ov               1300 net/pf_norm.c  		u_int16_t	ov, nv;
ov               1302 net/pf_norm.c  		ov = *(u_int16_t *)(&th->th_ack + 1);
ov               1307 net/pf_norm.c  		th->th_sum = pf_cksum_fixup(th->th_sum, ov, nv, 0);