nbd\_get\_handshake\_flags(3) LIBNBD nbd\_get\_handshake\_flags(3)

# [NAME](#NAME)

nbd\_get\_handshake\_flags - see which handshake flags are supported

# [SYNOPSIS](#SYNOPSIS)

```
 #include <libnbd.h>
 uint32_t nbd_get_handshake_flags (
            struct nbd_handle *h
          );
```

# [DESCRIPTION](#DESCRIPTION)

Return the state of the handshake flags on this handle. When the handle has not yet completed a connection (see [**nbd\_aio\_is\_created**(3)](/man/os/libnbd/nbd_aio_is_created.3)), this returns the flags that the client is willing to use, provided the server also advertises those flags. After the connection is ready (see [**nbd\_aio\_is\_ready**(3)](/man/os/libnbd/nbd_aio_is_ready.3)), this returns the flags that were actually agreed on between the server and client. If the NBD protocol defines new handshake flags, then the return value from a newer library version may include bits that were undefined at the time of compilation.

# [RETURN VALUE](#RETURN_VALUE)

This call returns a bitmask of LIBNBD\_HANDSHAKE\_FLAG\_* values.

# [ERRORS](#ERRORS)

This function does not fail.

The following parameters must not be NULL: "h". For more information see "Non-NULL parameters" in [**libnbd**(3)](/man/os/libnbd/libnbd.3).

# [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_GET_HANDSHAKE_FLAGS 1
```

# [SEE ALSO](#SEE_ALSO)

[**nbd\_aio\_is\_created**(3)](/man/os/libnbd/nbd_aio_is_created.3), [**nbd\_aio\_is\_ready**(3)](/man/os/libnbd/nbd_aio_is_ready.3), [**nbd\_create**(3)](/man/os/libnbd/nbd_create.3), [**nbd\_get\_protocol**(3)](/man/os/libnbd/nbd_get_protocol.3), [**nbd\_set\_handshake\_flags**(3)](/man/os/libnbd/nbd_set_handshake_flags.3), [**nbd\_set\_strict\_mode**(3)](/man/os/libnbd/nbd_set_strict_mode.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

2026-09-11 libnbd-1.25.7

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Document: nbd_get_handshake_flags(3) from libnbd 1.25.7-r2 (Chainguard OS)