[175] | 1 | /*
|
---|
| 2 | * Copyright (c) 2005, Swedish Institute of Computer Science
|
---|
| 3 | * All rights reserved.
|
---|
| 4 | *
|
---|
| 5 | * Redistribution and use in source and binary forms, with or without
|
---|
| 6 | * modification, are permitted provided that the following conditions
|
---|
| 7 | * are met:
|
---|
| 8 | * 1. Redistributions of source code must retain the above copyright
|
---|
| 9 | * notice, this list of conditions and the following disclaimer.
|
---|
| 10 | * 2. Redistributions in binary form must reproduce the above copyright
|
---|
| 11 | * notice, this list of conditions and the following disclaimer in the
|
---|
| 12 | * documentation and/or other materials provided with the distribution.
|
---|
| 13 | * 3. Neither the name of the Institute nor the names of its contributors
|
---|
| 14 | * may be used to endorse or promote products derived from this software
|
---|
| 15 | * without specific prior written permission.
|
---|
| 16 | *
|
---|
| 17 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
---|
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
---|
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
---|
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
---|
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
---|
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
---|
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
---|
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
---|
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
---|
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
---|
| 27 | * SUCH DAMAGE.
|
---|
| 28 | *
|
---|
| 29 | * This file is part of the Contiki operating system.
|
---|
| 30 | *
|
---|
| 31 | */
|
---|
| 32 |
|
---|
| 33 | /**
|
---|
| 34 | * \file
|
---|
| 35 | * Header file for the CRC16 calculcation
|
---|
| 36 | * \author
|
---|
| 37 | * Adam Dunkels <adam@sics.se>
|
---|
| 38 | *
|
---|
| 39 | */
|
---|
| 40 |
|
---|
| 41 | /** \addtogroup lib
|
---|
| 42 | * @{ */
|
---|
| 43 |
|
---|
| 44 | /**
|
---|
| 45 | * \defgroup crc16 Cyclic Redundancy Check 16 (CRC16) calculation
|
---|
| 46 | *
|
---|
| 47 | * The Cyclic Redundancy Check 16 is a hash function that produces a
|
---|
| 48 | * checksum that is used to detect errors in transmissions. The CRC16
|
---|
| 49 | * calculation module is an iterative CRC calculator that can be used
|
---|
| 50 | * to cumulatively update a CRC checksum for every incoming byte.
|
---|
| 51 | *
|
---|
| 52 | * @{
|
---|
| 53 | */
|
---|
| 54 |
|
---|
| 55 | #ifndef CRC16_H_
|
---|
| 56 | #define CRC16_H_
|
---|
| 57 | #ifdef __cplusplus
|
---|
| 58 | extern "C" {
|
---|
| 59 | #endif
|
---|
| 60 | /**
|
---|
| 61 | * \brief Update an accumulated CRC16 checksum with one byte.
|
---|
| 62 | * \param b The byte to be added to the checksum
|
---|
| 63 | * \param crc The accumulated CRC that is to be updated.
|
---|
| 64 | * \return The updated CRC checksum.
|
---|
| 65 | *
|
---|
| 66 | * This function updates an accumulated CRC16 checksum
|
---|
| 67 | * with one byte. It can be used as a running checksum, or
|
---|
| 68 | * to checksum an entire data block.
|
---|
| 69 | *
|
---|
| 70 | * \note The algorithm used in this implementation is
|
---|
| 71 | * tailored for a running checksum and does not perform as
|
---|
| 72 | * well as a table-driven algorithm when checksumming an
|
---|
| 73 | * entire data block.
|
---|
| 74 | *
|
---|
| 75 | */
|
---|
| 76 | unsigned short crc16_add(unsigned char b, unsigned short crc);
|
---|
| 77 |
|
---|
| 78 | /**
|
---|
| 79 | * \brief Calculate the CRC16 over a data area
|
---|
| 80 | * \param data Pointer to the data
|
---|
| 81 | * \param datalen The length of the data
|
---|
| 82 | * \param acc The accumulated CRC that is to be updated (or zero).
|
---|
| 83 | * \return The CRC16 checksum.
|
---|
| 84 | *
|
---|
| 85 | * This function calculates the CRC16 checksum of a data area.
|
---|
| 86 | *
|
---|
| 87 | * \note The algorithm used in this implementation is
|
---|
| 88 | * tailored for a running checksum and does not perform as
|
---|
| 89 | * well as a table-driven algorithm when checksumming an
|
---|
| 90 | * entire data block.
|
---|
| 91 | */
|
---|
| 92 | unsigned short crc16_data(const unsigned char *data, int datalen,
|
---|
| 93 | unsigned short acc);
|
---|
| 94 | #ifdef __cplusplus
|
---|
| 95 | }
|
---|
| 96 | #endif
|
---|
| 97 | #endif /* CRC16_H_ */
|
---|
| 98 |
|
---|
| 99 | /** @} */
|
---|
| 100 | /** @} */
|
---|