net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/slab.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/rtnetlink.h>
  22 #include <net/mac80211.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "rate.h"
  27
  28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  30
  31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  32 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  33
  34 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  35
  36
  37 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  38                                       const u8 *bssid, const int beacon_int,
  39                                       struct ieee80211_channel *chan,
  40                                       const u32 basic_rates,
  41                                       const u16 capability, u64 tsf,
  42                                       bool creator)
  43 {
  44         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  45         struct ieee80211_local *local = sdata->local;
  46         int rates, i;
  47         struct sk_buff *skb;
  48         struct ieee80211_mgmt *mgmt;
  49         u8 *pos;
  50         struct ieee80211_supported_band *sband;
  51         struct cfg80211_bss *bss;
  52         u32 bss_change;
  53         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  54         struct cfg80211_chan_def chandef;
  55
  56         lockdep_assert_held(&ifibss->mtx);
  57
  58         /* Reset own TSF to allow time synchronization work. */
  59         drv_reset_tsf(local, sdata);
  60
  61         skb = ifibss->skb;
  62         RCU_INIT_POINTER(ifibss->presp, NULL);
  63         synchronize_rcu();
  64         skb->data = skb->head;
  65         skb->len = 0;
  66         skb_reset_tail_pointer(skb);
  67         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  68
  69         if (!ether_addr_equal(ifibss->bssid, bssid))
  70                 sta_info_flush(sdata);
  71
  72         /* if merging, indicate to driver that we leave the old IBSS */
  73         if (sdata->vif.bss_conf.ibss_joined) {
  74                 sdata->vif.bss_conf.ibss_joined = false;
  75                 sdata->vif.bss_conf.ibss_creator = false;
  76                 netif_carrier_off(sdata->dev);
  77                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
  78         }
  79
  80         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  81
  82         cfg80211_chandef_create(&chandef, chan, ifibss->channel_type);
  83         if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
  84                 chandef.width = NL80211_CHAN_WIDTH_20;
  85                 chandef.center_freq1 = chan->center_freq;
  86         }
  87
  88         ieee80211_vif_release_channel(sdata);
  89         if (ieee80211_vif_use_channel(sdata, &chandef,
  90                                       ifibss->fixed_channel ?
  91                                         IEEE80211_CHANCTX_SHARED :
  92                                         IEEE80211_CHANCTX_EXCLUSIVE)) {
  93                 sdata_info(sdata, "Failed to join IBSS, no channel context\n");
  94                 return;
  95         }
  96
  97         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  98
  99         sband = local->hw.wiphy->bands[chan->band];
 100
 101         /* build supported rates array */
 102         pos = supp_rates;
 103         for (i = 0; i < sband->n_bitrates; i++) {
 104                 int rate = sband->bitrates[i].bitrate;
 105                 u8 basic = 0;
 106                 if (basic_rates & BIT(i))
 107                         basic = 0x80;
 108                 *pos++ = basic | (u8) (rate / 5);
 109         }
 110
 111         /* Build IBSS probe response */
 112         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 113         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 114         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 115                                           IEEE80211_STYPE_PROBE_RESP);
 116         eth_broadcast_addr(mgmt->da);
 117         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 118         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 119         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 120         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 121         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 122
 123         pos = skb_put(skb, 2 + ifibss->ssid_len);
 124         *pos++ = WLAN_EID_SSID;
 125         *pos++ = ifibss->ssid_len;
 126         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 127
 128         rates = sband->n_bitrates;
 129         if (rates > 8)
 130                 rates = 8;
 131         pos = skb_put(skb, 2 + rates);
 132         *pos++ = WLAN_EID_SUPP_RATES;
 133         *pos++ = rates;
 134         memcpy(pos, supp_rates, rates);
 135
 136         if (sband->band == IEEE80211_BAND_2GHZ) {
 137                 pos = skb_put(skb, 2 + 1);
 138                 *pos++ = WLAN_EID_DS_PARAMS;
 139                 *pos++ = 1;
 140                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 141         }
 142
 143         pos = skb_put(skb, 2 + 2);
 144         *pos++ = WLAN_EID_IBSS_PARAMS;
 145         *pos++ = 2;
 146         /* FIX: set ATIM window based on scan results */
 147         *pos++ = 0;
 148         *pos++ = 0;
 149
 150         if (sband->n_bitrates > 8) {
 151                 rates = sband->n_bitrates - 8;
 152                 pos = skb_put(skb, 2 + rates);
 153                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 154                 *pos++ = rates;
 155                 memcpy(pos, &supp_rates[8], rates);
 156         }
 157
 158         if (ifibss->ie_len)
 159                 memcpy(skb_put(skb, ifibss->ie_len),
 160                        ifibss->ie, ifibss->ie_len);
 161
 162         /* add HT capability and information IEs */
 163         if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
 164             sband->ht_cap.ht_supported) {
 165                 pos = skb_put(skb, 4 +
 166                                    sizeof(struct ieee80211_ht_cap) +
 167                                    sizeof(struct ieee80211_ht_operation));
 168                 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
 169                                                 sband->ht_cap.cap);
 170                 /*
 171                  * Note: According to 802.11n-2009 9.13.3.1, HT Protection
 172                  * field and RIFS Mode are reserved in IBSS mode, therefore
 173                  * keep them at 0
 174                  */
 175                 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
 176                                                  &chandef, 0);
 177         }
 178
 179         if (local->hw.queues >= IEEE80211_NUM_ACS) {
 180                 pos = skb_put(skb, 9);
 181                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 182                 *pos++ = 7; /* len */
 183                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 184                 *pos++ = 0x50;
 185                 *pos++ = 0xf2;
 186                 *pos++ = 2; /* WME */
 187                 *pos++ = 0; /* WME info */
 188                 *pos++ = 1; /* WME ver */
 189                 *pos++ = 0; /* U-APSD no in use */
 190         }
 191
 192         rcu_assign_pointer(ifibss->presp, skb);
 193
 194         sdata->vif.bss_conf.enable_beacon = true;
 195         sdata->vif.bss_conf.beacon_int = beacon_int;
 196         sdata->vif.bss_conf.basic_rates = basic_rates;
 197         bss_change = BSS_CHANGED_BEACON_INT;
 198         bss_change |= ieee80211_reset_erp_info(sdata);
 199         bss_change |= BSS_CHANGED_BSSID;
 200         bss_change |= BSS_CHANGED_BEACON;
 201         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 202         bss_change |= BSS_CHANGED_BASIC_RATES;
 203         bss_change |= BSS_CHANGED_HT;
 204         bss_change |= BSS_CHANGED_IBSS;
 205
 206         /*
 207          * In 5 GHz/802.11a, we can always use short slot time.
 208          * (IEEE 802.11-2012 18.3.8.7)
 209          *
 210          * In 2.4GHz, we must always use long slots in IBSS for compatibility
 211          * reasons.
 212          * (IEEE 802.11-2012 19.4.5)
 213          *
 214          * HT follows these specifications (IEEE 802.11-2012 20.3.18)
 215          */
 216         sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
 217         bss_change |= BSS_CHANGED_ERP_SLOT;
 218
 219         sdata->vif.bss_conf.ibss_joined = true;
 220         sdata->vif.bss_conf.ibss_creator = creator;
 221         ieee80211_bss_info_change_notify(sdata, bss_change);
 222
 223         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 224
 225         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 226         mod_timer(&ifibss->timer,
 227                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 228
 229         bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
 230                                         mgmt, skb->len, 0, GFP_KERNEL);
 231         cfg80211_put_bss(bss);
 232         netif_carrier_on(sdata->dev);
 233         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 234 }
 235
 236 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 237                                     struct ieee80211_bss *bss)
 238 {
 239         struct cfg80211_bss *cbss =
 240                 container_of((void *)bss, struct cfg80211_bss, priv);
 241         struct ieee80211_supported_band *sband;
 242         u32 basic_rates;
 243         int i, j;
 244         u16 beacon_int = cbss->beacon_interval;
 245
 246         lockdep_assert_held(&sdata->u.ibss.mtx);
 247
 248         if (beacon_int < 10)
 249                 beacon_int = 10;
 250
 251         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 252
 253         basic_rates = 0;
 254
 255         for (i = 0; i < bss->supp_rates_len; i++) {
 256                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 257                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 258
 259                 for (j = 0; j < sband->n_bitrates; j++) {
 260                         if (sband->bitrates[j].bitrate == rate) {
 261                                 if (is_basic)
 262                                         basic_rates |= BIT(j);
 263                                 break;
 264                         }
 265                 }
 266         }
 267
 268         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 269                                   beacon_int,
 270                                   cbss->channel,
 271                                   basic_rates,
 272                                   cbss->capability,
 273                                   cbss->tsf,
 274                                   false);
 275 }
 276
 277 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
 278                                                   bool auth)
 279         __acquires(RCU)
 280 {
 281         struct ieee80211_sub_if_data *sdata = sta->sdata;
 282         u8 addr[ETH_ALEN];
 283
 284         memcpy(addr, sta->sta.addr, ETH_ALEN);
 285
 286         ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
 287
 288         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 289         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 290         /* authorize the station only if the network is not RSN protected. If
 291          * not wait for the userspace to authorize it */
 292         if (!sta->sdata->u.ibss.control_port)
 293                 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 294
 295         rate_control_rate_init(sta);
 296
 297         /* If it fails, maybe we raced another insertion? */
 298         if (sta_info_insert_rcu(sta))
 299                 return sta_info_get(sdata, addr);
 300         if (auth && !sdata->u.ibss.auth_frame_registrations) {
 301                 ibss_dbg(sdata,
 302                          "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
 303                          sdata->vif.addr, addr, sdata->u.ibss.bssid);
 304                 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
 305                                     addr, sdata->u.ibss.bssid, NULL, 0, 0);
 306         }
 307         return sta;
 308 }
 309
 310 static struct sta_info *
 311 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 312                        const u8 *bssid, const u8 *addr,
 313                        u32 supp_rates, bool auth)
 314         __acquires(RCU)
 315 {
 316         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 317         struct ieee80211_local *local = sdata->local;
 318         struct sta_info *sta;
 319         struct ieee80211_chanctx_conf *chanctx_conf;
 320         int band;
 321
 322         /*
 323          * XXX: Consider removing the least recently used entry and
 324          *      allow new one to be added.
 325          */
 326         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 327                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 328                                     sdata->name, addr);
 329                 rcu_read_lock();
 330                 return NULL;
 331         }
 332
 333         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
 334                 rcu_read_lock();
 335                 return NULL;
 336         }
 337
 338         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
 339                 rcu_read_lock();
 340                 return NULL;
 341         }
 342
 343         rcu_read_lock();
 344         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 345         if (WARN_ON_ONCE(!chanctx_conf))
 346                 return NULL;
 347         band = chanctx_conf->def.chan->band;
 348         rcu_read_unlock();
 349
 350         sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 351         if (!sta) {
 352                 rcu_read_lock();
 353                 return NULL;
 354         }
 355
 356         sta->last_rx = jiffies;
 357
 358         /* make sure mandatory rates are always added */
 359         sta->sta.supp_rates[band] = supp_rates |
 360                         ieee80211_mandatory_rates(local, band);
 361
 362         return ieee80211_ibss_finish_sta(sta, auth);
 363 }
 364
 365 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
 366                                           struct ieee80211_mgmt *mgmt,
 367                                           size_t len)
 368 {
 369         u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
 370
 371         if (len < IEEE80211_DEAUTH_FRAME_LEN)
 372                 return;
 373
 374         ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
 375                  mgmt->sa, mgmt->da, mgmt->bssid, reason);
 376         sta_info_destroy_addr(sdata, mgmt->sa);
 377 }
 378
 379 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
 380                                         struct ieee80211_mgmt *mgmt,
 381                                         size_t len)
 382 {
 383         u16 auth_alg, auth_transaction;
 384         struct sta_info *sta;
 385         u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
 386
 387         lockdep_assert_held(&sdata->u.ibss.mtx);
 388
 389         if (len < 24 + 6)
 390                 return;
 391
 392         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
 393         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
 394
 395         ibss_dbg(sdata,
 396                  "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
 397                  mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
 398
 399         if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
 400                 return;
 401
 402         sta_info_destroy_addr(sdata, mgmt->sa);
 403         sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
 404         rcu_read_unlock();
 405
 406         /*
 407          * if we have any problem in allocating the new station, we reply with a
 408          * DEAUTH frame to tell the other end that we had a problem
 409          */
 410         if (!sta) {
 411                 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
 412                                                IEEE80211_STYPE_DEAUTH,
 413                                                WLAN_REASON_UNSPECIFIED, true,
 414                                                deauth_frame_buf);
 415                 return;
 416         }
 417
 418         /*
 419          * IEEE 802.11 standard does not require authentication in IBSS
 420          * networks and most implementations do not seem to use it.
 421          * However, try to reply to authentication attempts if someone
 422          * has actually implemented this.
 423          */
 424         ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
 425                             mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0);
 426 }
 427
 428 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 429                                   struct ieee80211_mgmt *mgmt, size_t len,
 430                                   struct ieee80211_rx_status *rx_status,
 431                                   struct ieee802_11_elems *elems)
 432 {
 433         struct ieee80211_local *local = sdata->local;
 434         int freq;
 435         struct cfg80211_bss *cbss;
 436         struct ieee80211_bss *bss;
 437         struct sta_info *sta;
 438         struct ieee80211_channel *channel;
 439         u64 beacon_timestamp, rx_timestamp;
 440         u32 supp_rates = 0;
 441         enum ieee80211_band band = rx_status->band;
 442         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 443         bool rates_updated = false;
 444
 445         if (elems->ds_params && elems->ds_params_len == 1)
 446                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
 447                                                       band);
 448         else
 449                 freq = rx_status->freq;
 450
 451         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 452
 453         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 454                 return;
 455
 456         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 457             ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
 458
 459                 rcu_read_lock();
 460                 sta = sta_info_get(sdata, mgmt->sa);
 461
 462                 if (elems->supp_rates) {
 463                         supp_rates = ieee80211_sta_get_rates(local, elems,
 464                                                              band, NULL);
 465                         if (sta) {
 466                                 u32 prev_rates;
 467
 468                                 prev_rates = sta->sta.supp_rates[band];
 469                                 /* make sure mandatory rates are always added */
 470                                 sta->sta.supp_rates[band] = supp_rates |
 471                                         ieee80211_mandatory_rates(local, band);
 472
 473                                 if (sta->sta.supp_rates[band] != prev_rates) {
 474                                         ibss_dbg(sdata,
 475                                                  "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
 476                                                  sta->sta.addr, prev_rates,
 477                                                  sta->sta.supp_rates[band]);
 478                                         rates_updated = true;
 479                                 }
 480                         } else {
 481                                 rcu_read_unlock();
 482                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
 483                                                 mgmt->sa, supp_rates, true);
 484                         }
 485                 }
 486
 487                 if (sta && elems->wmm_info)
 488                         set_sta_flag(sta, WLAN_STA_WME);
 489
 490                 if (sta && elems->ht_operation && elems->ht_cap_elem &&
 491                     sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
 492                         /* we both use HT */
 493                         struct ieee80211_sta_ht_cap sta_ht_cap_new;
 494                         struct cfg80211_chan_def chandef;
 495
 496                         ieee80211_ht_oper_to_chandef(channel,
 497                                                      elems->ht_operation,
 498                                                      &chandef);
 499
 500                         ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 501                                                           elems->ht_cap_elem,
 502                                                           &sta_ht_cap_new);
 503
 504                         /*
 505                          * fall back to HT20 if we don't use or use
 506                          * the other extension channel
 507                          */
 508                         if (chandef.width != NL80211_CHAN_WIDTH_40 ||
 509                             cfg80211_get_chandef_type(&chandef) !=
 510                                                 sdata->u.ibss.channel_type)
 511                                 sta_ht_cap_new.cap &=
 512                                         ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 513
 514                         if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
 515                                    sizeof(sta_ht_cap_new))) {
 516                                 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
 517                                        sizeof(sta_ht_cap_new));
 518                                 rates_updated = true;
 519                         }
 520                 }
 521
 522                 if (sta && rates_updated) {
 523                         drv_sta_rc_update(local, sdata, &sta->sta,
 524                                           IEEE80211_RC_SUPP_RATES_CHANGED);
 525                         rate_control_rate_init(sta);
 526                 }
 527
 528                 rcu_read_unlock();
 529         }
 530
 531         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 532                                         channel);
 533         if (!bss)
 534                 return;
 535
 536         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 537
 538         /* was just updated in ieee80211_bss_info_update */
 539         beacon_timestamp = cbss->tsf;
 540
 541         /* check if we need to merge IBSS */
 542
 543         /* we use a fixed BSSID */
 544         if (sdata->u.ibss.fixed_bssid)
 545                 goto put_bss;
 546
 547         /* not an IBSS */
 548         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 549                 goto put_bss;
 550
 551         /* different channel */
 552         if (sdata->u.ibss.fixed_channel &&
 553             sdata->u.ibss.channel != cbss->channel)
 554                 goto put_bss;
 555
 556         /* different SSID */
 557         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 558             memcmp(elems->ssid, sdata->u.ibss.ssid,
 559                                 sdata->u.ibss.ssid_len))
 560                 goto put_bss;
 561
 562         /* same BSSID */
 563         if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
 564                 goto put_bss;
 565
 566         if (ieee80211_have_rx_timestamp(rx_status)) {
 567                 /* time when timestamp field was received */
 568                 rx_timestamp =
 569                         ieee80211_calculate_rx_timestamp(local, rx_status,
 570                                                          len + FCS_LEN, 24);
 571         } else {
 572                 /*
 573                  * second best option: get current TSF
 574                  * (will return -1 if not supported)
 575                  */
 576                 rx_timestamp = drv_get_tsf(local, sdata);
 577         }
 578
 579         ibss_dbg(sdata,
 580                  "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 581                  mgmt->sa, mgmt->bssid,
 582                  (unsigned long long)rx_timestamp,
 583                  (unsigned long long)beacon_timestamp,
 584                  (unsigned long long)(rx_timestamp - beacon_timestamp),
 585                  jiffies);
 586
 587         if (beacon_timestamp > rx_timestamp) {
 588                 ibss_dbg(sdata,
 589                          "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
 590                          mgmt->bssid);
 591                 ieee80211_sta_join_ibss(sdata, bss);
 592                 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
 593                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 594                                        supp_rates, true);
 595                 rcu_read_unlock();
 596         }
 597
 598  put_bss:
 599         ieee80211_rx_bss_put(local, bss);
 600 }
 601
 602 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
 603                               const u8 *bssid, const u8 *addr,
 604                               u32 supp_rates)
 605 {
 606         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 607         struct ieee80211_local *local = sdata->local;
 608         struct sta_info *sta;
 609         struct ieee80211_chanctx_conf *chanctx_conf;
 610         int band;
 611
 612         /*
 613          * XXX: Consider removing the least recently used entry and
 614          *      allow new one to be added.
 615          */
 616         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 617                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 618                                     sdata->name, addr);
 619                 return;
 620         }
 621
 622         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 623                 return;
 624
 625         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
 626                 return;
 627
 628         rcu_read_lock();
 629         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 630         if (WARN_ON_ONCE(!chanctx_conf)) {
 631                 rcu_read_unlock();
 632                 return;
 633         }
 634         band = chanctx_conf->def.chan->band;
 635         rcu_read_unlock();
 636
 637         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 638         if (!sta)
 639                 return;
 640
 641         sta->last_rx = jiffies;
 642
 643         /* make sure mandatory rates are always added */
 644         sta->sta.supp_rates[band] = supp_rates |
 645                         ieee80211_mandatory_rates(local, band);
 646
 647         spin_lock(&ifibss->incomplete_lock);
 648         list_add(&sta->list, &ifibss->incomplete_stations);
 649         spin_unlock(&ifibss->incomplete_lock);
 650         ieee80211_queue_work(&local->hw, &sdata->work);
 651 }
 652
 653 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 654 {
 655         struct ieee80211_local *local = sdata->local;
 656         int active = 0;
 657         struct sta_info *sta;
 658
 659         lockdep_assert_held(&sdata->u.ibss.mtx);
 660
 661         rcu_read_lock();
 662
 663         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 664                 if (sta->sdata == sdata &&
 665                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 666                                jiffies)) {
 667                         active++;
 668                         break;
 669                 }
 670         }
 671
 672         rcu_read_unlock();
 673
 674         return active;
 675 }
 676
 677 /*
 678  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 679  */
 680
 681 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 682 {
 683         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 684
 685         lockdep_assert_held(&ifibss->mtx);
 686
 687         mod_timer(&ifibss->timer,
 688                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 689
 690         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 691
 692         if (time_before(jiffies, ifibss->last_scan_completed +
 693                        IEEE80211_IBSS_MERGE_INTERVAL))
 694                 return;
 695
 696         if (ieee80211_sta_active_ibss(sdata))
 697                 return;
 698
 699         if (ifibss->fixed_channel)
 700                 return;
 701
 702         sdata_info(sdata,
 703                    "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
 704
 705         ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
 706                                     NULL);
 707 }
 708
 709 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 710 {
 711         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 712         u8 bssid[ETH_ALEN];
 713         u16 capability;
 714         int i;
 715
 716         lockdep_assert_held(&ifibss->mtx);
 717
 718         if (ifibss->fixed_bssid) {
 719                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 720         } else {
 721                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 722                  * own MAC address to make sure that devices that do not have proper
 723                  * random number generator get different BSSID. */
 724                 get_random_bytes(bssid, ETH_ALEN);
 725                 for (i = 0; i < ETH_ALEN; i++)
 726                         bssid[i] ^= sdata->vif.addr[i];
 727                 bssid[0] &= ~0x01;
 728                 bssid[0] |= 0x02;
 729         }
 730
 731         sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
 732
 733         capability = WLAN_CAPABILITY_IBSS;
 734
 735         if (ifibss->privacy)
 736                 capability |= WLAN_CAPABILITY_PRIVACY;
 737         else
 738                 sdata->drop_unencrypted = 0;
 739
 740         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 741                                   ifibss->channel, ifibss->basic_rates,
 742                                   capability, 0, true);
 743 }
 744
 745 /*
 746  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 747  */
 748
 749 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 750 {
 751         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 752         struct ieee80211_local *local = sdata->local;
 753         struct cfg80211_bss *cbss;
 754         struct ieee80211_channel *chan = NULL;
 755         const u8 *bssid = NULL;
 756         int active_ibss;
 757         u16 capability;
 758
 759         lockdep_assert_held(&ifibss->mtx);
 760
 761         active_ibss = ieee80211_sta_active_ibss(sdata);
 762         ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
 763
 764         if (active_ibss)
 765                 return;
 766
 767         capability = WLAN_CAPABILITY_IBSS;
 768         if (ifibss->privacy)
 769                 capability |= WLAN_CAPABILITY_PRIVACY;
 770         if (ifibss->fixed_bssid)
 771                 bssid = ifibss->bssid;
 772         if (ifibss->fixed_channel)
 773                 chan = ifibss->channel;
 774         if (!is_zero_ether_addr(ifibss->bssid))
 775                 bssid = ifibss->bssid;
 776         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 777                                 ifibss->ssid, ifibss->ssid_len,
 778                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 779                                 capability);
 780
 781         if (cbss) {
 782                 struct ieee80211_bss *bss;
 783
 784                 bss = (void *)cbss->priv;
 785                 ibss_dbg(sdata,
 786                          "sta_find_ibss: selected %pM current %pM\n",
 787                          cbss->bssid, ifibss->bssid);
 788                 sdata_info(sdata,
 789                            "Selected IBSS BSSID %pM based on configured SSID\n",
 790                            cbss->bssid);
 791
 792                 ieee80211_sta_join_ibss(sdata, bss);
 793                 ieee80211_rx_bss_put(local, bss);
 794                 return;
 795         }
 796
 797         ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
 798
 799         /* Selected IBSS not found in current scan results - try to scan */
 800         if (time_after(jiffies, ifibss->last_scan_completed +
 801                                         IEEE80211_SCAN_INTERVAL)) {
 802                 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 803
 804                 ieee80211_request_ibss_scan(sdata, ifibss->ssid,
 805                                             ifibss->ssid_len, chan);
 806         } else {
 807                 int interval = IEEE80211_SCAN_INTERVAL;
 808
 809                 if (time_after(jiffies, ifibss->ibss_join_req +
 810                                IEEE80211_IBSS_JOIN_TIMEOUT))
 811                         ieee80211_sta_create_ibss(sdata);
 812
 813                 mod_timer(&ifibss->timer,
 814                           round_jiffies(jiffies + interval));
 815         }
 816 }
 817
 818 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 819                                         struct sk_buff *req)
 820 {
 821         struct ieee80211_mgmt *mgmt = (void *)req->data;
 822         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 823         struct ieee80211_local *local = sdata->local;
 824         int tx_last_beacon, len = req->len;
 825         struct sk_buff *skb;
 826         struct ieee80211_mgmt *resp;
 827         struct sk_buff *presp;
 828         u8 *pos, *end;
 829
 830         lockdep_assert_held(&ifibss->mtx);
 831
 832         presp = rcu_dereference_protected(ifibss->presp,
 833                                           lockdep_is_held(&ifibss->mtx));
 834
 835         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 836             len < 24 + 2 || !presp)
 837                 return;
 838
 839         tx_last_beacon = drv_tx_last_beacon(local);
 840
 841         ibss_dbg(sdata,
 842                  "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
 843                  mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
 844
 845         if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
 846                 return;
 847
 848         if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
 849             !is_broadcast_ether_addr(mgmt->bssid))
 850                 return;
 851
 852         end = ((u8 *) mgmt) + len;
 853         pos = mgmt->u.probe_req.variable;
 854         if (pos[0] != WLAN_EID_SSID ||
 855             pos + 2 + pos[1] > end) {
 856                 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
 857                          mgmt->sa);
 858                 return;
 859         }
 860         if (pos[1] != 0 &&
 861             (pos[1] != ifibss->ssid_len ||
 862              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 863                 /* Ignore ProbeReq for foreign SSID */
 864                 return;
 865         }
 866
 867         /* Reply with ProbeResp */
 868         skb = skb_copy(presp, GFP_KERNEL);
 869         if (!skb)
 870                 return;
 871
 872         resp = (struct ieee80211_mgmt *) skb->data;
 873         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 874         ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
 875         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 876         ieee80211_tx_skb(sdata, skb);
 877 }
 878
 879 static
 880 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
 881                                     struct ieee80211_mgmt *mgmt, size_t len,
 882                                     struct ieee80211_rx_status *rx_status)
 883 {
 884         size_t baselen;
 885         struct ieee802_11_elems elems;
 886
 887         BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
 888                      offsetof(typeof(mgmt->u.beacon), variable));
 889
 890         /*
 891          * either beacon or probe_resp but the variable field is at the
 892          * same offset
 893          */
 894         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 895         if (baselen > len)
 896                 return;
 897
 898         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 899                                 &elems);
 900
 901         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
 902 }
 903
 904 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 905                                    struct sk_buff *skb)
 906 {
 907         struct ieee80211_rx_status *rx_status;
 908         struct ieee80211_mgmt *mgmt;
 909         u16 fc;
 910
 911         rx_status = IEEE80211_SKB_RXCB(skb);
 912         mgmt = (struct ieee80211_mgmt *) skb->data;
 913         fc = le16_to_cpu(mgmt->frame_control);
 914
 915         mutex_lock(&sdata->u.ibss.mtx);
 916
 917         if (!sdata->u.ibss.ssid_len)
 918                 goto mgmt_out; /* not ready to merge yet */
 919
 920         switch (fc & IEEE80211_FCTL_STYPE) {
 921         case IEEE80211_STYPE_PROBE_REQ:
 922                 ieee80211_rx_mgmt_probe_req(sdata, skb);
 923                 break;
 924         case IEEE80211_STYPE_PROBE_RESP:
 925         case IEEE80211_STYPE_BEACON:
 926                 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
 927                                                rx_status);
 928                 break;
 929         case IEEE80211_STYPE_AUTH:
 930                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 931                 break;
 932         case IEEE80211_STYPE_DEAUTH:
 933                 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
 934                 break;
 935         }
 936
 937  mgmt_out:
 938         mutex_unlock(&sdata->u.ibss.mtx);
 939 }
 940
 941 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 942 {
 943         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 944         struct sta_info *sta;
 945
 946         mutex_lock(&ifibss->mtx);
 947
 948         /*
 949          * Work could be scheduled after scan or similar
 950          * when we aren't even joined (or trying) with a
 951          * network.
 952          */
 953         if (!ifibss->ssid_len)
 954                 goto out;
 955
 956         spin_lock_bh(&ifibss->incomplete_lock);
 957         while (!list_empty(&ifibss->incomplete_stations)) {
 958                 sta = list_first_entry(&ifibss->incomplete_stations,
 959                                        struct sta_info, list);
 960                 list_del(&sta->list);
 961                 spin_unlock_bh(&ifibss->incomplete_lock);
 962
 963                 ieee80211_ibss_finish_sta(sta, true);
 964                 rcu_read_unlock();
 965                 spin_lock_bh(&ifibss->incomplete_lock);
 966         }
 967         spin_unlock_bh(&ifibss->incomplete_lock);
 968
 969         switch (ifibss->state) {
 970         case IEEE80211_IBSS_MLME_SEARCH:
 971                 ieee80211_sta_find_ibss(sdata);
 972                 break;
 973         case IEEE80211_IBSS_MLME_JOINED:
 974                 ieee80211_sta_merge_ibss(sdata);
 975                 break;
 976         default:
 977                 WARN_ON(1);
 978                 break;
 979         }
 980
 981  out:
 982         mutex_unlock(&ifibss->mtx);
 983 }
 984
 985 static void ieee80211_ibss_timer(unsigned long data)
 986 {
 987         struct ieee80211_sub_if_data *sdata =
 988                 (struct ieee80211_sub_if_data *) data;
 989         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 990         struct ieee80211_local *local = sdata->local;
 991
 992         if (local->quiescing) {
 993                 ifibss->timer_running = true;
 994                 return;
 995         }
 996
 997         ieee80211_queue_work(&local->hw, &sdata->work);
 998 }
 999
1000 #ifdef CONFIG_PM
1001 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
1002 {
1003         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1004
1005         if (del_timer_sync(&ifibss->timer))
1006                 ifibss->timer_running = true;
1007 }
1008
1009 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
1010 {
1011         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1012
1013         if (ifibss->timer_running) {
1014                 add_timer(&ifibss->timer);
1015                 ifibss->timer_running = false;
1016         }
1017 }
1018 #endif
1019
1020 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1021 {
1022         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1023
1024         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1025                     (unsigned long) sdata);
1026         mutex_init(&ifibss->mtx);
1027         INIT_LIST_HEAD(&ifibss->incomplete_stations);
1028         spin_lock_init(&ifibss->incomplete_lock);
1029 }
1030
1031 /* scan finished notification */
1032 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1033 {
1034         struct ieee80211_sub_if_data *sdata;
1035
1036         mutex_lock(&local->iflist_mtx);
1037         list_for_each_entry(sdata, &local->interfaces, list) {
1038                 if (!ieee80211_sdata_running(sdata))
1039                         continue;
1040                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1041                         continue;
1042                 sdata->u.ibss.last_scan_completed = jiffies;
1043                 ieee80211_queue_work(&local->hw, &sdata->work);
1044         }
1045         mutex_unlock(&local->iflist_mtx);
1046 }
1047
1048 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1049                         struct cfg80211_ibss_params *params)
1050 {
1051         struct sk_buff *skb;
1052         u32 changed = 0;
1053
1054         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
1055                             sizeof(struct ieee80211_hdr_3addr) +
1056                             12 /* struct ieee80211_mgmt.u.beacon */ +
1057                             2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
1058                             2 + 8 /* max Supported Rates */ +
1059                             3 /* max DS params */ +
1060                             4 /* IBSS params */ +
1061                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
1062                             2 + sizeof(struct ieee80211_ht_cap) +
1063                             2 + sizeof(struct ieee80211_ht_operation) +
1064                             params->ie_len);
1065         if (!skb)
1066                 return -ENOMEM;
1067
1068         mutex_lock(&sdata->u.ibss.mtx);
1069
1070         if (params->bssid) {
1071                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1072                 sdata->u.ibss.fixed_bssid = true;
1073         } else
1074                 sdata->u.ibss.fixed_bssid = false;
1075
1076         sdata->u.ibss.privacy = params->privacy;
1077         sdata->u.ibss.control_port = params->control_port;
1078         sdata->u.ibss.basic_rates = params->basic_rates;
1079         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1080                sizeof(params->mcast_rate));
1081
1082         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1083
1084         sdata->u.ibss.channel = params->chandef.chan;
1085         sdata->u.ibss.channel_type =
1086                 cfg80211_get_chandef_type(&params->chandef);
1087         sdata->u.ibss.fixed_channel = params->channel_fixed;
1088
1089         if (params->ie) {
1090                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1091                                            GFP_KERNEL);
1092                 if (sdata->u.ibss.ie)
1093                         sdata->u.ibss.ie_len = params->ie_len;
1094         }
1095
1096         sdata->u.ibss.skb = skb;
1097         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1098         sdata->u.ibss.ibss_join_req = jiffies;
1099
1100         memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1101         sdata->u.ibss.ssid_len = params->ssid_len;
1102
1103         mutex_unlock(&sdata->u.ibss.mtx);
1104
1105         mutex_lock(&sdata->local->mtx);
1106         ieee80211_recalc_idle(sdata->local);
1107         mutex_unlock(&sdata->local->mtx);
1108
1109         /*
1110          * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1111          * reserved, but an HT STA shall protect HT transmissions as though
1112          * the HT Protection field were set to non-HT mixed mode.
1113          *
1114          * In an IBSS, the RIFS Mode field of the HT Operation element is
1115          * also reserved, but an HT STA shall operate as though this field
1116          * were set to 1.
1117          */
1118
1119         sdata->vif.bss_conf.ht_operation_mode |=
1120                   IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1121                 | IEEE80211_HT_PARAM_RIFS_MODE;
1122
1123         changed |= BSS_CHANGED_HT;
1124         ieee80211_bss_info_change_notify(sdata, changed);
1125
1126         sdata->smps_mode = IEEE80211_SMPS_OFF;
1127         sdata->needed_rx_chains = sdata->local->rx_chains;
1128
1129         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1130
1131         return 0;
1132 }
1133
1134 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1135 {
1136         struct sk_buff *skb;
1137         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1138         struct ieee80211_local *local = sdata->local;
1139         struct cfg80211_bss *cbss;
1140         u16 capability;
1141         int active_ibss;
1142         struct sta_info *sta;
1143
1144         mutex_lock(&sdata->u.ibss.mtx);
1145
1146         active_ibss = ieee80211_sta_active_ibss(sdata);
1147
1148         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1149                 capability = WLAN_CAPABILITY_IBSS;
1150
1151                 if (ifibss->privacy)
1152                         capability |= WLAN_CAPABILITY_PRIVACY;
1153
1154                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1155                                         ifibss->bssid, ifibss->ssid,
1156                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1157                                         WLAN_CAPABILITY_PRIVACY,
1158                                         capability);
1159
1160                 if (cbss) {
1161                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
1162                         cfg80211_put_bss(cbss);
1163                 }
1164         }
1165
1166         ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
1167         memset(ifibss->bssid, 0, ETH_ALEN);
1168         ifibss->ssid_len = 0;
1169
1170         sta_info_flush(sdata);
1171
1172         spin_lock_bh(&ifibss->incomplete_lock);
1173         while (!list_empty(&ifibss->incomplete_stations)) {
1174                 sta = list_first_entry(&ifibss->incomplete_stations,
1175                                        struct sta_info, list);
1176                 list_del(&sta->list);
1177                 spin_unlock_bh(&ifibss->incomplete_lock);
1178
1179                 sta_info_free(local, sta);
1180                 spin_lock_bh(&ifibss->incomplete_lock);
1181         }
1182         spin_unlock_bh(&ifibss->incomplete_lock);
1183
1184         netif_carrier_off(sdata->dev);
1185
1186         /* remove beacon */
1187         kfree(sdata->u.ibss.ie);
1188         skb = rcu_dereference_protected(sdata->u.ibss.presp,
1189                                         lockdep_is_held(&sdata->u.ibss.mtx));
1190         RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1191         sdata->vif.bss_conf.ibss_joined = false;
1192         sdata->vif.bss_conf.ibss_creator = false;
1193         sdata->vif.bss_conf.enable_beacon = false;
1194         clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
1195         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1196                                                 BSS_CHANGED_IBSS);
1197         synchronize_rcu();
1198         kfree_skb(skb);
1199
1200         skb_queue_purge(&sdata->skb_queue);
1201
1202         del_timer_sync(&sdata->u.ibss.timer);
1203
1204         mutex_unlock(&sdata->u.ibss.mtx);
1205
1206         mutex_lock(&local->mtx);
1207         ieee80211_recalc_idle(sdata->local);
1208         mutex_unlock(&local->mtx);
1209
1210         return 0;
1211 }