Re: [WinPcap-users] problem receiving packets, packetReceivePacket problem

[Annie Deroo]

Thank you! Now it works. But I used ulBytesReceived, because Length was different from 0 even when it was a timeout, ulBytesReceived is only different when a real packet is captured. ----- Original Message ----- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, June 30, 2003 7:42 PM Subject: RE: [WinPcap-users] problem receiving packets, packetReceivePacket problem My guess from looking at the code is that what you are seeing is a return due to timeout.  You set the read timeout to 1 second, and this should cause PacketReceivePacket to return after 1 second, even if there is no data available.   My suggestion to you would be, 1 if you want the receive to block, don't seet the read timeout.  Or 2, use the lPacket->length to determine how to handle the packet.   SLH.   --- Steighton Haley                          [EMAIL PROTECTED] "There are 10 types of people in this world, those who understand binary, and those who don't." -----Original Message----- From: Annie Deroo [mailto:[EMAIL PROTECTED] Sent: Sunday, June 29, 2003 6:19 AM To: [EMAIL PROTECTED] Subject: [WinPcap-users] problem receiving packets, packetReceivePacket problem I have a problem receiving packets in my main capture loop. I call the ListenThread function from my program and start a new thread (it's not the thread that causes the problem, I still have the problem without it). The function packetReceivePacket(m_lpAdapter,lpPacket,TRUE) gives signals that I receive packets even when there aren't any packets send (I'm sure no packets are send, I watch the traffic with Ethereal), even when my computer is disconnected from any network, it still gives signals! The code is written under Visual C++ maybe that's a problem??? My adapter is good initialated, I can send packets (Ethereal shows them). So my question is: what's going wrong??? and of course, how do I solve this! Thank U.   AfxBeginThread(ListenThread,this);   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!\n");  }    // set a 512K buffer in the driver  if(PacketSetBuff(m_lpAdapter,512000)==FALSE){    AfxMessageBox("Unable to set the kernel buffer!\n");  }    // set a 1 second read timeout  if(PacketSetReadTimeout(m_lpAdapter,1000)==FALSE){    AfxMessageBox("Warning: unable to set the read tiemout!\n");  }    //allocate and initialize a packet structure that will be used to  //receive the packets.  if((lpPacket = PacketAllocatePacket())==NULL){   AfxMessageBox("\nError: 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{    AfxMessageBox("packet captured");   }  }    PacketFreePacket(lpPacket);  // close the adapter and exit  PacketCloseAdapter(m_lpAdapter); }