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Diffstat (limited to 'src/hooks/dhcp/high_availability/ha_impl.h')
| -rw-r--r-- | src/hooks/dhcp/high_availability/ha_impl.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/src/hooks/dhcp/high_availability/ha_impl.h b/src/hooks/dhcp/high_availability/ha_impl.h new file mode 100644 index 0000000..3d66111 --- /dev/null +++ b/src/hooks/dhcp/high_availability/ha_impl.h @@ -0,0 +1,188 @@ +// Copyright (C) 2018-2021 Internet Systems Consortium, Inc. ("ISC") +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef HA_IMPL_H +#define HA_IMPL_H + +#include <ha_config.h> +#include <ha_service.h> +#include <asiolink/io_service.h> +#include <cc/data.h> +#include <dhcpsrv/network_state.h> +#include <hooks/hooks.h> +#include <boost/noncopyable.hpp> +#include <boost/shared_ptr.hpp> + + +namespace isc { +namespace ha { + +/// @brief High Availability hooks library implementation. +/// +/// This object provides an interface between the HA hook library callouts +/// and the HA state model implemented in the @c HAService. Callouts invoke +/// respective methods of the @c HAImpl to configure the service, generate +/// lease updates etc. The @c HAImpl retrieves and validates the arguments +/// provided within @c CalloutHandle object and then invokes appropriate +/// methods of the @c HAService class. +class HAImpl : public boost::noncopyable { +public: + + /// @brief Constructor. + HAImpl(); + + /// @brief Parses configuration. + /// + /// @param input_config Configuration specified for the hooks library. + /// @throw ConfigError when configuration fails. + void configure(const data::ConstElementPtr& input_config); + + /// @brief Creates high availability service using current configuration. + /// + /// The caller must ensure that the HA configuration is valid before + /// calling this function. + /// + /// @param io_service IO service object provided by the DHCP server. + /// @param network_state pointer to the object holding a state of the + /// DHCP service (enabled/disabled). + /// @param server_type DHCP server type for which the HA service should + /// be created. + void startService(const asiolink::IOServicePtr& io_service, + const dhcp::NetworkStatePtr& network_state, + const HAServerType& server_type); + + /// @brief Destructor. + ~HAImpl(); + +public: + + /// @brief Returns parsed configuration. + HAConfigPtr getConfig() const { + return (config_); + } + + /// @brief Implementation of the "buffer4_receive" callout. + /// + /// This callout uses HA service to check if the query should be processed + /// by this server or a partner. If the partner should process the query, + /// this callout sets the status to @c CalloutHandle::NEXT_STEP_DROP to + /// cause the server to drop the packet. Therefore it is important to note + /// that, if multiple hook libraries implementing @c buffer4_receive hook are + /// loaded, the order of loading the libraries may matter. If this library + /// sets the status to @c CalloutHandle::NEXT_STEP_DROP and the other library + /// overrides this status, the query will be processed by the server instead + /// of being dropped. This problem may be mitigated by loading the HA library + /// last, i.e. placing the library at the end of the "hooks-libraries" + /// list within a Kea configuration file. + /// + /// If the received query is to be processed by this server instance, the + /// @c CalloutHabndle::NEXT_STEP_SKIP status is set to prevent the server + /// from unpacking the query because the query is unpacked by the callout. + /// + /// @param callout_handle Callout handle provided to the callout. + void buffer4Receive(hooks::CalloutHandle& callout_handle); + + /// @brief Implementation of the "leases4_committed" callout. + /// + /// @param callout_handle Callout handle provided to the callout. + void leases4Committed(hooks::CalloutHandle& callout_handle); + + /// @brief Implementation of the "buffer6_receive" callout. + /// + /// This callout uses HA service to check if the query should be processed + /// by this server or a partner. If the partner should process the query, + /// this callout sets the status to @c CalloutHandle::NEXT_STEP_DROP to + /// cause the server to drop the packet. Therefore it is important to note + /// that, if multiple hook libraries implementing @c buffer6_receive hook are + /// loaded, the order of loading the libraries may matter. If this library + /// sets the status to @c CalloutHandle::NEXT_STEP_DROP and the other library + /// overrides this status, the query will be processed by the server instead + /// of being dropped. This problem may be mitigated by loading the HA library + /// last, i.e. placing the library at the end of the "hooks-libraries" + /// list within a Kea configuration file. + /// + /// If the received query is to be processed by this server instance, the + /// @c CalloutHabndle::NEXT_STEP_SKIP status is set to prevent the server + /// from unpacking the query because the query is unpacked by the callout. + /// + /// @param callout_handle Callout handle provided to the callout. + void buffer6Receive(hooks::CalloutHandle& callout_handle); + + /// @brief Implementation of the "leases6_committed" callout. + /// + /// @param callout_handle Callout handle provided to the callout. + void leases6Committed(hooks::CalloutHandle& callout_handle); + + /// @brief Implementation of the "command_processed" callout. + /// + /// It adds the HA servers information to "status-get" command responses by + /// calling @c HAService::commandProcessed. + /// + /// @param callout_handle Callout handle provided to the callout. + void commandProcessed(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handle for the heartbeat command. + /// + /// @param callout_handle Callout handle provided to the callout. + void heartbeatHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-sync command. + /// + /// @param callout_handle Callout handle provided to the callout. + void synchronizeHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-scopes command. + /// + /// @param callout_handle Callout handle provided to the callout. + void scopesHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-continue command. + /// + /// @param callout_handle Callout handle provided to the callout. + void continueHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-maintenance-notify command. + /// + /// @param callout_handle Callout handle provided to the callout. + void maintenanceNotifyHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-maintenance-start command. + /// + /// @param callout_handle Callout handle provided to the callout. + void maintenanceStartHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-maintenance-cancel command. + /// + /// @param callout_handle Callout handle provided to the callout. + void maintenanceCancelHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-reset command. + /// + /// @param callout_handle Callout handle provided to the callout. + void haResetHandler(hooks::CalloutHandle& callout_handle); + + /// @brief Implements handler for the ha-sync-complete-notify command. + /// + /// @param callout_handle Callout handle provided to the callout. + void syncCompleteNotifyHandler(hooks::CalloutHandle& callout_handle); + +protected: + + /// @brief Holds parsed configuration. + HAConfigPtr config_; + + /// @brief Pointer to the high availability service (state machine). + HAServicePtr service_; + +}; + +/// @brief Pointer to the High Availability hooks library implementation. +typedef boost::shared_ptr<HAImpl> HAImplPtr; + +} // end of namespace isc::ha +} // end of namespace isc + +#endif |