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 {
  43         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  44         struct ieee80211_local *local = sdata->local;
  45         int rates, i;
  46         struct sk_buff *skb;
  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         enum nl80211_channel_type channel_type;
  54
  55         lockdep_assert_held(&ifibss->mtx);
  56
  57         /* Reset own TSF to allow time synchronization work. */
  58         drv_reset_tsf(local, sdata);
  59
  60         skb = ifibss->skb;
  61         RCU_INIT_POINTER(ifibss->presp, NULL);
  62         synchronize_rcu();
  63         skb->data = skb->head;
  64         skb->len = 0;
  65         skb_reset_tail_pointer(skb);
  66         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  67
  68         if (!ether_addr_equal(ifibss->bssid, bssid))
  69                 sta_info_flush(sdata->local, sdata);
  70
  71         /* if merging, indicate to driver that we leave the old IBSS */
  72         if (sdata->vif.bss_conf.ibss_joined) {
  73                 sdata->vif.bss_conf.ibss_joined = false;
  74                 netif_carrier_off(sdata->dev);
  75                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
  76         }
  77
  78         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  79
  80         channel_type = ifibss->channel_type;
  81         if (!cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
  82                 channel_type = NL80211_CHAN_HT20;
  83
  84         ieee80211_vif_release_channel(sdata);
  85         if (ieee80211_vif_use_channel(sdata, chan, channel_type,
  86                                       ifibss->fixed_channel ?
  87                                         IEEE80211_CHANCTX_SHARED :
  88                                         IEEE80211_CHANCTX_EXCLUSIVE)) {
  89                 sdata_info(sdata, "Failed to join IBSS, no channel context\n");
  90                 return;
  91         }
  92
  93         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  94
  95         sband = local->hw.wiphy->bands[chan->band];
  96
  97         /* build supported rates array */
  98         pos = supp_rates;
  99         for (i = 0; i < sband->n_bitrates; i++) {
 100                 int rate = sband->bitrates[i].bitrate;
 101                 u8 basic = 0;
 102                 if (basic_rates & BIT(i))
 103                         basic = 0x80;
 104                 *pos++ = basic | (u8) (rate / 5);
 105         }
 106
 107         /* Build IBSS probe response */
 108         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 109         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 110         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 111                                           IEEE80211_STYPE_PROBE_RESP);
 112         eth_broadcast_addr(mgmt->da);
 113         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 114         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 115         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 116         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 117         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 118
 119         pos = skb_put(skb, 2 + ifibss->ssid_len);
 120         *pos++ = WLAN_EID_SSID;
 121         *pos++ = ifibss->ssid_len;
 122         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 123
 124         rates = sband->n_bitrates;
 125         if (rates > 8)
 126                 rates = 8;
 127         pos = skb_put(skb, 2 + rates);
 128         *pos++ = WLAN_EID_SUPP_RATES;
 129         *pos++ = rates;
 130         memcpy(pos, supp_rates, rates);
 131
 132         if (sband->band == IEEE80211_BAND_2GHZ) {
 133                 pos = skb_put(skb, 2 + 1);
 134                 *pos++ = WLAN_EID_DS_PARAMS;
 135                 *pos++ = 1;
 136                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 137         }
 138
 139         pos = skb_put(skb, 2 + 2);
 140         *pos++ = WLAN_EID_IBSS_PARAMS;
 141         *pos++ = 2;
 142         /* FIX: set ATIM window based on scan results */
 143         *pos++ = 0;
 144         *pos++ = 0;
 145
 146         if (sband->n_bitrates > 8) {
 147                 rates = sband->n_bitrates - 8;
 148                 pos = skb_put(skb, 2 + rates);
 149                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 150                 *pos++ = rates;
 151                 memcpy(pos, &supp_rates[8], rates);
 152         }
 153
 154         if (ifibss->ie_len)
 155                 memcpy(skb_put(skb, ifibss->ie_len),
 156                        ifibss->ie, ifibss->ie_len);
 157
 158         /* add HT capability and information IEs */
 159         if (channel_type && sband->ht_cap.ht_supported) {
 160                 pos = skb_put(skb, 4 +
 161                                    sizeof(struct ieee80211_ht_cap) +
 162                                    sizeof(struct ieee80211_ht_operation));
 163                 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
 164                                                 sband->ht_cap.cap);
 165                 /*
 166                  * Note: According to 802.11n-2009 9.13.3.1, HT Protection
 167                  * field and RIFS Mode are reserved in IBSS mode, therefore
 168                  * keep them at 0
 169                  */
 170                 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
 171                                                  chan, channel_type, 0);
 172         }
 173
 174         if (local->hw.queues >= IEEE80211_NUM_ACS) {
 175                 pos = skb_put(skb, 9);
 176                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 177                 *pos++ = 7; /* len */
 178                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 179                 *pos++ = 0x50;
 180                 *pos++ = 0xf2;
 181                 *pos++ = 2; /* WME */
 182                 *pos++ = 0; /* WME info */
 183                 *pos++ = 1; /* WME ver */
 184                 *pos++ = 0; /* U-APSD no in use */
 185         }
 186
 187         rcu_assign_pointer(ifibss->presp, skb);
 188
 189         sdata->vif.bss_conf.beacon_int = beacon_int;
 190         sdata->vif.bss_conf.basic_rates = basic_rates;
 191         bss_change = BSS_CHANGED_BEACON_INT;
 192         bss_change |= ieee80211_reset_erp_info(sdata);
 193         bss_change |= BSS_CHANGED_BSSID;
 194         bss_change |= BSS_CHANGED_BEACON;
 195         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 196         bss_change |= BSS_CHANGED_BASIC_RATES;
 197         bss_change |= BSS_CHANGED_HT;
 198         bss_change |= BSS_CHANGED_IBSS;
 199         sdata->vif.bss_conf.ibss_joined = true;
 200         ieee80211_bss_info_change_notify(sdata, bss_change);
 201
 202         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 203
 204         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 205         mod_timer(&ifibss->timer,
 206                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 207
 208         bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
 209                                         mgmt, skb->len, 0, GFP_KERNEL);
 210         cfg80211_put_bss(bss);
 211         netif_carrier_on(sdata->dev);
 212         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 213 }
 214
 215 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 216                                     struct ieee80211_bss *bss)
 217 {
 218         struct cfg80211_bss *cbss =
 219                 container_of((void *)bss, struct cfg80211_bss, priv);
 220         struct ieee80211_supported_band *sband;
 221         u32 basic_rates;
 222         int i, j;
 223         u16 beacon_int = cbss->beacon_interval;
 224
 225         lockdep_assert_held(&sdata->u.ibss.mtx);
 226
 227         if (beacon_int < 10)
 228                 beacon_int = 10;
 229
 230         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 231
 232         basic_rates = 0;
 233
 234         for (i = 0; i < bss->supp_rates_len; i++) {
 235                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 236                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 237
 238                 for (j = 0; j < sband->n_bitrates; j++) {
 239                         if (sband->bitrates[j].bitrate == rate) {
 240                                 if (is_basic)
 241                                         basic_rates |= BIT(j);
 242                                 break;
 243                         }
 244                 }
 245         }
 246
 247         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 248                                   beacon_int,
 249                                   cbss->channel,
 250                                   basic_rates,
 251                                   cbss->capability,
 252                                   cbss->tsf);
 253 }
 254
 255 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
 256                                                   bool auth)
 257         __acquires(RCU)
 258 {
 259         struct ieee80211_sub_if_data *sdata = sta->sdata;
 260         u8 addr[ETH_ALEN];
 261
 262         memcpy(addr, sta->sta.addr, ETH_ALEN);
 263
 264         ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
 265
 266         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 267         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 268         /* authorize the station only if the network is not RSN protected. If
 269          * not wait for the userspace to authorize it */
 270         if (!sta->sdata->u.ibss.control_port)
 271                 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 272
 273         rate_control_rate_init(sta);
 274
 275         /* If it fails, maybe we raced another insertion? */
 276         if (sta_info_insert_rcu(sta))
 277                 return sta_info_get(sdata, addr);
 278         if (auth && !sdata->u.ibss.auth_frame_registrations) {
 279                 ibss_dbg(sdata,
 280                          "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
 281                          sdata->vif.addr, addr, sdata->u.ibss.bssid);
 282                 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
 283                                     addr, sdata->u.ibss.bssid, NULL, 0, 0);
 284         }
 285         return sta;
 286 }
 287
 288 static struct sta_info *
 289 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 290                        const u8 *bssid, const u8 *addr,
 291                        u32 supp_rates, bool auth)
 292         __acquires(RCU)
 293 {
 294         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 295         struct ieee80211_local *local = sdata->local;
 296         struct sta_info *sta;
 297         struct ieee80211_chanctx_conf *chanctx_conf;
 298         int band;
 299
 300         /*
 301          * XXX: Consider removing the least recently used entry and
 302          *      allow new one to be added.
 303          */
 304         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 305                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 306                                     sdata->name, addr);
 307                 rcu_read_lock();
 308                 return NULL;
 309         }
 310
 311         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
 312                 rcu_read_lock();
 313                 return NULL;
 314         }
 315
 316         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
 317                 rcu_read_lock();
 318                 return NULL;
 319         }
 320
 321         rcu_read_lock();
 322         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 323         if (WARN_ON_ONCE(!chanctx_conf))
 324                 return NULL;
 325         band = chanctx_conf->channel->band;
 326         rcu_read_unlock();
 327
 328         sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 329         if (!sta) {
 330                 rcu_read_lock();
 331                 return NULL;
 332         }
 333
 334         sta->last_rx = jiffies;
 335
 336         /* make sure mandatory rates are always added */
 337         sta->sta.supp_rates[band] = supp_rates |
 338                         ieee80211_mandatory_rates(local, band);
 339
 340         return ieee80211_ibss_finish_sta(sta, auth);
 341 }
 342
 343 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
 344                                           struct ieee80211_mgmt *mgmt,
 345                                           size_t len)
 346 {
 347         u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
 348
 349         if (len < IEEE80211_DEAUTH_FRAME_LEN)
 350                 return;
 351
 352         ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
 353                  mgmt->sa, mgmt->da, mgmt->bssid, reason);
 354         sta_info_destroy_addr(sdata, mgmt->sa);
 355 }
 356
 357 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
 358                                         struct ieee80211_mgmt *mgmt,
 359                                         size_t len)
 360 {
 361         u16 auth_alg, auth_transaction;
 362         struct sta_info *sta;
 363         u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
 364
 365         lockdep_assert_held(&sdata->u.ibss.mtx);
 366
 367         if (len < 24 + 6)
 368                 return;
 369
 370         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
 371         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
 372
 373         if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
 374                 return;
 375         ibss_dbg(sdata,
 376                  "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
 377                  mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
 378         sta_info_destroy_addr(sdata, mgmt->sa);
 379         sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
 380         rcu_read_unlock();
 381
 382         /*
 383          * if we have any problem in allocating the new station, we reply with a
 384          * DEAUTH frame to tell the other end that we had a problem
 385          */
 386         if (!sta) {
 387                 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
 388                                                IEEE80211_STYPE_DEAUTH,
 389                                                WLAN_REASON_UNSPECIFIED, true,
 390                                                deauth_frame_buf);
 391                 return;
 392         }
 393
 394         /*
 395          * IEEE 802.11 standard does not require authentication in IBSS
 396          * networks and most implementations do not seem to use it.
 397          * However, try to reply to authentication attempts if someone
 398          * has actually implemented this.
 399          */
 400         ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
 401                             mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0);
 402 }
 403
 404 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 405                                   struct ieee80211_mgmt *mgmt,
 406                                   size_t len,
 407                                   struct ieee80211_rx_status *rx_status,
 408                                   struct ieee802_11_elems *elems,
 409                                   bool beacon)
 410 {
 411         struct ieee80211_local *local = sdata->local;
 412         int freq;
 413         struct cfg80211_bss *cbss;
 414         struct ieee80211_bss *bss;
 415         struct sta_info *sta;
 416         struct ieee80211_channel *channel;
 417         u64 beacon_timestamp, rx_timestamp;
 418         u32 supp_rates = 0;
 419         enum ieee80211_band band = rx_status->band;
 420         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 421         bool rates_updated = false;
 422
 423         if (elems->ds_params && elems->ds_params_len == 1)
 424                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
 425                                                       band);
 426         else
 427                 freq = rx_status->freq;
 428
 429         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 430
 431         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 432                 return;
 433
 434         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 435             ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
 436
 437                 rcu_read_lock();
 438                 sta = sta_info_get(sdata, mgmt->sa);
 439
 440                 if (elems->supp_rates) {
 441                         supp_rates = ieee80211_sta_get_rates(local, elems,
 442                                                              band, NULL);
 443                         if (sta) {
 444                                 u32 prev_rates;
 445
 446                                 prev_rates = sta->sta.supp_rates[band];
 447                                 /* make sure mandatory rates are always added */
 448                                 sta->sta.supp_rates[band] = supp_rates |
 449                                         ieee80211_mandatory_rates(local, band);
 450
 451                                 if (sta->sta.supp_rates[band] != prev_rates) {
 452                                         ibss_dbg(sdata,
 453                                                  "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
 454                                                  sta->sta.addr, prev_rates,
 455                                                  sta->sta.supp_rates[band]);
 456                                         rates_updated = true;
 457                                 }
 458                         } else {
 459                                 rcu_read_unlock();
 460                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
 461                                                 mgmt->sa, supp_rates, true);
 462                         }
 463                 }
 464
 465                 if (sta && elems->wmm_info)
 466                         set_sta_flag(sta, WLAN_STA_WME);
 467
 468                 if (sta && elems->ht_operation && elems->ht_cap_elem &&
 469                     sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
 470                         /* we both use HT */
 471                         struct ieee80211_sta_ht_cap sta_ht_cap_new;
 472                         enum nl80211_channel_type channel_type =
 473                                 ieee80211_ht_oper_to_channel_type(
 474                                                         elems->ht_operation);
 475
 476                         ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 477                                                           elems->ht_cap_elem,
 478                                                           &sta_ht_cap_new);
 479
 480                         /*
 481                          * fall back to HT20 if we don't use or use
 482                          * the other extension channel
 483                          */
 484                         if (!(channel_type == NL80211_CHAN_HT40MINUS ||
 485                               channel_type == NL80211_CHAN_HT40PLUS) ||
 486                             channel_type != sdata->u.ibss.channel_type)
 487                                 sta_ht_cap_new.cap &=
 488                                         ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 489
 490                         if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
 491                                    sizeof(sta_ht_cap_new))) {
 492                                 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
 493                                        sizeof(sta_ht_cap_new));
 494                                 rates_updated = true;
 495                         }
 496                 }
 497
 498                 if (sta && rates_updated) {
 499                         drv_sta_rc_update(local, sdata, &sta->sta,
 500                                           IEEE80211_RC_SUPP_RATES_CHANGED);
 501                         rate_control_rate_init(sta);
 502                 }
 503
 504                 rcu_read_unlock();
 505         }
 506
 507         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 508                                         channel, beacon);
 509         if (!bss)
 510                 return;
 511
 512         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 513
 514         /* was just updated in ieee80211_bss_info_update */
 515         beacon_timestamp = cbss->tsf;
 516
 517         /* check if we need to merge IBSS */
 518
 519         /* we use a fixed BSSID */
 520         if (sdata->u.ibss.fixed_bssid)
 521                 goto put_bss;
 522
 523         /* not an IBSS */
 524         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 525                 goto put_bss;
 526
 527         /* different channel */
 528         if (sdata->u.ibss.fixed_channel &&
 529             sdata->u.ibss.channel != cbss->channel)
 530                 goto put_bss;
 531
 532         /* different SSID */
 533         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 534             memcmp(elems->ssid, sdata->u.ibss.ssid,
 535                                 sdata->u.ibss.ssid_len))
 536                 goto put_bss;
 537
 538         /* same BSSID */
 539         if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
 540                 goto put_bss;
 541
 542         if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
 543                 /*
 544                  * For correct IBSS merging we need mactime; since mactime is
 545                  * defined as the time the first data symbol of the frame hits
 546                  * the PHY, and the timestamp of the beacon is defined as "the
 547                  * time that the data symbol containing the first bit of the
 548                  * timestamp is transmitted to the PHY plus the transmitting
 549                  * STA's delays through its local PHY from the MAC-PHY
 550                  * interface to its interface with the WM" (802.11 11.1.2)
 551                  * - equals the time this bit arrives at the receiver - we have
 552                  * to take into account the offset between the two.
 553                  *
 554                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 555                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 556                  */
 557                 int rate;
 558
 559                 if (rx_status->flag & RX_FLAG_HT)
 560                         rate = 65; /* TODO: HT rates */
 561                 else
 562                         rate = local->hw.wiphy->bands[band]->
 563                                 bitrates[rx_status->rate_idx].bitrate;
 564
 565                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 566         } else {
 567                 /*
 568                  * second best option: get current TSF
 569                  * (will return -1 if not supported)
 570                  */
 571                 rx_timestamp = drv_get_tsf(local, sdata);
 572         }
 573
 574         ibss_dbg(sdata,
 575                  "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 576                  mgmt->sa, mgmt->bssid,
 577                  (unsigned long long)rx_timestamp,
 578                  (unsigned long long)beacon_timestamp,
 579                  (unsigned long long)(rx_timestamp - beacon_timestamp),
 580                  jiffies);
 581
 582         if (beacon_timestamp > rx_timestamp) {
 583                 ibss_dbg(sdata,
 584                          "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
 585                          mgmt->bssid);
 586                 ieee80211_sta_join_ibss(sdata, bss);
 587                 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
 588                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 589                                        supp_rates, true);
 590                 rcu_read_unlock();
 591         }
 592
 593  put_bss:
 594         ieee80211_rx_bss_put(local, bss);
 595 }
 596
 597 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
 598                               const u8 *bssid, const u8 *addr,
 599                               u32 supp_rates)
 600 {
 601         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 602         struct ieee80211_local *local = sdata->local;
 603         struct sta_info *sta;
 604         struct ieee80211_chanctx_conf *chanctx_conf;
 605         int band;
 606
 607         /*
 608          * XXX: Consider removing the least recently used entry and
 609          *      allow new one to be added.
 610          */
 611         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 612                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 613                                     sdata->name, addr);
 614                 return;
 615         }
 616
 617         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 618                 return;
 619
 620         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
 621                 return;
 622
 623         rcu_read_lock();
 624         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 625         if (WARN_ON_ONCE(!chanctx_conf)) {
 626                 rcu_read_unlock();
 627                 return;
 628         }
 629         band = chanctx_conf->channel->band;
 630         rcu_read_unlock();
 631
 632         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 633         if (!sta)
 634                 return;
 635
 636         sta->last_rx = jiffies;
 637
 638         /* make sure mandatory rates are always added */
 639         sta->sta.supp_rates[band] = supp_rates |
 640                         ieee80211_mandatory_rates(local, band);
 641
 642         spin_lock(&ifibss->incomplete_lock);
 643         list_add(&sta->list, &ifibss->incomplete_stations);
 644         spin_unlock(&ifibss->incomplete_lock);
 645         ieee80211_queue_work(&local->hw, &sdata->work);
 646 }
 647
 648 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 649 {
 650         struct ieee80211_local *local = sdata->local;
 651         int active = 0;
 652         struct sta_info *sta;
 653
 654         lockdep_assert_held(&sdata->u.ibss.mtx);
 655
 656         rcu_read_lock();
 657
 658         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 659                 if (sta->sdata == sdata &&
 660                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 661                                jiffies)) {
 662                         active++;
 663                         break;
 664                 }
 665         }
 666
 667         rcu_read_unlock();
 668
 669         return active;
 670 }
 671
 672 /*
 673  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 674  */
 675
 676 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 677 {
 678         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 679
 680         lockdep_assert_held(&ifibss->mtx);
 681
 682         mod_timer(&ifibss->timer,
 683                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 684
 685         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 686
 687         if (time_before(jiffies, ifibss->last_scan_completed +
 688                        IEEE80211_IBSS_MERGE_INTERVAL))
 689                 return;
 690
 691         if (ieee80211_sta_active_ibss(sdata))
 692                 return;
 693
 694         if (ifibss->fixed_channel)
 695                 return;
 696
 697         sdata_info(sdata,
 698                    "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
 699
 700         ieee80211_request_internal_scan(sdata,
 701                         ifibss->ssid, ifibss->ssid_len, NULL);
 702 }
 703
 704 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 705 {
 706         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 707         u8 bssid[ETH_ALEN];
 708         u16 capability;
 709         int i;
 710
 711         lockdep_assert_held(&ifibss->mtx);
 712
 713         if (ifibss->fixed_bssid) {
 714                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 715         } else {
 716                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 717                  * own MAC address to make sure that devices that do not have proper
 718                  * random number generator get different BSSID. */
 719                 get_random_bytes(bssid, ETH_ALEN);
 720                 for (i = 0; i < ETH_ALEN; i++)
 721                         bssid[i] ^= sdata->vif.addr[i];
 722                 bssid[0] &= ~0x01;
 723                 bssid[0] |= 0x02;
 724         }
 725
 726         sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
 727
 728         capability = WLAN_CAPABILITY_IBSS;
 729
 730         if (ifibss->privacy)
 731                 capability |= WLAN_CAPABILITY_PRIVACY;
 732         else
 733                 sdata->drop_unencrypted = 0;
 734
 735         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 736                                   ifibss->channel, ifibss->basic_rates,
 737                                   capability, 0);
 738 }
 739
 740 /*
 741  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 742  */
 743
 744 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 745 {
 746         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 747         struct ieee80211_local *local = sdata->local;
 748         struct cfg80211_bss *cbss;
 749         struct ieee80211_channel *chan = NULL;
 750         const u8 *bssid = NULL;
 751         int active_ibss;
 752         u16 capability;
 753
 754         lockdep_assert_held(&ifibss->mtx);
 755
 756         active_ibss = ieee80211_sta_active_ibss(sdata);
 757         ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
 758
 759         if (active_ibss)
 760                 return;
 761
 762         capability = WLAN_CAPABILITY_IBSS;
 763         if (ifibss->privacy)
 764                 capability |= WLAN_CAPABILITY_PRIVACY;
 765         if (ifibss->fixed_bssid)
 766                 bssid = ifibss->bssid;
 767         if (ifibss->fixed_channel)
 768                 chan = ifibss->channel;
 769         if (!is_zero_ether_addr(ifibss->bssid))
 770                 bssid = ifibss->bssid;
 771         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 772                                 ifibss->ssid, ifibss->ssid_len,
 773                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 774                                 capability);
 775
 776         if (cbss) {
 777                 struct ieee80211_bss *bss;
 778
 779                 bss = (void *)cbss->priv;
 780                 ibss_dbg(sdata,
 781                          "sta_find_ibss: selected %pM current %pM\n",
 782                          cbss->bssid, ifibss->bssid);
 783                 sdata_info(sdata,
 784                            "Selected IBSS BSSID %pM based on configured SSID\n",
 785                            cbss->bssid);
 786
 787                 ieee80211_sta_join_ibss(sdata, bss);
 788                 ieee80211_rx_bss_put(local, bss);
 789                 return;
 790         }
 791
 792         ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
 793
 794         /* Selected IBSS not found in current scan results - try to scan */
 795         if (time_after(jiffies, ifibss->last_scan_completed +
 796                                         IEEE80211_SCAN_INTERVAL)) {
 797                 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 798
 799                 ieee80211_request_internal_scan(sdata,
 800                                 ifibss->ssid, ifibss->ssid_len,
 801                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 802         } else {
 803                 int interval = IEEE80211_SCAN_INTERVAL;
 804
 805                 if (time_after(jiffies, ifibss->ibss_join_req +
 806                                IEEE80211_IBSS_JOIN_TIMEOUT))
 807                         ieee80211_sta_create_ibss(sdata);
 808
 809                 mod_timer(&ifibss->timer,
 810                           round_jiffies(jiffies + interval));
 811         }
 812 }
 813
 814 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 815                                         struct sk_buff *req)
 816 {
 817         struct ieee80211_mgmt *mgmt = (void *)req->data;
 818         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 819         struct ieee80211_local *local = sdata->local;
 820         int tx_last_beacon, len = req->len;
 821         struct sk_buff *skb;
 822         struct ieee80211_mgmt *resp;
 823         struct sk_buff *presp;
 824         u8 *pos, *end;
 825
 826         lockdep_assert_held(&ifibss->mtx);
 827
 828         presp = rcu_dereference_protected(ifibss->presp,
 829                                           lockdep_is_held(&ifibss->mtx));
 830
 831         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 832             len < 24 + 2 || !presp)
 833                 return;
 834
 835         tx_last_beacon = drv_tx_last_beacon(local);
 836
 837         ibss_dbg(sdata,
 838                  "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
 839                  mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
 840
 841         if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
 842                 return;
 843
 844         if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
 845             !is_broadcast_ether_addr(mgmt->bssid))
 846                 return;
 847
 848         end = ((u8 *) mgmt) + len;
 849         pos = mgmt->u.probe_req.variable;
 850         if (pos[0] != WLAN_EID_SSID ||
 851             pos + 2 + pos[1] > end) {
 852                 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
 853                          mgmt->sa);
 854                 return;
 855         }
 856         if (pos[1] != 0 &&
 857             (pos[1] != ifibss->ssid_len ||
 858              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 859                 /* Ignore ProbeReq for foreign SSID */
 860                 return;
 861         }
 862
 863         /* Reply with ProbeResp */
 864         skb = skb_copy(presp, GFP_KERNEL);
 865         if (!skb)
 866                 return;
 867
 868         resp = (struct ieee80211_mgmt *) skb->data;
 869         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 870         ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
 871         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 872         ieee80211_tx_skb(sdata, skb);
 873 }
 874
 875 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 876                                          struct ieee80211_mgmt *mgmt,
 877                                          size_t len,
 878                                          struct ieee80211_rx_status *rx_status)
 879 {
 880         size_t baselen;
 881         struct ieee802_11_elems elems;
 882
 883         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 884         if (baselen > len)
 885                 return;
 886
 887         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 888                                 &elems);
 889
 890         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 891 }
 892
 893 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 894                                      struct ieee80211_mgmt *mgmt,
 895                                      size_t len,
 896                                      struct ieee80211_rx_status *rx_status)
 897 {
 898         size_t baselen;
 899         struct ieee802_11_elems elems;
 900
 901         /* Process beacon from the current BSS */
 902         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 903         if (baselen > len)
 904                 return;
 905
 906         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 907
 908         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 909 }
 910
 911 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 912                                    struct sk_buff *skb)
 913 {
 914         struct ieee80211_rx_status *rx_status;
 915         struct ieee80211_mgmt *mgmt;
 916         u16 fc;
 917
 918         rx_status = IEEE80211_SKB_RXCB(skb);
 919         mgmt = (struct ieee80211_mgmt *) skb->data;
 920         fc = le16_to_cpu(mgmt->frame_control);
 921
 922         mutex_lock(&sdata->u.ibss.mtx);
 923
 924         if (!sdata->u.ibss.ssid_len)
 925                 goto mgmt_out; /* not ready to merge yet */
 926
 927         switch (fc & IEEE80211_FCTL_STYPE) {
 928         case IEEE80211_STYPE_PROBE_REQ:
 929                 ieee80211_rx_mgmt_probe_req(sdata, skb);
 930                 break;
 931         case IEEE80211_STYPE_PROBE_RESP:
 932                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 933                                              rx_status);
 934                 break;
 935         case IEEE80211_STYPE_BEACON:
 936                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 937                                          rx_status);
 938                 break;
 939         case IEEE80211_STYPE_AUTH:
 940                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 941                 break;
 942         case IEEE80211_STYPE_DEAUTH:
 943                 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
 944                 break;
 945         }
 946
 947  mgmt_out:
 948         mutex_unlock(&sdata->u.ibss.mtx);
 949 }
 950
 951 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 952 {
 953         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 954         struct sta_info *sta;
 955
 956         mutex_lock(&ifibss->mtx);
 957
 958         /*
 959          * Work could be scheduled after scan or similar
 960          * when we aren't even joined (or trying) with a
 961          * network.
 962          */
 963         if (!ifibss->ssid_len)
 964                 goto out;
 965
 966         spin_lock_bh(&ifibss->incomplete_lock);
 967         while (!list_empty(&ifibss->incomplete_stations)) {
 968                 sta = list_first_entry(&ifibss->incomplete_stations,
 969                                        struct sta_info, list);
 970                 list_del(&sta->list);
 971                 spin_unlock_bh(&ifibss->incomplete_lock);
 972
 973                 ieee80211_ibss_finish_sta(sta, true);
 974                 rcu_read_unlock();
 975                 spin_lock_bh(&ifibss->incomplete_lock);
 976         }
 977         spin_unlock_bh(&ifibss->incomplete_lock);
 978
 979         switch (ifibss->state) {
 980         case IEEE80211_IBSS_MLME_SEARCH:
 981                 ieee80211_sta_find_ibss(sdata);
 982                 break;
 983         case IEEE80211_IBSS_MLME_JOINED:
 984                 ieee80211_sta_merge_ibss(sdata);
 985                 break;
 986         default:
 987                 WARN_ON(1);
 988                 break;
 989         }
 990
 991  out:
 992         mutex_unlock(&ifibss->mtx);
 993 }
 994
 995 static void ieee80211_ibss_timer(unsigned long data)
 996 {
 997         struct ieee80211_sub_if_data *sdata =
 998                 (struct ieee80211_sub_if_data *) data;
 999         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1000         struct ieee80211_local *local = sdata->local;
1001
1002         if (local->quiescing) {
1003                 ifibss->timer_running = true;
1004                 return;
1005         }
1006
1007         ieee80211_queue_work(&local->hw, &sdata->work);
1008 }
1009
1010 #ifdef CONFIG_PM
1011 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
1012 {
1013         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1014
1015         if (del_timer_sync(&ifibss->timer))
1016                 ifibss->timer_running = true;
1017 }
1018
1019 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
1020 {
1021         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1022
1023         if (ifibss->timer_running) {
1024                 add_timer(&ifibss->timer);
1025                 ifibss->timer_running = false;
1026         }
1027 }
1028 #endif
1029
1030 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1031 {
1032         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1033
1034         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1035                     (unsigned long) sdata);
1036         mutex_init(&ifibss->mtx);
1037         INIT_LIST_HEAD(&ifibss->incomplete_stations);
1038         spin_lock_init(&ifibss->incomplete_lock);
1039 }
1040
1041 /* scan finished notification */
1042 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1043 {
1044         struct ieee80211_sub_if_data *sdata;
1045
1046         mutex_lock(&local->iflist_mtx);
1047         list_for_each_entry(sdata, &local->interfaces, list) {
1048                 if (!ieee80211_sdata_running(sdata))
1049                         continue;
1050                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1051                         continue;
1052                 sdata->u.ibss.last_scan_completed = jiffies;
1053                 ieee80211_queue_work(&local->hw, &sdata->work);
1054         }
1055         mutex_unlock(&local->iflist_mtx);
1056 }
1057
1058 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1059                         struct cfg80211_ibss_params *params)
1060 {
1061         struct sk_buff *skb;
1062         u32 changed = 0;
1063
1064         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
1065                             sizeof(struct ieee80211_hdr_3addr) +
1066                             12 /* struct ieee80211_mgmt.u.beacon */ +
1067                             2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
1068                             2 + 8 /* max Supported Rates */ +
1069                             3 /* max DS params */ +
1070                             4 /* IBSS params */ +
1071                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
1072                             2 + sizeof(struct ieee80211_ht_cap) +
1073                             2 + sizeof(struct ieee80211_ht_operation) +
1074                             params->ie_len);
1075         if (!skb)
1076                 return -ENOMEM;
1077
1078         mutex_lock(&sdata->u.ibss.mtx);
1079
1080         if (params->bssid) {
1081                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1082                 sdata->u.ibss.fixed_bssid = true;
1083         } else
1084                 sdata->u.ibss.fixed_bssid = false;
1085
1086         sdata->u.ibss.privacy = params->privacy;
1087         sdata->u.ibss.control_port = params->control_port;
1088         sdata->u.ibss.basic_rates = params->basic_rates;
1089         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1090                sizeof(params->mcast_rate));
1091
1092         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1093
1094         sdata->u.ibss.channel = params->channel;
1095         sdata->u.ibss.channel_type = params->channel_type;
1096         sdata->u.ibss.fixed_channel = params->channel_fixed;
1097
1098         if (params->ie) {
1099                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1100                                            GFP_KERNEL);
1101                 if (sdata->u.ibss.ie)
1102                         sdata->u.ibss.ie_len = params->ie_len;
1103         }
1104
1105         sdata->u.ibss.skb = skb;
1106         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1107         sdata->u.ibss.ibss_join_req = jiffies;
1108
1109         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
1110         sdata->u.ibss.ssid_len = params->ssid_len;
1111
1112         mutex_unlock(&sdata->u.ibss.mtx);
1113
1114         mutex_lock(&sdata->local->mtx);
1115         ieee80211_recalc_idle(sdata->local);
1116         mutex_unlock(&sdata->local->mtx);
1117
1118         /*
1119          * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1120          * reserved, but an HT STA shall protect HT transmissions as though
1121          * the HT Protection field were set to non-HT mixed mode.
1122          *
1123          * In an IBSS, the RIFS Mode field of the HT Operation element is
1124          * also reserved, but an HT STA shall operate as though this field
1125          * were set to 1.
1126          */
1127
1128         sdata->vif.bss_conf.ht_operation_mode |=
1129                   IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1130                 | IEEE80211_HT_PARAM_RIFS_MODE;
1131
1132         changed |= BSS_CHANGED_HT;
1133         ieee80211_bss_info_change_notify(sdata, changed);
1134
1135         sdata->smps_mode = IEEE80211_SMPS_OFF;
1136         sdata->needed_rx_chains = sdata->local->rx_chains;
1137
1138         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1139
1140         return 0;
1141 }
1142
1143 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1144 {
1145         struct sk_buff *skb;
1146         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1147         struct ieee80211_local *local = sdata->local;
1148         struct cfg80211_bss *cbss;
1149         u16 capability;
1150         int active_ibss;
1151         struct sta_info *sta;
1152
1153         mutex_lock(&sdata->u.ibss.mtx);
1154
1155         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1156         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1157         sdata->u.ibss.ssid_len = 0;
1158
1159         active_ibss = ieee80211_sta_active_ibss(sdata);
1160
1161         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1162                 capability = WLAN_CAPABILITY_IBSS;
1163
1164                 if (ifibss->privacy)
1165                         capability |= WLAN_CAPABILITY_PRIVACY;
1166
1167                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1168                                         ifibss->bssid, ifibss->ssid,
1169                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1170                                         WLAN_CAPABILITY_PRIVACY,
1171                                         capability);
1172
1173                 if (cbss) {
1174                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
1175                         cfg80211_put_bss(cbss);
1176                 }
1177         }
1178
1179         sta_info_flush(sdata->local, sdata);
1180
1181         spin_lock_bh(&ifibss->incomplete_lock);
1182         while (!list_empty(&ifibss->incomplete_stations)) {
1183                 sta = list_first_entry(&ifibss->incomplete_stations,
1184                                        struct sta_info, list);
1185                 list_del(&sta->list);
1186                 spin_unlock_bh(&ifibss->incomplete_lock);
1187
1188                 sta_info_free(local, sta);
1189                 spin_lock_bh(&ifibss->incomplete_lock);
1190         }
1191         spin_unlock_bh(&ifibss->incomplete_lock);
1192
1193         netif_carrier_off(sdata->dev);
1194
1195         /* remove beacon */
1196         kfree(sdata->u.ibss.ie);
1197         skb = rcu_dereference_protected(sdata->u.ibss.presp,
1198                                         lockdep_is_held(&sdata->u.ibss.mtx));
1199         RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1200         sdata->vif.bss_conf.ibss_joined = false;
1201         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1202                                                 BSS_CHANGED_IBSS);
1203         synchronize_rcu();
1204         kfree_skb(skb);
1205
1206         skb_queue_purge(&sdata->skb_queue);
1207
1208         del_timer_sync(&sdata->u.ibss.timer);
1209
1210         mutex_unlock(&sdata->u.ibss.mtx);
1211
1212         mutex_lock(&local->mtx);
1213         ieee80211_recalc_idle(sdata->local);
1214         mutex_unlock(&local->mtx);
1215
1216         return 0;
1217 }