mlme.c

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/*
 * BSS client mode implementation
 * Copyright 2003-2008, Jouni Malinen <[email protected]>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <[email protected]>
 * Copyright 2007, Michael Wu <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/moduleparam.h>
#include <linux/rtnetlink.h>
#include <linux/pm_qos.h>
#include <linux/crc32.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "led.h"

#define IEEE80211_AUTH_TIMEOUT (HZ / 5)
#define IEEE80211_AUTH_MAX_TRIES 3
#define IEEE80211_AUTH_WAIT_ASSOC (HZ * 5)
#define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
#define IEEE80211_ASSOC_MAX_TRIES 3

static int max_nullfunc_tries = 2;
module_param(max_nullfunc_tries, int, 0644);
MODULE_PARM_DESC(max_nullfunc_tries,
         "Maximum nullfunc tx tries before disconnecting (reason 4).");

static int max_probe_tries = 5;
module_param(max_probe_tries, int, 0644);
MODULE_PARM_DESC(max_probe_tries,
         "Maximum probe tries before disconnecting (reason 4).");

/*
 * Beacon loss timeout is calculated as N frames times the
 * advertised beacon interval.  This may need to be somewhat
 * higher than what hardware might detect to account for
 * delays in the host processing frames. But since we also
 * probe on beacon miss before declaring the connection lost
 * default to what we want.
 */
#define IEEE80211_BEACON_LOSS_COUNT 7

/*
 * Time the connection can be idle before we probe
 * it to see if we can still talk to the AP.
 */
#define IEEE80211_CONNECTION_IDLE_TIME  (30 * HZ)
/*
 * Time we wait for a probe response after sending
 * a probe request because of beacon loss or for
 * checking the connection still works.
 */
static int probe_wait_ms = 500;
module_param(probe_wait_ms, int, 0644);
MODULE_PARM_DESC(probe_wait_ms,
         "Maximum time(ms) to wait for probe response"
         " before disconnecting (reason 4).");

/*
 * Weight given to the latest Beacon frame when calculating average signal
 * strength for Beacon frames received in the current BSS. This must be
 * between 1 and 15.
 */
#define IEEE80211_SIGNAL_AVE_WEIGHT 3

/*
 * How many Beacon frames need to have been used in average signal strength
 * before starting to indicate signal change events.
 */
#define IEEE80211_SIGNAL_AVE_MIN_COUNT  4

#define TMR_RUNNING_TIMER   0
#define TMR_RUNNING_CHANSW  1

/*
 * All cfg80211 functions have to be called outside a locked
 * section so that they can acquire a lock themselves... This
 * is much simpler than queuing up things in cfg80211, but we
 * do need some indirection for that here.
 */
enum rx_mgmt_action {
    /* no action required */
    RX_MGMT_NONE,

    /* caller must call cfg80211_send_deauth() */
    RX_MGMT_CFG80211_DEAUTH,

    /* caller must call cfg80211_send_disassoc() */
    RX_MGMT_CFG80211_DISASSOC,

    /* caller must call cfg80211_send_rx_auth() */
    RX_MGMT_CFG80211_RX_AUTH,

    /* caller must call cfg80211_send_rx_assoc() */
    RX_MGMT_CFG80211_RX_ASSOC,

    /* caller must call cfg80211_send_assoc_timeout() */
    RX_MGMT_CFG80211_ASSOC_TIMEOUT,
};

/* utils */
static inline void ASSERT_MGD_MTX(struct ieee80211_if_managed *ifmgd)
{
    lockdep_assert_held(&ifmgd->mtx);
}

/*
 * We can have multiple work items (and connection probing)
 * scheduling this timer, but we need to take care to only
 * reschedule it when it should fire _earlier_ than it was
 * asked for before, or if it's not pending right now. This
 * function ensures that. Note that it then is required to
 * run this function for all timeouts after the first one
 * has happened -- the work that runs from this timer will
 * do that.
 */
static void run_again(struct ieee80211_if_managed *ifmgd, unsigned long timeout)
{
    ASSERT_MGD_MTX(ifmgd);

    if (!timer_pending(&ifmgd->timer) ||
        time_before(timeout, ifmgd->timer.expires))
        mod_timer(&ifmgd->timer, timeout);
}

void ieee80211_sta_reset_beacon_monitor(struct ieee80211_sub_if_data *sdata)
{
    if (sdata->vif.driver_flags & IEEE80211_VIF_BEACON_FILTER)
        return;

    if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
        return;

    mod_timer(&sdata->u.mgd.bcn_mon_timer,
          round_jiffies_up(jiffies + sdata->u.mgd.beacon_timeout));
}

void ieee80211_sta_reset_conn_monitor(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    if (unlikely(!sdata->u.mgd.associated))
        return;

    if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
        return;

    mod_timer(&sdata->u.mgd.conn_mon_timer,
          round_jiffies_up(jiffies + IEEE80211_CONNECTION_IDLE_TIME));

    ifmgd->probe_send_count = 0;
}

static int ecw2cw(int ecw)
{
    return (1 << ecw) - 1;
}

static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
                  struct ieee80211_ht_operation *ht_oper,
                  const u8 *bssid, bool reconfig)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_supported_band *sband;
    struct sta_info *sta;
    u32 changed = 0;
    u16 ht_opmode;
    bool disable_40 = false;

    sband = local->hw.wiphy->bands[local->oper_channel->band];

    switch (sdata->vif.bss_conf.channel_type) {
    case NL80211_CHAN_HT40PLUS:
        if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40PLUS)
            disable_40 = true;
        break;
    case NL80211_CHAN_HT40MINUS:
        if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40MINUS)
            disable_40 = true;
        break;
    default:
        break;
    }

    /* This can change during the lifetime of the BSS */
    if (!(ht_oper->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
        disable_40 = true;

    mutex_lock(&local->sta_mtx);
    sta = sta_info_get(sdata, bssid);

    WARN_ON_ONCE(!sta);

    if (sta && !sta->supports_40mhz)
        disable_40 = true;

    if (sta && (!reconfig ||
            (disable_40 != !(sta->sta.ht_cap.cap &
                    IEEE80211_HT_CAP_SUP_WIDTH_20_40)))) {

        if (disable_40)
            sta->sta.ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
        else
            sta->sta.ht_cap.cap |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;

        rate_control_rate_update(local, sband, sta,
                     IEEE80211_RC_BW_CHANGED);
    }
    mutex_unlock(&local->sta_mtx);

    ht_opmode = le16_to_cpu(ht_oper->operation_mode);

    /* if bss configuration changed store the new one */
    if (!reconfig || (sdata->vif.bss_conf.ht_operation_mode != ht_opmode)) {
        changed |= BSS_CHANGED_HT;
        sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
    }

    return changed;
}

/* frame sending functions */

static int ieee80211_compatible_rates(const u8 *supp_rates, int supp_rates_len,
                      struct ieee80211_supported_band *sband,
                      u32 *rates)
{
    int i, j, count;
    *rates = 0;
    count = 0;
    for (i = 0; i < supp_rates_len; i++) {
        int rate = (supp_rates[i] & 0x7F) * 5;

        for (j = 0; j < sband->n_bitrates; j++)
            if (sband->bitrates[j].bitrate == rate) {
                *rates |= BIT(j);
                count++;
                break;
            }
    }

    return count;
}

static void ieee80211_add_ht_ie(struct ieee80211_sub_if_data *sdata,
                struct sk_buff *skb, u8 ap_ht_param,
                struct ieee80211_supported_band *sband,
                struct ieee80211_channel *channel,
                enum ieee80211_smps_mode smps)
{
    u8 *pos;
    u32 flags = channel->flags;
    u16 cap;
    struct ieee80211_sta_ht_cap ht_cap;

    BUILD_BUG_ON(sizeof(ht_cap) != sizeof(sband->ht_cap));

    memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
    ieee80211_apply_htcap_overrides(sdata, &ht_cap);

    /* determine capability flags */
    cap = ht_cap.cap;

    switch (ap_ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
    case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
        if (flags & IEEE80211_CHAN_NO_HT40PLUS) {
            cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
            cap &= ~IEEE80211_HT_CAP_SGI_40;
        }
        break;
    case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
        if (flags & IEEE80211_CHAN_NO_HT40MINUS) {
            cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
            cap &= ~IEEE80211_HT_CAP_SGI_40;
        }
        break;
    }

    /*
     * If 40 MHz was disabled associate as though we weren't
     * capable of 40 MHz -- some broken APs will never fall
     * back to trying to transmit in 20 MHz.
     */
    if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_40MHZ) {
        cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
        cap &= ~IEEE80211_HT_CAP_SGI_40;
    }

    /* set SM PS mode properly */
    cap &= ~IEEE80211_HT_CAP_SM_PS;
    switch (smps) {
    case IEEE80211_SMPS_AUTOMATIC:
    case IEEE80211_SMPS_NUM_MODES:
        WARN_ON(1);
    case IEEE80211_SMPS_OFF:
        cap |= WLAN_HT_CAP_SM_PS_DISABLED <<
            IEEE80211_HT_CAP_SM_PS_SHIFT;
        break;
    case IEEE80211_SMPS_STATIC:
        cap |= WLAN_HT_CAP_SM_PS_STATIC <<
            IEEE80211_HT_CAP_SM_PS_SHIFT;
        break;
    case IEEE80211_SMPS_DYNAMIC:
        cap |= WLAN_HT_CAP_SM_PS_DYNAMIC <<
            IEEE80211_HT_CAP_SM_PS_SHIFT;
        break;
    }

    /* reserve and fill IE */
    pos = skb_put(skb, sizeof(struct ieee80211_ht_cap) + 2);
    ieee80211_ie_build_ht_cap(pos, &ht_cap, cap);
}

static void ieee80211_add_vht_ie(struct ieee80211_sub_if_data *sdata,
                 struct sk_buff *skb,
                 struct ieee80211_supported_band *sband)
{
    u8 *pos;
    u32 cap;
    struct ieee80211_sta_vht_cap vht_cap;

    BUILD_BUG_ON(sizeof(vht_cap) != sizeof(sband->vht_cap));

    memcpy(&vht_cap, &sband->vht_cap, sizeof(vht_cap));

    /* determine capability flags */
    cap = vht_cap.cap;

    /* reserve and fill IE */
    pos = skb_put(skb, sizeof(struct ieee80211_vht_capabilities) + 2);
    ieee80211_ie_build_vht_cap(pos, &vht_cap, cap);
}

static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_mgd_assoc_data *assoc_data = ifmgd->assoc_data;
    struct sk_buff *skb;
    struct ieee80211_mgmt *mgmt;
    u8 *pos, qos_info;
    size_t offset = 0, noffset;
    int i, count, rates_len, supp_rates_len;
    u16 capab;
    struct ieee80211_supported_band *sband;
    u32 rates = 0;

    lockdep_assert_held(&ifmgd->mtx);

    sband = local->hw.wiphy->bands[local->oper_channel->band];

    if (assoc_data->supp_rates_len) {
        /*
         * Get all rates supported by the device and the AP as
         * some APs don't like getting a superset of their rates
         * in the association request (e.g. D-Link DAP 1353 in
         * b-only mode)...
         */
        rates_len = ieee80211_compatible_rates(assoc_data->supp_rates,
                               assoc_data->supp_rates_len,
                               sband, &rates);
    } else {
        /*
         * In case AP not provide any supported rates information
         * before association, we send information element(s) with
         * all rates that we support.
         */
        rates = ~0;
        rates_len = sband->n_bitrates;
    }

    skb = alloc_skb(local->hw.extra_tx_headroom +
            sizeof(*mgmt) + /* bit too much but doesn't matter */
            2 + assoc_data->ssid_len + /* SSID */
            4 + rates_len + /* (extended) rates */
            4 + /* power capability */
            2 + 2 * sband->n_channels + /* supported channels */
            2 + sizeof(struct ieee80211_ht_cap) + /* HT */
            2 + sizeof(struct ieee80211_vht_capabilities) + /* VHT */
            assoc_data->ie_len + /* extra IEs */
            9, /* WMM */
            GFP_KERNEL);
    if (!skb)
        return;

    skb_reserve(skb, local->hw.extra_tx_headroom);

    capab = WLAN_CAPABILITY_ESS;

    if (sband->band == IEEE80211_BAND_2GHZ) {
        if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
            capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
        if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
            capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
    }

    if (assoc_data->capability & WLAN_CAPABILITY_PRIVACY)
        capab |= WLAN_CAPABILITY_PRIVACY;

    if ((assoc_data->capability & WLAN_CAPABILITY_SPECTRUM_MGMT) &&
        (local->hw.flags & IEEE80211_HW_SPECTRUM_MGMT))
        capab |= WLAN_CAPABILITY_SPECTRUM_MGMT;

    mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
    memset(mgmt, 0, 24);
    memcpy(mgmt->da, assoc_data->bss->bssid, ETH_ALEN);
    memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
    memcpy(mgmt->bssid, assoc_data->bss->bssid, ETH_ALEN);

    if (!is_zero_ether_addr(assoc_data->prev_bssid)) {
        skb_put(skb, 10);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                          IEEE80211_STYPE_REASSOC_REQ);
        mgmt->u.reassoc_req.capab_info = cpu_to_le16(capab);
        mgmt->u.reassoc_req.listen_interval =
                cpu_to_le16(local->hw.conf.listen_interval);
        memcpy(mgmt->u.reassoc_req.current_ap, assoc_data->prev_bssid,
               ETH_ALEN);
    } else {
        skb_put(skb, 4);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                          IEEE80211_STYPE_ASSOC_REQ);
        mgmt->u.assoc_req.capab_info = cpu_to_le16(capab);
        mgmt->u.assoc_req.listen_interval =
                cpu_to_le16(local->hw.conf.listen_interval);
    }

    /* SSID */
    pos = skb_put(skb, 2 + assoc_data->ssid_len);
    *pos++ = WLAN_EID_SSID;
    *pos++ = assoc_data->ssid_len;
    memcpy(pos, assoc_data->ssid, assoc_data->ssid_len);

    /* add all rates which were marked to be used above */
    supp_rates_len = rates_len;
    if (supp_rates_len > 8)
        supp_rates_len = 8;

    pos = skb_put(skb, supp_rates_len + 2);
    *pos++ = WLAN_EID_SUPP_RATES;
    *pos++ = supp_rates_len;

    count = 0;
    for (i = 0; i < sband->n_bitrates; i++) {
        if (BIT(i) & rates) {
            int rate = sband->bitrates[i].bitrate;
            *pos++ = (u8) (rate / 5);
            if (++count == 8)
                break;
        }
    }

    if (rates_len > count) {
        pos = skb_put(skb, rates_len - count + 2);
        *pos++ = WLAN_EID_EXT_SUPP_RATES;
        *pos++ = rates_len - count;

        for (i++; i < sband->n_bitrates; i++) {
            if (BIT(i) & rates) {
                int rate = sband->bitrates[i].bitrate;
                *pos++ = (u8) (rate / 5);
            }
        }
    }

    if (capab & WLAN_CAPABILITY_SPECTRUM_MGMT) {
        /* 1. power capabilities */
        pos = skb_put(skb, 4);
        *pos++ = WLAN_EID_PWR_CAPABILITY;
        *pos++ = 2;
        *pos++ = 0; /* min tx power */
        *pos++ = local->oper_channel->max_power; /* max tx power */

        /* 2. supported channels */
        /* TODO: get this in reg domain format */
        pos = skb_put(skb, 2 * sband->n_channels + 2);
        *pos++ = WLAN_EID_SUPPORTED_CHANNELS;
        *pos++ = 2 * sband->n_channels;
        for (i = 0; i < sband->n_channels; i++) {
            *pos++ = ieee80211_frequency_to_channel(
                    sband->channels[i].center_freq);
            *pos++ = 1; /* one channel in the subband*/
        }
    }

    /* if present, add any custom IEs that go before HT */
    if (assoc_data->ie_len && assoc_data->ie) {
        static const u8 before_ht[] = {
            WLAN_EID_SSID,
            WLAN_EID_SUPP_RATES,
            WLAN_EID_EXT_SUPP_RATES,
            WLAN_EID_PWR_CAPABILITY,
            WLAN_EID_SUPPORTED_CHANNELS,
            WLAN_EID_RSN,
            WLAN_EID_QOS_CAPA,
            WLAN_EID_RRM_ENABLED_CAPABILITIES,
            WLAN_EID_MOBILITY_DOMAIN,
            WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
        };
        noffset = ieee80211_ie_split(assoc_data->ie, assoc_data->ie_len,
                         before_ht, ARRAY_SIZE(before_ht),
                         offset);
        pos = skb_put(skb, noffset - offset);
        memcpy(pos, assoc_data->ie + offset, noffset - offset);
        offset = noffset;
    }

    if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
        ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
                    sband, local->oper_channel, ifmgd->ap_smps);

    if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
        ieee80211_add_vht_ie(sdata, skb, sband);

    /* if present, add any custom non-vendor IEs that go after HT */
    if (assoc_data->ie_len && assoc_data->ie) {
        noffset = ieee80211_ie_split_vendor(assoc_data->ie,
                            assoc_data->ie_len,
                            offset);
        pos = skb_put(skb, noffset - offset);
        memcpy(pos, assoc_data->ie + offset, noffset - offset);
        offset = noffset;
    }

    if (assoc_data->wmm) {
        if (assoc_data->uapsd) {
            qos_info = ifmgd->uapsd_queues;
            qos_info |= (ifmgd->uapsd_max_sp_len <<
                     IEEE80211_WMM_IE_STA_QOSINFO_SP_SHIFT);
        } else {
            qos_info = 0;
        }

        pos = skb_put(skb, 9);
        *pos++ = WLAN_EID_VENDOR_SPECIFIC;
        *pos++ = 7; /* len */
        *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
        *pos++ = 0x50;
        *pos++ = 0xf2;
        *pos++ = 2; /* WME */
        *pos++ = 0; /* WME info */
        *pos++ = 1; /* WME ver */
        *pos++ = qos_info;
    }

    /* add any remaining custom (i.e. vendor specific here) IEs */
    if (assoc_data->ie_len && assoc_data->ie) {
        noffset = assoc_data->ie_len;
        pos = skb_put(skb, noffset - offset);
        memcpy(pos, assoc_data->ie + offset, noffset - offset);
    }

    drv_mgd_prepare_tx(local, sdata);

    IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
    ieee80211_tx_skb(sdata, skb);
}

void ieee80211_send_pspoll(struct ieee80211_local *local,
               struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_pspoll *pspoll;
    struct sk_buff *skb;

    skb = ieee80211_pspoll_get(&local->hw, &sdata->vif);
    if (!skb)
        return;

    pspoll = (struct ieee80211_pspoll *) skb->data;
    pspoll->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);

    IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
    ieee80211_tx_skb(sdata, skb);
}

void ieee80211_send_nullfunc(struct ieee80211_local *local,
                 struct ieee80211_sub_if_data *sdata,
                 int powersave)
{
    struct sk_buff *skb;
    struct ieee80211_hdr_3addr *nullfunc;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    skb = ieee80211_nullfunc_get(&local->hw, &sdata->vif);
    if (!skb)
        return;

    nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
    if (powersave)
        nullfunc->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);

    IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
    if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                IEEE80211_STA_CONNECTION_POLL))
        IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_USE_MINRATE;

    ieee80211_tx_skb(sdata, skb);
}

static void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local,
                      struct ieee80211_sub_if_data *sdata)
{
    struct sk_buff *skb;
    struct ieee80211_hdr *nullfunc;
    __le16 fc;

    if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
        return;

    skb = dev_alloc_skb(local->hw.extra_tx_headroom + 30);
    if (!skb)
        return;

    skb_reserve(skb, local->hw.extra_tx_headroom);

    nullfunc = (struct ieee80211_hdr *) skb_put(skb, 30);
    memset(nullfunc, 0, 30);
    fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
             IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
    nullfunc->frame_control = fc;
    memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN);
    memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
    memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN);
    memcpy(nullfunc->addr4, sdata->vif.addr, ETH_ALEN);

    IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
    ieee80211_tx_skb(sdata, skb);
}

/* spectrum management related things */
static void ieee80211_chswitch_work(struct work_struct *work)
{
    struct ieee80211_sub_if_data *sdata =
        container_of(work, struct ieee80211_sub_if_data, u.mgd.chswitch_work);
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    if (!ieee80211_sdata_running(sdata))
        return;

    mutex_lock(&ifmgd->mtx);
    if (!ifmgd->associated)
        goto out;

    sdata->local->oper_channel = sdata->local->csa_channel;
    if (!sdata->local->ops->channel_switch) {
        /* call "hw_config" only if doing sw channel switch */
        ieee80211_hw_config(sdata->local,
            IEEE80211_CONF_CHANGE_CHANNEL);
    } else {
        /* update the device channel directly */
        sdata->local->hw.conf.channel = sdata->local->oper_channel;
    }

    /* XXX: shouldn't really modify cfg80211-owned data! */
    ifmgd->associated->channel = sdata->local->oper_channel;

    /* XXX: wait for a beacon first? */
    ieee80211_wake_queues_by_reason(&sdata->local->hw,
                    IEEE80211_QUEUE_STOP_REASON_CSA);
 out:
    ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
    mutex_unlock(&ifmgd->mtx);
}

void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
{
    struct ieee80211_sub_if_data *sdata;
    struct ieee80211_if_managed *ifmgd;

    sdata = vif_to_sdata(vif);
    ifmgd = &sdata->u.mgd;

    trace_api_chswitch_done(sdata, success);
    if (!success) {
        sdata_info(sdata,
               "driver channel switch failed, disconnecting\n");
        ieee80211_queue_work(&sdata->local->hw,
                     &ifmgd->csa_connection_drop_work);
    } else {
        ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
    }
}
EXPORT_SYMBOL(ieee80211_chswitch_done);

static void ieee80211_chswitch_timer(unsigned long data)
{
    struct ieee80211_sub_if_data *sdata =
        (struct ieee80211_sub_if_data *) data;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    if (sdata->local->quiescing) {
        set_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running);
        return;
    }

    ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
}

void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                      struct ieee80211_channel_sw_ie *sw_elem,
                      struct ieee80211_bss *bss,
                      u64 timestamp)
{
    struct cfg80211_bss *cbss =
        container_of((void *)bss, struct cfg80211_bss, priv);
    struct ieee80211_channel *new_ch;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
                              cbss->channel->band);

    ASSERT_MGD_MTX(ifmgd);

    if (!ifmgd->associated)
        return;

    if (sdata->local->scanning)
        return;

    /* Disregard subsequent beacons if we are already running a timer
       processing a CSA */

    if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
        return;

    new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
    if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
        sdata_info(sdata,
               "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
               ifmgd->associated->bssid, new_freq);
        ieee80211_queue_work(&sdata->local->hw,
                     &ifmgd->csa_connection_drop_work);
        return;
    }

    sdata->local->csa_channel = new_ch;

    ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;

    if (sw_elem->mode)
        ieee80211_stop_queues_by_reason(&sdata->local->hw,
                IEEE80211_QUEUE_STOP_REASON_CSA);

    if (sdata->local->ops->channel_switch) {
        /* use driver's channel switch callback */
        struct ieee80211_channel_switch ch_switch = {
            .timestamp = timestamp,
            .block_tx = sw_elem->mode,
            .channel = new_ch,
            .count = sw_elem->count,
        };

        drv_channel_switch(sdata->local, &ch_switch);
        return;
    }

    /* channel switch handled in software */
    if (sw_elem->count <= 1)
        ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
    else
        mod_timer(&ifmgd->chswitch_timer,
              TU_TO_EXP_TIME(sw_elem->count *
                     cbss->beacon_interval));
}

static void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
                    struct ieee80211_channel *channel,
                    const u8 *country_ie, u8 country_ie_len,
                    const u8 *pwr_constr_elem)
{
    struct ieee80211_country_ie_triplet *triplet;
    int chan = ieee80211_frequency_to_channel(channel->center_freq);
    int i, chan_pwr, chan_increment, new_ap_level;
    bool have_chan_pwr = false;

    /* Invalid IE */
    if (country_ie_len % 2 || country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
        return;

    triplet = (void *)(country_ie + 3);
    country_ie_len -= 3;

    switch (channel->band) {
    default:
        WARN_ON_ONCE(1);
        /* fall through */
    case IEEE80211_BAND_2GHZ:
    case IEEE80211_BAND_60GHZ:
        chan_increment = 1;
        break;
    case IEEE80211_BAND_5GHZ:
        chan_increment = 4;
        break;
    }

    /* find channel */
    while (country_ie_len >= 3) {
        u8 first_channel = triplet->chans.first_channel;

        if (first_channel >= IEEE80211_COUNTRY_EXTENSION_ID)
            goto next;

        for (i = 0; i < triplet->chans.num_channels; i++) {
            if (first_channel + i * chan_increment == chan) {
                have_chan_pwr = true;
                chan_pwr = triplet->chans.max_power;
                break;
            }
        }
        if (have_chan_pwr)
            break;

 next:
        triplet++;
        country_ie_len -= 3;
    }

    if (!have_chan_pwr)
        return;

    new_ap_level = max_t(int, 0, chan_pwr - *pwr_constr_elem);

    if (sdata->local->ap_power_level == new_ap_level)
        return;

    sdata_info(sdata,
           "Limiting TX power to %d (%d - %d) dBm as advertised by %pM\n",
           new_ap_level, chan_pwr, *pwr_constr_elem,
           sdata->u.mgd.bssid);
    sdata->local->ap_power_level = new_ap_level;
    ieee80211_hw_config(sdata->local, 0);
}

void ieee80211_enable_dyn_ps(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_conf *conf = &local->hw.conf;

    WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION ||
        !(local->hw.flags & IEEE80211_HW_SUPPORTS_PS) ||
        (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS));

    local->disable_dynamic_ps = false;
    conf->dynamic_ps_timeout = local->dynamic_ps_user_timeout;
}
EXPORT_SYMBOL(ieee80211_enable_dyn_ps);

void ieee80211_disable_dyn_ps(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_conf *conf = &local->hw.conf;

    WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION ||
        !(local->hw.flags & IEEE80211_HW_SUPPORTS_PS) ||
        (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS));

    local->disable_dynamic_ps = true;
    conf->dynamic_ps_timeout = 0;
    del_timer_sync(&local->dynamic_ps_timer);
    ieee80211_queue_work(&local->hw,
                 &local->dynamic_ps_enable_work);
}
EXPORT_SYMBOL(ieee80211_disable_dyn_ps);

/* powersave */
static void ieee80211_enable_ps(struct ieee80211_local *local,
                struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_conf *conf = &local->hw.conf;

    /*
     * If we are scanning right now then the parameters will
     * take effect when scan finishes.
     */
    if (local->scanning)
        return;

    if (conf->dynamic_ps_timeout > 0 &&
        !(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)) {
        mod_timer(&local->dynamic_ps_timer, jiffies +
              msecs_to_jiffies(conf->dynamic_ps_timeout));
    } else {
        if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
            ieee80211_send_nullfunc(local, sdata, 1);

        if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
            (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
            return;

        conf->flags |= IEEE80211_CONF_PS;
        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
    }
}

static void ieee80211_change_ps(struct ieee80211_local *local)
{
    struct ieee80211_conf *conf = &local->hw.conf;

    if (local->ps_sdata) {
        ieee80211_enable_ps(local, local->ps_sdata);
    } else if (conf->flags & IEEE80211_CONF_PS) {
        conf->flags &= ~IEEE80211_CONF_PS;
        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
        del_timer_sync(&local->dynamic_ps_timer);
        cancel_work_sync(&local->dynamic_ps_enable_work);
    }
}

static bool ieee80211_powersave_allowed(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *mgd = &sdata->u.mgd;
    struct sta_info *sta = NULL;
    bool authorized = false;

    if (!mgd->powersave)
        return false;

    if (mgd->broken_ap)
        return false;

    if (!mgd->associated)
        return false;

    if (mgd->flags & (IEEE80211_STA_BEACON_POLL |
              IEEE80211_STA_CONNECTION_POLL))
        return false;

    rcu_read_lock();
    sta = sta_info_get(sdata, mgd->bssid);
    if (sta)
        authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
    rcu_read_unlock();

    return authorized;
}

/* need to hold RTNL or interface lock */
void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency)
{
    struct ieee80211_sub_if_data *sdata, *found = NULL;
    int count = 0;
    int timeout;

    if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS)) {
        local->ps_sdata = NULL;
        return;
    }

    list_for_each_entry(sdata, &local->interfaces, list) {
        if (!ieee80211_sdata_running(sdata))
            continue;
        if (sdata->vif.type == NL80211_IFTYPE_AP) {
            /* If an AP vif is found, then disable PS
             * by setting the count to zero thereby setting
             * ps_sdata to NULL.
             */
            count = 0;
            break;
        }
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
            continue;
        found = sdata;
        count++;
    }

    if (count == 1 && ieee80211_powersave_allowed(found)) {
        struct ieee80211_conf *conf = &local->hw.conf;
        s32 beaconint_us;

        if (latency < 0)
            latency = pm_qos_request(PM_QOS_NETWORK_LATENCY);

        beaconint_us = ieee80211_tu_to_usec(
                    found->vif.bss_conf.beacon_int);

        timeout = local->dynamic_ps_forced_timeout;
        if (timeout < 0) {
            /*
             * Go to full PSM if the user configures a very low
             * latency requirement.
             * The 2000 second value is there for compatibility
             * until the PM_QOS_NETWORK_LATENCY is configured
             * with real values.
             */
            if (latency > (1900 * USEC_PER_MSEC) &&
                latency != (2000 * USEC_PER_SEC))
                timeout = 0;
            else
                timeout = 100;
        }
        local->dynamic_ps_user_timeout = timeout;
        if (!local->disable_dynamic_ps)
            conf->dynamic_ps_timeout =
                local->dynamic_ps_user_timeout;

        if (beaconint_us > latency) {
            local->ps_sdata = NULL;
        } else {
            struct ieee80211_bss *bss;
            int maxslp = 1;
            u8 dtimper;

            bss = (void *)found->u.mgd.associated->priv;
            dtimper = bss->dtim_period;

            /* If the TIM IE is invalid, pretend the value is 1 */
            if (!dtimper)
                dtimper = 1;
            else if (dtimper > 1)
                maxslp = min_t(int, dtimper,
                            latency / beaconint_us);

            local->hw.conf.max_sleep_period = maxslp;
            local->hw.conf.ps_dtim_period = dtimper;
            local->ps_sdata = found;
        }
    } else {
        local->ps_sdata = NULL;
    }

    ieee80211_change_ps(local);
}

void ieee80211_recalc_ps_vif(struct ieee80211_sub_if_data *sdata)
{
    bool ps_allowed = ieee80211_powersave_allowed(sdata);

    if (sdata->vif.bss_conf.ps != ps_allowed) {
        sdata->vif.bss_conf.ps = ps_allowed;
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_PS);
    }
}

void ieee80211_dynamic_ps_disable_work(struct work_struct *work)
{
    struct ieee80211_local *local =
        container_of(work, struct ieee80211_local,
                 dynamic_ps_disable_work);

    if (local->hw.conf.flags & IEEE80211_CONF_PS) {
        local->hw.conf.flags &= ~IEEE80211_CONF_PS;
        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
    }

    ieee80211_wake_queues_by_reason(&local->hw,
                    IEEE80211_QUEUE_STOP_REASON_PS);
}

void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
{
    struct ieee80211_local *local =
        container_of(work, struct ieee80211_local,
                 dynamic_ps_enable_work);
    struct ieee80211_sub_if_data *sdata = local->ps_sdata;
    struct ieee80211_if_managed *ifmgd;
    unsigned long flags;
    int q;

    /* can only happen when PS was just disabled anyway */
    if (!sdata)
        return;

    ifmgd = &sdata->u.mgd;

    if (local->hw.conf.flags & IEEE80211_CONF_PS)
        return;

    if (!local->disable_dynamic_ps &&
        local->hw.conf.dynamic_ps_timeout > 0) {
        /* don't enter PS if TX frames are pending */
        if (drv_tx_frames_pending(local)) {
            mod_timer(&local->dynamic_ps_timer, jiffies +
                  msecs_to_jiffies(
                  local->hw.conf.dynamic_ps_timeout));
            return;
        }

        /*
         * transmission can be stopped by others which leads to
         * dynamic_ps_timer expiry. Postpone the ps timer if it
         * is not the actual idle state.
         */
        spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
        for (q = 0; q < local->hw.queues; q++) {
            if (local->queue_stop_reasons[q]) {
                spin_unlock_irqrestore(&local->queue_stop_reason_lock,
                               flags);
                mod_timer(&local->dynamic_ps_timer, jiffies +
                      msecs_to_jiffies(
                      local->hw.conf.dynamic_ps_timeout));
                return;
            }
        }
        spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
    }

    if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
        !(ifmgd->flags & IEEE80211_STA_NULLFUNC_ACKED)) {
        netif_tx_stop_all_queues(sdata->dev);

        if (drv_tx_frames_pending(local))
            mod_timer(&local->dynamic_ps_timer, jiffies +
                  msecs_to_jiffies(
                  local->hw.conf.dynamic_ps_timeout));
        else {
            ieee80211_send_nullfunc(local, sdata, 1);
            /* Flush to get the tx status of nullfunc frame */
            drv_flush(local, false);
        }
    }

    if (!((local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
          (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) ||
        (ifmgd->flags & IEEE80211_STA_NULLFUNC_ACKED)) {
        ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
        local->hw.conf.flags |= IEEE80211_CONF_PS;
        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
    }

    if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
        netif_tx_wake_all_queues(sdata->dev);
}

void ieee80211_dynamic_ps_timer(unsigned long data)
{
    struct ieee80211_local *local = (void *) data;

    if (local->quiescing || local->suspended)
        return;

    ieee80211_queue_work(&local->hw, &local->dynamic_ps_enable_work);
}

/* MLME */
static bool ieee80211_sta_wmm_params(struct ieee80211_local *local,
                     struct ieee80211_sub_if_data *sdata,
                     u8 *wmm_param, size_t wmm_param_len)
{
    struct ieee80211_tx_queue_params params;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    size_t left;
    int count;
    u8 *pos, uapsd_queues = 0;

    if (!local->ops->conf_tx)
        return false;

    if (local->hw.queues < IEEE80211_NUM_ACS)
        return false;

    if (!wmm_param)
        return false;

    if (wmm_param_len < 8 || wmm_param[5] /* version */ != 1)
        return false;

    if (ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED)
        uapsd_queues = ifmgd->uapsd_queues;

    count = wmm_param[6] & 0x0f;
    if (count == ifmgd->wmm_last_param_set)
        return false;
    ifmgd->wmm_last_param_set = count;

    pos = wmm_param + 8;
    left = wmm_param_len - 8;

    memset(&params, 0, sizeof(params));

    sdata->wmm_acm = 0;
    for (; left >= 4; left -= 4, pos += 4) {
        int aci = (pos[0] >> 5) & 0x03;
        int acm = (pos[0] >> 4) & 0x01;
        bool uapsd = false;
        int queue;

        switch (aci) {
        case 1: /* AC_BK */
            queue = 3;
            if (acm)
                sdata->wmm_acm |= BIT(1) | BIT(2); /* BK/- */
            if (uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BK)
                uapsd = true;
            break;
        case 2: /* AC_VI */
            queue = 1;
            if (acm)
                sdata->wmm_acm |= BIT(4) | BIT(5); /* CL/VI */
            if (uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VI)
                uapsd = true;
            break;
        case 3: /* AC_VO */
            queue = 0;
            if (acm)
                sdata->wmm_acm |= BIT(6) | BIT(7); /* VO/NC */
            if (uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
                uapsd = true;
            break;
        case 0: /* AC_BE */
        default:
            queue = 2;
            if (acm)
                sdata->wmm_acm |= BIT(0) | BIT(3); /* BE/EE */
            if (uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BE)
                uapsd = true;
            break;
        }

        params.aifs = pos[0] & 0x0f;
        params.cw_max = ecw2cw((pos[1] & 0xf0) >> 4);
        params.cw_min = ecw2cw(pos[1] & 0x0f);
        params.txop = get_unaligned_le16(pos + 2);
        params.uapsd = uapsd;

        mlme_dbg(sdata,
             "WMM queue=%d aci=%d acm=%d aifs=%d cWmin=%d cWmax=%d txop=%d uapsd=%d\n",
             queue, aci, acm,
             params.aifs, params.cw_min, params.cw_max,
             params.txop, params.uapsd);
        sdata->tx_conf[queue] = params;
        if (drv_conf_tx(local, sdata, queue, &params))
            sdata_err(sdata,
                  "failed to set TX queue parameters for queue %d\n",
                  queue);
    }

    /* enable WMM or activate new settings */
    sdata->vif.bss_conf.qos = true;
    return true;
}

static void __ieee80211_stop_poll(struct ieee80211_sub_if_data *sdata)
{
    lockdep_assert_held(&sdata->local->mtx);

    sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                IEEE80211_STA_BEACON_POLL);
    ieee80211_run_deferred_scan(sdata->local);
}

static void ieee80211_stop_poll(struct ieee80211_sub_if_data *sdata)
{
    mutex_lock(&sdata->local->mtx);
    __ieee80211_stop_poll(sdata);
    mutex_unlock(&sdata->local->mtx);
}

static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
                       u16 capab, bool erp_valid, u8 erp)
{
    struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
    u32 changed = 0;
    bool use_protection;
    bool use_short_preamble;
    bool use_short_slot;

    if (erp_valid) {
        use_protection = (erp & WLAN_ERP_USE_PROTECTION) != 0;
        use_short_preamble = (erp & WLAN_ERP_BARKER_PREAMBLE) == 0;
    } else {
        use_protection = false;
        use_short_preamble = !!(capab & WLAN_CAPABILITY_SHORT_PREAMBLE);
    }

    use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
    if (sdata->local->oper_channel->band == IEEE80211_BAND_5GHZ)
        use_short_slot = true;

    if (use_protection != bss_conf->use_cts_prot) {
        bss_conf->use_cts_prot = use_protection;
        changed |= BSS_CHANGED_ERP_CTS_PROT;
    }

    if (use_short_preamble != bss_conf->use_short_preamble) {
        bss_conf->use_short_preamble = use_short_preamble;
        changed |= BSS_CHANGED_ERP_PREAMBLE;
    }

    if (use_short_slot != bss_conf->use_short_slot) {
        bss_conf->use_short_slot = use_short_slot;
        changed |= BSS_CHANGED_ERP_SLOT;
    }

    return changed;
}

static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
                     struct cfg80211_bss *cbss,
                     u32 bss_info_changed)
{
    struct ieee80211_bss *bss = (void *)cbss->priv;
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;

    bss_info_changed |= BSS_CHANGED_ASSOC;
    bss_info_changed |= ieee80211_handle_bss_capability(sdata,
        bss_conf->assoc_capability, bss->has_erp_value, bss->erp_value);

    sdata->u.mgd.beacon_timeout = usecs_to_jiffies(ieee80211_tu_to_usec(
        IEEE80211_BEACON_LOSS_COUNT * bss_conf->beacon_int));

    sdata->u.mgd.associated = cbss;
    memcpy(sdata->u.mgd.bssid, cbss->bssid, ETH_ALEN);

    sdata->u.mgd.flags |= IEEE80211_STA_RESET_SIGNAL_AVE;

    /* just to be sure */
    ieee80211_stop_poll(sdata);

    ieee80211_led_assoc(local, 1);

    if (local->hw.flags & IEEE80211_HW_NEED_DTIM_PERIOD)
        bss_conf->dtim_period = bss->dtim_period;
    else
        bss_conf->dtim_period = 0;

    bss_conf->assoc = 1;

    /* Tell the driver to monitor connection quality (if supported) */
    if (sdata->vif.driver_flags & IEEE80211_VIF_SUPPORTS_CQM_RSSI &&
        bss_conf->cqm_rssi_thold)
        bss_info_changed |= BSS_CHANGED_CQM;

    /* Enable ARP filtering */
    if (bss_conf->arp_filter_enabled != sdata->arp_filter_state) {
        bss_conf->arp_filter_enabled = sdata->arp_filter_state;
        bss_info_changed |= BSS_CHANGED_ARP_FILTER;
    }

    ieee80211_bss_info_change_notify(sdata, bss_info_changed);

    mutex_lock(&local->iflist_mtx);
    ieee80211_recalc_ps(local, -1);
    mutex_unlock(&local->iflist_mtx);

    ieee80211_recalc_smps(local);
    ieee80211_recalc_ps_vif(sdata);

    netif_tx_start_all_queues(sdata->dev);
    netif_carrier_on(sdata->dev);
}

static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
                   u16 stype, u16 reason, bool tx,
                   u8 *frame_buf)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;
    struct sta_info *sta;
    u32 changed = 0;

    ASSERT_MGD_MTX(ifmgd);

    if (WARN_ON_ONCE(tx && !frame_buf))
        return;

    if (WARN_ON(!ifmgd->associated))
        return;

    ieee80211_stop_poll(sdata);

    ifmgd->associated = NULL;

    /*
     * we need to commit the associated = NULL change because the
     * scan code uses that to determine whether this iface should
     * go to/wake up from powersave or not -- and could otherwise
     * wake the queues erroneously.
     */
    smp_mb();

    /*
     * Thus, we can only afterwards stop the queues -- to account
     * for the case where another CPU is finishing a scan at this
     * time -- we don't want the scan code to enable queues.
     */

    netif_tx_stop_all_queues(sdata->dev);
    netif_carrier_off(sdata->dev);

    mutex_lock(&local->sta_mtx);
    sta = sta_info_get(sdata, ifmgd->bssid);
    if (sta) {
        set_sta_flag(sta, WLAN_STA_BLOCK_BA);
        ieee80211_sta_tear_down_BA_sessions(sta, false);
    }
    mutex_unlock(&local->sta_mtx);

    /*
     * if we want to get out of ps before disassoc (why?) we have
     * to do it before sending disassoc, as otherwise the null-packet
     * won't be valid.
     */
    if (local->hw.conf.flags & IEEE80211_CONF_PS) {
        local->hw.conf.flags &= ~IEEE80211_CONF_PS;
        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
    }
    local->ps_sdata = NULL;

    /* disable per-vif ps */
    ieee80211_recalc_ps_vif(sdata);

    /* flush out any pending frame (e.g. DELBA) before deauth/disassoc */
    if (tx)
        drv_flush(local, false);

    /* deauthenticate/disassociate now */
    if (tx || frame_buf)
        ieee80211_send_deauth_disassoc(sdata, ifmgd->bssid, stype,
                           reason, tx, frame_buf);

    /* flush out frame */
    if (tx)
        drv_flush(local, false);

    /* clear bssid only after building the needed mgmt frames */
    memset(ifmgd->bssid, 0, ETH_ALEN);

    /* remove AP and TDLS peers */
    sta_info_flush(local, sdata);

    /* finally reset all BSS / config parameters */
    changed |= ieee80211_reset_erp_info(sdata);

    ieee80211_led_assoc(local, 0);
    changed |= BSS_CHANGED_ASSOC;
    sdata->vif.bss_conf.assoc = false;

    /* on the next assoc, re-program HT parameters */
    memset(&ifmgd->ht_capa, 0, sizeof(ifmgd->ht_capa));
    memset(&ifmgd->ht_capa_mask, 0, sizeof(ifmgd->ht_capa_mask));

    local->ap_power_level = 0;

    del_timer_sync(&local->dynamic_ps_timer);
    cancel_work_sync(&local->dynamic_ps_enable_work);

    /* Disable ARP filtering */
    if (sdata->vif.bss_conf.arp_filter_enabled) {
        sdata->vif.bss_conf.arp_filter_enabled = false;
        changed |= BSS_CHANGED_ARP_FILTER;
    }

    sdata->vif.bss_conf.qos = false;
    changed |= BSS_CHANGED_QOS;

    /* The BSSID (not really interesting) and HT changed */
    changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
    ieee80211_bss_info_change_notify(sdata, changed);

    /* channel(_type) changes are handled by ieee80211_hw_config */
    WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
    ieee80211_hw_config(local, 0);

    /* disassociated - set to defaults now */
    ieee80211_set_wmm_default(sdata, false);

    del_timer_sync(&sdata->u.mgd.conn_mon_timer);
    del_timer_sync(&sdata->u.mgd.bcn_mon_timer);
    del_timer_sync(&sdata->u.mgd.timer);
    del_timer_sync(&sdata->u.mgd.chswitch_timer);

    sdata->u.mgd.timers_running = 0;
}

void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
                 struct ieee80211_hdr *hdr)
{
    /*
     * We can postpone the mgd.timer whenever receiving unicast frames
     * from AP because we know that the connection is working both ways
     * at that time. But multicast frames (and hence also beacons) must
     * be ignored here, because we need to trigger the timer during
     * data idle periods for sending the periodic probe request to the
     * AP we're connected to.
     */
    if (is_multicast_ether_addr(hdr->addr1))
        return;

    ieee80211_sta_reset_conn_monitor(sdata);
}

static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;

    mutex_lock(&local->mtx);
    if (!(ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                  IEEE80211_STA_CONNECTION_POLL))) {
        mutex_unlock(&local->mtx);
        return;
    }

    __ieee80211_stop_poll(sdata);

    mutex_lock(&local->iflist_mtx);
    ieee80211_recalc_ps(local, -1);
    mutex_unlock(&local->iflist_mtx);

    if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
        goto out;

    /*
     * We've received a probe response, but are not sure whether
     * we have or will be receiving any beacons or data, so let's
     * schedule the timers again, just in case.
     */
    ieee80211_sta_reset_beacon_monitor(sdata);

    mod_timer(&ifmgd->conn_mon_timer,
          round_jiffies_up(jiffies +
                   IEEE80211_CONNECTION_IDLE_TIME));
out:
    mutex_unlock(&local->mtx);
}

void ieee80211_sta_tx_notify(struct ieee80211_sub_if_data *sdata,
                 struct ieee80211_hdr *hdr, bool ack)
{
    if (!ieee80211_is_data(hdr->frame_control))
        return;

    if (ack)
        ieee80211_sta_reset_conn_monitor(sdata);

    if (ieee80211_is_nullfunc(hdr->frame_control) &&
        sdata->u.mgd.probe_send_count > 0) {
        if (ack)
            sdata->u.mgd.probe_send_count = 0;
        else
            sdata->u.mgd.nullfunc_failed = true;
        ieee80211_queue_work(&sdata->local->hw, &sdata->work);
    }
}

static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    const u8 *ssid;
    u8 *dst = ifmgd->associated->bssid;
    u8 unicast_limit = max(1, max_probe_tries - 3);

    /*
     * Try sending broadcast probe requests for the last three
     * probe requests after the first ones failed since some
     * buggy APs only support broadcast probe requests.
     */
    if (ifmgd->probe_send_count >= unicast_limit)
        dst = NULL;

    /*
     * When the hardware reports an accurate Tx ACK status, it's
     * better to send a nullfunc frame instead of a probe request,
     * as it will kick us off the AP quickly if we aren't associated
     * anymore. The timeout will be reset if the frame is ACKed by
     * the AP.
     */
    ifmgd->probe_send_count++;

    if (sdata->local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
        ifmgd->nullfunc_failed = false;
        ieee80211_send_nullfunc(sdata->local, sdata, 0);
    } else {
        int ssid_len;

        ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
        if (WARN_ON_ONCE(ssid == NULL))
            ssid_len = 0;
        else
            ssid_len = ssid[1];

        ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
                     0, (u32) -1, true, false,
                     ifmgd->associated->channel);
    }

    ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
    run_again(ifmgd, ifmgd->probe_timeout);
    if (sdata->local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
        drv_flush(sdata->local, false);
}

static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
                   bool beacon)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    bool already = false;

    if (!ieee80211_sdata_running(sdata))
        return;

    mutex_lock(&ifmgd->mtx);

    if (!ifmgd->associated)
        goto out;

    mutex_lock(&sdata->local->mtx);

    if (sdata->local->tmp_channel || sdata->local->scanning) {
        mutex_unlock(&sdata->local->mtx);
        goto out;
    }

    if (beacon)
        mlme_dbg_ratelimited(sdata,
                     "detected beacon loss from AP - sending probe request\n");

    ieee80211_cqm_rssi_notify(&sdata->vif,
        NL80211_CQM_RSSI_BEACON_LOSS_EVENT, GFP_KERNEL);

    /*
     * The driver/our work has already reported this event or the
     * connection monitoring has kicked in and we have already sent
     * a probe request. Or maybe the AP died and the driver keeps
     * reporting until we disassociate...
     *
     * In either case we have to ignore the current call to this
     * function (except for setting the correct probe reason bit)
     * because otherwise we would reset the timer every time and
     * never check whether we received a probe response!
     */
    if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                IEEE80211_STA_CONNECTION_POLL))
        already = true;

    if (beacon)
        ifmgd->flags |= IEEE80211_STA_BEACON_POLL;
    else
        ifmgd->flags |= IEEE80211_STA_CONNECTION_POLL;

    mutex_unlock(&sdata->local->mtx);

    if (already)
        goto out;

    mutex_lock(&sdata->local->iflist_mtx);
    ieee80211_recalc_ps(sdata->local, -1);
    mutex_unlock(&sdata->local->iflist_mtx);

    ifmgd->probe_send_count = 0;
    ieee80211_mgd_probe_ap_send(sdata);
 out:
    mutex_unlock(&ifmgd->mtx);
}

struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
                      struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct cfg80211_bss *cbss;
    struct sk_buff *skb;
    const u8 *ssid;
    int ssid_len;

    if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
        return NULL;

    ASSERT_MGD_MTX(ifmgd);

    if (ifmgd->associated)
        cbss = ifmgd->associated;
    else if (ifmgd->auth_data)
        cbss = ifmgd->auth_data->bss;
    else if (ifmgd->assoc_data)
        cbss = ifmgd->assoc_data->bss;
    else
        return NULL;

    ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID);
    if (WARN_ON_ONCE(ssid == NULL))
        ssid_len = 0;
    else
        ssid_len = ssid[1];

    skb = ieee80211_build_probe_req(sdata, cbss->bssid,
                    (u32) -1,
                    sdata->local->oper_channel,
                    ssid + 2, ssid_len,
                    NULL, 0, true);

    return skb;
}
EXPORT_SYMBOL(ieee80211_ap_probereq_get);

static void __ieee80211_disconnect(struct ieee80211_sub_if_data *sdata,
                   bool transmit_frame)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;
    u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];

    mutex_lock(&ifmgd->mtx);
    if (!ifmgd->associated) {
        mutex_unlock(&ifmgd->mtx);
        return;
    }

    ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
                   WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
                   transmit_frame, frame_buf);
    ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
    mutex_unlock(&ifmgd->mtx);

    /*
     * must be outside lock due to cfg80211,
     * but that's not a problem.
     */
    cfg80211_send_deauth(sdata->dev, frame_buf, IEEE80211_DEAUTH_FRAME_LEN);

    mutex_lock(&local->mtx);
    ieee80211_recalc_idle(local);
    mutex_unlock(&local->mtx);
}

static void ieee80211_beacon_connection_loss_work(struct work_struct *work)
{
    struct ieee80211_sub_if_data *sdata =
        container_of(work, struct ieee80211_sub_if_data,
                 u.mgd.beacon_connection_loss_work);
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct sta_info *sta;

    if (ifmgd->associated) {
        rcu_read_lock();
        sta = sta_info_get(sdata, ifmgd->bssid);
        if (sta)
            sta->beacon_loss_count++;
        rcu_read_unlock();
    }

    if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR) {
        sdata_info(sdata, "Connection to AP %pM lost\n",
               ifmgd->bssid);
        __ieee80211_disconnect(sdata, false);
    } else {
        ieee80211_mgd_probe_ap(sdata, true);
    }
}

static void ieee80211_csa_connection_drop_work(struct work_struct *work)
{
    struct ieee80211_sub_if_data *sdata =
        container_of(work, struct ieee80211_sub_if_data,
                 u.mgd.csa_connection_drop_work);

    ieee80211_wake_queues_by_reason(&sdata->local->hw,
                    IEEE80211_QUEUE_STOP_REASON_CSA);
    __ieee80211_disconnect(sdata, true);
}

void ieee80211_beacon_loss(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_hw *hw = &sdata->local->hw;

    trace_api_beacon_loss(sdata);

    WARN_ON(hw->flags & IEEE80211_HW_CONNECTION_MONITOR);
    ieee80211_queue_work(hw, &sdata->u.mgd.beacon_connection_loss_work);
}
EXPORT_SYMBOL(ieee80211_beacon_loss);

void ieee80211_connection_loss(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_hw *hw = &sdata->local->hw;

    trace_api_connection_loss(sdata);

    WARN_ON(!(hw->flags & IEEE80211_HW_CONNECTION_MONITOR));
    ieee80211_queue_work(hw, &sdata->u.mgd.beacon_connection_loss_work);
}
EXPORT_SYMBOL(ieee80211_connection_loss);


static void ieee80211_destroy_auth_data(struct ieee80211_sub_if_data *sdata,
                    bool assoc)
{
    struct ieee80211_mgd_auth_data *auth_data = sdata->u.mgd.auth_data;

    lockdep_assert_held(&sdata->u.mgd.mtx);

    if (!assoc) {
        sta_info_destroy_addr(sdata, auth_data->bss->bssid);

        memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
    }

    cfg80211_put_bss(auth_data->bss);
    kfree(auth_data);
    sdata->u.mgd.auth_data = NULL;
}

static void ieee80211_auth_challenge(struct ieee80211_sub_if_data *sdata,
                     struct ieee80211_mgmt *mgmt, size_t len)
{
    struct ieee80211_mgd_auth_data *auth_data = sdata->u.mgd.auth_data;
    u8 *pos;
    struct ieee802_11_elems elems;

    pos = mgmt->u.auth.variable;
    ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);
    if (!elems.challenge)
        return;
    auth_data->expected_transaction = 4;
    drv_mgd_prepare_tx(sdata->local, sdata);
    ieee80211_send_auth(sdata, 3, auth_data->algorithm,
                elems.challenge - 2, elems.challenge_len + 2,
                auth_data->bss->bssid, auth_data->bss->bssid,
                auth_data->key, auth_data->key_len,
                auth_data->key_idx);
}

static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata,
               struct ieee80211_mgmt *mgmt, size_t len)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    u8 bssid[ETH_ALEN];
    u16 auth_alg, auth_transaction, status_code;
    struct sta_info *sta;

    lockdep_assert_held(&ifmgd->mtx);

    if (len < 24 + 6)
        return RX_MGMT_NONE;

    if (!ifmgd->auth_data || ifmgd->auth_data->done)
        return RX_MGMT_NONE;

    memcpy(bssid, ifmgd->auth_data->bss->bssid, ETH_ALEN);

    if (!ether_addr_equal(bssid, mgmt->bssid))
        return RX_MGMT_NONE;

    auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
    auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
    status_code = le16_to_cpu(mgmt->u.auth.status_code);

    if (auth_alg != ifmgd->auth_data->algorithm ||
        auth_transaction != ifmgd->auth_data->expected_transaction)
        return RX_MGMT_NONE;

    if (status_code != WLAN_STATUS_SUCCESS) {
        sdata_info(sdata, "%pM denied authentication (status %d)\n",
               mgmt->sa, status_code);
        ieee80211_destroy_auth_data(sdata, false);
        return RX_MGMT_CFG80211_RX_AUTH;
    }

    switch (ifmgd->auth_data->algorithm) {
    case WLAN_AUTH_OPEN:
    case WLAN_AUTH_LEAP:
    case WLAN_AUTH_FT:
        break;
    case WLAN_AUTH_SHARED_KEY:
        if (ifmgd->auth_data->expected_transaction != 4) {
            ieee80211_auth_challenge(sdata, mgmt, len);
            /* need another frame */
            return RX_MGMT_NONE;
        }
        break;
    default:
        WARN_ONCE(1, "invalid auth alg %d",
              ifmgd->auth_data->algorithm);
        return RX_MGMT_NONE;
    }

    sdata_info(sdata, "authenticated\n");
    ifmgd->auth_data->done = true;
    ifmgd->auth_data->timeout = jiffies + IEEE80211_AUTH_WAIT_ASSOC;
    run_again(ifmgd, ifmgd->auth_data->timeout);

    /* move station state to auth */
    mutex_lock(&sdata->local->sta_mtx);
    sta = sta_info_get(sdata, bssid);
    if (!sta) {
        WARN_ONCE(1, "%s: STA %pM not found", sdata->name, bssid);
        goto out_err;
    }
    if (sta_info_move_state(sta, IEEE80211_STA_AUTH)) {
        sdata_info(sdata, "failed moving %pM to auth\n", bssid);
        goto out_err;
    }
    mutex_unlock(&sdata->local->sta_mtx);

    return RX_MGMT_CFG80211_RX_AUTH;
 out_err:
    mutex_unlock(&sdata->local->sta_mtx);
    /* ignore frame -- wait for timeout */
    return RX_MGMT_NONE;
}


static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata,
             struct ieee80211_mgmt *mgmt, size_t len)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    const u8 *bssid = NULL;
    u16 reason_code;

    lockdep_assert_held(&ifmgd->mtx);

    if (len < 24 + 2)
        return RX_MGMT_NONE;

    if (!ifmgd->associated ||
        !ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid))
        return RX_MGMT_NONE;

    bssid = ifmgd->associated->bssid;

    reason_code = le16_to_cpu(mgmt->u.deauth.reason_code);

    sdata_info(sdata, "deauthenticated from %pM (Reason: %u)\n",
           bssid, reason_code);

    ieee80211_set_disassoc(sdata, 0, 0, false, NULL);

    mutex_lock(&sdata->local->mtx);
    ieee80211_recalc_idle(sdata->local);
    mutex_unlock(&sdata->local->mtx);

    return RX_MGMT_CFG80211_DEAUTH;
}


static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata,
               struct ieee80211_mgmt *mgmt, size_t len)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    u16 reason_code;

    lockdep_assert_held(&ifmgd->mtx);

    if (len < 24 + 2)
        return RX_MGMT_NONE;

    if (!ifmgd->associated ||
        !ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid))
        return RX_MGMT_NONE;

    reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code);

    sdata_info(sdata, "disassociated from %pM (Reason: %u)\n",
           mgmt->sa, reason_code);

    ieee80211_set_disassoc(sdata, 0, 0, false, NULL);

    mutex_lock(&sdata->local->mtx);
    ieee80211_recalc_idle(sdata->local);
    mutex_unlock(&sdata->local->mtx);

    return RX_MGMT_CFG80211_DISASSOC;
}

static void ieee80211_get_rates(struct ieee80211_supported_band *sband,
                u8 *supp_rates, unsigned int supp_rates_len,
                u32 *rates, u32 *basic_rates,
                bool *have_higher_than_11mbit,
                int *min_rate, int *min_rate_index)
{
    int i, j;

    for (i = 0; i < supp_rates_len; i++) {
        int rate = (supp_rates[i] & 0x7f) * 5;
        bool is_basic = !!(supp_rates[i] & 0x80);

        if (rate > 110)
            *have_higher_than_11mbit = true;

        /*
         * BSS_MEMBERSHIP_SELECTOR_HT_PHY is defined in 802.11n-2009
         * 7.3.2.2 as a magic value instead of a rate. Hence, skip it.
         *
         * Note: Even through the membership selector and the basic
         *   rate flag share the same bit, they are not exactly
         *   the same.
         */
        if (!!(supp_rates[i] & 0x80) &&
            (supp_rates[i] & 0x7f) == BSS_MEMBERSHIP_SELECTOR_HT_PHY)
            continue;

        for (j = 0; j < sband->n_bitrates; j++) {
            if (sband->bitrates[j].bitrate == rate) {
                *rates |= BIT(j);
                if (is_basic)
                    *basic_rates |= BIT(j);
                if (rate < *min_rate) {
                    *min_rate = rate;
                    *min_rate_index = j;
                }
                break;
            }
        }
    }
}

static void ieee80211_destroy_assoc_data(struct ieee80211_sub_if_data *sdata,
                     bool assoc)
{
    struct ieee80211_mgd_assoc_data *assoc_data = sdata->u.mgd.assoc_data;

    lockdep_assert_held(&sdata->u.mgd.mtx);

    if (!assoc) {
        sta_info_destroy_addr(sdata, assoc_data->bss->bssid);

        memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
    }

    kfree(assoc_data);
    sdata->u.mgd.assoc_data = NULL;
}

static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata,
                    struct cfg80211_bss *cbss,
                    struct ieee80211_mgmt *mgmt, size_t len)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_supported_band *sband;
    struct sta_info *sta;
    u8 *pos;
    u16 capab_info, aid;
    struct ieee802_11_elems elems;
    struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
    u32 changed = 0;
    int err;

    /* AssocResp and ReassocResp have identical structure */

    aid = le16_to_cpu(mgmt->u.assoc_resp.aid);
    capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info);

    if ((aid & (BIT(15) | BIT(14))) != (BIT(15) | BIT(14)))
        sdata_info(sdata, "invalid AID value 0x%x; bits 15:14 not set\n",
               aid);
    aid &= ~(BIT(15) | BIT(14));

    ifmgd->broken_ap = false;

    if (aid == 0 || aid > IEEE80211_MAX_AID) {
        sdata_info(sdata, "invalid AID value %d (out of range), turn off PS\n",
               aid);
        aid = 0;
        ifmgd->broken_ap = true;
    }

    pos = mgmt->u.assoc_resp.variable;
    ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);

    if (!elems.supp_rates) {
        sdata_info(sdata, "no SuppRates element in AssocResp\n");
        return false;
    }

    ifmgd->aid = aid;

    mutex_lock(&sdata->local->sta_mtx);
    /*
     * station info was already allocated and inserted before
     * the association and should be available to us
     */
    sta = sta_info_get(sdata, cbss->bssid);
    if (WARN_ON(!sta)) {
        mutex_unlock(&sdata->local->sta_mtx);
        return false;
    }

    sband = local->hw.wiphy->bands[local->oper_channel->band];

    if (elems.ht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
        ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
                elems.ht_cap_elem, &sta->sta.ht_cap);

    sta->supports_40mhz =
        sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40;

    rate_control_rate_init(sta);

    if (ifmgd->flags & IEEE80211_STA_MFP_ENABLED)
        set_sta_flag(sta, WLAN_STA_MFP);

    if (elems.wmm_param)
        set_sta_flag(sta, WLAN_STA_WME);

    err = sta_info_move_state(sta, IEEE80211_STA_AUTH);
    if (!err)
        err = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
    if (!err && !(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
        err = sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
    if (err) {
        sdata_info(sdata,
               "failed to move station %pM to desired state\n",
               sta->sta.addr);
        WARN_ON(__sta_info_destroy(sta));
        mutex_unlock(&sdata->local->sta_mtx);
        return false;
    }

    mutex_unlock(&sdata->local->sta_mtx);

    /*
     * Always handle WMM once after association regardless
     * of the first value the AP uses. Setting -1 here has
     * that effect because the AP values is an unsigned
     * 4-bit value.
     */
    ifmgd->wmm_last_param_set = -1;

    if (elems.wmm_param)
        ieee80211_sta_wmm_params(local, sdata, elems.wmm_param,
                     elems.wmm_param_len);
    else
        ieee80211_set_wmm_default(sdata, false);
    changed |= BSS_CHANGED_QOS;

    if (elems.ht_operation && elems.wmm_param &&
        !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
        changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
                          cbss->bssid, false);

    /* set AID and assoc capability,
     * ieee80211_set_associated() will tell the driver */
    bss_conf->aid = aid;
    bss_conf->assoc_capability = capab_info;
    ieee80211_set_associated(sdata, cbss, changed);

    /*
     * If we're using 4-addr mode, let the AP know that we're
     * doing so, so that it can create the STA VLAN on its side
     */
    if (ifmgd->use_4addr)
        ieee80211_send_4addr_nullfunc(local, sdata);

    /*
     * Start timer to probe the connection to the AP now.
     * Also start the timer that will detect beacon loss.
     */
    ieee80211_sta_rx_notify(sdata, (struct ieee80211_hdr *)mgmt);
    ieee80211_sta_reset_beacon_monitor(sdata);

    return true;
}

static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
                 struct ieee80211_mgmt *mgmt, size_t len,
                 struct cfg80211_bss **bss)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_mgd_assoc_data *assoc_data = ifmgd->assoc_data;
    u16 capab_info, status_code, aid;
    struct ieee802_11_elems elems;
    u8 *pos;
    bool reassoc;

    lockdep_assert_held(&ifmgd->mtx);

    if (!assoc_data)
        return RX_MGMT_NONE;
    if (!ether_addr_equal(assoc_data->bss->bssid, mgmt->bssid))
        return RX_MGMT_NONE;

    /*
     * AssocResp and ReassocResp have identical structure, so process both
     * of them in this function.
     */

    if (len < 24 + 6)
        return RX_MGMT_NONE;

    reassoc = ieee80211_is_reassoc_req(mgmt->frame_control);
    capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info);
    status_code = le16_to_cpu(mgmt->u.assoc_resp.status_code);
    aid = le16_to_cpu(mgmt->u.assoc_resp.aid);

    sdata_info(sdata,
           "RX %sssocResp from %pM (capab=0x%x status=%d aid=%d)\n",
           reassoc ? "Rea" : "A", mgmt->sa,
           capab_info, status_code, (u16)(aid & ~(BIT(15) | BIT(14))));

    pos = mgmt->u.assoc_resp.variable;
    ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);

    if (status_code == WLAN_STATUS_ASSOC_REJECTED_TEMPORARILY &&
        elems.timeout_int && elems.timeout_int_len == 5 &&
        elems.timeout_int[0] == WLAN_TIMEOUT_ASSOC_COMEBACK) {
        u32 tu, ms;
        tu = get_unaligned_le32(elems.timeout_int + 1);
        ms = tu * 1024 / 1000;
        sdata_info(sdata,
               "%pM rejected association temporarily; comeback duration %u TU (%u ms)\n",
               mgmt->sa, tu, ms);
        assoc_data->timeout = jiffies + msecs_to_jiffies(ms);
        if (ms > IEEE80211_ASSOC_TIMEOUT)
            run_again(ifmgd, assoc_data->timeout);
        return RX_MGMT_NONE;
    }

    *bss = assoc_data->bss;

    if (status_code != WLAN_STATUS_SUCCESS) {
        sdata_info(sdata, "%pM denied association (code=%d)\n",
               mgmt->sa, status_code);
        ieee80211_destroy_assoc_data(sdata, false);
    } else {
        if (!ieee80211_assoc_success(sdata, *bss, mgmt, len)) {
            /* oops -- internal error -- send timeout for now */
            ieee80211_destroy_assoc_data(sdata, false);
            cfg80211_put_bss(*bss);
            return RX_MGMT_CFG80211_ASSOC_TIMEOUT;
        }
        sdata_info(sdata, "associated\n");

        /*
         * destroy assoc_data afterwards, as otherwise an idle
         * recalc after assoc_data is NULL but before associated
         * is set can cause the interface to go idle
         */
        ieee80211_destroy_assoc_data(sdata, true);
    }

    return RX_MGMT_CFG80211_RX_ASSOC;
}
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                  struct ieee80211_mgmt *mgmt,
                  size_t len,
                  struct ieee80211_rx_status *rx_status,
                  struct ieee802_11_elems *elems,
                  bool beacon)
{
    struct ieee80211_local *local = sdata->local;
    int freq;
    struct ieee80211_bss *bss;
    struct ieee80211_channel *channel;
    bool need_ps = false;

    if (sdata->u.mgd.associated &&
        ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid)) {
        bss = (void *)sdata->u.mgd.associated->priv;
        /* not previously set so we may need to recalc */
        need_ps = !bss->dtim_period;
    }

    if (elems->ds_params && elems->ds_params_len == 1)
        freq = ieee80211_channel_to_frequency(elems->ds_params[0],
                              rx_status->band);
    else
        freq = rx_status->freq;

    channel = ieee80211_get_channel(local->hw.wiphy, freq);

    if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
        return;

    bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
                    channel, beacon);
    if (bss)
        ieee80211_rx_bss_put(local, bss);

    if (!sdata->u.mgd.associated)
        return;

    if (need_ps) {
        mutex_lock(&local->iflist_mtx);
        ieee80211_recalc_ps(local, -1);
        mutex_unlock(&local->iflist_mtx);
    }

    if (elems->ch_switch_ie &&
        memcmp(mgmt->bssid, sdata->u.mgd.associated->bssid, ETH_ALEN) == 0)
        ieee80211_sta_process_chanswitch(sdata, elems->ch_switch_ie,
                         bss, rx_status->mactime);
}


static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
                     struct sk_buff *skb)
{
    struct ieee80211_mgmt *mgmt = (void *)skb->data;
    struct ieee80211_if_managed *ifmgd;
    struct ieee80211_rx_status *rx_status = (void *) skb->cb;
    size_t baselen, len = skb->len;
    struct ieee802_11_elems elems;

    ifmgd = &sdata->u.mgd;

    ASSERT_MGD_MTX(ifmgd);

    if (!ether_addr_equal(mgmt->da, sdata->vif.addr))
        return; /* ignore ProbeResp to foreign address */

    baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
    if (baselen > len)
        return;

    ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
                &elems);

    ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);

    if (ifmgd->associated &&
        ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid))
        ieee80211_reset_ap_probe(sdata);

    if (ifmgd->auth_data && !ifmgd->auth_data->bss->proberesp_ies &&
        ether_addr_equal(mgmt->bssid, ifmgd->auth_data->bss->bssid)) {
        /* got probe response, continue with auth */
        sdata_info(sdata, "direct probe responded\n");
        ifmgd->auth_data->tries = 0;
        ifmgd->auth_data->timeout = jiffies;
        run_again(ifmgd, ifmgd->auth_data->timeout);
    }
}

/*
 * This is the canonical list of information elements we care about,
 * the filter code also gives us all changes to the Microsoft OUI
 * (00:50:F2) vendor IE which is used for WMM which we need to track.
 *
 * We implement beacon filtering in software since that means we can
 * avoid processing the frame here and in cfg80211, and userspace
 * will not be able to tell whether the hardware supports it or not.
 *
 * XXX: This list needs to be dynamic -- userspace needs to be able to
 *  add items it requires. It also needs to be able to tell us to
 *  look out for other vendor IEs.
 */
static const u64 care_about_ies =
    (1ULL << WLAN_EID_COUNTRY) |
    (1ULL << WLAN_EID_ERP_INFO) |
    (1ULL << WLAN_EID_CHANNEL_SWITCH) |
    (1ULL << WLAN_EID_PWR_CONSTRAINT) |
    (1ULL << WLAN_EID_HT_CAPABILITY) |
    (1ULL << WLAN_EID_HT_OPERATION);

static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                     struct ieee80211_mgmt *mgmt,
                     size_t len,
                     struct ieee80211_rx_status *rx_status)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
    size_t baselen;
    struct ieee802_11_elems elems;
    struct ieee80211_local *local = sdata->local;
    u32 changed = 0;
    bool erp_valid, directed_tim = false;
    u8 erp_value = 0;
    u32 ncrc;
    u8 *bssid;

    lockdep_assert_held(&ifmgd->mtx);

    /* Process beacon from the current BSS */
    baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
    if (baselen > len)
        return;

    if (rx_status->freq != local->oper_channel->center_freq)
        return;

    if (ifmgd->assoc_data && !ifmgd->assoc_data->have_beacon &&
        ether_addr_equal(mgmt->bssid, ifmgd->assoc_data->bss->bssid)) {
        ieee802_11_parse_elems(mgmt->u.beacon.variable,
                       len - baselen, &elems);

        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems,
                      false);
        ifmgd->assoc_data->have_beacon = true;
        ifmgd->assoc_data->sent_assoc = false;
        /* continue assoc process */
        ifmgd->assoc_data->timeout = jiffies;
        run_again(ifmgd, ifmgd->assoc_data->timeout);
        return;
    }

    if (!ifmgd->associated ||
        !ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid))
        return;
    bssid = ifmgd->associated->bssid;

    /* Track average RSSI from the Beacon frames of the current AP */
    ifmgd->last_beacon_signal = rx_status->signal;
    if (ifmgd->flags & IEEE80211_STA_RESET_SIGNAL_AVE) {
        ifmgd->flags &= ~IEEE80211_STA_RESET_SIGNAL_AVE;
        ifmgd->ave_beacon_signal = rx_status->signal * 16;
        ifmgd->last_cqm_event_signal = 0;
        ifmgd->count_beacon_signal = 1;
        ifmgd->last_ave_beacon_signal = 0;
    } else {
        ifmgd->ave_beacon_signal =
            (IEEE80211_SIGNAL_AVE_WEIGHT * rx_status->signal * 16 +
             (16 - IEEE80211_SIGNAL_AVE_WEIGHT) *
             ifmgd->ave_beacon_signal) / 16;
        ifmgd->count_beacon_signal++;
    }

    if (ifmgd->rssi_min_thold != ifmgd->rssi_max_thold &&
        ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT) {
        int sig = ifmgd->ave_beacon_signal;
        int last_sig = ifmgd->last_ave_beacon_signal;

        /*
         * if signal crosses either of the boundaries, invoke callback
         * with appropriate parameters
         */
        if (sig > ifmgd->rssi_max_thold &&
            (last_sig <= ifmgd->rssi_min_thold || last_sig == 0)) {
            ifmgd->last_ave_beacon_signal = sig;
            drv_rssi_callback(local, RSSI_EVENT_HIGH);
        } else if (sig < ifmgd->rssi_min_thold &&
               (last_sig >= ifmgd->rssi_max_thold ||
               last_sig == 0)) {
            ifmgd->last_ave_beacon_signal = sig;
            drv_rssi_callback(local, RSSI_EVENT_LOW);
        }
    }

    if (bss_conf->cqm_rssi_thold &&
        ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT &&
        !(sdata->vif.driver_flags & IEEE80211_VIF_SUPPORTS_CQM_RSSI)) {
        int sig = ifmgd->ave_beacon_signal / 16;
        int last_event = ifmgd->last_cqm_event_signal;
        int thold = bss_conf->cqm_rssi_thold;
        int hyst = bss_conf->cqm_rssi_hyst;
        if (sig < thold &&
            (last_event == 0 || sig < last_event - hyst)) {
            ifmgd->last_cqm_event_signal = sig;
            ieee80211_cqm_rssi_notify(
                &sdata->vif,
                NL80211_CQM_RSSI_THRESHOLD_EVENT_LOW,
                GFP_KERNEL);
        } else if (sig > thold &&
               (last_event == 0 || sig > last_event + hyst)) {
            ifmgd->last_cqm_event_signal = sig;
            ieee80211_cqm_rssi_notify(
                &sdata->vif,
                NL80211_CQM_RSSI_THRESHOLD_EVENT_HIGH,
                GFP_KERNEL);
        }
    }

    if (ifmgd->flags & IEEE80211_STA_BEACON_POLL) {
        mlme_dbg_ratelimited(sdata,
                     "cancelling probereq poll due to a received beacon\n");
        mutex_lock(&local->mtx);
        ifmgd->flags &= ~IEEE80211_STA_BEACON_POLL;
        ieee80211_run_deferred_scan(local);
        mutex_unlock(&local->mtx);

        mutex_lock(&local->iflist_mtx);
        ieee80211_recalc_ps(local, -1);
        mutex_unlock(&local->iflist_mtx);
    }

    /*
     * Push the beacon loss detection into the future since
     * we are processing a beacon from the AP just now.
     */
    ieee80211_sta_reset_beacon_monitor(sdata);

    ncrc = crc32_be(0, (void *)&mgmt->u.beacon.beacon_int, 4);
    ncrc = ieee802_11_parse_elems_crc(mgmt->u.beacon.variable,
                      len - baselen, &elems,
                      care_about_ies, ncrc);

    if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
        directed_tim = ieee80211_check_tim(elems.tim, elems.tim_len,
                           ifmgd->aid);

    if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) {
        if (directed_tim) {
            if (local->hw.conf.dynamic_ps_timeout > 0) {
                if (local->hw.conf.flags & IEEE80211_CONF_PS) {
                    local->hw.conf.flags &= ~IEEE80211_CONF_PS;
                    ieee80211_hw_config(local,
                                IEEE80211_CONF_CHANGE_PS);
                }
                ieee80211_send_nullfunc(local, sdata, 0);
            } else if (!local->pspolling && sdata->u.mgd.powersave) {
                local->pspolling = true;

                /*
                 * Here is assumed that the driver will be
                 * able to send ps-poll frame and receive a
                 * response even though power save mode is
                 * enabled, but some drivers might require
                 * to disable power save here. This needs
                 * to be investigated.
                 */
                ieee80211_send_pspoll(local, sdata);
            }
        }
    }

    if (ncrc == ifmgd->beacon_crc && ifmgd->beacon_crc_valid)
        return;
    ifmgd->beacon_crc = ncrc;
    ifmgd->beacon_crc_valid = true;

    ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems,
                  true);

    if (ieee80211_sta_wmm_params(local, sdata, elems.wmm_param,
                     elems.wmm_param_len))
        changed |= BSS_CHANGED_QOS;

    if (elems.erp_info && elems.erp_info_len >= 1) {
        erp_valid = true;
        erp_value = elems.erp_info[0];
    } else {
        erp_valid = false;
    }
    changed |= ieee80211_handle_bss_capability(sdata,
            le16_to_cpu(mgmt->u.beacon.capab_info),
            erp_valid, erp_value);


    if (elems.ht_cap_elem && elems.ht_operation && elems.wmm_param &&
        !(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {
        struct ieee80211_supported_band *sband;

        sband = local->hw.wiphy->bands[local->oper_channel->band];

        changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
                          bssid, true);
    }

    if (elems.country_elem && elems.pwr_constr_elem &&
        mgmt->u.probe_resp.capab_info &
                cpu_to_le16(WLAN_CAPABILITY_SPECTRUM_MGMT))
        ieee80211_handle_pwr_constr(sdata, local->oper_channel,
                        elems.country_elem,
                        elems.country_elem_len,
                        elems.pwr_constr_elem);

    ieee80211_bss_info_change_notify(sdata, changed);
}

void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
                  struct sk_buff *skb)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_rx_status *rx_status;
    struct ieee80211_mgmt *mgmt;
    struct cfg80211_bss *bss = NULL;
    enum rx_mgmt_action rma = RX_MGMT_NONE;
    u16 fc;

    rx_status = (struct ieee80211_rx_status *) skb->cb;
    mgmt = (struct ieee80211_mgmt *) skb->data;
    fc = le16_to_cpu(mgmt->frame_control);

    mutex_lock(&ifmgd->mtx);

    switch (fc & IEEE80211_FCTL_STYPE) {
    case IEEE80211_STYPE_BEACON:
        ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, rx_status);
        break;
    case IEEE80211_STYPE_PROBE_RESP:
        ieee80211_rx_mgmt_probe_resp(sdata, skb);
        break;
    case IEEE80211_STYPE_AUTH:
        rma = ieee80211_rx_mgmt_auth(sdata, mgmt, skb->len);
        break;
    case IEEE80211_STYPE_DEAUTH:
        rma = ieee80211_rx_mgmt_deauth(sdata, mgmt, skb->len);
        break;
    case IEEE80211_STYPE_DISASSOC:
        rma = ieee80211_rx_mgmt_disassoc(sdata, mgmt, skb->len);
        break;
    case IEEE80211_STYPE_ASSOC_RESP:
    case IEEE80211_STYPE_REASSOC_RESP:
        rma = ieee80211_rx_mgmt_assoc_resp(sdata, mgmt, skb->len, &bss);
        break;
    case IEEE80211_STYPE_ACTION:
        switch (mgmt->u.action.category) {
        case WLAN_CATEGORY_SPECTRUM_MGMT:
            ieee80211_sta_process_chanswitch(sdata,
                    &mgmt->u.action.u.chan_switch.sw_elem,
                    (void *)ifmgd->associated->priv,
                    rx_status->mactime);
            break;
        }
    }
    mutex_unlock(&ifmgd->mtx);

    switch (rma) {
    case RX_MGMT_NONE:
        /* no action */
        break;
    case RX_MGMT_CFG80211_DEAUTH:
        cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
        break;
    case RX_MGMT_CFG80211_DISASSOC:
        cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len);
        break;
    case RX_MGMT_CFG80211_RX_AUTH:
        cfg80211_send_rx_auth(sdata->dev, (u8 *)mgmt, skb->len);
        break;
    case RX_MGMT_CFG80211_RX_ASSOC:
        cfg80211_send_rx_assoc(sdata->dev, bss, (u8 *)mgmt, skb->len);
        break;
    case RX_MGMT_CFG80211_ASSOC_TIMEOUT:
        cfg80211_send_assoc_timeout(sdata->dev, mgmt->bssid);
        break;
    default:
        WARN(1, "unexpected: %d", rma);
    }
}

static void ieee80211_sta_timer(unsigned long data)
{
    struct ieee80211_sub_if_data *sdata =
        (struct ieee80211_sub_if_data *) data;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;

    if (local->quiescing) {
        set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);
        return;
    }

    ieee80211_queue_work(&local->hw, &sdata->work);
}

static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
                      u8 *bssid, u8 reason)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];

    ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH, reason,
                   false, frame_buf);
    mutex_unlock(&ifmgd->mtx);

    /*
     * must be outside lock due to cfg80211,
     * but that's not a problem.
     */
    cfg80211_send_deauth(sdata->dev, frame_buf, IEEE80211_DEAUTH_FRAME_LEN);

    mutex_lock(&local->mtx);
    ieee80211_recalc_idle(local);
    mutex_unlock(&local->mtx);

    mutex_lock(&ifmgd->mtx);
}

static int ieee80211_probe_auth(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_mgd_auth_data *auth_data = ifmgd->auth_data;

    lockdep_assert_held(&ifmgd->mtx);

    if (WARN_ON_ONCE(!auth_data))
        return -EINVAL;

    auth_data->tries++;

    if (auth_data->tries > IEEE80211_AUTH_MAX_TRIES) {
        sdata_info(sdata, "authentication with %pM timed out\n",
               auth_data->bss->bssid);

        /*
         * Most likely AP is not in the range so remove the
         * bss struct for that AP.
         */
        cfg80211_unlink_bss(local->hw.wiphy, auth_data->bss);

        return -ETIMEDOUT;
    }

    drv_mgd_prepare_tx(local, sdata);

    if (auth_data->bss->proberesp_ies) {
        sdata_info(sdata, "send auth to %pM (try %d/%d)\n",
               auth_data->bss->bssid, auth_data->tries,
               IEEE80211_AUTH_MAX_TRIES);

        auth_data->expected_transaction = 2;
        ieee80211_send_auth(sdata, 1, auth_data->algorithm,
                    auth_data->ie, auth_data->ie_len,
                    auth_data->bss->bssid,
                    auth_data->bss->bssid, NULL, 0, 0);
    } else {
        const u8 *ssidie;

        sdata_info(sdata, "direct probe to %pM (try %d/%i)\n",
               auth_data->bss->bssid, auth_data->tries,
               IEEE80211_AUTH_MAX_TRIES);

        ssidie = ieee80211_bss_get_ie(auth_data->bss, WLAN_EID_SSID);
        if (!ssidie)
            return -EINVAL;
        /*
         * Direct probe is sent to broadcast address as some APs
         * will not answer to direct packet in unassociated state.
         */
        ieee80211_send_probe_req(sdata, NULL, ssidie + 2, ssidie[1],
                     NULL, 0, (u32) -1, true, false,
                     auth_data->bss->channel);
    }

    auth_data->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
    run_again(ifmgd, auth_data->timeout);

    return 0;
}

static int ieee80211_do_assoc(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_mgd_assoc_data *assoc_data = sdata->u.mgd.assoc_data;
    struct ieee80211_local *local = sdata->local;

    lockdep_assert_held(&sdata->u.mgd.mtx);

    assoc_data->tries++;
    if (assoc_data->tries > IEEE80211_ASSOC_MAX_TRIES) {
        sdata_info(sdata, "association with %pM timed out\n",
               assoc_data->bss->bssid);

        /*
         * Most likely AP is not in the range so remove the
         * bss struct for that AP.
         */
        cfg80211_unlink_bss(local->hw.wiphy, assoc_data->bss);

        return -ETIMEDOUT;
    }

    sdata_info(sdata, "associate with %pM (try %d/%d)\n",
           assoc_data->bss->bssid, assoc_data->tries,
           IEEE80211_ASSOC_MAX_TRIES);
    ieee80211_send_assoc(sdata);

    assoc_data->timeout = jiffies + IEEE80211_ASSOC_TIMEOUT;
    run_again(&sdata->u.mgd, assoc_data->timeout);

    return 0;
}

void ieee80211_sta_work(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    mutex_lock(&ifmgd->mtx);

    if (ifmgd->auth_data &&
        time_after(jiffies, ifmgd->auth_data->timeout)) {
        if (ifmgd->auth_data->done) {
            /*
             * ok ... we waited for assoc but userspace didn't,
             * so let's just kill the auth data
             */
            ieee80211_destroy_auth_data(sdata, false);
        } else if (ieee80211_probe_auth(sdata)) {
            u8 bssid[ETH_ALEN];

            memcpy(bssid, ifmgd->auth_data->bss->bssid, ETH_ALEN);

            ieee80211_destroy_auth_data(sdata, false);

            mutex_unlock(&ifmgd->mtx);
            cfg80211_send_auth_timeout(sdata->dev, bssid);
            mutex_lock(&ifmgd->mtx);
        }
    } else if (ifmgd->auth_data)
        run_again(ifmgd, ifmgd->auth_data->timeout);

    if (ifmgd->assoc_data &&
        time_after(jiffies, ifmgd->assoc_data->timeout)) {
        if (!ifmgd->assoc_data->have_beacon ||
            ieee80211_do_assoc(sdata)) {
            u8 bssid[ETH_ALEN];

            memcpy(bssid, ifmgd->assoc_data->bss->bssid, ETH_ALEN);

            ieee80211_destroy_assoc_data(sdata, false);

            mutex_unlock(&ifmgd->mtx);
            cfg80211_send_assoc_timeout(sdata->dev, bssid);
            mutex_lock(&ifmgd->mtx);
        }
    } else if (ifmgd->assoc_data)
        run_again(ifmgd, ifmgd->assoc_data->timeout);

    if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                IEEE80211_STA_CONNECTION_POLL) &&
        ifmgd->associated) {
        u8 bssid[ETH_ALEN];
        int max_tries;

        memcpy(bssid, ifmgd->associated->bssid, ETH_ALEN);

        if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
            max_tries = max_nullfunc_tries;
        else
            max_tries = max_probe_tries;

        /* ACK received for nullfunc probing frame */
        if (!ifmgd->probe_send_count)
            ieee80211_reset_ap_probe(sdata);
        else if (ifmgd->nullfunc_failed) {
            if (ifmgd->probe_send_count < max_tries) {
                mlme_dbg(sdata,
                     "No ack for nullfunc frame to AP %pM, try %d/%i\n",
                     bssid, ifmgd->probe_send_count,
                     max_tries);
                ieee80211_mgd_probe_ap_send(sdata);
            } else {
                mlme_dbg(sdata,
                     "No ack for nullfunc frame to AP %pM, disconnecting.\n",
                     bssid);
                ieee80211_sta_connection_lost(sdata, bssid,
                    WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
            }
        } else if (time_is_after_jiffies(ifmgd->probe_timeout))
            run_again(ifmgd, ifmgd->probe_timeout);
        else if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
            mlme_dbg(sdata,
                 "Failed to send nullfunc to AP %pM after %dms, disconnecting\n",
                 bssid, probe_wait_ms);
            ieee80211_sta_connection_lost(sdata, bssid,
                WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
        } else if (ifmgd->probe_send_count < max_tries) {
            mlme_dbg(sdata,
                 "No probe response from AP %pM after %dms, try %d/%i\n",
                 bssid, probe_wait_ms,
                 ifmgd->probe_send_count, max_tries);
            ieee80211_mgd_probe_ap_send(sdata);
        } else {
            /*
             * We actually lost the connection ... or did we?
             * Let's make sure!
             */
            wiphy_debug(local->hw.wiphy,
                    "%s: No probe response from AP %pM"
                    " after %dms, disconnecting.\n",
                    sdata->name,
                    bssid, probe_wait_ms);

            ieee80211_sta_connection_lost(sdata, bssid,
                WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
        }
    }

    mutex_unlock(&ifmgd->mtx);

    mutex_lock(&local->mtx);
    ieee80211_recalc_idle(local);
    mutex_unlock(&local->mtx);
}

static void ieee80211_sta_bcn_mon_timer(unsigned long data)
{
    struct ieee80211_sub_if_data *sdata =
        (struct ieee80211_sub_if_data *) data;
    struct ieee80211_local *local = sdata->local;

    if (local->quiescing)
        return;

    ieee80211_queue_work(&sdata->local->hw,
                 &sdata->u.mgd.beacon_connection_loss_work);
}

static void ieee80211_sta_conn_mon_timer(unsigned long data)
{
    struct ieee80211_sub_if_data *sdata =
        (struct ieee80211_sub_if_data *) data;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_local *local = sdata->local;

    if (local->quiescing)
        return;

    ieee80211_queue_work(&local->hw, &ifmgd->monitor_work);
}

static void ieee80211_sta_monitor_work(struct work_struct *work)
{
    struct ieee80211_sub_if_data *sdata =
        container_of(work, struct ieee80211_sub_if_data,
                 u.mgd.monitor_work);

    ieee80211_mgd_probe_ap(sdata, false);
}

static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
{
    u32 flags;

    if (sdata->vif.type == NL80211_IFTYPE_STATION) {
        __ieee80211_stop_poll(sdata);

        /* let's probe the connection once */
        flags = sdata->local->hw.flags;
        if (!(flags & IEEE80211_HW_CONNECTION_MONITOR))
            ieee80211_queue_work(&sdata->local->hw,
                         &sdata->u.mgd.monitor_work);
        /* and do all the other regular work too */
        ieee80211_queue_work(&sdata->local->hw, &sdata->work);
    }
}

#ifdef CONFIG_PM
void ieee80211_sta_quiesce(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    /*
     * we need to use atomic bitops for the running bits
     * only because both timers might fire at the same
     * time -- the code here is properly synchronised.
     */

    cancel_work_sync(&ifmgd->request_smps_work);

    cancel_work_sync(&ifmgd->monitor_work);
    cancel_work_sync(&ifmgd->beacon_connection_loss_work);
    cancel_work_sync(&ifmgd->csa_connection_drop_work);
    if (del_timer_sync(&ifmgd->timer))
        set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);

    cancel_work_sync(&ifmgd->chswitch_work);
    if (del_timer_sync(&ifmgd->chswitch_timer))
        set_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running);

    /* these will just be re-established on connection */
    del_timer_sync(&ifmgd->conn_mon_timer);
    del_timer_sync(&ifmgd->bcn_mon_timer);
}

void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    if (!ifmgd->associated)
        return;

    if (sdata->flags & IEEE80211_SDATA_DISCONNECT_RESUME) {
        sdata->flags &= ~IEEE80211_SDATA_DISCONNECT_RESUME;
        mutex_lock(&ifmgd->mtx);
        if (ifmgd->associated) {
            mlme_dbg(sdata,
                 "driver requested disconnect after resume\n");
            ieee80211_sta_connection_lost(sdata,
                ifmgd->associated->bssid,
                WLAN_REASON_UNSPECIFIED);
            mutex_unlock(&ifmgd->mtx);
            return;
        }
        mutex_unlock(&ifmgd->mtx);
    }

    if (test_and_clear_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running))
        add_timer(&ifmgd->timer);
    if (test_and_clear_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running))
        add_timer(&ifmgd->chswitch_timer);
    ieee80211_sta_reset_beacon_monitor(sdata);

    mutex_lock(&sdata->local->mtx);
    ieee80211_restart_sta_timer(sdata);
    mutex_unlock(&sdata->local->mtx);
}
#endif

/* interface setup */
void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd;

    ifmgd = &sdata->u.mgd;
    INIT_WORK(&ifmgd->monitor_work, ieee80211_sta_monitor_work);
    INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
    INIT_WORK(&ifmgd->beacon_connection_loss_work,
          ieee80211_beacon_connection_loss_work);
    INIT_WORK(&ifmgd->csa_connection_drop_work,
          ieee80211_csa_connection_drop_work);
    INIT_WORK(&ifmgd->request_smps_work, ieee80211_request_smps_work);
    setup_timer(&ifmgd->timer, ieee80211_sta_timer,
            (unsigned long) sdata);
    setup_timer(&ifmgd->bcn_mon_timer, ieee80211_sta_bcn_mon_timer,
            (unsigned long) sdata);
    setup_timer(&ifmgd->conn_mon_timer, ieee80211_sta_conn_mon_timer,
            (unsigned long) sdata);
    setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,
            (unsigned long) sdata);

    ifmgd->flags = 0;
    ifmgd->powersave = sdata->wdev.ps;
    ifmgd->uapsd_queues = IEEE80211_DEFAULT_UAPSD_QUEUES;
    ifmgd->uapsd_max_sp_len = IEEE80211_DEFAULT_MAX_SP_LEN;

    mutex_init(&ifmgd->mtx);

    if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS)
        ifmgd->req_smps = IEEE80211_SMPS_AUTOMATIC;
    else
        ifmgd->req_smps = IEEE80211_SMPS_OFF;
}

/* scan finished notification */
void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local)
{
    struct ieee80211_sub_if_data *sdata;

    /* Restart STA timers */
    rcu_read_lock();
    list_for_each_entry_rcu(sdata, &local->interfaces, list)
        ieee80211_restart_sta_timer(sdata);
    rcu_read_unlock();
}

int ieee80211_max_network_latency(struct notifier_block *nb,
                  unsigned long data, void *dummy)
{
    s32 latency_usec = (s32) data;
    struct ieee80211_local *local =
        container_of(nb, struct ieee80211_local,
                 network_latency_notifier);

    mutex_lock(&local->iflist_mtx);
    ieee80211_recalc_ps(local, latency_usec);
    mutex_unlock(&local->iflist_mtx);

    return 0;
}

static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
                  struct cfg80211_bss *cbss)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    int ht_cfreq;
    enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
    const u8 *ht_oper_ie;
    const struct ieee80211_ht_operation *ht_oper = NULL;
    struct ieee80211_supported_band *sband;

    sband = local->hw.wiphy->bands[cbss->channel->band];

    ifmgd->flags &= ~IEEE80211_STA_DISABLE_40MHZ;

    if (sband->ht_cap.ht_supported) {
        ht_oper_ie = cfg80211_find_ie(WLAN_EID_HT_OPERATION,
                          cbss->information_elements,
                          cbss->len_information_elements);
        if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
            ht_oper = (void *)(ht_oper_ie + 2);
    }

    if (ht_oper) {
        ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
                              cbss->channel->band);
        /* check that channel matches the right operating channel */
        if (cbss->channel->center_freq != ht_cfreq) {
            /*
             * It's possible that some APs are confused here;
             * Netgear WNDR3700 sometimes reports 4 higher than
             * the actual channel in association responses, but
             * since we look at probe response/beacon data here
             * it should be OK.
             */
            sdata_info(sdata,
                   "Wrong control channel: center-freq: %d ht-cfreq: %d ht->primary_chan: %d band: %d - Disabling HT\n",
                   cbss->channel->center_freq,
                   ht_cfreq, ht_oper->primary_chan,
                   cbss->channel->band);
            ht_oper = NULL;
        } else {
            channel_type = NL80211_CHAN_HT20;
        }
    }

    if (ht_oper && sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
        /*
         * cfg80211 already verified that the channel itself can
         * be used, but it didn't check that we can do the right
         * HT type, so do that here as well. If HT40 isn't allowed
         * on this channel, disable 40 MHz operation.
         */

        switch (ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
            if (cbss->channel->flags & IEEE80211_CHAN_NO_HT40PLUS)
                ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
            else
                channel_type = NL80211_CHAN_HT40PLUS;
            break;
        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
            if (cbss->channel->flags & IEEE80211_CHAN_NO_HT40MINUS)
                ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
            else
                channel_type = NL80211_CHAN_HT40MINUS;
            break;
        }
    }

    if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
        /* can only fail due to HT40+/- mismatch */
        channel_type = NL80211_CHAN_HT20;
        sdata_info(sdata,
               "disabling 40 MHz due to multi-vif mismatch\n");
        ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
        WARN_ON(!ieee80211_set_channel_type(local, sdata,
                            channel_type));
    }

    local->oper_channel = cbss->channel;
    ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

    return 0;
}

static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
                     struct cfg80211_bss *cbss, bool assoc)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_bss *bss = (void *)cbss->priv;
    struct sta_info *new_sta = NULL;
    bool have_sta = false;
    int err;

    if (WARN_ON(!ifmgd->auth_data && !ifmgd->assoc_data))
        return -EINVAL;

    if (assoc) {
        rcu_read_lock();
        have_sta = sta_info_get(sdata, cbss->bssid);
        rcu_read_unlock();
    }

    if (!have_sta) {
        new_sta = sta_info_alloc(sdata, cbss->bssid, GFP_KERNEL);
        if (!new_sta)
            return -ENOMEM;
    }

    mutex_lock(&local->mtx);
    ieee80211_recalc_idle(sdata->local);
    mutex_unlock(&local->mtx);

    if (new_sta) {
        u32 rates = 0, basic_rates = 0;
        bool have_higher_than_11mbit;
        int min_rate = INT_MAX, min_rate_index = -1;
        struct ieee80211_supported_band *sband;

        sband = local->hw.wiphy->bands[cbss->channel->band];

        err = ieee80211_prep_channel(sdata, cbss);
        if (err) {
            sta_info_free(local, new_sta);
            return err;
        }

        ieee80211_get_rates(sband, bss->supp_rates,
                    bss->supp_rates_len,
                    &rates, &basic_rates,
                    &have_higher_than_11mbit,
                    &min_rate, &min_rate_index);

        /*
         * This used to be a workaround for basic rates missing
         * in the association response frame. Now that we no
         * longer use the basic rates from there, it probably
         * doesn't happen any more, but keep the workaround so
         * in case some *other* APs are buggy in different ways
         * we can connect -- with a warning.
         */
        if (!basic_rates && min_rate_index >= 0) {
            sdata_info(sdata,
                   "No basic rates, using min rate instead\n");
            basic_rates = BIT(min_rate_index);
        }

        new_sta->sta.supp_rates[cbss->channel->band] = rates;
        sdata->vif.bss_conf.basic_rates = basic_rates;

        /* cf. IEEE 802.11 9.2.12 */
        if (local->oper_channel->band == IEEE80211_BAND_2GHZ &&
            have_higher_than_11mbit)
            sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
        else
            sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;

        memcpy(ifmgd->bssid, cbss->bssid, ETH_ALEN);

        /* set timing information */
        sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
        sdata->vif.bss_conf.sync_tsf = cbss->tsf;
        sdata->vif.bss_conf.sync_device_ts = bss->device_ts;

        /* tell driver about BSSID, basic rates and timing */
        ieee80211_bss_info_change_notify(sdata,
            BSS_CHANGED_BSSID | BSS_CHANGED_BASIC_RATES |
            BSS_CHANGED_BEACON_INT);

        if (assoc)
            sta_info_pre_move_state(new_sta, IEEE80211_STA_AUTH);

        err = sta_info_insert(new_sta);
        new_sta = NULL;
        if (err) {
            sdata_info(sdata,
                   "failed to insert STA entry for the AP (error %d)\n",
                   err);
            return err;
        }
    } else
        WARN_ON_ONCE(!ether_addr_equal(ifmgd->bssid, cbss->bssid));

    return 0;
}

/* config hooks */
int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
               struct cfg80211_auth_request *req)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_mgd_auth_data *auth_data;
    u16 auth_alg;
    int err;

    /* prepare auth data structure */

    switch (req->auth_type) {
    case NL80211_AUTHTYPE_OPEN_SYSTEM:
        auth_alg = WLAN_AUTH_OPEN;
        break;
    case NL80211_AUTHTYPE_SHARED_KEY:
        if (IS_ERR(local->wep_tx_tfm))
            return -EOPNOTSUPP;
        auth_alg = WLAN_AUTH_SHARED_KEY;
        break;
    case NL80211_AUTHTYPE_FT:
        auth_alg = WLAN_AUTH_FT;
        break;
    case NL80211_AUTHTYPE_NETWORK_EAP:
        auth_alg = WLAN_AUTH_LEAP;
        break;
    default:
        return -EOPNOTSUPP;
    }

    auth_data = kzalloc(sizeof(*auth_data) + req->ie_len, GFP_KERNEL);
    if (!auth_data)
        return -ENOMEM;

    auth_data->bss = req->bss;

    if (req->ie && req->ie_len) {
        memcpy(auth_data->ie, req->ie, req->ie_len);
        auth_data->ie_len = req->ie_len;
    }

    if (req->key && req->key_len) {
        auth_data->key_len = req->key_len;
        auth_data->key_idx = req->key_idx;
        memcpy(auth_data->key, req->key, req->key_len);
    }

    auth_data->algorithm = auth_alg;

    /* try to authenticate/probe */

    mutex_lock(&ifmgd->mtx);

    if ((ifmgd->auth_data && !ifmgd->auth_data->done) ||
        ifmgd->assoc_data) {
        err = -EBUSY;
        goto err_free;
    }

    if (ifmgd->auth_data)
        ieee80211_destroy_auth_data(sdata, false);

    /* prep auth_data so we don't go into idle on disassoc */
    ifmgd->auth_data = auth_data;

    if (ifmgd->associated)
        ieee80211_set_disassoc(sdata, 0, 0, false, NULL);

    sdata_info(sdata, "authenticate with %pM\n", req->bss->bssid);

    err = ieee80211_prep_connection(sdata, req->bss, false);
    if (err)
        goto err_clear;

    err = ieee80211_probe_auth(sdata);
    if (err) {
        sta_info_destroy_addr(sdata, req->bss->bssid);
        goto err_clear;
    }

    /* hold our own reference */
    cfg80211_ref_bss(auth_data->bss);
    err = 0;
    goto out_unlock;

 err_clear:
    memset(ifmgd->bssid, 0, ETH_ALEN);
    ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
    ifmgd->auth_data = NULL;
 err_free:
    kfree(auth_data);
 out_unlock:
    mutex_unlock(&ifmgd->mtx);

    return err;
}

int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
            struct cfg80211_assoc_request *req)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    struct ieee80211_bss *bss = (void *)req->bss->priv;
    struct ieee80211_mgd_assoc_data *assoc_data;
    struct ieee80211_supported_band *sband;
    const u8 *ssidie, *ht_ie;
    int i, err;

    ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
    if (!ssidie)
        return -EINVAL;

    assoc_data = kzalloc(sizeof(*assoc_data) + req->ie_len, GFP_KERNEL);
    if (!assoc_data)
        return -ENOMEM;

    mutex_lock(&ifmgd->mtx);

    if (ifmgd->associated)
        ieee80211_set_disassoc(sdata, 0, 0, false, NULL);

    if (ifmgd->auth_data && !ifmgd->auth_data->done) {
        err = -EBUSY;
        goto err_free;
    }

    if (ifmgd->assoc_data) {
        err = -EBUSY;
        goto err_free;
    }

    if (ifmgd->auth_data) {
        bool match;

        /* keep sta info, bssid if matching */
        match = ether_addr_equal(ifmgd->bssid, req->bss->bssid);
        ieee80211_destroy_auth_data(sdata, match);
    }

    /* prepare assoc data */
    
    /*
     * keep only the 40 MHz disable bit set as it might have
     * been set during authentication already, all other bits
     * should be reset for a new connection
     */
    ifmgd->flags &= IEEE80211_STA_DISABLE_40MHZ;

    ifmgd->beacon_crc_valid = false;

    /*
     * IEEE802.11n does not allow TKIP/WEP as pairwise ciphers in HT mode.
     * We still associate in non-HT mode (11a/b/g) if any one of these
     * ciphers is configured as pairwise.
     * We can set this to true for non-11n hardware, that'll be checked
     * separately along with the peer capabilities.
     */
    for (i = 0; i < req->crypto.n_ciphers_pairwise; i++) {
        if (req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_WEP40 ||
            req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_TKIP ||
            req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_WEP104) {
            ifmgd->flags |= IEEE80211_STA_DISABLE_11N;
            ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
            netdev_info(sdata->dev,
                    "disabling HT/VHT due to WEP/TKIP use\n");
        }
    }

    if (req->flags & ASSOC_REQ_DISABLE_HT) {
        ifmgd->flags |= IEEE80211_STA_DISABLE_11N;
        ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
    }

    /* Also disable HT if we don't support it or the AP doesn't use WMM */
    sband = local->hw.wiphy->bands[req->bss->channel->band];
    if (!sband->ht_cap.ht_supported ||
        local->hw.queues < IEEE80211_NUM_ACS || !bss->wmm_used) {
        ifmgd->flags |= IEEE80211_STA_DISABLE_11N;
        if (!bss->wmm_used)
            netdev_info(sdata->dev,
                    "disabling HT as WMM/QoS is not supported by the AP\n");
    }

    /* disable VHT if we don't support it or the AP doesn't use WMM */
    if (!sband->vht_cap.vht_supported ||
        local->hw.queues < IEEE80211_NUM_ACS || !bss->wmm_used) {
        ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
        if (!bss->wmm_used)
            netdev_info(sdata->dev,
                    "disabling VHT as WMM/QoS is not supported by the AP\n");
    }

    memcpy(&ifmgd->ht_capa, &req->ht_capa, sizeof(ifmgd->ht_capa));
    memcpy(&ifmgd->ht_capa_mask, &req->ht_capa_mask,
           sizeof(ifmgd->ht_capa_mask));

    if (req->ie && req->ie_len) {
        memcpy(assoc_data->ie, req->ie, req->ie_len);
        assoc_data->ie_len = req->ie_len;
    }

    assoc_data->bss = req->bss;

    if (ifmgd->req_smps == IEEE80211_SMPS_AUTOMATIC) {
        if (ifmgd->powersave)
            ifmgd->ap_smps = IEEE80211_SMPS_DYNAMIC;
        else
            ifmgd->ap_smps = IEEE80211_SMPS_OFF;
    } else
        ifmgd->ap_smps = ifmgd->req_smps;

    assoc_data->capability = req->bss->capability;
    assoc_data->wmm = bss->wmm_used &&
              (local->hw.queues >= IEEE80211_NUM_ACS);
    assoc_data->supp_rates = bss->supp_rates;
    assoc_data->supp_rates_len = bss->supp_rates_len;

    ht_ie = ieee80211_bss_get_ie(req->bss, WLAN_EID_HT_OPERATION);
    if (ht_ie && ht_ie[1] >= sizeof(struct ieee80211_ht_operation))
        assoc_data->ap_ht_param =
            ((struct ieee80211_ht_operation *)(ht_ie + 2))->ht_param;
    else
        ifmgd->flags |= IEEE80211_STA_DISABLE_11N;

    if (bss->wmm_used && bss->uapsd_supported &&
        (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_UAPSD)) {
        assoc_data->uapsd = true;
        ifmgd->flags |= IEEE80211_STA_UAPSD_ENABLED;
    } else {
        assoc_data->uapsd = false;
        ifmgd->flags &= ~IEEE80211_STA_UAPSD_ENABLED;
    }

    memcpy(assoc_data->ssid, ssidie + 2, ssidie[1]);
    assoc_data->ssid_len = ssidie[1];

    if (req->prev_bssid)
        memcpy(assoc_data->prev_bssid, req->prev_bssid, ETH_ALEN);

    if (req->use_mfp) {
        ifmgd->mfp = IEEE80211_MFP_REQUIRED;
        ifmgd->flags |= IEEE80211_STA_MFP_ENABLED;
    } else {
        ifmgd->mfp = IEEE80211_MFP_DISABLED;
        ifmgd->flags &= ~IEEE80211_STA_MFP_ENABLED;
    }

    if (req->crypto.control_port)
        ifmgd->flags |= IEEE80211_STA_CONTROL_PORT;
    else
        ifmgd->flags &= ~IEEE80211_STA_CONTROL_PORT;

    sdata->control_port_protocol = req->crypto.control_port_ethertype;
    sdata->control_port_no_encrypt = req->crypto.control_port_no_encrypt;

    /* kick off associate process */

    ifmgd->assoc_data = assoc_data;

    err = ieee80211_prep_connection(sdata, req->bss, true);
    if (err)
        goto err_clear;

    if (!bss->dtim_period &&
        sdata->local->hw.flags & IEEE80211_HW_NEED_DTIM_PERIOD) {
        /*
         * Wait up to one beacon interval ...
         * should this be more if we miss one?
         */
        sdata_info(sdata, "waiting for beacon from %pM\n",
               ifmgd->bssid);
        assoc_data->timeout = TU_TO_EXP_TIME(req->bss->beacon_interval);
    } else {
        assoc_data->have_beacon = true;
        assoc_data->sent_assoc = false;
        assoc_data->timeout = jiffies;
    }
    run_again(ifmgd, assoc_data->timeout);

    if (bss->corrupt_data) {
        char *corrupt_type = "data";
        if (bss->corrupt_data & IEEE80211_BSS_CORRUPT_BEACON) {
            if (bss->corrupt_data &
                    IEEE80211_BSS_CORRUPT_PROBE_RESP)
                corrupt_type = "beacon and probe response";
            else
                corrupt_type = "beacon";
        } else if (bss->corrupt_data & IEEE80211_BSS_CORRUPT_PROBE_RESP)
            corrupt_type = "probe response";
        sdata_info(sdata, "associating with AP with corrupt %s\n",
               corrupt_type);
    }

    err = 0;
    goto out;
 err_clear:
    memset(ifmgd->bssid, 0, ETH_ALEN);
    ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
    ifmgd->assoc_data = NULL;
 err_free:
    kfree(assoc_data);
 out:
    mutex_unlock(&ifmgd->mtx);

    return err;
}

int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
             struct cfg80211_deauth_request *req)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
    bool tx = !req->local_state_change;

    mutex_lock(&ifmgd->mtx);

    if (ifmgd->auth_data) {
        ieee80211_destroy_auth_data(sdata, false);
        mutex_unlock(&ifmgd->mtx);
        return 0;
    }

    sdata_info(sdata,
           "deauthenticating from %pM by local choice (reason=%d)\n",
           req->bssid, req->reason_code);

    if (ifmgd->associated &&
        ether_addr_equal(ifmgd->associated->bssid, req->bssid)) {
        ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
                       req->reason_code, tx, frame_buf);
    } else {
        drv_mgd_prepare_tx(sdata->local, sdata);
        ieee80211_send_deauth_disassoc(sdata, req->bssid,
                           IEEE80211_STYPE_DEAUTH,
                           req->reason_code, tx,
                           frame_buf);
    }

    mutex_unlock(&ifmgd->mtx);

    __cfg80211_send_deauth(sdata->dev, frame_buf,
                   IEEE80211_DEAUTH_FRAME_LEN);

    mutex_lock(&sdata->local->mtx);
    ieee80211_recalc_idle(sdata->local);
    mutex_unlock(&sdata->local->mtx);

    return 0;
}

int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
               struct cfg80211_disassoc_request *req)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
    u8 bssid[ETH_ALEN];
    u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];

    mutex_lock(&ifmgd->mtx);

    /*
     * cfg80211 should catch this ... but it's racy since
     * we can receive a disassoc frame, process it, hand it
     * to cfg80211 while that's in a locked section already
     * trying to tell us that the user wants to disconnect.
     */
    if (ifmgd->associated != req->bss) {
        mutex_unlock(&ifmgd->mtx);
        return -ENOLINK;
    }

    sdata_info(sdata,
           "disassociating from %pM by local choice (reason=%d)\n",
           req->bss->bssid, req->reason_code);

    memcpy(bssid, req->bss->bssid, ETH_ALEN);
    ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DISASSOC,
                   req->reason_code, !req->local_state_change,
                   frame_buf);
    mutex_unlock(&ifmgd->mtx);

    __cfg80211_send_disassoc(sdata->dev, frame_buf,
                 IEEE80211_DEAUTH_FRAME_LEN);

    mutex_lock(&sdata->local->mtx);
    ieee80211_recalc_idle(sdata->local);
    mutex_unlock(&sdata->local->mtx);

    return 0;
}

void ieee80211_mgd_stop(struct ieee80211_sub_if_data *sdata)
{
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    mutex_lock(&ifmgd->mtx);
    if (ifmgd->assoc_data)
        ieee80211_destroy_assoc_data(sdata, false);
    if (ifmgd->auth_data)
        ieee80211_destroy_auth_data(sdata, false);
    del_timer_sync(&ifmgd->timer);
    mutex_unlock(&ifmgd->mtx);
}

void ieee80211_cqm_rssi_notify(struct ieee80211_vif *vif,
                   enum nl80211_cqm_rssi_threshold_event rssi_event,
                   gfp_t gfp)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

    trace_api_cqm_rssi_notify(sdata, rssi_event);

    cfg80211_cqm_rssi_notify(sdata->dev, rssi_event, gfp);
}
EXPORT_SYMBOL(ieee80211_cqm_rssi_notify);