net/mac80211/scan.c

   1 /*
   2  * Scanning implementation
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2004, Instant802 Networks, Inc.
   6  * Copyright 2005, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 /* TODO:
  16  * order BSS list by RSSI(?) ("quality of AP")
  17  * scan result table filtering (by capability (privacy, IBSS/BSS, WPA/RSN IE,
  18  *    SSID)
  19  */
  20
  21 #include <linux/wireless.h>
  22 #include <linux/if_arp.h>
  23 #include <linux/rtnetlink.h>
  24 #include <net/mac80211.h>
  25 #include <net/iw_handler.h>
  26
  27 #include "ieee80211_i.h"
  28 #include "mesh.h"
  29
  30 #define IEEE80211_PROBE_DELAY (HZ / 33)
  31 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  32 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
  33
  34 void ieee80211_rx_bss_list_init(struct ieee80211_local *local)
  35 {
  36         spin_lock_init(&local->bss_lock);
  37         INIT_LIST_HEAD(&local->bss_list);
  38 }
  39
  40 void ieee80211_rx_bss_list_deinit(struct ieee80211_local *local)
  41 {
  42         struct ieee80211_bss *bss, *tmp;
  43
  44         list_for_each_entry_safe(bss, tmp, &local->bss_list, list)
  45                 ieee80211_rx_bss_put(local, bss);
  46 }
  47
  48 struct ieee80211_bss *
  49 ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
  50                      u8 *ssid, u8 ssid_len)
  51 {
  52         struct ieee80211_bss *bss;
  53
  54         spin_lock_bh(&local->bss_lock);
  55         bss = local->bss_hash[STA_HASH(bssid)];
  56         while (bss) {
  57                 if (!bss_mesh_cfg(bss) &&
  58                     !memcmp(bss->bssid, bssid, ETH_ALEN) &&
  59                     bss->freq == freq &&
  60                     bss->ssid_len == ssid_len &&
  61                     (ssid_len == 0 || !memcmp(bss->ssid, ssid, ssid_len))) {
  62                         atomic_inc(&bss->users);
  63                         break;
  64                 }
  65                 bss = bss->hnext;
  66         }
  67         spin_unlock_bh(&local->bss_lock);
  68         return bss;
  69 }
  70
  71 /* Caller must hold local->bss_lock */
  72 static void __ieee80211_rx_bss_hash_add(struct ieee80211_local *local,
  73                                         struct ieee80211_bss *bss)
  74 {
  75         u8 hash_idx;
  76
  77         if (bss_mesh_cfg(bss))
  78                 hash_idx = mesh_id_hash(bss_mesh_id(bss),
  79                                         bss_mesh_id_len(bss));
  80         else
  81                 hash_idx = STA_HASH(bss->bssid);
  82
  83         bss->hnext = local->bss_hash[hash_idx];
  84         local->bss_hash[hash_idx] = bss;
  85 }
  86
  87 /* Caller must hold local->bss_lock */
  88 static void __ieee80211_rx_bss_hash_del(struct ieee80211_local *local,
  89                                         struct ieee80211_bss *bss)
  90 {
  91         struct ieee80211_bss *b, *prev = NULL;
  92         b = local->bss_hash[STA_HASH(bss->bssid)];
  93         while (b) {
  94                 if (b == bss) {
  95                         if (!prev)
  96                                 local->bss_hash[STA_HASH(bss->bssid)] =
  97                                         bss->hnext;
  98                         else
  99                                 prev->hnext = bss->hnext;
 100                         break;
 101                 }
 102                 prev = b;
 103                 b = b->hnext;
 104         }
 105 }
 106
 107 struct ieee80211_bss *
 108 ieee80211_rx_bss_add(struct ieee80211_local *local, u8 *bssid, int freq,
 109                      u8 *ssid, u8 ssid_len)
 110 {
 111         struct ieee80211_bss *bss;
 112
 113         bss = kzalloc(sizeof(*bss), GFP_ATOMIC);
 114         if (!bss)
 115                 return NULL;
 116         atomic_set(&bss->users, 2);
 117         memcpy(bss->bssid, bssid, ETH_ALEN);
 118         bss->freq = freq;
 119         if (ssid && ssid_len <= IEEE80211_MAX_SSID_LEN) {
 120                 memcpy(bss->ssid, ssid, ssid_len);
 121                 bss->ssid_len = ssid_len;
 122         }
 123
 124         spin_lock_bh(&local->bss_lock);
 125         /* TODO: order by RSSI? */
 126         list_add_tail(&bss->list, &local->bss_list);
 127         __ieee80211_rx_bss_hash_add(local, bss);
 128         spin_unlock_bh(&local->bss_lock);
 129         return bss;
 130 }
 131
 132 #ifdef CONFIG_MAC80211_MESH
 133 static struct ieee80211_bss *
 134 ieee80211_rx_mesh_bss_get(struct ieee80211_local *local, u8 *mesh_id, int mesh_id_len,
 135                           u8 *mesh_cfg, int freq)
 136 {
 137         struct ieee80211_bss *bss;
 138
 139         spin_lock_bh(&local->bss_lock);
 140         bss = local->bss_hash[mesh_id_hash(mesh_id, mesh_id_len)];
 141         while (bss) {
 142                 if (bss_mesh_cfg(bss) &&
 143                     !memcmp(bss_mesh_cfg(bss), mesh_cfg, MESH_CFG_CMP_LEN) &&
 144                     bss->freq == freq &&
 145                     mesh_id_len == bss->mesh_id_len &&
 146                     (mesh_id_len == 0 || !memcmp(bss->mesh_id, mesh_id,
 147                                                  mesh_id_len))) {
 148                         atomic_inc(&bss->users);
 149                         break;
 150                 }
 151                 bss = bss->hnext;
 152         }
 153         spin_unlock_bh(&local->bss_lock);
 154         return bss;
 155 }
 156
 157 static struct ieee80211_bss *
 158 ieee80211_rx_mesh_bss_add(struct ieee80211_local *local, u8 *mesh_id, int mesh_id_len,
 159                           u8 *mesh_cfg, int mesh_config_len, int freq)
 160 {
 161         struct ieee80211_bss *bss;
 162
 163         if (mesh_config_len != IEEE80211_MESH_CONFIG_LEN)
 164                 return NULL;
 165
 166         bss = kzalloc(sizeof(*bss), GFP_ATOMIC);
 167         if (!bss)
 168                 return NULL;
 169
 170         bss->mesh_cfg = kmalloc(MESH_CFG_CMP_LEN, GFP_ATOMIC);
 171         if (!bss->mesh_cfg) {
 172                 kfree(bss);
 173                 return NULL;
 174         }
 175
 176         if (mesh_id_len && mesh_id_len <= IEEE80211_MAX_MESH_ID_LEN) {
 177                 bss->mesh_id = kmalloc(mesh_id_len, GFP_ATOMIC);
 178                 if (!bss->mesh_id) {
 179                         kfree(bss->mesh_cfg);
 180                         kfree(bss);
 181                         return NULL;
 182                 }
 183                 memcpy(bss->mesh_id, mesh_id, mesh_id_len);
 184         }
 185
 186         atomic_set(&bss->users, 2);
 187         memcpy(bss->mesh_cfg, mesh_cfg, MESH_CFG_CMP_LEN);
 188         bss->mesh_id_len = mesh_id_len;
 189         bss->freq = freq;
 190         spin_lock_bh(&local->bss_lock);
 191         /* TODO: order by RSSI? */
 192         list_add_tail(&bss->list, &local->bss_list);
 193         __ieee80211_rx_bss_hash_add(local, bss);
 194         spin_unlock_bh(&local->bss_lock);
 195         return bss;
 196 }
 197 #endif
 198
 199 static void ieee80211_rx_bss_free(struct ieee80211_bss *bss)
 200 {
 201         kfree(bss->ies);
 202         kfree(bss_mesh_id(bss));
 203         kfree(bss_mesh_cfg(bss));
 204         kfree(bss);
 205 }
 206
 207 void ieee80211_rx_bss_put(struct ieee80211_local *local,
 208                           struct ieee80211_bss *bss)
 209 {
 210         local_bh_disable();
 211         if (!atomic_dec_and_lock(&bss->users, &local->bss_lock)) {
 212                 local_bh_enable();
 213                 return;
 214         }
 215
 216         __ieee80211_rx_bss_hash_del(local, bss);
 217         list_del(&bss->list);
 218         spin_unlock_bh(&local->bss_lock);
 219         ieee80211_rx_bss_free(bss);
 220 }
 221
 222 struct ieee80211_bss *
 223 ieee80211_bss_info_update(struct ieee80211_local *local,
 224                           struct ieee80211_rx_status *rx_status,
 225                           struct ieee80211_mgmt *mgmt,
 226                           size_t len,
 227                           struct ieee802_11_elems *elems,
 228                           int freq, bool beacon)
 229 {
 230         struct ieee80211_bss *bss;
 231         int clen;
 232
 233 #ifdef CONFIG_MAC80211_MESH
 234         if (elems->mesh_config)
 235                 bss = ieee80211_rx_mesh_bss_get(local, elems->mesh_id,
 236                                 elems->mesh_id_len, elems->mesh_config, freq);
 237         else
 238 #endif
 239                 bss = ieee80211_rx_bss_get(local, mgmt->bssid, freq,
 240                                            elems->ssid, elems->ssid_len);
 241         if (!bss) {
 242 #ifdef CONFIG_MAC80211_MESH
 243                 if (elems->mesh_config)
 244                         bss = ieee80211_rx_mesh_bss_add(local, elems->mesh_id,
 245                                 elems->mesh_id_len, elems->mesh_config,
 246                                 elems->mesh_config_len, freq);
 247                 else
 248 #endif
 249                         bss = ieee80211_rx_bss_add(local, mgmt->bssid, freq,
 250                                                   elems->ssid, elems->ssid_len);
 251                 if (!bss)
 252                         return NULL;
 253         } else {
 254 #if 0
 255                 /* TODO: order by RSSI? */
 256                 spin_lock_bh(&local->bss_lock);
 257                 list_move_tail(&bss->list, &local->bss_list);
 258                 spin_unlock_bh(&local->bss_lock);
 259 #endif
 260         }
 261
 262         /* save the ERP value so that it is available at association time */
 263         if (elems->erp_info && elems->erp_info_len >= 1) {
 264                 bss->erp_value = elems->erp_info[0];
 265                 bss->has_erp_value = 1;
 266         }
 267
 268         bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int);
 269         bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info);
 270
 271         if (elems->tim) {
 272                 struct ieee80211_tim_ie *tim_ie =
 273                         (struct ieee80211_tim_ie *)elems->tim;
 274                 bss->dtim_period = tim_ie->dtim_period;
 275         }
 276
 277         /* set default value for buggy APs */
 278         if (!elems->tim || bss->dtim_period == 0)
 279                 bss->dtim_period = 1;
 280
 281         bss->supp_rates_len = 0;
 282         if (elems->supp_rates) {
 283                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 284                 if (clen > elems->supp_rates_len)
 285                         clen = elems->supp_rates_len;
 286                 memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
 287                        clen);
 288                 bss->supp_rates_len += clen;
 289         }
 290         if (elems->ext_supp_rates) {
 291                 clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
 292                 if (clen > elems->ext_supp_rates_len)
 293                         clen = elems->ext_supp_rates_len;
 294                 memcpy(&bss->supp_rates[bss->supp_rates_len],
 295                        elems->ext_supp_rates, clen);
 296                 bss->supp_rates_len += clen;
 297         }
 298
 299         bss->band = rx_status->band;
 300
 301         bss->timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
 302         bss->last_update = jiffies;
 303         bss->signal = rx_status->signal;
 304         bss->noise = rx_status->noise;
 305         bss->qual = rx_status->qual;
 306         bss->wmm_used = elems->wmm_param || elems->wmm_info;
 307
 308         if (!beacon)
 309                 bss->last_probe_resp = jiffies;
 310
 311         /*
 312          * For probe responses, or if we don't have any information yet,
 313          * use the IEs from the beacon.
 314          */
 315         if (!bss->ies || !beacon) {
 316                 if (bss->ies == NULL || bss->ies_len < elems->total_len) {
 317                         kfree(bss->ies);
 318                         bss->ies = kmalloc(elems->total_len, GFP_ATOMIC);
 319                 }
 320                 if (bss->ies) {
 321                         memcpy(bss->ies, elems->ie_start, elems->total_len);
 322                         bss->ies_len = elems->total_len;
 323                 } else
 324                         bss->ies_len = 0;
 325         }
 326
 327         return bss;
 328 }
 329
 330 void ieee80211_rx_bss_remove(struct ieee80211_sub_if_data *sdata, u8 *bssid,
 331                              int freq, u8 *ssid, u8 ssid_len)
 332 {
 333         struct ieee80211_bss *bss;
 334         struct ieee80211_local *local = sdata->local;
 335
 336         bss = ieee80211_rx_bss_get(local, bssid, freq, ssid, ssid_len);
 337         if (bss) {
 338                 atomic_dec(&bss->users);
 339                 ieee80211_rx_bss_put(local, bss);
 340         }
 341 }
 342
 343 ieee80211_rx_result
 344 ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 345                   struct ieee80211_rx_status *rx_status)
 346 {
 347         struct ieee80211_mgmt *mgmt;
 348         struct ieee80211_bss *bss;
 349         u8 *elements;
 350         struct ieee80211_channel *channel;
 351         size_t baselen;
 352         int freq;
 353         __le16 fc;
 354         bool presp, beacon = false;
 355         struct ieee802_11_elems elems;
 356
 357         if (skb->len < 2)
 358                 return RX_DROP_UNUSABLE;
 359
 360         mgmt = (struct ieee80211_mgmt *) skb->data;
 361         fc = mgmt->frame_control;
 362
 363         if (ieee80211_is_ctl(fc))
 364                 return RX_CONTINUE;
 365
 366         if (skb->len < 24)
 367                 return RX_DROP_MONITOR;
 368
 369         presp = ieee80211_is_probe_resp(fc);
 370         if (presp) {
 371                 /* ignore ProbeResp to foreign address */
 372                 if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
 373                         return RX_DROP_MONITOR;
 374
 375                 presp = true;
 376                 elements = mgmt->u.probe_resp.variable;
 377                 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
 378         } else {
 379                 beacon = ieee80211_is_beacon(fc);
 380                 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 381                 elements = mgmt->u.beacon.variable;
 382         }
 383
 384         if (!presp && !beacon)
 385                 return RX_CONTINUE;
 386
 387         if (baselen > skb->len)
 388                 return RX_DROP_MONITOR;
 389
 390         ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
 391
 392         if (elems.ds_params && elems.ds_params_len == 1)
 393                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 394         else
 395                 freq = rx_status->freq;
 396
 397         channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
 398
 399         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 400                 return RX_DROP_MONITOR;
 401
 402         bss = ieee80211_bss_info_update(sdata->local, rx_status,
 403                                         mgmt, skb->len, &elems,
 404                                         freq, beacon);
 405         if (bss)
 406                 ieee80211_rx_bss_put(sdata->local, bss);
 407
 408         dev_kfree_skb(skb);
 409         return RX_QUEUED;
 410 }
 411
 412 void ieee80211_send_nullfunc(struct ieee80211_local *local,
 413                                     struct ieee80211_sub_if_data *sdata,
 414                                     int powersave)
 415 {
 416         struct sk_buff *skb;
 417         struct ieee80211_hdr *nullfunc;
 418         __le16 fc;
 419
 420         skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
 421         if (!skb) {
 422                 printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
 423                        "frame\n", sdata->dev->name);
 424                 return;
 425         }
 426         skb_reserve(skb, local->hw.extra_tx_headroom);
 427
 428         nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
 429         memset(nullfunc, 0, 24);
 430         fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
 431                          IEEE80211_FCTL_TODS);
 432         if (powersave)
 433                 fc |= cpu_to_le16(IEEE80211_FCTL_PM);
 434         nullfunc->frame_control = fc;
 435         memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
 436         memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
 437         memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);
 438
 439         ieee80211_tx_skb(sdata, skb, 0);
 440 }
 441
 442 void ieee80211_scan_completed(struct ieee80211_hw *hw)
 443 {
 444         struct ieee80211_local *local = hw_to_local(hw);
 445         struct ieee80211_sub_if_data *sdata;
 446         union iwreq_data wrqu;
 447
 448         if (WARN_ON(!local->hw_scanning && !local->sw_scanning))
 449                 return;
 450
 451         local->last_scan_completed = jiffies;
 452         memset(&wrqu, 0, sizeof(wrqu));
 453
 454         /*
 455          * local->scan_sdata could have been NULLed by the interface
 456          * down code in case we were scanning on an interface that is
 457          * being taken down.
 458          */
 459         sdata = local->scan_sdata;
 460         if (sdata)
 461                 wireless_send_event(sdata->dev, SIOCGIWSCAN, &wrqu, NULL);
 462
 463         if (local->hw_scanning) {
 464                 local->hw_scanning = false;
 465                 /*
 466                  * Somebody might have requested channel change during scan
 467                  * that we won't have acted upon, try now. ieee80211_hw_config
 468                  * will set the flag based on actual changes.
 469                  */
 470                 ieee80211_hw_config(local, 0);
 471                 goto done;
 472         }
 473
 474         local->sw_scanning = false;
 475         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 476
 477         netif_tx_lock_bh(local->mdev);
 478         netif_addr_lock(local->mdev);
 479         local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
 480         local->ops->configure_filter(local_to_hw(local),
 481                                      FIF_BCN_PRBRESP_PROMISC,
 482                                      &local->filter_flags,
 483                                      local->mdev->mc_count,
 484                                      local->mdev->mc_list);
 485
 486         netif_addr_unlock(local->mdev);
 487         netif_tx_unlock_bh(local->mdev);
 488
 489         mutex_lock(&local->iflist_mtx);
 490         list_for_each_entry(sdata, &local->interfaces, list) {
 491                 if (!netif_running(sdata->dev))
 492                         continue;
 493
 494                 /* Tell AP we're back */
 495                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 496                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 497                                 ieee80211_send_nullfunc(local, sdata, 0);
 498                                 netif_tx_wake_all_queues(sdata->dev);
 499                         }
 500                 } else
 501                         netif_tx_wake_all_queues(sdata->dev);
 502
 503                 ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 504         }
 505         mutex_unlock(&local->iflist_mtx);
 506
 507  done:
 508         ieee80211_mlme_notify_scan_completed(local);
 509         ieee80211_mesh_notify_scan_completed(local);
 510 }
 511 EXPORT_SYMBOL(ieee80211_scan_completed);
 512
 513 void ieee80211_scan_work(struct work_struct *work)
 514 {
 515         struct ieee80211_local *local =
 516                 container_of(work, struct ieee80211_local, scan_work.work);
 517         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 518         struct ieee80211_supported_band *sband;
 519         struct ieee80211_channel *chan;
 520         int skip;
 521         unsigned long next_delay = 0;
 522
 523         /*
 524          * Avoid re-scheduling when the sdata is going away.
 525          */
 526         if (!netif_running(sdata->dev))
 527                 return;
 528
 529         switch (local->scan_state) {
 530         case SCAN_SET_CHANNEL:
 531                 /*
 532                  * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
 533                  * after we successfully scanned the last channel of the last
 534                  * band (and the last band is supported by the hw)
 535                  */
 536                 if (local->scan_band < IEEE80211_NUM_BANDS)
 537                         sband = local->hw.wiphy->bands[local->scan_band];
 538                 else
 539                         sband = NULL;
 540
 541                 /*
 542                  * If we are at an unsupported band and have more bands
 543                  * left to scan, advance to the next supported one.
 544                  */
 545                 while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
 546                         local->scan_band++;
 547                         sband = local->hw.wiphy->bands[local->scan_band];
 548                         local->scan_channel_idx = 0;
 549                 }
 550
 551                 /* if no more bands/channels left, complete scan */
 552                 if (!sband || local->scan_channel_idx >= sband->n_channels) {
 553                         ieee80211_scan_completed(local_to_hw(local));
 554                         return;
 555                 }
 556                 skip = 0;
 557                 chan = &sband->channels[local->scan_channel_idx];
 558
 559                 if (chan->flags & IEEE80211_CHAN_DISABLED ||
 560                     (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 561                      chan->flags & IEEE80211_CHAN_NO_IBSS))
 562                         skip = 1;
 563
 564                 if (!skip) {
 565                         local->scan_channel = chan;
 566                         if (ieee80211_hw_config(local,
 567                                                 IEEE80211_CONF_CHANGE_CHANNEL))
 568                                 skip = 1;
 569                 }
 570
 571                 /* advance state machine to next channel/band */
 572                 local->scan_channel_idx++;
 573                 if (local->scan_channel_idx >= sband->n_channels) {
 574                         /*
 575                          * scan_band may end up == IEEE80211_NUM_BANDS, but
 576                          * we'll catch that case above and complete the scan
 577                          * if that is the case.
 578                          */
 579                         local->scan_band++;
 580                         local->scan_channel_idx = 0;
 581                 }
 582
 583                 if (skip)
 584                         break;
 585
 586                 next_delay = IEEE80211_PROBE_DELAY +
 587                              usecs_to_jiffies(local->hw.channel_change_time);
 588                 local->scan_state = SCAN_SEND_PROBE;
 589                 break;
 590         case SCAN_SEND_PROBE:
 591                 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 592                 local->scan_state = SCAN_SET_CHANNEL;
 593
 594                 if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 595                         break;
 596                 ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
 597                                          local->scan_ssid_len);
 598                 next_delay = IEEE80211_CHANNEL_TIME;
 599                 break;
 600         }
 601
 602         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 603                            next_delay);
 604 }
 605
 606
 607 int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 608                          u8 *ssid, size_t ssid_len)
 609 {
 610         struct ieee80211_local *local = scan_sdata->local;
 611         struct ieee80211_sub_if_data *sdata;
 612
 613         if (ssid_len > IEEE80211_MAX_SSID_LEN)
 614                 return -EINVAL;
 615
 616         /* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
 617          * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
 618          * BSSID: MACAddress
 619          * SSID
 620          * ScanType: ACTIVE, PASSIVE
 621          * ProbeDelay: delay (in microseconds) to be used prior to transmitting
 622          *    a Probe frame during active scanning
 623          * ChannelList
 624          * MinChannelTime (>= ProbeDelay), in TU
 625          * MaxChannelTime: (>= MinChannelTime), in TU
 626          */
 627
 628          /* MLME-SCAN.confirm
 629           * BSSDescriptionSet
 630           * ResultCode: SUCCESS, INVALID_PARAMETERS
 631          */
 632
 633         if (local->sw_scanning || local->hw_scanning) {
 634                 if (local->scan_sdata == scan_sdata)
 635                         return 0;
 636                 return -EBUSY;
 637         }
 638
 639         if (local->ops->hw_scan) {
 640                 int rc;
 641
 642                 local->hw_scanning = true;
 643                 rc = local->ops->hw_scan(local_to_hw(local), ssid, ssid_len);
 644                 if (rc) {
 645                         local->hw_scanning = false;
 646                         return rc;
 647                 }
 648                 local->scan_sdata = scan_sdata;
 649                 return 0;
 650         }
 651
 652         local->sw_scanning = true;
 653
 654         mutex_lock(&local->iflist_mtx);
 655         list_for_each_entry(sdata, &local->interfaces, list) {
 656                 if (!netif_running(sdata->dev))
 657                         continue;
 658
 659                 ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);
 660
 661                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 662                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 663                                 netif_tx_stop_all_queues(sdata->dev);
 664                                 ieee80211_send_nullfunc(local, sdata, 1);
 665                         }
 666                 } else
 667                         netif_tx_stop_all_queues(sdata->dev);
 668         }
 669         mutex_unlock(&local->iflist_mtx);
 670
 671         if (ssid) {
 672                 local->scan_ssid_len = ssid_len;
 673                 memcpy(local->scan_ssid, ssid, ssid_len);
 674         } else
 675                 local->scan_ssid_len = 0;
 676         local->scan_state = SCAN_SET_CHANNEL;
 677         local->scan_channel_idx = 0;
 678         local->scan_band = IEEE80211_BAND_2GHZ;
 679         local->scan_sdata = scan_sdata;
 680
 681         netif_addr_lock_bh(local->mdev);
 682         local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
 683         local->ops->configure_filter(local_to_hw(local),
 684                                      FIF_BCN_PRBRESP_PROMISC,
 685                                      &local->filter_flags,
 686                                      local->mdev->mc_count,
 687                                      local->mdev->mc_list);
 688         netif_addr_unlock_bh(local->mdev);
 689
 690         /* TODO: start scan as soon as all nullfunc frames are ACKed */
 691         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 692                            IEEE80211_CHANNEL_TIME);
 693
 694         return 0;
 695 }
 696
 697
 698 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 699                            u8 *ssid, size_t ssid_len)
 700 {
 701         struct ieee80211_local *local = sdata->local;
 702         struct ieee80211_if_sta *ifsta;
 703
 704         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 705                 return ieee80211_start_scan(sdata, ssid, ssid_len);
 706
 707         /*
 708          * STA has a state machine that might need to defer scanning
 709          * while it's trying to associate/authenticate, therefore we
 710          * queue it up to the state machine in that case.
 711          */
 712
 713         if (local->sw_scanning || local->hw_scanning) {
 714                 if (local->scan_sdata == sdata)
 715                         return 0;
 716                 return -EBUSY;
 717         }
 718
 719         ifsta = &sdata->u.sta;
 720
 721         ifsta->scan_ssid_len = ssid_len;
 722         if (ssid_len)
 723                 memcpy(ifsta->scan_ssid, ssid, ssid_len);
 724         set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
 725         queue_work(local->hw.workqueue, &ifsta->work);
 726
 727         return 0;
 728 }
 729
 730
 731 static void ieee80211_scan_add_ies(struct iw_request_info *info,
 732                                    struct ieee80211_bss *bss,
 733                                    char **current_ev, char *end_buf)
 734 {
 735         u8 *pos, *end, *next;
 736         struct iw_event iwe;
 737
 738         if (bss == NULL || bss->ies == NULL)
 739                 return;
 740
 741         /*
 742          * If needed, fragment the IEs buffer (at IE boundaries) into short
 743          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 744          */
 745         pos = bss->ies;
 746         end = pos + bss->ies_len;
 747
 748         while (end - pos > IW_GENERIC_IE_MAX) {
 749                 next = pos + 2 + pos[1];
 750                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 751                         next = next + 2 + next[1];
 752
 753                 memset(&iwe, 0, sizeof(iwe));
 754                 iwe.cmd = IWEVGENIE;
 755                 iwe.u.data.length = next - pos;
 756                 *current_ev = iwe_stream_add_point(info, *current_ev,
 757                                                    end_buf, &iwe, pos);
 758
 759                 pos = next;
 760         }
 761
 762         if (end > pos) {
 763                 memset(&iwe, 0, sizeof(iwe));
 764                 iwe.cmd = IWEVGENIE;
 765                 iwe.u.data.length = end - pos;
 766                 *current_ev = iwe_stream_add_point(info, *current_ev,
 767                                                    end_buf, &iwe, pos);
 768         }
 769 }
 770
 771
 772 static char *
 773 ieee80211_scan_result(struct ieee80211_local *local,
 774                       struct iw_request_info *info,
 775                       struct ieee80211_bss *bss,
 776                       char *current_ev, char *end_buf)
 777 {
 778         struct iw_event iwe;
 779         char *buf;
 780
 781         if (time_after(jiffies,
 782                        bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
 783                 return current_ev;
 784
 785         memset(&iwe, 0, sizeof(iwe));
 786         iwe.cmd = SIOCGIWAP;
 787         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 788         memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
 789         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 790                                           IW_EV_ADDR_LEN);
 791
 792         memset(&iwe, 0, sizeof(iwe));
 793         iwe.cmd = SIOCGIWESSID;
 794         if (bss_mesh_cfg(bss)) {
 795                 iwe.u.data.length = bss_mesh_id_len(bss);
 796                 iwe.u.data.flags = 1;
 797                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 798                                                   &iwe, bss_mesh_id(bss));
 799         } else {
 800                 iwe.u.data.length = bss->ssid_len;
 801                 iwe.u.data.flags = 1;
 802                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 803                                                   &iwe, bss->ssid);
 804         }
 805
 806         if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 807             || bss_mesh_cfg(bss)) {
 808                 memset(&iwe, 0, sizeof(iwe));
 809                 iwe.cmd = SIOCGIWMODE;
 810                 if (bss_mesh_cfg(bss))
 811                         iwe.u.mode = IW_MODE_MESH;
 812                 else if (bss->capability & WLAN_CAPABILITY_ESS)
 813                         iwe.u.mode = IW_MODE_MASTER;
 814                 else
 815                         iwe.u.mode = IW_MODE_ADHOC;
 816                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 817                                                   &iwe, IW_EV_UINT_LEN);
 818         }
 819
 820         memset(&iwe, 0, sizeof(iwe));
 821         iwe.cmd = SIOCGIWFREQ;
 822         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
 823         iwe.u.freq.e = 0;
 824         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 825                                           IW_EV_FREQ_LEN);
 826
 827         memset(&iwe, 0, sizeof(iwe));
 828         iwe.cmd = SIOCGIWFREQ;
 829         iwe.u.freq.m = bss->freq;
 830         iwe.u.freq.e = 6;
 831         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 832                                           IW_EV_FREQ_LEN);
 833         memset(&iwe, 0, sizeof(iwe));
 834         iwe.cmd = IWEVQUAL;
 835         iwe.u.qual.qual = bss->qual;
 836         iwe.u.qual.level = bss->signal;
 837         iwe.u.qual.noise = bss->noise;
 838         iwe.u.qual.updated = local->wstats_flags;
 839         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 840                                           IW_EV_QUAL_LEN);
 841
 842         memset(&iwe, 0, sizeof(iwe));
 843         iwe.cmd = SIOCGIWENCODE;
 844         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 845                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 846         else
 847                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 848         iwe.u.data.length = 0;
 849         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 850                                           &iwe, "");
 851
 852         ieee80211_scan_add_ies(info, bss, &current_ev, end_buf);
 853
 854         if (bss->supp_rates_len > 0) {
 855                 /* display all supported rates in readable format */
 856                 char *p = current_ev + iwe_stream_lcp_len(info);
 857                 int i;
 858
 859                 memset(&iwe, 0, sizeof(iwe));
 860                 iwe.cmd = SIOCGIWRATE;
 861                 /* Those two flags are ignored... */
 862                 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 863
 864                 for (i = 0; i < bss->supp_rates_len; i++) {
 865                         iwe.u.bitrate.value = ((bss->supp_rates[i] &
 866                                                         0x7f) * 500000);
 867                         p = iwe_stream_add_value(info, current_ev, p,
 868                                         end_buf, &iwe, IW_EV_PARAM_LEN);
 869                 }
 870                 current_ev = p;
 871         }
 872
 873         buf = kmalloc(30, GFP_ATOMIC);
 874         if (buf) {
 875                 memset(&iwe, 0, sizeof(iwe));
 876                 iwe.cmd = IWEVCUSTOM;
 877                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
 878                 iwe.u.data.length = strlen(buf);
 879                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 880                                                   &iwe, buf);
 881                 memset(&iwe, 0, sizeof(iwe));
 882                 iwe.cmd = IWEVCUSTOM;
 883                 sprintf(buf, " Last beacon: %dms ago",
 884                         jiffies_to_msecs(jiffies - bss->last_update));
 885                 iwe.u.data.length = strlen(buf);
 886                 current_ev = iwe_stream_add_point(info, current_ev,
 887                                                   end_buf, &iwe, buf);
 888                 kfree(buf);
 889         }
 890
 891         if (bss_mesh_cfg(bss)) {
 892                 u8 *cfg = bss_mesh_cfg(bss);
 893                 buf = kmalloc(50, GFP_ATOMIC);
 894                 if (buf) {
 895                         memset(&iwe, 0, sizeof(iwe));
 896                         iwe.cmd = IWEVCUSTOM;
 897                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 898                         iwe.u.data.length = strlen(buf);
 899                         current_ev = iwe_stream_add_point(info, current_ev,
 900                                                           end_buf,
 901                                                           &iwe, buf);
 902                         sprintf(buf, "Path Selection Protocol ID: "
 903                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 904                                                         cfg[4]);
 905                         iwe.u.data.length = strlen(buf);
 906                         current_ev = iwe_stream_add_point(info, current_ev,
 907                                                           end_buf,
 908                                                           &iwe, buf);
 909                         sprintf(buf, "Path Selection Metric ID: "
 910                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 911                                                         cfg[8]);
 912                         iwe.u.data.length = strlen(buf);
 913                         current_ev = iwe_stream_add_point(info, current_ev,
 914                                                           end_buf,
 915                                                           &iwe, buf);
 916                         sprintf(buf, "Congestion Control Mode ID: "
 917                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 918                                                         cfg[11], cfg[12]);
 919                         iwe.u.data.length = strlen(buf);
 920                         current_ev = iwe_stream_add_point(info, current_ev,
 921                                                           end_buf,
 922                                                           &iwe, buf);
 923                         sprintf(buf, "Channel Precedence: "
 924                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 925                                                         cfg[15], cfg[16]);
 926                         iwe.u.data.length = strlen(buf);
 927                         current_ev = iwe_stream_add_point(info, current_ev,
 928                                                           end_buf,
 929                                                           &iwe, buf);
 930                         kfree(buf);
 931                 }
 932         }
 933
 934         return current_ev;
 935 }
 936
 937
 938 int ieee80211_scan_results(struct ieee80211_local *local,
 939                            struct iw_request_info *info,
 940                            char *buf, size_t len)
 941 {
 942         char *current_ev = buf;
 943         char *end_buf = buf + len;
 944         struct ieee80211_bss *bss;
 945
 946         spin_lock_bh(&local->bss_lock);
 947         list_for_each_entry(bss, &local->bss_list, list) {
 948                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 949                         spin_unlock_bh(&local->bss_lock);
 950                         return -E2BIG;
 951                 }
 952                 current_ev = ieee80211_scan_result(local, info, bss,
 953                                                        current_ev, end_buf);
 954         }
 955         spin_unlock_bh(&local->bss_lock);
 956         return current_ev - buf;
 957 }