=head1 NAME

nbd_set_tls_hostname - set the TLS hostname

=head1 SYNOPSIS

 #include <libnbd.h>

 int nbd_set_tls_hostname (
       struct nbd_handle *h, const char *hostname
     );

=head1 DESCRIPTION

Set the TLS server hostname.  This is used in preference to the
hostname supplied when connecting (eg. through L<nbd_connect_tcp(3)>),
or when there is no explicit hostname at all (L<nbd_connect_unix(3)>).
It can be useful when you are connecting to a proxy which is forwarding
the data to the final server, to specify the name of the final server
so that the server's certificate can be checked.

This function may be called regardless of whether TLS is
supported, but will have no effect unless L<nbd_set_tls(3)>
is also used to request or require TLS.

=head1 RETURN VALUE

If the call is successful the function returns C<0>.

=head1 ERRORS

On error C<-1> is returned.

Refer to L<libnbd(3)/ERROR HANDLING>
for how to get further details of the error.

The following parameters must not be NULL: C<h>, C<hostname>.
For more information see L<libnbd(3)/Non-NULL parameters>.

=head1 HANDLE STATE

nbd_set_tls_hostname
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                │
 └─────────────────────────────────────┴─────────────────────────┘

=head1 VERSION

This function first appeared in libnbd 1.22.

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_TLS_HOSTNAME 1

=head1 SEE ALSO

L<nbd_connect_tcp(3)>,
L<nbd_connect_unix(3)>,
L<nbd_create(3)>,
L<nbd_set_tls(3)>,
L<nbd_set_tls_username(3)>,
L<libnbd(3)>.

=head1 AUTHORS

Eric Blake

Richard W.M. Jones

=head1 COPYRIGHT

Copyright Red Hat
