net/wireless/scan.c

   1 /*
   2  * cfg80211 scan result handling
   3  *
   4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
   5  * Copyright 2013-2014  Intel Mobile Communications GmbH
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/wireless.h>
  12 #include <linux/nl80211.h>
  13 #include <linux/etherdevice.h>
  14 #include <net/arp.h>
  15 #include <net/cfg80211.h>
  16 #include <net/cfg80211-wext.h>
  17 #include <net/iw_handler.h>
  18 #include "core.h"
  19 #include "nl80211.h"
  20 #include "wext-compat.h"
  21 #include "rdev-ops.h"
  22
  23 /**
  24  * DOC: BSS tree/list structure
  25  *
  26  * At the top level, the BSS list is kept in both a list in each
  27  * registered device (@bss_list) as well as an RB-tree for faster
  28  * lookup. In the RB-tree, entries can be looked up using their
  29  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  30  * for other BSSes.
  31  *
  32  * Due to the possibility of hidden SSIDs, there's a second level
  33  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  34  * The hidden_list connects all BSSes belonging to a single AP
  35  * that has a hidden SSID, and connects beacon and probe response
  36  * entries. For a probe response entry for a hidden SSID, the
  37  * hidden_beacon_bss pointer points to the BSS struct holding the
  38  * beacon's information.
  39  *
  40  * Reference counting is done for all these references except for
  41  * the hidden_list, so that a beacon BSS struct that is otherwise
  42  * not referenced has one reference for being on the bss_list and
  43  * one for each probe response entry that points to it using the
  44  * hidden_beacon_bss pointer. When a BSS struct that has such a
  45  * pointer is get/put, the refcount update is also propagated to
  46  * the referenced struct, this ensure that it cannot get removed
  47  * while somebody is using the probe response version.
  48  *
  49  * Note that the hidden_beacon_bss pointer never changes, due to
  50  * the reference counting. Therefore, no locking is needed for
  51  * it.
  52  *
  53  * Also note that the hidden_beacon_bss pointer is only relevant
  54  * if the driver uses something other than the IEs, e.g. private
  55  * data stored stored in the BSS struct, since the beacon IEs are
  56  * also linked into the probe response struct.
  57  */
  58
  59 /*
  60  * Limit the number of BSS entries stored in mac80211. Each one is
  61  * a bit over 4k at most, so this limits to roughly 4-5M of memory.
  62  * If somebody wants to really attack this though, they'd likely
  63  * use small beacons, and only one type of frame, limiting each of
  64  * the entries to a much smaller size (in order to generate more
  65  * entries in total, so overhead is bigger.)
  66  */
  67 static int bss_entries_limit = 1000;
  68 module_param(bss_entries_limit, int, 0644);
  69 MODULE_PARM_DESC(bss_entries_limit,
  70                  "limit to number of scan BSS entries (per wiphy, default 1000)");
  71
  72 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  73
  74 static void bss_free(struct cfg80211_internal_bss *bss)
  75 {
  76         struct cfg80211_bss_ies *ies;
  77
  78         if (WARN_ON(atomic_read(&bss->hold)))
  79                 return;
  80
  81         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  82         if (ies && !bss->pub.hidden_beacon_bss)
  83                 kfree_rcu(ies, rcu_head);
  84         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  85         if (ies)
  86                 kfree_rcu(ies, rcu_head);
  87
  88         /*
  89          * This happens when the module is removed, it doesn't
  90          * really matter any more save for completeness
  91          */
  92         if (!list_empty(&bss->hidden_list))
  93                 list_del(&bss->hidden_list);
  94
  95         kfree(bss);
  96 }
  97
  98 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
  99                                struct cfg80211_internal_bss *bss)
 100 {
 101         lockdep_assert_held(&rdev->bss_lock);
 102
 103         bss->refcount++;
 104         if (bss->pub.hidden_beacon_bss) {
 105                 bss = container_of(bss->pub.hidden_beacon_bss,
 106                                    struct cfg80211_internal_bss,
 107                                    pub);
 108                 bss->refcount++;
 109         }
 110 }
 111
 112 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
 113                                struct cfg80211_internal_bss *bss)
 114 {
 115         lockdep_assert_held(&rdev->bss_lock);
 116
 117         if (bss->pub.hidden_beacon_bss) {
 118                 struct cfg80211_internal_bss *hbss;
 119                 hbss = container_of(bss->pub.hidden_beacon_bss,
 120                                     struct cfg80211_internal_bss,
 121                                     pub);
 122                 hbss->refcount--;
 123                 if (hbss->refcount == 0)
 124                         bss_free(hbss);
 125         }
 126         bss->refcount--;
 127         if (bss->refcount == 0)
 128                 bss_free(bss);
 129 }
 130
 131 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 132                                   struct cfg80211_internal_bss *bss)
 133 {
 134         lockdep_assert_held(&rdev->bss_lock);
 135
 136         if (!list_empty(&bss->hidden_list)) {
 137                 /*
 138                  * don't remove the beacon entry if it has
 139                  * probe responses associated with it
 140                  */
 141                 if (!bss->pub.hidden_beacon_bss)
 142                         return false;
 143                 /*
 144                  * if it's a probe response entry break its
 145                  * link to the other entries in the group
 146                  */
 147                 list_del_init(&bss->hidden_list);
 148         }
 149
 150         list_del_init(&bss->list);
 151         rb_erase(&bss->rbn, &rdev->bss_tree);
 152         rdev->bss_entries--;
 153         WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
 154                   "rdev bss entries[%d]/list[empty:%d] corruption\n",
 155                   rdev->bss_entries, list_empty(&rdev->bss_list));
 156         bss_ref_put(rdev, bss);
 157         return true;
 158 }
 159
 160 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 161                                   unsigned long expire_time)
 162 {
 163         struct cfg80211_internal_bss *bss, *tmp;
 164         bool expired = false;
 165
 166         lockdep_assert_held(&rdev->bss_lock);
 167
 168         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
 169                 if (atomic_read(&bss->hold))
 170                         continue;
 171                 if (!time_after(expire_time, bss->ts))
 172                         continue;
 173
 174                 if (__cfg80211_unlink_bss(rdev, bss))
 175                         expired = true;
 176         }
 177
 178         if (expired)
 179                 rdev->bss_generation++;
 180 }
 181
 182 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
 183 {
 184         struct cfg80211_internal_bss *bss, *oldest = NULL;
 185         bool ret;
 186
 187         lockdep_assert_held(&rdev->bss_lock);
 188
 189         list_for_each_entry(bss, &rdev->bss_list, list) {
 190                 if (atomic_read(&bss->hold))
 191                         continue;
 192
 193                 if (!list_empty(&bss->hidden_list) &&
 194                     !bss->pub.hidden_beacon_bss)
 195                         continue;
 196
 197                 if (oldest && time_before(oldest->ts, bss->ts))
 198                         continue;
 199                 oldest = bss;
 200         }
 201
 202         if (WARN_ON(!oldest))
 203                 return false;
 204
 205         /*
 206          * The callers make sure to increase rdev->bss_generation if anything
 207          * gets removed (and a new entry added), so there's no need to also do
 208          * it here.
 209          */
 210
 211         ret = __cfg80211_unlink_bss(rdev, oldest);
 212         WARN_ON(!ret);
 213         return ret;
 214 }
 215
 216 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 217                            bool send_message)
 218 {
 219         struct cfg80211_scan_request *request;
 220         struct wireless_dev *wdev;
 221         struct sk_buff *msg;
 222 #ifdef CONFIG_CFG80211_WEXT
 223         union iwreq_data wrqu;
 224 #endif
 225
 226         ASSERT_RTNL();
 227
 228         if (rdev->scan_msg) {
 229                 nl80211_send_scan_result(rdev, rdev->scan_msg);
 230                 rdev->scan_msg = NULL;
 231                 return;
 232         }
 233
 234         request = rdev->scan_req;
 235         if (!request)
 236                 return;
 237
 238         wdev = request->wdev;
 239
 240         /*
 241          * This must be before sending the other events!
 242          * Otherwise, wpa_supplicant gets completely confused with
 243          * wext events.
 244          */
 245         if (wdev->netdev)
 246                 cfg80211_sme_scan_done(wdev->netdev);
 247
 248         if (!request->aborted &&
 249             request->flags & NL80211_SCAN_FLAG_FLUSH) {
 250                 /* flush entries from previous scans */
 251                 spin_lock_bh(&rdev->bss_lock);
 252                 __cfg80211_bss_expire(rdev, request->scan_start);
 253                 spin_unlock_bh(&rdev->bss_lock);
 254         }
 255
 256         msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
 257
 258 #ifdef CONFIG_CFG80211_WEXT
 259         if (wdev->netdev && !request->aborted) {
 260                 memset(&wrqu, 0, sizeof(wrqu));
 261
 262                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 263         }
 264 #endif
 265
 266         if (wdev->netdev)
 267                 dev_put(wdev->netdev);
 268
 269         rdev->scan_req = NULL;
 270         kfree(request);
 271
 272         if (!send_message)
 273                 rdev->scan_msg = msg;
 274         else
 275                 nl80211_send_scan_result(rdev, msg);
 276 }
 277
 278 void __cfg80211_scan_done(struct work_struct *wk)
 279 {
 280         struct cfg80211_registered_device *rdev;
 281
 282         rdev = container_of(wk, struct cfg80211_registered_device,
 283                             scan_done_wk);
 284
 285         rtnl_lock();
 286         ___cfg80211_scan_done(rdev, true);
 287         rtnl_unlock();
 288 }
 289
 290 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
 291 {
 292         trace_cfg80211_scan_done(request, aborted);
 293         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
 294
 295         request->aborted = aborted;
 296         request->notified = true;
 297         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
 298 }
 299 EXPORT_SYMBOL(cfg80211_scan_done);
 300
 301 void __cfg80211_sched_scan_results(struct work_struct *wk)
 302 {
 303         struct cfg80211_registered_device *rdev;
 304         struct cfg80211_sched_scan_request *request;
 305
 306         rdev = container_of(wk, struct cfg80211_registered_device,
 307                             sched_scan_results_wk);
 308
 309         rtnl_lock();
 310
 311         request = rtnl_dereference(rdev->sched_scan_req);
 312
 313         /* we don't have sched_scan_req anymore if the scan is stopping */
 314         if (request) {
 315                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 316                         /* flush entries from previous scans */
 317                         spin_lock_bh(&rdev->bss_lock);
 318                         __cfg80211_bss_expire(rdev, request->scan_start);
 319                         spin_unlock_bh(&rdev->bss_lock);
 320                         request->scan_start = jiffies;
 321                 }
 322                 nl80211_send_sched_scan_results(rdev, request->dev);
 323         }
 324
 325         rtnl_unlock();
 326 }
 327
 328 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 329 {
 330         trace_cfg80211_sched_scan_results(wiphy);
 331         /* ignore if we're not scanning */
 332
 333         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
 334                 queue_work(cfg80211_wq,
 335                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
 336 }
 337 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 338
 339 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
 340 {
 341         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 342
 343         ASSERT_RTNL();
 344
 345         trace_cfg80211_sched_scan_stopped(wiphy);
 346
 347         __cfg80211_stop_sched_scan(rdev, true);
 348 }
 349 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 350
 351 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 352 {
 353         rtnl_lock();
 354         cfg80211_sched_scan_stopped_rtnl(wiphy);
 355         rtnl_unlock();
 356 }
 357 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 358
 359 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 360                                bool driver_initiated)
 361 {
 362         struct cfg80211_sched_scan_request *sched_scan_req;
 363         struct net_device *dev;
 364
 365         ASSERT_RTNL();
 366
 367         if (!rdev->sched_scan_req)
 368                 return -ENOENT;
 369
 370         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
 371         dev = sched_scan_req->dev;
 372
 373         if (!driver_initiated) {
 374                 int err = rdev_sched_scan_stop(rdev, dev);
 375                 if (err)
 376                         return err;
 377         }
 378
 379         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 380
 381         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
 382         kfree_rcu(sched_scan_req, rcu_head);
 383
 384         return 0;
 385 }
 386
 387 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 388                       unsigned long age_secs)
 389 {
 390         struct cfg80211_internal_bss *bss;
 391         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 392
 393         spin_lock_bh(&rdev->bss_lock);
 394         list_for_each_entry(bss, &rdev->bss_list, list)
 395                 bss->ts -= age_jiffies;
 396         spin_unlock_bh(&rdev->bss_lock);
 397 }
 398
 399 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 400 {
 401         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 402 }
 403
 404 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 405 {
 406         while (len > 2 && ies[0] != eid) {
 407                 len -= ies[1] + 2;
 408                 ies += ies[1] + 2;
 409         }
 410         if (len < 2)
 411                 return NULL;
 412         if (len < 2 + ies[1])
 413                 return NULL;
 414         return ies;
 415 }
 416 EXPORT_SYMBOL(cfg80211_find_ie);
 417
 418 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 419                                   const u8 *ies, int len)
 420 {
 421         struct ieee80211_vendor_ie *ie;
 422         const u8 *pos = ies, *end = ies + len;
 423         int ie_oui;
 424
 425         while (pos < end) {
 426                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 427                                        end - pos);
 428                 if (!pos)
 429                         return NULL;
 430
 431                 ie = (struct ieee80211_vendor_ie *)pos;
 432
 433                 /* make sure we can access ie->len */
 434                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 435
 436                 if (ie->len < sizeof(*ie))
 437                         goto cont;
 438
 439                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 440                 if (ie_oui == oui && ie->oui_type == oui_type)
 441                         return pos;
 442 cont:
 443                 pos += 2 + ie->len;
 444         }
 445         return NULL;
 446 }
 447 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 448
 449 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 450                    const u8 *ssid, size_t ssid_len)
 451 {
 452         const struct cfg80211_bss_ies *ies;
 453         const u8 *ssidie;
 454
 455         if (bssid && !ether_addr_equal(a->bssid, bssid))
 456                 return false;
 457
 458         if (!ssid)
 459                 return true;
 460
 461         ies = rcu_access_pointer(a->ies);
 462         if (!ies)
 463                 return false;
 464         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 465         if (!ssidie)
 466                 return false;
 467         if (ssidie[1] != ssid_len)
 468                 return false;
 469         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 470 }
 471
 472 /**
 473  * enum bss_compare_mode - BSS compare mode
 474  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 475  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 476  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 477  */
 478 enum bss_compare_mode {
 479         BSS_CMP_REGULAR,
 480         BSS_CMP_HIDE_ZLEN,
 481         BSS_CMP_HIDE_NUL,
 482 };
 483
 484 static int cmp_bss(struct cfg80211_bss *a,
 485                    struct cfg80211_bss *b,
 486                    enum bss_compare_mode mode)
 487 {
 488         const struct cfg80211_bss_ies *a_ies, *b_ies;
 489         const u8 *ie1 = NULL;
 490         const u8 *ie2 = NULL;
 491         int i, r;
 492
 493         if (a->channel != b->channel)
 494                 return b->channel->center_freq - a->channel->center_freq;
 495
 496         a_ies = rcu_access_pointer(a->ies);
 497         if (!a_ies)
 498                 return -1;
 499         b_ies = rcu_access_pointer(b->ies);
 500         if (!b_ies)
 501                 return 1;
 502
 503         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 504                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 505                                        a_ies->data, a_ies->len);
 506         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 507                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 508                                        b_ies->data, b_ies->len);
 509         if (ie1 && ie2) {
 510                 int mesh_id_cmp;
 511
 512                 if (ie1[1] == ie2[1])
 513                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 514                 else
 515                         mesh_id_cmp = ie2[1] - ie1[1];
 516
 517                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 518                                        a_ies->data, a_ies->len);
 519                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 520                                        b_ies->data, b_ies->len);
 521                 if (ie1 && ie2) {
 522                         if (mesh_id_cmp)
 523                                 return mesh_id_cmp;
 524                         if (ie1[1] != ie2[1])
 525                                 return ie2[1] - ie1[1];
 526                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 527                 }
 528         }
 529
 530         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 531         if (r)
 532                 return r;
 533
 534         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 535         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 536
 537         if (!ie1 && !ie2)
 538                 return 0;
 539
 540         /*
 541          * Note that with "hide_ssid", the function returns a match if
 542          * the already-present BSS ("b") is a hidden SSID beacon for
 543          * the new BSS ("a").
 544          */
 545
 546         /* sort missing IE before (left of) present IE */
 547         if (!ie1)
 548                 return -1;
 549         if (!ie2)
 550                 return 1;
 551
 552         switch (mode) {
 553         case BSS_CMP_HIDE_ZLEN:
 554                 /*
 555                  * In ZLEN mode we assume the BSS entry we're
 556                  * looking for has a zero-length SSID. So if
 557                  * the one we're looking at right now has that,
 558                  * return 0. Otherwise, return the difference
 559                  * in length, but since we're looking for the
 560                  * 0-length it's really equivalent to returning
 561                  * the length of the one we're looking at.
 562                  *
 563                  * No content comparison is needed as we assume
 564                  * the content length is zero.
 565                  */
 566                 return ie2[1];
 567         case BSS_CMP_REGULAR:
 568         default:
 569                 /* sort by length first, then by contents */
 570                 if (ie1[1] != ie2[1])
 571                         return ie2[1] - ie1[1];
 572                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 573         case BSS_CMP_HIDE_NUL:
 574                 if (ie1[1] != ie2[1])
 575                         return ie2[1] - ie1[1];
 576                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 577                 for (i = 0; i < ie2[1]; i++)
 578                         if (ie2[i + 2])
 579                                 return -1;
 580                 return 0;
 581         }
 582 }
 583
 584 static bool cfg80211_bss_type_match(u16 capability,
 585                                     enum ieee80211_band band,
 586                                     enum ieee80211_bss_type bss_type)
 587 {
 588         bool ret = true;
 589         u16 mask, val;
 590
 591         if (bss_type == IEEE80211_BSS_TYPE_ANY)
 592                 return ret;
 593
 594         if (band == IEEE80211_BAND_60GHZ) {
 595                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
 596                 switch (bss_type) {
 597                 case IEEE80211_BSS_TYPE_ESS:
 598                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
 599                         break;
 600                 case IEEE80211_BSS_TYPE_PBSS:
 601                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
 602                         break;
 603                 case IEEE80211_BSS_TYPE_IBSS:
 604                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
 605                         break;
 606                 default:
 607                         return false;
 608                 }
 609         } else {
 610                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
 611                 switch (bss_type) {
 612                 case IEEE80211_BSS_TYPE_ESS:
 613                         val = WLAN_CAPABILITY_ESS;
 614                         break;
 615                 case IEEE80211_BSS_TYPE_IBSS:
 616                         val = WLAN_CAPABILITY_IBSS;
 617                         break;
 618                 case IEEE80211_BSS_TYPE_MBSS:
 619                         val = 0;
 620                         break;
 621                 default:
 622                         return false;
 623                 }
 624         }
 625
 626         ret = ((capability & mask) == val);
 627         return ret;
 628 }
 629
 630 /* Returned bss is reference counted and must be cleaned up appropriately. */
 631 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 632                                       struct ieee80211_channel *channel,
 633                                       const u8 *bssid,
 634                                       const u8 *ssid, size_t ssid_len,
 635                                       enum ieee80211_bss_type bss_type,
 636                                       enum ieee80211_privacy privacy)
 637 {
 638         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 639         struct cfg80211_internal_bss *bss, *res = NULL;
 640         unsigned long now = jiffies;
 641         int bss_privacy;
 642
 643         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
 644                                privacy);
 645
 646         spin_lock_bh(&rdev->bss_lock);
 647
 648         list_for_each_entry(bss, &rdev->bss_list, list) {
 649                 if (!cfg80211_bss_type_match(bss->pub.capability,
 650                                              bss->pub.channel->band, bss_type))
 651                         continue;
 652
 653                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
 654                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
 655                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
 656                         continue;
 657                 if (channel && bss->pub.channel != channel)
 658                         continue;
 659                 if (!is_valid_ether_addr(bss->pub.bssid))
 660                         continue;
 661                 /* Don't get expired BSS structs */
 662                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 663                     !atomic_read(&bss->hold))
 664                         continue;
 665                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 666                         res = bss;
 667                         bss_ref_get(rdev, res);
 668                         break;
 669                 }
 670         }
 671
 672         spin_unlock_bh(&rdev->bss_lock);
 673         if (!res)
 674                 return NULL;
 675         trace_cfg80211_return_bss(&res->pub);
 676         return &res->pub;
 677 }
 678 EXPORT_SYMBOL(cfg80211_get_bss);
 679
 680 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 681                           struct cfg80211_internal_bss *bss)
 682 {
 683         struct rb_node **p = &rdev->bss_tree.rb_node;
 684         struct rb_node *parent = NULL;
 685         struct cfg80211_internal_bss *tbss;
 686         int cmp;
 687
 688         while (*p) {
 689                 parent = *p;
 690                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 691
 692                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 693
 694                 if (WARN_ON(!cmp)) {
 695                         /* will sort of leak this BSS */
 696                         return;
 697                 }
 698
 699                 if (cmp < 0)
 700                         p = &(*p)->rb_left;
 701                 else
 702                         p = &(*p)->rb_right;
 703         }
 704
 705         rb_link_node(&bss->rbn, parent, p);
 706         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 707 }
 708
 709 static struct cfg80211_internal_bss *
 710 rb_find_bss(struct cfg80211_registered_device *rdev,
 711             struct cfg80211_internal_bss *res,
 712             enum bss_compare_mode mode)
 713 {
 714         struct rb_node *n = rdev->bss_tree.rb_node;
 715         struct cfg80211_internal_bss *bss;
 716         int r;
 717
 718         while (n) {
 719                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 720                 r = cmp_bss(&res->pub, &bss->pub, mode);
 721
 722                 if (r == 0)
 723                         return bss;
 724                 else if (r < 0)
 725                         n = n->rb_left;
 726                 else
 727                         n = n->rb_right;
 728         }
 729
 730         return NULL;
 731 }
 732
 733 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 734                                    struct cfg80211_internal_bss *new)
 735 {
 736         const struct cfg80211_bss_ies *ies;
 737         struct cfg80211_internal_bss *bss;
 738         const u8 *ie;
 739         int i, ssidlen;
 740         u8 fold = 0;
 741         u32 n_entries = 0;
 742
 743         ies = rcu_access_pointer(new->pub.beacon_ies);
 744         if (WARN_ON(!ies))
 745                 return false;
 746
 747         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 748         if (!ie) {
 749                 /* nothing to do */
 750                 return true;
 751         }
 752
 753         ssidlen = ie[1];
 754         for (i = 0; i < ssidlen; i++)
 755                 fold |= ie[2 + i];
 756
 757         if (fold) {
 758                 /* not a hidden SSID */
 759                 return true;
 760         }
 761
 762         /* This is the bad part ... */
 763
 764         list_for_each_entry(bss, &rdev->bss_list, list) {
 765                 /*
 766                  * we're iterating all the entries anyway, so take the
 767                  * opportunity to validate the list length accounting
 768                  */
 769                 n_entries++;
 770
 771                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 772                         continue;
 773                 if (bss->pub.channel != new->pub.channel)
 774                         continue;
 775                 if (bss->pub.scan_width != new->pub.scan_width)
 776                         continue;
 777                 if (rcu_access_pointer(bss->pub.beacon_ies))
 778                         continue;
 779                 ies = rcu_access_pointer(bss->pub.ies);
 780                 if (!ies)
 781                         continue;
 782                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 783                 if (!ie)
 784                         continue;
 785                 if (ssidlen && ie[1] != ssidlen)
 786                         continue;
 787                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 788                         continue;
 789                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 790                         list_del(&bss->hidden_list);
 791                 /* combine them */
 792                 list_add(&bss->hidden_list, &new->hidden_list);
 793                 bss->pub.hidden_beacon_bss = &new->pub;
 794                 new->refcount += bss->refcount;
 795                 rcu_assign_pointer(bss->pub.beacon_ies,
 796                                    new->pub.beacon_ies);
 797         }
 798
 799         WARN_ONCE(n_entries != rdev->bss_entries,
 800                   "rdev bss entries[%d]/list[len:%d] corruption\n",
 801                   rdev->bss_entries, n_entries);
 802
 803         return true;
 804 }
 805
 806 /* Returned bss is reference counted and must be cleaned up appropriately. */
 807 static struct cfg80211_internal_bss *
 808 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 809                     struct cfg80211_internal_bss *tmp,
 810                     bool signal_valid)
 811 {
 812         struct cfg80211_internal_bss *found = NULL;
 813
 814         if (WARN_ON(!tmp->pub.channel))
 815                 return NULL;
 816
 817         tmp->ts = jiffies;
 818
 819         spin_lock_bh(&rdev->bss_lock);
 820
 821         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 822                 spin_unlock_bh(&rdev->bss_lock);
 823                 return NULL;
 824         }
 825
 826         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 827
 828         if (found) {
 829                 /* Update IEs */
 830                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 831                         const struct cfg80211_bss_ies *old;
 832
 833                         old = rcu_access_pointer(found->pub.proberesp_ies);
 834
 835                         rcu_assign_pointer(found->pub.proberesp_ies,
 836                                            tmp->pub.proberesp_ies);
 837                         /* Override possible earlier Beacon frame IEs */
 838                         rcu_assign_pointer(found->pub.ies,
 839                                            tmp->pub.proberesp_ies);
 840                         if (old)
 841                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 842                                           rcu_head);
 843                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 844                         const struct cfg80211_bss_ies *old;
 845                         struct cfg80211_internal_bss *bss;
 846
 847                         if (found->pub.hidden_beacon_bss &&
 848                             !list_empty(&found->hidden_list)) {
 849                                 const struct cfg80211_bss_ies *f;
 850
 851                                 /*
 852                                  * The found BSS struct is one of the probe
 853                                  * response members of a group, but we're
 854                                  * receiving a beacon (beacon_ies in the tmp
 855                                  * bss is used). This can only mean that the
 856                                  * AP changed its beacon from not having an
 857                                  * SSID to showing it, which is confusing so
 858                                  * drop this information.
 859                                  */
 860
 861                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 862                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 863                                           rcu_head);
 864                                 goto drop;
 865                         }
 866
 867                         old = rcu_access_pointer(found->pub.beacon_ies);
 868
 869                         rcu_assign_pointer(found->pub.beacon_ies,
 870                                            tmp->pub.beacon_ies);
 871
 872                         /* Override IEs if they were from a beacon before */
 873                         if (old == rcu_access_pointer(found->pub.ies))
 874                                 rcu_assign_pointer(found->pub.ies,
 875                                                    tmp->pub.beacon_ies);
 876
 877                         /* Assign beacon IEs to all sub entries */
 878                         list_for_each_entry(bss, &found->hidden_list,
 879                                             hidden_list) {
 880                                 const struct cfg80211_bss_ies *ies;
 881
 882                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 883                                 WARN_ON(ies != old);
 884
 885                                 rcu_assign_pointer(bss->pub.beacon_ies,
 886                                                    tmp->pub.beacon_ies);
 887                         }
 888
 889                         if (old)
 890                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 891                                           rcu_head);
 892                 }
 893
 894                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 895                 /*
 896                  * don't update the signal if beacon was heard on
 897                  * adjacent channel.
 898                  */
 899                 if (signal_valid)
 900                         found->pub.signal = tmp->pub.signal;
 901                 found->pub.capability = tmp->pub.capability;
 902                 found->ts = tmp->ts;
 903                 found->ts_boottime = tmp->ts_boottime;
 904         } else {
 905                 struct cfg80211_internal_bss *new;
 906                 struct cfg80211_internal_bss *hidden;
 907                 struct cfg80211_bss_ies *ies;
 908
 909                 /*
 910                  * create a copy -- the "res" variable that is passed in
 911                  * is allocated on the stack since it's not needed in the
 912                  * more common case of an update
 913                  */
 914                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 915                               GFP_ATOMIC);
 916                 if (!new) {
 917                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 918                         if (ies)
 919                                 kfree_rcu(ies, rcu_head);
 920                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 921                         if (ies)
 922                                 kfree_rcu(ies, rcu_head);
 923                         goto drop;
 924                 }
 925                 memcpy(new, tmp, sizeof(*new));
 926                 new->refcount = 1;
 927                 INIT_LIST_HEAD(&new->hidden_list);
 928
 929                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 930                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 931                         if (!hidden)
 932                                 hidden = rb_find_bss(rdev, tmp,
 933                                                      BSS_CMP_HIDE_NUL);
 934                         if (hidden) {
 935                                 new->pub.hidden_beacon_bss = &hidden->pub;
 936                                 list_add(&new->hidden_list,
 937                                          &hidden->hidden_list);
 938                                 hidden->refcount++;
 939                                 rcu_assign_pointer(new->pub.beacon_ies,
 940                                                    hidden->pub.beacon_ies);
 941                         }
 942                 } else {
 943                         /*
 944                          * Ok so we found a beacon, and don't have an entry. If
 945                          * it's a beacon with hidden SSID, we might be in for an
 946                          * expensive search for any probe responses that should
 947                          * be grouped with this beacon for updates ...
 948                          */
 949                         if (!cfg80211_combine_bsses(rdev, new)) {
 950                                 kfree(new);
 951                                 goto drop;
 952                         }
 953                 }
 954
 955                 if (rdev->bss_entries >= bss_entries_limit &&
 956                     !cfg80211_bss_expire_oldest(rdev)) {
 957                         kfree(new);
 958                         goto drop;
 959                 }
 960
 961                 list_add_tail(&new->list, &rdev->bss_list);
 962                 rdev->bss_entries++;
 963                 rb_insert_bss(rdev, new);
 964                 found = new;
 965         }
 966
 967         rdev->bss_generation++;
 968         bss_ref_get(rdev, found);
 969         spin_unlock_bh(&rdev->bss_lock);
 970
 971         return found;
 972  drop:
 973         spin_unlock_bh(&rdev->bss_lock);
 974         return NULL;
 975 }
 976
 977 static struct ieee80211_channel *
 978 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 979                          struct ieee80211_channel *channel)
 980 {
 981         const u8 *tmp;
 982         u32 freq;
 983         int channel_number = -1;
 984
 985         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 986         if (tmp && tmp[1] == 1) {
 987                 channel_number = tmp[2];
 988         } else {
 989                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 990                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 991                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 992
 993                         channel_number = htop->primary_chan;
 994                 }
 995         }
 996
 997         if (channel_number < 0)
 998                 return channel;
 999
1000         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
1001         channel = ieee80211_get_channel(wiphy, freq);
1002         if (!channel)
1003                 return NULL;
1004         if (channel->flags & IEEE80211_CHAN_DISABLED)
1005                 return NULL;
1006         return channel;
1007 }
1008
1009 /* Returned bss is reference counted and must be cleaned up appropriately. */
1010 struct cfg80211_bss *
1011 cfg80211_inform_bss_data(struct wiphy *wiphy,
1012                          struct cfg80211_inform_bss *data,
1013                          enum cfg80211_bss_frame_type ftype,
1014                          const u8 *bssid, u64 tsf, u16 capability,
1015                          u16 beacon_interval, const u8 *ie, size_t ielen,
1016                          gfp_t gfp)
1017 {
1018         struct cfg80211_bss_ies *ies;
1019         struct ieee80211_channel *channel;
1020         struct cfg80211_internal_bss tmp = {}, *res;
1021         int bss_type;
1022         bool signal_valid;
1023
1024         if (WARN_ON(!wiphy))
1025                 return NULL;
1026
1027         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1028                     (data->signal < 0 || data->signal > 100)))
1029                 return NULL;
1030
1031         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
1032         if (!channel)
1033                 return NULL;
1034
1035         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
1036         tmp.pub.channel = channel;
1037         tmp.pub.scan_width = data->scan_width;
1038         tmp.pub.signal = data->signal;
1039         tmp.pub.beacon_interval = beacon_interval;
1040         tmp.pub.capability = capability;
1041         tmp.ts_boottime = data->boottime_ns;
1042
1043         /*
1044          * If we do not know here whether the IEs are from a Beacon or Probe
1045          * Response frame, we need to pick one of the options and only use it
1046          * with the driver that does not provide the full Beacon/Probe Response
1047          * frame. Use Beacon frame pointer to avoid indicating that this should
1048          * override the IEs pointer should we have received an earlier
1049          * indication of Probe Response data.
1050          */
1051         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1052         if (!ies)
1053                 return NULL;
1054         ies->len = ielen;
1055         ies->tsf = tsf;
1056         ies->from_beacon = false;
1057         memcpy(ies->data, ie, ielen);
1058
1059         switch (ftype) {
1060         case CFG80211_BSS_FTYPE_BEACON:
1061                 ies->from_beacon = true;
1062                 /* fall through to assign */
1063         case CFG80211_BSS_FTYPE_UNKNOWN:
1064                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1065                 break;
1066         case CFG80211_BSS_FTYPE_PRESP:
1067                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1068                 break;
1069         }
1070         rcu_assign_pointer(tmp.pub.ies, ies);
1071
1072         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1073                 wiphy->max_adj_channel_rssi_comp;
1074         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1075         if (!res)
1076                 return NULL;
1077
1078         if (channel->band == IEEE80211_BAND_60GHZ) {
1079                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1080                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1081                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1082                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1083         } else {
1084                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1085                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1086         }
1087
1088         trace_cfg80211_return_bss(&res->pub);
1089         /* cfg80211_bss_update gives us a referenced result */
1090         return &res->pub;
1091 }
1092 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1093
1094 /* cfg80211_inform_bss_width_frame helper */
1095 struct cfg80211_bss *
1096 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1097                                struct cfg80211_inform_bss *data,
1098                                struct ieee80211_mgmt *mgmt, size_t len,
1099                                gfp_t gfp)
1100
1101 {
1102         struct cfg80211_internal_bss tmp = {}, *res;
1103         struct cfg80211_bss_ies *ies;
1104         struct ieee80211_channel *channel;
1105         bool signal_valid;
1106         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1107                                       u.probe_resp.variable);
1108         int bss_type;
1109
1110         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1111                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1112
1113         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1114
1115         if (WARN_ON(!mgmt))
1116                 return NULL;
1117
1118         if (WARN_ON(!wiphy))
1119                 return NULL;
1120
1121         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1122                     (data->signal < 0 || data->signal > 100)))
1123                 return NULL;
1124
1125         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1126                 return NULL;
1127
1128         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1129                                            ielen, data->chan);
1130         if (!channel)
1131                 return NULL;
1132
1133         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1134         if (!ies)
1135                 return NULL;
1136         ies->len = ielen;
1137         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1138         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1139         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1140
1141         if (ieee80211_is_probe_resp(mgmt->frame_control))
1142                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1143         else
1144                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1145         rcu_assign_pointer(tmp.pub.ies, ies);
1146
1147         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1148         tmp.pub.channel = channel;
1149         tmp.pub.scan_width = data->scan_width;
1150         tmp.pub.signal = data->signal;
1151         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1152         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1153         tmp.ts_boottime = data->boottime_ns;
1154
1155         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1156                 wiphy->max_adj_channel_rssi_comp;
1157         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1158         if (!res)
1159                 return NULL;
1160
1161         if (channel->band == IEEE80211_BAND_60GHZ) {
1162                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1163                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1164                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1165                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1166         } else {
1167                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1168                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1169         }
1170
1171         trace_cfg80211_return_bss(&res->pub);
1172         /* cfg80211_bss_update gives us a referenced result */
1173         return &res->pub;
1174 }
1175 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1176
1177 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1178 {
1179         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1180         struct cfg80211_internal_bss *bss;
1181
1182         if (!pub)
1183                 return;
1184
1185         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1186
1187         spin_lock_bh(&rdev->bss_lock);
1188         bss_ref_get(rdev, bss);
1189         spin_unlock_bh(&rdev->bss_lock);
1190 }
1191 EXPORT_SYMBOL(cfg80211_ref_bss);
1192
1193 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1194 {
1195         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1196         struct cfg80211_internal_bss *bss;
1197
1198         if (!pub)
1199                 return;
1200
1201         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1202
1203         spin_lock_bh(&rdev->bss_lock);
1204         bss_ref_put(rdev, bss);
1205         spin_unlock_bh(&rdev->bss_lock);
1206 }
1207 EXPORT_SYMBOL(cfg80211_put_bss);
1208
1209 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1210 {
1211         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1212         struct cfg80211_internal_bss *bss;
1213
1214         if (WARN_ON(!pub))
1215                 return;
1216
1217         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1218
1219         spin_lock_bh(&rdev->bss_lock);
1220         if (!list_empty(&bss->list)) {
1221                 if (__cfg80211_unlink_bss(rdev, bss))
1222                         rdev->bss_generation++;
1223         }
1224         spin_unlock_bh(&rdev->bss_lock);
1225 }
1226 EXPORT_SYMBOL(cfg80211_unlink_bss);
1227
1228 #ifdef CONFIG_CFG80211_WEXT
1229 static struct cfg80211_registered_device *
1230 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1231 {
1232         struct cfg80211_registered_device *rdev;
1233         struct net_device *dev;
1234
1235         ASSERT_RTNL();
1236
1237         dev = dev_get_by_index(net, ifindex);
1238         if (!dev)
1239                 return ERR_PTR(-ENODEV);
1240         if (dev->ieee80211_ptr)
1241                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1242         else
1243                 rdev = ERR_PTR(-ENODEV);
1244         dev_put(dev);
1245         return rdev;
1246 }
1247
1248 int cfg80211_wext_siwscan(struct net_device *dev,
1249                           struct iw_request_info *info,
1250                           union iwreq_data *wrqu, char *extra)
1251 {
1252         struct cfg80211_registered_device *rdev;
1253         struct wiphy *wiphy;
1254         struct iw_scan_req *wreq = NULL;
1255         struct cfg80211_scan_request *creq = NULL;
1256         int i, err, n_channels = 0;
1257         enum ieee80211_band band;
1258
1259         if (!netif_running(dev))
1260                 return -ENETDOWN;
1261
1262         if (wrqu->data.length == sizeof(struct iw_scan_req))
1263                 wreq = (struct iw_scan_req *)extra;
1264
1265         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1266
1267         if (IS_ERR(rdev))
1268                 return PTR_ERR(rdev);
1269
1270         if (rdev->scan_req || rdev->scan_msg) {
1271                 err = -EBUSY;
1272                 goto out;
1273         }
1274
1275         wiphy = &rdev->wiphy;
1276
1277         /* Determine number of channels, needed to allocate creq */
1278         if (wreq && wreq->num_channels)
1279                 n_channels = wreq->num_channels;
1280         else
1281                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1282
1283         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1284                        n_channels * sizeof(void *),
1285                        GFP_ATOMIC);
1286         if (!creq) {
1287                 err = -ENOMEM;
1288                 goto out;
1289         }
1290
1291         creq->wiphy = wiphy;
1292         creq->wdev = dev->ieee80211_ptr;
1293         /* SSIDs come after channels */
1294         creq->ssids = (void *)&creq->channels[n_channels];
1295         creq->n_channels = n_channels;
1296         creq->n_ssids = 1;
1297         creq->scan_start = jiffies;
1298
1299         /* translate "Scan on frequencies" request */
1300         i = 0;
1301         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1302                 int j;
1303
1304                 if (!wiphy->bands[band])
1305                         continue;
1306
1307                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1308                         /* ignore disabled channels */
1309                         if (wiphy->bands[band]->channels[j].flags &
1310                                                 IEEE80211_CHAN_DISABLED)
1311                                 continue;
1312
1313                         /* If we have a wireless request structure and the
1314                          * wireless request specifies frequencies, then search
1315                          * for the matching hardware channel.
1316                          */
1317                         if (wreq && wreq->num_channels) {
1318                                 int k;
1319                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1320                                 for (k = 0; k < wreq->num_channels; k++) {
1321                                         struct iw_freq *freq =
1322                                                 &wreq->channel_list[k];
1323                                         int wext_freq =
1324                                                 cfg80211_wext_freq(freq);
1325
1326                                         if (wext_freq == wiphy_freq)
1327                                                 goto wext_freq_found;
1328                                 }
1329                                 goto wext_freq_not_found;
1330                         }
1331
1332                 wext_freq_found:
1333                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1334                         i++;
1335                 wext_freq_not_found: ;
1336                 }
1337         }
1338         /* No channels found? */
1339         if (!i) {
1340                 err = -EINVAL;
1341                 goto out;
1342         }
1343
1344         /* Set real number of channels specified in creq->channels[] */
1345         creq->n_channels = i;
1346
1347         /* translate "Scan for SSID" request */
1348         if (wreq) {
1349                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1350                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1351                                 err = -EINVAL;
1352                                 goto out;
1353                         }
1354                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1355                         creq->ssids[0].ssid_len = wreq->essid_len;
1356                 }
1357                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1358                         creq->n_ssids = 0;
1359         }
1360
1361         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1362                 if (wiphy->bands[i])
1363                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1364
1365         rdev->scan_req = creq;
1366         err = rdev_scan(rdev, creq);
1367         if (err) {
1368                 rdev->scan_req = NULL;
1369                 /* creq will be freed below */
1370         } else {
1371                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1372                 /* creq now owned by driver */
1373                 creq = NULL;
1374                 dev_hold(dev);
1375         }
1376  out:
1377         kfree(creq);
1378         return err;
1379 }
1380 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1381
1382 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1383                                     const struct cfg80211_bss_ies *ies,
1384                                     char *current_ev, char *end_buf)
1385 {
1386         const u8 *pos, *end, *next;
1387         struct iw_event iwe;
1388
1389         if (!ies)
1390                 return current_ev;
1391
1392         /*
1393          * If needed, fragment the IEs buffer (at IE boundaries) into short
1394          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1395          */
1396         pos = ies->data;
1397         end = pos + ies->len;
1398
1399         while (end - pos > IW_GENERIC_IE_MAX) {
1400                 next = pos + 2 + pos[1];
1401                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1402                         next = next + 2 + next[1];
1403
1404                 memset(&iwe, 0, sizeof(iwe));
1405                 iwe.cmd = IWEVGENIE;
1406                 iwe.u.data.length = next - pos;
1407                 current_ev = iwe_stream_add_point_check(info, current_ev,
1408                                                         end_buf, &iwe,
1409                                                         (void *)pos);
1410                 if (IS_ERR(current_ev))
1411                         return current_ev;
1412                 pos = next;
1413         }
1414
1415         if (end > pos) {
1416                 memset(&iwe, 0, sizeof(iwe));
1417                 iwe.cmd = IWEVGENIE;
1418                 iwe.u.data.length = end - pos;
1419                 current_ev = iwe_stream_add_point_check(info, current_ev,
1420                                                         end_buf, &iwe,
1421                                                         (void *)pos);
1422                 if (IS_ERR(current_ev))
1423                         return current_ev;
1424         }
1425
1426         return current_ev;
1427 }
1428
1429 static char *
1430 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1431               struct cfg80211_internal_bss *bss, char *current_ev,
1432               char *end_buf)
1433 {
1434         const struct cfg80211_bss_ies *ies;
1435         struct iw_event iwe;
1436         const u8 *ie;
1437         u8 buf[50];
1438         u8 *cfg, *p, *tmp;
1439         int rem, i, sig;
1440         bool ismesh = false;
1441
1442         memset(&iwe, 0, sizeof(iwe));
1443         iwe.cmd = SIOCGIWAP;
1444         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1445         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1446         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1447                                                 IW_EV_ADDR_LEN);
1448         if (IS_ERR(current_ev))
1449                 return current_ev;
1450
1451         memset(&iwe, 0, sizeof(iwe));
1452         iwe.cmd = SIOCGIWFREQ;
1453         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1454         iwe.u.freq.e = 0;
1455         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1456                                                 IW_EV_FREQ_LEN);
1457         if (IS_ERR(current_ev))
1458                 return current_ev;
1459
1460         memset(&iwe, 0, sizeof(iwe));
1461         iwe.cmd = SIOCGIWFREQ;
1462         iwe.u.freq.m = bss->pub.channel->center_freq;
1463         iwe.u.freq.e = 6;
1464         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1465                                                 IW_EV_FREQ_LEN);
1466         if (IS_ERR(current_ev))
1467                 return current_ev;
1468
1469         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1470                 memset(&iwe, 0, sizeof(iwe));
1471                 iwe.cmd = IWEVQUAL;
1472                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1473                                      IW_QUAL_NOISE_INVALID |
1474                                      IW_QUAL_QUAL_UPDATED;
1475                 switch (wiphy->signal_type) {
1476                 case CFG80211_SIGNAL_TYPE_MBM:
1477                         sig = bss->pub.signal / 100;
1478                         iwe.u.qual.level = sig;
1479                         iwe.u.qual.updated |= IW_QUAL_DBM;
1480                         if (sig < -110)         /* rather bad */
1481                                 sig = -110;
1482                         else if (sig > -40)     /* perfect */
1483                                 sig = -40;
1484                         /* will give a range of 0 .. 70 */
1485                         iwe.u.qual.qual = sig + 110;
1486                         break;
1487                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1488                         iwe.u.qual.level = bss->pub.signal;
1489                         /* will give range 0 .. 100 */
1490                         iwe.u.qual.qual = bss->pub.signal;
1491                         break;
1492                 default:
1493                         /* not reached */
1494                         break;
1495                 }
1496                 current_ev = iwe_stream_add_event_check(info, current_ev,
1497                                                         end_buf, &iwe,
1498                                                         IW_EV_QUAL_LEN);
1499                 if (IS_ERR(current_ev))
1500                         return current_ev;
1501         }
1502
1503         memset(&iwe, 0, sizeof(iwe));
1504         iwe.cmd = SIOCGIWENCODE;
1505         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1506                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1507         else
1508                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1509         iwe.u.data.length = 0;
1510         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1511                                                 &iwe, "");
1512         if (IS_ERR(current_ev))
1513                 return current_ev;
1514
1515         rcu_read_lock();
1516         ies = rcu_dereference(bss->pub.ies);
1517         rem = ies->len;
1518         ie = ies->data;
1519
1520         while (rem >= 2) {
1521                 /* invalid data */
1522                 if (ie[1] > rem - 2)
1523                         break;
1524
1525                 switch (ie[0]) {
1526                 case WLAN_EID_SSID:
1527                         memset(&iwe, 0, sizeof(iwe));
1528                         iwe.cmd = SIOCGIWESSID;
1529                         iwe.u.data.length = ie[1];
1530                         iwe.u.data.flags = 1;
1531                         current_ev = iwe_stream_add_point_check(info,
1532                                                                 current_ev,
1533                                                                 end_buf, &iwe,
1534                                                                 (u8 *)ie + 2);
1535                         if (IS_ERR(current_ev))
1536                                 goto unlock;
1537                         break;
1538                 case WLAN_EID_MESH_ID:
1539                         memset(&iwe, 0, sizeof(iwe));
1540                         iwe.cmd = SIOCGIWESSID;
1541                         iwe.u.data.length = ie[1];
1542                         iwe.u.data.flags = 1;
1543                         current_ev = iwe_stream_add_point_check(info,
1544                                                                 current_ev,
1545                                                                 end_buf, &iwe,
1546                                                                 (u8 *)ie + 2);
1547                         if (IS_ERR(current_ev))
1548                                 goto unlock;
1549                         break;
1550                 case WLAN_EID_MESH_CONFIG:
1551                         ismesh = true;
1552                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1553                                 break;
1554                         cfg = (u8 *)ie + 2;
1555                         memset(&iwe, 0, sizeof(iwe));
1556                         iwe.cmd = IWEVCUSTOM;
1557                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1558                                 "0x%02X", cfg[0]);
1559                         iwe.u.data.length = strlen(buf);
1560                         current_ev = iwe_stream_add_point_check(info,
1561                                                                 current_ev,
1562                                                                 end_buf,
1563                                                                 &iwe, buf);
1564                         if (IS_ERR(current_ev))
1565                                 goto unlock;
1566                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1567                                 cfg[1]);
1568                         iwe.u.data.length = strlen(buf);
1569                         current_ev = iwe_stream_add_point_check(info,
1570                                                                 current_ev,
1571                                                                 end_buf,
1572                                                                 &iwe, buf);
1573                         if (IS_ERR(current_ev))
1574                                 goto unlock;
1575                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1576                                 cfg[2]);
1577                         iwe.u.data.length = strlen(buf);
1578                         current_ev = iwe_stream_add_point_check(info,
1579                                                                 current_ev,
1580                                                                 end_buf,
1581                                                                 &iwe, buf);
1582                         if (IS_ERR(current_ev))
1583                                 goto unlock;
1584                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1585                         iwe.u.data.length = strlen(buf);
1586                         current_ev = iwe_stream_add_point_check(info,
1587                                                                 current_ev,
1588                                                                 end_buf,
1589                                                                 &iwe, buf);
1590                         if (IS_ERR(current_ev))
1591                                 goto unlock;
1592                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1593                         iwe.u.data.length = strlen(buf);
1594                         current_ev = iwe_stream_add_point_check(info,
1595                                                                 current_ev,
1596                                                                 end_buf,
1597                                                                 &iwe, buf);
1598                         if (IS_ERR(current_ev))
1599                                 goto unlock;
1600                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1601                         iwe.u.data.length = strlen(buf);
1602                         current_ev = iwe_stream_add_point_check(info,
1603                                                                 current_ev,
1604                                                                 end_buf,
1605                                                                 &iwe, buf);
1606                         if (IS_ERR(current_ev))
1607                                 goto unlock;
1608                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1609                         iwe.u.data.length = strlen(buf);
1610                         current_ev = iwe_stream_add_point_check(info,
1611                                                                 current_ev,
1612                                                                 end_buf,
1613                                                                 &iwe, buf);
1614                         if (IS_ERR(current_ev))
1615                                 goto unlock;
1616                         break;
1617                 case WLAN_EID_SUPP_RATES:
1618                 case WLAN_EID_EXT_SUPP_RATES:
1619                         /* display all supported rates in readable format */
1620                         p = current_ev + iwe_stream_lcp_len(info);
1621
1622                         memset(&iwe, 0, sizeof(iwe));
1623                         iwe.cmd = SIOCGIWRATE;
1624                         /* Those two flags are ignored... */
1625                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1626
1627                         for (i = 0; i < ie[1]; i++) {
1628                                 iwe.u.bitrate.value =
1629                                         ((ie[i + 2] & 0x7f) * 500000);
1630                                 tmp = p;
1631                                 p = iwe_stream_add_value(info, current_ev, p,
1632                                                          end_buf, &iwe,
1633                                                          IW_EV_PARAM_LEN);
1634                                 if (p == tmp) {
1635                                         current_ev = ERR_PTR(-E2BIG);
1636                                         goto unlock;
1637                                 }
1638                         }
1639                         current_ev = p;
1640                         break;
1641                 }
1642                 rem -= ie[1] + 2;
1643                 ie += ie[1] + 2;
1644         }
1645
1646         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1647             ismesh) {
1648                 memset(&iwe, 0, sizeof(iwe));
1649                 iwe.cmd = SIOCGIWMODE;
1650                 if (ismesh)
1651                         iwe.u.mode = IW_MODE_MESH;
1652                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1653                         iwe.u.mode = IW_MODE_MASTER;
1654                 else
1655                         iwe.u.mode = IW_MODE_ADHOC;
1656                 current_ev = iwe_stream_add_event_check(info, current_ev,
1657                                                         end_buf, &iwe,
1658                                                         IW_EV_UINT_LEN);
1659                 if (IS_ERR(current_ev))
1660                         goto unlock;
1661         }
1662
1663         memset(&iwe, 0, sizeof(iwe));
1664         iwe.cmd = IWEVCUSTOM;
1665         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1666         iwe.u.data.length = strlen(buf);
1667         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1668                                                 &iwe, buf);
1669         if (IS_ERR(current_ev))
1670                 goto unlock;
1671         memset(&iwe, 0, sizeof(iwe));
1672         iwe.cmd = IWEVCUSTOM;
1673         sprintf(buf, " Last beacon: %ums ago",
1674                 elapsed_jiffies_msecs(bss->ts));
1675         iwe.u.data.length = strlen(buf);
1676         current_ev = iwe_stream_add_point_check(info, current_ev,
1677                                                 end_buf, &iwe, buf);
1678         if (IS_ERR(current_ev))
1679                 goto unlock;
1680
1681         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1682
1683  unlock:
1684         rcu_read_unlock();
1685         return current_ev;
1686 }
1687
1688
1689 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1690                                   struct iw_request_info *info,
1691                                   char *buf, size_t len)
1692 {
1693         char *current_ev = buf;
1694         char *end_buf = buf + len;
1695         struct cfg80211_internal_bss *bss;
1696         int err = 0;
1697
1698         spin_lock_bh(&rdev->bss_lock);
1699         cfg80211_bss_expire(rdev);
1700
1701         list_for_each_entry(bss, &rdev->bss_list, list) {
1702                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1703                         err = -E2BIG;
1704                         break;
1705                 }
1706                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1707                                            current_ev, end_buf);
1708                 if (IS_ERR(current_ev)) {
1709                         err = PTR_ERR(current_ev);
1710                         break;
1711                 }
1712         }
1713         spin_unlock_bh(&rdev->bss_lock);
1714
1715         if (err)
1716                 return err;
1717         return current_ev - buf;
1718 }
1719
1720
1721 int cfg80211_wext_giwscan(struct net_device *dev,
1722                           struct iw_request_info *info,
1723                           struct iw_point *data, char *extra)
1724 {
1725         struct cfg80211_registered_device *rdev;
1726         int res;
1727
1728         if (!netif_running(dev))
1729                 return -ENETDOWN;
1730
1731         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1732
1733         if (IS_ERR(rdev))
1734                 return PTR_ERR(rdev);
1735
1736         if (rdev->scan_req || rdev->scan_msg)
1737                 return -EAGAIN;
1738
1739         res = ieee80211_scan_results(rdev, info, extra, data->length);
1740         data->length = 0;
1741         if (res >= 0) {
1742                 data->length = res;
1743                 res = 0;
1744         }
1745
1746         return res;
1747 }
1748 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1749 #endif