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         lockdep_assert_held(&sdata->u.ibss.mtx);
  47
  48         if (len < 24 + 6)
  49                 return;
  50
  51         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  52         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  53         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  54
  55         /*
  56          * IEEE 802.11 standard does not require authentication in IBSS
  57          * networks and most implementations do not seem to use it.
  58          * However, try to reply to authentication attempts if someone
  59          * has actually implemented this.
  60          */
  61         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  62                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  63                                     sdata->u.ibss.bssid, NULL, 0, 0);
  64 }
  65
  66 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  67                                       const u8 *bssid, const int beacon_int,
  68                                       struct ieee80211_channel *chan,
  69                                       const u32 basic_rates,
  70                                       const u16 capability, u64 tsf)
  71 {
  72         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  73         struct ieee80211_local *local = sdata->local;
  74         int rates, i;
  75         struct sk_buff *skb;
  76         struct ieee80211_mgmt *mgmt;
  77         u8 *pos;
  78         struct ieee80211_supported_band *sband;
  79         struct cfg80211_bss *bss;
  80         u32 bss_change;
  81         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
  82
  83         lockdep_assert_held(&ifibss->mtx);
  84
  85         /* Reset own TSF to allow time synchronization work. */
  86         drv_reset_tsf(local);
  87
  88         skb = ifibss->skb;
  89         rcu_assign_pointer(ifibss->presp, NULL);
  90         synchronize_rcu();
  91         skb->data = skb->head;
  92         skb->len = 0;
  93         skb_reset_tail_pointer(skb);
  94         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
  95
  96         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
  97                 sta_info_flush(sdata->local, sdata);
  98
  99         /* if merging, indicate to driver that we leave the old IBSS */
 100         if (sdata->vif.bss_conf.ibss_joined) {
 101                 sdata->vif.bss_conf.ibss_joined = false;
 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         local->oper_channel = chan;
 110         WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
 111         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 112
 113         sband = local->hw.wiphy->bands[chan->band];
 114
 115         /* build supported rates array */
 116         pos = supp_rates;
 117         for (i = 0; i < sband->n_bitrates; i++) {
 118                 int rate = sband->bitrates[i].bitrate;
 119                 u8 basic = 0;
 120                 if (basic_rates & BIT(i))
 121                         basic = 0x80;
 122                 *pos++ = basic | (u8) (rate / 5);
 123         }
 124
 125         /* Build IBSS probe response */
 126         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 127         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 128         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 129                                           IEEE80211_STYPE_PROBE_RESP);
 130         memset(mgmt->da, 0xff, ETH_ALEN);
 131         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 132         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 133         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
 134         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 135         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 136
 137         pos = skb_put(skb, 2 + ifibss->ssid_len);
 138         *pos++ = WLAN_EID_SSID;
 139         *pos++ = ifibss->ssid_len;
 140         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 141
 142         rates = sband->n_bitrates;
 143         if (rates > 8)
 144                 rates = 8;
 145         pos = skb_put(skb, 2 + rates);
 146         *pos++ = WLAN_EID_SUPP_RATES;
 147         *pos++ = rates;
 148         memcpy(pos, supp_rates, rates);
 149
 150         if (sband->band == IEEE80211_BAND_2GHZ) {
 151                 pos = skb_put(skb, 2 + 1);
 152                 *pos++ = WLAN_EID_DS_PARAMS;
 153                 *pos++ = 1;
 154                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
 155         }
 156
 157         pos = skb_put(skb, 2 + 2);
 158         *pos++ = WLAN_EID_IBSS_PARAMS;
 159         *pos++ = 2;
 160         /* FIX: set ATIM window based on scan results */
 161         *pos++ = 0;
 162         *pos++ = 0;
 163
 164         if (sband->n_bitrates > 8) {
 165                 rates = sband->n_bitrates - 8;
 166                 pos = skb_put(skb, 2 + rates);
 167                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 168                 *pos++ = rates;
 169                 memcpy(pos, &supp_rates[8], rates);
 170         }
 171
 172         if (ifibss->ie_len)
 173                 memcpy(skb_put(skb, ifibss->ie_len),
 174                        ifibss->ie, ifibss->ie_len);
 175
 176         if (local->hw.queues >= 4) {
 177                 pos = skb_put(skb, 9);
 178                 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
 179                 *pos++ = 7; /* len */
 180                 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
 181                 *pos++ = 0x50;
 182                 *pos++ = 0xf2;
 183                 *pos++ = 2; /* WME */
 184                 *pos++ = 0; /* WME info */
 185                 *pos++ = 1; /* WME ver */
 186                 *pos++ = 0; /* U-APSD no in use */
 187         }
 188
 189         rcu_assign_pointer(ifibss->presp, skb);
 190
 191         sdata->vif.bss_conf.beacon_int = beacon_int;
 192         sdata->vif.bss_conf.basic_rates = basic_rates;
 193         bss_change = BSS_CHANGED_BEACON_INT;
 194         bss_change |= ieee80211_reset_erp_info(sdata);
 195         bss_change |= BSS_CHANGED_BSSID;
 196         bss_change |= BSS_CHANGED_BEACON;
 197         bss_change |= BSS_CHANGED_BEACON_ENABLED;
 198         bss_change |= BSS_CHANGED_BASIC_RATES;
 199         bss_change |= BSS_CHANGED_IBSS;
 200         sdata->vif.bss_conf.ibss_joined = true;
 201         ieee80211_bss_info_change_notify(sdata, bss_change);
 202
 203         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
 204
 205         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 206         mod_timer(&ifibss->timer,
 207                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 208
 209         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
 210                                         mgmt, skb->len, 0, GFP_KERNEL);
 211         cfg80211_put_bss(bss);
 212         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
 213 }
 214
 215 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 216                                     struct ieee80211_bss *bss)
 217 {
 218         struct cfg80211_bss *cbss =
 219                 container_of((void *)bss, struct cfg80211_bss, priv);
 220         struct ieee80211_supported_band *sband;
 221         u32 basic_rates;
 222         int i, j;
 223         u16 beacon_int = cbss->beacon_interval;
 224
 225         lockdep_assert_held(&sdata->u.ibss.mtx);
 226
 227         if (beacon_int < 10)
 228                 beacon_int = 10;
 229
 230         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 231
 232         basic_rates = 0;
 233
 234         for (i = 0; i < bss->supp_rates_len; i++) {
 235                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
 236                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
 237
 238                 for (j = 0; j < sband->n_bitrates; j++) {
 239                         if (sband->bitrates[j].bitrate == rate) {
 240                                 if (is_basic)
 241                                         basic_rates |= BIT(j);
 242                                 break;
 243                         }
 244                 }
 245         }
 246
 247         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
 248                                   beacon_int,
 249                                   cbss->channel,
 250                                   basic_rates,
 251                                   cbss->capability,
 252                                   cbss->tsf);
 253 }
 254
 255 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 256                                   struct ieee80211_mgmt *mgmt,
 257                                   size_t len,
 258                                   struct ieee80211_rx_status *rx_status,
 259                                   struct ieee802_11_elems *elems,
 260                                   bool beacon)
 261 {
 262         struct ieee80211_local *local = sdata->local;
 263         int freq;
 264         struct cfg80211_bss *cbss;
 265         struct ieee80211_bss *bss;
 266         struct sta_info *sta;
 267         struct ieee80211_channel *channel;
 268         u64 beacon_timestamp, rx_timestamp;
 269         u32 supp_rates = 0;
 270         enum ieee80211_band band = rx_status->band;
 271
 272         if (elems->ds_params && elems->ds_params_len == 1)
 273                 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
 274                                                       band);
 275         else
 276                 freq = rx_status->freq;
 277
 278         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 279
 280         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 281                 return;
 282
 283         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 284             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 285
 286                 rcu_read_lock();
 287                 sta = sta_info_get(sdata, mgmt->sa);
 288
 289                 if (elems->supp_rates) {
 290                         supp_rates = ieee80211_sta_get_rates(local, elems,
 291                                                              band);
 292                         if (sta) {
 293                                 u32 prev_rates;
 294
 295                                 prev_rates = sta->sta.supp_rates[band];
 296                                 /* make sure mandatory rates are always added */
 297                                 sta->sta.supp_rates[band] = supp_rates |
 298                                         ieee80211_mandatory_rates(local, band);
 299
 300                                 if (sta->sta.supp_rates[band] != prev_rates) {
 301 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 302                                         printk(KERN_DEBUG
 303                                                 "%s: updated supp_rates set "
 304                                                 "for %pM based on beacon"
 305                                                 "/probe_resp (0x%x -> 0x%x)\n",
 306                                                 sdata->name, sta->sta.addr,
 307                                                 prev_rates,
 308                                                 sta->sta.supp_rates[band]);
 309 #endif
 310                                         rate_control_rate_init(sta);
 311                                 }
 312                         } else
 313                                 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
 314                                                 mgmt->sa, supp_rates,
 315                                                 GFP_ATOMIC);
 316                 }
 317
 318                 if (sta && elems->wmm_info)
 319                         set_sta_flags(sta, WLAN_STA_WME);
 320
 321                 rcu_read_unlock();
 322         }
 323
 324         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 325                                         channel, beacon);
 326         if (!bss)
 327                 return;
 328
 329         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
 330
 331         /* was just updated in ieee80211_bss_info_update */
 332         beacon_timestamp = cbss->tsf;
 333
 334         /* check if we need to merge IBSS */
 335
 336         /* we use a fixed BSSID */
 337         if (sdata->u.ibss.fixed_bssid)
 338                 goto put_bss;
 339
 340         /* not an IBSS */
 341         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
 342                 goto put_bss;
 343
 344         /* different channel */
 345         if (cbss->channel != local->oper_channel)
 346                 goto put_bss;
 347
 348         /* different SSID */
 349         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 350             memcmp(elems->ssid, sdata->u.ibss.ssid,
 351                                 sdata->u.ibss.ssid_len))
 352                 goto put_bss;
 353
 354         /* same BSSID */
 355         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 356                 goto put_bss;
 357
 358         if (rx_status->flag & RX_FLAG_TSFT) {
 359                 /*
 360                  * For correct IBSS merging we need mactime; since mactime is
 361                  * defined as the time the first data symbol of the frame hits
 362                  * the PHY, and the timestamp of the beacon is defined as "the
 363                  * time that the data symbol containing the first bit of the
 364                  * timestamp is transmitted to the PHY plus the transmitting
 365                  * STA's delays through its local PHY from the MAC-PHY
 366                  * interface to its interface with the WM" (802.11 11.1.2)
 367                  * - equals the time this bit arrives at the receiver - we have
 368                  * to take into account the offset between the two.
 369                  *
 370                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 371                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 372                  */
 373                 int rate;
 374
 375                 if (rx_status->flag & RX_FLAG_HT)
 376                         rate = 65; /* TODO: HT rates */
 377                 else
 378                         rate = local->hw.wiphy->bands[band]->
 379                                 bitrates[rx_status->rate_idx].bitrate;
 380
 381                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 382         } else {
 383                 /*
 384                  * second best option: get current TSF
 385                  * (will return -1 if not supported)
 386                  */
 387                 rx_timestamp = drv_get_tsf(local);
 388         }
 389
 390 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 391         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 392                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 393                mgmt->sa, mgmt->bssid,
 394                (unsigned long long)rx_timestamp,
 395                (unsigned long long)beacon_timestamp,
 396                (unsigned long long)(rx_timestamp - beacon_timestamp),
 397                jiffies);
 398 #endif
 399
 400         /* give slow hardware some time to do the TSF sync */
 401         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 402                 goto put_bss;
 403
 404         if (beacon_timestamp > rx_timestamp) {
 405 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 406                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 407                        "local TSF - IBSS merge with BSSID %pM\n",
 408                        sdata->name, mgmt->bssid);
 409 #endif
 410                 ieee80211_sta_join_ibss(sdata, bss);
 411                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 412                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
 413                                        supp_rates, GFP_KERNEL);
 414         }
 415
 416  put_bss:
 417         ieee80211_rx_bss_put(local, bss);
 418 }
 419
 420 /*
 421  * Add a new IBSS station, will also be called by the RX code when,
 422  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 423  * must be callable in atomic context.
 424  */
 425 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 426                                         u8 *bssid,u8 *addr, u32 supp_rates,
 427                                         gfp_t gfp)
 428 {
 429         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 430         struct ieee80211_local *local = sdata->local;
 431         struct sta_info *sta;
 432         int band = local->hw.conf.channel->band;
 433
 434         /*
 435          * XXX: Consider removing the least recently used entry and
 436          *      allow new one to be added.
 437          */
 438         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 439                 if (net_ratelimit())
 440                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
 441                                sdata->name, addr);
 442                 return NULL;
 443         }
 444
 445         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
 446                 return NULL;
 447
 448         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 449                 return NULL;
 450
 451 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 452         wiphy_debug(local->hw.wiphy, "Adding new IBSS station %pM (dev=%s)\n",
 453                     addr, sdata->name);
 454 #endif
 455
 456         sta = sta_info_alloc(sdata, addr, gfp);
 457         if (!sta)
 458                 return NULL;
 459
 460         sta->last_rx = jiffies;
 461         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 462
 463         /* make sure mandatory rates are always added */
 464         sta->sta.supp_rates[band] = supp_rates |
 465                         ieee80211_mandatory_rates(local, band);
 466
 467         rate_control_rate_init(sta);
 468
 469         /* If it fails, maybe we raced another insertion? */
 470         if (sta_info_insert(sta))
 471                 return sta_info_get(sdata, addr);
 472         return sta;
 473 }
 474
 475 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 476 {
 477         struct ieee80211_local *local = sdata->local;
 478         int active = 0;
 479         struct sta_info *sta;
 480
 481         lockdep_assert_held(&sdata->u.ibss.mtx);
 482
 483         rcu_read_lock();
 484
 485         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 486                 if (sta->sdata == sdata &&
 487                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 488                                jiffies)) {
 489                         active++;
 490                         break;
 491                 }
 492         }
 493
 494         rcu_read_unlock();
 495
 496         return active;
 497 }
 498
 499 /*
 500  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 501  */
 502
 503 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 504 {
 505         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 506
 507         lockdep_assert_held(&ifibss->mtx);
 508
 509         mod_timer(&ifibss->timer,
 510                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
 511
 512         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 513
 514         if (time_before(jiffies, ifibss->last_scan_completed +
 515                        IEEE80211_IBSS_MERGE_INTERVAL))
 516                 return;
 517
 518         if (ieee80211_sta_active_ibss(sdata))
 519                 return;
 520
 521         if (ifibss->fixed_channel)
 522                 return;
 523
 524         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 525                "IBSS networks with same SSID (merge)\n", sdata->name);
 526
 527         ieee80211_request_internal_scan(sdata,
 528                         ifibss->ssid, ifibss->ssid_len,
 529                         ifibss->fixed_channel ? ifibss->channel : NULL);
 530 }
 531
 532 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 533 {
 534         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 535         struct ieee80211_local *local = sdata->local;
 536         struct ieee80211_supported_band *sband;
 537         u8 bssid[ETH_ALEN];
 538         u16 capability;
 539         int i;
 540
 541         lockdep_assert_held(&ifibss->mtx);
 542
 543         if (ifibss->fixed_bssid) {
 544                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 545         } else {
 546                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 547                  * own MAC address to make sure that devices that do not have proper
 548                  * random number generator get different BSSID. */
 549                 get_random_bytes(bssid, ETH_ALEN);
 550                 for (i = 0; i < ETH_ALEN; i++)
 551                         bssid[i] ^= sdata->vif.addr[i];
 552                 bssid[0] &= ~0x01;
 553                 bssid[0] |= 0x02;
 554         }
 555
 556         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 557                sdata->name, bssid);
 558
 559         sband = local->hw.wiphy->bands[ifibss->channel->band];
 560
 561         capability = WLAN_CAPABILITY_IBSS;
 562
 563         if (ifibss->privacy)
 564                 capability |= WLAN_CAPABILITY_PRIVACY;
 565         else
 566                 sdata->drop_unencrypted = 0;
 567
 568         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
 569                                   ifibss->channel, ifibss->basic_rates,
 570                                   capability, 0);
 571 }
 572
 573 /*
 574  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 575  */
 576
 577 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 578 {
 579         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 580         struct ieee80211_local *local = sdata->local;
 581         struct cfg80211_bss *cbss;
 582         struct ieee80211_channel *chan = NULL;
 583         const u8 *bssid = NULL;
 584         int active_ibss;
 585         u16 capability;
 586
 587         lockdep_assert_held(&ifibss->mtx);
 588
 589         active_ibss = ieee80211_sta_active_ibss(sdata);
 590 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 591         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 592                sdata->name, active_ibss);
 593 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 594
 595         if (active_ibss)
 596                 return;
 597
 598         capability = WLAN_CAPABILITY_IBSS;
 599         if (ifibss->privacy)
 600                 capability |= WLAN_CAPABILITY_PRIVACY;
 601         if (ifibss->fixed_bssid)
 602                 bssid = ifibss->bssid;
 603         if (ifibss->fixed_channel)
 604                 chan = ifibss->channel;
 605         if (!is_zero_ether_addr(ifibss->bssid))
 606                 bssid = ifibss->bssid;
 607         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
 608                                 ifibss->ssid, ifibss->ssid_len,
 609                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
 610                                 capability);
 611
 612         if (cbss) {
 613                 struct ieee80211_bss *bss;
 614
 615                 bss = (void *)cbss->priv;
 616 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 617                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 618                        "%pM\n", cbss->bssid, ifibss->bssid);
 619 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 620
 621                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 622                        " based on configured SSID\n",
 623                        sdata->name, cbss->bssid);
 624
 625                 ieee80211_sta_join_ibss(sdata, bss);
 626                 ieee80211_rx_bss_put(local, bss);
 627                 return;
 628         }
 629
 630 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 631         printk(KERN_DEBUG "   did not try to join ibss\n");
 632 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 633
 634         /* Selected IBSS not found in current scan results - try to scan */
 635         if (time_after(jiffies, ifibss->last_scan_completed +
 636                                         IEEE80211_SCAN_INTERVAL)) {
 637                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 638                        "join\n", sdata->name);
 639
 640                 ieee80211_request_internal_scan(sdata,
 641                                 ifibss->ssid, ifibss->ssid_len,
 642                                 ifibss->fixed_channel ? ifibss->channel : NULL);
 643         } else {
 644                 int interval = IEEE80211_SCAN_INTERVAL;
 645
 646                 if (time_after(jiffies, ifibss->ibss_join_req +
 647                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 648                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
 649                                 ieee80211_sta_create_ibss(sdata);
 650                                 return;
 651                         }
 652                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 653                                " %d MHz\n", sdata->name,
 654                                local->hw.conf.channel->center_freq);
 655
 656                         /* No IBSS found - decrease scan interval and continue
 657                          * scanning. */
 658                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 659                 }
 660
 661                 mod_timer(&ifibss->timer,
 662                           round_jiffies(jiffies + interval));
 663         }
 664 }
 665
 666 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 667                                         struct sk_buff *req)
 668 {
 669         struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(req);
 670         struct ieee80211_mgmt *mgmt = (void *)req->data;
 671         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 672         struct ieee80211_local *local = sdata->local;
 673         int tx_last_beacon, len = req->len;
 674         struct sk_buff *skb;
 675         struct ieee80211_mgmt *resp;
 676         u8 *pos, *end;
 677
 678         lockdep_assert_held(&ifibss->mtx);
 679
 680         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 681             len < 24 + 2 || !ifibss->presp)
 682                 return;
 683
 684         tx_last_beacon = drv_tx_last_beacon(local);
 685
 686 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 687         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 688                " (tx_last_beacon=%d)\n",
 689                sdata->name, mgmt->sa, mgmt->da,
 690                mgmt->bssid, tx_last_beacon);
 691 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 692
 693         if (!tx_last_beacon && !(rx_status->rx_flags & IEEE80211_RX_RA_MATCH))
 694                 return;
 695
 696         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 697             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 698                 return;
 699
 700         end = ((u8 *) mgmt) + len;
 701         pos = mgmt->u.probe_req.variable;
 702         if (pos[0] != WLAN_EID_SSID ||
 703             pos + 2 + pos[1] > end) {
 704 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 705                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 706                        "from %pM\n",
 707                        sdata->name, mgmt->sa);
 708 #endif
 709                 return;
 710         }
 711         if (pos[1] != 0 &&
 712             (pos[1] != ifibss->ssid_len ||
 713              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
 714                 /* Ignore ProbeReq for foreign SSID */
 715                 return;
 716         }
 717
 718         /* Reply with ProbeResp */
 719         skb = skb_copy(ifibss->presp, GFP_KERNEL);
 720         if (!skb)
 721                 return;
 722
 723         resp = (struct ieee80211_mgmt *) skb->data;
 724         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 725 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 726         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 727                sdata->name, resp->da);
 728 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 729         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 730         ieee80211_tx_skb(sdata, skb);
 731 }
 732
 733 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 734                                          struct ieee80211_mgmt *mgmt,
 735                                          size_t len,
 736                                          struct ieee80211_rx_status *rx_status)
 737 {
 738         size_t baselen;
 739         struct ieee802_11_elems elems;
 740
 741         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
 742                 return; /* ignore ProbeResp to foreign address */
 743
 744         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 745         if (baselen > len)
 746                 return;
 747
 748         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 749                                 &elems);
 750
 751         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 752 }
 753
 754 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 755                                      struct ieee80211_mgmt *mgmt,
 756                                      size_t len,
 757                                      struct ieee80211_rx_status *rx_status)
 758 {
 759         size_t baselen;
 760         struct ieee802_11_elems elems;
 761
 762         /* Process beacon from the current BSS */
 763         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 764         if (baselen > len)
 765                 return;
 766
 767         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 768
 769         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 770 }
 771
 772 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 773                                    struct sk_buff *skb)
 774 {
 775         struct ieee80211_rx_status *rx_status;
 776         struct ieee80211_mgmt *mgmt;
 777         u16 fc;
 778
 779         rx_status = IEEE80211_SKB_RXCB(skb);
 780         mgmt = (struct ieee80211_mgmt *) skb->data;
 781         fc = le16_to_cpu(mgmt->frame_control);
 782
 783         mutex_lock(&sdata->u.ibss.mtx);
 784
 785         if (!sdata->u.ibss.ssid_len)
 786                 goto mgmt_out; /* not ready to merge yet */
 787
 788         switch (fc & IEEE80211_FCTL_STYPE) {
 789         case IEEE80211_STYPE_PROBE_REQ:
 790                 ieee80211_rx_mgmt_probe_req(sdata, skb);
 791                 break;
 792         case IEEE80211_STYPE_PROBE_RESP:
 793                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 794                                              rx_status);
 795                 break;
 796         case IEEE80211_STYPE_BEACON:
 797                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 798                                          rx_status);
 799                 break;
 800         case IEEE80211_STYPE_AUTH:
 801                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 802                 break;
 803         }
 804
 805  mgmt_out:
 806         mutex_unlock(&sdata->u.ibss.mtx);
 807 }
 808
 809 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 810 {
 811         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 812
 813         mutex_lock(&ifibss->mtx);
 814
 815         /*
 816          * Work could be scheduled after scan or similar
 817          * when we aren't even joined (or trying) with a
 818          * network.
 819          */
 820         if (!ifibss->ssid_len)
 821                 goto out;
 822
 823         switch (ifibss->state) {
 824         case IEEE80211_IBSS_MLME_SEARCH:
 825                 ieee80211_sta_find_ibss(sdata);
 826                 break;
 827         case IEEE80211_IBSS_MLME_JOINED:
 828                 ieee80211_sta_merge_ibss(sdata);
 829                 break;
 830         default:
 831                 WARN_ON(1);
 832                 break;
 833         }
 834
 835  out:
 836         mutex_unlock(&ifibss->mtx);
 837 }
 838
 839 static void ieee80211_ibss_timer(unsigned long data)
 840 {
 841         struct ieee80211_sub_if_data *sdata =
 842                 (struct ieee80211_sub_if_data *) data;
 843         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 844         struct ieee80211_local *local = sdata->local;
 845
 846         if (local->quiescing) {
 847                 ifibss->timer_running = true;
 848                 return;
 849         }
 850
 851         ieee80211_queue_work(&local->hw, &sdata->work);
 852 }
 853
 854 #ifdef CONFIG_PM
 855 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
 856 {
 857         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 858
 859         if (del_timer_sync(&ifibss->timer))
 860                 ifibss->timer_running = true;
 861 }
 862
 863 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
 864 {
 865         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 866
 867         if (ifibss->timer_running) {
 868                 add_timer(&ifibss->timer);
 869                 ifibss->timer_running = false;
 870         }
 871 }
 872 #endif
 873
 874 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 875 {
 876         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 877
 878         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 879                     (unsigned long) sdata);
 880         mutex_init(&ifibss->mtx);
 881 }
 882
 883 /* scan finished notification */
 884 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 885 {
 886         struct ieee80211_sub_if_data *sdata;
 887
 888         mutex_lock(&local->iflist_mtx);
 889         list_for_each_entry(sdata, &local->interfaces, list) {
 890                 if (!ieee80211_sdata_running(sdata))
 891                         continue;
 892                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
 893                         continue;
 894                 sdata->u.ibss.last_scan_completed = jiffies;
 895                 ieee80211_queue_work(&local->hw, &sdata->work);
 896         }
 897         mutex_unlock(&local->iflist_mtx);
 898 }
 899
 900 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 901                         struct cfg80211_ibss_params *params)
 902 {
 903         struct sk_buff *skb;
 904
 905         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
 906                             36 /* bitrates */ +
 907                             34 /* SSID */ +
 908                             3  /* DS params */ +
 909                             4  /* IBSS params */ +
 910                             params->ie_len);
 911         if (!skb)
 912                 return -ENOMEM;
 913
 914         mutex_lock(&sdata->u.ibss.mtx);
 915
 916         if (params->bssid) {
 917                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
 918                 sdata->u.ibss.fixed_bssid = true;
 919         } else
 920                 sdata->u.ibss.fixed_bssid = false;
 921
 922         sdata->u.ibss.privacy = params->privacy;
 923         sdata->u.ibss.basic_rates = params->basic_rates;
 924         memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
 925                sizeof(params->mcast_rate));
 926
 927         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 928
 929         sdata->u.ibss.channel = params->channel;
 930         sdata->u.ibss.fixed_channel = params->channel_fixed;
 931
 932         /* fix ourselves to that channel now already */
 933         if (params->channel_fixed) {
 934                 sdata->local->oper_channel = params->channel;
 935                 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
 936                                                     NL80211_CHAN_NO_HT));
 937         }
 938
 939         if (params->ie) {
 940                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 941                                            GFP_KERNEL);
 942                 if (sdata->u.ibss.ie)
 943                         sdata->u.ibss.ie_len = params->ie_len;
 944         }
 945
 946         sdata->u.ibss.skb = skb;
 947         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
 948         sdata->u.ibss.ibss_join_req = jiffies;
 949
 950         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
 951         sdata->u.ibss.ssid_len = params->ssid_len;
 952
 953         mutex_unlock(&sdata->u.ibss.mtx);
 954
 955         mutex_lock(&sdata->local->mtx);
 956         ieee80211_recalc_idle(sdata->local);
 957         mutex_unlock(&sdata->local->mtx);
 958
 959         ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 960
 961         return 0;
 962 }
 963
 964 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 965 {
 966         struct sk_buff *skb;
 967         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 968         struct ieee80211_local *local = sdata->local;
 969         struct cfg80211_bss *cbss;
 970         u16 capability;
 971         int active_ibss;
 972
 973         mutex_lock(&sdata->u.ibss.mtx);
 974
 975         active_ibss = ieee80211_sta_active_ibss(sdata);
 976
 977         if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
 978                 capability = WLAN_CAPABILITY_IBSS;
 979
 980                 if (ifibss->privacy)
 981                         capability |= WLAN_CAPABILITY_PRIVACY;
 982
 983                 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
 984                                         ifibss->bssid, ifibss->ssid,
 985                                         ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
 986                                         WLAN_CAPABILITY_PRIVACY,
 987                                         capability);
 988
 989                 if (cbss) {
 990                         cfg80211_unlink_bss(local->hw.wiphy, cbss);
 991                         cfg80211_put_bss(cbss);
 992                 }
 993         }
 994
 995         sta_info_flush(sdata->local, sdata);
 996
 997         /* remove beacon */
 998         kfree(sdata->u.ibss.ie);
 999         skb = sdata->u.ibss.presp;
1000         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
1001         sdata->vif.bss_conf.ibss_joined = false;
1002         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1003                                                 BSS_CHANGED_IBSS);
1004         synchronize_rcu();
1005         kfree_skb(skb);
1006
1007         skb_queue_purge(&sdata->skb_queue);
1008         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1009         sdata->u.ibss.ssid_len = 0;
1010
1011         del_timer_sync(&sdata->u.ibss.timer);
1012
1013         mutex_unlock(&sdata->u.ibss.mtx);
1014
1015         mutex_lock(&local->mtx);
1016         ieee80211_recalc_idle(sdata->local);
1017         mutex_unlock(&local->mtx);
1018
1019         return 0;
1020 }