libosmocore/include/osmocom/core/crc16.h

44 lines
1.1 KiB
C

/*! \file crc16.h
* This was copied from the linux kernel and adjusted for our types.
*/
/*
* crc16.h - CRC-16 routine
*
* Implements the standard CRC-16:
* Width 16
* Poly 0x8005 (x^16 + x^15 + x^2 + 1)
* Init 0
*
* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#pragma once
#include <stdint.h>
#include <sys/types.h>
extern uint16_t const osmo_crc16_table[256];
extern uint16_t osmo_crc16(uint16_t crc, const uint8_t *buffer, size_t len);
static inline uint16_t osmo_crc16_byte(uint16_t crc, const uint8_t data)
{
return (crc >> 8) ^ osmo_crc16_table[(crc ^ data) & 0xff];
}
/* CCITT polynome 0x8408. This corresponds to x^0 + x^5 + x^12 */
extern uint16_t const osmo_crc16_ccitt_table[256];
extern uint16_t osmo_crc16_ccitt(uint16_t crc, const uint8_t *buffer, size_t len);
static inline uint16_t osmo_crc16_ccitt_byte(uint16_t crc, const uint8_t data)
{
return (crc >> 8) ^ osmo_crc16_ccitt_table[(crc ^ data) & 0xff];
}