t_rcvdis(3)t_rcvdis(3)NAMEt_rcvdis - Retrieve disconnect information
SYNOPSIS
#include <xti.h>
int t_rcvdis(
int fd,
struct t_discon *discon );
LIBRARY
XTI Library (libxti.a)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
t_rcvdis(): XNS4.0, XNS5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
PARAMETERS
The following table summarizes the relevance of input and output param‐
eters before and after t_rcvdis() is called:
────────────────────────────────────────────────
Parameter Before Call After Call
────────────────────────────────────────────────
fd y n
discon->udata.maxlen y n
discon->udata.len n y
discon->udata.buf o (o)
discon->reason n y
discon->sequence n o
────────────────────────────────────────────────
Notes to Table: This is a meaningful parameter. This is not a meaning‐
ful parameter. This an optional parameter. The content of the object
pointed to by y is optional.
Specifies a file descriptor returned by the t_open() function that
identifies the transport endpoint where a disconnect occurred. Points
to a type t_discon structure used to specify user-data parameters that
can be returned by the transport user. The t_discon structure has the
following members: Specifies a buffer for transport user data sent to
the caller with the disconnect when the t_rcvdis() function is pro‐
cessed. The type netbuf structure referenced by this member is defined
in the xti.h include file and has the following members: Specifies the
maximum byte length of the data buffer. Specifies the actual byte
length of data written to the buffer. Points to the buffer location.
Specifies the reason the disconnect occurred. Specifies the sequence
number identifying an outstanding connection indication that has been
disconnected. The field sequence is only meaningful when the t_rcvdis()
function is issued by a passive transport user who has issued one or
more t_listen() functions and is processing the resulting connect indi‐
cations.
On return, the discon->udata buffer contains information associ‐
ated with the disconnect. Before the t_rcvdis() function is
called, udata.maxlen must be set to specify the maximum byte
length of the user-data buffer.
The discon->reason parameter specifies the reason for the dis‐
connect using a protocol-dependent reason code. When protocol
independence is a concern, this information should not be exam‐
ined.
When this function is called after issuing one or more t_lis‐
ten() functions, and there is more than one outstanding trans‐
port endpoint connection (refer to the t_listen() function), the
discon->sequence parameter is used to specify the outstanding
connection indication with which the disconnect is associated.
When a transport user is not concerned with incoming remote
transport user data, with a reason for a disconnect, or with the
sequence number of the transport endpoint where the disconnect
took place, the discon parameter may be specified as a null
pointer. When discon is specified as a null pointer, no data is
returned to the caller.
When a transport user knows there is more than one active con‐
nection indication (refer to the t_look() function), and this
function is called with the discon parameter set to the null
pointer value, there is no way to identify the connection where
the disconnect occurred.
DESCRIPTION
The t_rcvdis() XTI connection-oriented function is used to identify the
cause of a disconnect at a transport endpoint specified by a file
descriptor returned by the t_open() function, and to retrieve any user
data sent with the disconnect.
RETURN VALUES
Upon successful completion, a value of 0 (zero) is returned. Otherwise,
a value of -1 is returned and t_errno is set to indicate the error.
ERRORS
If the t_rcvdis() function fails, t_errno is set to one of the follow‐
ing values: File descriptor fd does not refer to a valid transport end‐
point. No disconnect indication currently exists on the transport end‐
point specified by the fd parameter. The number of bytes allocated for
incoming data is not sufficient to store the data. When fd specifies a
passive transport endpoint (the number of outstanding connection indi‐
cations is greater than 1), the transport endpoint remains in state
T_INCON; otherwise, the transport endpoint state becomes T_IDLE. A
system error occurred during execution of this function. The
t_rcvdis() function was issued in the wrong sequence on the transport
endpoint referenced by the fd parameter. This function is not sup‐
ported by the underlying transport provider. This error indicates that
a communication problem has been detected between XTI and the transport
provider for which there is no other suitable XTI(t_errno).
VALID STATES
The t_rcvdis() function can be called in the following transport
provider states: T_DATAXFER, T_OUTCON, T_OUTREL, T_INREL, and T_INCON
(when the number of outstanding connections is greater than 0 (zero)).
SEE ALSO
Functions: t_alloc(3), t_connect(3), t_listen(3), t_open(3), t_snd‐
dis(3)
Standards: standards(5)
Network Programmer's Guide
t_rcvdis(3)
