In some email I received from itojun@iijlab.net, sie wrote:
> 
> 
> >   Below I've attached some patches which I've put together which provide
> >support for per-protocol filtering.  Whilst there were some criticisms
> >about putting things in header files, I stuck with the changes I made
> >because it seemed wrong that these networking files had an abitrary list
> >of externs.
> 
> 	The patch does not compile if INET6 is defined, due to the lack of
> 	extern def for ip6_protox[].  could you define it somewhere?
> 	(or is it just diff is missing from the email?)

Ack.  I notice there was no patch for in6.h :-(  You'll find it below.
I've been working with a NetBSD snap that is using KAME 19990705 so the
diffs required some work (and hence I lost a file) to get them to be
good with -current.

Darren

Index: in6.h
===================================================================
RCS file: /cvsroot/syssrc/sys/netinet6/in6.h,v
retrieving revision 1.7
diff -c -r1.7 in6.h
*** in6.h	1999/12/13 15:17:22	1.7
--- in6.h	1999/12/21 12:02:44
***************
*** 602,607 ****
--- 602,608 ----
  struct	in6_ifaddr *in6_ifawithscope __P((struct ifnet *, struct in6_addr *));
  struct	in6_ifaddr *in6_ifawithifp __P((struct ifnet *, struct in6_addr *));
  extern void in6_if_up __P((struct ifnet *));
+ extern u_char ip6_protox[];
  #ifdef MAPPED_ADDR_ENABLED
  struct sockaddr;