wimlib.net Git - wimlib/blob - src/win32.c

   1 #include "config.h"
   2
   3 #if defined(__CYGWIN__) || defined(__WIN32__)
   4 #include <windows.h>
   5 #       ifdef ERROR
   6 #               undef ERROR
   7 #       endif
   8
   9 #include "wimlib_internal.h"
  10
  11
  12 #ifdef ENABLE_ERROR_MESSAGES
  13 void win32_error(u32 err_code)
  14 {
  15         char *buffer;
  16         DWORD nchars;
  17         nchars = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
  18                                 NULL, err_code, 0,
  19                                 (char*)&buffer, 0, NULL);
  20         if (nchars == 0) {
  21                 ERROR("Error printing error message! "
  22                       "Computer will self-destruct in 3 seconds.");
  23         } else {
  24                 ERROR("Win32 error: %s", buffer);
  25                 LocalFree(buffer);
  26         }
  27 }
  28 #else
  29 #define win32_error(err_code)
  30 #endif
  31
  32 void *win32_open_file_readonly(const void *path)
  33 {
  34         return CreateFileW((const wchar_t*)path,
  35                            FILE_READ_DATA |
  36                                FILE_READ_ATTRIBUTES |
  37                                READ_CONTROL |
  38                                ACCESS_SYSTEM_SECURITY,
  39                            FILE_SHARE_READ,
  40                            NULL, /* lpSecurityAttributes */
  41                            OPEN_EXISTING,
  42                            FILE_FLAG_BACKUP_SEMANTICS |
  43                                FILE_FLAG_OPEN_REPARSE_POINT,
  44                            NULL /* hTemplateFile */);
  45 }
  46
  47 int win32_read_file(const char *filename,
  48                     void *handle, u64 offset, size_t size, u8 *buf)
  49 {
  50         HANDLE h = handle;
  51         DWORD err;
  52         DWORD bytesRead;
  53         LARGE_INTEGER liOffset = {.QuadPart = offset};
  54
  55         wimlib_assert(size <= 0xffffffff);
  56
  57         if (SetFilePointerEx(h, liOffset, NULL, FILE_BEGIN))
  58                 if (ReadFile(h, buf, size, &bytesRead, NULL) && bytesRead == size)
  59                         return 0;
  60         err = GetLastError();
  61         ERROR("Error reading \"%s\"", filename);
  62         win32_error(err);
  63         return WIMLIB_ERR_READ;
  64 }
  65
  66 void win32_close_file(void *handle)
  67 {
  68         CloseHandle((HANDLE)handle);
  69 }
  70
  71 static bool win32_modify_privilege(const char *privilege, bool enable)
  72 {
  73         HANDLE hToken;
  74         LUID luid;
  75         TOKEN_PRIVILEGES newState;
  76         bool ret = false;
  77
  78         DEBUG("%s privilege %s",
  79               enable ? "Enabling" : "Disabling", privilege);
  80
  81         if (!OpenProcessToken(GetCurrentProcess(),
  82                               TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
  83                               &hToken))
  84         {
  85                 DEBUG("OpenProcessToken() failed");
  86                 goto out;
  87         }
  88
  89         if (!LookupPrivilegeValue(NULL, privilege, &luid)) {
  90                 DEBUG("LookupPrivilegeValue() failed");
  91                 goto out;
  92         }
  93
  94         newState.PrivilegeCount = 1;
  95         newState.Privileges[0].Luid = luid;
  96         newState.Privileges[0].Attributes = (enable ? SE_PRIVILEGE_ENABLED : 0);
  97         ret = AdjustTokenPrivileges(hToken, FALSE, &newState, 0, NULL, NULL);
  98         if (!ret)
  99                 DEBUG("AdjustTokenPrivileges() failed");
 100         CloseHandle(hToken);
 101 out:
 102         if (!ret) {
 103                 DWORD err = GetLastError();
 104                 win32_error(err);
 105                 WARNING("Failed to %s privilege %s",
 106                         enable ? "enable" : "disable", privilege);
 107                 WARNING("The program will continue, but if permission issues are "
 108                         "encountered, you may need to run this program as the administrator");
 109         }
 110         return ret;
 111 }
 112
 113 bool win32_acquire_privilege(const char *privilege)
 114 {
 115         return win32_modify_privilege(privilege, true);
 116 }
 117
 118 bool win32_release_privilege(const char *privilege)
 119 {
 120         return win32_modify_privilege(privilege, false);
 121 }
 122
 123
 124 #endif /* __CYGWIN__ || __WIN32__ */