Merge branch 'for-linus' of git://git.infradead.org/users/sameo/mfd-2.6

[linux-btrfs-devel.git] / drivers / net / wireless / mwifiex / scan.c

/*
 * Marvell Wireless LAN device driver: scan ioctl and command handling
 *
 * Copyright (C) 2011, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "11n.h"
#include "cfg80211.h"

/* The maximum number of channels the firmware can scan per command */
#define MWIFIEX_MAX_CHANNELS_PER_SPECIFIC_SCAN   14

#define MWIFIEX_CHANNELS_PER_SCAN_CMD            4

/* Memory needed to store a max sized Channel List TLV for a firmware scan */
#define CHAN_TLV_MAX_SIZE  (sizeof(struct mwifiex_ie_types_header)         \
                                + (MWIFIEX_MAX_CHANNELS_PER_SPECIFIC_SCAN     \
                                *sizeof(struct mwifiex_chan_scan_param_set)))

/* Memory needed to store supported rate */
#define RATE_TLV_MAX_SIZE   (sizeof(struct mwifiex_ie_types_rates_param_set) \
                                + HOSTCMD_SUPPORTED_RATES)

/* Memory needed to store a max number/size WildCard SSID TLV for a firmware
        scan */
#define WILDCARD_SSID_TLV_MAX_SIZE  \
        (MWIFIEX_MAX_SSID_LIST_LENGTH *                                 \
                (sizeof(struct mwifiex_ie_types_wildcard_ssid_params)   \
                        + IEEE80211_MAX_SSID_LEN))

/* Maximum memory needed for a mwifiex_scan_cmd_config with all TLVs at max */
#define MAX_SCAN_CFG_ALLOC (sizeof(struct mwifiex_scan_cmd_config)        \
                                + sizeof(struct mwifiex_ie_types_num_probes)   \
                                + sizeof(struct mwifiex_ie_types_htcap)       \
                                + CHAN_TLV_MAX_SIZE                 \
                                + RATE_TLV_MAX_SIZE                 \
                                + WILDCARD_SSID_TLV_MAX_SIZE)


union mwifiex_scan_cmd_config_tlv {
        /* Scan configuration (variable length) */
        struct mwifiex_scan_cmd_config config;
        /* Max allocated block */
        u8 config_alloc_buf[MAX_SCAN_CFG_ALLOC];
};

enum cipher_suite {
        CIPHER_SUITE_TKIP,
        CIPHER_SUITE_CCMP,
        CIPHER_SUITE_MAX
};
static u8 mwifiex_wpa_oui[CIPHER_SUITE_MAX][4] = {
        { 0x00, 0x50, 0xf2, 0x02 },     /* TKIP */
        { 0x00, 0x50, 0xf2, 0x04 },     /* AES  */
};
static u8 mwifiex_rsn_oui[CIPHER_SUITE_MAX][4] = {
        { 0x00, 0x0f, 0xac, 0x02 },     /* TKIP */
        { 0x00, 0x0f, 0xac, 0x04 },     /* AES  */
};

/*
 * This function parses a given IE for a given OUI.
 *
 * This is used to parse a WPA/RSN IE to find if it has
 * a given oui in PTK.
 */
static u8
mwifiex_search_oui_in_ie(struct ie_body *iebody, u8 *oui)
{
        u8 count;

        count = iebody->ptk_cnt[0];

        /* There could be multiple OUIs for PTK hence
           1) Take the length.
           2) Check all the OUIs for AES.
           3) If one of them is AES then pass success. */
        while (count) {
                if (!memcmp(iebody->ptk_body, oui, sizeof(iebody->ptk_body)))
                        return MWIFIEX_OUI_PRESENT;

                --count;
                if (count)
                        iebody = (struct ie_body *) ((u8 *) iebody +
                                                sizeof(iebody->ptk_body));
        }

        pr_debug("info: %s: OUI is not found in PTK\n", __func__);
        return MWIFIEX_OUI_NOT_PRESENT;
}

/*
 * This function checks if a given OUI is present in a RSN IE.
 *
 * The function first checks if a RSN IE is present or not in the
 * BSS descriptor. It tries to locate the OUI only if such an IE is
 * present.
 */
static u8
mwifiex_is_rsn_oui_present(struct mwifiex_bssdescriptor *bss_desc, u32 cipher)
{
        u8 *oui;
        struct ie_body *iebody;
        u8 ret = MWIFIEX_OUI_NOT_PRESENT;

        if (((bss_desc->bcn_rsn_ie) && ((*(bss_desc->bcn_rsn_ie)).
                                        ieee_hdr.element_id == WLAN_EID_RSN))) {
                iebody = (struct ie_body *)
                         (((u8 *) bss_desc->bcn_rsn_ie->data) +
                         RSN_GTK_OUI_OFFSET);
                oui = &mwifiex_rsn_oui[cipher][0];
                ret = mwifiex_search_oui_in_ie(iebody, oui);
                if (ret)
                        return ret;
        }
        return ret;
}

/*
 * This function checks if a given OUI is present in a WPA IE.
 *
 * The function first checks if a WPA IE is present or not in the
 * BSS descriptor. It tries to locate the OUI only if such an IE is
 * present.
 */
static u8
mwifiex_is_wpa_oui_present(struct mwifiex_bssdescriptor *bss_desc, u32 cipher)
{
        u8 *oui;
        struct ie_body *iebody;
        u8 ret = MWIFIEX_OUI_NOT_PRESENT;

        if (((bss_desc->bcn_wpa_ie) && ((*(bss_desc->bcn_wpa_ie)).
                                      vend_hdr.element_id == WLAN_EID_WPA))) {
                iebody = (struct ie_body *) bss_desc->bcn_wpa_ie->data;
                oui = &mwifiex_wpa_oui[cipher][0];
                ret = mwifiex_search_oui_in_ie(iebody, oui);
                if (ret)
                        return ret;
        }
        return ret;
}

/*
 * This function compares two SSIDs and checks if they match.
 */
s32
mwifiex_ssid_cmp(struct mwifiex_802_11_ssid *ssid1,
                 struct mwifiex_802_11_ssid *ssid2)
{
        if (!ssid1 || !ssid2 || (ssid1->ssid_len != ssid2->ssid_len))
                return -1;
        return memcmp(ssid1->ssid, ssid2->ssid, ssid1->ssid_len);
}

/*
 * Sends IOCTL request to get the best BSS.
 *
 * This function allocates the IOCTL request buffer, fills it
 * with requisite parameters and calls the IOCTL handler.
 */
int mwifiex_find_best_bss(struct mwifiex_private *priv,
                          struct mwifiex_ssid_bssid *ssid_bssid)
{
        struct mwifiex_ssid_bssid tmp_ssid_bssid;
        u8 *mac;

        if (!ssid_bssid)
                return -1;

        memcpy(&tmp_ssid_bssid, ssid_bssid,
               sizeof(struct mwifiex_ssid_bssid));

        if (!mwifiex_bss_ioctl_find_bss(priv, &tmp_ssid_bssid)) {
                memcpy(ssid_bssid, &tmp_ssid_bssid,
                       sizeof(struct mwifiex_ssid_bssid));
                mac = (u8 *) &ssid_bssid->bssid;
                dev_dbg(priv->adapter->dev, "cmd: found network: ssid=%s,"
                                " %pM\n", ssid_bssid->ssid.ssid, mac);
                return 0;
        }

        return -1;
}

/*
 * Sends IOCTL request to start a scan with user configurations.
 *
 * This function allocates the IOCTL request buffer, fills it
 * with requisite parameters and calls the IOCTL handler.
 *
 * Upon completion, it also generates a wireless event to notify
 * applications.
 */
int mwifiex_set_user_scan_ioctl(struct mwifiex_private *priv,
                                struct mwifiex_user_scan_cfg *scan_req)
{
        int status;

        priv->adapter->cmd_wait_q.condition = false;

        status = mwifiex_scan_networks(priv, scan_req);
        if (!status)
                status = mwifiex_wait_queue_complete(priv->adapter);

        return status;
}

/*
 * This function checks if wapi is enabled in driver and scanned network is
 * compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_wapi(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc)
{
        if (priv->sec_info.wapi_enabled &&
            (bss_desc->bcn_wapi_ie &&
             ((*(bss_desc->bcn_wapi_ie)).ieee_hdr.element_id ==
                        WLAN_EID_BSS_AC_ACCESS_DELAY))) {
                return true;
        }
        return false;
}

/*
 * This function checks if driver is configured with no security mode and
 * scanned network is compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_no_sec(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_DISABLED
            && !priv->sec_info.wpa_enabled && !priv->sec_info.wpa2_enabled
            && ((!bss_desc->bcn_wpa_ie) ||
                ((*(bss_desc->bcn_wpa_ie)).vend_hdr.element_id !=
            WLAN_EID_WPA))
            && ((!bss_desc->bcn_rsn_ie) ||
                ((*(bss_desc->bcn_rsn_ie)).ieee_hdr.element_id !=
            WLAN_EID_RSN))
            && !priv->sec_info.encryption_mode
            && !bss_desc->privacy) {
                return true;
        }
        return false;
}

/*
 * This function checks if static WEP is enabled in driver and scanned network
 * is compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_static_wep(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_ENABLED
            && !priv->sec_info.wpa_enabled && !priv->sec_info.wpa2_enabled
            && bss_desc->privacy) {
                return true;
        }
        return false;
}

/*
 * This function checks if wpa is enabled in driver and scanned network is
 * compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_wpa(struct mwifiex_private *priv,
                                      struct mwifiex_bssdescriptor *bss_desc,
                                      int index)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_DISABLED
            && priv->sec_info.wpa_enabled && !priv->sec_info.wpa2_enabled
            && ((bss_desc->bcn_wpa_ie) && ((*(bss_desc->bcn_wpa_ie)).vend_hdr.
                                                element_id == WLAN_EID_WPA))
           /*
            * Privacy bit may NOT be set in some APs like
            * LinkSys WRT54G && bss_desc->privacy
            */
         ) {
                dev_dbg(priv->adapter->dev, "info: %s: WPA: index=%d"
                        " wpa_ie=%#x wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
                        "EncMode=%#x privacy=%#x\n", __func__, index,
                        (bss_desc->bcn_wpa_ie) ?
                        (*(bss_desc->bcn_wpa_ie)).
                        vend_hdr.element_id : 0,
                        (bss_desc->bcn_rsn_ie) ?
                        (*(bss_desc->bcn_rsn_ie)).
                        ieee_hdr.element_id : 0,
                        (priv->sec_info.wep_status ==
                        MWIFIEX_802_11_WEP_ENABLED) ? "e" : "d",
                        (priv->sec_info.wpa_enabled) ? "e" : "d",
                        (priv->sec_info.wpa2_enabled) ? "e" : "d",
                        priv->sec_info.encryption_mode,
                        bss_desc->privacy);
                return true;
        }
        return false;
}

/*
 * This function checks if wpa2 is enabled in driver and scanned network is
 * compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_wpa2(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc,
                                       int index)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_DISABLED
           && !priv->sec_info.wpa_enabled && priv->sec_info.wpa2_enabled
           && ((bss_desc->bcn_rsn_ie) && ((*(bss_desc->bcn_rsn_ie)).ieee_hdr.
                                                element_id == WLAN_EID_RSN))
           /*
            * Privacy bit may NOT be set in some APs like
            * LinkSys WRT54G && bss_desc->privacy
            */
         ) {
                dev_dbg(priv->adapter->dev, "info: %s: WPA2: index=%d"
                        " wpa_ie=%#x wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s "
                        "EncMode=%#x privacy=%#x\n", __func__, index,
                        (bss_desc->bcn_wpa_ie) ?
                        (*(bss_desc->bcn_wpa_ie)).
                        vend_hdr.element_id : 0,
                        (bss_desc->bcn_rsn_ie) ?
                        (*(bss_desc->bcn_rsn_ie)).
                        ieee_hdr.element_id : 0,
                        (priv->sec_info.wep_status ==
                        MWIFIEX_802_11_WEP_ENABLED) ? "e" : "d",
                        (priv->sec_info.wpa_enabled) ? "e" : "d",
                        (priv->sec_info.wpa2_enabled) ? "e" : "d",
                        priv->sec_info.encryption_mode,
                        bss_desc->privacy);
                return true;
        }
        return false;
}

/*
 * This function checks if adhoc AES is enabled in driver and scanned network is
 * compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_adhoc_aes(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_DISABLED
            && !priv->sec_info.wpa_enabled && !priv->sec_info.wpa2_enabled
            && ((!bss_desc->bcn_wpa_ie) || ((*(bss_desc->bcn_wpa_ie)).vend_hdr.
                   element_id != WLAN_EID_WPA))
            && ((!bss_desc->bcn_rsn_ie) || ((*(bss_desc->bcn_rsn_ie)).ieee_hdr.
                   element_id != WLAN_EID_RSN))
            && !priv->sec_info.encryption_mode
            && bss_desc->privacy) {
                return true;
        }
        return false;
}

/*
 * This function checks if dynamic WEP is enabled in driver and scanned network
 * is compatible with it.
 */
static bool
mwifiex_is_network_compatible_for_dynamic_wep(struct mwifiex_private *priv,
                                       struct mwifiex_bssdescriptor *bss_desc,
                                       int index)
{
        if (priv->sec_info.wep_status == MWIFIEX_802_11_WEP_DISABLED
            && !priv->sec_info.wpa_enabled && !priv->sec_info.wpa2_enabled
            && ((!bss_desc->bcn_wpa_ie) || ((*(bss_desc->bcn_wpa_ie)).vend_hdr.
                   element_id != WLAN_EID_WPA))
            && ((!bss_desc->bcn_rsn_ie) || ((*(bss_desc->bcn_rsn_ie)).ieee_hdr.
                   element_id != WLAN_EID_RSN))
            && priv->sec_info.encryption_mode
            && bss_desc->privacy) {
                dev_dbg(priv->adapter->dev, "info: %s: dynamic "
                        "WEP: index=%d wpa_ie=%#x wpa2_ie=%#x "
                        "EncMode=%#x privacy=%#x\n",
                        __func__, index,
                        (bss_desc->bcn_wpa_ie) ?
                        (*(bss_desc->bcn_wpa_ie)).
                        vend_hdr.element_id : 0,
                        (bss_desc->bcn_rsn_ie) ?
                        (*(bss_desc->bcn_rsn_ie)).
                        ieee_hdr.element_id : 0,
                        priv->sec_info.encryption_mode,
                        bss_desc->privacy);
                return true;
        }
        return false;
}

/*
 * This function checks if a scanned network is 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
 *    0       1       0      0      x        1x    1   x   yes WPA (disable
 *                                                         HT if no AES)
 *    0       0       1      0      x        1x    x   1   yes WPA2 (disable
 *                                                         HT if no AES)
 *    0       0       0      1     NONE      1     0   0   yes Ad-hoc AES
 *    1       0       0      0     NONE      1     0   0   yes Static WEP
 *                                                         (disable HT)
 *    0       0       0      0    !=NONE     1     0   0   yes Dynamic WEP
 *
 * Compatibility is not matched while roaming, except for mode.
 */
static s32
mwifiex_is_network_compatible(struct mwifiex_private *priv, u32 index, u32 mode)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_bssdescriptor *bss_desc;

        bss_desc = &adapter->scan_table[index];
        bss_desc->disable_11n = false;

        /* Don't check for compatibility if roaming */
        if (priv->media_connected && (priv->bss_mode == NL80211_IFTYPE_STATION)
            && (bss_desc->bss_mode == NL80211_IFTYPE_STATION))
                return index;

        if (priv->wps.session_enable) {
                dev_dbg(adapter->dev,
                        "info: return success directly in WPS period\n");
                return index;
        }

        if (mwifiex_is_network_compatible_for_wapi(priv, bss_desc)) {
                dev_dbg(adapter->dev, "info: return success for WAPI AP\n");
                return index;
        }

        if (bss_desc->bss_mode == mode) {
                if (mwifiex_is_network_compatible_for_no_sec(priv, bss_desc)) {
                        /* No security */
                        return index;
                } else if (mwifiex_is_network_compatible_for_static_wep(priv,
                                                                bss_desc)) {
                        /* Static WEP enabled */
                        dev_dbg(adapter->dev, "info: Disable 11n in WEP mode.\n");
                        bss_desc->disable_11n = true;
                        return index;
                } else if (mwifiex_is_network_compatible_for_wpa(priv, bss_desc,
                                                                 index)) {
                        /* WPA enabled */
                        if (((priv->adapter->config_bands & BAND_GN
                              || priv->adapter->config_bands & BAND_AN)
                              && bss_desc->bcn_ht_cap)
                              && !mwifiex_is_wpa_oui_present(bss_desc,
                                        CIPHER_SUITE_CCMP)) {

                                if (mwifiex_is_wpa_oui_present(bss_desc,
                                            CIPHER_SUITE_TKIP)) {
                                        dev_dbg(adapter->dev,
                                                "info: Disable 11n if AES "
                                                "is not supported by AP\n");
                                        bss_desc->disable_11n = true;
                                } else {
                                        return -1;
                                }
                        }
                        return index;
                } else if (mwifiex_is_network_compatible_for_wpa2(priv,
                                                        bss_desc, index)) {
                        /* WPA2 enabled */
                        if (((priv->adapter->config_bands & BAND_GN
                              || priv->adapter->config_bands & BAND_AN)
                              && bss_desc->bcn_ht_cap)
                              && !mwifiex_is_rsn_oui_present(bss_desc,
                                        CIPHER_SUITE_CCMP)) {

                                if (mwifiex_is_rsn_oui_present(bss_desc,
                                            CIPHER_SUITE_TKIP)) {
                                        dev_dbg(adapter->dev,
                                                "info: Disable 11n if AES "
                                                "is not supported by AP\n");
                                        bss_desc->disable_11n = true;
                                } else {
                                        return -1;
                                }
                        }
                        return index;
                } else if (mwifiex_is_network_compatible_for_adhoc_aes(priv,
                                                                bss_desc)) {
                        /* Ad-hoc AES enabled */
                        return index;
                } else if (mwifiex_is_network_compatible_for_dynamic_wep(priv,
                                                        bss_desc, index)) {
                        /* Dynamic WEP enabled */
                        return index;
                }

                /* Security doesn't match */
                dev_dbg(adapter->dev, "info: %s: failed: index=%d "
                       "wpa_ie=%#x wpa2_ie=%#x WEP=%s WPA=%s WPA2=%s EncMode"
                       "=%#x privacy=%#x\n",
                       __func__, index,
                       (bss_desc->bcn_wpa_ie) ?
                       (*(bss_desc->bcn_wpa_ie)).vend_hdr.
                       element_id : 0,
                       (bss_desc->bcn_rsn_ie) ?
                       (*(bss_desc->bcn_rsn_ie)).ieee_hdr.
                       element_id : 0,
                       (priv->sec_info.wep_status ==
                                MWIFIEX_802_11_WEP_ENABLED) ? "e" : "d",
                       (priv->sec_info.wpa_enabled) ? "e" : "d",
                       (priv->sec_info.wpa2_enabled) ? "e" : "d",
                       priv->sec_info.encryption_mode, bss_desc->privacy);
                return -1;
        }

        /* Mode doesn't match */
        return -1;
}

/*
 * This function finds the best SSID in the scan list.
 *
 * It searches the scan table for the best SSID that also matches the current
 * adapter network preference (mode, security etc.).
 */
static s32
mwifiex_find_best_network_in_list(struct mwifiex_private *priv)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        u32 mode = priv->bss_mode;
        s32 best_net = -1;
        s32 best_rssi = 0;
        u32 i;

        dev_dbg(adapter->dev, "info: num of BSSIDs = %d\n",
                                adapter->num_in_scan_table);

        for (i = 0; i < adapter->num_in_scan_table; i++) {
                switch (mode) {
                case NL80211_IFTYPE_STATION:
                case NL80211_IFTYPE_ADHOC:
                        if (mwifiex_is_network_compatible(priv, i, mode) >= 0) {
                                if (SCAN_RSSI(adapter->scan_table[i].rssi) >
                                    best_rssi) {
                                        best_rssi = SCAN_RSSI(adapter->
                                                          scan_table[i].rssi);
                                        best_net = i;
                                }
                        }
                        break;
                case NL80211_IFTYPE_UNSPECIFIED:
                default:
                        if (SCAN_RSSI(adapter->scan_table[i].rssi) >
                            best_rssi) {
                                best_rssi = SCAN_RSSI(adapter->scan_table[i].
                                                      rssi);
                                best_net = i;
                        }
                        break;
                }
        }

        return best_net;
}

/*
 * This function creates a channel list for the driver to scan, based
 * on region/band information.
 *
 * This routine is used for any scan that is not provided with a
 * specific channel list to scan.
 */
static void
mwifiex_scan_create_channel_list(struct mwifiex_private *priv,
                                const struct mwifiex_user_scan_cfg
                                *user_scan_in,
                                struct mwifiex_chan_scan_param_set
                                *scan_chan_list,
                                u8 filtered_scan)
{
        enum ieee80211_band band;
        struct ieee80211_supported_band *sband;
        struct ieee80211_channel *ch;
        struct mwifiex_adapter *adapter = priv->adapter;
        int chan_idx = 0, i;
        u8 scan_type;

        for (band = 0; (band < IEEE80211_NUM_BANDS) ; band++) {

                if (!priv->wdev->wiphy->bands[band])
                        continue;

                sband = priv->wdev->wiphy->bands[band];

                for (i = 0; (i < sband->n_channels) ; i++, chan_idx++) {
                        ch = &sband->channels[i];
                        if (ch->flags & IEEE80211_CHAN_DISABLED)
                                continue;
                        scan_chan_list[chan_idx].radio_type = band;
                        scan_type = ch->flags & IEEE80211_CHAN_PASSIVE_SCAN;
                        if (user_scan_in &&
                                user_scan_in->chan_list[0].scan_time)
                                scan_chan_list[chan_idx].max_scan_time =
                                        cpu_to_le16((u16) user_scan_in->
                                        chan_list[0].scan_time);
                        else if (scan_type == MWIFIEX_SCAN_TYPE_PASSIVE)
                                scan_chan_list[chan_idx].max_scan_time =
                                        cpu_to_le16(adapter->passive_scan_time);
                        else
                                scan_chan_list[chan_idx].max_scan_time =
                                        cpu_to_le16(adapter->active_scan_time);
                        if (scan_type == MWIFIEX_SCAN_TYPE_PASSIVE)
                                scan_chan_list[chan_idx].chan_scan_mode_bitmap
                                        |= MWIFIEX_PASSIVE_SCAN;
                        else
                                scan_chan_list[chan_idx].chan_scan_mode_bitmap
                                        &= ~MWIFIEX_PASSIVE_SCAN;
                        scan_chan_list[chan_idx].chan_number =
                                                        (u32) ch->hw_value;
                        if (filtered_scan) {
                                scan_chan_list[chan_idx].max_scan_time =
                                cpu_to_le16(adapter->specific_scan_time);
                                scan_chan_list[chan_idx].chan_scan_mode_bitmap
                                        |= MWIFIEX_DISABLE_CHAN_FILT;
                        }
                }

        }
}

/*
 * This function constructs and sends multiple scan config commands to
 * the firmware.
 *
 * Previous routines in the code flow have created a scan command configuration
 * with any requested TLVs.  This function splits the channel TLV into maximum
 * channels supported per scan lists and sends the portion of the channel TLV,
 * along with the other TLVs, to the firmware.
 */
static int
mwifiex_scan_channel_list(struct mwifiex_private *priv,
                          u32 max_chan_per_scan, u8 filtered_scan,
                          struct mwifiex_scan_cmd_config *scan_cfg_out,
                          struct mwifiex_ie_types_chan_list_param_set
                          *chan_tlv_out,
                          struct mwifiex_chan_scan_param_set *scan_chan_list)
{
        int ret = 0;
        struct mwifiex_chan_scan_param_set *tmp_chan_list;
        struct mwifiex_chan_scan_param_set *start_chan;

        u32 tlv_idx;
        u32 total_scan_time;
        u32 done_early;

        if (!scan_cfg_out || !chan_tlv_out || !scan_chan_list) {
                dev_dbg(priv->adapter->dev,
                        "info: Scan: Null detect: %p, %p, %p\n",
                       scan_cfg_out, chan_tlv_out, scan_chan_list);
                return -1;
        }

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

        /* Set the temp channel struct pointer to the start of the desired
           list */
        tmp_chan_list = scan_chan_list;

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

                tlv_idx = 0;
                total_scan_time = 0;
                chan_tlv_out->header.len = 0;
                start_chan = tmp_chan_list;
                done_early = false;

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

                        dev_dbg(priv->adapter->dev,
                                "info: Scan: Chan(%3d), Radio(%d),"
                                " Mode(%d, %d), Dur(%d)\n",
                               tmp_chan_list->chan_number,
                               tmp_chan_list->radio_type,
                               tmp_chan_list->chan_scan_mode_bitmap
                               & MWIFIEX_PASSIVE_SCAN,
                               (tmp_chan_list->chan_scan_mode_bitmap
                               & MWIFIEX_DISABLE_CHAN_FILT) >> 1,
                               le16_to_cpu(tmp_chan_list->max_scan_time));

                        /* Copy the current channel TLV to the command being
                           prepared */
                        memcpy(chan_tlv_out->chan_scan_param + tlv_idx,
                               tmp_chan_list,
                               sizeof(chan_tlv_out->chan_scan_param));

                        /* Increment the TLV header length by the size
                           appended */
                        chan_tlv_out->header.len =
                        cpu_to_le16(le16_to_cpu(chan_tlv_out->header.len) +
                        (sizeof(chan_tlv_out->chan_scan_param)));

                        /*
                         * 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.
                         */
                        scan_cfg_out->tlv_buf_len = (u32) ((u8 *) chan_tlv_out -
                                                        scan_cfg_out->tlv_buf);

                        /* Add the size of the channel tlv header and the data
                           length */
                        scan_cfg_out->tlv_buf_len +=
                                (sizeof(chan_tlv_out->header)
                                 + le16_to_cpu(chan_tlv_out->header.len));

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

                        /* Count the total scan time per command */
                        total_scan_time +=
                                le16_to_cpu(tmp_chan_list->max_scan_time);

                        done_early = false;

                        /* 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 (!filtered_scan && (tmp_chan_list->chan_number == 1
                                || tmp_chan_list->chan_number == 6
                                || tmp_chan_list->chan_number == 11))
                                done_early = true;

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

                        /* 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 (!filtered_scan && (tmp_chan_list->chan_number == 1
                                || tmp_chan_list->chan_number == 6
                                || tmp_chan_list->chan_number == 11))
                                done_early = true;
                }

                /* The total scan time should be less than scan command timeout
                   value */
                if (total_scan_time > MWIFIEX_MAX_TOTAL_SCAN_TIME) {
                        dev_err(priv->adapter->dev, "total scan time %dms"
                                " is over limit (%dms), scan skipped\n",
                                total_scan_time, MWIFIEX_MAX_TOTAL_SCAN_TIME);
                        ret = -1;
                        break;
                }

                priv->adapter->scan_channels = start_chan;

                /* Send the scan command to the firmware with the specified
                   cfg */
                ret = mwifiex_send_cmd_async(priv, HostCmd_CMD_802_11_SCAN,
                                             HostCmd_ACT_GEN_SET, 0,
                                             scan_cfg_out);
                if (ret)
                        break;
        }

        if (ret)
                return -1;

        return 0;
}

/*
 * This function constructs a scan command configuration structure to use
 * in scan commands.
 *
 * Application layer or other functions can invoke network scanning
 * with a scan configuration supplied in a user scan configuration structure.
 * This structure is used as the basis of one or many scan command configuration
 * commands that are sent to the command processing module and eventually to the
 * firmware.
 *
 * This function creates a scan command configuration structure  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, the filter is disabled/cleared.
 * If the number of probes is not set, adapter default setting is used.
 */
static void
mwifiex_scan_setup_scan_config(struct mwifiex_private *priv,
                               const struct mwifiex_user_scan_cfg *user_scan_in,
                               struct mwifiex_scan_cmd_config *scan_cfg_out,
                               struct mwifiex_ie_types_chan_list_param_set
                               **chan_list_out,
                               struct mwifiex_chan_scan_param_set
                               *scan_chan_list,
                               u8 *max_chan_per_scan, u8 *filtered_scan,
                               u8 *scan_current_only)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_ie_types_num_probes *num_probes_tlv;
        struct mwifiex_ie_types_wildcard_ssid_params *wildcard_ssid_tlv;
        struct mwifiex_ie_types_rates_param_set *rates_tlv;
        const u8 zero_mac[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
        u8 *tlv_pos;
        u32 num_probes;
        u32 ssid_len;
        u32 chan_idx;
        u32 scan_type;
        u16 scan_dur;
        u8 channel;
        u8 radio_type;
        u32 ssid_idx;
        u8 ssid_filter;
        u8 rates[MWIFIEX_SUPPORTED_RATES];
        u32 rates_size;
        struct mwifiex_ie_types_htcap *ht_cap;

        /* The tlv_buf_len 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 *chan_list_out.  The difference
           between the *chan_list_out and the tlv_buf start will be used to
           calculate the size of anything we add in this routine. */
        scan_cfg_out->tlv_buf_len = 0;

        /* Running tlv pointer.  Assigned to chan_list_out at end of function
           so later routines know where channels can be added to the command
           buf */
        tlv_pos = scan_cfg_out->tlv_buf;

        /* Initialize the scan as un-filtered; the flag is later set to TRUE
           below if a SSID or BSSID filter is sent in the command */
        *filtered_scan = false;

        /* 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. */
        *scan_current_only = false;

        if (user_scan_in) {

                /* Default the ssid_filter flag to TRUE, set false under
                   certain wildcard conditions and qualified by the existence
                   of an SSID list before marking the scan as filtered */
                ssid_filter = true;

                /* Set the BSS type scan filter, use Adapter setting if
                   unset */
                scan_cfg_out->bss_mode =
                        (user_scan_in->bss_mode ? (u8) user_scan_in->
                         bss_mode : (u8) adapter->scan_mode);

                /* Set the number of probes to send, use Adapter setting
                   if unset */
                num_probes =
                        (user_scan_in->num_probes ? user_scan_in->
                         num_probes : adapter->scan_probes);

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

                for (ssid_idx = 0;
                     ((ssid_idx < ARRAY_SIZE(user_scan_in->ssid_list))
                      && (*user_scan_in->ssid_list[ssid_idx].ssid
                          || user_scan_in->ssid_list[ssid_idx].max_len));
                     ssid_idx++) {

                        ssid_len = strlen(user_scan_in->ssid_list[ssid_idx].
                                          ssid) + 1;

                        wildcard_ssid_tlv =
                                (struct mwifiex_ie_types_wildcard_ssid_params *)
                                tlv_pos;
                        wildcard_ssid_tlv->header.type =
                                cpu_to_le16(TLV_TYPE_WILDCARDSSID);
                        wildcard_ssid_tlv->header.len = cpu_to_le16(
                                (u16) (ssid_len + sizeof(wildcard_ssid_tlv->
                                                         max_ssid_length)));
                        wildcard_ssid_tlv->max_ssid_length =
                                user_scan_in->ssid_list[ssid_idx].max_len;

                        memcpy(wildcard_ssid_tlv->ssid,
                               user_scan_in->ssid_list[ssid_idx].ssid,
                               ssid_len);

                        tlv_pos += (sizeof(wildcard_ssid_tlv->header)
                                + le16_to_cpu(wildcard_ssid_tlv->header.len));

                        dev_dbg(adapter->dev, "info: scan: ssid_list[%d]: %s, %d\n",
                                ssid_idx, wildcard_ssid_tlv->ssid,
                                wildcard_ssid_tlv->max_ssid_length);

                        /* Empty wildcard ssid with a maxlen will match many or
                           potentially all SSIDs (maxlen == 32), therefore do
                           not treat the scan as
                           filtered. */
                        if (!ssid_len && wildcard_ssid_tlv->max_ssid_length)
                                ssid_filter = false;

                }

                /*
                 *  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 ((ssid_idx && ssid_filter)
                    || memcmp(scan_cfg_out->specific_bssid, &zero_mac,
                              sizeof(zero_mac)))
                        *filtered_scan = true;
        } else {
                scan_cfg_out->bss_mode = (u8) adapter->scan_mode;
                num_probes = adapter->scan_probes;
        }

        /*
         *  If a specific BSSID or SSID is used, the number of channels in the
         *  scan command will be increased to the absolute maximum.
         */
        if (*filtered_scan)
                *max_chan_per_scan = MWIFIEX_MAX_CHANNELS_PER_SPECIFIC_SCAN;
        else
                *max_chan_per_scan = MWIFIEX_CHANNELS_PER_SCAN_CMD;

        /* If the input config or adapter has the number of Probes set,
           add tlv */
        if (num_probes) {

                dev_dbg(adapter->dev, "info: scan: num_probes = %d\n",
                                                num_probes);

                num_probes_tlv = (struct mwifiex_ie_types_num_probes *) tlv_pos;
                num_probes_tlv->header.type = cpu_to_le16(TLV_TYPE_NUMPROBES);
                num_probes_tlv->header.len =
                        cpu_to_le16(sizeof(num_probes_tlv->num_probes));
                num_probes_tlv->num_probes = cpu_to_le16((u16) num_probes);

                tlv_pos += sizeof(num_probes_tlv->header) +
                        le16_to_cpu(num_probes_tlv->header.len);

        }

        /* Append rates tlv */
        memset(rates, 0, sizeof(rates));

        rates_size = mwifiex_get_supported_rates(priv, rates);

        rates_tlv = (struct mwifiex_ie_types_rates_param_set *) tlv_pos;
        rates_tlv->header.type = cpu_to_le16(WLAN_EID_SUPP_RATES);
        rates_tlv->header.len = cpu_to_le16((u16) rates_size);
        memcpy(rates_tlv->rates, rates, rates_size);
        tlv_pos += sizeof(rates_tlv->header) + rates_size;

        dev_dbg(adapter->dev, "info: SCAN_CMD: Rates size = %d\n", rates_size);

        if (ISSUPP_11NENABLED(priv->adapter->fw_cap_info)
            && (priv->adapter->config_bands & BAND_GN
                || priv->adapter->config_bands & BAND_AN)) {
                ht_cap = (struct mwifiex_ie_types_htcap *) tlv_pos;
                memset(ht_cap, 0, sizeof(struct mwifiex_ie_types_htcap));
                ht_cap->header.type = cpu_to_le16(WLAN_EID_HT_CAPABILITY);
                ht_cap->header.len =
                                cpu_to_le16(sizeof(struct ieee80211_ht_cap));
                radio_type =
                        mwifiex_band_to_radio_type(priv->adapter->config_bands);
                mwifiex_fill_cap_info(priv, radio_type, ht_cap);
                tlv_pos += sizeof(struct mwifiex_ie_types_htcap);
        }

        /* Append vendor specific IE TLV */
        mwifiex_cmd_append_vsie_tlv(priv, MWIFIEX_VSIE_MASK_SCAN, &tlv_pos);

        /*
         * Set the output for the channel TLV to the address in the tlv buffer
         *   past any TLVs that were added in this function (SSID, num_probes).
         *   Channel TLVs will be added past this for each scan command,
         *   preserving the TLVs that were previously added.
         */
        *chan_list_out =
                (struct mwifiex_ie_types_chan_list_param_set *) tlv_pos;

        if (user_scan_in && user_scan_in->chan_list[0].chan_number) {

                dev_dbg(adapter->dev, "info: Scan: Using supplied channel list\n");

                for (chan_idx = 0;
                     chan_idx < MWIFIEX_USER_SCAN_CHAN_MAX
                     && user_scan_in->chan_list[chan_idx].chan_number;
                     chan_idx++) {

                        channel = user_scan_in->chan_list[chan_idx].chan_number;
                        (scan_chan_list + chan_idx)->chan_number = channel;

                        radio_type =
                                user_scan_in->chan_list[chan_idx].radio_type;
                        (scan_chan_list + chan_idx)->radio_type = radio_type;

                        scan_type = user_scan_in->chan_list[chan_idx].scan_type;

                        if (scan_type == MWIFIEX_SCAN_TYPE_PASSIVE)
                                (scan_chan_list +
                                 chan_idx)->chan_scan_mode_bitmap
                                        |= MWIFIEX_PASSIVE_SCAN;
                        else
                                (scan_chan_list +
                                 chan_idx)->chan_scan_mode_bitmap
                                        &= ~MWIFIEX_PASSIVE_SCAN;

                        if (user_scan_in->chan_list[chan_idx].scan_time) {
                                scan_dur = (u16) user_scan_in->
                                        chan_list[chan_idx].scan_time;
                        } else {
                                if (scan_type == MWIFIEX_SCAN_TYPE_PASSIVE)
                                        scan_dur = adapter->passive_scan_time;
                                else if (*filtered_scan)
                                        scan_dur = adapter->specific_scan_time;
                                else
                                        scan_dur = adapter->active_scan_time;
                        }

                        (scan_chan_list + chan_idx)->min_scan_time =
                                cpu_to_le16(scan_dur);
                        (scan_chan_list + chan_idx)->max_scan_time =
                                cpu_to_le16(scan_dur);
                }

                /* Check if we are only scanning the current channel */
                if ((chan_idx == 1)
                    && (user_scan_in->chan_list[0].chan_number
                        == priv->curr_bss_params.bss_descriptor.channel)) {
                        *scan_current_only = true;
                        dev_dbg(adapter->dev,
                                "info: Scan: Scanning current channel only\n");
                }

        } else {
                dev_dbg(adapter->dev,
                                "info: Scan: Creating full region channel list\n");
                mwifiex_scan_create_channel_list(priv, user_scan_in,
                                                 scan_chan_list,
                                                 *filtered_scan);
        }
}

/*
 * This function inspects the scan response buffer for pointers to
 * expected TLVs.
 *
 * TLVs can be included at the end of the scan response BSS information.
 *
 * Data in the buffer is parsed pointers to TLVs that can potentially
 * be passed back in the response.
 */
static void
mwifiex_ret_802_11_scan_get_tlv_ptrs(struct mwifiex_adapter *adapter,
                                     struct mwifiex_ie_types_data *tlv,
                                     u32 tlv_buf_size, u32 req_tlv_type,
                                     struct mwifiex_ie_types_data **tlv_data)
{
        struct mwifiex_ie_types_data *current_tlv;
        u32 tlv_buf_left;
        u32 tlv_type;
        u32 tlv_len;

        current_tlv = tlv;
        tlv_buf_left = tlv_buf_size;
        *tlv_data = NULL;

        dev_dbg(adapter->dev, "info: SCAN_RESP: tlv_buf_size = %d\n",
                                                tlv_buf_size);

        while (tlv_buf_left >= sizeof(struct mwifiex_ie_types_header)) {

                tlv_type = le16_to_cpu(current_tlv->header.type);
                tlv_len = le16_to_cpu(current_tlv->header.len);

                if (sizeof(tlv->header) + tlv_len > tlv_buf_left) {
                        dev_err(adapter->dev, "SCAN_RESP: TLV buffer corrupt\n");
                        break;
                }

                if (req_tlv_type == tlv_type) {
                        switch (tlv_type) {
                        case TLV_TYPE_TSFTIMESTAMP:
                                dev_dbg(adapter->dev, "info: SCAN_RESP: TSF "
                                        "timestamp TLV, len = %d\n", tlv_len);
                                *tlv_data = (struct mwifiex_ie_types_data *)
                                        current_tlv;
                                break;
                        case TLV_TYPE_CHANNELBANDLIST:
                                dev_dbg(adapter->dev, "info: SCAN_RESP: channel"
                                        " band list TLV, len = %d\n", tlv_len);
                                *tlv_data = (struct mwifiex_ie_types_data *)
                                        current_tlv;
                                break;
                        default:
                                dev_err(adapter->dev,
                                        "SCAN_RESP: unhandled TLV = %d\n",
                                       tlv_type);
                                /* Give up, this seems corrupted */
                                return;
                        }
                }

                if (*tlv_data)
                        break;


                tlv_buf_left -= (sizeof(tlv->header) + tlv_len);
                current_tlv =
                        (struct mwifiex_ie_types_data *) (current_tlv->data +
                                                          tlv_len);

        }                       /* while */
}

/*
 * This function interprets a BSS scan response returned from the firmware.
 *
 * The various fixed fields and IEs are parsed and passed back for a BSS
 * probe response or beacon from scan command. Information is recorded as
 * needed in the scan table for that entry.
 *
 * The following IE types are recognized and parsed -
 *      - SSID
 *      - Supported rates
 *      - FH parameters set
 *      - DS parameters set
 *      - CF parameters set
 *      - IBSS parameters set
 *      - ERP information
 *      - Extended supported rates
 *      - Vendor specific (221)
 *      - RSN IE
 *      - WAPI IE
 *      - HT capability
 *      - HT operation
 *      - BSS Coexistence 20/40
 *      - Extended capability
 *      - Overlapping BSS scan parameters
 */
static int
mwifiex_interpret_bss_desc_with_ie(struct mwifiex_adapter *adapter,
                                   struct mwifiex_bssdescriptor *bss_entry,
                                   u8 **beacon_info, u32 *bytes_left)
{
        int ret = 0;
        u8 element_id;
        struct ieee_types_fh_param_set *fh_param_set;
        struct ieee_types_ds_param_set *ds_param_set;
        struct ieee_types_cf_param_set *cf_param_set;
        struct ieee_types_ibss_param_set *ibss_param_set;
        __le16 beacon_interval;
        __le16 capabilities;
        u8 *current_ptr;
        u8 *rate;
        u8 element_len;
        u16 total_ie_len;
        u8 bytes_to_copy;
        u8 rate_size;
        u16 beacon_size;
        u8 found_data_rate_ie;
        u32 bytes_left_for_current_beacon;
        struct ieee_types_vendor_specific *vendor_ie;
        const u8 wpa_oui[4] = { 0x00, 0x50, 0xf2, 0x01 };
        const u8 wmm_oui[4] = { 0x00, 0x50, 0xf2, 0x02 };

        found_data_rate_ie = false;
        rate_size = 0;
        beacon_size = 0;

        if (*bytes_left >= sizeof(beacon_size)) {
                /* Extract & convert beacon size from the command buffer */
                memcpy(&beacon_size, *beacon_info, sizeof(beacon_size));
                *bytes_left -= sizeof(beacon_size);
                *beacon_info += sizeof(beacon_size);
        }

        if (!beacon_size || beacon_size > *bytes_left) {
                *beacon_info += *bytes_left;
                *bytes_left = 0;
                return -1;
        }

        /* Initialize the current working beacon pointer for this BSS
           iteration */
        current_ptr = *beacon_info;

        /* Advance the return beacon pointer past the current beacon */
        *beacon_info += beacon_size;
        *bytes_left -= beacon_size;

        bytes_left_for_current_beacon = beacon_size;

        memcpy(bss_entry->mac_address, current_ptr, ETH_ALEN);
        dev_dbg(adapter->dev, "info: InterpretIE: AP MAC Addr: %pM\n",
                                                bss_entry->mac_address);

        current_ptr += ETH_ALEN;
        bytes_left_for_current_beacon -= ETH_ALEN;

        if (bytes_left_for_current_beacon < 12) {
                dev_err(adapter->dev, "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 */
        bss_entry->rssi = (s32) (*current_ptr);
        dev_dbg(adapter->dev, "info: InterpretIE: RSSI=%02X\n", *current_ptr);
        current_ptr += 1;
        bytes_left_for_current_beacon -= 1;

        /*
         *  The RSSI is not part of the beacon/probe response.  After we have
         *    advanced current_ptr past the RSSI field, save the remaining
         *    data for use at the application layer
         */
        bss_entry->beacon_buf = current_ptr;
        bss_entry->beacon_buf_size = bytes_left_for_current_beacon;

        /* Time stamp is 8 bytes long */
        memcpy(bss_entry->time_stamp, current_ptr, 8);
        current_ptr += 8;
        bytes_left_for_current_beacon -= 8;

        /* Beacon interval is 2 bytes long */
        memcpy(&beacon_interval, current_ptr, 2);
        bss_entry->beacon_period = le16_to_cpu(beacon_interval);
        current_ptr += 2;
        bytes_left_for_current_beacon -= 2;

        /* Capability information is 2 bytes long */
        memcpy(&capabilities, current_ptr, 2);
        dev_dbg(adapter->dev, "info: InterpretIE: capabilities=0x%X\n",
               capabilities);
        bss_entry->cap_info_bitmap = le16_to_cpu(capabilities);
        current_ptr += 2;
        bytes_left_for_current_beacon -= 2;

        /* Rest of the current buffer are IE's */
        dev_dbg(adapter->dev, "info: InterpretIE: IELength for this AP = %d\n",
               bytes_left_for_current_beacon);

        if (bss_entry->cap_info_bitmap & WLAN_CAPABILITY_PRIVACY) {
                dev_dbg(adapter->dev, "info: InterpretIE: AP WEP enabled\n");
                bss_entry->privacy = MWIFIEX_802_11_PRIV_FILTER_8021X_WEP;
        } else {
                bss_entry->privacy = MWIFIEX_802_11_PRIV_FILTER_ACCEPT_ALL;
        }

        if (bss_entry->cap_info_bitmap & WLAN_CAPABILITY_IBSS)
                bss_entry->bss_mode = NL80211_IFTYPE_ADHOC;
        else
                bss_entry->bss_mode = NL80211_IFTYPE_STATION;


        /* Process variable IE */
        while (bytes_left_for_current_beacon >= 2) {
                element_id = *current_ptr;
                element_len = *(current_ptr + 1);
                total_ie_len = element_len + sizeof(struct ieee_types_header);

                if (bytes_left_for_current_beacon < total_ie_len) {
                        dev_err(adapter->dev, "err: InterpretIE: in processing"
                                " IE, bytes left < IE length\n");
                        bytes_left_for_current_beacon = 0;
                        ret = -1;
                        continue;
                }
                switch (element_id) {
                case WLAN_EID_SSID:
                        bss_entry->ssid.ssid_len = element_len;
                        memcpy(bss_entry->ssid.ssid, (current_ptr + 2),
                               element_len);
                        dev_dbg(adapter->dev, "info: InterpretIE: ssid: %-32s\n",
                               bss_entry->ssid.ssid);
                        break;

                case WLAN_EID_SUPP_RATES:
                        memcpy(bss_entry->data_rates, current_ptr + 2,
                               element_len);
                        memcpy(bss_entry->supported_rates, current_ptr + 2,
                               element_len);
                        rate_size = element_len;
                        found_data_rate_ie = true;
                        break;

                case WLAN_EID_FH_PARAMS:
                        fh_param_set =
                                (struct ieee_types_fh_param_set *) current_ptr;
                        memcpy(&bss_entry->phy_param_set.fh_param_set,
                               fh_param_set,
                               sizeof(struct ieee_types_fh_param_set));
                        break;

                case WLAN_EID_DS_PARAMS:
                        ds_param_set =
                                (struct ieee_types_ds_param_set *) current_ptr;

                        bss_entry->channel = ds_param_set->current_chan;

                        memcpy(&bss_entry->phy_param_set.ds_param_set,
                               ds_param_set,
                               sizeof(struct ieee_types_ds_param_set));
                        break;

                case WLAN_EID_CF_PARAMS:
                        cf_param_set =
                                (struct ieee_types_cf_param_set *) current_ptr;
                        memcpy(&bss_entry->ss_param_set.cf_param_set,
                               cf_param_set,
                               sizeof(struct ieee_types_cf_param_set));
                        break;

                case WLAN_EID_IBSS_PARAMS:
                        ibss_param_set =
                                (struct ieee_types_ibss_param_set *)
                                current_ptr;
                        memcpy(&bss_entry->ss_param_set.ibss_param_set,
                               ibss_param_set,
                               sizeof(struct ieee_types_ibss_param_set));
                        break;

                case WLAN_EID_ERP_INFO:
                        bss_entry->erp_flags = *(current_ptr + 2);
                        break;

                case WLAN_EID_EXT_SUPP_RATES:
                        /*
                         * Only process extended supported rate
                         * if data rate is already found.
                         * Data rate IE should come before
                         * extended supported rate IE
                         */
                        if (found_data_rate_ie) {
                                if ((element_len + rate_size) >
                                    MWIFIEX_SUPPORTED_RATES)
                                        bytes_to_copy =
                                                (MWIFIEX_SUPPORTED_RATES -
                                                 rate_size);
                                else
                                        bytes_to_copy = element_len;

                                rate = (u8 *) bss_entry->data_rates;
                                rate += rate_size;
                                memcpy(rate, current_ptr + 2, bytes_to_copy);

                                rate = (u8 *) bss_entry->supported_rates;
                                rate += rate_size;
                                memcpy(rate, current_ptr + 2, bytes_to_copy);
                        }
                        break;

                case WLAN_EID_VENDOR_SPECIFIC:
                        vendor_ie = (struct ieee_types_vendor_specific *)
                                        current_ptr;

                        if (!memcmp
                            (vendor_ie->vend_hdr.oui, wpa_oui,
                             sizeof(wpa_oui))) {
                                bss_entry->bcn_wpa_ie =
                                        (struct ieee_types_vendor_specific *)
                                        current_ptr;
                                bss_entry->wpa_offset = (u16) (current_ptr -
                                                        bss_entry->beacon_buf);
                        } else if (!memcmp(vendor_ie->vend_hdr.oui, wmm_oui,
                                    sizeof(wmm_oui))) {
                                if (total_ie_len ==
                                    sizeof(struct ieee_types_wmm_parameter)
                                    || total_ie_len ==
                                    sizeof(struct ieee_types_wmm_info))
                                        /*
                                         * Only accept and copy the WMM IE if
                                         * it matches the size expected for the
                                         * WMM Info IE or the WMM Parameter IE.
                                         */
                                        memcpy((u8 *) &bss_entry->wmm_ie,
                                               current_ptr, total_ie_len);
                        }
                        break;
                case WLAN_EID_RSN:
                        bss_entry->bcn_rsn_ie =
                                (struct ieee_types_generic *) current_ptr;
                        bss_entry->rsn_offset = (u16) (current_ptr -
                                                        bss_entry->beacon_buf);
                        break;
                case WLAN_EID_BSS_AC_ACCESS_DELAY:
                        bss_entry->bcn_wapi_ie =
                                (struct ieee_types_generic *) current_ptr;
                        bss_entry->wapi_offset = (u16) (current_ptr -
                                                        bss_entry->beacon_buf);
                        break;
                case WLAN_EID_HT_CAPABILITY:
                        bss_entry->bcn_ht_cap = (struct ieee80211_ht_cap *)
                                        (current_ptr +
                                        sizeof(struct ieee_types_header));
                        bss_entry->ht_cap_offset = (u16) (current_ptr +
                                        sizeof(struct ieee_types_header) -
                                        bss_entry->beacon_buf);
                        break;
                case WLAN_EID_HT_INFORMATION:
                        bss_entry->bcn_ht_info = (struct ieee80211_ht_info *)
                                        (current_ptr +
                                        sizeof(struct ieee_types_header));
                        bss_entry->ht_info_offset = (u16) (current_ptr +
                                        sizeof(struct ieee_types_header) -
                                        bss_entry->beacon_buf);
                        break;
                case WLAN_EID_BSS_COEX_2040:
                        bss_entry->bcn_bss_co_2040 = (u8 *) (current_ptr +
                                        sizeof(struct ieee_types_header));
                        bss_entry->bss_co_2040_offset = (u16) (current_ptr +
                                        sizeof(struct ieee_types_header) -
                                                bss_entry->beacon_buf);
                        break;
                case WLAN_EID_EXT_CAPABILITY:
                        bss_entry->bcn_ext_cap = (u8 *) (current_ptr +
                                        sizeof(struct ieee_types_header));
                        bss_entry->ext_cap_offset = (u16) (current_ptr +
                                        sizeof(struct ieee_types_header) -
                                        bss_entry->beacon_buf);
                        break;
                case WLAN_EID_OVERLAP_BSS_SCAN_PARAM:
                        bss_entry->bcn_obss_scan =
                                (struct ieee_types_obss_scan_param *)
                                current_ptr;
                        bss_entry->overlap_bss_offset = (u16) (current_ptr -
                                                        bss_entry->beacon_buf);
                        break;
                default:
                        break;
                }

                current_ptr += element_len + 2;

                /* Need to account for IE ID and IE Len */
                bytes_left_for_current_beacon -= (element_len + 2);

        }       /* while (bytes_left_for_current_beacon > 2) */
        return ret;
}

/*
 * This function adjusts the pointers used in beacon buffers to reflect
 * shifts.
 *
 * The memory allocated for beacon buffers is of fixed sizes where all the
 * saved beacons must be stored. New beacons are added in the free portion
 * of this memory, space permitting; while duplicate beacon buffers are
 * placed at the same start location. However, since duplicate beacon
 * buffers may not match the size of the old one, all the following buffers
 * in the memory must be shifted to either make space, or to fill up freed
 * up space.
 *
 * This function is used to update the beacon buffer pointers that are past
 * an existing beacon buffer that is updated with a new one of different
 * size. The pointers are shifted by a fixed amount, either forward or
 * backward.
 *
 * the following pointers in every affected beacon buffers are changed, if
 * present -
 *      - WPA IE pointer
 *      - RSN IE pointer
 *      - WAPI IE pointer
 *      - HT capability IE pointer
 *      - HT information IE pointer
 *      - BSS coexistence 20/40 IE pointer
 *      - Extended capability IE pointer
 *      - Overlapping BSS scan parameter IE pointer
 */
static void
mwifiex_adjust_beacon_buffer_ptrs(struct mwifiex_private *priv, u8 advance,
                                  u8 *bcn_store, u32 rem_bcn_size,
                                  u32 num_of_ent)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        u32 adj_idx;
        for (adj_idx = 0; adj_idx < num_of_ent; adj_idx++) {
                if (adapter->scan_table[adj_idx].beacon_buf > bcn_store) {

                        if (advance)
                                adapter->scan_table[adj_idx].beacon_buf +=
                                        rem_bcn_size;
                        else
                                adapter->scan_table[adj_idx].beacon_buf -=
                                        rem_bcn_size;

                        if (adapter->scan_table[adj_idx].bcn_wpa_ie)
                                adapter->scan_table[adj_idx].bcn_wpa_ie =
                                (struct ieee_types_vendor_specific *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].wpa_offset);
                        if (adapter->scan_table[adj_idx].bcn_rsn_ie)
                                adapter->scan_table[adj_idx].bcn_rsn_ie =
                                (struct ieee_types_generic *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].rsn_offset);
                        if (adapter->scan_table[adj_idx].bcn_wapi_ie)
                                adapter->scan_table[adj_idx].bcn_wapi_ie =
                                (struct ieee_types_generic *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].wapi_offset);
                        if (adapter->scan_table[adj_idx].bcn_ht_cap)
                                adapter->scan_table[adj_idx].bcn_ht_cap =
                                (struct ieee80211_ht_cap *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].ht_cap_offset);

                        if (adapter->scan_table[adj_idx].bcn_ht_info)
                                adapter->scan_table[adj_idx].bcn_ht_info =
                                (struct ieee80211_ht_info *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].ht_info_offset);
                        if (adapter->scan_table[adj_idx].bcn_bss_co_2040)
                                adapter->scan_table[adj_idx].bcn_bss_co_2040 =
                                (u8 *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                               adapter->scan_table[adj_idx].bss_co_2040_offset);
                        if (adapter->scan_table[adj_idx].bcn_ext_cap)
                                adapter->scan_table[adj_idx].bcn_ext_cap =
                                (u8 *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                                 adapter->scan_table[adj_idx].ext_cap_offset);
                        if (adapter->scan_table[adj_idx].bcn_obss_scan)
                                adapter->scan_table[adj_idx].bcn_obss_scan =
                                (struct ieee_types_obss_scan_param *)
                                (adapter->scan_table[adj_idx].beacon_buf +
                               adapter->scan_table[adj_idx].overlap_bss_offset);
                }
        }
}

/*
 * This function updates the pointers used in beacon buffer for given bss
 * descriptor to reflect shifts
 *
 * Following pointers are updated
 *      - WPA IE pointer
 *      - RSN IE pointer
 *      - WAPI IE pointer
 *      - HT capability IE pointer
 *      - HT information IE pointer
 *      - BSS coexistence 20/40 IE pointer
 *      - Extended capability IE pointer
 *      - Overlapping BSS scan parameter IE pointer
 */
static void
mwifiex_update_beacon_buffer_ptrs(struct mwifiex_bssdescriptor *beacon)
{
        if (beacon->bcn_wpa_ie)
                beacon->bcn_wpa_ie = (struct ieee_types_vendor_specific *)
                        (beacon->beacon_buf + beacon->wpa_offset);
        if (beacon->bcn_rsn_ie)
                beacon->bcn_rsn_ie = (struct ieee_types_generic *)
                        (beacon->beacon_buf + beacon->rsn_offset);
        if (beacon->bcn_wapi_ie)
                beacon->bcn_wapi_ie = (struct ieee_types_generic *)
                        (beacon->beacon_buf + beacon->wapi_offset);
        if (beacon->bcn_ht_cap)
                beacon->bcn_ht_cap = (struct ieee80211_ht_cap *)
                        (beacon->beacon_buf + beacon->ht_cap_offset);
        if (beacon->bcn_ht_info)
                beacon->bcn_ht_info = (struct ieee80211_ht_info *)
                        (beacon->beacon_buf + beacon->ht_info_offset);
        if (beacon->bcn_bss_co_2040)
                beacon->bcn_bss_co_2040 = (u8 *) (beacon->beacon_buf +
                        beacon->bss_co_2040_offset);
        if (beacon->bcn_ext_cap)
                beacon->bcn_ext_cap = (u8 *) (beacon->beacon_buf +
                        beacon->ext_cap_offset);
        if (beacon->bcn_obss_scan)
                beacon->bcn_obss_scan = (struct ieee_types_obss_scan_param *)
                        (beacon->beacon_buf + beacon->overlap_bss_offset);
}

/*
 * This function stores a beacon or probe response for a BSS returned
 * in the scan.
 *
 * This stores a new scan response or an update for a previous scan response.
 * New entries need to verify that they do not exceed the total amount of
 * memory allocated for the table.
 *
 * Replacement entries need to take into consideration the amount of space
 * currently allocated for the beacon/probe response and adjust the entry
 * as needed.
 *
 * A small amount of extra pad (SCAN_BEACON_ENTRY_PAD) is generally reserved
 * for an entry in case it is a beacon since a probe response for the
 * network will by larger per the standard.  This helps to reduce the
 * amount of memory copying to fit a new probe response into an entry
 * already occupied by a network's previously stored beacon.
 */
static void
mwifiex_ret_802_11_scan_store_beacon(struct mwifiex_private *priv,
                                     u32 beacon_idx, u32 num_of_ent,
                                     struct mwifiex_bssdescriptor *new_beacon)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        u8 *bcn_store;
        u32 new_bcn_size;
        u32 old_bcn_size;
        u32 bcn_space;

        if (adapter->scan_table[beacon_idx].beacon_buf) {

                new_bcn_size = new_beacon->beacon_buf_size;
                old_bcn_size = adapter->scan_table[beacon_idx].beacon_buf_size;
                bcn_space = adapter->scan_table[beacon_idx].beacon_buf_size_max;
                bcn_store = adapter->scan_table[beacon_idx].beacon_buf;

                /* Set the max to be the same as current entry unless changed
                   below */
                new_beacon->beacon_buf_size_max = bcn_space;
                if (new_bcn_size == old_bcn_size) {
                        /*
                         * Beacon is the same size as the previous entry.
                         *   Replace the previous contents with the scan result
                         */
                        memcpy(bcn_store, new_beacon->beacon_buf,
                               new_beacon->beacon_buf_size);

                } else if (new_bcn_size <= bcn_space) {
                        /*
                         * New beacon size will fit in the amount of space
                         *   we have previously allocated for it
                         */

                        /* Copy the new beacon buffer entry over the old one */
                        memcpy(bcn_store, new_beacon->beacon_buf, new_bcn_size);

                        /*
                         *  If the old beacon size was less than the maximum
                         *  we had alloted for the entry, and the new entry
                         *  is even smaller, reset the max size to the old
                         *  beacon entry and compress the storage space
                         *  (leaving a new pad space of (old_bcn_size -
                         *  new_bcn_size).
                         */
                        if (old_bcn_size < bcn_space
                            && new_bcn_size <= old_bcn_size) {
                                /*
                                 * Old Beacon size is smaller than the alloted
                                 * storage size. Shrink the alloted storage
                                 * space.
                                 */
                                dev_dbg(adapter->dev, "info: AppControl:"
                                        " smaller duplicate beacon "
                                       "(%d), old = %d, new = %d, space = %d,"
                                       "left = %d\n",
                                       beacon_idx, old_bcn_size, new_bcn_size,
                                       bcn_space,
                                       (int)(sizeof(adapter->bcn_buf) -
                                        (adapter->bcn_buf_end -
                                         adapter->bcn_buf)));

                                /*
                                 *  memmove (since the memory overlaps) the
                                 *  data after the beacon we just stored to the
                                 *  end of the current beacon.  This cleans up
                                 *  any unused space the old larger beacon was
                                 *  using in the buffer
                                 */
                                memmove(bcn_store + old_bcn_size,
                                        bcn_store + bcn_space,
                                        adapter->bcn_buf_end - (bcn_store +
                                                                   bcn_space));

                                /*
                                 * Decrement the end pointer by the difference
                                 * between the old larger size and the new
                                 * smaller size since we are using less space
                                 * due to the new beacon being smaller
                                 */
                                adapter->bcn_buf_end -=
                                        (bcn_space - old_bcn_size);

                                /* Set the maximum storage size to the old
                                   beacon size */
                                new_beacon->beacon_buf_size_max = old_bcn_size;

                                /* Adjust beacon buffer pointers that are past
                                   the current */
                                mwifiex_adjust_beacon_buffer_ptrs(priv, 0,
                                        bcn_store, (bcn_space - old_bcn_size),
                                        num_of_ent);
                        }
                } else if (adapter->bcn_buf_end + (new_bcn_size - bcn_space)
                           < (adapter->bcn_buf + sizeof(adapter->bcn_buf))) {
                        /*
                         * Beacon is larger than space previously allocated
                         * (bcn_space) and there is enough space left in the
                         * beaconBuffer to store the additional data
                         */
                        dev_dbg(adapter->dev, "info: AppControl:"
                                " larger duplicate beacon (%d), "
                               "old = %d, new = %d, space = %d, left = %d\n",
                               beacon_idx, old_bcn_size, new_bcn_size,
                               bcn_space,
                               (int)(sizeof(adapter->bcn_buf) -
                                (adapter->bcn_buf_end -
                                 adapter->bcn_buf)));

                        /*
                         * memmove (since the memory overlaps) the data
                         *  after the beacon we just stored to the end of
                         *  the current beacon.  This moves the data for
                         *  the beacons after this further in memory to
                         *  make space for the new larger beacon we are
                         *  about to copy in.
                         */
                        memmove(bcn_store + new_bcn_size,
                                bcn_store + bcn_space,
                                adapter->bcn_buf_end - (bcn_store + bcn_space));

                        /* Copy the new beacon buffer entry over the old one */
                        memcpy(bcn_store, new_beacon->beacon_buf, new_bcn_size);

                        /* Move the beacon end pointer by the amount of new
                           beacon data we are adding */
                        adapter->bcn_buf_end += (new_bcn_size - bcn_space);

                        /*
                         * This entry is bigger than the alloted max space
                         *  previously reserved.  Increase the max space to
                         *  be equal to the new beacon size
                         */
                        new_beacon->beacon_buf_size_max = new_bcn_size;

                        /* Adjust beacon buffer pointers that are past the
                           current */
                        mwifiex_adjust_beacon_buffer_ptrs(priv, 1, bcn_store,
                                                (new_bcn_size - bcn_space),
                                                num_of_ent);
                } else {
                        /*
                         * Beacon is larger than the previously allocated space,
                         * but there is not enough free space to store the
                         * additional data.
                         */
                        dev_err(adapter->dev, "AppControl: larger duplicate "
                                " beacon (%d), old = %d new = %d, space = %d,"
                                " left = %d\n", beacon_idx, old_bcn_size,
                                new_bcn_size, bcn_space,
                                (int)(sizeof(adapter->bcn_buf) -
                                (adapter->bcn_buf_end - adapter->bcn_buf)));

                        /* Storage failure, keep old beacon intact */
                        new_beacon->beacon_buf_size = old_bcn_size;
                        if (new_beacon->bcn_wpa_ie)
                                new_beacon->wpa_offset =
                                        adapter->scan_table[beacon_idx].
                                        wpa_offset;
                        if (new_beacon->bcn_rsn_ie)
                                new_beacon->rsn_offset =
                                        adapter->scan_table[beacon_idx].
                                        rsn_offset;
                        if (new_beacon->bcn_wapi_ie)
                                new_beacon->wapi_offset =
                                        adapter->scan_table[beacon_idx].
                                        wapi_offset;
                        if (new_beacon->bcn_ht_cap)
                                new_beacon->ht_cap_offset =
                                        adapter->scan_table[beacon_idx].
                                        ht_cap_offset;
                        if (new_beacon->bcn_ht_info)
                                new_beacon->ht_info_offset =
                                        adapter->scan_table[beacon_idx].
                                        ht_info_offset;
                        if (new_beacon->bcn_bss_co_2040)
                                new_beacon->bss_co_2040_offset =
                                        adapter->scan_table[beacon_idx].
                                        bss_co_2040_offset;
                        if (new_beacon->bcn_ext_cap)
                                new_beacon->ext_cap_offset =
                                        adapter->scan_table[beacon_idx].
                                        ext_cap_offset;
                        if (new_beacon->bcn_obss_scan)
                                new_beacon->overlap_bss_offset =
                                        adapter->scan_table[beacon_idx].
                                        overlap_bss_offset;
                }
                /* Point the new entry to its permanent storage space */
                new_beacon->beacon_buf = bcn_store;
                mwifiex_update_beacon_buffer_ptrs(new_beacon);
        } else {
                /*
                 * No existing beacon data exists for this entry, check to see
                 *   if we can fit it in the remaining space
                 */
                if (adapter->bcn_buf_end + new_beacon->beacon_buf_size +
                    SCAN_BEACON_ENTRY_PAD < (adapter->bcn_buf +
                                             sizeof(adapter->bcn_buf))) {

                        /*
                         * Copy the beacon buffer data from the local entry to
                         * the adapter dev struct buffer space used to store
                         * the raw beacon data for each entry in the scan table
                         */
                        memcpy(adapter->bcn_buf_end, new_beacon->beacon_buf,
                               new_beacon->beacon_buf_size);

                        /* Update the beacon ptr to point to the table save
                           area */
                        new_beacon->beacon_buf = adapter->bcn_buf_end;
                        new_beacon->beacon_buf_size_max =
                                (new_beacon->beacon_buf_size +
                                 SCAN_BEACON_ENTRY_PAD);

                        mwifiex_update_beacon_buffer_ptrs(new_beacon);

                        /* Increment the end pointer by the size reserved */
                        adapter->bcn_buf_end += new_beacon->beacon_buf_size_max;

                        dev_dbg(adapter->dev, "info: AppControl: beacon[%02d]"
                                " sz=%03d, used = %04d, left = %04d\n",
                               beacon_idx,
                               new_beacon->beacon_buf_size,
                               (int)(adapter->bcn_buf_end - adapter->bcn_buf),
                               (int)(sizeof(adapter->bcn_buf) -
                                (adapter->bcn_buf_end -
                                 adapter->bcn_buf)));
                } else {
                        /* No space for new beacon */
                        dev_dbg(adapter->dev, "info: AppControl: no space for"
                                " beacon (%d): %pM sz=%03d, left=%03d\n",
                               beacon_idx, new_beacon->mac_address,
                               new_beacon->beacon_buf_size,
                               (int)(sizeof(adapter->bcn_buf) -
                                (adapter->bcn_buf_end -
                                 adapter->bcn_buf)));

                        /* Storage failure; clear storage records for this
                           bcn */
                        new_beacon->beacon_buf = NULL;
                        new_beacon->beacon_buf_size = 0;
                        new_beacon->beacon_buf_size_max = 0;
                        new_beacon->bcn_wpa_ie = NULL;
                        new_beacon->wpa_offset = 0;
                        new_beacon->bcn_rsn_ie = NULL;
                        new_beacon->rsn_offset = 0;
                        new_beacon->bcn_wapi_ie = NULL;
                        new_beacon->wapi_offset = 0;
                        new_beacon->bcn_ht_cap = NULL;
                        new_beacon->ht_cap_offset = 0;
                        new_beacon->bcn_ht_info = NULL;
                        new_beacon->ht_info_offset = 0;
                        new_beacon->bcn_bss_co_2040 = NULL;
                        new_beacon->bss_co_2040_offset = 0;
                        new_beacon->bcn_ext_cap = NULL;
                        new_beacon->ext_cap_offset = 0;
                        new_beacon->bcn_obss_scan = NULL;
                        new_beacon->overlap_bss_offset = 0;
                }
        }
}

/*
 * This function restores a beacon buffer of the current BSS descriptor.
 */
static void mwifiex_restore_curr_bcn(struct mwifiex_private *priv)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_bssdescriptor *curr_bss =
                &priv->curr_bss_params.bss_descriptor;
        unsigned long flags;

        if (priv->curr_bcn_buf &&
            ((adapter->bcn_buf_end + priv->curr_bcn_size) <
             (adapter->bcn_buf + sizeof(adapter->bcn_buf)))) {
                spin_lock_irqsave(&priv->curr_bcn_buf_lock, flags);

                /* restore the current beacon buffer */
                memcpy(adapter->bcn_buf_end, priv->curr_bcn_buf,
                       priv->curr_bcn_size);
                curr_bss->beacon_buf = adapter->bcn_buf_end;
                curr_bss->beacon_buf_size = priv->curr_bcn_size;
                adapter->bcn_buf_end += priv->curr_bcn_size;

                /* adjust the pointers in the current BSS descriptor */
                if (curr_bss->bcn_wpa_ie)
                        curr_bss->bcn_wpa_ie =
                                (struct ieee_types_vendor_specific *)
                                (curr_bss->beacon_buf +
                                 curr_bss->wpa_offset);

                if (curr_bss->bcn_rsn_ie)
                        curr_bss->bcn_rsn_ie = (struct ieee_types_generic *)
                                (curr_bss->beacon_buf +
                                 curr_bss->rsn_offset);

                if (curr_bss->bcn_ht_cap)
                        curr_bss->bcn_ht_cap = (struct ieee80211_ht_cap *)
                                (curr_bss->beacon_buf +
                                 curr_bss->ht_cap_offset);

                if (curr_bss->bcn_ht_info)
                        curr_bss->bcn_ht_info = (struct ieee80211_ht_info *)
                                (curr_bss->beacon_buf +
                                 curr_bss->ht_info_offset);

                if (curr_bss->bcn_bss_co_2040)
                        curr_bss->bcn_bss_co_2040 =
                                (u8 *) (curr_bss->beacon_buf +
                                 curr_bss->bss_co_2040_offset);

                if (curr_bss->bcn_ext_cap)
                        curr_bss->bcn_ext_cap = (u8 *) (curr_bss->beacon_buf +
                                 curr_bss->ext_cap_offset);

                if (curr_bss->bcn_obss_scan)
                        curr_bss->bcn_obss_scan =
                                (struct ieee_types_obss_scan_param *)
                                (curr_bss->beacon_buf +
                                 curr_bss->overlap_bss_offset);

                spin_unlock_irqrestore(&priv->curr_bcn_buf_lock, flags);

                dev_dbg(adapter->dev, "info: current beacon restored %d\n",
                       priv->curr_bcn_size);
        } else {
                dev_warn(adapter->dev,
                        "curr_bcn_buf not saved or bcn_buf has no space\n");
        }
}

/*
 * This function post processes the scan table after a new scan command has
 * completed.
 *
 * It inspects each entry of the scan table and tries to find an entry that
 * matches with our current associated/joined network from the scan. If
 * one is found, the stored copy of the BSS descriptor of our current network
 * is updated.
 *
 * It also debug dumps the current scan table contents after processing is over.
 */
static void
mwifiex_process_scan_results(struct mwifiex_private *priv)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        s32 j;
        u32 i;
        unsigned long flags;

        if (priv->media_connected) {

                j = mwifiex_find_ssid_in_list(priv, &priv->curr_bss_params.
                                              bss_descriptor.ssid,
                                              priv->curr_bss_params.
                                              bss_descriptor.mac_address,
                                              priv->bss_mode);

                if (j >= 0) {
                        spin_lock_irqsave(&priv->curr_bcn_buf_lock, flags);
                        priv->curr_bss_params.bss_descriptor.bcn_wpa_ie = NULL;
                        priv->curr_bss_params.bss_descriptor.wpa_offset = 0;
                        priv->curr_bss_params.bss_descriptor.bcn_rsn_ie = NULL;
                        priv->curr_bss_params.bss_descriptor.rsn_offset = 0;
                        priv->curr_bss_params.bss_descriptor.bcn_wapi_ie = NULL;
                        priv->curr_bss_params.bss_descriptor.wapi_offset = 0;
                        priv->curr_bss_params.bss_descriptor.bcn_ht_cap = NULL;
                        priv->curr_bss_params.bss_descriptor.ht_cap_offset =
                                0;
                        priv->curr_bss_params.bss_descriptor.bcn_ht_info = NULL;
                        priv->curr_bss_params.bss_descriptor.ht_info_offset =
                                0;
                        priv->curr_bss_params.bss_descriptor.bcn_bss_co_2040 =
                                NULL;
                        priv->curr_bss_params.bss_descriptor.
                                bss_co_2040_offset = 0;
                        priv->curr_bss_params.bss_descriptor.bcn_ext_cap = NULL;
                        priv->curr_bss_params.bss_descriptor.ext_cap_offset = 0;
                        priv->curr_bss_params.bss_descriptor.
                                bcn_obss_scan = NULL;
                        priv->curr_bss_params.bss_descriptor.
                                overlap_bss_offset = 0;
                        priv->curr_bss_params.bss_descriptor.beacon_buf = NULL;
                        priv->curr_bss_params.bss_descriptor.beacon_buf_size =
                                0;
                        priv->curr_bss_params.bss_descriptor.
                                beacon_buf_size_max = 0;

                        dev_dbg(adapter->dev, "info: Found current ssid/bssid"
                                " in list @ index #%d\n", j);
                        /* Make a copy of current BSSID descriptor */
                        memcpy(&priv->curr_bss_params.bss_descriptor,
                               &adapter->scan_table[j],
                               sizeof(priv->curr_bss_params.bss_descriptor));

                        mwifiex_save_curr_bcn(priv);
                        spin_unlock_irqrestore(&priv->curr_bcn_buf_lock, flags);

                } else {
                        mwifiex_restore_curr_bcn(priv);
                }
        }

        for (i = 0; i < adapter->num_in_scan_table; i++)
                dev_dbg(adapter->dev, "info: scan:(%02d) %pM "
                       "RSSI[%03d], SSID[%s]\n",
                       i, adapter->scan_table[i].mac_address,
                       (s32) adapter->scan_table[i].rssi,
                       adapter->scan_table[i].ssid.ssid);
}

/*
 * This function converts radio type scan parameter to a band configuration
 * to be used in join command.
 */
static u8
mwifiex_radio_type_to_band(u8 radio_type)
{
        switch (radio_type) {
        case HostCmd_SCAN_RADIO_TYPE_A:
                return BAND_A;
        case HostCmd_SCAN_RADIO_TYPE_BG:
        default:
                return BAND_G;
        }
}

/*
 * This function deletes a specific indexed entry from the scan table.
 *
 * This also compacts the remaining entries and adjusts any buffering
 * of beacon/probe response data if needed.
 */
static void
mwifiex_scan_delete_table_entry(struct mwifiex_private *priv, s32 table_idx)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        u32 del_idx;
        u32 beacon_buf_adj;
        u8 *beacon_buf;

        /*
         * Shift the saved beacon buffer data for the scan table back over the
         *   entry being removed.  Update the end of buffer pointer.  Save the
         *   deleted buffer allocation size for pointer adjustments for entries
         *   compacted after the deleted index.
         */
        beacon_buf_adj = adapter->scan_table[table_idx].beacon_buf_size_max;

        dev_dbg(adapter->dev, "info: Scan: Delete Entry %d, beacon buffer "
                "removal = %d bytes\n", table_idx, beacon_buf_adj);

        /* Check if the table entry had storage allocated for its beacon */
        if (beacon_buf_adj) {
                beacon_buf = adapter->scan_table[table_idx].beacon_buf;

                /*
                 * Remove the entry's buffer space, decrement the table end
                 * pointer by the amount we are removing
                 */
                adapter->bcn_buf_end -= beacon_buf_adj;

                dev_dbg(adapter->dev, "info: scan: delete entry %d,"
                        " compact data: %p <- %p (sz = %d)\n",
                       table_idx, beacon_buf,
                       beacon_buf + beacon_buf_adj,
                       (int)(adapter->bcn_buf_end - beacon_buf));

                /*
                 * Compact data storage.  Copy all data after the deleted
                 * entry's end address (beacon_buf + beacon_buf_adj) back
                 * to the original start address (beacon_buf).
                 *
                 * Scan table entries affected by the move will have their
                 * entry pointer adjusted below.
                 *
                 * Use memmove since the dest/src memory regions overlap.
                 */
                memmove(beacon_buf, beacon_buf + beacon_buf_adj,
                        adapter->bcn_buf_end - beacon_buf);
        }

        dev_dbg(adapter->dev,
                "info: Scan: Delete Entry %d, num_in_scan_table = %d\n",
               table_idx, adapter->num_in_scan_table);

        /* Shift all of the entries after the table_idx back by one, compacting
           the table and removing the requested entry */
        for (del_idx = table_idx; (del_idx + 1) < adapter->num_in_scan_table;
             del_idx++) {
                /* Copy the next entry over this one */
                memcpy(adapter->scan_table + del_idx,
                       adapter->scan_table + del_idx + 1,
                       sizeof(struct mwifiex_bssdescriptor));

                /*
                 * Adjust this entry's pointer to its beacon buffer based on
                 * the removed/compacted entry from the deleted index.  Don't
                 * decrement if the buffer pointer is NULL (no data stored for
                 * this entry).
                 */
                if (adapter->scan_table[del_idx].beacon_buf) {
                        adapter->scan_table[del_idx].beacon_buf -=
                                beacon_buf_adj;
                        if (adapter->scan_table[del_idx].bcn_wpa_ie)
                                adapter->scan_table[del_idx].bcn_wpa_ie =
                                        (struct ieee_types_vendor_specific *)
                                        (adapter->scan_table[del_idx].
                                         beacon_buf +
                                         adapter->scan_table[del_idx].
                                         wpa_offset);
                        if (adapter->scan_table[del_idx].bcn_rsn_ie)
                                adapter->scan_table[del_idx].bcn_rsn_ie =
                                        (struct ieee_types_generic *)
                                        (adapter->scan_table[del_idx].
                                         beacon_buf +
                                         adapter->scan_table[del_idx].
                                         rsn_offset);
                        if (adapter->scan_table[del_idx].bcn_wapi_ie)
                                adapter->scan_table[del_idx].bcn_wapi_ie =
                                        (struct ieee_types_generic *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                         wapi_offset);
                        if (adapter->scan_table[del_idx].bcn_ht_cap)
                                adapter->scan_table[del_idx].bcn_ht_cap =
                                        (struct ieee80211_ht_cap *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                          ht_cap_offset);

                        if (adapter->scan_table[del_idx].bcn_ht_info)
                                adapter->scan_table[del_idx].bcn_ht_info =
                                        (struct ieee80211_ht_info *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                          ht_info_offset);
                        if (adapter->scan_table[del_idx].bcn_bss_co_2040)
                                adapter->scan_table[del_idx].bcn_bss_co_2040 =
                                        (u8 *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                           bss_co_2040_offset);
                        if (adapter->scan_table[del_idx].bcn_ext_cap)
                                adapter->scan_table[del_idx].bcn_ext_cap =
                                        (u8 *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                             ext_cap_offset);
                        if (adapter->scan_table[del_idx].bcn_obss_scan)
                                adapter->scan_table[del_idx].
                                        bcn_obss_scan =
                                        (struct ieee_types_obss_scan_param *)
                                        (adapter->scan_table[del_idx].beacon_buf
                                         + adapter->scan_table[del_idx].
                                             overlap_bss_offset);
                }
        }

        /* The last entry is invalid now that it has been deleted or moved
           back */
        memset(adapter->scan_table + adapter->num_in_scan_table - 1,
               0x00, sizeof(struct mwifiex_bssdescriptor));

        adapter->num_in_scan_table--;
}

/*
 * This function deletes all occurrences of a given SSID from the scan table.
 *
 * This iterates through the scan table and deletes all entries that match
 * the given SSID. It also compacts the remaining scan table entries.
 */
static int
mwifiex_scan_delete_ssid_table_entry(struct mwifiex_private *priv,
                                     struct mwifiex_802_11_ssid *del_ssid)
{
        s32 table_idx = -1;

        dev_dbg(priv->adapter->dev, "info: scan: delete ssid entry: %-32s\n",
                        del_ssid->ssid);

        /* If the requested SSID is found in the table, delete it.  Then keep
           searching the table for multiple entires for the SSID until no
           more are found */
        while ((table_idx = mwifiex_find_ssid_in_list(priv, del_ssid, NULL,
                                        NL80211_IFTYPE_UNSPECIFIED)) >= 0) {
                dev_dbg(priv->adapter->dev,
                        "info: Scan: Delete SSID Entry: Found Idx = %d\n",
                       table_idx);
                mwifiex_scan_delete_table_entry(priv, table_idx);
        }

        return table_idx == -1 ? -1 : 0;
}

/*
 * This is an internal function used to start a scan based on an input
 * configuration.
 *
 * This uses 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.
 */
int mwifiex_scan_networks(struct mwifiex_private *priv,
                          const struct mwifiex_user_scan_cfg *user_scan_in)
{
        int ret = 0;
        struct mwifiex_adapter *adapter = priv->adapter;
        struct cmd_ctrl_node *cmd_node;
        union mwifiex_scan_cmd_config_tlv *scan_cfg_out;
        struct mwifiex_ie_types_chan_list_param_set *chan_list_out;
        u32 buf_size;
        struct mwifiex_chan_scan_param_set *scan_chan_list;
        u8 keep_previous_scan;
        u8 filtered_scan;
        u8 scan_current_chan_only;
        u8 max_chan_per_scan;
        unsigned long flags;

        if (adapter->scan_processing) {
                dev_dbg(adapter->dev, "cmd: Scan already in process...\n");
                return ret;
        }

        spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
        adapter->scan_processing = true;
        spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);

        if (priv->scan_block) {
                dev_dbg(adapter->dev,
                        "cmd: Scan is blocked during association...\n");
                return ret;
        }

        scan_cfg_out = kzalloc(sizeof(union mwifiex_scan_cmd_config_tlv),
                                        GFP_KERNEL);
        if (!scan_cfg_out) {
                dev_err(adapter->dev, "failed to alloc scan_cfg_out\n");
                return -ENOMEM;
        }

        buf_size = sizeof(struct mwifiex_chan_scan_param_set) *
                        MWIFIEX_USER_SCAN_CHAN_MAX;
        scan_chan_list = kzalloc(buf_size, GFP_KERNEL);
        if (!scan_chan_list) {
                dev_err(adapter->dev, "failed to alloc scan_chan_list\n");
                kfree(scan_cfg_out);
                return -ENOMEM;
        }

        keep_previous_scan = false;

        mwifiex_scan_setup_scan_config(priv, user_scan_in,
                                       &scan_cfg_out->config, &chan_list_out,
                                       scan_chan_list, &max_chan_per_scan,
                                       &filtered_scan, &scan_current_chan_only);

        if (user_scan_in)
                keep_previous_scan = user_scan_in->keep_previous_scan;


        if (!keep_previous_scan) {
                memset(adapter->scan_table, 0x00,
                       sizeof(struct mwifiex_bssdescriptor) * IW_MAX_AP);
                adapter->num_in_scan_table = 0;
                adapter->bcn_buf_end = adapter->bcn_buf;
        }

        ret = mwifiex_scan_channel_list(priv, max_chan_per_scan, filtered_scan,
                                        &scan_cfg_out->config, chan_list_out,
                                        scan_chan_list);

        /* Get scan command from scan_pending_q and put to cmd_pending_q */
        if (!ret) {
                spin_lock_irqsave(&adapter->scan_pending_q_lock, flags);
                if (!list_empty(&adapter->scan_pending_q)) {
                        cmd_node = list_first_entry(&adapter->scan_pending_q,
                                                struct cmd_ctrl_node, list);
                        list_del(&cmd_node->list);
                        spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
                                                                        flags);
                        mwifiex_insert_cmd_to_pending_q(adapter, cmd_node,
                                                        true);
                } else {
                        spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
                                               flags);
                }
        } else {
                spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
                adapter->scan_processing = true;
                spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
        }

        kfree(scan_cfg_out);
        kfree(scan_chan_list);
        return ret;
}

/*
 * This function prepares a scan command to be sent to the firmware.
 *
 * This uses the scan command configuration sent to the command processing
 * module in command preparation stage to configure a scan command structure
 * 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.
 *
 * Preparation also includes -
 *      - Setting command ID, and proper size
 *      - Ensuring correct endian-ness
 */
int mwifiex_cmd_802_11_scan(struct host_cmd_ds_command *cmd,
                            struct mwifiex_scan_cmd_config *scan_cfg)
{
        struct host_cmd_ds_802_11_scan *scan_cmd = &cmd->params.scan;

        /* Set fixed field variables in scan command */
        scan_cmd->bss_mode = scan_cfg->bss_mode;
        memcpy(scan_cmd->bssid, scan_cfg->specific_bssid,
               sizeof(scan_cmd->bssid));
        memcpy(scan_cmd->tlv_buffer, scan_cfg->tlv_buf, scan_cfg->tlv_buf_len);

        cmd->command = cpu_to_le16(HostCmd_CMD_802_11_SCAN);

        /* Size is equal to the sizeof(fixed portions) + the TLV len + header */
        cmd->size = cpu_to_le16((u16) (sizeof(scan_cmd->bss_mode)
                                          + sizeof(scan_cmd->bssid)
                                          + scan_cfg->tlv_buf_len + S_DS_GEN));

        return 0;
}

/*
 * This function handles the command response of scan.
 *
 * The response buffer for the scan command has the following
 * memory layout:
 *
 *      .-------------------------------------------------------------.
 *      |  Header (4 * sizeof(t_u16)):  Standard command response hdr |
 *      .-------------------------------------------------------------.
 *      |  BufSize (t_u16) : sizeof the BSS Description data          |
 *      .-------------------------------------------------------------.
 *      |  NumOfSet (t_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)       |
 *      .-------------------------------------------------------------.
 */
int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                            struct host_cmd_ds_command *resp)
{
        int ret = 0;
        struct mwifiex_adapter *adapter = priv->adapter;
        struct cmd_ctrl_node *cmd_node;
        struct host_cmd_ds_802_11_scan_rsp *scan_rsp;
        struct mwifiex_bssdescriptor *bss_new_entry = NULL;
        struct mwifiex_ie_types_data *tlv_data;
        struct mwifiex_ie_types_tsf_timestamp *tsf_tlv;
        u8 *bss_info;
        u32 scan_resp_size;
        u32 bytes_left;
        u32 num_in_table;
        u32 bss_idx;
        u32 idx;
        u32 tlv_buf_size;
        long long tsf_val;
        struct mwifiex_chan_freq_power *cfp;
        struct mwifiex_ie_types_chan_band_list_param_set *chan_band_tlv;
        struct chan_band_param_set *chan_band;
        u8 band;
        u8 is_bgscan_resp;
        unsigned long flags;

        is_bgscan_resp = (le16_to_cpu(resp->command)
                == HostCmd_CMD_802_11_BG_SCAN_QUERY);
        if (is_bgscan_resp)
                scan_rsp = &resp->params.bg_scan_query_resp.scan_resp;
        else
                scan_rsp = &resp->params.scan_resp;


        if (scan_rsp->number_of_sets > IW_MAX_AP) {
                dev_err(adapter->dev, "SCAN_RESP: too many AP returned (%d)\n",
                       scan_rsp->number_of_sets);
                ret = -1;
                goto done;
        }

        bytes_left = le16_to_cpu(scan_rsp->bss_descript_size);
        dev_dbg(adapter->dev, "info: SCAN_RESP: bss_descript_size %d\n",
                                                bytes_left);

        scan_resp_size = le16_to_cpu(resp->size);

        dev_dbg(adapter->dev,
                "info: SCAN_RESP: returned %d APs before parsing\n",
               scan_rsp->number_of_sets);

        num_in_table = adapter->num_in_scan_table;
        bss_info = scan_rsp->bss_desc_and_tlv_buffer;

        /*
         * The size of the TLV buffer is equal to the entire command response
         *   size (scan_resp_size) minus the fixed fields (sizeof()'s), the
         *   BSS Descriptions (bss_descript_size as bytesLef) and the command
         *   response header (S_DS_GEN)
         */
        tlv_buf_size = scan_resp_size - (bytes_left
                                         + sizeof(scan_rsp->bss_descript_size)
                                         + sizeof(scan_rsp->number_of_sets)
                                         + S_DS_GEN);

        tlv_data = (struct mwifiex_ie_types_data *) (scan_rsp->
                                                 bss_desc_and_tlv_buffer +
                                                 bytes_left);

        /* Search the TLV buffer space in the scan response for any valid
           TLVs */
        mwifiex_ret_802_11_scan_get_tlv_ptrs(adapter, tlv_data, tlv_buf_size,
                                             TLV_TYPE_TSFTIMESTAMP,
                                             (struct mwifiex_ie_types_data **)
                                             &tsf_tlv);

        /* Search the TLV buffer space in the scan response for any valid
           TLVs */
        mwifiex_ret_802_11_scan_get_tlv_ptrs(adapter, tlv_data, tlv_buf_size,
                                             TLV_TYPE_CHANNELBANDLIST,
                                             (struct mwifiex_ie_types_data **)
                                             &chan_band_tlv);

        /*
         *  Process each scan response returned (scan_rsp->number_of_sets).
         *  Save the information in the bss_new_entry 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
         */
        bss_new_entry = kzalloc(sizeof(struct mwifiex_bssdescriptor),
                                GFP_KERNEL);
        if (!bss_new_entry) {
                dev_err(adapter->dev, " failed to alloc bss_new_entry\n");
                return -ENOMEM;
        }

        for (idx = 0; idx < scan_rsp->number_of_sets && bytes_left; idx++) {
                /* Zero out the bss_new_entry we are about to store info in */
                memset(bss_new_entry, 0x00,
                       sizeof(struct mwifiex_bssdescriptor));

                if (mwifiex_interpret_bss_desc_with_ie(adapter, bss_new_entry,
                                                        &bss_info,
                                                        &bytes_left)) {
                        /* Error parsing/interpreting scan response, skipped */
                        dev_err(adapter->dev, "SCAN_RESP: "
                               "mwifiex_interpret_bss_desc_with_ie "
                               "returned ERROR\n");
                        continue;
                }

                /* Process the data fields and IEs returned for this BSS */
                dev_dbg(adapter->dev, "info: SCAN_RESP: BSSID = %pM\n",
                       bss_new_entry->mac_address);

                /* Search the scan table for the same bssid */
                for (bss_idx = 0; bss_idx < num_in_table; bss_idx++) {
                        if (memcmp(bss_new_entry->mac_address,
                                adapter->scan_table[bss_idx].mac_address,
                                sizeof(bss_new_entry->mac_address))) {
                                continue;
                        }
                        /*
                         * If the SSID matches as well, it is a
                         * duplicate of this entry.  Keep the bss_idx
                         * set to this entry so we replace the old
                         * contents in the table
                         */
                        if ((bss_new_entry->ssid.ssid_len
                                == adapter->scan_table[bss_idx]. ssid.ssid_len)
                                        && (!memcmp(bss_new_entry->ssid.ssid,
                                        adapter->scan_table[bss_idx].ssid.ssid,
                                        bss_new_entry->ssid.ssid_len))) {
                                dev_dbg(adapter->dev, "info: SCAN_RESP:"
                                        " duplicate of index: %d\n", bss_idx);
                                break;
                        }
                }
                /*
                 * If the bss_idx is equal to the number of entries in
                 * the table, the new entry was not a duplicate; append
                 * it to the scan table
                 */
                if (bss_idx == num_in_table) {
                        /* Range check the bss_idx, keep it limited to
                           the last entry */
                        if (bss_idx == IW_MAX_AP)
                                bss_idx--;
                        else
                                num_in_table++;
                }

                /*
                 * Save the beacon/probe response returned for later application
                 * retrieval.  Duplicate beacon/probe responses are updated if
                 * possible
                 */
                mwifiex_ret_802_11_scan_store_beacon(priv, bss_idx,
                                                num_in_table, bss_new_entry);
                /*
                 * If the TSF TLV was appended to the scan results, save this
                 * entry's 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 (tsf_tlv) {
                        memcpy(&tsf_val, &tsf_tlv->tsf_data[idx * TSF_DATA_SIZE]
                                        , sizeof(tsf_val));
                        memcpy(&bss_new_entry->network_tsf, &tsf_val,
                                        sizeof(bss_new_entry->network_tsf));
                }
                band = BAND_G;
                if (chan_band_tlv) {
                        chan_band = &chan_band_tlv->chan_band_param[idx];
                        band = mwifiex_radio_type_to_band(chan_band->radio_type
                                        & (BIT(0) | BIT(1)));
                }

                /* Save the band designation for this entry for use in join */
                bss_new_entry->bss_band = band;
                cfp = mwifiex_get_cfp_by_band_and_channel_from_cfg80211(priv,
                                        (u8) bss_new_entry->bss_band,
                                        (u16)bss_new_entry->channel);

                if (cfp)
                        bss_new_entry->freq = cfp->freq;
                else
                        bss_new_entry->freq = 0;

                /* Copy the locally created bss_new_entry to the scan table */
                memcpy(&adapter->scan_table[bss_idx], bss_new_entry,
                       sizeof(adapter->scan_table[bss_idx]));

        }

        dev_dbg(adapter->dev,
                "info: SCAN_RESP: Scanned %2d APs, %d valid, %d total\n",
               scan_rsp->number_of_sets,
               num_in_table - adapter->num_in_scan_table, num_in_table);

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

        spin_lock_irqsave(&adapter->scan_pending_q_lock, flags);
        if (list_empty(&adapter->scan_pending_q)) {
                spin_unlock_irqrestore(&adapter->scan_pending_q_lock, flags);
                spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
                adapter->scan_processing = false;
                spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
                /*
                 * Process the resulting scan table:
                 *   - Remove any bad ssids
                 *   - Update our current BSS information from scan data
                 */
                mwifiex_process_scan_results(priv);

                /* Need to indicate IOCTL complete */
                if (adapter->curr_cmd->wait_q_enabled) {
                        adapter->cmd_wait_q.status = 0;
                        mwifiex_complete_cmd(adapter);
                }
                if (priv->report_scan_result)
                        priv->report_scan_result = false;
                if (priv->scan_pending_on_block) {
                        priv->scan_pending_on_block = false;
                        up(&priv->async_sem);
                }

        } else {
                /* Get scan command from scan_pending_q and put to
                   cmd_pending_q */
                cmd_node = list_first_entry(&adapter->scan_pending_q,
                                            struct cmd_ctrl_node, list);
                list_del(&cmd_node->list);
                spin_unlock_irqrestore(&adapter->scan_pending_q_lock, flags);

                mwifiex_insert_cmd_to_pending_q(adapter, cmd_node, true);
        }

done:
        kfree((u8 *) bss_new_entry);
        return ret;
}

/*
 * This function prepares command for background scan query.
 *
 * Preparation includes -
 *      - Setting command ID and proper size
 *      - Setting background scan flush parameter
 *      - Ensuring correct endian-ness
 */
int mwifiex_cmd_802_11_bg_scan_query(struct host_cmd_ds_command *cmd)
{
        struct host_cmd_ds_802_11_bg_scan_query *bg_query =
                &cmd->params.bg_scan_query;

        cmd->command = cpu_to_le16(HostCmd_CMD_802_11_BG_SCAN_QUERY);
        cmd->size = cpu_to_le16(sizeof(struct host_cmd_ds_802_11_bg_scan_query)
                                + S_DS_GEN);

        bg_query->flush = 1;

        return 0;
}

/*
 * This function finds a SSID in the scan table.
 *
 * A BSSID may optionally be provided to qualify the SSID.
 * For non-Auto mode, further check is made to make sure the
 * BSS found in the scan table is compatible with the current
 * settings of the driver.
 */
s32
mwifiex_find_ssid_in_list(struct mwifiex_private *priv,
                          struct mwifiex_802_11_ssid *ssid, u8 *bssid,
                          u32 mode)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        s32 net = -1, j;
        u8 best_rssi = 0;
        u32 i;

        dev_dbg(adapter->dev, "info: num of entries in table = %d\n",
               adapter->num_in_scan_table);

        /*
         * Loop through the table until the maximum is reached or until a match
         *   is found based on the bssid field comparison
         */
        for (i = 0;
             i < adapter->num_in_scan_table && (!bssid || (bssid && net < 0));
             i++) {
                if (!mwifiex_ssid_cmp(&adapter->scan_table[i].ssid, ssid) &&
                    (!bssid
                     || !memcmp(adapter->scan_table[i].mac_address, bssid,
                                ETH_ALEN))
                    &&
                    (mwifiex_get_cfp_by_band_and_channel_from_cfg80211
                     (priv, (u8) adapter->scan_table[i].bss_band,
                      (u16) adapter->scan_table[i].channel))) {
                        switch (mode) {
                        case NL80211_IFTYPE_STATION:
                        case NL80211_IFTYPE_ADHOC:
                                j = mwifiex_is_network_compatible(priv, i,
                                                                  mode);

                                if (j >= 0) {
                                        if (SCAN_RSSI
                                            (adapter->scan_table[i].rssi) >
                                            best_rssi) {
                                                best_rssi = SCAN_RSSI(adapter->
                                                                  scan_table
                                                                  [i].rssi);
                                                net = i;
                                        }
                                } else {
                                        if (net == -1)
                                                net = j;
                                }
                                break;
                        case NL80211_IFTYPE_UNSPECIFIED:
                        default:
                                /*
                                 * Do not check compatibility if the mode
                                 * requested is Auto/Unknown.  Allows generic
                                 * find to work without verifying against the
                                 * Adapter security settings
                                 */
                                if (SCAN_RSSI(adapter->scan_table[i].rssi) >
                                    best_rssi) {
                                        best_rssi = SCAN_RSSI(adapter->
                                                          scan_table[i].rssi);
                                        net = i;
                                }
                                break;
                        }
                }
        }

        return net;
}

/*
 * This function finds a specific compatible BSSID in the scan list.
 *
 * This function loops through the scan table looking for a compatible
 * match. If a BSSID matches, but the BSS is found to be not compatible
 * the function ignores it and continues to search through the rest of
 * the entries in case there is an AP with multiple SSIDs assigned to
 * the same BSSID.
 */
s32
mwifiex_find_bssid_in_list(struct mwifiex_private *priv, u8 *bssid,
                           u32 mode)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        s32 net = -1;
        u32 i;

        if (!bssid)
                return -1;

        dev_dbg(adapter->dev, "info: FindBSSID: Num of BSSIDs = %d\n",
               adapter->num_in_scan_table);

        /*
         * 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; net < 0 && i < adapter->num_in_scan_table; i++) {
                if (!memcmp
                    (adapter->scan_table[i].mac_address, bssid, ETH_ALEN)
                        && mwifiex_get_cfp_by_band_and_channel_from_cfg80211
                                                                (priv,
                                                            (u8) adapter->
                                                            scan_table[i].
                                                            bss_band,
                                                            (u16) adapter->
                                                            scan_table[i].
                                                            channel)) {
                        switch (mode) {
                        case NL80211_IFTYPE_STATION:
                        case NL80211_IFTYPE_ADHOC:
                                net = mwifiex_is_network_compatible(priv, i,
                                                                    mode);
                                break;
                        default:
                                net = i;
                                break;
                        }
                }
        }

        return net;
}

/*
 * This function inserts scan command node to the scan pending queue.
 */
void
mwifiex_queue_scan_cmd(struct mwifiex_private *priv,
                       struct cmd_ctrl_node *cmd_node)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        unsigned long flags;

        cmd_node->wait_q_enabled = true;
        spin_lock_irqsave(&adapter->scan_pending_q_lock, flags);
        list_add_tail(&cmd_node->list, &adapter->scan_pending_q);
        spin_unlock_irqrestore(&adapter->scan_pending_q_lock, flags);
}

/*
 * This function finds an AP with specific ssid in the scan list.
 */
int mwifiex_find_best_network(struct mwifiex_private *priv,
                              struct mwifiex_ssid_bssid *req_ssid_bssid)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_bssdescriptor *req_bss;
        s32 i;

        memset(req_ssid_bssid, 0, sizeof(struct mwifiex_ssid_bssid));

        i = mwifiex_find_best_network_in_list(priv);

        if (i >= 0) {
                req_bss = &adapter->scan_table[i];
                memcpy(&req_ssid_bssid->ssid, &req_bss->ssid,
                       sizeof(struct mwifiex_802_11_ssid));
                memcpy((u8 *) &req_ssid_bssid->bssid,
                       (u8 *) &req_bss->mac_address, ETH_ALEN);

                /* Make sure we are in the right mode */
                if (priv->bss_mode == NL80211_IFTYPE_UNSPECIFIED)
                        priv->bss_mode = req_bss->bss_mode;
        }

        if (!req_ssid_bssid->ssid.ssid_len)
                return -1;

        dev_dbg(adapter->dev, "info: Best network found = [%s], "
               "[%pM]\n", req_ssid_bssid->ssid.ssid,
               req_ssid_bssid->bssid);

        return 0;
}

/*
 * This function sends a scan command for all available channels to the
 * firmware, filtered on a specific SSID.
 */
static int mwifiex_scan_specific_ssid(struct mwifiex_private *priv,
                                      struct mwifiex_802_11_ssid *req_ssid)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        int ret = 0;
        struct mwifiex_user_scan_cfg *scan_cfg;

        if (!req_ssid)
                return -1;

        if (adapter->scan_processing) {
                dev_dbg(adapter->dev, "cmd: Scan already in process...\n");
                return ret;
        }

        if (priv->scan_block) {
                dev_dbg(adapter->dev,
                        "cmd: Scan is blocked during association...\n");
                return ret;
        }

        mwifiex_scan_delete_ssid_table_entry(priv, req_ssid);

        scan_cfg = kzalloc(sizeof(struct mwifiex_user_scan_cfg), GFP_KERNEL);
        if (!scan_cfg) {
                dev_err(adapter->dev, "failed to alloc scan_cfg\n");
                return -ENOMEM;
        }

        memcpy(scan_cfg->ssid_list[0].ssid, req_ssid->ssid,
               req_ssid->ssid_len);
        scan_cfg->keep_previous_scan = true;

        ret = mwifiex_scan_networks(priv, scan_cfg);

        kfree(scan_cfg);
        return ret;
}

/*
 * Sends IOCTL request to start a scan.
 *
 * This function allocates the IOCTL request buffer, fills it
 * with requisite parameters and calls the IOCTL handler.
 *
 * Scan command can be issued for both normal scan and specific SSID
 * scan, depending upon whether an SSID is provided or not.
 */
int mwifiex_request_scan(struct mwifiex_private *priv,
                         struct mwifiex_802_11_ssid *req_ssid)
{
        int ret;

        if (down_interruptible(&priv->async_sem)) {
                dev_err(priv->adapter->dev, "%s: acquire semaphore\n",
                                                __func__);
                return -1;
        }
        priv->scan_pending_on_block = true;

        priv->adapter->cmd_wait_q.condition = false;

        if (req_ssid && req_ssid->ssid_len != 0)
                /* Specific SSID scan */
                ret = mwifiex_scan_specific_ssid(priv, req_ssid);
        else
                /* Normal scan */
                ret = mwifiex_scan_networks(priv, NULL);

        if (!ret)
                ret = mwifiex_wait_queue_complete(priv->adapter);

        if (ret == -1) {
                priv->scan_pending_on_block = false;
                up(&priv->async_sem);
        }

        return ret;
}

/*
 * This function appends the vendor specific IE TLV to a buffer.
 */
int
mwifiex_cmd_append_vsie_tlv(struct mwifiex_private *priv,
                            u16 vsie_mask, u8 **buffer)
{
        int id, ret_len = 0;
        struct mwifiex_ie_types_vendor_param_set *vs_param_set;

        if (!buffer)
                return 0;
        if (!(*buffer))
                return 0;

        /*
         * Traverse through the saved vendor specific IE array and append
         * the selected(scan/assoc/adhoc) IE as TLV to the command
         */
        for (id = 0; id < MWIFIEX_MAX_VSIE_NUM; id++) {
                if (priv->vs_ie[id].mask & vsie_mask) {
                        vs_param_set =
                                (struct mwifiex_ie_types_vendor_param_set *)
                                *buffer;
                        vs_param_set->header.type =
                                cpu_to_le16(TLV_TYPE_PASSTHROUGH);
                        vs_param_set->header.len =
                                cpu_to_le16((((u16) priv->vs_ie[id].ie[1])
                                & 0x00FF) + 2);
                        memcpy(vs_param_set->ie, priv->vs_ie[id].ie,
                               le16_to_cpu(vs_param_set->header.len));
                        *buffer += le16_to_cpu(vs_param_set->header.len) +
                                   sizeof(struct mwifiex_ie_types_header);
                        ret_len += le16_to_cpu(vs_param_set->header.len) +
                                   sizeof(struct mwifiex_ie_types_header);
                }
        }
        return ret_len;
}

/*
 * This function saves a beacon buffer of the current BSS descriptor.
 *
 * The current beacon buffer is saved so that it can be restored in the
 * following cases that makes the beacon buffer not to contain the current
 * ssid's beacon buffer.
 *      - The current ssid was not found somehow in the last scan.
 *      - The current ssid was the last entry of the scan table and overloaded.
 */
void
mwifiex_save_curr_bcn(struct mwifiex_private *priv)
{
        struct mwifiex_bssdescriptor *curr_bss =
                &priv->curr_bss_params.bss_descriptor;

        if (!curr_bss->beacon_buf_size)
                return;

        /* allocate beacon buffer at 1st time; or if it's size has changed */
        if (!priv->curr_bcn_buf ||
                        priv->curr_bcn_size != curr_bss->beacon_buf_size) {
                priv->curr_bcn_size = curr_bss->beacon_buf_size;

                kfree(priv->curr_bcn_buf);
                priv->curr_bcn_buf = kzalloc(curr_bss->beacon_buf_size,
                                                GFP_KERNEL);
                if (!priv->curr_bcn_buf) {
                        dev_err(priv->adapter->dev,
                                        "failed to alloc curr_bcn_buf\n");
                        return;
                }
        }

        memcpy(priv->curr_bcn_buf, curr_bss->beacon_buf,
                curr_bss->beacon_buf_size);
        dev_dbg(priv->adapter->dev, "info: current beacon saved %d\n",
                priv->curr_bcn_size);
}

/*
 * This function frees the current BSS descriptor beacon buffer.
 */
void
mwifiex_free_curr_bcn(struct mwifiex_private *priv)
{
        kfree(priv->curr_bcn_buf);
        priv->curr_bcn_buf = NULL;
}