release/src/router/libcurl/lib/system_win32.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 2016, Steve Holme, <steve_holme@hotmail.com>.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at https://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  ***************************************************************************/
  22
  23 #include "curl_setup.h"
  24
  25 #if defined(WIN32)
  26
  27 #if defined(USE_WINDOWS_SSPI) || (!defined(CURL_DISABLE_TELNET) && \
  28                                   defined(USE_WINSOCK))
  29
  30 #include <curl/curl.h>
  31 #include "system_win32.h"
  32
  33 /* The last #include files should be: */
  34 #include "curl_memory.h"
  35 #include "memdebug.h"
  36
  37 #if !defined(LOAD_WITH_ALTERED_SEARCH_PATH)
  38 #define LOAD_WITH_ALTERED_SEARCH_PATH  0x00000008
  39 #endif
  40
  41 #if !defined(LOAD_LIBRARY_SEARCH_SYSTEM32)
  42 #define LOAD_LIBRARY_SEARCH_SYSTEM32   0x00000800
  43 #endif
  44
  45 /* We use our own typedef here since some headers might lack these */
  46 typedef HMODULE (APIENTRY *LOADLIBRARYEX_FN)(LPCTSTR, HANDLE, DWORD);
  47
  48 /* See function definitions in winbase.h */
  49 #ifdef UNICODE
  50 #  ifdef _WIN32_WCE
  51 #    define LOADLIBARYEX  L"LoadLibraryExW"
  52 #  else
  53 #    define LOADLIBARYEX  "LoadLibraryExW"
  54 #  endif
  55 #else
  56 #  define LOADLIBARYEX    "LoadLibraryExA"
  57 #endif
  58
  59 /*
  60  * Curl_load_library()
  61  *
  62  * This is used to dynamically load DLLs using the most secure method available
  63  * for the version of Windows that we are running on.
  64  *
  65  * Parameters:
  66  *
  67  * filename  [in] - The filename or full path of the DLL to load. If only the
  68  *                  filename is passed then the DLL will be loaded from the
  69  *                  Windows system directory.
  70  *
  71  * Returns the handle of the module on success; otherwise NULL.
  72  */
  73 HMODULE Curl_load_library(LPCTSTR filename)
  74 {
  75   HMODULE hModule = NULL;
  76   LOADLIBRARYEX_FN pLoadLibraryEx = NULL;
  77
  78   /* Get a handle to kernel32 so we can access it's functions at runtime */
  79   HMODULE hKernel32 = GetModuleHandle(TEXT("kernel32"));
  80   if(!hKernel32)
  81     return NULL;
  82
  83   /* Attempt to find LoadLibraryEx() which is only available on Windows 2000
  84      and above */
  85   pLoadLibraryEx = (LOADLIBRARYEX_FN) GetProcAddress(hKernel32, LOADLIBARYEX);
  86
  87   /* Detect if there's already a path in the filename and load the library if
  88      there is. Note: Both back slashes and forward slashes have been supported
  89      since the earlier days of DOS at an API level although they are not
  90      supported by command prompt */
  91   if(_tcspbrk(filename, TEXT("\\/")))
  92     hModule = pLoadLibraryEx ?
  93       pLoadLibraryEx(filename, NULL, LOAD_WITH_ALTERED_SEARCH_PATH) :
  94       LoadLibrary(filename);
  95   /* Detect if KB2533623 is installed, as LOAD_LIBARY_SEARCH_SYSTEM32 is only
  96      supported on Windows Vista, Windows Server 2008, Windows 7 and Windows
  97      Server 2008 R2 with this patch or natively on Windows 8 and above */
  98   else if(pLoadLibraryEx && GetProcAddress(hKernel32, "AddDllDirectory")) {
  99     /* Load the DLL from the Windows system directory */
 100     hModule = pLoadLibraryEx(filename, NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
 101   }
 102   else {
 103     /* Attempt to get the Windows system path */
 104     UINT systemdirlen = GetSystemDirectory(NULL, 0);
 105     if(systemdirlen) {
 106       /* Allocate space for the full DLL path (Room for the null terminator
 107          is included in systemdirlen) */
 108       size_t filenamelen = _tcslen(filename);
 109       TCHAR *path = malloc(sizeof(TCHAR) * (systemdirlen + 1 + filenamelen));
 110       if(path && GetSystemDirectory(path, systemdirlen)) {
 111         /* Calculate the full DLL path */
 112         _tcscpy(path + _tcslen(path), TEXT("\\"));
 113         _tcscpy(path + _tcslen(path), filename);
 114
 115         /* Load the DLL from the Windows system directory */
 116         hModule = pLoadLibraryEx ?
 117           pLoadLibraryEx(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH) :
 118           LoadLibrary(path);
 119
 120         free(path);
 121       }
 122     }
 123   }
 124
 125   return hModule;
 126 }
 127
 128 #endif /* USE_WINDOWS_SSPI || (!CURL_DISABLE_TELNET && USE_WINSOCK) */
 129
 130 #endif /* WIN32 */