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    (30 * 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, int 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         if (WARN_ON(oui_type > 0xff))
 375                 return NULL;
 376
 377         while (pos < end) {
 378                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 379                                        end - pos);
 380                 if (!pos)
 381                         return NULL;
 382
 383                 ie = (struct ieee80211_vendor_ie *)pos;
 384
 385                 /* make sure we can access ie->len */
 386                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 387
 388                 if (ie->len < sizeof(*ie))
 389                         goto cont;
 390
 391                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 392                 if (ie_oui == oui &&
 393                     (oui_type < 0 || ie->oui_type == oui_type))
 394                         return pos;
 395 cont:
 396                 pos += 2 + ie->len;
 397         }
 398         return NULL;
 399 }
 400 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 401
 402 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 403                    const u8 *ssid, size_t ssid_len)
 404 {
 405         const struct cfg80211_bss_ies *ies;
 406         const u8 *ssidie;
 407
 408         if (bssid && !ether_addr_equal(a->bssid, bssid))
 409                 return false;
 410
 411         if (!ssid)
 412                 return true;
 413
 414         ies = rcu_access_pointer(a->ies);
 415         if (!ies)
 416                 return false;
 417         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 418         if (!ssidie)
 419                 return false;
 420         if (ssidie[1] != ssid_len)
 421                 return false;
 422         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 423 }
 424
 425 /**
 426  * enum bss_compare_mode - BSS compare mode
 427  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 428  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 429  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 430  */
 431 enum bss_compare_mode {
 432         BSS_CMP_REGULAR,
 433         BSS_CMP_HIDE_ZLEN,
 434         BSS_CMP_HIDE_NUL,
 435 };
 436
 437 static int cmp_bss(struct cfg80211_bss *a,
 438                    struct cfg80211_bss *b,
 439                    enum bss_compare_mode mode)
 440 {
 441         const struct cfg80211_bss_ies *a_ies, *b_ies;
 442         const u8 *ie1 = NULL;
 443         const u8 *ie2 = NULL;
 444         int i, r;
 445
 446         if (a->channel != b->channel)
 447                 return b->channel->center_freq - a->channel->center_freq;
 448
 449         a_ies = rcu_access_pointer(a->ies);
 450         if (!a_ies)
 451                 return -1;
 452         b_ies = rcu_access_pointer(b->ies);
 453         if (!b_ies)
 454                 return 1;
 455
 456         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 457                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 458                                        a_ies->data, a_ies->len);
 459         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 460                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 461                                        b_ies->data, b_ies->len);
 462         if (ie1 && ie2) {
 463                 int mesh_id_cmp;
 464
 465                 if (ie1[1] == ie2[1])
 466                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 467                 else
 468                         mesh_id_cmp = ie2[1] - ie1[1];
 469
 470                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 471                                        a_ies->data, a_ies->len);
 472                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 473                                        b_ies->data, b_ies->len);
 474                 if (ie1 && ie2) {
 475                         if (mesh_id_cmp)
 476                                 return mesh_id_cmp;
 477                         if (ie1[1] != ie2[1])
 478                                 return ie2[1] - ie1[1];
 479                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 480                 }
 481         }
 482
 483         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 484         if (r)
 485                 return r;
 486
 487         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 488         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 489
 490         if (!ie1 && !ie2)
 491                 return 0;
 492
 493         /*
 494          * Note that with "hide_ssid", the function returns a match if
 495          * the already-present BSS ("b") is a hidden SSID beacon for
 496          * the new BSS ("a").
 497          */
 498
 499         /* sort missing IE before (left of) present IE */
 500         if (!ie1)
 501                 return -1;
 502         if (!ie2)
 503                 return 1;
 504
 505         switch (mode) {
 506         case BSS_CMP_HIDE_ZLEN:
 507                 /*
 508                  * In ZLEN mode we assume the BSS entry we're
 509                  * looking for has a zero-length SSID. So if
 510                  * the one we're looking at right now has that,
 511                  * return 0. Otherwise, return the difference
 512                  * in length, but since we're looking for the
 513                  * 0-length it's really equivalent to returning
 514                  * the length of the one we're looking at.
 515                  *
 516                  * No content comparison is needed as we assume
 517                  * the content length is zero.
 518                  */
 519                 return ie2[1];
 520         case BSS_CMP_REGULAR:
 521         default:
 522                 /* sort by length first, then by contents */
 523                 if (ie1[1] != ie2[1])
 524                         return ie2[1] - ie1[1];
 525                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 526         case BSS_CMP_HIDE_NUL:
 527                 if (ie1[1] != ie2[1])
 528                         return ie2[1] - ie1[1];
 529                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 530                 for (i = 0; i < ie2[1]; i++)
 531                         if (ie2[i + 2])
 532                                 return -1;
 533                 return 0;
 534         }
 535 }
 536
 537 static bool cfg80211_bss_type_match(u16 capability,
 538                                     enum nl80211_band band,
 539                                     enum ieee80211_bss_type bss_type)
 540 {
 541         bool ret = true;
 542         u16 mask, val;
 543
 544         if (bss_type == IEEE80211_BSS_TYPE_ANY)
 545                 return ret;
 546
 547         if (band == NL80211_BAND_60GHZ) {
 548                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
 549                 switch (bss_type) {
 550                 case IEEE80211_BSS_TYPE_ESS:
 551                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
 552                         break;
 553                 case IEEE80211_BSS_TYPE_PBSS:
 554                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
 555                         break;
 556                 case IEEE80211_BSS_TYPE_IBSS:
 557                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
 558                         break;
 559                 default:
 560                         return false;
 561                 }
 562         } else {
 563                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
 564                 switch (bss_type) {
 565                 case IEEE80211_BSS_TYPE_ESS:
 566                         val = WLAN_CAPABILITY_ESS;
 567                         break;
 568                 case IEEE80211_BSS_TYPE_IBSS:
 569                         val = WLAN_CAPABILITY_IBSS;
 570                         break;
 571                 case IEEE80211_BSS_TYPE_MBSS:
 572                         val = 0;
 573                         break;
 574                 default:
 575                         return false;
 576                 }
 577         }
 578
 579         ret = ((capability & mask) == val);
 580         return ret;
 581 }
 582
 583 /* Returned bss is reference counted and must be cleaned up appropriately. */
 584 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 585                                       struct ieee80211_channel *channel,
 586                                       const u8 *bssid,
 587                                       const u8 *ssid, size_t ssid_len,
 588                                       enum ieee80211_bss_type bss_type,
 589                                       enum ieee80211_privacy privacy)
 590 {
 591         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 592         struct cfg80211_internal_bss *bss, *res = NULL;
 593         unsigned long now = jiffies;
 594         int bss_privacy;
 595
 596         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
 597                                privacy);
 598
 599         spin_lock_bh(&rdev->bss_lock);
 600
 601         list_for_each_entry(bss, &rdev->bss_list, list) {
 602                 if (!cfg80211_bss_type_match(bss->pub.capability,
 603                                              bss->pub.channel->band, bss_type))
 604                         continue;
 605
 606                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
 607                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
 608                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
 609                         continue;
 610                 if (channel && bss->pub.channel != channel)
 611                         continue;
 612                 if (!is_valid_ether_addr(bss->pub.bssid))
 613                         continue;
 614                 /* Don't get expired BSS structs */
 615                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 616                     !atomic_read(&bss->hold))
 617                         continue;
 618                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 619                         res = bss;
 620                         bss_ref_get(rdev, res);
 621                         break;
 622                 }
 623         }
 624
 625         spin_unlock_bh(&rdev->bss_lock);
 626         if (!res)
 627                 return NULL;
 628         trace_cfg80211_return_bss(&res->pub);
 629         return &res->pub;
 630 }
 631 EXPORT_SYMBOL(cfg80211_get_bss);
 632
 633 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 634                           struct cfg80211_internal_bss *bss)
 635 {
 636         struct rb_node **p = &rdev->bss_tree.rb_node;
 637         struct rb_node *parent = NULL;
 638         struct cfg80211_internal_bss *tbss;
 639         int cmp;
 640
 641         while (*p) {
 642                 parent = *p;
 643                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 644
 645                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 646
 647                 if (WARN_ON(!cmp)) {
 648                         /* will sort of leak this BSS */
 649                         return;
 650                 }
 651
 652                 if (cmp < 0)
 653                         p = &(*p)->rb_left;
 654                 else
 655                         p = &(*p)->rb_right;
 656         }
 657
 658         rb_link_node(&bss->rbn, parent, p);
 659         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 660 }
 661
 662 static struct cfg80211_internal_bss *
 663 rb_find_bss(struct cfg80211_registered_device *rdev,
 664             struct cfg80211_internal_bss *res,
 665             enum bss_compare_mode mode)
 666 {
 667         struct rb_node *n = rdev->bss_tree.rb_node;
 668         struct cfg80211_internal_bss *bss;
 669         int r;
 670
 671         while (n) {
 672                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 673                 r = cmp_bss(&res->pub, &bss->pub, mode);
 674
 675                 if (r == 0)
 676                         return bss;
 677                 else if (r < 0)
 678                         n = n->rb_left;
 679                 else
 680                         n = n->rb_right;
 681         }
 682
 683         return NULL;
 684 }
 685
 686 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 687                                    struct cfg80211_internal_bss *new)
 688 {
 689         const struct cfg80211_bss_ies *ies;
 690         struct cfg80211_internal_bss *bss;
 691         const u8 *ie;
 692         int i, ssidlen;
 693         u8 fold = 0;
 694
 695         ies = rcu_access_pointer(new->pub.beacon_ies);
 696         if (WARN_ON(!ies))
 697                 return false;
 698
 699         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 700         if (!ie) {
 701                 /* nothing to do */
 702                 return true;
 703         }
 704
 705         ssidlen = ie[1];
 706         for (i = 0; i < ssidlen; i++)
 707                 fold |= ie[2 + i];
 708
 709         if (fold) {
 710                 /* not a hidden SSID */
 711                 return true;
 712         }
 713
 714         /* This is the bad part ... */
 715
 716         list_for_each_entry(bss, &rdev->bss_list, list) {
 717                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 718                         continue;
 719                 if (bss->pub.channel != new->pub.channel)
 720                         continue;
 721                 if (bss->pub.scan_width != new->pub.scan_width)
 722                         continue;
 723                 if (rcu_access_pointer(bss->pub.beacon_ies))
 724                         continue;
 725                 ies = rcu_access_pointer(bss->pub.ies);
 726                 if (!ies)
 727                         continue;
 728                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 729                 if (!ie)
 730                         continue;
 731                 if (ssidlen && ie[1] != ssidlen)
 732                         continue;
 733                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 734                         continue;
 735                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 736                         list_del(&bss->hidden_list);
 737                 /* combine them */
 738                 list_add(&bss->hidden_list, &new->hidden_list);
 739                 bss->pub.hidden_beacon_bss = &new->pub;
 740                 new->refcount += bss->refcount;
 741                 rcu_assign_pointer(bss->pub.beacon_ies,
 742                                    new->pub.beacon_ies);
 743         }
 744
 745         return true;
 746 }
 747
 748 /* Returned bss is reference counted and must be cleaned up appropriately. */
 749 static struct cfg80211_internal_bss *
 750 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 751                     struct cfg80211_internal_bss *tmp,
 752                     bool signal_valid)
 753 {
 754         struct cfg80211_internal_bss *found = NULL;
 755
 756         if (WARN_ON(!tmp->pub.channel))
 757                 return NULL;
 758
 759         tmp->ts = jiffies;
 760
 761         spin_lock_bh(&rdev->bss_lock);
 762
 763         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 764                 spin_unlock_bh(&rdev->bss_lock);
 765                 return NULL;
 766         }
 767
 768         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 769
 770         if (found) {
 771                 /* Update IEs */
 772                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 773                         const struct cfg80211_bss_ies *old;
 774
 775                         old = rcu_access_pointer(found->pub.proberesp_ies);
 776
 777                         rcu_assign_pointer(found->pub.proberesp_ies,
 778                                            tmp->pub.proberesp_ies);
 779                         /* Override possible earlier Beacon frame IEs */
 780                         rcu_assign_pointer(found->pub.ies,
 781                                            tmp->pub.proberesp_ies);
 782                         if (old)
 783                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 784                                           rcu_head);
 785                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 786                         const struct cfg80211_bss_ies *old;
 787                         struct cfg80211_internal_bss *bss;
 788
 789                         if (found->pub.hidden_beacon_bss &&
 790                             !list_empty(&found->hidden_list)) {
 791                                 const struct cfg80211_bss_ies *f;
 792
 793                                 /*
 794                                  * The found BSS struct is one of the probe
 795                                  * response members of a group, but we're
 796                                  * receiving a beacon (beacon_ies in the tmp
 797                                  * bss is used). This can only mean that the
 798                                  * AP changed its beacon from not having an
 799                                  * SSID to showing it, which is confusing so
 800                                  * drop this information.
 801                                  */
 802
 803                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 804                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 805                                           rcu_head);
 806                                 goto drop;
 807                         }
 808
 809                         old = rcu_access_pointer(found->pub.beacon_ies);
 810
 811                         rcu_assign_pointer(found->pub.beacon_ies,
 812                                            tmp->pub.beacon_ies);
 813
 814                         /* Override IEs if they were from a beacon before */
 815                         if (old == rcu_access_pointer(found->pub.ies))
 816                                 rcu_assign_pointer(found->pub.ies,
 817                                                    tmp->pub.beacon_ies);
 818
 819                         /* Assign beacon IEs to all sub entries */
 820                         list_for_each_entry(bss, &found->hidden_list,
 821                                             hidden_list) {
 822                                 const struct cfg80211_bss_ies *ies;
 823
 824                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 825                                 WARN_ON(ies != old);
 826
 827                                 rcu_assign_pointer(bss->pub.beacon_ies,
 828                                                    tmp->pub.beacon_ies);
 829                         }
 830
 831                         if (old)
 832                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 833                                           rcu_head);
 834                 }
 835
 836                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 837                 /*
 838                  * don't update the signal if beacon was heard on
 839                  * adjacent channel.
 840                  */
 841                 if (signal_valid)
 842                         found->pub.signal = tmp->pub.signal;
 843                 found->pub.capability = tmp->pub.capability;
 844                 found->ts = tmp->ts;
 845                 found->ts_boottime = tmp->ts_boottime;
 846         } else {
 847                 struct cfg80211_internal_bss *new;
 848                 struct cfg80211_internal_bss *hidden;
 849                 struct cfg80211_bss_ies *ies;
 850
 851                 /*
 852                  * create a copy -- the "res" variable that is passed in
 853                  * is allocated on the stack since it's not needed in the
 854                  * more common case of an update
 855                  */
 856                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 857                               GFP_ATOMIC);
 858                 if (!new) {
 859                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 860                         if (ies)
 861                                 kfree_rcu(ies, rcu_head);
 862                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 863                         if (ies)
 864                                 kfree_rcu(ies, rcu_head);
 865                         goto drop;
 866                 }
 867                 memcpy(new, tmp, sizeof(*new));
 868                 new->refcount = 1;
 869                 INIT_LIST_HEAD(&new->hidden_list);
 870
 871                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 872                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 873                         if (!hidden)
 874                                 hidden = rb_find_bss(rdev, tmp,
 875                                                      BSS_CMP_HIDE_NUL);
 876                         if (hidden) {
 877                                 new->pub.hidden_beacon_bss = &hidden->pub;
 878                                 list_add(&new->hidden_list,
 879                                          &hidden->hidden_list);
 880                                 hidden->refcount++;
 881                                 rcu_assign_pointer(new->pub.beacon_ies,
 882                                                    hidden->pub.beacon_ies);
 883                         }
 884                 } else {
 885                         /*
 886                          * Ok so we found a beacon, and don't have an entry. If
 887                          * it's a beacon with hidden SSID, we might be in for an
 888                          * expensive search for any probe responses that should
 889                          * be grouped with this beacon for updates ...
 890                          */
 891                         if (!cfg80211_combine_bsses(rdev, new)) {
 892                                 kfree(new);
 893                                 goto drop;
 894                         }
 895                 }
 896
 897                 list_add_tail(&new->list, &rdev->bss_list);
 898                 rb_insert_bss(rdev, new);
 899                 found = new;
 900         }
 901
 902         rdev->bss_generation++;
 903         bss_ref_get(rdev, found);
 904         spin_unlock_bh(&rdev->bss_lock);
 905
 906         return found;
 907  drop:
 908         spin_unlock_bh(&rdev->bss_lock);
 909         return NULL;
 910 }
 911
 912 static struct ieee80211_channel *
 913 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 914                          struct ieee80211_channel *channel)
 915 {
 916         const u8 *tmp;
 917         u32 freq;
 918         int channel_number = -1;
 919
 920         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 921         if (tmp && tmp[1] == 1) {
 922                 channel_number = tmp[2];
 923         } else {
 924                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 925                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 926                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 927
 928                         channel_number = htop->primary_chan;
 929                 }
 930         }
 931
 932         if (channel_number < 0)
 933                 return channel;
 934
 935         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 936         channel = ieee80211_get_channel(wiphy, freq);
 937         if (!channel)
 938                 return NULL;
 939         if (channel->flags & IEEE80211_CHAN_DISABLED)
 940                 return NULL;
 941         return channel;
 942 }
 943
 944 /* Returned bss is reference counted and must be cleaned up appropriately. */
 945 struct cfg80211_bss *
 946 cfg80211_inform_bss_data(struct wiphy *wiphy,
 947                          struct cfg80211_inform_bss *data,
 948                          enum cfg80211_bss_frame_type ftype,
 949                          const u8 *bssid, u64 tsf, u16 capability,
 950                          u16 beacon_interval, const u8 *ie, size_t ielen,
 951                          gfp_t gfp)
 952 {
 953         struct cfg80211_bss_ies *ies;
 954         struct ieee80211_channel *channel;
 955         struct cfg80211_internal_bss tmp = {}, *res;
 956         int bss_type;
 957         bool signal_valid;
 958
 959         if (WARN_ON(!wiphy))
 960                 return NULL;
 961
 962         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 963                     (data->signal < 0 || data->signal > 100)))
 964                 return NULL;
 965
 966         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
 967         if (!channel)
 968                 return NULL;
 969
 970         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 971         tmp.pub.channel = channel;
 972         tmp.pub.scan_width = data->scan_width;
 973         tmp.pub.signal = data->signal;
 974         tmp.pub.beacon_interval = beacon_interval;
 975         tmp.pub.capability = capability;
 976         tmp.ts_boottime = data->boottime_ns;
 977
 978         /*
 979          * If we do not know here whether the IEs are from a Beacon or Probe
 980          * Response frame, we need to pick one of the options and only use it
 981          * with the driver that does not provide the full Beacon/Probe Response
 982          * frame. Use Beacon frame pointer to avoid indicating that this should
 983          * override the IEs pointer should we have received an earlier
 984          * indication of Probe Response data.
 985          */
 986         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 987         if (!ies)
 988                 return NULL;
 989         ies->len = ielen;
 990         ies->tsf = tsf;
 991         ies->from_beacon = false;
 992         memcpy(ies->data, ie, ielen);
 993
 994         switch (ftype) {
 995         case CFG80211_BSS_FTYPE_BEACON:
 996                 ies->from_beacon = true;
 997                 /* fall through to assign */
 998         case CFG80211_BSS_FTYPE_UNKNOWN:
 999                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1000                 break;
1001         case CFG80211_BSS_FTYPE_PRESP:
1002                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1003                 break;
1004         }
1005         rcu_assign_pointer(tmp.pub.ies, ies);
1006
1007         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1008                 wiphy->max_adj_channel_rssi_comp;
1009         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1010         if (!res)
1011                 return NULL;
1012
1013         if (channel->band == NL80211_BAND_60GHZ) {
1014                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1015                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1016                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1017                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1018         } else {
1019                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1020                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1021         }
1022
1023         trace_cfg80211_return_bss(&res->pub);
1024         /* cfg80211_bss_update gives us a referenced result */
1025         return &res->pub;
1026 }
1027 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1028
1029 /* cfg80211_inform_bss_width_frame helper */
1030 struct cfg80211_bss *
1031 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1032                                struct cfg80211_inform_bss *data,
1033                                struct ieee80211_mgmt *mgmt, size_t len,
1034                                gfp_t gfp)
1035
1036 {
1037         struct cfg80211_internal_bss tmp = {}, *res;
1038         struct cfg80211_bss_ies *ies;
1039         struct ieee80211_channel *channel;
1040         bool signal_valid;
1041         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1042                                       u.probe_resp.variable);
1043         int bss_type;
1044
1045         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1046                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1047
1048         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1049
1050         if (WARN_ON(!mgmt))
1051                 return NULL;
1052
1053         if (WARN_ON(!wiphy))
1054                 return NULL;
1055
1056         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1057                     (data->signal < 0 || data->signal > 100)))
1058                 return NULL;
1059
1060         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1061                 return NULL;
1062
1063         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1064                                            ielen, data->chan);
1065         if (!channel)
1066                 return NULL;
1067
1068         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1069         if (!ies)
1070                 return NULL;
1071         ies->len = ielen;
1072         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1073         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1074         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1075
1076         if (ieee80211_is_probe_resp(mgmt->frame_control))
1077                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1078         else
1079                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1080         rcu_assign_pointer(tmp.pub.ies, ies);
1081
1082         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1083         tmp.pub.channel = channel;
1084         tmp.pub.scan_width = data->scan_width;
1085         tmp.pub.signal = data->signal;
1086         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1087         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1088         tmp.ts_boottime = data->boottime_ns;
1089
1090         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1091                 wiphy->max_adj_channel_rssi_comp;
1092         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1093         if (!res)
1094                 return NULL;
1095
1096         if (channel->band == NL80211_BAND_60GHZ) {
1097                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1098                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1099                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1100                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1101         } else {
1102                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1103                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1104         }
1105
1106         trace_cfg80211_return_bss(&res->pub);
1107         /* cfg80211_bss_update gives us a referenced result */
1108         return &res->pub;
1109 }
1110 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1111
1112 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1113 {
1114         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1115         struct cfg80211_internal_bss *bss;
1116
1117         if (!pub)
1118                 return;
1119
1120         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1121
1122         spin_lock_bh(&rdev->bss_lock);
1123         bss_ref_get(rdev, bss);
1124         spin_unlock_bh(&rdev->bss_lock);
1125 }
1126 EXPORT_SYMBOL(cfg80211_ref_bss);
1127
1128 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1129 {
1130         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1131         struct cfg80211_internal_bss *bss;
1132
1133         if (!pub)
1134                 return;
1135
1136         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1137
1138         spin_lock_bh(&rdev->bss_lock);
1139         bss_ref_put(rdev, bss);
1140         spin_unlock_bh(&rdev->bss_lock);
1141 }
1142 EXPORT_SYMBOL(cfg80211_put_bss);
1143
1144 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1145 {
1146         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1147         struct cfg80211_internal_bss *bss;
1148
1149         if (WARN_ON(!pub))
1150                 return;
1151
1152         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1153
1154         spin_lock_bh(&rdev->bss_lock);
1155         if (!list_empty(&bss->list)) {
1156                 if (__cfg80211_unlink_bss(rdev, bss))
1157                         rdev->bss_generation++;
1158         }
1159         spin_unlock_bh(&rdev->bss_lock);
1160 }
1161 EXPORT_SYMBOL(cfg80211_unlink_bss);
1162
1163 #ifdef CONFIG_CFG80211_WEXT
1164 static struct cfg80211_registered_device *
1165 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1166 {
1167         struct cfg80211_registered_device *rdev;
1168         struct net_device *dev;
1169
1170         ASSERT_RTNL();
1171
1172         dev = dev_get_by_index(net, ifindex);
1173         if (!dev)
1174                 return ERR_PTR(-ENODEV);
1175         if (dev->ieee80211_ptr)
1176                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1177         else
1178                 rdev = ERR_PTR(-ENODEV);
1179         dev_put(dev);
1180         return rdev;
1181 }
1182
1183 int cfg80211_wext_siwscan(struct net_device *dev,
1184                           struct iw_request_info *info,
1185                           union iwreq_data *wrqu, char *extra)
1186 {
1187         struct cfg80211_registered_device *rdev;
1188         struct wiphy *wiphy;
1189         struct iw_scan_req *wreq = NULL;
1190         struct cfg80211_scan_request *creq = NULL;
1191         int i, err, n_channels = 0;
1192         enum nl80211_band band;
1193
1194         if (!netif_running(dev))
1195                 return -ENETDOWN;
1196
1197         if (wrqu->data.length == sizeof(struct iw_scan_req))
1198                 wreq = (struct iw_scan_req *)extra;
1199
1200         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1201
1202         if (IS_ERR(rdev))
1203                 return PTR_ERR(rdev);
1204
1205         if (rdev->scan_req || rdev->scan_msg) {
1206                 err = -EBUSY;
1207                 goto out;
1208         }
1209
1210         wiphy = &rdev->wiphy;
1211
1212         /* Determine number of channels, needed to allocate creq */
1213         if (wreq && wreq->num_channels)
1214                 n_channels = wreq->num_channels;
1215         else
1216                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1217
1218         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1219                        n_channels * sizeof(void *),
1220                        GFP_ATOMIC);
1221         if (!creq) {
1222                 err = -ENOMEM;
1223                 goto out;
1224         }
1225
1226         creq->wiphy = wiphy;
1227         creq->wdev = dev->ieee80211_ptr;
1228         /* SSIDs come after channels */
1229         creq->ssids = (void *)&creq->channels[n_channels];
1230         creq->n_channels = n_channels;
1231         creq->n_ssids = 1;
1232         creq->scan_start = jiffies;
1233
1234         /* translate "Scan on frequencies" request */
1235         i = 0;
1236         for (band = 0; band < NUM_NL80211_BANDS; band++) {
1237                 int j;
1238
1239                 if (!wiphy->bands[band])
1240                         continue;
1241
1242                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1243                         /* ignore disabled channels */
1244                         if (wiphy->bands[band]->channels[j].flags &
1245                                                 IEEE80211_CHAN_DISABLED)
1246                                 continue;
1247
1248                         /* If we have a wireless request structure and the
1249                          * wireless request specifies frequencies, then search
1250                          * for the matching hardware channel.
1251                          */
1252                         if (wreq && wreq->num_channels) {
1253                                 int k;
1254                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1255                                 for (k = 0; k < wreq->num_channels; k++) {
1256                                         struct iw_freq *freq =
1257                                                 &wreq->channel_list[k];
1258                                         int wext_freq =
1259                                                 cfg80211_wext_freq(freq);
1260
1261                                         if (wext_freq == wiphy_freq)
1262                                                 goto wext_freq_found;
1263                                 }
1264                                 goto wext_freq_not_found;
1265                         }
1266
1267                 wext_freq_found:
1268                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1269                         i++;
1270                 wext_freq_not_found: ;
1271                 }
1272         }
1273         /* No channels found? */
1274         if (!i) {
1275                 err = -EINVAL;
1276                 goto out;
1277         }
1278
1279         /* Set real number of channels specified in creq->channels[] */
1280         creq->n_channels = i;
1281
1282         /* translate "Scan for SSID" request */
1283         if (wreq) {
1284                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1285                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1286                                 err = -EINVAL;
1287                                 goto out;
1288                         }
1289                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1290                         creq->ssids[0].ssid_len = wreq->essid_len;
1291                 }
1292                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1293                         creq->n_ssids = 0;
1294         }
1295
1296         for (i = 0; i < NUM_NL80211_BANDS; i++)
1297                 if (wiphy->bands[i])
1298                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1299
1300         eth_broadcast_addr(creq->bssid);
1301
1302         rdev->scan_req = creq;
1303         err = rdev_scan(rdev, creq);
1304         if (err) {
1305                 rdev->scan_req = NULL;
1306                 /* creq will be freed below */
1307         } else {
1308                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1309                 /* creq now owned by driver */
1310                 creq = NULL;
1311                 dev_hold(dev);
1312         }
1313  out:
1314         kfree(creq);
1315         return err;
1316 }
1317 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1318
1319 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1320                                     const struct cfg80211_bss_ies *ies,
1321                                     char *current_ev, char *end_buf)
1322 {
1323         const u8 *pos, *end, *next;
1324         struct iw_event iwe;
1325
1326         if (!ies)
1327                 return current_ev;
1328
1329         /*
1330          * If needed, fragment the IEs buffer (at IE boundaries) into short
1331          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1332          */
1333         pos = ies->data;
1334         end = pos + ies->len;
1335
1336         while (end - pos > IW_GENERIC_IE_MAX) {
1337                 next = pos + 2 + pos[1];
1338                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1339                         next = next + 2 + next[1];
1340
1341                 memset(&iwe, 0, sizeof(iwe));
1342                 iwe.cmd = IWEVGENIE;
1343                 iwe.u.data.length = next - pos;
1344                 current_ev = iwe_stream_add_point_check(info, current_ev,
1345                                                         end_buf, &iwe,
1346                                                         (void *)pos);
1347                 if (IS_ERR(current_ev))
1348                         return current_ev;
1349                 pos = next;
1350         }
1351
1352         if (end > pos) {
1353                 memset(&iwe, 0, sizeof(iwe));
1354                 iwe.cmd = IWEVGENIE;
1355                 iwe.u.data.length = end - pos;
1356                 current_ev = iwe_stream_add_point_check(info, current_ev,
1357                                                         end_buf, &iwe,
1358                                                         (void *)pos);
1359                 if (IS_ERR(current_ev))
1360                         return current_ev;
1361         }
1362
1363         return current_ev;
1364 }
1365
1366 static char *
1367 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1368               struct cfg80211_internal_bss *bss, char *current_ev,
1369               char *end_buf)
1370 {
1371         const struct cfg80211_bss_ies *ies;
1372         struct iw_event iwe;
1373         const u8 *ie;
1374         u8 buf[50];
1375         u8 *cfg, *p, *tmp;
1376         int rem, i, sig;
1377         bool ismesh = false;
1378
1379         memset(&iwe, 0, sizeof(iwe));
1380         iwe.cmd = SIOCGIWAP;
1381         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1382         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1383         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1384                                                 IW_EV_ADDR_LEN);
1385         if (IS_ERR(current_ev))
1386                 return current_ev;
1387
1388         memset(&iwe, 0, sizeof(iwe));
1389         iwe.cmd = SIOCGIWFREQ;
1390         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1391         iwe.u.freq.e = 0;
1392         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1393                                                 IW_EV_FREQ_LEN);
1394         if (IS_ERR(current_ev))
1395                 return current_ev;
1396
1397         memset(&iwe, 0, sizeof(iwe));
1398         iwe.cmd = SIOCGIWFREQ;
1399         iwe.u.freq.m = bss->pub.channel->center_freq;
1400         iwe.u.freq.e = 6;
1401         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1402                                                 IW_EV_FREQ_LEN);
1403         if (IS_ERR(current_ev))
1404                 return current_ev;
1405
1406         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1407                 memset(&iwe, 0, sizeof(iwe));
1408                 iwe.cmd = IWEVQUAL;
1409                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1410                                      IW_QUAL_NOISE_INVALID |
1411                                      IW_QUAL_QUAL_UPDATED;
1412                 switch (wiphy->signal_type) {
1413                 case CFG80211_SIGNAL_TYPE_MBM:
1414                         sig = bss->pub.signal / 100;
1415                         iwe.u.qual.level = sig;
1416                         iwe.u.qual.updated |= IW_QUAL_DBM;
1417                         if (sig < -110)         /* rather bad */
1418                                 sig = -110;
1419                         else if (sig > -40)     /* perfect */
1420                                 sig = -40;
1421                         /* will give a range of 0 .. 70 */
1422                         iwe.u.qual.qual = sig + 110;
1423                         break;
1424                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1425                         iwe.u.qual.level = bss->pub.signal;
1426                         /* will give range 0 .. 100 */
1427                         iwe.u.qual.qual = bss->pub.signal;
1428                         break;
1429                 default:
1430                         /* not reached */
1431                         break;
1432                 }
1433                 current_ev = iwe_stream_add_event_check(info, current_ev,
1434                                                         end_buf, &iwe,
1435                                                         IW_EV_QUAL_LEN);
1436                 if (IS_ERR(current_ev))
1437                         return current_ev;
1438         }
1439
1440         memset(&iwe, 0, sizeof(iwe));
1441         iwe.cmd = SIOCGIWENCODE;
1442         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1443                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1444         else
1445                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1446         iwe.u.data.length = 0;
1447         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1448                                                 &iwe, "");
1449         if (IS_ERR(current_ev))
1450                 return current_ev;
1451
1452         rcu_read_lock();
1453         ies = rcu_dereference(bss->pub.ies);
1454         rem = ies->len;
1455         ie = ies->data;
1456
1457         while (rem >= 2) {
1458                 /* invalid data */
1459                 if (ie[1] > rem - 2)
1460                         break;
1461
1462                 switch (ie[0]) {
1463                 case WLAN_EID_SSID:
1464                         memset(&iwe, 0, sizeof(iwe));
1465                         iwe.cmd = SIOCGIWESSID;
1466                         iwe.u.data.length = ie[1];
1467                         iwe.u.data.flags = 1;
1468                         current_ev = iwe_stream_add_point_check(info,
1469                                                                 current_ev,
1470                                                                 end_buf, &iwe,
1471                                                                 (u8 *)ie + 2);
1472                         if (IS_ERR(current_ev))
1473                                 goto unlock;
1474                         break;
1475                 case WLAN_EID_MESH_ID:
1476                         memset(&iwe, 0, sizeof(iwe));
1477                         iwe.cmd = SIOCGIWESSID;
1478                         iwe.u.data.length = ie[1];
1479                         iwe.u.data.flags = 1;
1480                         current_ev = iwe_stream_add_point_check(info,
1481                                                                 current_ev,
1482                                                                 end_buf, &iwe,
1483                                                                 (u8 *)ie + 2);
1484                         if (IS_ERR(current_ev))
1485                                 goto unlock;
1486                         break;
1487                 case WLAN_EID_MESH_CONFIG:
1488                         ismesh = true;
1489                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1490                                 break;
1491                         cfg = (u8 *)ie + 2;
1492                         memset(&iwe, 0, sizeof(iwe));
1493                         iwe.cmd = IWEVCUSTOM;
1494                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1495                                 "0x%02X", cfg[0]);
1496                         iwe.u.data.length = strlen(buf);
1497                         current_ev = iwe_stream_add_point_check(info,
1498                                                                 current_ev,
1499                                                                 end_buf,
1500                                                                 &iwe, buf);
1501                         if (IS_ERR(current_ev))
1502                                 goto unlock;
1503                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1504                                 cfg[1]);
1505                         iwe.u.data.length = strlen(buf);
1506                         current_ev = iwe_stream_add_point_check(info,
1507                                                                 current_ev,
1508                                                                 end_buf,
1509                                                                 &iwe, buf);
1510                         if (IS_ERR(current_ev))
1511                                 goto unlock;
1512                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1513                                 cfg[2]);
1514                         iwe.u.data.length = strlen(buf);
1515                         current_ev = iwe_stream_add_point_check(info,
1516                                                                 current_ev,
1517                                                                 end_buf,
1518                                                                 &iwe, buf);
1519                         if (IS_ERR(current_ev))
1520                                 goto unlock;
1521                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1522                         iwe.u.data.length = strlen(buf);
1523                         current_ev = iwe_stream_add_point_check(info,
1524                                                                 current_ev,
1525                                                                 end_buf,
1526                                                                 &iwe, buf);
1527                         if (IS_ERR(current_ev))
1528                                 goto unlock;
1529                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1530                         iwe.u.data.length = strlen(buf);
1531                         current_ev = iwe_stream_add_point_check(info,
1532                                                                 current_ev,
1533                                                                 end_buf,
1534                                                                 &iwe, buf);
1535                         if (IS_ERR(current_ev))
1536                                 goto unlock;
1537                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1538                         iwe.u.data.length = strlen(buf);
1539                         current_ev = iwe_stream_add_point_check(info,
1540                                                                 current_ev,
1541                                                                 end_buf,
1542                                                                 &iwe, buf);
1543                         if (IS_ERR(current_ev))
1544                                 goto unlock;
1545                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1546                         iwe.u.data.length = strlen(buf);
1547                         current_ev = iwe_stream_add_point_check(info,
1548                                                                 current_ev,
1549                                                                 end_buf,
1550                                                                 &iwe, buf);
1551                         if (IS_ERR(current_ev))
1552                                 goto unlock;
1553                         break;
1554                 case WLAN_EID_SUPP_RATES:
1555                 case WLAN_EID_EXT_SUPP_RATES:
1556                         /* display all supported rates in readable format */
1557                         p = current_ev + iwe_stream_lcp_len(info);
1558
1559                         memset(&iwe, 0, sizeof(iwe));
1560                         iwe.cmd = SIOCGIWRATE;
1561                         /* Those two flags are ignored... */
1562                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1563
1564                         for (i = 0; i < ie[1]; i++) {
1565                                 iwe.u.bitrate.value =
1566                                         ((ie[i + 2] & 0x7f) * 500000);
1567                                 tmp = p;
1568                                 p = iwe_stream_add_value(info, current_ev, p,
1569                                                          end_buf, &iwe,
1570                                                          IW_EV_PARAM_LEN);
1571                                 if (p == tmp) {
1572                                         current_ev = ERR_PTR(-E2BIG);
1573                                         goto unlock;
1574                                 }
1575                         }
1576                         current_ev = p;
1577                         break;
1578                 }
1579                 rem -= ie[1] + 2;
1580                 ie += ie[1] + 2;
1581         }
1582
1583         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1584             ismesh) {
1585                 memset(&iwe, 0, sizeof(iwe));
1586                 iwe.cmd = SIOCGIWMODE;
1587                 if (ismesh)
1588                         iwe.u.mode = IW_MODE_MESH;
1589                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1590                         iwe.u.mode = IW_MODE_MASTER;
1591                 else
1592                         iwe.u.mode = IW_MODE_ADHOC;
1593                 current_ev = iwe_stream_add_event_check(info, current_ev,
1594                                                         end_buf, &iwe,
1595                                                         IW_EV_UINT_LEN);
1596                 if (IS_ERR(current_ev))
1597                         goto unlock;
1598         }
1599
1600         memset(&iwe, 0, sizeof(iwe));
1601         iwe.cmd = IWEVCUSTOM;
1602         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1603         iwe.u.data.length = strlen(buf);
1604         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1605                                                 &iwe, buf);
1606         if (IS_ERR(current_ev))
1607                 goto unlock;
1608         memset(&iwe, 0, sizeof(iwe));
1609         iwe.cmd = IWEVCUSTOM;
1610         sprintf(buf, " Last beacon: %ums ago",
1611                 elapsed_jiffies_msecs(bss->ts));
1612         iwe.u.data.length = strlen(buf);
1613         current_ev = iwe_stream_add_point_check(info, current_ev,
1614                                                 end_buf, &iwe, buf);
1615         if (IS_ERR(current_ev))
1616                 goto unlock;
1617
1618         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1619
1620  unlock:
1621         rcu_read_unlock();
1622         return current_ev;
1623 }
1624
1625
1626 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1627                                   struct iw_request_info *info,
1628                                   char *buf, size_t len)
1629 {
1630         char *current_ev = buf;
1631         char *end_buf = buf + len;
1632         struct cfg80211_internal_bss *bss;
1633         int err = 0;
1634
1635         spin_lock_bh(&rdev->bss_lock);
1636         cfg80211_bss_expire(rdev);
1637
1638         list_for_each_entry(bss, &rdev->bss_list, list) {
1639                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1640                         err = -E2BIG;
1641                         break;
1642                 }
1643                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1644                                            current_ev, end_buf);
1645                 if (IS_ERR(current_ev)) {
1646                         err = PTR_ERR(current_ev);
1647                         break;
1648                 }
1649         }
1650         spin_unlock_bh(&rdev->bss_lock);
1651
1652         if (err)
1653                 return err;
1654         return current_ev - buf;
1655 }
1656
1657
1658 int cfg80211_wext_giwscan(struct net_device *dev,
1659                           struct iw_request_info *info,
1660                           struct iw_point *data, char *extra)
1661 {
1662         struct cfg80211_registered_device *rdev;
1663         int res;
1664
1665         if (!netif_running(dev))
1666                 return -ENETDOWN;
1667
1668         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1669
1670         if (IS_ERR(rdev))
1671                 return PTR_ERR(rdev);
1672
1673         if (rdev->scan_req || rdev->scan_msg)
1674                 return -EAGAIN;
1675
1676         res = ieee80211_scan_results(rdev, info, extra, data->length);
1677         data->length = 0;
1678         if (res >= 0) {
1679                 data->length = res;
1680                 res = 0;
1681         }
1682
1683         return res;
1684 }
1685 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1686 #endif