+/* Sets up the flow format for a vconn that will be used to modify the flow
+ * table. Returns the flow format used, after possibly adding an OpenFlow
+ * request to 'requests'.
+ *
+ * If 'preferred_flow_format' is -1, returns NXFF_OPENFLOW10 without modifying
+ * 'requests', since NXFF_OPENFLOW10 is the default flow format for any
+ * OpenFlow connection.
+ *
+ * If 'preferred_flow_format' is a specific format, adds a request to set that
+ * format to 'requests' and returns the format. */
+static enum nx_flow_format
+set_initial_format_for_flow_mod(struct list *requests)
+{
+ if (preferred_flow_format < 0) {
+ return NXFF_OPENFLOW10;
+ } else {
+ struct ofpbuf *sff;
+
+ sff = ofputil_make_set_flow_format(preferred_flow_format);
+ list_push_back(requests, &sff->list_node);
+ return preferred_flow_format;
+ }
+}
+
+/* Checks that 'flow_format' is acceptable as a flow format after a flow_mod
+ * operation, given the global 'preferred_flow_format'. */
+static void
+check_final_format_for_flow_mod(enum nx_flow_format flow_format)
+{
+ if (preferred_flow_format >= 0 && flow_format != preferred_flow_format) {
+ ovs_fatal(0, "flow cannot be expressed in flow format %s "
+ "(flow format %s or better is required)",
+ ofputil_flow_format_to_string(preferred_flow_format),
+ ofputil_flow_format_to_string(flow_format));
+ }
+}
+