t_getinfo(3)t_getinfo(3)NAMEt_getinfo - Get protocol-specific information
SYNOPSIS
#include <xti.h>
int t_getinfo(
int fd,
struct t_info *info );
LIBRARY
XTI Library (libxti.a)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
t_getinfo(): 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‐
eter data before and after t_info() is called:
──────────────────────────────────────────
Parameter Before Call After Call
──────────────────────────────────────────
fd y n
info->addr n y
info->options n y
info->tsdu n y
info->etsdu n y
info->connect n y
info->discon n y
info->servtype n y
info->options n y
──────────────────────────────────────────
Notes to table: This a meaningful parameter. This is not a meaningful
parameter. Specifies a file descriptor returned by the t_open() func‐
tion that identifies the local transport endpoint. Points to a type
t_info structure that is returned when t_getinfo() executes. Parameters
defined by the t_info structure specify characteristics of the underly‐
ing transport protocol associated with the fd file descriptor.
When the info parameter is set to the null pointer value by a
transport user, no protocol information is returned by the
t_getinfo() function.
When a transport user must preserve protocol independence, data
length information defined by members of the t_info structure
pointed to by the info parameter may be accessed to determine
how large data buffers must be to hold exchanged data. Alterna‐
tively, the t_alloc() function may be used to allocate necessary
data buffers. An error results when a transport user exceeds the
allowed data length during any data exchange.
Values associated with parameters of the t_info structure may
change as the result of protocol option negotiations during ini‐
tialization of a connection. The t_info structure has the fol‐
lowing members: Specifies the permitted number of bytes in the
protocol address. A value greater than zero indicates the maxi‐
mum number of permitted bytes in a protocol address. A value of
-1 specifies that there is no limit on the protocol address
size. A value of -2 specifies that the transport provider does
not permit the transport user access to the protocol addresses.
Specifies the permitted number of bytes of options. A value
greater than zero indicates the maximum number of bytes of pro‐
tocol-specific options supported by the transport provider. A
value of -1 specifies that there is no limit to the number of
options bytes. A value of -2 specifies that the transport
provider does not permit a transport user to set options. Spec‐
ifies the permitted number of bytes in a Transport Service Data
Unit (TSDU). A value greater than zero specifies the maximum
number of bytes in a TSDU message. A value of zero specifies
that the transport provider does not support TSDU data
exchanges, although it does support the sending of a data stream
with no logical boundaries preserved across a connection. A
value of -1 specifies that there is no limit to the number of
bytes in a TSDU data exchange. A value of -2 specifies that the
transfer of normal data is not supported by the transport
provider. Specifies the permitted number of bytes in an Expe‐
dited Transport Service Data Unit (ETSDU). A value greater than
zero specifies the maximum number of bytes in an ETSDU data
exchange. A value of zero specifies that the transport provider
does not support ETSDU data exchanges, although it does support
the sending of an expedited data stream with no logical bound‐
aries preserved across a connection. A value of -1 specifies
that there is no limit on the number of bytes in an ETSDU data
exchange. A value of -2 specifies that the transfer of expedited
data is not supported by the transport provider. Specifies the
permitted number of bytes of data in a connect request. A value
greater than zero specifies the maximum number of data bytes
that may be exchanged using the t_connect() or t_rcvconnect()
function. A value of -2 specifies that the transport provider
does not permit data to be sent when a connection is estab‐
lished. Specifies the permitted number of bytes of data in a
disconnect request. A value greater than zero specifies the max‐
imum number of data bytes that may be exchanged using the t_snd‐
dis() or t_rcvdis() function. A value of -1 specifies that there
is no limit to the number of data bytes that may be sent when a
connection is closed using these abortive release functions. A
value of -2 specifies that the transport provider does not per‐
mit data to be sent with an abortive release function. Speci‐
fies only one of the following types of service supported by the
transport provider: The transport provider supports connection-
mode service but does not support the optional orderly release
facility. The transport provider supports connection-mode ser‐
vice with the optional orderly release facility. The transport
provider supports connectionless mode service. For this service
type, the t_open() function returns the value -2 for the etsdu,
connect, and discon parameters. Specifies other information
about the transport provider. If the T_SENDZERO bit is set in
flags, this indicates that the underlying transport provider
supports sending zero-length TSDUs.
DESCRIPTION
The t_getinfo() function is an XTI general utility function that pro‐
vides information about the underlying transport protocol associated
with a file descriptor previously returned by the t_open() function.
The t_getinfo() function returns the same protocol-specific information
as does t_open() in theinfo parameter.
ERRORS
If the t_getinfo() function fails, t_errno may be set to one of the
following values: File descriptor fd does not refer to a valid trans‐
port endpoint. A system error occurred during execution of this func‐
tion. 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_getinfo() function can be called in any transport provider state
except T_UNINIT.
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_alloc(3), t_open(3)
Standards: standards(5)
Network Programmer's Guide
t_getinfo(3)
