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