NAME

       nbd_set_request_extended_headers - control use of extended headers

SYNOPSIS

        #include <libnbd.h>

        int nbd_set_request_extended_headers (
              struct nbd_handle *h, bool request
            );

DESCRIPTION

       By default, libnbd tries to negotiate extended headers with the server, as this protocol
       extension permits the use of 64-bit zero, trim, and block status actions.  However, for
       integration testing, it can be useful to clear this flag rather than find a way to alter
       the server to fail the negotiation request.

       For backwards compatibility, the setting of this knob is ignored if
       nbd_set_request_structured_replies(3) is also set to false, since the use of extended
       headers implies structured replies.

RETURN VALUE

       If the call is successful the function returns 0.

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

       nbd_set_request_extended_headers can be called when the handle is in the following state:

        ┌─────────────────────────────────────┬─────────────────────────┐
        │ Handle created, before connecting   │ ✅ allowed              │
        │ Connecting                          │ ❌ error                │
        │ Connecting & handshaking (opt_mode) │ ❌ error                │
        │ Connected to the server             │ ❌ error                │
        │ Connection shut down                │ ❌ error                │
        │ Handle dead                         │ ❌ error                │
        └─────────────────────────────────────┴─────────────────────────┘

VERSION

       This function first appeared in libnbd 1.18.

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

        #define LIBNBD_HAVE_NBD_SET_REQUEST_EXTENDED_HEADERS 1

SEE ALSO

       nbd_block_status_64(3), nbd_cache(3), nbd_create(3),
       nbd_get_extended_headers_negotiated(3), nbd_get_request_extended_headers(3),
       nbd_opt_extended_headers(3), nbd_set_handshake_flags(3),
       nbd_set_request_structured_replies(3), nbd_set_strict_mode(3), nbd_trim(3), nbd_zero(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