[PowerToys Run] run non-elevated when runner is elevated (#3451)

* run Launcher non-elevated

* Implemented acquiring PID of Launcher

Co-authored-by: ivan100sic <ivan100sic@gmail.com>

src/action_runner/action_runner.cpp

@@ -186,7 +186,28 @@ int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
     }
     std::wstring_view action{ args[1] };
 
-    if (action == L"-install_dotnet")
+
+    if (action == L"-start_PowerLauncher")
+    {
+        if (is_process_elevated(false) == true)
+        {
+            drop_elevated_privileges();
+        }
+
+        HANDLE hMapFile = OpenFileMappingW(FILE_MAP_WRITE, FALSE, POWER_LAUNCHER_PID_SHARED_FILE);
+        PDWORD pidBuffer = reinterpret_cast<PDWORD>(MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, sizeof(DWORD)));
+        if (pidBuffer)
+        {
+            *pidBuffer = 0;
+            run_non_elevated(L"modules\\launcher\\PowerLauncher.exe", L"", pidBuffer);
+            FlushViewOfFile(pidBuffer, sizeof(DWORD));
+            UnmapViewOfFile(pidBuffer);
+        }
+
+        FlushFileBuffers(hMapFile);
+        CloseHandle(hMapFile);
+    }
+    else if (action == L"-install_dotnet")
     {
         if (dotnet_is_installed())
         {

src/common/common.cpp

@@ -461,7 +461,7 @@ bool run_elevated(const std::wstring& file, const std::wstring& params)
     }
 }
 
-bool run_non_elevated(const std::wstring& file, const std::wstring& params)
+bool run_non_elevated(const std::wstring& file, const std::wstring& params, DWORD* returnPid)
 {
     auto executable_args = L"\"" + file + L"\"";
     if (!params.empty())
@@ -521,8 +521,14 @@ bool run_non_elevated(const std::wstring& file, const std::wstring& params)
                                     nullptr,
                                     &siex.StartupInfo,
                                     &process_info);
+
     if (process_info.hProcess)
     {
+        if (returnPid)
+        {
+            *returnPid = GetProcessId(process_info.hProcess);
+        }
+
         CloseHandle(process_info.hProcess);
     }
     if (process_info.hThread)

src/common/common.h

@@ -69,8 +69,8 @@ bool drop_elevated_privileges();
 // Run command as elevated user, returns true if succeeded
 bool run_elevated(const std::wstring& file, const std::wstring& params);
 
-// Run command as non-elevated user, returns true if succeeded
-bool run_non_elevated(const std::wstring& file, const std::wstring& params);
+// Run command as non-elevated user, returns true if succeeded, puts the process id into returnPid if returnPid != NULL
+bool run_non_elevated(const std::wstring& file, const std::wstring& params, DWORD* returnPid);
 
 // Run command with the same elevation, returns true if succedded
 bool run_same_elevation(const std::wstring& file, const std::wstring& params);
@@ -136,3 +136,5 @@ struct overloaded : Ts...
 };
 template<class... Ts>
 overloaded(Ts...)->overloaded<Ts...>;
+
+#define POWER_LAUNCHER_PID_SHARED_FILE L"Global\\3cbfbad4-199b-4e2c-9825-942d5d3d3c74"

src/modules/launcher/Microsoft.Launcher/dllmain.cpp

@@ -3,6 +3,7 @@
 #include <interface/lowlevel_keyboard_event_data.h>
 #include <interface/win_hook_event_data.h>
 #include <common/settings_objects.h>
+#include <common/common.h>
 #include "trace.h"
 #include "resource.h"
 
@@ -131,13 +132,47 @@ public:
    // Enable the powertoy
   virtual void enable()
   {
-      SHELLEXECUTEINFO sei{ sizeof(sei) };
-      sei.fMask = { SEE_MASK_NOCLOSEPROCESS | SEE_MASK_FLAG_NO_UI };
-      sei.lpFile = L"modules\\launcher\\PowerLauncher.exe";
-      sei.nShow = SW_SHOWNORMAL;
-      ShellExecuteEx(&sei);
+      if (is_process_elevated(false) == false)
+      {
+          SHELLEXECUTEINFOW sei{ sizeof(sei) };
+          sei.fMask = { SEE_MASK_NOCLOSEPROCESS | SEE_MASK_FLAG_NO_UI };
+          sei.lpFile = L"modules\\launcher\\PowerLauncher.exe";
+          sei.nShow = SW_SHOWNORMAL;
+          ShellExecuteExW(&sei);
 
-      m_hProcess = sei.hProcess;
+          m_hProcess = sei.hProcess;
+      }
+      else
+      {
+          std::wstring action_runner_path = get_module_folderpath();
+          action_runner_path += L"\\action_runner.exe";
+          SHELLEXECUTEINFOW sei{ sizeof(sei) };
+          sei.fMask = { SEE_MASK_NOCLOSEPROCESS | SEE_MASK_FLAG_NO_UI | SEE_MASK_NOASYNC };
+          sei.lpFile = action_runner_path.c_str();
+          sei.nShow = SW_SHOWNORMAL;
+          sei.lpParameters = L"-start_PowerLauncher";
+ 
+          // Set up the shared file from which to retrieve the PID of PowerLauncher
+          HANDLE hMapFile = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, sizeof(DWORD), POWER_LAUNCHER_PID_SHARED_FILE);
+          PDWORD pidBuffer = reinterpret_cast<PDWORD>(MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, sizeof(DWORD)));
+          *pidBuffer = 0;
+          m_hProcess = NULL;
+          ShellExecuteExW(&sei);
+          
+          const int maxRetries = 20;
+          for (int retry = 0; retry < maxRetries; ++retry)
+          {
+              Sleep(50);
+              DWORD pid = *pidBuffer;
+              if (pid)
+              {
+                  m_hProcess = OpenProcess(PROCESS_TERMINATE, FALSE, pid);
+                  break;
+              }
+          }
+
+          CloseHandle(hMapFile);
+      }
 
       m_enabled = true;
   }

src/runner/restart_elevated.cpp

@@ -36,7 +36,7 @@ bool restart_if_scheduled()
     case RestartAsElevated:
         return run_elevated(exe_path.get(), {});
     case RestartAsNonElevated:
-        return run_non_elevated(exe_path.get(), L"--dont-elevate");
+        return run_non_elevated(exe_path.get(), L"--dont-elevate", NULL);
     default:
         return false;
     }