Modbus.h

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/* Copyright 2013-2019 Homegear GmbH
 *
 * Homegear is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Homegear is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Homegear.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU Lesser General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
*/

#ifndef LIBHOMEGEAR_BASE_MODBUS_H
#define LIBHOMEGEAR_BASE_MODBUS_H

#include "../Exception.h"
#include "TcpSocket.h"

namespace BaseLib
{

class ModbusException : public Exception
{
public:
    ModbusException(const std::string& message) : Exception(message) {}
    ModbusException(const std::string& message, uint8_t code, std::vector<char> packet) : Exception(message), _code(code), _packet(std::move(packet)) {}

    uint8_t getCode() const { return _code; }
    std::vector<char> getPacket() const { return _packet; }
private:
    uint8_t _code = 0;
    std::vector<char> _packet;
};

class ModbusServerBusyException : public ModbusException
{
public:
    ModbusServerBusyException(std::string message) : ModbusException(message) {}
    ModbusServerBusyException(std::string message, uint8_t code, std::vector<char> packet) : ModbusException(message, code, packet) {}
};

class Modbus
{
public:
    struct ModbusInfo
    {
        std::string hostname;
        int32_t port = 502;
        bool useSsl = false;
        bool keepAlive = true;
        std::string certFile;
        std::string certData;
        std::string keyFile;
        std::shared_ptr<Security::SecureVector<uint8_t>> keyData;
        bool verifyCertificate = true;
        std::string caFile; //For client certificate verification
        std::string caData; //For client certificate verification
        uint32_t timeout = 5000;
    };

    struct DeviceInfo
    {
        std::string vendorName;
        std::string productCode;
        std::string majorMinorRevision;
        std::string vendorUrl;
        std::string productName;
        std::string modelName;
        std::string userApplicationName;
        std::map<uint8_t, std::vector<uint8_t>> objects;
    };

    Modbus(BaseLib::SharedObjects* baseLib, ModbusInfo& serverInfo);

    virtual ~Modbus();

    void setSlaveId(uint8_t value) { _slaveId = value; }

    void setDebug(bool value) { _debug = value; }

    void connect();

    void disconnect();

    bool isConnected() { return _socket && _socket->connected(); }

    void readCoils(uint16_t startingAddress, std::vector<uint8_t>& buffer, uint16_t coilCount);

    void readDiscreteInputs(uint16_t startingAddress, std::vector<uint8_t>& buffer, uint16_t inputCount);

    void readHoldingRegisters(uint16_t startingAddress, std::vector<uint16_t>& buffer, uint16_t registerCount);

    void readInputRegisters(uint16_t startingAddress, std::vector<uint16_t>& buffer, uint16_t registerCount);

    void writeSingleCoil(uint16_t address, bool value);

    void writeSingleRegister(uint16_t address, uint16_t value);

    void writeMultipleCoils(uint16_t startAddress, const std::vector<uint8_t>& values, uint16_t coilCount);

    void writeMultipleRegisters(uint16_t startAddress, const std::vector<uint16_t>& values, uint16_t registerCount);

    void readWriteMultipleRegisters(uint16_t readStartAddress, std::vector<uint16_t>& readBuffer, uint16_t readRegisterCount, uint16_t writeStartAddress, const std::vector<uint16_t>& writeValues, uint16_t writeRegisterCount);

    DeviceInfo readDeviceIdentification();
private:
    static const uint8_t _reverseByteMask[256];

    uint8_t _slaveId = 0xFF;

    bool _debug = false;

    bool _keepAlive = true;

    BaseLib::SharedObjects* _bl = nullptr;

    std::mutex _socketMutex;

    std::unique_ptr<TcpSocket> _socket;

    std::string _hostname;

    int32_t _port = 502;

    std::unique_ptr<std::vector<char>> _readBuffer;

    uint16_t _transactionId = 0;

    void insertHeader(std::vector<char>& packet, uint8_t functionCode, uint16_t payloadSize);

    std::vector<char> getResponse(std::vector<char>& packet);
};

}

#endif