net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  * Copyright 2013-2014  Intel Mobile Communications GmbH
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/wireless.h>
  12 #include <linux/nl80211.h>
  13 #include <linux/etherdevice.h>
  14 #include <net/arp.h>
  15 #include <net/cfg80211.h>
  16 #include <net/cfg80211-wext.h>
  17 #include <net/iw_handler.h>
  18 #include "core.h"
  19 #include "nl80211.h"
  20 #include "wext-compat.h"
  21 #include "rdev-ops.h"
  22
  23 /**
  24  * DOC: BSS tree/list structure
  25  *
  26  * At the top level, the BSS list is kept in both a list in each
  27  * registered device (@bss_list) as well as an RB-tree for faster
  28  * lookup. In the RB-tree, entries can be looked up using their
  29  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  30  * for other BSSes.
  31  *
  32  * Due to the possibility of hidden SSIDs, there's a second level
  33  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  34  * The hidden_list connects all BSSes belonging to a single AP
  35  * that has a hidden SSID, and connects beacon and probe response
  36  * entries. For a probe response entry for a hidden SSID, the
  37  * hidden_beacon_bss pointer points to the BSS struct holding the
  38  * beacon's information.
  39  *
  40  * Reference counting is done for all these references except for
  41  * the hidden_list, so that a beacon BSS struct that is otherwise
  42  * not referenced has one reference for being on the bss_list and
  43  * one for each probe response entry that points to it using the
  44  * hidden_beacon_bss pointer. When a BSS struct that has such a
  45  * pointer is get/put, the refcount update is also propagated to
  46  * the referenced struct, this ensure that it cannot get removed
  47  * while somebody is using the probe response version.
  48  *
  49  * Note that the hidden_beacon_bss pointer never changes, due to
  50  * the reference counting. Therefore, no locking is needed for
  51  * it.
  52  *
  53  * Also note that the hidden_beacon_bss pointer is only relevant
  54  * if the driver uses something other than the IEs, e.g. private
  55  * data stored stored in the BSS struct, since the beacon IEs are
  56  * also linked into the probe response struct.
  57  */
  58
  59 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  60
  61 static void bss_free(struct cfg80211_internal_bss *bss)
  62 {
  63         struct cfg80211_bss_ies *ies;
  64
  65         if (WARN_ON(atomic_read(&bss->hold)))
  66                 return;
  67
  68         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  69         if (ies && !bss->pub.hidden_beacon_bss)
  70                 kfree_rcu(ies, rcu_head);
  71         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  72         if (ies)
  73                 kfree_rcu(ies, rcu_head);
  74
  75         /*
  76          * This happens when the module is removed, it doesn't
  77          * really matter any more save for completeness
  78          */
  79         if (!list_empty(&bss->hidden_list))
  80                 list_del(&bss->hidden_list);
  81
  82         kfree(bss);
  83 }
  84
  85 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
  86                                struct cfg80211_internal_bss *bss)
  87 {
  88         lockdep_assert_held(&rdev->bss_lock);
  89
  90         bss->refcount++;
  91         if (bss->pub.hidden_beacon_bss) {
  92                 bss = container_of(bss->pub.hidden_beacon_bss,
  93                                    struct cfg80211_internal_bss,
  94                                    pub);
  95                 bss->refcount++;
  96         }
  97 }
  98
  99 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
 100                                struct cfg80211_internal_bss *bss)
 101 {
 102         lockdep_assert_held(&rdev->bss_lock);
 103
 104         if (bss->pub.hidden_beacon_bss) {
 105                 struct cfg80211_internal_bss *hbss;
 106                 hbss = container_of(bss->pub.hidden_beacon_bss,
 107                                     struct cfg80211_internal_bss,
 108                                     pub);
 109                 hbss->refcount--;
 110                 if (hbss->refcount == 0)
 111                         bss_free(hbss);
 112         }
 113         bss->refcount--;
 114         if (bss->refcount == 0)
 115                 bss_free(bss);
 116 }
 117
 118 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 119                                   struct cfg80211_internal_bss *bss)
 120 {
 121         lockdep_assert_held(&rdev->bss_lock);
 122
 123         if (!list_empty(&bss->hidden_list)) {
 124                 /*
 125                  * don't remove the beacon entry if it has
 126                  * probe responses associated with it
 127                  */
 128                 if (!bss->pub.hidden_beacon_bss)
 129                         return false;
 130                 /*
 131                  * if it's a probe response entry break its
 132                  * link to the other entries in the group
 133                  */
 134                 list_del_init(&bss->hidden_list);
 135         }
 136
 137         list_del_init(&bss->list);
 138         rb_erase(&bss->rbn, &rdev->bss_tree);
 139         bss_ref_put(rdev, bss);
 140         return true;
 141 }
 142
 143 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 144                                   unsigned long expire_time)
 145 {
 146         struct cfg80211_internal_bss *bss, *tmp;
 147         bool expired = false;
 148
 149         lockdep_assert_held(&rdev->bss_lock);
 150
 151         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
 152                 if (atomic_read(&bss->hold))
 153                         continue;
 154                 if (!time_after(expire_time, bss->ts))
 155                         continue;
 156
 157                 if (__cfg80211_unlink_bss(rdev, bss))
 158                         expired = true;
 159         }
 160
 161         if (expired)
 162                 rdev->bss_generation++;
 163 }
 164
 165 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 166                            bool send_message)
 167 {
 168         struct cfg80211_scan_request *request;
 169         struct wireless_dev *wdev;
 170         struct sk_buff *msg;
 171 #ifdef CONFIG_CFG80211_WEXT
 172         union iwreq_data wrqu;
 173 #endif
 174
 175         ASSERT_RTNL();
 176
 177         if (rdev->scan_msg) {
 178                 nl80211_send_scan_result(rdev, rdev->scan_msg);
 179                 rdev->scan_msg = NULL;
 180                 return;
 181         }
 182
 183         request = rdev->scan_req;
 184         if (!request)
 185                 return;
 186
 187         wdev = request->wdev;
 188
 189         /*
 190          * This must be before sending the other events!
 191          * Otherwise, wpa_supplicant gets completely confused with
 192          * wext events.
 193          */
 194         if (wdev->netdev)
 195                 cfg80211_sme_scan_done(wdev->netdev);
 196
 197         if (!request->aborted &&
 198             request->flags & NL80211_SCAN_FLAG_FLUSH) {
 199                 /* flush entries from previous scans */
 200                 spin_lock_bh(&rdev->bss_lock);
 201                 __cfg80211_bss_expire(rdev, request->scan_start);
 202                 spin_unlock_bh(&rdev->bss_lock);
 203         }
 204
 205         msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
 206
 207 #ifdef CONFIG_CFG80211_WEXT
 208         if (wdev->netdev && !request->aborted) {
 209                 memset(&wrqu, 0, sizeof(wrqu));
 210
 211                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 212         }
 213 #endif
 214
 215         if (wdev->netdev)
 216                 dev_put(wdev->netdev);
 217
 218         rdev->scan_req = NULL;
 219         kfree(request);
 220
 221         if (!send_message)
 222                 rdev->scan_msg = msg;
 223         else
 224                 nl80211_send_scan_result(rdev, msg);
 225 }
 226
 227 void __cfg80211_scan_done(struct work_struct *wk)
 228 {
 229         struct cfg80211_registered_device *rdev;
 230
 231         rdev = container_of(wk, struct cfg80211_registered_device,
 232                             scan_done_wk);
 233
 234         rtnl_lock();
 235         ___cfg80211_scan_done(rdev, true);
 236         rtnl_unlock();
 237 }
 238
 239 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 240 {
 241         trace_cfg80211_scan_done(request, aborted);
 242         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
 243
 244         request->aborted = aborted;
 245         request->notified = true;
 246         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
 247 }
 248 EXPORT_SYMBOL(cfg80211_scan_done);
 249
 250 void __cfg80211_sched_scan_results(struct work_struct *wk)
 251 {
 252         struct cfg80211_registered_device *rdev;
 253         struct cfg80211_sched_scan_request *request;
 254
 255         rdev = container_of(wk, struct cfg80211_registered_device,
 256                             sched_scan_results_wk);
 257
 258         rtnl_lock();
 259
 260         request = rtnl_dereference(rdev->sched_scan_req);
 261
 262         /* we don't have sched_scan_req anymore if the scan is stopping */
 263         if (request) {
 264                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 265                         /* flush entries from previous scans */
 266                         spin_lock_bh(&rdev->bss_lock);
 267                         __cfg80211_bss_expire(rdev, request->scan_start);
 268                         spin_unlock_bh(&rdev->bss_lock);
 269                         request->scan_start =
 270                                 jiffies + msecs_to_jiffies(request->interval);
 271                 }
 272                 nl80211_send_sched_scan_results(rdev, request->dev);
 273         }
 274
 275         rtnl_unlock();
 276 }
 277
 278 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 279 {
 280         trace_cfg80211_sched_scan_results(wiphy);
 281         /* ignore if we're not scanning */
 282
 283         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
 284                 queue_work(cfg80211_wq,
 285                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
 286 }
 287 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 288
 289 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
 290 {
 291         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 292
 293         ASSERT_RTNL();
 294
 295         trace_cfg80211_sched_scan_stopped(wiphy);
 296
 297         __cfg80211_stop_sched_scan(rdev, true);
 298 }
 299 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 300
 301 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 302 {
 303         rtnl_lock();
 304         cfg80211_sched_scan_stopped_rtnl(wiphy);
 305         rtnl_unlock();
 306 }
 307 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 308
 309 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 310                                bool driver_initiated)
 311 {
 312         struct cfg80211_sched_scan_request *sched_scan_req;
 313         struct net_device *dev;
 314
 315         ASSERT_RTNL();
 316
 317         if (!rdev->sched_scan_req)
 318                 return -ENOENT;
 319
 320         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
 321         dev = sched_scan_req->dev;
 322
 323         if (!driver_initiated) {
 324                 int err = rdev_sched_scan_stop(rdev, dev);
 325                 if (err)
 326                         return err;
 327         }
 328
 329         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 330
 331         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
 332         kfree_rcu(sched_scan_req, rcu_head);
 333
 334         return 0;
 335 }
 336
 337 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 338                       unsigned long age_secs)
 339 {
 340         struct cfg80211_internal_bss *bss;
 341         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 342
 343         spin_lock_bh(&rdev->bss_lock);
 344         list_for_each_entry(bss, &rdev->bss_list, list)
 345                 bss->ts -= age_jiffies;
 346         spin_unlock_bh(&rdev->bss_lock);
 347 }
 348
 349 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 350 {
 351         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 352 }
 353
 354 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 355 {
 356         while (len > 2 && ies[0] != eid) {
 357                 len -= ies[1] + 2;
 358                 ies += ies[1] + 2;
 359         }
 360         if (len < 2)
 361                 return NULL;
 362         if (len < 2 + ies[1])
 363                 return NULL;
 364         return ies;
 365 }
 366 EXPORT_SYMBOL(cfg80211_find_ie);
 367
 368 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 369                                   const u8 *ies, int len)
 370 {
 371         struct ieee80211_vendor_ie *ie;
 372         const u8 *pos = ies, *end = ies + len;
 373         int ie_oui;
 374
 375         while (pos < end) {
 376                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 377                                        end - pos);
 378                 if (!pos)
 379                         return NULL;
 380
 381                 ie = (struct ieee80211_vendor_ie *)pos;
 382
 383                 /* make sure we can access ie->len */
 384                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 385
 386                 if (ie->len < sizeof(*ie))
 387                         goto cont;
 388
 389                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 390                 if (ie_oui == oui && ie->oui_type == oui_type)
 391                         return pos;
 392 cont:
 393                 pos += 2 + ie->len;
 394         }
 395         return NULL;
 396 }
 397 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 398
 399 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 400                    const u8 *ssid, size_t ssid_len)
 401 {
 402         const struct cfg80211_bss_ies *ies;
 403         const u8 *ssidie;
 404
 405         if (bssid && !ether_addr_equal(a->bssid, bssid))
 406                 return false;
 407
 408         if (!ssid)
 409                 return true;
 410
 411         ies = rcu_access_pointer(a->ies);
 412         if (!ies)
 413                 return false;
 414         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 415         if (!ssidie)
 416                 return false;
 417         if (ssidie[1] != ssid_len)
 418                 return false;
 419         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 420 }
 421
 422 /**
 423  * enum bss_compare_mode - BSS compare mode
 424  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 425  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 426  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 427  */
 428 enum bss_compare_mode {
 429         BSS_CMP_REGULAR,
 430         BSS_CMP_HIDE_ZLEN,
 431         BSS_CMP_HIDE_NUL,
 432 };
 433
 434 static int cmp_bss(struct cfg80211_bss *a,
 435                    struct cfg80211_bss *b,
 436                    enum bss_compare_mode mode)
 437 {
 438         const struct cfg80211_bss_ies *a_ies, *b_ies;
 439         const u8 *ie1 = NULL;
 440         const u8 *ie2 = NULL;
 441         int i, r;
 442
 443         if (a->channel != b->channel)
 444                 return b->channel->center_freq - a->channel->center_freq;
 445
 446         a_ies = rcu_access_pointer(a->ies);
 447         if (!a_ies)
 448                 return -1;
 449         b_ies = rcu_access_pointer(b->ies);
 450         if (!b_ies)
 451                 return 1;
 452
 453         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 454                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 455                                        a_ies->data, a_ies->len);
 456         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 457                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 458                                        b_ies->data, b_ies->len);
 459         if (ie1 && ie2) {
 460                 int mesh_id_cmp;
 461
 462                 if (ie1[1] == ie2[1])
 463                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 464                 else
 465                         mesh_id_cmp = ie2[1] - ie1[1];
 466
 467                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 468                                        a_ies->data, a_ies->len);
 469                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 470                                        b_ies->data, b_ies->len);
 471                 if (ie1 && ie2) {
 472                         if (mesh_id_cmp)
 473                                 return mesh_id_cmp;
 474                         if (ie1[1] != ie2[1])
 475                                 return ie2[1] - ie1[1];
 476                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 477                 }
 478         }
 479
 480         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 481         if (r)
 482                 return r;
 483
 484         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 485         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 486
 487         if (!ie1 && !ie2)
 488                 return 0;
 489
 490         /*
 491          * Note that with "hide_ssid", the function returns a match if
 492          * the already-present BSS ("b") is a hidden SSID beacon for
 493          * the new BSS ("a").
 494          */
 495
 496         /* sort missing IE before (left of) present IE */
 497         if (!ie1)
 498                 return -1;
 499         if (!ie2)
 500                 return 1;
 501
 502         switch (mode) {
 503         case BSS_CMP_HIDE_ZLEN:
 504                 /*
 505                  * In ZLEN mode we assume the BSS entry we're
 506                  * looking for has a zero-length SSID. So if
 507                  * the one we're looking at right now has that,
 508                  * return 0. Otherwise, return the difference
 509                  * in length, but since we're looking for the
 510                  * 0-length it's really equivalent to returning
 511                  * the length of the one we're looking at.
 512                  *
 513                  * No content comparison is needed as we assume
 514                  * the content length is zero.
 515                  */
 516                 return ie2[1];
 517         case BSS_CMP_REGULAR:
 518         default:
 519                 /* sort by length first, then by contents */
 520                 if (ie1[1] != ie2[1])
 521                         return ie2[1] - ie1[1];
 522                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 523         case BSS_CMP_HIDE_NUL:
 524                 if (ie1[1] != ie2[1])
 525                         return ie2[1] - ie1[1];
 526                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 527                 for (i = 0; i < ie2[1]; i++)
 528                         if (ie2[i + 2])
 529                                 return -1;
 530                 return 0;
 531         }
 532 }
 533
 534 /* Returned bss is reference counted and must be cleaned up appropriately. */
 535 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 536                                       struct ieee80211_channel *channel,
 537                                       const u8 *bssid,
 538                                       const u8 *ssid, size_t ssid_len,
 539                                       u16 capa_mask, u16 capa_val)
 540 {
 541         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 542         struct cfg80211_internal_bss *bss, *res = NULL;
 543         unsigned long now = jiffies;
 544
 545         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 546                                capa_val);
 547
 548         spin_lock_bh(&rdev->bss_lock);
 549
 550         list_for_each_entry(bss, &rdev->bss_list, list) {
 551                 if ((bss->pub.capability & capa_mask) != capa_val)
 552                         continue;
 553                 if (channel && bss->pub.channel != channel)
 554                         continue;
 555                 if (!is_valid_ether_addr(bss->pub.bssid))
 556                         continue;
 557                 /* Don't get expired BSS structs */
 558                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 559                     !atomic_read(&bss->hold))
 560                         continue;
 561                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 562                         res = bss;
 563                         bss_ref_get(rdev, res);
 564                         break;
 565                 }
 566         }
 567
 568         spin_unlock_bh(&rdev->bss_lock);
 569         if (!res)
 570                 return NULL;
 571         trace_cfg80211_return_bss(&res->pub);
 572         return &res->pub;
 573 }
 574 EXPORT_SYMBOL(cfg80211_get_bss);
 575
 576 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 577                           struct cfg80211_internal_bss *bss)
 578 {
 579         struct rb_node **p = &rdev->bss_tree.rb_node;
 580         struct rb_node *parent = NULL;
 581         struct cfg80211_internal_bss *tbss;
 582         int cmp;
 583
 584         while (*p) {
 585                 parent = *p;
 586                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 587
 588                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 589
 590                 if (WARN_ON(!cmp)) {
 591                         /* will sort of leak this BSS */
 592                         return;
 593                 }
 594
 595                 if (cmp < 0)
 596                         p = &(*p)->rb_left;
 597                 else
 598                         p = &(*p)->rb_right;
 599         }
 600
 601         rb_link_node(&bss->rbn, parent, p);
 602         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 603 }
 604
 605 static struct cfg80211_internal_bss *
 606 rb_find_bss(struct cfg80211_registered_device *rdev,
 607             struct cfg80211_internal_bss *res,
 608             enum bss_compare_mode mode)
 609 {
 610         struct rb_node *n = rdev->bss_tree.rb_node;
 611         struct cfg80211_internal_bss *bss;
 612         int r;
 613
 614         while (n) {
 615                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 616                 r = cmp_bss(&res->pub, &bss->pub, mode);
 617
 618                 if (r == 0)
 619                         return bss;
 620                 else if (r < 0)
 621                         n = n->rb_left;
 622                 else
 623                         n = n->rb_right;
 624         }
 625
 626         return NULL;
 627 }
 628
 629 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 630                                    struct cfg80211_internal_bss *new)
 631 {
 632         const struct cfg80211_bss_ies *ies;
 633         struct cfg80211_internal_bss *bss;
 634         const u8 *ie;
 635         int i, ssidlen;
 636         u8 fold = 0;
 637
 638         ies = rcu_access_pointer(new->pub.beacon_ies);
 639         if (WARN_ON(!ies))
 640                 return false;
 641
 642         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 643         if (!ie) {
 644                 /* nothing to do */
 645                 return true;
 646         }
 647
 648         ssidlen = ie[1];
 649         for (i = 0; i < ssidlen; i++)
 650                 fold |= ie[2 + i];
 651
 652         if (fold) {
 653                 /* not a hidden SSID */
 654                 return true;
 655         }
 656
 657         /* This is the bad part ... */
 658
 659         list_for_each_entry(bss, &rdev->bss_list, list) {
 660                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 661                         continue;
 662                 if (bss->pub.channel != new->pub.channel)
 663                         continue;
 664                 if (bss->pub.scan_width != new->pub.scan_width)
 665                         continue;
 666                 if (rcu_access_pointer(bss->pub.beacon_ies))
 667                         continue;
 668                 ies = rcu_access_pointer(bss->pub.ies);
 669                 if (!ies)
 670                         continue;
 671                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 672                 if (!ie)
 673                         continue;
 674                 if (ssidlen && ie[1] != ssidlen)
 675                         continue;
 676                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 677                         continue;
 678                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 679                         list_del(&bss->hidden_list);
 680                 /* combine them */
 681                 list_add(&bss->hidden_list, &new->hidden_list);
 682                 bss->pub.hidden_beacon_bss = &new->pub;
 683                 new->refcount += bss->refcount;
 684                 rcu_assign_pointer(bss->pub.beacon_ies,
 685                                    new->pub.beacon_ies);
 686         }
 687
 688         return true;
 689 }
 690
 691 /* Returned bss is reference counted and must be cleaned up appropriately. */
 692 static struct cfg80211_internal_bss *
 693 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 694                     struct cfg80211_internal_bss *tmp,
 695                     bool signal_valid)
 696 {
 697         struct cfg80211_internal_bss *found = NULL;
 698
 699         if (WARN_ON(!tmp->pub.channel))
 700                 return NULL;
 701
 702         tmp->ts = jiffies;
 703
 704         spin_lock_bh(&rdev->bss_lock);
 705
 706         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 707                 spin_unlock_bh(&rdev->bss_lock);
 708                 return NULL;
 709         }
 710
 711         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 712
 713         if (found) {
 714                 /* Update IEs */
 715                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 716                         const struct cfg80211_bss_ies *old;
 717
 718                         old = rcu_access_pointer(found->pub.proberesp_ies);
 719
 720                         rcu_assign_pointer(found->pub.proberesp_ies,
 721                                            tmp->pub.proberesp_ies);
 722                         /* Override possible earlier Beacon frame IEs */
 723                         rcu_assign_pointer(found->pub.ies,
 724                                            tmp->pub.proberesp_ies);
 725                         if (old)
 726                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 727                                           rcu_head);
 728                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 729                         const struct cfg80211_bss_ies *old;
 730                         struct cfg80211_internal_bss *bss;
 731
 732                         if (found->pub.hidden_beacon_bss &&
 733                             !list_empty(&found->hidden_list)) {
 734                                 const struct cfg80211_bss_ies *f;
 735
 736                                 /*
 737                                  * The found BSS struct is one of the probe
 738                                  * response members of a group, but we're
 739                                  * receiving a beacon (beacon_ies in the tmp
 740                                  * bss is used). This can only mean that the
 741                                  * AP changed its beacon from not having an
 742                                  * SSID to showing it, which is confusing so
 743                                  * drop this information.
 744                                  */
 745
 746                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 747                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 748                                           rcu_head);
 749                                 goto drop;
 750                         }
 751
 752                         old = rcu_access_pointer(found->pub.beacon_ies);
 753
 754                         rcu_assign_pointer(found->pub.beacon_ies,
 755                                            tmp->pub.beacon_ies);
 756
 757                         /* Override IEs if they were from a beacon before */
 758                         if (old == rcu_access_pointer(found->pub.ies))
 759                                 rcu_assign_pointer(found->pub.ies,
 760                                                    tmp->pub.beacon_ies);
 761
 762                         /* Assign beacon IEs to all sub entries */
 763                         list_for_each_entry(bss, &found->hidden_list,
 764                                             hidden_list) {
 765                                 const struct cfg80211_bss_ies *ies;
 766
 767                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 768                                 WARN_ON(ies != old);
 769
 770                                 rcu_assign_pointer(bss->pub.beacon_ies,
 771                                                    tmp->pub.beacon_ies);
 772                         }
 773
 774                         if (old)
 775                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 776                                           rcu_head);
 777                 }
 778
 779                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 780                 /*
 781                  * don't update the signal if beacon was heard on
 782                  * adjacent channel.
 783                  */
 784                 if (signal_valid)
 785                         found->pub.signal = tmp->pub.signal;
 786                 found->pub.capability = tmp->pub.capability;
 787                 found->ts = tmp->ts;
 788         } else {
 789                 struct cfg80211_internal_bss *new;
 790                 struct cfg80211_internal_bss *hidden;
 791                 struct cfg80211_bss_ies *ies;
 792
 793                 /*
 794                  * create a copy -- the "res" variable that is passed in
 795                  * is allocated on the stack since it's not needed in the
 796                  * more common case of an update
 797                  */
 798                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 799                               GFP_ATOMIC);
 800                 if (!new) {
 801                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 802                         if (ies)
 803                                 kfree_rcu(ies, rcu_head);
 804                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 805                         if (ies)
 806                                 kfree_rcu(ies, rcu_head);
 807                         goto drop;
 808                 }
 809                 memcpy(new, tmp, sizeof(*new));
 810                 new->refcount = 1;
 811                 INIT_LIST_HEAD(&new->hidden_list);
 812
 813                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 814                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 815                         if (!hidden)
 816                                 hidden = rb_find_bss(rdev, tmp,
 817                                                      BSS_CMP_HIDE_NUL);
 818                         if (hidden) {
 819                                 new->pub.hidden_beacon_bss = &hidden->pub;
 820                                 list_add(&new->hidden_list,
 821                                          &hidden->hidden_list);
 822                                 hidden->refcount++;
 823                                 rcu_assign_pointer(new->pub.beacon_ies,
 824                                                    hidden->pub.beacon_ies);
 825                         }
 826                 } else {
 827                         /*
 828                          * Ok so we found a beacon, and don't have an entry. If
 829                          * it's a beacon with hidden SSID, we might be in for an
 830                          * expensive search for any probe responses that should
 831                          * be grouped with this beacon for updates ...
 832                          */
 833                         if (!cfg80211_combine_bsses(rdev, new)) {
 834                                 kfree(new);
 835                                 goto drop;
 836                         }
 837                 }
 838
 839                 list_add_tail(&new->list, &rdev->bss_list);
 840                 rb_insert_bss(rdev, new);
 841                 found = new;
 842         }
 843
 844         rdev->bss_generation++;
 845         bss_ref_get(rdev, found);
 846         spin_unlock_bh(&rdev->bss_lock);
 847
 848         return found;
 849  drop:
 850         spin_unlock_bh(&rdev->bss_lock);
 851         return NULL;
 852 }
 853
 854 static struct ieee80211_channel *
 855 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 856                          struct ieee80211_channel *channel)
 857 {
 858         const u8 *tmp;
 859         u32 freq;
 860         int channel_number = -1;
 861
 862         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 863         if (tmp && tmp[1] == 1) {
 864                 channel_number = tmp[2];
 865         } else {
 866                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 867                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 868                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 869
 870                         channel_number = htop->primary_chan;
 871                 }
 872         }
 873
 874         if (channel_number < 0)
 875                 return channel;
 876
 877         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 878         channel = ieee80211_get_channel(wiphy, freq);
 879         if (!channel)
 880                 return NULL;
 881         if (channel->flags & IEEE80211_CHAN_DISABLED)
 882                 return NULL;
 883         return channel;
 884 }
 885
 886 /* Returned bss is reference counted and must be cleaned up appropriately. */
 887 struct cfg80211_bss*
 888 cfg80211_inform_bss_width(struct wiphy *wiphy,
 889                           struct ieee80211_channel *rx_channel,
 890                           enum nl80211_bss_scan_width scan_width,
 891                           enum cfg80211_bss_frame_type ftype,
 892                           const u8 *bssid, u64 tsf, u16 capability,
 893                           u16 beacon_interval, const u8 *ie, size_t ielen,
 894                           s32 signal, gfp_t gfp)
 895 {
 896         struct cfg80211_bss_ies *ies;
 897         struct ieee80211_channel *channel;
 898         struct cfg80211_internal_bss tmp = {}, *res;
 899         bool signal_valid;
 900
 901         if (WARN_ON(!wiphy))
 902                 return NULL;
 903
 904         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 905                         (signal < 0 || signal > 100)))
 906                 return NULL;
 907
 908         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 909         if (!channel)
 910                 return NULL;
 911
 912         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 913         tmp.pub.channel = channel;
 914         tmp.pub.scan_width = scan_width;
 915         tmp.pub.signal = signal;
 916         tmp.pub.beacon_interval = beacon_interval;
 917         tmp.pub.capability = capability;
 918         /*
 919          * If we do not know here whether the IEs are from a Beacon or Probe
 920          * Response frame, we need to pick one of the options and only use it
 921          * with the driver that does not provide the full Beacon/Probe Response
 922          * frame. Use Beacon frame pointer to avoid indicating that this should
 923          * override the IEs pointer should we have received an earlier
 924          * indication of Probe Response data.
 925          */
 926         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 927         if (!ies)
 928                 return NULL;
 929         ies->len = ielen;
 930         ies->tsf = tsf;
 931         ies->from_beacon = false;
 932         memcpy(ies->data, ie, ielen);
 933
 934         switch (ftype) {
 935         case CFG80211_BSS_FTYPE_BEACON:
 936                 ies->from_beacon = true;
 937                 /* fall through to assign */
 938         case CFG80211_BSS_FTYPE_UNKNOWN:
 939                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 940                 break;
 941         case CFG80211_BSS_FTYPE_PRESP:
 942                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 943                 break;
 944         }
 945         rcu_assign_pointer(tmp.pub.ies, ies);
 946
 947         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
 948                 wiphy->max_adj_channel_rssi_comp;
 949         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
 950         if (!res)
 951                 return NULL;
 952
 953         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 954                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 955
 956         trace_cfg80211_return_bss(&res->pub);
 957         /* cfg80211_bss_update gives us a referenced result */
 958         return &res->pub;
 959 }
 960 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 961
 962 /* Returned bss is reference counted and must be cleaned up appropriately. */
 963 struct cfg80211_bss *
 964 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 965                                 struct ieee80211_channel *rx_channel,
 966                                 enum nl80211_bss_scan_width scan_width,
 967                                 struct ieee80211_mgmt *mgmt, size_t len,
 968                                 s32 signal, gfp_t gfp)
 969 {
 970         struct cfg80211_internal_bss tmp = {}, *res;
 971         struct cfg80211_bss_ies *ies;
 972         struct ieee80211_channel *channel;
 973         bool signal_valid;
 974         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 975                                       u.probe_resp.variable);
 976
 977         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 978                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 979
 980         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
 981                                               len, signal);
 982
 983         if (WARN_ON(!mgmt))
 984                 return NULL;
 985
 986         if (WARN_ON(!wiphy))
 987                 return NULL;
 988
 989         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 990                     (signal < 0 || signal > 100)))
 991                 return NULL;
 992
 993         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 994                 return NULL;
 995
 996         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 997                                            ielen, rx_channel);
 998         if (!channel)
 999                 return NULL;
1000
1001         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1002         if (!ies)
1003                 return NULL;
1004         ies->len = ielen;
1005         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1006         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1007         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1008
1009         if (ieee80211_is_probe_resp(mgmt->frame_control))
1010                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1011         else
1012                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1013         rcu_assign_pointer(tmp.pub.ies, ies);
1014
1015         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1016         tmp.pub.channel = channel;
1017         tmp.pub.scan_width = scan_width;
1018         tmp.pub.signal = signal;
1019         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1020         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1021
1022         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
1023                 wiphy->max_adj_channel_rssi_comp;
1024         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1025         if (!res)
1026                 return NULL;
1027
1028         if (res->pub.capability & WLAN_CAPABILITY_ESS)
1029                 regulatory_hint_found_beacon(wiphy, channel, gfp);
1030
1031         trace_cfg80211_return_bss(&res->pub);
1032         /* cfg80211_bss_update gives us a referenced result */
1033         return &res->pub;
1034 }
1035 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1036
1037 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1038 {
1039         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1040         struct cfg80211_internal_bss *bss;
1041
1042         if (!pub)
1043                 return;
1044
1045         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1046
1047         spin_lock_bh(&rdev->bss_lock);
1048         bss_ref_get(rdev, bss);
1049         spin_unlock_bh(&rdev->bss_lock);
1050 }
1051 EXPORT_SYMBOL(cfg80211_ref_bss);
1052
1053 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1054 {
1055         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1056         struct cfg80211_internal_bss *bss;
1057
1058         if (!pub)
1059                 return;
1060
1061         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1062
1063         spin_lock_bh(&rdev->bss_lock);
1064         bss_ref_put(rdev, bss);
1065         spin_unlock_bh(&rdev->bss_lock);
1066 }
1067 EXPORT_SYMBOL(cfg80211_put_bss);
1068
1069 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1070 {
1071         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1072         struct cfg80211_internal_bss *bss;
1073
1074         if (WARN_ON(!pub))
1075                 return;
1076
1077         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1078
1079         spin_lock_bh(&rdev->bss_lock);
1080         if (!list_empty(&bss->list)) {
1081                 if (__cfg80211_unlink_bss(rdev, bss))
1082                         rdev->bss_generation++;
1083         }
1084         spin_unlock_bh(&rdev->bss_lock);
1085 }
1086 EXPORT_SYMBOL(cfg80211_unlink_bss);
1087
1088 #ifdef CONFIG_CFG80211_WEXT
1089 static struct cfg80211_registered_device *
1090 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1091 {
1092         struct cfg80211_registered_device *rdev;
1093         struct net_device *dev;
1094
1095         ASSERT_RTNL();
1096
1097         dev = dev_get_by_index(net, ifindex);
1098         if (!dev)
1099                 return ERR_PTR(-ENODEV);
1100         if (dev->ieee80211_ptr)
1101                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1102         else
1103                 rdev = ERR_PTR(-ENODEV);
1104         dev_put(dev);
1105         return rdev;
1106 }
1107
1108 int cfg80211_wext_siwscan(struct net_device *dev,
1109                           struct iw_request_info *info,
1110                           union iwreq_data *wrqu, char *extra)
1111 {
1112         struct cfg80211_registered_device *rdev;
1113         struct wiphy *wiphy;
1114         struct iw_scan_req *wreq = NULL;
1115         struct cfg80211_scan_request *creq = NULL;
1116         int i, err, n_channels = 0;
1117         enum ieee80211_band band;
1118
1119         if (!netif_running(dev))
1120                 return -ENETDOWN;
1121
1122         if (wrqu->data.length == sizeof(struct iw_scan_req))
1123                 wreq = (struct iw_scan_req *)extra;
1124
1125         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1126
1127         if (IS_ERR(rdev))
1128                 return PTR_ERR(rdev);
1129
1130         if (rdev->scan_req || rdev->scan_msg) {
1131                 err = -EBUSY;
1132                 goto out;
1133         }
1134
1135         wiphy = &rdev->wiphy;
1136
1137         /* Determine number of channels, needed to allocate creq */
1138         if (wreq && wreq->num_channels)
1139                 n_channels = wreq->num_channels;
1140         else
1141                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1142
1143         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1144                        n_channels * sizeof(void *),
1145                        GFP_ATOMIC);
1146         if (!creq) {
1147                 err = -ENOMEM;
1148                 goto out;
1149         }
1150
1151         creq->wiphy = wiphy;
1152         creq->wdev = dev->ieee80211_ptr;
1153         /* SSIDs come after channels */
1154         creq->ssids = (void *)&creq->channels[n_channels];
1155         creq->n_channels = n_channels;
1156         creq->n_ssids = 1;
1157         creq->scan_start = jiffies;
1158
1159         /* translate "Scan on frequencies" request */
1160         i = 0;
1161         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1162                 int j;
1163
1164                 if (!wiphy->bands[band])
1165                         continue;
1166
1167                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1168                         /* ignore disabled channels */
1169                         if (wiphy->bands[band]->channels[j].flags &
1170                                                 IEEE80211_CHAN_DISABLED)
1171                                 continue;
1172
1173                         /* If we have a wireless request structure and the
1174                          * wireless request specifies frequencies, then search
1175                          * for the matching hardware channel.
1176                          */
1177                         if (wreq && wreq->num_channels) {
1178                                 int k;
1179                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1180                                 for (k = 0; k < wreq->num_channels; k++) {
1181                                         struct iw_freq *freq =
1182                                                 &wreq->channel_list[k];
1183                                         int wext_freq =
1184                                                 cfg80211_wext_freq(freq);
1185
1186                                         if (wext_freq == wiphy_freq)
1187                                                 goto wext_freq_found;
1188                                 }
1189                                 goto wext_freq_not_found;
1190                         }
1191
1192                 wext_freq_found:
1193                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1194                         i++;
1195                 wext_freq_not_found: ;
1196                 }
1197         }
1198         /* No channels found? */
1199         if (!i) {
1200                 err = -EINVAL;
1201                 goto out;
1202         }
1203
1204         /* Set real number of channels specified in creq->channels[] */
1205         creq->n_channels = i;
1206
1207         /* translate "Scan for SSID" request */
1208         if (wreq) {
1209                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1210                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1211                                 err = -EINVAL;
1212                                 goto out;
1213                         }
1214                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1215                         creq->ssids[0].ssid_len = wreq->essid_len;
1216                 }
1217                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1218                         creq->n_ssids = 0;
1219         }
1220
1221         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1222                 if (wiphy->bands[i])
1223                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1224
1225         rdev->scan_req = creq;
1226         err = rdev_scan(rdev, creq);
1227         if (err) {
1228                 rdev->scan_req = NULL;
1229                 /* creq will be freed below */
1230         } else {
1231                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1232                 /* creq now owned by driver */
1233                 creq = NULL;
1234                 dev_hold(dev);
1235         }
1236  out:
1237         kfree(creq);
1238         return err;
1239 }
1240 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1241
1242 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1243                                    const struct cfg80211_bss_ies *ies,
1244                                    char **current_ev, char *end_buf)
1245 {
1246         const u8 *pos, *end, *next;
1247         struct iw_event iwe;
1248
1249         if (!ies)
1250                 return;
1251
1252         /*
1253          * If needed, fragment the IEs buffer (at IE boundaries) into short
1254          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1255          */
1256         pos = ies->data;
1257         end = pos + ies->len;
1258
1259         while (end - pos > IW_GENERIC_IE_MAX) {
1260                 next = pos + 2 + pos[1];
1261                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1262                         next = next + 2 + next[1];
1263
1264                 memset(&iwe, 0, sizeof(iwe));
1265                 iwe.cmd = IWEVGENIE;
1266                 iwe.u.data.length = next - pos;
1267                 *current_ev = iwe_stream_add_point(info, *current_ev,
1268                                                    end_buf, &iwe,
1269                                                    (void *)pos);
1270
1271                 pos = next;
1272         }
1273
1274         if (end > pos) {
1275                 memset(&iwe, 0, sizeof(iwe));
1276                 iwe.cmd = IWEVGENIE;
1277                 iwe.u.data.length = end - pos;
1278                 *current_ev = iwe_stream_add_point(info, *current_ev,
1279                                                    end_buf, &iwe,
1280                                                    (void *)pos);
1281         }
1282 }
1283
1284 static char *
1285 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1286               struct cfg80211_internal_bss *bss, char *current_ev,
1287               char *end_buf)
1288 {
1289         const struct cfg80211_bss_ies *ies;
1290         struct iw_event iwe;
1291         const u8 *ie;
1292         u8 *buf, *cfg, *p;
1293         int rem, i, sig;
1294         bool ismesh = false;
1295
1296         memset(&iwe, 0, sizeof(iwe));
1297         iwe.cmd = SIOCGIWAP;
1298         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1299         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1300         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1301                                           IW_EV_ADDR_LEN);
1302
1303         memset(&iwe, 0, sizeof(iwe));
1304         iwe.cmd = SIOCGIWFREQ;
1305         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1306         iwe.u.freq.e = 0;
1307         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1308                                           IW_EV_FREQ_LEN);
1309
1310         memset(&iwe, 0, sizeof(iwe));
1311         iwe.cmd = SIOCGIWFREQ;
1312         iwe.u.freq.m = bss->pub.channel->center_freq;
1313         iwe.u.freq.e = 6;
1314         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1315                                           IW_EV_FREQ_LEN);
1316
1317         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1318                 memset(&iwe, 0, sizeof(iwe));
1319                 iwe.cmd = IWEVQUAL;
1320                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1321                                      IW_QUAL_NOISE_INVALID |
1322                                      IW_QUAL_QUAL_UPDATED;
1323                 switch (wiphy->signal_type) {
1324                 case CFG80211_SIGNAL_TYPE_MBM:
1325                         sig = bss->pub.signal / 100;
1326                         iwe.u.qual.level = sig;
1327                         iwe.u.qual.updated |= IW_QUAL_DBM;
1328                         if (sig < -110)         /* rather bad */
1329                                 sig = -110;
1330                         else if (sig > -40)     /* perfect */
1331                                 sig = -40;
1332                         /* will give a range of 0 .. 70 */
1333                         iwe.u.qual.qual = sig + 110;
1334                         break;
1335                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1336                         iwe.u.qual.level = bss->pub.signal;
1337                         /* will give range 0 .. 100 */
1338                         iwe.u.qual.qual = bss->pub.signal;
1339                         break;
1340                 default:
1341                         /* not reached */
1342                         break;
1343                 }
1344                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1345                                                   &iwe, IW_EV_QUAL_LEN);
1346         }
1347
1348         memset(&iwe, 0, sizeof(iwe));
1349         iwe.cmd = SIOCGIWENCODE;
1350         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1351                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1352         else
1353                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1354         iwe.u.data.length = 0;
1355         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1356                                           &iwe, "");
1357
1358         rcu_read_lock();
1359         ies = rcu_dereference(bss->pub.ies);
1360         rem = ies->len;
1361         ie = ies->data;
1362
1363         while (rem >= 2) {
1364                 /* invalid data */
1365                 if (ie[1] > rem - 2)
1366                         break;
1367
1368                 switch (ie[0]) {
1369                 case WLAN_EID_SSID:
1370                         memset(&iwe, 0, sizeof(iwe));
1371                         iwe.cmd = SIOCGIWESSID;
1372                         iwe.u.data.length = ie[1];
1373                         iwe.u.data.flags = 1;
1374                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1375                                                           &iwe, (u8 *)ie + 2);
1376                         break;
1377                 case WLAN_EID_MESH_ID:
1378                         memset(&iwe, 0, sizeof(iwe));
1379                         iwe.cmd = SIOCGIWESSID;
1380                         iwe.u.data.length = ie[1];
1381                         iwe.u.data.flags = 1;
1382                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1383                                                           &iwe, (u8 *)ie + 2);
1384                         break;
1385                 case WLAN_EID_MESH_CONFIG:
1386                         ismesh = true;
1387                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1388                                 break;
1389                         buf = kmalloc(50, GFP_ATOMIC);
1390                         if (!buf)
1391                                 break;
1392                         cfg = (u8 *)ie + 2;
1393                         memset(&iwe, 0, sizeof(iwe));
1394                         iwe.cmd = IWEVCUSTOM;
1395                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1396                                 "0x%02X", cfg[0]);
1397                         iwe.u.data.length = strlen(buf);
1398                         current_ev = iwe_stream_add_point(info, current_ev,
1399                                                           end_buf,
1400                                                           &iwe, buf);
1401                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1402                                 cfg[1]);
1403                         iwe.u.data.length = strlen(buf);
1404                         current_ev = iwe_stream_add_point(info, current_ev,
1405                                                           end_buf,
1406                                                           &iwe, buf);
1407                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1408                                 cfg[2]);
1409                         iwe.u.data.length = strlen(buf);
1410                         current_ev = iwe_stream_add_point(info, current_ev,
1411                                                           end_buf,
1412                                                           &iwe, buf);
1413                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1414                         iwe.u.data.length = strlen(buf);
1415                         current_ev = iwe_stream_add_point(info, current_ev,
1416                                                           end_buf,
1417                                                           &iwe, buf);
1418                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1419                         iwe.u.data.length = strlen(buf);
1420                         current_ev = iwe_stream_add_point(info, current_ev,
1421                                                           end_buf,
1422                                                           &iwe, buf);
1423                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1424                         iwe.u.data.length = strlen(buf);
1425                         current_ev = iwe_stream_add_point(info, current_ev,
1426                                                           end_buf,
1427                                                           &iwe, buf);
1428                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1429                         iwe.u.data.length = strlen(buf);
1430                         current_ev = iwe_stream_add_point(info, current_ev,
1431                                                           end_buf,
1432                                                           &iwe, buf);
1433                         kfree(buf);
1434                         break;
1435                 case WLAN_EID_SUPP_RATES:
1436                 case WLAN_EID_EXT_SUPP_RATES:
1437                         /* display all supported rates in readable format */
1438                         p = current_ev + iwe_stream_lcp_len(info);
1439
1440                         memset(&iwe, 0, sizeof(iwe));
1441                         iwe.cmd = SIOCGIWRATE;
1442                         /* Those two flags are ignored... */
1443                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1444
1445                         for (i = 0; i < ie[1]; i++) {
1446                                 iwe.u.bitrate.value =
1447                                         ((ie[i + 2] & 0x7f) * 500000);
1448                                 p = iwe_stream_add_value(info, current_ev, p,
1449                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1450                         }
1451                         current_ev = p;
1452                         break;
1453                 }
1454                 rem -= ie[1] + 2;
1455                 ie += ie[1] + 2;
1456         }
1457
1458         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1459             ismesh) {
1460                 memset(&iwe, 0, sizeof(iwe));
1461                 iwe.cmd = SIOCGIWMODE;
1462                 if (ismesh)
1463                         iwe.u.mode = IW_MODE_MESH;
1464                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1465                         iwe.u.mode = IW_MODE_MASTER;
1466                 else
1467                         iwe.u.mode = IW_MODE_ADHOC;
1468                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1469                                                   &iwe, IW_EV_UINT_LEN);
1470         }
1471
1472         buf = kmalloc(31, GFP_ATOMIC);
1473         if (buf) {
1474                 memset(&iwe, 0, sizeof(iwe));
1475                 iwe.cmd = IWEVCUSTOM;
1476                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1477                 iwe.u.data.length = strlen(buf);
1478                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1479                                                   &iwe, buf);
1480                 memset(&iwe, 0, sizeof(iwe));
1481                 iwe.cmd = IWEVCUSTOM;
1482                 sprintf(buf, " Last beacon: %ums ago",
1483                         elapsed_jiffies_msecs(bss->ts));
1484                 iwe.u.data.length = strlen(buf);
1485                 current_ev = iwe_stream_add_point(info, current_ev,
1486                                                   end_buf, &iwe, buf);
1487                 kfree(buf);
1488         }
1489
1490         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1491         rcu_read_unlock();
1492
1493         return current_ev;
1494 }
1495
1496
1497 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1498                                   struct iw_request_info *info,
1499                                   char *buf, size_t len)
1500 {
1501         char *current_ev = buf;
1502         char *end_buf = buf + len;
1503         struct cfg80211_internal_bss *bss;
1504
1505         spin_lock_bh(&rdev->bss_lock);
1506         cfg80211_bss_expire(rdev);
1507
1508         list_for_each_entry(bss, &rdev->bss_list, list) {
1509                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1510                         spin_unlock_bh(&rdev->bss_lock);
1511                         return -E2BIG;
1512                 }
1513                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1514                                            current_ev, end_buf);
1515         }
1516         spin_unlock_bh(&rdev->bss_lock);
1517         return current_ev - buf;
1518 }
1519
1520
1521 int cfg80211_wext_giwscan(struct net_device *dev,
1522                           struct iw_request_info *info,
1523                           struct iw_point *data, char *extra)
1524 {
1525         struct cfg80211_registered_device *rdev;
1526         int res;
1527
1528         if (!netif_running(dev))
1529                 return -ENETDOWN;
1530
1531         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1532
1533         if (IS_ERR(rdev))
1534                 return PTR_ERR(rdev);
1535
1536         if (rdev->scan_req || rdev->scan_msg)
1537                 return -EAGAIN;
1538
1539         res = ieee80211_scan_results(rdev, info, extra, data->length);
1540         data->length = 0;
1541         if (res >= 0) {
1542                 data->length = res;
1543                 res = 0;
1544         }
1545
1546         return res;
1547 }
1548 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1549 #endif