linux/net/mac80211/ibss.c
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   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 * Copyright 2013-2014  Intel Mobile Communications GmbH
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License version 2 as
  13 * published by the Free Software Foundation.
  14 */
  15
  16#include <linux/delay.h>
  17#include <linux/slab.h>
  18#include <linux/if_ether.h>
  19#include <linux/skbuff.h>
  20#include <linux/if_arp.h>
  21#include <linux/etherdevice.h>
  22#include <linux/rtnetlink.h>
  23#include <net/mac80211.h>
  24
  25#include "ieee80211_i.h"
  26#include "driver-ops.h"
  27#include "rate.h"
  28
  29#define IEEE80211_SCAN_INTERVAL (2 * HZ)
  30#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  31
  32#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  33#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  34#define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
  35
  36#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  37
  38static struct beacon_data *
  39ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
  40                           const int beacon_int, const u32 basic_rates,
  41                           const u16 capability, u64 tsf,
  42                           struct cfg80211_chan_def *chandef,
  43                           bool *have_higher_than_11mbit,
  44                           struct cfg80211_csa_settings *csa_settings)
  45{
  46        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  47        struct ieee80211_local *local = sdata->local;
  48        int rates_n = 0, i, ri;
  49        struct ieee80211_mgmt *mgmt;
  50        u8 *pos;
  51        struct ieee80211_supported_band *sband;
  52        u32 rate_flags, rates = 0, rates_added = 0;
  53        struct beacon_data *presp;
  54        int frame_len;
  55        int shift;
  56
  57        /* Build IBSS probe response */
  58        frame_len = sizeof(struct ieee80211_hdr_3addr) +
  59                    12 /* struct ieee80211_mgmt.u.beacon */ +
  60                    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
  61                    2 + 8 /* max Supported Rates */ +
  62                    3 /* max DS params */ +
  63                    4 /* IBSS params */ +
  64                    5 /* Channel Switch Announcement */ +
  65                    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
  66                    2 + sizeof(struct ieee80211_ht_cap) +
  67                    2 + sizeof(struct ieee80211_ht_operation) +
  68                    ifibss->ie_len;
  69        presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
  70        if (!presp)
  71                return NULL;
  72
  73        presp->head = (void *)(presp + 1);
  74
  75        mgmt = (void *) presp->head;
  76        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  77                                          IEEE80211_STYPE_PROBE_RESP);
  78        eth_broadcast_addr(mgmt->da);
  79        memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  80        memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
  81        mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
  82        mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
  83        mgmt->u.beacon.capab_info = cpu_to_le16(capability);
  84
  85        pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
  86
  87        *pos++ = WLAN_EID_SSID;
  88        *pos++ = ifibss->ssid_len;
  89        memcpy(pos, ifibss->ssid, ifibss->ssid_len);
  90        pos += ifibss->ssid_len;
  91
  92        sband = local->hw.wiphy->bands[chandef->chan->band];
  93        rate_flags = ieee80211_chandef_rate_flags(chandef);
  94        shift = ieee80211_chandef_get_shift(chandef);
  95        rates_n = 0;
  96        if (have_higher_than_11mbit)
  97                *have_higher_than_11mbit = false;
  98
  99        for (i = 0; i < sband->n_bitrates; i++) {
 100                if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 101                        continue;
 102                if (sband->bitrates[i].bitrate > 110 &&
 103                    have_higher_than_11mbit)
 104                        *have_higher_than_11mbit = true;
 105
 106                rates |= BIT(i);
 107                rates_n++;
 108        }
 109
 110        *pos++ = WLAN_EID_SUPP_RATES;
 111        *pos++ = min_t(int, 8, rates_n);
 112        for (ri = 0; ri < sband->n_bitrates; ri++) {
 113                int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
 114                                        5 * (1 << shift));
 115                u8 basic = 0;
 116                if (!(rates & BIT(ri)))
 117                        continue;
 118
 119                if (basic_rates & BIT(ri))
 120                        basic = 0x80;
 121                *pos++ = basic | (u8) rate;
 122                if (++rates_added == 8) {
 123                        ri++; /* continue at next rate for EXT_SUPP_RATES */
 124                        break;
 125                }
 126        }
 127
 128        if (sband->band == IEEE80211_BAND_2GHZ) {
 129                *pos++ = WLAN_EID_DS_PARAMS;
 130                *pos++ = 1;
 131                *pos++ = ieee80211_frequency_to_channel(
 132                                chandef->chan->center_freq);
 133        }
 134
 135        *pos++ = WLAN_EID_IBSS_PARAMS;
 136        *pos++ = 2;
 137        /* FIX: set ATIM window based on scan results */
 138        *pos++ = 0;
 139        *pos++ = 0;
 140
 141        if (csa_settings) {
 142                *pos++ = WLAN_EID_CHANNEL_SWITCH;
 143                *pos++ = 3;
 144                *pos++ = csa_settings->block_tx ? 1 : 0;
 145                *pos++ = ieee80211_frequency_to_channel(
 146                                csa_settings->chandef.chan->center_freq);
 147                presp->csa_counter_offsets[0] = (pos - presp->head);
 148                *pos++ = csa_settings->count;
 149        }
 150
 151        /* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
 152        if (rates_n > 8) {
 153                *pos++ = WLAN_EID_EXT_SUPP_RATES;
 154                *pos++ = rates_n - 8;
 155                for (; ri < sband->n_bitrates; ri++) {
 156                        int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
 157                                                5 * (1 << shift));
 158                        u8 basic = 0;
 159                        if (!(rates & BIT(ri)))
 160                                continue;
 161
 162                        if (basic_rates & BIT(ri))
 163                                basic = 0x80;
 164                        *pos++ = basic | (u8) rate;
 165                }
 166        }
 167
 168        if (ifibss->ie_len) {
 169                memcpy(pos, ifibss->ie, ifibss->ie_len);
 170                pos += ifibss->ie_len;
 171        }
 172
 173        /* add HT capability and information IEs */
 174        if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
 175            chandef->width != NL80211_CHAN_WIDTH_5 &&
 176            chandef->width != NL80211_CHAN_WIDTH_10 &&
 177            sband->ht_cap.ht_supported) {
 178                struct ieee80211_sta_ht_cap ht_cap;
 179
 180                memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
 181                ieee80211_apply_htcap_overrides(sdata, &ht_cap);
 182
 183                pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
 184                /*
 185                 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
 186                 * field and RIFS Mode are reserved in IBSS mode, therefore
 187                 * keep them at 0
 188                 */
 189                pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
 190                                                 chandef, 0);
 191        }
 192
 193        if (local->hw.queues >= IEEE80211_NUM_ACS)
 194                pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
 195
 196        presp->head_len = pos - presp->head;
 197        if (WARN_ON(presp->head_len > frame_len))
 198                goto error;
 199
 200        return presp;
 201error:
 202        kfree(presp);
 203        return NULL;
 204}
 205
 206static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 207                                      const u8 *bssid, const int beacon_int,
 208                                      struct cfg80211_chan_def *req_chandef,
 209                                      const u32 basic_rates,
 210                                      const u16 capability, u64 tsf,
 211                                      bool creator)
 212{
 213        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 214        struct ieee80211_local *local = sdata->local;
 215        struct ieee80211_mgmt *mgmt;
 216        struct cfg80211_bss *bss;
 217        u32 bss_change;
 218        struct cfg80211_chan_def chandef;
 219        struct ieee80211_channel *chan;
 220        struct beacon_data *presp;
 221        enum nl80211_bss_scan_width scan_width;
 222        bool have_higher_than_11mbit;
 223        bool radar_required;
 224        int err;
 225
 226        sdata_assert_lock(sdata);
 227
 228        /* Reset own TSF to allow time synchronization work. */
 229        drv_reset_tsf(local, sdata);
 230
 231        if (!ether_addr_equal(ifibss->bssid, bssid))
 232                sta_info_flush(sdata);
 233
 234        /* if merging, indicate to driver that we leave the old IBSS */
 235        if (sdata->vif.bss_conf.ibss_joined) {
 236                sdata->vif.bss_conf.ibss_joined = false;
 237                sdata->vif.bss_conf.ibss_creator = false;
 238                sdata->vif.bss_conf.enable_beacon = false;
 239                netif_carrier_off(sdata->dev);
 240                ieee80211_bss_info_change_notify(sdata,
 241                                                 BSS_CHANGED_IBSS |
 242                                                 BSS_CHANGED_BEACON_ENABLED);
 243                drv_leave_ibss(local, sdata);
 244        }
 245
 246        presp = rcu_dereference_protected(ifibss->presp,
 247                                          lockdep_is_held(&sdata->wdev.mtx));
 248        RCU_INIT_POINTER(ifibss->presp, NULL);
 249        if (presp)
 250                kfree_rcu(presp, rcu_head);
 251
 252        sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 253
 254        /* make a copy of the chandef, it could be modified below. */
 255        chandef = *req_chandef;
 256        chan = chandef.chan;
 257        if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
 258                                     NL80211_IFTYPE_ADHOC)) {
 259                if (chandef.width == NL80211_CHAN_WIDTH_5 ||
 260                    chandef.width == NL80211_CHAN_WIDTH_10 ||
 261                    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
 262                    chandef.width == NL80211_CHAN_WIDTH_20) {
 263                        sdata_info(sdata,
 264                                   "Failed to join IBSS, beacons forbidden\n");
 265                        return;
 266                }
 267                chandef.width = NL80211_CHAN_WIDTH_20;
 268                chandef.center_freq1 = chan->center_freq;
 269                /* check again for downgraded chandef */
 270                if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
 271                                             NL80211_IFTYPE_ADHOC)) {
 272                        sdata_info(sdata,
 273                                   "Failed to join IBSS, beacons forbidden\n");
 274                        return;
 275                }
 276        }
 277
 278        err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 279                                            &chandef, NL80211_IFTYPE_ADHOC);
 280        if (err < 0) {
 281                sdata_info(sdata,
 282                           "Failed to join IBSS, invalid chandef\n");
 283                return;
 284        }
 285        if (err > 0 && !ifibss->userspace_handles_dfs) {
 286                sdata_info(sdata,
 287                           "Failed to join IBSS, DFS channel without control program\n");
 288                return;
 289        }
 290
 291        radar_required = err;
 292
 293        mutex_lock(&local->mtx);
 294        if (ieee80211_vif_use_channel(sdata, &chandef,
 295                                      ifibss->fixed_channel ?
 296                                        IEEE80211_CHANCTX_SHARED :
 297                                        IEEE80211_CHANCTX_EXCLUSIVE)) {
 298                sdata_info(sdata, "Failed to join IBSS, no channel context\n");
 299                mutex_unlock(&local->mtx);
 300                return;
 301        }
 302        sdata->radar_required = radar_required;
 303        mutex_unlock(&local->mtx);
 304
 305        memcpy(ifibss->bssid, bssid, ETH_ALEN);
 306
 307        presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
 308                                           capability, tsf, &chandef,
 309                                           &have_higher_than_11mbit, NULL);
 310        if (!presp)
 311                return;
 312
 313        rcu_assign_pointer(ifibss->presp, presp);
 314        mgmt = (void *)presp->head;
 315
 316        sdata->vif.bss_conf.enable_beacon = true;
 317        sdata->vif.bss_conf.beacon_int = beacon_int;
 318        sdata->vif.bss_conf.basic_rates = basic_rates;
 319        sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
 320        memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
 321        bss_change = BSS_CHANGED_BEACON_INT;
 322        bss_change |= ieee80211_reset_erp_info(sdata);
 323        bss_change |= BSS_CHANGED_BSSID;
 324        bss_change |= BSS_CHANGED_BEACON;
 325        bss_change |= BSS_CHANGED_BEACON_ENABLED;
 326        bss_change |= BSS_CHANGED_BASIC_RATES;
 327        bss_change |= BSS_CHANGED_HT;
 328        bss_change |= BSS_CHANGED_IBSS;
 329        bss_change |= BSS_CHANGED_SSID;
 330
 331        /*
 332         * In 5 GHz/802.11a, we can always use short slot time.
 333         * (IEEE 802.11-2012 18.3.8.7)
 334         *
 335         * In 2.4GHz, we must always use long slots in IBSS for compatibility
 336         * reasons.
 337         * (IEEE 802.11-2012 19.4.5)
 338         *
 339         * HT follows these specifications (IEEE 802.11-2012 20.3.18)
 340         */
 341        sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
 342        bss_change |= BSS_CHANGED_ERP_SLOT;
 343
 344        /* cf. IEEE 802.11 9.2.12 */
 345        if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
 346                sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
 347        else
 348                sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
 349
 350        ieee80211_set_wmm_default(sdata, true);
 351
 352        sdata->vif.bss_conf.ibss_joined = true;
 353        sdata->vif.bss_conf.ibss_creator = creator;
 354
 355        err = drv_join_ibss(local, sdata);
 356        if (err) {
 357                sdata->vif.bss_conf.ibss_joined = false;
 358                sdata->vif.bss_conf.ibss_creator = false;
 359                sdata->vif.bss_conf.enable_beacon = false;
 360                sdata->vif.bss_conf.ssid_len = 0;
 361                RCU_INIT_POINTER(ifibss->presp, NULL);
 362                kfree_rcu(presp, rcu_head);
 363                mutex_lock(&local->mtx);
 364                ieee80211_vif_release_channel(sdata);
 365                mutex_unlock(&local->mtx);
 366                sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
 367                           err);
 368                return;
 369        }
 370
 371        ieee80211_bss_info_change_notify(sdata, bss_change);
 372
 373        ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 374        mod_timer(&ifibss->timer,
 375                  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 376
 377        scan_width = cfg80211_chandef_to_scan_width(&chandef);
 378        bss = cfg80211_inform_bss_width_frame(local->hw.wiphy, chan,
 379                                              scan_width, mgmt,
 380                                              presp->head_len, 0, GFP_KERNEL);
 381        cfg80211_put_bss(local->hw.wiphy, bss);
 382        netif_carrier_on(sdata->dev);
 383        cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
 384}
 385
 386static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 387                                    struct ieee80211_bss *bss)
 388{
 389        struct cfg80211_bss *cbss =
 390                container_of((void *)bss, struct cfg80211_bss, priv);
 391        struct ieee80211_supported_band *sband;
 392        struct cfg80211_chan_def chandef;
 393        u32 basic_rates;
 394        int i, j;
 395        u16 beacon_int = cbss->beacon_interval;
 396        const struct cfg80211_bss_ies *ies;
 397        enum nl80211_channel_type chan_type;
 398        u64 tsf;
 399        u32 rate_flags;
 400        int shift;
 401
 402        sdata_assert_lock(sdata);
 403
 404        if (beacon_int < 10)
 405                beacon_int = 10;
 406
 407        switch (sdata->u.ibss.chandef.width) {
 408        case NL80211_CHAN_WIDTH_20_NOHT:
 409        case NL80211_CHAN_WIDTH_20:
 410        case NL80211_CHAN_WIDTH_40:
 411                chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
 412                cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
 413                break;
 414        case NL80211_CHAN_WIDTH_5:
 415        case NL80211_CHAN_WIDTH_10:
 416                cfg80211_chandef_create(&chandef, cbss->channel,
 417                                        NL80211_CHAN_WIDTH_20_NOHT);
 418                chandef.width = sdata->u.ibss.chandef.width;
 419                break;
 420        default:
 421                /* fall back to 20 MHz for unsupported modes */
 422                cfg80211_chandef_create(&chandef, cbss->channel,
 423                                        NL80211_CHAN_WIDTH_20_NOHT);
 424                break;
 425        }
 426
 427        sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 428        rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
 429        shift = ieee80211_vif_get_shift(&sdata->vif);
 430
 431        basic_rates = 0;
 432
 433        for (i = 0; i < bss->supp_rates_len; i++) {
 434                int rate = bss->supp_rates[i] & 0x7f;
 435                bool is_basic = !!(bss->supp_rates[i] & 0x80);
 436
 437                for (j = 0; j < sband->n_bitrates; j++) {
 438                        int brate;
 439                        if ((rate_flags & sband->bitrates[j].flags)
 440                            != rate_flags)
 441                                continue;
 442
 443                        brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
 444                                             5 * (1 << shift));
 445                        if (brate == rate) {
 446                                if (is_basic)
 447                                        basic_rates |= BIT(j);
 448                                break;
 449                        }
 450                }
 451        }
 452
 453        rcu_read_lock();
 454        ies = rcu_dereference(cbss->ies);
 455        tsf = ies->tsf;
 456        rcu_read_unlock();
 457
 458        __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 459                                  beacon_int,
 460                                  &chandef,
 461                                  basic_rates,
 462                                  cbss->capability,
 463                                  tsf, false);
 464}
 465
 466int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
 467                              struct cfg80211_csa_settings *csa_settings)
 468{
 469        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 470        struct beacon_data *presp, *old_presp;
 471        struct cfg80211_bss *cbss;
 472        const struct cfg80211_bss_ies *ies;
 473        u16 capability;
 474        u64 tsf;
 475        int ret = 0;
 476
 477        sdata_assert_lock(sdata);
 478
 479        capability = WLAN_CAPABILITY_IBSS;
 480
 481        if (ifibss->privacy)
 482                capability |= WLAN_CAPABILITY_PRIVACY;
 483
 484        cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
 485                                ifibss->bssid, ifibss->ssid,
 486                                ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 487                                WLAN_CAPABILITY_PRIVACY,
 488                                capability);
 489
 490        if (WARN_ON(!cbss)) {
 491                ret = -EINVAL;
 492                goto out;
 493        }
 494
 495        rcu_read_lock();
 496        ies = rcu_dereference(cbss->ies);
 497        tsf = ies->tsf;
 498        rcu_read_unlock();
 499        cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 500
 501        old_presp = rcu_dereference_protected(ifibss->presp,
 502                                          lockdep_is_held(&sdata->wdev.mtx));
 503
 504        presp = ieee80211_ibss_build_presp(sdata,
 505                                           sdata->vif.bss_conf.beacon_int,
 506                                           sdata->vif.bss_conf.basic_rates,
 507                                           capability, tsf, &ifibss->chandef,
 508                                           NULL, csa_settings);
 509        if (!presp) {
 510                ret = -ENOMEM;
 511                goto out;
 512        }
 513
 514        rcu_assign_pointer(ifibss->presp, presp);
 515        if (old_presp)
 516                kfree_rcu(old_presp, rcu_head);
 517
 518        return BSS_CHANGED_BEACON;
 519 out:
 520        return ret;
 521}
 522
 523int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
 524{
 525        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 526        struct cfg80211_bss *cbss;
 527        int err, changed = 0;
 528        u16 capability;
 529
 530        sdata_assert_lock(sdata);
 531
 532        /* update cfg80211 bss information with the new channel */
 533        if (!is_zero_ether_addr(ifibss->bssid)) {
 534                capability = WLAN_CAPABILITY_IBSS;
 535
 536                if (ifibss->privacy)
 537                        capability |= WLAN_CAPABILITY_PRIVACY;
 538
 539                cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
 540                                        ifibss->chandef.chan,
 541                                        ifibss->bssid, ifibss->ssid,
 542                                        ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 543                                        WLAN_CAPABILITY_PRIVACY,
 544                                        capability);
 545                /* XXX: should not really modify cfg80211 data */
 546                if (cbss) {
 547                        cbss->channel = sdata->csa_chandef.chan;
 548                        cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 549                }
 550        }
 551
 552        ifibss->chandef = sdata->csa_chandef;
 553
 554        /* generate the beacon */
 555        err = ieee80211_ibss_csa_beacon(sdata, NULL);
 556        if (err < 0)
 557                return err;
 558
 559        changed |= err;
 560
 561        return changed;
 562}
 563
 564void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
 565{
 566        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 567
 568        cancel_work_sync(&ifibss->csa_connection_drop_work);
 569}
 570
 571static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
 572        __acquires(RCU)
 573{
 574        struct ieee80211_sub_if_data *sdata = sta->sdata;
 575        u8 addr[ETH_ALEN];
 576
 577        memcpy(addr, sta->sta.addr, ETH_ALEN);
 578
 579        ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
 580
 581        sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 582        sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 583        /* authorize the station only if the network is not RSN protected. If
 584         * not wait for the userspace to authorize it */
 585        if (!sta->sdata->u.ibss.control_port)
 586                sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 587
 588        rate_control_rate_init(sta);
 589
 590        /* If it fails, maybe we raced another insertion? */
 591        if (sta_info_insert_rcu(sta))
 592                return sta_info_get(sdata, addr);
 593        return sta;
 594}
 595
 596static struct sta_info *
 597ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
 598                       const u8 *addr, u32 supp_rates)
 599        __acquires(RCU)
 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        struct ieee80211_supported_band *sband;
 606        enum nl80211_bss_scan_width scan_width;
 607        int band;
 608
 609        /*
 610         * XXX: Consider removing the least recently used entry and
 611         *      allow new one to be added.
 612         */
 613        if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 614                net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 615                                    sdata->name, addr);
 616                rcu_read_lock();
 617                return NULL;
 618        }
 619
 620        if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
 621                rcu_read_lock();
 622                return NULL;
 623        }
 624
 625        if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
 626                rcu_read_lock();
 627                return NULL;
 628        }
 629
 630        rcu_read_lock();
 631        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 632        if (WARN_ON_ONCE(!chanctx_conf))
 633                return NULL;
 634        band = chanctx_conf->def.chan->band;
 635        scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
 636        rcu_read_unlock();
 637
 638        sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 639        if (!sta) {
 640                rcu_read_lock();
 641                return NULL;
 642        }
 643
 644        sta->last_rx = jiffies;
 645
 646        /* make sure mandatory rates are always added */
 647        sband = local->hw.wiphy->bands[band];
 648        sta->sta.supp_rates[band] = supp_rates |
 649                        ieee80211_mandatory_rates(sband, scan_width);
 650
 651        return ieee80211_ibss_finish_sta(sta);
 652}
 653
 654static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 655{
 656        struct ieee80211_local *local = sdata->local;
 657        int active = 0;
 658        struct sta_info *sta;
 659
 660        sdata_assert_lock(sdata);
 661
 662        rcu_read_lock();
 663
 664        list_for_each_entry_rcu(sta, &local->sta_list, list) {
 665                if (sta->sdata == sdata &&
 666                    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 667                               jiffies)) {
 668                        active++;
 669                        break;
 670                }
 671        }
 672
 673        rcu_read_unlock();
 674
 675        return active;
 676}
 677
 678static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
 679{
 680        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 681        struct ieee80211_local *local = sdata->local;
 682        struct cfg80211_bss *cbss;
 683        struct beacon_data *presp;
 684        struct sta_info *sta;
 685        u16 capability;
 686
 687        if (!is_zero_ether_addr(ifibss->bssid)) {
 688                capability = WLAN_CAPABILITY_IBSS;
 689
 690                if (ifibss->privacy)
 691                        capability |= WLAN_CAPABILITY_PRIVACY;
 692
 693                cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
 694                                        ifibss->bssid, ifibss->ssid,
 695                                        ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 696                                        WLAN_CAPABILITY_PRIVACY,
 697                                        capability);
 698
 699                if (cbss) {
 700                        cfg80211_unlink_bss(local->hw.wiphy, cbss);
 701                        cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 702                }
 703        }
 704
 705        ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 706
 707        sta_info_flush(sdata);
 708
 709        spin_lock_bh(&ifibss->incomplete_lock);
 710        while (!list_empty(&ifibss->incomplete_stations)) {
 711                sta = list_first_entry(&ifibss->incomplete_stations,
 712                                       struct sta_info, list);
 713                list_del(&sta->list);
 714                spin_unlock_bh(&ifibss->incomplete_lock);
 715
 716                sta_info_free(local, sta);
 717                spin_lock_bh(&ifibss->incomplete_lock);
 718        }
 719        spin_unlock_bh(&ifibss->incomplete_lock);
 720
 721        netif_carrier_off(sdata->dev);
 722
 723        sdata->vif.bss_conf.ibss_joined = false;
 724        sdata->vif.bss_conf.ibss_creator = false;
 725        sdata->vif.bss_conf.enable_beacon = false;
 726        sdata->vif.bss_conf.ssid_len = 0;
 727
 728        /* remove beacon */
 729        presp = rcu_dereference_protected(ifibss->presp,
 730                                          lockdep_is_held(&sdata->wdev.mtx));
 731        RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
 732        if (presp)
 733                kfree_rcu(presp, rcu_head);
 734
 735        clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
 736        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 737                                                BSS_CHANGED_IBSS);
 738        drv_leave_ibss(local, sdata);
 739        mutex_lock(&local->mtx);
 740        ieee80211_vif_release_channel(sdata);
 741        mutex_unlock(&local->mtx);
 742}
 743
 744static void ieee80211_csa_connection_drop_work(struct work_struct *work)
 745{
 746        struct ieee80211_sub_if_data *sdata =
 747                container_of(work, struct ieee80211_sub_if_data,
 748                             u.ibss.csa_connection_drop_work);
 749
 750        sdata_lock(sdata);
 751
 752        ieee80211_ibss_disconnect(sdata);
 753        synchronize_rcu();
 754        skb_queue_purge(&sdata->skb_queue);
 755
 756        /* trigger a scan to find another IBSS network to join */
 757        ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 758
 759        sdata_unlock(sdata);
 760}
 761
 762static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
 763{
 764        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 765        int err;
 766
 767        /* if the current channel is a DFS channel, mark the channel as
 768         * unavailable.
 769         */
 770        err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 771                                            &ifibss->chandef,
 772                                            NL80211_IFTYPE_ADHOC);
 773        if (err > 0)
 774                cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
 775                                     GFP_ATOMIC);
 776}
 777
 778static bool
 779ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 780                                  struct ieee802_11_elems *elems,
 781                                  bool beacon)
 782{
 783        struct cfg80211_csa_settings params;
 784        struct ieee80211_csa_ie csa_ie;
 785        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 786        enum nl80211_channel_type ch_type;
 787        int err;
 788        u32 sta_flags;
 789
 790        sdata_assert_lock(sdata);
 791
 792        sta_flags = IEEE80211_STA_DISABLE_VHT;
 793        switch (ifibss->chandef.width) {
 794        case NL80211_CHAN_WIDTH_5:
 795        case NL80211_CHAN_WIDTH_10:
 796        case NL80211_CHAN_WIDTH_20_NOHT:
 797                sta_flags |= IEEE80211_STA_DISABLE_HT;
 798                /* fall through */
 799        case NL80211_CHAN_WIDTH_20:
 800                sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
 801                break;
 802        default:
 803                break;
 804        }
 805
 806        memset(&params, 0, sizeof(params));
 807        memset(&csa_ie, 0, sizeof(csa_ie));
 808        err = ieee80211_parse_ch_switch_ie(sdata, elems,
 809                                           ifibss->chandef.chan->band,
 810                                           sta_flags, ifibss->bssid, &csa_ie);
 811        /* can't switch to destination channel, fail */
 812        if (err < 0)
 813                goto disconnect;
 814
 815        /* did not contain a CSA */
 816        if (err)
 817                return false;
 818
 819        /* channel switch is not supported, disconnect */
 820        if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
 821                goto disconnect;
 822
 823        params.count = csa_ie.count;
 824        params.chandef = csa_ie.chandef;
 825
 826        switch (ifibss->chandef.width) {
 827        case NL80211_CHAN_WIDTH_20_NOHT:
 828        case NL80211_CHAN_WIDTH_20:
 829        case NL80211_CHAN_WIDTH_40:
 830                /* keep our current HT mode (HT20/HT40+/HT40-), even if
 831                 * another mode  has been announced. The mode is not adopted
 832                 * within the beacon while doing CSA and we should therefore
 833                 * keep the mode which we announce.
 834                 */
 835                ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
 836                cfg80211_chandef_create(&params.chandef, params.chandef.chan,
 837                                        ch_type);
 838                break;
 839        case NL80211_CHAN_WIDTH_5:
 840        case NL80211_CHAN_WIDTH_10:
 841                if (params.chandef.width != ifibss->chandef.width) {
 842                        sdata_info(sdata,
 843                                   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
 844                                   ifibss->bssid,
 845                                   params.chandef.chan->center_freq,
 846                                   params.chandef.width,
 847                                   params.chandef.center_freq1,
 848                                   params.chandef.center_freq2);
 849                        goto disconnect;
 850                }
 851                break;
 852        default:
 853                /* should not happen, sta_flags should prevent VHT modes. */
 854                WARN_ON(1);
 855                goto disconnect;
 856        }
 857
 858        if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
 859                                     NL80211_IFTYPE_ADHOC)) {
 860                sdata_info(sdata,
 861                           "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
 862                           ifibss->bssid,
 863                           params.chandef.chan->center_freq,
 864                           params.chandef.width,
 865                           params.chandef.center_freq1,
 866                           params.chandef.center_freq2);
 867                goto disconnect;
 868        }
 869
 870        err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 871                                            &params.chandef,
 872                                            NL80211_IFTYPE_ADHOC);
 873        if (err < 0)
 874                goto disconnect;
 875        if (err > 0 && !ifibss->userspace_handles_dfs) {
 876                /* IBSS-DFS only allowed with a control program */
 877                goto disconnect;
 878        }
 879
 880        params.radar_required = err;
 881
 882        if (cfg80211_chandef_identical(&params.chandef,
 883                                       &sdata->vif.bss_conf.chandef)) {
 884                ibss_dbg(sdata,
 885                         "received csa with an identical chandef, ignoring\n");
 886                return true;
 887        }
 888
 889        /* all checks done, now perform the channel switch. */
 890        ibss_dbg(sdata,
 891                 "received channel switch announcement to go to channel %d MHz\n",
 892                 params.chandef.chan->center_freq);
 893
 894        params.block_tx = !!csa_ie.mode;
 895
 896        if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
 897                                     &params))
 898                goto disconnect;
 899
 900        ieee80211_ibss_csa_mark_radar(sdata);
 901
 902        return true;
 903disconnect:
 904        ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
 905        ieee80211_queue_work(&sdata->local->hw,
 906                             &ifibss->csa_connection_drop_work);
 907
 908        ieee80211_ibss_csa_mark_radar(sdata);
 909
 910        return true;
 911}
 912
 913static void
 914ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
 915                                struct ieee80211_mgmt *mgmt, size_t len,
 916                                struct ieee80211_rx_status *rx_status,
 917                                struct ieee802_11_elems *elems)
 918{
 919        int required_len;
 920
 921        if (len < IEEE80211_MIN_ACTION_SIZE + 1)
 922                return;
 923
 924        /* CSA is the only action we handle for now */
 925        if (mgmt->u.action.u.measurement.action_code !=
 926            WLAN_ACTION_SPCT_CHL_SWITCH)
 927                return;
 928
 929        required_len = IEEE80211_MIN_ACTION_SIZE +
 930                       sizeof(mgmt->u.action.u.chan_switch);
 931        if (len < required_len)
 932                return;
 933
 934        if (!sdata->vif.csa_active)
 935                ieee80211_ibss_process_chanswitch(sdata, elems, false);
 936}
 937
 938static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
 939                                          struct ieee80211_mgmt *mgmt,
 940                                          size_t len)
 941{
 942        u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
 943
 944        if (len < IEEE80211_DEAUTH_FRAME_LEN)
 945                return;
 946
 947        ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
 948                 mgmt->sa, mgmt->da, mgmt->bssid, reason);
 949        sta_info_destroy_addr(sdata, mgmt->sa);
 950}
 951
 952static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
 953                                        struct ieee80211_mgmt *mgmt,
 954                                        size_t len)
 955{
 956        u16 auth_alg, auth_transaction;
 957
 958        sdata_assert_lock(sdata);
 959
 960        if (len < 24 + 6)
 961                return;
 962
 963        auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
 964        auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
 965
 966        ibss_dbg(sdata,
 967                 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
 968                 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
 969
 970        if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
 971                return;
 972
 973        /*
 974         * IEEE 802.11 standard does not require authentication in IBSS
 975         * networks and most implementations do not seem to use it.
 976         * However, try to reply to authentication attempts if someone
 977         * has actually implemented this.
 978         */
 979        ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
 980                            mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
 981}
 982
 983static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 984                                  struct ieee80211_mgmt *mgmt, size_t len,
 985                                  struct ieee80211_rx_status *rx_status,
 986                                  struct ieee802_11_elems *elems)
 987{
 988        struct ieee80211_local *local = sdata->local;
 989        struct cfg80211_bss *cbss;
 990        struct ieee80211_bss *bss;
 991        struct sta_info *sta;
 992        struct ieee80211_channel *channel;
 993        u64 beacon_timestamp, rx_timestamp;
 994        u32 supp_rates = 0;
 995        enum ieee80211_band band = rx_status->band;
 996        enum nl80211_bss_scan_width scan_width;
 997        struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 998        bool rates_updated = false;
 999
1000        channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1001        if (!channel)
1002                return;
1003
1004        if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
1005            ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
1006
1007                rcu_read_lock();
1008                sta = sta_info_get(sdata, mgmt->sa);
1009
1010                if (elems->supp_rates) {
1011                        supp_rates = ieee80211_sta_get_rates(sdata, elems,
1012                                                             band, NULL);
1013                        if (sta) {
1014                                u32 prev_rates;
1015
1016                                prev_rates = sta->sta.supp_rates[band];
1017                                /* make sure mandatory rates are always added */
1018                                scan_width = NL80211_BSS_CHAN_WIDTH_20;
1019                                if (rx_status->flag & RX_FLAG_5MHZ)
1020                                        scan_width = NL80211_BSS_CHAN_WIDTH_5;
1021                                if (rx_status->flag & RX_FLAG_10MHZ)
1022                                        scan_width = NL80211_BSS_CHAN_WIDTH_10;
1023
1024                                sta->sta.supp_rates[band] = supp_rates |
1025                                        ieee80211_mandatory_rates(sband,
1026                                                                  scan_width);
1027                                if (sta->sta.supp_rates[band] != prev_rates) {
1028                                        ibss_dbg(sdata,
1029                                                 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1030                                                 sta->sta.addr, prev_rates,
1031                                                 sta->sta.supp_rates[band]);
1032                                        rates_updated = true;
1033                                }
1034                        } else {
1035                                rcu_read_unlock();
1036                                sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1037                                                mgmt->sa, supp_rates);
1038                        }
1039                }
1040
1041                if (sta && elems->wmm_info)
1042                        sta->sta.wme = true;
1043
1044                if (sta && elems->ht_operation && elems->ht_cap_elem &&
1045                    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1046                    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1047                    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1048                        /* we both use HT */
1049                        struct ieee80211_ht_cap htcap_ie;
1050                        struct cfg80211_chan_def chandef;
1051
1052                        ieee80211_ht_oper_to_chandef(channel,
1053                                                     elems->ht_operation,
1054                                                     &chandef);
1055
1056                        memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1057
1058                        /*
1059                         * fall back to HT20 if we don't use or use
1060                         * the other extension channel
1061                         */
1062                        if (chandef.center_freq1 !=
1063                            sdata->u.ibss.chandef.center_freq1)
1064                                htcap_ie.cap_info &=
1065                                        cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
1066
1067                        rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
1068                                                sdata, sband, &htcap_ie, sta);
1069                }
1070
1071                if (sta && rates_updated) {
1072                        u32 changed = IEEE80211_RC_SUPP_RATES_CHANGED;
1073                        u8 rx_nss = sta->sta.rx_nss;
1074
1075                        /* Force rx_nss recalculation */
1076                        sta->sta.rx_nss = 0;
1077                        rate_control_rate_init(sta);
1078                        if (sta->sta.rx_nss != rx_nss)
1079                                changed |= IEEE80211_RC_NSS_CHANGED;
1080
1081                        drv_sta_rc_update(local, sdata, &sta->sta, changed);
1082                }
1083
1084                rcu_read_unlock();
1085        }
1086
1087        bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
1088                                        channel);
1089        if (!bss)
1090                return;
1091
1092        cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1093
1094        /* same for beacon and probe response */
1095        beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1096
1097        /* check if we need to merge IBSS */
1098
1099        /* not an IBSS */
1100        if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1101                goto put_bss;
1102
1103        /* different channel */
1104        if (sdata->u.ibss.fixed_channel &&
1105            sdata->u.ibss.chandef.chan != cbss->channel)
1106                goto put_bss;
1107
1108        /* different SSID */
1109        if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1110            memcmp(elems->ssid, sdata->u.ibss.ssid,
1111                                sdata->u.ibss.ssid_len))
1112                goto put_bss;
1113
1114        /* process channel switch */
1115        if (sdata->vif.csa_active ||
1116            ieee80211_ibss_process_chanswitch(sdata, elems, true))
1117                goto put_bss;
1118
1119        /* same BSSID */
1120        if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1121                goto put_bss;
1122
1123        /* we use a fixed BSSID */
1124        if (sdata->u.ibss.fixed_bssid)
1125                goto put_bss;
1126
1127        if (ieee80211_have_rx_timestamp(rx_status)) {
1128                /* time when timestamp field was received */
1129                rx_timestamp =
1130                        ieee80211_calculate_rx_timestamp(local, rx_status,
1131                                                         len + FCS_LEN, 24);
1132        } else {
1133                /*
1134                 * second best option: get current TSF
1135                 * (will return -1 if not supported)
1136                 */
1137                rx_timestamp = drv_get_tsf(local, sdata);
1138        }
1139
1140        ibss_dbg(sdata,
1141                 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
1142                 mgmt->sa, mgmt->bssid,
1143                 (unsigned long long)rx_timestamp,
1144                 (unsigned long long)beacon_timestamp,
1145                 (unsigned long long)(rx_timestamp - beacon_timestamp),
1146                 jiffies);
1147
1148        if (beacon_timestamp > rx_timestamp) {
1149                ibss_dbg(sdata,
1150                         "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1151                         mgmt->bssid);
1152                ieee80211_sta_join_ibss(sdata, bss);
1153                supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1154                ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1155                                       supp_rates);
1156                rcu_read_unlock();
1157        }
1158
1159 put_bss:
1160        ieee80211_rx_bss_put(local, bss);
1161}
1162
1163void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1164                              const u8 *bssid, const u8 *addr,
1165                              u32 supp_rates)
1166{
1167        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1168        struct ieee80211_local *local = sdata->local;
1169        struct sta_info *sta;
1170        struct ieee80211_chanctx_conf *chanctx_conf;
1171        struct ieee80211_supported_band *sband;
1172        enum nl80211_bss_scan_width scan_width;
1173        int band;
1174
1175        /*
1176         * XXX: Consider removing the least recently used entry and
1177         *      allow new one to be added.
1178         */
1179        if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1180                net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1181                                    sdata->name, addr);
1182                return;
1183        }
1184
1185        if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1186                return;
1187
1188        if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1189                return;
1190
1191        rcu_read_lock();
1192        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1193        if (WARN_ON_ONCE(!chanctx_conf)) {
1194                rcu_read_unlock();
1195                return;
1196        }
1197        band = chanctx_conf->def.chan->band;
1198        scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1199        rcu_read_unlock();
1200
1201        sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1202        if (!sta)
1203                return;
1204
1205        sta->last_rx = jiffies;
1206
1207        /* make sure mandatory rates are always added */
1208        sband = local->hw.wiphy->bands[band];
1209        sta->sta.supp_rates[band] = supp_rates |
1210                        ieee80211_mandatory_rates(sband, scan_width);
1211
1212        spin_lock(&ifibss->incomplete_lock);
1213        list_add(&sta->list, &ifibss->incomplete_stations);
1214        spin_unlock(&ifibss->incomplete_lock);
1215        ieee80211_queue_work(&local->hw, &sdata->work);
1216}
1217
1218static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1219{
1220        struct ieee80211_local *local = sdata->local;
1221        struct sta_info *sta, *tmp;
1222        unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1223        unsigned long exp_rsn_time = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1224
1225        mutex_lock(&local->sta_mtx);
1226
1227        list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1228                if (sdata != sta->sdata)
1229                        continue;
1230
1231                if (time_after(jiffies, sta->last_rx + exp_time) ||
1232                    (time_after(jiffies, sta->last_rx + exp_rsn_time) &&
1233                     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1234                        sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1235                                sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1236                                "not authorized " : "", sta->sta.addr);
1237
1238                        WARN_ON(__sta_info_destroy(sta));
1239                }
1240        }
1241
1242        mutex_unlock(&local->sta_mtx);
1243}
1244
1245/*
1246 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1247 */
1248
1249static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1250{
1251        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1252        enum nl80211_bss_scan_width scan_width;
1253
1254        sdata_assert_lock(sdata);
1255
1256        mod_timer(&ifibss->timer,
1257                  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1258
1259        ieee80211_ibss_sta_expire(sdata);
1260
1261        if (time_before(jiffies, ifibss->last_scan_completed +
1262                       IEEE80211_IBSS_MERGE_INTERVAL))
1263                return;
1264
1265        if (ieee80211_sta_active_ibss(sdata))
1266                return;
1267
1268        if (ifibss->fixed_channel)
1269                return;
1270
1271        sdata_info(sdata,
1272                   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1273
1274        scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1275        ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1276                                    NULL, scan_width);
1277}
1278
1279static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1280{
1281        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1282        u8 bssid[ETH_ALEN];
1283        u16 capability;
1284        int i;
1285
1286        sdata_assert_lock(sdata);
1287
1288        if (ifibss->fixed_bssid) {
1289                memcpy(bssid, ifibss->bssid, ETH_ALEN);
1290        } else {
1291                /* Generate random, not broadcast, locally administered BSSID. Mix in
1292                 * own MAC address to make sure that devices that do not have proper
1293                 * random number generator get different BSSID. */
1294                get_random_bytes(bssid, ETH_ALEN);
1295                for (i = 0; i < ETH_ALEN; i++)
1296                        bssid[i] ^= sdata->vif.addr[i];
1297                bssid[0] &= ~0x01;
1298                bssid[0] |= 0x02;
1299        }
1300
1301        sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1302
1303        capability = WLAN_CAPABILITY_IBSS;
1304
1305        if (ifibss->privacy)
1306                capability |= WLAN_CAPABILITY_PRIVACY;
1307        else
1308                sdata->drop_unencrypted = 0;
1309
1310        __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1311                                  &ifibss->chandef, ifibss->basic_rates,
1312                                  capability, 0, true);
1313}
1314
1315/*
1316 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1317 */
1318
1319static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1320{
1321        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1322        struct ieee80211_local *local = sdata->local;
1323        struct cfg80211_bss *cbss;
1324        struct ieee80211_channel *chan = NULL;
1325        const u8 *bssid = NULL;
1326        enum nl80211_bss_scan_width scan_width;
1327        int active_ibss;
1328        u16 capability;
1329
1330        sdata_assert_lock(sdata);
1331
1332        active_ibss = ieee80211_sta_active_ibss(sdata);
1333        ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1334
1335        if (active_ibss)
1336                return;
1337
1338        capability = WLAN_CAPABILITY_IBSS;
1339        if (ifibss->privacy)
1340                capability |= WLAN_CAPABILITY_PRIVACY;
1341        if (ifibss->fixed_bssid)
1342                bssid = ifibss->bssid;
1343        if (ifibss->fixed_channel)
1344                chan = ifibss->chandef.chan;
1345        if (!is_zero_ether_addr(ifibss->bssid))
1346                bssid = ifibss->bssid;
1347        cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1348                                ifibss->ssid, ifibss->ssid_len,
1349                                WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
1350                                capability);
1351
1352        if (cbss) {
1353                struct ieee80211_bss *bss;
1354
1355                bss = (void *)cbss->priv;
1356                ibss_dbg(sdata,
1357                         "sta_find_ibss: selected %pM current %pM\n",
1358                         cbss->bssid, ifibss->bssid);
1359                sdata_info(sdata,
1360                           "Selected IBSS BSSID %pM based on configured SSID\n",
1361                           cbss->bssid);
1362
1363                ieee80211_sta_join_ibss(sdata, bss);
1364                ieee80211_rx_bss_put(local, bss);
1365                return;
1366        }
1367
1368        /* if a fixed bssid and a fixed freq have been provided create the IBSS
1369         * directly and do not waste time scanning
1370         */
1371        if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1372                sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1373                           bssid);
1374                ieee80211_sta_create_ibss(sdata);
1375                return;
1376        }
1377
1378
1379        ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1380
1381        /* Selected IBSS not found in current scan results - try to scan */
1382        if (time_after(jiffies, ifibss->last_scan_completed +
1383                                        IEEE80211_SCAN_INTERVAL)) {
1384                sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1385
1386                scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1387                ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1388                                            ifibss->ssid_len, chan,
1389                                            scan_width);
1390        } else {
1391                int interval = IEEE80211_SCAN_INTERVAL;
1392
1393                if (time_after(jiffies, ifibss->ibss_join_req +
1394                               IEEE80211_IBSS_JOIN_TIMEOUT))
1395                        ieee80211_sta_create_ibss(sdata);
1396
1397                mod_timer(&ifibss->timer,
1398                          round_jiffies(jiffies + interval));
1399        }
1400}
1401
1402static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1403                                        struct sk_buff *req)
1404{
1405        struct ieee80211_mgmt *mgmt = (void *)req->data;
1406        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1407        struct ieee80211_local *local = sdata->local;
1408        int tx_last_beacon, len = req->len;
1409        struct sk_buff *skb;
1410        struct beacon_data *presp;
1411        u8 *pos, *end;
1412
1413        sdata_assert_lock(sdata);
1414
1415        presp = rcu_dereference_protected(ifibss->presp,
1416                                          lockdep_is_held(&sdata->wdev.mtx));
1417
1418        if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1419            len < 24 + 2 || !presp)
1420                return;
1421
1422        tx_last_beacon = drv_tx_last_beacon(local);
1423
1424        ibss_dbg(sdata,
1425                 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
1426                 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
1427
1428        if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1429                return;
1430
1431        if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1432            !is_broadcast_ether_addr(mgmt->bssid))
1433                return;
1434
1435        end = ((u8 *) mgmt) + len;
1436        pos = mgmt->u.probe_req.variable;
1437        if (pos[0] != WLAN_EID_SSID ||
1438            pos + 2 + pos[1] > end) {
1439                ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1440                         mgmt->sa);
1441                return;
1442        }
1443        if (pos[1] != 0 &&
1444            (pos[1] != ifibss->ssid_len ||
1445             memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1446                /* Ignore ProbeReq for foreign SSID */
1447                return;
1448        }
1449
1450        /* Reply with ProbeResp */
1451        skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1452        if (!skb)
1453                return;
1454
1455        skb_reserve(skb, local->tx_headroom);
1456        memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
1457
1458        memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1459        ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1460        IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1461
1462        /* avoid excessive retries for probe request to wildcard SSIDs */
1463        if (pos[1] == 0)
1464                IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1465
1466        ieee80211_tx_skb(sdata, skb);
1467}
1468
1469static
1470void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1471                                    struct ieee80211_mgmt *mgmt, size_t len,
1472                                    struct ieee80211_rx_status *rx_status)
1473{
1474        size_t baselen;
1475        struct ieee802_11_elems elems;
1476
1477        BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1478                     offsetof(typeof(mgmt->u.beacon), variable));
1479
1480        /*
1481         * either beacon or probe_resp but the variable field is at the
1482         * same offset
1483         */
1484        baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1485        if (baselen > len)
1486                return;
1487
1488        ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1489                               false, &elems);
1490
1491        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
1492}
1493
1494void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1495                                   struct sk_buff *skb)
1496{
1497        struct ieee80211_rx_status *rx_status;
1498        struct ieee80211_mgmt *mgmt;
1499        u16 fc;
1500        struct ieee802_11_elems elems;
1501        int ies_len;
1502
1503        rx_status = IEEE80211_SKB_RXCB(skb);
1504        mgmt = (struct ieee80211_mgmt *) skb->data;
1505        fc = le16_to_cpu(mgmt->frame_control);
1506
1507        sdata_lock(sdata);
1508
1509        if (!sdata->u.ibss.ssid_len)
1510                goto mgmt_out; /* not ready to merge yet */
1511
1512        switch (fc & IEEE80211_FCTL_STYPE) {
1513        case IEEE80211_STYPE_PROBE_REQ:
1514                ieee80211_rx_mgmt_probe_req(sdata, skb);
1515                break;
1516        case IEEE80211_STYPE_PROBE_RESP:
1517        case IEEE80211_STYPE_BEACON:
1518                ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1519                                               rx_status);
1520                break;
1521        case IEEE80211_STYPE_AUTH:
1522                ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1523                break;
1524        case IEEE80211_STYPE_DEAUTH:
1525                ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1526                break;
1527        case IEEE80211_STYPE_ACTION:
1528                switch (mgmt->u.action.category) {
1529                case WLAN_CATEGORY_SPECTRUM_MGMT:
1530                        ies_len = skb->len -
1531                                  offsetof(struct ieee80211_mgmt,
1532                                           u.action.u.chan_switch.variable);
1533
1534                        if (ies_len < 0)
1535                                break;
1536
1537                        ieee802_11_parse_elems(
1538                                mgmt->u.action.u.chan_switch.variable,
1539                                ies_len, true, &elems);
1540
1541                        if (elems.parse_error)
1542                                break;
1543
1544                        ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
1545                                                        rx_status, &elems);
1546                        break;
1547                }
1548        }
1549
1550 mgmt_out:
1551        sdata_unlock(sdata);
1552}
1553
1554void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1555{
1556        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1557        struct sta_info *sta;
1558
1559        sdata_lock(sdata);
1560
1561        /*
1562         * Work could be scheduled after scan or similar
1563         * when we aren't even joined (or trying) with a
1564         * network.
1565         */
1566        if (!ifibss->ssid_len)
1567                goto out;
1568
1569        spin_lock_bh(&ifibss->incomplete_lock);
1570        while (!list_empty(&ifibss->incomplete_stations)) {
1571                sta = list_first_entry(&ifibss->incomplete_stations,
1572                                       struct sta_info, list);
1573                list_del(&sta->list);
1574                spin_unlock_bh(&ifibss->incomplete_lock);
1575
1576                ieee80211_ibss_finish_sta(sta);
1577                rcu_read_unlock();
1578                spin_lock_bh(&ifibss->incomplete_lock);
1579        }
1580        spin_unlock_bh(&ifibss->incomplete_lock);
1581
1582        switch (ifibss->state) {
1583        case IEEE80211_IBSS_MLME_SEARCH:
1584                ieee80211_sta_find_ibss(sdata);
1585                break;
1586        case IEEE80211_IBSS_MLME_JOINED:
1587                ieee80211_sta_merge_ibss(sdata);
1588                break;
1589        default:
1590                WARN_ON(1);
1591                break;
1592        }
1593
1594 out:
1595        sdata_unlock(sdata);
1596}
1597
1598static void ieee80211_ibss_timer(unsigned long data)
1599{
1600        struct ieee80211_sub_if_data *sdata =
1601                (struct ieee80211_sub_if_data *) data;
1602
1603        ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1604}
1605
1606void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1607{
1608        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1609
1610        setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1611                    (unsigned long) sdata);
1612        INIT_LIST_HEAD(&ifibss->incomplete_stations);
1613        spin_lock_init(&ifibss->incomplete_lock);
1614        INIT_WORK(&ifibss->csa_connection_drop_work,
1615                  ieee80211_csa_connection_drop_work);
1616}
1617
1618/* scan finished notification */
1619void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1620{
1621        struct ieee80211_sub_if_data *sdata;
1622
1623        mutex_lock(&local->iflist_mtx);
1624        list_for_each_entry(sdata, &local->interfaces, list) {
1625                if (!ieee80211_sdata_running(sdata))
1626                        continue;
1627                if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1628                        continue;
1629                sdata->u.ibss.last_scan_completed = jiffies;
1630                ieee80211_queue_work(&local->hw, &sdata->work);
1631        }
1632        mutex_unlock(&local->iflist_mtx);
1633}
1634
1635int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1636                        struct cfg80211_ibss_params *params)
1637{
1638        u32 changed = 0;
1639        u32 rate_flags;
1640        struct ieee80211_supported_band *sband;
1641        enum ieee80211_chanctx_mode chanmode;
1642        struct ieee80211_local *local = sdata->local;
1643        int radar_detect_width = 0;
1644        int i;
1645        int ret;
1646
1647        ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1648                                            &params->chandef,
1649                                            sdata->wdev.iftype);
1650        if (ret < 0)
1651                return ret;
1652
1653        if (ret > 0) {
1654                if (!params->userspace_handles_dfs)
1655                        return -EINVAL;
1656                radar_detect_width = BIT(params->chandef.width);
1657        }
1658
1659        chanmode = (params->channel_fixed && !ret) ?
1660                IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1661
1662        mutex_lock(&local->chanctx_mtx);
1663        ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1664                                           radar_detect_width);
1665        mutex_unlock(&local->chanctx_mtx);
1666        if (ret < 0)
1667                return ret;
1668
1669        if (params->bssid) {
1670                memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1671                sdata->u.ibss.fixed_bssid = true;
1672        } else
1673                sdata->u.ibss.fixed_bssid = false;
1674
1675        sdata->u.ibss.privacy = params->privacy;
1676        sdata->u.ibss.control_port = params->control_port;
1677        sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1678        sdata->u.ibss.basic_rates = params->basic_rates;
1679        sdata->u.ibss.last_scan_completed = jiffies;
1680
1681        /* fix basic_rates if channel does not support these rates */
1682        rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1683        sband = local->hw.wiphy->bands[params->chandef.chan->band];
1684        for (i = 0; i < sband->n_bitrates; i++) {
1685                if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1686                        sdata->u.ibss.basic_rates &= ~BIT(i);
1687        }
1688        memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1689               sizeof(params->mcast_rate));
1690
1691        sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1692
1693        sdata->u.ibss.chandef = params->chandef;
1694        sdata->u.ibss.fixed_channel = params->channel_fixed;
1695
1696        if (params->ie) {
1697                sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1698                                           GFP_KERNEL);
1699                if (sdata->u.ibss.ie)
1700                        sdata->u.ibss.ie_len = params->ie_len;
1701        }
1702
1703        sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1704        sdata->u.ibss.ibss_join_req = jiffies;
1705
1706        memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1707        sdata->u.ibss.ssid_len = params->ssid_len;
1708
1709        memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1710               sizeof(sdata->u.ibss.ht_capa));
1711        memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1712               sizeof(sdata->u.ibss.ht_capa_mask));
1713
1714        /*
1715         * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1716         * reserved, but an HT STA shall protect HT transmissions as though
1717         * the HT Protection field were set to non-HT mixed mode.
1718         *
1719         * In an IBSS, the RIFS Mode field of the HT Operation element is
1720         * also reserved, but an HT STA shall operate as though this field
1721         * were set to 1.
1722         */
1723
1724        sdata->vif.bss_conf.ht_operation_mode |=
1725                  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1726                | IEEE80211_HT_PARAM_RIFS_MODE;
1727
1728        changed |= BSS_CHANGED_HT;
1729        ieee80211_bss_info_change_notify(sdata, changed);
1730
1731        sdata->smps_mode = IEEE80211_SMPS_OFF;
1732        sdata->needed_rx_chains = local->rx_chains;
1733
1734        ieee80211_queue_work(&local->hw, &sdata->work);
1735
1736        return 0;
1737}
1738
1739int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1740{
1741        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1742
1743        ieee80211_ibss_disconnect(sdata);
1744        ifibss->ssid_len = 0;
1745        memset(ifibss->bssid, 0, ETH_ALEN);
1746
1747        /* remove beacon */
1748        kfree(sdata->u.ibss.ie);
1749
1750        /* on the next join, re-program HT parameters */
1751        memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1752        memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1753
1754        synchronize_rcu();
1755
1756        skb_queue_purge(&sdata->skb_queue);
1757
1758        del_timer_sync(&sdata->u.ibss.timer);
1759
1760        return 0;
1761}
1762