mlme.c

Go to the documentation of this file.

/*
 * BSS client mode implementation
 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 *
 * 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"

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,
};

/* 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->local->hw.flags & IEEE80211_HW_BEACON_FILTER)
                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;
}

/*
 * ieee80211_enable_ht should be called only after the operating band
 * has been determined as ht configuration depends on the hw's
 * HT abilities for a specific band.
 */
static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
                               struct ieee80211_ht_info *hti,
                               const u8 *bssid, u16 ap_ht_cap_flags,
                               bool beacon_htcap_ie)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        struct sta_info *sta;
        u32 changed = 0;
        int hti_cfreq;
        u16 ht_opmode;
        bool enable_ht = true;
        enum nl80211_channel_type prev_chantype;
        enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;

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

        prev_chantype = sdata->vif.bss_conf.channel_type;

        /* HT is not supported */
        if (!sband->ht_cap.ht_supported)
                enable_ht = false;

        if (enable_ht) {
                hti_cfreq = ieee80211_channel_to_frequency(hti->control_chan,
                                                           sband->band);
                /* check that channel matches the right operating channel */
                if (local->hw.conf.channel->center_freq != hti_cfreq) {
                        /* Some APs mess this up, evidently.
                         * Netgear WNDR3700 sometimes reports 4 higher than
                         * the actual channel, for instance.
                         */
                        printk(KERN_DEBUG
                               "%s: Wrong control channel in association"
                               " response: configured center-freq: %d"
                               " hti-cfreq: %d  hti->control_chan: %d"
                               " band: %d.  Disabling HT.\n",
                               sdata->name,
                               local->hw.conf.channel->center_freq,
                               hti_cfreq, hti->control_chan,
                               sband->band);
                        enable_ht = false;
                }
        }

        if (enable_ht) {
                channel_type = NL80211_CHAN_HT20;

                if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
                    (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
                    (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
                        switch(hti->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
                        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
                                if (!(local->hw.conf.channel->flags &
                                    IEEE80211_CHAN_NO_HT40PLUS))
                                        channel_type = NL80211_CHAN_HT40PLUS;
                                break;
                        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
                                if (!(local->hw.conf.channel->flags &
                                    IEEE80211_CHAN_NO_HT40MINUS))
                                        channel_type = NL80211_CHAN_HT40MINUS;
                                break;
                        }
                }
        }

        if (local->tmp_channel)
                local->tmp_channel_type = channel_type;

        if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
                /* can only fail due to HT40+/- mismatch */
                channel_type = NL80211_CHAN_HT20;
                WARN_ON(!ieee80211_set_channel_type(local, sdata, channel_type));
        }

        if (beacon_htcap_ie && (prev_chantype != channel_type)) {
                /*
                 * Whenever the AP announces the HT mode change that can be
                 * 40MHz intolerant or etc., it would be safer to stop tx
                 * queues before doing hw config to avoid buffer overflow.
                 */
                ieee80211_stop_queues_by_reason(&sdata->local->hw,
                                IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);

                /* flush out all packets */
                synchronize_net();

                drv_flush(local, false);
        }

        /* channel_type change automatically detected */
        ieee80211_hw_config(local, 0);

        if (prev_chantype != channel_type) {
                rcu_read_lock();
                sta = sta_info_get(sdata, bssid);
                if (sta)
                        rate_control_rate_update(local, sband, sta,
                                                 IEEE80211_RC_HT_CHANGED,
                                                 channel_type);
                rcu_read_unlock();

                if (beacon_htcap_ie)
                        ieee80211_wake_queues_by_reason(&sdata->local->hw,
                                IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);
        }

        ht_opmode = le16_to_cpu(hti->operation_mode);

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

        return changed;
}

/* frame sending functions */

static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
                                           const u8 *bssid, u16 stype, u16 reason,
                                           void *cookie, bool send_frame)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;

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

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

        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
        memset(mgmt, 0, 24);
        memcpy(mgmt->da, bssid, ETH_ALEN);
        memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
        memcpy(mgmt->bssid, bssid, ETH_ALEN);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
        skb_put(skb, 2);
        /* u.deauth.reason_code == u.disassoc.reason_code */
        mgmt->u.deauth.reason_code = cpu_to_le16(reason);

        if (stype == IEEE80211_STYPE_DEAUTH)
                if (cookie)
                        __cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
                else
                        cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
        else
                if (cookie)
                        __cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len);
                else
                        cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len);
        if (!(ifmgd->flags & IEEE80211_STA_MFP_ENABLED))
                IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;

        if (send_frame)
                ieee80211_tx_skb(sdata, skb);
        else
                kfree_skb(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;

        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) {
                /*
                 * If the channel switch was not successful, stay
                 * around on the old channel. We currently lack
                 * good handling of this situation, possibly we
                 * should just drop the association.
                 */
                sdata->local->csa_channel = sdata->local->oper_channel;
        }

        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)
                return;

        sdata->local->csa_channel = new_ch;

        if (sdata->local->ops->channel_switch) {
                /* use driver's channel switch callback */
                struct ieee80211_channel_switch ch_switch;
                memset(&ch_switch, 0, sizeof(ch_switch));
                ch_switch.timestamp = timestamp;
                if (sw_elem->mode) {
                        ch_switch.block_tx = true;
                        ieee80211_stop_queues_by_reason(&sdata->local->hw,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);
                }
                ch_switch.channel = new_ch;
                ch_switch.count = sw_elem->count;
                ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
                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 {
                if (sw_elem->mode)
                        ieee80211_stop_queues_by_reason(&sdata->local->hw,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);
                ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
                mod_timer(&ifmgd->chswitch_timer,
                          jiffies +
                          msecs_to_jiffies(sw_elem->count *
                                           cbss->beacon_interval));
        }
}

static void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
                                        u16 capab_info, u8 *pwr_constr_elem,
                                        u8 pwr_constr_elem_len)
{
        struct ieee80211_conf *conf = &sdata->local->hw.conf;

        if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
                return;

        /* Power constraint IE length should be 1 octet */
        if (pwr_constr_elem_len != 1)
                return;

        if ((*pwr_constr_elem <= conf->channel->max_power) &&
            (*pwr_constr_elem != sdata->local->power_constr_level)) {
                sdata->local->power_constr_level = *pwr_constr_elem;
                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->associated->beacon_ies)
                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;
        }

        if (!list_empty(&local->work_list)) {
                local->ps_sdata = NULL;
                goto change;
        }

        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;
        }

 change:
        ieee80211_change_ps(local);
}

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 void 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;

        if (local->hw.queues < 4)
                return;

        if (!wmm_param)
                return;

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

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

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

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

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

        local->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)
                                local->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)
                                local->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)
                                local->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)
                                local->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;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                wiphy_debug(local->hw.wiphy,
                            "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);
#endif
                sdata->tx_conf[queue] = params;
                if (drv_conf_tx(local, sdata, queue, &params))
                        wiphy_debug(local->hw.wiphy,
                                    "failed to set TX queue parameters for queue %d\n",
                                    queue);
        }

        /* enable WMM or activate new settings */
        sdata->vif.bss_conf.qos = true;
        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_QOS);
}

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->hw.conf.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;
        /* set timing information */
        bss_conf->beacon_int = cbss->beacon_interval;
        bss_conf->timestamp = cbss->tsf;

        bss_info_changed |= BSS_CHANGED_BEACON_INT;
        bss_info_changed |= ieee80211_handle_bss_capability(sdata,
                cbss->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 */
        sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                                IEEE80211_STA_BEACON_POLL);

        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;
        /*
         * For now just always ask the driver to update the basic rateset
         * when we have associated, we aren't checking whether it actually
         * changed or not.
         */
        bss_info_changed |= BSS_CHANGED_BASIC_RATES;

        /* And the BSSID changed - we're associated now */
        bss_info_changed |= BSS_CHANGED_BSSID;

        /* Tell the driver to monitor connection quality (if supported) */
        if ((local->hw.flags & IEEE80211_HW_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);
        ieee80211_recalc_smps(local);
        mutex_unlock(&local->iflist_mtx);

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

static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
                                   bool remove_sta, bool tx)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;
        struct sta_info *sta;
        u32 changed = 0, config_changed = 0;
        u8 bssid[ETH_ALEN];

        ASSERT_MGD_MTX(ifmgd);

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

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

        ifmgd->associated = NULL;
        memset(ifmgd->bssid, 0, ETH_ALEN);

        /*
         * 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, bssid);
        if (sta) {
                set_sta_flag(sta, WLAN_STA_BLOCK_BA);
                ieee80211_sta_tear_down_BA_sessions(sta, tx);
        }
        mutex_unlock(&local->sta_mtx);

        changed |= ieee80211_reset_erp_info(sdata);

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

        ieee80211_set_wmm_default(sdata);

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

        /* on the next assoc, re-program HT parameters */
        sdata->ht_opmode_valid = false;

        local->power_constr_level = 0;

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

        if (local->hw.conf.flags & IEEE80211_CONF_PS) {
                local->hw.conf.flags &= ~IEEE80211_CONF_PS;
                config_changed |= IEEE80211_CONF_CHANGE_PS;
        }
        local->ps_sdata = NULL;

        ieee80211_hw_config(local, config_changed);

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

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

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

        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);
}

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;

        if (!(ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                              IEEE80211_STA_CONNECTION_POLL)))
            return;

        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                          IEEE80211_STA_BEACON_POLL);
        mutex_lock(&sdata->local->iflist_mtx);
        ieee80211_recalc_ps(sdata->local, -1);
        mutex_unlock(&sdata->local->iflist_mtx);

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

        /*
         * 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));
}

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.
         */
        if (sdata->local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
                ifmgd->nullfunc_failed = false;
                ieee80211_send_nullfunc(sdata->local, sdata, 0);
        } else {
                ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
                ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid[1], NULL, 0,
                                         (u32) -1, true, false);
        }

        ifmgd->probe_send_count++;
        ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
        run_again(ifmgd, ifmgd->probe_timeout);
}

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;

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

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

        mutex_lock(&ifmgd->mtx);

        if (!ifmgd->associated)
                goto out;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        if (beacon && net_ratelimit())
                printk(KERN_DEBUG "%s: detected beacon loss from AP "
                       "- sending probe request\n", sdata->name);
#endif

        /*
         * 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;

        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 sk_buff *skb;
        const u8 *ssid;

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

        ASSERT_MGD_MTX(ifmgd);

        if (!ifmgd->associated)
                return NULL;

        ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
        skb = ieee80211_build_probe_req(sdata, ifmgd->associated->bssid,
                                        (u32) -1, ssid + 2, ssid[1],
                                        NULL, 0, true);

        return skb;
}
EXPORT_SYMBOL(ieee80211_ap_probereq_get);

static void __ieee80211_connection_loss(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;
        u8 bssid[ETH_ALEN];

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

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

        printk(KERN_DEBUG "%s: Connection to AP %pM lost.\n",
               sdata->name, bssid);

        ieee80211_set_disassoc(sdata, true, true);
        mutex_unlock(&ifmgd->mtx);

        mutex_lock(&local->mtx);
        ieee80211_recalc_idle(local);
        mutex_unlock(&local->mtx);
        /*
         * must be outside lock due to cfg80211,
         * but that's not a problem.
         */
        ieee80211_send_deauth_disassoc(sdata, bssid,
                                       IEEE80211_STYPE_DEAUTH,
                                       WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
                                       NULL, true);
}

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);

        if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
                __ieee80211_connection_loss(sdata);
        else
                ieee80211_mgd_probe_ap(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 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;

        if (len < 24 + 2)
                return RX_MGMT_NONE;

        ASSERT_MGD_MTX(ifmgd);

        bssid = ifmgd->associated->bssid;

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

        printk(KERN_DEBUG "%s: deauthenticated from %pM (Reason: %u)\n",
                        sdata->name, bssid, reason_code);

        ieee80211_set_disassoc(sdata, true, false);
        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;

        if (len < 24 + 2)
                return RX_MGMT_NONE;

        ASSERT_MGD_MTX(ifmgd);

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

        if (WARN_ON(memcmp(ifmgd->associated->bssid, mgmt->sa, ETH_ALEN)))
                return RX_MGMT_NONE;

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

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

        ieee80211_set_disassoc(sdata, true, false);
        mutex_lock(&sdata->local->mtx);
        ieee80211_recalc_idle(sdata->local);
        mutex_unlock(&sdata->local->mtx);
        return RX_MGMT_CFG80211_DISASSOC;
}


static bool ieee80211_assoc_success(struct ieee80211_work *wk,
                                    struct ieee80211_mgmt *mgmt, size_t len)
{
        struct ieee80211_sub_if_data *sdata = wk->sdata;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        struct sta_info *sta;
        struct cfg80211_bss *cbss = wk->assoc.bss;
        u8 *pos;
        u32 rates, basic_rates;
        u16 capab_info, aid;
        struct ieee802_11_elems elems;
        struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
        u32 changed = 0;
        int i, j, err;
        bool have_higher_than_11mbit = false;
        u16 ap_ht_cap_flags;
        int min_rate = INT_MAX, min_rate_index = -1;

        /* 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)))
                printk(KERN_DEBUG
                       "%s: invalid AID value 0x%x; bits 15:14 not set\n",
                       sdata->name, aid);
        aid &= ~(BIT(15) | BIT(14));

        ifmgd->broken_ap = false;

        if (aid == 0 || aid > IEEE80211_MAX_AID) {
                printk(KERN_DEBUG
                       "%s: invalid AID value %d (out of range), turn off PS\n",
                       sdata->name, 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) {
                printk(KERN_DEBUG "%s: no SuppRates element in AssocResp\n",
                       sdata->name);
                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_rx(sdata, cbss->bssid);
        if (WARN_ON(!sta)) {
                mutex_unlock(&sdata->local->sta_mtx);
                return false;
        }

        set_sta_flag(sta, WLAN_STA_AUTH);
        set_sta_flag(sta, WLAN_STA_ASSOC);
        set_sta_flag(sta, WLAN_STA_ASSOC_AP);
        if (!(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
                set_sta_flag(sta, WLAN_STA_AUTHORIZED);

        rates = 0;
        basic_rates = 0;
        sband = local->hw.wiphy->bands[wk->chan->band];

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

                if (rate > 110)
                        have_higher_than_11mbit = true;

                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;
                        }
                }
        }

        for (i = 0; i < elems.ext_supp_rates_len; i++) {
                int rate = (elems.ext_supp_rates[i] & 0x7f) * 5;
                bool is_basic = !!(elems.ext_supp_rates[i] & 0x80);

                if (rate > 110)
                        have_higher_than_11mbit = true;

                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;
                        }
                }
        }

        /*
         * some buggy APs don't advertise basic_rates. use the lowest
         * supported rate instead.
         */
        if (unlikely(!basic_rates) && min_rate_index >= 0) {
                printk(KERN_DEBUG "%s: No basic rates in AssocResp. "
                       "Using min supported rate instead.\n", sdata->name);
                basic_rates = BIT(min_rate_index);
        }

        sta->sta.supp_rates[wk->chan->band] = rates;
        sdata->vif.bss_conf.basic_rates = basic_rates;

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

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

        ap_ht_cap_flags = sta->sta.ht_cap.cap;

        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);

        /* sta_info_reinsert will also unlock the mutex lock */
        err = sta_info_reinsert(sta);
        sta = NULL;
        if (err) {
                printk(KERN_DEBUG "%s: failed to insert STA entry for"
                       " the AP (error %d)\n", sdata->name, err);
                return false;
        }

        /*
         * 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);

        local->oper_channel = wk->chan;

        if (elems.ht_info_elem && elems.wmm_param &&
            (sdata->local->hw.queues >= 4) &&
            !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                changed |= ieee80211_enable_ht(sdata, elems.ht_info_elem,
                                               cbss->bssid, ap_ht_cap_flags,
                                               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 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) {
                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_elem && (elems->ch_switch_elem_len == 3) &&
            (memcmp(mgmt->bssid, sdata->u.mgd.associated->bssid,
                                                        ETH_ALEN) == 0)) {
                struct ieee80211_channel_sw_ie *sw_elem =
                        (struct ieee80211_channel_sw_ie *)elems->ch_switch_elem;
                ieee80211_sta_process_chanswitch(sdata, sw_elem,
                                                 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 (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
                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 &&
            memcmp(mgmt->bssid, ifmgd->associated->bssid, ETH_ALEN) == 0)
                ieee80211_reset_ap_probe(sdata);
}

/*
 * 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_INFORMATION);

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;

        ASSERT_MGD_MTX(ifmgd);

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

        if (rx_status->freq != local->hw.conf.channel->center_freq)
                return;

        /*
         * We might have received a number of frames, among them a
         * disassoc frame and a beacon...
         */
        if (!ifmgd->associated)
                return;

        bssid = ifmgd->associated->bssid;

        /*
         * And in theory even frames from a different AP we were just
         * associated to a split-second ago!
         */
        if (memcmp(bssid, mgmt->bssid, ETH_ALEN) != 0)
                return;

        /* 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 &&
            !(local->hw.flags & IEEE80211_HW_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) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                if (net_ratelimit()) {
                        printk(KERN_DEBUG "%s: cancelling probereq poll due "
                               "to a received beacon\n", sdata->name);
                }
#endif
                ifmgd->flags &= ~IEEE80211_STA_BEACON_POLL;
                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 (ncrc != ifmgd->beacon_crc || !ifmgd->beacon_crc_valid) {
                ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems,
                                      true);

                ieee80211_sta_wmm_params(local, sdata, elems.wmm_param,
                                         elems.wmm_param_len);
        }

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

        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_info_elem && elems.wmm_param &&
            !(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {
                struct sta_info *sta;
                struct ieee80211_supported_band *sband;
                u16 ap_ht_cap_flags;

                rcu_read_lock();

                sta = sta_info_get(sdata, bssid);
                if (WARN_ON(!sta)) {
                        rcu_read_unlock();
                        return;
                }

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

                ieee80211_ht_cap_ie_to_sta_ht_cap(sband,
                                elems.ht_cap_elem, &sta->sta.ht_cap);

                ap_ht_cap_flags = sta->sta.ht_cap.cap;

                rcu_read_unlock();

                changed |= ieee80211_enable_ht(sdata, elems.ht_info_elem,
                                               bssid, ap_ht_cap_flags, true);
        }

        /* Note: country IE parsing is done for us by cfg80211 */
        if (elems.country_elem) {
                /* TODO: IBSS also needs this */
                if (elems.pwr_constr_elem)
                        ieee80211_handle_pwr_constr(sdata,
                                le16_to_cpu(mgmt->u.probe_resp.capab_info),
                                elems.pwr_constr_elem,
                                elems.pwr_constr_elem_len);
        }

        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;
        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);

        if (ifmgd->associated &&
            memcmp(ifmgd->associated->bssid, mgmt->bssid, ETH_ALEN) == 0) {
                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_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_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;
                default:
                        WARN(1, "unexpected: %d", rma);
                }
                return;
        }

        mutex_unlock(&ifmgd->mtx);

        if (skb->len >= 24 + 2 /* mgmt + deauth reason */ &&
            (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DEAUTH) {
                struct ieee80211_local *local = sdata->local;
                struct ieee80211_work *wk;

                mutex_lock(&local->mtx);
                list_for_each_entry(wk, &local->work_list, list) {
                        if (wk->sdata != sdata)
                                continue;

                        if (wk->type != IEEE80211_WORK_ASSOC &&
                            wk->type != IEEE80211_WORK_ASSOC_BEACON_WAIT)
                                continue;

                        if (memcmp(mgmt->bssid, wk->filter_ta, ETH_ALEN))
                                continue;
                        if (memcmp(mgmt->sa, wk->filter_ta, ETH_ALEN))
                                continue;

                        /*
                         * Printing the message only here means we can't
                         * spuriously print it, but it also means that it
                         * won't be printed when the frame comes in before
                         * we even tried to associate or in similar cases.
                         *
                         * Ultimately, I suspect cfg80211 should print the
                         * messages instead.
                         */
                        printk(KERN_DEBUG
                               "%s: deauthenticated from %pM (Reason: %u)\n",
                               sdata->name, mgmt->bssid,
                               le16_to_cpu(mgmt->u.deauth.reason_code));

                        list_del_rcu(&wk->list);
                        free_work(wk);
                        break;
                }
                mutex_unlock(&local->mtx);

                cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
        }
}

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;

        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                          IEEE80211_STA_BEACON_POLL);

        ieee80211_set_disassoc(sdata, true, true);
        mutex_unlock(&ifmgd->mtx);
        mutex_lock(&local->mtx);
        ieee80211_recalc_idle(local);
        mutex_unlock(&local->mtx);
        /*
         * must be outside lock due to cfg80211,
         * but that's not a problem.
         */
        ieee80211_send_deauth_disassoc(sdata, bssid,
                        IEEE80211_STYPE_DEAUTH, reason,
                        NULL, true);
        mutex_lock(&ifmgd->mtx);
}

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

        /* then process the rest of the work */
        mutex_lock(&ifmgd->mtx);

        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) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                                wiphy_debug(local->hw.wiphy,
                                            "%s: No ack for nullfunc frame to"
                                            " AP %pM, try %d/%i\n",
                                            sdata->name, bssid,
                                            ifmgd->probe_send_count, max_tries);
#endif
                                ieee80211_mgd_probe_ap_send(sdata);
                        } else {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                                wiphy_debug(local->hw.wiphy,
                                            "%s: No ack for nullfunc frame to"
                                            " AP %pM, disconnecting.\n",
                                            sdata->name, bssid);
#endif
                                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) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                        wiphy_debug(local->hw.wiphy,
                                    "%s: Failed to send nullfunc to AP %pM"
                                    " after %dms, disconnecting.\n",
                                    sdata->name,
                                    bssid, probe_wait_ms);
#endif
                        ieee80211_sta_connection_lost(sdata, bssid,
                                WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
                } else if (ifmgd->probe_send_count < max_tries) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                        wiphy_debug(local->hw.wiphy,
                                    "%s: No probe response from AP %pM"
                                    " after %dms, try %d/%i\n",
                                    sdata->name,
                                    bssid, probe_wait_ms,
                                    ifmgd->probe_send_count, max_tries);
#endif
                        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);
}

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)
{
        if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                sdata->u.mgd.flags &= ~(IEEE80211_STA_BEACON_POLL |
                                        IEEE80211_STA_CONNECTION_POLL);

                /* let's probe the connection once */
                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);
        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) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                        wiphy_debug(sdata->local->hw.wiphy,
                                    "%s: driver requested disconnect after resume.\n",
                                    sdata->name);
#endif
                        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);
        ieee80211_restart_sta_timer(sdata);
        ieee80211_queue_work(&sdata->local->hw, &sdata->u.mgd.monitor_work);
}
#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->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;

        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 = local->scan_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;
}

/* config hooks */
static enum work_done_result
ieee80211_probe_auth_done(struct ieee80211_work *wk,
                          struct sk_buff *skb)
{
        struct ieee80211_local *local = wk->sdata->local;

        if (!skb) {
                cfg80211_send_auth_timeout(wk->sdata->dev, wk->filter_ta);
                goto destroy;
        }

        if (wk->type == IEEE80211_WORK_AUTH) {
                cfg80211_send_rx_auth(wk->sdata->dev, skb->data, skb->len);
                goto destroy;
        }

        mutex_lock(&wk->sdata->u.mgd.mtx);
        ieee80211_rx_mgmt_probe_resp(wk->sdata, skb);
        mutex_unlock(&wk->sdata->u.mgd.mtx);

        wk->type = IEEE80211_WORK_AUTH;
        wk->probe_auth.tries = 0;
        return WORK_DONE_REQUEUE;
 destroy:
        if (wk->probe_auth.synced)
                drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
                                   IEEE80211_TX_SYNC_AUTH);

        return WORK_DONE_DESTROY;
}

int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
                       struct cfg80211_auth_request *req)
{
        const u8 *ssid;
        struct ieee80211_work *wk;
        u16 auth_alg;

        if (req->local_state_change)
                return 0; /* no need to update mac80211 state */

        switch (req->auth_type) {
        case NL80211_AUTHTYPE_OPEN_SYSTEM:
                auth_alg = WLAN_AUTH_OPEN;
                break;
        case NL80211_AUTHTYPE_SHARED_KEY:
                if (IS_ERR(sdata->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;
        }

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

        memcpy(wk->filter_ta, req->bss->bssid, ETH_ALEN);

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

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

        ssid = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
        memcpy(wk->probe_auth.ssid, ssid + 2, ssid[1]);
        wk->probe_auth.ssid_len = ssid[1];

        wk->probe_auth.algorithm = auth_alg;
        wk->probe_auth.privacy = req->bss->capability & WLAN_CAPABILITY_PRIVACY;

        /* if we already have a probe, don't probe again */
        if (req->bss->proberesp_ies)
                wk->type = IEEE80211_WORK_AUTH;
        else
                wk->type = IEEE80211_WORK_DIRECT_PROBE;
        wk->chan = req->bss->channel;
        wk->chan_type = NL80211_CHAN_NO_HT;
        wk->sdata = sdata;
        wk->done = ieee80211_probe_auth_done;

        ieee80211_add_work(wk);
        return 0;
}

/* create and insert a dummy station entry */
static int ieee80211_pre_assoc(struct ieee80211_sub_if_data *sdata,
                                u8 *bssid) {
        struct sta_info *sta;
        int err;

        sta = sta_info_alloc(sdata, bssid, GFP_KERNEL);
        if (!sta)
                return -ENOMEM;

        sta->dummy = true;

        err = sta_info_insert(sta);
        sta = NULL;
        if (err) {
                printk(KERN_DEBUG "%s: failed to insert Dummy STA entry for"
                       " the AP (error %d)\n", sdata->name, err);
                return err;
        }

        return 0;
}

static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
                                                  struct sk_buff *skb)
{
        struct ieee80211_local *local = wk->sdata->local;
        struct ieee80211_mgmt *mgmt;
        struct ieee80211_rx_status *rx_status;
        struct ieee802_11_elems elems;
        struct cfg80211_bss *cbss = wk->assoc.bss;
        u16 status;

        if (!skb) {
                sta_info_destroy_addr(wk->sdata, cbss->bssid);
                cfg80211_send_assoc_timeout(wk->sdata->dev, wk->filter_ta);
                goto destroy;
        }

        if (wk->type == IEEE80211_WORK_ASSOC_BEACON_WAIT) {
                mutex_lock(&wk->sdata->u.mgd.mtx);
                rx_status = (void *) skb->cb;
                ieee802_11_parse_elems(skb->data + 24 + 12, skb->len - 24 - 12, &elems);
                ieee80211_rx_bss_info(wk->sdata, (void *)skb->data, skb->len, rx_status,
                                      &elems, true);
                mutex_unlock(&wk->sdata->u.mgd.mtx);

                wk->type = IEEE80211_WORK_ASSOC;
                /* not really done yet */
                return WORK_DONE_REQUEUE;
        }

        mgmt = (void *)skb->data;
        status = le16_to_cpu(mgmt->u.assoc_resp.status_code);

        if (status == WLAN_STATUS_SUCCESS) {
                if (wk->assoc.synced)
                        drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
                                           IEEE80211_TX_SYNC_ASSOC);

                mutex_lock(&wk->sdata->u.mgd.mtx);
                if (!ieee80211_assoc_success(wk, mgmt, skb->len)) {
                        mutex_unlock(&wk->sdata->u.mgd.mtx);
                        /* oops -- internal error -- send timeout for now */
                        sta_info_destroy_addr(wk->sdata, cbss->bssid);
                        cfg80211_send_assoc_timeout(wk->sdata->dev,
                                                    wk->filter_ta);
                        return WORK_DONE_DESTROY;
                }

                mutex_unlock(&wk->sdata->u.mgd.mtx);
        } else {
                /* assoc failed - destroy the dummy station entry */
                sta_info_destroy_addr(wk->sdata, cbss->bssid);
        }

        cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
 destroy:
        if (wk->assoc.synced)
                drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
                                   IEEE80211_TX_SYNC_ASSOC);

        return WORK_DONE_DESTROY;
}

int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
                        struct cfg80211_assoc_request *req)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_bss *bss = (void *)req->bss->priv;
        struct ieee80211_work *wk;
        const u8 *ssid;
        int i, err;

        mutex_lock(&ifmgd->mtx);
        if (ifmgd->associated) {
                if (!req->prev_bssid ||
                    memcmp(req->prev_bssid, ifmgd->associated->bssid,
                           ETH_ALEN)) {
                        /*
                         * We are already associated and the request was not a
                         * reassociation request from the current BSS, so
                         * reject it.
                         */
                        mutex_unlock(&ifmgd->mtx);
                        return -EALREADY;
                }

                /* Trying to reassociate - clear previous association state */
                ieee80211_set_disassoc(sdata, true, false);
        }
        mutex_unlock(&ifmgd->mtx);

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

        /*
         * create a dummy station info entry in order
         * to start accepting incoming EAPOL packets from the station
         */
        err = ieee80211_pre_assoc(sdata, req->bss->bssid);
        if (err) {
                kfree(wk);
                return err;
        }

        ifmgd->flags &= ~IEEE80211_STA_DISABLE_11N;
        ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;

        ifmgd->beacon_crc_valid = false;

        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;


        if (req->ie && req->ie_len) {
                memcpy(wk->ie, req->ie, req->ie_len);
                wk->ie_len = req->ie_len;
        } else
                wk->ie_len = 0;

        wk->assoc.bss = req->bss;

        memcpy(wk->filter_ta, req->bss->bssid, ETH_ALEN);

        /* new association always uses requested smps mode */
        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;

        wk->assoc.smps = ifmgd->ap_smps;
        /*
         * 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.
         */
        wk->assoc.use_11n = !(ifmgd->flags & IEEE80211_STA_DISABLE_11N);
        wk->assoc.capability = req->bss->capability;
        wk->assoc.wmm_used = bss->wmm_used;
        wk->assoc.supp_rates = bss->supp_rates;
        wk->assoc.supp_rates_len = bss->supp_rates_len;
        wk->assoc.ht_information_ie =
                ieee80211_bss_get_ie(req->bss, WLAN_EID_HT_INFORMATION);

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

        ssid = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
        memcpy(wk->assoc.ssid, ssid + 2, ssid[1]);
        wk->assoc.ssid_len = ssid[1];

        if (req->prev_bssid)
                memcpy(wk->assoc.prev_bssid, req->prev_bssid, ETH_ALEN);

        wk->chan = req->bss->channel;
        wk->chan_type = NL80211_CHAN_NO_HT;
        wk->sdata = sdata;
        wk->done = ieee80211_assoc_done;
        if (!bss->dtim_period &&
            sdata->local->hw.flags & IEEE80211_HW_NEED_DTIM_PERIOD)
                wk->type = IEEE80211_WORK_ASSOC_BEACON_WAIT;
        else
                wk->type = IEEE80211_WORK_ASSOC;

        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;

        ieee80211_add_work(wk);
        return 0;
}

int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
                         struct cfg80211_deauth_request *req,
                         void *cookie)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        u8 bssid[ETH_ALEN];
        bool assoc_bss = false;

        mutex_lock(&ifmgd->mtx);

        memcpy(bssid, req->bss->bssid, ETH_ALEN);
        if (ifmgd->associated == req->bss) {
                ieee80211_set_disassoc(sdata, false, true);
                mutex_unlock(&ifmgd->mtx);
                assoc_bss = true;
        } else {
                bool not_auth_yet = false;
                struct ieee80211_work *tmp, *wk = NULL;

                mutex_unlock(&ifmgd->mtx);

                mutex_lock(&local->mtx);
                list_for_each_entry(tmp, &local->work_list, list) {
                        if (tmp->sdata != sdata)
                                continue;

                        if (tmp->type != IEEE80211_WORK_DIRECT_PROBE &&
                            tmp->type != IEEE80211_WORK_AUTH &&
                            tmp->type != IEEE80211_WORK_ASSOC &&
                            tmp->type != IEEE80211_WORK_ASSOC_BEACON_WAIT)
                                continue;

                        if (memcmp(req->bss->bssid, tmp->filter_ta, ETH_ALEN))
                                continue;

                        not_auth_yet = tmp->type == IEEE80211_WORK_DIRECT_PROBE;
                        list_del_rcu(&tmp->list);
                        synchronize_rcu();
                        wk = tmp;
                        break;
                }
                mutex_unlock(&local->mtx);

                if (wk && wk->type == IEEE80211_WORK_ASSOC) {
                        /* clean up dummy sta & TX sync */
                        sta_info_destroy_addr(wk->sdata, wk->filter_ta);
                        if (wk->assoc.synced)
                                drv_finish_tx_sync(local, wk->sdata,
                                                   wk->filter_ta,
                                                   IEEE80211_TX_SYNC_ASSOC);
                } else if (wk && wk->type == IEEE80211_WORK_AUTH) {
                        if (wk->probe_auth.synced)
                                drv_finish_tx_sync(local, wk->sdata,
                                                   wk->filter_ta,
                                                   IEEE80211_TX_SYNC_AUTH);
                }
                kfree(wk);

                /*
                 * If somebody requests authentication and we haven't
                 * sent out an auth frame yet there's no need to send
                 * out a deauth frame either. If the state was PROBE,
                 * then this is the case. If it's AUTH we have sent a
                 * frame, and if it's IDLE we have completed the auth
                 * process already.
                 */
                if (not_auth_yet) {
                        __cfg80211_auth_canceled(sdata->dev, bssid);
                        return 0;
                }
        }

        printk(KERN_DEBUG "%s: deauthenticating from %pM by local choice (reason=%d)\n",
               sdata->name, bssid, req->reason_code);

        ieee80211_send_deauth_disassoc(sdata, bssid, IEEE80211_STYPE_DEAUTH,
                                       req->reason_code, cookie,
                                       !req->local_state_change);
        if (assoc_bss)
                sta_info_flush(sdata->local, sdata);

        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,
                           void *cookie)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        u8 bssid[ETH_ALEN];

        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;
        }

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

        memcpy(bssid, req->bss->bssid, ETH_ALEN);
        ieee80211_set_disassoc(sdata, false, true);

        mutex_unlock(&ifmgd->mtx);

        ieee80211_send_deauth_disassoc(sdata, req->bss->bssid,
                        IEEE80211_STYPE_DISASSOC, req->reason_code,
                        cookie, !req->local_state_change);
        sta_info_flush(sdata->local, sdata);

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

        return 0;
}

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);

unsigned char ieee80211_get_operstate(struct ieee80211_vif *vif)
{
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
        return sdata->dev->operstate;
}
EXPORT_SYMBOL(ieee80211_get_operstate);