ofp-prop: New function ofpprop_put_zeros().

This will have additional users in later commits.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Jarno Rajahalme <jarno@ovn.org>

lib/ofp-prop.c

@@ -275,6 +275,28 @@ ofpprop_put(struct ofpbuf *msg, uint64_t type, const void *value, size_t len)
     ofpprop_end(msg, start_ofs);
 }
 
+/* Adds a property with the given 'type' to 'msg', consisting of a struct
+ * ofp_prop_header or ofp_prop_experimenter followed by enough zero bytes to
+ * total 'len' bytes, followed by padding to bring the property up to a
+ * multiple of 8 bytes.  Returns the property header. */
+void *
+ofpprop_put_zeros(struct ofpbuf *msg, uint64_t type, size_t len)
+{
+    void *header = ofpbuf_put_zeros(msg, ROUND_UP(len, 8));
+    if (!ofpprop_is_experimenter(type)) {
+        struct ofp_prop_header *oph = header;
+        oph->type = htons(type);
+        oph->len = htons(len);
+    } else {
+        struct ofp_prop_experimenter *ope = header;
+        ope->type = htons(0xffff);
+        ope->len = htons(len);
+        ope->experimenter = htonl(ofpprop_type_to_exp_id(type));
+        ope->exp_type = htonl(ofpprop_type_to_exp_type(type));
+    }
+    return header;
+}
+
 /* Adds a property with the given 'type' and 16-bit 'value' to 'msg'. */
 void
 ofpprop_put_be16(struct ofpbuf *msg, uint64_t type, ovs_be16 value)

lib/ofp-prop.h

@@ -89,6 +89,7 @@ enum ofperr ofpprop_parse_uuid(const struct ofpbuf *, struct uuid *);
 /* Serializing properties. */
 void ofpprop_put(struct ofpbuf *, uint64_t type,
                  const void *value, size_t len);
+void *ofpprop_put_zeros(struct ofpbuf *, uint64_t type, size_t len);
 void ofpprop_put_be16(struct ofpbuf *, uint64_t type, ovs_be16 value);
 void ofpprop_put_be32(struct ofpbuf *, uint64_t type, ovs_be32 value);
 void ofpprop_put_be64(struct ofpbuf *, uint64_t type, ovs_be64 value);

lib/ofp-util.c

@@ -3868,9 +3868,7 @@ ofputil_put_ofp14_port(const struct ofputil_phy_port *pp,
     op->config = htonl(pp->config & OFPPC11_ALL);
     op->state = htonl(pp->state & OFPPS11_ALL);
 
-    eth = ofpbuf_put_zeros(b, sizeof *eth);
+    eth = ofpprop_put_zeros(b, OFPPDPT14_ETHERNET, sizeof *eth);
-    eth->type = htons(OFPPDPT14_ETHERNET);
-    eth->length = htons(sizeof *eth);
     eth->curr = netdev_port_features_to_ofp11(pp->curr);
     eth->advertised = netdev_port_features_to_ofp11(pp->advertised);
     eth->supported = netdev_port_features_to_ofp11(pp->supported);
@@ -5013,9 +5011,7 @@ ofputil_append_table_desc_reply(const struct ofputil_table_desc *td,
     if (td->vacancy == OFPUTIL_TABLE_VACANCY_ON) {
         struct ofp14_table_mod_prop_vacancy *otv;
 
-        otv = ofpbuf_put_zeros(reply, sizeof *otv);
+        otv = ofpprop_put_zeros(reply, OFPTMPT14_VACANCY, sizeof *otv);
-        otv->type = htons(OFPTMPT14_VACANCY);
-        otv->length = htons(sizeof *otv);
         otv->vacancy_down = td->table_vacancy.vacancy_down;
         otv->vacancy_up = td->table_vacancy.vacancy_up;
         otv->vacancy = td->table_vacancy.vacancy;
@@ -5279,7 +5275,6 @@ ofputil_encode_table_mod(const struct ofputil_table_mod *tm,
     case OFP14_VERSION:
     case OFP15_VERSION: {
         struct ofp14_table_mod *otm;
-        struct ofp14_table_mod_prop_vacancy *otv;
 
         b = ofpraw_alloc(OFPRAW_OFPT14_TABLE_MOD, ofp_version, 0);
         otm = ofpbuf_put_zeros(b, sizeof *otm);
@@ -5291,9 +5286,9 @@ ofputil_encode_table_mod(const struct ofputil_table_mod *tm,
             ofpprop_put_u32(b, OFPTMPT14_EVICTION, tm->eviction_flags);
         }
         if (tm->vacancy == OFPUTIL_TABLE_VACANCY_ON) {
-            otv = ofpbuf_put_zeros(b, sizeof *otv);
+            struct ofp14_table_mod_prop_vacancy *otv;
-            otv->type = htons(OFPTMPT14_VACANCY);
+
-            otv->length = htons(sizeof *otv);
+            otv = ofpprop_put_zeros(b, OFPTMPT14_VACANCY, sizeof *otv);
             otv->vacancy_down = tm->table_vacancy.vacancy_down;
             otv->vacancy_up = tm->table_vacancy.vacancy_up;
         }
@@ -6961,10 +6956,7 @@ ofputil_append_ofp14_port_stats(const struct ofputil_port_stats *ops,
     ps14->rx_errors = htonll(ops->stats.rx_errors);
     ps14->tx_errors = htonll(ops->stats.tx_errors);
 
-    eth = ofpbuf_put_uninit(reply, sizeof *eth);
+    eth = ofpprop_put_zeros(reply, OFPPSPT14_ETHERNET, sizeof *eth);
-    eth->type = htons(OFPPSPT14_ETHERNET);
-    eth->length = htons(sizeof *eth);
-    memset(eth->pad, 0, sizeof eth->pad);
     eth->rx_frame_err = htonll(ops->stats.rx_frame_errors);
     eth->rx_over_err = htonll(ops->stats.rx_over_errors);
     eth->rx_crc_err = htonll(ops->stats.rx_crc_errors);