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(struct wiphy *wiphy)
 288 {
 289         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 290
 291         trace_cfg80211_sched_scan_stopped(wiphy);
 292
 293         rtnl_lock();
 294         __cfg80211_stop_sched_scan(rdev, true);
 295         rtnl_unlock();
 296 }
 297 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 298
 299 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 300                                bool driver_initiated)
 301 {
 302         struct net_device *dev;
 303
 304         ASSERT_RTNL();
 305
 306         if (!rdev->sched_scan_req)
 307                 return -ENOENT;
 308
 309         dev = rdev->sched_scan_req->dev;
 310
 311         if (!driver_initiated) {
 312                 int err = rdev_sched_scan_stop(rdev, dev);
 313                 if (err)
 314                         return err;
 315         }
 316
 317         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 318
 319         kfree(rdev->sched_scan_req);
 320         rdev->sched_scan_req = NULL;
 321
 322         return 0;
 323 }
 324
 325 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 326                       unsigned long age_secs)
 327 {
 328         struct cfg80211_internal_bss *bss;
 329         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 330
 331         spin_lock_bh(&rdev->bss_lock);
 332         list_for_each_entry(bss, &rdev->bss_list, list)
 333                 bss->ts -= age_jiffies;
 334         spin_unlock_bh(&rdev->bss_lock);
 335 }
 336
 337 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 338 {
 339         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 340 }
 341
 342 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 343 {
 344         while (len > 2 && ies[0] != eid) {
 345                 len -= ies[1] + 2;
 346                 ies += ies[1] + 2;
 347         }
 348         if (len < 2)
 349                 return NULL;
 350         if (len < 2 + ies[1])
 351                 return NULL;
 352         return ies;
 353 }
 354 EXPORT_SYMBOL(cfg80211_find_ie);
 355
 356 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 357                                   const u8 *ies, int len)
 358 {
 359         struct ieee80211_vendor_ie *ie;
 360         const u8 *pos = ies, *end = ies + len;
 361         int ie_oui;
 362
 363         while (pos < end) {
 364                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 365                                        end - pos);
 366                 if (!pos)
 367                         return NULL;
 368
 369                 ie = (struct ieee80211_vendor_ie *)pos;
 370
 371                 /* make sure we can access ie->len */
 372                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 373
 374                 if (ie->len < sizeof(*ie))
 375                         goto cont;
 376
 377                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 378                 if (ie_oui == oui && ie->oui_type == oui_type)
 379                         return pos;
 380 cont:
 381                 pos += 2 + ie->len;
 382         }
 383         return NULL;
 384 }
 385 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 386
 387 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 388                    const u8 *ssid, size_t ssid_len)
 389 {
 390         const struct cfg80211_bss_ies *ies;
 391         const u8 *ssidie;
 392
 393         if (bssid && !ether_addr_equal(a->bssid, bssid))
 394                 return false;
 395
 396         if (!ssid)
 397                 return true;
 398
 399         ies = rcu_access_pointer(a->ies);
 400         if (!ies)
 401                 return false;
 402         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 403         if (!ssidie)
 404                 return false;
 405         if (ssidie[1] != ssid_len)
 406                 return false;
 407         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 408 }
 409
 410 /**
 411  * enum bss_compare_mode - BSS compare mode
 412  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 413  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 414  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 415  */
 416 enum bss_compare_mode {
 417         BSS_CMP_REGULAR,
 418         BSS_CMP_HIDE_ZLEN,
 419         BSS_CMP_HIDE_NUL,
 420 };
 421
 422 static int cmp_bss(struct cfg80211_bss *a,
 423                    struct cfg80211_bss *b,
 424                    enum bss_compare_mode mode)
 425 {
 426         const struct cfg80211_bss_ies *a_ies, *b_ies;
 427         const u8 *ie1 = NULL;
 428         const u8 *ie2 = NULL;
 429         int i, r;
 430
 431         if (a->channel != b->channel)
 432                 return b->channel->center_freq - a->channel->center_freq;
 433
 434         a_ies = rcu_access_pointer(a->ies);
 435         if (!a_ies)
 436                 return -1;
 437         b_ies = rcu_access_pointer(b->ies);
 438         if (!b_ies)
 439                 return 1;
 440
 441         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 442                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 443                                        a_ies->data, a_ies->len);
 444         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 445                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 446                                        b_ies->data, b_ies->len);
 447         if (ie1 && ie2) {
 448                 int mesh_id_cmp;
 449
 450                 if (ie1[1] == ie2[1])
 451                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 452                 else
 453                         mesh_id_cmp = ie2[1] - ie1[1];
 454
 455                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 456                                        a_ies->data, a_ies->len);
 457                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 458                                        b_ies->data, b_ies->len);
 459                 if (ie1 && ie2) {
 460                         if (mesh_id_cmp)
 461                                 return mesh_id_cmp;
 462                         if (ie1[1] != ie2[1])
 463                                 return ie2[1] - ie1[1];
 464                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 465                 }
 466         }
 467
 468         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 469         if (r)
 470                 return r;
 471
 472         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 473         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 474
 475         if (!ie1 && !ie2)
 476                 return 0;
 477
 478         /*
 479          * Note that with "hide_ssid", the function returns a match if
 480          * the already-present BSS ("b") is a hidden SSID beacon for
 481          * the new BSS ("a").
 482          */
 483
 484         /* sort missing IE before (left of) present IE */
 485         if (!ie1)
 486                 return -1;
 487         if (!ie2)
 488                 return 1;
 489
 490         switch (mode) {
 491         case BSS_CMP_HIDE_ZLEN:
 492                 /*
 493                  * In ZLEN mode we assume the BSS entry we're
 494                  * looking for has a zero-length SSID. So if
 495                  * the one we're looking at right now has that,
 496                  * return 0. Otherwise, return the difference
 497                  * in length, but since we're looking for the
 498                  * 0-length it's really equivalent to returning
 499                  * the length of the one we're looking at.
 500                  *
 501                  * No content comparison is needed as we assume
 502                  * the content length is zero.
 503                  */
 504                 return ie2[1];
 505         case BSS_CMP_REGULAR:
 506         default:
 507                 /* sort by length first, then by contents */
 508                 if (ie1[1] != ie2[1])
 509                         return ie2[1] - ie1[1];
 510                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 511         case BSS_CMP_HIDE_NUL:
 512                 if (ie1[1] != ie2[1])
 513                         return ie2[1] - ie1[1];
 514                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 515                 for (i = 0; i < ie2[1]; i++)
 516                         if (ie2[i + 2])
 517                                 return -1;
 518                 return 0;
 519         }
 520 }
 521
 522 /* Returned bss is reference counted and must be cleaned up appropriately. */
 523 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 524                                       struct ieee80211_channel *channel,
 525                                       const u8 *bssid,
 526                                       const u8 *ssid, size_t ssid_len,
 527                                       u16 capa_mask, u16 capa_val)
 528 {
 529         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 530         struct cfg80211_internal_bss *bss, *res = NULL;
 531         unsigned long now = jiffies;
 532
 533         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
 534                                capa_val);
 535
 536         spin_lock_bh(&rdev->bss_lock);
 537
 538         list_for_each_entry(bss, &rdev->bss_list, list) {
 539                 if ((bss->pub.capability & capa_mask) != capa_val)
 540                         continue;
 541                 if (channel && bss->pub.channel != channel)
 542                         continue;
 543                 if (!is_valid_ether_addr(bss->pub.bssid))
 544                         continue;
 545                 /* Don't get expired BSS structs */
 546                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 547                     !atomic_read(&bss->hold))
 548                         continue;
 549                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 550                         res = bss;
 551                         bss_ref_get(rdev, res);
 552                         break;
 553                 }
 554         }
 555
 556         spin_unlock_bh(&rdev->bss_lock);
 557         if (!res)
 558                 return NULL;
 559         trace_cfg80211_return_bss(&res->pub);
 560         return &res->pub;
 561 }
 562 EXPORT_SYMBOL(cfg80211_get_bss);
 563
 564 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 565                           struct cfg80211_internal_bss *bss)
 566 {
 567         struct rb_node **p = &rdev->bss_tree.rb_node;
 568         struct rb_node *parent = NULL;
 569         struct cfg80211_internal_bss *tbss;
 570         int cmp;
 571
 572         while (*p) {
 573                 parent = *p;
 574                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 575
 576                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 577
 578                 if (WARN_ON(!cmp)) {
 579                         /* will sort of leak this BSS */
 580                         return;
 581                 }
 582
 583                 if (cmp < 0)
 584                         p = &(*p)->rb_left;
 585                 else
 586                         p = &(*p)->rb_right;
 587         }
 588
 589         rb_link_node(&bss->rbn, parent, p);
 590         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 591 }
 592
 593 static struct cfg80211_internal_bss *
 594 rb_find_bss(struct cfg80211_registered_device *rdev,
 595             struct cfg80211_internal_bss *res,
 596             enum bss_compare_mode mode)
 597 {
 598         struct rb_node *n = rdev->bss_tree.rb_node;
 599         struct cfg80211_internal_bss *bss;
 600         int r;
 601
 602         while (n) {
 603                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 604                 r = cmp_bss(&res->pub, &bss->pub, mode);
 605
 606                 if (r == 0)
 607                         return bss;
 608                 else if (r < 0)
 609                         n = n->rb_left;
 610                 else
 611                         n = n->rb_right;
 612         }
 613
 614         return NULL;
 615 }
 616
 617 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 618                                    struct cfg80211_internal_bss *new)
 619 {
 620         const struct cfg80211_bss_ies *ies;
 621         struct cfg80211_internal_bss *bss;
 622         const u8 *ie;
 623         int i, ssidlen;
 624         u8 fold = 0;
 625
 626         ies = rcu_access_pointer(new->pub.beacon_ies);
 627         if (WARN_ON(!ies))
 628                 return false;
 629
 630         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 631         if (!ie) {
 632                 /* nothing to do */
 633                 return true;
 634         }
 635
 636         ssidlen = ie[1];
 637         for (i = 0; i < ssidlen; i++)
 638                 fold |= ie[2 + i];
 639
 640         if (fold) {
 641                 /* not a hidden SSID */
 642                 return true;
 643         }
 644
 645         /* This is the bad part ... */
 646
 647         list_for_each_entry(bss, &rdev->bss_list, list) {
 648                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 649                         continue;
 650                 if (bss->pub.channel != new->pub.channel)
 651                         continue;
 652                 if (bss->pub.scan_width != new->pub.scan_width)
 653                         continue;
 654                 if (rcu_access_pointer(bss->pub.beacon_ies))
 655                         continue;
 656                 ies = rcu_access_pointer(bss->pub.ies);
 657                 if (!ies)
 658                         continue;
 659                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 660                 if (!ie)
 661                         continue;
 662                 if (ssidlen && ie[1] != ssidlen)
 663                         continue;
 664                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 665                         continue;
 666                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 667                         list_del(&bss->hidden_list);
 668                 /* combine them */
 669                 list_add(&bss->hidden_list, &new->hidden_list);
 670                 bss->pub.hidden_beacon_bss = &new->pub;
 671                 new->refcount += bss->refcount;
 672                 rcu_assign_pointer(bss->pub.beacon_ies,
 673                                    new->pub.beacon_ies);
 674         }
 675
 676         return true;
 677 }
 678
 679 /* Returned bss is reference counted and must be cleaned up appropriately. */
 680 static struct cfg80211_internal_bss *
 681 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 682                     struct cfg80211_internal_bss *tmp,
 683                     bool signal_valid)
 684 {
 685         struct cfg80211_internal_bss *found = NULL;
 686
 687         if (WARN_ON(!tmp->pub.channel))
 688                 return NULL;
 689
 690         tmp->ts = jiffies;
 691
 692         spin_lock_bh(&rdev->bss_lock);
 693
 694         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 695                 spin_unlock_bh(&rdev->bss_lock);
 696                 return NULL;
 697         }
 698
 699         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 700
 701         if (found) {
 702                 /* Update IEs */
 703                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 704                         const struct cfg80211_bss_ies *old;
 705
 706                         old = rcu_access_pointer(found->pub.proberesp_ies);
 707
 708                         rcu_assign_pointer(found->pub.proberesp_ies,
 709                                            tmp->pub.proberesp_ies);
 710                         /* Override possible earlier Beacon frame IEs */
 711                         rcu_assign_pointer(found->pub.ies,
 712                                            tmp->pub.proberesp_ies);
 713                         if (old)
 714                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 715                                           rcu_head);
 716                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 717                         const struct cfg80211_bss_ies *old;
 718                         struct cfg80211_internal_bss *bss;
 719
 720                         if (found->pub.hidden_beacon_bss &&
 721                             !list_empty(&found->hidden_list)) {
 722                                 const struct cfg80211_bss_ies *f;
 723
 724                                 /*
 725                                  * The found BSS struct is one of the probe
 726                                  * response members of a group, but we're
 727                                  * receiving a beacon (beacon_ies in the tmp
 728                                  * bss is used). This can only mean that the
 729                                  * AP changed its beacon from not having an
 730                                  * SSID to showing it, which is confusing so
 731                                  * drop this information.
 732                                  */
 733
 734                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 735                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 736                                           rcu_head);
 737                                 goto drop;
 738                         }
 739
 740                         old = rcu_access_pointer(found->pub.beacon_ies);
 741
 742                         rcu_assign_pointer(found->pub.beacon_ies,
 743                                            tmp->pub.beacon_ies);
 744
 745                         /* Override IEs if they were from a beacon before */
 746                         if (old == rcu_access_pointer(found->pub.ies))
 747                                 rcu_assign_pointer(found->pub.ies,
 748                                                    tmp->pub.beacon_ies);
 749
 750                         /* Assign beacon IEs to all sub entries */
 751                         list_for_each_entry(bss, &found->hidden_list,
 752                                             hidden_list) {
 753                                 const struct cfg80211_bss_ies *ies;
 754
 755                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 756                                 WARN_ON(ies != old);
 757
 758                                 rcu_assign_pointer(bss->pub.beacon_ies,
 759                                                    tmp->pub.beacon_ies);
 760                         }
 761
 762                         if (old)
 763                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 764                                           rcu_head);
 765                 }
 766
 767                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 768                 /*
 769                  * don't update the signal if beacon was heard on
 770                  * adjacent channel.
 771                  */
 772                 if (signal_valid)
 773                         found->pub.signal = tmp->pub.signal;
 774                 found->pub.capability = tmp->pub.capability;
 775                 found->ts = tmp->ts;
 776         } else {
 777                 struct cfg80211_internal_bss *new;
 778                 struct cfg80211_internal_bss *hidden;
 779                 struct cfg80211_bss_ies *ies;
 780
 781                 /*
 782                  * create a copy -- the "res" variable that is passed in
 783                  * is allocated on the stack since it's not needed in the
 784                  * more common case of an update
 785                  */
 786                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 787                               GFP_ATOMIC);
 788                 if (!new) {
 789                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 790                         if (ies)
 791                                 kfree_rcu(ies, rcu_head);
 792                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 793                         if (ies)
 794                                 kfree_rcu(ies, rcu_head);
 795                         goto drop;
 796                 }
 797                 memcpy(new, tmp, sizeof(*new));
 798                 new->refcount = 1;
 799                 INIT_LIST_HEAD(&new->hidden_list);
 800
 801                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 802                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 803                         if (!hidden)
 804                                 hidden = rb_find_bss(rdev, tmp,
 805                                                      BSS_CMP_HIDE_NUL);
 806                         if (hidden) {
 807                                 new->pub.hidden_beacon_bss = &hidden->pub;
 808                                 list_add(&new->hidden_list,
 809                                          &hidden->hidden_list);
 810                                 hidden->refcount++;
 811                                 rcu_assign_pointer(new->pub.beacon_ies,
 812                                                    hidden->pub.beacon_ies);
 813                         }
 814                 } else {
 815                         /*
 816                          * Ok so we found a beacon, and don't have an entry. If
 817                          * it's a beacon with hidden SSID, we might be in for an
 818                          * expensive search for any probe responses that should
 819                          * be grouped with this beacon for updates ...
 820                          */
 821                         if (!cfg80211_combine_bsses(rdev, new)) {
 822                                 kfree(new);
 823                                 goto drop;
 824                         }
 825                 }
 826
 827                 list_add_tail(&new->list, &rdev->bss_list);
 828                 rb_insert_bss(rdev, new);
 829                 found = new;
 830         }
 831
 832         rdev->bss_generation++;
 833         bss_ref_get(rdev, found);
 834         spin_unlock_bh(&rdev->bss_lock);
 835
 836         return found;
 837  drop:
 838         spin_unlock_bh(&rdev->bss_lock);
 839         return NULL;
 840 }
 841
 842 static struct ieee80211_channel *
 843 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 844                          struct ieee80211_channel *channel)
 845 {
 846         const u8 *tmp;
 847         u32 freq;
 848         int channel_number = -1;
 849
 850         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 851         if (tmp && tmp[1] == 1) {
 852                 channel_number = tmp[2];
 853         } else {
 854                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 855                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 856                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 857
 858                         channel_number = htop->primary_chan;
 859                 }
 860         }
 861
 862         if (channel_number < 0)
 863                 return channel;
 864
 865         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 866         channel = ieee80211_get_channel(wiphy, freq);
 867         if (!channel)
 868                 return NULL;
 869         if (channel->flags & IEEE80211_CHAN_DISABLED)
 870                 return NULL;
 871         return channel;
 872 }
 873
 874 /* Returned bss is reference counted and must be cleaned up appropriately. */
 875 struct cfg80211_bss*
 876 cfg80211_inform_bss_width(struct wiphy *wiphy,
 877                           struct ieee80211_channel *rx_channel,
 878                           enum nl80211_bss_scan_width scan_width,
 879                           const u8 *bssid, u64 tsf, u16 capability,
 880                           u16 beacon_interval, const u8 *ie, size_t ielen,
 881                           s32 signal, gfp_t gfp)
 882 {
 883         struct cfg80211_bss_ies *ies;
 884         struct ieee80211_channel *channel;
 885         struct cfg80211_internal_bss tmp = {}, *res;
 886
 887         if (WARN_ON(!wiphy))
 888                 return NULL;
 889
 890         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 891                         (signal < 0 || signal > 100)))
 892                 return NULL;
 893
 894         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
 895         if (!channel)
 896                 return NULL;
 897
 898         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 899         tmp.pub.channel = channel;
 900         tmp.pub.scan_width = scan_width;
 901         tmp.pub.signal = signal;
 902         tmp.pub.beacon_interval = beacon_interval;
 903         tmp.pub.capability = capability;
 904         /*
 905          * Since we do not know here whether the IEs are from a Beacon or Probe
 906          * Response frame, we need to pick one of the options and only use it
 907          * with the driver that does not provide the full Beacon/Probe Response
 908          * frame. Use Beacon frame pointer to avoid indicating that this should
 909          * override the IEs pointer should we have received an earlier
 910          * indication of Probe Response data.
 911          */
 912         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 913         if (!ies)
 914                 return NULL;
 915         ies->len = ielen;
 916         ies->tsf = tsf;
 917         memcpy(ies->data, ie, ielen);
 918
 919         rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 920         rcu_assign_pointer(tmp.pub.ies, ies);
 921
 922         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp,
 923                                   rx_channel == channel);
 924         if (!res)
 925                 return NULL;
 926
 927         if (res->pub.capability & WLAN_CAPABILITY_ESS)
 928                 regulatory_hint_found_beacon(wiphy, channel, gfp);
 929
 930         trace_cfg80211_return_bss(&res->pub);
 931         /* cfg80211_bss_update gives us a referenced result */
 932         return &res->pub;
 933 }
 934 EXPORT_SYMBOL(cfg80211_inform_bss_width);
 935
 936 /* Returned bss is reference counted and must be cleaned up appropriately. */
 937 struct cfg80211_bss *
 938 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
 939                                 struct ieee80211_channel *rx_channel,
 940                                 enum nl80211_bss_scan_width scan_width,
 941                                 struct ieee80211_mgmt *mgmt, size_t len,
 942                                 s32 signal, gfp_t gfp)
 943 {
 944         struct cfg80211_internal_bss tmp = {}, *res;
 945         struct cfg80211_bss_ies *ies;
 946         struct ieee80211_channel *channel;
 947         size_t ielen = len - offsetof(struct ieee80211_mgmt,
 948                                       u.probe_resp.variable);
 949
 950         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
 951                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
 952
 953         trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
 954                                               len, signal);
 955
 956         if (WARN_ON(!mgmt))
 957                 return NULL;
 958
 959         if (WARN_ON(!wiphy))
 960                 return NULL;
 961
 962         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 963                     (signal < 0 || signal > 100)))
 964                 return NULL;
 965
 966         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
 967                 return NULL;
 968
 969         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
 970                                            ielen, rx_channel);
 971         if (!channel)
 972                 return NULL;
 973
 974         ies = kmalloc(sizeof(*ies) + ielen, gfp);
 975         if (!ies)
 976                 return NULL;
 977         ies->len = ielen;
 978         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 979         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 980
 981         if (ieee80211_is_probe_resp(mgmt->frame_control))
 982                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
 983         else
 984                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
 985         rcu_assign_pointer(tmp.pub.ies, ies);
 986
 987         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 988         tmp.pub.channel = channel;
 989         tmp.pub.scan_width = scan_width;
 990         tmp.pub.signal = signal;
 991         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
 992         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
 993
 994         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp,
 995                                   rx_channel == channel);
 996         if (!res)
 997                 return NULL;
 998
 999         if (res->pub.capability & WLAN_CAPABILITY_ESS)
1000                 regulatory_hint_found_beacon(wiphy, channel, gfp);
1001
1002         trace_cfg80211_return_bss(&res->pub);
1003         /* cfg80211_bss_update gives us a referenced result */
1004         return &res->pub;
1005 }
1006 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1007
1008 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1009 {
1010         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1011         struct cfg80211_internal_bss *bss;
1012
1013         if (!pub)
1014                 return;
1015
1016         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1017
1018         spin_lock_bh(&rdev->bss_lock);
1019         bss_ref_get(rdev, bss);
1020         spin_unlock_bh(&rdev->bss_lock);
1021 }
1022 EXPORT_SYMBOL(cfg80211_ref_bss);
1023
1024 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1025 {
1026         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1027         struct cfg80211_internal_bss *bss;
1028
1029         if (!pub)
1030                 return;
1031
1032         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1033
1034         spin_lock_bh(&rdev->bss_lock);
1035         bss_ref_put(rdev, bss);
1036         spin_unlock_bh(&rdev->bss_lock);
1037 }
1038 EXPORT_SYMBOL(cfg80211_put_bss);
1039
1040 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1041 {
1042         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1043         struct cfg80211_internal_bss *bss;
1044
1045         if (WARN_ON(!pub))
1046                 return;
1047
1048         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1049
1050         spin_lock_bh(&rdev->bss_lock);
1051         if (!list_empty(&bss->list)) {
1052                 if (__cfg80211_unlink_bss(rdev, bss))
1053                         rdev->bss_generation++;
1054         }
1055         spin_unlock_bh(&rdev->bss_lock);
1056 }
1057 EXPORT_SYMBOL(cfg80211_unlink_bss);
1058
1059 #ifdef CONFIG_CFG80211_WEXT
1060 static struct cfg80211_registered_device *
1061 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1062 {
1063         struct cfg80211_registered_device *rdev;
1064         struct net_device *dev;
1065
1066         ASSERT_RTNL();
1067
1068         dev = dev_get_by_index(net, ifindex);
1069         if (!dev)
1070                 return ERR_PTR(-ENODEV);
1071         if (dev->ieee80211_ptr)
1072                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1073         else
1074                 rdev = ERR_PTR(-ENODEV);
1075         dev_put(dev);
1076         return rdev;
1077 }
1078
1079 int cfg80211_wext_siwscan(struct net_device *dev,
1080                           struct iw_request_info *info,
1081                           union iwreq_data *wrqu, char *extra)
1082 {
1083         struct cfg80211_registered_device *rdev;
1084         struct wiphy *wiphy;
1085         struct iw_scan_req *wreq = NULL;
1086         struct cfg80211_scan_request *creq = NULL;
1087         int i, err, n_channels = 0;
1088         enum ieee80211_band band;
1089
1090         if (!netif_running(dev))
1091                 return -ENETDOWN;
1092
1093         if (wrqu->data.length == sizeof(struct iw_scan_req))
1094                 wreq = (struct iw_scan_req *)extra;
1095
1096         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1097
1098         if (IS_ERR(rdev))
1099                 return PTR_ERR(rdev);
1100
1101         if (rdev->scan_req || rdev->scan_msg) {
1102                 err = -EBUSY;
1103                 goto out;
1104         }
1105
1106         wiphy = &rdev->wiphy;
1107
1108         /* Determine number of channels, needed to allocate creq */
1109         if (wreq && wreq->num_channels)
1110                 n_channels = wreq->num_channels;
1111         else
1112                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1113
1114         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1115                        n_channels * sizeof(void *),
1116                        GFP_ATOMIC);
1117         if (!creq) {
1118                 err = -ENOMEM;
1119                 goto out;
1120         }
1121
1122         creq->wiphy = wiphy;
1123         creq->wdev = dev->ieee80211_ptr;
1124         /* SSIDs come after channels */
1125         creq->ssids = (void *)&creq->channels[n_channels];
1126         creq->n_channels = n_channels;
1127         creq->n_ssids = 1;
1128         creq->scan_start = jiffies;
1129
1130         /* translate "Scan on frequencies" request */
1131         i = 0;
1132         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1133                 int j;
1134
1135                 if (!wiphy->bands[band])
1136                         continue;
1137
1138                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1139                         /* ignore disabled channels */
1140                         if (wiphy->bands[band]->channels[j].flags &
1141                                                 IEEE80211_CHAN_DISABLED)
1142                                 continue;
1143
1144                         /* If we have a wireless request structure and the
1145                          * wireless request specifies frequencies, then search
1146                          * for the matching hardware channel.
1147                          */
1148                         if (wreq && wreq->num_channels) {
1149                                 int k;
1150                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1151                                 for (k = 0; k < wreq->num_channels; k++) {
1152                                         struct iw_freq *freq =
1153                                                 &wreq->channel_list[k];
1154                                         int wext_freq =
1155                                                 cfg80211_wext_freq(freq);
1156
1157                                         if (wext_freq == wiphy_freq)
1158                                                 goto wext_freq_found;
1159                                 }
1160                                 goto wext_freq_not_found;
1161                         }
1162
1163                 wext_freq_found:
1164                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1165                         i++;
1166                 wext_freq_not_found: ;
1167                 }
1168         }
1169         /* No channels found? */
1170         if (!i) {
1171                 err = -EINVAL;
1172                 goto out;
1173         }
1174
1175         /* Set real number of channels specified in creq->channels[] */
1176         creq->n_channels = i;
1177
1178         /* translate "Scan for SSID" request */
1179         if (wreq) {
1180                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1181                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1182                                 err = -EINVAL;
1183                                 goto out;
1184                         }
1185                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1186                         creq->ssids[0].ssid_len = wreq->essid_len;
1187                 }
1188                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1189                         creq->n_ssids = 0;
1190         }
1191
1192         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1193                 if (wiphy->bands[i])
1194                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1195
1196         rdev->scan_req = creq;
1197         err = rdev_scan(rdev, creq);
1198         if (err) {
1199                 rdev->scan_req = NULL;
1200                 /* creq will be freed below */
1201         } else {
1202                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1203                 /* creq now owned by driver */
1204                 creq = NULL;
1205                 dev_hold(dev);
1206         }
1207  out:
1208         kfree(creq);
1209         return err;
1210 }
1211 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1212
1213 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1214                                    const struct cfg80211_bss_ies *ies,
1215                                    char **current_ev, char *end_buf)
1216 {
1217         const u8 *pos, *end, *next;
1218         struct iw_event iwe;
1219
1220         if (!ies)
1221                 return;
1222
1223         /*
1224          * If needed, fragment the IEs buffer (at IE boundaries) into short
1225          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1226          */
1227         pos = ies->data;
1228         end = pos + ies->len;
1229
1230         while (end - pos > IW_GENERIC_IE_MAX) {
1231                 next = pos + 2 + pos[1];
1232                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1233                         next = next + 2 + next[1];
1234
1235                 memset(&iwe, 0, sizeof(iwe));
1236                 iwe.cmd = IWEVGENIE;
1237                 iwe.u.data.length = next - pos;
1238                 *current_ev = iwe_stream_add_point(info, *current_ev,
1239                                                    end_buf, &iwe,
1240                                                    (void *)pos);
1241
1242                 pos = next;
1243         }
1244
1245         if (end > pos) {
1246                 memset(&iwe, 0, sizeof(iwe));
1247                 iwe.cmd = IWEVGENIE;
1248                 iwe.u.data.length = end - pos;
1249                 *current_ev = iwe_stream_add_point(info, *current_ev,
1250                                                    end_buf, &iwe,
1251                                                    (void *)pos);
1252         }
1253 }
1254
1255 static char *
1256 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1257               struct cfg80211_internal_bss *bss, char *current_ev,
1258               char *end_buf)
1259 {
1260         const struct cfg80211_bss_ies *ies;
1261         struct iw_event iwe;
1262         const u8 *ie;
1263         u8 *buf, *cfg, *p;
1264         int rem, i, sig;
1265         bool ismesh = false;
1266
1267         memset(&iwe, 0, sizeof(iwe));
1268         iwe.cmd = SIOCGIWAP;
1269         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1270         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1271         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1272                                           IW_EV_ADDR_LEN);
1273
1274         memset(&iwe, 0, sizeof(iwe));
1275         iwe.cmd = SIOCGIWFREQ;
1276         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1277         iwe.u.freq.e = 0;
1278         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1279                                           IW_EV_FREQ_LEN);
1280
1281         memset(&iwe, 0, sizeof(iwe));
1282         iwe.cmd = SIOCGIWFREQ;
1283         iwe.u.freq.m = bss->pub.channel->center_freq;
1284         iwe.u.freq.e = 6;
1285         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1286                                           IW_EV_FREQ_LEN);
1287
1288         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1289                 memset(&iwe, 0, sizeof(iwe));
1290                 iwe.cmd = IWEVQUAL;
1291                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1292                                      IW_QUAL_NOISE_INVALID |
1293                                      IW_QUAL_QUAL_UPDATED;
1294                 switch (wiphy->signal_type) {
1295                 case CFG80211_SIGNAL_TYPE_MBM:
1296                         sig = bss->pub.signal / 100;
1297                         iwe.u.qual.level = sig;
1298                         iwe.u.qual.updated |= IW_QUAL_DBM;
1299                         if (sig < -110)         /* rather bad */
1300                                 sig = -110;
1301                         else if (sig > -40)     /* perfect */
1302                                 sig = -40;
1303                         /* will give a range of 0 .. 70 */
1304                         iwe.u.qual.qual = sig + 110;
1305                         break;
1306                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1307                         iwe.u.qual.level = bss->pub.signal;
1308                         /* will give range 0 .. 100 */
1309                         iwe.u.qual.qual = bss->pub.signal;
1310                         break;
1311                 default:
1312                         /* not reached */
1313                         break;
1314                 }
1315                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1316                                                   &iwe, IW_EV_QUAL_LEN);
1317         }
1318
1319         memset(&iwe, 0, sizeof(iwe));
1320         iwe.cmd = SIOCGIWENCODE;
1321         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1322                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1323         else
1324                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1325         iwe.u.data.length = 0;
1326         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1327                                           &iwe, "");
1328
1329         rcu_read_lock();
1330         ies = rcu_dereference(bss->pub.ies);
1331         rem = ies->len;
1332         ie = ies->data;
1333
1334         while (rem >= 2) {
1335                 /* invalid data */
1336                 if (ie[1] > rem - 2)
1337                         break;
1338
1339                 switch (ie[0]) {
1340                 case WLAN_EID_SSID:
1341                         memset(&iwe, 0, sizeof(iwe));
1342                         iwe.cmd = SIOCGIWESSID;
1343                         iwe.u.data.length = ie[1];
1344                         iwe.u.data.flags = 1;
1345                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1346                                                           &iwe, (u8 *)ie + 2);
1347                         break;
1348                 case WLAN_EID_MESH_ID:
1349                         memset(&iwe, 0, sizeof(iwe));
1350                         iwe.cmd = SIOCGIWESSID;
1351                         iwe.u.data.length = ie[1];
1352                         iwe.u.data.flags = 1;
1353                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1354                                                           &iwe, (u8 *)ie + 2);
1355                         break;
1356                 case WLAN_EID_MESH_CONFIG:
1357                         ismesh = true;
1358                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1359                                 break;
1360                         buf = kmalloc(50, GFP_ATOMIC);
1361                         if (!buf)
1362                                 break;
1363                         cfg = (u8 *)ie + 2;
1364                         memset(&iwe, 0, sizeof(iwe));
1365                         iwe.cmd = IWEVCUSTOM;
1366                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1367                                 "0x%02X", cfg[0]);
1368                         iwe.u.data.length = strlen(buf);
1369                         current_ev = iwe_stream_add_point(info, current_ev,
1370                                                           end_buf,
1371                                                           &iwe, buf);
1372                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1373                                 cfg[1]);
1374                         iwe.u.data.length = strlen(buf);
1375                         current_ev = iwe_stream_add_point(info, current_ev,
1376                                                           end_buf,
1377                                                           &iwe, buf);
1378                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1379                                 cfg[2]);
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, "Synchronization ID: 0x%02X", cfg[3]);
1385                         iwe.u.data.length = strlen(buf);
1386                         current_ev = iwe_stream_add_point(info, current_ev,
1387                                                           end_buf,
1388                                                           &iwe, buf);
1389                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1390                         iwe.u.data.length = strlen(buf);
1391                         current_ev = iwe_stream_add_point(info, current_ev,
1392                                                           end_buf,
1393                                                           &iwe, buf);
1394                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1395                         iwe.u.data.length = strlen(buf);
1396                         current_ev = iwe_stream_add_point(info, current_ev,
1397                                                           end_buf,
1398                                                           &iwe, buf);
1399                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1400                         iwe.u.data.length = strlen(buf);
1401                         current_ev = iwe_stream_add_point(info, current_ev,
1402                                                           end_buf,
1403                                                           &iwe, buf);
1404                         kfree(buf);
1405                         break;
1406                 case WLAN_EID_SUPP_RATES:
1407                 case WLAN_EID_EXT_SUPP_RATES:
1408                         /* display all supported rates in readable format */
1409                         p = current_ev + iwe_stream_lcp_len(info);
1410
1411                         memset(&iwe, 0, sizeof(iwe));
1412                         iwe.cmd = SIOCGIWRATE;
1413                         /* Those two flags are ignored... */
1414                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1415
1416                         for (i = 0; i < ie[1]; i++) {
1417                                 iwe.u.bitrate.value =
1418                                         ((ie[i + 2] & 0x7f) * 500000);
1419                                 p = iwe_stream_add_value(info, current_ev, p,
1420                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1421                         }
1422                         current_ev = p;
1423                         break;
1424                 }
1425                 rem -= ie[1] + 2;
1426                 ie += ie[1] + 2;
1427         }
1428
1429         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1430             ismesh) {
1431                 memset(&iwe, 0, sizeof(iwe));
1432                 iwe.cmd = SIOCGIWMODE;
1433                 if (ismesh)
1434                         iwe.u.mode = IW_MODE_MESH;
1435                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1436                         iwe.u.mode = IW_MODE_MASTER;
1437                 else
1438                         iwe.u.mode = IW_MODE_ADHOC;
1439                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1440                                                   &iwe, IW_EV_UINT_LEN);
1441         }
1442
1443         buf = kmalloc(31, GFP_ATOMIC);
1444         if (buf) {
1445                 memset(&iwe, 0, sizeof(iwe));
1446                 iwe.cmd = IWEVCUSTOM;
1447                 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1448                 iwe.u.data.length = strlen(buf);
1449                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1450                                                   &iwe, buf);
1451                 memset(&iwe, 0, sizeof(iwe));
1452                 iwe.cmd = IWEVCUSTOM;
1453                 sprintf(buf, " Last beacon: %ums ago",
1454                         elapsed_jiffies_msecs(bss->ts));
1455                 iwe.u.data.length = strlen(buf);
1456                 current_ev = iwe_stream_add_point(info, current_ev,
1457                                                   end_buf, &iwe, buf);
1458                 kfree(buf);
1459         }
1460
1461         ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1462         rcu_read_unlock();
1463
1464         return current_ev;
1465 }
1466
1467
1468 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1469                                   struct iw_request_info *info,
1470                                   char *buf, size_t len)
1471 {
1472         char *current_ev = buf;
1473         char *end_buf = buf + len;
1474         struct cfg80211_internal_bss *bss;
1475
1476         spin_lock_bh(&rdev->bss_lock);
1477         cfg80211_bss_expire(rdev);
1478
1479         list_for_each_entry(bss, &rdev->bss_list, list) {
1480                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1481                         spin_unlock_bh(&rdev->bss_lock);
1482                         return -E2BIG;
1483                 }
1484                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1485                                            current_ev, end_buf);
1486         }
1487         spin_unlock_bh(&rdev->bss_lock);
1488         return current_ev - buf;
1489 }
1490
1491
1492 int cfg80211_wext_giwscan(struct net_device *dev,
1493                           struct iw_request_info *info,
1494                           struct iw_point *data, char *extra)
1495 {
1496         struct cfg80211_registered_device *rdev;
1497         int res;
1498
1499         if (!netif_running(dev))
1500                 return -ENETDOWN;
1501
1502         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1503
1504         if (IS_ERR(rdev))
1505                 return PTR_ERR(rdev);
1506
1507         if (rdev->scan_req || rdev->scan_msg)
1508                 return -EAGAIN;
1509
1510         res = ieee80211_scan_results(rdev, info, extra, data->length);
1511         data->length = 0;
1512         if (res >= 0) {
1513                 data->length = res;
1514                 res = 0;
1515         }
1516
1517         return res;
1518 }
1519 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1520 #endif