lib/stat-w32.c

   1 /* Core of implementation of fstat and stat for native Windows.
   2    Copyright (C) 2017-2024 Free Software Foundation, Inc.
   3
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8
   9    This file 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 Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible.  */
  18
  19 #include <config.h>
  20
  21 #if defined _WIN32 && ! defined __CYGWIN__
  22
  23 /* Attempt to make <windows.h> define FILE_ID_INFO.
  24    But ensure that the redefinition of _WIN32_WINNT does not make us assume
  25    Windows Vista or newer when building for an older version of Windows.  */
  26 #if HAVE_SDKDDKVER_H
  27 # include <sdkddkver.h>
  28 # if _WIN32_WINNT >= _WIN32_WINNT_VISTA
  29 #  define WIN32_ASSUME_VISTA 1
  30 # else
  31 #  define WIN32_ASSUME_VISTA 0
  32 # endif
  33 # if !defined _WIN32_WINNT || (_WIN32_WINNT < _WIN32_WINNT_WIN8)
  34 #  undef _WIN32_WINNT
  35 #  define _WIN32_WINNT _WIN32_WINNT_WIN8
  36 # endif
  37 #else
  38 # define WIN32_ASSUME_VISTA (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
  39 #endif
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <errno.h>
  44 #include <limits.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 #include <windows.h>
  48
  49 /* Specification.  */
  50 #include "stat-w32.h"
  51
  52 #include "pathmax.h"
  53
  54 /* Don't assume that UNICODE is not defined.  */
  55 #undef LoadLibrary
  56 #define LoadLibrary LoadLibraryA
  57 #undef GetFinalPathNameByHandle
  58 #define GetFinalPathNameByHandle GetFinalPathNameByHandleA
  59
  60 /* Older mingw headers do not define VOLUME_NAME_NONE.  */
  61 #ifndef VOLUME_NAME_NONE
  62 # define VOLUME_NAME_NONE 4
  63 #endif
  64
  65 #if !WIN32_ASSUME_VISTA
  66
  67 /* Avoid warnings from gcc -Wcast-function-type.  */
  68 # define GetProcAddress \
  69    (void *) GetProcAddress
  70
  71 # if _GL_WINDOWS_STAT_INODES == 2
  72 /* GetFileInformationByHandleEx was introduced only in Windows Vista.  */
  73 typedef DWORD (WINAPI * GetFileInformationByHandleExFuncType) (HANDLE hFile,
  74                                                                FILE_INFO_BY_HANDLE_CLASS fiClass,
  75                                                                LPVOID lpBuffer,
  76                                                                DWORD dwBufferSize);
  77 static GetFileInformationByHandleExFuncType GetFileInformationByHandleExFunc = NULL;
  78 # endif
  79 /* GetFinalPathNameByHandle was introduced only in Windows Vista.  */
  80 typedef DWORD (WINAPI * GetFinalPathNameByHandleFuncType) (HANDLE hFile,
  81                                                            LPSTR lpFilePath,
  82                                                            DWORD lenFilePath,
  83                                                            DWORD dwFlags);
  84 static GetFinalPathNameByHandleFuncType GetFinalPathNameByHandleFunc = NULL;
  85 static BOOL initialized = FALSE;
  86
  87 static void
  88 initialize (void)
  89 {
  90   HMODULE kernel32 = LoadLibrary ("kernel32.dll");
  91   if (kernel32 != NULL)
  92     {
  93 # if _GL_WINDOWS_STAT_INODES == 2
  94       GetFileInformationByHandleExFunc =
  95         (GetFileInformationByHandleExFuncType) GetProcAddress (kernel32, "GetFileInformationByHandleEx");
  96 # endif
  97       GetFinalPathNameByHandleFunc =
  98         (GetFinalPathNameByHandleFuncType) GetProcAddress (kernel32, "GetFinalPathNameByHandleA");
  99     }
 100   initialized = TRUE;
 101 }
 102
 103 #else
 104
 105 # define GetFileInformationByHandleExFunc GetFileInformationByHandleEx
 106 # define GetFinalPathNameByHandleFunc GetFinalPathNameByHandle
 107
 108 #endif
 109
 110 /* Converts a FILETIME to GMT time since 1970-01-01 00:00:00.  */
 111 #if _GL_WINDOWS_STAT_TIMESPEC
 112 struct timespec
 113 _gl_convert_FILETIME_to_timespec (const FILETIME *ft)
 114 {
 115   struct timespec result;
 116   /* FILETIME: <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-filetime> */
 117   unsigned long long since_1601 =
 118     ((unsigned long long) ft->dwHighDateTime << 32)
 119     | (unsigned long long) ft->dwLowDateTime;
 120   if (since_1601 == 0)
 121     {
 122       result.tv_sec = 0;
 123       result.tv_nsec = 0;
 124     }
 125   else
 126     {
 127       /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
 128          leap years, in total 134774 days.  */
 129       unsigned long long since_1970 =
 130         since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
 131       result.tv_sec = since_1970 / (unsigned long long) 10000000;
 132       result.tv_nsec = (unsigned long) (since_1970 % (unsigned long long) 10000000) * 100;
 133     }
 134   return result;
 135 }
 136 #else
 137 time_t
 138 _gl_convert_FILETIME_to_POSIX (const FILETIME *ft)
 139 {
 140   /* FILETIME: <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-filetime> */
 141   unsigned long long since_1601 =
 142     ((unsigned long long) ft->dwHighDateTime << 32)
 143     | (unsigned long long) ft->dwLowDateTime;
 144   if (since_1601 == 0)
 145     return 0;
 146   else
 147     {
 148       /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
 149          leap years, in total 134774 days.  */
 150       unsigned long long since_1970 =
 151         since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
 152       return since_1970 / (unsigned long long) 10000000;
 153     }
 154 }
 155 #endif
 156
 157 /* Fill *BUF with information about the file designated by H.
 158    PATH is the file name, if known, otherwise NULL.
 159    Return 0 if successful, or -1 with errno set upon failure.  */
 160 int
 161 _gl_fstat_by_handle (HANDLE h, const char *path, struct stat *buf)
 162 {
 163   /* GetFileType
 164      <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfiletype> */
 165   DWORD type = GetFileType (h);
 166   if (type == FILE_TYPE_DISK)
 167     {
 168 #if !WIN32_ASSUME_VISTA
 169       if (!initialized)
 170         initialize ();
 171 #endif
 172
 173       /* st_mode can be determined through
 174          GetFileAttributesEx
 175          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileattributesexa>
 176          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_win32_file_attribute_data>
 177          or through
 178          GetFileInformationByHandle
 179          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle>
 180          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information>
 181          or through
 182          GetFileInformationByHandleEx with argument FileBasicInfo
 183          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 184          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_basic_info>
 185          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 186       BY_HANDLE_FILE_INFORMATION info;
 187       if (! GetFileInformationByHandle (h, &info))
 188         goto failed;
 189
 190       /* Test for error conditions before starting to fill *buf.  */
 191       if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0)
 192         {
 193           errno = EOVERFLOW;
 194           return -1;
 195         }
 196
 197 #if _GL_WINDOWS_STAT_INODES
 198       /* st_ino can be determined through
 199          GetFileInformationByHandle
 200          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle>
 201          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information>
 202          as 64 bits, or through
 203          GetFileInformationByHandleEx with argument FileIdInfo
 204          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 205          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_id_info>
 206          as 128 bits.
 207          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_WIN8 or higher.  */
 208       /* Experiments show that GetFileInformationByHandleEx does not provide
 209          much more information than GetFileInformationByHandle:
 210            * The dwVolumeSerialNumber from GetFileInformationByHandle is equal
 211              to the low 32 bits of the 64-bit VolumeSerialNumber from
 212              GetFileInformationByHandleEx, and is apparently sufficient for
 213              identifying the device.
 214            * The nFileIndex from GetFileInformationByHandle is equal to the low
 215              64 bits of the 128-bit FileId from GetFileInformationByHandleEx,
 216              and the high 64 bits of this 128-bit FileId are zero.
 217            * On a FAT file system, GetFileInformationByHandleEx fails with error
 218              ERROR_INVALID_PARAMETER, whereas GetFileInformationByHandle
 219              succeeds.
 220            * On a CIFS/SMB file system, GetFileInformationByHandleEx fails with
 221              error ERROR_INVALID_LEVEL, whereas GetFileInformationByHandle
 222              succeeds.  */
 223 # if _GL_WINDOWS_STAT_INODES == 2
 224       if (GetFileInformationByHandleExFunc != NULL)
 225         {
 226           FILE_ID_INFO id;
 227           if (GetFileInformationByHandleExFunc (h, FileIdInfo, &id, sizeof (id)))
 228             {
 229               buf->st_dev = id.VolumeSerialNumber;
 230               static_assert (sizeof (ino_t) == sizeof (id.FileId));
 231               memcpy (&buf->st_ino, &id.FileId, sizeof (ino_t));
 232               goto ino_done;
 233             }
 234           else
 235             {
 236               switch (GetLastError ())
 237                 {
 238                 case ERROR_INVALID_PARAMETER: /* older Windows version, or FAT */
 239                 case ERROR_INVALID_LEVEL: /* CIFS/SMB file system */
 240                   goto fallback;
 241                 default:
 242                   goto failed;
 243                 }
 244             }
 245         }
 246      fallback: ;
 247       /* Fallback for older Windows versions.  */
 248       buf->st_dev = info.dwVolumeSerialNumber;
 249       buf->st_ino._gl_ino[0] = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
 250       buf->st_ino._gl_ino[1] = 0;
 251      ino_done: ;
 252 # else /* _GL_WINDOWS_STAT_INODES == 1 */
 253       buf->st_dev = info.dwVolumeSerialNumber;
 254       buf->st_ino = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
 255 # endif
 256 #else
 257       /* st_ino is not wide enough for identifying a file on a device.
 258          Without st_ino, st_dev is pointless.  */
 259       buf->st_dev = 0;
 260       buf->st_ino = 0;
 261 #endif
 262
 263       /* st_mode.  */
 264       unsigned int mode =
 265         /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ?  */
 266         ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG)
 267         | S_IREAD_UGO
 268         | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO);
 269       if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
 270         {
 271           /* Determine whether the file is executable by looking at the file
 272              name suffix.
 273              If the file name is already known, use it. Otherwise, for
 274              non-empty files, it can be determined through
 275              GetFinalPathNameByHandle
 276              <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfinalpathnamebyhandlea>
 277              or through
 278              GetFileInformationByHandleEx with argument FileNameInfo
 279              <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 280              <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_name_info>
 281              Both require -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 282           if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0)
 283             {
 284               char fpath[PATH_MAX];
 285               if (path != NULL
 286                   || (GetFinalPathNameByHandleFunc != NULL
 287                       && GetFinalPathNameByHandleFunc (h, fpath, sizeof (fpath), VOLUME_NAME_NONE)
 288                          < sizeof (fpath)
 289                       && (path = fpath, 1)))
 290                 {
 291                   const char *last_dot = NULL;
 292                   const char *p;
 293                   for (p = path; *p != '\0'; p++)
 294                     if (*p == '.')
 295                       last_dot = p;
 296                   if (last_dot != NULL)
 297                     {
 298                       const char *suffix = last_dot + 1;
 299                       if (_stricmp (suffix, "exe") == 0
 300                           || _stricmp (suffix, "bat") == 0
 301                           || _stricmp (suffix, "cmd") == 0
 302                           || _stricmp (suffix, "com") == 0)
 303                         mode |= S_IEXEC_UGO;
 304                     }
 305                 }
 306               else
 307                 /* Cannot determine file name.  Pretend that it is executable.  */
 308                 mode |= S_IEXEC_UGO;
 309             }
 310         }
 311       buf->st_mode = mode;
 312
 313       /* st_nlink can be determined through
 314          GetFileInformationByHandle
 315          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle>
 316          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information>
 317          or through
 318          GetFileInformationByHandleEx with argument FileStandardInfo
 319          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 320          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_standard_info>
 321          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 322       buf->st_nlink = (info.nNumberOfLinks > SHRT_MAX ? SHRT_MAX : info.nNumberOfLinks);
 323
 324       /* There's no easy way to map the Windows SID concept to an integer.  */
 325       buf->st_uid = 0;
 326       buf->st_gid = 0;
 327
 328       /* st_rdev is irrelevant for normal files and directories.  */
 329       buf->st_rdev = 0;
 330
 331       /* st_size can be determined through
 332          GetFileSizeEx
 333          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfilesizeex>
 334          or through
 335          GetFileAttributesEx
 336          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileattributesexa>
 337          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_win32_file_attribute_data>
 338          or through
 339          GetFileInformationByHandle
 340          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle>
 341          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information>
 342          or through
 343          GetFileInformationByHandleEx with argument FileStandardInfo
 344          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 345          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_standard_info>
 346          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 347       if (sizeof (buf->st_size) <= 4)
 348         /* Range check already done above.  */
 349         buf->st_size = info.nFileSizeLow;
 350       else
 351         buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow;
 352
 353       /* st_atime, st_mtime, st_ctime can be determined through
 354          GetFileTime
 355          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfiletime>
 356          or through
 357          GetFileAttributesEx
 358          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileattributesexa>
 359          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_win32_file_attribute_data>
 360          or through
 361          GetFileInformationByHandle
 362          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-getfileinformationbyhandle>
 363          <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/ns-fileapi-_by_handle_file_information>
 364          or through
 365          GetFileInformationByHandleEx with argument FileBasicInfo
 366          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-getfileinformationbyhandleex>
 367          <https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_basic_info>
 368          The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
 369 #if _GL_WINDOWS_STAT_TIMESPEC
 370       buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime);
 371       buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime);
 372       buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime);
 373 #else
 374       buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime);
 375       buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime);
 376       buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime);
 377 #endif
 378
 379       return 0;
 380     }
 381   else if (type == FILE_TYPE_CHAR || type == FILE_TYPE_PIPE)
 382     {
 383       buf->st_dev = 0;
 384 #if _GL_WINDOWS_STAT_INODES == 2
 385       buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0;
 386 #else
 387       buf->st_ino = 0;
 388 #endif
 389       buf->st_mode = (type == FILE_TYPE_PIPE ? _S_IFIFO : _S_IFCHR);
 390       buf->st_nlink = 1;
 391       buf->st_uid = 0;
 392       buf->st_gid = 0;
 393       buf->st_rdev = 0;
 394       if (type == FILE_TYPE_PIPE)
 395         {
 396           /* PeekNamedPipe
 397              <https://msdn.microsoft.com/en-us/library/aa365779.aspx> */
 398           DWORD bytes_available;
 399           if (PeekNamedPipe (h, NULL, 0, NULL, &bytes_available, NULL))
 400             buf->st_size = bytes_available;
 401           else
 402             buf->st_size = 0;
 403         }
 404       else
 405         buf->st_size = 0;
 406 #if _GL_WINDOWS_STAT_TIMESPEC
 407       buf->st_atim.tv_sec = 0; buf->st_atim.tv_nsec = 0;
 408       buf->st_mtim.tv_sec = 0; buf->st_mtim.tv_nsec = 0;
 409       buf->st_ctim.tv_sec = 0; buf->st_ctim.tv_nsec = 0;
 410 #else
 411       buf->st_atime = 0;
 412       buf->st_mtime = 0;
 413       buf->st_ctime = 0;
 414 #endif
 415       return 0;
 416     }
 417   else
 418     {
 419       errno = ENOENT;
 420       return -1;
 421     }
 422
 423  failed:
 424   {
 425     DWORD error = GetLastError ();
 426     #if 0
 427     fprintf (stderr, "_gl_fstat_by_handle error 0x%x\n", (unsigned int) error);
 428     #endif
 429     switch (error)
 430       {
 431       case ERROR_ACCESS_DENIED:
 432       case ERROR_SHARING_VIOLATION:
 433         errno = EACCES;
 434         break;
 435
 436       case ERROR_OUTOFMEMORY:
 437         errno = ENOMEM;
 438         break;
 439
 440       case ERROR_WRITE_FAULT:
 441       case ERROR_READ_FAULT:
 442       case ERROR_GEN_FAILURE:
 443         errno = EIO;
 444         break;
 445
 446       default:
 447         errno = EINVAL;
 448         break;
 449       }
 450     return -1;
 451   }
 452 }
 453
 454 #else
 455
 456 /* This declaration is solely to ensure that after preprocessing
 457    this file is never empty.  */
 458 typedef int dummy;
 459
 460 #endif