+ flow_extract_l3_onwards(packet, flow, flow->dl_type);
+}
+
+/* Initializes l3 and higher 'flow' members from 'packet'
+ *
+ * This should be called by or after flow_extract()
+ *
+ * Initializes 'packet' header pointers as follows:
+ *
+ * - packet->l4 to just past the IPv4 header, if one is present and has a
+ * correct length, and otherwise NULL.
+ *
+ * - packet->l7 to just past the TCP or UDP or ICMP header, if one is
+ * present and has a correct length, and otherwise NULL.
+ */
+void
+flow_extract_l3_onwards(struct ofpbuf *packet, struct flow *flow,
+ ovs_be16 dl_type)
+{
+ struct ofpbuf b;
+
+ ofpbuf_use_const(&b, packet->l3, packet->size -
+ (size_t)((char *)packet->l3 - (char *)packet->l2));
+
+ /* Network layer. */
+ if (dl_type == htons(ETH_TYPE_IP)) {