---
name: "nbd_set_uri_allow_tls"
section: "3"
platform: "linux"
package: "libnbd"
version: "1.24.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/nbd_set_uri_allow_tls"
---

# nbd\_set\_uri\_allow\_tls(3)

set the allowed TLS settings in NBD URIs

## NAME

nbd\_set\_uri\_allow\_tls - set the allowed TLS settings in NBD URIs

## SYNOPSIS

```
 #include <libnbd.h>
 int nbd_set_uri_allow_tls (
       struct nbd_handle *h, int tls
     );
```

## DESCRIPTION

Set which TLS settings are allowed to appear in NBD URIs. The default is to allow either non-TLS or TLS URIs.

The `"tls"` parameter can be:

- "LIBNBD\_TLS\_DISABLE"

  TLS URIs are not permitted, ie. a URI such as `"nbds://..."` will be rejected.

- "LIBNBD\_TLS\_ALLOW"

  This is the default.  TLS may be used or not, depending on whether the URI uses `"nbds"` or `"nbd"`.

- "LIBNBD\_TLS\_REQUIRE"

  TLS URIs are required.  All URIs must use `"nbds"`.

## RETURN VALUE

If the call is successful the function returns `0`.

## ERRORS

On error `-1` is returned.

Refer to "ERROR HANDLING" in [**libnbd**(3)](/libnbd/3.md) 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)](/libnbd/3.md).

## HANDLE STATE

nbd\_set\_uri\_allow\_tls 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 1.2.

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_URI_ALLOW_TLS 1
```

## SEE ALSO

[**nbd\_connect\_uri**(3)](/nbd_connect_uri/3.md), [**nbd\_create**(3)](/nbd_create/3.md), [**nbd\_set\_uri\_allow\_transports**(3)](/nbd_set_uri_allow_transports/3.md), [**libnbd**(3)](/libnbd/3.md).

## 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