libusb_filter.c

一个在Windows环境下允许用户程序访问USB设备的接口库的源代码.

/* LIBUSB-WIN32, Generic Windows USB Driver
 * Copyright (C) 2002-2003 Stephan Meyer, <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "libusb_filter.h"
#include <wchar.h>


static struct {
  KMUTEX mutex;
  int is_used[LIBUSB_MAX_NUMBER_OF_DEVICES];
} device_ids;

NTSTATUS __stdcall DriverEntry(DRIVER_OBJECT *driver_object,
			       UNICODE_STRING *registry_path)
{
  PDRIVER_DISPATCH *dispatch_function = driver_object->MajorFunction;
  int i;

  KeInitializeMutex(&device_ids.mutex, 0);

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_DEVICES; i++)
    {
      device_ids.is_used[i] = 0;
    }

  for(i = 0; i <= IRP_MJ_MAXIMUM_FUNCTION; i++, dispatch_function++) 
    {
      *dispatch_function = dispatch;
    }
  
  driver_object->DriverExtension->AddDevice = add_device;
  driver_object->DriverUnload = unload;

  debug_printf(DEBUG_MSG, "DriverEntry(): loading driver");

  return STATUS_SUCCESS;
}

NTSTATUS __stdcall add_device(DRIVER_OBJECT *driver_object, 
			      DEVICE_OBJECT *physical_device_object)
{
  NTSTATUS status;
  DEVICE_OBJECT *device_object;
  libusb_device_extension *device_extension;
  ULONG device_type = FILE_DEVICE_UNKNOWN;

  if(!IoIsWdmVersionAvailable(1, 0x20)) 
    {
      device_object = IoGetAttachedDeviceReference(physical_device_object);
      device_type = device_object->DeviceType;
      ObDereferenceObject(device_object);
    }
  
  status = IoCreateDevice(driver_object, sizeof(libusb_device_extension), 
			  NULL, device_type, 0, FALSE, &device_object);

  debug_printf(DEBUG_ERR, "add_device(): creating device");

  if(!NT_SUCCESS(status))
    {
      debug_printf(DEBUG_ERR, "add_device(): creating device failed");
      return status;
    }

  device_extension = (libusb_device_extension *)device_object->DeviceExtension;

  device_extension->self = device_object;
  device_extension->physical_device_object = physical_device_object;
  device_extension->next_stack_device = NULL;
  device_extension->control_device_object = NULL;
  device_extension->main_device_object = device_object;
  device_extension->driver_object = driver_object;
  device_extension->configuration_handle = NULL;
  device_extension->current_configuration = 0;
  device_extension->is_control_object = FALSE;
  device_extension->ref_count = 0;

  clear_pipe_info(device_extension);

  device_extension->next_stack_device = 
    IoAttachDeviceToDeviceStack(device_object, physical_device_object);
  
  device_object->DeviceType = device_extension->next_stack_device->DeviceType;
  device_object->Characteristics =
                          device_extension->next_stack_device->Characteristics;


  remove_lock_initialize(&device_extension->remove_lock);
  
  device_object->Flags |= device_extension->next_stack_device->Flags
    & (DO_BUFFERED_IO | DO_DIRECT_IO | DO_POWER_PAGABLE);

  device_object->Flags &= ~DO_DEVICE_INITIALIZING;
  
  return control_object_create(device_extension);
}


VOID __stdcall unload(DRIVER_OBJECT *driver_object)
{
  debug_printf(DEBUG_MSG, "unload(): unloading driver");
}


NTSTATUS complete_irp(IRP *irp, NTSTATUS status, ULONG info)
{
  irp->IoStatus.Status = status;
  irp->IoStatus.Information = info;
  IoCompleteRequest(irp, IO_NO_INCREMENT);
  
  return status;
}


NTSTATUS call_usbd(libusb_device_extension *device_extension, void *urb, 
		   ULONG control_code, int timeout)
{
  IO_STATUS_BLOCK io_status;
  KEVENT event;
  NTSTATUS status = STATUS_SUCCESS;
  IRP *irp;
  IO_STACK_LOCATION *next_irp_stack;
  
  KeInitializeEvent(&event, NotificationEvent, FALSE);

  irp = IoBuildDeviceIoControlRequest(control_code, 
				      device_extension->next_stack_device,
				      NULL, 0, NULL, 0, TRUE, 
				      &event, &io_status);

  if(!irp)
    {
      return STATUS_UNSUCCESSFUL;
    }

  next_irp_stack = IoGetNextIrpStackLocation(irp);
  next_irp_stack->Parameters.Others.Argument1 = urb;
  next_irp_stack->Parameters.Others.Argument2 = NULL;


  status = IoCallDriver(device_extension->next_stack_device, irp);
  

  if(status == STATUS_PENDING)
    {
      LARGE_INTEGER _timeout;
      _timeout.QuadPart = -(timeout * 10000);
      
      if(timeout)
	{
	  status = KeWaitForSingleObject(&event, Executive, KernelMode,
					 FALSE, &_timeout);
	}
      else
	{
	  status = KeWaitForSingleObject(&event, Executive, KernelMode,
					 FALSE, NULL);
	}

      if(status == STATUS_TIMEOUT)
	{
	  debug_printf(DEBUG_WARN, "call_usbd(): request timed out");
	  IoCancelIrp(irp);
	  KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
	}
      status = io_status.Status;
    }

  return status;
}


int get_pipe_handle(libusb_device_extension *device_extension, 
		    int endpoint_address, USBD_PIPE_HANDLE *pipe_handle)
{
  int i, j;

  *pipe_handle = NULL;

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_INTERFACES; i++)
    {
      for(j = 0; j < LIBUSB_MAX_NUMBER_OF_ENDPOINTS; j++)
	{
	  if(device_extension->pipe_info[i][j].endpoint_address 
	     == endpoint_address)
	    {
	      *pipe_handle = device_extension->pipe_info[i][j].pipe_handle;

	      if(!*pipe_handle)
		{
		  return FALSE;
		}
	      else
		{
		  return TRUE;
		}
	    }
	}
    }
  return FALSE;
}

void clear_pipe_info(libusb_device_extension *device_extension)
{
  int i, j;
  
  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_INTERFACES; i++)
    {
      for(j = 0; j < LIBUSB_MAX_NUMBER_OF_ENDPOINTS; j++)
	{
	  device_extension->pipe_info[i][j].endpoint_address = -1;	
	  device_extension->pipe_info[i][j].pipe_handle = NULL;
	} 
    }
}

int update_pipe_info(libusb_device_extension *device_extension, int interface,
		     USBD_INTERFACE_INFORMATION *interface_info)
{
  int i;

  if(interface > LIBUSB_MAX_NUMBER_OF_INTERFACES)
    {
      return FALSE;
    }

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_ENDPOINTS ; i++)
    {
      device_extension->pipe_info[interface][i].endpoint_address = -1;	
      device_extension->pipe_info[interface][i].pipe_handle = NULL;	
    } 

  if(interface_info)
    {
      debug_printf(DEBUG_MSG, "update_pipe_info(): interface %d",
	       interface);
      for(i = 0; i < (int)interface_info->NumberOfPipes
	    && i < LIBUSB_MAX_NUMBER_OF_ENDPOINTS; i++) 
	{
	  debug_printf(DEBUG_MSG, "update_pipe_info(): endpoint "
		       "address %02xh",
		       interface_info->Pipes[i].EndpointAddress);	  

	  device_extension->pipe_info[interface][i].pipe_handle = 
	    interface_info->Pipes[i].PipeHandle;	
	  device_extension->pipe_info[interface][i].endpoint_address = 
	    interface_info->Pipes[i].EndpointAddress;	
	}
    }

  return TRUE;
}


NTSTATUS control_object_create(libusb_device_extension *device_extension)
{
  NTSTATUS status = STATUS_SUCCESS;
  UNICODE_STRING nt_device_name;
  UNICODE_STRING symbolic_link_name;
  WCHAR tmp_name_0[64];
  WCHAR tmp_name_1[64];
  libusb_device_extension *control_extension;


  if(!get_device_id(device_extension))
    {
      debug_printf(DEBUG_ERR, "create_control_object(): getting device id"
	       " failed");
      return STATUS_UNSUCCESSFUL;
    }

  debug_printf(DEBUG_MSG, "create_control_object(): creating device %d",
	       device_extension->device_id);

  _snwprintf(tmp_name_0, sizeof(tmp_name_0)/sizeof(WCHAR), L"%s%04d", 
	     LIBUSB_NT_DEVICE_NAME,
	     device_extension->device_id);
  
  RtlInitUnicodeString(&nt_device_name, tmp_name_0);

  _snwprintf(tmp_name_1, sizeof(tmp_name_1)/sizeof(WCHAR), L"%s%04d", 
	     LIBUSB_SYMBOLIC_LINK_NAME,
	     device_extension->device_id);
  
  RtlInitUnicodeString(&symbolic_link_name, tmp_name_1);

  status = IoCreateDevice(device_extension->driver_object,
			  sizeof(libusb_device_extension), 
			  &nt_device_name,
			  FILE_DEVICE_UNKNOWN, 0, FALSE, 
			  &device_extension->control_device_object);
  if(!NT_SUCCESS(status))
    {
      debug_printf(DEBUG_ERR, "create_control_object(): creating device"
		   " %d failed", device_extension->device_id);
      device_extension->control_device_object = NULL;
      return status;
    }

  control_extension = (libusb_device_extension *)device_extension
    ->control_device_object->DeviceExtension;


  status = IoCreateSymbolicLink(&symbolic_link_name, &nt_device_name );

  if(!NT_SUCCESS(status))
    {
      debug_printf(DEBUG_ERR, "control_object_create(): creating symbolic "
		   "link failed");
      IoDeleteDevice(device_extension->control_device_object);
      device_extension->control_device_object = NULL;
      return status;
    }
  
  control_extension->self = device_extension->control_device_object;
  control_extension->main_device_object = device_extension->self;
  control_extension->control_device_object = NULL;
  control_extension->physical_device_object 
    = device_extension->physical_device_object;
  control_extension->is_control_object = TRUE;
  control_extension->ref_count = 0;
  control_extension->device_id = device_extension->device_id;

  device_extension->control_device_object->Flags 
    |= DO_BUFFERED_IO | DO_DIRECT_IO;
  device_extension->control_device_object->Flags &= ~DO_DEVICE_INITIALIZING;

  return status;
}

void control_object_delete(libusb_device_extension *device_extension)
{
  UNICODE_STRING symbolic_link_name;
  WCHAR tmp_name[64];
 
  libusb_device_extension *control_extension;

  if(device_extension->control_device_object
     && device_extension->device_id >= 0)
    {
      control_extension = (libusb_device_extension *)
	device_extension->control_device_object->DeviceExtension;

      debug_printf(DEBUG_ERR, "control_object_delete(): deleting device %d",
		   device_extension->device_id);
      
      _snwprintf(tmp_name, sizeof(tmp_name)/sizeof(WCHAR), L"%s%04d", 
		 LIBUSB_SYMBOLIC_LINK_NAME,
		 device_extension->device_id);
      
      RtlInitUnicodeString(&symbolic_link_name, tmp_name);
      
      control_extension->main_device_object = NULL;

      if(!NT_SUCCESS(IoDeleteSymbolicLink(&symbolic_link_name)))
	{
	  debug_printf(DEBUG_ERR, "control_object_delete(): "
		       "IoDeleteSymbolicLink() failed\n");
	}
      
      if(!control_extension->ref_count)
	{
	  debug_printf(DEBUG_MSG, "control_object_delete(): releasing device "
		       "id %d", device_extension->device_id);
	  release_device_id(device_extension);
	}

      IoDeleteDevice(device_extension->control_device_object);
      device_extension->control_device_object = NULL;
    }
}

void remove_lock_initialize(libusb_remove_lock *remove_lock)
{
  KeInitializeEvent(&remove_lock->event, NotificationEvent, FALSE);
  remove_lock->usage_count = 1;
  remove_lock->remove_pending = FALSE;
}


NTSTATUS remove_lock_acquire(libusb_remove_lock *remove_lock)
{
  InterlockedIncrement(&remove_lock->usage_count);

  if(remove_lock->remove_pending)
    {
      if(InterlockedDecrement(&remove_lock->usage_count) == 0)
	{
	  KeSetEvent(&remove_lock->event, 0, FALSE);
	}      
      return STATUS_DELETE_PENDING;
    }
  return STATUS_SUCCESS;
}


void remove_lock_release(libusb_remove_lock *remove_lock)
{
  if(InterlockedDecrement(&remove_lock->usage_count) == 0)
    {
      KeSetEvent(&remove_lock->event, 0, FALSE);
    }
}


void remove_lock_release_and_wait(libusb_remove_lock *remove_lock)
{
  remove_lock->remove_pending = TRUE;
  remove_lock_release(remove_lock);
  remove_lock_release(remove_lock);
  KeWaitForSingleObject(&remove_lock->event, Executive, KernelMode,
			FALSE, NULL);
}


int get_device_id(libusb_device_extension *device_extension)
{
  int ret = FALSE;
  int i;
  
  device_extension->device_id = -1;

  KeWaitForSingleObject(&device_ids.mutex, Executive, KernelMode,
			FALSE, NULL);

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_DEVICES; i++)
    {
      if(!device_ids.is_used[i])
	{
	  device_ids.is_used[i] = TRUE;
	  device_extension->device_id = i;
	  ret = TRUE;
	  break;
	}
    }

  KeReleaseMutex(&device_ids.mutex, FALSE);
  return ret;
}

void release_device_id(libusb_device_extension *device_extension)
{
  if(device_extension->device_id >= 0)
    {
      KeWaitForSingleObject(&device_ids.mutex, Executive, KernelMode,
			    FALSE, NULL);
      
      if(device_extension->device_id < LIBUSB_MAX_NUMBER_OF_DEVICES)
	{
	  device_ids.is_used[device_extension->device_id] = FALSE;
	}

      KeReleaseMutex(&device_ids.mutex, FALSE);
    }
}

NTSTATUS on_device_usage_notification_complete(DEVICE_OBJECT *device_object,
					       IRP *irp,
					       void *context)
{
  libusb_device_extension *device_extension
    = (libusb_device_extension *)device_object->DeviceExtension;

  if(irp->PendingReturned)
    {
      IoMarkIrpPending(irp);
    }

  if(!(device_extension->next_stack_device->Flags & DO_POWER_PAGABLE))
    {
        device_object->Flags &= ~DO_POWER_PAGABLE;
    }

  return STATUS_SUCCESS;
}

NTSTATUS on_start_complete(DEVICE_OBJECT *device_object, IRP *irp, 
			   void *context)
{
  libusb_device_extension *device_extension
    = (libusb_device_extension *)device_object->DeviceExtension;

  if(irp->PendingReturned)
    {
      IoMarkIrpPending(irp);
    }

  if(NT_SUCCESS(irp->IoStatus.Status)) 
    {
      if(device_extension->next_stack_device->Characteristics 
	 & FILE_REMOVABLE_MEDIA) 
	{
	  device_object->Characteristics |= FILE_REMOVABLE_MEDIA;
        }
    }
  
  return STATUS_SUCCESS;
}