+/* Returns the "typical" length of a match for 'protocol', for use in
+ * estimating space to preallocate. */
+int
+ofputil_match_typical_len(enum ofputil_protocol protocol)
+{
+ switch (protocol) {
+ case OFPUTIL_P_OF10_STD:
+ case OFPUTIL_P_OF10_STD_TID:
+ return sizeof(struct ofp10_match);
+
+ case OFPUTIL_P_OF10_NXM:
+ case OFPUTIL_P_OF10_NXM_TID:
+ return NXM_TYPICAL_LEN;
+
+ case OFPUTIL_P_OF11_STD:
+ return sizeof(struct ofp11_match);
+
+ case OFPUTIL_P_OF12_OXM:
+ case OFPUTIL_P_OF13_OXM:
+ return NXM_TYPICAL_LEN;
+
+ default:
+ NOT_REACHED();
+ }
+}
+
+/* Appends to 'b' an struct ofp11_match_header followed by a match that
+ * expresses 'match' properly for 'protocol', plus enough zero bytes to pad the
+ * data appended out to a multiple of 8. 'protocol' must be one that is usable
+ * in OpenFlow 1.1 or later.
+ *
+ * This function can cause 'b''s data to be reallocated.
+ *
+ * Returns the number of bytes appended to 'b', excluding the padding. Never
+ * returns zero. */
+int
+ofputil_put_ofp11_match(struct ofpbuf *b, const struct match *match,
+ enum ofputil_protocol protocol)
+{
+ switch (protocol) {
+ case OFPUTIL_P_OF10_STD:
+ case OFPUTIL_P_OF10_STD_TID:
+ case OFPUTIL_P_OF10_NXM:
+ case OFPUTIL_P_OF10_NXM_TID:
+ NOT_REACHED();
+
+ case OFPUTIL_P_OF11_STD: {
+ struct ofp11_match *om;
+
+ /* Make sure that no padding is needed. */
+ BUILD_ASSERT_DECL(sizeof *om % 8 == 0);
+
+ om = ofpbuf_put_uninit(b, sizeof *om);
+ ofputil_match_to_ofp11_match(match, om);
+ return sizeof *om;
+ }
+
+ case OFPUTIL_P_OF12_OXM:
+ case OFPUTIL_P_OF13_OXM:
+ return oxm_put_match(b, match);
+ }
+
+ NOT_REACHED();
+}
+