fr_fragderef
fr_fragderef((ipfr_t **)datap, &ifs->ifs_ipf_frag, ifs);
fr_fragderef((ipfr_t **)datap,
fr_fragderef(&frag, lock, ifs);
extern void fr_fragderef __P((ipfr_t **, ipfrwlock_t *, ipf_stack_t *));