util.c

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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <[email protected]>
 * Copyright 2007   Johannes Berg <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * utilities for mac80211
 */

#include <net/mac80211.h>
#include <linux/netdevice.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/bitmap.h>
#include <linux/crc32.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
#include <net/rtnetlink.h>

#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "mesh.h"
#include "wme.h"
#include "led.h"
#include "wep.h"

/* privid for wiphys to determine whether they belong to us or not */
void *mac80211_wiphy_privid = &mac80211_wiphy_privid;

struct ieee80211_hw *wiphy_to_ieee80211_hw(struct wiphy *wiphy)
{
    struct ieee80211_local *local;
    BUG_ON(!wiphy);

    local = wiphy_priv(wiphy);
    return &local->hw;
}
EXPORT_SYMBOL(wiphy_to_ieee80211_hw);

u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
            enum nl80211_iftype type)
{
    __le16 fc = hdr->frame_control;

     /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
    if (len < 16)
        return NULL;

    if (ieee80211_is_data(fc)) {
        if (len < 24) /* drop incorrect hdr len (data) */
            return NULL;

        if (ieee80211_has_a4(fc))
            return NULL;
        if (ieee80211_has_tods(fc))
            return hdr->addr1;
        if (ieee80211_has_fromds(fc))
            return hdr->addr2;

        return hdr->addr3;
    }

    if (ieee80211_is_mgmt(fc)) {
        if (len < 24) /* drop incorrect hdr len (mgmt) */
            return NULL;
        return hdr->addr3;
    }

    if (ieee80211_is_ctl(fc)) {
        if(ieee80211_is_pspoll(fc))
            return hdr->addr1;

        if (ieee80211_is_back_req(fc)) {
            switch (type) {
            case NL80211_IFTYPE_STATION:
                return hdr->addr2;
            case NL80211_IFTYPE_AP:
            case NL80211_IFTYPE_AP_VLAN:
                return hdr->addr1;
            default:
                break; /* fall through to the return */
            }
        }
    }

    return NULL;
}

void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
{
    struct sk_buff *skb;
    struct ieee80211_hdr *hdr;

    skb_queue_walk(&tx->skbs, skb) {
        hdr = (struct ieee80211_hdr *) skb->data;
        hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
    }
}

int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
                 int rate, int erp, int short_preamble)
{
    int dur;

    /* calculate duration (in microseconds, rounded up to next higher
     * integer if it includes a fractional microsecond) to send frame of
     * len bytes (does not include FCS) at the given rate. Duration will
     * also include SIFS.
     *
     * rate is in 100 kbps, so divident is multiplied by 10 in the
     * DIV_ROUND_UP() operations.
     */

    if (band == IEEE80211_BAND_5GHZ || erp) {
        /*
         * OFDM:
         *
         * N_DBPS = DATARATE x 4
         * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
         *  (16 = SIGNAL time, 6 = tail bits)
         * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
         *
         * T_SYM = 4 usec
         * 802.11a - 17.5.2: aSIFSTime = 16 usec
         * 802.11g - 19.8.4: aSIFSTime = 10 usec +
         *  signal ext = 6 usec
         */
        dur = 16; /* SIFS + signal ext */
        dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
        dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
        dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
                    4 * rate); /* T_SYM x N_SYM */
    } else {
        /*
         * 802.11b or 802.11g with 802.11b compatibility:
         * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
         * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
         *
         * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
         * aSIFSTime = 10 usec
         * aPreambleLength = 144 usec or 72 usec with short preamble
         * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
         */
        dur = 10; /* aSIFSTime = 10 usec */
        dur += short_preamble ? (72 + 24) : (144 + 48);

        dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
    }

    return dur;
}

/* Exported duration function for driver use */
__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
                    struct ieee80211_vif *vif,
                    enum ieee80211_band band,
                    size_t frame_len,
                    struct ieee80211_rate *rate)
{
    struct ieee80211_sub_if_data *sdata;
    u16 dur;
    int erp;
    bool short_preamble = false;

    erp = 0;
    if (vif) {
        sdata = vif_to_sdata(vif);
        short_preamble = sdata->vif.bss_conf.use_short_preamble;
        if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
            erp = rate->flags & IEEE80211_RATE_ERP_G;
    }

    dur = ieee80211_frame_duration(band, frame_len, rate->bitrate, erp,
                       short_preamble);

    return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_generic_frame_duration);

__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif, size_t frame_len,
                  const struct ieee80211_tx_info *frame_txctl)
{
    struct ieee80211_local *local = hw_to_local(hw);
    struct ieee80211_rate *rate;
    struct ieee80211_sub_if_data *sdata;
    bool short_preamble;
    int erp;
    u16 dur;
    struct ieee80211_supported_band *sband;

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

    short_preamble = false;

    rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

    erp = 0;
    if (vif) {
        sdata = vif_to_sdata(vif);
        short_preamble = sdata->vif.bss_conf.use_short_preamble;
        if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
            erp = rate->flags & IEEE80211_RATE_ERP_G;
    }

    /* CTS duration */
    dur = ieee80211_frame_duration(sband->band, 10, rate->bitrate,
                       erp, short_preamble);
    /* Data frame duration */
    dur += ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
                    erp, short_preamble);
    /* ACK duration */
    dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
                    erp, short_preamble);

    return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_rts_duration);

__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
                    struct ieee80211_vif *vif,
                    size_t frame_len,
                    const struct ieee80211_tx_info *frame_txctl)
{
    struct ieee80211_local *local = hw_to_local(hw);
    struct ieee80211_rate *rate;
    struct ieee80211_sub_if_data *sdata;
    bool short_preamble;
    int erp;
    u16 dur;
    struct ieee80211_supported_band *sband;

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

    short_preamble = false;

    rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
    erp = 0;
    if (vif) {
        sdata = vif_to_sdata(vif);
        short_preamble = sdata->vif.bss_conf.use_short_preamble;
        if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
            erp = rate->flags & IEEE80211_RATE_ERP_G;
    }

    /* Data frame duration */
    dur = ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
                       erp, short_preamble);
    if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
        /* ACK duration */
        dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
                        erp, short_preamble);
    }

    return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_ctstoself_duration);

void ieee80211_propagate_queue_wake(struct ieee80211_local *local, int queue)
{
    struct ieee80211_sub_if_data *sdata;
    int n_acs = IEEE80211_NUM_ACS;

    if (local->hw.queues < IEEE80211_NUM_ACS)
        n_acs = 1;

    list_for_each_entry_rcu(sdata, &local->interfaces, list) {
        int ac;

        if (!sdata->dev)
            continue;

        if (test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))
            continue;

        if (sdata->vif.cab_queue != IEEE80211_INVAL_HW_QUEUE &&
            local->queue_stop_reasons[sdata->vif.cab_queue] != 0)
            continue;

        for (ac = 0; ac < n_acs; ac++) {
            int ac_queue = sdata->vif.hw_queue[ac];

            if (ac_queue == queue ||
                (sdata->vif.cab_queue == queue &&
                 local->queue_stop_reasons[ac_queue] == 0 &&
                 skb_queue_empty(&local->pending[ac_queue])))
                netif_wake_subqueue(sdata->dev, ac);
        }
    }
}

static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
                   enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);

    trace_wake_queue(local, queue, reason);

    if (WARN_ON(queue >= hw->queues))
        return;

    if (!test_bit(reason, &local->queue_stop_reasons[queue]))
        return;

    __clear_bit(reason, &local->queue_stop_reasons[queue]);

    if (local->queue_stop_reasons[queue] != 0)
        /* someone still has this queue stopped */
        return;

    if (skb_queue_empty(&local->pending[queue])) {
        rcu_read_lock();
        ieee80211_propagate_queue_wake(local, queue);
        rcu_read_unlock();
    } else
        tasklet_schedule(&local->tx_pending_tasklet);
}

void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
                    enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);
    unsigned long flags;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
    __ieee80211_wake_queue(hw, queue, reason);
    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
{
    ieee80211_wake_queue_by_reason(hw, queue,
                       IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_wake_queue);

static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
                   enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);
    struct ieee80211_sub_if_data *sdata;
    int n_acs = IEEE80211_NUM_ACS;

    trace_stop_queue(local, queue, reason);

    if (WARN_ON(queue >= hw->queues))
        return;

    if (test_bit(reason, &local->queue_stop_reasons[queue]))
        return;

    __set_bit(reason, &local->queue_stop_reasons[queue]);

    if (local->hw.queues < IEEE80211_NUM_ACS)
        n_acs = 1;

    rcu_read_lock();
    list_for_each_entry_rcu(sdata, &local->interfaces, list) {
        int ac;

        if (!sdata->dev)
            continue;

        for (ac = 0; ac < n_acs; ac++) {
            if (sdata->vif.hw_queue[ac] == queue ||
                sdata->vif.cab_queue == queue)
                netif_stop_subqueue(sdata->dev, ac);
        }
    }
    rcu_read_unlock();
}

void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,
                    enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);
    unsigned long flags;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
    __ieee80211_stop_queue(hw, queue, reason);
    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
{
    ieee80211_stop_queue_by_reason(hw, queue,
                       IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_stop_queue);

void ieee80211_add_pending_skb(struct ieee80211_local *local,
                   struct sk_buff *skb)
{
    struct ieee80211_hw *hw = &local->hw;
    unsigned long flags;
    struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
    int queue = info->hw_queue;

    if (WARN_ON(!info->control.vif)) {
        ieee80211_free_txskb(&local->hw, skb);
        return;
    }

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
    __ieee80211_stop_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
    __skb_queue_tail(&local->pending[queue], skb);
    __ieee80211_wake_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_add_pending_skbs_fn(struct ieee80211_local *local,
                   struct sk_buff_head *skbs,
                   void (*fn)(void *data), void *data)
{
    struct ieee80211_hw *hw = &local->hw;
    struct sk_buff *skb;
    unsigned long flags;
    int queue, i;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
    while ((skb = skb_dequeue(skbs))) {
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

        if (WARN_ON(!info->control.vif)) {
            ieee80211_free_txskb(&local->hw, skb);
            continue;
        }

        queue = info->hw_queue;

        __ieee80211_stop_queue(hw, queue,
                IEEE80211_QUEUE_STOP_REASON_SKB_ADD);

        __skb_queue_tail(&local->pending[queue], skb);
    }

    if (fn)
        fn(data);

    for (i = 0; i < hw->queues; i++)
        __ieee80211_wake_queue(hw, i,
            IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
                    enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);
    unsigned long flags;
    int i;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

    for (i = 0; i < hw->queues; i++)
        __ieee80211_stop_queue(hw, i, reason);

    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_stop_queues(struct ieee80211_hw *hw)
{
    ieee80211_stop_queues_by_reason(hw,
                    IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_stop_queues);

int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
{
    struct ieee80211_local *local = hw_to_local(hw);
    unsigned long flags;
    int ret;

    if (WARN_ON(queue >= hw->queues))
        return true;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
    ret = !!local->queue_stop_reasons[queue];
    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
    return ret;
}
EXPORT_SYMBOL(ieee80211_queue_stopped);

void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
                     enum queue_stop_reason reason)
{
    struct ieee80211_local *local = hw_to_local(hw);
    unsigned long flags;
    int i;

    spin_lock_irqsave(&local->queue_stop_reason_lock, flags);

    for (i = 0; i < hw->queues; i++)
        __ieee80211_wake_queue(hw, i, reason);

    spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}

void ieee80211_wake_queues(struct ieee80211_hw *hw)
{
    ieee80211_wake_queues_by_reason(hw, IEEE80211_QUEUE_STOP_REASON_DRIVER);
}
EXPORT_SYMBOL(ieee80211_wake_queues);

void ieee80211_iterate_active_interfaces(
    struct ieee80211_hw *hw,
    void (*iterator)(void *data, u8 *mac,
             struct ieee80211_vif *vif),
    void *data)
{
    struct ieee80211_local *local = hw_to_local(hw);
    struct ieee80211_sub_if_data *sdata;

    mutex_lock(&local->iflist_mtx);

    list_for_each_entry(sdata, &local->interfaces, list) {
        switch (sdata->vif.type) {
        case NL80211_IFTYPE_MONITOR:
        case NL80211_IFTYPE_AP_VLAN:
            continue;
        default:
            break;
        }
        if (ieee80211_sdata_running(sdata))
            iterator(data, sdata->vif.addr,
                 &sdata->vif);
    }

    sdata = rcu_dereference_protected(local->monitor_sdata,
                      lockdep_is_held(&local->iflist_mtx));
    if (sdata)
        iterator(data, sdata->vif.addr, &sdata->vif);

    mutex_unlock(&local->iflist_mtx);
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);

void ieee80211_iterate_active_interfaces_atomic(
    struct ieee80211_hw *hw,
    void (*iterator)(void *data, u8 *mac,
             struct ieee80211_vif *vif),
    void *data)
{
    struct ieee80211_local *local = hw_to_local(hw);
    struct ieee80211_sub_if_data *sdata;

    rcu_read_lock();

    list_for_each_entry_rcu(sdata, &local->interfaces, list) {
        switch (sdata->vif.type) {
        case NL80211_IFTYPE_MONITOR:
        case NL80211_IFTYPE_AP_VLAN:
            continue;
        default:
            break;
        }
        if (ieee80211_sdata_running(sdata))
            iterator(data, sdata->vif.addr,
                 &sdata->vif);
    }

    sdata = rcu_dereference(local->monitor_sdata);
    if (sdata)
        iterator(data, sdata->vif.addr, &sdata->vif);

    rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);

/*
 * 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.
 */
static bool ieee80211_can_queue_work(struct ieee80211_local *local)
{
    if (WARN(local->suspended && !local->resuming,
         "queueing ieee80211 work while going to suspend\n"))
        return false;

    return true;
}

void ieee80211_queue_work(struct ieee80211_hw *hw, struct work_struct *work)
{
    struct ieee80211_local *local = hw_to_local(hw);

    if (!ieee80211_can_queue_work(local))
        return;

    queue_work(local->workqueue, work);
}
EXPORT_SYMBOL(ieee80211_queue_work);

void ieee80211_queue_delayed_work(struct ieee80211_hw *hw,
                  struct delayed_work *dwork,
                  unsigned long delay)
{
    struct ieee80211_local *local = hw_to_local(hw);

    if (!ieee80211_can_queue_work(local))
        return;

    queue_delayed_work(local->workqueue, dwork, delay);
}
EXPORT_SYMBOL(ieee80211_queue_delayed_work);

u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
                   struct ieee802_11_elems *elems,
                   u64 filter, u32 crc)
{
    size_t left = len;
    u8 *pos = start;
    bool calc_crc = filter != 0;
    DECLARE_BITMAP(seen_elems, 256);

    bitmap_zero(seen_elems, 256);
    memset(elems, 0, sizeof(*elems));
    elems->ie_start = start;
    elems->total_len = len;

    while (left >= 2) {
        u8 id, elen;
        bool elem_parse_failed;

        id = *pos++;
        elen = *pos++;
        left -= 2;

        if (elen > left) {
            elems->parse_error = true;
            break;
        }

        switch (id) {
        case WLAN_EID_SSID:
        case WLAN_EID_SUPP_RATES:
        case WLAN_EID_FH_PARAMS:
        case WLAN_EID_DS_PARAMS:
        case WLAN_EID_CF_PARAMS:
        case WLAN_EID_TIM:
        case WLAN_EID_IBSS_PARAMS:
        case WLAN_EID_CHALLENGE:
        case WLAN_EID_RSN:
        case WLAN_EID_ERP_INFO:
        case WLAN_EID_EXT_SUPP_RATES:
        case WLAN_EID_HT_CAPABILITY:
        case WLAN_EID_HT_OPERATION:
        case WLAN_EID_VHT_CAPABILITY:
        case WLAN_EID_VHT_OPERATION:
        case WLAN_EID_MESH_ID:
        case WLAN_EID_MESH_CONFIG:
        case WLAN_EID_PEER_MGMT:
        case WLAN_EID_PREQ:
        case WLAN_EID_PREP:
        case WLAN_EID_PERR:
        case WLAN_EID_RANN:
        case WLAN_EID_CHANNEL_SWITCH:
        case WLAN_EID_EXT_CHANSWITCH_ANN:
        case WLAN_EID_COUNTRY:
        case WLAN_EID_PWR_CONSTRAINT:
        case WLAN_EID_TIMEOUT_INTERVAL:
            if (test_bit(id, seen_elems)) {
                elems->parse_error = true;
                left -= elen;
                pos += elen;
                continue;
            }
            break;
        }

        if (calc_crc && id < 64 && (filter & (1ULL << id)))
            crc = crc32_be(crc, pos - 2, elen + 2);

        elem_parse_failed = false;

        switch (id) {
        case WLAN_EID_SSID:
            elems->ssid = pos;
            elems->ssid_len = elen;
            break;
        case WLAN_EID_SUPP_RATES:
            elems->supp_rates = pos;
            elems->supp_rates_len = elen;
            break;
        case WLAN_EID_FH_PARAMS:
            elems->fh_params = pos;
            elems->fh_params_len = elen;
            break;
        case WLAN_EID_DS_PARAMS:
            elems->ds_params = pos;
            elems->ds_params_len = elen;
            break;
        case WLAN_EID_CF_PARAMS:
            elems->cf_params = pos;
            elems->cf_params_len = elen;
            break;
        case WLAN_EID_TIM:
            if (elen >= sizeof(struct ieee80211_tim_ie)) {
                elems->tim = (void *)pos;
                elems->tim_len = elen;
            } else
                elem_parse_failed = true;
            break;
        case WLAN_EID_IBSS_PARAMS:
            elems->ibss_params = pos;
            elems->ibss_params_len = elen;
            break;
        case WLAN_EID_CHALLENGE:
            elems->challenge = pos;
            elems->challenge_len = elen;
            break;
        case WLAN_EID_VENDOR_SPECIFIC:
            if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
                pos[2] == 0xf2) {
                /* Microsoft OUI (00:50:F2) */

                if (calc_crc)
                    crc = crc32_be(crc, pos - 2, elen + 2);

                if (pos[3] == 1) {
                    /* OUI Type 1 - WPA IE */
                    elems->wpa = pos;
                    elems->wpa_len = elen;
                } else if (elen >= 5 && pos[3] == 2) {
                    /* OUI Type 2 - WMM IE */
                    if (pos[4] == 0) {
                        elems->wmm_info = pos;
                        elems->wmm_info_len = elen;
                    } else if (pos[4] == 1) {
                        elems->wmm_param = pos;
                        elems->wmm_param_len = elen;
                    }
                }
            }
            break;
        case WLAN_EID_RSN:
            elems->rsn = pos;
            elems->rsn_len = elen;
            break;
        case WLAN_EID_ERP_INFO:
            elems->erp_info = pos;
            elems->erp_info_len = elen;
            break;
        case WLAN_EID_EXT_SUPP_RATES:
            elems->ext_supp_rates = pos;
            elems->ext_supp_rates_len = elen;
            break;
        case WLAN_EID_HT_CAPABILITY:
            if (elen >= sizeof(struct ieee80211_ht_cap))
                elems->ht_cap_elem = (void *)pos;
            else
                elem_parse_failed = true;
            break;
        case WLAN_EID_HT_OPERATION:
            if (elen >= sizeof(struct ieee80211_ht_operation))
                elems->ht_operation = (void *)pos;
            else
                elem_parse_failed = true;
            break;
        case WLAN_EID_MESH_ID:
            elems->mesh_id = pos;
            elems->mesh_id_len = elen;
            break;
        case WLAN_EID_MESH_CONFIG:
            if (elen >= sizeof(struct ieee80211_meshconf_ie))
                elems->mesh_config = (void *)pos;
            else
                elem_parse_failed = true;
            break;
        case WLAN_EID_PEER_MGMT:
            elems->peering = pos;
            elems->peering_len = elen;
            break;
        case WLAN_EID_PREQ:
            elems->preq = pos;
            elems->preq_len = elen;
            break;
        case WLAN_EID_PREP:
            elems->prep = pos;
            elems->prep_len = elen;
            break;
        case WLAN_EID_PERR:
            elems->perr = pos;
            elems->perr_len = elen;
            break;
        case WLAN_EID_RANN:
            if (elen >= sizeof(struct ieee80211_rann_ie))
                elems->rann = (void *)pos;
            else
                elem_parse_failed = true;
            break;
        case WLAN_EID_CHANNEL_SWITCH:
            if (elen != sizeof(struct ieee80211_channel_sw_ie)) {
                elem_parse_failed = true;
                break;
            }
            elems->ch_switch_ie = (void *)pos;
            break;
        case WLAN_EID_QUIET:
            if (!elems->quiet_elem) {
                elems->quiet_elem = pos;
                elems->quiet_elem_len = elen;
            }
            elems->num_of_quiet_elem++;
            break;
        case WLAN_EID_COUNTRY:
            elems->country_elem = pos;
            elems->country_elem_len = elen;
            break;
        case WLAN_EID_PWR_CONSTRAINT:
            if (elen != 1) {
                elem_parse_failed = true;
                break;
            }
            elems->pwr_constr_elem = pos;
            break;
        case WLAN_EID_TIMEOUT_INTERVAL:
            elems->timeout_int = pos;
            elems->timeout_int_len = elen;
            break;
        default:
            break;
        }

        if (elem_parse_failed)
            elems->parse_error = true;
        else
            set_bit(id, seen_elems);

        left -= elen;
        pos += elen;
    }

    if (left != 0)
        elems->parse_error = true;

    return crc;
}

void ieee802_11_parse_elems(u8 *start, size_t len,
                struct ieee802_11_elems *elems)
{
    ieee802_11_parse_elems_crc(start, len, elems, 0, 0);
}

void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata,
                   bool bss_notify)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_tx_queue_params qparam;
    int ac;
    bool use_11b, enable_qos;
    int aCWmin, aCWmax;

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

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

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

    use_11b = (local->oper_channel->band == IEEE80211_BAND_2GHZ) &&
         !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE);

    /*
     * By default disable QoS in STA mode for old access points, which do
     * not support 802.11e. New APs will provide proper queue parameters,
     * that we will configure later.
     */
    enable_qos = (sdata->vif.type != NL80211_IFTYPE_STATION);

    for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
        /* Set defaults according to 802.11-2007 Table 7-37 */
        aCWmax = 1023;
        if (use_11b)
            aCWmin = 31;
        else
            aCWmin = 15;

        if (enable_qos) {
            switch (ac) {
            case IEEE80211_AC_BK:
                qparam.cw_max = aCWmax;
                qparam.cw_min = aCWmin;
                qparam.txop = 0;
                qparam.aifs = 7;
                break;
            /* never happens but let's not leave undefined */
            default:
            case IEEE80211_AC_BE:
                qparam.cw_max = aCWmax;
                qparam.cw_min = aCWmin;
                qparam.txop = 0;
                qparam.aifs = 3;
                break;
            case IEEE80211_AC_VI:
                qparam.cw_max = aCWmin;
                qparam.cw_min = (aCWmin + 1) / 2 - 1;
                if (use_11b)
                    qparam.txop = 6016/32;
                else
                    qparam.txop = 3008/32;
                qparam.aifs = 2;
                break;
            case IEEE80211_AC_VO:
                qparam.cw_max = (aCWmin + 1) / 2 - 1;
                qparam.cw_min = (aCWmin + 1) / 4 - 1;
                if (use_11b)
                    qparam.txop = 3264/32;
                else
                    qparam.txop = 1504/32;
                qparam.aifs = 2;
                break;
            }
        } else {
            /* Confiure old 802.11b/g medium access rules. */
            qparam.cw_max = aCWmax;
            qparam.cw_min = aCWmin;
            qparam.txop = 0;
            qparam.aifs = 2;
        }

        qparam.uapsd = false;

        sdata->tx_conf[ac] = qparam;
        drv_conf_tx(local, sdata, ac, &qparam);
    }

    if (sdata->vif.type != NL80211_IFTYPE_MONITOR &&
        sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE) {
        sdata->vif.bss_conf.qos = enable_qos;
        if (bss_notify)
            ieee80211_bss_info_change_notify(sdata,
                             BSS_CHANGED_QOS);
    }
}

void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
                  const size_t supp_rates_len,
                  const u8 *supp_rates)
{
    struct ieee80211_local *local = sdata->local;
    int i, have_higher_than_11mbit = 0;

    /* cf. IEEE 802.11 9.2.12 */
    for (i = 0; i < supp_rates_len; i++)
        if ((supp_rates[i] & 0x7f) * 5 > 110)
            have_higher_than_11mbit = 1;

    if (local->oper_channel->band == IEEE80211_BAND_2GHZ &&
        have_higher_than_11mbit)
        sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
    else
        sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;

    ieee80211_set_wmm_default(sdata, true);
}

u32 ieee80211_mandatory_rates(struct ieee80211_local *local,
                  enum ieee80211_band band)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_rate *bitrates;
    u32 mandatory_rates;
    enum ieee80211_rate_flags mandatory_flag;
    int i;

    sband = local->hw.wiphy->bands[band];
    if (WARN_ON(!sband))
        return 1;

    if (band == IEEE80211_BAND_2GHZ)
        mandatory_flag = IEEE80211_RATE_MANDATORY_B;
    else
        mandatory_flag = IEEE80211_RATE_MANDATORY_A;

    bitrates = sband->bitrates;
    mandatory_rates = 0;
    for (i = 0; i < sband->n_bitrates; i++)
        if (bitrates[i].flags & mandatory_flag)
            mandatory_rates |= BIT(i);
    return mandatory_rates;
}

void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
             u16 transaction, u16 auth_alg,
             u8 *extra, size_t extra_len, const u8 *da,
             const u8 *bssid, const u8 *key, u8 key_len, u8 key_idx)
{
    struct ieee80211_local *local = sdata->local;
    struct sk_buff *skb;
    struct ieee80211_mgmt *mgmt;
    int err;

    skb = dev_alloc_skb(local->hw.extra_tx_headroom +
                sizeof(*mgmt) + 6 + extra_len);
    if (!skb)
        return;

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

    mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24 + 6);
    memset(mgmt, 0, 24 + 6);
    mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                      IEEE80211_STYPE_AUTH);
    memcpy(mgmt->da, da, ETH_ALEN);
    memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
    memcpy(mgmt->bssid, bssid, ETH_ALEN);
    mgmt->u.auth.auth_alg = cpu_to_le16(auth_alg);
    mgmt->u.auth.auth_transaction = cpu_to_le16(transaction);
    mgmt->u.auth.status_code = cpu_to_le16(0);
    if (extra)
        memcpy(skb_put(skb, extra_len), extra, extra_len);

    if (auth_alg == WLAN_AUTH_SHARED_KEY && transaction == 3) {
        mgmt->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
        err = ieee80211_wep_encrypt(local, skb, key, key_len, key_idx);
        WARN_ON(err);
    }

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

void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
                    const u8 *bssid, u16 stype, u16 reason,
                    bool send_frame, u8 *frame_buf)
{
    struct ieee80211_local *local = sdata->local;
    struct sk_buff *skb;
    struct ieee80211_mgmt *mgmt = (void *)frame_buf;

    /* build frame */
    mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | stype);
    mgmt->duration = 0; /* initialize only */
    mgmt->seq_ctrl = 0; /* initialize only */
    memcpy(mgmt->da, bssid, ETH_ALEN);
    memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
    memcpy(mgmt->bssid, bssid, ETH_ALEN);
    /* u.deauth.reason_code == u.disassoc.reason_code */
    mgmt->u.deauth.reason_code = cpu_to_le16(reason);

    if (send_frame) {
        skb = dev_alloc_skb(local->hw.extra_tx_headroom +
                    IEEE80211_DEAUTH_FRAME_LEN);
        if (!skb)
            return;

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

        /* copy in frame */
        memcpy(skb_put(skb, IEEE80211_DEAUTH_FRAME_LEN),
               mgmt, IEEE80211_DEAUTH_FRAME_LEN);

        if (sdata->vif.type != NL80211_IFTYPE_STATION ||
            !(sdata->u.mgd.flags & IEEE80211_STA_MFP_ENABLED))
            IEEE80211_SKB_CB(skb)->flags |=
                IEEE80211_TX_INTFL_DONT_ENCRYPT;

        ieee80211_tx_skb(sdata, skb);
    }
}

int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
                 const u8 *ie, size_t ie_len,
                 enum ieee80211_band band, u32 rate_mask,
                 u8 channel)
{
    struct ieee80211_supported_band *sband;
    u8 *pos;
    size_t offset = 0, noffset;
    int supp_rates_len, i;
    u8 rates[32];
    int num_rates;
    int ext_rates_len;

    sband = local->hw.wiphy->bands[band];
    if (WARN_ON_ONCE(!sband))
        return 0;

    pos = buffer;

    num_rates = 0;
    for (i = 0; i < sband->n_bitrates; i++) {
        if ((BIT(i) & rate_mask) == 0)
            continue; /* skip rate */
        rates[num_rates++] = (u8) (sband->bitrates[i].bitrate / 5);
    }

    supp_rates_len = min_t(int, num_rates, 8);

    *pos++ = WLAN_EID_SUPP_RATES;
    *pos++ = supp_rates_len;
    memcpy(pos, rates, supp_rates_len);
    pos += supp_rates_len;

    /* insert "request information" if in custom IEs */
    if (ie && ie_len) {
        static const u8 before_extrates[] = {
            WLAN_EID_SSID,
            WLAN_EID_SUPP_RATES,
            WLAN_EID_REQUEST,
        };
        noffset = ieee80211_ie_split(ie, ie_len,
                         before_extrates,
                         ARRAY_SIZE(before_extrates),
                         offset);
        memcpy(pos, ie + offset, noffset - offset);
        pos += noffset - offset;
        offset = noffset;
    }

    ext_rates_len = num_rates - supp_rates_len;
    if (ext_rates_len > 0) {
        *pos++ = WLAN_EID_EXT_SUPP_RATES;
        *pos++ = ext_rates_len;
        memcpy(pos, rates + supp_rates_len, ext_rates_len);
        pos += ext_rates_len;
    }

    if (channel && sband->band == IEEE80211_BAND_2GHZ) {
        *pos++ = WLAN_EID_DS_PARAMS;
        *pos++ = 1;
        *pos++ = channel;
    }

    /* insert custom IEs that go before HT */
    if (ie && ie_len) {
        static const u8 before_ht[] = {
            WLAN_EID_SSID,
            WLAN_EID_SUPP_RATES,
            WLAN_EID_REQUEST,
            WLAN_EID_EXT_SUPP_RATES,
            WLAN_EID_DS_PARAMS,
            WLAN_EID_SUPPORTED_REGULATORY_CLASSES,
        };
        noffset = ieee80211_ie_split(ie, ie_len,
                         before_ht, ARRAY_SIZE(before_ht),
                         offset);
        memcpy(pos, ie + offset, noffset - offset);
        pos += noffset - offset;
        offset = noffset;
    }

    if (sband->ht_cap.ht_supported)
        pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
                        sband->ht_cap.cap);

    /*
     * If adding more here, adjust code in main.c
     * that calculates local->scan_ies_len.
     */

    /* add any remaining custom IEs */
    if (ie && ie_len) {
        noffset = ie_len;
        memcpy(pos, ie + offset, noffset - offset);
        pos += noffset - offset;
    }

    if (sband->vht_cap.vht_supported)
        pos = ieee80211_ie_build_vht_cap(pos, &sband->vht_cap,
                         sband->vht_cap.cap);

    return pos - buffer;
}

struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
                      u8 *dst, u32 ratemask,
                      struct ieee80211_channel *chan,
                      const u8 *ssid, size_t ssid_len,
                      const u8 *ie, size_t ie_len,
                      bool directed)
{
    struct ieee80211_local *local = sdata->local;
    struct sk_buff *skb;
    struct ieee80211_mgmt *mgmt;
    size_t buf_len;
    u8 *buf;
    u8 chan_no;

    /* FIXME: come up with a proper value */
    buf = kmalloc(200 + ie_len, GFP_KERNEL);
    if (!buf)
        return NULL;

    /*
     * Do not send DS Channel parameter for directed probe requests
     * in order to maximize the chance that we get a response.  Some
     * badly-behaved APs don't respond when this parameter is included.
     */
    if (directed)
        chan_no = 0;
    else
        chan_no = ieee80211_frequency_to_channel(chan->center_freq);

    buf_len = ieee80211_build_preq_ies(local, buf, ie, ie_len, chan->band,
                       ratemask, chan_no);

    skb = ieee80211_probereq_get(&local->hw, &sdata->vif,
                     ssid, ssid_len,
                     buf, buf_len);
    if (!skb)
        goto out;

    if (dst) {
        mgmt = (struct ieee80211_mgmt *) skb->data;
        memcpy(mgmt->da, dst, ETH_ALEN);
        memcpy(mgmt->bssid, dst, ETH_ALEN);
    }

    IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;

 out:
    kfree(buf);

    return skb;
}

void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
                  const u8 *ssid, size_t ssid_len,
                  const u8 *ie, size_t ie_len,
                  u32 ratemask, bool directed, bool no_cck,
                  struct ieee80211_channel *channel)
{
    struct sk_buff *skb;

    skb = ieee80211_build_probe_req(sdata, dst, ratemask, channel,
                    ssid, ssid_len,
                    ie, ie_len, directed);
    if (skb) {
        if (no_cck)
            IEEE80211_SKB_CB(skb)->flags |=
                IEEE80211_TX_CTL_NO_CCK_RATE;
        ieee80211_tx_skb(sdata, skb);
    }
}

u32 ieee80211_sta_get_rates(struct ieee80211_local *local,
                struct ieee802_11_elems *elems,
                enum ieee80211_band band, u32 *basic_rates)
{
    struct ieee80211_supported_band *sband;
    struct ieee80211_rate *bitrates;
    size_t num_rates;
    u32 supp_rates;
    int i, j;
    sband = local->hw.wiphy->bands[band];

    if (WARN_ON(!sband))
        return 1;

    bitrates = sband->bitrates;
    num_rates = sband->n_bitrates;
    supp_rates = 0;
    for (i = 0; i < elems->supp_rates_len +
             elems->ext_supp_rates_len; i++) {
        u8 rate = 0;
        int own_rate;
        bool is_basic;
        if (i < elems->supp_rates_len)
            rate = elems->supp_rates[i];
        else if (elems->ext_supp_rates)
            rate = elems->ext_supp_rates
                [i - elems->supp_rates_len];
        own_rate = 5 * (rate & 0x7f);
        is_basic = !!(rate & 0x80);

        if (is_basic && (rate & 0x7f) == BSS_MEMBERSHIP_SELECTOR_HT_PHY)
            continue;

        for (j = 0; j < num_rates; j++) {
            if (bitrates[j].bitrate == own_rate) {
                supp_rates |= BIT(j);
                if (basic_rates && is_basic)
                    *basic_rates |= BIT(j);
            }
        }
    }
    return supp_rates;
}

void ieee80211_stop_device(struct ieee80211_local *local)
{
    ieee80211_led_radio(local, false);
    ieee80211_mod_tpt_led_trig(local, 0, IEEE80211_TPT_LEDTRIG_FL_RADIO);

    cancel_work_sync(&local->reconfig_filter);

    flush_workqueue(local->workqueue);
    drv_stop(local);
}

int ieee80211_reconfig(struct ieee80211_local *local)
{
    struct ieee80211_hw *hw = &local->hw;
    struct ieee80211_sub_if_data *sdata;
    struct sta_info *sta;
    int res, i;

#ifdef CONFIG_PM
    if (local->suspended)
        local->resuming = true;

    if (local->wowlan) {
        local->wowlan = false;
        res = drv_resume(local);
        if (res < 0) {
            local->resuming = false;
            return res;
        }
        if (res == 0)
            goto wake_up;
        WARN_ON(res > 1);
        /*
         * res is 1, which means the driver requested
         * to go through a regular reset on wakeup.
         */
    }
#endif
    /* everything else happens only if HW was up & running */
    if (!local->open_count)
        goto wake_up;

    /*
     * Upon resume hardware can sometimes be goofy due to
     * various platform / driver / bus issues, so restarting
     * the device may at times not work immediately. Propagate
     * the error.
     */
    res = drv_start(local);
    if (res) {
        WARN(local->suspended, "Hardware became unavailable "
             "upon resume. This could be a software issue "
             "prior to suspend or a hardware issue.\n");
        return res;
    }

    /* setup fragmentation threshold */
    drv_set_frag_threshold(local, hw->wiphy->frag_threshold);

    /* setup RTS threshold */
    drv_set_rts_threshold(local, hw->wiphy->rts_threshold);

    /* reset coverage class */
    drv_set_coverage_class(local, hw->wiphy->coverage_class);

    ieee80211_led_radio(local, true);
    ieee80211_mod_tpt_led_trig(local,
                   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);

    /* add interfaces */
    sdata = rtnl_dereference(local->monitor_sdata);
    if (sdata) {
        res = drv_add_interface(local, sdata);
        if (WARN_ON(res)) {
            rcu_assign_pointer(local->monitor_sdata, NULL);
            synchronize_net();
            kfree(sdata);
        }
    }

    list_for_each_entry(sdata, &local->interfaces, list) {
        if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
            sdata->vif.type != NL80211_IFTYPE_MONITOR &&
            ieee80211_sdata_running(sdata))
            res = drv_add_interface(local, sdata);
    }

    /* add STAs back */
    mutex_lock(&local->sta_mtx);
    list_for_each_entry(sta, &local->sta_list, list) {
        enum ieee80211_sta_state state;

        if (!sta->uploaded)
            continue;

        /* AP-mode stations will be added later */
        if (sta->sdata->vif.type == NL80211_IFTYPE_AP)
            continue;

        for (state = IEEE80211_STA_NOTEXIST;
             state < sta->sta_state; state++)
            WARN_ON(drv_sta_state(local, sta->sdata, sta, state,
                          state + 1));
    }
    mutex_unlock(&local->sta_mtx);

    /* reconfigure tx conf */
    if (hw->queues >= IEEE80211_NUM_ACS) {
        list_for_each_entry(sdata, &local->interfaces, list) {
            if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
                sdata->vif.type == NL80211_IFTYPE_MONITOR ||
                !ieee80211_sdata_running(sdata))
                continue;

            for (i = 0; i < IEEE80211_NUM_ACS; i++)
                drv_conf_tx(local, sdata, i,
                        &sdata->tx_conf[i]);
        }
    }

    /* reconfigure hardware */
    ieee80211_hw_config(local, ~0);

    ieee80211_configure_filter(local);

    /* Finally also reconfigure all the BSS information */
    list_for_each_entry(sdata, &local->interfaces, list) {
        u32 changed;

        if (!ieee80211_sdata_running(sdata))
            continue;

        /* common change flags for all interface types */
        changed = BSS_CHANGED_ERP_CTS_PROT |
              BSS_CHANGED_ERP_PREAMBLE |
              BSS_CHANGED_ERP_SLOT |
              BSS_CHANGED_HT |
              BSS_CHANGED_BASIC_RATES |
              BSS_CHANGED_BEACON_INT |
              BSS_CHANGED_BSSID |
              BSS_CHANGED_CQM |
              BSS_CHANGED_QOS |
              BSS_CHANGED_IDLE;

        switch (sdata->vif.type) {
        case NL80211_IFTYPE_STATION:
            changed |= BSS_CHANGED_ASSOC |
                   BSS_CHANGED_ARP_FILTER |
                   BSS_CHANGED_PS;
            mutex_lock(&sdata->u.mgd.mtx);
            ieee80211_bss_info_change_notify(sdata, changed);
            mutex_unlock(&sdata->u.mgd.mtx);
            break;
        case NL80211_IFTYPE_ADHOC:
            changed |= BSS_CHANGED_IBSS;
            /* fall through */
        case NL80211_IFTYPE_AP:
            changed |= BSS_CHANGED_SSID;

            if (sdata->vif.type == NL80211_IFTYPE_AP)
                changed |= BSS_CHANGED_AP_PROBE_RESP;

            /* fall through */
        case NL80211_IFTYPE_MESH_POINT:
            changed |= BSS_CHANGED_BEACON |
                   BSS_CHANGED_BEACON_ENABLED;
            ieee80211_bss_info_change_notify(sdata, changed);
            break;
        case NL80211_IFTYPE_WDS:
            break;
        case NL80211_IFTYPE_AP_VLAN:
        case NL80211_IFTYPE_MONITOR:
            /* ignore virtual */
            break;
        case NL80211_IFTYPE_P2P_DEVICE:
            changed = BSS_CHANGED_IDLE;
            break;
        case NL80211_IFTYPE_UNSPECIFIED:
        case NUM_NL80211_IFTYPES:
        case NL80211_IFTYPE_P2P_CLIENT:
        case NL80211_IFTYPE_P2P_GO:
            WARN_ON(1);
            break;
        }
    }

    ieee80211_recalc_ps(local, -1);

    /*
     * The sta might be in psm against the ap (e.g. because
     * this was the state before a hw restart), so we
     * explicitly send a null packet in order to make sure
     * it'll sync against the ap (and get out of psm).
     */
    if (!(local->hw.conf.flags & IEEE80211_CONF_PS)) {
        list_for_each_entry(sdata, &local->interfaces, list) {
            if (sdata->vif.type != NL80211_IFTYPE_STATION)
                continue;
            if (!sdata->u.mgd.associated)
                continue;

            ieee80211_send_nullfunc(local, sdata, 0);
        }
    }

    /* APs are now beaconing, add back stations */
    mutex_lock(&local->sta_mtx);
    list_for_each_entry(sta, &local->sta_list, list) {
        enum ieee80211_sta_state state;

        if (!sta->uploaded)
            continue;

        if (sta->sdata->vif.type != NL80211_IFTYPE_AP)
            continue;

        for (state = IEEE80211_STA_NOTEXIST;
             state < sta->sta_state; state++)
            WARN_ON(drv_sta_state(local, sta->sdata, sta, state,
                          state + 1));
    }
    mutex_unlock(&local->sta_mtx);

    /* add back keys */
    list_for_each_entry(sdata, &local->interfaces, list)
        if (ieee80211_sdata_running(sdata))
            ieee80211_enable_keys(sdata);

 wake_up:
    local->in_reconfig = false;
    barrier();

    /*
     * Clear the WLAN_STA_BLOCK_BA flag so new aggregation
     * sessions can be established after a resume.
     *
     * Also tear down aggregation sessions since reconfiguring
     * them in a hardware restart scenario is not easily done
     * right now, and the hardware will have lost information
     * about the sessions, but we and the AP still think they
     * are active. This is really a workaround though.
     */
    if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
        mutex_lock(&local->sta_mtx);

        list_for_each_entry(sta, &local->sta_list, list) {
            ieee80211_sta_tear_down_BA_sessions(sta, true);
            clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
        }

        mutex_unlock(&local->sta_mtx);
    }

    ieee80211_wake_queues_by_reason(hw,
            IEEE80211_QUEUE_STOP_REASON_SUSPEND);

    /*
     * If this is for hw restart things are still running.
     * We may want to change that later, however.
     */
    if (!local->suspended)
        return 0;

#ifdef CONFIG_PM
    /* first set suspended false, then resuming */
    local->suspended = false;
    mb();
    local->resuming = false;

    list_for_each_entry(sdata, &local->interfaces, list) {
        switch(sdata->vif.type) {
        case NL80211_IFTYPE_STATION:
            ieee80211_sta_restart(sdata);
            break;
        case NL80211_IFTYPE_ADHOC:
            ieee80211_ibss_restart(sdata);
            break;
        case NL80211_IFTYPE_MESH_POINT:
            ieee80211_mesh_restart(sdata);
            break;
        default:
            break;
        }
    }

    mod_timer(&local->sta_cleanup, jiffies + 1);

    mutex_lock(&local->sta_mtx);
    list_for_each_entry(sta, &local->sta_list, list)
        mesh_plink_restart(sta);
    mutex_unlock(&local->sta_mtx);
#else
    WARN_ON(1);
#endif
    return 0;
}

void ieee80211_resume_disconnect(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata;
    struct ieee80211_local *local;
    struct ieee80211_key *key;

    if (WARN_ON(!vif))
        return;

    sdata = vif_to_sdata(vif);
    local = sdata->local;

    if (WARN_ON(!local->resuming))
        return;

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

    sdata->flags |= IEEE80211_SDATA_DISCONNECT_RESUME;

    mutex_lock(&local->key_mtx);
    list_for_each_entry(key, &sdata->key_list, list)
        key->flags |= KEY_FLAG_TAINTED;
    mutex_unlock(&local->key_mtx);
}
EXPORT_SYMBOL_GPL(ieee80211_resume_disconnect);

static int check_mgd_smps(struct ieee80211_if_managed *ifmgd,
              enum ieee80211_smps_mode *smps_mode)
{
    if (ifmgd->associated) {
        *smps_mode = ifmgd->ap_smps;

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

        return 1;
    }

    return 0;
}

void ieee80211_recalc_smps(struct ieee80211_local *local)
{
    struct ieee80211_sub_if_data *sdata;
    enum ieee80211_smps_mode smps_mode = IEEE80211_SMPS_OFF;
    int count = 0;

    mutex_lock(&local->iflist_mtx);

    /*
     * This function could be improved to handle multiple
     * interfaces better, but right now it makes any
     * non-station interfaces force SM PS to be turned
     * off. If there are multiple station interfaces it
     * could also use the best possible mode, e.g. if
     * one is in static and the other in dynamic then
     * dynamic is ok.
     */

    list_for_each_entry(sdata, &local->interfaces, list) {
        if (!ieee80211_sdata_running(sdata))
            continue;
        if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
            continue;
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
            goto set;

        count += check_mgd_smps(&sdata->u.mgd, &smps_mode);

        if (count > 1) {
            smps_mode = IEEE80211_SMPS_OFF;
            break;
        }
    }

    if (smps_mode == local->smps_mode)
        goto unlock;

 set:
    local->smps_mode = smps_mode;
    /* changed flag is auto-detected for this */
    ieee80211_hw_config(local, 0);
 unlock:
    mutex_unlock(&local->iflist_mtx);
}

static bool ieee80211_id_in_list(const u8 *ids, int n_ids, u8 id)
{
    int i;

    for (i = 0; i < n_ids; i++)
        if (ids[i] == id)
            return true;
    return false;
}

size_t ieee80211_ie_split(const u8 *ies, size_t ielen,
              const u8 *ids, int n_ids, size_t offset)
{
    size_t pos = offset;

    while (pos < ielen && ieee80211_id_in_list(ids, n_ids, ies[pos]))
        pos += 2 + ies[pos + 1];

    return pos;
}

size_t ieee80211_ie_split_vendor(const u8 *ies, size_t ielen, size_t offset)
{
    size_t pos = offset;

    while (pos < ielen && ies[pos] != WLAN_EID_VENDOR_SPECIFIC)
        pos += 2 + ies[pos + 1];

    return pos;
}

static void _ieee80211_enable_rssi_reports(struct ieee80211_sub_if_data *sdata,
                        int rssi_min_thold,
                        int rssi_max_thold)
{
    trace_api_enable_rssi_reports(sdata, rssi_min_thold, rssi_max_thold);

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

    /*
     * Scale up threshold values before storing it, as the RSSI averaging
     * algorithm uses a scaled up value as well. Change this scaling
     * factor if the RSSI averaging algorithm changes.
     */
    sdata->u.mgd.rssi_min_thold = rssi_min_thold*16;
    sdata->u.mgd.rssi_max_thold = rssi_max_thold*16;
}

void ieee80211_enable_rssi_reports(struct ieee80211_vif *vif,
                    int rssi_min_thold,
                    int rssi_max_thold)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

    WARN_ON(rssi_min_thold == rssi_max_thold ||
        rssi_min_thold > rssi_max_thold);

    _ieee80211_enable_rssi_reports(sdata, rssi_min_thold,
                       rssi_max_thold);
}
EXPORT_SYMBOL(ieee80211_enable_rssi_reports);

void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

    _ieee80211_enable_rssi_reports(sdata, 0, 0);
}
EXPORT_SYMBOL(ieee80211_disable_rssi_reports);

u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                  u16 cap)
{
    __le16 tmp;

    *pos++ = WLAN_EID_HT_CAPABILITY;
    *pos++ = sizeof(struct ieee80211_ht_cap);
    memset(pos, 0, sizeof(struct ieee80211_ht_cap));

    /* capability flags */
    tmp = cpu_to_le16(cap);
    memcpy(pos, &tmp, sizeof(u16));
    pos += sizeof(u16);

    /* AMPDU parameters */
    *pos++ = ht_cap->ampdu_factor |
         (ht_cap->ampdu_density <<
            IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);

    /* MCS set */
    memcpy(pos, &ht_cap->mcs, sizeof(ht_cap->mcs));
    pos += sizeof(ht_cap->mcs);

    /* extended capabilities */
    pos += sizeof(__le16);

    /* BF capabilities */
    pos += sizeof(__le32);

    /* antenna selection */
    pos += sizeof(u8);

    return pos;
}

u8 *ieee80211_ie_build_vht_cap(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
                               u32 cap)
{
    __le32 tmp;

    *pos++ = WLAN_EID_VHT_CAPABILITY;
    *pos++ = sizeof(struct ieee80211_vht_capabilities);
    memset(pos, 0, sizeof(struct ieee80211_vht_capabilities));

    /* capability flags */
    tmp = cpu_to_le32(cap);
    memcpy(pos, &tmp, sizeof(u32));
    pos += sizeof(u32);

    /* VHT MCS set */
    memcpy(pos, &vht_cap->vht_mcs, sizeof(vht_cap->vht_mcs));
    pos += sizeof(vht_cap->vht_mcs);

    return pos;
}

u8 *ieee80211_ie_build_ht_oper(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                   struct ieee80211_channel *channel,
                   enum nl80211_channel_type channel_type,
                   u16 prot_mode)
{
    struct ieee80211_ht_operation *ht_oper;
    /* Build HT Information */
    *pos++ = WLAN_EID_HT_OPERATION;
    *pos++ = sizeof(struct ieee80211_ht_operation);
    ht_oper = (struct ieee80211_ht_operation *)pos;
    ht_oper->primary_chan =
            ieee80211_frequency_to_channel(channel->center_freq);
    switch (channel_type) {
    case NL80211_CHAN_HT40MINUS:
        ht_oper->ht_param = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
        break;
    case NL80211_CHAN_HT40PLUS:
        ht_oper->ht_param = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
        break;
    case NL80211_CHAN_HT20:
    default:
        ht_oper->ht_param = IEEE80211_HT_PARAM_CHA_SEC_NONE;
        break;
    }
    if (ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 &&
        channel_type != NL80211_CHAN_NO_HT &&
        channel_type != NL80211_CHAN_HT20)
        ht_oper->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;

    ht_oper->operation_mode = cpu_to_le16(prot_mode);
    ht_oper->stbc_param = 0x0000;

    /* It seems that Basic MCS set and Supported MCS set
       are identical for the first 10 bytes */
    memset(&ht_oper->basic_set, 0, 16);
    memcpy(&ht_oper->basic_set, &ht_cap->mcs, 10);

    return pos + sizeof(struct ieee80211_ht_operation);
}

enum nl80211_channel_type
ieee80211_ht_oper_to_channel_type(struct ieee80211_ht_operation *ht_oper)
{
    enum nl80211_channel_type channel_type;

    if (!ht_oper)
        return NL80211_CHAN_NO_HT;

    switch (ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
    case IEEE80211_HT_PARAM_CHA_SEC_NONE:
        channel_type = NL80211_CHAN_HT20;
        break;
    case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
        channel_type = NL80211_CHAN_HT40PLUS;
        break;
    case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
        channel_type = NL80211_CHAN_HT40MINUS;
        break;
    default:
        channel_type = NL80211_CHAN_NO_HT;
    }

    return channel_type;
}

int ieee80211_add_srates_ie(struct ieee80211_sub_if_data *sdata,
                struct sk_buff *skb, bool need_basic,
                enum ieee80211_band band)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_supported_band *sband;
    int rate;
    u8 i, rates, *pos;
    u32 basic_rates = sdata->vif.bss_conf.basic_rates;

    sband = local->hw.wiphy->bands[band];
    rates = sband->n_bitrates;
    if (rates > 8)
        rates = 8;

    if (skb_tailroom(skb) < rates + 2)
        return -ENOMEM;

    pos = skb_put(skb, rates + 2);
    *pos++ = WLAN_EID_SUPP_RATES;
    *pos++ = rates;
    for (i = 0; i < rates; i++) {
        u8 basic = 0;
        if (need_basic && basic_rates & BIT(i))
            basic = 0x80;
        rate = sband->bitrates[i].bitrate;
        *pos++ = basic | (u8) (rate / 5);
    }

    return 0;
}

int ieee80211_add_ext_srates_ie(struct ieee80211_sub_if_data *sdata,
                struct sk_buff *skb, bool need_basic,
                enum ieee80211_band band)
{
    struct ieee80211_local *local = sdata->local;
    struct ieee80211_supported_band *sband;
    int rate;
    u8 i, exrates, *pos;
    u32 basic_rates = sdata->vif.bss_conf.basic_rates;

    sband = local->hw.wiphy->bands[band];
    exrates = sband->n_bitrates;
    if (exrates > 8)
        exrates -= 8;
    else
        exrates = 0;

    if (skb_tailroom(skb) < exrates + 2)
        return -ENOMEM;

    if (exrates) {
        pos = skb_put(skb, exrates + 2);
        *pos++ = WLAN_EID_EXT_SUPP_RATES;
        *pos++ = exrates;
        for (i = 8; i < sband->n_bitrates; i++) {
            u8 basic = 0;
            if (need_basic && basic_rates & BIT(i))
                basic = 0x80;
            rate = sband->bitrates[i].bitrate;
            *pos++ = basic | (u8) (rate / 5);
        }
    }
    return 0;
}

int ieee80211_ave_rssi(struct ieee80211_vif *vif)
{
    struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
    struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

    if (WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_STATION)) {
        /* non-managed type inferfaces */
        return 0;
    }
    return ifmgd->ave_beacon_signal;
}
EXPORT_SYMBOL_GPL(ieee80211_ave_rssi);