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|
// Copyright (C) 2012-2017 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 MEMFILE_LEASE_MGR_H
#define MEMFILE_LEASE_MGR_H
#include <asiolink/interval_timer.h>
#include <dhcp/hwaddr.h>
#include <dhcpsrv/csv_lease_file4.h>
#include <dhcpsrv/csv_lease_file6.h>
#include <dhcpsrv/memfile_lease_storage.h>
#include <dhcpsrv/database_connection.h>
#include <dhcpsrv/lease_mgr.h>
#include <util/process_spawn.h>
#include <boost/scoped_ptr.hpp>
#include <boost/shared_ptr.hpp>
namespace isc {
namespace dhcp {
class LFCSetup;
/// @brief Concrete implementation of a lease database backend using flat file.
///
/// This class implements a lease database backend using CSV files to store
/// DHCPv4 and DHCPv6 leases on disk. The format of the files is determined
/// by the @c CSVLeaseFile4 and @c CSVLeaseFile6 classes.
///
/// In order to obtain good performance, the backend stores leases
/// incrementally, i.e. updates to leases are appended at the end of the lease
/// file. To record the deletion of a lease, the lease record is appended to
/// the lease file with the valid lifetime set to 0. However, this may result
/// in a significant growth of the lease file size over time, because the lease
/// file will contain many entries for each lease. In order to mitigate this
/// problem, the backend implements the Lease File Cleanup mechanism which is
/// described on the Kea wiki: http://kea.isc.org/wiki/LFCDesign.
///
/// The backend installs an @c asiolink::IntervalTimer to periodically execute
/// the @c Memfile_LeaseMgr::lfcCallback. This callback function controls
/// the startup of the background process which removes redundant information
/// from the lease file(s).
///
/// When the backend is starting up, it reads leases from the lease file (one
/// by one) and adds them to the in-memory container as follows:
/// - if the lease record being parsed identifies a lease which is not present
/// in the container, and the lease has valid lifetime greater than 0,
/// the lease is added to the container,
/// - if the lease record being parsed identifies a lease which is present in
/// the container, and the valid lifetime of the lease record being parsed is
/// greater than 0, the lease in the container is updated
/// - if the lease record being parsed has valid lifetime equal to 0, and the
/// corresponding lease exists in the container, the lease is removed from
/// the container.
///
/// After the container holding leases is initialized, each subsequent update,
/// removal or addition of the lease is appended to the lease file
/// synchronously.
///
/// Originally, the Memfile backend didn't write leases to disk. This was
/// particularly useful for testing server performance in non-disk bound
/// conditions. In order to preserve this capability, the new parameter
/// "persist=true|false" has been introduced in the database access string.
/// For example, database access string: "type=memfile persist=true"
/// enables writes of leases to a disk.
///
/// The lease file locations can be specified with the "name=[path]"
/// parameter in the database access string. The [path] is the
/// absolute path to the file (including file name). If this parameter
/// is not specified, the default location in the installation
/// directory is used: var/kea/kea-leases4.csv and
/// var/kea/kea-leases6.csv.
class Memfile_LeaseMgr : public LeaseMgr {
public:
/// @defgroup versions Specified memfile backend version.
///
/// @brief Defines major version of the memfile backend.
///
/// Version history:
/// 1.0 - initial version (released in Kea 0.9)
/// 2.0 - hwaddr column added (to be released in Kea 0.9.1)
///
/// @{
static const int MAJOR_VERSION = 2;
/// Defines minor version of the memfile backend.
static const int MINOR_VERSION = 0;
/// @}
/// @brief Specifies universe (V4, V6)
///
/// This enumeration is used by various functions in Memfile %Lease Manager,
/// to identify the lease type referred to. In particular, it is used by
/// functions operating on the lease files to distinguish between lease
/// files for DHCPv4 and DHCPv6.
enum Universe {
V4,
V6
};
/// @name Methods implementing the API of the lease database backend.
/// The following methods are implementing the API of the
/// @c LeaseMgr to manage leases.
//@{
/// @brief The sole lease manager constructor
///
/// This method:
/// - Initializes the new instance based on the parameters given
/// - Loads (or creates) the appropriate lease file(s)
/// - Initiates the periodic scheduling of the LFC (if enabled)
///
/// If any of the files loaded require conversion to the current schema
/// (upgrade or downgrade), @c lfcSetup() will be invoked with its
/// @c run_once_now parameter set to true. This causes lfcSetup() to
/// invoke the LFC process immediately regardless of whether LFC is
/// enabled. This ensures that any files which need conversion are
/// converted automatically.
///
/// dbconfig is a generic way of passing parameters. Parameters
/// are passed in the "name=value" format, separated by spaces.
/// Values may be enclosed in double quotes, if needed.
///
/// @param parameters A data structure relating keywords and values
/// concerned with the database.
Memfile_LeaseMgr(const DatabaseConnection::ParameterMap& parameters);
/// @brief Destructor (closes file)
virtual ~Memfile_LeaseMgr();
/// @brief Local version of getDBVersion() class method
static std::string getDBVersion();
/// @brief Adds an IPv4 lease.
///
/// @param lease lease to be added
virtual bool addLease(const Lease4Ptr& lease);
/// @brief Adds an IPv6 lease.
///
/// @param lease lease to be added
virtual bool addLease(const Lease6Ptr& lease);
/// @brief Returns existing IPv4 lease for specified IPv4 address.
///
/// This function returns a copy of the lease. The modification in the
/// return lease does not affect the instance held in the lease storage.
///
/// @param addr An address of the searched lease.
///
/// @return a collection of leases
virtual Lease4Ptr getLease4(const isc::asiolink::IOAddress& addr) const;
/// @brief Returns existing IPv4 leases for specified hardware address.
///
/// Although in the usual case there will be only one lease, for mobile
/// clients or clients with multiple static/fixed/reserved leases there
/// can be more than one. Thus return type is a container, not a single
/// pointer.
///
/// @param hwaddr hardware address of the client
///
/// @return lease collection
virtual Lease4Collection getLease4(const isc::dhcp::HWAddr& hwaddr) const;
/// @brief Returns existing IPv4 lease for specified hardware address
/// and a subnet
///
/// This function returns a copy of the lease. The modification in the
/// return lease does not affect the instance held in the lease storage.
///
/// There can be at most one lease for a given HW address in a single
/// pool, so this method with either return a single lease or NULL.
///
/// @param hwaddr hardware address of the client
/// @param subnet_id identifier of the subnet that lease must belong to
///
/// @return a pointer to the lease (or NULL if a lease is not found)
virtual Lease4Ptr getLease4(const HWAddr& hwaddr,
SubnetID subnet_id) const;
/// @brief Returns existing IPv4 lease for specified client-id
///
/// @param client_id client identifier
virtual Lease4Collection getLease4(const ClientId& client_id) const;
/// @brief Returns IPv4 lease for specified client-id/hwaddr/subnet-id tuple
///
/// There can be at most one lease for a given client-id/hwaddr tuple
/// in a single pool, so this method with either return a single lease
/// or NULL.
///
/// @param clientid client identifier
/// @param hwaddr hardware address of the client
/// @param subnet_id identifier of the subnet that lease must belong to
///
/// @return a pointer to the lease (or NULL if a lease is not found)
virtual Lease4Ptr getLease4(const ClientId& clientid,
const HWAddr& hwaddr,
SubnetID subnet_id) const;
/// @brief Returns existing IPv4 lease for specified client-id
///
/// This function returns a copy of the lease. The modification in the
/// return lease does not affect the instance held in the lease storage.
///
/// There can be at most one lease for a given HW address in a single
/// pool, so this method with either return a single lease or NULL.
///
/// @param clientid client identifier
/// @param subnet_id identifier of the subnet that lease must belong to
///
/// @return a pointer to the lease (or NULL if a lease is not found)
virtual Lease4Ptr getLease4(const ClientId& clientid,
SubnetID subnet_id) const;
/// @brief Returns existing IPv6 lease for a given IPv6 address.
///
/// This function returns a copy of the lease. The modification in the
/// return lease does not affect the instance held in the lease storage.
///
/// @param type specifies lease type: (NA, TA or PD)
/// @param addr An address of the searched lease.
///
/// @return smart pointer to the lease (or NULL if a lease is not found)
virtual Lease6Ptr getLease6(Lease::Type type,
const isc::asiolink::IOAddress& addr) const;
/// @brief Returns existing IPv6 lease for a given DUID + IA + lease type
/// combination
///
/// @param type specifies lease type: (NA, TA or PD)
/// @param duid client DUID
/// @param iaid IA identifier
///
/// @return collection of IPv6 leases
virtual Lease6Collection getLeases6(Lease::Type type,
const DUID& duid, uint32_t iaid) const;
/// @brief Returns existing IPv6 lease for a given DUID + IA + subnet-id +
/// lease type combination.
///
/// This function returns a copy of the lease. The modification in the
/// return lease does not affect the instance held in the lease storage.
///
/// @param type specifies lease type: (NA, TA or PD)
/// @param duid client DUID
/// @param iaid IA identifier
/// @param subnet_id identifier of the subnet the lease must belong to
///
/// @return lease collection (may be empty if no lease is found)
virtual Lease6Collection getLeases6(Lease::Type type, const DUID& duid,
uint32_t iaid,
SubnetID subnet_id) const;
/// @brief Returns a collection of expired DHCPv6 leases.
///
/// This method returns at most @c max_leases expired leases. The leases
/// returned haven't been reclaimed, i.e. the database query must exclude
/// reclaimed leases from the results returned.
///
/// @param [out] expired_leases A container to which expired leases returned
/// by the database backend are added.
/// @param max_leases A maximum number of leases to be returned. If this
/// value is set to 0, all expired (but not reclaimed) leases are returned.
virtual void getExpiredLeases6(Lease6Collection& expired_leases,
const size_t max_leases) const;
/// @brief Returns a collection of expired DHCPv4 leases.
///
/// This method returns at most @c max_leases expired leases. The leases
/// returned haven't been reclaimed, i.e. the database query must exclude
/// reclaimed leases from the results returned.
///
/// @param [out] expired_leases A container to which expired leases returned
/// by the database backend are added.
/// @param max_leases A maximum number of leases to be returned. If this
/// value is set to 0, all expired (but not reclaimed) leases are returned.
virtual void getExpiredLeases4(Lease4Collection& expired_leases,
const size_t max_leases) const;
/// @brief Updates IPv4 lease.
///
/// @warning This function does not validate the pointer to the lease.
/// It is caller's responsibility to pass the valid pointer.
///
/// @param lease4 The lease to be updated.
///
/// If no such lease is present, an exception will be thrown.
virtual void updateLease4(const Lease4Ptr& lease4);
/// @brief Updates IPv6 lease.
///
/// @warning This function does not validate the pointer to the lease.
/// It is caller's responsibility to pass the valid pointer.
///
/// @param lease6 The lease to be updated.
///
/// If no such lease is present, an exception will be thrown.
virtual void updateLease6(const Lease6Ptr& lease6);
/// @brief Deletes a lease.
///
/// @param addr Address of the lease to be deleted. (This can be IPv4 or
/// IPv6.)
///
/// @return true if deletion was successful, false if no such lease exists
virtual bool deleteLease(const isc::asiolink::IOAddress& addr);
/// @brief Deletes all expired-reclaimed DHCPv4 leases.
///
/// @param secs Number of seconds since expiration of leases before
/// they can be removed. Leases which have expired later than this
/// time will not be deleted.
///
/// @return Number of leases deleted.
virtual uint64_t deleteExpiredReclaimedLeases4(const uint32_t secs);
/// @brief Deletes all expired-reclaimed DHCPv6 leases.
///
/// @param secs Number of seconds since expiration of leases before
/// they can be removed. Leases which have expired later than this
/// time will not be deleted.
///
/// @return Number of leases deleted.
virtual uint64_t deleteExpiredReclaimedLeases6(const uint32_t secs);
/// @brief Removes specified IPv4 leases.
///
/// This rather dangerous method is able to remove all leases from specified
/// subnet.
///
/// @param subnet_id identifier of the subnet
/// @return number of leases removed.
virtual size_t wipeLeases4(const SubnetID& subnet_id);
/// @brief Removed specified IPv6 leases.
///
/// This rather dangerous method is able to remove all leases from specified
/// subnet.
///
/// @param subnet_id identifier of the subnet
/// @return number of leases removed.
virtual size_t wipeLeases6(const SubnetID& subnet_id);
private:
/// @brief Deletes all expired-reclaimed leases.
///
/// This private method is called by both of the public methods:
/// @c deleteExpiredReclaimedLeases4 and
/// @c deleteExpiredReclaimedLeases6 to remove all expired
/// reclaimed DHCPv4 or DHCPv6 leases respectively.
///
/// @param secs Number of seconds since expiration of leases before
/// they can be removed. Leases which have expired later than this
/// time will not be deleted.
/// @param universe V4 or V6.
/// @param storage Reference to the container where leases are held.
/// Some expired-reclaimed leases will be removed from this container.
/// @param lease_file Reference to a DHCPv4 or DHCPv6 lease file
/// instance where leases should be marked as deleted.
///
/// @return Number of leases deleted.
///
/// @tparam IndexType Index type to be used to search for the
/// expired-reclaimed leases, i.e.
/// @c Lease4StorageExpirationIndex or @c Lease6StorageExpirationIndex.
/// @tparam LeaseType Lease type, i.e. @c Lease4 or @c Lease6.
/// @tparam StorageType Type of storage where leases are held, i.e.
/// @c Lease4Storage or @c Lease6Storage.
/// @tparam LeaseFileType Type of the lease file, i.e. DHCPv4 or
/// DHCPv6 lease file type.
template<typename IndexType, typename LeaseType, typename StorageType,
typename LeaseFileType>
uint64_t deleteExpiredReclaimedLeases(const uint32_t secs,
const Universe& universe,
StorageType& storage,
LeaseFileType& lease_file) const;
public:
/// @brief Return backend type
///
/// Returns the type of the backend.
///
/// @return Type of the backend.
virtual std::string getType() const {
return (std::string("memfile"));
}
/// @brief Returns backend name.
///
/// For now, memfile can only store data in memory.
///
/// @return Name of the backend.
virtual std::string getName() const {
return ("memory");
}
/// @brief Returns description of the backend.
///
/// This description may be multiline text that describes the backend.
///
/// @return Description of the backend.
virtual std::string getDescription() const;
/// @brief Returns backend version.
///
/// @return Version number as a pair of unsigned integers. "first" is the
/// major version number, "second" the minor number.
virtual std::pair<uint32_t, uint32_t> getVersion() const {
return (std::make_pair(MAJOR_VERSION, MINOR_VERSION));
}
/// @brief Commit Transactions
///
/// Commits all pending database operations. On databases that don't
/// support transactions, this is a no-op.
virtual void commit();
/// @brief Rollback Transactions
///
/// Rolls back all pending database operations. On databases that don't
/// support transactions, this is a no-op.
virtual void rollback();
//@}
/// @name Public type and method used to determine file names for LFC.
//@{
/// @brief Types of the lease files used by the %Lease File Cleanup.
///
/// This enumeration is used by a method which appends the appropriate
/// suffix to the lease file name.
enum LFCFileType {
FILE_CURRENT, ///< %Lease File
FILE_INPUT, ///< %Lease File Copy
FILE_PREVIOUS, ///< Previous %Lease File
FILE_OUTPUT, ///< LFC Output File
FILE_FINISH, ///< LFC Finish File
FILE_PID ///< PID File
};
/// @brief Appends appropriate suffix to the file name.
///
/// The suffix is selected using the LFC file type specified as a
/// parameter. Each file type uses a unique suffix or no suffix:
/// - Current File: no suffix
/// - %Lease File Copy or Input File: ".1"
/// - Previous File: ".2"
/// - LFC Output File: ".output"
/// - LFC Finish File: ".completed"
/// - LFC PID File: ".pid"
///
/// See http://kea.isc.org/wiki/LFCDesign for details.
///
/// @param file_name A base file name to which suffix is appended.
/// @param file_type An LFC file type.
/// @return A lease file name with a suffix appended.
static std::string appendSuffix(const std::string& file_name,
const LFCFileType& file_type);
//@}
/// @name Miscellaneous public convenience methods.
/// The following methods allow for retrieving useful information
/// about the state of the backend.
//@{
/// @brief Returns default path to the lease file.
///
/// @param u Universe (V4 or V6).
std::string getDefaultLeaseFilePath(Universe u) const;
/// @brief Returns an absolute path to the lease file.
///
/// @param u Universe (V4 or V6).
///
/// @return Absolute path to the lease file or empty string if no lease
/// file is used.
std::string getLeaseFilePath(Universe u) const;
/// @brief Specifies whether or not leases are written to disk.
///
/// It is possible that leases for DHCPv4 are written to disk whereas leases
/// for DHCPv6 are not; or vice versa. The argument of the method specifies
/// the type of lease in that respect.
///
/// @param u Universe (V4 or V6).
///
/// @return true if leases are written to lease file; if false is
/// returned, leases will be held in memory and will be lost upon
/// server shut down.
bool persistLeases(Universe u) const;
//@}
private:
/// @brief Initialize the location of the lease file.
///
/// This method uses the parameters passed as a map to the constructor to
/// initialize the location of the lease file. If the lease file is not
/// specified, the method will use the default location for the universe
/// (v4 or v6) selected. If the location is specified in the map as empty
/// or the "persist" parameter is set to "no" it will set the empty
/// location, which implies that leases belonging to the specified universe
/// will not be written to disk.
///
/// @param u Universe (v4 or v6)
///
/// @return The location of the lease file that should be assigned to the
/// lease_file4_ or lease_file6_, depending on the universe specified as an
/// argument to this function.
std::string initLeaseFilePath(Universe u);
/// @brief Load leases from the persistent storage.
///
/// This method loads DHCPv4 or DHCPv6 leases from lease files in the
/// following order:
/// - If the <filename>.completed doesn't exist:
/// - leases from the <filename>.2
/// - leases from the <filename>.1
/// - leases from the <filename>
/// - else
/// - leases from the <filename>.completed
/// - leases from the <filename>
///
/// If any of the files doesn't exist the method proceeds to reading
/// leases from the subsequent file. If the <filename> doesn't exist
/// it is created.
///
/// When the method successfully reads leases from the files, it leaves
/// the file <filename> open and its internal pointer is set to the
/// end of file. The server will append lease entries to this file as
/// a result of processing new messages from the clients.
///
/// The <filename>.2, <filename>.1 and <filename>.completed are the
/// products of the lease file cleanups (LFC).
/// See: http://kea.isc.org/wiki/LFCDesign for details.
///
/// @note: When the server starts up or is reconfigured it will try to
/// read leases from the lease files using this method. It is possible
/// that the %Lease File Cleanup is performed upon the lease files to
/// be read by this method. This may result in conflicts between the
/// server process and the LFC. To prevent it, the method checks if the
/// instance of the @c kea-lfc is running (using the PID file) before it
/// tries to load leases from the lease files. If it finds that there
/// is an LFC in progress, it throws an exception which will result
/// in the server refuse to start or reconfigure. When the administrator
/// retries starting up or reconfiguring the server it will most likely
/// be successful as the LFC should be complete by that time.
///
/// @todo Consider implementing delaying the lease files loading when
/// the LFC is in progress by the specified amount of time.
///
/// @param filename Name of the lease file.
/// @param lease_file An object representing a lease file to which
/// the server will store lease updates.
/// @param storage A storage for leases read from the lease file.
/// @tparam LeaseObjectType @c Lease4 or @c Lease6.
/// @tparam LeaseFileType @c CSVLeaseFile4 or @c CSVLeaseFile6.
/// @tparam StorageType @c Lease4Storage or @c Lease6Storage.
///
/// @return Returns true if any of the files loaded need conversion from
/// an older or newer schema.
///
/// @throw CSVFileError when parsing any of the lease files fails.
/// @throw DbOpenError when it is found that the LFC is in progress.
template<typename LeaseObjectType, typename LeaseFileType,
typename StorageType>
bool loadLeasesFromFiles(const std::string& filename,
boost::shared_ptr<LeaseFileType>& lease_file,
StorageType& storage);
/// @brief stores IPv4 leases
Lease4Storage storage4_;
/// @brief stores IPv6 leases
Lease6Storage storage6_;
/// @brief Holds the pointer to the DHCPv4 lease file IO.
boost::shared_ptr<CSVLeaseFile4> lease_file4_;
/// @brief Holds the pointer to the DHCPv6 lease file IO.
boost::shared_ptr<CSVLeaseFile6> lease_file6_;
public:
/// @name Public methods to retrieve information about the LFC process state.
/// These methods are meant to be used by unit tests to retrieve the
/// state of the spawned LFC process before validating the result of
/// the lease file cleanup.
//@{
/// @brief Checks if the process performing lease file cleanup is running.
///
/// @return true if the process performing lease file cleanup is running.
bool isLFCRunning() const;
/// @brief Returns the status code returned by the last executed
/// LFC process.
int getLFCExitStatus() const;
//@}
/// @brief Creates and runs the IPv4 lease stats query
///
/// It creates an instance of a MemfileLeaseStatsQuery4 and then
/// invokes its start method in which the query constructs its
/// statistical data result set. The query object is then returned.
///
/// @return The populated query as a pointer to an LeaseStatsQuery
virtual LeaseStatsQueryPtr startLeaseStatsQuery4();
/// @brief Creates and runs the IPv6 lease stats query
///
/// It creates an instance of a MemfileLeaseStatsQuery6 and then
/// invokes its start method in which the query constructs its
/// statistical data result set. The query object is then returned.
///
/// @return The populated query as a pointer to an LeaseStatsQuery.
virtual LeaseStatsQueryPtr startLeaseStatsQuery6();
/// @name Protected methods used for %Lease File Cleanup.
/// The following methods are protected so as they can be accessed and
/// tested by unit tests.
//@{
protected:
/// @brief A callback function triggering %Lease File Cleanup (LFC).
///
/// This method is executed periodically to start the lease file cleanup.
/// It checks whether the file is a DHCPv4 lease file or DHCPv6 lease file
/// and executes the @c Memfile_LeaseMgr::lfcExecute private method
/// with the appropriate parameters.
///
/// This method is virtual so as it can be overridden and customized in
/// the unit tests. In particular, the unit test which checks that the
/// callback function has been executed would override this function
/// to increase the execution counter each time it is executed.
virtual void lfcCallback();
//@}
/// @name Private methods and members used for %Lease File Cleanup.
//@{
private:
/// @brief Setup the periodic %Lease File Cleanup.
///
/// This method checks if the @c lfc-interval configuration parameter
/// is set to a non-zero value and sets up the interval timer to
/// perform the %Lease File Cleanup periodically. It also prepares the
/// path and arguments for the @c kea-lfc application which will be
/// executed to perform the cleanup. By default the backend will use
/// the path to the kea-lfc in the Kea installation directory. If
/// the unit tests need to override this path (with the path in the
/// Kea build directory, the @c KEA_LFC_EXECUTABLE environmental
/// variable should be set to hold an absolute path to the kea-lfc
/// executable.
/// @param conversion_needed flag that indicates input lease file(s) are
/// schema do not match the current schema (older or newer), and need
/// conversion. This value is passed through to LFCSetup::setup() via its
/// run_once_now parameter.
void lfcSetup(bool conversion_needed = false);
/// @brief Performs a lease file cleanup for DHCPv4 or DHCPv6.
///
/// This method performs all the actions necessary to prepare for the
/// execution of the LFC and if these actions are successful, it executes
/// the @c kea-lfc application as a background process to process (cleanup)
/// the lease files.
///
/// For the design and the terminology used in this description refer to
/// the http://kea.isc.org/wiki/LFCDesign.
///
/// If the method finds that the %Lease File Copy exists it simply runs
/// the @c kea-lfc application.
///
/// If the %Lease File Copy doesn't exist it moves the Current %Lease File
/// to Lease File Copy, and then recreates the Current Lease File without
/// any lease entries. If the file has been successfully moved, it runs
/// the @c kea-lfc application.
///
/// @param lease_file A pointer to the object representing the Current
/// %Lease File (DHCPv4 or DHCPv6 lease file).
///
/// @tparam LeaseFileType One of @c CSVLeaseFile4 or @c CSVLeaseFile6.
template<typename LeaseFileType>
void lfcExecute(boost::shared_ptr<LeaseFileType>& lease_file);
/// @brief A pointer to the Lease File Cleanup configuration.
boost::scoped_ptr<LFCSetup> lfc_setup_;
/// @brief Parameters storage
///
/// DatabaseConnection object is used only for storing, accessing and
/// printing parameter map.
DatabaseConnection conn_;
//@}
};
}; // end of isc::dhcp namespace
}; // end of isc namespace
#endif // MEMFILE_LEASE_MGR_H
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