stat.c@ 3613

Last change on this file since 3613 was 3613, checked in by bird, 7 months ago
src/sed: Merged in changes between 4.1.5 and 4.9 from the vendor branch. (svn merge ^{/vendor/sed/4.1.5}/vendor/sed/current .)
File size: 13.4 KB

Line
1	/* Work around platform bugs in stat.
2	Copyright (C) 2009-2022 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	}

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source: kBuild/trunk/src/sed/lib/stat.c@ 3613

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