NAME

t_sndudata − send a data unit

SYNOPSIS

#include <tiuser.h>

int t_sndudata (fd, unitdata)
int fd;
struct t_unitdata ∗unitdata;

DESCRIPTION

This function is used in connectionless mode to send a data unit to another transport user.  fd identifies the local transport endpoint through which data will be sent, and unitdata points to a t_unitdata structure containing the following members:

struct netbuf addr;
struct netbuf opt;
struct netbuf udata;

netbuf is described in intro(3N).  In unitdata, addr specifies the protocol address of the destination user, opt identifies protocol-specific options that the user wants associated with this request, and udata specifies the user data to be sent.  The user may choose not to specify what protocol options are associated with the transfer by setting the len field of opt to zero.  In this case, the provider may use default options. 

If the len field of udata is zero, and the sending of zero bytes is not supported by the underlying transport provider, t_sndudata will return −1 with t_errno set to TBADDATA. 

By default, t_sndudata operates in synchronous mode and may wait if flow control restrictions prevent the data from being accepted by the local transport provider at the time the call is made.  However, if O_NDELAY or O_NONBLOCK is set (via t_open or fcntl), t_sndudata will execute in asynchronous mode and will fail under such conditions. 

If t_sndudata is issued from an invalid state, or if the amount of data specified in udata exceeds the TSDU size as returned in the tsdu field of the info argument of t_open or t_getinfo, the provider will generate an EPROTO protocol error.  (See TSYSERR below.)  If the state is invalid, this error may not occur until a subsequent reference is made to the transport endpoint. 

On failure, t_errno may be set to one of the following:

[TBADF] The specified file descriptor does not refer to a transport endpoint. 

[TBADDATA] nbytes is zero and sending zero bytes is not supported by the transport provider. 

[TFLOW] O_NDELAY or O_NONBLOCK was set, but the flow control mechanism prevented the transport provider from accepting data at this time. 

[TLOOK] An asynchronous event has occurred on the transport endpoint and requires immediate attention. 

[TNOTSUPPORT]
This function is not supported by the underlying transport provider.

[TOUTSTATE] The function was issued in the wrong sequence. 

[TSYSERR] A system error has occurred during execution of this function. 

SEE ALSO

intro(3N), t_rcvudata(3N), t_rcvuderr(3N).  CX/UX Networking Reference Manual

DIAGNOSTICS

t_sndudata returns 0 on successful completion and −1 on failure t_errno is set to indicate the error. 

CX/UX Networking