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