DHCP message codec. More...

#include <dhcp_message.hpp>

Public Types
enum	MessageType : uint8_t { Discover = 1 , Offer = 2 , Request = 3 , Decline = 4 , Ack = 5 , Nak = 6 , Release = 7 , Inform = 8 }
	DHCP message types, RFC 2132 section 9.6. More...

enum	Operation : uint8_t { BootRequest = 1 , BootReply = 2 }
	DHCP operation codes. More...

enum	Flag : uint16_t { BroadcastFlag = 0x8000 }
	message flags. More...

enum	Overload : uint8_t { FileOverload = 1 , SnameOverload = 2 }
	option overload values. More...

Public Member Functions
int	serialize (const DhcpPacket &packet, std::stringstream &data) const
	serialize a DHCP message into a byte stream.

int	deserialize (DhcpPacket &packet, std::stringstream &data) const
	deserialize a DHCP message from a byte stream.

Static Public Attributes
static constexpr uint32_t	magicCookie = 0x63825363
	magic cookie introducing the option field.

static constexpr size_t	headerSize = 240
	size of the fixed part of a DHCP message, magic cookie included.

static constexpr size_t	minMsgSize = 300
	smallest message a BOOTP implementation accepts, RFC 951 and RFC 1542 section 2.1.

static constexpr size_t	maxOptionSize = 255
	biggest payload a single option can carry, its length field is one octet.

Protected Member Functions
int	serialize (const DhcpOption &options, std::stringstream &data) const
	serialize an option list into a byte stream.

int	deserialize (DhcpOption &options, std::stringstream &data) const
	deserialize an option list from a byte stream.

bool	deserialize (DhcpOption &options, const char *field, size_t size) const
	deserialize an option list from an overloaded field.

Static Protected Member Functions
static bool	writeHead (std::ostream &data, uint8_t code, size_t size)
	write an option header into a byte stream.

static void	writeAddress (std::ostream &data, const IpAddress &address)
	write an IPv4 address into a byte stream.

static bool	readAddress (std::istream &data, IpAddress &address)
	read an IPv4 address from a byte stream.

static bool	extract (std::istream &data, void *out, size_t size)
	read a fixed amount of bytes from a byte stream.

Static Protected Attributes
static constexpr uint8_t	_ethernet = 1
	hardware address type of an Ethernet link.

static constexpr size_t	_chaddrSize = 16
	size of the client hardware address field.

static constexpr size_t	_snameSize = 64
	size of the server name field.

static constexpr size_t	_fileSize = 128
	size of the boot file name field.

Detailed Description

DHCP message codec.

Member Enumeration Documentation

◆ Flag

enum join::DhcpMessage::Flag : uint16_t

message flags.

Enumerator
BroadcastFlag	the client asks to be answered by broadcast.

◆ MessageType

enum join::DhcpMessage::MessageType : uint8_t

DHCP message types, RFC 2132 section 9.6.

Enumerator
Discover	a client looking for a server.
Offer	a server proposing an address.
Request	a client asking for an address.
Decline	a client refusing an address already in use.
Ack	a server confirming an address.
Nak	a server refusing a request.
Release	a client giving an address back.
Inform	a client asking for parameters only.

◆ Operation

enum join::DhcpMessage::Operation : uint8_t

DHCP operation codes.

Enumerator
BootRequest	message sent by a client.
BootReply	message sent by a server.

◆ Overload

enum join::DhcpMessage::Overload : uint8_t

option overload values.

Enumerator
FileOverload	the file field carries options.
SnameOverload	the sname field carries options.

Member Function Documentation

◆ deserialize() [1/3]

bool join::DhcpMessage::deserialize	(	DhcpOption &	options,
		const char *	field,
		size_t	size ) const

inlineprotected

deserialize an option list from an overloaded field.

Parameters

options	option list to deserialize into.
field	field holding the options to deserialize.
size	field size.

Returns: true on success, false on failure.

◆ deserialize() [2/3]

int DhcpMessage::deserialize	(	DhcpOption &	options,
		std::stringstream &	data ) const

protected

deserialize an option list from a byte stream.

Parameters

options	option list to deserialize into.
data	byte stream holding the options to deserialize.

Returns: 0 on success, -1 on failure.

◆ deserialize() [3/3]

int join::DhcpMessage::deserialize	(	DhcpPacket &	packet,
		std::stringstream &	data ) const

inline

deserialize a DHCP message from a byte stream.

Parameters

packet	DHCP message to deserialize into.
data	byte stream holding the message to deserialize.

Returns: 0 on success, -1 on failure.

◆ extract()

static bool join::DhcpMessage::extract	(	std::istream &	data,
		void *	out,
		size_t	size )

inlinestaticprotected

read a fixed amount of bytes from a byte stream.

Parameters

data	byte stream to read from.
out	buffer to read into.
size	number of bytes to read.

Returns: true if every byte was read, false otherwise.

◆ readAddress()

static bool join::DhcpMessage::readAddress	(	std::istream &	data,
		IpAddress &	address )

inlinestaticprotected

read an IPv4 address from a byte stream.

Parameters

data	byte stream to read from.
address	address read.

Returns: true on success, false on failure.

◆ serialize() [1/2]

int DhcpMessage::serialize	(	const DhcpOption &	options,
		std::stringstream &	data ) const

protected

serialize an option list into a byte stream.

Parameters

options	options to serialize.
data	byte stream to serialize the options into.

Returns: 0 on success, -1 on failure.

◆ serialize() [2/2]

int join::DhcpMessage::serialize	(	const DhcpPacket &	packet,
		std::stringstream &	data ) const

inline

serialize a DHCP message into a byte stream.

Parameters

packet	DHCP message to serialize.
data	byte stream to serialize the message into.

Returns: 0 on success, -1 on failure.

◆ writeAddress()

static void join::DhcpMessage::writeAddress	(	std::ostream &	data,
		const IpAddress &	address )

inlinestaticprotected

write an IPv4 address into a byte stream.

Parameters

data	byte stream to write to.
address	address to write.

◆ writeHead()

bool DhcpMessage::writeHead	(	std::ostream &	data,
		uint8_t	code,
		size_t	size )

staticprotected

write an option header into a byte stream.

Parameters

data	byte stream to write to.
code	option code.
size	option payload size.

Returns: true if the payload fits in an option, false otherwise.

Member Data Documentation

◆ _chaddrSize

size_t join::DhcpMessage::_chaddrSize = 16

staticconstexprprotected

size of the client hardware address field.

◆ _ethernet

uint8_t join::DhcpMessage::_ethernet = 1

staticconstexprprotected

hardware address type of an Ethernet link.

◆ _fileSize

size_t join::DhcpMessage::_fileSize = 128

staticconstexprprotected

size of the boot file name field.

◆ _snameSize

size_t join::DhcpMessage::_snameSize = 64

staticconstexprprotected

size of the server name field.

◆ headerSize

size_t join::DhcpMessage::headerSize = 240

staticconstexpr

size of the fixed part of a DHCP message, magic cookie included.

◆ magicCookie

uint32_t join::DhcpMessage::magicCookie = 0x63825363

staticconstexpr

magic cookie introducing the option field.

◆ maxOptionSize

size_t join::DhcpMessage::maxOptionSize = 255

staticconstexpr

biggest payload a single option can carry, its length field is one octet.

◆ minMsgSize

size_t join::DhcpMessage::minMsgSize = 300

staticconstexpr

smallest message a BOOTP implementation accepts, RFC 951 and RFC 1542 section 2.1.

The documentation for this class was generated from the following files:

fabric/include/join/dhcp_message.hpp
fabric/src/dhcp_message.cpp

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Static Protected Member Functions

Static Protected Attributes

Detailed Description

Member Enumeration Documentation

◆ Flag

◆ MessageType

◆ Operation

◆ Overload

Member Function Documentation

◆ deserialize() [1/3]

◆ deserialize() [2/3]

◆ deserialize() [3/3]

◆ extract()

◆ readAddress()

◆ serialize() [1/2]

◆ serialize() [2/2]

◆ writeAddress()

◆ writeHead()

Member Data Documentation

◆ _chaddrSize

◆ _ethernet

◆ _fileSize

◆ _snameSize

◆ headerSize

◆ magicCookie

◆ maxOptionSize

◆ minMsgSize