Adding upstream version 2.2.0.upstream/2.2.0upstream

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

1 files changed, 691 insertions, 0 deletions

diff --git a/src/lib/dhcpsrv/config_backend_dhcp4.h b/src/lib/dhcpsrv/config_backend_dhcp4.h
new file mode 100644
index 0000000..a235a4b
--- /dev/null
+++ b/src/lib/dhcpsrv/config_backend_dhcp4.h
@@ -0,0 +1,691 @@
+// 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 CONFIG_BACKEND_DHCP4_H
+#define CONFIG_BACKEND_DHCP4_H
+
+#include <cc/stamped_value.h>
+#include <config_backend/base_config_backend.h>
+#include <database/audit_entry.h>
+#include <database/server.h>
+#include <database/server_collection.h>
+#include <database/server_selector.h>
+#include <dhcp/option.h>
+#include <dhcp/option_definition.h>
+#include <dhcpsrv/cfg_option.h>
+#include <dhcpsrv/client_class_def.h>
+#include <dhcpsrv/shared_network.h>
+#include <dhcpsrv/subnet.h>
+#include <boost/shared_ptr.hpp>
+#include <boost/date_time/posix_time/ptime.hpp>
+#include <string>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief Interface implemented by DHCPv4 configuration backends.
+///
+/// All POSIX times specified in the methods belonging to this
+/// class must be local times.
+///
+/// Below, we describe the general rules of using the server selectors
+/// when creating, updating, fetching and deleting the configuration
+/// elements from the backends. The detailed information can be found
+/// in the descriptions of the individual methods. The backend
+/// implementations must not be in conflict with the rules described
+/// here but may sometimes lack some functionality and not support
+/// some of the server selectors for some API calls. In such cases
+/// the backend's documentation should be clear about these cases
+/// and document the exceptions thrown when unsupported selector is
+/// used for a given method.
+///
+/// The @c ServerSelector class defines 5 types of selectors:
+/// - ANY: server tag/id is not a part of the database query, i.e. the
+///   object in the database is identified by some unique property,
+///   e.g. subnet identifier, shared network name etc.
+///
+/// - UNASSIGNED: query pertains to the objects in the database which
+///   are associated with no particular server (including the logical
+///   server "all"). Objects associated with any server are never
+///   selected.
+///
+/// - ALL: query pertains only to the objects in the database which are
+///   associated with the logical server "all". Those objects are shared
+///   between all servers using the database. This server selector never
+///   returns objects explicitly associated with the particular servers
+///   defined by the user.
+///
+/// - ONE: query pertains to the objects used by one particular server.
+///   The server uses both the objects explicitly associated with it and
+///   and the objects associated with the logical server "all". Therefore
+///   the result returned for this server selector combines configuration
+///   elements associated with this server and with "all" servers. In case
+///   if there are two instances of the configuration information, one
+///   associated with "all" servers and one associated with the server,
+///   the information associated with the server takes precedence.
+///   When using this selector to delete objects from the database, the
+///   deletion pertains only to the objects associated with the given
+///   server tag. It doesn't delete the objects associated with "all"
+///   servers.
+///
+/// - MULTIPLE: query pertains to the objects used by multiple servers
+///   listed in the selector. It allows for querying for a list of
+///   objects associated with multiple servers and/or logical server
+///   "all".
+///
+/// There are limitations imposed on the API calls what server selectors
+/// are allowed for them. Configuration Backend implementations must not
+/// be in conflict with those limitations. In particular, the implementation
+/// must not permit for server selectors which are not allowed here.
+/// However, the backend implementation may be more restrictive and not
+/// allow some of the server selectors for some API calls. This should,
+/// however, be properly documented.
+class ConfigBackendDHCPv4 : public cb::BaseConfigBackend {
+public:
+
+    /// @brief Virtual destructor.
+    virtual ~ConfigBackendDHCPv4() { }
+
+    /// @brief Retrieves a single subnet by subnet_prefix.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_prefix Prefix of the subnet to be retrieved.
+    /// @return Pointer to the retrieved subnet or NULL if not found.
+    virtual Subnet4Ptr
+    getSubnet4(const db::ServerSelector& server_selector,
+               const std::string& subnet_prefix) const = 0;
+
+    /// @brief Retrieves a single subnet by subnet identifier.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_id Identifier of a subnet to be retrieved.
+    /// @return Pointer to the retrieved subnet or NULL if not found.
+    virtual Subnet4Ptr
+    getSubnet4(const db::ServerSelector& server_selector, const SubnetID& subnet_id) const = 0;
+
+    /// @brief Retrieves all subnets.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Collection of subnets or empty collection if no subnet found.
+    virtual Subnet4Collection
+    getAllSubnets4(const db::ServerSelector& server_selector) const = 0;
+
+    /// @brief Retrieves all subnets belonging to a specified shared network.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param shared_network_name Name of the shared network for which the
+    /// retrieved subnets should belongs to.
+    /// @return Collection of subnets or empty collection if no subnet found.
+    virtual Subnet4Collection
+    getSharedNetworkSubnets4(const db::ServerSelector& server_selector,
+                             const std::string& shared_network_name) const = 0;
+
+    /// @brief Retrieves subnets modified after specified time.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @param modification_time Lower bound subnet modification time.
+    /// @return Collection of subnets or empty collection if no subnet found.
+    virtual Subnet4Collection
+    getModifiedSubnets4(const db::ServerSelector& server_selector,
+                        const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves shared network by name.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param name Name of the shared network to be retrieved.
+    /// @return Pointer to the shared network or NULL if not found.
+    virtual SharedNetwork4Ptr
+    getSharedNetwork4(const db::ServerSelector& server_selector,
+                      const std::string& name) const = 0;
+
+    /// @brief Retrieves all shared networks.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Collection of shared network or empty collection if
+    /// no shared network found.
+    virtual SharedNetwork4Collection
+    getAllSharedNetworks4(const db::ServerSelector& server_selector) const = 0;
+
+    /// @brief Retrieves shared networks modified after specified time.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @param modification_time Lower bound shared network modification time.
+    /// @return Collection of shared network or empty collection if
+    /// no shared network found.
+    virtual SharedNetwork4Collection
+    getModifiedSharedNetworks4(const db::ServerSelector& server_selector,
+                               const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves single option definition by code and space.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param code Code of the option to be retrieved.
+    /// @param space Option space of the option to be retrieved.
+    /// @return Pointer to the option definition or NULL if not found.
+    virtual OptionDefinitionPtr
+    getOptionDef4(const db::ServerSelector& server_selector, const uint16_t code,
+                  const std::string& space) const = 0;
+
+    /// @brief Retrieves all option definitions.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Collection of option definitions or empty collection if
+    /// no option definition found.
+    virtual OptionDefContainer
+    getAllOptionDefs4(const db::ServerSelector& server_selector) const = 0;
+
+    /// @brief Retrieves option definitions modified after specified time.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param server_selector Server selector.
+    /// @param modification_time Lower bound option definition modification
+    /// time.
+    /// @return Collection of option definitions or empty collection if
+    /// no option definition found.
+    virtual OptionDefContainer
+    getModifiedOptionDefs4(const db::ServerSelector& server_selector,
+                           const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves single option by code and space.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param code Option code.
+    /// @param space Option space.
+    /// @return Pointer to the retrieved option descriptor or null if
+    /// no option was found.
+    virtual OptionDescriptorPtr
+    getOption4(const db::ServerSelector& server_selector, const uint16_t code,
+               const std::string& space) const = 0;
+
+    /// @brief Retrieves all global options.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Collection of global options or empty collection if no
+    /// option found.
+    virtual OptionContainer
+    getAllOptions4(const db::ServerSelector& server_selector) const = 0;
+
+    /// @brief Retrieves options modified after specified time.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param selector Server selector.
+    /// @param modification_time Lower bound option modification time.
+    /// @return Collection of global options or empty collection if no
+    /// option found.
+    virtual OptionContainer
+    getModifiedOptions4(const db::ServerSelector& selector,
+                        const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves global parameter value.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param selector Server selector.
+    /// @param name Name of the global parameter to be retrieved.
+    /// @return Value of the global parameter or null if parameter doesn't
+    /// exist.
+    virtual data::StampedValuePtr
+    getGlobalParameter4(const db::ServerSelector& selector,
+                        const std::string& name) const = 0;
+
+    /// @brief Retrieves all global parameters.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param selector Server selector.
+    /// @return Collection of global parameters.
+    virtual data::StampedValueCollection
+    getAllGlobalParameters4(const db::ServerSelector& selector) const = 0;
+
+    /// @brief Retrieves global parameters modified after specified time.
+    ///
+    /// Allowed server selectors: ALL, ONE, MULTIPLE.
+    /// Not allowed server selectors: ANY, UNASSIGNED.
+    ///
+    /// @param selector Server selector.
+    /// @param modification_time Modification time.
+    /// @return Collection of modified global parameters.
+    virtual data::StampedValueCollection
+    getModifiedGlobalParameters4(const db::ServerSelector& selector,
+                                 const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves a client class by name.
+    ///
+    /// @param selector Server selector.
+    /// @param name Client class name.
+    /// @return Pointer to the retrieved client class.
+    virtual ClientClassDefPtr
+    getClientClass4(const db::ServerSelector& selector, const std::string& name) const = 0;
+
+    /// @brief Retrieves all client classes.
+    ///
+    /// @param selector Server selector.
+    /// @return Collection of client classes.
+    virtual ClientClassDictionary
+    getAllClientClasses4(const db::ServerSelector& selector) const = 0;
+
+    /// @brief Retrieves client classes modified after specified time.
+    ///
+    /// @param selector Server selector.
+    /// @param modification_time Modification time.
+    /// @return Collection of client classes.
+    virtual ClientClassDictionary
+    getModifiedClientClasses4(const db::ServerSelector& selector,
+                              const boost::posix_time::ptime& modification_time) const = 0;
+
+    /// @brief Retrieves the most recent audit entries.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param modification_time Timestamp being a lower limit for the returned
+    /// result set, i.e. entries later than specified time are returned.
+    /// @param modification_id Identifier being a lower limit for the returned
+    /// result set, used when two (or more) entries have the same
+    /// modification_time.
+    /// @return Collection of audit entries.
+    virtual db::AuditEntryCollection
+    getRecentAuditEntries(const db::ServerSelector& server_selector,
+                          const boost::posix_time::ptime& modification_time,
+                          const uint64_t& modification_id) const = 0;
+
+    /// @brief Retrieves all servers.
+    ///
+    /// This method returns the list of servers excluding the logical server
+    /// 'all'.
+    ///
+    /// @return Collection of servers from the backend.
+    virtual db::ServerCollection
+    getAllServers4() const = 0;
+
+    /// @brief Retrieves a server.
+    ///
+    /// @param server_tag Tag of the server to be retrieved.
+    /// @return Pointer to the server instance or null pointer if no server
+    /// with the particular tag was found.
+    virtual db::ServerPtr
+    getServer4(const data::ServerTag& server_tag) const = 0;
+
+    /// @brief Creates or updates a subnet.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet Subnet to be added or updated.
+    virtual void
+    createUpdateSubnet4(const db::ServerSelector& server_selector,
+                        const Subnet4Ptr& subnet) = 0;
+
+    /// @brief Creates or updates a shared network.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    /// Not allowed server selector: ANY.
+    ///
+    /// @param server_selector Server selector.
+    /// @param shared_network Shared network to be added or updated.
+    virtual void
+    createUpdateSharedNetwork4(const db::ServerSelector& server_selector,
+                               const SharedNetwork4Ptr& shared_network) = 0;
+
+    /// @brief Creates or updates an option definition.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param option_def Option definition to be added or updated.
+    virtual void
+    createUpdateOptionDef4(const db::ServerSelector& server_selector,
+                           const OptionDefinitionPtr& option_def) = 0;
+
+    /// @brief Creates or updates global option.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param option Option to be added or updated.
+    virtual void
+    createUpdateOption4(const db::ServerSelector& server_selector,
+                        const OptionDescriptorPtr& option) = 0;
+
+    /// @brief Creates or updates shared network level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param selector Server selector.
+    /// @param shared_network_name Name of a shared network to which option
+    /// belongs.
+    /// @param option Option to be added or updated.
+    virtual void
+    createUpdateOption4(const db::ServerSelector& selector,
+                        const std::string& shared_network_name,
+                        const OptionDescriptorPtr& option) = 0;
+
+    /// @brief Creates or updates subnet level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_id Identifier of a subnet to which option belongs.
+    /// @param option Option to be added or updated.
+    virtual void
+    createUpdateOption4(const db::ServerSelector& server_selector,
+                        const SubnetID& subnet_id,
+                        const OptionDescriptorPtr& option) = 0;
+
+    /// @brief Creates or updates pool level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param pool_start_address Lower bound address of the pool to which
+    /// the option belongs.
+    /// @param pool_end_address Upper bound address of the pool to which the
+    /// option belongs.
+    /// @param option Option to be added or updated.
+    virtual void
+    createUpdateOption4(const db::ServerSelector& server_selector,
+                        const asiolink::IOAddress& pool_start_address,
+                        const asiolink::IOAddress& pool_end_address,
+                        const OptionDescriptorPtr& option) = 0;
+
+    /// @brief Creates or updates global parameter.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param value Value of the global parameter.
+    virtual void
+    createUpdateGlobalParameter4(const db::ServerSelector& server_selector,
+                                 const data::StampedValuePtr& value) = 0;
+
+    /// @brief Creates or updates DHCPv4 client class.
+    ///
+    /// @param server_selector Server selector.
+    /// @param client_class Client class to be added or updated.
+    /// @param follow_class_name name of the class after which the
+    /// new or updated class should be positioned. An empty value
+    /// causes the class to be appended at the end of the class
+    /// hierarchy.
+    virtual void
+    createUpdateClientClass4(const db::ServerSelector& server_selector,
+                             const ClientClassDefPtr& client_class,
+                             const std::string& follow_class_name) = 0;
+
+    /// @brief Creates or updates a server.
+    ///
+    /// @param server Instance of the server to be stored.
+    virtual void
+    createUpdateServer4(const db::ServerPtr& server) = 0;
+
+    /// @brief Deletes subnet by prefix.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_prefix Prefix of the subnet to be deleted.
+    /// @return Number of deleted subnets.
+    virtual uint64_t
+    deleteSubnet4(const db::ServerSelector& server_selector,
+                  const std::string& subnet_prefix) = 0;
+
+    /// @brief Deletes subnet by identifier.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_id Identifier of the subnet to be deleted.
+    /// @return Number of deleted subnets.
+    virtual uint64_t
+    deleteSubnet4(const db::ServerSelector& server_selector, const SubnetID& subnet_id) = 0;
+
+    /// @brief Deletes all subnets.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE.
+    /// Not allowed server selectors: ANY, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Number of deleted subnets.
+    virtual uint64_t
+    deleteAllSubnets4(const db::ServerSelector& server_selector) = 0;
+
+    /// @brief Deletes all subnets belonging to a specified shared network.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param shared_network_name Name of the shared network for which the
+    /// deleted subnets should belongs to.
+    /// @return Number of deleted subnets.
+    virtual uint64_t
+    deleteSharedNetworkSubnets4(const db::ServerSelector& server_selector,
+                                const std::string& shared_network_name) = 0;
+
+    /// @brief Deletes shared network by name.
+    ///
+    /// Allowed server selectors: ANY, UNASSIGNED, ALL, ONE.
+    /// Not allowed server selector: MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param name Name of the shared network to be deleted.
+    /// @return Number of deleted shared networks.
+    virtual uint64_t
+    deleteSharedNetwork4(const db::ServerSelector& server_selector,
+                         const std::string& name) = 0;
+
+    /// @brief Deletes all shared networks.
+    ///
+    /// Allowed server selectors: UNASSIGNED, ALL, ONE.
+    /// Not allowed server selectors: ANY, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Number of deleted shared networks.
+    virtual uint64_t
+    deleteAllSharedNetworks4(const db::ServerSelector& server_selector) = 0;
+
+    /// @brief Deletes option definition.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param code Code of the option to be deleted.
+    /// @param space Option space of the option to be deleted.
+    /// @return Number of deleted option definitions.
+    virtual uint64_t
+    deleteOptionDef4(const db::ServerSelector& server_selector,
+                     const uint16_t code,
+                     const std::string& space) = 0;
+
+    /// @brief Deletes all option definitions.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Number of deleted option definitions.
+    virtual uint64_t
+    deleteAllOptionDefs4(const db::ServerSelector& server_selector) = 0;
+
+    /// @brief Deletes global option.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param code Code of the option to be deleted.
+    /// @param space Option space of the option to be deleted.
+    /// @return Number of deleted options.
+    virtual uint64_t
+    deleteOption4(const db::ServerSelector& server_selector,
+                  const uint16_t code,
+                  const std::string& space) = 0;
+
+    /// @brief Deletes shared network level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param selector Server selector.
+    /// @param shared_network_name Name of the shared network which option
+    /// belongs to.
+    /// @param code Code of the option to be deleted.
+    /// @param space Option space of the option to be deleted.
+    virtual uint64_t
+    deleteOption4(const db::ServerSelector& selector,
+                  const std::string& shared_network_name,
+                  const uint16_t code,
+                  const std::string& space) = 0;
+
+    /// @brief Deletes subnet level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param subnet_id Identifier of the subnet to which deleted option
+    /// belongs.
+    /// @param code Code of the deleted option.
+    /// @param space Option space of the deleted option.
+    /// @return Number of deleted options.
+    virtual uint64_t
+    deleteOption4(const db::ServerSelector& server_selector,
+                  const SubnetID& subnet_id,
+                  const uint16_t code,
+                  const std::string& space) = 0;
+
+    /// @brief Deletes pool level option.
+    ///
+    /// Allowed server selector: ANY.
+    /// Not allowed server selectors: UNASSIGNED, ALL, ONE, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param pool_start_address Lower bound address of the pool to which
+    /// deleted option belongs.
+    /// @param pool_end_address Upper bound address of the pool to which the
+    /// deleted option belongs.
+    /// @param code Code of the deleted option.
+    /// @param space Option space of the deleted option.
+    /// @return Number of deleted options.
+    virtual uint64_t
+    deleteOption4(const db::ServerSelector& server_selector,
+                  const asiolink::IOAddress& pool_start_address,
+                  const asiolink::IOAddress& pool_end_address,
+                  const uint16_t code,
+                  const std::string& space) = 0;
+
+    /// @brief Deletes global parameter.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @param name Name of the global parameter to be deleted.
+    /// @return Number of deleted global parameters.
+    virtual uint64_t
+    deleteGlobalParameter4(const db::ServerSelector& server_selector,
+                           const std::string& name) = 0;
+
+    /// @brief Deletes all global parameters.
+    ///
+    /// Allowed server selectors: ALL, ONE.
+    /// Not allowed server selectors: ANY, UNASSIGNED, MULTIPLE.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Number of deleted global parameters.
+    virtual uint64_t
+    deleteAllGlobalParameters4(const db::ServerSelector& server_selector) = 0;
+
+    /// @brief Deletes DHCPv4 client class.
+    ///
+    /// @param server_selector Server selector.
+    /// @param name Name of the class to be deleted.
+    /// @return Number of deleted client classes.
+    virtual uint64_t
+    deleteClientClass4(const db::ServerSelector& server_selector,
+                       const std::string& name) = 0;
+
+    /// @brief Deletes all client classes.
+    ///
+    /// @param server_selector Server selector.
+    /// @return Number of deleted client classes.
+    virtual uint64_t
+    deleteAllClientClasses4(const db::ServerSelector& server_selector) = 0;
+
+    /// @brief Deletes a server from the backend.
+    ///
+    /// @param server_tag Tag of the server to be deleted.
+    /// @return Number of deleted servers.
+    virtual uint64_t
+    deleteServer4(const data::ServerTag& server_tag) = 0;
+
+    /// @brief Deletes all servers from the backend except the logical
+    /// server 'all'.
+    ///
+    /// @return Number of deleted servers.
+    virtual uint64_t
+    deleteAllServers4() = 0;
+};
+
+/// @brief Shared pointer to the @c ConfigBackendDHCPv4 instance.
+typedef boost::shared_ptr<ConfigBackendDHCPv4> ConfigBackendDHCPv4Ptr;
+
+} // end of namespace isc::dhcp
+} // end of namespace isc
+
+#endif // CONFIG_BACKEND_DHCP4_H