| Harald Welte | f5e7264 | 2022-10-30 22:20:55 +0100 | [diff] [blame] | 1 | /** |
| 2 | * \file |
| 3 | * Functions and types for CRC checks. |
| 4 | * |
| 5 | * Generated on Sat May 12 09:41:12 2018 |
| 6 | * by pycrc v0.9.1, https://pycrc.org |
| 7 | * using the configuration: |
| 8 | * - Width = 4 |
| 9 | * - Poly = 0x3 |
| 10 | * - XorIn = 0x0 |
| 11 | * - ReflectIn = False |
| 12 | * - XorOut = 0x0 |
| 13 | * - ReflectOut = False |
| 14 | * - Algorithm = table-driven |
| 15 | * |
| 16 | * This file defines the functions crc4itu_init(), crc4itu_update() and crc_finalize(). |
| 17 | * |
| 18 | * The crc4itu_init() function returns the initial \c crc value and must be called |
| 19 | * before the first call to crc4itu_update(). |
| 20 | * Similarly, the crc_finalize() function must be called after the last call |
| 21 | * to crc4itu_update(), before the \c crc is being used. |
| 22 | * is being used. |
| 23 | * |
| 24 | * The crc4itu_update() function can be called any number of times (including zero |
| 25 | * times) in between the crc4itu_init() and crc_finalize() calls. |
| 26 | * |
| 27 | * This pseudo-code shows an example usage of the API: |
| 28 | * \code{.c} |
| 29 | * crc_t crc; |
| 30 | * unsigned char data[MAX_DATA_LEN]; |
| 31 | * size_t data_len; |
| 32 | * |
| 33 | * crc = crc4itu_init(); |
| 34 | * while ((data_len = read_data(data, MAX_DATA_LEN)) > 0) { |
| 35 | * crc = crc4itu_update(crc, data, data_len); |
| 36 | * } |
| 37 | * crc = crc_finalize(crc); |
| 38 | * \endcode |
| 39 | */ |
| 40 | #ifndef CRC4ITU_H |
| 41 | #define CRC4ITU_H |
| 42 | |
| 43 | #include <stdlib.h> |
| 44 | #include <stdint.h> |
| 45 | |
| 46 | #ifdef __cplusplus |
| 47 | extern "C" { |
| 48 | #endif |
| 49 | |
| 50 | |
| 51 | /** |
| 52 | * The definition of the used algorithm. |
| 53 | * |
| 54 | * This is not used anywhere in the generated code, but it may be used by the |
| 55 | * application code to call algorithm-specific code, if desired. |
| 56 | */ |
| 57 | #define CRC_ALGO_TABLE_DRIVEN 1 |
| 58 | |
| 59 | |
| 60 | /** |
| 61 | * The type of the CRC values. |
| 62 | * |
| 63 | * This type must be big enough to contain at least 4 bits. |
| 64 | */ |
| 65 | typedef uint_fast8_t crc_t; |
| 66 | |
| 67 | |
| 68 | /** |
| 69 | * Calculate the initial crc value. |
| 70 | * |
| 71 | * \return The initial crc value. |
| 72 | */ |
| 73 | static inline crc_t crc4itu_init(void) |
| 74 | { |
| 75 | return 0x0; |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /** |
| 80 | * Update the crc value with new data. |
| 81 | * |
| 82 | * \param[in] crc The current crc value. |
| 83 | * \param[in] data Pointer to a buffer of \a data_len bytes. |
| 84 | * \param[in] data_len Number of bytes in the \a data buffer. |
| 85 | * \return The updated crc value. |
| 86 | */ |
| 87 | crc_t crc4itu_update(crc_t crc, const void *data, size_t data_len); |
| 88 | |
| 89 | |
| 90 | /** |
| 91 | * Calculate the final crc value. |
| 92 | * |
| 93 | * \param[in] crc The current crc value. |
| 94 | * \return The final crc value. |
| 95 | */ |
| 96 | static inline crc_t crc_finalize(crc_t crc) |
| 97 | { |
| 98 | return crc; |
| 99 | } |
| 100 | |
| 101 | |
| 102 | #ifdef __cplusplus |
| 103 | } /* closing brace for extern "C" */ |
| 104 | #endif |
| 105 | |
| 106 | #endif /* CRC4ITU_H */ |