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                 if (ieee80211_hw_config(local))
 452                         printk(KERN_DEBUG "%s: failed to restore operational "
 453                                "channel after scan\n", wiphy_name(local->hw.wiphy));
 454
 455                 goto done;
 456         }
 457
 458         local->sw_scanning = false;
 459         if (ieee80211_hw_config(local))
 460                 printk(KERN_DEBUG "%s: failed to restore operational "
 461                        "channel after scan\n", wiphy_name(local->hw.wiphy));
 462
 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         rcu_read_lock();
 477         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 478                 /* Tell AP we're back */
 479                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 480                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 481                                 ieee80211_send_nullfunc(local, sdata, 0);
 482                                 netif_tx_wake_all_queues(sdata->dev);
 483                         }
 484                 } else
 485                         netif_tx_wake_all_queues(sdata->dev);
 486         }
 487         rcu_read_unlock();
 488
 489  done:
 490         ieee80211_mlme_notify_scan_completed(local);
 491         ieee80211_mesh_notify_scan_completed(local);
 492 }
 493 EXPORT_SYMBOL(ieee80211_scan_completed);
 494
 495
 496 void ieee80211_scan_work(struct work_struct *work)
 497 {
 498         struct ieee80211_local *local =
 499                 container_of(work, struct ieee80211_local, scan_work.work);
 500         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 501         struct ieee80211_supported_band *sband;
 502         struct ieee80211_channel *chan;
 503         int skip;
 504         unsigned long next_delay = 0;
 505
 506         /*
 507          * Avoid re-scheduling when the sdata is going away.
 508          */
 509         if (!netif_running(sdata->dev))
 510                 return;
 511
 512         switch (local->scan_state) {
 513         case SCAN_SET_CHANNEL:
 514                 /*
 515                  * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
 516                  * after we successfully scanned the last channel of the last
 517                  * band (and the last band is supported by the hw)
 518                  */
 519                 if (local->scan_band < IEEE80211_NUM_BANDS)
 520                         sband = local->hw.wiphy->bands[local->scan_band];
 521                 else
 522                         sband = NULL;
 523
 524                 /*
 525                  * If we are at an unsupported band and have more bands
 526                  * left to scan, advance to the next supported one.
 527                  */
 528                 while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
 529                         local->scan_band++;
 530                         sband = local->hw.wiphy->bands[local->scan_band];
 531                         local->scan_channel_idx = 0;
 532                 }
 533
 534                 /* if no more bands/channels left, complete scan */
 535                 if (!sband || local->scan_channel_idx >= sband->n_channels) {
 536                         ieee80211_scan_completed(local_to_hw(local));
 537                         return;
 538                 }
 539                 skip = 0;
 540                 chan = &sband->channels[local->scan_channel_idx];
 541
 542                 if (chan->flags & IEEE80211_CHAN_DISABLED ||
 543                     (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 544                      chan->flags & IEEE80211_CHAN_NO_IBSS))
 545                         skip = 1;
 546
 547                 if (!skip) {
 548                         local->scan_channel = chan;
 549                         if (ieee80211_hw_config(local)) {
 550                                 printk(KERN_DEBUG "%s: failed to set freq to "
 551                                        "%d MHz for scan\n", wiphy_name(local->hw.wiphy),
 552                                        chan->center_freq);
 553                                 skip = 1;
 554                         }
 555                 }
 556
 557                 /* advance state machine to next channel/band */
 558                 local->scan_channel_idx++;
 559                 if (local->scan_channel_idx >= sband->n_channels) {
 560                         /*
 561                          * scan_band may end up == IEEE80211_NUM_BANDS, but
 562                          * we'll catch that case above and complete the scan
 563                          * if that is the case.
 564                          */
 565                         local->scan_band++;
 566                         local->scan_channel_idx = 0;
 567                 }
 568
 569                 if (skip)
 570                         break;
 571
 572                 next_delay = IEEE80211_PROBE_DELAY +
 573                              usecs_to_jiffies(local->hw.channel_change_time);
 574                 local->scan_state = SCAN_SEND_PROBE;
 575                 break;
 576         case SCAN_SEND_PROBE:
 577                 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 578                 local->scan_state = SCAN_SET_CHANNEL;
 579
 580                 if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 581                         break;
 582                 ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
 583                                          local->scan_ssid_len);
 584                 next_delay = IEEE80211_CHANNEL_TIME;
 585                 break;
 586         }
 587
 588         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 589                            next_delay);
 590 }
 591
 592
 593 int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 594                          u8 *ssid, size_t ssid_len)
 595 {
 596         struct ieee80211_local *local = scan_sdata->local;
 597         struct ieee80211_sub_if_data *sdata;
 598
 599         if (ssid_len > IEEE80211_MAX_SSID_LEN)
 600                 return -EINVAL;
 601
 602         /* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
 603          * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
 604          * BSSID: MACAddress
 605          * SSID
 606          * ScanType: ACTIVE, PASSIVE
 607          * ProbeDelay: delay (in microseconds) to be used prior to transmitting
 608          *    a Probe frame during active scanning
 609          * ChannelList
 610          * MinChannelTime (>= ProbeDelay), in TU
 611          * MaxChannelTime: (>= MinChannelTime), in TU
 612          */
 613
 614          /* MLME-SCAN.confirm
 615           * BSSDescriptionSet
 616           * ResultCode: SUCCESS, INVALID_PARAMETERS
 617          */
 618
 619         if (local->sw_scanning || local->hw_scanning) {
 620                 if (local->scan_sdata == scan_sdata)
 621                         return 0;
 622                 return -EBUSY;
 623         }
 624
 625         if (local->ops->hw_scan) {
 626                 int rc;
 627
 628                 local->hw_scanning = true;
 629                 rc = local->ops->hw_scan(local_to_hw(local), ssid, ssid_len);
 630                 if (rc) {
 631                         local->hw_scanning = false;
 632                         return rc;
 633                 }
 634                 local->scan_sdata = scan_sdata;
 635                 return 0;
 636         }
 637
 638         local->sw_scanning = true;
 639
 640         rcu_read_lock();
 641         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 642                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 643                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 644                                 netif_tx_stop_all_queues(sdata->dev);
 645                                 ieee80211_send_nullfunc(local, sdata, 1);
 646                         }
 647                 } else
 648                         netif_tx_stop_all_queues(sdata->dev);
 649         }
 650         rcu_read_unlock();
 651
 652         if (ssid) {
 653                 local->scan_ssid_len = ssid_len;
 654                 memcpy(local->scan_ssid, ssid, ssid_len);
 655         } else
 656                 local->scan_ssid_len = 0;
 657         local->scan_state = SCAN_SET_CHANNEL;
 658         local->scan_channel_idx = 0;
 659         local->scan_band = IEEE80211_BAND_2GHZ;
 660         local->scan_sdata = scan_sdata;
 661
 662         netif_addr_lock_bh(local->mdev);
 663         local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
 664         local->ops->configure_filter(local_to_hw(local),
 665                                      FIF_BCN_PRBRESP_PROMISC,
 666                                      &local->filter_flags,
 667                                      local->mdev->mc_count,
 668                                      local->mdev->mc_list);
 669         netif_addr_unlock_bh(local->mdev);
 670
 671         /* TODO: start scan as soon as all nullfunc frames are ACKed */
 672         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 673                            IEEE80211_CHANNEL_TIME);
 674
 675         return 0;
 676 }
 677
 678
 679 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 680                            u8 *ssid, size_t ssid_len)
 681 {
 682         struct ieee80211_local *local = sdata->local;
 683         struct ieee80211_if_sta *ifsta;
 684
 685         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 686                 return ieee80211_start_scan(sdata, ssid, ssid_len);
 687
 688         /*
 689          * STA has a state machine that might need to defer scanning
 690          * while it's trying to associate/authenticate, therefore we
 691          * queue it up to the state machine in that case.
 692          */
 693
 694         if (local->sw_scanning || local->hw_scanning) {
 695                 if (local->scan_sdata == sdata)
 696                         return 0;
 697                 return -EBUSY;
 698         }
 699
 700         ifsta = &sdata->u.sta;
 701
 702         ifsta->scan_ssid_len = ssid_len;
 703         if (ssid_len)
 704                 memcpy(ifsta->scan_ssid, ssid, ssid_len);
 705         set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
 706         queue_work(local->hw.workqueue, &ifsta->work);
 707
 708         return 0;
 709 }
 710
 711
 712 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 713                                    struct ieee80211_bss *bss,
 714                                    char **current_ev, char *end_buf)
 715 {
 716         u8 *pos, *end, *next;
 717         struct iw_event iwe;
 718
 719         if (bss == NULL || bss->ies == NULL)
 720                 return;
 721
 722         /*
 723          * If needed, fragment the IEs buffer (at IE boundaries) into short
 724          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 725          */
 726         pos = bss->ies;
 727         end = pos + bss->ies_len;
 728
 729         while (end - pos > IW_GENERIC_IE_MAX) {
 730                 next = pos + 2 + pos[1];
 731                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 732                         next = next + 2 + next[1];
 733
 734                 memset(&iwe, 0, sizeof(iwe));
 735                 iwe.cmd = IWEVGENIE;
 736                 iwe.u.data.length = next - pos;
 737                 *current_ev = iwe_stream_add_point(info, *current_ev,
 738                                                    end_buf, &iwe, pos);
 739
 740                 pos = next;
 741         }
 742
 743         if (end > pos) {
 744                 memset(&iwe, 0, sizeof(iwe));
 745                 iwe.cmd = IWEVGENIE;
 746                 iwe.u.data.length = end - pos;
 747                 *current_ev = iwe_stream_add_point(info, *current_ev,
 748                                                    end_buf, &iwe, pos);
 749         }
 750 }
 751
 752
 753 static char *
 754 ieee80211_scan_result(struct ieee80211_local *local,
 755                       struct iw_request_info *info,
 756                       struct ieee80211_bss *bss,
 757                       char *current_ev, char *end_buf)
 758 {
 759         struct iw_event iwe;
 760         char *buf;
 761
 762         if (time_after(jiffies,
 763                        bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
 764                 return current_ev;
 765
 766         memset(&iwe, 0, sizeof(iwe));
 767         iwe.cmd = SIOCGIWAP;
 768         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 769         memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
 770         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 771                                           IW_EV_ADDR_LEN);
 772
 773         memset(&iwe, 0, sizeof(iwe));
 774         iwe.cmd = SIOCGIWESSID;
 775         if (bss_mesh_cfg(bss)) {
 776                 iwe.u.data.length = bss_mesh_id_len(bss);
 777                 iwe.u.data.flags = 1;
 778                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 779                                                   &iwe, bss_mesh_id(bss));
 780         } else {
 781                 iwe.u.data.length = bss->ssid_len;
 782                 iwe.u.data.flags = 1;
 783                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 784                                                   &iwe, bss->ssid);
 785         }
 786
 787         if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 788             || bss_mesh_cfg(bss)) {
 789                 memset(&iwe, 0, sizeof(iwe));
 790                 iwe.cmd = SIOCGIWMODE;
 791                 if (bss_mesh_cfg(bss))
 792                         iwe.u.mode = IW_MODE_MESH;
 793                 else if (bss->capability & WLAN_CAPABILITY_ESS)
 794                         iwe.u.mode = IW_MODE_MASTER;
 795                 else
 796                         iwe.u.mode = IW_MODE_ADHOC;
 797                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 798                                                   &iwe, IW_EV_UINT_LEN);
 799         }
 800
 801         memset(&iwe, 0, sizeof(iwe));
 802         iwe.cmd = SIOCGIWFREQ;
 803         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
 804         iwe.u.freq.e = 0;
 805         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 806                                           IW_EV_FREQ_LEN);
 807
 808         memset(&iwe, 0, sizeof(iwe));
 809         iwe.cmd = SIOCGIWFREQ;
 810         iwe.u.freq.m = bss->freq;
 811         iwe.u.freq.e = 6;
 812         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 813                                           IW_EV_FREQ_LEN);
 814         memset(&iwe, 0, sizeof(iwe));
 815         iwe.cmd = IWEVQUAL;
 816         iwe.u.qual.qual = bss->qual;
 817         iwe.u.qual.level = bss->signal;
 818         iwe.u.qual.noise = bss->noise;
 819         iwe.u.qual.updated = local->wstats_flags;
 820         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 821                                           IW_EV_QUAL_LEN);
 822
 823         memset(&iwe, 0, sizeof(iwe));
 824         iwe.cmd = SIOCGIWENCODE;
 825         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 826                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 827         else
 828                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 829         iwe.u.data.length = 0;
 830         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 831                                           &iwe, "");
 832
 833         ieee80211_scan_add_ies(info, bss, &current_ev, end_buf);
 834
 835         if (bss->supp_rates_len > 0) {
 836                 /* display all supported rates in readable format */
 837                 char *p = current_ev + iwe_stream_lcp_len(info);
 838                 int i;
 839
 840                 memset(&iwe, 0, sizeof(iwe));
 841                 iwe.cmd = SIOCGIWRATE;
 842                 /* Those two flags are ignored... */
 843                 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 844
 845                 for (i = 0; i < bss->supp_rates_len; i++) {
 846                         iwe.u.bitrate.value = ((bss->supp_rates[i] &
 847                                                         0x7f) * 500000);
 848                         p = iwe_stream_add_value(info, current_ev, p,
 849                                         end_buf, &iwe, IW_EV_PARAM_LEN);
 850                 }
 851                 current_ev = p;
 852         }
 853
 854         buf = kmalloc(30, GFP_ATOMIC);
 855         if (buf) {
 856                 memset(&iwe, 0, sizeof(iwe));
 857                 iwe.cmd = IWEVCUSTOM;
 858                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
 859                 iwe.u.data.length = strlen(buf);
 860                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 861                                                   &iwe, buf);
 862                 memset(&iwe, 0, sizeof(iwe));
 863                 iwe.cmd = IWEVCUSTOM;
 864                 sprintf(buf, " Last beacon: %dms ago",
 865                         jiffies_to_msecs(jiffies - bss->last_update));
 866                 iwe.u.data.length = strlen(buf);
 867                 current_ev = iwe_stream_add_point(info, current_ev,
 868                                                   end_buf, &iwe, buf);
 869                 kfree(buf);
 870         }
 871
 872         if (bss_mesh_cfg(bss)) {
 873                 u8 *cfg = bss_mesh_cfg(bss);
 874                 buf = kmalloc(50, GFP_ATOMIC);
 875                 if (buf) {
 876                         memset(&iwe, 0, sizeof(iwe));
 877                         iwe.cmd = IWEVCUSTOM;
 878                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 879                         iwe.u.data.length = strlen(buf);
 880                         current_ev = iwe_stream_add_point(info, current_ev,
 881                                                           end_buf,
 882                                                           &iwe, buf);
 883                         sprintf(buf, "Path Selection Protocol ID: "
 884                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 885                                                         cfg[4]);
 886                         iwe.u.data.length = strlen(buf);
 887                         current_ev = iwe_stream_add_point(info, current_ev,
 888                                                           end_buf,
 889                                                           &iwe, buf);
 890                         sprintf(buf, "Path Selection Metric ID: "
 891                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 892                                                         cfg[8]);
 893                         iwe.u.data.length = strlen(buf);
 894                         current_ev = iwe_stream_add_point(info, current_ev,
 895                                                           end_buf,
 896                                                           &iwe, buf);
 897                         sprintf(buf, "Congestion Control Mode ID: "
 898                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 899                                                         cfg[11], cfg[12]);
 900                         iwe.u.data.length = strlen(buf);
 901                         current_ev = iwe_stream_add_point(info, current_ev,
 902                                                           end_buf,
 903                                                           &iwe, buf);
 904                         sprintf(buf, "Channel Precedence: "
 905                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 906                                                         cfg[15], cfg[16]);
 907                         iwe.u.data.length = strlen(buf);
 908                         current_ev = iwe_stream_add_point(info, current_ev,
 909                                                           end_buf,
 910                                                           &iwe, buf);
 911                         kfree(buf);
 912                 }
 913         }
 914
 915         return current_ev;
 916 }
 917
 918
 919 int ieee80211_scan_results(struct ieee80211_local *local,
 920                            struct iw_request_info *info,
 921                            char *buf, size_t len)
 922 {
 923         char *current_ev = buf;
 924         char *end_buf = buf + len;
 925         struct ieee80211_bss *bss;
 926
 927         spin_lock_bh(&local->bss_lock);
 928         list_for_each_entry(bss, &local->bss_list, list) {
 929                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 930                         spin_unlock_bh(&local->bss_lock);
 931                         return -E2BIG;
 932                 }
 933                 current_ev = ieee80211_scan_result(local, info, bss,
 934                                                        current_ev, end_buf);
 935         }
 936         spin_unlock_bh(&local->bss_lock);
 937         return current_ev - buf;
 938 }