/*
 * 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_TIMEOUT_LONG     (HZ / 2)
#define IEEE80211_AUTH_TIMEOUT_SHORT    (HZ / 10)
#define IEEE80211_AUTH_MAX_TRIES        3
#define IEEE80211_AUTH_WAIT_ASSOC       (HZ * 5)
#define IEEE80211_ASSOC_TIMEOUT         (HZ / 5)
#define IEEE80211_ASSOC_TIMEOUT_LONG    (HZ / 2)
#define IEEE80211_ASSOC_TIMEOUT_SHORT   (HZ / 10)
#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.
 */
static int beacon_loss_count = 7;
module_param(beacon_loss_count, int, 0644);
MODULE_PARM_DESC(beacon_loss_count,
                 "Number of beacon intervals before we decide beacon was lost.");

/*
 * 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

/*
 * 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_sub_if_data *sdata,
                      unsigned long timeout)
{
        sdata_assert_lock(sdata);

        if (!timer_pending(&sdata->u.mgd.timer) ||
            time_before(timeout, sdata->u.mgd.timer.expires))
                mod_timer(&sdata->u.mgd.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 chandef_downgrade(struct cfg80211_chan_def *c)
{
        u32 ret;
        int tmp;

        switch (c->width) {
        case NL80211_CHAN_WIDTH_20:
                c->width = NL80211_CHAN_WIDTH_20_NOHT;
                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
                break;
        case NL80211_CHAN_WIDTH_40:
                c->width = NL80211_CHAN_WIDTH_20;
                c->center_freq1 = c->chan->center_freq;
                ret = IEEE80211_STA_DISABLE_40MHZ |
                      IEEE80211_STA_DISABLE_VHT;
                break;
        case NL80211_CHAN_WIDTH_80:
                tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
                /* n_P40 */
                tmp /= 2;
                /* freq_P40 */
                c->center_freq1 = c->center_freq1 - 20 + 40 * tmp;
                c->width = NL80211_CHAN_WIDTH_40;
                ret = IEEE80211_STA_DISABLE_VHT;
                break;
        case NL80211_CHAN_WIDTH_80P80:
                c->center_freq2 = 0;
                c->width = NL80211_CHAN_WIDTH_80;
                ret = IEEE80211_STA_DISABLE_80P80MHZ |
                      IEEE80211_STA_DISABLE_160MHZ;
                break;
        case NL80211_CHAN_WIDTH_160:
                /* n_P20 */
                tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
                /* n_P80 */
                tmp /= 4;
                c->center_freq1 = c->center_freq1 - 40 + 80 * tmp;
                c->width = NL80211_CHAN_WIDTH_80;
                ret = IEEE80211_STA_DISABLE_80P80MHZ |
                      IEEE80211_STA_DISABLE_160MHZ;
                break;
        default:
        case NL80211_CHAN_WIDTH_20_NOHT:
                WARN_ON_ONCE(1);
                c->width = NL80211_CHAN_WIDTH_20_NOHT;
                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
                break;
        case NL80211_CHAN_WIDTH_5:
        case NL80211_CHAN_WIDTH_10:
                WARN_ON_ONCE(1);
                /* keep c->width */
                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
                break;
        }

        WARN_ON_ONCE(!cfg80211_chandef_valid(c));

        return ret;
}

static u32
ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
                             struct ieee80211_supported_band *sband,
                             struct ieee80211_channel *channel,
                             const struct ieee80211_ht_operation *ht_oper,
                             const struct ieee80211_vht_operation *vht_oper,
                             struct cfg80211_chan_def *chandef, bool tracking)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct cfg80211_chan_def vht_chandef;
        u32 ht_cfreq, ret;

        chandef->chan = channel;
        chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
        chandef->center_freq1 = channel->center_freq;
        chandef->center_freq2 = 0;

        if (!ht_oper || !sband->ht_cap.ht_supported) {
                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        chandef->width = NL80211_CHAN_WIDTH_20;

        ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
                                                  channel->band);
        /* check that channel matches the right operating channel */
        if (!tracking && 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",
                           channel->center_freq, ht_cfreq,
                           ht_oper->primary_chan, channel->band);
                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        /* check 40 MHz support, if we have it */
        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:
                        chandef->width = NL80211_CHAN_WIDTH_40;
                        chandef->center_freq1 += 10;
                        break;
                case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
                        chandef->width = NL80211_CHAN_WIDTH_40;
                        chandef->center_freq1 -= 10;
                        break;
                }
        } else {
                /* 40 MHz (and 80 MHz) must be supported for VHT */
                ret = IEEE80211_STA_DISABLE_VHT;
                /* also mark 40 MHz disabled */
                ret |= IEEE80211_STA_DISABLE_40MHZ;
                goto out;
        }

        if (!vht_oper || !sband->vht_cap.vht_supported) {
                ret = IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        vht_chandef.chan = channel;
        vht_chandef.center_freq1 =
                ieee80211_channel_to_frequency(vht_oper->center_freq_seg1_idx,
                                               channel->band);
        vht_chandef.center_freq2 = 0;

        switch (vht_oper->chan_width) {
        case IEEE80211_VHT_CHANWIDTH_USE_HT:
                vht_chandef.width = chandef->width;
                break;
        case IEEE80211_VHT_CHANWIDTH_80MHZ:
                vht_chandef.width = NL80211_CHAN_WIDTH_80;
                break;
        case IEEE80211_VHT_CHANWIDTH_160MHZ:
                vht_chandef.width = NL80211_CHAN_WIDTH_160;
                break;
        case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
                vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
                vht_chandef.center_freq2 =
                        ieee80211_channel_to_frequency(
                                vht_oper->center_freq_seg2_idx,
                                channel->band);
                break;
        default:
                if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                        sdata_info(sdata,
                                   "AP VHT operation IE has invalid channel width (%d), disable VHT\n",
                                   vht_oper->chan_width);
                ret = IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        if (!cfg80211_chandef_valid(&vht_chandef)) {
                if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                        sdata_info(sdata,
                                   "AP VHT information is invalid, disable VHT\n");
                ret = IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        if (cfg80211_chandef_identical(chandef, &vht_chandef)) {
                ret = 0;
                goto out;
        }

        if (!cfg80211_chandef_compatible(chandef, &vht_chandef)) {
                if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                        sdata_info(sdata,
                                   "AP VHT information doesn't match HT, disable VHT\n");
                ret = IEEE80211_STA_DISABLE_VHT;
                goto out;
        }

        *chandef = vht_chandef;

        ret = 0;

out:
        /* don't print the message below for VHT mismatch if VHT is disabled */
        if (ret & IEEE80211_STA_DISABLE_VHT)
                vht_chandef = *chandef;

        /*
         * Ignore the DISABLED flag when we're already connected and only
         * tracking the APs beacon for bandwidth changes - otherwise we
         * might get disconnected here if we connect to an AP, update our
         * regulatory information based on the AP's country IE and the
         * information we have is wrong/outdated and disables the channel
         * that we're actually using for the connection to the AP.
         */
        while (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
                                        tracking ? 0 :
                                                   IEEE80211_CHAN_DISABLED)) {
                if (WARN_ON(chandef->width == NL80211_CHAN_WIDTH_20_NOHT)) {
                        ret = IEEE80211_STA_DISABLE_HT |
                              IEEE80211_STA_DISABLE_VHT;
                        break;
                }

                ret |= chandef_downgrade(chandef);
        }

        if (chandef->width != vht_chandef.width && !tracking)
                sdata_info(sdata,
                           "capabilities/regulatory prevented using AP HT/VHT configuration, downgraded\n");

        WARN_ON_ONCE(!cfg80211_chandef_valid(chandef));
        return ret;
}

static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
                               struct sta_info *sta,
                               const struct ieee80211_ht_operation *ht_oper,
                               const struct ieee80211_vht_operation *vht_oper,
                               const u8 *bssid, u32 *changed)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_supported_band *sband;
        struct ieee80211_channel *chan;
        struct cfg80211_chan_def chandef;
        u16 ht_opmode;
        u32 flags;
        enum ieee80211_sta_rx_bandwidth new_sta_bw;
        int ret;

        /* if HT was/is disabled, don't track any bandwidth changes */
        if (ifmgd->flags & IEEE80211_STA_DISABLE_HT || !ht_oper)
                return 0;

        /* don't check VHT if we associated as non-VHT station */
        if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
                vht_oper = NULL;

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

        chan = sdata->vif.bss_conf.chandef.chan;
        sband = local->hw.wiphy->bands[chan->band];

        /* calculate new channel (type) based on HT/VHT operation IEs */
        flags = ieee80211_determine_chantype(sdata, sband, chan, ht_oper,
                                             vht_oper, &chandef, true);

        /*
         * Downgrade the new channel if we associated with restricted
         * capabilities. For example, if we associated as a 20 MHz STA
         * to a 40 MHz AP (due to regulatory, capabilities or config
         * reasons) then switching to a 40 MHz channel now won't do us
         * any good -- we couldn't use it with the AP.
         */
        if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
            chandef.width == NL80211_CHAN_WIDTH_80P80)
                flags |= chandef_downgrade(&chandef);
        if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
            chandef.width == NL80211_CHAN_WIDTH_160)
                flags |= chandef_downgrade(&chandef);
        if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
            chandef.width > NL80211_CHAN_WIDTH_20)
                flags |= chandef_downgrade(&chandef);

        if (cfg80211_chandef_identical(&chandef, &sdata->vif.bss_conf.chandef))
                return 0;

        sdata_info(sdata,
                   "AP %pM changed bandwidth, new config is %d MHz, width %d (%d/%d MHz)\n",
                   ifmgd->bssid, chandef.chan->center_freq, chandef.width,
                   chandef.center_freq1, chandef.center_freq2);

        if (flags != (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |
                                      IEEE80211_STA_DISABLE_VHT |
                                      IEEE80211_STA_DISABLE_40MHZ |
                                      IEEE80211_STA_DISABLE_80P80MHZ |
                                      IEEE80211_STA_DISABLE_160MHZ)) ||
            !cfg80211_chandef_valid(&chandef)) {
                sdata_info(sdata,
                           "AP %pM changed bandwidth in a way we can't support - disconnect\n",
                           ifmgd->bssid);
                return -EINVAL;
        }

        switch (chandef.width) {
        case NL80211_CHAN_WIDTH_20_NOHT:
        case NL80211_CHAN_WIDTH_20:
                new_sta_bw = IEEE80211_STA_RX_BW_20;
                break;
        case NL80211_CHAN_WIDTH_40:
                new_sta_bw = IEEE80211_STA_RX_BW_40;
                break;
        case NL80211_CHAN_WIDTH_80:
                new_sta_bw = IEEE80211_STA_RX_BW_80;
                break;
        case NL80211_CHAN_WIDTH_80P80:
        case NL80211_CHAN_WIDTH_160:
                new_sta_bw = IEEE80211_STA_RX_BW_160;
                break;
        default:
                return -EINVAL;
        }

        if (new_sta_bw > sta->cur_max_bandwidth)
                new_sta_bw = sta->cur_max_bandwidth;

        if (new_sta_bw < sta->sta.bandwidth) {
                sta->sta.bandwidth = new_sta_bw;
                rate_control_rate_update(local, sband, sta,
                                         IEEE80211_RC_BW_CHANGED);
        }

        ret = ieee80211_vif_change_bandwidth(sdata, &chandef, changed);
        if (ret) {
                sdata_info(sdata,
                           "AP %pM changed bandwidth to incompatible one - disconnect\n",
                           ifmgd->bssid);
                return ret;
        }

        if (new_sta_bw > sta->sta.bandwidth) {
                sta->sta.bandwidth = new_sta_bw;
                rate_control_rate_update(local, sband, sta,
                                         IEEE80211_RC_BW_CHANGED);
        }

        ht_opmode = le16_to_cpu(ht_oper->operation_mode);

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

        return 0;
}

/* 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,
                                 struct ieee80211_vht_cap *ap_vht_cap)
{
        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));
        ieee80211_apply_vhtcap_overrides(sdata, &vht_cap);

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

        if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_80P80MHZ) {
                cap &= ~IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ;
                cap |= IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
        }

        if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_160MHZ) {
                cap &= ~IEEE80211_VHT_CAP_SHORT_GI_160;
                cap &= ~IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
        }

        /*
         * Some APs apparently get confused if our capabilities are better
         * than theirs, so restrict what we advertise in the assoc request.
         */
        if (!(ap_vht_cap->vht_cap_info &
                        cpu_to_le32(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)))
                cap &= ~IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE;

        /* reserve and fill IE */
        pos = skb_put(skb, sizeof(struct ieee80211_vht_cap) + 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;

        sdata_assert_lock(sdata);

        rcu_read_lock();
        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
        if (WARN_ON(!chanctx_conf)) {
                rcu_read_unlock();
                return;
        }
        chan = chanctx_conf->def.chan;
        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_cap) + /* 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 (WARN_ON_ONCE((ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
                         !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT)))
                ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;

        if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT))
                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,
                                     &assoc_data->ap_vht_cap);

        /* 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;
        if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
                IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS |
                                                IEEE80211_TX_INTFL_MLME_CONN_TX;
        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 |
                                        IEEE80211_TX_INTFL_OFFCHAN_TX_OK;

        if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
                IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

        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_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

        if (!ieee80211_sdata_running(sdata))
                return;

        sdata_lock(sdata);
        if (!ifmgd->associated)
                goto out;

        local->_oper_chandef = local->csa_chandef;

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

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

        /* XXX: wait for a beacon first? */
        ieee80211_wake_queues_by_reason(&local->hw,
                                        IEEE80211_MAX_QUEUE_MAP,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);
 out:
        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
        sdata_unlock(sdata);
}

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;

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

}

static void
ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                 u64 timestamp, struct ieee802_11_elems *elems,
                                 bool beacon)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct cfg80211_bss *cbss = ifmgd->associated;
        struct ieee80211_bss *bss;
        struct ieee80211_chanctx *chanctx;
        enum ieee80211_band new_band;
        int new_freq;
        u8 new_chan_no;
        u8 count;
        u8 mode;
        struct ieee80211_channel *new_chan;
        struct cfg80211_chan_def new_chandef = {};
        struct cfg80211_chan_def new_vht_chandef = {};
        const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
        const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
        const struct ieee80211_ht_operation *ht_oper;
        int secondary_channel_offset = -1;

        sdata_assert_lock(sdata);

        if (!cbss)
                return;

        if (local->scanning)
                return;

        /* disregard subsequent announcements if we are already processing */
        if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                return;

        sec_chan_offs = elems->sec_chan_offs;
        wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
        ht_oper = elems->ht_operation;

        if (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |
                            IEEE80211_STA_DISABLE_40MHZ)) {
                sec_chan_offs = NULL;
                wide_bw_chansw_ie = NULL;
                /* only used for bandwidth here */
                ht_oper = NULL;
        }

        if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
                wide_bw_chansw_ie = NULL;

        if (elems->ext_chansw_ie) {
                if (!ieee80211_operating_class_to_band(
                                elems->ext_chansw_ie->new_operating_class,
                                &new_band)) {
                        sdata_info(sdata,
                                   "cannot understand ECSA IE operating class %d, disconnecting\n",
                                   elems->ext_chansw_ie->new_operating_class);
                        ieee80211_queue_work(&local->hw,
                                             &ifmgd->csa_connection_drop_work);
                }
                new_chan_no = elems->ext_chansw_ie->new_ch_num;
                count = elems->ext_chansw_ie->count;
                mode = elems->ext_chansw_ie->mode;
        } else if (elems->ch_switch_ie) {
                new_band = cbss->channel->band;
                new_chan_no = elems->ch_switch_ie->new_ch_num;
                count = elems->ch_switch_ie->count;
                mode = elems->ch_switch_ie->mode;
        } else {
                /* nothing here we understand */
                return;
        }

        bss = (void *)cbss->priv;

        new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
        new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
        if (!new_chan || new_chan->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(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                return;
        }

        if (!beacon && sec_chan_offs) {
                secondary_channel_offset = sec_chan_offs->sec_chan_offs;
        } else if (beacon && ht_oper) {
                secondary_channel_offset =
                        ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET;
        } else if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
                /*
                 * If it's not a beacon, HT is enabled and the IE not present,
                 * it's 20 MHz, 802.11-2012 8.5.2.6:
                 *      This element [the Secondary Channel Offset Element] is
                 *      present when switching to a 40 MHz channel. It may be
                 *      present when switching to a 20 MHz channel (in which
                 *      case the secondary channel offset is set to SCN).
                 */
                secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
        }

        switch (secondary_channel_offset) {
        default:
                /* secondary_channel_offset was present but is invalid */
        case IEEE80211_HT_PARAM_CHA_SEC_NONE:
                cfg80211_chandef_create(&new_chandef, new_chan,
                                        NL80211_CHAN_HT20);
                break;
        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
                cfg80211_chandef_create(&new_chandef, new_chan,
                                        NL80211_CHAN_HT40PLUS);
                break;
        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
                cfg80211_chandef_create(&new_chandef, new_chan,
                                        NL80211_CHAN_HT40MINUS);
                break;
        case -1:
                cfg80211_chandef_create(&new_chandef, new_chan,
                                        NL80211_CHAN_NO_HT);
                break;
        }

        if (wide_bw_chansw_ie) {
                new_vht_chandef.chan = new_chan;
                new_vht_chandef.center_freq1 =
                        ieee80211_channel_to_frequency(
                                wide_bw_chansw_ie->new_center_freq_seg0,
                                new_band);

                switch (wide_bw_chansw_ie->new_channel_width) {
                default:
                        /* hmmm, ignore VHT and use HT if present */
                case IEEE80211_VHT_CHANWIDTH_USE_HT:
                        new_vht_chandef.chan = NULL;
                        break;
                case IEEE80211_VHT_CHANWIDTH_80MHZ:
                        new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
                        break;
                case IEEE80211_VHT_CHANWIDTH_160MHZ:
                        new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
                        break;
                case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
                        /* field is otherwise reserved */
                        new_vht_chandef.center_freq2 =
                                ieee80211_channel_to_frequency(
                                        wide_bw_chansw_ie->new_center_freq_seg1,
                                        new_band);
                        new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
                        break;
                }
                if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
                    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
                        chandef_downgrade(&new_vht_chandef);
                if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
                    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
                        chandef_downgrade(&new_vht_chandef);
                if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
                    new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
                        chandef_downgrade(&new_vht_chandef);
        }

        /* if VHT data is there validate & use it */
        if (new_vht_chandef.chan) {
                if (!cfg80211_chandef_compatible(&new_vht_chandef,
                                                 &new_chandef)) {
                        sdata_info(sdata,
                                   "AP %pM CSA has inconsistent channel data, disconnecting\n",
                                   ifmgd->associated->bssid);
                        ieee80211_queue_work(&local->hw,
                                             &ifmgd->csa_connection_drop_work);
                        return;
                }
                new_chandef = new_vht_chandef;
        }

        if (!cfg80211_chandef_usable(local->hw.wiphy, &new_chandef,
                                     IEEE80211_CHAN_DISABLED)) {
                sdata_info(sdata,
                           "AP %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
                           ifmgd->associated->bssid, new_freq,
                           new_chandef.width, new_chandef.center_freq1,
                           new_chandef.center_freq2);
                ieee80211_queue_work(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                return;
        }

        ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;

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

        mutex_lock(&local->chanctx_mtx);
        if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
                mutex_unlock(&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(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                mutex_unlock(&local->chanctx_mtx);
                return;
        }
        mutex_unlock(&local->chanctx_mtx);

        local->csa_chandef = new_chandef;

        if (mode)
                ieee80211_stop_queues_by_reason(&local->hw,
                                IEEE80211_MAX_QUEUE_MAP,
                                IEEE80211_QUEUE_STOP_REASON_CSA);

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

                drv_channel_switch(local, &ch_switch);
                return;
        }

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

static u32 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 0;

        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 0;

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

        if (sdata->ap_power_level == new_ap_level)
                return 0;

        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->ap_power_level = new_ap_level;
        if (__ieee80211_recalc_txpower(sdata))
                return BSS_CHANGED_TXPOWER;
        return 0;
}

/* 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;

        if (!mgd->have_beacon)
                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)) {
                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->hw.conf.dynamic_ps_timeout = timeout;

                if (beaconint_us > latency) {
                        local->ps_sdata = NULL;
                } else {
                        int maxslp = 1;
                        u8 dtimper = found->u.mgd.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_MAX_QUEUE_MAP,
                                        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->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)) {
                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 */
                        ieee80211_flush_queues(local, sdata);
                }
        }

        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);
        }
}

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);
}

void ieee80211_dfs_cac_timer_work(struct work_struct *work)
{
        struct delayed_work *delayed_work =
                container_of(work, struct delayed_work, work);
        struct ieee80211_sub_if_data *sdata =
                container_of(delayed_work, struct ieee80211_sub_if_data,
                             dfs_cac_timer_work);

        ieee80211_vif_release_channel(sdata);

        cfg80211_cac_event(sdata->dev, NL80211_RADAR_CAC_FINISHED, GFP_KERNEL);
}

/* MLME */
static bool ieee80211_sta_wmm_params(struct ieee80211_local *local,
                                     struct ieee80211_sub_if_data *sdata,
                                     const 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;
        const u8 *pos;
        u8 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.acm = acm;
                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(
                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;

        if (sdata->vif.p2p) {
                const struct cfg80211_bss_ies *ies;

                rcu_read_lock();
                ies = rcu_dereference(cbss->ies);
                if (ies) {
                        int ret;

                        ret = cfg80211_get_p2p_attr(
                                        ies->data, ies->len,
                                        IEEE80211_P2P_ATTR_ABSENCE_NOTICE,
                                        (u8 *) &bss_conf->p2p_noa_attr,
                                        sizeof(bss_conf->p2p_noa_attr));
                        if (ret >= 2) {
                                sdata->u.mgd.p2p_noa_index =
                                        bss_conf->p2p_noa_attr.index;
                                bss_info_changed |= BSS_CHANGED_P2P_PS;
                        }
                }
                rcu_read_unlock();
        }

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

        ieee80211_led_assoc(local, 1);

        if (sdata->u.mgd.have_beacon) {
                /*
                 * If the AP is buggy we may get here with no DTIM period
                 * known, so assume it's 1 which is the only safe assumption
                 * in that case, although if the TIM IE is broken powersave
                 * probably just won't work at all.
                 */
                bss_conf->dtim_period = sdata->u.mgd.dtim_period ?: 1;
                bss_conf->beacon_rate = bss->beacon_rate;
                bss_info_changed |= BSS_CHANGED_BEACON_INFO;
        } else {
                bss_conf->beacon_rate = NULL;
                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_addr_cnt)
                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_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;
        u32 changed = 0;

        sdata_assert_lock(sdata);

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

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

        ieee80211_stop_poll(sdata);

        ifmgd->associated = NULL;
        netif_carrier_off(sdata->dev);

        /*
         * 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)
                ieee80211_flush_queues(local, sdata);

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

        /* flush out frame */
        if (tx)
                ieee80211_flush_queues(local, sdata);

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

        /* remove AP and TDLS peers */
        sta_info_flush_defer(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;

        ifmgd->p2p_noa_index = -1;
        memset(&sdata->vif.bss_conf.p2p_noa_attr, 0,
               sizeof(sdata->vif.bss_conf.p2p_noa_attr));

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

        sdata->ap_power_level = IEEE80211_UNSET_POWER_LEVEL;

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

        /* Disable ARP filtering */
        if (sdata->vif.bss_conf.arp_addr_cnt)
                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);

        /* 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->vif.bss_conf.dtim_period = 0;
        sdata->vif.bss_conf.beacon_rate = NULL;

        ifmgd->have_beacon = false;

        ifmgd->flags = 0;
        ieee80211_vif_release_channel(sdata);
}

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 (ieee80211_is_nullfunc(hdr->frame_control) &&
            sdata->u.mgd.probe_send_count > 0) {
                if (ack)
                        ieee80211_sta_reset_conn_monitor(sdata);
                else
                        sdata->u.mgd.nullfunc_failed = true;
                ieee80211_queue_work(&sdata->local->hw, &sdata->work);
                return;
        }

        if (ack)
                ieee80211_sta_reset_conn_monitor(sdata);
}

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;

                rcu_read_lock();
                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, 0,
                                         ifmgd->associated->channel, false);
                rcu_read_unlock();
        }

        ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
        run_again(sdata, ifmgd->probe_timeout);
        if (sdata->local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
                ieee80211_flush_queues(sdata->local, sdata);
}

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;

        sdata_lock(sdata);

        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 (missed %d beacons) - probing\n",
                                     beacon_loss_count);

                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:
        sdata_unlock(sdata);
}

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;

        sdata_assert_lock(sdata);

        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;

        rcu_read_lock();
        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);
        rcu_read_unlock();

        return skb;
}
EXPORT_SYMBOL(ieee80211_ap_probereq_get);

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

        sdata_lock(sdata);
        if (!ifmgd->associated) {
                sdata_unlock(sdata);
                return;
        }

        ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
                               WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
                               true, frame_buf);
        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
        ieee80211_wake_queues_by_reason(&sdata->local->hw,
                                        IEEE80211_MAX_QUEUE_MAP,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);

        cfg80211_tx_mlme_mgmt(sdata->dev, frame_buf,
                              IEEE80211_DEAUTH_FRAME_LEN);
        sdata_unlock(sdata);
}

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 (ifmgd->connection_loss) {
                sdata_info(sdata, "Connection to AP %pM lost\n",
                           ifmgd->bssid);
                __ieee80211_disconnect(sdata);
        } 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_disconnect(sdata);
}

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);

        sdata->u.mgd.connection_loss = false;
        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);

        sdata->u.mgd.connection_loss = true;
        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;

        sdata_assert_lock(sdata);

        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);
                sdata->u.mgd.flags = 0;
                ieee80211_vif_release_channel(sdata);
        }

        cfg80211_put_bss(sdata->local->hw.wiphy, 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_local *local = sdata->local;
        struct ieee80211_mgd_auth_data *auth_data = sdata->u.mgd.auth_data;
        u8 *pos;
        struct ieee802_11_elems elems;
        u32 tx_flags = 0;

        pos = mgmt->u.auth.variable;
        ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), false, &elems);
        if (!elems.challenge)
                return;
        auth_data->expected_transaction = 4;
        drv_mgd_prepare_tx(sdata->local, sdata);
        if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
                tx_flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
                           IEEE80211_TX_INTFL_MLME_CONN_TX;
        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, tx_flags);
}

static void 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;

        sdata_assert_lock(sdata);

        if (len < 24 + 6)
                return;

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

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

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

        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;
        }

        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);
                cfg80211_rx_mlme_mgmt(sdata->dev, (u8 *)mgmt, len);
                return;
        }

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

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

        if (ifmgd->auth_data->algorithm == WLAN_AUTH_SAE &&
            ifmgd->auth_data->expected_transaction != 2) {
                /*
                 * Report auth frame to user space for processing since another
                 * round of Authentication frames is still needed.
                 */
                cfg80211_rx_mlme_mgmt(sdata->dev, (u8 *)mgmt, len);
                return;
        }

        /* 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);

        cfg80211_rx_mlme_mgmt(sdata->dev, (u8 *)mgmt, len);
        return;
 out_err:
        mutex_unlock(&sdata->local->sta_mtx);
        /* ignore frame -- wait for timeout */
}


static void 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;

        sdata_assert_lock(sdata);

        if (len < 24 + 2)
                return;

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

        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);

        cfg80211_rx_mlme_mgmt(sdata->dev, (u8 *)mgmt, len);
}


static void 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;

        sdata_assert_lock(sdata);

        if (len < 24 + 2)
                return;

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

        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);

        cfg80211_rx_mlme_mgmt(sdata->dev, (u8 *)mgmt, len);
}

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;

        sdata_assert_lock(sdata);

        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);
                sdata->u.mgd.flags = 0;
                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;
        const struct cfg80211_bss_ies *bss_ies = NULL;
        struct ieee80211_mgd_assoc_data *assoc_data = ifmgd->assoc_data;
        u32 changed = 0;
        int err;
        bool ret;

        /* 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), false, &elems);

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

        ifmgd->aid = aid;

        /*
         * Some APs are erroneously not including some information in their
         * (re)association response frames. Try to recover by using the data
         * from the beacon or probe response. This seems to afflict mobile
         * 2G/3G/4G wifi routers, reported models include the "Onda PN51T",
         * "Vodafone PocketWiFi 2", "ZTE MF60" and a similar T-Mobile device.
         */
        if ((assoc_data->wmm && !elems.wmm_param) ||
            (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
             (!elems.ht_cap_elem || !elems.ht_operation)) ||
            (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT) &&
             (!elems.vht_cap_elem || !elems.vht_operation))) {
                const struct cfg80211_bss_ies *ies;
                struct ieee802_11_elems bss_elems;

                rcu_read_lock();
                ies = rcu_dereference(cbss->ies);
                if (ies)
                        bss_ies = kmemdup(ies, sizeof(*ies) + ies->len,
                                          GFP_ATOMIC);
                rcu_read_unlock();
                if (!bss_ies)
                        return false;

                ieee802_11_parse_elems(bss_ies->data, bss_ies->len,
                                       false, &bss_elems);
                if (assoc_data->wmm &&
                    !elems.wmm_param && bss_elems.wmm_param) {
                        elems.wmm_param = bss_elems.wmm_param;
                        sdata_info(sdata,
                                   "AP bug: WMM param missing from AssocResp\n");
                }

                /*
                 * Also check if we requested HT/VHT, otherwise the AP doesn't
                 * have to include the IEs in the (re)association response.
                 */
                if (!elems.ht_cap_elem && bss_elems.ht_cap_elem &&
                    !(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
                        elems.ht_cap_elem = bss_elems.ht_cap_elem;
                        sdata_info(sdata,
                                   "AP bug: HT capability missing from AssocResp\n");
                }
                if (!elems.ht_operation && bss_elems.ht_operation &&
                    !(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
                        elems.ht_operation = bss_elems.ht_operation;
                        sdata_info(sdata,
                                   "AP bug: HT operation missing from AssocResp\n");
                }
                if (!elems.vht_cap_elem && bss_elems.vht_cap_elem &&
                    !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT)) {
                        elems.vht_cap_elem = bss_elems.vht_cap_elem;
                        sdata_info(sdata,
                                   "AP bug: VHT capa missing from AssocResp\n");
                }
                if (!elems.vht_operation && bss_elems.vht_operation &&
                    !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT)) {
                        elems.vht_operation = bss_elems.vht_operation;
                        sdata_info(sdata,
                                   "AP bug: VHT operation missing from AssocResp\n");
                }
        }

        /*
         * We previously checked these in the beacon/probe response, so
         * they should be present here. This is just a safety net.
         */
        if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
            (!elems.wmm_param || !elems.ht_cap_elem || !elems.ht_operation)) {
                sdata_info(sdata,
                           "HT AP is missing WMM params or HT capability/operation\n");
                ret = false;
                goto out;
        }

        if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT) &&
            (!elems.vht_cap_elem || !elems.vht_operation)) {
                sdata_info(sdata,
                           "VHT AP is missing VHT capability/operation\n");
                ret = false;
                goto out;
        }

        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);
                ret = false;
                goto out;
        }

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

        /* Set up internal HT/VHT capabilities */
        if (elems.ht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_HT))
                ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
                                                  elems.ht_cap_elem, sta);

        if (elems.vht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
                                                    elems.vht_cap_elem, sta);

        /*
         * Some APs, e.g. Netgear WNDR3700, report invalid HT operation data
         * in their association response, so ignore that data for our own
         * configuration. If it changed since the last beacon, we'll get the
         * next beacon and update then.
         */

        /*
         * If an operating mode notification IE is present, override the
         * NSS calculation (that would be done in rate_control_rate_init())
         * and use the # of streams from that element.
         */
        if (elems.opmode_notif &&
            !(*elems.opmode_notif & IEEE80211_OPMODE_NOTIF_RX_NSS_TYPE_BF)) {
                u8 nss;

                nss = *elems.opmode_notif & IEEE80211_OPMODE_NOTIF_RX_NSS_MASK;
                nss >>= IEEE80211_OPMODE_NOTIF_RX_NSS_SHIFT;
                nss += 1;
                sta->sta.rx_nss = nss;
        }

        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_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);
                ret = false;
                goto out;
        }

        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;

        /* 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);

        ret = true;
 out:
        kfree(bss_ies);
        return ret;
}

static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
                                         struct ieee80211_mgmt *mgmt,
                                         size_t len)
{
        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;
        struct cfg80211_bss *bss;

        sdata_assert_lock(sdata);

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

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

        if (len < 24 + 6)
                return;

        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), false, &elems);

        if (status_code == WLAN_STATUS_ASSOC_REJECTED_TEMPORARILY &&
            elems.timeout_int &&
            elems.timeout_int->type == WLAN_TIMEOUT_ASSOC_COMEBACK) {
                u32 tu, ms;
                tu = le32_to_cpu(elems.timeout_int->value);
                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);
                assoc_data->timeout_started = true;
                if (ms > IEEE80211_ASSOC_TIMEOUT)
                        run_again(sdata, assoc_data->timeout);
                return;
        }

        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_assoc_timeout(sdata->dev, bss);
                        return;
                }
                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);
        }

        cfg80211_rx_assoc_resp(sdata->dev, bss, (u8 *)mgmt, len);
}

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)
{
        struct ieee80211_local *local = sdata->local;
        int freq;
        struct ieee80211_bss *bss;
        struct ieee80211_channel *channel;

        sdata_assert_lock(sdata);

        if (elems->ds_params)
                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);
        if (bss) {
                ieee80211_rx_bss_put(local, bss);
                sdata->vif.bss_conf.beacon_rate = bss->beacon_rate;
        }

        if (!sdata->u.mgd.associated ||
            !ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid))
                return;

        ieee80211_sta_process_chanswitch(sdata, rx_status->mactime,
                                         elems, true);

}


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;

        sdata_assert_lock(sdata);

        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,
                               false, &elems);

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

        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;
                ifmgd->auth_data->timeout_started = true;
                run_again(sdata, 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;
        struct sta_info *sta;
        u32 changed = 0;
        bool erp_valid;
        u8 erp_value = 0;
        u32 ncrc;
        u8 *bssid;
        u8 deauth_buf[IEEE80211_DEAUTH_FRAME_LEN];

        sdata_assert_lock(sdata);

        /* 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->def.chan->center_freq) {
                rcu_read_unlock();
                return;
        }
        chan = chanctx_conf->def.chan;
        rcu_read_unlock();

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

                ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
                if (elems.tim && !elems.parse_error) {
                        const struct ieee80211_tim_ie *tim_ie = elems.tim;
                        ifmgd->dtim_period = tim_ie->dtim_period;
                }
                ifmgd->have_beacon = true;
                ifmgd->assoc_data->need_beacon = false;
                if (local->hw.flags & IEEE80211_HW_TIMING_BEACON_ONLY) {
                        sdata->vif.bss_conf.sync_tsf =
                                le64_to_cpu(mgmt->u.beacon.timestamp);
                        sdata->vif.bss_conf.sync_device_ts =
                                rx_status->device_timestamp;
                        if (elems.tim)
                                sdata->vif.bss_conf.sync_dtim_count =
                                        elems.tim->dtim_count;
                        else
                                sdata->vif.bss_conf.sync_dtim_count = 0;
                }
                /* continue assoc process */
                ifmgd->assoc_data->timeout = jiffies;
                ifmgd->assoc_data->timeout_started = true;
                run_again(sdata, ifmgd->assoc_data->timeout);
                return;
        }

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