Add a helper process to Chrome Frame to allow for non-administrative installs...

chrome_frame/chrome_frame_helper_main.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// chrome_frame_helper_main.cc : The .exe that bootstraps the
+// chrome_frame_helper.dll.
+//
+// This is a small exe that loads the hook dll to set the event hooks and then
+// waits in a message loop. It is intended to be shut down by looking for a
+// window with the class and title
+// kChromeFrameHelperWindowClassName and kChromeFrameHelperWindowName and then
+// sending that window a WM_CLOSE message.
+//
+
+#include <crtdbg.h>
+#include <windows.h>
+
+// Window class and window names.
+const wchar_t kChromeFrameHelperWindowClassName[] =
+    L"ChromeFrameHelperWindowClass";
+const wchar_t kChromeFrameHelperWindowName[] =
+    L"ChromeFrameHelperWindowName";
+
+// Small helper class that assists in loading the DLL that contains code
+// to register our event hook callback. Automatically removes the hook and
+// unloads the DLL on destruction.
+class HookDllLoader {
+ public:
+  HookDllLoader() : dll_(NULL), start_proc_(NULL), stop_proc_(NULL) {}
+  ~HookDllLoader() {
+    if (dll_) {
+      Unload();
+    }
+  }
+
+  bool Load() {
+    dll_ = LoadLibrary(L"chrome_frame_helper.dll");
+    if (dll_) {
+      start_proc_ = GetProcAddress(dll_, "StartUserModeBrowserInjection");
+      stop_proc_ = GetProcAddress(dll_, "StopUserModeBrowserInjection");
+    }
+
+    bool result = true;
+    if (!start_proc_ || !stop_proc_) {
+      _ASSERTE(L"failed to load hook dll.");
+      result = false;
+    } else {
+      if (FAILED(start_proc_())) {
+        _ASSERTE(L"failed to initialize hook dll.");
+        result = false;
+      }
+    }
+    return result;
+  }
+
+  void Unload() {
+    if (stop_proc_) {
+      stop_proc_();
+    }
+    if (dll_) {
+      FreeLibrary(dll_);
+    }
+  }
+
+ private:
+  HMODULE dll_;
+  PROC start_proc_;
+  PROC stop_proc_;
+};
+
+
+LRESULT CALLBACK ChromeFrameHelperWndProc(HWND hwnd,
+                                          UINT message,
+                                          WPARAM wparam,
+                                          LPARAM lparam) {
+  switch (message) {
+    case WM_DESTROY:
+      PostQuitMessage(0);
+      break;
+    default:
+      return ::DefWindowProc(hwnd, message, wparam, lparam);
+  }
+  return 0;
+}
+
+HWND RegisterAndCreateWindow(HINSTANCE hinstance) {
+  WNDCLASSEX wcex = {0};
+  wcex.cbSize         = sizeof(WNDCLASSEX);
+  wcex.lpfnWndProc    = ChromeFrameHelperWndProc;
+  wcex.hInstance      = GetModuleHandle(NULL);
+  wcex.hbrBackground  = reinterpret_cast<HBRUSH>(COLOR_WINDOW+1);
+  wcex.lpszClassName  = kChromeFrameHelperWindowClassName;
+  RegisterClassEx(&wcex);
+
+  HWND hwnd = CreateWindow(kChromeFrameHelperWindowClassName,
+      kChromeFrameHelperWindowName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0,
+      CW_USEDEFAULT, 0, NULL, NULL, hinstance, NULL);
+
+  return hwnd;
+}
+
+int APIENTRY wWinMain(HINSTANCE hinstance, HINSTANCE, wchar_t*, int show_cmd) {
+  // TODO(robertshield): Before this actually gets used, add breakpad
+  // integration.
+
+  // Create a window with a known class and title just to listen for WM_CLOSE
+  // messages that will shut us down.
+  HWND hwnd = RegisterAndCreateWindow(hinstance);
+  _ASSERTE(hwnd);
+
+  // Load the hook dll, and set the event hooks.
+  HookDllLoader loader;
+  bool loaded = loader.Load();
+  _ASSERTE(loaded);
+
+  if (loaded) {
+    MSG msg;
+    BOOL ret;
+    // Main message loop:
+    while ((ret = GetMessage(&msg, NULL, 0, 0))) {
+      if (ret == -1) {
+        break;
+      } else {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+      }
+    }
+  }
+
+  return 0;
+}