UDPSocket Class Reference

UDP sockets implement the TCP SOCK_DGRAM UDP protocol. Unreliable Datagram Protocol sockets. More...

#include <socket.h>

Inheritance diagram for UDPSocket:

List of all members.

Public Member Functions
	UDPSocket (void)
	Create an unbound UDP socket, mostly for internal use.
	UDPSocket (const InetAddress &bind, tpport_t port)
	Create a UDP socket and bind it to a specific interface and port address so that other UDP sockets on remote machines (or the same host) may find and send UDP messages to it.
virtual	~UDPSocket ()
	Destroy a UDP socket as a socket.
void	setPeer (const InetHostAddress &host, tpport_t port)
	set the peer address to send message packets to.
Socket::Error	getInterfaceIndex (const char *ethX, int &InterfaceIndex)
	get the interface index for a named network device
Socket::Error	join (const InetMcastAddress &ia, int InterfaceIndex)
	join a multicast group on a particular interface
int	send (const void *buf, size_t len)
	Send a message packet to a peer host.
int	receive (void *buf, size_t len)
	Receive a message from any host.
InetHostAddress	getPeer (tpport_t *port=NULL) const
	Examine address of sender of next waiting packet.
int	peek (void *buf, size_t len)
	Examine contents of next waiting packet.
Error	disconnect (void)
	Disassociate this socket from any host connection.
Protected Attributes
sockaddr_in	peer

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Detailed Description

UDP sockets implement the TCP SOCK_DGRAM UDP protocol. Unreliable Datagram Protocol sockets.

They can be used to pass unverified messages between hosts, or to broadcast a specific message to an entire subnet. Please note that Streaming of realtime data commonly use UDPDuplex related classes rather than UDPSocket.

In addition to connected TCP sessions, Common C++ supports UDP sockets and these also cover a range of functionality. Like a TCPSocket, A UDPSocket can be created bound to a specific network interface and/or port address, though this is not required. UDP sockets also are usually either connected or otherwise "associated" with a specific "peer" UDP socket. Since UDP sockets operate through discreet packets, there are no streaming operators used with UDP sockets.

In addition to the UDP "socket" class, there is a "UDPBroadcast" class. The UDPBroadcast is a socket that is set to send messages to a subnet as a whole rather than to an individual peer socket that it may be associated with.

UDP sockets are often used for building "realtime" media streaming protocols and full duplex messaging services. When used in this manner, typically a pair of UDP sockets are used together; one socket is used to send and the other to receive data with an associated pair of UDP sockets on a "peer" host. This concept is represented through the Common C++ UDPDuplex object, which is a pair of sockets that communicate with another UDPDuplex pair.

Author:

David Sugar <dyfet@ostel.com>

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Constructor & Destructor Documentation

UDPSocket::UDPSocket (  void   )

Create an unbound UDP socket, mostly for internal use.

UDPSocket::UDPSocket (  const InetAddress &  bind, tpport_t  port )

Create a UDP socket and bind it to a specific interface and port address so that other UDP sockets on remote machines (or the same host) may find and send UDP messages to it. On failure to bind, an exception is thrown. Parameters: bind  address to bind this socket to. port  number to bind this socket to.

virtual UDPSocket::~UDPSocket (   )  [virtual]

Destroy a UDP socket as a socket.

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Member Function Documentation

Error UDPSocket::disconnect (  void   )

Disassociate this socket from any host connection. No data should be read or written until a connection is established. Reimplemented in UDPDuplex.

Socket::Error UDPSocket::getInterfaceIndex (  const char *  ethX, int &  InterfaceIndex )

get the interface index for a named network device Parameters: ethX  is device name, like "eth0" or "eth1" InterfaceIndex  is the index value returned by os Todo: Win32 implementation.

InetHostAddress UDPSocket::getPeer (  tpport_t *  port = NULL  )  const

Examine address of sender of next waiting packet. This also sets "peer" address to the sender so that the next "send" message acts as a "reply". This additional behavior overides the standard socket getSender behavior. Parameters: port  pointer to hold port number. Reimplemented from Socket.

Socket::Error UDPSocket::join (  const InetMcastAddress &  ia, int  InterfaceIndex )

join a multicast group on a particular interface Parameters: ia  is the multicast address to use InterfaceIndex  is the index value returned by getInterfaceIndex Todo: Win32 implementation.

int UDPSocket::peek (  void *  buf, size_t  len )  [inline]

Examine contents of next waiting packet. Parameters: buf  pointer to packet buffer for contents. len  of packet buffer. Returns: number of bytes examined.

int UDPSocket::receive (  void *  buf, size_t  len )  [inline]

Receive a message from any host. Parameters: buf  pointer to packet buffer to receive. len  of packet buffer to receive. Returns: number of bytes received. Reimplemented in UDPReceive.

int UDPSocket::send (  const void *  buf, size_t  len )  [inline]

Send a message packet to a peer host. Parameters: buf  pointer to packet buffer to send. len  of packet buffer to send. Returns: number of bytes sent.

void UDPSocket::setPeer (  const InetHostAddress &  host, tpport_t  port )

set the peer address to send message packets to. This can be set before every send() call if nessisary. Parameters: host  address to send packets to. port  number to deliver packets to.

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Member Data Documentation

struct sockaddr_in UDPSocket::peer [protected]

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

• socket.h

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