linux/lib/crc-ccitt.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *	linux/lib/crc-ccitt.c
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/crc-ccitt.h>

/*
 * This mysterious table is just the CRC of each possible byte. It can be
 * computed using the standard bit-at-a-time methods. The polynomial can
 * be seen in entry 128, 0x8408. This corresponds to x^0 + x^5 + x^12.
 * Add the implicit x^16, and you have the standard CRC-CCITT.
 */
u16 const crc_ccitt_table[256] = …;
EXPORT_SYMBOL(…);

/**
 *	crc_ccitt - recompute the CRC (CRC-CCITT variant) for the data
 *	buffer
 *	@crc: previous CRC value
 *	@buffer: data pointer
 *	@len: number of bytes in the buffer
 */
u16 crc_ccitt(u16 crc, u8 const *buffer, size_t len)
{ … }
EXPORT_SYMBOL(…);

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;