/*
 * Library: libcrc
 * File:    include/checksum.h
 * Author:  Lammert Bies
 *
 * This file is licensed under the MIT License as stated below
 *
 * Copyright (c) 1999-2018 Lammert Bies
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Description
 * -----------
 * The headerfile include/checksum.h contains the definitions and prototypes
 * for routines that can be used to calculate several kinds of checksums.
 */

#ifndef DEF_LIBCRC_CHECKSUM_H
#define DEF_LIBCRC_CHECKSUM_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <stdint.h>

/*
 * #define CRC_POLY_xxxx
 *
 * The constants of the form CRC_POLY_xxxx define the polynomials for some well
 * known CRC calculations.
 */

#define CRC_POLY_16 0xA001
#define CRC_POLY_32 0xEDB88320ul
#define CRC_POLY_64 0x42F0E1EBA9EA3693ull
#define CRC_POLY_CCITT 0x1021
#define CRC_POLY_DNP 0xA6BC
#define CRC_POLY_KERMIT 0x8408
#define CRC_POLY_SICK 0x8005

/*
 * #define CRC_START_xxxx
 *
 * The constants of the form CRC_START_xxxx define the values that are used for
 * initialization of a CRC value for common used calculation methods.
 */

#define CRC_START_8 0x00
#define CRC_START_16 0x0000
#define CRC_START_MODBUS 0xFFFF
#define CRC_START_XMODEM 0x0000
#define CRC_START_CCITT_1D0F 0x1D0F
#define CRC_START_CCITT_FFFF 0xFFFF
#define CRC_START_KERMIT 0x0000
#define CRC_START_SICK 0x0000
#define CRC_START_DNP 0x0000
#define CRC_START_32 0xFFFFFFFFul
#define CRC_START_64_ECMA 0x0000000000000000ull
#define CRC_START_64_WE 0xFFFFFFFFFFFFFFFFull

/*
 * Prototype list of global functions
 */

unsigned char* checksum_NMEA(const unsigned char* input_str, unsigned char* result);
uint8_t crc_8(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_16(const unsigned char* input_str, size_t num_bytes);
uint32_t crc_32(const unsigned char* input_str, size_t num_bytes);
uint64_t crc_64_ecma(const unsigned char* input_str, size_t num_bytes);
uint64_t crc_64_we(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_ccitt_1d0f(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_ccitt_ffff(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_dnp(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_kermit(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_modbus(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_sick(const unsigned char* input_str, size_t num_bytes);
uint16_t crc_xmodem(const unsigned char* input_str, size_t num_bytes);
uint8_t update_crc_8(uint8_t crc, unsigned char c);
uint16_t update_crc_16(uint16_t crc, unsigned char c);
uint32_t update_crc_32(uint32_t crc, unsigned char c);
uint64_t update_crc_64_ecma(uint64_t crc, unsigned char c);
uint16_t update_crc_ccitt(uint16_t crc, unsigned char c);
uint16_t update_crc_dnp(uint16_t crc, unsigned char c);
uint16_t update_crc_kermit(uint16_t crc, unsigned char c);
uint16_t update_crc_sick(uint16_t crc, unsigned char c, unsigned char prev_byte);

/*
 * Global CRC lookup tables
 */

extern const uint32_t crc_tab32[];
extern const uint64_t crc_tab64[];

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  // DEF_LIBCRC_CHECKSUM_H