t_getinfo(3xti) t_getinfo(3xti)
Name
t_getinfo - get protocol-specific service information
Syntax
#include <xti.h>
int t_getinfo(fd, info)
int fd;
struct t_info *info;
Arguments
fd Identifies the file descriptor that is associated with the underlying transport protocol from which the current characteristics
are to be returned.
info Specifies the structure that is used to return the same information returned by Points to a t_info structure which 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 an 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 spec-
ifies 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 supported 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 speci-
fies 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 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 of
zero specifies that the transport provider does not support the concept of ETSDU, although it 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 ETSDU; and 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 connection
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 func-
tions; a value -1 specifies that there is no limit on the amount of data sent with these abortive release functions;
and 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.
If a transport user is concerned with protocol independence, the sizes may be accessed to determine how large the buffers must be
to hold each piece of information. Alternatively, the function can be used to allocate these buffers. An error results if a
transport user exceeds the allowed data size on any function. The value of each field may change as a result of option negotia-
tion, and 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, returns -2 for ETSDU, and
Description
This function returns the current characteristics of the underlying transport protocol associated with file descriptor fd. The info struc-
ture is used to return the same information returned by This function enables a transport user to access this information during any phase
of communications.
-----------------------------------------
Parameters Before Call After Call
-----------------------------------------
fd x /
info->addr / x
info->options / x
info->tsdu / x
info->etsdu / x
info->connect / x
info->discon / x
info->sertype / x
-----------------------------------------
Return Values
Upon successful completion, a value of 0 is returned. On failure, a value of -1 is returned, and t_errno is set to indicate the error.
Diagnostics
On failure, t_errno is set to one of the following:
[TBADF] The specified file descriptor does not refer to a transport endpoint.
[TNOTSUPPORT] This function is not supported by the current implementation of XTI.
[TSYSERR] A system error has occurred during execution of this function.
See Also
t_alloc(3xti), t_open(3xti)
t_getinfo(3xti)