libusb_driver.c

Libusb-win32 is a library that allows userspace application to access USB devices on Windows opera

/* LIBUSB-WIN32, Generic Windows USB Library
 * Copyright (c) 2002-2005 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
 */


#define __LIBUSB_DRIVER_C__

#include "libusb_driver.h"

extern int debug_level;

static void DDKAPI unload(DRIVER_OBJECT *driver_object);

static NTSTATUS DDKAPI on_usbd_complete(DEVICE_OBJECT *device_object, 
                                        IRP *irp, 
                                        void *context);

NTSTATUS DDKAPI DriverEntry(DRIVER_OBJECT *driver_object,
                            UNICODE_STRING *registry_path)
{
  int i;

  DEBUG_MESSAGE("DriverEntry(): loading driver");

  /* initialize global variables */
  debug_level = LIBUSB_DEBUG_MSG;

  /* initialize the driver object's dispatch table */
  for(i = 0; i <= IRP_MJ_MAXIMUM_FUNCTION; i++) 
    {
      driver_object->MajorFunction[i] = dispatch;
    }
  
  driver_object->DriverExtension->AddDevice = add_device;
  driver_object->DriverUnload = unload;

  return STATUS_SUCCESS;
}

NTSTATUS DDKAPI add_device(DRIVER_OBJECT *driver_object, 
                           DEVICE_OBJECT *physical_device_object)
{
  NTSTATUS status;
  DEVICE_OBJECT *device_object = NULL;
  libusb_device_t *dev;
  ULONG device_type;

  UNICODE_STRING nt_device_name;
  UNICODE_STRING symbolic_link_name;
  WCHAR tmp_name_0[128];
  WCHAR tmp_name_1[128];
  char id[256];
  int i;

  /* get the hardware ID from the registry */
  if(!reg_get_hardware_id(physical_device_object, id, sizeof(id)))
    {
      DEBUG_ERROR("add_device(): unable to read registry");
      return STATUS_SUCCESS;
    }

  /* only attach the (filter) driver to USB devices, skip hubs */
  /* and interfaces of composite devices */
  if(!strstr(id, "usb\\") || strstr(id, "hub") || strstr(id, "&mi_"))
    {
      return STATUS_SUCCESS;
    }

  /* retrieve the type of the lower device object */
  device_object = IoGetAttachedDeviceReference(physical_device_object);

  if(device_object)
    {
      device_type = device_object->DeviceType;
      ObDereferenceObject(device_object);
    }
  else
    {
      device_type = FILE_DEVICE_UNKNOWN;
    }

  /* try to create a new device object */
  for(i = 1; i < LIBUSB_MAX_NUMBER_OF_DEVICES; i++)
    {
      /* initialize some unicode strings */
      _snwprintf(tmp_name_0, sizeof(tmp_name_0)/sizeof(WCHAR), L"%s%04d", 
                 LIBUSB_NT_DEVICE_NAME, i);
      _snwprintf(tmp_name_1, sizeof(tmp_name_1)/sizeof(WCHAR), L"%s%04d", 
                 LIBUSB_SYMBOLIC_LINK_NAME, i);

      RtlInitUnicodeString(&nt_device_name, tmp_name_0);  
      RtlInitUnicodeString(&symbolic_link_name, tmp_name_1);

      /* create the object */
      status = IoCreateDevice(driver_object, 
                              sizeof(libusb_device_t), 
                              &nt_device_name, device_type, 0, FALSE, 
                              &device_object);

      if(NT_SUCCESS(status))
        {
          DEBUG_MESSAGE("add_device(): device #%d created", i);
          break;
        }

      device_object = NULL;

      /* continue until an unused device name is found */
    }

  if(!device_object)
    {
      DEBUG_ERROR("add_device(): creating device failed");
      return status;
    }
      
  status = IoCreateSymbolicLink(&symbolic_link_name, &nt_device_name);
  
  if(!NT_SUCCESS(status))
    {
      DEBUG_ERROR("add_device(): creating symbolic link failed");
      IoDeleteDevice(device_object);
      return status;
    }

  /* setup the "device object" */
  dev = device_object->DeviceExtension;

  memset(dev, 0, sizeof(libusb_device_t));


  /* attach the newly created device object to the stack */
  dev->next_stack_device = 
    IoAttachDeviceToDeviceStack(device_object, physical_device_object);

  if(!dev->next_stack_device)
    {
      DEBUG_ERROR("add_device(): attaching to device stack failed");
      IoDeleteSymbolicLink(&symbolic_link_name);
      IoDeleteDevice(device_object);
      return STATUS_NO_SUCH_DEVICE;
    }

  dev->self = device_object;
  dev->physical_device_object = physical_device_object;
  dev->id = i;

  /* set initial power states */
  dev->power_state.DeviceState = PowerDeviceD0;
  dev->power_state.SystemState = PowerSystemWorking;

  /* get device properties from the registry */
  reg_get_properties(dev);

  if(dev->is_filter)
    {
      /* send all USB requests to the PDO in filter driver mode */
      dev->target_device = dev->physical_device_object;

      /* use the same flags as the underlying object */
      device_object->Flags |= dev->next_stack_device->Flags 
        & (DO_BUFFERED_IO | DO_DIRECT_IO | DO_POWER_PAGABLE);
    }
  else
    {
      /* send all USB requests to the lower object in device driver mode */
      dev->target_device = dev->next_stack_device;

      device_object->Flags |= DO_DIRECT_IO | DO_POWER_PAGABLE;
    }

  clear_pipe_info(dev);

  remove_lock_initialize(dev);

  device_object->Flags &= ~DO_DEVICE_INITIALIZING;

  return status;
}


VOID DDKAPI unload(DRIVER_OBJECT *driver_object)
{
  DEBUG_MESSAGE("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_t *dev, void *urb, ULONG control_code,  
                   int timeout)
{
  KEVENT event;
  NTSTATUS status;
  IRP *irp;
  IO_STACK_LOCATION *next_irp_stack;
  LARGE_INTEGER _timeout;
  IO_STATUS_BLOCK io_status;

  if(timeout > LIBUSB_MAX_CONTROL_TRANSFER_TIMEOUT)
    {
      timeout = LIBUSB_MAX_CONTROL_TRANSFER_TIMEOUT;
    }

  KeInitializeEvent(&event, NotificationEvent, FALSE);

  irp = IoBuildDeviceIoControlRequest(control_code, dev->target_device,
                                      NULL, 0, NULL, 0, TRUE,
                                      NULL, &io_status);

  if(!irp)
    {
      return STATUS_NO_MEMORY;
    }

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

  IoSetCompletionRoutine(irp, on_usbd_complete, &event, TRUE, TRUE, TRUE); 

  status = IoCallDriver(dev->target_device, irp);
    
  if(status == STATUS_PENDING)
    {
      _timeout.QuadPart = -(timeout * 10000);
      
      if(KeWaitForSingleObject(&event, Executive, KernelMode,
                               FALSE, &_timeout) == STATUS_TIMEOUT)
        {
          DEBUG_ERROR("call_usbd(): request timed out");
          IoCancelIrp(irp);
        }
    }

  /* wait until completion routine is called */
  KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);

  status = irp->IoStatus.Status;
  
  /* complete the request */
  IoCompleteRequest(irp, IO_NO_INCREMENT);

  return status;
}


static NTSTATUS DDKAPI on_usbd_complete(DEVICE_OBJECT *device_object, 
                                        IRP *irp, void *context)
{
  KeSetEvent((KEVENT *) context, IO_NO_INCREMENT, FALSE);

  return STATUS_MORE_PROCESSING_REQUIRED;
}


NTSTATUS pass_irp_down(libusb_device_t *dev, IRP *irp, 
                       PIO_COMPLETION_ROUTINE completion_routine, 
                       void *context)
{
  if(completion_routine)
    {
      IoCopyCurrentIrpStackLocationToNext(irp);
      IoSetCompletionRoutine(irp, completion_routine, context,
                             TRUE, TRUE, TRUE);
    }
  else
    {
      IoSkipCurrentIrpStackLocation(irp);
    }

  return IoCallDriver(dev->next_stack_device, irp);
}

bool_t accept_irp(libusb_device_t *dev, IRP *irp)
{
  /* check if the IRP is sent to libusb's device object or to */
  /* the lower one. This check is neccassary since the device object */
  /* might be a filter */
  if(irp->Tail.Overlay.OriginalFileObject)
    {
     return irp->Tail.Overlay.OriginalFileObject->DeviceObject
         == dev->self ? TRUE : FALSE;
    }

  return FALSE;
}

bool_t get_pipe_handle(libusb_device_t *dev, int endpoint_address, 
                       USBD_PIPE_HANDLE *pipe_handle)
{
  int i, j;

  *pipe_handle = NULL;

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_INTERFACES; i++)
    {
      if(dev->config.interfaces[i].valid)
        {
          for(j = 0; j < LIBUSB_MAX_NUMBER_OF_ENDPOINTS; j++)
            {
              if(dev->config.interfaces[i].endpoints[j].address 
                 == endpoint_address)
                {
                  *pipe_handle = dev->config.interfaces[i].endpoints[j].handle;
                  
                  return !*pipe_handle ? FALSE : TRUE;
                }
            }
        }
    }

  return FALSE;
}

void clear_pipe_info(libusb_device_t *dev)
{
  memset(dev->config.interfaces, 0 , sizeof(dev->config.interfaces));
}

bool_t update_pipe_info(libusb_device_t *dev,
                        USBD_INTERFACE_INFORMATION *interface_info)
{
  int i;
  int number;

  if(!interface_info)
    {
      return FALSE;
    }

  number = interface_info->InterfaceNumber;

  if(interface_info->InterfaceNumber >= LIBUSB_MAX_NUMBER_OF_INTERFACES)
    {
      return FALSE;
    }

  DEBUG_MESSAGE("update_pipe_info(): interface %d", number);

  dev->config.interfaces[number].valid = TRUE;

  for(i = 0; i < LIBUSB_MAX_NUMBER_OF_ENDPOINTS; i++)
    {
      dev->config.interfaces[number].endpoints[i].address = 0;
      dev->config.interfaces[number].endpoints[i].handle = NULL;
    } 

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

          dev->config.interfaces[number].endpoints[i].handle
            = interface_info->Pipes[i].PipeHandle;	
          dev->config.interfaces[number].endpoints[i].address = 
            interface_info->Pipes[i].EndpointAddress;
        }
    }

  return TRUE;
}


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


NTSTATUS remove_lock_acquire(libusb_device_t *dev)
{
  InterlockedIncrement(&dev->remove_lock.usage_count);

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


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


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


USB_INTERFACE_DESCRIPTOR *
find_interface_desc(USB_CONFIGURATION_DESCRIPTOR *config_desc,
                    unsigned int size, int interface_number, int altsetting)
{
  usb_descriptor_header_t *desc = (usb_descriptor_header_t *)config_desc;
  char *p = (char *)desc;
  USB_INTERFACE_DESCRIPTOR *if_desc = NULL;

  if(!config_desc || (size < config_desc->wTotalLength))
    return NULL;

  while(size && desc->length <= size)
    {
      if(desc->type == USB_INTERFACE_DESCRIPTOR_TYPE)
        {
          if_desc = (USB_INTERFACE_DESCRIPTOR *)desc;

          if((if_desc->bInterfaceNumber == (UCHAR)interface_number)
             && (if_desc->bAlternateSetting == (UCHAR)altsetting))
          {
            return if_desc;
          }
        }

      size -= desc->length;
      p += desc->length;
      desc = (usb_descriptor_header_t *)p;
    }

  return NULL;
}