b->l4 = icmp = ofpbuf_put_zeros(b, sizeof *icmp);
icmp->icmp_type = ntohs(flow->tp_src);
icmp->icmp_code = ntohs(flow->tp_dst);
b->l4 = icmp = ofpbuf_put_zeros(b, sizeof *icmp);
icmp->icmp_type = ntohs(flow->tp_src);
icmp->icmp_code = ntohs(flow->tp_dst);