SAFE public projects git trees. - safe/jmp/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/types.h>
   8 #include <linux/etherdevice.h>
   9 #include <asm/unaligned.h>
  10
  11 #include <net/lib80211.h>
  12
  13 #include "host.h"
  14 #include "decl.h"
  15 #include "dev.h"
  16 #include "scan.h"
  17 #include "cmd.h"
  18
  19 //! Approximate amount of data needed to pass a scan result back to iwlist
  20 #define MAX_SCAN_CELL_SIZE  (IW_EV_ADDR_LEN             \
  21                              + IW_ESSID_MAX_SIZE        \
  22                              + IW_EV_UINT_LEN           \
  23                              + IW_EV_FREQ_LEN           \
  24                              + IW_EV_QUAL_LEN           \
  25                              + IW_ESSID_MAX_SIZE        \
  26                              + IW_EV_PARAM_LEN          \
  27                              + 40)      /* 40 for WPAIE */
  28
  29 //! Memory needed to store a max sized channel List TLV for a firmware scan
  30 #define CHAN_TLV_MAX_SIZE  (sizeof(struct mrvlietypesheader)    \
  31                             + (MRVDRV_MAX_CHANNELS_PER_SCAN     \
  32                                * sizeof(struct chanscanparamset)))
  33
  34 //! Memory needed to store a max number/size SSID TLV for a firmware scan
  35 #define SSID_TLV_MAX_SIZE  (1 * sizeof(struct mrvlietypes_ssidparamset))
  36
  37 //! Maximum memory needed for a cmd_ds_802_11_scan with all TLVs at max
  38 #define MAX_SCAN_CFG_ALLOC (sizeof(struct cmd_ds_802_11_scan)   \
  39                             + CHAN_TLV_MAX_SIZE + SSID_TLV_MAX_SIZE)
  40
  41 //! The maximum number of channels the firmware can scan per command
  42 #define MRVDRV_MAX_CHANNELS_PER_SCAN   14
  43
  44 /**
  45  * @brief Number of channels to scan per firmware scan command issuance.
  46  *
  47  *  Number restricted to prevent hitting the limit on the amount of scan data
  48  *  returned in a single firmware scan command.
  49  */
  50 #define MRVDRV_CHANNELS_PER_SCAN_CMD   4
  51
  52 //! Scan time specified in the channel TLV for each channel for passive scans
  53 #define MRVDRV_PASSIVE_SCAN_CHAN_TIME  100
  54
  55 //! Scan time specified in the channel TLV for each channel for active scans
  56 #define MRVDRV_ACTIVE_SCAN_CHAN_TIME   100
  57
  58 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
  59                               struct cmd_header *resp);
  60
  61 /*********************************************************************/
  62 /*                                                                   */
  63 /*  Misc helper functions                                            */
  64 /*                                                                   */
  65 /*********************************************************************/
  66
  67 /**
  68  *  @brief Unsets the MSB on basic rates
  69  *
  70  * Scan through an array and unset the MSB for basic data rates.
  71  *
  72  *  @param rates     buffer of data rates
  73  *  @param len       size of buffer
  74  */
  75 static void lbs_unset_basic_rate_flags(u8 *rates, size_t len)
  76 {
  77         int i;
  78
  79         for (i = 0; i < len; i++)
  80                 rates[i] &= 0x7f;
  81 }
  82
  83
  84 static inline void clear_bss_descriptor(struct bss_descriptor *bss)
  85 {
  86         /* Don't blow away ->list, just BSS data */
  87         memset(bss, 0, offsetof(struct bss_descriptor, list));
  88 }
  89
  90 /**
  91  *  @brief Compare two SSIDs
  92  *
  93  *  @param ssid1    A pointer to ssid to compare
  94  *  @param ssid2    A pointer to ssid to compare
  95  *
  96  *  @return         0: ssid is same, otherwise is different
  97  */
  98 int lbs_ssid_cmp(uint8_t *ssid1, uint8_t ssid1_len, uint8_t *ssid2,
  99                  uint8_t ssid2_len)
 100 {
 101         if (ssid1_len != ssid2_len)
 102                 return -1;
 103
 104         return memcmp(ssid1, ssid2, ssid1_len);
 105 }
 106
 107 static inline int is_same_network(struct bss_descriptor *src,
 108                                   struct bss_descriptor *dst)
 109 {
 110         /* A network is only a duplicate if the channel, BSSID, and ESSID
 111          * all match.  We treat all <hidden> with the same BSSID and channel
 112          * as one network */
 113         return ((src->ssid_len == dst->ssid_len) &&
 114                 (src->channel == dst->channel) &&
 115                 !compare_ether_addr(src->bssid, dst->bssid) &&
 116                 !memcmp(src->ssid, dst->ssid, src->ssid_len));
 117 }
 118
 119
 120
 121
 122 /*********************************************************************/
 123 /*                                                                   */
 124 /*  Main scanning support                                            */
 125 /*                                                                   */
 126 /*********************************************************************/
 127
 128 /**
 129  *  @brief Create a channel list for the driver to scan based on region info
 130  *
 131  *  Only used from lbs_scan_setup_scan_config()
 132  *
 133  *  Use the driver region/band information to construct a comprehensive list
 134  *    of channels to scan.  This routine is used for any scan that is not
 135  *    provided a specific channel list to scan.
 136  *
 137  *  @param priv          A pointer to struct lbs_private structure
 138  *  @param scanchanlist  Output parameter: resulting channel list to scan
 139  *
 140  *  @return              void
 141  */
 142 static int lbs_scan_create_channel_list(struct lbs_private *priv,
 143                                         struct chanscanparamset *scanchanlist)
 144 {
 145         struct region_channel *scanregion;
 146         struct chan_freq_power *cfp;
 147         int rgnidx;
 148         int chanidx;
 149         int nextchan;
 150         uint8_t scantype;
 151
 152         chanidx = 0;
 153
 154         /* Set the default scan type to the user specified type, will later
 155          *   be changed to passive on a per channel basis if restricted by
 156          *   regulatory requirements (11d or 11h)
 157          */
 158         scantype = CMD_SCAN_TYPE_ACTIVE;
 159
 160         for (rgnidx = 0; rgnidx < ARRAY_SIZE(priv->region_channel); rgnidx++) {
 161                 if (priv->enable11d && (priv->connect_status != LBS_CONNECTED)
 162                     && (priv->mesh_connect_status != LBS_CONNECTED)) {
 163                         /* Scan all the supported chan for the first scan */
 164                         if (!priv->universal_channel[rgnidx].valid)
 165                                 continue;
 166                         scanregion = &priv->universal_channel[rgnidx];
 167
 168                         /* clear the parsed_region_chan for the first scan */
 169                         memset(&priv->parsed_region_chan, 0x00,
 170                                sizeof(priv->parsed_region_chan));
 171                 } else {
 172                         if (!priv->region_channel[rgnidx].valid)
 173                                 continue;
 174                         scanregion = &priv->region_channel[rgnidx];
 175                 }
 176
 177                 for (nextchan = 0; nextchan < scanregion->nrcfp; nextchan++, chanidx++) {
 178                         struct chanscanparamset *chan = &scanchanlist[chanidx];
 179
 180                         cfp = scanregion->CFP + nextchan;
 181
 182                         if (priv->enable11d)
 183                                 scantype = lbs_get_scan_type_11d(cfp->channel,
 184                                                                  &priv->parsed_region_chan);
 185
 186                         if (scanregion->band == BAND_B || scanregion->band == BAND_G)
 187                                 chan->radiotype = CMD_SCAN_RADIO_TYPE_BG;
 188
 189                         if (scantype == CMD_SCAN_TYPE_PASSIVE) {
 190                                 chan->maxscantime = cpu_to_le16(MRVDRV_PASSIVE_SCAN_CHAN_TIME);
 191                                 chan->chanscanmode.passivescan = 1;
 192                         } else {
 193                                 chan->maxscantime = cpu_to_le16(MRVDRV_ACTIVE_SCAN_CHAN_TIME);
 194                                 chan->chanscanmode.passivescan = 0;
 195                         }
 196
 197                         chan->channumber = cfp->channel;
 198                 }
 199         }
 200         return chanidx;
 201 }
 202
 203 /*
 204  * Add SSID TLV of the form:
 205  *
 206  * TLV-ID SSID     00 00
 207  * length          06 00
 208  * ssid            4d 4e 54 45 53 54
 209  */
 210 static int lbs_scan_add_ssid_tlv(struct lbs_private *priv, u8 *tlv)
 211 {
 212         struct mrvlietypes_ssidparamset *ssid_tlv = (void *)tlv;
 213
 214         ssid_tlv->header.type = cpu_to_le16(TLV_TYPE_SSID);
 215         ssid_tlv->header.len = cpu_to_le16(priv->scan_ssid_len);
 216         memcpy(ssid_tlv->ssid, priv->scan_ssid, priv->scan_ssid_len);
 217         return sizeof(ssid_tlv->header) + priv->scan_ssid_len;
 218 }
 219
 220 /*
 221  * Add CHANLIST TLV of the form
 222  *
 223  * TLV-ID CHANLIST 01 01
 224  * length          5b 00
 225  * channel 1       00 01 00 00 00 64 00
 226  *   radio type    00
 227  *   channel          01
 228  *   scan type           00
 229  *   min scan time          00 00
 230  *   max scan time                64 00
 231  * channel 2       00 02 00 00 00 64 00
 232  * channel 3       00 03 00 00 00 64 00
 233  * channel 4       00 04 00 00 00 64 00
 234  * channel 5       00 05 00 00 00 64 00
 235  * channel 6       00 06 00 00 00 64 00
 236  * channel 7       00 07 00 00 00 64 00
 237  * channel 8       00 08 00 00 00 64 00
 238  * channel 9       00 09 00 00 00 64 00
 239  * channel 10      00 0a 00 00 00 64 00
 240  * channel 11      00 0b 00 00 00 64 00
 241  * channel 12      00 0c 00 00 00 64 00
 242  * channel 13      00 0d 00 00 00 64 00
 243  *
 244  */
 245 static int lbs_scan_add_chanlist_tlv(uint8_t *tlv,
 246                                      struct chanscanparamset *chan_list,
 247                                      int chan_count)
 248 {
 249         size_t size = sizeof(struct chanscanparamset) *chan_count;
 250         struct mrvlietypes_chanlistparamset *chan_tlv = (void *)tlv;
 251
 252         chan_tlv->header.type = cpu_to_le16(TLV_TYPE_CHANLIST);
 253         memcpy(chan_tlv->chanscanparam, chan_list, size);
 254         chan_tlv->header.len = cpu_to_le16(size);
 255         return sizeof(chan_tlv->header) + size;
 256 }
 257
 258 /*
 259  * Add RATES TLV of the form
 260  *
 261  * TLV-ID RATES    01 00
 262  * length          0e 00
 263  * rates           82 84 8b 96 0c 12 18 24 30 48 60 6c
 264  *
 265  * The rates are in lbs_bg_rates[], but for the 802.11b
 266  * rates the high bit isn't set.
 267  */
 268 static int lbs_scan_add_rates_tlv(uint8_t *tlv)
 269 {
 270         int i;
 271         struct mrvlietypes_ratesparamset *rate_tlv = (void *)tlv;
 272
 273         rate_tlv->header.type = cpu_to_le16(TLV_TYPE_RATES);
 274         tlv += sizeof(rate_tlv->header);
 275         for (i = 0; i < MAX_RATES; i++) {
 276                 *tlv = lbs_bg_rates[i];
 277                 if (*tlv == 0)
 278                         break;
 279                 /* This code makes sure that the 802.11b rates (1 MBit/s, 2
 280                    MBit/s, 5.5 MBit/s and 11 MBit/s get's the high bit set.
 281                    Note that the values are MBit/s * 2, to mark them as
 282                    basic rates so that the firmware likes it better */
 283                 if (*tlv == 0x02 || *tlv == 0x04 ||
 284                     *tlv == 0x0b || *tlv == 0x16)
 285                         *tlv |= 0x80;
 286                 tlv++;
 287         }
 288         rate_tlv->header.len = cpu_to_le16(i);
 289         return sizeof(rate_tlv->header) + i;
 290 }
 291
 292 /*
 293  * Generate the CMD_802_11_SCAN command with the proper tlv
 294  * for a bunch of channels.
 295  */
 296 static int lbs_do_scan(struct lbs_private *priv, uint8_t bsstype,
 297                        struct chanscanparamset *chan_list, int chan_count)
 298 {
 299         int ret = -ENOMEM;
 300         struct cmd_ds_802_11_scan *scan_cmd;
 301         uint8_t *tlv;   /* pointer into our current, growing TLV storage area */
 302
 303         lbs_deb_enter_args(LBS_DEB_SCAN, "bsstype %d, chanlist[].chan %d, chan_count %d",
 304                 bsstype, chan_list ? chan_list[0].channumber : -1,
 305                 chan_count);
 306
 307         /* create the fixed part for scan command */
 308         scan_cmd = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL);
 309         if (scan_cmd == NULL)
 310                 goto out;
 311
 312         tlv = scan_cmd->tlvbuffer;
 313         /* TODO: do we need to scan for a specific BSSID?
 314         memcpy(scan_cmd->bssid, priv->scan_bssid, ETH_ALEN); */
 315         scan_cmd->bsstype = bsstype;
 316
 317         /* add TLVs */
 318         if (priv->scan_ssid_len)
 319                 tlv += lbs_scan_add_ssid_tlv(priv, tlv);
 320         if (chan_list && chan_count)
 321                 tlv += lbs_scan_add_chanlist_tlv(tlv, chan_list, chan_count);
 322         tlv += lbs_scan_add_rates_tlv(tlv);
 323
 324         /* This is the final data we are about to send */
 325         scan_cmd->hdr.size = cpu_to_le16(tlv - (uint8_t *)scan_cmd);
 326         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_CMD", (void *)scan_cmd,
 327                     sizeof(*scan_cmd));
 328         lbs_deb_hex(LBS_DEB_SCAN, "SCAN_TLV", scan_cmd->tlvbuffer,
 329                     tlv - scan_cmd->tlvbuffer);
 330
 331         ret = __lbs_cmd(priv, CMD_802_11_SCAN, &scan_cmd->hdr,
 332                         le16_to_cpu(scan_cmd->hdr.size),
 333                         lbs_ret_80211_scan, 0);
 334
 335 out:
 336         kfree(scan_cmd);
 337         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 338         return ret;
 339 }
 340
 341 /**
 342  *  @brief Internal function used to start a scan based on an input config
 343  *
 344  *  Use the input user scan configuration information when provided in
 345  *    order to send the appropriate scan commands to firmware to populate or
 346  *    update the internal driver scan table
 347  *
 348  *  @param priv          A pointer to struct lbs_private structure
 349  *  @param full_scan     Do a full-scan (blocking)
 350  *
 351  *  @return              0 or < 0 if error
 352  */
 353 int lbs_scan_networks(struct lbs_private *priv, int full_scan)
 354 {
 355         int ret = -ENOMEM;
 356         struct chanscanparamset *chan_list;
 357         struct chanscanparamset *curr_chans;
 358         int chan_count;
 359         uint8_t bsstype = CMD_BSS_TYPE_ANY;
 360         int numchannels = MRVDRV_CHANNELS_PER_SCAN_CMD;
 361         union iwreq_data wrqu;
 362 #ifdef CONFIG_LIBERTAS_DEBUG
 363         struct bss_descriptor *iter;
 364         int i = 0;
 365 #endif
 366
 367         lbs_deb_enter_args(LBS_DEB_SCAN, "full_scan %d", full_scan);
 368
 369         /* Cancel any partial outstanding partial scans if this scan
 370          * is a full scan.
 371          */
 372         if (full_scan && delayed_work_pending(&priv->scan_work))
 373                 cancel_delayed_work(&priv->scan_work);
 374
 375         /* User-specified bsstype or channel list
 376         TODO: this can be implemented if some user-space application
 377         need the feature. Formerly, it was accessible from debugfs,
 378         but then nowhere used.
 379         if (user_cfg) {
 380                 if (user_cfg->bsstype)
 381                 bsstype = user_cfg->bsstype;
 382         } */
 383
 384         lbs_deb_scan("numchannels %d, bsstype %d\n", numchannels, bsstype);
 385
 386         /* Create list of channels to scan */
 387         chan_list = kzalloc(sizeof(struct chanscanparamset) *
 388                             LBS_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL);
 389         if (!chan_list) {
 390                 lbs_pr_alert("SCAN: chan_list empty\n");
 391                 goto out;
 392         }
 393
 394         /* We want to scan all channels */
 395         chan_count = lbs_scan_create_channel_list(priv, chan_list);
 396
 397         netif_stop_queue(priv->dev);
 398         netif_carrier_off(priv->dev);
 399         if (priv->mesh_dev) {
 400                 netif_stop_queue(priv->mesh_dev);
 401                 netif_carrier_off(priv->mesh_dev);
 402         }
 403
 404         /* Prepare to continue an interrupted scan */
 405         lbs_deb_scan("chan_count %d, scan_channel %d\n",
 406                      chan_count, priv->scan_channel);
 407         curr_chans = chan_list;
 408         /* advance channel list by already-scanned-channels */
 409         if (priv->scan_channel > 0) {
 410                 curr_chans += priv->scan_channel;
 411                 chan_count -= priv->scan_channel;
 412         }
 413
 414         /* Send scan command(s)
 415          * numchannels contains the number of channels we should maximally scan
 416          * chan_count is the total number of channels to scan
 417          */
 418
 419         while (chan_count) {
 420                 int to_scan = min(numchannels, chan_count);
 421                 lbs_deb_scan("scanning %d of %d channels\n",
 422                              to_scan, chan_count);
 423                 ret = lbs_do_scan(priv, bsstype, curr_chans,
 424                                   to_scan);
 425                 if (ret) {
 426                         lbs_pr_err("SCAN_CMD failed\n");
 427                         goto out2;
 428                 }
 429                 curr_chans += to_scan;
 430                 chan_count -= to_scan;
 431
 432                 /* somehow schedule the next part of the scan */
 433                 if (chan_count && !full_scan &&
 434                     !priv->surpriseremoved) {
 435                         /* -1 marks just that we're currently scanning */
 436                         if (priv->scan_channel < 0)
 437                                 priv->scan_channel = to_scan;
 438                         else
 439                                 priv->scan_channel += to_scan;
 440                         cancel_delayed_work(&priv->scan_work);
 441                         queue_delayed_work(priv->work_thread, &priv->scan_work,
 442                                            msecs_to_jiffies(300));
 443                         /* skip over GIWSCAN event */
 444                         goto out;
 445                 }
 446
 447         }
 448         memset(&wrqu, 0, sizeof(union iwreq_data));
 449         wireless_send_event(priv->dev, SIOCGIWSCAN, &wrqu, NULL);
 450
 451 #ifdef CONFIG_LIBERTAS_DEBUG
 452         /* Dump the scan table */
 453         mutex_lock(&priv->lock);
 454         lbs_deb_scan("scan table:\n");
 455         list_for_each_entry(iter, &priv->network_list, list)
 456                 lbs_deb_scan("%02d: BSSID %pM, RSSI %d, SSID '%s'\n",
 457                              i++, iter->bssid, iter->rssi,
 458                              escape_ssid(iter->ssid, iter->ssid_len));
 459         mutex_unlock(&priv->lock);
 460 #endif
 461
 462 out2:
 463         priv->scan_channel = 0;
 464
 465 out:
 466         if (priv->connect_status == LBS_CONNECTED) {
 467                 netif_carrier_on(priv->dev);
 468                 if (!priv->tx_pending_len)
 469                         netif_wake_queue(priv->dev);
 470         }
 471         if (priv->mesh_dev && (priv->mesh_connect_status == LBS_CONNECTED)) {
 472                 netif_carrier_on(priv->mesh_dev);
 473                 if (!priv->tx_pending_len)
 474                         netif_wake_queue(priv->mesh_dev);
 475         }
 476         kfree(chan_list);
 477
 478         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 479         return ret;
 480 }
 481
 482 void lbs_scan_worker(struct work_struct *work)
 483 {
 484         struct lbs_private *priv =
 485                 container_of(work, struct lbs_private, scan_work.work);
 486
 487         lbs_deb_enter(LBS_DEB_SCAN);
 488         lbs_scan_networks(priv, 0);
 489         lbs_deb_leave(LBS_DEB_SCAN);
 490 }
 491
 492
 493 /*********************************************************************/
 494 /*                                                                   */
 495 /*  Result interpretation                                            */
 496 /*                                                                   */
 497 /*********************************************************************/
 498
 499 /**
 500  *  @brief Interpret a BSS scan response returned from the firmware
 501  *
 502  *  Parse the various fixed fields and IEs passed back for a a BSS probe
 503  *  response or beacon from the scan command.  Record information as needed
 504  *  in the scan table struct bss_descriptor for that entry.
 505  *
 506  *  @param bss  Output parameter: Pointer to the BSS Entry
 507  *
 508  *  @return             0 or -1
 509  */
 510 static int lbs_process_bss(struct bss_descriptor *bss,
 511                            uint8_t **pbeaconinfo, int *bytesleft)
 512 {
 513         struct ieeetypes_fhparamset *pFH;
 514         struct ieeetypes_dsparamset *pDS;
 515         struct ieeetypes_cfparamset *pCF;
 516         struct ieeetypes_ibssparamset *pibss;
 517         struct ieeetypes_countryinfoset *pcountryinfo;
 518         uint8_t *pos, *end, *p;
 519         uint8_t n_ex_rates = 0, got_basic_rates = 0, n_basic_rates = 0;
 520         uint16_t beaconsize = 0;
 521         int ret;
 522
 523         lbs_deb_enter(LBS_DEB_SCAN);
 524
 525         if (*bytesleft >= sizeof(beaconsize)) {
 526                 /* Extract & convert beacon size from the command buffer */
 527                 beaconsize = get_unaligned_le16(*pbeaconinfo);
 528                 *bytesleft -= sizeof(beaconsize);
 529                 *pbeaconinfo += sizeof(beaconsize);
 530         }
 531
 532         if (beaconsize == 0 || beaconsize > *bytesleft) {
 533                 *pbeaconinfo += *bytesleft;
 534                 *bytesleft = 0;
 535                 ret = -1;
 536                 goto done;
 537         }
 538
 539         /* Initialize the current working beacon pointer for this BSS iteration */
 540         pos = *pbeaconinfo;
 541         end = pos + beaconsize;
 542
 543         /* Advance the return beacon pointer past the current beacon */
 544         *pbeaconinfo += beaconsize;
 545         *bytesleft -= beaconsize;
 546
 547         memcpy(bss->bssid, pos, ETH_ALEN);
 548         lbs_deb_scan("process_bss: BSSID %pM\n", bss->bssid);
 549         pos += ETH_ALEN;
 550
 551         if ((end - pos) < 12) {
 552                 lbs_deb_scan("process_bss: Not enough bytes left\n");
 553                 ret = -1;
 554                 goto done;
 555         }
 556
 557         /*
 558          * next 4 fields are RSSI, time stamp, beacon interval,
 559          *   and capability information
 560          */
 561
 562         /* RSSI is 1 byte long */
 563         bss->rssi = *pos;
 564         lbs_deb_scan("process_bss: RSSI %d\n", *pos);
 565         pos++;
 566
 567         /* time stamp is 8 bytes long */
 568         pos += 8;
 569
 570         /* beacon interval is 2 bytes long */
 571         bss->beaconperiod = get_unaligned_le16(pos);
 572         pos += 2;
 573
 574         /* capability information is 2 bytes long */
 575         bss->capability = get_unaligned_le16(pos);
 576         lbs_deb_scan("process_bss: capabilities 0x%04x\n", bss->capability);
 577         pos += 2;
 578
 579         if (bss->capability & WLAN_CAPABILITY_PRIVACY)
 580                 lbs_deb_scan("process_bss: WEP enabled\n");
 581         if (bss->capability & WLAN_CAPABILITY_IBSS)
 582                 bss->mode = IW_MODE_ADHOC;
 583         else
 584                 bss->mode = IW_MODE_INFRA;
 585
 586         /* rest of the current buffer are IE's */
 587         lbs_deb_scan("process_bss: IE len %zd\n", end - pos);
 588         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: IE info", pos, end - pos);
 589
 590         /* process variable IE */
 591         while (pos <= end - 2) {
 592                 struct ieee80211_info_element * elem = (void *)pos;
 593
 594                 if (pos + elem->len > end) {
 595                         lbs_deb_scan("process_bss: error in processing IE, "
 596                                      "bytes left < IE length\n");
 597                         break;
 598                 }
 599
 600                 switch (elem->id) {
 601                 case MFIE_TYPE_SSID:
 602                         bss->ssid_len = min_t(int, 32, elem->len);
 603                         memcpy(bss->ssid, elem->data, bss->ssid_len);
 604                         lbs_deb_scan("got SSID IE: '%s', len %u\n",
 605                                      escape_ssid(bss->ssid, bss->ssid_len),
 606                                      bss->ssid_len);
 607                         break;
 608
 609                 case MFIE_TYPE_RATES:
 610                         n_basic_rates = min_t(uint8_t, MAX_RATES, elem->len);
 611                         memcpy(bss->rates, elem->data, n_basic_rates);
 612                         got_basic_rates = 1;
 613                         lbs_deb_scan("got RATES IE\n");
 614                         break;
 615
 616                 case MFIE_TYPE_FH_SET:
 617                         pFH = (struct ieeetypes_fhparamset *) pos;
 618                         memmove(&bss->phyparamset.fhparamset, pFH,
 619                                 sizeof(struct ieeetypes_fhparamset));
 620                         lbs_deb_scan("got FH IE\n");
 621                         break;
 622
 623                 case MFIE_TYPE_DS_SET:
 624                         pDS = (struct ieeetypes_dsparamset *) pos;
 625                         bss->channel = pDS->currentchan;
 626                         memcpy(&bss->phyparamset.dsparamset, pDS,
 627                                sizeof(struct ieeetypes_dsparamset));
 628                         lbs_deb_scan("got DS IE, channel %d\n", bss->channel);
 629                         break;
 630
 631                 case MFIE_TYPE_CF_SET:
 632                         pCF = (struct ieeetypes_cfparamset *) pos;
 633                         memcpy(&bss->ssparamset.cfparamset, pCF,
 634                                sizeof(struct ieeetypes_cfparamset));
 635                         lbs_deb_scan("got CF IE\n");
 636                         break;
 637
 638                 case MFIE_TYPE_IBSS_SET:
 639                         pibss = (struct ieeetypes_ibssparamset *) pos;
 640                         bss->atimwindow = le16_to_cpu(pibss->atimwindow);
 641                         memmove(&bss->ssparamset.ibssparamset, pibss,
 642                                 sizeof(struct ieeetypes_ibssparamset));
 643                         lbs_deb_scan("got IBSS IE\n");
 644                         break;
 645
 646                 case MFIE_TYPE_COUNTRY:
 647                         pcountryinfo = (struct ieeetypes_countryinfoset *) pos;
 648                         lbs_deb_scan("got COUNTRY IE\n");
 649                         if (pcountryinfo->len < sizeof(pcountryinfo->countrycode)
 650                             || pcountryinfo->len > 254) {
 651                                 lbs_deb_scan("process_bss: 11D- Err CountryInfo len %d, min %zd, max 254\n",
 652                                              pcountryinfo->len, sizeof(pcountryinfo->countrycode));
 653                                 ret = -1;
 654                                 goto done;
 655                         }
 656
 657                         memcpy(&bss->countryinfo, pcountryinfo, pcountryinfo->len + 2);
 658                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: 11d countryinfo",
 659                                     (uint8_t *) pcountryinfo,
 660                                     (int) (pcountryinfo->len + 2));
 661                         break;
 662
 663                 case MFIE_TYPE_RATES_EX:
 664                         /* only process extended supported rate if data rate is
 665                          * already found. Data rate IE should come before
 666                          * extended supported rate IE
 667                          */
 668                         lbs_deb_scan("got RATESEX IE\n");
 669                         if (!got_basic_rates) {
 670                                 lbs_deb_scan("... but ignoring it\n");
 671                                 break;
 672                         }
 673
 674                         n_ex_rates = elem->len;
 675                         if (n_basic_rates + n_ex_rates > MAX_RATES)
 676                                 n_ex_rates = MAX_RATES - n_basic_rates;
 677
 678                         p = bss->rates + n_basic_rates;
 679                         memcpy(p, elem->data, n_ex_rates);
 680                         break;
 681
 682                 case MFIE_TYPE_GENERIC:
 683                         if (elem->len >= 4 &&
 684                             elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 685                             elem->data[2] == 0xf2 && elem->data[3] == 0x01) {
 686                                 bss->wpa_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 687                                 memcpy(bss->wpa_ie, elem, bss->wpa_ie_len);
 688                                 lbs_deb_scan("got WPA IE\n");
 689                                 lbs_deb_hex(LBS_DEB_SCAN, "WPA IE", bss->wpa_ie, elem->len);
 690                         } else if (elem->len >= MARVELL_MESH_IE_LENGTH &&
 691                                    elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
 692                                    elem->data[2] == 0x43 && elem->data[3] == 0x04) {
 693                                 lbs_deb_scan("got mesh IE\n");
 694                                 bss->mesh = 1;
 695                         } else {
 696                                 lbs_deb_scan("got generic IE: %02x:%02x:%02x:%02x, len %d\n",
 697                                         elem->data[0], elem->data[1],
 698                                         elem->data[2], elem->data[3],
 699                                         elem->len);
 700                         }
 701                         break;
 702
 703                 case MFIE_TYPE_RSN:
 704                         lbs_deb_scan("got RSN IE\n");
 705                         bss->rsn_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
 706                         memcpy(bss->rsn_ie, elem, bss->rsn_ie_len);
 707                         lbs_deb_hex(LBS_DEB_SCAN, "process_bss: RSN_IE",
 708                                     bss->rsn_ie, elem->len);
 709                         break;
 710
 711                 default:
 712                         lbs_deb_scan("got IE 0x%04x, len %d\n",
 713                                      elem->id, elem->len);
 714                         break;
 715                 }
 716
 717                 pos += elem->len + 2;
 718         }
 719
 720         /* Timestamp */
 721         bss->last_scanned = jiffies;
 722         lbs_unset_basic_rate_flags(bss->rates, sizeof(bss->rates));
 723
 724         ret = 0;
 725
 726 done:
 727         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 728         return ret;
 729 }
 730
 731 /**
 732  *  @brief Send a scan command for all available channels filtered on a spec
 733  *
 734  *  Used in association code and from debugfs
 735  *
 736  *  @param priv             A pointer to struct lbs_private structure
 737  *  @param ssid             A pointer to the SSID to scan for
 738  *  @param ssid_len         Length of the SSID
 739  *
 740  *  @return                0-success, otherwise fail
 741  */
 742 int lbs_send_specific_ssid_scan(struct lbs_private *priv, uint8_t *ssid,
 743                                 uint8_t ssid_len)
 744 {
 745         int ret = 0;
 746
 747         lbs_deb_enter_args(LBS_DEB_SCAN, "SSID '%s'\n",
 748                            escape_ssid(ssid, ssid_len));
 749
 750         if (!ssid_len)
 751                 goto out;
 752
 753         memcpy(priv->scan_ssid, ssid, ssid_len);
 754         priv->scan_ssid_len = ssid_len;
 755
 756         lbs_scan_networks(priv, 1);
 757         if (priv->surpriseremoved) {
 758                 ret = -1;
 759                 goto out;
 760         }
 761
 762 out:
 763         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
 764         return ret;
 765 }
 766
 767
 768
 769
 770 /*********************************************************************/
 771 /*                                                                   */
 772 /*  Support for Wireless Extensions                                  */
 773 /*                                                                   */
 774 /*********************************************************************/
 775
 776
 777 #define MAX_CUSTOM_LEN 64
 778
 779 static inline char *lbs_translate_scan(struct lbs_private *priv,
 780                                             struct iw_request_info *info,
 781                                             char *start, char *stop,
 782                                             struct bss_descriptor *bss)
 783 {
 784         struct chan_freq_power *cfp;
 785         char *current_val;      /* For rates */
 786         struct iw_event iwe;    /* Temporary buffer */
 787         int j;
 788 #define PERFECT_RSSI ((uint8_t)50)
 789 #define WORST_RSSI   ((uint8_t)0)
 790 #define RSSI_DIFF    ((uint8_t)(PERFECT_RSSI - WORST_RSSI))
 791         uint8_t rssi;
 792
 793         lbs_deb_enter(LBS_DEB_SCAN);
 794
 795         cfp = lbs_find_cfp_by_band_and_channel(priv, 0, bss->channel);
 796         if (!cfp) {
 797                 lbs_deb_scan("Invalid channel number %d\n", bss->channel);
 798                 start = NULL;
 799                 goto out;
 800         }
 801
 802         /* First entry *MUST* be the BSSID */
 803         iwe.cmd = SIOCGIWAP;
 804         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 805         memcpy(iwe.u.ap_addr.sa_data, &bss->bssid, ETH_ALEN);
 806         start = iwe_stream_add_event(info, start, stop, &iwe, IW_EV_ADDR_LEN);
 807
 808         /* SSID */
 809         iwe.cmd = SIOCGIWESSID;
 810         iwe.u.data.flags = 1;
 811         iwe.u.data.length = min((uint32_t) bss->ssid_len, (uint32_t) IW_ESSID_MAX_SIZE);
 812         start = iwe_stream_add_point(info, start, stop, &iwe, bss->ssid);
 813
 814         /* Mode */
 815         iwe.cmd = SIOCGIWMODE;
 816         iwe.u.mode = bss->mode;
 817         start = iwe_stream_add_event(info, start, stop, &iwe, IW_EV_UINT_LEN);
 818
 819         /* Frequency */
 820         iwe.cmd = SIOCGIWFREQ;
 821         iwe.u.freq.m = (long)cfp->freq * 100000;
 822         iwe.u.freq.e = 1;
 823         start = iwe_stream_add_event(info, start, stop, &iwe, IW_EV_FREQ_LEN);
 824
 825         /* Add quality statistics */
 826         iwe.cmd = IWEVQUAL;
 827         iwe.u.qual.updated = IW_QUAL_ALL_UPDATED;
 828         iwe.u.qual.level = SCAN_RSSI(bss->rssi);
 829
 830         rssi = iwe.u.qual.level - MRVDRV_NF_DEFAULT_SCAN_VALUE;
 831         iwe.u.qual.qual =
 832                 (100 * RSSI_DIFF * RSSI_DIFF - (PERFECT_RSSI - rssi) *
 833                  (15 * (RSSI_DIFF) + 62 * (PERFECT_RSSI - rssi))) /
 834                 (RSSI_DIFF * RSSI_DIFF);
 835         if (iwe.u.qual.qual > 100)
 836                 iwe.u.qual.qual = 100;
 837
 838         if (priv->NF[TYPE_BEACON][TYPE_NOAVG] == 0) {
 839                 iwe.u.qual.noise = MRVDRV_NF_DEFAULT_SCAN_VALUE;
 840         } else {
 841                 iwe.u.qual.noise = CAL_NF(priv->NF[TYPE_BEACON][TYPE_NOAVG]);
 842         }
 843
 844         /* Locally created ad-hoc BSSs won't have beacons if this is the
 845          * only station in the adhoc network; so get signal strength
 846          * from receive statistics.
 847          */
 848         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate
 849             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 850                              priv->curbssparams.ssid_len,
 851                              bss->ssid, bss->ssid_len)) {
 852                 int snr, nf;
 853                 snr = priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 854                 nf = priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE;
 855                 iwe.u.qual.level = CAL_RSSI(snr, nf);
 856         }
 857         start = iwe_stream_add_event(info, start, stop, &iwe, IW_EV_QUAL_LEN);
 858
 859         /* Add encryption capability */
 860         iwe.cmd = SIOCGIWENCODE;
 861         if (bss->capability & WLAN_CAPABILITY_PRIVACY) {
 862                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
 863         } else {
 864                 iwe.u.data.flags = IW_ENCODE_DISABLED;
 865         }
 866         iwe.u.data.length = 0;
 867         start = iwe_stream_add_point(info, start, stop, &iwe, bss->ssid);
 868
 869         current_val = start + iwe_stream_lcp_len(info);
 870
 871         iwe.cmd = SIOCGIWRATE;
 872         iwe.u.bitrate.fixed = 0;
 873         iwe.u.bitrate.disabled = 0;
 874         iwe.u.bitrate.value = 0;
 875
 876         for (j = 0; bss->rates[j] && (j < sizeof(bss->rates)); j++) {
 877                 /* Bit rate given in 500 kb/s units */
 878                 iwe.u.bitrate.value = bss->rates[j] * 500000;
 879                 current_val = iwe_stream_add_value(info, start, current_val,
 880                                                    stop, &iwe, IW_EV_PARAM_LEN);
 881         }
 882         if ((bss->mode == IW_MODE_ADHOC) && priv->adhoccreate
 883             && !lbs_ssid_cmp(priv->curbssparams.ssid,
 884                              priv->curbssparams.ssid_len,
 885                              bss->ssid, bss->ssid_len)) {
 886                 iwe.u.bitrate.value = 22 * 500000;
 887                 current_val = iwe_stream_add_value(info, start, current_val,
 888                                                    stop, &iwe, IW_EV_PARAM_LEN);
 889         }
 890         /* Check if we added any event */
 891         if ((current_val - start) > iwe_stream_lcp_len(info))
 892                 start = current_val;
 893
 894         memset(&iwe, 0, sizeof(iwe));
 895         if (bss->wpa_ie_len) {
 896                 char buf[MAX_WPA_IE_LEN];
 897                 memcpy(buf, bss->wpa_ie, bss->wpa_ie_len);
 898                 iwe.cmd = IWEVGENIE;
 899                 iwe.u.data.length = bss->wpa_ie_len;
 900                 start = iwe_stream_add_point(info, start, stop, &iwe, buf);
 901         }
 902
 903         memset(&iwe, 0, sizeof(iwe));
 904         if (bss->rsn_ie_len) {
 905                 char buf[MAX_WPA_IE_LEN];
 906                 memcpy(buf, bss->rsn_ie, bss->rsn_ie_len);
 907                 iwe.cmd = IWEVGENIE;
 908                 iwe.u.data.length = bss->rsn_ie_len;
 909                 start = iwe_stream_add_point(info, start, stop, &iwe, buf);
 910         }
 911
 912         if (bss->mesh) {
 913                 char custom[MAX_CUSTOM_LEN];
 914                 char *p = custom;
 915
 916                 iwe.cmd = IWEVCUSTOM;
 917                 p += snprintf(p, MAX_CUSTOM_LEN, "mesh-type: olpc");
 918                 iwe.u.data.length = p - custom;
 919                 if (iwe.u.data.length)
 920                         start = iwe_stream_add_point(info, start, stop,
 921                                                      &iwe, custom);
 922         }
 923
 924 out:
 925         lbs_deb_leave_args(LBS_DEB_SCAN, "start %p", start);
 926         return start;
 927 }
 928
 929
 930 /**
 931  *  @brief Handle Scan Network ioctl
 932  *
 933  *  @param dev          A pointer to net_device structure
 934  *  @param info         A pointer to iw_request_info structure
 935  *  @param vwrq         A pointer to iw_param structure
 936  *  @param extra        A pointer to extra data buf
 937  *
 938  *  @return             0 --success, otherwise fail
 939  */
 940 int lbs_set_scan(struct net_device *dev, struct iw_request_info *info,
 941                  union iwreq_data *wrqu, char *extra)
 942 {
 943         struct lbs_private *priv = dev->priv;
 944         int ret = 0;
 945
 946         lbs_deb_enter(LBS_DEB_WEXT);
 947
 948         if (!priv->radio_on) {
 949                 ret = -EINVAL;
 950                 goto out;
 951         }
 952
 953         if (!netif_running(dev)) {
 954                 ret = -ENETDOWN;
 955                 goto out;
 956         }
 957
 958         /* mac80211 does this:
 959         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 960         if (sdata->type != IEEE80211_IF_TYPE_xxx) {
 961                 ret = -EOPNOTSUPP;
 962                 goto out;
 963         }
 964         */
 965
 966         if (wrqu->data.length == sizeof(struct iw_scan_req) &&
 967             wrqu->data.flags & IW_SCAN_THIS_ESSID) {
 968                 struct iw_scan_req *req = (struct iw_scan_req *)extra;
 969                 priv->scan_ssid_len = req->essid_len;
 970                 memcpy(priv->scan_ssid, req->essid, priv->scan_ssid_len);
 971                 lbs_deb_wext("set_scan, essid '%s'\n",
 972                         escape_ssid(priv->scan_ssid, priv->scan_ssid_len));
 973         } else {
 974                 priv->scan_ssid_len = 0;
 975         }
 976
 977         if (!delayed_work_pending(&priv->scan_work))
 978                 queue_delayed_work(priv->work_thread, &priv->scan_work,
 979                                    msecs_to_jiffies(50));
 980         /* set marker that currently a scan is taking place */
 981         priv->scan_channel = -1;
 982
 983         if (priv->surpriseremoved)
 984                 ret = -EIO;
 985
 986 out:
 987         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", ret);
 988         return ret;
 989 }
 990
 991
 992 /**
 993  *  @brief  Handle Retrieve scan table ioctl
 994  *
 995  *  @param dev          A pointer to net_device structure
 996  *  @param info         A pointer to iw_request_info structure
 997  *  @param dwrq         A pointer to iw_point structure
 998  *  @param extra        A pointer to extra data buf
 999  *
1000  *  @return             0 --success, otherwise fail
1001  */
1002 int lbs_get_scan(struct net_device *dev, struct iw_request_info *info,
1003                  struct iw_point *dwrq, char *extra)
1004 {
1005 #define SCAN_ITEM_SIZE 128
1006         struct lbs_private *priv = dev->priv;
1007         int err = 0;
1008         char *ev = extra;
1009         char *stop = ev + dwrq->length;
1010         struct bss_descriptor *iter_bss;
1011         struct bss_descriptor *safe;
1012
1013         lbs_deb_enter(LBS_DEB_WEXT);
1014
1015         /* iwlist should wait until the current scan is finished */
1016         if (priv->scan_channel)
1017                 return -EAGAIN;
1018
1019         /* Update RSSI if current BSS is a locally created ad-hoc BSS */
1020         if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate)
1021                 lbs_prepare_and_send_command(priv, CMD_802_11_RSSI, 0,
1022                                              CMD_OPTION_WAITFORRSP, 0, NULL);
1023
1024         mutex_lock(&priv->lock);
1025         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1026                 char *next_ev;
1027                 unsigned long stale_time;
1028
1029                 if (stop - ev < SCAN_ITEM_SIZE) {
1030                         err = -E2BIG;
1031                         break;
1032                 }
1033
1034                 /* For mesh device, list only mesh networks */
1035                 if (dev == priv->mesh_dev && !iter_bss->mesh)
1036                         continue;
1037
1038                 /* Prune old an old scan result */
1039                 stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1040                 if (time_after(jiffies, stale_time)) {
1041                         list_move_tail(&iter_bss->list, &priv->network_free_list);
1042                         clear_bss_descriptor(iter_bss);
1043                         continue;
1044                 }
1045
1046                 /* Translate to WE format this entry */
1047                 next_ev = lbs_translate_scan(priv, info, ev, stop, iter_bss);
1048                 if (next_ev == NULL)
1049                         continue;
1050                 ev = next_ev;
1051         }
1052         mutex_unlock(&priv->lock);
1053
1054         dwrq->length = (ev - extra);
1055         dwrq->flags = 0;
1056
1057         lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", err);
1058         return err;
1059 }
1060
1061
1062
1063
1064 /*********************************************************************/
1065 /*                                                                   */
1066 /*  Command execution                                                */
1067 /*                                                                   */
1068 /*********************************************************************/
1069
1070
1071 /**
1072  *  @brief This function handles the command response of scan
1073  *
1074  *  Called from handle_cmd_response() in cmdrespc.
1075  *
1076  *   The response buffer for the scan command has the following
1077  *      memory layout:
1078  *
1079  *     .-----------------------------------------------------------.
1080  *     |  header (4 * sizeof(u16)):  Standard command response hdr |
1081  *     .-----------------------------------------------------------.
1082  *     |  bufsize (u16) : sizeof the BSS Description data          |
1083  *     .-----------------------------------------------------------.
1084  *     |  NumOfSet (u8) : Number of BSS Descs returned             |
1085  *     .-----------------------------------------------------------.
1086  *     |  BSSDescription data (variable, size given in bufsize)    |
1087  *     .-----------------------------------------------------------.
1088  *     |  TLV data (variable, size calculated using header->size,  |
1089  *     |            bufsize and sizeof the fixed fields above)     |
1090  *     .-----------------------------------------------------------.
1091  *
1092  *  @param priv    A pointer to struct lbs_private structure
1093  *  @param resp    A pointer to cmd_ds_command
1094  *
1095  *  @return        0 or -1
1096  */
1097 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy,
1098                               struct cmd_header *resp)
1099 {
1100         struct cmd_ds_802_11_scan_rsp *scanresp = (void *)resp;
1101         struct bss_descriptor *iter_bss;
1102         struct bss_descriptor *safe;
1103         uint8_t *bssinfo;
1104         uint16_t scanrespsize;
1105         int bytesleft;
1106         int idx;
1107         int tlvbufsize;
1108         int ret;
1109
1110         lbs_deb_enter(LBS_DEB_SCAN);
1111
1112         /* Prune old entries from scan table */
1113         list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) {
1114                 unsigned long stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE;
1115                 if (time_before(jiffies, stale_time))
1116                         continue;
1117                 list_move_tail (&iter_bss->list, &priv->network_free_list);
1118                 clear_bss_descriptor(iter_bss);
1119         }
1120
1121         if (scanresp->nr_sets > MAX_NETWORK_COUNT) {
1122                 lbs_deb_scan("SCAN_RESP: too many scan results (%d, max %d)\n",
1123                              scanresp->nr_sets, MAX_NETWORK_COUNT);
1124                 ret = -1;
1125                 goto done;
1126         }
1127
1128         bytesleft = le16_to_cpu(scanresp->bssdescriptsize);
1129         lbs_deb_scan("SCAN_RESP: bssdescriptsize %d\n", bytesleft);
1130
1131         scanrespsize = le16_to_cpu(resp->size);
1132         lbs_deb_scan("SCAN_RESP: scan results %d\n", scanresp->nr_sets);
1133
1134         bssinfo = scanresp->bssdesc_and_tlvbuffer;
1135
1136         /* The size of the TLV buffer is equal to the entire command response
1137          *   size (scanrespsize) minus the fixed fields (sizeof()'s), the
1138          *   BSS Descriptions (bssdescriptsize as bytesLef) and the command
1139          *   response header (S_DS_GEN)
1140          */
1141         tlvbufsize = scanrespsize - (bytesleft + sizeof(scanresp->bssdescriptsize)
1142                                      + sizeof(scanresp->nr_sets)
1143                                      + S_DS_GEN);
1144
1145         /*
1146          *  Process each scan response returned (scanresp->nr_sets). Save
1147          *    the information in the newbssentry and then insert into the
1148          *    driver scan table either as an update to an existing entry
1149          *    or as an addition at the end of the table
1150          */
1151         for (idx = 0; idx < scanresp->nr_sets && bytesleft; idx++) {
1152                 struct bss_descriptor new;
1153                 struct bss_descriptor *found = NULL;
1154                 struct bss_descriptor *oldest = NULL;
1155
1156                 /* Process the data fields and IEs returned for this BSS */
1157                 memset(&new, 0, sizeof (struct bss_descriptor));
1158                 if (lbs_process_bss(&new, &bssinfo, &bytesleft) != 0) {
1159                         /* error parsing the scan response, skipped */
1160                         lbs_deb_scan("SCAN_RESP: process_bss returned ERROR\n");
1161                         continue;
1162                 }
1163
1164                 /* Try to find this bss in the scan table */
1165                 list_for_each_entry (iter_bss, &priv->network_list, list) {
1166                         if (is_same_network(iter_bss, &new)) {
1167                                 found = iter_bss;
1168                                 break;
1169                         }
1170
1171                         if ((oldest == NULL) ||
1172                             (iter_bss->last_scanned < oldest->last_scanned))
1173                                 oldest = iter_bss;
1174                 }
1175
1176                 if (found) {
1177                         /* found, clear it */
1178                         clear_bss_descriptor(found);
1179                 } else if (!list_empty(&priv->network_free_list)) {
1180                         /* Pull one from the free list */
1181                         found = list_entry(priv->network_free_list.next,
1182                                            struct bss_descriptor, list);
1183                         list_move_tail(&found->list, &priv->network_list);
1184                 } else if (oldest) {
1185                         /* If there are no more slots, expire the oldest */
1186                         found = oldest;
1187                         clear_bss_descriptor(found);
1188                         list_move_tail(&found->list, &priv->network_list);
1189                 } else {
1190                         continue;
1191                 }
1192
1193                 lbs_deb_scan("SCAN_RESP: BSSID %pM\n", new.bssid);
1194
1195                 /* Copy the locally created newbssentry to the scan table */
1196                 memcpy(found, &new, offsetof(struct bss_descriptor, list));
1197         }
1198
1199         ret = 0;
1200
1201 done:
1202         lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
1203         return ret;
1204 }