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                           enum cfg80211_bss_frame_type ftype,
 888                           const u8 *bssid, u64 tsf, u16 capability,
 889                           u16 beacon_interval, const u8 *ie, size_t ielen,
 890                           s32 signal, gfp_t gfp)
 891 {
 892         struct cfg80211_bss_ies *ies;
 893         struct ieee80211_channel *channel;
 894         struct cfg80211_internal_bss tmp = {}, *res;
 895         bool signal_valid;
 896
 897         if (WARN_ON(!wiphy))
 898                 return NULL;
 899
 900         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 901                         (signal < 0 || signal > 100)))
 902                 return NULL;
 903
 904         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 905         if (!channel)
 906                 return NULL;
 907
 908         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 909         tmp.pub.channel = channel;
 910         tmp.pub.scan_width = scan_width;
 911         tmp.pub.signal = signal;
 912         tmp.pub.beacon_interval = beacon_interval;
 913         tmp.pub.capability = capability;
 914         /*
 915          * If we do not know here whether the IEs are from a Beacon or Probe
 916          * Response frame, we need to pick one of the options and only use it
 917          * with the driver that does not provide the full Beacon/Probe Response
 918          * frame. Use Beacon frame pointer to avoid indicating that this should
 919          * override the IEs pointer should we have received an earlier
 920          * indication of Probe Response data.
 921          */
 922         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 923         if (!ies)
 924                 return NULL;
 925         ies->len = ielen;
 926         ies->tsf = tsf;
 927         ies->from_beacon = false;
 928         memcpy(ies->data, ie, ielen);
 929
 930         switch (ftype) {
 931         case CFG80211_BSS_FTYPE_BEACON:
 932                 ies->from_beacon = true;
 933                 /* fall through to assign */
 934         case CFG80211_BSS_FTYPE_UNKNOWN:
 935                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 936                 break;
 937         case CFG80211_BSS_FTYPE_PRESP:
 938                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 939                 break;
 940         }
 941         rcu_assign_pointer(tmp.pub.ies, ies);
 942
 943         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
 944                 wiphy->max_adj_channel_rssi_comp;
 945         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
 946         if (!res)
 947                 return NULL;
 948
 949         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 950                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 951
 952         trace_cfg80211_return_bss(&res->pub);
 953         /* cfg80211_bss_update gives us a referenced result */
 954         return &res->pub;
 955 }
 956 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 957
 958 /* Returned bss is reference counted and must be cleaned up appropriately. */
 959 struct cfg80211_bss *
 960 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 961                                 struct ieee80211_channel *rx_channel,
 962                                 enum nl80211_bss_scan_width scan_width,
 963                                 struct ieee80211_mgmt *mgmt, size_t len,
 964                                 s32 signal, gfp_t gfp)
 965 {
 966         struct cfg80211_internal_bss tmp = {}, *res;
 967         struct cfg80211_bss_ies *ies;
 968         struct ieee80211_channel *channel;
 969         bool signal_valid;
 970         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 971                                       u.probe_resp.variable);
 972
 973         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 974                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 975
 976         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
 977                                               len, signal);
 978
 979         if (WARN_ON(!mgmt))
 980                 return NULL;
 981
 982         if (WARN_ON(!wiphy))
 983                 return NULL;
 984
 985         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 986                     (signal < 0 || signal > 100)))
 987                 return NULL;
 988
 989         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 990                 return NULL;
 991
 992         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 993                                            ielen, rx_channel);
 994         if (!channel)
 995                 return NULL;
 996
 997         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 998         if (!ies)
 999                 return NULL;
1000         ies->len = ielen;
1001         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1002         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1003         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1004
1005         if (ieee80211_is_probe_resp(mgmt->frame_control))
1006                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1007         else
1008                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1009         rcu_assign_pointer(tmp.pub.ies, ies);
1010
1011         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1012         tmp.pub.channel = channel;
1013         tmp.pub.scan_width = scan_width;
1014         tmp.pub.signal = signal;
1015         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1016         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1017
1018         signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
1019                 wiphy->max_adj_channel_rssi_comp;
1020         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1021         if (!res)
1022                 return NULL;
1023
1024         if (res->pub.capability & WLAN_CAPABILITY_ESS)
1025                 regulatory_hint_found_beacon(wiphy, channel, gfp);
1026
1027         trace_cfg80211_return_bss(&res->pub);
1028         /* cfg80211_bss_update gives us a referenced result */
1029         return &res->pub;
1030 }
1031 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1032
1033 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1034 {
1035         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1036         struct cfg80211_internal_bss *bss;
1037
1038         if (!pub)
1039                 return;
1040
1041         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1042
1043         spin_lock_bh(&rdev->bss_lock);
1044         bss_ref_get(rdev, bss);
1045         spin_unlock_bh(&rdev->bss_lock);
1046 }
1047 EXPORT_SYMBOL(cfg80211_ref_bss);
1048
1049 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1050 {
1051         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1052         struct cfg80211_internal_bss *bss;
1053
1054         if (!pub)
1055                 return;
1056
1057         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1058
1059         spin_lock_bh(&rdev->bss_lock);
1060         bss_ref_put(rdev, bss);
1061         spin_unlock_bh(&rdev->bss_lock);
1062 }
1063 EXPORT_SYMBOL(cfg80211_put_bss);
1064
1065 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1066 {
1067         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1068         struct cfg80211_internal_bss *bss;
1069
1070         if (WARN_ON(!pub))
1071                 return;
1072
1073         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1074
1075         spin_lock_bh(&rdev->bss_lock);
1076         if (!list_empty(&bss->list)) {
1077                 if (__cfg80211_unlink_bss(rdev, bss))
1078                         rdev->bss_generation++;
1079         }
1080         spin_unlock_bh(&rdev->bss_lock);
1081 }
1082 EXPORT_SYMBOL(cfg80211_unlink_bss);
1083
1084 #ifdef CONFIG_CFG80211_WEXT
1085 static struct cfg80211_registered_device *
1086 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1087 {
1088         struct cfg80211_registered_device *rdev;
1089         struct net_device *dev;
1090
1091         ASSERT_RTNL();
1092
1093         dev = dev_get_by_index(net, ifindex);
1094         if (!dev)
1095                 return ERR_PTR(-ENODEV);
1096         if (dev->ieee80211_ptr)
1097                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1098         else
1099                 rdev = ERR_PTR(-ENODEV);
1100         dev_put(dev);
1101         return rdev;
1102 }
1103
1104 int cfg80211_wext_siwscan(struct net_device *dev,
1105                           struct iw_request_info *info,
1106                           union iwreq_data *wrqu, char *extra)
1107 {
1108         struct cfg80211_registered_device *rdev;
1109         struct wiphy *wiphy;
1110         struct iw_scan_req *wreq = NULL;
1111         struct cfg80211_scan_request *creq = NULL;
1112         int i, err, n_channels = 0;
1113         enum ieee80211_band band;
1114
1115         if (!netif_running(dev))
1116                 return -ENETDOWN;
1117
1118         if (wrqu->data.length == sizeof(struct iw_scan_req))
1119                 wreq = (struct iw_scan_req *)extra;
1120
1121         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1122
1123         if (IS_ERR(rdev))
1124                 return PTR_ERR(rdev);
1125
1126         if (rdev->scan_req || rdev->scan_msg) {
1127                 err = -EBUSY;
1128                 goto out;
1129         }
1130
1131         wiphy = &rdev->wiphy;
1132
1133         /* Determine number of channels, needed to allocate creq */
1134         if (wreq && wreq->num_channels)
1135                 n_channels = wreq->num_channels;
1136         else
1137                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1138
1139         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1140                        n_channels * sizeof(void *),
1141                        GFP_ATOMIC);
1142         if (!creq) {
1143                 err = -ENOMEM;
1144                 goto out;
1145         }
1146
1147         creq->wiphy = wiphy;
1148         creq->wdev = dev->ieee80211_ptr;
1149         /* SSIDs come after channels */
1150         creq->ssids = (void *)&creq->channels[n_channels];
1151         creq->n_channels = n_channels;
1152         creq->n_ssids = 1;
1153         creq->scan_start = jiffies;
1154
1155         /* translate "Scan on frequencies" request */
1156         i = 0;
1157         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1158                 int j;
1159
1160                 if (!wiphy->bands[band])
1161                         continue;
1162
1163                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1164                         /* ignore disabled channels */
1165                         if (wiphy->bands[band]->channels[j].flags &
1166                                                 IEEE80211_CHAN_DISABLED)
1167                                 continue;
1168
1169                         /* If we have a wireless request structure and the
1170                          * wireless request specifies frequencies, then search
1171                          * for the matching hardware channel.
1172                          */
1173                         if (wreq && wreq->num_channels) {
1174                                 int k;
1175                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1176                                 for (k = 0; k < wreq->num_channels; k++) {
1177                                         struct iw_freq *freq =
1178                                                 &wreq->channel_list[k];
1179                                         int wext_freq =
1180                                                 cfg80211_wext_freq(freq);
1181
1182                                         if (wext_freq == wiphy_freq)
1183                                                 goto wext_freq_found;
1184                                 }
1185                                 goto wext_freq_not_found;
1186                         }
1187
1188                 wext_freq_found:
1189                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1190                         i++;
1191                 wext_freq_not_found: ;
1192                 }
1193         }
1194         /* No channels found? */
1195         if (!i) {
1196                 err = -EINVAL;
1197                 goto out;
1198         }
1199
1200         /* Set real number of channels specified in creq->channels[] */
1201         creq->n_channels = i;
1202
1203         /* translate "Scan for SSID" request */
1204         if (wreq) {
1205                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1206                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1207                                 err = -EINVAL;
1208                                 goto out;
1209                         }
1210                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1211                         creq->ssids[0].ssid_len = wreq->essid_len;
1212                 }
1213                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1214                         creq->n_ssids = 0;
1215         }
1216
1217         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1218                 if (wiphy->bands[i])
1219                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1220
1221         rdev->scan_req = creq;
1222         err = rdev_scan(rdev, creq);
1223         if (err) {
1224                 rdev->scan_req = NULL;
1225                 /* creq will be freed below */
1226         } else {
1227                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1228                 /* creq now owned by driver */
1229                 creq = NULL;
1230                 dev_hold(dev);
1231         }
1232  out:
1233         kfree(creq);
1234         return err;
1235 }
1236 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1237
1238 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1239                                    const struct cfg80211_bss_ies *ies,
1240                                    char **current_ev, char *end_buf)
1241 {
1242         const u8 *pos, *end, *next;
1243         struct iw_event iwe;
1244
1245         if (!ies)
1246                 return;
1247
1248         /*
1249          * If needed, fragment the IEs buffer (at IE boundaries) into short
1250          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1251          */
1252         pos = ies->data;
1253         end = pos + ies->len;
1254
1255         while (end - pos > IW_GENERIC_IE_MAX) {
1256                 next = pos + 2 + pos[1];
1257                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1258                         next = next + 2 + next[1];
1259
1260                 memset(&iwe, 0, sizeof(iwe));
1261                 iwe.cmd = IWEVGENIE;
1262                 iwe.u.data.length = next - pos;
1263                 *current_ev = iwe_stream_add_point(info, *current_ev,
1264                                                    end_buf, &iwe,
1265                                                    (void *)pos);
1266
1267                 pos = next;
1268         }
1269
1270         if (end > pos) {
1271                 memset(&iwe, 0, sizeof(iwe));
1272                 iwe.cmd = IWEVGENIE;
1273                 iwe.u.data.length = end - pos;
1274                 *current_ev = iwe_stream_add_point(info, *current_ev,
1275                                                    end_buf, &iwe,
1276                                                    (void *)pos);
1277         }
1278 }
1279
1280 static char *
1281 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1282               struct cfg80211_internal_bss *bss, char *current_ev,
1283               char *end_buf)
1284 {
1285         const struct cfg80211_bss_ies *ies;
1286         struct iw_event iwe;
1287         const u8 *ie;
1288         u8 *buf, *cfg, *p;
1289         int rem, i, sig;
1290         bool ismesh = false;
1291
1292         memset(&iwe, 0, sizeof(iwe));
1293         iwe.cmd = SIOCGIWAP;
1294         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1295         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1296         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1297                                           IW_EV_ADDR_LEN);
1298
1299         memset(&iwe, 0, sizeof(iwe));
1300         iwe.cmd = SIOCGIWFREQ;
1301         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1302         iwe.u.freq.e = 0;
1303         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1304                                           IW_EV_FREQ_LEN);
1305
1306         memset(&iwe, 0, sizeof(iwe));
1307         iwe.cmd = SIOCGIWFREQ;
1308         iwe.u.freq.m = bss->pub.channel->center_freq;
1309         iwe.u.freq.e = 6;
1310         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1311                                           IW_EV_FREQ_LEN);
1312
1313         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1314                 memset(&iwe, 0, sizeof(iwe));
1315                 iwe.cmd = IWEVQUAL;
1316                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1317                                      IW_QUAL_NOISE_INVALID |
1318                                      IW_QUAL_QUAL_UPDATED;
1319                 switch (wiphy->signal_type) {
1320                 case CFG80211_SIGNAL_TYPE_MBM:
1321                         sig = bss->pub.signal / 100;
1322                         iwe.u.qual.level = sig;
1323                         iwe.u.qual.updated |= IW_QUAL_DBM;
1324                         if (sig < -110)         /* rather bad */
1325                                 sig = -110;
1326                         else if (sig > -40)     /* perfect */
1327                                 sig = -40;
1328                         /* will give a range of 0 .. 70 */
1329                         iwe.u.qual.qual = sig + 110;
1330                         break;
1331                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1332                         iwe.u.qual.level = bss->pub.signal;
1333                         /* will give range 0 .. 100 */
1334                         iwe.u.qual.qual = bss->pub.signal;
1335                         break;
1336                 default:
1337                         /* not reached */
1338                         break;
1339                 }
1340                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1341                                                   &iwe, IW_EV_QUAL_LEN);
1342         }
1343
1344         memset(&iwe, 0, sizeof(iwe));
1345         iwe.cmd = SIOCGIWENCODE;
1346         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1347                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1348         else
1349                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1350         iwe.u.data.length = 0;
1351         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1352                                           &iwe, "");
1353
1354         rcu_read_lock();
1355         ies = rcu_dereference(bss->pub.ies);
1356         rem = ies->len;
1357         ie = ies->data;
1358
1359         while (rem >= 2) {
1360                 /* invalid data */
1361                 if (ie[1] > rem - 2)
1362                         break;
1363
1364                 switch (ie[0]) {
1365                 case WLAN_EID_SSID:
1366                         memset(&iwe, 0, sizeof(iwe));
1367                         iwe.cmd = SIOCGIWESSID;
1368                         iwe.u.data.length = ie[1];
1369                         iwe.u.data.flags = 1;
1370                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1371                                                           &iwe, (u8 *)ie + 2);
1372                         break;
1373                 case WLAN_EID_MESH_ID:
1374                         memset(&iwe, 0, sizeof(iwe));
1375                         iwe.cmd = SIOCGIWESSID;
1376                         iwe.u.data.length = ie[1];
1377                         iwe.u.data.flags = 1;
1378                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1379                                                           &iwe, (u8 *)ie + 2);
1380                         break;
1381                 case WLAN_EID_MESH_CONFIG:
1382                         ismesh = true;
1383                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1384                                 break;
1385                         buf = kmalloc(50, GFP_ATOMIC);
1386                         if (!buf)
1387                                 break;
1388                         cfg = (u8 *)ie + 2;
1389                         memset(&iwe, 0, sizeof(iwe));
1390                         iwe.cmd = IWEVCUSTOM;
1391                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1392                                 "0x%02X", cfg[0]);
1393                         iwe.u.data.length = strlen(buf);
1394                         current_ev = iwe_stream_add_point(info, current_ev,
1395                                                           end_buf,
1396                                                           &iwe, buf);
1397                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1398                                 cfg[1]);
1399                         iwe.u.data.length = strlen(buf);
1400                         current_ev = iwe_stream_add_point(info, current_ev,
1401                                                           end_buf,
1402                                                           &iwe, buf);
1403                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1404                                 cfg[2]);
1405                         iwe.u.data.length = strlen(buf);
1406                         current_ev = iwe_stream_add_point(info, current_ev,
1407                                                           end_buf,
1408                                                           &iwe, buf);
1409                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1410                         iwe.u.data.length = strlen(buf);
1411                         current_ev = iwe_stream_add_point(info, current_ev,
1412                                                           end_buf,
1413                                                           &iwe, buf);
1414                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1415                         iwe.u.data.length = strlen(buf);
1416                         current_ev = iwe_stream_add_point(info, current_ev,
1417                                                           end_buf,
1418                                                           &iwe, buf);
1419                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1420                         iwe.u.data.length = strlen(buf);
1421                         current_ev = iwe_stream_add_point(info, current_ev,
1422                                                           end_buf,
1423                                                           &iwe, buf);
1424                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1425                         iwe.u.data.length = strlen(buf);
1426                         current_ev = iwe_stream_add_point(info, current_ev,
1427                                                           end_buf,
1428                                                           &iwe, buf);
1429                         kfree(buf);
1430                         break;
1431                 case WLAN_EID_SUPP_RATES:
1432                 case WLAN_EID_EXT_SUPP_RATES:
1433                         /* display all supported rates in readable format */
1434                         p = current_ev + iwe_stream_lcp_len(info);
1435
1436                         memset(&iwe, 0, sizeof(iwe));
1437                         iwe.cmd = SIOCGIWRATE;
1438                         /* Those two flags are ignored... */
1439                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1440
1441                         for (i = 0; i < ie[1]; i++) {
1442                                 iwe.u.bitrate.value =
1443                                         ((ie[i + 2] & 0x7f) * 500000);
1444                                 p = iwe_stream_add_value(info, current_ev, p,
1445                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1446                         }
1447                         current_ev = p;
1448                         break;
1449                 }
1450                 rem -= ie[1] + 2;
1451                 ie += ie[1] + 2;
1452         }
1453
1454         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1455             ismesh) {
1456                 memset(&iwe, 0, sizeof(iwe));
1457                 iwe.cmd = SIOCGIWMODE;
1458                 if (ismesh)
1459                         iwe.u.mode = IW_MODE_MESH;
1460                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1461                         iwe.u.mode = IW_MODE_MASTER;
1462                 else
1463                         iwe.u.mode = IW_MODE_ADHOC;
1464                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1465                                                   &iwe, IW_EV_UINT_LEN);
1466         }
1467
1468         buf = kmalloc(31, GFP_ATOMIC);
1469         if (buf) {
1470                 memset(&iwe, 0, sizeof(iwe));
1471                 iwe.cmd = IWEVCUSTOM;
1472                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1473                 iwe.u.data.length = strlen(buf);
1474                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1475                                                   &iwe, buf);
1476                 memset(&iwe, 0, sizeof(iwe));
1477                 iwe.cmd = IWEVCUSTOM;
1478                 sprintf(buf, " Last beacon: %ums ago",
1479                         elapsed_jiffies_msecs(bss->ts));
1480                 iwe.u.data.length = strlen(buf);
1481                 current_ev = iwe_stream_add_point(info, current_ev,
1482                                                   end_buf, &iwe, buf);
1483                 kfree(buf);
1484         }
1485
1486         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1487         rcu_read_unlock();
1488
1489         return current_ev;
1490 }
1491
1492
1493 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1494                                   struct iw_request_info *info,
1495                                   char *buf, size_t len)
1496 {
1497         char *current_ev = buf;
1498         char *end_buf = buf + len;
1499         struct cfg80211_internal_bss *bss;
1500
1501         spin_lock_bh(&rdev->bss_lock);
1502         cfg80211_bss_expire(rdev);
1503
1504         list_for_each_entry(bss, &rdev->bss_list, list) {
1505                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1506                         spin_unlock_bh(&rdev->bss_lock);
1507                         return -E2BIG;
1508                 }
1509                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1510                                            current_ev, end_buf);
1511         }
1512         spin_unlock_bh(&rdev->bss_lock);
1513         return current_ev - buf;
1514 }
1515
1516
1517 int cfg80211_wext_giwscan(struct net_device *dev,
1518                           struct iw_request_info *info,
1519                           struct iw_point *data, char *extra)
1520 {
1521         struct cfg80211_registered_device *rdev;
1522         int res;
1523
1524         if (!netif_running(dev))
1525                 return -ENETDOWN;
1526
1527         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1528
1529         if (IS_ERR(rdev))
1530                 return PTR_ERR(rdev);
1531
1532         if (rdev->scan_req || rdev->scan_msg)
1533                 return -EAGAIN;
1534
1535         res = ieee80211_scan_results(rdev, info, extra, data->length);
1536         data->length = 0;
1537         if (res >= 0) {
1538                 data->length = res;
1539                 res = 0;
1540         }
1541
1542         return res;
1543 }
1544 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1545 #endif