Internet socket class. More...

#include <simple_socket/InternetSocket.h>

Inheritance diagram for NET::InternetSocket:

Collaboration diagram for NET::InternetSocket:

Public Types
enum	ShutdownDirection { STOP_SEND = SHUT_WR , STOP_RECEIVE = SHUT_RD , STOP_BOTH = SHUT_RDWR }

Public Member Functions
void	setReuseAddress (bool enable)
	Enable or disable local address reuse.
void	connect (std::string_view foreignAddress, unsigned short foreignPort)
	establish a connection with the given foreign address and port
int	timedConnect (std::string_view foreignAddress, unsigned short foreignPort, int timeout)
	establish a connection with the given foreign address and port
void	bind (unsigned short localPort=0)
void	bind (std::string_view localAddress, unsigned short localPort=0)
	bind socket to address / port
std::string	getLocalAddress () const
unsigned short	getLocalPort () const
std::string	getForeignAddress () const
unsigned short	getForeignPort () const
AddressFamily	addressFamily () const noexcept
	return wether this socket was created for IPv4 or IPv6
int	nativeHandle () noexcept
	return the native handle of the open socket
int	send (const void *buffer, size_t len)
	send data through a connected socket
int	receive (void *buffer, size_t len)
	receive data from a bound socket
int	timedReceive (void *buffer, size_t len, int timeout)
	receive data from a bound socket, return after the given timespan
void	disconnect ()
	Disconnect and unset any foreign addresses.
void	shutdown (ShutdownDirection type)
	shutdown the connection in the specified direction
bool	peerDisconnected () const noexcept
	returns whether a currently associated peer disconnected

Protected Member Functions
	InternetSocket (int sockfd)
	create socket from a SocketHandle returned by an accept() call
	InternetSocket (AddressFamily family, int type, int protocol)
	allows a subclass to create new socket
void	listen (int backlog=5)
	listen for incoming connections
int	sendAll (const void *buffer, size_t len)
	send data through a connected socket
int	receiveAll (void *buffer, size_t len)
	receive exactly the requested amount unless the peer disconnects
int	accept () const
	allows stream sockets to accept connections into Handles
int	timedAccept (int timeout) const
	allows stream sockets timed accept

Protected Attributes
AddressFamily	m_family
int	m_socket
bool	m_peerDisconnected
bool	m_connectionOriented

Detailed Description

Internet socket class.

InternetSocket is the base class for all sockets that use address/port to identify communication endpoints. Those are all classes that are used for protocols that build on the IP protocol. (TCP/UDP/etc.). It provides the basic interface for connecting and binding the socket to an address/interface.

Definition at line 16 of file InternetSocket.h.

Member Enumeration Documentation

◆ ShutdownDirection

enum NET::SimpleSocket::ShutdownDirection

inherited

Enumerator
STOP_SEND	disable all variants of send() on the socket, receive calls still work
STOP_RECEIVE	disable all variants of receive() on the socket, send calls still work
STOP_BOTH	disable all send() and receive() calls on the socket

Definition at line 57 of file SimpleSocket.h.

Constructor & Destructor Documentation

◆ InternetSocket() [1/2]

InternetSocket::InternetSocket ( int sockfd )

explicitprotected

create socket from a SocketHandle returned by an accept() call

Definition at line 62 of file InternetSocket.cpp.

◆ InternetSocket() [2/2]

InternetSocket::InternetSocket	(	AddressFamily	family,
		int	type,
		int	protocol )

protected

allows a subclass to create new socket

Definition at line 57 of file InternetSocket.cpp.

Member Function Documentation

◆ accept()

int SimpleSocket::accept ( ) const

protectedinherited

allows stream sockets to accept connections into Handles

Definition at line 144 of file SimpleSocket.cpp.

◆ addressFamily()

AddressFamily NET::InternetSocket::addressFamily ( ) const

inlinenoexcept

return wether this socket was created for IPv4 or IPv6

Definition at line 117 of file InternetSocket.h.

◆ bind() [1/2]

void InternetSocket::bind	(	std::string_view	localAddress,
		unsigned short	localPort = 0 )

bind socket to address / port

Set the local port to the specified port and the local address to an interface.

bind() attaches the local endpoint of the socket to the specified interface and port. Typically all servers use bind() to attach to the local port specified by the used protocol. You just need to call bind if you want to restrict the connection to a specific local interface, or if you want to listen on a specific port. If you are just a client using connect() to connect to a server, calling bind is most likely unnecessary.

To bind to a port < 1023 you need eighter superuser access, or the SUID bit set on your program.

Parameters

localAddress	local address
localPort	local port

Exceptions

SocketException thrown if setting local port fails

Definition at line 140 of file InternetSocket.cpp.

◆ bind() [2/2]

void InternetSocket::bind ( unsigned short localPort = 0 )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Instead of the richer function with more arguments, this bind() binds to any available interface / address

Examples: TCP_Server.cpp, UDP_Commands.cpp, and UDP_Multicast.cpp.

Definition at line 132 of file InternetSocket.cpp.

◆ connect()

void InternetSocket::connect	(	std::string_view	foreignAddress,
		unsigned short	foreignPort )

establish a connection with the given foreign address and port

If you are using a connection oriented socket (like TCPSocket), you have to call connect() on that socket in order to send data. However, if you are using a non-connection oriented socket (like UDPSocket), calling connect on that socket will allow you to use the send() function like on a connection oriented socket. If not connected, you would have to use sendTo

Parameters

foreignAddress	foreign address
foreignPort	foreign port

Exceptions

SocketException thrown if unable to establish connection

Examples: TCP_Client.cpp.

Definition at line 74 of file InternetSocket.cpp.

◆ disconnect()

void SimpleSocket::disconnect ( )

inherited

Disconnect and unset any foreign addresses.

This will ungracefully abort the connection by sending an RST frame. disconnect() should not be used under normal circumstances, as it will terminate the connection OOB, preventing the other end of the communication from retrieving data that would still be available in the OS buffer.

For normal termination of a connection use shutdown().

Exceptions

SocketException thrown if unable to disconnect

Definition at line 112 of file SimpleSocket.cpp.

◆ getForeignAddress()

std::string InternetSocket::getForeignAddress ( ) const

Get the foreign address. Call connect() before using this function.

Returns: foreign address

Exceptions

SocketException thrown if unable to fetch foreign address

Examples: TCP_Server.cpp.

Definition at line 168 of file InternetSocket.cpp.

◆ getForeignPort()

unsigned short InternetSocket::getForeignPort ( ) const

Get the foreign port. Call connect() before using this function.

Returns: foreign port

Exceptions

SocketException thrown if unable to fetch foreign port

Examples: TCP_Server.cpp.

Definition at line 178 of file InternetSocket.cpp.

◆ getLocalAddress()

std::string InternetSocket::getLocalAddress ( ) const

Get the local address (after binding the socket).

Returns: local address of socket

Exceptions

SocketException thrown if fetch fails

Definition at line 148 of file InternetSocket.cpp.

◆ getLocalPort()

unsigned short InternetSocket::getLocalPort ( ) const

Get the local port (after binding the socket).

Returns: local port of socket

Exceptions

SocketException thrown if fetch fails

Definition at line 158 of file InternetSocket.cpp.

◆ listen()

void SimpleSocket::listen ( int backlog = 5 )

protectedinherited

listen for incoming connections

listen() can be called on a bound socket. The socket will then go into a passive state and accept incoming connections. To answer to an incoming connection call accept() or timedAccept() on the socket.

The backlog is a buffer for incoming connections. If backlog is set to 0, the number of incoming connections is only limited by the operating system. If backlog is set to a value > 0, only the upper limit of connections is set, the OS can limit the number further.

After starting to listen, use accept to accept incoming connections.

Parameters

backlog upper limit of pending incoming connections

Exceptions

SocketException

Definition at line 137 of file SimpleSocket.cpp.

◆ nativeHandle()

int NET::SimpleSocket::nativeHandle ( )

inlinenoexceptinherited

return the native handle of the open socket

Definition at line 68 of file SimpleSocket.h.

◆ peerDisconnected()

bool SimpleSocket::peerDisconnected ( ) const

noexceptinherited

returns whether a currently associated peer disconnected

For stream sockets this is set when the peer closes or resets the connection. Use this function after a call to receive, returned 0 received bytes.

For connected datagram sockets it may also be set when the network reports that the configured peer is unreachable.

The flag is cleared by a successful connect().

Returns: true if a peer disconnected

Examples: TCP_Client.cpp.

Definition at line 132 of file SimpleSocket.cpp.

◆ receive()

int SimpleSocket::receive	(	void *	buffer,
		size_t	len )

inherited

receive data from a bound socket

receive() can only be used on a socket that called bind() or connect() before. If you try to use receive() on a not bound socket, SocketException will be thrown.

If using a stream oriented Socket, receive can return a part of a received messge, e.g. if you send 100 bytes, it's possible you will receive 50 bytes two times in a row. However, the order of the sent data will be preserved.

If you are using a datagram oriented sockets, you will only receive whole datagrams. But beware of using a too small buffer. If the receive buffer is too small for the received datagram, the data you didn't read in the receive call will be discared.

If the remote host has closed the connection (on a connection based socket like TCP or SCTP) receive() will return 0. If you are using a connectionless protocol (like UDP) there is no way to determine wheter the connection has been closed by the remote host or not.

Parameters

buffer	the buffer the received data will be written to
len	length of the provided buffer, receive will not read more than that

Returns: number of bytes received

Exceptions

SocketException in case an error occured

Definition at line 70 of file SimpleSocket.cpp.

◆ receiveAll()

int SimpleSocket::receiveAll	(	void *	buffer,
		size_t	len )

protectedinherited

receive exactly the requested amount unless the peer disconnects

receiveAll() repeatedly calls receive() until len bytes have been received. This is useful for fixed-size data on TCP, where one receive() call is not guaranteed to return all bytes sent by the peer.

If the peer closes or resets the connection before len bytes arrive, the function returns the number of bytes received so far. In that case peerDisconnected() is set by the underlying receive() call.

Parameters

buffer	buffer the received data will be written to
len	number of bytes to receive

Returns: number of bytes received

Exceptions

SocketException on receive errors other than peer loss

Definition at line 188 of file SimpleSocket.cpp.

◆ send()

int SimpleSocket::send	(	const void *	buffer,
		size_t	len )

inherited

send data through a connected socket

send() can only be used on a socket that called connect() before. If you try to use send() on a not connected socket, SocketException will be thrown.

If you are using a stream oriented socket (like TCPSocket), the operating system is allowed to send only a part of the packet you told it to send, so send() will return the number of bytes actually sent. It is your responsibility to resend the data not sent by send()

If you are using a datagram oriented socket (like UDPSocket or SCTPSocket) the operating system will only send and receive complete datagrams, but send() will fail if you are trying to send too much data. In that case SocketException will be thrown.

Parameters

buffer	data to be send
len	length of the data to be sent

Returns: number of bytes sent

Exceptions

SocketException if sending went wrong

Definition at line 50 of file SimpleSocket.cpp.

◆ sendAll()

int SimpleSocket::sendAll	(	const void *	buffer,
		size_t	len )

protectedinherited

send data through a connected socket

sendAll() can only be used on a socket that called connect() before. If you try to use sendAll() on a unconnected socket, a SocketException will be thrown.

When using a stream oriented socket, the operating system is allowed to send only a bit of the data you requested it to send. Because of this, you would have to check the number of sent bytes when using send(), and resend unsent data manually. sendAll() takes that responsibility from you and resends as long as it needs, to completely send the data given to it.

Parameters

buffer	data to be send
len	length of the data to be sent

Returns: number of bytes sent

Exceptions

SocketException

Definition at line 175 of file SimpleSocket.cpp.

◆ setReuseAddress()

void InternetSocket::setReuseAddress ( bool enable )

Enable or disable local address reuse.

SO_REUSEADDR allows binding a local address that may still be associated with previous connections, e.g. TCP connections in TIME_WAIT. This option should be set before bind().

Parameters

enable true to enable address reuse

Exceptions

SocketException if changing the option fails

Examples: TCP_Server.cpp, and UDP_Multicast.cpp.

Definition at line 67 of file InternetSocket.cpp.

◆ shutdown()

void SimpleSocket::shutdown ( ShutdownDirection type )

inherited

shutdown the connection in the specified direction

This will gracefully end a connection by sending a FIN frame. Use this to end a normal communication cycle. To abort a connection see disconnect().

Depending on the specified ShutdownDirection, calls for that direction will stop working. Use this function if you want to have more control than just destroing the socket. It allows you to cut the connection in one direction, or both.

If you use shutdown() on an unconnected socket, the corresponding calls will simply stop working.

Parameters

type	the ShutdownDirection that be used

Exceptions

SocketException in case an error occured

Examples: TCP_Server.cpp.

Definition at line 126 of file SimpleSocket.cpp.

◆ timedAccept()

int SimpleSocket::timedAccept ( int timeout ) const

protectedinherited

allows stream sockets timed accept

Definition at line 158 of file SimpleSocket.cpp.

◆ timedConnect()

int InternetSocket::timedConnect	(	std::string_view	foreignAddress,
		unsigned short	foreignPort,
		int	timeout )

establish a connection with the given foreign address and port

Provides timeout for TCP socket connection establishment. When a timeout occurs, the OS may still continue the connection attempt in the background. Use disconnect() or destroy the socket to avoid this.

Parameters

foreignAddress	foreign address
foreignPort	foreign port
timeout	the timeout in ms after which connect will give up and return

Returns: 0 on timeout, 1 when connection is established

Exceptions

SocketException thrown if unable to establish connection

Definition at line 84 of file InternetSocket.cpp.

◆ timedReceive()

int SimpleSocket::timedReceive	(	void *	buffer,
		size_t	len,
		int	timeout )

inherited

receive data from a bound socket, return after the given timespan

timedReceive() can only be used on a socket that called bind() or connect before. If you try to use receive() on a not bound socket, SocketException will be thrown.

If using a stream oriented Socket, receive can return a part of a received messge, e.g. if you send 100 bytes, it's possible you will receive 50 bytes two times in a row. However, the order of the sent data will be preserved.

If you are using a datagram oriented sockets, you will only receive whole datagrams. But beware of using a too small buffer. If the receive buffer is too small for the received datagram, the data you didn't read in the receive call will be discared.

If the remote host has closed the connection (on a connection based socket like TCP or SCTP) receive() will return 0. If you are using a connectionless protocol (like UDP) there is no way to determine wheter the connection has been closed by the remote host or not.

Parameters

buffer	the buffer the received data will be written to
len	length of the provided buffer, receive will not read more than that
timeout	the timeout in ms after which receive will give up and return

Returns: number of bytes received, 0 on timeout

Exceptions

SocketException in case an error occured

Examples: TCP_Client.cpp.

Definition at line 89 of file SimpleSocket.cpp.

Member Data Documentation

◆ m_connectionOriented

bool NET::SimpleSocket::m_connectionOriented

protectedinherited

Definition at line 268 of file SimpleSocket.h.

◆ m_family

AddressFamily NET::InternetSocket::m_family

protected

Definition at line 127 of file InternetSocket.h.

◆ m_peerDisconnected

bool NET::SimpleSocket::m_peerDisconnected

protectedinherited

Definition at line 267 of file SimpleSocket.h.

◆ m_socket

int NET::SimpleSocket::m_socket

protectedinherited

Definition at line 266 of file SimpleSocket.h.

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

include/simple_socket/InternetSocket.h
src/InternetSocket.cpp

simple-socket library 1.5.0

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

◆ ShutdownDirection

Constructor & Destructor Documentation

◆ InternetSocket() [1/2]

◆ InternetSocket() [2/2]

Member Function Documentation

◆ accept()

◆ addressFamily()

◆ bind() [1/2]

◆ bind() [2/2]

◆ connect()

◆ disconnect()

◆ getForeignAddress()

◆ getForeignPort()

◆ getLocalAddress()

◆ getLocalPort()

◆ listen()

◆ nativeHandle()

◆ peerDisconnected()

◆ receive()

◆ receiveAll()

◆ send()

◆ sendAll()

◆ setReuseAddress()

◆ shutdown()

◆ timedAccept()

◆ timedConnect()

◆ timedReceive()

Member Data Documentation

◆ m_connectionOriented

◆ m_family

◆ m_peerDisconnected

◆ m_socket