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  * Copyright 2016       Intel Deutschland GmbH
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/module.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/wireless.h>
  13 #include <linux/nl80211.h>
  14 #include <linux/etherdevice.h>
  15 #include <net/arp.h>
  16 #include <net/cfg80211.h>
  17 #include <net/cfg80211-wext.h>
  18 #include <net/iw_handler.h>
  19 #include "core.h"
  20 #include "nl80211.h"
  21 #include "wext-compat.h"
  22 #include "rdev-ops.h"
  23
  24 /**
  25  * DOC: BSS tree/list structure
  26  *
  27  * At the top level, the BSS list is kept in both a list in each
  28  * registered device (@bss_list) as well as an RB-tree for faster
  29  * lookup. In the RB-tree, entries can be looked up using their
  30  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
  31  * for other BSSes.
  32  *
  33  * Due to the possibility of hidden SSIDs, there's a second level
  34  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
  35  * The hidden_list connects all BSSes belonging to a single AP
  36  * that has a hidden SSID, and connects beacon and probe response
  37  * entries. For a probe response entry for a hidden SSID, the
  38  * hidden_beacon_bss pointer points to the BSS struct holding the
  39  * beacon's information.
  40  *
  41  * Reference counting is done for all these references except for
  42  * the hidden_list, so that a beacon BSS struct that is otherwise
  43  * not referenced has one reference for being on the bss_list and
  44  * one for each probe response entry that points to it using the
  45  * hidden_beacon_bss pointer. When a BSS struct that has such a
  46  * pointer is get/put, the refcount update is also propagated to
  47  * the referenced struct, this ensure that it cannot get removed
  48  * while somebody is using the probe response version.
  49  *
  50  * Note that the hidden_beacon_bss pointer never changes, due to
  51  * the reference counting. Therefore, no locking is needed for
  52  * it.
  53  *
  54  * Also note that the hidden_beacon_bss pointer is only relevant
  55  * if the driver uses something other than the IEs, e.g. private
  56  * data stored stored in the BSS struct, since the beacon IEs are
  57  * also linked into the probe response struct.
  58  */
  59
  60 /*
  61  * Limit the number of BSS entries stored in mac80211. Each one is
  62  * a bit over 4k at most, so this limits to roughly 4-5M of memory.
  63  * If somebody wants to really attack this though, they'd likely
  64  * use small beacons, and only one type of frame, limiting each of
  65  * the entries to a much smaller size (in order to generate more
  66  * entries in total, so overhead is bigger.)
  67  */
  68 static int bss_entries_limit = 1000;
  69 module_param(bss_entries_limit, int, 0644);
  70 MODULE_PARM_DESC(bss_entries_limit,
  71                  "limit to number of scan BSS entries (per wiphy, default 1000)");
  72
  73 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  74
  75 static void bss_free(struct cfg80211_internal_bss *bss)
  76 {
  77         struct cfg80211_bss_ies *ies;
  78
  79         if (WARN_ON(atomic_read(&bss->hold)))
  80                 return;
  81
  82         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  83         if (ies && !bss->pub.hidden_beacon_bss)
  84                 kfree_rcu(ies, rcu_head);
  85         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  86         if (ies)
  87                 kfree_rcu(ies, rcu_head);
  88
  89         /*
  90          * This happens when the module is removed, it doesn't
  91          * really matter any more save for completeness
  92          */
  93         if (!list_empty(&bss->hidden_list))
  94                 list_del(&bss->hidden_list);
  95
  96         kfree(bss);
  97 }
  98
  99 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
 100                                struct cfg80211_internal_bss *bss)
 101 {
 102         lockdep_assert_held(&rdev->bss_lock);
 103
 104         bss->refcount++;
 105         if (bss->pub.hidden_beacon_bss) {
 106                 bss = container_of(bss->pub.hidden_beacon_bss,
 107                                    struct cfg80211_internal_bss,
 108                                    pub);
 109                 bss->refcount++;
 110         }
 111 }
 112
 113 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
 114                                struct cfg80211_internal_bss *bss)
 115 {
 116         lockdep_assert_held(&rdev->bss_lock);
 117
 118         if (bss->pub.hidden_beacon_bss) {
 119                 struct cfg80211_internal_bss *hbss;
 120                 hbss = container_of(bss->pub.hidden_beacon_bss,
 121                                     struct cfg80211_internal_bss,
 122                                     pub);
 123                 hbss->refcount--;
 124                 if (hbss->refcount == 0)
 125                         bss_free(hbss);
 126         }
 127         bss->refcount--;
 128         if (bss->refcount == 0)
 129                 bss_free(bss);
 130 }
 131
 132 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 133                                   struct cfg80211_internal_bss *bss)
 134 {
 135         lockdep_assert_held(&rdev->bss_lock);
 136
 137         if (!list_empty(&bss->hidden_list)) {
 138                 /*
 139                  * don't remove the beacon entry if it has
 140                  * probe responses associated with it
 141                  */
 142                 if (!bss->pub.hidden_beacon_bss)
 143                         return false;
 144                 /*
 145                  * if it's a probe response entry break its
 146                  * link to the other entries in the group
 147                  */
 148                 list_del_init(&bss->hidden_list);
 149         }
 150
 151         list_del_init(&bss->list);
 152         rb_erase(&bss->rbn, &rdev->bss_tree);
 153         rdev->bss_entries--;
 154         WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
 155                   "rdev bss entries[%d]/list[empty:%d] corruption\n",
 156                   rdev->bss_entries, list_empty(&rdev->bss_list));
 157         bss_ref_put(rdev, bss);
 158         return true;
 159 }
 160
 161 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 162                                   unsigned long expire_time)
 163 {
 164         struct cfg80211_internal_bss *bss, *tmp;
 165         bool expired = false;
 166
 167         lockdep_assert_held(&rdev->bss_lock);
 168
 169         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
 170                 if (atomic_read(&bss->hold))
 171                         continue;
 172                 if (!time_after(expire_time, bss->ts))
 173                         continue;
 174
 175                 if (__cfg80211_unlink_bss(rdev, bss))
 176                         expired = true;
 177         }
 178
 179         if (expired)
 180                 rdev->bss_generation++;
 181 }
 182
 183 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
 184 {
 185         struct cfg80211_internal_bss *bss, *oldest = NULL;
 186         bool ret;
 187
 188         lockdep_assert_held(&rdev->bss_lock);
 189
 190         list_for_each_entry(bss, &rdev->bss_list, list) {
 191                 if (atomic_read(&bss->hold))
 192                         continue;
 193
 194                 if (!list_empty(&bss->hidden_list) &&
 195                     !bss->pub.hidden_beacon_bss)
 196                         continue;
 197
 198                 if (oldest && time_before(oldest->ts, bss->ts))
 199                         continue;
 200                 oldest = bss;
 201         }
 202
 203         if (WARN_ON(!oldest))
 204                 return false;
 205
 206         /*
 207          * The callers make sure to increase rdev->bss_generation if anything
 208          * gets removed (and a new entry added), so there's no need to also do
 209          * it here.
 210          */
 211
 212         ret = __cfg80211_unlink_bss(rdev, oldest);
 213         WARN_ON(!ret);
 214         return ret;
 215 }
 216
 217 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 218                            bool send_message)
 219 {
 220         struct cfg80211_scan_request *request;
 221         struct wireless_dev *wdev;
 222         struct sk_buff *msg;
 223 #ifdef CONFIG_CFG80211_WEXT
 224         union iwreq_data wrqu;
 225 #endif
 226
 227         ASSERT_RTNL();
 228
 229         if (rdev->scan_msg) {
 230                 nl80211_send_scan_result(rdev, rdev->scan_msg);
 231                 rdev->scan_msg = NULL;
 232                 return;
 233         }
 234
 235         request = rdev->scan_req;
 236         if (!request)
 237                 return;
 238
 239         wdev = request->wdev;
 240
 241         /*
 242          * This must be before sending the other events!
 243          * Otherwise, wpa_supplicant gets completely confused with
 244          * wext events.
 245          */
 246         if (wdev->netdev)
 247                 cfg80211_sme_scan_done(wdev->netdev);
 248
 249         if (!request->info.aborted &&
 250             request->flags & NL80211_SCAN_FLAG_FLUSH) {
 251                 /* flush entries from previous scans */
 252                 spin_lock_bh(&rdev->bss_lock);
 253                 __cfg80211_bss_expire(rdev, request->scan_start);
 254                 spin_unlock_bh(&rdev->bss_lock);
 255         }
 256
 257         msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);
 258
 259 #ifdef CONFIG_CFG80211_WEXT
 260         if (wdev->netdev && !request->info.aborted) {
 261                 memset(&wrqu, 0, sizeof(wrqu));
 262
 263                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 264         }
 265 #endif
 266
 267         if (wdev->netdev)
 268                 dev_put(wdev->netdev);
 269
 270         rdev->scan_req = NULL;
 271         kfree(request);
 272
 273         if (!send_message)
 274                 rdev->scan_msg = msg;
 275         else
 276                 nl80211_send_scan_result(rdev, msg);
 277 }
 278
 279 void __cfg80211_scan_done(struct work_struct *wk)
 280 {
 281         struct cfg80211_registered_device *rdev;
 282
 283         rdev = container_of(wk, struct cfg80211_registered_device,
 284                             scan_done_wk);
 285
 286         rtnl_lock();
 287         ___cfg80211_scan_done(rdev, true);
 288         rtnl_unlock();
 289 }
 290
 291 void cfg80211_scan_done(struct cfg80211_scan_request *request,
 292                         struct cfg80211_scan_info *info)
 293 {
 294         trace_cfg80211_scan_done(request, info);
 295         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
 296
 297         request->info = *info;
 298         request->notified = true;
 299         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
 300 }
 301 EXPORT_SYMBOL(cfg80211_scan_done);
 302
 303 void __cfg80211_sched_scan_results(struct work_struct *wk)
 304 {
 305         struct cfg80211_registered_device *rdev;
 306         struct cfg80211_sched_scan_request *request;
 307
 308         rdev = container_of(wk, struct cfg80211_registered_device,
 309                             sched_scan_results_wk);
 310
 311         rtnl_lock();
 312
 313         request = rtnl_dereference(rdev->sched_scan_req);
 314
 315         /* we don't have sched_scan_req anymore if the scan is stopping */
 316         if (request) {
 317                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 318                         /* flush entries from previous scans */
 319                         spin_lock_bh(&rdev->bss_lock);
 320                         __cfg80211_bss_expire(rdev, request->scan_start);
 321                         spin_unlock_bh(&rdev->bss_lock);
 322                         request->scan_start = jiffies;
 323                 }
 324                 nl80211_send_sched_scan_results(rdev, request->dev);
 325         }
 326
 327         rtnl_unlock();
 328 }
 329
 330 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 331 {
 332         trace_cfg80211_sched_scan_results(wiphy);
 333         /* ignore if we're not scanning */
 334
 335         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
 336                 queue_work(cfg80211_wq,
 337                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
 338 }
 339 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 340
 341 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
 342 {
 343         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 344
 345         ASSERT_RTNL();
 346
 347         trace_cfg80211_sched_scan_stopped(wiphy);
 348
 349         __cfg80211_stop_sched_scan(rdev, true);
 350 }
 351 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 352
 353 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 354 {
 355         rtnl_lock();
 356         cfg80211_sched_scan_stopped_rtnl(wiphy);
 357         rtnl_unlock();
 358 }
 359 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 360
 361 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 362                                bool driver_initiated)
 363 {
 364         struct cfg80211_sched_scan_request *sched_scan_req;
 365         struct net_device *dev;
 366
 367         ASSERT_RTNL();
 368
 369         if (!rdev->sched_scan_req)
 370                 return -ENOENT;
 371
 372         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
 373         dev = sched_scan_req->dev;
 374
 375         if (!driver_initiated) {
 376                 int err = rdev_sched_scan_stop(rdev, dev);
 377                 if (err)
 378                         return err;
 379         }
 380
 381         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 382
 383         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
 384         kfree_rcu(sched_scan_req, rcu_head);
 385
 386         return 0;
 387 }
 388
 389 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 390                       unsigned long age_secs)
 391 {
 392         struct cfg80211_internal_bss *bss;
 393         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 394
 395         spin_lock_bh(&rdev->bss_lock);
 396         list_for_each_entry(bss, &rdev->bss_list, list)
 397                 bss->ts -= age_jiffies;
 398         spin_unlock_bh(&rdev->bss_lock);
 399 }
 400
 401 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 402 {
 403         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 404 }
 405
 406 const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
 407                                  const u8 *match, int match_len,
 408                                  int match_offset)
 409 {
 410         /* match_offset can't be smaller than 2, unless match_len is
 411          * zero, in which case match_offset must be zero as well.
 412          */
 413         if (WARN_ON((match_len && match_offset < 2) ||
 414                     (!match_len && match_offset)))
 415                 return NULL;
 416
 417         while (len >= 2 && len >= ies[1] + 2) {
 418                 if ((ies[0] == eid) &&
 419                     (ies[1] + 2 >= match_offset + match_len) &&
 420                     !memcmp(ies + match_offset, match, match_len))
 421                         return ies;
 422
 423                 len -= ies[1] + 2;
 424                 ies += ies[1] + 2;
 425         }
 426
 427         return NULL;
 428 }
 429 EXPORT_SYMBOL(cfg80211_find_ie_match);
 430
 431 const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
 432                                   const u8 *ies, int len)
 433 {
 434         const u8 *ie;
 435         u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
 436         int match_len = (oui_type < 0) ? 3 : sizeof(match);
 437
 438         if (WARN_ON(oui_type > 0xff))
 439                 return NULL;
 440
 441         ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
 442                                     match, match_len, 2);
 443
 444         if (ie && (ie[1] < 4))
 445                 return NULL;
 446
 447         return ie;
 448 }
 449 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 450
 451 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 452                    const u8 *ssid, size_t ssid_len)
 453 {
 454         const struct cfg80211_bss_ies *ies;
 455         const u8 *ssidie;
 456
 457         if (bssid && !ether_addr_equal(a->bssid, bssid))
 458                 return false;
 459
 460         if (!ssid)
 461                 return true;
 462
 463         ies = rcu_access_pointer(a->ies);
 464         if (!ies)
 465                 return false;
 466         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 467         if (!ssidie)
 468                 return false;
 469         if (ssidie[1] != ssid_len)
 470                 return false;
 471         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 472 }
 473
 474 /**
 475  * enum bss_compare_mode - BSS compare mode
 476  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 477  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 478  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 479  */
 480 enum bss_compare_mode {
 481         BSS_CMP_REGULAR,
 482         BSS_CMP_HIDE_ZLEN,
 483         BSS_CMP_HIDE_NUL,
 484 };
 485
 486 static int cmp_bss(struct cfg80211_bss *a,
 487                    struct cfg80211_bss *b,
 488                    enum bss_compare_mode mode)
 489 {
 490         const struct cfg80211_bss_ies *a_ies, *b_ies;
 491         const u8 *ie1 = NULL;
 492         const u8 *ie2 = NULL;
 493         int i, r;
 494
 495         if (a->channel != b->channel)
 496                 return b->channel->center_freq - a->channel->center_freq;
 497
 498         a_ies = rcu_access_pointer(a->ies);
 499         if (!a_ies)
 500                 return -1;
 501         b_ies = rcu_access_pointer(b->ies);
 502         if (!b_ies)
 503                 return 1;
 504
 505         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 506                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 507                                        a_ies->data, a_ies->len);
 508         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 509                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 510                                        b_ies->data, b_ies->len);
 511         if (ie1 && ie2) {
 512                 int mesh_id_cmp;
 513
 514                 if (ie1[1] == ie2[1])
 515                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 516                 else
 517                         mesh_id_cmp = ie2[1] - ie1[1];
 518
 519                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 520                                        a_ies->data, a_ies->len);
 521                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 522                                        b_ies->data, b_ies->len);
 523                 if (ie1 && ie2) {
 524                         if (mesh_id_cmp)
 525                                 return mesh_id_cmp;
 526                         if (ie1[1] != ie2[1])
 527                                 return ie2[1] - ie1[1];
 528                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 529                 }
 530         }
 531
 532         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 533         if (r)
 534                 return r;
 535
 536         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 537         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 538
 539         if (!ie1 && !ie2)
 540                 return 0;
 541
 542         /*
 543          * Note that with "hide_ssid", the function returns a match if
 544          * the already-present BSS ("b") is a hidden SSID beacon for
 545          * the new BSS ("a").
 546          */
 547
 548         /* sort missing IE before (left of) present IE */
 549         if (!ie1)
 550                 return -1;
 551         if (!ie2)
 552                 return 1;
 553
 554         switch (mode) {
 555         case BSS_CMP_HIDE_ZLEN:
 556                 /*
 557                  * In ZLEN mode we assume the BSS entry we're
 558                  * looking for has a zero-length SSID. So if
 559                  * the one we're looking at right now has that,
 560                  * return 0. Otherwise, return the difference
 561                  * in length, but since we're looking for the
 562                  * 0-length it's really equivalent to returning
 563                  * the length of the one we're looking at.
 564                  *
 565                  * No content comparison is needed as we assume
 566                  * the content length is zero.
 567                  */
 568                 return ie2[1];
 569         case BSS_CMP_REGULAR:
 570         default:
 571                 /* sort by length first, then by contents */
 572                 if (ie1[1] != ie2[1])
 573                         return ie2[1] - ie1[1];
 574                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 575         case BSS_CMP_HIDE_NUL:
 576                 if (ie1[1] != ie2[1])
 577                         return ie2[1] - ie1[1];
 578                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 579                 for (i = 0; i < ie2[1]; i++)
 580                         if (ie2[i + 2])
 581                                 return -1;
 582                 return 0;
 583         }
 584 }
 585
 586 static bool cfg80211_bss_type_match(u16 capability,
 587                                     enum nl80211_band band,
 588                                     enum ieee80211_bss_type bss_type)
 589 {
 590         bool ret = true;
 591         u16 mask, val;
 592
 593         if (bss_type == IEEE80211_BSS_TYPE_ANY)
 594                 return ret;
 595
 596         if (band == NL80211_BAND_60GHZ) {
 597                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
 598                 switch (bss_type) {
 599                 case IEEE80211_BSS_TYPE_ESS:
 600                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
 601                         break;
 602                 case IEEE80211_BSS_TYPE_PBSS:
 603                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
 604                         break;
 605                 case IEEE80211_BSS_TYPE_IBSS:
 606                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
 607                         break;
 608                 default:
 609                         return false;
 610                 }
 611         } else {
 612                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
 613                 switch (bss_type) {
 614                 case IEEE80211_BSS_TYPE_ESS:
 615                         val = WLAN_CAPABILITY_ESS;
 616                         break;
 617                 case IEEE80211_BSS_TYPE_IBSS:
 618                         val = WLAN_CAPABILITY_IBSS;
 619                         break;
 620                 case IEEE80211_BSS_TYPE_MBSS:
 621                         val = 0;
 622                         break;
 623                 default:
 624                         return false;
 625                 }
 626         }
 627
 628         ret = ((capability & mask) == val);
 629         return ret;
 630 }
 631
 632 /* Returned bss is reference counted and must be cleaned up appropriately. */
 633 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 634                                       struct ieee80211_channel *channel,
 635                                       const u8 *bssid,
 636                                       const u8 *ssid, size_t ssid_len,
 637                                       enum ieee80211_bss_type bss_type,
 638                                       enum ieee80211_privacy privacy)
 639 {
 640         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 641         struct cfg80211_internal_bss *bss, *res = NULL;
 642         unsigned long now = jiffies;
 643         int bss_privacy;
 644
 645         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
 646                                privacy);
 647
 648         spin_lock_bh(&rdev->bss_lock);
 649
 650         list_for_each_entry(bss, &rdev->bss_list, list) {
 651                 if (!cfg80211_bss_type_match(bss->pub.capability,
 652                                              bss->pub.channel->band, bss_type))
 653                         continue;
 654
 655                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
 656                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
 657                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
 658                         continue;
 659                 if (channel && bss->pub.channel != channel)
 660                         continue;
 661                 if (!is_valid_ether_addr(bss->pub.bssid))
 662                         continue;
 663                 /* Don't get expired BSS structs */
 664                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 665                     !atomic_read(&bss->hold))
 666                         continue;
 667                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 668                         res = bss;
 669                         bss_ref_get(rdev, res);
 670                         break;
 671                 }
 672         }
 673
 674         spin_unlock_bh(&rdev->bss_lock);
 675         if (!res)
 676                 return NULL;
 677         trace_cfg80211_return_bss(&res->pub);
 678         return &res->pub;
 679 }
 680 EXPORT_SYMBOL(cfg80211_get_bss);
 681
 682 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 683                           struct cfg80211_internal_bss *bss)
 684 {
 685         struct rb_node **p = &rdev->bss_tree.rb_node;
 686         struct rb_node *parent = NULL;
 687         struct cfg80211_internal_bss *tbss;
 688         int cmp;
 689
 690         while (*p) {
 691                 parent = *p;
 692                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 693
 694                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 695
 696                 if (WARN_ON(!cmp)) {
 697                         /* will sort of leak this BSS */
 698                         return;
 699                 }
 700
 701                 if (cmp < 0)
 702                         p = &(*p)->rb_left;
 703                 else
 704                         p = &(*p)->rb_right;
 705         }
 706
 707         rb_link_node(&bss->rbn, parent, p);
 708         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 709 }
 710
 711 static struct cfg80211_internal_bss *
 712 rb_find_bss(struct cfg80211_registered_device *rdev,
 713             struct cfg80211_internal_bss *res,
 714             enum bss_compare_mode mode)
 715 {
 716         struct rb_node *n = rdev->bss_tree.rb_node;
 717         struct cfg80211_internal_bss *bss;
 718         int r;
 719
 720         while (n) {
 721                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 722                 r = cmp_bss(&res->pub, &bss->pub, mode);
 723
 724                 if (r == 0)
 725                         return bss;
 726                 else if (r < 0)
 727                         n = n->rb_left;
 728                 else
 729                         n = n->rb_right;
 730         }
 731
 732         return NULL;
 733 }
 734
 735 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 736                                    struct cfg80211_internal_bss *new)
 737 {
 738         const struct cfg80211_bss_ies *ies;
 739         struct cfg80211_internal_bss *bss;
 740         const u8 *ie;
 741         int i, ssidlen;
 742         u8 fold = 0;
 743         u32 n_entries = 0;
 744
 745         ies = rcu_access_pointer(new->pub.beacon_ies);
 746         if (WARN_ON(!ies))
 747                 return false;
 748
 749         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 750         if (!ie) {
 751                 /* nothing to do */
 752                 return true;
 753         }
 754
 755         ssidlen = ie[1];
 756         for (i = 0; i < ssidlen; i++)
 757                 fold |= ie[2 + i];
 758
 759         if (fold) {
 760                 /* not a hidden SSID */
 761                 return true;
 762         }
 763
 764         /* This is the bad part ... */
 765
 766         list_for_each_entry(bss, &rdev->bss_list, list) {
 767                 /*
 768                  * we're iterating all the entries anyway, so take the
 769                  * opportunity to validate the list length accounting
 770                  */
 771                 n_entries++;
 772
 773                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 774                         continue;
 775                 if (bss->pub.channel != new->pub.channel)
 776                         continue;
 777                 if (bss->pub.scan_width != new->pub.scan_width)
 778                         continue;
 779                 if (rcu_access_pointer(bss->pub.beacon_ies))
 780                         continue;
 781                 ies = rcu_access_pointer(bss->pub.ies);
 782                 if (!ies)
 783                         continue;
 784                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 785                 if (!ie)
 786                         continue;
 787                 if (ssidlen && ie[1] != ssidlen)
 788                         continue;
 789                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 790                         continue;
 791                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 792                         list_del(&bss->hidden_list);
 793                 /* combine them */
 794                 list_add(&bss->hidden_list, &new->hidden_list);
 795                 bss->pub.hidden_beacon_bss = &new->pub;
 796                 new->refcount += bss->refcount;
 797                 rcu_assign_pointer(bss->pub.beacon_ies,
 798                                    new->pub.beacon_ies);
 799         }
 800
 801         WARN_ONCE(n_entries != rdev->bss_entries,
 802                   "rdev bss entries[%d]/list[len:%d] corruption\n",
 803                   rdev->bss_entries, n_entries);
 804
 805         return true;
 806 }
 807
 808 /* Returned bss is reference counted and must be cleaned up appropriately. */
 809 static struct cfg80211_internal_bss *
 810 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 811                     struct cfg80211_internal_bss *tmp,
 812                     bool signal_valid)
 813 {
 814         struct cfg80211_internal_bss *found = NULL;
 815
 816         if (WARN_ON(!tmp->pub.channel))
 817                 return NULL;
 818
 819         tmp->ts = jiffies;
 820
 821         spin_lock_bh(&rdev->bss_lock);
 822
 823         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 824                 spin_unlock_bh(&rdev->bss_lock);
 825                 return NULL;
 826         }
 827
 828         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 829
 830         if (found) {
 831                 /* Update IEs */
 832                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 833                         const struct cfg80211_bss_ies *old;
 834
 835                         old = rcu_access_pointer(found->pub.proberesp_ies);
 836
 837                         rcu_assign_pointer(found->pub.proberesp_ies,
 838                                            tmp->pub.proberesp_ies);
 839                         /* Override possible earlier Beacon frame IEs */
 840                         rcu_assign_pointer(found->pub.ies,
 841                                            tmp->pub.proberesp_ies);
 842                         if (old)
 843                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 844                                           rcu_head);
 845                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 846                         const struct cfg80211_bss_ies *old;
 847                         struct cfg80211_internal_bss *bss;
 848
 849                         if (found->pub.hidden_beacon_bss &&
 850                             !list_empty(&found->hidden_list)) {
 851                                 const struct cfg80211_bss_ies *f;
 852
 853                                 /*
 854                                  * The found BSS struct is one of the probe
 855                                  * response members of a group, but we're
 856                                  * receiving a beacon (beacon_ies in the tmp
 857                                  * bss is used). This can only mean that the
 858                                  * AP changed its beacon from not having an
 859                                  * SSID to showing it, which is confusing so
 860                                  * drop this information.
 861                                  */
 862
 863                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 864                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 865                                           rcu_head);
 866                                 goto drop;
 867                         }
 868
 869                         old = rcu_access_pointer(found->pub.beacon_ies);
 870
 871                         rcu_assign_pointer(found->pub.beacon_ies,
 872                                            tmp->pub.beacon_ies);
 873
 874                         /* Override IEs if they were from a beacon before */
 875                         if (old == rcu_access_pointer(found->pub.ies))
 876                                 rcu_assign_pointer(found->pub.ies,
 877                                                    tmp->pub.beacon_ies);
 878
 879                         /* Assign beacon IEs to all sub entries */
 880                         list_for_each_entry(bss, &found->hidden_list,
 881                                             hidden_list) {
 882                                 const struct cfg80211_bss_ies *ies;
 883
 884                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 885                                 WARN_ON(ies != old);
 886
 887                                 rcu_assign_pointer(bss->pub.beacon_ies,
 888                                                    tmp->pub.beacon_ies);
 889                         }
 890
 891                         if (old)
 892                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 893                                           rcu_head);
 894                 }
 895
 896                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 897                 /*
 898                  * don't update the signal if beacon was heard on
 899                  * adjacent channel.
 900                  */
 901                 if (signal_valid)
 902                         found->pub.signal = tmp->pub.signal;
 903                 found->pub.capability = tmp->pub.capability;
 904                 found->ts = tmp->ts;
 905                 found->ts_boottime = tmp->ts_boottime;
 906                 found->parent_tsf = tmp->parent_tsf;
 907                 ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
 908         } else {
 909                 struct cfg80211_internal_bss *new;
 910                 struct cfg80211_internal_bss *hidden;
 911                 struct cfg80211_bss_ies *ies;
 912
 913                 /*
 914                  * create a copy -- the "res" variable that is passed in
 915                  * is allocated on the stack since it's not needed in the
 916                  * more common case of an update
 917                  */
 918                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 919                               GFP_ATOMIC);
 920                 if (!new) {
 921                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 922                         if (ies)
 923                                 kfree_rcu(ies, rcu_head);
 924                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 925                         if (ies)
 926                                 kfree_rcu(ies, rcu_head);
 927                         goto drop;
 928                 }
 929                 memcpy(new, tmp, sizeof(*new));
 930                 new->refcount = 1;
 931                 INIT_LIST_HEAD(&new->hidden_list);
 932
 933                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 934                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 935                         if (!hidden)
 936                                 hidden = rb_find_bss(rdev, tmp,
 937                                                      BSS_CMP_HIDE_NUL);
 938                         if (hidden) {
 939                                 new->pub.hidden_beacon_bss = &hidden->pub;
 940                                 list_add(&new->hidden_list,
 941                                          &hidden->hidden_list);
 942                                 hidden->refcount++;
 943                                 rcu_assign_pointer(new->pub.beacon_ies,
 944                                                    hidden->pub.beacon_ies);
 945                         }
 946                 } else {
 947                         /*
 948                          * Ok so we found a beacon, and don't have an entry. If
 949                          * it's a beacon with hidden SSID, we might be in for an
 950                          * expensive search for any probe responses that should
 951                          * be grouped with this beacon for updates ...
 952                          */
 953                         if (!cfg80211_combine_bsses(rdev, new)) {
 954                                 kfree(new);
 955                                 goto drop;
 956                         }
 957                 }
 958
 959                 if (rdev->bss_entries >= bss_entries_limit &&
 960                     !cfg80211_bss_expire_oldest(rdev)) {
 961                         kfree(new);
 962                         goto drop;
 963                 }
 964
 965                 list_add_tail(&new->list, &rdev->bss_list);
 966                 rdev->bss_entries++;
 967                 rb_insert_bss(rdev, new);
 968                 found = new;
 969         }
 970
 971         rdev->bss_generation++;
 972         bss_ref_get(rdev, found);
 973         spin_unlock_bh(&rdev->bss_lock);
 974
 975         return found;
 976  drop:
 977         spin_unlock_bh(&rdev->bss_lock);
 978         return NULL;
 979 }
 980
 981 static struct ieee80211_channel *
 982 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 983                          struct ieee80211_channel *channel)
 984 {
 985         const u8 *tmp;
 986         u32 freq;
 987         int channel_number = -1;
 988
 989         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 990         if (tmp && tmp[1] == 1) {
 991                 channel_number = tmp[2];
 992         } else {
 993                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 994                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 995                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 996
 997                         channel_number = htop->primary_chan;
 998                 }
 999         }
1000
1001         if (channel_number < 0)
1002                 return channel;
1003
1004         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
1005         channel = ieee80211_get_channel(wiphy, freq);
1006         if (!channel)
1007                 return NULL;
1008         if (channel->flags & IEEE80211_CHAN_DISABLED)
1009                 return NULL;
1010         return channel;
1011 }
1012
1013 /* Returned bss is reference counted and must be cleaned up appropriately. */
1014 struct cfg80211_bss *
1015 cfg80211_inform_bss_data(struct wiphy *wiphy,
1016                          struct cfg80211_inform_bss *data,
1017                          enum cfg80211_bss_frame_type ftype,
1018                          const u8 *bssid, u64 tsf, u16 capability,
1019                          u16 beacon_interval, const u8 *ie, size_t ielen,
1020                          gfp_t gfp)
1021 {
1022         struct cfg80211_bss_ies *ies;
1023         struct ieee80211_channel *channel;
1024         struct cfg80211_internal_bss tmp = {}, *res;
1025         int bss_type;
1026         bool signal_valid;
1027
1028         if (WARN_ON(!wiphy))
1029                 return NULL;
1030
1031         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1032                     (data->signal < 0 || data->signal > 100)))
1033                 return NULL;
1034
1035         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
1036         if (!channel)
1037                 return NULL;
1038
1039         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
1040         tmp.pub.channel = channel;
1041         tmp.pub.scan_width = data->scan_width;
1042         tmp.pub.signal = data->signal;
1043         tmp.pub.beacon_interval = beacon_interval;
1044         tmp.pub.capability = capability;
1045         tmp.ts_boottime = data->boottime_ns;
1046
1047         /*
1048          * If we do not know here whether the IEs are from a Beacon or Probe
1049          * Response frame, we need to pick one of the options and only use it
1050          * with the driver that does not provide the full Beacon/Probe Response
1051          * frame. Use Beacon frame pointer to avoid indicating that this should
1052          * override the IEs pointer should we have received an earlier
1053          * indication of Probe Response data.
1054          */
1055         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1056         if (!ies)
1057                 return NULL;
1058         ies->len = ielen;
1059         ies->tsf = tsf;
1060         ies->from_beacon = false;
1061         memcpy(ies->data, ie, ielen);
1062
1063         switch (ftype) {
1064         case CFG80211_BSS_FTYPE_BEACON:
1065                 ies->from_beacon = true;
1066                 /* fall through to assign */
1067         case CFG80211_BSS_FTYPE_UNKNOWN:
1068                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1069                 break;
1070         case CFG80211_BSS_FTYPE_PRESP:
1071                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1072                 break;
1073         }
1074         rcu_assign_pointer(tmp.pub.ies, ies);
1075
1076         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1077                 wiphy->max_adj_channel_rssi_comp;
1078         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1079         if (!res)
1080                 return NULL;
1081
1082         if (channel->band == NL80211_BAND_60GHZ) {
1083                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1084                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1085                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1086                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1087         } else {
1088                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1089                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1090         }
1091
1092         trace_cfg80211_return_bss(&res->pub);
1093         /* cfg80211_bss_update gives us a referenced result */
1094         return &res->pub;
1095 }
1096 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1097
1098 /* cfg80211_inform_bss_width_frame helper */
1099 struct cfg80211_bss *
1100 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1101                                struct cfg80211_inform_bss *data,
1102                                struct ieee80211_mgmt *mgmt, size_t len,
1103                                gfp_t gfp)
1104
1105 {
1106         struct cfg80211_internal_bss tmp = {}, *res;
1107         struct cfg80211_bss_ies *ies;
1108         struct ieee80211_channel *channel;
1109         bool signal_valid;
1110         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1111                                       u.probe_resp.variable);
1112         int bss_type;
1113
1114         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1115                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1116
1117         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1118
1119         if (WARN_ON(!mgmt))
1120                 return NULL;
1121
1122         if (WARN_ON(!wiphy))
1123                 return NULL;
1124
1125         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1126                     (data->signal < 0 || data->signal > 100)))
1127                 return NULL;
1128
1129         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1130                 return NULL;
1131
1132         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1133                                            ielen, data->chan);
1134         if (!channel)
1135                 return NULL;
1136
1137         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1138         if (!ies)
1139                 return NULL;
1140         ies->len = ielen;
1141         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1142         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1143         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1144
1145         if (ieee80211_is_probe_resp(mgmt->frame_control))
1146                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1147         else
1148                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1149         rcu_assign_pointer(tmp.pub.ies, ies);
1150
1151         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1152         tmp.pub.channel = channel;
1153         tmp.pub.scan_width = data->scan_width;
1154         tmp.pub.signal = data->signal;
1155         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1156         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1157         tmp.ts_boottime = data->boottime_ns;
1158         tmp.parent_tsf = data->parent_tsf;
1159         ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
1160
1161         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1162                 wiphy->max_adj_channel_rssi_comp;
1163         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1164         if (!res)
1165                 return NULL;
1166
1167         if (channel->band == NL80211_BAND_60GHZ) {
1168                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1169                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1170                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1171                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1172         } else {
1173                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1174                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1175         }
1176
1177         trace_cfg80211_return_bss(&res->pub);
1178         /* cfg80211_bss_update gives us a referenced result */
1179         return &res->pub;
1180 }
1181 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1182
1183 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1184 {
1185         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1186         struct cfg80211_internal_bss *bss;
1187
1188         if (!pub)
1189                 return;
1190
1191         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1192
1193         spin_lock_bh(&rdev->bss_lock);
1194         bss_ref_get(rdev, bss);
1195         spin_unlock_bh(&rdev->bss_lock);
1196 }
1197 EXPORT_SYMBOL(cfg80211_ref_bss);
1198
1199 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1200 {
1201         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1202         struct cfg80211_internal_bss *bss;
1203
1204         if (!pub)
1205                 return;
1206
1207         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1208
1209         spin_lock_bh(&rdev->bss_lock);
1210         bss_ref_put(rdev, bss);
1211         spin_unlock_bh(&rdev->bss_lock);
1212 }
1213 EXPORT_SYMBOL(cfg80211_put_bss);
1214
1215 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1216 {
1217         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1218         struct cfg80211_internal_bss *bss;
1219
1220         if (WARN_ON(!pub))
1221                 return;
1222
1223         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1224
1225         spin_lock_bh(&rdev->bss_lock);
1226         if (!list_empty(&bss->list)) {
1227                 if (__cfg80211_unlink_bss(rdev, bss))
1228                         rdev->bss_generation++;
1229         }
1230         spin_unlock_bh(&rdev->bss_lock);
1231 }
1232 EXPORT_SYMBOL(cfg80211_unlink_bss);
1233
1234 #ifdef CONFIG_CFG80211_WEXT
1235 static struct cfg80211_registered_device *
1236 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1237 {
1238         struct cfg80211_registered_device *rdev;
1239         struct net_device *dev;
1240
1241         ASSERT_RTNL();
1242
1243         dev = dev_get_by_index(net, ifindex);
1244         if (!dev)
1245                 return ERR_PTR(-ENODEV);
1246         if (dev->ieee80211_ptr)
1247                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1248         else
1249                 rdev = ERR_PTR(-ENODEV);
1250         dev_put(dev);
1251         return rdev;
1252 }
1253
1254 int cfg80211_wext_siwscan(struct net_device *dev,
1255                           struct iw_request_info *info,
1256                           union iwreq_data *wrqu, char *extra)
1257 {
1258         struct cfg80211_registered_device *rdev;
1259         struct wiphy *wiphy;
1260         struct iw_scan_req *wreq = NULL;
1261         struct cfg80211_scan_request *creq = NULL;
1262         int i, err, n_channels = 0;
1263         enum nl80211_band band;
1264
1265         if (!netif_running(dev))
1266                 return -ENETDOWN;
1267
1268         if (wrqu->data.length == sizeof(struct iw_scan_req))
1269                 wreq = (struct iw_scan_req *)extra;
1270
1271         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1272
1273         if (IS_ERR(rdev))
1274                 return PTR_ERR(rdev);
1275
1276         if (rdev->scan_req || rdev->scan_msg) {
1277                 err = -EBUSY;
1278                 goto out;
1279         }
1280
1281         wiphy = &rdev->wiphy;
1282
1283         /* Determine number of channels, needed to allocate creq */
1284         if (wreq && wreq->num_channels)
1285                 n_channels = wreq->num_channels;
1286         else
1287                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1288
1289         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1290                        n_channels * sizeof(void *),
1291                        GFP_ATOMIC);
1292         if (!creq) {
1293                 err = -ENOMEM;
1294                 goto out;
1295         }
1296
1297         creq->wiphy = wiphy;
1298         creq->wdev = dev->ieee80211_ptr;
1299         /* SSIDs come after channels */
1300         creq->ssids = (void *)&creq->channels[n_channels];
1301         creq->n_channels = n_channels;
1302         creq->n_ssids = 1;
1303         creq->scan_start = jiffies;
1304
1305         /* translate "Scan on frequencies" request */
1306         i = 0;
1307         for (band = 0; band < NUM_NL80211_BANDS; band++) {
1308                 int j;
1309
1310                 if (!wiphy->bands[band])
1311                         continue;
1312
1313                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1314                         /* ignore disabled channels */
1315                         if (wiphy->bands[band]->channels[j].flags &
1316                                                 IEEE80211_CHAN_DISABLED)
1317                                 continue;
1318
1319                         /* If we have a wireless request structure and the
1320                          * wireless request specifies frequencies, then search
1321                          * for the matching hardware channel.
1322                          */
1323                         if (wreq && wreq->num_channels) {
1324                                 int k;
1325                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1326                                 for (k = 0; k < wreq->num_channels; k++) {
1327                                         struct iw_freq *freq =
1328                                                 &wreq->channel_list[k];
1329                                         int wext_freq =
1330                                                 cfg80211_wext_freq(freq);
1331
1332                                         if (wext_freq == wiphy_freq)
1333                                                 goto wext_freq_found;
1334                                 }
1335                                 goto wext_freq_not_found;
1336                         }
1337
1338                 wext_freq_found:
1339                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1340                         i++;
1341                 wext_freq_not_found: ;
1342                 }
1343         }
1344         /* No channels found? */
1345         if (!i) {
1346                 err = -EINVAL;
1347                 goto out;
1348         }
1349
1350         /* Set real number of channels specified in creq->channels[] */
1351         creq->n_channels = i;
1352
1353         /* translate "Scan for SSID" request */
1354         if (wreq) {
1355                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1356                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1357                                 err = -EINVAL;
1358                                 goto out;
1359                         }
1360                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1361                         creq->ssids[0].ssid_len = wreq->essid_len;
1362                 }
1363                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1364                         creq->n_ssids = 0;
1365         }
1366
1367         for (i = 0; i < NUM_NL80211_BANDS; i++)
1368                 if (wiphy->bands[i])
1369                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1370
1371         eth_broadcast_addr(creq->bssid);
1372
1373         rdev->scan_req = creq;
1374         err = rdev_scan(rdev, creq);
1375         if (err) {
1376                 rdev->scan_req = NULL;
1377                 /* creq will be freed below */
1378         } else {
1379                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1380                 /* creq now owned by driver */
1381                 creq = NULL;
1382                 dev_hold(dev);
1383         }
1384  out:
1385         kfree(creq);
1386         return err;
1387 }
1388 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1389
1390 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1391                                     const struct cfg80211_bss_ies *ies,
1392                                     char *current_ev, char *end_buf)
1393 {
1394         const u8 *pos, *end, *next;
1395         struct iw_event iwe;
1396
1397         if (!ies)
1398                 return current_ev;
1399
1400         /*
1401          * If needed, fragment the IEs buffer (at IE boundaries) into short
1402          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1403          */
1404         pos = ies->data;
1405         end = pos + ies->len;
1406
1407         while (end - pos > IW_GENERIC_IE_MAX) {
1408                 next = pos + 2 + pos[1];
1409                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1410                         next = next + 2 + next[1];
1411
1412                 memset(&iwe, 0, sizeof(iwe));
1413                 iwe.cmd = IWEVGENIE;
1414                 iwe.u.data.length = next - pos;
1415                 current_ev = iwe_stream_add_point_check(info, current_ev,
1416                                                         end_buf, &iwe,
1417                                                         (void *)pos);
1418                 if (IS_ERR(current_ev))
1419                         return current_ev;
1420                 pos = next;
1421         }
1422
1423         if (end > pos) {
1424                 memset(&iwe, 0, sizeof(iwe));
1425                 iwe.cmd = IWEVGENIE;
1426                 iwe.u.data.length = end - pos;
1427                 current_ev = iwe_stream_add_point_check(info, current_ev,
1428                                                         end_buf, &iwe,
1429                                                         (void *)pos);
1430                 if (IS_ERR(current_ev))
1431                         return current_ev;
1432         }
1433
1434         return current_ev;
1435 }
1436
1437 static char *
1438 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1439               struct cfg80211_internal_bss *bss, char *current_ev,
1440               char *end_buf)
1441 {
1442         const struct cfg80211_bss_ies *ies;
1443         struct iw_event iwe;
1444         const u8 *ie;
1445         u8 buf[50];
1446         u8 *cfg, *p, *tmp;
1447         int rem, i, sig;
1448         bool ismesh = false;
1449
1450         memset(&iwe, 0, sizeof(iwe));
1451         iwe.cmd = SIOCGIWAP;
1452         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1453         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1454         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1455                                                 IW_EV_ADDR_LEN);
1456         if (IS_ERR(current_ev))
1457                 return current_ev;
1458
1459         memset(&iwe, 0, sizeof(iwe));
1460         iwe.cmd = SIOCGIWFREQ;
1461         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1462         iwe.u.freq.e = 0;
1463         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1464                                                 IW_EV_FREQ_LEN);
1465         if (IS_ERR(current_ev))
1466                 return current_ev;
1467
1468         memset(&iwe, 0, sizeof(iwe));
1469         iwe.cmd = SIOCGIWFREQ;
1470         iwe.u.freq.m = bss->pub.channel->center_freq;
1471         iwe.u.freq.e = 6;
1472         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1473                                                 IW_EV_FREQ_LEN);
1474         if (IS_ERR(current_ev))
1475                 return current_ev;
1476
1477         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1478                 memset(&iwe, 0, sizeof(iwe));
1479                 iwe.cmd = IWEVQUAL;
1480                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1481                                      IW_QUAL_NOISE_INVALID |
1482                                      IW_QUAL_QUAL_UPDATED;
1483                 switch (wiphy->signal_type) {
1484                 case CFG80211_SIGNAL_TYPE_MBM:
1485                         sig = bss->pub.signal / 100;
1486                         iwe.u.qual.level = sig;
1487                         iwe.u.qual.updated |= IW_QUAL_DBM;
1488                         if (sig < -110)         /* rather bad */
1489                                 sig = -110;
1490                         else if (sig > -40)     /* perfect */
1491                                 sig = -40;
1492                         /* will give a range of 0 .. 70 */
1493                         iwe.u.qual.qual = sig + 110;
1494                         break;
1495                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1496                         iwe.u.qual.level = bss->pub.signal;
1497                         /* will give range 0 .. 100 */
1498                         iwe.u.qual.qual = bss->pub.signal;
1499                         break;
1500                 default:
1501                         /* not reached */
1502                         break;
1503                 }
1504                 current_ev = iwe_stream_add_event_check(info, current_ev,
1505                                                         end_buf, &iwe,
1506                                                         IW_EV_QUAL_LEN);
1507                 if (IS_ERR(current_ev))
1508                         return current_ev;
1509         }
1510
1511         memset(&iwe, 0, sizeof(iwe));
1512         iwe.cmd = SIOCGIWENCODE;
1513         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1514                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1515         else
1516                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1517         iwe.u.data.length = 0;
1518         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1519                                                 &iwe, "");
1520         if (IS_ERR(current_ev))
1521                 return current_ev;
1522
1523         rcu_read_lock();
1524         ies = rcu_dereference(bss->pub.ies);
1525         rem = ies->len;
1526         ie = ies->data;
1527
1528         while (rem >= 2) {
1529                 /* invalid data */
1530                 if (ie[1] > rem - 2)
1531                         break;
1532
1533                 switch (ie[0]) {
1534                 case WLAN_EID_SSID:
1535                         memset(&iwe, 0, sizeof(iwe));
1536                         iwe.cmd = SIOCGIWESSID;
1537                         iwe.u.data.length = ie[1];
1538                         iwe.u.data.flags = 1;
1539                         current_ev = iwe_stream_add_point_check(info,
1540                                                                 current_ev,
1541                                                                 end_buf, &iwe,
1542                                                                 (u8 *)ie + 2);
1543                         if (IS_ERR(current_ev))
1544                                 goto unlock;
1545                         break;
1546                 case WLAN_EID_MESH_ID:
1547                         memset(&iwe, 0, sizeof(iwe));
1548                         iwe.cmd = SIOCGIWESSID;
1549                         iwe.u.data.length = ie[1];
1550                         iwe.u.data.flags = 1;
1551                         current_ev = iwe_stream_add_point_check(info,
1552                                                                 current_ev,
1553                                                                 end_buf, &iwe,
1554                                                                 (u8 *)ie + 2);
1555                         if (IS_ERR(current_ev))
1556                                 goto unlock;
1557                         break;
1558                 case WLAN_EID_MESH_CONFIG:
1559                         ismesh = true;
1560                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1561                                 break;
1562                         cfg = (u8 *)ie + 2;
1563                         memset(&iwe, 0, sizeof(iwe));
1564                         iwe.cmd = IWEVCUSTOM;
1565                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1566                                 "0x%02X", cfg[0]);
1567                         iwe.u.data.length = strlen(buf);
1568                         current_ev = iwe_stream_add_point_check(info,
1569                                                                 current_ev,
1570                                                                 end_buf,
1571                                                                 &iwe, buf);
1572                         if (IS_ERR(current_ev))
1573                                 goto unlock;
1574                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1575                                 cfg[1]);
1576                         iwe.u.data.length = strlen(buf);
1577                         current_ev = iwe_stream_add_point_check(info,
1578                                                                 current_ev,
1579                                                                 end_buf,
1580                                                                 &iwe, buf);
1581                         if (IS_ERR(current_ev))
1582                                 goto unlock;
1583                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1584                                 cfg[2]);
1585                         iwe.u.data.length = strlen(buf);
1586                         current_ev = iwe_stream_add_point_check(info,
1587                                                                 current_ev,
1588                                                                 end_buf,
1589                                                                 &iwe, buf);
1590                         if (IS_ERR(current_ev))
1591                                 goto unlock;
1592                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1593                         iwe.u.data.length = strlen(buf);
1594                         current_ev = iwe_stream_add_point_check(info,
1595                                                                 current_ev,
1596                                                                 end_buf,
1597                                                                 &iwe, buf);
1598                         if (IS_ERR(current_ev))
1599                                 goto unlock;
1600                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1601                         iwe.u.data.length = strlen(buf);
1602                         current_ev = iwe_stream_add_point_check(info,
1603                                                                 current_ev,
1604                                                                 end_buf,
1605                                                                 &iwe, buf);
1606                         if (IS_ERR(current_ev))
1607                                 goto unlock;
1608                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1609                         iwe.u.data.length = strlen(buf);
1610                         current_ev = iwe_stream_add_point_check(info,
1611                                                                 current_ev,
1612                                                                 end_buf,
1613                                                                 &iwe, buf);
1614                         if (IS_ERR(current_ev))
1615                                 goto unlock;
1616                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1617                         iwe.u.data.length = strlen(buf);
1618                         current_ev = iwe_stream_add_point_check(info,
1619                                                                 current_ev,
1620                                                                 end_buf,
1621                                                                 &iwe, buf);
1622                         if (IS_ERR(current_ev))
1623                                 goto unlock;
1624                         break;
1625                 case WLAN_EID_SUPP_RATES:
1626                 case WLAN_EID_EXT_SUPP_RATES:
1627                         /* display all supported rates in readable format */
1628                         p = current_ev + iwe_stream_lcp_len(info);
1629
1630                         memset(&iwe, 0, sizeof(iwe));
1631                         iwe.cmd = SIOCGIWRATE;
1632                         /* Those two flags are ignored... */
1633                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1634
1635                         for (i = 0; i < ie[1]; i++) {
1636                                 iwe.u.bitrate.value =
1637                                         ((ie[i + 2] & 0x7f) * 500000);
1638                                 tmp = p;
1639                                 p = iwe_stream_add_value(info, current_ev, p,
1640                                                          end_buf, &iwe,
1641                                                          IW_EV_PARAM_LEN);
1642                                 if (p == tmp) {
1643                                         current_ev = ERR_PTR(-E2BIG);
1644                                         goto unlock;
1645                                 }
1646                         }
1647                         current_ev = p;
1648                         break;
1649                 }
1650                 rem -= ie[1] + 2;
1651                 ie += ie[1] + 2;
1652         }
1653
1654         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1655             ismesh) {
1656                 memset(&iwe, 0, sizeof(iwe));
1657                 iwe.cmd = SIOCGIWMODE;
1658                 if (ismesh)
1659                         iwe.u.mode = IW_MODE_MESH;
1660                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1661                         iwe.u.mode = IW_MODE_MASTER;
1662                 else
1663                         iwe.u.mode = IW_MODE_ADHOC;
1664                 current_ev = iwe_stream_add_event_check(info, current_ev,
1665                                                         end_buf, &iwe,
1666                                                         IW_EV_UINT_LEN);
1667                 if (IS_ERR(current_ev))
1668                         goto unlock;
1669         }
1670
1671         memset(&iwe, 0, sizeof(iwe));
1672         iwe.cmd = IWEVCUSTOM;
1673         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1674         iwe.u.data.length = strlen(buf);
1675         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1676                                                 &iwe, buf);
1677         if (IS_ERR(current_ev))
1678                 goto unlock;
1679         memset(&iwe, 0, sizeof(iwe));
1680         iwe.cmd = IWEVCUSTOM;
1681         sprintf(buf, " Last beacon: %ums ago",
1682                 elapsed_jiffies_msecs(bss->ts));
1683         iwe.u.data.length = strlen(buf);
1684         current_ev = iwe_stream_add_point_check(info, current_ev,
1685                                                 end_buf, &iwe, buf);
1686         if (IS_ERR(current_ev))
1687                 goto unlock;
1688
1689         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1690
1691  unlock:
1692         rcu_read_unlock();
1693         return current_ev;
1694 }
1695
1696
1697 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1698                                   struct iw_request_info *info,
1699                                   char *buf, size_t len)
1700 {
1701         char *current_ev = buf;
1702         char *end_buf = buf + len;
1703         struct cfg80211_internal_bss *bss;
1704         int err = 0;
1705
1706         spin_lock_bh(&rdev->bss_lock);
1707         cfg80211_bss_expire(rdev);
1708
1709         list_for_each_entry(bss, &rdev->bss_list, list) {
1710                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1711                         err = -E2BIG;
1712                         break;
1713                 }
1714                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1715                                            current_ev, end_buf);
1716                 if (IS_ERR(current_ev)) {
1717                         err = PTR_ERR(current_ev);
1718                         break;
1719                 }
1720         }
1721         spin_unlock_bh(&rdev->bss_lock);
1722
1723         if (err)
1724                 return err;
1725         return current_ev - buf;
1726 }
1727
1728
1729 int cfg80211_wext_giwscan(struct net_device *dev,
1730                           struct iw_request_info *info,
1731                           struct iw_point *data, char *extra)
1732 {
1733         struct cfg80211_registered_device *rdev;
1734         int res;
1735
1736         if (!netif_running(dev))
1737                 return -ENETDOWN;
1738
1739         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1740
1741         if (IS_ERR(rdev))
1742                 return PTR_ERR(rdev);
1743
1744         if (rdev->scan_req || rdev->scan_msg)
1745                 return -EAGAIN;
1746
1747         res = ieee80211_scan_results(rdev, info, extra, data->length);
1748         data->length = 0;
1749         if (res >= 0) {
1750                 data->length = res;
1751                 res = 0;
1752         }
1753
1754         return res;
1755 }
1756 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1757 #endif