decoders/decode_ethernet.c

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#include "decode_ethernet.h"
#include "decode_interface.h"
#include "../packets/packet.h"
#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>

//#define DEBUG

extern GlobalVars       Globals;

/***************************************
* Apply the Ethernet decoding
****************************************/
void* DecodeEthernet(int PacketSlot){
        InterfaceRec*   r;
        EthernetData*   data;
        PacketRec*              p;
        
        DEBUGPATH;

        p=&Globals.Packets[PacketSlot];

        /*grab the interface to check the type*/
        /*The interface record is always the first on the stack*/
        r=((InterfaceData*)(p->DecoderInfo[0].Data))->r;
        
        if (r->Proto!=PACKET_PROTO_ETHERNET){
#ifdef DEBUG
                printf("This isn't an ethernet interface\n");
#endif                  
                return NULL;
        }

        data=malloc(sizeof(EthernetData));
        data->Header=(EtherHdr*)p->RawPacket;
        p->BeginData=sizeof(EtherHdr);
        
        return data;
}

/*************************************
* Set up the decoder
*************************************/
int InitDecoderEthernet(){
        int DecoderID;

        DEBUGPATH;
        
        if ((DecoderID=CreateDecoder("Ethernet"))==DECODER_NONE){
#ifdef DEBUG
                printf("Couldn't Allocate Ethernet Decoder\n");
#endif  
                return FALSE;
        }
        
        Globals.Decoders[DecoderID].DecodeFunc=DecodeEthernet;
        if (!DecoderAddDecoder(GetDecoderByName("Interface"), DecoderID)){
                printf("Failed to Bind Ethernet Decoder to Interface Decoder\n");
                return FALSE;
        }

        return TRUE;
}

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