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1 | /* File tree walker functions. | |
2 | Copyright (C) 1996-2022 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <https://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #ifdef HAVE_CONFIG_H | |
20 | # include <config.h> | |
21 | #endif | |
22 | ||
23 | #if __GNUC__ | |
24 | # define alloca __builtin_alloca | |
25 | #else | |
26 | # if HAVE_ALLOCA_H | |
27 | # include <alloca.h> | |
28 | # else | |
29 | # ifdef _AIX | |
30 | # pragma alloca | |
31 | # else | |
32 | char *alloca (); | |
33 | # endif | |
34 | # endif | |
35 | #endif | |
36 | ||
37 | #ifdef _LIBC | |
38 | # include <dirent.h> | |
39 | # define NAMLEN(dirent) _D_EXACT_NAMLEN (dirent) | |
40 | #else | |
41 | # if HAVE_DIRENT_H | |
42 | # include <dirent.h> | |
43 | # define NAMLEN(dirent) strlen ((dirent)->d_name) | |
44 | # else | |
45 | # define dirent direct | |
46 | # define NAMLEN(dirent) (dirent)->d_namlen | |
47 | # if HAVE_SYS_NDIR_H | |
48 | # include <sys/ndir.h> | |
49 | # endif | |
50 | # if HAVE_SYS_DIR_H | |
51 | # include <sys/dir.h> | |
52 | # endif | |
53 | # if HAVE_NDIR_H | |
54 | # include <ndir.h> | |
55 | # endif | |
56 | # endif | |
57 | #endif | |
58 | ||
59 | #include <errno.h> | |
60 | #include <fcntl.h> | |
61 | #include <ftw.h> | |
62 | #include <limits.h> | |
63 | #include <search.h> | |
64 | #include <stdlib.h> | |
65 | #include <string.h> | |
66 | #include <unistd.h> | |
67 | #include <not-cancel.h> | |
68 | #include <sys/param.h> | |
69 | #ifdef _LIBC | |
70 | # include <include/sys/stat.h> | |
71 | #else | |
72 | # include <sys/stat.h> | |
73 | #endif | |
74 | ||
75 | #if ! _LIBC && !HAVE_DECL_STPCPY && !defined stpcpy | |
76 | char *stpcpy (); | |
77 | #endif | |
78 | ||
79 | #if ! _LIBC && ! defined HAVE_MEMPCPY && ! defined mempcpy | |
80 | /* Be CAREFUL that there are no side effects in N. */ | |
81 | # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N))) | |
82 | #endif | |
83 | ||
84 | /* #define NDEBUG 1 */ | |
85 | #include <assert.h> | |
86 | ||
87 | #ifndef _LIBC | |
88 | # undef __chdir | |
89 | # define __chdir chdir | |
90 | # undef __closedir | |
91 | # define __closedir closedir | |
92 | # undef __fchdir | |
93 | # define __fchdir fchdir | |
94 | # undef __getcwd | |
95 | # define __getcwd(P, N) xgetcwd () | |
96 | extern char *xgetcwd (void); | |
97 | # undef __mempcpy | |
98 | # define __mempcpy mempcpy | |
99 | # undef __opendir | |
100 | # define __opendir opendir | |
101 | # undef __readdir64 | |
102 | # define __readdir64 readdir | |
103 | # undef __stpcpy | |
104 | # define __stpcpy stpcpy | |
105 | # undef __tdestroy | |
106 | # define __tdestroy tdestroy | |
107 | # undef __tfind | |
108 | # define __tfind tfind | |
109 | # undef __tsearch | |
110 | # define __tsearch tsearch | |
111 | # undef dirent64 | |
112 | # define dirent64 dirent | |
113 | # undef MAX | |
114 | # define MAX(a, b) ((a) > (b) ? (a) : (b)) | |
115 | #endif | |
116 | ||
117 | /* Arrange to make lstat calls go through the wrapper function | |
118 | on systems with an lstat function that does not dereference symlinks | |
119 | that are specified with a trailing slash. */ | |
120 | #if ! _LIBC && ! LSTAT_FOLLOWS_SLASHED_SYMLINK | |
121 | int rpl_lstat (const char *, struct stat *); | |
122 | # undef lstat | |
123 | # define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf) | |
124 | #endif | |
125 | ||
126 | #ifndef __set_errno | |
127 | # define __set_errno(Val) errno = (Val) | |
128 | #endif | |
129 | ||
130 | /* Support for the LFS API version. */ | |
131 | #ifndef FTW_NAME | |
132 | # define FTW_NAME ftw | |
133 | # define NFTW_NAME nftw | |
134 | # define NFTW_OLD_NAME __old_nftw | |
135 | # define NFTW_NEW_NAME __new_nftw | |
136 | # define INO_T ino_t | |
137 | # define STRUCT_STAT stat | |
138 | # ifdef _LIBC | |
139 | # define LSTAT __lstat | |
140 | # define STAT __stat | |
141 | # define FSTATAT __fstatat | |
142 | # else | |
143 | # define LSTAT lstat | |
144 | # define XTAT stat | |
145 | # define FSTATAT fstatat | |
146 | # endif | |
147 | # define FTW_FUNC_T __ftw_func_t | |
148 | # define NFTW_FUNC_T __nftw_func_t | |
149 | #endif | |
150 | ||
151 | /* We define PATH_MAX if the system does not provide a definition. | |
152 | This does not artificially limit any operation. PATH_MAX is simply | |
153 | used as a guesstimate for the expected maximal path length. | |
154 | Buffers will be enlarged if necessary. */ | |
155 | #ifndef PATH_MAX | |
156 | # define PATH_MAX 1024 | |
157 | #endif | |
158 | ||
159 | struct dir_data | |
160 | { | |
161 | DIR *stream; | |
162 | int streamfd; | |
163 | char *content; | |
164 | }; | |
165 | ||
166 | struct known_object | |
167 | { | |
168 | dev_t dev; | |
169 | INO_T ino; | |
170 | }; | |
171 | ||
172 | struct ftw_data | |
173 | { | |
174 | /* Array with pointers to open directory streams. */ | |
175 | struct dir_data **dirstreams; | |
176 | size_t actdir; | |
177 | size_t maxdir; | |
178 | ||
179 | /* Buffer containing name of currently processed object. */ | |
180 | char *dirbuf; | |
181 | size_t dirbufsize; | |
182 | ||
183 | /* Passed as fourth argument to `nftw' callback. The `base' member | |
184 | tracks the content of the `dirbuf'. */ | |
185 | struct FTW ftw; | |
186 | ||
187 | /* Flags passed to `nftw' function. 0 for `ftw'. */ | |
188 | int flags; | |
189 | ||
190 | /* Conversion array for flag values. It is the identity mapping for | |
191 | `nftw' calls, otherwise it maps the values to those known by | |
192 | `ftw'. */ | |
193 | const int *cvt_arr; | |
194 | ||
195 | /* Callback function. We always use the `nftw' form. */ | |
196 | NFTW_FUNC_T func; | |
197 | ||
198 | /* Device of starting point. Needed for FTW_MOUNT. */ | |
199 | dev_t dev; | |
200 | ||
201 | /* Data structure for keeping fingerprints of already processed | |
202 | object. This is needed when not using FTW_PHYS. */ | |
203 | void *known_objects; | |
204 | }; | |
205 | ||
206 | static bool | |
207 | ftw_allocate (struct ftw_data *data, size_t newsize) | |
208 | { | |
209 | void *newp = realloc (data->dirstreams, data->maxdir | |
210 | * sizeof (struct dir_data *) | |
211 | + newsize); | |
212 | if (newp == NULL) | |
213 | return false; | |
214 | data->dirstreams = newp; | |
215 | data->dirbufsize = newsize; | |
216 | data->dirbuf = (char *) data->dirstreams | |
217 | + data->maxdir * sizeof (struct dir_data *); | |
218 | return true; | |
219 | } | |
220 | ||
221 | /* Internally we use the FTW_* constants used for `nftw'. When invoked | |
222 | as `ftw', map each flag to the subset of values used by `ftw'. */ | |
223 | static const int nftw_arr[] = | |
224 | { | |
225 | FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN | |
226 | }; | |
227 | ||
228 | static const int ftw_arr[] = | |
229 | { | |
230 | FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_F, FTW_D, FTW_NS | |
231 | }; | |
232 | ||
233 | ||
234 | /* Forward declarations of local functions. */ | |
235 | static int ftw_dir (struct ftw_data *data, struct STRUCT_STAT *st, | |
236 | struct dir_data *old_dir); | |
237 | ||
238 | ||
239 | static int | |
240 | object_compare (const void *p1, const void *p2) | |
241 | { | |
242 | /* We don't need a sophisticated and useful comparison. We are only | |
243 | interested in equality. However, we must be careful not to | |
244 | accidentally compare `holes' in the structure. */ | |
245 | const struct known_object *kp1 = p1, *kp2 = p2; | |
246 | int cmp1; | |
247 | cmp1 = (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino); | |
248 | if (cmp1 != 0) | |
249 | return cmp1; | |
250 | return (kp1->dev > kp2->dev) - (kp1->dev < kp2->dev); | |
251 | } | |
252 | ||
253 | ||
254 | static int | |
255 | add_object (struct ftw_data *data, struct STRUCT_STAT *st) | |
256 | { | |
257 | struct known_object *newp = malloc (sizeof (struct known_object)); | |
258 | if (newp == NULL) | |
259 | return -1; | |
260 | newp->dev = st->st_dev; | |
261 | newp->ino = st->st_ino; | |
262 | return __tsearch (newp, &data->known_objects, object_compare) ? 0 : -1; | |
263 | } | |
264 | ||
265 | ||
266 | static inline int | |
267 | find_object (struct ftw_data *data, struct STRUCT_STAT *st) | |
268 | { | |
269 | struct known_object obj; | |
270 | obj.dev = st->st_dev; | |
271 | obj.ino = st->st_ino; | |
272 | return __tfind (&obj, &data->known_objects, object_compare) != NULL; | |
273 | } | |
274 | ||
275 | ||
276 | static inline int | |
277 | __attribute ((always_inline)) | |
278 | open_dir_stream (int *dfdp, struct ftw_data *data, struct dir_data *dirp) | |
279 | { | |
280 | int result = 0; | |
281 | ||
282 | if (data->dirstreams[data->actdir] != NULL) | |
283 | { | |
284 | /* Oh, oh. We must close this stream. Get all remaining | |
285 | entries and store them as a list in the `content' member of | |
286 | the `struct dir_data' variable. */ | |
287 | size_t bufsize = 1024; | |
288 | char *buf = malloc (bufsize); | |
289 | ||
290 | if (buf == NULL) | |
291 | result = -1; | |
292 | else | |
293 | { | |
294 | DIR *st = data->dirstreams[data->actdir]->stream; | |
295 | struct dirent64 *d; | |
296 | size_t actsize = 0; | |
297 | ||
298 | while ((d = __readdir64 (st)) != NULL) | |
299 | { | |
300 | size_t this_len = NAMLEN (d); | |
301 | if (actsize + this_len + 2 >= bufsize) | |
302 | { | |
303 | char *newp; | |
304 | bufsize += MAX (1024, 2 * this_len); | |
305 | newp = (char *) realloc (buf, bufsize); | |
306 | if (newp == NULL) | |
307 | { | |
308 | /* No more memory. */ | |
309 | int save_err = errno; | |
310 | free (buf); | |
311 | __set_errno (save_err); | |
312 | return -1; | |
313 | } | |
314 | buf = newp; | |
315 | } | |
316 | ||
317 | *((char *) __mempcpy (buf + actsize, d->d_name, this_len)) | |
318 | = '\0'; | |
319 | actsize += this_len + 1; | |
320 | } | |
321 | ||
322 | /* Terminate the list with an additional NUL byte. */ | |
323 | buf[actsize++] = '\0'; | |
324 | ||
325 | /* Shrink the buffer to what we actually need. */ | |
326 | void *content = realloc (buf, actsize); | |
327 | data->dirstreams[data->actdir]->content = content; | |
328 | if (content == NULL) | |
329 | { | |
330 | int save_err = errno; | |
331 | free (buf); | |
332 | __set_errno (save_err); | |
333 | result = -1; | |
334 | } | |
335 | else | |
336 | { | |
337 | __closedir (st); | |
338 | data->dirstreams[data->actdir]->stream = NULL; | |
339 | data->dirstreams[data->actdir]->streamfd = -1; | |
340 | data->dirstreams[data->actdir] = NULL; | |
341 | } | |
342 | } | |
343 | } | |
344 | ||
345 | /* Open the new stream. */ | |
346 | if (result == 0) | |
347 | { | |
348 | assert (data->dirstreams[data->actdir] == NULL); | |
349 | ||
350 | if (dfdp != NULL && *dfdp != -1) | |
351 | { | |
352 | int fd = __openat64_nocancel (*dfdp, data->dirbuf + data->ftw.base, | |
353 | O_RDONLY | O_DIRECTORY | O_NDELAY); | |
354 | dirp->stream = NULL; | |
355 | if (fd != -1 && (dirp->stream = __fdopendir (fd)) == NULL) | |
356 | __close_nocancel_nostatus (fd); | |
357 | } | |
358 | else | |
359 | { | |
360 | const char *name; | |
361 | ||
362 | if (data->flags & FTW_CHDIR) | |
363 | { | |
364 | name = data->dirbuf + data->ftw.base; | |
365 | if (name[0] == '\0') | |
366 | name = "."; | |
367 | } | |
368 | else | |
369 | name = data->dirbuf; | |
370 | ||
371 | dirp->stream = __opendir (name); | |
372 | } | |
373 | ||
374 | if (dirp->stream == NULL) | |
375 | result = -1; | |
376 | else | |
377 | { | |
378 | dirp->streamfd = __dirfd (dirp->stream); | |
379 | dirp->content = NULL; | |
380 | data->dirstreams[data->actdir] = dirp; | |
381 | ||
382 | if (++data->actdir == data->maxdir) | |
383 | data->actdir = 0; | |
384 | } | |
385 | } | |
386 | ||
387 | return result; | |
388 | } | |
389 | ||
390 | ||
391 | static int | |
392 | process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, | |
393 | size_t namlen, int d_type) | |
394 | { | |
395 | struct STRUCT_STAT st; | |
396 | int result = 0; | |
397 | int flag = 0; | |
398 | size_t new_buflen; | |
399 | ||
400 | if (name[0] == '.' && (name[1] == '\0' | |
401 | || (name[1] == '.' && name[2] == '\0'))) | |
402 | /* Don't process the "." and ".." entries. */ | |
403 | return 0; | |
404 | ||
405 | new_buflen = data->ftw.base + namlen + 2; | |
406 | if (data->dirbufsize < new_buflen | |
407 | && !ftw_allocate (data, 2 * new_buflen)) | |
408 | return -1; | |
409 | ||
410 | *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; | |
411 | ||
412 | int statres; | |
413 | if (dir->streamfd != -1) | |
414 | statres = FSTATAT (dir->streamfd, name, &st, | |
415 | (data->flags & FTW_PHYS) ? AT_SYMLINK_NOFOLLOW : 0); | |
416 | else | |
417 | { | |
418 | if ((data->flags & FTW_CHDIR) == 0) | |
419 | name = data->dirbuf; | |
420 | ||
421 | statres = ((data->flags & FTW_PHYS) | |
422 | ? LSTAT (name, &st) | |
423 | : STAT (name, &st)); | |
424 | } | |
425 | ||
426 | if (statres < 0) | |
427 | { | |
428 | if (errno != EACCES && errno != ENOENT) | |
429 | result = -1; | |
430 | else if (data->flags & FTW_PHYS) | |
431 | flag = FTW_NS; | |
432 | else | |
433 | { | |
434 | /* Old code left ST undefined for dangling DT_LNK without | |
435 | FTW_PHYS set; a clarification at the POSIX level suggests | |
436 | it should contain information about the link (ala lstat). | |
437 | We do our best to fill in what data we can. */ | |
438 | if (dir->streamfd != -1) | |
439 | statres = FSTATAT (dir->streamfd, name, &st, | |
440 | AT_SYMLINK_NOFOLLOW); | |
441 | else | |
442 | statres = LSTAT (name, &st); | |
443 | if (statres == 0 && S_ISLNK (st.st_mode)) | |
444 | flag = FTW_SLN; | |
445 | else | |
446 | flag = FTW_NS; | |
447 | } | |
448 | } | |
449 | else | |
450 | { | |
451 | if (S_ISDIR (st.st_mode)) | |
452 | flag = FTW_D; | |
453 | else if (S_ISLNK (st.st_mode)) | |
454 | flag = FTW_SL; | |
455 | else | |
456 | flag = FTW_F; | |
457 | } | |
458 | ||
459 | if (result == 0 | |
460 | && (flag == FTW_NS | |
461 | || !(data->flags & FTW_MOUNT) || st.st_dev == data->dev)) | |
462 | { | |
463 | if (flag == FTW_D) | |
464 | { | |
465 | if ((data->flags & FTW_PHYS) | |
466 | || (!find_object (data, &st) | |
467 | /* Remember the object. */ | |
468 | && (result = add_object (data, &st)) == 0)) | |
469 | result = ftw_dir (data, &st, dir); | |
470 | } | |
471 | else | |
472 | result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag], | |
473 | &data->ftw); | |
474 | } | |
475 | ||
476 | if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SUBTREE) | |
477 | result = 0; | |
478 | ||
479 | return result; | |
480 | } | |
481 | ||
482 | ||
483 | static int | |
484 | __attribute ((noinline)) | |
485 | ftw_dir (struct ftw_data *data, struct STRUCT_STAT *st, struct dir_data *old_dir) | |
486 | { | |
487 | struct dir_data dir; | |
488 | struct dirent64 *d; | |
489 | int previous_base = data->ftw.base; | |
490 | int result; | |
491 | char *startp; | |
492 | ||
493 | /* Open the stream for this directory. This might require that | |
494 | another stream has to be closed. */ | |
495 | result = open_dir_stream (old_dir == NULL ? NULL : &old_dir->streamfd, | |
496 | data, &dir); | |
497 | if (result != 0) | |
498 | { | |
499 | if (errno == EACCES) | |
500 | /* We cannot read the directory. Signal this with a special flag. */ | |
501 | result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw); | |
502 | ||
503 | return result; | |
504 | } | |
505 | ||
506 | /* First, report the directory (if not depth-first). */ | |
507 | if (!(data->flags & FTW_DEPTH)) | |
508 | { | |
509 | result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw); | |
510 | if (result != 0) | |
511 | { | |
512 | int save_err; | |
513 | fail: | |
514 | save_err = errno; | |
515 | __closedir (dir.stream); | |
516 | dir.streamfd = -1; | |
517 | __set_errno (save_err); | |
518 | ||
519 | if (data->actdir-- == 0) | |
520 | data->actdir = data->maxdir - 1; | |
521 | data->dirstreams[data->actdir] = NULL; | |
522 | return result; | |
523 | } | |
524 | } | |
525 | ||
526 | /* If necessary, change to this directory. */ | |
527 | if (data->flags & FTW_CHDIR) | |
528 | { | |
529 | if (__fchdir (__dirfd (dir.stream)) < 0) | |
530 | { | |
531 | result = -1; | |
532 | goto fail; | |
533 | } | |
534 | } | |
535 | ||
536 | /* Next, update the `struct FTW' information. */ | |
537 | ++data->ftw.level; | |
538 | startp = __rawmemchr (data->dirbuf, '\0'); | |
539 | /* There always must be a directory name. */ | |
540 | assert (startp != data->dirbuf); | |
541 | if (startp[-1] != '/') | |
542 | *startp++ = '/'; | |
543 | data->ftw.base = startp - data->dirbuf; | |
544 | ||
545 | while (dir.stream != NULL && (d = __readdir64 (dir.stream)) != NULL) | |
546 | { | |
547 | int d_type = DT_UNKNOWN; | |
548 | #ifdef _DIRENT_HAVE_D_TYPE | |
549 | d_type = d->d_type; | |
550 | #endif | |
551 | result = process_entry (data, &dir, d->d_name, NAMLEN (d), d_type); | |
552 | if (result != 0) | |
553 | break; | |
554 | } | |
555 | ||
556 | if (dir.stream != NULL) | |
557 | { | |
558 | /* The stream is still open. I.e., we did not need more | |
559 | descriptors. Simply close the stream now. */ | |
560 | int save_err = errno; | |
561 | ||
562 | assert (dir.content == NULL); | |
563 | ||
564 | __closedir (dir.stream); | |
565 | dir.streamfd = -1; | |
566 | __set_errno (save_err); | |
567 | ||
568 | if (data->actdir-- == 0) | |
569 | data->actdir = data->maxdir - 1; | |
570 | data->dirstreams[data->actdir] = NULL; | |
571 | } | |
572 | else | |
573 | { | |
574 | int save_err; | |
575 | char *runp = dir.content; | |
576 | ||
577 | while (result == 0 && *runp != '\0') | |
578 | { | |
579 | char *endp = strchr (runp, '\0'); | |
580 | ||
581 | // XXX Should store the d_type values as well?! | |
582 | result = process_entry (data, &dir, runp, endp - runp, DT_UNKNOWN); | |
583 | ||
584 | runp = endp + 1; | |
585 | } | |
586 | ||
587 | save_err = errno; | |
588 | free (dir.content); | |
589 | __set_errno (save_err); | |
590 | } | |
591 | ||
592 | if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SIBLINGS) | |
593 | result = 0; | |
594 | ||
595 | /* Prepare the return, revert the `struct FTW' information. */ | |
596 | data->dirbuf[data->ftw.base - 1] = '\0'; | |
597 | --data->ftw.level; | |
598 | data->ftw.base = previous_base; | |
599 | ||
600 | /* Finally, if we process depth-first report the directory. */ | |
601 | if (result == 0 && (data->flags & FTW_DEPTH)) | |
602 | result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw); | |
603 | ||
604 | if (old_dir | |
605 | && (data->flags & FTW_CHDIR) | |
606 | && (result == 0 | |
607 | || ((data->flags & FTW_ACTIONRETVAL) | |
608 | && (result != -1 && result != FTW_STOP)))) | |
609 | { | |
610 | /* Change back to the parent directory. */ | |
611 | int done = 0; | |
612 | if (old_dir->stream != NULL) | |
613 | if (__fchdir (__dirfd (old_dir->stream)) == 0) | |
614 | done = 1; | |
615 | ||
616 | if (!done) | |
617 | { | |
618 | if (data->ftw.base == 1) | |
619 | { | |
620 | if (__chdir ("/") < 0) | |
621 | result = -1; | |
622 | } | |
623 | else | |
624 | if (__chdir ("..") < 0) | |
625 | result = -1; | |
626 | } | |
627 | } | |
628 | ||
629 | return result; | |
630 | } | |
631 | ||
632 | ||
633 | static int | |
634 | __attribute ((noinline)) | |
635 | ftw_startup (const char *dir, int is_nftw, void *func, int descriptors, | |
636 | int flags) | |
637 | { | |
638 | struct ftw_data data = { .dirstreams = NULL }; | |
639 | struct STRUCT_STAT st; | |
640 | int result = 0; | |
641 | int save_err; | |
642 | int cwdfd = -1; | |
643 | char *cwd = NULL; | |
644 | char *cp; | |
645 | ||
646 | /* First make sure the parameters are reasonable. */ | |
647 | if (dir[0] == '\0') | |
648 | { | |
649 | __set_errno (ENOENT); | |
650 | return -1; | |
651 | } | |
652 | ||
653 | data.maxdir = descriptors < 1 ? 1 : descriptors; | |
654 | data.actdir = 0; | |
655 | /* PATH_MAX is always defined when we get here. */ | |
656 | if (!ftw_allocate (&data, MAX (2 * strlen (dir), PATH_MAX))) | |
657 | return -1; | |
658 | memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *)); | |
659 | cp = __stpcpy (data.dirbuf, dir); | |
660 | /* Strip trailing slashes. */ | |
661 | while (cp > data.dirbuf + 1 && cp[-1] == '/') | |
662 | --cp; | |
663 | *cp = '\0'; | |
664 | ||
665 | data.ftw.level = 0; | |
666 | ||
667 | /* Find basename. */ | |
668 | while (cp > data.dirbuf && cp[-1] != '/') | |
669 | --cp; | |
670 | data.ftw.base = cp - data.dirbuf; | |
671 | ||
672 | data.flags = flags; | |
673 | ||
674 | /* This assignment might seem to be strange but it is what we want. | |
675 | The trick is that the first three arguments to the `ftw' and | |
676 | `nftw' callback functions are equal. Therefore we can call in | |
677 | every case the callback using the format of the `nftw' version | |
678 | and get the correct result since the stack layout for a function | |
679 | call in C allows this. */ | |
680 | data.func = (NFTW_FUNC_T) func; | |
681 | ||
682 | /* Since we internally use the complete set of FTW_* values we need | |
683 | to reduce the value range before calling a `ftw' callback. */ | |
684 | data.cvt_arr = is_nftw ? nftw_arr : ftw_arr; | |
685 | ||
686 | /* No object known so far. */ | |
687 | data.known_objects = NULL; | |
688 | ||
689 | /* Now go to the directory containing the initial file/directory. */ | |
690 | if (flags & FTW_CHDIR) | |
691 | { | |
692 | /* We have to be able to go back to the current working | |
693 | directory. The best way to do this is to use a file | |
694 | descriptor. */ | |
695 | cwdfd = __open (".", O_RDONLY | O_DIRECTORY); | |
696 | if (cwdfd == -1) | |
697 | { | |
698 | /* Try getting the directory name. This can be needed if | |
699 | the current directory is executable but not readable. */ | |
700 | if (errno == EACCES) | |
701 | /* GNU extension ahead. */ | |
702 | cwd = __getcwd (NULL, 0); | |
703 | ||
704 | if (cwd == NULL) | |
705 | goto out_fail; | |
706 | } | |
707 | else if (data.maxdir > 1) | |
708 | /* Account for the file descriptor we use here. */ | |
709 | --data.maxdir; | |
710 | ||
711 | if (data.ftw.base > 0) | |
712 | { | |
713 | /* Change to the directory the file is in. In data.dirbuf | |
714 | we have a writable copy of the file name. Just NUL | |
715 | terminate it for now and change the directory. */ | |
716 | if (data.ftw.base == 1) | |
717 | /* I.e., the file is in the root directory. */ | |
718 | result = __chdir ("/"); | |
719 | else | |
720 | { | |
721 | char ch = data.dirbuf[data.ftw.base - 1]; | |
722 | data.dirbuf[data.ftw.base - 1] = '\0'; | |
723 | result = __chdir (data.dirbuf); | |
724 | data.dirbuf[data.ftw.base - 1] = ch; | |
725 | } | |
726 | } | |
727 | } | |
728 | ||
729 | /* Get stat info for start directory. */ | |
730 | if (result == 0) | |
731 | { | |
732 | const char *name; | |
733 | ||
734 | if (data.flags & FTW_CHDIR) | |
735 | { | |
736 | name = data.dirbuf + data.ftw.base; | |
737 | if (name[0] == '\0') | |
738 | name = "."; | |
739 | } | |
740 | else | |
741 | name = data.dirbuf; | |
742 | ||
743 | if (((flags & FTW_PHYS) | |
744 | ? LSTAT (name, &st) | |
745 | : STAT (name, &st)) < 0) | |
746 | { | |
747 | if (!(flags & FTW_PHYS) | |
748 | && errno == ENOENT | |
749 | && LSTAT (name, &st) == 0 | |
750 | && S_ISLNK (st.st_mode)) | |
751 | result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN], | |
752 | &data.ftw); | |
753 | else | |
754 | /* No need to call the callback since we cannot say anything | |
755 | about the object. */ | |
756 | result = -1; | |
757 | } | |
758 | else | |
759 | { | |
760 | if (S_ISDIR (st.st_mode)) | |
761 | { | |
762 | /* Remember the device of the initial directory in case | |
763 | FTW_MOUNT is given. */ | |
764 | data.dev = st.st_dev; | |
765 | ||
766 | /* We know this directory now. */ | |
767 | if (!(flags & FTW_PHYS)) | |
768 | result = add_object (&data, &st); | |
769 | ||
770 | if (result == 0) | |
771 | result = ftw_dir (&data, &st, NULL); | |
772 | } | |
773 | else | |
774 | { | |
775 | int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F; | |
776 | ||
777 | result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag], | |
778 | &data.ftw); | |
779 | } | |
780 | } | |
781 | ||
782 | if ((flags & FTW_ACTIONRETVAL) | |
783 | && (result == FTW_SKIP_SUBTREE || result == FTW_SKIP_SIBLINGS)) | |
784 | result = 0; | |
785 | } | |
786 | ||
787 | /* Return to the start directory (if necessary). */ | |
788 | if (cwdfd != -1) | |
789 | { | |
790 | int save_err = errno; | |
791 | __fchdir (cwdfd); | |
792 | __close_nocancel_nostatus (cwdfd); | |
793 | __set_errno (save_err); | |
794 | } | |
795 | else if (cwd != NULL) | |
796 | { | |
797 | int save_err = errno; | |
798 | __chdir (cwd); | |
799 | free (cwd); | |
800 | __set_errno (save_err); | |
801 | } | |
802 | ||
803 | /* Free all memory. */ | |
804 | out_fail: | |
805 | save_err = errno; | |
806 | __tdestroy (data.known_objects, free); | |
807 | free (data.dirstreams); | |
808 | __set_errno (save_err); | |
809 | ||
810 | return result; | |
811 | } | |
812 | ||
813 | ||
814 | ||
815 | /* Entry points. */ | |
816 | ||
817 | int | |
818 | FTW_NAME (const char *path, FTW_FUNC_T func, int descriptors) | |
819 | { | |
820 | return ftw_startup (path, 0, func, descriptors, 0); | |
821 | } | |
822 | ||
823 | #ifndef NFTW_OLD_NAME | |
824 | int | |
825 | NFTW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
826 | { | |
827 | return ftw_startup (path, 1, func, descriptors, flags); | |
828 | } | |
829 | #else | |
830 | ||
831 | # include <shlib-compat.h> | |
832 | ||
833 | int NFTW_NEW_NAME (const char *, NFTW_FUNC_T, int, int); | |
834 | ||
835 | int | |
836 | NFTW_NEW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
837 | { | |
838 | if (flags | |
839 | & ~(FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH | FTW_ACTIONRETVAL)) | |
840 | { | |
841 | __set_errno (EINVAL); | |
842 | return -1; | |
843 | } | |
844 | return ftw_startup (path, 1, func, descriptors, flags); | |
845 | } | |
846 | versioned_symbol (libc, NFTW_NEW_NAME, NFTW_NAME, GLIBC_2_3_3); | |
847 | ||
848 | # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_3_3) | |
849 | ||
850 | /* Older nftw* version just ignored all unknown flags. */ | |
851 | ||
852 | int NFTW_OLD_NAME (const char *, NFTW_FUNC_T, int, int); | |
853 | ||
854 | int | |
855 | attribute_compat_text_section | |
856 | NFTW_OLD_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
857 | { | |
858 | flags &= (FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH); | |
859 | return ftw_startup (path, 1, func, descriptors, flags); | |
860 | } | |
861 | ||
862 | compat_symbol (libc, NFTW_OLD_NAME, NFTW_NAME, GLIBC_2_1); | |
863 | # endif | |
864 | #endif /* NFTW_OLD_NAME */ |