Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[mirror_ubuntu-artful-kernel.git] / drivers / net / wireless / libertas / scan.c

/**
  * Functions implementing wlan scan IOCTL and firmware command APIs
  *
  * IOCTL handlers as well as command preperation and response routines
  *  for sending scan commands to the firmware.
  */
#include <linux/ctype.h>
#include <linux/if.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>

#include <net/ieee80211.h>
#include <net/iw_handler.h>

#include "host.h"
#include "decl.h"
#include "dev.h"
#include "scan.h"

//! Approximate amount of data needed to pass a scan result back to iwlist
#define MAX_SCAN_CELL_SIZE  (IW_EV_ADDR_LEN             \
                             + IW_ESSID_MAX_SIZE        \
                             + IW_EV_UINT_LEN           \
                             + IW_EV_FREQ_LEN           \
                             + IW_EV_QUAL_LEN           \
                             + IW_ESSID_MAX_SIZE        \
                             + IW_EV_PARAM_LEN          \
                             + 40)      /* 40 for WPAIE */

//! Memory needed to store a max sized channel List TLV for a firmware scan
#define CHAN_TLV_MAX_SIZE  (sizeof(struct mrvlietypesheader)    \
                            + (MRVDRV_MAX_CHANNELS_PER_SCAN     \
                               * sizeof(struct chanscanparamset)))

//! Memory needed to store a max number/size SSID TLV for a firmware scan
#define SSID_TLV_MAX_SIZE  (1 * sizeof(struct mrvlietypes_ssidparamset))

//! Maximum memory needed for a wlan_scan_cmd_config with all TLVs at max
#define MAX_SCAN_CFG_ALLOC (sizeof(struct wlan_scan_cmd_config)  \
                            + sizeof(struct mrvlietypes_numprobes)   \
                            + CHAN_TLV_MAX_SIZE                 \
                            + SSID_TLV_MAX_SIZE)

//! The maximum number of channels the firmware can scan per command
#define MRVDRV_MAX_CHANNELS_PER_SCAN   14

/**
 * @brief Number of channels to scan per firmware scan command issuance.
 *
 *  Number restricted to prevent hitting the limit on the amount of scan data
 *  returned in a single firmware scan command.
 */
#define MRVDRV_CHANNELS_PER_SCAN_CMD   4

//! Scan time specified in the channel TLV for each channel for passive scans
#define MRVDRV_PASSIVE_SCAN_CHAN_TIME  100

//! Scan time specified in the channel TLV for each channel for active scans
#define MRVDRV_ACTIVE_SCAN_CHAN_TIME   100

//! Macro to enable/disable SSID checking before storing a scan table
#ifdef DISCARD_BAD_SSID
#define CHECK_SSID_IS_VALID(x) ssid_valid(&bssidEntry.ssid)
#else
#define CHECK_SSID_IS_VALID(x) 1
#endif

/**
 *  @brief Check if a scanned network compatible with the driver settings
 *
 *   WEP     WPA     WPA2    ad-hoc  encrypt                      Network
 * enabled enabled  enabled   AES     mode   privacy  WPA  WPA2  Compatible
 *    0       0        0       0      NONE      0      0    0   yes No security
 *    1       0        0       0      NONE      1      0    0   yes Static WEP
 *    0       1        0       0       x        1x     1    x   yes WPA
 *    0       0        1       0       x        1x     x    1   yes WPA2
 *    0       0        0       1      NONE      1      0    0   yes Ad-hoc AES
 *    0       0        0       0     !=NONE     1      0    0   yes Dynamic WEP
 *
 *
 *  @param adapter A pointer to wlan_adapter
 *  @param index   Index in scantable to check against current driver settings
 *  @param mode    Network mode: Infrastructure or IBSS
 *
 *  @return        Index in scantable, or error code if negative
 */
static int is_network_compatible(wlan_adapter * adapter, int index, u8 mode)
{
        ENTER();

        if (adapter->scantable[index].mode == mode) {
                if (   !adapter->secinfo.wep_enabled
                    && !adapter->secinfo.WPAenabled
                    && !adapter->secinfo.WPA2enabled
                    && adapter->scantable[index].wpa_ie[0] != WPA_IE
                    && adapter->scantable[index].rsn_ie[0] != WPA2_IE
                    && !adapter->scantable[index].privacy) {
                        /* no security */
                        LEAVE();
                        return index;
                } else if (   adapter->secinfo.wep_enabled
                           && !adapter->secinfo.WPAenabled
                           && !adapter->secinfo.WPA2enabled
                           && adapter->scantable[index].privacy) {
                        /* static WEP enabled */
                        LEAVE();
                        return index;
                } else if (   !adapter->secinfo.wep_enabled
                           && adapter->secinfo.WPAenabled
                           && !adapter->secinfo.WPA2enabled
                           && (adapter->scantable[index].wpa_ie[0] == WPA_IE)
                           /* privacy bit may NOT be set in some APs like LinkSys WRT54G
                              && adapter->scantable[index].privacy */
                    ) {
                        /* WPA enabled */
                        lbs_pr_debug(1,
                               "is_network_compatible() WPA: index=%d wpa_ie=%#x "
                               "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
                               "privacy=%#x\n", index,
                               adapter->scantable[index].wpa_ie[0],
                               adapter->scantable[index].rsn_ie[0],
                               adapter->secinfo.wep_enabled ? "e" : "d",
                               adapter->secinfo.WPAenabled ? "e" : "d",
                               adapter->secinfo.WPA2enabled ? "e" : "d",
                               adapter->scantable[index].privacy);
                        LEAVE();
                        return index;
                } else if (   !adapter->secinfo.wep_enabled
                           && !adapter->secinfo.WPAenabled
                           && adapter->secinfo.WPA2enabled
                           && (adapter->scantable[index].rsn_ie[0] == WPA2_IE)
                           /* privacy bit may NOT be set in some APs like LinkSys WRT54G
                              && adapter->scantable[index].privacy */
                    ) {
                        /* WPA2 enabled */
                        lbs_pr_debug(1,
                               "is_network_compatible() WPA2: index=%d wpa_ie=%#x "
                               "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
                               "privacy=%#x\n", index,
                               adapter->scantable[index].wpa_ie[0],
                               adapter->scantable[index].rsn_ie[0],
                               adapter->secinfo.wep_enabled ? "e" : "d",
                               adapter->secinfo.WPAenabled ? "e" : "d",
                               adapter->secinfo.WPA2enabled ? "e" : "d",
                               adapter->scantable[index].privacy);
                        LEAVE();
                        return index;
                } else if (   !adapter->secinfo.wep_enabled
                           && !adapter->secinfo.WPAenabled
                           && !adapter->secinfo.WPA2enabled
                           && (adapter->scantable[index].wpa_ie[0] != WPA_IE)
                           && (adapter->scantable[index].rsn_ie[0] != WPA2_IE)
                           && adapter->scantable[index].privacy) {
                        /* dynamic WEP enabled */
                        lbs_pr_debug(1,
                               "is_network_compatible() dynamic WEP: index=%d "
                               "wpa_ie=%#x wpa2_ie=%#x privacy=%#x\n",
                               index,
                               adapter->scantable[index].wpa_ie[0],
                               adapter->scantable[index].rsn_ie[0],
                               adapter->scantable[index].privacy);
                        LEAVE();
                        return index;
                }

                /* security doesn't match */
                lbs_pr_debug(1,
                       "is_network_compatible() FAILED: index=%d wpa_ie=%#x "
                       "wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s privacy=%#x\n",
                       index,
                       adapter->scantable[index].wpa_ie[0],
                       adapter->scantable[index].rsn_ie[0],
                       adapter->secinfo.wep_enabled ? "e" : "d",
                       adapter->secinfo.WPAenabled ? "e" : "d",
                       adapter->secinfo.WPA2enabled ? "e" : "d",
                       adapter->scantable[index].privacy);
                LEAVE();
                return -ECONNREFUSED;
        }

        /* mode doesn't match */
        LEAVE();
        return -ENETUNREACH;
}

/**
 *  @brief This function validates a SSID as being able to be printed
 *
 *  @param pssid   SSID structure to validate
 *
 *  @return        TRUE or FALSE
 */
static u8 ssid_valid(struct WLAN_802_11_SSID *pssid)
{
        int ssididx;

        for (ssididx = 0; ssididx < pssid->ssidlength; ssididx++) {
                if (!isprint(pssid->ssid[ssididx])) {
                        return 0;
                }
        }

        return 1;
}

/**
 *  @brief Post process the scan table after a new scan command has completed
 *
 *  Inspect each entry of the scan table and try to find an entry that
 *    matches our current associated/joined network from the scan.  If
 *    one is found, update the stored copy of the bssdescriptor for our
 *    current network.
 *
 *  Debug dump the current scan table contents if compiled accordingly.
 *
 *  @param priv   A pointer to wlan_private structure
 *
 *  @return       void
 */
static void wlan_scan_process_results(wlan_private * priv)
{
        wlan_adapter *adapter = priv->adapter;
        int foundcurrent;
        int i;

        foundcurrent = 0;

        if (adapter->connect_status == libertas_connected) {
                /* try to find the current BSSID in the new scan list */
                for (i = 0; i < adapter->numinscantable; i++) {
                        if (!libertas_SSID_cmp(&adapter->scantable[i].ssid,
                                     &adapter->curbssparams.ssid) &&
                            !memcmp(adapter->curbssparams.bssid,
                                    adapter->scantable[i].macaddress,
                                    ETH_ALEN)) {
                                foundcurrent = 1;
                        }
                }

                if (foundcurrent) {
                        /* Make a copy of current BSSID descriptor */
                        memcpy(&adapter->curbssparams.bssdescriptor,
                               &adapter->scantable[i],
                               sizeof(adapter->curbssparams.bssdescriptor));
                }
        }

        for (i = 0; i < adapter->numinscantable; i++) {
                lbs_pr_debug(1, "Scan:(%02d) %02x:%02x:%02x:%02x:%02x:%02x, "
                       "RSSI[%03d], SSID[%s]\n",
                       i,
                       adapter->scantable[i].macaddress[0],
                       adapter->scantable[i].macaddress[1],
                       adapter->scantable[i].macaddress[2],
                       adapter->scantable[i].macaddress[3],
                       adapter->scantable[i].macaddress[4],
                       adapter->scantable[i].macaddress[5],
                       (s32) adapter->scantable[i].rssi,
                       adapter->scantable[i].ssid.ssid);
        }
}

/**
 *  @brief Create a channel list for the driver to scan based on region info
 *
 *  Use the driver region/band information to construct a comprehensive list
 *    of channels to scan.  This routine is used for any scan that is not
 *    provided a specific channel list to scan.
 *
 *  @param priv          A pointer to wlan_private structure
 *  @param scanchanlist  Output parameter: resulting channel list to scan
 *  @param filteredscan  Flag indicating whether or not a BSSID or SSID filter
 *                       is being sent in the command to firmware.  Used to
 *                       increase the number of channels sent in a scan
 *                       command and to disable the firmware channel scan
 *                       filter.
 *
 *  @return              void
 */
static void wlan_scan_create_channel_list(wlan_private * priv,
                                          struct chanscanparamset * scanchanlist,
                                          u8 filteredscan)
{

        wlan_adapter *adapter = priv->adapter;
        struct region_channel *scanregion;
        struct chan_freq_power *cfp;
        int rgnidx;
        int chanidx;
        int nextchan;
        u8 scantype;

        chanidx = 0;

        /* Set the default scan type to the user specified type, will later
         *   be changed to passive on a per channel basis if restricted by
         *   regulatory requirements (11d or 11h)
         */
        scantype = adapter->scantype;

        for (rgnidx = 0; rgnidx < ARRAY_SIZE(adapter->region_channel); rgnidx++) {
                if (priv->adapter->enable11d &&
                    adapter->connect_status != libertas_connected) {
                        /* Scan all the supported chan for the first scan */
                        if (!adapter->universal_channel[rgnidx].valid)
                                continue;
                        scanregion = &adapter->universal_channel[rgnidx];

                        /* clear the parsed_region_chan for the first scan */
                        memset(&adapter->parsed_region_chan, 0x00,
                               sizeof(adapter->parsed_region_chan));
                } else {
                        if (!adapter->region_channel[rgnidx].valid)
                                continue;
                        scanregion = &adapter->region_channel[rgnidx];
                }

                for (nextchan = 0;
                     nextchan < scanregion->nrcfp; nextchan++, chanidx++) {

                        cfp = scanregion->CFP + nextchan;

                        if (priv->adapter->enable11d) {
                                scantype =
                                    libertas_get_scan_type_11d(cfp->channel,
                                                           &adapter->
                                                           parsed_region_chan);
                        }

                        switch (scanregion->band) {
                        case BAND_B:
                        case BAND_G:
                        default:
                                scanchanlist[chanidx].radiotype =
                                    cmd_scan_radio_type_bg;
                                break;
                        }

                        if (scantype == cmd_scan_type_passive) {
                                scanchanlist[chanidx].maxscantime =
                                    cpu_to_le16
                                    (MRVDRV_PASSIVE_SCAN_CHAN_TIME);
                                scanchanlist[chanidx].chanscanmode.passivescan =
                                    1;
                        } else {
                                scanchanlist[chanidx].maxscantime =
                                    cpu_to_le16
                                    (MRVDRV_ACTIVE_SCAN_CHAN_TIME);
                                scanchanlist[chanidx].chanscanmode.passivescan =
                                    0;
                        }

                        scanchanlist[chanidx].channumber = cfp->channel;

                        if (filteredscan) {
                                scanchanlist[chanidx].chanscanmode.
                                    disablechanfilt = 1;
                        }
                }
        }
}

/**
 *  @brief Construct a wlan_scan_cmd_config structure to use in issue scan cmds
 *
 *  Application layer or other functions can invoke wlan_scan_networks
 *    with a scan configuration supplied in a wlan_ioctl_user_scan_cfg struct.
 *    This structure is used as the basis of one or many wlan_scan_cmd_config
 *    commands that are sent to the command processing module and sent to
 *    firmware.
 *
 *  Create a wlan_scan_cmd_config based on the following user supplied
 *    parameters (if present):
 *             - SSID filter
 *             - BSSID filter
 *             - Number of Probes to be sent
 *             - channel list
 *
 *  If the SSID or BSSID filter is not present, disable/clear the filter.
 *  If the number of probes is not set, use the adapter default setting
 *  Qualify the channel
 *
 *  @param priv             A pointer to wlan_private structure
 *  @param puserscanin      NULL or pointer to scan configuration parameters
 *  @param ppchantlvout     Output parameter: Pointer to the start of the
 *                          channel TLV portion of the output scan config
 *  @param pscanchanlist    Output parameter: Pointer to the resulting channel
 *                          list to scan
 *  @param pmaxchanperscan  Output parameter: Number of channels to scan for
 *                          each issuance of the firmware scan command
 *  @param pfilteredscan    Output parameter: Flag indicating whether or not
 *                          a BSSID or SSID filter is being sent in the
 *                          command to firmware.  Used to increase the number
 *                          of channels sent in a scan command and to
 *                          disable the firmware channel scan filter.
 *  @param pscancurrentonly Output parameter: Flag indicating whether or not
 *                          we are only scanning our current active channel
 *
 *  @return                 resulting scan configuration
 */
static struct wlan_scan_cmd_config *
wlan_scan_setup_scan_config(wlan_private * priv,
                            const struct wlan_ioctl_user_scan_cfg * puserscanin,
                            struct mrvlietypes_chanlistparamset ** ppchantlvout,
                            struct chanscanparamset * pscanchanlist,
                            int *pmaxchanperscan,
                            u8 * pfilteredscan,
                            u8 * pscancurrentonly)
{
        wlan_adapter *adapter = priv->adapter;
        const u8 zeromac[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
        struct mrvlietypes_numprobes *pnumprobestlv;
        struct mrvlietypes_ssidparamset *pssidtlv;
        struct wlan_scan_cmd_config * pscancfgout = NULL;
        u8 *ptlvpos;
        u16 numprobes;
        u16 ssidlen;
        int chanidx;
        int scantype;
        int scandur;
        int channel;
        int radiotype;

        pscancfgout = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL);
        if (pscancfgout == NULL)
                goto out;

        /* The tlvbufferlen is calculated for each scan command.  The TLVs added
         *   in this routine will be preserved since the routine that sends
         *   the command will append channelTLVs at *ppchantlvout.  The difference
         *   between the *ppchantlvout and the tlvbuffer start will be used
         *   to calculate the size of anything we add in this routine.
         */
        pscancfgout->tlvbufferlen = 0;

        /* Running tlv pointer.  Assigned to ppchantlvout at end of function
         *  so later routines know where channels can be added to the command buf
         */
        ptlvpos = pscancfgout->tlvbuffer;

        /*
         * Set the initial scan paramters for progressive scanning.  If a specific
         *   BSSID or SSID is used, the number of channels in the scan command
         *   will be increased to the absolute maximum
         */
        *pmaxchanperscan = MRVDRV_CHANNELS_PER_SCAN_CMD;

        /* Initialize the scan as un-filtered by firmware, set to TRUE below if
         *   a SSID or BSSID filter is sent in the command
         */
        *pfilteredscan = 0;

        /* Initialize the scan as not being only on the current channel.  If
         *   the channel list is customized, only contains one channel, and
         *   is the active channel, this is set true and data flow is not halted.
         */
        *pscancurrentonly = 0;

        if (puserscanin) {

                /* Set the bss type scan filter, use adapter setting if unset */
                pscancfgout->bsstype =
                    (puserscanin->bsstype ? puserscanin->bsstype : adapter->
                     scanmode);

                /* Set the number of probes to send, use adapter setting if unset */
                numprobes = (puserscanin->numprobes ? puserscanin->numprobes :
                             adapter->scanprobes);

                /*
                 * Set the BSSID filter to the incoming configuration,
                 *   if non-zero.  If not set, it will remain disabled (all zeros).
                 */
                memcpy(pscancfgout->specificBSSID,
                       puserscanin->specificBSSID,
                       sizeof(pscancfgout->specificBSSID));

                ssidlen = strlen(puserscanin->specificSSID);

                if (ssidlen) {
                        pssidtlv =
                            (struct mrvlietypes_ssidparamset *) pscancfgout->
                            tlvbuffer;
                        pssidtlv->header.type = cpu_to_le16(TLV_TYPE_SSID);
                        pssidtlv->header.len = cpu_to_le16(ssidlen);
                        memcpy(pssidtlv->ssid, puserscanin->specificSSID,
                               ssidlen);
                        ptlvpos += sizeof(pssidtlv->header) + ssidlen;
                }

                /*
                 *  The default number of channels sent in the command is low to
                 *    ensure the response buffer from the firmware does not truncate
                 *    scan results.  That is not an issue with an SSID or BSSID
                 *    filter applied to the scan results in the firmware.
                 */
                if (ssidlen || (memcmp(pscancfgout->specificBSSID,
                                       &zeromac, sizeof(zeromac)) != 0)) {
                        *pmaxchanperscan = MRVDRV_MAX_CHANNELS_PER_SCAN;
                        *pfilteredscan = 1;
                }
        } else {
                pscancfgout->bsstype = adapter->scanmode;
                numprobes = adapter->scanprobes;
        }

        /* If the input config or adapter has the number of Probes set, add tlv */
        if (numprobes) {
                pnumprobestlv = (struct mrvlietypes_numprobes *) ptlvpos;
                pnumprobestlv->header.type =
                    cpu_to_le16(TLV_TYPE_NUMPROBES);
                pnumprobestlv->header.len = sizeof(pnumprobestlv->numprobes);
                pnumprobestlv->numprobes = cpu_to_le16(numprobes);

                ptlvpos +=
                    sizeof(pnumprobestlv->header) + pnumprobestlv->header.len;

                pnumprobestlv->header.len =
                    cpu_to_le16(pnumprobestlv->header.len);
        }

        /*
         * Set the output for the channel TLV to the address in the tlv buffer
         *   past any TLVs that were added in this fuction (SSID, numprobes).
         *   channel TLVs will be added past this for each scan command, preserving
         *   the TLVs that were previously added.
         */
        *ppchantlvout = (struct mrvlietypes_chanlistparamset *) ptlvpos;

        if (puserscanin && puserscanin->chanlist[0].channumber) {

                lbs_pr_debug(1, "Scan: Using supplied channel list\n");

                for (chanidx = 0;
                     chanidx < WLAN_IOCTL_USER_SCAN_CHAN_MAX
                     && puserscanin->chanlist[chanidx].channumber; chanidx++) {

                        channel = puserscanin->chanlist[chanidx].channumber;
                        (pscanchanlist + chanidx)->channumber = channel;

                        radiotype = puserscanin->chanlist[chanidx].radiotype;
                        (pscanchanlist + chanidx)->radiotype = radiotype;

                        scantype = puserscanin->chanlist[chanidx].scantype;

                        if (scantype == cmd_scan_type_passive) {
                                (pscanchanlist +
                                 chanidx)->chanscanmode.passivescan = 1;
                        } else {
                                (pscanchanlist +
                                 chanidx)->chanscanmode.passivescan = 0;
                        }

                        if (puserscanin->chanlist[chanidx].scantime) {
                                scandur =
                                    puserscanin->chanlist[chanidx].scantime;
                        } else {
                                if (scantype == cmd_scan_type_passive) {
                                        scandur = MRVDRV_PASSIVE_SCAN_CHAN_TIME;
                                } else {
                                        scandur = MRVDRV_ACTIVE_SCAN_CHAN_TIME;
                                }
                        }

                        (pscanchanlist + chanidx)->minscantime =
                            cpu_to_le16(scandur);
                        (pscanchanlist + chanidx)->maxscantime =
                            cpu_to_le16(scandur);
                }

                /* Check if we are only scanning the current channel */
                if ((chanidx == 1) && (puserscanin->chanlist[0].channumber
                                       ==
                                       priv->adapter->curbssparams.channel)) {
                        *pscancurrentonly = 1;
                        lbs_pr_debug(1, "Scan: Scanning current channel only");
                }

        } else {
                lbs_pr_debug(1, "Scan: Creating full region channel list\n");
                wlan_scan_create_channel_list(priv, pscanchanlist,
                                              *pfilteredscan);
        }

out:
        return pscancfgout;
}

/**
 *  @brief Construct and send multiple scan config commands to the firmware
 *
 *  Previous routines have created a wlan_scan_cmd_config with any requested
 *   TLVs.  This function splits the channel TLV into maxchanperscan lists
 *   and sends the portion of the channel TLV along with the other TLVs
 *   to the wlan_cmd routines for execution in the firmware.
 *
 *  @param priv            A pointer to wlan_private structure
 *  @param maxchanperscan  Maximum number channels to be included in each
 *                         scan command sent to firmware
 *  @param filteredscan    Flag indicating whether or not a BSSID or SSID
 *                         filter is being used for the firmware command
 *                         scan command sent to firmware
 *  @param pscancfgout     Scan configuration used for this scan.
 *  @param pchantlvout     Pointer in the pscancfgout where the channel TLV
 *                         should start.  This is past any other TLVs that
 *                         must be sent down in each firmware command.
 *  @param pscanchanlist   List of channels to scan in maxchanperscan segments
 *
 *  @return                0 or error return otherwise
 */
static int wlan_scan_channel_list(wlan_private * priv,
                                  int maxchanperscan,
                                  u8 filteredscan,
                                  struct wlan_scan_cmd_config * pscancfgout,
                                  struct mrvlietypes_chanlistparamset * pchantlvout,
                                  struct chanscanparamset * pscanchanlist)
{
        struct chanscanparamset *ptmpchan;
        struct chanscanparamset *pstartchan;
        u8 scanband;
        int doneearly;
        int tlvidx;
        int ret = 0;

        ENTER();

        if (pscancfgout == 0 || pchantlvout == 0 || pscanchanlist == 0) {
                lbs_pr_debug(1, "Scan: Null detect: %p, %p, %p\n",
                       pscancfgout, pchantlvout, pscanchanlist);
                return -1;
        }

        pchantlvout->header.type = cpu_to_le16(TLV_TYPE_CHANLIST);

        /* Set the temp channel struct pointer to the start of the desired list */
        ptmpchan = pscanchanlist;

        /* Loop through the desired channel list, sending a new firmware scan
         *   commands for each maxchanperscan channels (or for 1,6,11 individually
         *   if configured accordingly)
         */
        while (ptmpchan->channumber) {

                tlvidx = 0;
                pchantlvout->header.len = 0;
                scanband = ptmpchan->radiotype;
                pstartchan = ptmpchan;
                doneearly = 0;

                /* Construct the channel TLV for the scan command.  Continue to
                 *  insert channel TLVs until:
                 *    - the tlvidx hits the maximum configured per scan command
                 *    - the next channel to insert is 0 (end of desired channel list)
                 *    - doneearly is set (controlling individual scanning of 1,6,11)
                 */
                while (tlvidx < maxchanperscan && ptmpchan->channumber
                       && !doneearly) {

            lbs_pr_debug(1,
                    "Scan: Chan(%3d), Radio(%d), mode(%d,%d), Dur(%d)\n",
                ptmpchan->channumber, ptmpchan->radiotype,
                ptmpchan->chanscanmode.passivescan,
                ptmpchan->chanscanmode.disablechanfilt,
                ptmpchan->maxscantime);

                        /* Copy the current channel TLV to the command being prepared */
                        memcpy(pchantlvout->chanscanparam + tlvidx,
                               ptmpchan, sizeof(pchantlvout->chanscanparam));

                        /* Increment the TLV header length by the size appended */
                        pchantlvout->header.len +=
                            sizeof(pchantlvout->chanscanparam);

                        /*
                         *  The tlv buffer length is set to the number of bytes of the
                         *    between the channel tlv pointer and the start of the
                         *    tlv buffer.  This compensates for any TLVs that were appended
                         *    before the channel list.
                         */
                        pscancfgout->tlvbufferlen = ((u8 *) pchantlvout
                                                     - pscancfgout->tlvbuffer);

                        /*  Add the size of the channel tlv header and the data length */
                        pscancfgout->tlvbufferlen +=
                            (sizeof(pchantlvout->header)
                             + pchantlvout->header.len);

                        /* Increment the index to the channel tlv we are constructing */
                        tlvidx++;

                        doneearly = 0;

                        /* Stop the loop if the *current* channel is in the 1,6,11 set
                         *   and we are not filtering on a BSSID or SSID.
                         */
                        if (!filteredscan && (ptmpchan->channumber == 1
                                              || ptmpchan->channumber == 6
                                              || ptmpchan->channumber == 11)) {
                                doneearly = 1;
                        }

                        /* Increment the tmp pointer to the next channel to be scanned */
                        ptmpchan++;

                        /* Stop the loop if the *next* channel is in the 1,6,11 set.
                         *  This will cause it to be the only channel scanned on the next
                         *  interation
                         */
                        if (!filteredscan && (ptmpchan->channumber == 1
                                              || ptmpchan->channumber == 6
                                              || ptmpchan->channumber == 11)) {
                                doneearly = 1;
                        }
                }

                /* Send the scan command to the firmware with the specified cfg */
                ret = libertas_prepare_and_send_command(priv, cmd_802_11_scan, 0,
                                            0, 0, pscancfgout);
        }

        LEAVE();
        return ret;
}

/**
 *  @brief Internal function used to start a scan based on an input config
 *
 *  Use the input user scan configuration information when provided in
 *    order to send the appropriate scan commands to firmware to populate or
 *    update the internal driver scan table
 *
 *  @param priv          A pointer to wlan_private structure
 *  @param puserscanin   Pointer to the input configuration for the requested
 *                       scan.
 *
 *  @return              0 or < 0 if error
 */
int wlan_scan_networks(wlan_private * priv,
                              const struct wlan_ioctl_user_scan_cfg * puserscanin)
{
        wlan_adapter *adapter = priv->adapter;
        struct mrvlietypes_chanlistparamset *pchantlvout;
        struct chanscanparamset * scan_chan_list = NULL;
        struct wlan_scan_cmd_config * scan_cfg = NULL;
        u8 keeppreviousscan;
        u8 filteredscan;
        u8 scancurrentchanonly;
        int maxchanperscan;
        int ret;

        ENTER();

        scan_chan_list = kzalloc(sizeof(struct chanscanparamset) *
                                WLAN_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL);
        if (scan_chan_list == NULL) {
                ret = -ENOMEM;
                goto out;
        }

        scan_cfg = wlan_scan_setup_scan_config(priv,
                                               puserscanin,
                                               &pchantlvout,
                                               scan_chan_list,
                                               &maxchanperscan,
                                               &filteredscan,
                                               &scancurrentchanonly);
        if (scan_cfg == NULL) {
                ret = -ENOMEM;
                goto out;
        }

        keeppreviousscan = 0;

        if (puserscanin) {
                keeppreviousscan = puserscanin->keeppreviousscan;
        }

        if (!keeppreviousscan) {
                memset(adapter->scantable, 0x00,
                       sizeof(struct bss_descriptor) * MRVDRV_MAX_BSSID_LIST);
                adapter->numinscantable = 0;
        }

        /* Keep the data path active if we are only scanning our current channel */
        if (!scancurrentchanonly) {
                netif_stop_queue(priv->wlan_dev.netdev);
                netif_carrier_off(priv->wlan_dev.netdev);
        }

        ret = wlan_scan_channel_list(priv,
                                     maxchanperscan,
                                     filteredscan,
                                     scan_cfg,
                                     pchantlvout,
                                     scan_chan_list);

        /*  Process the resulting scan table:
         *    - Remove any bad ssids
         *    - Update our current BSS information from scan data
         */
        wlan_scan_process_results(priv);

        if (priv->adapter->connect_status == libertas_connected) {
                netif_carrier_on(priv->wlan_dev.netdev);
                netif_wake_queue(priv->wlan_dev.netdev);
        }

out:
        if (scan_cfg)
                kfree(scan_cfg);

        if (scan_chan_list)
                kfree(scan_chan_list);

        LEAVE();
        return ret;
}

/**
 *  @brief Inspect the scan response buffer for pointers to expected TLVs
 *
 *  TLVs can be included at the end of the scan response BSS information.
 *    Parse the data in the buffer for pointers to TLVs that can potentially
 *    be passed back in the response
 *
 *  @param ptlv        Pointer to the start of the TLV buffer to parse
 *  @param tlvbufsize  size of the TLV buffer
 *  @param ptsftlv     Output parameter: Pointer to the TSF TLV if found
 *
 *  @return            void
 */
static
void wlan_ret_802_11_scan_get_tlv_ptrs(struct mrvlietypes_data * ptlv,
                                       int tlvbufsize,
                                       struct mrvlietypes_tsftimestamp ** ptsftlv)
{
        struct mrvlietypes_data *pcurrenttlv;
        int tlvbufleft;
        u16 tlvtype;
        u16 tlvlen;

        pcurrenttlv = ptlv;
        tlvbufleft = tlvbufsize;
        *ptsftlv = NULL;

        lbs_pr_debug(1, "SCAN_RESP: tlvbufsize = %d\n", tlvbufsize);
        lbs_dbg_hex("SCAN_RESP: TLV Buf", (u8 *) ptlv, tlvbufsize);

        while (tlvbufleft >= sizeof(struct mrvlietypesheader)) {
                tlvtype = le16_to_cpu(pcurrenttlv->header.type);
                tlvlen = le16_to_cpu(pcurrenttlv->header.len);

                switch (tlvtype) {
                case TLV_TYPE_TSFTIMESTAMP:
                        *ptsftlv = (struct mrvlietypes_tsftimestamp *) pcurrenttlv;
                        break;

                default:
                        lbs_pr_debug(1, "SCAN_RESP: Unhandled TLV = %d\n",
                               tlvtype);
                        /* Give up, this seems corrupted */
                        return;
                }               /* switch */

                tlvbufleft -= (sizeof(ptlv->header) + tlvlen);
                pcurrenttlv =
                    (struct mrvlietypes_data *) (pcurrenttlv->Data + tlvlen);
        }                       /* while */
}

/**
 *  @brief Interpret a BSS scan response returned from the firmware
 *
 *  Parse the various fixed fields and IEs passed back for a a BSS probe
 *   response or beacon from the scan command.  Record information as needed
 *   in the scan table struct bss_descriptor for that entry.
 *
 *  @param pBSSIDEntry  Output parameter: Pointer to the BSS Entry
 *
 *  @return             0 or -1
 */
static int InterpretBSSDescriptionWithIE(struct bss_descriptor * pBSSEntry,
                                         u8 ** pbeaconinfo, int *bytesleft)
{
        enum ieeetypes_elementid elemID;
        struct ieeetypes_fhparamset *pFH;
        struct ieeetypes_dsparamset *pDS;
        struct ieeetypes_cfparamset *pCF;
        struct ieeetypes_ibssparamset *pibss;
        struct ieeetypes_capinfo *pcap;
        struct WLAN_802_11_FIXED_IEs fixedie;
        u8 *pcurrentptr;
        u8 *pRate;
        u8 elemlen;
        u8 bytestocopy;
        u8 ratesize;
        u16 beaconsize;
        u8 founddatarateie;
        int bytesleftforcurrentbeacon;

        struct IE_WPA *pIe;
        const u8 oui01[4] = { 0x00, 0x50, 0xf2, 0x01 };

        struct ieeetypes_countryinfoset *pcountryinfo;

        ENTER();

        founddatarateie = 0;
        ratesize = 0;
        beaconsize = 0;

        if (*bytesleft >= sizeof(beaconsize)) {
                /* Extract & convert beacon size from the command buffer */
                memcpy(&beaconsize, *pbeaconinfo, sizeof(beaconsize));
                beaconsize = le16_to_cpu(beaconsize);
                *bytesleft -= sizeof(beaconsize);
                *pbeaconinfo += sizeof(beaconsize);
        }

        if (beaconsize == 0 || beaconsize > *bytesleft) {

                *pbeaconinfo += *bytesleft;
                *bytesleft = 0;

                return -1;
        }

        /* Initialize the current working beacon pointer for this BSS iteration */
        pcurrentptr = *pbeaconinfo;

        /* Advance the return beacon pointer past the current beacon */
        *pbeaconinfo += beaconsize;
        *bytesleft -= beaconsize;

        bytesleftforcurrentbeacon = beaconsize;

        memcpy(pBSSEntry->macaddress, pcurrentptr, ETH_ALEN);
        lbs_pr_debug(1, "InterpretIE: AP MAC Addr-%x:%x:%x:%x:%x:%x\n",
               pBSSEntry->macaddress[0], pBSSEntry->macaddress[1],
               pBSSEntry->macaddress[2], pBSSEntry->macaddress[3],
               pBSSEntry->macaddress[4], pBSSEntry->macaddress[5]);

        pcurrentptr += ETH_ALEN;
        bytesleftforcurrentbeacon -= ETH_ALEN;

        if (bytesleftforcurrentbeacon < 12) {
                lbs_pr_debug(1, "InterpretIE: Not enough bytes left\n");
                return -1;
        }

        /*
         * next 4 fields are RSSI, time stamp, beacon interval,
         *   and capability information
         */

        /* RSSI is 1 byte long */
        pBSSEntry->rssi = le32_to_cpu((long)(*pcurrentptr));
        lbs_pr_debug(1, "InterpretIE: RSSI=%02X\n", *pcurrentptr);
        pcurrentptr += 1;
        bytesleftforcurrentbeacon -= 1;

        /* time stamp is 8 bytes long */
        memcpy(fixedie.timestamp, pcurrentptr, 8);
        memcpy(pBSSEntry->timestamp, pcurrentptr, 8);
        pcurrentptr += 8;
        bytesleftforcurrentbeacon -= 8;

        /* beacon interval is 2 bytes long */
        memcpy(&fixedie.beaconinterval, pcurrentptr, 2);
        pBSSEntry->beaconperiod = le16_to_cpu(fixedie.beaconinterval);
        pcurrentptr += 2;
        bytesleftforcurrentbeacon -= 2;

        /* capability information is 2 bytes long */
        memcpy(&fixedie.capabilities, pcurrentptr, 2);
        lbs_pr_debug(1, "InterpretIE: fixedie.capabilities=0x%X\n",
               fixedie.capabilities);
        fixedie.capabilities = le16_to_cpu(fixedie.capabilities);
        pcap = (struct ieeetypes_capinfo *) & fixedie.capabilities;
        memcpy(&pBSSEntry->cap, pcap, sizeof(struct ieeetypes_capinfo));
        pcurrentptr += 2;
        bytesleftforcurrentbeacon -= 2;

        /* rest of the current buffer are IE's */
        lbs_pr_debug(1, "InterpretIE: IElength for this AP = %d\n",
               bytesleftforcurrentbeacon);

        lbs_dbg_hex("InterpretIE: IE info", (u8 *) pcurrentptr,
                bytesleftforcurrentbeacon);

        if (pcap->privacy) {
                lbs_pr_debug(1, "InterpretIE: AP WEP enabled\n");
                pBSSEntry->privacy = wlan802_11privfilter8021xWEP;
        } else {
                pBSSEntry->privacy = wlan802_11privfilteracceptall;
        }

        if (pcap->ibss == 1) {
                pBSSEntry->mode = IW_MODE_ADHOC;
        } else {
                pBSSEntry->mode = IW_MODE_INFRA;
        }

        /* process variable IE */
        while (bytesleftforcurrentbeacon >= 2) {
                elemID = (enum ieeetypes_elementid) (*((u8 *) pcurrentptr));
                elemlen = *((u8 *) pcurrentptr + 1);

                if (bytesleftforcurrentbeacon < elemlen) {
                        lbs_pr_debug(1, "InterpretIE: error in processing IE, "
                               "bytes left < IE length\n");
                        bytesleftforcurrentbeacon = 0;
                        continue;
                }

                switch (elemID) {

                case SSID:
                        pBSSEntry->ssid.ssidlength = elemlen;
                        memcpy(pBSSEntry->ssid.ssid, (pcurrentptr + 2),
                               elemlen);
                        lbs_pr_debug(1, "ssid: %32s", pBSSEntry->ssid.ssid);
                        break;

                case SUPPORTED_RATES:
                        memcpy(pBSSEntry->datarates, (pcurrentptr + 2),
                               elemlen);
                        memmove(pBSSEntry->libertas_supported_rates, (pcurrentptr + 2),
                                elemlen);
                        ratesize = elemlen;
                        founddatarateie = 1;
                        break;

                case EXTRA_IE:
                        lbs_pr_debug(1, "InterpretIE: EXTRA_IE Found!\n");
                        pBSSEntry->extra_ie = 1;
                        break;

                case FH_PARAM_SET:
                        pFH = (struct ieeetypes_fhparamset *) pcurrentptr;
                        memmove(&pBSSEntry->phyparamset.fhparamset, pFH,
                                sizeof(struct ieeetypes_fhparamset));
                        pBSSEntry->phyparamset.fhparamset.dwelltime
                            =
                            le16_to_cpu(pBSSEntry->phyparamset.fhparamset.
                                             dwelltime);
                        break;

                case DS_PARAM_SET:
                        pDS = (struct ieeetypes_dsparamset *) pcurrentptr;

                        pBSSEntry->channel = pDS->currentchan;

                        memcpy(&pBSSEntry->phyparamset.dsparamset, pDS,
                               sizeof(struct ieeetypes_dsparamset));
                        break;

                case CF_PARAM_SET:
                        pCF = (struct ieeetypes_cfparamset *) pcurrentptr;

                        memcpy(&pBSSEntry->ssparamset.cfparamset, pCF,
                               sizeof(struct ieeetypes_cfparamset));
                        break;

                case IBSS_PARAM_SET:
                        pibss = (struct ieeetypes_ibssparamset *) pcurrentptr;
                        pBSSEntry->atimwindow =
                            le32_to_cpu(pibss->atimwindow);

                        memmove(&pBSSEntry->ssparamset.ibssparamset, pibss,
                                sizeof(struct ieeetypes_ibssparamset));

                        pBSSEntry->ssparamset.ibssparamset.atimwindow
                            =
                            le16_to_cpu(pBSSEntry->ssparamset.ibssparamset.
                                             atimwindow);
                        break;

                        /* Handle Country Info IE */
                case COUNTRY_INFO:
                        pcountryinfo =
                            (struct ieeetypes_countryinfoset *) pcurrentptr;

                        if (pcountryinfo->len <
                            sizeof(pcountryinfo->countrycode)
                            || pcountryinfo->len > 254) {
                                lbs_pr_debug(1, "InterpretIE: 11D- Err "
                                       "CountryInfo len =%d min=%zd max=254\n",
                                       pcountryinfo->len,
                                       sizeof(pcountryinfo->countrycode));
                                LEAVE();
                                return -1;
                        }

                        memcpy(&pBSSEntry->countryinfo,
                               pcountryinfo, pcountryinfo->len + 2);
                        lbs_dbg_hex("InterpretIE: 11D- CountryInfo:",
                                (u8 *) pcountryinfo,
                                (u32) (pcountryinfo->len + 2));
                        break;

                case EXTENDED_SUPPORTED_RATES:
                        /*
                         * only process extended supported rate
                         * if data rate is already found.
                         * data rate IE should come before
                         * extended supported rate IE
                         */
                        if (founddatarateie) {
                                if ((elemlen + ratesize) > WLAN_SUPPORTED_RATES) {
                                        bytestocopy =
                                            (WLAN_SUPPORTED_RATES - ratesize);
                                } else {
                                        bytestocopy = elemlen;
                                }

                                pRate = (u8 *) pBSSEntry->datarates;
                                pRate += ratesize;
                                memmove(pRate, (pcurrentptr + 2), bytestocopy);

                                pRate = (u8 *) pBSSEntry->libertas_supported_rates;

                                pRate += ratesize;
                                memmove(pRate, (pcurrentptr + 2), bytestocopy);
                        }
                        break;

                case VENDOR_SPECIFIC_221:
#define IE_ID_LEN_FIELDS_BYTES 2
                        pIe = (struct IE_WPA *)pcurrentptr;

                        if (memcmp(pIe->oui, oui01, sizeof(oui01)))
                                break;

                        pBSSEntry->wpa_ie_len = min_t(size_t,
                                elemlen + IE_ID_LEN_FIELDS_BYTES,
                                sizeof(pBSSEntry->wpa_ie));
                        memcpy(pBSSEntry->wpa_ie, pcurrentptr,
                                pBSSEntry->wpa_ie_len);
                        lbs_dbg_hex("InterpretIE: Resp WPA_IE",
                                pBSSEntry->wpa_ie, elemlen);
                        break;
                case WPA2_IE:
                        pIe = (struct IE_WPA *)pcurrentptr;

                        pBSSEntry->rsn_ie_len = min_t(size_t,
                                elemlen + IE_ID_LEN_FIELDS_BYTES,
                                sizeof(pBSSEntry->rsn_ie));
                        memcpy(pBSSEntry->rsn_ie, pcurrentptr,
                                pBSSEntry->rsn_ie_len);
                        lbs_dbg_hex("InterpretIE: Resp WPA2_IE",
                                pBSSEntry->rsn_ie, elemlen);
                        break;
                case TIM:
                        break;

                case CHALLENGE_TEXT:
                        break;
                }

                pcurrentptr += elemlen + 2;

                /* need to account for IE ID and IE len */
                bytesleftforcurrentbeacon -= (elemlen + 2);

        }                       /* while (bytesleftforcurrentbeacon > 2) */

        return 0;
}

/**
 *  @brief Compare two SSIDs
 *
 *  @param ssid1    A pointer to ssid to compare
 *  @param ssid2    A pointer to ssid to compare
 *
 *  @return         0--ssid is same, otherwise is different
 */
int libertas_SSID_cmp(struct WLAN_802_11_SSID *ssid1, struct WLAN_802_11_SSID *ssid2)
{
        if (!ssid1 || !ssid2)
                return -1;

        if (ssid1->ssidlength != ssid2->ssidlength)
                return -1;

        return memcmp(ssid1->ssid, ssid2->ssid, ssid1->ssidlength);
}

/**
 *  @brief This function finds a specific compatible BSSID in the scan list
 *
 *  @param adapter  A pointer to wlan_adapter
 *  @param bssid    BSSID to find in the scan list
 *  @param mode     Network mode: Infrastructure or IBSS
 *
 *  @return         index in BSSID list, or error return code (< 0)
 */
int libertas_find_BSSID_in_list(wlan_adapter * adapter, u8 * bssid, u8 mode)
{
        int ret = -ENETUNREACH;
        int i;

        if (!bssid)
                return -EFAULT;

        lbs_pr_debug(1, "FindBSSID: Num of BSSIDs = %d\n",
               adapter->numinscantable);

        /* Look through the scan table for a compatible match. The ret return
         *   variable will be equal to the index in the scan table (greater
         *   than zero) if the network is compatible.  The loop will continue
         *   past a matched bssid that is not compatible in case there is an
         *   AP with multiple SSIDs assigned to the same BSSID
         */
        for (i = 0; ret < 0 && i < adapter->numinscantable; i++) {
                if (!memcmp(adapter->scantable[i].macaddress, bssid, ETH_ALEN)) {
                        switch (mode) {
                        case IW_MODE_INFRA:
                        case IW_MODE_ADHOC:
                                ret = is_network_compatible(adapter, i, mode);
                                break;
                        default:
                                ret = i;
                                break;
                        }
                }
        }

        return ret;
}

/**
 *  @brief This function finds ssid in ssid list.
 *
 *  @param adapter  A pointer to wlan_adapter
 *  @param ssid     SSID to find in the list
 *  @param bssid    BSSID to qualify the SSID selection (if provided)
 *  @param mode     Network mode: Infrastructure or IBSS
 *
 *  @return         index in BSSID list
 */
int libertas_find_SSID_in_list(wlan_adapter * adapter,
                   struct WLAN_802_11_SSID *ssid, u8 * bssid, u8 mode)
{
        int net = -ENETUNREACH;
        u8 bestrssi = 0;
        int i;
        int j;

        lbs_pr_debug(1, "Num of Entries in Table = %d\n", adapter->numinscantable);

        for (i = 0; i < adapter->numinscantable; i++) {
                if (!libertas_SSID_cmp(&adapter->scantable[i].ssid, ssid) &&
                    (!bssid ||
                     !memcmp(adapter->scantable[i].
                             macaddress, bssid, ETH_ALEN))) {
                        switch (mode) {
                        case IW_MODE_INFRA:
                        case IW_MODE_ADHOC:
                                j = is_network_compatible(adapter, i, mode);

                                if (j >= 0) {
                                        if (bssid) {
                                                return i;
                                        }

                                        if (SCAN_RSSI
                                            (adapter->scantable[i].rssi)
                                            > bestrssi) {
                                                bestrssi =
                                                    SCAN_RSSI(adapter->
                                                              scantable[i].
                                                              rssi);
                                                net = i;
                                        }
                                } else {
                                        if (net == -ENETUNREACH) {
                                                net = j;
                                        }
                                }
                                break;
                        case IW_MODE_AUTO:
                        default:
                                if (SCAN_RSSI(adapter->scantable[i].rssi)
                                    > bestrssi) {
                                        bestrssi =
                                            SCAN_RSSI(adapter->scantable[i].
                                                      rssi);
                                        net = i;
                                }
                                break;
                        }
                }
        }

        return net;
}

/**
 *  @brief This function finds the best SSID in the Scan List
 *
 *  Search the scan table for the best SSID that also matches the current
 *   adapter network preference (infrastructure or adhoc)
 *
 *  @param adapter  A pointer to wlan_adapter
 *
 *  @return         index in BSSID list
 */
int libertas_find_best_SSID_in_list(wlan_adapter * adapter, u8 mode)
{
        int bestnet = -ENETUNREACH;
        u8 bestrssi = 0;
        int i;

        ENTER();

        lbs_pr_debug(1, "Num of BSSIDs = %d\n", adapter->numinscantable);

        for (i = 0; i < adapter->numinscantable; i++) {
                switch (mode) {
                case IW_MODE_INFRA:
                case IW_MODE_ADHOC:
                        if (is_network_compatible(adapter, i, mode) >= 0) {
                                if (SCAN_RSSI(adapter->scantable[i].rssi) >
                                    bestrssi) {
                                        bestrssi =
                                            SCAN_RSSI(adapter->scantable[i].
                                                      rssi);
                                        bestnet = i;
                                }
                        }
                        break;
                case IW_MODE_AUTO:
                default:
                        if (SCAN_RSSI(adapter->scantable[i].rssi) > bestrssi) {
                                bestrssi =
                                    SCAN_RSSI(adapter->scantable[i].rssi);
                                bestnet = i;
                        }
                        break;
                }
        }

        LEAVE();
        return bestnet;
}

/**
 *  @brief Find the AP with specific ssid in the scan list
 *
 *  @param priv         A pointer to wlan_private structure
 *  @param pSSID        A pointer to AP's ssid
 *
 *  @return             0--success, otherwise--fail
 */
int libertas_find_best_network_SSID(wlan_private * priv,
                                    struct WLAN_802_11_SSID *pSSID,
                                    u8 preferred_mode, u8 *out_mode)
{
        wlan_adapter *adapter = priv->adapter;
        int ret = 0;
        struct bss_descriptor *preqbssid;
        int i;

        ENTER();

        memset(pSSID, 0, sizeof(struct WLAN_802_11_SSID));

        wlan_scan_networks(priv, NULL);
        if (adapter->surpriseremoved)
                return -1;
        wait_event_interruptible(adapter->cmd_pending, !adapter->nr_cmd_pending);

        i = libertas_find_best_SSID_in_list(adapter, preferred_mode);
        if (i < 0) {
                ret = -1;
                goto out;
        }

        preqbssid = &adapter->scantable[i];
        memcpy(pSSID, &preqbssid->ssid,
               sizeof(struct WLAN_802_11_SSID));
        *out_mode = preqbssid->mode;

        if (!pSSID->ssidlength) {
                ret = -1;
        }

out:
        LEAVE();
        return ret;
}

/**
 *  @brief Scan Network
 *
 *  @param dev          A pointer to net_device structure
 *  @param info         A pointer to iw_request_info structure
 *  @param vwrq         A pointer to iw_param structure
 *  @param extra        A pointer to extra data buf
 *
 *  @return             0 --success, otherwise fail
 */
int libertas_set_scan(struct net_device *dev, struct iw_request_info *info,
                  struct iw_param *vwrq, char *extra)
{
        wlan_private *priv = dev->priv;
        wlan_adapter *adapter = priv->adapter;
        union iwreq_data wrqu;

        ENTER();

        if (!wlan_scan_networks(priv, NULL)) {
                memset(&wrqu, 0, sizeof(union iwreq_data));
                wireless_send_event(priv->wlan_dev.netdev, SIOCGIWSCAN, &wrqu,
                                    NULL);
        }

        if (adapter->surpriseremoved)
                return -1;

        LEAVE();
        return 0;
}

/**
 *  @brief Send a scan command for all available channels filtered on a spec
 *
 *  @param priv             A pointer to wlan_private structure
 *  @param prequestedssid   A pointer to AP's ssid
 *  @param keeppreviousscan Flag used to save/clear scan table before scan
 *
 *  @return                0-success, otherwise fail
 */
int libertas_send_specific_SSID_scan(wlan_private * priv,
                         struct WLAN_802_11_SSID *prequestedssid,
                         u8 keeppreviousscan)
{
        wlan_adapter *adapter = priv->adapter;
        struct wlan_ioctl_user_scan_cfg scancfg;

        ENTER();

        if (prequestedssid == NULL) {
                return -1;
        }

        memset(&scancfg, 0x00, sizeof(scancfg));

        memcpy(scancfg.specificSSID, prequestedssid->ssid,
               prequestedssid->ssidlength);
        scancfg.keeppreviousscan = keeppreviousscan;

        wlan_scan_networks(priv, &scancfg);
        if (adapter->surpriseremoved)
                return -1;
        wait_event_interruptible(adapter->cmd_pending, !adapter->nr_cmd_pending);

        LEAVE();
        return 0;
}

/**
 *  @brief scan an AP with specific BSSID
 *
 *  @param priv             A pointer to wlan_private structure
 *  @param bssid            A pointer to AP's bssid
 *  @param keeppreviousscan Flag used to save/clear scan table before scan
 *
 *  @return          0-success, otherwise fail
 */
int libertas_send_specific_BSSID_scan(wlan_private * priv, u8 * bssid, u8 keeppreviousscan)
{
        struct wlan_ioctl_user_scan_cfg scancfg;

        ENTER();

        if (bssid == NULL) {
                return -1;
        }

        memset(&scancfg, 0x00, sizeof(scancfg));
        memcpy(scancfg.specificBSSID, bssid, sizeof(scancfg.specificBSSID));
        scancfg.keeppreviousscan = keeppreviousscan;

        wlan_scan_networks(priv, &scancfg);
        if (priv->adapter->surpriseremoved)
                return -1;
        wait_event_interruptible(priv->adapter->cmd_pending,
                !priv->adapter->nr_cmd_pending);

        LEAVE();
        return 0;
}

/**
 *  @brief  Retrieve the scan table entries via wireless tools IOCTL call
 *
 *  @param dev          A pointer to net_device structure
 *  @param info         A pointer to iw_request_info structure
 *  @param dwrq         A pointer to iw_point structure
 *  @param extra        A pointer to extra data buf
 *
 *  @return             0 --success, otherwise fail
 */
int libertas_get_scan(struct net_device *dev, struct iw_request_info *info,
                  struct iw_point *dwrq, char *extra)
{
        wlan_private *priv = dev->priv;
        wlan_adapter *adapter = priv->adapter;
        int ret = 0;
        char *current_ev = extra;
        char *end_buf = extra + IW_SCAN_MAX_DATA;
        struct chan_freq_power *cfp;
        struct bss_descriptor *pscantable;
        char *current_val;      /* For rates */
        struct iw_event iwe;    /* Temporary buffer */
        int i;
        int j;
        int rate;
#define PERFECT_RSSI ((u8)50)
#define WORST_RSSI   ((u8)0)
#define RSSI_DIFF    ((u8)(PERFECT_RSSI - WORST_RSSI))
        u8 rssi;

        u8 buf[16 + 256 * 2];
        u8 *ptr;

        ENTER();

        /*
         * if there's either commands in the queue or one being
         * processed return -EAGAIN for iwlist to retry later.
         */
    if (adapter->nr_cmd_pending)
                return -EAGAIN;

        if (adapter->connect_status == libertas_connected)
                lbs_pr_debug(1, "Current ssid: %32s\n",
                       adapter->curbssparams.ssid.ssid);

        lbs_pr_debug(1, "Scan: Get: numinscantable = %d\n",
               adapter->numinscantable);

        /* The old API using SIOCGIWAPLIST had a hard limit of IW_MAX_AP.
         * The new API using SIOCGIWSCAN is only limited by buffer size
         * WE-14 -> WE-16 the buffer is limited to IW_SCAN_MAX_DATA bytes
         * which is 4096.
         */
        for (i = 0; i < adapter->numinscantable; i++) {
                if ((current_ev + MAX_SCAN_CELL_SIZE) >= end_buf) {
                        lbs_pr_debug(1, "i=%d break out: current_ev=%p end_buf=%p "
                               "MAX_SCAN_CELL_SIZE=%zd\n",
                               i, current_ev, end_buf, MAX_SCAN_CELL_SIZE);
                        break;
                }

                pscantable = &adapter->scantable[i];

                lbs_pr_debug(1, "i=%d  ssid: %32s\n", i, pscantable->ssid.ssid);

                cfp =
                    libertas_find_cfp_by_band_and_channel(adapter, 0,
                                                 pscantable->channel);
                if (!cfp) {
                        lbs_pr_debug(1, "Invalid channel number %d\n",
                               pscantable->channel);
                        continue;
                }

                if (!ssid_valid(&adapter->scantable[i].ssid)) {
                        continue;
                }

                /* First entry *MUST* be the AP MAC address */
                iwe.cmd = SIOCGIWAP;
                iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
                memcpy(iwe.u.ap_addr.sa_data,
                       &adapter->scantable[i].macaddress, ETH_ALEN);

                iwe.len = IW_EV_ADDR_LEN;
                current_ev =
                    iwe_stream_add_event(current_ev, end_buf, &iwe, iwe.len);

                //Add the ESSID
                iwe.u.data.length = adapter->scantable[i].ssid.ssidlength;

                if (iwe.u.data.length > 32) {
                        iwe.u.data.length = 32;
                }

                iwe.cmd = SIOCGIWESSID;
                iwe.u.data.flags = 1;
                iwe.len = IW_EV_POINT_LEN + iwe.u.data.length;
                current_ev = iwe_stream_add_point(current_ev, end_buf, &iwe,
                                                  adapter->scantable[i].ssid.
                                                  ssid);

                //Add mode
                iwe.cmd = SIOCGIWMODE;
                iwe.u.mode = adapter->scantable[i].mode;
                iwe.len = IW_EV_UINT_LEN;
                current_ev =
                    iwe_stream_add_event(current_ev, end_buf, &iwe, iwe.len);

                //frequency
                iwe.cmd = SIOCGIWFREQ;
                iwe.u.freq.m = (long)cfp->freq * 100000;
                iwe.u.freq.e = 1;
                iwe.len = IW_EV_FREQ_LEN;
                current_ev =
                    iwe_stream_add_event(current_ev, end_buf, &iwe, iwe.len);

                /* Add quality statistics */
                iwe.cmd = IWEVQUAL;
                iwe.u.qual.updated = IW_QUAL_ALL_UPDATED;
                iwe.u.qual.level = SCAN_RSSI(adapter->scantable[i].rssi);

                rssi = iwe.u.qual.level - MRVDRV_NF_DEFAULT_SCAN_VALUE;
                iwe.u.qual.qual =
                    (100 * RSSI_DIFF * RSSI_DIFF - (PERFECT_RSSI - rssi) *
                     (15 * (RSSI_DIFF) + 62 * (PERFECT_RSSI - rssi))) /
                    (RSSI_DIFF * RSSI_DIFF);
                if (iwe.u.qual.qual > 100)
                        iwe.u.qual.qual = 100;
                else if (iwe.u.qual.qual < 1)
                        iwe.u.qual.qual = 0;

                if (adapter->NF[TYPE_BEACON][TYPE_NOAVG] == 0) {
                        iwe.u.qual.noise = MRVDRV_NF_DEFAULT_SCAN_VALUE;
                } else {
                        iwe.u.qual.noise =
                            CAL_NF(adapter->NF[TYPE_BEACON][TYPE_NOAVG]);
                }
                if ((adapter->mode == IW_MODE_ADHOC) &&
                    !libertas_SSID_cmp(&adapter->curbssparams.ssid,
                             &adapter->scantable[i].ssid)
                    && adapter->adhoccreate) {
                        ret = libertas_prepare_and_send_command(priv,
                                                    cmd_802_11_rssi,
                                                    0,
                                                    cmd_option_waitforrsp,
                                                    0, NULL);

                        if (!ret) {
                                iwe.u.qual.level =
                                    CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_AVG] /
                                             AVG_SCALE,
                                             adapter->NF[TYPE_RXPD][TYPE_AVG] /
                                             AVG_SCALE);
                        }
                }
                iwe.len = IW_EV_QUAL_LEN;
                current_ev =
                    iwe_stream_add_event(current_ev, end_buf, &iwe, iwe.len);

                /* Add encryption capability */
                iwe.cmd = SIOCGIWENCODE;
                if (adapter->scantable[i].privacy) {
                        iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
                } else {
                        iwe.u.data.flags = IW_ENCODE_DISABLED;
                }
                iwe.u.data.length = 0;
                iwe.len = IW_EV_POINT_LEN + iwe.u.data.length;
                current_ev = iwe_stream_add_point(current_ev, end_buf, &iwe,
                                                  adapter->scantable->ssid.
                                                  ssid);

                current_val = current_ev + IW_EV_LCP_LEN;

                iwe.cmd = SIOCGIWRATE;

                iwe.u.bitrate.fixed = 0;
                iwe.u.bitrate.disabled = 0;
                iwe.u.bitrate.value = 0;

                /* Bit rate given in 500 kb/s units (+ 0x80) */
                for (j = 0; j < sizeof(adapter->scantable[i].libertas_supported_rates);
                     j++) {
                        if (adapter->scantable[i].libertas_supported_rates[j] == 0) {
                                break;
                        }
                        rate =
                            (adapter->scantable[i].libertas_supported_rates[j] & 0x7F) *
                            500000;
                        if (rate > iwe.u.bitrate.value) {
                                iwe.u.bitrate.value = rate;
                        }

                        iwe.u.bitrate.value =
                            (adapter->scantable[i].libertas_supported_rates[j]
                             & 0x7f) * 500000;
                        iwe.len = IW_EV_PARAM_LEN;
                        current_ev =
                            iwe_stream_add_value(current_ev, current_val,
                                                 end_buf, &iwe, iwe.len);

                }
                if ((adapter->scantable[i].mode == IW_MODE_ADHOC)
                    && !libertas_SSID_cmp(&adapter->curbssparams.ssid,
                                &adapter->scantable[i].ssid)
                    && adapter->adhoccreate) {
                        iwe.u.bitrate.value = 22 * 500000;
                }
                iwe.len = IW_EV_PARAM_LEN;
                current_ev =
                    iwe_stream_add_value(current_ev, current_val, end_buf, &iwe,
                                         iwe.len);

                /* Add new value to event */
                current_val = current_ev + IW_EV_LCP_LEN;

                if (adapter->scantable[i].rsn_ie[0] == WPA2_IE) {
                        memset(&iwe, 0, sizeof(iwe));
                        memset(buf, 0, sizeof(buf));
                        memcpy(buf, adapter->scantable[i].rsn_ie,
                                        adapter->scantable[i].rsn_ie_len);
                        iwe.cmd = IWEVGENIE;
                        iwe.u.data.length = adapter->scantable[i].rsn_ie_len;
                        iwe.len = IW_EV_POINT_LEN + iwe.u.data.length;
                        current_ev = iwe_stream_add_point(current_ev, end_buf,
                                        &iwe, buf);
                }
                if (adapter->scantable[i].wpa_ie[0] == WPA_IE) {
                        memset(&iwe, 0, sizeof(iwe));
                        memset(buf, 0, sizeof(buf));
                        memcpy(buf, adapter->scantable[i].wpa_ie,
                                        adapter->scantable[i].wpa_ie_len);
                        iwe.cmd = IWEVGENIE;
                        iwe.u.data.length = adapter->scantable[i].wpa_ie_len;
                        iwe.len = IW_EV_POINT_LEN + iwe.u.data.length;
                        current_ev = iwe_stream_add_point(current_ev, end_buf,
                                        &iwe, buf);
                }


                if (adapter->scantable[i].extra_ie != 0) {
                        memset(&iwe, 0, sizeof(iwe));
                        memset(buf, 0, sizeof(buf));
                        ptr = buf;
                        ptr += sprintf(ptr, "extra_ie");
                        iwe.u.data.length = strlen(buf);

                        lbs_pr_debug(1, "iwe.u.data.length %d\n",
                               iwe.u.data.length);
                        lbs_pr_debug(1, "BUF: %s \n", buf);

                        iwe.cmd = IWEVCUSTOM;
                        iwe.len = IW_EV_POINT_LEN + iwe.u.data.length;
                        current_ev =
                            iwe_stream_add_point(current_ev, end_buf, &iwe,
                                                 buf);
                }

                current_val = current_ev + IW_EV_LCP_LEN;

                /*
                 * Check if we added any event
                 */
                if ((current_val - current_ev) > IW_EV_LCP_LEN)
                        current_ev = current_val;
        }

        dwrq->length = (current_ev - extra);
        dwrq->flags = 0;

        LEAVE();
        return 0;
}

/**
 *  @brief Prepare a scan command to be sent to the firmware
 *
 *  Use the wlan_scan_cmd_config sent to the command processing module in
 *   the libertas_prepare_and_send_command to configure a cmd_ds_802_11_scan command
 *   struct to send to firmware.
 *
 *  The fixed fields specifying the BSS type and BSSID filters as well as a
 *   variable number/length of TLVs are sent in the command to firmware.
 *
 *  @param priv       A pointer to wlan_private structure
 *  @param cmd        A pointer to cmd_ds_command structure to be sent to
 *                    firmware with the cmd_DS_801_11_SCAN structure
 *  @param pdata_buf  Void pointer cast of a wlan_scan_cmd_config struct used
 *                    to set the fields/TLVs for the command sent to firmware
 *
 *  @return           0 or -1
 *
 *  @sa wlan_scan_create_channel_list
 */
int libertas_cmd_80211_scan(wlan_private * priv,
                         struct cmd_ds_command *cmd, void *pdata_buf)
{
        struct cmd_ds_802_11_scan *pscan = &cmd->params.scan;
        struct wlan_scan_cmd_config *pscancfg;

        ENTER();

        pscancfg = pdata_buf;

        /* Set fixed field variables in scan command */
        pscan->bsstype = pscancfg->bsstype;
        memcpy(pscan->BSSID, pscancfg->specificBSSID, sizeof(pscan->BSSID));
        memcpy(pscan->tlvbuffer, pscancfg->tlvbuffer, pscancfg->tlvbufferlen);

        cmd->command = cpu_to_le16(cmd_802_11_scan);

        /* size is equal to the sizeof(fixed portions) + the TLV len + header */
        cmd->size = cpu_to_le16(sizeof(pscan->bsstype)
                                     + sizeof(pscan->BSSID)
                                     + pscancfg->tlvbufferlen + S_DS_GEN);

        lbs_pr_debug(1, "SCAN_CMD: command=%x, size=%x, seqnum=%x\n",
               cmd->command, cmd->size, cmd->seqnum);
        LEAVE();
        return 0;
}

/**
 *  @brief This function handles the command response of scan
 *
 *   The response buffer for the scan command has the following
 *      memory layout:
 *
 *     .-----------------------------------------------------------.
 *     |  header (4 * sizeof(u16)):  Standard command response hdr |
 *     .-----------------------------------------------------------.
 *     |  bufsize (u16) : sizeof the BSS Description data          |
 *     .-----------------------------------------------------------.
 *     |  NumOfSet (u8) : Number of BSS Descs returned             |
 *     .-----------------------------------------------------------.
 *     |  BSSDescription data (variable, size given in bufsize)    |
 *     .-----------------------------------------------------------.
 *     |  TLV data (variable, size calculated using header->size,  |
 *     |            bufsize and sizeof the fixed fields above)     |
 *     .-----------------------------------------------------------.
 *
 *  @param priv    A pointer to wlan_private structure
 *  @param resp    A pointer to cmd_ds_command
 *
 *  @return        0 or -1
 */
int libertas_ret_80211_scan(wlan_private * priv, struct cmd_ds_command *resp)
{
        wlan_adapter *adapter = priv->adapter;
        struct cmd_ds_802_11_scan_rsp *pscan;
        struct bss_descriptor newbssentry;
        struct mrvlietypes_data *ptlv;
        struct mrvlietypes_tsftimestamp *ptsftlv;
        u8 *pbssinfo;
        u16 scanrespsize;
        int bytesleft;
        int numintable;
        int bssIdx;
        int idx;
        int tlvbufsize;
        u64 tsfval;

        ENTER();

        pscan = &resp->params.scanresp;

        if (pscan->nr_sets > MRVDRV_MAX_BSSID_LIST) {
        lbs_pr_debug(1,
                       "SCAN_RESP: Invalid number of AP returned (%d)!!\n",
                       pscan->nr_sets);
                LEAVE();
                return -1;
        }

        bytesleft = le16_to_cpu(pscan->bssdescriptsize);
        lbs_pr_debug(1, "SCAN_RESP: bssdescriptsize %d\n", bytesleft);

        scanrespsize = le16_to_cpu(resp->size);
        lbs_pr_debug(1, "SCAN_RESP: returned %d AP before parsing\n",
               pscan->nr_sets);

        numintable = adapter->numinscantable;
        pbssinfo = pscan->bssdesc_and_tlvbuffer;

        /* The size of the TLV buffer is equal to the entire command response
         *   size (scanrespsize) minus the fixed fields (sizeof()'s), the
         *   BSS Descriptions (bssdescriptsize as bytesLef) and the command
         *   response header (S_DS_GEN)
         */
        tlvbufsize = scanrespsize - (bytesleft + sizeof(pscan->bssdescriptsize)
                                     + sizeof(pscan->nr_sets)
                                     + S_DS_GEN);

        ptlv = (struct mrvlietypes_data *) (pscan->bssdesc_and_tlvbuffer + bytesleft);

        /* Search the TLV buffer space in the scan response for any valid TLVs */
        wlan_ret_802_11_scan_get_tlv_ptrs(ptlv, tlvbufsize, &ptsftlv);

        /*
         *  Process each scan response returned (pscan->nr_sets).  Save
         *    the information in the newbssentry and then insert into the
         *    driver scan table either as an update to an existing entry
         *    or as an addition at the end of the table
         */
        for (idx = 0; idx < pscan->nr_sets && bytesleft; idx++) {
                /* Zero out the newbssentry we are about to store info in */
                memset(&newbssentry, 0x00, sizeof(newbssentry));

                /* Process the data fields and IEs returned for this BSS */
                if ((InterpretBSSDescriptionWithIE(&newbssentry,
                                                   &pbssinfo,
                                                   &bytesleft) ==
                     0)
                    && CHECK_SSID_IS_VALID(&newbssentry.ssid)) {

            lbs_pr_debug(1,
                               "SCAN_RESP: BSSID = %02x:%02x:%02x:%02x:%02x:%02x\n",
                               newbssentry.macaddress[0],
                               newbssentry.macaddress[1],
                               newbssentry.macaddress[2],
                               newbssentry.macaddress[3],
                               newbssentry.macaddress[4],
                               newbssentry.macaddress[5]);

                        /*
                         * Search the scan table for the same bssid
                         */
                        for (bssIdx = 0; bssIdx < numintable; bssIdx++) {
                                if (memcmp(newbssentry.macaddress,
                                           adapter->scantable[bssIdx].
                                           macaddress,
                                           sizeof(newbssentry.macaddress)) ==
                                    0) {
                                        /*
                                         * If the SSID matches as well, it is a duplicate of
                                         *   this entry.  Keep the bssIdx set to this
                                         *   entry so we replace the old contents in the table
                                         */
                                        if ((newbssentry.ssid.ssidlength ==
                                             adapter->scantable[bssIdx].ssid.
                                             ssidlength)
                                            &&
                                            (memcmp
                                             (newbssentry.ssid.ssid,
                                              adapter->scantable[bssIdx].ssid.
                                              ssid,
                                              newbssentry.ssid.ssidlength) ==
                                             0)) {
                        lbs_pr_debug(1,
                                                       "SCAN_RESP: Duplicate of index: %d\n",
                                                       bssIdx);
                                                break;
                                        }
                                }
                        }
                        /*
                         * If the bssIdx is equal to the number of entries in the table,
                         *   the new entry was not a duplicate; append it to the scan
                         *   table
                         */
                        if (bssIdx == numintable) {
                                /* Range check the bssIdx, keep it limited to the last entry */
                                if (bssIdx == MRVDRV_MAX_BSSID_LIST) {
                                        bssIdx--;
                                } else {
                                        numintable++;
                                }
                        }

                        /*
                         * If the TSF TLV was appended to the scan results, save the
                         *   this entries TSF value in the networktsf field.  The
                         *   networktsf is the firmware's TSF value at the time the
                         *   beacon or probe response was received.
                         */
                        if (ptsftlv) {
                                memcpy(&tsfval, &ptsftlv->tsftable[idx],
                                       sizeof(tsfval));
                                tsfval = le64_to_cpu(tsfval);

                                memcpy(&newbssentry.networktsf,
                                       &tsfval, sizeof(newbssentry.networktsf));
                        }

                        /* Copy the locally created newbssentry to the scan table */
                        memcpy(&adapter->scantable[bssIdx],
                               &newbssentry,
                               sizeof(adapter->scantable[bssIdx]));

                } else {

                        /* error parsing/interpreting the scan response, skipped */
                        lbs_pr_debug(1, "SCAN_RESP: "
                               "InterpretBSSDescriptionWithIE returned ERROR\n");
                }
        }

        lbs_pr_debug(1, "SCAN_RESP: Scanned %2d APs, %d valid, %d total\n",
               pscan->nr_sets, numintable - adapter->numinscantable,
               numintable);

        /* Update the total number of BSSIDs in the scan table */
        adapter->numinscantable = numintable;

        LEAVE();
        return 0;
}