net/mac80211/ibss.c

   1 /*
   2  * IBSS mode implementation
   3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/rtnetlink.h>
  21 #include <net/mac80211.h>
  22 #include <asm/unaligned.h>
  23
  24 #include "ieee80211_i.h"
  25 #include "rate.h"
  26
  27 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
  28 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
  29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
  30
  31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
  32 #define IEEE80211_IBSS_MERGE_DELAY 0x400000
  33 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
  34
  35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
  36
  37
  38 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
  39                                         struct ieee80211_mgmt *mgmt,
  40                                         size_t len)
  41 {
  42         u16 auth_alg, auth_transaction, status_code;
  43
  44         if (len < 24 + 6)
  45                 return;
  46
  47         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
  48         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
  49         status_code = le16_to_cpu(mgmt->u.auth.status_code);
  50
  51         /*
  52          * IEEE 802.11 standard does not require authentication in IBSS
  53          * networks and most implementations do not seem to use it.
  54          * However, try to reply to authentication attempts if someone
  55          * has actually implemented this.
  56          */
  57         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
  58                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
  59                                     sdata->u.ibss.bssid, 0);
  60 }
  61
  62 static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
  63                                      const u8 *bssid, const int beacon_int,
  64                                      const int freq,
  65                                      const size_t supp_rates_len,
  66                                      const u8 *supp_rates,
  67                                      const u16 capability, u64 tsf)
  68 {
  69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
  70         struct ieee80211_local *local = sdata->local;
  71         int res = 0, rates, i, j;
  72         struct sk_buff *skb;
  73         struct ieee80211_mgmt *mgmt;
  74         u8 *pos;
  75         struct ieee80211_supported_band *sband;
  76         union iwreq_data wrqu;
  77
  78         if (local->ops->reset_tsf) {
  79                 /* Reset own TSF to allow time synchronization work. */
  80                 local->ops->reset_tsf(local_to_hw(local));
  81         }
  82
  83         if ((ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) &&
  84            memcmp(ifibss->bssid, bssid, ETH_ALEN) == 0)
  85                 return res;
  86
  87         skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
  88         if (!skb) {
  89                 printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
  90                        "response\n", sdata->dev->name);
  91                 return -ENOMEM;
  92         }
  93
  94         if (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) {
  95                 /* Remove possible STA entries from other IBSS networks. */
  96                 sta_info_flush_delayed(sdata);
  97         }
  98
  99         memcpy(ifibss->bssid, bssid, ETH_ALEN);
 100         res = ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID);
 101         if (res)
 102                 return res;
 103
 104         local->hw.conf.beacon_int = beacon_int >= 10 ? beacon_int : 10;
 105
 106         sdata->drop_unencrypted = capability &
 107                 WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 108
 109         res = ieee80211_set_freq(sdata, freq);
 110
 111         if (res)
 112                 return res;
 113
 114         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 115
 116         /* Build IBSS probe response */
 117
 118         skb_reserve(skb, local->hw.extra_tx_headroom);
 119
 120         mgmt = (struct ieee80211_mgmt *)
 121                 skb_put(skb, 24 + sizeof(mgmt->u.beacon));
 122         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
 123         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 124                                           IEEE80211_STYPE_PROBE_RESP);
 125         memset(mgmt->da, 0xff, ETH_ALEN);
 126         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 127         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
 128         mgmt->u.beacon.beacon_int =
 129                 cpu_to_le16(local->hw.conf.beacon_int);
 130         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
 131         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
 132
 133         pos = skb_put(skb, 2 + ifibss->ssid_len);
 134         *pos++ = WLAN_EID_SSID;
 135         *pos++ = ifibss->ssid_len;
 136         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
 137
 138         rates = supp_rates_len;
 139         if (rates > 8)
 140                 rates = 8;
 141         pos = skb_put(skb, 2 + rates);
 142         *pos++ = WLAN_EID_SUPP_RATES;
 143         *pos++ = rates;
 144         memcpy(pos, supp_rates, rates);
 145
 146         if (sband->band == IEEE80211_BAND_2GHZ) {
 147                 pos = skb_put(skb, 2 + 1);
 148                 *pos++ = WLAN_EID_DS_PARAMS;
 149                 *pos++ = 1;
 150                 *pos++ = ieee80211_frequency_to_channel(freq);
 151         }
 152
 153         pos = skb_put(skb, 2 + 2);
 154         *pos++ = WLAN_EID_IBSS_PARAMS;
 155         *pos++ = 2;
 156         /* FIX: set ATIM window based on scan results */
 157         *pos++ = 0;
 158         *pos++ = 0;
 159
 160         if (supp_rates_len > 8) {
 161                 rates = supp_rates_len - 8;
 162                 pos = skb_put(skb, 2 + rates);
 163                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 164                 *pos++ = rates;
 165                 memcpy(pos, &supp_rates[8], rates);
 166         }
 167
 168         ifibss->probe_resp = skb;
 169
 170         ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON |
 171                                    IEEE80211_IFCC_BEACON_ENABLED);
 172
 173
 174         rates = 0;
 175         for (i = 0; i < supp_rates_len; i++) {
 176                 int bitrate = (supp_rates[i] & 0x7f) * 5;
 177                 for (j = 0; j < sband->n_bitrates; j++)
 178                         if (sband->bitrates[j].bitrate == bitrate)
 179                                 rates |= BIT(j);
 180         }
 181
 182         ieee80211_sta_def_wmm_params(sdata, supp_rates_len, supp_rates);
 183
 184         ifibss->flags |= IEEE80211_IBSS_PREV_BSSID_SET;
 185         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
 186         mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);
 187
 188         memset(&wrqu, 0, sizeof(wrqu));
 189         memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
 190         wireless_send_event(sdata->dev, SIOCGIWAP, &wrqu, NULL);
 191
 192         return res;
 193 }
 194
 195 static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 196                                    struct ieee80211_bss *bss)
 197 {
 198         return __ieee80211_sta_join_ibss(sdata,
 199                                          bss->cbss.bssid,
 200                                          bss->cbss.beacon_interval,
 201                                          bss->cbss.channel->center_freq,
 202                                          bss->supp_rates_len, bss->supp_rates,
 203                                          bss->cbss.capability,
 204                                          bss->cbss.tsf);
 205 }
 206
 207 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 208                                   struct ieee80211_mgmt *mgmt,
 209                                   size_t len,
 210                                   struct ieee80211_rx_status *rx_status,
 211                                   struct ieee802_11_elems *elems,
 212                                   bool beacon)
 213 {
 214         struct ieee80211_local *local = sdata->local;
 215         int freq;
 216         struct ieee80211_bss *bss;
 217         struct sta_info *sta;
 218         struct ieee80211_channel *channel;
 219         u64 beacon_timestamp, rx_timestamp;
 220         u32 supp_rates = 0;
 221         enum ieee80211_band band = rx_status->band;
 222
 223         if (elems->ds_params && elems->ds_params_len == 1)
 224                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
 225         else
 226                 freq = rx_status->freq;
 227
 228         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 229
 230         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 231                 return;
 232
 233         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
 234             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
 235                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
 236
 237                 rcu_read_lock();
 238
 239                 sta = sta_info_get(local, mgmt->sa);
 240                 if (sta) {
 241                         u32 prev_rates;
 242
 243                         prev_rates = sta->sta.supp_rates[band];
 244                         /* make sure mandatory rates are always added */
 245                         sta->sta.supp_rates[band] = supp_rates |
 246                                 ieee80211_mandatory_rates(local, band);
 247
 248 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 249                         if (sta->sta.supp_rates[band] != prev_rates)
 250                                 printk(KERN_DEBUG "%s: updated supp_rates set "
 251                                     "for %pM based on beacon info (0x%llx | "
 252                                     "0x%llx -> 0x%llx)\n",
 253                                     sdata->dev->name,
 254                                     sta->sta.addr,
 255                                     (unsigned long long) prev_rates,
 256                                     (unsigned long long) supp_rates,
 257                                     (unsigned long long) sta->sta.supp_rates[band]);
 258 #endif
 259                 } else
 260                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 261
 262                 rcu_read_unlock();
 263         }
 264
 265         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
 266                                         channel, beacon);
 267         if (!bss)
 268                 return;
 269
 270         /* was just updated in ieee80211_bss_info_update */
 271         beacon_timestamp = bss->cbss.tsf;
 272
 273         /* check if we need to merge IBSS */
 274
 275         /* merge only on beacons (???) */
 276         if (!beacon)
 277                 goto put_bss;
 278
 279         /* we use a fixed BSSID */
 280         if (sdata->u.ibss.flags & IEEE80211_IBSS_BSSID_SET)
 281                 goto put_bss;
 282
 283         /* not an IBSS */
 284         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
 285                 goto put_bss;
 286
 287         /* different channel */
 288         if (bss->cbss.channel != local->oper_channel)
 289                 goto put_bss;
 290
 291         /* different SSID */
 292         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
 293             memcmp(elems->ssid, sdata->u.ibss.ssid,
 294                                 sdata->u.ibss.ssid_len))
 295                 goto put_bss;
 296
 297         /* same BSSID */
 298         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
 299                 goto put_bss;
 300
 301         if (rx_status->flag & RX_FLAG_TSFT) {
 302                 /*
 303                  * For correct IBSS merging we need mactime; since mactime is
 304                  * defined as the time the first data symbol of the frame hits
 305                  * the PHY, and the timestamp of the beacon is defined as "the
 306                  * time that the data symbol containing the first bit of the
 307                  * timestamp is transmitted to the PHY plus the transmitting
 308                  * STA's delays through its local PHY from the MAC-PHY
 309                  * interface to its interface with the WM" (802.11 11.1.2)
 310                  * - equals the time this bit arrives at the receiver - we have
 311                  * to take into account the offset between the two.
 312                  *
 313                  * E.g. at 1 MBit that means mactime is 192 usec earlier
 314                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 315                  */
 316                 int rate;
 317
 318                 if (rx_status->flag & RX_FLAG_HT)
 319                         rate = 65; /* TODO: HT rates */
 320                 else
 321                         rate = local->hw.wiphy->bands[band]->
 322                                 bitrates[rx_status->rate_idx].bitrate;
 323
 324                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 325         } else if (local && local->ops && local->ops->get_tsf)
 326                 /* second best option: get current TSF */
 327                 rx_timestamp = local->ops->get_tsf(local_to_hw(local));
 328         else
 329                 /* can't merge without knowing the TSF */
 330                 rx_timestamp = -1LLU;
 331
 332 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 333         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
 334                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
 335                mgmt->sa, mgmt->bssid,
 336                (unsigned long long)rx_timestamp,
 337                (unsigned long long)beacon_timestamp,
 338                (unsigned long long)(rx_timestamp - beacon_timestamp),
 339                jiffies);
 340 #endif
 341
 342         /* give slow hardware some time to do the TSF sync */
 343         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
 344                 goto put_bss;
 345
 346         if (beacon_timestamp > rx_timestamp) {
 347 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 348                 printk(KERN_DEBUG "%s: beacon TSF higher than "
 349                        "local TSF - IBSS merge with BSSID %pM\n",
 350                        sdata->dev->name, mgmt->bssid);
 351 #endif
 352                 ieee80211_sta_join_ibss(sdata, bss);
 353                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
 354         }
 355
 356  put_bss:
 357         ieee80211_rx_bss_put(local, bss);
 358 }
 359
 360 /*
 361  * Add a new IBSS station, will also be called by the RX code when,
 362  * in IBSS mode, receiving a frame from a yet-unknown station, hence
 363  * must be callable in atomic context.
 364  */
 365 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 366                                         u8 *bssid,u8 *addr, u32 supp_rates)
 367 {
 368         struct ieee80211_local *local = sdata->local;
 369         struct sta_info *sta;
 370         int band = local->hw.conf.channel->band;
 371
 372         /* TODO: Could consider removing the least recently used entry and
 373          * allow new one to be added. */
 374         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
 375                 if (net_ratelimit()) {
 376                         printk(KERN_DEBUG "%s: No room for a new IBSS STA "
 377                                "entry %pM\n", sdata->dev->name, addr);
 378                 }
 379                 return NULL;
 380         }
 381
 382         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
 383                 return NULL;
 384
 385 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 386         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
 387                wiphy_name(local->hw.wiphy), addr, sdata->dev->name);
 388 #endif
 389
 390         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 391         if (!sta)
 392                 return NULL;
 393
 394         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 395
 396         /* make sure mandatory rates are always added */
 397         sta->sta.supp_rates[band] = supp_rates |
 398                         ieee80211_mandatory_rates(local, band);
 399
 400         rate_control_rate_init(sta);
 401
 402         if (sta_info_insert(sta))
 403                 return NULL;
 404
 405         return sta;
 406 }
 407
 408 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 409 {
 410         struct ieee80211_local *local = sdata->local;
 411         int active = 0;
 412         struct sta_info *sta;
 413
 414         rcu_read_lock();
 415
 416         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 417                 if (sta->sdata == sdata &&
 418                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
 419                                jiffies)) {
 420                         active++;
 421                         break;
 422                 }
 423         }
 424
 425         rcu_read_unlock();
 426
 427         return active;
 428 }
 429
 430
 431 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 432 {
 433         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 434
 435         mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL);
 436
 437         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
 438         if (ieee80211_sta_active_ibss(sdata))
 439                 return;
 440
 441         if ((ifibss->flags & IEEE80211_IBSS_BSSID_SET) &&
 442             (!(ifibss->flags & IEEE80211_IBSS_AUTO_CHANNEL_SEL)))
 443                 return;
 444
 445         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
 446                "IBSS networks with same SSID (merge)\n", sdata->dev->name);
 447
 448         /* XXX maybe racy? */
 449         if (sdata->local->scan_req)
 450                 return;
 451
 452         memcpy(sdata->local->int_scan_req.ssids[0].ssid,
 453                ifibss->ssid, IEEE80211_MAX_SSID_LEN);
 454         sdata->local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len;
 455         ieee80211_request_scan(sdata, &sdata->local->int_scan_req);
 456 }
 457
 458 static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
 459 {
 460         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 461         struct ieee80211_local *local = sdata->local;
 462         struct ieee80211_supported_band *sband;
 463         u8 *pos;
 464         u8 bssid[ETH_ALEN];
 465         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
 466         u16 capability;
 467         int i;
 468
 469         if (ifibss->flags & IEEE80211_IBSS_BSSID_SET) {
 470                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
 471         } else {
 472                 /* Generate random, not broadcast, locally administered BSSID. Mix in
 473                  * own MAC address to make sure that devices that do not have proper
 474                  * random number generator get different BSSID. */
 475                 get_random_bytes(bssid, ETH_ALEN);
 476                 for (i = 0; i < ETH_ALEN; i++)
 477                         bssid[i] ^= sdata->dev->dev_addr[i];
 478                 bssid[0] &= ~0x01;
 479                 bssid[0] |= 0x02;
 480         }
 481
 482         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
 483                sdata->dev->name, bssid);
 484
 485         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 486
 487         if (local->hw.conf.beacon_int == 0)
 488                 local->hw.conf.beacon_int = 100;
 489
 490         capability = WLAN_CAPABILITY_IBSS;
 491
 492         if (sdata->default_key)
 493                 capability |= WLAN_CAPABILITY_PRIVACY;
 494         else
 495                 sdata->drop_unencrypted = 0;
 496
 497         pos = supp_rates;
 498         for (i = 0; i < sband->n_bitrates; i++) {
 499                 int rate = sband->bitrates[i].bitrate;
 500                 *pos++ = (u8) (rate / 5);
 501         }
 502
 503         return __ieee80211_sta_join_ibss(sdata,
 504                                          bssid, local->hw.conf.beacon_int,
 505                                          local->hw.conf.channel->center_freq,
 506                                          sband->n_bitrates, supp_rates,
 507                                          capability, 0);
 508 }
 509
 510 static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 511 {
 512         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 513         struct ieee80211_local *local = sdata->local;
 514         struct ieee80211_bss *bss;
 515         const u8 *bssid = NULL;
 516         int active_ibss;
 517
 518         if (ifibss->ssid_len == 0)
 519                 return -EINVAL;
 520
 521         active_ibss = ieee80211_sta_active_ibss(sdata);
 522 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 523         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
 524                sdata->dev->name, active_ibss);
 525 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 526
 527         if (active_ibss)
 528                 return 0;
 529
 530         if (ifibss->flags & IEEE80211_IBSS_BSSID_SET)
 531                 bssid = ifibss->bssid;
 532         bss = (void *)cfg80211_get_bss(local->hw.wiphy, NULL, bssid,
 533                                        ifibss->ssid, ifibss->ssid_len,
 534                                        WLAN_CAPABILITY_IBSS,
 535                                        WLAN_CAPABILITY_IBSS);
 536
 537 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 538         if (bss)
 539                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
 540                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
 541 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 542
 543         if (bss &&
 544             (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) ||
 545              memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN))) {
 546                 int ret;
 547
 548                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
 549                        " based on configured SSID\n",
 550                        sdata->dev->name, bss->cbss.bssid);
 551
 552                 ret = ieee80211_sta_join_ibss(sdata, bss);
 553                 ieee80211_rx_bss_put(local, bss);
 554                 return ret;
 555         } else if (bss)
 556                 ieee80211_rx_bss_put(local, bss);
 557
 558 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 559         printk(KERN_DEBUG "   did not try to join ibss\n");
 560 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 561
 562         /* Selected IBSS not found in current scan results - try to scan */
 563         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
 564             !ieee80211_sta_active_ibss(sdata)) {
 565                 mod_timer(&ifibss->timer, jiffies +
 566                                           IEEE80211_IBSS_MERGE_INTERVAL);
 567         } else if (time_after(jiffies, local->last_scan_completed +
 568                                         IEEE80211_SCAN_INTERVAL)) {
 569                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
 570                        "join\n", sdata->dev->name);
 571
 572                 /* XXX maybe racy? */
 573                 if (local->scan_req)
 574                         return -EBUSY;
 575
 576                 memcpy(local->int_scan_req.ssids[0].ssid,
 577                        ifibss->ssid, IEEE80211_MAX_SSID_LEN);
 578                 local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len;
 579                 return ieee80211_request_scan(sdata, &local->int_scan_req);
 580         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
 581                 int interval = IEEE80211_SCAN_INTERVAL;
 582
 583                 if (time_after(jiffies, ifibss->ibss_join_req +
 584                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
 585                         if (!(local->oper_channel->flags &
 586                                                 IEEE80211_CHAN_NO_IBSS))
 587                                 return ieee80211_sta_create_ibss(sdata);
 588                         printk(KERN_DEBUG "%s: IBSS not allowed on"
 589                                " %d MHz\n", sdata->dev->name,
 590                                local->hw.conf.channel->center_freq);
 591
 592                         /* No IBSS found - decrease scan interval and continue
 593                          * scanning. */
 594                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
 595                 }
 596
 597                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 598                 mod_timer(&ifibss->timer, jiffies + interval);
 599                 return 0;
 600         }
 601
 602         return 0;
 603 }
 604
 605 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
 606                                         struct ieee80211_mgmt *mgmt,
 607                                         size_t len)
 608 {
 609         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 610         struct ieee80211_local *local = sdata->local;
 611         int tx_last_beacon;
 612         struct sk_buff *skb;
 613         struct ieee80211_mgmt *resp;
 614         u8 *pos, *end;
 615
 616         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
 617             len < 24 + 2 || !ifibss->probe_resp)
 618                 return;
 619
 620         if (local->ops->tx_last_beacon)
 621                 tx_last_beacon = local->ops->tx_last_beacon(local_to_hw(local));
 622         else
 623                 tx_last_beacon = 1;
 624
 625 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 626         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
 627                " (tx_last_beacon=%d)\n",
 628                sdata->dev->name, mgmt->sa, mgmt->da,
 629                mgmt->bssid, tx_last_beacon);
 630 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 631
 632         if (!tx_last_beacon)
 633                 return;
 634
 635         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
 636             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
 637                 return;
 638
 639         end = ((u8 *) mgmt) + len;
 640         pos = mgmt->u.probe_req.variable;
 641         if (pos[0] != WLAN_EID_SSID ||
 642             pos + 2 + pos[1] > end) {
 643 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 644                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
 645                        "from %pM\n",
 646                        sdata->dev->name, mgmt->sa);
 647 #endif
 648                 return;
 649         }
 650         if (pos[1] != 0 &&
 651             (pos[1] != ifibss->ssid_len ||
 652              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len) != 0)) {
 653                 /* Ignore ProbeReq for foreign SSID */
 654                 return;
 655         }
 656
 657         /* Reply with ProbeResp */
 658         skb = skb_copy(ifibss->probe_resp, GFP_KERNEL);
 659         if (!skb)
 660                 return;
 661
 662         resp = (struct ieee80211_mgmt *) skb->data;
 663         memcpy(resp->da, mgmt->sa, ETH_ALEN);
 664 #ifdef CONFIG_MAC80211_IBSS_DEBUG
 665         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
 666                sdata->dev->name, resp->da);
 667 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
 668         ieee80211_tx_skb(sdata, skb, 0);
 669 }
 670
 671 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
 672                                          struct ieee80211_mgmt *mgmt,
 673                                          size_t len,
 674                                          struct ieee80211_rx_status *rx_status)
 675 {
 676         size_t baselen;
 677         struct ieee802_11_elems elems;
 678
 679         if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 680                 return; /* ignore ProbeResp to foreign address */
 681
 682         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 683         if (baselen > len)
 684                 return;
 685
 686         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 687                                 &elems);
 688
 689         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 690 }
 691
 692 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 693                                      struct ieee80211_mgmt *mgmt,
 694                                      size_t len,
 695                                      struct ieee80211_rx_status *rx_status)
 696 {
 697         size_t baselen;
 698         struct ieee802_11_elems elems;
 699
 700         /* Process beacon from the current BSS */
 701         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
 702         if (baselen > len)
 703                 return;
 704
 705         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 706
 707         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 708 }
 709
 710 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 711                                           struct sk_buff *skb)
 712 {
 713         struct ieee80211_rx_status *rx_status;
 714         struct ieee80211_mgmt *mgmt;
 715         u16 fc;
 716
 717         rx_status = (struct ieee80211_rx_status *) skb->cb;
 718         mgmt = (struct ieee80211_mgmt *) skb->data;
 719         fc = le16_to_cpu(mgmt->frame_control);
 720
 721         switch (fc & IEEE80211_FCTL_STYPE) {
 722         case IEEE80211_STYPE_PROBE_REQ:
 723                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
 724                 break;
 725         case IEEE80211_STYPE_PROBE_RESP:
 726                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
 727                                              rx_status);
 728                 break;
 729         case IEEE80211_STYPE_BEACON:
 730                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
 731                                          rx_status);
 732                 break;
 733         case IEEE80211_STYPE_AUTH:
 734                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
 735                 break;
 736         }
 737
 738         kfree_skb(skb);
 739 }
 740
 741 static void ieee80211_ibss_work(struct work_struct *work)
 742 {
 743         struct ieee80211_sub_if_data *sdata =
 744                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
 745         struct ieee80211_local *local = sdata->local;
 746         struct ieee80211_if_ibss *ifibss;
 747         struct sk_buff *skb;
 748
 749         if (!netif_running(sdata->dev))
 750                 return;
 751
 752         if (local->sw_scanning || local->hw_scanning)
 753                 return;
 754
 755         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
 756                 return;
 757         ifibss = &sdata->u.ibss;
 758
 759         while ((skb = skb_dequeue(&ifibss->skb_queue)))
 760                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
 761
 762         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
 763                 return;
 764
 765         switch (ifibss->state) {
 766         case IEEE80211_IBSS_MLME_SEARCH:
 767                 ieee80211_sta_find_ibss(sdata);
 768                 break;
 769         case IEEE80211_IBSS_MLME_JOINED:
 770                 ieee80211_sta_merge_ibss(sdata);
 771                 break;
 772         default:
 773                 WARN_ON(1);
 774                 break;
 775         }
 776 }
 777
 778 static void ieee80211_ibss_timer(unsigned long data)
 779 {
 780         struct ieee80211_sub_if_data *sdata =
 781                 (struct ieee80211_sub_if_data *) data;
 782         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 783         struct ieee80211_local *local = sdata->local;
 784
 785         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 786         queue_work(local->hw.workqueue, &ifibss->work);
 787 }
 788
 789 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 790 {
 791         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 792
 793         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
 794         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
 795                     (unsigned long) sdata);
 796         skb_queue_head_init(&ifibss->skb_queue);
 797
 798         ifibss->flags |= IEEE80211_IBSS_AUTO_BSSID_SEL |
 799                         IEEE80211_IBSS_AUTO_CHANNEL_SEL;
 800 }
 801
 802 int ieee80211_ibss_commit(struct ieee80211_sub_if_data *sdata)
 803 {
 804         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 805
 806         ifibss->flags &= ~IEEE80211_IBSS_PREV_BSSID_SET;
 807
 808         if (ifibss->ssid_len)
 809                 ifibss->flags |= IEEE80211_IBSS_SSID_SET;
 810         else
 811                 ifibss->flags &= ~IEEE80211_IBSS_SSID_SET;
 812
 813         ifibss->ibss_join_req = jiffies;
 814         ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 815         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
 816
 817         return 0;
 818 }
 819
 820 int ieee80211_ibss_set_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t len)
 821 {
 822         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 823
 824         if (len > IEEE80211_MAX_SSID_LEN)
 825                 return -EINVAL;
 826
 827         if (ifibss->ssid_len != len || memcmp(ifibss->ssid, ssid, len) != 0) {
 828                 memset(ifibss->ssid, 0, sizeof(ifibss->ssid));
 829                 memcpy(ifibss->ssid, ssid, len);
 830                 ifibss->ssid_len = len;
 831         }
 832
 833         return ieee80211_ibss_commit(sdata);
 834 }
 835
 836 int ieee80211_ibss_get_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t *len)
 837 {
 838         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 839
 840         memcpy(ssid, ifibss->ssid, ifibss->ssid_len);
 841         *len = ifibss->ssid_len;
 842
 843         return 0;
 844 }
 845
 846 int ieee80211_ibss_set_bssid(struct ieee80211_sub_if_data *sdata, u8 *bssid)
 847 {
 848         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 849
 850         if (is_valid_ether_addr(bssid)) {
 851                 memcpy(ifibss->bssid, bssid, ETH_ALEN);
 852                 ifibss->flags |= IEEE80211_IBSS_BSSID_SET;
 853         } else {
 854                 memset(ifibss->bssid, 0, ETH_ALEN);
 855                 ifibss->flags &= ~IEEE80211_IBSS_BSSID_SET;
 856         }
 857
 858         if (netif_running(sdata->dev)) {
 859                 if (ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID)) {
 860                         printk(KERN_DEBUG "%s: Failed to config new BSSID to "
 861                                "the low-level driver\n", sdata->dev->name);
 862                 }
 863         }
 864
 865         return ieee80211_ibss_commit(sdata);
 866 }
 867
 868 /* scan finished notification */
 869 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 870 {
 871         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 872         struct ieee80211_if_ibss *ifibss;
 873
 874         if (sdata && sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 875                 ifibss = &sdata->u.ibss;
 876                 if ((!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) ||
 877                     !ieee80211_sta_active_ibss(sdata))
 878                         ieee80211_sta_find_ibss(sdata);
 879         }
 880 }
 881
 882 ieee80211_rx_result
 883 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 884                        struct ieee80211_rx_status *rx_status)
 885 {
 886         struct ieee80211_local *local = sdata->local;
 887         struct ieee80211_mgmt *mgmt;
 888         u16 fc;
 889
 890         if (skb->len < 24)
 891                 return RX_DROP_MONITOR;
 892
 893         mgmt = (struct ieee80211_mgmt *) skb->data;
 894         fc = le16_to_cpu(mgmt->frame_control);
 895
 896         switch (fc & IEEE80211_FCTL_STYPE) {
 897         case IEEE80211_STYPE_PROBE_RESP:
 898         case IEEE80211_STYPE_BEACON:
 899                 memcpy(skb->cb, rx_status, sizeof(*rx_status));
 900         case IEEE80211_STYPE_PROBE_REQ:
 901         case IEEE80211_STYPE_AUTH:
 902                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
 903                 queue_work(local->hw.workqueue, &sdata->u.ibss.work);
 904                 return RX_QUEUED;
 905         }
 906
 907         return RX_DROP_MONITOR;
 908 }