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)