net/wireless/scan.c

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