| /* |
| * Copyright (c) 2020, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * This file includes definitions for checksum calculation. |
| */ |
| |
| #ifndef CHECKSUM_HPP_ |
| #define CHECKSUM_HPP_ |
| |
| #include "openthread-core-config.h" |
| |
| #include <stdint.h> |
| |
| #include "common/message.hpp" |
| #include "net/ip6_address.hpp" |
| #include "net/ip6_headers.hpp" |
| #include "net/socket.hpp" |
| |
| namespace ot { |
| |
| /** |
| * This class implements IP checksum calculation and verification. |
| * |
| */ |
| class Checksum |
| { |
| friend class ChecksumTester; |
| |
| public: |
| /** |
| * This static method verifies the checksum in a given message (if UDP/ICMP6). |
| * |
| * @param[in] aMessage The message to verify its checksum. The `aMessage.GetOffset()` should point to start |
| * UDP/ICMP6 header. |
| * @param[in] aMessageInfo The message info associated with @p aMessage. |
| * @param[in] aIpProto The Internet Protocol value. |
| * |
| * @retval kErrorNone The checksum is valid if UDP/ICMP6 protocol, or not a UDP/ICMP6 protocol. |
| * @retval kErrorDrop The check is not valid and message should be dropped. |
| * |
| */ |
| static Error VerifyMessageChecksum(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo, uint8_t aIpProto); |
| |
| /** |
| * This static method calculates and then updates the checksum in a given message (if UDP/ICMP6). |
| * |
| * @param[in,out] aMessage The message to update the checksum in. The `aMessage.GetOffset()` should point to start |
| * of the UDP/ICMP6 header. On exit the checksum field in UDP/ICMP6 header in the message |
| * is updated. |
| * @param[in] aSource The source address. |
| * @param[in] aDestination The destination address. |
| * @param[in] aIpProto The Internet Protocol value. |
| * |
| */ |
| static void UpdateMessageChecksum(Message & aMessage, |
| const Ip6::Address &aSource, |
| const Ip6::Address &aDestination, |
| uint8_t aIpProto); |
| |
| private: |
| Checksum(void) |
| : mValue(0) |
| , mAtOddIndex(false) |
| { |
| } |
| |
| uint16_t GetValue(void) const { return mValue; } |
| void AddUint8(uint8_t aUint8); |
| void AddUint16(uint16_t aUint16); |
| void AddData(const uint8_t *aBuffer, uint16_t aLength); |
| void WriteToMessage(uint16_t aOffset, Message &aMessage) const; |
| void Calculate(const Ip6::Address &aSource, |
| const Ip6::Address &aDestination, |
| uint8_t aIpProto, |
| const Message & aMessage); |
| |
| static constexpr uint16_t kValidRxChecksum = 0xffff; |
| |
| uint16_t mValue; |
| bool mAtOddIndex; |
| }; |
| |
| } // namespace ot |
| |
| #endif // CHECKSUM_HPP_ |