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_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;
  44
  45         lockdep_assert_held(&sdata->u.ibss.mtx);
  46
  47         if (len < 24 + 6)
  48                 return;
  49
  50         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  51         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  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         enum nl80211_channel_type channel_type;
  81
  82         lockdep_assert_held(&ifibss->mtx);
  83
  84         /* Reset own TSF to allow time synchronization work. */
  85         drv_reset_tsf(local, sdata);
  86
  87         skb = ifibss->skb;
  88         RCU_INIT_POINTER(ifibss->presp, NULL);
  89         synchronize_rcu();
  90         skb->data = skb->head;
  91         skb->len = 0;
  92         skb_reset_tail_pointer(skb);
  93         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  94
  95         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  96                 sta_info_flush(sdata->local, sdata);
  97
  98         /* if merging, indicate to driver that we leave the old IBSS */
  99         if (sdata->vif.bss_conf.ibss_joined) {
 100                 sdata->vif.bss_conf.ibss_joined = false;
 101                 netif_carrier_off(sdata->dev);
 102                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
 103         }
 104
 105         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 106
 107         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 108
 109         channel_type = ifibss->channel_type;
 110         if (channel_type > NL80211_CHAN_HT20 &&
 111             !cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
 112                 channel_type = NL80211_CHAN_HT20;
 113         if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
 114                 /* can only fail due to HT40+/- mismatch */
 115                 channel_type = NL80211_CHAN_HT20;
 116                 WARN_ON(!ieee80211_set_channel_type(local, sdata,
 117                                                     NL80211_CHAN_HT20));
 118         }
 119         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 120
 121         sband = local->hw.wiphy->bands[chan->band];
 122
 123         /* build supported rates array */
 124         pos = supp_rates;
 125         for (i = 0; i < sband->n_bitrates; i++) {
 126                 int rate = sband->bitrates[i].bitrate;
 127                 u8 basic = 0;
 128                 if (basic_rates & BIT(i))
 129                         basic = 0x80;
 130                 *pos++ = basic | (u8) (rate / 5);
 131         }
 132
 133         /* Build IBSS probe response */
 134         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 135         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 136         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 137                                           IEEE80211_STYPE_PROBE_RESP);
 138         memset(mgmt->da, 0xff, ETH_ALEN);
 139         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 140         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 141         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 142         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 143         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 144
 145         pos = skb_put(skb, 2 + ifibss->ssid_len);
 146         *pos++ = WLAN_EID_SSID;
 147         *pos++ = ifibss->ssid_len;
 148         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 149
 150         rates = sband->n_bitrates;
 151         if (rates > 8)
 152                 rates = 8;
 153         pos = skb_put(skb, 2 + rates);
 154         *pos++ = WLAN_EID_SUPP_RATES;
 155         *pos++ = rates;
 156         memcpy(pos, supp_rates, rates);
 157
 158         if (sband->band == IEEE80211_BAND_2GHZ) {
 159                 pos = skb_put(skb, 2 + 1);
 160                 *pos++ = WLAN_EID_DS_PARAMS;
 161                 *pos++ = 1;
 162                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 163         }
 164
 165         pos = skb_put(skb, 2 + 2);
 166         *pos++ = WLAN_EID_IBSS_PARAMS;
 167         *pos++ = 2;
 168         /* FIX: set ATIM window based on scan results */
 169         *pos++ = 0;
 170         *pos++ = 0;
 171
 172         if (sband->n_bitrates > 8) {
 173                 rates = sband->n_bitrates - 8;
 174                 pos = skb_put(skb, 2 + rates);
 175                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 176                 *pos++ = rates;
 177                 memcpy(pos, &supp_rates[8], rates);
 178         }
 179
 180         if (ifibss->ie_len)
 181                 memcpy(skb_put(skb, ifibss->ie_len),
 182                        ifibss->ie, ifibss->ie_len);
 183
 184         /* add HT capability and information IEs */
 185         if (channel_type && sband->ht_cap.ht_supported) {
 186                 pos = skb_put(skb, 4 +
 187                                    sizeof(struct ieee80211_ht_cap) +
 188                                    sizeof(struct ieee80211_ht_info));
 189                 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
 190                                                 sband->ht_cap.cap);
 191                 pos = ieee80211_ie_build_ht_info(pos,
 192                                                  &sband->ht_cap,
 193                                                  chan,
 194                                                  channel_type);
 195         }
 196
 197         if (local->hw.queues >= 4) {
 198                 pos = skb_put(skb, 9);
 199                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 200                 *pos++ = 7; /* len */
 201                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 202                 *pos++ = 0x50;
 203                 *pos++ = 0xf2;
 204                 *pos++ = 2; /* WME */
 205                 *pos++ = 0; /* WME info */
 206                 *pos++ = 1; /* WME ver */
 207                 *pos++ = 0; /* U-APSD no in use */
 208         }
 209
 210         RCU_INIT_POINTER(ifibss->presp, skb);
 211
 212         sdata->vif.bss_conf.beacon_int = beacon_int;
 213         sdata->vif.bss_conf.basic_rates = basic_rates;
 214         bss_change = BSS_CHANGED_BEACON_INT;
 215         bss_change |= ieee80211_reset_erp_info(sdata);
 216         bss_change |= BSS_CHANGED_BSSID;
 217         bss_change |= BSS_CHANGED_BEACON;
 218         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 219         bss_change |= BSS_CHANGED_BASIC_RATES;
 220         bss_change |= BSS_CHANGED_HT;
 221         bss_change |= BSS_CHANGED_IBSS;
 222         sdata->vif.bss_conf.ibss_joined = true;
 223         ieee80211_bss_info_change_notify(sdata, bss_change);
 224
 225         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 226
 227         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 228         mod_timer(&ifibss->timer,
 229                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 230
 231         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 232                                         mgmt, skb->len, 0, GFP_KERNEL);
 233         cfg80211_put_bss(bss);
 234         netif_carrier_on(sdata->dev);
 235         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 236 }
 237
 238 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 239                                     struct ieee80211_bss *bss)
 240 {
 241         struct cfg80211_bss *cbss =
 242                 container_of((void *)bss, struct cfg80211_bss, priv);
 243         struct ieee80211_supported_band *sband;
 244         u32 basic_rates;
 245         int i, j;
 246         u16 beacon_int = cbss->beacon_interval;
 247
 248         lockdep_assert_held(&sdata->u.ibss.mtx);
 249
 250         if (beacon_int < 10)
 251                 beacon_int = 10;
 252
 253         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 254
 255         basic_rates = 0;
 256
 257         for (i = 0; i < bss->supp_rates_len; i++) {
 258                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 259                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 260
 261                 for (j = 0; j < sband->n_bitrates; j++) {
 262                         if (sband->bitrates[j].bitrate == rate) {
 263                                 if (is_basic)
 264                                         basic_rates |= BIT(j);
 265                                 break;
 266                         }
 267                 }
 268         }
 269
 270         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 271                                   beacon_int,
 272                                   cbss->channel,
 273                                   basic_rates,
 274                                   cbss->capability,
 275                                   cbss->tsf);
 276 }
 277
 278 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 279                                   struct ieee80211_mgmt *mgmt,
 280                                   size_t len,
 281                                   struct ieee80211_rx_status *rx_status,
 282                                   struct ieee802_11_elems *elems,
 283                                   bool beacon)
 284 {
 285         struct ieee80211_local *local = sdata->local;
 286         int freq;
 287         struct cfg80211_bss *cbss;
 288         struct ieee80211_bss *bss;
 289         struct sta_info *sta;
 290         struct ieee80211_channel *channel;
 291         u64 beacon_timestamp, rx_timestamp;
 292         u32 supp_rates = 0;
 293         enum ieee80211_band band = rx_status->band;
 294         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 295         bool rates_updated = false;
 296
 297         if (elems->ds_params && elems->ds_params_len == 1)
 298                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
 299                                                       band);
 300         else
 301                 freq = rx_status->freq;
 302
 303         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 304
 305         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 306                 return;
 307
 308         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 309             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 310
 311                 rcu_read_lock();
 312                 sta = sta_info_get(sdata, mgmt->sa);
 313
 314                 if (elems->supp_rates) {
 315                         supp_rates = ieee80211_sta_get_rates(local, elems,
 316                                                              band);
 317                         if (sta) {
 318                                 u32 prev_rates;
 319
 320                                 prev_rates = sta->sta.supp_rates[band];
 321                                 /* make sure mandatory rates are always added */
 322                                 sta->sta.supp_rates[band] = supp_rates |
 323                                         ieee80211_mandatory_rates(local, band);
 324
 325                                 if (sta->sta.supp_rates[band] != prev_rates) {
 326 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 327                                         printk(KERN_DEBUG
 328                                                 "%s: updated supp_rates set "
 329                                                 "for %pM based on beacon"
 330                                                 "/probe_resp (0x%x -> 0x%x)\n",
 331                                                 sdata->name, sta->sta.addr,
 332                                                 prev_rates,
 333                                                 sta->sta.supp_rates[band]);
 334 #endif
 335                                         rates_updated = true;
 336                                 }
 337                         } else
 338                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
 339                                                 mgmt->sa, supp_rates,
 340                                                 GFP_ATOMIC);
 341                 }
 342
 343                 if (sta && elems->wmm_info)
 344                         set_sta_flag(sta, WLAN_STA_WME);
 345
 346                 if (sta && elems->ht_info_elem && elems->ht_cap_elem &&
 347                     sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
 348                         /* we both use HT */
 349                         struct ieee80211_sta_ht_cap sta_ht_cap_new;
 350                         enum nl80211_channel_type channel_type =
 351                                 ieee80211_ht_info_to_channel_type(
 352                                                         elems->ht_info_elem);
 353
 354                         ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 355                                                           elems->ht_cap_elem,
 356                                                           &sta_ht_cap_new);
 357
 358                         /*
 359                          * fall back to HT20 if we don't use or use
 360                          * the other extension channel
 361                          */
 362                         if ((channel_type == NL80211_CHAN_HT40MINUS ||
 363                              channel_type == NL80211_CHAN_HT40PLUS) &&
 364                             channel_type != sdata->u.ibss.channel_type)
 365                                 sta_ht_cap_new.cap &=
 366                                         ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 367
 368                         if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
 369                                    sizeof(sta_ht_cap_new))) {
 370                                 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
 371                                        sizeof(sta_ht_cap_new));
 372                                 rates_updated = true;
 373                         }
 374                 }
 375
 376                 if (sta && rates_updated)
 377                         rate_control_rate_init(sta);
 378
 379                 rcu_read_unlock();
 380         }
 381
 382         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 383                                         channel, beacon);
 384         if (!bss)
 385                 return;
 386
 387         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 388
 389         /* was just updated in ieee80211_bss_info_update */
 390         beacon_timestamp = cbss->tsf;
 391
 392         /* check if we need to merge IBSS */
 393
 394         /* we use a fixed BSSID */
 395         if (sdata->u.ibss.fixed_bssid)
 396                 goto put_bss;
 397
 398         /* not an IBSS */
 399         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 400                 goto put_bss;
 401
 402         /* different channel */
 403         if (cbss->channel != local->oper_channel)
 404                 goto put_bss;
 405
 406         /* different SSID */
 407         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 408             memcmp(elems->ssid, sdata->u.ibss.ssid,
 409                                 sdata->u.ibss.ssid_len))
 410                 goto put_bss;
 411
 412         /* same BSSID */
 413         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 414                 goto put_bss;
 415
 416         if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
 417                 /*
 418                  * For correct IBSS merging we need mactime; since mactime is
 419                  * defined as the time the first data symbol of the frame hits
 420                  * the PHY, and the timestamp of the beacon is defined as "the
 421                  * time that the data symbol containing the first bit of the
 422                  * timestamp is transmitted to the PHY plus the transmitting
 423                  * STA's delays through its local PHY from the MAC-PHY
 424                  * interface to its interface with the WM" (802.11 11.1.2)
 425                  * - equals the time this bit arrives at the receiver - we have
 426                  * to take into account the offset between the two.
 427                  *
 428                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 429                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 430                  */
 431                 int rate;
 432
 433                 if (rx_status->flag & RX_FLAG_HT)
 434                         rate = 65; /* TODO: HT rates */
 435                 else
 436                         rate = local->hw.wiphy->bands[band]->
 437                                 bitrates[rx_status->rate_idx].bitrate;
 438
 439                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 440         } else {
 441                 /*
 442                  * second best option: get current TSF
 443                  * (will return -1 if not supported)
 444                  */
 445                 rx_timestamp = drv_get_tsf(local, sdata);
 446         }
 447
 448 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 449         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 450                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 451                mgmt->sa, mgmt->bssid,
 452                (unsigned long long)rx_timestamp,
 453                (unsigned long long)beacon_timestamp,
 454                (unsigned long long)(rx_timestamp - beacon_timestamp),
 455                jiffies);
 456 #endif
 457
 458         if (beacon_timestamp > rx_timestamp) {
 459 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 460                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 461                        "local TSF - IBSS merge with BSSID %pM\n",
 462                        sdata->name, mgmt->bssid);
 463 #endif
 464                 ieee80211_sta_join_ibss(sdata, bss);
 465                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 466                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 467                                        supp_rates, GFP_KERNEL);
 468         }
 469
 470  put_bss:
 471         ieee80211_rx_bss_put(local, bss);
 472 }
 473
 474 /*
 475  * Add a new IBSS station, will also be called by the RX code when,
 476  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 477  * must be callable in atomic context.
 478  */
 479 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 480                                         u8 *bssid, u8 *addr, u32 supp_rates,
 481                                         gfp_t gfp)
 482 {
 483         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 484         struct ieee80211_local *local = sdata->local;
 485         struct sta_info *sta;
 486         int band = local->hw.conf.channel->band;
 487
 488         /*
 489          * XXX: Consider removing the least recently used entry and
 490          *      allow new one to be added.
 491          */
 492         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 493                 if (net_ratelimit())
 494                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 495                                sdata->name, addr);
 496                 return NULL;
 497         }
 498
 499         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 500                 return NULL;
 501
 502         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 503                 return NULL;
 504
 505 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 506         wiphy_debug(local->hw.wiphy, "Adding new IBSS station %pM (dev=%s)\n",
 507                     addr, sdata->name);
 508 #endif
 509
 510         sta = sta_info_alloc(sdata, addr, gfp);
 511         if (!sta)
 512                 return NULL;
 513
 514         sta->last_rx = jiffies;
 515
 516         sta_info_move_state(sta, IEEE80211_STA_AUTH);
 517         sta_info_move_state(sta, IEEE80211_STA_ASSOC);
 518         sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
 519
 520         /* make sure mandatory rates are always added */
 521         sta->sta.supp_rates[band] = supp_rates |
 522                         ieee80211_mandatory_rates(local, band);
 523
 524         rate_control_rate_init(sta);
 525
 526         /* If it fails, maybe we raced another insertion? */
 527         if (sta_info_insert(sta))
 528                 return sta_info_get(sdata, addr);
 529         return sta;
 530 }
 531
 532 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 533 {
 534         struct ieee80211_local *local = sdata->local;
 535         int active = 0;
 536         struct sta_info *sta;
 537
 538         lockdep_assert_held(&sdata->u.ibss.mtx);
 539
 540         rcu_read_lock();
 541
 542         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 543                 if (sta->sdata == sdata &&
 544                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 545                                jiffies)) {
 546                         active++;
 547                         break;
 548                 }
 549         }
 550
 551         rcu_read_unlock();
 552
 553         return active;
 554 }
 555
 556 /*
 557  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 558  */
 559
 560 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 561 {
 562         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 563
 564         lockdep_assert_held(&ifibss->mtx);
 565
 566         mod_timer(&ifibss->timer,
 567                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 568
 569         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 570
 571         if (time_before(jiffies, ifibss->last_scan_completed +
 572                        IEEE80211_IBSS_MERGE_INTERVAL))
 573                 return;
 574
 575         if (ieee80211_sta_active_ibss(sdata))
 576                 return;
 577
 578         if (ifibss->fixed_channel)
 579                 return;
 580
 581         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 582                "IBSS networks with same SSID (merge)\n", sdata->name);
 583
 584         ieee80211_request_internal_scan(sdata,
 585                         ifibss->ssid, ifibss->ssid_len,
 586                         ifibss->fixed_channel ? ifibss->channel : NULL);
 587 }
 588
 589 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 590 {
 591         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 592         u8 bssid[ETH_ALEN];
 593         u16 capability;
 594         int i;
 595
 596         lockdep_assert_held(&ifibss->mtx);
 597
 598         if (ifibss->fixed_bssid) {
 599                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 600         } else {
 601                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 602                  * own MAC address to make sure that devices that do not have proper
 603                  * random number generator get different BSSID. */
 604                 get_random_bytes(bssid, ETH_ALEN);
 605                 for (i = 0; i < ETH_ALEN; i++)
 606                         bssid[i] ^= sdata->vif.addr[i];
 607                 bssid[0] &= ~0x01;
 608                 bssid[0] |= 0x02;
 609         }
 610
 611         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 612                sdata->name, bssid);
 613
 614         capability = WLAN_CAPABILITY_IBSS;
 615
 616         if (ifibss->privacy)
 617                 capability |= WLAN_CAPABILITY_PRIVACY;
 618         else
 619                 sdata->drop_unencrypted = 0;
 620
 621         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 622                                   ifibss->channel, ifibss->basic_rates,
 623                                   capability, 0);
 624 }
 625
 626 /*
 627  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 628  */
 629
 630 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 631 {
 632         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 633         struct ieee80211_local *local = sdata->local;
 634         struct cfg80211_bss *cbss;
 635         struct ieee80211_channel *chan = NULL;
 636         const u8 *bssid = NULL;
 637         int active_ibss;
 638         u16 capability;
 639
 640         lockdep_assert_held(&ifibss->mtx);
 641
 642         active_ibss = ieee80211_sta_active_ibss(sdata);
 643 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 644         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 645                sdata->name, active_ibss);
 646 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 647
 648         if (active_ibss)
 649                 return;
 650
 651         capability = WLAN_CAPABILITY_IBSS;
 652         if (ifibss->privacy)
 653                 capability |= WLAN_CAPABILITY_PRIVACY;
 654         if (ifibss->fixed_bssid)
 655                 bssid = ifibss->bssid;
 656         if (ifibss->fixed_channel)
 657                 chan = ifibss->channel;
 658         if (!is_zero_ether_addr(ifibss->bssid))
 659                 bssid = ifibss->bssid;
 660         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 661                                 ifibss->ssid, ifibss->ssid_len,
 662                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 663                                 capability);
 664
 665         if (cbss) {
 666                 struct ieee80211_bss *bss;
 667
 668                 bss = (void *)cbss->priv;
 669 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 670                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 671                        "%pM\n", cbss->bssid, ifibss->bssid);
 672 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 673
 674                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 675                        " based on configured SSID\n",
 676                        sdata->name, cbss->bssid);
 677
 678                 ieee80211_sta_join_ibss(sdata, bss);
 679                 ieee80211_rx_bss_put(local, bss);
 680                 return;
 681         }
 682
 683 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 684         printk(KERN_DEBUG "   did not try to join ibss\n");
 685 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 686
 687         /* Selected IBSS not found in current scan results - try to scan */
 688         if (time_after(jiffies, ifibss->last_scan_completed +
 689                                         IEEE80211_SCAN_INTERVAL)) {
 690                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 691                        "join\n", sdata->name);
 692
 693                 ieee80211_request_internal_scan(sdata,
 694                                 ifibss->ssid, ifibss->ssid_len,
 695                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 696         } else {
 697                 int interval = IEEE80211_SCAN_INTERVAL;
 698
 699                 if (time_after(jiffies, ifibss->ibss_join_req +
 700                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 701                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 702                                 ieee80211_sta_create_ibss(sdata);
 703                                 return;
 704                         }
 705                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 706                                " %d MHz\n", sdata->name,
 707                                local->hw.conf.channel->center_freq);
 708
 709                         /* No IBSS found - decrease scan interval and continue
 710                          * scanning. */
 711                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 712                 }
 713
 714                 mod_timer(&ifibss->timer,
 715                           round_jiffies(jiffies + interval));
 716         }
 717 }
 718
 719 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 720                                         struct sk_buff *req)
 721 {
 722         struct ieee80211_mgmt *mgmt = (void *)req->data;
 723         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 724         struct ieee80211_local *local = sdata->local;
 725         int tx_last_beacon, len = req->len;
 726         struct sk_buff *skb;
 727         struct ieee80211_mgmt *resp;
 728         struct sk_buff *presp;
 729         u8 *pos, *end;
 730
 731         lockdep_assert_held(&ifibss->mtx);
 732
 733         presp = rcu_dereference_protected(ifibss->presp,
 734                                           lockdep_is_held(&ifibss->mtx));
 735
 736         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 737             len < 24 + 2 || !presp)
 738                 return;
 739
 740         tx_last_beacon = drv_tx_last_beacon(local);
 741
 742 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 743         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 744                " (tx_last_beacon=%d)\n",
 745                sdata->name, mgmt->sa, mgmt->da,
 746                mgmt->bssid, tx_last_beacon);
 747 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 748
 749         if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
 750                 return;
 751
 752         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 753             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 754                 return;
 755
 756         end = ((u8 *) mgmt) + len;
 757         pos = mgmt->u.probe_req.variable;
 758         if (pos[0] != WLAN_EID_SSID ||
 759             pos + 2 + pos[1] > end) {
 760 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 761                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 762                        "from %pM\n",
 763                        sdata->name, mgmt->sa);
 764 #endif
 765                 return;
 766         }
 767         if (pos[1] != 0 &&
 768             (pos[1] != ifibss->ssid_len ||
 769              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 770                 /* Ignore ProbeReq for foreign SSID */
 771                 return;
 772         }
 773
 774         /* Reply with ProbeResp */
 775         skb = skb_copy(presp, GFP_KERNEL);
 776         if (!skb)
 777                 return;
 778
 779         resp = (struct ieee80211_mgmt *) skb->data;
 780         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 781 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 782         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 783                sdata->name, resp->da);
 784 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 785         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 786         ieee80211_tx_skb(sdata, skb);
 787 }
 788
 789 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 790                                          struct ieee80211_mgmt *mgmt,
 791                                          size_t len,
 792                                          struct ieee80211_rx_status *rx_status)
 793 {
 794         size_t baselen;
 795         struct ieee802_11_elems elems;
 796
 797         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 798                 return; /* ignore ProbeResp to foreign address */
 799
 800         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 801         if (baselen > len)
 802                 return;
 803
 804         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 805                                 &elems);
 806
 807         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 808 }
 809
 810 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 811                                      struct ieee80211_mgmt *mgmt,
 812                                      size_t len,
 813                                      struct ieee80211_rx_status *rx_status)
 814 {
 815         size_t baselen;
 816         struct ieee802_11_elems elems;
 817
 818         /* Process beacon from the current BSS */
 819         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 820         if (baselen > len)
 821                 return;
 822
 823         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 824
 825         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 826 }
 827
 828 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 829                                    struct sk_buff *skb)
 830 {
 831         struct ieee80211_rx_status *rx_status;
 832         struct ieee80211_mgmt *mgmt;
 833         u16 fc;
 834
 835         rx_status = IEEE80211_SKB_RXCB(skb);
 836         mgmt = (struct ieee80211_mgmt *) skb->data;
 837         fc = le16_to_cpu(mgmt->frame_control);
 838
 839         mutex_lock(&sdata->u.ibss.mtx);
 840
 841         if (!sdata->u.ibss.ssid_len)
 842                 goto mgmt_out; /* not ready to merge yet */
 843
 844         switch (fc & IEEE80211_FCTL_STYPE) {
 845         case IEEE80211_STYPE_PROBE_REQ:
 846                 ieee80211_rx_mgmt_probe_req(sdata, skb);
 847                 break;
 848         case IEEE80211_STYPE_PROBE_RESP:
 849                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 850                                              rx_status);
 851                 break;
 852         case IEEE80211_STYPE_BEACON:
 853                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 854                                          rx_status);
 855                 break;
 856         case IEEE80211_STYPE_AUTH:
 857                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 858                 break;
 859         }
 860
 861  mgmt_out:
 862         mutex_unlock(&sdata->u.ibss.mtx);
 863 }
 864
 865 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 866 {
 867         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 868
 869         mutex_lock(&ifibss->mtx);
 870
 871         /*
 872          * Work could be scheduled after scan or similar
 873          * when we aren't even joined (or trying) with a
 874          * network.
 875          */
 876         if (!ifibss->ssid_len)
 877                 goto out;
 878
 879         switch (ifibss->state) {
 880         case IEEE80211_IBSS_MLME_SEARCH:
 881                 ieee80211_sta_find_ibss(sdata);
 882                 break;
 883         case IEEE80211_IBSS_MLME_JOINED:
 884                 ieee80211_sta_merge_ibss(sdata);
 885                 break;
 886         default:
 887                 WARN_ON(1);
 888                 break;
 889         }
 890
 891  out:
 892         mutex_unlock(&ifibss->mtx);
 893 }
 894
 895 static void ieee80211_ibss_timer(unsigned long data)
 896 {
 897         struct ieee80211_sub_if_data *sdata =
 898                 (struct ieee80211_sub_if_data *) data;
 899         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 900         struct ieee80211_local *local = sdata->local;
 901
 902         if (local->quiescing) {
 903                 ifibss->timer_running = true;
 904                 return;
 905         }
 906
 907         ieee80211_queue_work(&local->hw, &sdata->work);
 908 }
 909
 910 #ifdef CONFIG_PM
 911 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 912 {
 913         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 914
 915         if (del_timer_sync(&ifibss->timer))
 916                 ifibss->timer_running = true;
 917 }
 918
 919 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 920 {
 921         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 922
 923         if (ifibss->timer_running) {
 924                 add_timer(&ifibss->timer);
 925                 ifibss->timer_running = false;
 926         }
 927 }
 928 #endif
 929
 930 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 931 {
 932         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 933
 934         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 935                     (unsigned long) sdata);
 936         mutex_init(&ifibss->mtx);
 937 }
 938
 939 /* scan finished notification */
 940 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 941 {
 942         struct ieee80211_sub_if_data *sdata;
 943
 944         mutex_lock(&local->iflist_mtx);
 945         list_for_each_entry(sdata, &local->interfaces, list) {
 946                 if (!ieee80211_sdata_running(sdata))
 947                         continue;
 948                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 949                         continue;
 950                 sdata->u.ibss.last_scan_completed = jiffies;
 951                 ieee80211_queue_work(&local->hw, &sdata->work);
 952         }
 953         mutex_unlock(&local->iflist_mtx);
 954 }
 955
 956 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 957                         struct cfg80211_ibss_params *params)
 958 {
 959         struct sk_buff *skb;
 960         u32 changed = 0;
 961
 962         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 963                             sizeof(struct ieee80211_hdr_3addr) +
 964                             12 /* struct ieee80211_mgmt.u.beacon */ +
 965                             2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
 966                             2 + 8 /* max Supported Rates */ +
 967                             3 /* max DS params */ +
 968                             4 /* IBSS params */ +
 969                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 970                             2 + sizeof(struct ieee80211_ht_cap) +
 971                             2 + sizeof(struct ieee80211_ht_info) +
 972                             params->ie_len);
 973         if (!skb)
 974                 return -ENOMEM;
 975
 976         mutex_lock(&sdata->u.ibss.mtx);
 977
 978         if (params->bssid) {
 979                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 980                 sdata->u.ibss.fixed_bssid = true;
 981         } else
 982                 sdata->u.ibss.fixed_bssid = false;
 983
 984         sdata->u.ibss.privacy = params->privacy;
 985         sdata->u.ibss.basic_rates = params->basic_rates;
 986         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
 987                sizeof(params->mcast_rate));
 988
 989         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 990
 991         sdata->u.ibss.channel = params->channel;
 992         sdata->u.ibss.channel_type = params->channel_type;
 993         sdata->u.ibss.fixed_channel = params->channel_fixed;
 994
 995         /* fix ourselves to that channel now already */
 996         if (params->channel_fixed) {
 997                 sdata->local->oper_channel = params->channel;
 998                 if (!ieee80211_set_channel_type(sdata->local, sdata,
 999                                                params->channel_type)) {
1000                         mutex_unlock(&sdata->u.ibss.mtx);
1001                         kfree_skb(skb);
1002                         return -EINVAL;
1003                 }
1004         }
1005
1006         if (params->ie) {
1007                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1008                                            GFP_KERNEL);
1009                 if (sdata->u.ibss.ie)
1010                         sdata->u.ibss.ie_len = params->ie_len;
1011         }
1012
1013         sdata->u.ibss.skb = skb;
1014         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1015         sdata->u.ibss.ibss_join_req = jiffies;
1016
1017         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
1018         sdata->u.ibss.ssid_len = params->ssid_len;
1019
1020         mutex_unlock(&sdata->u.ibss.mtx);
1021
1022         mutex_lock(&sdata->local->mtx);
1023         ieee80211_recalc_idle(sdata->local);
1024         mutex_unlock(&sdata->local->mtx);
1025
1026         /*
1027          * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1028          * reserved, but an HT STA shall protect HT transmissions as though
1029          * the HT Protection field were set to non-HT mixed mode.
1030          *
1031          * In an IBSS, the RIFS Mode field of the HT Operation element is
1032          * also reserved, but an HT STA shall operate as though this field
1033          * were set to 1.
1034          */
1035
1036         sdata->vif.bss_conf.ht_operation_mode |=
1037                   IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1038                 | IEEE80211_HT_PARAM_RIFS_MODE;
1039
1040         changed |= BSS_CHANGED_HT;
1041         ieee80211_bss_info_change_notify(sdata, changed);
1042
1043         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1044
1045         return 0;
1046 }
1047
1048 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1049 {
1050         struct sk_buff *skb;
1051         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1052         struct ieee80211_local *local = sdata->local;
1053         struct cfg80211_bss *cbss;
1054         u16 capability;
1055         int active_ibss;
1056
1057         mutex_lock(&sdata->u.ibss.mtx);
1058
1059         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1060         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1061         sdata->u.ibss.ssid_len = 0;
1062
1063         active_ibss = ieee80211_sta_active_ibss(sdata);
1064
1065         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1066                 capability = WLAN_CAPABILITY_IBSS;
1067
1068                 if (ifibss->privacy)
1069                         capability |= WLAN_CAPABILITY_PRIVACY;
1070
1071                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1072                                         ifibss->bssid, ifibss->ssid,
1073                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1074                                         WLAN_CAPABILITY_PRIVACY,
1075                                         capability);
1076
1077                 if (cbss) {
1078                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
1079                         cfg80211_put_bss(cbss);
1080                 }
1081         }
1082
1083         sta_info_flush(sdata->local, sdata);
1084         netif_carrier_off(sdata->dev);
1085
1086         /* remove beacon */
1087         kfree(sdata->u.ibss.ie);
1088         skb = rcu_dereference_protected(sdata->u.ibss.presp,
1089                                         lockdep_is_held(&sdata->u.ibss.mtx));
1090         RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1091         sdata->vif.bss_conf.ibss_joined = false;
1092         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1093                                                 BSS_CHANGED_IBSS);
1094         synchronize_rcu();
1095         kfree_skb(skb);
1096
1097         skb_queue_purge(&sdata->skb_queue);
1098
1099         del_timer_sync(&sdata->u.ibss.timer);
1100
1101         mutex_unlock(&sdata->u.ibss.mtx);
1102
1103         mutex_lock(&local->mtx);
1104         ieee80211_recalc_idle(sdata->local);
1105         mutex_unlock(&local->mtx);
1106
1107         return 0;
1108 }