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