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