nbd_set_request_extended_headers - control use of extended headers

       Eric Blake

       Richard W.M. Jones

       Copyright Red Hat

       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.

       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).

       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                │
        └─────────────────────────────────────┴─────────────────────────┘

       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

libnbd-1.22.2                                      2025-06-16                nbd_set_request_extended_headers(3)

       nbd_set_request_extended_headers - control use of extended headers

       If the call is successful the function returns 0.

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).

        #include <libnbd.h>

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

       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