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

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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](#RETURN_VALUE)

If the call is successful the function returns 0.

# [ERRORS](#ERRORS)

On error -1 is returned.

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

# [HANDLE STATE](#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](#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](#SEE_ALSO)

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

# [AUTHORS](#AUTHORS)

Eric Blake

Richard W.M. Jones

# [COPYRIGHT](#COPYRIGHT)

Copyright Red Hat

# [LICENSE](#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

2026-10-11 libnbd-1.25.7

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Document: nbd_set_uri_allow_tls(3) from libnbd 1.25.7-r3 (Chainguard OS)