Forest Bond | 5449c68 | 2009-04-25 10:30:44 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2003 VIA Networking, Inc. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | * |
| 18 | * |
| 19 | * File: tether.c |
| 20 | * |
| 21 | * Purpose: |
| 22 | * |
| 23 | * Author: Tevin Chen |
| 24 | * |
| 25 | * Date: May 21, 1996 |
| 26 | * |
| 27 | * Functions: |
| 28 | * ETHbyGetHashIndexByCrc32 - Caculate multicast hash value by CRC32 |
| 29 | * ETHbIsBufferCrc32Ok - Check CRC value of the buffer if Ok or not |
| 30 | * |
| 31 | * Revision History: |
| 32 | * |
| 33 | */ |
| 34 | |
| 35 | #if !defined(__DEVICE_H__) |
| 36 | #include "device.h" |
| 37 | #endif |
| 38 | #if !defined(__TMACRO_H__) |
| 39 | #include "tmacro.h" |
| 40 | #endif |
| 41 | #if !defined(__TBIT_H__) |
| 42 | #include "tbit.h" |
| 43 | #endif |
| 44 | #if !defined(__TCRC_H__) |
| 45 | #include "tcrc.h" |
| 46 | #endif |
| 47 | #if !defined(__TETHER_H__) |
| 48 | #include "tether.h" |
| 49 | #endif |
| 50 | |
| 51 | |
| 52 | |
| 53 | |
| 54 | /*--------------------- Static Definitions -------------------------*/ |
| 55 | |
| 56 | /*--------------------- Static Classes ----------------------------*/ |
| 57 | |
| 58 | /*--------------------- Static Variables --------------------------*/ |
| 59 | |
| 60 | /*--------------------- Static Functions --------------------------*/ |
| 61 | |
| 62 | /*--------------------- Export Variables --------------------------*/ |
| 63 | |
| 64 | |
| 65 | |
| 66 | /* |
| 67 | * Description: Caculate multicast hash value by CRC32 |
| 68 | * |
| 69 | * Parameters: |
| 70 | * In: |
| 71 | * pbyMultiAddr - Multicast Address |
| 72 | * Out: |
| 73 | * none |
| 74 | * |
| 75 | * Return Value: Hash value |
| 76 | * |
| 77 | */ |
| 78 | BYTE ETHbyGetHashIndexByCrc32 (PBYTE pbyMultiAddr) |
| 79 | { |
| 80 | int ii; |
| 81 | BYTE byTmpHash; |
| 82 | BYTE byHash = 0; |
| 83 | |
| 84 | // get the least 6-bits from CRC generator |
| 85 | byTmpHash = (BYTE)(CRCdwCrc32(pbyMultiAddr, U_ETHER_ADDR_LEN, |
| 86 | 0xFFFFFFFFL) & 0x3F); |
| 87 | // reverse most bit to least bit |
| 88 | for (ii = 0; ii < (sizeof(byTmpHash) * 8); ii++) { |
| 89 | byHash <<= 1; |
| 90 | if (BITbIsBitOn(byTmpHash, 0x01)) |
| 91 | byHash |= 1; |
| 92 | byTmpHash >>= 1; |
| 93 | } |
| 94 | |
| 95 | // adjust 6-bits to the right most |
| 96 | return (byHash >> 2); |
| 97 | } |
| 98 | |
| 99 | |
| 100 | /* |
| 101 | * Description: Check CRC value of the buffer if Ok or not |
| 102 | * |
| 103 | * Parameters: |
| 104 | * In: |
| 105 | * pbyBuffer - pointer of buffer (normally is rx buffer) |
| 106 | * cbFrameLength - length of buffer, including CRC portion |
| 107 | * Out: |
| 108 | * none |
| 109 | * |
| 110 | * Return Value: TRUE if ok; FALSE if error. |
| 111 | * |
| 112 | */ |
| 113 | BOOL ETHbIsBufferCrc32Ok (PBYTE pbyBuffer, UINT cbFrameLength) |
| 114 | { |
| 115 | DWORD dwCRC; |
| 116 | |
| 117 | dwCRC = CRCdwGetCrc32(pbyBuffer, cbFrameLength - 4); |
| 118 | if (cpu_to_le32(*((PDWORD)(pbyBuffer + cbFrameLength - 4))) != dwCRC) { |
| 119 | return FALSE; |
| 120 | } |
| 121 | return TRUE; |
| 122 | } |
| 123 | |