drivers/staging/vt6656/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 #include "tmacro.h"
  41
  42 // static int          msglevel                =MSG_LEVEL_INFO;
  43
  44 /*
  45  * Description:
  46  *      Scan Rx cache.  Return true if packet is duplicate, else
  47  *      inserts in receive cache and returns false.
  48  *
  49  * Parameters:
  50  *  In:
  51  *      pCache      - Receive packets history
  52  *      pMACHeader  - 802.11 MAC Header of received packet
  53  *  Out:
  54  *      none
  55  *
  56  * Return Value: true if packet duplicate; otherwise false
  57  *
  58  */
  59
  60 bool WCTLbIsDuplicate (PSCache pCache, struct ieee80211_hdr *pMACHeader)
  61 {
  62     unsigned int            uIndex;
  63     unsigned int            ii;
  64     PSCacheEntry    pCacheEntry;
  65
  66     if (IS_FC_RETRY(pMACHeader)) {
  67
  68         uIndex = pCache->uInPtr;
  69         for (ii = 0; ii < DUPLICATE_RX_CACHE_LENGTH; ii++) {
  70             pCacheEntry = &(pCache->asCacheEntry[uIndex]);
  71             if ((pCacheEntry->wFmSequence == pMACHeader->seq_ctrl) &&
  72                 ether_addr_equal(pCacheEntry->abyAddr2, pMACHeader->addr2) &&
  73                 (pCacheEntry->wFrameCtl == pMACHeader->frame_control)
  74                 ) {
  75                 /* Duplicate match */
  76                 return true;
  77             }
  78             ADD_ONE_WITH_WRAP_AROUND(uIndex, DUPLICATE_RX_CACHE_LENGTH);
  79         }
  80     }
  81     /* Not found in cache - insert */
  82     pCacheEntry = &pCache->asCacheEntry[pCache->uInPtr];
  83     pCacheEntry->wFmSequence = pMACHeader->seq_ctrl;
  84     memcpy(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->addr2[0]), ETH_ALEN);
  85     pCacheEntry->wFrameCtl = pMACHeader->frame_control;
  86     ADD_ONE_WITH_WRAP_AROUND(pCache->uInPtr, DUPLICATE_RX_CACHE_LENGTH);
  87     return false;
  88 }
  89
  90 /*
  91  * Description:
  92  *      Found if sequence number of received fragment packet in Defragment Database
  93  *
  94  * Parameters:
  95  *  In:
  96  *      pDevice     - Pointer to adapter
  97  *      pMACHeader  - 802.11 MAC Header of received packet
  98  *  Out:
  99  *      none
 100  *
 101  * Return Value: index number in Defragment Database
 102  *
 103  */
 104
 105 unsigned int WCTLuSearchDFCB(struct vnt_private *pDevice,
 106                              struct ieee80211_hdr *pMACHeader)
 107 {
 108         unsigned int ii;
 109
 110         for (ii = 0; ii < pDevice->cbDFCB; ii++) {
 111                 if ((pDevice->sRxDFCB[ii].bInUse == true) &&
 112                     ether_addr_equal(pDevice->sRxDFCB[ii].abyAddr2,
 113                                      pMACHeader->addr2)) {
 114                         return ii;
 115                 }
 116         }
 117         return pDevice->cbDFCB;
 118 }
 119
 120 /*
 121  * Description:
 122  *      Insert received fragment packet in Defragment Database
 123  *
 124  * Parameters:
 125  *  In:
 126  *      pDevice     - Pointer to adapter
 127  *      pMACHeader  - 802.11 MAC Header of received packet
 128  *  Out:
 129  *      none
 130  *
 131  * Return Value: index number in Defragment Database
 132  *
 133  */
 134 unsigned int WCTLuInsertDFCB(struct vnt_private *pDevice,
 135                              struct ieee80211_hdr *pMACHeader)
 136 {
 137         unsigned int ii;
 138
 139     if (pDevice->cbFreeDFCB == 0)
 140         return(pDevice->cbDFCB);
 141     for (ii = 0; ii < pDevice->cbDFCB; ii++) {
 142         if (pDevice->sRxDFCB[ii].bInUse == false) {
 143             pDevice->cbFreeDFCB--;
 144             pDevice->sRxDFCB[ii].uLifetime = pDevice->dwMaxReceiveLifetime;
 145             pDevice->sRxDFCB[ii].bInUse = true;
 146             pDevice->sRxDFCB[ii].wSequence = (pMACHeader->seq_ctrl >> 4);
 147             pDevice->sRxDFCB[ii].wFragNum = (pMACHeader->seq_ctrl & 0x000F);
 148             memcpy(&(pDevice->sRxDFCB[ii].abyAddr2[0]),
 149                    &(pMACHeader->addr2[0]),
 150                    ETH_ALEN);
 151             return(ii);
 152         }
 153     }
 154     return(pDevice->cbDFCB);
 155 }
 156
 157 /*
 158  * Description:
 159  *      Handle received fragment packet
 160  *
 161  * Parameters:
 162  *  In:
 163  *      pDevice         - Pointer to adapter
 164  *      pMACHeader      - 802.11 MAC Header of received packet
 165  *      cbFrameLength   - Frame length
 166  *      bWEP            - is WEP packet
 167  *  Out:
 168  *      none
 169  *
 170  * Return Value: true if it is valid fragment packet and we have resource to defragment; otherwise false
 171  *
 172  */
 173 bool WCTLbHandleFragment(struct vnt_private *pDevice, struct ieee80211_hdr *pMACHeader, unsigned int cbFrameLength, bool bWEP, bool bExtIV)
 174 {
 175         unsigned int uHeaderSize;
 176
 177     if (bWEP == true) {
 178         uHeaderSize = 28;
 179         if (bExtIV)
 180         // ExtIV
 181             uHeaderSize +=4;
 182     }
 183     else {
 184         uHeaderSize = 24;
 185     }
 186
 187     if (IS_FIRST_FRAGMENT_PKT(pMACHeader)) {
 188         pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 189         if (pDevice->uCurrentDFCBIdx < pDevice->cbDFCB) {
 190             // duplicate, we must flush previous DCB
 191             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].uLifetime = pDevice->dwMaxReceiveLifetime;
 192             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence = (pMACHeader->seq_ctrl >> 4);
 193             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum = (pMACHeader->seq_ctrl & 0x000F);
 194         }
 195         else {
 196             pDevice->uCurrentDFCBIdx = WCTLuInsertDFCB(pDevice, pMACHeader);
 197             if (pDevice->uCurrentDFCBIdx == pDevice->cbDFCB) {
 198                 return(false);
 199             }
 200         }
 201         // reserve 8 byte to match MAC RX Buffer
 202         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer = (u8 *) (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].skb->data + 8);
 203 //        pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer = (u8 *) (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].skb->data + 4);
 204         memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, pMACHeader, cbFrameLength);
 205         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength = cbFrameLength;
 206         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += cbFrameLength;
 207         pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 208         //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "First pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 209         return(false);
 210     }
 211     else {
 212         pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
 213         if (pDevice->uCurrentDFCBIdx != pDevice->cbDFCB) {
 214             if ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence == (pMACHeader->seq_ctrl >> 4)) &&
 215                 (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum == (pMACHeader->seq_ctrl & 0x000F)) &&
 216                 ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength + cbFrameLength - uHeaderSize) < 2346)) {
 217
 218                 memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, ((u8 *) (pMACHeader) + uHeaderSize), (cbFrameLength - uHeaderSize));
 219                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength += (cbFrameLength - uHeaderSize);
 220                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += (cbFrameLength - uHeaderSize);
 221                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
 222                 //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Second pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 223             }
 224             else {
 225                 // seq error or frag # error flush DFCB
 226                 pDevice->cbFreeDFCB++;
 227                 pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 228                 return(false);
 229             }
 230         }
 231         else {
 232             return(false);
 233         }
 234         if (IS_LAST_FRAGMENT_PKT(pMACHeader)) {
 235             //enq defragcontrolblock
 236             pDevice->cbFreeDFCB++;
 237             pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
 238             //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Last pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
 239             return(true);
 240         }
 241         return(false);
 242     }
 243 }
 244