109 lines
2.6 KiB
C
109 lines
2.6 KiB
C
/*
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* Copyright (c) 2003 VIA Networking, Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*
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* File: tether.c
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*
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* Purpose:
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*
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* Author: Tevin Chen
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*
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* Date: May 21, 1996
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*
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* Functions:
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* ETHbyGetHashIndexByCrc32 - Caculate multicast hash value by CRC32
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* ETHbIsBufferCrc32Ok - Check CRC value of the buffer if Ok or not
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*
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* Revision History:
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*
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*/
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#include "device.h"
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#include "tmacro.h"
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#include "tcrc.h"
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#include "tether.h"
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/*--------------------- Static Definitions -------------------------*/
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/*--------------------- Static Classes ----------------------------*/
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/*--------------------- Static Variables --------------------------*/
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/*--------------------- Static Functions --------------------------*/
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/*--------------------- Export Variables --------------------------*/
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/*
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* Description: Caculate multicast hash value by CRC32
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*
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* Parameters:
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* In:
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* pbyMultiAddr - Multicast Address
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* Out:
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* none
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*
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* Return Value: Hash value
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*
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*/
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BYTE ETHbyGetHashIndexByCrc32(PBYTE pbyMultiAddr)
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{
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int ii;
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BYTE byTmpHash;
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BYTE byHash = 0;
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/* get the least 6-bits from CRC generator */
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byTmpHash = (BYTE)(CRCdwCrc32(pbyMultiAddr, ETH_ALEN,
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0xFFFFFFFFL) & 0x3F);
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/* reverse most bit to least bit */
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for (ii = 0; ii < (sizeof(byTmpHash) * 8); ii++) {
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byHash <<= 1;
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if (byTmpHash & 0x01)
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byHash |= 1;
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byTmpHash >>= 1;
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}
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/* adjust 6-bits to the right most */
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return byHash >> 2;
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}
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/*
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* Description: Check CRC value of the buffer if Ok or not
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*
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* Parameters:
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* In:
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* pbyBuffer - pointer of buffer (normally is rx buffer)
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* cbFrameLength - length of buffer, including CRC portion
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* Out:
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* none
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*
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* Return Value: TRUE if ok; FALSE if error.
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*
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*/
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BOOL ETHbIsBufferCrc32Ok(PBYTE pbyBuffer, UINT cbFrameLength)
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{
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DWORD dwCRC;
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dwCRC = CRCdwGetCrc32(pbyBuffer, cbFrameLength - 4);
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if (cpu_to_le32(*((PDWORD)(pbyBuffer + cbFrameLength - 4))) != dwCRC)
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return FALSE;
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return TRUE;
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}
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