If available, take UUID from smbios.system.uuid, if not fall back to

software-generated UUID. Store the result in /etc/hostid and use it in
the future. Perform simple UUID format check, as there is a lot of
hardware with broken UUIDs. The check should be improved to also eliminate
fake UUIDs like 00000000-0000-0000-0000-000000000000.

Requested by:	many

etc/rc.d/hostid

@@ -54,9 +54,26 @@ hostid_set()
 	${SYSCTL_W} kern.hostid=${id} >/dev/null
 }
 
+hostid_hardware()
+{
+	uuid=`kenv smbios.system.uuid 2>/dev/null`
+	x="[0-9a-zA-Z]"
+	y=$x$x$x$x
+	case "${uuid}" in
+	$y$y-$y-$y-$y-$y$y$y)
+		echo "${uuid}"
+		;;
+	esac
+}
+
 hostid_reset()
 {
-	uuid=`uuidgen`
+	# First look for UUID in hardware.
+	uuid=`hostid_hardware`
+	if [ -z ${uuid} ]; then
+		# If not found, fall back to software-generated UUID.
+		uuid=`uuidgen`
+	fi
 	# Store newly generated UUID in ${hostid_file}.
 	echo $uuid > ${hostid_file}
 	if [ $? -ne 0 ]; then