onlineupdate/source/update/updater/loaddlls.cxx

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6
   7 #ifdef _WIN32
   8 #ifndef UNICODE
   9 #define UNICODE
  10 #endif
  11 #include <windows.h>
  12
  13 // Delayed load libraries are loaded when the first symbol is used.
  14 // The following ensures that we load the delayed loaded libraries from the
  15 // system directory.
  16 struct AutoLoadSystemDependencies
  17 {
  18     AutoLoadSystemDependencies()
  19     {
  20         // Remove the current directory from the search path for dynamically loaded
  21         // DLLs as a precaution.  This call has no effect for delay load DLLs.
  22         SetDllDirectory(L"");
  23
  24         HMODULE module = ::GetModuleHandleW(L"kernel32.dll");
  25         if (module)
  26         {
  27             // SetDefaultDllDirectories is always available on Windows 8 and above. It
  28             // is also available on Windows Vista, Windows Server 2008, and
  29             // Windows 7 when MS KB2533623 has been applied.
  30             decltype(SetDefaultDllDirectories)* setDefaultDllDirectories =
  31                 (decltype(SetDefaultDllDirectories)*) GetProcAddress(module, "SetDefaultDllDirectories");
  32             if (setDefaultDllDirectories)
  33             {
  34                 setDefaultDllDirectories(LOAD_LIBRARY_SEARCH_SYSTEM32);
  35                 return;
  36             }
  37         }
  38
  39         // TODO: moggi: do we need all that code?
  40         // When SetDefaultDllDirectories is not available, fallback to preloading
  41         // dlls. The order that these are loaded does not matter since they are
  42         // loaded using the LOAD_WITH_ALTERED_SEARCH_PATH flag.
  43 #ifdef HAVE_64BIT_BUILD
  44         // DLLs for Firefox x64 on Windows 7 (x64).
  45         // Note: dwmapi.dll is preloaded since a crash will try to load it from the
  46         // application's directory.
  47         static LPCWSTR delayDLLs[] = { L"apphelp.dll",
  48                                        L"cryptbase.dll",
  49                                        L"cryptsp.dll",
  50                                        L"dwmapi.dll",
  51                                        L"mpr.dll",
  52                                        L"ntmarta.dll",
  53                                        L"profapi.dll",
  54                                        L"propsys.dll",
  55                                        L"sspicli.dll",
  56                                        L"wsock32.dll"
  57                                      };
  58
  59 #else
  60         // DLLs for Firefox x86 on Windows XP through Windows 7 (x86 and x64).
  61         // Note: dwmapi.dll is preloaded since a crash will try to load it from the
  62         // application's directory.
  63         static LPCWSTR delayDLLs[] = { L"apphelp.dll",
  64                                        L"crypt32.dll",
  65                                        L"cryptbase.dll",
  66                                        L"cryptsp.dll",
  67                                        L"dwmapi.dll",
  68                                        L"mpr.dll",
  69                                        L"msasn1.dll",
  70                                        L"ntmarta.dll",
  71                                        L"profapi.dll",
  72                                        L"propsys.dll",
  73                                        L"psapi.dll",
  74                                        L"secur32.dll",
  75                                        L"sspicli.dll",
  76                                        L"userenv.dll",
  77                                        L"uxtheme.dll",
  78                                        L"ws2_32.dll",
  79                                        L"ws2help.dll",
  80                                        L"wsock32.dll"
  81                                      };
  82 #endif
  83
  84         WCHAR systemDirectory[MAX_PATH + 1] = { L'\0' };
  85         // If GetSystemDirectory fails we accept that we'll load the DLLs from the
  86         // normal search path.
  87         GetSystemDirectoryW(systemDirectory, MAX_PATH + 1);
  88         size_t systemDirLen = wcslen(systemDirectory);
  89
  90         // Make the system directory path terminate with a slash
  91         if (systemDirectory[systemDirLen - 1] != L'\\' && systemDirLen)
  92         {
  93             systemDirectory[systemDirLen] = L'\\';
  94             ++systemDirLen;
  95             // No need to re-null terminate
  96         }
  97
  98         // For each known DLL ensure it is loaded from the system32 directory
  99         for (size_t i = 0; i < sizeof(delayDLLs) / sizeof(delayDLLs[0]); ++i)
 100         {
 101             size_t fileLen = wcslen(delayDLLs[i]);
 102             wcsncpy(systemDirectory + systemDirLen, delayDLLs[i],
 103                     MAX_PATH - systemDirLen);
 104             if (systemDirLen + fileLen <= MAX_PATH)
 105             {
 106                 systemDirectory[systemDirLen + fileLen] = L'\0';
 107             }
 108             else
 109             {
 110                 systemDirectory[MAX_PATH] = L'\0';
 111             }
 112             LPCWSTR fullModulePath = systemDirectory; // just for code readability
 113             // LOAD_WITH_ALTERED_SEARCH_PATH makes a dll look in its own directory for
 114             // dependencies and is only available on Win 7 and below.
 115             LoadLibraryExW(fullModulePath, nullptr, LOAD_WITH_ALTERED_SEARCH_PATH);
 116         }
 117     }
 118 } loadDLLs;
 119 #endif