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Diffstat (limited to 'src/lib/config/hooked_command_mgr.h')
| -rw-r--r-- | src/lib/config/hooked_command_mgr.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/src/lib/config/hooked_command_mgr.h b/src/lib/config/hooked_command_mgr.h new file mode 100644 index 0000000..fc5c258 --- /dev/null +++ b/src/lib/config/hooked_command_mgr.h @@ -0,0 +1,91 @@ +// Copyright (C) 2017 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 HOOKED_COMMAND_MGR_H +#define HOOKED_COMMAND_MGR_H + +#include <cc/data.h> +#include <config/base_command_mgr.h> + +namespace isc { +namespace config { + +/// @brief Command Manager which can delegate commands to a hook library. +/// +/// This class extends @ref BaseCommandMgr with the logic to delegate the +/// commands to a hook library if the hook library is installed and provides +/// command handlers for the control API. +/// +/// The command handlers are registered by a hook library by calling +/// @ref isc::hooks::LibraryHandle::registerCommandCallout. This call +/// creates a hook point for this command (if one doesn't exist) and then +/// registers the specified handler(s). When the @ref HookedCommandMgr +/// receives a command for processing it calls the +/// @ref isc::hooks::HooksManager::commandHandlersPresent to check if there +/// are handlers present for this command. If so, the @ref HookedCommandMgr +/// calls @ref isc::hooks::HooksManager::callCommandHandlers to process +/// the command in the hooks libraries. If command handlers are not installed +/// for this command, the @ref HookedCommandMgr will try to process the +/// command on its own. +/// +/// The @ref isc::hooks::CalloutHandle::CalloutNextStep flag setting by the +/// command handlers does NOT have any influence on the operation of the +/// @ref HookedCommandMgr, i.e. it will always skip processing command on +/// its own if the command handlers are present for the given command, even +/// if the handlers return an error code. +class HookedCommandMgr : public BaseCommandMgr { +public: + + /// @brief Constructor. + /// + /// Initializes callout handle used by the Command Manager. + HookedCommandMgr(); + +protected: + + /// @brief Handles the command within the hooks libraries. + /// + /// This method checks if the hooks libraries are installed which implement + /// command handlers for the specified command to be processed. If the + /// command handlers are present, this method calls them to create a response + /// and then passes the response back within the @c answer argument. + /// + /// Values of all arguments can be modified by the hook library. + /// + /// @param cmd_name Command name. + /// @param params Command arguments. + /// @param original_cmd Original command received. + /// @param [out] answer Command processing result returned by the hook. + /// + /// @return Boolean value indicating if any callouts have been executed. + bool + delegateCommandToHookLibrary(const std::string& cmd_name, + const isc::data::ConstElementPtr& params, + const isc::data::ConstElementPtr& original_cmd, + isc::data::ElementPtr& answer); + + /// @brief Handles the command having a given name and arguments. + /// + /// This method calls @ref HookedCommandMgr::delegateCommandToHookLibrary to + /// try to process the command with the hook libraries, if they are installed. + /// + /// @param cmd_name Command name. + /// @param params Command arguments. + /// @param original_cmd Original command received. + /// + /// @return Pointer to the const data element representing response + /// to a command. + virtual isc::data::ConstElementPtr + handleCommand(const std::string& cmd_name, + const isc::data::ConstElementPtr& params, + const isc::data::ConstElementPtr& original_cmd); + +}; + +} // end of namespace isc::config +} // end of namespace isc + +#endif |