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