libipw_rx.c

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/*
 * Original code based Host AP (software wireless LAN access point) driver
 * for Intersil Prism2/2.5/3 - hostap.o module, common routines
 *
 * Copyright (c) 2001-2002, SSH Communications Security Corp and Jouni Malinen
 * <[email protected]>
 * Copyright (c) 2002-2003, Jouni Malinen <[email protected]>
 * Copyright (c) 2004-2005, Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */

#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/in6.h>
#include <linux/gfp.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/types.h>
#include <linux/wireless.h>
#include <linux/etherdevice.h>
#include <asm/uaccess.h>
#include <linux/ctype.h>

#include <net/lib80211.h>

#include "libipw.h"

static void libipw_monitor_rx(struct libipw_device *ieee,
                    struct sk_buff *skb,
                    struct libipw_rx_stats *rx_stats)
{
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
    u16 fc = le16_to_cpu(hdr->frame_control);

    skb->dev = ieee->dev;
    skb_reset_mac_header(skb);
    skb_pull(skb, libipw_get_hdrlen(fc));
    skb->pkt_type = PACKET_OTHERHOST;
    skb->protocol = htons(ETH_P_80211_RAW);
    memset(skb->cb, 0, sizeof(skb->cb));
    netif_rx(skb);
}

/* Called only as a tasklet (software IRQ) */
static struct libipw_frag_entry *libipw_frag_cache_find(struct
                                  libipw_device
                                  *ieee,
                                  unsigned int seq,
                                  unsigned int frag,
                                  u8 * src,
                                  u8 * dst)
{
    struct libipw_frag_entry *entry;
    int i;

    for (i = 0; i < LIBIPW_FRAG_CACHE_LEN; i++) {
        entry = &ieee->frag_cache[i];
        if (entry->skb != NULL &&
            time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
            LIBIPW_DEBUG_FRAG("expiring fragment cache entry "
                         "seq=%u last_frag=%u\n",
                         entry->seq, entry->last_frag);
            dev_kfree_skb_any(entry->skb);
            entry->skb = NULL;
        }

        if (entry->skb != NULL && entry->seq == seq &&
            (entry->last_frag + 1 == frag || frag == -1) &&
            ether_addr_equal(entry->src_addr, src) &&
            ether_addr_equal(entry->dst_addr, dst))
            return entry;
    }

    return NULL;
}

/* Called only as a tasklet (software IRQ) */
static struct sk_buff *libipw_frag_cache_get(struct libipw_device *ieee,
                        struct libipw_hdr_4addr *hdr)
{
    struct sk_buff *skb = NULL;
    u16 sc;
    unsigned int frag, seq;
    struct libipw_frag_entry *entry;

    sc = le16_to_cpu(hdr->seq_ctl);
    frag = WLAN_GET_SEQ_FRAG(sc);
    seq = WLAN_GET_SEQ_SEQ(sc);

    if (frag == 0) {
        /* Reserve enough space to fit maximum frame length */
        skb = dev_alloc_skb(ieee->dev->mtu +
                    sizeof(struct libipw_hdr_4addr) +
                    8 /* LLC */  +
                    2 /* alignment */  +
                    8 /* WEP */  + ETH_ALEN /* WDS */ );
        if (skb == NULL)
            return NULL;

        entry = &ieee->frag_cache[ieee->frag_next_idx];
        ieee->frag_next_idx++;
        if (ieee->frag_next_idx >= LIBIPW_FRAG_CACHE_LEN)
            ieee->frag_next_idx = 0;

        if (entry->skb != NULL)
            dev_kfree_skb_any(entry->skb);

        entry->first_frag_time = jiffies;
        entry->seq = seq;
        entry->last_frag = frag;
        entry->skb = skb;
        memcpy(entry->src_addr, hdr->addr2, ETH_ALEN);
        memcpy(entry->dst_addr, hdr->addr1, ETH_ALEN);
    } else {
        /* received a fragment of a frame for which the head fragment
         * should have already been received */
        entry = libipw_frag_cache_find(ieee, seq, frag, hdr->addr2,
                          hdr->addr1);
        if (entry != NULL) {
            entry->last_frag = frag;
            skb = entry->skb;
        }
    }

    return skb;
}

/* Called only as a tasklet (software IRQ) */
static int libipw_frag_cache_invalidate(struct libipw_device *ieee,
                       struct libipw_hdr_4addr *hdr)
{
    u16 sc;
    unsigned int seq;
    struct libipw_frag_entry *entry;

    sc = le16_to_cpu(hdr->seq_ctl);
    seq = WLAN_GET_SEQ_SEQ(sc);

    entry = libipw_frag_cache_find(ieee, seq, -1, hdr->addr2,
                      hdr->addr1);

    if (entry == NULL) {
        LIBIPW_DEBUG_FRAG("could not invalidate fragment cache "
                     "entry (seq=%u)\n", seq);
        return -1;
    }

    entry->skb = NULL;
    return 0;
}

#ifdef NOT_YET
/* libipw_rx_frame_mgtmt
 *
 * Responsible for handling management control frames
 *
 * Called by libipw_rx */
static int
libipw_rx_frame_mgmt(struct libipw_device *ieee, struct sk_buff *skb,
            struct libipw_rx_stats *rx_stats, u16 type,
            u16 stype)
{
    if (ieee->iw_mode == IW_MODE_MASTER) {
        printk(KERN_DEBUG "%s: Master mode not yet supported.\n",
               ieee->dev->name);
        return 0;
/*
  hostap_update_sta_ps(ieee, (struct hostap_libipw_hdr_4addr *)
  skb->data);*/
    }

    if (ieee->hostapd && type == WLAN_FC_TYPE_MGMT) {
        if (stype == WLAN_FC_STYPE_BEACON &&
            ieee->iw_mode == IW_MODE_MASTER) {
            struct sk_buff *skb2;
            /* Process beacon frames also in kernel driver to
             * update STA(AP) table statistics */
            skb2 = skb_clone(skb, GFP_ATOMIC);
            if (skb2)
                hostap_rx(skb2->dev, skb2, rx_stats);
        }

        /* send management frames to the user space daemon for
         * processing */
        ieee->apdevstats.rx_packets++;
        ieee->apdevstats.rx_bytes += skb->len;
        prism2_rx_80211(ieee->apdev, skb, rx_stats, PRISM2_RX_MGMT);
        return 0;
    }

    if (ieee->iw_mode == IW_MODE_MASTER) {
        if (type != WLAN_FC_TYPE_MGMT && type != WLAN_FC_TYPE_CTRL) {
            printk(KERN_DEBUG "%s: unknown management frame "
                   "(type=0x%02x, stype=0x%02x) dropped\n",
                   skb->dev->name, type, stype);
            return -1;
        }

        hostap_rx(skb->dev, skb, rx_stats);
        return 0;
    }

    printk(KERN_DEBUG "%s: hostap_rx_frame_mgmt: management frame "
           "received in non-Host AP mode\n", skb->dev->name);
    return -1;
}
#endif

/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
static unsigned char libipw_rfc1042_header[] =
    { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
static unsigned char libipw_bridge_tunnel_header[] =
    { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
/* No encapsulation header if EtherType < 0x600 (=length) */

/* Called by libipw_rx_frame_decrypt */
static int libipw_is_eapol_frame(struct libipw_device *ieee,
                    struct sk_buff *skb)
{
    struct net_device *dev = ieee->dev;
    u16 fc, ethertype;
    struct libipw_hdr_3addr *hdr;
    u8 *pos;

    if (skb->len < 24)
        return 0;

    hdr = (struct libipw_hdr_3addr *)skb->data;
    fc = le16_to_cpu(hdr->frame_ctl);

    /* check that the frame is unicast frame to us */
    if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
        IEEE80211_FCTL_TODS &&
        ether_addr_equal(hdr->addr1, dev->dev_addr) &&
        ether_addr_equal(hdr->addr3, dev->dev_addr)) {
        /* ToDS frame with own addr BSSID and DA */
    } else if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
           IEEE80211_FCTL_FROMDS &&
           ether_addr_equal(hdr->addr1, dev->dev_addr)) {
        /* FromDS frame with own addr as DA */
    } else
        return 0;

    if (skb->len < 24 + 8)
        return 0;

    /* check for port access entity Ethernet type */
    pos = skb->data + 24;
    ethertype = (pos[6] << 8) | pos[7];
    if (ethertype == ETH_P_PAE)
        return 1;

    return 0;
}

/* Called only as a tasklet (software IRQ), by libipw_rx */
static int
libipw_rx_frame_decrypt(struct libipw_device *ieee, struct sk_buff *skb,
               struct lib80211_crypt_data *crypt)
{
    struct libipw_hdr_3addr *hdr;
    int res, hdrlen;

    if (crypt == NULL || crypt->ops->decrypt_mpdu == NULL)
        return 0;

    hdr = (struct libipw_hdr_3addr *)skb->data;
    hdrlen = libipw_get_hdrlen(le16_to_cpu(hdr->frame_ctl));

    atomic_inc(&crypt->refcnt);
    res = crypt->ops->decrypt_mpdu(skb, hdrlen, crypt->priv);
    atomic_dec(&crypt->refcnt);
    if (res < 0) {
        LIBIPW_DEBUG_DROP("decryption failed (SA=%pM) res=%d\n",
                     hdr->addr2, res);
        if (res == -2)
            LIBIPW_DEBUG_DROP("Decryption failed ICV "
                         "mismatch (key %d)\n",
                         skb->data[hdrlen + 3] >> 6);
        ieee->ieee_stats.rx_discards_undecryptable++;
        return -1;
    }

    return res;
}

/* Called only as a tasklet (software IRQ), by libipw_rx */
static int
libipw_rx_frame_decrypt_msdu(struct libipw_device *ieee,
                struct sk_buff *skb, int keyidx,
                struct lib80211_crypt_data *crypt)
{
    struct libipw_hdr_3addr *hdr;
    int res, hdrlen;

    if (crypt == NULL || crypt->ops->decrypt_msdu == NULL)
        return 0;

    hdr = (struct libipw_hdr_3addr *)skb->data;
    hdrlen = libipw_get_hdrlen(le16_to_cpu(hdr->frame_ctl));

    atomic_inc(&crypt->refcnt);
    res = crypt->ops->decrypt_msdu(skb, keyidx, hdrlen, crypt->priv);
    atomic_dec(&crypt->refcnt);
    if (res < 0) {
        printk(KERN_DEBUG "%s: MSDU decryption/MIC verification failed"
               " (SA=%pM keyidx=%d)\n", ieee->dev->name, hdr->addr2,
               keyidx);
        return -1;
    }

    return 0;
}

/* All received frames are sent to this function. @skb contains the frame in
 * IEEE 802.11 format, i.e., in the format it was sent over air.
 * This function is called only as a tasklet (software IRQ). */
int libipw_rx(struct libipw_device *ieee, struct sk_buff *skb,
         struct libipw_rx_stats *rx_stats)
{
    struct net_device *dev = ieee->dev;
    struct libipw_hdr_4addr *hdr;
    size_t hdrlen;
    u16 fc, type, stype, sc;
    unsigned int frag;
    u8 *payload;
    u16 ethertype;
#ifdef NOT_YET
    struct net_device *wds = NULL;
    struct sk_buff *skb2 = NULL;
    struct net_device *wds = NULL;
    int frame_authorized = 0;
    int from_assoc_ap = 0;
    void *sta = NULL;
#endif
    u8 dst[ETH_ALEN];
    u8 src[ETH_ALEN];
    struct lib80211_crypt_data *crypt = NULL;
    int keyidx = 0;
    int can_be_decrypted = 0;

    hdr = (struct libipw_hdr_4addr *)skb->data;
    if (skb->len < 10) {
        printk(KERN_INFO "%s: SKB length < 10\n", dev->name);
        goto rx_dropped;
    }

    fc = le16_to_cpu(hdr->frame_ctl);
    type = WLAN_FC_GET_TYPE(fc);
    stype = WLAN_FC_GET_STYPE(fc);
    sc = le16_to_cpu(hdr->seq_ctl);
    frag = WLAN_GET_SEQ_FRAG(sc);
    hdrlen = libipw_get_hdrlen(fc);

    if (skb->len < hdrlen) {
        printk(KERN_INFO "%s: invalid SKB length %d\n",
            dev->name, skb->len);
        goto rx_dropped;
    }

    /* Put this code here so that we avoid duplicating it in all
     * Rx paths. - Jean II */
#ifdef CONFIG_WIRELESS_EXT
#ifdef IW_WIRELESS_SPY      /* defined in iw_handler.h */
    /* If spy monitoring on */
    if (ieee->spy_data.spy_number > 0) {
        struct iw_quality wstats;

        wstats.updated = 0;
        if (rx_stats->mask & LIBIPW_STATMASK_RSSI) {
            wstats.level = rx_stats->signal;
            wstats.updated |= IW_QUAL_LEVEL_UPDATED;
        } else
            wstats.updated |= IW_QUAL_LEVEL_INVALID;

        if (rx_stats->mask & LIBIPW_STATMASK_NOISE) {
            wstats.noise = rx_stats->noise;
            wstats.updated |= IW_QUAL_NOISE_UPDATED;
        } else
            wstats.updated |= IW_QUAL_NOISE_INVALID;

        if (rx_stats->mask & LIBIPW_STATMASK_SIGNAL) {
            wstats.qual = rx_stats->signal;
            wstats.updated |= IW_QUAL_QUAL_UPDATED;
        } else
            wstats.updated |= IW_QUAL_QUAL_INVALID;

        /* Update spy records */
        wireless_spy_update(ieee->dev, hdr->addr2, &wstats);
    }
#endif              /* IW_WIRELESS_SPY */
#endif              /* CONFIG_WIRELESS_EXT */

#ifdef NOT_YET
    hostap_update_rx_stats(local->ap, hdr, rx_stats);
#endif

    if (ieee->iw_mode == IW_MODE_MONITOR) {
        dev->stats.rx_packets++;
        dev->stats.rx_bytes += skb->len;
        libipw_monitor_rx(ieee, skb, rx_stats);
        return 1;
    }

    can_be_decrypted = (is_multicast_ether_addr(hdr->addr1) ||
                is_broadcast_ether_addr(hdr->addr2)) ?
        ieee->host_mc_decrypt : ieee->host_decrypt;

    if (can_be_decrypted) {
        if (skb->len >= hdrlen + 3) {
            /* Top two-bits of byte 3 are the key index */
            keyidx = skb->data[hdrlen + 3] >> 6;
        }

        /* ieee->crypt[] is WEP_KEY (4) in length.  Given that keyidx
         * is only allowed 2-bits of storage, no value of keyidx can
         * be provided via above code that would result in keyidx
         * being out of range */
        crypt = ieee->crypt_info.crypt[keyidx];

#ifdef NOT_YET
        sta = NULL;

        /* Use station specific key to override default keys if the
         * receiver address is a unicast address ("individual RA"). If
         * bcrx_sta_key parameter is set, station specific key is used
         * even with broad/multicast targets (this is against IEEE
         * 802.11, but makes it easier to use different keys with
         * stations that do not support WEP key mapping). */

        if (is_unicast_ether_addr(hdr->addr1) || local->bcrx_sta_key)
            (void)hostap_handle_sta_crypto(local, hdr, &crypt,
                               &sta);
#endif

        /* allow NULL decrypt to indicate an station specific override
         * for default encryption */
        if (crypt && (crypt->ops == NULL ||
                  crypt->ops->decrypt_mpdu == NULL))
            crypt = NULL;

        if (!crypt && (fc & IEEE80211_FCTL_PROTECTED)) {
            /* This seems to be triggered by some (multicast?)
             * frames from other than current BSS, so just drop the
             * frames silently instead of filling system log with
             * these reports. */
            LIBIPW_DEBUG_DROP("Decryption failed (not set)"
                         " (SA=%pM)\n", hdr->addr2);
            ieee->ieee_stats.rx_discards_undecryptable++;
            goto rx_dropped;
        }
    }
#ifdef NOT_YET
    if (type != WLAN_FC_TYPE_DATA) {
        if (type == WLAN_FC_TYPE_MGMT && stype == WLAN_FC_STYPE_AUTH &&
            fc & IEEE80211_FCTL_PROTECTED && ieee->host_decrypt &&
            (keyidx = hostap_rx_frame_decrypt(ieee, skb, crypt)) < 0) {
            printk(KERN_DEBUG "%s: failed to decrypt mgmt::auth "
                   "from %pM\n", dev->name, hdr->addr2);
            /* TODO: could inform hostapd about this so that it
             * could send auth failure report */
            goto rx_dropped;
        }

        if (libipw_rx_frame_mgmt(ieee, skb, rx_stats, type, stype))
            goto rx_dropped;
        else
            goto rx_exit;
    }
#endif
    /* drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.29) */
    if (sc == ieee->prev_seq_ctl)
        goto rx_dropped;
    else
        ieee->prev_seq_ctl = sc;

    /* Data frame - extract src/dst addresses */
    if (skb->len < LIBIPW_3ADDR_LEN)
        goto rx_dropped;

    switch (fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
    case IEEE80211_FCTL_FROMDS:
        memcpy(dst, hdr->addr1, ETH_ALEN);
        memcpy(src, hdr->addr3, ETH_ALEN);
        break;
    case IEEE80211_FCTL_TODS:
        memcpy(dst, hdr->addr3, ETH_ALEN);
        memcpy(src, hdr->addr2, ETH_ALEN);
        break;
    case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
        if (skb->len < LIBIPW_4ADDR_LEN)
            goto rx_dropped;
        memcpy(dst, hdr->addr3, ETH_ALEN);
        memcpy(src, hdr->addr4, ETH_ALEN);
        break;
    case 0:
        memcpy(dst, hdr->addr1, ETH_ALEN);
        memcpy(src, hdr->addr2, ETH_ALEN);
        break;
    }

#ifdef NOT_YET
    if (hostap_rx_frame_wds(ieee, hdr, fc, &wds))
        goto rx_dropped;
    if (wds) {
        skb->dev = dev = wds;
        stats = hostap_get_stats(dev);
    }

    if (ieee->iw_mode == IW_MODE_MASTER && !wds &&
        (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
        IEEE80211_FCTL_FROMDS && ieee->stadev &&
        ether_addr_equal(hdr->addr2, ieee->assoc_ap_addr)) {
        /* Frame from BSSID of the AP for which we are a client */
        skb->dev = dev = ieee->stadev;
        stats = hostap_get_stats(dev);
        from_assoc_ap = 1;
    }
#endif

#ifdef NOT_YET
    if ((ieee->iw_mode == IW_MODE_MASTER ||
         ieee->iw_mode == IW_MODE_REPEAT) && !from_assoc_ap) {
        switch (hostap_handle_sta_rx(ieee, dev, skb, rx_stats,
                         wds != NULL)) {
        case AP_RX_CONTINUE_NOT_AUTHORIZED:
            frame_authorized = 0;
            break;
        case AP_RX_CONTINUE:
            frame_authorized = 1;
            break;
        case AP_RX_DROP:
            goto rx_dropped;
        case AP_RX_EXIT:
            goto rx_exit;
        }
    }
#endif

    /* Nullfunc frames may have PS-bit set, so they must be passed to
     * hostap_handle_sta_rx() before being dropped here. */

    stype &= ~IEEE80211_STYPE_QOS_DATA;

    if (stype != IEEE80211_STYPE_DATA &&
        stype != IEEE80211_STYPE_DATA_CFACK &&
        stype != IEEE80211_STYPE_DATA_CFPOLL &&
        stype != IEEE80211_STYPE_DATA_CFACKPOLL) {
        if (stype != IEEE80211_STYPE_NULLFUNC)
            LIBIPW_DEBUG_DROP("RX: dropped data frame "
                         "with no data (type=0x%02x, "
                         "subtype=0x%02x, len=%d)\n",
                         type, stype, skb->len);
        goto rx_dropped;
    }

    /* skb: hdr + (possibly fragmented, possibly encrypted) payload */

    if ((fc & IEEE80211_FCTL_PROTECTED) && can_be_decrypted &&
        (keyidx = libipw_rx_frame_decrypt(ieee, skb, crypt)) < 0)
        goto rx_dropped;

    hdr = (struct libipw_hdr_4addr *)skb->data;

    /* skb: hdr + (possibly fragmented) plaintext payload */
    // PR: FIXME: hostap has additional conditions in the "if" below:
    // ieee->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
    if ((frag != 0) || (fc & IEEE80211_FCTL_MOREFRAGS)) {
        int flen;
        struct sk_buff *frag_skb = libipw_frag_cache_get(ieee, hdr);
        LIBIPW_DEBUG_FRAG("Rx Fragment received (%u)\n", frag);

        if (!frag_skb) {
            LIBIPW_DEBUG(LIBIPW_DL_RX | LIBIPW_DL_FRAG,
                    "Rx cannot get skb from fragment "
                    "cache (morefrag=%d seq=%u frag=%u)\n",
                    (fc & IEEE80211_FCTL_MOREFRAGS) != 0,
                    WLAN_GET_SEQ_SEQ(sc), frag);
            goto rx_dropped;
        }

        flen = skb->len;
        if (frag != 0)
            flen -= hdrlen;

        if (frag_skb->tail + flen > frag_skb->end) {
            printk(KERN_WARNING "%s: host decrypted and "
                   "reassembled frame did not fit skb\n",
                   dev->name);
            libipw_frag_cache_invalidate(ieee, hdr);
            goto rx_dropped;
        }

        if (frag == 0) {
            /* copy first fragment (including full headers) into
             * beginning of the fragment cache skb */
            skb_copy_from_linear_data(skb, skb_put(frag_skb, flen), flen);
        } else {
            /* append frame payload to the end of the fragment
             * cache skb */
            skb_copy_from_linear_data_offset(skb, hdrlen,
                      skb_put(frag_skb, flen), flen);
        }
        dev_kfree_skb_any(skb);
        skb = NULL;

        if (fc & IEEE80211_FCTL_MOREFRAGS) {
            /* more fragments expected - leave the skb in fragment
             * cache for now; it will be delivered to upper layers
             * after all fragments have been received */
            goto rx_exit;
        }

        /* this was the last fragment and the frame will be
         * delivered, so remove skb from fragment cache */
        skb = frag_skb;
        hdr = (struct libipw_hdr_4addr *)skb->data;
        libipw_frag_cache_invalidate(ieee, hdr);
    }

    /* skb: hdr + (possible reassembled) full MSDU payload; possibly still
     * encrypted/authenticated */
    if ((fc & IEEE80211_FCTL_PROTECTED) && can_be_decrypted &&
        libipw_rx_frame_decrypt_msdu(ieee, skb, keyidx, crypt))
        goto rx_dropped;

    hdr = (struct libipw_hdr_4addr *)skb->data;
    if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !ieee->open_wep) {
        if (        /*ieee->ieee802_1x && */
               libipw_is_eapol_frame(ieee, skb)) {
            /* pass unencrypted EAPOL frames even if encryption is
             * configured */
        } else {
            LIBIPW_DEBUG_DROP("encryption configured, but RX "
                         "frame not encrypted (SA=%pM)\n",
                         hdr->addr2);
            goto rx_dropped;
        }
    }

    if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !ieee->open_wep &&
        !libipw_is_eapol_frame(ieee, skb)) {
        LIBIPW_DEBUG_DROP("dropped unencrypted RX data "
                     "frame from %pM (drop_unencrypted=1)\n",
                     hdr->addr2);
        goto rx_dropped;
    }

    /* If the frame was decrypted in hardware, we may need to strip off
     * any security data (IV, ICV, etc) that was left behind */
    if (!can_be_decrypted && (fc & IEEE80211_FCTL_PROTECTED) &&
        ieee->host_strip_iv_icv) {
        int trimlen = 0;

        /* Top two-bits of byte 3 are the key index */
        if (skb->len >= hdrlen + 3)
            keyidx = skb->data[hdrlen + 3] >> 6;

        /* To strip off any security data which appears before the
         * payload, we simply increase hdrlen (as the header gets
         * chopped off immediately below). For the security data which
         * appears after the payload, we use skb_trim. */

        switch (ieee->sec.encode_alg[keyidx]) {
        case SEC_ALG_WEP:
            /* 4 byte IV */
            hdrlen += 4;
            /* 4 byte ICV */
            trimlen = 4;
            break;
        case SEC_ALG_TKIP:
            /* 4 byte IV, 4 byte ExtIV */
            hdrlen += 8;
            /* 8 byte MIC, 4 byte ICV */
            trimlen = 12;
            break;
        case SEC_ALG_CCMP:
            /* 8 byte CCMP header */
            hdrlen += 8;
            /* 8 byte MIC */
            trimlen = 8;
            break;
        }

        if (skb->len < trimlen)
            goto rx_dropped;

        __skb_trim(skb, skb->len - trimlen);

        if (skb->len < hdrlen)
            goto rx_dropped;
    }

    /* skb: hdr + (possible reassembled) full plaintext payload */

    payload = skb->data + hdrlen;
    ethertype = (payload[6] << 8) | payload[7];

#ifdef NOT_YET
    /* If IEEE 802.1X is used, check whether the port is authorized to send
     * the received frame. */
    if (ieee->ieee802_1x && ieee->iw_mode == IW_MODE_MASTER) {
        if (ethertype == ETH_P_PAE) {
            printk(KERN_DEBUG "%s: RX: IEEE 802.1X frame\n",
                   dev->name);
            if (ieee->hostapd && ieee->apdev) {
                /* Send IEEE 802.1X frames to the user
                 * space daemon for processing */
                prism2_rx_80211(ieee->apdev, skb, rx_stats,
                        PRISM2_RX_MGMT);
                ieee->apdevstats.rx_packets++;
                ieee->apdevstats.rx_bytes += skb->len;
                goto rx_exit;
            }
        } else if (!frame_authorized) {
            printk(KERN_DEBUG "%s: dropped frame from "
                   "unauthorized port (IEEE 802.1X): "
                   "ethertype=0x%04x\n", dev->name, ethertype);
            goto rx_dropped;
        }
    }
#endif

    /* convert hdr + possible LLC headers into Ethernet header */
    if (skb->len - hdrlen >= 8 &&
        ((memcmp(payload, libipw_rfc1042_header, SNAP_SIZE) == 0 &&
          ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
         memcmp(payload, libipw_bridge_tunnel_header, SNAP_SIZE) == 0)) {
        /* remove RFC1042 or Bridge-Tunnel encapsulation and
         * replace EtherType */
        skb_pull(skb, hdrlen + SNAP_SIZE);
        memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
        memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
    } else {
        __be16 len;
        /* Leave Ethernet header part of hdr and full payload */
        skb_pull(skb, hdrlen);
        len = htons(skb->len);
        memcpy(skb_push(skb, 2), &len, 2);
        memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
        memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
    }

#ifdef NOT_YET
    if (wds && ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
            IEEE80211_FCTL_TODS) && skb->len >= ETH_HLEN + ETH_ALEN) {
        /* Non-standard frame: get addr4 from its bogus location after
         * the payload */
        skb_copy_to_linear_data_offset(skb, ETH_ALEN,
                           skb->data + skb->len - ETH_ALEN,
                           ETH_ALEN);
        skb_trim(skb, skb->len - ETH_ALEN);
    }
#endif

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

#ifdef NOT_YET
    if (ieee->iw_mode == IW_MODE_MASTER && !wds && ieee->ap->bridge_packets) {
        if (is_multicast_ether_addr(dst)) {
            /* copy multicast frame both to the higher layers and
             * to the wireless media */
            ieee->ap->bridged_multicast++;
            skb2 = skb_clone(skb, GFP_ATOMIC);
            if (skb2 == NULL)
                printk(KERN_DEBUG "%s: skb_clone failed for "
                       "multicast frame\n", dev->name);
        } else if (hostap_is_sta_assoc(ieee->ap, dst)) {
            /* send frame directly to the associated STA using
             * wireless media and not passing to higher layers */
            ieee->ap->bridged_unicast++;
            skb2 = skb;
            skb = NULL;
        }
    }

    if (skb2 != NULL) {
        /* send to wireless media */
        skb2->dev = dev;
        skb2->protocol = htons(ETH_P_802_3);
        skb_reset_mac_header(skb2);
        skb_reset_network_header(skb2);
        /* skb2->network_header += ETH_HLEN; */
        dev_queue_xmit(skb2);
    }
#endif

    if (skb) {
        skb->protocol = eth_type_trans(skb, dev);
        memset(skb->cb, 0, sizeof(skb->cb));
        skb->ip_summed = CHECKSUM_NONE; /* 802.11 crc not sufficient */
        if (netif_rx(skb) == NET_RX_DROP) {
            /* netif_rx always succeeds, but it might drop
             * the packet.  If it drops the packet, we log that
             * in our stats. */
            LIBIPW_DEBUG_DROP
                ("RX: netif_rx dropped the packet\n");
            dev->stats.rx_dropped++;
        }
    }

      rx_exit:
#ifdef NOT_YET
    if (sta)
        hostap_handle_sta_release(sta);
#endif
    return 1;

      rx_dropped:
    dev->stats.rx_dropped++;

    /* Returning 0 indicates to caller that we have not handled the SKB--
     * so it is still allocated and can be used again by underlying
     * hardware as a DMA target */
    return 0;
}

/* Filter out unrelated packets, call libipw_rx[_mgt]
 * This function takes over the skb, it should not be used again after calling
 * this function. */
void libipw_rx_any(struct libipw_device *ieee,
             struct sk_buff *skb, struct libipw_rx_stats *stats)
{
    struct libipw_hdr_4addr *hdr;
    int is_packet_for_us;
    u16 fc;

    if (ieee->iw_mode == IW_MODE_MONITOR) {
        if (!libipw_rx(ieee, skb, stats))
            dev_kfree_skb_irq(skb);
        return;
    }

    if (skb->len < sizeof(struct ieee80211_hdr))
        goto drop_free;

    hdr = (struct libipw_hdr_4addr *)skb->data;
    fc = le16_to_cpu(hdr->frame_ctl);

    if ((fc & IEEE80211_FCTL_VERS) != 0)
        goto drop_free;

    switch (fc & IEEE80211_FCTL_FTYPE) {
    case IEEE80211_FTYPE_MGMT:
        if (skb->len < sizeof(struct libipw_hdr_3addr))
            goto drop_free;
        libipw_rx_mgt(ieee, hdr, stats);
        dev_kfree_skb_irq(skb);
        return;
    case IEEE80211_FTYPE_DATA:
        break;
    case IEEE80211_FTYPE_CTL:
        return;
    default:
        return;
    }

    is_packet_for_us = 0;
    switch (ieee->iw_mode) {
    case IW_MODE_ADHOC:
        /* our BSS and not from/to DS */
        if (memcmp(hdr->addr3, ieee->bssid, ETH_ALEN) == 0)
        if ((fc & (IEEE80211_FCTL_TODS+IEEE80211_FCTL_FROMDS)) == 0) {
            /* promisc: get all */
            if (ieee->dev->flags & IFF_PROMISC)
                is_packet_for_us = 1;
            /* to us */
            else if (memcmp(hdr->addr1, ieee->dev->dev_addr, ETH_ALEN) == 0)
                is_packet_for_us = 1;
            /* mcast */
            else if (is_multicast_ether_addr(hdr->addr1))
                is_packet_for_us = 1;
        }
        break;
    case IW_MODE_INFRA:
        /* our BSS (== from our AP) and from DS */
        if (memcmp(hdr->addr2, ieee->bssid, ETH_ALEN) == 0)
        if ((fc & (IEEE80211_FCTL_TODS+IEEE80211_FCTL_FROMDS)) == IEEE80211_FCTL_FROMDS) {
            /* promisc: get all */
            if (ieee->dev->flags & IFF_PROMISC)
                is_packet_for_us = 1;
            /* to us */
            else if (memcmp(hdr->addr1, ieee->dev->dev_addr, ETH_ALEN) == 0)
                is_packet_for_us = 1;
            /* mcast */
            else if (is_multicast_ether_addr(hdr->addr1)) {
                /* not our own packet bcasted from AP */
                if (memcmp(hdr->addr3, ieee->dev->dev_addr, ETH_ALEN))
                    is_packet_for_us = 1;
            }
        }
        break;
    default:
        /* ? */
        break;
    }

    if (is_packet_for_us)
        if (!libipw_rx(ieee, skb, stats))
            dev_kfree_skb_irq(skb);
    return;

drop_free:
    dev_kfree_skb_irq(skb);
    ieee->dev->stats.rx_dropped++;
}

#define MGMT_FRAME_FIXED_PART_LENGTH        0x24

static u8 qos_oui[QOS_OUI_LEN] = { 0x00, 0x50, 0xF2 };

/*
* Make the structure we read from the beacon packet to have
* the right values
*/
static int libipw_verify_qos_info(struct libipw_qos_information_element
                     *info_element, int sub_type)
{

    if (info_element->qui_subtype != sub_type)
        return -1;
    if (memcmp(info_element->qui, qos_oui, QOS_OUI_LEN))
        return -1;
    if (info_element->qui_type != QOS_OUI_TYPE)
        return -1;
    if (info_element->version != QOS_VERSION_1)
        return -1;

    return 0;
}

/*
 * Parse a QoS parameter element
 */
static int libipw_read_qos_param_element(struct libipw_qos_parameter_info
                        *element_param, struct libipw_info_element
                        *info_element)
{
    int ret = 0;
    u16 size = sizeof(struct libipw_qos_parameter_info) - 2;

    if ((info_element == NULL) || (element_param == NULL))
        return -1;

    if (info_element->id == QOS_ELEMENT_ID && info_element->len == size) {
        memcpy(element_param->info_element.qui, info_element->data,
               info_element->len);
        element_param->info_element.elementID = info_element->id;
        element_param->info_element.length = info_element->len;
    } else
        ret = -1;
    if (ret == 0)
        ret = libipw_verify_qos_info(&element_param->info_element,
                        QOS_OUI_PARAM_SUB_TYPE);
    return ret;
}

/*
 * Parse a QoS information element
 */
static int libipw_read_qos_info_element(struct
                       libipw_qos_information_element
                       *element_info, struct libipw_info_element
                       *info_element)
{
    int ret = 0;
    u16 size = sizeof(struct libipw_qos_information_element) - 2;

    if (element_info == NULL)
        return -1;
    if (info_element == NULL)
        return -1;

    if ((info_element->id == QOS_ELEMENT_ID) && (info_element->len == size)) {
        memcpy(element_info->qui, info_element->data,
               info_element->len);
        element_info->elementID = info_element->id;
        element_info->length = info_element->len;
    } else
        ret = -1;

    if (ret == 0)
        ret = libipw_verify_qos_info(element_info,
                        QOS_OUI_INFO_SUB_TYPE);
    return ret;
}

/*
 * Write QoS parameters from the ac parameters.
 */
static int libipw_qos_convert_ac_to_parameters(struct
                          libipw_qos_parameter_info
                          *param_elm, struct
                          libipw_qos_parameters
                          *qos_param)
{
    int rc = 0;
    int i;
    struct libipw_qos_ac_parameter *ac_params;
    u32 txop;
    u8 cw_min;
    u8 cw_max;

    for (i = 0; i < QOS_QUEUE_NUM; i++) {
        ac_params = &(param_elm->ac_params_record[i]);

        qos_param->aifs[i] = (ac_params->aci_aifsn) & 0x0F;
        qos_param->aifs[i] -= (qos_param->aifs[i] < 2) ? 0 : 2;

        cw_min = ac_params->ecw_min_max & 0x0F;
        qos_param->cw_min[i] = cpu_to_le16((1 << cw_min) - 1);

        cw_max = (ac_params->ecw_min_max & 0xF0) >> 4;
        qos_param->cw_max[i] = cpu_to_le16((1 << cw_max) - 1);

        qos_param->flag[i] =
            (ac_params->aci_aifsn & 0x10) ? 0x01 : 0x00;

        txop = le16_to_cpu(ac_params->tx_op_limit) * 32;
        qos_param->tx_op_limit[i] = cpu_to_le16(txop);
    }
    return rc;
}

/*
 * we have a generic data element which it may contain QoS information or
 * parameters element. check the information element length to decide
 * which type to read
 */
static int libipw_parse_qos_info_param_IE(struct libipw_info_element
                         *info_element,
                         struct libipw_network *network)
{
    int rc = 0;
    struct libipw_qos_parameters *qos_param = NULL;
    struct libipw_qos_information_element qos_info_element;

    rc = libipw_read_qos_info_element(&qos_info_element, info_element);

    if (rc == 0) {
        network->qos_data.param_count = qos_info_element.ac_info & 0x0F;
        network->flags |= NETWORK_HAS_QOS_INFORMATION;
    } else {
        struct libipw_qos_parameter_info param_element;

        rc = libipw_read_qos_param_element(&param_element,
                              info_element);
        if (rc == 0) {
            qos_param = &(network->qos_data.parameters);
            libipw_qos_convert_ac_to_parameters(&param_element,
                                   qos_param);
            network->flags |= NETWORK_HAS_QOS_PARAMETERS;
            network->qos_data.param_count =
                param_element.info_element.ac_info & 0x0F;
        }
    }

    if (rc == 0) {
        LIBIPW_DEBUG_QOS("QoS is supported\n");
        network->qos_data.supported = 1;
    }
    return rc;
}

#ifdef CONFIG_LIBIPW_DEBUG
#define MFIE_STRING(x) case WLAN_EID_ ##x: return #x

static const char *get_info_element_string(u16 id)
{
    switch (id) {
        MFIE_STRING(SSID);
        MFIE_STRING(SUPP_RATES);
        MFIE_STRING(FH_PARAMS);
        MFIE_STRING(DS_PARAMS);
        MFIE_STRING(CF_PARAMS);
        MFIE_STRING(TIM);
        MFIE_STRING(IBSS_PARAMS);
        MFIE_STRING(COUNTRY);
        MFIE_STRING(HP_PARAMS);
        MFIE_STRING(HP_TABLE);
        MFIE_STRING(REQUEST);
        MFIE_STRING(CHALLENGE);
        MFIE_STRING(PWR_CONSTRAINT);
        MFIE_STRING(PWR_CAPABILITY);
        MFIE_STRING(TPC_REQUEST);
        MFIE_STRING(TPC_REPORT);
        MFIE_STRING(SUPPORTED_CHANNELS);
        MFIE_STRING(CHANNEL_SWITCH);
        MFIE_STRING(MEASURE_REQUEST);
        MFIE_STRING(MEASURE_REPORT);
        MFIE_STRING(QUIET);
        MFIE_STRING(IBSS_DFS);
        MFIE_STRING(ERP_INFO);
        MFIE_STRING(RSN);
        MFIE_STRING(EXT_SUPP_RATES);
        MFIE_STRING(GENERIC);
        MFIE_STRING(QOS_PARAMETER);
    default:
        return "UNKNOWN";
    }
}
#endif

static int libipw_parse_info_param(struct libipw_info_element
                      *info_element, u16 length,
                      struct libipw_network *network)
{
    DECLARE_SSID_BUF(ssid);
    u8 i;
#ifdef CONFIG_LIBIPW_DEBUG
    char rates_str[64];
    char *p;
#endif

    while (length >= sizeof(*info_element)) {
        if (sizeof(*info_element) + info_element->len > length) {
            LIBIPW_DEBUG_MGMT("Info elem: parse failed: "
                         "info_element->len + 2 > left : "
                         "info_element->len+2=%zd left=%d, id=%d.\n",
                         info_element->len +
                         sizeof(*info_element),
                         length, info_element->id);
            /* We stop processing but don't return an error here
             * because some misbehaviour APs break this rule. ie.
             * Orinoco AP1000. */
            break;
        }

        switch (info_element->id) {
        case WLAN_EID_SSID:
            network->ssid_len = min(info_element->len,
                        (u8) IW_ESSID_MAX_SIZE);
            memcpy(network->ssid, info_element->data,
                   network->ssid_len);
            if (network->ssid_len < IW_ESSID_MAX_SIZE)
                memset(network->ssid + network->ssid_len, 0,
                       IW_ESSID_MAX_SIZE - network->ssid_len);

            LIBIPW_DEBUG_MGMT("WLAN_EID_SSID: '%s' len=%d.\n",
                         print_ssid(ssid, network->ssid,
                            network->ssid_len),
                         network->ssid_len);
            break;

        case WLAN_EID_SUPP_RATES:
#ifdef CONFIG_LIBIPW_DEBUG
            p = rates_str;
#endif
            network->rates_len = min(info_element->len,
                         MAX_RATES_LENGTH);
            for (i = 0; i < network->rates_len; i++) {
                network->rates[i] = info_element->data[i];
#ifdef CONFIG_LIBIPW_DEBUG
                p += snprintf(p, sizeof(rates_str) -
                          (p - rates_str), "%02X ",
                          network->rates[i]);
#endif
                if (libipw_is_ofdm_rate
                    (info_element->data[i])) {
                    network->flags |= NETWORK_HAS_OFDM;
                    if (info_element->data[i] &
                        LIBIPW_BASIC_RATE_MASK)
                        network->flags &=
                            ~NETWORK_HAS_CCK;
                }
            }

            LIBIPW_DEBUG_MGMT("WLAN_EID_SUPP_RATES: '%s' (%d)\n",
                         rates_str, network->rates_len);
            break;

        case WLAN_EID_EXT_SUPP_RATES:
#ifdef CONFIG_LIBIPW_DEBUG
            p = rates_str;
#endif
            network->rates_ex_len = min(info_element->len,
                            MAX_RATES_EX_LENGTH);
            for (i = 0; i < network->rates_ex_len; i++) {
                network->rates_ex[i] = info_element->data[i];
#ifdef CONFIG_LIBIPW_DEBUG
                p += snprintf(p, sizeof(rates_str) -
                          (p - rates_str), "%02X ",
                          network->rates[i]);
#endif
                if (libipw_is_ofdm_rate
                    (info_element->data[i])) {
                    network->flags |= NETWORK_HAS_OFDM;
                    if (info_element->data[i] &
                        LIBIPW_BASIC_RATE_MASK)
                        network->flags &=
                            ~NETWORK_HAS_CCK;
                }
            }

            LIBIPW_DEBUG_MGMT("WLAN_EID_EXT_SUPP_RATES: '%s' (%d)\n",
                         rates_str, network->rates_ex_len);
            break;

        case WLAN_EID_DS_PARAMS:
            LIBIPW_DEBUG_MGMT("WLAN_EID_DS_PARAMS: %d\n",
                         info_element->data[0]);
            network->channel = info_element->data[0];
            break;

        case WLAN_EID_FH_PARAMS:
            LIBIPW_DEBUG_MGMT("WLAN_EID_FH_PARAMS: ignored\n");
            break;

        case WLAN_EID_CF_PARAMS:
            LIBIPW_DEBUG_MGMT("WLAN_EID_CF_PARAMS: ignored\n");
            break;

        case WLAN_EID_TIM:
            network->tim.tim_count = info_element->data[0];
            network->tim.tim_period = info_element->data[1];
            LIBIPW_DEBUG_MGMT("WLAN_EID_TIM: partially ignored\n");
            break;

        case WLAN_EID_ERP_INFO:
            network->erp_value = info_element->data[0];
            network->flags |= NETWORK_HAS_ERP_VALUE;
            LIBIPW_DEBUG_MGMT("MFIE_TYPE_ERP_SET: %d\n",
                         network->erp_value);
            break;

        case WLAN_EID_IBSS_PARAMS:
            network->atim_window = info_element->data[0];
            LIBIPW_DEBUG_MGMT("WLAN_EID_IBSS_PARAMS: %d\n",
                         network->atim_window);
            break;

        case WLAN_EID_CHALLENGE:
            LIBIPW_DEBUG_MGMT("WLAN_EID_CHALLENGE: ignored\n");
            break;

        case WLAN_EID_GENERIC:
            LIBIPW_DEBUG_MGMT("WLAN_EID_GENERIC: %d bytes\n",
                         info_element->len);
            if (!libipw_parse_qos_info_param_IE(info_element,
                                   network))
                break;

            if (info_element->len >= 4 &&
                info_element->data[0] == 0x00 &&
                info_element->data[1] == 0x50 &&
                info_element->data[2] == 0xf2 &&
                info_element->data[3] == 0x01) {
                network->wpa_ie_len = min(info_element->len + 2,
                              MAX_WPA_IE_LEN);
                memcpy(network->wpa_ie, info_element,
                       network->wpa_ie_len);
            }
            break;

        case WLAN_EID_RSN:
            LIBIPW_DEBUG_MGMT("WLAN_EID_RSN: %d bytes\n",
                         info_element->len);
            network->rsn_ie_len = min(info_element->len + 2,
                          MAX_WPA_IE_LEN);
            memcpy(network->rsn_ie, info_element,
                   network->rsn_ie_len);
            break;

        case WLAN_EID_QOS_PARAMETER:
            printk(KERN_ERR
                   "QoS Error need to parse QOS_PARAMETER IE\n");
            break;
            /* 802.11h */
        case WLAN_EID_PWR_CONSTRAINT:
            network->power_constraint = info_element->data[0];
            network->flags |= NETWORK_HAS_POWER_CONSTRAINT;
            break;

        case WLAN_EID_CHANNEL_SWITCH:
            network->power_constraint = info_element->data[0];
            network->flags |= NETWORK_HAS_CSA;
            break;

        case WLAN_EID_QUIET:
            network->quiet.count = info_element->data[0];
            network->quiet.period = info_element->data[1];
            network->quiet.duration = info_element->data[2];
            network->quiet.offset = info_element->data[3];
            network->flags |= NETWORK_HAS_QUIET;
            break;

        case WLAN_EID_IBSS_DFS:
            if (network->ibss_dfs)
                break;
            network->ibss_dfs = kmemdup(info_element->data,
                            info_element->len,
                            GFP_ATOMIC);
            if (!network->ibss_dfs)
                return 1;
            network->flags |= NETWORK_HAS_IBSS_DFS;
            break;

        case WLAN_EID_TPC_REPORT:
            network->tpc_report.transmit_power =
                info_element->data[0];
            network->tpc_report.link_margin = info_element->data[1];
            network->flags |= NETWORK_HAS_TPC_REPORT;
            break;

        default:
            LIBIPW_DEBUG_MGMT
                ("Unsupported info element: %s (%d)\n",
                 get_info_element_string(info_element->id),
                 info_element->id);
            break;
        }

        length -= sizeof(*info_element) + info_element->len;
        info_element =
            (struct libipw_info_element *)&info_element->
            data[info_element->len];
    }

    return 0;
}

static int libipw_handle_assoc_resp(struct libipw_device *ieee, struct libipw_assoc_response
                       *frame, struct libipw_rx_stats *stats)
{
    struct libipw_network network_resp = {
        .ibss_dfs = NULL,
    };
    struct libipw_network *network = &network_resp;
    struct net_device *dev = ieee->dev;

    network->flags = 0;
    network->qos_data.active = 0;
    network->qos_data.supported = 0;
    network->qos_data.param_count = 0;
    network->qos_data.old_param_count = 0;

    //network->atim_window = le16_to_cpu(frame->aid) & (0x3FFF);
    network->atim_window = le16_to_cpu(frame->aid);
    network->listen_interval = le16_to_cpu(frame->status);
    memcpy(network->bssid, frame->header.addr3, ETH_ALEN);
    network->capability = le16_to_cpu(frame->capability);
    network->last_scanned = jiffies;
    network->rates_len = network->rates_ex_len = 0;
    network->last_associate = 0;
    network->ssid_len = 0;
    network->erp_value =
        (network->capability & WLAN_CAPABILITY_IBSS) ? 0x3 : 0x0;

    if (stats->freq == LIBIPW_52GHZ_BAND) {
        /* for A band (No DS info) */
        network->channel = stats->received_channel;
    } else
        network->flags |= NETWORK_HAS_CCK;

    network->wpa_ie_len = 0;
    network->rsn_ie_len = 0;

    if (libipw_parse_info_param
        (frame->info_element, stats->len - sizeof(*frame), network))
        return 1;

    network->mode = 0;
    if (stats->freq == LIBIPW_52GHZ_BAND)
        network->mode = IEEE_A;
    else {
        if (network->flags & NETWORK_HAS_OFDM)
            network->mode |= IEEE_G;
        if (network->flags & NETWORK_HAS_CCK)
            network->mode |= IEEE_B;
    }

    memcpy(&network->stats, stats, sizeof(network->stats));

    if (ieee->handle_assoc_response != NULL)
        ieee->handle_assoc_response(dev, frame, network);

    return 0;
}

/***************************************************/

static int libipw_network_init(struct libipw_device *ieee, struct libipw_probe_response
                     *beacon,
                     struct libipw_network *network,
                     struct libipw_rx_stats *stats)
{
    DECLARE_SSID_BUF(ssid);

    network->qos_data.active = 0;
    network->qos_data.supported = 0;
    network->qos_data.param_count = 0;
    network->qos_data.old_param_count = 0;

    /* Pull out fixed field data */
    memcpy(network->bssid, beacon->header.addr3, ETH_ALEN);
    network->capability = le16_to_cpu(beacon->capability);
    network->last_scanned = jiffies;
    network->time_stamp[0] = le32_to_cpu(beacon->time_stamp[0]);
    network->time_stamp[1] = le32_to_cpu(beacon->time_stamp[1]);
    network->beacon_interval = le16_to_cpu(beacon->beacon_interval);
    /* Where to pull this? beacon->listen_interval; */
    network->listen_interval = 0x0A;
    network->rates_len = network->rates_ex_len = 0;
    network->last_associate = 0;
    network->ssid_len = 0;
    network->flags = 0;
    network->atim_window = 0;
    network->erp_value = (network->capability & WLAN_CAPABILITY_IBSS) ?
        0x3 : 0x0;

    if (stats->freq == LIBIPW_52GHZ_BAND) {
        /* for A band (No DS info) */
        network->channel = stats->received_channel;
    } else
        network->flags |= NETWORK_HAS_CCK;

    network->wpa_ie_len = 0;
    network->rsn_ie_len = 0;

    if (libipw_parse_info_param
        (beacon->info_element, stats->len - sizeof(*beacon), network))
        return 1;

    network->mode = 0;
    if (stats->freq == LIBIPW_52GHZ_BAND)
        network->mode = IEEE_A;
    else {
        if (network->flags & NETWORK_HAS_OFDM)
            network->mode |= IEEE_G;
        if (network->flags & NETWORK_HAS_CCK)
            network->mode |= IEEE_B;
    }

    if (network->mode == 0) {
        LIBIPW_DEBUG_SCAN("Filtered out '%s (%pM)' "
                     "network.\n",
                     print_ssid(ssid, network->ssid,
                         network->ssid_len),
                     network->bssid);
        return 1;
    }

    memcpy(&network->stats, stats, sizeof(network->stats));

    return 0;
}

static inline int is_same_network(struct libipw_network *src,
                  struct libipw_network *dst)
{
    /* A network is only a duplicate if the channel, BSSID, and ESSID
     * all match.  We treat all <hidden> with the same BSSID and channel
     * as one network */
    return ((src->ssid_len == dst->ssid_len) &&
        (src->channel == dst->channel) &&
        ether_addr_equal(src->bssid, dst->bssid) &&
        !memcmp(src->ssid, dst->ssid, src->ssid_len));
}

static void update_network(struct libipw_network *dst,
                  struct libipw_network *src)
{
    int qos_active;
    u8 old_param;

    libipw_network_reset(dst);
    dst->ibss_dfs = src->ibss_dfs;

    /* We only update the statistics if they were created by receiving
     * the network information on the actual channel the network is on.
     *
     * This keeps beacons received on neighbor channels from bringing
     * down the signal level of an AP. */
    if (dst->channel == src->stats.received_channel)
        memcpy(&dst->stats, &src->stats,
               sizeof(struct libipw_rx_stats));
    else
        LIBIPW_DEBUG_SCAN("Network %pM info received "
            "off channel (%d vs. %d)\n", src->bssid,
            dst->channel, src->stats.received_channel);

    dst->capability = src->capability;
    memcpy(dst->rates, src->rates, src->rates_len);
    dst->rates_len = src->rates_len;
    memcpy(dst->rates_ex, src->rates_ex, src->rates_ex_len);
    dst->rates_ex_len = src->rates_ex_len;

    dst->mode = src->mode;
    dst->flags = src->flags;
    dst->time_stamp[0] = src->time_stamp[0];
    dst->time_stamp[1] = src->time_stamp[1];

    dst->beacon_interval = src->beacon_interval;
    dst->listen_interval = src->listen_interval;
    dst->atim_window = src->atim_window;
    dst->erp_value = src->erp_value;
    dst->tim = src->tim;

    memcpy(dst->wpa_ie, src->wpa_ie, src->wpa_ie_len);
    dst->wpa_ie_len = src->wpa_ie_len;
    memcpy(dst->rsn_ie, src->rsn_ie, src->rsn_ie_len);
    dst->rsn_ie_len = src->rsn_ie_len;

    dst->last_scanned = jiffies;
    qos_active = src->qos_data.active;
    old_param = dst->qos_data.old_param_count;
    if (dst->flags & NETWORK_HAS_QOS_MASK)
        memcpy(&dst->qos_data, &src->qos_data,
               sizeof(struct libipw_qos_data));
    else {
        dst->qos_data.supported = src->qos_data.supported;
        dst->qos_data.param_count = src->qos_data.param_count;
    }

    if (dst->qos_data.supported == 1) {
        if (dst->ssid_len)
            LIBIPW_DEBUG_QOS
                ("QoS the network %s is QoS supported\n",
                 dst->ssid);
        else
            LIBIPW_DEBUG_QOS
                ("QoS the network is QoS supported\n");
    }
    dst->qos_data.active = qos_active;
    dst->qos_data.old_param_count = old_param;

    /* dst->last_associate is not overwritten */
}

static inline int is_beacon(__le16 fc)
{
    return (WLAN_FC_GET_STYPE(le16_to_cpu(fc)) == IEEE80211_STYPE_BEACON);
}

static void libipw_process_probe_response(struct libipw_device
                            *ieee, struct
                            libipw_probe_response
                            *beacon, struct libipw_rx_stats
                            *stats)
{
    struct net_device *dev = ieee->dev;
    struct libipw_network network = {
        .ibss_dfs = NULL,
    };
    struct libipw_network *target;
    struct libipw_network *oldest = NULL;
#ifdef CONFIG_LIBIPW_DEBUG
    struct libipw_info_element *info_element = beacon->info_element;
#endif
    unsigned long flags;
    DECLARE_SSID_BUF(ssid);

    LIBIPW_DEBUG_SCAN("'%s' (%pM"
             "): %c%c%c%c %c%c%c%c-%c%c%c%c %c%c%c%c\n",
             print_ssid(ssid, info_element->data, info_element->len),
             beacon->header.addr3,
             (beacon->capability & cpu_to_le16(1 << 0xf)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0xe)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0xd)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0xc)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0xb)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0xa)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x9)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x8)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x7)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x6)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x5)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x4)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x3)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x2)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x1)) ? '1' : '0',
             (beacon->capability & cpu_to_le16(1 << 0x0)) ? '1' : '0');

    if (libipw_network_init(ieee, beacon, &network, stats)) {
        LIBIPW_DEBUG_SCAN("Dropped '%s' (%pM) via %s.\n",
                     print_ssid(ssid, info_element->data,
                         info_element->len),
                     beacon->header.addr3,
                     is_beacon(beacon->header.frame_ctl) ?
                     "BEACON" : "PROBE RESPONSE");
        return;
    }

    /* The network parsed correctly -- so now we scan our known networks
     * to see if we can find it in our list.
     *
     * NOTE:  This search is definitely not optimized.  Once its doing
     *        the "right thing" we'll optimize it for efficiency if
     *        necessary */

    /* Search for this entry in the list and update it if it is
     * already there. */

    spin_lock_irqsave(&ieee->lock, flags);

    list_for_each_entry(target, &ieee->network_list, list) {
        if (is_same_network(target, &network))
            break;

        if ((oldest == NULL) ||
            time_before(target->last_scanned, oldest->last_scanned))
            oldest = target;
    }

    /* If we didn't find a match, then get a new network slot to initialize
     * with this beacon's information */
    if (&target->list == &ieee->network_list) {
        if (list_empty(&ieee->network_free_list)) {
            /* If there are no more slots, expire the oldest */
            list_del(&oldest->list);
            target = oldest;
            LIBIPW_DEBUG_SCAN("Expired '%s' (%pM) from "
                         "network list.\n",
                         print_ssid(ssid, target->ssid,
                             target->ssid_len),
                         target->bssid);
            libipw_network_reset(target);
        } else {
            /* Otherwise just pull from the free list */
            target = list_entry(ieee->network_free_list.next,
                        struct libipw_network, list);
            list_del(ieee->network_free_list.next);
        }

#ifdef CONFIG_LIBIPW_DEBUG
        LIBIPW_DEBUG_SCAN("Adding '%s' (%pM) via %s.\n",
                     print_ssid(ssid, network.ssid,
                         network.ssid_len),
                     network.bssid,
                     is_beacon(beacon->header.frame_ctl) ?
                     "BEACON" : "PROBE RESPONSE");
#endif
        memcpy(target, &network, sizeof(*target));
        network.ibss_dfs = NULL;
        list_add_tail(&target->list, &ieee->network_list);
    } else {
        LIBIPW_DEBUG_SCAN("Updating '%s' (%pM) via %s.\n",
                     print_ssid(ssid, target->ssid,
                         target->ssid_len),
                     target->bssid,
                     is_beacon(beacon->header.frame_ctl) ?
                     "BEACON" : "PROBE RESPONSE");
        update_network(target, &network);
        network.ibss_dfs = NULL;
    }

    spin_unlock_irqrestore(&ieee->lock, flags);

    if (is_beacon(beacon->header.frame_ctl)) {
        if (ieee->handle_beacon != NULL)
            ieee->handle_beacon(dev, beacon, target);
    } else {
        if (ieee->handle_probe_response != NULL)
            ieee->handle_probe_response(dev, beacon, target);
    }
}

void libipw_rx_mgt(struct libipw_device *ieee,
              struct libipw_hdr_4addr *header,
              struct libipw_rx_stats *stats)
{
    switch (WLAN_FC_GET_STYPE(le16_to_cpu(header->frame_ctl))) {
    case IEEE80211_STYPE_ASSOC_RESP:
        LIBIPW_DEBUG_MGMT("received ASSOCIATION RESPONSE (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        libipw_handle_assoc_resp(ieee,
                        (struct libipw_assoc_response *)
                        header, stats);
        break;

    case IEEE80211_STYPE_REASSOC_RESP:
        LIBIPW_DEBUG_MGMT("received REASSOCIATION RESPONSE (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        break;

    case IEEE80211_STYPE_PROBE_REQ:
        LIBIPW_DEBUG_MGMT("received auth (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));

        if (ieee->handle_probe_request != NULL)
            ieee->handle_probe_request(ieee->dev,
                           (struct
                            libipw_probe_request *)
                           header, stats);
        break;

    case IEEE80211_STYPE_PROBE_RESP:
        LIBIPW_DEBUG_MGMT("received PROBE RESPONSE (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        LIBIPW_DEBUG_SCAN("Probe response\n");
        libipw_process_probe_response(ieee,
                         (struct
                          libipw_probe_response *)
                         header, stats);
        break;

    case IEEE80211_STYPE_BEACON:
        LIBIPW_DEBUG_MGMT("received BEACON (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        LIBIPW_DEBUG_SCAN("Beacon\n");
        libipw_process_probe_response(ieee,
                         (struct
                          libipw_probe_response *)
                         header, stats);
        break;
    case IEEE80211_STYPE_AUTH:

        LIBIPW_DEBUG_MGMT("received auth (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));

        if (ieee->handle_auth != NULL)
            ieee->handle_auth(ieee->dev,
                      (struct libipw_auth *)header);
        break;

    case IEEE80211_STYPE_DISASSOC:
        if (ieee->handle_disassoc != NULL)
            ieee->handle_disassoc(ieee->dev,
                          (struct libipw_disassoc *)
                          header);
        break;

    case IEEE80211_STYPE_ACTION:
        LIBIPW_DEBUG_MGMT("ACTION\n");
        if (ieee->handle_action)
            ieee->handle_action(ieee->dev,
                        (struct libipw_action *)
                        header, stats);
        break;

    case IEEE80211_STYPE_REASSOC_REQ:
        LIBIPW_DEBUG_MGMT("received reassoc (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));

        LIBIPW_DEBUG_MGMT("%s: LIBIPW_REASSOC_REQ received\n",
                     ieee->dev->name);
        if (ieee->handle_reassoc_request != NULL)
            ieee->handle_reassoc_request(ieee->dev,
                            (struct libipw_reassoc_request *)
                             header);
        break;

    case IEEE80211_STYPE_ASSOC_REQ:
        LIBIPW_DEBUG_MGMT("received assoc (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));

        LIBIPW_DEBUG_MGMT("%s: LIBIPW_ASSOC_REQ received\n",
                     ieee->dev->name);
        if (ieee->handle_assoc_request != NULL)
            ieee->handle_assoc_request(ieee->dev);
        break;

    case IEEE80211_STYPE_DEAUTH:
        LIBIPW_DEBUG_MGMT("DEAUTH\n");
        if (ieee->handle_deauth != NULL)
            ieee->handle_deauth(ieee->dev,
                        (struct libipw_deauth *)
                        header);
        break;
    default:
        LIBIPW_DEBUG_MGMT("received UNKNOWN (%d)\n",
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        LIBIPW_DEBUG_MGMT("%s: Unknown management packet: %d\n",
                     ieee->dev->name,
                     WLAN_FC_GET_STYPE(le16_to_cpu
                               (header->frame_ctl)));
        break;
    }
}

EXPORT_SYMBOL_GPL(libipw_rx_any);
EXPORT_SYMBOL(libipw_rx_mgt);
EXPORT_SYMBOL(libipw_rx);