net/wireless/scan.c

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