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
  47 /*---------------------  Static Functions  --------------------------*/
  48
  49 /*---------------------  Export Variables  --------------------------*/
  50
  51 /*
  52  * Description:
  53  *      Scan Rx cache.  Return true if packet is duplicate, else
  54  *      inserts in receive cache and returns false.
  55  *
  56  * Parameters:
  57  *  In:
  58  *      pCache      - Receive packets history
  59  *      pMACHeader  - 802.11 MAC Header of received packet
  60  *  Out:
  61  *      none
  62  *
  63  * Return Value: true if packet duplicate; otherwise false
  64  *
  65  */
  66
  67 bool WCTLbIsDuplicate(PSCache pCache, PS802_11Header pMACHeader)
  68 {
  69         unsigned int uIndex;
  70         unsigned int ii;
  71         PSCacheEntry    pCacheEntry;
  72
  73         if (IS_FC_RETRY(pMACHeader)) {
  74                 uIndex = pCache->uInPtr;
  75                 for (ii = 0; ii < DUPLICATE_RX_CACHE_LENGTH; ii++) {
  76                         pCacheEntry = &(pCache->asCacheEntry[uIndex]);
  77                         if ((pCacheEntry->wFmSequence == pMACHeader->wSeqCtl) &&
  78                             ether_addr_equal(pCacheEntry->abyAddr2,
  79                                              pMACHeader->abyAddr2)) {
  80                                 /* Duplicate match */
  81                                 return true;
  82                         }
  83                         ADD_ONE_WITH_WRAP_AROUND(uIndex, DUPLICATE_RX_CACHE_LENGTH);
  84                 }
  85         }
  86         /* Not fount in cache - insert */
  87         pCacheEntry = &pCache->asCacheEntry[pCache->uInPtr];
  88         pCacheEntry->wFmSequence = pMACHeader->wSeqCtl;
  89         memcpy(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
  90         ADD_ONE_WITH_WRAP_AROUND(pCache->uInPtr, DUPLICATE_RX_CACHE_LENGTH);
  91         return false;
  92 }
  93
  94 /*
  95  * Description:
  96  *      Found if sequence number of received fragment packet in Defragment Database
  97  *
  98  * Parameters:
  99  *  In:
 100  *      pDevice     - Pointer to adapter
 101  *      pMACHeader  - 802.11 MAC Header of received packet
 102  *  Out:
 103  *      none
 104  *
 105  * Return Value: index number in Defragment Database
 106  *
 107  */
 108 unsigned int WCTLuSearchDFCB(PSDevice pDevice, PS802_11Header pMACHeader)
 109 {
 110         unsigned int ii;
 111
 112         for (ii = 0; ii < pDevice->cbDFCB; ii++) {
 113                 if (pDevice->sRxDFCB[ii].bInUse &&
 114                     ether_addr_equal(pDevice->sRxDFCB[ii].abyAddr2,
 115                                      pMACHeader->abyAddr2)) {
 116                         return ii;
 117                 }
 118         }
 119         return pDevice->cbDFCB;
 120 }
 121
 122 /*
 123  * Description:
 124  *      Insert received fragment packet in Defragment Database
 125  *
 126  * Parameters:
 127  *  In:
 128  *      pDevice     - Pointer to adapter
 129  *      pMACHeader  - 802.11 MAC Header of received packet
 130  *  Out:
 131  *      none
 132  *
 133  * Return Value: index number in Defragment Database
 134  *
 135  */
 136 unsigned int WCTLuInsertDFCB(PSDevice pDevice, PS802_11Header pMACHeader)
 137 {
 138         unsigned int ii;
 139
 140         if (pDevice->cbFreeDFCB == 0)
 141                 return pDevice->cbDFCB;
 142         for (ii = 0; ii < pDevice->cbDFCB; ii++) {
 143                 if (!pDevice->sRxDFCB[ii].bInUse) {
 144                         pDevice->cbFreeDFCB--;
 145                         pDevice->sRxDFCB[ii].uLifetime = pDevice->dwMaxReceiveLifetime;
 146                         pDevice->sRxDFCB[ii].bInUse = true;
 147                         pDevice->sRxDFCB[ii].wSequence = (pMACHeader->wSeqCtl >> 4);
 148                         pDevice->sRxDFCB[ii].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
 149                         memcpy(&(pDevice->sRxDFCB[ii].abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
 150                         return ii;
 151                 }
 152         }
 153         return pDevice->cbDFCB;
 154 }
 155
 156 /*
 157  * Description:
 158  *      Handle received fragment packet
 159  *
 160  * Parameters:
 161  *  In:
 162  *      pDevice         - Pointer to adapter
 163  *      pMACHeader      - 802.11 MAC Header of received packet
 164  *      cbFrameLength   - Frame length
 165  *      bWEP            - is WEP packet
 166  *  Out:
 167  *      none
 168  *
 169  * Return Value: true if it is valid fragment packet and we have resource to defragment; otherwise false
 170  *
 171  */
 172 bool WCTLbHandleFragment(PSDevice pDevice, PS802_11Header pMACHeader, unsigned int cbFrameLength, bool bWEP, bool bExtIV)
 173 {
 174         unsigned int uHeaderSize;
 175
 176         if (bWEP) {
 177                 uHeaderSize = 28;
 178                 if (bExtIV)
 179                         // ExtIV
 180                         uHeaderSize += 4;
 181         } else {
 182                 uHeaderSize = 24;
 183         }
 184
 185         if (IS_FIRST_FRAGMENT_PKT(pMACHeader)) {
 186                 pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 187                 if (pDevice->uCurrentDFCBIdx < pDevice->cbDFCB) {
 188                         // duplicate, we must flush previous DCB
 189                         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].uLifetime = pDevice->dwMaxReceiveLifetime;
 190                         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence = (pMACHeader->wSeqCtl >> 4);
 191                         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
 192                 } else {
 193                         pDevice->uCurrentDFCBIdx = WCTLuInsertDFCB(pDevice, pMACHeader);
 194                         if (pDevice->uCurrentDFCBIdx == pDevice->cbDFCB)
 195                                 return false;
 196                 }
 197                 // reserve 4 byte to match MAC RX Buffer
 198                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer = (unsigned char *)(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].skb->data + 4);
 199                 memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, pMACHeader, cbFrameLength);
 200                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength = cbFrameLength;
 201                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += cbFrameLength;
 202                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 203                 return false;
 204         } else {
 205                 pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 206                 if (pDevice->uCurrentDFCBIdx != pDevice->cbDFCB) {
 207                         if ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence == (pMACHeader->wSeqCtl >> 4)) &&
 208                             (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum == (pMACHeader->wSeqCtl & 0x000F)) &&
 209                             ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength + cbFrameLength - uHeaderSize) < 2346)) {
 210                                 memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, ((unsigned char *)(pMACHeader) + uHeaderSize), (cbFrameLength - uHeaderSize));
 211                                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength += (cbFrameLength - uHeaderSize);
 212                                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += (cbFrameLength - uHeaderSize);
 213                                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 214                         } else {
 215                                 // seq error or frag # error flush DFCB
 216                                 pDevice->cbFreeDFCB++;
 217                                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 218                                 return false;
 219                         }
 220                 } else {
 221                         return false;
 222                 }
 223                 if (IS_LAST_FRAGMENT_PKT(pMACHeader)) {
 224                         //enq defragcontrolblock
 225                         pDevice->cbFreeDFCB++;
 226                         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 227                         return true;
 228                 }
 229                 return false;
 230         }
 231 }