346 lines
13 KiB
C
346 lines
13 KiB
C
/*++
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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loadunld.c
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Abstract:
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This module contains the code to implement the NtLoadDriver and
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NtUnLoadDriver system services for the NT I/O system.
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Author:
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Darryl E. Havens (darrylh) 5-Apr-1992
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Environment:
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Kernel mode only
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--*/
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#include "iop.h"
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, NtLoadDriver)
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#pragma alloc_text(PAGE, NtUnloadDriver)
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#endif
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NTSTATUS NtLoadDriver(IN PUNICODE_STRING DriverServiceName)
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/*++
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Routine Description:
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This service dynamically loads a device or file system driver into
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the currently running system. It requires that the caller have the
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appropriate privilege to execute this service.
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Arguments:
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DriverServiceName - Specifies the name of the node in the registry associated with the driver to be loaded.
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Return Value:
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The status returned is the final completion status of the load operation.
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--*/
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{
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KPROCESSOR_MODE requestorMode;
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UNICODE_STRING driverServiceName;
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PWCHAR nameBuffer = (PWCHAR)NULL;
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LOAD_PACKET loadPacket;
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PAGED_CODE();
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// Get the previous mode; i.e., the mode of the caller.
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requestorMode = KeGetPreviousMode();
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if (requestorMode != KernelMode) {
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// The caller's access mode is not kernel so check to ensure that
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// the caller has the privilege to load a driver and probe and
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// capture the name of the driver service entry.
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if (!SeSinglePrivilegeCheck(SeLoadDriverPrivilege, requestorMode)) {
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return STATUS_PRIVILEGE_NOT_HELD;
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}
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// The caller has the appropriate privilege to load and unload
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// drivers, so capture the driver service name string so that it
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// can be used to locate the driver from the registry node.
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try {
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driverServiceName = ProbeAndReadUnicodeString(DriverServiceName);
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if (!driverServiceName.Length) {
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return STATUS_INVALID_PARAMETER;
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}
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ProbeForRead(driverServiceName.Buffer, driverServiceName.Length, sizeof(WCHAR));
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nameBuffer = ExAllocatePoolWithQuota(PagedPool, driverServiceName.Length);
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RtlCopyMemory(nameBuffer, driverServiceName.Buffer, driverServiceName.Length);
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driverServiceName.Buffer = nameBuffer;
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} except(EXCEPTION_EXECUTE_HANDLER)
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{
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// An exception was incurred while attempting to capture the
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// input name string or while attempting to allocate the name
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// string buffer. Simply clean everything up and return an
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// appropriate error status code.
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if (nameBuffer) {
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ExFreePool(nameBuffer);
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}
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return GetExceptionCode();
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}
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} else {
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driverServiceName = *DriverServiceName;
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}
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// Because drivers may wish to create a system thread and execute in
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// its context, the remainder of this service must be executed in the
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// context of the primary system process. This is accomplished by
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// queueing a request to one of the EX worker threads and having it
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// invoke the I/O system routine to complete this work.
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// Fill in a request packet and queue it to the worker thread then, so
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// that it can actually do the load.
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KeInitializeEvent(&loadPacket.Event, NotificationEvent, FALSE);
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loadPacket.DriverObject = (PDRIVER_OBJECT)NULL;
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loadPacket.DriverServiceName = &driverServiceName;
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if (PsGetCurrentProcess() == PsInitialSystemProcess) {
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// If we are already in the system process, just use this thread.
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IopLoadUnloadDriver(&loadPacket);
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} else {
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ExInitializeWorkItem(&loadPacket.WorkQueueItem, IopLoadUnloadDriver, &loadPacket);
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ExQueueWorkItem(&loadPacket.WorkQueueItem, DelayedWorkQueue);
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KeWaitForSingleObject(&loadPacket.Event, UserRequest, KernelMode, FALSE, (PLARGE_INTEGER)NULL);
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}
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// The load operation is now complete. If a name buffer was allocated,
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// deallocate it now, and return the final status of the load operation.
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if (nameBuffer) {
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ExFreePool(nameBuffer);
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}
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return loadPacket.FinalStatus;
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}
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NTSTATUS IopCheckUnloadDriver(IN PDRIVER_OBJECT driverObject, OUT PBOOLEAN unloadDriver)
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{
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PDEVICE_OBJECT deviceObject;
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KIRQL irql;
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// Check to see whether the driver has already been marked for an unload
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// operation by anyone in the past.
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ExAcquireSpinLock(&IopDatabaseLock, &irql);
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if ((driverObject->DeviceObject == NULL &&
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(driverObject->Flags & DRVO_UNLOAD_INVOKED)) ||
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(driverObject->DeviceObject &&
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driverObject->DeviceObject->DeviceObjectExtension->ExtensionFlags
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& DOE_UNLOAD_PENDING)) {
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// The driver has already been marked for unload or is being
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// unloaded. Simply return a successful completion status since
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// the driver is on its way out and therefore has been "marked for
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// unload".
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ExReleaseSpinLock(&IopDatabaseLock, irql);
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ObDereferenceObject(driverObject);
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return STATUS_SUCCESS;
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}
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// The driver exists, and it implements unload, and it has not, so far,
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// been marked for an unload operation. Simply mark all of the devices
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// that the driver owns as being marked for unload. While this is going
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// on, count the references for each of the devices. If all of the
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// devices have a zero reference count, then tell the driver that it
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// should unload itself.
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deviceObject = driverObject->DeviceObject;
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*unloadDriver = TRUE;
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while (deviceObject) {
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deviceObject->DeviceObjectExtension->ExtensionFlags |= DOE_UNLOAD_PENDING;
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if (deviceObject->ReferenceCount || deviceObject->AttachedDevice) {
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*unloadDriver = FALSE;
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}
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deviceObject = deviceObject->NextDevice;
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}
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if (*unloadDriver) {
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driverObject->Flags |= DRVO_UNLOAD_INVOKED;
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}
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ExReleaseSpinLock(&IopDatabaseLock, irql);
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return STATUS_UNSUCCESSFUL;
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}
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NTSTATUS NtUnloadDriver(IN PUNICODE_STRING DriverServiceName)
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/*++
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Routine Description:
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This service dynamically unloads a device or file system driver from the currently running system.
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It requires that the caller have the appropriate privilege to execute this service.
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Arguments:
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DriverServiceName - Specifies the name of the node in the registry associated with the driver to be unloaded.
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Return Value:
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The status returned is the final completion status of the operation.
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--*/
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{
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KPROCESSOR_MODE requestorMode;
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UNICODE_STRING driverServiceName;
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PWCHAR nameBuffer = (PWCHAR)NULL;
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NTSTATUS status;
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OBJECT_ATTRIBUTES objectAttributes;
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HANDLE keyHandle;
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UNICODE_STRING driverName;
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HANDLE driverHandle;
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PDRIVER_OBJECT driverObject;
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BOOLEAN unloadDriver;
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PAGED_CODE();
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// Get the previous mode; i.e., the mode of the caller.
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requestorMode = KeGetPreviousMode();
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if (requestorMode != KernelMode) {
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// The caller's access mode is not kernel so check to ensure that
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// the caller has the privilege to unload a driver and probe and
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// capture the name of the driver service entry.
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if (!SeSinglePrivilegeCheck(SeLoadDriverPrivilege, requestorMode)) {
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return STATUS_PRIVILEGE_NOT_HELD;
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}
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// The caller has the appropriate privilege to load and unload
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// drivers, so capture the driver service name string so that it
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// can be used to locate the driver from the registry node.
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try {
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driverServiceName = ProbeAndReadUnicodeString(DriverServiceName);
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if (!driverServiceName.Length) {
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return STATUS_INVALID_PARAMETER;
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}
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ProbeForRead(driverServiceName.Buffer, driverServiceName.Length, sizeof(WCHAR));
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nameBuffer = ExAllocatePoolWithQuota(PagedPool, driverServiceName.Length);
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RtlCopyMemory(nameBuffer, driverServiceName.Buffer, driverServiceName.Length);
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driverServiceName.Buffer = nameBuffer;
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} except(EXCEPTION_EXECUTE_HANDLER)
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{
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// An exception was incurred while attempting to capture the
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// input name string or while attempting to allocate the name
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// string buffer. Simply clean everything up and return an
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// appropriate error status code.
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if (nameBuffer) {
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ExFreePool(nameBuffer);
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}
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return GetExceptionCode();
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}
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// Now that the caller's parameters have been captured and everything
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// appears to have checked out, actually attempt to unload the driver.
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// This is done with a previous mode of kernel so that drivers will
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// not fail to unload because the caller didn't happen to have access
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// to some resource that the driver needs in order to complete its
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// unload operation.
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status = ZwUnloadDriver(&driverServiceName);
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ExFreePool(nameBuffer);
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return status;
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}
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// The caller's mode is now kernel mode. Attempt to actually unload the
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// driver specified by the indicated registry node. Begin by opening
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// the registry node for this driver.
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status = IopOpenRegistryKey(&keyHandle,
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(HANDLE)NULL,
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DriverServiceName,
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KEY_READ,
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FALSE);
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if (!NT_SUCCESS(status)) {
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return status;
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}
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// Get the optional object name for this driver from the value for this key.
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// If one exists, then its name overrides the default name of the driver.
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status = IopGetDriverNameFromKeyNode(keyHandle, &driverName);
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NtClose(keyHandle);
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if (!NT_SUCCESS(status)) {
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return status;
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}
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// Now attempt to open the driver object for the specified driver.
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InitializeObjectAttributes(&objectAttributes,
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&driverName,
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OBJ_CASE_INSENSITIVE,
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(HANDLE)NULL,
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(PSECURITY_DESCRIPTOR)NULL);
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status = ObOpenObjectByName(&objectAttributes,
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IoDriverObjectType,
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KernelMode,
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NULL,
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FILE_READ_DATA,
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(PVOID)NULL,
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&driverHandle);
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// Perform some common cleanup by getting rid of buffers that have been
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// allocated up to this point so that error conditions do not have as
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// much work to do on each exit path.
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ExFreePool(driverName.Buffer);
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// If the driver object could not be located in the first place, then
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// return now before attempting to do anything else.
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if (!NT_SUCCESS(status)) {
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return status;
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}
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// The driver object was located, so convert the handle into a pointer
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// so that the driver object itself can be examined.
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status = ObReferenceObjectByHandle(driverHandle,
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0,
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IoDriverObjectType,
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KernelMode,
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(PVOID *)&driverObject,
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NULL);
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NtClose(driverHandle);
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if (!NT_SUCCESS(status)) {
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return status;
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}
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// Check to see whether or not this driver implements unload. Also,
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// if the driver has no section associated with it, then it was loaded
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// be the OS loader and therefore cannot be unloaded. If either is true,
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// return an appropriate error status code.
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if (driverObject->DriverUnload == (PDRIVER_UNLOAD)NULL || !driverObject->DriverSection) {
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ObDereferenceObject(driverObject);
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return STATUS_INVALID_DEVICE_REQUEST;
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}
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// Check to see whether the driver has already been marked for an unload operation by anyone in the past.
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status = IopCheckUnloadDriver(driverObject, &unloadDriver);
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if (NT_SUCCESS(status)) {
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return status;
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}
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if (unloadDriver) {
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if (PsGetCurrentProcess() == PsInitialSystemProcess) {
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// The current thread is alrady executing in the context of the
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// system process, so simply invoke the driver's unload routine.
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driverObject->DriverUnload(driverObject);
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} else {
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// The current thread is not executing in the context of the system
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// process, which is required in order to invoke the driver's unload
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// routine. Queue a worker item to one of the worker threads to
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// get into the appropriate process context and then invoke the routine.
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LOAD_PACKET loadPacket;
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KeInitializeEvent(&loadPacket.Event, NotificationEvent, FALSE);
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loadPacket.DriverObject = driverObject;
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ExInitializeWorkItem(&loadPacket.WorkQueueItem, IopLoadUnloadDriver, &loadPacket);
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ExQueueWorkItem(&loadPacket.WorkQueueItem, DelayedWorkQueue);
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(VOID)KeWaitForSingleObject(&loadPacket.Event,
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Executive,
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KernelMode,
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FALSE,
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(PLARGE_INTEGER)NULL);
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}
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ObMakeTemporaryObject(driverObject);
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ObDereferenceObject(driverObject);
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}
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// The driver has either been unloaded, or it has successfully been marked for an unload operation.
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// Simply dereference the pointer to the object and return success.
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ObDereferenceObject(driverObject);
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return STATUS_SUCCESS;
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}
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