include/qemu/crc-ccitt.h

   1 /*
   2  * CRC16 (CCITT) Checksum Algorithm
   3  *
   4  * Copyright (c) 2021 Wind River Systems, Inc.
   5  *
   6  * Author:
   7  *   Bin Meng <bin.meng@windriver.com>
   8  *
   9  * From Linux kernel v5.10 include/linux/crc-ccitt.h
  10  *
  11  * SPDX-License-Identifier: GPL-2.0
  12  */
  13
  14 #ifndef _CRC_CCITT_H
  15 #define _CRC_CCITT_H
  16
  17 extern uint16_t const crc_ccitt_table[256];
  18 extern uint16_t const crc_ccitt_false_table[256];
  19
  20 extern uint16_t crc_ccitt(uint16_t crc, const uint8_t *buffer, size_t len);
  21 extern uint16_t crc_ccitt_false(uint16_t crc, const uint8_t *buffer, size_t len);
  22
  23 static inline uint16_t crc_ccitt_byte(uint16_t crc, const uint8_t c)
  24 {
  25     return (crc >> 8) ^ crc_ccitt_table[(crc ^ c) & 0xff];
  26 }
  27
  28 static inline uint16_t crc_ccitt_false_byte(uint16_t crc, const uint8_t c)
  29 {
  30     return (crc << 8) ^ crc_ccitt_false_table[(crc >> 8) ^ c];
  31 }
  32
  33 #endif /* _CRC_CCITT_H */