util.c

Go to the documentation of this file.

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007       Johannes Berg <johannes@sipsolutions.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.
 *
 * 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 <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 = tx->skb;
        struct ieee80211_hdr *hdr;

        do {
                hdr = (struct ieee80211_hdr *) skb->data;
                hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
        } while ((skb = skb->next));
}

int ieee80211_frame_duration(struct ieee80211_local *local, 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 (local->hw.conf.channel->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,
                                        size_t frame_len,
                                        struct ieee80211_rate *rate)
{
        struct ieee80211_local *local = hw_to_local(hw);
        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(local, 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[local->hw.conf.channel->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(local, 10, rate->bitrate,
                                       erp, short_preamble);
        /* Data frame duration */
        dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
                                        erp, short_preamble);
        /* ACK duration */
        dur += ieee80211_frame_duration(local, 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[local->hw.conf.channel->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(local, frame_len, rate->bitrate,
                                       erp, short_preamble);
        if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
                /* ACK duration */
                dur += ieee80211_frame_duration(local, 10, rate->bitrate,
                                                erp, short_preamble);
        }

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

static void __ieee80211_wake_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;

        trace_wake_queue(local, queue, reason);

        if (WARN_ON(queue >= hw->queues))
                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();
                list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                        if (test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))
                                continue;
                        netif_wake_subqueue(sdata->dev, 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;

        trace_stop_queue(local, queue, reason);

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

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

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list)
                netif_stop_subqueue(sdata->dev, queue);
        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;
        int queue = skb_get_queue_mapping(skb);
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

        if (WARN_ON(!info->control.vif)) {
                kfree_skb(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);
        for (i = 0; i < hw->queues; i++)
                __ieee80211_stop_queue(hw, i,
                        IEEE80211_QUEUE_STOP_REASON_SKB_ADD);

        while ((skb = skb_dequeue(skbs))) {
                struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

                if (WARN_ON(!info->control.vif)) {
                        kfree_skb(skb);
                        continue;
                }

                queue = skb_get_queue_mapping(skb);
                __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_add_pending_skbs(struct ieee80211_local *local,
                                struct sk_buff_head *skbs)
{
        ieee80211_add_pending_skbs_fn(local, skbs, NULL, NULL);
}

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);
        }

        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);
        }

        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);

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)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_tx_queue_params qparam;
        int queue;
        bool use_11b;
        int aCWmin, aCWmax;

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

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

        use_11b = (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ) &&
                 !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE);

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

                switch (queue) {
                case 3: /* AC_BK */
                        qparam.cw_max = aCWmax;
                        qparam.cw_min = aCWmin;
                        qparam.txop = 0;
                        qparam.aifs = 7;
                        break;
                default: /* never happens but let's not leave undefined */
                case 2: /* AC_BE */
                        qparam.cw_max = aCWmax;
                        qparam.cw_min = aCWmin;
                        qparam.txop = 0;
                        qparam.aifs = 3;
                        break;
                case 1: /* 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 0: /* 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;
                }

                qparam.uapsd = false;

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

        /* after reinitialize QoS TX queues setting to default,
         * disable QoS at all */

        if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
                sdata->vif.bss_conf.qos =
                        sdata->vif.type != NL80211_IFTYPE_STATION;
                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->hw.conf.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);
}

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 (!sband) {
                WARN_ON(1);
                sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
        }

        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 *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, bssid, 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);
}

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];

        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) {
                u16 cap = sband->ht_cap.cap;
                __le16 tmp;

                *pos++ = WLAN_EID_HT_CAPABILITY;
                *pos++ = sizeof(struct ieee80211_ht_cap);
                memset(pos, 0, sizeof(struct ieee80211_ht_cap));
                tmp = cpu_to_le16(cap);
                memcpy(pos, &tmp, sizeof(u16));
                pos += sizeof(u16);
                *pos++ = sband->ht_cap.ampdu_factor |
                         (sband->ht_cap.ampdu_density <<
                                IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
                memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
                pos += sizeof(sband->ht_cap.mcs);
                pos += 2 + 4 + 1; /* ext info, BF cap, antsel */
        }

        /*
         * 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;
        }

        return pos - buffer;
}

struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
                                          u8 *dst, u32 ratemask,
                                          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;

        /* 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 = 0;
        else
                chan = ieee80211_frequency_to_channel(
                        local->hw.conf.channel->center_freq);

        buf_len = ieee80211_build_preq_ies(local, buf, ie, ie_len,
                                           local->hw.conf.channel->band,
                                           ratemask, chan);

        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 sk_buff *skb;

        skb = ieee80211_build_probe_req(sdata, dst, ratemask, 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)
{
        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 (!sband) {
                WARN_ON(1);
                sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
        }

        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;
                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);
                for (j = 0; j < num_rates; j++)
                        if (bitrates[j].bitrate == own_rate)
                                supp_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

        /* 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);

        /* 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;
        }

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

        /* add interfaces */
        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->vif);
        }

        /* add STAs back */
        mutex_lock(&local->sta_mtx);
        list_for_each_entry(sta, &local->sta_list, list) {
                if (sta->uploaded) {
                        sdata = sta->sdata;
                        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
                                sdata = container_of(sdata->bss,
                                             struct ieee80211_sub_if_data,
                                             u.ap);

                        WARN_ON(drv_sta_add(local, sdata, &sta->sta));
                }
        }
        mutex_unlock(&local->sta_mtx);

        /* reconfigure tx conf */
        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 < hw->queues; 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;

                switch (sdata->vif.type) {
                case NL80211_IFTYPE_STATION:
                        changed |= BSS_CHANGED_ASSOC;
                        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;
                        /* 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_UNSPECIFIED:
                case NUM_NL80211_IFTYPES:
                case NL80211_IFTYPE_P2P_CLIENT:
                case NL80211_IFTYPE_P2P_GO:
                        WARN_ON(1);
                        break;
                }
        }

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

 wake_up:
        /*
         * 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;
}

/* must hold iflist_mtx */
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;

        lockdep_assert_held(&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_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)
                return;

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

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);

int ieee80211_add_srates_ie(struct ieee80211_vif *vif, struct sk_buff *skb)
{
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        int rate;
        u8 i, rates, *pos;

        sband = local->hw.wiphy->bands[local->hw.conf.channel->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++) {
                rate = sband->bitrates[i].bitrate;
                *pos++ = (u8) (rate / 5);
        }

        return 0;
}

int ieee80211_add_ext_srates_ie(struct ieee80211_vif *vif, struct sk_buff *skb)
{
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_supported_band *sband;
        int rate;
        u8 i, exrates, *pos;

        sband = local->hw.wiphy->bands[local->hw.conf.channel->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++) {
                        rate = sband->bitrates[i].bitrate;
                        *pos++ = (u8) (rate / 5);
                }
        }
        return 0;
}