[MAC80211]: Add debugfs attributes.

[safe/jmp/linux-2.6] / net / mac80211 / ieee80211.c

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/rtnetlink.h>
#include <net/iw_handler.h>
#include <linux/compiler.h>
#include <linux/bitmap.h>
#include <net/cfg80211.h>

#include "ieee80211_common.h"
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"
#include "aes_ccm.h"
#include "ieee80211_led.h"
#include "ieee80211_cfg.h"
#include "debugfs.h"
#include "debugfs_netdev.h"
#include "debugfs_key.h"

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

/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
static const unsigned char rfc1042_header[] =
        { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
static const unsigned char bridge_tunnel_header[] =
        { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };

/* No encapsulation header if EtherType < 0x600 (=length) */
static const unsigned char eapol_header[] =
        { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e };


static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
                                              struct ieee80211_hdr *hdr)
{
        /* Set the sequence number for this frame. */
        hdr->seq_ctrl = cpu_to_le16(sdata->sequence);

        /* Increase the sequence number. */
        sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
}

struct ieee80211_key_conf *
ieee80211_key_data2conf(struct ieee80211_local *local,
                        const struct ieee80211_key *data)
{
        struct ieee80211_key_conf *conf;

        conf = kmalloc(sizeof(*conf) + data->keylen, GFP_ATOMIC);
        if (!conf)
                return NULL;

        conf->hw_key_idx = data->hw_key_idx;
        conf->alg = data->alg;
        conf->keylen = data->keylen;
        conf->flags = 0;
        if (data->force_sw_encrypt)
                conf->flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
        conf->keyidx = data->keyidx;
        if (data->default_tx_key)
                conf->flags |= IEEE80211_KEY_DEFAULT_TX_KEY;
        if (local->default_wep_only)
                conf->flags |= IEEE80211_KEY_DEFAULT_WEP_ONLY;
        memcpy(conf->key, data->key, data->keylen);

        return conf;
}

struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
                                          int idx, size_t key_len, gfp_t flags)
{
        struct ieee80211_key *key;

        key = kzalloc(sizeof(struct ieee80211_key) + key_len, flags);
        if (!key)
                return NULL;
        kref_init(&key->kref);
        return key;
}

static void ieee80211_key_release(struct kref *kref)
{
        struct ieee80211_key *key;

        key = container_of(kref, struct ieee80211_key, kref);
        if (key->alg == ALG_CCMP)
                ieee80211_aes_key_free(key->u.ccmp.tfm);
        ieee80211_debugfs_key_remove(key);
        kfree(key);
}

void ieee80211_key_free(struct ieee80211_key *key)
{
        if (key)
                kref_put(&key->kref, ieee80211_key_release);
}

static int rate_list_match(const int *rate_list, int rate)
{
        int i;

        if (!rate_list)
                return 0;

        for (i = 0; rate_list[i] >= 0; i++)
                if (rate_list[i] == rate)
                        return 1;

        return 0;
}


void ieee80211_prepare_rates(struct ieee80211_local *local,
                             struct ieee80211_hw_mode *mode)
{
        int i;

        for (i = 0; i < mode->num_rates; i++) {
                struct ieee80211_rate *rate = &mode->rates[i];

                rate->flags &= ~(IEEE80211_RATE_SUPPORTED |
                                 IEEE80211_RATE_BASIC);

                if (local->supp_rates[mode->mode]) {
                        if (!rate_list_match(local->supp_rates[mode->mode],
                                             rate->rate))
                                continue;
                }

                rate->flags |= IEEE80211_RATE_SUPPORTED;

                /* Use configured basic rate set if it is available. If not,
                 * use defaults that are sane for most cases. */
                if (local->basic_rates[mode->mode]) {
                        if (rate_list_match(local->basic_rates[mode->mode],
                                            rate->rate))
                                rate->flags |= IEEE80211_RATE_BASIC;
                } else switch (mode->mode) {
                case MODE_IEEE80211A:
                        if (rate->rate == 60 || rate->rate == 120 ||
                            rate->rate == 240)
                                rate->flags |= IEEE80211_RATE_BASIC;
                        break;
                case MODE_IEEE80211B:
                        if (rate->rate == 10 || rate->rate == 20)
                                rate->flags |= IEEE80211_RATE_BASIC;
                        break;
                case MODE_ATHEROS_TURBO:
                        if (rate->rate == 120 || rate->rate == 240 ||
                            rate->rate == 480)
                                rate->flags |= IEEE80211_RATE_BASIC;
                        break;
                case MODE_IEEE80211G:
                        if (rate->rate == 10 || rate->rate == 20 ||
                            rate->rate == 55 || rate->rate == 110)
                                rate->flags |= IEEE80211_RATE_BASIC;
                        break;
                }

                /* Set ERP and MANDATORY flags based on phymode */
                switch (mode->mode) {
                case MODE_IEEE80211A:
                        if (rate->rate == 60 || rate->rate == 120 ||
                            rate->rate == 240)
                                rate->flags |= IEEE80211_RATE_MANDATORY;
                        break;
                case MODE_IEEE80211B:
                        if (rate->rate == 10)
                                rate->flags |= IEEE80211_RATE_MANDATORY;
                        break;
                case MODE_ATHEROS_TURBO:
                        break;
                case MODE_IEEE80211G:
                        if (rate->rate == 10 || rate->rate == 20 ||
                            rate->rate == 55 || rate->rate == 110 ||
                            rate->rate == 60 || rate->rate == 120 ||
                            rate->rate == 240)
                                rate->flags |= IEEE80211_RATE_MANDATORY;
                        break;
                }
                if (ieee80211_is_erp_rate(mode->mode, rate->rate))
                        rate->flags |= IEEE80211_RATE_ERP;
        }
}


static void ieee80211_key_threshold_notify(struct net_device *dev,
                                           struct ieee80211_key *key,
                                           struct sta_info *sta)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct sk_buff *skb;
        struct ieee80211_msg_key_notification *msg;

        /* if no one will get it anyway, don't even allocate it.
         * unlikely because this is only relevant for APs
         * where the device must be open... */
        if (unlikely(!local->apdev))
                return;

        skb = dev_alloc_skb(sizeof(struct ieee80211_frame_info) +
                            sizeof(struct ieee80211_msg_key_notification));
        if (!skb)
                return;

        skb_reserve(skb, sizeof(struct ieee80211_frame_info));
        msg = (struct ieee80211_msg_key_notification *)
                skb_put(skb, sizeof(struct ieee80211_msg_key_notification));
        msg->tx_rx_count = key->tx_rx_count;
        memcpy(msg->ifname, dev->name, IFNAMSIZ);
        if (sta)
                memcpy(msg->addr, sta->addr, ETH_ALEN);
        else
                memset(msg->addr, 0xff, ETH_ALEN);

        key->tx_rx_count = 0;

        ieee80211_rx_mgmt(local, skb, NULL,
                          ieee80211_msg_key_threshold_notification);
}


static u8 * ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
{
        u16 fc;

        if (len < 24)
                return NULL;

        fc = le16_to_cpu(hdr->frame_control);

        switch (fc & IEEE80211_FCTL_FTYPE) {
        case IEEE80211_FTYPE_DATA:
                switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
                case IEEE80211_FCTL_TODS:
                        return hdr->addr1;
                case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
                        return NULL;
                case IEEE80211_FCTL_FROMDS:
                        return hdr->addr2;
                case 0:
                        return hdr->addr3;
                }
                break;
        case IEEE80211_FTYPE_MGMT:
                return hdr->addr3;
        case IEEE80211_FTYPE_CTL:
                if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
                        return hdr->addr1;
                else
                        return NULL;
        }

        return NULL;
}

int ieee80211_get_hdrlen(u16 fc)
{
        int hdrlen = 24;

        switch (fc & IEEE80211_FCTL_FTYPE) {
        case IEEE80211_FTYPE_DATA:
                if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
                        hdrlen = 30; /* Addr4 */
                /*
                 * The QoS Control field is two bytes and its presence is
                 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
                 * hdrlen if that bit is set.
                 * This works by masking out the bit and shifting it to
                 * bit position 1 so the result has the value 0 or 2.
                 */
                hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
                                >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
                break;
        case IEEE80211_FTYPE_CTL:
                /*
                 * ACK and CTS are 10 bytes, all others 16. To see how
                 * to get this condition consider
                 *   subtype mask:   0b0000000011110000 (0x00F0)
                 *   ACK subtype:    0b0000000011010000 (0x00D0)
                 *   CTS subtype:    0b0000000011000000 (0x00C0)
                 *   bits that matter:         ^^^      (0x00E0)
                 *   value of those: 0b0000000011000000 (0x00C0)
                 */
                if ((fc & 0xE0) == 0xC0)
                        hdrlen = 10;
                else
                        hdrlen = 16;
                break;
        }

        return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen);

int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
        const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
        int hdrlen;

        if (unlikely(skb->len < 10))
                return 0;
        hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
        if (unlikely(hdrlen > skb->len))
                return 0;
        return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);

static int ieee80211_get_radiotap_len(struct sk_buff *skb)
{
        struct ieee80211_radiotap_header *hdr =
                (struct ieee80211_radiotap_header *) skb->data;

        return le16_to_cpu(hdr->it_len);
}

#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
static void ieee80211_dump_frame(const char *ifname, const char *title,
                                 const struct sk_buff *skb)
{
        const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        u16 fc;
        int hdrlen;

        printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
        if (skb->len < 4) {
                printk("\n");
                return;
        }

        fc = le16_to_cpu(hdr->frame_control);
        hdrlen = ieee80211_get_hdrlen(fc);
        if (hdrlen > skb->len)
                hdrlen = skb->len;
        if (hdrlen >= 4)
                printk(" FC=0x%04x DUR=0x%04x",
                       fc, le16_to_cpu(hdr->duration_id));
        if (hdrlen >= 10)
                printk(" A1=" MAC_FMT, MAC_ARG(hdr->addr1));
        if (hdrlen >= 16)
                printk(" A2=" MAC_FMT, MAC_ARG(hdr->addr2));
        if (hdrlen >= 24)
                printk(" A3=" MAC_FMT, MAC_ARG(hdr->addr3));
        if (hdrlen >= 30)
                printk(" A4=" MAC_FMT, MAC_ARG(hdr->addr4));
        printk("\n");
}
#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
static inline void ieee80211_dump_frame(const char *ifname, const char *title,
                                        struct sk_buff *skb)
{
}
#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */


static int ieee80211_is_eapol(const struct sk_buff *skb)
{
        const struct ieee80211_hdr *hdr;
        u16 fc;
        int hdrlen;

        if (unlikely(skb->len < 10))
                return 0;

        hdr = (const struct ieee80211_hdr *) skb->data;
        fc = le16_to_cpu(hdr->frame_control);

        if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
                return 0;

        hdrlen = ieee80211_get_hdrlen(fc);

        if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
                     memcmp(skb->data + hdrlen, eapol_header,
                            sizeof(eapol_header)) == 0))
                return 1;

        return 0;
}


static ieee80211_txrx_result
ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
{
        struct rate_control_extra extra;

        memset(&extra, 0, sizeof(extra));
        extra.mode = tx->u.tx.mode;
        extra.mgmt_data = tx->sdata &&
                tx->sdata->type == IEEE80211_IF_TYPE_MGMT;
        extra.ethertype = tx->ethertype;

        tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
                                              &extra);
        if (unlikely(extra.probe != NULL)) {
                tx->u.tx.control->flags |= IEEE80211_TXCTL_RATE_CTRL_PROBE;
                tx->u.tx.probe_last_frag = 1;
                tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
                tx->u.tx.rate = extra.probe;
        } else {
                tx->u.tx.control->alt_retry_rate = -1;
        }
        if (!tx->u.tx.rate)
                return TXRX_DROP;
        if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
            tx->local->cts_protect_erp_frames && tx->fragmented &&
            extra.nonerp) {
                tx->u.tx.last_frag_rate = tx->u.tx.rate;
                tx->u.tx.probe_last_frag = extra.probe ? 1 : 0;

                tx->u.tx.rate = extra.nonerp;
                tx->u.tx.control->rate = extra.nonerp;
                tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
        } else {
                tx->u.tx.last_frag_rate = tx->u.tx.rate;
                tx->u.tx.control->rate = tx->u.tx.rate;
        }
        tx->u.tx.control->tx_rate = tx->u.tx.rate->val;
        if ((tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) &&
            tx->local->short_preamble &&
            (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
                tx->u.tx.short_preamble = 1;
                tx->u.tx.control->tx_rate = tx->u.tx.rate->val2;
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
{
        if (tx->sta)
                tx->u.tx.control->key_idx = tx->sta->key_idx_compression;
        else
                tx->u.tx.control->key_idx = HW_KEY_IDX_INVALID;

        if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
                tx->key = NULL;
        else if (tx->sta && tx->sta->key)
                tx->key = tx->sta->key;
        else if (tx->sdata->default_key)
                tx->key = tx->sdata->default_key;
        else if (tx->sdata->drop_unencrypted &&
                 !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
                I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
                return TXRX_DROP;
        } else
                tx->key = NULL;

        if (tx->key) {
                tx->key->tx_rx_count++;
                if (unlikely(tx->local->key_tx_rx_threshold &&
                             tx->key->tx_rx_count >
                             tx->local->key_tx_rx_threshold)) {
                        ieee80211_key_threshold_notify(tx->dev, tx->key,
                                                       tx->sta);
                }
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_tx_h_fragment(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
        size_t hdrlen, per_fragm, num_fragm, payload_len, left;
        struct sk_buff **frags, *first, *frag;
        int i;
        u16 seq;
        u8 *pos;
        int frag_threshold = tx->local->fragmentation_threshold;

        if (!tx->fragmented)
                return TXRX_CONTINUE;

        first = tx->skb;

        hdrlen = ieee80211_get_hdrlen(tx->fc);
        payload_len = first->len - hdrlen;
        per_fragm = frag_threshold - hdrlen - FCS_LEN;
        num_fragm = (payload_len + per_fragm - 1) / per_fragm;

        frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
        if (!frags)
                goto fail;

        hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
        seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
        pos = first->data + hdrlen + per_fragm;
        left = payload_len - per_fragm;
        for (i = 0; i < num_fragm - 1; i++) {
                struct ieee80211_hdr *fhdr;
                size_t copylen;

                if (left <= 0)
                        goto fail;

                /* reserve enough extra head and tail room for possible
                 * encryption */
                frag = frags[i] =
                        dev_alloc_skb(tx->local->hw.extra_tx_headroom +
                                      frag_threshold +
                                      IEEE80211_ENCRYPT_HEADROOM +
                                      IEEE80211_ENCRYPT_TAILROOM);
                if (!frag)
                        goto fail;
                /* Make sure that all fragments use the same priority so
                 * that they end up using the same TX queue */
                frag->priority = first->priority;
                skb_reserve(frag, tx->local->hw.extra_tx_headroom +
                        IEEE80211_ENCRYPT_HEADROOM);
                fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
                memcpy(fhdr, first->data, hdrlen);
                if (i == num_fragm - 2)
                        fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
                fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
                copylen = left > per_fragm ? per_fragm : left;
                memcpy(skb_put(frag, copylen), pos, copylen);

                pos += copylen;
                left -= copylen;
        }
        skb_trim(first, hdrlen + per_fragm);

        tx->u.tx.num_extra_frag = num_fragm - 1;
        tx->u.tx.extra_frag = frags;

        return TXRX_CONTINUE;

 fail:
        printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
        if (frags) {
                for (i = 0; i < num_fragm - 1; i++)
                        if (frags[i])
                                dev_kfree_skb(frags[i]);
                kfree(frags);
        }
        I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
        return TXRX_DROP;
}


static int wep_encrypt_skb(struct ieee80211_txrx_data *tx, struct sk_buff *skb)
{
        if (tx->key->force_sw_encrypt) {
                if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
                        return -1;
        } else {
                tx->u.tx.control->key_idx = tx->key->hw_key_idx;
                if (tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
                        if (ieee80211_wep_add_iv(tx->local, skb, tx->key) ==
                            NULL)
                                return -1;
                }
        }
        return 0;
}


void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;

        hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
        if (tx->u.tx.extra_frag) {
                struct ieee80211_hdr *fhdr;
                int i;
                for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
                        fhdr = (struct ieee80211_hdr *)
                                tx->u.tx.extra_frag[i]->data;
                        fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
                }
        }
}


static ieee80211_txrx_result
ieee80211_tx_h_wep_encrypt(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
        u16 fc;

        fc = le16_to_cpu(hdr->frame_control);

        if (!tx->key || tx->key->alg != ALG_WEP ||
            ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
             ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
              (fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
                return TXRX_CONTINUE;

        tx->u.tx.control->iv_len = WEP_IV_LEN;
        tx->u.tx.control->icv_len = WEP_ICV_LEN;
        ieee80211_tx_set_iswep(tx);

        if (wep_encrypt_skb(tx, tx->skb) < 0) {
                I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
                return TXRX_DROP;
        }

        if (tx->u.tx.extra_frag) {
                int i;
                for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
                        if (wep_encrypt_skb(tx, tx->u.tx.extra_frag[i]) < 0) {
                                I802_DEBUG_INC(tx->local->
                                               tx_handlers_drop_wep);
                                return TXRX_DROP;
                        }
                }
        }

        return TXRX_CONTINUE;
}


static 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.phymode == MODE_IEEE80211A || erp ||
            local->hw.conf.phymode == MODE_ATHEROS_TURBO) {
                /*
                 * 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
                 */
                /* FIX: Atheros Turbo may have different (shorter) duration? */
                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,
                                        size_t frame_len, int rate)
{
        struct ieee80211_local *local = hw_to_local(hw);
        u16 dur;
        int erp;

        erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
        dur = ieee80211_frame_duration(local, frame_len, rate,
                                       erp, local->short_preamble);

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


static u16 ieee80211_duration(struct ieee80211_txrx_data *tx, int group_addr,
                              int next_frag_len)
{
        int rate, mrate, erp, dur, i;
        struct ieee80211_rate *txrate = tx->u.tx.rate;
        struct ieee80211_local *local = tx->local;
        struct ieee80211_hw_mode *mode = tx->u.tx.mode;

        erp = txrate->flags & IEEE80211_RATE_ERP;

        /*
         * data and mgmt (except PS Poll):
         * - during CFP: 32768
         * - during contention period:
         *   if addr1 is group address: 0
         *   if more fragments = 0 and addr1 is individual address: time to
         *      transmit one ACK plus SIFS
         *   if more fragments = 1 and addr1 is individual address: time to
         *      transmit next fragment plus 2 x ACK plus 3 x SIFS
         *
         * IEEE 802.11, 9.6:
         * - control response frame (CTS or ACK) shall be transmitted using the
         *   same rate as the immediately previous frame in the frame exchange
         *   sequence, if this rate belongs to the PHY mandatory rates, or else
         *   at the highest possible rate belonging to the PHY rates in the
         *   BSSBasicRateSet
         */

        if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
                /* TODO: These control frames are not currently sent by
                 * 80211.o, but should they be implemented, this function
                 * needs to be updated to support duration field calculation.
                 *
                 * RTS: time needed to transmit pending data/mgmt frame plus
                 *    one CTS frame plus one ACK frame plus 3 x SIFS
                 * CTS: duration of immediately previous RTS minus time
                 *    required to transmit CTS and its SIFS
                 * ACK: 0 if immediately previous directed data/mgmt had
                 *    more=0, with more=1 duration in ACK frame is duration
                 *    from previous frame minus time needed to transmit ACK
                 *    and its SIFS
                 * PS Poll: BIT(15) | BIT(14) | aid
                 */
                return 0;
        }

        /* data/mgmt */
        if (0 /* FIX: data/mgmt during CFP */)
                return 32768;

        if (group_addr) /* Group address as the destination - no ACK */
                return 0;

        /* Individual destination address:
         * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
         * CTS and ACK frames shall be transmitted using the highest rate in
         * basic rate set that is less than or equal to the rate of the
         * immediately previous frame and that is using the same modulation
         * (CCK or OFDM). If no basic rate set matches with these requirements,
         * the highest mandatory rate of the PHY that is less than or equal to
         * the rate of the previous frame is used.
         * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
         */
        rate = -1;
        mrate = 10; /* use 1 Mbps if everything fails */
        for (i = 0; i < mode->num_rates; i++) {
                struct ieee80211_rate *r = &mode->rates[i];
                if (r->rate > txrate->rate)
                        break;

                if (IEEE80211_RATE_MODULATION(txrate->flags) !=
                    IEEE80211_RATE_MODULATION(r->flags))
                        continue;

                if (r->flags & IEEE80211_RATE_BASIC)
                        rate = r->rate;
                else if (r->flags & IEEE80211_RATE_MANDATORY)
                        mrate = r->rate;
        }
        if (rate == -1) {
                /* No matching basic rate found; use highest suitable mandatory
                 * PHY rate */
                rate = mrate;
        }

        /* Time needed to transmit ACK
         * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
         * to closest integer */

        dur = ieee80211_frame_duration(local, 10, rate, erp,
                                       local->short_preamble);

        if (next_frag_len) {
                /* Frame is fragmented: duration increases with time needed to
                 * transmit next fragment plus ACK and 2 x SIFS. */
                dur *= 2; /* ACK + SIFS */
                /* next fragment */
                dur += ieee80211_frame_duration(local, next_frag_len,
                                                txrate->rate, erp,
                                                local->short_preamble);
        }

        return dur;
}


static ieee80211_txrx_result
ieee80211_tx_h_misc(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
        u16 dur;
        struct ieee80211_tx_control *control = tx->u.tx.control;
        struct ieee80211_hw_mode *mode = tx->u.tx.mode;

        if (!is_multicast_ether_addr(hdr->addr1)) {
                if (tx->skb->len + FCS_LEN > tx->local->rts_threshold &&
                    tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD) {
                        control->flags |= IEEE80211_TXCTL_USE_RTS_CTS;
                        control->retry_limit =
                                tx->local->long_retry_limit;
                } else {
                        control->retry_limit =
                                tx->local->short_retry_limit;
                }
        } else {
                control->retry_limit = 1;
        }

        if (tx->fragmented) {
                /* Do not use multiple retry rates when sending fragmented
                 * frames.
                 * TODO: The last fragment could still use multiple retry
                 * rates. */
                control->alt_retry_rate = -1;
        }

        /* Use CTS protection for unicast frames sent using extended rates if
         * there are associated non-ERP stations and RTS/CTS is not configured
         * for the frame. */
        if (mode->mode == MODE_IEEE80211G &&
            (tx->u.tx.rate->flags & IEEE80211_RATE_ERP) &&
            tx->u.tx.unicast &&
            tx->local->cts_protect_erp_frames &&
            !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
                control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;

        /* Setup duration field for the first fragment of the frame. Duration
         * for remaining fragments will be updated when they are being sent
         * to low-level driver in ieee80211_tx(). */
        dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
                                 tx->fragmented ? tx->u.tx.extra_frag[0]->len :
                                 0);
        hdr->duration_id = cpu_to_le16(dur);

        if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
            (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
                struct ieee80211_rate *rate;

                /* Do not use multiple retry rates when using RTS/CTS */
                control->alt_retry_rate = -1;

                /* Use min(data rate, max base rate) as CTS/RTS rate */
                rate = tx->u.tx.rate;
                while (rate > mode->rates &&
                       !(rate->flags & IEEE80211_RATE_BASIC))
                        rate--;

                control->rts_cts_rate = rate->val;
                control->rts_rate = rate;
        }

        if (tx->sta) {
                tx->sta->tx_packets++;
                tx->sta->tx_fragments++;
                tx->sta->tx_bytes += tx->skb->len;
                if (tx->u.tx.extra_frag) {
                        int i;
                        tx->sta->tx_fragments += tx->u.tx.num_extra_frag;
                        for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
                                tx->sta->tx_bytes +=
                                        tx->u.tx.extra_frag[i]->len;
                        }
                }
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_tx_h_check_assoc(struct ieee80211_txrx_data *tx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        struct sk_buff *skb = tx->skb;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
        u32 sta_flags;

        if (unlikely(tx->local->sta_scanning != 0) &&
            ((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
             (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
                return TXRX_DROP;

        if (tx->u.tx.ps_buffered)
                return TXRX_CONTINUE;

        sta_flags = tx->sta ? tx->sta->flags : 0;

        if (likely(tx->u.tx.unicast)) {
                if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
                             tx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
                             (tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                        printk(KERN_DEBUG "%s: dropped data frame to not "
                               "associated station " MAC_FMT "\n",
                               tx->dev->name, MAC_ARG(hdr->addr1));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
                        I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
                        return TXRX_DROP;
                }
        } else {
                if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
                             tx->local->num_sta == 0 &&
                             !tx->local->allow_broadcast_always &&
                             tx->sdata->type != IEEE80211_IF_TYPE_IBSS)) {
                        /*
                         * No associated STAs - no need to send multicast
                         * frames.
                         */
                        return TXRX_DROP;
                }
                return TXRX_CONTINUE;
        }

        if (unlikely(!tx->u.tx.mgmt_interface && tx->sdata->ieee802_1x &&
                     !(sta_flags & WLAN_STA_AUTHORIZED))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                printk(KERN_DEBUG "%s: dropped frame to " MAC_FMT
                       " (unauthorized port)\n", tx->dev->name,
                       MAC_ARG(hdr->addr1));
#endif
                I802_DEBUG_INC(tx->local->tx_handlers_drop_unauth_port);
                return TXRX_DROP;
        }

        return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_tx_h_sequence(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;

        if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
                ieee80211_include_sequence(tx->sdata, hdr);

        return TXRX_CONTINUE;
}

/* This function is called whenever the AP is about to exceed the maximum limit
 * of buffered frames for power saving STAs. This situation should not really
 * happen often during normal operation, so dropping the oldest buffered packet
 * from each queue should be OK to make some room for new frames. */
static void purge_old_ps_buffers(struct ieee80211_local *local)
{
        int total = 0, purged = 0;
        struct sk_buff *skb;
        struct ieee80211_sub_if_data *sdata;
        struct sta_info *sta;

        read_lock(&local->sub_if_lock);
        list_for_each_entry(sdata, &local->sub_if_list, list) {
                struct ieee80211_if_ap *ap;
                if (sdata->dev == local->mdev ||
                    sdata->type != IEEE80211_IF_TYPE_AP)
                        continue;
                ap = &sdata->u.ap;
                skb = skb_dequeue(&ap->ps_bc_buf);
                if (skb) {
                        purged++;
                        dev_kfree_skb(skb);
                }
                total += skb_queue_len(&ap->ps_bc_buf);
        }
        read_unlock(&local->sub_if_lock);

        spin_lock_bh(&local->sta_lock);
        list_for_each_entry(sta, &local->sta_list, list) {
                skb = skb_dequeue(&sta->ps_tx_buf);
                if (skb) {
                        purged++;
                        dev_kfree_skb(skb);
                }
                total += skb_queue_len(&sta->ps_tx_buf);
        }
        spin_unlock_bh(&local->sta_lock);

        local->total_ps_buffered = total;
        printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
               local->mdev->name, purged);
}


static inline ieee80211_txrx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_txrx_data *tx)
{
        /* broadcast/multicast frame */
        /* If any of the associated stations is in power save mode,
         * the frame is buffered to be sent after DTIM beacon frame */
        if ((tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) &&
            tx->sdata->type != IEEE80211_IF_TYPE_WDS &&
            tx->sdata->bss && atomic_read(&tx->sdata->bss->num_sta_ps) &&
            !(tx->fc & IEEE80211_FCTL_ORDER)) {
                if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
                        purge_old_ps_buffers(tx->local);
                if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
                    AP_MAX_BC_BUFFER) {
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "%s: BC TX buffer full - "
                                       "dropping the oldest frame\n",
                                       tx->dev->name);
                        }
                        dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
                } else
                        tx->local->total_ps_buffered++;
                skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
                return TXRX_QUEUED;
        }

        return TXRX_CONTINUE;
}


static inline ieee80211_txrx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
{
        struct sta_info *sta = tx->sta;

        if (unlikely(!sta ||
                     ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
                      (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
                return TXRX_CONTINUE;

        if (unlikely((sta->flags & WLAN_STA_PS) && !sta->pspoll)) {
                struct ieee80211_tx_packet_data *pkt_data;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
                printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS buffer (entries "
                       "before %d)\n",
                       MAC_ARG(sta->addr), sta->aid,
                       skb_queue_len(&sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
                sta->flags |= WLAN_STA_TIM;
                if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
                        purge_old_ps_buffers(tx->local);
                if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
                        struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "%s: STA " MAC_FMT " TX "
                                       "buffer full - dropping oldest frame\n",
                                       tx->dev->name, MAC_ARG(sta->addr));
                        }
                        dev_kfree_skb(old);
                } else
                        tx->local->total_ps_buffered++;
                /* Queue frame to be sent after STA sends an PS Poll frame */
                if (skb_queue_empty(&sta->ps_tx_buf)) {
                        if (tx->local->ops->set_tim)
                                tx->local->ops->set_tim(local_to_hw(tx->local),
                                                       sta->aid, 1);
                        if (tx->sdata->bss)
                                bss_tim_set(tx->local, tx->sdata->bss, sta->aid);
                }
                pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
                pkt_data->jiffies = jiffies;
                skb_queue_tail(&sta->ps_tx_buf, tx->skb);
                return TXRX_QUEUED;
        }
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        else if (unlikely(sta->flags & WLAN_STA_PS)) {
                printk(KERN_DEBUG "%s: STA " MAC_FMT " in PS mode, but pspoll "
                       "set -> send frame\n", tx->dev->name,
                       MAC_ARG(sta->addr));
        }
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
        sta->pspoll = 0;

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
{
        if (unlikely(tx->u.tx.ps_buffered))
                return TXRX_CONTINUE;

        if (tx->u.tx.unicast)
                return ieee80211_tx_h_unicast_ps_buf(tx);
        else
                return ieee80211_tx_h_multicast_ps_buf(tx);
}


static void inline
__ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
                       struct sk_buff *skb,
                       struct net_device *dev,
                       struct ieee80211_tx_control *control)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        int hdrlen;

        memset(tx, 0, sizeof(*tx));
        tx->skb = skb;
        tx->dev = dev; /* use original interface */
        tx->local = local;
        tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        tx->sta = sta_info_get(local, hdr->addr1);
        tx->fc = le16_to_cpu(hdr->frame_control);
        control->power_level = local->hw.conf.power_level;
        tx->u.tx.control = control;
        tx->u.tx.unicast = !is_multicast_ether_addr(hdr->addr1);
        if (is_multicast_ether_addr(hdr->addr1))
                control->flags |= IEEE80211_TXCTL_NO_ACK;
        else
                control->flags &= ~IEEE80211_TXCTL_NO_ACK;
        tx->fragmented = local->fragmentation_threshold <
                IEEE80211_MAX_FRAG_THRESHOLD && tx->u.tx.unicast &&
                skb->len + FCS_LEN > local->fragmentation_threshold &&
                (!local->ops->set_frag_threshold);
        if (!tx->sta)
                control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
        else if (tx->sta->clear_dst_mask) {
                control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
                tx->sta->clear_dst_mask = 0;
        }
        control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
        if (local->sta_antenna_sel != STA_ANTENNA_SEL_AUTO && tx->sta)
                control->antenna_sel_tx = tx->sta->antenna_sel_tx;
        hdrlen = ieee80211_get_hdrlen(tx->fc);
        if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
                u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
                tx->ethertype = (pos[0] << 8) | pos[1];
        }
        control->flags |= IEEE80211_TXCTL_FIRST_FRAGMENT;

}

static int inline is_ieee80211_device(struct net_device *dev,
                                      struct net_device *master)
{
        return (wdev_priv(dev->ieee80211_ptr) ==
                wdev_priv(master->ieee80211_ptr));
}

/* Device in tx->dev has a reference added; use dev_put(tx->dev) when
 * finished with it. */
static int inline ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
                                       struct sk_buff *skb,
                                       struct net_device *mdev,
                                       struct ieee80211_tx_control *control)
{
        struct ieee80211_tx_packet_data *pkt_data;
        struct net_device *dev;

        pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
        dev = dev_get_by_index(pkt_data->ifindex);
        if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
                dev_put(dev);
                dev = NULL;
        }
        if (unlikely(!dev))
                return -ENODEV;
        __ieee80211_tx_prepare(tx, skb, dev, control);
        return 0;
}

static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
                                            int queue)
{
        return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}

static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
                                            int queue)
{
        return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
}

#define IEEE80211_TX_OK         0
#define IEEE80211_TX_AGAIN      1
#define IEEE80211_TX_FRAG_AGAIN 2

static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
                          struct ieee80211_txrx_data *tx)
{
        struct ieee80211_tx_control *control = tx->u.tx.control;
        int ret, i;

        if (!ieee80211_qdisc_installed(local->mdev) &&
            __ieee80211_queue_stopped(local, 0)) {
                netif_stop_queue(local->mdev);
                return IEEE80211_TX_AGAIN;
        }
        if (skb) {
                ieee80211_dump_frame(local->mdev->name, "TX to low-level driver", skb);
                ret = local->ops->tx(local_to_hw(local), skb, control);
                if (ret)
                        return IEEE80211_TX_AGAIN;
                local->mdev->trans_start = jiffies;
                ieee80211_led_tx(local, 1);
        }
        if (tx->u.tx.extra_frag) {
                control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
                                    IEEE80211_TXCTL_USE_CTS_PROTECT |
                                    IEEE80211_TXCTL_CLEAR_DST_MASK |
                                    IEEE80211_TXCTL_FIRST_FRAGMENT);
                for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
                        if (!tx->u.tx.extra_frag[i])
                                continue;
                        if (__ieee80211_queue_stopped(local, control->queue))
                                return IEEE80211_TX_FRAG_AGAIN;
                        if (i == tx->u.tx.num_extra_frag) {
                                control->tx_rate = tx->u.tx.last_frag_hwrate;
                                control->rate = tx->u.tx.last_frag_rate;
                                if (tx->u.tx.probe_last_frag)
                                        control->flags |=
                                                IEEE80211_TXCTL_RATE_CTRL_PROBE;
                                else
                                        control->flags &=
                                                ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
                        }

                        ieee80211_dump_frame(local->mdev->name,
                                             "TX to low-level driver",
                                             tx->u.tx.extra_frag[i]);
                        ret = local->ops->tx(local_to_hw(local),
                                            tx->u.tx.extra_frag[i],
                                            control);
                        if (ret)
                                return IEEE80211_TX_FRAG_AGAIN;
                        local->mdev->trans_start = jiffies;
                        ieee80211_led_tx(local, 1);
                        tx->u.tx.extra_frag[i] = NULL;
                }
                kfree(tx->u.tx.extra_frag);
                tx->u.tx.extra_frag = NULL;
        }
        return IEEE80211_TX_OK;
}

static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
                        struct ieee80211_tx_control *control, int mgmt)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct sta_info *sta;
        ieee80211_tx_handler *handler;
        struct ieee80211_txrx_data tx;
        ieee80211_txrx_result res = TXRX_DROP;
        int ret, i;

        WARN_ON(__ieee80211_queue_pending(local, control->queue));

        if (unlikely(skb->len < 10)) {
                dev_kfree_skb(skb);
                return 0;
        }

        __ieee80211_tx_prepare(&tx, skb, dev, control);
        sta = tx.sta;
        tx.u.tx.mgmt_interface = mgmt;
        tx.u.tx.mode = local->hw.conf.mode;

        for (handler = local->tx_handlers; *handler != NULL; handler++) {
                res = (*handler)(&tx);
                if (res != TXRX_CONTINUE)
                        break;
        }

        skb = tx.skb; /* handlers are allowed to change skb */

        if (sta)
                sta_info_put(sta);

        if (unlikely(res == TXRX_DROP)) {
                I802_DEBUG_INC(local->tx_handlers_drop);
                goto drop;
        }

        if (unlikely(res == TXRX_QUEUED)) {
                I802_DEBUG_INC(local->tx_handlers_queued);
                return 0;
        }

        if (tx.u.tx.extra_frag) {
                for (i = 0; i < tx.u.tx.num_extra_frag; i++) {
                        int next_len, dur;
                        struct ieee80211_hdr *hdr =
                                (struct ieee80211_hdr *)
                                tx.u.tx.extra_frag[i]->data;

                        if (i + 1 < tx.u.tx.num_extra_frag) {
                                next_len = tx.u.tx.extra_frag[i + 1]->len;
                        } else {
                                next_len = 0;
                                tx.u.tx.rate = tx.u.tx.last_frag_rate;
                                tx.u.tx.last_frag_hwrate = tx.u.tx.rate->val;
                        }
                        dur = ieee80211_duration(&tx, 0, next_len);
                        hdr->duration_id = cpu_to_le16(dur);
                }
        }

retry:
        ret = __ieee80211_tx(local, skb, &tx);
        if (ret) {
                struct ieee80211_tx_stored_packet *store =
                        &local->pending_packet[control->queue];

                if (ret == IEEE80211_TX_FRAG_AGAIN)
                        skb = NULL;
                set_bit(IEEE80211_LINK_STATE_PENDING,
                        &local->state[control->queue]);
                smp_mb();
                /* When the driver gets out of buffers during sending of
                 * fragments and calls ieee80211_stop_queue, there is
                 * a small window between IEEE80211_LINK_STATE_XOFF and
                 * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
                 * gets available in that window (i.e. driver calls
                 * ieee80211_wake_queue), we would end up with ieee80211_tx
                 * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
                 * continuing transmitting here when that situation is
                 * possible to have happened. */
                if (!__ieee80211_queue_stopped(local, control->queue)) {
                        clear_bit(IEEE80211_LINK_STATE_PENDING,
                                  &local->state[control->queue]);
                        goto retry;
                }
                memcpy(&store->control, control,
                       sizeof(struct ieee80211_tx_control));
                store->skb = skb;
                store->extra_frag = tx.u.tx.extra_frag;
                store->num_extra_frag = tx.u.tx.num_extra_frag;
                store->last_frag_hwrate = tx.u.tx.last_frag_hwrate;
                store->last_frag_rate = tx.u.tx.last_frag_rate;
                store->last_frag_rate_ctrl_probe = tx.u.tx.probe_last_frag;
        }
        return 0;

 drop:
        if (skb)
                dev_kfree_skb(skb);
        for (i = 0; i < tx.u.tx.num_extra_frag; i++)
                if (tx.u.tx.extra_frag[i])
                        dev_kfree_skb(tx.u.tx.extra_frag[i]);
        kfree(tx.u.tx.extra_frag);
        return 0;
}

static void ieee80211_tx_pending(unsigned long data)
{
        struct ieee80211_local *local = (struct ieee80211_local *)data;
        struct net_device *dev = local->mdev;
        struct ieee80211_tx_stored_packet *store;
        struct ieee80211_txrx_data tx;
        int i, ret, reschedule = 0;

        netif_tx_lock_bh(dev);
        for (i = 0; i < local->hw.queues; i++) {
                if (__ieee80211_queue_stopped(local, i))
                        continue;
                if (!__ieee80211_queue_pending(local, i)) {
                        reschedule = 1;
                        continue;
                }
                store = &local->pending_packet[i];
                tx.u.tx.control = &store->control;
                tx.u.tx.extra_frag = store->extra_frag;
                tx.u.tx.num_extra_frag = store->num_extra_frag;
                tx.u.tx.last_frag_hwrate = store->last_frag_hwrate;
                tx.u.tx.last_frag_rate = store->last_frag_rate;
                tx.u.tx.probe_last_frag = store->last_frag_rate_ctrl_probe;
                ret = __ieee80211_tx(local, store->skb, &tx);
                if (ret) {
                        if (ret == IEEE80211_TX_FRAG_AGAIN)
                                store->skb = NULL;
                } else {
                        clear_bit(IEEE80211_LINK_STATE_PENDING,
                                  &local->state[i]);
                        reschedule = 1;
                }
        }
        netif_tx_unlock_bh(dev);
        if (reschedule) {
                if (!ieee80211_qdisc_installed(dev)) {
                        if (!__ieee80211_queue_stopped(local, 0))
                                netif_wake_queue(dev);
                } else
                        netif_schedule(dev);
        }
}

static void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
        int i, j;
        struct ieee80211_tx_stored_packet *store;

        for (i = 0; i < local->hw.queues; i++) {
                if (!__ieee80211_queue_pending(local, i))
                        continue;
                store = &local->pending_packet[i];
                kfree_skb(store->skb);
                for (j = 0; j < store->num_extra_frag; j++)
                        kfree_skb(store->extra_frag[j]);
                kfree(store->extra_frag);
                clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
        }
}

static int ieee80211_master_start_xmit(struct sk_buff *skb,
                                       struct net_device *dev)
{
        struct ieee80211_tx_control control;
        struct ieee80211_tx_packet_data *pkt_data;
        struct net_device *odev = NULL;
        struct ieee80211_sub_if_data *osdata;
        int headroom;
        int ret;

        /*
         * copy control out of the skb so other people can use skb->cb
         */
        pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
        memset(&control, 0, sizeof(struct ieee80211_tx_control));

        if (pkt_data->ifindex)
                odev = dev_get_by_index(pkt_data->ifindex);
        if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
                dev_put(odev);
                odev = NULL;
        }
        if (unlikely(!odev)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
                       "originating device\n", dev->name);
#endif
                dev_kfree_skb(skb);
                return 0;
        }
        osdata = IEEE80211_DEV_TO_SUB_IF(odev);

        headroom = osdata->local->hw.extra_tx_headroom +
                IEEE80211_ENCRYPT_HEADROOM;
        if (skb_headroom(skb) < headroom) {
                if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
                        dev_kfree_skb(skb);
                        return 0;
                }
        }

        control.ifindex = odev->ifindex;
        control.type = osdata->type;
        if (pkt_data->req_tx_status)
                control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
        if (pkt_data->do_not_encrypt)
                control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
        if (pkt_data->requeue)
                control.flags |= IEEE80211_TXCTL_REQUEUE;
        control.queue = pkt_data->queue;

        ret = ieee80211_tx(odev, skb, &control,
                           control.type == IEEE80211_IF_TYPE_MGMT);
        dev_put(odev);

        return ret;
}


/**
 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
 * subinterfaces (wlan#, WDS, and VLAN interfaces)
 * @skb: packet to be sent
 * @dev: incoming interface
 *
 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
 * not be freed, and caller is responsible for either retrying later or freeing
 * skb).
 *
 * This function takes in an Ethernet header and encapsulates it with suitable
 * IEEE 802.11 header based on which interface the packet is coming in. The
 * encapsulated packet will then be passed to master interface, wlan#.11, for
 * transmission (through low-level driver).
 */
static int ieee80211_subif_start_xmit(struct sk_buff *skb,
                                      struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_tx_packet_data *pkt_data;
        struct ieee80211_sub_if_data *sdata;
        int ret = 1, head_need;
        u16 ethertype, hdrlen, fc;
        struct ieee80211_hdr hdr;
        const u8 *encaps_data;
        int encaps_len, skip_header_bytes;
        int nh_pos, h_pos, no_encrypt = 0;
        struct sta_info *sta;

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        if (unlikely(skb->len < ETH_HLEN)) {
                printk(KERN_DEBUG "%s: short skb (len=%d)\n",
                       dev->name, skb->len);
                ret = 0;
                goto fail;
        }

        nh_pos = skb_network_header(skb) - skb->data;
        h_pos = skb_transport_header(skb) - skb->data;

        /* convert Ethernet header to proper 802.11 header (based on
         * operation mode) */
        ethertype = (skb->data[12] << 8) | skb->data[13];
        /* TODO: handling for 802.1x authorized/unauthorized port */
        fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;

        if (likely(sdata->type == IEEE80211_IF_TYPE_AP ||
                   sdata->type == IEEE80211_IF_TYPE_VLAN)) {
                fc |= IEEE80211_FCTL_FROMDS;
                /* DA BSSID SA */
                memcpy(hdr.addr1, skb->data, ETH_ALEN);
                memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
                memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
                hdrlen = 24;
        } else if (sdata->type == IEEE80211_IF_TYPE_WDS) {
                fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
                /* RA TA DA SA */
                memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
                memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
                memcpy(hdr.addr3, skb->data, ETH_ALEN);
                memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
                hdrlen = 30;
        } else if (sdata->type == IEEE80211_IF_TYPE_STA) {
                fc |= IEEE80211_FCTL_TODS;
                /* BSSID SA DA */
                memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
                memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
                memcpy(hdr.addr3, skb->data, ETH_ALEN);
                hdrlen = 24;
        } else if (sdata->type == IEEE80211_IF_TYPE_IBSS) {
                /* DA SA BSSID */
                memcpy(hdr.addr1, skb->data, ETH_ALEN);
                memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
                memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
                hdrlen = 24;
        } else {
                ret = 0;
                goto fail;
        }

        /* receiver is QoS enabled, use a QoS type frame */
        sta = sta_info_get(local, hdr.addr1);
        if (sta) {
                if (sta->flags & WLAN_STA_WME) {
                        fc |= IEEE80211_STYPE_QOS_DATA;
                        hdrlen += 2;
                }
                sta_info_put(sta);
        }

        hdr.frame_control = cpu_to_le16(fc);
        hdr.duration_id = 0;
        hdr.seq_ctrl = 0;

        skip_header_bytes = ETH_HLEN;
        if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
                encaps_data = bridge_tunnel_header;
                encaps_len = sizeof(bridge_tunnel_header);
                skip_header_bytes -= 2;
        } else if (ethertype >= 0x600) {
                encaps_data = rfc1042_header;
                encaps_len = sizeof(rfc1042_header);
                skip_header_bytes -= 2;
        } else {
                encaps_data = NULL;
                encaps_len = 0;
        }

        skb_pull(skb, skip_header_bytes);
        nh_pos -= skip_header_bytes;
        h_pos -= skip_header_bytes;

        /* TODO: implement support for fragments so that there is no need to
         * reallocate and copy payload; it might be enough to support one
         * extra fragment that would be copied in the beginning of the frame
         * data.. anyway, it would be nice to include this into skb structure
         * somehow
         *
         * There are few options for this:
         * use skb->cb as an extra space for 802.11 header
         * allocate new buffer if not enough headroom
         * make sure that there is enough headroom in every skb by increasing
         * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
         * alloc_skb() (net/core/skbuff.c)
         */
        head_need = hdrlen + encaps_len + local->hw.extra_tx_headroom;
        head_need -= skb_headroom(skb);

        /* We are going to modify skb data, so make a copy of it if happens to
         * be cloned. This could happen, e.g., with Linux bridge code passing
         * us broadcast frames. */

        if (head_need > 0 || skb_cloned(skb)) {
#if 0
                printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
                       "of headroom\n", dev->name, head_need);
#endif

                if (skb_cloned(skb))
                        I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
                else
                        I802_DEBUG_INC(local->tx_expand_skb_head);
                /* Since we have to reallocate the buffer, make sure that there
                 * is enough room for possible WEP IV/ICV and TKIP (8 bytes
                 * before payload and 12 after). */
                if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
                                     12, GFP_ATOMIC)) {
                        printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
                               "\n", dev->name);
                        goto fail;
                }
        }

        if (encaps_data) {
                memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
                nh_pos += encaps_len;
                h_pos += encaps_len;
        }
        memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
        nh_pos += hdrlen;
        h_pos += hdrlen;

        pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
        memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
        pkt_data->ifindex = sdata->dev->ifindex;
        pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
        pkt_data->do_not_encrypt = no_encrypt;

        skb->dev = local->mdev;
        sdata->stats.tx_packets++;
        sdata->stats.tx_bytes += skb->len;

        /* Update skb pointers to various headers since this modified frame
         * is going to go through Linux networking code that may potentially
         * need things like pointer to IP header. */
        skb_set_mac_header(skb, 0);
        skb_set_network_header(skb, nh_pos);
        skb_set_transport_header(skb, h_pos);

        dev->trans_start = jiffies;
        dev_queue_xmit(skb);

        return 0;

 fail:
        if (!ret)
                dev_kfree_skb(skb);

        return ret;
}


/*
 * This is the transmit routine for the 802.11 type interfaces
 * called by upper layers of the linux networking
 * stack when it has a frame to transmit
 */
static int
ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_tx_packet_data *pkt_data;
        struct ieee80211_hdr *hdr;
        u16 fc;

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        if (skb->len < 10) {
                dev_kfree_skb(skb);
                return 0;
        }

        if (skb_headroom(skb) < sdata->local->hw.extra_tx_headroom) {
                if (pskb_expand_head(skb,
                    sdata->local->hw.extra_tx_headroom, 0, GFP_ATOMIC)) {
                        dev_kfree_skb(skb);
                        return 0;
                }
        }

        hdr = (struct ieee80211_hdr *) skb->data;
        fc = le16_to_cpu(hdr->frame_control);

        pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
        memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
        pkt_data->ifindex = sdata->dev->ifindex;
        pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);

        skb->priority = 20; /* use hardcoded priority for mgmt TX queue */
        skb->dev = sdata->local->mdev;

        /*
         * We're using the protocol field of the the frame control header
         * to request TX callback for hostapd. BIT(1) is checked.
         */
        if ((fc & BIT(1)) == BIT(1)) {
                pkt_data->req_tx_status = 1;
                fc &= ~BIT(1);
                hdr->frame_control = cpu_to_le16(fc);
        }

        pkt_data->do_not_encrypt = !(fc & IEEE80211_FCTL_PROTECTED);

        sdata->stats.tx_packets++;
        sdata->stats.tx_bytes += skb->len;

        dev_queue_xmit(skb);

        return 0;
}


static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
                                     struct ieee80211_if_ap *bss,
                                     struct sk_buff *skb)
{
        u8 *pos, *tim;
        int aid0 = 0;
        int i, have_bits = 0, n1, n2;

        /* Generate bitmap for TIM only if there are any STAs in power save
         * mode. */
        spin_lock_bh(&local->sta_lock);
        if (atomic_read(&bss->num_sta_ps) > 0)
                /* in the hope that this is faster than
                 * checking byte-for-byte */
                have_bits = !bitmap_empty((unsigned long*)bss->tim,
                                          IEEE80211_MAX_AID+1);

        if (bss->dtim_count == 0)
                bss->dtim_count = bss->dtim_period - 1;
        else
                bss->dtim_count--;

        tim = pos = (u8 *) skb_put(skb, 6);
        *pos++ = WLAN_EID_TIM;
        *pos++ = 4;
        *pos++ = bss->dtim_count;
        *pos++ = bss->dtim_period;

        if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
                aid0 = 1;

        if (have_bits) {
                /* Find largest even number N1 so that bits numbered 1 through
                 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
                 * (N2 + 1) x 8 through 2007 are 0. */
                n1 = 0;
                for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
                        if (bss->tim[i]) {
                                n1 = i & 0xfe;
                                break;
                        }
                }
                n2 = n1;
                for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
                        if (bss->tim[i]) {
                                n2 = i;
                                break;
                        }
                }

                /* Bitmap control */
                *pos++ = n1 | aid0;
                /* Part Virt Bitmap */
                memcpy(pos, bss->tim + n1, n2 - n1 + 1);

                tim[1] = n2 - n1 + 4;
                skb_put(skb, n2 - n1);
        } else {
                *pos++ = aid0; /* Bitmap control */
                *pos++ = 0; /* Part Virt Bitmap */
        }
        spin_unlock_bh(&local->sta_lock);
}


struct sk_buff * ieee80211_beacon_get(struct ieee80211_hw *hw, int if_id,
                                      struct ieee80211_tx_control *control)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sk_buff *skb;
        struct net_device *bdev;
        struct ieee80211_sub_if_data *sdata = NULL;
        struct ieee80211_if_ap *ap = NULL;
        struct ieee80211_rate *rate;
        struct rate_control_extra extra;
        u8 *b_head, *b_tail;
        int bh_len, bt_len;

        bdev = dev_get_by_index(if_id);
        if (bdev) {
                sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
                ap = &sdata->u.ap;
                dev_put(bdev);
        }

        if (!ap || sdata->type != IEEE80211_IF_TYPE_AP ||
            !ap->beacon_head) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                if (net_ratelimit())
                        printk(KERN_DEBUG "no beacon data avail for idx=%d "
                               "(%s)\n", if_id, bdev ? bdev->name : "N/A");
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
                return NULL;
        }

        /* Assume we are generating the normal beacon locally */
        b_head = ap->beacon_head;
        b_tail = ap->beacon_tail;
        bh_len = ap->beacon_head_len;
        bt_len = ap->beacon_tail_len;

        skb = dev_alloc_skb(local->hw.extra_tx_headroom +
                bh_len + bt_len + 256 /* maximum TIM len */);
        if (!skb)
                return NULL;

        skb_reserve(skb, local->hw.extra_tx_headroom);
        memcpy(skb_put(skb, bh_len), b_head, bh_len);

        ieee80211_include_sequence(sdata, (struct ieee80211_hdr *)skb->data);

        ieee80211_beacon_add_tim(local, ap, skb);

        if (b_tail) {
                memcpy(skb_put(skb, bt_len), b_tail, bt_len);
        }

        if (control) {
                memset(&extra, 0, sizeof(extra));
                extra.mode = local->oper_hw_mode;

                rate = rate_control_get_rate(local, local->mdev, skb, &extra);
                if (!rate) {
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
                                       "found\n", local->mdev->name);
                        }
                        dev_kfree_skb(skb);
                        return NULL;
                }

                control->tx_rate = (local->short_preamble &&
                                    (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
                        rate->val2 : rate->val;
                control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
                control->power_level = local->hw.conf.power_level;
                control->flags |= IEEE80211_TXCTL_NO_ACK;
                control->retry_limit = 1;
                control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
        }

        ap->num_beacons++;
        return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
                              size_t frame_len,
                              const struct ieee80211_tx_control *frame_txctl)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_rate *rate;
        int short_preamble = local->short_preamble;
        int erp;
        u16 dur;

        rate = frame_txctl->rts_rate;
        erp = !!(rate->flags & IEEE80211_RATE_ERP);

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

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


__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
                                    size_t frame_len,
                                    const struct ieee80211_tx_control *frame_txctl)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_rate *rate;
        int short_preamble = local->short_preamble;
        int erp;
        u16 dur;

        rate = frame_txctl->rts_rate;
        erp = !!(rate->flags & IEEE80211_RATE_ERP);

        /* Data frame duration */
        dur = ieee80211_frame_duration(local, frame_len, rate->rate,
                                       erp, short_preamble);
        if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
                /* ACK duration */
                dur += ieee80211_frame_duration(local, 10, rate->rate,
                                                erp, short_preamble);
        }

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

void ieee80211_rts_get(struct ieee80211_hw *hw,
                       const void *frame, size_t frame_len,
                       const struct ieee80211_tx_control *frame_txctl,
                       struct ieee80211_rts *rts)
{
        const struct ieee80211_hdr *hdr = frame;
        u16 fctl;

        fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
        rts->frame_control = cpu_to_le16(fctl);
        rts->duration = ieee80211_rts_duration(hw, frame_len, frame_txctl);
        memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
        memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
                             const void *frame, size_t frame_len,
                             const struct ieee80211_tx_control *frame_txctl,
                             struct ieee80211_cts *cts)
{
        const struct ieee80211_hdr *hdr = frame;
        u16 fctl;

        fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
        cts->frame_control = cpu_to_le16(fctl);
        cts->duration = ieee80211_ctstoself_duration(hw, frame_len, frame_txctl);
        memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
ieee80211_get_buffered_bc(struct ieee80211_hw *hw, int if_id,
                          struct ieee80211_tx_control *control)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sk_buff *skb;
        struct sta_info *sta;
        ieee80211_tx_handler *handler;
        struct ieee80211_txrx_data tx;
        ieee80211_txrx_result res = TXRX_DROP;
        struct net_device *bdev;
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_if_ap *bss = NULL;

        bdev = dev_get_by_index(if_id);
        if (bdev) {
                sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
                bss = &sdata->u.ap;
                dev_put(bdev);
        }
        if (!bss || sdata->type != IEEE80211_IF_TYPE_AP || !bss->beacon_head)
                return NULL;

        if (bss->dtim_count != 0)
                return NULL; /* send buffered bc/mc only after DTIM beacon */
        memset(control, 0, sizeof(*control));
        while (1) {
                skb = skb_dequeue(&bss->ps_bc_buf);
                if (!skb)
                        return NULL;
                local->total_ps_buffered--;

                if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
                        struct ieee80211_hdr *hdr =
                                (struct ieee80211_hdr *) skb->data;
                        /* more buffered multicast/broadcast frames ==> set
                         * MoreData flag in IEEE 802.11 header to inform PS
                         * STAs */
                        hdr->frame_control |=
                                cpu_to_le16(IEEE80211_FCTL_MOREDATA);
                }

                if (ieee80211_tx_prepare(&tx, skb, local->mdev, control) == 0)
                        break;
                dev_kfree_skb_any(skb);
        }
        sta = tx.sta;
        tx.u.tx.ps_buffered = 1;

        for (handler = local->tx_handlers; *handler != NULL; handler++) {
                res = (*handler)(&tx);
                if (res == TXRX_DROP || res == TXRX_QUEUED)
                        break;
        }
        dev_put(tx.dev);
        skb = tx.skb; /* handlers are allowed to change skb */

        if (res == TXRX_DROP) {
                I802_DEBUG_INC(local->tx_handlers_drop);
                dev_kfree_skb(skb);
                skb = NULL;
        } else if (res == TXRX_QUEUED) {
                I802_DEBUG_INC(local->tx_handlers_queued);
                skb = NULL;
        }

        if (sta)
                sta_info_put(sta);

        return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);

static int __ieee80211_if_config(struct net_device *dev,
                                 struct sk_buff *beacon,
                                 struct ieee80211_tx_control *control)
{
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_if_conf conf;
        static u8 scan_bssid[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

        if (!local->ops->config_interface || !netif_running(dev))
                return 0;

        memset(&conf, 0, sizeof(conf));
        conf.type = sdata->type;
        if (sdata->type == IEEE80211_IF_TYPE_STA ||
            sdata->type == IEEE80211_IF_TYPE_IBSS) {
                if (local->sta_scanning &&
                    local->scan_dev == dev)
                        conf.bssid = scan_bssid;
                else
                        conf.bssid = sdata->u.sta.bssid;
                conf.ssid = sdata->u.sta.ssid;
                conf.ssid_len = sdata->u.sta.ssid_len;
                conf.generic_elem = sdata->u.sta.extra_ie;
                conf.generic_elem_len = sdata->u.sta.extra_ie_len;
        } else if (sdata->type == IEEE80211_IF_TYPE_AP) {
                conf.ssid = sdata->u.ap.ssid;
                conf.ssid_len = sdata->u.ap.ssid_len;
                conf.generic_elem = sdata->u.ap.generic_elem;
                conf.generic_elem_len = sdata->u.ap.generic_elem_len;
                conf.beacon = beacon;
                conf.beacon_control = control;
        }
        return local->ops->config_interface(local_to_hw(local),
                                           dev->ifindex, &conf);
}

int ieee80211_if_config(struct net_device *dev)
{
        return __ieee80211_if_config(dev, NULL, NULL);
}

int ieee80211_if_config_beacon(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_tx_control control;
        struct sk_buff *skb;

        if (!(local->hw.flags & IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE))
                return 0;
        skb = ieee80211_beacon_get(local_to_hw(local), dev->ifindex, &control);
        if (!skb)
                return -ENOMEM;
        return __ieee80211_if_config(dev, skb, &control);
}

int ieee80211_hw_config(struct ieee80211_local *local)
{
        struct ieee80211_hw_mode *mode;
        struct ieee80211_channel *chan;
        int ret = 0;

        if (local->sta_scanning) {
                chan = local->scan_channel;
                mode = local->scan_hw_mode;
        } else {
                chan = local->oper_channel;
                mode = local->oper_hw_mode;
        }

        local->hw.conf.channel = chan->chan;
        local->hw.conf.channel_val = chan->val;
        local->hw.conf.power_level = chan->power_level;
        local->hw.conf.freq = chan->freq;
        local->hw.conf.phymode = mode->mode;
        local->hw.conf.antenna_max = chan->antenna_max;
        local->hw.conf.chan = chan;
        local->hw.conf.mode = mode;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "HW CONFIG: channel=%d freq=%d "
               "phymode=%d\n", local->hw.conf.channel, local->hw.conf.freq,
               local->hw.conf.phymode);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */

        if (local->ops->config)
                ret = local->ops->config(local_to_hw(local), &local->hw.conf);

        return ret;
}


static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
{
        /* FIX: what would be proper limits for MTU?
         * This interface uses 802.3 frames. */
        if (new_mtu < 256 || new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6) {
                printk(KERN_WARNING "%s: invalid MTU %d\n",
                       dev->name, new_mtu);
                return -EINVAL;
        }

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
        dev->mtu = new_mtu;
        return 0;
}


static int ieee80211_change_mtu_apdev(struct net_device *dev, int new_mtu)
{
        /* FIX: what would be proper limits for MTU?
         * This interface uses 802.11 frames. */
        if (new_mtu < 256 || new_mtu > IEEE80211_MAX_DATA_LEN) {
                printk(KERN_WARNING "%s: invalid MTU %d\n",
                       dev->name, new_mtu);
                return -EINVAL;
        }

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
        printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
        dev->mtu = new_mtu;
        return 0;
}

enum netif_tx_lock_class {
        TX_LOCK_NORMAL,
        TX_LOCK_MASTER,
};

static inline void netif_tx_lock_nested(struct net_device *dev, int subclass)
{
        spin_lock_nested(&dev->_xmit_lock, subclass);
        dev->xmit_lock_owner = smp_processor_id();
}

static void ieee80211_set_multicast_list(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        unsigned short flags;

        netif_tx_lock_nested(local->mdev, TX_LOCK_MASTER);
        if (((dev->flags & IFF_ALLMULTI) != 0) ^ (sdata->allmulti != 0)) {
                if (sdata->allmulti) {
                        sdata->allmulti = 0;
                        local->iff_allmultis--;
                } else {
                        sdata->allmulti = 1;
                        local->iff_allmultis++;
                }
        }
        if (((dev->flags & IFF_PROMISC) != 0) ^ (sdata->promisc != 0)) {
                if (sdata->promisc) {
                        sdata->promisc = 0;
                        local->iff_promiscs--;
                } else {
                        sdata->promisc = 1;
                        local->iff_promiscs++;
                }
        }
        if (dev->mc_count != sdata->mc_count) {
                local->mc_count = local->mc_count - sdata->mc_count +
                                  dev->mc_count;
                sdata->mc_count = dev->mc_count;
        }
        if (local->ops->set_multicast_list) {
                flags = local->mdev->flags;
                if (local->iff_allmultis)
                        flags |= IFF_ALLMULTI;
                if (local->iff_promiscs)
                        flags |= IFF_PROMISC;
                read_lock(&local->sub_if_lock);
                local->ops->set_multicast_list(local_to_hw(local), flags,
                                              local->mc_count);
                read_unlock(&local->sub_if_lock);
        }
        netif_tx_unlock(local->mdev);
}

struct dev_mc_list *ieee80211_get_mc_list_item(struct ieee80211_hw *hw,
                                               struct dev_mc_list *prev,
                                               void **ptr)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_sub_if_data *sdata = *ptr;
        struct dev_mc_list *mc;

        if (!prev) {
                WARN_ON(sdata);
                sdata = NULL;
        }
        if (!prev || !prev->next) {
                if (sdata)
                        sdata = list_entry(sdata->list.next,
                                           struct ieee80211_sub_if_data, list);
                else
                        sdata = list_entry(local->sub_if_list.next,
                                           struct ieee80211_sub_if_data, list);
                if (&sdata->list != &local->sub_if_list)
                        mc = sdata->dev->mc_list;
                else
                        mc = NULL;
        } else
                mc = prev->next;

        *ptr = sdata;
        return mc;
}
EXPORT_SYMBOL(ieee80211_get_mc_list_item);

static struct net_device_stats *ieee80211_get_stats(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata;
        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        return &(sdata->stats);
}

static void ieee80211_if_shutdown(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        ASSERT_RTNL();
        switch (sdata->type) {
        case IEEE80211_IF_TYPE_STA:
        case IEEE80211_IF_TYPE_IBSS:
                sdata->u.sta.state = IEEE80211_DISABLED;
                del_timer_sync(&sdata->u.sta.timer);
                skb_queue_purge(&sdata->u.sta.skb_queue);
                if (!local->ops->hw_scan &&
                    local->scan_dev == sdata->dev) {
                        local->sta_scanning = 0;
                        cancel_delayed_work(&local->scan_work);
                }
                flush_workqueue(local->hw.workqueue);
                break;
        }
}

static inline int identical_mac_addr_allowed(int type1, int type2)
{
        return (type1 == IEEE80211_IF_TYPE_MNTR ||
                type2 == IEEE80211_IF_TYPE_MNTR ||
                (type1 == IEEE80211_IF_TYPE_AP &&
                 type2 == IEEE80211_IF_TYPE_WDS) ||
                (type1 == IEEE80211_IF_TYPE_WDS &&
                 (type2 == IEEE80211_IF_TYPE_WDS ||
                  type2 == IEEE80211_IF_TYPE_AP)) ||
                (type1 == IEEE80211_IF_TYPE_AP &&
                 type2 == IEEE80211_IF_TYPE_VLAN) ||
                (type1 == IEEE80211_IF_TYPE_VLAN &&
                 (type2 == IEEE80211_IF_TYPE_AP ||
                  type2 == IEEE80211_IF_TYPE_VLAN)));
}

static int ieee80211_master_open(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;
        int res = -EOPNOTSUPP;

        read_lock(&local->sub_if_lock);
        list_for_each_entry(sdata, &local->sub_if_list, list) {
                if (sdata->dev != dev && netif_running(sdata->dev)) {
                        res = 0;
                        break;
                }
        }
        read_unlock(&local->sub_if_lock);
        return res;
}

static int ieee80211_master_stop(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;

        read_lock(&local->sub_if_lock);
        list_for_each_entry(sdata, &local->sub_if_list, list)
                if (sdata->dev != dev && netif_running(sdata->dev))
                        dev_close(sdata->dev);
        read_unlock(&local->sub_if_lock);

        return 0;
}

static int ieee80211_mgmt_open(struct net_device *dev)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

        if (!netif_running(local->mdev))
                return -EOPNOTSUPP;
        return 0;
}

static int ieee80211_mgmt_stop(struct net_device *dev)
{
        return 0;
}

/* Check if running monitor interfaces should go to a "soft monitor" mode
 * and switch them if necessary. */
static inline void ieee80211_start_soft_monitor(struct ieee80211_local *local)
{
        struct ieee80211_if_init_conf conf;

        if (local->open_count && local->open_count == local->monitors &&
            !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER) &&
            local->ops->remove_interface) {
                conf.if_id = -1;
                conf.type = IEEE80211_IF_TYPE_MNTR;
                conf.mac_addr = NULL;
                local->ops->remove_interface(local_to_hw(local), &conf);
        }
}

/* Check if running monitor interfaces should go to a "hard monitor" mode
 * and switch them if necessary. */
static void ieee80211_start_hard_monitor(struct ieee80211_local *local)
{
        struct ieee80211_if_init_conf conf;

        if (local->open_count && local->open_count == local->monitors &&
            !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER) &&
            local->ops->add_interface) {
                conf.if_id = -1;
                conf.type = IEEE80211_IF_TYPE_MNTR;
                conf.mac_addr = NULL;
                local->ops->add_interface(local_to_hw(local), &conf);
        }
}

static int ieee80211_open(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata, *nsdata;
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_if_init_conf conf;
        int res;

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        read_lock(&local->sub_if_lock);
        list_for_each_entry(nsdata, &local->sub_if_list, list) {
                struct net_device *ndev = nsdata->dev;

                if (ndev != dev && ndev != local->mdev && netif_running(ndev) &&
                    compare_ether_addr(dev->dev_addr, ndev->dev_addr) == 0 &&
                    !identical_mac_addr_allowed(sdata->type, nsdata->type)) {
                        read_unlock(&local->sub_if_lock);
                        return -ENOTUNIQ;
                }
        }
        read_unlock(&local->sub_if_lock);

        if (sdata->type == IEEE80211_IF_TYPE_WDS &&
            is_zero_ether_addr(sdata->u.wds.remote_addr))
                return -ENOLINK;

        if (sdata->type == IEEE80211_IF_TYPE_MNTR && local->open_count &&
            !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {
                /* run the interface in a "soft monitor" mode */
                local->monitors++;
                local->open_count++;
                local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
                return 0;
        }
        ieee80211_start_soft_monitor(local);

        if (local->ops->add_interface) {
                conf.if_id = dev->ifindex;
                conf.type = sdata->type;
                conf.mac_addr = dev->dev_addr;
                res = local->ops->add_interface(local_to_hw(local), &conf);
                if (res) {
                        if (sdata->type == IEEE80211_IF_TYPE_MNTR)
                                ieee80211_start_hard_monitor(local);
                        return res;
                }
        } else {
                if (sdata->type != IEEE80211_IF_TYPE_STA)
                        return -EOPNOTSUPP;
                if (local->open_count > 0)
                        return -ENOBUFS;
        }

        if (local->open_count == 0) {
                res = 0;
                tasklet_enable(&local->tx_pending_tasklet);
                tasklet_enable(&local->tasklet);
                if (local->ops->open)
                        res = local->ops->open(local_to_hw(local));
                if (res == 0) {
                        res = dev_open(local->mdev);
                        if (res) {
                                if (local->ops->stop)
                                        local->ops->stop(local_to_hw(local));
                        } else {
                                res = ieee80211_hw_config(local);
                                if (res && local->ops->stop)
                                        local->ops->stop(local_to_hw(local));
                                else if (!res && local->apdev)
                                        dev_open(local->apdev);
                        }
                }
                if (res) {
                        if (local->ops->remove_interface)
                                local->ops->remove_interface(local_to_hw(local),
                                                            &conf);
                        return res;
                }
        }
        local->open_count++;

        if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
                local->monitors++;
                local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
        } else
                ieee80211_if_config(dev);

        if (sdata->type == IEEE80211_IF_TYPE_STA &&
            !local->user_space_mlme)
                netif_carrier_off(dev);

        netif_start_queue(dev);
        return 0;
}


static int ieee80211_stop(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        if (sdata->type == IEEE80211_IF_TYPE_MNTR &&
            local->open_count > 1 &&
            !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {
                /* remove "soft monitor" interface */
                local->open_count--;
                local->monitors--;
                if (!local->monitors)
                        local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
                return 0;
        }

        netif_stop_queue(dev);
        ieee80211_if_shutdown(dev);

        if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
                local->monitors--;
                if (!local->monitors)
                        local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
        }

        local->open_count--;
        if (local->open_count == 0) {
                if (netif_running(local->mdev))
                        dev_close(local->mdev);
                if (local->apdev)
                        dev_close(local->apdev);
                if (local->ops->stop)
                        local->ops->stop(local_to_hw(local));
                tasklet_disable(&local->tx_pending_tasklet);
                tasklet_disable(&local->tasklet);
        }
        if (local->ops->remove_interface) {
                struct ieee80211_if_init_conf conf;

                conf.if_id = dev->ifindex;
                conf.type = sdata->type;
                conf.mac_addr = dev->dev_addr;
                local->ops->remove_interface(local_to_hw(local), &conf);
        }

        ieee80211_start_hard_monitor(local);

        return 0;
}


static int header_parse_80211(struct sk_buff *skb, unsigned char *haddr)
{
        memcpy(haddr, skb_mac_header(skb) + 10, ETH_ALEN); /* addr2 */
        return ETH_ALEN;
}

static inline int ieee80211_bssid_match(const u8 *raddr, const u8 *addr)
{
        return compare_ether_addr(raddr, addr) == 0 ||
               is_broadcast_ether_addr(raddr);
}


static ieee80211_txrx_result
ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
{
        struct net_device *dev = rx->dev;
        struct ieee80211_local *local = rx->local;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
        u16 fc, hdrlen, ethertype;
        u8 *payload;
        u8 dst[ETH_ALEN];
        u8 src[ETH_ALEN];
        struct sk_buff *skb = rx->skb, *skb2;
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        fc = rx->fc;
        if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
                return TXRX_CONTINUE;

        if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
                return TXRX_DROP;

        hdrlen = ieee80211_get_hdrlen(fc);

        /* convert IEEE 802.11 header + possible LLC headers into Ethernet
         * header
         * IEEE 802.11 address fields:
         * ToDS FromDS Addr1 Addr2 Addr3 Addr4
         *   0     0   DA    SA    BSSID n/a
         *   0     1   DA    BSSID SA    n/a
         *   1     0   BSSID SA    DA    n/a
         *   1     1   RA    TA    DA    SA
         */

        switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
        case IEEE80211_FCTL_TODS:
                /* BSSID SA DA */
                memcpy(dst, hdr->addr3, ETH_ALEN);
                memcpy(src, hdr->addr2, ETH_ALEN);

                if (unlikely(sdata->type != IEEE80211_IF_TYPE_AP &&
                             sdata->type != IEEE80211_IF_TYPE_VLAN)) {
                        printk(KERN_DEBUG "%s: dropped ToDS frame (BSSID="
                               MAC_FMT " SA=" MAC_FMT " DA=" MAC_FMT ")\n",
                               dev->name, MAC_ARG(hdr->addr1),
                               MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr3));
                        return TXRX_DROP;
                }
                break;
        case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
                /* RA TA DA SA */
                memcpy(dst, hdr->addr3, ETH_ALEN);
                memcpy(src, hdr->addr4, ETH_ALEN);

                if (unlikely(sdata->type != IEEE80211_IF_TYPE_WDS)) {
                        printk(KERN_DEBUG "%s: dropped FromDS&ToDS frame (RA="
                               MAC_FMT " TA=" MAC_FMT " DA=" MAC_FMT " SA="
                               MAC_FMT ")\n",
                               rx->dev->name, MAC_ARG(hdr->addr1),
                               MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr3),
                               MAC_ARG(hdr->addr4));
                        return TXRX_DROP;
                }
                break;
        case IEEE80211_FCTL_FROMDS:
                /* DA BSSID SA */
                memcpy(dst, hdr->addr1, ETH_ALEN);
                memcpy(src, hdr->addr3, ETH_ALEN);

                if (sdata->type != IEEE80211_IF_TYPE_STA) {
                        return TXRX_DROP;
                }
                break;
        case 0:
                /* DA SA BSSID */
                memcpy(dst, hdr->addr1, ETH_ALEN);
                memcpy(src, hdr->addr2, ETH_ALEN);

                if (sdata->type != IEEE80211_IF_TYPE_IBSS) {
                        if (net_ratelimit()) {
                                printk(KERN_DEBUG "%s: dropped IBSS frame (DA="
                                       MAC_FMT " SA=" MAC_FMT " BSSID=" MAC_FMT
                                       ")\n",
                                       dev->name, MAC_ARG(hdr->addr1),
                                       MAC_ARG(hdr->addr2),
                                       MAC_ARG(hdr->addr3));
                        }
                        return TXRX_DROP;
                }
                break;
        }

        payload = skb->data + hdrlen;

        if (unlikely(skb->len - hdrlen < 8)) {
                if (net_ratelimit()) {
                        printk(KERN_DEBUG "%s: RX too short data frame "
                               "payload\n", dev->name);
                }
                return TXRX_DROP;
        }

        ethertype = (payload[6] << 8) | payload[7];

        if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
                    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
                   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
                /* remove RFC1042 or Bridge-Tunnel encapsulation and
                 * replace EtherType */
                skb_pull(skb, hdrlen + 6);
                memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
                memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
        } else {
                struct ethhdr *ehdr;
                __be16 len;
                skb_pull(skb, hdrlen);
                len = htons(skb->len);
                ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
                memcpy(ehdr->h_dest, dst, ETH_ALEN);
                memcpy(ehdr->h_source, src, ETH_ALEN);
                ehdr->h_proto = len;
        }
        skb->dev = dev;

        skb2 = NULL;

        sdata->stats.rx_packets++;
        sdata->stats.rx_bytes += skb->len;

        if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
            || sdata->type == IEEE80211_IF_TYPE_VLAN) && rx->u.rx.ra_match) {
                if (is_multicast_ether_addr(skb->data)) {
                        /* send multicast frames both to higher layers in
                         * local net stack and back to the wireless media */
                        skb2 = skb_copy(skb, GFP_ATOMIC);
                        if (!skb2)
                                printk(KERN_DEBUG "%s: failed to clone "
                                       "multicast frame\n", dev->name);
                } else {
                        struct sta_info *dsta;
                        dsta = sta_info_get(local, skb->data);
                        if (dsta && !dsta->dev) {
                                printk(KERN_DEBUG "Station with null dev "
                                       "structure!\n");
                        } else if (dsta && dsta->dev == dev) {
                                /* Destination station is associated to this
                                 * AP, so send the frame directly to it and
                                 * do not pass the frame to local net stack.
                                 */
                                skb2 = skb;
                                skb = NULL;
                        }
                        if (dsta)
                                sta_info_put(dsta);
                }
        }

        if (skb) {
                /* deliver to local stack */
                skb->protocol = eth_type_trans(skb, dev);
                memset(skb->cb, 0, sizeof(skb->cb));
                netif_rx(skb);
        }

        if (skb2) {
                /* send to wireless media */
                skb2->protocol = __constant_htons(ETH_P_802_3);
                skb_set_network_header(skb2, 0);
                skb_set_mac_header(skb2, 0);
                dev_queue_xmit(skb2);
        }

        return TXRX_QUEUED;
}


static struct ieee80211_rate *
ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate)
{
        struct ieee80211_hw_mode *mode;
        int r;

        list_for_each_entry(mode, &local->modes_list, list) {
                if (mode->mode != phymode)
                        continue;
                for (r = 0; r < mode->num_rates; r++) {
                        struct ieee80211_rate *rate = &mode->rates[r];
                        if (rate->val == hw_rate ||
                            (rate->flags & IEEE80211_RATE_PREAMBLE2 &&
                             rate->val2 == hw_rate))
                                return rate;
                }
        }

        return NULL;
}

static void
ieee80211_fill_frame_info(struct ieee80211_local *local,
                          struct ieee80211_frame_info *fi,
                          struct ieee80211_rx_status *status)
{
        if (status) {
                struct timespec ts;
                struct ieee80211_rate *rate;

                jiffies_to_timespec(jiffies, &ts);
                fi->hosttime = cpu_to_be64((u64) ts.tv_sec * 1000000 +
                                           ts.tv_nsec / 1000);
                fi->mactime = cpu_to_be64(status->mactime);
                switch (status->phymode) {
                case MODE_IEEE80211A:
                        fi->phytype = htonl(ieee80211_phytype_ofdm_dot11_a);
                        break;
                case MODE_IEEE80211B:
                        fi->phytype = htonl(ieee80211_phytype_dsss_dot11_b);
                        break;
                case MODE_IEEE80211G:
                        fi->phytype = htonl(ieee80211_phytype_pbcc_dot11_g);
                        break;
                case MODE_ATHEROS_TURBO:
                        fi->phytype =
                                htonl(ieee80211_phytype_dsss_dot11_turbo);
                        break;
                default:
                        fi->phytype = htonl(0xAAAAAAAA);
                        break;
                }
                fi->channel = htonl(status->channel);
                rate = ieee80211_get_rate(local, status->phymode,
                                          status->rate);
                if (rate) {
                        fi->datarate = htonl(rate->rate);
                        if (rate->flags & IEEE80211_RATE_PREAMBLE2) {
                                if (status->rate == rate->val)
                                        fi->preamble = htonl(2); /* long */
                                else if (status->rate == rate->val2)
                                        fi->preamble = htonl(1); /* short */
                        } else
                                fi->preamble = htonl(0);
                } else {
                        fi->datarate = htonl(0);
                        fi->preamble = htonl(0);
                }

                fi->antenna = htonl(status->antenna);
                fi->priority = htonl(0xffffffff); /* no clue */
                fi->ssi_type = htonl(ieee80211_ssi_raw);
                fi->ssi_signal = htonl(status->ssi);
                fi->ssi_noise = 0x00000000;
                fi->encoding = 0;
        } else {
                /* clear everything because we really don't know.
                 * the msg_type field isn't present on monitor frames
                 * so we don't know whether it will be present or not,
                 * but it's ok to not clear it since it'll be assigned
                 * anyway */
                memset(fi, 0, sizeof(*fi) - sizeof(fi->msg_type));

                fi->ssi_type = htonl(ieee80211_ssi_none);
        }
        fi->version = htonl(IEEE80211_FI_VERSION);
        fi->length = cpu_to_be32(sizeof(*fi) - sizeof(fi->msg_type));
}

/* this routine is actually not just for this, but also
 * for pushing fake 'management' frames into userspace.
 * it shall be replaced by a netlink-based system. */
void
ieee80211_rx_mgmt(struct ieee80211_local *local, struct sk_buff *skb,
                  struct ieee80211_rx_status *status, u32 msg_type)
{
        struct ieee80211_frame_info *fi;
        const size_t hlen = sizeof(struct ieee80211_frame_info);
        struct ieee80211_sub_if_data *sdata;

        skb->dev = local->apdev;

        sdata = IEEE80211_DEV_TO_SUB_IF(local->apdev);

        if (skb_headroom(skb) < hlen) {
                I802_DEBUG_INC(local->rx_expand_skb_head);
                if (pskb_expand_head(skb, hlen, 0, GFP_ATOMIC)) {
                        dev_kfree_skb(skb);
                        return;
                }
        }

        fi = (struct ieee80211_frame_info *) skb_push(skb, hlen);

        ieee80211_fill_frame_info(local, fi, status);
        fi->msg_type = htonl(msg_type);

        sdata->stats.rx_packets++;
        sdata->stats.rx_bytes += skb->len;

        skb_set_mac_header(skb, 0);
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->pkt_type = PACKET_OTHERHOST;
        skb->protocol = htons(ETH_P_802_2);
        memset(skb->cb, 0, sizeof(skb->cb));
        netif_rx(skb);
}

static void
ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
                     struct ieee80211_rx_status *status)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_rate *rate;
        struct ieee80211_rtap_hdr {
                struct ieee80211_radiotap_header hdr;
                u8 flags;
                u8 rate;
                __le16 chan_freq;
                __le16 chan_flags;
                u8 antsignal;
        } __attribute__ ((packed)) *rthdr;

        skb->dev = dev;

        sdata = IEEE80211_DEV_TO_SUB_IF(dev);

        if (status->flag & RX_FLAG_RADIOTAP)
                goto out;

        if (skb_headroom(skb) < sizeof(*rthdr)) {
                I802_DEBUG_INC(local->rx_expand_skb_head);
                if (pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) {
                        dev_kfree_skb(skb);
                        return;
                }
        }

        rthdr = (struct ieee80211_rtap_hdr *) skb_push(skb, sizeof(*rthdr));
        memset(rthdr, 0, sizeof(*rthdr));
        rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
        rthdr->hdr.it_present =
                cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
                            (1 << IEEE80211_RADIOTAP_RATE) |
                            (1 << IEEE80211_RADIOTAP_CHANNEL) |
                            (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL));
        rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
                       IEEE80211_RADIOTAP_F_FCS : 0;
        rate = ieee80211_get_rate(local, status->phymode, status->rate);
        if (rate)
                rthdr->rate = rate->rate / 5;
        rthdr->chan_freq = cpu_to_le16(status->freq);
        rthdr->chan_flags =
                status->phymode == MODE_IEEE80211A ?
                cpu_to_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ) :
                cpu_to_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ);
        rthdr->antsignal = status->ssi;

 out:
        sdata->stats.rx_packets++;
        sdata->stats.rx_bytes += skb->len;

        skb_set_mac_header(skb, 0);
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->pkt_type = PACKET_OTHERHOST;
        skb->protocol = htons(ETH_P_802_2);
        memset(skb->cb, 0, sizeof(skb->cb));
        netif_rx(skb);
}

int ieee80211_radar_status(struct ieee80211_hw *hw, int channel,
                           int radar, int radar_type)
{
        struct sk_buff *skb;
        struct ieee80211_radar_info *msg;
        struct ieee80211_local *local = hw_to_local(hw);

        if (!local->apdev)
                return 0;

        skb = dev_alloc_skb(sizeof(struct ieee80211_frame_info) +
                            sizeof(struct ieee80211_radar_info));

        if (!skb)
                return -ENOMEM;
        skb_reserve(skb, sizeof(struct ieee80211_frame_info));

        msg = (struct ieee80211_radar_info *)
                skb_put(skb, sizeof(struct ieee80211_radar_info));
        msg->channel = channel;
        msg->radar = radar;
        msg->radar_type = radar_type;

        ieee80211_rx_mgmt(local, skb, NULL, ieee80211_msg_radar);
        return 0;
}
EXPORT_SYMBOL(ieee80211_radar_status);

int ieee80211_set_aid_for_sta(struct ieee80211_hw *hw, u8 *peer_address,
                              u16 aid)
{
        struct sk_buff *skb;
        struct ieee80211_msg_set_aid_for_sta *msg;
        struct ieee80211_local *local = hw_to_local(hw);

        /* unlikely because if this event only happens for APs,
         * which require an open ap device. */
        if (unlikely(!local->apdev))
                return 0;

        skb = dev_alloc_skb(sizeof(struct ieee80211_frame_info) +
                            sizeof(struct ieee80211_msg_set_aid_for_sta));

        if (!skb)
                return -ENOMEM;
        skb_reserve(skb, sizeof(struct ieee80211_frame_info));

        msg = (struct ieee80211_msg_set_aid_for_sta *)
                skb_put(skb, sizeof(struct ieee80211_msg_set_aid_for_sta));
        memcpy(msg->sta_address, peer_address, ETH_ALEN);
        msg->aid = aid;

        ieee80211_rx_mgmt(local, skb, NULL, ieee80211_msg_set_aid_for_sta);
        return 0;
}
EXPORT_SYMBOL(ieee80211_set_aid_for_sta);

static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
{
        struct ieee80211_sub_if_data *sdata;
        sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

        if (sdata->bss)
                atomic_inc(&sdata->bss->num_sta_ps);
        sta->flags |= WLAN_STA_PS;
        sta->pspoll = 0;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d enters power "
               "save mode\n", dev->name, MAC_ARG(sta->addr), sta->aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}


static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct sk_buff *skb;
        int sent = 0;
        struct ieee80211_sub_if_data *sdata;
        struct ieee80211_tx_packet_data *pkt_data;

        sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
        if (sdata->bss)
                atomic_dec(&sdata->bss->num_sta_ps);
        sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
        sta->pspoll = 0;
        if (!skb_queue_empty(&sta->ps_tx_buf)) {
                if (local->ops->set_tim)
                        local->ops->set_tim(local_to_hw(local), sta->aid, 0);
                if (sdata->bss)
                        bss_tim_clear(local, sdata->bss, sta->aid);
        }
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d exits power "
               "save mode\n", dev->name, MAC_ARG(sta->addr), sta->aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
        /* Send all buffered frames to the station */
        while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
                pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
                sent++;
                pkt_data->requeue = 1;
                dev_queue_xmit(skb);
        }
        while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
                pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
                local->total_ps_buffered--;
                sent++;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
                printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d send PS frame "
                       "since STA not sleeping anymore\n", dev->name,
                       MAC_ARG(sta->addr), sta->aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
                pkt_data->requeue = 1;
                dev_queue_xmit(skb);
        }

        return sent;
}


static ieee80211_txrx_result
ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
{
        struct sk_buff *skb;
        int no_pending_pkts;

        if (likely(!rx->sta ||
                   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
                   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
                   !rx->u.rx.ra_match))
                return TXRX_CONTINUE;

        skb = skb_dequeue(&rx->sta->tx_filtered);
        if (!skb) {
                skb = skb_dequeue(&rx->sta->ps_tx_buf);
                if (skb)
                        rx->local->total_ps_buffered--;
        }
        no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
                skb_queue_empty(&rx->sta->ps_tx_buf);

        if (skb) {
                struct ieee80211_hdr *hdr =
                        (struct ieee80211_hdr *) skb->data;

                /* tell TX path to send one frame even though the STA may
                 * still remain is PS mode after this frame exchange */
                rx->sta->pspoll = 1;

#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
                printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS Poll (entries "
                       "after %d)\n",
                       MAC_ARG(rx->sta->addr), rx->sta->aid,
                       skb_queue_len(&rx->sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */

                /* Use MoreData flag to indicate whether there are more
                 * buffered frames for this STA */
                if (no_pending_pkts) {
                        hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
                        rx->sta->flags &= ~WLAN_STA_TIM;
                } else
                        hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);

                dev_queue_xmit(skb);

                if (no_pending_pkts) {
                        if (rx->local->ops->set_tim)
                                rx->local->ops->set_tim(local_to_hw(rx->local),
                                                       rx->sta->aid, 0);
                        if (rx->sdata->bss)
                                bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
                }
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
        } else if (!rx->u.rx.sent_ps_buffered) {
                printk(KERN_DEBUG "%s: STA " MAC_FMT " sent PS Poll even "
                       "though there is no buffered frames for it\n",
                       rx->dev->name, MAC_ARG(rx->sta->addr));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */

        }

        /* Free PS Poll skb here instead of returning TXRX_DROP that would
         * count as an dropped frame. */
        dev_kfree_skb(rx->skb);

        return TXRX_QUEUED;
}


static inline struct ieee80211_fragment_entry *
ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
                         unsigned int frag, unsigned int seq, int rx_queue,
                         struct sk_buff **skb)
{
        struct ieee80211_fragment_entry *entry;
        int idx;

        idx = sdata->fragment_next;
        entry = &sdata->fragments[sdata->fragment_next++];
        if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
                sdata->fragment_next = 0;

        if (!skb_queue_empty(&entry->skb_list)) {
#ifdef CONFIG_MAC80211_DEBUG
                struct ieee80211_hdr *hdr =
                        (struct ieee80211_hdr *) entry->skb_list.next->data;
                printk(KERN_DEBUG "%s: RX reassembly removed oldest "
                       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
                       "addr1=" MAC_FMT " addr2=" MAC_FMT "\n",
                       sdata->dev->name, idx,
                       jiffies - entry->first_frag_time, entry->seq,
                       entry->last_frag, MAC_ARG(hdr->addr1),
                       MAC_ARG(hdr->addr2));
#endif /* CONFIG_MAC80211_DEBUG */
                __skb_queue_purge(&entry->skb_list);
        }

        __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
        *skb = NULL;
        entry->first_frag_time = jiffies;
        entry->seq = seq;
        entry->rx_queue = rx_queue;
        entry->last_frag = frag;
        entry->ccmp = 0;
        entry->extra_len = 0;

        return entry;
}


static inline struct ieee80211_fragment_entry *
ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
                          u16 fc, unsigned int frag, unsigned int seq,
                          int rx_queue, struct ieee80211_hdr *hdr)
{
        struct ieee80211_fragment_entry *entry;
        int i, idx;

        idx = sdata->fragment_next;
        for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
                struct ieee80211_hdr *f_hdr;
                u16 f_fc;

                idx--;
                if (idx < 0)
                        idx = IEEE80211_FRAGMENT_MAX - 1;

                entry = &sdata->fragments[idx];
                if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
                    entry->rx_queue != rx_queue ||
                    entry->last_frag + 1 != frag)
                        continue;

                f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
                f_fc = le16_to_cpu(f_hdr->frame_control);

                if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
                    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
                    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
                        continue;

                if (entry->first_frag_time + 2 * HZ < jiffies) {
                        __skb_queue_purge(&entry->skb_list);
                        continue;
                }
                return entry;
        }

        return NULL;
}


static ieee80211_txrx_result
ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
{
        struct ieee80211_hdr *hdr;
        u16 sc;
        unsigned int frag, seq;
        struct ieee80211_fragment_entry *entry;
        struct sk_buff *skb;

        hdr = (struct ieee80211_hdr *) rx->skb->data;
        sc = le16_to_cpu(hdr->seq_ctrl);
        frag = sc & IEEE80211_SCTL_FRAG;

        if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
                   (rx->skb)->len < 24 ||
                   is_multicast_ether_addr(hdr->addr1))) {
                /* not fragmented */
                goto out;
        }
        I802_DEBUG_INC(rx->local->rx_handlers_fragments);

        seq = (sc & IEEE80211_SCTL_SEQ) >> 4;

        if (frag == 0) {
                /* This is the first fragment of a new frame. */
                entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
                                                 rx->u.rx.queue, &(rx->skb));
                if (rx->key && rx->key->alg == ALG_CCMP &&
                    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
                        /* Store CCMP PN so that we can verify that the next
                         * fragment has a sequential PN value. */
                        entry->ccmp = 1;
                        memcpy(entry->last_pn,
                               rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
                               CCMP_PN_LEN);
                }
                return TXRX_QUEUED;
        }

        /* This is a fragment for a frame that should already be pending in
         * fragment cache. Add this fragment to the end of the pending entry.
         */
        entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
                                          rx->u.rx.queue, hdr);
        if (!entry) {
                I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
                return TXRX_DROP;
        }

        /* Verify that MPDUs within one MSDU have sequential PN values.
         * (IEEE 802.11i, 8.3.3.4.5) */
        if (entry->ccmp) {
                int i;
                u8 pn[CCMP_PN_LEN], *rpn;
                if (!rx->key || rx->key->alg != ALG_CCMP)
                        return TXRX_DROP;
                memcpy(pn, entry->last_pn, CCMP_PN_LEN);
                for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
                        pn[i]++;
                        if (pn[i])
                                break;
                }
                rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
                if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
                        printk(KERN_DEBUG "%s: defrag: CCMP PN not sequential"
                               " A2=" MAC_FMT " PN=%02x%02x%02x%02x%02x%02x "
                               "(expected %02x%02x%02x%02x%02x%02x)\n",
                               rx->dev->name, MAC_ARG(hdr->addr2),
                               rpn[0], rpn[1], rpn[2], rpn[3], rpn[4], rpn[5],
                               pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
                        return TXRX_DROP;
                }
                memcpy(entry->last_pn, pn, CCMP_PN_LEN);
        }

        skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
        __skb_queue_tail(&entry->skb_list, rx->skb);
        entry->last_frag = frag;
        entry->extra_len += rx->skb->len;
        if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
                rx->skb = NULL;
                return TXRX_QUEUED;
        }

        rx->skb = __skb_dequeue(&entry->skb_list);
        if (skb_tailroom(rx->skb) < entry->extra_len) {
                I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
                if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
                                              GFP_ATOMIC))) {
                        I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
                        __skb_queue_purge(&entry->skb_list);
                        return TXRX_DROP;
                }
        }
        while ((skb = __skb_dequeue(&entry->skb_list)))
                memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);

        /* Complete frame has been reassembled - process it now */
        rx->fragmented = 1;

 out:
        if (rx->sta)
                rx->sta->rx_packets++;
        if (is_multicast_ether_addr(hdr->addr1))
                rx->local->dot11MulticastReceivedFrameCount++;
        else
                ieee80211_led_rx(rx->local);
        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_monitor(struct ieee80211_txrx_data *rx)
{
        if (rx->sdata->type == IEEE80211_IF_TYPE_MNTR) {
                ieee80211_rx_monitor(rx->dev, rx->skb, rx->u.rx.status);
                return TXRX_QUEUED;
        }

        if (rx->u.rx.status->flag & RX_FLAG_RADIOTAP)
                skb_pull(rx->skb, ieee80211_get_radiotap_len(rx->skb));

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
{
        struct ieee80211_hdr *hdr;
        int always_sta_key;
        hdr = (struct ieee80211_hdr *) rx->skb->data;

        /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
        if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
                if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
                             rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
                             hdr->seq_ctrl)) {
                        if (rx->u.rx.ra_match) {
                                rx->local->dot11FrameDuplicateCount++;
                                rx->sta->num_duplicates++;
                        }
                        return TXRX_DROP;
                } else
                        rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
        }

        if ((rx->local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) &&
            rx->skb->len > FCS_LEN)
                skb_trim(rx->skb, rx->skb->len - FCS_LEN);

        if (unlikely(rx->skb->len < 16)) {
                I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
                return TXRX_DROP;
        }

        if (!rx->u.rx.ra_match)
                rx->skb->pkt_type = PACKET_OTHERHOST;
        else if (compare_ether_addr(rx->dev->dev_addr, hdr->addr1) == 0)
                rx->skb->pkt_type = PACKET_HOST;
        else if (is_multicast_ether_addr(hdr->addr1)) {
                if (is_broadcast_ether_addr(hdr->addr1))
                        rx->skb->pkt_type = PACKET_BROADCAST;
                else
                        rx->skb->pkt_type = PACKET_MULTICAST;
        } else
                rx->skb->pkt_type = PACKET_OTHERHOST;

        /* Drop disallowed frame classes based on STA auth/assoc state;
         * IEEE 802.11, Chap 5.5.
         *
         * 80211.o does filtering only based on association state, i.e., it
         * drops Class 3 frames from not associated stations. hostapd sends
         * deauth/disassoc frames when needed. In addition, hostapd is
         * responsible for filtering on both auth and assoc states.
         */
        if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
                      ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
                       (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
                     rx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
                     (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
                if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
                     !(rx->fc & IEEE80211_FCTL_TODS) &&
                     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
                    || !rx->u.rx.ra_match) {
                        /* Drop IBSS frames and frames for other hosts
                         * silently. */
                        return TXRX_DROP;
                }

                if (!rx->local->apdev)
                        return TXRX_DROP;

                ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
                                  ieee80211_msg_sta_not_assoc);
                return TXRX_QUEUED;
        }

        if (rx->sdata->type == IEEE80211_IF_TYPE_STA)
                always_sta_key = 0;
        else
                always_sta_key = 1;

        if (rx->sta && rx->sta->key && always_sta_key) {
                rx->key = rx->sta->key;
        } else {
                if (rx->sta && rx->sta->key)
                        rx->key = rx->sta->key;
                else
                        rx->key = rx->sdata->default_key;

                if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
                    rx->fc & IEEE80211_FCTL_PROTECTED) {
                        int keyidx = ieee80211_wep_get_keyidx(rx->skb);

                        if (keyidx >= 0 && keyidx < NUM_DEFAULT_KEYS &&
                            (!rx->sta || !rx->sta->key || keyidx > 0))
                                rx->key = rx->sdata->keys[keyidx];

                        if (!rx->key) {
                                if (!rx->u.rx.ra_match)
                                        return TXRX_DROP;
                                printk(KERN_DEBUG "%s: RX WEP frame with "
                                       "unknown keyidx %d (A1=" MAC_FMT " A2="
                                       MAC_FMT " A3=" MAC_FMT ")\n",
                                       rx->dev->name, keyidx,
                                       MAC_ARG(hdr->addr1),
                                       MAC_ARG(hdr->addr2),
                                       MAC_ARG(hdr->addr3));
                                if (!rx->local->apdev)
                                        return TXRX_DROP;
                                ieee80211_rx_mgmt(
                                        rx->local, rx->skb, rx->u.rx.status,
                                        ieee80211_msg_wep_frame_unknown_key);
                                return TXRX_QUEUED;
                        }
                }
        }

        if (rx->fc & IEEE80211_FCTL_PROTECTED && rx->key && rx->u.rx.ra_match) {
                rx->key->tx_rx_count++;
                if (unlikely(rx->local->key_tx_rx_threshold &&
                             rx->key->tx_rx_count >
                             rx->local->key_tx_rx_threshold)) {
                        ieee80211_key_threshold_notify(rx->dev, rx->key,
                                                       rx->sta);
                }
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
{
        struct sta_info *sta = rx->sta;
        struct net_device *dev = rx->dev;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;

        if (!sta)
                return TXRX_CONTINUE;

        /* Update last_rx only for IBSS packets which are for the current
         * BSSID to avoid keeping the current IBSS network alive in cases where
         * other STAs are using different BSSID. */
        if (rx->sdata->type == IEEE80211_IF_TYPE_IBSS) {
                u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len);
                if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
                        sta->last_rx = jiffies;
        } else
        if (!is_multicast_ether_addr(hdr->addr1) ||
            rx->sdata->type == IEEE80211_IF_TYPE_STA) {
                /* Update last_rx only for unicast frames in order to prevent
                 * the Probe Request frames (the only broadcast frames from a
                 * STA in infrastructure mode) from keeping a connection alive.
                 */
                sta->last_rx = jiffies;
        }

        if (!rx->u.rx.ra_match)
                return TXRX_CONTINUE;

        sta->rx_fragments++;
        sta->rx_bytes += rx->skb->len;
        sta->last_rssi = (sta->last_rssi * 15 +
                          rx->u.rx.status->ssi) / 16;
        sta->last_signal = (sta->last_signal * 15 +
                            rx->u.rx.status->signal) / 16;
        sta->last_noise = (sta->last_noise * 15 +
                           rx->u.rx.status->noise) / 16;

        if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
                /* Change STA power saving mode only in the end of a frame
                 * exchange sequence */
                if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
                        rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
                else if (!(sta->flags & WLAN_STA_PS) &&
                         (rx->fc & IEEE80211_FCTL_PM))
                        ap_sta_ps_start(dev, sta);
        }

        /* Drop data::nullfunc frames silently, since they are used only to
         * control station power saving mode. */
        if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
            (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
                I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
                /* Update counter and free packet here to avoid counting this
                 * as a dropped packed. */
                sta->rx_packets++;
                dev_kfree_skb(rx->skb);
                return TXRX_QUEUED;
        }

        return TXRX_CONTINUE;
} /* ieee80211_rx_h_sta_process */


static ieee80211_txrx_result
ieee80211_rx_h_wep_weak_iv_detection(struct ieee80211_txrx_data *rx)
{
        if (!rx->sta || !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
            (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
            !rx->key || rx->key->alg != ALG_WEP || !rx->u.rx.ra_match)
                return TXRX_CONTINUE;

        /* Check for weak IVs, if hwaccel did not remove IV from the frame */
        if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) ||
            rx->key->force_sw_encrypt) {
                u8 *iv = ieee80211_wep_is_weak_iv(rx->skb, rx->key);
                if (iv) {
                        rx->sta->wep_weak_iv_count++;
                }
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_wep_decrypt(struct ieee80211_txrx_data *rx)
{
        /* If the device handles decryption totally, skip this test */
        if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
                return TXRX_CONTINUE;

        if ((rx->key && rx->key->alg != ALG_WEP) ||
            !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
            ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
                return TXRX_CONTINUE;

        if (!rx->key) {
                printk(KERN_DEBUG "%s: RX WEP frame, but no key set\n",
                       rx->dev->name);
                return TXRX_DROP;
        }

        if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED) ||
            rx->key->force_sw_encrypt) {
                if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key)) {
                        printk(KERN_DEBUG "%s: RX WEP frame, decrypt "
                               "failed\n", rx->dev->name);
                        return TXRX_DROP;
                }
        } else if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
                ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
                /* remove ICV */
                skb_trim(rx->skb, rx->skb->len - 4);
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
{
        if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
            rx->sdata->type != IEEE80211_IF_TYPE_STA && rx->u.rx.ra_match) {
                /* Pass both encrypted and unencrypted EAPOL frames to user
                 * space for processing. */
                if (!rx->local->apdev)
                        return TXRX_DROP;
                ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
                                  ieee80211_msg_normal);
                return TXRX_QUEUED;
        }

        if (unlikely(rx->sdata->ieee802_1x &&
                     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
                     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
                     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)) &&
                     !ieee80211_is_eapol(rx->skb))) {
#ifdef CONFIG_MAC80211_DEBUG
                struct ieee80211_hdr *hdr =
                        (struct ieee80211_hdr *) rx->skb->data;
                printk(KERN_DEBUG "%s: dropped frame from " MAC_FMT
                       " (unauthorized port)\n", rx->dev->name,
                       MAC_ARG(hdr->addr2));
#endif /* CONFIG_MAC80211_DEBUG */
                return TXRX_DROP;
        }

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
{
        /*  If the device handles decryption totally, skip this test */
        if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
                return TXRX_CONTINUE;

        /* Drop unencrypted frames if key is set. */
        if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
                     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
                     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
                     (rx->key || rx->sdata->drop_unencrypted) &&
                     (rx->sdata->eapol == 0 ||
                      !ieee80211_is_eapol(rx->skb)))) {
                printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
                       "encryption\n", rx->dev->name);
                return TXRX_DROP;
        }
        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
{
        struct ieee80211_sub_if_data *sdata;

        if (!rx->u.rx.ra_match)
                return TXRX_DROP;

        sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
        if ((sdata->type == IEEE80211_IF_TYPE_STA ||
             sdata->type == IEEE80211_IF_TYPE_IBSS) &&
            !rx->local->user_space_mlme) {
                ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
        } else {
                /* Management frames are sent to hostapd for processing */
                if (!rx->local->apdev)
                        return TXRX_DROP;
                ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
                                  ieee80211_msg_normal);
        }
        return TXRX_QUEUED;
}


static ieee80211_txrx_result
ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
{
        struct ieee80211_local *local = rx->local;
        struct sk_buff *skb = rx->skb;

        if (unlikely(local->sta_scanning != 0)) {
                ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
                return TXRX_QUEUED;
        }

        if (unlikely(rx->u.rx.in_scan)) {
                /* scanning finished during invoking of handlers */
                I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
                return TXRX_DROP;
        }

        return TXRX_CONTINUE;
}


static void ieee80211_rx_michael_mic_report(struct net_device *dev,
                                            struct ieee80211_hdr *hdr,
                                            struct sta_info *sta,
                                            struct ieee80211_txrx_data *rx)
{
        int keyidx, hdrlen;

        hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
        if (rx->skb->len >= hdrlen + 4)
                keyidx = rx->skb->data[hdrlen + 3] >> 6;
        else
                keyidx = -1;

        /* TODO: verify that this is not triggered by fragmented
         * frames (hw does not verify MIC for them). */
        printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
               "failure from " MAC_FMT " to " MAC_FMT " keyidx=%d\n",
               dev->name, MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr1), keyidx);

        if (!sta) {
                /* Some hardware versions seem to generate incorrect
                 * Michael MIC reports; ignore them to avoid triggering
                 * countermeasures. */
                printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
                       "error for unknown address " MAC_FMT "\n",
                       dev->name, MAC_ARG(hdr->addr2));
                goto ignore;
        }

        if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
                printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
                       "error for a frame with no ISWEP flag (src "
                       MAC_FMT ")\n", dev->name, MAC_ARG(hdr->addr2));
                goto ignore;
        }

        if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
            rx->sdata->type == IEEE80211_IF_TYPE_AP) {
                keyidx = ieee80211_wep_get_keyidx(rx->skb);
                /* AP with Pairwise keys support should never receive Michael
                 * MIC errors for non-zero keyidx because these are reserved
                 * for group keys and only the AP is sending real multicast
                 * frames in BSS. */
                if (keyidx) {
                        printk(KERN_DEBUG "%s: ignored Michael MIC error for "
                               "a frame with non-zero keyidx (%d) (src " MAC_FMT
                               ")\n", dev->name, keyidx, MAC_ARG(hdr->addr2));
                        goto ignore;
                }
        }

        if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
            ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
             (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
                printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
                       "error for a frame that cannot be encrypted "
                       "(fc=0x%04x) (src " MAC_FMT ")\n",
                       dev->name, rx->fc, MAC_ARG(hdr->addr2));
                goto ignore;
        }

        do {
                union iwreq_data wrqu;
                char *buf = kmalloc(128, GFP_ATOMIC);
                if (!buf)
                        break;

                /* TODO: needed parameters: count, key type, TSC */
                sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
                        "keyid=%d %scast addr=" MAC_FMT ")",
                        keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni",
                        MAC_ARG(hdr->addr2));
                memset(&wrqu, 0, sizeof(wrqu));
                wrqu.data.length = strlen(buf);
                wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
                kfree(buf);
        } while (0);

        /* TODO: consider verifying the MIC error report with software
         * implementation if we get too many spurious reports from the
         * hardware. */
        if (!rx->local->apdev)
                goto ignore;
        ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
                          ieee80211_msg_michael_mic_failure);
        return;

 ignore:
        dev_kfree_skb(rx->skb);
        rx->skb = NULL;
}

static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
                                struct ieee80211_local *local,
                                ieee80211_rx_handler *handlers,
                                struct ieee80211_txrx_data *rx,
                                struct sta_info *sta)
{
        ieee80211_rx_handler *handler;
        ieee80211_txrx_result res = TXRX_DROP;

        for (handler = handlers; *handler != NULL; handler++) {
                res = (*handler)(rx);
                if (res != TXRX_CONTINUE) {
                        if (res == TXRX_DROP) {
                                I802_DEBUG_INC(local->rx_handlers_drop);
                                if (sta)
                                        sta->rx_dropped++;
                        }
                        if (res == TXRX_QUEUED)
                                I802_DEBUG_INC(local->rx_handlers_queued);
                        break;
                }
        }

        if (res == TXRX_DROP) {
                dev_kfree_skb(rx->skb);
        }
        return res;
}

static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
                                                ieee80211_rx_handler *handlers,
                                                struct ieee80211_txrx_data *rx,
                                                struct sta_info *sta)
{
        if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
            TXRX_CONTINUE)
                dev_kfree_skb(rx->skb);
}

/*
 * This is the receive path handler. It is called by a low level driver when an
 * 802.11 MPDU is received from the hardware.
 */
void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
                    struct ieee80211_rx_status *status)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_sub_if_data *sdata;
        struct sta_info *sta;
        struct ieee80211_hdr *hdr;
        struct ieee80211_txrx_data rx;
        u16 type;
        int multicast;
        int radiotap_len = 0;

        if (status->flag & RX_FLAG_RADIOTAP) {
                radiotap_len = ieee80211_get_radiotap_len(skb);
                skb_pull(skb, radiotap_len);
        }

        hdr = (struct ieee80211_hdr *) skb->data;
        memset(&rx, 0, sizeof(rx));
        rx.skb = skb;
        rx.local = local;

        rx.u.rx.status = status;
        rx.fc = skb->len >= 2 ? le16_to_cpu(hdr->frame_control) : 0;
        type = rx.fc & IEEE80211_FCTL_FTYPE;
        if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
                local->dot11ReceivedFragmentCount++;
        multicast = is_multicast_ether_addr(hdr->addr1);

        if (skb->len >= 16)
                sta = rx.sta = sta_info_get(local, hdr->addr2);
        else
                sta = rx.sta = NULL;

        if (sta) {
                rx.dev = sta->dev;
                rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
        }

        if ((status->flag & RX_FLAG_MMIC_ERROR)) {
                ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
                goto end;
        }

        if (unlikely(local->sta_scanning))
                rx.u.rx.in_scan = 1;

        if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
                                           sta) != TXRX_CONTINUE)
                goto end;
        skb = rx.skb;

        skb_push(skb, radiotap_len);
        if (sta && !sta->assoc_ap && !(sta->flags & WLAN_STA_WDS) &&
            !local->iff_promiscs && !multicast) {
                rx.u.rx.ra_match = 1;
                ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
                                             sta);
        } else {
                struct ieee80211_sub_if_data *prev = NULL;
                struct sk_buff *skb_new;
                u8 *bssid = ieee80211_get_bssid(hdr, skb->len - radiotap_len);

                read_lock(&local->sub_if_lock);
                list_for_each_entry(sdata, &local->sub_if_list, list) {
                        rx.u.rx.ra_match = 1;
                        switch (sdata->type) {
                        case IEEE80211_IF_TYPE_STA:
                                if (!bssid)
                                        continue;
                                if (!ieee80211_bssid_match(bssid,
                                                        sdata->u.sta.bssid)) {
                                        if (!rx.u.rx.in_scan)
                                                continue;
                                        rx.u.rx.ra_match = 0;
                                } else if (!multicast &&
                                           compare_ether_addr(sdata->dev->dev_addr,
                                                              hdr->addr1) != 0) {
                                        if (!sdata->promisc)
                                                continue;
                                        rx.u.rx.ra_match = 0;
                                }
                                break;
                        case IEEE80211_IF_TYPE_IBSS:
                                if (!bssid)
                                        continue;
                                if (!ieee80211_bssid_match(bssid,
                                                        sdata->u.sta.bssid)) {
                                        if (!rx.u.rx.in_scan)
                                                continue;
                                        rx.u.rx.ra_match = 0;
                                } else if (!multicast &&
                                           compare_ether_addr(sdata->dev->dev_addr,
                                                              hdr->addr1) != 0) {
                                        if (!sdata->promisc)
                                                continue;
                                        rx.u.rx.ra_match = 0;
                                } else if (!sta)
                                        sta = rx.sta =
                                                ieee80211_ibss_add_sta(sdata->dev,
                                                                       skb, bssid,
                                                                       hdr->addr2);
                                break;
                        case IEEE80211_IF_TYPE_AP:
                                if (!bssid) {
                                        if (compare_ether_addr(sdata->dev->dev_addr,
                                                               hdr->addr1) != 0)
                                                continue;
                                } else if (!ieee80211_bssid_match(bssid,
                                                        sdata->dev->dev_addr)) {
                                        if (!rx.u.rx.in_scan)
                                                continue;
                                        rx.u.rx.ra_match = 0;
                                }
                                if (sdata->dev == local->mdev &&
                                    !rx.u.rx.in_scan)
                                        /* do not receive anything via
                                         * master device when not scanning */
                                        continue;
                                break;
                        case IEEE80211_IF_TYPE_WDS:
                                if (bssid ||
                                    (rx.fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
                                        continue;
                                if (compare_ether_addr(sdata->u.wds.remote_addr,
                                                       hdr->addr2) != 0)
                                        continue;
                                break;
                        }

                        if (prev) {
                                skb_new = skb_copy(skb, GFP_ATOMIC);
                                if (!skb_new) {
                                        if (net_ratelimit())
                                                printk(KERN_DEBUG "%s: failed to copy "
                                                       "multicast frame for %s",
                                                       local->mdev->name, prev->dev->name);
                                        continue;
                                }
                                rx.skb = skb_new;
                                rx.dev = prev->dev;
                                rx.sdata = prev;
                                ieee80211_invoke_rx_handlers(local,
                                                             local->rx_handlers,
                                                             &rx, sta);
                        }
                        prev = sdata;
                }
                if (prev) {
                        rx.skb = skb;
                        rx.dev = prev->dev;
                        rx.sdata = prev;
                        ieee80211_invoke_rx_handlers(local, local->rx_handlers,
                                                     &rx, sta);
                } else
                        dev_kfree_skb(skb);
                read_unlock(&local->sub_if_lock);
        }

  end:
        if (sta)
                sta_info_put(sta);
}
EXPORT_SYMBOL(__ieee80211_rx);

static ieee80211_txrx_result
ieee80211_tx_h_load_stats(struct ieee80211_txrx_data *tx)
{
        struct ieee80211_local *local = tx->local;
        struct ieee80211_hw_mode *mode = tx->u.tx.mode;
        struct sk_buff *skb = tx->skb;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        u32 load = 0, hdrtime;

        /* TODO: this could be part of tx_status handling, so that the number
         * of retries would be known; TX rate should in that case be stored
         * somewhere with the packet */

        /* Estimate total channel use caused by this frame */

        /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
         * 1 usec = 1/8 * (1080 / 10) = 13.5 */

        if (mode->mode == MODE_IEEE80211A ||
            mode->mode == MODE_ATHEROS_TURBO ||
            mode->mode == MODE_ATHEROS_TURBOG ||
            (mode->mode == MODE_IEEE80211G &&
             tx->u.tx.rate->flags & IEEE80211_RATE_ERP))
                hdrtime = CHAN_UTIL_HDR_SHORT;
        else
                hdrtime = CHAN_UTIL_HDR_LONG;

        load = hdrtime;
        if (!is_multicast_ether_addr(hdr->addr1))
                load += hdrtime;

        if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
                load += 2 * hdrtime;
        else if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
                load += hdrtime;

        load += skb->len * tx->u.tx.rate->rate_inv;

        if (tx->u.tx.extra_frag) {
                int i;
                for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
                        load += 2 * hdrtime;
                        load += tx->u.tx.extra_frag[i]->len *
                                tx->u.tx.rate->rate;
                }
        }

        /* Divide channel_use by 8 to avoid wrapping around the counter */
        load >>= CHAN_UTIL_SHIFT;
        local->channel_use_raw += load;
        if (tx->sta)
                tx->sta->channel_use_raw += load;
        tx->sdata->channel_use_raw += load;

        return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
{
        struct ieee80211_local *local = rx->local;
        struct sk_buff *skb = rx->skb;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        u32 load = 0, hdrtime;
        struct ieee80211_rate *rate;
        struct ieee80211_hw_mode *mode = local->hw.conf.mode;
        int i;

        /* Estimate total channel use caused by this frame */

        if (unlikely(mode->num_rates < 0))
                return TXRX_CONTINUE;

        rate = &mode->rates[0];
        for (i = 0; i < mode->num_rates; i++) {
                if (mode->rates[i].val == rx->u.rx.status->rate) {
                        rate = &mode->rates[i];
                        break;
                }
        }

        /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
         * 1 usec = 1/8 * (1080 / 10) = 13.5 */

        if (mode->mode == MODE_IEEE80211A ||
            mode->mode == MODE_ATHEROS_TURBO ||
            mode->mode == MODE_ATHEROS_TURBOG ||
            (mode->mode == MODE_IEEE80211G &&
             rate->flags & IEEE80211_RATE_ERP))
                hdrtime = CHAN_UTIL_HDR_SHORT;
        else
                hdrtime = CHAN_UTIL_HDR_LONG;

        load = hdrtime;
        if (!is_multicast_ether_addr(hdr->addr1))
                load += hdrtime;

        load += skb->len * rate->rate_inv;

        /* Divide channel_use by 8 to avoid wrapping around the counter */
        load >>= CHAN_UTIL_SHIFT;
        local->channel_use_raw += load;
        if (rx->sta)
                rx->sta->channel_use_raw += load;
        rx->u.rx.load = load;

        return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
{
        rx->sdata->channel_use_raw += rx->u.rx.load;
        return TXRX_CONTINUE;
}

static void ieee80211_stat_refresh(unsigned long data)
{
        struct ieee80211_local *local = (struct ieee80211_local *) data;
        struct sta_info *sta;
        struct ieee80211_sub_if_data *sdata;

        if (!local->stat_time)
                return;

        /* go through all stations */
        spin_lock_bh(&local->sta_lock);
        list_for_each_entry(sta, &local->sta_list, list) {
                sta->channel_use = (sta->channel_use_raw / local->stat_time) /
                        CHAN_UTIL_PER_10MS;
                sta->channel_use_raw = 0;
        }
        spin_unlock_bh(&local->sta_lock);

        /* go through all subinterfaces */
        read_lock(&local->sub_if_lock);
        list_for_each_entry(sdata, &local->sub_if_list, list) {
                sdata->channel_use = (sdata->channel_use_raw /
                                      local->stat_time) / CHAN_UTIL_PER_10MS;
                sdata->channel_use_raw = 0;
        }
        read_unlock(&local->sub_if_lock);

        /* hardware interface */
        local->channel_use = (local->channel_use_raw /
                              local->stat_time) / CHAN_UTIL_PER_10MS;
        local->channel_use_raw = 0;

        local->stat_timer.expires = jiffies + HZ * local->stat_time / 100;
        add_timer(&local->stat_timer);
}


/* This is a version of the rx handler that can be called from hard irq
 * context. Post the skb on the queue and schedule the tasklet */
void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
                          struct ieee80211_rx_status *status)
{
        struct ieee80211_local *local = hw_to_local(hw);

        BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));

        skb->dev = local->mdev;
        /* copy status into skb->cb for use by tasklet */
        memcpy(skb->cb, status, sizeof(*status));
        skb->pkt_type = IEEE80211_RX_MSG;
        skb_queue_tail(&local->skb_queue, skb);
        tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_rx_irqsafe);

void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
                                 struct sk_buff *skb,
                                 struct ieee80211_tx_status *status)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_tx_status *saved;
        int tmp;

        skb->dev = local->mdev;
        saved = kmalloc(sizeof(struct ieee80211_tx_status), GFP_ATOMIC);
        if (unlikely(!saved)) {
                if (net_ratelimit())
                        printk(KERN_WARNING "%s: Not enough memory, "
                               "dropping tx status", skb->dev->name);
                /* should be dev_kfree_skb_irq, but due to this function being
                 * named _irqsafe instead of just _irq we can't be sure that
                 * people won't call it from non-irq contexts */
                dev_kfree_skb_any(skb);
                return;
        }
        memcpy(saved, status, sizeof(struct ieee80211_tx_status));
        /* copy pointer to saved status into skb->cb for use by tasklet */
        memcpy(skb->cb, &saved, sizeof(saved));

        skb->pkt_type = IEEE80211_TX_STATUS_MSG;
        skb_queue_tail(status->control.flags & IEEE80211_TXCTL_REQ_TX_STATUS ?
                       &local->skb_queue : &local->skb_queue_unreliable, skb);
        tmp = skb_queue_len(&local->skb_queue) +
                skb_queue_len(&local->skb_queue_unreliable);
        while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
               (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                memcpy(&saved, skb->cb, sizeof(saved));
                kfree(saved);
                dev_kfree_skb_irq(skb);
                tmp--;
                I802_DEBUG_INC(local->tx_status_drop);
        }
        tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);

static void ieee80211_tasklet_handler(unsigned long data)
{
        struct ieee80211_local *local = (struct ieee80211_local *) data;
        struct sk_buff *skb;
        struct ieee80211_rx_status rx_status;
        struct ieee80211_tx_status *tx_status;

        while ((skb = skb_dequeue(&local->skb_queue)) ||
               (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                switch (skb->pkt_type) {
                case IEEE80211_RX_MSG:
                        /* status is in skb->cb */
                        memcpy(&rx_status, skb->cb, sizeof(rx_status));
                        /* Clear skb->type in order to not confuse kernel
                         * netstack. */
                        skb->pkt_type = 0;
                        __ieee80211_rx(local_to_hw(local), skb, &rx_status);
                        break;
                case IEEE80211_TX_STATUS_MSG:
                        /* get pointer to saved status out of skb->cb */
                        memcpy(&tx_status, skb->cb, sizeof(tx_status));
                        skb->pkt_type = 0;
                        ieee80211_tx_status(local_to_hw(local),
                                            skb, tx_status);
                        kfree(tx_status);
                        break;
                default: /* should never get here! */
                        printk(KERN_ERR "%s: Unknown message type (%d)\n",
                               local->mdev->name, skb->pkt_type);
                        dev_kfree_skb(skb);
                        break;
                }
        }
}


/* Remove added headers (e.g., QoS control), encryption header/MIC, etc. to
 * make a prepared TX frame (one that has been given to hw) to look like brand
 * new IEEE 802.11 frame that is ready to go through TX processing again.
 * Also, tx_packet_data in cb is restored from tx_control. */
static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
                                      struct ieee80211_key *key,
                                      struct sk_buff *skb,
                                      struct ieee80211_tx_control *control)
{
        int hdrlen, iv_len, mic_len;
        struct ieee80211_tx_packet_data *pkt_data;

        pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
        pkt_data->ifindex = control->ifindex;
        pkt_data->mgmt_iface = (control->type == IEEE80211_IF_TYPE_MGMT);
        pkt_data->req_tx_status = !!(control->flags & IEEE80211_TXCTL_REQ_TX_STATUS);
        pkt_data->do_not_encrypt = !!(control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT);
        pkt_data->requeue = !!(control->flags & IEEE80211_TXCTL_REQUEUE);
        pkt_data->queue = control->queue;

        hdrlen = ieee80211_get_hdrlen_from_skb(skb);

        if (!key)
                goto no_key;

        switch (key->alg) {
        case ALG_WEP:
                iv_len = WEP_IV_LEN;
                mic_len = WEP_ICV_LEN;
                break;
        case ALG_TKIP:
                iv_len = TKIP_IV_LEN;
                mic_len = TKIP_ICV_LEN;
                break;
        case ALG_CCMP:
                iv_len = CCMP_HDR_LEN;
                mic_len = CCMP_MIC_LEN;
                break;
        default:
                goto no_key;
        }

        if (skb->len >= mic_len && key->force_sw_encrypt)
                skb_trim(skb, skb->len - mic_len);
        if (skb->len >= iv_len && skb->len > hdrlen) {
                memmove(skb->data + iv_len, skb->data, hdrlen);
                skb_pull(skb, iv_len);
        }

no_key:
        {
                struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
                u16 fc = le16_to_cpu(hdr->frame_control);
                if ((fc & 0x8C) == 0x88) /* QoS Control Field */ {
                        fc &= ~IEEE80211_STYPE_QOS_DATA;
                        hdr->frame_control = cpu_to_le16(fc);
                        memmove(skb->data + 2, skb->data, hdrlen - 2);
                        skb_pull(skb, 2);
                }
        }
}


void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb,
                         struct ieee80211_tx_status *status)
{
        struct sk_buff *skb2;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        struct ieee80211_local *local = hw_to_local(hw);
        u16 frag, type;
        u32 msg_type;

        if (!status) {
                printk(KERN_ERR
                       "%s: ieee80211_tx_status called with NULL status\n",
                       local->mdev->name);
                dev_kfree_skb(skb);
                return;
        }

        if (status->excessive_retries) {
                struct sta_info *sta;
                sta = sta_info_get(local, hdr->addr1);
                if (sta) {
                        if (sta->flags & WLAN_STA_PS) {
                                /* The STA is in power save mode, so assume
                                 * that this TX packet failed because of that.
                                 */
                                status->excessive_retries = 0;
                                status->flags |= IEEE80211_TX_STATUS_TX_FILTERED;
                        }
                        sta_info_put(sta);
                }
        }

        if (status->flags & IEEE80211_TX_STATUS_TX_FILTERED) {
                struct sta_info *sta;
                sta = sta_info_get(local, hdr->addr1);
                if (sta) {
                        sta->tx_filtered_count++;

                        /* Clear the TX filter mask for this STA when sending
                         * the next packet. If the STA went to power save mode,
                         * this will happen when it is waking up for the next
                         * time. */
                        sta->clear_dst_mask = 1;

                        /* TODO: Is the WLAN_STA_PS flag always set here or is
                         * the race between RX and TX status causing some
                         * packets to be filtered out before 80211.o gets an
                         * update for PS status? This seems to be the case, so
                         * no changes are likely to be needed. */
                        if (sta->flags & WLAN_STA_PS &&
                            skb_queue_len(&sta->tx_filtered) <
                            STA_MAX_TX_BUFFER) {
                                ieee80211_remove_tx_extra(local, sta->key,
                                                          skb,
                                                          &status->control);
                                skb_queue_tail(&sta->tx_filtered, skb);
                        } else if (!(sta->flags & WLAN_STA_PS) &&
                                   !(status->control.flags & IEEE80211_TXCTL_REQUEUE)) {
                                /* Software retry the packet once */
                                status->control.flags |= IEEE80211_TXCTL_REQUEUE;
                                ieee80211_remove_tx_extra(local, sta->key,
                                                          skb,
                                                          &status->control);
                                dev_queue_xmit(skb);
                        } else {
                                if (net_ratelimit()) {
                                        printk(KERN_DEBUG "%s: dropped TX "
                                               "filtered frame queue_len=%d "
                                               "PS=%d @%lu\n",
                                               local->mdev->name,
                                               skb_queue_len(
                                                       &sta->tx_filtered),
                                               !!(sta->flags & WLAN_STA_PS),
                                               jiffies);
                                }
                                dev_kfree_skb(skb);
                        }
                        sta_info_put(sta);
                        return;
                }
        } else {
                /* FIXME: STUPID to call this with both local and local->mdev */
                rate_control_tx_status(local, local->mdev, skb, status);
        }

        ieee80211_led_tx(local, 0);

        /* SNMP counters
         * Fragments are passed to low-level drivers as separate skbs, so these
         * are actually fragments, not frames. Update frame counters only for
         * the first fragment of the frame. */

        frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
        type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;

        if (status->flags & IEEE80211_TX_STATUS_ACK) {
                if (frag == 0) {
                        local->dot11TransmittedFrameCount++;
                        if (is_multicast_ether_addr(hdr->addr1))
                                local->dot11MulticastTransmittedFrameCount++;
                        if (status->retry_count > 0)
                                local->dot11RetryCount++;
                        if (status->retry_count > 1)
                                local->dot11MultipleRetryCount++;
                }

                /* This counter shall be incremented for an acknowledged MPDU
                 * with an individual address in the address 1 field or an MPDU
                 * with a multicast address in the address 1 field of type Data
                 * or Management. */
                if (!is_multicast_ether_addr(hdr->addr1) ||
                    type == IEEE80211_FTYPE_DATA ||
                    type == IEEE80211_FTYPE_MGMT)
                        local->dot11TransmittedFragmentCount++;
        } else {
                if (frag == 0)
                        local->dot11FailedCount++;
        }

        if (!(status->control.flags & IEEE80211_TXCTL_REQ_TX_STATUS)
            || unlikely(!local->apdev)) {
                dev_kfree_skb(skb);
                return;
        }

        msg_type = (status->flags & IEEE80211_TX_STATUS_ACK) ?
                ieee80211_msg_tx_callback_ack : ieee80211_msg_tx_callback_fail;

        /* skb was the original skb used for TX. Clone it and give the clone
         * to netif_rx(). Free original skb. */
        skb2 = skb_copy(skb, GFP_ATOMIC);
        if (!skb2) {
                dev_kfree_skb(skb);
                return;
        }
        dev_kfree_skb(skb);
        skb = skb2;

        /* Send frame to hostapd */
        ieee80211_rx_mgmt(local, skb, NULL, msg_type);
}
EXPORT_SYMBOL(ieee80211_tx_status);

/* TODO: implement register/unregister functions for adding TX/RX handlers
 * into ordered list */

/* rx_pre handlers don't have dev and sdata fields available in
 * ieee80211_txrx_data */
static ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
{
        ieee80211_rx_h_parse_qos,
        ieee80211_rx_h_load_stats,
        NULL
};

static ieee80211_rx_handler ieee80211_rx_handlers[] =
{
        ieee80211_rx_h_if_stats,
        ieee80211_rx_h_monitor,
        ieee80211_rx_h_passive_scan,
        ieee80211_rx_h_check,
        ieee80211_rx_h_sta_process,
        ieee80211_rx_h_ccmp_decrypt,
        ieee80211_rx_h_tkip_decrypt,
        ieee80211_rx_h_wep_weak_iv_detection,
        ieee80211_rx_h_wep_decrypt,
        ieee80211_rx_h_defragment,
        ieee80211_rx_h_ps_poll,
        ieee80211_rx_h_michael_mic_verify,
        /* this must be after decryption - so header is counted in MPDU mic
         * must be before pae and data, so QOS_DATA format frames
         * are not passed to user space by these functions
         */
        ieee80211_rx_h_remove_qos_control,
        ieee80211_rx_h_802_1x_pae,
        ieee80211_rx_h_drop_unencrypted,
        ieee80211_rx_h_data,
        ieee80211_rx_h_mgmt,
        NULL
};

static ieee80211_tx_handler ieee80211_tx_handlers[] =
{
        ieee80211_tx_h_check_assoc,
        ieee80211_tx_h_sequence,
        ieee80211_tx_h_ps_buf,
        ieee80211_tx_h_select_key,
        ieee80211_tx_h_michael_mic_add,
        ieee80211_tx_h_fragment,
        ieee80211_tx_h_tkip_encrypt,
        ieee80211_tx_h_ccmp_encrypt,
        ieee80211_tx_h_wep_encrypt,
        ieee80211_tx_h_rate_ctrl,
        ieee80211_tx_h_misc,
        ieee80211_tx_h_load_stats,
        NULL
};


int ieee80211_if_update_wds(struct net_device *dev, u8 *remote_addr)
{
        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct sta_info *sta;

        if (compare_ether_addr(remote_addr, sdata->u.wds.remote_addr) == 0)
                return 0;

        /* Create STA entry for the new peer */
        sta = sta_info_add(local, dev, remote_addr, GFP_KERNEL);
        if (!sta)
                return -ENOMEM;
        sta_info_put(sta);

        /* Remove STA entry for the old peer */
        sta = sta_info_get(local, sdata->u.wds.remote_addr);
        if (sta) {
                sta_info_put(sta);
                sta_info_free(sta, 0);
        } else {
                printk(KERN_DEBUG "%s: could not find STA entry for WDS link "
                       "peer " MAC_FMT "\n",
                       dev->name, MAC_ARG(sdata->u.wds.remote_addr));
        }

        /* Update WDS link data */
        memcpy(&sdata->u.wds.remote_addr, remote_addr, ETH_ALEN);

        return 0;
}

/* Must not be called for mdev and apdev */
void ieee80211_if_setup(struct net_device *dev)
{
        ether_setup(dev);
        dev->hard_start_xmit = ieee80211_subif_start_xmit;
        dev->wireless_handlers = &ieee80211_iw_handler_def;
        dev->set_multicast_list = ieee80211_set_multicast_list;
        dev->change_mtu = ieee80211_change_mtu;
        dev->get_stats = ieee80211_get_stats;
        dev->open = ieee80211_open;
        dev->stop = ieee80211_stop;
        dev->uninit = ieee80211_if_reinit;
        dev->destructor = ieee80211_if_free;
}

void ieee80211_if_mgmt_setup(struct net_device *dev)
{
        ether_setup(dev);
        dev->hard_start_xmit = ieee80211_mgmt_start_xmit;
        dev->change_mtu = ieee80211_change_mtu_apdev;
        dev->get_stats = ieee80211_get_stats;
        dev->open = ieee80211_mgmt_open;
        dev->stop = ieee80211_mgmt_stop;
        dev->type = ARPHRD_IEEE80211_PRISM;
        dev->hard_header_parse = header_parse_80211;
        dev->uninit = ieee80211_if_reinit;
        dev->destructor = ieee80211_if_free;
}

int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
                                 const char *name)
{
        struct rate_control_ref *ref, *old;

        ASSERT_RTNL();
        if (local->open_count || netif_running(local->mdev) ||
            (local->apdev && netif_running(local->apdev)))
                return -EBUSY;

        ref = rate_control_alloc(name, local);
        if (!ref) {
                printk(KERN_WARNING "%s: Failed to select rate control "
                       "algorithm\n", local->mdev->name);
                return -ENOENT;
        }

        old = local->rate_ctrl;
        local->rate_ctrl = ref;
        if (old) {
                rate_control_put(old);
                sta_info_flush(local, NULL);
        }

        printk(KERN_DEBUG "%s: Selected rate control "
               "algorithm '%s'\n", local->mdev->name,
               ref->ops->name);


        return 0;
}

static void rate_control_deinitialize(struct ieee80211_local *local)
{
        struct rate_control_ref *ref;

        ref = local->rate_ctrl;
        local->rate_ctrl = NULL;
        rate_control_put(ref);
}

struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
                                        const struct ieee80211_ops *ops)
{
        struct net_device *mdev;
        struct ieee80211_local *local;
        struct ieee80211_sub_if_data *sdata;
        int priv_size;
        struct wiphy *wiphy;

        /* Ensure 32-byte alignment of our private data and hw private data.
         * We use the wiphy priv data for both our ieee80211_local and for
         * the driver's private data
         *
         * In memory it'll be like this:
         *
         * +-------------------------+
         * | struct wiphy           |
         * +-------------------------+
         * | struct ieee80211_local  |
         * +-------------------------+
         * | driver's private data   |
         * +-------------------------+
         *
         */
        priv_size = ((sizeof(struct ieee80211_local) +
                      NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST) +
                    priv_data_len;

        wiphy = wiphy_new(&mac80211_config_ops, priv_size);

        if (!wiphy)
                return NULL;

        wiphy->privid = mac80211_wiphy_privid;

        local = wiphy_priv(wiphy);
        local->hw.wiphy = wiphy;

        local->hw.priv = (char *)local +
                         ((sizeof(struct ieee80211_local) +
                           NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);

        local->ops = ops;

        /* for now, mdev needs sub_if_data :/ */
        mdev = alloc_netdev(sizeof(struct ieee80211_sub_if_data),
                            "wmaster%d", ether_setup);
        if (!mdev) {
                wiphy_free(wiphy);
                return NULL;
        }

        sdata = IEEE80211_DEV_TO_SUB_IF(mdev);
        mdev->ieee80211_ptr = &sdata->wdev;
        sdata->wdev.wiphy = wiphy;

        local->hw.queues = 1; /* default */

        local->mdev = mdev;
        local->rx_pre_handlers = ieee80211_rx_pre_handlers;
        local->rx_handlers = ieee80211_rx_handlers;
        local->tx_handlers = ieee80211_tx_handlers;

        local->bridge_packets = 1;

        local->rts_threshold = IEEE80211_MAX_RTS_THRESHOLD;
        local->fragmentation_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
        local->short_retry_limit = 7;
        local->long_retry_limit = 4;
        local->hw.conf.radio_enabled = 1;
        local->rate_ctrl_num_up = RATE_CONTROL_NUM_UP;
        local->rate_ctrl_num_down = RATE_CONTROL_NUM_DOWN;

        local->enabled_modes = (unsigned int) -1;

        INIT_LIST_HEAD(&local->modes_list);

        rwlock_init(&local->sub_if_lock);
        INIT_LIST_HEAD(&local->sub_if_list);

        INIT_DELAYED_WORK(&local->scan_work, ieee80211_sta_scan_work);
        init_timer(&local->stat_timer);
        local->stat_timer.function = ieee80211_stat_refresh;
        local->stat_timer.data = (unsigned long) local;
        ieee80211_rx_bss_list_init(mdev);

        sta_info_init(local);

        mdev->hard_start_xmit = ieee80211_master_start_xmit;
        mdev->open = ieee80211_master_open;
        mdev->stop = ieee80211_master_stop;
        mdev->type = ARPHRD_IEEE80211;
        mdev->hard_header_parse = header_parse_80211;

        sdata->type = IEEE80211_IF_TYPE_AP;
        sdata->dev = mdev;
        sdata->local = local;
        sdata->u.ap.force_unicast_rateidx = -1;
        sdata->u.ap.max_ratectrl_rateidx = -1;
        ieee80211_if_sdata_init(sdata);
        list_add_tail(&sdata->list, &local->sub_if_list);

        tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
                     (unsigned long)local);
        tasklet_disable(&local->tx_pending_tasklet);

        tasklet_init(&local->tasklet,
                     ieee80211_tasklet_handler,
                     (unsigned long) local);
        tasklet_disable(&local->tasklet);

        skb_queue_head_init(&local->skb_queue);
        skb_queue_head_init(&local->skb_queue_unreliable);

        return local_to_hw(local);
}
EXPORT_SYMBOL(ieee80211_alloc_hw);

int ieee80211_register_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        const char *name;
        int result;

        result = wiphy_register(local->hw.wiphy);
        if (result < 0)
                return result;

        name = wiphy_dev(local->hw.wiphy)->driver->name;
        local->hw.workqueue = create_singlethread_workqueue(name);
        if (!local->hw.workqueue) {
                result = -ENOMEM;
                goto fail_workqueue;
        }

        debugfs_hw_add(local);

        local->hw.conf.beacon_int = 1000;

        local->wstats_flags |= local->hw.max_rssi ?
                               IW_QUAL_LEVEL_UPDATED : IW_QUAL_LEVEL_INVALID;
        local->wstats_flags |= local->hw.max_signal ?
                               IW_QUAL_QUAL_UPDATED : IW_QUAL_QUAL_INVALID;
        local->wstats_flags |= local->hw.max_noise ?
                               IW_QUAL_NOISE_UPDATED : IW_QUAL_NOISE_INVALID;
        if (local->hw.max_rssi < 0 || local->hw.max_noise < 0)
                local->wstats_flags |= IW_QUAL_DBM;

        result = sta_info_start(local);
        if (result < 0)
                goto fail_sta_info;

        rtnl_lock();
        result = dev_alloc_name(local->mdev, local->mdev->name);
        if (result < 0)
                goto fail_dev;

        memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
        SET_NETDEV_DEV(local->mdev, wiphy_dev(local->hw.wiphy));

        result = register_netdevice(local->mdev);
        if (result < 0)
                goto fail_dev;

        ieee80211_debugfs_add_netdev(IEEE80211_DEV_TO_SUB_IF(local->mdev));

        result = ieee80211_init_rate_ctrl_alg(local, NULL);
        if (result < 0) {
                printk(KERN_DEBUG "%s: Failed to initialize rate control "
                       "algorithm\n", local->mdev->name);
                goto fail_rate;
        }

        result = ieee80211_wep_init(local);

        if (result < 0) {
                printk(KERN_DEBUG "%s: Failed to initialize wep\n",
                       local->mdev->name);
                goto fail_wep;
        }

        ieee80211_install_qdisc(local->mdev);

        /* add one default STA interface */
        result = ieee80211_if_add(local->mdev, "wlan%d", NULL,
                                  IEEE80211_IF_TYPE_STA);
        if (result)
                printk(KERN_WARNING "%s: Failed to add default virtual iface\n",
                       local->mdev->name);

        local->reg_state = IEEE80211_DEV_REGISTERED;
        rtnl_unlock();

        ieee80211_led_init(local);

        return 0;

fail_wep:
        rate_control_deinitialize(local);
fail_rate:
        ieee80211_debugfs_remove_netdev(IEEE80211_DEV_TO_SUB_IF(local->mdev));
        unregister_netdevice(local->mdev);
fail_dev:
        rtnl_unlock();
        sta_info_stop(local);
fail_sta_info:
        debugfs_hw_del(local);
        destroy_workqueue(local->hw.workqueue);
fail_workqueue:
        wiphy_unregister(local->hw.wiphy);
        return result;
}
EXPORT_SYMBOL(ieee80211_register_hw);

int ieee80211_register_hwmode(struct ieee80211_hw *hw,
                              struct ieee80211_hw_mode *mode)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_rate *rate;
        int i;

        INIT_LIST_HEAD(&mode->list);
        list_add_tail(&mode->list, &local->modes_list);

        local->hw_modes |= (1 << mode->mode);
        for (i = 0; i < mode->num_rates; i++) {
                rate = &(mode->rates[i]);
                rate->rate_inv = CHAN_UTIL_RATE_LCM / rate->rate;
        }
        ieee80211_prepare_rates(local, mode);

        if (!local->oper_hw_mode) {
                /* Default to this mode */
                local->hw.conf.phymode = mode->mode;
                local->oper_hw_mode = local->scan_hw_mode = mode;
                local->oper_channel = local->scan_channel = &mode->channels[0];
                local->hw.conf.mode = local->oper_hw_mode;
                local->hw.conf.chan = local->oper_channel;
        }

        if (!(hw->flags & IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED))
                ieee80211_init_client(local->mdev);

        return 0;
}
EXPORT_SYMBOL(ieee80211_register_hwmode);

void ieee80211_unregister_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_sub_if_data *sdata, *tmp;
        struct list_head tmp_list;
        int i;

        tasklet_kill(&local->tx_pending_tasklet);
        tasklet_kill(&local->tasklet);

        rtnl_lock();

        BUG_ON(local->reg_state != IEEE80211_DEV_REGISTERED);

        local->reg_state = IEEE80211_DEV_UNREGISTERED;
        if (local->apdev)
                ieee80211_if_del_mgmt(local);

        write_lock_bh(&local->sub_if_lock);
        list_replace_init(&local->sub_if_list, &tmp_list);
        write_unlock_bh(&local->sub_if_lock);

        list_for_each_entry_safe(sdata, tmp, &tmp_list, list)
                __ieee80211_if_del(local, sdata);

        rtnl_unlock();

        if (local->stat_time)
                del_timer_sync(&local->stat_timer);

        ieee80211_rx_bss_list_deinit(local->mdev);
        ieee80211_clear_tx_pending(local);
        sta_info_stop(local);
        rate_control_deinitialize(local);
        debugfs_hw_del(local);

        for (i = 0; i < NUM_IEEE80211_MODES; i++) {
                kfree(local->supp_rates[i]);
                kfree(local->basic_rates[i]);
        }

        if (skb_queue_len(&local->skb_queue)
                        || skb_queue_len(&local->skb_queue_unreliable))
                printk(KERN_WARNING "%s: skb_queue not empty\n",
                       local->mdev->name);
        skb_queue_purge(&local->skb_queue);
        skb_queue_purge(&local->skb_queue_unreliable);

        destroy_workqueue(local->hw.workqueue);
        wiphy_unregister(local->hw.wiphy);
        ieee80211_wep_free(local);
        ieee80211_led_exit(local);
}
EXPORT_SYMBOL(ieee80211_unregister_hw);

void ieee80211_free_hw(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);

        ieee80211_if_free(local->mdev);
        wiphy_free(local->hw.wiphy);
}
EXPORT_SYMBOL(ieee80211_free_hw);

void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
{
        struct ieee80211_local *local = hw_to_local(hw);

        if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
                               &local->state[queue])) {
                if (test_bit(IEEE80211_LINK_STATE_PENDING,
                             &local->state[queue]))
                        tasklet_schedule(&local->tx_pending_tasklet);
                else
                        if (!ieee80211_qdisc_installed(local->mdev)) {
                                if (queue == 0)
                                        netif_wake_queue(local->mdev);
                        } else
                                __netif_schedule(local->mdev);
        }
}
EXPORT_SYMBOL(ieee80211_wake_queue);

void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
{
        struct ieee80211_local *local = hw_to_local(hw);

        if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
                netif_stop_queue(local->mdev);
        set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}
EXPORT_SYMBOL(ieee80211_stop_queue);

void ieee80211_start_queues(struct ieee80211_hw *hw)
{
        struct ieee80211_local *local = hw_to_local(hw);
        int i;

        for (i = 0; i < local->hw.queues; i++)
                clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
        if (!ieee80211_qdisc_installed(local->mdev))
                netif_start_queue(local->mdev);
}
EXPORT_SYMBOL(ieee80211_start_queues);

void ieee80211_stop_queues(struct ieee80211_hw *hw)
{
        int i;

        for (i = 0; i < hw->queues; i++)
                ieee80211_stop_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_stop_queues);

void ieee80211_wake_queues(struct ieee80211_hw *hw)
{
        int i;

        for (i = 0; i < hw->queues; i++)
                ieee80211_wake_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_wake_queues);

struct net_device_stats *ieee80211_dev_stats(struct net_device *dev)
{
        struct ieee80211_sub_if_data *sdata;
        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        return &sdata->stats;
}

static int __init ieee80211_init(void)
{
        struct sk_buff *skb;
        int ret;

        BUILD_BUG_ON(sizeof(struct ieee80211_tx_packet_data) > sizeof(skb->cb));

        ret = ieee80211_wme_register();
        if (ret) {
                printk(KERN_DEBUG "ieee80211_init: failed to "
                       "initialize WME (err=%d)\n", ret);
                return ret;
        }

        ieee80211_debugfs_netdev_init();

        return 0;
}


static void __exit ieee80211_exit(void)
{
        ieee80211_wme_unregister();
        ieee80211_debugfs_netdev_exit();
}


module_init(ieee80211_init);
module_exit(ieee80211_exit);

MODULE_DESCRIPTION("IEEE 802.11 subsystem");
MODULE_LICENSE("GPL");