fcstat.c revision ca08ab68 
1/*
2 * Copyright © 2000 Keith Packard
3 * Copyright © 2005 Patrick Lam
4 *
5 * Permission to use, copy, modify, distribute, and sell this software and its
6 * documentation for any purpose is hereby granted without fee, provided that
7 * the above copyright notice appear in all copies and that both that
8 * copyright notice and this permission notice appear in supporting
9 * documentation, and that the name of the author(s) not be used in
10 * advertising or publicity pertaining to distribution of the software without
11 * specific, written prior permission.  The authors make no
12 * representations about the suitability of this software for any purpose.  It
13 * is provided "as is" without express or implied warranty.
14 *
15 * THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
16 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
17 * EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
18 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
19 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
20 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
21 * PERFORMANCE OF THIS SOFTWARE.
22 */
23#ifdef HAVE_CONFIG_H
24#include "config.h"
25#endif
26#include "fcint.h"
27#include "fcarch.h"
28#include <dirent.h>
29#include <limits.h>
30#include <sys/types.h>
31#include <sys/stat.h>
32#include <fcntl.h>
33#ifdef HAVE_SYS_VFS_H
34#include <sys/vfs.h>
35#endif
36#ifdef HAVE_SYS_STATFS_H
37#include <sys/statfs.h>
38#endif
39#ifdef HAVE_SYS_PARAM_H
40#include <sys/param.h>
41#endif
42#ifdef HAVE_SYS_MOUNT_H
43#include <sys/mount.h>
44#endif
45
46#ifdef _WIN32
47
48#include <windows.h>
49
50#ifdef __GNUC__
51typedef long long INT64;
52#define EPOCH_OFFSET 11644473600ll
53#else
54#define EPOCH_OFFSET 11644473600i64
55typedef __int64 INT64;
56#endif
57
58/* Workaround for problems in the stat() in the Microsoft C library:
59 *
60 * 1) stat() uses FindFirstFile() to get the file
61 * attributes. Unfortunately this API doesn't return correct values
62 * for modification time of a directory until some time after a file
63 * or subdirectory has been added to the directory. (This causes
64 * run-test.sh to fail, for instance.) GetFileAttributesEx() is
65 * better, it returns the updated timestamp right away.
66 *
67 * 2) stat() does some strange things related to backward
68 * compatibility with the local time timestamps on FAT volumes and
69 * daylight saving time. This causes problems after the switches
70 * to/from daylight saving time. See
71 * http://bugzilla.gnome.org/show_bug.cgi?id=154968 , especially
72 * comment #30, and http://www.codeproject.com/datetime/dstbugs.asp .
73 * We don't need any of that, FAT and Win9x are as good as dead. So
74 * just use the UTC timestamps from NTFS, converted to the Unix epoch.
75 */
76
77int
78FcStat (const FcChar8 *file, struct stat *statb)
79{
80    WIN32_FILE_ATTRIBUTE_DATA wfad;
81    char full_path_name[MAX_PATH];
82    char *basename;
83    DWORD rc;
84
85    if (!GetFileAttributesEx ((LPCSTR) file, GetFileExInfoStandard, &wfad))
86	return -1;
87
88    statb->st_dev = 0;
89
90    /* Calculate a pseudo inode number as a hash of the full path name.
91     * Call GetLongPathName() to get the spelling of the path name as it
92     * is on disk.
93     */
94    rc = GetFullPathName ((LPCSTR) file, sizeof (full_path_name), full_path_name, &basename);
95    if (rc == 0 || rc > sizeof (full_path_name))
96	return -1;
97
98    rc = GetLongPathName (full_path_name, full_path_name, sizeof (full_path_name));
99    statb->st_ino = FcStringHash ((const FcChar8 *) full_path_name);
100
101    statb->st_mode = _S_IREAD | _S_IWRITE;
102    statb->st_mode |= (statb->st_mode >> 3) | (statb->st_mode >> 6);
103
104    if (wfad.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
105	statb->st_mode |= _S_IFDIR;
106    else
107	statb->st_mode |= _S_IFREG;
108
109    statb->st_nlink = 1;
110    statb->st_uid = statb->st_gid = 0;
111    statb->st_rdev = 0;
112
113    if (wfad.nFileSizeHigh > 0)
114	return -1;
115    statb->st_size = wfad.nFileSizeLow;
116
117    statb->st_atime = (*(INT64 *)&wfad.ftLastAccessTime)/10000000 - EPOCH_OFFSET;
118    statb->st_mtime = (*(INT64 *)&wfad.ftLastWriteTime)/10000000 - EPOCH_OFFSET;
119    statb->st_ctime = statb->st_mtime;
120
121    return 0;
122}
123
124#else
125
126int
127FcStat (const FcChar8 *file, struct stat *statb)
128{
129  return stat ((char *) file, statb);
130}
131
132/* Adler-32 checksum implementation */
133struct Adler32 {
134    int a;
135    int b;
136};
137
138static void
139Adler32Init (struct Adler32 *ctx)
140{
141    ctx->a = 1;
142    ctx->b = 0;
143}
144
145static void
146Adler32Update (struct Adler32 *ctx, const char *data, int data_len)
147{
148    while (data_len--)
149    {
150	ctx->a = (ctx->a + *data++) % 65521;
151	ctx->b = (ctx->b + ctx->a) % 65521;
152    }
153}
154
155static int
156Adler32Finish (struct Adler32 *ctx)
157{
158    return ctx->a + (ctx->b << 16);
159}
160
161#ifdef HAVE_STRUCT_DIRENT_D_TYPE
162/* dirent.d_type can be relied upon on FAT filesystem */
163static FcBool
164FcDirChecksumScandirFilter(const struct dirent *entry)
165{
166    return entry->d_type != DT_DIR;
167}
168#endif
169
170static int
171FcDirChecksumScandirSorter(const struct dirent **lhs, const struct dirent **rhs)
172{
173    return strcmp((*lhs)->d_name, (*rhs)->d_name);
174}
175
176static int
177FcDirChecksum (const FcChar8 *dir, time_t *checksum)
178{
179    struct Adler32 ctx;
180    struct dirent **files;
181    int n, ret = 0;
182#ifndef HAVE_STRUCT_DIRENT_D_TYPE
183    size_t len = strlen ((const char *)dir);
184#endif
185
186    Adler32Init (&ctx);
187
188    n = scandir ((const char *)dir, &files,
189#ifdef HAVE_STRUCT_DIRENT_D_TYPE
190		 &FcDirChecksumScandirFilter,
191#else
192		 NULL,
193#endif
194		 &FcDirChecksumScandirSorter);
195    if (n == -1)
196	return -1;
197
198    while (n--)
199    {
200	size_t dlen = strlen (files[n]->d_name);
201	int dtype;
202
203#ifdef HAVE_STRUCT_DIRENT_D_TYPE
204	dtype = files[n]->d_type;
205#else
206	struct stat statb;
207	char f[PATH_MAX + 1];
208
209	memcpy (f, dir, len);
210	f[len] = FC_DIR_SEPARATOR;
211	memcpy (&f[len + 1], files[n]->d_name, dlen);
212	f[len + 1 + dlen] = 0;
213	if (lstat (f, &statb) < 0)
214	{
215	    ret = -1;
216	    goto bail;
217	}
218	if (S_ISDIR (statb.st_mode))
219	    goto bail;
220
221	dtype = statb.st_mode;
222#endif
223	Adler32Update (&ctx, files[n]->d_name, dlen + 1);
224	Adler32Update (&ctx, (char *)&dtype, sizeof (int));
225
226#ifndef HAVE_STRUCT_DIRENT_D_TYPE
227      bail:
228#endif
229	free (files[n]);
230    }
231    free (files);
232    if (ret == -1)
233	return -1;
234
235    *checksum = Adler32Finish (&ctx);
236
237    return 0;
238}
239#endif /* _WIN32 */
240
241int
242FcStatChecksum (const FcChar8 *file, struct stat *statb)
243{
244    if (FcStat (file, statb) == -1)
245        return -1;
246
247#ifndef _WIN32
248    /* We have a workaround of the broken stat() in FcStat() for Win32.
249     * No need to do something further more.
250     */
251    if (FcIsFsMtimeBroken (file))
252    {
253        if (FcDirChecksum (file, &statb->st_mtime) == -1)
254            return -1;
255    }
256#endif
257
258    return 0;
259}
260
261static int
262FcFStatFs (int fd, FcStatFS *statb)
263{
264    const char *p = NULL;
265    int ret = -1;
266    FcBool flag = FcFalse;
267
268    memset (statb, 0, sizeof (FcStatFS));
269
270#if defined(HAVE_FSTATVFS) && (defined(HAVE_STRUCT_STATVFS_F_BASETYPE) || defined(HAVE_STRUCT_STATVFS_F_FSTYPENAME))
271    struct statvfs buf;
272
273    if ((ret = fstatvfs (fd, &buf)) == 0)
274    {
275#  if defined(HAVE_STRUCT_STATVFS_F_BASETYPE)
276	p = buf.f_basetype;
277#  elif defined(HAVE_STRUCT_STATVFS_F_FSTYPENAME)
278	p = buf.f_fstypename;
279#  endif
280    }
281#elif defined(HAVE_FSTATFS) && (defined(HAVE_STRUCT_STATFS_F_FLAGS) || defined(HAVE_STRUCT_STATFS_F_FSTYPENAME) || defined(__linux__))
282    struct statfs buf;
283
284    if ((ret = fstatfs (fd, &buf)) == 0)
285    {
286#  if defined(HAVE_STRUCT_STATFS_F_FLAGS) && defined(MNT_LOCAL)
287	statb->is_remote_fs = !(buf.f_flags & MNT_LOCAL);
288	flag = FcTrue;
289#  endif
290#  if defined(HAVE_STRUCT_STATFS_F_FSTYPENAME)
291	p = buf.f_fstypename;
292#  elif defined(__linux__)
293	switch (buf.f_type)
294	{
295	case 0x6969: /* nfs */
296	    statb->is_remote_fs = FcTrue;
297	    break;
298	case 0x4d44: /* fat */
299	    statb->is_mtime_broken = FcTrue;
300	    break;
301	default:
302	    break;
303	}
304
305	return ret;
306#  else
307#    error "BUG: No way to figure out with fstatfs()"
308#  endif
309    }
310#endif
311    if (p)
312    {
313	if (!flag && strcmp (p, "nfs") == 0)
314	    statb->is_remote_fs = FcTrue;
315	if (strcmp (p, "msdosfs") == 0 ||
316	    strcmp (p, "pcfs") == 0)
317	    statb->is_mtime_broken = FcTrue;
318    }
319
320    return ret;
321}
322
323FcBool
324FcIsFsMmapSafe (int fd)
325{
326    FcStatFS statb;
327
328    if (FcFStatFs (fd, &statb) < 0)
329	return FcTrue;
330
331    return !statb.is_remote_fs;
332}
333
334FcBool
335FcIsFsMtimeBroken (const FcChar8 *dir)
336{
337    int fd = open ((const char *) dir, O_RDONLY);
338
339    if (fd != -1)
340    {
341	FcStatFS statb;
342	int ret = FcFStatFs (fd, &statb);
343
344	close (fd);
345	if (ret < 0)
346	    return FcFalse;
347
348	return statb.is_mtime_broken;
349    }
350
351    return FcFalse;
352}
353