copyexthdr
static int copyexthdr (void *, struct mbuf **);
if ((error = copyexthdr(opt->ip6po_hbh, &exthdrs.ip6e_hbh)))
if ((error = copyexthdr(opt->ip6po_dest1, &exthdrs.ip6e_dest1)))
if ((error = copyexthdr(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr)))
if ((error = copyexthdr(opt->ip6po_dest2, &exthdrs.ip6e_dest2)))