TCP程序

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mcpc|

楼主 | 2007-4-18 22:06 | 只看该作者回帖奖励

|倒序浏览 |阅读模式

TCP, ip, se, ST, AD

void tcp_send(UINT flags, UINT hdr_len, UCHAR nr)
{
   ULONG idata sum, dest;
      UINT idata result;
   UCHAR xdata * outbuf;
   TCP_HEADER xdata * tcp;
   IP_HEADER xdata * ip;

   outbuf = outbuf1;

   tcp = (TCP_HEADER xdata *)(outbuf + 34);
   ip = (IP_HEADER xdata *)(outbuf + 14);

      if (nr == NO_CONNECTION)
   {
      tcp->source_port = HTTP_PORT;
      tcp->dest_port = sender_tcpport;
      tcp->sequence = 0;
      tcp->ack_number = 0;
      dest = sender_ipaddr;
   }
   else if (nr < 5)
   {
      // This message is to connected port
      tcp->source_port = HTTP_PORT;
      tcp->dest_port = conxn[nr].port;
      tcp->sequence = conxn[nr].my_sequence;
      tcp->ack_number = conxn[nr].his_sequence;
      dest = conxn[nr].ipaddr;
   }
   else
   {

        return;
    }

   tcp->flags = (hdr_len << 10) | flags;  //?????????????

   tcp->window = 1024;
   tcp->checksum = 0;
   tcp->urgent_ptr = 0;


   if (hdr_len == 28)
   {
      memcpy(&tcp->options, opt, 8);
   }


    ip->dest_ipaddr = dest;
    ip->source_ipaddr = my_ipaddr;

    sum = (ULONG)cksum(outbuf + 26, 8 + hdr_len);

    sum += (ULONG)0x0006;
    sum += (ULONG)hdr_len;

    result = (UINT)(sum + (sum >> 16));
    tcp->checksum = ~result;

    ip_send(outbuf, dest, TCP_TYPE, hdr_len);


   conxn[nr].timer = TCP_TIMEOUT;
}
我觉得这个程序没有把TCP信息封装到IP层去，不知道正确与否,请大家指正

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