net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/mac80211.h>
  22 #include <asm/unaligned.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "rate.h"
  27
  28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  29 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  31
  32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  33 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  35
  36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  37
  38
  39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  40                                         struct ieee80211_mgmt *mgmt,
  41                                         size_t len)
  42 {
  43         u16 auth_alg, auth_transaction, status_code;
  44
  45         if (len < 24 + 6)
  46                 return;
  47
  48         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  49         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  50         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  51
  52         /*
  53          * IEEE 802.11 standard does not require authentication in IBSS
  54          * networks and most implementations do not seem to use it.
  55          * However, try to reply to authentication attempts if someone
  56          * has actually implemented this.
  57          */
  58         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  59                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  60                                     sdata->u.ibss.bssid, NULL, 0, 0);
  61 }
  62
  63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  64                                       const u8 *bssid, const int beacon_int,
  65                                       struct ieee80211_channel *chan,
  66                                       const u32 basic_rates,
  67                                       const u16 capability, u64 tsf)
  68 {
  69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  70         struct ieee80211_local *local = sdata->local;
  71         int rates, i;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76         struct cfg80211_bss *bss;
  77         u32 bss_change;
  78         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  79
  80         /* Reset own TSF to allow time synchronization work. */
  81         drv_reset_tsf(local);
  82
  83         skb = ifibss->skb;
  84         rcu_assign_pointer(ifibss->presp, NULL);
  85         synchronize_rcu();
  86         skb->data = skb->head;
  87         skb->len = 0;
  88         skb_reset_tail_pointer(skb);
  89         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  90
  91         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  92                 sta_info_flush(sdata->local, sdata);
  93
  94         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  95
  96         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  97
  98         local->oper_channel = chan;
  99         local->oper_channel_type = NL80211_CHAN_NO_HT;
 100         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 101
 102         sband = local->hw.wiphy->bands[chan->band];
 103
 104         /* build supported rates array */
 105         pos = supp_rates;
 106         for (i = 0; i < sband->n_bitrates; i++) {
 107                 int rate = sband->bitrates[i].bitrate;
 108                 u8 basic = 0;
 109                 if (basic_rates & BIT(i))
 110                         basic = 0x80;
 111                 *pos++ = basic | (u8) (rate / 5);
 112         }
 113
 114         /* Build IBSS probe response */
 115         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 116         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 117         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 118                                           IEEE80211_STYPE_PROBE_RESP);
 119         memset(mgmt->da, 0xff, ETH_ALEN);
 120         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 121         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 122         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 123         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 124         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 125
 126         pos = skb_put(skb, 2 + ifibss->ssid_len);
 127         *pos++ = WLAN_EID_SSID;
 128         *pos++ = ifibss->ssid_len;
 129         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 130
 131         rates = sband->n_bitrates;
 132         if (rates > 8)
 133                 rates = 8;
 134         pos = skb_put(skb, 2 + rates);
 135         *pos++ = WLAN_EID_SUPP_RATES;
 136         *pos++ = rates;
 137         memcpy(pos, supp_rates, rates);
 138
 139         if (sband->band == IEEE80211_BAND_2GHZ) {
 140                 pos = skb_put(skb, 2 + 1);
 141                 *pos++ = WLAN_EID_DS_PARAMS;
 142                 *pos++ = 1;
 143                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 144         }
 145
 146         pos = skb_put(skb, 2 + 2);
 147         *pos++ = WLAN_EID_IBSS_PARAMS;
 148         *pos++ = 2;
 149         /* FIX: set ATIM window based on scan results */
 150         *pos++ = 0;
 151         *pos++ = 0;
 152
 153         if (sband->n_bitrates > 8) {
 154                 rates = sband->n_bitrates - 8;
 155                 pos = skb_put(skb, 2 + rates);
 156                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 157                 *pos++ = rates;
 158                 memcpy(pos, &supp_rates[8], rates);
 159         }
 160
 161         if (ifibss->ie_len)
 162                 memcpy(skb_put(skb, ifibss->ie_len),
 163                        ifibss->ie, ifibss->ie_len);
 164
 165         rcu_assign_pointer(ifibss->presp, skb);
 166
 167         sdata->vif.bss_conf.beacon_int = beacon_int;
 168         bss_change = BSS_CHANGED_BEACON_INT;
 169         bss_change |= ieee80211_reset_erp_info(sdata);
 170         bss_change |= BSS_CHANGED_BSSID;
 171         bss_change |= BSS_CHANGED_BEACON;
 172         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 173         ieee80211_bss_info_change_notify(sdata, bss_change);
 174
 175         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 176
 177         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 178         mod_timer(&ifibss->timer,
 179                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 180
 181         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 182                                         mgmt, skb->len, 0, GFP_KERNEL);
 183         cfg80211_put_bss(bss);
 184         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 185 }
 186
 187 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 188                                     struct ieee80211_bss *bss)
 189 {
 190         struct cfg80211_bss *cbss =
 191                 container_of((void *)bss, struct cfg80211_bss, priv);
 192         struct ieee80211_supported_band *sband;
 193         u32 basic_rates;
 194         int i, j;
 195         u16 beacon_int = cbss->beacon_interval;
 196
 197         if (beacon_int < 10)
 198                 beacon_int = 10;
 199
 200         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 201
 202         basic_rates = 0;
 203
 204         for (i = 0; i < bss->supp_rates_len; i++) {
 205                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 206                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 207
 208                 for (j = 0; j < sband->n_bitrates; j++) {
 209                         if (sband->bitrates[j].bitrate == rate) {
 210                                 if (is_basic)
 211                                         basic_rates |= BIT(j);
 212                                 break;
 213                         }
 214                 }
 215         }
 216
 217         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 218                                   beacon_int,
 219                                   cbss->channel,
 220                                   basic_rates,
 221                                   cbss->capability,
 222                                   cbss->tsf);
 223 }
 224
 225 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 226                                   struct ieee80211_mgmt *mgmt,
 227                                   size_t len,
 228                                   struct ieee80211_rx_status *rx_status,
 229                                   struct ieee802_11_elems *elems,
 230                                   bool beacon)
 231 {
 232         struct ieee80211_local *local = sdata->local;
 233         int freq;
 234         struct cfg80211_bss *cbss;
 235         struct ieee80211_bss *bss;
 236         struct sta_info *sta;
 237         struct ieee80211_channel *channel;
 238         u64 beacon_timestamp, rx_timestamp;
 239         u32 supp_rates = 0;
 240         enum ieee80211_band band = rx_status->band;
 241
 242         if (elems->ds_params && elems->ds_params_len == 1)
 243                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 244         else
 245                 freq = rx_status->freq;
 246
 247         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 248
 249         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 250                 return;
 251
 252         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 253             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 254                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 255
 256                 rcu_read_lock();
 257
 258                 sta = sta_info_get(sdata, mgmt->sa);
 259                 if (sta) {
 260                         u32 prev_rates;
 261
 262                         prev_rates = sta->sta.supp_rates[band];
 263                         /* make sure mandatory rates are always added */
 264                         sta->sta.supp_rates[band] = supp_rates |
 265                                 ieee80211_mandatory_rates(local, band);
 266
 267 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 268                         if (sta->sta.supp_rates[band] != prev_rates)
 269                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 270                                     "for %pM based on beacon info (0x%llx | "
 271                                     "0x%llx -> 0x%llx)\n",
 272                                     sdata->name,
 273                                     sta->sta.addr,
 274                                     (unsigned long long) prev_rates,
 275                                     (unsigned long long) supp_rates,
 276                                     (unsigned long long) sta->sta.supp_rates[band]);
 277 #endif
 278                 } else
 279                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 280
 281                 rcu_read_unlock();
 282         }
 283
 284         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 285                                         channel, beacon);
 286         if (!bss)
 287                 return;
 288
 289         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 290
 291         /* was just updated in ieee80211_bss_info_update */
 292         beacon_timestamp = cbss->tsf;
 293
 294         /* check if we need to merge IBSS */
 295
 296         /* we use a fixed BSSID */
 297         if (sdata->u.ibss.fixed_bssid)
 298                 goto put_bss;
 299
 300         /* not an IBSS */
 301         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 302                 goto put_bss;
 303
 304         /* different channel */
 305         if (cbss->channel != local->oper_channel)
 306                 goto put_bss;
 307
 308         /* different SSID */
 309         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 310             memcmp(elems->ssid, sdata->u.ibss.ssid,
 311                                 sdata->u.ibss.ssid_len))
 312                 goto put_bss;
 313
 314         /* same BSSID */
 315         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 316                 goto put_bss;
 317
 318         if (rx_status->flag & RX_FLAG_TSFT) {
 319                 /*
 320                  * For correct IBSS merging we need mactime; since mactime is
 321                  * defined as the time the first data symbol of the frame hits
 322                  * the PHY, and the timestamp of the beacon is defined as "the
 323                  * time that the data symbol containing the first bit of the
 324                  * timestamp is transmitted to the PHY plus the transmitting
 325                  * STA's delays through its local PHY from the MAC-PHY
 326                  * interface to its interface with the WM" (802.11 11.1.2)
 327                  * - equals the time this bit arrives at the receiver - we have
 328                  * to take into account the offset between the two.
 329                  *
 330                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 331                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 332                  */
 333                 int rate;
 334
 335                 if (rx_status->flag & RX_FLAG_HT)
 336                         rate = 65; /* TODO: HT rates */
 337                 else
 338                         rate = local->hw.wiphy->bands[band]->
 339                                 bitrates[rx_status->rate_idx].bitrate;
 340
 341                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 342         } else {
 343                 /*
 344                  * second best option: get current TSF
 345                  * (will return -1 if not supported)
 346                  */
 347                 rx_timestamp = drv_get_tsf(local);
 348         }
 349
 350 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 351         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 352                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 353                mgmt->sa, mgmt->bssid,
 354                (unsigned long long)rx_timestamp,
 355                (unsigned long long)beacon_timestamp,
 356                (unsigned long long)(rx_timestamp - beacon_timestamp),
 357                jiffies);
 358 #endif
 359
 360         /* give slow hardware some time to do the TSF sync */
 361         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 362                 goto put_bss;
 363
 364         if (beacon_timestamp > rx_timestamp) {
 365 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 366                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 367                        "local TSF - IBSS merge with BSSID %pM\n",
 368                        sdata->name, mgmt->bssid);
 369 #endif
 370                 ieee80211_sta_join_ibss(sdata, bss);
 371                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 372         }
 373
 374  put_bss:
 375         ieee80211_rx_bss_put(local, bss);
 376 }
 377
 378 /*
 379  * Add a new IBSS station, will also be called by the RX code when,
 380  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 381  * must be callable in atomic context.
 382  */
 383 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 384                                         u8 *bssid,u8 *addr, u32 supp_rates)
 385 {
 386         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 387         struct ieee80211_local *local = sdata->local;
 388         struct sta_info *sta;
 389         int band = local->hw.conf.channel->band;
 390
 391         /*
 392          * XXX: Consider removing the least recently used entry and
 393          *      allow new one to be added.
 394          */
 395         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 396                 if (net_ratelimit())
 397                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 398                                sdata->name, addr);
 399                 return NULL;
 400         }
 401
 402         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 403                 return NULL;
 404
 405         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 406                 return NULL;
 407
 408 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 409         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 410                wiphy_name(local->hw.wiphy), addr, sdata->name);
 411 #endif
 412
 413         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 414         if (!sta)
 415                 return NULL;
 416
 417         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 418
 419         /* make sure mandatory rates are always added */
 420         sta->sta.supp_rates[band] = supp_rates |
 421                         ieee80211_mandatory_rates(local, band);
 422
 423         rate_control_rate_init(sta);
 424
 425         if (sta_info_insert(sta))
 426                 return NULL;
 427
 428         return sta;
 429 }
 430
 431 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 432 {
 433         struct ieee80211_local *local = sdata->local;
 434         int active = 0;
 435         struct sta_info *sta;
 436
 437         rcu_read_lock();
 438
 439         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 440                 if (sta->sdata == sdata &&
 441                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 442                                jiffies)) {
 443                         active++;
 444                         break;
 445                 }
 446         }
 447
 448         rcu_read_unlock();
 449
 450         return active;
 451 }
 452
 453 /*
 454  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 455  */
 456
 457 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 458 {
 459         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 460
 461         mod_timer(&ifibss->timer,
 462                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 463
 464         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 465
 466         if (time_before(jiffies, ifibss->last_scan_completed +
 467                        IEEE80211_IBSS_MERGE_INTERVAL))
 468                 return;
 469
 470         if (ieee80211_sta_active_ibss(sdata))
 471                 return;
 472
 473         if (ifibss->fixed_channel)
 474                 return;
 475
 476         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 477                "IBSS networks with same SSID (merge)\n", sdata->name);
 478
 479         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 480 }
 481
 482 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 483 {
 484         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 485         struct ieee80211_local *local = sdata->local;
 486         struct ieee80211_supported_band *sband;
 487         u8 bssid[ETH_ALEN];
 488         u16 capability;
 489         int i;
 490
 491         if (ifibss->fixed_bssid) {
 492                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 493         } else {
 494                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 495                  * own MAC address to make sure that devices that do not have proper
 496                  * random number generator get different BSSID. */
 497                 get_random_bytes(bssid, ETH_ALEN);
 498                 for (i = 0; i < ETH_ALEN; i++)
 499                         bssid[i] ^= sdata->vif.addr[i];
 500                 bssid[0] &= ~0x01;
 501                 bssid[0] |= 0x02;
 502         }
 503
 504         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 505                sdata->name, bssid);
 506
 507         sband = local->hw.wiphy->bands[ifibss->channel->band];
 508
 509         capability = WLAN_CAPABILITY_IBSS;
 510
 511         if (ifibss->privacy)
 512                 capability |= WLAN_CAPABILITY_PRIVACY;
 513         else
 514                 sdata->drop_unencrypted = 0;
 515
 516         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 517                                   ifibss->channel, 3, /* first two are basic */
 518                                   capability, 0);
 519 }
 520
 521 /*
 522  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 523  */
 524
 525 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 526 {
 527         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 528         struct ieee80211_local *local = sdata->local;
 529         struct cfg80211_bss *cbss;
 530         struct ieee80211_channel *chan = NULL;
 531         const u8 *bssid = NULL;
 532         int active_ibss;
 533         u16 capability;
 534
 535         active_ibss = ieee80211_sta_active_ibss(sdata);
 536 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 537         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 538                sdata->name, active_ibss);
 539 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 540
 541         if (active_ibss)
 542                 return;
 543
 544         capability = WLAN_CAPABILITY_IBSS;
 545         if (ifibss->privacy)
 546                 capability |= WLAN_CAPABILITY_PRIVACY;
 547         if (ifibss->fixed_bssid)
 548                 bssid = ifibss->bssid;
 549         if (ifibss->fixed_channel)
 550                 chan = ifibss->channel;
 551         if (!is_zero_ether_addr(ifibss->bssid))
 552                 bssid = ifibss->bssid;
 553         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 554                                 ifibss->ssid, ifibss->ssid_len,
 555                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 556                                 capability);
 557
 558         if (cbss) {
 559                 struct ieee80211_bss *bss;
 560
 561                 bss = (void *)cbss->priv;
 562 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 563                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 564                        "%pM\n", cbss->bssid, ifibss->bssid);
 565 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 566
 567                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 568                        " based on configured SSID\n",
 569                        sdata->name, cbss->bssid);
 570
 571                 ieee80211_sta_join_ibss(sdata, bss);
 572                 ieee80211_rx_bss_put(local, bss);
 573                 return;
 574         }
 575
 576 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 577         printk(KERN_DEBUG "   did not try to join ibss\n");
 578 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 579
 580         /* Selected IBSS not found in current scan results - try to scan */
 581         if (time_after(jiffies, ifibss->last_scan_completed +
 582                                         IEEE80211_SCAN_INTERVAL)) {
 583                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 584                        "join\n", sdata->name);
 585
 586                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 587                                                 ifibss->ssid_len);
 588         } else {
 589                 int interval = IEEE80211_SCAN_INTERVAL;
 590
 591                 if (time_after(jiffies, ifibss->ibss_join_req +
 592                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 593                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 594                                 ieee80211_sta_create_ibss(sdata);
 595                                 return;
 596                         }
 597                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 598                                " %d MHz\n", sdata->name,
 599                                local->hw.conf.channel->center_freq);
 600
 601                         /* No IBSS found - decrease scan interval and continue
 602                          * scanning. */
 603                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 604                 }
 605
 606                 mod_timer(&ifibss->timer,
 607                           round_jiffies(jiffies + interval));
 608         }
 609 }
 610
 611 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 612                                         struct ieee80211_mgmt *mgmt,
 613                                         size_t len)
 614 {
 615         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 616         struct ieee80211_local *local = sdata->local;
 617         int tx_last_beacon;
 618         struct sk_buff *skb;
 619         struct ieee80211_mgmt *resp;
 620         u8 *pos, *end;
 621
 622         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 623             len < 24 + 2 || !ifibss->presp)
 624                 return;
 625
 626         tx_last_beacon = drv_tx_last_beacon(local);
 627
 628 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 629         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 630                " (tx_last_beacon=%d)\n",
 631                sdata->name, mgmt->sa, mgmt->da,
 632                mgmt->bssid, tx_last_beacon);
 633 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 634
 635         if (!tx_last_beacon)
 636                 return;
 637
 638         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 639             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 640                 return;
 641
 642         end = ((u8 *) mgmt) + len;
 643         pos = mgmt->u.probe_req.variable;
 644         if (pos[0] != WLAN_EID_SSID ||
 645             pos + 2 + pos[1] > end) {
 646 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 647                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 648                        "from %pM\n",
 649                        sdata->name, mgmt->sa);
 650 #endif
 651                 return;
 652         }
 653         if (pos[1] != 0 &&
 654             (pos[1] != ifibss->ssid_len ||
 655              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 656                 /* Ignore ProbeReq for foreign SSID */
 657                 return;
 658         }
 659
 660         /* Reply with ProbeResp */
 661         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 662         if (!skb)
 663                 return;
 664
 665         resp = (struct ieee80211_mgmt *) skb->data;
 666         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 667 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 668         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 669                sdata->name, resp->da);
 670 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 671         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 672         ieee80211_tx_skb(sdata, skb);
 673 }
 674
 675 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 676                                          struct ieee80211_mgmt *mgmt,
 677                                          size_t len,
 678                                          struct ieee80211_rx_status *rx_status)
 679 {
 680         size_t baselen;
 681         struct ieee802_11_elems elems;
 682
 683         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 684                 return; /* ignore ProbeResp to foreign address */
 685
 686         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 687         if (baselen > len)
 688                 return;
 689
 690         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 691                                 &elems);
 692
 693         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 694 }
 695
 696 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 697                                      struct ieee80211_mgmt *mgmt,
 698                                      size_t len,
 699                                      struct ieee80211_rx_status *rx_status)
 700 {
 701         size_t baselen;
 702         struct ieee802_11_elems elems;
 703
 704         /* Process beacon from the current BSS */
 705         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 706         if (baselen > len)
 707                 return;
 708
 709         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 710
 711         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 712 }
 713
 714 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 715                                           struct sk_buff *skb)
 716 {
 717         struct ieee80211_rx_status *rx_status;
 718         struct ieee80211_mgmt *mgmt;
 719         u16 fc;
 720
 721         rx_status = IEEE80211_SKB_RXCB(skb);
 722         mgmt = (struct ieee80211_mgmt *) skb->data;
 723         fc = le16_to_cpu(mgmt->frame_control);
 724
 725         switch (fc & IEEE80211_FCTL_STYPE) {
 726         case IEEE80211_STYPE_PROBE_REQ:
 727                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 728                 break;
 729         case IEEE80211_STYPE_PROBE_RESP:
 730                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 731                                              rx_status);
 732                 break;
 733         case IEEE80211_STYPE_BEACON:
 734                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 735                                          rx_status);
 736                 break;
 737         case IEEE80211_STYPE_AUTH:
 738                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 739                 break;
 740         }
 741
 742         kfree_skb(skb);
 743 }
 744
 745 static void ieee80211_ibss_work(struct work_struct *work)
 746 {
 747         struct ieee80211_sub_if_data *sdata =
 748                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 749         struct ieee80211_local *local = sdata->local;
 750         struct ieee80211_if_ibss *ifibss;
 751         struct sk_buff *skb;
 752
 753         if (WARN_ON(local->suspended))
 754                 return;
 755
 756         if (!ieee80211_sdata_running(sdata))
 757                 return;
 758
 759         if (local->scanning)
 760                 return;
 761
 762         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 763                 return;
 764         ifibss = &sdata->u.ibss;
 765
 766         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 767                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 768
 769         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 770                 return;
 771
 772         switch (ifibss->state) {
 773         case IEEE80211_IBSS_MLME_SEARCH:
 774                 ieee80211_sta_find_ibss(sdata);
 775                 break;
 776         case IEEE80211_IBSS_MLME_JOINED:
 777                 ieee80211_sta_merge_ibss(sdata);
 778                 break;
 779         default:
 780                 WARN_ON(1);
 781                 break;
 782         }
 783 }
 784
 785 static void ieee80211_ibss_timer(unsigned long data)
 786 {
 787         struct ieee80211_sub_if_data *sdata =
 788                 (struct ieee80211_sub_if_data *) data;
 789         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 790         struct ieee80211_local *local = sdata->local;
 791
 792         if (local->quiescing) {
 793                 ifibss->timer_running = true;
 794                 return;
 795         }
 796
 797         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 798         ieee80211_queue_work(&local->hw, &ifibss->work);
 799 }
 800
 801 #ifdef CONFIG_PM
 802 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 803 {
 804         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 805
 806         cancel_work_sync(&ifibss->work);
 807         if (del_timer_sync(&ifibss->timer))
 808                 ifibss->timer_running = true;
 809 }
 810
 811 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 812 {
 813         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 814
 815         if (ifibss->timer_running) {
 816                 add_timer(&ifibss->timer);
 817                 ifibss->timer_running = false;
 818         }
 819 }
 820 #endif
 821
 822 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 823 {
 824         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 825
 826         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 827         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 828                     (unsigned long) sdata);
 829         skb_queue_head_init(&ifibss->skb_queue);
 830 }
 831
 832 /* scan finished notification */
 833 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 834 {
 835         struct ieee80211_sub_if_data *sdata;
 836
 837         mutex_lock(&local->iflist_mtx);
 838         list_for_each_entry(sdata, &local->interfaces, list) {
 839                 if (!ieee80211_sdata_running(sdata))
 840                         continue;
 841                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 842                         continue;
 843                 if (!sdata->u.ibss.ssid_len)
 844                         continue;
 845                 sdata->u.ibss.last_scan_completed = jiffies;
 846                 mod_timer(&sdata->u.ibss.timer, 0);
 847         }
 848         mutex_unlock(&local->iflist_mtx);
 849 }
 850
 851 ieee80211_rx_result
 852 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 853 {
 854         struct ieee80211_local *local = sdata->local;
 855         struct ieee80211_mgmt *mgmt;
 856         u16 fc;
 857
 858         if (skb->len < 24)
 859                 return RX_DROP_MONITOR;
 860
 861         mgmt = (struct ieee80211_mgmt *) skb->data;
 862         fc = le16_to_cpu(mgmt->frame_control);
 863
 864         switch (fc & IEEE80211_FCTL_STYPE) {
 865         case IEEE80211_STYPE_PROBE_RESP:
 866         case IEEE80211_STYPE_BEACON:
 867         case IEEE80211_STYPE_PROBE_REQ:
 868         case IEEE80211_STYPE_AUTH:
 869                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 870                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 871                 return RX_QUEUED;
 872         }
 873
 874         return RX_DROP_MONITOR;
 875 }
 876
 877 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 878                         struct cfg80211_ibss_params *params)
 879 {
 880         struct sk_buff *skb;
 881
 882         if (params->bssid) {
 883                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 884                 sdata->u.ibss.fixed_bssid = true;
 885         } else
 886                 sdata->u.ibss.fixed_bssid = false;
 887
 888         sdata->u.ibss.privacy = params->privacy;
 889
 890         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 891
 892         sdata->u.ibss.channel = params->channel;
 893         sdata->u.ibss.fixed_channel = params->channel_fixed;
 894
 895         if (params->ie) {
 896                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 897                                            GFP_KERNEL);
 898                 if (sdata->u.ibss.ie)
 899                         sdata->u.ibss.ie_len = params->ie_len;
 900         }
 901
 902         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 903                             36 /* bitrates */ +
 904                             34 /* SSID */ +
 905                             3  /* DS params */ +
 906                             4  /* IBSS params */ +
 907                             params->ie_len);
 908         if (!skb)
 909                 return -ENOMEM;
 910
 911         sdata->u.ibss.skb = skb;
 912         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 913         sdata->u.ibss.ibss_join_req = jiffies;
 914
 915         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 916
 917         /*
 918          * The ssid_len setting below is used to see whether
 919          * we are active, and we need all other settings
 920          * before that may get visible.
 921          */
 922         mb();
 923
 924         sdata->u.ibss.ssid_len = params->ssid_len;
 925
 926         ieee80211_recalc_idle(sdata->local);
 927
 928         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 929         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 930
 931         return 0;
 932 }
 933
 934 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 935 {
 936         struct sk_buff *skb;
 937
 938         del_timer_sync(&sdata->u.ibss.timer);
 939         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 940         cancel_work_sync(&sdata->u.ibss.work);
 941         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 942
 943         sta_info_flush(sdata->local, sdata);
 944
 945         /* remove beacon */
 946         kfree(sdata->u.ibss.ie);
 947         skb = sdata->u.ibss.presp;
 948         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 949         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 950         synchronize_rcu();
 951         kfree_skb(skb);
 952
 953         skb_queue_purge(&sdata->u.ibss.skb_queue);
 954         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 955         sdata->u.ibss.ssid_len = 0;
 956
 957         ieee80211_recalc_idle(sdata->local);
 958
 959         return 0;
 960 }