etherneticmp.c

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/******************************************************
* Function: etherent icmp protocol handler
*
* File:   etherenticmp.c
* Author: Book Chen
* Date:   2008.07.18
*******************************************************
*/
#include "includes.h"

#define EthernetIcmpIdleState 0

ICMP_CONTROL IcmpCtrl;
void F_EthernetIcmpInit(void);
INT8U F_EthernetIcmpEchoSend(ETHBUFFER *pBuffer);
INT8U F_EthernetIcmpEchoReceive(ETHBUFFER *pBuffer);
INT8U F_EthernetIcmpPacketReceive(ETHBUFFER *pBuffer);

void F_EthernetIcmpInit(void){
    IcmpCtrl.ClientIp[0]=0;    
    IcmpCtrl.ClientIp[1]=0;    
    IcmpCtrl.ClientIp[2]=0;    
    IcmpCtrl.ClientIp[3]=0;   
    IcmpCtrl.Status=0;
    IcmpCtrl.State=EthernetIcmpIdleState; 
}
INT8U F_EthernetIcmpEchoSend(ETHBUFFER *pBuffer){
    ICMP_HEAD *pIcmpHead,*pIcmpEcho;
    INT32U Temp,Sum,Counter,i;
        
    Counter=pBuffer->Length; // keep icmp packet data length in Counter
    if(Counter%2) Counter++; // ?? Counter must be a even number
    #if(DEBUG_ETHERNET_ICMP==1)
        printf(" echo length %4x",Counter);
    #endif
    pIcmpHead=(ICMP_HEAD *)pBuffer->pData;
    pBuffer=F_EthernetBufferAllocate();
    F_EthernetIpBufferReserve(pBuffer); // reserve IP_HEAD space 
    pIcmpEcho=(ICMP_HEAD *)F_EthernetBufferPut(pBuffer,Counter);    
    pIcmpEcho->Type=0;
    pIcmpEcho->Code=0;
    Sum=0;
    for(i=2;i<(Counter/2);i++){
        Temp=*((INT16U *)(&pIcmpHead->Type)+i);
        *((INT16U *)(&pIcmpEcho->Type)+i)=Temp;
        Sum+=Temp;
    }
    i=Sum>>16;
    pIcmpEcho->Check=0x0000ffff-(Sum&0x0000ffff)-i;
    #if(DEBUG_ETHERNET_ICMP==1)
        printf(" length2 %4x",pBuffer->Length);
    #endif
    F_EthernetIpSend(pBuffer,IcmpCtrl.ClientIp,ICMP);
    return TRUE;
}
INT8U F_EthernetIcmpEchoReceive(ETHBUFFER *pBuffer){
    memcpy(IcmpCtrl.ClientIp,IpCtrl.SourceIp,ETHERNET_IP_LENGTH);
    F_EthernetIcmpEchoSend(pBuffer);
    return TRUE;
}
INT8U F_EthernetIcmpPacketReceive(ETHBUFFER *pBuffer){
    ICMP_HEAD *pIcmpHead=(ICMP_HEAD *)pBuffer->pData;
    
    #if(DEBUG_ETHERNET_ICMP==1)
        printf("\n ICMP rx");
    #endif
    switch(pIcmpHead->Type){
        case 8:
            F_EthernetIcmpEchoReceive(pBuffer);    
    }
    return TRUE;
}