fdpass_send
if (!fdpass_send(fdpass_peer, FDPASS_OPEN_SND, num, mode, -1))
if (!fdpass_send(fdpass_peer, FDPASS_OPEN_MIDI, num, mode, -1))
if (!fdpass_send(fdpass_peer, FDPASS_OPEN_CTL, num, mode, -1))
fdpass_send(f, FDPASS_RETURN, 0, 0, fd);