nbd_set_request_extended_headers3

Usage

 #include <libnbd.h>
 int nbd_set_request_extended_headers (
       struct nbd_handle *h, bool request
     );

Overview

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