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UDPSocket Class Reference

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

#include <socket.h>

Inheritance diagram for UDPSocket:

Socket UDPBroadcast UDPReceive UDPTransmit UDPDuplex UDPDuplex List of all members.

Public Member Functions

 UDPSocket (Family family=IPV4)
 Create an unbound UDP socket, mostly for internal use.
 UDPSocket (const IPV4Address &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.
Error setLoopback (bool enable)
 Set the loopback.
Error setMulticast (bool enable)
 Set the multicast.
Error setTimeToLive (char ttl)
 Set time to live.
void setPeer (const IPV4Host &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 IPV4Multicast &ia, int InterfaceIndex)
 join a multicast group on a particular interface
ssize_t send (const void *buf, size_t len)
 Send a message packet to a peer host.
ssize_t receive (void *buf, size_t len)
 Receive a message from any host.
IPV4Host getIPV4Peer (tpport_t *port=NULL) const
 Examine address of sender of next waiting packet.
IPV4Host getPeer (tpport_t *port=NULL) const
ssize_t peek (void *buf, size_t len)
 Examine contents of next waiting packet.
Error disconnect (void)
 Disassociate this socket from any host connection.

Protected Attributes

union {
   sockaddr_in   ipv4
peer
Family family

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>


Constructor & Destructor Documentation

UDPSocket::UDPSocket Family  family = IPV4  ) 
 

Create an unbound UDP socket, mostly for internal use.

UDPSocket::UDPSocket const IPV4Address 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.


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 and ipv6 specific implementation.

IPV4Host UDPSocket::getIPV4Peer 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.

IPV4Host UDPSocket::getPeer tpport_t port = NULL  )  const [inline]
 

Reimplemented from Socket.

Socket::Error UDPSocket::join const IPV4Multicast 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 and ipv6 specific implementation.

ssize_t 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.

ssize_t 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.

ssize_t 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.

Reimplemented in UDPTransmit.

Error UDPSocket::setLoopback bool  enable  )  [inline]
 

Set the loopback.

Error UDPSocket::setMulticast bool  enable  )  [inline]
 

Set the multicast.

Reimplemented in UDPTransmit, and UDPReceive.

void UDPSocket::setPeer const IPV4Host 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.

Error UDPSocket::setTimeToLive char  ttl  )  [inline]
 

Set time to live.


Member Data Documentation

Family UDPSocket::family [protected]
 

struct sockaddr_in UDPSocket::ipv4 [protected]
 

union { ... } UDPSocket::peer [protected]
 


The documentation for this class was generated from the following file:
Generated on Tue Jan 18 14:32:39 2005 for GNU CommonC++ by  doxygen 1.3.9.1