common.c File Reference

#include "wdfloader.h"

Include dependency graph for common.c:

Go to the source code of this file.

Functions
VOID	FxLdrAcquireLoadedModuleLock (VOID)
VOID	FxLdrReleaseLoadedModuleLock (VOID)
VOID	GetNameFromPath (_In_ PCUNICODE_STRING Path, _Out_ PUNICODE_STRING Name)
NTSTATUS	GetImageName (_In_ PCUNICODE_STRING ServicePath, _Out_ PUNICODE_STRING ImageName)
NTSTATUS	GetImageInfo (_In_ PCUNICODE_STRING ImageName, _Out_ PVOID *ImageBase, _Out_ PULONG ImageSize)

Function Documentation

FxLdrAcquireLoadedModuleLock()

VOID FxLdrAcquireLoadedModuleLock

(

VOID

)

Definition at line 13 of file common.c.

{
    KeEnterCriticalRegion();
    ExAcquireResourceExclusiveLite(&WdfLdrGlobals.LoadedModulesListLock, TRUE);
}

Referenced by ClassRemoveFromLibraryList(), LibraryDereference(), LibraryFindOrLoad(), LibraryReference(), ReferenceClassVersion(), WdfRegisterClassLibrary(), and WdfRegisterLibrary().

FxLdrReleaseLoadedModuleLock()

VOID FxLdrReleaseLoadedModuleLock

(

VOID

)

Definition at line 20 of file common.c.

{
    ExReleaseResourceLite(&WdfLdrGlobals.LoadedModulesListLock);
    KeLeaveCriticalRegion();
}

Referenced by ClassRemoveFromLibraryList(), LibraryDereference(), LibraryFindOrLoad(), LibraryReference(), ReferenceClassVersion(), WdfRegisterClassLibrary(), and WdfRegisterLibrary().

GetImageInfo()

NTSTATUS GetImageInfo	(	_In_ PCUNICODE_STRING	ImageName,
		_Out_ PVOID *	ImageBase,
		_Out_ PULONG	ImageSize
	)

Definition at line 182 of file common.c.

{
    ANSI_STRING ansiImageName;
    NTSTATUS status;
 
    status = RtlUnicodeStringToAnsiString(&ansiImageName, ImageName, TRUE);
 
    if (!NT_SUCCESS(status))
    {
        __DBGPRINT(("ERROR: RtlUnicodeStringToAnsiString failed with Status 0x%x\n", status));
        return status;
    }
 
    PAUX_MODULE_EXTENDED_INFO modulesBuffer;
    ULONG modulesSize;
    for (;;)
    {
        status = AuxKlibQueryModuleInformation(&modulesSize,
                                               sizeof(AUX_MODULE_EXTENDED_INFO),
                                               NULL);
        if (!NT_SUCCESS(status))
        {
            goto clean;
        }
 
        modulesBuffer = ExAllocatePoolZero(PagedPool, modulesSize, WDFLDR_TAG);
        if (modulesBuffer == NULL)
        {
            status = STATUS_INSUFFICIENT_RESOURCES;
            __DBGPRINT(("ERROR: ExAllocatePoolWithTag failed\n"));
 
            goto clean;
        }
 
        status = AuxKlibQueryModuleInformation(&modulesSize,
                                               sizeof(AUX_MODULE_EXTENDED_INFO),
                                               modulesBuffer);
        if (status == STATUS_BUFFER_TOO_SMALL)
        {
            ExFreePoolWithTag(modulesBuffer, WDFLDR_TAG);
            continue;
        }
        else
        {
            break;
        }
    }
 
    if (NT_SUCCESS(status))
    {
        for (SIZE_T i = 0; i < modulesSize / sizeof(AUX_MODULE_EXTENDED_INFO); i++)
        {
            // Compare our image name to names returned by AuxKlib
            if (modulesBuffer[i].FileNameOffset < AUX_KLIB_MODULE_PATH_LEN &&
                _strnicmp(&modulesBuffer[i].FullPathName[modulesBuffer[i].FileNameOffset],
                          ansiImageName.Buffer, ansiImageName.Length) == 0)
            {
                *ImageBase = modulesBuffer[i].BasicInfo.ImageBase;
                *ImageSize = modulesBuffer[i].ImageSize;
                break;
            }
        }
    }
    else
    {
        __DBGPRINT(("ERROR: AuxKlibQueryModuleInformation failed with Status 0x%x\n", status));
    }
 
    ExFreePoolWithTag(modulesBuffer, WDFLDR_TAG);
 
clean:
    RtlFreeAnsiString(&ansiImageName);
    return status;
}

Referenced by ClassCreate(), DECLARE_INTERFACE_(), LibraryLinkInClient(), and WdfRegisterLibrary().

GetImageName()

NTSTATUS GetImageName	(	_In_ PCUNICODE_STRING	ServicePath,
		_Out_ PUNICODE_STRING	ImageName
	)

Definition at line 76 of file common.c.

{
    NTSTATUS status;
    OBJECT_ATTRIBUTES objectAttributes;
    UNICODE_STRING name;
    UNICODE_STRING path;
    PKEY_VALUE_PARTIAL_INFORMATION pKeyValPartial = NULL;
    HANDLE keyHandle = NULL;
    UNICODE_STRING valueName = RTL_CONSTANT_STRING(L"ImagePath");
 
    InitializeObjectAttributes(&objectAttributes,
                               (PUNICODE_STRING)ServicePath,
                               OBJ_KERNEL_HANDLE | OBJ_CASE_INSENSITIVE,
                               NULL,
                               NULL);
 
    status = ZwOpenKey(&keyHandle, KEY_READ, &objectAttributes);
 
    if (!NT_SUCCESS(status))
    {
        __DBGPRINT(("ERROR: GetImageName failed with status 0x%x\n", status));
        return status;
    }
 
    status = FxLdrQueryData(keyHandle, &valueName, WDFLDR_TAG, &pKeyValPartial);
    if (!NT_SUCCESS(status))
    {
        __DBGPRINT(("ERROR: GetImageName failed with status 0x%x\n", status));
        return status;
    }
 
    if (pKeyValPartial->Type != REG_SZ &&
        pKeyValPartial->Type != REG_EXPAND_SZ)
    {
        status = STATUS_OBJECT_TYPE_MISMATCH;
        __DBGPRINT(("ERROR: GetImageName failed with status 0x%x\n", status));
    }
 
    if (pKeyValPartial->DataLength == 0 ||
        pKeyValPartial->DataLength > 0xFFFF)
    {
        status = STATUS_INVALID_PARAMETER;
        __DBGPRINT(("ERROR: GetImageName failed with status 0x%x\n", status));
    }
 
    path.Buffer = (PWCH)pKeyValPartial->Data;
    path.Length = (USHORT)pKeyValPartial->DataLength;
    path.MaximumLength = (USHORT)pKeyValPartial->DataLength;
 
    if (pKeyValPartial->DataLength >= sizeof(WCHAR) &&
        !*(((WCHAR*)&pKeyValPartial->Data) + pKeyValPartial->DataLength / sizeof(WCHAR)))
    {
        path.Length = (USHORT)pKeyValPartial->DataLength - sizeof(WCHAR);
    }
 
    GetNameFromPath(&path, &name);
 
    if (name.Length == 0)
    {
        status = STATUS_INVALID_PARAMETER;
        __DBGPRINT(("ERROR: GetNameFromPathW could not find a name, status 0x%x\n", status));
        goto clean;
    }
 
    status = RtlUShortAdd(name.Length, 2, &ImageName->Length);
 
    if (!NT_SUCCESS(status))
    {
        status = STATUS_INTEGER_OVERFLOW;
        __DBGPRINT(("ERROR: size computation failed with Status 0x%x\n", status));
        goto clean;
    }
 
    ImageName->Buffer = ExAllocatePoolWithTag(PagedPool, ImageName->Length, WDFLDR_TAG);
 
    if (ImageName->Buffer != NULL)
    {
        RtlZeroMemory(ImageName->Buffer, ImageName->Length);
        ImageName->MaximumLength = ImageName->Length;
        ImageName->Length = 0;
        RtlCopyUnicodeString(ImageName, &name);
 
        __DBGPRINT(("Version Image Name \"%wZ\"\n", ImageName));
    }
    else
    {
        status = STATUS_INSUFFICIENT_RESOURCES;
        __DBGPRINT(("ERROR: ExAllocatePoolWithTag failed with Status 0x%x\n", status));
    }
 
clean:
    if (keyHandle)
    {
        ZwClose(keyHandle);
    }
    if (pKeyValPartial)
    {
        ExFreePoolWithTag(pKeyValPartial, WDFLDR_TAG);
    }
 
    return status;
}

GetNameFromPath()

VOID GetNameFromPath	(	_In_ PCUNICODE_STRING	Path,
		_Out_ PUNICODE_STRING	Name
	)

Definition at line 27 of file common.c.

{
    PWCHAR pNextSym;
    PWCHAR pCurrSym;
 
    if (Path->Length < sizeof(WCHAR))
    {
        Name->Length = 0;
        Name->Buffer = NULL;
        return;
    }
 
    Name->Buffer = Path->Buffer + (Path->Length / 2) - 1;
    Name->Length = sizeof(WCHAR);
 
    for (pNextSym = Name->Buffer; ; Name->Buffer = pNextSym)
    {
        if (pNextSym < Path->Buffer)
        {
            Name->Length -= sizeof(WCHAR);
            ++Name->Buffer;
            goto end;
        }
        pCurrSym = Name->Buffer;
 
        if (*pCurrSym == '\\')
        {
            break;
        }
        pNextSym = pCurrSym - 1;
        Name->Length += sizeof(WCHAR);
    }
 
    ++Name->Buffer;
    Name->Length -= sizeof(WCHAR);
 
    if (Name->Length == sizeof(WCHAR))
    {
        Name->Buffer = NULL;
        Name->Length = 0;
    }
 
end:
    Name->MaximumLength = Name->Length;
}

Referenced by _Requires_lock_held_(), FindClassByServiceNameLocked(), FxLibraryCommonRegisterClient(), and GetImageName().