kernel/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  */
   7 #include <linux/kernel.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/wireless.h>
  12 #include <linux/nl80211.h>
  13 #include <linux/etherdevice.h>
  14 #include <net/arp.h>
  15 #include <net/cfg80211.h>
  16 #include <net/cfg80211-wext.h>
  17 #include <net/iw_handler.h>
  18 #include "core.h"
  19 #include "nl80211.h"
  20 #include "wext-compat.h"
  21 #include "rdev-ops.h"
  22
  23 /**
  24  * DOC: BSS tree/list structure
  25  *
  26  * At the top level, the BSS list is kept in both a list in each
  27  * registered device (@bss_list) as well as an RB-tree for faster
  28  * lookup. In the RB-tree, entries can be looked up using their
  29  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  30  * for other BSSes.
  31  *
  32  * Due to the possibility of hidden SSIDs, there's a second level
  33  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  34  * The hidden_list connects all BSSes belonging to a single AP
  35  * that has a hidden SSID, and connects beacon and probe response
  36  * entries. For a probe response entry for a hidden SSID, the
  37  * hidden_beacon_bss pointer points to the BSS struct holding the
  38  * beacon's information.
  39  *
  40  * Reference counting is done for all these references except for
  41  * the hidden_list, so that a beacon BSS struct that is otherwise
  42  * not referenced has one reference for being on the bss_list and
  43  * one for each probe response entry that points to it using the
  44  * hidden_beacon_bss pointer. When a BSS struct that has such a
  45  * pointer is get/put, the refcount update is also propagated to
  46  * the referenced struct, this ensure that it cannot get removed
  47  * while somebody is using the probe response version.
  48  *
  49  * Note that the hidden_beacon_bss pointer never changes, due to
  50  * the reference counting. Therefore, no locking is needed for
  51  * it.
  52  *
  53  * Also note that the hidden_beacon_bss pointer is only relevant
  54  * if the driver uses something other than the IEs, e.g. private
  55  * data stored stored in the BSS struct, since the beacon IEs are
  56  * also linked into the probe response struct.
  57  */
  58
  59 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  60
  61 static void bss_free(struct cfg80211_internal_bss *bss)
  62 {
  63         struct cfg80211_bss_ies *ies;
  64
  65         if (WARN_ON(atomic_read(&bss->hold)))
  66                 return;
  67
  68         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  69         if (ies && !bss->pub.hidden_beacon_bss)
  70                 kfree_rcu(ies, rcu_head);
  71         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  72         if (ies)
  73                 kfree_rcu(ies, rcu_head);
  74
  75         /*
  76          * This happens when the module is removed, it doesn't
  77          * really matter any more save for completeness
  78          */
  79         if (!list_empty(&bss->hidden_list))
  80                 list_del(&bss->hidden_list);
  81
  82         kfree(bss);
  83 }
  84
  85 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
  86                                struct cfg80211_internal_bss *bss)
  87 {
  88         lockdep_assert_held(&rdev->bss_lock);
  89
  90         bss->refcount++;
  91         if (bss->pub.hidden_beacon_bss) {
  92                 bss = container_of(bss->pub.hidden_beacon_bss,
  93                                    struct cfg80211_internal_bss,
  94                                    pub);
  95                 bss->refcount++;
  96         }
  97 }
  98
  99 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
 100                                struct cfg80211_internal_bss *bss)
 101 {
 102         lockdep_assert_held(&rdev->bss_lock);
 103
 104         if (bss->pub.hidden_beacon_bss) {
 105                 struct cfg80211_internal_bss *hbss;
 106                 hbss = container_of(bss->pub.hidden_beacon_bss,
 107                                     struct cfg80211_internal_bss,
 108                                     pub);
 109                 hbss->refcount--;
 110                 if (hbss->refcount == 0)
 111                         bss_free(hbss);
 112         }
 113         bss->refcount--;
 114         if (bss->refcount == 0)
 115                 bss_free(bss);
 116 }
 117
 118 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 119                                   struct cfg80211_internal_bss *bss)
 120 {
 121         lockdep_assert_held(&rdev->bss_lock);
 122
 123         if (!list_empty(&bss->hidden_list)) {
 124                 /*
 125                  * don't remove the beacon entry if it has
 126                  * probe responses associated with it
 127                  */
 128                 if (!bss->pub.hidden_beacon_bss)
 129                         return false;
 130                 /*
 131                  * if it's a probe response entry break its
 132                  * link to the other entries in the group
 133                  */
 134                 list_del_init(&bss->hidden_list);
 135         }
 136
 137         list_del_init(&bss->list);
 138         rb_erase(&bss->rbn, &rdev->bss_tree);
 139         bss_ref_put(rdev, bss);
 140         return true;
 141 }
 142
 143 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 144                                   unsigned long expire_time)
 145 {
 146         struct cfg80211_internal_bss *bss, *tmp;
 147         bool expired = false;
 148
 149         lockdep_assert_held(&rdev->bss_lock);
 150
 151         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
 152                 if (atomic_read(&bss->hold))
 153                         continue;
 154                 if (!time_after(expire_time, bss->ts))
 155                         continue;
 156
 157                 if (__cfg80211_unlink_bss(rdev, bss))
 158                         expired = true;
 159         }
 160
 161         if (expired)
 162                 rdev->bss_generation++;
 163 }
 164
 165 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 166                            bool send_message)
 167 {
 168         struct cfg80211_scan_request *request;
 169         struct wireless_dev *wdev;
 170         struct sk_buff *msg;
 171 #ifdef CONFIG_CFG80211_WEXT
 172         union iwreq_data wrqu;
 173 #endif
 174
 175         ASSERT_RTNL();
 176
 177         if (rdev->scan_msg) {
 178                 nl80211_send_scan_result(rdev, rdev->scan_msg);
 179                 rdev->scan_msg = NULL;
 180                 return;
 181         }
 182
 183         request = rdev->scan_req;
 184         if (!request)
 185                 return;
 186
 187         wdev = request->wdev;
 188
 189         /*
 190          * This must be before sending the other events!
 191          * Otherwise, wpa_supplicant gets completely confused with
 192          * wext events.
 193          */
 194         if (wdev->netdev)
 195                 cfg80211_sme_scan_done(wdev->netdev);
 196
 197         if (!request->aborted &&
 198             request->flags & NL80211_SCAN_FLAG_FLUSH) {
 199                 /* flush entries from previous scans */
 200                 spin_lock_bh(&rdev->bss_lock);
 201                 __cfg80211_bss_expire(rdev, request->scan_start);
 202                 spin_unlock_bh(&rdev->bss_lock);
 203         }
 204
 205         msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
 206
 207 #ifdef CONFIG_CFG80211_WEXT
 208         if (wdev->netdev && !request->aborted) {
 209                 memset(&wrqu, 0, sizeof(wrqu));
 210
 211                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 212         }
 213 #endif
 214
 215         if (wdev->netdev)
 216                 dev_put(wdev->netdev);
 217
 218         rdev->scan_req = NULL;
 219         kfree(request);
 220
 221         if (!send_message)
 222                 rdev->scan_msg = msg;
 223         else
 224                 nl80211_send_scan_result(rdev, msg);
 225 }
 226
 227 void __cfg80211_scan_done(struct work_struct *wk)
 228 {
 229         struct cfg80211_registered_device *rdev;
 230
 231         rdev = container_of(wk, struct cfg80211_registered_device,
 232                             scan_done_wk);
 233
 234         rtnl_lock();
 235         ___cfg80211_scan_done(rdev, true);
 236         rtnl_unlock();
 237 }
 238
 239 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 240 {
 241         trace_cfg80211_scan_done(request, aborted);
 242         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
 243
 244         request->aborted = aborted;
 245         request->notified = true;
 246         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
 247 }
 248 EXPORT_SYMBOL(cfg80211_scan_done);
 249
 250 void __cfg80211_sched_scan_results(struct work_struct *wk)
 251 {
 252         struct cfg80211_registered_device *rdev;
 253         struct cfg80211_sched_scan_request *request;
 254
 255         rdev = container_of(wk, struct cfg80211_registered_device,
 256                             sched_scan_results_wk);
 257
 258         rtnl_lock();
 259
 260         request = rtnl_dereference(rdev->sched_scan_req);
 261
 262         /* we don't have sched_scan_req anymore if the scan is stopping */
 263         if (request) {
 264                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 265                         /* flush entries from previous scans */
 266                         spin_lock_bh(&rdev->bss_lock);
 267                         __cfg80211_bss_expire(rdev, request->scan_start);
 268                         spin_unlock_bh(&rdev->bss_lock);
 269                         request->scan_start =
 270                                 jiffies + msecs_to_jiffies(request->interval);
 271                 }
 272                 nl80211_send_sched_scan_results(rdev, request->dev);
 273         }
 274
 275         rtnl_unlock();
 276 }
 277
 278 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 279 {
 280         trace_cfg80211_sched_scan_results(wiphy);
 281         /* ignore if we're not scanning */
 282
 283         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
 284                 queue_work(cfg80211_wq,
 285                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
 286 }
 287 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 288
 289 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
 290 {
 291         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 292
 293         ASSERT_RTNL();
 294
 295         trace_cfg80211_sched_scan_stopped(wiphy);
 296
 297         __cfg80211_stop_sched_scan(rdev, true);
 298 }
 299 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 300
 301 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 302 {
 303         rtnl_lock();
 304         cfg80211_sched_scan_stopped_rtnl(wiphy);
 305         rtnl_unlock();
 306 }
 307 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 308
 309 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 310                                bool driver_initiated)
 311 {
 312         struct cfg80211_sched_scan_request *sched_scan_req;
 313         struct net_device *dev;
 314
 315         ASSERT_RTNL();
 316
 317         if (!rdev->sched_scan_req)
 318                 return -ENOENT;
 319
 320         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
 321         dev = sched_scan_req->dev;
 322
 323         if (!driver_initiated) {
 324                 int err = rdev_sched_scan_stop(rdev, dev);
 325                 if (err)
 326                         return err;
 327         }
 328
 329         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 330
 331         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
 332         kfree_rcu(sched_scan_req, rcu_head);
 333
 334         return 0;
 335 }
 336
 337 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 338                       unsigned long age_secs)
 339 {
 340         struct cfg80211_internal_bss *bss;
 341         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 342
 343         spin_lock_bh(&rdev->bss_lock);
 344         list_for_each_entry(bss, &rdev->bss_list, list)
 345                 bss->ts -= age_jiffies;
 346         spin_unlock_bh(&rdev->bss_lock);
 347 }
 348
 349 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 350 {
 351         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 352 }
 353
 354 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 355 {
 356         while (len > 2 && ies[0] != eid) {
 357                 len -= ies[1] + 2;
 358                 ies += ies[1] + 2;
 359         }
 360         if (len < 2)
 361                 return NULL;
 362         if (len < 2 + ies[1])
 363                 return NULL;
 364         return ies;
 365 }
 366 EXPORT_SYMBOL(cfg80211_find_ie);
 367
 368 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 369                                   const u8 *ies, int len)
 370 {
 371         struct ieee80211_vendor_ie *ie;
 372         const u8 *pos = ies, *end = ies + len;
 373         int ie_oui;
 374
 375         while (pos < end) {
 376                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 377                                        end - pos);
 378                 if (!pos)
 379                         return NULL;
 380
 381                 ie = (struct ieee80211_vendor_ie *)pos;
 382
 383                 /* make sure we can access ie->len */
 384                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 385
 386                 if (ie->len < sizeof(*ie))
 387                         goto cont;
 388
 389                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 390                 if (ie_oui == oui && ie->oui_type == oui_type)
 391                         return pos;
 392 cont:
 393                 pos += 2 + ie->len;
 394         }
 395         return NULL;
 396 }
 397 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 398
 399 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 400                    const u8 *ssid, size_t ssid_len)
 401 {
 402         const struct cfg80211_bss_ies *ies;
 403         const u8 *ssidie;
 404
 405         if (bssid && !ether_addr_equal(a->bssid, bssid))
 406                 return false;
 407
 408         if (!ssid)
 409                 return true;
 410
 411         ies = rcu_access_pointer(a->ies);
 412         if (!ies)
 413                 return false;
 414         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 415         if (!ssidie)
 416                 return false;
 417         if (ssidie[1] != ssid_len)
 418                 return false;
 419         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 420 }
 421
 422 /**
 423  * enum bss_compare_mode - BSS compare mode
 424  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 425  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 426  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 427  */
 428 enum bss_compare_mode {
 429         BSS_CMP_REGULAR,
 430         BSS_CMP_HIDE_ZLEN,
 431         BSS_CMP_HIDE_NUL,
 432 };
 433
 434 static int cmp_bss(struct cfg80211_bss *a,
 435                    struct cfg80211_bss *b,
 436                    enum bss_compare_mode mode)
 437 {
 438         const struct cfg80211_bss_ies *a_ies, *b_ies;
 439         const u8 *ie1 = NULL;
 440         const u8 *ie2 = NULL;
 441         int i, r;
 442
 443         if (a->channel != b->channel)
 444                 return b->channel->center_freq - a->channel->center_freq;
 445
 446         a_ies = rcu_access_pointer(a->ies);
 447         if (!a_ies)
 448                 return -1;
 449         b_ies = rcu_access_pointer(b->ies);
 450         if (!b_ies)
 451                 return 1;
 452
 453         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 454                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 455                                        a_ies->data, a_ies->len);
 456         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 457                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 458                                        b_ies->data, b_ies->len);
 459         if (ie1 && ie2) {
 460                 int mesh_id_cmp;
 461
 462                 if (ie1[1] == ie2[1])
 463                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 464                 else
 465                         mesh_id_cmp = ie2[1] - ie1[1];
 466
 467                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 468                                        a_ies->data, a_ies->len);
 469                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 470                                        b_ies->data, b_ies->len);
 471                 if (ie1 && ie2) {
 472                         if (mesh_id_cmp)
 473                                 return mesh_id_cmp;
 474                         if (ie1[1] != ie2[1])
 475                                 return ie2[1] - ie1[1];
 476                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 477                 }
 478         }
 479
 480         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 481         if (r)
 482                 return r;
 483
 484         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 485         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 486
 487         if (!ie1 && !ie2)
 488                 return 0;
 489
 490         /*
 491          * Note that with "hide_ssid", the function returns a match if
 492          * the already-present BSS ("b") is a hidden SSID beacon for
 493          * the new BSS ("a").
 494          */
 495
 496         /* sort missing IE before (left of) present IE */
 497         if (!ie1)
 498                 return -1;
 499         if (!ie2)
 500                 return 1;
 501
 502         switch (mode) {
 503         case BSS_CMP_HIDE_ZLEN:
 504                 /*
 505                  * In ZLEN mode we assume the BSS entry we're
 506                  * looking for has a zero-length SSID. So if
 507                  * the one we're looking at right now has that,
 508                  * return 0. Otherwise, return the difference
 509                  * in length, but since we're looking for the
 510                  * 0-length it's really equivalent to returning
 511                  * the length of the one we're looking at.
 512                  *
 513                  * No content comparison is needed as we assume
 514                  * the content length is zero.
 515                  */
 516                 return ie2[1];
 517         case BSS_CMP_REGULAR:
 518         default:
 519                 /* sort by length first, then by contents */
 520                 if (ie1[1] != ie2[1])
 521                         return ie2[1] - ie1[1];
 522                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 523         case BSS_CMP_HIDE_NUL:
 524                 if (ie1[1] != ie2[1])
 525                         return ie2[1] - ie1[1];
 526                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 527                 for (i = 0; i < ie2[1]; i++)
 528                         if (ie2[i + 2])
 529                                 return -1;
 530                 return 0;
 531         }
 532 }
 533
 534 static bool cfg80211_bss_type_match(u16 capability,
 535                                     enum ieee80211_band band,
 536                                     enum ieee80211_bss_type bss_type)
 537 {
 538         bool ret = true;
 539         u16 mask, val;
 540
 541         if (bss_type == IEEE80211_BSS_TYPE_ANY)
 542                 return ret;
 543
 544         if (band == IEEE80211_BAND_60GHZ) {
 545                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
 546                 switch (bss_type) {
 547                 case IEEE80211_BSS_TYPE_ESS:
 548                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
 549                         break;
 550                 case IEEE80211_BSS_TYPE_PBSS:
 551                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
 552                         break;
 553                 case IEEE80211_BSS_TYPE_IBSS:
 554                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
 555                         break;
 556                 default:
 557                         return false;
 558                 }
 559         } else {
 560                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
 561                 switch (bss_type) {
 562                 case IEEE80211_BSS_TYPE_ESS:
 563                         val = WLAN_CAPABILITY_ESS;
 564                         break;
 565                 case IEEE80211_BSS_TYPE_IBSS:
 566                         val = WLAN_CAPABILITY_IBSS;
 567                         break;
 568                 case IEEE80211_BSS_TYPE_MBSS:
 569                         val = 0;
 570                         break;
 571                 default:
 572                         return false;
 573                 }
 574         }
 575
 576         ret = ((capability & mask) == val);
 577         return ret;
 578 }
 579
 580 /* Returned bss is reference counted and must be cleaned up appropriately. */
 581 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 582                                       struct ieee80211_channel *channel,
 583                                       const u8 *bssid,
 584                                       const u8 *ssid, size_t ssid_len,
 585                                       enum ieee80211_bss_type bss_type,
 586                                       enum ieee80211_privacy privacy)
 587 {
 588         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 589         struct cfg80211_internal_bss *bss, *res = NULL;
 590         unsigned long now = jiffies;
 591         int bss_privacy;
 592
 593         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
 594                                privacy);
 595
 596         spin_lock_bh(&rdev->bss_lock);
 597
 598         list_for_each_entry(bss, &rdev->bss_list, list) {
 599                 if (!cfg80211_bss_type_match(bss->pub.capability,
 600                                              bss->pub.channel->band, bss_type))
 601                         continue;
 602
 603                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
 604                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
 605                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
 606                         continue;
 607                 if (channel && bss->pub.channel != channel)
 608                         continue;
 609                 if (!is_valid_ether_addr(bss->pub.bssid))
 610                         continue;
 611                 /* Don't get expired BSS structs */
 612                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 613                     !atomic_read(&bss->hold))
 614                         continue;
 615                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 616                         res = bss;
 617                         bss_ref_get(rdev, res);
 618                         break;
 619                 }
 620         }
 621
 622         spin_unlock_bh(&rdev->bss_lock);
 623         if (!res)
 624                 return NULL;
 625         trace_cfg80211_return_bss(&res->pub);
 626         return &res->pub;
 627 }
 628 EXPORT_SYMBOL(cfg80211_get_bss);
 629
 630 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 631                           struct cfg80211_internal_bss *bss)
 632 {
 633         struct rb_node **p = &rdev->bss_tree.rb_node;
 634         struct rb_node *parent = NULL;
 635         struct cfg80211_internal_bss *tbss;
 636         int cmp;
 637
 638         while (*p) {
 639                 parent = *p;
 640                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 641
 642                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 643
 644                 if (WARN_ON(!cmp)) {
 645                         /* will sort of leak this BSS */
 646                         return;
 647                 }
 648
 649                 if (cmp < 0)
 650                         p = &(*p)->rb_left;
 651                 else
 652                         p = &(*p)->rb_right;
 653         }
 654
 655         rb_link_node(&bss->rbn, parent, p);
 656         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 657 }
 658
 659 static struct cfg80211_internal_bss *
 660 rb_find_bss(struct cfg80211_registered_device *rdev,
 661             struct cfg80211_internal_bss *res,
 662             enum bss_compare_mode mode)
 663 {
 664         struct rb_node *n = rdev->bss_tree.rb_node;
 665         struct cfg80211_internal_bss *bss;
 666         int r;
 667
 668         while (n) {
 669                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 670                 r = cmp_bss(&res->pub, &bss->pub, mode);
 671
 672                 if (r == 0)
 673                         return bss;
 674                 else if (r < 0)
 675                         n = n->rb_left;
 676                 else
 677                         n = n->rb_right;
 678         }
 679
 680         return NULL;
 681 }
 682
 683 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 684                                    struct cfg80211_internal_bss *new)
 685 {
 686         const struct cfg80211_bss_ies *ies;
 687         struct cfg80211_internal_bss *bss;
 688         const u8 *ie;
 689         int i, ssidlen;
 690         u8 fold = 0;
 691
 692         ies = rcu_access_pointer(new->pub.beacon_ies);
 693         if (WARN_ON(!ies))
 694                 return false;
 695
 696         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 697         if (!ie) {
 698                 /* nothing to do */
 699                 return true;
 700         }
 701
 702         ssidlen = ie[1];
 703         for (i = 0; i < ssidlen; i++)
 704                 fold |= ie[2 + i];
 705
 706         if (fold) {
 707                 /* not a hidden SSID */
 708                 return true;
 709         }
 710
 711         /* This is the bad part ... */
 712
 713         list_for_each_entry(bss, &rdev->bss_list, list) {
 714                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 715                         continue;
 716                 if (bss->pub.channel != new->pub.channel)
 717                         continue;
 718                 if (bss->pub.scan_width != new->pub.scan_width)
 719                         continue;
 720                 if (rcu_access_pointer(bss->pub.beacon_ies))
 721                         continue;
 722                 ies = rcu_access_pointer(bss->pub.ies);
 723                 if (!ies)
 724                         continue;
 725                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 726                 if (!ie)
 727                         continue;
 728                 if (ssidlen && ie[1] != ssidlen)
 729                         continue;
 730                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 731                         continue;
 732                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 733                         list_del(&bss->hidden_list);
 734                 /* combine them */
 735                 list_add(&bss->hidden_list, &new->hidden_list);
 736                 bss->pub.hidden_beacon_bss = &new->pub;
 737                 new->refcount += bss->refcount;
 738                 rcu_assign_pointer(bss->pub.beacon_ies,
 739                                    new->pub.beacon_ies);
 740         }
 741
 742         return true;
 743 }
 744
 745 /* Returned bss is reference counted and must be cleaned up appropriately. */
 746 static struct cfg80211_internal_bss *
 747 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 748                     struct cfg80211_internal_bss *tmp,
 749                     bool signal_valid)
 750 {
 751         struct cfg80211_internal_bss *found = NULL;
 752
 753         if (WARN_ON(!tmp->pub.channel))
 754                 return NULL;
 755
 756         tmp->ts = jiffies;
 757
 758         spin_lock_bh(&rdev->bss_lock);
 759
 760         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 761                 spin_unlock_bh(&rdev->bss_lock);
 762                 return NULL;
 763         }
 764
 765         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 766
 767         if (found) {
 768                 /* Update IEs */
 769                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 770                         const struct cfg80211_bss_ies *old;
 771
 772                         old = rcu_access_pointer(found->pub.proberesp_ies);
 773
 774                         rcu_assign_pointer(found->pub.proberesp_ies,
 775                                            tmp->pub.proberesp_ies);
 776                         /* Override possible earlier Beacon frame IEs */
 777                         rcu_assign_pointer(found->pub.ies,
 778                                            tmp->pub.proberesp_ies);
 779                         if (old)
 780                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 781                                           rcu_head);
 782                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 783                         const struct cfg80211_bss_ies *old;
 784                         struct cfg80211_internal_bss *bss;
 785
 786                         if (found->pub.hidden_beacon_bss &&
 787                             !list_empty(&found->hidden_list)) {
 788                                 const struct cfg80211_bss_ies *f;
 789
 790                                 /*
 791                                  * The found BSS struct is one of the probe
 792                                  * response members of a group, but we're
 793                                  * receiving a beacon (beacon_ies in the tmp
 794                                  * bss is used). This can only mean that the
 795                                  * AP changed its beacon from not having an
 796                                  * SSID to showing it, which is confusing so
 797                                  * drop this information.
 798                                  */
 799
 800                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 801                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 802                                           rcu_head);
 803                                 goto drop;
 804                         }
 805
 806                         old = rcu_access_pointer(found->pub.beacon_ies);
 807
 808                         rcu_assign_pointer(found->pub.beacon_ies,
 809                                            tmp->pub.beacon_ies);
 810
 811                         /* Override IEs if they were from a beacon before */
 812                         if (old == rcu_access_pointer(found->pub.ies))
 813                                 rcu_assign_pointer(found->pub.ies,
 814                                                    tmp->pub.beacon_ies);
 815
 816                         /* Assign beacon IEs to all sub entries */
 817                         list_for_each_entry(bss, &found->hidden_list,
 818                                             hidden_list) {
 819                                 const struct cfg80211_bss_ies *ies;
 820
 821                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 822                                 WARN_ON(ies != old);
 823
 824                                 rcu_assign_pointer(bss->pub.beacon_ies,
 825                                                    tmp->pub.beacon_ies);
 826                         }
 827
 828                         if (old)
 829                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 830                                           rcu_head);
 831                 }
 832
 833                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 834                 /*
 835                  * don't update the signal if beacon was heard on
 836                  * adjacent channel.
 837                  */
 838                 if (signal_valid)
 839                         found->pub.signal = tmp->pub.signal;
 840                 found->pub.capability = tmp->pub.capability;
 841                 found->ts = tmp->ts;
 842         } else {
 843                 struct cfg80211_internal_bss *new;
 844                 struct cfg80211_internal_bss *hidden;
 845                 struct cfg80211_bss_ies *ies;
 846
 847                 /*
 848                  * create a copy -- the "res" variable that is passed in
 849                  * is allocated on the stack since it's not needed in the
 850                  * more common case of an update
 851                  */
 852                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 853                               GFP_ATOMIC);
 854                 if (!new) {
 855                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 856                         if (ies)
 857                                 kfree_rcu(ies, rcu_head);
 858                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 859                         if (ies)
 860                                 kfree_rcu(ies, rcu_head);
 861                         goto drop;
 862                 }
 863                 memcpy(new, tmp, sizeof(*new));
 864                 new->refcount = 1;
 865                 INIT_LIST_HEAD(&new->hidden_list);
 866
 867                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 868                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 869                         if (!hidden)
 870                                 hidden = rb_find_bss(rdev, tmp,
 871                                                      BSS_CMP_HIDE_NUL);
 872                         if (hidden) {
 873                                 new->pub.hidden_beacon_bss = &hidden->pub;
 874                                 list_add(&new->hidden_list,
 875                                          &hidden->hidden_list);
 876                                 hidden->refcount++;
 877                                 rcu_assign_pointer(new->pub.beacon_ies,
 878                                                    hidden->pub.beacon_ies);
 879                         }
 880                 } else {
 881                         /*
 882                          * Ok so we found a beacon, and don't have an entry. If
 883                          * it's a beacon with hidden SSID, we might be in for an
 884                          * expensive search for any probe responses that should
 885                          * be grouped with this beacon for updates ...
 886                          */
 887                         if (!cfg80211_combine_bsses(rdev, new)) {
 888                                 kfree(new);
 889                                 goto drop;
 890                         }
 891                 }
 892
 893                 list_add_tail(&new->list, &rdev->bss_list);
 894                 rb_insert_bss(rdev, new);
 895                 found = new;
 896         }
 897
 898         rdev->bss_generation++;
 899         bss_ref_get(rdev, found);
 900         spin_unlock_bh(&rdev->bss_lock);
 901
 902         return found;
 903  drop:
 904         spin_unlock_bh(&rdev->bss_lock);
 905         return NULL;
 906 }
 907
 908 static struct ieee80211_channel *
 909 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 910                          struct ieee80211_channel *channel)
 911 {
 912         const u8 *tmp;
 913         u32 freq;
 914         int channel_number = -1;
 915
 916         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 917         if (tmp && tmp[1] == 1) {
 918                 channel_number = tmp[2];
 919         } else {
 920                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 921                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 922                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 923
 924                         channel_number = htop->primary_chan;
 925                 }
 926         }
 927
 928         if (channel_number < 0)
 929                 return channel;
 930
 931         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 932         channel = ieee80211_get_channel(wiphy, freq);
 933         if (!channel)
 934                 return NULL;
 935         if (channel->flags & IEEE80211_CHAN_DISABLED)
 936                 return NULL;
 937         return channel;
 938 }
 939
 940 /* Returned bss is reference counted and must be cleaned up appropriately. */
 941 struct cfg80211_bss*
 942 cfg80211_inform_bss_width(struct wiphy *wiphy,
 943                           struct ieee80211_channel *rx_channel,
 944                           enum nl80211_bss_scan_width scan_width,
 945                           enum cfg80211_bss_frame_type ftype,
 946                           const u8 *bssid, u64 tsf, u16 capability,
 947                           u16 beacon_interval, const u8 *ie, size_t ielen,
 948                           s32 signal, gfp_t gfp)
 949 {
 950         struct cfg80211_bss_ies *ies;
 951         struct ieee80211_channel *channel;
 952         struct cfg80211_internal_bss tmp = {}, *res;
 953         int bss_type;
 954         bool signal_valid;
 955
 956         if (WARN_ON(!wiphy))
 957                 return NULL;
 958
 959         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 960                         (signal < 0 || signal > 100)))
 961                 return NULL;
 962
 963         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 964         if (!channel)
 965                 return NULL;
 966
 967         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 968         tmp.pub.channel = channel;
 969         tmp.pub.scan_width = scan_width;
 970         tmp.pub.signal = signal;
 971         tmp.pub.beacon_interval = beacon_interval;
 972         tmp.pub.capability = capability;
 973         /*
 974          * If we do not know here whether the IEs are from a Beacon or Probe
 975          * Response frame, we need to pick one of the options and only use it
 976          * with the driver that does not provide the full Beacon/Probe Response
 977          * frame. Use Beacon frame pointer to avoid indicating that this should
 978          * override the IEs pointer should we have received an earlier
 979          * indication of Probe Response data.
 980          */
 981         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 982         if (!ies)
 983                 return NULL;
 984         ies->len = ielen;
 985         ies->tsf = tsf;
 986         ies->from_beacon = false;
 987         memcpy(ies->data, ie, ielen);
 988
 989         switch (ftype) {
 990         case CFG80211_BSS_FTYPE_BEACON:
 991                 ies->from_beacon = true;
 992                 /* fall through to assign */
 993         case CFG80211_BSS_FTYPE_UNKNOWN:
 994                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 995                 break;
 996         case CFG80211_BSS_FTYPE_PRESP:
 997                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 998                 break;
 999         }
1000         rcu_assign_pointer(tmp.pub.ies, ies);
1001
1002         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
1003                 wiphy->max_adj_channel_rssi_comp;
1004         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1005         if (!res)
1006                 return NULL;
1007
1008         if (channel->band == IEEE80211_BAND_60GHZ) {
1009                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1010                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1011                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1012                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1013         } else {
1014                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1015                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1016         }
1017
1018         trace_cfg80211_return_bss(&res->pub);
1019         /* cfg80211_bss_update gives us a referenced result */
1020         return &res->pub;
1021 }
1022 EXPORT_SYMBOL(cfg80211_inform_bss_width);
1023
1024 /* Returned bss is reference counted and must be cleaned up appropriately. */
1025 struct cfg80211_bss *
1026 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
1027                                 struct ieee80211_channel *rx_channel,
1028                                 enum nl80211_bss_scan_width scan_width,
1029                                 struct ieee80211_mgmt *mgmt, size_t len,
1030                                 s32 signal, gfp_t gfp)
1031 {
1032         struct cfg80211_internal_bss tmp = {}, *res;
1033         struct cfg80211_bss_ies *ies;
1034         struct ieee80211_channel *channel;
1035         bool signal_valid;
1036         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1037                                       u.probe_resp.variable);
1038         int bss_type;
1039
1040         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1041                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1042
1043         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
1044                                               len, signal);
1045
1046         if (WARN_ON(!mgmt))
1047                 return NULL;
1048
1049         if (WARN_ON(!wiphy))
1050                 return NULL;
1051
1052         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1053                     (signal < 0 || signal > 100)))
1054                 return NULL;
1055
1056         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1057                 return NULL;
1058
1059         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1060                                            ielen, rx_channel);
1061         if (!channel)
1062                 return NULL;
1063
1064         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1065         if (!ies)
1066                 return NULL;
1067         ies->len = ielen;
1068         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1069         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1070         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1071
1072         if (ieee80211_is_probe_resp(mgmt->frame_control))
1073                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1074         else
1075                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1076         rcu_assign_pointer(tmp.pub.ies, ies);
1077
1078         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1079         tmp.pub.channel = channel;
1080         tmp.pub.scan_width = scan_width;
1081         tmp.pub.signal = signal;
1082         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1083         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1084
1085         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
1086                 wiphy->max_adj_channel_rssi_comp;
1087         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1088         if (!res)
1089                 return NULL;
1090
1091         if (channel->band == IEEE80211_BAND_60GHZ) {
1092                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1093                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1094                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1095                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1096         } else {
1097                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1098                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1099         }
1100
1101         trace_cfg80211_return_bss(&res->pub);
1102         /* cfg80211_bss_update gives us a referenced result */
1103         return &res->pub;
1104 }
1105 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1106
1107 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1108 {
1109         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1110         struct cfg80211_internal_bss *bss;
1111
1112         if (!pub)
1113                 return;
1114
1115         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1116
1117         spin_lock_bh(&rdev->bss_lock);
1118         bss_ref_get(rdev, bss);
1119         spin_unlock_bh(&rdev->bss_lock);
1120 }
1121 EXPORT_SYMBOL(cfg80211_ref_bss);
1122
1123 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1124 {
1125         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1126         struct cfg80211_internal_bss *bss;
1127
1128         if (!pub)
1129                 return;
1130
1131         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1132
1133         spin_lock_bh(&rdev->bss_lock);
1134         bss_ref_put(rdev, bss);
1135         spin_unlock_bh(&rdev->bss_lock);
1136 }
1137 EXPORT_SYMBOL(cfg80211_put_bss);
1138
1139 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1140 {
1141         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1142         struct cfg80211_internal_bss *bss;
1143
1144         if (WARN_ON(!pub))
1145                 return;
1146
1147         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1148
1149         spin_lock_bh(&rdev->bss_lock);
1150         if (!list_empty(&bss->list)) {
1151                 if (__cfg80211_unlink_bss(rdev, bss))
1152                         rdev->bss_generation++;
1153         }
1154         spin_unlock_bh(&rdev->bss_lock);
1155 }
1156 EXPORT_SYMBOL(cfg80211_unlink_bss);
1157
1158 #ifdef CONFIG_CFG80211_WEXT
1159 static struct cfg80211_registered_device *
1160 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1161 {
1162         struct cfg80211_registered_device *rdev;
1163         struct net_device *dev;
1164
1165         ASSERT_RTNL();
1166
1167         dev = dev_get_by_index(net, ifindex);
1168         if (!dev)
1169                 return ERR_PTR(-ENODEV);
1170         if (dev->ieee80211_ptr)
1171                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1172         else
1173                 rdev = ERR_PTR(-ENODEV);
1174         dev_put(dev);
1175         return rdev;
1176 }
1177
1178 int cfg80211_wext_siwscan(struct net_device *dev,
1179                           struct iw_request_info *info,
1180                           union iwreq_data *wrqu, char *extra)
1181 {
1182         struct cfg80211_registered_device *rdev;
1183         struct wiphy *wiphy;
1184         struct iw_scan_req *wreq = NULL;
1185         struct cfg80211_scan_request *creq = NULL;
1186         int i, err, n_channels = 0;
1187         enum ieee80211_band band;
1188
1189         if (!netif_running(dev))
1190                 return -ENETDOWN;
1191
1192         if (wrqu->data.length == sizeof(struct iw_scan_req))
1193                 wreq = (struct iw_scan_req *)extra;
1194
1195         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1196
1197         if (IS_ERR(rdev))
1198                 return PTR_ERR(rdev);
1199
1200         if (rdev->scan_req || rdev->scan_msg) {
1201                 err = -EBUSY;
1202                 goto out;
1203         }
1204
1205         wiphy = &rdev->wiphy;
1206
1207         /* Determine number of channels, needed to allocate creq */
1208         if (wreq && wreq->num_channels)
1209                 n_channels = wreq->num_channels;
1210         else
1211                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1212
1213         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1214                        n_channels * sizeof(void *),
1215                        GFP_ATOMIC);
1216         if (!creq) {
1217                 err = -ENOMEM;
1218                 goto out;
1219         }
1220
1221         creq->wiphy = wiphy;
1222         creq->wdev = dev->ieee80211_ptr;
1223         /* SSIDs come after channels */
1224         creq->ssids = (void *)&creq->channels[n_channels];
1225         creq->n_channels = n_channels;
1226         creq->n_ssids = 1;
1227         creq->scan_start = jiffies;
1228
1229         /* translate "Scan on frequencies" request */
1230         i = 0;
1231         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1232                 int j;
1233
1234                 if (!wiphy->bands[band])
1235                         continue;
1236
1237                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1238                         /* ignore disabled channels */
1239                         if (wiphy->bands[band]->channels[j].flags &
1240                                                 IEEE80211_CHAN_DISABLED)
1241                                 continue;
1242
1243                         /* If we have a wireless request structure and the
1244                          * wireless request specifies frequencies, then search
1245                          * for the matching hardware channel.
1246                          */
1247                         if (wreq && wreq->num_channels) {
1248                                 int k;
1249                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1250                                 for (k = 0; k < wreq->num_channels; k++) {
1251                                         struct iw_freq *freq =
1252                                                 &wreq->channel_list[k];
1253                                         int wext_freq =
1254                                                 cfg80211_wext_freq(freq);
1255
1256                                         if (wext_freq == wiphy_freq)
1257                                                 goto wext_freq_found;
1258                                 }
1259                                 goto wext_freq_not_found;
1260                         }
1261
1262                 wext_freq_found:
1263                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1264                         i++;
1265                 wext_freq_not_found: ;
1266                 }
1267         }
1268         /* No channels found? */
1269         if (!i) {
1270                 err = -EINVAL;
1271                 goto out;
1272         }
1273
1274         /* Set real number of channels specified in creq->channels[] */
1275         creq->n_channels = i;
1276
1277         /* translate "Scan for SSID" request */
1278         if (wreq) {
1279                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1280                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1281                                 err = -EINVAL;
1282                                 goto out;
1283                         }
1284                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1285                         creq->ssids[0].ssid_len = wreq->essid_len;
1286                 }
1287                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1288                         creq->n_ssids = 0;
1289         }
1290
1291         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1292                 if (wiphy->bands[i])
1293                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1294
1295         rdev->scan_req = creq;
1296         err = rdev_scan(rdev, creq);
1297         if (err) {
1298                 rdev->scan_req = NULL;
1299                 /* creq will be freed below */
1300         } else {
1301                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1302                 /* creq now owned by driver */
1303                 creq = NULL;
1304                 dev_hold(dev);
1305         }
1306  out:
1307         kfree(creq);
1308         return err;
1309 }
1310 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1311
1312 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1313                                     const struct cfg80211_bss_ies *ies,
1314                                     char *current_ev, char *end_buf)
1315 {
1316         const u8 *pos, *end, *next;
1317         struct iw_event iwe;
1318
1319         if (!ies)
1320                 return current_ev;
1321
1322         /*
1323          * If needed, fragment the IEs buffer (at IE boundaries) into short
1324          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1325          */
1326         pos = ies->data;
1327         end = pos + ies->len;
1328
1329         while (end - pos > IW_GENERIC_IE_MAX) {
1330                 next = pos + 2 + pos[1];
1331                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1332                         next = next + 2 + next[1];
1333
1334                 memset(&iwe, 0, sizeof(iwe));
1335                 iwe.cmd = IWEVGENIE;
1336                 iwe.u.data.length = next - pos;
1337                 current_ev = iwe_stream_add_point_check(info, current_ev,
1338                                                         end_buf, &iwe,
1339                                                         (void *)pos);
1340                 if (IS_ERR(current_ev))
1341                         return current_ev;
1342                 pos = next;
1343         }
1344
1345         if (end > pos) {
1346                 memset(&iwe, 0, sizeof(iwe));
1347                 iwe.cmd = IWEVGENIE;
1348                 iwe.u.data.length = end - pos;
1349                 current_ev = iwe_stream_add_point_check(info, current_ev,
1350                                                         end_buf, &iwe,
1351                                                         (void *)pos);
1352                 if (IS_ERR(current_ev))
1353                         return current_ev;
1354         }
1355
1356         return current_ev;
1357 }
1358
1359 static char *
1360 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1361               struct cfg80211_internal_bss *bss, char *current_ev,
1362               char *end_buf)
1363 {
1364         const struct cfg80211_bss_ies *ies;
1365         struct iw_event iwe;
1366         const u8 *ie;
1367         u8 buf[50];
1368         u8 *cfg, *p, *tmp;
1369         int rem, i, sig;
1370         bool ismesh = false;
1371
1372         memset(&iwe, 0, sizeof(iwe));
1373         iwe.cmd = SIOCGIWAP;
1374         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1375         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1376         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1377                                                 IW_EV_ADDR_LEN);
1378         if (IS_ERR(current_ev))
1379                 return current_ev;
1380
1381         memset(&iwe, 0, sizeof(iwe));
1382         iwe.cmd = SIOCGIWFREQ;
1383         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1384         iwe.u.freq.e = 0;
1385         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1386                                                 IW_EV_FREQ_LEN);
1387         if (IS_ERR(current_ev))
1388                 return current_ev;
1389
1390         memset(&iwe, 0, sizeof(iwe));
1391         iwe.cmd = SIOCGIWFREQ;
1392         iwe.u.freq.m = bss->pub.channel->center_freq;
1393         iwe.u.freq.e = 6;
1394         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1395                                                 IW_EV_FREQ_LEN);
1396         if (IS_ERR(current_ev))
1397                 return current_ev;
1398
1399         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1400                 memset(&iwe, 0, sizeof(iwe));
1401                 iwe.cmd = IWEVQUAL;
1402                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1403                                      IW_QUAL_NOISE_INVALID |
1404                                      IW_QUAL_QUAL_UPDATED;
1405                 switch (wiphy->signal_type) {
1406                 case CFG80211_SIGNAL_TYPE_MBM:
1407                         sig = bss->pub.signal / 100;
1408                         iwe.u.qual.level = sig;
1409                         iwe.u.qual.updated |= IW_QUAL_DBM;
1410                         if (sig < -110)         /* rather bad */
1411                                 sig = -110;
1412                         else if (sig > -40)     /* perfect */
1413                                 sig = -40;
1414                         /* will give a range of 0 .. 70 */
1415                         iwe.u.qual.qual = sig + 110;
1416                         break;
1417                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1418                         iwe.u.qual.level = bss->pub.signal;
1419                         /* will give range 0 .. 100 */
1420                         iwe.u.qual.qual = bss->pub.signal;
1421                         break;
1422                 default:
1423                         /* not reached */
1424                         break;
1425                 }
1426                 current_ev = iwe_stream_add_event_check(info, current_ev,
1427                                                         end_buf, &iwe,
1428                                                         IW_EV_QUAL_LEN);
1429                 if (IS_ERR(current_ev))
1430                         return current_ev;
1431         }
1432
1433         memset(&iwe, 0, sizeof(iwe));
1434         iwe.cmd = SIOCGIWENCODE;
1435         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1436                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1437         else
1438                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1439         iwe.u.data.length = 0;
1440         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1441                                                 &iwe, "");
1442         if (IS_ERR(current_ev))
1443                 return current_ev;
1444
1445         rcu_read_lock();
1446         ies = rcu_dereference(bss->pub.ies);
1447         rem = ies->len;
1448         ie = ies->data;
1449
1450         while (rem >= 2) {
1451                 /* invalid data */
1452                 if (ie[1] > rem - 2)
1453                         break;
1454
1455                 switch (ie[0]) {
1456                 case WLAN_EID_SSID:
1457                         memset(&iwe, 0, sizeof(iwe));
1458                         iwe.cmd = SIOCGIWESSID;
1459                         iwe.u.data.length = ie[1];
1460                         iwe.u.data.flags = 1;
1461                         current_ev = iwe_stream_add_point_check(info,
1462                                                                 current_ev,
1463                                                                 end_buf, &iwe,
1464                                                                 (u8 *)ie + 2);
1465                         if (IS_ERR(current_ev))
1466                                 goto unlock;
1467                         break;
1468                 case WLAN_EID_MESH_ID:
1469                         memset(&iwe, 0, sizeof(iwe));
1470                         iwe.cmd = SIOCGIWESSID;
1471                         iwe.u.data.length = ie[1];
1472                         iwe.u.data.flags = 1;
1473                         current_ev = iwe_stream_add_point_check(info,
1474                                                                 current_ev,
1475                                                                 end_buf, &iwe,
1476                                                                 (u8 *)ie + 2);
1477                         if (IS_ERR(current_ev))
1478                                 goto unlock;
1479                         break;
1480                 case WLAN_EID_MESH_CONFIG:
1481                         ismesh = true;
1482                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1483                                 break;
1484                         cfg = (u8 *)ie + 2;
1485                         memset(&iwe, 0, sizeof(iwe));
1486                         iwe.cmd = IWEVCUSTOM;
1487                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1488                                 "0x%02X", cfg[0]);
1489                         iwe.u.data.length = strlen(buf);
1490                         current_ev = iwe_stream_add_point_check(info,
1491                                                                 current_ev,
1492                                                                 end_buf,
1493                                                                 &iwe, buf);
1494                         if (IS_ERR(current_ev))
1495                                 goto unlock;
1496                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1497                                 cfg[1]);
1498                         iwe.u.data.length = strlen(buf);
1499                         current_ev = iwe_stream_add_point_check(info,
1500                                                                 current_ev,
1501                                                                 end_buf,
1502                                                                 &iwe, buf);
1503                         if (IS_ERR(current_ev))
1504                                 goto unlock;
1505                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1506                                 cfg[2]);
1507                         iwe.u.data.length = strlen(buf);
1508                         current_ev = iwe_stream_add_point_check(info,
1509                                                                 current_ev,
1510                                                                 end_buf,
1511                                                                 &iwe, buf);
1512                         if (IS_ERR(current_ev))
1513                                 goto unlock;
1514                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1515                         iwe.u.data.length = strlen(buf);
1516                         current_ev = iwe_stream_add_point_check(info,
1517                                                                 current_ev,
1518                                                                 end_buf,
1519                                                                 &iwe, buf);
1520                         if (IS_ERR(current_ev))
1521                                 goto unlock;
1522                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1523                         iwe.u.data.length = strlen(buf);
1524                         current_ev = iwe_stream_add_point_check(info,
1525                                                                 current_ev,
1526                                                                 end_buf,
1527                                                                 &iwe, buf);
1528                         if (IS_ERR(current_ev))
1529                                 goto unlock;
1530                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1531                         iwe.u.data.length = strlen(buf);
1532                         current_ev = iwe_stream_add_point_check(info,
1533                                                                 current_ev,
1534                                                                 end_buf,
1535                                                                 &iwe, buf);
1536                         if (IS_ERR(current_ev))
1537                                 goto unlock;
1538                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1539                         iwe.u.data.length = strlen(buf);
1540                         current_ev = iwe_stream_add_point_check(info,
1541                                                                 current_ev,
1542                                                                 end_buf,
1543                                                                 &iwe, buf);
1544                         if (IS_ERR(current_ev))
1545                                 goto unlock;
1546                         break;
1547                 case WLAN_EID_SUPP_RATES:
1548                 case WLAN_EID_EXT_SUPP_RATES:
1549                         /* display all supported rates in readable format */
1550                         p = current_ev + iwe_stream_lcp_len(info);
1551
1552                         memset(&iwe, 0, sizeof(iwe));
1553                         iwe.cmd = SIOCGIWRATE;
1554                         /* Those two flags are ignored... */
1555                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1556
1557                         for (i = 0; i < ie[1]; i++) {
1558                                 iwe.u.bitrate.value =
1559                                         ((ie[i + 2] & 0x7f) * 500000);
1560                                 tmp = p;
1561                                 p = iwe_stream_add_value(info, current_ev, p,
1562                                                          end_buf, &iwe,
1563                                                          IW_EV_PARAM_LEN);
1564                                 if (p == tmp) {
1565                                         current_ev = ERR_PTR(-E2BIG);
1566                                         goto unlock;
1567                                 }
1568                         }
1569                         current_ev = p;
1570                         break;
1571                 }
1572                 rem -= ie[1] + 2;
1573                 ie += ie[1] + 2;
1574         }
1575
1576         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1577             ismesh) {
1578                 memset(&iwe, 0, sizeof(iwe));
1579                 iwe.cmd = SIOCGIWMODE;
1580                 if (ismesh)
1581                         iwe.u.mode = IW_MODE_MESH;
1582                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1583                         iwe.u.mode = IW_MODE_MASTER;
1584                 else
1585                         iwe.u.mode = IW_MODE_ADHOC;
1586                 current_ev = iwe_stream_add_event_check(info, current_ev,
1587                                                         end_buf, &iwe,
1588                                                         IW_EV_UINT_LEN);
1589                 if (IS_ERR(current_ev))
1590                         goto unlock;
1591         }
1592
1593         memset(&iwe, 0, sizeof(iwe));
1594         iwe.cmd = IWEVCUSTOM;
1595         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1596         iwe.u.data.length = strlen(buf);
1597         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1598                                                 &iwe, buf);
1599         if (IS_ERR(current_ev))
1600                 goto unlock;
1601         memset(&iwe, 0, sizeof(iwe));
1602         iwe.cmd = IWEVCUSTOM;
1603         sprintf(buf, " Last beacon: %ums ago",
1604                 elapsed_jiffies_msecs(bss->ts));
1605         iwe.u.data.length = strlen(buf);
1606         current_ev = iwe_stream_add_point_check(info, current_ev,
1607                                                 end_buf, &iwe, buf);
1608         if (IS_ERR(current_ev))
1609                 goto unlock;
1610
1611         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1612
1613  unlock:
1614         rcu_read_unlock();
1615         return current_ev;
1616 }
1617
1618
1619 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1620                                   struct iw_request_info *info,
1621                                   char *buf, size_t len)
1622 {
1623         char *current_ev = buf;
1624         char *end_buf = buf + len;
1625         struct cfg80211_internal_bss *bss;
1626         int err = 0;
1627
1628         spin_lock_bh(&rdev->bss_lock);
1629         cfg80211_bss_expire(rdev);
1630
1631         list_for_each_entry(bss, &rdev->bss_list, list) {
1632                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1633                         err = -E2BIG;
1634                         break;
1635                 }
1636                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1637                                            current_ev, end_buf);
1638                 if (IS_ERR(current_ev)) {
1639                         err = PTR_ERR(current_ev);
1640                         break;
1641                 }
1642         }
1643         spin_unlock_bh(&rdev->bss_lock);
1644
1645         if (err)
1646                 return err;
1647         return current_ev - buf;
1648 }
1649
1650
1651 int cfg80211_wext_giwscan(struct net_device *dev,
1652                           struct iw_request_info *info,
1653                           struct iw_point *data, char *extra)
1654 {
1655         struct cfg80211_registered_device *rdev;
1656         int res;
1657
1658         if (!netif_running(dev))
1659                 return -ENETDOWN;
1660
1661         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1662
1663         if (IS_ERR(rdev))
1664                 return PTR_ERR(rdev);
1665
1666         if (rdev->scan_req || rdev->scan_msg)
1667                 return -EAGAIN;
1668
1669         res = ieee80211_scan_results(rdev, info, extra, data->length);
1670         data->length = 0;
1671         if (res >= 0) {
1672                 data->length = res;
1673                 res = 0;
1674         }
1675
1676         return res;
1677 }
1678 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1679 #endif