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/if_ether.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/mac80211.h>
  22 #include <asm/unaligned.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "rate.h"
  26
  27 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  28 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  30
  31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  32 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  33 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  34
  35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  36
  37
  38 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  39                                         struct ieee80211_mgmt *mgmt,
  40                                         size_t len)
  41 {
  42         u16 auth_alg, auth_transaction, status_code;
  43
  44         if (len < 24 + 6)
  45                 return;
  46
  47         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  48         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  49         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  50
  51         /*
  52          * IEEE 802.11 standard does not require authentication in IBSS
  53          * networks and most implementations do not seem to use it.
  54          * However, try to reply to authentication attempts if someone
  55          * has actually implemented this.
  56          */
  57         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  58                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  59                                     sdata->u.ibss.bssid, 0);
  60 }
  61
  62 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  63                                       const u8 *bssid, const int beacon_int,
  64                                       struct ieee80211_channel *chan,
  65                                       const size_t supp_rates_len,
  66                                       const u8 *supp_rates,
  67                                       const u16 capability, u64 tsf)
  68 {
  69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  70         struct ieee80211_local *local = sdata->local;
  71         int rates, i, j;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76
  77         if (local->ops->reset_tsf) {
  78                 /* Reset own TSF to allow time synchronization work. */
  79                 local->ops->reset_tsf(local_to_hw(local));
  80         }
  81
  82         skb = ifibss->skb;
  83         rcu_assign_pointer(ifibss->presp, NULL);
  84         synchronize_rcu();
  85         skb->data = skb->head;
  86         skb->len = 0;
  87         skb_reset_tail_pointer(skb);
  88         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  89
  90         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  91                 sta_info_flush(sdata->local, sdata);
  92
  93         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  94
  95         local->hw.conf.beacon_int = beacon_int >= 10 ? beacon_int : 10;
  96
  97         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  98
  99         ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);
 100
 101         local->oper_channel = chan;
 102         local->oper_channel_type = NL80211_CHAN_NO_HT;
 103         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 104         sband = local->hw.wiphy->bands[chan->band];
 105
 106         /* Build IBSS probe response */
 107         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 108         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 109         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 110                                           IEEE80211_STYPE_PROBE_RESP);
 111         memset(mgmt->da, 0xff, ETH_ALEN);
 112         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 113         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 114         mgmt->u.beacon.beacon_int = cpu_to_le16(local->hw.conf.beacon_int);
 115         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 116         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 117
 118         pos = skb_put(skb, 2 + ifibss->ssid_len);
 119         *pos++ = WLAN_EID_SSID;
 120         *pos++ = ifibss->ssid_len;
 121         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 122
 123         rates = supp_rates_len;
 124         if (rates > 8)
 125                 rates = 8;
 126         pos = skb_put(skb, 2 + rates);
 127         *pos++ = WLAN_EID_SUPP_RATES;
 128         *pos++ = rates;
 129         memcpy(pos, supp_rates, rates);
 130
 131         if (sband->band == IEEE80211_BAND_2GHZ) {
 132                 pos = skb_put(skb, 2 + 1);
 133                 *pos++ = WLAN_EID_DS_PARAMS;
 134                 *pos++ = 1;
 135                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 136         }
 137
 138         pos = skb_put(skb, 2 + 2);
 139         *pos++ = WLAN_EID_IBSS_PARAMS;
 140         *pos++ = 2;
 141         /* FIX: set ATIM window based on scan results */
 142         *pos++ = 0;
 143         *pos++ = 0;
 144
 145         if (supp_rates_len > 8) {
 146                 rates = supp_rates_len - 8;
 147                 pos = skb_put(skb, 2 + rates);
 148                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 149                 *pos++ = rates;
 150                 memcpy(pos, &supp_rates[8], rates);
 151         }
 152
 153         if (ifibss->ie_len)
 154                 memcpy(skb_put(skb, ifibss->ie_len),
 155                        ifibss->ie, ifibss->ie_len);
 156
 157         rcu_assign_pointer(ifibss->presp, skb);
 158
 159         ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
 160                                    IEEE80211_IFCC_BEACON_ENABLED);
 161
 162         rates = 0;
 163         for (i = 0; i < supp_rates_len; i++) {
 164                 int bitrate = (supp_rates[i] & 0x7f) * 5;
 165                 for (j = 0; j < sband->n_bitrates; j++)
 166                         if (sband->bitrates[j].bitrate == bitrate)
 167                                 rates |= BIT(j);
 168         }
 169
 170         ieee80211_sta_def_wmm_params(sdata, supp_rates_len, supp_rates);
 171
 172         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 173         mod_timer(&ifibss->timer,
 174                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 175
 176         cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 177                                   mgmt, skb->len, 0, GFP_KERNEL);
 178         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 179 }
 180
 181 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 182                                     struct ieee80211_bss *bss)
 183 {
 184         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
 185                                   bss->cbss.beacon_interval,
 186                                   bss->cbss.channel,
 187                                   bss->supp_rates_len, bss->supp_rates,
 188                                   bss->cbss.capability,
 189                                   bss->cbss.tsf);
 190 }
 191
 192 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 193                                   struct ieee80211_mgmt *mgmt,
 194                                   size_t len,
 195                                   struct ieee80211_rx_status *rx_status,
 196                                   struct ieee802_11_elems *elems,
 197                                   bool beacon)
 198 {
 199         struct ieee80211_local *local = sdata->local;
 200         int freq;
 201         struct ieee80211_bss *bss;
 202         struct sta_info *sta;
 203         struct ieee80211_channel *channel;
 204         u64 beacon_timestamp, rx_timestamp;
 205         u32 supp_rates = 0;
 206         enum ieee80211_band band = rx_status->band;
 207
 208         if (elems->ds_params && elems->ds_params_len == 1)
 209                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 210         else
 211                 freq = rx_status->freq;
 212
 213         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 214
 215         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 216                 return;
 217
 218         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 219             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 220                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 221
 222                 rcu_read_lock();
 223
 224                 sta = sta_info_get(local, mgmt->sa);
 225                 if (sta) {
 226                         u32 prev_rates;
 227
 228                         prev_rates = sta->sta.supp_rates[band];
 229                         /* make sure mandatory rates are always added */
 230                         sta->sta.supp_rates[band] = supp_rates |
 231                                 ieee80211_mandatory_rates(local, band);
 232
 233 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 234                         if (sta->sta.supp_rates[band] != prev_rates)
 235                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 236                                     "for %pM based on beacon info (0x%llx | "
 237                                     "0x%llx -> 0x%llx)\n",
 238                                     sdata->dev->name,
 239                                     sta->sta.addr,
 240                                     (unsigned long long) prev_rates,
 241                                     (unsigned long long) supp_rates,
 242                                     (unsigned long long) sta->sta.supp_rates[band]);
 243 #endif
 244                 } else
 245                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 246
 247                 rcu_read_unlock();
 248         }
 249
 250         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 251                                         channel, beacon);
 252         if (!bss)
 253                 return;
 254
 255         /* was just updated in ieee80211_bss_info_update */
 256         beacon_timestamp = bss->cbss.tsf;
 257
 258         /* check if we need to merge IBSS */
 259
 260         /* merge only on beacons (???) */
 261         if (!beacon)
 262                 goto put_bss;
 263
 264         /* we use a fixed BSSID */
 265         if (sdata->u.ibss.bssid)
 266                 goto put_bss;
 267
 268         /* not an IBSS */
 269         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
 270                 goto put_bss;
 271
 272         /* different channel */
 273         if (bss->cbss.channel != local->oper_channel)
 274                 goto put_bss;
 275
 276         /* different SSID */
 277         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 278             memcmp(elems->ssid, sdata->u.ibss.ssid,
 279                                 sdata->u.ibss.ssid_len))
 280                 goto put_bss;
 281
 282         /* same BSSID */
 283         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 284                 goto put_bss;
 285
 286         if (rx_status->flag & RX_FLAG_TSFT) {
 287                 /*
 288                  * For correct IBSS merging we need mactime; since mactime is
 289                  * defined as the time the first data symbol of the frame hits
 290                  * the PHY, and the timestamp of the beacon is defined as "the
 291                  * time that the data symbol containing the first bit of the
 292                  * timestamp is transmitted to the PHY plus the transmitting
 293                  * STA's delays through its local PHY from the MAC-PHY
 294                  * interface to its interface with the WM" (802.11 11.1.2)
 295                  * - equals the time this bit arrives at the receiver - we have
 296                  * to take into account the offset between the two.
 297                  *
 298                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 299                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 300                  */
 301                 int rate;
 302
 303                 if (rx_status->flag & RX_FLAG_HT)
 304                         rate = 65; /* TODO: HT rates */
 305                 else
 306                         rate = local->hw.wiphy->bands[band]->
 307                                 bitrates[rx_status->rate_idx].bitrate;
 308
 309                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 310         } else if (local && local->ops && local->ops->get_tsf)
 311                 /* second best option: get current TSF */
 312                 rx_timestamp = local->ops->get_tsf(local_to_hw(local));
 313         else
 314                 /* can't merge without knowing the TSF */
 315                 rx_timestamp = -1LLU;
 316
 317 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 318         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 319                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 320                mgmt->sa, mgmt->bssid,
 321                (unsigned long long)rx_timestamp,
 322                (unsigned long long)beacon_timestamp,
 323                (unsigned long long)(rx_timestamp - beacon_timestamp),
 324                jiffies);
 325 #endif
 326
 327         /* give slow hardware some time to do the TSF sync */
 328         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 329                 goto put_bss;
 330
 331         if (beacon_timestamp > rx_timestamp) {
 332 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 333                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 334                        "local TSF - IBSS merge with BSSID %pM\n",
 335                        sdata->dev->name, mgmt->bssid);
 336 #endif
 337                 ieee80211_sta_join_ibss(sdata, bss);
 338                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 339         }
 340
 341  put_bss:
 342         ieee80211_rx_bss_put(local, bss);
 343 }
 344
 345 /*
 346  * Add a new IBSS station, will also be called by the RX code when,
 347  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 348  * must be callable in atomic context.
 349  */
 350 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 351                                         u8 *bssid,u8 *addr, u32 supp_rates)
 352 {
 353         struct ieee80211_local *local = sdata->local;
 354         struct sta_info *sta;
 355         int band = local->hw.conf.channel->band;
 356
 357         /*
 358          * XXX: Consider removing the least recently used entry and
 359          *      allow new one to be added.
 360          */
 361         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 362                 if (net_ratelimit())
 363                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 364                                sdata->dev->name, addr);
 365                 return NULL;
 366         }
 367
 368         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 369                 return NULL;
 370
 371 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 372         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 373                wiphy_name(local->hw.wiphy), addr, sdata->dev->name);
 374 #endif
 375
 376         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 377         if (!sta)
 378                 return NULL;
 379
 380         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 381
 382         /* make sure mandatory rates are always added */
 383         sta->sta.supp_rates[band] = supp_rates |
 384                         ieee80211_mandatory_rates(local, band);
 385
 386         rate_control_rate_init(sta);
 387
 388         if (sta_info_insert(sta))
 389                 return NULL;
 390
 391         return sta;
 392 }
 393
 394 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 395 {
 396         struct ieee80211_local *local = sdata->local;
 397         int active = 0;
 398         struct sta_info *sta;
 399
 400         rcu_read_lock();
 401
 402         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 403                 if (sta->sdata == sdata &&
 404                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 405                                jiffies)) {
 406                         active++;
 407                         break;
 408                 }
 409         }
 410
 411         rcu_read_unlock();
 412
 413         return active;
 414 }
 415
 416
 417 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 418 {
 419         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 420
 421         mod_timer(&ifibss->timer,
 422                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 423
 424         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 425
 426         if (ieee80211_sta_active_ibss(sdata))
 427                 return;
 428
 429         if (ifibss->fixed_channel)
 430                 return;
 431
 432         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 433                "IBSS networks with same SSID (merge)\n", sdata->dev->name);
 434
 435         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 436 }
 437
 438 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 439 {
 440         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 441         struct ieee80211_local *local = sdata->local;
 442         struct ieee80211_supported_band *sband;
 443         u8 *pos;
 444         u8 bssid[ETH_ALEN];
 445         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
 446         u16 capability;
 447         int i;
 448
 449         if (ifibss->fixed_bssid) {
 450                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 451         } else {
 452                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 453                  * own MAC address to make sure that devices that do not have proper
 454                  * random number generator get different BSSID. */
 455                 get_random_bytes(bssid, ETH_ALEN);
 456                 for (i = 0; i < ETH_ALEN; i++)
 457                         bssid[i] ^= sdata->dev->dev_addr[i];
 458                 bssid[0] &= ~0x01;
 459                 bssid[0] |= 0x02;
 460         }
 461
 462         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 463                sdata->dev->name, bssid);
 464
 465         sband = local->hw.wiphy->bands[ifibss->channel->band];
 466
 467         if (local->hw.conf.beacon_int == 0)
 468                 local->hw.conf.beacon_int = 100;
 469
 470         capability = WLAN_CAPABILITY_IBSS;
 471
 472         if (sdata->default_key)
 473                 capability |= WLAN_CAPABILITY_PRIVACY;
 474         else
 475                 sdata->drop_unencrypted = 0;
 476
 477         pos = supp_rates;
 478         for (i = 0; i < sband->n_bitrates; i++) {
 479                 int rate = sband->bitrates[i].bitrate;
 480                 *pos++ = (u8) (rate / 5);
 481         }
 482
 483         __ieee80211_sta_join_ibss(sdata, bssid, local->hw.conf.beacon_int,
 484                                   ifibss->channel, sband->n_bitrates,
 485                                   supp_rates, capability, 0);
 486 }
 487
 488 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 489 {
 490         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 491         struct ieee80211_local *local = sdata->local;
 492         struct ieee80211_bss *bss;
 493         struct ieee80211_channel *chan = NULL;
 494         const u8 *bssid = NULL;
 495         int active_ibss;
 496
 497         active_ibss = ieee80211_sta_active_ibss(sdata);
 498 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 499         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 500                sdata->dev->name, active_ibss);
 501 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 502
 503         if (active_ibss)
 504                 return;
 505
 506         if (ifibss->fixed_bssid)
 507                 bssid = ifibss->bssid;
 508         if (ifibss->fixed_channel)
 509                 chan = ifibss->channel;
 510         if (!is_zero_ether_addr(ifibss->bssid))
 511                 bssid = ifibss->bssid;
 512         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 513                                        ifibss->ssid, ifibss->ssid_len,
 514                                        WLAN_CAPABILITY_IBSS,
 515                                        WLAN_CAPABILITY_IBSS);
 516
 517 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 518         if (bss)
 519                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 520                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
 521 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 522
 523         if (bss && memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN)) {
 524                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 525                        " based on configured SSID\n",
 526                        sdata->dev->name, bss->cbss.bssid);
 527
 528                 ieee80211_sta_join_ibss(sdata, bss);
 529                 ieee80211_rx_bss_put(local, bss);
 530                 return;
 531         } else if (bss)
 532                 ieee80211_rx_bss_put(local, bss);
 533
 534 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 535         printk(KERN_DEBUG "   did not try to join ibss\n");
 536 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 537
 538         /* Selected IBSS not found in current scan results - try to scan */
 539         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 540             !ieee80211_sta_active_ibss(sdata)) {
 541                 mod_timer(&ifibss->timer,
 542                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 543         } else if (time_after(jiffies, ifibss->last_scan_completed +
 544                                         IEEE80211_SCAN_INTERVAL)) {
 545                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 546                        "join\n", sdata->dev->name);
 547
 548                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 549                                                 ifibss->ssid_len);
 550         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 551                 int interval = IEEE80211_SCAN_INTERVAL;
 552
 553                 if (time_after(jiffies, ifibss->ibss_join_req +
 554                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 555                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 556                                 ieee80211_sta_create_ibss(sdata);
 557                                 return;
 558                         }
 559                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 560                                " %d MHz\n", sdata->dev->name,
 561                                local->hw.conf.channel->center_freq);
 562
 563                         /* No IBSS found - decrease scan interval and continue
 564                          * scanning. */
 565                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 566                 }
 567
 568                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 569                 mod_timer(&ifibss->timer,
 570                           round_jiffies(jiffies + interval));
 571         }
 572 }
 573
 574 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 575                                         struct ieee80211_mgmt *mgmt,
 576                                         size_t len)
 577 {
 578         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 579         struct ieee80211_local *local = sdata->local;
 580         int tx_last_beacon;
 581         struct sk_buff *skb;
 582         struct ieee80211_mgmt *resp;
 583         u8 *pos, *end;
 584
 585         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 586             len < 24 + 2 || !ifibss->presp)
 587                 return;
 588
 589         if (local->ops->tx_last_beacon)
 590                 tx_last_beacon = local->ops->tx_last_beacon(local_to_hw(local));
 591         else
 592                 tx_last_beacon = 1;
 593
 594 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 595         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 596                " (tx_last_beacon=%d)\n",
 597                sdata->dev->name, mgmt->sa, mgmt->da,
 598                mgmt->bssid, tx_last_beacon);
 599 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 600
 601         if (!tx_last_beacon)
 602                 return;
 603
 604         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 605             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 606                 return;
 607
 608         end = ((u8 *) mgmt) + len;
 609         pos = mgmt->u.probe_req.variable;
 610         if (pos[0] != WLAN_EID_SSID ||
 611             pos + 2 + pos[1] > end) {
 612 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 613                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 614                        "from %pM\n",
 615                        sdata->dev->name, mgmt->sa);
 616 #endif
 617                 return;
 618         }
 619         if (pos[1] != 0 &&
 620             (pos[1] != ifibss->ssid_len ||
 621              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 622                 /* Ignore ProbeReq for foreign SSID */
 623                 return;
 624         }
 625
 626         /* Reply with ProbeResp */
 627         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 628         if (!skb)
 629                 return;
 630
 631         resp = (struct ieee80211_mgmt *) skb->data;
 632         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 633 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 634         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 635                sdata->dev->name, resp->da);
 636 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 637         ieee80211_tx_skb(sdata, skb, 0);
 638 }
 639
 640 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 641                                          struct ieee80211_mgmt *mgmt,
 642                                          size_t len,
 643                                          struct ieee80211_rx_status *rx_status)
 644 {
 645         size_t baselen;
 646         struct ieee802_11_elems elems;
 647
 648         if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 649                 return; /* ignore ProbeResp to foreign address */
 650
 651         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 652         if (baselen > len)
 653                 return;
 654
 655         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 656                                 &elems);
 657
 658         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 659 }
 660
 661 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 662                                      struct ieee80211_mgmt *mgmt,
 663                                      size_t len,
 664                                      struct ieee80211_rx_status *rx_status)
 665 {
 666         size_t baselen;
 667         struct ieee802_11_elems elems;
 668
 669         /* Process beacon from the current BSS */
 670         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 671         if (baselen > len)
 672                 return;
 673
 674         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 675
 676         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 677 }
 678
 679 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 680                                           struct sk_buff *skb)
 681 {
 682         struct ieee80211_rx_status *rx_status;
 683         struct ieee80211_mgmt *mgmt;
 684         u16 fc;
 685
 686         rx_status = (struct ieee80211_rx_status *) skb->cb;
 687         mgmt = (struct ieee80211_mgmt *) skb->data;
 688         fc = le16_to_cpu(mgmt->frame_control);
 689
 690         switch (fc & IEEE80211_FCTL_STYPE) {
 691         case IEEE80211_STYPE_PROBE_REQ:
 692                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 693                 break;
 694         case IEEE80211_STYPE_PROBE_RESP:
 695                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 696                                              rx_status);
 697                 break;
 698         case IEEE80211_STYPE_BEACON:
 699                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 700                                          rx_status);
 701                 break;
 702         case IEEE80211_STYPE_AUTH:
 703                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 704                 break;
 705         }
 706
 707         kfree_skb(skb);
 708 }
 709
 710 static void ieee80211_ibss_work(struct work_struct *work)
 711 {
 712         struct ieee80211_sub_if_data *sdata =
 713                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 714         struct ieee80211_local *local = sdata->local;
 715         struct ieee80211_if_ibss *ifibss;
 716         struct sk_buff *skb;
 717
 718         if (!netif_running(sdata->dev))
 719                 return;
 720
 721         if (local->sw_scanning || local->hw_scanning)
 722                 return;
 723
 724         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 725                 return;
 726         ifibss = &sdata->u.ibss;
 727
 728         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 729                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 730
 731         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 732                 return;
 733
 734         switch (ifibss->state) {
 735         case IEEE80211_IBSS_MLME_SEARCH:
 736                 ieee80211_sta_find_ibss(sdata);
 737                 break;
 738         case IEEE80211_IBSS_MLME_JOINED:
 739                 ieee80211_sta_merge_ibss(sdata);
 740                 break;
 741         default:
 742                 WARN_ON(1);
 743                 break;
 744         }
 745 }
 746
 747 static void ieee80211_ibss_timer(unsigned long data)
 748 {
 749         struct ieee80211_sub_if_data *sdata =
 750                 (struct ieee80211_sub_if_data *) data;
 751         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 752         struct ieee80211_local *local = sdata->local;
 753
 754         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 755         queue_work(local->hw.workqueue, &ifibss->work);
 756 }
 757
 758 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 759 {
 760         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 761
 762         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 763         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 764                     (unsigned long) sdata);
 765         skb_queue_head_init(&ifibss->skb_queue);
 766 }
 767
 768 /* scan finished notification */
 769 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 770 {
 771         struct ieee80211_sub_if_data *sdata;
 772
 773         mutex_lock(&local->iflist_mtx);
 774         list_for_each_entry(sdata, &local->interfaces, list) {
 775                 if (!netif_running(sdata->dev))
 776                         continue;
 777                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 778                         continue;
 779                 if (!sdata->u.ibss.ssid_len)
 780                         continue;
 781                 sdata->u.ibss.last_scan_completed = jiffies;
 782                 ieee80211_sta_find_ibss(sdata);
 783         }
 784         mutex_unlock(&local->iflist_mtx);
 785 }
 786
 787 ieee80211_rx_result
 788 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 789                        struct ieee80211_rx_status *rx_status)
 790 {
 791         struct ieee80211_local *local = sdata->local;
 792         struct ieee80211_mgmt *mgmt;
 793         u16 fc;
 794
 795         if (skb->len < 24)
 796                 return RX_DROP_MONITOR;
 797
 798         mgmt = (struct ieee80211_mgmt *) skb->data;
 799         fc = le16_to_cpu(mgmt->frame_control);
 800
 801         switch (fc & IEEE80211_FCTL_STYPE) {
 802         case IEEE80211_STYPE_PROBE_RESP:
 803         case IEEE80211_STYPE_BEACON:
 804                 memcpy(skb->cb, rx_status, sizeof(*rx_status));
 805         case IEEE80211_STYPE_PROBE_REQ:
 806         case IEEE80211_STYPE_AUTH:
 807                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 808                 queue_work(local->hw.workqueue, &sdata->u.ibss.work);
 809                 return RX_QUEUED;
 810         }
 811
 812         return RX_DROP_MONITOR;
 813 }
 814
 815 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 816                         struct cfg80211_ibss_params *params)
 817 {
 818         struct sk_buff *skb;
 819
 820         if (params->bssid) {
 821                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 822                 sdata->u.ibss.fixed_bssid = true;
 823         } else
 824                 sdata->u.ibss.fixed_bssid = false;
 825
 826         sdata->u.ibss.channel = params->channel;
 827         sdata->u.ibss.fixed_channel = params->channel_fixed;
 828
 829         if (params->ie) {
 830                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 831                                            GFP_KERNEL);
 832                 if (sdata->u.ibss.ie)
 833                         sdata->u.ibss.ie_len = params->ie_len;
 834         }
 835
 836         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 837                             36 /* bitrates */ +
 838                             34 /* SSID */ +
 839                             3  /* DS params */ +
 840                             4  /* IBSS params */ +
 841                             params->ie_len);
 842         if (!skb)
 843                 return -ENOMEM;
 844
 845         sdata->u.ibss.skb = skb;
 846         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 847         sdata->u.ibss.ibss_join_req = jiffies;
 848
 849         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 850
 851         /*
 852          * The ssid_len setting below is used to see whether
 853          * we are active, and we need all other settings
 854          * before that may get visible.
 855          */
 856         mb();
 857
 858         sdata->u.ibss.ssid_len = params->ssid_len;
 859
 860         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 861         queue_work(sdata->local->hw.workqueue, &sdata->u.ibss.work);
 862
 863         return 0;
 864 }
 865
 866 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 867 {
 868         struct sk_buff *skb;
 869
 870         del_timer_sync(&sdata->u.ibss.timer);
 871         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 872         cancel_work_sync(&sdata->u.ibss.work);
 873         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 874
 875         sta_info_flush(sdata->local, sdata);
 876
 877         /* remove beacon */
 878         kfree(sdata->u.ibss.ie);
 879         skb = sdata->u.ibss.presp;
 880         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 881         ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 882         synchronize_rcu();
 883         kfree_skb(skb);
 884
 885         skb_queue_purge(&sdata->u.ibss.skb_queue);
 886         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 887
 888         return 0;
 889 }