chrome/installer/launcher_support/chrome_launcher_support.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/installer/launcher_support/chrome_launcher_support.h"
   6
   7 #include <windows.h>
   8
   9 #include "base/files/file_path.h"
  10 #include "base/files/file_util.h"
  11 #include "base/strings/string16.h"
  12 #include "base/win/registry.h"
  13
  14 namespace chrome_launcher_support {
  15
  16 namespace {
  17
  18 // TODO(huangs) Refactor the constants: http://crbug.com/148538
  19 #if defined(GOOGLE_CHROME_BUILD)
  20 const wchar_t kInstallationRegKey[] =
  21     L"Software\\Google\\Update\\ClientState";
  22
  23 // Copied from chrome_appid.cc.
  24 const wchar_t kBinariesAppGuid[] = L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
  25
  26 // Copied from google_chrome_distribution.cc.
  27 const wchar_t kBrowserAppGuid[] = L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
  28
  29 // Copied frome google_chrome_sxs_distribution.cc.
  30 const wchar_t kSxSBrowserAppGuid[] = L"{4ea16ac7-fd5a-47c3-875b-dbf4a2008c20}";
  31 #else
  32 const wchar_t kInstallationRegKey[] = L"Software\\Chromium";
  33 #endif
  34
  35 // Copied from util_constants.cc.
  36 const wchar_t kChromeExe[] = L"chrome.exe";
  37 const wchar_t kUninstallStringField[] = L"UninstallString";
  38
  39 // Reads a string value from the specified product's registry key. Returns true
  40 // iff the value is present and successfully read.
  41 bool GetClientStateValue(InstallationLevel level,
  42                          const wchar_t* app_guid,
  43                          const wchar_t* value_name,
  44                          base::string16* value) {
  45   HKEY root_key = (level == USER_LEVEL_INSTALLATION) ?
  46       HKEY_CURRENT_USER : HKEY_LOCAL_MACHINE;
  47   base::string16 subkey(kInstallationRegKey);
  48   if (app_guid)
  49     subkey.append(1, L'\\').append(app_guid);
  50   base::win::RegKey reg_key;
  51   // Google Update always uses 32bit hive.
  52   if (reg_key.Open(root_key, subkey.c_str(),
  53                    KEY_QUERY_VALUE | KEY_WOW64_32KEY) == ERROR_SUCCESS) {
  54     if (reg_key.ReadValue(value_name, value) == ERROR_SUCCESS) {
  55       return true;
  56     }
  57   }
  58   return false;
  59 }
  60
  61 // Reads the path to setup.exe from the value "UninstallString" within the
  62 // specified product's registry key. Returns an empty FilePath if an error
  63 // occurs or the product is not installed at the specified level.
  64 base::FilePath GetSetupExeFromRegistry(InstallationLevel level,
  65                                        const wchar_t* app_guid) {
  66   base::string16 uninstall;
  67   if (GetClientStateValue(level, app_guid, kUninstallStringField, &uninstall)) {
  68     base::FilePath setup_exe_path(uninstall);
  69     if (base::PathExists(setup_exe_path))
  70       return setup_exe_path;
  71   }
  72   return base::FilePath();
  73 }
  74
  75 // Returns the path to an existing setup.exe at the specified level, if it can
  76 // be found via the registry.
  77 base::FilePath GetSetupExeForInstallationLevel(InstallationLevel level) {
  78   base::FilePath setup_exe_path;
  79 #if defined(GOOGLE_CHROME_BUILD)
  80   // Look in the registry for Chrome Binaries first.
  81   setup_exe_path = GetSetupExeFromRegistry(level, kBinariesAppGuid);
  82   // If the above fails, look in the registry for Chrome next.
  83   if (setup_exe_path.empty())
  84     setup_exe_path = GetSetupExeFromRegistry(level, kBrowserAppGuid);
  85   // If we fail again, then setup_exe_path would be empty.
  86 #else
  87   // For Chromium, there are no GUIDs. Just look in the Chromium registry key.
  88   setup_exe_path = GetSetupExeFromRegistry(level, nullptr);
  89 #endif
  90
  91   return setup_exe_path;
  92 }
  93
  94 // Returns the path to an installed |exe_file| (e.g. chrome.exe) at the
  95 // specified level, given |setup_exe_path| from the registry.  Returns empty
  96 // base::FilePath if none found, or if |setup_exe_path| is empty.
  97 base::FilePath FindExeRelativeToSetupExe(const base::FilePath setup_exe_path,
  98                                          const wchar_t* exe_file) {
  99   if (!setup_exe_path.empty()) {
 100     // The uninstall path contains the path to setup.exe, which is two levels
 101     // down from |exe_file|. Move up two levels (plus one to drop the file
 102     // name) and look for chrome.exe from there.
 103     base::FilePath exe_path(
 104         setup_exe_path.DirName().DirName().DirName().Append(exe_file));
 105     if (base::PathExists(exe_path))
 106       return exe_path;
 107     // By way of mild future proofing, look up one to see if there's a
 108     // |exe_file| in the version directory
 109     exe_path = setup_exe_path.DirName().DirName().Append(exe_file);
 110     if (base::PathExists(exe_path))
 111       return exe_path;
 112   }
 113   return base::FilePath();
 114 }
 115
 116 }  // namespace
 117
 118 base::FilePath GetChromePathForInstallationLevel(InstallationLevel level,
 119                                                  bool is_sxs) {
 120   if (is_sxs) {
 121 #if defined(GOOGLE_CHROME_BUILD)
 122     return FindExeRelativeToSetupExe(
 123         GetSetupExeFromRegistry(level, kSxSBrowserAppGuid), kChromeExe);
 124 #else
 125     // There is no SxS build for Chromium.
 126     return base::FilePath();
 127 #endif
 128   } else {
 129     return FindExeRelativeToSetupExe(GetSetupExeForInstallationLevel(level),
 130                                      kChromeExe);
 131   }
 132 }
 133
 134 base::FilePath GetAnyChromePath(bool is_sxs) {
 135   base::FilePath path;
 136   path = GetChromePathForInstallationLevel(SYSTEM_LEVEL_INSTALLATION, is_sxs);
 137   if (path.empty())
 138     path = GetChromePathForInstallationLevel(USER_LEVEL_INSTALLATION, is_sxs);
 139   return path;
 140 }
 141
 142 }  // namespace chrome_launcher_support