lib/stat-w32.c

   1 /* Core of implementation of fstat and stat for native Windows.
   2    Copyright (C) 2017 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible.  */
  18
  19 #include <config.h>
  20
  21 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  22
  23 /* Ensure that <windows.h> defines FILE_ID_INFO.  */
  24 #undef _WIN32_WINNT
  25 #define _WIN32_WINNT _WIN32_WINNT_WIN8
  26
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <errno.h>
  30 #include <limits.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <windows.h>
  34
  35 /* Specification.  */
  36 #include "stat-w32.h"
  37
  38 #include "pathmax.h"
  39 #include "verify.h"
  40
  41 #if _GL_WINDOWS_STAT_INODES == 2
  42 /* GetFileInformationByHandleEx was introduced only in Windows Vista.  */
  43 typedef DWORD (WINAPI * GetFileInformationByHandleExFuncType) (HANDLE hFile,
  44                                                                FILE_INFO_BY_HANDLE_CLASS fiClass,
  45                                                                LPVOID lpBuffer,
  46                                                                DWORD dwBufferSize);
  47 static GetFileInformationByHandleExFuncType GetFileInformationByHandleExFunc = NULL;
  48 #endif
  49 /* GetFinalPathNameByHandle was introduced only in Windows Vista.  */
  50 typedef DWORD (WINAPI * GetFinalPathNameByHandleFuncType) (HANDLE hFile,
  51                                                            LPTSTR lpFilePath,
  52                                                            DWORD lenFilePath,
  53                                                            DWORD dwFlags);
  54 static GetFinalPathNameByHandleFuncType GetFinalPathNameByHandleFunc = NULL;
  55 static BOOL initialized = FALSE;
  56
  57 static void
  58 initialize (void)
  59 {
  60   HMODULE kernel32 = LoadLibrary ("kernel32.dll");
  61   if (kernel32 != NULL)
  62     {
  63 #if _GL_WINDOWS_STAT_INODES == 2
  64       GetFileInformationByHandleExFunc =
  65         (GetFileInformationByHandleExFuncType) GetProcAddress (kernel32, "GetFileInformationByHandleEx");
  66 #endif
  67       GetFinalPathNameByHandleFunc =
  68         (GetFinalPathNameByHandleFuncType) GetProcAddress (kernel32, "GetFinalPathNameByHandleA");
  69     }
  70   initialized = TRUE;
  71 }
  72
  73 /* Converts a FILETIME to GMT time since 1970-01-01 00:00:00.  */
  74 #if _GL_WINDOWS_STAT_TIMESPEC
  75 struct timespec
  76 _gl_convert_FILETIME_to_timespec (const FILETIME *ft)
  77 {
  78   struct timespec result;
  79   /* FILETIME: <https://msdn.microsoft.com/en-us/library/ms724284.aspx> */
  80   unsigned long long since_1601 =
  81     ((unsigned long long) ft->dwHighDateTime << 32)
  82     | (unsigned long long) ft->dwLowDateTime;
  83   if (since_1601 == 0)
  84     {
  85       result.tv_sec = 0;
  86       result.tv_nsec = 0;
  87     }
  88   else
  89     {
  90       /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
  91          leap years, in total 134774 days.  */
  92       unsigned long long since_1970 =
  93         since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
  94       result.tv_sec = since_1970 / (unsigned long long) 10000000;
  95       result.tv_nsec = (unsigned long) (since_1970 % (unsigned long long) 10000000) * 100;
  96     }
  97   return result;
  98 }
  99 #else
 100 time_t
 101 _gl_convert_FILETIME_to_POSIX (const FILETIME *ft)
 102 {
 103   /* FILETIME: <https://msdn.microsoft.com/en-us/library/ms724284.aspx> */
 104   unsigned long long since_1601 =
 105     ((unsigned long long) ft->dwHighDateTime << 32)
 106     | (unsigned long long) ft->dwLowDateTime;
 107   if (since_1601 == 0)
 108     return 0;
 109   else
 110     {
 111       /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
 112          leap years, in total 134774 days.  */
 113       unsigned long long since_1970 =
 114         since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
 115       return since_1970 / (unsigned long long) 10000000;
 116     }
 117 }
 118 #endif
 119
 120 /* Fill *BUF with information about the file designated by H.
 121    PATH is the file name, if known, otherwise NULL.
 122    Return 0 if successful, or -1 with errno set upon failure.  */
 123 int
 124 _gl_fstat_by_handle (HANDLE h, const char *path, struct stat *buf)
 125 {
 126   /* GetFileType
 127      <https://msdn.microsoft.com/en-us/library/aa364960.aspx> */
 128   DWORD type = GetFileType (h);
 129   if (type == FILE_TYPE_DISK)
 130     {
 131       if (!initialized)
 132         initialize ();
 133
 134       /* st_mode can be determined through
 135          GetFileAttributesEx
 136          <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
 137          <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
 138          or through
 139          GetFileInformationByHandle
 140          <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
 141          <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
 142          or through
 143          GetFileInformationByHandleEx with argument FileBasicInfo
 144          <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 145          <https://msdn.microsoft.com/en-us/library/aa364217.aspx>
 146          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 147       BY_HANDLE_FILE_INFORMATION info;
 148       if (! GetFileInformationByHandle (h, &info))
 149         goto failed;
 150
 151       /* Test for error conditions before starting to fill *buf.  */
 152       if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0)
 153         {
 154           errno = EOVERFLOW;
 155           return -1;
 156         }
 157
 158 #if _GL_WINDOWS_STAT_INODES
 159       /* st_ino can be determined through
 160          GetFileInformationByHandle
 161          <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
 162          <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
 163          as 64 bits, or through
 164          GetFileInformationByHandleEx with argument FileIdInfo
 165          <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 166          <https://msdn.microsoft.com/en-us/library/hh802691.aspx>
 167          as 128 bits.
 168          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_WIN8 or higher.  */
 169       /* Experiments show that GetFileInformationByHandleEx does not provide
 170          much more information than GetFileInformationByHandle:
 171            * The dwVolumeSerialNumber from GetFileInformationByHandle is equal
 172              to the low 32 bits of the 64-bit VolumeSerialNumber from
 173              GetFileInformationByHandleEx, and is apparently sufficient for
 174              identifying the device.
 175            * The nFileIndex from GetFileInformationByHandle is equal to the low
 176              64 bits of the 128-bit FileId from GetFileInformationByHandleEx,
 177              and the high 64 bits of this 128-bit FileId are zero.
 178            * On a FAT file system, GetFileInformationByHandleEx fails with error
 179              ERROR_INVALID_PARAMETER, whereas GetFileInformationByHandle
 180              succeeds.
 181            * On a CIFS/SMB file system, GetFileInformationByHandleEx fails with
 182              error ERROR_INVALID_LEVEL, whereas GetFileInformationByHandle
 183              succeeds.  */
 184 # if _GL_WINDOWS_STAT_INODES == 2
 185       if (GetFileInformationByHandleExFunc != NULL)
 186         {
 187           FILE_ID_INFO id;
 188           if (GetFileInformationByHandleExFunc (h, FileIdInfo, &id, sizeof (id)))
 189             {
 190               buf->st_dev = id.VolumeSerialNumber;
 191               verify (sizeof (ino_t) == sizeof (id.FileId));
 192               memcpy (&buf->st_ino, &id.FileId, sizeof (ino_t));
 193               goto ino_done;
 194             }
 195           else
 196             {
 197               switch (GetLastError ())
 198                 {
 199                 case ERROR_INVALID_PARAMETER: /* older Windows version, or FAT */
 200                 case ERROR_INVALID_LEVEL: /* CIFS/SMB file system */
 201                   goto fallback;
 202                 default:
 203                   goto failed;
 204                 }
 205             }
 206         }
 207      fallback: ;
 208       /* Fallback for older Windows versions.  */
 209       buf->st_dev = info.dwVolumeSerialNumber;
 210       buf->st_ino._gl_ino[0] = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
 211       buf->st_ino._gl_ino[1] = 0;
 212      ino_done: ;
 213 # else /* _GL_WINDOWS_STAT_INODES == 1 */
 214       buf->st_dev = info.dwVolumeSerialNumber;
 215       buf->st_ino = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
 216 # endif
 217 #else
 218       /* st_ino is not wide enough for identifying a file on a device.
 219          Without st_ino, st_dev is pointless.  */
 220       buf->st_dev = 0;
 221       buf->st_ino = 0;
 222 #endif
 223
 224       /* st_mode.  */
 225       unsigned int mode =
 226         /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ?  */
 227         ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG)
 228         | S_IREAD_UGO
 229         | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO);
 230       if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
 231         {
 232           /* Determine whether the file is executable by looking at the file
 233              name suffix.
 234              If the file name is already known, use it. Otherwise, for
 235              non-empty files, it can be determined through
 236              GetFinalPathNameByHandle
 237              <https://msdn.microsoft.com/en-us/library/aa364962.aspx>
 238              or through
 239              GetFileInformationByHandleEx with argument FileNameInfo
 240              <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 241              <https://msdn.microsoft.com/en-us/library/aa364388.aspx>
 242              Both require -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 243           if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0)
 244             {
 245               char fpath[PATH_MAX];
 246               if (path != NULL
 247                   || (GetFinalPathNameByHandleFunc != NULL
 248                       && GetFinalPathNameByHandleFunc (h, fpath, sizeof (fpath), VOLUME_NAME_NONE)
 249                          < sizeof (fpath)
 250                       && (path = fpath, 1)))
 251                 {
 252                   const char *last_dot = NULL;
 253                   const char *p;
 254                   for (p = path; *p != '\0'; p++)
 255                     if (*p == '.')
 256                       last_dot = p;
 257                   if (last_dot != NULL)
 258                     {
 259                       const char *suffix = last_dot + 1;
 260                       if (_stricmp (suffix, "exe") == 0
 261                           || _stricmp (suffix, "bat") == 0
 262                           || _stricmp (suffix, "cmd") == 0
 263                           || _stricmp (suffix, "com") == 0)
 264                         mode |= S_IEXEC_UGO;
 265                     }
 266                 }
 267               else
 268                 /* Cannot determine file name.  Pretend that it is executable.  */
 269                 mode |= S_IEXEC_UGO;
 270             }
 271         }
 272       buf->st_mode = mode;
 273
 274       /* st_nlink can be determined through
 275          GetFileInformationByHandle
 276          <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
 277          <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
 278          or through
 279          GetFileInformationByHandleEx with argument FileStandardInfo
 280          <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 281          <https://msdn.microsoft.com/en-us/library/aa364401.aspx>
 282          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 283       buf->st_nlink = (info.nNumberOfLinks > SHRT_MAX ? SHRT_MAX : info.nNumberOfLinks);
 284
 285       /* There's no easy way to map the Windows SID concept to an integer.  */
 286       buf->st_uid = 0;
 287       buf->st_gid = 0;
 288
 289       /* st_rdev is irrelevant for normal files and directories.  */
 290       buf->st_rdev = 0;
 291
 292       /* st_size can be determined through
 293          GetFileSizeEx
 294          <https://msdn.microsoft.com/en-us/library/aa364957.aspx>
 295          or through
 296          GetFileAttributesEx
 297          <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
 298          <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
 299          or through
 300          GetFileInformationByHandle
 301          <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
 302          <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
 303          or through
 304          GetFileInformationByHandleEx with argument FileStandardInfo
 305          <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 306          <https://msdn.microsoft.com/en-us/library/aa364401.aspx>
 307          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 308       if (sizeof (buf->st_size) <= 4)
 309         /* Range check already done above.  */
 310         buf->st_size = info.nFileSizeLow;
 311       else
 312         buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow;
 313
 314       /* st_atime, st_mtime, st_ctime can be determined through
 315          GetFileTime
 316          <https://msdn.microsoft.com/en-us/library/ms724320.aspx>
 317          or through
 318          GetFileAttributesEx
 319          <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
 320          <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
 321          or through
 322          GetFileInformationByHandle
 323          <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
 324          <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
 325          or through
 326          GetFileInformationByHandleEx with argument FileBasicInfo
 327          <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
 328          <https://msdn.microsoft.com/en-us/library/aa364217.aspx>
 329          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 330 #if _GL_WINDOWS_STAT_TIMESPEC
 331       buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime);
 332       buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime);
 333       buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime);
 334 #else
 335       buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime);
 336       buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime);
 337       buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime);
 338 #endif
 339
 340       return 0;
 341     }
 342   else if (type == FILE_TYPE_CHAR || type == FILE_TYPE_PIPE)
 343     {
 344       buf->st_dev = 0;
 345 #if _GL_WINDOWS_STAT_INODES == 2
 346       buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0;
 347 #else
 348       buf->st_ino = 0;
 349 #endif
 350       buf->st_mode = (type == FILE_TYPE_PIPE ? _S_IFIFO : _S_IFCHR);
 351       buf->st_nlink = 1;
 352       buf->st_uid = 0;
 353       buf->st_gid = 0;
 354       buf->st_rdev = 0;
 355       if (type == FILE_TYPE_PIPE)
 356         {
 357           /* PeekNamedPipe
 358              <https://msdn.microsoft.com/en-us/library/aa365779.aspx> */
 359           DWORD bytes_available;
 360           if (PeekNamedPipe (h, NULL, 0, NULL, &bytes_available, NULL))
 361             buf->st_size = bytes_available;
 362           else
 363             buf->st_size = 0;
 364         }
 365       else
 366         buf->st_size = 0;
 367 #if _GL_WINDOWS_STAT_TIMESPEC
 368       buf->st_atim.tv_sec = 0; buf->st_atim.tv_nsec = 0;
 369       buf->st_mtim.tv_sec = 0; buf->st_mtim.tv_nsec = 0;
 370       buf->st_ctim.tv_sec = 0; buf->st_ctim.tv_nsec = 0;
 371 #else
 372       buf->st_atime = 0;
 373       buf->st_mtime = 0;
 374       buf->st_ctime = 0;
 375 #endif
 376       return 0;
 377     }
 378   else
 379     {
 380       errno = ENOENT;
 381       return -1;
 382     }
 383
 384  failed:
 385   {
 386     DWORD error = GetLastError ();
 387     #if 0
 388     fprintf (stderr, "_gl_fstat_by_handle error 0x%x\n", (unsigned int) error);
 389     #endif
 390     switch (error)
 391       {
 392       case ERROR_ACCESS_DENIED:
 393       case ERROR_SHARING_VIOLATION:
 394         errno = EACCES;
 395         break;
 396
 397       case ERROR_OUTOFMEMORY:
 398         errno = ENOMEM;
 399         break;
 400
 401       case ERROR_WRITE_FAULT:
 402       case ERROR_READ_FAULT:
 403       case ERROR_GEN_FAILURE:
 404         errno = EIO;
 405         break;
 406
 407       default:
 408         errno = EINVAL;
 409         break;
 410       }
 411     return -1;
 412   }
 413 }
 414
 415 #else
 416
 417 /* This declaration is solely to ensure that after preprocessing
 418    this file is never empty.  */
 419 typedef int dummy;
 420
 421 #endif