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ieee80211_rx.c

/*
 * 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
 * <j@w1.fi>
 * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
 * 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/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/slab.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/ieee80211.h>

static void ieee80211_monitor_rx(struct ieee80211_device *ieee,
                              struct sk_buff *skb,
                              struct ieee80211_rx_stats *rx_stats)
{
      struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
      u16 fc = le16_to_cpu(hdr->frame_ctl);

      skb->dev = ieee->dev;
      skb_reset_mac_header(skb);
      skb_pull(skb, ieee80211_get_hdrlen(fc));
      skb->pkt_type = PACKET_OTHERHOST;
      skb->protocol = __constant_htons(ETH_P_80211_RAW);
      memset(skb->cb, 0, sizeof(skb->cb));
      netif_rx(skb);
}

/* Called only as a tasklet (software IRQ) */
static struct ieee80211_frag_entry *ieee80211_frag_cache_find(struct
                                                ieee80211_device
                                                *ieee,
                                                unsigned int seq,
                                                unsigned int frag,
                                                u8 * src,
                                                u8 * dst)
{
      struct ieee80211_frag_entry *entry;
      int i;

      for (i = 0; i < IEEE80211_FRAG_CACHE_LEN; i++) {
            entry = &ieee->frag_cache[i];
            if (entry->skb != NULL &&
                time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
                  IEEE80211_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) &&
                !compare_ether_addr(entry->src_addr, src) &&
                !compare_ether_addr(entry->dst_addr, dst))
                  return entry;
      }

      return NULL;
}

/* Called only as a tasklet (software IRQ) */
static struct sk_buff *ieee80211_frag_cache_get(struct ieee80211_device *ieee,
                                    struct ieee80211_hdr_4addr *hdr)
{
      struct sk_buff *skb = NULL;
      u16 sc;
      unsigned int frag, seq;
      struct ieee80211_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 ieee80211_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 >= IEEE80211_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 = ieee80211_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 ieee80211_frag_cache_invalidate(struct ieee80211_device *ieee,
                                 struct ieee80211_hdr_4addr *hdr)
{
      u16 sc;
      unsigned int seq;
      struct ieee80211_frag_entry *entry;

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

      entry = ieee80211_frag_cache_find(ieee, seq, -1, hdr->addr2,
                                hdr->addr1);

      if (entry == NULL) {
            IEEE80211_DEBUG_FRAG("could not invalidate fragment cache "
                             "entry (seq=%u)\n", seq);
            return -1;
      }

      entry->skb = NULL;
      return 0;
}

#ifdef NOT_YET
/* ieee80211_rx_frame_mgtmt
 *
 * Responsible for handling management control frames
 *
 * Called by ieee80211_rx */
static int
ieee80211_rx_frame_mgmt(struct ieee80211_device *ieee, struct sk_buff *skb,
                  struct ieee80211_rx_stats *rx_stats, u16 type,
                  u16 stype)
{
      if (ieee->iw_mode == IW_MODE_MASTER) {
            printk(KERN_DEBUG "%s: Master mode not yet suppported.\n",
                   ieee->dev->name);
            return 0;
/*
  hostap_update_sta_ps(ieee, (struct hostap_ieee80211_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 rfc1042_header[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

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

/* Called by ieee80211_rx_frame_decrypt */
static int ieee80211_is_eapol_frame(struct ieee80211_device *ieee,
                            struct sk_buff *skb)
{
      struct net_device *dev = ieee->dev;
      u16 fc, ethertype;
      struct ieee80211_hdr_3addr *hdr;
      u8 *pos;

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

      hdr = (struct ieee80211_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 &&
          !compare_ether_addr(hdr->addr1, dev->dev_addr) &&
          !compare_ether_addr(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 &&
               !compare_ether_addr(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 ieee80211_rx */
static int
ieee80211_rx_frame_decrypt(struct ieee80211_device *ieee, struct sk_buff *skb,
                     struct ieee80211_crypt_data *crypt)
{
      struct ieee80211_hdr_3addr *hdr;
      int res, hdrlen;
      DECLARE_MAC_BUF(mac);

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

      hdr = (struct ieee80211_hdr_3addr *)skb->data;
      hdrlen = ieee80211_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) {
            IEEE80211_DEBUG_DROP("decryption failed (SA=%s"
                             ") res=%d\n", print_mac(mac, hdr->addr2), res);
            if (res == -2)
                  IEEE80211_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 ieee80211_rx */
static int
ieee80211_rx_frame_decrypt_msdu(struct ieee80211_device *ieee,
                        struct sk_buff *skb, int keyidx,
                        struct ieee80211_crypt_data *crypt)
{
      struct ieee80211_hdr_3addr *hdr;
      int res, hdrlen;
      DECLARE_MAC_BUF(mac);

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

      hdr = (struct ieee80211_hdr_3addr *)skb->data;
      hdrlen = ieee80211_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=%s keyidx=%d)\n",
                   ieee->dev->name, print_mac(mac, 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 ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
             struct ieee80211_rx_stats *rx_stats)
{
      struct net_device *dev = ieee->dev;
      struct ieee80211_hdr_4addr *hdr;
      size_t hdrlen;
      u16 fc, type, stype, sc;
      struct net_device_stats *stats;
      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 ieee80211_crypt_data *crypt = NULL;
      int keyidx = 0;
      int can_be_decrypted = 0;
      DECLARE_MAC_BUF(mac);

      hdr = (struct ieee80211_hdr_4addr *)skb->data;
      stats = &ieee->stats;

      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 = ieee80211_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 & IEEE80211_STATMASK_RSSI) {
                  wstats.level = rx_stats->rssi;
                  wstats.updated |= IW_QUAL_LEVEL_UPDATED;
            } else
                  wstats.updated |= IW_QUAL_LEVEL_INVALID;

            if (rx_stats->mask & IEEE80211_STATMASK_NOISE) {
                  wstats.noise = rx_stats->noise;
                  wstats.updated |= IW_QUAL_NOISE_UPDATED;
            } else
                  wstats.updated |= IW_QUAL_NOISE_INVALID;

            if (rx_stats->mask & IEEE80211_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) {
            stats->rx_packets++;
            stats->rx_bytes += skb->len;
            ieee80211_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[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 (!(hdr->addr1[0] & 0x01) || 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. */
                  IEEE80211_DEBUG_DROP("Decryption failed (not set)"
                                   " (SA=%s)\n",
                                   print_mac(mac, 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 %s\n", dev->name,
                         print_mac(mac, hdr->addr2));
                  /* TODO: could inform hostapd about this so that it
                   * could send auth failure report */
                  goto rx_dropped;
            }

            if (ieee80211_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 < IEEE80211_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 < IEEE80211_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
          && !compare_ether_addr(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

      dev->last_rx = jiffies;

#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)
                  IEEE80211_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 = ieee80211_rx_frame_decrypt(ieee, skb, crypt)) < 0)
            goto rx_dropped;

      hdr = (struct ieee80211_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 = ieee80211_frag_cache_get(ieee, hdr);
            IEEE80211_DEBUG_FRAG("Rx Fragment received (%u)\n", frag);

            if (!frag_skb) {
                  IEEE80211_DEBUG(IEEE80211_DL_RX | IEEE80211_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);
                  ieee80211_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 ieee80211_hdr_4addr *)skb->data;
            ieee80211_frag_cache_invalidate(ieee, hdr);
      }

      /* skb: hdr + (possible reassembled) full MSDU payload; possibly still
       * encrypted/authenticated */
      if ((fc & IEEE80211_FCTL_PROTECTED) && can_be_decrypted &&
          ieee80211_rx_frame_decrypt_msdu(ieee, skb, keyidx, crypt))
            goto rx_dropped;

      hdr = (struct ieee80211_hdr_4addr *)skb->data;
      if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !ieee->open_wep) {
            if (        /*ieee->ieee802_1x && */
                     ieee80211_is_eapol_frame(ieee, skb)) {
                  /* pass unencrypted EAPOL frames even if encryption is
                   * configured */
            } else {
                  IEEE80211_DEBUG_DROP("encryption configured, but RX "
                                   "frame not encrypted (SA=%s"
                                   ")\n", print_mac(mac, hdr->addr2));
                  goto rx_dropped;
            }
      }

      if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !ieee->open_wep &&
          !ieee80211_is_eapol_frame(ieee, skb)) {
            IEEE80211_DEBUG_DROP("dropped unencrypted RX data "
                             "frame from %s"
                             " (drop_unencrypted=1)\n",
                             print_mac(mac, 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, rfc1042_header, SNAP_SIZE) == 0 &&
            ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
           memcmp(payload, 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 {
            u16 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

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

#ifdef NOT_YET
      if (ieee->iw_mode == IW_MODE_MASTER && !wds && ieee->ap->bridge_packets) {
            if (dst[0] & 0x01) {
                  /* 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 = __constant_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. */
                  IEEE80211_DEBUG_DROP
                      ("RX: netif_rx dropped the packet\n");
                  stats->rx_dropped++;
            }
      }

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

      rx_dropped:
      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 ieee80211_rx[_mgt]
 * This function takes over the skb, it should not be used again after calling
 * this function. */
void ieee80211_rx_any(struct ieee80211_device *ieee,
                 struct sk_buff *skb, struct ieee80211_rx_stats *stats)
{
      struct ieee80211_hdr_4addr *hdr;
      int is_packet_for_us;
      u16 fc;

      if (ieee->iw_mode == IW_MODE_MONITOR) {
            if (!ieee80211_rx(ieee, skb, stats))
                  dev_kfree_skb_irq(skb);
            return;
      }

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

      hdr = (struct ieee80211_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 ieee80211_hdr_3addr))
                  goto drop_free;
            ieee80211_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 (!ieee80211_rx(ieee, skb, stats))
                  dev_kfree_skb_irq(skb);
      return;

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

#define MGMT_FRAME_FIXED_PART_LENGTH            0x24

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

/*
* Make ther structure we read from the beacon packet has
* the right values
*/
static int ieee80211_verify_qos_info(struct ieee80211_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 ieee80211_read_qos_param_element(struct ieee80211_qos_parameter_info
                                  *element_param, struct ieee80211_info_element
                                  *info_element)
{
      int ret = 0;
      u16 size = sizeof(struct ieee80211_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 = ieee80211_verify_qos_info(&element_param->info_element,
                                    QOS_OUI_PARAM_SUB_TYPE);
      return ret;
}

/*
 * Parse a QoS information element
 */
static int ieee80211_read_qos_info_element(struct
                                 ieee80211_qos_information_element
                                 *element_info, struct ieee80211_info_element
                                 *info_element)
{
      int ret = 0;
      u16 size = sizeof(struct ieee80211_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 = ieee80211_verify_qos_info(element_info,
                                    QOS_OUI_INFO_SUB_TYPE);
      return ret;
}

/*
 * Write QoS parameters from the ac parameters.
 */
static int ieee80211_qos_convert_ac_to_parameters(struct
                                      ieee80211_qos_parameter_info
                                      *param_elm, struct
                                      ieee80211_qos_parameters
                                      *qos_param)
{
      int rc = 0;
      int i;
      struct ieee80211_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] = (u16) ((1 << cw_min) - 1);

            cw_max = (ac_params->ecw_min_max & 0xF0) >> 4;
            qos_param->cw_max[i] = (u16) ((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] = (u16) 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 ieee80211_parse_qos_info_param_IE(struct ieee80211_info_element
                                   *info_element,
                                   struct ieee80211_network *network)
{
      int rc = 0;
      struct ieee80211_qos_parameters *qos_param = NULL;
      struct ieee80211_qos_information_element qos_info_element;

      rc = ieee80211_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 ieee80211_qos_parameter_info param_element;

            rc = ieee80211_read_qos_param_element(&param_element,
                                          info_element);
            if (rc == 0) {
                  qos_param = &(network->qos_data.parameters);
                  ieee80211_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) {
            IEEE80211_DEBUG_QOS("QoS is supported\n");
            network->qos_data.supported = 1;
      }
      return rc;
}

#ifdef CONFIG_IEEE80211_DEBUG
#define MFIE_STRING(x) case MFIE_TYPE_ ##x: return #x

static const char *get_info_element_string(u16 id)
{
      switch (id) {
            MFIE_STRING(SSID);
            MFIE_STRING(RATES);
            MFIE_STRING(FH_SET);
            MFIE_STRING(DS_SET);
            MFIE_STRING(CF_SET);
            MFIE_STRING(TIM);
            MFIE_STRING(IBSS_SET);
            MFIE_STRING(COUNTRY);
            MFIE_STRING(HOP_PARAMS);
            MFIE_STRING(HOP_TABLE);
            MFIE_STRING(REQUEST);
            MFIE_STRING(CHALLENGE);
            MFIE_STRING(POWER_CONSTRAINT);
            MFIE_STRING(POWER_CAPABILITY);
            MFIE_STRING(TPC_REQUEST);
            MFIE_STRING(TPC_REPORT);
            MFIE_STRING(SUPP_CHANNELS);
            MFIE_STRING(CSA);
            MFIE_STRING(MEASURE_REQUEST);
            MFIE_STRING(MEASURE_REPORT);
            MFIE_STRING(QUIET);
            MFIE_STRING(IBSS_DFS);
            MFIE_STRING(ERP_INFO);
            MFIE_STRING(RSN);
            MFIE_STRING(RATES_EX);
            MFIE_STRING(GENERIC);
            MFIE_STRING(QOS_PARAMETER);
      default:
            return "UNKNOWN";
      }
}
#endif

static int ieee80211_parse_info_param(struct ieee80211_info_element
                              *info_element, u16 length,
                              struct ieee80211_network *network)
{
      u8 i;
#ifdef CONFIG_IEEE80211_DEBUG
      char rates_str[64];
      char *p;
#endif

      while (length >= sizeof(*info_element)) {
            if (sizeof(*info_element) + info_element->len > length) {
                  IEEE80211_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 MFIE_TYPE_SSID:
                  if (ieee80211_is_empty_essid(info_element->data,
                                         info_element->len)) {
                        network->flags |= NETWORK_EMPTY_ESSID;
                        break;
                  }

                  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);

                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_SSID: '%s' len=%d.\n",
                                   network->ssid, network->ssid_len);
                  break;

            case MFIE_TYPE_RATES:
#ifdef CONFIG_IEEE80211_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_IEEE80211_DEBUG
                        p += snprintf(p, sizeof(rates_str) -
                                    (p - rates_str), "%02X ",
                                    network->rates[i]);
#endif
                        if (ieee80211_is_ofdm_rate
                            (info_element->data[i])) {
                              network->flags |= NETWORK_HAS_OFDM;
                              if (info_element->data[i] &
                                  IEEE80211_BASIC_RATE_MASK)
                                    network->flags &=
                                        ~NETWORK_HAS_CCK;
                        }
                  }

                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_RATES: '%s' (%d)\n",
                                   rates_str, network->rates_len);
                  break;

            case MFIE_TYPE_RATES_EX:
#ifdef CONFIG_IEEE80211_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_IEEE80211_DEBUG
                        p += snprintf(p, sizeof(rates_str) -
                                    (p - rates_str), "%02X ",
                                    network->rates[i]);
#endif
                        if (ieee80211_is_ofdm_rate
                            (info_element->data[i])) {
                              network->flags |= NETWORK_HAS_OFDM;
                              if (info_element->data[i] &
                                  IEEE80211_BASIC_RATE_MASK)
                                    network->flags &=
                                        ~NETWORK_HAS_CCK;
                        }
                  }

                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_RATES_EX: '%s' (%d)\n",
                                   rates_str, network->rates_ex_len);
                  break;

            case MFIE_TYPE_DS_SET:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_DS_SET: %d\n",
                                   info_element->data[0]);
                  network->channel = info_element->data[0];
                  break;

            case MFIE_TYPE_FH_SET:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_FH_SET: ignored\n");
                  break;

            case MFIE_TYPE_CF_SET:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_CF_SET: ignored\n");
                  break;

            case MFIE_TYPE_TIM:
                  network->tim.tim_count = info_element->data[0];
                  network->tim.tim_period = info_element->data[1];
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_TIM: partially ignored\n");
                  break;

            case MFIE_TYPE_ERP_INFO:
                  network->erp_value = info_element->data[0];
                  network->flags |= NETWORK_HAS_ERP_VALUE;
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_ERP_SET: %d\n",
                                   network->erp_value);
                  break;

            case MFIE_TYPE_IBSS_SET:
                  network->atim_window = info_element->data[0];
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_IBSS_SET: %d\n",
                                   network->atim_window);
                  break;

            case MFIE_TYPE_CHALLENGE:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_CHALLENGE: ignored\n");
                  break;

            case MFIE_TYPE_GENERIC:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_GENERIC: %d bytes\n",
                                   info_element->len);
                  if (!ieee80211_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 MFIE_TYPE_RSN:
                  IEEE80211_DEBUG_MGMT("MFIE_TYPE_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 MFIE_TYPE_QOS_PARAMETER:
                  printk(KERN_ERR
                         "QoS Error need to parse QOS_PARAMETER IE\n");
                  break;
                  /* 802.11h */
            case MFIE_TYPE_POWER_CONSTRAINT:
                  network->power_constraint = info_element->data[0];
                  network->flags |= NETWORK_HAS_POWER_CONSTRAINT;
                  break;

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

            case MFIE_TYPE_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 MFIE_TYPE_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 MFIE_TYPE_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:
                  IEEE80211_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 ieee80211_info_element *)&info_element->
                data[info_element->len];
      }

      return 0;
}

static int ieee80211_handle_assoc_resp(struct ieee80211_device *ieee, struct ieee80211_assoc_response
                               *frame, struct ieee80211_rx_stats *stats)
{
      struct ieee80211_network network_resp = {
            .ibss_dfs = NULL,
      };
      struct ieee80211_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 == IEEE80211_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 (ieee80211_parse_info_param
          (frame->info_element, stats->len - sizeof(*frame), network))
            return 1;

      network->mode = 0;
      if (stats->freq == IEEE80211_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 (ieee80211_is_empty_essid(network->ssid, network->ssid_len))
            network->flags |= NETWORK_EMPTY_ESSID;

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

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

      return 0;
}

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

static int ieee80211_network_init(struct ieee80211_device *ieee, struct ieee80211_probe_response
                               *beacon,
                               struct ieee80211_network *network,
                               struct ieee80211_rx_stats *stats)
{
      DECLARE_MAC_BUF(mac);

      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 == IEEE80211_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 (ieee80211_parse_info_param
          (beacon->info_element, stats->len - sizeof(*beacon), network))
            return 1;

      network->mode = 0;
      if (stats->freq == IEEE80211_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) {
            IEEE80211_DEBUG_SCAN("Filtered out '%s (%s)' "
                             "network.\n",
                             escape_essid(network->ssid,
                                      network->ssid_len),
                             print_mac(mac, network->bssid));
            return 1;
      }

      if (ieee80211_is_empty_essid(network->ssid, network->ssid_len))
            network->flags |= NETWORK_EMPTY_ESSID;

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

      return 0;
}

static inline int is_same_network(struct ieee80211_network *src,
                          struct ieee80211_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) &&
            !compare_ether_addr(src->bssid, dst->bssid) &&
            !memcmp(src->ssid, dst->ssid, src->ssid_len));
}

static void update_network(struct ieee80211_network *dst,
                          struct ieee80211_network *src)
{
      int qos_active;
      u8 old_param;
      DECLARE_MAC_BUF(mac);

      ieee80211_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 ieee80211_rx_stats));
      else
            IEEE80211_DEBUG_SCAN("Network %s info received "
                  "off channel (%d vs. %d)\n", print_mac(mac, 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 ieee80211_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)
                  IEEE80211_DEBUG_QOS
                      ("QoS the network %s is QoS supported\n",
                       dst->ssid);
            else
                  IEEE80211_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 ieee80211_process_probe_response(struct ieee80211_device
                                        *ieee, struct
                                        ieee80211_probe_response
                                        *beacon, struct ieee80211_rx_stats
                                        *stats)
{
      struct net_device *dev = ieee->dev;
      struct ieee80211_network network = {
            .ibss_dfs = NULL,
      };
      struct ieee80211_network *target;
      struct ieee80211_network *oldest = NULL;
#ifdef CONFIG_IEEE80211_DEBUG
      struct ieee80211_info_element *info_element = beacon->info_element;
#endif
      unsigned long flags;
      DECLARE_MAC_BUF(mac);

      IEEE80211_DEBUG_SCAN("'%s' (%s"
                       "): %c%c%c%c %c%c%c%c-%c%c%c%c %c%c%c%c\n",
                       escape_essid(info_element->data,
                                info_element->len),
                       print_mac(mac, beacon->header.addr3),
                       (beacon->capability & (1 << 0xf)) ? '1' : '0',
                       (beacon->capability & (1 << 0xe)) ? '1' : '0',
                       (beacon->capability & (1 << 0xd)) ? '1' : '0',
                       (beacon->capability & (1 << 0xc)) ? '1' : '0',
                       (beacon->capability & (1 << 0xb)) ? '1' : '0',
                       (beacon->capability & (1 << 0xa)) ? '1' : '0',
                       (beacon->capability & (1 << 0x9)) ? '1' : '0',
                       (beacon->capability & (1 << 0x8)) ? '1' : '0',
                       (beacon->capability & (1 << 0x7)) ? '1' : '0',
                       (beacon->capability & (1 << 0x6)) ? '1' : '0',
                       (beacon->capability & (1 << 0x5)) ? '1' : '0',
                       (beacon->capability & (1 << 0x4)) ? '1' : '0',
                       (beacon->capability & (1 << 0x3)) ? '1' : '0',
                       (beacon->capability & (1 << 0x2)) ? '1' : '0',
                       (beacon->capability & (1 << 0x1)) ? '1' : '0',
                       (beacon->capability & (1 << 0x0)) ? '1' : '0');

      if (ieee80211_network_init(ieee, beacon, &network, stats)) {
            IEEE80211_DEBUG_SCAN("Dropped '%s' (%s) via %s.\n",
                             escape_essid(info_element->data,
                                      info_element->len),
                             print_mac(mac, 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) ||
                (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;
                  IEEE80211_DEBUG_SCAN("Expired '%s' (%s) from "
                                   "network list.\n",
                                   escape_essid(target->ssid,
                                            target->ssid_len),
                                   print_mac(mac, target->bssid));
                  ieee80211_network_reset(target);
            } else {
                  /* Otherwise just pull from the free list */
                  target = list_entry(ieee->network_free_list.next,
                                  struct ieee80211_network, list);
                  list_del(ieee->network_free_list.next);
            }

#ifdef CONFIG_IEEE80211_DEBUG
            IEEE80211_DEBUG_SCAN("Adding '%s' (%s) via %s.\n",
                             escape_essid(network.ssid,
                                      network.ssid_len),
                             print_mac(mac, 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 {
            IEEE80211_DEBUG_SCAN("Updating '%s' (%s) via %s.\n",
                             escape_essid(target->ssid,
                                      target->ssid_len),
                             print_mac(mac, 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 ieee80211_rx_mgt(struct ieee80211_device *ieee,
                  struct ieee80211_hdr_4addr *header,
                  struct ieee80211_rx_stats *stats)
{
      switch (WLAN_FC_GET_STYPE(le16_to_cpu(header->frame_ctl))) {
      case IEEE80211_STYPE_ASSOC_RESP:
            IEEE80211_DEBUG_MGMT("received ASSOCIATION RESPONSE (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));
            ieee80211_handle_assoc_resp(ieee,
                                  (struct ieee80211_assoc_response *)
                                  header, stats);
            break;

      case IEEE80211_STYPE_REASSOC_RESP:
            IEEE80211_DEBUG_MGMT("received REASSOCIATION RESPONSE (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));
            break;

      case IEEE80211_STYPE_PROBE_REQ:
            IEEE80211_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
                                        ieee80211_probe_request *)
                                       header, stats);
            break;

      case IEEE80211_STYPE_PROBE_RESP:
            IEEE80211_DEBUG_MGMT("received PROBE RESPONSE (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));
            IEEE80211_DEBUG_SCAN("Probe response\n");
            ieee80211_process_probe_response(ieee,
                                     (struct
                                      ieee80211_probe_response *)
                                     header, stats);
            break;

      case IEEE80211_STYPE_BEACON:
            IEEE80211_DEBUG_MGMT("received BEACON (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));
            IEEE80211_DEBUG_SCAN("Beacon\n");
            ieee80211_process_probe_response(ieee,
                                     (struct
                                      ieee80211_probe_response *)
                                     header, stats);
            break;
      case IEEE80211_STYPE_AUTH:

            IEEE80211_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 ieee80211_auth *)header);
            break;

      case IEEE80211_STYPE_DISASSOC:
            if (ieee->handle_disassoc != NULL)
                  ieee->handle_disassoc(ieee->dev,
                                    (struct ieee80211_disassoc *)
                                    header);
            break;

      case IEEE80211_STYPE_ACTION:
            IEEE80211_DEBUG_MGMT("ACTION\n");
            if (ieee->handle_action)
                  ieee->handle_action(ieee->dev,
                                  (struct ieee80211_action *)
                                  header, stats);
            break;

      case IEEE80211_STYPE_REASSOC_REQ:
            IEEE80211_DEBUG_MGMT("received reassoc (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));

            IEEE80211_DEBUG_MGMT("%s: IEEE80211_REASSOC_REQ received\n",
                             ieee->dev->name);
            if (ieee->handle_reassoc_request != NULL)
                  ieee->handle_reassoc_request(ieee->dev,
                                        (struct ieee80211_reassoc_request *)
                                         header);
            break;

      case IEEE80211_STYPE_ASSOC_REQ:
            IEEE80211_DEBUG_MGMT("received assoc (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));

            IEEE80211_DEBUG_MGMT("%s: IEEE80211_ASSOC_REQ received\n",
                             ieee->dev->name);
            if (ieee->handle_assoc_request != NULL)
                  ieee->handle_assoc_request(ieee->dev);
            break;

      case IEEE80211_STYPE_DEAUTH:
            IEEE80211_DEBUG_MGMT("DEAUTH\n");
            if (ieee->handle_deauth != NULL)
                  ieee->handle_deauth(ieee->dev,
                                  (struct ieee80211_deauth *)
                                  header);
            break;
      default:
            IEEE80211_DEBUG_MGMT("received UNKNOWN (%d)\n",
                             WLAN_FC_GET_STYPE(le16_to_cpu
                                           (header->frame_ctl)));
            IEEE80211_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(ieee80211_rx_any);
EXPORT_SYMBOL(ieee80211_rx_mgt);
EXPORT_SYMBOL(ieee80211_rx);

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