hostap_ap.c

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/*
 * Intersil Prism2 driver with Host AP (software access point) support
 * Copyright (c) 2001-2002, SSH Communications Security Corp and Jouni Malinen
 * <[email protected]>
 * Copyright (c) 2002-2005, Jouni Malinen <[email protected]>
 *
 * This file is to be included into hostap.c when S/W AP functionality is
 * compiled.
 *
 * AP:  FIX:
 * - if unicast Class 2 (assoc,reassoc,disassoc) frame received from
 *   unauthenticated STA, send deauth. frame (8802.11: 5.5)
 * - if unicast Class 3 (data with to/from DS,deauth,pspoll) frame received
 *   from authenticated, but unassoc STA, send disassoc frame (8802.11: 5.5)
 * - if unicast Class 3 received from unauthenticated STA, send deauth. frame
 *   (8802.11: 5.5)
 */

#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/random.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/moduleparam.h>

#include "hostap_wlan.h"
#include "hostap.h"
#include "hostap_ap.h"

static int other_ap_policy[MAX_PARM_DEVICES] = { AP_OTHER_AP_SKIP_ALL,
                         DEF_INTS };
module_param_array(other_ap_policy, int, NULL, 0444);
MODULE_PARM_DESC(other_ap_policy, "Other AP beacon monitoring policy (0-3)");

static int ap_max_inactivity[MAX_PARM_DEVICES] = { AP_MAX_INACTIVITY_SEC,
                           DEF_INTS };
module_param_array(ap_max_inactivity, int, NULL, 0444);
MODULE_PARM_DESC(ap_max_inactivity, "AP timeout (in seconds) for station "
         "inactivity");

static int ap_bridge_packets[MAX_PARM_DEVICES] = { 1, DEF_INTS };
module_param_array(ap_bridge_packets, int, NULL, 0444);
MODULE_PARM_DESC(ap_bridge_packets, "Bridge packets directly between "
         "stations");

static int autom_ap_wds[MAX_PARM_DEVICES] = { 0, DEF_INTS };
module_param_array(autom_ap_wds, int, NULL, 0444);
MODULE_PARM_DESC(autom_ap_wds, "Add WDS connections to other APs "
         "automatically");


static struct sta_info* ap_get_sta(struct ap_data *ap, u8 *sta);
static void hostap_event_expired_sta(struct net_device *dev,
                     struct sta_info *sta);
static void handle_add_proc_queue(struct work_struct *work);

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
static void handle_wds_oper_queue(struct work_struct *work);
static void prism2_send_mgmt(struct net_device *dev,
                 u16 type_subtype, char *body,
                 int body_len, u8 *addr, u16 tx_cb_idx);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


#ifndef PRISM2_NO_PROCFS_DEBUG
static int ap_debug_proc_read(char *page, char **start, off_t off,
                  int count, int *eof, void *data)
{
    char *p = page;
    struct ap_data *ap = (struct ap_data *) data;

    if (off != 0) {
        *eof = 1;
        return 0;
    }

    p += sprintf(p, "BridgedUnicastFrames=%u\n", ap->bridged_unicast);
    p += sprintf(p, "BridgedMulticastFrames=%u\n", ap->bridged_multicast);
    p += sprintf(p, "max_inactivity=%u\n", ap->max_inactivity / HZ);
    p += sprintf(p, "bridge_packets=%u\n", ap->bridge_packets);
    p += sprintf(p, "nullfunc_ack=%u\n", ap->nullfunc_ack);
    p += sprintf(p, "autom_ap_wds=%u\n", ap->autom_ap_wds);
    p += sprintf(p, "auth_algs=%u\n", ap->local->auth_algs);
    p += sprintf(p, "tx_drop_nonassoc=%u\n", ap->tx_drop_nonassoc);

    return (p - page);
}
#endif /* PRISM2_NO_PROCFS_DEBUG */


static void ap_sta_hash_add(struct ap_data *ap, struct sta_info *sta)
{
    sta->hnext = ap->sta_hash[STA_HASH(sta->addr)];
    ap->sta_hash[STA_HASH(sta->addr)] = sta;
}

static void ap_sta_hash_del(struct ap_data *ap, struct sta_info *sta)
{
    struct sta_info *s;

    s = ap->sta_hash[STA_HASH(sta->addr)];
    if (s == NULL) return;
    if (memcmp(s->addr, sta->addr, ETH_ALEN) == 0) {
        ap->sta_hash[STA_HASH(sta->addr)] = s->hnext;
        return;
    }

    while (s->hnext != NULL && memcmp(s->hnext->addr, sta->addr, ETH_ALEN)
           != 0)
        s = s->hnext;
    if (s->hnext != NULL)
        s->hnext = s->hnext->hnext;
    else
        printk("AP: could not remove STA %pM from hash table\n",
               sta->addr);
}

static void ap_free_sta(struct ap_data *ap, struct sta_info *sta)
{
    if (sta->ap && sta->local)
        hostap_event_expired_sta(sta->local->dev, sta);

    if (ap->proc != NULL) {
        char name[20];
        sprintf(name, "%pM", sta->addr);
        remove_proc_entry(name, ap->proc);
    }

    if (sta->crypt) {
        sta->crypt->ops->deinit(sta->crypt->priv);
        kfree(sta->crypt);
        sta->crypt = NULL;
    }

    skb_queue_purge(&sta->tx_buf);

    ap->num_sta--;
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    if (sta->aid > 0)
        ap->sta_aid[sta->aid - 1] = NULL;

    if (!sta->ap && sta->u.sta.challenge)
        kfree(sta->u.sta.challenge);
    del_timer(&sta->timer);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    kfree(sta);
}


static void hostap_set_tim(local_info_t *local, int aid, int set)
{
    if (local->func->set_tim)
        local->func->set_tim(local->dev, aid, set);
}


static void hostap_event_new_sta(struct net_device *dev, struct sta_info *sta)
{
    union iwreq_data wrqu;
    memset(&wrqu, 0, sizeof(wrqu));
    memcpy(wrqu.addr.sa_data, sta->addr, ETH_ALEN);
    wrqu.addr.sa_family = ARPHRD_ETHER;
    wireless_send_event(dev, IWEVREGISTERED, &wrqu, NULL);
}


static void hostap_event_expired_sta(struct net_device *dev,
                     struct sta_info *sta)
{
    union iwreq_data wrqu;
    memset(&wrqu, 0, sizeof(wrqu));
    memcpy(wrqu.addr.sa_data, sta->addr, ETH_ALEN);
    wrqu.addr.sa_family = ARPHRD_ETHER;
    wireless_send_event(dev, IWEVEXPIRED, &wrqu, NULL);
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT

static void ap_handle_timer(unsigned long data)
{
    struct sta_info *sta = (struct sta_info *) data;
    local_info_t *local;
    struct ap_data *ap;
    unsigned long next_time = 0;
    int was_assoc;

    if (sta == NULL || sta->local == NULL || sta->local->ap == NULL) {
        PDEBUG(DEBUG_AP, "ap_handle_timer() called with NULL data\n");
        return;
    }

    local = sta->local;
    ap = local->ap;
    was_assoc = sta->flags & WLAN_STA_ASSOC;

    if (atomic_read(&sta->users) != 0)
        next_time = jiffies + HZ;
    else if ((sta->flags & WLAN_STA_PERM) && !(sta->flags & WLAN_STA_AUTH))
        next_time = jiffies + ap->max_inactivity;

    if (time_before(jiffies, sta->last_rx + ap->max_inactivity)) {
        /* station activity detected; reset timeout state */
        sta->timeout_next = STA_NULLFUNC;
        next_time = sta->last_rx + ap->max_inactivity;
    } else if (sta->timeout_next == STA_DISASSOC &&
           !(sta->flags & WLAN_STA_PENDING_POLL)) {
        /* STA ACKed data nullfunc frame poll */
        sta->timeout_next = STA_NULLFUNC;
        next_time = jiffies + ap->max_inactivity;
    }

    if (next_time) {
        sta->timer.expires = next_time;
        add_timer(&sta->timer);
        return;
    }

    if (sta->ap)
        sta->timeout_next = STA_DEAUTH;

    if (sta->timeout_next == STA_DEAUTH && !(sta->flags & WLAN_STA_PERM)) {
        spin_lock(&ap->sta_table_lock);
        ap_sta_hash_del(ap, sta);
        list_del(&sta->list);
        spin_unlock(&ap->sta_table_lock);
        sta->flags &= ~(WLAN_STA_AUTH | WLAN_STA_ASSOC);
    } else if (sta->timeout_next == STA_DISASSOC)
        sta->flags &= ~WLAN_STA_ASSOC;

    if (was_assoc && !(sta->flags & WLAN_STA_ASSOC) && !sta->ap)
        hostap_event_expired_sta(local->dev, sta);

    if (sta->timeout_next == STA_DEAUTH && sta->aid > 0 &&
        !skb_queue_empty(&sta->tx_buf)) {
        hostap_set_tim(local, sta->aid, 0);
        sta->flags &= ~WLAN_STA_TIM;
    }

    if (sta->ap) {
        if (ap->autom_ap_wds) {
            PDEBUG(DEBUG_AP, "%s: removing automatic WDS "
                   "connection to AP %pM\n",
                   local->dev->name, sta->addr);
            hostap_wds_link_oper(local, sta->addr, WDS_DEL);
        }
    } else if (sta->timeout_next == STA_NULLFUNC) {
        /* send data frame to poll STA and check whether this frame
         * is ACKed */
        /* FIX: IEEE80211_STYPE_NULLFUNC would be more appropriate, but
         * it is apparently not retried so TX Exc events are not
         * received for it */
        sta->flags |= WLAN_STA_PENDING_POLL;
        prism2_send_mgmt(local->dev, IEEE80211_FTYPE_DATA |
                 IEEE80211_STYPE_DATA, NULL, 0,
                 sta->addr, ap->tx_callback_poll);
    } else {
        int deauth = sta->timeout_next == STA_DEAUTH;
        __le16 resp;
        PDEBUG(DEBUG_AP, "%s: sending %s info to STA %pM"
               "(last=%lu, jiffies=%lu)\n",
               local->dev->name,
               deauth ? "deauthentication" : "disassociation",
               sta->addr, sta->last_rx, jiffies);

        resp = cpu_to_le16(deauth ? WLAN_REASON_PREV_AUTH_NOT_VALID :
                   WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY);
        prism2_send_mgmt(local->dev, IEEE80211_FTYPE_MGMT |
                 (deauth ? IEEE80211_STYPE_DEAUTH :
                  IEEE80211_STYPE_DISASSOC),
                 (char *) &resp, 2, sta->addr, 0);
    }

    if (sta->timeout_next == STA_DEAUTH) {
        if (sta->flags & WLAN_STA_PERM) {
            PDEBUG(DEBUG_AP, "%s: STA %pM"
                   " would have been removed, "
                   "but it has 'perm' flag\n",
                   local->dev->name, sta->addr);
        } else
            ap_free_sta(ap, sta);
        return;
    }

    if (sta->timeout_next == STA_NULLFUNC) {
        sta->timeout_next = STA_DISASSOC;
        sta->timer.expires = jiffies + AP_DISASSOC_DELAY;
    } else {
        sta->timeout_next = STA_DEAUTH;
        sta->timer.expires = jiffies + AP_DEAUTH_DELAY;
    }

    add_timer(&sta->timer);
}


void hostap_deauth_all_stas(struct net_device *dev, struct ap_data *ap,
                int resend)
{
    u8 addr[ETH_ALEN];
    __le16 resp;
    int i;

    PDEBUG(DEBUG_AP, "%s: Deauthenticate all stations\n", dev->name);
    memset(addr, 0xff, ETH_ALEN);

    resp = cpu_to_le16(WLAN_REASON_PREV_AUTH_NOT_VALID);

    /* deauth message sent; try to resend it few times; the message is
     * broadcast, so it may be delayed until next DTIM; there is not much
     * else we can do at this point since the driver is going to be shut
     * down */
    for (i = 0; i < 5; i++) {
        prism2_send_mgmt(dev, IEEE80211_FTYPE_MGMT |
                 IEEE80211_STYPE_DEAUTH,
                 (char *) &resp, 2, addr, 0);

        if (!resend || ap->num_sta <= 0)
            return;

        mdelay(50);
    }
}


static int ap_control_proc_read(char *page, char **start, off_t off,
                int count, int *eof, void *data)
{
    char *p = page;
    struct ap_data *ap = (struct ap_data *) data;
    char *policy_txt;
    struct mac_entry *entry;

    if (off != 0) {
        *eof = 1;
        return 0;
    }

    switch (ap->mac_restrictions.policy) {
    case MAC_POLICY_OPEN:
        policy_txt = "open";
        break;
    case MAC_POLICY_ALLOW:
        policy_txt = "allow";
        break;
    case MAC_POLICY_DENY:
        policy_txt = "deny";
        break;
    default:
        policy_txt = "unknown";
        break;
    }
    p += sprintf(p, "MAC policy: %s\n", policy_txt);
    p += sprintf(p, "MAC entries: %u\n", ap->mac_restrictions.entries);
    p += sprintf(p, "MAC list:\n");
    spin_lock_bh(&ap->mac_restrictions.lock);
    list_for_each_entry(entry, &ap->mac_restrictions.mac_list, list) {
        if (p - page > PAGE_SIZE - 80) {
            p += sprintf(p, "All entries did not fit one page.\n");
            break;
        }

        p += sprintf(p, "%pM\n", entry->addr);
    }
    spin_unlock_bh(&ap->mac_restrictions.lock);

    return (p - page);
}


int ap_control_add_mac(struct mac_restrictions *mac_restrictions, u8 *mac)
{
    struct mac_entry *entry;

    entry = kmalloc(sizeof(struct mac_entry), GFP_KERNEL);
    if (entry == NULL)
        return -1;

    memcpy(entry->addr, mac, ETH_ALEN);

    spin_lock_bh(&mac_restrictions->lock);
    list_add_tail(&entry->list, &mac_restrictions->mac_list);
    mac_restrictions->entries++;
    spin_unlock_bh(&mac_restrictions->lock);

    return 0;
}


int ap_control_del_mac(struct mac_restrictions *mac_restrictions, u8 *mac)
{
    struct list_head *ptr;
    struct mac_entry *entry;

    spin_lock_bh(&mac_restrictions->lock);
    for (ptr = mac_restrictions->mac_list.next;
         ptr != &mac_restrictions->mac_list; ptr = ptr->next) {
        entry = list_entry(ptr, struct mac_entry, list);

        if (memcmp(entry->addr, mac, ETH_ALEN) == 0) {
            list_del(ptr);
            kfree(entry);
            mac_restrictions->entries--;
            spin_unlock_bh(&mac_restrictions->lock);
            return 0;
        }
    }
    spin_unlock_bh(&mac_restrictions->lock);
    return -1;
}


static int ap_control_mac_deny(struct mac_restrictions *mac_restrictions,
                   u8 *mac)
{
    struct mac_entry *entry;
    int found = 0;

    if (mac_restrictions->policy == MAC_POLICY_OPEN)
        return 0;

    spin_lock_bh(&mac_restrictions->lock);
    list_for_each_entry(entry, &mac_restrictions->mac_list, list) {
        if (memcmp(entry->addr, mac, ETH_ALEN) == 0) {
            found = 1;
            break;
        }
    }
    spin_unlock_bh(&mac_restrictions->lock);

    if (mac_restrictions->policy == MAC_POLICY_ALLOW)
        return !found;
    else
        return found;
}


void ap_control_flush_macs(struct mac_restrictions *mac_restrictions)
{
    struct list_head *ptr, *n;
    struct mac_entry *entry;

    if (mac_restrictions->entries == 0)
        return;

    spin_lock_bh(&mac_restrictions->lock);
    for (ptr = mac_restrictions->mac_list.next, n = ptr->next;
         ptr != &mac_restrictions->mac_list;
         ptr = n, n = ptr->next) {
        entry = list_entry(ptr, struct mac_entry, list);
        list_del(ptr);
        kfree(entry);
    }
    mac_restrictions->entries = 0;
    spin_unlock_bh(&mac_restrictions->lock);
}


int ap_control_kick_mac(struct ap_data *ap, struct net_device *dev, u8 *mac)
{
    struct sta_info *sta;
    __le16 resp;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, mac);
    if (sta) {
        ap_sta_hash_del(ap, sta);
        list_del(&sta->list);
    }
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta)
        return -EINVAL;

    resp = cpu_to_le16(WLAN_REASON_PREV_AUTH_NOT_VALID);
    prism2_send_mgmt(dev, IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_DEAUTH,
             (char *) &resp, 2, sta->addr, 0);

    if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap)
        hostap_event_expired_sta(dev, sta);

    ap_free_sta(ap, sta);

    return 0;
}

#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


void ap_control_kickall(struct ap_data *ap)
{
    struct list_head *ptr, *n;
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    for (ptr = ap->sta_list.next, n = ptr->next; ptr != &ap->sta_list;
         ptr = n, n = ptr->next) {
        sta = list_entry(ptr, struct sta_info, list);
        ap_sta_hash_del(ap, sta);
        list_del(&sta->list);
        if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap && sta->local)
            hostap_event_expired_sta(sta->local->dev, sta);
        ap_free_sta(ap, sta);
    }
    spin_unlock_bh(&ap->sta_table_lock);
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT

#define PROC_LIMIT (PAGE_SIZE - 80)

static int prism2_ap_proc_read(char *page, char **start, off_t off,
                   int count, int *eof, void *data)
{
    char *p = page;
    struct ap_data *ap = (struct ap_data *) data;
    struct sta_info *sta;
    int i;

    if (off > PROC_LIMIT) {
        *eof = 1;
        return 0;
    }

    p += sprintf(p, "# BSSID CHAN SIGNAL NOISE RATE SSID FLAGS\n");
    spin_lock_bh(&ap->sta_table_lock);
    list_for_each_entry(sta, &ap->sta_list, list) {
        if (!sta->ap)
            continue;

        p += sprintf(p, "%pM %d %d %d %d '",
                 sta->addr,
                 sta->u.ap.channel, sta->last_rx_signal,
                 sta->last_rx_silence, sta->last_rx_rate);
        for (i = 0; i < sta->u.ap.ssid_len; i++)
            p += sprintf(p, ((sta->u.ap.ssid[i] >= 32 &&
                      sta->u.ap.ssid[i] < 127) ?
                     "%c" : "<%02x>"),
                     sta->u.ap.ssid[i]);
        p += sprintf(p, "'");
        if (sta->capability & WLAN_CAPABILITY_ESS)
            p += sprintf(p, " [ESS]");
        if (sta->capability & WLAN_CAPABILITY_IBSS)
            p += sprintf(p, " [IBSS]");
        if (sta->capability & WLAN_CAPABILITY_PRIVACY)
            p += sprintf(p, " [WEP]");
        p += sprintf(p, "\n");

        if ((p - page) > PROC_LIMIT) {
            printk(KERN_DEBUG "hostap: ap proc did not fit\n");
            break;
        }
    }
    spin_unlock_bh(&ap->sta_table_lock);

    if ((p - page) <= off) {
        *eof = 1;
        return 0;
    }

    *start = page + off;

    return (p - page - off);
}
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


void hostap_check_sta_fw_version(struct ap_data *ap, int sta_fw_ver)
{
    if (!ap)
        return;

    if (sta_fw_ver == PRISM2_FW_VER(0,8,0)) {
        PDEBUG(DEBUG_AP, "Using data::nullfunc ACK workaround - "
               "firmware upgrade recommended\n");
        ap->nullfunc_ack = 1;
    } else
        ap->nullfunc_ack = 0;

    if (sta_fw_ver == PRISM2_FW_VER(1,4,2)) {
        printk(KERN_WARNING "%s: Warning: secondary station firmware "
               "version 1.4.2 does not seem to work in Host AP mode\n",
               ap->local->dev->name);
    }
}


/* Called only as a tasklet (software IRQ) */
static void hostap_ap_tx_cb(struct sk_buff *skb, int ok, void *data)
{
    struct ap_data *ap = data;
    struct ieee80211_hdr *hdr;

    if (!ap->local->hostapd || !ap->local->apdev) {
        dev_kfree_skb(skb);
        return;
    }

    /* Pass the TX callback frame to the hostapd; use 802.11 header version
     * 1 to indicate failure (no ACK) and 2 success (frame ACKed) */

    hdr = (struct ieee80211_hdr *) skb->data;
    hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_VERS);
    hdr->frame_control |= cpu_to_le16(ok ? BIT(1) : BIT(0));

    skb->dev = ap->local->apdev;
    skb_pull(skb, hostap_80211_get_hdrlen(hdr->frame_control));
    skb->pkt_type = PACKET_OTHERHOST;
    skb->protocol = cpu_to_be16(ETH_P_802_2);
    memset(skb->cb, 0, sizeof(skb->cb));
    netif_rx(skb);
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
/* Called only as a tasklet (software IRQ) */
static void hostap_ap_tx_cb_auth(struct sk_buff *skb, int ok, void *data)
{
    struct ap_data *ap = data;
    struct net_device *dev = ap->local->dev;
    struct ieee80211_hdr *hdr;
    u16 auth_alg, auth_transaction, status;
    __le16 *pos;
    struct sta_info *sta = NULL;
    char *txt = NULL;

    if (ap->local->hostapd) {
        dev_kfree_skb(skb);
        return;
    }

    hdr = (struct ieee80211_hdr *) skb->data;
    if (!ieee80211_is_auth(hdr->frame_control) ||
        skb->len < IEEE80211_MGMT_HDR_LEN + 6) {
        printk(KERN_DEBUG "%s: hostap_ap_tx_cb_auth received invalid "
               "frame\n", dev->name);
        dev_kfree_skb(skb);
        return;
    }

    pos = (__le16 *) (skb->data + IEEE80211_MGMT_HDR_LEN);
    auth_alg = le16_to_cpu(*pos++);
    auth_transaction = le16_to_cpu(*pos++);
    status = le16_to_cpu(*pos++);

    if (!ok) {
        txt = "frame was not ACKed";
        goto done;
    }

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, hdr->addr1);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&ap->sta_table_lock);

    if (!sta) {
        txt = "STA not found";
        goto done;
    }

    if (status == WLAN_STATUS_SUCCESS &&
        ((auth_alg == WLAN_AUTH_OPEN && auth_transaction == 2) ||
         (auth_alg == WLAN_AUTH_SHARED_KEY && auth_transaction == 4))) {
        txt = "STA authenticated";
        sta->flags |= WLAN_STA_AUTH;
        sta->last_auth = jiffies;
    } else if (status != WLAN_STATUS_SUCCESS)
        txt = "authentication failed";

 done:
    if (sta)
        atomic_dec(&sta->users);
    if (txt) {
        PDEBUG(DEBUG_AP, "%s: %pM auth_cb - alg=%d "
               "trans#=%d status=%d - %s\n",
               dev->name, hdr->addr1,
               auth_alg, auth_transaction, status, txt);
    }
    dev_kfree_skb(skb);
}


/* Called only as a tasklet (software IRQ) */
static void hostap_ap_tx_cb_assoc(struct sk_buff *skb, int ok, void *data)
{
    struct ap_data *ap = data;
    struct net_device *dev = ap->local->dev;
    struct ieee80211_hdr *hdr;
    u16 status;
    __le16 *pos;
    struct sta_info *sta = NULL;
    char *txt = NULL;

    if (ap->local->hostapd) {
        dev_kfree_skb(skb);
        return;
    }

    hdr = (struct ieee80211_hdr *) skb->data;
    if ((!ieee80211_is_assoc_resp(hdr->frame_control) &&
         !ieee80211_is_reassoc_resp(hdr->frame_control)) ||
        skb->len < IEEE80211_MGMT_HDR_LEN + 4) {
        printk(KERN_DEBUG "%s: hostap_ap_tx_cb_assoc received invalid "
               "frame\n", dev->name);
        dev_kfree_skb(skb);
        return;
    }

    if (!ok) {
        txt = "frame was not ACKed";
        goto done;
    }

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, hdr->addr1);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&ap->sta_table_lock);

    if (!sta) {
        txt = "STA not found";
        goto done;
    }

    pos = (__le16 *) (skb->data + IEEE80211_MGMT_HDR_LEN);
    pos++;
    status = le16_to_cpu(*pos++);
    if (status == WLAN_STATUS_SUCCESS) {
        if (!(sta->flags & WLAN_STA_ASSOC))
            hostap_event_new_sta(dev, sta);
        txt = "STA associated";
        sta->flags |= WLAN_STA_ASSOC;
        sta->last_assoc = jiffies;
    } else
        txt = "association failed";

 done:
    if (sta)
        atomic_dec(&sta->users);
    if (txt) {
        PDEBUG(DEBUG_AP, "%s: %pM assoc_cb - %s\n",
               dev->name, hdr->addr1, txt);
    }
    dev_kfree_skb(skb);
}

/* Called only as a tasklet (software IRQ); TX callback for poll frames used
 * in verifying whether the STA is still present. */
static void hostap_ap_tx_cb_poll(struct sk_buff *skb, int ok, void *data)
{
    struct ap_data *ap = data;
    struct ieee80211_hdr *hdr;
    struct sta_info *sta;

    if (skb->len < 24)
        goto fail;
    hdr = (struct ieee80211_hdr *) skb->data;
    if (ok) {
        spin_lock(&ap->sta_table_lock);
        sta = ap_get_sta(ap, hdr->addr1);
        if (sta)
            sta->flags &= ~WLAN_STA_PENDING_POLL;
        spin_unlock(&ap->sta_table_lock);
    } else {
        PDEBUG(DEBUG_AP,
               "%s: STA %pM did not ACK activity poll frame\n",
               ap->local->dev->name, hdr->addr1);
    }

 fail:
    dev_kfree_skb(skb);
}
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


void hostap_init_data(local_info_t *local)
{
    struct ap_data *ap = local->ap;

    if (ap == NULL) {
        printk(KERN_WARNING "hostap_init_data: ap == NULL\n");
        return;
    }
    memset(ap, 0, sizeof(struct ap_data));
    ap->local = local;

    ap->ap_policy = GET_INT_PARM(other_ap_policy, local->card_idx);
    ap->bridge_packets = GET_INT_PARM(ap_bridge_packets, local->card_idx);
    ap->max_inactivity =
        GET_INT_PARM(ap_max_inactivity, local->card_idx) * HZ;
    ap->autom_ap_wds = GET_INT_PARM(autom_ap_wds, local->card_idx);

    spin_lock_init(&ap->sta_table_lock);
    INIT_LIST_HEAD(&ap->sta_list);

    /* Initialize task queue structure for AP management */
    INIT_WORK(&local->ap->add_sta_proc_queue, handle_add_proc_queue);

    ap->tx_callback_idx =
        hostap_tx_callback_register(local, hostap_ap_tx_cb, ap);
    if (ap->tx_callback_idx == 0)
        printk(KERN_WARNING "%s: failed to register TX callback for "
               "AP\n", local->dev->name);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    INIT_WORK(&local->ap->wds_oper_queue, handle_wds_oper_queue);

    ap->tx_callback_auth =
        hostap_tx_callback_register(local, hostap_ap_tx_cb_auth, ap);
    ap->tx_callback_assoc =
        hostap_tx_callback_register(local, hostap_ap_tx_cb_assoc, ap);
    ap->tx_callback_poll =
        hostap_tx_callback_register(local, hostap_ap_tx_cb_poll, ap);
    if (ap->tx_callback_auth == 0 || ap->tx_callback_assoc == 0 ||
        ap->tx_callback_poll == 0)
        printk(KERN_WARNING "%s: failed to register TX callback for "
               "AP\n", local->dev->name);

    spin_lock_init(&ap->mac_restrictions.lock);
    INIT_LIST_HEAD(&ap->mac_restrictions.mac_list);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    ap->initialized = 1;
}


void hostap_init_ap_proc(local_info_t *local)
{
    struct ap_data *ap = local->ap;

    ap->proc = local->proc;
    if (ap->proc == NULL)
        return;

#ifndef PRISM2_NO_PROCFS_DEBUG
    create_proc_read_entry("ap_debug", 0, ap->proc,
                   ap_debug_proc_read, ap);
#endif /* PRISM2_NO_PROCFS_DEBUG */

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    create_proc_read_entry("ap_control", 0, ap->proc,
                   ap_control_proc_read, ap);
    create_proc_read_entry("ap", 0, ap->proc,
                   prism2_ap_proc_read, ap);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

}


void hostap_free_data(struct ap_data *ap)
{
    struct sta_info *n, *sta;

    if (ap == NULL || !ap->initialized) {
        printk(KERN_DEBUG "hostap_free_data: ap has not yet been "
               "initialized - skip resource freeing\n");
        return;
    }

    flush_work(&ap->add_sta_proc_queue);

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    flush_work(&ap->wds_oper_queue);
    if (ap->crypt)
        ap->crypt->deinit(ap->crypt_priv);
    ap->crypt = ap->crypt_priv = NULL;
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    list_for_each_entry_safe(sta, n, &ap->sta_list, list) {
        ap_sta_hash_del(ap, sta);
        list_del(&sta->list);
        if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap && sta->local)
            hostap_event_expired_sta(sta->local->dev, sta);
        ap_free_sta(ap, sta);
    }

#ifndef PRISM2_NO_PROCFS_DEBUG
    if (ap->proc != NULL) {
        remove_proc_entry("ap_debug", ap->proc);
    }
#endif /* PRISM2_NO_PROCFS_DEBUG */

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    if (ap->proc != NULL) {
      remove_proc_entry("ap", ap->proc);
        remove_proc_entry("ap_control", ap->proc);
    }
    ap_control_flush_macs(&ap->mac_restrictions);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    ap->initialized = 0;
}


/* caller should have mutex for AP STA list handling */
static struct sta_info* ap_get_sta(struct ap_data *ap, u8 *sta)
{
    struct sta_info *s;

    s = ap->sta_hash[STA_HASH(sta)];
    while (s != NULL && memcmp(s->addr, sta, ETH_ALEN) != 0)
        s = s->hnext;
    return s;
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT

/* Called from timer handler and from scheduled AP queue handlers */
static void prism2_send_mgmt(struct net_device *dev,
                 u16 type_subtype, char *body,
                 int body_len, u8 *addr, u16 tx_cb_idx)
{
    struct hostap_interface *iface;
    local_info_t *local;
    struct ieee80211_hdr *hdr;
    u16 fc;
    struct sk_buff *skb;
    struct hostap_skb_tx_data *meta;
    int hdrlen;

    iface = netdev_priv(dev);
    local = iface->local;
    dev = local->dev; /* always use master radio device */
    iface = netdev_priv(dev);

    if (!(dev->flags & IFF_UP)) {
        PDEBUG(DEBUG_AP, "%s: prism2_send_mgmt - device is not UP - "
               "cannot send frame\n", dev->name);
        return;
    }

    skb = dev_alloc_skb(sizeof(*hdr) + body_len);
    if (skb == NULL) {
        PDEBUG(DEBUG_AP, "%s: prism2_send_mgmt failed to allocate "
               "skb\n", dev->name);
        return;
    }

    fc = type_subtype;
    hdrlen = hostap_80211_get_hdrlen(cpu_to_le16(type_subtype));
    hdr = (struct ieee80211_hdr *) skb_put(skb, hdrlen);
    if (body)
        memcpy(skb_put(skb, body_len), body, body_len);

    memset(hdr, 0, hdrlen);

    /* FIX: ctrl::ack sending used special HFA384X_TX_CTRL_802_11
     * tx_control instead of using local->tx_control */


    memcpy(hdr->addr1, addr, ETH_ALEN); /* DA / RA */
    if (ieee80211_is_data(hdr->frame_control)) {
        fc |= IEEE80211_FCTL_FROMDS;
        memcpy(hdr->addr2, dev->dev_addr, ETH_ALEN); /* BSSID */
        memcpy(hdr->addr3, dev->dev_addr, ETH_ALEN); /* SA */
    } else if (ieee80211_is_ctl(hdr->frame_control)) {
        /* control:ACK does not have addr2 or addr3 */
        memset(hdr->addr2, 0, ETH_ALEN);
        memset(hdr->addr3, 0, ETH_ALEN);
    } else {
        memcpy(hdr->addr2, dev->dev_addr, ETH_ALEN); /* SA */
        memcpy(hdr->addr3, dev->dev_addr, ETH_ALEN); /* BSSID */
    }

    hdr->frame_control = cpu_to_le16(fc);

    meta = (struct hostap_skb_tx_data *) skb->cb;
    memset(meta, 0, sizeof(*meta));
    meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
    meta->iface = iface;
    meta->tx_cb_idx = tx_cb_idx;

    skb->dev = dev;
    skb_reset_mac_header(skb);
    skb_reset_network_header(skb);
    dev_queue_xmit(skb);
}
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


static int prism2_sta_proc_read(char *page, char **start, off_t off,
                int count, int *eof, void *data)
{
    char *p = page;
    struct sta_info *sta = (struct sta_info *) data;
    int i;

    /* FIX: possible race condition.. the STA data could have just expired,
     * but proc entry was still here so that the read could have started;
     * some locking should be done here.. */

    if (off != 0) {
        *eof = 1;
        return 0;
    }

    p += sprintf(p, "%s=%pM\nusers=%d\naid=%d\n"
             "flags=0x%04x%s%s%s%s%s%s%s\n"
             "capability=0x%02x\nlisten_interval=%d\nsupported_rates=",
             sta->ap ? "AP" : "STA",
             sta->addr, atomic_read(&sta->users), sta->aid,
             sta->flags,
             sta->flags & WLAN_STA_AUTH ? " AUTH" : "",
             sta->flags & WLAN_STA_ASSOC ? " ASSOC" : "",
             sta->flags & WLAN_STA_PS ? " PS" : "",
             sta->flags & WLAN_STA_TIM ? " TIM" : "",
             sta->flags & WLAN_STA_PERM ? " PERM" : "",
             sta->flags & WLAN_STA_AUTHORIZED ? " AUTHORIZED" : "",
             sta->flags & WLAN_STA_PENDING_POLL ? " POLL" : "",
             sta->capability, sta->listen_interval);
    /* supported_rates: 500 kbit/s units with msb ignored */
    for (i = 0; i < sizeof(sta->supported_rates); i++)
        if (sta->supported_rates[i] != 0)
            p += sprintf(p, "%d%sMbps ",
                     (sta->supported_rates[i] & 0x7f) / 2,
                     sta->supported_rates[i] & 1 ? ".5" : "");
    p += sprintf(p, "\njiffies=%lu\nlast_auth=%lu\nlast_assoc=%lu\n"
             "last_rx=%lu\nlast_tx=%lu\nrx_packets=%lu\n"
             "tx_packets=%lu\n"
             "rx_bytes=%lu\ntx_bytes=%lu\nbuffer_count=%d\n"
             "last_rx: silence=%d dBm signal=%d dBm rate=%d%s Mbps\n"
             "tx_rate=%d\ntx[1M]=%d\ntx[2M]=%d\ntx[5.5M]=%d\n"
             "tx[11M]=%d\n"
             "rx[1M]=%d\nrx[2M]=%d\nrx[5.5M]=%d\nrx[11M]=%d\n",
             jiffies, sta->last_auth, sta->last_assoc, sta->last_rx,
             sta->last_tx,
             sta->rx_packets, sta->tx_packets, sta->rx_bytes,
             sta->tx_bytes, skb_queue_len(&sta->tx_buf),
             sta->last_rx_silence,
             sta->last_rx_signal, sta->last_rx_rate / 10,
             sta->last_rx_rate % 10 ? ".5" : "",
             sta->tx_rate, sta->tx_count[0], sta->tx_count[1],
             sta->tx_count[2], sta->tx_count[3],  sta->rx_count[0],
             sta->rx_count[1], sta->rx_count[2], sta->rx_count[3]);
    if (sta->crypt && sta->crypt->ops && sta->crypt->ops->print_stats)
        p = sta->crypt->ops->print_stats(p, sta->crypt->priv);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    if (sta->ap) {
        if (sta->u.ap.channel >= 0)
            p += sprintf(p, "channel=%d\n", sta->u.ap.channel);
        p += sprintf(p, "ssid=");
        for (i = 0; i < sta->u.ap.ssid_len; i++)
            p += sprintf(p, ((sta->u.ap.ssid[i] >= 32 &&
                      sta->u.ap.ssid[i] < 127) ?
                     "%c" : "<%02x>"),
                     sta->u.ap.ssid[i]);
        p += sprintf(p, "\n");
    }
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    return (p - page);
}


static void handle_add_proc_queue(struct work_struct *work)
{
    struct ap_data *ap = container_of(work, struct ap_data,
                      add_sta_proc_queue);
    struct sta_info *sta;
    char name[20];
    struct add_sta_proc_data *entry, *prev;

    entry = ap->add_sta_proc_entries;
    ap->add_sta_proc_entries = NULL;

    while (entry) {
        spin_lock_bh(&ap->sta_table_lock);
        sta = ap_get_sta(ap, entry->addr);
        if (sta)
            atomic_inc(&sta->users);
        spin_unlock_bh(&ap->sta_table_lock);

        if (sta) {
            sprintf(name, "%pM", sta->addr);
            sta->proc = create_proc_read_entry(
                name, 0, ap->proc,
                prism2_sta_proc_read, sta);

            atomic_dec(&sta->users);
        }

        prev = entry;
        entry = entry->next;
        kfree(prev);
    }
}


static struct sta_info * ap_add_sta(struct ap_data *ap, u8 *addr)
{
    struct sta_info *sta;

    sta = kzalloc(sizeof(struct sta_info), GFP_ATOMIC);
    if (sta == NULL) {
        PDEBUG(DEBUG_AP, "AP: kmalloc failed\n");
        return NULL;
    }

    /* initialize STA info data */
    sta->local = ap->local;
    skb_queue_head_init(&sta->tx_buf);
    memcpy(sta->addr, addr, ETH_ALEN);

    atomic_inc(&sta->users);
    spin_lock_bh(&ap->sta_table_lock);
    list_add(&sta->list, &ap->sta_list);
    ap->num_sta++;
    ap_sta_hash_add(ap, sta);
    spin_unlock_bh(&ap->sta_table_lock);

    if (ap->proc) {
        struct add_sta_proc_data *entry;
        /* schedule a non-interrupt context process to add a procfs
         * entry for the STA since procfs code use GFP_KERNEL */
        entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
        if (entry) {
            memcpy(entry->addr, sta->addr, ETH_ALEN);
            entry->next = ap->add_sta_proc_entries;
            ap->add_sta_proc_entries = entry;
            schedule_work(&ap->add_sta_proc_queue);
        } else
            printk(KERN_DEBUG "Failed to add STA proc data\n");
    }

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    init_timer(&sta->timer);
    sta->timer.expires = jiffies + ap->max_inactivity;
    sta->timer.data = (unsigned long) sta;
    sta->timer.function = ap_handle_timer;
    if (!ap->local->hostapd)
        add_timer(&sta->timer);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    return sta;
}


static int ap_tx_rate_ok(int rateidx, struct sta_info *sta,
             local_info_t *local)
{
    if (rateidx > sta->tx_max_rate ||
        !(sta->tx_supp_rates & (1 << rateidx)))
        return 0;

    if (local->tx_rate_control != 0 &&
        !(local->tx_rate_control & (1 << rateidx)))
        return 0;

    return 1;
}


static void prism2_check_tx_rates(struct sta_info *sta)
{
    int i;

    sta->tx_supp_rates = 0;
    for (i = 0; i < sizeof(sta->supported_rates); i++) {
        if ((sta->supported_rates[i] & 0x7f) == 2)
            sta->tx_supp_rates |= WLAN_RATE_1M;
        if ((sta->supported_rates[i] & 0x7f) == 4)
            sta->tx_supp_rates |= WLAN_RATE_2M;
        if ((sta->supported_rates[i] & 0x7f) == 11)
            sta->tx_supp_rates |= WLAN_RATE_5M5;
        if ((sta->supported_rates[i] & 0x7f) == 22)
            sta->tx_supp_rates |= WLAN_RATE_11M;
    }
    sta->tx_max_rate = sta->tx_rate = sta->tx_rate_idx = 0;
    if (sta->tx_supp_rates & WLAN_RATE_1M) {
        sta->tx_max_rate = 0;
        if (ap_tx_rate_ok(0, sta, sta->local)) {
            sta->tx_rate = 10;
            sta->tx_rate_idx = 0;
        }
    }
    if (sta->tx_supp_rates & WLAN_RATE_2M) {
        sta->tx_max_rate = 1;
        if (ap_tx_rate_ok(1, sta, sta->local)) {
            sta->tx_rate = 20;
            sta->tx_rate_idx = 1;
        }
    }
    if (sta->tx_supp_rates & WLAN_RATE_5M5) {
        sta->tx_max_rate = 2;
        if (ap_tx_rate_ok(2, sta, sta->local)) {
            sta->tx_rate = 55;
            sta->tx_rate_idx = 2;
        }
    }
    if (sta->tx_supp_rates & WLAN_RATE_11M) {
        sta->tx_max_rate = 3;
        if (ap_tx_rate_ok(3, sta, sta->local)) {
            sta->tx_rate = 110;
            sta->tx_rate_idx = 3;
        }
    }
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT

static void ap_crypt_init(struct ap_data *ap)
{
    ap->crypt = lib80211_get_crypto_ops("WEP");

    if (ap->crypt) {
        if (ap->crypt->init) {
            ap->crypt_priv = ap->crypt->init(0);
            if (ap->crypt_priv == NULL)
                ap->crypt = NULL;
            else {
                u8 key[WEP_KEY_LEN];
                get_random_bytes(key, WEP_KEY_LEN);
                ap->crypt->set_key(key, WEP_KEY_LEN, NULL,
                           ap->crypt_priv);
            }
        }
    }

    if (ap->crypt == NULL) {
        printk(KERN_WARNING "AP could not initialize WEP: load module "
               "lib80211_crypt_wep.ko\n");
    }
}


/* Generate challenge data for shared key authentication. IEEE 802.11 specifies
 * that WEP algorithm is used for generating challenge. This should be unique,
 * but otherwise there is not really need for randomness etc. Initialize WEP
 * with pseudo random key and then use increasing IV to get unique challenge
 * streams.
 *
 * Called only as a scheduled task for pending AP frames.
 */
static char * ap_auth_make_challenge(struct ap_data *ap)
{
    char *tmpbuf;
    struct sk_buff *skb;

    if (ap->crypt == NULL) {
        ap_crypt_init(ap);
        if (ap->crypt == NULL)
            return NULL;
    }

    tmpbuf = kmalloc(WLAN_AUTH_CHALLENGE_LEN, GFP_ATOMIC);
    if (tmpbuf == NULL) {
        PDEBUG(DEBUG_AP, "AP: kmalloc failed for challenge\n");
        return NULL;
    }

    skb = dev_alloc_skb(WLAN_AUTH_CHALLENGE_LEN +
                ap->crypt->extra_mpdu_prefix_len +
                ap->crypt->extra_mpdu_postfix_len);
    if (skb == NULL) {
        kfree(tmpbuf);
        return NULL;
    }

    skb_reserve(skb, ap->crypt->extra_mpdu_prefix_len);
    memset(skb_put(skb, WLAN_AUTH_CHALLENGE_LEN), 0,
           WLAN_AUTH_CHALLENGE_LEN);
    if (ap->crypt->encrypt_mpdu(skb, 0, ap->crypt_priv)) {
        dev_kfree_skb(skb);
        kfree(tmpbuf);
        return NULL;
    }

    skb_copy_from_linear_data_offset(skb, ap->crypt->extra_mpdu_prefix_len,
                     tmpbuf, WLAN_AUTH_CHALLENGE_LEN);
    dev_kfree_skb(skb);

    return tmpbuf;
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_authen(local_info_t *local, struct sk_buff *skb,
              struct hostap_80211_rx_status *rx_stats)
{
    struct net_device *dev = local->dev;
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
    size_t hdrlen;
    struct ap_data *ap = local->ap;
    char body[8 + WLAN_AUTH_CHALLENGE_LEN], *challenge = NULL;
    int len, olen;
    u16 auth_alg, auth_transaction, status_code;
    __le16 *pos;
    u16 resp = WLAN_STATUS_SUCCESS;
    struct sta_info *sta = NULL;
    struct lib80211_crypt_data *crypt;
    char *txt = "";

    len = skb->len - IEEE80211_MGMT_HDR_LEN;

    hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);

    if (len < 6) {
        PDEBUG(DEBUG_AP, "%s: handle_authen - too short payload "
               "(len=%d) from %pM\n", dev->name, len, hdr->addr2);
        return;
    }

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&local->ap->sta_table_lock);

    if (sta && sta->crypt)
        crypt = sta->crypt;
    else {
        int idx = 0;
        if (skb->len >= hdrlen + 3)
            idx = skb->data[hdrlen + 3] >> 6;
        crypt = local->crypt_info.crypt[idx];
    }

    pos = (__le16 *) (skb->data + IEEE80211_MGMT_HDR_LEN);
    auth_alg = __le16_to_cpu(*pos);
    pos++;
    auth_transaction = __le16_to_cpu(*pos);
    pos++;
    status_code = __le16_to_cpu(*pos);
    pos++;

    if (memcmp(dev->dev_addr, hdr->addr2, ETH_ALEN) == 0 ||
        ap_control_mac_deny(&ap->mac_restrictions, hdr->addr2)) {
        txt = "authentication denied";
        resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
        goto fail;
    }

    if (((local->auth_algs & PRISM2_AUTH_OPEN) &&
         auth_alg == WLAN_AUTH_OPEN) ||
        ((local->auth_algs & PRISM2_AUTH_SHARED_KEY) &&
         crypt && auth_alg == WLAN_AUTH_SHARED_KEY)) {
    } else {
        txt = "unsupported algorithm";
        resp = WLAN_STATUS_NOT_SUPPORTED_AUTH_ALG;
        goto fail;
    }

    if (len >= 8) {
        u8 *u = (u8 *) pos;
        if (*u == WLAN_EID_CHALLENGE) {
            if (*(u + 1) != WLAN_AUTH_CHALLENGE_LEN) {
                txt = "invalid challenge len";
                resp = WLAN_STATUS_CHALLENGE_FAIL;
                goto fail;
            }
            if (len - 8 < WLAN_AUTH_CHALLENGE_LEN) {
                txt = "challenge underflow";
                resp = WLAN_STATUS_CHALLENGE_FAIL;
                goto fail;
            }
            challenge = (char *) (u + 2);
        }
    }

    if (sta && sta->ap) {
        if (time_after(jiffies, sta->u.ap.last_beacon +
                   (10 * sta->listen_interval * HZ) / 1024)) {
            PDEBUG(DEBUG_AP, "%s: no beacons received for a while,"
                   " assuming AP %pM is now STA\n",
                   dev->name, sta->addr);
            sta->ap = 0;
            sta->flags = 0;
            sta->u.sta.challenge = NULL;
        } else {
            txt = "AP trying to authenticate?";
            resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
            goto fail;
        }
    }

    if ((auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) ||
        (auth_alg == WLAN_AUTH_SHARED_KEY &&
         (auth_transaction == 1 ||
          (auth_transaction == 3 && sta != NULL &&
           sta->u.sta.challenge != NULL)))) {
    } else {
        txt = "unknown authentication transaction number";
        resp = WLAN_STATUS_UNKNOWN_AUTH_TRANSACTION;
        goto fail;
    }

    if (sta == NULL) {
        txt = "new STA";

        if (local->ap->num_sta >= MAX_STA_COUNT) {
            /* FIX: might try to remove some old STAs first? */
            txt = "no more room for new STAs";
            resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
            goto fail;
        }

        sta = ap_add_sta(local->ap, hdr->addr2);
        if (sta == NULL) {
            txt = "ap_add_sta failed";
            resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
            goto fail;
        }
    }

    switch (auth_alg) {
    case WLAN_AUTH_OPEN:
        txt = "authOK";
        /* IEEE 802.11 standard is not completely clear about
         * whether STA is considered authenticated after
         * authentication OK frame has been send or after it
         * has been ACKed. In order to reduce interoperability
         * issues, mark the STA authenticated before ACK. */
        sta->flags |= WLAN_STA_AUTH;
        break;

    case WLAN_AUTH_SHARED_KEY:
        if (auth_transaction == 1) {
            if (sta->u.sta.challenge == NULL) {
                sta->u.sta.challenge =
                    ap_auth_make_challenge(local->ap);
                if (sta->u.sta.challenge == NULL) {
                    resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
                    goto fail;
                }
            }
        } else {
            if (sta->u.sta.challenge == NULL ||
                challenge == NULL ||
                memcmp(sta->u.sta.challenge, challenge,
                   WLAN_AUTH_CHALLENGE_LEN) != 0 ||
                !ieee80211_has_protected(hdr->frame_control)) {
                txt = "challenge response incorrect";
                resp = WLAN_STATUS_CHALLENGE_FAIL;
                goto fail;
            }

            txt = "challenge OK - authOK";
            /* IEEE 802.11 standard is not completely clear about
             * whether STA is considered authenticated after
             * authentication OK frame has been send or after it
             * has been ACKed. In order to reduce interoperability
             * issues, mark the STA authenticated before ACK. */
            sta->flags |= WLAN_STA_AUTH;
            kfree(sta->u.sta.challenge);
            sta->u.sta.challenge = NULL;
        }
        break;
    }

 fail:
    pos = (__le16 *) body;
    *pos = cpu_to_le16(auth_alg);
    pos++;
    *pos = cpu_to_le16(auth_transaction + 1);
    pos++;
    *pos = cpu_to_le16(resp); /* status_code */
    pos++;
    olen = 6;

    if (resp == WLAN_STATUS_SUCCESS && sta != NULL &&
        sta->u.sta.challenge != NULL &&
        auth_alg == WLAN_AUTH_SHARED_KEY && auth_transaction == 1) {
        u8 *tmp = (u8 *) pos;
        *tmp++ = WLAN_EID_CHALLENGE;
        *tmp++ = WLAN_AUTH_CHALLENGE_LEN;
        pos++;
        memcpy(pos, sta->u.sta.challenge, WLAN_AUTH_CHALLENGE_LEN);
        olen += 2 + WLAN_AUTH_CHALLENGE_LEN;
    }

    prism2_send_mgmt(dev, IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_AUTH,
             body, olen, hdr->addr2, ap->tx_callback_auth);

    if (sta) {
        sta->last_rx = jiffies;
        atomic_dec(&sta->users);
    }

    if (resp) {
        PDEBUG(DEBUG_AP, "%s: %pM auth (alg=%d "
               "trans#=%d stat=%d len=%d fc=%04x) ==> %d (%s)\n",
               dev->name, hdr->addr2,
               auth_alg, auth_transaction, status_code, len,
               le16_to_cpu(hdr->frame_control), resp, txt);
    }
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_assoc(local_info_t *local, struct sk_buff *skb,
             struct hostap_80211_rx_status *rx_stats, int reassoc)
{
    struct net_device *dev = local->dev;
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
    char body[12], *p, *lpos;
    int len, left;
    __le16 *pos;
    u16 resp = WLAN_STATUS_SUCCESS;
    struct sta_info *sta = NULL;
    int send_deauth = 0;
    char *txt = "";
    u8 prev_ap[ETH_ALEN];

    left = len = skb->len - IEEE80211_MGMT_HDR_LEN;

    if (len < (reassoc ? 10 : 4)) {
        PDEBUG(DEBUG_AP, "%s: handle_assoc - too short payload "
               "(len=%d, reassoc=%d) from %pM\n",
               dev->name, len, reassoc, hdr->addr2);
        return;
    }

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta == NULL || (sta->flags & WLAN_STA_AUTH) == 0) {
        spin_unlock_bh(&local->ap->sta_table_lock);
        txt = "trying to associate before authentication";
        send_deauth = 1;
        resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
        sta = NULL; /* do not decrement sta->users */
        goto fail;
    }
    atomic_inc(&sta->users);
    spin_unlock_bh(&local->ap->sta_table_lock);

    pos = (__le16 *) (skb->data + IEEE80211_MGMT_HDR_LEN);
    sta->capability = __le16_to_cpu(*pos);
    pos++; left -= 2;
    sta->listen_interval = __le16_to_cpu(*pos);
    pos++; left -= 2;

    if (reassoc) {
        memcpy(prev_ap, pos, ETH_ALEN);
        pos++; pos++; pos++; left -= 6;
    } else
        memset(prev_ap, 0, ETH_ALEN);

    if (left >= 2) {
        unsigned int ileft;
        unsigned char *u = (unsigned char *) pos;

        if (*u == WLAN_EID_SSID) {
            u++; left--;
            ileft = *u;
            u++; left--;

            if (ileft > left || ileft > MAX_SSID_LEN) {
                txt = "SSID overflow";
                resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
                goto fail;
            }

            if (ileft != strlen(local->essid) ||
                memcmp(local->essid, u, ileft) != 0) {
                txt = "not our SSID";
                resp = WLAN_STATUS_ASSOC_DENIED_UNSPEC;
                goto fail;
            }

            u += ileft;
            left -= ileft;
        }

        if (left >= 2 && *u == WLAN_EID_SUPP_RATES) {
            u++; left--;
            ileft = *u;
            u++; left--;

            if (ileft > left || ileft == 0 ||
                ileft > WLAN_SUPP_RATES_MAX) {
                txt = "SUPP_RATES len error";
                resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
                goto fail;
            }

            memset(sta->supported_rates, 0,
                   sizeof(sta->supported_rates));
            memcpy(sta->supported_rates, u, ileft);
            prism2_check_tx_rates(sta);

            u += ileft;
            left -= ileft;
        }

        if (left > 0) {
            PDEBUG(DEBUG_AP, "%s: assoc from %pM"
                   " with extra data (%d bytes) [",
                   dev->name, hdr->addr2, left);
            while (left > 0) {
                PDEBUG2(DEBUG_AP, "<%02x>", *u);
                u++; left--;
            }
            PDEBUG2(DEBUG_AP, "]\n");
        }
    } else {
        txt = "frame underflow";
        resp = WLAN_STATUS_UNSPECIFIED_FAILURE;
        goto fail;
    }

    /* get a unique AID */
    if (sta->aid > 0)
        txt = "OK, old AID";
    else {
        spin_lock_bh(&local->ap->sta_table_lock);
        for (sta->aid = 1; sta->aid <= MAX_AID_TABLE_SIZE; sta->aid++)
            if (local->ap->sta_aid[sta->aid - 1] == NULL)
                break;
        if (sta->aid > MAX_AID_TABLE_SIZE) {
            sta->aid = 0;
            spin_unlock_bh(&local->ap->sta_table_lock);
            resp = WLAN_STATUS_AP_UNABLE_TO_HANDLE_NEW_STA;
            txt = "no room for more AIDs";
        } else {
            local->ap->sta_aid[sta->aid - 1] = sta;
            spin_unlock_bh(&local->ap->sta_table_lock);
            txt = "OK, new AID";
        }
    }

 fail:
    pos = (__le16 *) body;

    if (send_deauth) {
        *pos = cpu_to_le16(WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH);
        pos++;
    } else {
        /* FIX: CF-Pollable and CF-PollReq should be set to match the
         * values in beacons/probe responses */
        /* FIX: how about privacy and WEP? */
        /* capability */
        *pos = cpu_to_le16(WLAN_CAPABILITY_ESS);
        pos++;

        /* status_code */
        *pos = cpu_to_le16(resp);
        pos++;

        *pos = cpu_to_le16((sta && sta->aid > 0 ? sta->aid : 0) |
                     BIT(14) | BIT(15)); /* AID */
        pos++;

        /* Supported rates (Information element) */
        p = (char *) pos;
        *p++ = WLAN_EID_SUPP_RATES;
        lpos = p;
        *p++ = 0; /* len */
        if (local->tx_rate_control & WLAN_RATE_1M) {
            *p++ = local->basic_rates & WLAN_RATE_1M ? 0x82 : 0x02;
            (*lpos)++;
        }
        if (local->tx_rate_control & WLAN_RATE_2M) {
            *p++ = local->basic_rates & WLAN_RATE_2M ? 0x84 : 0x04;
            (*lpos)++;
        }
        if (local->tx_rate_control & WLAN_RATE_5M5) {
            *p++ = local->basic_rates & WLAN_RATE_5M5 ?
                0x8b : 0x0b;
            (*lpos)++;
        }
        if (local->tx_rate_control & WLAN_RATE_11M) {
            *p++ = local->basic_rates & WLAN_RATE_11M ?
                0x96 : 0x16;
            (*lpos)++;
        }
        pos = (__le16 *) p;
    }

    prism2_send_mgmt(dev, IEEE80211_FTYPE_MGMT |
             (send_deauth ? IEEE80211_STYPE_DEAUTH :
              (reassoc ? IEEE80211_STYPE_REASSOC_RESP :
               IEEE80211_STYPE_ASSOC_RESP)),
             body, (u8 *) pos - (u8 *) body,
             hdr->addr2,
             send_deauth ? 0 : local->ap->tx_callback_assoc);

    if (sta) {
        if (resp == WLAN_STATUS_SUCCESS) {
            sta->last_rx = jiffies;
            /* STA will be marked associated from TX callback, if
             * AssocResp is ACKed */
        }
        atomic_dec(&sta->users);
    }

#if 0
    PDEBUG(DEBUG_AP, "%s: %pM %sassoc (len=%d "
           "prev_ap=%pM) => %d(%d) (%s)\n",
           dev->name,
           hdr->addr2,
           reassoc ? "re" : "", len,
           prev_ap,
           resp, send_deauth, txt);
#endif
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_deauth(local_info_t *local, struct sk_buff *skb,
              struct hostap_80211_rx_status *rx_stats)
{
    struct net_device *dev = local->dev;
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
    char *body = (char *) (skb->data + IEEE80211_MGMT_HDR_LEN);
    int len;
    u16 reason_code;
    __le16 *pos;
    struct sta_info *sta = NULL;

    len = skb->len - IEEE80211_MGMT_HDR_LEN;

    if (len < 2) {
        printk("handle_deauth - too short payload (len=%d)\n", len);
        return;
    }

    pos = (__le16 *) body;
    reason_code = le16_to_cpu(*pos);

    PDEBUG(DEBUG_AP, "%s: deauthentication: %pM len=%d, "
           "reason_code=%d\n", dev->name, hdr->addr2,
           len, reason_code);

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta != NULL) {
        if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap)
            hostap_event_expired_sta(local->dev, sta);
        sta->flags &= ~(WLAN_STA_AUTH | WLAN_STA_ASSOC);
    }
    spin_unlock_bh(&local->ap->sta_table_lock);
    if (sta == NULL) {
        printk("%s: deauthentication from %pM, "
           "reason_code=%d, but STA not authenticated\n", dev->name,
               hdr->addr2, reason_code);
    }
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_disassoc(local_info_t *local, struct sk_buff *skb,
                struct hostap_80211_rx_status *rx_stats)
{
    struct net_device *dev = local->dev;
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
    char *body = skb->data + IEEE80211_MGMT_HDR_LEN;
    int len;
    u16 reason_code;
    __le16 *pos;
    struct sta_info *sta = NULL;

    len = skb->len - IEEE80211_MGMT_HDR_LEN;

    if (len < 2) {
        printk("handle_disassoc - too short payload (len=%d)\n", len);
        return;
    }

    pos = (__le16 *) body;
    reason_code = le16_to_cpu(*pos);

    PDEBUG(DEBUG_AP, "%s: disassociation: %pM len=%d, "
           "reason_code=%d\n", dev->name, hdr->addr2,
           len, reason_code);

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta != NULL) {
        if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap)
            hostap_event_expired_sta(local->dev, sta);
        sta->flags &= ~WLAN_STA_ASSOC;
    }
    spin_unlock_bh(&local->ap->sta_table_lock);
    if (sta == NULL) {
        printk("%s: disassociation from %pM, "
               "reason_code=%d, but STA not authenticated\n",
               dev->name, hdr->addr2, reason_code);
    }
}


/* Called only as a scheduled task for pending AP frames. */
static void ap_handle_data_nullfunc(local_info_t *local,
                    struct ieee80211_hdr *hdr)
{
    struct net_device *dev = local->dev;

    /* some STA f/w's seem to require control::ACK frame for
     * data::nullfunc, but at least Prism2 station f/w version 0.8.0 does
     * not send this..
     * send control::ACK for the data::nullfunc */

    printk(KERN_DEBUG "Sending control::ACK for data::nullfunc\n");
    prism2_send_mgmt(dev, IEEE80211_FTYPE_CTL | IEEE80211_STYPE_ACK,
             NULL, 0, hdr->addr2, 0);
}


/* Called only as a scheduled task for pending AP frames. */
static void ap_handle_dropped_data(local_info_t *local,
                   struct ieee80211_hdr *hdr)
{
    struct net_device *dev = local->dev;
    struct sta_info *sta;
    __le16 reason;

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&local->ap->sta_table_lock);

    if (sta != NULL && (sta->flags & WLAN_STA_ASSOC)) {
        PDEBUG(DEBUG_AP, "ap_handle_dropped_data: STA is now okay?\n");
        atomic_dec(&sta->users);
        return;
    }

    reason = cpu_to_le16(WLAN_REASON_CLASS3_FRAME_FROM_NONASSOC_STA);
    prism2_send_mgmt(dev, IEEE80211_FTYPE_MGMT |
             ((sta == NULL || !(sta->flags & WLAN_STA_ASSOC)) ?
              IEEE80211_STYPE_DEAUTH : IEEE80211_STYPE_DISASSOC),
             (char *) &reason, sizeof(reason), hdr->addr2, 0);

    if (sta)
        atomic_dec(&sta->users);
}

#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


/* Called only as a scheduled task for pending AP frames. */
static void pspoll_send_buffered(local_info_t *local, struct sta_info *sta,
                 struct sk_buff *skb)
{
    struct hostap_skb_tx_data *meta;

    if (!(sta->flags & WLAN_STA_PS)) {
        /* Station has moved to non-PS mode, so send all buffered
         * frames using normal device queue. */
        dev_queue_xmit(skb);
        return;
    }

    /* add a flag for hostap_handle_sta_tx() to know that this skb should
     * be passed through even though STA is using PS */
    meta = (struct hostap_skb_tx_data *) skb->cb;
    meta->flags |= HOSTAP_TX_FLAGS_BUFFERED_FRAME;
    if (!skb_queue_empty(&sta->tx_buf)) {
        /* indicate to STA that more frames follow */
        meta->flags |= HOSTAP_TX_FLAGS_ADD_MOREDATA;
    }
    dev_queue_xmit(skb);
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_pspoll(local_info_t *local,
              struct ieee80211_hdr *hdr,
              struct hostap_80211_rx_status *rx_stats)
{
    struct net_device *dev = local->dev;
    struct sta_info *sta;
    u16 aid;
    struct sk_buff *skb;

    PDEBUG(DEBUG_PS2, "handle_pspoll: BSSID=%pM, TA=%pM PWRMGT=%d\n",
           hdr->addr1, hdr->addr2, !!ieee80211_has_pm(hdr->frame_control));

    if (memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN)) {
        PDEBUG(DEBUG_AP,
               "handle_pspoll - addr1(BSSID)=%pM not own MAC\n",
               hdr->addr1);
        return;
    }

    aid = le16_to_cpu(hdr->duration_id);
    if ((aid & (BIT(15) | BIT(14))) != (BIT(15) | BIT(14))) {
        PDEBUG(DEBUG_PS, "   PSPOLL and AID[15:14] not set\n");
        return;
    }
    aid &= ~(BIT(15) | BIT(14));
    if (aid == 0 || aid > MAX_AID_TABLE_SIZE) {
        PDEBUG(DEBUG_PS, "   invalid aid=%d\n", aid);
        return;
    }
    PDEBUG(DEBUG_PS2, "   aid=%d\n", aid);

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&local->ap->sta_table_lock);

    if (sta == NULL) {
        PDEBUG(DEBUG_PS, "   STA not found\n");
        return;
    }
    if (sta->aid != aid) {
        PDEBUG(DEBUG_PS, "   received aid=%i does not match with "
               "assoc.aid=%d\n", aid, sta->aid);
        return;
    }

    /* FIX: todo:
     * - add timeout for buffering (clear aid in TIM vector if buffer timed
     *   out (expiry time must be longer than ListenInterval for
     *   the corresponding STA; "8802-11: 11.2.1.9 AP aging function"
     * - what to do, if buffered, pspolled, and sent frame is not ACKed by
     *   sta; store buffer for later use and leave TIM aid bit set? use
     *   TX event to check whether frame was ACKed?
     */

    while ((skb = skb_dequeue(&sta->tx_buf)) != NULL) {
        /* send buffered frame .. */
        PDEBUG(DEBUG_PS2, "Sending buffered frame to STA after PS POLL"
               " (buffer_count=%d)\n", skb_queue_len(&sta->tx_buf));

        pspoll_send_buffered(local, sta, skb);

        if (sta->flags & WLAN_STA_PS) {
            /* send only one buffered packet per PS Poll */
            /* FIX: should ignore further PS Polls until the
             * buffered packet that was just sent is acknowledged
             * (Tx or TxExc event) */
            break;
        }
    }

    if (skb_queue_empty(&sta->tx_buf)) {
        /* try to clear aid from TIM */
        if (!(sta->flags & WLAN_STA_TIM))
            PDEBUG(DEBUG_PS2,  "Re-unsetting TIM for aid %d\n",
                   aid);
        hostap_set_tim(local, aid, 0);
        sta->flags &= ~WLAN_STA_TIM;
    }

    atomic_dec(&sta->users);
}


#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT

static void handle_wds_oper_queue(struct work_struct *work)
{
    struct ap_data *ap = container_of(work, struct ap_data,
                      wds_oper_queue);
    local_info_t *local = ap->local;
    struct wds_oper_data *entry, *prev;

    spin_lock_bh(&local->lock);
    entry = local->ap->wds_oper_entries;
    local->ap->wds_oper_entries = NULL;
    spin_unlock_bh(&local->lock);

    while (entry) {
        PDEBUG(DEBUG_AP, "%s: %s automatic WDS connection "
               "to AP %pM\n",
               local->dev->name,
               entry->type == WDS_ADD ? "adding" : "removing",
               entry->addr);
        if (entry->type == WDS_ADD)
            prism2_wds_add(local, entry->addr, 0);
        else if (entry->type == WDS_DEL)
            prism2_wds_del(local, entry->addr, 0, 1);

        prev = entry;
        entry = entry->next;
        kfree(prev);
    }
}


/* Called only as a scheduled task for pending AP frames. */
static void handle_beacon(local_info_t *local, struct sk_buff *skb,
              struct hostap_80211_rx_status *rx_stats)
{
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
    char *body = skb->data + IEEE80211_MGMT_HDR_LEN;
    int len, left;
    u16 beacon_int, capability;
    __le16 *pos;
    char *ssid = NULL;
    unsigned char *supp_rates = NULL;
    int ssid_len = 0, supp_rates_len = 0;
    struct sta_info *sta = NULL;
    int new_sta = 0, channel = -1;

    len = skb->len - IEEE80211_MGMT_HDR_LEN;

    if (len < 8 + 2 + 2) {
        printk(KERN_DEBUG "handle_beacon - too short payload "
               "(len=%d)\n", len);
        return;
    }

    pos = (__le16 *) body;
    left = len;

    /* Timestamp (8 octets) */
    pos += 4; left -= 8;
    /* Beacon interval (2 octets) */
    beacon_int = le16_to_cpu(*pos);
    pos++; left -= 2;
    /* Capability information (2 octets) */
    capability = le16_to_cpu(*pos);
    pos++; left -= 2;

    if (local->ap->ap_policy != AP_OTHER_AP_EVEN_IBSS &&
        capability & WLAN_CAPABILITY_IBSS)
        return;

    if (left >= 2) {
        unsigned int ileft;
        unsigned char *u = (unsigned char *) pos;

        if (*u == WLAN_EID_SSID) {
            u++; left--;
            ileft = *u;
            u++; left--;

            if (ileft > left || ileft > MAX_SSID_LEN) {
                PDEBUG(DEBUG_AP, "SSID: overflow\n");
                return;
            }

            if (local->ap->ap_policy == AP_OTHER_AP_SAME_SSID &&
                (ileft != strlen(local->essid) ||
                 memcmp(local->essid, u, ileft) != 0)) {
                /* not our SSID */
                return;
            }

            ssid = u;
            ssid_len = ileft;

            u += ileft;
            left -= ileft;
        }

        if (*u == WLAN_EID_SUPP_RATES) {
            u++; left--;
            ileft = *u;
            u++; left--;

            if (ileft > left || ileft == 0 || ileft > 8) {
                PDEBUG(DEBUG_AP, " - SUPP_RATES len error\n");
                return;
            }

            supp_rates = u;
            supp_rates_len = ileft;

            u += ileft;
            left -= ileft;
        }

        if (*u == WLAN_EID_DS_PARAMS) {
            u++; left--;
            ileft = *u;
            u++; left--;

            if (ileft > left || ileft != 1) {
                PDEBUG(DEBUG_AP, " - DS_PARAMS len error\n");
                return;
            }

            channel = *u;

            u += ileft;
            left -= ileft;
        }
    }

    spin_lock_bh(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta != NULL)
        atomic_inc(&sta->users);
    spin_unlock_bh(&local->ap->sta_table_lock);

    if (sta == NULL) {
        /* add new AP */
        new_sta = 1;
        sta = ap_add_sta(local->ap, hdr->addr2);
        if (sta == NULL) {
            printk(KERN_INFO "prism2: kmalloc failed for AP "
                   "data structure\n");
            return;
        }
        hostap_event_new_sta(local->dev, sta);

        /* mark APs authentication and associated for pseudo ad-hoc
         * style communication */
        sta->flags = WLAN_STA_AUTH | WLAN_STA_ASSOC;

        if (local->ap->autom_ap_wds) {
            hostap_wds_link_oper(local, sta->addr, WDS_ADD);
        }
    }

    sta->ap = 1;
    if (ssid) {
        sta->u.ap.ssid_len = ssid_len;
        memcpy(sta->u.ap.ssid, ssid, ssid_len);
        sta->u.ap.ssid[ssid_len] = '\0';
    } else {
        sta->u.ap.ssid_len = 0;
        sta->u.ap.ssid[0] = '\0';
    }
    sta->u.ap.channel = channel;
    sta->rx_packets++;
    sta->rx_bytes += len;
    sta->u.ap.last_beacon = sta->last_rx = jiffies;
    sta->capability = capability;
    sta->listen_interval = beacon_int;

    atomic_dec(&sta->users);

    if (new_sta) {
        memset(sta->supported_rates, 0, sizeof(sta->supported_rates));
        memcpy(sta->supported_rates, supp_rates, supp_rates_len);
        prism2_check_tx_rates(sta);
    }
}

#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */


/* Called only as a tasklet. */
static void handle_ap_item(local_info_t *local, struct sk_buff *skb,
               struct hostap_80211_rx_status *rx_stats)
{
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    struct net_device *dev = local->dev;
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */
    u16 fc, type, stype;
    struct ieee80211_hdr *hdr;

    /* FIX: should give skb->len to handler functions and check that the
     * buffer is long enough */
    hdr = (struct ieee80211_hdr *) skb->data;
    fc = le16_to_cpu(hdr->frame_control);
    type = fc & IEEE80211_FCTL_FTYPE;
    stype = fc & IEEE80211_FCTL_STYPE;

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    if (!local->hostapd && type == IEEE80211_FTYPE_DATA) {
        PDEBUG(DEBUG_AP, "handle_ap_item - data frame\n");

        if (!(fc & IEEE80211_FCTL_TODS) ||
            (fc & IEEE80211_FCTL_FROMDS)) {
            if (stype == IEEE80211_STYPE_NULLFUNC) {
                /* no ToDS nullfunc seems to be used to check
                 * AP association; so send reject message to
                 * speed up re-association */
                ap_handle_dropped_data(local, hdr);
                goto done;
            }
            PDEBUG(DEBUG_AP, "   not ToDS frame (fc=0x%04x)\n",
                   fc);
            goto done;
        }

        if (memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN)) {
            PDEBUG(DEBUG_AP, "handle_ap_item - addr1(BSSID)=%pM"
                   " not own MAC\n", hdr->addr1);
            goto done;
        }

        if (local->ap->nullfunc_ack &&
            stype == IEEE80211_STYPE_NULLFUNC)
            ap_handle_data_nullfunc(local, hdr);
        else
            ap_handle_dropped_data(local, hdr);
        goto done;
    }

    if (type == IEEE80211_FTYPE_MGMT && stype == IEEE80211_STYPE_BEACON) {
        handle_beacon(local, skb, rx_stats);
        goto done;
    }
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

    if (type == IEEE80211_FTYPE_CTL && stype == IEEE80211_STYPE_PSPOLL) {
        handle_pspoll(local, hdr, rx_stats);
        goto done;
    }

    if (local->hostapd) {
        PDEBUG(DEBUG_AP, "Unknown frame in AP queue: type=0x%02x "
               "subtype=0x%02x\n", type, stype);
        goto done;
    }

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
    if (type != IEEE80211_FTYPE_MGMT) {
        PDEBUG(DEBUG_AP, "handle_ap_item - not a management frame?\n");
        goto done;
    }

    if (memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN)) {
        PDEBUG(DEBUG_AP, "handle_ap_item - addr1(DA)=%pM"
               " not own MAC\n", hdr->addr1);
        goto done;
    }

    if (memcmp(hdr->addr3, dev->dev_addr, ETH_ALEN)) {
        PDEBUG(DEBUG_AP, "handle_ap_item - addr3(BSSID)=%pM"
               " not own MAC\n", hdr->addr3);
        goto done;
    }

    switch (stype) {
    case IEEE80211_STYPE_ASSOC_REQ:
        handle_assoc(local, skb, rx_stats, 0);
        break;
    case IEEE80211_STYPE_ASSOC_RESP:
        PDEBUG(DEBUG_AP, "==> ASSOC RESP (ignored)\n");
        break;
    case IEEE80211_STYPE_REASSOC_REQ:
        handle_assoc(local, skb, rx_stats, 1);
        break;
    case IEEE80211_STYPE_REASSOC_RESP:
        PDEBUG(DEBUG_AP, "==> REASSOC RESP (ignored)\n");
        break;
    case IEEE80211_STYPE_ATIM:
        PDEBUG(DEBUG_AP, "==> ATIM (ignored)\n");
        break;
    case IEEE80211_STYPE_DISASSOC:
        handle_disassoc(local, skb, rx_stats);
        break;
    case IEEE80211_STYPE_AUTH:
        handle_authen(local, skb, rx_stats);
        break;
    case IEEE80211_STYPE_DEAUTH:
        handle_deauth(local, skb, rx_stats);
        break;
    default:
        PDEBUG(DEBUG_AP, "Unknown mgmt frame subtype 0x%02x\n",
               stype >> 4);
        break;
    }
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

 done:
    dev_kfree_skb(skb);
}


/* Called only as a tasklet (software IRQ) */
void hostap_rx(struct net_device *dev, struct sk_buff *skb,
           struct hostap_80211_rx_status *rx_stats)
{
    struct hostap_interface *iface;
    local_info_t *local;
    struct ieee80211_hdr *hdr;

    iface = netdev_priv(dev);
    local = iface->local;

    if (skb->len < 16)
        goto drop;

    dev->stats.rx_packets++;

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

    if (local->ap->ap_policy == AP_OTHER_AP_SKIP_ALL &&
        ieee80211_is_beacon(hdr->frame_control))
        goto drop;

    skb->protocol = cpu_to_be16(ETH_P_HOSTAP);
    handle_ap_item(local, skb, rx_stats);
    return;

 drop:
    dev_kfree_skb(skb);
}


/* Called only as a tasklet (software IRQ) */
static void schedule_packet_send(local_info_t *local, struct sta_info *sta)
{
    struct sk_buff *skb;
    struct ieee80211_hdr *hdr;
    struct hostap_80211_rx_status rx_stats;

    if (skb_queue_empty(&sta->tx_buf))
        return;

    skb = dev_alloc_skb(16);
    if (skb == NULL) {
        printk(KERN_DEBUG "%s: schedule_packet_send: skb alloc "
               "failed\n", local->dev->name);
        return;
    }

    hdr = (struct ieee80211_hdr *) skb_put(skb, 16);

    /* Generate a fake pspoll frame to start packet delivery */
    hdr->frame_control = cpu_to_le16(
        IEEE80211_FTYPE_CTL | IEEE80211_STYPE_PSPOLL);
    memcpy(hdr->addr1, local->dev->dev_addr, ETH_ALEN);
    memcpy(hdr->addr2, sta->addr, ETH_ALEN);
    hdr->duration_id = cpu_to_le16(sta->aid | BIT(15) | BIT(14));

    PDEBUG(DEBUG_PS2,
           "%s: Scheduling buffered packet delivery for STA %pM\n",
           local->dev->name, sta->addr);

    skb->dev = local->dev;

    memset(&rx_stats, 0, sizeof(rx_stats));
    hostap_rx(local->dev, skb, &rx_stats);
}


int prism2_ap_get_sta_qual(local_info_t *local, struct sockaddr addr[],
               struct iw_quality qual[], int buf_size,
               int aplist)
{
    struct ap_data *ap = local->ap;
    struct list_head *ptr;
    int count = 0;

    spin_lock_bh(&ap->sta_table_lock);

    for (ptr = ap->sta_list.next; ptr != NULL && ptr != &ap->sta_list;
         ptr = ptr->next) {
        struct sta_info *sta = (struct sta_info *) ptr;

        if (aplist && !sta->ap)
            continue;
        addr[count].sa_family = ARPHRD_ETHER;
        memcpy(addr[count].sa_data, sta->addr, ETH_ALEN);
        if (sta->last_rx_silence == 0)
            qual[count].qual = sta->last_rx_signal < 27 ?
                0 : (sta->last_rx_signal - 27) * 92 / 127;
        else
            qual[count].qual = sta->last_rx_signal -
                sta->last_rx_silence - 35;
        qual[count].level = HFA384X_LEVEL_TO_dBm(sta->last_rx_signal);
        qual[count].noise = HFA384X_LEVEL_TO_dBm(sta->last_rx_silence);
        qual[count].updated = sta->last_rx_updated;

        sta->last_rx_updated = IW_QUAL_DBM;

        count++;
        if (count >= buf_size)
            break;
    }
    spin_unlock_bh(&ap->sta_table_lock);

    return count;
}


/* Translate our list of Access Points & Stations to a card independent
 * format that the Wireless Tools will understand - Jean II */
int prism2_ap_translate_scan(struct net_device *dev,
                 struct iw_request_info *info, char *buffer)
{
    struct hostap_interface *iface;
    local_info_t *local;
    struct ap_data *ap;
    struct list_head *ptr;
    struct iw_event iwe;
    char *current_ev = buffer;
    char *end_buf = buffer + IW_SCAN_MAX_DATA;
#if !defined(PRISM2_NO_KERNEL_IEEE80211_MGMT)
    char buf[64];
#endif

    iface = netdev_priv(dev);
    local = iface->local;
    ap = local->ap;

    spin_lock_bh(&ap->sta_table_lock);

    for (ptr = ap->sta_list.next; ptr != NULL && ptr != &ap->sta_list;
         ptr = ptr->next) {
        struct sta_info *sta = (struct sta_info *) ptr;

        /* First entry *MUST* be the AP MAC address */
        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWAP;
        iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
        memcpy(iwe.u.ap_addr.sa_data, sta->addr, ETH_ALEN);
        iwe.len = IW_EV_ADDR_LEN;
        current_ev = iwe_stream_add_event(info, current_ev, end_buf,
                          &iwe, IW_EV_ADDR_LEN);

        /* Use the mode to indicate if it's a station or
         * an Access Point */
        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = SIOCGIWMODE;
        if (sta->ap)
            iwe.u.mode = IW_MODE_MASTER;
        else
            iwe.u.mode = IW_MODE_INFRA;
        iwe.len = IW_EV_UINT_LEN;
        current_ev = iwe_stream_add_event(info, current_ev, end_buf,
                          &iwe, IW_EV_UINT_LEN);

        /* Some quality */
        memset(&iwe, 0, sizeof(iwe));
        iwe.cmd = IWEVQUAL;
        if (sta->last_rx_silence == 0)
            iwe.u.qual.qual = sta->last_rx_signal < 27 ?
                0 : (sta->last_rx_signal - 27) * 92 / 127;
        else
            iwe.u.qual.qual = sta->last_rx_signal -
                sta->last_rx_silence - 35;
        iwe.u.qual.level = HFA384X_LEVEL_TO_dBm(sta->last_rx_signal);
        iwe.u.qual.noise = HFA384X_LEVEL_TO_dBm(sta->last_rx_silence);
        iwe.u.qual.updated = sta->last_rx_updated;
        iwe.len = IW_EV_QUAL_LEN;
        current_ev = iwe_stream_add_event(info, current_ev, end_buf,
                          &iwe, IW_EV_QUAL_LEN);

#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
        if (sta->ap) {
            memset(&iwe, 0, sizeof(iwe));
            iwe.cmd = SIOCGIWESSID;
            iwe.u.data.length = sta->u.ap.ssid_len;
            iwe.u.data.flags = 1;
            current_ev = iwe_stream_add_point(info, current_ev,
                              end_buf, &iwe,
                              sta->u.ap.ssid);

            memset(&iwe, 0, sizeof(iwe));
            iwe.cmd = SIOCGIWENCODE;
            if (sta->capability & WLAN_CAPABILITY_PRIVACY)
                iwe.u.data.flags =
                    IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
            else
                iwe.u.data.flags = IW_ENCODE_DISABLED;
            current_ev = iwe_stream_add_point(info, current_ev,
                              end_buf, &iwe,
                              sta->u.ap.ssid);

            if (sta->u.ap.channel > 0 &&
                sta->u.ap.channel <= FREQ_COUNT) {
                memset(&iwe, 0, sizeof(iwe));
                iwe.cmd = SIOCGIWFREQ;
                iwe.u.freq.m = freq_list[sta->u.ap.channel - 1]
                    * 100000;
                iwe.u.freq.e = 1;
                current_ev = iwe_stream_add_event(
                    info, current_ev, end_buf, &iwe,
                    IW_EV_FREQ_LEN);
            }

            memset(&iwe, 0, sizeof(iwe));
            iwe.cmd = IWEVCUSTOM;
            sprintf(buf, "beacon_interval=%d",
                sta->listen_interval);
            iwe.u.data.length = strlen(buf);
            current_ev = iwe_stream_add_point(info, current_ev,
                              end_buf, &iwe, buf);
        }
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */

        sta->last_rx_updated = IW_QUAL_DBM;

        /* To be continued, we should make good use of IWEVCUSTOM */
    }

    spin_unlock_bh(&ap->sta_table_lock);

    return current_ev - buffer;
}


static int prism2_hostapd_add_sta(struct ap_data *ap,
                  struct prism2_hostapd_param *param)
{
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, param->sta_addr);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&ap->sta_table_lock);

    if (sta == NULL) {
        sta = ap_add_sta(ap, param->sta_addr);
        if (sta == NULL)
            return -1;
    }

    if (!(sta->flags & WLAN_STA_ASSOC) && !sta->ap && sta->local)
        hostap_event_new_sta(sta->local->dev, sta);

    sta->flags |= WLAN_STA_AUTH | WLAN_STA_ASSOC;
    sta->last_rx = jiffies;
    sta->aid = param->u.add_sta.aid;
    sta->capability = param->u.add_sta.capability;
    sta->tx_supp_rates = param->u.add_sta.tx_supp_rates;
    if (sta->tx_supp_rates & WLAN_RATE_1M)
        sta->supported_rates[0] = 2;
    if (sta->tx_supp_rates & WLAN_RATE_2M)
        sta->supported_rates[1] = 4;
    if (sta->tx_supp_rates & WLAN_RATE_5M5)
        sta->supported_rates[2] = 11;
    if (sta->tx_supp_rates & WLAN_RATE_11M)
        sta->supported_rates[3] = 22;
    prism2_check_tx_rates(sta);
    atomic_dec(&sta->users);
    return 0;
}


static int prism2_hostapd_remove_sta(struct ap_data *ap,
                     struct prism2_hostapd_param *param)
{
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, param->sta_addr);
    if (sta) {
        ap_sta_hash_del(ap, sta);
        list_del(&sta->list);
    }
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta)
        return -ENOENT;

    if ((sta->flags & WLAN_STA_ASSOC) && !sta->ap && sta->local)
        hostap_event_expired_sta(sta->local->dev, sta);
    ap_free_sta(ap, sta);

    return 0;
}


static int prism2_hostapd_get_info_sta(struct ap_data *ap,
                       struct prism2_hostapd_param *param)
{
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, param->sta_addr);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta)
        return -ENOENT;

    param->u.get_info_sta.inactive_sec = (jiffies - sta->last_rx) / HZ;

    atomic_dec(&sta->users);

    return 1;
}


static int prism2_hostapd_set_flags_sta(struct ap_data *ap,
                    struct prism2_hostapd_param *param)
{
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, param->sta_addr);
    if (sta) {
        sta->flags |= param->u.set_flags_sta.flags_or;
        sta->flags &= param->u.set_flags_sta.flags_and;
    }
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta)
        return -ENOENT;

    return 0;
}


static int prism2_hostapd_sta_clear_stats(struct ap_data *ap,
                      struct prism2_hostapd_param *param)
{
    struct sta_info *sta;
    int rate;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, param->sta_addr);
    if (sta) {
        sta->rx_packets = sta->tx_packets = 0;
        sta->rx_bytes = sta->tx_bytes = 0;
        for (rate = 0; rate < WLAN_RATE_COUNT; rate++) {
            sta->tx_count[rate] = 0;
            sta->rx_count[rate] = 0;
        }
    }
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta)
        return -ENOENT;

    return 0;
}


int prism2_hostapd(struct ap_data *ap, struct prism2_hostapd_param *param)
{
    switch (param->cmd) {
    case PRISM2_HOSTAPD_FLUSH:
        ap_control_kickall(ap);
        return 0;
    case PRISM2_HOSTAPD_ADD_STA:
        return prism2_hostapd_add_sta(ap, param);
    case PRISM2_HOSTAPD_REMOVE_STA:
        return prism2_hostapd_remove_sta(ap, param);
    case PRISM2_HOSTAPD_GET_INFO_STA:
        return prism2_hostapd_get_info_sta(ap, param);
    case PRISM2_HOSTAPD_SET_FLAGS_STA:
        return prism2_hostapd_set_flags_sta(ap, param);
    case PRISM2_HOSTAPD_STA_CLEAR_STATS:
        return prism2_hostapd_sta_clear_stats(ap, param);
    default:
        printk(KERN_WARNING "prism2_hostapd: unknown cmd=%d\n",
               param->cmd);
        return -EOPNOTSUPP;
    }
}


/* Update station info for host-based TX rate control and return current
 * TX rate */
static int ap_update_sta_tx_rate(struct sta_info *sta, struct net_device *dev)
{
    int ret = sta->tx_rate;
    struct hostap_interface *iface;
    local_info_t *local;

    iface = netdev_priv(dev);
    local = iface->local;

    sta->tx_count[sta->tx_rate_idx]++;
    sta->tx_since_last_failure++;
    sta->tx_consecutive_exc = 0;
    if (sta->tx_since_last_failure >= WLAN_RATE_UPDATE_COUNT &&
        sta->tx_rate_idx < sta->tx_max_rate) {
        /* use next higher rate */
        int old_rate, new_rate;
        old_rate = new_rate = sta->tx_rate_idx;
        while (new_rate < sta->tx_max_rate) {
            new_rate++;
            if (ap_tx_rate_ok(new_rate, sta, local)) {
                sta->tx_rate_idx = new_rate;
                break;
            }
        }
        if (old_rate != sta->tx_rate_idx) {
            switch (sta->tx_rate_idx) {
            case 0: sta->tx_rate = 10; break;
            case 1: sta->tx_rate = 20; break;
            case 2: sta->tx_rate = 55; break;
            case 3: sta->tx_rate = 110; break;
            default: sta->tx_rate = 0; break;
            }
            PDEBUG(DEBUG_AP, "%s: STA %pM TX rate raised to %d\n",
                   dev->name, sta->addr, sta->tx_rate);
        }
        sta->tx_since_last_failure = 0;
    }

    return ret;
}


/* Called only from software IRQ. Called for each TX frame prior possible
 * encryption and transmit. */
ap_tx_ret hostap_handle_sta_tx(local_info_t *local, struct hostap_tx_data *tx)
{
    struct sta_info *sta = NULL;
    struct sk_buff *skb = tx->skb;
    int set_tim, ret;
    struct ieee80211_hdr *hdr;
    struct hostap_skb_tx_data *meta;

    meta = (struct hostap_skb_tx_data *) skb->cb;
    ret = AP_TX_CONTINUE;
    if (local->ap == NULL || skb->len < 10 ||
        meta->iface->type == HOSTAP_INTERFACE_STA)
        goto out;

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

    if (hdr->addr1[0] & 0x01) {
        /* broadcast/multicast frame - no AP related processing */
        if (local->ap->num_sta <= 0)
            ret = AP_TX_DROP;
        goto out;
    }

    /* unicast packet - check whether destination STA is associated */
    spin_lock(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr1);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&local->ap->sta_table_lock);

    if (local->iw_mode == IW_MODE_MASTER && sta == NULL &&
        !(meta->flags & HOSTAP_TX_FLAGS_WDS) &&
        meta->iface->type != HOSTAP_INTERFACE_MASTER &&
        meta->iface->type != HOSTAP_INTERFACE_AP) {
#if 0
        /* This can happen, e.g., when wlan0 is added to a bridge and
         * bridging code does not know which port is the correct target
         * for a unicast frame. In this case, the packet is send to all
         * ports of the bridge. Since this is a valid scenario, do not
         * print out any errors here. */
        if (net_ratelimit()) {
            printk(KERN_DEBUG "AP: drop packet to non-associated "
                   "STA %pM\n", hdr->addr1);
        }
#endif
        local->ap->tx_drop_nonassoc++;
        ret = AP_TX_DROP;
        goto out;
    }

    if (sta == NULL)
        goto out;

    if (!(sta->flags & WLAN_STA_AUTHORIZED))
        ret = AP_TX_CONTINUE_NOT_AUTHORIZED;

    /* Set tx_rate if using host-based TX rate control */
    if (!local->fw_tx_rate_control)
        local->ap->last_tx_rate = meta->rate =
            ap_update_sta_tx_rate(sta, local->dev);

    if (local->iw_mode != IW_MODE_MASTER)
        goto out;

    if (!(sta->flags & WLAN_STA_PS))
        goto out;

    if (meta->flags & HOSTAP_TX_FLAGS_ADD_MOREDATA) {
        /* indicate to STA that more frames follow */
        hdr->frame_control |=
            cpu_to_le16(IEEE80211_FCTL_MOREDATA);
    }

    if (meta->flags & HOSTAP_TX_FLAGS_BUFFERED_FRAME) {
        /* packet was already buffered and now send due to
         * PS poll, so do not rebuffer it */
        goto out;
    }

    if (skb_queue_len(&sta->tx_buf) >= STA_MAX_TX_BUFFER) {
        PDEBUG(DEBUG_PS, "%s: No more space in STA (%pM)'s"
               "PS mode buffer\n",
               local->dev->name, sta->addr);
        /* Make sure that TIM is set for the station (it might not be
         * after AP wlan hw reset). */
        /* FIX: should fix hw reset to restore bits based on STA
         * buffer state.. */
        hostap_set_tim(local, sta->aid, 1);
        sta->flags |= WLAN_STA_TIM;
        ret = AP_TX_DROP;
        goto out;
    }

    /* STA in PS mode, buffer frame for later delivery */
    set_tim = skb_queue_empty(&sta->tx_buf);
    skb_queue_tail(&sta->tx_buf, skb);
    /* FIX: could save RX time to skb and expire buffered frames after
     * some time if STA does not poll for them */

    if (set_tim) {
        if (sta->flags & WLAN_STA_TIM)
            PDEBUG(DEBUG_PS2, "Re-setting TIM for aid %d\n",
                   sta->aid);
        hostap_set_tim(local, sta->aid, 1);
        sta->flags |= WLAN_STA_TIM;
    }

    ret = AP_TX_BUFFERED;

 out:
    if (sta != NULL) {
        if (ret == AP_TX_CONTINUE ||
            ret == AP_TX_CONTINUE_NOT_AUTHORIZED) {
            sta->tx_packets++;
            sta->tx_bytes += skb->len;
            sta->last_tx = jiffies;
        }

        if ((ret == AP_TX_CONTINUE ||
             ret == AP_TX_CONTINUE_NOT_AUTHORIZED) &&
            sta->crypt && tx->host_encrypt) {
            tx->crypt = sta->crypt;
            tx->sta_ptr = sta; /* hostap_handle_sta_release() will
                        * be called to release sta info
                        * later */
        } else
            atomic_dec(&sta->users);
    }

    return ret;
}


void hostap_handle_sta_release(void *ptr)
{
    struct sta_info *sta = ptr;
    atomic_dec(&sta->users);
}


/* Called only as a tasklet (software IRQ) */
void hostap_handle_sta_tx_exc(local_info_t *local, struct sk_buff *skb)
{
    struct sta_info *sta;
    struct ieee80211_hdr *hdr;
    struct hostap_skb_tx_data *meta;

    hdr = (struct ieee80211_hdr *) skb->data;
    meta = (struct hostap_skb_tx_data *) skb->cb;

    spin_lock(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr1);
    if (!sta) {
        spin_unlock(&local->ap->sta_table_lock);
        PDEBUG(DEBUG_AP, "%s: Could not find STA %pM"
               " for this TX error (@%lu)\n",
               local->dev->name, hdr->addr1, jiffies);
        return;
    }

    sta->tx_since_last_failure = 0;
    sta->tx_consecutive_exc++;

    if (sta->tx_consecutive_exc >= WLAN_RATE_DECREASE_THRESHOLD &&
        sta->tx_rate_idx > 0 && meta->rate <= sta->tx_rate) {
        /* use next lower rate */
        int old, rate;
        old = rate = sta->tx_rate_idx;
        while (rate > 0) {
            rate--;
            if (ap_tx_rate_ok(rate, sta, local)) {
                sta->tx_rate_idx = rate;
                break;
            }
        }
        if (old != sta->tx_rate_idx) {
            switch (sta->tx_rate_idx) {
            case 0: sta->tx_rate = 10; break;
            case 1: sta->tx_rate = 20; break;
            case 2: sta->tx_rate = 55; break;
            case 3: sta->tx_rate = 110; break;
            default: sta->tx_rate = 0; break;
            }
            PDEBUG(DEBUG_AP,
                   "%s: STA %pM TX rate lowered to %d\n",
                   local->dev->name, sta->addr, sta->tx_rate);
        }
        sta->tx_consecutive_exc = 0;
    }
    spin_unlock(&local->ap->sta_table_lock);
}


static void hostap_update_sta_ps2(local_info_t *local, struct sta_info *sta,
                  int pwrmgt, int type, int stype)
{
    if (pwrmgt && !(sta->flags & WLAN_STA_PS)) {
        sta->flags |= WLAN_STA_PS;
        PDEBUG(DEBUG_PS2, "STA %pM changed to use PS "
               "mode (type=0x%02X, stype=0x%02X)\n",
               sta->addr, type >> 2, stype >> 4);
    } else if (!pwrmgt && (sta->flags & WLAN_STA_PS)) {
        sta->flags &= ~WLAN_STA_PS;
        PDEBUG(DEBUG_PS2, "STA %pM changed to not use "
               "PS mode (type=0x%02X, stype=0x%02X)\n",
               sta->addr, type >> 2, stype >> 4);
        if (type != IEEE80211_FTYPE_CTL ||
            stype != IEEE80211_STYPE_PSPOLL)
            schedule_packet_send(local, sta);
    }
}


/* Called only as a tasklet (software IRQ). Called for each RX frame to update
 * STA power saving state. pwrmgt is a flag from 802.11 frame_control field. */
int hostap_update_sta_ps(local_info_t *local, struct ieee80211_hdr *hdr)
{
    struct sta_info *sta;
    u16 fc;

    spin_lock(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&local->ap->sta_table_lock);

    if (!sta)
        return -1;

    fc = le16_to_cpu(hdr->frame_control);
    hostap_update_sta_ps2(local, sta, fc & IEEE80211_FCTL_PM,
                  fc & IEEE80211_FCTL_FTYPE,
                  fc & IEEE80211_FCTL_STYPE);

    atomic_dec(&sta->users);
    return 0;
}


/* Called only as a tasklet (software IRQ). Called for each RX frame after
 * getting RX header and payload from hardware. */
ap_rx_ret hostap_handle_sta_rx(local_info_t *local, struct net_device *dev,
                   struct sk_buff *skb,
                   struct hostap_80211_rx_status *rx_stats,
                   int wds)
{
    int ret;
    struct sta_info *sta;
    u16 fc, type, stype;
    struct ieee80211_hdr *hdr;

    if (local->ap == NULL)
        return AP_RX_CONTINUE;

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

    fc = le16_to_cpu(hdr->frame_control);
    type = fc & IEEE80211_FCTL_FTYPE;
    stype = fc & IEEE80211_FCTL_STYPE;

    spin_lock(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&local->ap->sta_table_lock);

    if (sta && !(sta->flags & WLAN_STA_AUTHORIZED))
        ret = AP_RX_CONTINUE_NOT_AUTHORIZED;
    else
        ret = AP_RX_CONTINUE;


    if (fc & IEEE80211_FCTL_TODS) {
        if (!wds && (sta == NULL || !(sta->flags & WLAN_STA_ASSOC))) {
            if (local->hostapd) {
                prism2_rx_80211(local->apdev, skb, rx_stats,
                        PRISM2_RX_NON_ASSOC);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
            } else {
                printk(KERN_DEBUG "%s: dropped received packet"
                       " from non-associated STA %pM"
                       " (type=0x%02x, subtype=0x%02x)\n",
                       dev->name, hdr->addr2,
                       type >> 2, stype >> 4);
                hostap_rx(dev, skb, rx_stats);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */
            }
            ret = AP_RX_EXIT;
            goto out;
        }
    } else if (fc & IEEE80211_FCTL_FROMDS) {
        if (!wds) {
            /* FromDS frame - not for us; probably
             * broadcast/multicast in another BSS - drop */
            if (memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN) == 0) {
                printk(KERN_DEBUG "Odd.. FromDS packet "
                       "received with own BSSID\n");
                hostap_dump_rx_80211(dev->name, skb, rx_stats);
            }
            ret = AP_RX_DROP;
            goto out;
        }
    } else if (stype == IEEE80211_STYPE_NULLFUNC && sta == NULL &&
           memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN) == 0) {

        if (local->hostapd) {
            prism2_rx_80211(local->apdev, skb, rx_stats,
                    PRISM2_RX_NON_ASSOC);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
        } else {
            /* At least Lucent f/w seems to send data::nullfunc
             * frames with no ToDS flag when the current AP returns
             * after being unavailable for some time. Speed up
             * re-association by informing the station about it not
             * being associated. */
            printk(KERN_DEBUG "%s: rejected received nullfunc frame"
                   " without ToDS from not associated STA %pM\n",
                   dev->name, hdr->addr2);
            hostap_rx(dev, skb, rx_stats);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */
        }
        ret = AP_RX_EXIT;
        goto out;
    } else if (stype == IEEE80211_STYPE_NULLFUNC) {
        /* At least Lucent cards seem to send periodic nullfunc
         * frames with ToDS. Let these through to update SQ
         * stats and PS state. Nullfunc frames do not contain
         * any data and they will be dropped below. */
    } else {
        /* If BSSID (Addr3) is foreign, this frame is a normal
         * broadcast frame from an IBSS network. Drop it silently.
         * If BSSID is own, report the dropping of this frame. */
        if (memcmp(hdr->addr3, dev->dev_addr, ETH_ALEN) == 0) {
            printk(KERN_DEBUG "%s: dropped received packet from %pM"
                   " with no ToDS flag "
                   "(type=0x%02x, subtype=0x%02x)\n", dev->name,
                   hdr->addr2, type >> 2, stype >> 4);
            hostap_dump_rx_80211(dev->name, skb, rx_stats);
        }
        ret = AP_RX_DROP;
        goto out;
    }

    if (sta) {
        hostap_update_sta_ps2(local, sta, fc & IEEE80211_FCTL_PM,
                      type, stype);

        sta->rx_packets++;
        sta->rx_bytes += skb->len;
        sta->last_rx = jiffies;
    }

    if (local->ap->nullfunc_ack && stype == IEEE80211_STYPE_NULLFUNC &&
        fc & IEEE80211_FCTL_TODS) {
        if (local->hostapd) {
            prism2_rx_80211(local->apdev, skb, rx_stats,
                    PRISM2_RX_NULLFUNC_ACK);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
        } else {
            /* some STA f/w's seem to require control::ACK frame
             * for data::nullfunc, but Prism2 f/w 0.8.0 (at least
             * from Compaq) does not send this.. Try to generate
             * ACK for these frames from the host driver to make
             * power saving work with, e.g., Lucent WaveLAN f/w */
            hostap_rx(dev, skb, rx_stats);
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */
        }
        ret = AP_RX_EXIT;
        goto out;
    }

 out:
    if (sta)
        atomic_dec(&sta->users);

    return ret;
}


/* Called only as a tasklet (software IRQ) */
int hostap_handle_sta_crypto(local_info_t *local,
                 struct ieee80211_hdr *hdr,
                 struct lib80211_crypt_data **crypt,
                 void **sta_ptr)
{
    struct sta_info *sta;

    spin_lock(&local->ap->sta_table_lock);
    sta = ap_get_sta(local->ap, hdr->addr2);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock(&local->ap->sta_table_lock);

    if (!sta)
        return -1;

    if (sta->crypt) {
        *crypt = sta->crypt;
        *sta_ptr = sta;
        /* hostap_handle_sta_release() will be called to release STA
         * info */
    } else
        atomic_dec(&sta->users);

    return 0;
}


/* Called only as a tasklet (software IRQ) */
int hostap_is_sta_assoc(struct ap_data *ap, u8 *sta_addr)
{
    struct sta_info *sta;
    int ret = 0;

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, sta_addr);
    if (sta != NULL && (sta->flags & WLAN_STA_ASSOC) && !sta->ap)
        ret = 1;
    spin_unlock(&ap->sta_table_lock);

    return ret;
}


/* Called only as a tasklet (software IRQ) */
int hostap_is_sta_authorized(struct ap_data *ap, u8 *sta_addr)
{
    struct sta_info *sta;
    int ret = 0;

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, sta_addr);
    if (sta != NULL && (sta->flags & WLAN_STA_ASSOC) && !sta->ap &&
        ((sta->flags & WLAN_STA_AUTHORIZED) ||
         ap->local->ieee_802_1x == 0))
        ret = 1;
    spin_unlock(&ap->sta_table_lock);

    return ret;
}


/* Called only as a tasklet (software IRQ) */
int hostap_add_sta(struct ap_data *ap, u8 *sta_addr)
{
    struct sta_info *sta;
    int ret = 1;

    if (!ap)
        return -1;

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, sta_addr);
    if (sta)
        ret = 0;
    spin_unlock(&ap->sta_table_lock);

    if (ret == 1) {
        sta = ap_add_sta(ap, sta_addr);
        if (!sta)
            return -1;
        sta->flags = WLAN_STA_AUTH | WLAN_STA_ASSOC;
        sta->ap = 1;
        memset(sta->supported_rates, 0, sizeof(sta->supported_rates));
        /* No way of knowing which rates are supported since we did not
         * get supported rates element from beacon/assoc req. Assume
         * that remote end supports all 802.11b rates. */
        sta->supported_rates[0] = 0x82;
        sta->supported_rates[1] = 0x84;
        sta->supported_rates[2] = 0x0b;
        sta->supported_rates[3] = 0x16;
        sta->tx_supp_rates = WLAN_RATE_1M | WLAN_RATE_2M |
            WLAN_RATE_5M5 | WLAN_RATE_11M;
        sta->tx_rate = 110;
        sta->tx_max_rate = sta->tx_rate_idx = 3;
    }

    return ret;
}


/* Called only as a tasklet (software IRQ) */
int hostap_update_rx_stats(struct ap_data *ap,
               struct ieee80211_hdr *hdr,
               struct hostap_80211_rx_status *rx_stats)
{
    struct sta_info *sta;

    if (!ap)
        return -1;

    spin_lock(&ap->sta_table_lock);
    sta = ap_get_sta(ap, hdr->addr2);
    if (sta) {
        sta->last_rx_silence = rx_stats->noise;
        sta->last_rx_signal = rx_stats->signal;
        sta->last_rx_rate = rx_stats->rate;
        sta->last_rx_updated = IW_QUAL_ALL_UPDATED | IW_QUAL_DBM;
        if (rx_stats->rate == 10)
            sta->rx_count[0]++;
        else if (rx_stats->rate == 20)
            sta->rx_count[1]++;
        else if (rx_stats->rate == 55)
            sta->rx_count[2]++;
        else if (rx_stats->rate == 110)
            sta->rx_count[3]++;
    }
    spin_unlock(&ap->sta_table_lock);

    return sta ? 0 : -1;
}


void hostap_update_rates(local_info_t *local)
{
    struct sta_info *sta;
    struct ap_data *ap = local->ap;

    if (!ap)
        return;

    spin_lock_bh(&ap->sta_table_lock);
    list_for_each_entry(sta, &ap->sta_list, list) {
        prism2_check_tx_rates(sta);
    }
    spin_unlock_bh(&ap->sta_table_lock);
}


void * ap_crypt_get_ptrs(struct ap_data *ap, u8 *addr, int permanent,
             struct lib80211_crypt_data ***crypt)
{
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    sta = ap_get_sta(ap, addr);
    if (sta)
        atomic_inc(&sta->users);
    spin_unlock_bh(&ap->sta_table_lock);

    if (!sta && permanent)
        sta = ap_add_sta(ap, addr);

    if (!sta)
        return NULL;

    if (permanent)
        sta->flags |= WLAN_STA_PERM;

    *crypt = &sta->crypt;

    return sta;
}


void hostap_add_wds_links(local_info_t *local)
{
    struct ap_data *ap = local->ap;
    struct sta_info *sta;

    spin_lock_bh(&ap->sta_table_lock);
    list_for_each_entry(sta, &ap->sta_list, list) {
        if (sta->ap)
            hostap_wds_link_oper(local, sta->addr, WDS_ADD);
    }
    spin_unlock_bh(&ap->sta_table_lock);

    schedule_work(&local->ap->wds_oper_queue);
}


void hostap_wds_link_oper(local_info_t *local, u8 *addr, wds_oper_type type)
{
    struct wds_oper_data *entry;

    entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
    if (!entry)
        return;
    memcpy(entry->addr, addr, ETH_ALEN);
    entry->type = type;
    spin_lock_bh(&local->lock);
    entry->next = local->ap->wds_oper_entries;
    local->ap->wds_oper_entries = entry;
    spin_unlock_bh(&local->lock);

    schedule_work(&local->ap->wds_oper_queue);
}


EXPORT_SYMBOL(hostap_init_data);
EXPORT_SYMBOL(hostap_init_ap_proc);
EXPORT_SYMBOL(hostap_free_data);
EXPORT_SYMBOL(hostap_check_sta_fw_version);
EXPORT_SYMBOL(hostap_handle_sta_tx_exc);
#ifndef PRISM2_NO_KERNEL_IEEE80211_MGMT
#endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */