linux/net/mac80211/ibss.c
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   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
  38static 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
  62static 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
 195static 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
 207static 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 */
 365struct 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
 408static 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
 431static 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
 458static 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
 510static 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
 605static 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
 671static 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
 692static 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
 710static 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
 741static 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
 778static 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
 789void 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
 802int 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
 820int 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
 836int 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
 846int 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 */
 869void 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
 882ieee80211_rx_result
 883ieee80211_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}
 909