t_getinfo(3) t_getinfo(3)
NAME [Toc] [Back]
t_getinfo() - get protocol-specific service information
SYNOPSIS [Toc] [Back]
#include <xti.h> /* for X/OPEN Transport Interface - XTI */
/* or */
#include <tiuser.h> /* for Transport Layer Interface - TLI */
int t_getinfo (fd, info);
int fd;
struct info *info;
DESCRIPTION [Toc] [Back]
The t_getinfo() function returns the current characteristics of the
underlying transport protocol associated with file descriptor fd. The
info structure is used to return the same information returned by
t_open(). This function enables a transport user to access this
information during any phase of communication.
This argument points to a t_info structure which contains the
following members:
t_scalar_t addr; /* max size of the transport protocol address */
t_scalar_t options; /* max number of bytes of protocol-specific options */
t_scalar_t tsdu; /* max size of a transport service data unit,TSDU */
t_scalar_t etsdu; /* max size of expedited transport service data unit,ETSDU */
t_scalar_t connect; /* max data allowed on connection establishment functions */
t_scalar_t discon; /* max data allowed on t_snddis and t_rcvdis functions */
t_scalar_t servtype; /* service type supported by the transport provider */
t_scalar_t flags; /* other info about the transport provider */
The values of the fields have the following meanings:
addr A value greater than or equal to zero indicates the
maximum size of a transport protocol address.
A value of -1 specifies that there is no limit on the
address size.
A value of -2 specifies that the transport provider
does not provide user access to transport protocol
addresses.
options A value greater than or equal to zero indicates the
maximum number of bytes of protocol-specific options
supported by the provider.
A value of -1 specifies that there is no limit on the
option size.
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003
t_getinfo(3) t_getinfo(3)
A value of -2 specifies that the transport provider
does not support user-settable options.
tsdu A value greater than zero specifies the maximum size
of a transport service data unit (TSDU)
A value of zero specifies that the transport provider
does not support the concept of TSDU 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 on the
size of a TSDU.
A value of -2 specifies that the transfer of normal
data is not supported by the transport provider.
etsdu A value greater than zero specifies the maximum size
of an expedited transport service data unit (ETSDU).
A value of zero specifies that the transport provider
does not support the concept of ETSDU although it
does support the sending of an expedited data stream
with no logical boundaries preserved across a
connection.
A value of -1 specifies that there is no limit on the
size of an ETSDU.
A value of -2 specifies that the transfer of
expedited data is not supported by the transport
provider.
connect A value greater than or equal to zero specifies the
maximum amount of data that may be associated with
the connection establishment functions t_connect()
and t_rcvconnect().
A value of -1 specifies that there is no limit on the
amount of data sent during connection establishment.
A value of -2 specifies that the transport provider
does not allow data to be sent with connection
establishment functions.
discon A value greater than or equal to zero specifies the
maximum amount of data that may be associated with
the t_snddis() and t_rcvdis() functions.
A value of -1 specifies that there is no limit on the
amount of data sent with these abortive release
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: August 2003
t_getinfo(3) t_getinfo(3)
functions.
A value of -2 specifies that the transport provider
does not allow data to be sent with the abortive
release functions.
servtype This field specifies the service type supported by
the transport provider, as described below.
flags This is a bit field used to specify other information
about the transport provider. If the T_SENDZERO bit
is set in flags, this indicates that the underlying
transport provider supports the sending of zerolength
TSDUs. See Appendix A, "ISO Transport
Protocol Information" of the CAE Specification X/Open
Transport Interface (XTI) manual for a discussion of
the separate issue of zero-length fragments within a
TSDU. Note: HP currently does not support T_SENDZERO
flag within the timod module.
If a transport user is concerned with protocol independence, the above
sizes may be accessed to determine how large the buffers must be to
hold each piece of information. Alternatively, the t_alloc() function
may be used to allocate these buffers. An error will result if a
transport user exceeds the allowed data size on any function. The
value of each field may change as a result of option negotiation, and
t_getinfo() enables a user to retrieve the current characteristics of
the underlying transport protocol.
The servtype field of info specifies one of the following values on
return:
T_COTS The transport provider supports a connection-mode
service but does not support the optional orderly
release facility.
T_COTS_ORD The transport provider supports a connection-mode
service with the optional orderly release facility.
T_CLTS The transport provider supports a connectionless-mode
service. For this service type, t_open() will return
-2 for etsdu, connect, and discon.
Thread-Safeness [Toc] [Back]
The t_getinfo() function is safe to be called by multithreaded
applications, and it is thread-safe for both POSIX Threads and DCE
User Threads. It has a cancellation point. It is neither asynccancel
safe nor async-signal safe. Finally, it is not fork-safe.
Valid States [Toc] [Back]
All - apart from T_UNINIT.
Hewlett-Packard Company - 3 - HP-UX 11i Version 2: August 2003
t_getinfo(3) t_getinfo(3)
RETURN VALUE [Toc] [Back]
Upon successful completion, a value of 0 is returned. Otherwise, a
value of -1 is returned, and t_errno is set to indicate the error.
ERRORS [Toc] [Back]
On failure, t_errno is set to the following
[TBADF] The specified identifier does not refer to a
transport endpoint.
[TSYSERR] A system error has occurred during execution of this
function.
[TPROTO] (XTI only) This error indicates that a communication
problem has been detected between XTI and the
transport provider for which there is no suitable XTI
(t_errno).
SEE ALSO [Toc] [Back]
t_alloc(3), t_open(3).
STANDARDS CONFORMANCE [Toc] [Back]
t_getinfo(): SVID2, XPG3, XPG4
Hewlett-Packard Company - 4 - HP-UX 11i Version 2: August 2003 [ Back ] |
