1 /* Work around platform bugs in stat.
2 Copyright (C) 2009-2023 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 Eric Blake and Bruno Haible. */
18
19 /* If the user's config.h happens to include <sys/stat.h>, let it include only
20 the system's <sys/stat.h> here, so that orig_stat doesn't recurse to
21 rpl_stat. */
22 #define __need_system_sys_stat_h
23 #include <config.h>
24
25 /* Get the original definition of stat. It might be defined as a macro. */
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #undef __need_system_sys_stat_h
29
30 #if defined _WIN32 && ! defined __CYGWIN__
31 # define WINDOWS_NATIVE
32 #endif
33
34 #if !defined WINDOWS_NATIVE
35
36 static int
37 orig_stat (const char *filename, struct stat *buf)
38 {
39 return stat (filename, buf);
40 }
41
42 #endif
43
44 /* Specification. */
45 #ifdef __osf__
46 /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
47 eliminates this include because of the preliminary #include <sys/stat.h>
48 above. */
49 # include "sys/stat.h"
50 #else
51 # include <sys/stat.h>
52 #endif
53
54 #include "stat-time.h"
55
56 #include <errno.h>
57 #include <limits.h>
58 #include <string.h>
59 #include "filename.h"
60 #include "malloca.h"
61
62 #ifdef WINDOWS_NATIVE
63 # define WIN32_LEAN_AND_MEAN
64 # include <windows.h>
65 # include "stat-w32.h"
66 /* Don't assume that UNICODE is not defined. */
67 # undef WIN32_FIND_DATA
68 # define WIN32_FIND_DATA WIN32_FIND_DATAA
69 # undef CreateFile
70 # define CreateFile CreateFileA
71 # undef FindFirstFile
72 # define FindFirstFile FindFirstFileA
73 #endif
74
75 #ifdef WINDOWS_NATIVE
76 /* Return TRUE if the given file name denotes an UNC root. */
77 static BOOL
78 is_unc_root (const char *rname)
79 {
80 /* Test whether it has the syntax '\\server\share'. */
81 if (ISSLASH (rname[0]) && ISSLASH (rname[1]))
82 {
83 /* It starts with two slashes. Find the next slash. */
84 const char *p = rname + 2;
85 const char *q = p;
86 while (*q != '\0' && !ISSLASH (*q))
87 q++;
88 if (q > p && *q != '\0')
89 {
90 /* Found the next slash at q. */
91 q++;
92 const char *r = q;
93 while (*r != '\0' && !ISSLASH (*r))
94 r++;
95 if (r > q && *r == '\0')
96 return TRUE;
97 }
98 }
99 return FALSE;
100 }
101 #endif
102
103 /* Store information about NAME into ST. Work around bugs with
104 trailing slashes. Mingw has other bugs (such as st_ino always
105 being 0 on success) which this wrapper does not work around. But
106 at least this implementation provides the ability to emulate fchdir
107 correctly. */
108
109 int
110 rpl_stat (char const *name, struct stat *buf)
111 {
112 #ifdef WINDOWS_NATIVE
113 /* Fill the fields ourselves, because the original stat function returns
114 values for st_atime, st_mtime, st_ctime that depend on the current time
115 zone. See
116 <https://lists.gnu.org/r/bug-gnulib/2017-04/msg00134.html> */
117 /* XXX Should we convert to wchar_t* and prepend '\\?\', in order to work
118 around length limitations
119 <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file> ? */
120
121 /* POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>
122 specifies: "More than two leading <slash> characters shall be treated as
123 a single <slash> character." */
124 if (ISSLASH (name[0]) && ISSLASH (name[1]) && ISSLASH (name[2]))
125 {
126 name += 2;
127 while (ISSLASH (name[1]))
128 name++;
129 }
130
131 size_t len = strlen (name);
132 size_t drive_prefix_len = (HAS_DEVICE (name) ? 2 : 0);
133
134 /* Remove trailing slashes (except the very first one, at position
135 drive_prefix_len), but remember their presence. */
136 size_t rlen;
137 bool check_dir = false;
138
139 rlen = len;
140 while (rlen > drive_prefix_len && ISSLASH (name[rlen-1]))
141 {
142 check_dir = true;
143 if (rlen == drive_prefix_len + 1)
144 break;
145 rlen--;
146 }
147
148 /* Handle '' and 'C:'. */
149 if (!check_dir && rlen == drive_prefix_len)
150 {
151 errno = ENOENT;
152 return -1;
153 }
154
155 /* Handle '\\'. */
156 if (rlen == 1 && ISSLASH (name[0]) && len >= 2)
157 {
158 errno = ENOENT;
159 return -1;
160 }
161
162 const char *rname;
163 char *malloca_rname;
164 if (rlen == len)
165 {
166 rname = name;
167 malloca_rname = NULL;
168 }
169 else
170 {
171 malloca_rname = malloca (rlen + 1);
172 if (malloca_rname == NULL)
173 {
174 errno = ENOMEM;
175 return -1;
176 }
177 memcpy (malloca_rname, name, rlen);
178 malloca_rname[rlen] = '\0';
179 rname = malloca_rname;
180 }
181
182 /* There are two ways to get at the requested information:
183 - by scanning the parent directory and examining the relevant
184 directory entry,
185 - by opening the file directly.
186 The first approach fails for root directories (e.g. 'C:\') and
187 UNC root directories (e.g. '\\server\share').
188 The second approach fails for some system files (e.g. 'C:\pagefile.sys'
189 and 'C:\hiberfil.sys'): ERROR_SHARING_VIOLATION.
190 The second approach gives more information (in particular, correct
191 st_dev, st_ino, st_nlink fields).
192 So we use the second approach and, as a fallback except for root and
193 UNC root directories, also the first approach. */
194 {
195 int ret;
196
197 {
198 /* Approach based on the file. */
199
200 /* Open a handle to the file.
201 CreateFile
202 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea>
203 <https://docs.microsoft.com/en-us/windows/desktop/FileIO/creating-and-opening-files> */
204 HANDLE h =
205 CreateFile (rname,
206 FILE_READ_ATTRIBUTES,
207 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
208 NULL,
209 OPEN_EXISTING,
210 /* FILE_FLAG_POSIX_SEMANTICS (treat file names that differ only
211 in case as different) makes sense only when applied to *all*
212 filesystem operations. */
213 FILE_FLAG_BACKUP_SEMANTICS /* | FILE_FLAG_POSIX_SEMANTICS */,
214 NULL);
215 if (h != INVALID_HANDLE_VALUE)
216 {
217 ret = _gl_fstat_by_handle (h, rname, buf);
218 CloseHandle (h);
219 goto done;
220 }
221 }
222
223 /* Test for root and UNC root directories. */
224 if ((rlen == drive_prefix_len + 1 && ISSLASH (rname[drive_prefix_len]))
225 || is_unc_root (rname))
226 goto failed;
227
228 /* Fallback. */
229 {
230 /* Approach based on the directory entry. */
231
232 if (strchr (rname, '?') != NULL || strchr (rname, '*') != NULL)
233 {
234 /* Other Windows API functions would fail with error
235 ERROR_INVALID_NAME. */
236 if (malloca_rname != NULL)
237 freea (malloca_rname);
238 errno = ENOENT;
239 return -1;
240 }
241
242 /* Get the details about the directory entry. This can be done through
243 FindFirstFile
244 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfilea>
245 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa>
246 or through
247 FindFirstFileEx with argument FindExInfoBasic
248 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfileexa>
249 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ne-minwinbase-findex_info_levels>
250 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> */
251 WIN32_FIND_DATA info;
252 HANDLE h = FindFirstFile (rname, &info);
253 if (h == INVALID_HANDLE_VALUE)
254 goto failed;
255
256 /* Test for error conditions before starting to fill *buf. */
257 if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0)
258 {
259 FindClose (h);
260 if (malloca_rname != NULL)
261 freea (malloca_rname);
262 errno = EOVERFLOW;
263 return -1;
264 }
265
266 # if _GL_WINDOWS_STAT_INODES
267 buf->st_dev = 0;
268 # if _GL_WINDOWS_STAT_INODES == 2
269 buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0;
270 # else /* _GL_WINDOWS_STAT_INODES == 1 */
271 buf->st_ino = 0;
272 # endif
273 # else
274 /* st_ino is not wide enough for identifying a file on a device.
275 Without st_ino, st_dev is pointless. */
276 buf->st_dev = 0;
277 buf->st_ino = 0;
278 # endif
279
280 /* st_mode. */
281 unsigned int mode =
282 /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ? */
283 ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG)
284 | S_IREAD_UGO
285 | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO);
286 if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
287 {
288 /* Determine whether the file is executable by looking at the file
289 name suffix. */
290 if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0)
291 {
292 const char *last_dot = NULL;
293 const char *p;
294 for (p = info.cFileName; *p != '\0'; p++)
295 if (*p == '.')
296 last_dot = p;
297 if (last_dot != NULL)
298 {
299 const char *suffix = last_dot + 1;
300 if (_stricmp (suffix, "exe") == 0
301 || _stricmp (suffix, "bat") == 0
302 || _stricmp (suffix, "cmd") == 0
303 || _stricmp (suffix, "com") == 0)
304 mode |= S_IEXEC_UGO;
305 }
306 }
307 }
308 buf->st_mode = mode;
309
310 /* st_nlink. Ignore hard links here. */
311 buf->st_nlink = 1;
312
313 /* There's no easy way to map the Windows SID concept to an integer. */
314 buf->st_uid = 0;
315 buf->st_gid = 0;
316
317 /* st_rdev is irrelevant for normal files and directories. */
318 buf->st_rdev = 0;
319
320 /* st_size. */
321 if (sizeof (buf->st_size) <= 4)
322 /* Range check already done above. */
323 buf->st_size = info.nFileSizeLow;
324 else
325 buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow;
326
327 /* st_atime, st_mtime, st_ctime. */
328 # if _GL_WINDOWS_STAT_TIMESPEC
329 buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime);
330 buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime);
331 buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime);
332 # else
333 buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime);
334 buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime);
335 buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime);
336 # endif
337
338 FindClose (h);
339
340 ret = 0;
341 }
342
343 done:
344 if (ret >= 0 && check_dir && !S_ISDIR (buf->st_mode))
345 {
346 errno = ENOTDIR;
347 ret = -1;
348 }
349 if (malloca_rname != NULL)
350 {
351 int saved_errno = errno;
352 freea (malloca_rname);
353 errno = saved_errno;
354 }
355 return ret;
356 }
357
358 failed:
359 {
360 DWORD error = GetLastError ();
361 #if 0
362 fprintf (stderr, "rpl_stat error 0x%x\n", (unsigned int) error);
363 #endif
364
365 if (malloca_rname != NULL)
366 freea (malloca_rname);
367
368 switch (error)
369 {
370 /* Some of these errors probably cannot happen with the specific flags
371 that we pass to CreateFile. But who knows... */
372 case ERROR_FILE_NOT_FOUND: /* The last component of rname does not exist. */
373 case ERROR_PATH_NOT_FOUND: /* Some directory component in rname does not exist. */
374 case ERROR_BAD_PATHNAME: /* rname is such as '\\server'. */
375 case ERROR_BAD_NET_NAME: /* rname is such as '\\server\nonexistentshare'. */
376 case ERROR_INVALID_NAME: /* rname contains wildcards, misplaced colon, etc. */
377 case ERROR_DIRECTORY:
378 errno = ENOENT;
379 break;
380
381 case ERROR_ACCESS_DENIED: /* rname is such as 'C:\System Volume Information\foo'. */
382 case ERROR_SHARING_VIOLATION: /* rname is such as 'C:\pagefile.sys' (second approach only). */
383 /* XXX map to EACCES or EPERM? */
384 errno = EACCES;
385 break;
386
387 case ERROR_OUTOFMEMORY:
388 errno = ENOMEM;
389 break;
390
391 case ERROR_WRITE_PROTECT:
392 errno = EROFS;
393 break;
394
395 case ERROR_WRITE_FAULT:
396 case ERROR_READ_FAULT:
397 case ERROR_GEN_FAILURE:
398 errno = EIO;
399 break;
400
401 case ERROR_BUFFER_OVERFLOW:
402 case ERROR_FILENAME_EXCED_RANGE:
403 errno = ENAMETOOLONG;
404 break;
405
406 case ERROR_DELETE_PENDING: /* XXX map to EACCES or EPERM? */
407 errno = EPERM;
408 break;
409
410 default:
411 errno = EINVAL;
412 break;
413 }
414
415 return -1;
416 }
417 #else
418 int result = orig_stat (name, buf);
419 if (result == 0)
420 {
421 # if REPLACE_FUNC_STAT_FILE
422 /* Solaris 9 mistakenly succeeds when given a non-directory with a
423 trailing slash. */
424 if (!S_ISDIR (buf->st_mode))
425 {
426 size_t len = strlen (name);
427 if (ISSLASH (name[len - 1]))
428 {
429 errno = ENOTDIR;
430 return -1;
431 }
432 }
433 # endif /* REPLACE_FUNC_STAT_FILE */
434 result = stat_time_normalize (result, buf);
435 }
436 return result;
437 #endif
438 }