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

  Copyright(c) 2003 - 2004 Intel Corporation. All rights reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  more details.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc., 59
  Temple Place - Suite 330, Boston, MA  02111-1307, USA.

  The full GNU General Public License is included in this distribution in the
  file called LICENSE.

  Contact Information:
  James P. Ketrenos <ipw2100-admin@linux.intel.com>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

******************************************************************************

  Few modifications for Realtek's Wi-Fi drivers by 
  Andrea Merello <andreamrl@tiscali.it>
  
  A special thanks goes to Realtek for their support ! 

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

#include <linux/compiler.h>
//#include <linux/config.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/pci.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/tcp.h>
#include <linux/types.h>
#include <linux/version.h>
#include <linux/wireless.h>
#include <linux/etherdevice.h>
#include <asm/uaccess.h>
#include <linux/if_vlan.h>

#include "ieee80211.h"


/*


802.11 Data Frame


802.11 frame_contorl for data frames - 2 bytes
     ,-----------------------------------------------------------------------------------------.
bits | 0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  a  |  b  |  c  |  d  |  e   |
     |----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|------|
val  | 0  |  0  |  0  |  1  |  x  |  0  |  0  |  0  |  1  |  0  |  x  |  x  |  x  |  x  |  x   |
     |----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|------|
desc | ^-ver-^  |  ^type-^  |  ^-----subtype-----^  | to  |from |more |retry| pwr |more |wep   |
     |          |           | x=0 data,x=1 data+ack | DS  | DS  |frag |     | mgm |data |      |
     '-----------------------------------------------------------------------------------------'
		                                    /\
                                                    |
802.11 Data Frame                                   |
           ,--------- 'ctrl' expands to >-----------'
          |
      ,--'---,-------------------------------------------------------------.
Bytes |  2   |  2   |    6    |    6    |    6    |  2   | 0..2312 |   4  |
      |------|------|---------|---------|---------|------|---------|------|
Desc. | ctrl | dura |  DA/RA  |   TA    |    SA   | Sequ |  Frame  |  fcs |
      |      | tion | (BSSID) |         |         | ence |  data   |      |
      `--------------------------------------------------|         |------'
Total: 28 non-data bytes                                 `----.----'
                                                              |
       .- 'Frame data' expands to <---------------------------'
       |
       V
      ,---------------------------------------------------.
Bytes |  1   |  1   |    1    |    3     |  2   |  0-2304 |
      |------|------|---------|----------|------|---------|
Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP      |
      | DSAP | SSAP |         |          |      | Packet  |
      | 0xAA | 0xAA |0x03 (UI)|0x00-00-F8|      |         |
      `-----------------------------------------|         |
Total: 8 non-data bytes                         `----.----'
                                                     |
       .- 'IP Packet' expands, if WEP enabled, to <--'
       |
       V
      ,-----------------------.
Bytes |  4  |   0-2296  |  4  |
      |-----|-----------|-----|
Desc. | IV  | Encrypted | ICV |
      |     | IP Packet |     |
      `-----------------------'
Total: 8 non-data bytes


802.3 Ethernet Data Frame

      ,-----------------------------------------.
Bytes |   6   |   6   |  2   |  Variable |   4  |
      |-------|-------|------|-----------|------|
Desc. | Dest. | Source| Type | IP Packet |  fcs |
      |  MAC  |  MAC  |      |           |      |
      `-----------------------------------------'
Total: 18 non-data bytes

In the event that fragmentation is required, the incoming payload is split into
N parts of size ieee->fts.  The first fragment contains the SNAP header and the
remaining packets are just data.

If encryption is enabled, each fragment payload size is reduced by enough space
to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP)
So if you have 1500 bytes of payload with ieee->fts set to 500 without
encryption it will take 3 frames.  With WEP it will take 4 frames as the
payload of each frame is reduced to 492 bytes.

* SKB visualization
*
*  ,- skb->data
* |
* |    ETHERNET HEADER        ,-<-- PAYLOAD
* |                           |     14 bytes from skb->data
* |  2 bytes for Type --> ,T. |     (sizeof ethhdr)
* |                       | | |
* |,-Dest.--. ,--Src.---. | | |
* |  6 bytes| | 6 bytes | | | |
* v         | |         | | | |
* 0         | v       1 | v | v           2
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
*     ^     | ^         | ^ |
*     |     | |         | | |
*     |     | |         | `T' <---- 2 bytes for Type
*     |     | |         |
*     |     | '---SNAP--' <-------- 6 bytes for SNAP
*     |     |
*     `-IV--' <-------------------- 4 bytes for IV (WEP)
*
*      SNAP HEADER
*
*/

static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 };
static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 };

static inline int ieee80211_put_snap(u8 *data, u16 h_proto)
{
	struct ieee80211_snap_hdr *snap;
	u8 *oui;

	snap = (struct ieee80211_snap_hdr *)data;
	snap->dsap = 0xaa;
	snap->ssap = 0xaa;
	snap->ctrl = 0x03;

	if (h_proto == 0x8137 || h_proto == 0x80f3)
		oui = P802_1H_OUI;
	else
		oui = RFC1042_OUI;
	snap->oui[0] = oui[0];
	snap->oui[1] = oui[1];
	snap->oui[2] = oui[2];

	*(u16 *)(data + SNAP_SIZE) = htons(h_proto);

	return SNAP_SIZE + sizeof(u16);
}

int ieee80211_encrypt_fragment(
	struct ieee80211_device *ieee,
	struct sk_buff *frag,
	int hdr_len)
{
	struct ieee80211_crypt_data* crypt = NULL;//ieee->crypt[ieee->tx_keyidx];
	int res;//, i;
//	printk("====>wwwwww%s():ieee:%x, hdr_len:%d\n", __FUNCTION__, ieee, hdr_len);
/*	  printk("\n%s(), hdr_len:%d\n", __FUNCTION__, hdr_len);
                 for (i = 0; i < 48; i++) {
                       if (i % 16 == 0) printk("\n\t");
                        printk("%2x ", *(frag->data+i));
                }
*/

#ifdef _RTL8187_EXT_PATCH_
#if 0
	i = ieee80211_find_MP(ieee, ((struct ieee80211_hdr*) frag->data)->addr1);
	if (i== -1){
		printk("error find MP entry in %s()\n", __FUNCTION__);
		 return i;
	}
	//  printk("%s():"MAC_FMT", find in index:%d\n", __FUNCTION__, MAC_ARG(((struct ieee80211_hdr*)frag->data)->addr1), i);
#endif
//	crypt = ieee->cryptlist[MAX_MP-1]->crypt[ieee->tx_keyidx];
	crypt = ieee->cryptlist[0]->crypt[ieee->tx_keyidx]; 
#else
	crypt = ieee->crypt[ieee->tx_keyidx];
#endif
	/*added to care about null crypt condition, to solve that system hangs when shared keys error*/
       	if (!crypt || !crypt->ops)
	return -1;	
	
#ifdef CONFIG_IEEE80211_CRYPT_TKIP
	struct ieee80211_hdr *header;

	if (ieee->tkip_countermeasures &&
	    crypt && crypt->ops && strcmp(crypt->ops->name, "TKIP") == 0) {
		header = (struct ieee80211_hdr *) frag->data;
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
			       "TX packet to " MAC_FMT "\n",
			       ieee->dev->name, MAC_ARG(header->addr1));
		}
		return -1;
	}
#endif
	/* To encrypt, frame format is:
	 * IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */

	// PR: FIXME: Copied from hostap. Check fragmentation/MSDU/MPDU encryption.
	/* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
	 * call both MSDU and MPDU encryption functions from here. */
	atomic_inc(&crypt->refcnt);
	res = 0;
	if (crypt->ops->encrypt_msdu)
		res = crypt->ops->encrypt_msdu(frag, hdr_len, crypt->priv);
	if (res == 0 && crypt->ops->encrypt_mpdu)
        res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv);
       	atomic_dec(&crypt->refcnt);
	if (res < 0) {
		printk(KERN_INFO "%s: Encryption failed: len=%d.\n",
		       ieee->dev->name, frag->len);
		ieee->ieee_stats.tx_discards++;
		return -1;
	}

	return 0;
}


void ieee80211_txb_free(struct ieee80211_txb *txb) {
	int i;
	if (unlikely(!txb))
		return;
	for (i = 0; i < txb->nr_frags; i++)
		if (txb->fragments[i])
			dev_kfree_skb_any(txb->fragments[i]);
	kfree(txb);
}

struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size,
					  int gfp_mask)
{
	struct ieee80211_txb *txb;
	int i;
	txb = kmalloc(
		sizeof(struct ieee80211_txb) + (sizeof(u8*) * nr_frags),
		gfp_mask);
	if (!txb)
		return NULL;

	memset(txb, 0, sizeof(struct ieee80211_txb));
	txb->nr_frags = nr_frags;
	txb->frag_size = txb_size;

	for (i = 0; i < nr_frags; i++) {
		txb->fragments[i] = dev_alloc_skb(txb_size);
		if (unlikely(!txb->fragments[i])) {
			i--;
			break;
		}
	}
	if (unlikely(i != nr_frags)) {
		while (i >= 0)
			dev_kfree_skb_any(txb->fragments[i--]);
		kfree(txb);
		return NULL;
	}
	return txb;
}

// Classify the to-be send data packet
// Need to acquire the sent queue index.
static int 
ieee80211_classify(struct sk_buff *skb, struct ieee80211_network *network)
{
  struct ether_header *eh = (struct ether_header*)skb->data;
  unsigned int wme_UP = 0;

  if(!network->QoS_Enable) {
     skb->priority = 0;
     return(wme_UP);
  }

  if(eh->ether_type == __constant_htons(ETHERTYPE_IP)) {
    const struct iphdr *ih = (struct iphdr*)(skb->data + \
		    sizeof(struct ether_header));
    wme_UP = (ih->tos >> 5)&0x07;
  } else if (vlan_tx_tag_present(skb)) {//vtag packet
#ifndef VLAN_PRI_SHIFT
#define VLAN_PRI_SHIFT  13              /* Shift to find VLAN user priority */
#define VLAN_PRI_MASK   7               /* Mask for user priority bits in VLAN */ 	  
#endif
	u32 tag = vlan_tx_tag_get(skb);
	wme_UP = (tag >> VLAN_PRI_SHIFT) & VLAN_PRI_MASK;
  } else if(ETH_P_PAE ==  ntohs(((struct ethhdr *)skb->data)->h_proto)) {
    //printk(KERN_WARNING "type = normal packet\n");
    wme_UP = 7;
  }
  skb->priority = wme_UP;
/* 
  if (network->QoS_Enable) {
    skb->priority = wme_UP;
  }else {
    skb->priority = 0;
  }
*/
  return(wme_UP);
}

#ifdef _RTL8187_EXT_PATCH_
// based on part of ieee80211_xmit. Mainly allocate txb. ieee->lock is held
struct ieee80211_txb *ieee80211_ext_alloc_txb(struct sk_buff *skb, struct net_device *dev, struct ieee80211_hdr_3addr *header, int hdr_len, u8 isQoS, u16 *pQOS_ctl, int isEncrypt, struct ieee80211_crypt_data* crypt)
{
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	struct ieee80211_device *ieee = netdev_priv(dev);
#else
	struct ieee80211_device *ieee = (struct ieee80211_device *)dev->priv;
#endif
	struct ieee80211_txb *txb = NULL;
	struct ieee80211_hdr_3addr *frag_hdr;
	int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size;
	int ether_type;
	int bytes, QOS_ctl;
	struct sk_buff *skb_frag;
	
	ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto);
	
	/* Advance the SKB to the start of the payload */
	skb_pull(skb, sizeof(struct ethhdr));
	
	/* Determine total amount of storage required for TXB packets */
	bytes = skb->len + SNAP_SIZE + sizeof(u16);
	
	/* Determine fragmentation size based on destination (multicast
	 * and broadcast are not fragmented) */
	// if (is_multicast_ether_addr(dest) ||
	// is_broadcast_ether_addr(dest)) {
	if (is_multicast_ether_addr(header->addr1) ||
			is_broadcast_ether_addr(header->addr1)) {
		frag_size = MAX_FRAG_THRESHOLD;
		QOS_ctl = QOS_CTL_NOTCONTAIN_ACK;
	}
	else {
		//printk(KERN_WARNING "&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&frag_size = %d\n", frag_size);
		frag_size = ieee->fts;//default:392
		QOS_ctl = 0;
	}
	
	if(isQoS) {
		QOS_ctl |= skb->priority; //set in the ieee80211_classify 	
		*pQOS_ctl = cpu_to_le16(QOS_ctl);
	}
	//printk(KERN_WARNING "header size = %d, QOS_ctl = %x\n", hdr_len,QOS_ctl);
	/* Determine amount of payload per fragment.  Regardless of if
	 * this stack is providing the full 802.11 header, one will
	 * eventually be affixed to this fragment -- so we must account for
	 * it when determining the amount of payload space. */
	//bytes_per_frag = frag_size - (IEEE80211_3ADDR_LEN + (ieee->current_network->QoS_Enable ? 2:0));
	bytes_per_frag = frag_size - hdr_len;
	if (ieee->config &
			(CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
		bytes_per_frag -= IEEE80211_FCS_LEN;
	
	/* Each fragment may need to have room for encryptiong pre/postfix */
	if (isEncrypt)
		bytes_per_frag -= crypt->ops->extra_prefix_len +
			crypt->ops->extra_postfix_len;
	
	/* Number of fragments is the total bytes_per_frag /
	 * payload_per_fragment */
	nr_frags = bytes / bytes_per_frag;
	bytes_last_frag = bytes % bytes_per_frag;
	if (bytes_last_frag)
		nr_frags++;
	else
		bytes_last_frag = bytes_per_frag;
	
	/* When we allocate the TXB we allocate enough space for the reserve
	 * and full fragment bytes (bytes_per_frag doesn't include prefix,
	 * postfix, header, FCS, etc.) */
	txb = ieee80211_alloc_txb(nr_frags, frag_size, GFP_ATOMIC);
	if (unlikely(!txb)) {
		printk(KERN_WARNING "%s: Could not allocate TXB\n",
			ieee->dev->name);
		return NULL;
	}
	txb->encrypted = isEncrypt;
	txb->payload_size = bytes;
	
	for (i = 0; i < nr_frags; i++) {
		skb_frag = txb->fragments[i];
		skb_frag->priority = UP2AC(skb->priority);	
		if (isEncrypt)
			skb_reserve(skb_frag, crypt->ops->extra_prefix_len);
	
		frag_hdr = (struct ieee80211_hdr_3addr *)skb_put(skb_frag, hdr_len);
		memcpy(frag_hdr, (void *)header, hdr_len);
	
		/* If this is not the last fragment, then add the MOREFRAGS
		 * bit to the frame control */
		if (i != nr_frags - 1) {
			frag_hdr->frame_ctl = cpu_to_le16(
					header->frame_ctl | IEEE80211_FCTL_MOREFRAGS);
			bytes = bytes_per_frag;
		
		} else {
			/* The last fragment takes the remaining length */
			bytes = bytes_last_frag;
		}
		
		frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl[0]<<4 | i);
		//frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl<<4 | i);
		//
			
		/* Put a SNAP header on the first fragment */
		if (i == 0) {
			ieee80211_put_snap(
				skb_put(skb_frag, SNAP_SIZE + sizeof(u16)), ether_type);
			bytes -= SNAP_SIZE + sizeof(u16);
		}
	
		memcpy(skb_put(skb_frag, bytes), skb->data, bytes);
	
		/* Advance the SKB... */
		skb_pull(skb, bytes);
	
		/* Encryption routine will move the header forward in order
		 * to insert the IV between the header and the payload */
		if (isEncrypt)
			ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
		if (ieee->config &
				(CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
			skb_put(skb_frag, 4);
	}
	// Advance sequence number in data frame. 
	//printk(KERN_WARNING "QoS Enalbed? %s\n", ieee->current_network.QoS_Enable?"Y":"N");	
	if (ieee->seq_ctrl[0] == 0xFFF)
		ieee->seq_ctrl[0] = 0;
	else
		ieee->seq_ctrl[0]++;
	// stanley, just for debug
/*
{
	int j=0;
	for(j=0;j<nr_frags;j++)
	{
			int i;
		struct sk_buff *skb = txb->fragments[j];
			printk("send(%d): ", j);
			for (i=0;i<skb->len;i++)
				printk("%02X ", skb->data[i]&0xff);
			printk("\n");
	}
}
*/
	
	return txb;
}


// based on part of ieee80211_xmit. Mainly allocate txb. ieee->lock is held
// Assume no encryption, no FCS computing
struct ieee80211_txb *ieee80211_ext_reuse_txb(struct sk_buff *skb, struct net_device *dev, struct ieee80211_hdr_3addr *header, int hdr_len, u8 isQoS, u16 *pQOS_ctl, int isEncrypt, struct ieee80211_crypt_data* crypt)
{
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	struct ieee80211_device *ieee = netdev_priv(dev);
#else
	struct ieee80211_device *ieee = (struct ieee80211_device *)dev->priv;
#endif
	struct ieee80211_txb *txb = NULL;
	struct ieee80211_hdr_3addr *frag_hdr;
	int ether_type;
	int bytes, QOS_ctl;
	
	ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto);
	
	/* Advance the SKB to the start of the payload */
	skb_pull(skb, sizeof(struct ethhdr));
	
	/* Determine total amount of storage required for TXB packets */
	bytes = skb->len + SNAP_SIZE + sizeof(u16);
	
	if (is_multicast_ether_addr(header->addr1) ||
			is_broadcast_ether_addr(header->addr1)) {
		QOS_ctl = QOS_CTL_NOTCONTAIN_ACK;
	}
	else {
		QOS_ctl = 0;
	}
	
	if(isQoS) {
		QOS_ctl |= skb->priority; //set in the ieee80211_classify 	
		*pQOS_ctl = cpu_to_le16(QOS_ctl);
	}
				
	txb = kmalloc( sizeof(struct ieee80211_txb) + sizeof(u8*), GFP_ATOMIC );
	if (unlikely(!txb)) {
		printk(KERN_WARNING "%s: Could not allocate TXB\n",
			ieee->dev->name);
		return NULL;
	}
		
	txb->nr_frags = 1;
	txb->frag_size = bytes;
	txb->encrypted = isEncrypt;
	txb->payload_size = bytes;
	
	txb->fragments[0] = skb;
	ieee80211_put_snap(
			skb_push(skb, SNAP_SIZE + sizeof(u16)), ether_type);
	frag_hdr = (struct ieee80211_hdr_3addr *)skb_push(skb, hdr_len);
	memcpy(frag_hdr, (void *)header, hdr_len);
	frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl[0]<<4 | 0);
	skb->priority = UP2AC(skb->priority);	
	if(isEncrypt)
                ieee80211_encrypt_fragment(ieee,skb,hdr_len);

	// Advance sequence number in data frame. 
	//printk(KERN_WARNING "QoS Enalbed? %s\n", ieee->current_network.QoS_Enable?"Y":"N");	
	if (ieee->seq_ctrl[0] == 0xFFF)
		ieee->seq_ctrl[0] = 0;
	else
		ieee->seq_ctrl[0]++;
	
	return txb;
}

#endif // _RTL8187_EXT_PATCH_

/* SKBs are added to the ieee->tx_queue. */
int ieee80211_xmit(struct sk_buff *skb,
		   struct net_device *dev)
{
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0))
	struct ieee80211_device *ieee = netdev_priv(dev);
#else
	struct ieee80211_device *ieee = (struct ieee80211_device *)dev->priv;
#endif
	struct ieee80211_txb *txb = NULL;
	struct ieee80211_hdr_3addr_QOS *frag_hdr;
	int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size;
	unsigned long flags;
	struct net_device_stats *stats = &ieee->stats;
	int ether_type, encrypt;
	int bytes, fc, QOS_ctl, hdr_len;
	struct sk_buff *skb_frag;
	//struct ieee80211_hdr header = { /* Ensure zero initialized */
	//	.duration_id = 0,
	//	.seq_ctl = 0
	//};
	struct ieee80211_hdr_3addr_QOS header = { /* Ensure zero initialized */
		.duration_id = 0,
		.seq_ctl = 0,
		.QOS_ctl = 0
	};
	u8 dest[ETH_ALEN], src[ETH_ALEN];

	struct ieee80211_crypt_data* crypt;

	//printk(KERN_WARNING "upper layer packet!\n");
	spin_lock_irqsave(&ieee->lock, flags);

	/* If there is no driver handler to take the TXB, dont' bother
	 * creating it... */
	if ((!ieee->hard_start_xmit && !(ieee->softmac_features & IEEE_SOFTMAC_TX_QUEUE))||
	   ((!ieee->softmac_data_hard_start_xmit && (ieee->softmac_features & IEEE_SOFTMAC_TX_QUEUE)))) {
		printk(KERN_WARNING "%s: No xmit handler.\n",
		       ieee->dev->name);
		goto success;
	}
	
	ieee80211_classify(skb,&ieee->current_network);
	if(likely(ieee->raw_tx == 0)){
	
		if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) {
			printk(KERN_WARNING "%s: skb too small (%d).\n",
			ieee->dev->name, skb->len);
			goto success;
		}
	
		
#ifdef _RTL8187_EXT_PATCH_
		// note, skb->priority which was set by ieee80211_classify, and used by physical tx
		if((ieee->iw_mode == ieee->iw_ext_mode) && (ieee->ext_patch_ieee80211_xmit))
		{
			txb = ieee->ext_patch_ieee80211_xmit(skb, dev);
			goto success;
		}
#endif

		ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto);
#ifdef _RTL8187_EXT_PATCH_
		crypt = ieee->cryptlist[0]->crypt[ieee->tx_keyidx];
#else	
		crypt = ieee->crypt[ieee->tx_keyidx];
#endif	
		encrypt = !(ether_type == ETH_P_PAE && ieee->ieee802_1x) &&
			ieee->host_encrypt && crypt && crypt->ops;
	
		if (!encrypt && ieee->ieee802_1x &&
		ieee->drop_unencrypted && ether_type != ETH_P_PAE) {
			stats->tx_dropped++;
			goto success;
		}
	
	#ifdef CONFIG_IEEE80211_DEBUG
		if (crypt && !encrypt && ether_type == ETH_P_PAE) {
			struct eapol *eap = (struct eapol *)(skb->data +
				sizeof(struct ethhdr) - SNAP_SIZE - sizeof(u16));
			IEEE80211_DEBUG_EAP("TX: IEEE 802.11 EAPOL frame: %s\n",
				eap_get_type(eap->type));
		}
	#endif
	
		/* Save source and destination addresses */
		memcpy(&dest, skb->data, ETH_ALEN);
		memcpy(&src, skb->data+ETH_ALEN, ETH_ALEN);
	
		/* Advance the SKB to the start of the payload */
		skb_pull(skb, sizeof(struct ethhdr));
	
		/* Determine total amount of storage required for TXB packets */
		bytes = skb->len + SNAP_SIZE + sizeof(u16);
	
		if(ieee->current_network.QoS_Enable) {
			if (encrypt)
				fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_DATA |
					IEEE80211_FCTL_WEP;
			else
				fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_DATA;

		} else {
			if (encrypt)
				fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA |
					IEEE80211_FCTL_WEP;
			else
				fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
		}
	
		if (ieee->iw_mode == IW_MODE_INFRA) {
			fc |= IEEE80211_FCTL_TODS;
			/* To DS: Addr1 = BSSID, Addr2 = SA,
			Addr3 = DA */
			memcpy(&header.addr1, ieee->current_network.bssid, ETH_ALEN);
			memcpy(&header.addr2, &src, ETH_ALEN);
			memcpy(&header.addr3, &dest, ETH_ALEN);
		} else if (ieee->iw_mode == IW_MODE_ADHOC) {
			/* not From/To DS: Addr1 = DA, Addr2 = SA,
			Addr3 = BSSID */
			memcpy(&header.addr1, dest, ETH_ALEN);
			memcpy(&header.addr2, src, ETH_ALEN);
			memcpy(&header.addr3, ieee->current_network.bssid, ETH_ALEN);
		}
	//	printk(KERN_WARNING "essid MAC address is "MAC_FMT, MAC_ARG(&header.addr1));
		header.frame_ctl = cpu_to_le16(fc);
		//hdr_len = IEEE80211_3ADDR_LEN;
	
		/* Determine fragmentation size based on destination (multicast
		* and broadcast are not fragmented) */
//		if (is_multicast_ether_addr(dest) ||
//		is_broadcast_ether_addr(dest)) {
		if (is_multicast_ether_addr(header.addr1) ||
		is_broadcast_ether_addr(header.addr1)) {
			frag_size = MAX_FRAG_THRESHOLD;
			QOS_ctl = QOS_CTL_NOTCONTAIN_ACK;
		}
		else {
			//printk(KERN_WARNING "&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&frag_size = %d\n", frag_size);
			frag_size = ieee->fts;//default:392
			QOS_ctl = 0;
		}
	
		if (ieee->current_network.QoS_Enable)	{
			hdr_len = IEEE80211_3ADDR_LEN + 2;
			QOS_ctl |= skb->priority; //set in the ieee80211_classify 	
			header.QOS_ctl = cpu_to_le16(QOS_ctl);
		} else {
			hdr_len = IEEE80211_3ADDR_LEN;		
		}
		//printk(KERN_WARNING "header size = %d, QOS_ctl = %x\n", hdr_len,QOS_ctl);
		/* Determine amount of payload per fragment.  Regardless of if
		* this stack is providing the full 802.11 header, one will
		* eventually be affixed to this fragment -- so we must account for
		* it when determining the amount of payload space. */
		//bytes_per_frag = frag_size - (IEEE80211_3ADDR_LEN + (ieee->current_network->QoS_Enable ? 2:0));
		bytes_per_frag = frag_size - hdr_len;
		if (ieee->config &
		(CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
			bytes_per_frag -= IEEE80211_FCS_LEN;
	
		/* Each fragment may need to have room for encryptiong pre/postfix */
		if (encrypt)
			bytes_per_frag -= crypt->ops->extra_prefix_len +
				crypt->ops->extra_postfix_len;
	
		/* Number of fragments is the total bytes_per_frag /
		* payload_per_fragment */
		nr_frags = bytes / bytes_per_frag;
		bytes_last_frag = bytes % bytes_per_frag;
		if (bytes_last_frag)
			nr_frags++;
		else
			bytes_last_frag = bytes_per_frag;
	
		/* When we allocate the TXB we allocate enough space for the reserve
		* and full fragment bytes (bytes_per_frag doesn't include prefix,
		* postfix, header, FCS, etc.) */
		txb = ieee80211_alloc_txb(nr_frags, frag_size, GFP_ATOMIC);
		if (unlikely(!txb)) {
			printk(KERN_WARNING "%s: Could not allocate TXB\n",
			ieee->dev->name);
			goto failed;
		}
		txb->encrypted = encrypt;
		txb->payload_size = bytes;
	
		for (i = 0; i < nr_frags; i++) {
			skb_frag = txb->fragments[i];
			skb_frag->priority = UP2AC(skb->priority);	
			if (encrypt)
				skb_reserve(skb_frag, crypt->ops->extra_prefix_len);
	
			frag_hdr = (struct ieee80211_hdr_3addr_QOS *)skb_put(skb_frag, hdr_len);
			memcpy(frag_hdr, &header, hdr_len);
	
			/* If this is not the last fragment, then add the MOREFRAGS
			* bit to the frame control */
			if (i != nr_frags - 1) {
				frag_hdr->frame_ctl = cpu_to_le16(
					fc | IEEE80211_FCTL_MOREFRAGS);
				bytes = bytes_per_frag;
		
			} else {
				/* The last fragment takes the remaining length */
				bytes = bytes_last_frag;
			}
			if(ieee->current_network.QoS_Enable) {	
			  // add 1 only indicate to corresponding seq number control 2006/7/12
			  frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl[UP2AC(skb->priority)+1]<<4 | i);
			  //printk(KERN_WARNING "skb->priority = %d,", skb->priority);
			  //printk(KERN_WARNING "type:%d: seq = %d\n",UP2AC(skb->priority),ieee->seq_ctrl[UP2AC(skb->priority)+1]);
			} else {
			  frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl[0]<<4 | i);
			}
			//frag_hdr->seq_ctl = cpu_to_le16(ieee->seq_ctrl<<4 | i);
			//
			
			/* Put a SNAP header on the first fragment */
			if (i == 0) {
				ieee80211_put_snap(
					skb_put(skb_frag, SNAP_SIZE + sizeof(u16)),
					ether_type);
				bytes -= SNAP_SIZE + sizeof(u16);
			}
	
			memcpy(skb_put(skb_frag, bytes), skb->data, bytes);
	
			/* Advance the SKB... */
			skb_pull(skb, bytes);
	
			/* Encryption routine will move the header forward in order
			* to insert the IV between the header and the payload */
			if (encrypt)
				ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
			if (ieee->config &
			(CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
				skb_put(skb_frag, 4);
		}
		// Advance sequence number in data frame. 
		//printk(KERN_WARNING "QoS Enalbed? %s\n", ieee->current_network.QoS_Enable?"Y":"N");	
		if (ieee->current_network.QoS_Enable) {
		  if (ieee->seq_ctrl[UP2AC(skb->priority) + 1] == 0xFFF)
			ieee->seq_ctrl[UP2AC(skb->priority) + 1] = 0;
		  else
			ieee->seq_ctrl[UP2AC(skb->priority) + 1]++;
		} else {
  		  if (ieee->seq_ctrl[0] == 0xFFF)
			ieee->seq_ctrl[0] = 0;
		  else
			ieee->seq_ctrl[0]++;
		}
		//---
	}else{
		if (unlikely(skb->len < sizeof(struct ieee80211_hdr_3addr))) {
			printk(KERN_WARNING "%s: skb too small (%d).\n",
			ieee->dev->name, skb->len);
			goto success;
		}
	
		txb = ieee80211_alloc_txb(1, skb->len, GFP_ATOMIC);
		if(!txb){
			printk(KERN_WARNING "%s: Could not allocate TXB\n",
			ieee->dev->name);
			goto failed;
		}
		
		txb->encrypted = 0;
		txb->payload_size = skb->len;
		memcpy(skb_put(txb->fragments[0],skb->len), skb->data, skb->len);
	}	

 success:
	spin_unlock_irqrestore(&ieee->lock, flags);
#ifdef _RTL8187_EXT_PATCH_
	// Sometimes, extension mode can reuse skb (by txb->fragments[0])
	if( ! ((ieee->iw_mode == ieee->iw_ext_mode) && txb && (txb->fragments[0] == skb)) )
#endif
		dev_kfree_skb_any(skb);
	if (txb) {
		if (ieee->softmac_features & IEEE_SOFTMAC_TX_QUEUE){
			ieee80211_softmac_xmit(txb, ieee);
		}else{
			if ((*ieee->hard_start_xmit)(txb, dev) == 0) {
				stats->tx_packets++;
				stats->tx_bytes += txb->payload_size;
				return 0;
			}
			ieee80211_txb_free(txb);
		}
	}

	return 0;

 failed:
	spin_unlock_irqrestore(&ieee->lock, flags);
	netif_stop_queue(dev);
	printk("netif_stop_queue in ieee80211_xmit \n");
	stats->tx_errors++;
	return 1;

}



#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
EXPORT_SYMBOL(ieee80211_txb_free);
#ifdef _RTL8187_EXT_PATCH_
EXPORT_SYMBOL(ieee80211_alloc_txb);
EXPORT_SYMBOL(ieee80211_ext_alloc_txb);
EXPORT_SYMBOL(ieee80211_ext_reuse_txb);

EXPORT_SYMBOL(ieee80211_encrypt_fragment);
#endif // _RTL8187_EXT_PATCH_
#else
EXPORT_SYMBOL_NOVERS(ieee80211_txb_free);
#ifdef _RTL8187_EXT_PATCH_
EXPORT_SYMBOL_NOVERS(ieee80211_alloc_txb);
EXPORT_SYMBOL_NOVERS(ieee80211_ext_reuse_txb);

EXPORT_SYMBOL_NOVERS(ieee80211_encrypt_fragment);
#endif // _RTL8187_EXT_PATCH_
#endif

