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         lockdep_assert_held(&sdata->u.ibss.mtx);
  47
  48         if (len < 24 + 6)
  49                 return;
  50
  51         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  52         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  53         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  54
  55         /*
  56          * IEEE 802.11 standard does not require authentication in IBSS
  57          * networks and most implementations do not seem to use it.
  58          * However, try to reply to authentication attempts if someone
  59          * has actually implemented this.
  60          */
  61         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  62                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  63                                     sdata->u.ibss.bssid, NULL, 0, 0);
  64 }
  65
  66 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  67                                       const u8 *bssid, const int beacon_int,
  68                                       struct ieee80211_channel *chan,
  69                                       const u32 basic_rates,
  70                                       const u16 capability, u64 tsf)
  71 {
  72         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  73         struct ieee80211_local *local = sdata->local;
  74         int rates, i;
  75         struct sk_buff *skb;
  76         struct ieee80211_mgmt *mgmt;
  77         u8 *pos;
  78         struct ieee80211_supported_band *sband;
  79         struct cfg80211_bss *bss;
  80         u32 bss_change;
  81         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  82
  83         lockdep_assert_held(&ifibss->mtx);
  84
  85         /* Reset own TSF to allow time synchronization work. */
  86         drv_reset_tsf(local);
  87
  88         skb = ifibss->skb;
  89         rcu_assign_pointer(ifibss->presp, NULL);
  90         synchronize_rcu();
  91         skb->data = skb->head;
  92         skb->len = 0;
  93         skb_reset_tail_pointer(skb);
  94         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  95
  96         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  97                 sta_info_flush(sdata->local, sdata);
  98
  99         /* if merging, indicate to driver that we leave the old IBSS */
 100         if (sdata->vif.bss_conf.ibss_joined) {
 101                 sdata->vif.bss_conf.ibss_joined = false;
 102                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
 103         }
 104
 105         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 106
 107         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 108
 109         local->oper_channel = chan;
 110         WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
 111         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 112
 113         sband = local->hw.wiphy->bands[chan->band];
 114
 115         /* build supported rates array */
 116         pos = supp_rates;
 117         for (i = 0; i < sband->n_bitrates; i++) {
 118                 int rate = sband->bitrates[i].bitrate;
 119                 u8 basic = 0;
 120                 if (basic_rates & BIT(i))
 121                         basic = 0x80;
 122                 *pos++ = basic | (u8) (rate / 5);
 123         }
 124
 125         /* Build IBSS probe response */
 126         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 127         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 128         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 129                                           IEEE80211_STYPE_PROBE_RESP);
 130         memset(mgmt->da, 0xff, ETH_ALEN);
 131         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 132         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 133         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 134         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 135         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 136
 137         pos = skb_put(skb, 2 + ifibss->ssid_len);
 138         *pos++ = WLAN_EID_SSID;
 139         *pos++ = ifibss->ssid_len;
 140         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 141
 142         rates = sband->n_bitrates;
 143         if (rates > 8)
 144                 rates = 8;
 145         pos = skb_put(skb, 2 + rates);
 146         *pos++ = WLAN_EID_SUPP_RATES;
 147         *pos++ = rates;
 148         memcpy(pos, supp_rates, rates);
 149
 150         if (sband->band == IEEE80211_BAND_2GHZ) {
 151                 pos = skb_put(skb, 2 + 1);
 152                 *pos++ = WLAN_EID_DS_PARAMS;
 153                 *pos++ = 1;
 154                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 155         }
 156
 157         pos = skb_put(skb, 2 + 2);
 158         *pos++ = WLAN_EID_IBSS_PARAMS;
 159         *pos++ = 2;
 160         /* FIX: set ATIM window based on scan results */
 161         *pos++ = 0;
 162         *pos++ = 0;
 163
 164         if (sband->n_bitrates > 8) {
 165                 rates = sband->n_bitrates - 8;
 166                 pos = skb_put(skb, 2 + rates);
 167                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 168                 *pos++ = rates;
 169                 memcpy(pos, &supp_rates[8], rates);
 170         }
 171
 172         if (ifibss->ie_len)
 173                 memcpy(skb_put(skb, ifibss->ie_len),
 174                        ifibss->ie, ifibss->ie_len);
 175
 176         rcu_assign_pointer(ifibss->presp, skb);
 177
 178         sdata->vif.bss_conf.beacon_int = beacon_int;
 179         sdata->vif.bss_conf.basic_rates = basic_rates;
 180         bss_change = BSS_CHANGED_BEACON_INT;
 181         bss_change |= ieee80211_reset_erp_info(sdata);
 182         bss_change |= BSS_CHANGED_BSSID;
 183         bss_change |= BSS_CHANGED_BEACON;
 184         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 185         bss_change |= BSS_CHANGED_BASIC_RATES;
 186         bss_change |= BSS_CHANGED_IBSS;
 187         sdata->vif.bss_conf.ibss_joined = true;
 188         ieee80211_bss_info_change_notify(sdata, bss_change);
 189
 190         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 191
 192         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 193         mod_timer(&ifibss->timer,
 194                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 195
 196         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 197                                         mgmt, skb->len, 0, GFP_KERNEL);
 198         cfg80211_put_bss(bss);
 199         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 200 }
 201
 202 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 203                                     struct ieee80211_bss *bss)
 204 {
 205         struct cfg80211_bss *cbss =
 206                 container_of((void *)bss, struct cfg80211_bss, priv);
 207         struct ieee80211_supported_band *sband;
 208         u32 basic_rates;
 209         int i, j;
 210         u16 beacon_int = cbss->beacon_interval;
 211
 212         lockdep_assert_held(&sdata->u.ibss.mtx);
 213
 214         if (beacon_int < 10)
 215                 beacon_int = 10;
 216
 217         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 218
 219         basic_rates = 0;
 220
 221         for (i = 0; i < bss->supp_rates_len; i++) {
 222                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 223                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 224
 225                 for (j = 0; j < sband->n_bitrates; j++) {
 226                         if (sband->bitrates[j].bitrate == rate) {
 227                                 if (is_basic)
 228                                         basic_rates |= BIT(j);
 229                                 break;
 230                         }
 231                 }
 232         }
 233
 234         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 235                                   beacon_int,
 236                                   cbss->channel,
 237                                   basic_rates,
 238                                   cbss->capability,
 239                                   cbss->tsf);
 240 }
 241
 242 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 243                                   struct ieee80211_mgmt *mgmt,
 244                                   size_t len,
 245                                   struct ieee80211_rx_status *rx_status,
 246                                   struct ieee802_11_elems *elems,
 247                                   bool beacon)
 248 {
 249         struct ieee80211_local *local = sdata->local;
 250         int freq;
 251         struct cfg80211_bss *cbss;
 252         struct ieee80211_bss *bss;
 253         struct sta_info *sta;
 254         struct ieee80211_channel *channel;
 255         u64 beacon_timestamp, rx_timestamp;
 256         u32 supp_rates = 0;
 257         enum ieee80211_band band = rx_status->band;
 258
 259         if (elems->ds_params && elems->ds_params_len == 1)
 260                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 261         else
 262                 freq = rx_status->freq;
 263
 264         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 265
 266         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 267                 return;
 268
 269         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 270             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 271                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 272
 273                 rcu_read_lock();
 274
 275                 sta = sta_info_get(sdata, mgmt->sa);
 276                 if (sta) {
 277                         u32 prev_rates;
 278
 279                         prev_rates = sta->sta.supp_rates[band];
 280                         /* make sure mandatory rates are always added */
 281                         sta->sta.supp_rates[band] = supp_rates |
 282                                 ieee80211_mandatory_rates(local, band);
 283
 284                         if (sta->sta.supp_rates[band] != prev_rates) {
 285 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 286                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 287                                     "for %pM based on beacon/probe_response "
 288                                     "(0x%x -> 0x%x)\n",
 289                                     sdata->name, sta->sta.addr,
 290                                     prev_rates, sta->sta.supp_rates[band]);
 291 #endif
 292                                 rate_control_rate_init(sta);
 293                         }
 294                         rcu_read_unlock();
 295                 } else {
 296                         rcu_read_unlock();
 297                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 298                                                supp_rates, GFP_KERNEL);
 299                 }
 300         }
 301
 302         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 303                                         channel, beacon);
 304         if (!bss)
 305                 return;
 306
 307         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 308
 309         /* was just updated in ieee80211_bss_info_update */
 310         beacon_timestamp = cbss->tsf;
 311
 312         /* check if we need to merge IBSS */
 313
 314         /* we use a fixed BSSID */
 315         if (sdata->u.ibss.fixed_bssid)
 316                 goto put_bss;
 317
 318         /* not an IBSS */
 319         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 320                 goto put_bss;
 321
 322         /* different channel */
 323         if (cbss->channel != local->oper_channel)
 324                 goto put_bss;
 325
 326         /* different SSID */
 327         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 328             memcmp(elems->ssid, sdata->u.ibss.ssid,
 329                                 sdata->u.ibss.ssid_len))
 330                 goto put_bss;
 331
 332         /* same BSSID */
 333         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 334                 goto put_bss;
 335
 336         if (rx_status->flag & RX_FLAG_TSFT) {
 337                 /*
 338                  * For correct IBSS merging we need mactime; since mactime is
 339                  * defined as the time the first data symbol of the frame hits
 340                  * the PHY, and the timestamp of the beacon is defined as "the
 341                  * time that the data symbol containing the first bit of the
 342                  * timestamp is transmitted to the PHY plus the transmitting
 343                  * STA's delays through its local PHY from the MAC-PHY
 344                  * interface to its interface with the WM" (802.11 11.1.2)
 345                  * - equals the time this bit arrives at the receiver - we have
 346                  * to take into account the offset between the two.
 347                  *
 348                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 349                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 350                  */
 351                 int rate;
 352
 353                 if (rx_status->flag & RX_FLAG_HT)
 354                         rate = 65; /* TODO: HT rates */
 355                 else
 356                         rate = local->hw.wiphy->bands[band]->
 357                                 bitrates[rx_status->rate_idx].bitrate;
 358
 359                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 360         } else {
 361                 /*
 362                  * second best option: get current TSF
 363                  * (will return -1 if not supported)
 364                  */
 365                 rx_timestamp = drv_get_tsf(local);
 366         }
 367
 368 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 369         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 370                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 371                mgmt->sa, mgmt->bssid,
 372                (unsigned long long)rx_timestamp,
 373                (unsigned long long)beacon_timestamp,
 374                (unsigned long long)(rx_timestamp - beacon_timestamp),
 375                jiffies);
 376 #endif
 377
 378         /* give slow hardware some time to do the TSF sync */
 379         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 380                 goto put_bss;
 381
 382         if (beacon_timestamp > rx_timestamp) {
 383 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 384                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 385                        "local TSF - IBSS merge with BSSID %pM\n",
 386                        sdata->name, mgmt->bssid);
 387 #endif
 388                 ieee80211_sta_join_ibss(sdata, bss);
 389                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 390                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 391                                        supp_rates, GFP_KERNEL);
 392         }
 393
 394  put_bss:
 395         ieee80211_rx_bss_put(local, bss);
 396 }
 397
 398 /*
 399  * Add a new IBSS station, will also be called by the RX code when,
 400  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 401  * must be callable in atomic context.
 402  */
 403 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 404                                         u8 *bssid,u8 *addr, u32 supp_rates,
 405                                         gfp_t gfp)
 406 {
 407         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 408         struct ieee80211_local *local = sdata->local;
 409         struct sta_info *sta;
 410         int band = local->hw.conf.channel->band;
 411
 412         /*
 413          * XXX: Consider removing the least recently used entry and
 414          *      allow new one to be added.
 415          */
 416         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 417                 if (net_ratelimit())
 418                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 419                                sdata->name, addr);
 420                 return NULL;
 421         }
 422
 423         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 424                 return NULL;
 425
 426         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 427                 return NULL;
 428
 429 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 430         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 431                wiphy_name(local->hw.wiphy), addr, sdata->name);
 432 #endif
 433
 434         sta = sta_info_alloc(sdata, addr, gfp);
 435         if (!sta)
 436                 return NULL;
 437
 438         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 439
 440         /* make sure mandatory rates are always added */
 441         sta->sta.supp_rates[band] = supp_rates |
 442                         ieee80211_mandatory_rates(local, band);
 443
 444         rate_control_rate_init(sta);
 445
 446         /* If it fails, maybe we raced another insertion? */
 447         if (sta_info_insert(sta))
 448                 return sta_info_get(sdata, addr);
 449         return sta;
 450 }
 451
 452 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 453 {
 454         struct ieee80211_local *local = sdata->local;
 455         int active = 0;
 456         struct sta_info *sta;
 457
 458         lockdep_assert_held(&sdata->u.ibss.mtx);
 459
 460         rcu_read_lock();
 461
 462         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 463                 if (sta->sdata == sdata &&
 464                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 465                                jiffies)) {
 466                         active++;
 467                         break;
 468                 }
 469         }
 470
 471         rcu_read_unlock();
 472
 473         return active;
 474 }
 475
 476 /*
 477  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 478  */
 479
 480 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 481 {
 482         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 483
 484         lockdep_assert_held(&ifibss->mtx);
 485
 486         mod_timer(&ifibss->timer,
 487                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 488
 489         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 490
 491         if (time_before(jiffies, ifibss->last_scan_completed +
 492                        IEEE80211_IBSS_MERGE_INTERVAL))
 493                 return;
 494
 495         if (ieee80211_sta_active_ibss(sdata))
 496                 return;
 497
 498         if (ifibss->fixed_channel)
 499                 return;
 500
 501         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 502                "IBSS networks with same SSID (merge)\n", sdata->name);
 503
 504         ieee80211_request_internal_scan(sdata,
 505                         ifibss->ssid, ifibss->ssid_len,
 506                         ifibss->fixed_channel ? ifibss->channel : NULL);
 507 }
 508
 509 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 510 {
 511         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 512         struct ieee80211_local *local = sdata->local;
 513         struct ieee80211_supported_band *sband;
 514         u8 bssid[ETH_ALEN];
 515         u16 capability;
 516         int i;
 517
 518         lockdep_assert_held(&ifibss->mtx);
 519
 520         if (ifibss->fixed_bssid) {
 521                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 522         } else {
 523                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 524                  * own MAC address to make sure that devices that do not have proper
 525                  * random number generator get different BSSID. */
 526                 get_random_bytes(bssid, ETH_ALEN);
 527                 for (i = 0; i < ETH_ALEN; i++)
 528                         bssid[i] ^= sdata->vif.addr[i];
 529                 bssid[0] &= ~0x01;
 530                 bssid[0] |= 0x02;
 531         }
 532
 533         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 534                sdata->name, bssid);
 535
 536         sband = local->hw.wiphy->bands[ifibss->channel->band];
 537
 538         capability = WLAN_CAPABILITY_IBSS;
 539
 540         if (ifibss->privacy)
 541                 capability |= WLAN_CAPABILITY_PRIVACY;
 542         else
 543                 sdata->drop_unencrypted = 0;
 544
 545         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 546                                   ifibss->channel, ifibss->basic_rates,
 547                                   capability, 0);
 548 }
 549
 550 /*
 551  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 552  */
 553
 554 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 555 {
 556         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 557         struct ieee80211_local *local = sdata->local;
 558         struct cfg80211_bss *cbss;
 559         struct ieee80211_channel *chan = NULL;
 560         const u8 *bssid = NULL;
 561         int active_ibss;
 562         u16 capability;
 563
 564         lockdep_assert_held(&ifibss->mtx);
 565
 566         active_ibss = ieee80211_sta_active_ibss(sdata);
 567 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 568         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 569                sdata->name, active_ibss);
 570 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 571
 572         if (active_ibss)
 573                 return;
 574
 575         capability = WLAN_CAPABILITY_IBSS;
 576         if (ifibss->privacy)
 577                 capability |= WLAN_CAPABILITY_PRIVACY;
 578         if (ifibss->fixed_bssid)
 579                 bssid = ifibss->bssid;
 580         if (ifibss->fixed_channel)
 581                 chan = ifibss->channel;
 582         if (!is_zero_ether_addr(ifibss->bssid))
 583                 bssid = ifibss->bssid;
 584         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 585                                 ifibss->ssid, ifibss->ssid_len,
 586                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 587                                 capability);
 588
 589         if (cbss) {
 590                 struct ieee80211_bss *bss;
 591
 592                 bss = (void *)cbss->priv;
 593 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 594                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 595                        "%pM\n", cbss->bssid, ifibss->bssid);
 596 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 597
 598                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 599                        " based on configured SSID\n",
 600                        sdata->name, cbss->bssid);
 601
 602                 ieee80211_sta_join_ibss(sdata, bss);
 603                 ieee80211_rx_bss_put(local, bss);
 604                 return;
 605         }
 606
 607 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 608         printk(KERN_DEBUG "   did not try to join ibss\n");
 609 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 610
 611         /* Selected IBSS not found in current scan results - try to scan */
 612         if (time_after(jiffies, ifibss->last_scan_completed +
 613                                         IEEE80211_SCAN_INTERVAL)) {
 614                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 615                        "join\n", sdata->name);
 616
 617                 ieee80211_request_internal_scan(sdata,
 618                                 ifibss->ssid, ifibss->ssid_len,
 619                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 620         } else {
 621                 int interval = IEEE80211_SCAN_INTERVAL;
 622
 623                 if (time_after(jiffies, ifibss->ibss_join_req +
 624                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 625                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 626                                 ieee80211_sta_create_ibss(sdata);
 627                                 return;
 628                         }
 629                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 630                                " %d MHz\n", sdata->name,
 631                                local->hw.conf.channel->center_freq);
 632
 633                         /* No IBSS found - decrease scan interval and continue
 634                          * scanning. */
 635                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 636                 }
 637
 638                 mod_timer(&ifibss->timer,
 639                           round_jiffies(jiffies + interval));
 640         }
 641 }
 642
 643 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 644                                         struct ieee80211_mgmt *mgmt,
 645                                         size_t len)
 646 {
 647         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 648         struct ieee80211_local *local = sdata->local;
 649         int tx_last_beacon;
 650         struct sk_buff *skb;
 651         struct ieee80211_mgmt *resp;
 652         u8 *pos, *end;
 653
 654         lockdep_assert_held(&ifibss->mtx);
 655
 656         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 657             len < 24 + 2 || !ifibss->presp)
 658                 return;
 659
 660         tx_last_beacon = drv_tx_last_beacon(local);
 661
 662 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 663         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 664                " (tx_last_beacon=%d)\n",
 665                sdata->name, mgmt->sa, mgmt->da,
 666                mgmt->bssid, tx_last_beacon);
 667 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 668
 669         if (!tx_last_beacon)
 670                 return;
 671
 672         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 673             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 674                 return;
 675
 676         end = ((u8 *) mgmt) + len;
 677         pos = mgmt->u.probe_req.variable;
 678         if (pos[0] != WLAN_EID_SSID ||
 679             pos + 2 + pos[1] > end) {
 680 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 681                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 682                        "from %pM\n",
 683                        sdata->name, mgmt->sa);
 684 #endif
 685                 return;
 686         }
 687         if (pos[1] != 0 &&
 688             (pos[1] != ifibss->ssid_len ||
 689              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 690                 /* Ignore ProbeReq for foreign SSID */
 691                 return;
 692         }
 693
 694         /* Reply with ProbeResp */
 695         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 696         if (!skb)
 697                 return;
 698
 699         resp = (struct ieee80211_mgmt *) skb->data;
 700         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 701 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 702         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 703                sdata->name, resp->da);
 704 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 705         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 706         ieee80211_tx_skb(sdata, skb);
 707 }
 708
 709 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 710                                          struct ieee80211_mgmt *mgmt,
 711                                          size_t len,
 712                                          struct ieee80211_rx_status *rx_status)
 713 {
 714         size_t baselen;
 715         struct ieee802_11_elems elems;
 716
 717         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 718                 return; /* ignore ProbeResp to foreign address */
 719
 720         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 721         if (baselen > len)
 722                 return;
 723
 724         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 725                                 &elems);
 726
 727         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 728 }
 729
 730 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 731                                      struct ieee80211_mgmt *mgmt,
 732                                      size_t len,
 733                                      struct ieee80211_rx_status *rx_status)
 734 {
 735         size_t baselen;
 736         struct ieee802_11_elems elems;
 737
 738         /* Process beacon from the current BSS */
 739         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 740         if (baselen > len)
 741                 return;
 742
 743         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 744
 745         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 746 }
 747
 748 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 749                                    struct sk_buff *skb)
 750 {
 751         struct ieee80211_rx_status *rx_status;
 752         struct ieee80211_mgmt *mgmt;
 753         u16 fc;
 754
 755         rx_status = IEEE80211_SKB_RXCB(skb);
 756         mgmt = (struct ieee80211_mgmt *) skb->data;
 757         fc = le16_to_cpu(mgmt->frame_control);
 758
 759         mutex_lock(&sdata->u.ibss.mtx);
 760
 761         switch (fc & IEEE80211_FCTL_STYPE) {
 762         case IEEE80211_STYPE_PROBE_REQ:
 763                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 764                 break;
 765         case IEEE80211_STYPE_PROBE_RESP:
 766                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 767                                              rx_status);
 768                 break;
 769         case IEEE80211_STYPE_BEACON:
 770                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 771                                          rx_status);
 772                 break;
 773         case IEEE80211_STYPE_AUTH:
 774                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 775                 break;
 776         }
 777
 778         mutex_unlock(&sdata->u.ibss.mtx);
 779 }
 780
 781 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 782 {
 783         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 784
 785         mutex_lock(&ifibss->mtx);
 786
 787         /*
 788          * Work could be scheduled after scan or similar
 789          * when we aren't even joined (or trying) with a
 790          * network.
 791          */
 792         if (!ifibss->ssid_len)
 793                 goto out;
 794
 795         switch (ifibss->state) {
 796         case IEEE80211_IBSS_MLME_SEARCH:
 797                 ieee80211_sta_find_ibss(sdata);
 798                 break;
 799         case IEEE80211_IBSS_MLME_JOINED:
 800                 ieee80211_sta_merge_ibss(sdata);
 801                 break;
 802         default:
 803                 WARN_ON(1);
 804                 break;
 805         }
 806
 807  out:
 808         mutex_unlock(&ifibss->mtx);
 809 }
 810
 811 static void ieee80211_ibss_timer(unsigned long data)
 812 {
 813         struct ieee80211_sub_if_data *sdata =
 814                 (struct ieee80211_sub_if_data *) data;
 815         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 816         struct ieee80211_local *local = sdata->local;
 817
 818         if (local->quiescing) {
 819                 ifibss->timer_running = true;
 820                 return;
 821         }
 822
 823         ieee80211_queue_work(&local->hw, &sdata->work);
 824 }
 825
 826 #ifdef CONFIG_PM
 827 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 828 {
 829         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 830
 831         if (del_timer_sync(&ifibss->timer))
 832                 ifibss->timer_running = true;
 833 }
 834
 835 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 836 {
 837         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 838
 839         if (ifibss->timer_running) {
 840                 add_timer(&ifibss->timer);
 841                 ifibss->timer_running = false;
 842         }
 843 }
 844 #endif
 845
 846 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 847 {
 848         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 849
 850         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 851                     (unsigned long) sdata);
 852         mutex_init(&ifibss->mtx);
 853 }
 854
 855 /* scan finished notification */
 856 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 857 {
 858         struct ieee80211_sub_if_data *sdata;
 859
 860         mutex_lock(&local->iflist_mtx);
 861         list_for_each_entry(sdata, &local->interfaces, list) {
 862                 if (!ieee80211_sdata_running(sdata))
 863                         continue;
 864                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 865                         continue;
 866                 sdata->u.ibss.last_scan_completed = jiffies;
 867                 ieee80211_queue_work(&local->hw, &sdata->work);
 868         }
 869         mutex_unlock(&local->iflist_mtx);
 870 }
 871
 872 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 873                         struct cfg80211_ibss_params *params)
 874 {
 875         struct sk_buff *skb;
 876
 877         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 878                             36 /* bitrates */ +
 879                             34 /* SSID */ +
 880                             3  /* DS params */ +
 881                             4  /* IBSS params */ +
 882                             params->ie_len);
 883         if (!skb)
 884                 return -ENOMEM;
 885
 886         mutex_lock(&sdata->u.ibss.mtx);
 887
 888         if (params->bssid) {
 889                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 890                 sdata->u.ibss.fixed_bssid = true;
 891         } else
 892                 sdata->u.ibss.fixed_bssid = false;
 893
 894         sdata->u.ibss.privacy = params->privacy;
 895         sdata->u.ibss.basic_rates = params->basic_rates;
 896
 897         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 898
 899         sdata->u.ibss.channel = params->channel;
 900         sdata->u.ibss.fixed_channel = params->channel_fixed;
 901
 902         /* fix ourselves to that channel now already */
 903         if (params->channel_fixed) {
 904                 sdata->local->oper_channel = params->channel;
 905                 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
 906                                                     NL80211_CHAN_NO_HT));
 907         }
 908
 909         if (params->ie) {
 910                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 911                                            GFP_KERNEL);
 912                 if (sdata->u.ibss.ie)
 913                         sdata->u.ibss.ie_len = params->ie_len;
 914         }
 915
 916         sdata->u.ibss.skb = skb;
 917         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 918         sdata->u.ibss.ibss_join_req = jiffies;
 919
 920         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 921         sdata->u.ibss.ssid_len = params->ssid_len;
 922
 923         ieee80211_recalc_idle(sdata->local);
 924
 925         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 926
 927         mutex_unlock(&sdata->u.ibss.mtx);
 928
 929         return 0;
 930 }
 931
 932 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 933 {
 934         struct sk_buff *skb;
 935         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 936         struct ieee80211_local *local = sdata->local;
 937         struct cfg80211_bss *cbss;
 938         u16 capability;
 939         int active_ibss;
 940
 941         mutex_lock(&sdata->u.ibss.mtx);
 942
 943         active_ibss = ieee80211_sta_active_ibss(sdata);
 944
 945         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
 946                 capability = WLAN_CAPABILITY_IBSS;
 947
 948                 if (ifibss->privacy)
 949                         capability |= WLAN_CAPABILITY_PRIVACY;
 950
 951                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
 952                                         ifibss->bssid, ifibss->ssid,
 953                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 954                                         WLAN_CAPABILITY_PRIVACY,
 955                                         capability);
 956
 957                 if (cbss) {
 958                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
 959                         cfg80211_put_bss(cbss);
 960                 }
 961         }
 962
 963         sta_info_flush(sdata->local, sdata);
 964
 965         /* remove beacon */
 966         kfree(sdata->u.ibss.ie);
 967         skb = sdata->u.ibss.presp;
 968         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 969         sdata->vif.bss_conf.ibss_joined = false;
 970         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 971                                                 BSS_CHANGED_IBSS);
 972         synchronize_rcu();
 973         kfree_skb(skb);
 974
 975         skb_queue_purge(&sdata->skb_queue);
 976         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 977         sdata->u.ibss.ssid_len = 0;
 978
 979         del_timer_sync(&sdata->u.ibss.timer);
 980
 981         mutex_unlock(&sdata->u.ibss.mtx);
 982
 983         ieee80211_recalc_idle(sdata->local);
 984
 985         return 0;
 986 }