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 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
  61
  62 static void bss_free(struct cfg80211_internal_bss *bss)
  63 {
  64         struct cfg80211_bss_ies *ies;
  65
  66         if (WARN_ON(atomic_read(&bss->hold)))
  67                 return;
  68
  69         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
  70         if (ies && !bss->pub.hidden_beacon_bss)
  71                 kfree_rcu(ies, rcu_head);
  72         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
  73         if (ies)
  74                 kfree_rcu(ies, rcu_head);
  75
  76         /*
  77          * This happens when the module is removed, it doesn't
  78          * really matter any more save for completeness
  79          */
  80         if (!list_empty(&bss->hidden_list))
  81                 list_del(&bss->hidden_list);
  82
  83         kfree(bss);
  84 }
  85
  86 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
  87                                struct cfg80211_internal_bss *bss)
  88 {
  89         lockdep_assert_held(&rdev->bss_lock);
  90
  91         bss->refcount++;
  92         if (bss->pub.hidden_beacon_bss) {
  93                 bss = container_of(bss->pub.hidden_beacon_bss,
  94                                    struct cfg80211_internal_bss,
  95                                    pub);
  96                 bss->refcount++;
  97         }
  98 }
  99
 100 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
 101                                struct cfg80211_internal_bss *bss)
 102 {
 103         lockdep_assert_held(&rdev->bss_lock);
 104
 105         if (bss->pub.hidden_beacon_bss) {
 106                 struct cfg80211_internal_bss *hbss;
 107                 hbss = container_of(bss->pub.hidden_beacon_bss,
 108                                     struct cfg80211_internal_bss,
 109                                     pub);
 110                 hbss->refcount--;
 111                 if (hbss->refcount == 0)
 112                         bss_free(hbss);
 113         }
 114         bss->refcount--;
 115         if (bss->refcount == 0)
 116                 bss_free(bss);
 117 }
 118
 119 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
 120                                   struct cfg80211_internal_bss *bss)
 121 {
 122         lockdep_assert_held(&rdev->bss_lock);
 123
 124         if (!list_empty(&bss->hidden_list)) {
 125                 /*
 126                  * don't remove the beacon entry if it has
 127                  * probe responses associated with it
 128                  */
 129                 if (!bss->pub.hidden_beacon_bss)
 130                         return false;
 131                 /*
 132                  * if it's a probe response entry break its
 133                  * link to the other entries in the group
 134                  */
 135                 list_del_init(&bss->hidden_list);
 136         }
 137
 138         list_del_init(&bss->list);
 139         rb_erase(&bss->rbn, &rdev->bss_tree);
 140         bss_ref_put(rdev, bss);
 141         return true;
 142 }
 143
 144 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
 145                                   unsigned long expire_time)
 146 {
 147         struct cfg80211_internal_bss *bss, *tmp;
 148         bool expired = false;
 149
 150         lockdep_assert_held(&rdev->bss_lock);
 151
 152         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
 153                 if (atomic_read(&bss->hold))
 154                         continue;
 155                 if (!time_after(expire_time, bss->ts))
 156                         continue;
 157
 158                 if (__cfg80211_unlink_bss(rdev, bss))
 159                         expired = true;
 160         }
 161
 162         if (expired)
 163                 rdev->bss_generation++;
 164 }
 165
 166 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
 167                            bool send_message)
 168 {
 169         struct cfg80211_scan_request *request;
 170         struct wireless_dev *wdev;
 171         struct sk_buff *msg;
 172 #ifdef CONFIG_CFG80211_WEXT
 173         union iwreq_data wrqu;
 174 #endif
 175
 176         ASSERT_RTNL();
 177
 178         if (rdev->scan_msg) {
 179                 nl80211_send_scan_result(rdev, rdev->scan_msg);
 180                 rdev->scan_msg = NULL;
 181                 return;
 182         }
 183
 184         request = rdev->scan_req;
 185         if (!request)
 186                 return;
 187
 188         wdev = request->wdev;
 189
 190         /*
 191          * This must be before sending the other events!
 192          * Otherwise, wpa_supplicant gets completely confused with
 193          * wext events.
 194          */
 195         if (wdev->netdev)
 196                 cfg80211_sme_scan_done(wdev->netdev);
 197
 198         if (!request->info.aborted &&
 199             request->flags & NL80211_SCAN_FLAG_FLUSH) {
 200                 /* flush entries from previous scans */
 201                 spin_lock_bh(&rdev->bss_lock);
 202                 __cfg80211_bss_expire(rdev, request->scan_start);
 203                 spin_unlock_bh(&rdev->bss_lock);
 204         }
 205
 206         msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);
 207
 208 #ifdef CONFIG_CFG80211_WEXT
 209         if (wdev->netdev && !request->info.aborted) {
 210                 memset(&wrqu, 0, sizeof(wrqu));
 211
 212                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
 213         }
 214 #endif
 215
 216         if (wdev->netdev)
 217                 dev_put(wdev->netdev);
 218
 219         rdev->scan_req = NULL;
 220         kfree(request);
 221
 222         if (!send_message)
 223                 rdev->scan_msg = msg;
 224         else
 225                 nl80211_send_scan_result(rdev, msg);
 226 }
 227
 228 void __cfg80211_scan_done(struct work_struct *wk)
 229 {
 230         struct cfg80211_registered_device *rdev;
 231
 232         rdev = container_of(wk, struct cfg80211_registered_device,
 233                             scan_done_wk);
 234
 235         rtnl_lock();
 236         ___cfg80211_scan_done(rdev, true);
 237         rtnl_unlock();
 238 }
 239
 240 void cfg80211_scan_done(struct cfg80211_scan_request *request,
 241                         struct cfg80211_scan_info *info)
 242 {
 243         trace_cfg80211_scan_done(request, info);
 244         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
 245
 246         request->info = *info;
 247         request->notified = true;
 248         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
 249 }
 250 EXPORT_SYMBOL(cfg80211_scan_done);
 251
 252 void __cfg80211_sched_scan_results(struct work_struct *wk)
 253 {
 254         struct cfg80211_registered_device *rdev;
 255         struct cfg80211_sched_scan_request *request;
 256
 257         rdev = container_of(wk, struct cfg80211_registered_device,
 258                             sched_scan_results_wk);
 259
 260         rtnl_lock();
 261
 262         request = rtnl_dereference(rdev->sched_scan_req);
 263
 264         /* we don't have sched_scan_req anymore if the scan is stopping */
 265         if (request) {
 266                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
 267                         /* flush entries from previous scans */
 268                         spin_lock_bh(&rdev->bss_lock);
 269                         __cfg80211_bss_expire(rdev, request->scan_start);
 270                         spin_unlock_bh(&rdev->bss_lock);
 271                         request->scan_start = jiffies;
 272                 }
 273                 nl80211_send_sched_scan_results(rdev, request->dev);
 274         }
 275
 276         rtnl_unlock();
 277 }
 278
 279 void cfg80211_sched_scan_results(struct wiphy *wiphy)
 280 {
 281         trace_cfg80211_sched_scan_results(wiphy);
 282         /* ignore if we're not scanning */
 283
 284         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
 285                 queue_work(cfg80211_wq,
 286                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
 287 }
 288 EXPORT_SYMBOL(cfg80211_sched_scan_results);
 289
 290 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
 291 {
 292         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 293
 294         ASSERT_RTNL();
 295
 296         trace_cfg80211_sched_scan_stopped(wiphy);
 297
 298         __cfg80211_stop_sched_scan(rdev, true);
 299 }
 300 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
 301
 302 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
 303 {
 304         rtnl_lock();
 305         cfg80211_sched_scan_stopped_rtnl(wiphy);
 306         rtnl_unlock();
 307 }
 308 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
 309
 310 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 311                                bool driver_initiated)
 312 {
 313         struct cfg80211_sched_scan_request *sched_scan_req;
 314         struct net_device *dev;
 315
 316         ASSERT_RTNL();
 317
 318         if (!rdev->sched_scan_req)
 319                 return -ENOENT;
 320
 321         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
 322         dev = sched_scan_req->dev;
 323
 324         if (!driver_initiated) {
 325                 int err = rdev_sched_scan_stop(rdev, dev);
 326                 if (err)
 327                         return err;
 328         }
 329
 330         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
 331
 332         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
 333         kfree_rcu(sched_scan_req, rcu_head);
 334
 335         return 0;
 336 }
 337
 338 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
 339                       unsigned long age_secs)
 340 {
 341         struct cfg80211_internal_bss *bss;
 342         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 343
 344         spin_lock_bh(&rdev->bss_lock);
 345         list_for_each_entry(bss, &rdev->bss_list, list)
 346                 bss->ts -= age_jiffies;
 347         spin_unlock_bh(&rdev->bss_lock);
 348 }
 349
 350 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
 351 {
 352         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
 353 }
 354
 355 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
 356 {
 357         while (len > 2 && ies[0] != eid) {
 358                 len -= ies[1] + 2;
 359                 ies += ies[1] + 2;
 360         }
 361         if (len < 2)
 362                 return NULL;
 363         if (len < 2 + ies[1])
 364                 return NULL;
 365         return ies;
 366 }
 367 EXPORT_SYMBOL(cfg80211_find_ie);
 368
 369 const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
 370                                   const u8 *ies, int len)
 371 {
 372         struct ieee80211_vendor_ie *ie;
 373         const u8 *pos = ies, *end = ies + len;
 374         int ie_oui;
 375
 376         if (WARN_ON(oui_type > 0xff))
 377                 return NULL;
 378
 379         while (pos < end) {
 380                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
 381                                        end - pos);
 382                 if (!pos)
 383                         return NULL;
 384
 385                 ie = (struct ieee80211_vendor_ie *)pos;
 386
 387                 /* make sure we can access ie->len */
 388                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
 389
 390                 if (ie->len < sizeof(*ie))
 391                         goto cont;
 392
 393                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
 394                 if (ie_oui == oui &&
 395                     (oui_type < 0 || ie->oui_type == oui_type))
 396                         return pos;
 397 cont:
 398                 pos += 2 + ie->len;
 399         }
 400         return NULL;
 401 }
 402 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
 403
 404 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 405                    const u8 *ssid, size_t ssid_len)
 406 {
 407         const struct cfg80211_bss_ies *ies;
 408         const u8 *ssidie;
 409
 410         if (bssid && !ether_addr_equal(a->bssid, bssid))
 411                 return false;
 412
 413         if (!ssid)
 414                 return true;
 415
 416         ies = rcu_access_pointer(a->ies);
 417         if (!ies)
 418                 return false;
 419         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 420         if (!ssidie)
 421                 return false;
 422         if (ssidie[1] != ssid_len)
 423                 return false;
 424         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 425 }
 426
 427 /**
 428  * enum bss_compare_mode - BSS compare mode
 429  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
 430  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
 431  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
 432  */
 433 enum bss_compare_mode {
 434         BSS_CMP_REGULAR,
 435         BSS_CMP_HIDE_ZLEN,
 436         BSS_CMP_HIDE_NUL,
 437 };
 438
 439 static int cmp_bss(struct cfg80211_bss *a,
 440                    struct cfg80211_bss *b,
 441                    enum bss_compare_mode mode)
 442 {
 443         const struct cfg80211_bss_ies *a_ies, *b_ies;
 444         const u8 *ie1 = NULL;
 445         const u8 *ie2 = NULL;
 446         int i, r;
 447
 448         if (a->channel != b->channel)
 449                 return b->channel->center_freq - a->channel->center_freq;
 450
 451         a_ies = rcu_access_pointer(a->ies);
 452         if (!a_ies)
 453                 return -1;
 454         b_ies = rcu_access_pointer(b->ies);
 455         if (!b_ies)
 456                 return 1;
 457
 458         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
 459                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 460                                        a_ies->data, a_ies->len);
 461         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
 462                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
 463                                        b_ies->data, b_ies->len);
 464         if (ie1 && ie2) {
 465                 int mesh_id_cmp;
 466
 467                 if (ie1[1] == ie2[1])
 468                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 469                 else
 470                         mesh_id_cmp = ie2[1] - ie1[1];
 471
 472                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 473                                        a_ies->data, a_ies->len);
 474                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
 475                                        b_ies->data, b_ies->len);
 476                 if (ie1 && ie2) {
 477                         if (mesh_id_cmp)
 478                                 return mesh_id_cmp;
 479                         if (ie1[1] != ie2[1])
 480                                 return ie2[1] - ie1[1];
 481                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 482                 }
 483         }
 484
 485         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 486         if (r)
 487                 return r;
 488
 489         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
 490         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
 491
 492         if (!ie1 && !ie2)
 493                 return 0;
 494
 495         /*
 496          * Note that with "hide_ssid", the function returns a match if
 497          * the already-present BSS ("b") is a hidden SSID beacon for
 498          * the new BSS ("a").
 499          */
 500
 501         /* sort missing IE before (left of) present IE */
 502         if (!ie1)
 503                 return -1;
 504         if (!ie2)
 505                 return 1;
 506
 507         switch (mode) {
 508         case BSS_CMP_HIDE_ZLEN:
 509                 /*
 510                  * In ZLEN mode we assume the BSS entry we're
 511                  * looking for has a zero-length SSID. So if
 512                  * the one we're looking at right now has that,
 513                  * return 0. Otherwise, return the difference
 514                  * in length, but since we're looking for the
 515                  * 0-length it's really equivalent to returning
 516                  * the length of the one we're looking at.
 517                  *
 518                  * No content comparison is needed as we assume
 519                  * the content length is zero.
 520                  */
 521                 return ie2[1];
 522         case BSS_CMP_REGULAR:
 523         default:
 524                 /* sort by length first, then by contents */
 525                 if (ie1[1] != ie2[1])
 526                         return ie2[1] - ie1[1];
 527                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
 528         case BSS_CMP_HIDE_NUL:
 529                 if (ie1[1] != ie2[1])
 530                         return ie2[1] - ie1[1];
 531                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
 532                 for (i = 0; i < ie2[1]; i++)
 533                         if (ie2[i + 2])
 534                                 return -1;
 535                 return 0;
 536         }
 537 }
 538
 539 static bool cfg80211_bss_type_match(u16 capability,
 540                                     enum nl80211_band band,
 541                                     enum ieee80211_bss_type bss_type)
 542 {
 543         bool ret = true;
 544         u16 mask, val;
 545
 546         if (bss_type == IEEE80211_BSS_TYPE_ANY)
 547                 return ret;
 548
 549         if (band == NL80211_BAND_60GHZ) {
 550                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
 551                 switch (bss_type) {
 552                 case IEEE80211_BSS_TYPE_ESS:
 553                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
 554                         break;
 555                 case IEEE80211_BSS_TYPE_PBSS:
 556                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
 557                         break;
 558                 case IEEE80211_BSS_TYPE_IBSS:
 559                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
 560                         break;
 561                 default:
 562                         return false;
 563                 }
 564         } else {
 565                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
 566                 switch (bss_type) {
 567                 case IEEE80211_BSS_TYPE_ESS:
 568                         val = WLAN_CAPABILITY_ESS;
 569                         break;
 570                 case IEEE80211_BSS_TYPE_IBSS:
 571                         val = WLAN_CAPABILITY_IBSS;
 572                         break;
 573                 case IEEE80211_BSS_TYPE_MBSS:
 574                         val = 0;
 575                         break;
 576                 default:
 577                         return false;
 578                 }
 579         }
 580
 581         ret = ((capability & mask) == val);
 582         return ret;
 583 }
 584
 585 /* Returned bss is reference counted and must be cleaned up appropriately. */
 586 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 587                                       struct ieee80211_channel *channel,
 588                                       const u8 *bssid,
 589                                       const u8 *ssid, size_t ssid_len,
 590                                       enum ieee80211_bss_type bss_type,
 591                                       enum ieee80211_privacy privacy)
 592 {
 593         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 594         struct cfg80211_internal_bss *bss, *res = NULL;
 595         unsigned long now = jiffies;
 596         int bss_privacy;
 597
 598         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
 599                                privacy);
 600
 601         spin_lock_bh(&rdev->bss_lock);
 602
 603         list_for_each_entry(bss, &rdev->bss_list, list) {
 604                 if (!cfg80211_bss_type_match(bss->pub.capability,
 605                                              bss->pub.channel->band, bss_type))
 606                         continue;
 607
 608                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
 609                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
 610                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
 611                         continue;
 612                 if (channel && bss->pub.channel != channel)
 613                         continue;
 614                 if (!is_valid_ether_addr(bss->pub.bssid))
 615                         continue;
 616                 /* Don't get expired BSS structs */
 617                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
 618                     !atomic_read(&bss->hold))
 619                         continue;
 620                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 621                         res = bss;
 622                         bss_ref_get(rdev, res);
 623                         break;
 624                 }
 625         }
 626
 627         spin_unlock_bh(&rdev->bss_lock);
 628         if (!res)
 629                 return NULL;
 630         trace_cfg80211_return_bss(&res->pub);
 631         return &res->pub;
 632 }
 633 EXPORT_SYMBOL(cfg80211_get_bss);
 634
 635 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
 636                           struct cfg80211_internal_bss *bss)
 637 {
 638         struct rb_node **p = &rdev->bss_tree.rb_node;
 639         struct rb_node *parent = NULL;
 640         struct cfg80211_internal_bss *tbss;
 641         int cmp;
 642
 643         while (*p) {
 644                 parent = *p;
 645                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 646
 647                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 648
 649                 if (WARN_ON(!cmp)) {
 650                         /* will sort of leak this BSS */
 651                         return;
 652                 }
 653
 654                 if (cmp < 0)
 655                         p = &(*p)->rb_left;
 656                 else
 657                         p = &(*p)->rb_right;
 658         }
 659
 660         rb_link_node(&bss->rbn, parent, p);
 661         rb_insert_color(&bss->rbn, &rdev->bss_tree);
 662 }
 663
 664 static struct cfg80211_internal_bss *
 665 rb_find_bss(struct cfg80211_registered_device *rdev,
 666             struct cfg80211_internal_bss *res,
 667             enum bss_compare_mode mode)
 668 {
 669         struct rb_node *n = rdev->bss_tree.rb_node;
 670         struct cfg80211_internal_bss *bss;
 671         int r;
 672
 673         while (n) {
 674                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
 675                 r = cmp_bss(&res->pub, &bss->pub, mode);
 676
 677                 if (r == 0)
 678                         return bss;
 679                 else if (r < 0)
 680                         n = n->rb_left;
 681                 else
 682                         n = n->rb_right;
 683         }
 684
 685         return NULL;
 686 }
 687
 688 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
 689                                    struct cfg80211_internal_bss *new)
 690 {
 691         const struct cfg80211_bss_ies *ies;
 692         struct cfg80211_internal_bss *bss;
 693         const u8 *ie;
 694         int i, ssidlen;
 695         u8 fold = 0;
 696
 697         ies = rcu_access_pointer(new->pub.beacon_ies);
 698         if (WARN_ON(!ies))
 699                 return false;
 700
 701         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 702         if (!ie) {
 703                 /* nothing to do */
 704                 return true;
 705         }
 706
 707         ssidlen = ie[1];
 708         for (i = 0; i < ssidlen; i++)
 709                 fold |= ie[2 + i];
 710
 711         if (fold) {
 712                 /* not a hidden SSID */
 713                 return true;
 714         }
 715
 716         /* This is the bad part ... */
 717
 718         list_for_each_entry(bss, &rdev->bss_list, list) {
 719                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
 720                         continue;
 721                 if (bss->pub.channel != new->pub.channel)
 722                         continue;
 723                 if (bss->pub.scan_width != new->pub.scan_width)
 724                         continue;
 725                 if (rcu_access_pointer(bss->pub.beacon_ies))
 726                         continue;
 727                 ies = rcu_access_pointer(bss->pub.ies);
 728                 if (!ies)
 729                         continue;
 730                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
 731                 if (!ie)
 732                         continue;
 733                 if (ssidlen && ie[1] != ssidlen)
 734                         continue;
 735                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
 736                         continue;
 737                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
 738                         list_del(&bss->hidden_list);
 739                 /* combine them */
 740                 list_add(&bss->hidden_list, &new->hidden_list);
 741                 bss->pub.hidden_beacon_bss = &new->pub;
 742                 new->refcount += bss->refcount;
 743                 rcu_assign_pointer(bss->pub.beacon_ies,
 744                                    new->pub.beacon_ies);
 745         }
 746
 747         return true;
 748 }
 749
 750 /* Returned bss is reference counted and must be cleaned up appropriately. */
 751 static struct cfg80211_internal_bss *
 752 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 753                     struct cfg80211_internal_bss *tmp,
 754                     bool signal_valid)
 755 {
 756         struct cfg80211_internal_bss *found = NULL;
 757
 758         if (WARN_ON(!tmp->pub.channel))
 759                 return NULL;
 760
 761         tmp->ts = jiffies;
 762
 763         spin_lock_bh(&rdev->bss_lock);
 764
 765         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
 766                 spin_unlock_bh(&rdev->bss_lock);
 767                 return NULL;
 768         }
 769
 770         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
 771
 772         if (found) {
 773                 /* Update IEs */
 774                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 775                         const struct cfg80211_bss_ies *old;
 776
 777                         old = rcu_access_pointer(found->pub.proberesp_ies);
 778
 779                         rcu_assign_pointer(found->pub.proberesp_ies,
 780                                            tmp->pub.proberesp_ies);
 781                         /* Override possible earlier Beacon frame IEs */
 782                         rcu_assign_pointer(found->pub.ies,
 783                                            tmp->pub.proberesp_ies);
 784                         if (old)
 785                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 786                                           rcu_head);
 787                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
 788                         const struct cfg80211_bss_ies *old;
 789                         struct cfg80211_internal_bss *bss;
 790
 791                         if (found->pub.hidden_beacon_bss &&
 792                             !list_empty(&found->hidden_list)) {
 793                                 const struct cfg80211_bss_ies *f;
 794
 795                                 /*
 796                                  * The found BSS struct is one of the probe
 797                                  * response members of a group, but we're
 798                                  * receiving a beacon (beacon_ies in the tmp
 799                                  * bss is used). This can only mean that the
 800                                  * AP changed its beacon from not having an
 801                                  * SSID to showing it, which is confusing so
 802                                  * drop this information.
 803                                  */
 804
 805                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
 806                                 kfree_rcu((struct cfg80211_bss_ies *)f,
 807                                           rcu_head);
 808                                 goto drop;
 809                         }
 810
 811                         old = rcu_access_pointer(found->pub.beacon_ies);
 812
 813                         rcu_assign_pointer(found->pub.beacon_ies,
 814                                            tmp->pub.beacon_ies);
 815
 816                         /* Override IEs if they were from a beacon before */
 817                         if (old == rcu_access_pointer(found->pub.ies))
 818                                 rcu_assign_pointer(found->pub.ies,
 819                                                    tmp->pub.beacon_ies);
 820
 821                         /* Assign beacon IEs to all sub entries */
 822                         list_for_each_entry(bss, &found->hidden_list,
 823                                             hidden_list) {
 824                                 const struct cfg80211_bss_ies *ies;
 825
 826                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
 827                                 WARN_ON(ies != old);
 828
 829                                 rcu_assign_pointer(bss->pub.beacon_ies,
 830                                                    tmp->pub.beacon_ies);
 831                         }
 832
 833                         if (old)
 834                                 kfree_rcu((struct cfg80211_bss_ies *)old,
 835                                           rcu_head);
 836                 }
 837
 838                 found->pub.beacon_interval = tmp->pub.beacon_interval;
 839                 /*
 840                  * don't update the signal if beacon was heard on
 841                  * adjacent channel.
 842                  */
 843                 if (signal_valid)
 844                         found->pub.signal = tmp->pub.signal;
 845                 found->pub.capability = tmp->pub.capability;
 846                 found->ts = tmp->ts;
 847                 found->ts_boottime = tmp->ts_boottime;
 848                 found->parent_tsf = tmp->parent_tsf;
 849                 ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
 850         } else {
 851                 struct cfg80211_internal_bss *new;
 852                 struct cfg80211_internal_bss *hidden;
 853                 struct cfg80211_bss_ies *ies;
 854
 855                 /*
 856                  * create a copy -- the "res" variable that is passed in
 857                  * is allocated on the stack since it's not needed in the
 858                  * more common case of an update
 859                  */
 860                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
 861                               GFP_ATOMIC);
 862                 if (!new) {
 863                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
 864                         if (ies)
 865                                 kfree_rcu(ies, rcu_head);
 866                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 867                         if (ies)
 868                                 kfree_rcu(ies, rcu_head);
 869                         goto drop;
 870                 }
 871                 memcpy(new, tmp, sizeof(*new));
 872                 new->refcount = 1;
 873                 INIT_LIST_HEAD(&new->hidden_list);
 874
 875                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 876                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
 877                         if (!hidden)
 878                                 hidden = rb_find_bss(rdev, tmp,
 879                                                      BSS_CMP_HIDE_NUL);
 880                         if (hidden) {
 881                                 new->pub.hidden_beacon_bss = &hidden->pub;
 882                                 list_add(&new->hidden_list,
 883                                          &hidden->hidden_list);
 884                                 hidden->refcount++;
 885                                 rcu_assign_pointer(new->pub.beacon_ies,
 886                                                    hidden->pub.beacon_ies);
 887                         }
 888                 } else {
 889                         /*
 890                          * Ok so we found a beacon, and don't have an entry. If
 891                          * it's a beacon with hidden SSID, we might be in for an
 892                          * expensive search for any probe responses that should
 893                          * be grouped with this beacon for updates ...
 894                          */
 895                         if (!cfg80211_combine_bsses(rdev, new)) {
 896                                 kfree(new);
 897                                 goto drop;
 898                         }
 899                 }
 900
 901                 list_add_tail(&new->list, &rdev->bss_list);
 902                 rb_insert_bss(rdev, new);
 903                 found = new;
 904         }
 905
 906         rdev->bss_generation++;
 907         bss_ref_get(rdev, found);
 908         spin_unlock_bh(&rdev->bss_lock);
 909
 910         return found;
 911  drop:
 912         spin_unlock_bh(&rdev->bss_lock);
 913         return NULL;
 914 }
 915
 916 static struct ieee80211_channel *
 917 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
 918                          struct ieee80211_channel *channel)
 919 {
 920         const u8 *tmp;
 921         u32 freq;
 922         int channel_number = -1;
 923
 924         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
 925         if (tmp && tmp[1] == 1) {
 926                 channel_number = tmp[2];
 927         } else {
 928                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
 929                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
 930                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
 931
 932                         channel_number = htop->primary_chan;
 933                 }
 934         }
 935
 936         if (channel_number < 0)
 937                 return channel;
 938
 939         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
 940         channel = ieee80211_get_channel(wiphy, freq);
 941         if (!channel)
 942                 return NULL;
 943         if (channel->flags & IEEE80211_CHAN_DISABLED)
 944                 return NULL;
 945         return channel;
 946 }
 947
 948 /* Returned bss is reference counted and must be cleaned up appropriately. */
 949 struct cfg80211_bss *
 950 cfg80211_inform_bss_data(struct wiphy *wiphy,
 951                          struct cfg80211_inform_bss *data,
 952                          enum cfg80211_bss_frame_type ftype,
 953                          const u8 *bssid, u64 tsf, u16 capability,
 954                          u16 beacon_interval, const u8 *ie, size_t ielen,
 955                          gfp_t gfp)
 956 {
 957         struct cfg80211_bss_ies *ies;
 958         struct ieee80211_channel *channel;
 959         struct cfg80211_internal_bss tmp = {}, *res;
 960         int bss_type;
 961         bool signal_valid;
 962
 963         if (WARN_ON(!wiphy))
 964                 return NULL;
 965
 966         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
 967                     (data->signal < 0 || data->signal > 100)))
 968                 return NULL;
 969
 970         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
 971         if (!channel)
 972                 return NULL;
 973
 974         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 975         tmp.pub.channel = channel;
 976         tmp.pub.scan_width = data->scan_width;
 977         tmp.pub.signal = data->signal;
 978         tmp.pub.beacon_interval = beacon_interval;
 979         tmp.pub.capability = capability;
 980         tmp.ts_boottime = data->boottime_ns;
 981
 982         /*
 983          * If we do not know here whether the IEs are from a Beacon or Probe
 984          * Response frame, we need to pick one of the options and only use it
 985          * with the driver that does not provide the full Beacon/Probe Response
 986          * frame. Use Beacon frame pointer to avoid indicating that this should
 987          * override the IEs pointer should we have received an earlier
 988          * indication of Probe Response data.
 989          */
 990         ies = kzalloc(sizeof(*ies) + ielen, gfp);
 991         if (!ies)
 992                 return NULL;
 993         ies->len = ielen;
 994         ies->tsf = tsf;
 995         ies->from_beacon = false;
 996         memcpy(ies->data, ie, ielen);
 997
 998         switch (ftype) {
 999         case CFG80211_BSS_FTYPE_BEACON:
1000                 ies->from_beacon = true;
1001                 /* fall through to assign */
1002         case CFG80211_BSS_FTYPE_UNKNOWN:
1003                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1004                 break;
1005         case CFG80211_BSS_FTYPE_PRESP:
1006                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1007                 break;
1008         }
1009         rcu_assign_pointer(tmp.pub.ies, ies);
1010
1011         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1012                 wiphy->max_adj_channel_rssi_comp;
1013         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1014         if (!res)
1015                 return NULL;
1016
1017         if (channel->band == NL80211_BAND_60GHZ) {
1018                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1019                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1020                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1021                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1022         } else {
1023                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1024                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1025         }
1026
1027         trace_cfg80211_return_bss(&res->pub);
1028         /* cfg80211_bss_update gives us a referenced result */
1029         return &res->pub;
1030 }
1031 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1032
1033 /* cfg80211_inform_bss_width_frame helper */
1034 struct cfg80211_bss *
1035 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1036                                struct cfg80211_inform_bss *data,
1037                                struct ieee80211_mgmt *mgmt, size_t len,
1038                                gfp_t gfp)
1039
1040 {
1041         struct cfg80211_internal_bss tmp = {}, *res;
1042         struct cfg80211_bss_ies *ies;
1043         struct ieee80211_channel *channel;
1044         bool signal_valid;
1045         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1046                                       u.probe_resp.variable);
1047         int bss_type;
1048
1049         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1050                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1051
1052         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1053
1054         if (WARN_ON(!mgmt))
1055                 return NULL;
1056
1057         if (WARN_ON(!wiphy))
1058                 return NULL;
1059
1060         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1061                     (data->signal < 0 || data->signal > 100)))
1062                 return NULL;
1063
1064         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1065                 return NULL;
1066
1067         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1068                                            ielen, data->chan);
1069         if (!channel)
1070                 return NULL;
1071
1072         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1073         if (!ies)
1074                 return NULL;
1075         ies->len = ielen;
1076         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1077         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1078         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1079
1080         if (ieee80211_is_probe_resp(mgmt->frame_control))
1081                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1082         else
1083                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1084         rcu_assign_pointer(tmp.pub.ies, ies);
1085
1086         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1087         tmp.pub.channel = channel;
1088         tmp.pub.scan_width = data->scan_width;
1089         tmp.pub.signal = data->signal;
1090         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1091         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1092         tmp.ts_boottime = data->boottime_ns;
1093         tmp.parent_tsf = data->parent_tsf;
1094         ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
1095
1096         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1097                 wiphy->max_adj_channel_rssi_comp;
1098         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1099         if (!res)
1100                 return NULL;
1101
1102         if (channel->band == NL80211_BAND_60GHZ) {
1103                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1104                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1105                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1106                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1107         } else {
1108                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1109                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1110         }
1111
1112         trace_cfg80211_return_bss(&res->pub);
1113         /* cfg80211_bss_update gives us a referenced result */
1114         return &res->pub;
1115 }
1116 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1117
1118 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1119 {
1120         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1121         struct cfg80211_internal_bss *bss;
1122
1123         if (!pub)
1124                 return;
1125
1126         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1127
1128         spin_lock_bh(&rdev->bss_lock);
1129         bss_ref_get(rdev, bss);
1130         spin_unlock_bh(&rdev->bss_lock);
1131 }
1132 EXPORT_SYMBOL(cfg80211_ref_bss);
1133
1134 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1135 {
1136         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1137         struct cfg80211_internal_bss *bss;
1138
1139         if (!pub)
1140                 return;
1141
1142         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1143
1144         spin_lock_bh(&rdev->bss_lock);
1145         bss_ref_put(rdev, bss);
1146         spin_unlock_bh(&rdev->bss_lock);
1147 }
1148 EXPORT_SYMBOL(cfg80211_put_bss);
1149
1150 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1151 {
1152         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1153         struct cfg80211_internal_bss *bss;
1154
1155         if (WARN_ON(!pub))
1156                 return;
1157
1158         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1159
1160         spin_lock_bh(&rdev->bss_lock);
1161         if (!list_empty(&bss->list)) {
1162                 if (__cfg80211_unlink_bss(rdev, bss))
1163                         rdev->bss_generation++;
1164         }
1165         spin_unlock_bh(&rdev->bss_lock);
1166 }
1167 EXPORT_SYMBOL(cfg80211_unlink_bss);
1168
1169 #ifdef CONFIG_CFG80211_WEXT
1170 static struct cfg80211_registered_device *
1171 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1172 {
1173         struct cfg80211_registered_device *rdev;
1174         struct net_device *dev;
1175
1176         ASSERT_RTNL();
1177
1178         dev = dev_get_by_index(net, ifindex);
1179         if (!dev)
1180                 return ERR_PTR(-ENODEV);
1181         if (dev->ieee80211_ptr)
1182                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1183         else
1184                 rdev = ERR_PTR(-ENODEV);
1185         dev_put(dev);
1186         return rdev;
1187 }
1188
1189 int cfg80211_wext_siwscan(struct net_device *dev,
1190                           struct iw_request_info *info,
1191                           union iwreq_data *wrqu, char *extra)
1192 {
1193         struct cfg80211_registered_device *rdev;
1194         struct wiphy *wiphy;
1195         struct iw_scan_req *wreq = NULL;
1196         struct cfg80211_scan_request *creq = NULL;
1197         int i, err, n_channels = 0;
1198         enum nl80211_band band;
1199
1200         if (!netif_running(dev))
1201                 return -ENETDOWN;
1202
1203         if (wrqu->data.length == sizeof(struct iw_scan_req))
1204                 wreq = (struct iw_scan_req *)extra;
1205
1206         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1207
1208         if (IS_ERR(rdev))
1209                 return PTR_ERR(rdev);
1210
1211         if (rdev->scan_req || rdev->scan_msg) {
1212                 err = -EBUSY;
1213                 goto out;
1214         }
1215
1216         wiphy = &rdev->wiphy;
1217
1218         /* Determine number of channels, needed to allocate creq */
1219         if (wreq && wreq->num_channels)
1220                 n_channels = wreq->num_channels;
1221         else
1222                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1223
1224         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1225                        n_channels * sizeof(void *),
1226                        GFP_ATOMIC);
1227         if (!creq) {
1228                 err = -ENOMEM;
1229                 goto out;
1230         }
1231
1232         creq->wiphy = wiphy;
1233         creq->wdev = dev->ieee80211_ptr;
1234         /* SSIDs come after channels */
1235         creq->ssids = (void *)&creq->channels[n_channels];
1236         creq->n_channels = n_channels;
1237         creq->n_ssids = 1;
1238         creq->scan_start = jiffies;
1239
1240         /* translate "Scan on frequencies" request */
1241         i = 0;
1242         for (band = 0; band < NUM_NL80211_BANDS; band++) {
1243                 int j;
1244
1245                 if (!wiphy->bands[band])
1246                         continue;
1247
1248                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1249                         /* ignore disabled channels */
1250                         if (wiphy->bands[band]->channels[j].flags &
1251                                                 IEEE80211_CHAN_DISABLED)
1252                                 continue;
1253
1254                         /* If we have a wireless request structure and the
1255                          * wireless request specifies frequencies, then search
1256                          * for the matching hardware channel.
1257                          */
1258                         if (wreq && wreq->num_channels) {
1259                                 int k;
1260                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1261                                 for (k = 0; k < wreq->num_channels; k++) {
1262                                         struct iw_freq *freq =
1263                                                 &wreq->channel_list[k];
1264                                         int wext_freq =
1265                                                 cfg80211_wext_freq(freq);
1266
1267                                         if (wext_freq == wiphy_freq)
1268                                                 goto wext_freq_found;
1269                                 }
1270                                 goto wext_freq_not_found;
1271                         }
1272
1273                 wext_freq_found:
1274                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1275                         i++;
1276                 wext_freq_not_found: ;
1277                 }
1278         }
1279         /* No channels found? */
1280         if (!i) {
1281                 err = -EINVAL;
1282                 goto out;
1283         }
1284
1285         /* Set real number of channels specified in creq->channels[] */
1286         creq->n_channels = i;
1287
1288         /* translate "Scan for SSID" request */
1289         if (wreq) {
1290                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1291                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1292                                 err = -EINVAL;
1293                                 goto out;
1294                         }
1295                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1296                         creq->ssids[0].ssid_len = wreq->essid_len;
1297                 }
1298                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1299                         creq->n_ssids = 0;
1300         }
1301
1302         for (i = 0; i < NUM_NL80211_BANDS; i++)
1303                 if (wiphy->bands[i])
1304                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1305
1306         eth_broadcast_addr(creq->bssid);
1307
1308         rdev->scan_req = creq;
1309         err = rdev_scan(rdev, creq);
1310         if (err) {
1311                 rdev->scan_req = NULL;
1312                 /* creq will be freed below */
1313         } else {
1314                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1315                 /* creq now owned by driver */
1316                 creq = NULL;
1317                 dev_hold(dev);
1318         }
1319  out:
1320         kfree(creq);
1321         return err;
1322 }
1323 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1324
1325 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1326                                     const struct cfg80211_bss_ies *ies,
1327                                     char *current_ev, char *end_buf)
1328 {
1329         const u8 *pos, *end, *next;
1330         struct iw_event iwe;
1331
1332         if (!ies)
1333                 return current_ev;
1334
1335         /*
1336          * If needed, fragment the IEs buffer (at IE boundaries) into short
1337          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1338          */
1339         pos = ies->data;
1340         end = pos + ies->len;
1341
1342         while (end - pos > IW_GENERIC_IE_MAX) {
1343                 next = pos + 2 + pos[1];
1344                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1345                         next = next + 2 + next[1];
1346
1347                 memset(&iwe, 0, sizeof(iwe));
1348                 iwe.cmd = IWEVGENIE;
1349                 iwe.u.data.length = next - pos;
1350                 current_ev = iwe_stream_add_point_check(info, current_ev,
1351                                                         end_buf, &iwe,
1352                                                         (void *)pos);
1353                 if (IS_ERR(current_ev))
1354                         return current_ev;
1355                 pos = next;
1356         }
1357
1358         if (end > pos) {
1359                 memset(&iwe, 0, sizeof(iwe));
1360                 iwe.cmd = IWEVGENIE;
1361                 iwe.u.data.length = end - pos;
1362                 current_ev = iwe_stream_add_point_check(info, current_ev,
1363                                                         end_buf, &iwe,
1364                                                         (void *)pos);
1365                 if (IS_ERR(current_ev))
1366                         return current_ev;
1367         }
1368
1369         return current_ev;
1370 }
1371
1372 static char *
1373 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1374               struct cfg80211_internal_bss *bss, char *current_ev,
1375               char *end_buf)
1376 {
1377         const struct cfg80211_bss_ies *ies;
1378         struct iw_event iwe;
1379         const u8 *ie;
1380         u8 buf[50];
1381         u8 *cfg, *p, *tmp;
1382         int rem, i, sig;
1383         bool ismesh = false;
1384
1385         memset(&iwe, 0, sizeof(iwe));
1386         iwe.cmd = SIOCGIWAP;
1387         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1388         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1389         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1390                                                 IW_EV_ADDR_LEN);
1391         if (IS_ERR(current_ev))
1392                 return current_ev;
1393
1394         memset(&iwe, 0, sizeof(iwe));
1395         iwe.cmd = SIOCGIWFREQ;
1396         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1397         iwe.u.freq.e = 0;
1398         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1399                                                 IW_EV_FREQ_LEN);
1400         if (IS_ERR(current_ev))
1401                 return current_ev;
1402
1403         memset(&iwe, 0, sizeof(iwe));
1404         iwe.cmd = SIOCGIWFREQ;
1405         iwe.u.freq.m = bss->pub.channel->center_freq;
1406         iwe.u.freq.e = 6;
1407         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1408                                                 IW_EV_FREQ_LEN);
1409         if (IS_ERR(current_ev))
1410                 return current_ev;
1411
1412         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1413                 memset(&iwe, 0, sizeof(iwe));
1414                 iwe.cmd = IWEVQUAL;
1415                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1416                                      IW_QUAL_NOISE_INVALID |
1417                                      IW_QUAL_QUAL_UPDATED;
1418                 switch (wiphy->signal_type) {
1419                 case CFG80211_SIGNAL_TYPE_MBM:
1420                         sig = bss->pub.signal / 100;
1421                         iwe.u.qual.level = sig;
1422                         iwe.u.qual.updated |= IW_QUAL_DBM;
1423                         if (sig < -110)         /* rather bad */
1424                                 sig = -110;
1425                         else if (sig > -40)     /* perfect */
1426                                 sig = -40;
1427                         /* will give a range of 0 .. 70 */
1428                         iwe.u.qual.qual = sig + 110;
1429                         break;
1430                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1431                         iwe.u.qual.level = bss->pub.signal;
1432                         /* will give range 0 .. 100 */
1433                         iwe.u.qual.qual = bss->pub.signal;
1434                         break;
1435                 default:
1436                         /* not reached */
1437                         break;
1438                 }
1439                 current_ev = iwe_stream_add_event_check(info, current_ev,
1440                                                         end_buf, &iwe,
1441                                                         IW_EV_QUAL_LEN);
1442                 if (IS_ERR(current_ev))
1443                         return current_ev;
1444         }
1445
1446         memset(&iwe, 0, sizeof(iwe));
1447         iwe.cmd = SIOCGIWENCODE;
1448         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1449                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1450         else
1451                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1452         iwe.u.data.length = 0;
1453         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1454                                                 &iwe, "");
1455         if (IS_ERR(current_ev))
1456                 return current_ev;
1457
1458         rcu_read_lock();
1459         ies = rcu_dereference(bss->pub.ies);
1460         rem = ies->len;
1461         ie = ies->data;
1462
1463         while (rem >= 2) {
1464                 /* invalid data */
1465                 if (ie[1] > rem - 2)
1466                         break;
1467
1468                 switch (ie[0]) {
1469                 case WLAN_EID_SSID:
1470                         memset(&iwe, 0, sizeof(iwe));
1471                         iwe.cmd = SIOCGIWESSID;
1472                         iwe.u.data.length = ie[1];
1473                         iwe.u.data.flags = 1;
1474                         current_ev = iwe_stream_add_point_check(info,
1475                                                                 current_ev,
1476                                                                 end_buf, &iwe,
1477                                                                 (u8 *)ie + 2);
1478                         if (IS_ERR(current_ev))
1479                                 goto unlock;
1480                         break;
1481                 case WLAN_EID_MESH_ID:
1482                         memset(&iwe, 0, sizeof(iwe));
1483                         iwe.cmd = SIOCGIWESSID;
1484                         iwe.u.data.length = ie[1];
1485                         iwe.u.data.flags = 1;
1486                         current_ev = iwe_stream_add_point_check(info,
1487                                                                 current_ev,
1488                                                                 end_buf, &iwe,
1489                                                                 (u8 *)ie + 2);
1490                         if (IS_ERR(current_ev))
1491                                 goto unlock;
1492                         break;
1493                 case WLAN_EID_MESH_CONFIG:
1494                         ismesh = true;
1495                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1496                                 break;
1497                         cfg = (u8 *)ie + 2;
1498                         memset(&iwe, 0, sizeof(iwe));
1499                         iwe.cmd = IWEVCUSTOM;
1500                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1501                                 "0x%02X", cfg[0]);
1502                         iwe.u.data.length = strlen(buf);
1503                         current_ev = iwe_stream_add_point_check(info,
1504                                                                 current_ev,
1505                                                                 end_buf,
1506                                                                 &iwe, buf);
1507                         if (IS_ERR(current_ev))
1508                                 goto unlock;
1509                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1510                                 cfg[1]);
1511                         iwe.u.data.length = strlen(buf);
1512                         current_ev = iwe_stream_add_point_check(info,
1513                                                                 current_ev,
1514                                                                 end_buf,
1515                                                                 &iwe, buf);
1516                         if (IS_ERR(current_ev))
1517                                 goto unlock;
1518                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1519                                 cfg[2]);
1520                         iwe.u.data.length = strlen(buf);
1521                         current_ev = iwe_stream_add_point_check(info,
1522                                                                 current_ev,
1523                                                                 end_buf,
1524                                                                 &iwe, buf);
1525                         if (IS_ERR(current_ev))
1526                                 goto unlock;
1527                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1528                         iwe.u.data.length = strlen(buf);
1529                         current_ev = iwe_stream_add_point_check(info,
1530                                                                 current_ev,
1531                                                                 end_buf,
1532                                                                 &iwe, buf);
1533                         if (IS_ERR(current_ev))
1534                                 goto unlock;
1535                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1536                         iwe.u.data.length = strlen(buf);
1537                         current_ev = iwe_stream_add_point_check(info,
1538                                                                 current_ev,
1539                                                                 end_buf,
1540                                                                 &iwe, buf);
1541                         if (IS_ERR(current_ev))
1542                                 goto unlock;
1543                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1544                         iwe.u.data.length = strlen(buf);
1545                         current_ev = iwe_stream_add_point_check(info,
1546                                                                 current_ev,
1547                                                                 end_buf,
1548                                                                 &iwe, buf);
1549                         if (IS_ERR(current_ev))
1550                                 goto unlock;
1551                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1552                         iwe.u.data.length = strlen(buf);
1553                         current_ev = iwe_stream_add_point_check(info,
1554                                                                 current_ev,
1555                                                                 end_buf,
1556                                                                 &iwe, buf);
1557                         if (IS_ERR(current_ev))
1558                                 goto unlock;
1559                         break;
1560                 case WLAN_EID_SUPP_RATES:
1561                 case WLAN_EID_EXT_SUPP_RATES:
1562                         /* display all supported rates in readable format */
1563                         p = current_ev + iwe_stream_lcp_len(info);
1564
1565                         memset(&iwe, 0, sizeof(iwe));
1566                         iwe.cmd = SIOCGIWRATE;
1567                         /* Those two flags are ignored... */
1568                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1569
1570                         for (i = 0; i < ie[1]; i++) {
1571                                 iwe.u.bitrate.value =
1572                                         ((ie[i + 2] & 0x7f) * 500000);
1573                                 tmp = p;
1574                                 p = iwe_stream_add_value(info, current_ev, p,
1575                                                          end_buf, &iwe,
1576                                                          IW_EV_PARAM_LEN);
1577                                 if (p == tmp) {
1578                                         current_ev = ERR_PTR(-E2BIG);
1579                                         goto unlock;
1580                                 }
1581                         }
1582                         current_ev = p;
1583                         break;
1584                 }
1585                 rem -= ie[1] + 2;
1586                 ie += ie[1] + 2;
1587         }
1588
1589         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1590             ismesh) {
1591                 memset(&iwe, 0, sizeof(iwe));
1592                 iwe.cmd = SIOCGIWMODE;
1593                 if (ismesh)
1594                         iwe.u.mode = IW_MODE_MESH;
1595                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1596                         iwe.u.mode = IW_MODE_MASTER;
1597                 else
1598                         iwe.u.mode = IW_MODE_ADHOC;
1599                 current_ev = iwe_stream_add_event_check(info, current_ev,
1600                                                         end_buf, &iwe,
1601                                                         IW_EV_UINT_LEN);
1602                 if (IS_ERR(current_ev))
1603                         goto unlock;
1604         }
1605
1606         memset(&iwe, 0, sizeof(iwe));
1607         iwe.cmd = IWEVCUSTOM;
1608         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1609         iwe.u.data.length = strlen(buf);
1610         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1611                                                 &iwe, buf);
1612         if (IS_ERR(current_ev))
1613                 goto unlock;
1614         memset(&iwe, 0, sizeof(iwe));
1615         iwe.cmd = IWEVCUSTOM;
1616         sprintf(buf, " Last beacon: %ums ago",
1617                 elapsed_jiffies_msecs(bss->ts));
1618         iwe.u.data.length = strlen(buf);
1619         current_ev = iwe_stream_add_point_check(info, current_ev,
1620                                                 end_buf, &iwe, buf);
1621         if (IS_ERR(current_ev))
1622                 goto unlock;
1623
1624         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1625
1626  unlock:
1627         rcu_read_unlock();
1628         return current_ev;
1629 }
1630
1631
1632 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1633                                   struct iw_request_info *info,
1634                                   char *buf, size_t len)
1635 {
1636         char *current_ev = buf;
1637         char *end_buf = buf + len;
1638         struct cfg80211_internal_bss *bss;
1639         int err = 0;
1640
1641         spin_lock_bh(&rdev->bss_lock);
1642         cfg80211_bss_expire(rdev);
1643
1644         list_for_each_entry(bss, &rdev->bss_list, list) {
1645                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1646                         err = -E2BIG;
1647                         break;
1648                 }
1649                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1650                                            current_ev, end_buf);
1651                 if (IS_ERR(current_ev)) {
1652                         err = PTR_ERR(current_ev);
1653                         break;
1654                 }
1655         }
1656         spin_unlock_bh(&rdev->bss_lock);
1657
1658         if (err)
1659                 return err;
1660         return current_ev - buf;
1661 }
1662
1663
1664 int cfg80211_wext_giwscan(struct net_device *dev,
1665                           struct iw_request_info *info,
1666                           struct iw_point *data, char *extra)
1667 {
1668         struct cfg80211_registered_device *rdev;
1669         int res;
1670
1671         if (!netif_running(dev))
1672                 return -ENETDOWN;
1673
1674         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1675
1676         if (IS_ERR(rdev))
1677                 return PTR_ERR(rdev);
1678
1679         if (rdev->scan_req || rdev->scan_msg)
1680                 return -EAGAIN;
1681
1682         res = ieee80211_scan_results(rdev, info, extra, data->length);
1683         data->length = 0;
1684         if (res >= 0) {
1685                 data->length = res;
1686                 res = 0;
1687         }
1688
1689         return res;
1690 }
1691 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1692 #endif