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