Pileus Git - ~andy/linux/blob - 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 #define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
  34
  35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  36
  37 static struct beacon_data *
  38 ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
  39                            const int beacon_int, const u32 basic_rates,
  40                            const u16 capability, u64 tsf,
  41                            struct cfg80211_chan_def *chandef,
  42                            bool *have_higher_than_11mbit,
  43                            struct cfg80211_csa_settings *csa_settings)
  44 {
  45         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  46         struct ieee80211_local *local = sdata->local;
  47         int rates_n = 0, i, ri;
  48         struct ieee80211_mgmt *mgmt;
  49         u8 *pos;
  50         struct ieee80211_supported_band *sband;
  51         u32 rate_flags, rates = 0, rates_added = 0;
  52         struct beacon_data *presp;
  53         int frame_len;
  54         int shift;
  55
  56         /* Build IBSS probe response */
  57         frame_len = sizeof(struct ieee80211_hdr_3addr) +
  58                     12 /* struct ieee80211_mgmt.u.beacon */ +
  59                     2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
  60                     2 + 8 /* max Supported Rates */ +
  61                     3 /* max DS params */ +
  62                     4 /* IBSS params */ +
  63                     5 /* Channel Switch Announcement */ +
  64                     2 + (IEEE80211_MAX_SUPP_RATES - 8) +
  65                     2 + sizeof(struct ieee80211_ht_cap) +
  66                     2 + sizeof(struct ieee80211_ht_operation) +
  67                     ifibss->ie_len;
  68         presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
  69         if (!presp)
  70                 return NULL;
  71
  72         presp->head = (void *)(presp + 1);
  73
  74         mgmt = (void *) presp->head;
  75         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  76                                           IEEE80211_STYPE_PROBE_RESP);
  77         eth_broadcast_addr(mgmt->da);
  78         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  79         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
  80         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
  81         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
  82         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
  83
  84         pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
  85
  86         *pos++ = WLAN_EID_SSID;
  87         *pos++ = ifibss->ssid_len;
  88         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
  89         pos += ifibss->ssid_len;
  90
  91         sband = local->hw.wiphy->bands[chandef->chan->band];
  92         rate_flags = ieee80211_chandef_rate_flags(chandef);
  93         shift = ieee80211_chandef_get_shift(chandef);
  94         rates_n = 0;
  95         if (have_higher_than_11mbit)
  96                 *have_higher_than_11mbit = false;
  97
  98         for (i = 0; i < sband->n_bitrates; i++) {
  99                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 100                         continue;
 101                 if (sband->bitrates[i].bitrate > 110 &&
 102                     have_higher_than_11mbit)
 103                         *have_higher_than_11mbit = true;
 104
 105                 rates |= BIT(i);
 106                 rates_n++;
 107         }
 108
 109         *pos++ = WLAN_EID_SUPP_RATES;
 110         *pos++ = min_t(int, 8, rates_n);
 111         for (ri = 0; ri < sband->n_bitrates; ri++) {
 112                 int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
 113                                         5 * (1 << shift));
 114                 u8 basic = 0;
 115                 if (!(rates & BIT(ri)))
 116                         continue;
 117
 118                 if (basic_rates & BIT(ri))
 119                         basic = 0x80;
 120                 *pos++ = basic | (u8) rate;
 121                 if (++rates_added == 8) {
 122                         ri++; /* continue at next rate for EXT_SUPP_RATES */
 123                         break;
 124                 }
 125         }
 126
 127         if (sband->band == IEEE80211_BAND_2GHZ) {
 128                 *pos++ = WLAN_EID_DS_PARAMS;
 129                 *pos++ = 1;
 130                 *pos++ = ieee80211_frequency_to_channel(
 131                                 chandef->chan->center_freq);
 132         }
 133
 134         *pos++ = WLAN_EID_IBSS_PARAMS;
 135         *pos++ = 2;
 136         /* FIX: set ATIM window based on scan results */
 137         *pos++ = 0;
 138         *pos++ = 0;
 139
 140         if (csa_settings) {
 141                 *pos++ = WLAN_EID_CHANNEL_SWITCH;
 142                 *pos++ = 3;
 143                 *pos++ = csa_settings->block_tx ? 1 : 0;
 144                 *pos++ = ieee80211_frequency_to_channel(
 145                                 csa_settings->chandef.chan->center_freq);
 146                 sdata->csa_counter_offset_beacon = (pos - presp->head);
 147                 *pos++ = csa_settings->count;
 148         }
 149
 150         /* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
 151         if (rates_n > 8) {
 152                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 153                 *pos++ = rates_n - 8;
 154                 for (; ri < sband->n_bitrates; ri++) {
 155                         int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
 156                                                 5 * (1 << shift));
 157                         u8 basic = 0;
 158                         if (!(rates & BIT(ri)))
 159                                 continue;
 160
 161                         if (basic_rates & BIT(ri))
 162                                 basic = 0x80;
 163                         *pos++ = basic | (u8) rate;
 164                 }
 165         }
 166
 167         if (ifibss->ie_len) {
 168                 memcpy(pos, ifibss->ie, ifibss->ie_len);
 169                 pos += ifibss->ie_len;
 170         }
 171
 172         /* add HT capability and information IEs */
 173         if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
 174             chandef->width != NL80211_CHAN_WIDTH_5 &&
 175             chandef->width != NL80211_CHAN_WIDTH_10 &&
 176             sband->ht_cap.ht_supported) {
 177                 struct ieee80211_sta_ht_cap ht_cap;
 178
 179                 memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
 180                 ieee80211_apply_htcap_overrides(sdata, &ht_cap);
 181
 182                 pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
 183                 /*
 184                  * Note: According to 802.11n-2009 9.13.3.1, HT Protection
 185                  * field and RIFS Mode are reserved in IBSS mode, therefore
 186                  * keep them at 0
 187                  */
 188                 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
 189                                                  chandef, 0);
 190         }
 191
 192         if (local->hw.queues >= IEEE80211_NUM_ACS) {
 193                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 194                 *pos++ = 7; /* len */
 195                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 196                 *pos++ = 0x50;
 197                 *pos++ = 0xf2;
 198                 *pos++ = 2; /* WME */
 199                 *pos++ = 0; /* WME info */
 200                 *pos++ = 1; /* WME ver */
 201                 *pos++ = 0; /* U-APSD no in use */
 202         }
 203
 204         presp->head_len = pos - presp->head;
 205         if (WARN_ON(presp->head_len > frame_len))
 206                 goto error;
 207
 208         return presp;
 209 error:
 210         kfree(presp);
 211         return NULL;
 212 }
 213
 214 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 215                                       const u8 *bssid, const int beacon_int,
 216                                       struct cfg80211_chan_def *req_chandef,
 217                                       const u32 basic_rates,
 218                                       const u16 capability, u64 tsf,
 219                                       bool creator)
 220 {
 221         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 222         struct ieee80211_local *local = sdata->local;
 223         struct ieee80211_supported_band *sband;
 224         struct ieee80211_mgmt *mgmt;
 225         struct cfg80211_bss *bss;
 226         u32 bss_change;
 227         struct cfg80211_chan_def chandef;
 228         struct ieee80211_channel *chan;
 229         struct beacon_data *presp;
 230         enum nl80211_bss_scan_width scan_width;
 231         bool have_higher_than_11mbit;
 232         bool radar_required = false;
 233         int err;
 234
 235         sdata_assert_lock(sdata);
 236
 237         /* Reset own TSF to allow time synchronization work. */
 238         drv_reset_tsf(local, sdata);
 239
 240         if (!ether_addr_equal(ifibss->bssid, bssid))
 241                 sta_info_flush(sdata);
 242
 243         /* if merging, indicate to driver that we leave the old IBSS */
 244         if (sdata->vif.bss_conf.ibss_joined) {
 245                 sdata->vif.bss_conf.ibss_joined = false;
 246                 sdata->vif.bss_conf.ibss_creator = false;
 247                 sdata->vif.bss_conf.enable_beacon = false;
 248                 netif_carrier_off(sdata->dev);
 249                 ieee80211_bss_info_change_notify(sdata,
 250                                                  BSS_CHANGED_IBSS |
 251                                                  BSS_CHANGED_BEACON_ENABLED);
 252                 drv_leave_ibss(local, sdata);
 253         }
 254
 255         presp = rcu_dereference_protected(ifibss->presp,
 256                                           lockdep_is_held(&sdata->wdev.mtx));
 257         rcu_assign_pointer(ifibss->presp, NULL);
 258         if (presp)
 259                 kfree_rcu(presp, rcu_head);
 260
 261         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 262
 263         /* make a copy of the chandef, it could be modified below. */
 264         chandef = *req_chandef;
 265         chan = chandef.chan;
 266         if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
 267                 if (chandef.width == NL80211_CHAN_WIDTH_5 ||
 268                     chandef.width == NL80211_CHAN_WIDTH_10 ||
 269                     chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
 270                     chandef.width == NL80211_CHAN_WIDTH_20) {
 271                         sdata_info(sdata,
 272                                    "Failed to join IBSS, beacons forbidden\n");
 273                         return;
 274                 }
 275                 chandef.width = NL80211_CHAN_WIDTH_20;
 276                 chandef.center_freq1 = chan->center_freq;
 277                 /* check again for downgraded chandef */
 278                 if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
 279                         sdata_info(sdata,
 280                                    "Failed to join IBSS, beacons forbidden\n");
 281                         return;
 282                 }
 283         }
 284
 285         err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 286                                             &chandef);
 287         if (err > 0) {
 288                 if (!ifibss->userspace_handles_dfs) {
 289                         sdata_info(sdata,
 290                                    "Failed to join IBSS, DFS channel without control program\n");
 291                         return;
 292                 }
 293                 radar_required = true;
 294         }
 295
 296         mutex_lock(&local->mtx);
 297         ieee80211_vif_release_channel(sdata);
 298         if (ieee80211_vif_use_channel(sdata, &chandef,
 299                                       ifibss->fixed_channel ?
 300                                         IEEE80211_CHANCTX_SHARED :
 301                                         IEEE80211_CHANCTX_EXCLUSIVE)) {
 302                 sdata_info(sdata, "Failed to join IBSS, no channel context\n");
 303                 mutex_unlock(&local->mtx);
 304                 return;
 305         }
 306         mutex_unlock(&local->mtx);
 307
 308         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 309
 310         sband = local->hw.wiphy->bands[chan->band];
 311
 312         presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
 313                                            capability, tsf, &chandef,
 314                                            &have_higher_than_11mbit, NULL);
 315         if (!presp)
 316                 return;
 317
 318         rcu_assign_pointer(ifibss->presp, presp);
 319         mgmt = (void *)presp->head;
 320
 321         sdata->radar_required = radar_required;
 322         sdata->vif.bss_conf.enable_beacon = true;
 323         sdata->vif.bss_conf.beacon_int = beacon_int;
 324         sdata->vif.bss_conf.basic_rates = basic_rates;
 325         sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
 326         memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
 327         bss_change = BSS_CHANGED_BEACON_INT;
 328         bss_change |= ieee80211_reset_erp_info(sdata);
 329         bss_change |= BSS_CHANGED_BSSID;
 330         bss_change |= BSS_CHANGED_BEACON;
 331         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 332         bss_change |= BSS_CHANGED_BASIC_RATES;
 333         bss_change |= BSS_CHANGED_HT;
 334         bss_change |= BSS_CHANGED_IBSS;
 335         bss_change |= BSS_CHANGED_SSID;
 336
 337         /*
 338          * In 5 GHz/802.11a, we can always use short slot time.
 339          * (IEEE 802.11-2012 18.3.8.7)
 340          *
 341          * In 2.4GHz, we must always use long slots in IBSS for compatibility
 342          * reasons.
 343          * (IEEE 802.11-2012 19.4.5)
 344          *
 345          * HT follows these specifications (IEEE 802.11-2012 20.3.18)
 346          */
 347         sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
 348         bss_change |= BSS_CHANGED_ERP_SLOT;
 349
 350         /* cf. IEEE 802.11 9.2.12 */
 351         if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
 352                 sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
 353         else
 354                 sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
 355
 356         ieee80211_set_wmm_default(sdata, true);
 357
 358         sdata->vif.bss_conf.ibss_joined = true;
 359         sdata->vif.bss_conf.ibss_creator = creator;
 360
 361         err = drv_join_ibss(local, sdata);
 362         if (err) {
 363                 sdata->vif.bss_conf.ibss_joined = false;
 364                 sdata->vif.bss_conf.ibss_creator = false;
 365                 sdata->vif.bss_conf.enable_beacon = false;
 366                 sdata->vif.bss_conf.ssid_len = 0;
 367                 RCU_INIT_POINTER(ifibss->presp, NULL);
 368                 kfree_rcu(presp, rcu_head);
 369                 mutex_lock(&local->mtx);
 370                 ieee80211_vif_release_channel(sdata);
 371                 mutex_unlock(&local->mtx);
 372                 sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
 373                            err);
 374                 return;
 375         }
 376
 377         ieee80211_bss_info_change_notify(sdata, bss_change);
 378
 379         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 380         mod_timer(&ifibss->timer,
 381                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 382
 383         scan_width = cfg80211_chandef_to_scan_width(&chandef);
 384         bss = cfg80211_inform_bss_width_frame(local->hw.wiphy, chan,
 385                                               scan_width, mgmt,
 386                                               presp->head_len, 0, GFP_KERNEL);
 387         cfg80211_put_bss(local->hw.wiphy, bss);
 388         netif_carrier_on(sdata->dev);
 389         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 390 }
 391
 392 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 393                                     struct ieee80211_bss *bss)
 394 {
 395         struct cfg80211_bss *cbss =
 396                 container_of((void *)bss, struct cfg80211_bss, priv);
 397         struct ieee80211_supported_band *sband;
 398         struct cfg80211_chan_def chandef;
 399         u32 basic_rates;
 400         int i, j;
 401         u16 beacon_int = cbss->beacon_interval;
 402         const struct cfg80211_bss_ies *ies;
 403         enum nl80211_channel_type chan_type;
 404         u64 tsf;
 405         u32 rate_flags;
 406         int shift;
 407
 408         sdata_assert_lock(sdata);
 409
 410         if (beacon_int < 10)
 411                 beacon_int = 10;
 412
 413         switch (sdata->u.ibss.chandef.width) {
 414         case NL80211_CHAN_WIDTH_20_NOHT:
 415         case NL80211_CHAN_WIDTH_20:
 416         case NL80211_CHAN_WIDTH_40:
 417                 chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
 418                 cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
 419                 break;
 420         case NL80211_CHAN_WIDTH_5:
 421         case NL80211_CHAN_WIDTH_10:
 422                 cfg80211_chandef_create(&chandef, cbss->channel,
 423                                         NL80211_CHAN_WIDTH_20_NOHT);
 424                 chandef.width = sdata->u.ibss.chandef.width;
 425                 break;
 426         default:
 427                 /* fall back to 20 MHz for unsupported modes */
 428                 cfg80211_chandef_create(&chandef, cbss->channel,
 429                                         NL80211_CHAN_WIDTH_20_NOHT);
 430                 break;
 431         }
 432
 433         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 434         rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
 435         shift = ieee80211_vif_get_shift(&sdata->vif);
 436
 437         basic_rates = 0;
 438
 439         for (i = 0; i < bss->supp_rates_len; i++) {
 440                 int rate = bss->supp_rates[i] & 0x7f;
 441                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 442
 443                 for (j = 0; j < sband->n_bitrates; j++) {
 444                         int brate;
 445                         if ((rate_flags & sband->bitrates[j].flags)
 446                             != rate_flags)
 447                                 continue;
 448
 449                         brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
 450                                              5 * (1 << shift));
 451                         if (brate == rate) {
 452                                 if (is_basic)
 453                                         basic_rates |= BIT(j);
 454                                 break;
 455                         }
 456                 }
 457         }
 458
 459         rcu_read_lock();
 460         ies = rcu_dereference(cbss->ies);
 461         tsf = ies->tsf;
 462         rcu_read_unlock();
 463
 464         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 465                                   beacon_int,
 466                                   &chandef,
 467                                   basic_rates,
 468                                   cbss->capability,
 469                                   tsf, false);
 470 }
 471
 472 int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
 473                               struct cfg80211_csa_settings *csa_settings)
 474 {
 475         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 476         struct beacon_data *presp, *old_presp;
 477         struct cfg80211_bss *cbss;
 478         const struct cfg80211_bss_ies *ies;
 479         u16 capability;
 480         u64 tsf;
 481         int ret = 0;
 482
 483         sdata_assert_lock(sdata);
 484
 485         capability = WLAN_CAPABILITY_IBSS;
 486
 487         if (ifibss->privacy)
 488                 capability |= WLAN_CAPABILITY_PRIVACY;
 489
 490         cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
 491                                 ifibss->bssid, ifibss->ssid,
 492                                 ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 493                                 WLAN_CAPABILITY_PRIVACY,
 494                                 capability);
 495
 496         if (WARN_ON(!cbss)) {
 497                 ret = -EINVAL;
 498                 goto out;
 499         }
 500
 501         rcu_read_lock();
 502         ies = rcu_dereference(cbss->ies);
 503         tsf = ies->tsf;
 504         rcu_read_unlock();
 505         cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 506
 507         old_presp = rcu_dereference_protected(ifibss->presp,
 508                                           lockdep_is_held(&sdata->wdev.mtx));
 509
 510         presp = ieee80211_ibss_build_presp(sdata,
 511                                            sdata->vif.bss_conf.beacon_int,
 512                                            sdata->vif.bss_conf.basic_rates,
 513                                            capability, tsf, &ifibss->chandef,
 514                                            NULL, csa_settings);
 515         if (!presp) {
 516                 ret = -ENOMEM;
 517                 goto out;
 518         }
 519
 520         rcu_assign_pointer(ifibss->presp, presp);
 521         if (old_presp)
 522                 kfree_rcu(old_presp, rcu_head);
 523
 524         /* it might not send the beacon for a while. send an action frame
 525          * immediately to announce the channel switch.
 526          */
 527         if (csa_settings)
 528                 ieee80211_send_action_csa(sdata, csa_settings);
 529
 530         return BSS_CHANGED_BEACON;
 531  out:
 532         return ret;
 533 }
 534
 535 int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
 536 {
 537         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 538         struct cfg80211_bss *cbss;
 539         int err;
 540         u16 capability;
 541
 542         sdata_assert_lock(sdata);
 543
 544         /* update cfg80211 bss information with the new channel */
 545         if (!is_zero_ether_addr(ifibss->bssid)) {
 546                 capability = WLAN_CAPABILITY_IBSS;
 547
 548                 if (ifibss->privacy)
 549                         capability |= WLAN_CAPABILITY_PRIVACY;
 550
 551                 cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
 552                                         ifibss->chandef.chan,
 553                                         ifibss->bssid, ifibss->ssid,
 554                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 555                                         WLAN_CAPABILITY_PRIVACY,
 556                                         capability);
 557                 /* XXX: should not really modify cfg80211 data */
 558                 if (cbss) {
 559                         cbss->channel = sdata->csa_chandef.chan;
 560                         cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 561                 }
 562         }
 563
 564         ifibss->chandef = sdata->csa_chandef;
 565
 566         /* generate the beacon */
 567         err = ieee80211_ibss_csa_beacon(sdata, NULL);
 568         if (err < 0)
 569                 return err;
 570
 571         if (err)
 572                 ieee80211_bss_info_change_notify(sdata, err);
 573
 574         return 0;
 575 }
 576
 577 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
 578 {
 579         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 580
 581         cancel_work_sync(&ifibss->csa_connection_drop_work);
 582 }
 583
 584 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
 585         __acquires(RCU)
 586 {
 587         struct ieee80211_sub_if_data *sdata = sta->sdata;
 588         u8 addr[ETH_ALEN];
 589
 590         memcpy(addr, sta->sta.addr, ETH_ALEN);
 591
 592         ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
 593
 594         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 595         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 596         /* authorize the station only if the network is not RSN protected. If
 597          * not wait for the userspace to authorize it */
 598         if (!sta->sdata->u.ibss.control_port)
 599                 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 600
 601         rate_control_rate_init(sta);
 602
 603         /* If it fails, maybe we raced another insertion? */
 604         if (sta_info_insert_rcu(sta))
 605                 return sta_info_get(sdata, addr);
 606         return sta;
 607 }
 608
 609 static struct sta_info *
 610 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
 611                        const u8 *addr, u32 supp_rates)
 612         __acquires(RCU)
 613 {
 614         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 615         struct ieee80211_local *local = sdata->local;
 616         struct sta_info *sta;
 617         struct ieee80211_chanctx_conf *chanctx_conf;
 618         struct ieee80211_supported_band *sband;
 619         enum nl80211_bss_scan_width scan_width;
 620         int band;
 621
 622         /*
 623          * XXX: Consider removing the least recently used entry and
 624          *      allow new one to be added.
 625          */
 626         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 627                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
 628                                     sdata->name, addr);
 629                 rcu_read_lock();
 630                 return NULL;
 631         }
 632
 633         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
 634                 rcu_read_lock();
 635                 return NULL;
 636         }
 637
 638         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
 639                 rcu_read_lock();
 640                 return NULL;
 641         }
 642
 643         rcu_read_lock();
 644         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 645         if (WARN_ON_ONCE(!chanctx_conf))
 646                 return NULL;
 647         band = chanctx_conf->def.chan->band;
 648         scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
 649         rcu_read_unlock();
 650
 651         sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 652         if (!sta) {
 653                 rcu_read_lock();
 654                 return NULL;
 655         }
 656
 657         sta->last_rx = jiffies;
 658
 659         /* make sure mandatory rates are always added */
 660         sband = local->hw.wiphy->bands[band];
 661         sta->sta.supp_rates[band] = supp_rates |
 662                         ieee80211_mandatory_rates(sband, scan_width);
 663
 664         return ieee80211_ibss_finish_sta(sta);
 665 }
 666
 667 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 668 {
 669         struct ieee80211_local *local = sdata->local;
 670         int active = 0;
 671         struct sta_info *sta;
 672
 673         sdata_assert_lock(sdata);
 674
 675         rcu_read_lock();
 676
 677         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 678                 if (sta->sdata == sdata &&
 679                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 680                                jiffies)) {
 681                         active++;
 682                         break;
 683                 }
 684         }
 685
 686         rcu_read_unlock();
 687
 688         return active;
 689 }
 690
 691 static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
 692 {
 693         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 694         struct ieee80211_local *local = sdata->local;
 695         struct cfg80211_bss *cbss;
 696         struct beacon_data *presp;
 697         struct sta_info *sta;
 698         u16 capability;
 699
 700         if (!is_zero_ether_addr(ifibss->bssid)) {
 701                 capability = WLAN_CAPABILITY_IBSS;
 702
 703                 if (ifibss->privacy)
 704                         capability |= WLAN_CAPABILITY_PRIVACY;
 705
 706                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
 707                                         ifibss->bssid, ifibss->ssid,
 708                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 709                                         WLAN_CAPABILITY_PRIVACY,
 710                                         capability);
 711
 712                 if (cbss) {
 713                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
 714                         cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
 715                 }
 716         }
 717
 718         ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 719
 720         sta_info_flush(sdata);
 721
 722         spin_lock_bh(&ifibss->incomplete_lock);
 723         while (!list_empty(&ifibss->incomplete_stations)) {
 724                 sta = list_first_entry(&ifibss->incomplete_stations,
 725                                        struct sta_info, list);
 726                 list_del(&sta->list);
 727                 spin_unlock_bh(&ifibss->incomplete_lock);
 728
 729                 sta_info_free(local, sta);
 730                 spin_lock_bh(&ifibss->incomplete_lock);
 731         }
 732         spin_unlock_bh(&ifibss->incomplete_lock);
 733
 734         netif_carrier_off(sdata->dev);
 735
 736         sdata->vif.bss_conf.ibss_joined = false;
 737         sdata->vif.bss_conf.ibss_creator = false;
 738         sdata->vif.bss_conf.enable_beacon = false;
 739         sdata->vif.bss_conf.ssid_len = 0;
 740
 741         /* remove beacon */
 742         presp = rcu_dereference_protected(ifibss->presp,
 743                                           lockdep_is_held(&sdata->wdev.mtx));
 744         RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
 745         if (presp)
 746                 kfree_rcu(presp, rcu_head);
 747
 748         clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
 749         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 750                                                 BSS_CHANGED_IBSS);
 751         drv_leave_ibss(local, sdata);
 752         mutex_lock(&local->mtx);
 753         ieee80211_vif_release_channel(sdata);
 754         mutex_unlock(&local->mtx);
 755 }
 756
 757 static void ieee80211_csa_connection_drop_work(struct work_struct *work)
 758 {
 759         struct ieee80211_sub_if_data *sdata =
 760                 container_of(work, struct ieee80211_sub_if_data,
 761                              u.ibss.csa_connection_drop_work);
 762
 763         sdata_lock(sdata);
 764
 765         ieee80211_ibss_disconnect(sdata);
 766         synchronize_rcu();
 767         skb_queue_purge(&sdata->skb_queue);
 768
 769         /* trigger a scan to find another IBSS network to join */
 770         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 771
 772         sdata_unlock(sdata);
 773 }
 774
 775 static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
 776 {
 777         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 778         int err;
 779
 780         /* if the current channel is a DFS channel, mark the channel as
 781          * unavailable.
 782          */
 783         err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 784                                             &ifibss->chandef);
 785         if (err > 0)
 786                 cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
 787                                      GFP_ATOMIC);
 788 }
 789
 790 static bool
 791 ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 792                                   struct ieee802_11_elems *elems,
 793                                   bool beacon)
 794 {
 795         struct cfg80211_csa_settings params;
 796         struct ieee80211_csa_ie csa_ie;
 797         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 798         enum nl80211_channel_type ch_type;
 799         int err;
 800         u32 sta_flags;
 801
 802         sta_flags = IEEE80211_STA_DISABLE_VHT;
 803         switch (ifibss->chandef.width) {
 804         case NL80211_CHAN_WIDTH_5:
 805         case NL80211_CHAN_WIDTH_10:
 806         case NL80211_CHAN_WIDTH_20_NOHT:
 807                 sta_flags |= IEEE80211_STA_DISABLE_HT;
 808                 /* fall through */
 809         case NL80211_CHAN_WIDTH_20:
 810                 sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
 811                 break;
 812         default:
 813                 break;
 814         }
 815
 816         memset(&params, 0, sizeof(params));
 817         memset(&csa_ie, 0, sizeof(csa_ie));
 818         err = ieee80211_parse_ch_switch_ie(sdata, elems, beacon,
 819                                            ifibss->chandef.chan->band,
 820                                            sta_flags, ifibss->bssid, &csa_ie);
 821         /* can't switch to destination channel, fail */
 822         if (err < 0)
 823                 goto disconnect;
 824
 825         /* did not contain a CSA */
 826         if (err)
 827                 return false;
 828
 829         /* channel switch is not supported, disconnect */
 830         if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
 831                 goto disconnect;
 832
 833         params.count = csa_ie.count;
 834         params.chandef = csa_ie.chandef;
 835
 836         switch (ifibss->chandef.width) {
 837         case NL80211_CHAN_WIDTH_20_NOHT:
 838         case NL80211_CHAN_WIDTH_20:
 839         case NL80211_CHAN_WIDTH_40:
 840                 /* keep our current HT mode (HT20/HT40+/HT40-), even if
 841                  * another mode  has been announced. The mode is not adopted
 842                  * within the beacon while doing CSA and we should therefore
 843                  * keep the mode which we announce.
 844                  */
 845                 ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
 846                 cfg80211_chandef_create(&params.chandef, params.chandef.chan,
 847                                         ch_type);
 848                 break;
 849         case NL80211_CHAN_WIDTH_5:
 850         case NL80211_CHAN_WIDTH_10:
 851                 if (params.chandef.width != ifibss->chandef.width) {
 852                         sdata_info(sdata,
 853                                    "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
 854                                    ifibss->bssid,
 855                                    params.chandef.chan->center_freq,
 856                                    params.chandef.width,
 857                                    params.chandef.center_freq1,
 858                                    params.chandef.center_freq2);
 859                         goto disconnect;
 860                 }
 861                 break;
 862         default:
 863                 /* should not happen, sta_flags should prevent VHT modes. */
 864                 WARN_ON(1);
 865                 goto disconnect;
 866         }
 867
 868         if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef)) {
 869                 sdata_info(sdata,
 870                            "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
 871                            ifibss->bssid,
 872                            params.chandef.chan->center_freq,
 873                            params.chandef.width,
 874                            params.chandef.center_freq1,
 875                            params.chandef.center_freq2);
 876                 goto disconnect;
 877         }
 878
 879         err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
 880                                             &params.chandef);
 881         if (err < 0)
 882                 goto disconnect;
 883         if (err) {
 884                 /* IBSS-DFS only allowed with a control program */
 885                 if (!ifibss->userspace_handles_dfs)
 886                         goto disconnect;
 887
 888                 params.radar_required = true;
 889         }
 890
 891         if (cfg80211_chandef_identical(&params.chandef,
 892                                        &sdata->vif.bss_conf.chandef)) {
 893                 ibss_dbg(sdata,
 894                          "received csa with an identical chandef, ignoring\n");
 895                 return true;
 896         }
 897
 898         /* all checks done, now perform the channel switch. */
 899         ibss_dbg(sdata,
 900                  "received channel switch announcement to go to channel %d MHz\n",
 901                  params.chandef.chan->center_freq);
 902
 903         params.block_tx = !!csa_ie.mode;
 904
 905         if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
 906                                      &params))
 907                 goto disconnect;
 908
 909         ieee80211_ibss_csa_mark_radar(sdata);
 910
 911         return true;
 912 disconnect:
 913         ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
 914         ieee80211_queue_work(&sdata->local->hw,
 915                              &ifibss->csa_connection_drop_work);
 916
 917         ieee80211_ibss_csa_mark_radar(sdata);
 918
 919         return true;
 920 }
 921
 922 static void
 923 ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
 924                                 struct ieee80211_mgmt *mgmt, size_t len,
 925                                 struct ieee80211_rx_status *rx_status,
 926                                 struct ieee802_11_elems *elems)
 927 {
 928         int required_len;
 929
 930         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
 931                 return;
 932
 933         /* CSA is the only action we handle for now */
 934         if (mgmt->u.action.u.measurement.action_code !=
 935             WLAN_ACTION_SPCT_CHL_SWITCH)
 936                 return;
 937
 938         required_len = IEEE80211_MIN_ACTION_SIZE +
 939                        sizeof(mgmt->u.action.u.chan_switch);
 940         if (len < required_len)
 941                 return;
 942
 943         if (!sdata->vif.csa_active)
 944                 ieee80211_ibss_process_chanswitch(sdata, elems, false);
 945 }
 946
 947 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
 948                                           struct ieee80211_mgmt *mgmt,
 949                                           size_t len)
 950 {
 951         u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
 952
 953         if (len < IEEE80211_DEAUTH_FRAME_LEN)
 954                 return;
 955
 956         ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
 957                  mgmt->sa, mgmt->da, mgmt->bssid, reason);
 958         sta_info_destroy_addr(sdata, mgmt->sa);
 959 }
 960
 961 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
 962                                         struct ieee80211_mgmt *mgmt,
 963                                         size_t len)
 964 {
 965         u16 auth_alg, auth_transaction;
 966
 967         sdata_assert_lock(sdata);
 968
 969         if (len < 24 + 6)
 970                 return;
 971
 972         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
 973         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
 974
 975         ibss_dbg(sdata,
 976                  "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
 977                  mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
 978
 979         if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
 980                 return;
 981
 982         /*
 983          * IEEE 802.11 standard does not require authentication in IBSS
 984          * networks and most implementations do not seem to use it.
 985          * However, try to reply to authentication attempts if someone
 986          * has actually implemented this.
 987          */
 988         ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
 989                             mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
 990 }
 991
 992 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 993                                   struct ieee80211_mgmt *mgmt, size_t len,
 994                                   struct ieee80211_rx_status *rx_status,
 995                                   struct ieee802_11_elems *elems)
 996 {
 997         struct ieee80211_local *local = sdata->local;
 998         int freq;
 999         struct cfg80211_bss *cbss;
1000         struct ieee80211_bss *bss;
1001         struct sta_info *sta;
1002         struct ieee80211_channel *channel;
1003         u64 beacon_timestamp, rx_timestamp;
1004         u32 supp_rates = 0;
1005         enum ieee80211_band band = rx_status->band;
1006         enum nl80211_bss_scan_width scan_width;
1007         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
1008         bool rates_updated = false;
1009
1010         if (elems->ds_params)
1011                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
1012                                                       band);
1013         else
1014                 freq = rx_status->freq;
1015
1016         channel = ieee80211_get_channel(local->hw.wiphy, freq);
1017
1018         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1019                 return;
1020
1021         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
1022             ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
1023
1024                 rcu_read_lock();
1025                 sta = sta_info_get(sdata, mgmt->sa);
1026
1027                 if (elems->supp_rates) {
1028                         supp_rates = ieee80211_sta_get_rates(sdata, elems,
1029                                                              band, NULL);
1030                         if (sta) {
1031                                 u32 prev_rates;
1032
1033                                 prev_rates = sta->sta.supp_rates[band];
1034                                 /* make sure mandatory rates are always added */
1035                                 scan_width = NL80211_BSS_CHAN_WIDTH_20;
1036                                 if (rx_status->flag & RX_FLAG_5MHZ)
1037                                         scan_width = NL80211_BSS_CHAN_WIDTH_5;
1038                                 if (rx_status->flag & RX_FLAG_10MHZ)
1039                                         scan_width = NL80211_BSS_CHAN_WIDTH_10;
1040
1041                                 sta->sta.supp_rates[band] = supp_rates |
1042                                         ieee80211_mandatory_rates(sband,
1043                                                                   scan_width);
1044                                 if (sta->sta.supp_rates[band] != prev_rates) {
1045                                         ibss_dbg(sdata,
1046                                                  "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1047                                                  sta->sta.addr, prev_rates,
1048                                                  sta->sta.supp_rates[band]);
1049                                         rates_updated = true;
1050                                 }
1051                         } else {
1052                                 rcu_read_unlock();
1053                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1054                                                 mgmt->sa, supp_rates);
1055                         }
1056                 }
1057
1058                 if (sta && elems->wmm_info)
1059                         set_sta_flag(sta, WLAN_STA_WME);
1060
1061                 if (sta && elems->ht_operation && elems->ht_cap_elem &&
1062                     sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1063                     sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1064                     sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1065                         /* we both use HT */
1066                         struct ieee80211_ht_cap htcap_ie;
1067                         struct cfg80211_chan_def chandef;
1068
1069                         ieee80211_ht_oper_to_chandef(channel,
1070                                                      elems->ht_operation,
1071                                                      &chandef);
1072
1073                         memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1074
1075                         /*
1076                          * fall back to HT20 if we don't use or use
1077                          * the other extension channel
1078                          */
1079                         if (chandef.center_freq1 !=
1080                             sdata->u.ibss.chandef.center_freq1)
1081                                 htcap_ie.cap_info &=
1082                                         cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
1083
1084                         rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
1085                                                 sdata, sband, &htcap_ie, sta);
1086                 }
1087
1088                 if (sta && rates_updated) {
1089                         drv_sta_rc_update(local, sdata, &sta->sta,
1090                                           IEEE80211_RC_SUPP_RATES_CHANGED);
1091                         rate_control_rate_init(sta);
1092                 }
1093
1094                 rcu_read_unlock();
1095         }
1096
1097         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
1098                                         channel);
1099         if (!bss)
1100                 return;
1101
1102         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1103
1104         /* same for beacon and probe response */
1105         beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1106
1107         /* check if we need to merge IBSS */
1108
1109         /* not an IBSS */
1110         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1111                 goto put_bss;
1112
1113         /* different channel */
1114         if (sdata->u.ibss.fixed_channel &&
1115             sdata->u.ibss.chandef.chan != cbss->channel)
1116                 goto put_bss;
1117
1118         /* different SSID */
1119         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1120             memcmp(elems->ssid, sdata->u.ibss.ssid,
1121                                 sdata->u.ibss.ssid_len))
1122                 goto put_bss;
1123
1124         /* process channel switch */
1125         if (sdata->vif.csa_active ||
1126             ieee80211_ibss_process_chanswitch(sdata, elems, true))
1127                 goto put_bss;
1128
1129         /* same BSSID */
1130         if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1131                 goto put_bss;
1132
1133         /* we use a fixed BSSID */
1134         if (sdata->u.ibss.fixed_bssid)
1135                 goto put_bss;
1136
1137         if (ieee80211_have_rx_timestamp(rx_status)) {
1138                 /* time when timestamp field was received */
1139                 rx_timestamp =
1140                         ieee80211_calculate_rx_timestamp(local, rx_status,
1141                                                          len + FCS_LEN, 24);
1142         } else {
1143                 /*
1144                  * second best option: get current TSF
1145                  * (will return -1 if not supported)
1146                  */
1147                 rx_timestamp = drv_get_tsf(local, sdata);
1148         }
1149
1150         ibss_dbg(sdata,
1151                  "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
1152                  mgmt->sa, mgmt->bssid,
1153                  (unsigned long long)rx_timestamp,
1154                  (unsigned long long)beacon_timestamp,
1155                  (unsigned long long)(rx_timestamp - beacon_timestamp),
1156                  jiffies);
1157
1158         if (beacon_timestamp > rx_timestamp) {
1159                 ibss_dbg(sdata,
1160                          "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1161                          mgmt->bssid);
1162                 ieee80211_sta_join_ibss(sdata, bss);
1163                 supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1164                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1165                                        supp_rates);
1166                 rcu_read_unlock();
1167         }
1168
1169  put_bss:
1170         ieee80211_rx_bss_put(local, bss);
1171 }
1172
1173 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1174                               const u8 *bssid, const u8 *addr,
1175                               u32 supp_rates)
1176 {
1177         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1178         struct ieee80211_local *local = sdata->local;
1179         struct sta_info *sta;
1180         struct ieee80211_chanctx_conf *chanctx_conf;
1181         struct ieee80211_supported_band *sband;
1182         enum nl80211_bss_scan_width scan_width;
1183         int band;
1184
1185         /*
1186          * XXX: Consider removing the least recently used entry and
1187          *      allow new one to be added.
1188          */
1189         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1190                 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1191                                     sdata->name, addr);
1192                 return;
1193         }
1194
1195         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1196                 return;
1197
1198         if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1199                 return;
1200
1201         rcu_read_lock();
1202         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1203         if (WARN_ON_ONCE(!chanctx_conf)) {
1204                 rcu_read_unlock();
1205                 return;
1206         }
1207         band = chanctx_conf->def.chan->band;
1208         scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1209         rcu_read_unlock();
1210
1211         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1212         if (!sta)
1213                 return;
1214
1215         sta->last_rx = jiffies;
1216
1217         /* make sure mandatory rates are always added */
1218         sband = local->hw.wiphy->bands[band];
1219         sta->sta.supp_rates[band] = supp_rates |
1220                         ieee80211_mandatory_rates(sband, scan_width);
1221
1222         spin_lock(&ifibss->incomplete_lock);
1223         list_add(&sta->list, &ifibss->incomplete_stations);
1224         spin_unlock(&ifibss->incomplete_lock);
1225         ieee80211_queue_work(&local->hw, &sdata->work);
1226 }
1227
1228 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1229 {
1230         struct ieee80211_local *local = sdata->local;
1231         struct sta_info *sta, *tmp;
1232         unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1233         unsigned long exp_rsn_time = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1234
1235         mutex_lock(&local->sta_mtx);
1236
1237         list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1238                 if (sdata != sta->sdata)
1239                         continue;
1240
1241                 if (time_after(jiffies, sta->last_rx + exp_time) ||
1242                     (time_after(jiffies, sta->last_rx + exp_rsn_time) &&
1243                      sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1244                         sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1245                                 sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1246                                 "not authorized " : "", sta->sta.addr);
1247
1248                         WARN_ON(__sta_info_destroy(sta));
1249                 }
1250         }
1251
1252         mutex_unlock(&local->sta_mtx);
1253 }
1254
1255 /*
1256  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1257  */
1258
1259 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1260 {
1261         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1262         enum nl80211_bss_scan_width scan_width;
1263
1264         sdata_assert_lock(sdata);
1265
1266         mod_timer(&ifibss->timer,
1267                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1268
1269         ieee80211_ibss_sta_expire(sdata);
1270
1271         if (time_before(jiffies, ifibss->last_scan_completed +
1272                        IEEE80211_IBSS_MERGE_INTERVAL))
1273                 return;
1274
1275         if (ieee80211_sta_active_ibss(sdata))
1276                 return;
1277
1278         if (ifibss->fixed_channel)
1279                 return;
1280
1281         sdata_info(sdata,
1282                    "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1283
1284         scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1285         ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1286                                     NULL, scan_width);
1287 }
1288
1289 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1290 {
1291         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1292         u8 bssid[ETH_ALEN];
1293         u16 capability;
1294         int i;
1295
1296         sdata_assert_lock(sdata);
1297
1298         if (ifibss->fixed_bssid) {
1299                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
1300         } else {
1301                 /* Generate random, not broadcast, locally administered BSSID. Mix in
1302                  * own MAC address to make sure that devices that do not have proper
1303                  * random number generator get different BSSID. */
1304                 get_random_bytes(bssid, ETH_ALEN);
1305                 for (i = 0; i < ETH_ALEN; i++)
1306                         bssid[i] ^= sdata->vif.addr[i];
1307                 bssid[0] &= ~0x01;
1308                 bssid[0] |= 0x02;
1309         }
1310
1311         sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1312
1313         capability = WLAN_CAPABILITY_IBSS;
1314
1315         if (ifibss->privacy)
1316                 capability |= WLAN_CAPABILITY_PRIVACY;
1317         else
1318                 sdata->drop_unencrypted = 0;
1319
1320         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1321                                   &ifibss->chandef, ifibss->basic_rates,
1322                                   capability, 0, true);
1323 }
1324
1325 /*
1326  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1327  */
1328
1329 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1330 {
1331         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1332         struct ieee80211_local *local = sdata->local;
1333         struct cfg80211_bss *cbss;
1334         struct ieee80211_channel *chan = NULL;
1335         const u8 *bssid = NULL;
1336         enum nl80211_bss_scan_width scan_width;
1337         int active_ibss;
1338         u16 capability;
1339
1340         sdata_assert_lock(sdata);
1341
1342         active_ibss = ieee80211_sta_active_ibss(sdata);
1343         ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1344
1345         if (active_ibss)
1346                 return;
1347
1348         capability = WLAN_CAPABILITY_IBSS;
1349         if (ifibss->privacy)
1350                 capability |= WLAN_CAPABILITY_PRIVACY;
1351         if (ifibss->fixed_bssid)
1352                 bssid = ifibss->bssid;
1353         if (ifibss->fixed_channel)
1354                 chan = ifibss->chandef.chan;
1355         if (!is_zero_ether_addr(ifibss->bssid))
1356                 bssid = ifibss->bssid;
1357         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1358                                 ifibss->ssid, ifibss->ssid_len,
1359                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
1360                                 capability);
1361
1362         if (cbss) {
1363                 struct ieee80211_bss *bss;
1364
1365                 bss = (void *)cbss->priv;
1366                 ibss_dbg(sdata,
1367                          "sta_find_ibss: selected %pM current %pM\n",
1368                          cbss->bssid, ifibss->bssid);
1369                 sdata_info(sdata,
1370                            "Selected IBSS BSSID %pM based on configured SSID\n",
1371                            cbss->bssid);
1372
1373                 ieee80211_sta_join_ibss(sdata, bss);
1374                 ieee80211_rx_bss_put(local, bss);
1375                 return;
1376         }
1377
1378         /* if a fixed bssid and a fixed freq have been provided create the IBSS
1379          * directly and do not waste time scanning
1380          */
1381         if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1382                 sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1383                            bssid);
1384                 ieee80211_sta_create_ibss(sdata);
1385                 return;
1386         }
1387
1388
1389         ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1390
1391         /* Selected IBSS not found in current scan results - try to scan */
1392         if (time_after(jiffies, ifibss->last_scan_completed +
1393                                         IEEE80211_SCAN_INTERVAL)) {
1394                 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1395
1396                 scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1397                 ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1398                                             ifibss->ssid_len, chan,
1399                                             scan_width);
1400         } else {
1401                 int interval = IEEE80211_SCAN_INTERVAL;
1402
1403                 if (time_after(jiffies, ifibss->ibss_join_req +
1404                                IEEE80211_IBSS_JOIN_TIMEOUT))
1405                         ieee80211_sta_create_ibss(sdata);
1406
1407                 mod_timer(&ifibss->timer,
1408                           round_jiffies(jiffies + interval));
1409         }
1410 }
1411
1412 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1413                                         struct sk_buff *req)
1414 {
1415         struct ieee80211_mgmt *mgmt = (void *)req->data;
1416         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1417         struct ieee80211_local *local = sdata->local;
1418         int tx_last_beacon, len = req->len;
1419         struct sk_buff *skb;
1420         struct beacon_data *presp;
1421         u8 *pos, *end;
1422
1423         sdata_assert_lock(sdata);
1424
1425         presp = rcu_dereference_protected(ifibss->presp,
1426                                           lockdep_is_held(&sdata->wdev.mtx));
1427
1428         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1429             len < 24 + 2 || !presp)
1430                 return;
1431
1432         tx_last_beacon = drv_tx_last_beacon(local);
1433
1434         ibss_dbg(sdata,
1435                  "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
1436                  mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
1437
1438         if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1439                 return;
1440
1441         if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1442             !is_broadcast_ether_addr(mgmt->bssid))
1443                 return;
1444
1445         end = ((u8 *) mgmt) + len;
1446         pos = mgmt->u.probe_req.variable;
1447         if (pos[0] != WLAN_EID_SSID ||
1448             pos + 2 + pos[1] > end) {
1449                 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1450                          mgmt->sa);
1451                 return;
1452         }
1453         if (pos[1] != 0 &&
1454             (pos[1] != ifibss->ssid_len ||
1455              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1456                 /* Ignore ProbeReq for foreign SSID */
1457                 return;
1458         }
1459
1460         /* Reply with ProbeResp */
1461         skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1462         if (!skb)
1463                 return;
1464
1465         skb_reserve(skb, local->tx_headroom);
1466         memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
1467
1468         memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1469         ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1470         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1471         ieee80211_tx_skb(sdata, skb);
1472 }
1473
1474 static
1475 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1476                                     struct ieee80211_mgmt *mgmt, size_t len,
1477                                     struct ieee80211_rx_status *rx_status)
1478 {
1479         size_t baselen;
1480         struct ieee802_11_elems elems;
1481
1482         BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1483                      offsetof(typeof(mgmt->u.beacon), variable));
1484
1485         /*
1486          * either beacon or probe_resp but the variable field is at the
1487          * same offset
1488          */
1489         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1490         if (baselen > len)
1491                 return;
1492
1493         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1494                                false, &elems);
1495
1496         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
1497 }
1498
1499 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1500                                    struct sk_buff *skb)
1501 {
1502         struct ieee80211_rx_status *rx_status;
1503         struct ieee80211_mgmt *mgmt;
1504         u16 fc;
1505         struct ieee802_11_elems elems;
1506         int ies_len;
1507
1508         rx_status = IEEE80211_SKB_RXCB(skb);
1509         mgmt = (struct ieee80211_mgmt *) skb->data;
1510         fc = le16_to_cpu(mgmt->frame_control);
1511
1512         sdata_lock(sdata);
1513
1514         if (!sdata->u.ibss.ssid_len)
1515                 goto mgmt_out; /* not ready to merge yet */
1516
1517         switch (fc & IEEE80211_FCTL_STYPE) {
1518         case IEEE80211_STYPE_PROBE_REQ:
1519                 ieee80211_rx_mgmt_probe_req(sdata, skb);
1520                 break;
1521         case IEEE80211_STYPE_PROBE_RESP:
1522         case IEEE80211_STYPE_BEACON:
1523                 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1524                                                rx_status);
1525                 break;
1526         case IEEE80211_STYPE_AUTH:
1527                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1528                 break;
1529         case IEEE80211_STYPE_DEAUTH:
1530                 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1531                 break;
1532         case IEEE80211_STYPE_ACTION:
1533                 switch (mgmt->u.action.category) {
1534                 case WLAN_CATEGORY_SPECTRUM_MGMT:
1535                         ies_len = skb->len -
1536                                   offsetof(struct ieee80211_mgmt,
1537                                            u.action.u.chan_switch.variable);
1538
1539                         if (ies_len < 0)
1540                                 break;
1541
1542                         ieee802_11_parse_elems(
1543                                 mgmt->u.action.u.chan_switch.variable,
1544                                 ies_len, true, &elems);
1545
1546                         if (elems.parse_error)
1547                                 break;
1548
1549                         ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
1550                                                         rx_status, &elems);
1551                         break;
1552                 }
1553         }
1554
1555  mgmt_out:
1556         sdata_unlock(sdata);
1557 }
1558
1559 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1560 {
1561         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1562         struct sta_info *sta;
1563
1564         sdata_lock(sdata);
1565
1566         /*
1567          * Work could be scheduled after scan or similar
1568          * when we aren't even joined (or trying) with a
1569          * network.
1570          */
1571         if (!ifibss->ssid_len)
1572                 goto out;
1573
1574         spin_lock_bh(&ifibss->incomplete_lock);
1575         while (!list_empty(&ifibss->incomplete_stations)) {
1576                 sta = list_first_entry(&ifibss->incomplete_stations,
1577                                        struct sta_info, list);
1578                 list_del(&sta->list);
1579                 spin_unlock_bh(&ifibss->incomplete_lock);
1580
1581                 ieee80211_ibss_finish_sta(sta);
1582                 rcu_read_unlock();
1583                 spin_lock_bh(&ifibss->incomplete_lock);
1584         }
1585         spin_unlock_bh(&ifibss->incomplete_lock);
1586
1587         switch (ifibss->state) {
1588         case IEEE80211_IBSS_MLME_SEARCH:
1589                 ieee80211_sta_find_ibss(sdata);
1590                 break;
1591         case IEEE80211_IBSS_MLME_JOINED:
1592                 ieee80211_sta_merge_ibss(sdata);
1593                 break;
1594         default:
1595                 WARN_ON(1);
1596                 break;
1597         }
1598
1599  out:
1600         sdata_unlock(sdata);
1601 }
1602
1603 static void ieee80211_ibss_timer(unsigned long data)
1604 {
1605         struct ieee80211_sub_if_data *sdata =
1606                 (struct ieee80211_sub_if_data *) data;
1607
1608         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1609 }
1610
1611 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1612 {
1613         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1614
1615         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1616                     (unsigned long) sdata);
1617         INIT_LIST_HEAD(&ifibss->incomplete_stations);
1618         spin_lock_init(&ifibss->incomplete_lock);
1619         INIT_WORK(&ifibss->csa_connection_drop_work,
1620                   ieee80211_csa_connection_drop_work);
1621 }
1622
1623 /* scan finished notification */
1624 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1625 {
1626         struct ieee80211_sub_if_data *sdata;
1627
1628         mutex_lock(&local->iflist_mtx);
1629         list_for_each_entry(sdata, &local->interfaces, list) {
1630                 if (!ieee80211_sdata_running(sdata))
1631                         continue;
1632                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1633                         continue;
1634                 sdata->u.ibss.last_scan_completed = jiffies;
1635                 ieee80211_queue_work(&local->hw, &sdata->work);
1636         }
1637         mutex_unlock(&local->iflist_mtx);
1638 }
1639
1640 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1641                         struct cfg80211_ibss_params *params)
1642 {
1643         u32 changed = 0;
1644         u32 rate_flags;
1645         struct ieee80211_supported_band *sband;
1646         int i;
1647
1648         if (params->bssid) {
1649                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1650                 sdata->u.ibss.fixed_bssid = true;
1651         } else
1652                 sdata->u.ibss.fixed_bssid = false;
1653
1654         sdata->u.ibss.privacy = params->privacy;
1655         sdata->u.ibss.control_port = params->control_port;
1656         sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1657         sdata->u.ibss.basic_rates = params->basic_rates;
1658
1659         /* fix basic_rates if channel does not support these rates */
1660         rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1661         sband = sdata->local->hw.wiphy->bands[params->chandef.chan->band];
1662         for (i = 0; i < sband->n_bitrates; i++) {
1663                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1664                         sdata->u.ibss.basic_rates &= ~BIT(i);
1665         }
1666         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1667                sizeof(params->mcast_rate));
1668
1669         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1670
1671         sdata->u.ibss.chandef = params->chandef;
1672         sdata->u.ibss.fixed_channel = params->channel_fixed;
1673
1674         if (params->ie) {
1675                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1676                                            GFP_KERNEL);
1677                 if (sdata->u.ibss.ie)
1678                         sdata->u.ibss.ie_len = params->ie_len;
1679         }
1680
1681         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1682         sdata->u.ibss.ibss_join_req = jiffies;
1683
1684         memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1685         sdata->u.ibss.ssid_len = params->ssid_len;
1686
1687         memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1688                sizeof(sdata->u.ibss.ht_capa));
1689         memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1690                sizeof(sdata->u.ibss.ht_capa_mask));
1691
1692         /*
1693          * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1694          * reserved, but an HT STA shall protect HT transmissions as though
1695          * the HT Protection field were set to non-HT mixed mode.
1696          *
1697          * In an IBSS, the RIFS Mode field of the HT Operation element is
1698          * also reserved, but an HT STA shall operate as though this field
1699          * were set to 1.
1700          */
1701
1702         sdata->vif.bss_conf.ht_operation_mode |=
1703                   IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1704                 | IEEE80211_HT_PARAM_RIFS_MODE;
1705
1706         changed |= BSS_CHANGED_HT;
1707         ieee80211_bss_info_change_notify(sdata, changed);
1708
1709         sdata->smps_mode = IEEE80211_SMPS_OFF;
1710         sdata->needed_rx_chains = sdata->local->rx_chains;
1711
1712         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1713
1714         return 0;
1715 }
1716
1717 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1718 {
1719         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1720
1721         ieee80211_ibss_disconnect(sdata);
1722         ifibss->ssid_len = 0;
1723         memset(ifibss->bssid, 0, ETH_ALEN);
1724
1725         /* remove beacon */
1726         kfree(sdata->u.ibss.ie);
1727
1728         /* on the next join, re-program HT parameters */
1729         memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1730         memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1731
1732         synchronize_rcu();
1733
1734         skb_queue_purge(&sdata->skb_queue);
1735
1736         del_timer_sync(&sdata->u.ibss.timer);
1737
1738         return 0;
1739 }