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         bss_change |= BSS_CHANGED_IBSS;
 174         sdata->vif.bss_conf.ibss_joined = true;
 175         ieee80211_bss_info_change_notify(sdata, bss_change);
 176
 177         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 178
 179         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 180         mod_timer(&ifibss->timer,
 181                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 182
 183         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 184                                         mgmt, skb->len, 0, GFP_KERNEL);
 185         cfg80211_put_bss(bss);
 186         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 187 }
 188
 189 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 190                                     struct ieee80211_bss *bss)
 191 {
 192         struct cfg80211_bss *cbss =
 193                 container_of((void *)bss, struct cfg80211_bss, priv);
 194         struct ieee80211_supported_band *sband;
 195         u32 basic_rates;
 196         int i, j;
 197         u16 beacon_int = cbss->beacon_interval;
 198
 199         if (beacon_int < 10)
 200                 beacon_int = 10;
 201
 202         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 203
 204         basic_rates = 0;
 205
 206         for (i = 0; i < bss->supp_rates_len; i++) {
 207                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 208                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 209
 210                 for (j = 0; j < sband->n_bitrates; j++) {
 211                         if (sband->bitrates[j].bitrate == rate) {
 212                                 if (is_basic)
 213                                         basic_rates |= BIT(j);
 214                                 break;
 215                         }
 216                 }
 217         }
 218
 219         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 220                                   beacon_int,
 221                                   cbss->channel,
 222                                   basic_rates,
 223                                   cbss->capability,
 224                                   cbss->tsf);
 225 }
 226
 227 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 228                                   struct ieee80211_mgmt *mgmt,
 229                                   size_t len,
 230                                   struct ieee80211_rx_status *rx_status,
 231                                   struct ieee802_11_elems *elems,
 232                                   bool beacon)
 233 {
 234         struct ieee80211_local *local = sdata->local;
 235         int freq;
 236         struct cfg80211_bss *cbss;
 237         struct ieee80211_bss *bss;
 238         struct sta_info *sta;
 239         struct ieee80211_channel *channel;
 240         u64 beacon_timestamp, rx_timestamp;
 241         u32 supp_rates = 0;
 242         enum ieee80211_band band = rx_status->band;
 243
 244         if (elems->ds_params && elems->ds_params_len == 1)
 245                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 246         else
 247                 freq = rx_status->freq;
 248
 249         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 250
 251         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 252                 return;
 253
 254         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 255             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 256                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 257
 258                 rcu_read_lock();
 259
 260                 sta = sta_info_get(sdata, mgmt->sa);
 261                 if (sta) {
 262                         u32 prev_rates;
 263
 264                         prev_rates = sta->sta.supp_rates[band];
 265                         /* make sure mandatory rates are always added */
 266                         sta->sta.supp_rates[band] = supp_rates |
 267                                 ieee80211_mandatory_rates(local, band);
 268
 269                         if (sta->sta.supp_rates[band] != prev_rates) {
 270 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 271                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 272                                     "for %pM based on beacon/probe_response "
 273                                     "(0x%x -> 0x%x)\n",
 274                                     sdata->name, sta->sta.addr,
 275                                     prev_rates, sta->sta.supp_rates[band]);
 276 #endif
 277                                 rate_control_rate_init(sta);
 278                         }
 279                         rcu_read_unlock();
 280                 } else {
 281                         rcu_read_unlock();
 282                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 283                                                supp_rates, GFP_KERNEL);
 284                 }
 285         }
 286
 287         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 288                                         channel, beacon);
 289         if (!bss)
 290                 return;
 291
 292         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 293
 294         /* was just updated in ieee80211_bss_info_update */
 295         beacon_timestamp = cbss->tsf;
 296
 297         /* check if we need to merge IBSS */
 298
 299         /* we use a fixed BSSID */
 300         if (sdata->u.ibss.fixed_bssid)
 301                 goto put_bss;
 302
 303         /* not an IBSS */
 304         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 305                 goto put_bss;
 306
 307         /* different channel */
 308         if (cbss->channel != local->oper_channel)
 309                 goto put_bss;
 310
 311         /* different SSID */
 312         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 313             memcmp(elems->ssid, sdata->u.ibss.ssid,
 314                                 sdata->u.ibss.ssid_len))
 315                 goto put_bss;
 316
 317         /* same BSSID */
 318         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 319                 goto put_bss;
 320
 321         if (rx_status->flag & RX_FLAG_TSFT) {
 322                 /*
 323                  * For correct IBSS merging we need mactime; since mactime is
 324                  * defined as the time the first data symbol of the frame hits
 325                  * the PHY, and the timestamp of the beacon is defined as "the
 326                  * time that the data symbol containing the first bit of the
 327                  * timestamp is transmitted to the PHY plus the transmitting
 328                  * STA's delays through its local PHY from the MAC-PHY
 329                  * interface to its interface with the WM" (802.11 11.1.2)
 330                  * - equals the time this bit arrives at the receiver - we have
 331                  * to take into account the offset between the two.
 332                  *
 333                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 334                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 335                  */
 336                 int rate;
 337
 338                 if (rx_status->flag & RX_FLAG_HT)
 339                         rate = 65; /* TODO: HT rates */
 340                 else
 341                         rate = local->hw.wiphy->bands[band]->
 342                                 bitrates[rx_status->rate_idx].bitrate;
 343
 344                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 345         } else {
 346                 /*
 347                  * second best option: get current TSF
 348                  * (will return -1 if not supported)
 349                  */
 350                 rx_timestamp = drv_get_tsf(local);
 351         }
 352
 353 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 354         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 355                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 356                mgmt->sa, mgmt->bssid,
 357                (unsigned long long)rx_timestamp,
 358                (unsigned long long)beacon_timestamp,
 359                (unsigned long long)(rx_timestamp - beacon_timestamp),
 360                jiffies);
 361 #endif
 362
 363         /* give slow hardware some time to do the TSF sync */
 364         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 365                 goto put_bss;
 366
 367         if (beacon_timestamp > rx_timestamp) {
 368 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 369                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 370                        "local TSF - IBSS merge with BSSID %pM\n",
 371                        sdata->name, mgmt->bssid);
 372 #endif
 373                 ieee80211_sta_join_ibss(sdata, bss);
 374                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 375                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 376                                        supp_rates, GFP_KERNEL);
 377         }
 378
 379  put_bss:
 380         ieee80211_rx_bss_put(local, bss);
 381 }
 382
 383 /*
 384  * Add a new IBSS station, will also be called by the RX code when,
 385  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 386  * must be callable in atomic context.
 387  */
 388 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 389                                         u8 *bssid,u8 *addr, u32 supp_rates,
 390                                         gfp_t gfp)
 391 {
 392         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 393         struct ieee80211_local *local = sdata->local;
 394         struct sta_info *sta;
 395         int band = local->hw.conf.channel->band;
 396
 397         /*
 398          * XXX: Consider removing the least recently used entry and
 399          *      allow new one to be added.
 400          */
 401         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 402                 if (net_ratelimit())
 403                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 404                                sdata->name, addr);
 405                 return NULL;
 406         }
 407
 408         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 409                 return NULL;
 410
 411         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 412                 return NULL;
 413
 414 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 415         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 416                wiphy_name(local->hw.wiphy), addr, sdata->name);
 417 #endif
 418
 419         sta = sta_info_alloc(sdata, addr, gfp);
 420         if (!sta)
 421                 return NULL;
 422
 423         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 424
 425         /* make sure mandatory rates are always added */
 426         sta->sta.supp_rates[band] = supp_rates |
 427                         ieee80211_mandatory_rates(local, band);
 428
 429         rate_control_rate_init(sta);
 430
 431         /* If it fails, maybe we raced another insertion? */
 432         if (sta_info_insert(sta))
 433                 return sta_info_get(sdata, addr);
 434         return sta;
 435 }
 436
 437 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 438 {
 439         struct ieee80211_local *local = sdata->local;
 440         int active = 0;
 441         struct sta_info *sta;
 442
 443         rcu_read_lock();
 444
 445         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 446                 if (sta->sdata == sdata &&
 447                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 448                                jiffies)) {
 449                         active++;
 450                         break;
 451                 }
 452         }
 453
 454         rcu_read_unlock();
 455
 456         return active;
 457 }
 458
 459 /*
 460  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 461  */
 462
 463 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 464 {
 465         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 466
 467         mod_timer(&ifibss->timer,
 468                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 469
 470         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 471
 472         if (time_before(jiffies, ifibss->last_scan_completed +
 473                        IEEE80211_IBSS_MERGE_INTERVAL))
 474                 return;
 475
 476         if (ieee80211_sta_active_ibss(sdata))
 477                 return;
 478
 479         if (ifibss->fixed_channel)
 480                 return;
 481
 482         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 483                "IBSS networks with same SSID (merge)\n", sdata->name);
 484
 485         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 486 }
 487
 488 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 489 {
 490         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 491         struct ieee80211_local *local = sdata->local;
 492         struct ieee80211_supported_band *sband;
 493         u8 bssid[ETH_ALEN];
 494         u16 capability;
 495         int i;
 496
 497         if (ifibss->fixed_bssid) {
 498                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 499         } else {
 500                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 501                  * own MAC address to make sure that devices that do not have proper
 502                  * random number generator get different BSSID. */
 503                 get_random_bytes(bssid, ETH_ALEN);
 504                 for (i = 0; i < ETH_ALEN; i++)
 505                         bssid[i] ^= sdata->vif.addr[i];
 506                 bssid[0] &= ~0x01;
 507                 bssid[0] |= 0x02;
 508         }
 509
 510         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 511                sdata->name, bssid);
 512
 513         sband = local->hw.wiphy->bands[ifibss->channel->band];
 514
 515         capability = WLAN_CAPABILITY_IBSS;
 516
 517         if (ifibss->privacy)
 518                 capability |= WLAN_CAPABILITY_PRIVACY;
 519         else
 520                 sdata->drop_unencrypted = 0;
 521
 522         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 523                                   ifibss->channel, 3, /* first two are basic */
 524                                   capability, 0);
 525 }
 526
 527 /*
 528  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 529  */
 530
 531 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 532 {
 533         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 534         struct ieee80211_local *local = sdata->local;
 535         struct cfg80211_bss *cbss;
 536         struct ieee80211_channel *chan = NULL;
 537         const u8 *bssid = NULL;
 538         int active_ibss;
 539         u16 capability;
 540
 541         active_ibss = ieee80211_sta_active_ibss(sdata);
 542 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 543         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 544                sdata->name, active_ibss);
 545 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 546
 547         if (active_ibss)
 548                 return;
 549
 550         capability = WLAN_CAPABILITY_IBSS;
 551         if (ifibss->privacy)
 552                 capability |= WLAN_CAPABILITY_PRIVACY;
 553         if (ifibss->fixed_bssid)
 554                 bssid = ifibss->bssid;
 555         if (ifibss->fixed_channel)
 556                 chan = ifibss->channel;
 557         if (!is_zero_ether_addr(ifibss->bssid))
 558                 bssid = ifibss->bssid;
 559         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 560                                 ifibss->ssid, ifibss->ssid_len,
 561                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 562                                 capability);
 563
 564         if (cbss) {
 565                 struct ieee80211_bss *bss;
 566
 567                 bss = (void *)cbss->priv;
 568 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 569                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 570                        "%pM\n", cbss->bssid, ifibss->bssid);
 571 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 572
 573                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 574                        " based on configured SSID\n",
 575                        sdata->name, cbss->bssid);
 576
 577                 ieee80211_sta_join_ibss(sdata, bss);
 578                 ieee80211_rx_bss_put(local, bss);
 579                 return;
 580         }
 581
 582 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 583         printk(KERN_DEBUG "   did not try to join ibss\n");
 584 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 585
 586         /* Selected IBSS not found in current scan results - try to scan */
 587         if (time_after(jiffies, ifibss->last_scan_completed +
 588                                         IEEE80211_SCAN_INTERVAL)) {
 589                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 590                        "join\n", sdata->name);
 591
 592                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 593                                                 ifibss->ssid_len);
 594         } else {
 595                 int interval = IEEE80211_SCAN_INTERVAL;
 596
 597                 if (time_after(jiffies, ifibss->ibss_join_req +
 598                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 599                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 600                                 ieee80211_sta_create_ibss(sdata);
 601                                 return;
 602                         }
 603                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 604                                " %d MHz\n", sdata->name,
 605                                local->hw.conf.channel->center_freq);
 606
 607                         /* No IBSS found - decrease scan interval and continue
 608                          * scanning. */
 609                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 610                 }
 611
 612                 mod_timer(&ifibss->timer,
 613                           round_jiffies(jiffies + interval));
 614         }
 615 }
 616
 617 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 618                                         struct ieee80211_mgmt *mgmt,
 619                                         size_t len)
 620 {
 621         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 622         struct ieee80211_local *local = sdata->local;
 623         int tx_last_beacon;
 624         struct sk_buff *skb;
 625         struct ieee80211_mgmt *resp;
 626         u8 *pos, *end;
 627
 628         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 629             len < 24 + 2 || !ifibss->presp)
 630                 return;
 631
 632         tx_last_beacon = drv_tx_last_beacon(local);
 633
 634 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 635         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 636                " (tx_last_beacon=%d)\n",
 637                sdata->name, mgmt->sa, mgmt->da,
 638                mgmt->bssid, tx_last_beacon);
 639 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 640
 641         if (!tx_last_beacon)
 642                 return;
 643
 644         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 645             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 646                 return;
 647
 648         end = ((u8 *) mgmt) + len;
 649         pos = mgmt->u.probe_req.variable;
 650         if (pos[0] != WLAN_EID_SSID ||
 651             pos + 2 + pos[1] > end) {
 652 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 653                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 654                        "from %pM\n",
 655                        sdata->name, mgmt->sa);
 656 #endif
 657                 return;
 658         }
 659         if (pos[1] != 0 &&
 660             (pos[1] != ifibss->ssid_len ||
 661              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 662                 /* Ignore ProbeReq for foreign SSID */
 663                 return;
 664         }
 665
 666         /* Reply with ProbeResp */
 667         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 668         if (!skb)
 669                 return;
 670
 671         resp = (struct ieee80211_mgmt *) skb->data;
 672         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 673 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 674         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 675                sdata->name, resp->da);
 676 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 677         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 678         ieee80211_tx_skb(sdata, skb);
 679 }
 680
 681 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 682                                          struct ieee80211_mgmt *mgmt,
 683                                          size_t len,
 684                                          struct ieee80211_rx_status *rx_status)
 685 {
 686         size_t baselen;
 687         struct ieee802_11_elems elems;
 688
 689         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 690                 return; /* ignore ProbeResp to foreign address */
 691
 692         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 693         if (baselen > len)
 694                 return;
 695
 696         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 697                                 &elems);
 698
 699         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 700 }
 701
 702 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 703                                      struct ieee80211_mgmt *mgmt,
 704                                      size_t len,
 705                                      struct ieee80211_rx_status *rx_status)
 706 {
 707         size_t baselen;
 708         struct ieee802_11_elems elems;
 709
 710         /* Process beacon from the current BSS */
 711         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 712         if (baselen > len)
 713                 return;
 714
 715         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 716
 717         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 718 }
 719
 720 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 721                                           struct sk_buff *skb)
 722 {
 723         struct ieee80211_rx_status *rx_status;
 724         struct ieee80211_mgmt *mgmt;
 725         u16 fc;
 726
 727         rx_status = IEEE80211_SKB_RXCB(skb);
 728         mgmt = (struct ieee80211_mgmt *) skb->data;
 729         fc = le16_to_cpu(mgmt->frame_control);
 730
 731         switch (fc & IEEE80211_FCTL_STYPE) {
 732         case IEEE80211_STYPE_PROBE_REQ:
 733                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 734                 break;
 735         case IEEE80211_STYPE_PROBE_RESP:
 736                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 737                                              rx_status);
 738                 break;
 739         case IEEE80211_STYPE_BEACON:
 740                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 741                                          rx_status);
 742                 break;
 743         case IEEE80211_STYPE_AUTH:
 744                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 745                 break;
 746         }
 747
 748         kfree_skb(skb);
 749 }
 750
 751 static void ieee80211_ibss_work(struct work_struct *work)
 752 {
 753         struct ieee80211_sub_if_data *sdata =
 754                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 755         struct ieee80211_local *local = sdata->local;
 756         struct ieee80211_if_ibss *ifibss;
 757         struct sk_buff *skb;
 758
 759         if (WARN_ON(local->suspended))
 760                 return;
 761
 762         if (!ieee80211_sdata_running(sdata))
 763                 return;
 764
 765         if (local->scanning)
 766                 return;
 767
 768         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 769                 return;
 770         ifibss = &sdata->u.ibss;
 771
 772         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 773                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 774
 775         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 776                 return;
 777
 778         switch (ifibss->state) {
 779         case IEEE80211_IBSS_MLME_SEARCH:
 780                 ieee80211_sta_find_ibss(sdata);
 781                 break;
 782         case IEEE80211_IBSS_MLME_JOINED:
 783                 ieee80211_sta_merge_ibss(sdata);
 784                 break;
 785         default:
 786                 WARN_ON(1);
 787                 break;
 788         }
 789 }
 790
 791 static void ieee80211_ibss_timer(unsigned long data)
 792 {
 793         struct ieee80211_sub_if_data *sdata =
 794                 (struct ieee80211_sub_if_data *) data;
 795         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 796         struct ieee80211_local *local = sdata->local;
 797
 798         if (local->quiescing) {
 799                 ifibss->timer_running = true;
 800                 return;
 801         }
 802
 803         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 804         ieee80211_queue_work(&local->hw, &ifibss->work);
 805 }
 806
 807 #ifdef CONFIG_PM
 808 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 809 {
 810         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 811
 812         cancel_work_sync(&ifibss->work);
 813         if (del_timer_sync(&ifibss->timer))
 814                 ifibss->timer_running = true;
 815 }
 816
 817 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 818 {
 819         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 820
 821         if (ifibss->timer_running) {
 822                 add_timer(&ifibss->timer);
 823                 ifibss->timer_running = false;
 824         }
 825 }
 826 #endif
 827
 828 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 829 {
 830         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 831
 832         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 833         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 834                     (unsigned long) sdata);
 835         skb_queue_head_init(&ifibss->skb_queue);
 836 }
 837
 838 /* scan finished notification */
 839 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 840 {
 841         struct ieee80211_sub_if_data *sdata;
 842
 843         mutex_lock(&local->iflist_mtx);
 844         list_for_each_entry(sdata, &local->interfaces, list) {
 845                 if (!ieee80211_sdata_running(sdata))
 846                         continue;
 847                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 848                         continue;
 849                 if (!sdata->u.ibss.ssid_len)
 850                         continue;
 851                 sdata->u.ibss.last_scan_completed = jiffies;
 852                 mod_timer(&sdata->u.ibss.timer, 0);
 853         }
 854         mutex_unlock(&local->iflist_mtx);
 855 }
 856
 857 ieee80211_rx_result
 858 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 859 {
 860         struct ieee80211_local *local = sdata->local;
 861         struct ieee80211_mgmt *mgmt;
 862         u16 fc;
 863
 864         if (skb->len < 24)
 865                 return RX_DROP_MONITOR;
 866
 867         mgmt = (struct ieee80211_mgmt *) skb->data;
 868         fc = le16_to_cpu(mgmt->frame_control);
 869
 870         switch (fc & IEEE80211_FCTL_STYPE) {
 871         case IEEE80211_STYPE_PROBE_RESP:
 872         case IEEE80211_STYPE_BEACON:
 873         case IEEE80211_STYPE_PROBE_REQ:
 874         case IEEE80211_STYPE_AUTH:
 875                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 876                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 877                 return RX_QUEUED;
 878         }
 879
 880         return RX_DROP_MONITOR;
 881 }
 882
 883 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 884                         struct cfg80211_ibss_params *params)
 885 {
 886         struct sk_buff *skb;
 887
 888         if (params->bssid) {
 889                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 890                 sdata->u.ibss.fixed_bssid = true;
 891         } else
 892                 sdata->u.ibss.fixed_bssid = false;
 893
 894         sdata->u.ibss.privacy = params->privacy;
 895
 896         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 897
 898         sdata->u.ibss.channel = params->channel;
 899         sdata->u.ibss.fixed_channel = params->channel_fixed;
 900
 901         if (params->ie) {
 902                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 903                                            GFP_KERNEL);
 904                 if (sdata->u.ibss.ie)
 905                         sdata->u.ibss.ie_len = params->ie_len;
 906         }
 907
 908         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 909                             36 /* bitrates */ +
 910                             34 /* SSID */ +
 911                             3  /* DS params */ +
 912                             4  /* IBSS params */ +
 913                             params->ie_len);
 914         if (!skb)
 915                 return -ENOMEM;
 916
 917         sdata->u.ibss.skb = skb;
 918         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 919         sdata->u.ibss.ibss_join_req = jiffies;
 920
 921         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 922
 923         /*
 924          * The ssid_len setting below is used to see whether
 925          * we are active, and we need all other settings
 926          * before that may get visible.
 927          */
 928         mb();
 929
 930         sdata->u.ibss.ssid_len = params->ssid_len;
 931
 932         ieee80211_recalc_idle(sdata->local);
 933
 934         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 935         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 936
 937         return 0;
 938 }
 939
 940 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 941 {
 942         struct sk_buff *skb;
 943
 944         del_timer_sync(&sdata->u.ibss.timer);
 945         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 946         cancel_work_sync(&sdata->u.ibss.work);
 947         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 948
 949         sta_info_flush(sdata->local, sdata);
 950
 951         /* remove beacon */
 952         kfree(sdata->u.ibss.ie);
 953         skb = sdata->u.ibss.presp;
 954         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 955         sdata->vif.bss_conf.ibss_joined = false;
 956         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
 957                                                 BSS_CHANGED_IBSS);
 958         synchronize_rcu();
 959         kfree_skb(skb);
 960
 961         skb_queue_purge(&sdata->u.ibss.skb_queue);
 962         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 963         sdata->u.ibss.ssid_len = 0;
 964
 965         ieee80211_recalc_idle(sdata->local);
 966
 967         return 0;
 968 }