Adding upstream version 2.4.1.upstream/2.4.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 503 insertions, 0 deletions

diff --git a/src/bin/dhcp4/ctrl_dhcp4_srv.h b/src/bin/dhcp4/ctrl_dhcp4_srv.h
new file mode 100644
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--- /dev/null
+++ b/src/bin/dhcp4/ctrl_dhcp4_srv.h
@@ -0,0 +1,503 @@
+// Copyright (C) 2012-2023 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_DHCPV4_SRV_H
+#define CTRL_DHCPV4_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 <dhcp4/dhcp4_srv.h>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief Controlled version of the DHCPv4 server
+///
+/// This is a class that is responsible for DHCPv4 server being controllable,
+/// by reading configuration file from disk.
+class ControlledDhcpv4Srv : public isc::dhcp::Dhcpv4Srv {
+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.
+    ControlledDhcpv4Srv(uint16_t server_port = DHCP4_SERVER_PORT,
+                        uint16_t client_port = 0);
+
+    /// @brief Destructor.
+    virtual ~ControlledDhcpv4Srv();
+
+    /// @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 DHCPv4 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 DHCPv4 server's configuration from the 'Dhcp4' 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 Dhcpv4Srv object
+    /// is destroyed. Currently it is a no-op.
+    void cleanup();
+
+    /// @brief Initiates shutdown procedure for the whole DHCPv4 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:
+    /// - shutdown
+    /// - libreload
+    /// - config-reload
+    /// - config-set
+    /// - config-get
+    /// - config-hash-get
+    /// - config-test
+    /// - dhcp-disable
+    /// - dhcp-enable
+    /// - version-get
+    /// - build-report
+    /// - leases-reclaim
+    /// - config-write
+    /// ...
+    ///
+    /// @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 config textual representation of the new configuration
+    ///
+    /// @return status of the config update
+    static isc::data::ConstElementPtr
+    processConfig(isc::data::ConstElementPtr config);
+
+    /// @brief Configuration checker
+    ///
+    /// This is a method for checking incoming configuration.
+    ///
+    /// @param config JSON representation of the new configuration
+    ///
+    /// @return status of the config check
+    static isc::data::ConstElementPtr
+    checkConfig(isc::data::ConstElementPtr config);
+
+    /// @brief Configuration checker for hook libraries
+    ///
+    /// This is a method for checking incoming configuration in the hooks
+    /// libraries. It calls dhcp4_srv_configured hook point for all hooks.
+    ///
+    /// @param config JSON representation of the new configuration
+    ///
+    /// @return status of the config check
+    static isc::data::ConstElementPtr
+    finishConfigHookLibraries(isc::data::ConstElementPtr config);
+
+    /// @brief Returns pointer to the sole instance of Dhcpv4Srv
+    ///
+    /// @return server instance (may return NULL, if called before server is spawned)
+    static ControlledDhcpv4Srv* 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::receive4() 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 'config-get' command
+    ///
+    /// This handler processes config-get 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 'config-hash-get' command
+    ///
+    /// This handler processes config-hash-get command, which retrieves
+    /// the hash of the current configuration and returns it in response.
+    ///
+    /// @param command (ignored)
+    /// @param args (ignored)
+    /// @return hash of current configuration wrapped in a response
+    isc::data::ConstElementPtr
+    commandConfigHashGetHandler(const std::string& command,
+                                isc::data::ConstElementPtr args);
+
+    /// @brief handler for processing 'config-write' command
+    ///
+    /// This handle processes config-write 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 Dhcp4 map that contains DHCPv4 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 Dhcp4 map that contains DHCPv4 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 IPv4 leases and reschedules timer.
+    ///
+    /// This is a wrapper method for @c AllocEngine::reclaimExpiredLeases4.
+    /// 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::deleteExpiredReclaimed4.
+    /// 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 CBControlDHCPv4::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 ControlledDhcpv4Srv* 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