Source code of Windows XP (NT5)
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137 lines
2.9 KiB

/*++
Copyright (c) 2000 Microsoft Corporation
Module Name:
EmulateWriteFile.cpp
Abstract:
On NT, WriteFile requires the buffer passed in to be non-null. But Win9x
assumes you want to write zeroes if the buffer is NULL. This shim emulates
the Win9x behavior.
Notes:
This is a general purpose shim.
History:
01/21/2000 linstev Created
--*/
#include "precomp.h"
IMPLEMENT_SHIM_BEGIN(EmulateWriteFile)
#include "ShimHookMacro.h"
APIHOOK_ENUM_BEGIN
APIHOOK_ENUM_ENTRY(WriteFile)
APIHOOK_ENUM_ENTRY(AVIStreamWrite)
APIHOOK_ENUM_END
typedef HRESULT (*_pfn_AVIStreamWrite)(PAVISTREAM pavi, LONG lStart, LONG lSamples, LPVOID lpBuffer, LONG cbBuffer, DWORD dwFlags, LONG * plSampWritten, LONG * plBytesWritten);
/*++
Allocate a buffer as required.
--*/
BOOL
APIHOOK(WriteFile)(
HANDLE hFile,
LPCVOID lpBuffer,
DWORD nNumberOfBytesToWrite,
LPDWORD lpNumberOfBytesWritten,
LPOVERLAPPED lpOverlapped
)
{
BOOL bRet;
if (!lpBuffer) {
void* pBuf = malloc(nNumberOfBytesToWrite);
if (pBuf == NULL) {
LOGN(eDbgLevelError, "[WriteFile] Failed to allocate %d bytes.", nNumberOfBytesToWrite);
} else {
ZeroMemory(pBuf, nNumberOfBytesToWrite);
}
bRet = ORIGINAL_API(WriteFile)(hFile, pBuf, nNumberOfBytesToWrite,
lpNumberOfBytesWritten, lpOverlapped);
free(pBuf);
LOGN(eDbgLevelError, "[WriteFile] - null buffer of size %d.", nNumberOfBytesToWrite);
} else {
bRet = ORIGINAL_API(WriteFile)(hFile, lpBuffer, nNumberOfBytesToWrite,
lpNumberOfBytesWritten, lpOverlapped);
}
return bRet;
}
/*++
Allocate a buffer as required.
--*/
HRESULT
APIHOOK(AVIStreamWrite)(
PAVISTREAM pavi,
LONG lStart,
LONG lSamples,
LPVOID lpBuffer,
LONG cbBuffer,
DWORD dwFlags,
LONG * plSampWritten,
LONG * plBytesWritten
)
{
HRESULT hRet;
if (!lpBuffer) {
void* pBuf = malloc(cbBuffer);
if (pBuf == NULL) {
LOGN(eDbgLevelError, "[AVIStreamWrite] Failed to allocate %d bytes.", cbBuffer);
} else {
ZeroMemory(pBuf, cbBuffer);
}
hRet = ORIGINAL_API(AVIStreamWrite)(pavi, lStart, lSamples, pBuf,
cbBuffer, dwFlags, plSampWritten, plBytesWritten);
free(pBuf);
LOGN(eDbgLevelError, "[AVIStreamWrite] - null buffer of size %d", cbBuffer);
} else {
hRet = ORIGINAL_API(AVIStreamWrite)(pavi, lStart, lSamples, lpBuffer,
cbBuffer, dwFlags, plSampWritten, plBytesWritten);
}
return hRet;
}
/*++
Register hooked functions
--*/
HOOK_BEGIN
APIHOOK_ENTRY(KERNEL32.DLL, WriteFile)
APIHOOK_ENTRY(AVIFIL32.DLL, AVIStreamWrite)
HOOK_END
IMPLEMENT_SHIM_END