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 "driver-ops.h"
  26 #include "rate.h"
  27
  28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  29 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  31
  32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  33 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  35
  36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  37
  38
  39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  40                                         struct ieee80211_mgmt *mgmt,
  41                                         size_t len)
  42 {
  43         u16 auth_alg, auth_transaction, status_code;
  44
  45         if (len < 24 + 6)
  46                 return;
  47
  48         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  49         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  50         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  51
  52         /*
  53          * IEEE 802.11 standard does not require authentication in IBSS
  54          * networks and most implementations do not seem to use it.
  55          * However, try to reply to authentication attempts if someone
  56          * has actually implemented this.
  57          */
  58         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  59                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  60                                     sdata->u.ibss.bssid, NULL, 0, 0);
  61 }
  62
  63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  64                                       const u8 *bssid, const int beacon_int,
  65                                       struct ieee80211_channel *chan,
  66                                       const u32 basic_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;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76         u32 bss_change;
  77         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  78
  79         /* Reset own TSF to allow time synchronization work. */
  80         drv_reset_tsf(local);
  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         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  96
  97         local->oper_channel = chan;
  98         local->oper_channel_type = NL80211_CHAN_NO_HT;
  99         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 100
 101         sband = local->hw.wiphy->bands[chan->band];
 102
 103         /* build supported rates array */
 104         pos = supp_rates;
 105         for (i = 0; i < sband->n_bitrates; i++) {
 106                 int rate = sband->bitrates[i].bitrate;
 107                 u8 basic = 0;
 108                 if (basic_rates & BIT(i))
 109                         basic = 0x80;
 110                 *pos++ = basic | (u8) (rate / 5);
 111         }
 112
 113         /* Build IBSS probe response */
 114         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 115         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 116         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 117                                           IEEE80211_STYPE_PROBE_RESP);
 118         memset(mgmt->da, 0xff, ETH_ALEN);
 119         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 120         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 121         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 122         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 123         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 124
 125         pos = skb_put(skb, 2 + ifibss->ssid_len);
 126         *pos++ = WLAN_EID_SSID;
 127         *pos++ = ifibss->ssid_len;
 128         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 129
 130         rates = sband->n_bitrates;
 131         if (rates > 8)
 132                 rates = 8;
 133         pos = skb_put(skb, 2 + rates);
 134         *pos++ = WLAN_EID_SUPP_RATES;
 135         *pos++ = rates;
 136         memcpy(pos, supp_rates, rates);
 137
 138         if (sband->band == IEEE80211_BAND_2GHZ) {
 139                 pos = skb_put(skb, 2 + 1);
 140                 *pos++ = WLAN_EID_DS_PARAMS;
 141                 *pos++ = 1;
 142                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 143         }
 144
 145         pos = skb_put(skb, 2 + 2);
 146         *pos++ = WLAN_EID_IBSS_PARAMS;
 147         *pos++ = 2;
 148         /* FIX: set ATIM window based on scan results */
 149         *pos++ = 0;
 150         *pos++ = 0;
 151
 152         if (sband->n_bitrates > 8) {
 153                 rates = sband->n_bitrates - 8;
 154                 pos = skb_put(skb, 2 + rates);
 155                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 156                 *pos++ = rates;
 157                 memcpy(pos, &supp_rates[8], rates);
 158         }
 159
 160         if (ifibss->ie_len)
 161                 memcpy(skb_put(skb, ifibss->ie_len),
 162                        ifibss->ie, ifibss->ie_len);
 163
 164         rcu_assign_pointer(ifibss->presp, skb);
 165
 166         sdata->vif.bss_conf.beacon_int = beacon_int;
 167         bss_change = BSS_CHANGED_BEACON_INT;
 168         bss_change |= ieee80211_reset_erp_info(sdata);
 169         bss_change |= BSS_CHANGED_BSSID;
 170         bss_change |= BSS_CHANGED_BEACON;
 171         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 172         ieee80211_bss_info_change_notify(sdata, bss_change);
 173
 174         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 175
 176         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 177         mod_timer(&ifibss->timer,
 178                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 179
 180         cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 181                                   mgmt, skb->len, 0, GFP_KERNEL);
 182         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 183 }
 184
 185 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 186                                     struct ieee80211_bss *bss)
 187 {
 188         struct ieee80211_supported_band *sband;
 189         u32 basic_rates;
 190         int i, j;
 191         u16 beacon_int = bss->cbss.beacon_interval;
 192
 193         if (beacon_int < 10)
 194                 beacon_int = 10;
 195
 196         sband = sdata->local->hw.wiphy->bands[bss->cbss.channel->band];
 197
 198         basic_rates = 0;
 199
 200         for (i = 0; i < bss->supp_rates_len; i++) {
 201                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 202                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 203
 204                 for (j = 0; j < sband->n_bitrates; j++) {
 205                         if (sband->bitrates[j].bitrate == rate) {
 206                                 if (is_basic)
 207                                         basic_rates |= BIT(j);
 208                                 break;
 209                         }
 210                 }
 211         }
 212
 213         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
 214                                   beacon_int,
 215                                   bss->cbss.channel,
 216                                   basic_rates,
 217                                   bss->cbss.capability,
 218                                   bss->cbss.tsf);
 219 }
 220
 221 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 222                                   struct ieee80211_mgmt *mgmt,
 223                                   size_t len,
 224                                   struct ieee80211_rx_status *rx_status,
 225                                   struct ieee802_11_elems *elems,
 226                                   bool beacon)
 227 {
 228         struct ieee80211_local *local = sdata->local;
 229         int freq;
 230         struct ieee80211_bss *bss;
 231         struct sta_info *sta;
 232         struct ieee80211_channel *channel;
 233         u64 beacon_timestamp, rx_timestamp;
 234         u32 supp_rates = 0;
 235         enum ieee80211_band band = rx_status->band;
 236
 237         if (elems->ds_params && elems->ds_params_len == 1)
 238                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 239         else
 240                 freq = rx_status->freq;
 241
 242         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 243
 244         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 245                 return;
 246
 247         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 248             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 249                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 250
 251                 rcu_read_lock();
 252
 253                 sta = sta_info_get(local, mgmt->sa);
 254                 if (sta) {
 255                         u32 prev_rates;
 256
 257                         prev_rates = sta->sta.supp_rates[band];
 258                         /* make sure mandatory rates are always added */
 259                         sta->sta.supp_rates[band] = supp_rates |
 260                                 ieee80211_mandatory_rates(local, band);
 261
 262 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 263                         if (sta->sta.supp_rates[band] != prev_rates)
 264                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 265                                     "for %pM based on beacon info (0x%llx | "
 266                                     "0x%llx -> 0x%llx)\n",
 267                                     sdata->dev->name,
 268                                     sta->sta.addr,
 269                                     (unsigned long long) prev_rates,
 270                                     (unsigned long long) supp_rates,
 271                                     (unsigned long long) sta->sta.supp_rates[band]);
 272 #endif
 273                 } else
 274                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 275
 276                 rcu_read_unlock();
 277         }
 278
 279         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 280                                         channel, beacon);
 281         if (!bss)
 282                 return;
 283
 284         /* was just updated in ieee80211_bss_info_update */
 285         beacon_timestamp = bss->cbss.tsf;
 286
 287         /* check if we need to merge IBSS */
 288
 289         /* merge only on beacons (???) */
 290         if (!beacon)
 291                 goto put_bss;
 292
 293         /* we use a fixed BSSID */
 294         if (sdata->u.ibss.bssid)
 295                 goto put_bss;
 296
 297         /* not an IBSS */
 298         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
 299                 goto put_bss;
 300
 301         /* different channel */
 302         if (bss->cbss.channel != local->oper_channel)
 303                 goto put_bss;
 304
 305         /* different SSID */
 306         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 307             memcmp(elems->ssid, sdata->u.ibss.ssid,
 308                                 sdata->u.ibss.ssid_len))
 309                 goto put_bss;
 310
 311         /* same BSSID */
 312         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 313                 goto put_bss;
 314
 315         if (rx_status->flag & RX_FLAG_TSFT) {
 316                 /*
 317                  * For correct IBSS merging we need mactime; since mactime is
 318                  * defined as the time the first data symbol of the frame hits
 319                  * the PHY, and the timestamp of the beacon is defined as "the
 320                  * time that the data symbol containing the first bit of the
 321                  * timestamp is transmitted to the PHY plus the transmitting
 322                  * STA's delays through its local PHY from the MAC-PHY
 323                  * interface to its interface with the WM" (802.11 11.1.2)
 324                  * - equals the time this bit arrives at the receiver - we have
 325                  * to take into account the offset between the two.
 326                  *
 327                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 328                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 329                  */
 330                 int rate;
 331
 332                 if (rx_status->flag & RX_FLAG_HT)
 333                         rate = 65; /* TODO: HT rates */
 334                 else
 335                         rate = local->hw.wiphy->bands[band]->
 336                                 bitrates[rx_status->rate_idx].bitrate;
 337
 338                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 339         } else {
 340                 /*
 341                  * second best option: get current TSF
 342                  * (will return -1 if not supported)
 343                  */
 344                 rx_timestamp = drv_get_tsf(local);
 345         }
 346
 347 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 348         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 349                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 350                mgmt->sa, mgmt->bssid,
 351                (unsigned long long)rx_timestamp,
 352                (unsigned long long)beacon_timestamp,
 353                (unsigned long long)(rx_timestamp - beacon_timestamp),
 354                jiffies);
 355 #endif
 356
 357         /* give slow hardware some time to do the TSF sync */
 358         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 359                 goto put_bss;
 360
 361         if (beacon_timestamp > rx_timestamp) {
 362 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 363                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 364                        "local TSF - IBSS merge with BSSID %pM\n",
 365                        sdata->dev->name, mgmt->bssid);
 366 #endif
 367                 ieee80211_sta_join_ibss(sdata, bss);
 368                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 369         }
 370
 371  put_bss:
 372         ieee80211_rx_bss_put(local, bss);
 373 }
 374
 375 /*
 376  * Add a new IBSS station, will also be called by the RX code when,
 377  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 378  * must be callable in atomic context.
 379  */
 380 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 381                                         u8 *bssid,u8 *addr, u32 supp_rates)
 382 {
 383         struct ieee80211_local *local = sdata->local;
 384         struct sta_info *sta;
 385         int band = local->hw.conf.channel->band;
 386
 387         /*
 388          * XXX: Consider removing the least recently used entry and
 389          *      allow new one to be added.
 390          */
 391         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 392                 if (net_ratelimit())
 393                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 394                                sdata->dev->name, addr);
 395                 return NULL;
 396         }
 397
 398         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 399                 return NULL;
 400
 401 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 402         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 403                wiphy_name(local->hw.wiphy), addr, sdata->dev->name);
 404 #endif
 405
 406         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 407         if (!sta)
 408                 return NULL;
 409
 410         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 411
 412         /* make sure mandatory rates are always added */
 413         sta->sta.supp_rates[band] = supp_rates |
 414                         ieee80211_mandatory_rates(local, band);
 415
 416         rate_control_rate_init(sta);
 417
 418         if (sta_info_insert(sta))
 419                 return NULL;
 420
 421         return sta;
 422 }
 423
 424 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 425 {
 426         struct ieee80211_local *local = sdata->local;
 427         int active = 0;
 428         struct sta_info *sta;
 429
 430         rcu_read_lock();
 431
 432         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 433                 if (sta->sdata == sdata &&
 434                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 435                                jiffies)) {
 436                         active++;
 437                         break;
 438                 }
 439         }
 440
 441         rcu_read_unlock();
 442
 443         return active;
 444 }
 445
 446
 447 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 448 {
 449         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 450
 451         mod_timer(&ifibss->timer,
 452                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 453
 454         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 455
 456         if (ieee80211_sta_active_ibss(sdata))
 457                 return;
 458
 459         if (ifibss->fixed_channel)
 460                 return;
 461
 462         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 463                "IBSS networks with same SSID (merge)\n", sdata->dev->name);
 464
 465         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 466 }
 467
 468 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 469 {
 470         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 471         struct ieee80211_local *local = sdata->local;
 472         struct ieee80211_supported_band *sband;
 473         u8 bssid[ETH_ALEN];
 474         u16 capability;
 475         int i;
 476
 477         if (ifibss->fixed_bssid) {
 478                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 479         } else {
 480                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 481                  * own MAC address to make sure that devices that do not have proper
 482                  * random number generator get different BSSID. */
 483                 get_random_bytes(bssid, ETH_ALEN);
 484                 for (i = 0; i < ETH_ALEN; i++)
 485                         bssid[i] ^= sdata->dev->dev_addr[i];
 486                 bssid[0] &= ~0x01;
 487                 bssid[0] |= 0x02;
 488         }
 489
 490         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 491                sdata->dev->name, bssid);
 492
 493         sband = local->hw.wiphy->bands[ifibss->channel->band];
 494
 495         capability = WLAN_CAPABILITY_IBSS;
 496
 497         if (ifibss->privacy)
 498                 capability |= WLAN_CAPABILITY_PRIVACY;
 499         else
 500                 sdata->drop_unencrypted = 0;
 501
 502         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 503                                   ifibss->channel, 3, /* first two are basic */
 504                                   capability, 0);
 505 }
 506
 507 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 508 {
 509         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 510         struct ieee80211_local *local = sdata->local;
 511         struct ieee80211_bss *bss;
 512         struct ieee80211_channel *chan = NULL;
 513         const u8 *bssid = NULL;
 514         int active_ibss;
 515         u16 capability;
 516
 517         active_ibss = ieee80211_sta_active_ibss(sdata);
 518 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 519         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 520                sdata->dev->name, active_ibss);
 521 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 522
 523         if (active_ibss)
 524                 return;
 525
 526         capability = WLAN_CAPABILITY_IBSS;
 527         if (ifibss->privacy)
 528                 capability |= WLAN_CAPABILITY_PRIVACY;
 529         if (ifibss->fixed_bssid)
 530                 bssid = ifibss->bssid;
 531         if (ifibss->fixed_channel)
 532                 chan = ifibss->channel;
 533         if (!is_zero_ether_addr(ifibss->bssid))
 534                 bssid = ifibss->bssid;
 535         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 536                                        ifibss->ssid, ifibss->ssid_len,
 537                                        WLAN_CAPABILITY_IBSS |
 538                                        WLAN_CAPABILITY_PRIVACY,
 539                                        capability);
 540
 541 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 542         if (bss)
 543                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 544                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
 545 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 546
 547         if (bss && !memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN)) {
 548                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 549                        " based on configured SSID\n",
 550                        sdata->dev->name, bss->cbss.bssid);
 551
 552                 ieee80211_sta_join_ibss(sdata, bss);
 553                 ieee80211_rx_bss_put(local, bss);
 554                 return;
 555         } else if (bss)
 556                 ieee80211_rx_bss_put(local, bss);
 557
 558 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 559         printk(KERN_DEBUG "   did not try to join ibss\n");
 560 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 561
 562         /* Selected IBSS not found in current scan results - try to scan */
 563         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 564             !ieee80211_sta_active_ibss(sdata)) {
 565                 mod_timer(&ifibss->timer,
 566                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 567         } else if (time_after(jiffies, ifibss->last_scan_completed +
 568                                         IEEE80211_SCAN_INTERVAL)) {
 569                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 570                        "join\n", sdata->dev->name);
 571
 572                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 573                                                 ifibss->ssid_len);
 574         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 575                 int interval = IEEE80211_SCAN_INTERVAL;
 576
 577                 if (time_after(jiffies, ifibss->ibss_join_req +
 578                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 579                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 580                                 ieee80211_sta_create_ibss(sdata);
 581                                 return;
 582                         }
 583                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 584                                " %d MHz\n", sdata->dev->name,
 585                                local->hw.conf.channel->center_freq);
 586
 587                         /* No IBSS found - decrease scan interval and continue
 588                          * scanning. */
 589                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 590                 }
 591
 592                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 593                 mod_timer(&ifibss->timer,
 594                           round_jiffies(jiffies + interval));
 595         }
 596 }
 597
 598 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 599                                         struct ieee80211_mgmt *mgmt,
 600                                         size_t len)
 601 {
 602         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 603         struct ieee80211_local *local = sdata->local;
 604         int tx_last_beacon;
 605         struct sk_buff *skb;
 606         struct ieee80211_mgmt *resp;
 607         u8 *pos, *end;
 608
 609         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 610             len < 24 + 2 || !ifibss->presp)
 611                 return;
 612
 613         tx_last_beacon = drv_tx_last_beacon(local);
 614
 615 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 616         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 617                " (tx_last_beacon=%d)\n",
 618                sdata->dev->name, mgmt->sa, mgmt->da,
 619                mgmt->bssid, tx_last_beacon);
 620 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 621
 622         if (!tx_last_beacon)
 623                 return;
 624
 625         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 626             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 627                 return;
 628
 629         end = ((u8 *) mgmt) + len;
 630         pos = mgmt->u.probe_req.variable;
 631         if (pos[0] != WLAN_EID_SSID ||
 632             pos + 2 + pos[1] > end) {
 633 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 634                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 635                        "from %pM\n",
 636                        sdata->dev->name, mgmt->sa);
 637 #endif
 638                 return;
 639         }
 640         if (pos[1] != 0 &&
 641             (pos[1] != ifibss->ssid_len ||
 642              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 643                 /* Ignore ProbeReq for foreign SSID */
 644                 return;
 645         }
 646
 647         /* Reply with ProbeResp */
 648         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 649         if (!skb)
 650                 return;
 651
 652         resp = (struct ieee80211_mgmt *) skb->data;
 653         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 654 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 655         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 656                sdata->dev->name, resp->da);
 657 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 658         ieee80211_tx_skb(sdata, skb, 0);
 659 }
 660
 661 static void ieee80211_rx_mgmt_probe_resp(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         if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 670                 return; /* ignore ProbeResp to foreign address */
 671
 672         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 673         if (baselen > len)
 674                 return;
 675
 676         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 677                                 &elems);
 678
 679         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 680 }
 681
 682 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 683                                      struct ieee80211_mgmt *mgmt,
 684                                      size_t len,
 685                                      struct ieee80211_rx_status *rx_status)
 686 {
 687         size_t baselen;
 688         struct ieee802_11_elems elems;
 689
 690         /* Process beacon from the current BSS */
 691         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 692         if (baselen > len)
 693                 return;
 694
 695         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 696
 697         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 698 }
 699
 700 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 701                                           struct sk_buff *skb)
 702 {
 703         struct ieee80211_rx_status *rx_status;
 704         struct ieee80211_mgmt *mgmt;
 705         u16 fc;
 706
 707         rx_status = IEEE80211_SKB_RXCB(skb);
 708         mgmt = (struct ieee80211_mgmt *) skb->data;
 709         fc = le16_to_cpu(mgmt->frame_control);
 710
 711         switch (fc & IEEE80211_FCTL_STYPE) {
 712         case IEEE80211_STYPE_PROBE_REQ:
 713                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 714                 break;
 715         case IEEE80211_STYPE_PROBE_RESP:
 716                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 717                                              rx_status);
 718                 break;
 719         case IEEE80211_STYPE_BEACON:
 720                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 721                                          rx_status);
 722                 break;
 723         case IEEE80211_STYPE_AUTH:
 724                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 725                 break;
 726         }
 727
 728         kfree_skb(skb);
 729 }
 730
 731 static void ieee80211_ibss_work(struct work_struct *work)
 732 {
 733         struct ieee80211_sub_if_data *sdata =
 734                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 735         struct ieee80211_local *local = sdata->local;
 736         struct ieee80211_if_ibss *ifibss;
 737         struct sk_buff *skb;
 738
 739         if (WARN_ON(local->suspended))
 740                 return;
 741
 742         if (!netif_running(sdata->dev))
 743                 return;
 744
 745         if (local->scanning)
 746                 return;
 747
 748         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 749                 return;
 750         ifibss = &sdata->u.ibss;
 751
 752         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 753                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 754
 755         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 756                 return;
 757
 758         switch (ifibss->state) {
 759         case IEEE80211_IBSS_MLME_SEARCH:
 760                 ieee80211_sta_find_ibss(sdata);
 761                 break;
 762         case IEEE80211_IBSS_MLME_JOINED:
 763                 ieee80211_sta_merge_ibss(sdata);
 764                 break;
 765         default:
 766                 WARN_ON(1);
 767                 break;
 768         }
 769 }
 770
 771 static void ieee80211_ibss_timer(unsigned long data)
 772 {
 773         struct ieee80211_sub_if_data *sdata =
 774                 (struct ieee80211_sub_if_data *) data;
 775         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 776         struct ieee80211_local *local = sdata->local;
 777
 778         if (local->quiescing) {
 779                 ifibss->timer_running = true;
 780                 return;
 781         }
 782
 783         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 784         ieee80211_queue_work(&local->hw, &ifibss->work);
 785 }
 786
 787 #ifdef CONFIG_PM
 788 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 789 {
 790         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 791
 792         cancel_work_sync(&ifibss->work);
 793         if (del_timer_sync(&ifibss->timer))
 794                 ifibss->timer_running = true;
 795 }
 796
 797 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 798 {
 799         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 800
 801         if (ifibss->timer_running) {
 802                 add_timer(&ifibss->timer);
 803                 ifibss->timer_running = false;
 804         }
 805 }
 806 #endif
 807
 808 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 809 {
 810         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 811
 812         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 813         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 814                     (unsigned long) sdata);
 815         skb_queue_head_init(&ifibss->skb_queue);
 816 }
 817
 818 /* scan finished notification */
 819 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 820 {
 821         struct ieee80211_sub_if_data *sdata;
 822
 823         mutex_lock(&local->iflist_mtx);
 824         list_for_each_entry(sdata, &local->interfaces, list) {
 825                 if (!netif_running(sdata->dev))
 826                         continue;
 827                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 828                         continue;
 829                 if (!sdata->u.ibss.ssid_len)
 830                         continue;
 831                 sdata->u.ibss.last_scan_completed = jiffies;
 832                 mod_timer(&sdata->u.ibss.timer, 0);
 833         }
 834         mutex_unlock(&local->iflist_mtx);
 835 }
 836
 837 ieee80211_rx_result
 838 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 839 {
 840         struct ieee80211_local *local = sdata->local;
 841         struct ieee80211_mgmt *mgmt;
 842         u16 fc;
 843
 844         if (skb->len < 24)
 845                 return RX_DROP_MONITOR;
 846
 847         mgmt = (struct ieee80211_mgmt *) skb->data;
 848         fc = le16_to_cpu(mgmt->frame_control);
 849
 850         switch (fc & IEEE80211_FCTL_STYPE) {
 851         case IEEE80211_STYPE_PROBE_RESP:
 852         case IEEE80211_STYPE_BEACON:
 853         case IEEE80211_STYPE_PROBE_REQ:
 854         case IEEE80211_STYPE_AUTH:
 855                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 856                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 857                 return RX_QUEUED;
 858         }
 859
 860         return RX_DROP_MONITOR;
 861 }
 862
 863 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 864                         struct cfg80211_ibss_params *params)
 865 {
 866         struct sk_buff *skb;
 867
 868         if (params->bssid) {
 869                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 870                 sdata->u.ibss.fixed_bssid = true;
 871         } else
 872                 sdata->u.ibss.fixed_bssid = false;
 873
 874         sdata->u.ibss.privacy = params->privacy;
 875
 876         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 877
 878         sdata->u.ibss.channel = params->channel;
 879         sdata->u.ibss.fixed_channel = params->channel_fixed;
 880
 881         if (params->ie) {
 882                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 883                                            GFP_KERNEL);
 884                 if (sdata->u.ibss.ie)
 885                         sdata->u.ibss.ie_len = params->ie_len;
 886         }
 887
 888         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 889                             36 /* bitrates */ +
 890                             34 /* SSID */ +
 891                             3  /* DS params */ +
 892                             4  /* IBSS params */ +
 893                             params->ie_len);
 894         if (!skb)
 895                 return -ENOMEM;
 896
 897         sdata->u.ibss.skb = skb;
 898         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 899         sdata->u.ibss.ibss_join_req = jiffies;
 900
 901         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 902
 903         /*
 904          * The ssid_len setting below is used to see whether
 905          * we are active, and we need all other settings
 906          * before that may get visible.
 907          */
 908         mb();
 909
 910         sdata->u.ibss.ssid_len = params->ssid_len;
 911
 912         ieee80211_recalc_idle(sdata->local);
 913
 914         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 915         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 916
 917         return 0;
 918 }
 919
 920 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 921 {
 922         struct sk_buff *skb;
 923
 924         del_timer_sync(&sdata->u.ibss.timer);
 925         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 926         cancel_work_sync(&sdata->u.ibss.work);
 927         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 928
 929         sta_info_flush(sdata->local, sdata);
 930
 931         /* remove beacon */
 932         kfree(sdata->u.ibss.ie);
 933         skb = sdata->u.ibss.presp;
 934         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 935         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 936         synchronize_rcu();
 937         kfree_skb(skb);
 938
 939         skb_queue_purge(&sdata->u.ibss.skb_queue);
 940         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 941         sdata->u.ibss.ssid_len = 0;
 942
 943         ieee80211_recalc_idle(sdata->local);
 944
 945         return 0;
 946 }