[소스분석] WDF sample source - Osrubsfx2 : driver.c

// // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // //

// driver.c

// 함수 : DriverEntry(),

             OsrFxEvtDriverContextCleanup(),

             TraceEvents()

// // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // //

#include <osrusbfx2.h>

#if defined(EVENT_TRACING)
//
// The trace message header (.tmh) file must be included in a source file
// before any WPP macro calls and after defining a WPP_CONTROL_GUIDS
// macro (defined in toaster.h). During the compilation, WPP scans the source
// files for DoTraceMessage() calls and builds a .tmh file which stores a unique
// data GUID for each message, the text resource string for each message,
// and the data types of the variables passed in for each message.  This file
// is automatically generated and used during post-processing.
//
#include "driver.tmh"
#else
ULONG DebugLevel = TRACE_LEVEL_INFORMATION;
ULONG DebugFlag = 0xff;
#endif

#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT, DriverEntry)
#pragma alloc_text(PAGE, OsrFxEvtDriverContextCleanup)
#endif

 

// DriverEntry는 드라이버를 초기화하고,  드라이버가 로드된 후에 시스템으로부터 불려지는 첫번째 루틴이다.

__drv_requiresIRQL(PASSIVE_LEVEL)

NTSTATUS
DriverEntry(
    __in PDRIVER_OBJECT  DriverObject,
    __in PUNICODE_STRING RegistryPath
    )
/*++

Routine Description:

 

Parameters Description:

    DriverObject - represents the instance of the function driver that is loaded
    into memory. DriverEntry must initialize members of DriverObject before it
    returns to the caller. DriverObject is allocated by the system before the
    driver is loaded, and it is released by the system after the system unloads
    the function driver from memory.

    RegistryPath - represents the driver specific path in the Registry.
    The function driver can use the path to store driver related data between
    reboots. The path does not store hardware instance specific data.

Return Value:

    STATUS_SUCCESS if successful,
    STATUS_UNSUCCESSFUL otherwise.

--*/
{
    WDF_DRIVER_CONFIG       config;
    NTSTATUS                status;
    WDF_OBJECT_ATTRIBUTES   attributes;             // object 속성

    //
    // Initialize WPP Tracing
    //
    WPP_INIT_TRACING( DriverObject, RegistryPath );

    TraceEvents(TRACE_LEVEL_INFORMATION, DBG_INIT,
                       "OSRUSBFX2 Driver Sample - Driver Framework Edition.\n");

    TraceEvents(TRACE_LEVEL_INFORMATION, DBG_INIT,
                "Built %s %s\n", __DATE__, __TIME__);

    //
    // Initiialize driver config to control the attributes that
    // are global to the driver. Note that framework by default
    // provides a driver unload routine. If you create any resources
    // in the DriverEntry and want to be cleaned in driver unload,
    // you can override that by manually setting the EvtDriverUnload in the
    // config structure. In general xxx_CONFIG_INIT macros are provided to
    // initialize most commonly used members.
    //

    WDF_DRIVER_CONFIG_INIT(     // WDF_DRIVER_CONFIG 구조체 초기화
        &config,
        OsrFxEvtDeviceAdd      // device.c 함수
        );

    //
    // Register a cleanup callback so that we can call WPP_CLEANUP when
    // the framework driver object is deleted during driver unload.
    //
    WDF_OBJECT_ATTRIBUTES_INIT(&attributes);
    attributes.EvtCleanupCallback = OsrFxEvtDriverContextCleanup;

    //
    // Create a framework driver object to represent our driver.
    //
    status = WdfDriverCreate(       // Framework Driver Object 생성
        DriverObject,
        RegistryPath,
        &attributes,  // Driver Object Attributes  이 둘은 생성하고자 하는 object 작동방식을
        &config,          // Driver Config Info         설정하는 파라미터이다.
        WDF_NO_HANDLE // hDriver
        );

    if (!NT_SUCCESS(status)) {

        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
                "WdfDriverCreate failed with status 0x%x\n", status);
        //
        // Cleanup tracing here because DriverContextCleanup will not be called
        // as we have failed to create WDFDRIVER object itself.
        // Please note that if your return failure from DriverEntry after the
        // WDFDRIVER object is created successfully, you don't have to
        // call WPP cleanup because in those cases DriverContextCleanup
        // will be executed when the framework deletes the DriverObject.
        //
        WPP_CLEANUP(DriverObject);
    }

    return status;
}

VOID
OsrFxEvtDriverContextCleanup(
    __in WDFDRIVER Driver
    )
/*++
Routine Description:

    DriverEntry 안에 할당된 리소스를 해제한다.  

Arguments:

    Driver - handle to a WDF Driver object.

Return Value:

    VOID.

--*/
{
    PAGED_CODE ();    // 특정 함수가 IRQL DISPATCH_LEBEL 또는 그 이상의 IRQL 레벨에서 동작하지 않으면

                                      // Assert를 발생해주는 매크로

    UNREFERENCED_PARAMETER(Driver);      // Driver 파라미터를 이 함수에서 참조하지 않는다.

    TraceEvents(TRACE_LEVEL_INFORMATION, DBG_INIT,
                    "--> OsrFxEvtDriverContextCleanup\n");

    WPP_CLEANUP( WdfDriverWdmGetDriverObject( Driver ));

}

#if !defined(EVENT_TRACING)

VOID
TraceEvents (
    __in ULONG DebugPrintLevel,
    __in ULONG DebugPrintFlag,
    __drv_formatString(printf)
    __in PCSTR DebugMessage,
    ...
    )

/*++

Routine Description:

    Debug print for the sample driver.

Arguments:

    TraceEventsLevel - print level between 0 and 3, with 3 the most verbose

Return Value:

    None.

 --*/
 {
#if DBG
#define     TEMP_BUFFER_SIZE        1024
    va_list    list;
    CHAR       debugMessageBuffer[TEMP_BUFFER_SIZE];
    NTSTATUS   status;

    va_start(list, DebugMessage);

    if (DebugMessage) {

        //
        // Using new safe string functions instead of _vsnprintf.
        // This function takes care of NULL terminating if the message
        // is longer than the buffer.
        //
        status = RtlStringCbVPrintfA( debugMessageBuffer,
                                      sizeof(debugMessageBuffer),
                                      DebugMessage,
                                      list );
        if(!NT_SUCCESS(status)) {

            DbgPrint (_DRIVER_NAME_": RtlStringCbVPrintfA failed 0x%x\n", status);
            return;
        }
        if (DebugPrintLevel <= TRACE_LEVEL_ERROR ||
            (DebugPrintLevel <= DebugLevel &&
             ((DebugPrintFlag & DebugFlag) == DebugPrintFlag))) {
            DbgPrint("%s %s", _DRIVER_NAME_, debugMessageBuffer);
        }
    }
    va_end(list);

    return;
#else
    UNREFERENCED_PARAMETER(TraceEventsLevel);
    UNREFERENCED_PARAMETER(TraceEventsFlag);
    UNREFERENCED_PARAMETER(DebugMessage);
#endif
}

#endif