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