USB filter!

  我做了一个usb的类过滤驱动，是lowerfilters的，挂在
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\
Class\{36FC9E60-C465-11CF-8056-444553540000}
的下面。主要功能是可以动态开关usb接口。

遇到一点问题，如果我在开机的时候就卡死一些irp消息，那么
usb的hub也不能顺利的加载，这样就不能对usb接口进行动态开关。

而如果我在开机的时候不阻拦irp，只有在接受到上层程序的
通知的情况下，我开始阻拦某些irp消息，实验证明是可行的。

但是带来一个问题，如果别人开机时候就挂着u盘，那么，我就不能够
控制这个u盘了。

我想问的是，在filter（我是用general\toaster中filter进行修改的）
如何区分对待usb hub、usb 鼠标、usb mess stor设备？

谢谢。

判断 deviceobject 的devicetype


Specifying Device Types
Each device object has a device type, which is stored in the DeviceType member of its DEVICE_OBJECT structure. The device type represents the type of underlying hardware for the driver.

Every kernel-mode driver that creates a device object must specify an appropriate device type value when calling IoCreateDevice. The IoCreateDevice routine uses the supplied device type to initialize the DeviceType member of the DEVICE_OBJECT structure.

The system defines the following device type values, listed in alphabetical order:

#define FILE_DEVICE_8042_PORT           0x00000027
#define FILE_DEVICE_ACPI                0x00000032
#define FILE_DEVICE_BATTERY             0x00000029
#define FILE_DEVICE_BEEP                0x00000001
#define FILE_DEVICE_BUS_EXTENDER        0x0000002a
#define FILE_DEVICE_CD_ROM              0x00000002
#define FILE_DEVICE_CD_ROM_FILE_SYSTEM  0x00000003
#define FILE_DEVICE_CHANGER             0x00000030
#define FILE_DEVICE_CONTROLLER          0x00000004
#define FILE_DEVICE_DATALINK            0x00000005
#define FILE_DEVICE_DFS                 0x00000006
#define FILE_DEVICE_DFS_FILE_SYSTEM     0x00000035
#define FILE_DEVICE_DFS_VOLUME          0x00000036
#define FILE_DEVICE_DISK                0x00000007
#define FILE_DEVICE_DISK_FILE_SYSTEM    0x00000008
#define FILE_DEVICE_DVD                 0x00000033
#define FILE_DEVICE_FILE_SYSTEM         0x00000009
#define FILE_DEVICE_FIPS                0x0000003a
#define FILE_DEVICE_FULLSCREEN_VIDEO    0x00000034
#define FILE_DEVICE_INPORT_PORT         0x0000000a
#define FILE_DEVICE_KEYBOARD            0x0000000b
#define FILE_DEVICE_KS                  0x0000002f
#define FILE_DEVICE_KSEC                0x00000039
#define FILE_DEVICE_MAILSLOT            0x0000000c
#define FILE_DEVICE_MASS_STORAGE        0x0000002d
#define FILE_DEVICE_MIDI_IN             0x0000000d
#define FILE_DEVICE_MIDI_OUT            0x0000000e
#define FILE_DEVICE_MODEM               0x0000002b
#define FILE_DEVICE_MOUSE               0x0000000f
#define FILE_DEVICE_MULTI_UNC_PROVIDER  0x00000010
#define FILE_DEVICE_NAMED_PIPE          0x00000011
#define FILE_DEVICE_NETWORK             0x00000012
#define FILE_DEVICE_NETWORK_BROWSER     0x00000013
#define FILE_DEVICE_NETWORK_FILE_SYSTEM 0x00000014
#define FILE_DEVICE_NETWORK_REDIRECTOR  0x00000028
#define FILE_DEVICE_NULL                0x00000015
#define FILE_DEVICE_PARALLEL_PORT       0x00000016
#define FILE_DEVICE_PHYSICAL_NETCARD    0x00000017
#define FILE_DEVICE_PRINTER             0x00000018
#define FILE_DEVICE_SCANNER             0x00000019
#define FILE_DEVICE_SCREEN              0x0000001c
#define FILE_DEVICE_SERENUM             0x00000037
#define FILE_DEVICE_SERIAL_MOUSE_PORT   0x0000001a
#define FILE_DEVICE_SERIAL_PORT         0x0000001b
#define FILE_DEVICE_SMARTCARD           0x00000031
#define FILE_DEVICE_SMB                 0x0000002e
#define FILE_DEVICE_SOUND               0x0000001d
#define FILE_DEVICE_STREAMS             0x0000001e
#define FILE_DEVICE_TAPE                0x0000001f
#define FILE_DEVICE_TAPE_FILE_SYSTEM    0x00000020
#define FILE_DEVICE_TERMSRV             0x00000038
#define FILE_DEVICE_TRANSPORT           0x00000021
#define FILE_DEVICE_UNKNOWN             0x00000022
#define FILE_DEVICE_VDM                 0x0000002c
#define FILE_DEVICE_VIDEO               0x00000023
#define FILE_DEVICE_VIRTUAL_DISK        0x00000024
#define FILE_DEVICE_WAVE_IN             0x00000025
#define FILE_DEVICE_WAVE_OUT            0x00000026


These constants are defined in ntddk.h and wdm.h. Check these files to see if additional device types have been defined.

The FILE_DEVICE_DISK specification covers both floppy and fixed-disk devices, as well as disk partitions.

Intermediate drivers usually specify device types that represent the underlying device. For example, the system-supplied fault-tolerant disk driver, ftdisk, creates device objects of type FILE_DEVICE_DISK; it does not define new device types for the mirror sets, stripe sets, and volume sets it manages.

FILE_DEVICE_XXX values in the range of 0 through 32767 are reserved for Microsoft. All driver writers must use these system-defined constants for devices belonging to the system-defined device types.

If a type of hardware does not match any of the defined types, specify a value of either FILE_DEVICE_UNKNOWN, or a value within the range of 32768 through 65535.