git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/libertas/scan.c

   1 /**
   2   * Functions implementing wlan scan IOCTL and firmware command APIs
   3   *
   4   * IOCTL handlers as well as command preperation and response routines
   5   *  for sending scan commands to the firmware.
   6   */
   7 #include <linux/etherdevice.h>
   8 #include <asm/unaligned.h>
   9
  10 #include "host.h"
  11 #include "decl.h"
  12 #include "dev.h"
  13 #include "scan.h"
  14 #include "cmd.h"
  15
  16 //! Approximate amount of data needed to pass a scan result back to iwlist
  17 #define MAX_SCAN_CELL_SIZE  (IW_EV_ADDR_LEN             \
  18                              + IW_ESSID_MAX_SIZE        \
  19                              + IW_EV_UINT_LEN           \
  20                              + IW_EV_FREQ_LEN           \
  21                              + IW_EV_QUAL_LEN           \
  22                              + IW_ESSID_MAX_SIZE        \
  23                              + IW_EV_PARAM_LEN          \
  24                              + 40)      /* 40 for WPAIE */
  25
  26 //! Memory needed to store a max sized channel List TLV for a firmware scan
  27 #define CHAN_TLV_MAX_SIZE  (sizeof(struct mrvlietypesheader)    \
  28                             + (MRVDRV_MAX_CHANNELS_PER_SCAN     \
  29                                * sizeof(struct chanscanparamset)))
  30
  31 //! Memory needed to store a max number/size SSID TLV for a firmware scan
  32 #define SSID_TLV_MAX_SIZE  (1 * sizeof(struct mrvlietypes_ssidparamset))
  33
  34 //! Maximum memory needed for a cmd_ds_802_11_scan with all TLVs at max
  35 #define MAX_SCAN_CFG_ALLOC (sizeof(struct cmd_ds_802_11_scan)   \
  36                             + CHAN_TLV_MAX_SIZE + SSID_TLV_MAX_SIZE)
  37
  38 //! The maximum number of channels the firmware can scan per command
  39 #define MRVDRV_MAX_CHANNELS_PER_SCAN   14
  40
  41 /**
  42  * @brief Number of channels to scan per firmware scan command issuance.
  43  *
  44  *  Number restricted to prevent hitting the limit on the amount of scan data
  45  *  returned in a single firmware scan command.
  46  */
  47 #define MRVDRV_CHANNELS_PER_SCAN_CMD   4
  48
  49 //! Scan time specified in the channel TLV for each channel for passive scans
  50 #define MRVDRV_PASSIVE_SCAN_CHAN_TIME  100
  51
  52 //! Scan time specified in the channel TLV for each channel for active scans
  53 #define MRVDRV_ACTIVE_SCAN_CHAN_TIME   100
  54
  55 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
  56                               struct cmd_header *resp);
  57
  58 /*********************************************************************/
  59 /*                                                                   */
  60 /*  Misc helper functions                                            */
  61 /*                                                                   */
  62 /*********************************************************************/
  63
  64 /**
  65  *  @brief Unsets the MSB on basic rates
  66  *
  67  * Scan through an array and unset the MSB for basic data rates.
  68  *
  69  *  @param rates     buffer of data rates
  70  *  @param len       size of buffer
  71  */
  72 static void lbs_unset_basic_rate_flags(u8 *rates, size_t len)
  73 {
  74         int i;
  75
  76         for (i = 0; i < len; i++)
  77                 rates[i] &= 0x7f;
  78 }
  79
  80
  81 static inline void clear_bss_descriptor(struct bss_descriptor *bss)
  82 {
  83         /* Don't blow away ->list, just BSS data */
  84         memset(bss, 0, offsetof(struct bss_descriptor, list));
  85 }
  86
  87 /**
  88  *  @brief Compare two SSIDs
  89  *
  90  *  @param ssid1    A pointer to ssid to compare
  91  *  @param ssid2    A pointer to ssid to compare
  92  *
  93  *  @return         0: ssid is same, otherwise is different
  94  */
  95 int lbs_ssid_cmp(uint8_t *ssid1, uint8_t ssid1_len, uint8_t *ssid2,
  96                  uint8_t ssid2_len)
  97 {
  98         if (ssid1_len != ssid2_len)
  99                 return -1;
 100
 101         return memcmp(ssid1, ssid2, ssid1_len);
 102 }
 103
 104 static inline int is_same_network(struct bss_descriptor *src,
 105                                   struct bss_descriptor *dst)
 106 {
 107         /* A network is only a duplicate if the channel, BSSID, and ESSID
 108          * all match.  We treat all <hidden> with the same BSSID and channel
 109          * as one network */
 110         return ((src->ssid_len == dst->ssid_len) &&
 111                 (src->channel == dst->channel) &&
 112                 !compare_ether_addr(src->bssid, dst->bssid) &&
 113                 !memcmp(src->ssid, dst->ssid, src->ssid_len));
 114 }
 115
 116
 117
 118
 119 /*********************************************************************/
 120 /*                                                                   */
 121 /*  Main scanning support                                            */
 122 /*                                                                   */
 123 /*********************************************************************/
 124
 125 /**
 126  *  @brief Create a channel list for the driver to scan based on region info
 127  *
 128  *  Only used from lbs_scan_setup_scan_config()
 129  *
 130  *  Use the driver region/band information to construct a comprehensive list
 131  *    of channels to scan.  This routine is used for any scan that is not
 132  *    provided a specific channel list to scan.
 133  *
 134  *  @param priv          A pointer to struct lbs_private structure
 135  *  @param scanchanlist  Output parameter: resulting channel list to scan
 136  *
 137  *  @return              void
 138  */
 139 static int lbs_scan_create_channel_list(struct lbs_private *priv,
 140                                         struct chanscanparamset *scanchanlist)
 141 {
 142         struct region_channel *scanregion;
 143         struct chan_freq_power *cfp;
 144         int rgnidx;
 145         int chanidx;
 146         int nextchan;
 147         uint8_t scantype;
 148
 149         chanidx = 0;
 150
 151         /* Set the default scan type to the user specified type, will later
 152          *   be changed to passive on a per channel basis if restricted by
 153          *   regulatory requirements (11d or 11h)
 154          */
 155         scantype = CMD_SCAN_TYPE_ACTIVE;
 156
 157         for (rgnidx = 0; rgnidx < ARRAY_SIZE(priv->region_channel); rgnidx++) {
 158                 if (priv->enable11d && (priv->connect_status != LBS_CONNECTED)
 159                     && (priv->mesh_connect_status != LBS_CONNECTED)) {
 160                         /* Scan all the supported chan for the first scan */
 161                         if (!priv->universal_channel[rgnidx].valid)
 162                                 continue;
 163                         scanregion = &priv->universal_channel[rgnidx];
 164
 165                         /* clear the parsed_region_chan for the first scan */
 166                         memset(&priv->parsed_region_chan, 0x00,
 167                                sizeof(priv->parsed_region_chan));
 168                 } else {
 169                         if (!priv->region_channel[rgnidx].valid)
 170                                 continue;
 171                         scanregion = &priv->region_channel[rgnidx];
 172                 }
 173
 174                 for (nextchan = 0; nextchan < scanregion->nrcfp; nextchan++, chanidx++) {
 175                         struct chanscanparamset *chan = &scanchanlist[chanidx];
 176
 177                         cfp = scanregion->CFP + nextchan;
 178
 179                         if (priv->enable11d)
 180                                 scantype = lbs_get_scan_type_11d(cfp->channel,
 181                                                                  &priv->parsed_region_chan);
 182
 183                         if (scanregion->band == BAND_B || scanregion->band == BAND_G)
 184                                 chan->radiotype = CMD_SCAN_RADIO_TYPE_BG;
 185
 186                         if (scantype == CMD_SCAN_TYPE_PASSIVE) {
 187                                 chan->maxscantime = cpu_to_le16(MRVDRV_PASSIVE_SCAN_CHAN_TIME);
 188                                 chan->chanscanmode.passivescan = 1;
 189                         } else {
 190                                 chan->maxscantime = cpu_to_le16(MRVDRV_ACTIVE_SCAN_CHAN_TIME);
 191                                 chan->chanscanmode.passivescan = 0;
 192                         }
 193
 194                         chan->channumber = cfp->channel;
 195                 }
 196         }
 197         return chanidx;
 198 }
 199
 200 /*
 201  * Add SSID TLV of the form:
 202  *
 203  * TLV-ID SSID     00 00
 204  * length          06 00
 205  * ssid            4d 4e 54 45 53 54
 206  */
 207 static int lbs_scan_add_ssid_tlv(struct lbs_private *priv, u8 *tlv)
 208 {
 209         struct mrvlietypes_ssidparamset *ssid_tlv = (void *)tlv;
 210
 211         ssid_tlv->header.type = cpu_to_le16(TLV_TYPE_SSID);
 212         ssid_tlv->header.len = cpu_to_le16(priv->scan_ssid_len);
 213         memcpy(ssid_tlv->ssid, priv->scan_ssid, priv->scan_ssid_len);
 214         return sizeof(ssid_tlv->header) + priv->scan_ssid_len;
 215 }
 216
 217 /*
 218  * Add CHANLIST TLV of the form
 219  *
 220  * TLV-ID CHANLIST 01 01
 221  * length          5b 00
 222  * channel 1       00 01 00 00 00 64 00
 223  *   radio type    00
 224  *   channel          01
 225  *   scan type           00
 226  *   min scan time          00 00
 227  *   max scan time                64 00
 228  * channel 2       00 02 00 00 00 64 00
 229  * channel 3       00 03 00 00 00 64 00
 230  * channel 4       00 04 00 00 00 64 00
 231  * channel 5       00 05 00 00 00 64 00
 232  * channel 6       00 06 00 00 00 64 00
 233  * channel 7       00 07 00 00 00 64 00
 234  * channel 8       00 08 00 00 00 64 00
 235  * channel 9       00 09 00 00 00 64 00
 236  * channel 10      00 0a 00 00 00 64 00
 237  * channel 11      00 0b 00 00 00 64 00
 238  * channel 12      00 0c 00 00 00 64 00
 239  * channel 13      00 0d 00 00 00 64 00
 240  *
 241  */
 242 static int lbs_scan_add_chanlist_tlv(uint8_t *tlv,
 243                                      struct chanscanparamset *chan_list,
 244                                      int chan_count)
 245 {
 246         size_t size = sizeof(struct chanscanparamset) *chan_count;
 247         struct mrvlietypes_chanlistparamset *chan_tlv = (void *)tlv;
 248
 249         chan_tlv->header.type = cpu_to_le16(TLV_TYPE_CHANLIST);
 250         memcpy(chan_tlv->chanscanparam, chan_list, size);
 251         chan_tlv->header.len = cpu_to_le16(size);
 252         return sizeof(chan_tlv->header) + size;
 253 }
 254
 255 /*
 256  * Add RATES TLV of the form
 257  *
 258  * TLV-ID RATES    01 00
 259  * length          0e 00
 260  * rates           82 84 8b 96 0c 12 18 24 30 48 60 6c
 261  *
 262  * The rates are in lbs_bg_rates[], but for the 802.11b
 263  * rates the high bit isn't set.
 264  */
 265 static int lbs_scan_add_rates_tlv(uint8_t *tlv)
 266 {
 267         int i;
 268         struct mrvlietypes_ratesparamset *rate_tlv = (void *)tlv;
 269
 270         rate_tlv->header.type = cpu_to_le16(TLV_TYPE_RATES);
 271         tlv += sizeof(rate_tlv->header);
 272         for (i = 0; i < MAX_RATES; i++) {
 273                 *tlv = lbs_bg_rates[i];
 274                 if (*tlv == 0)
 275                         break;
 276                 /* This code makes sure that the 802.11b rates (1 MBit/s, 2
 277                    MBit/s, 5.5 MBit/s and 11 MBit/s get's the high bit set.
 278                    Note that the values are MBit/s * 2, to mark them as
 279                    basic rates so that the firmware likes it better */
 280                 if (*tlv == 0x02 || *tlv == 0x04 ||
 281                     *tlv == 0x0b || *tlv == 0x16)
 282                         *tlv |= 0x80;
 283                 tlv++;
 284         }
 285         rate_tlv->header.len = cpu_to_le16(i);
 286         return sizeof(rate_tlv->header) + i;
 287 }
 288
 289 /*
 290  * Generate the CMD_802_11_SCAN command with the proper tlv
 291  * for a bunch of channels.
 292  */
 293 static int lbs_do_scan(struct lbs_private *priv, uint8_t bsstype,
 294                        struct chanscanparamset *chan_list, int chan_count)
 295 {
 296         int ret = -ENOMEM;
 297         struct cmd_ds_802_11_scan *scan_cmd;
 298         uint8_t *tlv;   /* pointer into our current, growing TLV storage area */
 299
 300         lbs_deb_enter_args(LBS_DEB_SCAN, "bsstype %d, chanlist[].chan %d, chan_count %d",
 301                 bsstype, chan_list ? chan_list[0].channumber : -1,
 302                 chan_count);
 303
 304         /* create the fixed part for scan command */
 305         scan_cmd = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL);
 306         if (scan_cmd == NULL)
 307                 goto out;
 308
 309         tlv = scan_cmd->tlvbuffer;
 310         /* TODO: do we need to scan for a specific BSSID?
 311         memcpy(scan_cmd->bssid, priv->scan_bssid, ETH_ALEN); */
 312         scan_cmd->bsstype = bsstype;
 313
 314         /* add TLVs */
 315         if (priv->scan_ssid_len)
 316                 tlv += lbs_scan_add_ssid_tlv(priv, tlv);
 317         if (chan_list && chan_count)
 318                 tlv += lbs_scan_add_chanlist_tlv(tlv, chan_list, chan_count);
 319         tlv += lbs_scan_add_rates_tlv(tlv);
 320
 321         /* This is the final data we are about to send */
 322         scan_cmd->hdr.size = cpu_to_le16(tlv - (uint8_t *)scan_cmd);
 323         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_CMD", (void *)scan_cmd,
 324                     sizeof(*scan_cmd));
 325         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_TLV", scan_cmd->tlvbuffer,
 326                     tlv - scan_cmd->tlvbuffer);
 327
 328         ret = __lbs_cmd(priv, CMD_802_11_SCAN, &scan_cmd->hdr,
 329                         le16_to_cpu(scan_cmd->hdr.size),
 330                         lbs_ret_80211_scan, 0);
 331
 332 out:
 333         kfree(scan_cmd);
 334         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 335         return ret;
 336 }
 337
 338 /**
 339  *  @brief Internal function used to start a scan based on an input config
 340  *
 341  *  Use the input user scan configuration information when provided in
 342  *    order to send the appropriate scan commands to firmware to populate or
 343  *    update the internal driver scan table
 344  *
 345  *  @param priv          A pointer to struct lbs_private structure
 346  *  @param full_scan     Do a full-scan (blocking)
 347  *
 348  *  @return              0 or < 0 if error
 349  */
 350 int lbs_scan_networks(struct lbs_private *priv, int full_scan)
 351 {
 352         int ret = -ENOMEM;
 353         struct chanscanparamset *chan_list;
 354         struct chanscanparamset *curr_chans;
 355         int chan_count;
 356         uint8_t bsstype = CMD_BSS_TYPE_ANY;
 357         int numchannels = MRVDRV_CHANNELS_PER_SCAN_CMD;
 358         union iwreq_data wrqu;
 359 #ifdef CONFIG_LIBERTAS_DEBUG
 360         struct bss_descriptor *iter;
 361         int i = 0;
 362         DECLARE_MAC_BUF(mac);
 363 #endif
 364
 365         lbs_deb_enter_args(LBS_DEB_SCAN, "full_scan %d", full_scan);
 366
 367         /* Cancel any partial outstanding partial scans if this scan
 368          * is a full scan.
 369          */
 370         if (full_scan && delayed_work_pending(&priv->scan_work))
 371                 cancel_delayed_work(&priv->scan_work);
 372
 373         /* User-specified bsstype or channel list
 374         TODO: this can be implemented if some user-space application
 375         need the feature. Formerly, it was accessible from debugfs,
 376         but then nowhere used.
 377         if (user_cfg) {
 378                 if (user_cfg->bsstype)
 379                 bsstype = user_cfg->bsstype;
 380         } */
 381
 382         lbs_deb_scan("numchannels %d, bsstype %d\n", numchannels, bsstype);
 383
 384         /* Create list of channels to scan */
 385         chan_list = kzalloc(sizeof(struct chanscanparamset) *
 386                             LBS_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL);
 387         if (!chan_list) {
 388                 lbs_pr_alert("SCAN: chan_list empty\n");
 389                 goto out;
 390         }
 391
 392         /* We want to scan all channels */
 393         chan_count = lbs_scan_create_channel_list(priv, chan_list);
 394
 395         netif_stop_queue(priv->dev);
 396         netif_carrier_off(priv->dev);
 397         if (priv->mesh_dev) {
 398                 netif_stop_queue(priv->mesh_dev);
 399                 netif_carrier_off(priv->mesh_dev);
 400         }
 401
 402         /* Prepare to continue an interrupted scan */
 403         lbs_deb_scan("chan_count %d, scan_channel %d\n",
 404                      chan_count, priv->scan_channel);
 405         curr_chans = chan_list;
 406         /* advance channel list by already-scanned-channels */
 407         if (priv->scan_channel > 0) {
 408                 curr_chans += priv->scan_channel;
 409                 chan_count -= priv->scan_channel;
 410         }
 411
 412         /* Send scan command(s)
 413          * numchannels contains the number of channels we should maximally scan
 414          * chan_count is the total number of channels to scan
 415          */
 416
 417         while (chan_count) {
 418                 int to_scan = min(numchannels, chan_count);
 419                 lbs_deb_scan("scanning %d of %d channels\n",
 420                              to_scan, chan_count);
 421                 ret = lbs_do_scan(priv, bsstype, curr_chans,
 422                                   to_scan);
 423                 if (ret) {
 424                         lbs_pr_err("SCAN_CMD failed\n");
 425                         goto out2;
 426                 }
 427                 curr_chans += to_scan;
 428                 chan_count -= to_scan;
 429
 430                 /* somehow schedule the next part of the scan */
 431                 if (chan_count && !full_scan &&
 432                     !priv->surpriseremoved) {
 433                         /* -1 marks just that we're currently scanning */
 434                         if (priv->scan_channel < 0)
 435                                 priv->scan_channel = to_scan;
 436                         else
 437                                 priv->scan_channel += to_scan;
 438                         cancel_delayed_work(&priv->scan_work);
 439                         queue_delayed_work(priv->work_thread, &priv->scan_work,
 440                                            msecs_to_jiffies(300));
 441                         /* skip over GIWSCAN event */
 442                         goto out;
 443                 }
 444
 445         }
 446         memset(&wrqu, 0, sizeof(union iwreq_data));
 447         wireless_send_event(priv->dev, SIOCGIWSCAN, &wrqu, NULL);
 448
 449 #ifdef CONFIG_LIBERTAS_DEBUG
 450         /* Dump the scan table */
 451         mutex_lock(&priv->lock);
 452         lbs_deb_scan("scan table:\n");
 453         list_for_each_entry(iter, &priv->network_list, list)
 454                 lbs_deb_scan("%02d: BSSID %s, RSSI %d, SSID '%s'\n",
 455                              i++, print_mac(mac, iter->bssid), iter->rssi,
 456                              escape_essid(iter->ssid, iter->ssid_len));
 457         mutex_unlock(&priv->lock);
 458 #endif
 459
 460 out2:
 461         priv->scan_channel = 0;
 462
 463 out:
 464         if (priv->connect_status == LBS_CONNECTED) {
 465                 netif_carrier_on(priv->dev);
 466                 if (!priv->tx_pending_len)
 467                         netif_wake_queue(priv->dev);
 468         }
 469         if (priv->mesh_dev && (priv->mesh_connect_status == LBS_CONNECTED)) {
 470                 netif_carrier_on(priv->mesh_dev);
 471                 if (!priv->tx_pending_len)
 472                         netif_wake_queue(priv->mesh_dev);
 473         }
 474         kfree(chan_list);
 475
 476         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 477         return ret;
 478 }
 479
 480 void lbs_scan_worker(struct work_struct *work)
 481 {
 482         struct lbs_private *priv =
 483                 container_of(work, struct lbs_private, scan_work.work);
 484
 485         lbs_deb_enter(LBS_DEB_SCAN);
 486         lbs_scan_networks(priv, 0);
 487         lbs_deb_leave(LBS_DEB_SCAN);
 488 }
 489
 490
 491 /*********************************************************************/
 492 /*                                                                   */
 493 /*  Result interpretation                                            */
 494 /*                                                                   */
 495 /*********************************************************************/
 496
 497 /**
 498  *  @brief Interpret a BSS scan response returned from the firmware
 499  *
 500  *  Parse the various fixed fields and IEs passed back for a a BSS probe
 501  *  response or beacon from the scan command.  Record information as needed
 502  *  in the scan table struct bss_descriptor for that entry.
 503  *
 504  *  @param bss  Output parameter: Pointer to the BSS Entry
 505  *
 506  *  @return             0 or -1
 507  */
 508 static int lbs_process_bss(struct bss_descriptor *bss,
 509                            uint8_t **pbeaconinfo, int *bytesleft)
 510 {
 511         struct ieeetypes_fhparamset *pFH;
 512         struct ieeetypes_dsparamset *pDS;
 513         struct ieeetypes_cfparamset *pCF;
 514         struct ieeetypes_ibssparamset *pibss;
 515         DECLARE_MAC_BUF(mac);
 516         struct ieeetypes_countryinfoset *pcountryinfo;
 517         uint8_t *pos, *end, *p;
 518         uint8_t n_ex_rates = 0, got_basic_rates = 0, n_basic_rates = 0;
 519         uint16_t beaconsize = 0;
 520         int ret;
 521
 522         lbs_deb_enter(LBS_DEB_SCAN);
 523
 524         if (*bytesleft >= sizeof(beaconsize)) {
 525                 /* Extract & convert beacon size from the command buffer */
 526                 beaconsize = get_unaligned_le16(*pbeaconinfo);
 527                 *bytesleft -= sizeof(beaconsize);
 528                 *pbeaconinfo += sizeof(beaconsize);
 529         }
 530
 531         if (beaconsize == 0 || beaconsize > *bytesleft) {
 532                 *pbeaconinfo += *bytesleft;
 533                 *bytesleft = 0;
 534                 ret = -1;
 535                 goto done;
 536         }
 537
 538         /* Initialize the current working beacon pointer for this BSS iteration */
 539         pos = *pbeaconinfo;
 540         end = pos + beaconsize;
 541
 542         /* Advance the return beacon pointer past the current beacon */
 543         *pbeaconinfo += beaconsize;
 544         *bytesleft -= beaconsize;
 545
 546         memcpy(bss->bssid, pos, ETH_ALEN);
 547         lbs_deb_scan("process_bss: BSSID %s\n", print_mac(mac, bss->bssid));
 548         pos += ETH_ALEN;
 549
 550         if ((end - pos) < 12) {
 551                 lbs_deb_scan("process_bss: Not enough bytes left\n");
 552                 ret = -1;
 553                 goto done;
 554         }
 555
 556         /*
 557          * next 4 fields are RSSI, time stamp, beacon interval,
 558          *   and capability information
 559          */
 560
 561         /* RSSI is 1 byte long */
 562         bss->rssi = *pos;
 563         lbs_deb_scan("process_bss: RSSI %d\n", *pos);
 564         pos++;
 565
 566         /* time stamp is 8 bytes long */
 567         pos += 8;
 568
 569         /* beacon interval is 2 bytes long */
 570         bss->beaconperiod = get_unaligned_le16(pos);
 571         pos += 2;
 572
 573         /* capability information is 2 bytes long */
 574         bss->capability = get_unaligned_le16(pos);
 575         lbs_deb_scan("process_bss: capabilities 0x%04x\n", bss->capability);
 576         pos += 2;
 577
 578         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 579                 lbs_deb_scan("process_bss: WEP enabled\n");
 580         if (bss->capability & WLAN_CAPABILITY_IBSS)
 581                 bss->mode = IW_MODE_ADHOC;
 582         else
 583                 bss->mode = IW_MODE_INFRA;
 584
 585         /* rest of the current buffer are IE's */
 586         lbs_deb_scan("process_bss: IE len %zd\n", end - pos);
 587         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: IE info", pos, end - pos);
 588
 589         /* process variable IE */
 590         while (pos <= end - 2) {
 591                 struct ieee80211_info_element * elem = (void *)pos;
 592
 593                 if (pos + elem->len > end) {
 594                         lbs_deb_scan("process_bss: error in processing IE, "
 595                                      "bytes left < IE length\n");
 596                         break;
 597                 }
 598
 599                 switch (elem->id) {
 600                 case MFIE_TYPE_SSID:
 601                         bss->ssid_len = elem->len;
 602                         memcpy(bss->ssid, elem->data, elem->len);
 603                         lbs_deb_scan("got SSID IE: '%s', len %u\n",
 604                                      escape_essid(bss->ssid, bss->ssid_len),
 605                                      bss->ssid_len);
 606                         break;
 607
 608                 case MFIE_TYPE_RATES:
 609                         n_basic_rates = min_t(uint8_t, MAX_RATES, elem->len);
 610                         memcpy(bss->rates, elem->data, n_basic_rates);
 611                         got_basic_rates = 1;
 612                         lbs_deb_scan("got RATES IE\n");
 613                         break;
 614
 615                 case MFIE_TYPE_FH_SET:
 616                         pFH = (struct ieeetypes_fhparamset *) pos;
 617                         memmove(&bss->phyparamset.fhparamset, pFH,
 618                                 sizeof(struct ieeetypes_fhparamset));
 619                         lbs_deb_scan("got FH IE\n");
 620                         break;
 621
 622                 case MFIE_TYPE_DS_SET:
 623                         pDS = (struct ieeetypes_dsparamset *) pos;
 624                         bss->channel = pDS->currentchan;
 625                         memcpy(&bss->phyparamset.dsparamset, pDS,
 626                                sizeof(struct ieeetypes_dsparamset));
 627                         lbs_deb_scan("got DS IE, channel %d\n", bss->channel);
 628                         break;
 629
 630                 case MFIE_TYPE_CF_SET:
 631                         pCF = (struct ieeetypes_cfparamset *) pos;
 632                         memcpy(&bss->ssparamset.cfparamset, pCF,
 633                                sizeof(struct ieeetypes_cfparamset));
 634                         lbs_deb_scan("got CF IE\n");
 635                         break;
 636
 637                 case MFIE_TYPE_IBSS_SET:
 638                         pibss = (struct ieeetypes_ibssparamset *) pos;
 639                         bss->atimwindow = le16_to_cpu(pibss->atimwindow);
 640                         memmove(&bss->ssparamset.ibssparamset, pibss,
 641                                 sizeof(struct ieeetypes_ibssparamset));
 642                         lbs_deb_scan("got IBSS IE\n");
 643                         break;
 644
 645                 case MFIE_TYPE_COUNTRY:
 646                         pcountryinfo = (struct ieeetypes_countryinfoset *) pos;
 647                         lbs_deb_scan("got COUNTRY IE\n");
 648                         if (pcountryinfo->len < sizeof(pcountryinfo->countrycode)
 649                             || pcountryinfo->len > 254) {
 650                                 lbs_deb_scan("process_bss: 11D- Err CountryInfo len %d, min %zd, max 254\n",
 651                                              pcountryinfo->len, sizeof(pcountryinfo->countrycode));
 652                                 ret = -1;
 653                                 goto done;
 654                         }
 655
 656                         memcpy(&bss->countryinfo, pcountryinfo, pcountryinfo->len + 2);
 657                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: 11d countryinfo",
 658                                     (uint8_t *) pcountryinfo,
 659                                     (int) (pcountryinfo->len + 2));
 660                         break;
 661
 662                 case MFIE_TYPE_RATES_EX:
 663                         /* only process extended supported rate if data rate is
 664                          * already found. Data rate IE should come before
 665                          * extended supported rate IE
 666                          */
 667                         lbs_deb_scan("got RATESEX IE\n");
 668                         if (!got_basic_rates) {
 669                                 lbs_deb_scan("... but ignoring it\n");
 670                                 break;
 671                         }
 672
 673                         n_ex_rates = elem->len;
 674                         if (n_basic_rates + n_ex_rates > MAX_RATES)
 675                                 n_ex_rates = MAX_RATES - n_basic_rates;
 676
 677                         p = bss->rates + n_basic_rates;
 678                         memcpy(p, elem->data, n_ex_rates);
 679                         break;
 680
 681                 case MFIE_TYPE_GENERIC:
 682                         if (elem->len >= 4 &&
 683                             elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 684                             elem->data[2] == 0xf2 && elem->data[3] == 0x01) {
 685                                 bss->wpa_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 686                                 memcpy(bss->wpa_ie, elem, bss->wpa_ie_len);
 687                                 lbs_deb_scan("got WPA IE\n");
 688                                 lbs_deb_hex(LBS_DEB_SCAN, "WPA IE", bss->wpa_ie, elem->len);
 689                         } else if (elem->len >= MARVELL_MESH_IE_LENGTH &&
 690                                    elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 691                                    elem->data[2] == 0x43 && elem->data[3] == 0x04) {
 692                                 lbs_deb_scan("got mesh IE\n");
 693                                 bss->mesh = 1;
 694                         } else {
 695                                 lbs_deb_scan("got generic IE: %02x:%02x:%02x:%02x, len %d\n",
 696                                         elem->data[0], elem->data[1],
 697                                         elem->data[2], elem->data[3],
 698                                         elem->len);
 699                         }
 700                         break;
 701
 702                 case MFIE_TYPE_RSN:
 703                         lbs_deb_scan("got RSN IE\n");
 704                         bss->rsn_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 705                         memcpy(bss->rsn_ie, elem, bss->rsn_ie_len);
 706                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: RSN_IE",
 707                                     bss->rsn_ie, elem->len);
 708                         break;
 709
 710                 default:
 711                         lbs_deb_scan("got IE 0x%04x, len %d\n",
 712                                      elem->id, elem->len);
 713                         break;
 714                 }
 715
 716                 pos += elem->len + 2;
 717         }
 718
 719         /* Timestamp */
 720         bss->last_scanned = jiffies;
 721         lbs_unset_basic_rate_flags(bss->rates, sizeof(bss->rates));
 722
 723         ret = 0;
 724
 725 done:
 726         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 727         return ret;
 728 }
 729
 730 /**
 731  *  @brief Send a scan command for all available channels filtered on a spec
 732  *
 733  *  Used in association code and from debugfs
 734  *
 735  *  @param priv             A pointer to struct lbs_private structure
 736  *  @param ssid             A pointer to the SSID to scan for
 737  *  @param ssid_len         Length of the SSID
 738  *
 739  *  @return                0-success, otherwise fail
 740  */
 741 int lbs_send_specific_ssid_scan(struct lbs_private *priv, uint8_t *ssid,
 742                                 uint8_t ssid_len)
 743 {
 744         int ret = 0;
 745
 746         lbs_deb_enter_args(LBS_DEB_SCAN, "SSID '%s'\n",
 747                            escape_essid(ssid, ssid_len));
 748
 749         if (!ssid_len)
 750                 goto out;
 751
 752         memcpy(priv->scan_ssid, ssid, ssid_len);
 753         priv->scan_ssid_len = ssid_len;
 754
 755         lbs_scan_networks(priv, 1);
 756         if (priv->surpriseremoved) {
 757                 ret = -1;
 758                 goto out;
 759         }
 760
 761 out:
 762         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 763         return ret;
 764 }
 765
 766
 767
 768
 769 /*********************************************************************/
 770 /*                                                                   */
 771 /*  Support for Wireless Extensions                                  */
 772 /*                                                                   */
 773 /*********************************************************************/
 774
 775
 776 #define MAX_CUSTOM_LEN 64
 777
 778 static inline char *lbs_translate_scan(struct lbs_private *priv,
 779                                        char *start, char *stop,
 780                                        struct bss_descriptor *bss)
 781 {
 782         struct chan_freq_power *cfp;
 783         char *current_val;      /* For rates */
 784         struct iw_event iwe;    /* Temporary buffer */
 785         int j;
 786 #define PERFECT_RSSI ((uint8_t)50)
 787 #define WORST_RSSI   ((uint8_t)0)
 788 #define RSSI_DIFF    ((uint8_t)(PERFECT_RSSI - WORST_RSSI))
 789         uint8_t rssi;
 790
 791         lbs_deb_enter(LBS_DEB_SCAN);
 792
 793         cfp = lbs_find_cfp_by_band_and_channel(priv, 0, bss->channel);
 794         if (!cfp) {
 795                 lbs_deb_scan("Invalid channel number %d\n", bss->channel);
 796                 start = NULL;
 797                 goto out;
 798         }
 799
 800         /* First entry *MUST* be the BSSID */
 801         iwe.cmd = SIOCGIWAP;
 802         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 803         memcpy(iwe.u.ap_addr.sa_data, &bss->bssid, ETH_ALEN);
 804         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_ADDR_LEN);
 805
 806         /* SSID */
 807         iwe.cmd = SIOCGIWESSID;
 808         iwe.u.data.flags = 1;
 809         iwe.u.data.length = min((uint32_t) bss->ssid_len, (uint32_t) IW_ESSID_MAX_SIZE);
 810         start = iwe_stream_add_point(start, stop, &iwe, bss->ssid);
 811
 812         /* Mode */
 813         iwe.cmd = SIOCGIWMODE;
 814         iwe.u.mode = bss->mode;
 815         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_UINT_LEN);
 816
 817         /* Frequency */
 818         iwe.cmd = SIOCGIWFREQ;
 819         iwe.u.freq.m = (long)cfp->freq * 100000;
 820         iwe.u.freq.e = 1;
 821         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_FREQ_LEN);
 822
 823         /* Add quality statistics */
 824         iwe.cmd = IWEVQUAL;
 825         iwe.u.qual.updated = IW_QUAL_ALL_UPDATED;
 826         iwe.u.qual.level = SCAN_RSSI(bss->rssi);
 827
 828         rssi = iwe.u.qual.level - MRVDRV_NF_DEFAULT_SCAN_VALUE;
 829         iwe.u.qual.qual =
 830                 (100 * RSSI_DIFF * RSSI_DIFF - (PERFECT_RSSI - rssi) *
 831                  (15 * (RSSI_DIFF) + 62 * (PERFECT_RSSI - rssi))) /
 832                 (RSSI_DIFF * RSSI_DIFF);
 833         if (iwe.u.qual.qual > 100)
 834                 iwe.u.qual.qual = 100;
 835
 836         if (priv->NF[TYPE_BEACON][TYPE_NOAVG] == 0) {
 837                 iwe.u.qual.noise = MRVDRV_NF_DEFAULT_SCAN_VALUE;
 838         } else {
 839                 iwe.u.qual.noise = CAL_NF(priv->NF[TYPE_BEACON][TYPE_NOAVG]);
 840         }
 841
 842         /* Locally created ad-hoc BSSs won't have beacons if this is the
 843          * only station in the adhoc network; so get signal strength
 844          * from receive statistics.
 845          */
 846         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate
 847             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 848                              priv->curbssparams.ssid_len,
 849                              bss->ssid, bss->ssid_len)) {
 850                 int snr, nf;
 851                 snr = priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 852                 nf = priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 853                 iwe.u.qual.level = CAL_RSSI(snr, nf);
 854         }
 855         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_QUAL_LEN);
 856
 857         /* Add encryption capability */
 858         iwe.cmd = SIOCGIWENCODE;
 859         if (bss->capability & WLAN_CAPABILITY_PRIVACY) {
 860                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 861         } else {
 862                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 863         }
 864         iwe.u.data.length = 0;
 865         start = iwe_stream_add_point(start, stop, &iwe, bss->ssid);
 866
 867         current_val = start + IW_EV_LCP_LEN;
 868
 869         iwe.cmd = SIOCGIWRATE;
 870         iwe.u.bitrate.fixed = 0;
 871         iwe.u.bitrate.disabled = 0;
 872         iwe.u.bitrate.value = 0;
 873
 874         for (j = 0; bss->rates[j] && (j < sizeof(bss->rates)); j++) {
 875                 /* Bit rate given in 500 kb/s units */
 876                 iwe.u.bitrate.value = bss->rates[j] * 500000;
 877                 current_val = iwe_stream_add_value(start, current_val,
 878                                          stop, &iwe, IW_EV_PARAM_LEN);
 879         }
 880         if ((bss->mode == IW_MODE_ADHOC) && priv->adhoccreate
 881             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 882                              priv->curbssparams.ssid_len,
 883                              bss->ssid, bss->ssid_len)) {
 884                 iwe.u.bitrate.value = 22 * 500000;
 885                 current_val = iwe_stream_add_value(start, current_val,
 886                                                    stop, &iwe, IW_EV_PARAM_LEN);
 887         }
 888         /* Check if we added any event */
 889         if((current_val - start) > IW_EV_LCP_LEN)
 890                 start = current_val;
 891
 892         memset(&iwe, 0, sizeof(iwe));
 893         if (bss->wpa_ie_len) {
 894                 char buf[MAX_WPA_IE_LEN];
 895                 memcpy(buf, bss->wpa_ie, bss->wpa_ie_len);
 896                 iwe.cmd = IWEVGENIE;
 897                 iwe.u.data.length = bss->wpa_ie_len;
 898                 start = iwe_stream_add_point(start, stop, &iwe, buf);
 899         }
 900
 901         memset(&iwe, 0, sizeof(iwe));
 902         if (bss->rsn_ie_len) {
 903                 char buf[MAX_WPA_IE_LEN];
 904                 memcpy(buf, bss->rsn_ie, bss->rsn_ie_len);
 905                 iwe.cmd = IWEVGENIE;
 906                 iwe.u.data.length = bss->rsn_ie_len;
 907                 start = iwe_stream_add_point(start, stop, &iwe, buf);
 908         }
 909
 910         if (bss->mesh) {
 911                 char custom[MAX_CUSTOM_LEN];
 912                 char *p = custom;
 913
 914                 iwe.cmd = IWEVCUSTOM;
 915                 p += snprintf(p, MAX_CUSTOM_LEN, "mesh-type: olpc");
 916                 iwe.u.data.length = p - custom;
 917                 if (iwe.u.data.length)
 918                         start = iwe_stream_add_point(start, stop, &iwe, custom);
 919         }
 920
 921 out:
 922         lbs_deb_leave_args(LBS_DEB_SCAN, "start %p", start);
 923         return start;
 924 }
 925
 926
 927 /**
 928  *  @brief Handle Scan Network ioctl
 929  *
 930  *  @param dev          A pointer to net_device structure
 931  *  @param info         A pointer to iw_request_info structure
 932  *  @param vwrq         A pointer to iw_param structure
 933  *  @param extra        A pointer to extra data buf
 934  *
 935  *  @return             0 --success, otherwise fail
 936  */
 937 int lbs_set_scan(struct net_device *dev, struct iw_request_info *info,
 938                  union iwreq_data *wrqu, char *extra)
 939 {
 940         struct lbs_private *priv = dev->priv;
 941         int ret = 0;
 942
 943         lbs_deb_enter(LBS_DEB_WEXT);
 944
 945         if (!netif_running(dev)) {
 946                 ret = -ENETDOWN;
 947                 goto out;
 948         }
 949
 950         /* mac80211 does this:
 951         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 952         if (sdata->type != IEEE80211_IF_TYPE_xxx) {
 953                 ret = -EOPNOTSUPP;
 954                 goto out;
 955         }
 956         */
 957
 958         if (wrqu->data.length == sizeof(struct iw_scan_req) &&
 959             wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 960                 struct iw_scan_req *req = (struct iw_scan_req *)extra;
 961                 priv->scan_ssid_len = req->essid_len;
 962                 memcpy(priv->scan_ssid, req->essid, priv->scan_ssid_len);
 963                 lbs_deb_wext("set_scan, essid '%s'\n",
 964                         escape_essid(priv->scan_ssid, priv->scan_ssid_len));
 965         } else {
 966                 priv->scan_ssid_len = 0;
 967         }
 968
 969         if (!delayed_work_pending(&priv->scan_work))
 970                 queue_delayed_work(priv->work_thread, &priv->scan_work,
 971                                    msecs_to_jiffies(50));
 972         /* set marker that currently a scan is taking place */
 973         priv->scan_channel = -1;
 974
 975         if (priv->surpriseremoved)
 976                 ret = -EIO;
 977
 978 out:
 979         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", ret);
 980         return ret;
 981 }
 982
 983
 984 /**
 985  *  @brief  Handle Retrieve scan table ioctl
 986  *
 987  *  @param dev          A pointer to net_device structure
 988  *  @param info         A pointer to iw_request_info structure
 989  *  @param dwrq         A pointer to iw_point structure
 990  *  @param extra        A pointer to extra data buf
 991  *
 992  *  @return             0 --success, otherwise fail
 993  */
 994 int lbs_get_scan(struct net_device *dev, struct iw_request_info *info,
 995                  struct iw_point *dwrq, char *extra)
 996 {
 997 #define SCAN_ITEM_SIZE 128
 998         struct lbs_private *priv = dev->priv;
 999         int err = 0;
1000         char *ev = extra;
1001         char *stop = ev + dwrq->length;
1002         struct bss_descriptor *iter_bss;
1003         struct bss_descriptor *safe;
1004
1005         lbs_deb_enter(LBS_DEB_WEXT);
1006
1007         /* iwlist should wait until the current scan is finished */
1008         if (priv->scan_channel)
1009                 return -EAGAIN;
1010
1011         /* Update RSSI if current BSS is a locally created ad-hoc BSS */
1012         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate)
1013                 lbs_prepare_and_send_command(priv, CMD_802_11_RSSI, 0,
1014                                              CMD_OPTION_WAITFORRSP, 0, NULL);
1015
1016         mutex_lock(&priv->lock);
1017         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1018                 char *next_ev;
1019                 unsigned long stale_time;
1020
1021                 if (stop - ev < SCAN_ITEM_SIZE) {
1022                         err = -E2BIG;
1023                         break;
1024                 }
1025
1026                 /* For mesh device, list only mesh networks */
1027                 if (dev == priv->mesh_dev && !iter_bss->mesh)
1028                         continue;
1029
1030                 /* Prune old an old scan result */
1031                 stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1032                 if (time_after(jiffies, stale_time)) {
1033                         list_move_tail(&iter_bss->list, &priv->network_free_list);
1034                         clear_bss_descriptor(iter_bss);
1035                         continue;
1036                 }
1037
1038                 /* Translate to WE format this entry */
1039                 next_ev = lbs_translate_scan(priv, ev, stop, iter_bss);
1040                 if (next_ev == NULL)
1041                         continue;
1042                 ev = next_ev;
1043         }
1044         mutex_unlock(&priv->lock);
1045
1046         dwrq->length = (ev - extra);
1047         dwrq->flags = 0;
1048
1049         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", err);
1050         return err;
1051 }
1052
1053
1054
1055
1056 /*********************************************************************/
1057 /*                                                                   */
1058 /*  Command execution                                                */
1059 /*                                                                   */
1060 /*********************************************************************/
1061
1062
1063 /**
1064  *  @brief This function handles the command response of scan
1065  *
1066  *  Called from handle_cmd_response() in cmdrespc.
1067  *
1068  *   The response buffer for the scan command has the following
1069  *      memory layout:
1070  *
1071  *     .-----------------------------------------------------------.
1072  *     |  header (4 * sizeof(u16)):  Standard command response hdr |
1073  *     .-----------------------------------------------------------.
1074  *     |  bufsize (u16) : sizeof the BSS Description data          |
1075  *     .-----------------------------------------------------------.
1076  *     |  NumOfSet (u8) : Number of BSS Descs returned             |
1077  *     .-----------------------------------------------------------.
1078  *     |  BSSDescription data (variable, size given in bufsize)    |
1079  *     .-----------------------------------------------------------.
1080  *     |  TLV data (variable, size calculated using header->size,  |
1081  *     |            bufsize and sizeof the fixed fields above)     |
1082  *     .-----------------------------------------------------------.
1083  *
1084  *  @param priv    A pointer to struct lbs_private structure
1085  *  @param resp    A pointer to cmd_ds_command
1086  *
1087  *  @return        0 or -1
1088  */
1089 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
1090                               struct cmd_header *resp)
1091 {
1092         struct cmd_ds_802_11_scan_rsp *scanresp = (void *)resp;
1093         struct bss_descriptor *iter_bss;
1094         struct bss_descriptor *safe;
1095         uint8_t *bssinfo;
1096         uint16_t scanrespsize;
1097         int bytesleft;
1098         int idx;
1099         int tlvbufsize;
1100         int ret;
1101
1102         lbs_deb_enter(LBS_DEB_SCAN);
1103
1104         /* Prune old entries from scan table */
1105         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1106                 unsigned long stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1107                 if (time_before(jiffies, stale_time))
1108                         continue;
1109                 list_move_tail (&iter_bss->list, &priv->network_free_list);
1110                 clear_bss_descriptor(iter_bss);
1111         }
1112
1113         if (scanresp->nr_sets > MAX_NETWORK_COUNT) {
1114                 lbs_deb_scan("SCAN_RESP: too many scan results (%d, max %d)\n",
1115                              scanresp->nr_sets, MAX_NETWORK_COUNT);
1116                 ret = -1;
1117                 goto done;
1118         }
1119
1120         bytesleft = le16_to_cpu(scanresp->bssdescriptsize);
1121         lbs_deb_scan("SCAN_RESP: bssdescriptsize %d\n", bytesleft);
1122
1123         scanrespsize = le16_to_cpu(resp->size);
1124         lbs_deb_scan("SCAN_RESP: scan results %d\n", scanresp->nr_sets);
1125
1126         bssinfo = scanresp->bssdesc_and_tlvbuffer;
1127
1128         /* The size of the TLV buffer is equal to the entire command response
1129          *   size (scanrespsize) minus the fixed fields (sizeof()'s), the
1130          *   BSS Descriptions (bssdescriptsize as bytesLef) and the command
1131          *   response header (S_DS_GEN)
1132          */
1133         tlvbufsize = scanrespsize - (bytesleft + sizeof(scanresp->bssdescriptsize)
1134                                      + sizeof(scanresp->nr_sets)
1135                                      + S_DS_GEN);
1136
1137         /*
1138          *  Process each scan response returned (scanresp->nr_sets). Save
1139          *    the information in the newbssentry and then insert into the
1140          *    driver scan table either as an update to an existing entry
1141          *    or as an addition at the end of the table
1142          */
1143         for (idx = 0; idx < scanresp->nr_sets && bytesleft; idx++) {
1144                 struct bss_descriptor new;
1145                 struct bss_descriptor *found = NULL;
1146                 struct bss_descriptor *oldest = NULL;
1147                 DECLARE_MAC_BUF(mac);
1148
1149                 /* Process the data fields and IEs returned for this BSS */
1150                 memset(&new, 0, sizeof (struct bss_descriptor));
1151                 if (lbs_process_bss(&new, &bssinfo, &bytesleft) != 0) {
1152                         /* error parsing the scan response, skipped */
1153                         lbs_deb_scan("SCAN_RESP: process_bss returned ERROR\n");
1154                         continue;
1155                 }
1156
1157                 /* Try to find this bss in the scan table */
1158                 list_for_each_entry (iter_bss, &priv->network_list, list) {
1159                         if (is_same_network(iter_bss, &new)) {
1160                                 found = iter_bss;
1161                                 break;
1162                         }
1163
1164                         if ((oldest == NULL) ||
1165                             (iter_bss->last_scanned < oldest->last_scanned))
1166                                 oldest = iter_bss;
1167                 }
1168
1169                 if (found) {
1170                         /* found, clear it */
1171                         clear_bss_descriptor(found);
1172                 } else if (!list_empty(&priv->network_free_list)) {
1173                         /* Pull one from the free list */
1174                         found = list_entry(priv->network_free_list.next,
1175                                            struct bss_descriptor, list);
1176                         list_move_tail(&found->list, &priv->network_list);
1177                 } else if (oldest) {
1178                         /* If there are no more slots, expire the oldest */
1179                         found = oldest;
1180                         clear_bss_descriptor(found);
1181                         list_move_tail(&found->list, &priv->network_list);
1182                 } else {
1183                         continue;
1184                 }
1185
1186                 lbs_deb_scan("SCAN_RESP: BSSID %s\n", print_mac(mac, new.bssid));
1187
1188                 /* Copy the locally created newbssentry to the scan table */
1189                 memcpy(found, &new, offsetof(struct bss_descriptor, list));
1190         }
1191
1192         ret = 0;
1193
1194 done:
1195         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
1196         return ret;
1197 }