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_RDEV_LOCK(rdev);
 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         cfg80211_lock_rdev(rdev);
 234         ___cfg80211_scan_done(rdev, false);
 235         cfg80211_unlock_rdev(rdev);
 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         request = rdev->sched_scan_req;
 257
 258         mutex_lock(&rdev->sched_scan_mtx);
 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                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 702                 found->pub.signal = tmp->pub.signal;
 703                 found->pub.capability = tmp->pub.capability;
 704                 found->ts = tmp->ts;
 705
 706                 /* Update IEs */
 707                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 708                         const struct cfg80211_bss_ies *old;
 709
 710                         old = rcu_access_pointer(found->pub.proberesp_ies);
 711
 712                         rcu_assign_pointer(found->pub.proberesp_ies,
 713                                            tmp->pub.proberesp_ies);
 714                         /* Override possible earlier Beacon frame IEs */
 715                         rcu_assign_pointer(found->pub.ies,
 716                                            tmp->pub.proberesp_ies);
 717                         if (old)
 718                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 719                                           rcu_head);
 720                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 721                         const struct cfg80211_bss_ies *old;
 722                         struct cfg80211_internal_bss *bss;
 723
 724                         if (found->pub.hidden_beacon_bss &&
 725                             !list_empty(&found->hidden_list)) {
 726                                 /*
 727                                  * The found BSS struct is one of the probe
 728                                  * response members of a group, but we're
 729                                  * receiving a beacon (beacon_ies in the tmp
 730                                  * bss is used). This can only mean that the
 731                                  * AP changed its beacon from not having an
 732                                  * SSID to showing it, which is confusing so
 733                                  * drop this information.
 734                                  */
 735                                 goto drop;
 736                         }
 737
 738                         old = rcu_access_pointer(found->pub.beacon_ies);
 739
 740                         rcu_assign_pointer(found->pub.beacon_ies,
 741                                            tmp->pub.beacon_ies);
 742
 743                         /* Override IEs if they were from a beacon before */
 744                         if (old == rcu_access_pointer(found->pub.ies))
 745                                 rcu_assign_pointer(found->pub.ies,
 746                                                    tmp->pub.beacon_ies);
 747
 748                         /* Assign beacon IEs to all sub entries */
 749                         list_for_each_entry(bss, &found->hidden_list,
 750                                             hidden_list) {
 751                                 const struct cfg80211_bss_ies *ies;
 752
 753                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 754                                 WARN_ON(ies != old);
 755
 756                                 rcu_assign_pointer(bss->pub.beacon_ies,
 757                                                    tmp->pub.beacon_ies);
 758                         }
 759
 760                         if (old)
 761                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 762                                           rcu_head);
 763                 }
 764         } else {
 765                 struct cfg80211_internal_bss *new;
 766                 struct cfg80211_internal_bss *hidden;
 767                 struct cfg80211_bss_ies *ies;
 768
 769                 /*
 770                  * create a copy -- the "res" variable that is passed in
 771                  * is allocated on the stack since it's not needed in the
 772                  * more common case of an update
 773                  */
 774                 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
 775                               GFP_ATOMIC);
 776                 if (!new) {
 777                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 778                         if (ies)
 779                                 kfree_rcu(ies, rcu_head);
 780                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 781                         if (ies)
 782                                 kfree_rcu(ies, rcu_head);
 783                         goto drop;
 784                 }
 785                 memcpy(new, tmp, sizeof(*new));
 786                 new->refcount = 1;
 787                 INIT_LIST_HEAD(&new->hidden_list);
 788
 789                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 790                         hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
 791                         if (!hidden)
 792                                 hidden = rb_find_bss(dev, tmp,
 793                                                      BSS_CMP_HIDE_NUL);
 794                         if (hidden) {
 795                                 new->pub.hidden_beacon_bss = &hidden->pub;
 796                                 list_add(&new->hidden_list,
 797                                          &hidden->hidden_list);
 798                                 hidden->refcount++;
 799                                 rcu_assign_pointer(new->pub.beacon_ies,
 800                                                    hidden->pub.beacon_ies);
 801                         }
 802                 } else {
 803                         /*
 804                          * Ok so we found a beacon, and don't have an entry. If
 805                          * it's a beacon with hidden SSID, we might be in for an
 806                          * expensive search for any probe responses that should
 807                          * be grouped with this beacon for updates ...
 808                          */
 809                         if (!cfg80211_combine_bsses(dev, new)) {
 810                                 kfree(new);
 811                                 goto drop;
 812                         }
 813                 }
 814
 815                 list_add_tail(&new->list, &dev->bss_list);
 816                 rb_insert_bss(dev, new);
 817                 found = new;
 818         }
 819
 820         dev->bss_generation++;
 821         bss_ref_get(dev, found);
 822         spin_unlock_bh(&dev->bss_lock);
 823
 824         return found;
 825  drop:
 826         spin_unlock_bh(&dev->bss_lock);
 827         return NULL;
 828 }
 829
 830 static struct ieee80211_channel *
 831 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 832                          struct ieee80211_channel *channel)
 833 {
 834         const u8 *tmp;
 835         u32 freq;
 836         int channel_number = -1;
 837
 838         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 839         if (tmp && tmp[1] == 1) {
 840                 channel_number = tmp[2];
 841         } else {
 842                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 843                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 844                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 845
 846                         channel_number = htop->primary_chan;
 847                 }
 848         }
 849
 850         if (channel_number < 0)
 851                 return channel;
 852
 853         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 854         channel = ieee80211_get_channel(wiphy, freq);
 855         if (!channel)
 856                 return NULL;
 857         if (channel->flags & IEEE80211_CHAN_DISABLED)
 858                 return NULL;
 859         return channel;
 860 }
 861
 862 struct cfg80211_bss*
 863 cfg80211_inform_bss(struct wiphy *wiphy,
 864                     struct ieee80211_channel *channel,
 865                     const u8 *bssid, u64 tsf, u16 capability,
 866                     u16 beacon_interval, const u8 *ie, size_t ielen,
 867                     s32 signal, gfp_t gfp)
 868 {
 869         struct cfg80211_bss_ies *ies;
 870         struct cfg80211_internal_bss tmp = {}, *res;
 871
 872         if (WARN_ON(!wiphy))
 873                 return NULL;
 874
 875         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 876                         (signal < 0 || signal > 100)))
 877                 return NULL;
 878
 879         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
 880         if (!channel)
 881                 return NULL;
 882
 883         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 884         tmp.pub.channel = channel;
 885         tmp.pub.signal = signal;
 886         tmp.pub.beacon_interval = beacon_interval;
 887         tmp.pub.capability = capability;
 888         /*
 889          * Since we do not know here whether the IEs are from a Beacon or Probe
 890          * Response frame, we need to pick one of the options and only use it
 891          * with the driver that does not provide the full Beacon/Probe Response
 892          * frame. Use Beacon frame pointer to avoid indicating that this should
 893          * override the IEs pointer should we have received an earlier
 894          * indication of Probe Response data.
 895          */
 896         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 897         if (!ies)
 898                 return NULL;
 899         ies->len = ielen;
 900         ies->tsf = tsf;
 901         memcpy(ies->data, ie, ielen);
 902
 903         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 904         rcu_assign_pointer(tmp.pub.ies, ies);
 905
 906         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 907         if (!res)
 908                 return NULL;
 909
 910         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 911                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 912
 913         trace_cfg80211_return_bss(&res->pub);
 914         /* cfg80211_bss_update gives us a referenced result */
 915         return &res->pub;
 916 }
 917 EXPORT_SYMBOL(cfg80211_inform_bss);
 918
 919 struct cfg80211_bss *
 920 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 921                           struct ieee80211_channel *channel,
 922                           struct ieee80211_mgmt *mgmt, size_t len,
 923                           s32 signal, gfp_t gfp)
 924 {
 925         struct cfg80211_internal_bss tmp = {}, *res;
 926         struct cfg80211_bss_ies *ies;
 927         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 928                                       u.probe_resp.variable);
 929
 930         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 931                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 932
 933         trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal);
 934
 935         if (WARN_ON(!mgmt))
 936                 return NULL;
 937
 938         if (WARN_ON(!wiphy))
 939                 return NULL;
 940
 941         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 942                     (signal < 0 || signal > 100)))
 943                 return NULL;
 944
 945         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 946                 return NULL;
 947
 948         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 949                                            ielen, channel);
 950         if (!channel)
 951                 return NULL;
 952
 953         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 954         if (!ies)
 955                 return NULL;
 956         ies->len = ielen;
 957         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 958         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 959
 960         if (ieee80211_is_probe_resp(mgmt->frame_control))
 961                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 962         else
 963                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 964         rcu_assign_pointer(tmp.pub.ies, ies);
 965
 966         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 967         tmp.pub.channel = channel;
 968         tmp.pub.signal = signal;
 969         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 970         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 971
 972         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 973         if (!res)
 974                 return NULL;
 975
 976         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 977                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 978
 979         trace_cfg80211_return_bss(&res->pub);
 980         /* cfg80211_bss_update gives us a referenced result */
 981         return &res->pub;
 982 }
 983 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 984
 985 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 986 {
 987         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 988         struct cfg80211_internal_bss *bss;
 989
 990         if (!pub)
 991                 return;
 992
 993         bss = container_of(pub, struct cfg80211_internal_bss, pub);
 994
 995         spin_lock_bh(&dev->bss_lock);
 996         bss_ref_get(dev, bss);
 997         spin_unlock_bh(&dev->bss_lock);
 998 }
 999 EXPORT_SYMBOL(cfg80211_ref_bss);
1000
1001 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1002 {
1003         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1004         struct cfg80211_internal_bss *bss;
1005
1006         if (!pub)
1007                 return;
1008
1009         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1010
1011         spin_lock_bh(&dev->bss_lock);
1012         bss_ref_put(dev, bss);
1013         spin_unlock_bh(&dev->bss_lock);
1014 }
1015 EXPORT_SYMBOL(cfg80211_put_bss);
1016
1017 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1018 {
1019         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1020         struct cfg80211_internal_bss *bss;
1021
1022         if (WARN_ON(!pub))
1023                 return;
1024
1025         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1026
1027         spin_lock_bh(&dev->bss_lock);
1028         if (!list_empty(&bss->list)) {
1029                 if (__cfg80211_unlink_bss(dev, bss))
1030                         dev->bss_generation++;
1031         }
1032         spin_unlock_bh(&dev->bss_lock);
1033 }
1034 EXPORT_SYMBOL(cfg80211_unlink_bss);
1035
1036 #ifdef CONFIG_CFG80211_WEXT
1037 int cfg80211_wext_siwscan(struct net_device *dev,
1038                           struct iw_request_info *info,
1039                           union iwreq_data *wrqu, char *extra)
1040 {
1041         struct cfg80211_registered_device *rdev;
1042         struct wiphy *wiphy;
1043         struct iw_scan_req *wreq = NULL;
1044         struct cfg80211_scan_request *creq = NULL;
1045         int i, err, n_channels = 0;
1046         enum ieee80211_band band;
1047
1048         if (!netif_running(dev))
1049                 return -ENETDOWN;
1050
1051         if (wrqu->data.length == sizeof(struct iw_scan_req))
1052                 wreq = (struct iw_scan_req *)extra;
1053
1054         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1055
1056         if (IS_ERR(rdev))
1057                 return PTR_ERR(rdev);
1058
1059         if (rdev->scan_req) {
1060                 err = -EBUSY;
1061                 goto out;
1062         }
1063
1064         wiphy = &rdev->wiphy;
1065
1066         /* Determine number of channels, needed to allocate creq */
1067         if (wreq && wreq->num_channels)
1068                 n_channels = wreq->num_channels;
1069         else {
1070                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1071                         if (wiphy->bands[band])
1072                                 n_channels += wiphy->bands[band]->n_channels;
1073         }
1074
1075         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1076                        n_channels * sizeof(void *),
1077                        GFP_ATOMIC);
1078         if (!creq) {
1079                 err = -ENOMEM;
1080                 goto out;
1081         }
1082
1083         creq->wiphy = wiphy;
1084         creq->wdev = dev->ieee80211_ptr;
1085         /* SSIDs come after channels */
1086         creq->ssids = (void *)&creq->channels[n_channels];
1087         creq->n_channels = n_channels;
1088         creq->n_ssids = 1;
1089         creq->scan_start = jiffies;
1090
1091         /* translate "Scan on frequencies" request */
1092         i = 0;
1093         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1094                 int j;
1095
1096                 if (!wiphy->bands[band])
1097                         continue;
1098
1099                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1100                         /* ignore disabled channels */
1101                         if (wiphy->bands[band]->channels[j].flags &
1102                                                 IEEE80211_CHAN_DISABLED)
1103                                 continue;
1104
1105                         /* If we have a wireless request structure and the
1106                          * wireless request specifies frequencies, then search
1107                          * for the matching hardware channel.
1108                          */
1109                         if (wreq && wreq->num_channels) {
1110                                 int k;
1111                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1112                                 for (k = 0; k < wreq->num_channels; k++) {
1113                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1114                                         if (wext_freq == wiphy_freq)
1115                                                 goto wext_freq_found;
1116                                 }
1117                                 goto wext_freq_not_found;
1118                         }
1119
1120                 wext_freq_found:
1121                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1122                         i++;
1123                 wext_freq_not_found: ;
1124                 }
1125         }
1126         /* No channels found? */
1127         if (!i) {
1128                 err = -EINVAL;
1129                 goto out;
1130         }
1131
1132         /* Set real number of channels specified in creq->channels[] */
1133         creq->n_channels = i;
1134
1135         /* translate "Scan for SSID" request */
1136         if (wreq) {
1137                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1138                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1139                                 err = -EINVAL;
1140                                 goto out;
1141                         }
1142                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1143                         creq->ssids[0].ssid_len = wreq->essid_len;
1144                 }
1145                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1146                         creq->n_ssids = 0;
1147         }
1148
1149         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1150                 if (wiphy->bands[i])
1151                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1152
1153         rdev->scan_req = creq;
1154         err = rdev_scan(rdev, creq);
1155         if (err) {
1156                 rdev->scan_req = NULL;
1157                 /* creq will be freed below */
1158         } else {
1159                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1160                 /* creq now owned by driver */
1161                 creq = NULL;
1162                 dev_hold(dev);
1163         }
1164  out:
1165         kfree(creq);
1166         cfg80211_unlock_rdev(rdev);
1167         return err;
1168 }
1169 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1170
1171 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1172                                    const struct cfg80211_bss_ies *ies,
1173                                    char **current_ev, char *end_buf)
1174 {
1175         const u8 *pos, *end, *next;
1176         struct iw_event iwe;
1177
1178         if (!ies)
1179                 return;
1180
1181         /*
1182          * If needed, fragment the IEs buffer (at IE boundaries) into short
1183          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1184          */
1185         pos = ies->data;
1186         end = pos + ies->len;
1187
1188         while (end - pos > IW_GENERIC_IE_MAX) {
1189                 next = pos + 2 + pos[1];
1190                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1191                         next = next + 2 + next[1];
1192
1193                 memset(&iwe, 0, sizeof(iwe));
1194                 iwe.cmd = IWEVGENIE;
1195                 iwe.u.data.length = next - pos;
1196                 *current_ev = iwe_stream_add_point(info, *current_ev,
1197                                                    end_buf, &iwe,
1198                                                    (void *)pos);
1199
1200                 pos = next;
1201         }
1202
1203         if (end > pos) {
1204                 memset(&iwe, 0, sizeof(iwe));
1205                 iwe.cmd = IWEVGENIE;
1206                 iwe.u.data.length = end - pos;
1207                 *current_ev = iwe_stream_add_point(info, *current_ev,
1208                                                    end_buf, &iwe,
1209                                                    (void *)pos);
1210         }
1211 }
1212
1213 static char *
1214 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1215               struct cfg80211_internal_bss *bss, char *current_ev,
1216               char *end_buf)
1217 {
1218         const struct cfg80211_bss_ies *ies;
1219         struct iw_event iwe;
1220         const u8 *ie;
1221         u8 *buf, *cfg, *p;
1222         int rem, i, sig;
1223         bool ismesh = false;
1224
1225         memset(&iwe, 0, sizeof(iwe));
1226         iwe.cmd = SIOCGIWAP;
1227         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1228         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1229         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1230                                           IW_EV_ADDR_LEN);
1231
1232         memset(&iwe, 0, sizeof(iwe));
1233         iwe.cmd = SIOCGIWFREQ;
1234         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1235         iwe.u.freq.e = 0;
1236         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1237                                           IW_EV_FREQ_LEN);
1238
1239         memset(&iwe, 0, sizeof(iwe));
1240         iwe.cmd = SIOCGIWFREQ;
1241         iwe.u.freq.m = bss->pub.channel->center_freq;
1242         iwe.u.freq.e = 6;
1243         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1244                                           IW_EV_FREQ_LEN);
1245
1246         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1247                 memset(&iwe, 0, sizeof(iwe));
1248                 iwe.cmd = IWEVQUAL;
1249                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1250                                      IW_QUAL_NOISE_INVALID |
1251                                      IW_QUAL_QUAL_UPDATED;
1252                 switch (wiphy->signal_type) {
1253                 case CFG80211_SIGNAL_TYPE_MBM:
1254                         sig = bss->pub.signal / 100;
1255                         iwe.u.qual.level = sig;
1256                         iwe.u.qual.updated |= IW_QUAL_DBM;
1257                         if (sig < -110)         /* rather bad */
1258                                 sig = -110;
1259                         else if (sig > -40)     /* perfect */
1260                                 sig = -40;
1261                         /* will give a range of 0 .. 70 */
1262                         iwe.u.qual.qual = sig + 110;
1263                         break;
1264                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1265                         iwe.u.qual.level = bss->pub.signal;
1266                         /* will give range 0 .. 100 */
1267                         iwe.u.qual.qual = bss->pub.signal;
1268                         break;
1269                 default:
1270                         /* not reached */
1271                         break;
1272                 }
1273                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1274                                                   &iwe, IW_EV_QUAL_LEN);
1275         }
1276
1277         memset(&iwe, 0, sizeof(iwe));
1278         iwe.cmd = SIOCGIWENCODE;
1279         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1280                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1281         else
1282                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1283         iwe.u.data.length = 0;
1284         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1285                                           &iwe, "");
1286
1287         rcu_read_lock();
1288         ies = rcu_dereference(bss->pub.ies);
1289         rem = ies->len;
1290         ie = ies->data;
1291
1292         while (rem >= 2) {
1293                 /* invalid data */
1294                 if (ie[1] > rem - 2)
1295                         break;
1296
1297                 switch (ie[0]) {
1298                 case WLAN_EID_SSID:
1299                         memset(&iwe, 0, sizeof(iwe));
1300                         iwe.cmd = SIOCGIWESSID;
1301                         iwe.u.data.length = ie[1];
1302                         iwe.u.data.flags = 1;
1303                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1304                                                           &iwe, (u8 *)ie + 2);
1305                         break;
1306                 case WLAN_EID_MESH_ID:
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_CONFIG:
1315                         ismesh = true;
1316                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1317                                 break;
1318                         buf = kmalloc(50, GFP_ATOMIC);
1319                         if (!buf)
1320                                 break;
1321                         cfg = (u8 *)ie + 2;
1322                         memset(&iwe, 0, sizeof(iwe));
1323                         iwe.cmd = IWEVCUSTOM;
1324                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1325                                 "0x%02X", cfg[0]);
1326                         iwe.u.data.length = strlen(buf);
1327                         current_ev = iwe_stream_add_point(info, current_ev,
1328                                                           end_buf,
1329                                                           &iwe, buf);
1330                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1331                                 cfg[1]);
1332                         iwe.u.data.length = strlen(buf);
1333                         current_ev = iwe_stream_add_point(info, current_ev,
1334                                                           end_buf,
1335                                                           &iwe, buf);
1336                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1337                                 cfg[2]);
1338                         iwe.u.data.length = strlen(buf);
1339                         current_ev = iwe_stream_add_point(info, current_ev,
1340                                                           end_buf,
1341                                                           &iwe, buf);
1342                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1343                         iwe.u.data.length = strlen(buf);
1344                         current_ev = iwe_stream_add_point(info, current_ev,
1345                                                           end_buf,
1346                                                           &iwe, buf);
1347                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1348                         iwe.u.data.length = strlen(buf);
1349                         current_ev = iwe_stream_add_point(info, current_ev,
1350                                                           end_buf,
1351                                                           &iwe, buf);
1352                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1353                         iwe.u.data.length = strlen(buf);
1354                         current_ev = iwe_stream_add_point(info, current_ev,
1355                                                           end_buf,
1356                                                           &iwe, buf);
1357                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1358                         iwe.u.data.length = strlen(buf);
1359                         current_ev = iwe_stream_add_point(info, current_ev,
1360                                                           end_buf,
1361                                                           &iwe, buf);
1362                         kfree(buf);
1363                         break;
1364                 case WLAN_EID_SUPP_RATES:
1365                 case WLAN_EID_EXT_SUPP_RATES:
1366                         /* display all supported rates in readable format */
1367                         p = current_ev + iwe_stream_lcp_len(info);
1368
1369                         memset(&iwe, 0, sizeof(iwe));
1370                         iwe.cmd = SIOCGIWRATE;
1371                         /* Those two flags are ignored... */
1372                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1373
1374                         for (i = 0; i < ie[1]; i++) {
1375                                 iwe.u.bitrate.value =
1376                                         ((ie[i + 2] & 0x7f) * 500000);
1377                                 p = iwe_stream_add_value(info, current_ev, p,
1378                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1379                         }
1380                         current_ev = p;
1381                         break;
1382                 }
1383                 rem -= ie[1] + 2;
1384                 ie += ie[1] + 2;
1385         }
1386
1387         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1388             ismesh) {
1389                 memset(&iwe, 0, sizeof(iwe));
1390                 iwe.cmd = SIOCGIWMODE;
1391                 if (ismesh)
1392                         iwe.u.mode = IW_MODE_MESH;
1393                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1394                         iwe.u.mode = IW_MODE_MASTER;
1395                 else
1396                         iwe.u.mode = IW_MODE_ADHOC;
1397                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1398                                                   &iwe, IW_EV_UINT_LEN);
1399         }
1400
1401         buf = kmalloc(31, GFP_ATOMIC);
1402         if (buf) {
1403                 memset(&iwe, 0, sizeof(iwe));
1404                 iwe.cmd = IWEVCUSTOM;
1405                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1406                 iwe.u.data.length = strlen(buf);
1407                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1408                                                   &iwe, buf);
1409                 memset(&iwe, 0, sizeof(iwe));
1410                 iwe.cmd = IWEVCUSTOM;
1411                 sprintf(buf, " Last beacon: %ums ago",
1412                         elapsed_jiffies_msecs(bss->ts));
1413                 iwe.u.data.length = strlen(buf);
1414                 current_ev = iwe_stream_add_point(info, current_ev,
1415                                                   end_buf, &iwe, buf);
1416                 kfree(buf);
1417         }
1418
1419         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1420         rcu_read_unlock();
1421
1422         return current_ev;
1423 }
1424
1425
1426 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1427                                   struct iw_request_info *info,
1428                                   char *buf, size_t len)
1429 {
1430         char *current_ev = buf;
1431         char *end_buf = buf + len;
1432         struct cfg80211_internal_bss *bss;
1433
1434         spin_lock_bh(&dev->bss_lock);
1435         cfg80211_bss_expire(dev);
1436
1437         list_for_each_entry(bss, &dev->bss_list, list) {
1438                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1439                         spin_unlock_bh(&dev->bss_lock);
1440                         return -E2BIG;
1441                 }
1442                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1443                                            current_ev, end_buf);
1444         }
1445         spin_unlock_bh(&dev->bss_lock);
1446         return current_ev - buf;
1447 }
1448
1449
1450 int cfg80211_wext_giwscan(struct net_device *dev,
1451                           struct iw_request_info *info,
1452                           struct iw_point *data, char *extra)
1453 {
1454         struct cfg80211_registered_device *rdev;
1455         int res;
1456
1457         if (!netif_running(dev))
1458                 return -ENETDOWN;
1459
1460         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1461
1462         if (IS_ERR(rdev))
1463                 return PTR_ERR(rdev);
1464
1465         if (rdev->scan_req) {
1466                 res = -EAGAIN;
1467                 goto out;
1468         }
1469
1470         res = ieee80211_scan_results(rdev, info, extra, data->length);
1471         data->length = 0;
1472         if (res >= 0) {
1473                 data->length = res;
1474                 res = 0;
1475         }
1476
1477  out:
1478         cfg80211_unlock_rdev(rdev);
1479         return res;
1480 }
1481 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1482 #endif