icmp.c

DSP2407控制8019芯片实现的网页服务器

/*********************************************************************************
*  icmp.c	v1.00       icmp协议程序	                                         *
*  版权(c) 	2004-		北京百科融创科技有限公司		                         *
*  设计者：	赵治心																 *
*  邮箱：   [e-mail]								                     *
**********************************************************************************/
#include "stdio.h"
#include "tcp_ip.h"
#include "global.h"
#include "8019head.h"

void ping_send(UCHAR * inbuf, UCHAR *ipaddr, UINT len)
{
	int i;
   PING_HEADER * ping_in;
   PING_HEADER * ping_out;
   UCHAR * outbuf;
   outbuf=(UCHAR *)SendBuffer;          
   ping_in = (PING_HEADER *)(inbuf + 34);
 
   // Ping response message payload starts at offset 34
   ping_out = (PING_HEADER *)(outbuf + 34);

   ping_out->msg_type = 0;
   ping_out->msg_code = 0;
   ping_out->checksum[0] = 0;
   ping_out->checksum[1] = 0;
   ping_out->identifier[0] = ping_in->identifier[0];
   ping_out->identifier[1] = ping_in->identifier[1];
   ping_out->sequence[0] = ping_in->sequence[0];
   ping_out->sequence[1] = ping_in->sequence[1];
   
   for(i=0;i<len-8;i++)
   		*(outbuf+i+42)=*(inbuf+i+42);
         
   // Compute checksum over the ICMP header plus
	// optional data and insert complement
   i = ~cksum(outbuf + 34, len);
   ping_out->checksum[0] = (i&0xff00)>>8;
   ping_out->checksum[1] = i&0x00ff;

   ip_send(outbuf, ipaddr, ICMP_TYPE, len);
}


void icmp_rcve(UCHAR * inbuf, UINT len)
{
   IP_HEADER * ip;
   UCHAR msg_type;
   UINT temp;
   
   // Allow for 14 bytes eth header
   ip = (IP_HEADER *)(inbuf + 14);
	temp = cksum(inbuf + 34, len);
	
	if (temp != 0xFFFF)
      return;    
   // Switch on the message type
   msg_type = *(inbuf + 34);
   switch(msg_type)
   {
      case 3:
      break;

	   case 8:
     	 ping_send(inbuf, sed_desIPAddr, len); 
      break;

      default:
  	    break;
   }
}