1 /* 2 * cfg80211 scan result handling 3 * 4 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net> 5 * Copyright 2013-2014 Intel Mobile Communications GmbH 6 * Copyright 2016 Intel Deutschland GmbH 7 */ 8 #include <linux/kernel.h> 9 #include <linux/slab.h> 10 #include <linux/module.h> 11 #include <linux/netdevice.h> 12 #include <linux/wireless.h> 13 #include <linux/nl80211.h> 14 #include <linux/etherdevice.h> 15 #include <net/arp.h> 16 #include <net/cfg80211.h> 17 #include <net/cfg80211-wext.h> 18 #include <net/iw_handler.h> 19 #include "core.h" 20 #include "nl80211.h" 21 #include "wext-compat.h" 22 #include "rdev-ops.h" 23 24 /** 25 * DOC: BSS tree/list structure 26 * 27 * At the top level, the BSS list is kept in both a list in each 28 * registered device (@bss_list) as well as an RB-tree for faster 29 * lookup. In the RB-tree, entries can be looked up using their 30 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID 31 * for other BSSes. 32 * 33 * Due to the possibility of hidden SSIDs, there's a second level 34 * structure, the "hidden_list" and "hidden_beacon_bss" pointer. 35 * The hidden_list connects all BSSes belonging to a single AP 36 * that has a hidden SSID, and connects beacon and probe response 37 * entries. For a probe response entry for a hidden SSID, the 38 * hidden_beacon_bss pointer points to the BSS struct holding the 39 * beacon's information. 40 * 41 * Reference counting is done for all these references except for 42 * the hidden_list, so that a beacon BSS struct that is otherwise 43 * not referenced has one reference for being on the bss_list and 44 * one for each probe response entry that points to it using the 45 * hidden_beacon_bss pointer. When a BSS struct that has such a 46 * pointer is get/put, the refcount update is also propagated to 47 * the referenced struct, this ensure that it cannot get removed 48 * while somebody is using the probe response version. 49 * 50 * Note that the hidden_beacon_bss pointer never changes, due to 51 * the reference counting. Therefore, no locking is needed for 52 * it. 53 * 54 * Also note that the hidden_beacon_bss pointer is only relevant 55 * if the driver uses something other than the IEs, e.g. private 56 * data stored stored in the BSS struct, since the beacon IEs are 57 * also linked into the probe response struct. 58 */ 59 60 /* 61 * Limit the number of BSS entries stored in mac80211. Each one is 62 * a bit over 4k at most, so this limits to roughly 4-5M of memory. 63 * If somebody wants to really attack this though, they'd likely 64 * use small beacons, and only one type of frame, limiting each of 65 * the entries to a much smaller size (in order to generate more 66 * entries in total, so overhead is bigger.) 67 */ 68 static int bss_entries_limit = 1000; 69 module_param(bss_entries_limit, int, 0644); 70 MODULE_PARM_DESC(bss_entries_limit, 71 "limit to number of scan BSS entries (per wiphy, default 1000)"); 72 73 #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) 74 75 static void bss_free(struct cfg80211_internal_bss *bss) 76 { 77 struct cfg80211_bss_ies *ies; 78 79 if (WARN_ON(atomic_read(&bss->hold))) 80 return; 81 82 ies = (void *)rcu_access_pointer(bss->pub.beacon_ies); 83 if (ies && !bss->pub.hidden_beacon_bss) 84 kfree_rcu(ies, rcu_head); 85 ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies); 86 if (ies) 87 kfree_rcu(ies, rcu_head); 88 89 /* 90 * This happens when the module is removed, it doesn't 91 * really matter any more save for completeness 92 */ 93 if (!list_empty(&bss->hidden_list)) 94 list_del(&bss->hidden_list); 95 96 kfree(bss); 97 } 98 99 static inline void bss_ref_get(struct cfg80211_registered_device *rdev, 100 struct cfg80211_internal_bss *bss) 101 { 102 lockdep_assert_held(&rdev->bss_lock); 103 104 bss->refcount++; 105 if (bss->pub.hidden_beacon_bss) { 106 bss = container_of(bss->pub.hidden_beacon_bss, 107 struct cfg80211_internal_bss, 108 pub); 109 bss->refcount++; 110 } 111 } 112 113 static inline void bss_ref_put(struct cfg80211_registered_device *rdev, 114 struct cfg80211_internal_bss *bss) 115 { 116 lockdep_assert_held(&rdev->bss_lock); 117 118 if (bss->pub.hidden_beacon_bss) { 119 struct cfg80211_internal_bss *hbss; 120 hbss = container_of(bss->pub.hidden_beacon_bss, 121 struct cfg80211_internal_bss, 122 pub); 123 hbss->refcount--; 124 if (hbss->refcount == 0) 125 bss_free(hbss); 126 } 127 bss->refcount--; 128 if (bss->refcount == 0) 129 bss_free(bss); 130 } 131 132 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, 133 struct cfg80211_internal_bss *bss) 134 { 135 lockdep_assert_held(&rdev->bss_lock); 136 137 if (!list_empty(&bss->hidden_list)) { 138 /* 139 * don't remove the beacon entry if it has 140 * probe responses associated with it 141 */ 142 if (!bss->pub.hidden_beacon_bss) 143 return false; 144 /* 145 * if it's a probe response entry break its 146 * link to the other entries in the group 147 */ 148 list_del_init(&bss->hidden_list); 149 } 150 151 list_del_init(&bss->list); 152 rb_erase(&bss->rbn, &rdev->bss_tree); 153 rdev->bss_entries--; 154 WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list), 155 "rdev bss entries[%d]/list[empty:%d] corruption\n", 156 rdev->bss_entries, list_empty(&rdev->bss_list)); 157 bss_ref_put(rdev, bss); 158 return true; 159 } 160 161 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, 162 unsigned long expire_time) 163 { 164 struct cfg80211_internal_bss *bss, *tmp; 165 bool expired = false; 166 167 lockdep_assert_held(&rdev->bss_lock); 168 169 list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) { 170 if (atomic_read(&bss->hold)) 171 continue; 172 if (!time_after(expire_time, bss->ts)) 173 continue; 174 175 if (__cfg80211_unlink_bss(rdev, bss)) 176 expired = true; 177 } 178 179 if (expired) 180 rdev->bss_generation++; 181 } 182 183 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) 184 { 185 struct cfg80211_internal_bss *bss, *oldest = NULL; 186 bool ret; 187 188 lockdep_assert_held(&rdev->bss_lock); 189 190 list_for_each_entry(bss, &rdev->bss_list, list) { 191 if (atomic_read(&bss->hold)) 192 continue; 193 194 if (!list_empty(&bss->hidden_list) && 195 !bss->pub.hidden_beacon_bss) 196 continue; 197 198 if (oldest && time_before(oldest->ts, bss->ts)) 199 continue; 200 oldest = bss; 201 } 202 203 if (WARN_ON(!oldest)) 204 return false; 205 206 /* 207 * The callers make sure to increase rdev->bss_generation if anything 208 * gets removed (and a new entry added), so there's no need to also do 209 * it here. 210 */ 211 212 ret = __cfg80211_unlink_bss(rdev, oldest); 213 WARN_ON(!ret); 214 return ret; 215 } 216 217 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, 218 bool send_message) 219 { 220 struct cfg80211_scan_request *request; 221 struct wireless_dev *wdev; 222 struct sk_buff *msg; 223 #ifdef CONFIG_CFG80211_WEXT 224 union iwreq_data wrqu; 225 #endif 226 227 ASSERT_RTNL(); 228 229 if (rdev->scan_msg) { 230 nl80211_send_scan_msg(rdev, rdev->scan_msg); 231 rdev->scan_msg = NULL; 232 return; 233 } 234 235 request = rdev->scan_req; 236 if (!request) 237 return; 238 239 wdev = request->wdev; 240 241 /* 242 * This must be before sending the other events! 243 * Otherwise, wpa_supplicant gets completely confused with 244 * wext events. 245 */ 246 if (wdev->netdev) 247 cfg80211_sme_scan_done(wdev->netdev); 248 249 if (!request->info.aborted && 250 request->flags & NL80211_SCAN_FLAG_FLUSH) { 251 /* flush entries from previous scans */ 252 spin_lock_bh(&rdev->bss_lock); 253 __cfg80211_bss_expire(rdev, request->scan_start); 254 spin_unlock_bh(&rdev->bss_lock); 255 } 256 257 msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted); 258 259 #ifdef CONFIG_CFG80211_WEXT 260 if (wdev->netdev && !request->info.aborted) { 261 memset(&wrqu, 0, sizeof(wrqu)); 262 263 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL); 264 } 265 #endif 266 267 if (wdev->netdev) 268 dev_put(wdev->netdev); 269 270 rdev->scan_req = NULL; 271 kfree(request); 272 273 if (!send_message) 274 rdev->scan_msg = msg; 275 else 276 nl80211_send_scan_msg(rdev, msg); 277 } 278 279 void __cfg80211_scan_done(struct work_struct *wk) 280 { 281 struct cfg80211_registered_device *rdev; 282 283 rdev = container_of(wk, struct cfg80211_registered_device, 284 scan_done_wk); 285 286 rtnl_lock(); 287 ___cfg80211_scan_done(rdev, true); 288 rtnl_unlock(); 289 } 290 291 void cfg80211_scan_done(struct cfg80211_scan_request *request, 292 struct cfg80211_scan_info *info) 293 { 294 trace_cfg80211_scan_done(request, info); 295 WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req); 296 297 request->info = *info; 298 request->notified = true; 299 queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk); 300 } 301 EXPORT_SYMBOL(cfg80211_scan_done); 302 303 void __cfg80211_sched_scan_results(struct work_struct *wk) 304 { 305 struct cfg80211_registered_device *rdev; 306 struct cfg80211_sched_scan_request *request; 307 308 rdev = container_of(wk, struct cfg80211_registered_device, 309 sched_scan_results_wk); 310 311 rtnl_lock(); 312 313 request = rtnl_dereference(rdev->sched_scan_req); 314 315 /* we don't have sched_scan_req anymore if the scan is stopping */ 316 if (request) { 317 if (request->flags & NL80211_SCAN_FLAG_FLUSH) { 318 /* flush entries from previous scans */ 319 spin_lock_bh(&rdev->bss_lock); 320 __cfg80211_bss_expire(rdev, request->scan_start); 321 spin_unlock_bh(&rdev->bss_lock); 322 request->scan_start = jiffies; 323 } 324 nl80211_send_sched_scan(rdev, request->dev, 325 NL80211_CMD_SCHED_SCAN_RESULTS); 326 } 327 328 rtnl_unlock(); 329 } 330 331 void cfg80211_sched_scan_results(struct wiphy *wiphy) 332 { 333 trace_cfg80211_sched_scan_results(wiphy); 334 /* ignore if we're not scanning */ 335 336 if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req)) 337 queue_work(cfg80211_wq, 338 &wiphy_to_rdev(wiphy)->sched_scan_results_wk); 339 } 340 EXPORT_SYMBOL(cfg80211_sched_scan_results); 341 342 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy) 343 { 344 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 345 346 ASSERT_RTNL(); 347 348 trace_cfg80211_sched_scan_stopped(wiphy); 349 350 __cfg80211_stop_sched_scan(rdev, true); 351 } 352 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl); 353 354 void cfg80211_sched_scan_stopped(struct wiphy *wiphy) 355 { 356 rtnl_lock(); 357 cfg80211_sched_scan_stopped_rtnl(wiphy); 358 rtnl_unlock(); 359 } 360 EXPORT_SYMBOL(cfg80211_sched_scan_stopped); 361 362 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, 363 bool driver_initiated) 364 { 365 struct cfg80211_sched_scan_request *sched_scan_req; 366 struct net_device *dev; 367 368 ASSERT_RTNL(); 369 370 if (!rdev->sched_scan_req) 371 return -ENOENT; 372 373 sched_scan_req = rtnl_dereference(rdev->sched_scan_req); 374 dev = sched_scan_req->dev; 375 376 if (!driver_initiated) { 377 int err = rdev_sched_scan_stop(rdev, dev); 378 if (err) 379 return err; 380 } 381 382 nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED); 383 384 RCU_INIT_POINTER(rdev->sched_scan_req, NULL); 385 kfree_rcu(sched_scan_req, rcu_head); 386 387 return 0; 388 } 389 390 void cfg80211_bss_age(struct cfg80211_registered_device *rdev, 391 unsigned long age_secs) 392 { 393 struct cfg80211_internal_bss *bss; 394 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); 395 396 spin_lock_bh(&rdev->bss_lock); 397 list_for_each_entry(bss, &rdev->bss_list, list) 398 bss->ts -= age_jiffies; 399 spin_unlock_bh(&rdev->bss_lock); 400 } 401 402 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev) 403 { 404 __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); 405 } 406 407 const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len, 408 const u8 *match, int match_len, 409 int match_offset) 410 { 411 /* match_offset can't be smaller than 2, unless match_len is 412 * zero, in which case match_offset must be zero as well. 413 */ 414 if (WARN_ON((match_len && match_offset < 2) || 415 (!match_len && match_offset))) 416 return NULL; 417 418 while (len >= 2 && len >= ies[1] + 2) { 419 if ((ies[0] == eid) && 420 (ies[1] + 2 >= match_offset + match_len) && 421 !memcmp(ies + match_offset, match, match_len)) 422 return ies; 423 424 len -= ies[1] + 2; 425 ies += ies[1] + 2; 426 } 427 428 return NULL; 429 } 430 EXPORT_SYMBOL(cfg80211_find_ie_match); 431 432 const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type, 433 const u8 *ies, int len) 434 { 435 const u8 *ie; 436 u8 match[] = { oui >> 16, oui >> 8, oui, oui_type }; 437 int match_len = (oui_type < 0) ? 3 : sizeof(match); 438 439 if (WARN_ON(oui_type > 0xff)) 440 return NULL; 441 442 ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len, 443 match, match_len, 2); 444 445 if (ie && (ie[1] < 4)) 446 return NULL; 447 448 return ie; 449 } 450 EXPORT_SYMBOL(cfg80211_find_vendor_ie); 451 452 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, 453 const u8 *ssid, size_t ssid_len) 454 { 455 const struct cfg80211_bss_ies *ies; 456 const u8 *ssidie; 457 458 if (bssid && !ether_addr_equal(a->bssid, bssid)) 459 return false; 460 461 if (!ssid) 462 return true; 463 464 ies = rcu_access_pointer(a->ies); 465 if (!ies) 466 return false; 467 ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 468 if (!ssidie) 469 return false; 470 if (ssidie[1] != ssid_len) 471 return false; 472 return memcmp(ssidie + 2, ssid, ssid_len) == 0; 473 } 474 475 /** 476 * enum bss_compare_mode - BSS compare mode 477 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) 478 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode 479 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode 480 */ 481 enum bss_compare_mode { 482 BSS_CMP_REGULAR, 483 BSS_CMP_HIDE_ZLEN, 484 BSS_CMP_HIDE_NUL, 485 }; 486 487 static int cmp_bss(struct cfg80211_bss *a, 488 struct cfg80211_bss *b, 489 enum bss_compare_mode mode) 490 { 491 const struct cfg80211_bss_ies *a_ies, *b_ies; 492 const u8 *ie1 = NULL; 493 const u8 *ie2 = NULL; 494 int i, r; 495 496 if (a->channel != b->channel) 497 return b->channel->center_freq - a->channel->center_freq; 498 499 a_ies = rcu_access_pointer(a->ies); 500 if (!a_ies) 501 return -1; 502 b_ies = rcu_access_pointer(b->ies); 503 if (!b_ies) 504 return 1; 505 506 if (WLAN_CAPABILITY_IS_STA_BSS(a->capability)) 507 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID, 508 a_ies->data, a_ies->len); 509 if (WLAN_CAPABILITY_IS_STA_BSS(b->capability)) 510 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID, 511 b_ies->data, b_ies->len); 512 if (ie1 && ie2) { 513 int mesh_id_cmp; 514 515 if (ie1[1] == ie2[1]) 516 mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]); 517 else 518 mesh_id_cmp = ie2[1] - ie1[1]; 519 520 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 521 a_ies->data, a_ies->len); 522 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, 523 b_ies->data, b_ies->len); 524 if (ie1 && ie2) { 525 if (mesh_id_cmp) 526 return mesh_id_cmp; 527 if (ie1[1] != ie2[1]) 528 return ie2[1] - ie1[1]; 529 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 530 } 531 } 532 533 r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); 534 if (r) 535 return r; 536 537 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len); 538 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len); 539 540 if (!ie1 && !ie2) 541 return 0; 542 543 /* 544 * Note that with "hide_ssid", the function returns a match if 545 * the already-present BSS ("b") is a hidden SSID beacon for 546 * the new BSS ("a"). 547 */ 548 549 /* sort missing IE before (left of) present IE */ 550 if (!ie1) 551 return -1; 552 if (!ie2) 553 return 1; 554 555 switch (mode) { 556 case BSS_CMP_HIDE_ZLEN: 557 /* 558 * In ZLEN mode we assume the BSS entry we're 559 * looking for has a zero-length SSID. So if 560 * the one we're looking at right now has that, 561 * return 0. Otherwise, return the difference 562 * in length, but since we're looking for the 563 * 0-length it's really equivalent to returning 564 * the length of the one we're looking at. 565 * 566 * No content comparison is needed as we assume 567 * the content length is zero. 568 */ 569 return ie2[1]; 570 case BSS_CMP_REGULAR: 571 default: 572 /* sort by length first, then by contents */ 573 if (ie1[1] != ie2[1]) 574 return ie2[1] - ie1[1]; 575 return memcmp(ie1 + 2, ie2 + 2, ie1[1]); 576 case BSS_CMP_HIDE_NUL: 577 if (ie1[1] != ie2[1]) 578 return ie2[1] - ie1[1]; 579 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */ 580 for (i = 0; i < ie2[1]; i++) 581 if (ie2[i + 2]) 582 return -1; 583 return 0; 584 } 585 } 586 587 static bool cfg80211_bss_type_match(u16 capability, 588 enum nl80211_band band, 589 enum ieee80211_bss_type bss_type) 590 { 591 bool ret = true; 592 u16 mask, val; 593 594 if (bss_type == IEEE80211_BSS_TYPE_ANY) 595 return ret; 596 597 if (band == NL80211_BAND_60GHZ) { 598 mask = WLAN_CAPABILITY_DMG_TYPE_MASK; 599 switch (bss_type) { 600 case IEEE80211_BSS_TYPE_ESS: 601 val = WLAN_CAPABILITY_DMG_TYPE_AP; 602 break; 603 case IEEE80211_BSS_TYPE_PBSS: 604 val = WLAN_CAPABILITY_DMG_TYPE_PBSS; 605 break; 606 case IEEE80211_BSS_TYPE_IBSS: 607 val = WLAN_CAPABILITY_DMG_TYPE_IBSS; 608 break; 609 default: 610 return false; 611 } 612 } else { 613 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS; 614 switch (bss_type) { 615 case IEEE80211_BSS_TYPE_ESS: 616 val = WLAN_CAPABILITY_ESS; 617 break; 618 case IEEE80211_BSS_TYPE_IBSS: 619 val = WLAN_CAPABILITY_IBSS; 620 break; 621 case IEEE80211_BSS_TYPE_MBSS: 622 val = 0; 623 break; 624 default: 625 return false; 626 } 627 } 628 629 ret = ((capability & mask) == val); 630 return ret; 631 } 632 633 /* Returned bss is reference counted and must be cleaned up appropriately. */ 634 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, 635 struct ieee80211_channel *channel, 636 const u8 *bssid, 637 const u8 *ssid, size_t ssid_len, 638 enum ieee80211_bss_type bss_type, 639 enum ieee80211_privacy privacy) 640 { 641 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 642 struct cfg80211_internal_bss *bss, *res = NULL; 643 unsigned long now = jiffies; 644 int bss_privacy; 645 646 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type, 647 privacy); 648 649 spin_lock_bh(&rdev->bss_lock); 650 651 list_for_each_entry(bss, &rdev->bss_list, list) { 652 if (!cfg80211_bss_type_match(bss->pub.capability, 653 bss->pub.channel->band, bss_type)) 654 continue; 655 656 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY); 657 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) || 658 (privacy == IEEE80211_PRIVACY_OFF && bss_privacy)) 659 continue; 660 if (channel && bss->pub.channel != channel) 661 continue; 662 if (!is_valid_ether_addr(bss->pub.bssid)) 663 continue; 664 /* Don't get expired BSS structs */ 665 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && 666 !atomic_read(&bss->hold)) 667 continue; 668 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { 669 res = bss; 670 bss_ref_get(rdev, res); 671 break; 672 } 673 } 674 675 spin_unlock_bh(&rdev->bss_lock); 676 if (!res) 677 return NULL; 678 trace_cfg80211_return_bss(&res->pub); 679 return &res->pub; 680 } 681 EXPORT_SYMBOL(cfg80211_get_bss); 682 683 static void rb_insert_bss(struct cfg80211_registered_device *rdev, 684 struct cfg80211_internal_bss *bss) 685 { 686 struct rb_node **p = &rdev->bss_tree.rb_node; 687 struct rb_node *parent = NULL; 688 struct cfg80211_internal_bss *tbss; 689 int cmp; 690 691 while (*p) { 692 parent = *p; 693 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); 694 695 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR); 696 697 if (WARN_ON(!cmp)) { 698 /* will sort of leak this BSS */ 699 return; 700 } 701 702 if (cmp < 0) 703 p = &(*p)->rb_left; 704 else 705 p = &(*p)->rb_right; 706 } 707 708 rb_link_node(&bss->rbn, parent, p); 709 rb_insert_color(&bss->rbn, &rdev->bss_tree); 710 } 711 712 static struct cfg80211_internal_bss * 713 rb_find_bss(struct cfg80211_registered_device *rdev, 714 struct cfg80211_internal_bss *res, 715 enum bss_compare_mode mode) 716 { 717 struct rb_node *n = rdev->bss_tree.rb_node; 718 struct cfg80211_internal_bss *bss; 719 int r; 720 721 while (n) { 722 bss = rb_entry(n, struct cfg80211_internal_bss, rbn); 723 r = cmp_bss(&res->pub, &bss->pub, mode); 724 725 if (r == 0) 726 return bss; 727 else if (r < 0) 728 n = n->rb_left; 729 else 730 n = n->rb_right; 731 } 732 733 return NULL; 734 } 735 736 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, 737 struct cfg80211_internal_bss *new) 738 { 739 const struct cfg80211_bss_ies *ies; 740 struct cfg80211_internal_bss *bss; 741 const u8 *ie; 742 int i, ssidlen; 743 u8 fold = 0; 744 u32 n_entries = 0; 745 746 ies = rcu_access_pointer(new->pub.beacon_ies); 747 if (WARN_ON(!ies)) 748 return false; 749 750 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 751 if (!ie) { 752 /* nothing to do */ 753 return true; 754 } 755 756 ssidlen = ie[1]; 757 for (i = 0; i < ssidlen; i++) 758 fold |= ie[2 + i]; 759 760 if (fold) { 761 /* not a hidden SSID */ 762 return true; 763 } 764 765 /* This is the bad part ... */ 766 767 list_for_each_entry(bss, &rdev->bss_list, list) { 768 /* 769 * we're iterating all the entries anyway, so take the 770 * opportunity to validate the list length accounting 771 */ 772 n_entries++; 773 774 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) 775 continue; 776 if (bss->pub.channel != new->pub.channel) 777 continue; 778 if (bss->pub.scan_width != new->pub.scan_width) 779 continue; 780 if (rcu_access_pointer(bss->pub.beacon_ies)) 781 continue; 782 ies = rcu_access_pointer(bss->pub.ies); 783 if (!ies) 784 continue; 785 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); 786 if (!ie) 787 continue; 788 if (ssidlen && ie[1] != ssidlen) 789 continue; 790 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss)) 791 continue; 792 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list))) 793 list_del(&bss->hidden_list); 794 /* combine them */ 795 list_add(&bss->hidden_list, &new->hidden_list); 796 bss->pub.hidden_beacon_bss = &new->pub; 797 new->refcount += bss->refcount; 798 rcu_assign_pointer(bss->pub.beacon_ies, 799 new->pub.beacon_ies); 800 } 801 802 WARN_ONCE(n_entries != rdev->bss_entries, 803 "rdev bss entries[%d]/list[len:%d] corruption\n", 804 rdev->bss_entries, n_entries); 805 806 return true; 807 } 808 809 /* Returned bss is reference counted and must be cleaned up appropriately. */ 810 static struct cfg80211_internal_bss * 811 cfg80211_bss_update(struct cfg80211_registered_device *rdev, 812 struct cfg80211_internal_bss *tmp, 813 bool signal_valid) 814 { 815 struct cfg80211_internal_bss *found = NULL; 816 817 if (WARN_ON(!tmp->pub.channel)) 818 return NULL; 819 820 tmp->ts = jiffies; 821 822 spin_lock_bh(&rdev->bss_lock); 823 824 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) { 825 spin_unlock_bh(&rdev->bss_lock); 826 return NULL; 827 } 828 829 found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR); 830 831 if (found) { 832 /* Update IEs */ 833 if (rcu_access_pointer(tmp->pub.proberesp_ies)) { 834 const struct cfg80211_bss_ies *old; 835 836 old = rcu_access_pointer(found->pub.proberesp_ies); 837 838 rcu_assign_pointer(found->pub.proberesp_ies, 839 tmp->pub.proberesp_ies); 840 /* Override possible earlier Beacon frame IEs */ 841 rcu_assign_pointer(found->pub.ies, 842 tmp->pub.proberesp_ies); 843 if (old) 844 kfree_rcu((struct cfg80211_bss_ies *)old, 845 rcu_head); 846 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) { 847 const struct cfg80211_bss_ies *old; 848 struct cfg80211_internal_bss *bss; 849 850 if (found->pub.hidden_beacon_bss && 851 !list_empty(&found->hidden_list)) { 852 const struct cfg80211_bss_ies *f; 853 854 /* 855 * The found BSS struct is one of the probe 856 * response members of a group, but we're 857 * receiving a beacon (beacon_ies in the tmp 858 * bss is used). This can only mean that the 859 * AP changed its beacon from not having an 860 * SSID to showing it, which is confusing so 861 * drop this information. 862 */ 863 864 f = rcu_access_pointer(tmp->pub.beacon_ies); 865 kfree_rcu((struct cfg80211_bss_ies *)f, 866 rcu_head); 867 goto drop; 868 } 869 870 old = rcu_access_pointer(found->pub.beacon_ies); 871 872 rcu_assign_pointer(found->pub.beacon_ies, 873 tmp->pub.beacon_ies); 874 875 /* Override IEs if they were from a beacon before */ 876 if (old == rcu_access_pointer(found->pub.ies)) 877 rcu_assign_pointer(found->pub.ies, 878 tmp->pub.beacon_ies); 879 880 /* Assign beacon IEs to all sub entries */ 881 list_for_each_entry(bss, &found->hidden_list, 882 hidden_list) { 883 const struct cfg80211_bss_ies *ies; 884 885 ies = rcu_access_pointer(bss->pub.beacon_ies); 886 WARN_ON(ies != old); 887 888 rcu_assign_pointer(bss->pub.beacon_ies, 889 tmp->pub.beacon_ies); 890 } 891 892 if (old) 893 kfree_rcu((struct cfg80211_bss_ies *)old, 894 rcu_head); 895 } 896 897 found->pub.beacon_interval = tmp->pub.beacon_interval; 898 /* 899 * don't update the signal if beacon was heard on 900 * adjacent channel. 901 */ 902 if (signal_valid) 903 found->pub.signal = tmp->pub.signal; 904 found->pub.capability = tmp->pub.capability; 905 found->ts = tmp->ts; 906 found->ts_boottime = tmp->ts_boottime; 907 found->parent_tsf = tmp->parent_tsf; 908 ether_addr_copy(found->parent_bssid, tmp->parent_bssid); 909 } else { 910 struct cfg80211_internal_bss *new; 911 struct cfg80211_internal_bss *hidden; 912 struct cfg80211_bss_ies *ies; 913 914 /* 915 * create a copy -- the "res" variable that is passed in 916 * is allocated on the stack since it's not needed in the 917 * more common case of an update 918 */ 919 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size, 920 GFP_ATOMIC); 921 if (!new) { 922 ies = (void *)rcu_dereference(tmp->pub.beacon_ies); 923 if (ies) 924 kfree_rcu(ies, rcu_head); 925 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies); 926 if (ies) 927 kfree_rcu(ies, rcu_head); 928 goto drop; 929 } 930 memcpy(new, tmp, sizeof(*new)); 931 new->refcount = 1; 932 INIT_LIST_HEAD(&new->hidden_list); 933 934 if (rcu_access_pointer(tmp->pub.proberesp_ies)) { 935 hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); 936 if (!hidden) 937 hidden = rb_find_bss(rdev, tmp, 938 BSS_CMP_HIDE_NUL); 939 if (hidden) { 940 new->pub.hidden_beacon_bss = &hidden->pub; 941 list_add(&new->hidden_list, 942 &hidden->hidden_list); 943 hidden->refcount++; 944 rcu_assign_pointer(new->pub.beacon_ies, 945 hidden->pub.beacon_ies); 946 } 947 } else { 948 /* 949 * Ok so we found a beacon, and don't have an entry. If 950 * it's a beacon with hidden SSID, we might be in for an 951 * expensive search for any probe responses that should 952 * be grouped with this beacon for updates ... 953 */ 954 if (!cfg80211_combine_bsses(rdev, new)) { 955 kfree(new); 956 goto drop; 957 } 958 } 959 960 if (rdev->bss_entries >= bss_entries_limit && 961 !cfg80211_bss_expire_oldest(rdev)) { 962 kfree(new); 963 goto drop; 964 } 965 966 list_add_tail(&new->list, &rdev->bss_list); 967 rdev->bss_entries++; 968 rb_insert_bss(rdev, new); 969 found = new; 970 } 971 972 rdev->bss_generation++; 973 bss_ref_get(rdev, found); 974 spin_unlock_bh(&rdev->bss_lock); 975 976 return found; 977 drop: 978 spin_unlock_bh(&rdev->bss_lock); 979 return NULL; 980 } 981 982 static struct ieee80211_channel * 983 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, 984 struct ieee80211_channel *channel) 985 { 986 const u8 *tmp; 987 u32 freq; 988 int channel_number = -1; 989 990 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen); 991 if (tmp && tmp[1] == 1) { 992 channel_number = tmp[2]; 993 } else { 994 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen); 995 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) { 996 struct ieee80211_ht_operation *htop = (void *)(tmp + 2); 997 998 channel_number = htop->primary_chan; 999 } 1000 } 1001 1002 if (channel_number < 0) 1003 return channel; 1004 1005 freq = ieee80211_channel_to_frequency(channel_number, channel->band); 1006 channel = ieee80211_get_channel(wiphy, freq); 1007 if (!channel) 1008 return NULL; 1009 if (channel->flags & IEEE80211_CHAN_DISABLED) 1010 return NULL; 1011 return channel; 1012 } 1013 1014 /* Returned bss is reference counted and must be cleaned up appropriately. */ 1015 struct cfg80211_bss * 1016 cfg80211_inform_bss_data(struct wiphy *wiphy, 1017 struct cfg80211_inform_bss *data, 1018 enum cfg80211_bss_frame_type ftype, 1019 const u8 *bssid, u64 tsf, u16 capability, 1020 u16 beacon_interval, const u8 *ie, size_t ielen, 1021 gfp_t gfp) 1022 { 1023 struct cfg80211_bss_ies *ies; 1024 struct ieee80211_channel *channel; 1025 struct cfg80211_internal_bss tmp = {}, *res; 1026 int bss_type; 1027 bool signal_valid; 1028 1029 if (WARN_ON(!wiphy)) 1030 return NULL; 1031 1032 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 1033 (data->signal < 0 || data->signal > 100))) 1034 return NULL; 1035 1036 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan); 1037 if (!channel) 1038 return NULL; 1039 1040 memcpy(tmp.pub.bssid, bssid, ETH_ALEN); 1041 tmp.pub.channel = channel; 1042 tmp.pub.scan_width = data->scan_width; 1043 tmp.pub.signal = data->signal; 1044 tmp.pub.beacon_interval = beacon_interval; 1045 tmp.pub.capability = capability; 1046 tmp.ts_boottime = data->boottime_ns; 1047 1048 /* 1049 * If we do not know here whether the IEs are from a Beacon or Probe 1050 * Response frame, we need to pick one of the options and only use it 1051 * with the driver that does not provide the full Beacon/Probe Response 1052 * frame. Use Beacon frame pointer to avoid indicating that this should 1053 * override the IEs pointer should we have received an earlier 1054 * indication of Probe Response data. 1055 */ 1056 ies = kzalloc(sizeof(*ies) + ielen, gfp); 1057 if (!ies) 1058 return NULL; 1059 ies->len = ielen; 1060 ies->tsf = tsf; 1061 ies->from_beacon = false; 1062 memcpy(ies->data, ie, ielen); 1063 1064 switch (ftype) { 1065 case CFG80211_BSS_FTYPE_BEACON: 1066 ies->from_beacon = true; 1067 /* fall through to assign */ 1068 case CFG80211_BSS_FTYPE_UNKNOWN: 1069 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 1070 break; 1071 case CFG80211_BSS_FTYPE_PRESP: 1072 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 1073 break; 1074 } 1075 rcu_assign_pointer(tmp.pub.ies, ies); 1076 1077 signal_valid = abs(data->chan->center_freq - channel->center_freq) <= 1078 wiphy->max_adj_channel_rssi_comp; 1079 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid); 1080 if (!res) 1081 return NULL; 1082 1083 if (channel->band == NL80211_BAND_60GHZ) { 1084 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 1085 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 1086 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 1087 regulatory_hint_found_beacon(wiphy, channel, gfp); 1088 } else { 1089 if (res->pub.capability & WLAN_CAPABILITY_ESS) 1090 regulatory_hint_found_beacon(wiphy, channel, gfp); 1091 } 1092 1093 trace_cfg80211_return_bss(&res->pub); 1094 /* cfg80211_bss_update gives us a referenced result */ 1095 return &res->pub; 1096 } 1097 EXPORT_SYMBOL(cfg80211_inform_bss_data); 1098 1099 /* cfg80211_inform_bss_width_frame helper */ 1100 struct cfg80211_bss * 1101 cfg80211_inform_bss_frame_data(struct wiphy *wiphy, 1102 struct cfg80211_inform_bss *data, 1103 struct ieee80211_mgmt *mgmt, size_t len, 1104 gfp_t gfp) 1105 1106 { 1107 struct cfg80211_internal_bss tmp = {}, *res; 1108 struct cfg80211_bss_ies *ies; 1109 struct ieee80211_channel *channel; 1110 bool signal_valid; 1111 size_t ielen = len - offsetof(struct ieee80211_mgmt, 1112 u.probe_resp.variable); 1113 int bss_type; 1114 1115 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) != 1116 offsetof(struct ieee80211_mgmt, u.beacon.variable)); 1117 1118 trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len); 1119 1120 if (WARN_ON(!mgmt)) 1121 return NULL; 1122 1123 if (WARN_ON(!wiphy)) 1124 return NULL; 1125 1126 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && 1127 (data->signal < 0 || data->signal > 100))) 1128 return NULL; 1129 1130 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable))) 1131 return NULL; 1132 1133 channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable, 1134 ielen, data->chan); 1135 if (!channel) 1136 return NULL; 1137 1138 ies = kzalloc(sizeof(*ies) + ielen, gfp); 1139 if (!ies) 1140 return NULL; 1141 ies->len = ielen; 1142 ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); 1143 ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); 1144 memcpy(ies->data, mgmt->u.probe_resp.variable, ielen); 1145 1146 if (ieee80211_is_probe_resp(mgmt->frame_control)) 1147 rcu_assign_pointer(tmp.pub.proberesp_ies, ies); 1148 else 1149 rcu_assign_pointer(tmp.pub.beacon_ies, ies); 1150 rcu_assign_pointer(tmp.pub.ies, ies); 1151 1152 memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN); 1153 tmp.pub.channel = channel; 1154 tmp.pub.scan_width = data->scan_width; 1155 tmp.pub.signal = data->signal; 1156 tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); 1157 tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); 1158 tmp.ts_boottime = data->boottime_ns; 1159 tmp.parent_tsf = data->parent_tsf; 1160 ether_addr_copy(tmp.parent_bssid, data->parent_bssid); 1161 1162 signal_valid = abs(data->chan->center_freq - channel->center_freq) <= 1163 wiphy->max_adj_channel_rssi_comp; 1164 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid); 1165 if (!res) 1166 return NULL; 1167 1168 if (channel->band == NL80211_BAND_60GHZ) { 1169 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; 1170 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || 1171 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) 1172 regulatory_hint_found_beacon(wiphy, channel, gfp); 1173 } else { 1174 if (res->pub.capability & WLAN_CAPABILITY_ESS) 1175 regulatory_hint_found_beacon(wiphy, channel, gfp); 1176 } 1177 1178 trace_cfg80211_return_bss(&res->pub); 1179 /* cfg80211_bss_update gives us a referenced result */ 1180 return &res->pub; 1181 } 1182 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data); 1183 1184 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1185 { 1186 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1187 struct cfg80211_internal_bss *bss; 1188 1189 if (!pub) 1190 return; 1191 1192 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1193 1194 spin_lock_bh(&rdev->bss_lock); 1195 bss_ref_get(rdev, bss); 1196 spin_unlock_bh(&rdev->bss_lock); 1197 } 1198 EXPORT_SYMBOL(cfg80211_ref_bss); 1199 1200 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1201 { 1202 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1203 struct cfg80211_internal_bss *bss; 1204 1205 if (!pub) 1206 return; 1207 1208 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1209 1210 spin_lock_bh(&rdev->bss_lock); 1211 bss_ref_put(rdev, bss); 1212 spin_unlock_bh(&rdev->bss_lock); 1213 } 1214 EXPORT_SYMBOL(cfg80211_put_bss); 1215 1216 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) 1217 { 1218 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); 1219 struct cfg80211_internal_bss *bss; 1220 1221 if (WARN_ON(!pub)) 1222 return; 1223 1224 bss = container_of(pub, struct cfg80211_internal_bss, pub); 1225 1226 spin_lock_bh(&rdev->bss_lock); 1227 if (!list_empty(&bss->list)) { 1228 if (__cfg80211_unlink_bss(rdev, bss)) 1229 rdev->bss_generation++; 1230 } 1231 spin_unlock_bh(&rdev->bss_lock); 1232 } 1233 EXPORT_SYMBOL(cfg80211_unlink_bss); 1234 1235 #ifdef CONFIG_CFG80211_WEXT 1236 static struct cfg80211_registered_device * 1237 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) 1238 { 1239 struct cfg80211_registered_device *rdev; 1240 struct net_device *dev; 1241 1242 ASSERT_RTNL(); 1243 1244 dev = dev_get_by_index(net, ifindex); 1245 if (!dev) 1246 return ERR_PTR(-ENODEV); 1247 if (dev->ieee80211_ptr) 1248 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy); 1249 else 1250 rdev = ERR_PTR(-ENODEV); 1251 dev_put(dev); 1252 return rdev; 1253 } 1254 1255 int cfg80211_wext_siwscan(struct net_device *dev, 1256 struct iw_request_info *info, 1257 union iwreq_data *wrqu, char *extra) 1258 { 1259 struct cfg80211_registered_device *rdev; 1260 struct wiphy *wiphy; 1261 struct iw_scan_req *wreq = NULL; 1262 struct cfg80211_scan_request *creq = NULL; 1263 int i, err, n_channels = 0; 1264 enum nl80211_band band; 1265 1266 if (!netif_running(dev)) 1267 return -ENETDOWN; 1268 1269 if (wrqu->data.length == sizeof(struct iw_scan_req)) 1270 wreq = (struct iw_scan_req *)extra; 1271 1272 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 1273 1274 if (IS_ERR(rdev)) 1275 return PTR_ERR(rdev); 1276 1277 if (rdev->scan_req || rdev->scan_msg) { 1278 err = -EBUSY; 1279 goto out; 1280 } 1281 1282 wiphy = &rdev->wiphy; 1283 1284 /* Determine number of channels, needed to allocate creq */ 1285 if (wreq && wreq->num_channels) 1286 n_channels = wreq->num_channels; 1287 else 1288 n_channels = ieee80211_get_num_supported_channels(wiphy); 1289 1290 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + 1291 n_channels * sizeof(void *), 1292 GFP_ATOMIC); 1293 if (!creq) { 1294 err = -ENOMEM; 1295 goto out; 1296 } 1297 1298 creq->wiphy = wiphy; 1299 creq->wdev = dev->ieee80211_ptr; 1300 /* SSIDs come after channels */ 1301 creq->ssids = (void *)&creq->channels[n_channels]; 1302 creq->n_channels = n_channels; 1303 creq->n_ssids = 1; 1304 creq->scan_start = jiffies; 1305 1306 /* translate "Scan on frequencies" request */ 1307 i = 0; 1308 for (band = 0; band < NUM_NL80211_BANDS; band++) { 1309 int j; 1310 1311 if (!wiphy->bands[band]) 1312 continue; 1313 1314 for (j = 0; j < wiphy->bands[band]->n_channels; j++) { 1315 /* ignore disabled channels */ 1316 if (wiphy->bands[band]->channels[j].flags & 1317 IEEE80211_CHAN_DISABLED) 1318 continue; 1319 1320 /* If we have a wireless request structure and the 1321 * wireless request specifies frequencies, then search 1322 * for the matching hardware channel. 1323 */ 1324 if (wreq && wreq->num_channels) { 1325 int k; 1326 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq; 1327 for (k = 0; k < wreq->num_channels; k++) { 1328 struct iw_freq *freq = 1329 &wreq->channel_list[k]; 1330 int wext_freq = 1331 cfg80211_wext_freq(freq); 1332 1333 if (wext_freq == wiphy_freq) 1334 goto wext_freq_found; 1335 } 1336 goto wext_freq_not_found; 1337 } 1338 1339 wext_freq_found: 1340 creq->channels[i] = &wiphy->bands[band]->channels[j]; 1341 i++; 1342 wext_freq_not_found: ; 1343 } 1344 } 1345 /* No channels found? */ 1346 if (!i) { 1347 err = -EINVAL; 1348 goto out; 1349 } 1350 1351 /* Set real number of channels specified in creq->channels[] */ 1352 creq->n_channels = i; 1353 1354 /* translate "Scan for SSID" request */ 1355 if (wreq) { 1356 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) { 1357 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) { 1358 err = -EINVAL; 1359 goto out; 1360 } 1361 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); 1362 creq->ssids[0].ssid_len = wreq->essid_len; 1363 } 1364 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) 1365 creq->n_ssids = 0; 1366 } 1367 1368 for (i = 0; i < NUM_NL80211_BANDS; i++) 1369 if (wiphy->bands[i]) 1370 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; 1371 1372 eth_broadcast_addr(creq->bssid); 1373 1374 rdev->scan_req = creq; 1375 err = rdev_scan(rdev, creq); 1376 if (err) { 1377 rdev->scan_req = NULL; 1378 /* creq will be freed below */ 1379 } else { 1380 nl80211_send_scan_start(rdev, dev->ieee80211_ptr); 1381 /* creq now owned by driver */ 1382 creq = NULL; 1383 dev_hold(dev); 1384 } 1385 out: 1386 kfree(creq); 1387 return err; 1388 } 1389 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan); 1390 1391 static char *ieee80211_scan_add_ies(struct iw_request_info *info, 1392 const struct cfg80211_bss_ies *ies, 1393 char *current_ev, char *end_buf) 1394 { 1395 const u8 *pos, *end, *next; 1396 struct iw_event iwe; 1397 1398 if (!ies) 1399 return current_ev; 1400 1401 /* 1402 * If needed, fragment the IEs buffer (at IE boundaries) into short 1403 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. 1404 */ 1405 pos = ies->data; 1406 end = pos + ies->len; 1407 1408 while (end - pos > IW_GENERIC_IE_MAX) { 1409 next = pos + 2 + pos[1]; 1410 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) 1411 next = next + 2 + next[1]; 1412 1413 memset(&iwe, 0, sizeof(iwe)); 1414 iwe.cmd = IWEVGENIE; 1415 iwe.u.data.length = next - pos; 1416 current_ev = iwe_stream_add_point_check(info, current_ev, 1417 end_buf, &iwe, 1418 (void *)pos); 1419 if (IS_ERR(current_ev)) 1420 return current_ev; 1421 pos = next; 1422 } 1423 1424 if (end > pos) { 1425 memset(&iwe, 0, sizeof(iwe)); 1426 iwe.cmd = IWEVGENIE; 1427 iwe.u.data.length = end - pos; 1428 current_ev = iwe_stream_add_point_check(info, current_ev, 1429 end_buf, &iwe, 1430 (void *)pos); 1431 if (IS_ERR(current_ev)) 1432 return current_ev; 1433 } 1434 1435 return current_ev; 1436 } 1437 1438 static char * 1439 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, 1440 struct cfg80211_internal_bss *bss, char *current_ev, 1441 char *end_buf) 1442 { 1443 const struct cfg80211_bss_ies *ies; 1444 struct iw_event iwe; 1445 const u8 *ie; 1446 u8 buf[50]; 1447 u8 *cfg, *p, *tmp; 1448 int rem, i, sig; 1449 bool ismesh = false; 1450 1451 memset(&iwe, 0, sizeof(iwe)); 1452 iwe.cmd = SIOCGIWAP; 1453 iwe.u.ap_addr.sa_family = ARPHRD_ETHER; 1454 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN); 1455 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 1456 IW_EV_ADDR_LEN); 1457 if (IS_ERR(current_ev)) 1458 return current_ev; 1459 1460 memset(&iwe, 0, sizeof(iwe)); 1461 iwe.cmd = SIOCGIWFREQ; 1462 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq); 1463 iwe.u.freq.e = 0; 1464 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 1465 IW_EV_FREQ_LEN); 1466 if (IS_ERR(current_ev)) 1467 return current_ev; 1468 1469 memset(&iwe, 0, sizeof(iwe)); 1470 iwe.cmd = SIOCGIWFREQ; 1471 iwe.u.freq.m = bss->pub.channel->center_freq; 1472 iwe.u.freq.e = 6; 1473 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, 1474 IW_EV_FREQ_LEN); 1475 if (IS_ERR(current_ev)) 1476 return current_ev; 1477 1478 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) { 1479 memset(&iwe, 0, sizeof(iwe)); 1480 iwe.cmd = IWEVQUAL; 1481 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED | 1482 IW_QUAL_NOISE_INVALID | 1483 IW_QUAL_QUAL_UPDATED; 1484 switch (wiphy->signal_type) { 1485 case CFG80211_SIGNAL_TYPE_MBM: 1486 sig = bss->pub.signal / 100; 1487 iwe.u.qual.level = sig; 1488 iwe.u.qual.updated |= IW_QUAL_DBM; 1489 if (sig < -110) /* rather bad */ 1490 sig = -110; 1491 else if (sig > -40) /* perfect */ 1492 sig = -40; 1493 /* will give a range of 0 .. 70 */ 1494 iwe.u.qual.qual = sig + 110; 1495 break; 1496 case CFG80211_SIGNAL_TYPE_UNSPEC: 1497 iwe.u.qual.level = bss->pub.signal; 1498 /* will give range 0 .. 100 */ 1499 iwe.u.qual.qual = bss->pub.signal; 1500 break; 1501 default: 1502 /* not reached */ 1503 break; 1504 } 1505 current_ev = iwe_stream_add_event_check(info, current_ev, 1506 end_buf, &iwe, 1507 IW_EV_QUAL_LEN); 1508 if (IS_ERR(current_ev)) 1509 return current_ev; 1510 } 1511 1512 memset(&iwe, 0, sizeof(iwe)); 1513 iwe.cmd = SIOCGIWENCODE; 1514 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY) 1515 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; 1516 else 1517 iwe.u.data.flags = IW_ENCODE_DISABLED; 1518 iwe.u.data.length = 0; 1519 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 1520 &iwe, ""); 1521 if (IS_ERR(current_ev)) 1522 return current_ev; 1523 1524 rcu_read_lock(); 1525 ies = rcu_dereference(bss->pub.ies); 1526 rem = ies->len; 1527 ie = ies->data; 1528 1529 while (rem >= 2) { 1530 /* invalid data */ 1531 if (ie[1] > rem - 2) 1532 break; 1533 1534 switch (ie[0]) { 1535 case WLAN_EID_SSID: 1536 memset(&iwe, 0, sizeof(iwe)); 1537 iwe.cmd = SIOCGIWESSID; 1538 iwe.u.data.length = ie[1]; 1539 iwe.u.data.flags = 1; 1540 current_ev = iwe_stream_add_point_check(info, 1541 current_ev, 1542 end_buf, &iwe, 1543 (u8 *)ie + 2); 1544 if (IS_ERR(current_ev)) 1545 goto unlock; 1546 break; 1547 case WLAN_EID_MESH_ID: 1548 memset(&iwe, 0, sizeof(iwe)); 1549 iwe.cmd = SIOCGIWESSID; 1550 iwe.u.data.length = ie[1]; 1551 iwe.u.data.flags = 1; 1552 current_ev = iwe_stream_add_point_check(info, 1553 current_ev, 1554 end_buf, &iwe, 1555 (u8 *)ie + 2); 1556 if (IS_ERR(current_ev)) 1557 goto unlock; 1558 break; 1559 case WLAN_EID_MESH_CONFIG: 1560 ismesh = true; 1561 if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) 1562 break; 1563 cfg = (u8 *)ie + 2; 1564 memset(&iwe, 0, sizeof(iwe)); 1565 iwe.cmd = IWEVCUSTOM; 1566 sprintf(buf, "Mesh Network Path Selection Protocol ID: " 1567 "0x%02X", cfg[0]); 1568 iwe.u.data.length = strlen(buf); 1569 current_ev = iwe_stream_add_point_check(info, 1570 current_ev, 1571 end_buf, 1572 &iwe, buf); 1573 if (IS_ERR(current_ev)) 1574 goto unlock; 1575 sprintf(buf, "Path Selection Metric ID: 0x%02X", 1576 cfg[1]); 1577 iwe.u.data.length = strlen(buf); 1578 current_ev = iwe_stream_add_point_check(info, 1579 current_ev, 1580 end_buf, 1581 &iwe, buf); 1582 if (IS_ERR(current_ev)) 1583 goto unlock; 1584 sprintf(buf, "Congestion Control Mode ID: 0x%02X", 1585 cfg[2]); 1586 iwe.u.data.length = strlen(buf); 1587 current_ev = iwe_stream_add_point_check(info, 1588 current_ev, 1589 end_buf, 1590 &iwe, buf); 1591 if (IS_ERR(current_ev)) 1592 goto unlock; 1593 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]); 1594 iwe.u.data.length = strlen(buf); 1595 current_ev = iwe_stream_add_point_check(info, 1596 current_ev, 1597 end_buf, 1598 &iwe, buf); 1599 if (IS_ERR(current_ev)) 1600 goto unlock; 1601 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]); 1602 iwe.u.data.length = strlen(buf); 1603 current_ev = iwe_stream_add_point_check(info, 1604 current_ev, 1605 end_buf, 1606 &iwe, buf); 1607 if (IS_ERR(current_ev)) 1608 goto unlock; 1609 sprintf(buf, "Formation Info: 0x%02X", cfg[5]); 1610 iwe.u.data.length = strlen(buf); 1611 current_ev = iwe_stream_add_point_check(info, 1612 current_ev, 1613 end_buf, 1614 &iwe, buf); 1615 if (IS_ERR(current_ev)) 1616 goto unlock; 1617 sprintf(buf, "Capabilities: 0x%02X", cfg[6]); 1618 iwe.u.data.length = strlen(buf); 1619 current_ev = iwe_stream_add_point_check(info, 1620 current_ev, 1621 end_buf, 1622 &iwe, buf); 1623 if (IS_ERR(current_ev)) 1624 goto unlock; 1625 break; 1626 case WLAN_EID_SUPP_RATES: 1627 case WLAN_EID_EXT_SUPP_RATES: 1628 /* display all supported rates in readable format */ 1629 p = current_ev + iwe_stream_lcp_len(info); 1630 1631 memset(&iwe, 0, sizeof(iwe)); 1632 iwe.cmd = SIOCGIWRATE; 1633 /* Those two flags are ignored... */ 1634 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; 1635 1636 for (i = 0; i < ie[1]; i++) { 1637 iwe.u.bitrate.value = 1638 ((ie[i + 2] & 0x7f) * 500000); 1639 tmp = p; 1640 p = iwe_stream_add_value(info, current_ev, p, 1641 end_buf, &iwe, 1642 IW_EV_PARAM_LEN); 1643 if (p == tmp) { 1644 current_ev = ERR_PTR(-E2BIG); 1645 goto unlock; 1646 } 1647 } 1648 current_ev = p; 1649 break; 1650 } 1651 rem -= ie[1] + 2; 1652 ie += ie[1] + 2; 1653 } 1654 1655 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) || 1656 ismesh) { 1657 memset(&iwe, 0, sizeof(iwe)); 1658 iwe.cmd = SIOCGIWMODE; 1659 if (ismesh) 1660 iwe.u.mode = IW_MODE_MESH; 1661 else if (bss->pub.capability & WLAN_CAPABILITY_ESS) 1662 iwe.u.mode = IW_MODE_MASTER; 1663 else 1664 iwe.u.mode = IW_MODE_ADHOC; 1665 current_ev = iwe_stream_add_event_check(info, current_ev, 1666 end_buf, &iwe, 1667 IW_EV_UINT_LEN); 1668 if (IS_ERR(current_ev)) 1669 goto unlock; 1670 } 1671 1672 memset(&iwe, 0, sizeof(iwe)); 1673 iwe.cmd = IWEVCUSTOM; 1674 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf)); 1675 iwe.u.data.length = strlen(buf); 1676 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, 1677 &iwe, buf); 1678 if (IS_ERR(current_ev)) 1679 goto unlock; 1680 memset(&iwe, 0, sizeof(iwe)); 1681 iwe.cmd = IWEVCUSTOM; 1682 sprintf(buf, " Last beacon: %ums ago", 1683 elapsed_jiffies_msecs(bss->ts)); 1684 iwe.u.data.length = strlen(buf); 1685 current_ev = iwe_stream_add_point_check(info, current_ev, 1686 end_buf, &iwe, buf); 1687 if (IS_ERR(current_ev)) 1688 goto unlock; 1689 1690 current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf); 1691 1692 unlock: 1693 rcu_read_unlock(); 1694 return current_ev; 1695 } 1696 1697 1698 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev, 1699 struct iw_request_info *info, 1700 char *buf, size_t len) 1701 { 1702 char *current_ev = buf; 1703 char *end_buf = buf + len; 1704 struct cfg80211_internal_bss *bss; 1705 int err = 0; 1706 1707 spin_lock_bh(&rdev->bss_lock); 1708 cfg80211_bss_expire(rdev); 1709 1710 list_for_each_entry(bss, &rdev->bss_list, list) { 1711 if (buf + len - current_ev <= IW_EV_ADDR_LEN) { 1712 err = -E2BIG; 1713 break; 1714 } 1715 current_ev = ieee80211_bss(&rdev->wiphy, info, bss, 1716 current_ev, end_buf); 1717 if (IS_ERR(current_ev)) { 1718 err = PTR_ERR(current_ev); 1719 break; 1720 } 1721 } 1722 spin_unlock_bh(&rdev->bss_lock); 1723 1724 if (err) 1725 return err; 1726 return current_ev - buf; 1727 } 1728 1729 1730 int cfg80211_wext_giwscan(struct net_device *dev, 1731 struct iw_request_info *info, 1732 struct iw_point *data, char *extra) 1733 { 1734 struct cfg80211_registered_device *rdev; 1735 int res; 1736 1737 if (!netif_running(dev)) 1738 return -ENETDOWN; 1739 1740 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); 1741 1742 if (IS_ERR(rdev)) 1743 return PTR_ERR(rdev); 1744 1745 if (rdev->scan_req || rdev->scan_msg) 1746 return -EAGAIN; 1747 1748 res = ieee80211_scan_results(rdev, info, extra, data->length); 1749 data->length = 0; 1750 if (res >= 0) { 1751 data->length = res; 1752 res = 0; 1753 } 1754 1755 return res; 1756 } 1757 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan); 1758 #endif 1759