NAME

       nbd_aio_opt_starttls - request the server to initiate TLS

SYNOPSIS

        #include <libnbd.h>

        typedef struct {
          int (*callback) (void *user_data, int *error);
          void *user_data;
          void (*free) (void *user_data);
        } nbd_completion_callback;

        int nbd_aio_opt_starttls (
              struct nbd_handle *h,
              nbd_completion_callback completion_callback
            );

DESCRIPTION

       Request that the server initiate a secure TLS connection, by sending "NBD_OPT_STARTTLS".
       This behaves like the synchronous counterpart nbd_opt_starttls(3), except that it does not
       wait for the server's response.

       To determine when the request completes, wait for nbd_aio_is_connecting(3) to return
       false.  Or supply the optional "completion_callback" which will be invoked as described in
       "Completion callbacks" in libnbd(3), except that it is automatically retired regardless of
       return value.  Note that detecting whether the server returns an error (as is done by the
       return value of the synchronous counterpart) is only possible with a completion callback.

RETURN VALUE

       If the call is successful the function returns 0.

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, otherwise this call will return an error.

VERSION

       This function first appeared in libnbd 1.16.

       If you need to test if this function is available at compile time check if the following
       macro is defined:

        #define LIBNBD_HAVE_NBD_AIO_OPT_STARTTLS 1

SEE ALSO

       nbd_aio_is_connecting(3), nbd_create(3), nbd_opt_starttls(3), nbd_set_opt_mode(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