eive-obsw/mission/devices/PlocHandler.h

#ifndef MISSION_DEVICES_PLOCHANDLER_H_
#define MISSION_DEVICES_PLOCHANDLER_H_

#include <fsfw/devicehandlers/DeviceHandlerBase.h>
#include <mission/devices/devicedefinitions/PlocDefinitions.h>
#include <cstring>

/**
 * @brief	This is the device handler for the PLOC.
 *
 * @details
 * The PLOC uses the space packet protocol for communication. To each command the PLOC
 * answers with at least one acknowledgment and one execution report.
 * Flight manual:
 * https://egit.irs.uni-stuttgart.de/redmine/projects/eive-flight-manual/wiki/PLOC_Commands
 * @author	J. Meier
 */
class PlocHandler: public DeviceHandlerBase {
public:

    PlocHandler(object_id_t objectId, object_id_t comIF, CookieIF * comCookie);
	virtual ~PlocHandler();

	/**
     * @brief   Sets mode to MODE_NORMAL. Can be used for debugging.
     */
    void setModeNormal();

protected:
	void doStartUp() override;
	void doShutDown() override;
	ReturnValue_t buildNormalDeviceCommand(DeviceCommandId_t * id) override;
	ReturnValue_t buildTransitionDeviceCommand(DeviceCommandId_t * id) override;
	void fillCommandAndReplyMap() override;
	ReturnValue_t buildCommandFromCommand(DeviceCommandId_t deviceCommand,
				const uint8_t * commandData,size_t commandDataLen) override;
	ReturnValue_t scanForReply(const uint8_t *start, size_t remainingSize,
			DeviceCommandId_t *foundId, size_t *foundLen) override;
	ReturnValue_t interpretDeviceReply(DeviceCommandId_t id,
			const uint8_t *packet) override;
	void setNormalDatapoolEntriesInvalid() override;
	uint32_t getTransitionDelayMs(Mode_t modeFrom, Mode_t modeTo) override;
	ReturnValue_t initializeLocalDataPool(localpool::DataPool& localDataPoolMap,
            LocalDataPoolManager& poolManager) override;
	ReturnValue_t enableReplyInReplyMap(DeviceCommandMap::iterator command,
	            uint8_t expectedReplies = 1, bool useAlternateId = false,
	            DeviceCommandId_t alternateReplyID = 0) override;
	size_t getNextReplyLength(DeviceCommandId_t deviceCommand) override;

private:

    static const uint8_t INTERFACE_ID = CLASS_ID::PLOC_HANDLER;

    static const ReturnValue_t CRC_FAILURE = MAKE_RETURN_CODE(0xA0); //!> Space Packet received from PLOC has invalid CRC
    static const ReturnValue_t RECEIVED_ACK_FAILURE = MAKE_RETURN_CODE(0xA1); //!> Received ACK failure reply from PLOC
    static const ReturnValue_t RECEIVED_EXE_FAILURE = MAKE_RETURN_CODE(0xA2); //!> Received execution failure reply from PLOC
    static const ReturnValue_t INVALID_APID = MAKE_RETURN_CODE(0xA3); //!> Received space packet with invalid APID from PLOC

    static const uint8_t SUBSYSTEM_ID = SUBSYSTEM_ID::PLOC_HANDLER;

    static const Event MEMORY_READ_RPT_CRC_FAILURE = MAKE_EVENT(1, severity::LOW); //!> PLOC crc failure in telemetry packet
    static const Event ACK_FAILURE = MAKE_EVENT(2, severity::LOW); //!> PLOC receive acknowledgment failure report
    static const Event EXE_FAILURE = MAKE_EVENT(3, severity::LOW); //!> PLOC receive execution failure report
    static const Event CRC_FAILURE_EVENT = MAKE_EVENT(4, severity::LOW); //!> PLOC reply has invalid crc

    static const uint16_t APID_MASK = 0x7FF;
    static const uint16_t PACKET_SEQUENCE_COUNT_MASK = 0x3FFF;

    uint8_t commandBuffer[PLOC::MAX_COMMAND_SIZE];

    /**
     * @brief   This object is incremented each time a packet is sent or received. By checking the
     *          packet sequence count of a received packet, no packets can be lost without noticing
     *          it. Only the least significant 14 bits represent the packet sequence count in a
     *          space packet. Thus the maximum value amounts to 16383 (0x3FFF).
     * @note    Normally this should never happen because the PLOC replies are always sent in a
     *          fixed order. However, the PLOC software checks this value and will return an ACK
     *          failure report in case the sequence count is not incremented with each transferred
     *          space packet.
     */
    uint16_t packetSequenceCount = 0x3FFF;

    /**
     * This variable is used to store the id of the next reply to receive. This is necessary
     * because the PLOC sends as reply to each command at least one acknowledgment and execution
     * report.
     */
    DeviceCommandId_t nextReplyId = PLOC::NONE;

    /**
     * @brief   This function fills the commandBuffer to initiate the write memory command.
     *
     * @param commandData   Pointer to action command data.
     * @param commanDataLen Size of command data in bytes.
     *
     * @return RETURN_OK if successful, else RETURN_FAILURE.
     */
    ReturnValue_t prepareTcMemWriteCommand(const uint8_t * commandData, size_t commandDataLen);

    /**
     * @brief   This function fills the commandBuffer to initiate the write reads command.
     *
     * @param commandData   Pointer to action command data.
     * @param commanDataLen Size of command data in bytes.
     *
     * @return RETURN_OK if successful, else RETURN_FAILURE.
     */
    ReturnValue_t prepareTcMemReadCommand(const uint8_t * commandData, size_t commandDataLen);

	/**
	 * @brief   This function checks the crc of the received PLOC reply.
	 *
	 * @param start Pointer to the first byte of the reply.
	 * @param foundLen  Pointer to the length of the whole packet.
	 *
	 * @return  RETURN_OK if CRC is ok, otherwise CRC_FAILURE.
	 */
	ReturnValue_t verifyPacket(const uint8_t* start, size_t foundLen);

	/**
	 * @brief   This function handles the acknowledgment report.
	 *
	 * @param data  Pointer to the data holding the acknowledgment report.
	 *
	 * @return  RETURN_OK if successful, otherwise an error code.
	 */
	ReturnValue_t handleAckReport(const uint8_t* data);

	/**
	 * @brief   This function handles the data of a execution report.
	 *
	 * @param data  Pointer to the received data packet.
	 *
	 * @return  RETURN_OK if successful, otherwise an error code.
	 */
	ReturnValue_t handleExecutionReport(const uint8_t* data);

	/**
	 * @brief   This function handles the memory read report.
	 *
	 * @param data  Pointer to the data buffer holding the memory read report.
	 *
	 * @return  RETURN_OK if successful, otherwise an error code.
	 */
	ReturnValue_t handleMemoryReadReport(const uint8_t* data);

	/**
     * @brief   Depending on the current active command, this function sets the reply id of the
     *          next reply after a successful acknowledgment report has been received. This is
     *          required by the function getNextReplyLength() to identify the length of the next
     *          reply to read.
	 */
	void setNextReplyId();

	/**
	 * @brief   This function handles action message replies in case the telemetry has been
	 *          requested by another object.
	 *
	 * @param data  Pointer to the telemetry data.
	 * @param dataSize  Size of telemetry in bytes.
	 * @param replyId   Id of the reply. This will be added to the ActionMessage.
	 */
	void handleDeviceTM(const uint8_t* data, size_t dataSize, DeviceCommandId_t replyId);

	/**
	 * @brief   In case an acknowledgment failure reply has been received this function disables
	 *          all previously enabled commands and resets the exepected replies variable of an
	 *          active command.
	 */
	void disableAllReplies();

	/**
	 * @brief   This function sends a failure report if the active action was commanded by an other
	 *          object.
	 *
	 * @param replyId   The id of the reply which signals a failure.
	 * @param status    A status byte which gives information about the failure type.
	 */
	void sendFailureReport(DeviceCommandId_t replyId, ReturnValue_t status);

	/**
	 * @brief   This function disables the execution report reply. Within this function also the
	 *          the variable expectedReplies of an active command will be set to 0.
	 */
	void disableExeReportReply();

	/**
	 * @brief   This function checks and increments the packet sequence count of a received space
	 *          packet.
	 *
	 * @param data  Pointer to a space packet.
	 *
	 * @return RETURN_OK if successful
	 *
	 * @details There should be never a case in which a wrong packet sequence count is received
	 *          because the communication scheme between PLOC and OBC always follows a strict
	 *          procedure. Thus this function mainly serves for debugging purposes to detected an
	 *          invalid handling of the packet sequence count.
	 */
	ReturnValue_t checkPacketSequenceCount(const uint8_t* data);
};

#endif /* MISSION_DEVICES_PLOCHANDLER_H_ */