mac80211: Add debug print on unexpect authentication state

[mirror_ubuntu-artful-kernel.git] / net / mac80211 / mlme.c

/*
 * 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"

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

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

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

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

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

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

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

#define TMR_RUNNING_TIMER       0
#define TMR_RUNNING_CHANSW      1

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        ifmgd->probe_send_count = 0;
}

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

static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
                                  struct ieee80211_ht_operation *ht_oper,
                                  const u8 *bssid, bool reconfig)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_channel *chan;
        struct sta_info *sta;
        u32 changed = 0;
        u16 ht_opmode;
        bool disable_40 = false;

        rcu_read_lock();
        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
        if (WARN_ON(!chanctx_conf)) {
                rcu_read_unlock();
                return 0;
        }
        chan = chanctx_conf->channel;
        rcu_read_unlock();
        sband = local->hw.wiphy->bands[chan->band];

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

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

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

        WARN_ON_ONCE(!sta);

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

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

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

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

        ht_opmode = le16_to_cpu(ht_oper->operation_mode);

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

        return changed;
}

/* frame sending functions */

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

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

        return count;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_mgd_assoc_data *assoc_data = ifmgd->assoc_data;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u8 *pos, qos_info;
        size_t offset = 0, noffset;
        int i, count, rates_len, supp_rates_len;
        u16 capab;
        struct ieee80211_supported_band *sband;
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_channel *chan;
        u32 rates = 0;

        lockdep_assert_held(&ifmgd->mtx);

        rcu_read_lock();
        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
        if (WARN_ON(!chanctx_conf)) {
                rcu_read_unlock();
                return;
        }
        chan = chanctx_conf->channel;
        rcu_read_unlock();
        sband = local->hw.wiphy->bands[chan->band];

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

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

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

        capab = WLAN_CAPABILITY_ESS;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
                                    sband, chan, sdata->smps_mode);

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

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

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

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

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

        drv_mgd_prepare_tx(local, sdata);

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

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

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

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

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

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

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

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

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

        ieee80211_tx_skb(sdata, skb);
}

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

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

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

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

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

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

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

        if (!ieee80211_sdata_running(sdata))
                return;

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

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

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

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

void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
{
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

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

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

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

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

void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                      struct ieee80211_channel_sw_ie *sw_elem,
                                      struct ieee80211_bss *bss,
                                      u64 timestamp)
{
        struct cfg80211_bss *cbss =
                container_of((void *)bss, struct cfg80211_bss, priv);
        struct ieee80211_channel *new_ch;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
                                                      cbss->channel->band);
        struct ieee80211_chanctx *chanctx;

        ASSERT_MGD_MTX(ifmgd);

        if (!ifmgd->associated)
                return;

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

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

        if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                return;

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

        ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;

        if (sdata->local->use_chanctx) {
                sdata_info(sdata,
                           "not handling channel switch with channel contexts\n");
                ieee80211_queue_work(&sdata->local->hw,
                                     &ifmgd->csa_connection_drop_work);
        }

        mutex_lock(&sdata->local->chanctx_mtx);
        if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
                mutex_unlock(&sdata->local->chanctx_mtx);
                return;
        }
        chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
                               struct ieee80211_chanctx, conf);
        if (chanctx->refcount > 1) {
                sdata_info(sdata,
                           "channel switch with multiple interfaces on the same channel, disconnecting\n");
                ieee80211_queue_work(&sdata->local->hw,
                                     &ifmgd->csa_connection_drop_work);
                mutex_unlock(&sdata->local->chanctx_mtx);
                return;
        }
        mutex_unlock(&sdata->local->chanctx_mtx);

        sdata->local->csa_channel = new_ch;

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

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

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

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

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

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

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

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

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

                if (first_channel >= IEEE80211_COUNTRY_EXTENSION_ID)
                        goto next;

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

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

        if (!have_chan_pwr)
                return;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        if (!mgd->powersave)
                return false;

        if (mgd->broken_ap)
                return false;

        if (!mgd->associated)
                return false;

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

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

        return authorized;
}

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

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

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

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

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

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

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

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

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

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

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

        ieee80211_change_ps(local);
}

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

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

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

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

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

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

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

        ifmgd = &sdata->u.mgd;

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

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

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

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

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

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

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

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

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

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

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

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

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

        if (!wmm_param)
                return false;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
        if (ieee80211_get_sdata_band(sdata) == IEEE80211_BAND_5GHZ)
                use_short_slot = true;

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

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

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

        return changed;
}

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

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

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

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

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

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

        ieee80211_led_assoc(local, 1);

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

        bss_conf->assoc = 1;

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

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

        ieee80211_bss_info_change_notify(sdata, bss_info_changed);

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

        ieee80211_recalc_smps(sdata);
        ieee80211_recalc_ps_vif(sdata);

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

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

        ASSERT_MGD_MTX(ifmgd);

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

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

        ieee80211_stop_poll(sdata);

        ifmgd->associated = NULL;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        local->ap_power_level = 0;

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

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

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

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

        ieee80211_vif_release_channel(sdata);

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

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

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

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

        ieee80211_sta_reset_conn_monitor(sdata);
}

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

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

        __ieee80211_stop_poll(sdata);

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

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

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

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

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

        if (ack)
                ieee80211_sta_reset_conn_monitor(sdata);

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

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

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

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

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

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

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

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

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

        if (!ieee80211_sdata_running(sdata))
                return;

        mutex_lock(&ifmgd->mtx);

        if (!ifmgd->associated)
                goto out;

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

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

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

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

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

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

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

        if (already)
                goto out;

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

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

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

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

        ASSERT_MGD_MTX(ifmgd);

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

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

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

        return skb;
}
EXPORT_SYMBOL(ieee80211_ap_probereq_get);

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

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

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

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

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

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

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

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

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

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

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

        trace_api_beacon_loss(sdata);

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

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

        trace_api_connection_loss(sdata);

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


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

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

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

                memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
                ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
                ieee80211_vif_release_channel(sdata);
        }

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

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

        pos = mgmt->u.auth.variable;
        ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);
        if (!elems.challenge)
                return;
        auth_data->expected_transaction = 4;
        drv_mgd_prepare_tx(sdata->local, sdata);
        ieee80211_send_auth(sdata, 3, auth_data->algorithm, 0,
                            elems.challenge - 2, elems.challenge_len + 2,
                            auth_data->bss->bssid, auth_data->bss->bssid,
                            auth_data->key, auth_data->key_len,
                            auth_data->key_idx);
}

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

        lockdep_assert_held(&ifmgd->mtx);

        if (len < 24 + 6)
                return RX_MGMT_NONE;

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

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

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

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

        if (auth_alg != ifmgd->auth_data->algorithm ||
            auth_transaction != ifmgd->auth_data->expected_transaction) {
                sdata_info(sdata, "%pM unexpected authentication state: alg %d (expected %d) transact %d (expected %d)\n",
                           mgmt->sa, auth_alg, ifmgd->auth_data->algorithm,
                           auth_transaction,
                           ifmgd->auth_data->expected_transaction);
                return RX_MGMT_NONE;
        }

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

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

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

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

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


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

        lockdep_assert_held(&ifmgd->mtx);

        if (len < 24 + 2)
                return RX_MGMT_NONE;

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

        bssid = ifmgd->associated->bssid;

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

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

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

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

        return RX_MGMT_CFG80211_DEAUTH;
}


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

        lockdep_assert_held(&ifmgd->mtx);

        if (len < 24 + 2)
                return RX_MGMT_NONE;

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

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

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

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

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

        return RX_MGMT_CFG80211_DISASSOC;
}

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

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

                if (rate > 110)
                        *have_higher_than_11mbit = true;

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

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

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

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

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

                memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
                ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
                ieee80211_vif_release_channel(sdata);
        }

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

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

        /* AssocResp and ReassocResp have identical structure */

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

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

        ifmgd->broken_ap = false;

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

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

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

        ifmgd->aid = aid;

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

        sband = local->hw.wiphy->bands[ieee80211_get_sdata_band(sdata)];

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

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

        rate_control_rate_init(sta);

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

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

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

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

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

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

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

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

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

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

        return true;
}

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

        lockdep_assert_held(&ifmgd->mtx);

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

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

        if (len < 24 + 6)
                return RX_MGMT_NONE;

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

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

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

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

        *bss = assoc_data->bss;

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

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

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

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

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

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

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

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

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

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

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


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

        ifmgd = &sdata->u.mgd;

        ASSERT_MGD_MTX(ifmgd);

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

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

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

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

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

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

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

static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                                     struct ieee80211_mgmt *mgmt,
                                     size_t len,
                                     struct ieee80211_rx_status *rx_status)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
        size_t baselen;
        struct ieee802_11_elems elems;
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_channel *chan;
        u32 changed = 0;
        bool erp_valid, directed_tim = false;
        u8 erp_value = 0;
        u32 ncrc;
        u8 *bssid;

        lockdep_assert_held(&ifmgd->mtx);

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

        rcu_read_lock();
        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
        if (!chanctx_conf) {
                rcu_read_unlock();
                return;
        }

        if (rx_status->freq != chanctx_conf->channel->center_freq) {
                rcu_read_unlock();
                return;
        }
        chan = chanctx_conf->channel;
        rcu_read_unlock();

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


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

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

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

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

        ieee80211_bss_info_change_notify(sdata, changed);
}

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

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

        mutex_lock(&ifmgd->mtx);

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

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

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

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

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

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

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

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

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

        mutex_lock(&ifmgd->mtx);
}

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

        lockdep_assert_held(&ifmgd->mtx);

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

        auth_data->tries++;

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

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

                return -ETIMEDOUT;
        }

        drv_mgd_prepare_tx(local, sdata);

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

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

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

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

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

        return 0;
}

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

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

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

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

                return -ETIMEDOUT;
        }

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

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

        return 0;
}

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

        mutex_lock(&ifmgd->mtx);

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

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

                        ieee80211_destroy_auth_data(sdata, false);

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

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

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

                        ieee80211_destroy_assoc_data(sdata, false);

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

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

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

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

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

                        ieee80211_sta_connection_lost(sdata, bssid,
                                WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
                }
        }

        mutex_unlock(&ifmgd->mtx);

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

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

        if (local->quiescing)
                return;

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

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

        if (local->quiescing)
                return;

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

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

        ieee80211_mgd_probe_ap(sdata, false);
}

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

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

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

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

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

        cancel_work_sync(&ifmgd->request_smps_work);

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

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

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

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

        if (!ifmgd->associated)
                return;

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

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

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

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

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

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

        mutex_init(&ifmgd->mtx);

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

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

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

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

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

        return 0;
}

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

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

        ifmgd->flags &= ~IEEE80211_STA_DISABLE_40MHZ;

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

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

        if (ht_oper) {
                const u8 *ht_cap_ie;
                const struct ieee80211_ht_cap *ht_cap;
                u8 chains = 1;

                channel_type = NL80211_CHAN_HT20;

                if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
                        switch (ht_oper->ht_param &
                                        IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
                        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
                                channel_type = NL80211_CHAN_HT40PLUS;
                                break;
                        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
                                channel_type = NL80211_CHAN_HT40MINUS;
                                break;
                        }
                }

                ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
                                             cbss->information_elements,
                                             cbss->len_information_elements);
                if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
                        ht_cap = (void *)(ht_cap_ie + 2);
                        chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
                }
                sdata->needed_rx_chains = min(chains, local->rx_chains);
        } else {
                sdata->needed_rx_chains = 1;
        }

        /* will change later if needed */
        sdata->smps_mode = IEEE80211_SMPS_OFF;

        ieee80211_vif_release_channel(sdata);
        return ieee80211_vif_use_channel(sdata, cbss->channel, channel_type,
                                         IEEE80211_CHANCTX_SHARED);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                if (assoc)
                        sta_info_pre_move_state(new_sta, IEEE80211_STA_AUTH);

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

        return 0;
}

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

        /* prepare auth data structure */

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

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

        auth_data->bss = req->bss;

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

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

        auth_data->algorithm = auth_alg;

        /* try to authenticate/probe */

        mutex_lock(&ifmgd->mtx);

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

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

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

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

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

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

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

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

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

        return err;
}

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

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

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

        mutex_lock(&ifmgd->mtx);

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

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

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

        if (ifmgd->auth_data) {
                bool match;

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

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

        ifmgd->beacon_crc_valid = false;

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

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

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

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

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

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

        assoc_data->bss = req->bss;

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

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

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

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

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

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

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

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

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

        /* kick off associate process */

        ifmgd->assoc_data = assoc_data;

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

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

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

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

        return err;
}

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

        mutex_lock(&ifmgd->mtx);

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

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

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

        mutex_unlock(&ifmgd->mtx);

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

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

        return 0;
}

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

        mutex_lock(&ifmgd->mtx);

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

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

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

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

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

        return 0;
}

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

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

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

        trace_api_cqm_rssi_notify(sdata, rssi_event);

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