t_sndudata(3N)t_sndudata(3N)NAMEt_sndudata - send a data unit
SYNOPSIS
#ifdef _XOPEN_SOURCE
#include <xti.h>
#else
#include <tiuser.h>
#endif
int t_sndudata (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.
This function resides within both the X/Open compliant libxnet and the
SVR4 compliant libnsl Network Services libraries. Network Services
applications which require X/Open compliance must link-load with -lxnet.
Network Services applications which require SVR4 compliance must link-
load with -lnsl.
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t_sndudata(3N)t_sndudata(3N)
On failure, t_errno may be set to one of the following:
TBADF The specified file descriptor does not refer to a
transport endpoint.
TFLOW O_NDELAY or O_NONBLOCK was set, but the flow control
mechanism prevented the transport provider from
accepting data at this time.
TNOTSUPPORT This function is not supported by the underlying
transport provider.
TOUTSTATE If _XOPEN_SOURCE is defined and t_sndudata() is issued
in the wrong sequence on the transport endpoint
referenced by fd, the TOUTSTATE error value is returned
within the variable t_errno.
TSYSERR A system error has occurred during execution of this
function.
TBADDATA There are multiple conditions which could cause this
t_errno to be generated. One condition is: nbytes is
zero and sending zero bytes is not supported by the
transport provider. Another condition is: if
_XOPEN_SOURCE is defined and a single send was
attempted specifying a TSDU greater than that specified
by the current values of the TSDU field in the info
argument.
SEE ALSOintro(3N), fcntl(2), t_alloc(3N), t_open(3N), t_rcvudata(3N),
t_rcvuderr(3N)DIAGNOSTICSt_sndudata returns 0 on successful completion and -1 on failure t_errno
is set to indicate the error.
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