$NetBSD: patch-ab,v 1.1 2004/09/18 12:47:33 uebayasi Exp $

--- support/ipfilter.c.orig	2003-02-20 07:30:26.000000000 +0900
+++ support/ipfilter.c
@@ -55,6 +55,13 @@ get_realdst(fd, laddrp, faddrp, np)
   np->nl_outip    = faddrp->sin_addr;
   np->nl_flags    = IPN_TCP;
 
+#ifndef IPL_NAT
+# ifdef IPL_NAME
+#  define IPL_NAT IPL_NAME
+# else
+#  error Neither IPL_NAT nor IPL_NAME undefined
+# endif
+#endif
   if ((natfd = open(IPL_NAT, O_RDONLY)) < 0) {
     perror("open");
     return(0);