NAME

       nbd_get_tls_negotiated - find out if TLS was negotiated on a connection

SYNOPSIS

        #include <libnbd.h>

        int nbd_get_tls_negotiated (
              struct nbd_handle *h
            );

DESCRIPTION

       After connecting you may call this to find out if the connection is using TLS.

       This is normally useful only if you set the TLS request mode to "LIBNBD_TLS_ALLOW" (see
       nbd_set_tls(3)), because in this mode we try to use TLS but fall back to unencrypted if it
       was not available.  This function will tell you if TLS was negotiated or not.

       In "LIBNBD_TLS_REQUIRE" mode (the most secure) 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.

RETURN VALUE

       This call returns a boolean value.

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).

HANDLE STATE

       The handle must be negotiating, or connected with the server, or shut down, otherwise this
       call will return an 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

       nbd_create(3), nbd_get_tls(3), nbd_opt_starttls(3), nbd_set_tls(3), libnbd(3).

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