static struct netbuf *tcp_makepkt(struct connection *con,
                                  uint8 flags, uint16 window,
                                  int mss, int window_scale,
                                  int size, char *data)
{
  struct netbuf *pkt;
  struct tcp_header *tcphdr;
...
  pkt = kz_kmalloc(DEFAULT_NETBUF_SIZE);
  memset(pkt, 0, DEFAULT_NETBUF_SIZE);
  pkt->top = pkt->data + 64;      擪{64̈ʒuwƂŁCwb_}̂߂̋󂫂炩ߍĂ

  tcphdr = (struct tcp_header *)pkt->top;

  tcphdr->src_port   = hton2(con->src_port);  TCPwb_̍쐬
  tcphdr->dst_port   = hton2(con->dst_port);  
...
  if (data)
    memcpy((char *)tcphdr + hdrlen, data, size); f[^Rs[
...
