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         lockdep_assert_held(&rdev->sched_scan_mtx);
 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         mutex_lock(&rdev->sched_scan_mtx);
 234         ___cfg80211_scan_done(rdev, false);
 235         mutex_unlock(&rdev->sched_scan_mtx);
 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         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
 245 }
 246 EXPORT_SYMBOL(cfg80211_scan_done);
 247
 248 void __cfg80211_sched_scan_results(struct work_struct *wk)
 249 {
 250         struct cfg80211_registered_device *rdev;
 251         struct cfg80211_sched_scan_request *request;
 252
 253         rdev = container_of(wk, struct cfg80211_registered_device,
 254                             sched_scan_results_wk);
 255
 256         mutex_lock(&rdev->sched_scan_mtx);
 257
 258         request = rdev->sched_scan_req;
 259
 260         /* we don't have sched_scan_req anymore if the scan is stopping */
 261         if (request) {
 262                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 263                         /* flush entries from previous scans */
 264                         spin_lock_bh(&rdev->bss_lock);
 265                         __cfg80211_bss_expire(rdev, request->scan_start);
 266                         spin_unlock_bh(&rdev->bss_lock);
 267                         request->scan_start =
 268                                 jiffies + msecs_to_jiffies(request->interval);
 269                 }
 270                 nl80211_send_sched_scan_results(rdev, request->dev);
 271         }
 272
 273         mutex_unlock(&rdev->sched_scan_mtx);
 274 }
 275
 276 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 277 {
 278         trace_cfg80211_sched_scan_results(wiphy);
 279         /* ignore if we're not scanning */
 280         if (wiphy_to_dev(wiphy)->sched_scan_req)
 281                 queue_work(cfg80211_wq,
 282                            &wiphy_to_dev(wiphy)->sched_scan_results_wk);
 283 }
 284 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 285
 286 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 287 {
 288         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 289
 290         trace_cfg80211_sched_scan_stopped(wiphy);
 291
 292         mutex_lock(&rdev->sched_scan_mtx);
 293         __cfg80211_stop_sched_scan(rdev, true);
 294         mutex_unlock(&rdev->sched_scan_mtx);
 295 }
 296 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 297
 298 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 299                                bool driver_initiated)
 300 {
 301         struct net_device *dev;
 302
 303         lockdep_assert_held(&rdev->sched_scan_mtx);
 304
 305         if (!rdev->sched_scan_req)
 306                 return -ENOENT;
 307
 308         dev = rdev->sched_scan_req->dev;
 309
 310         if (!driver_initiated) {
 311                 int err = rdev_sched_scan_stop(rdev, dev);
 312                 if (err)
 313                         return err;
 314         }
 315
 316         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 317
 318         kfree(rdev->sched_scan_req);
 319         rdev->sched_scan_req = NULL;
 320
 321         return 0;
 322 }
 323
 324 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 325                       unsigned long age_secs)
 326 {
 327         struct cfg80211_internal_bss *bss;
 328         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 329
 330         spin_lock_bh(&dev->bss_lock);
 331         list_for_each_entry(bss, &dev->bss_list, list)
 332                 bss->ts -= age_jiffies;
 333         spin_unlock_bh(&dev->bss_lock);
 334 }
 335
 336 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 337 {
 338         __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 339 }
 340
 341 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 342 {
 343         while (len > 2 && ies[0] != eid) {
 344                 len -= ies[1] + 2;
 345                 ies += ies[1] + 2;
 346         }
 347         if (len < 2)
 348                 return NULL;
 349         if (len < 2 + ies[1])
 350                 return NULL;
 351         return ies;
 352 }
 353 EXPORT_SYMBOL(cfg80211_find_ie);
 354
 355 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 356                                   const u8 *ies, int len)
 357 {
 358         struct ieee80211_vendor_ie *ie;
 359         const u8 *pos = ies, *end = ies + len;
 360         int ie_oui;
 361
 362         while (pos < end) {
 363                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 364                                        end - pos);
 365                 if (!pos)
 366                         return NULL;
 367
 368                 ie = (struct ieee80211_vendor_ie *)pos;
 369
 370                 /* make sure we can access ie->len */
 371                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 372
 373                 if (ie->len < sizeof(*ie))
 374                         goto cont;
 375
 376                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 377                 if (ie_oui == oui && ie->oui_type == oui_type)
 378                         return pos;
 379 cont:
 380                 pos += 2 + ie->len;
 381         }
 382         return NULL;
 383 }
 384 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 385
 386 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 387                    const u8 *ssid, size_t ssid_len)
 388 {
 389         const struct cfg80211_bss_ies *ies;
 390         const u8 *ssidie;
 391
 392         if (bssid && !ether_addr_equal(a->bssid, bssid))
 393                 return false;
 394
 395         if (!ssid)
 396                 return true;
 397
 398         ies = rcu_access_pointer(a->ies);
 399         if (!ies)
 400                 return false;
 401         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 402         if (!ssidie)
 403                 return false;
 404         if (ssidie[1] != ssid_len)
 405                 return false;
 406         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 407 }
 408
 409 /**
 410  * enum bss_compare_mode - BSS compare mode
 411  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 412  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 413  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 414  */
 415 enum bss_compare_mode {
 416         BSS_CMP_REGULAR,
 417         BSS_CMP_HIDE_ZLEN,
 418         BSS_CMP_HIDE_NUL,
 419 };
 420
 421 static int cmp_bss(struct cfg80211_bss *a,
 422                    struct cfg80211_bss *b,
 423                    enum bss_compare_mode mode)
 424 {
 425         const struct cfg80211_bss_ies *a_ies, *b_ies;
 426         const u8 *ie1 = NULL;
 427         const u8 *ie2 = NULL;
 428         int i, r;
 429
 430         if (a->channel != b->channel)
 431                 return b->channel->center_freq - a->channel->center_freq;
 432
 433         a_ies = rcu_access_pointer(a->ies);
 434         if (!a_ies)
 435                 return -1;
 436         b_ies = rcu_access_pointer(b->ies);
 437         if (!b_ies)
 438                 return 1;
 439
 440         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 441                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 442                                        a_ies->data, a_ies->len);
 443         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 444                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 445                                        b_ies->data, b_ies->len);
 446         if (ie1 && ie2) {
 447                 int mesh_id_cmp;
 448
 449                 if (ie1[1] == ie2[1])
 450                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 451                 else
 452                         mesh_id_cmp = ie2[1] - ie1[1];
 453
 454                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 455                                        a_ies->data, a_ies->len);
 456                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 457                                        b_ies->data, b_ies->len);
 458                 if (ie1 && ie2) {
 459                         if (mesh_id_cmp)
 460                                 return mesh_id_cmp;
 461                         if (ie1[1] != ie2[1])
 462                                 return ie2[1] - ie1[1];
 463                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 464                 }
 465         }
 466
 467         /*
 468          * we can't use compare_ether_addr here since we need a < > operator.
 469          * The binary return value of compare_ether_addr isn't enough
 470          */
 471         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 472         if (r)
 473                 return r;
 474
 475         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 476         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 477
 478         if (!ie1 && !ie2)
 479                 return 0;
 480
 481         /*
 482          * Note that with "hide_ssid", the function returns a match if
 483          * the already-present BSS ("b") is a hidden SSID beacon for
 484          * the new BSS ("a").
 485          */
 486
 487         /* sort missing IE before (left of) present IE */
 488         if (!ie1)
 489                 return -1;
 490         if (!ie2)
 491                 return 1;
 492
 493         switch (mode) {
 494         case BSS_CMP_HIDE_ZLEN:
 495                 /*
 496                  * In ZLEN mode we assume the BSS entry we're
 497                  * looking for has a zero-length SSID. So if
 498                  * the one we're looking at right now has that,
 499                  * return 0. Otherwise, return the difference
 500                  * in length, but since we're looking for the
 501                  * 0-length it's really equivalent to returning
 502                  * the length of the one we're looking at.
 503                  *
 504                  * No content comparison is needed as we assume
 505                  * the content length is zero.
 506                  */
 507                 return ie2[1];
 508         case BSS_CMP_REGULAR:
 509         default:
 510                 /* sort by length first, then by contents */
 511                 if (ie1[1] != ie2[1])
 512                         return ie2[1] - ie1[1];
 513                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 514         case BSS_CMP_HIDE_NUL:
 515                 if (ie1[1] != ie2[1])
 516                         return ie2[1] - ie1[1];
 517                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 518                 for (i = 0; i < ie2[1]; i++)
 519                         if (ie2[i + 2])
 520                                 return -1;
 521                 return 0;
 522         }
 523 }
 524
 525 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 526                                       struct ieee80211_channel *channel,
 527                                       const u8 *bssid,
 528                                       const u8 *ssid, size_t ssid_len,
 529                                       u16 capa_mask, u16 capa_val)
 530 {
 531         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 532         struct cfg80211_internal_bss *bss, *res = NULL;
 533         unsigned long now = jiffies;
 534
 535         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 536                                capa_val);
 537
 538         spin_lock_bh(&dev->bss_lock);
 539
 540         list_for_each_entry(bss, &dev->bss_list, list) {
 541                 if ((bss->pub.capability & capa_mask) != capa_val)
 542                         continue;
 543                 if (channel && bss->pub.channel != channel)
 544                         continue;
 545                 /* Don't get expired BSS structs */
 546                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 547                     !atomic_read(&bss->hold))
 548                         continue;
 549                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 550                         res = bss;
 551                         bss_ref_get(dev, res);
 552                         break;
 553                 }
 554         }
 555
 556         spin_unlock_bh(&dev->bss_lock);
 557         if (!res)
 558                 return NULL;
 559         trace_cfg80211_return_bss(&res->pub);
 560         return &res->pub;
 561 }
 562 EXPORT_SYMBOL(cfg80211_get_bss);
 563
 564 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 565                           struct cfg80211_internal_bss *bss)
 566 {
 567         struct rb_node **p = &dev->bss_tree.rb_node;
 568         struct rb_node *parent = NULL;
 569         struct cfg80211_internal_bss *tbss;
 570         int cmp;
 571
 572         while (*p) {
 573                 parent = *p;
 574                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 575
 576                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 577
 578                 if (WARN_ON(!cmp)) {
 579                         /* will sort of leak this BSS */
 580                         return;
 581                 }
 582
 583                 if (cmp < 0)
 584                         p = &(*p)->rb_left;
 585                 else
 586                         p = &(*p)->rb_right;
 587         }
 588
 589         rb_link_node(&bss->rbn, parent, p);
 590         rb_insert_color(&bss->rbn, &dev->bss_tree);
 591 }
 592
 593 static struct cfg80211_internal_bss *
 594 rb_find_bss(struct cfg80211_registered_device *dev,
 595             struct cfg80211_internal_bss *res,
 596             enum bss_compare_mode mode)
 597 {
 598         struct rb_node *n = dev->bss_tree.rb_node;
 599         struct cfg80211_internal_bss *bss;
 600         int r;
 601
 602         while (n) {
 603                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 604                 r = cmp_bss(&res->pub, &bss->pub, mode);
 605
 606                 if (r == 0)
 607                         return bss;
 608                 else if (r < 0)
 609                         n = n->rb_left;
 610                 else
 611                         n = n->rb_right;
 612         }
 613
 614         return NULL;
 615 }
 616
 617 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
 618                                    struct cfg80211_internal_bss *new)
 619 {
 620         const struct cfg80211_bss_ies *ies;
 621         struct cfg80211_internal_bss *bss;
 622         const u8 *ie;
 623         int i, ssidlen;
 624         u8 fold = 0;
 625
 626         ies = rcu_access_pointer(new->pub.beacon_ies);
 627         if (WARN_ON(!ies))
 628                 return false;
 629
 630         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 631         if (!ie) {
 632                 /* nothing to do */
 633                 return true;
 634         }
 635
 636         ssidlen = ie[1];
 637         for (i = 0; i < ssidlen; i++)
 638                 fold |= ie[2 + i];
 639
 640         if (fold) {
 641                 /* not a hidden SSID */
 642                 return true;
 643         }
 644
 645         /* This is the bad part ... */
 646
 647         list_for_each_entry(bss, &dev->bss_list, list) {
 648                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 649                         continue;
 650                 if (bss->pub.channel != new->pub.channel)
 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 static struct cfg80211_internal_bss *
 681 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 682                     struct cfg80211_internal_bss *tmp)
 683 {
 684         struct cfg80211_internal_bss *found = NULL;
 685
 686         if (WARN_ON(!tmp->pub.channel))
 687                 return NULL;
 688
 689         tmp->ts = jiffies;
 690
 691         spin_lock_bh(&dev->bss_lock);
 692
 693         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 694                 spin_unlock_bh(&dev->bss_lock);
 695                 return NULL;
 696         }
 697
 698         found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
 699
 700         if (found) {
 701                 /* Update IEs */
 702                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 703                         const struct cfg80211_bss_ies *old;
 704
 705                         old = rcu_access_pointer(found->pub.proberesp_ies);
 706
 707                         rcu_assign_pointer(found->pub.proberesp_ies,
 708                                            tmp->pub.proberesp_ies);
 709                         /* Override possible earlier Beacon frame IEs */
 710                         rcu_assign_pointer(found->pub.ies,
 711                                            tmp->pub.proberesp_ies);
 712                         if (old)
 713                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 714                                           rcu_head);
 715                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 716                         const struct cfg80211_bss_ies *old;
 717                         struct cfg80211_internal_bss *bss;
 718
 719                         if (found->pub.hidden_beacon_bss &&
 720                             !list_empty(&found->hidden_list)) {
 721                                 const struct cfg80211_bss_ies *f;
 722
 723                                 /*
 724                                  * The found BSS struct is one of the probe
 725                                  * response members of a group, but we're
 726                                  * receiving a beacon (beacon_ies in the tmp
 727                                  * bss is used). This can only mean that the
 728                                  * AP changed its beacon from not having an
 729                                  * SSID to showing it, which is confusing so
 730                                  * drop this information.
 731                                  */
 732
 733                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 734                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 735                                           rcu_head);
 736                                 goto drop;
 737                         }
 738
 739                         old = rcu_access_pointer(found->pub.beacon_ies);
 740
 741                         rcu_assign_pointer(found->pub.beacon_ies,
 742                                            tmp->pub.beacon_ies);
 743
 744                         /* Override IEs if they were from a beacon before */
 745                         if (old == rcu_access_pointer(found->pub.ies))
 746                                 rcu_assign_pointer(found->pub.ies,
 747                                                    tmp->pub.beacon_ies);
 748
 749                         /* Assign beacon IEs to all sub entries */
 750                         list_for_each_entry(bss, &found->hidden_list,
 751                                             hidden_list) {
 752                                 const struct cfg80211_bss_ies *ies;
 753
 754                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 755                                 WARN_ON(ies != old);
 756
 757                                 rcu_assign_pointer(bss->pub.beacon_ies,
 758                                                    tmp->pub.beacon_ies);
 759                         }
 760
 761                         if (old)
 762                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 763                                           rcu_head);
 764                 }
 765
 766                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 767                 found->pub.signal = tmp->pub.signal;
 768                 found->pub.capability = tmp->pub.capability;
 769                 found->ts = tmp->ts;
 770         } else {
 771                 struct cfg80211_internal_bss *new;
 772                 struct cfg80211_internal_bss *hidden;
 773                 struct cfg80211_bss_ies *ies;
 774
 775                 /*
 776                  * create a copy -- the "res" variable that is passed in
 777                  * is allocated on the stack since it's not needed in the
 778                  * more common case of an update
 779                  */
 780                 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
 781                               GFP_ATOMIC);
 782                 if (!new) {
 783                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 784                         if (ies)
 785                                 kfree_rcu(ies, rcu_head);
 786                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 787                         if (ies)
 788                                 kfree_rcu(ies, rcu_head);
 789                         goto drop;
 790                 }
 791                 memcpy(new, tmp, sizeof(*new));
 792                 new->refcount = 1;
 793                 INIT_LIST_HEAD(&new->hidden_list);
 794
 795                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 796                         hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
 797                         if (!hidden)
 798                                 hidden = rb_find_bss(dev, tmp,
 799                                                      BSS_CMP_HIDE_NUL);
 800                         if (hidden) {
 801                                 new->pub.hidden_beacon_bss = &hidden->pub;
 802                                 list_add(&new->hidden_list,
 803                                          &hidden->hidden_list);
 804                                 hidden->refcount++;
 805                                 rcu_assign_pointer(new->pub.beacon_ies,
 806                                                    hidden->pub.beacon_ies);
 807                         }
 808                 } else {
 809                         /*
 810                          * Ok so we found a beacon, and don't have an entry. If
 811                          * it's a beacon with hidden SSID, we might be in for an
 812                          * expensive search for any probe responses that should
 813                          * be grouped with this beacon for updates ...
 814                          */
 815                         if (!cfg80211_combine_bsses(dev, new)) {
 816                                 kfree(new);
 817                                 goto drop;
 818                         }
 819                 }
 820
 821                 list_add_tail(&new->list, &dev->bss_list);
 822                 rb_insert_bss(dev, new);
 823                 found = new;
 824         }
 825
 826         dev->bss_generation++;
 827         bss_ref_get(dev, found);
 828         spin_unlock_bh(&dev->bss_lock);
 829
 830         return found;
 831  drop:
 832         spin_unlock_bh(&dev->bss_lock);
 833         return NULL;
 834 }
 835
 836 static struct ieee80211_channel *
 837 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 838                          struct ieee80211_channel *channel)
 839 {
 840         const u8 *tmp;
 841         u32 freq;
 842         int channel_number = -1;
 843
 844         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 845         if (tmp && tmp[1] == 1) {
 846                 channel_number = tmp[2];
 847         } else {
 848                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 849                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 850                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 851
 852                         channel_number = htop->primary_chan;
 853                 }
 854         }
 855
 856         if (channel_number < 0)
 857                 return channel;
 858
 859         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 860         channel = ieee80211_get_channel(wiphy, freq);
 861         if (!channel)
 862                 return NULL;
 863         if (channel->flags & IEEE80211_CHAN_DISABLED)
 864                 return NULL;
 865         return channel;
 866 }
 867
 868 struct cfg80211_bss*
 869 cfg80211_inform_bss(struct wiphy *wiphy,
 870                     struct ieee80211_channel *channel,
 871                     const u8 *bssid, u64 tsf, u16 capability,
 872                     u16 beacon_interval, const u8 *ie, size_t ielen,
 873                     s32 signal, gfp_t gfp)
 874 {
 875         struct cfg80211_bss_ies *ies;
 876         struct cfg80211_internal_bss tmp = {}, *res;
 877
 878         if (WARN_ON(!wiphy))
 879                 return NULL;
 880
 881         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 882                         (signal < 0 || signal > 100)))
 883                 return NULL;
 884
 885         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
 886         if (!channel)
 887                 return NULL;
 888
 889         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 890         tmp.pub.channel = channel;
 891         tmp.pub.signal = signal;
 892         tmp.pub.beacon_interval = beacon_interval;
 893         tmp.pub.capability = capability;
 894         /*
 895          * Since we do not know here whether the IEs are from a Beacon or Probe
 896          * Response frame, we need to pick one of the options and only use it
 897          * with the driver that does not provide the full Beacon/Probe Response
 898          * frame. Use Beacon frame pointer to avoid indicating that this should
 899          * override the IEs pointer should we have received an earlier
 900          * indication of Probe Response data.
 901          */
 902         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 903         if (!ies)
 904                 return NULL;
 905         ies->len = ielen;
 906         ies->tsf = tsf;
 907         memcpy(ies->data, ie, ielen);
 908
 909         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 910         rcu_assign_pointer(tmp.pub.ies, ies);
 911
 912         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 913         if (!res)
 914                 return NULL;
 915
 916         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 917                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 918
 919         trace_cfg80211_return_bss(&res->pub);
 920         /* cfg80211_bss_update gives us a referenced result */
 921         return &res->pub;
 922 }
 923 EXPORT_SYMBOL(cfg80211_inform_bss);
 924
 925 struct cfg80211_bss *
 926 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 927                           struct ieee80211_channel *channel,
 928                           struct ieee80211_mgmt *mgmt, size_t len,
 929                           s32 signal, gfp_t gfp)
 930 {
 931         struct cfg80211_internal_bss tmp = {}, *res;
 932         struct cfg80211_bss_ies *ies;
 933         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 934                                       u.probe_resp.variable);
 935
 936         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 937                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 938
 939         trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal);
 940
 941         if (WARN_ON(!mgmt))
 942                 return NULL;
 943
 944         if (WARN_ON(!wiphy))
 945                 return NULL;
 946
 947         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 948                     (signal < 0 || signal > 100)))
 949                 return NULL;
 950
 951         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 952                 return NULL;
 953
 954         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 955                                            ielen, channel);
 956         if (!channel)
 957                 return NULL;
 958
 959         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 960         if (!ies)
 961                 return NULL;
 962         ies->len = ielen;
 963         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 964         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 965
 966         if (ieee80211_is_probe_resp(mgmt->frame_control))
 967                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 968         else
 969                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 970         rcu_assign_pointer(tmp.pub.ies, ies);
 971
 972         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 973         tmp.pub.channel = channel;
 974         tmp.pub.signal = signal;
 975         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 976         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 977
 978         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 979         if (!res)
 980                 return NULL;
 981
 982         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 983                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 984
 985         trace_cfg80211_return_bss(&res->pub);
 986         /* cfg80211_bss_update gives us a referenced result */
 987         return &res->pub;
 988 }
 989 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 990
 991 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 992 {
 993         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 994         struct cfg80211_internal_bss *bss;
 995
 996         if (!pub)
 997                 return;
 998
 999         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1000
1001         spin_lock_bh(&dev->bss_lock);
1002         bss_ref_get(dev, bss);
1003         spin_unlock_bh(&dev->bss_lock);
1004 }
1005 EXPORT_SYMBOL(cfg80211_ref_bss);
1006
1007 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1008 {
1009         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1010         struct cfg80211_internal_bss *bss;
1011
1012         if (!pub)
1013                 return;
1014
1015         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1016
1017         spin_lock_bh(&dev->bss_lock);
1018         bss_ref_put(dev, bss);
1019         spin_unlock_bh(&dev->bss_lock);
1020 }
1021 EXPORT_SYMBOL(cfg80211_put_bss);
1022
1023 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1024 {
1025         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1026         struct cfg80211_internal_bss *bss;
1027
1028         if (WARN_ON(!pub))
1029                 return;
1030
1031         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1032
1033         spin_lock_bh(&dev->bss_lock);
1034         if (!list_empty(&bss->list)) {
1035                 if (__cfg80211_unlink_bss(dev, bss))
1036                         dev->bss_generation++;
1037         }
1038         spin_unlock_bh(&dev->bss_lock);
1039 }
1040 EXPORT_SYMBOL(cfg80211_unlink_bss);
1041
1042 #ifdef CONFIG_CFG80211_WEXT
1043 int cfg80211_wext_siwscan(struct net_device *dev,
1044                           struct iw_request_info *info,
1045                           union iwreq_data *wrqu, char *extra)
1046 {
1047         struct cfg80211_registered_device *rdev;
1048         struct wiphy *wiphy;
1049         struct iw_scan_req *wreq = NULL;
1050         struct cfg80211_scan_request *creq = NULL;
1051         int i, err, n_channels = 0;
1052         enum ieee80211_band band;
1053
1054         if (!netif_running(dev))
1055                 return -ENETDOWN;
1056
1057         if (wrqu->data.length == sizeof(struct iw_scan_req))
1058                 wreq = (struct iw_scan_req *)extra;
1059
1060         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1061
1062         if (IS_ERR(rdev))
1063                 return PTR_ERR(rdev);
1064
1065         mutex_lock(&rdev->sched_scan_mtx);
1066         if (rdev->scan_req) {
1067                 err = -EBUSY;
1068                 goto out;
1069         }
1070
1071         wiphy = &rdev->wiphy;
1072
1073         /* Determine number of channels, needed to allocate creq */
1074         if (wreq && wreq->num_channels)
1075                 n_channels = wreq->num_channels;
1076         else {
1077                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1078                         if (wiphy->bands[band])
1079                                 n_channels += wiphy->bands[band]->n_channels;
1080         }
1081
1082         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1083                        n_channels * sizeof(void *),
1084                        GFP_ATOMIC);
1085         if (!creq) {
1086                 err = -ENOMEM;
1087                 goto out;
1088         }
1089
1090         creq->wiphy = wiphy;
1091         creq->wdev = dev->ieee80211_ptr;
1092         /* SSIDs come after channels */
1093         creq->ssids = (void *)&creq->channels[n_channels];
1094         creq->n_channels = n_channels;
1095         creq->n_ssids = 1;
1096         creq->scan_start = jiffies;
1097
1098         /* translate "Scan on frequencies" request */
1099         i = 0;
1100         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1101                 int j;
1102
1103                 if (!wiphy->bands[band])
1104                         continue;
1105
1106                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1107                         /* ignore disabled channels */
1108                         if (wiphy->bands[band]->channels[j].flags &
1109                                                 IEEE80211_CHAN_DISABLED)
1110                                 continue;
1111
1112                         /* If we have a wireless request structure and the
1113                          * wireless request specifies frequencies, then search
1114                          * for the matching hardware channel.
1115                          */
1116                         if (wreq && wreq->num_channels) {
1117                                 int k;
1118                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1119                                 for (k = 0; k < wreq->num_channels; k++) {
1120                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1121                                         if (wext_freq == wiphy_freq)
1122                                                 goto wext_freq_found;
1123                                 }
1124                                 goto wext_freq_not_found;
1125                         }
1126
1127                 wext_freq_found:
1128                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1129                         i++;
1130                 wext_freq_not_found: ;
1131                 }
1132         }
1133         /* No channels found? */
1134         if (!i) {
1135                 err = -EINVAL;
1136                 goto out;
1137         }
1138
1139         /* Set real number of channels specified in creq->channels[] */
1140         creq->n_channels = i;
1141
1142         /* translate "Scan for SSID" request */
1143         if (wreq) {
1144                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1145                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1146                                 err = -EINVAL;
1147                                 goto out;
1148                         }
1149                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1150                         creq->ssids[0].ssid_len = wreq->essid_len;
1151                 }
1152                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1153                         creq->n_ssids = 0;
1154         }
1155
1156         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1157                 if (wiphy->bands[i])
1158                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1159
1160         rdev->scan_req = creq;
1161         err = rdev_scan(rdev, creq);
1162         if (err) {
1163                 rdev->scan_req = NULL;
1164                 /* creq will be freed below */
1165         } else {
1166                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1167                 /* creq now owned by driver */
1168                 creq = NULL;
1169                 dev_hold(dev);
1170         }
1171  out:
1172         mutex_unlock(&rdev->sched_scan_mtx);
1173         kfree(creq);
1174         cfg80211_unlock_rdev(rdev);
1175         return err;
1176 }
1177 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1178
1179 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1180                                    const struct cfg80211_bss_ies *ies,
1181                                    char **current_ev, char *end_buf)
1182 {
1183         const u8 *pos, *end, *next;
1184         struct iw_event iwe;
1185
1186         if (!ies)
1187                 return;
1188
1189         /*
1190          * If needed, fragment the IEs buffer (at IE boundaries) into short
1191          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1192          */
1193         pos = ies->data;
1194         end = pos + ies->len;
1195
1196         while (end - pos > IW_GENERIC_IE_MAX) {
1197                 next = pos + 2 + pos[1];
1198                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1199                         next = next + 2 + next[1];
1200
1201                 memset(&iwe, 0, sizeof(iwe));
1202                 iwe.cmd = IWEVGENIE;
1203                 iwe.u.data.length = next - pos;
1204                 *current_ev = iwe_stream_add_point(info, *current_ev,
1205                                                    end_buf, &iwe,
1206                                                    (void *)pos);
1207
1208                 pos = next;
1209         }
1210
1211         if (end > pos) {
1212                 memset(&iwe, 0, sizeof(iwe));
1213                 iwe.cmd = IWEVGENIE;
1214                 iwe.u.data.length = end - pos;
1215                 *current_ev = iwe_stream_add_point(info, *current_ev,
1216                                                    end_buf, &iwe,
1217                                                    (void *)pos);
1218         }
1219 }
1220
1221 static char *
1222 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1223               struct cfg80211_internal_bss *bss, char *current_ev,
1224               char *end_buf)
1225 {
1226         const struct cfg80211_bss_ies *ies;
1227         struct iw_event iwe;
1228         const u8 *ie;
1229         u8 *buf, *cfg, *p;
1230         int rem, i, sig;
1231         bool ismesh = false;
1232
1233         memset(&iwe, 0, sizeof(iwe));
1234         iwe.cmd = SIOCGIWAP;
1235         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1236         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1237         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1238                                           IW_EV_ADDR_LEN);
1239
1240         memset(&iwe, 0, sizeof(iwe));
1241         iwe.cmd = SIOCGIWFREQ;
1242         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1243         iwe.u.freq.e = 0;
1244         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1245                                           IW_EV_FREQ_LEN);
1246
1247         memset(&iwe, 0, sizeof(iwe));
1248         iwe.cmd = SIOCGIWFREQ;
1249         iwe.u.freq.m = bss->pub.channel->center_freq;
1250         iwe.u.freq.e = 6;
1251         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1252                                           IW_EV_FREQ_LEN);
1253
1254         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1255                 memset(&iwe, 0, sizeof(iwe));
1256                 iwe.cmd = IWEVQUAL;
1257                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1258                                      IW_QUAL_NOISE_INVALID |
1259                                      IW_QUAL_QUAL_UPDATED;
1260                 switch (wiphy->signal_type) {
1261                 case CFG80211_SIGNAL_TYPE_MBM:
1262                         sig = bss->pub.signal / 100;
1263                         iwe.u.qual.level = sig;
1264                         iwe.u.qual.updated |= IW_QUAL_DBM;
1265                         if (sig < -110)         /* rather bad */
1266                                 sig = -110;
1267                         else if (sig > -40)     /* perfect */
1268                                 sig = -40;
1269                         /* will give a range of 0 .. 70 */
1270                         iwe.u.qual.qual = sig + 110;
1271                         break;
1272                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1273                         iwe.u.qual.level = bss->pub.signal;
1274                         /* will give range 0 .. 100 */
1275                         iwe.u.qual.qual = bss->pub.signal;
1276                         break;
1277                 default:
1278                         /* not reached */
1279                         break;
1280                 }
1281                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1282                                                   &iwe, IW_EV_QUAL_LEN);
1283         }
1284
1285         memset(&iwe, 0, sizeof(iwe));
1286         iwe.cmd = SIOCGIWENCODE;
1287         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1288                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1289         else
1290                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1291         iwe.u.data.length = 0;
1292         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1293                                           &iwe, "");
1294
1295         rcu_read_lock();
1296         ies = rcu_dereference(bss->pub.ies);
1297         rem = ies->len;
1298         ie = ies->data;
1299
1300         while (rem >= 2) {
1301                 /* invalid data */
1302                 if (ie[1] > rem - 2)
1303                         break;
1304
1305                 switch (ie[0]) {
1306                 case WLAN_EID_SSID:
1307                         memset(&iwe, 0, sizeof(iwe));
1308                         iwe.cmd = SIOCGIWESSID;
1309                         iwe.u.data.length = ie[1];
1310                         iwe.u.data.flags = 1;
1311                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1312                                                           &iwe, (u8 *)ie + 2);
1313                         break;
1314                 case WLAN_EID_MESH_ID:
1315                         memset(&iwe, 0, sizeof(iwe));
1316                         iwe.cmd = SIOCGIWESSID;
1317                         iwe.u.data.length = ie[1];
1318                         iwe.u.data.flags = 1;
1319                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1320                                                           &iwe, (u8 *)ie + 2);
1321                         break;
1322                 case WLAN_EID_MESH_CONFIG:
1323                         ismesh = true;
1324                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1325                                 break;
1326                         buf = kmalloc(50, GFP_ATOMIC);
1327                         if (!buf)
1328                                 break;
1329                         cfg = (u8 *)ie + 2;
1330                         memset(&iwe, 0, sizeof(iwe));
1331                         iwe.cmd = IWEVCUSTOM;
1332                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1333                                 "0x%02X", cfg[0]);
1334                         iwe.u.data.length = strlen(buf);
1335                         current_ev = iwe_stream_add_point(info, current_ev,
1336                                                           end_buf,
1337                                                           &iwe, buf);
1338                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1339                                 cfg[1]);
1340                         iwe.u.data.length = strlen(buf);
1341                         current_ev = iwe_stream_add_point(info, current_ev,
1342                                                           end_buf,
1343                                                           &iwe, buf);
1344                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1345                                 cfg[2]);
1346                         iwe.u.data.length = strlen(buf);
1347                         current_ev = iwe_stream_add_point(info, current_ev,
1348                                                           end_buf,
1349                                                           &iwe, buf);
1350                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1351                         iwe.u.data.length = strlen(buf);
1352                         current_ev = iwe_stream_add_point(info, current_ev,
1353                                                           end_buf,
1354                                                           &iwe, buf);
1355                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1356                         iwe.u.data.length = strlen(buf);
1357                         current_ev = iwe_stream_add_point(info, current_ev,
1358                                                           end_buf,
1359                                                           &iwe, buf);
1360                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1361                         iwe.u.data.length = strlen(buf);
1362                         current_ev = iwe_stream_add_point(info, current_ev,
1363                                                           end_buf,
1364                                                           &iwe, buf);
1365                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1366                         iwe.u.data.length = strlen(buf);
1367                         current_ev = iwe_stream_add_point(info, current_ev,
1368                                                           end_buf,
1369                                                           &iwe, buf);
1370                         kfree(buf);
1371                         break;
1372                 case WLAN_EID_SUPP_RATES:
1373                 case WLAN_EID_EXT_SUPP_RATES:
1374                         /* display all supported rates in readable format */
1375                         p = current_ev + iwe_stream_lcp_len(info);
1376
1377                         memset(&iwe, 0, sizeof(iwe));
1378                         iwe.cmd = SIOCGIWRATE;
1379                         /* Those two flags are ignored... */
1380                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1381
1382                         for (i = 0; i < ie[1]; i++) {
1383                                 iwe.u.bitrate.value =
1384                                         ((ie[i + 2] & 0x7f) * 500000);
1385                                 p = iwe_stream_add_value(info, current_ev, p,
1386                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1387                         }
1388                         current_ev = p;
1389                         break;
1390                 }
1391                 rem -= ie[1] + 2;
1392                 ie += ie[1] + 2;
1393         }
1394
1395         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1396             ismesh) {
1397                 memset(&iwe, 0, sizeof(iwe));
1398                 iwe.cmd = SIOCGIWMODE;
1399                 if (ismesh)
1400                         iwe.u.mode = IW_MODE_MESH;
1401                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1402                         iwe.u.mode = IW_MODE_MASTER;
1403                 else
1404                         iwe.u.mode = IW_MODE_ADHOC;
1405                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1406                                                   &iwe, IW_EV_UINT_LEN);
1407         }
1408
1409         buf = kmalloc(31, GFP_ATOMIC);
1410         if (buf) {
1411                 memset(&iwe, 0, sizeof(iwe));
1412                 iwe.cmd = IWEVCUSTOM;
1413                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1414                 iwe.u.data.length = strlen(buf);
1415                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1416                                                   &iwe, buf);
1417                 memset(&iwe, 0, sizeof(iwe));
1418                 iwe.cmd = IWEVCUSTOM;
1419                 sprintf(buf, " Last beacon: %ums ago",
1420                         elapsed_jiffies_msecs(bss->ts));
1421                 iwe.u.data.length = strlen(buf);
1422                 current_ev = iwe_stream_add_point(info, current_ev,
1423                                                   end_buf, &iwe, buf);
1424                 kfree(buf);
1425         }
1426
1427         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1428         rcu_read_unlock();
1429
1430         return current_ev;
1431 }
1432
1433
1434 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1435                                   struct iw_request_info *info,
1436                                   char *buf, size_t len)
1437 {
1438         char *current_ev = buf;
1439         char *end_buf = buf + len;
1440         struct cfg80211_internal_bss *bss;
1441
1442         spin_lock_bh(&dev->bss_lock);
1443         cfg80211_bss_expire(dev);
1444
1445         list_for_each_entry(bss, &dev->bss_list, list) {
1446                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1447                         spin_unlock_bh(&dev->bss_lock);
1448                         return -E2BIG;
1449                 }
1450                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1451                                            current_ev, end_buf);
1452         }
1453         spin_unlock_bh(&dev->bss_lock);
1454         return current_ev - buf;
1455 }
1456
1457
1458 int cfg80211_wext_giwscan(struct net_device *dev,
1459                           struct iw_request_info *info,
1460                           struct iw_point *data, char *extra)
1461 {
1462         struct cfg80211_registered_device *rdev;
1463         int res;
1464
1465         if (!netif_running(dev))
1466                 return -ENETDOWN;
1467
1468         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1469
1470         if (IS_ERR(rdev))
1471                 return PTR_ERR(rdev);
1472
1473         if (rdev->scan_req) {
1474                 res = -EAGAIN;
1475                 goto out;
1476         }
1477
1478         res = ieee80211_scan_results(rdev, info, extra, data->length);
1479         data->length = 0;
1480         if (res >= 0) {
1481                 data->length = res;
1482                 res = 0;
1483         }
1484
1485  out:
1486         cfg80211_unlock_rdev(rdev);
1487         return res;
1488 }
1489 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1490 #endif