t_getinfo(3)						     Library Functions Manual						      t_getinfo(3)

NAME

       t_getinfo() - get protocol-specific service information

SYNOPSIS

DESCRIPTION

       The  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 communication.

       This argument points to a 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.

			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 and

			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 func-
			tions.

       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.

			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 bit  is  set  in  flags,  this
			indicates  that  the underlying transport provider supports the sending of zero-length TSDUs.  See Appendix A, "ISO Trans-
			port Protocol Information" of the manual for a discussion of the separate issue of zero-length fragments  within  a  TSDU.
			Note: HP currently does not support flag within the 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 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 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:

       The transport provider supports a connection-mode service but does not support
			the optional orderly release facility.

       The transport provider supports a connection-mode service with the optional
			orderly release facility.

       The transport provider supports a connectionless-mode service.  For this
			service type, will return -2 for etsdu, connect, and discon.

   Valid States
       All - apart from

   Fork Safety
       is not fork-safe.

RETURN VALUE

       Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned, and is set to indicate the error.

ERRORS

       On failure, 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 (

SEE ALSO

       t_alloc(3), t_open(3), thread_safety(5).

STANDARDS CONFORMANCE

																      t_getinfo(3)