typedef struct udi_xfer_constraints_s udi_xfer_constraints_t;
typedef void udi_buf_copy_call_t(udi_cb_t *gcb, udi_buf_t *new_dst_buf);
typedef void udi_buf_write_call_t(udi_cb_t *gcb, udi_buf_t *new_dst_buf);
typedef struct udi_xfer_constraints_s udi_xfer_constraints_t;
typedef void udi_buf_copy_call_t(udi_cb_t *gcb, udi_buf_t *new_dst_buf);
typedef void udi_buf_write_call_t(udi_cb_t *gcb, udi_buf_t *new_dst_buf);