err.no 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[0].channumber, chan_count);
 302
 303         /* create the fixed part for scan command */
 304         scan_cmd = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL);
 305         if (scan_cmd == NULL)
 306                 goto out;
 307
 308         tlv = scan_cmd->tlvbuffer;
 309         /* TODO: do we need to scan for a specific BSSID?
 310         memcpy(scan_cmd->bssid, priv->scan_bssid, ETH_ALEN); */
 311         scan_cmd->bsstype = bsstype;
 312
 313         /* add TLVs */
 314         if (priv->scan_ssid_len)
 315                 tlv += lbs_scan_add_ssid_tlv(priv, tlv);
 316         if (chan_list && chan_count)
 317                 tlv += lbs_scan_add_chanlist_tlv(tlv, chan_list, chan_count);
 318         tlv += lbs_scan_add_rates_tlv(tlv);
 319
 320         /* This is the final data we are about to send */
 321         scan_cmd->hdr.size = cpu_to_le16(tlv - (uint8_t *)scan_cmd);
 322         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_CMD", (void *)scan_cmd,
 323                     sizeof(*scan_cmd));
 324         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_TLV", scan_cmd->tlvbuffer,
 325                     tlv - scan_cmd->tlvbuffer);
 326
 327         ret = __lbs_cmd(priv, CMD_802_11_SCAN, &scan_cmd->hdr,
 328                         le16_to_cpu(scan_cmd->hdr.size),
 329                         lbs_ret_80211_scan, 0);
 330
 331 out:
 332         kfree(scan_cmd);
 333         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 334         return ret;
 335 }
 336
 337 /**
 338  *  @brief Internal function used to start a scan based on an input config
 339  *
 340  *  Use the input user scan configuration information when provided in
 341  *    order to send the appropriate scan commands to firmware to populate or
 342  *    update the internal driver scan table
 343  *
 344  *  @param priv          A pointer to struct lbs_private structure
 345  *  @param full_scan     Do a full-scan (blocking)
 346  *
 347  *  @return              0 or < 0 if error
 348  */
 349 int lbs_scan_networks(struct lbs_private *priv, int full_scan)
 350 {
 351         int ret = -ENOMEM;
 352         struct chanscanparamset *chan_list;
 353         struct chanscanparamset *curr_chans;
 354         int chan_count;
 355         uint8_t bsstype = CMD_BSS_TYPE_ANY;
 356         int numchannels = MRVDRV_CHANNELS_PER_SCAN_CMD;
 357         union iwreq_data wrqu;
 358 #ifdef CONFIG_LIBERTAS_DEBUG
 359         struct bss_descriptor *iter;
 360         int i = 0;
 361         DECLARE_MAC_BUF(mac);
 362 #endif
 363
 364         lbs_deb_enter_args(LBS_DEB_SCAN, "full_scan %d", full_scan);
 365
 366         /* Cancel any partial outstanding partial scans if this scan
 367          * is a full scan.
 368          */
 369         if (full_scan && delayed_work_pending(&priv->scan_work))
 370                 cancel_delayed_work(&priv->scan_work);
 371
 372         /* User-specified bsstype or channel list
 373         TODO: this can be implemented if some user-space application
 374         need the feature. Formerly, it was accessible from debugfs,
 375         but then nowhere used.
 376         if (user_cfg) {
 377                 if (user_cfg->bsstype)
 378                 bsstype = user_cfg->bsstype;
 379         } */
 380
 381         lbs_deb_scan("numchannels %d, bsstype %d\n", numchannels, bsstype);
 382
 383         /* Create list of channels to scan */
 384         chan_list = kzalloc(sizeof(struct chanscanparamset) *
 385                             LBS_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL);
 386         if (!chan_list) {
 387                 lbs_pr_alert("SCAN: chan_list empty\n");
 388                 goto out;
 389         }
 390
 391         /* We want to scan all channels */
 392         chan_count = lbs_scan_create_channel_list(priv, chan_list);
 393
 394         netif_stop_queue(priv->dev);
 395         netif_carrier_off(priv->dev);
 396         if (priv->mesh_dev) {
 397                 netif_stop_queue(priv->mesh_dev);
 398                 netif_carrier_off(priv->mesh_dev);
 399         }
 400
 401         /* Prepare to continue an interrupted scan */
 402         lbs_deb_scan("chan_count %d, scan_channel %d\n",
 403                      chan_count, priv->scan_channel);
 404         curr_chans = chan_list;
 405         /* advance channel list by already-scanned-channels */
 406         if (priv->scan_channel > 0) {
 407                 curr_chans += priv->scan_channel;
 408                 chan_count -= priv->scan_channel;
 409         }
 410
 411         /* Send scan command(s)
 412          * numchannels contains the number of channels we should maximally scan
 413          * chan_count is the total number of channels to scan
 414          */
 415
 416         while (chan_count) {
 417                 int to_scan = min(numchannels, chan_count);
 418                 lbs_deb_scan("scanning %d of %d channels\n",
 419                              to_scan, chan_count);
 420                 ret = lbs_do_scan(priv, bsstype, curr_chans,
 421                                   to_scan);
 422                 if (ret) {
 423                         lbs_pr_err("SCAN_CMD failed\n");
 424                         goto out2;
 425                 }
 426                 curr_chans += to_scan;
 427                 chan_count -= to_scan;
 428
 429                 /* somehow schedule the next part of the scan */
 430                 if (chan_count && !full_scan &&
 431                     !priv->surpriseremoved) {
 432                         /* -1 marks just that we're currently scanning */
 433                         if (priv->scan_channel < 0)
 434                                 priv->scan_channel = to_scan;
 435                         else
 436                                 priv->scan_channel += to_scan;
 437                         cancel_delayed_work(&priv->scan_work);
 438                         queue_delayed_work(priv->work_thread, &priv->scan_work,
 439                                            msecs_to_jiffies(300));
 440                         /* skip over GIWSCAN event */
 441                         goto out;
 442                 }
 443
 444         }
 445         memset(&wrqu, 0, sizeof(union iwreq_data));
 446         wireless_send_event(priv->dev, SIOCGIWSCAN, &wrqu, NULL);
 447
 448 #ifdef CONFIG_LIBERTAS_DEBUG
 449         /* Dump the scan table */
 450         mutex_lock(&priv->lock);
 451         lbs_deb_scan("scan table:\n");
 452         list_for_each_entry(iter, &priv->network_list, list)
 453                 lbs_deb_scan("%02d: BSSID %s, RSSI %d, SSID '%s'\n",
 454                              i++, print_mac(mac, iter->bssid), iter->rssi,
 455                              escape_essid(iter->ssid, iter->ssid_len));
 456         mutex_unlock(&priv->lock);
 457 #endif
 458
 459 out2:
 460         priv->scan_channel = 0;
 461
 462 out:
 463         if (priv->connect_status == LBS_CONNECTED) {
 464                 netif_carrier_on(priv->dev);
 465                 if (!priv->tx_pending_len)
 466                         netif_wake_queue(priv->dev);
 467         }
 468         if (priv->mesh_dev && (priv->mesh_connect_status == LBS_CONNECTED)) {
 469                 netif_carrier_on(priv->mesh_dev);
 470                 if (!priv->tx_pending_len)
 471                         netif_wake_queue(priv->mesh_dev);
 472         }
 473         kfree(chan_list);
 474
 475         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 476         return ret;
 477 }
 478
 479 void lbs_scan_worker(struct work_struct *work)
 480 {
 481         struct lbs_private *priv =
 482                 container_of(work, struct lbs_private, scan_work.work);
 483
 484         lbs_deb_enter(LBS_DEB_SCAN);
 485         lbs_scan_networks(priv, 0);
 486         lbs_deb_leave(LBS_DEB_SCAN);
 487 }
 488
 489
 490 /*********************************************************************/
 491 /*                                                                   */
 492 /*  Result interpretation                                            */
 493 /*                                                                   */
 494 /*********************************************************************/
 495
 496 /**
 497  *  @brief Interpret a BSS scan response returned from the firmware
 498  *
 499  *  Parse the various fixed fields and IEs passed back for a a BSS probe
 500  *  response or beacon from the scan command.  Record information as needed
 501  *  in the scan table struct bss_descriptor for that entry.
 502  *
 503  *  @param bss  Output parameter: Pointer to the BSS Entry
 504  *
 505  *  @return             0 or -1
 506  */
 507 static int lbs_process_bss(struct bss_descriptor *bss,
 508                            uint8_t **pbeaconinfo, int *bytesleft)
 509 {
 510         struct ieeetypes_fhparamset *pFH;
 511         struct ieeetypes_dsparamset *pDS;
 512         struct ieeetypes_cfparamset *pCF;
 513         struct ieeetypes_ibssparamset *pibss;
 514         DECLARE_MAC_BUF(mac);
 515         struct ieeetypes_countryinfoset *pcountryinfo;
 516         uint8_t *pos, *end, *p;
 517         uint8_t n_ex_rates = 0, got_basic_rates = 0, n_basic_rates = 0;
 518         uint16_t beaconsize = 0;
 519         int ret;
 520
 521         lbs_deb_enter(LBS_DEB_SCAN);
 522
 523         if (*bytesleft >= sizeof(beaconsize)) {
 524                 /* Extract & convert beacon size from the command buffer */
 525                 beaconsize = le16_to_cpu(get_unaligned((__le16 *)*pbeaconinfo));
 526                 *bytesleft -= sizeof(beaconsize);
 527                 *pbeaconinfo += sizeof(beaconsize);
 528         }
 529
 530         if (beaconsize == 0 || beaconsize > *bytesleft) {
 531                 *pbeaconinfo += *bytesleft;
 532                 *bytesleft = 0;
 533                 ret = -1;
 534                 goto done;
 535         }
 536
 537         /* Initialize the current working beacon pointer for this BSS iteration */
 538         pos = *pbeaconinfo;
 539         end = pos + beaconsize;
 540
 541         /* Advance the return beacon pointer past the current beacon */
 542         *pbeaconinfo += beaconsize;
 543         *bytesleft -= beaconsize;
 544
 545         memcpy(bss->bssid, pos, ETH_ALEN);
 546         lbs_deb_scan("process_bss: BSSID %s\n", print_mac(mac, bss->bssid));
 547         pos += ETH_ALEN;
 548
 549         if ((end - pos) < 12) {
 550                 lbs_deb_scan("process_bss: Not enough bytes left\n");
 551                 ret = -1;
 552                 goto done;
 553         }
 554
 555         /*
 556          * next 4 fields are RSSI, time stamp, beacon interval,
 557          *   and capability information
 558          */
 559
 560         /* RSSI is 1 byte long */
 561         bss->rssi = *pos;
 562         lbs_deb_scan("process_bss: RSSI %d\n", *pos);
 563         pos++;
 564
 565         /* time stamp is 8 bytes long */
 566         pos += 8;
 567
 568         /* beacon interval is 2 bytes long */
 569         bss->beaconperiod = le16_to_cpup((void *) pos);
 570         pos += 2;
 571
 572         /* capability information is 2 bytes long */
 573         bss->capability = le16_to_cpup((void *) pos);
 574         lbs_deb_scan("process_bss: capabilities 0x%04x\n", bss->capability);
 575         pos += 2;
 576
 577         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 578                 lbs_deb_scan("process_bss: WEP enabled\n");
 579         if (bss->capability & WLAN_CAPABILITY_IBSS)
 580                 bss->mode = IW_MODE_ADHOC;
 581         else
 582                 bss->mode = IW_MODE_INFRA;
 583
 584         /* rest of the current buffer are IE's */
 585         lbs_deb_scan("process_bss: IE len %zd\n", end - pos);
 586         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: IE info", pos, end - pos);
 587
 588         /* process variable IE */
 589         while (pos <= end - 2) {
 590                 struct ieee80211_info_element * elem = (void *)pos;
 591
 592                 if (pos + elem->len > end) {
 593                         lbs_deb_scan("process_bss: error in processing IE, "
 594                                      "bytes left < IE length\n");
 595                         break;
 596                 }
 597
 598                 switch (elem->id) {
 599                 case MFIE_TYPE_SSID:
 600                         bss->ssid_len = elem->len;
 601                         memcpy(bss->ssid, elem->data, elem->len);
 602                         lbs_deb_scan("got SSID IE: '%s', len %u\n",
 603                                      escape_essid(bss->ssid, bss->ssid_len),
 604                                      bss->ssid_len);
 605                         break;
 606
 607                 case MFIE_TYPE_RATES:
 608                         n_basic_rates = min_t(uint8_t, MAX_RATES, elem->len);
 609                         memcpy(bss->rates, elem->data, n_basic_rates);
 610                         got_basic_rates = 1;
 611                         lbs_deb_scan("got RATES IE\n");
 612                         break;
 613
 614                 case MFIE_TYPE_FH_SET:
 615                         pFH = (struct ieeetypes_fhparamset *) pos;
 616                         memmove(&bss->phyparamset.fhparamset, pFH,
 617                                 sizeof(struct ieeetypes_fhparamset));
 618                         lbs_deb_scan("got FH IE\n");
 619                         break;
 620
 621                 case MFIE_TYPE_DS_SET:
 622                         pDS = (struct ieeetypes_dsparamset *) pos;
 623                         bss->channel = pDS->currentchan;
 624                         memcpy(&bss->phyparamset.dsparamset, pDS,
 625                                sizeof(struct ieeetypes_dsparamset));
 626                         lbs_deb_scan("got DS IE, channel %d\n", bss->channel);
 627                         break;
 628
 629                 case MFIE_TYPE_CF_SET:
 630                         pCF = (struct ieeetypes_cfparamset *) pos;
 631                         memcpy(&bss->ssparamset.cfparamset, pCF,
 632                                sizeof(struct ieeetypes_cfparamset));
 633                         lbs_deb_scan("got CF IE\n");
 634                         break;
 635
 636                 case MFIE_TYPE_IBSS_SET:
 637                         pibss = (struct ieeetypes_ibssparamset *) pos;
 638                         bss->atimwindow = le16_to_cpu(pibss->atimwindow);
 639                         memmove(&bss->ssparamset.ibssparamset, pibss,
 640                                 sizeof(struct ieeetypes_ibssparamset));
 641                         lbs_deb_scan("got IBSS IE\n");
 642                         break;
 643
 644                 case MFIE_TYPE_COUNTRY:
 645                         pcountryinfo = (struct ieeetypes_countryinfoset *) pos;
 646                         lbs_deb_scan("got COUNTRY IE\n");
 647                         if (pcountryinfo->len < sizeof(pcountryinfo->countrycode)
 648                             || pcountryinfo->len > 254) {
 649                                 lbs_deb_scan("process_bss: 11D- Err CountryInfo len %d, min %zd, max 254\n",
 650                                              pcountryinfo->len, sizeof(pcountryinfo->countrycode));
 651                                 ret = -1;
 652                                 goto done;
 653                         }
 654
 655                         memcpy(&bss->countryinfo, pcountryinfo, pcountryinfo->len + 2);
 656                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: 11d countryinfo",
 657                                     (uint8_t *) pcountryinfo,
 658                                     (int) (pcountryinfo->len + 2));
 659                         break;
 660
 661                 case MFIE_TYPE_RATES_EX:
 662                         /* only process extended supported rate if data rate is
 663                          * already found. Data rate IE should come before
 664                          * extended supported rate IE
 665                          */
 666                         lbs_deb_scan("got RATESEX IE\n");
 667                         if (!got_basic_rates) {
 668                                 lbs_deb_scan("... but ignoring it\n");
 669                                 break;
 670                         }
 671
 672                         n_ex_rates = elem->len;
 673                         if (n_basic_rates + n_ex_rates > MAX_RATES)
 674                                 n_ex_rates = MAX_RATES - n_basic_rates;
 675
 676                         p = bss->rates + n_basic_rates;
 677                         memcpy(p, elem->data, n_ex_rates);
 678                         break;
 679
 680                 case MFIE_TYPE_GENERIC:
 681                         if (elem->len >= 4 &&
 682                             elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 683                             elem->data[2] == 0xf2 && elem->data[3] == 0x01) {
 684                                 bss->wpa_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 685                                 memcpy(bss->wpa_ie, elem, bss->wpa_ie_len);
 686                                 lbs_deb_scan("got WPA IE\n");
 687                                 lbs_deb_hex(LBS_DEB_SCAN, "WPA IE", bss->wpa_ie, elem->len);
 688                         } else if (elem->len >= MARVELL_MESH_IE_LENGTH &&
 689                                    elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 690                                    elem->data[2] == 0x43 && elem->data[3] == 0x04) {
 691                                 lbs_deb_scan("got mesh IE\n");
 692                                 bss->mesh = 1;
 693                         } else {
 694                                 lbs_deb_scan("got generic IE: %02x:%02x:%02x:%02x, len %d\n",
 695                                         elem->data[0], elem->data[1],
 696                                         elem->data[2], elem->data[3],
 697                                         elem->len);
 698                         }
 699                         break;
 700
 701                 case MFIE_TYPE_RSN:
 702                         lbs_deb_scan("got RSN IE\n");
 703                         bss->rsn_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 704                         memcpy(bss->rsn_ie, elem, bss->rsn_ie_len);
 705                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: RSN_IE",
 706                                     bss->rsn_ie, elem->len);
 707                         break;
 708
 709                 default:
 710                         lbs_deb_scan("got IE 0x%04x, len %d\n",
 711                                      elem->id, elem->len);
 712                         break;
 713                 }
 714
 715                 pos += elem->len + 2;
 716         }
 717
 718         /* Timestamp */
 719         bss->last_scanned = jiffies;
 720         lbs_unset_basic_rate_flags(bss->rates, sizeof(bss->rates));
 721
 722         ret = 0;
 723
 724 done:
 725         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 726         return ret;
 727 }
 728
 729 /**
 730  *  @brief Send a scan command for all available channels filtered on a spec
 731  *
 732  *  Used in association code and from debugfs
 733  *
 734  *  @param priv             A pointer to struct lbs_private structure
 735  *  @param ssid             A pointer to the SSID to scan for
 736  *  @param ssid_len         Length of the SSID
 737  *
 738  *  @return                0-success, otherwise fail
 739  */
 740 int lbs_send_specific_ssid_scan(struct lbs_private *priv, uint8_t *ssid,
 741                                 uint8_t ssid_len)
 742 {
 743         int ret = 0;
 744
 745         lbs_deb_enter_args(LBS_DEB_SCAN, "SSID '%s'\n",
 746                            escape_essid(ssid, ssid_len));
 747
 748         if (!ssid_len)
 749                 goto out;
 750
 751         memcpy(priv->scan_ssid, ssid, ssid_len);
 752         priv->scan_ssid_len = ssid_len;
 753
 754         lbs_scan_networks(priv, 1);
 755         if (priv->surpriseremoved) {
 756                 ret = -1;
 757                 goto out;
 758         }
 759
 760 out:
 761         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 762         return ret;
 763 }
 764
 765
 766
 767
 768 /*********************************************************************/
 769 /*                                                                   */
 770 /*  Support for Wireless Extensions                                  */
 771 /*                                                                   */
 772 /*********************************************************************/
 773
 774
 775 #define MAX_CUSTOM_LEN 64
 776
 777 static inline char *lbs_translate_scan(struct lbs_private *priv,
 778                                        char *start, char *stop,
 779                                        struct bss_descriptor *bss)
 780 {
 781         struct chan_freq_power *cfp;
 782         char *current_val;      /* For rates */
 783         struct iw_event iwe;    /* Temporary buffer */
 784         int j;
 785 #define PERFECT_RSSI ((uint8_t)50)
 786 #define WORST_RSSI   ((uint8_t)0)
 787 #define RSSI_DIFF    ((uint8_t)(PERFECT_RSSI - WORST_RSSI))
 788         uint8_t rssi;
 789
 790         lbs_deb_enter(LBS_DEB_SCAN);
 791
 792         cfp = lbs_find_cfp_by_band_and_channel(priv, 0, bss->channel);
 793         if (!cfp) {
 794                 lbs_deb_scan("Invalid channel number %d\n", bss->channel);
 795                 start = NULL;
 796                 goto out;
 797         }
 798
 799         /* First entry *MUST* be the BSSID */
 800         iwe.cmd = SIOCGIWAP;
 801         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 802         memcpy(iwe.u.ap_addr.sa_data, &bss->bssid, ETH_ALEN);
 803         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_ADDR_LEN);
 804
 805         /* SSID */
 806         iwe.cmd = SIOCGIWESSID;
 807         iwe.u.data.flags = 1;
 808         iwe.u.data.length = min((uint32_t) bss->ssid_len, (uint32_t) IW_ESSID_MAX_SIZE);
 809         start = iwe_stream_add_point(start, stop, &iwe, bss->ssid);
 810
 811         /* Mode */
 812         iwe.cmd = SIOCGIWMODE;
 813         iwe.u.mode = bss->mode;
 814         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_UINT_LEN);
 815
 816         /* Frequency */
 817         iwe.cmd = SIOCGIWFREQ;
 818         iwe.u.freq.m = (long)cfp->freq * 100000;
 819         iwe.u.freq.e = 1;
 820         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_FREQ_LEN);
 821
 822         /* Add quality statistics */
 823         iwe.cmd = IWEVQUAL;
 824         iwe.u.qual.updated = IW_QUAL_ALL_UPDATED;
 825         iwe.u.qual.level = SCAN_RSSI(bss->rssi);
 826
 827         rssi = iwe.u.qual.level - MRVDRV_NF_DEFAULT_SCAN_VALUE;
 828         iwe.u.qual.qual =
 829                 (100 * RSSI_DIFF * RSSI_DIFF - (PERFECT_RSSI - rssi) *
 830                  (15 * (RSSI_DIFF) + 62 * (PERFECT_RSSI - rssi))) /
 831                 (RSSI_DIFF * RSSI_DIFF);
 832         if (iwe.u.qual.qual > 100)
 833                 iwe.u.qual.qual = 100;
 834
 835         if (priv->NF[TYPE_BEACON][TYPE_NOAVG] == 0) {
 836                 iwe.u.qual.noise = MRVDRV_NF_DEFAULT_SCAN_VALUE;
 837         } else {
 838                 iwe.u.qual.noise = CAL_NF(priv->NF[TYPE_BEACON][TYPE_NOAVG]);
 839         }
 840
 841         /* Locally created ad-hoc BSSs won't have beacons if this is the
 842          * only station in the adhoc network; so get signal strength
 843          * from receive statistics.
 844          */
 845         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate
 846             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 847                              priv->curbssparams.ssid_len,
 848                              bss->ssid, bss->ssid_len)) {
 849                 int snr, nf;
 850                 snr = priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 851                 nf = priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 852                 iwe.u.qual.level = CAL_RSSI(snr, nf);
 853         }
 854         start = iwe_stream_add_event(start, stop, &iwe, IW_EV_QUAL_LEN);
 855
 856         /* Add encryption capability */
 857         iwe.cmd = SIOCGIWENCODE;
 858         if (bss->capability & WLAN_CAPABILITY_PRIVACY) {
 859                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 860         } else {
 861                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 862         }
 863         iwe.u.data.length = 0;
 864         start = iwe_stream_add_point(start, stop, &iwe, bss->ssid);
 865
 866         current_val = start + IW_EV_LCP_LEN;
 867
 868         iwe.cmd = SIOCGIWRATE;
 869         iwe.u.bitrate.fixed = 0;
 870         iwe.u.bitrate.disabled = 0;
 871         iwe.u.bitrate.value = 0;
 872
 873         for (j = 0; bss->rates[j] && (j < sizeof(bss->rates)); j++) {
 874                 /* Bit rate given in 500 kb/s units */
 875                 iwe.u.bitrate.value = bss->rates[j] * 500000;
 876                 current_val = iwe_stream_add_value(start, current_val,
 877                                          stop, &iwe, IW_EV_PARAM_LEN);
 878         }
 879         if ((bss->mode == IW_MODE_ADHOC) && priv->adhoccreate
 880             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 881                              priv->curbssparams.ssid_len,
 882                              bss->ssid, bss->ssid_len)) {
 883                 iwe.u.bitrate.value = 22 * 500000;
 884                 current_val = iwe_stream_add_value(start, current_val,
 885                                                    stop, &iwe, IW_EV_PARAM_LEN);
 886         }
 887         /* Check if we added any event */
 888         if((current_val - start) > IW_EV_LCP_LEN)
 889                 start = current_val;
 890
 891         memset(&iwe, 0, sizeof(iwe));
 892         if (bss->wpa_ie_len) {
 893                 char buf[MAX_WPA_IE_LEN];
 894                 memcpy(buf, bss->wpa_ie, bss->wpa_ie_len);
 895                 iwe.cmd = IWEVGENIE;
 896                 iwe.u.data.length = bss->wpa_ie_len;
 897                 start = iwe_stream_add_point(start, stop, &iwe, buf);
 898         }
 899
 900         memset(&iwe, 0, sizeof(iwe));
 901         if (bss->rsn_ie_len) {
 902                 char buf[MAX_WPA_IE_LEN];
 903                 memcpy(buf, bss->rsn_ie, bss->rsn_ie_len);
 904                 iwe.cmd = IWEVGENIE;
 905                 iwe.u.data.length = bss->rsn_ie_len;
 906                 start = iwe_stream_add_point(start, stop, &iwe, buf);
 907         }
 908
 909         if (bss->mesh) {
 910                 char custom[MAX_CUSTOM_LEN];
 911                 char *p = custom;
 912
 913                 iwe.cmd = IWEVCUSTOM;
 914                 p += snprintf(p, MAX_CUSTOM_LEN, "mesh-type: olpc");
 915                 iwe.u.data.length = p - custom;
 916                 if (iwe.u.data.length)
 917                         start = iwe_stream_add_point(start, stop, &iwe, custom);
 918         }
 919
 920 out:
 921         lbs_deb_leave_args(LBS_DEB_SCAN, "start %p", start);
 922         return start;
 923 }
 924
 925
 926 /**
 927  *  @brief Handle Scan Network ioctl
 928  *
 929  *  @param dev          A pointer to net_device structure
 930  *  @param info         A pointer to iw_request_info structure
 931  *  @param vwrq         A pointer to iw_param structure
 932  *  @param extra        A pointer to extra data buf
 933  *
 934  *  @return             0 --success, otherwise fail
 935  */
 936 int lbs_set_scan(struct net_device *dev, struct iw_request_info *info,
 937                  union iwreq_data *wrqu, char *extra)
 938 {
 939         struct lbs_private *priv = dev->priv;
 940         int ret = 0;
 941
 942         lbs_deb_enter(LBS_DEB_WEXT);
 943
 944         if (!netif_running(dev)) {
 945                 ret = -ENETDOWN;
 946                 goto out;
 947         }
 948
 949         /* mac80211 does this:
 950         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 951         if (sdata->type != IEEE80211_IF_TYPE_xxx) {
 952                 ret = -EOPNOTSUPP;
 953                 goto out;
 954         }
 955         */
 956
 957         if (wrqu->data.length == sizeof(struct iw_scan_req) &&
 958             wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 959                 struct iw_scan_req *req = (struct iw_scan_req *)extra;
 960                 priv->scan_ssid_len = req->essid_len;
 961                 memcpy(priv->scan_ssid, req->essid, priv->scan_ssid_len);
 962                 lbs_deb_wext("set_scan, essid '%s'\n",
 963                         escape_essid(priv->scan_ssid, priv->scan_ssid_len));
 964         } else {
 965                 priv->scan_ssid_len = 0;
 966         }
 967
 968         if (!delayed_work_pending(&priv->scan_work))
 969                 queue_delayed_work(priv->work_thread, &priv->scan_work,
 970                                    msecs_to_jiffies(50));
 971         /* set marker that currently a scan is taking place */
 972         priv->scan_channel = -1;
 973
 974         if (priv->surpriseremoved)
 975                 ret = -EIO;
 976
 977 out:
 978         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", ret);
 979         return ret;
 980 }
 981
 982
 983 /**
 984  *  @brief  Handle Retrieve scan table ioctl
 985  *
 986  *  @param dev          A pointer to net_device structure
 987  *  @param info         A pointer to iw_request_info structure
 988  *  @param dwrq         A pointer to iw_point structure
 989  *  @param extra        A pointer to extra data buf
 990  *
 991  *  @return             0 --success, otherwise fail
 992  */
 993 int lbs_get_scan(struct net_device *dev, struct iw_request_info *info,
 994                  struct iw_point *dwrq, char *extra)
 995 {
 996 #define SCAN_ITEM_SIZE 128
 997         struct lbs_private *priv = dev->priv;
 998         int err = 0;
 999         char *ev = extra;
1000         char *stop = ev + dwrq->length;
1001         struct bss_descriptor *iter_bss;
1002         struct bss_descriptor *safe;
1003
1004         lbs_deb_enter(LBS_DEB_WEXT);
1005
1006         /* iwlist should wait until the current scan is finished */
1007         if (priv->scan_channel)
1008                 return -EAGAIN;
1009
1010         /* Update RSSI if current BSS is a locally created ad-hoc BSS */
1011         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate)
1012                 lbs_prepare_and_send_command(priv, CMD_802_11_RSSI, 0,
1013                                              CMD_OPTION_WAITFORRSP, 0, NULL);
1014
1015         mutex_lock(&priv->lock);
1016         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1017                 char *next_ev;
1018                 unsigned long stale_time;
1019
1020                 if (stop - ev < SCAN_ITEM_SIZE) {
1021                         err = -E2BIG;
1022                         break;
1023                 }
1024
1025                 /* For mesh device, list only mesh networks */
1026                 if (dev == priv->mesh_dev && !iter_bss->mesh)
1027                         continue;
1028
1029                 /* Prune old an old scan result */
1030                 stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1031                 if (time_after(jiffies, stale_time)) {
1032                         list_move_tail(&iter_bss->list, &priv->network_free_list);
1033                         clear_bss_descriptor(iter_bss);
1034                         continue;
1035                 }
1036
1037                 /* Translate to WE format this entry */
1038                 next_ev = lbs_translate_scan(priv, ev, stop, iter_bss);
1039                 if (next_ev == NULL)
1040                         continue;
1041                 ev = next_ev;
1042         }
1043         mutex_unlock(&priv->lock);
1044
1045         dwrq->length = (ev - extra);
1046         dwrq->flags = 0;
1047
1048         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", err);
1049         return err;
1050 }
1051
1052
1053
1054
1055 /*********************************************************************/
1056 /*                                                                   */
1057 /*  Command execution                                                */
1058 /*                                                                   */
1059 /*********************************************************************/
1060
1061
1062 /**
1063  *  @brief This function handles the command response of scan
1064  *
1065  *  Called from handle_cmd_response() in cmdrespc.
1066  *
1067  *   The response buffer for the scan command has the following
1068  *      memory layout:
1069  *
1070  *     .-----------------------------------------------------------.
1071  *     |  header (4 * sizeof(u16)):  Standard command response hdr |
1072  *     .-----------------------------------------------------------.
1073  *     |  bufsize (u16) : sizeof the BSS Description data          |
1074  *     .-----------------------------------------------------------.
1075  *     |  NumOfSet (u8) : Number of BSS Descs returned             |
1076  *     .-----------------------------------------------------------.
1077  *     |  BSSDescription data (variable, size given in bufsize)    |
1078  *     .-----------------------------------------------------------.
1079  *     |  TLV data (variable, size calculated using header->size,  |
1080  *     |            bufsize and sizeof the fixed fields above)     |
1081  *     .-----------------------------------------------------------.
1082  *
1083  *  @param priv    A pointer to struct lbs_private structure
1084  *  @param resp    A pointer to cmd_ds_command
1085  *
1086  *  @return        0 or -1
1087  */
1088 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
1089                               struct cmd_header *resp)
1090 {
1091         struct cmd_ds_802_11_scan_rsp *scanresp = (void *)resp;
1092         struct bss_descriptor *iter_bss;
1093         struct bss_descriptor *safe;
1094         uint8_t *bssinfo;
1095         uint16_t scanrespsize;
1096         int bytesleft;
1097         int idx;
1098         int tlvbufsize;
1099         int ret;
1100
1101         lbs_deb_enter(LBS_DEB_SCAN);
1102
1103         /* Prune old entries from scan table */
1104         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1105                 unsigned long stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1106                 if (time_before(jiffies, stale_time))
1107                         continue;
1108                 list_move_tail (&iter_bss->list, &priv->network_free_list);
1109                 clear_bss_descriptor(iter_bss);
1110         }
1111
1112         if (scanresp->nr_sets > MAX_NETWORK_COUNT) {
1113                 lbs_deb_scan("SCAN_RESP: too many scan results (%d, max %d)\n",
1114                              scanresp->nr_sets, MAX_NETWORK_COUNT);
1115                 ret = -1;
1116                 goto done;
1117         }
1118
1119         bytesleft = le16_to_cpu(scanresp->bssdescriptsize);
1120         lbs_deb_scan("SCAN_RESP: bssdescriptsize %d\n", bytesleft);
1121
1122         scanrespsize = le16_to_cpu(resp->size);
1123         lbs_deb_scan("SCAN_RESP: scan results %d\n", scanresp->nr_sets);
1124
1125         bssinfo = scanresp->bssdesc_and_tlvbuffer;
1126
1127         /* The size of the TLV buffer is equal to the entire command response
1128          *   size (scanrespsize) minus the fixed fields (sizeof()'s), the
1129          *   BSS Descriptions (bssdescriptsize as bytesLef) and the command
1130          *   response header (S_DS_GEN)
1131          */
1132         tlvbufsize = scanrespsize - (bytesleft + sizeof(scanresp->bssdescriptsize)
1133                                      + sizeof(scanresp->nr_sets)
1134                                      + S_DS_GEN);
1135
1136         /*
1137          *  Process each scan response returned (scanresp->nr_sets). Save
1138          *    the information in the newbssentry and then insert into the
1139          *    driver scan table either as an update to an existing entry
1140          *    or as an addition at the end of the table
1141          */
1142         for (idx = 0; idx < scanresp->nr_sets && bytesleft; idx++) {
1143                 struct bss_descriptor new;
1144                 struct bss_descriptor *found = NULL;
1145                 struct bss_descriptor *oldest = NULL;
1146                 DECLARE_MAC_BUF(mac);
1147
1148                 /* Process the data fields and IEs returned for this BSS */
1149                 memset(&new, 0, sizeof (struct bss_descriptor));
1150                 if (lbs_process_bss(&new, &bssinfo, &bytesleft) != 0) {
1151                         /* error parsing the scan response, skipped */
1152                         lbs_deb_scan("SCAN_RESP: process_bss returned ERROR\n");
1153                         continue;
1154                 }
1155
1156                 /* Try to find this bss in the scan table */
1157                 list_for_each_entry (iter_bss, &priv->network_list, list) {
1158                         if (is_same_network(iter_bss, &new)) {
1159                                 found = iter_bss;
1160                                 break;
1161                         }
1162
1163                         if ((oldest == NULL) ||
1164                             (iter_bss->last_scanned < oldest->last_scanned))
1165                                 oldest = iter_bss;
1166                 }
1167
1168                 if (found) {
1169                         /* found, clear it */
1170                         clear_bss_descriptor(found);
1171                 } else if (!list_empty(&priv->network_free_list)) {
1172                         /* Pull one from the free list */
1173                         found = list_entry(priv->network_free_list.next,
1174                                            struct bss_descriptor, list);
1175                         list_move_tail(&found->list, &priv->network_list);
1176                 } else if (oldest) {
1177                         /* If there are no more slots, expire the oldest */
1178                         found = oldest;
1179                         clear_bss_descriptor(found);
1180                         list_move_tail(&found->list, &priv->network_list);
1181                 } else {
1182                         continue;
1183                 }
1184
1185                 lbs_deb_scan("SCAN_RESP: BSSID %s\n", print_mac(mac, new.bssid));
1186
1187                 /* Copy the locally created newbssentry to the scan table */
1188                 memcpy(found, &new, offsetof(struct bss_descriptor, list));
1189         }
1190
1191         ret = 0;
1192
1193 done:
1194         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
1195         return ret;
1196 }