t_optmgmt(3N)

NAME
     t_optmgmt - manage options for a transport endpoint

SYNOPSIS
     #ifdef _XOPEN_SOURCE
     #include <xti.h>
     #else
     #include <tiuser.h>
     #endif

     int t_optmgmt (int fd, struct t_optmgmt *req, struct t_optmgmt *ret);

DESCRIPTION
     The t_optmgmt function enables a transport user to retrieve, verify, or
     negotiate protocol options with the transport provider.  fd identifies a
     bound transport endpoint.

     The req and ret arguments point to a t_optmgmt structure containing the
     following members:

          struct netbuf opt;
          long flags;

     The opt field identifies protocol options and the flags field is used to
     specify the action to take with those options.

     The options are represented by a netbuf [see intro(3N); also for len,
     buf, and maxlen] structure in a manner similar to the address in t_bind.
     req is used to request a specific action of the provider and to send
     options to the provider.  len specifies the number of bytes in the
     options, buf points to the options buffer, and maxlen has no meaning for
     the req argument.  The transport provider may return options and flag
     values to the user through ret.  For ret, maxlen specifies the maximum
     size of the options buffer and buf points to the buffer where the options
     are to be placed.  On return, len specifies the number of bytes of
     options returned.  maxlen has no meaning for the req argument, but must
     be set in the ret argument to specify the maximum number of bytes the
     options buffer can hold.  The actual structure and content of the options
     is imposed by the transport provider.

     The flags field of req can specify one of the following actions:

     T_NEGOTIATE    This action enables the user to negotiate the values of
                    the options specified in req with the transport provider.
                    The provider will evaluate the requested options and
                    negotiate the values, returning the negotiated values
                    through ret.

     T_CHECK        This action enables the user to verify whether the options
                    specified in req are supported by the transport provider.
                    On return, the flags field of ret will have either
                    T_SUCCESS or T_FAILURE set to indicate to the user whether
                    the options are supported.  These flags are only
                    meaningful for the T_CHECK request.

     T_DEFAULT      This action enables a user to retrieve the default options
                    supported by the transport provider into the opt field of
                    ret.  In req, the len field of opt must be zero and the
                    buf field may be NULL.

     T_CURRENT      If _XOPEN_SOURCE is defined, then this flag is supported.
                    This action enables the transport user to retrieve the
                    currently effective option values.  The user specifies the
                    options of interest in req->opt.buf.  The option values
                    are irrevelant and will be ignored; it is sufficient to
                    specify the t_opthdr part of an option only.  The
                    currently effective values are then returned in ret-
                    >opt.buf.

     If issued as part of the connectionless-mode service, t_optmgmt may block
     due to flow control constraints.  The function will not complete until
     the transport provider has processed all previously sent data units.

     This function resides within both the X/Open compliant libxnet and the
     SVR4 compliant libnsl Network Services libraries.  Network Services
     applications which require X/Open compliance must link-load with -lxnet.
     Network Services applications which require SVR4 compliance must link-
     load with -lnsl.

     On failure, t_errno may be set to one of the following:

     TBADF               The specified file descriptor does not refer to a
                         transport endpoint.

     TOUTSTATE           The function was issued in the wrong sequence.

     TACCES              The user does not have permission to negotiate the
                         specified options.

     TBADOPT             The specified protocol options were in an incorrect
                         format or contained illegal information.

     TBADFLAG            An invalid flag was specified.

     TBUFOVFLW           There are two different conditions in which TBUFOVFLW
                         will be returned.  If _XOPEN_SOURCE is defined and
                         the number of bytes allocated for incoming data is
                         greater than zero and is not sufficient to store the
                         data.  If _XOPEN_SOURCE is not defined and the number
                         of bytes allocated for incoming data is not
                         sufficient to store the data.  The information to be
                         returned in ret will be discarded.

     TSYSERR             A system error has occurred during execution of this
                         function.

SEE ALSO
     intro(3N), t_accept(3N), t_alloc(3N), t_connect(3N), t_getinfo(3N),
     t_listen(3N), t_open(3N), t_rcvconnect(3N)

DIAGNOSTICS
     t_optmgmt returns 0 on success and -1 on failure and t_errno is set to
     indicate the error.