NAME

       nbd_opt_structured_reply - request the server to enable structured replies

SYNOPSIS

        #include <libnbd.h>

        int nbd_opt_structured_reply (
              struct nbd_handle *h
            );

DESCRIPTION

       Request that the server use structured replies, by sending "NBD_OPT_STRUCTURED_REPLY".
       This can only be used if nbd_set_opt_mode(3) enabled option mode; furthermore, libnbd
       defaults to automatically requesting this unless you use
       nbd_set_request_structured_replies(3) prior to connecting.  This function is mainly useful
       for integration testing of corner cases in server handling.

       This function returns true if the server replies with success, false if the server replies
       with an error, and fails only if the server does not reply (such as for a loss of
       connection).  Note that some servers fail a second request as redundant; libnbd assumes
       that once one request has succeeded, then structured replies are supported (as visible by
       nbd_get_structured_replies_negotiated(3)) regardless if later calls to this function
       return false.

RETURN VALUE

       This call returns a boolean value.

ERRORS

       On error "-1" is returned.

       Refer to "ERROR HANDLING" in libnbd(3) for how to get further details of the error.

       The following parameters must not be NULL: "h".  For more information see "Non-NULL
       parameters" in libnbd(3).

HANDLE STATE

       The handle must be negotiating, otherwise this call will return an error.

VERSION

       This function first appeared in libnbd 1.16.

       If you need to test if this function is available at compile time check if the following
       macro is defined:

        #define LIBNBD_HAVE_NBD_OPT_STRUCTURED_REPLY 1

SEE ALSO

       nbd_aio_opt_structured_reply(3), nbd_create(3), nbd_get_structured_replies_negotiated(3),
       nbd_opt_go(3), nbd_set_opt_mode(3), nbd_set_request_structured_replies(3), libnbd(3).

AUTHORS

       Eric Blake

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

       This library is free software; you can redistribute it and/or modify it under the terms of
       the GNU Lesser General Public License as published by the Free Software Foundation; either
       version 2 of the License, or (at your option) any later version.

       This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU Lesser General Public License for more details.

       You should have received a copy of the GNU Lesser General Public License along with this
       library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
       Floor, Boston, MA 02110-1301 USA