t_sndreldata(3) — Subroutines
NAME
t_sndreldata − Initiate or respond to an orderly release with user data
SYNOPSIS
#include <xti.h>
int t_sndreldata(
int fd,
struct t_discon ∗discon );
LIBRARY
XTI Library (libxti.a)
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
t_sndreldata(): 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 parameters before and after t_sndreldata() is called:
| Parameters | Before Call | After Call |
| fd | y | n |
| discon->udata.maxlen | y | e |
| discon->udata.len | y | n |
| discon->udata.buf | o(o) | n |
| discon->reason | o | n |
| discon->sequence | n | n |
Notes to Table:
yThis is a meaningful parameter.
(y)The content of the object pointed to by y is meaningful.
oThis is a meaningful but optional parameter.
(o)The content of the object pointed to by o is meaningful.
eThe parameter value after the call is the same as before the call.
nThis is not a meaningful parameter.
fdIdentifies the local transport endpoint where the connection exists.
discon
Points to a t_discon structure that contains the following members:
struct netbuf udata
Identifies any user data that was sent with the disconnection.
int reason
Specifies a protocol-dependent reason code that explains the disconnection.
int sequence
Unused.
If a user does not wish to send data and reason code to the remote user, the value of discon may be a null pointer.
DESCRIPTION
The t_sndreldata() function is an XTI connection mode service function that is used to initiate an orderly release of the outgoing direction of data transfer and to send user data with the release.
After calling t_sndreldata(), the user may not send any more data over the connection. However, a user may continue to receive data if an orderly release indication has not been received.
The reason field specifies the reason for the disconnection through a protocol-dependent reason code, and udata identifies any user data that is sent with the disconnection; the sequence field is not used.
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 or if the provider did not return T_ORDRELDATA in the t_open() flags, no data will be sent to the remote user.
This function is an optional service of the transport provider, only supported by providers of service type T_COTS_ORD. The T_ORDRELDATA flagin the info->flag field returned by t_open() or t_getinfo() indicates that the provider supports orderly release user data; when the flag is not set, this function behaves as t_rcvrel() and no user data is returned.
This function may not be available on all systems.
ERRORS
If the t_sndreldata() function fails, t_errno may be set to one of the following values:
[TBADDATA]
The amount of user data specified was not within the bounds allowed by the transport provider, or user data was supplied and the provider did not return T_ORDRELDATA in the t_open() flags.
[TBADF]
File descriptor (fd) is not a valid transport endpoint.
[TFLOW]
O_NONBLOCK was set, but the flow control mechanism prevented the transport provider from accepting the function.
[TLOOK]
An asynchronous event occurred on this transport endpoint and requires immediate attention.
[TNOTSUPPORT]
Orderly release is not supported by the underlying transport provider.
[TOUTSTATE]
The communications endpoint referenced by fd is not in a valid state in which a call to this function.
[TPROTO]
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 occurred during execution of this function.
VALID STATES
The t_sndreldata() function can be called in either the T_DATAXFER or T_OUTREL transport provider states.
RETURN VALUE
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.
SEE ALSO
Functions: t_getinfo(3), t_open(3), t_rcvrel(3), t_rcvreldata(3), t_sndrel(3).
Standards: standards(5)
Network Programmer’s Guide