Detect WinFsp when not installed in Program Files (x86)

WorkingRobot · Jun 5, 2020 · 01b6a62 · 01b6a62
1 parent 04910e6
commit 01b6a62
Showing 1 changed file with 33 additions and 10 deletions.
diff --git a/checks/winfspcheck.cpp b/checks/winfspcheck.cpp
@@ -1,33 +1,56 @@
 #include "winfspcheck.h"
 
+#define WINFSP_INSTALL_REGKEY   L"Software\\WOW6432Node\\WinFsp"
+#define WINFSP_INSTALL_REGVALUE L"InstallDir"
+
 #include <filesystem>
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <ShlObj_core.h>
 
 namespace fs = std::filesystem;
 
+fs::path GetRegInstallDir() {
+    HKEY key;
+    auto Result = RegOpenKeyEx(HKEY_LOCAL_MACHINE, WINFSP_INSTALL_REGKEY, NULL, KEY_READ, &key);
+
+    if (Result != ERROR_SUCCESS) { // should be ERROR_NO_MATCH or ERROR_FILE_NOT_FOUND
+        return nullptr; // In reality, it should always exist, so this shouldn't run
+    }
+    else {
+        WCHAR data[MAX_PATH];
+        DWORD type = REG_SZ;
+        DWORD size = sizeof(data);
+        Result = RegQueryValueEx(key, WINFSP_INSTALL_REGVALUE, NULL, &type, (LPBYTE)&data, &size);
+        RegCloseKey(key);
+        return Result == ERROR_SUCCESS ? data : nullptr;
+    }
+}
+
 WinFspCheckResult LoadWinFsp() {
     static bool alreadyLoaded = false;
     if (alreadyLoaded) {
         return WinFspCheckResult::LOADED;
     }
 
-    fs::path DataFolder;
-    {
-        PWSTR appDataFolder;
-        if (SHGetKnownFolderPath(FOLDERID_ProgramFilesX86, 0, NULL, &appDataFolder) != S_OK) {
-            return WinFspCheckResult::NO_PATH;
+    fs::path InstallDir = GetRegInstallDir();
+    if (InstallDir.empty()) {
+        {
+            PWSTR appDataFolder;
+            if (SHGetKnownFolderPath(FOLDERID_ProgramFilesX86, 0, NULL, &appDataFolder) != S_OK) {
+                return WinFspCheckResult::NO_PATH;
+            }
+            InstallDir = fs::path(appDataFolder) / "WinFsp";
+            CoTaskMemFree(appDataFolder);
         }
-        DataFolder = appDataFolder;
-        CoTaskMemFree(appDataFolder);
     }
-    DataFolder = DataFolder / "WinFsp" / "bin" / "winfsp-x64.dll";
 
-    if (fs::status(DataFolder).type() != fs::file_type::regular) {
+    InstallDir = InstallDir / "bin" / "winfsp-x64.dll";
+
+    if (fs::status(InstallDir).type() != fs::file_type::regular) {
         return WinFspCheckResult::NO_DLL;
     }
-    if (LoadLibraryA(DataFolder.string().c_str()) == NULL) {
+    if (LoadLibraryA(InstallDir.string().c_str()) == NULL) {
         return WinFspCheckResult::CANNOT_LOAD;
     }
     alreadyLoaded = true;