net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/slab.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/rtnetlink.h>
  22 #include <net/mac80211.h>
  23 #include <asm/unaligned.h>
  24
  25 #include "ieee80211_i.h"
  26 #include "driver-ops.h"
  27 #include "rate.h"
  28
  29 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  30 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  31 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  32
  33 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  34 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  35 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  36
  37 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  38
  39
  40 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  41                                         struct ieee80211_mgmt *mgmt,
  42                                         size_t len)
  43 {
  44         u16 auth_alg, auth_transaction, status_code;
  45
  46         if (len < 24 + 6)
  47                 return;
  48
  49         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  50         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  51         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  52
  53         /*
  54          * IEEE 802.11 standard does not require authentication in IBSS
  55          * networks and most implementations do not seem to use it.
  56          * However, try to reply to authentication attempts if someone
  57          * has actually implemented this.
  58          */
  59         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  60                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  61                                     sdata->u.ibss.bssid, NULL, 0, 0);
  62 }
  63
  64 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  65                                       const u8 *bssid, const int beacon_int,
  66                                       struct ieee80211_channel *chan,
  67                                       const u32 basic_rates,
  68                                       const u16 capability, u64 tsf)
  69 {
  70         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  71         struct ieee80211_local *local = sdata->local;
  72         int rates, i;
  73         struct sk_buff *skb;
  74         struct ieee80211_mgmt *mgmt;
  75         u8 *pos;
  76         struct ieee80211_supported_band *sband;
  77         struct cfg80211_bss *bss;
  78         u32 bss_change;
  79         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  80
  81         /* Reset own TSF to allow time synchronization work. */
  82         drv_reset_tsf(local);
  83
  84         skb = ifibss->skb;
  85         rcu_assign_pointer(ifibss->presp, NULL);
  86         synchronize_rcu();
  87         skb->data = skb->head;
  88         skb->len = 0;
  89         skb_reset_tail_pointer(skb);
  90         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  91
  92         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  93                 sta_info_flush(sdata->local, sdata);
  94
  95         /* if merging, indicate to driver that we leave the old IBSS */
  96         if (sdata->vif.bss_conf.ibss_joined) {
  97                 sdata->vif.bss_conf.ibss_joined = false;
  98                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
  99         }
 100
 101         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 102
 103         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 104
 105         local->oper_channel = chan;
 106         WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
 107         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 108
 109         sband = local->hw.wiphy->bands[chan->band];
 110
 111         /* build supported rates array */
 112         pos = supp_rates;
 113         for (i = 0; i < sband->n_bitrates; i++) {
 114                 int rate = sband->bitrates[i].bitrate;
 115                 u8 basic = 0;
 116                 if (basic_rates & BIT(i))
 117                         basic = 0x80;
 118                 *pos++ = basic | (u8) (rate / 5);
 119         }
 120
 121         /* Build IBSS probe response */
 122         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 123         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 124         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 125                                           IEEE80211_STYPE_PROBE_RESP);
 126         memset(mgmt->da, 0xff, ETH_ALEN);
 127         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 128         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 129         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 130         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 131         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 132
 133         pos = skb_put(skb, 2 + ifibss->ssid_len);
 134         *pos++ = WLAN_EID_SSID;
 135         *pos++ = ifibss->ssid_len;
 136         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 137
 138         rates = sband->n_bitrates;
 139         if (rates > 8)
 140                 rates = 8;
 141         pos = skb_put(skb, 2 + rates);
 142         *pos++ = WLAN_EID_SUPP_RATES;
 143         *pos++ = rates;
 144         memcpy(pos, supp_rates, rates);
 145
 146         if (sband->band == IEEE80211_BAND_2GHZ) {
 147                 pos = skb_put(skb, 2 + 1);
 148                 *pos++ = WLAN_EID_DS_PARAMS;
 149                 *pos++ = 1;
 150                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 151         }
 152
 153         pos = skb_put(skb, 2 + 2);
 154         *pos++ = WLAN_EID_IBSS_PARAMS;
 155         *pos++ = 2;
 156         /* FIX: set ATIM window based on scan results */
 157         *pos++ = 0;
 158         *pos++ = 0;
 159
 160         if (sband->n_bitrates > 8) {
 161                 rates = sband->n_bitrates - 8;
 162                 pos = skb_put(skb, 2 + rates);
 163                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 164                 *pos++ = rates;
 165                 memcpy(pos, &supp_rates[8], rates);
 166         }
 167
 168         if (ifibss->ie_len)
 169                 memcpy(skb_put(skb, ifibss->ie_len),
 170                        ifibss->ie, ifibss->ie_len);
 171
 172         rcu_assign_pointer(ifibss->presp, skb);
 173
 174         sdata->vif.bss_conf.beacon_int = beacon_int;
 175         sdata->vif.bss_conf.basic_rates = basic_rates;
 176         bss_change = BSS_CHANGED_BEACON_INT;
 177         bss_change |= ieee80211_reset_erp_info(sdata);
 178         bss_change |= BSS_CHANGED_BSSID;
 179         bss_change |= BSS_CHANGED_BEACON;
 180         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 181         bss_change |= BSS_CHANGED_BASIC_RATES;
 182         bss_change |= BSS_CHANGED_IBSS;
 183         sdata->vif.bss_conf.ibss_joined = true;
 184         ieee80211_bss_info_change_notify(sdata, bss_change);
 185
 186         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 187
 188         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 189         mod_timer(&ifibss->timer,
 190                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 191
 192         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 193                                         mgmt, skb->len, 0, GFP_KERNEL);
 194         cfg80211_put_bss(bss);
 195         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 196 }
 197
 198 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 199                                     struct ieee80211_bss *bss)
 200 {
 201         struct cfg80211_bss *cbss =
 202                 container_of((void *)bss, struct cfg80211_bss, priv);
 203         struct ieee80211_supported_band *sband;
 204         u32 basic_rates;
 205         int i, j;
 206         u16 beacon_int = cbss->beacon_interval;
 207
 208         if (beacon_int < 10)
 209                 beacon_int = 10;
 210
 211         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 212
 213         basic_rates = 0;
 214
 215         for (i = 0; i < bss->supp_rates_len; i++) {
 216                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 217                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 218
 219                 for (j = 0; j < sband->n_bitrates; j++) {
 220                         if (sband->bitrates[j].bitrate == rate) {
 221                                 if (is_basic)
 222                                         basic_rates |= BIT(j);
 223                                 break;
 224                         }
 225                 }
 226         }
 227
 228         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 229                                   beacon_int,
 230                                   cbss->channel,
 231                                   basic_rates,
 232                                   cbss->capability,
 233                                   cbss->tsf);
 234 }
 235
 236 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 237                                   struct ieee80211_mgmt *mgmt,
 238                                   size_t len,
 239                                   struct ieee80211_rx_status *rx_status,
 240                                   struct ieee802_11_elems *elems,
 241                                   bool beacon)
 242 {
 243         struct ieee80211_local *local = sdata->local;
 244         int freq;
 245         struct cfg80211_bss *cbss;
 246         struct ieee80211_bss *bss;
 247         struct sta_info *sta;
 248         struct ieee80211_channel *channel;
 249         u64 beacon_timestamp, rx_timestamp;
 250         u32 supp_rates = 0;
 251         enum ieee80211_band band = rx_status->band;
 252
 253         if (elems->ds_params && elems->ds_params_len == 1)
 254                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 255         else
 256                 freq = rx_status->freq;
 257
 258         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 259
 260         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 261                 return;
 262
 263         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 264             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 265                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 266
 267                 rcu_read_lock();
 268
 269                 sta = sta_info_get(sdata, mgmt->sa);
 270                 if (sta) {
 271                         u32 prev_rates;
 272
 273                         prev_rates = sta->sta.supp_rates[band];
 274                         /* make sure mandatory rates are always added */
 275                         sta->sta.supp_rates[band] = supp_rates |
 276                                 ieee80211_mandatory_rates(local, band);
 277
 278                         if (sta->sta.supp_rates[band] != prev_rates) {
 279 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 280                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 281                                     "for %pM based on beacon/probe_response "
 282                                     "(0x%x -> 0x%x)\n",
 283                                     sdata->name, sta->sta.addr,
 284                                     prev_rates, sta->sta.supp_rates[band]);
 285 #endif
 286                                 rate_control_rate_init(sta);
 287                         }
 288                         rcu_read_unlock();
 289                 } else {
 290                         rcu_read_unlock();
 291                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 292                                                supp_rates, GFP_KERNEL);
 293                 }
 294         }
 295
 296         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 297                                         channel, beacon);
 298         if (!bss)
 299                 return;
 300
 301         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 302
 303         /* was just updated in ieee80211_bss_info_update */
 304         beacon_timestamp = cbss->tsf;
 305
 306         /* check if we need to merge IBSS */
 307
 308         /* we use a fixed BSSID */
 309         if (sdata->u.ibss.fixed_bssid)
 310                 goto put_bss;
 311
 312         /* not an IBSS */
 313         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 314                 goto put_bss;
 315
 316         /* different channel */
 317         if (cbss->channel != local->oper_channel)
 318                 goto put_bss;
 319
 320         /* different SSID */
 321         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 322             memcmp(elems->ssid, sdata->u.ibss.ssid,
 323                                 sdata->u.ibss.ssid_len))
 324                 goto put_bss;
 325
 326         /* same BSSID */
 327         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 328                 goto put_bss;
 329
 330         if (rx_status->flag & RX_FLAG_TSFT) {
 331                 /*
 332                  * For correct IBSS merging we need mactime; since mactime is
 333                  * defined as the time the first data symbol of the frame hits
 334                  * the PHY, and the timestamp of the beacon is defined as "the
 335                  * time that the data symbol containing the first bit of the
 336                  * timestamp is transmitted to the PHY plus the transmitting
 337                  * STA's delays through its local PHY from the MAC-PHY
 338                  * interface to its interface with the WM" (802.11 11.1.2)
 339                  * - equals the time this bit arrives at the receiver - we have
 340                  * to take into account the offset between the two.
 341                  *
 342                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 343                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 344                  */
 345                 int rate;
 346
 347                 if (rx_status->flag & RX_FLAG_HT)
 348                         rate = 65; /* TODO: HT rates */
 349                 else
 350                         rate = local->hw.wiphy->bands[band]->
 351                                 bitrates[rx_status->rate_idx].bitrate;
 352
 353                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 354         } else {
 355                 /*
 356                  * second best option: get current TSF
 357                  * (will return -1 if not supported)
 358                  */
 359                 rx_timestamp = drv_get_tsf(local);
 360         }
 361
 362 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 363         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 364                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 365                mgmt->sa, mgmt->bssid,
 366                (unsigned long long)rx_timestamp,
 367                (unsigned long long)beacon_timestamp,
 368                (unsigned long long)(rx_timestamp - beacon_timestamp),
 369                jiffies);
 370 #endif
 371
 372         /* give slow hardware some time to do the TSF sync */
 373         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 374                 goto put_bss;
 375
 376         if (beacon_timestamp > rx_timestamp) {
 377 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 378                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 379                        "local TSF - IBSS merge with BSSID %pM\n",
 380                        sdata->name, mgmt->bssid);
 381 #endif
 382                 ieee80211_sta_join_ibss(sdata, bss);
 383                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 384                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 385                                        supp_rates, GFP_KERNEL);
 386         }
 387
 388  put_bss:
 389         ieee80211_rx_bss_put(local, bss);
 390 }
 391
 392 /*
 393  * Add a new IBSS station, will also be called by the RX code when,
 394  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 395  * must be callable in atomic context.
 396  */
 397 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 398                                         u8 *bssid,u8 *addr, u32 supp_rates,
 399                                         gfp_t gfp)
 400 {
 401         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 402         struct ieee80211_local *local = sdata->local;
 403         struct sta_info *sta;
 404         int band = local->hw.conf.channel->band;
 405
 406         /*
 407          * XXX: Consider removing the least recently used entry and
 408          *      allow new one to be added.
 409          */
 410         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 411                 if (net_ratelimit())
 412                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 413                                sdata->name, addr);
 414                 return NULL;
 415         }
 416
 417         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 418                 return NULL;
 419
 420         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 421                 return NULL;
 422
 423 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 424         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 425                wiphy_name(local->hw.wiphy), addr, sdata->name);
 426 #endif
 427
 428         sta = sta_info_alloc(sdata, addr, gfp);
 429         if (!sta)
 430                 return NULL;
 431
 432         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 433
 434         /* make sure mandatory rates are always added */
 435         sta->sta.supp_rates[band] = supp_rates |
 436                         ieee80211_mandatory_rates(local, band);
 437
 438         rate_control_rate_init(sta);
 439
 440         /* If it fails, maybe we raced another insertion? */
 441         if (sta_info_insert(sta))
 442                 return sta_info_get(sdata, addr);
 443         return sta;
 444 }
 445
 446 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 447 {
 448         struct ieee80211_local *local = sdata->local;
 449         int active = 0;
 450         struct sta_info *sta;
 451
 452         rcu_read_lock();
 453
 454         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 455                 if (sta->sdata == sdata &&
 456                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 457                                jiffies)) {
 458                         active++;
 459                         break;
 460                 }
 461         }
 462
 463         rcu_read_unlock();
 464
 465         return active;
 466 }
 467
 468 /*
 469  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 470  */
 471
 472 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 473 {
 474         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 475
 476         mod_timer(&ifibss->timer,
 477                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 478
 479         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 480
 481         if (time_before(jiffies, ifibss->last_scan_completed +
 482                        IEEE80211_IBSS_MERGE_INTERVAL))
 483                 return;
 484
 485         if (ieee80211_sta_active_ibss(sdata))
 486                 return;
 487
 488         if (ifibss->fixed_channel)
 489                 return;
 490
 491         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 492                "IBSS networks with same SSID (merge)\n", sdata->name);
 493
 494         ieee80211_request_internal_scan(sdata,
 495                         ifibss->ssid, ifibss->ssid_len,
 496                         ifibss->fixed_channel ? ifibss->channel : NULL);
 497 }
 498
 499 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 500 {
 501         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 502         struct ieee80211_local *local = sdata->local;
 503         struct ieee80211_supported_band *sband;
 504         u8 bssid[ETH_ALEN];
 505         u16 capability;
 506         int i;
 507
 508         if (ifibss->fixed_bssid) {
 509                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 510         } else {
 511                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 512                  * own MAC address to make sure that devices that do not have proper
 513                  * random number generator get different BSSID. */
 514                 get_random_bytes(bssid, ETH_ALEN);
 515                 for (i = 0; i < ETH_ALEN; i++)
 516                         bssid[i] ^= sdata->vif.addr[i];
 517                 bssid[0] &= ~0x01;
 518                 bssid[0] |= 0x02;
 519         }
 520
 521         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 522                sdata->name, bssid);
 523
 524         sband = local->hw.wiphy->bands[ifibss->channel->band];
 525
 526         capability = WLAN_CAPABILITY_IBSS;
 527
 528         if (ifibss->privacy)
 529                 capability |= WLAN_CAPABILITY_PRIVACY;
 530         else
 531                 sdata->drop_unencrypted = 0;
 532
 533         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 534                                   ifibss->channel, ifibss->basic_rates,
 535                                   capability, 0);
 536 }
 537
 538 /*
 539  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 540  */
 541
 542 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 543 {
 544         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 545         struct ieee80211_local *local = sdata->local;
 546         struct cfg80211_bss *cbss;
 547         struct ieee80211_channel *chan = NULL;
 548         const u8 *bssid = NULL;
 549         int active_ibss;
 550         u16 capability;
 551
 552         active_ibss = ieee80211_sta_active_ibss(sdata);
 553 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 554         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 555                sdata->name, active_ibss);
 556 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 557
 558         if (active_ibss)
 559                 return;
 560
 561         capability = WLAN_CAPABILITY_IBSS;
 562         if (ifibss->privacy)
 563                 capability |= WLAN_CAPABILITY_PRIVACY;
 564         if (ifibss->fixed_bssid)
 565                 bssid = ifibss->bssid;
 566         if (ifibss->fixed_channel)
 567                 chan = ifibss->channel;
 568         if (!is_zero_ether_addr(ifibss->bssid))
 569                 bssid = ifibss->bssid;
 570         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 571                                 ifibss->ssid, ifibss->ssid_len,
 572                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 573                                 capability);
 574
 575         if (cbss) {
 576                 struct ieee80211_bss *bss;
 577
 578                 bss = (void *)cbss->priv;
 579 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 580                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 581                        "%pM\n", cbss->bssid, ifibss->bssid);
 582 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 583
 584                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 585                        " based on configured SSID\n",
 586                        sdata->name, cbss->bssid);
 587
 588                 ieee80211_sta_join_ibss(sdata, bss);
 589                 ieee80211_rx_bss_put(local, bss);
 590                 return;
 591         }
 592
 593 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 594         printk(KERN_DEBUG "   did not try to join ibss\n");
 595 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 596
 597         /* Selected IBSS not found in current scan results - try to scan */
 598         if (time_after(jiffies, ifibss->last_scan_completed +
 599                                         IEEE80211_SCAN_INTERVAL)) {
 600                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 601                        "join\n", sdata->name);
 602
 603                 ieee80211_request_internal_scan(sdata,
 604                                 ifibss->ssid, ifibss->ssid_len,
 605                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 606         } else {
 607                 int interval = IEEE80211_SCAN_INTERVAL;
 608
 609                 if (time_after(jiffies, ifibss->ibss_join_req +
 610                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 611                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 612                                 ieee80211_sta_create_ibss(sdata);
 613                                 return;
 614                         }
 615                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 616                                " %d MHz\n", sdata->name,
 617                                local->hw.conf.channel->center_freq);
 618
 619                         /* No IBSS found - decrease scan interval and continue
 620                          * scanning. */
 621                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 622                 }
 623
 624                 mod_timer(&ifibss->timer,
 625                           round_jiffies(jiffies + interval));
 626         }
 627 }
 628
 629 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 630                                         struct ieee80211_mgmt *mgmt,
 631                                         size_t len)
 632 {
 633         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 634         struct ieee80211_local *local = sdata->local;
 635         int tx_last_beacon;
 636         struct sk_buff *skb;
 637         struct ieee80211_mgmt *resp;
 638         u8 *pos, *end;
 639
 640         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 641             len < 24 + 2 || !ifibss->presp)
 642                 return;
 643
 644         tx_last_beacon = drv_tx_last_beacon(local);
 645
 646 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 647         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 648                " (tx_last_beacon=%d)\n",
 649                sdata->name, mgmt->sa, mgmt->da,
 650                mgmt->bssid, tx_last_beacon);
 651 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 652
 653         if (!tx_last_beacon)
 654                 return;
 655
 656         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 657             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 658                 return;
 659
 660         end = ((u8 *) mgmt) + len;
 661         pos = mgmt->u.probe_req.variable;
 662         if (pos[0] != WLAN_EID_SSID ||
 663             pos + 2 + pos[1] > end) {
 664 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 665                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 666                        "from %pM\n",
 667                        sdata->name, mgmt->sa);
 668 #endif
 669                 return;
 670         }
 671         if (pos[1] != 0 &&
 672             (pos[1] != ifibss->ssid_len ||
 673              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 674                 /* Ignore ProbeReq for foreign SSID */
 675                 return;
 676         }
 677
 678         /* Reply with ProbeResp */
 679         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 680         if (!skb)
 681                 return;
 682
 683         resp = (struct ieee80211_mgmt *) skb->data;
 684         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 685 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 686         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 687                sdata->name, resp->da);
 688 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 689         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 690         ieee80211_tx_skb(sdata, skb);
 691 }
 692
 693 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 694                                          struct ieee80211_mgmt *mgmt,
 695                                          size_t len,
 696                                          struct ieee80211_rx_status *rx_status)
 697 {
 698         size_t baselen;
 699         struct ieee802_11_elems elems;
 700
 701         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 702                 return; /* ignore ProbeResp to foreign address */
 703
 704         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 705         if (baselen > len)
 706                 return;
 707
 708         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 709                                 &elems);
 710
 711         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 712 }
 713
 714 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 715                                      struct ieee80211_mgmt *mgmt,
 716                                      size_t len,
 717                                      struct ieee80211_rx_status *rx_status)
 718 {
 719         size_t baselen;
 720         struct ieee802_11_elems elems;
 721
 722         /* Process beacon from the current BSS */
 723         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 724         if (baselen > len)
 725                 return;
 726
 727         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 728
 729         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 730 }
 731
 732 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 733                                    struct sk_buff *skb)
 734 {
 735         struct ieee80211_rx_status *rx_status;
 736         struct ieee80211_mgmt *mgmt;
 737         u16 fc;
 738
 739         rx_status = IEEE80211_SKB_RXCB(skb);
 740         mgmt = (struct ieee80211_mgmt *) skb->data;
 741         fc = le16_to_cpu(mgmt->frame_control);
 742
 743         switch (fc & IEEE80211_FCTL_STYPE) {
 744         case IEEE80211_STYPE_PROBE_REQ:
 745                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 746                 break;
 747         case IEEE80211_STYPE_PROBE_RESP:
 748                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 749                                              rx_status);
 750                 break;
 751         case IEEE80211_STYPE_BEACON:
 752                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 753                                          rx_status);
 754                 break;
 755         case IEEE80211_STYPE_AUTH:
 756                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 757                 break;
 758         }
 759 }
 760
 761 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 762 {
 763         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 764
 765         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 766                 return;
 767
 768         switch (ifibss->state) {
 769         case IEEE80211_IBSS_MLME_SEARCH:
 770                 ieee80211_sta_find_ibss(sdata);
 771                 break;
 772         case IEEE80211_IBSS_MLME_JOINED:
 773                 ieee80211_sta_merge_ibss(sdata);
 774                 break;
 775         default:
 776                 WARN_ON(1);
 777                 break;
 778         }
 779 }
 780
 781 static void ieee80211_queue_ibss_work(struct ieee80211_sub_if_data *sdata)
 782 {
 783         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 784         struct ieee80211_local *local = sdata->local;
 785
 786         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 787         ieee80211_queue_work(&local->hw, &sdata->work);
 788 }
 789
 790 static void ieee80211_ibss_timer(unsigned long data)
 791 {
 792         struct ieee80211_sub_if_data *sdata =
 793                 (struct ieee80211_sub_if_data *) data;
 794         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 795         struct ieee80211_local *local = sdata->local;
 796
 797         if (local->quiescing) {
 798                 ifibss->timer_running = true;
 799                 return;
 800         }
 801
 802         ieee80211_queue_ibss_work(sdata);
 803 }
 804
 805 #ifdef CONFIG_PM
 806 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 807 {
 808         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 809
 810         if (del_timer_sync(&ifibss->timer))
 811                 ifibss->timer_running = true;
 812 }
 813
 814 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 815 {
 816         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 817
 818         if (ifibss->timer_running) {
 819                 add_timer(&ifibss->timer);
 820                 ifibss->timer_running = false;
 821         }
 822 }
 823 #endif
 824
 825 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 826 {
 827         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 828
 829         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 830                     (unsigned long) sdata);
 831 }
 832
 833 /* scan finished notification */
 834 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 835 {
 836         struct ieee80211_sub_if_data *sdata;
 837
 838         mutex_lock(&local->iflist_mtx);
 839         list_for_each_entry(sdata, &local->interfaces, list) {
 840                 if (!ieee80211_sdata_running(sdata))
 841                         continue;
 842                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 843                         continue;
 844                 if (!sdata->u.ibss.ssid_len)
 845                         continue;
 846                 sdata->u.ibss.last_scan_completed = jiffies;
 847                 ieee80211_queue_ibss_work(sdata);
 848         }
 849         mutex_unlock(&local->iflist_mtx);
 850 }
 851
 852 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 853                         struct cfg80211_ibss_params *params)
 854 {
 855         struct sk_buff *skb;
 856
 857         if (params->bssid) {
 858                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 859                 sdata->u.ibss.fixed_bssid = true;
 860         } else
 861                 sdata->u.ibss.fixed_bssid = false;
 862
 863         sdata->u.ibss.privacy = params->privacy;
 864         sdata->u.ibss.basic_rates = params->basic_rates;
 865
 866         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 867
 868         sdata->u.ibss.channel = params->channel;
 869         sdata->u.ibss.fixed_channel = params->channel_fixed;
 870
 871         /* fix ourselves to that channel now already */
 872         if (params->channel_fixed) {
 873                 sdata->local->oper_channel = params->channel;
 874                 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
 875                                                     NL80211_CHAN_NO_HT));
 876         }
 877
 878         if (params->ie) {
 879                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 880                                            GFP_KERNEL);
 881                 if (sdata->u.ibss.ie)
 882                         sdata->u.ibss.ie_len = params->ie_len;
 883         }
 884
 885         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 886                             36 /* bitrates */ +
 887                             34 /* SSID */ +
 888                             3  /* DS params */ +
 889                             4  /* IBSS params */ +
 890                             params->ie_len);
 891         if (!skb)
 892                 return -ENOMEM;
 893
 894         sdata->u.ibss.skb = skb;
 895         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 896         sdata->u.ibss.ibss_join_req = jiffies;
 897
 898         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 899
 900         /*
 901          * The ssid_len setting below is used to see whether
 902          * we are active, and we need all other settings
 903          * before that may get visible.
 904          */
 905         mb();
 906
 907         sdata->u.ibss.ssid_len = params->ssid_len;
 908
 909         ieee80211_recalc_idle(sdata->local);
 910
 911         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 912         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 913
 914         return 0;
 915 }
 916
 917 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 918 {
 919         struct sk_buff *skb;
 920         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 921         struct ieee80211_local *local = sdata->local;
 922         struct cfg80211_bss *cbss;
 923         u16 capability;
 924         int active_ibss = 0;
 925
 926         active_ibss = ieee80211_sta_active_ibss(sdata);
 927
 928         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
 929                 capability = WLAN_CAPABILITY_IBSS;
 930
 931                 if (ifibss->privacy)
 932                         capability |= WLAN_CAPABILITY_PRIVACY;
 933
 934                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
 935                                         ifibss->bssid, ifibss->ssid,
 936                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 937                                         WLAN_CAPABILITY_PRIVACY,
 938                                         capability);
 939
 940                 if (cbss) {
 941                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
 942                         cfg80211_put_bss(cbss);
 943                 }
 944         }
 945
 946         del_timer_sync(&sdata->u.ibss.timer);
 947         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 948         cancel_work_sync(&sdata->work);
 949         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 950
 951         sta_info_flush(sdata->local, sdata);
 952
 953         /* remove beacon */
 954         kfree(sdata->u.ibss.ie);
 955         skb = sdata->u.ibss.presp;
 956         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 957         sdata->vif.bss_conf.ibss_joined = false;
 958         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 959                                                 BSS_CHANGED_IBSS);
 960         synchronize_rcu();
 961         kfree_skb(skb);
 962
 963         skb_queue_purge(&sdata->skb_queue);
 964         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 965         sdata->u.ibss.ssid_len = 0;
 966
 967         ieee80211_recalc_idle(sdata->local);
 968
 969         return 0;
 970 }