net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/slab.h>
   8 #include <linux/module.h>
   9 #include <linux/netdevice.h>
  10 #include <linux/wireless.h>
  11 #include <linux/nl80211.h>
  12 #include <linux/etherdevice.h>
  13 #include <net/arp.h>
  14 #include <net/cfg80211.h>
  15 #include <net/cfg80211-wext.h>
  16 #include <net/iw_handler.h>
  17 #include "core.h"
  18 #include "nl80211.h"
  19 #include "wext-compat.h"
  20 #include "rdev-ops.h"
  21
  22 /**
  23  * DOC: BSS tree/list structure
  24  *
  25  * At the top level, the BSS list is kept in both a list in each
  26  * registered device (@bss_list) as well as an RB-tree for faster
  27  * lookup. In the RB-tree, entries can be looked up using their
  28  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  29  * for other BSSes.
  30  *
  31  * Due to the possibility of hidden SSIDs, there's a second level
  32  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  33  * The hidden_list connects all BSSes belonging to a single AP
  34  * that has a hidden SSID, and connects beacon and probe response
  35  * entries. For a probe response entry for a hidden SSID, the
  36  * hidden_beacon_bss pointer points to the BSS struct holding the
  37  * beacon's information.
  38  *
  39  * Reference counting is done for all these references except for
  40  * the hidden_list, so that a beacon BSS struct that is otherwise
  41  * not referenced has one reference for being on the bss_list and
  42  * one for each probe response entry that points to it using the
  43  * hidden_beacon_bss pointer. When a BSS struct that has such a
  44  * pointer is get/put, the refcount update is also propagated to
  45  * the referenced struct, this ensure that it cannot get removed
  46  * while somebody is using the probe response version.
  47  *
  48  * Note that the hidden_beacon_bss pointer never changes, due to
  49  * the reference counting. Therefore, no locking is needed for
  50  * it.
  51  *
  52  * Also note that the hidden_beacon_bss pointer is only relevant
  53  * if the driver uses something other than the IEs, e.g. private
  54  * data stored stored in the BSS struct, since the beacon IEs are
  55  * also linked into the probe response struct.
  56  */
  57
  58 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  59
  60 static void bss_free(struct cfg80211_internal_bss *bss)
  61 {
  62         struct cfg80211_bss_ies *ies;
  63
  64         if (WARN_ON(atomic_read(&bss->hold)))
  65                 return;
  66
  67         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  68         if (ies && !bss->pub.hidden_beacon_bss)
  69                 kfree_rcu(ies, rcu_head);
  70         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  71         if (ies)
  72                 kfree_rcu(ies, rcu_head);
  73
  74         /*
  75          * This happens when the module is removed, it doesn't
  76          * really matter any more save for completeness
  77          */
  78         if (!list_empty(&bss->hidden_list))
  79                 list_del(&bss->hidden_list);
  80
  81         kfree(bss);
  82 }
  83
  84 static inline void bss_ref_get(struct cfg80211_registered_device *dev,
  85                                struct cfg80211_internal_bss *bss)
  86 {
  87         lockdep_assert_held(&dev->bss_lock);
  88
  89         bss->refcount++;
  90         if (bss->pub.hidden_beacon_bss) {
  91                 bss = container_of(bss->pub.hidden_beacon_bss,
  92                                    struct cfg80211_internal_bss,
  93                                    pub);
  94                 bss->refcount++;
  95         }
  96 }
  97
  98 static inline void bss_ref_put(struct cfg80211_registered_device *dev,
  99                                struct cfg80211_internal_bss *bss)
 100 {
 101         lockdep_assert_held(&dev->bss_lock);
 102
 103         if (bss->pub.hidden_beacon_bss) {
 104                 struct cfg80211_internal_bss *hbss;
 105                 hbss = container_of(bss->pub.hidden_beacon_bss,
 106                                     struct cfg80211_internal_bss,
 107                                     pub);
 108                 hbss->refcount--;
 109                 if (hbss->refcount == 0)
 110                         bss_free(hbss);
 111         }
 112         bss->refcount--;
 113         if (bss->refcount == 0)
 114                 bss_free(bss);
 115 }
 116
 117 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
 118                                   struct cfg80211_internal_bss *bss)
 119 {
 120         lockdep_assert_held(&dev->bss_lock);
 121
 122         if (!list_empty(&bss->hidden_list)) {
 123                 /*
 124                  * don't remove the beacon entry if it has
 125                  * probe responses associated with it
 126                  */
 127                 if (!bss->pub.hidden_beacon_bss)
 128                         return false;
 129                 /*
 130                  * if it's a probe response entry break its
 131                  * link to the other entries in the group
 132                  */
 133                 list_del_init(&bss->hidden_list);
 134         }
 135
 136         list_del_init(&bss->list);
 137         rb_erase(&bss->rbn, &dev->bss_tree);
 138         bss_ref_put(dev, bss);
 139         return true;
 140 }
 141
 142 static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
 143                                   unsigned long expire_time)
 144 {
 145         struct cfg80211_internal_bss *bss, *tmp;
 146         bool expired = false;
 147
 148         lockdep_assert_held(&dev->bss_lock);
 149
 150         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 151                 if (atomic_read(&bss->hold))
 152                         continue;
 153                 if (!time_after(expire_time, bss->ts))
 154                         continue;
 155
 156                 if (__cfg80211_unlink_bss(dev, bss))
 157                         expired = true;
 158         }
 159
 160         if (expired)
 161                 dev->bss_generation++;
 162 }
 163
 164 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
 165 {
 166         struct cfg80211_scan_request *request;
 167         struct wireless_dev *wdev;
 168 #ifdef CONFIG_CFG80211_WEXT
 169         union iwreq_data wrqu;
 170 #endif
 171
 172         ASSERT_RTNL();
 173
 174         request = rdev->scan_req;
 175
 176         if (!request)
 177                 return;
 178
 179         wdev = request->wdev;
 180
 181         /*
 182          * This must be before sending the other events!
 183          * Otherwise, wpa_supplicant gets completely confused with
 184          * wext events.
 185          */
 186         if (wdev->netdev)
 187                 cfg80211_sme_scan_done(wdev->netdev);
 188
 189         if (request->aborted) {
 190                 nl80211_send_scan_aborted(rdev, wdev);
 191         } else {
 192                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 193                         /* flush entries from previous scans */
 194                         spin_lock_bh(&rdev->bss_lock);
 195                         __cfg80211_bss_expire(rdev, request->scan_start);
 196                         spin_unlock_bh(&rdev->bss_lock);
 197                 }
 198                 nl80211_send_scan_done(rdev, wdev);
 199         }
 200
 201 #ifdef CONFIG_CFG80211_WEXT
 202         if (wdev->netdev && !request->aborted) {
 203                 memset(&wrqu, 0, sizeof(wrqu));
 204
 205                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 206         }
 207 #endif
 208
 209         if (wdev->netdev)
 210                 dev_put(wdev->netdev);
 211
 212         rdev->scan_req = NULL;
 213
 214         /*
 215          * OK. If this is invoked with "leak" then we can't
 216          * free this ... but we've cleaned it up anyway. The
 217          * driver failed to call the scan_done callback, so
 218          * all bets are off, it might still be trying to use
 219          * the scan request or not ... if it accesses the dev
 220          * in there (it shouldn't anyway) then it may crash.
 221          */
 222         if (!leak)
 223                 kfree(request);
 224 }
 225
 226 void __cfg80211_scan_done(struct work_struct *wk)
 227 {
 228         struct cfg80211_registered_device *rdev;
 229
 230         rdev = container_of(wk, struct cfg80211_registered_device,
 231                             scan_done_wk);
 232
 233         rtnl_lock();
 234         ___cfg80211_scan_done(rdev, false);
 235         rtnl_unlock();
 236 }
 237
 238 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 239 {
 240         trace_cfg80211_scan_done(request, aborted);
 241         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
 242
 243         request->aborted = aborted;
 244         request->notified = true;
 245         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
 246 }
 247 EXPORT_SYMBOL(cfg80211_scan_done);
 248
 249 void __cfg80211_sched_scan_results(struct work_struct *wk)
 250 {
 251         struct cfg80211_registered_device *rdev;
 252         struct cfg80211_sched_scan_request *request;
 253
 254         rdev = container_of(wk, struct cfg80211_registered_device,
 255                             sched_scan_results_wk);
 256
 257         rtnl_lock();
 258
 259         request = rdev->sched_scan_req;
 260
 261         /* we don't have sched_scan_req anymore if the scan is stopping */
 262         if (request) {
 263                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 264                         /* flush entries from previous scans */
 265                         spin_lock_bh(&rdev->bss_lock);
 266                         __cfg80211_bss_expire(rdev, request->scan_start);
 267                         spin_unlock_bh(&rdev->bss_lock);
 268                         request->scan_start =
 269                                 jiffies + msecs_to_jiffies(request->interval);
 270                 }
 271                 nl80211_send_sched_scan_results(rdev, request->dev);
 272         }
 273
 274         rtnl_unlock();
 275 }
 276
 277 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 278 {
 279         trace_cfg80211_sched_scan_results(wiphy);
 280         /* ignore if we're not scanning */
 281         if (wiphy_to_dev(wiphy)->sched_scan_req)
 282                 queue_work(cfg80211_wq,
 283                            &wiphy_to_dev(wiphy)->sched_scan_results_wk);
 284 }
 285 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 286
 287 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 288 {
 289         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 290
 291         trace_cfg80211_sched_scan_stopped(wiphy);
 292
 293         rtnl_lock();
 294         __cfg80211_stop_sched_scan(rdev, true);
 295         rtnl_unlock();
 296 }
 297 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 298
 299 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 300                                bool driver_initiated)
 301 {
 302         struct net_device *dev;
 303
 304         ASSERT_RTNL();
 305
 306         if (!rdev->sched_scan_req)
 307                 return -ENOENT;
 308
 309         dev = rdev->sched_scan_req->dev;
 310
 311         if (!driver_initiated) {
 312                 int err = rdev_sched_scan_stop(rdev, dev);
 313                 if (err)
 314                         return err;
 315         }
 316
 317         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 318
 319         kfree(rdev->sched_scan_req);
 320         rdev->sched_scan_req = NULL;
 321
 322         return 0;
 323 }
 324
 325 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 326                       unsigned long age_secs)
 327 {
 328         struct cfg80211_internal_bss *bss;
 329         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 330
 331         spin_lock_bh(&dev->bss_lock);
 332         list_for_each_entry(bss, &dev->bss_list, list)
 333                 bss->ts -= age_jiffies;
 334         spin_unlock_bh(&dev->bss_lock);
 335 }
 336
 337 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 338 {
 339         __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 340 }
 341
 342 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 343 {
 344         while (len > 2 && ies[0] != eid) {
 345                 len -= ies[1] + 2;
 346                 ies += ies[1] + 2;
 347         }
 348         if (len < 2)
 349                 return NULL;
 350         if (len < 2 + ies[1])
 351                 return NULL;
 352         return ies;
 353 }
 354 EXPORT_SYMBOL(cfg80211_find_ie);
 355
 356 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 357                                   const u8 *ies, int len)
 358 {
 359         struct ieee80211_vendor_ie *ie;
 360         const u8 *pos = ies, *end = ies + len;
 361         int ie_oui;
 362
 363         while (pos < end) {
 364                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 365                                        end - pos);
 366                 if (!pos)
 367                         return NULL;
 368
 369                 ie = (struct ieee80211_vendor_ie *)pos;
 370
 371                 /* make sure we can access ie->len */
 372                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 373
 374                 if (ie->len < sizeof(*ie))
 375                         goto cont;
 376
 377                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 378                 if (ie_oui == oui && ie->oui_type == oui_type)
 379                         return pos;
 380 cont:
 381                 pos += 2 + ie->len;
 382         }
 383         return NULL;
 384 }
 385 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 386
 387 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 388                    const u8 *ssid, size_t ssid_len)
 389 {
 390         const struct cfg80211_bss_ies *ies;
 391         const u8 *ssidie;
 392
 393         if (bssid && !ether_addr_equal(a->bssid, bssid))
 394                 return false;
 395
 396         if (!ssid)
 397                 return true;
 398
 399         ies = rcu_access_pointer(a->ies);
 400         if (!ies)
 401                 return false;
 402         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 403         if (!ssidie)
 404                 return false;
 405         if (ssidie[1] != ssid_len)
 406                 return false;
 407         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 408 }
 409
 410 /**
 411  * enum bss_compare_mode - BSS compare mode
 412  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 413  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 414  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 415  */
 416 enum bss_compare_mode {
 417         BSS_CMP_REGULAR,
 418         BSS_CMP_HIDE_ZLEN,
 419         BSS_CMP_HIDE_NUL,
 420 };
 421
 422 static int cmp_bss(struct cfg80211_bss *a,
 423                    struct cfg80211_bss *b,
 424                    enum bss_compare_mode mode)
 425 {
 426         const struct cfg80211_bss_ies *a_ies, *b_ies;
 427         const u8 *ie1 = NULL;
 428         const u8 *ie2 = NULL;
 429         int i, r;
 430
 431         if (a->channel != b->channel)
 432                 return b->channel->center_freq - a->channel->center_freq;
 433
 434         a_ies = rcu_access_pointer(a->ies);
 435         if (!a_ies)
 436                 return -1;
 437         b_ies = rcu_access_pointer(b->ies);
 438         if (!b_ies)
 439                 return 1;
 440
 441         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 442                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 443                                        a_ies->data, a_ies->len);
 444         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 445                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 446                                        b_ies->data, b_ies->len);
 447         if (ie1 && ie2) {
 448                 int mesh_id_cmp;
 449
 450                 if (ie1[1] == ie2[1])
 451                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 452                 else
 453                         mesh_id_cmp = ie2[1] - ie1[1];
 454
 455                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 456                                        a_ies->data, a_ies->len);
 457                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 458                                        b_ies->data, b_ies->len);
 459                 if (ie1 && ie2) {
 460                         if (mesh_id_cmp)
 461                                 return mesh_id_cmp;
 462                         if (ie1[1] != ie2[1])
 463                                 return ie2[1] - ie1[1];
 464                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 465                 }
 466         }
 467
 468         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 469         if (r)
 470                 return r;
 471
 472         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 473         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 474
 475         if (!ie1 && !ie2)
 476                 return 0;
 477
 478         /*
 479          * Note that with "hide_ssid", the function returns a match if
 480          * the already-present BSS ("b") is a hidden SSID beacon for
 481          * the new BSS ("a").
 482          */
 483
 484         /* sort missing IE before (left of) present IE */
 485         if (!ie1)
 486                 return -1;
 487         if (!ie2)
 488                 return 1;
 489
 490         switch (mode) {
 491         case BSS_CMP_HIDE_ZLEN:
 492                 /*
 493                  * In ZLEN mode we assume the BSS entry we're
 494                  * looking for has a zero-length SSID. So if
 495                  * the one we're looking at right now has that,
 496                  * return 0. Otherwise, return the difference
 497                  * in length, but since we're looking for the
 498                  * 0-length it's really equivalent to returning
 499                  * the length of the one we're looking at.
 500                  *
 501                  * No content comparison is needed as we assume
 502                  * the content length is zero.
 503                  */
 504                 return ie2[1];
 505         case BSS_CMP_REGULAR:
 506         default:
 507                 /* sort by length first, then by contents */
 508                 if (ie1[1] != ie2[1])
 509                         return ie2[1] - ie1[1];
 510                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 511         case BSS_CMP_HIDE_NUL:
 512                 if (ie1[1] != ie2[1])
 513                         return ie2[1] - ie1[1];
 514                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 515                 for (i = 0; i < ie2[1]; i++)
 516                         if (ie2[i + 2])
 517                                 return -1;
 518                 return 0;
 519         }
 520 }
 521
 522 /* Returned bss is reference counted and must be cleaned up appropriately. */
 523 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 524                                       struct ieee80211_channel *channel,
 525                                       const u8 *bssid,
 526                                       const u8 *ssid, size_t ssid_len,
 527                                       u16 capa_mask, u16 capa_val)
 528 {
 529         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 530         struct cfg80211_internal_bss *bss, *res = NULL;
 531         unsigned long now = jiffies;
 532
 533         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 534                                capa_val);
 535
 536         spin_lock_bh(&dev->bss_lock);
 537
 538         list_for_each_entry(bss, &dev->bss_list, list) {
 539                 if ((bss->pub.capability & capa_mask) != capa_val)
 540                         continue;
 541                 if (channel && bss->pub.channel != channel)
 542                         continue;
 543                 /* Don't get expired BSS structs */
 544                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 545                     !atomic_read(&bss->hold))
 546                         continue;
 547                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 548                         res = bss;
 549                         bss_ref_get(dev, res);
 550                         break;
 551                 }
 552         }
 553
 554         spin_unlock_bh(&dev->bss_lock);
 555         if (!res)
 556                 return NULL;
 557         trace_cfg80211_return_bss(&res->pub);
 558         return &res->pub;
 559 }
 560 EXPORT_SYMBOL(cfg80211_get_bss);
 561
 562 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 563                           struct cfg80211_internal_bss *bss)
 564 {
 565         struct rb_node **p = &dev->bss_tree.rb_node;
 566         struct rb_node *parent = NULL;
 567         struct cfg80211_internal_bss *tbss;
 568         int cmp;
 569
 570         while (*p) {
 571                 parent = *p;
 572                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 573
 574                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 575
 576                 if (WARN_ON(!cmp)) {
 577                         /* will sort of leak this BSS */
 578                         return;
 579                 }
 580
 581                 if (cmp < 0)
 582                         p = &(*p)->rb_left;
 583                 else
 584                         p = &(*p)->rb_right;
 585         }
 586
 587         rb_link_node(&bss->rbn, parent, p);
 588         rb_insert_color(&bss->rbn, &dev->bss_tree);
 589 }
 590
 591 static struct cfg80211_internal_bss *
 592 rb_find_bss(struct cfg80211_registered_device *dev,
 593             struct cfg80211_internal_bss *res,
 594             enum bss_compare_mode mode)
 595 {
 596         struct rb_node *n = dev->bss_tree.rb_node;
 597         struct cfg80211_internal_bss *bss;
 598         int r;
 599
 600         while (n) {
 601                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 602                 r = cmp_bss(&res->pub, &bss->pub, mode);
 603
 604                 if (r == 0)
 605                         return bss;
 606                 else if (r < 0)
 607                         n = n->rb_left;
 608                 else
 609                         n = n->rb_right;
 610         }
 611
 612         return NULL;
 613 }
 614
 615 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
 616                                    struct cfg80211_internal_bss *new)
 617 {
 618         const struct cfg80211_bss_ies *ies;
 619         struct cfg80211_internal_bss *bss;
 620         const u8 *ie;
 621         int i, ssidlen;
 622         u8 fold = 0;
 623
 624         ies = rcu_access_pointer(new->pub.beacon_ies);
 625         if (WARN_ON(!ies))
 626                 return false;
 627
 628         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 629         if (!ie) {
 630                 /* nothing to do */
 631                 return true;
 632         }
 633
 634         ssidlen = ie[1];
 635         for (i = 0; i < ssidlen; i++)
 636                 fold |= ie[2 + i];
 637
 638         if (fold) {
 639                 /* not a hidden SSID */
 640                 return true;
 641         }
 642
 643         /* This is the bad part ... */
 644
 645         list_for_each_entry(bss, &dev->bss_list, list) {
 646                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 647                         continue;
 648                 if (bss->pub.channel != new->pub.channel)
 649                         continue;
 650                 if (bss->pub.scan_width != new->pub.scan_width)
 651                         continue;
 652                 if (rcu_access_pointer(bss->pub.beacon_ies))
 653                         continue;
 654                 ies = rcu_access_pointer(bss->pub.ies);
 655                 if (!ies)
 656                         continue;
 657                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 658                 if (!ie)
 659                         continue;
 660                 if (ssidlen && ie[1] != ssidlen)
 661                         continue;
 662                 /* that would be odd ... */
 663                 if (bss->pub.beacon_ies)
 664                         continue;
 665                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 666                         continue;
 667                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 668                         list_del(&bss->hidden_list);
 669                 /* combine them */
 670                 list_add(&bss->hidden_list, &new->hidden_list);
 671                 bss->pub.hidden_beacon_bss = &new->pub;
 672                 new->refcount += bss->refcount;
 673                 rcu_assign_pointer(bss->pub.beacon_ies,
 674                                    new->pub.beacon_ies);
 675         }
 676
 677         return true;
 678 }
 679
 680 /* Returned bss is reference counted and must be cleaned up appropriately. */
 681 static struct cfg80211_internal_bss *
 682 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 683                     struct cfg80211_internal_bss *tmp)
 684 {
 685         struct cfg80211_internal_bss *found = NULL;
 686
 687         if (WARN_ON(!tmp->pub.channel))
 688                 return NULL;
 689
 690         tmp->ts = jiffies;
 691
 692         spin_lock_bh(&dev->bss_lock);
 693
 694         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 695                 spin_unlock_bh(&dev->bss_lock);
 696                 return NULL;
 697         }
 698
 699         found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
 700
 701         if (found) {
 702                 /* Update IEs */
 703                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 704                         const struct cfg80211_bss_ies *old;
 705
 706                         old = rcu_access_pointer(found->pub.proberesp_ies);
 707
 708                         rcu_assign_pointer(found->pub.proberesp_ies,
 709                                            tmp->pub.proberesp_ies);
 710                         /* Override possible earlier Beacon frame IEs */
 711                         rcu_assign_pointer(found->pub.ies,
 712                                            tmp->pub.proberesp_ies);
 713                         if (old)
 714                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 715                                           rcu_head);
 716                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 717                         const struct cfg80211_bss_ies *old;
 718                         struct cfg80211_internal_bss *bss;
 719
 720                         if (found->pub.hidden_beacon_bss &&
 721                             !list_empty(&found->hidden_list)) {
 722                                 const struct cfg80211_bss_ies *f;
 723
 724                                 /*
 725                                  * The found BSS struct is one of the probe
 726                                  * response members of a group, but we're
 727                                  * receiving a beacon (beacon_ies in the tmp
 728                                  * bss is used). This can only mean that the
 729                                  * AP changed its beacon from not having an
 730                                  * SSID to showing it, which is confusing so
 731                                  * drop this information.
 732                                  */
 733
 734                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 735                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 736                                           rcu_head);
 737                                 goto drop;
 738                         }
 739
 740                         old = rcu_access_pointer(found->pub.beacon_ies);
 741
 742                         rcu_assign_pointer(found->pub.beacon_ies,
 743                                            tmp->pub.beacon_ies);
 744
 745                         /* Override IEs if they were from a beacon before */
 746                         if (old == rcu_access_pointer(found->pub.ies))
 747                                 rcu_assign_pointer(found->pub.ies,
 748                                                    tmp->pub.beacon_ies);
 749
 750                         /* Assign beacon IEs to all sub entries */
 751                         list_for_each_entry(bss, &found->hidden_list,
 752                                             hidden_list) {
 753                                 const struct cfg80211_bss_ies *ies;
 754
 755                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 756                                 WARN_ON(ies != old);
 757
 758                                 rcu_assign_pointer(bss->pub.beacon_ies,
 759                                                    tmp->pub.beacon_ies);
 760                         }
 761
 762                         if (old)
 763                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 764                                           rcu_head);
 765                 }
 766
 767                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 768                 found->pub.signal = tmp->pub.signal;
 769                 found->pub.capability = tmp->pub.capability;
 770                 found->ts = tmp->ts;
 771         } else {
 772                 struct cfg80211_internal_bss *new;
 773                 struct cfg80211_internal_bss *hidden;
 774                 struct cfg80211_bss_ies *ies;
 775
 776                 /*
 777                  * create a copy -- the "res" variable that is passed in
 778                  * is allocated on the stack since it's not needed in the
 779                  * more common case of an update
 780                  */
 781                 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
 782                               GFP_ATOMIC);
 783                 if (!new) {
 784                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 785                         if (ies)
 786                                 kfree_rcu(ies, rcu_head);
 787                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 788                         if (ies)
 789                                 kfree_rcu(ies, rcu_head);
 790                         goto drop;
 791                 }
 792                 memcpy(new, tmp, sizeof(*new));
 793                 new->refcount = 1;
 794                 INIT_LIST_HEAD(&new->hidden_list);
 795
 796                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 797                         hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
 798                         if (!hidden)
 799                                 hidden = rb_find_bss(dev, tmp,
 800                                                      BSS_CMP_HIDE_NUL);
 801                         if (hidden) {
 802                                 new->pub.hidden_beacon_bss = &hidden->pub;
 803                                 list_add(&new->hidden_list,
 804                                          &hidden->hidden_list);
 805                                 hidden->refcount++;
 806                                 rcu_assign_pointer(new->pub.beacon_ies,
 807                                                    hidden->pub.beacon_ies);
 808                         }
 809                 } else {
 810                         /*
 811                          * Ok so we found a beacon, and don't have an entry. If
 812                          * it's a beacon with hidden SSID, we might be in for an
 813                          * expensive search for any probe responses that should
 814                          * be grouped with this beacon for updates ...
 815                          */
 816                         if (!cfg80211_combine_bsses(dev, new)) {
 817                                 kfree(new);
 818                                 goto drop;
 819                         }
 820                 }
 821
 822                 list_add_tail(&new->list, &dev->bss_list);
 823                 rb_insert_bss(dev, new);
 824                 found = new;
 825         }
 826
 827         dev->bss_generation++;
 828         bss_ref_get(dev, found);
 829         spin_unlock_bh(&dev->bss_lock);
 830
 831         return found;
 832  drop:
 833         spin_unlock_bh(&dev->bss_lock);
 834         return NULL;
 835 }
 836
 837 static struct ieee80211_channel *
 838 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 839                          struct ieee80211_channel *channel)
 840 {
 841         const u8 *tmp;
 842         u32 freq;
 843         int channel_number = -1;
 844
 845         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 846         if (tmp && tmp[1] == 1) {
 847                 channel_number = tmp[2];
 848         } else {
 849                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 850                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 851                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 852
 853                         channel_number = htop->primary_chan;
 854                 }
 855         }
 856
 857         if (channel_number < 0)
 858                 return channel;
 859
 860         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 861         channel = ieee80211_get_channel(wiphy, freq);
 862         if (!channel)
 863                 return NULL;
 864         if (channel->flags & IEEE80211_CHAN_DISABLED)
 865                 return NULL;
 866         return channel;
 867 }
 868
 869 /* Returned bss is reference counted and must be cleaned up appropriately. */
 870 struct cfg80211_bss*
 871 cfg80211_inform_bss_width(struct wiphy *wiphy,
 872                           struct ieee80211_channel *channel,
 873                           enum nl80211_bss_scan_width scan_width,
 874                           const u8 *bssid, u64 tsf, u16 capability,
 875                           u16 beacon_interval, const u8 *ie, size_t ielen,
 876                           s32 signal, gfp_t gfp)
 877 {
 878         struct cfg80211_bss_ies *ies;
 879         struct cfg80211_internal_bss tmp = {}, *res;
 880
 881         if (WARN_ON(!wiphy))
 882                 return NULL;
 883
 884         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 885                         (signal < 0 || signal > 100)))
 886                 return NULL;
 887
 888         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
 889         if (!channel)
 890                 return NULL;
 891
 892         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 893         tmp.pub.channel = channel;
 894         tmp.pub.scan_width = scan_width;
 895         tmp.pub.signal = signal;
 896         tmp.pub.beacon_interval = beacon_interval;
 897         tmp.pub.capability = capability;
 898         /*
 899          * Since we do not know here whether the IEs are from a Beacon or Probe
 900          * Response frame, we need to pick one of the options and only use it
 901          * with the driver that does not provide the full Beacon/Probe Response
 902          * frame. Use Beacon frame pointer to avoid indicating that this should
 903          * override the IEs pointer should we have received an earlier
 904          * indication of Probe Response data.
 905          */
 906         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 907         if (!ies)
 908                 return NULL;
 909         ies->len = ielen;
 910         ies->tsf = tsf;
 911         memcpy(ies->data, ie, ielen);
 912
 913         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 914         rcu_assign_pointer(tmp.pub.ies, ies);
 915
 916         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 917         if (!res)
 918                 return NULL;
 919
 920         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 921                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 922
 923         trace_cfg80211_return_bss(&res->pub);
 924         /* cfg80211_bss_update gives us a referenced result */
 925         return &res->pub;
 926 }
 927 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 928
 929 /* Returned bss is reference counted and must be cleaned up appropriately. */
 930 struct cfg80211_bss *
 931 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 932                                 struct ieee80211_channel *channel,
 933                                 enum nl80211_bss_scan_width scan_width,
 934                                 struct ieee80211_mgmt *mgmt, size_t len,
 935                                 s32 signal, gfp_t gfp)
 936 {
 937         struct cfg80211_internal_bss tmp = {}, *res;
 938         struct cfg80211_bss_ies *ies;
 939         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 940                                       u.probe_resp.variable);
 941
 942         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 943                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 944
 945         trace_cfg80211_inform_bss_width_frame(wiphy, channel, scan_width, mgmt,
 946                                               len, signal);
 947
 948         if (WARN_ON(!mgmt))
 949                 return NULL;
 950
 951         if (WARN_ON(!wiphy))
 952                 return NULL;
 953
 954         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 955                     (signal < 0 || signal > 100)))
 956                 return NULL;
 957
 958         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 959                 return NULL;
 960
 961         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 962                                            ielen, channel);
 963         if (!channel)
 964                 return NULL;
 965
 966         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 967         if (!ies)
 968                 return NULL;
 969         ies->len = ielen;
 970         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 971         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 972
 973         if (ieee80211_is_probe_resp(mgmt->frame_control))
 974                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 975         else
 976                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 977         rcu_assign_pointer(tmp.pub.ies, ies);
 978
 979         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 980         tmp.pub.channel = channel;
 981         tmp.pub.scan_width = scan_width;
 982         tmp.pub.signal = signal;
 983         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 984         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 985
 986         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 987         if (!res)
 988                 return NULL;
 989
 990         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 991                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 992
 993         trace_cfg80211_return_bss(&res->pub);
 994         /* cfg80211_bss_update gives us a referenced result */
 995         return &res->pub;
 996 }
 997 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
 998
 999 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1000 {
1001         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1002         struct cfg80211_internal_bss *bss;
1003
1004         if (!pub)
1005                 return;
1006
1007         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1008
1009         spin_lock_bh(&dev->bss_lock);
1010         bss_ref_get(dev, bss);
1011         spin_unlock_bh(&dev->bss_lock);
1012 }
1013 EXPORT_SYMBOL(cfg80211_ref_bss);
1014
1015 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1016 {
1017         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1018         struct cfg80211_internal_bss *bss;
1019
1020         if (!pub)
1021                 return;
1022
1023         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1024
1025         spin_lock_bh(&dev->bss_lock);
1026         bss_ref_put(dev, bss);
1027         spin_unlock_bh(&dev->bss_lock);
1028 }
1029 EXPORT_SYMBOL(cfg80211_put_bss);
1030
1031 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1032 {
1033         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1034         struct cfg80211_internal_bss *bss;
1035
1036         if (WARN_ON(!pub))
1037                 return;
1038
1039         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1040
1041         spin_lock_bh(&dev->bss_lock);
1042         if (!list_empty(&bss->list)) {
1043                 if (__cfg80211_unlink_bss(dev, bss))
1044                         dev->bss_generation++;
1045         }
1046         spin_unlock_bh(&dev->bss_lock);
1047 }
1048 EXPORT_SYMBOL(cfg80211_unlink_bss);
1049
1050 #ifdef CONFIG_CFG80211_WEXT
1051 static struct cfg80211_registered_device *
1052 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1053 {
1054         struct cfg80211_registered_device *rdev;
1055         struct net_device *dev;
1056
1057         ASSERT_RTNL();
1058
1059         dev = dev_get_by_index(net, ifindex);
1060         if (!dev)
1061                 return ERR_PTR(-ENODEV);
1062         if (dev->ieee80211_ptr)
1063                 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
1064         else
1065                 rdev = ERR_PTR(-ENODEV);
1066         dev_put(dev);
1067         return rdev;
1068 }
1069
1070 int cfg80211_wext_siwscan(struct net_device *dev,
1071                           struct iw_request_info *info,
1072                           union iwreq_data *wrqu, char *extra)
1073 {
1074         struct cfg80211_registered_device *rdev;
1075         struct wiphy *wiphy;
1076         struct iw_scan_req *wreq = NULL;
1077         struct cfg80211_scan_request *creq = NULL;
1078         int i, err, n_channels = 0;
1079         enum ieee80211_band band;
1080
1081         if (!netif_running(dev))
1082                 return -ENETDOWN;
1083
1084         if (wrqu->data.length == sizeof(struct iw_scan_req))
1085                 wreq = (struct iw_scan_req *)extra;
1086
1087         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1088
1089         if (IS_ERR(rdev))
1090                 return PTR_ERR(rdev);
1091
1092         if (rdev->scan_req) {
1093                 err = -EBUSY;
1094                 goto out;
1095         }
1096
1097         wiphy = &rdev->wiphy;
1098
1099         /* Determine number of channels, needed to allocate creq */
1100         if (wreq && wreq->num_channels)
1101                 n_channels = wreq->num_channels;
1102         else {
1103                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1104                         if (wiphy->bands[band])
1105                                 n_channels += wiphy->bands[band]->n_channels;
1106         }
1107
1108         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1109                        n_channels * sizeof(void *),
1110                        GFP_ATOMIC);
1111         if (!creq) {
1112                 err = -ENOMEM;
1113                 goto out;
1114         }
1115
1116         creq->wiphy = wiphy;
1117         creq->wdev = dev->ieee80211_ptr;
1118         /* SSIDs come after channels */
1119         creq->ssids = (void *)&creq->channels[n_channels];
1120         creq->n_channels = n_channels;
1121         creq->n_ssids = 1;
1122         creq->scan_start = jiffies;
1123
1124         /* translate "Scan on frequencies" request */
1125         i = 0;
1126         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1127                 int j;
1128
1129                 if (!wiphy->bands[band])
1130                         continue;
1131
1132                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1133                         /* ignore disabled channels */
1134                         if (wiphy->bands[band]->channels[j].flags &
1135                                                 IEEE80211_CHAN_DISABLED)
1136                                 continue;
1137
1138                         /* If we have a wireless request structure and the
1139                          * wireless request specifies frequencies, then search
1140                          * for the matching hardware channel.
1141                          */
1142                         if (wreq && wreq->num_channels) {
1143                                 int k;
1144                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1145                                 for (k = 0; k < wreq->num_channels; k++) {
1146                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1147                                         if (wext_freq == wiphy_freq)
1148                                                 goto wext_freq_found;
1149                                 }
1150                                 goto wext_freq_not_found;
1151                         }
1152
1153                 wext_freq_found:
1154                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1155                         i++;
1156                 wext_freq_not_found: ;
1157                 }
1158         }
1159         /* No channels found? */
1160         if (!i) {
1161                 err = -EINVAL;
1162                 goto out;
1163         }
1164
1165         /* Set real number of channels specified in creq->channels[] */
1166         creq->n_channels = i;
1167
1168         /* translate "Scan for SSID" request */
1169         if (wreq) {
1170                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1171                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1172                                 err = -EINVAL;
1173                                 goto out;
1174                         }
1175                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1176                         creq->ssids[0].ssid_len = wreq->essid_len;
1177                 }
1178                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1179                         creq->n_ssids = 0;
1180         }
1181
1182         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1183                 if (wiphy->bands[i])
1184                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1185
1186         rdev->scan_req = creq;
1187         err = rdev_scan(rdev, creq);
1188         if (err) {
1189                 rdev->scan_req = NULL;
1190                 /* creq will be freed below */
1191         } else {
1192                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1193                 /* creq now owned by driver */
1194                 creq = NULL;
1195                 dev_hold(dev);
1196         }
1197  out:
1198         kfree(creq);
1199         return err;
1200 }
1201 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1202
1203 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1204                                    const struct cfg80211_bss_ies *ies,
1205                                    char **current_ev, char *end_buf)
1206 {
1207         const u8 *pos, *end, *next;
1208         struct iw_event iwe;
1209
1210         if (!ies)
1211                 return;
1212
1213         /*
1214          * If needed, fragment the IEs buffer (at IE boundaries) into short
1215          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1216          */
1217         pos = ies->data;
1218         end = pos + ies->len;
1219
1220         while (end - pos > IW_GENERIC_IE_MAX) {
1221                 next = pos + 2 + pos[1];
1222                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1223                         next = next + 2 + next[1];
1224
1225                 memset(&iwe, 0, sizeof(iwe));
1226                 iwe.cmd = IWEVGENIE;
1227                 iwe.u.data.length = next - pos;
1228                 *current_ev = iwe_stream_add_point(info, *current_ev,
1229                                                    end_buf, &iwe,
1230                                                    (void *)pos);
1231
1232                 pos = next;
1233         }
1234
1235         if (end > pos) {
1236                 memset(&iwe, 0, sizeof(iwe));
1237                 iwe.cmd = IWEVGENIE;
1238                 iwe.u.data.length = end - pos;
1239                 *current_ev = iwe_stream_add_point(info, *current_ev,
1240                                                    end_buf, &iwe,
1241                                                    (void *)pos);
1242         }
1243 }
1244
1245 static char *
1246 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1247               struct cfg80211_internal_bss *bss, char *current_ev,
1248               char *end_buf)
1249 {
1250         const struct cfg80211_bss_ies *ies;
1251         struct iw_event iwe;
1252         const u8 *ie;
1253         u8 *buf, *cfg, *p;
1254         int rem, i, sig;
1255         bool ismesh = false;
1256
1257         memset(&iwe, 0, sizeof(iwe));
1258         iwe.cmd = SIOCGIWAP;
1259         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1260         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1261         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1262                                           IW_EV_ADDR_LEN);
1263
1264         memset(&iwe, 0, sizeof(iwe));
1265         iwe.cmd = SIOCGIWFREQ;
1266         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1267         iwe.u.freq.e = 0;
1268         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1269                                           IW_EV_FREQ_LEN);
1270
1271         memset(&iwe, 0, sizeof(iwe));
1272         iwe.cmd = SIOCGIWFREQ;
1273         iwe.u.freq.m = bss->pub.channel->center_freq;
1274         iwe.u.freq.e = 6;
1275         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1276                                           IW_EV_FREQ_LEN);
1277
1278         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1279                 memset(&iwe, 0, sizeof(iwe));
1280                 iwe.cmd = IWEVQUAL;
1281                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1282                                      IW_QUAL_NOISE_INVALID |
1283                                      IW_QUAL_QUAL_UPDATED;
1284                 switch (wiphy->signal_type) {
1285                 case CFG80211_SIGNAL_TYPE_MBM:
1286                         sig = bss->pub.signal / 100;
1287                         iwe.u.qual.level = sig;
1288                         iwe.u.qual.updated |= IW_QUAL_DBM;
1289                         if (sig < -110)         /* rather bad */
1290                                 sig = -110;
1291                         else if (sig > -40)     /* perfect */
1292                                 sig = -40;
1293                         /* will give a range of 0 .. 70 */
1294                         iwe.u.qual.qual = sig + 110;
1295                         break;
1296                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1297                         iwe.u.qual.level = bss->pub.signal;
1298                         /* will give range 0 .. 100 */
1299                         iwe.u.qual.qual = bss->pub.signal;
1300                         break;
1301                 default:
1302                         /* not reached */
1303                         break;
1304                 }
1305                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1306                                                   &iwe, IW_EV_QUAL_LEN);
1307         }
1308
1309         memset(&iwe, 0, sizeof(iwe));
1310         iwe.cmd = SIOCGIWENCODE;
1311         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1312                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1313         else
1314                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1315         iwe.u.data.length = 0;
1316         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1317                                           &iwe, "");
1318
1319         rcu_read_lock();
1320         ies = rcu_dereference(bss->pub.ies);
1321         rem = ies->len;
1322         ie = ies->data;
1323
1324         while (rem >= 2) {
1325                 /* invalid data */
1326                 if (ie[1] > rem - 2)
1327                         break;
1328
1329                 switch (ie[0]) {
1330                 case WLAN_EID_SSID:
1331                         memset(&iwe, 0, sizeof(iwe));
1332                         iwe.cmd = SIOCGIWESSID;
1333                         iwe.u.data.length = ie[1];
1334                         iwe.u.data.flags = 1;
1335                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1336                                                           &iwe, (u8 *)ie + 2);
1337                         break;
1338                 case WLAN_EID_MESH_ID:
1339                         memset(&iwe, 0, sizeof(iwe));
1340                         iwe.cmd = SIOCGIWESSID;
1341                         iwe.u.data.length = ie[1];
1342                         iwe.u.data.flags = 1;
1343                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1344                                                           &iwe, (u8 *)ie + 2);
1345                         break;
1346                 case WLAN_EID_MESH_CONFIG:
1347                         ismesh = true;
1348                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1349                                 break;
1350                         buf = kmalloc(50, GFP_ATOMIC);
1351                         if (!buf)
1352                                 break;
1353                         cfg = (u8 *)ie + 2;
1354                         memset(&iwe, 0, sizeof(iwe));
1355                         iwe.cmd = IWEVCUSTOM;
1356                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1357                                 "0x%02X", cfg[0]);
1358                         iwe.u.data.length = strlen(buf);
1359                         current_ev = iwe_stream_add_point(info, current_ev,
1360                                                           end_buf,
1361                                                           &iwe, buf);
1362                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1363                                 cfg[1]);
1364                         iwe.u.data.length = strlen(buf);
1365                         current_ev = iwe_stream_add_point(info, current_ev,
1366                                                           end_buf,
1367                                                           &iwe, buf);
1368                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1369                                 cfg[2]);
1370                         iwe.u.data.length = strlen(buf);
1371                         current_ev = iwe_stream_add_point(info, current_ev,
1372                                                           end_buf,
1373                                                           &iwe, buf);
1374                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1375                         iwe.u.data.length = strlen(buf);
1376                         current_ev = iwe_stream_add_point(info, current_ev,
1377                                                           end_buf,
1378                                                           &iwe, buf);
1379                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1380                         iwe.u.data.length = strlen(buf);
1381                         current_ev = iwe_stream_add_point(info, current_ev,
1382                                                           end_buf,
1383                                                           &iwe, buf);
1384                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1385                         iwe.u.data.length = strlen(buf);
1386                         current_ev = iwe_stream_add_point(info, current_ev,
1387                                                           end_buf,
1388                                                           &iwe, buf);
1389                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1390                         iwe.u.data.length = strlen(buf);
1391                         current_ev = iwe_stream_add_point(info, current_ev,
1392                                                           end_buf,
1393                                                           &iwe, buf);
1394                         kfree(buf);
1395                         break;
1396                 case WLAN_EID_SUPP_RATES:
1397                 case WLAN_EID_EXT_SUPP_RATES:
1398                         /* display all supported rates in readable format */
1399                         p = current_ev + iwe_stream_lcp_len(info);
1400
1401                         memset(&iwe, 0, sizeof(iwe));
1402                         iwe.cmd = SIOCGIWRATE;
1403                         /* Those two flags are ignored... */
1404                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1405
1406                         for (i = 0; i < ie[1]; i++) {
1407                                 iwe.u.bitrate.value =
1408                                         ((ie[i + 2] & 0x7f) * 500000);
1409                                 p = iwe_stream_add_value(info, current_ev, p,
1410                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1411                         }
1412                         current_ev = p;
1413                         break;
1414                 }
1415                 rem -= ie[1] + 2;
1416                 ie += ie[1] + 2;
1417         }
1418
1419         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1420             ismesh) {
1421                 memset(&iwe, 0, sizeof(iwe));
1422                 iwe.cmd = SIOCGIWMODE;
1423                 if (ismesh)
1424                         iwe.u.mode = IW_MODE_MESH;
1425                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1426                         iwe.u.mode = IW_MODE_MASTER;
1427                 else
1428                         iwe.u.mode = IW_MODE_ADHOC;
1429                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1430                                                   &iwe, IW_EV_UINT_LEN);
1431         }
1432
1433         buf = kmalloc(31, GFP_ATOMIC);
1434         if (buf) {
1435                 memset(&iwe, 0, sizeof(iwe));
1436                 iwe.cmd = IWEVCUSTOM;
1437                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1438                 iwe.u.data.length = strlen(buf);
1439                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1440                                                   &iwe, buf);
1441                 memset(&iwe, 0, sizeof(iwe));
1442                 iwe.cmd = IWEVCUSTOM;
1443                 sprintf(buf, " Last beacon: %ums ago",
1444                         elapsed_jiffies_msecs(bss->ts));
1445                 iwe.u.data.length = strlen(buf);
1446                 current_ev = iwe_stream_add_point(info, current_ev,
1447                                                   end_buf, &iwe, buf);
1448                 kfree(buf);
1449         }
1450
1451         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1452         rcu_read_unlock();
1453
1454         return current_ev;
1455 }
1456
1457
1458 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1459                                   struct iw_request_info *info,
1460                                   char *buf, size_t len)
1461 {
1462         char *current_ev = buf;
1463         char *end_buf = buf + len;
1464         struct cfg80211_internal_bss *bss;
1465
1466         spin_lock_bh(&dev->bss_lock);
1467         cfg80211_bss_expire(dev);
1468
1469         list_for_each_entry(bss, &dev->bss_list, list) {
1470                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1471                         spin_unlock_bh(&dev->bss_lock);
1472                         return -E2BIG;
1473                 }
1474                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1475                                            current_ev, end_buf);
1476         }
1477         spin_unlock_bh(&dev->bss_lock);
1478         return current_ev - buf;
1479 }
1480
1481
1482 int cfg80211_wext_giwscan(struct net_device *dev,
1483                           struct iw_request_info *info,
1484                           struct iw_point *data, char *extra)
1485 {
1486         struct cfg80211_registered_device *rdev;
1487         int res;
1488
1489         if (!netif_running(dev))
1490                 return -ENETDOWN;
1491
1492         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1493
1494         if (IS_ERR(rdev))
1495                 return PTR_ERR(rdev);
1496
1497         if (rdev->scan_req)
1498                 return -EAGAIN;
1499
1500         res = ieee80211_scan_results(rdev, info, extra, data->length);
1501         data->length = 0;
1502         if (res >= 0) {
1503                 data->length = res;
1504                 res = 0;
1505         }
1506
1507         return res;
1508 }
1509 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1510 #endif