1 /* 2 * Copyright (c) 2016, The OpenThread Authors. 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 are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Neither the name of the copyright holder nor the 13 * names of its contributors may be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /** 30 * @file 31 * This file includes definitions for CRC16 computations. 32 */ 33 34 #ifndef OTBR_UTILS_CRC16_HPP_ 35 #define OTBR_UTILS_CRC16_HPP_ 36 37 #include "openthread-br/config.h" 38 39 #include <stdint.h> 40 41 namespace otbr { 42 43 /** 44 * This class implements CRC16 computations. 45 */ 46 class Crc16 47 { 48 public: 49 enum Polynomial 50 { 51 kCcitt = 0x1021, ///< CRC16_CCITT 52 kAnsi = 0x8005, ///< CRC16-ANSI 53 }; 54 55 /** 56 * This constructor initializes the object. 57 * 58 * @param[in] aPolynomial The polynomial value. 59 */ 60 Crc16(Polynomial aPolynomial); 61 62 /** 63 * This method initializes the CRC16 computation. 64 */ Init(void)65 void Init(void) { mCrc = 0; } 66 67 /** 68 * This method feeds a byte value into the CRC16 computation. 69 * 70 * @param[in] aByte The byte value. 71 */ 72 void Update(uint8_t aByte); 73 74 /** 75 * This method gets the current CRC16 value. 76 * 77 * @returns The current CRC16 value. 78 */ Get(void) const79 uint16_t Get(void) const { return mCrc; } 80 81 private: 82 uint16_t mPolynomial; 83 uint16_t mCrc; 84 }; 85 86 } // namespace otbr 87 88 #endif // OTBR_UTILS_CRC16_HPP_ 89