int (*port_query_by_number)(const struct dpif *dpif, uint32_t port_no,
struct dpif_port *port);
int (*port_query_by_name)(const struct dpif *dpif, const char *devname,
int (*port_query_by_number)(const struct dpif *dpif, uint32_t port_no,
struct dpif_port *port);
int (*port_query_by_name)(const struct dpif *dpif, const char *devname,