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Diffstat (limited to 'src/bin/agent/ca_command_mgr.h')
| -rw-r--r-- | src/bin/agent/ca_command_mgr.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/bin/agent/ca_command_mgr.h b/src/bin/agent/ca_command_mgr.h new file mode 100644 index 0000000..c883f77 --- /dev/null +++ b/src/bin/agent/ca_command_mgr.h @@ -0,0 +1,118 @@ +// Copyright (C) 2017-2022 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 CTRL_AGENT_COMMAND_MGR_H +#define CTRL_AGENT_COMMAND_MGR_H + +#include <config/hooked_command_mgr.h> +#include <exceptions/exceptions.h> +#include <boost/noncopyable.hpp> +#include <boost/shared_ptr.hpp> + +namespace isc { +namespace agent { + +/// @brief Exception thrown when an error occurred during control command +/// forwarding. +class CommandForwardingError : public Exception { +public: + CommandForwardingError(const char* file, size_t line, const char* what) : + isc::Exception(file, line, what) { }; +}; + +/// @brief Command Manager for Control Agent. +/// +/// This is an implementation of the Command Manager within Control Agent. +/// In addition to the standard capabilities of the @ref HookedCommandMgr +/// it is also intended to forward commands to the respective Kea servers +/// when the command is not supported directly by the Control Agent. +/// +/// The @ref CtrlAgentCommandMgr is implemented as a singleton. The commands +/// are registered using @c CtrlAgentCommandMgr::instance().registerCommand(). +/// The @ref CtrlAgentResponseCreator uses the sole instance of the Command +/// Manager to handle incoming commands. +class CtrlAgentCommandMgr : public config::HookedCommandMgr, + public boost::noncopyable { +public: + + /// @brief Returns sole instance of the Command Manager. + static CtrlAgentCommandMgr& instance(); + + /// @brief Triggers command processing. + /// + /// This method overrides the @c BaseCommandMgr::processCommand to ensure + /// that the response is always wrapped in a list. The base implementation + /// returns a response map. Kea Control Agent forwards commands to multiple + /// daemons behind it and thus it must return a list of responses from + /// respective daemons. If an error occurs during command processing the + /// error response must also be wrapped in a list because caller expects + /// that CA always returns a list. + /// + /// This method is an entry point for dealing with a command. Internally + /// it calls @c CtrlAgentCommandMgr::handleCommand. + /// + /// @param cmd Pointer to the data element representing command in JSON + /// format. + /// @return Pointer to the response. + virtual isc::data::ConstElementPtr + processCommand(const isc::data::ConstElementPtr& cmd); + + /// @brief Handles the command having a given name and arguments. + /// + /// This method extends the base implementation with the ability to forward + /// commands to Kea servers. + /// + /// If the received command doesn't include 'service' parameter or this + /// parameter is blank, the command is first handled by the attached hooks + /// libraries, and if still unhandled, the Control Agent itself. + /// + /// If the non-blank 'service' parameter has been specified the hooks + /// are executed. If the hooks process the command the result is returned + /// to the controlling client. Otherwise, the command is forwarded to each + /// Kea server listed in the 'service' parameter. + /// + /// @param cmd_name Command name. + /// @param params Command arguments. + /// @param original_cmd Original command being processed. + /// + /// @return Pointer to the const data element representing a list of + /// responses to the command. If the command has been handled by the CA, + /// this list includes one response. + virtual isc::data::ConstElementPtr + handleCommand(const std::string& cmd_name, + const isc::data::ConstElementPtr& params, + const isc::data::ConstElementPtr& original_cmd); + +private: + + /// @brief Tries to forward received control command to a specified server. + /// + /// @param service Contains name of the service where the command should be + /// forwarded. + /// @param cmd_name Command name. + /// @param command Pointer to the object representing the forwarded command. + /// + /// @return Response to forwarded command. + /// @throw CommandForwardingError when an error occurred during forwarding. + isc::data::ConstElementPtr + forwardCommand(const std::string& service, const std::string& cmd_name, + const isc::data::ConstElementPtr& command); + + /// @brief Private constructor. + /// + /// The instance should be created using @ref CtrlAgentCommandMgr::instance, + /// thus the constructor is private. + CtrlAgentCommandMgr(); + + /// @brief Remote address of HTTP endpoint. + std::string remote_addr_; + +}; + +} // end of namespace isc::agent +} // end of namespace isc + +#endif |