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                 /*
 452                  * Somebody might have requested channel change during scan
 453                  * that we won't have acted upon, try now. ieee80211_hw_config
 454                  * will set the flag based on actual changes.
 455                  */
 456                 ieee80211_hw_config(local, 0);
 457                 goto done;
 458         }
 459
 460         local->sw_scanning = false;
 461         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 462
 463         netif_tx_lock_bh(local->mdev);
 464         netif_addr_lock(local->mdev);
 465         local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
 466         local->ops->configure_filter(local_to_hw(local),
 467                                      FIF_BCN_PRBRESP_PROMISC,
 468                                      &local->filter_flags,
 469                                      local->mdev->mc_count,
 470                                      local->mdev->mc_list);
 471
 472         netif_addr_unlock(local->mdev);
 473         netif_tx_unlock_bh(local->mdev);
 474
 475         rcu_read_lock();
 476         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 477                 /* Tell AP we're back */
 478                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 479                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 480                                 ieee80211_send_nullfunc(local, sdata, 0);
 481                                 netif_tx_wake_all_queues(sdata->dev);
 482                         }
 483                 } else
 484                         netif_tx_wake_all_queues(sdata->dev);
 485         }
 486         rcu_read_unlock();
 487
 488  done:
 489         ieee80211_mlme_notify_scan_completed(local);
 490         ieee80211_mesh_notify_scan_completed(local);
 491 }
 492 EXPORT_SYMBOL(ieee80211_scan_completed);
 493
 494
 495 void ieee80211_scan_work(struct work_struct *work)
 496 {
 497         struct ieee80211_local *local =
 498                 container_of(work, struct ieee80211_local, scan_work.work);
 499         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 500         struct ieee80211_supported_band *sband;
 501         struct ieee80211_channel *chan;
 502         int skip;
 503         unsigned long next_delay = 0;
 504
 505         /*
 506          * Avoid re-scheduling when the sdata is going away.
 507          */
 508         if (!netif_running(sdata->dev))
 509                 return;
 510
 511         switch (local->scan_state) {
 512         case SCAN_SET_CHANNEL:
 513                 /*
 514                  * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
 515                  * after we successfully scanned the last channel of the last
 516                  * band (and the last band is supported by the hw)
 517                  */
 518                 if (local->scan_band < IEEE80211_NUM_BANDS)
 519                         sband = local->hw.wiphy->bands[local->scan_band];
 520                 else
 521                         sband = NULL;
 522
 523                 /*
 524                  * If we are at an unsupported band and have more bands
 525                  * left to scan, advance to the next supported one.
 526                  */
 527                 while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
 528                         local->scan_band++;
 529                         sband = local->hw.wiphy->bands[local->scan_band];
 530                         local->scan_channel_idx = 0;
 531                 }
 532
 533                 /* if no more bands/channels left, complete scan */
 534                 if (!sband || local->scan_channel_idx >= sband->n_channels) {
 535                         ieee80211_scan_completed(local_to_hw(local));
 536                         return;
 537                 }
 538                 skip = 0;
 539                 chan = &sband->channels[local->scan_channel_idx];
 540
 541                 if (chan->flags & IEEE80211_CHAN_DISABLED ||
 542                     (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 543                      chan->flags & IEEE80211_CHAN_NO_IBSS))
 544                         skip = 1;
 545
 546                 if (!skip) {
 547                         local->scan_channel = chan;
 548                         if (ieee80211_hw_config(local,
 549                                                 IEEE80211_CONF_CHANGE_CHANNEL))
 550                                 skip = 1;
 551                 }
 552
 553                 /* advance state machine to next channel/band */
 554                 local->scan_channel_idx++;
 555                 if (local->scan_channel_idx >= sband->n_channels) {
 556                         /*
 557                          * scan_band may end up == IEEE80211_NUM_BANDS, but
 558                          * we'll catch that case above and complete the scan
 559                          * if that is the case.
 560                          */
 561                         local->scan_band++;
 562                         local->scan_channel_idx = 0;
 563                 }
 564
 565                 if (skip)
 566                         break;
 567
 568                 next_delay = IEEE80211_PROBE_DELAY +
 569                              usecs_to_jiffies(local->hw.channel_change_time);
 570                 local->scan_state = SCAN_SEND_PROBE;
 571                 break;
 572         case SCAN_SEND_PROBE:
 573                 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 574                 local->scan_state = SCAN_SET_CHANNEL;
 575
 576                 if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 577                         break;
 578                 ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
 579                                          local->scan_ssid_len);
 580                 next_delay = IEEE80211_CHANNEL_TIME;
 581                 break;
 582         }
 583
 584         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 585                            next_delay);
 586 }
 587
 588
 589 int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 590                          u8 *ssid, size_t ssid_len)
 591 {
 592         struct ieee80211_local *local = scan_sdata->local;
 593         struct ieee80211_sub_if_data *sdata;
 594
 595         if (ssid_len > IEEE80211_MAX_SSID_LEN)
 596                 return -EINVAL;
 597
 598         /* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
 599          * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
 600          * BSSID: MACAddress
 601          * SSID
 602          * ScanType: ACTIVE, PASSIVE
 603          * ProbeDelay: delay (in microseconds) to be used prior to transmitting
 604          *    a Probe frame during active scanning
 605          * ChannelList
 606          * MinChannelTime (>= ProbeDelay), in TU
 607          * MaxChannelTime: (>= MinChannelTime), in TU
 608          */
 609
 610          /* MLME-SCAN.confirm
 611           * BSSDescriptionSet
 612           * ResultCode: SUCCESS, INVALID_PARAMETERS
 613          */
 614
 615         if (local->sw_scanning || local->hw_scanning) {
 616                 if (local->scan_sdata == scan_sdata)
 617                         return 0;
 618                 return -EBUSY;
 619         }
 620
 621         if (local->ops->hw_scan) {
 622                 int rc;
 623
 624                 local->hw_scanning = true;
 625                 rc = local->ops->hw_scan(local_to_hw(local), ssid, ssid_len);
 626                 if (rc) {
 627                         local->hw_scanning = false;
 628                         return rc;
 629                 }
 630                 local->scan_sdata = scan_sdata;
 631                 return 0;
 632         }
 633
 634         local->sw_scanning = true;
 635
 636         rcu_read_lock();
 637         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 638                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 639                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 640                                 netif_tx_stop_all_queues(sdata->dev);
 641                                 ieee80211_send_nullfunc(local, sdata, 1);
 642                         }
 643                 } else
 644                         netif_tx_stop_all_queues(sdata->dev);
 645         }
 646         rcu_read_unlock();
 647
 648         if (ssid) {
 649                 local->scan_ssid_len = ssid_len;
 650                 memcpy(local->scan_ssid, ssid, ssid_len);
 651         } else
 652                 local->scan_ssid_len = 0;
 653         local->scan_state = SCAN_SET_CHANNEL;
 654         local->scan_channel_idx = 0;
 655         local->scan_band = IEEE80211_BAND_2GHZ;
 656         local->scan_sdata = scan_sdata;
 657
 658         netif_addr_lock_bh(local->mdev);
 659         local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
 660         local->ops->configure_filter(local_to_hw(local),
 661                                      FIF_BCN_PRBRESP_PROMISC,
 662                                      &local->filter_flags,
 663                                      local->mdev->mc_count,
 664                                      local->mdev->mc_list);
 665         netif_addr_unlock_bh(local->mdev);
 666
 667         /* TODO: start scan as soon as all nullfunc frames are ACKed */
 668         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 669                            IEEE80211_CHANNEL_TIME);
 670
 671         return 0;
 672 }
 673
 674
 675 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 676                            u8 *ssid, size_t ssid_len)
 677 {
 678         struct ieee80211_local *local = sdata->local;
 679         struct ieee80211_if_sta *ifsta;
 680
 681         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 682                 return ieee80211_start_scan(sdata, ssid, ssid_len);
 683
 684         /*
 685          * STA has a state machine that might need to defer scanning
 686          * while it's trying to associate/authenticate, therefore we
 687          * queue it up to the state machine in that case.
 688          */
 689
 690         if (local->sw_scanning || local->hw_scanning) {
 691                 if (local->scan_sdata == sdata)
 692                         return 0;
 693                 return -EBUSY;
 694         }
 695
 696         ifsta = &sdata->u.sta;
 697
 698         ifsta->scan_ssid_len = ssid_len;
 699         if (ssid_len)
 700                 memcpy(ifsta->scan_ssid, ssid, ssid_len);
 701         set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
 702         queue_work(local->hw.workqueue, &ifsta->work);
 703
 704         return 0;
 705 }
 706
 707
 708 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 709                                    struct ieee80211_bss *bss,
 710                                    char **current_ev, char *end_buf)
 711 {
 712         u8 *pos, *end, *next;
 713         struct iw_event iwe;
 714
 715         if (bss == NULL || bss->ies == NULL)
 716                 return;
 717
 718         /*
 719          * If needed, fragment the IEs buffer (at IE boundaries) into short
 720          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 721          */
 722         pos = bss->ies;
 723         end = pos + bss->ies_len;
 724
 725         while (end - pos > IW_GENERIC_IE_MAX) {
 726                 next = pos + 2 + pos[1];
 727                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 728                         next = next + 2 + next[1];
 729
 730                 memset(&iwe, 0, sizeof(iwe));
 731                 iwe.cmd = IWEVGENIE;
 732                 iwe.u.data.length = next - pos;
 733                 *current_ev = iwe_stream_add_point(info, *current_ev,
 734                                                    end_buf, &iwe, pos);
 735
 736                 pos = next;
 737         }
 738
 739         if (end > pos) {
 740                 memset(&iwe, 0, sizeof(iwe));
 741                 iwe.cmd = IWEVGENIE;
 742                 iwe.u.data.length = end - pos;
 743                 *current_ev = iwe_stream_add_point(info, *current_ev,
 744                                                    end_buf, &iwe, pos);
 745         }
 746 }
 747
 748
 749 static char *
 750 ieee80211_scan_result(struct ieee80211_local *local,
 751                       struct iw_request_info *info,
 752                       struct ieee80211_bss *bss,
 753                       char *current_ev, char *end_buf)
 754 {
 755         struct iw_event iwe;
 756         char *buf;
 757
 758         if (time_after(jiffies,
 759                        bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
 760                 return current_ev;
 761
 762         memset(&iwe, 0, sizeof(iwe));
 763         iwe.cmd = SIOCGIWAP;
 764         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 765         memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
 766         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 767                                           IW_EV_ADDR_LEN);
 768
 769         memset(&iwe, 0, sizeof(iwe));
 770         iwe.cmd = SIOCGIWESSID;
 771         if (bss_mesh_cfg(bss)) {
 772                 iwe.u.data.length = bss_mesh_id_len(bss);
 773                 iwe.u.data.flags = 1;
 774                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 775                                                   &iwe, bss_mesh_id(bss));
 776         } else {
 777                 iwe.u.data.length = bss->ssid_len;
 778                 iwe.u.data.flags = 1;
 779                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 780                                                   &iwe, bss->ssid);
 781         }
 782
 783         if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 784             || bss_mesh_cfg(bss)) {
 785                 memset(&iwe, 0, sizeof(iwe));
 786                 iwe.cmd = SIOCGIWMODE;
 787                 if (bss_mesh_cfg(bss))
 788                         iwe.u.mode = IW_MODE_MESH;
 789                 else if (bss->capability & WLAN_CAPABILITY_ESS)
 790                         iwe.u.mode = IW_MODE_MASTER;
 791                 else
 792                         iwe.u.mode = IW_MODE_ADHOC;
 793                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 794                                                   &iwe, IW_EV_UINT_LEN);
 795         }
 796
 797         memset(&iwe, 0, sizeof(iwe));
 798         iwe.cmd = SIOCGIWFREQ;
 799         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
 800         iwe.u.freq.e = 0;
 801         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 802                                           IW_EV_FREQ_LEN);
 803
 804         memset(&iwe, 0, sizeof(iwe));
 805         iwe.cmd = SIOCGIWFREQ;
 806         iwe.u.freq.m = bss->freq;
 807         iwe.u.freq.e = 6;
 808         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 809                                           IW_EV_FREQ_LEN);
 810         memset(&iwe, 0, sizeof(iwe));
 811         iwe.cmd = IWEVQUAL;
 812         iwe.u.qual.qual = bss->qual;
 813         iwe.u.qual.level = bss->signal;
 814         iwe.u.qual.noise = bss->noise;
 815         iwe.u.qual.updated = local->wstats_flags;
 816         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 817                                           IW_EV_QUAL_LEN);
 818
 819         memset(&iwe, 0, sizeof(iwe));
 820         iwe.cmd = SIOCGIWENCODE;
 821         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 822                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 823         else
 824                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 825         iwe.u.data.length = 0;
 826         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 827                                           &iwe, "");
 828
 829         ieee80211_scan_add_ies(info, bss, &current_ev, end_buf);
 830
 831         if (bss->supp_rates_len > 0) {
 832                 /* display all supported rates in readable format */
 833                 char *p = current_ev + iwe_stream_lcp_len(info);
 834                 int i;
 835
 836                 memset(&iwe, 0, sizeof(iwe));
 837                 iwe.cmd = SIOCGIWRATE;
 838                 /* Those two flags are ignored... */
 839                 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 840
 841                 for (i = 0; i < bss->supp_rates_len; i++) {
 842                         iwe.u.bitrate.value = ((bss->supp_rates[i] &
 843                                                         0x7f) * 500000);
 844                         p = iwe_stream_add_value(info, current_ev, p,
 845                                         end_buf, &iwe, IW_EV_PARAM_LEN);
 846                 }
 847                 current_ev = p;
 848         }
 849
 850         buf = kmalloc(30, GFP_ATOMIC);
 851         if (buf) {
 852                 memset(&iwe, 0, sizeof(iwe));
 853                 iwe.cmd = IWEVCUSTOM;
 854                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
 855                 iwe.u.data.length = strlen(buf);
 856                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 857                                                   &iwe, buf);
 858                 memset(&iwe, 0, sizeof(iwe));
 859                 iwe.cmd = IWEVCUSTOM;
 860                 sprintf(buf, " Last beacon: %dms ago",
 861                         jiffies_to_msecs(jiffies - bss->last_update));
 862                 iwe.u.data.length = strlen(buf);
 863                 current_ev = iwe_stream_add_point(info, current_ev,
 864                                                   end_buf, &iwe, buf);
 865                 kfree(buf);
 866         }
 867
 868         if (bss_mesh_cfg(bss)) {
 869                 u8 *cfg = bss_mesh_cfg(bss);
 870                 buf = kmalloc(50, GFP_ATOMIC);
 871                 if (buf) {
 872                         memset(&iwe, 0, sizeof(iwe));
 873                         iwe.cmd = IWEVCUSTOM;
 874                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 875                         iwe.u.data.length = strlen(buf);
 876                         current_ev = iwe_stream_add_point(info, current_ev,
 877                                                           end_buf,
 878                                                           &iwe, buf);
 879                         sprintf(buf, "Path Selection Protocol ID: "
 880                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 881                                                         cfg[4]);
 882                         iwe.u.data.length = strlen(buf);
 883                         current_ev = iwe_stream_add_point(info, current_ev,
 884                                                           end_buf,
 885                                                           &iwe, buf);
 886                         sprintf(buf, "Path Selection Metric ID: "
 887                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 888                                                         cfg[8]);
 889                         iwe.u.data.length = strlen(buf);
 890                         current_ev = iwe_stream_add_point(info, current_ev,
 891                                                           end_buf,
 892                                                           &iwe, buf);
 893                         sprintf(buf, "Congestion Control Mode ID: "
 894                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 895                                                         cfg[11], cfg[12]);
 896                         iwe.u.data.length = strlen(buf);
 897                         current_ev = iwe_stream_add_point(info, current_ev,
 898                                                           end_buf,
 899                                                           &iwe, buf);
 900                         sprintf(buf, "Channel Precedence: "
 901                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 902                                                         cfg[15], cfg[16]);
 903                         iwe.u.data.length = strlen(buf);
 904                         current_ev = iwe_stream_add_point(info, current_ev,
 905                                                           end_buf,
 906                                                           &iwe, buf);
 907                         kfree(buf);
 908                 }
 909         }
 910
 911         return current_ev;
 912 }
 913
 914
 915 int ieee80211_scan_results(struct ieee80211_local *local,
 916                            struct iw_request_info *info,
 917                            char *buf, size_t len)
 918 {
 919         char *current_ev = buf;
 920         char *end_buf = buf + len;
 921         struct ieee80211_bss *bss;
 922
 923         spin_lock_bh(&local->bss_lock);
 924         list_for_each_entry(bss, &local->bss_list, list) {
 925                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 926                         spin_unlock_bh(&local->bss_lock);
 927                         return -E2BIG;
 928                 }
 929                 current_ev = ieee80211_scan_result(local, info, bss,
 930                                                        current_ev, end_buf);
 931         }
 932         spin_unlock_bh(&local->bss_lock);
 933         return current_ev - buf;
 934 }