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 *rdev,
  85                                struct cfg80211_internal_bss *bss)
  86 {
  87         lockdep_assert_held(&rdev->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 *rdev,
  99                                struct cfg80211_internal_bss *bss)
 100 {
 101         lockdep_assert_held(&rdev->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 *rdev,
 118                                   struct cfg80211_internal_bss *bss)
 119 {
 120         lockdep_assert_held(&rdev->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, &rdev->bss_tree);
 138         bss_ref_put(rdev, bss);
 139         return true;
 140 }
 141
 142 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 143                                   unsigned long expire_time)
 144 {
 145         struct cfg80211_internal_bss *bss, *tmp;
 146         bool expired = false;
 147
 148         lockdep_assert_held(&rdev->bss_lock);
 149
 150         list_for_each_entry_safe(bss, tmp, &rdev->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(rdev, bss))
 157                         expired = true;
 158         }
 159
 160         if (expired)
 161                 rdev->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_rdev(request->wiphy)->scan_req);
 242
 243         request->aborted = aborted;
 244         request->notified = true;
 245         queue_work(cfg80211_wq, &wiphy_to_rdev(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_rdev(wiphy)->sched_scan_req)
 282                 queue_work(cfg80211_wq,
 283                            &wiphy_to_rdev(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_rdev(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 *rdev,
 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(&rdev->bss_lock);
 340         list_for_each_entry(bss, &rdev->bss_list, list)
 341                 bss->ts -= age_jiffies;
 342         spin_unlock_bh(&rdev->bss_lock);
 343 }
 344
 345 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 346 {
 347         __cfg80211_bss_expire(rdev, 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 *rdev = wiphy_to_rdev(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(&rdev->bss_lock);
 545
 546         list_for_each_entry(bss, &rdev->bss_list, list) {
 547                 if ((bss->pub.capability & capa_mask) != capa_val)
 548                         continue;
 549                 if (channel && bss->pub.channel != channel)
 550                         continue;
 551                 if (!is_valid_ether_addr(bss->pub.bssid))
 552                         continue;
 553                 /* Don't get expired BSS structs */
 554                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 555                     !atomic_read(&bss->hold))
 556                         continue;
 557                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 558                         res = bss;
 559                         bss_ref_get(rdev, res);
 560                         break;
 561                 }
 562         }
 563
 564         spin_unlock_bh(&rdev->bss_lock);
 565         if (!res)
 566                 return NULL;
 567         trace_cfg80211_return_bss(&res->pub);
 568         return &res->pub;
 569 }
 570 EXPORT_SYMBOL(cfg80211_get_bss);
 571
 572 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 573                           struct cfg80211_internal_bss *bss)
 574 {
 575         struct rb_node **p = &rdev->bss_tree.rb_node;
 576         struct rb_node *parent = NULL;
 577         struct cfg80211_internal_bss *tbss;
 578         int cmp;
 579
 580         while (*p) {
 581                 parent = *p;
 582                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 583
 584                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 585
 586                 if (WARN_ON(!cmp)) {
 587                         /* will sort of leak this BSS */
 588                         return;
 589                 }
 590
 591                 if (cmp < 0)
 592                         p = &(*p)->rb_left;
 593                 else
 594                         p = &(*p)->rb_right;
 595         }
 596
 597         rb_link_node(&bss->rbn, parent, p);
 598         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 599 }
 600
 601 static struct cfg80211_internal_bss *
 602 rb_find_bss(struct cfg80211_registered_device *rdev,
 603             struct cfg80211_internal_bss *res,
 604             enum bss_compare_mode mode)
 605 {
 606         struct rb_node *n = rdev->bss_tree.rb_node;
 607         struct cfg80211_internal_bss *bss;
 608         int r;
 609
 610         while (n) {
 611                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 612                 r = cmp_bss(&res->pub, &bss->pub, mode);
 613
 614                 if (r == 0)
 615                         return bss;
 616                 else if (r < 0)
 617                         n = n->rb_left;
 618                 else
 619                         n = n->rb_right;
 620         }
 621
 622         return NULL;
 623 }
 624
 625 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 626                                    struct cfg80211_internal_bss *new)
 627 {
 628         const struct cfg80211_bss_ies *ies;
 629         struct cfg80211_internal_bss *bss;
 630         const u8 *ie;
 631         int i, ssidlen;
 632         u8 fold = 0;
 633
 634         ies = rcu_access_pointer(new->pub.beacon_ies);
 635         if (WARN_ON(!ies))
 636                 return false;
 637
 638         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 639         if (!ie) {
 640                 /* nothing to do */
 641                 return true;
 642         }
 643
 644         ssidlen = ie[1];
 645         for (i = 0; i < ssidlen; i++)
 646                 fold |= ie[2 + i];
 647
 648         if (fold) {
 649                 /* not a hidden SSID */
 650                 return true;
 651         }
 652
 653         /* This is the bad part ... */
 654
 655         list_for_each_entry(bss, &rdev->bss_list, list) {
 656                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 657                         continue;
 658                 if (bss->pub.channel != new->pub.channel)
 659                         continue;
 660                 if (bss->pub.scan_width != new->pub.scan_width)
 661                         continue;
 662                 if (rcu_access_pointer(bss->pub.beacon_ies))
 663                         continue;
 664                 ies = rcu_access_pointer(bss->pub.ies);
 665                 if (!ies)
 666                         continue;
 667                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 668                 if (!ie)
 669                         continue;
 670                 if (ssidlen && ie[1] != ssidlen)
 671                         continue;
 672                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 673                         continue;
 674                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 675                         list_del(&bss->hidden_list);
 676                 /* combine them */
 677                 list_add(&bss->hidden_list, &new->hidden_list);
 678                 bss->pub.hidden_beacon_bss = &new->pub;
 679                 new->refcount += bss->refcount;
 680                 rcu_assign_pointer(bss->pub.beacon_ies,
 681                                    new->pub.beacon_ies);
 682         }
 683
 684         return true;
 685 }
 686
 687 /* Returned bss is reference counted and must be cleaned up appropriately. */
 688 static struct cfg80211_internal_bss *
 689 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 690                     struct cfg80211_internal_bss *tmp,
 691                     bool signal_valid)
 692 {
 693         struct cfg80211_internal_bss *found = NULL;
 694
 695         if (WARN_ON(!tmp->pub.channel))
 696                 return NULL;
 697
 698         tmp->ts = jiffies;
 699
 700         spin_lock_bh(&rdev->bss_lock);
 701
 702         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 703                 spin_unlock_bh(&rdev->bss_lock);
 704                 return NULL;
 705         }
 706
 707         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 708
 709         if (found) {
 710                 /* Update IEs */
 711                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 712                         const struct cfg80211_bss_ies *old;
 713
 714                         old = rcu_access_pointer(found->pub.proberesp_ies);
 715
 716                         rcu_assign_pointer(found->pub.proberesp_ies,
 717                                            tmp->pub.proberesp_ies);
 718                         /* Override possible earlier Beacon frame IEs */
 719                         rcu_assign_pointer(found->pub.ies,
 720                                            tmp->pub.proberesp_ies);
 721                         if (old)
 722                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 723                                           rcu_head);
 724                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 725                         const struct cfg80211_bss_ies *old;
 726                         struct cfg80211_internal_bss *bss;
 727
 728                         if (found->pub.hidden_beacon_bss &&
 729                             !list_empty(&found->hidden_list)) {
 730                                 const struct cfg80211_bss_ies *f;
 731
 732                                 /*
 733                                  * The found BSS struct is one of the probe
 734                                  * response members of a group, but we're
 735                                  * receiving a beacon (beacon_ies in the tmp
 736                                  * bss is used). This can only mean that the
 737                                  * AP changed its beacon from not having an
 738                                  * SSID to showing it, which is confusing so
 739                                  * drop this information.
 740                                  */
 741
 742                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 743                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 744                                           rcu_head);
 745                                 goto drop;
 746                         }
 747
 748                         old = rcu_access_pointer(found->pub.beacon_ies);
 749
 750                         rcu_assign_pointer(found->pub.beacon_ies,
 751                                            tmp->pub.beacon_ies);
 752
 753                         /* Override IEs if they were from a beacon before */
 754                         if (old == rcu_access_pointer(found->pub.ies))
 755                                 rcu_assign_pointer(found->pub.ies,
 756                                                    tmp->pub.beacon_ies);
 757
 758                         /* Assign beacon IEs to all sub entries */
 759                         list_for_each_entry(bss, &found->hidden_list,
 760                                             hidden_list) {
 761                                 const struct cfg80211_bss_ies *ies;
 762
 763                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 764                                 WARN_ON(ies != old);
 765
 766                                 rcu_assign_pointer(bss->pub.beacon_ies,
 767                                                    tmp->pub.beacon_ies);
 768                         }
 769
 770                         if (old)
 771                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 772                                           rcu_head);
 773                 }
 774
 775                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 776                 /*
 777                  * don't update the signal if beacon was heard on
 778                  * adjacent channel.
 779                  */
 780                 if (signal_valid)
 781                         found->pub.signal = tmp->pub.signal;
 782                 found->pub.capability = tmp->pub.capability;
 783                 found->ts = tmp->ts;
 784         } else {
 785                 struct cfg80211_internal_bss *new;
 786                 struct cfg80211_internal_bss *hidden;
 787                 struct cfg80211_bss_ies *ies;
 788
 789                 /*
 790                  * create a copy -- the "res" variable that is passed in
 791                  * is allocated on the stack since it's not needed in the
 792                  * more common case of an update
 793                  */
 794                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 795                               GFP_ATOMIC);
 796                 if (!new) {
 797                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 798                         if (ies)
 799                                 kfree_rcu(ies, rcu_head);
 800                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 801                         if (ies)
 802                                 kfree_rcu(ies, rcu_head);
 803                         goto drop;
 804                 }
 805                 memcpy(new, tmp, sizeof(*new));
 806                 new->refcount = 1;
 807                 INIT_LIST_HEAD(&new->hidden_list);
 808
 809                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 810                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 811                         if (!hidden)
 812                                 hidden = rb_find_bss(rdev, tmp,
 813                                                      BSS_CMP_HIDE_NUL);
 814                         if (hidden) {
 815                                 new->pub.hidden_beacon_bss = &hidden->pub;
 816                                 list_add(&new->hidden_list,
 817                                          &hidden->hidden_list);
 818                                 hidden->refcount++;
 819                                 rcu_assign_pointer(new->pub.beacon_ies,
 820                                                    hidden->pub.beacon_ies);
 821                         }
 822                 } else {
 823                         /*
 824                          * Ok so we found a beacon, and don't have an entry. If
 825                          * it's a beacon with hidden SSID, we might be in for an
 826                          * expensive search for any probe responses that should
 827                          * be grouped with this beacon for updates ...
 828                          */
 829                         if (!cfg80211_combine_bsses(rdev, new)) {
 830                                 kfree(new);
 831                                 goto drop;
 832                         }
 833                 }
 834
 835                 list_add_tail(&new->list, &rdev->bss_list);
 836                 rb_insert_bss(rdev, new);
 837                 found = new;
 838         }
 839
 840         rdev->bss_generation++;
 841         bss_ref_get(rdev, found);
 842         spin_unlock_bh(&rdev->bss_lock);
 843
 844         return found;
 845  drop:
 846         spin_unlock_bh(&rdev->bss_lock);
 847         return NULL;
 848 }
 849
 850 static struct ieee80211_channel *
 851 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 852                          struct ieee80211_channel *channel)
 853 {
 854         const u8 *tmp;
 855         u32 freq;
 856         int channel_number = -1;
 857
 858         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 859         if (tmp && tmp[1] == 1) {
 860                 channel_number = tmp[2];
 861         } else {
 862                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 863                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 864                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 865
 866                         channel_number = htop->primary_chan;
 867                 }
 868         }
 869
 870         if (channel_number < 0)
 871                 return channel;
 872
 873         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 874         channel = ieee80211_get_channel(wiphy, freq);
 875         if (!channel)
 876                 return NULL;
 877         if (channel->flags & IEEE80211_CHAN_DISABLED)
 878                 return NULL;
 879         return channel;
 880 }
 881
 882 /* Returned bss is reference counted and must be cleaned up appropriately. */
 883 struct cfg80211_bss*
 884 cfg80211_inform_bss_width(struct wiphy *wiphy,
 885                           struct ieee80211_channel *rx_channel,
 886                           enum nl80211_bss_scan_width scan_width,
 887                           const u8 *bssid, u64 tsf, u16 capability,
 888                           u16 beacon_interval, const u8 *ie, size_t ielen,
 889                           s32 signal, gfp_t gfp)
 890 {
 891         struct cfg80211_bss_ies *ies;
 892         struct ieee80211_channel *channel;
 893         struct cfg80211_internal_bss tmp = {}, *res;
 894         bool signal_valid;
 895
 896         if (WARN_ON(!wiphy))
 897                 return NULL;
 898
 899         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 900                         (signal < 0 || signal > 100)))
 901                 return NULL;
 902
 903         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 904         if (!channel)
 905                 return NULL;
 906
 907         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 908         tmp.pub.channel = channel;
 909         tmp.pub.scan_width = scan_width;
 910         tmp.pub.signal = signal;
 911         tmp.pub.beacon_interval = beacon_interval;
 912         tmp.pub.capability = capability;
 913         /*
 914          * Since we do not know here whether the IEs are from a Beacon or Probe
 915          * Response frame, we need to pick one of the options and only use it
 916          * with the driver that does not provide the full Beacon/Probe Response
 917          * frame. Use Beacon frame pointer to avoid indicating that this should
 918          * override the IEs pointer should we have received an earlier
 919          * indication of Probe Response data.
 920          */
 921         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 922         if (!ies)
 923                 return NULL;
 924         ies->len = ielen;
 925         ies->tsf = tsf;
 926         memcpy(ies->data, ie, ielen);
 927
 928         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 929         rcu_assign_pointer(tmp.pub.ies, ies);
 930
 931         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
 932                 wiphy->max_adj_channel_rssi_comp;
 933         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
 934         if (!res)
 935                 return NULL;
 936
 937         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 938                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 939
 940         trace_cfg80211_return_bss(&res->pub);
 941         /* cfg80211_bss_update gives us a referenced result */
 942         return &res->pub;
 943 }
 944 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 945
 946 /* Returned bss is reference counted and must be cleaned up appropriately. */
 947 struct cfg80211_bss *
 948 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 949                                 struct ieee80211_channel *rx_channel,
 950                                 enum nl80211_bss_scan_width scan_width,
 951                                 struct ieee80211_mgmt *mgmt, size_t len,
 952                                 s32 signal, gfp_t gfp)
 953 {
 954         struct cfg80211_internal_bss tmp = {}, *res;
 955         struct cfg80211_bss_ies *ies;
 956         struct ieee80211_channel *channel;
 957         bool signal_valid;
 958         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 959                                       u.probe_resp.variable);
 960
 961         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 962                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 963
 964         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
 965                                               len, signal);
 966
 967         if (WARN_ON(!mgmt))
 968                 return NULL;
 969
 970         if (WARN_ON(!wiphy))
 971                 return NULL;
 972
 973         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 974                     (signal < 0 || signal > 100)))
 975                 return NULL;
 976
 977         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 978                 return NULL;
 979
 980         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 981                                            ielen, rx_channel);
 982         if (!channel)
 983                 return NULL;
 984
 985         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 986         if (!ies)
 987                 return NULL;
 988         ies->len = ielen;
 989         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 990         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 991
 992         if (ieee80211_is_probe_resp(mgmt->frame_control))
 993                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 994         else
 995                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 996         rcu_assign_pointer(tmp.pub.ies, ies);
 997
 998         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 999         tmp.pub.channel = channel;
1000         tmp.pub.scan_width = scan_width;
1001         tmp.pub.signal = signal;
1002         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1003         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1004
1005         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
1006                 wiphy->max_adj_channel_rssi_comp;
1007         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1008         if (!res)
1009                 return NULL;
1010
1011         if (res->pub.capability & WLAN_CAPABILITY_ESS)
1012                 regulatory_hint_found_beacon(wiphy, channel, gfp);
1013
1014         trace_cfg80211_return_bss(&res->pub);
1015         /* cfg80211_bss_update gives us a referenced result */
1016         return &res->pub;
1017 }
1018 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1019
1020 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1021 {
1022         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1023         struct cfg80211_internal_bss *bss;
1024
1025         if (!pub)
1026                 return;
1027
1028         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1029
1030         spin_lock_bh(&rdev->bss_lock);
1031         bss_ref_get(rdev, bss);
1032         spin_unlock_bh(&rdev->bss_lock);
1033 }
1034 EXPORT_SYMBOL(cfg80211_ref_bss);
1035
1036 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1037 {
1038         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1039         struct cfg80211_internal_bss *bss;
1040
1041         if (!pub)
1042                 return;
1043
1044         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1045
1046         spin_lock_bh(&rdev->bss_lock);
1047         bss_ref_put(rdev, bss);
1048         spin_unlock_bh(&rdev->bss_lock);
1049 }
1050 EXPORT_SYMBOL(cfg80211_put_bss);
1051
1052 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1053 {
1054         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1055         struct cfg80211_internal_bss *bss;
1056
1057         if (WARN_ON(!pub))
1058                 return;
1059
1060         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1061
1062         spin_lock_bh(&rdev->bss_lock);
1063         if (!list_empty(&bss->list)) {
1064                 if (__cfg80211_unlink_bss(rdev, bss))
1065                         rdev->bss_generation++;
1066         }
1067         spin_unlock_bh(&rdev->bss_lock);
1068 }
1069 EXPORT_SYMBOL(cfg80211_unlink_bss);
1070
1071 #ifdef CONFIG_CFG80211_WEXT
1072 static struct cfg80211_registered_device *
1073 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1074 {
1075         struct cfg80211_registered_device *rdev;
1076         struct net_device *dev;
1077
1078         ASSERT_RTNL();
1079
1080         dev = dev_get_by_index(net, ifindex);
1081         if (!dev)
1082                 return ERR_PTR(-ENODEV);
1083         if (dev->ieee80211_ptr)
1084                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1085         else
1086                 rdev = ERR_PTR(-ENODEV);
1087         dev_put(dev);
1088         return rdev;
1089 }
1090
1091 int cfg80211_wext_siwscan(struct net_device *dev,
1092                           struct iw_request_info *info,
1093                           union iwreq_data *wrqu, char *extra)
1094 {
1095         struct cfg80211_registered_device *rdev;
1096         struct wiphy *wiphy;
1097         struct iw_scan_req *wreq = NULL;
1098         struct cfg80211_scan_request *creq = NULL;
1099         int i, err, n_channels = 0;
1100         enum ieee80211_band band;
1101
1102         if (!netif_running(dev))
1103                 return -ENETDOWN;
1104
1105         if (wrqu->data.length == sizeof(struct iw_scan_req))
1106                 wreq = (struct iw_scan_req *)extra;
1107
1108         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1109
1110         if (IS_ERR(rdev))
1111                 return PTR_ERR(rdev);
1112
1113         if (rdev->scan_req || rdev->scan_msg) {
1114                 err = -EBUSY;
1115                 goto out;
1116         }
1117
1118         wiphy = &rdev->wiphy;
1119
1120         /* Determine number of channels, needed to allocate creq */
1121         if (wreq && wreq->num_channels)
1122                 n_channels = wreq->num_channels;
1123         else
1124                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1125
1126         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1127                        n_channels * sizeof(void *),
1128                        GFP_ATOMIC);
1129         if (!creq) {
1130                 err = -ENOMEM;
1131                 goto out;
1132         }
1133
1134         creq->wiphy = wiphy;
1135         creq->wdev = dev->ieee80211_ptr;
1136         /* SSIDs come after channels */
1137         creq->ssids = (void *)&creq->channels[n_channels];
1138         creq->n_channels = n_channels;
1139         creq->n_ssids = 1;
1140         creq->scan_start = jiffies;
1141
1142         /* translate "Scan on frequencies" request */
1143         i = 0;
1144         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1145                 int j;
1146
1147                 if (!wiphy->bands[band])
1148                         continue;
1149
1150                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1151                         /* ignore disabled channels */
1152                         if (wiphy->bands[band]->channels[j].flags &
1153                                                 IEEE80211_CHAN_DISABLED)
1154                                 continue;
1155
1156                         /* If we have a wireless request structure and the
1157                          * wireless request specifies frequencies, then search
1158                          * for the matching hardware channel.
1159                          */
1160                         if (wreq && wreq->num_channels) {
1161                                 int k;
1162                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1163                                 for (k = 0; k < wreq->num_channels; k++) {
1164                                         struct iw_freq *freq =
1165                                                 &wreq->channel_list[k];
1166                                         int wext_freq =
1167                                                 cfg80211_wext_freq(freq);
1168
1169                                         if (wext_freq == wiphy_freq)
1170                                                 goto wext_freq_found;
1171                                 }
1172                                 goto wext_freq_not_found;
1173                         }
1174
1175                 wext_freq_found:
1176                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1177                         i++;
1178                 wext_freq_not_found: ;
1179                 }
1180         }
1181         /* No channels found? */
1182         if (!i) {
1183                 err = -EINVAL;
1184                 goto out;
1185         }
1186
1187         /* Set real number of channels specified in creq->channels[] */
1188         creq->n_channels = i;
1189
1190         /* translate "Scan for SSID" request */
1191         if (wreq) {
1192                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1193                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1194                                 err = -EINVAL;
1195                                 goto out;
1196                         }
1197                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1198                         creq->ssids[0].ssid_len = wreq->essid_len;
1199                 }
1200                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1201                         creq->n_ssids = 0;
1202         }
1203
1204         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1205                 if (wiphy->bands[i])
1206                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1207
1208         rdev->scan_req = creq;
1209         err = rdev_scan(rdev, creq);
1210         if (err) {
1211                 rdev->scan_req = NULL;
1212                 /* creq will be freed below */
1213         } else {
1214                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1215                 /* creq now owned by driver */
1216                 creq = NULL;
1217                 dev_hold(dev);
1218         }
1219  out:
1220         kfree(creq);
1221         return err;
1222 }
1223 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1224
1225 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1226                                    const struct cfg80211_bss_ies *ies,
1227                                    char **current_ev, char *end_buf)
1228 {
1229         const u8 *pos, *end, *next;
1230         struct iw_event iwe;
1231
1232         if (!ies)
1233                 return;
1234
1235         /*
1236          * If needed, fragment the IEs buffer (at IE boundaries) into short
1237          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1238          */
1239         pos = ies->data;
1240         end = pos + ies->len;
1241
1242         while (end - pos > IW_GENERIC_IE_MAX) {
1243                 next = pos + 2 + pos[1];
1244                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1245                         next = next + 2 + next[1];
1246
1247                 memset(&iwe, 0, sizeof(iwe));
1248                 iwe.cmd = IWEVGENIE;
1249                 iwe.u.data.length = next - pos;
1250                 *current_ev = iwe_stream_add_point(info, *current_ev,
1251                                                    end_buf, &iwe,
1252                                                    (void *)pos);
1253
1254                 pos = next;
1255         }
1256
1257         if (end > pos) {
1258                 memset(&iwe, 0, sizeof(iwe));
1259                 iwe.cmd = IWEVGENIE;
1260                 iwe.u.data.length = end - pos;
1261                 *current_ev = iwe_stream_add_point(info, *current_ev,
1262                                                    end_buf, &iwe,
1263                                                    (void *)pos);
1264         }
1265 }
1266
1267 static char *
1268 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1269               struct cfg80211_internal_bss *bss, char *current_ev,
1270               char *end_buf)
1271 {
1272         const struct cfg80211_bss_ies *ies;
1273         struct iw_event iwe;
1274         const u8 *ie;
1275         u8 *buf, *cfg, *p;
1276         int rem, i, sig;
1277         bool ismesh = false;
1278
1279         memset(&iwe, 0, sizeof(iwe));
1280         iwe.cmd = SIOCGIWAP;
1281         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1282         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1283         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1284                                           IW_EV_ADDR_LEN);
1285
1286         memset(&iwe, 0, sizeof(iwe));
1287         iwe.cmd = SIOCGIWFREQ;
1288         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1289         iwe.u.freq.e = 0;
1290         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1291                                           IW_EV_FREQ_LEN);
1292
1293         memset(&iwe, 0, sizeof(iwe));
1294         iwe.cmd = SIOCGIWFREQ;
1295         iwe.u.freq.m = bss->pub.channel->center_freq;
1296         iwe.u.freq.e = 6;
1297         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1298                                           IW_EV_FREQ_LEN);
1299
1300         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1301                 memset(&iwe, 0, sizeof(iwe));
1302                 iwe.cmd = IWEVQUAL;
1303                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1304                                      IW_QUAL_NOISE_INVALID |
1305                                      IW_QUAL_QUAL_UPDATED;
1306                 switch (wiphy->signal_type) {
1307                 case CFG80211_SIGNAL_TYPE_MBM:
1308                         sig = bss->pub.signal / 100;
1309                         iwe.u.qual.level = sig;
1310                         iwe.u.qual.updated |= IW_QUAL_DBM;
1311                         if (sig < -110)         /* rather bad */
1312                                 sig = -110;
1313                         else if (sig > -40)     /* perfect */
1314                                 sig = -40;
1315                         /* will give a range of 0 .. 70 */
1316                         iwe.u.qual.qual = sig + 110;
1317                         break;
1318                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1319                         iwe.u.qual.level = bss->pub.signal;
1320                         /* will give range 0 .. 100 */
1321                         iwe.u.qual.qual = bss->pub.signal;
1322                         break;
1323                 default:
1324                         /* not reached */
1325                         break;
1326                 }
1327                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1328                                                   &iwe, IW_EV_QUAL_LEN);
1329         }
1330
1331         memset(&iwe, 0, sizeof(iwe));
1332         iwe.cmd = SIOCGIWENCODE;
1333         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1334                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1335         else
1336                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1337         iwe.u.data.length = 0;
1338         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1339                                           &iwe, "");
1340
1341         rcu_read_lock();
1342         ies = rcu_dereference(bss->pub.ies);
1343         rem = ies->len;
1344         ie = ies->data;
1345
1346         while (rem >= 2) {
1347                 /* invalid data */
1348                 if (ie[1] > rem - 2)
1349                         break;
1350
1351                 switch (ie[0]) {
1352                 case WLAN_EID_SSID:
1353                         memset(&iwe, 0, sizeof(iwe));
1354                         iwe.cmd = SIOCGIWESSID;
1355                         iwe.u.data.length = ie[1];
1356                         iwe.u.data.flags = 1;
1357                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1358                                                           &iwe, (u8 *)ie + 2);
1359                         break;
1360                 case WLAN_EID_MESH_ID:
1361                         memset(&iwe, 0, sizeof(iwe));
1362                         iwe.cmd = SIOCGIWESSID;
1363                         iwe.u.data.length = ie[1];
1364                         iwe.u.data.flags = 1;
1365                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1366                                                           &iwe, (u8 *)ie + 2);
1367                         break;
1368                 case WLAN_EID_MESH_CONFIG:
1369                         ismesh = true;
1370                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1371                                 break;
1372                         buf = kmalloc(50, GFP_ATOMIC);
1373                         if (!buf)
1374                                 break;
1375                         cfg = (u8 *)ie + 2;
1376                         memset(&iwe, 0, sizeof(iwe));
1377                         iwe.cmd = IWEVCUSTOM;
1378                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1379                                 "0x%02X", cfg[0]);
1380                         iwe.u.data.length = strlen(buf);
1381                         current_ev = iwe_stream_add_point(info, current_ev,
1382                                                           end_buf,
1383                                                           &iwe, buf);
1384                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1385                                 cfg[1]);
1386                         iwe.u.data.length = strlen(buf);
1387                         current_ev = iwe_stream_add_point(info, current_ev,
1388                                                           end_buf,
1389                                                           &iwe, buf);
1390                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1391                                 cfg[2]);
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, "Synchronization ID: 0x%02X", cfg[3]);
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, "Authentication ID: 0x%02X", cfg[4]);
1402                         iwe.u.data.length = strlen(buf);
1403                         current_ev = iwe_stream_add_point(info, current_ev,
1404                                                           end_buf,
1405                                                           &iwe, buf);
1406                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1407                         iwe.u.data.length = strlen(buf);
1408                         current_ev = iwe_stream_add_point(info, current_ev,
1409                                                           end_buf,
1410                                                           &iwe, buf);
1411                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1412                         iwe.u.data.length = strlen(buf);
1413                         current_ev = iwe_stream_add_point(info, current_ev,
1414                                                           end_buf,
1415                                                           &iwe, buf);
1416                         kfree(buf);
1417                         break;
1418                 case WLAN_EID_SUPP_RATES:
1419                 case WLAN_EID_EXT_SUPP_RATES:
1420                         /* display all supported rates in readable format */
1421                         p = current_ev + iwe_stream_lcp_len(info);
1422
1423                         memset(&iwe, 0, sizeof(iwe));
1424                         iwe.cmd = SIOCGIWRATE;
1425                         /* Those two flags are ignored... */
1426                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1427
1428                         for (i = 0; i < ie[1]; i++) {
1429                                 iwe.u.bitrate.value =
1430                                         ((ie[i + 2] & 0x7f) * 500000);
1431                                 p = iwe_stream_add_value(info, current_ev, p,
1432                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1433                         }
1434                         current_ev = p;
1435                         break;
1436                 }
1437                 rem -= ie[1] + 2;
1438                 ie += ie[1] + 2;
1439         }
1440
1441         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1442             ismesh) {
1443                 memset(&iwe, 0, sizeof(iwe));
1444                 iwe.cmd = SIOCGIWMODE;
1445                 if (ismesh)
1446                         iwe.u.mode = IW_MODE_MESH;
1447                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1448                         iwe.u.mode = IW_MODE_MASTER;
1449                 else
1450                         iwe.u.mode = IW_MODE_ADHOC;
1451                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1452                                                   &iwe, IW_EV_UINT_LEN);
1453         }
1454
1455         buf = kmalloc(31, GFP_ATOMIC);
1456         if (buf) {
1457                 memset(&iwe, 0, sizeof(iwe));
1458                 iwe.cmd = IWEVCUSTOM;
1459                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1460                 iwe.u.data.length = strlen(buf);
1461                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1462                                                   &iwe, buf);
1463                 memset(&iwe, 0, sizeof(iwe));
1464                 iwe.cmd = IWEVCUSTOM;
1465                 sprintf(buf, " Last beacon: %ums ago",
1466                         elapsed_jiffies_msecs(bss->ts));
1467                 iwe.u.data.length = strlen(buf);
1468                 current_ev = iwe_stream_add_point(info, current_ev,
1469                                                   end_buf, &iwe, buf);
1470                 kfree(buf);
1471         }
1472
1473         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1474         rcu_read_unlock();
1475
1476         return current_ev;
1477 }
1478
1479
1480 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1481                                   struct iw_request_info *info,
1482                                   char *buf, size_t len)
1483 {
1484         char *current_ev = buf;
1485         char *end_buf = buf + len;
1486         struct cfg80211_internal_bss *bss;
1487
1488         spin_lock_bh(&rdev->bss_lock);
1489         cfg80211_bss_expire(rdev);
1490
1491         list_for_each_entry(bss, &rdev->bss_list, list) {
1492                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1493                         spin_unlock_bh(&rdev->bss_lock);
1494                         return -E2BIG;
1495                 }
1496                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1497                                            current_ev, end_buf);
1498         }
1499         spin_unlock_bh(&rdev->bss_lock);
1500         return current_ev - buf;
1501 }
1502
1503
1504 int cfg80211_wext_giwscan(struct net_device *dev,
1505                           struct iw_request_info *info,
1506                           struct iw_point *data, char *extra)
1507 {
1508         struct cfg80211_registered_device *rdev;
1509         int res;
1510
1511         if (!netif_running(dev))
1512                 return -ENETDOWN;
1513
1514         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1515
1516         if (IS_ERR(rdev))
1517                 return PTR_ERR(rdev);
1518
1519         if (rdev->scan_req || rdev->scan_msg)
1520                 return -EAGAIN;
1521
1522         res = ieee80211_scan_results(rdev, info, extra, data->length);
1523         data->length = 0;
1524         if (res >= 0) {
1525                 data->length = res;
1526                 res = 0;
1527         }
1528
1529         return res;
1530 }
1531 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1532 #endif