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