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 ieee80211_mgmt *mgmt;
  48         u8 *pos;
  49         struct ieee80211_supported_band *sband;
  50         struct cfg80211_bss *bss;
  51         u32 bss_change;
  52         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  53         struct cfg80211_chan_def chandef;
  54         struct beacon_data *presp;
  55         int frame_len;
  56
  57         lockdep_assert_held(&ifibss->mtx);
  58
  59         /* Reset own TSF to allow time synchronization work. */
  60         drv_reset_tsf(local, sdata);
  61
  62         if (!ether_addr_equal(ifibss->bssid, bssid))
  63                 sta_info_flush(sdata);
  64
  65         /* if merging, indicate to driver that we leave the old IBSS */
  66         if (sdata->vif.bss_conf.ibss_joined) {
  67                 sdata->vif.bss_conf.ibss_joined = false;
  68                 sdata->vif.bss_conf.ibss_creator = false;
  69                 sdata->vif.bss_conf.enable_beacon = false;
  70                 netif_carrier_off(sdata->dev);
  71                 ieee80211_bss_info_change_notify(sdata,
  72                                                  BSS_CHANGED_IBSS |
  73                                                  BSS_CHANGED_BEACON_ENABLED);
  74         }
  75
  76         presp = rcu_dereference_protected(ifibss->presp,
  77                                           lockdep_is_held(&ifibss->mtx));
  78         rcu_assign_pointer(ifibss->presp, NULL);
  79         if (presp)
  80                 kfree_rcu(presp, rcu_head);
  81
  82         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  83
  84         cfg80211_chandef_create(&chandef, chan, ifibss->channel_type);
  85         if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
  86                 chandef.width = NL80211_CHAN_WIDTH_20;
  87                 chandef.center_freq1 = chan->center_freq;
  88         }
  89
  90         ieee80211_vif_release_channel(sdata);
  91         if (ieee80211_vif_use_channel(sdata, &chandef,
  92                                       ifibss->fixed_channel ?
  93                                         IEEE80211_CHANCTX_SHARED :
  94                                         IEEE80211_CHANCTX_EXCLUSIVE)) {
  95                 sdata_info(sdata, "Failed to join IBSS, no channel context\n");
  96                 return;
  97         }
  98
  99         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 100
 101         sband = local->hw.wiphy->bands[chan->band];
 102
 103         /* Build IBSS probe response */
 104         frame_len = sizeof(struct ieee80211_hdr_3addr) +
 105                     12 /* struct ieee80211_mgmt.u.beacon */ +
 106                     2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
 107                     2 + 8 /* max Supported Rates */ +
 108                     3 /* max DS params */ +
 109                     4 /* IBSS params */ +
 110                     2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 111                     2 + sizeof(struct ieee80211_ht_cap) +
 112                     2 + sizeof(struct ieee80211_ht_operation) +
 113                     ifibss->ie_len;
 114         presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
 115         if (!presp)
 116                 return;
 117
 118         presp->head = (void *)(presp + 1);
 119
 120         mgmt = (void *) presp->head;
 121         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 122                                           IEEE80211_STYPE_PROBE_RESP);
 123         eth_broadcast_addr(mgmt->da);
 124         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 125         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 126         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 127         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 128         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 129
 130         pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
 131
 132         *pos++ = WLAN_EID_SSID;
 133         *pos++ = ifibss->ssid_len;
 134         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 135         pos += ifibss->ssid_len;
 136
 137         rates = min_t(int, 8, sband->n_bitrates);
 138         *pos++ = WLAN_EID_SUPP_RATES;
 139         *pos++ = rates;
 140         for (i = 0; i < rates; i++) {
 141                 int rate = sband->bitrates[i].bitrate;
 142                 u8 basic = 0;
 143                 if (basic_rates & BIT(i))
 144                         basic = 0x80;
 145                 *pos++ = basic | (u8) (rate / 5);
 146         }
 147
 148         if (sband->band == IEEE80211_BAND_2GHZ) {
 149                 *pos++ = WLAN_EID_DS_PARAMS;
 150                 *pos++ = 1;
 151                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 152         }
 153
 154         *pos++ = WLAN_EID_IBSS_PARAMS;
 155         *pos++ = 2;
 156         /* FIX: set ATIM window based on scan results */
 157         *pos++ = 0;
 158         *pos++ = 0;
 159
 160         if (sband->n_bitrates > 8) {
 161                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 162                 *pos++ = sband->n_bitrates - 8;
 163                 for (i = 8; i < sband->n_bitrates; i++) {
 164                         int rate = sband->bitrates[i].bitrate;
 165                         u8 basic = 0;
 166                         if (basic_rates & BIT(i))
 167                                 basic = 0x80;
 168                         *pos++ = basic | (u8) (rate / 5);
 169                 }
 170         }
 171
 172         if (ifibss->ie_len) {
 173                 memcpy(pos, ifibss->ie, ifibss->ie_len);
 174                 pos += ifibss->ie_len;
 175         }
 176
 177         /* add HT capability and information IEs */
 178         if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
 179             sband->ht_cap.ht_supported) {
 180                 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
 181                                                 sband->ht_cap.cap);
 182                 /*
 183                  * Note: According to 802.11n-2009 9.13.3.1, HT Protection
 184                  * field and RIFS Mode are reserved in IBSS mode, therefore
 185                  * keep them at 0
 186                  */
 187                 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
 188                                                  &chandef, 0);
 189         }
 190
 191         if (local->hw.queues >= IEEE80211_NUM_ACS) {
 192                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 193                 *pos++ = 7; /* len */
 194                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 195                 *pos++ = 0x50;
 196                 *pos++ = 0xf2;
 197                 *pos++ = 2; /* WME */
 198                 *pos++ = 0; /* WME info */
 199                 *pos++ = 1; /* WME ver */
 200                 *pos++ = 0; /* U-APSD no in use */
 201         }
 202
 203         presp->head_len = pos - presp->head;
 204         if (WARN_ON(presp->head_len > frame_len))
 205                 return;
 206
 207         rcu_assign_pointer(ifibss->presp, presp);
 208
 209         sdata->vif.bss_conf.enable_beacon = true;
 210         sdata->vif.bss_conf.beacon_int = beacon_int;
 211         sdata->vif.bss_conf.basic_rates = basic_rates;
 212         sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
 213         memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
 214         bss_change = BSS_CHANGED_BEACON_INT;
 215         bss_change |= ieee80211_reset_erp_info(sdata);
 216         bss_change |= BSS_CHANGED_BSSID;
 217         bss_change |= BSS_CHANGED_BEACON;
 218         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 219         bss_change |= BSS_CHANGED_BASIC_RATES;
 220         bss_change |= BSS_CHANGED_HT;
 221         bss_change |= BSS_CHANGED_IBSS;
 222         bss_change |= BSS_CHANGED_SSID;
 223
 224         /*
 225          * In 5 GHz/802.11a, we can always use short slot time.
 226          * (IEEE 802.11-2012 18.3.8.7)
 227          *
 228          * In 2.4GHz, we must always use long slots in IBSS for compatibility
 229          * reasons.
 230          * (IEEE 802.11-2012 19.4.5)
 231          *
 232          * HT follows these specifications (IEEE 802.11-2012 20.3.18)
 233          */
 234         sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
 235         bss_change |= BSS_CHANGED_ERP_SLOT;
 236
 237         sdata->vif.bss_conf.ibss_joined = true;
 238         sdata->vif.bss_conf.ibss_creator = creator;
 239         ieee80211_bss_info_change_notify(sdata, bss_change);
 240
 241         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 242
 243         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 244         mod_timer(&ifibss->timer,
 245                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 246
 247         bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
 248                                         mgmt, presp->head_len, 0, GFP_KERNEL);
 249         cfg80211_put_bss(local->hw.wiphy, bss);
 250         netif_carrier_on(sdata->dev);
 251         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 252 }
 253
 254 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 255                                     struct ieee80211_bss *bss)
 256 {
 257         struct cfg80211_bss *cbss =
 258                 container_of((void *)bss, struct cfg80211_bss, priv);
 259         struct ieee80211_supported_band *sband;
 260         u32 basic_rates;
 261         int i, j;
 262         u16 beacon_int = cbss->beacon_interval;
 263         const struct cfg80211_bss_ies *ies;
 264         u64 tsf;
 265
 266         lockdep_assert_held(&sdata->u.ibss.mtx);
 267
 268         if (beacon_int < 10)
 269                 beacon_int = 10;
 270
 271         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 272
 273         basic_rates = 0;
 274
 275         for (i = 0; i < bss->supp_rates_len; i++) {
 276                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 277                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 278
 279                 for (j = 0; j < sband->n_bitrates; j++) {
 280                         if (sband->bitrates[j].bitrate == rate) {
 281                                 if (is_basic)
 282                                         basic_rates |= BIT(j);
 283                                 break;
 284                         }
 285                 }
 286         }
 287
 288         rcu_read_lock();
 289         ies = rcu_dereference(cbss->ies);
 290         tsf = ies->tsf;
 291         rcu_read_unlock();
 292
 293         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 294                                   beacon_int,
 295                                   cbss->channel,
 296                                   basic_rates,
 297                                   cbss->capability,
 298                                   tsf, false);
 299 }
 300
 301 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
 302                                                   bool auth)
 303         __acquires(RCU)
 304 {
 305         struct ieee80211_sub_if_data *sdata = sta->sdata;
 306         u8 addr[ETH_ALEN];
 307
 308         memcpy(addr, sta->sta.addr, ETH_ALEN);
 309
 310         ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
 311
 312         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 313         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 314         /* authorize the station only if the network is not RSN protected. If
 315          * not wait for the userspace to authorize it */
 316         if (!sta->sdata->u.ibss.control_port)
 317                 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 318
 319         rate_control_rate_init(sta);
 320
 321         /* If it fails, maybe we raced another insertion? */
 322         if (sta_info_insert_rcu(sta))
 323                 return sta_info_get(sdata, addr);
 324         if (auth && !sdata->u.ibss.auth_frame_registrations) {
 325                 ibss_dbg(sdata,
 326                          "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
 327                          sdata->vif.addr, addr, sdata->u.ibss.bssid);
 328                 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
 329                                     addr, sdata->u.ibss.bssid, NULL, 0, 0, 0);
 330         }
 331         return sta;
 332 }
 333
 334 static struct sta_info *
 335 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 336                        const u8 *bssid, const u8 *addr,
 337                        u32 supp_rates, bool auth)
 338         __acquires(RCU)
 339 {
 340         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 341         struct ieee80211_local *local = sdata->local;
 342         struct sta_info *sta;
 343         struct ieee80211_chanctx_conf *chanctx_conf;
 344         int band;
 345
 346         /*
 347          * XXX: Consider removing the least recently used entry and
 348          *      allow new one to be added.
 349          */
 350         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 351                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 352                                     sdata->name, addr);
 353                 rcu_read_lock();
 354                 return NULL;
 355         }
 356
 357         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
 358                 rcu_read_lock();
 359                 return NULL;
 360         }
 361
 362         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
 363                 rcu_read_lock();
 364                 return NULL;
 365         }
 366
 367         rcu_read_lock();
 368         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 369         if (WARN_ON_ONCE(!chanctx_conf))
 370                 return NULL;
 371         band = chanctx_conf->def.chan->band;
 372         rcu_read_unlock();
 373
 374         sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 375         if (!sta) {
 376                 rcu_read_lock();
 377                 return NULL;
 378         }
 379
 380         sta->last_rx = jiffies;
 381
 382         /* make sure mandatory rates are always added */
 383         sta->sta.supp_rates[band] = supp_rates |
 384                         ieee80211_mandatory_rates(local, band);
 385
 386         return ieee80211_ibss_finish_sta(sta, auth);
 387 }
 388
 389 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
 390                                           struct ieee80211_mgmt *mgmt,
 391                                           size_t len)
 392 {
 393         u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
 394
 395         if (len < IEEE80211_DEAUTH_FRAME_LEN)
 396                 return;
 397
 398         ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
 399                  mgmt->sa, mgmt->da, mgmt->bssid, reason);
 400         sta_info_destroy_addr(sdata, mgmt->sa);
 401 }
 402
 403 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
 404                                         struct ieee80211_mgmt *mgmt,
 405                                         size_t len)
 406 {
 407         u16 auth_alg, auth_transaction;
 408         struct sta_info *sta;
 409         u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
 410
 411         lockdep_assert_held(&sdata->u.ibss.mtx);
 412
 413         if (len < 24 + 6)
 414                 return;
 415
 416         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
 417         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
 418
 419         ibss_dbg(sdata,
 420                  "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
 421                  mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
 422
 423         if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
 424                 return;
 425
 426         sta_info_destroy_addr(sdata, mgmt->sa);
 427         sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
 428         rcu_read_unlock();
 429
 430         /*
 431          * if we have any problem in allocating the new station, we reply with a
 432          * DEAUTH frame to tell the other end that we had a problem
 433          */
 434         if (!sta) {
 435                 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
 436                                                IEEE80211_STYPE_DEAUTH,
 437                                                WLAN_REASON_UNSPECIFIED, true,
 438                                                deauth_frame_buf);
 439                 return;
 440         }
 441
 442         /*
 443          * IEEE 802.11 standard does not require authentication in IBSS
 444          * networks and most implementations do not seem to use it.
 445          * However, try to reply to authentication attempts if someone
 446          * has actually implemented this.
 447          */
 448         ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
 449                             mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
 450 }
 451
 452 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 453                                   struct ieee80211_mgmt *mgmt, size_t len,
 454                                   struct ieee80211_rx_status *rx_status,
 455                                   struct ieee802_11_elems *elems)
 456 {
 457         struct ieee80211_local *local = sdata->local;
 458         int freq;
 459         struct cfg80211_bss *cbss;
 460         struct ieee80211_bss *bss;
 461         struct sta_info *sta;
 462         struct ieee80211_channel *channel;
 463         u64 beacon_timestamp, rx_timestamp;
 464         u32 supp_rates = 0;
 465         enum ieee80211_band band = rx_status->band;
 466         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 467         bool rates_updated = false;
 468
 469         if (elems->ds_params)
 470                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
 471                                                       band);
 472         else
 473                 freq = rx_status->freq;
 474
 475         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 476
 477         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 478                 return;
 479
 480         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 481             ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
 482
 483                 rcu_read_lock();
 484                 sta = sta_info_get(sdata, mgmt->sa);
 485
 486                 if (elems->supp_rates) {
 487                         supp_rates = ieee80211_sta_get_rates(local, elems,
 488                                                              band, NULL);
 489                         if (sta) {
 490                                 u32 prev_rates;
 491
 492                                 prev_rates = sta->sta.supp_rates[band];
 493                                 /* make sure mandatory rates are always added */
 494                                 sta->sta.supp_rates[band] = supp_rates |
 495                                         ieee80211_mandatory_rates(local, band);
 496
 497                                 if (sta->sta.supp_rates[band] != prev_rates) {
 498                                         ibss_dbg(sdata,
 499                                                  "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
 500                                                  sta->sta.addr, prev_rates,
 501                                                  sta->sta.supp_rates[band]);
 502                                         rates_updated = true;
 503                                 }
 504                         } else {
 505                                 rcu_read_unlock();
 506                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
 507                                                 mgmt->sa, supp_rates, true);
 508                         }
 509                 }
 510
 511                 if (sta && elems->wmm_info)
 512                         set_sta_flag(sta, WLAN_STA_WME);
 513
 514                 if (sta && elems->ht_operation && elems->ht_cap_elem &&
 515                     sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
 516                         /* we both use HT */
 517                         struct ieee80211_ht_cap htcap_ie;
 518                         struct cfg80211_chan_def chandef;
 519
 520                         ieee80211_ht_oper_to_chandef(channel,
 521                                                      elems->ht_operation,
 522                                                      &chandef);
 523
 524                         memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
 525
 526                         /*
 527                          * fall back to HT20 if we don't use or use
 528                          * the other extension channel
 529                          */
 530                         if (cfg80211_get_chandef_type(&chandef) !=
 531                                                 sdata->u.ibss.channel_type)
 532                                 htcap_ie.cap_info &=
 533                                         cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
 534
 535                         rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
 536                                                 sdata, sband, &htcap_ie, sta);
 537                 }
 538
 539                 if (sta && rates_updated) {
 540                         drv_sta_rc_update(local, sdata, &sta->sta,
 541                                           IEEE80211_RC_SUPP_RATES_CHANGED);
 542                         rate_control_rate_init(sta);
 543                 }
 544
 545                 rcu_read_unlock();
 546         }
 547
 548         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 549                                         channel);
 550         if (!bss)
 551                 return;
 552
 553         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 554
 555         /* same for beacon and probe response */
 556         beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
 557
 558         /* check if we need to merge IBSS */
 559
 560         /* we use a fixed BSSID */
 561         if (sdata->u.ibss.fixed_bssid)
 562                 goto put_bss;
 563
 564         /* not an IBSS */
 565         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 566                 goto put_bss;
 567
 568         /* different channel */
 569         if (sdata->u.ibss.fixed_channel &&
 570             sdata->u.ibss.channel != cbss->channel)
 571                 goto put_bss;
 572
 573         /* different SSID */
 574         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 575             memcmp(elems->ssid, sdata->u.ibss.ssid,
 576                                 sdata->u.ibss.ssid_len))
 577                 goto put_bss;
 578
 579         /* same BSSID */
 580         if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
 581                 goto put_bss;
 582
 583         if (ieee80211_have_rx_timestamp(rx_status)) {
 584                 /* time when timestamp field was received */
 585                 rx_timestamp =
 586                         ieee80211_calculate_rx_timestamp(local, rx_status,
 587                                                          len + FCS_LEN, 24);
 588         } else {
 589                 /*
 590                  * second best option: get current TSF
 591                  * (will return -1 if not supported)
 592                  */
 593                 rx_timestamp = drv_get_tsf(local, sdata);
 594         }
 595
 596         ibss_dbg(sdata,
 597                  "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 598                  mgmt->sa, mgmt->bssid,
 599                  (unsigned long long)rx_timestamp,
 600                  (unsigned long long)beacon_timestamp,
 601                  (unsigned long long)(rx_timestamp - beacon_timestamp),
 602                  jiffies);
 603
 604         if (beacon_timestamp > rx_timestamp) {
 605                 ibss_dbg(sdata,
 606                          "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
 607                          mgmt->bssid);
 608                 ieee80211_sta_join_ibss(sdata, bss);
 609                 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
 610                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 611                                        supp_rates, true);
 612                 rcu_read_unlock();
 613         }
 614
 615  put_bss:
 616         ieee80211_rx_bss_put(local, bss);
 617 }
 618
 619 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
 620                               const u8 *bssid, const u8 *addr,
 621                               u32 supp_rates)
 622 {
 623         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 624         struct ieee80211_local *local = sdata->local;
 625         struct sta_info *sta;
 626         struct ieee80211_chanctx_conf *chanctx_conf;
 627         int band;
 628
 629         /*
 630          * XXX: Consider removing the least recently used entry and
 631          *      allow new one to be added.
 632          */
 633         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 634                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 635                                     sdata->name, addr);
 636                 return;
 637         }
 638
 639         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 640                 return;
 641
 642         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
 643                 return;
 644
 645         rcu_read_lock();
 646         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 647         if (WARN_ON_ONCE(!chanctx_conf)) {
 648                 rcu_read_unlock();
 649                 return;
 650         }
 651         band = chanctx_conf->def.chan->band;
 652         rcu_read_unlock();
 653
 654         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 655         if (!sta)
 656                 return;
 657
 658         sta->last_rx = jiffies;
 659
 660         /* make sure mandatory rates are always added */
 661         sta->sta.supp_rates[band] = supp_rates |
 662                         ieee80211_mandatory_rates(local, band);
 663
 664         spin_lock(&ifibss->incomplete_lock);
 665         list_add(&sta->list, &ifibss->incomplete_stations);
 666         spin_unlock(&ifibss->incomplete_lock);
 667         ieee80211_queue_work(&local->hw, &sdata->work);
 668 }
 669
 670 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 671 {
 672         struct ieee80211_local *local = sdata->local;
 673         int active = 0;
 674         struct sta_info *sta;
 675
 676         lockdep_assert_held(&sdata->u.ibss.mtx);
 677
 678         rcu_read_lock();
 679
 680         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 681                 if (sta->sdata == sdata &&
 682                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 683                                jiffies)) {
 684                         active++;
 685                         break;
 686                 }
 687         }
 688
 689         rcu_read_unlock();
 690
 691         return active;
 692 }
 693
 694 /*
 695  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 696  */
 697
 698 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 699 {
 700         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 701
 702         lockdep_assert_held(&ifibss->mtx);
 703
 704         mod_timer(&ifibss->timer,
 705                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 706
 707         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 708
 709         if (time_before(jiffies, ifibss->last_scan_completed +
 710                        IEEE80211_IBSS_MERGE_INTERVAL))
 711                 return;
 712
 713         if (ieee80211_sta_active_ibss(sdata))
 714                 return;
 715
 716         if (ifibss->fixed_channel)
 717                 return;
 718
 719         sdata_info(sdata,
 720                    "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
 721
 722         ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
 723                                     NULL);
 724 }
 725
 726 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 727 {
 728         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 729         u8 bssid[ETH_ALEN];
 730         u16 capability;
 731         int i;
 732
 733         lockdep_assert_held(&ifibss->mtx);
 734
 735         if (ifibss->fixed_bssid) {
 736                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 737         } else {
 738                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 739                  * own MAC address to make sure that devices that do not have proper
 740                  * random number generator get different BSSID. */
 741                 get_random_bytes(bssid, ETH_ALEN);
 742                 for (i = 0; i < ETH_ALEN; i++)
 743                         bssid[i] ^= sdata->vif.addr[i];
 744                 bssid[0] &= ~0x01;
 745                 bssid[0] |= 0x02;
 746         }
 747
 748         sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
 749
 750         capability = WLAN_CAPABILITY_IBSS;
 751
 752         if (ifibss->privacy)
 753                 capability |= WLAN_CAPABILITY_PRIVACY;
 754         else
 755                 sdata->drop_unencrypted = 0;
 756
 757         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 758                                   ifibss->channel, ifibss->basic_rates,
 759                                   capability, 0, true);
 760 }
 761
 762 /*
 763  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 764  */
 765
 766 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 767 {
 768         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 769         struct ieee80211_local *local = sdata->local;
 770         struct cfg80211_bss *cbss;
 771         struct ieee80211_channel *chan = NULL;
 772         const u8 *bssid = NULL;
 773         int active_ibss;
 774         u16 capability;
 775
 776         lockdep_assert_held(&ifibss->mtx);
 777
 778         active_ibss = ieee80211_sta_active_ibss(sdata);
 779         ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
 780
 781         if (active_ibss)
 782                 return;
 783
 784         capability = WLAN_CAPABILITY_IBSS;
 785         if (ifibss->privacy)
 786                 capability |= WLAN_CAPABILITY_PRIVACY;
 787         if (ifibss->fixed_bssid)
 788                 bssid = ifibss->bssid;
 789         if (ifibss->fixed_channel)
 790                 chan = ifibss->channel;
 791         if (!is_zero_ether_addr(ifibss->bssid))
 792                 bssid = ifibss->bssid;
 793         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 794                                 ifibss->ssid, ifibss->ssid_len,
 795                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 796                                 capability);
 797
 798         if (cbss) {
 799                 struct ieee80211_bss *bss;
 800
 801                 bss = (void *)cbss->priv;
 802                 ibss_dbg(sdata,
 803                          "sta_find_ibss: selected %pM current %pM\n",
 804                          cbss->bssid, ifibss->bssid);
 805                 sdata_info(sdata,
 806                            "Selected IBSS BSSID %pM based on configured SSID\n",
 807                            cbss->bssid);
 808
 809                 ieee80211_sta_join_ibss(sdata, bss);
 810                 ieee80211_rx_bss_put(local, bss);
 811                 return;
 812         }
 813
 814         ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
 815
 816         /* Selected IBSS not found in current scan results - try to scan */
 817         if (time_after(jiffies, ifibss->last_scan_completed +
 818                                         IEEE80211_SCAN_INTERVAL)) {
 819                 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 820
 821                 ieee80211_request_ibss_scan(sdata, ifibss->ssid,
 822                                             ifibss->ssid_len, chan);
 823         } else {
 824                 int interval = IEEE80211_SCAN_INTERVAL;
 825
 826                 if (time_after(jiffies, ifibss->ibss_join_req +
 827                                IEEE80211_IBSS_JOIN_TIMEOUT))
 828                         ieee80211_sta_create_ibss(sdata);
 829
 830                 mod_timer(&ifibss->timer,
 831                           round_jiffies(jiffies + interval));
 832         }
 833 }
 834
 835 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 836                                         struct sk_buff *req)
 837 {
 838         struct ieee80211_mgmt *mgmt = (void *)req->data;
 839         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 840         struct ieee80211_local *local = sdata->local;
 841         int tx_last_beacon, len = req->len;
 842         struct sk_buff *skb;
 843         struct beacon_data *presp;
 844         u8 *pos, *end;
 845
 846         lockdep_assert_held(&ifibss->mtx);
 847
 848         presp = rcu_dereference_protected(ifibss->presp,
 849                                           lockdep_is_held(&ifibss->mtx));
 850
 851         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 852             len < 24 + 2 || !presp)
 853                 return;
 854
 855         tx_last_beacon = drv_tx_last_beacon(local);
 856
 857         ibss_dbg(sdata,
 858                  "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
 859                  mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
 860
 861         if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
 862                 return;
 863
 864         if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
 865             !is_broadcast_ether_addr(mgmt->bssid))
 866                 return;
 867
 868         end = ((u8 *) mgmt) + len;
 869         pos = mgmt->u.probe_req.variable;
 870         if (pos[0] != WLAN_EID_SSID ||
 871             pos + 2 + pos[1] > end) {
 872                 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
 873                          mgmt->sa);
 874                 return;
 875         }
 876         if (pos[1] != 0 &&
 877             (pos[1] != ifibss->ssid_len ||
 878              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 879                 /* Ignore ProbeReq for foreign SSID */
 880                 return;
 881         }
 882
 883         /* Reply with ProbeResp */
 884         skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
 885         if (!skb)
 886                 return;
 887
 888         skb_reserve(skb, local->tx_headroom);
 889         memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
 890
 891         memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
 892         ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
 893         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 894         ieee80211_tx_skb(sdata, skb);
 895 }
 896
 897 static
 898 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
 899                                     struct ieee80211_mgmt *mgmt, size_t len,
 900                                     struct ieee80211_rx_status *rx_status)
 901 {
 902         size_t baselen;
 903         struct ieee802_11_elems elems;
 904
 905         BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
 906                      offsetof(typeof(mgmt->u.beacon), variable));
 907
 908         /*
 909          * either beacon or probe_resp but the variable field is at the
 910          * same offset
 911          */
 912         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 913         if (baselen > len)
 914                 return;
 915
 916         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 917                                false, &elems);
 918
 919         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
 920 }
 921
 922 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 923                                    struct sk_buff *skb)
 924 {
 925         struct ieee80211_rx_status *rx_status;
 926         struct ieee80211_mgmt *mgmt;
 927         u16 fc;
 928
 929         rx_status = IEEE80211_SKB_RXCB(skb);
 930         mgmt = (struct ieee80211_mgmt *) skb->data;
 931         fc = le16_to_cpu(mgmt->frame_control);
 932
 933         mutex_lock(&sdata->u.ibss.mtx);
 934
 935         if (!sdata->u.ibss.ssid_len)
 936                 goto mgmt_out; /* not ready to merge yet */
 937
 938         switch (fc & IEEE80211_FCTL_STYPE) {
 939         case IEEE80211_STYPE_PROBE_REQ:
 940                 ieee80211_rx_mgmt_probe_req(sdata, skb);
 941                 break;
 942         case IEEE80211_STYPE_PROBE_RESP:
 943         case IEEE80211_STYPE_BEACON:
 944                 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
 945                                                rx_status);
 946                 break;
 947         case IEEE80211_STYPE_AUTH:
 948                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 949                 break;
 950         case IEEE80211_STYPE_DEAUTH:
 951                 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
 952                 break;
 953         }
 954
 955  mgmt_out:
 956         mutex_unlock(&sdata->u.ibss.mtx);
 957 }
 958
 959 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 960 {
 961         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 962         struct sta_info *sta;
 963
 964         mutex_lock(&ifibss->mtx);
 965
 966         /*
 967          * Work could be scheduled after scan or similar
 968          * when we aren't even joined (or trying) with a
 969          * network.
 970          */
 971         if (!ifibss->ssid_len)
 972                 goto out;
 973
 974         spin_lock_bh(&ifibss->incomplete_lock);
 975         while (!list_empty(&ifibss->incomplete_stations)) {
 976                 sta = list_first_entry(&ifibss->incomplete_stations,
 977                                        struct sta_info, list);
 978                 list_del(&sta->list);
 979                 spin_unlock_bh(&ifibss->incomplete_lock);
 980
 981                 ieee80211_ibss_finish_sta(sta, true);
 982                 rcu_read_unlock();
 983                 spin_lock_bh(&ifibss->incomplete_lock);
 984         }
 985         spin_unlock_bh(&ifibss->incomplete_lock);
 986
 987         switch (ifibss->state) {
 988         case IEEE80211_IBSS_MLME_SEARCH:
 989                 ieee80211_sta_find_ibss(sdata);
 990                 break;
 991         case IEEE80211_IBSS_MLME_JOINED:
 992                 ieee80211_sta_merge_ibss(sdata);
 993                 break;
 994         default:
 995                 WARN_ON(1);
 996                 break;
 997         }
 998
 999  out:
1000         mutex_unlock(&ifibss->mtx);
1001 }
1002
1003 static void ieee80211_ibss_timer(unsigned long data)
1004 {
1005         struct ieee80211_sub_if_data *sdata =
1006                 (struct ieee80211_sub_if_data *) data;
1007
1008         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1009 }
1010
1011 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1012 {
1013         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1014
1015         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1016                     (unsigned long) sdata);
1017         mutex_init(&ifibss->mtx);
1018         INIT_LIST_HEAD(&ifibss->incomplete_stations);
1019         spin_lock_init(&ifibss->incomplete_lock);
1020 }
1021
1022 /* scan finished notification */
1023 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1024 {
1025         struct ieee80211_sub_if_data *sdata;
1026
1027         mutex_lock(&local->iflist_mtx);
1028         list_for_each_entry(sdata, &local->interfaces, list) {
1029                 if (!ieee80211_sdata_running(sdata))
1030                         continue;
1031                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1032                         continue;
1033                 sdata->u.ibss.last_scan_completed = jiffies;
1034                 ieee80211_queue_work(&local->hw, &sdata->work);
1035         }
1036         mutex_unlock(&local->iflist_mtx);
1037 }
1038
1039 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1040                         struct cfg80211_ibss_params *params)
1041 {
1042         u32 changed = 0;
1043
1044         mutex_lock(&sdata->u.ibss.mtx);
1045
1046         if (params->bssid) {
1047                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1048                 sdata->u.ibss.fixed_bssid = true;
1049         } else
1050                 sdata->u.ibss.fixed_bssid = false;
1051
1052         sdata->u.ibss.privacy = params->privacy;
1053         sdata->u.ibss.control_port = params->control_port;
1054         sdata->u.ibss.basic_rates = params->basic_rates;
1055         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1056                sizeof(params->mcast_rate));
1057
1058         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1059
1060         sdata->u.ibss.channel = params->chandef.chan;
1061         sdata->u.ibss.channel_type =
1062                 cfg80211_get_chandef_type(&params->chandef);
1063         sdata->u.ibss.fixed_channel = params->channel_fixed;
1064
1065         if (params->ie) {
1066                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1067                                            GFP_KERNEL);
1068                 if (sdata->u.ibss.ie)
1069                         sdata->u.ibss.ie_len = params->ie_len;
1070         }
1071
1072         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1073         sdata->u.ibss.ibss_join_req = jiffies;
1074
1075         memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1076         sdata->u.ibss.ssid_len = params->ssid_len;
1077
1078         mutex_unlock(&sdata->u.ibss.mtx);
1079
1080         /*
1081          * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1082          * reserved, but an HT STA shall protect HT transmissions as though
1083          * the HT Protection field were set to non-HT mixed mode.
1084          *
1085          * In an IBSS, the RIFS Mode field of the HT Operation element is
1086          * also reserved, but an HT STA shall operate as though this field
1087          * were set to 1.
1088          */
1089
1090         sdata->vif.bss_conf.ht_operation_mode |=
1091                   IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1092                 | IEEE80211_HT_PARAM_RIFS_MODE;
1093
1094         changed |= BSS_CHANGED_HT;
1095         ieee80211_bss_info_change_notify(sdata, changed);
1096
1097         sdata->smps_mode = IEEE80211_SMPS_OFF;
1098         sdata->needed_rx_chains = sdata->local->rx_chains;
1099
1100         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1101
1102         return 0;
1103 }
1104
1105 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1106 {
1107         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1108         struct ieee80211_local *local = sdata->local;
1109         struct cfg80211_bss *cbss;
1110         u16 capability;
1111         int active_ibss;
1112         struct sta_info *sta;
1113         struct beacon_data *presp;
1114
1115         mutex_lock(&sdata->u.ibss.mtx);
1116
1117         active_ibss = ieee80211_sta_active_ibss(sdata);
1118
1119         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1120                 capability = WLAN_CAPABILITY_IBSS;
1121
1122                 if (ifibss->privacy)
1123                         capability |= WLAN_CAPABILITY_PRIVACY;
1124
1125                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1126                                         ifibss->bssid, ifibss->ssid,
1127                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1128                                         WLAN_CAPABILITY_PRIVACY,
1129                                         capability);
1130
1131                 if (cbss) {
1132                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
1133                         cfg80211_put_bss(local->hw.wiphy, cbss);
1134                 }
1135         }
1136
1137         ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
1138         memset(ifibss->bssid, 0, ETH_ALEN);
1139         ifibss->ssid_len = 0;
1140
1141         sta_info_flush(sdata);
1142
1143         spin_lock_bh(&ifibss->incomplete_lock);
1144         while (!list_empty(&ifibss->incomplete_stations)) {
1145                 sta = list_first_entry(&ifibss->incomplete_stations,
1146                                        struct sta_info, list);
1147                 list_del(&sta->list);
1148                 spin_unlock_bh(&ifibss->incomplete_lock);
1149
1150                 sta_info_free(local, sta);
1151                 spin_lock_bh(&ifibss->incomplete_lock);
1152         }
1153         spin_unlock_bh(&ifibss->incomplete_lock);
1154
1155         netif_carrier_off(sdata->dev);
1156
1157         /* remove beacon */
1158         kfree(sdata->u.ibss.ie);
1159         presp = rcu_dereference_protected(ifibss->presp,
1160                                           lockdep_is_held(&sdata->u.ibss.mtx));
1161         RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1162         sdata->vif.bss_conf.ibss_joined = false;
1163         sdata->vif.bss_conf.ibss_creator = false;
1164         sdata->vif.bss_conf.enable_beacon = false;
1165         sdata->vif.bss_conf.ssid_len = 0;
1166         clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
1167         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1168                                                 BSS_CHANGED_IBSS);
1169         ieee80211_vif_release_channel(sdata);
1170         synchronize_rcu();
1171         kfree(presp);
1172
1173         skb_queue_purge(&sdata->skb_queue);
1174
1175         del_timer_sync(&sdata->u.ibss.timer);
1176
1177         mutex_unlock(&sdata->u.ibss.mtx);
1178
1179         return 0;
1180 }