| /* |
| * Copyright (c) 2017, The Linux Foundation. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * * Neither the name of The Linux Foundation nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS |
| * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE |
| * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN |
| * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "wlct_os.h" |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include "CCRC32.h" |
| |
| CCRC32::CCRC32(void) |
| { |
| int index = 0; |
| while (index <= BYTE_MASK) |
| { |
| lookup[index] = Reflect(index, 8); |
| lookup[index] = lookup[index] << 24; |
| |
| // Repeat 8 times |
| int subindex = 0; |
| while(subindex < 8) |
| { |
| subindex++; |
| |
| int check; |
| if (lookup[index] & (1 << 31)) |
| { |
| check = POLYNOMIAL; |
| } |
| else |
| { |
| check = 0; |
| } |
| |
| lookup[index] = (lookup[index] << 1); |
| lookup[index] = lookup[index] ^ check; |
| } |
| |
| lookup[index] = Reflect(lookup[index], 32); |
| index++; |
| } |
| } |
| |
| uint32_t CCRC32::Reflect(uint32_t reflected, const char bitsToReflect) |
| { |
| uint32_t retVal = 0; |
| |
| int index = 1; |
| |
| while(index < (bitsToReflect + 1)) |
| { |
| if((reflected % 2) == 1) |
| { |
| retVal |= (1 << (bitsToReflect - index)); |
| } |
| else |
| { |
| // do nothing |
| } |
| reflected >>= 1; |
| index++; |
| } |
| |
| return retVal; |
| } |
| |
| void CCRC32::CalcCRCStep(uint32_t *crc, const unsigned char *data, uint32_t length) |
| { |
| uint32_t tempCRC = *crc; |
| |
| for (uint32_t index = 0; index < length; index++) |
| { |
| tempCRC = (tempCRC >> 8) ^ lookup[(tempCRC & BYTE_MASK) ^ *data++]; |
| } |
| |
| *crc = tempCRC; |
| } |
| |
| uint32_t CCRC32::CalcCRC(const unsigned char *data, uint32_t length) |
| { |
| uint32_t crc = CRC_MASK; |
| CalcCRCStep(&crc, data, length); |
| return(crc ^ CRC_MASK); |
| } |