diff --git a/sys/net/ethernet.h b/sys/net/ethernet.h
--- a/sys/net/ethernet.h
+++ b/sys/net/ethernet.h
@@ -447,6 +447,7 @@
 #ifdef _KERNEL
 
 #include <sys/_eventhandler.h>
+#include <sys/systm.h>
 
 struct ifnet;
 struct mbuf;
@@ -479,10 +480,18 @@
 
 static __inline struct mbuf *ether_vlanencap(struct mbuf *m, uint16_t tag)
 {
-
 	return ether_vlanencap_proto(m, tag, ETHERTYPE_VLAN);
 }
 
+/* Create an ether_addr from an array of u_char (or uint8_t). */
+__nodiscard static __inline __unused struct ether_addr
+make_ether_addr(const u_char *__octets)
+{
+	struct ether_addr __ret;
+	memcpy(&__ret.octet[0], __octets, ETHER_ADDR_LEN);
+	return (__ret);
+}
+
 /* new ethernet interface attached event */
 typedef void (*ether_ifattach_event_handler_t)(void *, struct ifnet *);
 EVENTHANDLER_DECLARE(ether_ifattach_event, ether_ifattach_event_handler_t);