/******************************************************************************
*
*   Name:           icmp.c
*
*   Description:    ICMP function
*
*   Copyright:      (c) 2005-2050    IC Plus Corp.
*                   All rights reserved.  By Chance
*
*******************************************************************************/
//20051021
#include <stdio.h>
#include <string.h>
#include "icmp.h"
/******************************************************************************
*
*  Function:    ICMP_Process
*
*  Description:  Handle ICMP packet for ping
*               
*  Parameters:  NONE
*               
*  Returns:     NONE
*               
*******************************************************************************/
void ICMP_Process()
{
	u16_t Rx_data_len=0;//Rx_sum=0,i,sum=0;

	//add ipchecksum	
	//if(icmp_header->type==ICMP_ECHO_REQUEST)//ICMP Echo
	//{
		if ((uip_len-(UIP_LLH_LEN+IP_HEADER_LENGTH)) >= sizeof (icmp_header)) 
		{
			//Rx_sum=icmp_header->icmpchksum;//checksum of receive packet
			//icmp_header->icmpchksum=0;
			//re calculate the checksum
			//sum=~(uip_chksum((u16_t *)&uip_buf[(UIP_LLH_LEN+IP_HEADER_LENGTH)], (uip_len-UIP_LLH_LEN-IP_HEADER_LENGTH))) ;
			//if ((sum-Rx_sum)== 0) 
			//{
				switch (icmp_header->type & 0xff) 
				{
				case ICMP_ECHO_REQUEST:
						Rx_data_len=iphdr->len-(IP_HEADER_LENGTH+ICMP_Header_Len);
						//Ethernet Header***************
						//Set Remote MAC address
					    memcpy(rx_eth->dest_mac, rx_eth->src_mac, 6);
						//Set My MAC address
						memcpy(rx_eth->src_mac, icp_netinfo.MY_MAC, 6);				
						//Type at the same with echo request packet
						//IP Header********************
						//
						//set remote ip address
						memcpy(iphdr->destipaddr, iphdr->srcipaddr, 4);
						//set my ip address
						iphdr->srcipaddr[0]=uip_hostaddr[0];
						iphdr->srcipaddr[1]=uip_hostaddr[1];
                        //set ipid
						ipid++;
						iphdr->ipid[0]=ipid>>8;
						iphdr->ipid[1]=ipid & 0xff;
                        //set ip header checksum
						iphdr->ipchksum=0;
						//iphdr->ipchksum=(~(uip_ipchksum()));
						//ICMP Header******************
						//Set ICMP TYPE
						icmp_header->type=ICMP_ECHO_REPLY;
						//icmp_header->icode=0; use the same with echo request
						//icmp_header->id=0;    use the same with echo request
						//icmp_header->seqno=0; use the same with echo request
						//Set ICMP Checksum
						icmp_header->icmpchksum=0;
						//icmp_header->icmpchksum=~(uip_chksum((u16_t *)&uip_buf[(UIP_LLH_LEN+IP_HEADER_LENGTH)], (uip_len-UIP_LLH_LEN-IP_HEADER_LENGTH))) ;
					    uip_len=UIP_LLH_LEN+IP_HEADER_LENGTH+ICMP_Header_Len+Rx_data_len;    		
					break;
	/*			case 0x03:
					printf ("ICMP error: destination unreachable\n");
					break;
				case 0x04:
					printf ("ICMP error: source quench\n");
					break;
				case 0x05:
					printf ("ICMP error: redirect\n");
					break;
				case 0x0b:
					printf ("ICMP error: time-to-live exceeded\n");
					break;
				case 0x0c:
					printf ("ICMP error: parameter problem\n");
					break;*/
				default:
				    uip_len = 0;
					break;
				}//switch end
			//}//checksum end
		}//uip_len end
		else
		{
			uip_len=0;
			return;
		}
	//}
}