SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/mac80211/scan.c

   1 /*
   2  * Scanning implementation
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2004, Instant802 Networks, Inc.
   6  * Copyright 2005, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.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 /* TODO:
  16  * order BSS list by RSSI(?) ("quality of AP")
  17  * scan result table filtering (by capability (privacy, IBSS/BSS, WPA/RSN IE,
  18  *    SSID)
  19  */
  20
  21 #include <linux/wireless.h>
  22 #include <linux/if_arp.h>
  23 #include <linux/rtnetlink.h>
  24 #include <net/mac80211.h>
  25 #include <net/iw_handler.h>
  26
  27 #include "ieee80211_i.h"
  28 #include "mesh.h"
  29
  30 #define IEEE80211_PROBE_DELAY (HZ / 33)
  31 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  32 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
  33
  34 void ieee80211_rx_bss_list_init(struct ieee80211_local *local)
  35 {
  36         spin_lock_init(&local->bss_lock);
  37         INIT_LIST_HEAD(&local->bss_list);
  38 }
  39
  40 void ieee80211_rx_bss_list_deinit(struct ieee80211_local *local)
  41 {
  42         struct ieee80211_bss *bss, *tmp;
  43
  44         list_for_each_entry_safe(bss, tmp, &local->bss_list, list)
  45                 ieee80211_rx_bss_put(local, bss);
  46 }
  47
  48 struct ieee80211_bss *
  49 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
  50                      u8 *ssid, u8 ssid_len)
  51 {
  52         struct ieee80211_bss *bss;
  53
  54         spin_lock_bh(&local->bss_lock);
  55         bss = local->bss_hash[STA_HASH(bssid)];
  56         while (bss) {
  57                 if (!bss_mesh_cfg(bss) &&
  58                     !memcmp(bss->bssid, bssid, ETH_ALEN) &&
  59                     bss->freq == freq &&
  60                     bss->ssid_len == ssid_len &&
  61                     (ssid_len == 0 || !memcmp(bss->ssid, ssid, ssid_len))) {
  62                         atomic_inc(&bss->users);
  63                         break;
  64                 }
  65                 bss = bss->hnext;
  66         }
  67         spin_unlock_bh(&local->bss_lock);
  68         return bss;
  69 }
  70
  71 /* Caller must hold local->bss_lock */
  72 static void __ieee80211_rx_bss_hash_add(struct ieee80211_local *local,
  73                                         struct ieee80211_bss *bss)
  74 {
  75         u8 hash_idx;
  76
  77         if (bss_mesh_cfg(bss))
  78                 hash_idx = mesh_id_hash(bss_mesh_id(bss),
  79                                         bss_mesh_id_len(bss));
  80         else
  81                 hash_idx = STA_HASH(bss->bssid);
  82
  83         bss->hnext = local->bss_hash[hash_idx];
  84         local->bss_hash[hash_idx] = bss;
  85 }
  86
  87 /* Caller must hold local->bss_lock */
  88 static void __ieee80211_rx_bss_hash_del(struct ieee80211_local *local,
  89                                         struct ieee80211_bss *bss)
  90 {
  91         struct ieee80211_bss *b, *prev = NULL;
  92         b = local->bss_hash[STA_HASH(bss->bssid)];
  93         while (b) {
  94                 if (b == bss) {
  95                         if (!prev)
  96                                 local->bss_hash[STA_HASH(bss->bssid)] =
  97                                         bss->hnext;
  98                         else
  99                                 prev->hnext = bss->hnext;
 100                         break;
 101                 }
 102                 prev = b;
 103                 b = b->hnext;
 104         }
 105 }
 106
 107 struct ieee80211_bss *
 108 ieee80211_rx_bss_add(struct ieee80211_local *local, u8 *bssid, int freq,
 109                      u8 *ssid, u8 ssid_len)
 110 {
 111         struct ieee80211_bss *bss;
 112
 113         bss = kzalloc(sizeof(*bss), GFP_ATOMIC);
 114         if (!bss)
 115                 return NULL;
 116         atomic_set(&bss->users, 2);
 117         memcpy(bss->bssid, bssid, ETH_ALEN);
 118         bss->freq = freq;
 119         if (ssid && ssid_len <= IEEE80211_MAX_SSID_LEN) {
 120                 memcpy(bss->ssid, ssid, ssid_len);
 121                 bss->ssid_len = ssid_len;
 122         }
 123
 124         spin_lock_bh(&local->bss_lock);
 125         /* TODO: order by RSSI? */
 126         list_add_tail(&bss->list, &local->bss_list);
 127         __ieee80211_rx_bss_hash_add(local, bss);
 128         spin_unlock_bh(&local->bss_lock);
 129         return bss;
 130 }
 131
 132 #ifdef CONFIG_MAC80211_MESH
 133 static struct ieee80211_bss *
 134 ieee80211_rx_mesh_bss_get(struct ieee80211_local *local, u8 *mesh_id, int mesh_id_len,
 135                           u8 *mesh_cfg, int freq)
 136 {
 137         struct ieee80211_bss *bss;
 138
 139         spin_lock_bh(&local->bss_lock);
 140         bss = local->bss_hash[mesh_id_hash(mesh_id, mesh_id_len)];
 141         while (bss) {
 142                 if (bss_mesh_cfg(bss) &&
 143                     !memcmp(bss_mesh_cfg(bss), mesh_cfg, MESH_CFG_CMP_LEN) &&
 144                     bss->freq == freq &&
 145                     mesh_id_len == bss->mesh_id_len &&
 146                     (mesh_id_len == 0 || !memcmp(bss->mesh_id, mesh_id,
 147                                                  mesh_id_len))) {
 148                         atomic_inc(&bss->users);
 149                         break;
 150                 }
 151                 bss = bss->hnext;
 152         }
 153         spin_unlock_bh(&local->bss_lock);
 154         return bss;
 155 }
 156
 157 static struct ieee80211_bss *
 158 ieee80211_rx_mesh_bss_add(struct ieee80211_local *local, u8 *mesh_id, int mesh_id_len,
 159                           u8 *mesh_cfg, int mesh_config_len, int freq)
 160 {
 161         struct ieee80211_bss *bss;
 162
 163         if (mesh_config_len != IEEE80211_MESH_CONFIG_LEN)
 164                 return NULL;
 165
 166         bss = kzalloc(sizeof(*bss), GFP_ATOMIC);
 167         if (!bss)
 168                 return NULL;
 169
 170         bss->mesh_cfg = kmalloc(MESH_CFG_CMP_LEN, GFP_ATOMIC);
 171         if (!bss->mesh_cfg) {
 172                 kfree(bss);
 173                 return NULL;
 174         }
 175
 176         if (mesh_id_len && mesh_id_len <= IEEE80211_MAX_MESH_ID_LEN) {
 177                 bss->mesh_id = kmalloc(mesh_id_len, GFP_ATOMIC);
 178                 if (!bss->mesh_id) {
 179                         kfree(bss->mesh_cfg);
 180                         kfree(bss);
 181                         return NULL;
 182                 }
 183                 memcpy(bss->mesh_id, mesh_id, mesh_id_len);
 184         }
 185
 186         atomic_set(&bss->users, 2);
 187         memcpy(bss->mesh_cfg, mesh_cfg, MESH_CFG_CMP_LEN);
 188         bss->mesh_id_len = mesh_id_len;
 189         bss->freq = freq;
 190         spin_lock_bh(&local->bss_lock);
 191         /* TODO: order by RSSI? */
 192         list_add_tail(&bss->list, &local->bss_list);
 193         __ieee80211_rx_bss_hash_add(local, bss);
 194         spin_unlock_bh(&local->bss_lock);
 195         return bss;
 196 }
 197 #endif
 198
 199 static void ieee80211_rx_bss_free(struct ieee80211_bss *bss)
 200 {
 201         kfree(bss->ies);
 202         kfree(bss_mesh_id(bss));
 203         kfree(bss_mesh_cfg(bss));
 204         kfree(bss);
 205 }
 206
 207 void ieee80211_rx_bss_put(struct ieee80211_local *local,
 208                           struct ieee80211_bss *bss)
 209 {
 210         local_bh_disable();
 211         if (!atomic_dec_and_lock(&bss->users, &local->bss_lock)) {
 212                 local_bh_enable();
 213                 return;
 214         }
 215
 216         __ieee80211_rx_bss_hash_del(local, bss);
 217         list_del(&bss->list);
 218         spin_unlock_bh(&local->bss_lock);
 219         ieee80211_rx_bss_free(bss);
 220 }
 221
 222 struct ieee80211_bss *
 223 ieee80211_bss_info_update(struct ieee80211_local *local,
 224                           struct ieee80211_rx_status *rx_status,
 225                           struct ieee80211_mgmt *mgmt,
 226                           size_t len,
 227                           struct ieee802_11_elems *elems,
 228                           int freq, bool beacon)
 229 {
 230         struct ieee80211_bss *bss;
 231         int clen;
 232
 233 #ifdef CONFIG_MAC80211_MESH
 234         if (elems->mesh_config)
 235                 bss = ieee80211_rx_mesh_bss_get(local, elems->mesh_id,
 236                                 elems->mesh_id_len, elems->mesh_config, freq);
 237         else
 238 #endif
 239                 bss = ieee80211_rx_bss_get(local, mgmt->bssid, freq,
 240                                            elems->ssid, elems->ssid_len);
 241         if (!bss) {
 242 #ifdef CONFIG_MAC80211_MESH
 243                 if (elems->mesh_config)
 244                         bss = ieee80211_rx_mesh_bss_add(local, elems->mesh_id,
 245                                 elems->mesh_id_len, elems->mesh_config,
 246                                 elems->mesh_config_len, freq);
 247                 else
 248 #endif
 249                         bss = ieee80211_rx_bss_add(local, mgmt->bssid, freq,
 250                                                   elems->ssid, elems->ssid_len);
 251                 if (!bss)
 252                         return NULL;
 253         } else {
 254 #if 0
 255                 /* TODO: order by RSSI? */
 256                 spin_lock_bh(&local->bss_lock);
 257                 list_move_tail(&bss->list, &local->bss_list);
 258                 spin_unlock_bh(&local->bss_lock);
 259 #endif
 260         }
 261
 262         /* save the ERP value so that it is available at association time */
 263         if (elems->erp_info && elems->erp_info_len >= 1) {
 264                 bss->erp_value = elems->erp_info[0];
 265                 bss->has_erp_value = 1;
 266         }
 267
 268         bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int);
 269         bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info);
 270
 271         if (elems->tim) {
 272                 struct ieee80211_tim_ie *tim_ie =
 273                         (struct ieee80211_tim_ie *)elems->tim;
 274                 bss->dtim_period = tim_ie->dtim_period;
 275         }
 276
 277         /* set default value for buggy APs */
 278         if (!elems->tim || bss->dtim_period == 0)
 279                 bss->dtim_period = 1;
 280
 281         bss->supp_rates_len = 0;
 282         if (elems->supp_rates) {
 283                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 284                 if (clen > elems->supp_rates_len)
 285                         clen = elems->supp_rates_len;
 286                 memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
 287                        clen);
 288                 bss->supp_rates_len += clen;
 289         }
 290         if (elems->ext_supp_rates) {
 291                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 292                 if (clen > elems->ext_supp_rates_len)
 293                         clen = elems->ext_supp_rates_len;
 294                 memcpy(&bss->supp_rates[bss->supp_rates_len],
 295                        elems->ext_supp_rates, clen);
 296                 bss->supp_rates_len += clen;
 297         }
 298
 299         bss->band = rx_status->band;
 300
 301         bss->timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
 302         bss->last_update = jiffies;
 303         bss->signal = rx_status->signal;
 304         bss->noise = rx_status->noise;
 305         bss->qual = rx_status->qual;
 306         bss->wmm_used = elems->wmm_param || elems->wmm_info;
 307
 308         if (!beacon)
 309                 bss->last_probe_resp = jiffies;
 310
 311         /*
 312          * For probe responses, or if we don't have any information yet,
 313          * use the IEs from the beacon.
 314          */
 315         if (!bss->ies || !beacon) {
 316                 if (bss->ies == NULL || bss->ies_len < elems->total_len) {
 317                         kfree(bss->ies);
 318                         bss->ies = kmalloc(elems->total_len, GFP_ATOMIC);
 319                 }
 320                 if (bss->ies) {
 321                         memcpy(bss->ies, elems->ie_start, elems->total_len);
 322                         bss->ies_len = elems->total_len;
 323                 } else
 324                         bss->ies_len = 0;
 325         }
 326
 327         return bss;
 328 }
 329
 330 ieee80211_rx_result
 331 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 332                   struct ieee80211_rx_status *rx_status)
 333 {
 334         struct ieee80211_mgmt *mgmt;
 335         struct ieee80211_bss *bss;
 336         u8 *elements;
 337         struct ieee80211_channel *channel;
 338         size_t baselen;
 339         int freq;
 340         __le16 fc;
 341         bool presp, beacon = false;
 342         struct ieee802_11_elems elems;
 343
 344         if (skb->len < 2)
 345                 return RX_DROP_UNUSABLE;
 346
 347         mgmt = (struct ieee80211_mgmt *) skb->data;
 348         fc = mgmt->frame_control;
 349
 350         if (ieee80211_is_ctl(fc))
 351                 return RX_CONTINUE;
 352
 353         if (skb->len < 24)
 354                 return RX_DROP_MONITOR;
 355
 356         presp = ieee80211_is_probe_resp(fc);
 357         if (presp) {
 358                 /* ignore ProbeResp to foreign address */
 359                 if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 360                         return RX_DROP_MONITOR;
 361
 362                 presp = true;
 363                 elements = mgmt->u.probe_resp.variable;
 364                 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
 365         } else {
 366                 beacon = ieee80211_is_beacon(fc);
 367                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 368                 elements = mgmt->u.beacon.variable;
 369         }
 370
 371         if (!presp && !beacon)
 372                 return RX_CONTINUE;
 373
 374         if (baselen > skb->len)
 375                 return RX_DROP_MONITOR;
 376
 377         ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
 378
 379         if (elems.ds_params && elems.ds_params_len == 1)
 380                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 381         else
 382                 freq = rx_status->freq;
 383
 384         channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
 385
 386         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 387                 return RX_DROP_MONITOR;
 388
 389         bss = ieee80211_bss_info_update(sdata->local, rx_status,
 390                                         mgmt, skb->len, &elems,
 391                                         freq, beacon);
 392         if (bss)
 393                 ieee80211_rx_bss_put(sdata->local, bss);
 394
 395         dev_kfree_skb(skb);
 396         return RX_QUEUED;
 397 }
 398
 399 void ieee80211_send_nullfunc(struct ieee80211_local *local,
 400                                     struct ieee80211_sub_if_data *sdata,
 401                                     int powersave)
 402 {
 403         struct sk_buff *skb;
 404         struct ieee80211_hdr *nullfunc;
 405         __le16 fc;
 406
 407         skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
 408         if (!skb) {
 409                 printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
 410                        "frame\n", sdata->dev->name);
 411                 return;
 412         }
 413         skb_reserve(skb, local->hw.extra_tx_headroom);
 414
 415         nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
 416         memset(nullfunc, 0, 24);
 417         fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
 418                          IEEE80211_FCTL_TODS);
 419         if (powersave)
 420                 fc |= cpu_to_le16(IEEE80211_FCTL_PM);
 421         nullfunc->frame_control = fc;
 422         memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
 423         memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
 424         memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);
 425
 426         ieee80211_tx_skb(sdata, skb, 0);
 427 }
 428
 429 void ieee80211_scan_completed(struct ieee80211_hw *hw)
 430 {
 431         struct ieee80211_local *local = hw_to_local(hw);
 432         struct ieee80211_sub_if_data *sdata;
 433         union iwreq_data wrqu;
 434
 435         if (WARN_ON(!local->hw_scanning && !local->sw_scanning))
 436                 return;
 437
 438         local->last_scan_completed = jiffies;
 439         memset(&wrqu, 0, sizeof(wrqu));
 440
 441         /*
 442          * local->scan_sdata could have been NULLed by the interface
 443          * down code in case we were scanning on an interface that is
 444          * being taken down.
 445          */
 446         sdata = local->scan_sdata;
 447         if (sdata)
 448                 wireless_send_event(sdata->dev, SIOCGIWSCAN, &wrqu, NULL);
 449
 450         if (local->hw_scanning) {
 451                 local->hw_scanning = false;
 452                 /*
 453                  * Somebody might have requested channel change during scan
 454                  * that we won't have acted upon, try now. ieee80211_hw_config
 455                  * will set the flag based on actual changes.
 456                  */
 457                 ieee80211_hw_config(local, 0);
 458                 goto done;
 459         }
 460
 461         local->sw_scanning = false;
 462         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 463
 464         netif_tx_lock_bh(local->mdev);
 465         netif_addr_lock(local->mdev);
 466         local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
 467         local->ops->configure_filter(local_to_hw(local),
 468                                      FIF_BCN_PRBRESP_PROMISC,
 469                                      &local->filter_flags,
 470                                      local->mdev->mc_count,
 471                                      local->mdev->mc_list);
 472
 473         netif_addr_unlock(local->mdev);
 474         netif_tx_unlock_bh(local->mdev);
 475
 476         mutex_lock(&local->iflist_mtx);
 477         list_for_each_entry(sdata, &local->interfaces, list) {
 478                 if (!netif_running(sdata->dev))
 479                         continue;
 480
 481                 /* Tell AP we're back */
 482                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 483                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 484                                 ieee80211_send_nullfunc(local, sdata, 0);
 485                                 netif_tx_wake_all_queues(sdata->dev);
 486                         }
 487                 } else
 488                         netif_tx_wake_all_queues(sdata->dev);
 489
 490                 ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 491         }
 492         mutex_unlock(&local->iflist_mtx);
 493
 494  done:
 495         ieee80211_mlme_notify_scan_completed(local);
 496         ieee80211_mesh_notify_scan_completed(local);
 497 }
 498 EXPORT_SYMBOL(ieee80211_scan_completed);
 499
 500 void ieee80211_scan_work(struct work_struct *work)
 501 {
 502         struct ieee80211_local *local =
 503                 container_of(work, struct ieee80211_local, scan_work.work);
 504         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 505         struct ieee80211_supported_band *sband;
 506         struct ieee80211_channel *chan;
 507         int skip;
 508         unsigned long next_delay = 0;
 509
 510         /*
 511          * Avoid re-scheduling when the sdata is going away.
 512          */
 513         if (!netif_running(sdata->dev))
 514                 return;
 515
 516         switch (local->scan_state) {
 517         case SCAN_SET_CHANNEL:
 518                 /*
 519                  * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
 520                  * after we successfully scanned the last channel of the last
 521                  * band (and the last band is supported by the hw)
 522                  */
 523                 if (local->scan_band < IEEE80211_NUM_BANDS)
 524                         sband = local->hw.wiphy->bands[local->scan_band];
 525                 else
 526                         sband = NULL;
 527
 528                 /*
 529                  * If we are at an unsupported band and have more bands
 530                  * left to scan, advance to the next supported one.
 531                  */
 532                 while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
 533                         local->scan_band++;
 534                         sband = local->hw.wiphy->bands[local->scan_band];
 535                         local->scan_channel_idx = 0;
 536                 }
 537
 538                 /* if no more bands/channels left, complete scan */
 539                 if (!sband || local->scan_channel_idx >= sband->n_channels) {
 540                         ieee80211_scan_completed(local_to_hw(local));
 541                         return;
 542                 }
 543                 skip = 0;
 544                 chan = &sband->channels[local->scan_channel_idx];
 545
 546                 if (chan->flags & IEEE80211_CHAN_DISABLED ||
 547                     (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 548                      chan->flags & IEEE80211_CHAN_NO_IBSS))
 549                         skip = 1;
 550
 551                 if (!skip) {
 552                         local->scan_channel = chan;
 553                         if (ieee80211_hw_config(local,
 554                                                 IEEE80211_CONF_CHANGE_CHANNEL))
 555                                 skip = 1;
 556                 }
 557
 558                 /* advance state machine to next channel/band */
 559                 local->scan_channel_idx++;
 560                 if (local->scan_channel_idx >= sband->n_channels) {
 561                         /*
 562                          * scan_band may end up == IEEE80211_NUM_BANDS, but
 563                          * we'll catch that case above and complete the scan
 564                          * if that is the case.
 565                          */
 566                         local->scan_band++;
 567                         local->scan_channel_idx = 0;
 568                 }
 569
 570                 if (skip)
 571                         break;
 572
 573                 next_delay = IEEE80211_PROBE_DELAY +
 574                              usecs_to_jiffies(local->hw.channel_change_time);
 575                 local->scan_state = SCAN_SEND_PROBE;
 576                 break;
 577         case SCAN_SEND_PROBE:
 578                 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 579                 local->scan_state = SCAN_SET_CHANNEL;
 580
 581                 if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 582                         break;
 583                 ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
 584                                          local->scan_ssid_len);
 585                 next_delay = IEEE80211_CHANNEL_TIME;
 586                 break;
 587         }
 588
 589         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 590                            next_delay);
 591 }
 592
 593
 594 int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 595                          u8 *ssid, size_t ssid_len)
 596 {
 597         struct ieee80211_local *local = scan_sdata->local;
 598         struct ieee80211_sub_if_data *sdata;
 599
 600         if (ssid_len > IEEE80211_MAX_SSID_LEN)
 601                 return -EINVAL;
 602
 603         /* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
 604          * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
 605          * BSSID: MACAddress
 606          * SSID
 607          * ScanType: ACTIVE, PASSIVE
 608          * ProbeDelay: delay (in microseconds) to be used prior to transmitting
 609          *    a Probe frame during active scanning
 610          * ChannelList
 611          * MinChannelTime (>= ProbeDelay), in TU
 612          * MaxChannelTime: (>= MinChannelTime), in TU
 613          */
 614
 615          /* MLME-SCAN.confirm
 616           * BSSDescriptionSet
 617           * ResultCode: SUCCESS, INVALID_PARAMETERS
 618          */
 619
 620         if (local->sw_scanning || local->hw_scanning) {
 621                 if (local->scan_sdata == scan_sdata)
 622                         return 0;
 623                 return -EBUSY;
 624         }
 625
 626         if (local->ops->hw_scan) {
 627                 int rc;
 628
 629                 local->hw_scanning = true;
 630                 rc = local->ops->hw_scan(local_to_hw(local), ssid, ssid_len);
 631                 if (rc) {
 632                         local->hw_scanning = false;
 633                         return rc;
 634                 }
 635                 local->scan_sdata = scan_sdata;
 636                 return 0;
 637         }
 638
 639         local->sw_scanning = true;
 640
 641         mutex_lock(&local->iflist_mtx);
 642         list_for_each_entry(sdata, &local->interfaces, list) {
 643                 if (!netif_running(sdata->dev))
 644                         continue;
 645
 646                 ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 647
 648                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 649                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 650                                 netif_tx_stop_all_queues(sdata->dev);
 651                                 ieee80211_send_nullfunc(local, sdata, 1);
 652                         }
 653                 } else
 654                         netif_tx_stop_all_queues(sdata->dev);
 655         }
 656         mutex_unlock(&local->iflist_mtx);
 657
 658         if (ssid) {
 659                 local->scan_ssid_len = ssid_len;
 660                 memcpy(local->scan_ssid, ssid, ssid_len);
 661         } else
 662                 local->scan_ssid_len = 0;
 663         local->scan_state = SCAN_SET_CHANNEL;
 664         local->scan_channel_idx = 0;
 665         local->scan_band = IEEE80211_BAND_2GHZ;
 666         local->scan_sdata = scan_sdata;
 667
 668         netif_addr_lock_bh(local->mdev);
 669         local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
 670         local->ops->configure_filter(local_to_hw(local),
 671                                      FIF_BCN_PRBRESP_PROMISC,
 672                                      &local->filter_flags,
 673                                      local->mdev->mc_count,
 674                                      local->mdev->mc_list);
 675         netif_addr_unlock_bh(local->mdev);
 676
 677         /* TODO: start scan as soon as all nullfunc frames are ACKed */
 678         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 679                            IEEE80211_CHANNEL_TIME);
 680
 681         return 0;
 682 }
 683
 684
 685 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 686                            u8 *ssid, size_t ssid_len)
 687 {
 688         struct ieee80211_local *local = sdata->local;
 689         struct ieee80211_if_sta *ifsta;
 690
 691         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 692                 return ieee80211_start_scan(sdata, ssid, ssid_len);
 693
 694         /*
 695          * STA has a state machine that might need to defer scanning
 696          * while it's trying to associate/authenticate, therefore we
 697          * queue it up to the state machine in that case.
 698          */
 699
 700         if (local->sw_scanning || local->hw_scanning) {
 701                 if (local->scan_sdata == sdata)
 702                         return 0;
 703                 return -EBUSY;
 704         }
 705
 706         ifsta = &sdata->u.sta;
 707
 708         ifsta->scan_ssid_len = ssid_len;
 709         if (ssid_len)
 710                 memcpy(ifsta->scan_ssid, ssid, ssid_len);
 711         set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
 712         queue_work(local->hw.workqueue, &ifsta->work);
 713
 714         return 0;
 715 }
 716
 717
 718 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 719                                    struct ieee80211_bss *bss,
 720                                    char **current_ev, char *end_buf)
 721 {
 722         u8 *pos, *end, *next;
 723         struct iw_event iwe;
 724
 725         if (bss == NULL || bss->ies == NULL)
 726                 return;
 727
 728         /*
 729          * If needed, fragment the IEs buffer (at IE boundaries) into short
 730          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 731          */
 732         pos = bss->ies;
 733         end = pos + bss->ies_len;
 734
 735         while (end - pos > IW_GENERIC_IE_MAX) {
 736                 next = pos + 2 + pos[1];
 737                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 738                         next = next + 2 + next[1];
 739
 740                 memset(&iwe, 0, sizeof(iwe));
 741                 iwe.cmd = IWEVGENIE;
 742                 iwe.u.data.length = next - pos;
 743                 *current_ev = iwe_stream_add_point(info, *current_ev,
 744                                                    end_buf, &iwe, pos);
 745
 746                 pos = next;
 747         }
 748
 749         if (end > pos) {
 750                 memset(&iwe, 0, sizeof(iwe));
 751                 iwe.cmd = IWEVGENIE;
 752                 iwe.u.data.length = end - pos;
 753                 *current_ev = iwe_stream_add_point(info, *current_ev,
 754                                                    end_buf, &iwe, pos);
 755         }
 756 }
 757
 758
 759 static char *
 760 ieee80211_scan_result(struct ieee80211_local *local,
 761                       struct iw_request_info *info,
 762                       struct ieee80211_bss *bss,
 763                       char *current_ev, char *end_buf)
 764 {
 765         struct iw_event iwe;
 766         char *buf;
 767
 768         if (time_after(jiffies,
 769                        bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
 770                 return current_ev;
 771
 772         memset(&iwe, 0, sizeof(iwe));
 773         iwe.cmd = SIOCGIWAP;
 774         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 775         memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
 776         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 777                                           IW_EV_ADDR_LEN);
 778
 779         memset(&iwe, 0, sizeof(iwe));
 780         iwe.cmd = SIOCGIWESSID;
 781         if (bss_mesh_cfg(bss)) {
 782                 iwe.u.data.length = bss_mesh_id_len(bss);
 783                 iwe.u.data.flags = 1;
 784                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 785                                                   &iwe, bss_mesh_id(bss));
 786         } else {
 787                 iwe.u.data.length = bss->ssid_len;
 788                 iwe.u.data.flags = 1;
 789                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 790                                                   &iwe, bss->ssid);
 791         }
 792
 793         if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 794             || bss_mesh_cfg(bss)) {
 795                 memset(&iwe, 0, sizeof(iwe));
 796                 iwe.cmd = SIOCGIWMODE;
 797                 if (bss_mesh_cfg(bss))
 798                         iwe.u.mode = IW_MODE_MESH;
 799                 else if (bss->capability & WLAN_CAPABILITY_ESS)
 800                         iwe.u.mode = IW_MODE_MASTER;
 801                 else
 802                         iwe.u.mode = IW_MODE_ADHOC;
 803                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 804                                                   &iwe, IW_EV_UINT_LEN);
 805         }
 806
 807         memset(&iwe, 0, sizeof(iwe));
 808         iwe.cmd = SIOCGIWFREQ;
 809         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
 810         iwe.u.freq.e = 0;
 811         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 812                                           IW_EV_FREQ_LEN);
 813
 814         memset(&iwe, 0, sizeof(iwe));
 815         iwe.cmd = SIOCGIWFREQ;
 816         iwe.u.freq.m = bss->freq;
 817         iwe.u.freq.e = 6;
 818         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 819                                           IW_EV_FREQ_LEN);
 820         memset(&iwe, 0, sizeof(iwe));
 821         iwe.cmd = IWEVQUAL;
 822         iwe.u.qual.qual = bss->qual;
 823         iwe.u.qual.level = bss->signal;
 824         iwe.u.qual.noise = bss->noise;
 825         iwe.u.qual.updated = local->wstats_flags;
 826         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 827                                           IW_EV_QUAL_LEN);
 828
 829         memset(&iwe, 0, sizeof(iwe));
 830         iwe.cmd = SIOCGIWENCODE;
 831         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 832                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 833         else
 834                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 835         iwe.u.data.length = 0;
 836         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 837                                           &iwe, "");
 838
 839         ieee80211_scan_add_ies(info, bss, &current_ev, end_buf);
 840
 841         if (bss->supp_rates_len > 0) {
 842                 /* display all supported rates in readable format */
 843                 char *p = current_ev + iwe_stream_lcp_len(info);
 844                 int i;
 845
 846                 memset(&iwe, 0, sizeof(iwe));
 847                 iwe.cmd = SIOCGIWRATE;
 848                 /* Those two flags are ignored... */
 849                 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 850
 851                 for (i = 0; i < bss->supp_rates_len; i++) {
 852                         iwe.u.bitrate.value = ((bss->supp_rates[i] &
 853                                                         0x7f) * 500000);
 854                         p = iwe_stream_add_value(info, current_ev, p,
 855                                         end_buf, &iwe, IW_EV_PARAM_LEN);
 856                 }
 857                 current_ev = p;
 858         }
 859
 860         buf = kmalloc(30, GFP_ATOMIC);
 861         if (buf) {
 862                 memset(&iwe, 0, sizeof(iwe));
 863                 iwe.cmd = IWEVCUSTOM;
 864                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
 865                 iwe.u.data.length = strlen(buf);
 866                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 867                                                   &iwe, buf);
 868                 memset(&iwe, 0, sizeof(iwe));
 869                 iwe.cmd = IWEVCUSTOM;
 870                 sprintf(buf, " Last beacon: %dms ago",
 871                         jiffies_to_msecs(jiffies - bss->last_update));
 872                 iwe.u.data.length = strlen(buf);
 873                 current_ev = iwe_stream_add_point(info, current_ev,
 874                                                   end_buf, &iwe, buf);
 875                 kfree(buf);
 876         }
 877
 878         if (bss_mesh_cfg(bss)) {
 879                 u8 *cfg = bss_mesh_cfg(bss);
 880                 buf = kmalloc(50, GFP_ATOMIC);
 881                 if (buf) {
 882                         memset(&iwe, 0, sizeof(iwe));
 883                         iwe.cmd = IWEVCUSTOM;
 884                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 885                         iwe.u.data.length = strlen(buf);
 886                         current_ev = iwe_stream_add_point(info, current_ev,
 887                                                           end_buf,
 888                                                           &iwe, buf);
 889                         sprintf(buf, "Path Selection Protocol ID: "
 890                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 891                                                         cfg[4]);
 892                         iwe.u.data.length = strlen(buf);
 893                         current_ev = iwe_stream_add_point(info, current_ev,
 894                                                           end_buf,
 895                                                           &iwe, buf);
 896                         sprintf(buf, "Path Selection Metric ID: "
 897                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 898                                                         cfg[8]);
 899                         iwe.u.data.length = strlen(buf);
 900                         current_ev = iwe_stream_add_point(info, current_ev,
 901                                                           end_buf,
 902                                                           &iwe, buf);
 903                         sprintf(buf, "Congestion Control Mode ID: "
 904                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 905                                                         cfg[11], cfg[12]);
 906                         iwe.u.data.length = strlen(buf);
 907                         current_ev = iwe_stream_add_point(info, current_ev,
 908                                                           end_buf,
 909                                                           &iwe, buf);
 910                         sprintf(buf, "Channel Precedence: "
 911                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 912                                                         cfg[15], cfg[16]);
 913                         iwe.u.data.length = strlen(buf);
 914                         current_ev = iwe_stream_add_point(info, current_ev,
 915                                                           end_buf,
 916                                                           &iwe, buf);
 917                         kfree(buf);
 918                 }
 919         }
 920
 921         return current_ev;
 922 }
 923
 924
 925 int ieee80211_scan_results(struct ieee80211_local *local,
 926                            struct iw_request_info *info,
 927                            char *buf, size_t len)
 928 {
 929         char *current_ev = buf;
 930         char *end_buf = buf + len;
 931         struct ieee80211_bss *bss;
 932
 933         spin_lock_bh(&local->bss_lock);
 934         list_for_each_entry(bss, &local->bss_list, list) {
 935                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 936                         spin_unlock_bh(&local->bss_lock);
 937                         return -E2BIG;
 938                 }
 939                 current_ev = ieee80211_scan_result(local, info, bss,
 940                                                        current_ev, end_buf);
 941         }
 942         spin_unlock_bh(&local->bss_lock);
 943         return current_ev - buf;
 944 }