--- zzzz-none-000/linux-4.4.60/include/net/ip.h	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-7490-727/linux-4.4.60/include/net/ip.h	2021-02-04 17:41:59.000000000 +0000
@@ -240,6 +240,9 @@
 }
 #endif
 
+/* From ip_forward.c */
+extern int sysctl_ip_use_legacy_tos;
+
 /* From inetpeer.c */
 extern int inet_peer_threshold;
 extern int inet_peer_minttl;