Adding upstream version 2.4.1.upstream/2.4.1upstream

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

1 files changed, 1079 insertions, 0 deletions

diff --git a/src/lib/dhcpsrv/parsers/dhcp_parsers.h b/src/lib/dhcpsrv/parsers/dhcp_parsers.h
new file mode 100644
index 0000000..b416539
--- /dev/null
+++ b/src/lib/dhcpsrv/parsers/dhcp_parsers.h
@@ -0,0 +1,1079 @@
+// Copyright (C) 2013-2023 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 DHCP_PARSERS_H
+#define DHCP_PARSERS_H
+
+#include <asiolink/io_address.h>
+#include <cc/data.h>
+#include <dhcp/option_definition.h>
+#include <dhcp/option_space_container.h>
+#include <dhcpsrv/d2_client_cfg.h>
+#include <dhcpsrv/cfg_iface.h>
+#include <dhcpsrv/cfg_option.h>
+#include <dhcpsrv/network.h>
+#include <dhcpsrv/subnet.h>
+#include <dhcpsrv/cfg_option_def.h>
+#include <dhcpsrv/cfg_mac_source.h>
+#include <dhcpsrv/srv_config.h>
+#include <dhcpsrv/parsers/base_network_parser.h>
+#include <dhcpsrv/parsers/option_data_parser.h>
+#include <cc/simple_parser.h>
+#include <exceptions/exceptions.h>
+#include <util/optional.h>
+
+#include <boost/shared_ptr.hpp>
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+namespace isc {
+namespace dhcp {
+
+/// Collection of containers holding option spaces. Each container within
+/// a particular option space holds so-called option descriptors.
+typedef OptionSpaceContainer<OptionContainer, OptionDescriptor,
+                             std::string> OptionStorage;
+/// @brief Shared pointer to option storage.
+typedef boost::shared_ptr<OptionStorage> OptionStoragePtr;
+
+/// @brief A template class that stores named elements of a given data type.
+///
+/// This template class is provides data value storage for configuration
+/// parameters of a given data type.  The values are stored by parameter name
+/// and as instances of type "ValueType". Each value held in the storage has
+/// a corresponding position within a configuration string (file) specified
+/// as a: file name, line number and position within the line. The position
+/// information is used for logging when the particular configuration value
+/// causes a configuration error.
+///
+/// @tparam ValueType is the data type of the elements to store.
+template<typename ValueType>
+class ValueStorage {
+public:
+    /// @brief  Stores the parameter, its value and the position in the
+    /// store.
+    ///
+    /// If the parameter does not exist in the store, then it will be added,
+    /// otherwise its data value and the position will be updated with the
+    /// given values.
+    ///
+    /// @param name is the name of the parameter to store.
+    /// @param value is the data value to store.
+    /// @param position is the position of the data element within a
+    /// configuration string (file).
+    void setParam(const std::string& name, const ValueType& value,
+                  const data::Element::Position& position) {
+        values_[name] = value;
+        positions_[name] = position;
+    }
+
+    /// @brief Returns the data value for the given parameter.
+    ///
+    /// Finds and returns the data value for the given parameter.
+    /// @param name is the name of the parameter for which the data
+    /// value is desired.
+    ///
+    /// @return The parameter's data value of type @c ValueType.
+    /// @throw DhcpConfigError if the parameter is not found.
+    ValueType getParam(const std::string& name) const {
+        typename std::map<std::string, ValueType>::const_iterator param
+            = values_.find(name);
+
+        if (param == values_.end()) {
+            isc_throw(DhcpConfigError, "Missing parameter '"
+                      << name << "'");
+        }
+
+        return (param->second);
+    }
+
+    /// @brief Returns position of the data element in the configuration string.
+    ///
+    /// The returned object comprises file name, line number and the position
+    /// within the particular line of the configuration string where the data
+    /// element holding a particular value is located.
+    ///
+    /// @param name is the name of the parameter which position is desired.
+    /// @param parent Pointer to a data element which position should be
+    /// returned when position of the specified parameter is not found.
+    ///
+    /// @return Position of the data element or the position holding empty
+    /// file name and two zeros if the position hasn't been specified for the
+    /// particular value.
+    const data::Element::Position&
+    getPosition(const std::string& name, const data::ConstElementPtr parent =
+                data::ConstElementPtr()) const {
+        typename std::map<std::string, data::Element::Position>::const_iterator
+            pos = positions_.find(name);
+        if (pos == positions_.end()) {
+            return (parent ? parent->getPosition() :
+                    data::Element::ZERO_POSITION());
+        }
+
+        return (pos->second);
+    }
+
+    /// @brief Returns the data value for an optional parameter.
+    ///
+    /// Finds and returns the data value for the given parameter or
+    /// a supplied default value if it is not found.
+    ///
+    /// @param name is the name of the parameter for which the data
+    /// value is desired.
+    /// @param default_value value to use the default
+    ///
+    /// @return The parameter's data value of type @c ValueType.
+    ValueType getOptionalParam(const std::string& name,
+                               const ValueType& default_value) const {
+        typename std::map<std::string, ValueType>::const_iterator param
+            = values_.find(name);
+
+        if (param == values_.end()) {
+            return (default_value);
+        }
+
+        return (param->second);
+    }
+
+    /// @brief  Remove the parameter from the store.
+    ///
+    /// Deletes the entry for the given parameter from the store if it
+    /// exists.
+    ///
+    /// @param name is the name of the parameter to delete.
+    void delParam(const std::string& name) {
+        values_.erase(name);
+        positions_.erase(name);
+    }
+
+    /// @brief Deletes all of the entries from the store.
+    ///
+    void clear() {
+        values_.clear();
+        positions_.clear();
+    }
+
+private:
+    /// @brief An std::map of the data values, keyed by parameter names.
+    std::map<std::string, ValueType> values_;
+
+    /// @brief An std::map holding positions of the data elements in the
+    /// configuration, which values are held in @c values_.
+    ///
+    /// The position is used for logging, when the particular value
+    /// causes a configuration error.
+    std::map<std::string, data::Element::Position> positions_;
+
+};
+
+/// @brief Combination of parameter name and configuration contents
+typedef std::pair<std::string, isc::data::ConstElementPtr> ConfigPair;
+
+/// @brief a collection of elements that store uint32 values
+typedef ValueStorage<uint32_t> Uint32Storage;
+typedef boost::shared_ptr<Uint32Storage> Uint32StoragePtr;
+
+/// @brief a collection of elements that store string values
+typedef ValueStorage<std::string> StringStorage;
+typedef boost::shared_ptr<StringStorage> StringStoragePtr;
+
+/// @brief Storage for parsed boolean values.
+typedef ValueStorage<bool> BooleanStorage;
+typedef boost::shared_ptr<BooleanStorage> BooleanStoragePtr;
+
+/// @brief parser for MAC/hardware acquisition sources
+///
+/// This parser handles Dhcp6/mac-sources entry.
+/// It contains a list of MAC/hardware acquisition source, i.e. methods how
+/// MAC address can possibly by obtained in DHCPv6. For a currently supported
+/// methods, see @ref isc::dhcp::Pkt::getMAC.
+class MACSourcesListConfigParser : public isc::data::SimpleParser {
+public:
+    /// @brief parses parameters value
+    ///
+    /// Parses configuration entry (list of sources) and adds each element
+    /// to the sources list.
+    ///
+    /// @param value pointer to the content of parsed values
+    /// @param mac_sources parsed sources will be stored here
+    void parse(CfgMACSource& mac_sources, isc::data::ConstElementPtr value);
+};
+
+/// @brief Parser for the control-socket structure
+///
+/// It does not parse anything, simply stores the element in
+/// the staging config.
+class ControlSocketParser : public isc::data::SimpleParser {
+public:
+    /// @brief "Parses" control-socket structure
+    ///
+    /// Since the SrvConfig structure takes the socket definition
+    /// as ConstElementPtr, there's really nothing to parse here.
+    /// It only does basic sanity checks and throws DhcpConfigError
+    /// if the value is null or is not a map.
+    ///
+    /// @param srv_cfg parsed values will be stored here
+    /// @param value pointer to the content of parsed values
+    void parse(SrvConfig& srv_cfg, isc::data::ConstElementPtr value);
+};
+
+/// @brief Parser for a single option definition.
+///
+/// This parser creates an instance of a single option definition.
+class OptionDefParser : public isc::data::SimpleParser {
+public:
+    /// @brief Constructor.
+    ///
+    /// @param address_family Address family: @c AF_INET or @c AF_INET6.
+    OptionDefParser(const uint16_t address_family);
+
+    /// @brief Parses an entry that describes single option definition.
+    ///
+    /// @param option_def a configuration entry to be parsed.
+    /// @return option definition of the parsed structure.
+    ///
+    /// @throw DhcpConfigError if parsing was unsuccessful.
+    OptionDefinitionPtr parse(isc::data::ConstElementPtr option_def);
+
+private:
+    /// @brief Address family: @c AF_INET or @c AF_INET6.
+    uint16_t address_family_;
+};
+
+/// @brief Parser for a list of option definitions.
+///
+/// This parser iterates over all configuration entries that define
+/// option definitions and creates instances of these definitions.
+/// If the parsing is successful, the collection of created definitions
+/// is put into the provided storage.
+class OptionDefListParser : public isc::data::SimpleParser {
+public:
+    /// @brief Constructor.
+    ///
+    /// @param address_family Address family: @c AF_INET or @c AF_INET6.
+    OptionDefListParser(const uint16_t address_family);
+
+    /// @brief Parses a list of option definitions, create them and store in cfg
+    ///
+    /// This method iterates over def_list, which is a JSON list of option definitions,
+    /// then creates corresponding option definitions and store them in the
+    /// configuration structure.
+    ///
+    /// @param def_list JSON list describing option definitions
+    /// @param cfg parsed option definitions will be stored here
+    void parse(CfgOptionDefPtr cfg, isc::data::ConstElementPtr def_list);
+
+private:
+    /// @brief Address family: @c AF_INET or @c AF_INET6.
+    uint16_t address_family_;
+};
+
+/// @brief a collection of pools
+///
+/// That type is used as intermediate storage, when pools are parsed, but there is
+/// no subnet object created yet to store them.
+typedef std::vector<PoolPtr> PoolStorage;
+typedef boost::shared_ptr<PoolStorage> PoolStoragePtr;
+
+/// @brief parser for a single pool definition
+///
+/// This abstract parser handles pool definitions, i.e. a list of entries of one
+/// of two syntaxes: min-max and prefix/len. Pool objects are created
+/// and stored in chosen PoolStorage container.
+///
+/// It is useful for parsing Dhcp<4/6>/subnet<4/6>[X]/pools[X] structure.
+class PoolParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief destructor.
+    virtual ~PoolParser() {
+    }
+
+    /// @brief parses the actual structure
+    ///
+    /// This method parses the actual list of interfaces.
+    /// No validation is done at this stage, everything is interpreted as
+    /// interface name.
+    /// @param pools is the storage in which to store the parsed pool
+    /// @param pool_structure a single entry on a list of pools
+    /// @param address_family AF_INET (for DHCPv4) or AF_INET6 (for DHCPv6).
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @throw isc::dhcp::DhcpConfigError when pool parsing fails
+    virtual void parse(PoolStoragePtr pools,
+                       isc::data::ConstElementPtr pool_structure,
+                       const uint16_t address_family,
+                       bool encapsulate_options = true);
+
+protected:
+    /// @brief Creates a Pool object given a IPv4 prefix and the prefix length.
+    ///
+    /// @param addr is the IP  prefix of the pool.
+    /// @param len is the prefix length.
+    /// @param ptype is the type of pool to create.
+    /// @return returns a PoolPtr to the new Pool object.
+    virtual PoolPtr poolMaker(isc::asiolink::IOAddress &addr, uint32_t len,
+                              int32_t ptype = 0) = 0;
+
+    /// @brief Creates a Pool object given starting and ending IP addresses.
+    ///
+    /// @param min is the first IP address in the pool.
+    /// @param max is the last IP address in the pool.
+    /// @param ptype is the type of pool to create (not used by all derivations)
+    /// @return returns a PoolPtr to the new Pool object.
+    virtual PoolPtr poolMaker(isc::asiolink::IOAddress &min,
+                              isc::asiolink::IOAddress &max,
+                              int32_t ptype = 0) = 0;
+
+    /// @brief Returns an instance of the @c OptionDataListParser to
+    /// be used in parsing the option-data structure.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for option data.
+    ///
+    /// @param address_family AF_INET (for DHCPv4) or AF_INET6 (for DHCPv6).
+    ///
+    /// @return an instance of the @c OptionDataListParser.
+    virtual boost::shared_ptr<OptionDataListParser>
+    createOptionDataListParser(const uint16_t address_family) const;
+};
+
+/// @brief Parser for IPv4 pool definitions.
+///
+/// This is the IPv4 derivation of the PoolParser class and handles pool
+/// definitions, i.e. a list of entries of one of two syntaxes: min-max and
+/// prefix/len for IPv4 pools. Pool4 objects are created and stored in chosen
+/// PoolStorage container.
+///
+/// It is useful for parsing Dhcp4/subnet4[X]/pool parameters.
+class Pool4Parser : public PoolParser {
+protected:
+    /// @brief Creates a Pool4 object given a IPv4 prefix and the prefix length.
+    ///
+    /// @param addr is the IPv4 prefix of the pool.
+    /// @param len is the prefix length.
+    /// @param ignored dummy parameter to provide symmetry between the
+    /// PoolParser derivations. The V6 derivation requires a third value.
+    /// @return returns a PoolPtr to the new Pool4 object.
+    PoolPtr poolMaker (asiolink::IOAddress &addr, uint32_t len,
+                       int32_t ignored);
+
+    /// @brief Creates a Pool4 object given starting and ending IPv4 addresses.
+    ///
+    /// @param min is the first IPv4 address in the pool.
+    /// @param max is the last IPv4 address in the pool.
+    /// @param ignored dummy parameter to provide symmetry between the
+    /// PoolParser derivations. The V6 derivation requires a third value.
+    /// @return returns a PoolPtr to the new Pool4 object.
+    PoolPtr poolMaker (asiolink::IOAddress &min, asiolink::IOAddress &max,
+                       int32_t ignored);
+};
+
+/// @brief Parser for a list of pools
+///
+/// This parser parses a list pools. Each element on that list gets its own
+/// parser, created with poolParserMaker() method. That method must be specified
+/// for each protocol family (v4 or v6) separately.
+class PoolsListParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief destructor.
+    virtual ~PoolsListParser() {
+    }
+
+    /// @brief parses the actual structure
+    ///
+    /// This method parses the actual list of pools.
+    ///
+    /// @param pools is the storage in which to store the parsed pools.
+    /// @param pools_list a list of pool structures
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @throw isc::dhcp::DhcpConfigError when pool parsing fails
+    virtual void parse(PoolStoragePtr pools,
+                       isc::data::ConstElementPtr pools_list,
+                       bool encapsulate_options) = 0;
+
+protected:
+
+    /// @brief Returns an instance of the @c PoolParser to be used in
+    /// parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c PoolParser.
+    virtual boost::shared_ptr<PoolParser> createPoolConfigParser() const = 0;
+};
+
+/// @brief Specialization of the pool list parser for DHCPv4
+class Pools4ListParser : public PoolsListParser {
+public:
+
+    /// @brief parses the actual structure
+    ///
+    /// This method parses the actual list of pools.
+    ///
+    /// @param pools storage container in which to store the parsed pool.
+    /// @param pools_list a list of pool structures
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @throw isc::dhcp::DhcpConfigError when pool parsing fails
+    void parse(PoolStoragePtr pools, data::ConstElementPtr pools_list,
+               bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Returns an instance of the @c Pool4Parser to be used in
+    /// parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c Pool4Parser.
+    virtual boost::shared_ptr<PoolParser> createPoolConfigParser() const;
+};
+
+/// @brief parser for additional relay information
+///
+/// This concrete parser handles RelayInfo structure definitions.
+/// So far that structure holds only relay IP (v4 or v6) address, but it
+/// is expected that the number of parameters will increase over time.
+///
+/// It is useful for parsing Dhcp<4/6>/subnet<4/6>[x]/relay parameters.
+class RelayInfoParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief constructor
+    /// @param family specifies protocol family (IPv4 or IPv6)
+    explicit RelayInfoParser(const isc::dhcp::Option::Universe& family);
+
+    /// @brief parses the actual relay parameters
+    ///
+    /// The elements currently supported are:
+    /// -# ip-address
+    /// -# ip-addresses
+    ///
+    /// Note that ip-address and ip-addresses are mutually exclusive, with
+    /// former being deprecated.  The use of ip-address will cause an debug
+    /// log to be emitted, reminded users to switch.
+    ///
+    /// @param relay_info configuration will be stored here
+    /// @param relay_elem Element tree containing the relay and its members
+    /// @throw isc::dhcp::DhcpConfigError if both or neither of ip-address
+    /// and ip-addresses are specified.
+    void parse(const isc::dhcp::Network::RelayInfoPtr& relay_info,
+               isc::data::ConstElementPtr relay_elem);
+
+    /// @brief Attempts to add an IP address to list of relay addresses
+    ///
+    /// @param name name of the element supplying the address string, (either
+    /// "ip-address" or "ip-addresses")
+    /// @param address_str string form of the IP address to add
+    /// @param relay_elem parent relay element (needed for position info)
+    /// @param relay_info RelayInfo to which the address should be added
+    /// @throw isc::dhcp::DhcpConfigError if the address string is not a valid
+    /// IP address, is an address of the wrong family, or is already in the
+    /// relay address list
+    void addAddress(const std::string& name, const std::string& address_str,
+                    isc::data::ConstElementPtr relay_elem,
+                    const isc::dhcp::Network::RelayInfoPtr& relay_info);
+private:
+
+    /// Protocol family (IPv4 or IPv6)
+    Option::Universe family_;
+};
+
+/// @brief this class parses a single subnet
+///
+/// There are dedicated @ref Subnet4ConfigParser and @ref Subnet6ConfigParser
+/// classes. They provide specialized parse() methods that return Subnet4Ptr
+/// or Subnet6Ptr.
+///
+/// This class parses the whole subnet definition. This class attempts to
+/// unify the code between v4 and v6 as much as possible. As a result, the flow
+/// is somewhat complex and it looks as follows:
+///
+///     ------- Base class
+///    /
+///    | /----- Derived class
+/// 1.   * SubnetXConfigParser::parse() is called.
+/// 2. *   SubnetConfigParser::parse() is called.
+/// 3. *   SubnetConfigParser::createSubnet() is called.
+/// 4.   * SubnetXConfigParser::initSubnet() is called (Subnet4 or Subnet6 is
+///        instantiated here and family specific parameters are set)
+/// 5.     Control returns to createSubnet() (step 3) and common parameters
+///        are set.
+class SubnetConfigParser : public BaseNetworkParser {
+public:
+
+    /// @brief constructor
+    ///
+    /// @param family address family: @c AF_INET or @c AF_INET6
+    /// @param check_iface Check if the specified interface exists in
+    /// the system.
+    explicit SubnetConfigParser(uint16_t family, bool check_iface = true);
+
+    /// @brief virtual destructor (does nothing)
+    virtual ~SubnetConfigParser() { }
+
+protected:
+    /// @brief parses a subnet description and returns Subnet{4,6} structure
+    ///
+    /// This method is called from specialized (Subnet4ConfigParser or
+    /// Subnet6ConfigParser) classes.
+    ///
+    /// @param subnet pointer to the content of subnet definition
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @return a pointer to newly created subnet
+    ///
+    /// @throw isc::DhcpConfigError if subnet configuration parsing failed.
+    SubnetPtr parse(isc::data::ConstElementPtr subnet,
+                    bool encapsulate_options);
+
+    /// @brief Instantiates the subnet based on a given IP prefix and prefix
+    /// length.
+    ///
+    /// @param params configuration parameters for that subnet
+    /// @param addr is the IP prefix of the subnet.
+    /// @param len is the prefix length
+    virtual void initSubnet(isc::data::ConstElementPtr params,
+                            isc::asiolink::IOAddress addr, uint8_t len) = 0;
+
+protected:
+
+    /// @brief Create a new subnet using a data from child parsers.
+    ///
+    /// @param data Element map that describes the subnet
+    /// @throw isc::dhcp::DhcpConfigError if subnet configuration parsing
+    /// failed.
+    void createSubnet(isc::data::ConstElementPtr data);
+
+    /// @brief Returns an instance of the @c OptionDataListParser to
+    /// be used in parsing the option-data structure.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for option data.
+    ///
+    /// @return an instance of the @c OptionDataListParser.
+    virtual boost::shared_ptr<OptionDataListParser> createOptionDataListParser() const;
+
+    /// @brief Returns an instance of the @c PoolsListParser to be used
+    /// in parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c PoolsListParser.
+    virtual boost::shared_ptr<PoolsListParser>
+    createPoolsListParser() const = 0;
+
+    /// Storage for pools belonging to this subnet.
+    PoolStoragePtr pools_;
+
+    /// Pointer to the created subnet object.
+    isc::dhcp::SubnetPtr subnet_;
+
+    /// @brief Address family: @c AF_INET or @c AF_INET6
+    uint16_t address_family_;
+
+    /// Pointer to relay information
+    isc::dhcp::Network::RelayInfoPtr relay_info_;
+
+    /// Check if the specified interface exists in the system.
+    bool check_iface_;
+};
+
+/// @anchor Subnet4ConfigParser
+/// @brief This class parses a single IPv4 subnet.
+///
+/// This is the IPv4 derivation of the SubnetConfigParser class and it parses
+/// the whole subnet definition. It creates parsersfor received configuration
+/// parameters as needed.
+class Subnet4ConfigParser : public SubnetConfigParser {
+public:
+    /// @brief Constructor
+    ///
+    /// stores global scope parameters, options, option definitions.
+    ///
+    /// @param check_iface Check if the specified interface exists in
+    /// the system.
+    Subnet4ConfigParser(bool check_iface = true);
+
+    /// @brief Parses a single IPv4 subnet configuration and adds to the
+    /// Configuration Manager.
+    ///
+    /// @param subnet A new subnet being configured.
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @return a pointer to created Subnet4 object
+    Subnet4Ptr parse(data::ConstElementPtr subnet,
+                     bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Instantiates the IPv4 Subnet based on a given IPv4 address
+    /// and prefix length.
+    ///
+    /// @param params Data structure describing a subnet.
+    /// @param addr is IPv4 address of the subnet.
+    /// @param len is the prefix length
+    void initSubnet(data::ConstElementPtr params,
+                    asiolink::IOAddress addr, uint8_t len);
+
+    /// @brief Verifies the host reservation address is in the subnet range
+    ///
+    /// @param subnet pointer to the subnet
+    /// @param host pointer to the host reservation
+    /// @throw DhcpConfigError when the address is not in the subnet range.
+    void validateResv(const Subnet4Ptr& subnet, ConstHostPtr host);
+
+    /// @brief Returns an instance of the @c Pools4ListParser to be used
+    /// in parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c Pools4ListParser.
+    virtual boost::shared_ptr<PoolsListParser>
+    createPoolsListParser() const;
+};
+
+/// @brief this class parses list of DHCP4 subnets
+///
+/// This is a wrapper parser that handles the whole list of Subnet4
+/// definitions. It iterates over all entries and creates Subnet4ConfigParser
+/// for each entry.
+class Subnets4ListConfigParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief constructor
+    ///
+    /// @param check_iface Check if the specified interface exists in
+    /// the system.
+    Subnets4ListConfigParser(bool check_iface = true);
+
+    /// @brief Virtual destructor.
+    virtual ~Subnets4ListConfigParser() {
+    }
+
+    /// @brief parses contents of the list
+    ///
+    /// Iterates over all entries on the list, parses its content
+    /// (by instantiating Subnet6ConfigParser) and adds to specified
+    /// configuration.
+    ///
+    /// @param cfg Pointer to server configuration.
+    /// @param subnets_list pointer to a list of IPv4 subnets
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @return number of subnets created
+    size_t parse(SrvConfigPtr cfg, data::ConstElementPtr subnets_list,
+                 bool encapsulate_options = true);
+
+    /// @brief Parses contents of the subnet4 list.
+    ///
+    /// @param [out] subnets Container where parsed subnets will be stored.
+    /// @param subnets_list pointer to a list of IPv4 subnets
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @return Number of subnets created.
+    size_t parse(Subnet4Collection& subnets,
+                 data::ConstElementPtr subnets_list,
+                 bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Returns an instance of the @c Subnet4ConfigParser to be
+    /// used in parsing the subnets.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the subnets.
+    ///
+    /// @return an instance of the @c Subnet4ConfigParser.
+    virtual boost::shared_ptr<Subnet4ConfigParser> createSubnetConfigParser() const;
+
+    /// Check if the specified interface exists in the system.
+    bool check_iface_;
+};
+
+/// @brief Parser for IPv6 pool definitions.
+///
+/// This is the IPv6 derivation of the PoolParser class and handles pool
+/// definitions, i.e. a list of entries of one of two syntaxes: min-max and
+/// prefix/len for IPv6 pools. Pool6 objects are created and stored in chosen
+/// PoolStorage container.
+///
+/// It is useful for parsing Dhcp6/subnet6[X]/pool parameters.
+class Pool6Parser : public PoolParser {
+protected:
+    /// @brief Creates a Pool6 object given a IPv6 prefix and the prefix length.
+    ///
+    /// @param addr is the IPv6 prefix of the pool.
+    /// @param len is the prefix length.
+    /// @param ptype is the type of IPv6 pool (Pool::PoolType). Note this is
+    /// passed in as an int32_t and cast to PoolType to accommodate a
+    /// polymorphic interface.
+    /// @return returns a PoolPtr to the new Pool4 object.
+    PoolPtr poolMaker (asiolink::IOAddress &addr, uint32_t len, int32_t ptype);
+
+    /// @brief Creates a Pool6 object given starting and ending IPv6 addresses.
+    ///
+    /// @param min is the first IPv6 address in the pool.
+    /// @param max is the last IPv6 address in the pool.
+    /// @param ptype is the type of IPv6 pool (Pool::PoolType). Note this is
+    /// passed in as an int32_t and cast to PoolType to accommodate a
+    /// polymorphic interface.
+    /// @return returns a PoolPtr to the new Pool4 object.
+    PoolPtr poolMaker (asiolink::IOAddress &min, asiolink::IOAddress &max,
+                       int32_t ptype);
+};
+
+/// @brief Specialization of the pool list parser for DHCPv6
+class Pools6ListParser : public PoolsListParser {
+public:
+
+    /// @brief parses the actual structure
+    ///
+    /// This method parses the actual list of pools.
+    ///
+    /// @param pools storage container in which to store the parsed pool.
+    /// @param pools_list a list of pool structures
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @throw isc::dhcp::DhcpConfigError when pool parsing fails
+    void parse(PoolStoragePtr pools, data::ConstElementPtr pools_list,
+               bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Returns an instance of the @c Pool6Parser to be used in
+    /// parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c Pool6Parser.
+    virtual boost::shared_ptr<PoolParser> createPoolConfigParser() const;
+};
+
+/// @brief Parser for IPv6 prefix delegation definitions.
+///
+/// This class handles prefix delegation pool definitions for IPv6 subnets
+/// Pool6 objects are created and stored in the given PoolStorage container.
+///
+/// PdPool definitions currently support three elements: prefix, prefix-len,
+/// and delegated-len, as shown in the example JSON text below:
+///
+/// @code
+///
+/// {
+///     "prefix": "2001:db8:1::",
+///     "prefix-len": 64,
+///     "delegated-len": 128
+/// }
+/// @endcode
+///
+class PdPoolParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief Constructor.
+    ///
+    PdPoolParser();
+
+    /// @brief Virtual destructor.
+    virtual ~PdPoolParser() {
+    }
+
+    /// @brief Builds a prefix delegation pool from the given configuration
+    ///
+    /// This function parses configuration entries and creates an instance
+    /// of a dhcp::Pool6 configured for prefix delegation.
+    ///
+    /// @param pools storage container in which to store the parsed pool.
+    /// @param pd_pool_ pointer to an element that holds configuration entries
+    /// that define a prefix delegation pool.
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    ///
+    /// @throw DhcpConfigError if configuration parsing fails.
+    void parse(PoolStoragePtr pools, data::ConstElementPtr pd_pool_,
+               bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Returns an instance of the @c OptionDataListParser to
+    /// be used in parsing the option-data structure.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for option data.
+    ///
+    /// @return an instance of the @c OptionDataListParser.
+    virtual boost::shared_ptr<OptionDataListParser>
+    createOptionDataListParser() const;
+
+    /// Pointer to the created pool object.
+    isc::dhcp::Pool6Ptr pool_;
+
+    /// @brief User context (optional, may be null)
+    ///
+    /// User context is arbitrary user data, to be used by hooks.
+    isc::data::ConstElementPtr user_context_;
+
+    /// @brief Client class (a client has to belong to to use this pd-pool)
+    ///
+    /// If null, everyone is allowed.
+    isc::data::ConstElementPtr client_class_;
+};
+
+/// @brief Parser for a list of prefix delegation pools.
+///
+/// This parser iterates over a list of prefix delegation pool entries and
+/// creates pool instances for each one. If the parsing is successful, the
+/// collection of pools is committed to the provided storage.
+class PdPoolsListParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief Virtual destructor.
+    virtual ~PdPoolsListParser() {
+    }
+
+    /// @brief Parse configuration entries.
+    ///
+    /// This function parses configuration entries and creates instances
+    /// of prefix delegation pools .
+    ///
+    /// @param pools is the pool storage in which to store the parsed
+    /// @param pd_pool_list pointer to an element that holds entries
+    /// that define a prefix delegation pool.
+    ///
+    /// @throw DhcpConfigError if configuration parsing fails.
+    void parse(PoolStoragePtr pools, data::ConstElementPtr pd_pool_list);
+
+protected:
+
+    /// @brief Returns an instance of the @c PdPoolParser to be used in
+    /// parsing the prefix delegation pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c PdPool6Parser.
+    virtual boost::shared_ptr<PdPoolParser>
+    createPdPoolConfigParser() const;
+};
+
+/// @anchor Subnet6ConfigParser
+/// @brief This class parses a single IPv6 subnet.
+///
+/// This is the IPv6 derivation of the SubnetConfigParser class and it parses
+/// the whole subnet definition. It creates parsersfor received configuration
+/// parameters as needed.
+class Subnet6ConfigParser : public SubnetConfigParser {
+public:
+
+    /// @brief Constructor
+    ///
+    /// stores global scope parameters, options, option definitions.
+    ///
+    /// @param check_iface Check if the specified interface exists in
+    /// the system.
+    Subnet6ConfigParser(bool check_iface = true);
+
+    /// @brief Parses a single IPv6 subnet configuration and adds to the
+    /// Configuration Manager.
+    ///
+    /// @param subnet A new subnet being configured.
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @return a pointer to created Subnet6 object
+    Subnet6Ptr parse(data::ConstElementPtr subnet,
+                     bool encapsulate_options = true);
+
+protected:
+    /// @brief Issues a DHCP6 server specific warning regarding duplicate subnet
+    /// options.
+    ///
+    /// @param code is the numeric option code of the duplicate option
+    /// @param addr is the subnet address
+    /// @todo A means to know the correct logger and perhaps a common
+    /// message would allow this message to be emitted by the base class.
+    virtual void duplicateOptionWarning(uint32_t code,
+                                        asiolink::IOAddress& addr);
+
+    /// @brief Instantiates the IPv6 Subnet based on a given IPv6 address
+    /// and prefix length.
+    ///
+    /// @param params Data structure describing a subnet.
+    /// @param addr is IPv6 prefix of the subnet.
+    /// @param len is the prefix length
+    void initSubnet(isc::data::ConstElementPtr params,
+                    isc::asiolink::IOAddress addr, uint8_t len);
+
+    /// @brief Verifies host reservation addresses are in the subnet range
+    ///
+    /// @param subnet pointer to the subnet
+    /// @param host pointer to the host reservation
+    /// @throw DhcpConfigError when an address is not in the subnet range.
+    void validateResvs(const Subnet6Ptr& subnet, ConstHostPtr host);
+
+    /// @brief Returns an instance of the @c Pools6ListParser to be used
+    /// in parsing the address pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c Pools6ListParser.
+    virtual boost::shared_ptr<PoolsListParser>
+    createPoolsListParser() const;
+
+    /// @brief Returns an instance of the @c PdPools6ListParser to be used
+    /// in parsing the prefix delegation pools.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the pools.
+    ///
+    /// @return an instance of the @c PdPools6ListParser.
+    virtual boost::shared_ptr<PdPoolsListParser>
+    createPdPoolsListParser() const;
+};
+
+
+/// @brief this class parses a list of DHCP6 subnets
+///
+/// This is a wrapper parser that handles the whole list of Subnet6
+/// definitions. It iterates over all entries and creates Subnet6ConfigParser
+/// for each entry.
+class Subnets6ListConfigParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief constructor
+    ///
+    /// @param check_iface Check if the specified interface exists in
+    /// the system.
+    Subnets6ListConfigParser(bool check_iface = true);
+
+    /// @brief Virtual destructor.
+    virtual ~Subnets6ListConfigParser() {
+    }
+
+    /// @brief parses contents of the list
+    ///
+    /// Iterates over all entries on the list, parses its content
+    /// (by instantiating Subnet6ConfigParser) and adds to specified
+    /// configuration.
+    ///
+    /// @param cfg configuration (parsed subnets will be stored here)
+    /// @param subnets_list pointer to a list of IPv6 subnets
+    /// @param encapsulate_options a boolean parameter indicating if the
+    /// parsed options should be encapsulated with suboptions.
+    /// @throw DhcpConfigError if CfgMgr rejects the subnet (e.g. subnet-id is a duplicate)
+    size_t parse(SrvConfigPtr cfg, data::ConstElementPtr subnets_list,
+                 bool encapsulate_options = true);
+
+    /// @brief Parses contents of the subnet6 list.
+    ///
+    /// @param [out] subnets Container where parsed subnets will be stored.
+    /// @param subnets_list pointer to a list of IPv6 subnets
+    /// @return Number of subnets created.
+    size_t parse(Subnet6Collection& subnets,
+                 data::ConstElementPtr subnets_list,
+                 bool encapsulate_options = true);
+
+protected:
+
+    /// @brief Returns an instance of the @c Subnet6ConfigParser to be
+    /// used in parsing the subnets.
+    ///
+    /// This function can be overridden in the child classes to supply
+    /// a custom parser for the subnets.
+    ///
+    /// @return an instance of the @c Subnet6ConfigParser.
+    virtual boost::shared_ptr<Subnet6ConfigParser> createSubnetConfigParser() const;
+
+    /// Check if the specified interface exists in the system.
+    bool check_iface_;
+};
+
+/// @brief Parser for D2ClientConfig
+///
+/// This class parses the configuration element "dhcp-ddns" common to the
+/// config files for both dhcp4 and dhcp6. It creates an instance of a
+/// D2ClientConfig.
+class D2ClientConfigParser : public isc::data::SimpleParser {
+public:
+
+    /// @brief Parses a given dhcp-ddns element into D2ClientConfig.
+    ///
+    /// @param d2_client_cfg is the "dhcp-ddns" configuration to parse
+    ///
+    /// The elements currently supported are (see isc::dhcp::D2ClientConfig
+    /// for details on each):
+    /// -# enable-updates
+    /// -# server-ip
+    /// -# server-port
+    /// -# sender-ip
+    /// -# sender-port
+    /// -# max-queue-size
+    /// -# ncr-protocol
+    /// -# ncr-format
+    ///
+    /// @return returns a pointer to newly created D2ClientConfig.
+    D2ClientConfigPtr parse(isc::data::ConstElementPtr d2_client_cfg);
+
+    /// @brief Defaults for the D2 client configuration.
+    static const isc::data::SimpleDefaults D2_CLIENT_CONFIG_DEFAULTS;
+
+    /// @brief Sets all defaults for D2 client configuration.
+    ///
+    /// This method sets defaults value. It must not be called
+    /// before the short cut disabled updates condition was checked.
+    ///
+    /// @param d2_config d2 client configuration (will be const cast
+    //  to ElementPtr)
+    /// @return number of parameters inserted
+    static size_t setAllDefaults(isc::data::ConstElementPtr d2_config);
+
+private:
+
+    /// @brief Returns a value converted to NameChangeProtocol
+    ///
+    /// Instantiation of getAndConvert() to NameChangeProtocol
+    ///
+    /// @param scope specified parameter will be extracted from this scope
+    /// @param name name of the parameter
+    /// @return a NameChangeProtocol value
+    dhcp_ddns::NameChangeProtocol
+    getProtocol(isc::data::ConstElementPtr scope, const std::string& name);
+
+    /// @brief Returns a value converted to NameChangeFormat
+    ///
+    /// Instantiation of getAndConvert() to NameChangeFormat
+    ///
+    /// @param scope specified parameter will be extracted from this scope
+    /// @param name name of the parameter
+    /// @return a NameChangeFormat value
+    dhcp_ddns::NameChangeFormat
+    getFormat(isc::data::ConstElementPtr scope, const std::string& name);
+
+    /// @brief Returns a value converted to ReplaceClientNameMode
+    ///
+    /// Instantiation of getAndConvert() to ReplaceClientNameMode
+    ///
+    /// @param scope specified parameter will be extracted from this scope
+    /// @param name name of the parameter
+    /// @return a NameChangeFormat value
+    D2ClientConfig::ReplaceClientNameMode
+    getMode(isc::data::ConstElementPtr scope, const std::string& name);
+};
+
+} // end of isc::dhcp namespace
+} // end of isc namespace
+
+#endif // DHCP_PARSERS_H