue; 1567 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 1568 if (!ie) 1569 continue; 1570 if (ssidlen && ie[1] != ssidlen) 1571 continue; 1572 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss)) 1573 continue; 1574 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list))) 1575 list_del(&bss->hidden_list); 1576 /* combine them */ 1577 list_add(&bss->hidden_list, &new->hidden_list); 1578 bss->pub.hidden_beacon_bss = &new->pub; 1579 new->refcount += bss->refcount; 1580 rcu_assign_pointer(bss->pub.beacon_ies, 1581 new->pub.beacon_ies); 1582 } 1583 1584 WARN_ONCE(n_entries != rdev->bss_entries, 1585 "rdev bss entries[%d]/list[len:%d] corruption\n", 1586 rdev->bss_entries, n_entries); 1587 1588 return true; 1589 } 1590 1591 struct cfg80211_non_tx_bss { 1592 struct cfg80211_bss *tx_bss; 1593 u8 max_bssid_indicator; 1594 u8 bssid_index; 1595 }; 1596 1597 static bool 1598 cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, 1599 struct cfg80211_internal_bss *known, 1600 struct cfg80211_internal_bss *new, 1601 bool signal_valid) 1602 { 1603 lockdep_assert_held(&rdev->bss_lock); 1604 1605 /* Update IEs */ 1606 if (rcu_access_pointer(new->pub.proberesp_ies)) { 1607 const struct cfg80211_bss_ies *old; 1608 1609 old = rcu_access_pointer(known->pub.proberesp_ies); 1610 1611 rcu_assign_pointer(known->pub.proberesp_ies, 1612 new->pub.proberesp_ies); 1613 /* Override possible earlier Beacon frame IEs */ 1614 rcu_assign_pointer(known->pub.ies, 1615 new->pub.proberesp_ies); 1616 if (old) 1617 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1618 } else if (rcu_access_pointer(new->pub.beacon_ies)) { 1619 const struct cfg80211_bss_ies *old; 1620 struct cfg80211_internal_bss *bss; 1621 1622 if (known->pub.hidden_beacon_bss && 1623 !list_empty(&known->hidden_list)) { 1624 const struct cfg80211_bss_ies *f; 1625 1626 /* The known BSS struct is one of the probe 1627 * response members of a group, but we're 1628 * receiving a beacon (beacon_ies in the new 1629 * bss is used). This can only mean that the 1630 * AP changed its beacon from not having an 1631 * SSID to showing it, which is confusing so 1632 * drop this information. 1633 */ 1634 1635 f = rcu_access_pointer(new->pub.beacon_ies); 1636 kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head); 1637 return false; 1638 } 1639 1640 old = rcu_access_pointer(known->pub.beacon_ies); 1641 1642 rcu_assign_pointer(known->pub.beacon_ies, new->pub.beacon_ies); 1643 1644 /* Override IEs if they were from a beacon before */ 1645 if (old == rcu_access_pointer(known->pub.ies)) 1646 rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies); 1647 1648 /* Assign beacon IEs to all sub entries */ 1649 list_for_each_entry(bss, &known->hidden_list, hidden_list) { 1650 const struct cfg80211_bss_ies *ies; 1651 1652 ies = rcu_access_pointer(bss->pub.beacon_ies); 1653 WARN_ON(ies != old); 1654 1655 rcu_assign_pointer(bss->pub.beacon_ies, 1656 new->pub.beacon_ies); 1657 } 1658 1659 if (old) 1660 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 1661 } 1662 1663 known->pub.beacon_interval = new->pub.beacon_interval; 1664 1665 /* don't update the signal if beacon was heard on 1666 * adjacent channel. 1667 */ 1668 if (signal_valid) 1669 known->pub.signal = new->pub.signal; 1670 known->pub.capability = new->pub.capability; 1671 known->ts = new->ts; 1672 known->ts_boottime = new->ts_boottime; 1673 known->parent_tsf = new->parent_tsf; 1674 known->pub.chains = new->pub.chains; 1675 memcpy(known->pub.chain_signal, new->pub.chain_signal, 1676 IEEE80211_MAX_CHAINS); 1677 ether_addr_copy(known->parent_bssid, new->parent_bssid); 1678 known->pub.max_bssid_indicator = new->pub.max_bssid_indicator; 1679 known->pub.bssid_index = new->pub.bssid_index; 1680 1681 return true; 1682 } 1683 1684 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1685 struct cfg80211_internal_bss * 1686 cfg80211_bss_update(struct cfg80211_registered_device *rdev, 1687 struct cfg80211_internal_bss *tmp, 1688 bool signal_valid, unsigned long ts) 1689 { 1690 struct cfg80211_internal_bss *found = NULL; 1691 1692 if (WARN_ON(!tmp->pub.channel)) 1693 return NULL; 1694 1695 tmp->ts = ts; 1696 1697 spin_lock_bh(&rdev->bss_lock); 1698 1699 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) { 1700 spin_unlock_bh(&rdev->bss_lock); 1701 return NULL; 1702 } 1703 1704 found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR); 1705 1706 if (found) { 1707 if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid)) 1708 goto drop; 1709 } else { 1710 struct cfg80211_internal_bss *new; 1711 struct cfg80211_internal_bss *hidden; 1712 struct cfg80211_bss_ies *ies; 1713 1714 /* 1715 * create a copy -- the "res" variable that is passed in 1716 * is allocated on the stack since it's not needed in the 1717 * more common case of an update 1718 */ 1719 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size, 1720 GFP_ATOMIC); 1721 if (!new) { 1722 ies = (void *)rcu_dereference(tmp->pub.beacon_ies); 1723 if (ies) 1724 kfree_rcu(ies, rcu_head); 1725 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies); 1726 if (ies) 1727 kfree_rcu(ies, rcu_head); 1728 goto drop; 1729 } 1730 memcpy(new, tmp, sizeof(*new)); 1731 new->refcount = 1; 1732 INIT_LIST_HEAD(&new->hidden_list); 1733 INIT_LIST_HEAD(&new->pub.nontrans_list); 1734 1735 if (rcu_access_pointer(tmp->pub.proberesp_ies)) { 1736 hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); 1737 if (!hidden) 1738 hidden = rb_find_bss(rdev, tmp, 1739 BSS_CMP_HIDE_NUL); 1740 if (hidden) { 1741 new->pub.hidden_beacon_bss = &hidden->pub; 1742 list_add(&new->hidden_list, 1743 &hidden->hidden_list); 1744 hidden->refcount++; 1745 rcu_assign_pointer(new->pub.beacon_ies, 1746 hidden->pub.beacon_ies); 1747 } 1748 } else { 1749 /* 1750 * Ok so we found a beacon, and don't have an entry. If 1751 * it's a beacon with hidden SSID, we might be in for an 1752 * expensive search for any probe responses that should 1753 * be grouped with this beacon for updates ... 1754 */ 1755 if (!cfg80211_combine_bsses(rdev, new)) { 1756 bss_ref_put(rdev, new); 1757 goto drop; 1758 } 1759 } 1760 1761 if (rdev->bss_entries >= bss_entries_limit && 1762 !cfg80211_bss_expire_oldest(rdev)) { 1763 bss_ref_put(rdev, new); 1764 goto drop; 1765 } 1766 1767 /* This must be before the call to bss_ref_get */ 1768 if (tmp->pub.transmitted_bss) { 1769 struct cfg80211_internal_bss *pbss = 1770 container_of(tmp->pub.transmitted_bss, 1771 struct cfg80211_internal_bss, 1772 pub); 1773 1774 new->pub.transmitted_bss = tmp->pub.transmitted_bss; 1775 bss_ref_get(rdev, pbss); 1776 } 1777 1778 list_add_tail(&new->list, &rdev->bss_list); 1779 rdev->bss_entries++; 1780 rb_insert_bss(rdev, new); 1781 found = new; 1782 } 1783 1784 rdev->bss_generation++; 1785 bss_ref_get(rdev, found); 1786 spin_unlock_bh(&rdev->bss_lock); 1787 1788 return found; 1789 drop: 1790 spin_unlock_bh(&rdev->bss_lock); 1791 return NULL; 1792 } 1793 1794 int cfg80211_get_ies_channel_number(const u8 *ie, size_t ielen, 1795 enum nl80211_band band) 1796 { 1797 const u8 *tmp; 1798 int channel_number = -1; 1799 1800 if (band == NL80211_BAND_S1GHZ) { 1801 tmp = cfg80211_find_ie(WLAN_EID_S1G_OPERATION, ie, ielen); 1802 if (tmp && tmp[1] >= sizeof(struct ieee80211_s1g_oper_ie)) { 1803 struct ieee80211_s1g_oper_ie *s1gop = (void *)(tmp + 2); 1804 1805 channel_number = s1gop->primary_ch; 1806 } 1807 } else { 1808 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen); 1809 if (tmp && tmp[1] == 1) { 1810 channel_number = tmp[2]; 1811 } else { 1812 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen); 1813 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) { 1814 struct ieee80211_ht_operation *htop = (void *)(tmp + 2); 1815 1816 channel_number = htop->primary_chan; 1817 } 1818 } 1819 } 1820 1821 return channel_number; 1822 } 1823 EXPORT_SYMBOL(cfg80211_get_ies_channel_number); 1824 1825 /* 1826 * Update RX channel information based on the available frame payload 1827 * information. This is mainly for the 2.4 GHz band where frames can be received 1828 * from neighboring channels and the Beacon frames use the DSSS Parameter Set 1829 * element to indicate the current (transmitting) channel, but this might also 1830 * be needed on other bands if RX frequency does not match with the actual 1831 * operating channel of a BSS. 1832 */ 1833 static struct ieee80211_channel * 1834 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, 1835 struct ieee80211_channel *channel, 1836 enum nl80211_bss_scan_width scan_width) 1837 { 1838 u32 freq; 1839 int channel_number; 1840 struct ieee80211_channel *alt_channel; 1841 1842 channel_number = cfg80211_get_ies_channel_number(ie, ielen, channel->band); 1843 1844 if (channel_number < 0) { 1845 /* No channel information in frame payload */ 1846 return channel; 1847 } 1848 1849 freq = ieee80211_channel_to_freq_khz(channel_number, channel->band); 1850 alt_channel = ieee80211_get_channel_khz(wiphy, freq); 1851 if (!alt_channel) { 1852 if (channel->band == NL80211_BAND_2GHZ) { 1853 /* 1854 * Better not allow unexpected channels when that could 1855 * be going beyond the 1-11 range (e.g., discovering 1856 * BSS on channel 12 when radio is configured for 1857 * channel 11. 1858 */ 1859 return NULL; 1860 } 1861 1862 /* No match for the payload channel number - ignore it */ 1863 return channel; 1864 } 1865 1866 if (scan_width == NL80211_BSS_CHAN_WIDTH_10 || 1867 scan_width == NL80211_BSS_CHAN_WIDTH_5) { 1868 /* 1869 * Ignore channel number in 5 and 10 MHz channels where there 1870 * may not be an n:1 or 1:n mapping between frequencies and 1871 * channel numbers. 1872 */ 1873 return channel; 1874 } 1875 1876 /* 1877 * Use the channel determined through the payload channel number 1878 * instead of the RX channel reported by the driver. 1879 */ 1880 if (alt_channel->flags & IEEE80211_CHAN_DISABLED) 1881 return NULL; 1882 return alt_channel; 1883 } 1884 1885 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1886 static struct cfg80211_bss * 1887 cfg80211_inform_single_bss_data(struct wiphy *wiphy, 1888 struct cfg80211_inform_bss *data, 1889 enum cfg80211_bss_frame_type ftype, 1890 const u8 *bssid, u64 tsf, u16 capability, 1891 u16 beacon_interval, const u8 *ie, size_t ielen, 1892 struct cfg80211_non_tx_bss *non_tx_data, 1893 gfp_t gfp) 1894 { 1895 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1896 struct cfg80211_bss_ies *ies; 1897 struct ieee80211_channel *channel; 1898 struct cfg80211_internal_bss tmp = {}, *res; 1899 int bss_type; 1900 bool signal_valid; 1901 unsigned long ts; 1902 1903 if (WARN_ON(!wiphy)) 1904 return NULL; 1905 1906 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 1907 (data->signal < 0 || data->signal > 100))) 1908 return NULL; 1909 1910 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan, 1911 data->scan_width); 1912 if (!channel) 1913 return NULL; 1914 1915 memcpy(tmp.pub.bssid, bssid, ETH_ALEN); 1916 tmp.pub.channel = channel; 1917 tmp.pub.scan_width = data->scan_width; 1918 tmp.pub.signal = data->signal; 1919 tmp.pub.beacon_interval = beacon_interval; 1920 tmp.pub.capability = capability; 1921 tmp.ts_boottime = data->boottime_ns; 1922 tmp.parent_tsf = data->parent_tsf; 1923 ether_addr_copy(tmp.parent_bssid, data->parent_bssid); 1924 1925 if (non_tx_data) { 1926 tmp.pub.transmitted_bss = non_tx_data->tx_bss; 1927 ts = bss_from_pub(non_tx_data->tx_bss)->ts; 1928 tmp.pub.bssid_index = non_tx_data->bssid_index; 1929 tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; 1930 } else { 1931 ts = jiffies; 1932 } 1933 1934 /* 1935 * If we do not know here whether the IEs are from a Beacon or Probe 1936 * Response frame, we need to pick one of the options and only use it 1937 * with the driver that does not provide the full Beacon/Probe Response 1938 * frame. Use Beacon frame pointer to avoid indicating that this should 1939 * override the IEs pointer should we have received an earlier 1940 * indication of Probe Response data. 1941 */ 1942 ies = kzalloc(sizeof(*ies) + ielen, gfp); 1943 if (!ies) 1944 return NULL; 1945 ies->len = ielen; 1946 ies->tsf = tsf; 1947 ies->from_beacon = false; 1948 memcpy(ies->data, ie, ielen); 1949 1950 switch (ftype) { 1951 case CFG80211_BSS_FTYPE_BEACON: 1952 ies->from_beacon = true; 1953 fallthrough; 1954 case CFG80211_BSS_FTYPE_UNKNOWN: 1955 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 1956 break; 1957 case CFG80211_BSS_FTYPE_PRESP: 1958 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 1959 break; 1960 } 1961 rcu_assign_pointer(tmp.pub.ies, ies); 1962 1963 signal_valid = data->chan == channel; 1964 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts); 1965 if (!res) 1966 return NULL; 1967 1968 if (channel->band == NL80211_BAND_60GHZ) { 1969 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 1970 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 1971 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 1972 regulatory_hint_found_beacon(wiphy, channel, gfp); 1973 } else { 1974 if (res->pub.capability & WLAN_CAPABILITY_ESS) 1975 regulatory_hint_found_beacon(wiphy, channel, gfp); 1976 } 1977 1978 if (non_tx_data) { 1979 /* this is a nontransmitting bss, we need to add it to 1980 * transmitting bss' list if it is not there 1981 */ 1982 if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, 1983 &res->pub)) { 1984 if (__cfg80211_unlink_bss(rdev, res)) 1985 rdev->bss_generation++; 1986 } 1987 } 1988 1989 trace_cfg80211_return_bss(&res->pub); 1990 /* cfg80211_bss_update gives us a referenced result */ 1991 return &res->pub; 1992 } 1993 1994 static const struct element 1995 *cfg80211_get_profile_continuation(const u8 *ie, size_t ielen, 1996 const struct element *mbssid_elem, 1997 const struct element *sub_elem) 1998 { 1999 const u8 *mbssid_end = mbssid_elem->data + mbssid_elem->datalen; 2000 const struct element *next_mbssid; 2001 const struct element *next_sub; 2002 2003 next_mbssid = cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID, 2004 mbssid_end, 2005 ielen - (mbssid_end - ie)); 2006 2007 /* 2008 * If it is not the last subelement in current MBSSID IE or there isn't 2009 * a next MBSSID IE - profile is complete. 2010 */ 2011 if ((sub_elem->data + sub_elem->datalen < mbssid_end - 1) || 2012 !next_mbssid) 2013 return NULL; 2014 2015 /* For any length error, just return NULL */ 2016 2017 if (next_mbssid->datalen < 4) 2018 return NULL; 2019 2020 next_sub = (void *)&next_mbssid->data[1]; 2021 2022 if (next_mbssid->data + next_mbssid->datalen < 2023 next_sub->data + next_sub->datalen) 2024 return NULL; 2025 2026 if (next_sub->id != 0 || next_sub->datalen < 2) 2027 return NULL; 2028 2029 /* 2030 * Check if the first element in the next sub element is a start 2031 * of a new profile 2032 */ 2033 return next_sub->data[0] == WLAN_EID_NON_TX_BSSID_CAP ? 2034 NULL : next_mbssid; 2035 } 2036 2037 size_t cfg80211_merge_profile(const u8 *ie, size_t ielen, 2038 const struct element *mbssid_elem, 2039 const struct element *sub_elem, 2040 u8 *merged_ie, size_t max_copy_len) 2041 { 2042 size_t copied_len = sub_elem->datalen; 2043 const struct element *next_mbssid; 2044 2045 if (sub_elem->datalen > max_copy_len) 2046 return 0; 2047 2048 memcpy(merged_ie, sub_elem->data, sub_elem->datalen); 2049 2050 while ((next_mbssid = cfg80211_get_profile_continuation(ie, ielen, 2051 mbssid_elem, 2052 sub_elem))) { 2053 const struct element *next_sub = (void *)&next_mbssid->data[1]; 2054 2055 if (copied_len + next_sub->datalen > max_copy_len) 2056 break; 2057 memcpy(merged_ie + copied_len, next_sub->data, 2058 next_sub->datalen); 2059 copied_len += next_sub->datalen; 2060 } 2061 2062 return copied_len; 2063 } 2064 EXPORT_SYMBOL(cfg80211_merge_profile); 2065 2066 static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, 2067 struct cfg80211_inform_bss *data, 2068 enum cfg80211_bss_frame_type ftype, 2069 const u8 *bssid, u64 tsf, 2070 u16 beacon_interval, const u8 *ie, 2071 size_t ielen, 2072 struct cfg80211_non_tx_bss *non_tx_data, 2073 gfp_t gfp) 2074 { 2075 const u8 *mbssid_index_ie; 2076 const struct element *elem, *sub; 2077 size_t new_ie_len; 2078 u8 new_bssid[ETH_ALEN]; 2079 u8 *new_ie, *profile; 2080 u64 seen_indices = 0; 2081 u16 capability; 2082 struct cfg80211_bss *bss; 2083 2084 if (!non_tx_data) 2085 return; 2086 if (!cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) 2087 return; 2088 if (!wiphy->support_mbssid) 2089 return; 2090 if (wiphy->support_only_he_mbssid && 2091 !cfg80211_find_ext_elem(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) 2092 return; 2093 2094 new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp); 2095 if (!new_ie) 2096 return; 2097 2098 profile = kmalloc(ielen, gfp); 2099 if (!profile) 2100 goto out; 2101 2102 for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) { 2103 if (elem->datalen < 4) 2104 continue; 2105 for_each_element(sub, elem->data + 1, elem->datalen - 1) { 2106 u8 profile_len; 2107 2108 if (sub->id != 0 || sub->datalen < 4) { 2109 /* not a valid BSS profile */ 2110 continue; 2111 } 2112 2113 if (sub->data[0] != WLAN_EID_NON_TX_BSSID_CAP || 2114 sub->data[1] != 2) { 2115 /* The first element within the Nontransmitted 2116 * BSSID Profile is not the Nontransmitted 2117 * BSSID Capability element. 2118 */ 2119 continue; 2120 } 2121 2122 memset(profile, 0, ielen); 2123 profile_len = cfg80211_merge_profile(ie, ielen, 2124 elem, 2125 sub, 2126 profile, 2127 ielen); 2128 2129 /* found a Nontransmitted BSSID Profile */ 2130 mbssid_index_ie = cfg80211_find_ie 2131 (WLAN_EID_MULTI_BSSID_IDX, 2132 profile, profile_len); 2133 if (!mbssid_index_ie || mbssid_index_ie[1] < 1 || 2134 mbssid_index_ie[2] == 0 || 2135 mbssid_index_ie[2] > 46) { 2136 /* No valid Multiple BSSID-Index element */ 2137 continue; 2138 } 2139 2140 if (seen_indices & BIT_ULL(mbssid_index_ie[2])) 2141 /* We don't support legacy split of a profile */ 2142 net_dbg_ratelimited("Partial info for BSSID index %d\n", 2143 mbssid_index_ie[2]); 2144 2145 seen_indices |= BIT_ULL(mbssid_index_ie[2]); 2146 2147 non_tx_data->bssid_index = mbssid_index_ie[2]; 2148 non_tx_data->max_bssid_indicator = elem->data[0]; 2149 2150 cfg80211_gen_new_bssid(bssid, 2151 non_tx_data->max_bssid_indicator, 2152 non_tx_data->bssid_index, 2153 new_bssid); 2154 memset(new_ie, 0, IEEE80211_MAX_DATA_LEN); 2155 new_ie_len = cfg80211_gen_new_ie(ie, ielen, 2156 profile, 2157 profile_len, new_ie, 2158 gfp); 2159 if (!new_ie_len) 2160 continue; 2161 2162 capability = get_unaligned_le16(profile + 2); 2163 bss = cfg80211_inform_single_bss_data(wiphy, data, 2164 ftype, 2165 new_bssid, tsf, 2166 capability, 2167 beacon_interval, 2168 new_ie, 2169 new_ie_len, 2170 non_tx_data, 2171 gfp); 2172 if (!bss) 2173 break; 2174 cfg80211_put_bss(wiphy, bss); 2175 } 2176 } 2177 2178 out: 2179 kfree(new_ie); 2180 kfree(profile); 2181 } 2182 2183 struct cfg80211_bss * 2184 cfg80211_inform_bss_data(struct wiphy *wiphy, 2185 struct cfg80211_inform_bss *data, 2186 enum cfg80211_bss_frame_type ftype, 2187 const u8 *bssid, u64 tsf, u16 capability, 2188 u16 beacon_interval, const u8 *ie, size_t ielen, 2189 gfp_t gfp) 2190 { 2191 struct cfg80211_bss *res; 2192 struct cfg80211_non_tx_bss non_tx_data; 2193 2194 res = cfg80211_inform_single_bss_data(wiphy, data, ftype, bssid, tsf, 2195 capability, beacon_interval, ie, 2196 ielen, NULL, gfp); 2197 if (!res) 2198 return NULL; 2199 non_tx_data.tx_bss = res; 2200 cfg80211_parse_mbssid_data(wiphy, data, ftype, bssid, tsf, 2201 beacon_interval, ie, ielen, &non_tx_data, 2202 gfp); 2203 return res; 2204 } 2205 EXPORT_SYMBOL(cfg80211_inform_bss_data); 2206 2207 static void 2208 cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy, 2209 struct cfg80211_inform_bss *data, 2210 struct ieee80211_mgmt *mgmt, size_t len, 2211 struct cfg80211_non_tx_bss *non_tx_data, 2212 gfp_t gfp) 2213 { 2214 enum cfg80211_bss_frame_type ftype; 2215 const u8 *ie = mgmt->u.probe_resp.variable; 2216 size_t ielen = len - offsetof(struct ieee80211_mgmt, 2217 u.probe_resp.variable); 2218 2219 ftype = ieee80211_is_beacon(mgmt->frame_control) ? 2220 CFG80211_BSS_FTYPE_BEACON : CFG80211_BSS_FTYPE_PRESP; 2221 2222 cfg80211_parse_mbssid_data(wiphy, data, ftype, mgmt->bssid, 2223 le64_to_cpu(mgmt->u.probe_resp.timestamp), 2224 le16_to_cpu(mgmt->u.probe_resp.beacon_int), 2225 ie, ielen, non_tx_data, gfp); 2226 } 2227 2228 static void 2229 cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, 2230 struct cfg80211_bss *nontrans_bss, 2231 struct ieee80211_mgmt *mgmt, size_t len) 2232 { 2233 u8 *ie, *new_ie, *pos; 2234 const u8 *nontrans_ssid, *trans_ssid, *mbssid; 2235 size_t ielen = len - offsetof(struct ieee80211_mgmt, 2236 u.probe_resp.variable); 2237 size_t new_ie_len; 2238 struct cfg80211_bss_ies *new_ies; 2239 const struct cfg80211_bss_ies *old; 2240 u8 cpy_len; 2241 2242 lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock); 2243 2244 ie = mgmt->u.probe_resp.variable; 2245 2246 new_ie_len = ielen; 2247 trans_ssid = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); 2248 if (!trans_ssid) 2249 return; 2250 new_ie_len -= trans_ssid[1]; 2251 mbssid = cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen); 2252 /* 2253 * It's not valid to have the MBSSID element before SSID 2254 * ignore if that happens - the code below assumes it is 2255 * after (while copying things inbetween). 2256 */ 2257 if (!mbssid || mbssid < trans_ssid) 2258 return; 2259 new_ie_len -= mbssid[1]; 2260 2261 nontrans_ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); 2262 if (!nontrans_ssid) 2263 return; 2264 2265 new_ie_len += nontrans_ssid[1]; 2266 2267 /* generate new ie for nontrans BSS 2268 * 1. replace SSID with nontrans BSS' SSID 2269 * 2. skip MBSSID IE 2270 */ 2271 new_ie = kzalloc(new_ie_len, GFP_ATOMIC); 2272 if (!new_ie) 2273 return; 2274 2275 new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC); 2276 if (!new_ies) 2277 goto out_free; 2278 2279 pos = new_ie; 2280 2281 /* copy the nontransmitted SSID */ 2282 cpy_len = nontrans_ssid[1] + 2; 2283 memcpy(pos, nontrans_ssid, cpy_len); 2284 pos += cpy_len; 2285 /* copy the IEs between SSID and MBSSID */ 2286 cpy_len = trans_ssid[1] + 2; 2287 memcpy(pos, (trans_ssid + cpy_len), (mbssid - (trans_ssid + cpy_len))); 2288 pos += (mbssid - (trans_ssid + cpy_len)); 2289 /* copy the IEs after MBSSID */ 2290 cpy_len = mbssid[1] + 2; 2291 memcpy(pos, mbssid + cpy_len, ((ie + ielen) - (mbssid + cpy_len))); 2292 2293 /* update ie */ 2294 new_ies->len = new_ie_len; 2295 new_ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 2296 new_ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); 2297 memcpy(new_ies->data, new_ie, new_ie_len); 2298 if (ieee80211_is_probe_resp(mgmt->frame_control)) { 2299 old = rcu_access_pointer(nontrans_bss->proberesp_ies); 2300 rcu_assign_pointer(nontrans_bss->proberesp_ies, new_ies); 2301 rcu_assign_pointer(nontrans_bss->ies, new_ies); 2302 if (old) 2303 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 2304 } else { 2305 old = rcu_access_pointer(nontrans_bss->beacon_ies); 2306 rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies); 2307 rcu_assign_pointer(nontrans_bss->ies, new_ies); 2308 if (old) 2309 kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); 2310 } 2311 2312 out_free: 2313 kfree(new_ie); 2314 } 2315 2316 /* cfg80211_inform_bss_width_frame helper */ 2317 static struct cfg80211_bss * 2318 cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, 2319 struct cfg80211_inform_bss *data, 2320 struct ieee80211_mgmt *mgmt, size_t len, 2321 gfp_t gfp) 2322 { 2323 struct cfg80211_internal_bss tmp = {}, *res; 2324 struct cfg80211_bss_ies *ies; 2325 struct ieee80211_channel *channel; 2326 bool signal_valid; 2327 struct ieee80211_ext *ext = NULL; 2328 u8 *bssid, *variable; 2329 u16 capability, beacon_int; 2330 size_t ielen, min_hdr_len = offsetof(struct ieee80211_mgmt, 2331 u.probe_resp.variable); 2332 int bss_type; 2333 2334 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) != 2335 offsetof(struct ieee80211_mgmt, u.beacon.variable)); 2336 2337 trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len); 2338 2339 if (WARN_ON(!mgmt)) 2340 return NULL; 2341 2342 if (WARN_ON(!wiphy)) 2343 return NULL; 2344 2345 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 2346 (data->signal < 0 || data->signal > 100))) 2347 return NULL; 2348 2349 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) { 2350 ext = (void *) mgmt; 2351 min_hdr_len = offsetof(struct ieee80211_ext, u.s1g_beacon); 2352 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control)) 2353 min_hdr_len = offsetof(struct ieee80211_ext, 2354 u.s1g_short_beacon.variable); 2355 } 2356 2357 if (WARN_ON(len < min_hdr_len)) 2358 return NULL; 2359 2360 ielen = len - min_hdr_len; 2361 variable = mgmt->u.probe_resp.variable; 2362 if (ext) { 2363 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control)) 2364 variable = ext->u.s1g_short_beacon.variable; 2365 else 2366 variable = ext->u.s1g_beacon.variable; 2367 } 2368 2369 channel = cfg80211_get_bss_channel(wiphy, variable, 2370 ielen, data->chan, data->scan_width); 2371 if (!channel) 2372 return NULL; 2373 2374 if (ext) { 2375 const struct ieee80211_s1g_bcn_compat_ie *compat; 2376 const struct element *elem; 2377 2378 elem = cfg80211_find_elem(WLAN_EID_S1G_BCN_COMPAT, 2379 variable, ielen); 2380 if (!elem) 2381 return NULL; 2382 if (elem->datalen < sizeof(*compat)) 2383 return NULL; 2384 compat = (void *)elem->data; 2385 bssid = ext->u.s1g_beacon.sa; 2386 capability = le16_to_cpu(compat->compat_info); 2387 beacon_int = le16_to_cpu(compat->beacon_int); 2388 } else { 2389 bssid = mgmt->bssid; 2390 beacon_int = le16_to_cpu(mgmt->u.probe_resp.beacon_int); 2391 capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); 2392 } 2393 2394 ies = kzalloc(sizeof(*ies) + ielen, gfp); 2395 if (!ies) 2396 return NULL; 2397 ies->len = ielen; 2398 ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 2399 ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control) || 2400 ieee80211_is_s1g_beacon(mgmt->frame_control); 2401 memcpy(ies->data, variable, ielen); 2402 2403 if (ieee80211_is_probe_resp(mgmt->frame_control)) 2404 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 2405 else 2406 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 2407 rcu_assign_pointer(tmp.pub.ies, ies); 2408 2409 memcpy(tmp.pub.bssid, bssid, ETH_ALEN); 2410 tmp.pub.beacon_interval = beacon_int; 2411 tmp.pub.capability = capability; 2412 tmp.pub.channel = channel; 2413 tmp.pub.scan_width = data->scan_width; 2414 tmp.pub.signal = data->signal; 2415 tmp.ts_boottime = data->boottime_ns; 2416 tmp.parent_tsf = data->parent_tsf; 2417 tmp.pub.chains = data->chains; 2418 memcpy(tmp.pub.chain_signal, data->chain_signal, IEEE80211_MAX_CHAINS); 2419 ether_addr_copy(tmp.parent_bssid, data->parent_bssid); 2420 2421 signal_valid = data->chan == channel; 2422 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, 2423 jiffies); 2424 if (!res) 2425 return NULL; 2426 2427 if (channel->band == NL80211_BAND_60GHZ) { 2428 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 2429 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 2430 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 2431 regulatory_hint_found_beacon(wiphy, channel, gfp); 2432 } else { 2433 if (res->pub.capability & WLAN_CAPABILITY_ESS) 2434 regulatory_hint_found_beacon(wiphy, channel, gfp); 2435 } 2436 2437 trace_cfg80211_return_bss(&res->pub); 2438 /* cfg80211_bss_update gives us a referenced result */ 2439 return &res->pub; 2440 } 2441 2442 struct cfg80211_bss * 2443 cfg80211_inform_bss_frame_data(struct wiphy *wiphy, 2444 struct cfg80211_inform_bss *data, 2445 struct ieee80211_mgmt *mgmt, size_t len, 2446 gfp_t gfp) 2447 { 2448 struct cfg80211_bss *res, *tmp_bss; 2449 const u8 *ie = mgmt->u.probe_resp.variable; 2450 const struct cfg80211_bss_ies *ies1, *ies2; 2451 size_t ielen = len - offsetof(struct ieee80211_mgmt, 2452 u.probe_resp.variable); 2453 struct cfg80211_non_tx_bss non_tx_data; 2454 2455 res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt, 2456 len, gfp); 2457 if (!res || !wiphy->support_mbssid || 2458 !cfg80211_find_elem(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) 2459 return res; 2460 if (wiphy->support_only_he_mbssid && 2461 !cfg80211_find_ext_elem(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) 2462 return res; 2463 2464 non_tx_data.tx_bss = res; 2465 /* process each non-transmitting bss */ 2466 cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len, 2467 &non_tx_data, gfp); 2468 2469 spin_lock_bh(&wiphy_to_rdev(wiphy)->bss_lock); 2470 2471 /* check if the res has other nontransmitting bss which is not 2472 * in MBSSID IE 2473 */ 2474 ies1 = rcu_access_pointer(res->ies); 2475 2476 /* go through nontrans_list, if the timestamp of the BSS is 2477 * earlier than the timestamp of the transmitting BSS then 2478 * update it 2479 */ 2480 list_for_each_entry(tmp_bss, &res->nontrans_list, 2481 nontrans_list) { 2482 ies2 = rcu_access_pointer(tmp_bss->ies); 2483 if (ies2->tsf < ies1->tsf) 2484 cfg80211_update_notlisted_nontrans(wiphy, tmp_bss, 2485 mgmt, len); 2486 } 2487 spin_unlock_bh(&wiphy_to_rdev(wiphy)->bss_lock); 2488 2489 return res; 2490 } 2491 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data); 2492 2493 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 2494 { 2495 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2496 struct cfg80211_internal_bss *bss; 2497 2498 if (!pub) 2499 return; 2500 2501 bss = container_of(pub, struct cfg80211_internal_bss, pub); 2502 2503 spin_lock_bh(&rdev->bss_lock); 2504 bss_ref_get(rdev, bss); 2505 spin_unlock_bh(&rdev->bss_lock); 2506 } 2507 EXPORT_SYMBOL(cfg80211_ref_bss); 2508 2509 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 2510 { 2511 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2512 struct cfg80211_internal_bss *bss; 2513 2514 if (!pub) 2515 return; 2516 2517 bss = container_of(pub, struct cfg80211_internal_bss, pub); 2518 2519 spin_lock_bh(&rdev->bss_lock); 2520 bss_ref_put(rdev, bss); 2521 spin_unlock_bh(&rdev->bss_lock); 2522 } 2523 EXPORT_SYMBOL(cfg80211_put_bss); 2524 2525 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 2526 { 2527 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2528 struct cfg80211_internal_bss *bss, *tmp1; 2529 struct cfg80211_bss *nontrans_bss, *tmp; 2530 2531 if (WARN_ON(!pub)) 2532 return; 2533 2534 bss = container_of(pub, struct cfg80211_internal_bss, pub); 2535 2536 spin_lock_bh(&rdev->bss_lock); 2537 if (list_empty(&bss->list)) 2538 goto out; 2539 2540 list_for_each_entry_safe(nontrans_bss, tmp, 2541 &pub->nontrans_list, 2542 nontrans_list) { 2543 tmp1 = container_of(nontrans_bss, 2544 struct cfg80211_internal_bss, pub); 2545 if (__cfg80211_unlink_bss(rdev, tmp1)) 2546 rdev->bss_generation++; 2547 } 2548 2549 if (__cfg80211_unlink_bss(rdev, bss)) 2550 rdev->bss_generation++; 2551 out: 2552 spin_unlock_bh(&rdev->bss_lock); 2553 } 2554 EXPORT_SYMBOL(cfg80211_unlink_bss); 2555 2556 void cfg80211_bss_iter(struct wiphy *wiphy, 2557 struct cfg80211_chan_def *chandef, 2558 void (*iter)(struct wiphy *wiphy, 2559 struct cfg80211_bss *bss, 2560 void *data), 2561 void *iter_data) 2562 { 2563 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2564 struct cfg80211_internal_bss *bss; 2565 2566 spin_lock_bh(&rdev->bss_lock); 2567 2568 list_for_each_entry(bss, &rdev->bss_list, list) { 2569 if (!chandef || cfg80211_is_sub_chan(chandef, bss->pub.channel)) 2570 iter(wiphy, &bss->pub, iter_data); 2571 } 2572 2573 spin_unlock_bh(&rdev->bss_lock); 2574 } 2575 EXPORT_SYMBOL(cfg80211_bss_iter); 2576 2577 void cfg80211_update_assoc_bss_entry(struct wireless_dev *wdev, 2578 struct ieee80211_channel *chan) 2579 { 2580 struct wiphy *wiphy = wdev->wiphy; 2581 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 2582 struct cfg80211_internal_bss *cbss = wdev->current_bss; 2583 struct cfg80211_internal_bss *new = NULL; 2584 struct cfg80211_internal_bss *bss; 2585 struct cfg80211_bss *nontrans_bss; 2586 struct cfg80211_bss *tmp; 2587 2588 spin_lock_bh(&rdev->bss_lock); 2589 2590 /* 2591 * Some APs use CSA also for bandwidth changes, i.e., without actually 2592 * changing the control channel, so no need to update in such a case. 2593 */ 2594 if (cbss->pub.channel == chan) 2595 goto done; 2596 2597 /* use transmitting bss */ 2598 if (cbss->pub.transmitted_bss) 2599 cbss = container_of(cbss->pub.transmitted_bss, 2600 struct cfg80211_internal_bss, 2601 pub); 2602 2603 cbss->pub.channel = chan; 2604 2605 list_for_each_entry(bss, &rdev->bss_list, list) { 2606 if (!cfg80211_bss_type_match(bss->pub.capability, 2607 bss->pub.channel->band, 2608 wdev->conn_bss_type)) 2609 continue; 2610 2611 if (bss == cbss) 2612 continue; 2613 2614 if (!cmp_bss(&bss->pub, &cbss->pub, BSS_CMP_REGULAR)) { 2615 new = bss; 2616 break; 2617 } 2618 } 2619 2620 if (new) { 2621 /* to save time, update IEs for transmitting bss only */ 2622 if (cfg80211_update_known_bss(rdev, cbss, new, false)) { 2623 new->pub.proberesp_ies = NULL; 2624 new->pub.beacon_ies = NULL; 2625 } 2626 2627 list_for_each_entry_safe(nontrans_bss, tmp, 2628 &new->pub.nontrans_list, 2629 nontrans_list) { 2630 bss = container_of(nontrans_bss, 2631 struct cfg80211_internal_bss, pub); 2632 if (__cfg80211_unlink_bss(rdev, bss)) 2633 rdev->bss_generation++; 2634 } 2635 2636 WARN_ON(atomic_read(&new->hold)); 2637 if (!WARN_ON(!__cfg80211_unlink_bss(rdev, new))) 2638 rdev->bss_generation++; 2639 } 2640 2641 rb_erase(&cbss->rbn, &rdev->bss_tree); 2642 rb_insert_bss(rdev, cbss); 2643 rdev->bss_generation++; 2644 2645 list_for_each_entry_safe(nontrans_bss, tmp, 2646 &cbss->pub.nontrans_list, 2647 nontrans_list) { 2648 bss = container_of(nontrans_bss, 2649 struct cfg80211_internal_bss, pub); 2650 bss->pub.channel = chan; 2651 rb_erase(&bss->rbn, &rdev->bss_tree); 2652 rb_insert_bss(rdev, bss); 2653 rdev->bss_generation++; 2654 } 2655 2656 done: 2657 spin_unlock_bh(&rdev->bss_lock); 2658 } 2659 2660 #ifdef CONFIG_CFG80211_WEXT 2661 static struct cfg80211_registered_device * 2662 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) 2663 { 2664 struct cfg80211_registered_device *rdev; 2665 struct net_device *dev; 2666 2667 ASSERT_RTNL(); 2668 2669 dev = dev_get_by_index(net, ifindex); 2670 if (!dev) 2671 return ERR_PTR(-ENODEV); 2672 if (dev->ieee80211_ptr) 2673 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy); 2674 else 2675 rdev = ERR_PTR(-ENODEV); 2676 dev_put(dev); 2677 return rdev; 2678 } 2679 2680 int cfg80211_wext_siwscan(struct net_device *dev, 2681 struct iw_request_info *info, 2682 union iwreq_data *wrqu, char *extra) 2683 { 2684 struct cfg80211_registered_device *rdev; 2685 struct wiphy *wiphy; 2686 struct iw_scan_req *wreq = NULL; 2687 struct cfg80211_scan_request *creq = NULL; 2688 int i, err, n_channels = 0; 2689 enum nl80211_band band; 2690 2691 if (!netif_running(dev)) 2692 return -ENETDOWN; 2693 2694 if (wrqu->data.length == sizeof(struct iw_scan_req)) 2695 wreq = (struct iw_scan_req *)extra; 2696 2697 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 2698 2699 if (IS_ERR(rdev)) 2700 return PTR_ERR(rdev); 2701 2702 if (rdev->scan_req || rdev->scan_msg) { 2703 err = -EBUSY; 2704 goto out; 2705 } 2706 2707 wiphy = &rdev->wiphy; 2708 2709 /* Determine number of channels, needed to allocate creq */ 2710 if (wreq && wreq->num_channels) 2711 n_channels = wreq->num_channels; 2712 else 2713 n_channels = ieee80211_get_num_supported_channels(wiphy); 2714 2715 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + 2716 n_channels * sizeof(void *), 2717 GFP_ATOMIC); 2718 if (!creq) { 2719 err = -ENOMEM; 2720 goto out; 2721 } 2722 2723 creq->wiphy = wiphy; 2724 creq->wdev = dev->ieee80211_ptr; 2725 /* SSIDs come after channels */ 2726 creq->ssids = (void *)&creq->channels[n_channels]; 2727 creq->n_channels = n_channels; 2728 creq->n_ssids = 1; 2729 creq->scan_start = jiffies; 2730 2731 /* translate "Scan on frequencies" request */ 2732 i = 0; 2733 for (band = 0; band < NUM_NL80211_BANDS; band++) { 2734 int j; 2735 2736 if (!wiphy->bands[band]) 2737 continue; 2738 2739 for (j = 0; j < wiphy->bands[band]->n_channels; j++) { 2740 /* ignore disabled channels */ 2741 if (wiphy->bands[band]->channels[j].flags & 2742 IEEE80211_CHAN_DISABLED) 2743 continue; 2744 2745 /* If we have a wireless request structure and the 2746 * wireless request specifies frequencies, then search 2747 * for the matching hardware channel. 2748 */ 2749 if (wreq && wreq->num_channels) { 2750 int k; 2751 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq; 2752 for (k = 0; k < wreq->num_channels; k++) { 2753 struct iw_freq *freq = 2754 &wreq->channel_list[k]; 2755 int wext_freq = 2756 cfg80211_wext_freq(freq); 2757 2758 if (wext_freq == wiphy_freq) 2759 goto wext_freq_found; 2760 } 2761 goto wext_freq_not_found; 2762 } 2763 2764 wext_freq_found: 2765 creq->channels[i] = &wiphy->bands[band]->channels[j]; 2766 i++; 2767 wext_freq_not_found: ; 2768 } 2769 } 2770 /* No channels found? */ 2771 if (!i) { 2772 err = -EINVAL; 2773 goto out; 2774 } 2775 2776 /* Set real number of channels specified in creq->channels[] */ 2777 creq->n_channels = i; 2778 2779 /* translate "Scan for SSID" request */ 2780 if (wreq) { 2781 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) { 2782 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) { 2783 err = -EINVAL; 2784 goto out; 2785 } 2786 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); 2787 creq->ssids[0].ssid_len = wreq->essid_len; 2788 } 2789 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) 2790 creq->n_ssids = 0; 2791 } 2792 2793 for (i = 0; i < NUM_NL80211_BANDS; i++) 2794 if (wiphy->bands[i]) 2795 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; 2796 2797 eth_broadcast_addr(creq->bssid); 2798 2799 wiphy_lock(&rdev->wiphy); 2800 2801 rdev->scan_req = creq; 2802 err = rdev_scan(rdev, creq); 2803 if (err) { 2804 rdev->scan_req = NULL; 2805 /* creq will be freed below */ 2806 } else { 2807 nl80211_send_scan_start(rdev, dev->ieee80211_ptr); 2808 /* creq now owned by driver */ 2809 creq = NULL; 2810 dev_hold(dev); 2811 } 2812 wiphy_unlock(&rdev->wiphy); 2813 out: 2814 kfree(creq); 2815 return err; 2816 } 2817 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan); 2818 2819 static char *ieee80211_scan_add_ies(struct iw_request_info *info, 2820 const struct cfg80211_bss_ies *ies, 2821 char *current_ev, char *end_buf) 2822 { 2823 const u8 *pos, *end, *next; 2824 struct iw_event iwe; 2825 2826 if (!ies) 2827 return current_ev; 2828 2829 /* 2830 * If needed, fragment the IEs buffer (at IE boundaries) into short 2831 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. 2832 */ 2833 pos = ies->data; 2834 end = pos + ies->len; 2835 2836 while (end - pos > IW_GENERIC_IE_MAX) { 2837 next = pos + 2 + pos[1]; 2838 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) 2839 next = next + 2 + next[1]; 2840 2841 memset(&iwe, 0, sizeof(iwe)); 2842 iwe.cmd = IWEVGENIE; 2843 iwe.u.data.length = next - pos; 2844 current_ev = iwe_stream_add_point_check(info, current_ev, 2845 end_buf, &iwe, 2846 (void *)pos); 2847 if (IS_ERR(current_ev)) 2848 return current_ev; 2849 pos = next; 2850 } 2851 2852 if (end > pos) { 2853 memset(&iwe, 0, sizeof(iwe)); 2854 iwe.cmd = IWEVGENIE; 2855 iwe.u.data.length = end - pos; 2856 current_ev = iwe_stream_add_point_check(info, current_ev, 2857 end_buf, &iwe, 2858 (void *)pos); 2859 if (IS_ERR(current_ev)) 2860 return current_ev; 2861 } 2862 2863 return current_ev; 2864 } 2865 2866 static char * 2867 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, 2868 struct cfg80211_internal_bss *bss, char *current_ev, 2869 char *end_buf) 2870 { 2871 const struct cfg80211_bss_ies *ies; 2872 struct iw_event iwe; 2873 const u8 *ie; 2874 u8 buf[50]; 2875 u8 *cfg, *p, *tmp; 2876 int rem, i, sig; 2877 bool ismesh = false; 2878 2879 memset(&iwe, 0, sizeof(iwe)); 2880 iwe.cmd = SIOCGIWAP; 2881 iwe.u.ap_addr.sa_family = ARPHRD_ETHER; 2882 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN); 2883 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2884 IW_EV_ADDR_LEN); 2885 if (IS_ERR(current_ev)) 2886 return current_ev; 2887 2888 memset(&iwe, 0, sizeof(iwe)); 2889 iwe.cmd = SIOCGIWFREQ; 2890 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq); 2891 iwe.u.freq.e = 0; 2892 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2893 IW_EV_FREQ_LEN); 2894 if (IS_ERR(current_ev)) 2895 return current_ev; 2896 2897 memset(&iwe, 0, sizeof(iwe)); 2898 iwe.cmd = SIOCGIWFREQ; 2899 iwe.u.freq.m = bss->pub.channel->center_freq; 2900 iwe.u.freq.e = 6; 2901 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 2902 IW_EV_FREQ_LEN); 2903 if (IS_ERR(current_ev)) 2904 return current_ev; 2905 2906 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) { 2907 memset(&iwe, 0, sizeof(iwe)); 2908 iwe.cmd = IWEVQUAL; 2909 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED | 2910 IW_QUAL_NOISE_INVALID | 2911 IW_QUAL_QUAL_UPDATED; 2912 switch (wiphy->signal_type) { 2913 case CFG80211_SIGNAL_TYPE_MBM: 2914 sig = bss->pub.signal / 100; 2915 iwe.u.qual.level = sig; 2916 iwe.u.qual.updated |= IW_QUAL_DBM; 2917 if (sig < -110) /* rather bad */ 2918 sig = -110; 2919 else if (sig > -40) /* perfect */ 2920 sig = -40; 2921 /* will give a range of 0 .. 70 */ 2922 iwe.u.qual.qual = sig + 110; 2923 break; 2924 case CFG80211_SIGNAL_TYPE_UNSPEC: 2925 iwe.u.qual.level = bss->pub.signal; 2926 /* will give range 0 .. 100 */ 2927 iwe.u.qual.qual = bss->pub.signal; 2928 break; 2929 default: 2930 /* not reached */ 2931 break; 2932 } 2933 current_ev = iwe_stream_add_event_check(info, current_ev, 2934 end_buf, &iwe, 2935 IW_EV_QUAL_LEN); 2936 if (IS_ERR(current_ev)) 2937 return current_ev; 2938 } 2939 2940 memset(&iwe, 0, sizeof(iwe)); 2941 iwe.cmd = SIOCGIWENCODE; 2942 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY) 2943 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; 2944 else 2945 iwe.u.data.flags = IW_ENCODE_DISABLED; 2946 iwe.u.data.length = 0; 2947 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 2948 &iwe, ""); 2949 if (IS_ERR(current_ev)) 2950 return current_ev; 2951 2952 rcu_read_lock(); 2953 ies = rcu_dereference(bss->pub.ies); 2954 rem = ies->len; 2955 ie = ies->data; 2956 2957 while (rem >= 2) { 2958 /* invalid data */ 2959 if (ie[1] > rem - 2) 2960 break; 2961 2962 switch (ie[0]) { 2963 case WLAN_EID_SSID: 2964 memset(&iwe, 0, sizeof(iwe)); 2965 iwe.cmd = SIOCGIWESSID; 2966 iwe.u.data.length = ie[1]; 2967 iwe.u.data.flags = 1; 2968 current_ev = iwe_stream_add_point_check(info, 2969 current_ev, 2970 end_buf, &iwe, 2971 (u8 *)ie + 2); 2972 if (IS_ERR(current_ev)) 2973 goto unlock; 2974 break; 2975 case WLAN_EID_MESH_ID: 2976 memset(&iwe, 0, sizeof(iwe)); 2977 iwe.cmd = SIOCGIWESSID; 2978 iwe.u.data.length = ie[1]; 2979 iwe.u.data.flags = 1; 2980 current_ev = iwe_stream_add_point_check(info, 2981 current_ev, 2982 end_buf, &iwe, 2983 (u8 *)ie + 2); 2984 if (IS_ERR(current_ev)) 2985 goto unlock; 2986 break; 2987 case WLAN_EID_MESH_CONFIG: 2988 ismesh = true; 2989 if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) 2990 break; 2991 cfg = (u8 *)ie + 2; 2992 memset(&iwe, 0, sizeof(iwe)); 2993 iwe.cmd = IWEVCUSTOM; 2994 sprintf(buf, "Mesh Network Path Selection Protocol ID: " 2995 "0x%02X", cfg[0]); 2996 iwe.u.data.length = strlen(buf); 2997 current_ev = iwe_stream_add_point_check(info, 2998 current_ev, 2999 end_buf, 3000 &iwe, buf); 3001 if (IS_ERR(current_ev)) 3002 goto unlock; 3003 sprintf(buf, "Path Selection Metric ID: 0x%02X", 3004 cfg[1]); 3005 iwe.u.data.length = strlen(buf); 3006 current_ev = iwe_stream_add_point_check(info, 3007 current_ev, 3008 end_buf, 3009 &iwe, buf); 3010 if (IS_ERR(current_ev)) 3011 goto unlock; 3012 sprintf(buf, "Congestion Control Mode ID: 0x%02X", 3013 cfg[2]); 3014 iwe.u.data.length = strlen(buf); 3015 current_ev = iwe_stream_add_point_check(info, 3016 current_ev, 3017 end_buf, 3018 &iwe, buf); 3019 if (IS_ERR(current_ev)) 3020 goto unlock; 3021 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]); 3022 iwe.u.data.length = strlen(buf); 3023 current_ev = iwe_stream_add_point_check(info, 3024 current_ev, 3025 end_buf, 3026 &iwe, buf); 3027 if (IS_ERR(current_ev)) 3028 goto unlock; 3029 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]); 3030 iwe.u.data.length = strlen(buf); 3031 current_ev = iwe_stream_add_point_check(info, 3032 current_ev, 3033 end_buf, 3034 &iwe, buf); 3035 if (IS_ERR(current_ev)) 3036 goto unlock; 3037 sprintf(buf, "Formation Info: 0x%02X", cfg[5]); 3038 iwe.u.data.length = strlen(buf); 3039 current_ev = iwe_stream_add_point_check(info, 3040 current_ev, 3041 end_buf, 3042 &iwe, buf); 3043 if (IS_ERR(current_ev)) 3044 goto unlock; 3045 sprintf(buf, "Capabilities: 0x%02X", cfg[6]); 3046 iwe.u.data.length = strlen(buf); 3047 current_ev = iwe_stream_add_point_check(info, 3048 current_ev, 3049 end_buf, 3050 &iwe, buf); 3051 if (IS_ERR(current_ev)) 3052 goto unlock; 3053 break; 3054 case WLAN_EID_SUPP_RATES: 3055 case WLAN_EID_EXT_SUPP_RATES: 3056 /* display all supported rates in readable format */ 3057 p = current_ev + iwe_stream_lcp_len(info); 3058 3059 memset(&iwe, 0, sizeof(iwe)); 3060 iwe.cmd = SIOCGIWRATE; 3061 /* Those two flags are ignored... */ 3062 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; 3063 3064 for (i = 0; i < ie[1]; i++) { 3065 iwe.u.bitrate.value = 3066 ((ie[i + 2] & 0x7f) * 500000); 3067 tmp = p; 3068 p = iwe_stream_add_value(info, current_ev, p, 3069 end_buf, &iwe, 3070 IW_EV_PARAM_LEN); 3071 if (p == tmp) { 3072 current_ev = ERR_PTR(-E2BIG); 3073 goto unlock; 3074 } 3075 } 3076 current_ev = p; 3077 break; 3078 } 3079 rem -= ie[1] + 2; 3080 ie += ie[1] + 2; 3081 } 3082 3083 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) || 3084 ismesh) { 3085 memset(&iwe, 0, sizeof(iwe)); 3086 iwe.cmd = SIOCGIWMODE; 3087 if (ismesh) 3088 iwe.u.mode = IW_MODE_MESH; 3089 else if (bss->pub.capability & WLAN_CAPABILITY_ESS) 3090 iwe.u.mode = IW_MODE_MASTER; 3091 else 3092 iwe.u.mode = IW_MODE_ADHOC; 3093 current_ev = iwe_stream_add_event_check(info, current_ev, 3094 end_buf, &iwe, 3095 IW_EV_UINT_LEN); 3096 if (IS_ERR(current_ev)) 3097 goto unlock; 3098 } 3099 3100 memset(&iwe, 0, sizeof(iwe)); 3101 iwe.cmd = IWEVCUSTOM; 3102 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf)); 3103 iwe.u.data.length = strlen(buf); 3104 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 3105 &iwe, buf); 3106 if (IS_ERR(current_ev)) 3107 goto unlock; 3108 memset(&iwe, 0, sizeof(iwe)); 3109 iwe.cmd = IWEVCUSTOM; 3110 sprintf(buf, " Last beacon: %ums ago", 3111 elapsed_jiffies_msecs(bss->ts)); 3112 iwe.u.data.length = strlen(buf); 3113 current_ev = iwe_stream_add_point_check(info, current_ev, 3114 end_buf, &iwe, buf); 3115 if (IS_ERR(current_ev)) 3116 goto unlock; 3117 3118 current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf); 3119 3120 unlock: 3121 rcu_read_unlock(); 3122 return current_ev; 3123 } 3124 3125 3126 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev, 3127 struct iw_request_info *info, 3128 char *buf, size_t len) 3129 { 3130 char *current_ev = buf; 3131 char *end_buf = buf + len; 3132 struct cfg80211_internal_bss *bss; 3133 int err = 0; 3134 3135 spin_lock_bh(&rdev->bss_lock); 3136 cfg80211_bss_expire(rdev); 3137 3138 list_for_each_entry(bss, &rdev->bss_list, list) { 3139 if (buf + len - current_ev <= IW_EV_ADDR_LEN) { 3140 err = -E2BIG; 3141 break; 3142 } 3143 current_ev = ieee80211_bss(&rdev->wiphy, info, bss, 3144 current_ev, end_buf); 3145 if (IS_ERR(current_ev)) { 3146 err = PTR_ERR(current_ev); 3147 break; 3148 } 3149 } 3150 spin_unlock_bh(&rdev->bss_lock); 3151 3152 if (err) 3153 return err; 3154 return current_ev - buf; 3155 } 3156 3157 3158 int cfg80211_wext_giwscan(struct net_device *dev, 3159 struct iw_request_info *info, 3160 struct iw_point *data, char *extra) 3161 { 3162 struct cfg80211_registered_device *rdev; 3163 int res; 3164 3165 if (!netif_running(dev)) 3166 return -ENETDOWN; 3167 3168 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 3169 3170 if (IS_ERR(rdev)) 3171 return PTR_ERR(rdev); 3172 3173 if (rdev->scan_req || rdev->scan_msg) 3174 return -EAGAIN; 3175 3176 res = ieee80211_scan_results(rdev, info, extra, data->length); 3177 data->length = 0; 3178 if (res >= 0) { 3179 data->length = res; 3180 res = 0; 3181 } 3182 3183 return res; 3184 } 3185 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan); 3186 #endif 3187