mac80211: fix MLME issuing of probe requests while scanning

[safe/jmp/linux-2.6] / net / mac80211 / mlme.c

/*
 * BSS client mode implementation
 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/pm_qos_params.h>
#include <linux/crc32.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

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

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

/*
 * beacon loss detection timeout
 * XXX: should depend on beacon interval
 */
#define IEEE80211_BEACON_LOSS_TIME      (2 * HZ)
/*
 * 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  (2 * HZ)
/*
 * Time we wait for a probe response after sending
 * a probe request because of beacon loss or for
 * checking the connection still works.
 */
#define IEEE80211_PROBE_WAIT            (HZ / 5)

#define TMR_RUNNING_TIMER       0
#define TMR_RUNNING_CHANSW      1

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

        /* caller must call cfg80211_send_rx_auth() */
        RX_MGMT_CFG80211_AUTH,

        /* caller must call cfg80211_send_rx_assoc() */
        RX_MGMT_CFG80211_ASSOC,

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

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

        /* caller must call cfg80211_auth_timeout() & free work */
        RX_MGMT_CFG80211_AUTH_TO,

        /* caller must call cfg80211_assoc_timeout() & free work */
        RX_MGMT_CFG80211_ASSOC_TO,
};

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

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

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

static void mod_beacon_timer(struct ieee80211_sub_if_data *sdata)
{
        if (sdata->local->hw.flags & IEEE80211_HW_BEACON_FILTER)
                return;

        mod_timer(&sdata->u.mgd.bcn_mon_timer,
                  round_jiffies_up(jiffies + IEEE80211_BEACON_LOSS_TIME));
}

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

static int ieee80211_compatible_rates(struct ieee80211_bss *bss,
                                      struct ieee80211_supported_band *sband,
                                      u32 *rates)
{
        int i, j, count;
        *rates = 0;
        count = 0;
        for (i = 0; i < bss->supp_rates_len; i++) {
                int rate = (bss->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;
}

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

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

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

        /* check that channel matches the right operating channel */
        if (local->hw.conf.channel->center_freq !=
            ieee80211_channel_to_frequency(hti->control_chan))
                enable_ht = false;

        if (enable_ht) {
                channel_type = NL80211_CHAN_HT20;

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

        ht_changed = conf_is_ht(&local->hw.conf) != enable_ht ||
                     channel_type != local->hw.conf.channel_type;

        local->oper_channel_type = channel_type;

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

                rcu_read_lock();
                sta = sta_info_get(local, bssid);
                if (sta)
                        rate_control_rate_update(local, sband, sta,
                                                 IEEE80211_RC_HT_CHANGED);
                rcu_read_unlock();
        }

        /* disable HT */
        if (!enable_ht)
                return 0;

        ht_opmode = le16_to_cpu(hti->operation_mode);

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

        return changed;
}

/* frame sending functions */

static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata,
                                 struct ieee80211_mgd_work *wk)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u8 *pos;
        const u8 *ies, *ht_ie;
        int i, len, count, rates_len, supp_rates_len;
        u16 capab;
        int wmm = 0;
        struct ieee80211_supported_band *sband;
        u32 rates = 0;

        skb = dev_alloc_skb(local->hw.extra_tx_headroom +
                            sizeof(*mgmt) + 200 + wk->ie_len +
                            wk->ssid_len);
        if (!skb) {
                printk(KERN_DEBUG "%s: failed to allocate buffer for assoc "
                       "frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);

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

        capab = ifmgd->capab;

        if (local->hw.conf.channel->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 (wk->bss->cbss.capability & WLAN_CAPABILITY_PRIVACY)
                capab |= WLAN_CAPABILITY_PRIVACY;
        if (wk->bss->wmm_used)
                wmm = 1;

        /* 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(wk->bss, sband, &rates);

        if ((wk->bss->cbss.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, wk->bss->cbss.bssid, ETH_ALEN);
        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
        memcpy(mgmt->bssid, wk->bss->cbss.bssid, ETH_ALEN);

        if (!is_zero_ether_addr(wk->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, wk->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 */
        ies = pos = skb_put(skb, 2 + wk->ssid_len);
        *pos++ = WLAN_EID_SSID;
        *pos++ = wk->ssid_len;
        memcpy(pos, wk->ssid, wk->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;

        len = sband->n_bitrates;
        pos = skb_put(skb, supp_rates_len + 2);
        *pos++ = WLAN_EID_SUPP_RATES;
        *pos++ = supp_rates_len;

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

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

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

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

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

        if (wk->ie_len && wk->ie) {
                pos = skb_put(skb, wk->ie_len);
                memcpy(pos, wk->ie, wk->ie_len);
        }

        if (wmm && (ifmgd->flags & IEEE80211_STA_WMM_ENABLED)) {
                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++ = 0;
        }

        /* wmm support is a must to HT */
        /*
         * IEEE802.11n does not allow TKIP/WEP as pairwise
         * ciphers in HT mode. We still associate in non-ht
         * mode (11a/b/g) if any one of these ciphers is
         * configured as pairwise.
         */
        if (wmm && (ifmgd->flags & IEEE80211_STA_WMM_ENABLED) &&
            sband->ht_cap.ht_supported &&
            (ht_ie = ieee80211_bss_get_ie(&wk->bss->cbss, WLAN_EID_HT_INFORMATION)) &&
            ht_ie[1] >= sizeof(struct ieee80211_ht_info) &&
            (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))) {
                struct ieee80211_ht_info *ht_info =
                        (struct ieee80211_ht_info *)(ht_ie + 2);
                u16 cap = sband->ht_cap.cap;
                __le16 tmp;
                u32 flags = local->hw.conf.channel->flags;

                switch (ht_info->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;
                }

                tmp = cpu_to_le16(cap);
                pos = skb_put(skb, sizeof(struct ieee80211_ht_cap)+2);
                *pos++ = WLAN_EID_HT_CAPABILITY;
                *pos++ = sizeof(struct ieee80211_ht_cap);
                memset(pos, 0, sizeof(struct ieee80211_ht_cap));
                memcpy(pos, &tmp, sizeof(u16));
                pos += sizeof(u16);
                /* TODO: needs a define here for << 2 */
                *pos++ = sband->ht_cap.ampdu_factor |
                         (sband->ht_cap.ampdu_density << 2);
                memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
        }

        ieee80211_tx_skb(sdata, skb, 0);
}


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

        skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt));
        if (!skb) {
                printk(KERN_DEBUG "%s: failed to allocate buffer for "
                       "deauth/disassoc frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);

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

        if (stype == IEEE80211_STYPE_DEAUTH)
                cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len, cookie);
        else
                cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len, cookie);
        ieee80211_tx_skb(sdata, skb, ifmgd->flags & IEEE80211_STA_MFP_ENABLED);
}

void ieee80211_send_pspoll(struct ieee80211_local *local,
                           struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_pspoll *pspoll;
        struct sk_buff *skb;
        u16 fc;

        skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
        if (!skb) {
                printk(KERN_DEBUG "%s: failed to allocate buffer for "
                       "pspoll frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);

        pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
        memset(pspoll, 0, sizeof(*pspoll));
        fc = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_PSPOLL | IEEE80211_FCTL_PM;
        pspoll->frame_control = cpu_to_le16(fc);
        pspoll->aid = cpu_to_le16(ifmgd->aid);

        /* aid in PS-Poll has its two MSBs each set to 1 */
        pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);

        memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
        memcpy(pspoll->ta, sdata->dev->dev_addr, ETH_ALEN);

        ieee80211_tx_skb(sdata, skb, 0);
}

void ieee80211_send_nullfunc(struct ieee80211_local *local,
                             struct ieee80211_sub_if_data *sdata,
                             int powersave)
{
        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 + 24);
        if (!skb) {
                printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
                       "frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);

        nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24);
        memset(nullfunc, 0, 24);
        fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC |
                         IEEE80211_FCTL_TODS);
        if (powersave)
                fc |= cpu_to_le16(IEEE80211_FCTL_PM);
        nullfunc->frame_control = fc;
        memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN);
        memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN);
        memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN);

        ieee80211_tx_skb(sdata, skb, 0);
}

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

        if (!netif_running(sdata->dev))
                return;

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

        sdata->local->oper_channel = sdata->local->csa_channel;
        ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_CHANNEL);

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

        ieee80211_wake_queues_by_reason(&sdata->local->hw,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);
 out:
        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
        mutex_unlock(&ifmgd->mtx);
}

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

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

        queue_work(sdata->local->hw.workqueue, &ifmgd->chswitch_work);
}

void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                      struct ieee80211_channel_sw_ie *sw_elem,
                                      struct ieee80211_bss *bss)
{
        struct ieee80211_channel *new_ch;
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num);

        ASSERT_MGD_MTX(ifmgd);

        if (!ifmgd->associated)
                return;

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

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

        if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                return;

        new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED)
                return;

        sdata->local->csa_channel = new_ch;

        if (sw_elem->count <= 1) {
                queue_work(sdata->local->hw.workqueue, &ifmgd->chswitch_work);
        } else {
                ieee80211_stop_queues_by_reason(&sdata->local->hw,
                                        IEEE80211_QUEUE_STOP_REASON_CSA);
                ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
                mod_timer(&ifmgd->chswitch_timer,
                          jiffies +
                          msecs_to_jiffies(sw_elem->count *
                                           bss->cbss.beacon_interval));
        }
}

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

        if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
                return;

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

        if ((*pwr_constr_elem <= conf->channel->max_power) &&
            (*pwr_constr_elem != sdata->local->power_constr_level)) {
                sdata->local->power_constr_level = *pwr_constr_elem;
                ieee80211_hw_config(sdata->local, 0);
        }
}

/* 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);
                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);
        }
}

/* 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;

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

        list_for_each_entry(sdata, &local->interfaces, list) {
                if (!netif_running(sdata->dev))
                        continue;
                if (sdata->vif.type != NL80211_IFTYPE_STATION)
                        continue;
                found = sdata;
                count++;
        }

        if (count == 1 && found->u.mgd.powersave &&
            found->u.mgd.associated && list_empty(&found->u.mgd.work_list) &&
            !(found->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
                                    IEEE80211_STA_CONNECTION_POLL))) {
                s32 beaconint_us;

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

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

                if (beaconint_us > latency) {
                        local->ps_sdata = NULL;
                } else {
                        u8 dtimper = found->vif.bss_conf.dtim_period;
                        int maxslp = 1;

                        if (dtimper > 1)
                                maxslp = min_t(int, dtimper,
                                                    latency / beaconint_us);

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

        ieee80211_change_ps(local);
}

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

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

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

void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
{
        struct ieee80211_local *local =
                container_of(work, struct ieee80211_local,
                             dynamic_ps_enable_work);
        struct ieee80211_sub_if_data *sdata = local->ps_sdata;

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

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

        if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
                ieee80211_send_nullfunc(local, sdata, 1);

        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)
                return;

        queue_work(local->hw.workqueue, &local->dynamic_ps_enable_work);
}

/* MLME */
static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
                                     struct ieee80211_if_managed *ifmgd,
                                     u8 *wmm_param, size_t wmm_param_len)
{
        struct ieee80211_tx_queue_params params;
        size_t left;
        int count;
        u8 *pos;

        if (!(ifmgd->flags & IEEE80211_STA_WMM_ENABLED))
                return;

        if (!wmm_param)
                return;

        if (wmm_param_len < 8 || wmm_param[5] /* version */ != 1)
                return;
        count = wmm_param[6] & 0x0f;
        if (count == ifmgd->wmm_last_param_set)
                return;
        ifmgd->wmm_last_param_set = count;

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

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

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

                switch (aci) {
                case 1: /* AC_BK */
                        queue = 3;
                        if (acm)
                                local->wmm_acm |= BIT(1) | BIT(2); /* BK/- */
                        break;
                case 2: /* AC_VI */
                        queue = 1;
                        if (acm)
                                local->wmm_acm |= BIT(4) | BIT(5); /* CL/VI */
                        break;
                case 3: /* AC_VO */
                        queue = 0;
                        if (acm)
                                local->wmm_acm |= BIT(6) | BIT(7); /* VO/NC */
                        break;
                case 0: /* AC_BE */
                default:
                        queue = 2;
                        if (acm)
                                local->wmm_acm |= BIT(0) | BIT(3); /* BE/EE */
                        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);
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                printk(KERN_DEBUG "%s: WMM queue=%d aci=%d acm=%d aifs=%d "
                       "cWmin=%d cWmax=%d txop=%d\n",
                       wiphy_name(local->hw.wiphy), queue, aci, acm,
                       params.aifs, params.cw_min, params.cw_max, params.txop);
#endif
                if (drv_conf_tx(local, queue, &params) && local->ops->conf_tx)
                        printk(KERN_DEBUG "%s: failed to set TX queue "
                               "parameters for queue %d\n",
                               wiphy_name(local->hw.wiphy), queue);
        }
}

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 (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 ieee80211_bss *bss,
                                     u32 bss_info_changed)
{
        struct ieee80211_local *local = sdata->local;

        bss_info_changed |= BSS_CHANGED_ASSOC;
        /* set timing information */
        sdata->vif.bss_conf.beacon_int = bss->cbss.beacon_interval;
        sdata->vif.bss_conf.timestamp = bss->cbss.tsf;
        sdata->vif.bss_conf.dtim_period = bss->dtim_period;

        bss_info_changed |= BSS_CHANGED_BEACON_INT;
        bss_info_changed |= ieee80211_handle_bss_capability(sdata,
                bss->cbss.capability, bss->has_erp_value, bss->erp_value);

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

        /* just to be sure */
        sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                                IEEE80211_STA_BEACON_POLL);

        ieee80211_led_assoc(local, 1);

        sdata->vif.bss_conf.assoc = 1;
        /*
         * For now just always ask the driver to update the basic rateset
         * when we have associated, we aren't checking whether it actually
         * changed or not.
         */
        bss_info_changed |= BSS_CHANGED_BASIC_RATES;

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

        ieee80211_bss_info_change_notify(sdata, bss_info_changed);

        /* will be same as sdata */
        if (local->ps_sdata) {
                mutex_lock(&local->iflist_mtx);
                ieee80211_recalc_ps(local, -1);
                mutex_unlock(&local->iflist_mtx);
        }

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

static enum rx_mgmt_action __must_check
ieee80211_direct_probe(struct ieee80211_sub_if_data *sdata,
                       struct ieee80211_mgd_work *wk)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;

        wk->tries++;
        if (wk->tries > IEEE80211_AUTH_MAX_TRIES) {
                printk(KERN_DEBUG "%s: direct probe to AP %pM timed out\n",
                       sdata->dev->name, wk->bss->cbss.bssid);

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

                /*
                 * We might have a pending scan which had no chance to run yet
                 * due to work needing to be done. Hence, queue the STAs work
                 * again for that.
                 */
                queue_work(local->hw.workqueue, &ifmgd->work);
                return RX_MGMT_CFG80211_AUTH_TO;
        }

        printk(KERN_DEBUG "%s: direct probe to AP %pM (try %d)\n",
                        sdata->dev->name, wk->bss->cbss.bssid,
                        wk->tries);

        /*
         * Direct probe is sent to broadcast address as some APs
         * will not answer to direct packet in unassociated state.
         */
        ieee80211_send_probe_req(sdata, NULL, wk->ssid, wk->ssid_len, NULL, 0);

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

        return RX_MGMT_NONE;
}


static enum rx_mgmt_action __must_check
ieee80211_authenticate(struct ieee80211_sub_if_data *sdata,
                       struct ieee80211_mgd_work *wk)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;

        wk->tries++;
        if (wk->tries > IEEE80211_AUTH_MAX_TRIES) {
                printk(KERN_DEBUG "%s: authentication with AP %pM"
                       " timed out\n",
                       sdata->dev->name, wk->bss->cbss.bssid);

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

                /*
                 * We might have a pending scan which had no chance to run yet
                 * due to work needing to be done. Hence, queue the STAs work
                 * again for that.
                 */
                queue_work(local->hw.workqueue, &ifmgd->work);
                return RX_MGMT_CFG80211_AUTH_TO;
        }

        printk(KERN_DEBUG "%s: authenticate with AP %pM (try %d)\n",
               sdata->dev->name, wk->bss->cbss.bssid, wk->tries);

        ieee80211_send_auth(sdata, 1, wk->auth_alg, wk->ie, wk->ie_len,
                            wk->bss->cbss.bssid, NULL, 0, 0);
        wk->auth_transaction = 2;

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

        return RX_MGMT_NONE;
}

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

        ASSERT_MGD_MTX(ifmgd);

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

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

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

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

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

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

        rcu_read_lock();
        sta = sta_info_get(local, bssid);
        if (sta)
                ieee80211_sta_tear_down_BA_sessions(sta);
        rcu_read_unlock();

        changed |= ieee80211_reset_erp_info(sdata);

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

        ieee80211_set_wmm_default(sdata);

        ieee80211_recalc_idle(local);

        /* channel(_type) changes are handled by ieee80211_hw_config */
        local->oper_channel_type = NL80211_CHAN_NO_HT;

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

        local->power_constr_level = 0;

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

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

        ieee80211_hw_config(local, config_changed);

        /* And the BSSID changed -- not very interesting here */
        changed |= BSS_CHANGED_BSSID;
        ieee80211_bss_info_change_notify(sdata, changed);

        rcu_read_lock();

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

        sta_info_unlink(&sta);

        rcu_read_unlock();

        sta_info_destroy(sta);
}

static enum rx_mgmt_action __must_check
ieee80211_associate(struct ieee80211_sub_if_data *sdata,
                    struct ieee80211_mgd_work *wk)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;

        wk->tries++;
        if (wk->tries > IEEE80211_ASSOC_MAX_TRIES) {
                printk(KERN_DEBUG "%s: association with AP %pM"
                       " timed out\n",
                       sdata->dev->name, wk->bss->cbss.bssid);

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

                /*
                 * We might have a pending scan which had no chance to run yet
                 * due to work needing to be done. Hence, queue the STAs work
                 * again for that.
                 */
                queue_work(local->hw.workqueue, &ifmgd->work);
                return RX_MGMT_CFG80211_ASSOC_TO;
        }

        printk(KERN_DEBUG "%s: associate with AP %pM (try %d)\n",
               sdata->dev->name, wk->bss->cbss.bssid, wk->tries);
        ieee80211_send_assoc(sdata, wk);

        wk->timeout = jiffies + IEEE80211_ASSOC_TIMEOUT;
        run_again(ifmgd, wk->timeout);

        return RX_MGMT_NONE;
}

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;

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

static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
                                   bool beacon)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        const u8 *ssid;
        bool already = false;

        if (!netif_running(sdata->dev))
                return;

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

        mutex_lock(&ifmgd->mtx);

        if (!ifmgd->associated)
                goto out;

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

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

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

        if (already)
                goto out;

        ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT;

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

        ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
        ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
                                 ssid + 2, ssid[1], NULL, 0);

        run_again(ifmgd, ifmgd->probe_timeout);

 out:
        mutex_unlock(&ifmgd->mtx);
}

void ieee80211_beacon_loss_work(struct work_struct *work)
{
        struct ieee80211_sub_if_data *sdata =
                container_of(work, struct ieee80211_sub_if_data,
                             u.mgd.beacon_loss_work);

        ieee80211_mgd_probe_ap(sdata, true);
}

void ieee80211_beacon_loss(struct ieee80211_vif *vif)
{
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

        queue_work(sdata->local->hw.workqueue,
                   &sdata->u.mgd.beacon_loss_work);
}
EXPORT_SYMBOL(ieee80211_beacon_loss);

static void ieee80211_auth_completed(struct ieee80211_sub_if_data *sdata,
                                     struct ieee80211_mgd_work *wk)
{
        wk->state = IEEE80211_MGD_STATE_IDLE;
        printk(KERN_DEBUG "%s: authenticated\n", sdata->dev->name);
}


static void ieee80211_auth_challenge(struct ieee80211_sub_if_data *sdata,
                                     struct ieee80211_mgd_work *wk,
                                     struct ieee80211_mgmt *mgmt,
                                     size_t len)
{
        u8 *pos;
        struct ieee802_11_elems elems;

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

static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata,
                       struct ieee80211_mgd_work *wk,
                       struct ieee80211_mgmt *mgmt, size_t len)
{
        u16 auth_alg, auth_transaction, status_code;

        if (wk->state != IEEE80211_MGD_STATE_AUTH)
                return RX_MGMT_NONE;

        if (len < 24 + 6)
                return RX_MGMT_NONE;

        if (memcmp(wk->bss->cbss.bssid, mgmt->sa, ETH_ALEN) != 0)
                return RX_MGMT_NONE;

        if (memcmp(wk->bss->cbss.bssid, mgmt->bssid, ETH_ALEN) != 0)
                return RX_MGMT_NONE;

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

        if (auth_alg != wk->auth_alg ||
            auth_transaction != wk->auth_transaction)
                return RX_MGMT_NONE;

        if (status_code != WLAN_STATUS_SUCCESS) {
                list_del(&wk->list);
                kfree(wk);
                return RX_MGMT_CFG80211_AUTH;
        }

        switch (wk->auth_alg) {
        case WLAN_AUTH_OPEN:
        case WLAN_AUTH_LEAP:
        case WLAN_AUTH_FT:
                ieee80211_auth_completed(sdata, wk);
                return RX_MGMT_CFG80211_AUTH;
        case WLAN_AUTH_SHARED_KEY:
                if (wk->auth_transaction == 4) {
                        ieee80211_auth_completed(sdata, wk);
                        return RX_MGMT_CFG80211_AUTH;
                } else
                        ieee80211_auth_challenge(sdata, wk, mgmt, len);
                break;
        }

        return RX_MGMT_NONE;
}


static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata,
                         struct ieee80211_mgd_work *wk,
                         struct ieee80211_mgmt *mgmt, size_t len)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        const u8 *bssid = NULL;
        u16 reason_code;

        if (len < 24 + 2)
                return RX_MGMT_NONE;

        ASSERT_MGD_MTX(ifmgd);

        if (wk)
                bssid = wk->bss->cbss.bssid;
        else
                bssid = ifmgd->associated->cbss.bssid;

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

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

        if (!wk) {
                ieee80211_set_disassoc(sdata);
        } else {
                list_del(&wk->list);
                kfree(wk);
        }

        return RX_MGMT_CFG80211_DEAUTH;
}


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

        if (len < 24 + 2)
                return RX_MGMT_NONE;

        ASSERT_MGD_MTX(ifmgd);

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

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

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

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

        ieee80211_set_disassoc(sdata);
        return RX_MGMT_CFG80211_DISASSOC;
}


static enum rx_mgmt_action __must_check
ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
                             struct ieee80211_mgd_work *wk,
                             struct ieee80211_mgmt *mgmt, size_t len,
                             bool reassoc)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        struct sta_info *sta;
        u32 rates, basic_rates;
        u16 capab_info, status_code, aid;
        struct ieee802_11_elems elems;
        struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
        u8 *pos;
        u32 changed = 0;
        int i, j;
        bool have_higher_than_11mbit = false, newsta = false;
        u16 ap_ht_cap_flags;

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

        if (len < 24 + 6)
                return RX_MGMT_NONE;

        if (memcmp(wk->bss->cbss.bssid, mgmt->sa, ETH_ALEN) != 0)
                return RX_MGMT_NONE;

        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);

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

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

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

        if (status_code != WLAN_STATUS_SUCCESS) {
                printk(KERN_DEBUG "%s: AP denied association (code=%d)\n",
                       sdata->dev->name, status_code);
                list_del(&wk->list);
                kfree(wk);
                return RX_MGMT_CFG80211_ASSOC;
        }

        if ((aid & (BIT(15) | BIT(14))) != (BIT(15) | BIT(14)))
                printk(KERN_DEBUG "%s: invalid aid value %d; bits 15:14 not "
                       "set\n", sdata->dev->name, aid);
        aid &= ~(BIT(15) | BIT(14));

        if (!elems.supp_rates) {
                printk(KERN_DEBUG "%s: no SuppRates element in AssocResp\n",
                       sdata->dev->name);
                return RX_MGMT_NONE;
        }

        printk(KERN_DEBUG "%s: associated\n", sdata->dev->name);
        ifmgd->aid = aid;

        rcu_read_lock();

        /* Add STA entry for the AP */
        sta = sta_info_get(local, wk->bss->cbss.bssid);
        if (!sta) {
                newsta = true;

                rcu_read_unlock();

                sta = sta_info_alloc(sdata, wk->bss->cbss.bssid, GFP_KERNEL);
                if (!sta) {
                        printk(KERN_DEBUG "%s: failed to alloc STA entry for"
                               " the AP\n", sdata->dev->name);
                        return RX_MGMT_NONE;
                }

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

                rcu_read_lock();
        }

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

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

                if (rate > 110)
                        have_higher_than_11mbit = true;

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

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

                if (rate > 110)
                        have_higher_than_11mbit = true;

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

        sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
        sdata->vif.bss_conf.basic_rates = basic_rates;

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

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

        ap_ht_cap_flags = sta->sta.ht_cap.cap;

        rate_control_rate_init(sta);

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

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

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

        rcu_read_unlock();

        if (elems.wmm_param)
                ieee80211_sta_wmm_params(local, ifmgd, elems.wmm_param,
                                         elems.wmm_param_len);
        else
                ieee80211_set_wmm_default(sdata);

        if (elems.ht_info_elem && elems.wmm_param &&
            (ifmgd->flags & IEEE80211_STA_WMM_ENABLED) &&
            !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                changed |= ieee80211_enable_ht(sdata, elems.ht_info_elem,
                                               wk->bss->cbss.bssid,
                                               ap_ht_cap_flags);

        /* 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, wk->bss, changed);

        /*
         * 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);
        mod_beacon_timer(sdata);

        list_del(&wk->list);
        kfree(wk);
        return RX_MGMT_CFG80211_ASSOC;
}


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

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

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

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

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

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

        if (elems->ch_switch_elem && (elems->ch_switch_elem_len == 3) &&
            (memcmp(mgmt->bssid, sdata->u.mgd.associated->cbss.bssid,
                                                        ETH_ALEN) == 0)) {
                struct ieee80211_channel_sw_ie *sw_elem =
                        (struct ieee80211_channel_sw_ie *)elems->ch_switch_elem;
                ieee80211_sta_process_chanswitch(sdata, sw_elem, bss);
        }
}


static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
                                         struct ieee80211_mgd_work *wk,
                                         struct ieee80211_mgmt *mgmt, size_t len,
                                         struct ieee80211_rx_status *rx_status)
{
        struct ieee80211_if_managed *ifmgd;
        size_t baselen;
        struct ieee802_11_elems elems;

        ifmgd = &sdata->u.mgd;

        ASSERT_MGD_MTX(ifmgd);

        if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
                return; /* ignore ProbeResp to foreign address */

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

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

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

        /* direct probe may be part of the association flow */
        if (wk && wk->state == IEEE80211_MGD_STATE_PROBE) {
                printk(KERN_DEBUG "%s direct probe responded\n",
                       sdata->dev->name);
                wk->tries = 0;
                wk->state = IEEE80211_MGD_STATE_AUTH;
                WARN_ON(ieee80211_authenticate(sdata, wk) != RX_MGMT_NONE);
        }

        if (ifmgd->associated &&
            memcmp(mgmt->bssid, ifmgd->associated->cbss.bssid, ETH_ALEN) == 0 &&
            ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                            IEEE80211_STA_CONNECTION_POLL)) {
                ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                                  IEEE80211_STA_BEACON_POLL);
                mutex_lock(&sdata->local->iflist_mtx);
                ieee80211_recalc_ps(sdata->local, -1);
                mutex_unlock(&sdata->local->iflist_mtx);
                /*
                 * 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.
                 */
                mod_beacon_timer(sdata);
                mod_timer(&ifmgd->conn_mon_timer,
                          round_jiffies_up(jiffies +
                                           IEEE80211_CONNECTION_IDLE_TIME));
        }
}

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

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

        ASSERT_MGD_MTX(ifmgd);

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

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

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

        bssid = ifmgd->associated->cbss.bssid;

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

        if (ifmgd->flags & IEEE80211_STA_BEACON_POLL) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                if (net_ratelimit()) {
                        printk(KERN_DEBUG "%s: cancelling probereq poll due "
                               "to a received beacon\n", sdata->dev->name);
                }
#endif
                ifmgd->flags &= ~IEEE80211_STA_BEACON_POLL;
                mutex_lock(&local->iflist_mtx);
                ieee80211_recalc_ps(local, -1);
                mutex_unlock(&local->iflist_mtx);
        }

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

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

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

        if (ncrc != ifmgd->beacon_crc) {
                ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems,
                                      true);

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

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

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

        if (ncrc == ifmgd->beacon_crc)
                return;
        ifmgd->beacon_crc = ncrc;

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


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

                rcu_read_lock();

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

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

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

                ap_ht_cap_flags = sta->sta.ht_cap.cap;

                rcu_read_unlock();

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

        if (elems.country_elem) {
                /* Note we are only reviewing this on beacons
                 * for the BSSID we are associated to */
                regulatory_hint_11d(local->hw.wiphy,
                        elems.country_elem, elems.country_elem_len);

                /* TODO: IBSS also needs this */
                if (elems.pwr_constr_elem)
                        ieee80211_handle_pwr_constr(sdata,
                                le16_to_cpu(mgmt->u.probe_resp.capab_info),
                                elems.pwr_constr_elem,
                                elems.pwr_constr_elem_len);
        }

        ieee80211_bss_info_change_notify(sdata, changed);
}

ieee80211_rx_result ieee80211_sta_rx_mgmt(struct ieee80211_sub_if_data *sdata,
                                          struct sk_buff *skb)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_mgmt *mgmt;
        u16 fc;

        if (skb->len < 24)
                return RX_DROP_MONITOR;

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

        switch (fc & IEEE80211_FCTL_STYPE) {
        case IEEE80211_STYPE_PROBE_REQ:
        case IEEE80211_STYPE_PROBE_RESP:
        case IEEE80211_STYPE_BEACON:
        case IEEE80211_STYPE_AUTH:
        case IEEE80211_STYPE_ASSOC_RESP:
        case IEEE80211_STYPE_REASSOC_RESP:
        case IEEE80211_STYPE_DEAUTH:
        case IEEE80211_STYPE_DISASSOC:
        case IEEE80211_STYPE_ACTION:
                skb_queue_tail(&sdata->u.mgd.skb_queue, skb);
                queue_work(local->hw.workqueue, &sdata->u.mgd.work);
                return RX_QUEUED;
        }

        return RX_DROP_MONITOR;
}

static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
                                         struct sk_buff *skb)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_rx_status *rx_status;
        struct ieee80211_mgmt *mgmt;
        struct ieee80211_mgd_work *wk;
        enum rx_mgmt_action rma = RX_MGMT_NONE;
        u16 fc;

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

        mutex_lock(&ifmgd->mtx);

        if (ifmgd->associated &&
            memcmp(ifmgd->associated->cbss.bssid, mgmt->bssid,
                                                        ETH_ALEN) == 0) {
                switch (fc & IEEE80211_FCTL_STYPE) {
                case IEEE80211_STYPE_BEACON:
                        ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
                                                 rx_status);
                        break;
                case IEEE80211_STYPE_PROBE_RESP:
                        ieee80211_rx_mgmt_probe_resp(sdata, NULL, mgmt,
                                                     skb->len, rx_status);
                        break;
                case IEEE80211_STYPE_DEAUTH:
                        rma = ieee80211_rx_mgmt_deauth(sdata, NULL,
                                                       mgmt, skb->len);
                        break;
                case IEEE80211_STYPE_DISASSOC:
                        rma = ieee80211_rx_mgmt_disassoc(sdata, mgmt, skb->len);
                        break;
                case IEEE80211_STYPE_ACTION:
                        /* XXX: differentiate, can only happen for CSA now! */
                        ieee80211_sta_process_chanswitch(sdata,
                                        &mgmt->u.action.u.chan_switch.sw_elem,
                                        ifmgd->associated);
                        break;
                }
                mutex_unlock(&ifmgd->mtx);

                switch (rma) {
                case RX_MGMT_NONE:
                        /* no action */
                        break;
                case RX_MGMT_CFG80211_DEAUTH:
                        cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len,
                                             NULL);
                        break;
                case RX_MGMT_CFG80211_DISASSOC:
                        cfg80211_send_disassoc(sdata->dev, (u8 *)mgmt, skb->len,
                                               NULL);
                        break;
                default:
                        WARN(1, "unexpected: %d", rma);
                }
                goto out;
        }

        list_for_each_entry(wk, &ifmgd->work_list, list) {
                if (memcmp(wk->bss->cbss.bssid, mgmt->bssid, ETH_ALEN) != 0)
                        continue;

                switch (fc & IEEE80211_FCTL_STYPE) {
                case IEEE80211_STYPE_PROBE_RESP:
                        ieee80211_rx_mgmt_probe_resp(sdata, wk, mgmt, skb->len,
                                                     rx_status);
                        break;
                case IEEE80211_STYPE_AUTH:
                        rma = ieee80211_rx_mgmt_auth(sdata, wk, mgmt, skb->len);
                        break;
                case IEEE80211_STYPE_ASSOC_RESP:
                        rma = ieee80211_rx_mgmt_assoc_resp(sdata, wk, mgmt,
                                                           skb->len, false);
                        break;
                case IEEE80211_STYPE_REASSOC_RESP:
                        rma = ieee80211_rx_mgmt_assoc_resp(sdata, wk, mgmt,
                                                           skb->len, true);
                        break;
                case IEEE80211_STYPE_DEAUTH:
                        rma = ieee80211_rx_mgmt_deauth(sdata, wk, mgmt,
                                                       skb->len);
                        break;
                }
                /*
                 * We've processed this frame for that work, so it can't
                 * belong to another work struct.
                 * NB: this is also required for correctness because the
                 * called functions can free 'wk', and for 'rma'!
                 */
                break;
        }

        mutex_unlock(&ifmgd->mtx);

        switch (rma) {
        case RX_MGMT_NONE:
                /* no action */
                break;
        case RX_MGMT_CFG80211_AUTH:
                cfg80211_send_rx_auth(sdata->dev, (u8 *) mgmt, skb->len);
                break;
        case RX_MGMT_CFG80211_ASSOC:
                cfg80211_send_rx_assoc(sdata->dev, (u8 *) mgmt, skb->len);
                break;
        default:
                WARN(1, "unexpected: %d", rma);
        }

 out:
        kfree_skb(skb);
}

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

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

        queue_work(local->hw.workqueue, &ifmgd->work);
}

static void ieee80211_sta_work(struct work_struct *work)
{
        struct ieee80211_sub_if_data *sdata =
                container_of(work, struct ieee80211_sub_if_data, u.mgd.work);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_managed *ifmgd;
        struct sk_buff *skb;
        struct ieee80211_mgd_work *wk, *tmp;
        LIST_HEAD(free_work);
        enum rx_mgmt_action rma;
        bool anybusy = false;

        if (!netif_running(sdata->dev))
                return;

        if (local->scanning)
                return;

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

        /*
         * Nothing should have been stuffed into the workqueue during
         * the suspend->resume cycle. If this WARN is seen then there
         * is a bug with either the driver suspend or something in
         * mac80211 stuffing into the workqueue which we haven't yet
         * cleared during mac80211's suspend cycle.
         */
        if (WARN_ON(local->suspended))
                return;

        ifmgd = &sdata->u.mgd;

        /* first process frames to avoid timing out while a frame is pending */
        while ((skb = skb_dequeue(&ifmgd->skb_queue)))
                ieee80211_sta_rx_queued_mgmt(sdata, skb);

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

        if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                            IEEE80211_STA_CONNECTION_POLL) &&
            ifmgd->associated) {
                if (time_is_after_jiffies(ifmgd->probe_timeout))
                        run_again(ifmgd, ifmgd->probe_timeout);
                else {
                        u8 bssid[ETH_ALEN];
                        /*
                         * We actually lost the connection ... or did we?
                         * Let's make sure!
                         */
                        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                                          IEEE80211_STA_BEACON_POLL);
                        memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
                        printk(KERN_DEBUG "No probe response from AP %pM"
                                " after %dms, disconnecting.\n",
                                bssid, (1000 * IEEE80211_PROBE_WAIT)/HZ);
                        ieee80211_set_disassoc(sdata);
                        mutex_unlock(&ifmgd->mtx);
                        /*
                         * must be outside lock due to cfg80211,
                         * but that's not a problem.
                         */
                        ieee80211_send_deauth_disassoc(sdata, bssid,
                                        IEEE80211_STYPE_DEAUTH,
                                        WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY,
                                        NULL);
                        mutex_lock(&ifmgd->mtx);
                }
        }

        list_for_each_entry(wk, &ifmgd->work_list, list) {
                if (wk->state != IEEE80211_MGD_STATE_IDLE) {
                        anybusy = true;
                        break;
                }
        }

        ieee80211_recalc_idle(local);

        if (!anybusy) {
                mutex_unlock(&ifmgd->mtx);

                if (test_and_clear_bit(IEEE80211_STA_REQ_SCAN, &ifmgd->request))
                        queue_delayed_work(local->hw.workqueue,
                                           &local->scan_work,
                                           round_jiffies_relative(0));
                return;
        }

        list_for_each_entry_safe(wk, tmp, &ifmgd->work_list, list) {
                if (time_is_after_jiffies(wk->timeout)) {
                        /*
                         * This work item isn't supposed to be worked on
                         * right now, but take care to adjust the timer
                         * properly.
                         */
                        run_again(ifmgd, wk->timeout);
                        continue;
                }

                switch (wk->state) {
                default:
                        WARN_ON(1);
                        /* fall through */
                case IEEE80211_MGD_STATE_IDLE:
                        /* nothing */
                        rma = RX_MGMT_NONE;
                        break;
                case IEEE80211_MGD_STATE_PROBE:
                        rma = ieee80211_direct_probe(sdata, wk);
                        break;
                case IEEE80211_MGD_STATE_AUTH:
                        rma = ieee80211_authenticate(sdata, wk);
                        break;
                case IEEE80211_MGD_STATE_ASSOC:
                        rma = ieee80211_associate(sdata, wk);
                        break;
                }

                switch (rma) {
                case RX_MGMT_NONE:
                        /* no action required */
                        break;
                case RX_MGMT_CFG80211_AUTH_TO:
                case RX_MGMT_CFG80211_ASSOC_TO:
                        list_del(&wk->list);
                        list_add(&wk->list, &free_work);
                        wk->tries = rma; /* small abuse but only local */
                        break;
                default:
                        WARN(1, "unexpected: %d", rma);
                }
        }

        mutex_unlock(&ifmgd->mtx);

        list_for_each_entry_safe(wk, tmp, &free_work, list) {
                switch (wk->tries) {
                case RX_MGMT_CFG80211_AUTH_TO:
                        cfg80211_send_auth_timeout(sdata->dev,
                                                   wk->bss->cbss.bssid);
                        break;
                case RX_MGMT_CFG80211_ASSOC_TO:
                        cfg80211_send_assoc_timeout(sdata->dev,
                                                    wk->bss->cbss.bssid);
                        break;
                default:
                        WARN(1, "unexpected: %d", wk->tries);
                }

                list_del(&wk->list);
                kfree(wk);
        }

        ieee80211_recalc_idle(local);
}

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

        if (local->quiescing)
                return;

        queue_work(sdata->local->hw.workqueue,
                   &sdata->u.mgd.beacon_loss_work);
}

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

        if (local->quiescing)
                return;

        queue_work(local->hw.workqueue, &ifmgd->monitor_work);
}

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

        ieee80211_mgd_probe_ap(sdata, false);
}

static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
{
        if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                sdata->u.mgd.flags &= ~(IEEE80211_STA_BEACON_POLL |
                                        IEEE80211_STA_CONNECTION_POLL);

                /* let's probe the connection once */
                queue_work(sdata->local->hw.workqueue,
                           &sdata->u.mgd.monitor_work);
                /* and do all the other regular work too */
                queue_work(sdata->local->hw.workqueue,
                           &sdata->u.mgd.work);
        }
}

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

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

        cancel_work_sync(&ifmgd->work);
        cancel_work_sync(&ifmgd->beacon_loss_work);
        if (del_timer_sync(&ifmgd->timer))
                set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);

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

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

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

        if (test_and_clear_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running))
                add_timer(&ifmgd->timer);
        if (test_and_clear_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running))
                add_timer(&ifmgd->chswitch_timer);
}
#endif

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

        ifmgd = &sdata->u.mgd;
        INIT_WORK(&ifmgd->work, ieee80211_sta_work);
        INIT_WORK(&ifmgd->monitor_work, ieee80211_sta_monitor_work);
        INIT_WORK(&ifmgd->chswitch_work, ieee80211_chswitch_work);
        INIT_WORK(&ifmgd->beacon_loss_work, ieee80211_beacon_loss_work);
        setup_timer(&ifmgd->timer, ieee80211_sta_timer,
                    (unsigned long) sdata);
        setup_timer(&ifmgd->bcn_mon_timer, ieee80211_sta_bcn_mon_timer,
                    (unsigned long) sdata);
        setup_timer(&ifmgd->conn_mon_timer, ieee80211_sta_conn_mon_timer,
                    (unsigned long) sdata);
        setup_timer(&ifmgd->chswitch_timer, ieee80211_chswitch_timer,
                    (unsigned long) sdata);
        skb_queue_head_init(&ifmgd->skb_queue);

        INIT_LIST_HEAD(&ifmgd->work_list);

        ifmgd->capab = WLAN_CAPABILITY_ESS;
        ifmgd->flags = 0;
        if (sdata->local->hw.queues >= 4)
                ifmgd->flags |= IEEE80211_STA_WMM_ENABLED;

        mutex_init(&ifmgd->mtx);
}

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

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

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

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

        return 0;
}

/* config hooks */
int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
                       struct cfg80211_auth_request *req)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        const u8 *ssid;
        struct ieee80211_mgd_work *wk;
        u16 auth_alg;

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

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

        wk->bss = (void *)req->bss;

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

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

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

        wk->state = IEEE80211_MGD_STATE_PROBE;
        wk->auth_alg = auth_alg;
        wk->timeout = jiffies; /* run right away */

        /*
         * XXX: if still associated need to tell AP that we're going
         *      to sleep and then change channel etc.
         */
        sdata->local->oper_channel = req->bss->channel;
        ieee80211_hw_config(sdata->local, 0);

        mutex_lock(&ifmgd->mtx);
        list_add(&wk->list, &sdata->u.mgd.work_list);
        mutex_unlock(&ifmgd->mtx);

        queue_work(sdata->local->hw.workqueue, &sdata->u.mgd.work);
        return 0;
}

int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
                        struct cfg80211_assoc_request *req)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_mgd_work *wk, *found = NULL;
        int i, err;

        mutex_lock(&ifmgd->mtx);

        list_for_each_entry(wk, &ifmgd->work_list, list) {
                if (&wk->bss->cbss == req->bss &&
                    wk->state == IEEE80211_MGD_STATE_IDLE) {
                        found = wk;
                        break;
                }
        }

        if (!found) {
                err = -ENOLINK;
                goto out;
        }

        list_del(&found->list);

        wk = krealloc(found, sizeof(*wk) + req->ie_len, GFP_KERNEL);
        if (!wk) {
                list_add(&found->list, &ifmgd->work_list);
                err = -ENOMEM;
                goto out;
        }

        list_add(&wk->list, &ifmgd->work_list);

        ifmgd->flags &= ~IEEE80211_STA_DISABLE_11N;

        for (i = 0; i < req->crypto.n_ciphers_pairwise; i++)
                if (req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_WEP40 ||
                    req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_TKIP ||
                    req->crypto.ciphers_pairwise[i] == WLAN_CIPHER_SUITE_WEP104)
                        ifmgd->flags |= IEEE80211_STA_DISABLE_11N;

        sdata->local->oper_channel = req->bss->channel;
        ieee80211_hw_config(sdata->local, 0);

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

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

        wk->state = IEEE80211_MGD_STATE_ASSOC;
        wk->tries = 0;
        wk->timeout = jiffies; /* run right away */

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

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

        queue_work(sdata->local->hw.workqueue, &sdata->u.mgd.work);

        err = 0;

 out:
        mutex_unlock(&ifmgd->mtx);
        return err;
}

int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
                         struct cfg80211_deauth_request *req,
                         void *cookie)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
        struct ieee80211_mgd_work *wk;
        const u8 *bssid = NULL;

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

        mutex_lock(&ifmgd->mtx);

        if (ifmgd->associated && &ifmgd->associated->cbss == req->bss) {
                bssid = req->bss->bssid;
                ieee80211_set_disassoc(sdata);
        } else list_for_each_entry(wk, &ifmgd->work_list, list) {
                if (&wk->bss->cbss == req->bss) {
                        bssid = req->bss->bssid;
                        list_del(&wk->list);
                        kfree(wk);
                        break;
                }
        }

        /* cfg80211 should catch this... */
        if (WARN_ON(!bssid)) {
                mutex_unlock(&ifmgd->mtx);
                return -ENOLINK;
        }

        mutex_unlock(&ifmgd->mtx);

        ieee80211_send_deauth_disassoc(sdata, bssid,
                        IEEE80211_STYPE_DEAUTH, req->reason_code,
                        cookie);

        return 0;
}

int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
                           struct cfg80211_disassoc_request *req,
                           void *cookie)
{
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

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

        mutex_lock(&ifmgd->mtx);

        /* cfg80211 should catch that */
        if (WARN_ON(&ifmgd->associated->cbss != req->bss)) {
                mutex_unlock(&ifmgd->mtx);
                return -ENOLINK;
        }

        ieee80211_set_disassoc(sdata);

        mutex_unlock(&ifmgd->mtx);

        ieee80211_send_deauth_disassoc(sdata, req->bss->bssid,
                        IEEE80211_STYPE_DISASSOC, req->reason_code,
                        cookie);
        return 0;
}