net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/mac80211.h>
  22 #include <asm/unaligned.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "rate.h"
  27
  28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  29 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  31
  32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  33 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  35
  36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  37
  38
  39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  40                                         struct ieee80211_mgmt *mgmt,
  41                                         size_t len)
  42 {
  43         u16 auth_alg, auth_transaction, status_code;
  44
  45         if (len < 24 + 6)
  46                 return;
  47
  48         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  49         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  50         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  51
  52         /*
  53          * IEEE 802.11 standard does not require authentication in IBSS
  54          * networks and most implementations do not seem to use it.
  55          * However, try to reply to authentication attempts if someone
  56          * has actually implemented this.
  57          */
  58         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  59                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  60                                     sdata->u.ibss.bssid, NULL, 0, 0);
  61 }
  62
  63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  64                                       const u8 *bssid, const int beacon_int,
  65                                       struct ieee80211_channel *chan,
  66                                       const u32 basic_rates,
  67                                       const u16 capability, u64 tsf)
  68 {
  69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  70         struct ieee80211_local *local = sdata->local;
  71         int rates, i;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76         struct cfg80211_bss *bss;
  77         u32 bss_change;
  78         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  79
  80         /* Reset own TSF to allow time synchronization work. */
  81         drv_reset_tsf(local);
  82
  83         skb = ifibss->skb;
  84         rcu_assign_pointer(ifibss->presp, NULL);
  85         synchronize_rcu();
  86         skb->data = skb->head;
  87         skb->len = 0;
  88         skb_reset_tail_pointer(skb);
  89         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  90
  91         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  92                 sta_info_flush(sdata->local, sdata);
  93
  94         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  95
  96         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  97
  98         local->oper_channel = chan;
  99         local->oper_channel_type = NL80211_CHAN_NO_HT;
 100         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 101
 102         sband = local->hw.wiphy->bands[chan->band];
 103
 104         /* build supported rates array */
 105         pos = supp_rates;
 106         for (i = 0; i < sband->n_bitrates; i++) {
 107                 int rate = sband->bitrates[i].bitrate;
 108                 u8 basic = 0;
 109                 if (basic_rates & BIT(i))
 110                         basic = 0x80;
 111                 *pos++ = basic | (u8) (rate / 5);
 112         }
 113
 114         /* Build IBSS probe response */
 115         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 116         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 117         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 118                                           IEEE80211_STYPE_PROBE_RESP);
 119         memset(mgmt->da, 0xff, ETH_ALEN);
 120         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 121         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 122         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 123         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 124         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 125
 126         pos = skb_put(skb, 2 + ifibss->ssid_len);
 127         *pos++ = WLAN_EID_SSID;
 128         *pos++ = ifibss->ssid_len;
 129         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 130
 131         rates = sband->n_bitrates;
 132         if (rates > 8)
 133                 rates = 8;
 134         pos = skb_put(skb, 2 + rates);
 135         *pos++ = WLAN_EID_SUPP_RATES;
 136         *pos++ = rates;
 137         memcpy(pos, supp_rates, rates);
 138
 139         if (sband->band == IEEE80211_BAND_2GHZ) {
 140                 pos = skb_put(skb, 2 + 1);
 141                 *pos++ = WLAN_EID_DS_PARAMS;
 142                 *pos++ = 1;
 143                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 144         }
 145
 146         pos = skb_put(skb, 2 + 2);
 147         *pos++ = WLAN_EID_IBSS_PARAMS;
 148         *pos++ = 2;
 149         /* FIX: set ATIM window based on scan results */
 150         *pos++ = 0;
 151         *pos++ = 0;
 152
 153         if (sband->n_bitrates > 8) {
 154                 rates = sband->n_bitrates - 8;
 155                 pos = skb_put(skb, 2 + rates);
 156                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 157                 *pos++ = rates;
 158                 memcpy(pos, &supp_rates[8], rates);
 159         }
 160
 161         if (ifibss->ie_len)
 162                 memcpy(skb_put(skb, ifibss->ie_len),
 163                        ifibss->ie, ifibss->ie_len);
 164
 165         rcu_assign_pointer(ifibss->presp, skb);
 166
 167         sdata->vif.bss_conf.beacon_int = beacon_int;
 168         bss_change = BSS_CHANGED_BEACON_INT;
 169         bss_change |= ieee80211_reset_erp_info(sdata);
 170         bss_change |= BSS_CHANGED_BSSID;
 171         bss_change |= BSS_CHANGED_BEACON;
 172         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 173         ieee80211_bss_info_change_notify(sdata, bss_change);
 174
 175         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 176
 177         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 178         mod_timer(&ifibss->timer,
 179                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 180
 181         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 182                                         mgmt, skb->len, 0, GFP_KERNEL);
 183         cfg80211_put_bss(bss);
 184         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 185 }
 186
 187 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 188                                     struct ieee80211_bss *bss)
 189 {
 190         struct cfg80211_bss *cbss =
 191                 container_of((void *)bss, struct cfg80211_bss, priv);
 192         struct ieee80211_supported_band *sband;
 193         u32 basic_rates;
 194         int i, j;
 195         u16 beacon_int = cbss->beacon_interval;
 196
 197         if (beacon_int < 10)
 198                 beacon_int = 10;
 199
 200         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 201
 202         basic_rates = 0;
 203
 204         for (i = 0; i < bss->supp_rates_len; i++) {
 205                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 206                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 207
 208                 for (j = 0; j < sband->n_bitrates; j++) {
 209                         if (sband->bitrates[j].bitrate == rate) {
 210                                 if (is_basic)
 211                                         basic_rates |= BIT(j);
 212                                 break;
 213                         }
 214                 }
 215         }
 216
 217         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 218                                   beacon_int,
 219                                   cbss->channel,
 220                                   basic_rates,
 221                                   cbss->capability,
 222                                   cbss->tsf);
 223 }
 224
 225 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 226                                   struct ieee80211_mgmt *mgmt,
 227                                   size_t len,
 228                                   struct ieee80211_rx_status *rx_status,
 229                                   struct ieee802_11_elems *elems,
 230                                   bool beacon)
 231 {
 232         struct ieee80211_local *local = sdata->local;
 233         int freq;
 234         struct cfg80211_bss *cbss;
 235         struct ieee80211_bss *bss;
 236         struct sta_info *sta;
 237         struct ieee80211_channel *channel;
 238         u64 beacon_timestamp, rx_timestamp;
 239         u32 supp_rates = 0;
 240         enum ieee80211_band band = rx_status->band;
 241
 242         if (elems->ds_params && elems->ds_params_len == 1)
 243                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 244         else
 245                 freq = rx_status->freq;
 246
 247         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 248
 249         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 250                 return;
 251
 252         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 253             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 254                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 255
 256                 rcu_read_lock();
 257
 258                 sta = sta_info_get(sdata, mgmt->sa);
 259                 if (sta) {
 260                         u32 prev_rates;
 261
 262                         prev_rates = sta->sta.supp_rates[band];
 263                         /* make sure mandatory rates are always added */
 264                         sta->sta.supp_rates[band] = supp_rates |
 265                                 ieee80211_mandatory_rates(local, band);
 266
 267 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 268                         if (sta->sta.supp_rates[band] != prev_rates)
 269                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 270                                     "for %pM based on beacon info (0x%llx | "
 271                                     "0x%llx -> 0x%llx)\n",
 272                                     sdata->name,
 273                                     sta->sta.addr,
 274                                     (unsigned long long) prev_rates,
 275                                     (unsigned long long) supp_rates,
 276                                     (unsigned long long) sta->sta.supp_rates[band]);
 277 #endif
 278                 } else
 279                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 280
 281                 rcu_read_unlock();
 282         }
 283
 284         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 285                                         channel, beacon);
 286         if (!bss)
 287                 return;
 288
 289         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 290
 291         /* was just updated in ieee80211_bss_info_update */
 292         beacon_timestamp = cbss->tsf;
 293
 294         /* check if we need to merge IBSS */
 295
 296         /* merge only on beacons (???) */
 297         if (!beacon)
 298                 goto put_bss;
 299
 300         /* we use a fixed BSSID */
 301         if (sdata->u.ibss.bssid)
 302                 goto put_bss;
 303
 304         /* not an IBSS */
 305         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 306                 goto put_bss;
 307
 308         /* different channel */
 309         if (cbss->channel != local->oper_channel)
 310                 goto put_bss;
 311
 312         /* different SSID */
 313         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 314             memcmp(elems->ssid, sdata->u.ibss.ssid,
 315                                 sdata->u.ibss.ssid_len))
 316                 goto put_bss;
 317
 318         /* same BSSID */
 319         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 320                 goto put_bss;
 321
 322         if (rx_status->flag & RX_FLAG_TSFT) {
 323                 /*
 324                  * For correct IBSS merging we need mactime; since mactime is
 325                  * defined as the time the first data symbol of the frame hits
 326                  * the PHY, and the timestamp of the beacon is defined as "the
 327                  * time that the data symbol containing the first bit of the
 328                  * timestamp is transmitted to the PHY plus the transmitting
 329                  * STA's delays through its local PHY from the MAC-PHY
 330                  * interface to its interface with the WM" (802.11 11.1.2)
 331                  * - equals the time this bit arrives at the receiver - we have
 332                  * to take into account the offset between the two.
 333                  *
 334                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 335                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 336                  */
 337                 int rate;
 338
 339                 if (rx_status->flag & RX_FLAG_HT)
 340                         rate = 65; /* TODO: HT rates */
 341                 else
 342                         rate = local->hw.wiphy->bands[band]->
 343                                 bitrates[rx_status->rate_idx].bitrate;
 344
 345                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 346         } else {
 347                 /*
 348                  * second best option: get current TSF
 349                  * (will return -1 if not supported)
 350                  */
 351                 rx_timestamp = drv_get_tsf(local);
 352         }
 353
 354 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 355         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 356                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 357                mgmt->sa, mgmt->bssid,
 358                (unsigned long long)rx_timestamp,
 359                (unsigned long long)beacon_timestamp,
 360                (unsigned long long)(rx_timestamp - beacon_timestamp),
 361                jiffies);
 362 #endif
 363
 364         /* give slow hardware some time to do the TSF sync */
 365         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 366                 goto put_bss;
 367
 368         if (beacon_timestamp > rx_timestamp) {
 369 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 370                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 371                        "local TSF - IBSS merge with BSSID %pM\n",
 372                        sdata->name, mgmt->bssid);
 373 #endif
 374                 ieee80211_sta_join_ibss(sdata, bss);
 375                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 376         }
 377
 378  put_bss:
 379         ieee80211_rx_bss_put(local, bss);
 380 }
 381
 382 /*
 383  * Add a new IBSS station, will also be called by the RX code when,
 384  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 385  * must be callable in atomic context.
 386  */
 387 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 388                                         u8 *bssid,u8 *addr, u32 supp_rates)
 389 {
 390         struct ieee80211_local *local = sdata->local;
 391         struct sta_info *sta;
 392         int band = local->hw.conf.channel->band;
 393
 394         /*
 395          * XXX: Consider removing the least recently used entry and
 396          *      allow new one to be added.
 397          */
 398         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 399                 if (net_ratelimit())
 400                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 401                                sdata->name, addr);
 402                 return NULL;
 403         }
 404
 405         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 406                 return NULL;
 407
 408 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 409         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 410                wiphy_name(local->hw.wiphy), addr, sdata->name);
 411 #endif
 412
 413         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 414         if (!sta)
 415                 return NULL;
 416
 417         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 418
 419         /* make sure mandatory rates are always added */
 420         sta->sta.supp_rates[band] = supp_rates |
 421                         ieee80211_mandatory_rates(local, band);
 422
 423         rate_control_rate_init(sta);
 424
 425         if (sta_info_insert(sta))
 426                 return NULL;
 427
 428         return sta;
 429 }
 430
 431 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 432 {
 433         struct ieee80211_local *local = sdata->local;
 434         int active = 0;
 435         struct sta_info *sta;
 436
 437         rcu_read_lock();
 438
 439         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 440                 if (sta->sdata == sdata &&
 441                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 442                                jiffies)) {
 443                         active++;
 444                         break;
 445                 }
 446         }
 447
 448         rcu_read_unlock();
 449
 450         return active;
 451 }
 452
 453
 454 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 455 {
 456         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 457
 458         mod_timer(&ifibss->timer,
 459                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 460
 461         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 462
 463         if (time_before(jiffies, ifibss->last_scan_completed +
 464                        IEEE80211_IBSS_MERGE_INTERVAL))
 465                 return;
 466
 467         if (ieee80211_sta_active_ibss(sdata))
 468                 return;
 469
 470         if (ifibss->fixed_channel)
 471                 return;
 472
 473         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 474                "IBSS networks with same SSID (merge)\n", sdata->name);
 475
 476         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 477 }
 478
 479 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 480 {
 481         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 482         struct ieee80211_local *local = sdata->local;
 483         struct ieee80211_supported_band *sband;
 484         u8 bssid[ETH_ALEN];
 485         u16 capability;
 486         int i;
 487
 488         if (ifibss->fixed_bssid) {
 489                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 490         } else {
 491                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 492                  * own MAC address to make sure that devices that do not have proper
 493                  * random number generator get different BSSID. */
 494                 get_random_bytes(bssid, ETH_ALEN);
 495                 for (i = 0; i < ETH_ALEN; i++)
 496                         bssid[i] ^= sdata->vif.addr[i];
 497                 bssid[0] &= ~0x01;
 498                 bssid[0] |= 0x02;
 499         }
 500
 501         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 502                sdata->name, bssid);
 503
 504         sband = local->hw.wiphy->bands[ifibss->channel->band];
 505
 506         capability = WLAN_CAPABILITY_IBSS;
 507
 508         if (ifibss->privacy)
 509                 capability |= WLAN_CAPABILITY_PRIVACY;
 510         else
 511                 sdata->drop_unencrypted = 0;
 512
 513         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 514                                   ifibss->channel, 3, /* first two are basic */
 515                                   capability, 0);
 516 }
 517
 518 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 519 {
 520         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 521         struct ieee80211_local *local = sdata->local;
 522         struct cfg80211_bss *cbss;
 523         struct ieee80211_channel *chan = NULL;
 524         const u8 *bssid = NULL;
 525         int active_ibss;
 526         u16 capability;
 527
 528         active_ibss = ieee80211_sta_active_ibss(sdata);
 529 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 530         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 531                sdata->name, active_ibss);
 532 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 533
 534         if (active_ibss)
 535                 return;
 536
 537         capability = WLAN_CAPABILITY_IBSS;
 538         if (ifibss->privacy)
 539                 capability |= WLAN_CAPABILITY_PRIVACY;
 540         if (ifibss->fixed_bssid)
 541                 bssid = ifibss->bssid;
 542         if (ifibss->fixed_channel)
 543                 chan = ifibss->channel;
 544         if (!is_zero_ether_addr(ifibss->bssid))
 545                 bssid = ifibss->bssid;
 546         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 547                                 ifibss->ssid, ifibss->ssid_len,
 548                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 549                                 capability);
 550
 551         if (cbss) {
 552                 struct ieee80211_bss *bss;
 553
 554                 bss = (void *)cbss->priv;
 555 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 556                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 557                        "%pM\n", cbss->bssid, ifibss->bssid);
 558 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 559
 560                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 561                        " based on configured SSID\n",
 562                        sdata->name, cbss->bssid);
 563
 564                 ieee80211_sta_join_ibss(sdata, bss);
 565                 ieee80211_rx_bss_put(local, bss);
 566                 return;
 567         }
 568
 569 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 570         printk(KERN_DEBUG "   did not try to join ibss\n");
 571 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 572
 573         /* Selected IBSS not found in current scan results - try to scan */
 574         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 575             !ieee80211_sta_active_ibss(sdata)) {
 576                 mod_timer(&ifibss->timer,
 577                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 578         } else if (time_after(jiffies, ifibss->last_scan_completed +
 579                                         IEEE80211_SCAN_INTERVAL)) {
 580                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 581                        "join\n", sdata->name);
 582
 583                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 584                                                 ifibss->ssid_len);
 585         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 586                 int interval = IEEE80211_SCAN_INTERVAL;
 587
 588                 if (time_after(jiffies, ifibss->ibss_join_req +
 589                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 590                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 591                                 ieee80211_sta_create_ibss(sdata);
 592                                 return;
 593                         }
 594                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 595                                " %d MHz\n", sdata->name,
 596                                local->hw.conf.channel->center_freq);
 597
 598                         /* No IBSS found - decrease scan interval and continue
 599                          * scanning. */
 600                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 601                 }
 602
 603                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 604                 mod_timer(&ifibss->timer,
 605                           round_jiffies(jiffies + interval));
 606         }
 607 }
 608
 609 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 610                                         struct ieee80211_mgmt *mgmt,
 611                                         size_t len)
 612 {
 613         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 614         struct ieee80211_local *local = sdata->local;
 615         int tx_last_beacon;
 616         struct sk_buff *skb;
 617         struct ieee80211_mgmt *resp;
 618         u8 *pos, *end;
 619
 620         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 621             len < 24 + 2 || !ifibss->presp)
 622                 return;
 623
 624         tx_last_beacon = drv_tx_last_beacon(local);
 625
 626 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 627         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 628                " (tx_last_beacon=%d)\n",
 629                sdata->name, mgmt->sa, mgmt->da,
 630                mgmt->bssid, tx_last_beacon);
 631 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 632
 633         if (!tx_last_beacon)
 634                 return;
 635
 636         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 637             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 638                 return;
 639
 640         end = ((u8 *) mgmt) + len;
 641         pos = mgmt->u.probe_req.variable;
 642         if (pos[0] != WLAN_EID_SSID ||
 643             pos + 2 + pos[1] > end) {
 644 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 645                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 646                        "from %pM\n",
 647                        sdata->name, mgmt->sa);
 648 #endif
 649                 return;
 650         }
 651         if (pos[1] != 0 &&
 652             (pos[1] != ifibss->ssid_len ||
 653              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 654                 /* Ignore ProbeReq for foreign SSID */
 655                 return;
 656         }
 657
 658         /* Reply with ProbeResp */
 659         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 660         if (!skb)
 661                 return;
 662
 663         resp = (struct ieee80211_mgmt *) skb->data;
 664         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 665 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 666         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 667                sdata->name, resp->da);
 668 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 669         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 670         ieee80211_tx_skb(sdata, skb);
 671 }
 672
 673 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 674                                          struct ieee80211_mgmt *mgmt,
 675                                          size_t len,
 676                                          struct ieee80211_rx_status *rx_status)
 677 {
 678         size_t baselen;
 679         struct ieee802_11_elems elems;
 680
 681         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 682                 return; /* ignore ProbeResp to foreign address */
 683
 684         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 685         if (baselen > len)
 686                 return;
 687
 688         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 689                                 &elems);
 690
 691         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 692 }
 693
 694 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 695                                      struct ieee80211_mgmt *mgmt,
 696                                      size_t len,
 697                                      struct ieee80211_rx_status *rx_status)
 698 {
 699         size_t baselen;
 700         struct ieee802_11_elems elems;
 701
 702         /* Process beacon from the current BSS */
 703         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 704         if (baselen > len)
 705                 return;
 706
 707         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 708
 709         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 710 }
 711
 712 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 713                                           struct sk_buff *skb)
 714 {
 715         struct ieee80211_rx_status *rx_status;
 716         struct ieee80211_mgmt *mgmt;
 717         u16 fc;
 718
 719         rx_status = IEEE80211_SKB_RXCB(skb);
 720         mgmt = (struct ieee80211_mgmt *) skb->data;
 721         fc = le16_to_cpu(mgmt->frame_control);
 722
 723         switch (fc & IEEE80211_FCTL_STYPE) {
 724         case IEEE80211_STYPE_PROBE_REQ:
 725                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 726                 break;
 727         case IEEE80211_STYPE_PROBE_RESP:
 728                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 729                                              rx_status);
 730                 break;
 731         case IEEE80211_STYPE_BEACON:
 732                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 733                                          rx_status);
 734                 break;
 735         case IEEE80211_STYPE_AUTH:
 736                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 737                 break;
 738         }
 739
 740         kfree_skb(skb);
 741 }
 742
 743 static void ieee80211_ibss_work(struct work_struct *work)
 744 {
 745         struct ieee80211_sub_if_data *sdata =
 746                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 747         struct ieee80211_local *local = sdata->local;
 748         struct ieee80211_if_ibss *ifibss;
 749         struct sk_buff *skb;
 750
 751         if (WARN_ON(local->suspended))
 752                 return;
 753
 754         if (!ieee80211_sdata_running(sdata))
 755                 return;
 756
 757         if (local->scanning)
 758                 return;
 759
 760         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 761                 return;
 762         ifibss = &sdata->u.ibss;
 763
 764         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 765                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 766
 767         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 768                 return;
 769
 770         switch (ifibss->state) {
 771         case IEEE80211_IBSS_MLME_SEARCH:
 772                 ieee80211_sta_find_ibss(sdata);
 773                 break;
 774         case IEEE80211_IBSS_MLME_JOINED:
 775                 ieee80211_sta_merge_ibss(sdata);
 776                 break;
 777         default:
 778                 WARN_ON(1);
 779                 break;
 780         }
 781 }
 782
 783 static void ieee80211_ibss_timer(unsigned long data)
 784 {
 785         struct ieee80211_sub_if_data *sdata =
 786                 (struct ieee80211_sub_if_data *) data;
 787         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 788         struct ieee80211_local *local = sdata->local;
 789
 790         if (local->quiescing) {
 791                 ifibss->timer_running = true;
 792                 return;
 793         }
 794
 795         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 796         ieee80211_queue_work(&local->hw, &ifibss->work);
 797 }
 798
 799 #ifdef CONFIG_PM
 800 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 801 {
 802         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 803
 804         cancel_work_sync(&ifibss->work);
 805         if (del_timer_sync(&ifibss->timer))
 806                 ifibss->timer_running = true;
 807 }
 808
 809 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 810 {
 811         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 812
 813         if (ifibss->timer_running) {
 814                 add_timer(&ifibss->timer);
 815                 ifibss->timer_running = false;
 816         }
 817 }
 818 #endif
 819
 820 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 821 {
 822         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 823
 824         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 825         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 826                     (unsigned long) sdata);
 827         skb_queue_head_init(&ifibss->skb_queue);
 828 }
 829
 830 /* scan finished notification */
 831 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 832 {
 833         struct ieee80211_sub_if_data *sdata;
 834
 835         mutex_lock(&local->iflist_mtx);
 836         list_for_each_entry(sdata, &local->interfaces, list) {
 837                 if (!ieee80211_sdata_running(sdata))
 838                         continue;
 839                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 840                         continue;
 841                 if (!sdata->u.ibss.ssid_len)
 842                         continue;
 843                 sdata->u.ibss.last_scan_completed = jiffies;
 844                 mod_timer(&sdata->u.ibss.timer, 0);
 845         }
 846         mutex_unlock(&local->iflist_mtx);
 847 }
 848
 849 ieee80211_rx_result
 850 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 851 {
 852         struct ieee80211_local *local = sdata->local;
 853         struct ieee80211_mgmt *mgmt;
 854         u16 fc;
 855
 856         if (skb->len < 24)
 857                 return RX_DROP_MONITOR;
 858
 859         mgmt = (struct ieee80211_mgmt *) skb->data;
 860         fc = le16_to_cpu(mgmt->frame_control);
 861
 862         switch (fc & IEEE80211_FCTL_STYPE) {
 863         case IEEE80211_STYPE_PROBE_RESP:
 864         case IEEE80211_STYPE_BEACON:
 865         case IEEE80211_STYPE_PROBE_REQ:
 866         case IEEE80211_STYPE_AUTH:
 867                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 868                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 869                 return RX_QUEUED;
 870         }
 871
 872         return RX_DROP_MONITOR;
 873 }
 874
 875 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 876                         struct cfg80211_ibss_params *params)
 877 {
 878         struct sk_buff *skb;
 879
 880         if (params->bssid) {
 881                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 882                 sdata->u.ibss.fixed_bssid = true;
 883         } else
 884                 sdata->u.ibss.fixed_bssid = false;
 885
 886         sdata->u.ibss.privacy = params->privacy;
 887
 888         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 889
 890         sdata->u.ibss.channel = params->channel;
 891         sdata->u.ibss.fixed_channel = params->channel_fixed;
 892
 893         if (params->ie) {
 894                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 895                                            GFP_KERNEL);
 896                 if (sdata->u.ibss.ie)
 897                         sdata->u.ibss.ie_len = params->ie_len;
 898         }
 899
 900         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 901                             36 /* bitrates */ +
 902                             34 /* SSID */ +
 903                             3  /* DS params */ +
 904                             4  /* IBSS params */ +
 905                             params->ie_len);
 906         if (!skb)
 907                 return -ENOMEM;
 908
 909         sdata->u.ibss.skb = skb;
 910         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 911         sdata->u.ibss.ibss_join_req = jiffies;
 912
 913         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 914
 915         /*
 916          * The ssid_len setting below is used to see whether
 917          * we are active, and we need all other settings
 918          * before that may get visible.
 919          */
 920         mb();
 921
 922         sdata->u.ibss.ssid_len = params->ssid_len;
 923
 924         ieee80211_recalc_idle(sdata->local);
 925
 926         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 927         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 928
 929         return 0;
 930 }
 931
 932 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 933 {
 934         struct sk_buff *skb;
 935
 936         del_timer_sync(&sdata->u.ibss.timer);
 937         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 938         cancel_work_sync(&sdata->u.ibss.work);
 939         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 940
 941         sta_info_flush(sdata->local, sdata);
 942
 943         /* remove beacon */
 944         kfree(sdata->u.ibss.ie);
 945         skb = sdata->u.ibss.presp;
 946         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 947         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 948         synchronize_rcu();
 949         kfree_skb(skb);
 950
 951         skb_queue_purge(&sdata->u.ibss.skb_queue);
 952         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 953         sdata->u.ibss.ssid_len = 0;
 954
 955         ieee80211_recalc_idle(sdata->local);
 956
 957         return 0;
 958 }