Add a self-destruct mechanism to user-level Chrome Frame when it detects that system-level Chrome...

chrome_frame/chrome_frame_helper_main.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.

[grt (UTC plus 2), 2011/05/25 16:10:07]

2011

[robertshield, 2011/05/26 15:14:28]

Done.

 // 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 <objbase.h>
 #include <windows.h>
+#include <string>
 
 #include "chrome_frame/crash_server_init.h"
+#include "chrome_frame/chrome_frame_helper_util.h"

[grt (UTC plus 2), 2011/05/25 16:10:07]

move this above the previous line

[robertshield, 2011/05/26 15:14:28]

Done.

 
 // Window class and window names.

[grt (UTC plus 2), 2011/05/25 16:10:07]

nit: wrap as much of this as reasonable in namespace{}

[robertshield, 2011/05/26 15:14:28]

Done.

 const wchar_t kChromeFrameHelperWindowClassName[] =
     L"ChromeFrameHelperWindowClass";
 const wchar_t kChromeFrameHelperWindowName[] =
     L"ChromeFrameHelperWindowName";
 
+const wchar_t kChromeFrameClientStateKey[] =
+    L"Software\\Google\\Update\\ClientState\\"
+    L"{8BA986DA-5100-405E-AA35-86F34A02ACBF}\\";

[grt (UTC plus 2), 2011/05/25 16:10:07]

nit: I don't think we usually have a trailing separator in these sorts of
strings.

[robertshield, 2011/05/26 15:14:28]

Done.

+const wchar_t kChromeFrameUninstallCmdExeValue[] = L"UninstallString";
+const wchar_t kChromeFrameUninstallCmdArgsValue[] = L"UninstallArguments";
+
+const wchar_t kFirstRunArg[] = L"--first-run";
+const wchar_t kForceUninstall[] = L"--force-uninstall";
+
 // 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();
     }
@@ skipping 90 matching lines @@
   wcex.lpszClassName  = kChromeFrameHelperWindowClassName;
   RegisterClassEx(&wcex);
 
   HWND hwnd = CreateWindow(kChromeFrameHelperWindowClassName,
       kChromeFrameHelperWindowName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0,
       CW_USEDEFAULT, 0, NULL, NULL, hinstance, NULL);
 
   return hwnd;
 }
 
+
+// This method runs the user-level Chrome Frame uninstall command. This is
+// intended to allow it to delegate to an existing system-level install.
+bool UninstallUserLevelChromeFrame() {
+  bool success = false;
+  HKEY reg_handle = NULL;
+  wchar_t reg_path_buffer[MAX_PATH] = {0};
+  LONG result = RegOpenKeyEx(HKEY_CURRENT_USER,
+                             kChromeFrameClientStateKey,
+                             0,
+                             KEY_READ,

[grt (UTC plus 2), 2011/05/25 16:10:07]

KEY_READ -> KEY_QUERY_VALUE

[robertshield, 2011/05/26 15:14:28]

Done.

+                             &reg_handle);
+  if (result == ERROR_SUCCESS) {
+    wchar_t exe_buffer[MAX_PATH] = {0};
+    wchar_t args_buffer[MAX_PATH] = {0};
+    LONG exe_result = ReadValue(reg_handle,
+                                kChromeFrameUninstallCmdExeValue,
+                                MAX_PATH,
+                                exe_buffer);
+    LONG args_result = ReadValue(reg_handle,
+                                 kChromeFrameUninstallCmdArgsValue,
+                                 MAX_PATH,
+                                 args_buffer);
+

[grt (UTC plus 2), 2011/05/25 16:10:07]

Consider moving RegCloseKey(reg_handle); reg_handle = NULL; here.

[robertshield, 2011/05/26 15:14:28]

Done.

+    if (exe_result == ERROR_SUCCESS && args_result == ERROR_SUCCESS) {
+      STARTUPINFO startup_info = {0};
+      startup_info.cb = sizeof(startup_info);
+      startup_info.dwFlags = STARTF_USESHOWWINDOW;
+      startup_info.wShowWindow = SW_SHOW;
+      PROCESS_INFORMATION process_info = {0};
+
+      // Quote the command string in the args.
+      std::wstring args(L"\"");

[amit, 2011/05/24 22:36:50]

nit: size concern - if we are using std::string just for this and not anywhere
else then a large enough buffer and sprintf variant should be ok?

[grt (UTC plus 2), 2011/05/25 16:10:07]

Agreed.  The rest of the code seems to bend over to not use std::basic_string. 
May as well do the same here.

[robertshield, 2011/05/26 15:14:28]

Done.

[robertshield, 2011/05/26 15:14:28]

Done.

+      args += exe_buffer;
+      args += L"\" ";
+      args += args_buffer;
+      // Make sure the uninstall is silent.
+      args += L"\" ";
+      args += kForceUninstall;
+
+      if (CreateProcess(exe_buffer, &args[0],
+                        NULL, NULL, FALSE, 0, NULL, NULL,
+                        &startup_info, &process_info)) {
+        // Close handles.
+        CloseHandle(process_info.hThread);
+        CloseHandle(process_info.hProcess);
+        success = true;
+      }
+    }
+    RegCloseKey(reg_handle);
+  }
+
+  return success;
+}
+
+
 int APIENTRY wWinMain(HINSTANCE hinstance, HINSTANCE, wchar_t*, int show_cmd) {
   const wchar_t* cmd_line = ::GetCommandLine();
   google_breakpad::scoped_ptr<google_breakpad::ExceptionHandler> breakpad(
       InitializeCrashReporting(cmd_line));
 
+  if (IsSystemLevelChromeFrameInstalled()) {
+    // If we're running at startup, check for system-level Chrome Frame
+    // installations. If we have one, time
+    // to bail, also schedule user-level CF to be uninstalled at next logon.
+    const wchar_t* cmd_line = ::GetCommandLine();
+    if (cmd_line && wcsstr(cmd_line, kFirstRunArg) != NULL) {
+      bool uninstalled = UninstallUserLevelChromeFrame();
+      _ASSERTE(uninstalled);
+    }
+    return 0;
+  }
+
   // 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);
       }
     }
   }
 
   UnregisterClass(kChromeFrameHelperWindowClassName, hinstance);
   return 0;
 }