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


See attributes(5) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT Level | Safe |
+---------------+-----------------+

SEE ALSO


t_alloc(3NSL), t_connect(3NSL), t_listen(3NSL), t_open(3NSL),
t_snddis(3NSL), attributes(5)


May 7, 1998 T_RCVDIS(3NSL)