void channel_register_cleanup(int, channel_callback_fn *, int);
void channel_register_open_confirm(int, channel_callback_fn *, void *);
void channel_register_filter(int, channel_infilter_fn *,
void channel_register_cleanup(int, channel_callback_fn *, int);
void channel_register_open_confirm(int, channel_callback_fn *, void *);
void channel_register_filter(int, channel_infilter_fn *,