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t_open(3) Library Functions Manual t_open(3) NAME t_open - Establishes a transport endpoint LIBRARY XTI Library (libxti.a) SYNOPSIS #include <xti.h> #include <fcntl.h> int t_open( char *name, int oflag, struct t_info *info); STANDARDS Interfaces documented on this reference page conform to industry stan- dards as follows: t_open: XPG4-UNIX Refer to the standards(5) reference page for more information about in- dustry standards and associated tags. PARAMETERS The following table summarizes the relevance of input and output para- meters before and after the t_open() function is called: tab(@); lfHB lfHB lfHB l l l. _ Parameter@Before Call@After Call _ name@y@n oflag@y@n info->addr@n@y info->options@n@y info->tsdu@n@y info->etsdu@n@y info->connect@n@y info->discon@n@y info->servtype@n@y info->flags@n@y _ Notes to Table: This is a meaningful parameter. This is not a meaning- ful parameter. Identifies the transport provider. The transport provider must define the type of transport service (protocol) to asso- ciate with the opened transport endpoint. The oflag parameter is simi- lar to the oflag parameter of the open() function and is used in the same way. Use oflag to establish synchronous or asynchronous operating modes of the transport provider pointed to by the name parameter. The transport provider operating mode is specified with the O_NONBLOCK flag. The actual value for this parameter is obtained from the sym- bolic name variable O_RDWR, which may be optionally bitwise combined with a logical inclusive OR of flag O_NONBLOCK, defined in the <fc- ntl.h> header file. Points to a type t_info structure. The location of a type t_info structure is returned to the info parameter when the t_open() function successfully executes. Members of the t_info struc- ture specify default characteristics of the underlying transport proto- col pointed to by the name parameter. When the info parameter is set to the null pointer value by a transport user, no protocol information is returned by this function. When a transport user must preserve protocol independence, data length information defined by members of the type t_info struc- ture may be accessed to determine how large data buffers must be to hold exchanged data. Alternatively, the t_alloc() function may be used to allocate necessary data buffers. An error results when a transport user exceeds the allowed data length during any data exchange. This structure has the following seven members: Permitted number of bytes in the protocol address. A value greater than zero indicates the maximum number of permitted bytes in a protocol address. A value of -1 specifies that there is no limit on the protocol address size. A value of -2 speci- fies that the transport provider does not permit the transport user access to the protocol addresses. Permitted number of bytes of options. A value greater than zero indicates the maxi- mum number of bytes of protocol-specific options supported by the transport provider. A value of -1 specifies that there is no limit to the number of options bytes. A value of -2 specifies that the transport provider does not permit a transport user to set options. Permitted number of bytes in a Transport Service Data Unit (TSDU). A value greater than zero specifies the maxi- mum number of bytes in a TSDU message. A value of zero specifies that the transport provider does not support TSDU data ex- changes, 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 to the number of bytes in a TSDU data exchange. A value of -2 specifies that the transfer of normal data is not supported by the transport provider. Permitted number of bytes in an Expedited Transport Service Data Unit (ETSDU). A value greater than zero specifies the maximum number of bytes in an ETSDU data exchange. A value of zero specifies that the transport provider does not support ETSDU data exchanges, 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 number of bytes in an ETSDU data exchange. A value of -2 specifies that the transfer of expedited data is not sup- ported by the transport provider. Permitted number of bytes of data in connect request. A value greater than zero specifies the maximum number of data bytes that may be exchanged using the t_connect() and t_rcvconnect() functions. A value of -2 speci- fies that the transport provider does not permit data to be sent when a connection is established. Permitted number of bytes of data in a disconnect request. A value greater than zero speci- fies the maximum number of data bytes that may be exchanged us- ing the t_snddis() and t_rcvdis() functions. A value of -1 specifies that there is no limit to the number of data bytes that may be sent when a connection is closed using these abortive release functions. A value of -2 specifies that the transport provider does not permit data to be sent with an abortive release function. This member specifies only one of the following types of service supported by the transport provider: The transport provider supports connection-mode ser- vice but does not support the optional orderly release facility. The transport provider supports connection-mode service with the optional orderly release facility. The transport provider sup- ports connectionless-mode service. For this service type, this function returns the value -2 for the etsdu, connect, and discon parameters. Specifies other information about the transport provider. If the T_SENDZERO bit is set in flags, this indicates the underlying transport provider supports the sending of zero- length TSDUs. VALID STATES The t_open() function can be called in the T_UNINIT transport provider state only. DESCRIPTION The t_open() XTI function must be the first one called when initializ- ing a transport endpoint. Two modes of operation may be specified, syn- chronous and asynchronous. In synchronous mode, a transport user must wait for some specific event to occur before control is returned (refer to the t_look() function). In asynchronous mode, a transport user is not required to wait for the event to occur; control is returned imme- diately. The t_open() function establishes the transport endpoint by supplying a transport provider identifier that specifies a particular transport protocol. A file descriptor, which must subsequently always be used to identify the established endpoint, is returned by this function. RETURN VALUES Upon successful completion, the t_open function returns a file descrip- tor, a nonnegative integer. Otherwise, a value of -1 is returned and t_errno is set to indicate the error. ERRORS If the t_open() function fails, t_errno may be set to one of the fol- lowing values: An invalid flag is specified. Invalid transport provider name. A system error occurred during execution of this func- tion. This error indicates that a communication problem has been de- tected between XTI and the transport provider for which there is no other suitable XTI(t_errno). RELATED INFORMATION Functions: open(2) Standards: standards(5) delim off t_open(3)