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         bss_change = BSS_CHANGED_BEACON_INT;
 176         bss_change |= ieee80211_reset_erp_info(sdata);
 177         bss_change |= BSS_CHANGED_BSSID;
 178         bss_change |= BSS_CHANGED_BEACON;
 179         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 180         bss_change |= BSS_CHANGED_IBSS;
 181         sdata->vif.bss_conf.ibss_joined = true;
 182         ieee80211_bss_info_change_notify(sdata, bss_change);
 183
 184         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 185
 186         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 187         mod_timer(&ifibss->timer,
 188                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 189
 190         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 191                                         mgmt, skb->len, 0, GFP_KERNEL);
 192         cfg80211_put_bss(bss);
 193         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 194 }
 195
 196 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 197                                     struct ieee80211_bss *bss)
 198 {
 199         struct cfg80211_bss *cbss =
 200                 container_of((void *)bss, struct cfg80211_bss, priv);
 201         struct ieee80211_supported_band *sband;
 202         u32 basic_rates;
 203         int i, j;
 204         u16 beacon_int = cbss->beacon_interval;
 205
 206         if (beacon_int < 10)
 207                 beacon_int = 10;
 208
 209         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 210
 211         basic_rates = 0;
 212
 213         for (i = 0; i < bss->supp_rates_len; i++) {
 214                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 215                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 216
 217                 for (j = 0; j < sband->n_bitrates; j++) {
 218                         if (sband->bitrates[j].bitrate == rate) {
 219                                 if (is_basic)
 220                                         basic_rates |= BIT(j);
 221                                 break;
 222                         }
 223                 }
 224         }
 225
 226         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 227                                   beacon_int,
 228                                   cbss->channel,
 229                                   basic_rates,
 230                                   cbss->capability,
 231                                   cbss->tsf);
 232 }
 233
 234 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 235                                   struct ieee80211_mgmt *mgmt,
 236                                   size_t len,
 237                                   struct ieee80211_rx_status *rx_status,
 238                                   struct ieee802_11_elems *elems,
 239                                   bool beacon)
 240 {
 241         struct ieee80211_local *local = sdata->local;
 242         int freq;
 243         struct cfg80211_bss *cbss;
 244         struct ieee80211_bss *bss;
 245         struct sta_info *sta;
 246         struct ieee80211_channel *channel;
 247         u64 beacon_timestamp, rx_timestamp;
 248         u32 supp_rates = 0;
 249         enum ieee80211_band band = rx_status->band;
 250
 251         if (elems->ds_params && elems->ds_params_len == 1)
 252                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 253         else
 254                 freq = rx_status->freq;
 255
 256         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 257
 258         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 259                 return;
 260
 261         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 262             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 263                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 264
 265                 rcu_read_lock();
 266
 267                 sta = sta_info_get(sdata, mgmt->sa);
 268                 if (sta) {
 269                         u32 prev_rates;
 270
 271                         prev_rates = sta->sta.supp_rates[band];
 272                         /* make sure mandatory rates are always added */
 273                         sta->sta.supp_rates[band] = supp_rates |
 274                                 ieee80211_mandatory_rates(local, band);
 275
 276                         if (sta->sta.supp_rates[band] != prev_rates) {
 277 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 278                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 279                                     "for %pM based on beacon/probe_response "
 280                                     "(0x%x -> 0x%x)\n",
 281                                     sdata->name, sta->sta.addr,
 282                                     prev_rates, sta->sta.supp_rates[band]);
 283 #endif
 284                                 rate_control_rate_init(sta);
 285                         }
 286                         rcu_read_unlock();
 287                 } else {
 288                         rcu_read_unlock();
 289                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 290                                                supp_rates, GFP_KERNEL);
 291                 }
 292         }
 293
 294         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 295                                         channel, beacon);
 296         if (!bss)
 297                 return;
 298
 299         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 300
 301         /* was just updated in ieee80211_bss_info_update */
 302         beacon_timestamp = cbss->tsf;
 303
 304         /* check if we need to merge IBSS */
 305
 306         /* we use a fixed BSSID */
 307         if (sdata->u.ibss.fixed_bssid)
 308                 goto put_bss;
 309
 310         /* not an IBSS */
 311         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 312                 goto put_bss;
 313
 314         /* different channel */
 315         if (cbss->channel != local->oper_channel)
 316                 goto put_bss;
 317
 318         /* different SSID */
 319         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 320             memcmp(elems->ssid, sdata->u.ibss.ssid,
 321                                 sdata->u.ibss.ssid_len))
 322                 goto put_bss;
 323
 324         /* same BSSID */
 325         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 326                 goto put_bss;
 327
 328         if (rx_status->flag & RX_FLAG_TSFT) {
 329                 /*
 330                  * For correct IBSS merging we need mactime; since mactime is
 331                  * defined as the time the first data symbol of the frame hits
 332                  * the PHY, and the timestamp of the beacon is defined as "the
 333                  * time that the data symbol containing the first bit of the
 334                  * timestamp is transmitted to the PHY plus the transmitting
 335                  * STA's delays through its local PHY from the MAC-PHY
 336                  * interface to its interface with the WM" (802.11 11.1.2)
 337                  * - equals the time this bit arrives at the receiver - we have
 338                  * to take into account the offset between the two.
 339                  *
 340                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 341                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 342                  */
 343                 int rate;
 344
 345                 if (rx_status->flag & RX_FLAG_HT)
 346                         rate = 65; /* TODO: HT rates */
 347                 else
 348                         rate = local->hw.wiphy->bands[band]->
 349                                 bitrates[rx_status->rate_idx].bitrate;
 350
 351                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 352         } else {
 353                 /*
 354                  * second best option: get current TSF
 355                  * (will return -1 if not supported)
 356                  */
 357                 rx_timestamp = drv_get_tsf(local);
 358         }
 359
 360 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 361         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 362                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 363                mgmt->sa, mgmt->bssid,
 364                (unsigned long long)rx_timestamp,
 365                (unsigned long long)beacon_timestamp,
 366                (unsigned long long)(rx_timestamp - beacon_timestamp),
 367                jiffies);
 368 #endif
 369
 370         /* give slow hardware some time to do the TSF sync */
 371         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 372                 goto put_bss;
 373
 374         if (beacon_timestamp > rx_timestamp) {
 375 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 376                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 377                        "local TSF - IBSS merge with BSSID %pM\n",
 378                        sdata->name, mgmt->bssid);
 379 #endif
 380                 ieee80211_sta_join_ibss(sdata, bss);
 381                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 382                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 383                                        supp_rates, GFP_KERNEL);
 384         }
 385
 386  put_bss:
 387         ieee80211_rx_bss_put(local, bss);
 388 }
 389
 390 /*
 391  * Add a new IBSS station, will also be called by the RX code when,
 392  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 393  * must be callable in atomic context.
 394  */
 395 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 396                                         u8 *bssid,u8 *addr, u32 supp_rates,
 397                                         gfp_t gfp)
 398 {
 399         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 400         struct ieee80211_local *local = sdata->local;
 401         struct sta_info *sta;
 402         int band = local->hw.conf.channel->band;
 403
 404         /*
 405          * XXX: Consider removing the least recently used entry and
 406          *      allow new one to be added.
 407          */
 408         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 409                 if (net_ratelimit())
 410                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 411                                sdata->name, addr);
 412                 return NULL;
 413         }
 414
 415         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 416                 return NULL;
 417
 418         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 419                 return NULL;
 420
 421 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 422         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 423                wiphy_name(local->hw.wiphy), addr, sdata->name);
 424 #endif
 425
 426         sta = sta_info_alloc(sdata, addr, gfp);
 427         if (!sta)
 428                 return NULL;
 429
 430         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 431
 432         /* make sure mandatory rates are always added */
 433         sta->sta.supp_rates[band] = supp_rates |
 434                         ieee80211_mandatory_rates(local, band);
 435
 436         rate_control_rate_init(sta);
 437
 438         /* If it fails, maybe we raced another insertion? */
 439         if (sta_info_insert(sta))
 440                 return sta_info_get(sdata, addr);
 441         return sta;
 442 }
 443
 444 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 445 {
 446         struct ieee80211_local *local = sdata->local;
 447         int active = 0;
 448         struct sta_info *sta;
 449
 450         rcu_read_lock();
 451
 452         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 453                 if (sta->sdata == sdata &&
 454                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 455                                jiffies)) {
 456                         active++;
 457                         break;
 458                 }
 459         }
 460
 461         rcu_read_unlock();
 462
 463         return active;
 464 }
 465
 466 /*
 467  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 468  */
 469
 470 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 471 {
 472         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 473
 474         mod_timer(&ifibss->timer,
 475                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 476
 477         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 478
 479         if (time_before(jiffies, ifibss->last_scan_completed +
 480                        IEEE80211_IBSS_MERGE_INTERVAL))
 481                 return;
 482
 483         if (ieee80211_sta_active_ibss(sdata))
 484                 return;
 485
 486         if (ifibss->fixed_channel)
 487                 return;
 488
 489         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 490                "IBSS networks with same SSID (merge)\n", sdata->name);
 491
 492         ieee80211_request_internal_scan(sdata,
 493                         ifibss->ssid, ifibss->ssid_len,
 494                         ifibss->fixed_channel ? ifibss->channel : NULL);
 495 }
 496
 497 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 498 {
 499         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 500         struct ieee80211_local *local = sdata->local;
 501         struct ieee80211_supported_band *sband;
 502         u8 bssid[ETH_ALEN];
 503         u16 capability;
 504         int i;
 505
 506         if (ifibss->fixed_bssid) {
 507                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 508         } else {
 509                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 510                  * own MAC address to make sure that devices that do not have proper
 511                  * random number generator get different BSSID. */
 512                 get_random_bytes(bssid, ETH_ALEN);
 513                 for (i = 0; i < ETH_ALEN; i++)
 514                         bssid[i] ^= sdata->vif.addr[i];
 515                 bssid[0] &= ~0x01;
 516                 bssid[0] |= 0x02;
 517         }
 518
 519         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 520                sdata->name, bssid);
 521
 522         sband = local->hw.wiphy->bands[ifibss->channel->band];
 523
 524         capability = WLAN_CAPABILITY_IBSS;
 525
 526         if (ifibss->privacy)
 527                 capability |= WLAN_CAPABILITY_PRIVACY;
 528         else
 529                 sdata->drop_unencrypted = 0;
 530
 531         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 532                                   ifibss->channel, 3, /* first two are basic */
 533                                   capability, 0);
 534 }
 535
 536 /*
 537  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 538  */
 539
 540 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 541 {
 542         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 543         struct ieee80211_local *local = sdata->local;
 544         struct cfg80211_bss *cbss;
 545         struct ieee80211_channel *chan = NULL;
 546         const u8 *bssid = NULL;
 547         int active_ibss;
 548         u16 capability;
 549
 550         active_ibss = ieee80211_sta_active_ibss(sdata);
 551 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 552         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 553                sdata->name, active_ibss);
 554 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 555
 556         if (active_ibss)
 557                 return;
 558
 559         capability = WLAN_CAPABILITY_IBSS;
 560         if (ifibss->privacy)
 561                 capability |= WLAN_CAPABILITY_PRIVACY;
 562         if (ifibss->fixed_bssid)
 563                 bssid = ifibss->bssid;
 564         if (ifibss->fixed_channel)
 565                 chan = ifibss->channel;
 566         if (!is_zero_ether_addr(ifibss->bssid))
 567                 bssid = ifibss->bssid;
 568         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 569                                 ifibss->ssid, ifibss->ssid_len,
 570                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 571                                 capability);
 572
 573         if (cbss) {
 574                 struct ieee80211_bss *bss;
 575
 576                 bss = (void *)cbss->priv;
 577 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 578                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 579                        "%pM\n", cbss->bssid, ifibss->bssid);
 580 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 581
 582                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 583                        " based on configured SSID\n",
 584                        sdata->name, cbss->bssid);
 585
 586                 ieee80211_sta_join_ibss(sdata, bss);
 587                 ieee80211_rx_bss_put(local, bss);
 588                 return;
 589         }
 590
 591 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 592         printk(KERN_DEBUG "   did not try to join ibss\n");
 593 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 594
 595         /* Selected IBSS not found in current scan results - try to scan */
 596         if (time_after(jiffies, ifibss->last_scan_completed +
 597                                         IEEE80211_SCAN_INTERVAL)) {
 598                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 599                        "join\n", sdata->name);
 600
 601                 ieee80211_request_internal_scan(sdata,
 602                                 ifibss->ssid, ifibss->ssid_len,
 603                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 604         } else {
 605                 int interval = IEEE80211_SCAN_INTERVAL;
 606
 607                 if (time_after(jiffies, ifibss->ibss_join_req +
 608                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 609                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 610                                 ieee80211_sta_create_ibss(sdata);
 611                                 return;
 612                         }
 613                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 614                                " %d MHz\n", sdata->name,
 615                                local->hw.conf.channel->center_freq);
 616
 617                         /* No IBSS found - decrease scan interval and continue
 618                          * scanning. */
 619                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 620                 }
 621
 622                 mod_timer(&ifibss->timer,
 623                           round_jiffies(jiffies + interval));
 624         }
 625 }
 626
 627 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 628                                         struct ieee80211_mgmt *mgmt,
 629                                         size_t len)
 630 {
 631         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 632         struct ieee80211_local *local = sdata->local;
 633         int tx_last_beacon;
 634         struct sk_buff *skb;
 635         struct ieee80211_mgmt *resp;
 636         u8 *pos, *end;
 637
 638         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 639             len < 24 + 2 || !ifibss->presp)
 640                 return;
 641
 642         tx_last_beacon = drv_tx_last_beacon(local);
 643
 644 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 645         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 646                " (tx_last_beacon=%d)\n",
 647                sdata->name, mgmt->sa, mgmt->da,
 648                mgmt->bssid, tx_last_beacon);
 649 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 650
 651         if (!tx_last_beacon)
 652                 return;
 653
 654         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 655             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 656                 return;
 657
 658         end = ((u8 *) mgmt) + len;
 659         pos = mgmt->u.probe_req.variable;
 660         if (pos[0] != WLAN_EID_SSID ||
 661             pos + 2 + pos[1] > end) {
 662 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 663                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 664                        "from %pM\n",
 665                        sdata->name, mgmt->sa);
 666 #endif
 667                 return;
 668         }
 669         if (pos[1] != 0 &&
 670             (pos[1] != ifibss->ssid_len ||
 671              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 672                 /* Ignore ProbeReq for foreign SSID */
 673                 return;
 674         }
 675
 676         /* Reply with ProbeResp */
 677         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 678         if (!skb)
 679                 return;
 680
 681         resp = (struct ieee80211_mgmt *) skb->data;
 682         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 683 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 684         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 685                sdata->name, resp->da);
 686 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 687         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 688         ieee80211_tx_skb(sdata, skb);
 689 }
 690
 691 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 692                                          struct ieee80211_mgmt *mgmt,
 693                                          size_t len,
 694                                          struct ieee80211_rx_status *rx_status)
 695 {
 696         size_t baselen;
 697         struct ieee802_11_elems elems;
 698
 699         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 700                 return; /* ignore ProbeResp to foreign address */
 701
 702         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 703         if (baselen > len)
 704                 return;
 705
 706         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 707                                 &elems);
 708
 709         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 710 }
 711
 712 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 713                                      struct ieee80211_mgmt *mgmt,
 714                                      size_t len,
 715                                      struct ieee80211_rx_status *rx_status)
 716 {
 717         size_t baselen;
 718         struct ieee802_11_elems elems;
 719
 720         /* Process beacon from the current BSS */
 721         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 722         if (baselen > len)
 723                 return;
 724
 725         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 726
 727         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 728 }
 729
 730 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 731                                           struct sk_buff *skb)
 732 {
 733         struct ieee80211_rx_status *rx_status;
 734         struct ieee80211_mgmt *mgmt;
 735         u16 fc;
 736
 737         rx_status = IEEE80211_SKB_RXCB(skb);
 738         mgmt = (struct ieee80211_mgmt *) skb->data;
 739         fc = le16_to_cpu(mgmt->frame_control);
 740
 741         switch (fc & IEEE80211_FCTL_STYPE) {
 742         case IEEE80211_STYPE_PROBE_REQ:
 743                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 744                 break;
 745         case IEEE80211_STYPE_PROBE_RESP:
 746                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 747                                              rx_status);
 748                 break;
 749         case IEEE80211_STYPE_BEACON:
 750                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 751                                          rx_status);
 752                 break;
 753         case IEEE80211_STYPE_AUTH:
 754                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 755                 break;
 756         }
 757
 758         kfree_skb(skb);
 759 }
 760
 761 static void ieee80211_ibss_work(struct work_struct *work)
 762 {
 763         struct ieee80211_sub_if_data *sdata =
 764                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 765         struct ieee80211_local *local = sdata->local;
 766         struct ieee80211_if_ibss *ifibss;
 767         struct sk_buff *skb;
 768
 769         if (WARN_ON(local->suspended))
 770                 return;
 771
 772         if (!ieee80211_sdata_running(sdata))
 773                 return;
 774
 775         if (local->scanning)
 776                 return;
 777
 778         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 779                 return;
 780         ifibss = &sdata->u.ibss;
 781
 782         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 783                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 784
 785         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 786                 return;
 787
 788         switch (ifibss->state) {
 789         case IEEE80211_IBSS_MLME_SEARCH:
 790                 ieee80211_sta_find_ibss(sdata);
 791                 break;
 792         case IEEE80211_IBSS_MLME_JOINED:
 793                 ieee80211_sta_merge_ibss(sdata);
 794                 break;
 795         default:
 796                 WARN_ON(1);
 797                 break;
 798         }
 799 }
 800
 801 static void ieee80211_ibss_timer(unsigned long data)
 802 {
 803         struct ieee80211_sub_if_data *sdata =
 804                 (struct ieee80211_sub_if_data *) data;
 805         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 806         struct ieee80211_local *local = sdata->local;
 807
 808         if (local->quiescing) {
 809                 ifibss->timer_running = true;
 810                 return;
 811         }
 812
 813         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 814         ieee80211_queue_work(&local->hw, &ifibss->work);
 815 }
 816
 817 #ifdef CONFIG_PM
 818 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 819 {
 820         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 821
 822         cancel_work_sync(&ifibss->work);
 823         if (del_timer_sync(&ifibss->timer))
 824                 ifibss->timer_running = true;
 825 }
 826
 827 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 828 {
 829         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 830
 831         if (ifibss->timer_running) {
 832                 add_timer(&ifibss->timer);
 833                 ifibss->timer_running = false;
 834         }
 835 }
 836 #endif
 837
 838 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 839 {
 840         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 841
 842         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 843         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 844                     (unsigned long) sdata);
 845         skb_queue_head_init(&ifibss->skb_queue);
 846 }
 847
 848 /* scan finished notification */
 849 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 850 {
 851         struct ieee80211_sub_if_data *sdata;
 852
 853         mutex_lock(&local->iflist_mtx);
 854         list_for_each_entry(sdata, &local->interfaces, list) {
 855                 if (!ieee80211_sdata_running(sdata))
 856                         continue;
 857                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 858                         continue;
 859                 if (!sdata->u.ibss.ssid_len)
 860                         continue;
 861                 sdata->u.ibss.last_scan_completed = jiffies;
 862                 mod_timer(&sdata->u.ibss.timer, 0);
 863         }
 864         mutex_unlock(&local->iflist_mtx);
 865 }
 866
 867 ieee80211_rx_result
 868 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 869 {
 870         struct ieee80211_local *local = sdata->local;
 871         struct ieee80211_mgmt *mgmt;
 872         u16 fc;
 873
 874         if (skb->len < 24)
 875                 return RX_DROP_MONITOR;
 876
 877         mgmt = (struct ieee80211_mgmt *) skb->data;
 878         fc = le16_to_cpu(mgmt->frame_control);
 879
 880         switch (fc & IEEE80211_FCTL_STYPE) {
 881         case IEEE80211_STYPE_PROBE_RESP:
 882         case IEEE80211_STYPE_BEACON:
 883         case IEEE80211_STYPE_PROBE_REQ:
 884         case IEEE80211_STYPE_AUTH:
 885                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 886                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 887                 return RX_QUEUED;
 888         }
 889
 890         return RX_DROP_MONITOR;
 891 }
 892
 893 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 894                         struct cfg80211_ibss_params *params)
 895 {
 896         struct sk_buff *skb;
 897
 898         if (params->bssid) {
 899                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 900                 sdata->u.ibss.fixed_bssid = true;
 901         } else
 902                 sdata->u.ibss.fixed_bssid = false;
 903
 904         sdata->u.ibss.privacy = params->privacy;
 905
 906         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 907
 908         sdata->u.ibss.channel = params->channel;
 909         sdata->u.ibss.fixed_channel = params->channel_fixed;
 910
 911         /* fix ourselves to that channel now already */
 912         if (params->channel_fixed) {
 913                 sdata->local->oper_channel = params->channel;
 914                 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
 915                                                     NL80211_CHAN_NO_HT));
 916         }
 917
 918         if (params->ie) {
 919                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 920                                            GFP_KERNEL);
 921                 if (sdata->u.ibss.ie)
 922                         sdata->u.ibss.ie_len = params->ie_len;
 923         }
 924
 925         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 926                             36 /* bitrates */ +
 927                             34 /* SSID */ +
 928                             3  /* DS params */ +
 929                             4  /* IBSS params */ +
 930                             params->ie_len);
 931         if (!skb)
 932                 return -ENOMEM;
 933
 934         sdata->u.ibss.skb = skb;
 935         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 936         sdata->u.ibss.ibss_join_req = jiffies;
 937
 938         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 939
 940         /*
 941          * The ssid_len setting below is used to see whether
 942          * we are active, and we need all other settings
 943          * before that may get visible.
 944          */
 945         mb();
 946
 947         sdata->u.ibss.ssid_len = params->ssid_len;
 948
 949         ieee80211_recalc_idle(sdata->local);
 950
 951         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 952         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 953
 954         return 0;
 955 }
 956
 957 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 958 {
 959         struct sk_buff *skb;
 960
 961         del_timer_sync(&sdata->u.ibss.timer);
 962         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 963         cancel_work_sync(&sdata->u.ibss.work);
 964         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 965
 966         sta_info_flush(sdata->local, sdata);
 967
 968         /* remove beacon */
 969         kfree(sdata->u.ibss.ie);
 970         skb = sdata->u.ibss.presp;
 971         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 972         sdata->vif.bss_conf.ibss_joined = false;
 973         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 974                                                 BSS_CHANGED_IBSS);
 975         synchronize_rcu();
 976         kfree_skb(skb);
 977
 978         skb_queue_purge(&sdata->u.ibss.skb_queue);
 979         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 980         sdata->u.ibss.ssid_len = 0;
 981
 982         ieee80211_recalc_idle(sdata->local);
 983
 984         return 0;
 985 }