In some email I received from itojun@iijlab.net, sie wrote:
> 
> >> 	please notice that sys/netinet6 uses sys/netinet6/ip6protosw.h.
> >hmmm...is struct ip6protosw any different to protosw besides
> >pr_ctlinput and pr_ctloutput ?  Maybe these functions should
> >now be using stdarg (as do pr_input/pr_output) so that ip6protosw
> >can be eliminated ?
> 
> 	we can't.  return value is different.

void (protosw) vs int (ip6protosw)

Maybe the older ipv4 functions should be upgraded to return int then ?

Darren