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/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         u32 bss_change;
  77
  78         if (local->ops->reset_tsf) {
  79                 /* Reset own TSF to allow time synchronization work. */
  80                 local->ops->reset_tsf(local_to_hw(local));
  81         }
  82
  83         skb = ifibss->skb;
  84         rcu_assign_pointer(ifibss->presp, NULL);
  85         synchronize_rcu();
  86         skb->data = skb->head;
  87         skb->len = 0;
  88         skb_reset_tail_pointer(skb);
  89         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  90
  91         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  92                 sta_info_flush(sdata->local, sdata);
  93
  94         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  95
  96         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  97
  98         local->oper_channel = chan;
  99         local->oper_channel_type = NL80211_CHAN_NO_HT;
 100         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 101
 102         sband = local->hw.wiphy->bands[chan->band];
 103
 104         /* Build IBSS probe response */
 105         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 106         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 107         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 108                                           IEEE80211_STYPE_PROBE_RESP);
 109         memset(mgmt->da, 0xff, ETH_ALEN);
 110         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 111         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 112         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 113         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 114         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 115
 116         pos = skb_put(skb, 2 + ifibss->ssid_len);
 117         *pos++ = WLAN_EID_SSID;
 118         *pos++ = ifibss->ssid_len;
 119         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 120
 121         rates = supp_rates_len;
 122         if (rates > 8)
 123                 rates = 8;
 124         pos = skb_put(skb, 2 + rates);
 125         *pos++ = WLAN_EID_SUPP_RATES;
 126         *pos++ = rates;
 127         memcpy(pos, supp_rates, rates);
 128
 129         if (sband->band == IEEE80211_BAND_2GHZ) {
 130                 pos = skb_put(skb, 2 + 1);
 131                 *pos++ = WLAN_EID_DS_PARAMS;
 132                 *pos++ = 1;
 133                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 134         }
 135
 136         pos = skb_put(skb, 2 + 2);
 137         *pos++ = WLAN_EID_IBSS_PARAMS;
 138         *pos++ = 2;
 139         /* FIX: set ATIM window based on scan results */
 140         *pos++ = 0;
 141         *pos++ = 0;
 142
 143         if (supp_rates_len > 8) {
 144                 rates = supp_rates_len - 8;
 145                 pos = skb_put(skb, 2 + rates);
 146                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 147                 *pos++ = rates;
 148                 memcpy(pos, &supp_rates[8], rates);
 149         }
 150
 151         if (ifibss->ie_len)
 152                 memcpy(skb_put(skb, ifibss->ie_len),
 153                        ifibss->ie, ifibss->ie_len);
 154
 155         rcu_assign_pointer(ifibss->presp, skb);
 156
 157         sdata->vif.bss_conf.beacon_int = beacon_int;
 158         bss_change = BSS_CHANGED_BEACON_INT;
 159         bss_change |= ieee80211_reset_erp_info(sdata);
 160         bss_change |= BSS_CHANGED_BSSID;
 161         bss_change |= BSS_CHANGED_BEACON;
 162         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 163         ieee80211_bss_info_change_notify(sdata, bss_change);
 164
 165         rates = 0;
 166         for (i = 0; i < supp_rates_len; i++) {
 167                 int bitrate = (supp_rates[i] & 0x7f) * 5;
 168                 for (j = 0; j < sband->n_bitrates; j++)
 169                         if (sband->bitrates[j].bitrate == bitrate)
 170                                 rates |= BIT(j);
 171         }
 172
 173         ieee80211_sta_def_wmm_params(sdata, supp_rates_len, supp_rates);
 174
 175         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 176         mod_timer(&ifibss->timer,
 177                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 178
 179         cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 180                                   mgmt, skb->len, 0, GFP_KERNEL);
 181         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 182 }
 183
 184 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 185                                     struct ieee80211_bss *bss)
 186 {
 187         u16 beacon_int = bss->cbss.beacon_interval;
 188
 189         if (beacon_int < 10)
 190                 beacon_int = 10;
 191
 192         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
 193                                   beacon_int,
 194                                   bss->cbss.channel,
 195                                   bss->supp_rates_len, bss->supp_rates,
 196                                   bss->cbss.capability,
 197                                   bss->cbss.tsf);
 198 }
 199
 200 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 201                                   struct ieee80211_mgmt *mgmt,
 202                                   size_t len,
 203                                   struct ieee80211_rx_status *rx_status,
 204                                   struct ieee802_11_elems *elems,
 205                                   bool beacon)
 206 {
 207         struct ieee80211_local *local = sdata->local;
 208         int freq;
 209         struct ieee80211_bss *bss;
 210         struct sta_info *sta;
 211         struct ieee80211_channel *channel;
 212         u64 beacon_timestamp, rx_timestamp;
 213         u32 supp_rates = 0;
 214         enum ieee80211_band band = rx_status->band;
 215
 216         if (elems->ds_params && elems->ds_params_len == 1)
 217                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 218         else
 219                 freq = rx_status->freq;
 220
 221         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 222
 223         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 224                 return;
 225
 226         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 227             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 228                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 229
 230                 rcu_read_lock();
 231
 232                 sta = sta_info_get(local, mgmt->sa);
 233                 if (sta) {
 234                         u32 prev_rates;
 235
 236                         prev_rates = sta->sta.supp_rates[band];
 237                         /* make sure mandatory rates are always added */
 238                         sta->sta.supp_rates[band] = supp_rates |
 239                                 ieee80211_mandatory_rates(local, band);
 240
 241 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 242                         if (sta->sta.supp_rates[band] != prev_rates)
 243                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 244                                     "for %pM based on beacon info (0x%llx | "
 245                                     "0x%llx -> 0x%llx)\n",
 246                                     sdata->dev->name,
 247                                     sta->sta.addr,
 248                                     (unsigned long long) prev_rates,
 249                                     (unsigned long long) supp_rates,
 250                                     (unsigned long long) sta->sta.supp_rates[band]);
 251 #endif
 252                 } else
 253                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 254
 255                 rcu_read_unlock();
 256         }
 257
 258         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 259                                         channel, beacon);
 260         if (!bss)
 261                 return;
 262
 263         /* was just updated in ieee80211_bss_info_update */
 264         beacon_timestamp = bss->cbss.tsf;
 265
 266         /* check if we need to merge IBSS */
 267
 268         /* merge only on beacons (???) */
 269         if (!beacon)
 270                 goto put_bss;
 271
 272         /* we use a fixed BSSID */
 273         if (sdata->u.ibss.bssid)
 274                 goto put_bss;
 275
 276         /* not an IBSS */
 277         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
 278                 goto put_bss;
 279
 280         /* different channel */
 281         if (bss->cbss.channel != local->oper_channel)
 282                 goto put_bss;
 283
 284         /* different SSID */
 285         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 286             memcmp(elems->ssid, sdata->u.ibss.ssid,
 287                                 sdata->u.ibss.ssid_len))
 288                 goto put_bss;
 289
 290         /* same BSSID */
 291         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 292                 goto put_bss;
 293
 294         if (rx_status->flag & RX_FLAG_TSFT) {
 295                 /*
 296                  * For correct IBSS merging we need mactime; since mactime is
 297                  * defined as the time the first data symbol of the frame hits
 298                  * the PHY, and the timestamp of the beacon is defined as "the
 299                  * time that the data symbol containing the first bit of the
 300                  * timestamp is transmitted to the PHY plus the transmitting
 301                  * STA's delays through its local PHY from the MAC-PHY
 302                  * interface to its interface with the WM" (802.11 11.1.2)
 303                  * - equals the time this bit arrives at the receiver - we have
 304                  * to take into account the offset between the two.
 305                  *
 306                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 307                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 308                  */
 309                 int rate;
 310
 311                 if (rx_status->flag & RX_FLAG_HT)
 312                         rate = 65; /* TODO: HT rates */
 313                 else
 314                         rate = local->hw.wiphy->bands[band]->
 315                                 bitrates[rx_status->rate_idx].bitrate;
 316
 317                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 318         } else if (local && local->ops && local->ops->get_tsf)
 319                 /* second best option: get current TSF */
 320                 rx_timestamp = local->ops->get_tsf(local_to_hw(local));
 321         else
 322                 /* can't merge without knowing the TSF */
 323                 rx_timestamp = -1LLU;
 324
 325 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 326         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 327                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 328                mgmt->sa, mgmt->bssid,
 329                (unsigned long long)rx_timestamp,
 330                (unsigned long long)beacon_timestamp,
 331                (unsigned long long)(rx_timestamp - beacon_timestamp),
 332                jiffies);
 333 #endif
 334
 335         /* give slow hardware some time to do the TSF sync */
 336         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 337                 goto put_bss;
 338
 339         if (beacon_timestamp > rx_timestamp) {
 340 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 341                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 342                        "local TSF - IBSS merge with BSSID %pM\n",
 343                        sdata->dev->name, mgmt->bssid);
 344 #endif
 345                 ieee80211_sta_join_ibss(sdata, bss);
 346                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 347         }
 348
 349  put_bss:
 350         ieee80211_rx_bss_put(local, bss);
 351 }
 352
 353 /*
 354  * Add a new IBSS station, will also be called by the RX code when,
 355  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 356  * must be callable in atomic context.
 357  */
 358 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 359                                         u8 *bssid,u8 *addr, u32 supp_rates)
 360 {
 361         struct ieee80211_local *local = sdata->local;
 362         struct sta_info *sta;
 363         int band = local->hw.conf.channel->band;
 364
 365         /*
 366          * XXX: Consider removing the least recently used entry and
 367          *      allow new one to be added.
 368          */
 369         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 370                 if (net_ratelimit())
 371                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 372                                sdata->dev->name, addr);
 373                 return NULL;
 374         }
 375
 376         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 377                 return NULL;
 378
 379 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 380         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 381                wiphy_name(local->hw.wiphy), addr, sdata->dev->name);
 382 #endif
 383
 384         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 385         if (!sta)
 386                 return NULL;
 387
 388         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 389
 390         /* make sure mandatory rates are always added */
 391         sta->sta.supp_rates[band] = supp_rates |
 392                         ieee80211_mandatory_rates(local, band);
 393
 394         rate_control_rate_init(sta);
 395
 396         if (sta_info_insert(sta))
 397                 return NULL;
 398
 399         return sta;
 400 }
 401
 402 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 403 {
 404         struct ieee80211_local *local = sdata->local;
 405         int active = 0;
 406         struct sta_info *sta;
 407
 408         rcu_read_lock();
 409
 410         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 411                 if (sta->sdata == sdata &&
 412                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 413                                jiffies)) {
 414                         active++;
 415                         break;
 416                 }
 417         }
 418
 419         rcu_read_unlock();
 420
 421         return active;
 422 }
 423
 424
 425 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 426 {
 427         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 428
 429         mod_timer(&ifibss->timer,
 430                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 431
 432         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 433
 434         if (ieee80211_sta_active_ibss(sdata))
 435                 return;
 436
 437         if (ifibss->fixed_channel)
 438                 return;
 439
 440         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 441                "IBSS networks with same SSID (merge)\n", sdata->dev->name);
 442
 443         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 444 }
 445
 446 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 447 {
 448         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 449         struct ieee80211_local *local = sdata->local;
 450         struct ieee80211_supported_band *sband;
 451         u8 *pos;
 452         u8 bssid[ETH_ALEN];
 453         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
 454         u16 capability;
 455         int i;
 456
 457         if (ifibss->fixed_bssid) {
 458                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 459         } else {
 460                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 461                  * own MAC address to make sure that devices that do not have proper
 462                  * random number generator get different BSSID. */
 463                 get_random_bytes(bssid, ETH_ALEN);
 464                 for (i = 0; i < ETH_ALEN; i++)
 465                         bssid[i] ^= sdata->dev->dev_addr[i];
 466                 bssid[0] &= ~0x01;
 467                 bssid[0] |= 0x02;
 468         }
 469
 470         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 471                sdata->dev->name, bssid);
 472
 473         sband = local->hw.wiphy->bands[ifibss->channel->band];
 474
 475         capability = WLAN_CAPABILITY_IBSS;
 476
 477         if (sdata->default_key)
 478                 capability |= WLAN_CAPABILITY_PRIVACY;
 479         else
 480                 sdata->drop_unencrypted = 0;
 481
 482         pos = supp_rates;
 483         for (i = 0; i < sband->n_bitrates; i++) {
 484                 int rate = sband->bitrates[i].bitrate;
 485                 *pos++ = (u8) (rate / 5);
 486         }
 487
 488         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 489                                   ifibss->channel, sband->n_bitrates,
 490                                   supp_rates, capability, 0);
 491 }
 492
 493 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 494 {
 495         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 496         struct ieee80211_local *local = sdata->local;
 497         struct ieee80211_bss *bss;
 498         struct ieee80211_channel *chan = NULL;
 499         const u8 *bssid = NULL;
 500         int active_ibss;
 501
 502         active_ibss = ieee80211_sta_active_ibss(sdata);
 503 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 504         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 505                sdata->dev->name, active_ibss);
 506 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 507
 508         if (active_ibss)
 509                 return;
 510
 511         if (ifibss->fixed_bssid)
 512                 bssid = ifibss->bssid;
 513         if (ifibss->fixed_channel)
 514                 chan = ifibss->channel;
 515         if (!is_zero_ether_addr(ifibss->bssid))
 516                 bssid = ifibss->bssid;
 517         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 518                                        ifibss->ssid, ifibss->ssid_len,
 519                                        WLAN_CAPABILITY_IBSS,
 520                                        WLAN_CAPABILITY_IBSS);
 521
 522 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 523         if (bss)
 524                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 525                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
 526 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 527
 528         if (bss && memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN)) {
 529                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 530                        " based on configured SSID\n",
 531                        sdata->dev->name, bss->cbss.bssid);
 532
 533                 ieee80211_sta_join_ibss(sdata, bss);
 534                 ieee80211_rx_bss_put(local, bss);
 535                 return;
 536         } else if (bss)
 537                 ieee80211_rx_bss_put(local, bss);
 538
 539 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 540         printk(KERN_DEBUG "   did not try to join ibss\n");
 541 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 542
 543         /* Selected IBSS not found in current scan results - try to scan */
 544         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 545             !ieee80211_sta_active_ibss(sdata)) {
 546                 mod_timer(&ifibss->timer,
 547                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 548         } else if (time_after(jiffies, ifibss->last_scan_completed +
 549                                         IEEE80211_SCAN_INTERVAL)) {
 550                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 551                        "join\n", sdata->dev->name);
 552
 553                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 554                                                 ifibss->ssid_len);
 555         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 556                 int interval = IEEE80211_SCAN_INTERVAL;
 557
 558                 if (time_after(jiffies, ifibss->ibss_join_req +
 559                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 560                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 561                                 ieee80211_sta_create_ibss(sdata);
 562                                 return;
 563                         }
 564                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 565                                " %d MHz\n", sdata->dev->name,
 566                                local->hw.conf.channel->center_freq);
 567
 568                         /* No IBSS found - decrease scan interval and continue
 569                          * scanning. */
 570                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 571                 }
 572
 573                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 574                 mod_timer(&ifibss->timer,
 575                           round_jiffies(jiffies + interval));
 576         }
 577 }
 578
 579 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 580                                         struct ieee80211_mgmt *mgmt,
 581                                         size_t len)
 582 {
 583         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 584         struct ieee80211_local *local = sdata->local;
 585         int tx_last_beacon;
 586         struct sk_buff *skb;
 587         struct ieee80211_mgmt *resp;
 588         u8 *pos, *end;
 589
 590         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 591             len < 24 + 2 || !ifibss->presp)
 592                 return;
 593
 594         if (local->ops->tx_last_beacon)
 595                 tx_last_beacon = local->ops->tx_last_beacon(local_to_hw(local));
 596         else
 597                 tx_last_beacon = 1;
 598
 599 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 600         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 601                " (tx_last_beacon=%d)\n",
 602                sdata->dev->name, mgmt->sa, mgmt->da,
 603                mgmt->bssid, tx_last_beacon);
 604 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 605
 606         if (!tx_last_beacon)
 607                 return;
 608
 609         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 610             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 611                 return;
 612
 613         end = ((u8 *) mgmt) + len;
 614         pos = mgmt->u.probe_req.variable;
 615         if (pos[0] != WLAN_EID_SSID ||
 616             pos + 2 + pos[1] > end) {
 617 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 618                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 619                        "from %pM\n",
 620                        sdata->dev->name, mgmt->sa);
 621 #endif
 622                 return;
 623         }
 624         if (pos[1] != 0 &&
 625             (pos[1] != ifibss->ssid_len ||
 626              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 627                 /* Ignore ProbeReq for foreign SSID */
 628                 return;
 629         }
 630
 631         /* Reply with ProbeResp */
 632         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 633         if (!skb)
 634                 return;
 635
 636         resp = (struct ieee80211_mgmt *) skb->data;
 637         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 638 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 639         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 640                sdata->dev->name, resp->da);
 641 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 642         ieee80211_tx_skb(sdata, skb, 0);
 643 }
 644
 645 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 646                                          struct ieee80211_mgmt *mgmt,
 647                                          size_t len,
 648                                          struct ieee80211_rx_status *rx_status)
 649 {
 650         size_t baselen;
 651         struct ieee802_11_elems elems;
 652
 653         if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 654                 return; /* ignore ProbeResp to foreign address */
 655
 656         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 657         if (baselen > len)
 658                 return;
 659
 660         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 661                                 &elems);
 662
 663         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 664 }
 665
 666 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 667                                      struct ieee80211_mgmt *mgmt,
 668                                      size_t len,
 669                                      struct ieee80211_rx_status *rx_status)
 670 {
 671         size_t baselen;
 672         struct ieee802_11_elems elems;
 673
 674         /* Process beacon from the current BSS */
 675         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 676         if (baselen > len)
 677                 return;
 678
 679         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 680
 681         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 682 }
 683
 684 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 685                                           struct sk_buff *skb)
 686 {
 687         struct ieee80211_rx_status *rx_status;
 688         struct ieee80211_mgmt *mgmt;
 689         u16 fc;
 690
 691         rx_status = (struct ieee80211_rx_status *) skb->cb;
 692         mgmt = (struct ieee80211_mgmt *) skb->data;
 693         fc = le16_to_cpu(mgmt->frame_control);
 694
 695         switch (fc & IEEE80211_FCTL_STYPE) {
 696         case IEEE80211_STYPE_PROBE_REQ:
 697                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 698                 break;
 699         case IEEE80211_STYPE_PROBE_RESP:
 700                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 701                                              rx_status);
 702                 break;
 703         case IEEE80211_STYPE_BEACON:
 704                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 705                                          rx_status);
 706                 break;
 707         case IEEE80211_STYPE_AUTH:
 708                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 709                 break;
 710         }
 711
 712         kfree_skb(skb);
 713 }
 714
 715 static void ieee80211_ibss_work(struct work_struct *work)
 716 {
 717         struct ieee80211_sub_if_data *sdata =
 718                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 719         struct ieee80211_local *local = sdata->local;
 720         struct ieee80211_if_ibss *ifibss;
 721         struct sk_buff *skb;
 722
 723         if (!netif_running(sdata->dev))
 724                 return;
 725
 726         if (local->sw_scanning || local->hw_scanning)
 727                 return;
 728
 729         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 730                 return;
 731         ifibss = &sdata->u.ibss;
 732
 733         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 734                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 735
 736         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 737                 return;
 738
 739         switch (ifibss->state) {
 740         case IEEE80211_IBSS_MLME_SEARCH:
 741                 ieee80211_sta_find_ibss(sdata);
 742                 break;
 743         case IEEE80211_IBSS_MLME_JOINED:
 744                 ieee80211_sta_merge_ibss(sdata);
 745                 break;
 746         default:
 747                 WARN_ON(1);
 748                 break;
 749         }
 750 }
 751
 752 static void ieee80211_ibss_timer(unsigned long data)
 753 {
 754         struct ieee80211_sub_if_data *sdata =
 755                 (struct ieee80211_sub_if_data *) data;
 756         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 757         struct ieee80211_local *local = sdata->local;
 758
 759         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 760         queue_work(local->hw.workqueue, &ifibss->work);
 761 }
 762
 763 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 764 {
 765         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 766
 767         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 768         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 769                     (unsigned long) sdata);
 770         skb_queue_head_init(&ifibss->skb_queue);
 771 }
 772
 773 /* scan finished notification */
 774 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 775 {
 776         struct ieee80211_sub_if_data *sdata;
 777
 778         mutex_lock(&local->iflist_mtx);
 779         list_for_each_entry(sdata, &local->interfaces, list) {
 780                 if (!netif_running(sdata->dev))
 781                         continue;
 782                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 783                         continue;
 784                 if (!sdata->u.ibss.ssid_len)
 785                         continue;
 786                 sdata->u.ibss.last_scan_completed = jiffies;
 787                 ieee80211_sta_find_ibss(sdata);
 788         }
 789         mutex_unlock(&local->iflist_mtx);
 790 }
 791
 792 ieee80211_rx_result
 793 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 794                        struct ieee80211_rx_status *rx_status)
 795 {
 796         struct ieee80211_local *local = sdata->local;
 797         struct ieee80211_mgmt *mgmt;
 798         u16 fc;
 799
 800         if (skb->len < 24)
 801                 return RX_DROP_MONITOR;
 802
 803         mgmt = (struct ieee80211_mgmt *) skb->data;
 804         fc = le16_to_cpu(mgmt->frame_control);
 805
 806         switch (fc & IEEE80211_FCTL_STYPE) {
 807         case IEEE80211_STYPE_PROBE_RESP:
 808         case IEEE80211_STYPE_BEACON:
 809                 memcpy(skb->cb, rx_status, sizeof(*rx_status));
 810         case IEEE80211_STYPE_PROBE_REQ:
 811         case IEEE80211_STYPE_AUTH:
 812                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 813                 queue_work(local->hw.workqueue, &sdata->u.ibss.work);
 814                 return RX_QUEUED;
 815         }
 816
 817         return RX_DROP_MONITOR;
 818 }
 819
 820 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 821                         struct cfg80211_ibss_params *params)
 822 {
 823         struct sk_buff *skb;
 824
 825         if (params->bssid) {
 826                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 827                 sdata->u.ibss.fixed_bssid = true;
 828         } else
 829                 sdata->u.ibss.fixed_bssid = false;
 830
 831         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 832
 833         sdata->u.ibss.channel = params->channel;
 834         sdata->u.ibss.fixed_channel = params->channel_fixed;
 835
 836         if (params->ie) {
 837                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 838                                            GFP_KERNEL);
 839                 if (sdata->u.ibss.ie)
 840                         sdata->u.ibss.ie_len = params->ie_len;
 841         }
 842
 843         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 844                             36 /* bitrates */ +
 845                             34 /* SSID */ +
 846                             3  /* DS params */ +
 847                             4  /* IBSS params */ +
 848                             params->ie_len);
 849         if (!skb)
 850                 return -ENOMEM;
 851
 852         sdata->u.ibss.skb = skb;
 853         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 854         sdata->u.ibss.ibss_join_req = jiffies;
 855
 856         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 857
 858         /*
 859          * The ssid_len setting below is used to see whether
 860          * we are active, and we need all other settings
 861          * before that may get visible.
 862          */
 863         mb();
 864
 865         sdata->u.ibss.ssid_len = params->ssid_len;
 866
 867         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 868         queue_work(sdata->local->hw.workqueue, &sdata->u.ibss.work);
 869
 870         return 0;
 871 }
 872
 873 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 874 {
 875         struct sk_buff *skb;
 876
 877         del_timer_sync(&sdata->u.ibss.timer);
 878         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 879         cancel_work_sync(&sdata->u.ibss.work);
 880         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 881
 882         sta_info_flush(sdata->local, sdata);
 883
 884         /* remove beacon */
 885         kfree(sdata->u.ibss.ie);
 886         skb = sdata->u.ibss.presp;
 887         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 888         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 889         synchronize_rcu();
 890         kfree_skb(skb);
 891
 892         skb_queue_purge(&sdata->u.ibss.skb_queue);
 893         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 894
 895         return 0;
 896 }