requester/mctp_endpoint_discovery.hpp

#pragma once

#include "common/types.hpp"
#include "common/utils.hpp"

#include <libpldm/pldm.h>

#include <sdbusplus/bus/match.hpp>

#include <filesystem>
#include <initializer_list>
#include <vector>

namespace pldm
{

const std::string emptyUUID = "00000000-0000-0000-0000-000000000000";
constexpr const char* MCTPService = "xyz.openbmc_project.MCTP";
constexpr const char* MCTPInterface = "xyz.openbmc_project.MCTP.Endpoint";
constexpr const char* EndpointUUID = "xyz.openbmc_project.Common.UUID";
constexpr const char* MCTPPath = "/xyz/openbmc_project/mctp";

/** @class MctpDiscoveryHandlerIntf
 *
 * This abstract class defines the APIs for MctpDiscovery class has common
 * interface to execute function from different Manager Classes
 */
class MctpDiscoveryHandlerIntf
{
  public:
    virtual void handleMctpEndpoints(const MctpInfos& mctpInfos) = 0;
    virtual void handleRemovedMctpEndpoints(const MctpInfos& mctpInfos) = 0;
    virtual ~MctpDiscoveryHandlerIntf() {}
};

class MctpDiscovery
{
  public:
    MctpDiscovery() = delete;
    MctpDiscovery(const MctpDiscovery&) = delete;
    MctpDiscovery(MctpDiscovery&&) = delete;
    MctpDiscovery& operator=(const MctpDiscovery&) = delete;
    MctpDiscovery& operator=(MctpDiscovery&&) = delete;
    ~MctpDiscovery() = default;

    /** @brief Constructs the MCTP Discovery object to handle discovery of
     *         MCTP enabled devices
     *
     *  @param[in] bus - reference to systemd bus
     *  @param[in] list - initializer list to the MctpDiscoveryHandlerIntf
     */
    explicit MctpDiscovery(
        sdbusplus::bus_t& bus,
        std::initializer_list<MctpDiscoveryHandlerIntf*> list);

    /** @brief reference to the systemd bus */
    sdbusplus::bus_t& bus;

    /** @brief Used to watch for new MCTP endpoints */
    sdbusplus::bus::match_t mctpEndpointAddedSignal;

    /** @brief Used to watch for the removed MCTP endpoints */
    sdbusplus::bus::match_t mctpEndpointRemovedSignal;

    /** @brief List of handlers need to notify when new MCTP
     * Endpoint is Added/Removed */
    std::vector<MctpDiscoveryHandlerIntf*> handlers;

    /** @brief The existing MCTP endpoints */
    MctpInfos existingMctpInfos;

    /** @brief Callback function when MCTP endpoints addedInterface
     * D-Bus signal raised.
     *
     *  @param[in] msg - Data associated with subscribed signal
     */
    void discoverEndpoints(sdbusplus::message_t& msg);

    /** @brief Callback function when MCTP endpoint removedInterface
     * D-Bus signal raised.
     *
     *  @param[in] msg - Data associated with subscribed signal
     */
    void removeEndpoints(sdbusplus::message_t& msg);

    /** @brief Helper function to invoke registered handlers for
     *  the added MCTP endpoints
     *
     *  @param[in] mctpInfos - information of discovered MCTP endpoints
     */
    void handleMctpEndpoints(const MctpInfos& mctpInfos);

    /** @brief Helper function to invoke registered handlers for
     *  the removed MCTP endpoints
     *
     *  @param[in] mctpInfos - information of removed MCTP endpoints
     */
    void handleRemovedMctpEndpoints(const MctpInfos& mctpInfos);

    /** @brief Get list of MctpInfos in MCTP control interface.
     *
     *  @param[in] mctpInfos - information of discovered MCTP endpoints
     */
    void getMctpInfos(MctpInfos& mctpInfos);

    /** @brief Get list of new MctpInfos in addedInterace D-Bus signal message.
     *
     *  @param[in] msg - addedInterace D-Bus signal message
     *  @param[in] mctpInfos - information of added MCTP endpoints
     */
    void getAddedMctpInfos(sdbusplus::message_t& msg, MctpInfos& mctpInfos);

    /** @brief Add new MctpInfos to existingMctpInfos.
     *
     *  @param[in] mctpInfos - information of new MCTP endpoints
     */
    void addToExistingMctpInfos(const MctpInfos& mctpInfos);

    /** @brief Erase the removed MCTP endpoint from existingMctpInfos.
     *
     *  @param[in] mctpInfos - the remaining MCTP endpoints
     *  @param[out] removedInfos - the removed MCTP endpoints
     */
    void removeFromExistingMctpInfos(MctpInfos& mctpInfos,
                                     MctpInfos& removedInfos);

  private:
    /** @brief Get MCTP Endpoint D-Bus Properties in the
     *         `xyz.openbmc_project.MCTP.Endpoint` D-Bus interface
     *
     *  @param[in] service - the MCTP service name
     *  @param[in] path - the MCTP endpoints object path
     *
     *  @return tuple of Network Index, Endpoint ID and MCTP message types
     */
    MctpEndpointProps getMctpEndpointProps(const std::string& service,
                                           const std::string& path);

    /** @brief Get Endpoint UUID from `UUID` D-Bus property in the
     *         `xyz.openbmc_project.Common.UUID` D-Bus interface.
     *
     *  @param[in] service - the MCTP service name
     *  @param[in] path - the MCTP endpoints object path
     *
     *  @return Endpoint UUID
     */
    UUID getEndpointUUIDProp(const std::string& service,
                             const std::string& path);

    static constexpr uint8_t mctpTypePLDM = 1;
};

} // namespace pldm