Merge pull request #3379 from nfedera/fix-winpr-wtsapi

winpr/wtsapi: fixed race conditions and tests

winpr/include/winpr/wtsapi.h

@@ -1389,6 +1389,7 @@ extern "C" {
 
 WINPR_API BOOL WTSRegisterWtsApiFunctionTable(PWtsApiFunctionTable table);
 WINPR_API const CHAR* WTSErrorToString(UINT error);
+WINPR_API const CHAR* WTSSessionStateToString(WTS_CONNECTSTATE_CLASS state);
 
 #ifdef __cplusplus
 }

winpr/libwinpr/wtsapi/CMakeLists.txt

@@ -15,8 +15,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-winpr_module_add(wtsapi.c
-	wtsapi.h)
+winpr_module_add(wtsapi.c)
 
 if(WIN32)
 	winpr_module_add(wtsapi_win32.c wtsapi_win32.h)

winpr/libwinpr/wtsapi/test/TestWtsApiEnumerateProcesses.c

@@ -2,27 +2,45 @@
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiEnumerateProcesses(int argc, char* argv[])
 {
 	DWORD count;
 	BOOL bSuccess;
 	HANDLE hServer;
-	PWTS_PROCESS_INFO pProcessInfo;
+	PWTS_PROCESS_INFOA pProcessInfo;
+
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#endif
 
 	hServer = WTS_CURRENT_SERVER_HANDLE;
 
 	count = 0;
 	pProcessInfo = NULL;
 
-	bSuccess = WTSEnumerateProcesses(hServer, 0, 1, &pProcessInfo, &count);
+	bSuccess = WTSEnumerateProcessesA(hServer, 0, 1, &pProcessInfo, &count);
 
 	if (!bSuccess)
 	{
-		printf("WTSEnumerateProcesses failed: %d\n", (int) GetLastError());
-		//return -1;
+		printf("WTSEnumerateProcesses failed: %u\n", GetLastError());
+		return -1;
 	}
 
+#if 0
+	{
+		DWORD i;
+		printf("WTSEnumerateProcesses enumerated %u processs:\n", count);
+		for (i = 0; i < count; i++)
+			printf("\t[%u]: %s (%lu)\n", i, pProcessInfo[i].pProcessName, pProcessInfo[i].ProcessId);
+	}
+#endif
+
 	WTSFreeMemory(pProcessInfo);
 
 	return 0;

winpr/libwinpr/wtsapi/test/TestWtsApiEnumerateSessions.c

@@ -2,6 +2,7 @@
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiEnumerateSessions(int argc, char* argv[])
 {
@@ -9,14 +10,22 @@ int TestWtsApiEnumerateSessions(int argc, char* argv[])
 	DWORD count;
 	BOOL bSuccess;
 	HANDLE hServer;
-	PWTS_SESSION_INFO pSessionInfo;
+	PWTS_SESSION_INFOA pSessionInfo;
+
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#endif
 
 	hServer = WTS_CURRENT_SERVER_HANDLE;
 
 	count = 0;
 	pSessionInfo = NULL;
 
-	bSuccess = WTSEnumerateSessions(hServer, 0, 1, &pSessionInfo, &count);
+	bSuccess = WTSEnumerateSessionsA(hServer, 0, 1, &pSessionInfo, &count);
 
 	if (!bSuccess)
 	{
@@ -28,9 +37,11 @@ int TestWtsApiEnumerateSessions(int argc, char* argv[])
 
 	for (index = 0; index < count; index++)
 	{
-		printf("[%d] SessionId: %d State: %d\n", (int) index,
-				(int) pSessionInfo[index].SessionId,
-				(int) pSessionInfo[index].State);
+		printf("[%u] SessionId: %u WinstationName: '%s' State: %s (%u)\n", index,
+			pSessionInfo[index].SessionId,
+			pSessionInfo[index].pWinStationName,
+			WTSSessionStateToString(pSessionInfo[index].State),
+			pSessionInfo[index].State);
 	}
 
 	WTSFreeMemory(pSessionInfo);

winpr/libwinpr/wtsapi/test/TestWtsApiQuerySessionInformation.c

@@ -2,24 +2,33 @@
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 {
-	DWORD index;
+	DWORD index, i;
 	DWORD count;
 	BOOL bSuccess;
 	HANDLE hServer;
 	LPSTR pBuffer;
 	DWORD sessionId;
 	DWORD bytesReturned;
-	PWTS_SESSION_INFO pSessionInfo;
+	PWTS_SESSION_INFOA pSessionInfo;
+
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#endif
 
 	hServer = WTS_CURRENT_SERVER_HANDLE;
 
 	count = 0;
 	pSessionInfo = NULL;
 
-	bSuccess = WTSEnumerateSessions(hServer, 0, 1, &pSessionInfo, &count);
+	bSuccess = WTSEnumerateSessionsA(hServer, 0, 1, &pSessionInfo, &count);
 
 	if (!bSuccess)
 	{
@@ -47,9 +56,12 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 
 		sessionId = pSessionInfo[index].SessionId;
 
-		printf("[%d] SessionId: %d State: %d\n", (int) index,
-				(int) pSessionInfo[index].SessionId,
-				(int) pSessionInfo[index].State);
+		printf("[%u] SessionId: %u State: %s (%u) WinstationName: '%s'\n",
+				index,
+				pSessionInfo[index].SessionId,
+				WTSSessionStateToString(pSessionInfo[index].State),
+				pSessionInfo[index].State,
+				pSessionInfo[index].pWinStationName);
 
 		/* WTSUserName */
 
@@ -62,7 +74,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		Username = (char*) pBuffer;
-		printf("\tWTSUserName: %s\n", Username);
+		printf("\tWTSUserName: '%s'\n", Username);
 
 		/* WTSDomainName */
 
@@ -75,7 +87,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		Domain = (char*) pBuffer;
-		printf("\tWTSDomainName: %s\n", Domain);
+		printf("\tWTSDomainName: '%s'\n", Domain);
 
 		/* WTSConnectState */
 
@@ -88,7 +100,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ConnectState = *((WTS_CONNECTSTATE_CLASS*) pBuffer);
-		printf("\tWTSConnectState: %d\n", (int) ConnectState);
+		printf("\tWTSConnectState: %u (%s)\n", ConnectState, WTSSessionStateToString(ConnectState));
 
 		/* WTSClientBuildNumber */
 
@@ -101,7 +113,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientBuildNumber = *((ULONG*) pBuffer);
-		printf("\tWTSClientBuildNumber: %d\n", (int) ClientBuildNumber);
+		printf("\tWTSClientBuildNumber: %u\n", ClientBuildNumber);
 
 		/* WTSClientName */
 
@@ -114,7 +126,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientName = (char*) pBuffer;
-		printf("\tWTSClientName: %s\n", ClientName);
+		printf("\tWTSClientName: '%s'\n", ClientName);
 
 		/* WTSClientProductId */
 
@@ -127,7 +139,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientProductId = *((USHORT*) pBuffer);
-		printf("\tWTSClientProductId: %d\n", (int) ClientProductId);
+		printf("\tWTSClientProductId: %u\n", ClientProductId);
 
 		/* WTSClientHardwareId */
 
@@ -140,7 +152,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientHardwareId = *((ULONG*) pBuffer);
-		printf("\tWTSClientHardwareId: %d\n", (int) ClientHardwareId);
+		printf("\tWTSClientHardwareId: %u\n", ClientHardwareId);
 
 		/* WTSClientAddress */
 
@@ -153,8 +165,12 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientAddress = (PWTS_CLIENT_ADDRESS) pBuffer;
-		printf("\tWTSClientAddress: AddressFamily: %d\n",
-				(int) ClientAddress->AddressFamily);
+		printf("\tWTSClientAddress: AddressFamily: %u Address: ",
+				ClientAddress->AddressFamily);
+		for (i = 0; i < sizeof(ClientAddress->Address); i++)
+			printf("%02X", ClientAddress->Address[i]);
+		printf("\n");
+
 
 		/* WTSClientDisplay */
 
@@ -167,9 +183,9 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientDisplay = (PWTS_CLIENT_DISPLAY) pBuffer;
-		printf("\tWTSClientDisplay: HorizontalResolution: %d VerticalResolution: %d ColorDepth: %d\n",
-				(int) ClientDisplay->HorizontalResolution, (int) ClientDisplay->VerticalResolution,
-				(int) ClientDisplay->ColorDepth);
+		printf("\tWTSClientDisplay: HorizontalResolution: %u VerticalResolution: %u ColorDepth: %u\n",
+				ClientDisplay->HorizontalResolution, ClientDisplay->VerticalResolution,
+				ClientDisplay->ColorDepth);
 
 		/* WTSClientProtocolType */
 
@@ -182,7 +198,7 @@ int TestWtsApiQuerySessionInformation(int argc, char* argv[])
 		}
 
 		ClientProtocolType = *((USHORT*) pBuffer);
-		printf("\tWTSClientProtocolType: %d\n", (int) ClientProtocolType);
+		printf("\tWTSClientProtocolType: %u\n", ClientProtocolType);
 	}
 
 	WTSFreeMemory(pSessionInfo);

winpr/libwinpr/wtsapi/test/TestWtsApiSessionNotification.c

@@ -2,30 +2,54 @@
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiSessionNotification(int argc, char* argv[])
 {
-	HWND hWnd;
+	HWND hWnd = NULL;
 	BOOL bSuccess;
 	DWORD dwFlags;
 
-	hWnd = NULL;
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#else
+	/* We create a message-only window and use the predefined class name "STATIC" for simplicity */
+	hWnd = CreateWindowA("STATIC", "TestWtsApiSessionNotification", 0, 0, 0, 0, 0, HWND_MESSAGE, NULL, NULL, NULL);
+	if (!hWnd)
+	{
+		printf("%s: error creating message-only window: %u\n", __FUNCTION__, GetLastError());
+		return -1;
+	}
+#endif
+
 	dwFlags = NOTIFY_FOR_ALL_SESSIONS;
 
 	bSuccess = WTSRegisterSessionNotification(hWnd, dwFlags);
 
 	if (!bSuccess)
 	{
-		printf("WTSRegisterSessionNotification failed: %d\n", (int) GetLastError());
-		//return -1;
+		printf("%s: WTSRegisterSessionNotification failed: %u\n", __FUNCTION__, GetLastError());
+		return -1;
 	}
 
 	bSuccess = WTSUnRegisterSessionNotification(hWnd);
 
+#ifdef _WIN32
+	if (hWnd)
+	{
+		DestroyWindow(hWnd);
+		hWnd = NULL;
+	}
+#endif
+
 	if (!bSuccess)
 	{
-		printf("WTSUnRegisterSessionNotification failed: %d\n", (int) GetLastError());
-		//return -1;
+		printf("%s: WTSUnRegisterSessionNotification failed: %u\n", __FUNCTION__, GetLastError());
+		return -1;
 	}
 
 	return 0;

winpr/libwinpr/wtsapi/test/TestWtsApiShutdownSystem.c

@@ -1,7 +1,7 @@
-
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiShutdownSystem(int argc, char* argv[])
 {
@@ -9,6 +9,14 @@ int TestWtsApiShutdownSystem(int argc, char* argv[])
 	HANDLE hServer;
 	DWORD ShutdownFlag;
 
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#endif
+
 	hServer = WTS_CURRENT_SERVER_HANDLE;
 	ShutdownFlag = WTS_WSD_SHUTDOWN;
 
@@ -17,7 +25,7 @@ int TestWtsApiShutdownSystem(int argc, char* argv[])
 	if (!bSuccess)
 	{
 		printf("WTSShutdownSystem failed: %d\n", (int) GetLastError());
-		//return -1;
+		return -1;
 	}
 
 	return 0;

winpr/libwinpr/wtsapi/test/TestWtsApiWaitSystemEvent.c

@@ -2,6 +2,7 @@
 #include <winpr/crt.h>
 #include <winpr/error.h>
 #include <winpr/wtsapi.h>
+#include <winpr/environment.h>
 
 int TestWtsApiWaitSystemEvent(int argc, char* argv[])
 {
@@ -10,6 +11,14 @@ int TestWtsApiWaitSystemEvent(int argc, char* argv[])
 	DWORD eventMask;
 	DWORD eventFlags;
 
+#ifndef _WIN32
+	if (!GetEnvironmentVariableA("WTSAPI_LIBRARY", NULL, 0))
+	{
+		printf("%s: No RDS environment detected, skipping test\n", __FUNCTION__);
+		return 0;
+	}
+#endif
+
 	hServer = WTS_CURRENT_SERVER_HANDLE;
 
 	eventMask = WTS_EVENT_ALL;
@@ -20,7 +29,7 @@ int TestWtsApiWaitSystemEvent(int argc, char* argv[])
 	if (!bSuccess)
 	{
 		printf("WTSWaitSystemEvent failed: %d\n", (int) GetLastError());
-		//return -1;
+		return -1;
 	}
 
 	return 0;

winpr/libwinpr/wtsapi/wtsapi.c

@@ -32,8 +32,6 @@
 
 #include <winpr/wtsapi.h>
 
-#include "wtsapi.h"
-
 #ifdef _WIN32
 #include "wtsapi_win32.h"
 #endif
@@ -46,9 +44,6 @@
  * http://msdn.microsoft.com/en-us/library/windows/desktop/aa383464/
  */
 
-void InitializeWtsApiStubs(void);
-
-static BOOL g_Initialized = FALSE;
 static HMODULE g_WtsApiModule = NULL;
 
 static PWtsApiFunctionTable g_WtsApi = NULL;
@@ -128,12 +123,12 @@ static WtsApiFunctionTable WtsApi32_WtsApiFunctionTable =
 #define WTSAPI32_LOAD_PROC(_name, _type) \
 	WtsApi32_WtsApiFunctionTable.p ## _name = (## _type) GetProcAddress(g_WtsApi32Module, "WTS" #_name);
 
-int WtsApi32_InitializeWtsApi(void)
+BOOL WtsApi32_InitializeWtsApi(void)
 {
 	g_WtsApi32Module = LoadLibraryA("wtsapi32.dll");
 
 	if (!g_WtsApi32Module)
-		return -1;
+		return FALSE;
 
 #ifdef _WIN32
 	WTSAPI32_LOAD_PROC(StopRemoteControlSession, WTS_STOP_REMOTE_CONTROL_SESSION_FN);
@@ -205,11 +200,33 @@ int WtsApi32_InitializeWtsApi(void)
 
 	g_WtsApi = &WtsApi32_WtsApiFunctionTable;
 
-	return 1;
+	return TRUE;
 }
 
 /* WtsApi Functions */
 
+static BOOL CALLBACK InitializeWtsApiStubs(PINIT_ONCE once, PVOID param, PVOID *context);
+static INIT_ONCE wtsapiInitOnce = INIT_ONCE_STATIC_INIT;
+
+#define WTSAPI_STUB_CALL_VOID(_name, ...) \
+	InitOnceExecuteOnce(&wtsapiInitOnce, InitializeWtsApiStubs, NULL, NULL); \
+	if (!g_WtsApi || !g_WtsApi->p ## _name) \
+		return; \
+	g_WtsApi->p ## _name ( __VA_ARGS__ )
+
+#define WTSAPI_STUB_CALL_BOOL(_name, ...) \
+	InitOnceExecuteOnce(&wtsapiInitOnce, InitializeWtsApiStubs, NULL, NULL); \
+	if (!g_WtsApi || !g_WtsApi->p ## _name) \
+		return FALSE; \
+	return g_WtsApi->p ## _name ( __VA_ARGS__ )
+
+#define WTSAPI_STUB_CALL_HANDLE(_name, ...) \
+	InitOnceExecuteOnce(&wtsapiInitOnce, InitializeWtsApiStubs, NULL, NULL); \
+	if (!g_WtsApi || !g_WtsApi->p ## _name) \
+		return NULL; \
+	return g_WtsApi->p ## _name ( __VA_ARGS__ )
+
+
 BOOL WINAPI WTSStartRemoteControlSessionW(LPWSTR pTargetServerName, ULONG TargetLogonId, BYTE HotkeyVk, USHORT HotkeyModifiers)
 {
 	WTSAPI_STUB_CALL_BOOL(StartRemoteControlSessionW, pTargetServerName, TargetLogonId, HotkeyVk, HotkeyModifiers);
@@ -566,8 +583,7 @@ BOOL CDECL WTSLogoffUser(HANDLE hServer)
 
 DWORD WINAPI WTSGetActiveConsoleSessionId(void)
 {
-	if (!g_Initialized)
-		InitializeWtsApiStubs();
+	InitOnceExecuteOnce(&wtsapiInitOnce, InitializeWtsApiStubs, NULL, NULL);
 
 	if (!g_WtsApi || !g_WtsApi->pGetActiveConsoleSessionId)
 		return 0xFFFFFFFF;
@@ -649,10 +665,37 @@ const CHAR* WTSErrorToString(UINT error)
 	}
 }
 
+const CHAR* WTSSessionStateToString(WTS_CONNECTSTATE_CLASS state)
+{
+	switch (state)
+	{
+	case WTSActive:
+		return "WTSActive";
+	case WTSConnected:
+		return "WTSConnected";
+	case WTSConnectQuery:
+		return "WTSConnectQuery";
+	case WTSShadow:
+		return "WTSShadow";
+	case WTSDisconnected:
+		return "WTSDisconnected";
+	case WTSIdle:
+		return "WTSIdle";
+	case WTSListen:
+		return "WTSListen";
+	case WTSReset:
+		return "WTSReset";
+	case WTSDown:
+		return "WTSDown";
+	case WTSInit:
+		return "WTSInit";
+	}
+	return "INVALID_STATE";
+}
+
 BOOL WTSRegisterWtsApiFunctionTable(PWtsApiFunctionTable table)
 {
 	g_WtsApi = table;
-	g_Initialized = TRUE;
 	return TRUE;
 }
 
@@ -675,7 +718,7 @@ static BOOL LoadAndInitialize(char* library)
 	return TRUE;
 }
 
-void InitializeWtsApiStubs_Env()
+static void InitializeWtsApiStubs_Env()
 {
 	DWORD nSize;
 	char *env = NULL;
@@ -699,7 +742,7 @@ void InitializeWtsApiStubs_Env()
 
 #define FREERDS_LIBRARY_NAME "libfreerds-fdsapi.so"
 
-void InitializeWtsApiStubs_FreeRDS()
+static void InitializeWtsApiStubs_FreeRDS()
 {
 	wIniFile* ini;
 	const char* prefix;
@@ -741,12 +784,9 @@ void InitializeWtsApiStubs_FreeRDS()
 	IniFile_Free(ini);
 }
 
-void InitializeWtsApiStubs(void)
-{
-	if (g_Initialized)
-		return;
 
-	g_Initialized = TRUE;
+static BOOL CALLBACK InitializeWtsApiStubs(PINIT_ONCE once, PVOID param, PVOID *context)
+{
 	InitializeWtsApiStubs_Env();
 
 #ifdef _WIN32
@@ -756,5 +796,5 @@ void InitializeWtsApiStubs(void)
 	if (!g_WtsApi)
 		InitializeWtsApiStubs_FreeRDS();
 
-	return;
+	return TRUE;
 }

winpr/libwinpr/wtsapi/wtsapi.h

@@ -1,44 +0,0 @@
-/**
- * WinPR: Windows Portable Runtime
- * Windows Terminal Services API
- *
- * Copyright 2013 Marc-Andre Moreau <marcandre.moreau@gmail.com>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef WINPR_WTSAPI_PRIVATE_H
-#define WINPR_WTSAPI_PRIVATE_H
-
-#define WTSAPI_STUB_CALL_VOID(_name, ...) \
-	if (!g_Initialized) \
-		InitializeWtsApiStubs(); \
-	if (!g_WtsApi || !g_WtsApi->p ## _name) \
-		return; \
-	g_WtsApi->p ## _name ( __VA_ARGS__ )
-
-#define WTSAPI_STUB_CALL_BOOL(_name, ...) \
-	if (!g_Initialized) \
-		InitializeWtsApiStubs(); \
-	if (!g_WtsApi || !g_WtsApi->p ## _name) \
-		return FALSE; \
-	return g_WtsApi->p ## _name ( __VA_ARGS__ )
-
-#define WTSAPI_STUB_CALL_HANDLE(_name, ...) \
-	if (!g_Initialized) \
-		InitializeWtsApiStubs(); \
-	if (!g_WtsApi || !g_WtsApi->p ## _name) \
-		return NULL; \
-	return g_WtsApi->p ## _name ( __VA_ARGS__ )
-
-#endif /* WINPR_WTSAPI_PRIVATE_H */

winpr/libwinpr/wtsapi/wtsapi_win32.c

@@ -30,7 +30,6 @@
 
 #include "wtsapi_win32.h"
 
-#include "wtsapi.h"
 #include "../log.h"
 
 #define WTSAPI_CHANNEL_MAGIC	0x44484356
@@ -72,6 +71,37 @@ static fnWinStationVirtualOpenEx pfnWinStationVirtualOpenEx = NULL;
 
 BOOL WINAPI Win32_WTSVirtualChannelClose(HANDLE hChannel);
 
+
+/**
+  * NOTE !!
+  * An application using the WinPR wtsapi frees memory via WTSFreeMemory, which
+  * might be mapped to Win32_WTSFreeMemory. Latter does not know if the passed
+  * pointer was allocated by a function in wtsapi32.dll or in some internal
+  * code below. The WTSFreeMemory implementation in all Windows wtsapi32.dll
+  * versions up to Windows 10 uses LocalFree since all its allocating functions
+  * use LocalAlloc() internally.
+  * For that reason we also have to use LocalAlloc() for any memory returned by
+  * our WinPR wtsapi functions.
+  *
+  * To be safe we only use the _wts_malloc, _wts_calloc, _wts_free wrappers
+  * for memory managment the code below.
+  */
+
+static void *_wts_malloc(size_t size)
+{
+	return (PVOID)LocalAlloc(LMEM_FIXED, size);
+}
+
+static void *_wts_calloc(size_t nmemb, size_t size)
+{
+	return (PVOID)LocalAlloc(LMEM_FIXED | LMEM_ZEROINIT, nmemb * size);
+}
+
+static void _wts_free(void* ptr)
+{
+	LocalFree((HLOCAL)ptr);
+}
+
 BOOL Win32_WTSVirtualChannelReadAsync(WTSAPI_CHANNEL* pChannel)
 {
 	BOOL status = TRUE;
@@ -130,19 +160,28 @@ HANDLE WINAPI Win32_WTSVirtualChannelOpen_Internal(HANDLE hServer, DWORD Session
 	HANDLE hFile;
 	HANDLE hChannel;
 	WTSAPI_CHANNEL* pChannel;
+	size_t virtualNameLen;
 
-	if (!pVirtualName)
+	virtualNameLen = pVirtualName ? strlen(pVirtualName) : 0;
+
+	if (!virtualNameLen)
 	{
 		SetLastError(ERROR_INVALID_PARAMETER);
 		return NULL;
 	}
 
+	if (!pfnWinStationVirtualOpenEx)
+	{
+		SetLastError(ERROR_INVALID_FUNCTION);
+		return NULL;
+	}
+
 	hFile = pfnWinStationVirtualOpenEx(hServer, SessionId, pVirtualName, flags);
 
 	if (!hFile)
 		return NULL;
 
-	pChannel = (WTSAPI_CHANNEL*) calloc(1, sizeof(WTSAPI_CHANNEL));
+	pChannel = (WTSAPI_CHANNEL*) _wts_calloc(1, sizeof(WTSAPI_CHANNEL));
 
 	if (!pChannel)
 	{
@@ -156,14 +195,15 @@ HANDLE WINAPI Win32_WTSVirtualChannelOpen_Internal(HANDLE hServer, DWORD Session
 	pChannel->hServer = hServer;
 	pChannel->SessionId = SessionId;
 	pChannel->hFile = hFile;
-	pChannel->VirtualName = _strdup(pVirtualName);
+	pChannel->VirtualName = _wts_calloc(1, virtualNameLen + 1);
 	if (!pChannel->VirtualName)
 	{
 		CloseHandle(hFile);
 		SetLastError(ERROR_NOT_ENOUGH_MEMORY);
-		free(pChannel);
+		_wts_free(pChannel);
 		return NULL;
 	}
+	memcpy(pChannel->VirtualName, pVirtualName, virtualNameLen);
 
 	pChannel->flags = flags;
 	pChannel->dynamic = (flags & WTS_CHANNEL_OPTION_DYNAMIC) ? TRUE : FALSE;
@@ -171,7 +211,7 @@ HANDLE WINAPI Win32_WTSVirtualChannelOpen_Internal(HANDLE hServer, DWORD Session
 	pChannel->showProtocol = pChannel->dynamic;
 
 	pChannel->readSize = CHANNEL_PDU_LENGTH;
-	pChannel->readBuffer = (BYTE*) malloc(pChannel->readSize);
+	pChannel->readBuffer = (BYTE*) _wts_malloc(pChannel->readSize);
 
 	pChannel->header = (CHANNEL_PDU_HEADER*) pChannel->readBuffer;
 	pChannel->chunk = &(pChannel->readBuffer[sizeof(CHANNEL_PDU_HEADER)]);
@@ -230,18 +270,18 @@ BOOL WINAPI Win32_WTSVirtualChannelClose(HANDLE hChannel)
 
 	if (pChannel->VirtualName)
 	{
-		free(pChannel->VirtualName);
+		_wts_free(pChannel->VirtualName);
 		pChannel->VirtualName = NULL;
 	}
 
 	if (pChannel->readBuffer)
 	{
-		free(pChannel->readBuffer);
+		_wts_free(pChannel->readBuffer);
 		pChannel->readBuffer = NULL;
 	}
 
 	pChannel->magic = 0;
-	free(pChannel);
+	_wts_free(pChannel);
 
 	return status;
 }
@@ -660,7 +700,7 @@ BOOL WINAPI Win32_WTSVirtualChannelQuery(HANDLE hChannelHandle, WTS_VIRTUAL_CLAS
 	else if (WtsVirtualClass == WTSVirtualFileHandle)
 	{
 		*pBytesReturned = sizeof(HANDLE);
-		*ppBuffer = calloc(1, *pBytesReturned);
+		*ppBuffer = _wts_calloc(1, *pBytesReturned);
 
 		if (*ppBuffer == NULL)
 		{
@@ -673,7 +713,7 @@ BOOL WINAPI Win32_WTSVirtualChannelQuery(HANDLE hChannelHandle, WTS_VIRTUAL_CLAS
 	else if (WtsVirtualClass == WTSVirtualEventHandle)
 	{
 		*pBytesReturned = sizeof(HANDLE);
-		*ppBuffer = calloc(1, *pBytesReturned);
+		*ppBuffer = _wts_calloc(1, *pBytesReturned);
 
 		if (*ppBuffer == NULL)
 		{
@@ -697,12 +737,12 @@ BOOL WINAPI Win32_WTSVirtualChannelQuery(HANDLE hChannelHandle, WTS_VIRTUAL_CLAS
 
 VOID WINAPI Win32_WTSFreeMemory(PVOID pMemory)
 {
-	free(pMemory);
+	_wts_free(pMemory);
 }
 
 BOOL WINAPI Win32_WTSFreeMemoryExW(WTS_TYPE_CLASS WTSTypeClass, PVOID pMemory, ULONG NumberOfEntries)
 {
-	return TRUE;
+	return FALSE;
 }
 
 BOOL WINAPI Win32_WTSFreeMemoryExA(WTS_TYPE_CLASS WTSTypeClass, PVOID pMemory, ULONG NumberOfEntries)
@@ -710,18 +750,18 @@ BOOL WINAPI Win32_WTSFreeMemoryExA(WTS_TYPE_CLASS WTSTypeClass, PVOID pMemory, U
 	return WTSFreeMemoryExW(WTSTypeClass, pMemory, NumberOfEntries);
 }
 
-int Win32_InitializeWinSta(PWtsApiFunctionTable pWtsApi)
+BOOL Win32_InitializeWinSta(PWtsApiFunctionTable pWtsApi)
 {
 	g_WinStaModule = LoadLibraryA("winsta.dll");
 
 	if (!g_WinStaModule)
-		return -1;
+		return FALSE;
 
 	pfnWinStationVirtualOpen = (fnWinStationVirtualOpen) GetProcAddress(g_WinStaModule, "WinStationVirtualOpen");
 	pfnWinStationVirtualOpenEx = (fnWinStationVirtualOpenEx) GetProcAddress(g_WinStaModule, "WinStationVirtualOpenEx");
 
-	if (!pfnWinStationVirtualOpenEx)
-		return -1;
+	if (!pfnWinStationVirtualOpen | !pfnWinStationVirtualOpenEx)
+		return FALSE;
 
 	pWtsApi->pVirtualChannelOpen = Win32_WTSVirtualChannelOpen;
 	pWtsApi->pVirtualChannelOpenEx = Win32_WTSVirtualChannelOpenEx;
@@ -735,5 +775,5 @@ int Win32_InitializeWinSta(PWtsApiFunctionTable pWtsApi)
 	//pWtsApi->pFreeMemoryExW = Win32_WTSFreeMemoryExW;
 	//pWtsApi->pFreeMemoryExA = Win32_WTSFreeMemoryExA;
 
-	return 1;
+	return TRUE;
 }

winpr/libwinpr/wtsapi/wtsapi_win32.h

@@ -22,6 +22,6 @@
 
 #include <winpr/wtsapi.h>
 
-int Win32_InitializeWinSta(PWtsApiFunctionTable pWtsApi);
+BOOL Win32_InitializeWinSta(PWtsApiFunctionTable pWtsApi);
 
 #endif /* WINPR_WTSAPI_WIN32_PRIVATE_H */