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Technical Standard: Networking Services (XNS), Issue 5.2 Draft 2.0
Copyright © 1999 The Open Group


t_snddis - send user-initiated disconnection request


#include <xti.h>

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


Parameters Before call After call

fd x /
call->addr.maxlen = =
call->addr.len = =
call->addr.buf = =
call->opt.maxlen = =
call->opt.len = =
call->opt.buf = =
call->udata.maxlen = =
call->udata.len x =
call->udata.buf ?(?) =
call->sequence ? =

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() or t_getinfo(). If the len field of udata is zero, no data will be sent to the remote user.




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

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

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

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

An asynchronous event, which requires attention, has occurred.

This function is not supported by the underlying transport provider.

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

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).

A system error has occurred during execution of this function.


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.


t_connect(), t_getinfo(), t_listen(), t_open().


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


Issue 4

The SYNOPSIS section is placed in the form of a standard C function prototype.

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