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