Current File : //backups/router/usr/local/include/kea/dhcp/option6_pdexclude.h
// Copyright (C) 2016-2022 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 OPTION6_PDEXCLUDE_H
#define OPTION6_PDEXCLUDE_H
#include <asiolink/io_address.h>
#include <dhcp/option.h>
#include <boost/shared_ptr.hpp>
#include <stdint.h>
namespace isc {
namespace dhcp {
/// @brief DHCPv6 option class representing Prefix Exclude Option (RFC 6603).
///
/// This class represents DHCPv6 Prefix Exclude option (67). This option is
/// carried in the IA Prefix option and it conveys a single prefix which is
/// used by the delegating router to communicate with a requesting router on
/// the requesting router's uplink. This prefix is not used on the
/// requesting router's downlinks (is excluded from other delegated prefixes).
class Option6PDExclude: public Option {
public:
/// @brief Constructor.
///
/// @param delegated_prefix Delegated prefix.
/// @param delegated_prefix_length Delegated prefix length.
/// @param excluded_prefix Excluded prefix.
/// @param excluded_prefix_length Excluded prefix length.
///
/// @throw BadValue if prefixes are invalid, if excluded prefix length
/// is not greater than delegated prefix length or if common parts of
/// prefixes does not match.
Option6PDExclude(const isc::asiolink::IOAddress& delegated_prefix,
const uint8_t delegated_prefix_length,
const isc::asiolink::IOAddress& excluded_prefix,
const uint8_t excluded_prefix_length);
/// @brief Constructor, creates option instance from part of the buffer.
///
/// This constructor is mostly used to parse Prefix Exclude options in the
/// received messages.
///
/// @param begin Lower bound of the buffer to create option from.
/// @param end Upper bound of the buffer to create option from.
Option6PDExclude(OptionBufferConstIter begin, OptionBufferConstIter end);
/// @brief Copies this option and returns a pointer to the copy.
virtual OptionPtr clone() const;
/// @brief Writes option in wire-format to a buffer.
///
/// Writes option in wire-format to buffer, returns pointer to first unused
/// byte after stored option (that is useful for writing options one after
/// another).
///
/// The format of the option includes excluded prefix length specified as
/// a number of bits. It also includes IPv6 subnet ID field which is
/// computed from the delegated and excluded prefixes, according to the
/// section 4.2 of RFC 6603.
///
/// @param [out] buf Pointer to a buffer.
/// @param check if set to false, allows options larger than 255 for v4
virtual void pack(isc::util::OutputBuffer& buf, bool check = true) const;
/// @brief Parses received buffer.
///
/// @param begin iterator to first byte of option data
/// @param end iterator to end of option data (first byte after option end)
virtual void unpack(OptionBufferConstIter begin, OptionBufferConstIter end);
/// @brief Returns length of the complete option (data length + DHCPv6
/// option header)
///
/// @return length of the option
virtual uint16_t len() const;
/// @brief Returns Prefix Exclude option in textual format.
///
/// @param indent Number of spaces to be inserted before the text.
virtual std::string toText(int indent = 0) const;
/// @brief Returns excluded prefix.
///
/// Assembles excluded prefix from a delegated prefix and IPv6 subnet id
/// specified as in RFC6603, section 4.2.
///
/// @param delegated_prefix Delegated prefix for which excluded prefix will
/// be returned.
/// @param delegated_prefix_length Delegated prefix length.
asiolink::IOAddress
getExcludedPrefix(const asiolink::IOAddress& delegated_prefix,
const uint8_t delegated_prefix_length) const;
/// @brief Returns excluded prefix length.
uint8_t getExcludedPrefixLength() const {
return (excluded_prefix_length_);
}
/// @brief Returns an excluded prefix in a binary format.
const std::vector<uint8_t>& getExcludedPrefixSubnetID() const {
return (subnet_id_);
}
private:
/// @brief Returns IPv6 subnet ID length in octets.
///
/// The IPv6 subnet ID length is between 1 and 16 octets.
uint8_t getSubnetIDLength(const uint8_t delegated_prefix_length,
const uint8_t excluded_prefix_length) const;
/// @brief Holds excluded prefix length.
uint8_t excluded_prefix_length_;
/// @brief Subnet identifier as described in RFC6603, section 4.2.
std::vector<uint8_t> subnet_id_;
};
/// @brief Pointer to the @ref Option6PDExclude object.
typedef boost::shared_ptr<Option6PDExclude> Option6PDExcludePtr;
} // isc::dhcp namespace
} // isc namespace
#endif // OPTION6_PDEXCLUDE_H
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