ipf_matchtag
if (ipf_matchtag(&fr->fr_nattag, fin->fin_nattag) == 0)
extern int ipf_matchtag(ipftag_t *, ipftag_t *);
!ipf_matchtag(&np->in_tag, &fr->fr_nattag))
!ipf_matchtag(&np->in_tag, &fr->fr_nattag))
if (ipf_matchtag(&fr->fr_nattag, fin->fin_nattag)!=0) {