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         sta->last_rx = jiffies;
 439         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 440
 441         /* make sure mandatory rates are always added */
 442         sta->sta.supp_rates[band] = supp_rates |
 443                         ieee80211_mandatory_rates(local, band);
 444
 445         rate_control_rate_init(sta);
 446
 447         /* If it fails, maybe we raced another insertion? */
 448         if (sta_info_insert(sta))
 449                 return sta_info_get(sdata, addr);
 450         return sta;
 451 }
 452
 453 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 454 {
 455         struct ieee80211_local *local = sdata->local;
 456         int active = 0;
 457         struct sta_info *sta;
 458
 459         lockdep_assert_held(&sdata->u.ibss.mtx);
 460
 461         rcu_read_lock();
 462
 463         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 464                 if (sta->sdata == sdata &&
 465                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 466                                jiffies)) {
 467                         active++;
 468                         break;
 469                 }
 470         }
 471
 472         rcu_read_unlock();
 473
 474         return active;
 475 }
 476
 477 /*
 478  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 479  */
 480
 481 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 482 {
 483         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 484
 485         lockdep_assert_held(&ifibss->mtx);
 486
 487         mod_timer(&ifibss->timer,
 488                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 489
 490         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 491
 492         if (time_before(jiffies, ifibss->last_scan_completed +
 493                        IEEE80211_IBSS_MERGE_INTERVAL))
 494                 return;
 495
 496         if (ieee80211_sta_active_ibss(sdata))
 497                 return;
 498
 499         if (ifibss->fixed_channel)
 500                 return;
 501
 502         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 503                "IBSS networks with same SSID (merge)\n", sdata->name);
 504
 505         ieee80211_request_internal_scan(sdata,
 506                         ifibss->ssid, ifibss->ssid_len,
 507                         ifibss->fixed_channel ? ifibss->channel : NULL);
 508 }
 509
 510 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 511 {
 512         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 513         struct ieee80211_local *local = sdata->local;
 514         struct ieee80211_supported_band *sband;
 515         u8 bssid[ETH_ALEN];
 516         u16 capability;
 517         int i;
 518
 519         lockdep_assert_held(&ifibss->mtx);
 520
 521         if (ifibss->fixed_bssid) {
 522                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 523         } else {
 524                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 525                  * own MAC address to make sure that devices that do not have proper
 526                  * random number generator get different BSSID. */
 527                 get_random_bytes(bssid, ETH_ALEN);
 528                 for (i = 0; i < ETH_ALEN; i++)
 529                         bssid[i] ^= sdata->vif.addr[i];
 530                 bssid[0] &= ~0x01;
 531                 bssid[0] |= 0x02;
 532         }
 533
 534         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 535                sdata->name, bssid);
 536
 537         sband = local->hw.wiphy->bands[ifibss->channel->band];
 538
 539         capability = WLAN_CAPABILITY_IBSS;
 540
 541         if (ifibss->privacy)
 542                 capability |= WLAN_CAPABILITY_PRIVACY;
 543         else
 544                 sdata->drop_unencrypted = 0;
 545
 546         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 547                                   ifibss->channel, ifibss->basic_rates,
 548                                   capability, 0);
 549 }
 550
 551 /*
 552  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 553  */
 554
 555 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 556 {
 557         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 558         struct ieee80211_local *local = sdata->local;
 559         struct cfg80211_bss *cbss;
 560         struct ieee80211_channel *chan = NULL;
 561         const u8 *bssid = NULL;
 562         int active_ibss;
 563         u16 capability;
 564
 565         lockdep_assert_held(&ifibss->mtx);
 566
 567         active_ibss = ieee80211_sta_active_ibss(sdata);
 568 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 569         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 570                sdata->name, active_ibss);
 571 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 572
 573         if (active_ibss)
 574                 return;
 575
 576         capability = WLAN_CAPABILITY_IBSS;
 577         if (ifibss->privacy)
 578                 capability |= WLAN_CAPABILITY_PRIVACY;
 579         if (ifibss->fixed_bssid)
 580                 bssid = ifibss->bssid;
 581         if (ifibss->fixed_channel)
 582                 chan = ifibss->channel;
 583         if (!is_zero_ether_addr(ifibss->bssid))
 584                 bssid = ifibss->bssid;
 585         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 586                                 ifibss->ssid, ifibss->ssid_len,
 587                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 588                                 capability);
 589
 590         if (cbss) {
 591                 struct ieee80211_bss *bss;
 592
 593                 bss = (void *)cbss->priv;
 594 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 595                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 596                        "%pM\n", cbss->bssid, ifibss->bssid);
 597 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 598
 599                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 600                        " based on configured SSID\n",
 601                        sdata->name, cbss->bssid);
 602
 603                 ieee80211_sta_join_ibss(sdata, bss);
 604                 ieee80211_rx_bss_put(local, bss);
 605                 return;
 606         }
 607
 608 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 609         printk(KERN_DEBUG "   did not try to join ibss\n");
 610 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 611
 612         /* Selected IBSS not found in current scan results - try to scan */
 613         if (time_after(jiffies, ifibss->last_scan_completed +
 614                                         IEEE80211_SCAN_INTERVAL)) {
 615                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 616                        "join\n", sdata->name);
 617
 618                 ieee80211_request_internal_scan(sdata,
 619                                 ifibss->ssid, ifibss->ssid_len,
 620                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 621         } else {
 622                 int interval = IEEE80211_SCAN_INTERVAL;
 623
 624                 if (time_after(jiffies, ifibss->ibss_join_req +
 625                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 626                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 627                                 ieee80211_sta_create_ibss(sdata);
 628                                 return;
 629                         }
 630                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 631                                " %d MHz\n", sdata->name,
 632                                local->hw.conf.channel->center_freq);
 633
 634                         /* No IBSS found - decrease scan interval and continue
 635                          * scanning. */
 636                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 637                 }
 638
 639                 mod_timer(&ifibss->timer,
 640                           round_jiffies(jiffies + interval));
 641         }
 642 }
 643
 644 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 645                                         struct ieee80211_mgmt *mgmt,
 646                                         size_t len)
 647 {
 648         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 649         struct ieee80211_local *local = sdata->local;
 650         int tx_last_beacon;
 651         struct sk_buff *skb;
 652         struct ieee80211_mgmt *resp;
 653         u8 *pos, *end;
 654
 655         lockdep_assert_held(&ifibss->mtx);
 656
 657         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 658             len < 24 + 2 || !ifibss->presp)
 659                 return;
 660
 661         tx_last_beacon = drv_tx_last_beacon(local);
 662
 663 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 664         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 665                " (tx_last_beacon=%d)\n",
 666                sdata->name, mgmt->sa, mgmt->da,
 667                mgmt->bssid, tx_last_beacon);
 668 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 669
 670         if (!tx_last_beacon)
 671                 return;
 672
 673         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 674             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 675                 return;
 676
 677         end = ((u8 *) mgmt) + len;
 678         pos = mgmt->u.probe_req.variable;
 679         if (pos[0] != WLAN_EID_SSID ||
 680             pos + 2 + pos[1] > end) {
 681 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 682                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 683                        "from %pM\n",
 684                        sdata->name, mgmt->sa);
 685 #endif
 686                 return;
 687         }
 688         if (pos[1] != 0 &&
 689             (pos[1] != ifibss->ssid_len ||
 690              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 691                 /* Ignore ProbeReq for foreign SSID */
 692                 return;
 693         }
 694
 695         /* Reply with ProbeResp */
 696         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 697         if (!skb)
 698                 return;
 699
 700         resp = (struct ieee80211_mgmt *) skb->data;
 701         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 702 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 703         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 704                sdata->name, resp->da);
 705 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 706         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 707         ieee80211_tx_skb(sdata, skb);
 708 }
 709
 710 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 711                                          struct ieee80211_mgmt *mgmt,
 712                                          size_t len,
 713                                          struct ieee80211_rx_status *rx_status)
 714 {
 715         size_t baselen;
 716         struct ieee802_11_elems elems;
 717
 718         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 719                 return; /* ignore ProbeResp to foreign address */
 720
 721         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 722         if (baselen > len)
 723                 return;
 724
 725         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 726                                 &elems);
 727
 728         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 729 }
 730
 731 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 732                                      struct ieee80211_mgmt *mgmt,
 733                                      size_t len,
 734                                      struct ieee80211_rx_status *rx_status)
 735 {
 736         size_t baselen;
 737         struct ieee802_11_elems elems;
 738
 739         /* Process beacon from the current BSS */
 740         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 741         if (baselen > len)
 742                 return;
 743
 744         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 745
 746         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 747 }
 748
 749 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 750                                    struct sk_buff *skb)
 751 {
 752         struct ieee80211_rx_status *rx_status;
 753         struct ieee80211_mgmt *mgmt;
 754         u16 fc;
 755
 756         rx_status = IEEE80211_SKB_RXCB(skb);
 757         mgmt = (struct ieee80211_mgmt *) skb->data;
 758         fc = le16_to_cpu(mgmt->frame_control);
 759
 760         mutex_lock(&sdata->u.ibss.mtx);
 761
 762         switch (fc & IEEE80211_FCTL_STYPE) {
 763         case IEEE80211_STYPE_PROBE_REQ:
 764                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 765                 break;
 766         case IEEE80211_STYPE_PROBE_RESP:
 767                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 768                                              rx_status);
 769                 break;
 770         case IEEE80211_STYPE_BEACON:
 771                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 772                                          rx_status);
 773                 break;
 774         case IEEE80211_STYPE_AUTH:
 775                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 776                 break;
 777         }
 778
 779         mutex_unlock(&sdata->u.ibss.mtx);
 780 }
 781
 782 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 783 {
 784         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 785
 786         mutex_lock(&ifibss->mtx);
 787
 788         /*
 789          * Work could be scheduled after scan or similar
 790          * when we aren't even joined (or trying) with a
 791          * network.
 792          */
 793         if (!ifibss->ssid_len)
 794                 goto out;
 795
 796         switch (ifibss->state) {
 797         case IEEE80211_IBSS_MLME_SEARCH:
 798                 ieee80211_sta_find_ibss(sdata);
 799                 break;
 800         case IEEE80211_IBSS_MLME_JOINED:
 801                 ieee80211_sta_merge_ibss(sdata);
 802                 break;
 803         default:
 804                 WARN_ON(1);
 805                 break;
 806         }
 807
 808  out:
 809         mutex_unlock(&ifibss->mtx);
 810 }
 811
 812 static void ieee80211_ibss_timer(unsigned long data)
 813 {
 814         struct ieee80211_sub_if_data *sdata =
 815                 (struct ieee80211_sub_if_data *) data;
 816         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 817         struct ieee80211_local *local = sdata->local;
 818
 819         if (local->quiescing) {
 820                 ifibss->timer_running = true;
 821                 return;
 822         }
 823
 824         ieee80211_queue_work(&local->hw, &sdata->work);
 825 }
 826
 827 #ifdef CONFIG_PM
 828 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 829 {
 830         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 831
 832         if (del_timer_sync(&ifibss->timer))
 833                 ifibss->timer_running = true;
 834 }
 835
 836 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 837 {
 838         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 839
 840         if (ifibss->timer_running) {
 841                 add_timer(&ifibss->timer);
 842                 ifibss->timer_running = false;
 843         }
 844 }
 845 #endif
 846
 847 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 848 {
 849         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 850
 851         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 852                     (unsigned long) sdata);
 853         mutex_init(&ifibss->mtx);
 854 }
 855
 856 /* scan finished notification */
 857 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 858 {
 859         struct ieee80211_sub_if_data *sdata;
 860
 861         mutex_lock(&local->iflist_mtx);
 862         list_for_each_entry(sdata, &local->interfaces, list) {
 863                 if (!ieee80211_sdata_running(sdata))
 864                         continue;
 865                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 866                         continue;
 867                 sdata->u.ibss.last_scan_completed = jiffies;
 868                 ieee80211_queue_work(&local->hw, &sdata->work);
 869         }
 870         mutex_unlock(&local->iflist_mtx);
 871 }
 872
 873 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 874                         struct cfg80211_ibss_params *params)
 875 {
 876         struct sk_buff *skb;
 877
 878         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 879                             36 /* bitrates */ +
 880                             34 /* SSID */ +
 881                             3  /* DS params */ +
 882                             4  /* IBSS params */ +
 883                             params->ie_len);
 884         if (!skb)
 885                 return -ENOMEM;
 886
 887         mutex_lock(&sdata->u.ibss.mtx);
 888
 889         if (params->bssid) {
 890                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 891                 sdata->u.ibss.fixed_bssid = true;
 892         } else
 893                 sdata->u.ibss.fixed_bssid = false;
 894
 895         sdata->u.ibss.privacy = params->privacy;
 896         sdata->u.ibss.basic_rates = params->basic_rates;
 897
 898         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 899
 900         sdata->u.ibss.channel = params->channel;
 901         sdata->u.ibss.fixed_channel = params->channel_fixed;
 902
 903         /* fix ourselves to that channel now already */
 904         if (params->channel_fixed) {
 905                 sdata->local->oper_channel = params->channel;
 906                 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
 907                                                     NL80211_CHAN_NO_HT));
 908         }
 909
 910         if (params->ie) {
 911                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 912                                            GFP_KERNEL);
 913                 if (sdata->u.ibss.ie)
 914                         sdata->u.ibss.ie_len = params->ie_len;
 915         }
 916
 917         sdata->u.ibss.skb = skb;
 918         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 919         sdata->u.ibss.ibss_join_req = jiffies;
 920
 921         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 922         sdata->u.ibss.ssid_len = params->ssid_len;
 923
 924         ieee80211_recalc_idle(sdata->local);
 925
 926         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 927
 928         mutex_unlock(&sdata->u.ibss.mtx);
 929
 930         return 0;
 931 }
 932
 933 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 934 {
 935         struct sk_buff *skb;
 936         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 937         struct ieee80211_local *local = sdata->local;
 938         struct cfg80211_bss *cbss;
 939         u16 capability;
 940         int active_ibss;
 941
 942         mutex_lock(&sdata->u.ibss.mtx);
 943
 944         active_ibss = ieee80211_sta_active_ibss(sdata);
 945
 946         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
 947                 capability = WLAN_CAPABILITY_IBSS;
 948
 949                 if (ifibss->privacy)
 950                         capability |= WLAN_CAPABILITY_PRIVACY;
 951
 952                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
 953                                         ifibss->bssid, ifibss->ssid,
 954                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 955                                         WLAN_CAPABILITY_PRIVACY,
 956                                         capability);
 957
 958                 if (cbss) {
 959                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
 960                         cfg80211_put_bss(cbss);
 961                 }
 962         }
 963
 964         sta_info_flush(sdata->local, sdata);
 965
 966         /* remove beacon */
 967         kfree(sdata->u.ibss.ie);
 968         skb = sdata->u.ibss.presp;
 969         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 970         sdata->vif.bss_conf.ibss_joined = false;
 971         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 972                                                 BSS_CHANGED_IBSS);
 973         synchronize_rcu();
 974         kfree_skb(skb);
 975
 976         skb_queue_purge(&sdata->skb_queue);
 977         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 978         sdata->u.ibss.ssid_len = 0;
 979
 980         del_timer_sync(&sdata->u.ibss.timer);
 981
 982         mutex_unlock(&sdata->u.ibss.mtx);
 983
 984         ieee80211_recalc_idle(sdata->local);
 985
 986         return 0;
 987 }