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UDP Sockets
[Socket API]

Collaboration diagram for UDP Sockets:

Detailed Description

UDP sockets.

Nut/Net supports connectionless UDP sockets only.


Functions

UDPSOCKET * NutUdpCreateSocket (u_short port)
 Create an UDP socket.
int NutUdpSendTo (UDPSOCKET *sock, u_long addr, u_short port, void *data, u_short len)
 Send an UDP datagram.
int NutUdpReceiveFrom (UDPSOCKET *sock, u_long *addr, u_short *port, void *data, u_short size, u_long timeout)
 Receive an UDP datagram.
int NutUdpDestroySocket (UDPSOCKET *sock)
 Close UDP socket.
UDPSOCKET * NutUdpFindSocket (u_short port)
 Find a matching socket.
int NutUdpSetSockOpt (UDPSOCKET *sock, int optname, CONST void *optval, int optlen)
 Set value of a UDP socket option.
int NutUdpGetSockOpt (UDPSOCKET *sock, int optname, void *optval, int optlen)
 Get a UDP socket option value.

Variables

UDPSOCKET * udpSocketList

Function Documentation

UDPSOCKET* NutUdpCreateSocket (  u_short  port  ) 
 

Create an UDP socket.

Parameters:
port Server applications provide the local port number with this parameter. Client applications should pass zero.
Returns:
Socket descriptor of the newly created UDP socket or 0 if there is not enough memory left.

int NutUdpDestroySocket (  UDPSOCKET *  sock  ) 
 

Close UDP socket.

The memory occupied by the socket is immediately released after calling this function. The application must not use the socket after this call.

Parameters:
sock Socket descriptor. This pointer must have been retrieved by calling NutUdpCreateSocket().
Returns:
0 on success, -1 otherwise.

UDPSOCKET* NutUdpFindSocket (  u_short  port  ) 
 

Find a matching socket.

Loop through all sockets and find a matching one.

Note:
Applications typically do not need to call this function.
Parameters:
port Local port number.
Returns:
Socket descriptor.

int NutUdpGetSockOpt (  UDPSOCKET *  sock,
int  optname,
void *  optval,
int  optlen
) 
 

Get a UDP socket option value.

The following values can be set:

  • SO_RCVBUF Socket input buffer size (u_short).

Parameters:
sock Socket descriptor. This pointer must have been retrieved by calling NutUdpCreateSocket().
optname Option to get.
optval Points to a buffer receiving the value.
optlen Length of the value buffer.
Returns:
0 on success, -1 otherwise.

int NutUdpReceiveFrom (  UDPSOCKET *  sock,
u_long *  addr,
u_short *  port,
void *  data,
u_short  size,
u_long  timeout
) 
 

Receive an UDP datagram.

Parameters:
sock Socket descriptor. This pointer must have been retrieved by calling NutUdpCreateSocket().
addr IP address of the remote host in network byte order.
port Remote port number in host byte order.
data Pointer to the buffer that receives the data.
size Size of the buffer that receives the data.
timeout Maximum number of milliseconds to wait.
Returns:
The number of bytes received, if successful. The return value -1 indicates an error. On timeout 0 is returned.
Note:
Timeout is limited to the granularity of the system timer.

int NutUdpSendTo (  UDPSOCKET *  sock,
u_long  addr,
u_short  port,
void *  data,
u_short  len
) 
 

Send an UDP datagram.

Parameters:
sock Socket descriptor. This pointer must have been retrieved by calling NutUdpCreateSocket().
addr IP address of the remote host in network byte order.
port Remote port number in host byte order.
data Pointer to a buffer containing the data to send.
len Number of bytes to be sent.
Returns:
0 on success, -1 otherwise.

int NutUdpSetSockOpt (  UDPSOCKET *  sock,
int  optname,
CONST void *  optval,
int  optlen
) 
 

Set value of a UDP socket option.

The following values can be set:

  • SO_RCVBUF Socket input buffer size (u_short).

Parameters:
sock Socket descriptor. This pointer must have been retrieved by calling NutUdpCreateSocket().
optname Option to set.
optval Pointer to the value.
optlen Length of the value.
Returns:
0 on success, -1 otherwise.

Variable Documentation

UDPSOCKET* udpSocketList
 

Linked list of all UDP sockets.