th_reseqlen
i = phdr->th_seq + phdr->th_reseqlen - th->th_seq;
if (i < qhdr->th_reseqlen) {
qhdr->th_reseqlen -= i;
th->th_reseqlen = *tlen;
if (tp->t_state == TCPS_SYN_RECEIVED && q->tcpqe_tcp->th_reseqlen)
tp->rcv_nxt += q->tcpqe_tcp->th_reseqlen;