#pragma once

#include "Layer.h"

#include "TLVData.h"

#include "IpAddress.h"

#include "MacAddress.h"

#include <string.h>

/// @file

/// @namespace pcpp

/// @brief The main namespace for the PcapPlusPlus lib

namespace pcpp

{

  /// @struct dhcp_header

  /// Represents a DHCP protocol header

#pragma pack(push, 1)

  struct dhcp_header

  {

    /// BootP opcode

    uint8_t opCode;

    /// Hardware type, set to 1 (Ethernet) by default

    uint8_t hardwareType;

    /// Hardware address length, set to 6 (MAC address length) by default

    uint8_t hardwareAddressLength;

    /// Hop count

    uint8_t hops;

    /// DHCP/BootP transaction ID

    uint32_t transactionID;

    /// The elapsed time, in seconds since the client sent its first BOOTREQUEST message

    uint16_t secondsElapsed;

    /// BootP flags

    uint16_t flags;

    /// Client IPv4 address

    uint32_t clientIpAddress;

    /// Your IPv4 address

    uint32_t yourIpAddress;

    /// Server IPv4 address

    uint32_t serverIpAddress;

    /// Gateway IPv4 address

    uint32_t gatewayIpAddress;

    /// Client hardware address, by default contains the MAC address (only 6 first bytes are used)

    uint8_t clientHardwareAddress[16];

    /// BootP server name

    uint8_t serverName[64];

    /// BootP boot file name

    uint8_t bootFilename[128];

    /// DHCP magic number (set to the default value of 0x63538263)

    uint32_t magicNumber;

  };

#pragma pack(pop)

  static_assert(sizeof(dhcp_header) == 240, "dhcp_header size is not 240 bytes");

  /// BootP opcodes

  enum BootpOpCodes

  {

    /// BootP request

    DHCP_BOOTREQUEST = 1,

    /// BootP reply

    DHCP_BOOTREPLY = 2

  };

  /// DHCP message types

  enum DhcpMessageType

  {

    /// Unknown message type

    DHCP_UNKNOWN_MSG_TYPE = 0,

    /// Discover message type

    DHCP_DISCOVER = 1,

    /// Offer message type

    DHCP_OFFER = 2,

    /// Request message type

    DHCP_REQUEST = 3,

    /// Decline message type

    DHCP_DECLINE = 4,

    /// Acknowledge message type

    DHCP_ACK = 5,

    /// Non-acknowledge message type

    DHCP_NAK = 6,

    /// Release message type

    DHCP_RELEASE = 7,

    /// Inform message type

    DHCP_INFORM = 8

  };

  /// DHCP option types.

  enum DhcpOptionTypes

  {

    /// Unknown option type

    DHCPOPT_UNKNOWN = -1,

    /// Pad

    DHCPOPT_PAD = 0,

    /// Subnet Mask Value

    DHCPOPT_SUBNET_MASK = 1,

    /// Time Offset in Seconds from UTC

    DHCPOPT_TIME_OFFSET = 2,

    /// N/4 Router addresses

    DHCPOPT_ROUTERS = 3,

    /// N/4 Timeserver addresses

    DHCPOPT_TIME_SERVERS = 4,

    /// N/4 IEN-116 Server addresses

    DHCPOPT_NAME_SERVERS = 5,

    /// N/4 DNS Server addresses

    DHCPOPT_DOMAIN_NAME_SERVERS = 6,

    /// N/4 Logging Server addresses

    DHCPOPT_LOG_SERVERS = 7,

    /// N/4 Quotes Server addresses

    DHCPOPT_QUOTES_SERVERS = 8,

    /// N/4 Quotes Server addresses

    DHCPOPT_LPR_SERVERS = 9,

    /// N/4 Quotes Server addresses

    DHCPOPT_IMPRESS_SERVERS = 10,

    /// N/4 RLP Server addresses

    DHCPOPT_RESOURCE_LOCATION_SERVERS = 11,

    /// Hostname string

    DHCPOPT_HOST_NAME = 12,

    /// Size of boot file in 512 byte chunks

    DHCPOPT_BOOT_SIZE = 13,

    /// Client to dump and name the file to dump it to

    DHCPOPT_MERIT_DUMP = 14,

    /// The DNS domain name of the client

    DHCPOPT_DOMAIN_NAME = 15,

    /// Swap Server address

    DHCPOPT_SWAP_SERVER = 16,

    /// Path name for root disk

    DHCPOPT_ROOT_PATH = 17,

    /// Path name for more BOOTP info

    DHCPOPT_EXTENSIONS_PATH = 18,

    /// Enable/Disable IP Forwarding

    DHCPOPT_IP_FORWARDING = 19,

    /// Enable/Disable Source Routing

    DHCPOPT_NON_LOCAL_SOURCE_ROUTING = 20,

    /// Routing Policy Filters

    DHCPOPT_POLICY_FILTER = 21,

    /// Max Datagram Reassembly Size

    DHCPOPT_MAX_DGRAM_REASSEMBLY = 22,

    /// Default IP Time to Live

    DEFAULT_IP_TTL = 23,

    /// Path MTU Aging Timeout

    DHCPOPT_PATH_MTU_AGING_TIMEOUT = 24,

    /// Path MTU Plateau Table

    PATH_MTU_PLATEAU_TABLE = 25,

    /// Interface MTU Size

    DHCPOPT_INTERFACE_MTU = 26,

    /// All Subnets are Local

    DHCPOPT_ALL_SUBNETS_LOCAL = 27,

    /// Broadcast Address

    DHCPOPT_BROADCAST_ADDRESS = 28,

    /// Perform Mask Discovery

    DHCPOPT_PERFORM_MASK_DISCOVERY = 29,

    /// Provide Mask to Others

    DHCPOPT_MASK_SUPPLIER = 30,

    /// Perform Router Discovery

    DHCPOPT_ROUTER_DISCOVERY = 31,

    /// Router Solicitation Address

    DHCPOPT_ROUTER_SOLICITATION_ADDRESS = 32,

    /// Static Routing Table

    DHCPOPT_STATIC_ROUTES = 33,

    /// Trailer Encapsulation

    DHCPOPT_TRAILER_ENCAPSULATION = 34,

    /// ARP Cache Timeout

    DHCPOPT_ARP_CACHE_TIMEOUT = 35,

    /// IEEE802.3 Encapsulation

    DHCPOPT_IEEE802_3_ENCAPSULATION = 36,

    /// Default TCP Time to Live

    DHCPOPT_DEFAULT_TCP_TTL = 37,

    /// TCP Keepalive Interval

    DHCPOPT_TCP_KEEPALIVE_INTERVAL = 38,

    /// TCP Keepalive Garbage

    DHCPOPT_TCP_KEEPALIVE_GARBAGE = 39,

    /// NIS Domain Name

    DHCPOPT_NIS_DOMAIN = 40,

    /// NIS Server Addresses

    DHCPOPT_NIS_SERVERS = 41,

    /// NTP Server Addresses

    DHCPOPT_NTP_SERVERS = 42,

    /// Vendor Specific Information

    DHCPOPT_VENDOR_ENCAPSULATED_OPTIONS = 43,

    /// NETBIOS Name Servers

    DHCPOPT_NETBIOS_NAME_SERVERS = 44,

    /// NETBIOS Datagram Distribution

    DHCPOPT_NETBIOS_DD_SERVER = 45,

    /// NETBIOS Node Type

    DHCPOPT_NETBIOS_NODE_TYPE = 46,

    /// NETBIOS Scope

    DHCPOPT_NETBIOS_SCOPE = 47,

    /// X Window Font Server

    DHCPOPT_FONT_SERVERS = 48,

    /// X Window Display Manager

    DHCPOPT_X_DISPLAY_MANAGER = 49,

    /// Requested IP Address

    DHCPOPT_DHCP_REQUESTED_ADDRESS = 50,

    /// IP Address Lease Time

    DHCPOPT_DHCP_LEASE_TIME = 51,

    /// Overload "sname" or "file"

    DHCPOPT_DHCP_OPTION_OVERLOAD = 52,

    /// DHCP Message Type

    DHCPOPT_DHCP_MESSAGE_TYPE = 53,

    /// DHCP Server Identification

    DHCPOPT_DHCP_SERVER_IDENTIFIER = 54,

    /// Parameter Request List

    DHCPOPT_DHCP_PARAMETER_REQUEST_LIST = 55,

    /// DHCP Error Message

    DHCPOPT_DHCP_MESSAGE = 56,

    /// DHCP Maximum Message Size

    DHCPOPT_DHCP_MAX_MESSAGE_SIZE = 57,

    /// DHCP Renewal (T1) Time

    DHCPOPT_DHCP_RENEWAL_TIME = 58,

    /// DHCP Rebinding (T2) Time

    DHCPOPT_DHCP_REBINDING_TIME = 59,

    /// Class Identifier

    DHCPOPT_VENDOR_CLASS_IDENTIFIER = 60,

    /// Class Identifier

    DHCPOPT_DHCP_CLIENT_IDENTIFIER = 61,

    /// NetWare/IP Domain Name

    DHCPOPT_NWIP_DOMAIN_NAME = 62,

    /// NetWare/IP sub Options

    DHCPOPT_NWIP_SUBOPTIONS = 63,

    /// NIS+ v3 Client Domain Name

    DHCPOPT_NIS_DOMAIN_NAME = 64,

    /// NIS+ v3 Server Addresses

    DHCPOPT_NIS_SERVER_ADDRESS = 65,

    /// TFTP Server Name

    DHCPOPT_TFTP_SERVER_NAME = 66,

    /// Boot File Name

    DHCPOPT_BOOTFILE_NAME = 67,

    /// Home Agent Addresses

    DHCPOPT_HOME_AGENT_ADDRESS = 68,

    /// Simple Mail Server (SMTP) Addresses

    DHCPOPT_SMTP_SERVER = 69,

    /// Post Office (POP3) Server Addresses

    DHCPOPT_POP3_SERVER = 70,

    /// Network News (NNTP) Server Addresses

    DHCPOPT_NNTP_SERVER = 71,

    /// WWW Server Addresses

    DHCPOPT_WWW_SERVER = 72,

    /// Finger Server Addresses

    DHCPOPT_FINGER_SERVER = 73,

    /// Chat (IRC) Server Addresses

    DHCPOPT_IRC_SERVER = 74,

    /// StreetTalk Server Addresses

    DHCPOPT_STREETTALK_SERVER = 75,

    /// ST Directory Assist. Addresses

    DHCPOPT_STDA_SERVER = 76,

    /// User Class Information

    DHCPOPT_USER_CLASS = 77,

    /// Directory Agent Information

    DHCPOPT_DIRECTORY_AGENT = 78,

    /// Service Location Agent Scope

    DHCPOPT_SERVICE_SCOPE = 79,

    /// Rapid Commit

    DHCPOPT_RAPID_COMMIT = 80,

    /// Fully Qualified Domain Name

    DHCPOPT_FQDN = 81,

    /// Relay Agent Information

    DHCPOPT_DHCP_AGENT_OPTIONS = 82,

    /// Internet Storage Name Service

    DHCPOPT_ISNS = 83,

    /// Novell Directory Services

    DHCPOPT_NDS_SERVERS = 85,

    /// Novell Directory Services

    DHCPOPT_NDS_TREE_NAME = 86,

    /// Novell Directory Services

    DHCPOPT_NDS_CONTEXT = 87,

    /// BCMCS Controller Domain Name list

    DHCPOPT_BCMCS_CONTROLLER_DOMAIN_NAME_LIST = 88,

    /// BCMCS Controller IPv4 address option

    DHCPOPT_BCMCS_CONTROLLER_IPV4_ADDRESS = 89,

    /// Authentication

    DHCPOPT_AUTHENTICATION = 90,

    /// Client Last Transaction Time

    DHCPOPT_CLIENT_LAST_TXN_TIME = 91,

    /// Associated IP

    DHCPOPT_ASSOCIATED_IP = 92,

    /// Client System Architecture

    DHCPOPT_CLIENT_SYSTEM = 93,

    /// Client Network Device Interface

    DHCPOPT_CLIENT_NDI = 94,

    /// Lightweight Directory Access Protocol [

    DHCPOPT_LDAP = 95,

    /// UUID/GUID-based Client Identifier

    DHCPOPT_UUID_GUID = 97,

    /// Open Group's User Authentication

    DHCPOPT_USER_AUTH = 98,

    /// GEOCONF_CIVIC

    DHCPOPT_GEOCONF_CIVIC = 99,

    /// IEEE 1003.1 TZ String

    DHCPOPT_PCODE = 100,

    /// Reference to the TZ Database

    DHCPOPT_TCODE = 101,

    /// NetInfo Parent Server Address

    DHCPOPT_NETINFO_ADDRESS = 112,

    /// NetInfo Parent Server Tag

    DHCPOPT_NETINFO_TAG = 113,

    /// URL

    DHCPOPT_URL = 114,

    /// DHCP Auto-Configuration

    DHCPOPT_AUTO_CONFIG = 116,

    /// Name Service Search

    DHCPOPT_NAME_SERVICE_SEARCH = 117,

    /// Subnet Selection Option

    DHCPOPT_SUBNET_SELECTION = 118,

    /// DNS Domain Search List

    DHCPOPT_DOMAIN_SEARCH = 119,

    /// SIP Servers DHCP Option

    DHCPOPT_SIP_SERVERS = 120,

    /// Classless Static Route Option

    DHCPOPT_CLASSLESS_STATIC_ROUTE = 121,

    /// CableLabs Client Configuration

    DHCPOPT_CCC = 122,

    /// GeoConf Option

    DHCPOPT_GEOCONF = 123,

    /// Vendor-Identifying Vendor Class

    DHCPOPT_V_I_VENDOR_CLASS = 124,

    /// Vendor-Identifying Vendor-Specific Information

    DHCPOPT_V_I_VENDOR_OPTS = 125,

    /// OPTION_PANA_AGENT

    DHCPOPT_OPTION_PANA_AGENT = 136,

    /// OPTION_V4_LOST

    DHCPOPT_OPTION_V4_LOST = 137,

    /// CAPWAP Access Controller addresses

    DHCPOPT_OPTION_CAPWAP_AC_V4 = 138,

    /// A Series Of Suboptions

    DHCPOPT_OPTION_IPV4_ADDRESS_MOS = 139,

    /// A Series Of Suboptions

    DHCPOPT_OPTION_IPV4_FQDN_MOS = 140,

    /// List of domain names to search for SIP User Agent Configuration

    DHCPOPT_SIP_UA_CONFIG = 141,

    /// ANDSF IPv4 Address Option for DHCPv4

    DHCPOPT_OPTION_IPV4_ADDRESS_ANDSF = 142,

    /// Geospatial Location with Uncertainty [RF

    DHCPOPT_GEOLOC = 144,

    /// Forcerenew Nonce Capable

    DHCPOPT_FORCERENEW_NONCE_CAPABLE = 145,

    /// Information for selecting RDNSS

    DHCPOPT_RDNSS_SELECTION = 146,

    /// Status code and optional N byte text message describing status

    DHCPOPT_STATUS_CODE = 151,

    /// Absolute time (seconds since Jan 1, 1970) message was sent

    DHCPOPT_BASE_TIME = 152,

    /// Number of seconds in the past when client entered current state

    DHCPOPT_START_TIME_OF_STATE = 153,

    /// Absolute time (seconds since Jan 1, 1970) for beginning of query

    DHCPOPT_QUERY_START_TIME = 154,

    /// Absolute time (seconds since Jan 1, 1970) for end of query

    DHCPOPT_QUERY_END_TIME = 155,

    /// State of IP address

    DHCPOPT_DHCP_STATE = 156,

    /// Indicates information came from local or remote server

    DHCPOPT_DATA_SOURCE = 157,

    /// Includes one or multiple lists of PCP server IP addresses; each list is treated as a separate PCP server

    DHCPOPT_OPTION_V4_PCP_SERVER = 158,

    /// This option is used to configure a set of ports bound to a shared IPv4 address

    DHCPOPT_OPTION_V4_PORTPARAMS = 159,

    /// DHCP Captive-Portal

    DHCPOPT_CAPTIVE_PORTAL = 160,

    /// Manufacturer Usage Descriptions

    DHCPOPT_OPTION_MUD_URL_V4 = 161,

    /// Etherboot

    DHCPOPT_ETHERBOOT = 175,

    /// IP Telephone

    DHCPOPT_IP_TELEPHONE = 176,

    /// Magic string = F1:00:74:7E

    DHCPOPT_PXELINUX_MAGIC = 208,

    /// Configuration file

    DHCPOPT_CONFIGURATION_FILE = 209,

    /// Path Prefix Option

    DHCPOPT_PATH_PREFIX = 210,

    /// Reboot Time

    DHCPOPT_REBOOT_TIME = 211,

    /// OPTION_6RD with N/4 6rd BR addresses

    DHCPOPT_OPTION_6RD = 212,

    /// Access Network Domain Name

    DHCPOPT_OPTION_V4_ACCESS_DOMAIN = 213,

    /// Subnet Allocation Option

    DHCPOPT_SUBNET_ALLOCATION = 220,

    /// Virtual Subnet Selection (VSS) Option

    DHCPOPT_VIRTUAL_SUBNET_SELECTION = 221,

    /// End (last option)

    DHCPOPT_END = 255

  };

  /// @class DhcpOption

  /// A wrapper class for DHCP options. This class does not create or modify DHCP option records, but rather

  /// serves as a wrapper and provides useful methods for setting and retrieving data to/from them

  class DhcpOption : public TLVRecord<uint8_t, uint8_t>

  {

  public:

    /// A c'tor for this class that gets a pointer to the option raw data (byte array)

    /// @param[in] optionRawData A pointer to the option raw data

    explicit DhcpOption(uint8_t* optionRawData) : TLVRecord(optionRawData)

    {}

    /// A d'tor for this class, currently does nothing

    ~DhcpOption() override = default;

    /// Retrieve DHCP option data as IPv4 address. Relevant only if option value is indeed an IPv4 address

    /// @return DHCP option data as IPv4 address

    IPv4Address getValueAsIpAddr() const

    {

      return getValueAs<uint32_t>();

    }

    /// Set DHCP option data as IPv4 address. This method copies the 4 bytes of the IP address to the option value

    /// @param[in] addr The IPv4 address to set

    /// @param[in] valueOffset An optional parameter that specifies where to start set the option data (default set

    /// to 0). For example: if option data is 20 bytes long and you want to set the IP address in the 4 last bytes

    /// then use this method like this: setValueIpAddr(your_addr, 16)

    void setValueIpAddr(const IPv4Address& addr, int valueOffset = 0)

    {

      setValue<uint32_t>(addr.toInt(), valueOffset);

    }

    /// Retrieve DHCP option data as string. Relevant only if option value is indeed a string

    /// @param[in] valueOffset An optional parameter that specifies where to start copy the DHCP option data. For

    /// example: when retrieving Client FQDN option, you may ignore the flags and RCODE fields using this method

    /// like this: getValueAsString(3). The default is 0 - start copying from the beginning of option data

    /// @return DHCP option data as string

    std::string getValueAsString(int valueOffset = 0) const

    {

      if (m_Data == nullptr || m_Data->recordLen - valueOffset < 1)

        return "";

      return std::string(reinterpret_cast<const char*>(m_Data->recordValue) + valueOffset,

                         static_cast<int>(m_Data->recordLen) - valueOffset);

    }

    /// Set DHCP option data as string. This method copies the string to the option value. If the string is longer

    /// than option length the string is trimmed so it will fit the option length

    /// @param[in] stringValue The string to set

    /// @param[in] valueOffset An optional parameter that specifies where to start set the option data (default set

    /// to 0). For example: if option data is 20 bytes long and you want to set a 6 char-long string in the 6 last

    /// bytes then use this method like this: setValueString("string", 14)

    void setValueString(const std::string& stringValue, int valueOffset = 0)

    {

      // calculate the maximum length of the destination buffer

      size_t len = static_cast<size_t>(m_Data->recordLen) - static_cast<size_t>(valueOffset);

      // use the length of input string if a buffer is large enough for whole string

      if (stringValue.length() < len)

        len = stringValue.length();

      memcpy(m_Data->recordValue + valueOffset, stringValue.data(), len);

    }

    /// Check if a pointer can be assigned to the TLV record data

    /// @param[in] recordRawData A pointer to the TLV record raw data

    /// @param[in] tlvDataLen The size of the TLV record raw data

    /// @return True if data is valid and can be assigned

    static bool canAssign(const uint8_t* recordRawData, size_t tlvDataLen)

    {

      auto data = reinterpret_cast<TLVRawData const*>(recordRawData);

      if (data == nullptr)

        return false;

      if (tlvDataLen < sizeof(TLVRawData::recordType))

        return false;

      if (data->recordType == static_cast<uint8_t>(DHCPOPT_END) ||

          data->recordType == static_cast<uint8_t>(DHCPOPT_PAD))

        return true;

      return TLVRecord<uint8_t, uint8_t>::canAssign(recordRawData, tlvDataLen);

    }

    // implement abstract methods

    size_t getTotalSize() const override

    {

      if (m_Data == nullptr)

        return 0;

      if (m_Data->recordType == static_cast<uint8_t>(DHCPOPT_END) ||

          m_Data->recordType == static_cast<uint8_t>(DHCPOPT_PAD))

        return sizeof(uint8_t);

      return sizeof(uint8_t) * 2 + static_cast<size_t>(m_Data->recordLen);

    }

    size_t getDataSize() const override

    {

      if (m_Data == nullptr)

        return 0;

      if (m_Data->recordType == static_cast<uint8_t>(DHCPOPT_END) ||

          m_Data->recordType == static_cast<uint8_t>(DHCPOPT_PAD))

        return 0;

      return m_Data->recordLen;

    }

  };

  /// @class DhcpOptionBuilder

  /// A class for building DHCP options. This builder receives the option parameters in its c'tor,

  /// builds the DHCP option raw buffer and provides a build() method to get a DhcpOption object out of it

  class DhcpOptionBuilder : public TLVRecordBuilder

  {

  public:

    /// A c'tor for building DHCP options which their value is a byte array. The DhcpOption object can later

    /// be retrieved by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue A buffer containing the option value. This buffer is read-only and isn't modified in

    /// any way

    /// @param[in] optionValueLen DHCP option value length in bytes

    DhcpOptionBuilder(DhcpOptionTypes optionType, const uint8_t* optionValue, uint8_t optionValueLen)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue, optionValueLen)

    {}

    /// A c'tor for building DHCP options which have a 1-byte value. The DhcpOption object can later be retrieved

    /// by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue A 1-byte option value

    DhcpOptionBuilder(DhcpOptionTypes optionType, uint8_t optionValue)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue)

    {}

    /// A c'tor for building DHCP options which have a 2-byte value. The DhcpOption object can later be retrieved

    /// by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue A 2-byte option value

    DhcpOptionBuilder(DhcpOptionTypes optionType, uint16_t optionValue)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue)

    {}

    /// A c'tor for building DHCP options which have a 4-byte value. The DhcpOption object can later be retrieved

    /// by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue A 4-byte option value

    DhcpOptionBuilder(DhcpOptionTypes optionType, uint32_t optionValue)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue)

    {}

    /// A c'tor for building DHCP options which have an IPv4Address value. The DhcpOption object can later be

    /// retrieved by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue The IPv4 address option value

    DhcpOptionBuilder(DhcpOptionTypes optionType, const IPv4Address& optionValue)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue)

    {}

    /// A c'tor for building DHCP options which have a string value. The DhcpOption object can later be retrieved

    /// by calling build()

    /// @param[in] optionType DHCP option type

    /// @param[in] optionValue The string option value

    DhcpOptionBuilder(DhcpOptionTypes optionType, const std::string& optionValue)

        : TLVRecordBuilder(static_cast<uint8_t>(optionType), optionValue)

    {}

    /// A copy c'tor which copies all the data from another instance of DhcpOptionBuilder

    /// @param[in] other The instance to copy from

    DhcpOptionBuilder(const DhcpOptionBuilder& other) : TLVRecordBuilder(other)

    {}

    /// Assignment operator that copies all data from another instance of DhcpOptionBuilder

    /// @param[in] other The instance to assign from

    /// @return A reference to the assignee

    DhcpOptionBuilder& operator=(const DhcpOptionBuilder& other)

    {

      TLVRecordBuilder::operator=(other);

      return *this;

    }

    /// Build the DhcpOption object out of the parameters defined in the c'tor

    /// @return The DhcpOption object

    DhcpOption build() const;

  };

  /// @class DhcpLayer

  /// Represents a DHCP (Dynamic Host Configuration Protocol) protocol layer

  class DhcpLayer : public Layer

  {

  public:

    /// A constructor that creates the layer from an existing packet raw data

    /// @param[in] data A pointer to the raw data

    /// @param[in] dataLen Size of the data in bytes

    /// @param[in] prevLayer A pointer to the previous layer

    /// @param[in] packet A pointer to the Packet instance where layer will be stored in

    DhcpLayer(uint8_t* data, size_t dataLen, Layer* prevLayer, Packet* packet);

    /// A constructor that creates the layer from scratch. Adds a ::DHCPOPT_DHCP_MESSAGE_TYPE and a ::DHCPOPT_END

    /// options

    /// @param[in] msgType A DHCP message type to be set

    /// @param[in] clientMacAddr A client MAC address to set in dhcp_header#clientHardwareAddress field

    DhcpLayer(DhcpMessageType msgType, const MacAddress& clientMacAddr);

    /// A constructor that creates the layer from scratch with clean data

    DhcpLayer();

    /// A destructor for this layer

    ~DhcpLayer() override = default;

    /// Get a pointer to the DHCP header. Notice this points directly to the data, so every change will change the

    /// actual packet data

    /// @return A pointer to the @ref dhcp_header

    dhcp_header* getDhcpHeader() const

    {

      return reinterpret_cast<dhcp_header*>(m_Data);

    }

    /// @return The BootP opcode of this message

    BootpOpCodes getOpCode() const

    {

      return static_cast<BootpOpCodes>(getDhcpHeader()->opCode);

    }

    /// @return The client IPv4 address (as extracted from dhcp_header#clientIpAddress converted to IPv4Address

    /// object)

    IPv4Address getClientIpAddress() const

    {

      return getDhcpHeader()->clientIpAddress;

    }

    /// Set the client IPv4 address in dhcp_header#clientIpAddress

    /// @param[in] addr The IPv4 address to set

    void setClientIpAddress(const IPv4Address& addr)

    {

      getDhcpHeader()->clientIpAddress = addr.toInt();

    }

    /// @return The server IPv4 address (as extracted from dhcp_header#serverIpAddress converted to IPv4Address

    /// object)

    IPv4Address getServerIpAddress() const

    {

      return getDhcpHeader()->serverIpAddress;

    }

    /// Set the server IPv4 address in dhcp_header#serverIpAddress

    /// @param[in] addr The IPv4 address to set

    void setServerIpAddress(const IPv4Address& addr)

    {

      getDhcpHeader()->serverIpAddress = addr.toInt();

    }

    /// @return Your IPv4 address (as extracted from dhcp_header#yourIpAddress converted to IPv4Address object)

    IPv4Address getYourIpAddress() const

    {

      return getDhcpHeader()->yourIpAddress;

    }

    /// Set your IPv4 address in dhcp_header#yourIpAddress

    /// @param[in] addr The IPv4 address to set

    void setYourIpAddress(const IPv4Address& addr)

    {

      getDhcpHeader()->yourIpAddress = addr.toInt();

    }

    /// @return Gateway IPv4 address (as extracted from dhcp_header#gatewayIpAddress converted to IPv4Address

    /// object)

    IPv4Address getGatewayIpAddress() const

    {

      return getDhcpHeader()->gatewayIpAddress;

    }

    /// Set the gateway IPv4 address in dhcp_header#gatewayIpAddress

    /// @param[in] addr The IPv4 address to set

    void setGatewayIpAddress(const IPv4Address& addr)

    {

      getDhcpHeader()->gatewayIpAddress = addr.toInt();

    }

    /// @return The client MAC address as extracted from dhcp_header#clientHardwareAddress, assuming

    /// dhcp_header#hardwareType is 1 (Ethernet) and dhcp_header#hardwareAddressLength is 6 (MAC address length).

    /// Otherwise returns MacAddress#Zero

    MacAddress getClientHardwareAddress() const;

    /// Set a MAC address into the first 6 bytes of dhcp_header#clientHardwareAddress. This method also sets

    /// dhcp_header#hardwareType to 1 (Ethernet) and dhcp_header#hardwareAddressLength to 6 (MAC address length)

    /// @param[in] addr The MAC address to set

    void setClientHardwareAddress(const MacAddress& addr);

    /// @return DHCP message type as extracted from ::DHCPOPT_DHCP_MESSAGE_TYPE option. If this option doesn't exist

    /// the value of

    /// ::DHCP_UNKNOWN_MSG_TYPE is returned

    DhcpMessageType getMessageType() const;

    /// Set DHCP message type. This method searches for existing ::DHCPOPT_DHCP_MESSAGE_TYPE option. If found, it

    /// sets the requested message type as its value. If not, it creates a ::DHCPOPT_DHCP_MESSAGE_TYPE option and

    /// sets the requested message type as its value

    /// @param[in] msgType Message type to set

    /// @return True if message type was set successfully or false if msgType is ::DHCP_UNKNOWN_MSG_TYPE or if

    /// failed to add

    /// ::DHCPOPT_DHCP_MESSAGE_TYPE option

    bool setMessageType(DhcpMessageType msgType);

    /// @return The first DHCP option in the packet. If there are no DHCP options the returned value will contain

    /// a logical null (DhcpOption#isNull() == true)

    DhcpOption getFirstOptionData() const;

    /// Get the DHCP option that comes after a given option. If the given option was the last one, the

    /// returned value will contain a logical null (DhcpOption#isNull() == true)

    /// @param[in] dhcpOption A given DHCP option

    /// @return A DhcpOption object containing the option data that comes next, or logical null if the given DHCP

    /// option: (1) was the last one; (2) contains a logical null or (3) doesn't belong to this packet

    DhcpOption getNextOptionData(DhcpOption dhcpOption) const;

    /// Get a DHCP option by type

    /// @param[in] option DHCP option type

    /// @return A DhcpOption object containing the first DHCP option data that matches this type, or logical null

    /// (DhcpOption#isNull() == true) if no such option found

    DhcpOption getOptionData(DhcpOptionTypes option) const;

    /// @return The number of DHCP options in this layer

    size_t getOptionsCount() const;

    /// Add a new DHCP option at the end of the layer

    /// @param[in] optionBuilder A DhcpOptionBuilder object that contains the requested DHCP option data to add

    /// @return A DhcpOption object containing the newly added DHCP option data or logical null

    /// (DhcpOption#isNull() == true) if addition failed

    DhcpOption addOption(const DhcpOptionBuilder& optionBuilder);

    /// Add a new DHCP option after an existing one

    /// @param[in] optionBuilder A DhcpOptionBuilder object that contains the requested DHCP option data to add

    /// @param[in] prevOption The DHCP option type which the newly added option will come after

    /// @return A DhcpOption object containing the newly added DHCP option data or logical null

    /// (DhcpOption#isNull() == true) if addition failed

    DhcpOption addOptionAfter(const DhcpOptionBuilder& optionBuilder, DhcpOptionTypes prevOption);

    /// Remove an existing DHCP option from the layer

    /// @param[in] optionType The DHCP option type to remove

    /// @return True if DHCP option was successfully removed or false if type wasn't found or if removal failed

    bool removeOption(DhcpOptionTypes optionType);

    /// Remove all DHCP options in this layer

    /// @return True if all DHCP options were successfully removed or false if removal failed for some reason

    bool removeAllOptions();

    /// A static method that checks whether a pair of ports are considered DHCP ports

    /// @param[in] portSrc The source port number to check

    /// @param[in] portDst The destination port number to check

    /// @return True if these are DHCP port numbers, false otherwise

    static inline bool isDhcpPorts(uint16_t portSrc, uint16_t portDst);

    // implement abstract methods

    /// Does nothing for this layer (DhcpLayer is always last)

    void parseNextLayer() override

    {}

    /// @return The size of @ref dhcp_header + size of options

    size_t getHeaderLen() const override

    {

      return m_DataLen;

    }

    /// Calculate the following fields:

    /// - @ref dhcp_header#magicNumber = DHCP magic number (0x63538263)

    /// - @ref dhcp_header#opCode = ::DHCP_BOOTREQUEST for message types: ::DHCP_DISCOVER, ::DHCP_REQUEST,

    /// ::DHCP_DECLINE, ::DHCP_RELEASE,

    ///                            ::DHCP_INFORM, ::DHCP_UNKNOWN_MSG_TYPE

    ///                            ::DHCP_BOOTREPLY for message types: ::DHCP_OFFER, ::DHCP_ACK, ::DHCP_NAK

    /// - @ref dhcp_header#hardwareType = 1 (Ethernet)

    /// - @ref dhcp_header#hardwareAddressLength = 6 (MAC address length)

    void computeCalculateFields() override;

    std::string toString() const override;

    OsiModelLayer getOsiModelLayer() const override

    {

      return OsiModelApplicationLayer;

    }

  private:

    uint8_t* getOptionsBasePtr() const

    {

      return m_Data + sizeof(dhcp_header);

    }

    TLVRecordReader<DhcpOption> m_OptionReader;

    void initDhcpLayer(size_t numOfBytesToAllocate);

    DhcpOption addOptionAt(const DhcpOptionBuilder& optionBuilder, int offset);

  };

  // implementation of inline methods

  bool DhcpLayer::isDhcpPorts(uint16_t portSrc, uint16_t portDst)

  {

    return ((portSrc == 68 && portDst == 67) || (portSrc == 67 && portDst == 68) ||

            (portSrc == 67 && portDst == 67));

  }

}  // namespace pcpp