nbd_set_tls_priority(3)

NAME
nbd_set_tls_priority - set the TLS priority string

SYNOPSIS
 #include <libnbd.h>

 int nbd_set_tls_priority (
       struct nbd_handle *h, const char *priority
     );

DESCRIPTION
Set the TLS priority string. This controls which ciphers, key exchange methods and MACs are used and in what order. See "Priority strings" in the GnuTLS manual

The default is picked at compile time, either using "./configure --with-tls-priority=PRIORITY" or if that was not set then "NORMAL".

It is not recommended to change this unless you know what you are doing. It may be dangerous to set this from an untrusted source, since it may allow you to read some local configuration files, and possibly downgrade TLS security.

This function may be called regardless of whether TLS is supported, but will have no effect unless nbd_set_tls(3) is also used to request or require TLS.

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", "priority". For more information see "Non-NULL parameters" in libnbd(3).

HANDLE STATE
nbd_set_tls_priority 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 1.24.

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_TLS_PRIORITY 1

SEE ALSO
nbd_create(3), nbd_get_tls_priority(3), nbd_set_tls(3), nbd_set_uri_allow_tls_priority(3), libnbd(3), https://gnutls.org/manual/html_node/Priority-Strings.html.

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