DHCP client. More...

#include <dhcp.hpp>

Inheritance diagram for join::BasicDhcpClient< Protocol >:

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Collaboration diagram for join::BasicDhcpClient< Protocol >:

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Public Member Functions
	BasicDhcpClient ()=delete
	create the BasicDhcpClient instance.

	BasicDhcpClient (const std::string &interface, uint16_t maxSize=0, const std::string &hostname={}, Reactor &reactor=ReactorThread::reactor())
	create the instance bound to the given interface.

	~BasicDhcpClient ()
	stop receiving messages and destroy the instance.

DhcpPacket	compose (uint8_t type) const
	build a message carrying what every message a client sends has in common.

int	exchange (DhcpPacket &request, DhcpPacket &answer, const IpAddress &destination, uint8_t expected, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	send a message and wait for its answer.

std::string	reason () const
	get the reason the server gave for the last refusal.

int	discover (DhcpPacket &offer, const IpAddress &wants=IpAddress::ipv4Wildcard, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	broadcast a DISCOVER message and wait for an OFFER.

int	request (DhcpPacket &ack, const IpAddress &wants, const IpAddress &server, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	broadcast a REQUEST message and wait for an ACK.

int	renew (DhcpPacket &ack, const IpAddress &client, const IpAddress &server, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	send a REQUEST message to the server holding the lease and wait for an ACK.

int	inform (DhcpPacket &ack, const IpAddress &client, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	ask a server for the parameters of an externally configured address.

int	release (const IpAddress &client, const IpAddress &server, std::chrono::milliseconds timeout=std::chrono::seconds(1)) noexcept
	give a lease back to the server holding it.

int	decline (const IpAddress &address, const IpAddress &server, const std::string &message={}) noexcept
	tell the server that the address it offered is already in use.

Additional Inherited Members
Protected Types inherited from join::BasicDhcp< Protocol >
using	Socket = typename Protocol::Socket

Protected Member Functions inherited from join::BasicDhcp< Protocol >
struct	__attribute__ ((packed, aligned(2))) Frame
	link, internet and transport headers a DHCP message is framed with.

struct	__attribute__ ((packed, aligned(2))) Pseudo
	header the UDP checksum is computed over, RFC 768.

void	attach ()
	register with the reactor, to be called by the final class once fully constructed.

void	detach () noexcept
	unregister from the reactor, to be called by the final class before destruction starts.

int	send (const char *data, size_t size, const MacAddress &to, const IpAddress &source, const IpAddress &destination) noexcept
	frame a message and write it on the wire.

ssize_t	receive (char *data, size_t maxSize, MacAddress &from, MacAddress &to) noexcept
	read a message that passed the link, internet and transport checks.

	BasicDhcp ()=delete
	create the BasicDhcp instance.

	BasicDhcp (const std::string &interface, Reactor &reactor=ReactorThread::reactor())
	create the instance bound to the given interface.

	BasicDhcp (const BasicDhcp &other)=delete
	create instance by copy.

BasicDhcp &	operator= (const BasicDhcp &other)=delete
	assign instance by copy.

	BasicDhcp (BasicDhcp &&other)=delete
	create instance by move.

BasicDhcp &	operator= (BasicDhcp &&other)=delete
	assign instance by move.

virtual	~BasicDhcp ()=default
	destroy the instance.

const std::string &	interface () const noexcept
	get the name of the interface the instance is bound to.

const MacAddress &	hardware () const noexcept
	get the hardware address of the interface the instance is bound to.

Protected Member Functions inherited from join::EventHandler
virtual void	onEvent (int fd, uint32_t revents)
	method called when events are reported on handle.

virtual void	onWriteable (int fd)
	method called when data are ready to be written on handle.

virtual void	onClose (int fd)
	method called when handle was closed by the peer.

virtual void	onError (int fd)
	method called when an error occurred on handle.

	EventHandler ()=default
	create instance.

	EventHandler (const EventHandler &other)=default
	copy constructor.

EventHandler &	operator= (const EventHandler &other)=default
	copy assignment operator.

	EventHandler (EventHandler &&other)=default
	move constructor.

EventHandler &	operator= (EventHandler &&other)=default
	move assignment operator.

virtual	~EventHandler ()=default
	destroy instance.

Static Protected Member Functions inherited from join::BasicDhcp< Protocol >
static uint16_t	udpChecksum (const Frame &frame, const char *payload, size_t size) noexcept
	compute the checksum of a UDP datagram, RFC 768.

Protected Attributes inherited from join::BasicDhcp< Protocol >
Socket	_socket
	underlying socket.

DhcpMessage	_message
	DHCP message codec.

std::unique_ptr< char[]>	_buffer
	receive buffer.

const std::string	_interface
	interface name.

const MacAddress	_hardware
	hardware address of the interface.

Reactor &	_reactor
	event loop reactor.

Detailed Description

template<class Protocol>
class join::BasicDhcpClient< Protocol >

DHCP client.

Constructor & Destructor Documentation

◆ BasicDhcpClient() [1/2]

template<class Protocol >

join::BasicDhcpClient< Protocol >::BasicDhcpClient ( )

delete

create the BasicDhcpClient instance.

◆ BasicDhcpClient() [2/2]

template<class Protocol >

join::BasicDhcpClient< Protocol >::BasicDhcpClient	(	const std::string &	interface,
		uint16_t	maxSize = 0,
		const std::string &	hostname = {},
		Reactor &	reactor = ReactorThread::reactor () )

inlineexplicit

create the instance bound to the given interface.

Parameters

interface	interface name.
maxSize	biggest message the server may send back, zero to leave it unspecified.
hostname	host name to advertise, empty to advertise none.
reactor	reactor instance.

Exceptions

std::system_error if the interface is unknown, the socket could not be bound to it, or the maximum message size is below what RFC 2132 allows.

◆ ~BasicDhcpClient()

template<class Protocol >

join::BasicDhcpClient< Protocol >::~BasicDhcpClient ( )

inline

stop receiving messages and destroy the instance.

Member Function Documentation

◆ compose()

template<class Protocol >

DhcpPacket join::BasicDhcpClient< Protocol >::compose ( uint8_t type ) const

inline

build a message carrying what every message a client sends has in common.

Parameters

type	message type.

Returns: the message.

◆ decline()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::decline	(	const IpAddress &	address,
		const IpAddress &	server,
		const std::string &	message = {} )

inlinenoexcept

tell the server that the address it offered is already in use.

Parameters

address	address the client refuses.
server	address of the server that offered it.
message	human readable reason, empty to give none.

Returns: 0 on success, -1 on failure.

◆ discover()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::discover	(	DhcpPacket &	offer,
		const IpAddress &	wants = IpAddress::ipv4Wildcard,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

broadcast a DISCOVER message and wait for an OFFER.

Parameters

offer	offer received.
wants	address the client would like to get, wildcard to let the server choose.
timeout	answer timeout.

Returns: 0 on success, -1 on failure.

◆ exchange()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::exchange	(	DhcpPacket &	request,
		DhcpPacket &	answer,
		const IpAddress &	destination,
		uint8_t	expected,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

send a message and wait for its answer.

Parameters

request	message to send.
answer	answer received.
destination	destination address.
expected	message type the answer must carry.
timeout	answer timeout.

Returns: 0 on success, -1 on failure.

◆ inform()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::inform	(	DhcpPacket &	ack,
		const IpAddress &	client,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

ask a server for the parameters of an externally configured address.

Parameters

ack	acknowledgement received.
client	address the client already owns.
timeout	answer timeout.

Returns: 0 on success, -1 on failure.

◆ reason()

template<class Protocol >

std::string join::BasicDhcpClient< Protocol >::reason ( ) const

inline

get the reason the server gave for the last refusal.

Returns: the reason, empty if the server gave none or if nothing was refused.

◆ release()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::release	(	const IpAddress &	client,
		const IpAddress &	server,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

give a lease back to the server holding it.

Parameters

client	address the client currently owns.
server	address of the server holding the lease.
timeout	time allowed to resolve the server hardware address.

Returns: 0 on success, -1 on failure.

◆ renew()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::renew	(	DhcpPacket &	ack,
		const IpAddress &	client,
		const IpAddress &	server,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

send a REQUEST message to the server holding the lease and wait for an ACK.

Parameters

ack	acknowledgement received.
client	address the client currently owns.
server	address of the server holding the lease.
timeout	answer timeout.

Returns: 0 on success, -1 on failure.

◆ request()

template<class Protocol >

int join::BasicDhcpClient< Protocol >::request	(	DhcpPacket &	ack,
		const IpAddress &	wants,
		const IpAddress &	server,
		std::chrono::milliseconds	timeout = std::chrono::seconds (1) )

inlinenoexcept

broadcast a REQUEST message and wait for an ACK.

Parameters

ack	acknowledgement received.
wants	address the client asks to be assigned.
server	address of the server the offer came from.
timeout	answer timeout.

Returns: 0 on success, -1 on failure.

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

fabric/include/join/dhcp.hpp
fabric/include/join/dhcp_protocol.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ BasicDhcpClient() [1/2]

◆ BasicDhcpClient() [2/2]

◆ ~BasicDhcpClient()

Member Function Documentation

◆ compose()

◆ decline()

◆ discover()

◆ exchange()

◆ inform()

◆ reason()

◆ release()

◆ renew()

◆ request()