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_rtnl(struct wiphy *wiphy)
 288 {
 289         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 290
 291         ASSERT_RTNL();
 292
 293         trace_cfg80211_sched_scan_stopped(wiphy);
 294
 295         __cfg80211_stop_sched_scan(rdev, true);
 296 }
 297 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 298
 299 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 300 {
 301         rtnl_lock();
 302         cfg80211_sched_scan_stopped_rtnl(wiphy);
 303         rtnl_unlock();
 304 }
 305 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 306
 307 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 308                                bool driver_initiated)
 309 {
 310         struct net_device *dev;
 311
 312         ASSERT_RTNL();
 313
 314         if (!rdev->sched_scan_req)
 315                 return -ENOENT;
 316
 317         dev = rdev->sched_scan_req->dev;
 318
 319         if (!driver_initiated) {
 320                 int err = rdev_sched_scan_stop(rdev, dev);
 321                 if (err)
 322                         return err;
 323         }
 324
 325         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 326
 327         kfree(rdev->sched_scan_req);
 328         rdev->sched_scan_req = NULL;
 329
 330         return 0;
 331 }
 332
 333 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
 334                       unsigned long age_secs)
 335 {
 336         struct cfg80211_internal_bss *bss;
 337         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 338
 339         spin_lock_bh(&dev->bss_lock);
 340         list_for_each_entry(bss, &dev->bss_list, list)
 341                 bss->ts -= age_jiffies;
 342         spin_unlock_bh(&dev->bss_lock);
 343 }
 344
 345 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
 346 {
 347         __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 348 }
 349
 350 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 351 {
 352         while (len > 2 && ies[0] != eid) {
 353                 len -= ies[1] + 2;
 354                 ies += ies[1] + 2;
 355         }
 356         if (len < 2)
 357                 return NULL;
 358         if (len < 2 + ies[1])
 359                 return NULL;
 360         return ies;
 361 }
 362 EXPORT_SYMBOL(cfg80211_find_ie);
 363
 364 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 365                                   const u8 *ies, int len)
 366 {
 367         struct ieee80211_vendor_ie *ie;
 368         const u8 *pos = ies, *end = ies + len;
 369         int ie_oui;
 370
 371         while (pos < end) {
 372                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 373                                        end - pos);
 374                 if (!pos)
 375                         return NULL;
 376
 377                 ie = (struct ieee80211_vendor_ie *)pos;
 378
 379                 /* make sure we can access ie->len */
 380                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 381
 382                 if (ie->len < sizeof(*ie))
 383                         goto cont;
 384
 385                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 386                 if (ie_oui == oui && ie->oui_type == oui_type)
 387                         return pos;
 388 cont:
 389                 pos += 2 + ie->len;
 390         }
 391         return NULL;
 392 }
 393 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 394
 395 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 396                    const u8 *ssid, size_t ssid_len)
 397 {
 398         const struct cfg80211_bss_ies *ies;
 399         const u8 *ssidie;
 400
 401         if (bssid && !ether_addr_equal(a->bssid, bssid))
 402                 return false;
 403
 404         if (!ssid)
 405                 return true;
 406
 407         ies = rcu_access_pointer(a->ies);
 408         if (!ies)
 409                 return false;
 410         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 411         if (!ssidie)
 412                 return false;
 413         if (ssidie[1] != ssid_len)
 414                 return false;
 415         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 416 }
 417
 418 /**
 419  * enum bss_compare_mode - BSS compare mode
 420  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 421  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 422  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 423  */
 424 enum bss_compare_mode {
 425         BSS_CMP_REGULAR,
 426         BSS_CMP_HIDE_ZLEN,
 427         BSS_CMP_HIDE_NUL,
 428 };
 429
 430 static int cmp_bss(struct cfg80211_bss *a,
 431                    struct cfg80211_bss *b,
 432                    enum bss_compare_mode mode)
 433 {
 434         const struct cfg80211_bss_ies *a_ies, *b_ies;
 435         const u8 *ie1 = NULL;
 436         const u8 *ie2 = NULL;
 437         int i, r;
 438
 439         if (a->channel != b->channel)
 440                 return b->channel->center_freq - a->channel->center_freq;
 441
 442         a_ies = rcu_access_pointer(a->ies);
 443         if (!a_ies)
 444                 return -1;
 445         b_ies = rcu_access_pointer(b->ies);
 446         if (!b_ies)
 447                 return 1;
 448
 449         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 450                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 451                                        a_ies->data, a_ies->len);
 452         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 453                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 454                                        b_ies->data, b_ies->len);
 455         if (ie1 && ie2) {
 456                 int mesh_id_cmp;
 457
 458                 if (ie1[1] == ie2[1])
 459                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 460                 else
 461                         mesh_id_cmp = ie2[1] - ie1[1];
 462
 463                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 464                                        a_ies->data, a_ies->len);
 465                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 466                                        b_ies->data, b_ies->len);
 467                 if (ie1 && ie2) {
 468                         if (mesh_id_cmp)
 469                                 return mesh_id_cmp;
 470                         if (ie1[1] != ie2[1])
 471                                 return ie2[1] - ie1[1];
 472                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 473                 }
 474         }
 475
 476         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 477         if (r)
 478                 return r;
 479
 480         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 481         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 482
 483         if (!ie1 && !ie2)
 484                 return 0;
 485
 486         /*
 487          * Note that with "hide_ssid", the function returns a match if
 488          * the already-present BSS ("b") is a hidden SSID beacon for
 489          * the new BSS ("a").
 490          */
 491
 492         /* sort missing IE before (left of) present IE */
 493         if (!ie1)
 494                 return -1;
 495         if (!ie2)
 496                 return 1;
 497
 498         switch (mode) {
 499         case BSS_CMP_HIDE_ZLEN:
 500                 /*
 501                  * In ZLEN mode we assume the BSS entry we're
 502                  * looking for has a zero-length SSID. So if
 503                  * the one we're looking at right now has that,
 504                  * return 0. Otherwise, return the difference
 505                  * in length, but since we're looking for the
 506                  * 0-length it's really equivalent to returning
 507                  * the length of the one we're looking at.
 508                  *
 509                  * No content comparison is needed as we assume
 510                  * the content length is zero.
 511                  */
 512                 return ie2[1];
 513         case BSS_CMP_REGULAR:
 514         default:
 515                 /* sort by length first, then by contents */
 516                 if (ie1[1] != ie2[1])
 517                         return ie2[1] - ie1[1];
 518                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 519         case BSS_CMP_HIDE_NUL:
 520                 if (ie1[1] != ie2[1])
 521                         return ie2[1] - ie1[1];
 522                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 523                 for (i = 0; i < ie2[1]; i++)
 524                         if (ie2[i + 2])
 525                                 return -1;
 526                 return 0;
 527         }
 528 }
 529
 530 /* Returned bss is reference counted and must be cleaned up appropriately. */
 531 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 532                                       struct ieee80211_channel *channel,
 533                                       const u8 *bssid,
 534                                       const u8 *ssid, size_t ssid_len,
 535                                       u16 capa_mask, u16 capa_val)
 536 {
 537         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 538         struct cfg80211_internal_bss *bss, *res = NULL;
 539         unsigned long now = jiffies;
 540
 541         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 542                                capa_val);
 543
 544         spin_lock_bh(&dev->bss_lock);
 545
 546         list_for_each_entry(bss, &dev->bss_list, list) {
 547                 if ((bss->pub.capability & capa_mask) != capa_val)
 548                         continue;
 549                 if (channel && bss->pub.channel != channel)
 550                         continue;
 551                 /* Don't get expired BSS structs */
 552                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 553                     !atomic_read(&bss->hold))
 554                         continue;
 555                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 556                         res = bss;
 557                         bss_ref_get(dev, res);
 558                         break;
 559                 }
 560         }
 561
 562         spin_unlock_bh(&dev->bss_lock);
 563         if (!res)
 564                 return NULL;
 565         trace_cfg80211_return_bss(&res->pub);
 566         return &res->pub;
 567 }
 568 EXPORT_SYMBOL(cfg80211_get_bss);
 569
 570 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 571                           struct cfg80211_internal_bss *bss)
 572 {
 573         struct rb_node **p = &dev->bss_tree.rb_node;
 574         struct rb_node *parent = NULL;
 575         struct cfg80211_internal_bss *tbss;
 576         int cmp;
 577
 578         while (*p) {
 579                 parent = *p;
 580                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 581
 582                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 583
 584                 if (WARN_ON(!cmp)) {
 585                         /* will sort of leak this BSS */
 586                         return;
 587                 }
 588
 589                 if (cmp < 0)
 590                         p = &(*p)->rb_left;
 591                 else
 592                         p = &(*p)->rb_right;
 593         }
 594
 595         rb_link_node(&bss->rbn, parent, p);
 596         rb_insert_color(&bss->rbn, &dev->bss_tree);
 597 }
 598
 599 static struct cfg80211_internal_bss *
 600 rb_find_bss(struct cfg80211_registered_device *dev,
 601             struct cfg80211_internal_bss *res,
 602             enum bss_compare_mode mode)
 603 {
 604         struct rb_node *n = dev->bss_tree.rb_node;
 605         struct cfg80211_internal_bss *bss;
 606         int r;
 607
 608         while (n) {
 609                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 610                 r = cmp_bss(&res->pub, &bss->pub, mode);
 611
 612                 if (r == 0)
 613                         return bss;
 614                 else if (r < 0)
 615                         n = n->rb_left;
 616                 else
 617                         n = n->rb_right;
 618         }
 619
 620         return NULL;
 621 }
 622
 623 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
 624                                    struct cfg80211_internal_bss *new)
 625 {
 626         const struct cfg80211_bss_ies *ies;
 627         struct cfg80211_internal_bss *bss;
 628         const u8 *ie;
 629         int i, ssidlen;
 630         u8 fold = 0;
 631
 632         ies = rcu_access_pointer(new->pub.beacon_ies);
 633         if (WARN_ON(!ies))
 634                 return false;
 635
 636         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 637         if (!ie) {
 638                 /* nothing to do */
 639                 return true;
 640         }
 641
 642         ssidlen = ie[1];
 643         for (i = 0; i < ssidlen; i++)
 644                 fold |= ie[2 + i];
 645
 646         if (fold) {
 647                 /* not a hidden SSID */
 648                 return true;
 649         }
 650
 651         /* This is the bad part ... */
 652
 653         list_for_each_entry(bss, &dev->bss_list, list) {
 654                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 655                         continue;
 656                 if (bss->pub.channel != new->pub.channel)
 657                         continue;
 658                 if (bss->pub.scan_width != new->pub.scan_width)
 659                         continue;
 660                 if (rcu_access_pointer(bss->pub.beacon_ies))
 661                         continue;
 662                 ies = rcu_access_pointer(bss->pub.ies);
 663                 if (!ies)
 664                         continue;
 665                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 666                 if (!ie)
 667                         continue;
 668                 if (ssidlen && ie[1] != ssidlen)
 669                         continue;
 670                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 671                         continue;
 672                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 673                         list_del(&bss->hidden_list);
 674                 /* combine them */
 675                 list_add(&bss->hidden_list, &new->hidden_list);
 676                 bss->pub.hidden_beacon_bss = &new->pub;
 677                 new->refcount += bss->refcount;
 678                 rcu_assign_pointer(bss->pub.beacon_ies,
 679                                    new->pub.beacon_ies);
 680         }
 681
 682         return true;
 683 }
 684
 685 /* Returned bss is reference counted and must be cleaned up appropriately. */
 686 static struct cfg80211_internal_bss *
 687 cfg80211_bss_update(struct cfg80211_registered_device *dev,
 688                     struct cfg80211_internal_bss *tmp,
 689                     bool signal_valid)
 690 {
 691         struct cfg80211_internal_bss *found = NULL;
 692
 693         if (WARN_ON(!tmp->pub.channel))
 694                 return NULL;
 695
 696         tmp->ts = jiffies;
 697
 698         spin_lock_bh(&dev->bss_lock);
 699
 700         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 701                 spin_unlock_bh(&dev->bss_lock);
 702                 return NULL;
 703         }
 704
 705         found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
 706
 707         if (found) {
 708                 /* Update IEs */
 709                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 710                         const struct cfg80211_bss_ies *old;
 711
 712                         old = rcu_access_pointer(found->pub.proberesp_ies);
 713
 714                         rcu_assign_pointer(found->pub.proberesp_ies,
 715                                            tmp->pub.proberesp_ies);
 716                         /* Override possible earlier Beacon frame IEs */
 717                         rcu_assign_pointer(found->pub.ies,
 718                                            tmp->pub.proberesp_ies);
 719                         if (old)
 720                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 721                                           rcu_head);
 722                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 723                         const struct cfg80211_bss_ies *old;
 724                         struct cfg80211_internal_bss *bss;
 725
 726                         if (found->pub.hidden_beacon_bss &&
 727                             !list_empty(&found->hidden_list)) {
 728                                 const struct cfg80211_bss_ies *f;
 729
 730                                 /*
 731                                  * The found BSS struct is one of the probe
 732                                  * response members of a group, but we're
 733                                  * receiving a beacon (beacon_ies in the tmp
 734                                  * bss is used). This can only mean that the
 735                                  * AP changed its beacon from not having an
 736                                  * SSID to showing it, which is confusing so
 737                                  * drop this information.
 738                                  */
 739
 740                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 741                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 742                                           rcu_head);
 743                                 goto drop;
 744                         }
 745
 746                         old = rcu_access_pointer(found->pub.beacon_ies);
 747
 748                         rcu_assign_pointer(found->pub.beacon_ies,
 749                                            tmp->pub.beacon_ies);
 750
 751                         /* Override IEs if they were from a beacon before */
 752                         if (old == rcu_access_pointer(found->pub.ies))
 753                                 rcu_assign_pointer(found->pub.ies,
 754                                                    tmp->pub.beacon_ies);
 755
 756                         /* Assign beacon IEs to all sub entries */
 757                         list_for_each_entry(bss, &found->hidden_list,
 758                                             hidden_list) {
 759                                 const struct cfg80211_bss_ies *ies;
 760
 761                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 762                                 WARN_ON(ies != old);
 763
 764                                 rcu_assign_pointer(bss->pub.beacon_ies,
 765                                                    tmp->pub.beacon_ies);
 766                         }
 767
 768                         if (old)
 769                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 770                                           rcu_head);
 771                 }
 772
 773                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 774                 /*
 775                  * don't update the signal if beacon was heard on
 776                  * adjacent channel.
 777                  */
 778                 if (signal_valid)
 779                         found->pub.signal = tmp->pub.signal;
 780                 found->pub.capability = tmp->pub.capability;
 781                 found->ts = tmp->ts;
 782         } else {
 783                 struct cfg80211_internal_bss *new;
 784                 struct cfg80211_internal_bss *hidden;
 785                 struct cfg80211_bss_ies *ies;
 786
 787                 /*
 788                  * create a copy -- the "res" variable that is passed in
 789                  * is allocated on the stack since it's not needed in the
 790                  * more common case of an update
 791                  */
 792                 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
 793                               GFP_ATOMIC);
 794                 if (!new) {
 795                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 796                         if (ies)
 797                                 kfree_rcu(ies, rcu_head);
 798                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 799                         if (ies)
 800                                 kfree_rcu(ies, rcu_head);
 801                         goto drop;
 802                 }
 803                 memcpy(new, tmp, sizeof(*new));
 804                 new->refcount = 1;
 805                 INIT_LIST_HEAD(&new->hidden_list);
 806
 807                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 808                         hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
 809                         if (!hidden)
 810                                 hidden = rb_find_bss(dev, tmp,
 811                                                      BSS_CMP_HIDE_NUL);
 812                         if (hidden) {
 813                                 new->pub.hidden_beacon_bss = &hidden->pub;
 814                                 list_add(&new->hidden_list,
 815                                          &hidden->hidden_list);
 816                                 hidden->refcount++;
 817                                 rcu_assign_pointer(new->pub.beacon_ies,
 818                                                    hidden->pub.beacon_ies);
 819                         }
 820                 } else {
 821                         /*
 822                          * Ok so we found a beacon, and don't have an entry. If
 823                          * it's a beacon with hidden SSID, we might be in for an
 824                          * expensive search for any probe responses that should
 825                          * be grouped with this beacon for updates ...
 826                          */
 827                         if (!cfg80211_combine_bsses(dev, new)) {
 828                                 kfree(new);
 829                                 goto drop;
 830                         }
 831                 }
 832
 833                 list_add_tail(&new->list, &dev->bss_list);
 834                 rb_insert_bss(dev, new);
 835                 found = new;
 836         }
 837
 838         dev->bss_generation++;
 839         bss_ref_get(dev, found);
 840         spin_unlock_bh(&dev->bss_lock);
 841
 842         return found;
 843  drop:
 844         spin_unlock_bh(&dev->bss_lock);
 845         return NULL;
 846 }
 847
 848 static struct ieee80211_channel *
 849 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 850                          struct ieee80211_channel *channel)
 851 {
 852         const u8 *tmp;
 853         u32 freq;
 854         int channel_number = -1;
 855
 856         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 857         if (tmp && tmp[1] == 1) {
 858                 channel_number = tmp[2];
 859         } else {
 860                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 861                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 862                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 863
 864                         channel_number = htop->primary_chan;
 865                 }
 866         }
 867
 868         if (channel_number < 0)
 869                 return channel;
 870
 871         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 872         channel = ieee80211_get_channel(wiphy, freq);
 873         if (!channel)
 874                 return NULL;
 875         if (channel->flags & IEEE80211_CHAN_DISABLED)
 876                 return NULL;
 877         return channel;
 878 }
 879
 880 /* Returned bss is reference counted and must be cleaned up appropriately. */
 881 struct cfg80211_bss*
 882 cfg80211_inform_bss_width(struct wiphy *wiphy,
 883                           struct ieee80211_channel *rx_channel,
 884                           enum nl80211_bss_scan_width scan_width,
 885                           const u8 *bssid, u64 tsf, u16 capability,
 886                           u16 beacon_interval, const u8 *ie, size_t ielen,
 887                           s32 signal, gfp_t gfp)
 888 {
 889         struct cfg80211_bss_ies *ies;
 890         struct ieee80211_channel *channel;
 891         struct cfg80211_internal_bss tmp = {}, *res;
 892
 893         if (WARN_ON(!wiphy))
 894                 return NULL;
 895
 896         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 897                         (signal < 0 || signal > 100)))
 898                 return NULL;
 899
 900         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 901         if (!channel)
 902                 return NULL;
 903
 904         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 905         tmp.pub.channel = channel;
 906         tmp.pub.scan_width = scan_width;
 907         tmp.pub.signal = signal;
 908         tmp.pub.beacon_interval = beacon_interval;
 909         tmp.pub.capability = capability;
 910         /*
 911          * Since we do not know here whether the IEs are from a Beacon or Probe
 912          * Response frame, we need to pick one of the options and only use it
 913          * with the driver that does not provide the full Beacon/Probe Response
 914          * frame. Use Beacon frame pointer to avoid indicating that this should
 915          * override the IEs pointer should we have received an earlier
 916          * indication of Probe Response data.
 917          */
 918         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 919         if (!ies)
 920                 return NULL;
 921         ies->len = ielen;
 922         ies->tsf = tsf;
 923         memcpy(ies->data, ie, ielen);
 924
 925         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 926         rcu_assign_pointer(tmp.pub.ies, ies);
 927
 928         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp,
 929                                   rx_channel == channel);
 930         if (!res)
 931                 return NULL;
 932
 933         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 934                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 935
 936         trace_cfg80211_return_bss(&res->pub);
 937         /* cfg80211_bss_update gives us a referenced result */
 938         return &res->pub;
 939 }
 940 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 941
 942 /* Returned bss is reference counted and must be cleaned up appropriately. */
 943 struct cfg80211_bss *
 944 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 945                                 struct ieee80211_channel *rx_channel,
 946                                 enum nl80211_bss_scan_width scan_width,
 947                                 struct ieee80211_mgmt *mgmt, size_t len,
 948                                 s32 signal, gfp_t gfp)
 949 {
 950         struct cfg80211_internal_bss tmp = {}, *res;
 951         struct cfg80211_bss_ies *ies;
 952         struct ieee80211_channel *channel;
 953         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 954                                       u.probe_resp.variable);
 955
 956         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 957                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 958
 959         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
 960                                               len, signal);
 961
 962         if (WARN_ON(!mgmt))
 963                 return NULL;
 964
 965         if (WARN_ON(!wiphy))
 966                 return NULL;
 967
 968         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 969                     (signal < 0 || signal > 100)))
 970                 return NULL;
 971
 972         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 973                 return NULL;
 974
 975         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 976                                            ielen, rx_channel);
 977         if (!channel)
 978                 return NULL;
 979
 980         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 981         if (!ies)
 982                 return NULL;
 983         ies->len = ielen;
 984         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 985         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 986
 987         if (ieee80211_is_probe_resp(mgmt->frame_control))
 988                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 989         else
 990                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 991         rcu_assign_pointer(tmp.pub.ies, ies);
 992
 993         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 994         tmp.pub.channel = channel;
 995         tmp.pub.scan_width = scan_width;
 996         tmp.pub.signal = signal;
 997         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 998         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 999
1000         res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp,
1001                                   rx_channel == channel);
1002         if (!res)
1003                 return NULL;
1004
1005         if (res->pub.capability & WLAN_CAPABILITY_ESS)
1006                 regulatory_hint_found_beacon(wiphy, channel, gfp);
1007
1008         trace_cfg80211_return_bss(&res->pub);
1009         /* cfg80211_bss_update gives us a referenced result */
1010         return &res->pub;
1011 }
1012 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1013
1014 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1015 {
1016         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1017         struct cfg80211_internal_bss *bss;
1018
1019         if (!pub)
1020                 return;
1021
1022         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1023
1024         spin_lock_bh(&dev->bss_lock);
1025         bss_ref_get(dev, bss);
1026         spin_unlock_bh(&dev->bss_lock);
1027 }
1028 EXPORT_SYMBOL(cfg80211_ref_bss);
1029
1030 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1031 {
1032         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1033         struct cfg80211_internal_bss *bss;
1034
1035         if (!pub)
1036                 return;
1037
1038         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1039
1040         spin_lock_bh(&dev->bss_lock);
1041         bss_ref_put(dev, bss);
1042         spin_unlock_bh(&dev->bss_lock);
1043 }
1044 EXPORT_SYMBOL(cfg80211_put_bss);
1045
1046 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1047 {
1048         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1049         struct cfg80211_internal_bss *bss;
1050
1051         if (WARN_ON(!pub))
1052                 return;
1053
1054         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1055
1056         spin_lock_bh(&dev->bss_lock);
1057         if (!list_empty(&bss->list)) {
1058                 if (__cfg80211_unlink_bss(dev, bss))
1059                         dev->bss_generation++;
1060         }
1061         spin_unlock_bh(&dev->bss_lock);
1062 }
1063 EXPORT_SYMBOL(cfg80211_unlink_bss);
1064
1065 #ifdef CONFIG_CFG80211_WEXT
1066 static struct cfg80211_registered_device *
1067 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1068 {
1069         struct cfg80211_registered_device *rdev;
1070         struct net_device *dev;
1071
1072         ASSERT_RTNL();
1073
1074         dev = dev_get_by_index(net, ifindex);
1075         if (!dev)
1076                 return ERR_PTR(-ENODEV);
1077         if (dev->ieee80211_ptr)
1078                 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
1079         else
1080                 rdev = ERR_PTR(-ENODEV);
1081         dev_put(dev);
1082         return rdev;
1083 }
1084
1085 int cfg80211_wext_siwscan(struct net_device *dev,
1086                           struct iw_request_info *info,
1087                           union iwreq_data *wrqu, char *extra)
1088 {
1089         struct cfg80211_registered_device *rdev;
1090         struct wiphy *wiphy;
1091         struct iw_scan_req *wreq = NULL;
1092         struct cfg80211_scan_request *creq = NULL;
1093         int i, err, n_channels = 0;
1094         enum ieee80211_band band;
1095
1096         if (!netif_running(dev))
1097                 return -ENETDOWN;
1098
1099         if (wrqu->data.length == sizeof(struct iw_scan_req))
1100                 wreq = (struct iw_scan_req *)extra;
1101
1102         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1103
1104         if (IS_ERR(rdev))
1105                 return PTR_ERR(rdev);
1106
1107         if (rdev->scan_req || rdev->scan_msg) {
1108                 err = -EBUSY;
1109                 goto out;
1110         }
1111
1112         wiphy = &rdev->wiphy;
1113
1114         /* Determine number of channels, needed to allocate creq */
1115         if (wreq && wreq->num_channels)
1116                 n_channels = wreq->num_channels;
1117         else
1118                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1119
1120         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1121                        n_channels * sizeof(void *),
1122                        GFP_ATOMIC);
1123         if (!creq) {
1124                 err = -ENOMEM;
1125                 goto out;
1126         }
1127
1128         creq->wiphy = wiphy;
1129         creq->wdev = dev->ieee80211_ptr;
1130         /* SSIDs come after channels */
1131         creq->ssids = (void *)&creq->channels[n_channels];
1132         creq->n_channels = n_channels;
1133         creq->n_ssids = 1;
1134         creq->scan_start = jiffies;
1135
1136         /* translate "Scan on frequencies" request */
1137         i = 0;
1138         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1139                 int j;
1140
1141                 if (!wiphy->bands[band])
1142                         continue;
1143
1144                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1145                         /* ignore disabled channels */
1146                         if (wiphy->bands[band]->channels[j].flags &
1147                                                 IEEE80211_CHAN_DISABLED)
1148                                 continue;
1149
1150                         /* If we have a wireless request structure and the
1151                          * wireless request specifies frequencies, then search
1152                          * for the matching hardware channel.
1153                          */
1154                         if (wreq && wreq->num_channels) {
1155                                 int k;
1156                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1157                                 for (k = 0; k < wreq->num_channels; k++) {
1158                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1159                                         if (wext_freq == wiphy_freq)
1160                                                 goto wext_freq_found;
1161                                 }
1162                                 goto wext_freq_not_found;
1163                         }
1164
1165                 wext_freq_found:
1166                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1167                         i++;
1168                 wext_freq_not_found: ;
1169                 }
1170         }
1171         /* No channels found? */
1172         if (!i) {
1173                 err = -EINVAL;
1174                 goto out;
1175         }
1176
1177         /* Set real number of channels specified in creq->channels[] */
1178         creq->n_channels = i;
1179
1180         /* translate "Scan for SSID" request */
1181         if (wreq) {
1182                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1183                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1184                                 err = -EINVAL;
1185                                 goto out;
1186                         }
1187                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1188                         creq->ssids[0].ssid_len = wreq->essid_len;
1189                 }
1190                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1191                         creq->n_ssids = 0;
1192         }
1193
1194         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1195                 if (wiphy->bands[i])
1196                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1197
1198         rdev->scan_req = creq;
1199         err = rdev_scan(rdev, creq);
1200         if (err) {
1201                 rdev->scan_req = NULL;
1202                 /* creq will be freed below */
1203         } else {
1204                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1205                 /* creq now owned by driver */
1206                 creq = NULL;
1207                 dev_hold(dev);
1208         }
1209  out:
1210         kfree(creq);
1211         return err;
1212 }
1213 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1214
1215 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1216                                    const struct cfg80211_bss_ies *ies,
1217                                    char **current_ev, char *end_buf)
1218 {
1219         const u8 *pos, *end, *next;
1220         struct iw_event iwe;
1221
1222         if (!ies)
1223                 return;
1224
1225         /*
1226          * If needed, fragment the IEs buffer (at IE boundaries) into short
1227          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1228          */
1229         pos = ies->data;
1230         end = pos + ies->len;
1231
1232         while (end - pos > IW_GENERIC_IE_MAX) {
1233                 next = pos + 2 + pos[1];
1234                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1235                         next = next + 2 + next[1];
1236
1237                 memset(&iwe, 0, sizeof(iwe));
1238                 iwe.cmd = IWEVGENIE;
1239                 iwe.u.data.length = next - pos;
1240                 *current_ev = iwe_stream_add_point(info, *current_ev,
1241                                                    end_buf, &iwe,
1242                                                    (void *)pos);
1243
1244                 pos = next;
1245         }
1246
1247         if (end > pos) {
1248                 memset(&iwe, 0, sizeof(iwe));
1249                 iwe.cmd = IWEVGENIE;
1250                 iwe.u.data.length = end - pos;
1251                 *current_ev = iwe_stream_add_point(info, *current_ev,
1252                                                    end_buf, &iwe,
1253                                                    (void *)pos);
1254         }
1255 }
1256
1257 static char *
1258 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1259               struct cfg80211_internal_bss *bss, char *current_ev,
1260               char *end_buf)
1261 {
1262         const struct cfg80211_bss_ies *ies;
1263         struct iw_event iwe;
1264         const u8 *ie;
1265         u8 *buf, *cfg, *p;
1266         int rem, i, sig;
1267         bool ismesh = false;
1268
1269         memset(&iwe, 0, sizeof(iwe));
1270         iwe.cmd = SIOCGIWAP;
1271         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1272         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1273         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1274                                           IW_EV_ADDR_LEN);
1275
1276         memset(&iwe, 0, sizeof(iwe));
1277         iwe.cmd = SIOCGIWFREQ;
1278         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1279         iwe.u.freq.e = 0;
1280         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1281                                           IW_EV_FREQ_LEN);
1282
1283         memset(&iwe, 0, sizeof(iwe));
1284         iwe.cmd = SIOCGIWFREQ;
1285         iwe.u.freq.m = bss->pub.channel->center_freq;
1286         iwe.u.freq.e = 6;
1287         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1288                                           IW_EV_FREQ_LEN);
1289
1290         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1291                 memset(&iwe, 0, sizeof(iwe));
1292                 iwe.cmd = IWEVQUAL;
1293                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1294                                      IW_QUAL_NOISE_INVALID |
1295                                      IW_QUAL_QUAL_UPDATED;
1296                 switch (wiphy->signal_type) {
1297                 case CFG80211_SIGNAL_TYPE_MBM:
1298                         sig = bss->pub.signal / 100;
1299                         iwe.u.qual.level = sig;
1300                         iwe.u.qual.updated |= IW_QUAL_DBM;
1301                         if (sig < -110)         /* rather bad */
1302                                 sig = -110;
1303                         else if (sig > -40)     /* perfect */
1304                                 sig = -40;
1305                         /* will give a range of 0 .. 70 */
1306                         iwe.u.qual.qual = sig + 110;
1307                         break;
1308                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1309                         iwe.u.qual.level = bss->pub.signal;
1310                         /* will give range 0 .. 100 */
1311                         iwe.u.qual.qual = bss->pub.signal;
1312                         break;
1313                 default:
1314                         /* not reached */
1315                         break;
1316                 }
1317                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1318                                                   &iwe, IW_EV_QUAL_LEN);
1319         }
1320
1321         memset(&iwe, 0, sizeof(iwe));
1322         iwe.cmd = SIOCGIWENCODE;
1323         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1324                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1325         else
1326                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1327         iwe.u.data.length = 0;
1328         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1329                                           &iwe, "");
1330
1331         rcu_read_lock();
1332         ies = rcu_dereference(bss->pub.ies);
1333         rem = ies->len;
1334         ie = ies->data;
1335
1336         while (rem >= 2) {
1337                 /* invalid data */
1338                 if (ie[1] > rem - 2)
1339                         break;
1340
1341                 switch (ie[0]) {
1342                 case WLAN_EID_SSID:
1343                         memset(&iwe, 0, sizeof(iwe));
1344                         iwe.cmd = SIOCGIWESSID;
1345                         iwe.u.data.length = ie[1];
1346                         iwe.u.data.flags = 1;
1347                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1348                                                           &iwe, (u8 *)ie + 2);
1349                         break;
1350                 case WLAN_EID_MESH_ID:
1351                         memset(&iwe, 0, sizeof(iwe));
1352                         iwe.cmd = SIOCGIWESSID;
1353                         iwe.u.data.length = ie[1];
1354                         iwe.u.data.flags = 1;
1355                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1356                                                           &iwe, (u8 *)ie + 2);
1357                         break;
1358                 case WLAN_EID_MESH_CONFIG:
1359                         ismesh = true;
1360                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1361                                 break;
1362                         buf = kmalloc(50, GFP_ATOMIC);
1363                         if (!buf)
1364                                 break;
1365                         cfg = (u8 *)ie + 2;
1366                         memset(&iwe, 0, sizeof(iwe));
1367                         iwe.cmd = IWEVCUSTOM;
1368                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1369                                 "0x%02X", cfg[0]);
1370                         iwe.u.data.length = strlen(buf);
1371                         current_ev = iwe_stream_add_point(info, current_ev,
1372                                                           end_buf,
1373                                                           &iwe, buf);
1374                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1375                                 cfg[1]);
1376                         iwe.u.data.length = strlen(buf);
1377                         current_ev = iwe_stream_add_point(info, current_ev,
1378                                                           end_buf,
1379                                                           &iwe, buf);
1380                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1381                                 cfg[2]);
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, "Synchronization ID: 0x%02X", cfg[3]);
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, "Authentication ID: 0x%02X", cfg[4]);
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, "Formation Info: 0x%02X", cfg[5]);
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, "Capabilities: 0x%02X", cfg[6]);
1402                         iwe.u.data.length = strlen(buf);
1403                         current_ev = iwe_stream_add_point(info, current_ev,
1404                                                           end_buf,
1405                                                           &iwe, buf);
1406                         kfree(buf);
1407                         break;
1408                 case WLAN_EID_SUPP_RATES:
1409                 case WLAN_EID_EXT_SUPP_RATES:
1410                         /* display all supported rates in readable format */
1411                         p = current_ev + iwe_stream_lcp_len(info);
1412
1413                         memset(&iwe, 0, sizeof(iwe));
1414                         iwe.cmd = SIOCGIWRATE;
1415                         /* Those two flags are ignored... */
1416                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1417
1418                         for (i = 0; i < ie[1]; i++) {
1419                                 iwe.u.bitrate.value =
1420                                         ((ie[i + 2] & 0x7f) * 500000);
1421                                 p = iwe_stream_add_value(info, current_ev, p,
1422                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1423                         }
1424                         current_ev = p;
1425                         break;
1426                 }
1427                 rem -= ie[1] + 2;
1428                 ie += ie[1] + 2;
1429         }
1430
1431         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1432             ismesh) {
1433                 memset(&iwe, 0, sizeof(iwe));
1434                 iwe.cmd = SIOCGIWMODE;
1435                 if (ismesh)
1436                         iwe.u.mode = IW_MODE_MESH;
1437                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1438                         iwe.u.mode = IW_MODE_MASTER;
1439                 else
1440                         iwe.u.mode = IW_MODE_ADHOC;
1441                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1442                                                   &iwe, IW_EV_UINT_LEN);
1443         }
1444
1445         buf = kmalloc(31, GFP_ATOMIC);
1446         if (buf) {
1447                 memset(&iwe, 0, sizeof(iwe));
1448                 iwe.cmd = IWEVCUSTOM;
1449                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1450                 iwe.u.data.length = strlen(buf);
1451                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1452                                                   &iwe, buf);
1453                 memset(&iwe, 0, sizeof(iwe));
1454                 iwe.cmd = IWEVCUSTOM;
1455                 sprintf(buf, " Last beacon: %ums ago",
1456                         elapsed_jiffies_msecs(bss->ts));
1457                 iwe.u.data.length = strlen(buf);
1458                 current_ev = iwe_stream_add_point(info, current_ev,
1459                                                   end_buf, &iwe, buf);
1460                 kfree(buf);
1461         }
1462
1463         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1464         rcu_read_unlock();
1465
1466         return current_ev;
1467 }
1468
1469
1470 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1471                                   struct iw_request_info *info,
1472                                   char *buf, size_t len)
1473 {
1474         char *current_ev = buf;
1475         char *end_buf = buf + len;
1476         struct cfg80211_internal_bss *bss;
1477
1478         spin_lock_bh(&dev->bss_lock);
1479         cfg80211_bss_expire(dev);
1480
1481         list_for_each_entry(bss, &dev->bss_list, list) {
1482                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1483                         spin_unlock_bh(&dev->bss_lock);
1484                         return -E2BIG;
1485                 }
1486                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1487                                            current_ev, end_buf);
1488         }
1489         spin_unlock_bh(&dev->bss_lock);
1490         return current_ev - buf;
1491 }
1492
1493
1494 int cfg80211_wext_giwscan(struct net_device *dev,
1495                           struct iw_request_info *info,
1496                           struct iw_point *data, char *extra)
1497 {
1498         struct cfg80211_registered_device *rdev;
1499         int res;
1500
1501         if (!netif_running(dev))
1502                 return -ENETDOWN;
1503
1504         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1505
1506         if (IS_ERR(rdev))
1507                 return PTR_ERR(rdev);
1508
1509         if (rdev->scan_req || rdev->scan_msg)
1510                 return -EAGAIN;
1511
1512         res = ieee80211_scan_results(rdev, info, extra, data->length);
1513         data->length = 0;
1514         if (res >= 0) {
1515                 data->length = res;
1516                 res = 0;
1517         }
1518
1519         return res;
1520 }
1521 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1522 #endif