+/* Sends 'request' followed by a barrier request to 'vconn', then blocks until
+ * it receives a reply to the barrier. If successful, stores the reply to
+ * 'request' in '*replyp', if one was received, and otherwise NULL, then
+ * returns 0. Otherwise returns a positive errno value, or EOF, and sets
+ * '*replyp' to null.
+ *
+ * This function is useful for sending an OpenFlow request that doesn't
+ * ordinarily include a reply but might report an error in special
+ * circumstances.
+ *
+ * 'request' is always destroyed, regardless of the return value. */
+int
+vconn_transact_noreply(struct vconn *vconn, struct ofpbuf *request,
+ struct ofpbuf **replyp)
+{
+ ovs_be32 request_xid;
+ ovs_be32 barrier_xid;
+ struct ofpbuf *barrier;
+ int error;
+
+ *replyp = NULL;
+
+ /* Send request. */
+ request_xid = ((struct ofp_header *) ofpbuf_data(request))->xid;
+ error = vconn_send_block(vconn, request);
+ if (error) {
+ ofpbuf_delete(request);
+ return error;
+ }
+
+ /* Send barrier. */
+ barrier = ofputil_encode_barrier_request(vconn_get_version(vconn));
+ barrier_xid = ((struct ofp_header *) ofpbuf_data(barrier))->xid;
+ error = vconn_send_block(vconn, barrier);
+ if (error) {
+ ofpbuf_delete(barrier);
+ return error;
+ }
+
+ for (;;) {
+ struct ofpbuf *msg;
+ ovs_be32 msg_xid;
+ int error;
+
+ error = vconn_recv_block(vconn, &msg);
+ if (error) {
+ ofpbuf_delete(*replyp);
+ *replyp = NULL;
+ return error;
+ }
+
+ msg_xid = ((struct ofp_header *) ofpbuf_data(msg))->xid;
+ if (msg_xid == request_xid) {
+ if (*replyp) {
+ VLOG_WARN_RL(&bad_ofmsg_rl, "%s: duplicate replies with "
+ "xid %08"PRIx32, vconn->name, ntohl(msg_xid));
+ ofpbuf_delete(*replyp);
+ }
+ *replyp = msg;
+ } else {
+ ofpbuf_delete(msg);
+ if (msg_xid == barrier_xid) {
+ return 0;
+ } else {
+ VLOG_DBG_RL(&bad_ofmsg_rl, "%s: reply with xid %08"PRIx32
+ " != expected %08"PRIx32" or %08"PRIx32,
+ vconn->name, ntohl(msg_xid),
+ ntohl(request_xid), ntohl(barrier_xid));
+ }
+ }
+ }
+}
+
+/* vconn_transact_noreply() for a list of "struct ofpbuf"s, sent one by one.
+ * All of the requests on 'requests' are always destroyed, regardless of the
+ * return value. */
+int
+vconn_transact_multiple_noreply(struct vconn *vconn, struct list *requests,
+ struct ofpbuf **replyp)
+{
+ struct ofpbuf *request, *next;
+
+ LIST_FOR_EACH_SAFE (request, next, list_node, requests) {
+ int error;
+
+ list_remove(&request->list_node);
+
+ error = vconn_transact_noreply(vconn, request, replyp);
+ if (error || *replyp) {
+ ofpbuf_list_delete(requests);
+ return error;
+ }
+ }
+
+ *replyp = NULL;
+ return 0;
+}
+