tapdrvr.c

一个Windows下的Linux专用虚拟机

	  if (NewDeviceState > NdisDeviceStateD0)
	    {
	      l_Adapter->m_InterfaceIsRunning = FALSE;
	      DEBUGP (("[%s] Power management device state OFF\n",
		       NAME (l_Adapter)));
	    }
	  else
	    {
	      l_Adapter->m_InterfaceIsRunning = TRUE;
	      DEBUGP (("[%s] Power management device state ON\n",
		       NAME (l_Adapter)));
	    }

	  l_Status = NDIS_STATUS_SUCCESS;
	}
      while (FALSE);

      if (l_Status == NDIS_STATUS_SUCCESS)
	{
	  *p_BytesRead = sizeof (NDIS_DEVICE_POWER_STATE);
	  *p_BytesNeeded = 0;
	}
      else
	{
	  *p_BytesRead = 0;
	  *p_BytesNeeded = sizeof (NDIS_DEVICE_POWER_STATE);
	}
      break;

    case OID_PNP_REMOVE_WAKE_UP_PATTERN:
    case OID_PNP_ADD_WAKE_UP_PATTERN:
      l_Status = NDIS_STATUS_SUCCESS;
      *p_BytesRead = *p_BytesNeeded = 0;
      break;

    default:
      DEBUGP (("[%s] Can't set value for OID %lx\n", NAME (l_Adapter),
	       p_OID));
      l_Status = NDIS_STATUS_INVALID_OID;
      *p_BytesRead = *p_BytesNeeded = 0;
      break;
    }

  return l_Status;
}

//====================================================================
//                               Adapter Transmission
//====================================================================
NDIS_STATUS
AdapterTransmit (IN NDIS_HANDLE p_AdapterContext,
		 IN PNDIS_PACKET p_Packet,
		 IN UINT p_Flags)
{
  TapAdapterPointer l_Adapter = (TapAdapterPointer) p_AdapterContext;
  ULONG l_Index = 0, l_BufferLength = 0, l_PacketLength = 0;
  PIRP l_IRP;
  TapPacketPointer l_PacketBuffer;
  PNDIS_BUFFER l_NDIS_Buffer;
  PUCHAR l_Buffer;
  PVOID result;

  NdisQueryPacket (p_Packet, NULL, NULL, &l_NDIS_Buffer, &l_PacketLength);

  //====================================================
  // Here we abandon the transmission attempt if any of
  // the parameters is wrong or memory allocation fails
  // but we do not indicate failure. The packet is
  // silently dropped.
  //====================================================

  if (l_PacketLength < ETHERNET_HEADER_SIZE || l_PacketLength > 65535)
    goto exit_fail;
  else if (!l_Adapter->m_Extension.m_TapOpens || !l_Adapter->m_MediaState)
    goto exit_success;              // Nothing is bound to the TAP device

  if (NdisAllocateMemoryWithTag (&l_PacketBuffer,
				 TAP_PACKET_SIZE (l_PacketLength),
				 '5PAT') != NDIS_STATUS_SUCCESS)
    goto exit_no_resources;

  if (l_PacketBuffer == NULL)
    goto exit_no_resources;

  l_PacketBuffer->m_SizeFlags = (l_PacketLength & TP_SIZE_MASK);

  //===========================
  // Reassemble packet contents
  //===========================

  __try
  {
    l_Index = 0;
    while (l_NDIS_Buffer && l_Index < l_PacketLength)
      {
	ULONG newlen;
	NdisQueryBuffer (l_NDIS_Buffer, (PVOID *) & l_Buffer,
			 &l_BufferLength);
	newlen = l_Index + l_BufferLength;
	if (newlen > l_PacketLength)
	  {
	    NOTE_ERROR ();
	    goto no_queue; /* overflow */
	  }
	NdisMoveMemory (l_PacketBuffer->m_Data + l_Index, l_Buffer,
			l_BufferLength);
	l_Index = newlen;
	NdisGetNextBuffer (l_NDIS_Buffer, &l_NDIS_Buffer);
      }
    if (l_Index != l_PacketLength)
      {
	NOTE_ERROR ();
	goto no_queue; /* underflow */
      }

    DUMP_PACKET ("AdapterTransmit", l_PacketBuffer->m_Data, l_PacketLength);

    //=====================================================
    // If IPv4 packet, check whether or not packet
    // was truncated.
    //=====================================================
#if PACKET_TRUNCATION_CHECK
    IPv4PacketSizeVerify (l_PacketBuffer->m_Data, l_PacketLength, FALSE, "TX", &l_Adapter->m_TxTrunc);
#endif

    //=====================================================
    // Are we running in DHCP server masquerade mode?
    //
    // If so, catch both DHCP requests and ARP queries
    // to resolve the address of our virtual DHCP server.
    //=====================================================
    if (l_Adapter->m_dhcp_enabled)
      {
	const ETH_HEADER *eth = (ETH_HEADER *) l_PacketBuffer->m_Data;
	const IPHDR *ip = (IPHDR *) (l_PacketBuffer->m_Data + sizeof (ETH_HEADER));
	const UDPHDR *udp = (UDPHDR *) (l_PacketBuffer->m_Data + sizeof (ETH_HEADER) + sizeof (IPHDR));

	// ARP packet?
	if (l_PacketLength == sizeof (ARP_PACKET)
	    && eth->proto == htons (ETH_P_ARP)
	    && l_Adapter->m_dhcp_server_arp)
	  {
	    if (ProcessARP (l_Adapter,
			    (PARP_PACKET) l_PacketBuffer->m_Data,
			    l_Adapter->m_dhcp_addr,
			    l_Adapter->m_dhcp_server_ip,
			    ~0,
			    l_Adapter->m_dhcp_server_mac))
	      goto no_queue;
	  }

	// DHCP packet?
	else if (l_PacketLength >= sizeof (ETH_HEADER) + sizeof (IPHDR) + sizeof (UDPHDR) + sizeof (DHCP)
		 && eth->proto == htons (ETH_P_IP)
		 && ip->version_len == 0x45 // IPv4, 20 byte header
		 && ip->protocol == IPPROTO_UDP
		 && udp->dest == htons (BOOTPS_PORT))
	  {
	    const DHCP *dhcp = (DHCP *) (l_PacketBuffer->m_Data
					 + sizeof (ETH_HEADER)
					 + sizeof (IPHDR)
					 + sizeof (UDPHDR));

	    const int optlen = l_PacketLength
	      - sizeof (ETH_HEADER)
	      - sizeof (IPHDR)
	      - sizeof (UDPHDR)
	      - sizeof (DHCP);

	    if (optlen > 0) // we must have at least one DHCP option
	      {
		if (ProcessDHCP (l_Adapter, eth, ip, udp, dhcp, optlen))
		  goto no_queue;
	      }
	    else
	      goto no_queue;
	  }
      }

    //===============================================
    // In Point-To-Point mode, check to see whether
    // packet is ARP or IPv4 (if neither, then drop).
    //===============================================
    if (l_Adapter->m_tun)
      {
	ETH_HEADER *e;

	if (l_PacketLength < ETHERNET_HEADER_SIZE)
	  goto no_queue;

	e = (ETH_HEADER *) l_PacketBuffer->m_Data;

	switch (ntohs (e->proto))
	  {
	  case ETH_P_ARP:

	    // Make sure that packet is the
	    // right size for ARP.
	    if (l_PacketLength != sizeof (ARP_PACKET))
	      goto no_queue;

	    ProcessARP (l_Adapter,
			(PARP_PACKET) l_PacketBuffer->m_Data,
			l_Adapter->m_localIP,
			l_Adapter->m_remoteNetwork,
			l_Adapter->m_remoteNetmask,
			l_Adapter->m_TapToUser.dest);

	  default:
	    goto no_queue;

	  case ETH_P_IP:

	    // Make sure that packet is large
	    // enough to be IPv4.
	    if (l_PacketLength
		< ETHERNET_HEADER_SIZE + IP_HEADER_SIZE)
	      goto no_queue;

	    // Only accept directed packets,
	    // not broadcasts.
	    if (memcmp (e, &l_Adapter->m_TapToUser, ETHERNET_HEADER_SIZE))
	      goto no_queue;

	    // Packet looks like IPv4, queue it.
	    l_PacketBuffer->m_SizeFlags |= TP_TUN;
	  }
      }

    //===============================================
    // Push packet onto queue to wait for read from
    // userspace.
    //===============================================

    NdisAcquireSpinLock (&l_Adapter->m_Extension.m_QueueLock);

    result = NULL;
    if (IS_UP (l_Adapter))
      result = QueuePush (l_Adapter->m_Extension.m_PacketQueue, l_PacketBuffer);

    NdisReleaseSpinLock (&l_Adapter->m_Extension.m_QueueLock);

    if ((TapPacketPointer) result != l_PacketBuffer)
      {
	// adapter receive overrun
	INCREMENT_STAT (l_Adapter->m_TxErr);
	goto no_queue;
      }
    else
      {
	INCREMENT_STAT (l_Adapter->m_Tx);
      }

    //============================================================
    // Cycle through IRPs and packets, try to satisfy each pending
    // IRP with a queued packet.
    //============================================================
    while (TRUE)
      {
	l_IRP = NULL;
	l_PacketBuffer = NULL;

	NdisAcquireSpinLock (&l_Adapter->m_Extension.m_QueueLock);

	if (IS_UP (l_Adapter)
	    && QueueCount (l_Adapter->m_Extension.m_PacketQueue)
	    && QueueCount (l_Adapter->m_Extension.m_IrpQueue))
	  {
	    l_IRP = (PIRP) QueuePop (l_Adapter->m_Extension.m_IrpQueue);
	    l_PacketBuffer = (TapPacketPointer)
	      QueuePop (l_Adapter->m_Extension.m_PacketQueue);
	  }

	NdisReleaseSpinLock (&l_Adapter->m_Extension.m_QueueLock);

	MYASSERT ((l_IRP != NULL) + (l_PacketBuffer != NULL) != 1);

	if (l_IRP && l_PacketBuffer)
	  {
	    CompleteIRP (l_IRP,
			 l_PacketBuffer, 
			 IO_NETWORK_INCREMENT);
	  }
	else
	  break;
      }
  }
  __except (EXCEPTION_EXECUTE_HANDLER)
    {
    }

  return NDIS_STATUS_SUCCESS;

 no_queue:
  NdisFreeMemory (l_PacketBuffer,
		  TAP_PACKET_SIZE (l_PacketLength),
		  0);
  
 exit_success:
  return NDIS_STATUS_SUCCESS;
    
 exit_fail:
  return NDIS_STATUS_FAILURE;

 exit_no_resources:
  return NDIS_STATUS_RESOURCES;
}

//======================================================================
// Hooks for catching TAP device IRP's.
//======================================================================

NTSTATUS
TapDeviceHook (IN PDEVICE_OBJECT p_DeviceObject, IN PIRP p_IRP)
{
  TapAdapterPointer l_Adapter = LookupAdapterInInstanceList (p_DeviceObject);
  PIO_STACK_LOCATION l_IrpSp;
  NTSTATUS l_Status = STATUS_SUCCESS;
  BOOLEAN accessible;

  l_IrpSp = IoGetCurrentIrpStackLocation (p_IRP);

  p_IRP->IoStatus.Status = STATUS_SUCCESS;
  p_IRP->IoStatus.Information = 0;

  if (!l_Adapter || l_Adapter->m_Extension.m_Halt)
    {
      DEBUGP (("TapDeviceHook called when TAP device is halted, MajorFunction=%d\n",
	       (int)l_IrpSp->MajorFunction));

      if (l_IrpSp->MajorFunction == IRP_MJ_CLOSE)
	{
	  IoCompleteRequest (p_IRP, IO_NO_INCREMENT);
	  return STATUS_SUCCESS;
	}
      else
	{
	  p_IRP->IoStatus.Status = STATUS_NO_SUCH_DEVICE;
	  IoCompleteRequest (p_IRP, IO_NO_INCREMENT);
	  return STATUS_NO_SUCH_DEVICE;
	}
    }

  switch (l_IrpSp->MajorFunction)
    {
      //===========================================================
      //                 Ioctl call handlers
      //===========================================================
    case IRP_MJ_DEVICE_CONTROL:
      {
	switch (l_IrpSp->Parameters.DeviceIoControl.IoControlCode)
	  {
	  case TAP_IOCTL_GET_MAC:
	    {
	      if (l_IrpSp->Parameters.DeviceIoControl.OutputBufferLength
		  >= sizeof (MACADDR))
		{
		  COPY_MAC (p_IRP->AssociatedIrp.SystemBuffer,
			    l_Adapter->m_MAC);
		  p_IRP->IoStatus.Information = sizeof (MACADDR);
		}
	      else
		{
		  NOTE_ERROR ();
		  p_IRP->IoStatus.Status = l_Status = STATUS_BUFFER_TOO_SMALL;
		}
	      break;
	    }
	  case TAP_IOCTL_GET_VERSION:
	    {
	      const ULONG size = sizeof (ULONG) * 3;
	      if (l_IrpSp->Parameters.DeviceIoControl.OutputBufferLength
		  >= size)
		{
		  ((PULONG) (p_IRP->AssociatedIrp.SystemBuffer))[0]
		    = TAP_DRIVER_MAJOR_VERSION;
		  ((PULONG) (p_IRP->AssociatedIrp.SystemBuffer))[1]
		    = TAP_DRIVER_MINOR_VERSION;
		  ((PULONG) (p_IRP->AssociatedIrp.SystemBuffer))[2]
#if DBG
		    = 1;
#else
		  = 0;
#endif
		  p_IRP->IoStatus.Information = size;
		}
	      else
		{
		  NOTE_ERROR ();
		  p_IRP->IoStatus.Status = l_Status = STATUS_BUFFER_TOO_SMALL;
		}

	      break;
	    }
	  case TAP_IOCTL_GET_MTU:
	    {
	      const ULONG size = sizeof (ULONG) * 1;
	      if (l_IrpSp->Parameters.DeviceIoControl.OutputBufferLength
		  >= size)
		{
		  ((PULONG) (p_IRP->AssociatedIrp.SystemBuffer))[0]
		    = l_Adapter->m_MTU;
		  p_IRP->IoStatus.Information = size;
		}
	      else
		{
		  NOTE_ERROR ();
		  p_IRP->IoStatus.Status = l_Status = STATUS_BUFFER_TOO_SMALL;
		}

	      break;
	    }
	  case TAP_IOCTL_GET_INFO:
	    {
	      char state[16];
	      if (l_Adapter->m_InterfaceIsRunning)
		state[0] = 'A';
	      else
		state[0] = 'a';
	      if (l_Adapter->m_Extension.m_TapIsRunning)
		state[1] = 'T';
	      else
		state[1] = 't';
	      state[2] = l_Adapter->m_DeviceState;
	      if (l_Adapter->m_MediaStateAlwaysConnected)
		state[3] = 'C';
	      else
		state[3] = 'c';
	      state[4] = '\0';

	      p_IRP->IoStatus.Status = l_Status = RtlStringCchPrintfExA (
	        ((LPTSTR) (p_IRP->AssociatedIrp.SystemBuffer)),
		l_IrpSp->Parameters.DeviceIoControl.OutputBufferLength,
		NULL,
		NULL,
		STRSAFE_FILL_BEHIND_NULL | STRSAFE_IGNORE_NULLS,
#if PACKET_TRUNCATION_CHECK
		"State=%s Err=[%s/%d] #O=%d Tx=[%d,%d,%d] Rx=[%d,%d,%d] IrpQ=[%d,%d,%d] PktQ=[%d,%d,%d]",
#else
		"State=%s Err=[%s/%d] #O=%d Tx=[%d,%d] Rx=[%d,%d] IrpQ=[%d,%d,%d] PktQ=[%d,%d,%d]",
#endif
		state,
		g_LastErrorFilename,
		g_LastErrorLineNumber,
		(int)l_Adapter->m_Extension.m_NumTapOpens,
		(int)l_Adapter->m_Tx,
		(int)l_Adapter->m_TxErr,
#if PACKET_TRUNCATION_CHECK
		(int)l_Adapter->m_TxTrunc,