diff -ur tcng.orig/tcsim/setup.ulib tcng/tcsim/setup.ulib
--- tcng.orig/tcsim/setup.ulib	2003-01-14 07:25:05.000000000 -0800
+++ tcng/tcsim/setup.ulib	2003-12-17 02:03:06.000000000 -0800
@@ -213,4 +213,7 @@
     perl -pi -e 's/exit\(0\);/return 0;/;' iproute2/tc/$n
 done
 
 touch .ready
+# Sometimes 'offsetof' is NOT defined, and we need to import it
+sed -i iproute2/tc/tc_qdisc.c -e '1i#include <stddef.h>'
+