COMSAMP.CPP
#define INITGUID 1
#include <windows.h>
#include <olectl.h>
#include "comsamp.h"
TCHAR achSampleProgID[] = "comntv";
TCHAR achInprocServer32[] = "InprocServer32";
TCHAR achProgID[] = "ProgID";
TCHAR achThreadingModel[] = "ThreadingModel";
TCHAR achBoth[] = "Both";
DWORD g_ObjectCount = 0;
HINSTANCE ghInstance = 0;
VOID ObjectCreated(VOID)
{
InterlockedIncrement( (LONG*)&g_ObjectCount );
}
VOID ObjectDestroyed(VOID)
{
InterlockedDecrement( (LONG*)&g_ObjectCount );
}
HRESULT CheckJavaWriteAccess (BSTR pwszFilename)
{
// If there is no vm in the process, then we could not have
// been called directly from java code, and remote calls are
// implicitly trusted.
if (GetModuleHandle("MSJAVA") == NULL)
return S_OK;
HRESULT hr;
IMyCOMObjectSecurity *psecurity;
hr = CoCreateInstance(
CLSID_CMyCOMObjectSecurity,
NULL,
CLSCTX_ALL,
IID_IMyCOMObjectSecurity,
(PVOID*)&psecurity
);
if (SUCCEEDED(hr))
{
hr = psecurity->CheckRead(pwszFilename);
psecurity->Release();
// The VM does not convert SecurityException to a useful HRESULT, so do it here.
if (hr == E_FAIL)
hr = HRESULT_FROM_WIN32(ERROR_PRIVILEGE_NOT_HELD);
}
return hr;
}
class CMyCOMObject : public IMyInterface
{
ULONG refcount;
public:
CMyCOMObject ()
{
refcount = 1;
}
// IUnknown methods
HRESULT STDMETHODCALLTYPE QueryInterface (REFIID riid, LPVOID* ppv)
{
*ppv = NULL;
if (riid == IID_IUnknown)
{
*ppv = (IUnknown*)this;
}
else if (riid == IID_IMyInterface)
{
*ppv = (IMyInterface*)this;
}
if (*ppv)
{
((IUnknown*)(*ppv))->AddRef();
return S_OK;
}
return E_NOINTERFACE;
}
ULONG STDMETHODCALLTYPE AddRef ()
{
InterlockedIncrement((LONG*)&refcount);
return 0xcccccccc;
}
ULONG STDMETHODCALLTYPE Release ()
{
if (!InterlockedDecrement((LONG*)&refcount))
{
delete this;
return 0;
}
return 0xcccccccc;
}
// IMyInterface methods
HRESULT STDMETHODCALLTYPE COMCheckedLoad (BSTR pwszFilename, BYTE buffer[], int *bufsize)
{
HRESULT hr = CheckJavaWriteAccess(pwszFilename);
if (SUCCEEDED(hr))
{
hr = JavaCheckedLoad(pwszFilename, buffer, bufsize);
}
return hr;
}
HRESULT STDMETHODCALLTYPE JavaCheckedLoad (BSTR pwszFilename, BYTE buffer[], int *bufsize)
{
if (pwszFilename == NULL || buffer == NULL || bufsize == NULL)
return E_POINTER;
if (*bufsize < 0)
return E_INVALIDARG;
HRESULT hr = E_FAIL;
CHAR filename[MAX_PATH];
int filenamelen = WideCharToMultiByte(
CP_ACP,
0,
pwszFilename,
-1,
filename,
sizeof(filename)-1,
NULL,
NULL);
if (filenamelen != 0)
{
filename[filenamelen] = '\0';
HANDLE file = CreateFile(
filename,
GENERIC_READ,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_FLAG_SEQUENTIAL_SCAN,
NULL
);
if (file != INVALID_HANDLE_VALUE)
{
DWORD size = GetFileSize(file, NULL);
if (size != 0xffffffff)
{
DWORD toread = size;
if (toread > *bufsize)
toread = *bufsize;
DWORD read;
if (ReadFile(
file,
buffer,
toread,
&read,
NULL
)
&& read == size
)
{
*bufsize = read;
hr = S_OK;
}
}
CloseHandle(file);
}
}
if (hr == E_FAIL)
hr = HRESULT_FROM_WIN32(GetLastError());
return hr;
}
};
class CMyComObjectClassFactory : public IClassFactory
{
public:
CMyComObjectClassFactory ()
{
ObjectCreated();
}
~CMyComObjectClassFactory ()
{
ObjectDestroyed();
}
// IUnknown methods
HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, LPVOID* ppv)
{
*ppv = NULL;
if (riid == IID_IUnknown)
{
*ppv = (IUnknown*)this;
}
else if (riid == IID_IClassFactory)
{
*ppv = (IClassFactory*)this;
}
if (*ppv)
{
((IUnknown*)(*ppv))->AddRef();
return S_OK;
}
return E_NOINTERFACE;
}
ULONG STDMETHODCALLTYPE AddRef ()
{
return 0xcccccccc;
}
ULONG STDMETHODCALLTYPE Release ()
{
return 0xcccccccc;
}
// IClassFactory methods
HRESULT STDMETHODCALLTYPE CreateInstance (IUnknown *punkOuter, REFIID riid, VOID **ppv)
{
HRESULT hr;
*ppv = NULL;
if (punkOuter)
{
return CLASS_E_NOAGGREGATION;
}
CMyCOMObject *obj = new CMyCOMObject();
if (obj == NULL)
{
return E_OUTOFMEMORY;
}
hr = obj->QueryInterface(riid, ppv);
obj->Release();
return hr;
}
HRESULT STDMETHODCALLTYPE LockServer (BOOL fLock)
{
if (fLock)
ObjectCreated();
else
ObjectDestroyed();
return S_OK;
}
};
CMyComObjectClassFactory g_CMyCOMObjectFactory;
extern "C"
BOOL WINAPI DllMain (HINSTANCE hmod, DWORD dwReason, PVOID pvReserved)
{
ghInstance = hmod;
return TRUE;
}
STDAPI DllGetClassObject (REFCLSID rclsid, REFIID riid, LPVOID *ppv)
{
*ppv = NULL;
if (rclsid == CLSID_CMyCOMObject)
{
return g_CMyCOMObjectFactory.QueryInterface(riid, ppv);
}
else
{
return CLASS_E_CLASSNOTAVAILABLE;
}
}
STDAPI DllCanUnloadNow ()
{
return g_ObjectCount;
}
// Plagiarized from comsamp.
#define GUIDSTR_MAX (1+ 8 + 1 + 4 + 1 + 4 + 1 + 4 + 1 + 12 + 1 + 1)
static const CHAR szDigits[] = "0123456789ABCDEF";
static const BYTE GuidMap[] = { 3, 2, 1, 0, '-', 5, 4, '-', 7, 6, '-',
8, 9, '-', 10, 11, 12, 13, 14, 15 };
//--------------------------------------------------------------------------
//
// Function: GUID2StringA
//
// Synopsis: Convert GUID to string form
//
// Arguments: [rguid] - the guid to convert
// [lpszy] - buffer to hold the results
//
// Returns: nothing
//
// This code is massively plagiarized from the Ole sources.
//--------------------------------------------------------------------------
VOID
GUID2StringA(REFGUID rguid, LPSTR lpsz)
{
int i;
LPSTR p = lpsz;
const BYTE * pBytes = (const BYTE *) &rguid;
*p++ = '{';
for (i = 0; i < sizeof(GuidMap); i++)
{
if (GuidMap[i] == '-')
{
*p++ = '-';
}
else
{
*p++ = szDigits[ (pBytes[GuidMap[i]] & 0xF0) >> 4 ];
*p++ = szDigits[ (pBytes[GuidMap[i]] & 0x0F) ];
}
}
*p++ = '}';
*p = '\0';
}
//--------------------------------------------------------------------------
//
// NTCompatibleRegDeleteKey
//
//--------------------------------------------------------------------------
LONG
NTCompatibleRegDeleteKey(HKEY hKey, LPCTSTR szSubKey)
{
TCHAR achName[MAX_PATH+1];
HKEY hSubkey;
if (ERROR_SUCCESS != RegOpenKey(hKey, szSubKey, &hSubkey)) {
return REGDB_E_INVALIDVALUE;
}
if (ERROR_SUCCESS == RegEnumKey(hSubkey, 0, achName, sizeof(achName)/sizeof(TCHAR))) {
RegCloseKey(hSubkey);
// There's still one subkey: fail the call.
return REGDB_E_INVALIDVALUE;
}
RegCloseKey(hSubkey);
return RegDeleteKey(hKey, szSubKey);
}
STDAPI DllRegisterServer ()
{
HKEY hKey = NULL;
HKEY hKey2 = NULL;
HKEY hKey3 = NULL;
DWORD result;
HRESULT hr = SELFREG_E_CLASS;
CHAR achCLSID[GUIDSTR_MAX];
TCHAR achModulePathName[MAX_PATH];
// If we fail in the middle, the state of the registry entries
// is indeterminate (as per Ole specs.)
// Create HKEY_CLASSES_ROOT\progid\CLSID
result = RegCreateKey(HKEY_CLASSES_ROOT, achSampleProgID, &hKey);
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = RegCreateKey(hKey, TEXT("CLSID"), &hKey2);
if (result != ERROR_SUCCESS) {
goto lExit;
}
GUID2StringA(CLSID_CMyCOMObject, achCLSID);
result = RegSetValue(hKey2, NULL, REG_SZ, achCLSID, GUIDSTR_MAX-1);
if (result != ERROR_SUCCESS) {
goto lExit;
}
RegCloseKey(hKey);
RegCloseKey(hKey2);
hKey = NULL;
hKey2 = NULL;
// Create HKEY_CLASSES_ROOT\CLSID\...
result = RegCreateKey(HKEY_CLASSES_ROOT, TEXT("CLSID"), &hKey);
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = RegCreateKey(hKey, achCLSID, &hKey2);
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = RegCreateKey(hKey2, achInprocServer32, &hKey3);
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = GetModuleFileName(ghInstance, achModulePathName, sizeof(achModulePathName)/sizeof(TCHAR));
if (result == 0) { //No way to detect truncation from GetModuleFileName.
goto lExit;
}
result = RegSetValue(hKey3, NULL, REG_SZ, achModulePathName, lstrlen(achModulePathName));
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = RegSetValueEx(hKey3, achThreadingModel, 0, REG_SZ, (BYTE*)achBoth, sizeof(achBoth));
if (result != ERROR_SUCCESS) {
goto lExit;
}
RegCloseKey(hKey3);
hKey3 = NULL;
result = RegCreateKey(hKey2, achProgID, &hKey3);
if (result != ERROR_SUCCESS) {
goto lExit;
}
result = RegSetValue(hKey3, NULL, REG_SZ, achSampleProgID, lstrlen(achSampleProgID));
if (result != ERROR_SUCCESS) {
goto lExit;
}
RegCloseKey(hKey3);
hKey3 = NULL;
hr = S_OK;
lExit:
if (hKey) {
RegCloseKey(hKey);
}
if (hKey2) {
RegCloseKey(hKey2);
}
if (hKey3) {
RegCloseKey(hKey3);
}
return hr;
}
//----------------------------------------------------------------------
// DllUnregisterServer(): Called by OLE.
//----------------------------------------------------------------------
STDAPI DllUnregisterServer(VOID)
{
HKEY hKey = NULL;
HKEY hKey2 = NULL;
DWORD result;
HRESULT hr = SELFREG_E_CLASS;
CHAR achCLSID[GUIDSTR_MAX];
// If we fail in the middle, the state of the registry entries
// is indeterminate (as per Ole specs.)
GUID2StringA(CLSID_CMyCOMObject, achCLSID);
result = RegOpenKey(HKEY_CLASSES_ROOT, achSampleProgID, &hKey);
if (result == ERROR_SUCCESS) {
NTCompatibleRegDeleteKey(hKey, TEXT("CLSID"));
RegCloseKey(hKey);
hKey = NULL;
NTCompatibleRegDeleteKey(HKEY_CLASSES_ROOT, achSampleProgID);
}
// If this fails, it means somebody else added a subkey to this tree.
// We're not allowed to touch it so ignore the failure.
result = RegOpenKey(HKEY_CLASSES_ROOT, TEXT("CLSID"), &hKey);
if (result == ERROR_SUCCESS) {
result = RegOpenKey(hKey, achCLSID, &hKey2);
if (result == ERROR_SUCCESS) {
NTCompatibleRegDeleteKey(hKey2, achInprocServer32);
NTCompatibleRegDeleteKey(hKey2, achProgID);
RegCloseKey(hKey2);
hKey2 = NULL;
NTCompatibleRegDeleteKey(hKey, achCLSID);
}
// If this fails, it means somebody else added a subkey to this tree.
// We're not allowed to touch it so ignore the failure.
RegCloseKey(hKey);
hKey = NULL;
}
hr = S_OK;
return hr;
}