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1 | /* File tree walker functions. | |
2 | Copyright (C) 1996-2019 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
17 | License along with the GNU C Library; if not, see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #ifdef HAVE_CONFIG_H | |
21 | # include <config.h> | |
22 | #endif | |
23 | ||
24 | #if __GNUC__ | |
25 | # define alloca __builtin_alloca | |
26 | #else | |
27 | # if HAVE_ALLOCA_H | |
28 | # include <alloca.h> | |
29 | # else | |
30 | # ifdef _AIX | |
31 | # pragma alloca | |
32 | # else | |
33 | char *alloca (); | |
34 | # endif | |
35 | # endif | |
36 | #endif | |
37 | ||
38 | #ifdef _LIBC | |
39 | # include <dirent.h> | |
40 | # define NAMLEN(dirent) _D_EXACT_NAMLEN (dirent) | |
41 | #else | |
42 | # if HAVE_DIRENT_H | |
43 | # include <dirent.h> | |
44 | # define NAMLEN(dirent) strlen ((dirent)->d_name) | |
45 | # else | |
46 | # define dirent direct | |
47 | # define NAMLEN(dirent) (dirent)->d_namlen | |
48 | # if HAVE_SYS_NDIR_H | |
49 | # include <sys/ndir.h> | |
50 | # endif | |
51 | # if HAVE_SYS_DIR_H | |
52 | # include <sys/dir.h> | |
53 | # endif | |
54 | # if HAVE_NDIR_H | |
55 | # include <ndir.h> | |
56 | # endif | |
57 | # endif | |
58 | #endif | |
59 | ||
60 | #include <errno.h> | |
61 | #include <fcntl.h> | |
62 | #include <ftw.h> | |
63 | #include <limits.h> | |
64 | #include <search.h> | |
65 | #include <stdlib.h> | |
66 | #include <string.h> | |
67 | #include <unistd.h> | |
68 | #include <not-cancel.h> | |
69 | #include <sys/param.h> | |
70 | #ifdef _LIBC | |
71 | # include <include/sys/stat.h> | |
72 | #else | |
73 | # include <sys/stat.h> | |
74 | #endif | |
75 | ||
76 | #if ! _LIBC && !HAVE_DECL_STPCPY && !defined stpcpy | |
77 | char *stpcpy (); | |
78 | #endif | |
79 | ||
80 | #if ! _LIBC && ! defined HAVE_MEMPCPY && ! defined mempcpy | |
81 | /* Be CAREFUL that there are no side effects in N. */ | |
82 | # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N))) | |
83 | #endif | |
84 | ||
85 | /* #define NDEBUG 1 */ | |
86 | #include <assert.h> | |
87 | ||
88 | #ifndef _LIBC | |
89 | # undef __chdir | |
90 | # define __chdir chdir | |
91 | # undef __closedir | |
92 | # define __closedir closedir | |
93 | # undef __fchdir | |
94 | # define __fchdir fchdir | |
95 | # undef __getcwd | |
96 | # define __getcwd(P, N) xgetcwd () | |
97 | extern char *xgetcwd (void); | |
98 | # undef __mempcpy | |
99 | # define __mempcpy mempcpy | |
100 | # undef __opendir | |
101 | # define __opendir opendir | |
102 | # undef __readdir64 | |
103 | # define __readdir64 readdir | |
104 | # undef __stpcpy | |
105 | # define __stpcpy stpcpy | |
106 | # undef __tdestroy | |
107 | # define __tdestroy tdestroy | |
108 | # undef __tfind | |
109 | # define __tfind tfind | |
110 | # undef __tsearch | |
111 | # define __tsearch tsearch | |
112 | # undef dirent64 | |
113 | # define dirent64 dirent | |
114 | # undef MAX | |
115 | # define MAX(a, b) ((a) > (b) ? (a) : (b)) | |
116 | #endif | |
117 | ||
118 | /* Arrange to make lstat calls go through the wrapper function | |
119 | on systems with an lstat function that does not dereference symlinks | |
120 | that are specified with a trailing slash. */ | |
121 | #if ! _LIBC && ! LSTAT_FOLLOWS_SLASHED_SYMLINK | |
122 | int rpl_lstat (const char *, struct stat *); | |
123 | # undef lstat | |
124 | # define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf) | |
125 | #endif | |
126 | ||
127 | #ifndef __set_errno | |
128 | # define __set_errno(Val) errno = (Val) | |
129 | #endif | |
130 | ||
131 | /* Support for the LFS API version. */ | |
132 | #ifndef FTW_NAME | |
133 | # define FTW_NAME ftw | |
134 | # define NFTW_NAME nftw | |
135 | # define NFTW_OLD_NAME __old_nftw | |
136 | # define NFTW_NEW_NAME __new_nftw | |
137 | # define INO_T ino_t | |
138 | # define STAT stat | |
139 | # ifdef _LIBC | |
140 | # define LXSTAT __lxstat | |
141 | # define XSTAT __xstat | |
142 | # define FXSTATAT __fxstatat | |
143 | # else | |
144 | # define LXSTAT(V,f,sb) lstat (f,sb) | |
145 | # define XSTAT(V,f,sb) stat (f,sb) | |
146 | # define FXSTATAT(V,d,f,sb,m) fstatat (d, f, sb, m) | |
147 | # endif | |
148 | # define FTW_FUNC_T __ftw_func_t | |
149 | # define NFTW_FUNC_T __nftw_func_t | |
150 | #endif | |
151 | ||
152 | /* We define PATH_MAX if the system does not provide a definition. | |
153 | This does not artificially limit any operation. PATH_MAX is simply | |
154 | used as a guesstimate for the expected maximal path length. | |
155 | Buffers will be enlarged if necessary. */ | |
156 | #ifndef PATH_MAX | |
157 | # define PATH_MAX 1024 | |
158 | #endif | |
159 | ||
160 | struct dir_data | |
161 | { | |
162 | DIR *stream; | |
163 | int streamfd; | |
164 | char *content; | |
165 | }; | |
166 | ||
167 | struct known_object | |
168 | { | |
169 | dev_t dev; | |
170 | INO_T ino; | |
171 | }; | |
172 | ||
173 | struct ftw_data | |
174 | { | |
175 | /* Array with pointers to open directory streams. */ | |
176 | struct dir_data **dirstreams; | |
177 | size_t actdir; | |
178 | size_t maxdir; | |
179 | ||
180 | /* Buffer containing name of currently processed object. */ | |
181 | char *dirbuf; | |
182 | size_t dirbufsize; | |
183 | ||
184 | /* Passed as fourth argument to `nftw' callback. The `base' member | |
185 | tracks the content of the `dirbuf'. */ | |
186 | struct FTW ftw; | |
187 | ||
188 | /* Flags passed to `nftw' function. 0 for `ftw'. */ | |
189 | int flags; | |
190 | ||
191 | /* Conversion array for flag values. It is the identity mapping for | |
192 | `nftw' calls, otherwise it maps the values to those known by | |
193 | `ftw'. */ | |
194 | const int *cvt_arr; | |
195 | ||
196 | /* Callback function. We always use the `nftw' form. */ | |
197 | NFTW_FUNC_T func; | |
198 | ||
199 | /* Device of starting point. Needed for FTW_MOUNT. */ | |
200 | dev_t dev; | |
201 | ||
202 | /* Data structure for keeping fingerprints of already processed | |
203 | object. This is needed when not using FTW_PHYS. */ | |
204 | void *known_objects; | |
205 | }; | |
206 | ||
207 | ||
208 | /* Internally we use the FTW_* constants used for `nftw'. When invoked | |
209 | as `ftw', map each flag to the subset of values used by `ftw'. */ | |
210 | static const int nftw_arr[] = | |
211 | { | |
212 | FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_SL, FTW_DP, FTW_SLN | |
213 | }; | |
214 | ||
215 | static const int ftw_arr[] = | |
216 | { | |
217 | FTW_F, FTW_D, FTW_DNR, FTW_NS, FTW_F, FTW_D, FTW_NS | |
218 | }; | |
219 | ||
220 | ||
221 | /* Forward declarations of local functions. */ | |
222 | static int ftw_dir (struct ftw_data *data, struct STAT *st, | |
223 | struct dir_data *old_dir); | |
224 | ||
225 | ||
226 | static int | |
227 | object_compare (const void *p1, const void *p2) | |
228 | { | |
229 | /* We don't need a sophisticated and useful comparison. We are only | |
230 | interested in equality. However, we must be careful not to | |
231 | accidentally compare `holes' in the structure. */ | |
232 | const struct known_object *kp1 = p1, *kp2 = p2; | |
233 | int cmp1; | |
234 | cmp1 = (kp1->ino > kp2->ino) - (kp1->ino < kp2->ino); | |
235 | if (cmp1 != 0) | |
236 | return cmp1; | |
237 | return (kp1->dev > kp2->dev) - (kp1->dev < kp2->dev); | |
238 | } | |
239 | ||
240 | ||
241 | static int | |
242 | add_object (struct ftw_data *data, struct STAT *st) | |
243 | { | |
244 | struct known_object *newp = malloc (sizeof (struct known_object)); | |
245 | if (newp == NULL) | |
246 | return -1; | |
247 | newp->dev = st->st_dev; | |
248 | newp->ino = st->st_ino; | |
249 | return __tsearch (newp, &data->known_objects, object_compare) ? 0 : -1; | |
250 | } | |
251 | ||
252 | ||
253 | static inline int | |
254 | find_object (struct ftw_data *data, struct STAT *st) | |
255 | { | |
256 | struct known_object obj; | |
257 | obj.dev = st->st_dev; | |
258 | obj.ino = st->st_ino; | |
259 | return __tfind (&obj, &data->known_objects, object_compare) != NULL; | |
260 | } | |
261 | ||
262 | ||
263 | static inline int | |
264 | __attribute ((always_inline)) | |
265 | open_dir_stream (int *dfdp, struct ftw_data *data, struct dir_data *dirp) | |
266 | { | |
267 | int result = 0; | |
268 | ||
269 | if (data->dirstreams[data->actdir] != NULL) | |
270 | { | |
271 | /* Oh, oh. We must close this stream. Get all remaining | |
272 | entries and store them as a list in the `content' member of | |
273 | the `struct dir_data' variable. */ | |
274 | size_t bufsize = 1024; | |
275 | char *buf = malloc (bufsize); | |
276 | ||
277 | if (buf == NULL) | |
278 | result = -1; | |
279 | else | |
280 | { | |
281 | DIR *st = data->dirstreams[data->actdir]->stream; | |
282 | struct dirent64 *d; | |
283 | size_t actsize = 0; | |
284 | ||
285 | while ((d = __readdir64 (st)) != NULL) | |
286 | { | |
287 | size_t this_len = NAMLEN (d); | |
288 | if (actsize + this_len + 2 >= bufsize) | |
289 | { | |
290 | char *newp; | |
291 | bufsize += MAX (1024, 2 * this_len); | |
292 | newp = (char *) realloc (buf, bufsize); | |
293 | if (newp == NULL) | |
294 | { | |
295 | /* No more memory. */ | |
296 | int save_err = errno; | |
297 | free (buf); | |
298 | __set_errno (save_err); | |
299 | return -1; | |
300 | } | |
301 | buf = newp; | |
302 | } | |
303 | ||
304 | *((char *) __mempcpy (buf + actsize, d->d_name, this_len)) | |
305 | = '\0'; | |
306 | actsize += this_len + 1; | |
307 | } | |
308 | ||
309 | /* Terminate the list with an additional NUL byte. */ | |
310 | buf[actsize++] = '\0'; | |
311 | ||
312 | /* Shrink the buffer to what we actually need. */ | |
313 | data->dirstreams[data->actdir]->content = realloc (buf, actsize); | |
314 | if (data->dirstreams[data->actdir]->content == NULL) | |
315 | { | |
316 | int save_err = errno; | |
317 | free (buf); | |
318 | __set_errno (save_err); | |
319 | result = -1; | |
320 | } | |
321 | else | |
322 | { | |
323 | __closedir (st); | |
324 | data->dirstreams[data->actdir]->stream = NULL; | |
325 | data->dirstreams[data->actdir]->streamfd = -1; | |
326 | data->dirstreams[data->actdir] = NULL; | |
327 | } | |
328 | } | |
329 | } | |
330 | ||
331 | /* Open the new stream. */ | |
332 | if (result == 0) | |
333 | { | |
334 | assert (data->dirstreams[data->actdir] == NULL); | |
335 | ||
336 | if (dfdp != NULL && *dfdp != -1) | |
337 | { | |
338 | int fd = __openat64_nocancel (*dfdp, data->dirbuf + data->ftw.base, | |
339 | O_RDONLY | O_DIRECTORY | O_NDELAY); | |
340 | dirp->stream = NULL; | |
341 | if (fd != -1 && (dirp->stream = __fdopendir (fd)) == NULL) | |
342 | __close_nocancel_nostatus (fd); | |
343 | } | |
344 | else | |
345 | { | |
346 | const char *name; | |
347 | ||
348 | if (data->flags & FTW_CHDIR) | |
349 | { | |
350 | name = data->dirbuf + data->ftw.base; | |
351 | if (name[0] == '\0') | |
352 | name = "."; | |
353 | } | |
354 | else | |
355 | name = data->dirbuf; | |
356 | ||
357 | dirp->stream = __opendir (name); | |
358 | } | |
359 | ||
360 | if (dirp->stream == NULL) | |
361 | result = -1; | |
362 | else | |
363 | { | |
364 | dirp->streamfd = __dirfd (dirp->stream); | |
365 | dirp->content = NULL; | |
366 | data->dirstreams[data->actdir] = dirp; | |
367 | ||
368 | if (++data->actdir == data->maxdir) | |
369 | data->actdir = 0; | |
370 | } | |
371 | } | |
372 | ||
373 | return result; | |
374 | } | |
375 | ||
376 | ||
377 | static int | |
378 | process_entry (struct ftw_data *data, struct dir_data *dir, const char *name, | |
379 | size_t namlen, int d_type) | |
380 | { | |
381 | struct STAT st; | |
382 | int result = 0; | |
383 | int flag = 0; | |
384 | size_t new_buflen; | |
385 | ||
386 | if (name[0] == '.' && (name[1] == '\0' | |
387 | || (name[1] == '.' && name[2] == '\0'))) | |
388 | /* Don't process the "." and ".." entries. */ | |
389 | return 0; | |
390 | ||
391 | new_buflen = data->ftw.base + namlen + 2; | |
392 | if (data->dirbufsize < new_buflen) | |
393 | { | |
394 | /* Enlarge the buffer. */ | |
395 | char *newp; | |
396 | ||
397 | data->dirbufsize = 2 * new_buflen; | |
398 | newp = (char *) realloc (data->dirbuf, data->dirbufsize); | |
399 | if (newp == NULL) | |
400 | return -1; | |
401 | data->dirbuf = newp; | |
402 | } | |
403 | ||
404 | *((char *) __mempcpy (data->dirbuf + data->ftw.base, name, namlen)) = '\0'; | |
405 | ||
406 | int statres; | |
407 | if (dir->streamfd != -1) | |
408 | statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st, | |
409 | (data->flags & FTW_PHYS) ? AT_SYMLINK_NOFOLLOW : 0); | |
410 | else | |
411 | { | |
412 | if ((data->flags & FTW_CHDIR) == 0) | |
413 | name = data->dirbuf; | |
414 | ||
415 | statres = ((data->flags & FTW_PHYS) | |
416 | ? LXSTAT (_STAT_VER, name, &st) | |
417 | : XSTAT (_STAT_VER, name, &st)); | |
418 | } | |
419 | ||
420 | if (statres < 0) | |
421 | { | |
422 | if (errno != EACCES && errno != ENOENT) | |
423 | result = -1; | |
424 | else if (data->flags & FTW_PHYS) | |
425 | flag = FTW_NS; | |
426 | else if (d_type == DT_LNK) | |
427 | flag = FTW_SLN; | |
428 | else | |
429 | { | |
430 | if (dir->streamfd != -1) | |
431 | statres = FXSTATAT (_STAT_VER, dir->streamfd, name, &st, | |
432 | AT_SYMLINK_NOFOLLOW); | |
433 | else | |
434 | statres = LXSTAT (_STAT_VER, name, &st); | |
435 | if (statres == 0 && S_ISLNK (st.st_mode)) | |
436 | flag = FTW_SLN; | |
437 | else | |
438 | flag = FTW_NS; | |
439 | } | |
440 | } | |
441 | else | |
442 | { | |
443 | if (S_ISDIR (st.st_mode)) | |
444 | flag = FTW_D; | |
445 | else if (S_ISLNK (st.st_mode)) | |
446 | flag = FTW_SL; | |
447 | else | |
448 | flag = FTW_F; | |
449 | } | |
450 | ||
451 | if (result == 0 | |
452 | && (flag == FTW_NS | |
453 | || !(data->flags & FTW_MOUNT) || st.st_dev == data->dev)) | |
454 | { | |
455 | if (flag == FTW_D) | |
456 | { | |
457 | if ((data->flags & FTW_PHYS) | |
458 | || (!find_object (data, &st) | |
459 | /* Remember the object. */ | |
460 | && (result = add_object (data, &st)) == 0)) | |
461 | result = ftw_dir (data, &st, dir); | |
462 | } | |
463 | else | |
464 | result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag], | |
465 | &data->ftw); | |
466 | } | |
467 | ||
468 | if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SUBTREE) | |
469 | result = 0; | |
470 | ||
471 | return result; | |
472 | } | |
473 | ||
474 | ||
475 | static int | |
476 | __attribute ((noinline)) | |
477 | ftw_dir (struct ftw_data *data, struct STAT *st, struct dir_data *old_dir) | |
478 | { | |
479 | struct dir_data dir; | |
480 | struct dirent64 *d; | |
481 | int previous_base = data->ftw.base; | |
482 | int result; | |
483 | char *startp; | |
484 | ||
485 | /* Open the stream for this directory. This might require that | |
486 | another stream has to be closed. */ | |
487 | result = open_dir_stream (old_dir == NULL ? NULL : &old_dir->streamfd, | |
488 | data, &dir); | |
489 | if (result != 0) | |
490 | { | |
491 | if (errno == EACCES) | |
492 | /* We cannot read the directory. Signal this with a special flag. */ | |
493 | result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw); | |
494 | ||
495 | return result; | |
496 | } | |
497 | ||
498 | /* First, report the directory (if not depth-first). */ | |
499 | if (!(data->flags & FTW_DEPTH)) | |
500 | { | |
501 | result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw); | |
502 | if (result != 0) | |
503 | { | |
504 | int save_err; | |
505 | fail: | |
506 | save_err = errno; | |
507 | __closedir (dir.stream); | |
508 | dir.streamfd = -1; | |
509 | __set_errno (save_err); | |
510 | ||
511 | if (data->actdir-- == 0) | |
512 | data->actdir = data->maxdir - 1; | |
513 | data->dirstreams[data->actdir] = NULL; | |
514 | return result; | |
515 | } | |
516 | } | |
517 | ||
518 | /* If necessary, change to this directory. */ | |
519 | if (data->flags & FTW_CHDIR) | |
520 | { | |
521 | if (__fchdir (__dirfd (dir.stream)) < 0) | |
522 | { | |
523 | result = -1; | |
524 | goto fail; | |
525 | } | |
526 | } | |
527 | ||
528 | /* Next, update the `struct FTW' information. */ | |
529 | ++data->ftw.level; | |
530 | startp = __rawmemchr (data->dirbuf, '\0'); | |
531 | /* There always must be a directory name. */ | |
532 | assert (startp != data->dirbuf); | |
533 | if (startp[-1] != '/') | |
534 | *startp++ = '/'; | |
535 | data->ftw.base = startp - data->dirbuf; | |
536 | ||
537 | while (dir.stream != NULL && (d = __readdir64 (dir.stream)) != NULL) | |
538 | { | |
539 | int d_type = DT_UNKNOWN; | |
540 | #ifdef _DIRENT_HAVE_D_TYPE | |
541 | d_type = d->d_type; | |
542 | #endif | |
543 | result = process_entry (data, &dir, d->d_name, NAMLEN (d), d_type); | |
544 | if (result != 0) | |
545 | break; | |
546 | } | |
547 | ||
548 | if (dir.stream != NULL) | |
549 | { | |
550 | /* The stream is still open. I.e., we did not need more | |
551 | descriptors. Simply close the stream now. */ | |
552 | int save_err = errno; | |
553 | ||
554 | assert (dir.content == NULL); | |
555 | ||
556 | __closedir (dir.stream); | |
557 | dir.streamfd = -1; | |
558 | __set_errno (save_err); | |
559 | ||
560 | if (data->actdir-- == 0) | |
561 | data->actdir = data->maxdir - 1; | |
562 | data->dirstreams[data->actdir] = NULL; | |
563 | } | |
564 | else | |
565 | { | |
566 | int save_err; | |
567 | char *runp = dir.content; | |
568 | ||
569 | while (result == 0 && *runp != '\0') | |
570 | { | |
571 | char *endp = strchr (runp, '\0'); | |
572 | ||
573 | // XXX Should store the d_type values as well?! | |
574 | result = process_entry (data, &dir, runp, endp - runp, DT_UNKNOWN); | |
575 | ||
576 | runp = endp + 1; | |
577 | } | |
578 | ||
579 | save_err = errno; | |
580 | free (dir.content); | |
581 | __set_errno (save_err); | |
582 | } | |
583 | ||
584 | if ((data->flags & FTW_ACTIONRETVAL) && result == FTW_SKIP_SIBLINGS) | |
585 | result = 0; | |
586 | ||
587 | /* Prepare the return, revert the `struct FTW' information. */ | |
588 | data->dirbuf[data->ftw.base - 1] = '\0'; | |
589 | --data->ftw.level; | |
590 | data->ftw.base = previous_base; | |
591 | ||
592 | /* Finally, if we process depth-first report the directory. */ | |
593 | if (result == 0 && (data->flags & FTW_DEPTH)) | |
594 | result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw); | |
595 | ||
596 | if (old_dir | |
597 | && (data->flags & FTW_CHDIR) | |
598 | && (result == 0 | |
599 | || ((data->flags & FTW_ACTIONRETVAL) | |
600 | && (result != -1 && result != FTW_STOP)))) | |
601 | { | |
602 | /* Change back to the parent directory. */ | |
603 | int done = 0; | |
604 | if (old_dir->stream != NULL) | |
605 | if (__fchdir (__dirfd (old_dir->stream)) == 0) | |
606 | done = 1; | |
607 | ||
608 | if (!done) | |
609 | { | |
610 | if (data->ftw.base == 1) | |
611 | { | |
612 | if (__chdir ("/") < 0) | |
613 | result = -1; | |
614 | } | |
615 | else | |
616 | if (__chdir ("..") < 0) | |
617 | result = -1; | |
618 | } | |
619 | } | |
620 | ||
621 | return result; | |
622 | } | |
623 | ||
624 | ||
625 | static int | |
626 | __attribute ((noinline)) | |
627 | ftw_startup (const char *dir, int is_nftw, void *func, int descriptors, | |
628 | int flags) | |
629 | { | |
630 | struct ftw_data data; | |
631 | struct STAT st; | |
632 | int result = 0; | |
633 | int save_err; | |
634 | int cwdfd = -1; | |
635 | char *cwd = NULL; | |
636 | char *cp; | |
637 | ||
638 | /* First make sure the parameters are reasonable. */ | |
639 | if (dir[0] == '\0') | |
640 | { | |
641 | __set_errno (ENOENT); | |
642 | return -1; | |
643 | } | |
644 | ||
645 | data.maxdir = descriptors < 1 ? 1 : descriptors; | |
646 | data.actdir = 0; | |
647 | data.dirstreams = (struct dir_data **) alloca (data.maxdir | |
648 | * sizeof (struct dir_data *)); | |
649 | memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *)); | |
650 | ||
651 | /* PATH_MAX is always defined when we get here. */ | |
652 | data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX); | |
653 | data.dirbuf = (char *) malloc (data.dirbufsize); | |
654 | if (data.dirbuf == NULL) | |
655 | return -1; | |
656 | cp = __stpcpy (data.dirbuf, dir); | |
657 | /* Strip trailing slashes. */ | |
658 | while (cp > data.dirbuf + 1 && cp[-1] == '/') | |
659 | --cp; | |
660 | *cp = '\0'; | |
661 | ||
662 | data.ftw.level = 0; | |
663 | ||
664 | /* Find basename. */ | |
665 | while (cp > data.dirbuf && cp[-1] != '/') | |
666 | --cp; | |
667 | data.ftw.base = cp - data.dirbuf; | |
668 | ||
669 | data.flags = flags; | |
670 | ||
671 | /* This assignment might seem to be strange but it is what we want. | |
672 | The trick is that the first three arguments to the `ftw' and | |
673 | `nftw' callback functions are equal. Therefore we can call in | |
674 | every case the callback using the format of the `nftw' version | |
675 | and get the correct result since the stack layout for a function | |
676 | call in C allows this. */ | |
677 | data.func = (NFTW_FUNC_T) func; | |
678 | ||
679 | /* Since we internally use the complete set of FTW_* values we need | |
680 | to reduce the value range before calling a `ftw' callback. */ | |
681 | data.cvt_arr = is_nftw ? nftw_arr : ftw_arr; | |
682 | ||
683 | /* No object known so far. */ | |
684 | data.known_objects = NULL; | |
685 | ||
686 | /* Now go to the directory containing the initial file/directory. */ | |
687 | if (flags & FTW_CHDIR) | |
688 | { | |
689 | /* We have to be able to go back to the current working | |
690 | directory. The best way to do this is to use a file | |
691 | descriptor. */ | |
692 | cwdfd = __open (".", O_RDONLY | O_DIRECTORY); | |
693 | if (cwdfd == -1) | |
694 | { | |
695 | /* Try getting the directory name. This can be needed if | |
696 | the current directory is executable but not readable. */ | |
697 | if (errno == EACCES) | |
698 | /* GNU extension ahead. */ | |
699 | cwd = __getcwd (NULL, 0); | |
700 | ||
701 | if (cwd == NULL) | |
702 | goto out_fail; | |
703 | } | |
704 | else if (data.maxdir > 1) | |
705 | /* Account for the file descriptor we use here. */ | |
706 | --data.maxdir; | |
707 | ||
708 | if (data.ftw.base > 0) | |
709 | { | |
710 | /* Change to the directory the file is in. In data.dirbuf | |
711 | we have a writable copy of the file name. Just NUL | |
712 | terminate it for now and change the directory. */ | |
713 | if (data.ftw.base == 1) | |
714 | /* I.e., the file is in the root directory. */ | |
715 | result = __chdir ("/"); | |
716 | else | |
717 | { | |
718 | char ch = data.dirbuf[data.ftw.base - 1]; | |
719 | data.dirbuf[data.ftw.base - 1] = '\0'; | |
720 | result = __chdir (data.dirbuf); | |
721 | data.dirbuf[data.ftw.base - 1] = ch; | |
722 | } | |
723 | } | |
724 | } | |
725 | ||
726 | /* Get stat info for start directory. */ | |
727 | if (result == 0) | |
728 | { | |
729 | const char *name; | |
730 | ||
731 | if (data.flags & FTW_CHDIR) | |
732 | { | |
733 | name = data.dirbuf + data.ftw.base; | |
734 | if (name[0] == '\0') | |
735 | name = "."; | |
736 | } | |
737 | else | |
738 | name = data.dirbuf; | |
739 | ||
740 | if (((flags & FTW_PHYS) | |
741 | ? LXSTAT (_STAT_VER, name, &st) | |
742 | : XSTAT (_STAT_VER, name, &st)) < 0) | |
743 | { | |
744 | if (!(flags & FTW_PHYS) | |
745 | && errno == ENOENT | |
746 | && LXSTAT (_STAT_VER, name, &st) == 0 | |
747 | && S_ISLNK (st.st_mode)) | |
748 | result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN], | |
749 | &data.ftw); | |
750 | else | |
751 | /* No need to call the callback since we cannot say anything | |
752 | about the object. */ | |
753 | result = -1; | |
754 | } | |
755 | else | |
756 | { | |
757 | if (S_ISDIR (st.st_mode)) | |
758 | { | |
759 | /* Remember the device of the initial directory in case | |
760 | FTW_MOUNT is given. */ | |
761 | data.dev = st.st_dev; | |
762 | ||
763 | /* We know this directory now. */ | |
764 | if (!(flags & FTW_PHYS)) | |
765 | result = add_object (&data, &st); | |
766 | ||
767 | if (result == 0) | |
768 | result = ftw_dir (&data, &st, NULL); | |
769 | } | |
770 | else | |
771 | { | |
772 | int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F; | |
773 | ||
774 | result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag], | |
775 | &data.ftw); | |
776 | } | |
777 | } | |
778 | ||
779 | if ((flags & FTW_ACTIONRETVAL) | |
780 | && (result == FTW_SKIP_SUBTREE || result == FTW_SKIP_SIBLINGS)) | |
781 | result = 0; | |
782 | } | |
783 | ||
784 | /* Return to the start directory (if necessary). */ | |
785 | if (cwdfd != -1) | |
786 | { | |
787 | int save_err = errno; | |
788 | __fchdir (cwdfd); | |
789 | __close_nocancel_nostatus (cwdfd); | |
790 | __set_errno (save_err); | |
791 | } | |
792 | else if (cwd != NULL) | |
793 | { | |
794 | int save_err = errno; | |
795 | __chdir (cwd); | |
796 | free (cwd); | |
797 | __set_errno (save_err); | |
798 | } | |
799 | ||
800 | /* Free all memory. */ | |
801 | out_fail: | |
802 | save_err = errno; | |
803 | __tdestroy (data.known_objects, free); | |
804 | free (data.dirbuf); | |
805 | __set_errno (save_err); | |
806 | ||
807 | return result; | |
808 | } | |
809 | ||
810 | ||
811 | ||
812 | /* Entry points. */ | |
813 | ||
814 | int | |
815 | FTW_NAME (const char *path, FTW_FUNC_T func, int descriptors) | |
816 | { | |
817 | return ftw_startup (path, 0, func, descriptors, 0); | |
818 | } | |
819 | ||
820 | #ifndef _LIBC | |
821 | int | |
822 | NFTW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
823 | { | |
824 | return ftw_startup (path, 1, func, descriptors, flags); | |
825 | } | |
826 | #else | |
827 | ||
828 | # include <shlib-compat.h> | |
829 | ||
830 | int NFTW_NEW_NAME (const char *, NFTW_FUNC_T, int, int); | |
831 | ||
832 | int | |
833 | NFTW_NEW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
834 | { | |
835 | if (flags | |
836 | & ~(FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH | FTW_ACTIONRETVAL)) | |
837 | { | |
838 | __set_errno (EINVAL); | |
839 | return -1; | |
840 | } | |
841 | return ftw_startup (path, 1, func, descriptors, flags); | |
842 | } | |
843 | ||
844 | versioned_symbol (libc, NFTW_NEW_NAME, NFTW_NAME, GLIBC_2_3_3); | |
845 | ||
846 | # if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_3_3) | |
847 | ||
848 | /* Older nftw* version just ignored all unknown flags. */ | |
849 | ||
850 | int NFTW_OLD_NAME (const char *, NFTW_FUNC_T, int, int); | |
851 | ||
852 | int | |
853 | attribute_compat_text_section | |
854 | NFTW_OLD_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags) | |
855 | { | |
856 | flags &= (FTW_PHYS | FTW_MOUNT | FTW_CHDIR | FTW_DEPTH); | |
857 | return ftw_startup (path, 1, func, descriptors, flags); | |
858 | } | |
859 | ||
860 | compat_symbol (libc, NFTW_OLD_NAME, NFTW_NAME, GLIBC_2_1); | |
861 | # endif | |
862 | #endif |