Pileus Git - ~andy/linux/blob - net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/slab.h>
   8 #include <linux/module.h>
   9 #include <linux/netdevice.h>
  10 #include <linux/wireless.h>
  11 #include <linux/nl80211.h>
  12 #include <linux/etherdevice.h>
  13 #include <net/arp.h>
  14 #include <net/cfg80211.h>
  15 #include <net/cfg80211-wext.h>
  16 #include <net/iw_handler.h>
  17 #include "core.h"
  18 #include "nl80211.h"
  19 #include "wext-compat.h"
  20 #include "rdev-ops.h"
  21
  22 /**
  23  * DOC: BSS tree/list structure
  24  *
  25  * At the top level, the BSS list is kept in both a list in each
  26  * registered device (@bss_list) as well as an RB-tree for faster
  27  * lookup. In the RB-tree, entries can be looked up using their
  28  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  29  * for other BSSes.
  30  *
  31  * Due to the possibility of hidden SSIDs, there's a second level
  32  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  33  * The hidden_list connects all BSSes belonging to a single AP
  34  * that has a hidden SSID, and connects beacon and probe response
  35  * entries. For a probe response entry for a hidden SSID, the
  36  * hidden_beacon_bss pointer points to the BSS struct holding the
  37  * beacon's information.
  38  *
  39  * Reference counting is done for all these references except for
  40  * the hidden_list, so that a beacon BSS struct that is otherwise
  41  * not referenced has one reference for being on the bss_list and
  42  * one for each probe response entry that points to it using the
  43  * hidden_beacon_bss pointer. When a BSS struct that has such a
  44  * pointer is get/put, the refcount update is also propagated to
  45  * the referenced struct, this ensure that it cannot get removed
  46  * while somebody is using the probe response version.
  47  *
  48  * Note that the hidden_beacon_bss pointer never changes, due to
  49  * the reference counting. Therefore, no locking is needed for
  50  * it.
  51  *
  52  * Also note that the hidden_beacon_bss pointer is only relevant
  53  * if the driver uses something other than the IEs, e.g. private
  54  * data stored stored in the BSS struct, since the beacon IEs are
  55  * also linked into the probe response struct.
  56  */
  57
  58 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  59
  60 static void bss_free(struct cfg80211_internal_bss *bss)
  61 {
  62         struct cfg80211_bss_ies *ies;
  63
  64         if (WARN_ON(atomic_read(&bss->hold)))
  65                 return;
  66
  67         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  68         if (ies && !bss->pub.hidden_beacon_bss)
  69                 kfree_rcu(ies, rcu_head);
  70         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  71         if (ies)
  72                 kfree_rcu(ies, rcu_head);
  73
  74         /*
  75          * This happens when the module is removed, it doesn't
  76          * really matter any more save for completeness
  77          */
  78         if (!list_empty(&bss->hidden_list))
  79                 list_del(&bss->hidden_list);
  80
  81         kfree(bss);
  82 }
  83
  84 static inline void bss_ref_get(struct cfg80211_registered_device *dev,
  85                                struct cfg80211_internal_bss *bss)
  86 {
  87         lockdep_assert_held(&dev->bss_lock);
  88
  89         bss->refcount++;
  90         if (bss->pub.hidden_beacon_bss) {
  91                 bss = container_of(bss->pub.hidden_beacon_bss,
  92                                    struct cfg80211_internal_bss,
  93                                    pub);
  94                 bss->refcount++;
  95         }
  96 }
  97
  98 static inline void bss_ref_put(struct cfg80211_registered_device *dev,
  99                                struct cfg80211_internal_bss *bss)
 100 {
 101         lockdep_assert_held(&dev->bss_lock);
 102
 103         if (bss->pub.hidden_beacon_bss) {
 104                 struct cfg80211_internal_bss *hbss;
 105                 hbss = container_of(bss->pub.hidden_beacon_bss,
 106                                     struct cfg80211_internal_bss,
 107                                     pub);
 108                 hbss->refcount--;
 109                 if (hbss->refcount == 0)
 110                         bss_free(hbss);
 111         }
 112         bss->refcount--;
 113         if (bss->refcount == 0)
 114                 bss_free(bss);
 115 }
 116
 117 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
 118                                   struct cfg80211_internal_bss *bss)
 119 {
 120         lockdep_assert_held(&dev->bss_lock);
 121
 122         if (!list_empty(&bss->hidden_list)) {
 123                 /*
 124                  * don't remove the beacon entry if it has
 125                  * probe responses associated with it
 126                  */
 127                 if (!bss->pub.hidden_beacon_bss)
 128                         return false;
 129                 /*
 130                  * if it's a probe response entry break its
 131                  * link to the other entries in the group
 132                  */
 133                 list_del_init(&bss->hidden_list);
 134         }
 135
 136         list_del_init(&bss->list);
 137         rb_erase(&bss->rbn, &dev->bss_tree);
 138         bss_ref_put(dev, bss);
 139         return true;
 140 }
 141
 142 static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
 143                                   unsigned long expire_time)
 144 {
 145         struct cfg80211_internal_bss *bss, *tmp;
 146         bool expired = false;
 147
 148         lockdep_assert_held(&dev->bss_lock);
 149
 150         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 151                 if (atomic_read(&bss->hold))
 152                         continue;
 153                 if (!time_after(expire_time, bss->ts))
 154                         continue;
 155
 156                 if (__cfg80211_unlink_bss(dev, bss))
 157                         expired = true;
 158         }
 159
 160         if (expired)
 161                 dev->bss_generation++;
 162 }
 163
 164 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
 165 {
 166         struct cfg80211_scan_request *request;
 167         struct wireless_dev *wdev;
 168 #ifdef CONFIG_CFG80211_WEXT
 169         union iwreq_data wrqu;
 170 #endif
 171
 172         ASSERT_RTNL();
 173
 174         request = rdev->scan_req;
 175
 176         if (!request)
 177                 return;
 178
 179         wdev = request->wdev;
 180
 181         /*
 182          * This must be before sending the other events!
 183          * Otherwise, wpa_supplicant gets completely confused with
 184          * wext events.
 185          */
 186         if (wdev->netdev)
 187                 cfg80211_sme_scan_done(wdev->netdev);
 188
 189         if (request->aborted) {
 190                 nl80211_send_scan_aborted(rdev, wdev);
 191         } else {
 192                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 193                         /* flush entries from previous scans */
 194                         spin_lock_bh(&rdev->bss_lock);
 195                         __cfg80211_bss_expire(rdev, request->scan_start);
 196                         spin_unlock_bh(&rdev->bss_lock);
 197                 }
 198                 nl80211_send_scan_done(rdev, wdev);
 199         }
 200
 201 #ifdef CONFIG_CFG80211_WEXT
 202         if (wdev->netdev && !request->aborted) {
 203                 memset(&wrqu, 0, sizeof(wrqu));
 204
 205                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 206         }
 207 #endif
 208
 209         if (wdev->netdev)
 210                 dev_put(wdev->netdev);
 211
 212         rdev->scan_req = NULL;
 213
 214         /*
 215          * OK. If this is invoked with "leak" then we can't
 216          * free this ... but we've cleaned it up anyway. The
 217          * driver failed to call the scan_done callback, so
 218          * all bets are off, it might still be trying to use
 219          * the scan request or not ... if it accesses the dev
 220          * in there (it shouldn't anyway) then it may crash.
 221          */
 222         if (!leak)
 223                 kfree(request);
 224 }
 225
 226 void __cfg80211_scan_done(struct work_struct *wk)
 227 {
 228         struct cfg80211_registered_device *rdev;
 229
 230         rdev = container_of(wk, struct cfg80211_registered_device,
 231                             scan_done_wk);
 232
 233         rtnl_lock();
 234         ___cfg80211_scan_done(rdev, false);
 235         rtnl_unlock();
 236 }
 237
 238 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 239 {
 240         trace_cfg80211_scan_done(request, aborted);
 241         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
 242
 243         request->aborted = aborted;
 244         request->notified = true;
 245         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
 246 }
 247 EXPORT_SYMBOL(cfg80211_scan_done);
 248
 249 void __cfg80211_sched_scan_results(struct work_struct *wk)
 250 {
 251         struct cfg80211_registered_device *rdev;
 252         struct cfg80211_sched_scan_request *request;
 253
 254         rdev = container_of(wk, struct cfg80211_registered_device,
 255                             sched_scan_results_wk);
 256
 257         request = rdev->sched_scan_req;
 258
 259         rtnl_lock();
 260
 261         /* we don't have sched_scan_req anymore if the scan is stopping */
 262         if (request) {
 263                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 264                         /* flush entries from previous scans */
 265                         spin_lock_bh(&rdev->bss_lock);
 266                         __cfg80211_bss_expire(rdev, request->scan_start);
 267                         spin_unlock_bh(&rdev->bss_lock);
 268                         request->scan_start =
 269                                 jiffies + msecs_to_jiffies(request->interval);
 270                 }
 271                 nl80211_send_sched_scan_results(rdev, request->dev);
 272         }
 273
 274         rtnl_unlock();
 275 }
 276
 277 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 278 {
 279         trace_cfg80211_sched_scan_results(wiphy);
 280         /* ignore if we're not scanning */
 281         if (wiphy_to_dev(wiphy)->sched_scan_req)
 282                 queue_work(cfg80211_wq,
 283                            &wiphy_to_dev(wiphy)->sched_scan_results_wk);
 284 }
 285 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 286
 287 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 288 {
 289         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 290
 291         trace_cfg80211_sched_scan_stopped(wiphy);
 292
 293         rtnl_lock();
 294         __cfg80211_stop_sched_scan(rdev, true);
 295         rtnl_unlock();
 296 }
 297 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 298
 299 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 300                                bool driver_initiated)
 301 {
 302         struct net_device *dev;
 303
 304         ASSERT_RTNL();
 305
 306         if (!rdev->sched_scan_req)
 307                 return -ENOENT;
 308
 309         dev = rdev->sched_scan_req->dev;
 310
 311         if (!driver_initiated) {
 312                 int err = rdev_sched_scan_stop(rdev, dev);
 313                 if (err)
 314                         return err;
 315         }
 316
 317         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 318
 319         kfree(rdev->sched_scan_req);
 320         rdev->sched_scan_req = NULL;
 321
 322         return 0;
 323 }
 324
 325 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 326                       unsigned long age_secs)
 327 {
 328         struct cfg80211_internal_bss *bss;
 329         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 330
 331         spin_lock_bh(&dev->bss_lock);
 332         list_for_each_entry(bss, &dev->bss_list, list)
 333                 bss->ts -= age_jiffies;
 334         spin_unlock_bh(&dev->bss_lock);
 335 }
 336
 337 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 338 {
 339         __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 340 }
 341
 342 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 343 {
 344         while (len > 2 && ies[0] != eid) {
 345                 len -= ies[1] + 2;
 346                 ies += ies[1] + 2;
 347         }
 348         if (len < 2)
 349                 return NULL;
 350         if (len < 2 + ies[1])
 351                 return NULL;
 352         return ies;
 353 }
 354 EXPORT_SYMBOL(cfg80211_find_ie);
 355
 356 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 357                                   const u8 *ies, int len)
 358 {
 359         struct ieee80211_vendor_ie *ie;
 360         const u8 *pos = ies, *end = ies + len;
 361         int ie_oui;
 362
 363         while (pos < end) {
 364                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 365                                        end - pos);
 366                 if (!pos)
 367                         return NULL;
 368
 369                 ie = (struct ieee80211_vendor_ie *)pos;
 370
 371                 /* make sure we can access ie->len */
 372                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 373
 374                 if (ie->len < sizeof(*ie))
 375                         goto cont;
 376
 377                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 378                 if (ie_oui == oui && ie->oui_type == oui_type)
 379                         return pos;
 380 cont:
 381                 pos += 2 + ie->len;
 382         }
 383         return NULL;
 384 }
 385 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 386
 387 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 388                    const u8 *ssid, size_t ssid_len)
 389 {
 390         const struct cfg80211_bss_ies *ies;
 391         const u8 *ssidie;
 392
 393         if (bssid && !ether_addr_equal(a->bssid, bssid))
 394                 return false;
 395
 396         if (!ssid)
 397                 return true;
 398
 399         ies = rcu_access_pointer(a->ies);
 400         if (!ies)
 401                 return false;
 402         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 403         if (!ssidie)
 404                 return false;
 405         if (ssidie[1] != ssid_len)
 406                 return false;
 407         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 408 }
 409
 410 /**
 411  * enum bss_compare_mode - BSS compare mode
 412  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 413  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 414  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 415  */
 416 enum bss_compare_mode {
 417         BSS_CMP_REGULAR,
 418         BSS_CMP_HIDE_ZLEN,
 419         BSS_CMP_HIDE_NUL,
 420 };
 421
 422 static int cmp_bss(struct cfg80211_bss *a,
 423                    struct cfg80211_bss *b,
 424                    enum bss_compare_mode mode)
 425 {
 426         const struct cfg80211_bss_ies *a_ies, *b_ies;
 427         const u8 *ie1 = NULL;
 428         const u8 *ie2 = NULL;
 429         int i, r;
 430
 431         if (a->channel != b->channel)
 432                 return b->channel->center_freq - a->channel->center_freq;
 433
 434         a_ies = rcu_access_pointer(a->ies);
 435         if (!a_ies)
 436                 return -1;
 437         b_ies = rcu_access_pointer(b->ies);
 438         if (!b_ies)
 439                 return 1;
 440
 441         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 442                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 443                                        a_ies->data, a_ies->len);
 444         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 445                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 446                                        b_ies->data, b_ies->len);
 447         if (ie1 && ie2) {
 448                 int mesh_id_cmp;
 449
 450                 if (ie1[1] == ie2[1])
 451                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 452                 else
 453                         mesh_id_cmp = ie2[1] - ie1[1];
 454
 455                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 456                                        a_ies->data, a_ies->len);
 457                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 458                                        b_ies->data, b_ies->len);
 459                 if (ie1 && ie2) {
 460                         if (mesh_id_cmp)
 461                                 return mesh_id_cmp;
 462                         if (ie1[1] != ie2[1])
 463                                 return ie2[1] - ie1[1];
 464                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 465                 }
 466         }
 467
 468         /*
 469          * we can't use compare_ether_addr here since we need a < > operator.
 470          * The binary return value of compare_ether_addr isn't enough
 471          */
 472         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 473         if (r)
 474                 return r;
 475
 476         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 477         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 478
 479         if (!ie1 && !ie2)
 480                 return 0;
 481
 482         /*
 483          * Note that with "hide_ssid", the function returns a match if
 484          * the already-present BSS ("b") is a hidden SSID beacon for
 485          * the new BSS ("a").
 486          */
 487
 488         /* sort missing IE before (left of) present IE */
 489         if (!ie1)
 490                 return -1;
 491         if (!ie2)
 492                 return 1;
 493
 494         switch (mode) {
 495         case BSS_CMP_HIDE_ZLEN:
 496                 /*
 497                  * In ZLEN mode we assume the BSS entry we're
 498                  * looking for has a zero-length SSID. So if
 499                  * the one we're looking at right now has that,
 500                  * return 0. Otherwise, return the difference
 501                  * in length, but since we're looking for the
 502                  * 0-length it's really equivalent to returning
 503                  * the length of the one we're looking at.
 504                  *
 505                  * No content comparison is needed as we assume
 506                  * the content length is zero.
 507                  */
 508                 return ie2[1];
 509         case BSS_CMP_REGULAR:
 510         default:
 511                 /* sort by length first, then by contents */
 512                 if (ie1[1] != ie2[1])
 513                         return ie2[1] - ie1[1];
 514                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 515         case BSS_CMP_HIDE_NUL:
 516                 if (ie1[1] != ie2[1])
 517                         return ie2[1] - ie1[1];
 518                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 519                 for (i = 0; i < ie2[1]; i++)
 520                         if (ie2[i + 2])
 521                                 return -1;
 522                 return 0;
 523         }
 524 }
 525
 526 /* Returned bss is reference counted and must be cleaned up appropriately. */
 527 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 528                                       struct ieee80211_channel *channel,
 529                                       const u8 *bssid,
 530                                       const u8 *ssid, size_t ssid_len,
 531                                       u16 capa_mask, u16 capa_val)
 532 {
 533         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 534         struct cfg80211_internal_bss *bss, *res = NULL;
 535         unsigned long now = jiffies;
 536
 537         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 538                                capa_val);
 539
 540         spin_lock_bh(&dev->bss_lock);
 541
 542         list_for_each_entry(bss, &dev->bss_list, list) {
 543                 if ((bss->pub.capability & capa_mask) != capa_val)
 544                         continue;
 545                 if (channel && bss->pub.channel != channel)
 546                         continue;
 547                 /* Don't get expired BSS structs */
 548                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 549                     !atomic_read(&bss->hold))
 550                         continue;
 551                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 552                         res = bss;
 553                         bss_ref_get(dev, res);
 554                         break;
 555                 }
 556         }
 557
 558         spin_unlock_bh(&dev->bss_lock);
 559         if (!res)
 560                 return NULL;
 561         trace_cfg80211_return_bss(&res->pub);
 562         return &res->pub;
 563 }
 564 EXPORT_SYMBOL(cfg80211_get_bss);
 565
 566 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 567                           struct cfg80211_internal_bss *bss)
 568 {
 569         struct rb_node **p = &dev->bss_tree.rb_node;
 570         struct rb_node *parent = NULL;
 571         struct cfg80211_internal_bss *tbss;
 572         int cmp;
 573
 574         while (*p) {
 575                 parent = *p;
 576                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 577
 578                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 579
 580                 if (WARN_ON(!cmp)) {
 581                         /* will sort of leak this BSS */
 582                         return;
 583                 }
 584
 585                 if (cmp < 0)
 586                         p = &(*p)->rb_left;
 587                 else
 588                         p = &(*p)->rb_right;
 589         }
 590
 591         rb_link_node(&bss->rbn, parent, p);
 592         rb_insert_color(&bss->rbn, &dev->bss_tree);
 593 }
 594
 595 static struct cfg80211_internal_bss *
 596 rb_find_bss(struct cfg80211_registered_device *dev,
 597             struct cfg80211_internal_bss *res,
 598             enum bss_compare_mode mode)
 599 {
 600         struct rb_node *n = dev->bss_tree.rb_node;
 601         struct cfg80211_internal_bss *bss;
 602         int r;
 603
 604         while (n) {
 605                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 606                 r = cmp_bss(&res->pub, &bss->pub, mode);
 607
 608                 if (r == 0)
 609                         return bss;
 610                 else if (r < 0)
 611                         n = n->rb_left;
 612                 else
 613                         n = n->rb_right;
 614         }
 615
 616         return NULL;
 617 }
 618
 619 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
 620                                    struct cfg80211_internal_bss *new)
 621 {
 622         const struct cfg80211_bss_ies *ies;
 623         struct cfg80211_internal_bss *bss;
 624         const u8 *ie;
 625         int i, ssidlen;
 626         u8 fold = 0;
 627
 628         ies = rcu_access_pointer(new->pub.beacon_ies);
 629         if (WARN_ON(!ies))
 630                 return false;
 631
 632         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 633         if (!ie) {
 634                 /* nothing to do */
 635                 return true;
 636         }
 637
 638         ssidlen = ie[1];
 639         for (i = 0; i < ssidlen; i++)
 640                 fold |= ie[2 + i];
 641
 642         if (fold) {
 643                 /* not a hidden SSID */
 644                 return true;
 645         }
 646
 647         /* This is the bad part ... */
 648
 649         list_for_each_entry(bss, &dev->bss_list, list) {
 650                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 651                         continue;
 652                 if (bss->pub.channel != new->pub.channel)
 653                         continue;
 654                 if (rcu_access_pointer(bss->pub.beacon_ies))
 655                         continue;
 656                 ies = rcu_access_pointer(bss->pub.ies);
 657                 if (!ies)
 658                         continue;
 659                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 660                 if (!ie)
 661                         continue;
 662                 if (ssidlen && ie[1] != ssidlen)
 663                         continue;
 664                 /* that would be odd ... */
 665                 if (bss->pub.beacon_ies)
 666                         continue;
 667                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 668                         continue;
 669                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 670                         list_del(&bss->hidden_list);
 671                 /* combine them */
 672                 list_add(&bss->hidden_list, &new->hidden_list);
 673                 bss->pub.hidden_beacon_bss = &new->pub;
 674                 new->refcount += bss->refcount;
 675                 rcu_assign_pointer(bss->pub.beacon_ies,
 676                                    new->pub.beacon_ies);
 677         }
 678
 679         return true;
 680 }
 681
 682 /* Returned bss is reference counted and must be cleaned up appropriately. */
 683 static struct cfg80211_internal_bss *
 684 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 685                     struct cfg80211_internal_bss *tmp)
 686 {
 687         struct cfg80211_internal_bss *found = NULL;
 688
 689         if (WARN_ON(!tmp->pub.channel))
 690                 return NULL;
 691
 692         tmp->ts = jiffies;
 693
 694         spin_lock_bh(&dev->bss_lock);
 695
 696         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 697                 spin_unlock_bh(&dev->bss_lock);
 698                 return NULL;
 699         }
 700
 701         found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
 702
 703         if (found) {
 704                 /* Update IEs */
 705                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 706                         const struct cfg80211_bss_ies *old;
 707
 708                         old = rcu_access_pointer(found->pub.proberesp_ies);
 709
 710                         rcu_assign_pointer(found->pub.proberesp_ies,
 711                                            tmp->pub.proberesp_ies);
 712                         /* Override possible earlier Beacon frame IEs */
 713                         rcu_assign_pointer(found->pub.ies,
 714                                            tmp->pub.proberesp_ies);
 715                         if (old)
 716                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 717                                           rcu_head);
 718                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 719                         const struct cfg80211_bss_ies *old;
 720                         struct cfg80211_internal_bss *bss;
 721
 722                         if (found->pub.hidden_beacon_bss &&
 723                             !list_empty(&found->hidden_list)) {
 724                                 const struct cfg80211_bss_ies *f;
 725
 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
 736                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 737                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 738                                           rcu_head);
 739                                 goto drop;
 740                         }
 741
 742                         old = rcu_access_pointer(found->pub.beacon_ies);
 743
 744                         rcu_assign_pointer(found->pub.beacon_ies,
 745                                            tmp->pub.beacon_ies);
 746
 747                         /* Override IEs if they were from a beacon before */
 748                         if (old == rcu_access_pointer(found->pub.ies))
 749                                 rcu_assign_pointer(found->pub.ies,
 750                                                    tmp->pub.beacon_ies);
 751
 752                         /* Assign beacon IEs to all sub entries */
 753                         list_for_each_entry(bss, &found->hidden_list,
 754                                             hidden_list) {
 755                                 const struct cfg80211_bss_ies *ies;
 756
 757                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 758                                 WARN_ON(ies != old);
 759
 760                                 rcu_assign_pointer(bss->pub.beacon_ies,
 761                                                    tmp->pub.beacon_ies);
 762                         }
 763
 764                         if (old)
 765                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 766                                           rcu_head);
 767                 }
 768
 769                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 770                 found->pub.signal = tmp->pub.signal;
 771                 found->pub.capability = tmp->pub.capability;
 772                 found->ts = tmp->ts;
 773         } else {
 774                 struct cfg80211_internal_bss *new;
 775                 struct cfg80211_internal_bss *hidden;
 776                 struct cfg80211_bss_ies *ies;
 777
 778                 /*
 779                  * create a copy -- the "res" variable that is passed in
 780                  * is allocated on the stack since it's not needed in the
 781                  * more common case of an update
 782                  */
 783                 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
 784                               GFP_ATOMIC);
 785                 if (!new) {
 786                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 787                         if (ies)
 788                                 kfree_rcu(ies, rcu_head);
 789                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 790                         if (ies)
 791                                 kfree_rcu(ies, rcu_head);
 792                         goto drop;
 793                 }
 794                 memcpy(new, tmp, sizeof(*new));
 795                 new->refcount = 1;
 796                 INIT_LIST_HEAD(&new->hidden_list);
 797
 798                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 799                         hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
 800                         if (!hidden)
 801                                 hidden = rb_find_bss(dev, tmp,
 802                                                      BSS_CMP_HIDE_NUL);
 803                         if (hidden) {
 804                                 new->pub.hidden_beacon_bss = &hidden->pub;
 805                                 list_add(&new->hidden_list,
 806                                          &hidden->hidden_list);
 807                                 hidden->refcount++;
 808                                 rcu_assign_pointer(new->pub.beacon_ies,
 809                                                    hidden->pub.beacon_ies);
 810                         }
 811                 } else {
 812                         /*
 813                          * Ok so we found a beacon, and don't have an entry. If
 814                          * it's a beacon with hidden SSID, we might be in for an
 815                          * expensive search for any probe responses that should
 816                          * be grouped with this beacon for updates ...
 817                          */
 818                         if (!cfg80211_combine_bsses(dev, new)) {
 819                                 kfree(new);
 820                                 goto drop;
 821                         }
 822                 }
 823
 824                 list_add_tail(&new->list, &dev->bss_list);
 825                 rb_insert_bss(dev, new);
 826                 found = new;
 827         }
 828
 829         dev->bss_generation++;
 830         bss_ref_get(dev, found);
 831         spin_unlock_bh(&dev->bss_lock);
 832
 833         return found;
 834  drop:
 835         spin_unlock_bh(&dev->bss_lock);
 836         return NULL;
 837 }
 838
 839 static struct ieee80211_channel *
 840 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 841                          struct ieee80211_channel *channel)
 842 {
 843         const u8 *tmp;
 844         u32 freq;
 845         int channel_number = -1;
 846
 847         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 848         if (tmp && tmp[1] == 1) {
 849                 channel_number = tmp[2];
 850         } else {
 851                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 852                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 853                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 854
 855                         channel_number = htop->primary_chan;
 856                 }
 857         }
 858
 859         if (channel_number < 0)
 860                 return channel;
 861
 862         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 863         channel = ieee80211_get_channel(wiphy, freq);
 864         if (!channel)
 865                 return NULL;
 866         if (channel->flags & IEEE80211_CHAN_DISABLED)
 867                 return NULL;
 868         return channel;
 869 }
 870
 871 /* Returned bss is reference counted and must be cleaned up appropriately. */
 872 struct cfg80211_bss*
 873 cfg80211_inform_bss(struct wiphy *wiphy,
 874                     struct ieee80211_channel *channel,
 875                     const u8 *bssid, u64 tsf, u16 capability,
 876                     u16 beacon_interval, const u8 *ie, size_t ielen,
 877                     s32 signal, gfp_t gfp)
 878 {
 879         struct cfg80211_bss_ies *ies;
 880         struct cfg80211_internal_bss tmp = {}, *res;
 881
 882         if (WARN_ON(!wiphy))
 883                 return NULL;
 884
 885         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 886                         (signal < 0 || signal > 100)))
 887                 return NULL;
 888
 889         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
 890         if (!channel)
 891                 return NULL;
 892
 893         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 894         tmp.pub.channel = channel;
 895         tmp.pub.signal = signal;
 896         tmp.pub.beacon_interval = beacon_interval;
 897         tmp.pub.capability = capability;
 898         /*
 899          * Since we do not know here whether the IEs are from a Beacon or Probe
 900          * Response frame, we need to pick one of the options and only use it
 901          * with the driver that does not provide the full Beacon/Probe Response
 902          * frame. Use Beacon frame pointer to avoid indicating that this should
 903          * override the IEs pointer should we have received an earlier
 904          * indication of Probe Response data.
 905          */
 906         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 907         if (!ies)
 908                 return NULL;
 909         ies->len = ielen;
 910         ies->tsf = tsf;
 911         memcpy(ies->data, ie, ielen);
 912
 913         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 914         rcu_assign_pointer(tmp.pub.ies, ies);
 915
 916         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 917         if (!res)
 918                 return NULL;
 919
 920         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 921                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 922
 923         trace_cfg80211_return_bss(&res->pub);
 924         /* cfg80211_bss_update gives us a referenced result */
 925         return &res->pub;
 926 }
 927 EXPORT_SYMBOL(cfg80211_inform_bss);
 928
 929 /* Returned bss is reference counted and must be cleaned up appropriately. */
 930 struct cfg80211_bss *
 931 cfg80211_inform_bss_frame(struct wiphy *wiphy,
 932                           struct ieee80211_channel *channel,
 933                           struct ieee80211_mgmt *mgmt, size_t len,
 934                           s32 signal, gfp_t gfp)
 935 {
 936         struct cfg80211_internal_bss tmp = {}, *res;
 937         struct cfg80211_bss_ies *ies;
 938         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 939                                       u.probe_resp.variable);
 940
 941         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 942                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 943
 944         trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal);
 945
 946         if (WARN_ON(!mgmt))
 947                 return NULL;
 948
 949         if (WARN_ON(!wiphy))
 950                 return NULL;
 951
 952         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 953                     (signal < 0 || signal > 100)))
 954                 return NULL;
 955
 956         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 957                 return NULL;
 958
 959         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 960                                            ielen, channel);
 961         if (!channel)
 962                 return NULL;
 963
 964         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 965         if (!ies)
 966                 return NULL;
 967         ies->len = ielen;
 968         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 969         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 970
 971         if (ieee80211_is_probe_resp(mgmt->frame_control))
 972                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 973         else
 974                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 975         rcu_assign_pointer(tmp.pub.ies, ies);
 976
 977         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 978         tmp.pub.channel = channel;
 979         tmp.pub.signal = signal;
 980         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 981         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 982
 983         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
 984         if (!res)
 985                 return NULL;
 986
 987         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 988                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 989
 990         trace_cfg80211_return_bss(&res->pub);
 991         /* cfg80211_bss_update gives us a referenced result */
 992         return &res->pub;
 993 }
 994 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 995
 996 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 997 {
 998         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 999         struct cfg80211_internal_bss *bss;
1000
1001         if (!pub)
1002                 return;
1003
1004         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1005
1006         spin_lock_bh(&dev->bss_lock);
1007         bss_ref_get(dev, bss);
1008         spin_unlock_bh(&dev->bss_lock);
1009 }
1010 EXPORT_SYMBOL(cfg80211_ref_bss);
1011
1012 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1013 {
1014         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1015         struct cfg80211_internal_bss *bss;
1016
1017         if (!pub)
1018                 return;
1019
1020         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1021
1022         spin_lock_bh(&dev->bss_lock);
1023         bss_ref_put(dev, bss);
1024         spin_unlock_bh(&dev->bss_lock);
1025 }
1026 EXPORT_SYMBOL(cfg80211_put_bss);
1027
1028 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1029 {
1030         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1031         struct cfg80211_internal_bss *bss;
1032
1033         if (WARN_ON(!pub))
1034                 return;
1035
1036         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1037
1038         spin_lock_bh(&dev->bss_lock);
1039         if (!list_empty(&bss->list)) {
1040                 if (__cfg80211_unlink_bss(dev, bss))
1041                         dev->bss_generation++;
1042         }
1043         spin_unlock_bh(&dev->bss_lock);
1044 }
1045 EXPORT_SYMBOL(cfg80211_unlink_bss);
1046
1047 #ifdef CONFIG_CFG80211_WEXT
1048 static struct cfg80211_registered_device *
1049 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1050 {
1051         struct cfg80211_registered_device *rdev;
1052         struct net_device *dev;
1053
1054         ASSERT_RTNL();
1055
1056         dev = dev_get_by_index(net, ifindex);
1057         if (!dev)
1058                 return ERR_PTR(-ENODEV);
1059         if (dev->ieee80211_ptr)
1060                 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
1061         else
1062                 rdev = ERR_PTR(-ENODEV);
1063         dev_put(dev);
1064         return rdev;
1065 }
1066
1067 int cfg80211_wext_siwscan(struct net_device *dev,
1068                           struct iw_request_info *info,
1069                           union iwreq_data *wrqu, char *extra)
1070 {
1071         struct cfg80211_registered_device *rdev;
1072         struct wiphy *wiphy;
1073         struct iw_scan_req *wreq = NULL;
1074         struct cfg80211_scan_request *creq = NULL;
1075         int i, err, n_channels = 0;
1076         enum ieee80211_band band;
1077
1078         if (!netif_running(dev))
1079                 return -ENETDOWN;
1080
1081         if (wrqu->data.length == sizeof(struct iw_scan_req))
1082                 wreq = (struct iw_scan_req *)extra;
1083
1084         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1085
1086         if (IS_ERR(rdev))
1087                 return PTR_ERR(rdev);
1088
1089         if (rdev->scan_req) {
1090                 err = -EBUSY;
1091                 goto out;
1092         }
1093
1094         wiphy = &rdev->wiphy;
1095
1096         /* Determine number of channels, needed to allocate creq */
1097         if (wreq && wreq->num_channels)
1098                 n_channels = wreq->num_channels;
1099         else {
1100                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1101                         if (wiphy->bands[band])
1102                                 n_channels += wiphy->bands[band]->n_channels;
1103         }
1104
1105         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1106                        n_channels * sizeof(void *),
1107                        GFP_ATOMIC);
1108         if (!creq) {
1109                 err = -ENOMEM;
1110                 goto out;
1111         }
1112
1113         creq->wiphy = wiphy;
1114         creq->wdev = dev->ieee80211_ptr;
1115         /* SSIDs come after channels */
1116         creq->ssids = (void *)&creq->channels[n_channels];
1117         creq->n_channels = n_channels;
1118         creq->n_ssids = 1;
1119         creq->scan_start = jiffies;
1120
1121         /* translate "Scan on frequencies" request */
1122         i = 0;
1123         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1124                 int j;
1125
1126                 if (!wiphy->bands[band])
1127                         continue;
1128
1129                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1130                         /* ignore disabled channels */
1131                         if (wiphy->bands[band]->channels[j].flags &
1132                                                 IEEE80211_CHAN_DISABLED)
1133                                 continue;
1134
1135                         /* If we have a wireless request structure and the
1136                          * wireless request specifies frequencies, then search
1137                          * for the matching hardware channel.
1138                          */
1139                         if (wreq && wreq->num_channels) {
1140                                 int k;
1141                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1142                                 for (k = 0; k < wreq->num_channels; k++) {
1143                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1144                                         if (wext_freq == wiphy_freq)
1145                                                 goto wext_freq_found;
1146                                 }
1147                                 goto wext_freq_not_found;
1148                         }
1149
1150                 wext_freq_found:
1151                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1152                         i++;
1153                 wext_freq_not_found: ;
1154                 }
1155         }
1156         /* No channels found? */
1157         if (!i) {
1158                 err = -EINVAL;
1159                 goto out;
1160         }
1161
1162         /* Set real number of channels specified in creq->channels[] */
1163         creq->n_channels = i;
1164
1165         /* translate "Scan for SSID" request */
1166         if (wreq) {
1167                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1168                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1169                                 err = -EINVAL;
1170                                 goto out;
1171                         }
1172                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1173                         creq->ssids[0].ssid_len = wreq->essid_len;
1174                 }
1175                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1176                         creq->n_ssids = 0;
1177         }
1178
1179         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1180                 if (wiphy->bands[i])
1181                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1182
1183         rdev->scan_req = creq;
1184         err = rdev_scan(rdev, creq);
1185         if (err) {
1186                 rdev->scan_req = NULL;
1187                 /* creq will be freed below */
1188         } else {
1189                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1190                 /* creq now owned by driver */
1191                 creq = NULL;
1192                 dev_hold(dev);
1193         }
1194  out:
1195         kfree(creq);
1196         return err;
1197 }
1198 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1199
1200 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1201                                    const struct cfg80211_bss_ies *ies,
1202                                    char **current_ev, char *end_buf)
1203 {
1204         const u8 *pos, *end, *next;
1205         struct iw_event iwe;
1206
1207         if (!ies)
1208                 return;
1209
1210         /*
1211          * If needed, fragment the IEs buffer (at IE boundaries) into short
1212          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1213          */
1214         pos = ies->data;
1215         end = pos + ies->len;
1216
1217         while (end - pos > IW_GENERIC_IE_MAX) {
1218                 next = pos + 2 + pos[1];
1219                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1220                         next = next + 2 + next[1];
1221
1222                 memset(&iwe, 0, sizeof(iwe));
1223                 iwe.cmd = IWEVGENIE;
1224                 iwe.u.data.length = next - pos;
1225                 *current_ev = iwe_stream_add_point(info, *current_ev,
1226                                                    end_buf, &iwe,
1227                                                    (void *)pos);
1228
1229                 pos = next;
1230         }
1231
1232         if (end > pos) {
1233                 memset(&iwe, 0, sizeof(iwe));
1234                 iwe.cmd = IWEVGENIE;
1235                 iwe.u.data.length = end - pos;
1236                 *current_ev = iwe_stream_add_point(info, *current_ev,
1237                                                    end_buf, &iwe,
1238                                                    (void *)pos);
1239         }
1240 }
1241
1242 static char *
1243 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1244               struct cfg80211_internal_bss *bss, char *current_ev,
1245               char *end_buf)
1246 {
1247         const struct cfg80211_bss_ies *ies;
1248         struct iw_event iwe;
1249         const u8 *ie;
1250         u8 *buf, *cfg, *p;
1251         int rem, i, sig;
1252         bool ismesh = false;
1253
1254         memset(&iwe, 0, sizeof(iwe));
1255         iwe.cmd = SIOCGIWAP;
1256         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1257         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1258         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1259                                           IW_EV_ADDR_LEN);
1260
1261         memset(&iwe, 0, sizeof(iwe));
1262         iwe.cmd = SIOCGIWFREQ;
1263         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1264         iwe.u.freq.e = 0;
1265         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1266                                           IW_EV_FREQ_LEN);
1267
1268         memset(&iwe, 0, sizeof(iwe));
1269         iwe.cmd = SIOCGIWFREQ;
1270         iwe.u.freq.m = bss->pub.channel->center_freq;
1271         iwe.u.freq.e = 6;
1272         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1273                                           IW_EV_FREQ_LEN);
1274
1275         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1276                 memset(&iwe, 0, sizeof(iwe));
1277                 iwe.cmd = IWEVQUAL;
1278                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1279                                      IW_QUAL_NOISE_INVALID |
1280                                      IW_QUAL_QUAL_UPDATED;
1281                 switch (wiphy->signal_type) {
1282                 case CFG80211_SIGNAL_TYPE_MBM:
1283                         sig = bss->pub.signal / 100;
1284                         iwe.u.qual.level = sig;
1285                         iwe.u.qual.updated |= IW_QUAL_DBM;
1286                         if (sig < -110)         /* rather bad */
1287                                 sig = -110;
1288                         else if (sig > -40)     /* perfect */
1289                                 sig = -40;
1290                         /* will give a range of 0 .. 70 */
1291                         iwe.u.qual.qual = sig + 110;
1292                         break;
1293                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1294                         iwe.u.qual.level = bss->pub.signal;
1295                         /* will give range 0 .. 100 */
1296                         iwe.u.qual.qual = bss->pub.signal;
1297                         break;
1298                 default:
1299                         /* not reached */
1300                         break;
1301                 }
1302                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1303                                                   &iwe, IW_EV_QUAL_LEN);
1304         }
1305
1306         memset(&iwe, 0, sizeof(iwe));
1307         iwe.cmd = SIOCGIWENCODE;
1308         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1309                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1310         else
1311                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1312         iwe.u.data.length = 0;
1313         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1314                                           &iwe, "");
1315
1316         rcu_read_lock();
1317         ies = rcu_dereference(bss->pub.ies);
1318         rem = ies->len;
1319         ie = ies->data;
1320
1321         while (rem >= 2) {
1322                 /* invalid data */
1323                 if (ie[1] > rem - 2)
1324                         break;
1325
1326                 switch (ie[0]) {
1327                 case WLAN_EID_SSID:
1328                         memset(&iwe, 0, sizeof(iwe));
1329                         iwe.cmd = SIOCGIWESSID;
1330                         iwe.u.data.length = ie[1];
1331                         iwe.u.data.flags = 1;
1332                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1333                                                           &iwe, (u8 *)ie + 2);
1334                         break;
1335                 case WLAN_EID_MESH_ID:
1336                         memset(&iwe, 0, sizeof(iwe));
1337                         iwe.cmd = SIOCGIWESSID;
1338                         iwe.u.data.length = ie[1];
1339                         iwe.u.data.flags = 1;
1340                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1341                                                           &iwe, (u8 *)ie + 2);
1342                         break;
1343                 case WLAN_EID_MESH_CONFIG:
1344                         ismesh = true;
1345                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1346                                 break;
1347                         buf = kmalloc(50, GFP_ATOMIC);
1348                         if (!buf)
1349                                 break;
1350                         cfg = (u8 *)ie + 2;
1351                         memset(&iwe, 0, sizeof(iwe));
1352                         iwe.cmd = IWEVCUSTOM;
1353                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1354                                 "0x%02X", cfg[0]);
1355                         iwe.u.data.length = strlen(buf);
1356                         current_ev = iwe_stream_add_point(info, current_ev,
1357                                                           end_buf,
1358                                                           &iwe, buf);
1359                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1360                                 cfg[1]);
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, "Congestion Control Mode ID: 0x%02X",
1366                                 cfg[2]);
1367                         iwe.u.data.length = strlen(buf);
1368                         current_ev = iwe_stream_add_point(info, current_ev,
1369                                                           end_buf,
1370                                                           &iwe, buf);
1371                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1372                         iwe.u.data.length = strlen(buf);
1373                         current_ev = iwe_stream_add_point(info, current_ev,
1374                                                           end_buf,
1375                                                           &iwe, buf);
1376                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1377                         iwe.u.data.length = strlen(buf);
1378                         current_ev = iwe_stream_add_point(info, current_ev,
1379                                                           end_buf,
1380                                                           &iwe, buf);
1381                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1382                         iwe.u.data.length = strlen(buf);
1383                         current_ev = iwe_stream_add_point(info, current_ev,
1384                                                           end_buf,
1385                                                           &iwe, buf);
1386                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1387                         iwe.u.data.length = strlen(buf);
1388                         current_ev = iwe_stream_add_point(info, current_ev,
1389                                                           end_buf,
1390                                                           &iwe, buf);
1391                         kfree(buf);
1392                         break;
1393                 case WLAN_EID_SUPP_RATES:
1394                 case WLAN_EID_EXT_SUPP_RATES:
1395                         /* display all supported rates in readable format */
1396                         p = current_ev + iwe_stream_lcp_len(info);
1397
1398                         memset(&iwe, 0, sizeof(iwe));
1399                         iwe.cmd = SIOCGIWRATE;
1400                         /* Those two flags are ignored... */
1401                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1402
1403                         for (i = 0; i < ie[1]; i++) {
1404                                 iwe.u.bitrate.value =
1405                                         ((ie[i + 2] & 0x7f) * 500000);
1406                                 p = iwe_stream_add_value(info, current_ev, p,
1407                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1408                         }
1409                         current_ev = p;
1410                         break;
1411                 }
1412                 rem -= ie[1] + 2;
1413                 ie += ie[1] + 2;
1414         }
1415
1416         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1417             ismesh) {
1418                 memset(&iwe, 0, sizeof(iwe));
1419                 iwe.cmd = SIOCGIWMODE;
1420                 if (ismesh)
1421                         iwe.u.mode = IW_MODE_MESH;
1422                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1423                         iwe.u.mode = IW_MODE_MASTER;
1424                 else
1425                         iwe.u.mode = IW_MODE_ADHOC;
1426                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1427                                                   &iwe, IW_EV_UINT_LEN);
1428         }
1429
1430         buf = kmalloc(31, GFP_ATOMIC);
1431         if (buf) {
1432                 memset(&iwe, 0, sizeof(iwe));
1433                 iwe.cmd = IWEVCUSTOM;
1434                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1435                 iwe.u.data.length = strlen(buf);
1436                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1437                                                   &iwe, buf);
1438                 memset(&iwe, 0, sizeof(iwe));
1439                 iwe.cmd = IWEVCUSTOM;
1440                 sprintf(buf, " Last beacon: %ums ago",
1441                         elapsed_jiffies_msecs(bss->ts));
1442                 iwe.u.data.length = strlen(buf);
1443                 current_ev = iwe_stream_add_point(info, current_ev,
1444                                                   end_buf, &iwe, buf);
1445                 kfree(buf);
1446         }
1447
1448         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1449         rcu_read_unlock();
1450
1451         return current_ev;
1452 }
1453
1454
1455 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1456                                   struct iw_request_info *info,
1457                                   char *buf, size_t len)
1458 {
1459         char *current_ev = buf;
1460         char *end_buf = buf + len;
1461         struct cfg80211_internal_bss *bss;
1462
1463         spin_lock_bh(&dev->bss_lock);
1464         cfg80211_bss_expire(dev);
1465
1466         list_for_each_entry(bss, &dev->bss_list, list) {
1467                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1468                         spin_unlock_bh(&dev->bss_lock);
1469                         return -E2BIG;
1470                 }
1471                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1472                                            current_ev, end_buf);
1473         }
1474         spin_unlock_bh(&dev->bss_lock);
1475         return current_ev - buf;
1476 }
1477
1478
1479 int cfg80211_wext_giwscan(struct net_device *dev,
1480                           struct iw_request_info *info,
1481                           struct iw_point *data, char *extra)
1482 {
1483         struct cfg80211_registered_device *rdev;
1484         int res;
1485
1486         if (!netif_running(dev))
1487                 return -ENETDOWN;
1488
1489         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1490
1491         if (IS_ERR(rdev))
1492                 return PTR_ERR(rdev);
1493
1494         if (rdev->scan_req)
1495                 return -EAGAIN;
1496
1497         res = ieee80211_scan_results(rdev, info, extra, data->length);
1498         data->length = 0;
1499         if (res >= 0) {
1500                 data->length = res;
1501                 res = 0;
1502         }
1503
1504         return res;
1505 }
1506 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1507 #endif