void *make_openflow_xid(size_t openflow_len, uint8_t type,
uint32_t xid, struct buffer **);
void update_openflow_length(struct buffer *);
+struct buffer *make_add_flow(const struct flow *, uint32_t buffer_id,
+ uint16_t max_idle, size_t n_actions);
struct buffer *make_add_simple_flow(const struct flow *,
uint32_t buffer_id, uint16_t out_port,
uint16_t max_idle);