t_optmgmt(3N)         (Networking Support Utilities)          t_optmgmt(3N)


   NAME
         toptmgmt - manage options for a transport endpoint

   SYNOPSIS
         #include <tiuser.h>

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

   DESCRIPTION
         The toptmgmt 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 toptmgmt 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(3); also for len,
         buf, and maxlen] structure in a manner similar to the address in
         tbind.  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:

         TNEGOTIATE    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.

         TCHECK        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 TSUCCESS or TFAILURE set to
                        indicate to the user whether the options are
                        supported.  These flags are only meaningful for the


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   t_optmgmt(3N)         (Networking Support Utilities)          t_optmgmt(3N)


                        TCHECK request.

         TDEFAULT      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.

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

         On failure, terrno 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]         The number of bytes allowed for an incoming
                             argument is not sufficient to store the value of
                             that argument.  The information to be returned in
                             ret will be discarded.

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

   SEE ALSO
         intro(3), tgetinfo(3N), topen(3N).
         Programmer's Guide: Networking Interfaces.

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










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