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Diffstat (limited to 'src/bin/dhcp6/ctrl_dhcp6_srv.h')
| -rw-r--r-- | src/bin/dhcp6/ctrl_dhcp6_srv.h | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/src/bin/dhcp6/ctrl_dhcp6_srv.h b/src/bin/dhcp6/ctrl_dhcp6_srv.h new file mode 100644 index 0000000..adff127 --- /dev/null +++ b/src/bin/dhcp6/ctrl_dhcp6_srv.h @@ -0,0 +1,473 @@ +// Copyright (C) 2012-2022 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_DHCPV6_SRV_H +#define CTRL_DHCPV6_SRV_H + +#include <asiolink/asio_wrapper.h> +#include <asiolink/asiolink.h> +#include <cc/data.h> +#include <cc/command_interpreter.h> +#include <util/reconnect_ctl.h> +#include <dhcpsrv/timer_mgr.h> +#include <dhcp6/dhcp6_srv.h> + +namespace isc { +namespace dhcp { + +/// @brief Controlled version of the DHCPv6 server +/// +/// This is a class that is responsible for DHCPv6 server being controllable, +/// by reading configuration file from disk. +class ControlledDhcpv6Srv : public isc::dhcp::Dhcpv6Srv { +public: + + /// @brief Constructor + /// + /// @param server_port UDP port to be opened for DHCP traffic + /// @param client_port UDP port where all responses are sent to. + ControlledDhcpv6Srv(uint16_t server_port = DHCP6_SERVER_PORT, + uint16_t client_port = 0); + + /// @brief Destructor. + virtual ~ControlledDhcpv6Srv(); + + /// @brief Initializes the server. + /// + /// It reads the JSON file from disk or may perform any other setup + /// operation. In particular, it also install signal handlers. + /// + /// This method may throw if initialization fails. + void init(const std::string& config_file); + + /// @brief Configure DHCPv6 server using the configuration file specified. + /// + /// This function is used to both configure the DHCP server on its startup + /// and dynamically reconfigure the server when SIGHUP signal is received. + /// + /// It fetches DHCPv6 server's configuration from the 'Dhcp6' section of + /// the JSON configuration file. + /// + /// This utility method is called whenever we know a filename of the config + /// and need to load it. It calls config-set command once the content of + /// the file has been loaded and verified to be a sane JSON configuration. + /// config-set handler will process the config file (apply it as current + /// configuration). + /// + /// @param file_name name of the file to be loaded + /// @return status of the file loading and outcome of config-set + isc::data::ConstElementPtr + loadConfigFile(const std::string& file_name); + + /// @brief Performs cleanup, immediately before termination + /// + /// This method performs final clean up, just before the Dhcpv6Srv object + /// is destroyed. Currently it is a no-op. + void cleanup(); + + /// @brief Initiates shutdown procedure for the whole DHCPv6 server. + /// @param exit_value integer value to the process should exit with. + virtual void shutdownServer(int exit_value); + + /// @brief Command processor + /// + /// This method is uniform for all config backends. It processes received + /// command (as a string + JSON arguments). Internally, it's just a + /// wrapper that calls process*Command() methods and catches exceptions + /// in them. + /// + /// Currently supported commands are: + /// - config-reload + /// - config-test + /// - shutdown + /// - libreload + /// - leases-reclaim + /// ... + /// + /// @note It never throws. + /// + /// @param command Text representation of the command (e.g. "shutdown") + /// @param args Optional parameters + /// + /// @return status of the command + static isc::data::ConstElementPtr + processCommand(const std::string& command, isc::data::ConstElementPtr args); + + /// @brief Configuration processor + /// + /// This is a method for handling incoming configuration updates. + /// This method should be called by all configuration backends when the + /// server is starting up or when configuration has changed. + /// + /// As pointer to this method is used a callback in ASIO used in + /// ModuleCCSession, it has to be static. + /// + /// @param new_config textual representation of the new configuration + /// + /// @return status of the config update + static isc::data::ConstElementPtr + processConfig(isc::data::ConstElementPtr new_config); + + /// @brief Configuration checker + /// + /// This is a method for checking incoming configuration. + /// + /// @param new_config JSON representation of the new configuration + /// + /// @return status of the config check + isc::data::ConstElementPtr + checkConfig(isc::data::ConstElementPtr new_config); + + /// @brief Returns pointer to the sole instance of Dhcpv6Srv + /// + /// @return server instance (may return NULL, if called before server is spawned) + static ControlledDhcpv6Srv* getInstance() { + return (server_); + } + +private: + + /// @brief Callback that will be called from iface_mgr when data + /// is received over control socket. + /// + /// This static callback method is called from IfaceMgr::receive6() method, + /// when there is a new command or configuration sent over control socket + /// (that was sent from some yet unspecified sender). + static void sessionReader(void); + + /// @brief Handler for processing 'shutdown' command + /// + /// This handler processes shutdown command, which initializes shutdown + /// procedure. + /// @param command (parameter ignored) + /// @param args (parameter ignored) + /// + /// @return status of the command + isc::data::ConstElementPtr + commandShutdownHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief Handler for processing 'libreload' command + /// + /// This handler processes libreload command, which unloads all hook + /// libraries and reloads them. + /// + /// @param command (parameter ignored) + /// @param args (parameter ignored) + /// + /// @return status of the command + isc::data::ConstElementPtr + commandLibReloadHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief Handler for processing 'config-reload' command + /// + /// This handler processes config-reload command, which processes + /// configuration specified in args parameter. + /// + /// @param command (parameter ignored) + /// @param args configuration to be processed + /// + /// @return status of the command + isc::data::ConstElementPtr + commandConfigReloadHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'get-config' command + /// + /// This handler processes get-config command, which retrieves + /// the current configuration and returns it in response. + /// + /// @param command (ignored) + /// @param args (ignored) + /// @return current configuration wrapped in a response + isc::data::ConstElementPtr + commandConfigGetHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'write-config' command + /// + /// This handle processes write-config command, which writes the + /// current configuration to disk. This command takes one optional + /// parameter called filename. If specified, the current configuration + /// will be written to that file. If not specified, the file used during + /// Kea start-up will be used. To avoid any exploits, the path is + /// always relative and .. is not allowed in the filename. This is + /// a security measure against exploiting file writes remotely. + /// + /// @param command (ignored) + /// @param args may contain optional string argument filename + /// @return status of the configuration file write + isc::data::ConstElementPtr + commandConfigWriteHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'config-set' command + /// + /// This handler processes config-set command, which processes + /// configuration specified in args parameter. + /// @param command (parameter ignored) + /// @param args configuration to be processed. Expected format: + /// map containing Dhcp6 map that contains DHCPv6 server configuration. + /// + /// @return status of the command + isc::data::ConstElementPtr + commandConfigSetHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'config-test' command + /// + /// This handler processes config-test command, which checks + /// configuration specified in args parameter. + /// @param command (parameter ignored) + /// @param args configuration to be checked. Expected format: + /// map containing Dhcp6 map that contains DHCPv6 server configuration. + /// + /// @return status of the command + isc::data::ConstElementPtr + commandConfigTestHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief A handler for processing 'dhcp-disable' command. + /// + /// @param command command name (ignored). + /// @param args arguments for the command. It must be a map and + /// it may include optional 'max-period' parameter. + /// + /// @return result of the command. + isc::data::ConstElementPtr + commandDhcpDisableHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief A handler for processing 'dhcp-enable' command. + /// + /// @param command command name (ignored) + /// @param args arguments for the command (ignored). + /// + /// @return result of the command. + isc::data::ConstElementPtr + commandDhcpEnableHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @Brief handler for processing 'version-get' command + /// + /// This handler processes version-get command, which returns + /// over the control channel the -v and -V command line arguments. + /// @param command (parameter ignored) + /// @param args (parameter ignored) + /// + /// @return status of the command with the version in text and + /// the extended version in arguments. + isc::data::ConstElementPtr + commandVersionGetHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'build-report' command + /// + /// This handler processes build-report command, which returns + /// over the control channel the -W command line argument. + /// @param command (parameter ignored) + /// @param args (parameter ignored) + /// + /// @return status of the command with the config report + isc::data::ConstElementPtr + commandBuildReportHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief Handler for processing 'leases-reclaim' command + /// + /// This handler processes leases-reclaim command, which triggers + /// the leases reclamation immediately. + /// No limit for processing time or number of processed leases applies. + /// + /// @param command (parameter ignored) + /// @param args arguments map { "remove": <bool> } + /// if true a lease is removed when it is reclaimed, + /// if false its state is changed to "expired-reclaimed". + /// + /// @return status of the command (should be success unless args + /// was not a Bool Element). + isc::data::ConstElementPtr + commandLeasesReclaimHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for server-tag-get command + /// + /// This method handles the server-tag-get command, which retrieves + /// the current server tag and returns it in response. + /// + /// @param command (ignored) + /// @param args (ignored) + /// @return current configuration wrapped in a response + isc::data::ConstElementPtr + commandServerTagGetHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for config-backend-pull command + /// + /// This method handles the config-backend-pull command, which updates + /// the server configuration from the Config Backends immediately. + /// + /// @param command (parameter ignored) + /// @param args (ignored) + /// + /// @return status of the command/ + isc::data::ConstElementPtr + commandConfigBackendPullHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'status-get' command + /// + /// This handler processes status-get command, which retrieves + /// the server process information i.e. the pid and returns it in response. + /// + /// @param command (ignored) + /// @param args (ignored) + /// @return process information wrapped in a response + isc::data::ConstElementPtr + commandStatusGetHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'statistic-sample-count-set-all' command + /// + /// This handler processes statistic-sample-count-set-all command, + /// which sets max_sample_count_ limit of all statistics and the default. + /// @ref isc::stats::StatsMgr::statisticSetMaxSampleCountAllHandler + /// + /// @param command (ignored) + /// @param args structure containing a map that contains "max-samples" + /// @return process information wrapped in a response + isc::data::ConstElementPtr + commandStatisticSetMaxSampleCountAllHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief handler for processing 'statistic-sample-age-set-all' command + /// + /// This handler processes statistic-sample-age-set-all command, + /// which sets max_sample_age_ limit of all statistics and the default. + /// @ref isc::stats::StatsMgr::statisticSetMaxSampleAgeAllHandler + /// + /// @param command (ignored) + /// @param args structure containing a map that contains "duration" + /// @return process information wrapped in a response + isc::data::ConstElementPtr + commandStatisticSetMaxSampleAgeAllHandler(const std::string& command, + isc::data::ConstElementPtr args); + + /// @brief Reclaims expired IPv6 leases and reschedules timer. + /// + /// This is a wrapper method for @c AllocEngine::reclaimExpiredLeases6. + /// It reschedules the timer for leases reclamation upon completion of + /// this method. + /// + /// @param max_leases Maximum number of leases to be reclaimed. + /// @param timeout Maximum amount of time that the reclamation routine + /// may be processing expired leases, expressed in milliseconds. + /// @param remove_lease A boolean value indicating if the lease should + /// be removed when it is reclaimed (if true) or it should be left in the + /// database in the "expired-reclaimed" state (if false). + /// @param max_unwarned_cycles A number of consecutive processing cycles + /// of expired leases, after which the system issues a warning if there + /// are still expired leases in the database. If this value is 0, the + /// warning is never issued. + void reclaimExpiredLeases(const size_t max_leases, const uint16_t timeout, + const bool remove_lease, + const uint16_t max_unwarned_cycles); + + /// @brief Deletes reclaimed leases and reschedules the timer. + /// + /// This is a wrapper method for @c AllocEngine::deleteExpiredReclaimed6. + /// It reschedules the timer for leases reclamation upon completion of + /// this method. + /// + /// @param secs Minimum number of seconds after which a lease can be + /// deleted. + void deleteExpiredReclaimedLeases(const uint32_t secs); + + /// @brief Callback DB backends should be invoked upon loss of the + /// connectivity. + /// + /// This function is invoked by DB backends when they detect a loss of + /// connectivity. The parameter, db_reconnect_ctl, conveys the configured + /// maximum number of reconnect retries as well as the interval to wait + /// between retry attempts. + /// + /// If either value is zero, reconnect is presumed to be disabled and + /// the function will schedule a shutdown and return false. This instructs + /// the DB backend layer (the caller) to treat the connectivity loss as + /// fatal. It stops the DHCP service until the connection is recovered. + /// + /// @param db_reconnect_ctl pointer to the ReconnectCtl containing the + /// configured reconnect parameters + /// + /// @return false if reconnect is not configured, true otherwise + bool dbLostCallback(util::ReconnectCtlPtr db_reconnect_ctl); + + /// @brief Callback DB backends should be invoked upon restoration of + /// connectivity. + /// + /// This function is invoked by DB backends when they recover the + /// connectivity. It starts the DHCP service after the connection is + /// recovered. + /// + /// @param db_reconnect_ctl pointer to the ReconnectCtl containing the + /// configured reconnect parameters + /// + /// @return false if reconnect is not configured, true otherwise + bool dbRecoveredCallback(util::ReconnectCtlPtr db_reconnect_ctl); + + /// @brief Callback DB backends should be invoked upon failing to restore + /// connectivity. + /// + /// This function is invoked by DB backends when they fail to recover the + /// connectivity. It stops the server. + /// + /// @param db_reconnect_ctl pointer to the ReconnectCtl containing the + /// configured reconnect parameters + /// + /// @return false if reconnect is not configured, true otherwise + bool dbFailedCallback(util::ReconnectCtlPtr db_reconnect_ctl); + + /// @brief This callback should be invoked upon failing to bind sockets. + /// + /// This function is invoked during the configuration of the interfaces + /// when they fail to bind the service sockets. It may stop the server. + /// + /// @param reconnect_ctl pointer to the ReconnectCtl containing the + /// configured reconnect parameters + void openSocketsFailedCallback(util::ReconnectCtlPtr reconnect_ctl); + + /// @brief Callback invoked periodically to fetch configuration updates + /// from the Config Backends. + /// + /// This method calls @c CBControlDHCPv6::databaseConfigFetch and then + /// reschedules the timer. + /// + /// @param srv_cfg Server configuration holding the database credentials + /// and server tag. + /// @param failure_count pointer to failure counter which causes this + /// callback to stop scheduling the timer after 10 consecutive failures + /// to fetch the updates. + void cbFetchUpdates(const SrvConfigPtr& srv_cfg, + boost::shared_ptr<unsigned> failure_count); + + /// @brief Static pointer to the sole instance of the DHCP server. + /// + /// This is required for config and command handlers to gain access to + /// the server. Some of them need to be static methods. + static ControlledDhcpv6Srv* server_; + + /// @brief Instance of the @c TimerMgr. + /// + /// Shared pointer to the instance of timer @c TimerMgr is held here to + /// make sure that the @c TimerMgr outlives instance of this class. + TimerMgrPtr timer_mgr_; +}; + +} // namespace dhcp +} // namespace isc + +#endif |