nbd_get_tls_negotiated(3)

📦
version 1.25.8 · 18 versions
, in centos-stream 10

hey bestie 💖 welcome to the nbd_get_tls_negotiated(3) page — this one lives in the LIBNBD manual, and it’s all about checking whether TLS actually got negotiated on a connection ✨

🎀 NAME 🎀

nbd_get_tls_negotiated — find out if TLS was negotiated on a connection. That’s the whole assignment, no cap 💅

✨ SYNOPSIS ✨

        #include <libnbd.h>

        int nbd_get_tls_negotiated (
              struct nbd_handle *h
            );

🦋 DESCRIPTION 🦋

After you’ve connected, you can call this to find out whether the connection is using TLS. It’s normally useful only if you set the TLS request mode to LIBNBD_TLS_ALLOW (peep nbd_set_tls(3)), because in that mode it tries to use TLS but falls back to unencrypted if TLS wasn’t available. This function tells you whether TLS was negotiated or not, periodt. 🔥

In LIBNBD_TLS_REQUIRE mode (the most secure one), the connection would have failed if TLS could not be negotiated. With LIBNBD_TLS_DISABLE mode, TLS is not tried automatically; but if the NBD server uses the less-common SELECTIVETLS mode, this function reports whether a manual nbd_opt_starttls(3) enabled TLS or if the connection is still plaintext. iykyk 💀

🌈 RETURN VALUE 🌈

This call returns a boolean value. That’s it, that’s the tea 🍓

🚨 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). Don’t pass a NULL handle, bestie — that’s not the vibe. 🙈

🦋 HANDLE STATE 🦋

nbd_get_tls_negotiated can be called when the handle is in these states:

  • Handle created, before connecting — ❌ error
  • Connecting — ❌ error
  • Connecting & handshaking (opt_mode) — ✅ allowed
  • Connected to the server — ✅ allowed
  • Connection shut down — ✅ allowed
  • 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_GET_TLS_NEGOTIATED 1

👑 SEE ALSO 👑

Go peek at these:

💅 AUTHORS 💅

  • Eric Blake
  • Richard W.M. Jones

Copyright Red Hat

💜 LICENSE 💜

Legal bestie moment: here’s the exact license text, no edits, because words matter. 🫶

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

okay bye bestie 💅 this page is from libnbd-1.25.8, dated 2026-10-13, and the footer name is nbd_get_tls_negotiated(3) 🫶

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