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

   1 /*
   2  * BSS client mode implementation
   3  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   4  * Copyright 2004, Instant802 Networks, Inc.
   5  * Copyright 2005, Devicescape Software, Inc.
   6  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/wireless.h>
  15 #include <linux/if_arp.h>
  16 #include <net/mac80211.h>
  17 #include <net/iw_handler.h>
  18
  19 #include "ieee80211_i.h"
  20
  21 #define IEEE80211_PROBE_DELAY (HZ / 33)
  22 #define IEEE80211_CHANNEL_TIME (HZ / 33)
  23 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
  24
  25
  26 static void ieee80211_send_nullfunc(struct ieee80211_local *local,
  27                                     struct ieee80211_sub_if_data *sdata,
  28                                     int powersave)
  29 {
  30         struct sk_buff *skb;
  31         struct ieee80211_hdr *nullfunc;
  32         __le16 fc;
  33
  34         skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24);
  35         if (!skb) {
  36                 printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
  37                        "frame\n", sdata->dev->name);
  38                 return;
  39         }
  40         skb_reserve(skb, local->hw.extra_tx_headroom);
  41
  42         nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
  43         memset(nullfunc, 0, 24);
  44         fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
  45                          IEEE80211_FCTL_TODS);
  46         if (powersave)
  47                 fc |= cpu_to_le16(IEEE80211_FCTL_PM);
  48         nullfunc->frame_control = fc;
  49         memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN);
  50         memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
  51         memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN);
  52
  53         ieee80211_sta_tx(sdata, skb, 0);
  54 }
  55
  56 static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
  57 {
  58         if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
  59             ieee80211_vif_is_mesh(&sdata->vif))
  60                 ieee80211_sta_timer((unsigned long)sdata);
  61 }
  62
  63 void ieee80211_scan_completed(struct ieee80211_hw *hw)
  64 {
  65         struct ieee80211_local *local = hw_to_local(hw);
  66         struct ieee80211_sub_if_data *sdata;
  67         union iwreq_data wrqu;
  68
  69         local->last_scan_completed = jiffies;
  70         memset(&wrqu, 0, sizeof(wrqu));
  71         wireless_send_event(local->scan_sdata->dev, SIOCGIWSCAN, &wrqu, NULL);
  72
  73         if (local->sta_hw_scanning) {
  74                 local->sta_hw_scanning = 0;
  75                 if (ieee80211_hw_config(local))
  76                         printk(KERN_DEBUG "%s: failed to restore operational "
  77                                "channel after scan\n", wiphy_name(local->hw.wiphy));
  78                 /* Restart STA timer for HW scan case */
  79                 rcu_read_lock();
  80                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
  81                         ieee80211_restart_sta_timer(sdata);
  82                 rcu_read_unlock();
  83
  84                 goto done;
  85         }
  86
  87         local->sta_sw_scanning = 0;
  88         if (ieee80211_hw_config(local))
  89                 printk(KERN_DEBUG "%s: failed to restore operational "
  90                        "channel after scan\n", wiphy_name(local->hw.wiphy));
  91
  92
  93         netif_tx_lock_bh(local->mdev);
  94         netif_addr_lock(local->mdev);
  95         local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC;
  96         local->ops->configure_filter(local_to_hw(local),
  97                                      FIF_BCN_PRBRESP_PROMISC,
  98                                      &local->filter_flags,
  99                                      local->mdev->mc_count,
 100                                      local->mdev->mc_list);
 101
 102         netif_addr_unlock(local->mdev);
 103         netif_tx_unlock_bh(local->mdev);
 104
 105         rcu_read_lock();
 106         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 107                 /* Tell AP we're back */
 108                 if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
 109                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 110                                 ieee80211_send_nullfunc(local, sdata, 0);
 111                                 netif_tx_wake_all_queues(sdata->dev);
 112                         }
 113                 } else
 114                         netif_tx_wake_all_queues(sdata->dev);
 115
 116                 ieee80211_restart_sta_timer(sdata);
 117         }
 118         rcu_read_unlock();
 119
 120  done:
 121         ieee80211_mlme_notify_scan_completed(local);
 122 }
 123 EXPORT_SYMBOL(ieee80211_scan_completed);
 124
 125
 126 void ieee80211_sta_scan_work(struct work_struct *work)
 127 {
 128         struct ieee80211_local *local =
 129                 container_of(work, struct ieee80211_local, scan_work.work);
 130         struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 131         struct ieee80211_supported_band *sband;
 132         struct ieee80211_channel *chan;
 133         int skip;
 134         unsigned long next_delay = 0;
 135
 136         if (!local->sta_sw_scanning)
 137                 return;
 138
 139         switch (local->scan_state) {
 140         case SCAN_SET_CHANNEL:
 141                 /*
 142                  * Get current scan band. scan_band may be IEEE80211_NUM_BANDS
 143                  * after we successfully scanned the last channel of the last
 144                  * band (and the last band is supported by the hw)
 145                  */
 146                 if (local->scan_band < IEEE80211_NUM_BANDS)
 147                         sband = local->hw.wiphy->bands[local->scan_band];
 148                 else
 149                         sband = NULL;
 150
 151                 /*
 152                  * If we are at an unsupported band and have more bands
 153                  * left to scan, advance to the next supported one.
 154                  */
 155                 while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) {
 156                         local->scan_band++;
 157                         sband = local->hw.wiphy->bands[local->scan_band];
 158                         local->scan_channel_idx = 0;
 159                 }
 160
 161                 /* if no more bands/channels left, complete scan */
 162                 if (!sband || local->scan_channel_idx >= sband->n_channels) {
 163                         ieee80211_scan_completed(local_to_hw(local));
 164                         return;
 165                 }
 166                 skip = 0;
 167                 chan = &sband->channels[local->scan_channel_idx];
 168
 169                 if (chan->flags & IEEE80211_CHAN_DISABLED ||
 170                     (sdata->vif.type == IEEE80211_IF_TYPE_IBSS &&
 171                      chan->flags & IEEE80211_CHAN_NO_IBSS))
 172                         skip = 1;
 173
 174                 if (!skip) {
 175                         local->scan_channel = chan;
 176                         if (ieee80211_hw_config(local)) {
 177                                 printk(KERN_DEBUG "%s: failed to set freq to "
 178                                        "%d MHz for scan\n", wiphy_name(local->hw.wiphy),
 179                                        chan->center_freq);
 180                                 skip = 1;
 181                         }
 182                 }
 183
 184                 /* advance state machine to next channel/band */
 185                 local->scan_channel_idx++;
 186                 if (local->scan_channel_idx >= sband->n_channels) {
 187                         /*
 188                          * scan_band may end up == IEEE80211_NUM_BANDS, but
 189                          * we'll catch that case above and complete the scan
 190                          * if that is the case.
 191                          */
 192                         local->scan_band++;
 193                         local->scan_channel_idx = 0;
 194                 }
 195
 196                 if (skip)
 197                         break;
 198
 199                 next_delay = IEEE80211_PROBE_DELAY +
 200                              usecs_to_jiffies(local->hw.channel_change_time);
 201                 local->scan_state = SCAN_SEND_PROBE;
 202                 break;
 203         case SCAN_SEND_PROBE:
 204                 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 205                 local->scan_state = SCAN_SET_CHANNEL;
 206
 207                 if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 208                         break;
 209                 ieee80211_send_probe_req(sdata, NULL, local->scan_ssid,
 210                                          local->scan_ssid_len);
 211                 next_delay = IEEE80211_CHANNEL_TIME;
 212                 break;
 213         }
 214
 215         if (local->sta_sw_scanning)
 216                 queue_delayed_work(local->hw.workqueue, &local->scan_work,
 217                                    next_delay);
 218 }
 219
 220
 221 int ieee80211_sta_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 222                              u8 *ssid, size_t ssid_len)
 223 {
 224         struct ieee80211_local *local = scan_sdata->local;
 225         struct ieee80211_sub_if_data *sdata;
 226
 227         if (ssid_len > IEEE80211_MAX_SSID_LEN)
 228                 return -EINVAL;
 229
 230         /* MLME-SCAN.request (page 118)  page 144 (11.1.3.1)
 231          * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS
 232          * BSSID: MACAddress
 233          * SSID
 234          * ScanType: ACTIVE, PASSIVE
 235          * ProbeDelay: delay (in microseconds) to be used prior to transmitting
 236          *    a Probe frame during active scanning
 237          * ChannelList
 238          * MinChannelTime (>= ProbeDelay), in TU
 239          * MaxChannelTime: (>= MinChannelTime), in TU
 240          */
 241
 242          /* MLME-SCAN.confirm
 243           * BSSDescriptionSet
 244           * ResultCode: SUCCESS, INVALID_PARAMETERS
 245          */
 246
 247         if (local->sta_sw_scanning || local->sta_hw_scanning) {
 248                 if (local->scan_sdata == scan_sdata)
 249                         return 0;
 250                 return -EBUSY;
 251         }
 252
 253         if (local->ops->hw_scan) {
 254                 int rc = local->ops->hw_scan(local_to_hw(local),
 255                                              ssid, ssid_len);
 256                 if (!rc) {
 257                         local->sta_hw_scanning = 1;
 258                         local->scan_sdata = scan_sdata;
 259                 }
 260                 return rc;
 261         }
 262
 263         local->sta_sw_scanning = 1;
 264
 265         rcu_read_lock();
 266         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 267                 if (sdata->vif.type == IEEE80211_IF_TYPE_STA) {
 268                         if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
 269                                 netif_tx_stop_all_queues(sdata->dev);
 270                                 ieee80211_send_nullfunc(local, sdata, 1);
 271                         }
 272                 } else
 273                         netif_tx_stop_all_queues(sdata->dev);
 274         }
 275         rcu_read_unlock();
 276
 277         if (ssid) {
 278                 local->scan_ssid_len = ssid_len;
 279                 memcpy(local->scan_ssid, ssid, ssid_len);
 280         } else
 281                 local->scan_ssid_len = 0;
 282         local->scan_state = SCAN_SET_CHANNEL;
 283         local->scan_channel_idx = 0;
 284         local->scan_band = IEEE80211_BAND_2GHZ;
 285         local->scan_sdata = scan_sdata;
 286
 287         netif_addr_lock_bh(local->mdev);
 288         local->filter_flags |= FIF_BCN_PRBRESP_PROMISC;
 289         local->ops->configure_filter(local_to_hw(local),
 290                                      FIF_BCN_PRBRESP_PROMISC,
 291                                      &local->filter_flags,
 292                                      local->mdev->mc_count,
 293                                      local->mdev->mc_list);
 294         netif_addr_unlock_bh(local->mdev);
 295
 296         /* TODO: start scan as soon as all nullfunc frames are ACKed */
 297         queue_delayed_work(local->hw.workqueue, &local->scan_work,
 298                            IEEE80211_CHANNEL_TIME);
 299
 300         return 0;
 301 }
 302
 303
 304 int ieee80211_sta_req_scan(struct ieee80211_sub_if_data *sdata, u8 *ssid, size_t ssid_len)
 305 {
 306         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
 307         struct ieee80211_local *local = sdata->local;
 308
 309         if (sdata->vif.type != IEEE80211_IF_TYPE_STA)
 310                 return ieee80211_sta_start_scan(sdata, ssid, ssid_len);
 311
 312         if (local->sta_sw_scanning || local->sta_hw_scanning) {
 313                 if (local->scan_sdata == sdata)
 314                         return 0;
 315                 return -EBUSY;
 316         }
 317
 318         ifsta->scan_ssid_len = ssid_len;
 319         if (ssid_len)
 320                 memcpy(ifsta->scan_ssid, ssid, ssid_len);
 321         set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request);
 322         queue_work(local->hw.workqueue, &ifsta->work);
 323         return 0;
 324 }
 325
 326
 327 static void ieee80211_sta_add_scan_ies(struct iw_request_info *info,
 328                                        struct ieee80211_sta_bss *bss,
 329                                        char **current_ev, char *end_buf)
 330 {
 331         u8 *pos, *end, *next;
 332         struct iw_event iwe;
 333
 334         if (bss == NULL || bss->ies == NULL)
 335                 return;
 336
 337         /*
 338          * If needed, fragment the IEs buffer (at IE boundaries) into short
 339          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
 340          */
 341         pos = bss->ies;
 342         end = pos + bss->ies_len;
 343
 344         while (end - pos > IW_GENERIC_IE_MAX) {
 345                 next = pos + 2 + pos[1];
 346                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
 347                         next = next + 2 + next[1];
 348
 349                 memset(&iwe, 0, sizeof(iwe));
 350                 iwe.cmd = IWEVGENIE;
 351                 iwe.u.data.length = next - pos;
 352                 *current_ev = iwe_stream_add_point(info, *current_ev,
 353                                                    end_buf, &iwe, pos);
 354
 355                 pos = next;
 356         }
 357
 358         if (end > pos) {
 359                 memset(&iwe, 0, sizeof(iwe));
 360                 iwe.cmd = IWEVGENIE;
 361                 iwe.u.data.length = end - pos;
 362                 *current_ev = iwe_stream_add_point(info, *current_ev,
 363                                                    end_buf, &iwe, pos);
 364         }
 365 }
 366
 367
 368 static char *
 369 ieee80211_sta_scan_result(struct ieee80211_local *local,
 370                           struct iw_request_info *info,
 371                           struct ieee80211_sta_bss *bss,
 372                           char *current_ev, char *end_buf)
 373 {
 374         struct iw_event iwe;
 375         char *buf;
 376
 377         if (time_after(jiffies,
 378                        bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE))
 379                 return current_ev;
 380
 381         memset(&iwe, 0, sizeof(iwe));
 382         iwe.cmd = SIOCGIWAP;
 383         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 384         memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN);
 385         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 386                                           IW_EV_ADDR_LEN);
 387
 388         memset(&iwe, 0, sizeof(iwe));
 389         iwe.cmd = SIOCGIWESSID;
 390         if (bss_mesh_cfg(bss)) {
 391                 iwe.u.data.length = bss_mesh_id_len(bss);
 392                 iwe.u.data.flags = 1;
 393                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 394                                                   &iwe, bss_mesh_id(bss));
 395         } else {
 396                 iwe.u.data.length = bss->ssid_len;
 397                 iwe.u.data.flags = 1;
 398                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 399                                                   &iwe, bss->ssid);
 400         }
 401
 402         if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
 403             || bss_mesh_cfg(bss)) {
 404                 memset(&iwe, 0, sizeof(iwe));
 405                 iwe.cmd = SIOCGIWMODE;
 406                 if (bss_mesh_cfg(bss))
 407                         iwe.u.mode = IW_MODE_MESH;
 408                 else if (bss->capability & WLAN_CAPABILITY_ESS)
 409                         iwe.u.mode = IW_MODE_MASTER;
 410                 else
 411                         iwe.u.mode = IW_MODE_ADHOC;
 412                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
 413                                                   &iwe, IW_EV_UINT_LEN);
 414         }
 415
 416         memset(&iwe, 0, sizeof(iwe));
 417         iwe.cmd = SIOCGIWFREQ;
 418         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq);
 419         iwe.u.freq.e = 0;
 420         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 421                                           IW_EV_FREQ_LEN);
 422
 423         memset(&iwe, 0, sizeof(iwe));
 424         iwe.cmd = SIOCGIWFREQ;
 425         iwe.u.freq.m = bss->freq;
 426         iwe.u.freq.e = 6;
 427         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 428                                           IW_EV_FREQ_LEN);
 429         memset(&iwe, 0, sizeof(iwe));
 430         iwe.cmd = IWEVQUAL;
 431         iwe.u.qual.qual = bss->qual;
 432         iwe.u.qual.level = bss->signal;
 433         iwe.u.qual.noise = bss->noise;
 434         iwe.u.qual.updated = local->wstats_flags;
 435         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
 436                                           IW_EV_QUAL_LEN);
 437
 438         memset(&iwe, 0, sizeof(iwe));
 439         iwe.cmd = SIOCGIWENCODE;
 440         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 441                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 442         else
 443                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 444         iwe.u.data.length = 0;
 445         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 446                                           &iwe, "");
 447
 448         ieee80211_sta_add_scan_ies(info, bss, &current_ev, end_buf);
 449
 450         if (bss->supp_rates_len > 0) {
 451                 /* display all supported rates in readable format */
 452                 char *p = current_ev + iwe_stream_lcp_len(info);
 453                 int i;
 454
 455                 memset(&iwe, 0, sizeof(iwe));
 456                 iwe.cmd = SIOCGIWRATE;
 457                 /* Those two flags are ignored... */
 458                 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
 459
 460                 for (i = 0; i < bss->supp_rates_len; i++) {
 461                         iwe.u.bitrate.value = ((bss->supp_rates[i] &
 462                                                         0x7f) * 500000);
 463                         p = iwe_stream_add_value(info, current_ev, p,
 464                                         end_buf, &iwe, IW_EV_PARAM_LEN);
 465                 }
 466                 current_ev = p;
 467         }
 468
 469         buf = kmalloc(30, GFP_ATOMIC);
 470         if (buf) {
 471                 memset(&iwe, 0, sizeof(iwe));
 472                 iwe.cmd = IWEVCUSTOM;
 473                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp));
 474                 iwe.u.data.length = strlen(buf);
 475                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 476                                                   &iwe, buf);
 477                 memset(&iwe, 0, sizeof(iwe));
 478                 iwe.cmd = IWEVCUSTOM;
 479                 sprintf(buf, " Last beacon: %dms ago",
 480                         jiffies_to_msecs(jiffies - bss->last_update));
 481                 iwe.u.data.length = strlen(buf);
 482                 current_ev = iwe_stream_add_point(info, current_ev,
 483                                                   end_buf, &iwe, buf);
 484                 kfree(buf);
 485         }
 486
 487         if (bss_mesh_cfg(bss)) {
 488                 u8 *cfg = bss_mesh_cfg(bss);
 489                 buf = kmalloc(50, GFP_ATOMIC);
 490                 if (buf) {
 491                         memset(&iwe, 0, sizeof(iwe));
 492                         iwe.cmd = IWEVCUSTOM;
 493                         sprintf(buf, "Mesh network (version %d)", cfg[0]);
 494                         iwe.u.data.length = strlen(buf);
 495                         current_ev = iwe_stream_add_point(info, current_ev,
 496                                                           end_buf,
 497                                                           &iwe, buf);
 498                         sprintf(buf, "Path Selection Protocol ID: "
 499                                 "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
 500                                                         cfg[4]);
 501                         iwe.u.data.length = strlen(buf);
 502                         current_ev = iwe_stream_add_point(info, current_ev,
 503                                                           end_buf,
 504                                                           &iwe, buf);
 505                         sprintf(buf, "Path Selection Metric ID: "
 506                                 "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
 507                                                         cfg[8]);
 508                         iwe.u.data.length = strlen(buf);
 509                         current_ev = iwe_stream_add_point(info, current_ev,
 510                                                           end_buf,
 511                                                           &iwe, buf);
 512                         sprintf(buf, "Congestion Control Mode ID: "
 513                                 "0x%02X%02X%02X%02X", cfg[9], cfg[10],
 514                                                         cfg[11], cfg[12]);
 515                         iwe.u.data.length = strlen(buf);
 516                         current_ev = iwe_stream_add_point(info, current_ev,
 517                                                           end_buf,
 518                                                           &iwe, buf);
 519                         sprintf(buf, "Channel Precedence: "
 520                                 "0x%02X%02X%02X%02X", cfg[13], cfg[14],
 521                                                         cfg[15], cfg[16]);
 522                         iwe.u.data.length = strlen(buf);
 523                         current_ev = iwe_stream_add_point(info, current_ev,
 524                                                           end_buf,
 525                                                           &iwe, buf);
 526                         kfree(buf);
 527                 }
 528         }
 529
 530         return current_ev;
 531 }
 532
 533
 534 int ieee80211_sta_scan_results(struct ieee80211_local *local,
 535                                struct iw_request_info *info,
 536                                char *buf, size_t len)
 537 {
 538         char *current_ev = buf;
 539         char *end_buf = buf + len;
 540         struct ieee80211_sta_bss *bss;
 541
 542         spin_lock_bh(&local->sta_bss_lock);
 543         list_for_each_entry(bss, &local->sta_bss_list, list) {
 544                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
 545                         spin_unlock_bh(&local->sta_bss_lock);
 546                         return -E2BIG;
 547                 }
 548                 current_ev = ieee80211_sta_scan_result(local, info, bss,
 549                                                        current_ev, end_buf);
 550         }
 551         spin_unlock_bh(&local->sta_bss_lock);
 552         return current_ev - buf;
 553 }