t_open(3xti) t_open(3xti)
Name
t_open - establish a transport endpoint
Syntax
#include <xti.h>
#include <fcntl.h>
int t_open(name, oflag, info)
char *name;
int oflag;
struct t_info *info;
Arguments
name Points to a transport provider identifier.
oflag Identifies any open flags as in The oflag argument is constructed from O_RDWR optionally ORed with O_NONBLOCK. These flags are
defined by the header file <fcntl.h>.
info Returns various default characteristics of the underlying transport protocol by setting fields in the info structure. This argu-
ment points to a structure that contains the following members:
long addr /* max size of the transport protocol address */
long options /* max number of bytes of protocol specific options */
long tsdu /* max size of a transport service data unit (TSDU) */
long etsdu /* max size of expedited transport service data unit (ETSDU) */
long connect /* max amount of data allowed on connection establishment functions */
long discon /* max amount of data allowed on and functions */
long servtype /* service type supported by 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; and 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 sup-
ported by the provider; a value of -1 specifies that there is no limit on the option size; and 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 an ETSDU; and 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 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; and a value -2 specifies that the transfer of expe-
dited 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 connec-
tion establishment functions; a value of -1 specifies that there is no limit on the amount of data sent during
connection establishment; and 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 and
functions; a value of -1 specifies that there is no limit on the amount of data sent with these abortive release
functions; and a -2 specifies that the transport provider does not allow data to be sent with abortive release
functions.
servtype This field specifies the service type supported by the transport provider, as described.
If a transport user is concerned with protocol independence, the sizes can be accessed to determine how large the buffers must be to hold
each piece of information. Alternately, the 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 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 facil-
ity.
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, returns -2 for etsdu, con-
nect, and discon.
A single transport endpoint may support only one of the above services at one time. If info is set to NULL by the transport user, no pro-
tocol information is returned by
Description
The function must be called as the first step in the initialization of a transport endpoint. This function establishes a transport end-
point by supplying a transport provider identifier that indicates a particular transport provider, that is a transport protocol, and
returns a file descriptor that identifies that endpoint.
The function returns a file descriptor that is used by all subsequent functions to identify that particular local transport endpoint.
------------------------------------------
Parameters Before Call After Call
------------------------------------------
name x /
oflag x /
info->addr / x
info->options / x
info->tsdu / x
info->etsdu / x
info->connect / x
info->discon / x
info->servtype / x
------------------------------------------
Return Values
Upon successful completion, returns a file descriptor. On failure, -1 is returned, and t_errno is set to indicate the error.
Diagnostics
On failure, t_errno is set to one of the following:
[TBADFLAG] An invalid flag is specified.
[TBADNAME] Invalid transport provider name.
[TSYSERR] A system error has occurred during execution of this function.
See Also
open(2)
t_open(3xti)