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


NAME


t_snddis - send user-initiated disconnection request

SYNOPSIS


#include <xti.h>


int t_snddis(int fd, const struct t_call *call);


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 initiate an abortive release on an already
established connection, or to reject a connection request. The argument
fd identifies the local transport endpoint of the connection, and call
specifies information associated with the abortive release. The argument
call points to a t_call structure which contains the following members:

struct netbuf addr;
struct netbuf opt;
struct netbuf udata;
int sequence;


The values in call have different semantics, depending on the context of
the call to t_snddis(). When rejecting a connection request, call must be
non-null and contain a valid value of sequence to uniquely identify the
rejected connection indication to the transport provider. The sequence
field is only meaningful if the transport connection is in the T_INCON
state. The addr and opt fields of call are ignored. In all other cases,
call need only be used when data is being sent with the disconnection
request. The addr, opt and sequence fields of the t_call structure are
ignored. If the user does not wish to send data to the remote user, the
value of call may be a null pointer.


The udata structure specifies the user data to be sent to the remote
user. The amount of user data must not exceed the limits supported by the
transport provider, as returned in the discon field, of the info argument
of t_open(3NSL) or t_getinfo(3NSL). If the len field of udata is zero, no
data will be sent to the remote user.

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.


TBADDATA
The amount of user data specified was not within the
bounds allowed by the transport provider.


TBADSEQ
An invalid sequence number was specified, or a null call
pointer was specified, when rejecting a connection
request.


TLOOK
An asynchronous event, which requires attention, has
occurred.


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 value TPROTO can be set by the XTI interface but not by the
TLI interface.

Option Buffers


The format of the options in an opt buffer is dictated by the transport
provider. Unlike the XTI interface, the TLI interface does not fix the
buffer format.

ATTRIBUTES


See attributes(7) for descriptions of the following attributes:


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

SEE ALSO


t_connect(3NSL), t_getinfo(3NSL), t_listen(3NSL), t_open(3NSL),
t_snd(3NSL), attributes(7)

WARNINGS


t_snddis() is an abortive disconnection. Therefore a t_snddis() issued on
a connection endpoint may cause data previously sent by means of
t_snd(3NSL), or data not yet received, to be lost, even if an error is
returned.


May 7, 1998 T_SNDDIS(3NSL)