-

fn remote_df2(SshInfo { user, pass, host, dir }: SshInfo) -> Result<Bytes> {
    let (tcp, sess) = ssh(user, pass, host)?;
    let sftp = sess.sftp()?;
    let file = sftp.open(Path::new(dir))?;
    unsafe {
        let mut handle = mem::transmute_copy::<ssh2::File, *mut LIBSSH2_SFTP_HANDLE>(&file);
        let mut attrs: LIBSSH2_SFTP_STATVFS = mem::zeroed();
        sftp.rc(libssh2_sftp_fstatvfs(handle, &mut attrs))?;
        Ok(Bytes(attrs.f_bavail * attrs.f_bsize))
    }
}