--- name: "UDPSocket" section: "3cc" platform: "linux" package: "libcommoncpp2-dev" version: "1.0.13-5" release: "Debian 3.1 (Sarge)" platforms: ["linux"] url: "https://new.carta.tech/UDPSocket" --- # UDPSocket(3cc) UDP sockets implement the TCP SOCK\_DGRAM UDP protocol. Unreliable Datagram Protocol sockets. ## NAME UDPSocket - UDP sockets implement the TCP SOCK\_DGRAM UDP protocol. Unreliable Datagram Protocol sockets. ## SYNOPSIS `#include ` Inherits **Socket**. Inherited by **UDPBroadcast**, **UDPReceive**` [protected]`, and **UDPTransmit**` [protected]`. ### Public Methods **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.* ### Protected Attributes sockaddr\_in **peer**\ ## 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 \ ## 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.* ## MEMBER FUNCTION DOCUMENTATION ### 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.* ## MEMBER DATA DOCUMENTATION ### struct sockaddr\_in UDPSocket::peer` [protected]` ## AUTHOR *Generated automatically by Doxygen for CommonC++ from the source code.*