Current File : //backups/router/usr/local/include/kea/dhcpsrv/base_host_data_source.h
// Copyright (C) 2014-2023 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 BASE_HOST_DATA_SOURCE_H
#define BASE_HOST_DATA_SOURCE_H
#include <asiolink/io_address.h>
#include <database/database_connection.h>
#include <dhcpsrv/host.h>
#include <exceptions/exceptions.h>
#include <boost/shared_ptr.hpp>
#include <limits>
#include <vector>
namespace isc {
namespace dhcp {
/// @brief Exception thrown when the duplicate @c Host object is detected.
class DuplicateHost : public Exception {
public:
DuplicateHost(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) { };
};
/// @brief Exception thrown when a @c Host object is expected, but none are found.
class HostNotFound : public Exception {
public:
HostNotFound(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) { };
};
/// @brief Exception thrown when an address is already reserved by a @c Host
/// object (DuplicateHost is same identity, ReservedAddress same address).
class ReservedAddress : public Exception {
public:
ReservedAddress(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) { };
};
/// @brief Exception thrown when invalid IP address has been specified for
/// @c Host.
class BadHostAddress : public isc::BadValue {
public:
BadHostAddress(const char* file, size_t line, const char* what) :
isc::BadValue(file, line, what) { };
};
/// @brief Wraps value holding size of the page with host reservations.
class HostPageSize {
public:
/// @brief Constructor.
///
/// @param page_size page size value.
/// @throw OutOfRange if page size is 0 or greater than uint32_t numeric
/// limit.
explicit HostPageSize(const size_t page_size) : page_size_(page_size) {
if (page_size_ == 0) {
isc_throw(OutOfRange, "page size of retrieved hosts must not be 0");
}
if (page_size_ > std::numeric_limits<uint32_t>::max()) {
isc_throw(OutOfRange, "page size of retrieved hosts must not be greate than "
<< std::numeric_limits<uint32_t>::max());
}
}
const size_t page_size_; ///< Holds page size.
};
/// @brief Base interface for the classes implementing simple data source
/// for host reservations.
///
/// This abstract class defines an interface for the classes implementing
/// basic data source for host reservations. This interface allows for
/// adding new reservations (represented by @c Host objects) and retrieving
/// these reservations using various parameters such as HW address or DUID,
/// subnet identifier (either IPv4 or IPv6) or reserved IP address.
///
/// This interface DOES NOT specify the methods to manage existing
/// host reservations such as to remove one IPv6 reservation but leave
/// other reservations. It also lacks the methods used for preparing
/// the data to be added to the SQL database: commit, rollback etc.
/// Such methods are declared in other interfaces.
class BaseHostDataSource {
public:
/// @brief Specifies the type of an identifier.
///
/// This is currently used only by MySQL host data source for now, but
/// it is envisaged that it will be used by other host data sources
/// in the future. Also, this list will grow over time. It is likely
/// that we'll implement other identifiers in the future, e.g. remote-id.
///
/// Those value correspond directly to dhcp_identifier_type in hosts
/// table in MySQL schema.
enum IdType {
ID_HWADDR = 0, ///< Hardware address
ID_DUID = 1 ///< DUID/client-id
};
/// @brief Default destructor implementation.
virtual ~BaseHostDataSource() { }
/// @brief Return all hosts connected to any subnet for which reservations
/// have been made using a specified identifier.
///
/// This method returns all @c Host objects which represent reservations
/// for a specified identifier. This method may return multiple hosts
/// because a particular client may have reservations in multiple subnets.
///
/// @param identifier_type Identifier type.
/// @param identifier_begin Pointer to a beginning of a buffer containing
/// an identifier.
/// @param identifier_len Identifier length.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll(const Host::IdentifierType& identifier_type,
const uint8_t* identifier_begin,
const size_t identifier_len) const = 0;
/// @brief Return all hosts in a DHCPv4 subnet.
///
/// This method returns all @c Host objects which represent reservations
/// in a specified subnet.
///
/// @param subnet_id Subnet identifier.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll4(const SubnetID& subnet_id) const = 0;
/// @brief Return all hosts in a DHCPv6 subnet.
///
/// This method returns all @c Host objects which represent reservations
/// in a specified subnet.
///
/// @param subnet_id Subnet identifier.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll6(const SubnetID& subnet_id) const = 0;
/// @brief Return all hosts with a hostname.
///
/// This method returns all @c Host objects which represent reservations
/// using a specified hostname.
///
/// @note: as hostnames are case-insensitive the search key is given
/// in lower cases, search indexes should either be case-insensitive
/// or be case-sensitive using the lower case version of hostnames.
///
/// @param hostname The lower case hostname.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAllbyHostname(const std::string& hostname) const = 0;
/// @brief Return all hosts with a hostname in a DHCPv4 subnet.
///
/// This method returns all @c Host objects which represent reservations
/// using a specified hostname in a specified subnet.
///
/// @param hostname The lower case hostname.
/// @param subnet_id Subnet identifier.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAllbyHostname4(const std::string& hostname, const SubnetID& subnet_id) const = 0;
/// @brief Return all hosts with a hostname in a DHCPv6 subnet.
///
/// This method returns all @c Host objects which represent reservations
/// using a specified hostname in a specified subnet.
///
/// @param hostname The lower case hostname.
/// @param subnet_id Subnet identifier.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAllbyHostname6(const std::string& hostname, const SubnetID& subnet_id) const = 0;
/// @brief Returns range of hosts in a DHCPv4 subnet.
///
/// This method implements paged browsing of host databases. The
/// parameters specify a page size, an index in sources and the
/// starting host id of the range. If not zero this host id is
/// excluded from the returned range. When a source is exhausted
/// the index is updated. There is no guarantee about the order
/// of returned host reservations, only the sources and
/// reservations from the same source are ordered.
///
/// @param subnet_id Subnet identifier.
/// @param source_index Index of the source.
/// @param lower_host_id Host identifier used as lower bound for the
/// returned range.
/// @param page_size maximum size of the page returned.
///
/// @return Host collection (may be empty).
virtual ConstHostCollection
getPage4(const SubnetID& subnet_id,
size_t& source_index,
uint64_t lower_host_id,
const HostPageSize& page_size) const = 0;
/// @brief Returns range of hosts in a DHCPv6 subnet.
///
/// This method implements paged browsing of host databases. The
/// parameters specify a page size, an index in sources and the
/// starting host id of the range. If not zero this host id is
/// excluded from the returned range. When a source is exhausted
/// the index is updated. There is no guarantee about the order
/// of returned host reservations, only the sources and
/// reservations from the same source are ordered.
///
/// @param subnet_id Subnet identifier.
/// @param source_index Index of the source.
/// @param lower_host_id Host identifier used as lower bound for the
/// returned range.
/// @param page_size maximum size of the page returned.
///
/// @return Host collection (may be empty).
virtual ConstHostCollection
getPage6(const SubnetID& subnet_id,
size_t& source_index,
uint64_t lower_host_id,
const HostPageSize& page_size) const = 0;
/// @brief Returns range of hosts.
///
/// This method implements paged browsing of host databases. The
/// parameters specify a page size, an index in sources and the
/// starting host id of the range. If not zero this host id is
/// excluded from the returned range. When a source is exhausted
/// the index is updated. There is no guarantee about the order
/// of returned host reservations, only the sources and
/// reservations from the same source are ordered.
///
/// @param source_index Index of the source.
/// @param lower_host_id Host identifier used as lower bound for the
/// returned range.
/// @param page_size maximum size of the page returned.
///
/// @return Host collection (may be empty).
virtual ConstHostCollection
getPage4(size_t& source_index,
uint64_t lower_host_id,
const HostPageSize& page_size) const = 0;
/// @brief Returns range of hosts.
///
/// This method implements paged browsing of host databases. The
/// parameters specify a page size, an index in sources and the
/// starting host id of the range. If not zero this host id is
/// excluded from the returned range. When a source is exhausted
/// the index is updated. There is no guarantee about the order
/// of returned host reservations, only the sources and
/// reservations from the same source are ordered.
///
/// @param source_index Index of the source.
/// @param lower_host_id Host identifier used as lower bound for the
/// returned range.
/// @param page_size maximum size of the page returned.
///
/// @return Host collection (may be empty).
virtual ConstHostCollection
getPage6(size_t& source_index,
uint64_t lower_host_id,
const HostPageSize& page_size) const = 0;
/// @brief Returns a collection of hosts using the specified IPv4 address.
///
/// This method may return multiple @c Host objects if they are connected
/// to different subnets.
///
/// @param address IPv4 address for which the @c Host object is searched.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll4(const asiolink::IOAddress& address) const = 0;
/// @brief Returns a host connected to the IPv4 subnet.
///
/// @param subnet_id Subnet identifier.
/// @param identifier_type Identifier type.
/// @param identifier_begin Pointer to a beginning of a buffer containing
/// an identifier.
/// @param identifier_len Identifier length.
///
/// @return Const @c Host object for which reservation has been made using
/// the specified identifier.
virtual ConstHostPtr
get4(const SubnetID& subnet_id,
const Host::IdentifierType& identifier_type,
const uint8_t* identifier_begin,
const size_t identifier_len) const = 0;
/// @brief Returns a host connected to the IPv4 subnet and having
/// a reservation for a specified IPv4 address.
///
/// One of the use cases for this method is to detect collisions between
/// dynamically allocated addresses and reserved addresses. When the new
/// address is assigned to a client, the allocation mechanism should check
/// if this address is not reserved for some other host and do not allocate
/// this address if reservation is present.
///
/// Implementations of this method should guard against invalid addresses,
/// such as IPv6 address.
///
/// @param subnet_id Subnet identifier.
/// @param address reserved IPv4 address.
///
/// @return Const @c Host object using a specified IPv4 address.
virtual ConstHostPtr
get4(const SubnetID& subnet_id,
const asiolink::IOAddress& address) const = 0;
/// @brief Returns all hosts connected to the IPv4 subnet and having
/// a reservation for a specified address.
///
/// In most cases it is desired that there is at most one reservation
/// for a given IPv4 address within a subnet. In a default configuration,
/// the backend does not allow for inserting more than one host with
/// the same IPv4 reservation. In that case, the number of hosts returned
/// by this function is 0 or 1.
///
/// If the backend is configured to allow multiple hosts with reservations
/// for the same IPv4 address in the given subnet, this method can return
/// more than one host.
///
/// The typical use case when a single IPv4 address is reserved for multiple
/// hosts is when these hosts represent different interfaces of the same
/// machine and each interface comes with a different MAC address. In that
/// case, the same IPv4 address is assigned regardless of which interface is
/// used by the DHCP client to communicate with the server.
///
/// @param subnet_id Subnet identifier.
/// @param address reserved IPv4 address
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll4(const SubnetID& subnet_id,
const asiolink::IOAddress& address) const = 0;
/// @brief Returns a host connected to the IPv6 subnet.
///
/// @param subnet_id Subnet identifier.
/// @param identifier_type Identifier type.
/// @param identifier_begin Pointer to a beginning of a buffer containing
/// an identifier.
/// @param identifier_len Identifier length.
///
/// @return Const @c Host object for which reservation has been made using
/// the specified identifier.
virtual ConstHostPtr
get6(const SubnetID& subnet_id,
const Host::IdentifierType& identifier_type,
const uint8_t* identifier_begin,
const size_t identifier_len) const = 0;
/// @brief Returns a host using the specified IPv6 prefix.
///
/// @param prefix IPv6 prefix for which the @c Host object is searched.
/// @param prefix_len IPv6 prefix length.
///
/// @return Const @c Host object using a specified IPv6 prefix.
virtual ConstHostPtr
get6(const asiolink::IOAddress& prefix, const uint8_t prefix_len) const = 0;
/// @brief Returns a host connected to the IPv6 subnet and having
/// a reservation for a specified IPv6 address or prefix.
///
/// @param subnet_id Subnet identifier.
/// @param address reserved IPv6 address/prefix.
///
/// @return Const @c Host object using a specified IPv6 address/prefix.
virtual ConstHostPtr
get6(const SubnetID& subnet_id, const asiolink::IOAddress& address) const = 0;
/// @brief Returns all hosts connected to the IPv6 subnet and having
/// a reservation for a specified address or delegated prefix (lease).
///
/// In most cases it is desired that there is at most one reservation
/// for a given IPv6 lease within a subnet. In a default configuration,
/// the backend does not allow for inserting more than one host with
/// the same IPv6 address or prefix. In that case, the number of hosts
/// returned by this function is 0 or 1.
///
/// If the backend is configured to allow multiple hosts with reservations
/// for the same IPv6 lease in the given subnet, this method can return
/// more than one host.
///
/// The typical use case when a single IPv6 lease is reserved for multiple
/// hosts is when these hosts represent different interfaces of the same
/// machine and each interface comes with a different MAC address. In that
/// case, the same IPv6 lease is assigned regardless of which interface is
/// used by the DHCP client to communicate with the server.
///
/// @param subnet_id Subnet identifier.
/// @param address reserved IPv6 address/prefix.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll6(const SubnetID& subnet_id,
const asiolink::IOAddress& address) const = 0;
/// @brief Returns all hosts having a reservation for a specified
/// address or delegated prefix (lease) in all subnets.
///
/// In most cases it is desired that there is at most one reservation
/// for a given IPv6 lease within a subnet. In a default configuration,
/// the backend does not allow for inserting more than one host with
/// the same IPv6 address or prefix.
///
/// If the backend is configured to allow multiple hosts with reservations
/// for the same IPv6 lease in the given subnet, this method can return
/// more than one host per subnet.
///
/// The typical use case when a single IPv6 lease is reserved for multiple
/// hosts is when these hosts represent different interfaces of the same
/// machine and each interface comes with a different MAC address. In that
/// case, the same IPv6 lease is assigned regardless of which interface is
/// used by the DHCP client to communicate with the server.
///
/// @param address reserved IPv6 address/prefix.
///
/// @return Collection of const @c Host objects.
virtual ConstHostCollection
getAll6(const asiolink::IOAddress& address) const = 0;
/// @brief Adds a new host to the collection.
///
/// The implementations of this method should guard against duplicate
/// reservations for the same host, where possible. For example, when the
/// reservation for the same HW address and subnet id is added twice, the
/// implementation should throw an exception. Note, that usually it is
/// impossible to guard against adding duplicated host, where one instance
/// is identified by HW address, another one by DUID.
///
/// @param host Pointer to the new @c Host object being added.
virtual void add(const HostPtr& host) = 0;
/// @brief Attempts to delete hosts by (subnet-id, address)
///
/// This method supports both v4 and v6.
///
/// @param subnet_id subnet identifier.
/// @param addr specified address.
/// @return true if deletion was successful, false if the host was not there.
/// @throw various exceptions in case of errors
virtual bool del(const SubnetID& subnet_id, const asiolink::IOAddress& addr) = 0;
/// @brief Attempts to delete a host by (subnet-id4, identifier, identifier-type)
///
/// This method supports v4 hosts only.
///
/// @param subnet_id IPv4 Subnet identifier.
/// @param identifier_type Identifier type.
/// @param identifier_begin Pointer to a beginning of a buffer containing
/// an identifier.
/// @param identifier_len Identifier length.
/// @return true if deletion was successful, false if the host was not there.
/// @throw various exceptions in case of errors
virtual bool del4(const SubnetID& subnet_id,
const Host::IdentifierType& identifier_type,
const uint8_t* identifier_begin, const size_t identifier_len) = 0;
/// @brief Attempts to delete a host by (subnet-id6, identifier, identifier-type)
///
/// This method supports v6 hosts only.
///
/// @param subnet_id IPv6 Subnet identifier.
/// @param identifier_type Identifier type.
/// @param identifier_begin Pointer to a beginning of a buffer containing
/// an identifier.
/// @param identifier_len Identifier length.
/// @return true if deletion was successful, false if the host was not there.
/// @throw various exceptions in case of errors
virtual bool del6(const SubnetID& subnet_id,
const Host::IdentifierType& identifier_type,
const uint8_t* identifier_begin, const size_t identifier_len) = 0;
/// @brief Attempts to update an existing host entry.
///
/// The implementation is common to multiple host data sources, so let's
/// provide it in the base host data source. In some instances, it may
/// require synchronization e.g. with transactions in case of databases.
///
/// @param host the host up to date with the requested changes
virtual void update(HostPtr const& host) {
bool deleted(false);
if (host->getIPv4SubnetID() != SUBNET_ID_UNUSED) {
std::vector<uint8_t> const& identifier(host->getIdentifier());
deleted = del4(host->getIPv4SubnetID(), host->getIdentifierType(), identifier.data(),
identifier.size());
} else if (host->getIPv6SubnetID() != SUBNET_ID_UNUSED) {
std::vector<uint8_t> const& identifier(host->getIdentifier());
deleted = del6(host->getIPv6SubnetID(), host->getIdentifierType(), identifier.data(),
identifier.size());
} else {
isc_throw(HostNotFound, "Mandatory 'subnet-id' parameter missing.");
}
if (!deleted) {
isc_throw(HostNotFound, "Host not updated (not found).");
}
add(host);
}
/// @brief Return backend type
///
/// Returns the type of the backend (e.g. "mysql", "memfile" etc.)
///
/// @return Type of the backend.
virtual std::string getType() const = 0;
/// @brief Return backend parameters
///
/// Returns the backend parameters
///
/// @return Parameters of the backend.
virtual isc::db::DatabaseConnection::ParameterMap getParameters() const {
return (isc::db::DatabaseConnection::ParameterMap());
}
/// @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() {};
/// @brief Controls whether IP reservations are unique or non-unique.
///
/// In a typical case, the IP reservations are unique and backends verify
/// prior to adding a host reservation to the database that the reservation
/// for a given IP address/subnet does not exist. In some cases it may be
/// required to allow non-unique IP reservations, e.g. in the case when a
/// host has several interfaces and independently of which interface is used
/// by this host to communicate with the DHCP server the same IP address
/// should be assigned. In this case the @c unique value should be set to
/// false to disable the checks for uniqueness on the backend side.
///
/// All backends are required to support the case when unique setting is
/// @c true and they must use this setting by default.
///
/// @param unique boolean flag indicating if the IP reservations must be
/// unique or can be non-unique.
/// @return true if the new setting was accepted by the backend or false
/// otherwise.
virtual bool setIPReservationsUnique(const bool unique) = 0;
/// @brief Flag which indicates if the host manager has at least one
/// unusable connection.
///
/// @return true if there is at least one unusable connection, false
/// otherwise
virtual bool isUnusable() {
return (false);
}
};
/// @brief HostDataSource pointer
typedef boost::shared_ptr<BaseHostDataSource> HostDataSourcePtr;
/// @brief HostDataSource list
typedef std::vector<HostDataSourcePtr> HostDataSourceList;
} // namespace dhcp
} // namespace isc
#endif // BASE_HOST_DATA_SOURCE_H
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