[WinPcap-users] how to receive an ICMP echo reply

[Annie Deroo]

I'm trying to write something like a ping program. I send an ICMP echo request with the thread SendICMPPacket. Sending works fine, but I'm not capable of capturing the reply and recognize it as the reply. The program captures packets, but not all the packets, how can I change that? If somebody could check my code and give an answer why I don't capture everything and if IsICMPReply() should work. The code is written in Visual C++ and OnBICMP is the starting point.   Thank u.   void CPIGDlg::OnBICMP() {  if(initAdapter()){   //begin listening   AfxBeginThread(ListenThread,this);     Sleep(500);     //send the packet   AfxBeginThread(SendICMPPacket,this);   Sleep(6000); //wait for listenthread to finish  } }   UINT CPIGDlg::ListenThread(LPVOID pParam) {  CPIGDlg * dlg = (CPIGDlg *) pParam;  dlg->ListenThread();  return 0; }   void CPIGDlg::ListenThread() {  LPPACKET   lpPacket;  char buffer[256000];    if (!m_lpAdapter || (m_lpAdapter->hFile == INVALID_HANDLE_VALUE))  {   AfxMessageBox("Unable to open the adapter");  }     // set the network adapter in promiscuous mode   if(PacketSetHwFilter(m_lpAdapter,NDIS_PACKET_TYPE_PROMISCUOUS)==FALSE){    AfxMessageBox("Warning: unable to set promiscuous mode!");  }    // set a 512K buffer in the driver  if(PacketSetBuff(m_lpAdapter,512000)==FALSE){    AfxMessageBox("Unable to set the kernel buffer!");  }    // set a 1 second read timeout  if(PacketSetReadTimeout(m_lpAdapter,1000)==FALSE){    AfxMessageBox("Warning: unable to set the read timeout!");  }    //allocate and initialize a packet structure that will be used to  //receive the packets.  if((lpPacket = PacketAllocatePacket())==NULL){   AfxMessageBox("Error: failed to allocate the LPPACKET structure.");  }  PacketInitPacket(lpPacket,(char*)buffer,256000);    //main capture loop  while(true)  {      // capture the packets   if(PacketReceivePacket(m_lpAdapter,lpPacket,TRUE)==FALSE){    MessageBox("Error: PacketReceivePacket failed");   }   else{    if(lpPacket->ulBytesReceived!=0){     AfxMessageBox("packet captured");     (void)IsICMPReply(lpPacket);    }   }  }    PacketFreePacket(lpPacket);    // close the adapter and exit  PacketCloseAdapter(m_lpAdapter); }   BOOL CPIGDlg::IsICMPReply(LPPACKET lpPacket) {  BOOL bFlag = FALSE;  PIPHEADER pIPHeader;  PICMPPACKET pICMPPacket;   char *buf;  u_int off=0;  struct bpf_hdr *hdr;    buf = (char*)lpPacket->Buffer;  off=0;  hdr=(struct bpf_hdr *)(buf+off);  off+=hdr->bh_hdrlen;    pICMPPacket = (PICMPPACKET) (buf + off);  //cast the received lpPacket to a ICMPPacket    if (pICMPPacket->ehhdr.eh_type == htons(0x0800)){     //if the ethernet type = IP, can be icmp   if (strcmp((char*)(pICMPPacket->ehhdr.eh_dmac),m_myMAC) == 0    && pICMPPacket->icmphead.i_id == (USHORT)GetCurrentProcessId())    //if m_myMac = destination MAC and id = current process id   {    char szTemp[10];    pIPHeader = (PIPHEADER)(buf + off + sizeof(EHHDR));    memcpy(szTemp, &pIPHeader->sourceIP, sizeof(pIPHeader->sourceIP));    AfxMessageBox((char*)inet_ntoa(*((struct in_addr *)(szTemp))));    return TRUE;   }  }  return FALSE; }