drivers/staging/vt6655/wctl.c

   1 /*
   2  * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
   3  * All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * File: wctl.c
  20  *
  21  * Purpose: handle WMAC duplicate filter & defragment
  22  *
  23  * Author: Jerry Chen
  24  *
  25  * Date: Jun. 27, 2002
  26  *
  27  * Functions:
  28  *      WCTLbIsDuplicate - Test if duplicate packet
  29  *      WCTLuSearchDFCB - Search DeFragment Control Database
  30  *      WCTLuInsertDFCB - Insert DeFragment Control Database
  31  *      WCTLbHandleFragment - Handle received fragment packet
  32  *
  33  * Revision History:
  34  *
  35  */
  36
  37 #include "wctl.h"
  38 #include "device.h"
  39 #include "card.h"
  40
  41 /*---------------------  Static Definitions -------------------------*/
  42
  43 /*---------------------  Static Classes  ----------------------------*/
  44
  45 /*---------------------  Static Variables  --------------------------*/
  46 // static int          msglevel                =MSG_LEVEL_INFO;
  47 /*---------------------  Static Functions  --------------------------*/
  48
  49 /*---------------------  Export Variables  --------------------------*/
  50
  51
  52
  53 /*
  54  * Description:
  55  *      Scan Rx cache.  Return true if packet is duplicate, else
  56  *      inserts in receive cache and returns false.
  57  *
  58  * Parameters:
  59  *  In:
  60  *      pCache      - Receive packets history
  61  *      pMACHeader  - 802.11 MAC Header of received packet
  62  *  Out:
  63  *      none
  64  *
  65  * Return Value: true if packet duplicate; otherwise false
  66  *
  67  */
  68
  69 bool WCTLbIsDuplicate (PSCache pCache, PS802_11Header pMACHeader)
  70 {
  71     unsigned int uIndex;
  72     unsigned int ii;
  73     PSCacheEntry    pCacheEntry;
  74
  75     if (IS_FC_RETRY(pMACHeader)) {
  76
  77         uIndex = pCache->uInPtr;
  78         for (ii = 0; ii < DUPLICATE_RX_CACHE_LENGTH; ii++) {
  79             pCacheEntry = &(pCache->asCacheEntry[uIndex]);
  80             if ((pCacheEntry->wFmSequence == pMACHeader->wSeqCtl) &&
  81                 (!compare_ether_addr(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->abyAddr2[0])))
  82                 ) {
  83                 /* Duplicate match */
  84                 return true;
  85             }
  86             ADD_ONE_WITH_WRAP_AROUND(uIndex, DUPLICATE_RX_CACHE_LENGTH);
  87         }
  88     }
  89     /* Not fount in cache - insert */
  90     pCacheEntry = &pCache->asCacheEntry[pCache->uInPtr];
  91     pCacheEntry->wFmSequence = pMACHeader->wSeqCtl;
  92     memcpy(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
  93     ADD_ONE_WITH_WRAP_AROUND(pCache->uInPtr, DUPLICATE_RX_CACHE_LENGTH);
  94     return false;
  95 }
  96
  97 /*
  98  * Description:
  99  *      Found if sequence number of received fragment packet in Defragment Database
 100  *
 101  * Parameters:
 102  *  In:
 103  *      pDevice     - Pointer to adapter
 104  *      pMACHeader  - 802.11 MAC Header of received packet
 105  *  Out:
 106  *      none
 107  *
 108  * Return Value: index number in Defragment Database
 109  *
 110  */
 111 unsigned int WCTLuSearchDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
 112 {
 113 unsigned int ii;
 114
 115     for(ii=0;ii<pDevice->cbDFCB;ii++) {
 116         if ((pDevice->sRxDFCB[ii].bInUse == true) &&
 117             (!compare_ether_addr(&(pDevice->sRxDFCB[ii].abyAddr2[0]), &(pMACHeader->abyAddr2[0])))
 118             ) {
 119             //
 120             return(ii);
 121         }
 122     }
 123     return(pDevice->cbDFCB);
 124 }
 125
 126
 127 /*
 128  * Description:
 129  *      Insert received fragment packet in Defragment Database
 130  *
 131  * Parameters:
 132  *  In:
 133  *      pDevice     - Pointer to adapter
 134  *      pMACHeader  - 802.11 MAC Header of received packet
 135  *  Out:
 136  *      none
 137  *
 138  * Return Value: index number in Defragment Database
 139  *
 140  */
 141 unsigned int WCTLuInsertDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
 142 {
 143 unsigned int ii;
 144
 145     if (pDevice->cbFreeDFCB == 0)
 146         return(pDevice->cbDFCB);
 147     for(ii=0;ii<pDevice->cbDFCB;ii++) {
 148         if (pDevice->sRxDFCB[ii].bInUse == false) {
 149             pDevice->cbFreeDFCB--;
 150             pDevice->sRxDFCB[ii].uLifetime = pDevice->dwMaxReceiveLifetime;
 151             pDevice->sRxDFCB[ii].bInUse = true;
 152             pDevice->sRxDFCB[ii].wSequence = (pMACHeader->wSeqCtl >> 4);
 153             pDevice->sRxDFCB[ii].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
 154             memcpy(&(pDevice->sRxDFCB[ii].abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
 155             return(ii);
 156         }
 157     }
 158     return(pDevice->cbDFCB);
 159 }
 160
 161
 162 /*
 163  * Description:
 164  *      Handle received fragment packet
 165  *
 166  * Parameters:
 167  *  In:
 168  *      pDevice         - Pointer to adapter
 169  *      pMACHeader      - 802.11 MAC Header of received packet
 170  *      cbFrameLength   - Frame length
 171  *      bWEP            - is WEP packet
 172  *  Out:
 173  *      none
 174  *
 175  * Return Value: true if it is valid fragment packet and we have resource to defragment; otherwise false
 176  *
 177  */
 178 bool WCTLbHandleFragment (PSDevice pDevice, PS802_11Header pMACHeader, unsigned int cbFrameLength, bool bWEP, bool bExtIV)
 179 {
 180 unsigned int uHeaderSize;
 181
 182
 183     if (bWEP == true) {
 184         uHeaderSize = 28;
 185         if (bExtIV)
 186         // ExtIV
 187             uHeaderSize +=4;
 188     }
 189     else {
 190         uHeaderSize = 24;
 191     }
 192
 193     if (IS_FIRST_FRAGMENT_PKT(pMACHeader)) {
 194         pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 195         if (pDevice->uCurrentDFCBIdx < pDevice->cbDFCB) {
 196             // duplicate, we must flush previous DCB
 197             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].uLifetime = pDevice->dwMaxReceiveLifetime;
 198             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence = (pMACHeader->wSeqCtl >> 4);
 199             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
 200         }
 201         else {
 202             pDevice->uCurrentDFCBIdx = WCTLuInsertDFCB(pDevice, pMACHeader);
 203             if (pDevice->uCurrentDFCBIdx == pDevice->cbDFCB) {
 204                 return(false);
 205             }
 206         }
 207         // reserve 4 byte to match MAC RX Buffer
 208         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer = (unsigned char *) (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].skb->data + 4);
 209         memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, pMACHeader, cbFrameLength);
 210         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength = cbFrameLength;
 211         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += cbFrameLength;
 212         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 213         //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "First pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 214         return(false);
 215     }
 216     else {
 217         pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 218         if (pDevice->uCurrentDFCBIdx != pDevice->cbDFCB) {
 219             if ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence == (pMACHeader->wSeqCtl >> 4)) &&
 220                 (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum == (pMACHeader->wSeqCtl & 0x000F)) &&
 221                 ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength + cbFrameLength - uHeaderSize) < 2346)) {
 222
 223                 memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, ((unsigned char *) (pMACHeader) + uHeaderSize), (cbFrameLength - uHeaderSize));
 224                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength += (cbFrameLength - uHeaderSize);
 225                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += (cbFrameLength - uHeaderSize);
 226                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 227                 //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Second pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 228             }
 229             else {
 230                 // seq error or frag # error flush DFCB
 231                 pDevice->cbFreeDFCB++;
 232                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 233                 return(false);
 234             }
 235         }
 236         else {
 237             return(false);
 238         }
 239         if (IS_LAST_FRAGMENT_PKT(pMACHeader)) {
 240             //enq defragcontrolblock
 241             pDevice->cbFreeDFCB++;
 242             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 243             //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Last pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 244             return(true);
 245         }
 246         return(false);
 247     }
 248 }
 249
 250