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 */ |
865 | |