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/slab.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/rtnetlink.h>
  22 #include <net/mac80211.h>
  23 #include <asm/unaligned.h>
  24
  25 #include "ieee80211_i.h"
  26 #include "driver-ops.h"
  27 #include "rate.h"
  28
  29 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  30 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  31 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  32
  33 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  34 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  35 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  36
  37 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  38
  39
  40 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  41                                         struct ieee80211_mgmt *mgmt,
  42                                         size_t len)
  43 {
  44         u16 auth_alg, auth_transaction, status_code;
  45
  46         if (len < 24 + 6)
  47                 return;
  48
  49         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  50         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  51         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  52
  53         /*
  54          * IEEE 802.11 standard does not require authentication in IBSS
  55          * networks and most implementations do not seem to use it.
  56          * However, try to reply to authentication attempts if someone
  57          * has actually implemented this.
  58          */
  59         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  60                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  61                                     sdata->u.ibss.bssid, NULL, 0, 0);
  62 }
  63
  64 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  65                                       const u8 *bssid, const int beacon_int,
  66                                       struct ieee80211_channel *chan,
  67                                       const u32 basic_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;
  73         struct sk_buff *skb;
  74         struct ieee80211_mgmt *mgmt;
  75         u8 *pos;
  76         struct ieee80211_supported_band *sband;
  77         struct cfg80211_bss *bss;
  78         u32 bss_change;
  79         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  80
  81         /* Reset own TSF to allow time synchronization work. */
  82         drv_reset_tsf(local);
  83
  84         skb = ifibss->skb;
  85         rcu_assign_pointer(ifibss->presp, NULL);
  86         synchronize_rcu();
  87         skb->data = skb->head;
  88         skb->len = 0;
  89         skb_reset_tail_pointer(skb);
  90         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  91
  92         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  93                 sta_info_flush(sdata->local, sdata);
  94
  95         memcpy(ifibss->bssid, bssid, ETH_ALEN);
  96
  97         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
  98
  99         local->oper_channel = chan;
 100         local->oper_channel_type = NL80211_CHAN_NO_HT;
 101         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 102
 103         sband = local->hw.wiphy->bands[chan->band];
 104
 105         /* build supported rates array */
 106         pos = supp_rates;
 107         for (i = 0; i < sband->n_bitrates; i++) {
 108                 int rate = sband->bitrates[i].bitrate;
 109                 u8 basic = 0;
 110                 if (basic_rates & BIT(i))
 111                         basic = 0x80;
 112                 *pos++ = basic | (u8) (rate / 5);
 113         }
 114
 115         /* Build IBSS probe response */
 116         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 117         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 118         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 119                                           IEEE80211_STYPE_PROBE_RESP);
 120         memset(mgmt->da, 0xff, ETH_ALEN);
 121         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 122         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 123         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 124         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 125         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 126
 127         pos = skb_put(skb, 2 + ifibss->ssid_len);
 128         *pos++ = WLAN_EID_SSID;
 129         *pos++ = ifibss->ssid_len;
 130         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 131
 132         rates = sband->n_bitrates;
 133         if (rates > 8)
 134                 rates = 8;
 135         pos = skb_put(skb, 2 + rates);
 136         *pos++ = WLAN_EID_SUPP_RATES;
 137         *pos++ = rates;
 138         memcpy(pos, supp_rates, rates);
 139
 140         if (sband->band == IEEE80211_BAND_2GHZ) {
 141                 pos = skb_put(skb, 2 + 1);
 142                 *pos++ = WLAN_EID_DS_PARAMS;
 143                 *pos++ = 1;
 144                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 145         }
 146
 147         pos = skb_put(skb, 2 + 2);
 148         *pos++ = WLAN_EID_IBSS_PARAMS;
 149         *pos++ = 2;
 150         /* FIX: set ATIM window based on scan results */
 151         *pos++ = 0;
 152         *pos++ = 0;
 153
 154         if (sband->n_bitrates > 8) {
 155                 rates = sband->n_bitrates - 8;
 156                 pos = skb_put(skb, 2 + rates);
 157                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 158                 *pos++ = rates;
 159                 memcpy(pos, &supp_rates[8], rates);
 160         }
 161
 162         if (ifibss->ie_len)
 163                 memcpy(skb_put(skb, ifibss->ie_len),
 164                        ifibss->ie, ifibss->ie_len);
 165
 166         rcu_assign_pointer(ifibss->presp, skb);
 167
 168         sdata->vif.bss_conf.beacon_int = beacon_int;
 169         bss_change = BSS_CHANGED_BEACON_INT;
 170         bss_change |= ieee80211_reset_erp_info(sdata);
 171         bss_change |= BSS_CHANGED_BSSID;
 172         bss_change |= BSS_CHANGED_BEACON;
 173         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 174         ieee80211_bss_info_change_notify(sdata, bss_change);
 175
 176         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 177
 178         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 179         mod_timer(&ifibss->timer,
 180                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 181
 182         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 183                                         mgmt, skb->len, 0, GFP_KERNEL);
 184         cfg80211_put_bss(bss);
 185         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 186 }
 187
 188 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 189                                     struct ieee80211_bss *bss)
 190 {
 191         struct cfg80211_bss *cbss =
 192                 container_of((void *)bss, struct cfg80211_bss, priv);
 193         struct ieee80211_supported_band *sband;
 194         u32 basic_rates;
 195         int i, j;
 196         u16 beacon_int = cbss->beacon_interval;
 197
 198         if (beacon_int < 10)
 199                 beacon_int = 10;
 200
 201         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 202
 203         basic_rates = 0;
 204
 205         for (i = 0; i < bss->supp_rates_len; i++) {
 206                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 207                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 208
 209                 for (j = 0; j < sband->n_bitrates; j++) {
 210                         if (sband->bitrates[j].bitrate == rate) {
 211                                 if (is_basic)
 212                                         basic_rates |= BIT(j);
 213                                 break;
 214                         }
 215                 }
 216         }
 217
 218         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 219                                   beacon_int,
 220                                   cbss->channel,
 221                                   basic_rates,
 222                                   cbss->capability,
 223                                   cbss->tsf);
 224 }
 225
 226 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 227                                   struct ieee80211_mgmt *mgmt,
 228                                   size_t len,
 229                                   struct ieee80211_rx_status *rx_status,
 230                                   struct ieee802_11_elems *elems,
 231                                   bool beacon)
 232 {
 233         struct ieee80211_local *local = sdata->local;
 234         int freq;
 235         struct cfg80211_bss *cbss;
 236         struct ieee80211_bss *bss;
 237         struct sta_info *sta;
 238         struct ieee80211_channel *channel;
 239         u64 beacon_timestamp, rx_timestamp;
 240         u32 supp_rates = 0;
 241         enum ieee80211_band band = rx_status->band;
 242
 243         if (elems->ds_params && elems->ds_params_len == 1)
 244                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 245         else
 246                 freq = rx_status->freq;
 247
 248         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 249
 250         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 251                 return;
 252
 253         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 254             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 255                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 256
 257                 rcu_read_lock();
 258
 259                 sta = sta_info_get(sdata, mgmt->sa);
 260                 if (sta) {
 261                         u32 prev_rates;
 262
 263                         prev_rates = sta->sta.supp_rates[band];
 264                         /* make sure mandatory rates are always added */
 265                         sta->sta.supp_rates[band] = supp_rates |
 266                                 ieee80211_mandatory_rates(local, band);
 267
 268 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 269                         if (sta->sta.supp_rates[band] != prev_rates)
 270                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 271                                     "for %pM based on beacon info (0x%llx | "
 272                                     "0x%llx -> 0x%llx)\n",
 273                                     sdata->name,
 274                                     sta->sta.addr,
 275                                     (unsigned long long) prev_rates,
 276                                     (unsigned long long) supp_rates,
 277                                     (unsigned long long) sta->sta.supp_rates[band]);
 278 #endif
 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                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 375                                        supp_rates, GFP_KERNEL);
 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                                         gfp_t gfp)
 390 {
 391         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 392         struct ieee80211_local *local = sdata->local;
 393         struct sta_info *sta;
 394         int band = local->hw.conf.channel->band;
 395
 396         /*
 397          * XXX: Consider removing the least recently used entry and
 398          *      allow new one to be added.
 399          */
 400         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 401                 if (net_ratelimit())
 402                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 403                                sdata->name, addr);
 404                 return NULL;
 405         }
 406
 407         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 408                 return NULL;
 409
 410         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 411                 return NULL;
 412
 413 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 414         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 415                wiphy_name(local->hw.wiphy), addr, sdata->name);
 416 #endif
 417
 418         sta = sta_info_alloc(sdata, addr, gfp);
 419         if (!sta)
 420                 return NULL;
 421
 422         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 423
 424         /* make sure mandatory rates are always added */
 425         sta->sta.supp_rates[band] = supp_rates |
 426                         ieee80211_mandatory_rates(local, band);
 427
 428         rate_control_rate_init(sta);
 429
 430         /* If it fails, maybe we raced another insertion? */
 431         if (sta_info_insert(sta))
 432                 return sta_info_get(sdata, addr);
 433         return sta;
 434 }
 435
 436 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 437 {
 438         struct ieee80211_local *local = sdata->local;
 439         int active = 0;
 440         struct sta_info *sta;
 441
 442         rcu_read_lock();
 443
 444         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 445                 if (sta->sdata == sdata &&
 446                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 447                                jiffies)) {
 448                         active++;
 449                         break;
 450                 }
 451         }
 452
 453         rcu_read_unlock();
 454
 455         return active;
 456 }
 457
 458 /*
 459  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 460  */
 461
 462 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 463 {
 464         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 465
 466         mod_timer(&ifibss->timer,
 467                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 468
 469         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 470
 471         if (time_before(jiffies, ifibss->last_scan_completed +
 472                        IEEE80211_IBSS_MERGE_INTERVAL))
 473                 return;
 474
 475         if (ieee80211_sta_active_ibss(sdata))
 476                 return;
 477
 478         if (ifibss->fixed_channel)
 479                 return;
 480
 481         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 482                "IBSS networks with same SSID (merge)\n", sdata->name);
 483
 484         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
 485 }
 486
 487 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 488 {
 489         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 490         struct ieee80211_local *local = sdata->local;
 491         struct ieee80211_supported_band *sband;
 492         u8 bssid[ETH_ALEN];
 493         u16 capability;
 494         int i;
 495
 496         if (ifibss->fixed_bssid) {
 497                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 498         } else {
 499                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 500                  * own MAC address to make sure that devices that do not have proper
 501                  * random number generator get different BSSID. */
 502                 get_random_bytes(bssid, ETH_ALEN);
 503                 for (i = 0; i < ETH_ALEN; i++)
 504                         bssid[i] ^= sdata->vif.addr[i];
 505                 bssid[0] &= ~0x01;
 506                 bssid[0] |= 0x02;
 507         }
 508
 509         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 510                sdata->name, bssid);
 511
 512         sband = local->hw.wiphy->bands[ifibss->channel->band];
 513
 514         capability = WLAN_CAPABILITY_IBSS;
 515
 516         if (ifibss->privacy)
 517                 capability |= WLAN_CAPABILITY_PRIVACY;
 518         else
 519                 sdata->drop_unencrypted = 0;
 520
 521         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 522                                   ifibss->channel, 3, /* first two are basic */
 523                                   capability, 0);
 524 }
 525
 526 /*
 527  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 528  */
 529
 530 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 531 {
 532         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 533         struct ieee80211_local *local = sdata->local;
 534         struct cfg80211_bss *cbss;
 535         struct ieee80211_channel *chan = NULL;
 536         const u8 *bssid = NULL;
 537         int active_ibss;
 538         u16 capability;
 539
 540         active_ibss = ieee80211_sta_active_ibss(sdata);
 541 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 542         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 543                sdata->name, active_ibss);
 544 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 545
 546         if (active_ibss)
 547                 return;
 548
 549         capability = WLAN_CAPABILITY_IBSS;
 550         if (ifibss->privacy)
 551                 capability |= WLAN_CAPABILITY_PRIVACY;
 552         if (ifibss->fixed_bssid)
 553                 bssid = ifibss->bssid;
 554         if (ifibss->fixed_channel)
 555                 chan = ifibss->channel;
 556         if (!is_zero_ether_addr(ifibss->bssid))
 557                 bssid = ifibss->bssid;
 558         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 559                                 ifibss->ssid, ifibss->ssid_len,
 560                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 561                                 capability);
 562
 563         if (cbss) {
 564                 struct ieee80211_bss *bss;
 565
 566                 bss = (void *)cbss->priv;
 567 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 568                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 569                        "%pM\n", cbss->bssid, ifibss->bssid);
 570 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 571
 572                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 573                        " based on configured SSID\n",
 574                        sdata->name, cbss->bssid);
 575
 576                 ieee80211_sta_join_ibss(sdata, bss);
 577                 ieee80211_rx_bss_put(local, bss);
 578                 return;
 579         }
 580
 581 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 582         printk(KERN_DEBUG "   did not try to join ibss\n");
 583 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 584
 585         /* Selected IBSS not found in current scan results - try to scan */
 586         if (time_after(jiffies, ifibss->last_scan_completed +
 587                                         IEEE80211_SCAN_INTERVAL)) {
 588                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 589                        "join\n", sdata->name);
 590
 591                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
 592                                                 ifibss->ssid_len);
 593         } else {
 594                 int interval = IEEE80211_SCAN_INTERVAL;
 595
 596                 if (time_after(jiffies, ifibss->ibss_join_req +
 597                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 598                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 599                                 ieee80211_sta_create_ibss(sdata);
 600                                 return;
 601                         }
 602                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 603                                " %d MHz\n", sdata->name,
 604                                local->hw.conf.channel->center_freq);
 605
 606                         /* No IBSS found - decrease scan interval and continue
 607                          * scanning. */
 608                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 609                 }
 610
 611                 mod_timer(&ifibss->timer,
 612                           round_jiffies(jiffies + interval));
 613         }
 614 }
 615
 616 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 617                                         struct ieee80211_mgmt *mgmt,
 618                                         size_t len)
 619 {
 620         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 621         struct ieee80211_local *local = sdata->local;
 622         int tx_last_beacon;
 623         struct sk_buff *skb;
 624         struct ieee80211_mgmt *resp;
 625         u8 *pos, *end;
 626
 627         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 628             len < 24 + 2 || !ifibss->presp)
 629                 return;
 630
 631         tx_last_beacon = drv_tx_last_beacon(local);
 632
 633 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 634         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 635                " (tx_last_beacon=%d)\n",
 636                sdata->name, mgmt->sa, mgmt->da,
 637                mgmt->bssid, tx_last_beacon);
 638 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 639
 640         if (!tx_last_beacon)
 641                 return;
 642
 643         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 644             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 645                 return;
 646
 647         end = ((u8 *) mgmt) + len;
 648         pos = mgmt->u.probe_req.variable;
 649         if (pos[0] != WLAN_EID_SSID ||
 650             pos + 2 + pos[1] > end) {
 651 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 652                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 653                        "from %pM\n",
 654                        sdata->name, mgmt->sa);
 655 #endif
 656                 return;
 657         }
 658         if (pos[1] != 0 &&
 659             (pos[1] != ifibss->ssid_len ||
 660              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 661                 /* Ignore ProbeReq for foreign SSID */
 662                 return;
 663         }
 664
 665         /* Reply with ProbeResp */
 666         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 667         if (!skb)
 668                 return;
 669
 670         resp = (struct ieee80211_mgmt *) skb->data;
 671         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 672 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 673         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 674                sdata->name, resp->da);
 675 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 676         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 677         ieee80211_tx_skb(sdata, skb);
 678 }
 679
 680 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 681                                          struct ieee80211_mgmt *mgmt,
 682                                          size_t len,
 683                                          struct ieee80211_rx_status *rx_status)
 684 {
 685         size_t baselen;
 686         struct ieee802_11_elems elems;
 687
 688         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 689                 return; /* ignore ProbeResp to foreign address */
 690
 691         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 692         if (baselen > len)
 693                 return;
 694
 695         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 696                                 &elems);
 697
 698         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 699 }
 700
 701 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 702                                      struct ieee80211_mgmt *mgmt,
 703                                      size_t len,
 704                                      struct ieee80211_rx_status *rx_status)
 705 {
 706         size_t baselen;
 707         struct ieee802_11_elems elems;
 708
 709         /* Process beacon from the current BSS */
 710         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 711         if (baselen > len)
 712                 return;
 713
 714         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 715
 716         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 717 }
 718
 719 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 720                                           struct sk_buff *skb)
 721 {
 722         struct ieee80211_rx_status *rx_status;
 723         struct ieee80211_mgmt *mgmt;
 724         u16 fc;
 725
 726         rx_status = IEEE80211_SKB_RXCB(skb);
 727         mgmt = (struct ieee80211_mgmt *) skb->data;
 728         fc = le16_to_cpu(mgmt->frame_control);
 729
 730         switch (fc & IEEE80211_FCTL_STYPE) {
 731         case IEEE80211_STYPE_PROBE_REQ:
 732                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 733                 break;
 734         case IEEE80211_STYPE_PROBE_RESP:
 735                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 736                                              rx_status);
 737                 break;
 738         case IEEE80211_STYPE_BEACON:
 739                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 740                                          rx_status);
 741                 break;
 742         case IEEE80211_STYPE_AUTH:
 743                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 744                 break;
 745         }
 746
 747         kfree_skb(skb);
 748 }
 749
 750 static void ieee80211_ibss_work(struct work_struct *work)
 751 {
 752         struct ieee80211_sub_if_data *sdata =
 753                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 754         struct ieee80211_local *local = sdata->local;
 755         struct ieee80211_if_ibss *ifibss;
 756         struct sk_buff *skb;
 757
 758         if (WARN_ON(local->suspended))
 759                 return;
 760
 761         if (!ieee80211_sdata_running(sdata))
 762                 return;
 763
 764         if (local->scanning)
 765                 return;
 766
 767         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 768                 return;
 769         ifibss = &sdata->u.ibss;
 770
 771         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 772                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 773
 774         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 775                 return;
 776
 777         switch (ifibss->state) {
 778         case IEEE80211_IBSS_MLME_SEARCH:
 779                 ieee80211_sta_find_ibss(sdata);
 780                 break;
 781         case IEEE80211_IBSS_MLME_JOINED:
 782                 ieee80211_sta_merge_ibss(sdata);
 783                 break;
 784         default:
 785                 WARN_ON(1);
 786                 break;
 787         }
 788 }
 789
 790 static void ieee80211_ibss_timer(unsigned long data)
 791 {
 792         struct ieee80211_sub_if_data *sdata =
 793                 (struct ieee80211_sub_if_data *) data;
 794         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 795         struct ieee80211_local *local = sdata->local;
 796
 797         if (local->quiescing) {
 798                 ifibss->timer_running = true;
 799                 return;
 800         }
 801
 802         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 803         ieee80211_queue_work(&local->hw, &ifibss->work);
 804 }
 805
 806 #ifdef CONFIG_PM
 807 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 808 {
 809         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 810
 811         cancel_work_sync(&ifibss->work);
 812         if (del_timer_sync(&ifibss->timer))
 813                 ifibss->timer_running = true;
 814 }
 815
 816 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 817 {
 818         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 819
 820         if (ifibss->timer_running) {
 821                 add_timer(&ifibss->timer);
 822                 ifibss->timer_running = false;
 823         }
 824 }
 825 #endif
 826
 827 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 828 {
 829         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 830
 831         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 832         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 833                     (unsigned long) sdata);
 834         skb_queue_head_init(&ifibss->skb_queue);
 835 }
 836
 837 /* scan finished notification */
 838 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 839 {
 840         struct ieee80211_sub_if_data *sdata;
 841
 842         mutex_lock(&local->iflist_mtx);
 843         list_for_each_entry(sdata, &local->interfaces, list) {
 844                 if (!ieee80211_sdata_running(sdata))
 845                         continue;
 846                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 847                         continue;
 848                 if (!sdata->u.ibss.ssid_len)
 849                         continue;
 850                 sdata->u.ibss.last_scan_completed = jiffies;
 851                 mod_timer(&sdata->u.ibss.timer, 0);
 852         }
 853         mutex_unlock(&local->iflist_mtx);
 854 }
 855
 856 ieee80211_rx_result
 857 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 858 {
 859         struct ieee80211_local *local = sdata->local;
 860         struct ieee80211_mgmt *mgmt;
 861         u16 fc;
 862
 863         if (skb->len < 24)
 864                 return RX_DROP_MONITOR;
 865
 866         mgmt = (struct ieee80211_mgmt *) skb->data;
 867         fc = le16_to_cpu(mgmt->frame_control);
 868
 869         switch (fc & IEEE80211_FCTL_STYPE) {
 870         case IEEE80211_STYPE_PROBE_RESP:
 871         case IEEE80211_STYPE_BEACON:
 872         case IEEE80211_STYPE_PROBE_REQ:
 873         case IEEE80211_STYPE_AUTH:
 874                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 875                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
 876                 return RX_QUEUED;
 877         }
 878
 879         return RX_DROP_MONITOR;
 880 }
 881
 882 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 883                         struct cfg80211_ibss_params *params)
 884 {
 885         struct sk_buff *skb;
 886
 887         if (params->bssid) {
 888                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 889                 sdata->u.ibss.fixed_bssid = true;
 890         } else
 891                 sdata->u.ibss.fixed_bssid = false;
 892
 893         sdata->u.ibss.privacy = params->privacy;
 894
 895         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 896
 897         sdata->u.ibss.channel = params->channel;
 898         sdata->u.ibss.fixed_channel = params->channel_fixed;
 899
 900         if (params->ie) {
 901                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 902                                            GFP_KERNEL);
 903                 if (sdata->u.ibss.ie)
 904                         sdata->u.ibss.ie_len = params->ie_len;
 905         }
 906
 907         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 908                             36 /* bitrates */ +
 909                             34 /* SSID */ +
 910                             3  /* DS params */ +
 911                             4  /* IBSS params */ +
 912                             params->ie_len);
 913         if (!skb)
 914                 return -ENOMEM;
 915
 916         sdata->u.ibss.skb = skb;
 917         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 918         sdata->u.ibss.ibss_join_req = jiffies;
 919
 920         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 921
 922         /*
 923          * The ssid_len setting below is used to see whether
 924          * we are active, and we need all other settings
 925          * before that may get visible.
 926          */
 927         mb();
 928
 929         sdata->u.ibss.ssid_len = params->ssid_len;
 930
 931         ieee80211_recalc_idle(sdata->local);
 932
 933         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 934         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
 935
 936         return 0;
 937 }
 938
 939 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 940 {
 941         struct sk_buff *skb;
 942
 943         del_timer_sync(&sdata->u.ibss.timer);
 944         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 945         cancel_work_sync(&sdata->u.ibss.work);
 946         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
 947
 948         sta_info_flush(sdata->local, sdata);
 949
 950         /* remove beacon */
 951         kfree(sdata->u.ibss.ie);
 952         skb = sdata->u.ibss.presp;
 953         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
 954         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 955         synchronize_rcu();
 956         kfree_skb(skb);
 957
 958         skb_queue_purge(&sdata->u.ibss.skb_queue);
 959         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 960         sdata->u.ibss.ssid_len = 0;
 961
 962         ieee80211_recalc_idle(sdata->local);
 963
 964         return 0;
 965 }