struct cls_rule *);
void mf_set_flow_value(const struct mf_field *, const union mf_value *value,
struct flow *);
+bool mf_is_zero(const struct mf_field *, const struct flow *);
void mf_get(const struct mf_field *, const struct cls_rule *,
union mf_value *value, union mf_value *mask);