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T_RCVDIS(3NSL) Networking Services Library Functions T_RCVDIS(3NSL)

NAME

t_rcvdis - retrieve information from disconnection

SYNOPSIS

#include <xti.h>

int t_rcvdis(int fd, struct t_discon *discon);

DESCRIPTION

This routine is part of the XTI interfaces which evolved from the TLI
interfaces. XTI represents the future evolution of these interfaces.
However, TLI interfaces are supported for compatibility. When using a
TLI routine that has the same name as an XTI routine, the tiuser.h
header file must be used. Refer to the TLI COMPATIBILITY section
for a description of differences between the two interfaces.

This function is used to identify the cause of a disconnection and to
retrieve any user data sent with the disconnection. The argument fd
identifies the local transport endpoint where the connection existed,
and discon points to a t_discon structure containing the following
members:

struct netbuf udata;
int reason;
int sequence;

The field reason specifies the reason for the disconnection through a
protocol-dependent reason code, udata identifies any user data that
was sent with the disconnection, and sequence may identify an
outstanding connection indication with which the disconnection is
associated. The field sequence is only meaningful when t_rcvdis() is
issued by a passive transport user who has executed one or more
t_listen(3NSL) functions and is processing the resulting connection
indications. If a disconnection indication occurs, sequence can be
used to identify which of the outstanding connection indications is
associated with the disconnection.

The maxlen field of udata may be set to zero, if the user does not
care about incoming data. If, in addition, the user does not need to
know the value of reason or sequence, discon may be set to NULL and
any user data associated with the disconnection indication shall be
discarded. However, if a user has retrieved more than one outstanding
connection indication by means of t_listen(3NSL), and discon is a
null pointer, the user will be unable to identify with which
connection indication the disconnection is associated.

RETURN VALUES

Upon successful completion, a value of 0 is returned. Otherwise, a
value of -1 is returned and t_errno is set to indicate an error.

VALID STATES

T_DATAXFER, T_OUTCON, T_OUTREL, T_INREL, T_INCON(ocnt > 0).

ERRORS

On failure, t_errno is set to one of the following:

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

TBUFOVFLW
The number of bytes allocated for incoming data
(maxlen) is greater than 0 but not sufficient to store
the data. If fd is a passive endpoint with ocnt > 1,
it remains in state T_INCON; otherwise, the endpoint
state is set to T_IDLE.

TNODIS
No disconnection indication currently exists on the
specified transport endpoint.

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

TOUTSTATE
The communications endpoint referenced by fd is not
in one of the states in which a call to this function
is valid.

TPROTO
This error indicates that a communication problem has
been detected between XTI and the transport provider
for which there is no other suitable XTI error
(t_errno).

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

TLI COMPATIBILITY

The XTI and TLI interface definitions have common names but use
different header files. This, and other semantic differences between
the two interfaces are described in the subsections below.

Interface Header

The XTI interfaces use the header file, xti.h. TLI interfaces should
not use this header. They should use the header:
#include <tiuser.h>

Error Description Values

The t_errno values TPROTO and TOUTSTATE can be set by the XTI
interface but not by the TLI interface.

A failure return, and a t_errno value that this routine can set under
different circumstances than its XTI counterpart is TBUFOVFLW. It can
be returned even when the maxlen field of the corresponding buffer
has been set to zero.

ATTRIBUTES