1 /* $OpenBSD: fts.c,v 1.43 2009/08/27 16:19:27 millert Exp $ */
3 /*-
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
32 #include <sys/param.h>
33 #include <sys/stat.h>
35 #include <dirent.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <fts.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
43 static FTSENT *fts_alloc(FTS *, char *, size_t);
44 static FTSENT *fts_build(FTS *, int);
45 static void fts_lfree(FTSENT *);
46 static void fts_load(FTS *, FTSENT *);
47 static size_t fts_maxarglen(char * const *);
48 static void fts_padjust(FTS *, FTSENT *);
49 static int fts_palloc(FTS *, size_t);
50 static FTSENT *fts_sort(FTS *, FTSENT *, int);
51 static u_short fts_stat(FTS *, FTSENT *, int);
52 static int fts_safe_changedir(FTS *, FTSENT *, int, char *);
54 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
56 #define CLR(opt) (sp->fts_options &= ~(opt))
57 #define ISSET(opt) (sp->fts_options & (opt))
58 #define SET(opt) (sp->fts_options |= (opt))
60 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
62 /* fts_build flags */
63 #define BCHILD 1 /* fts_children */
64 #define BNAMES 2 /* fts_children, names only */
65 #define BREAD 3 /* fts_read */
67 FTS *
68 fts_open(char * const *argv, int options,
69 int (*compar)(const FTSENT **, const FTSENT **))
70 {
71 FTS *sp;
72 FTSENT *p, *root;
73 int nitems;
74 FTSENT *parent, *tmp;
75 size_t len;
77 /* Options check. */
78 if (options & ~FTS_OPTIONMASK) {
79 errno = EINVAL;
80 return (NULL);
81 }
83 /* Allocate/initialize the stream */
84 if ((sp = calloc(1, sizeof(FTS))) == NULL)
85 return (NULL);
86 sp->fts_compar = compar;
87 sp->fts_options = options;
89 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
90 if (ISSET(FTS_LOGICAL))
91 SET(FTS_NOCHDIR);
93 /*
94 * Start out with 1K of path space, and enough, in any case,
95 * to hold the user's paths.
96 */
97 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
98 goto mem1;
100 /* Allocate/initialize root's parent. */
101 if ((parent = fts_alloc(sp, "", 0)) == NULL)
102 goto mem2;
103 parent->fts_level = FTS_ROOTPARENTLEVEL;
105 /* Allocate/initialize root(s). */
106 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
107 /* Don't allow zero-length paths. */
108 if ((len = strlen(*argv)) == 0) {
109 errno = ENOENT;
110 goto mem3;
111 }
113 if ((p = fts_alloc(sp, *argv, len)) == NULL)
114 goto mem3;
115 p->fts_level = FTS_ROOTLEVEL;
116 p->fts_parent = parent;
117 p->fts_accpath = p->fts_name;
118 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
120 /* Command-line "." and ".." are real directories. */
121 if (p->fts_info == FTS_DOT)
122 p->fts_info = FTS_D;
124 /*
125 * If comparison routine supplied, traverse in sorted
126 * order; otherwise traverse in the order specified.
127 */
128 if (compar) {
129 p->fts_link = root;
130 root = p;
131 } else {
132 p->fts_link = NULL;
133 if (root == NULL)
134 tmp = root = p;
135 else {
136 tmp->fts_link = p;
137 tmp = p;
138 }
139 }
140 }
141 if (compar && nitems > 1)
142 root = fts_sort(sp, root, nitems);
144 /*
145 * Allocate a dummy pointer and make fts_read think that we've just
146 * finished the node before the root(s); set p->fts_info to FTS_INIT
147 * so that everything about the "current" node is ignored.
148 */
149 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
150 goto mem3;
151 sp->fts_cur->fts_link = root;
152 sp->fts_cur->fts_info = FTS_INIT;
154 /*
155 * If using chdir(2), grab a file descriptor pointing to dot to ensure
156 * that we can get back here; this could be avoided for some paths,
157 * but almost certainly not worth the effort. Slashes, symbolic links,
158 * and ".." are all fairly nasty problems. Note, if we can't get the
159 * descriptor we run anyway, just more slowly.
160 */
161 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0)
162 SET(FTS_NOCHDIR);
164 if (nitems == 0)
165 free(parent);
167 return (sp);
169 mem3: fts_lfree(root);
170 free(parent);
171 mem2: free(sp->fts_path);
172 mem1: free(sp);
173 return (NULL);
174 }
176 static void
177 fts_load(FTS *sp, FTSENT *p)
178 {
179 size_t len;
180 char *cp;
182 /*
183 * Load the stream structure for the next traversal. Since we don't
184 * actually enter the directory until after the preorder visit, set
185 * the fts_accpath field specially so the chdir gets done to the right
186 * place and the user can access the first node. From fts_open it's
187 * known that the path will fit.
188 */
189 len = p->fts_pathlen = p->fts_namelen;
190 memmove(sp->fts_path, p->fts_name, len + 1);
191 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
192 len = strlen(++cp);
193 memmove(p->fts_name, cp, len + 1);
194 p->fts_namelen = len;
195 }
196 p->fts_accpath = p->fts_path = sp->fts_path;
197 sp->fts_dev = p->fts_dev;
198 }
200 int
201 fts_close(FTS *sp)
202 {
203 FTSENT *freep, *p;
204 int rfd, error = 0;
206 /*
207 * This still works if we haven't read anything -- the dummy structure
208 * points to the root list, so we step through to the end of the root
209 * list which has a valid parent pointer.
210 */
211 if (sp->fts_cur) {
212 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
213 freep = p;
214 p = p->fts_link ? p->fts_link : p->fts_parent;
215 free(freep);
216 }
217 free(p);
218 }
220 /* Stash the original directory fd if needed. */
221 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd;
223 /* Free up child linked list, sort array, path buffer, stream ptr.*/
224 if (sp->fts_child)
225 fts_lfree(sp->fts_child);
226 if (sp->fts_array)
227 free(sp->fts_array);
228 free(sp->fts_path);
229 free(sp);
231 /* Return to original directory, checking for error. */
232 if (rfd != -1) {
233 int saved_errno;
234 error = fchdir(rfd);
235 saved_errno = errno;
236 (void)close(rfd);
237 errno = saved_errno;
238 }
240 return (error);
241 }
243 /*
244 * Special case of "/" at the end of the path so that slashes aren't
245 * appended which would cause paths to be written as "....//foo".
246 */
247 #define NAPPEND(p) \
248 (p->fts_path[p->fts_pathlen - 1] == '/' \
249 ? p->fts_pathlen - 1 : p->fts_pathlen)
251 FTSENT *
252 fts_read(FTS *sp)
253 {
254 FTSENT *p, *tmp;
255 int instr;
256 char *t;
257 int saved_errno;
259 /* If finished or unrecoverable error, return NULL. */
260 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
261 return (NULL);
263 /* Set current node pointer. */
264 p = sp->fts_cur;
266 /* Save and zero out user instructions. */
267 instr = p->fts_instr;
268 p->fts_instr = FTS_NOINSTR;
270 /* Any type of file may be re-visited; re-stat and re-turn. */
271 if (instr == FTS_AGAIN) {
272 p->fts_info = fts_stat(sp, p, 0);
273 return (p);
274 }
276 /*
277 * Following a symlink -- SLNONE test allows application to see
278 * SLNONE and recover. If indirecting through a symlink, have
279 * keep a pointer to current location. If unable to get that
280 * pointer, follow fails.
281 */
282 if (instr == FTS_FOLLOW &&
283 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
284 p->fts_info = fts_stat(sp, p, 1);
285 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
286 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) {
287 p->fts_errno = errno;
288 p->fts_info = FTS_ERR;
289 } else
290 p->fts_flags |= FTS_SYMFOLLOW;
291 }
292 return (p);
293 }
295 /* Directory in pre-order. */
296 if (p->fts_info == FTS_D) {
297 /* If skipped or crossed mount point, do post-order visit. */
298 if (instr == FTS_SKIP ||
299 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
300 if (p->fts_flags & FTS_SYMFOLLOW)
301 (void)close(p->fts_symfd);
302 if (sp->fts_child) {
303 fts_lfree(sp->fts_child);
304 sp->fts_child = NULL;
305 }
306 p->fts_info = FTS_DP;
307 return (p);
308 }
310 /* Rebuild if only read the names and now traversing. */
311 if (sp->fts_child && ISSET(FTS_NAMEONLY)) {
312 CLR(FTS_NAMEONLY);
313 fts_lfree(sp->fts_child);
314 sp->fts_child = NULL;
315 }
317 /*
318 * Cd to the subdirectory.
319 *
320 * If have already read and now fail to chdir, whack the list
321 * to make the names come out right, and set the parent errno
322 * so the application will eventually get an error condition.
323 * Set the FTS_DONTCHDIR flag so that when we logically change
324 * directories back to the parent we don't do a chdir.
325 *
326 * If haven't read do so. If the read fails, fts_build sets
327 * FTS_STOP or the fts_info field of the node.
328 */
329 if (sp->fts_child) {
330 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
331 p->fts_errno = errno;
332 p->fts_flags |= FTS_DONTCHDIR;
333 for (p = sp->fts_child; p; p = p->fts_link)
334 p->fts_accpath =
335 p->fts_parent->fts_accpath;
336 }
337 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
338 if (ISSET(FTS_STOP))
339 return (NULL);
340 return (p);
341 }
342 p = sp->fts_child;
343 sp->fts_child = NULL;
344 goto name;
345 }
347 /* Move to the next node on this level. */
348 next: tmp = p;
349 if ((p = p->fts_link)) {
350 free(tmp);
352 /*
353 * If reached the top, return to the original directory (or
354 * the root of the tree), and load the paths for the next root.
355 */
356 if (p->fts_level == FTS_ROOTLEVEL) {
357 if (FCHDIR(sp, sp->fts_rfd)) {
358 SET(FTS_STOP);
359 return (NULL);
360 }
361 fts_load(sp, p);
362 return (sp->fts_cur = p);
363 }
365 /*
366 * User may have called fts_set on the node. If skipped,
367 * ignore. If followed, get a file descriptor so we can
368 * get back if necessary.
369 */
370 if (p->fts_instr == FTS_SKIP)
371 goto next;
372 if (p->fts_instr == FTS_FOLLOW) {
373 p->fts_info = fts_stat(sp, p, 1);
374 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
375 if ((p->fts_symfd =
376 open(".", O_RDONLY, 0)) < 0) {
377 p->fts_errno = errno;
378 p->fts_info = FTS_ERR;
379 } else
380 p->fts_flags |= FTS_SYMFOLLOW;
381 }
382 p->fts_instr = FTS_NOINSTR;
383 }
385 name: t = sp->fts_path + NAPPEND(p->fts_parent);
386 *t++ = '/';
387 memmove(t, p->fts_name, p->fts_namelen + 1);
388 return (sp->fts_cur = p);
389 }
391 /* Move up to the parent node. */
392 p = tmp->fts_parent;
393 free(tmp);
395 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
396 /*
397 * Done; free everything up and set errno to 0 so the user
398 * can distinguish between error and EOF.
399 */
400 free(p);
401 errno = 0;
402 return (sp->fts_cur = NULL);
403 }
405 /* NUL terminate the pathname. */
406 sp->fts_path[p->fts_pathlen] = '\0';
408 /*
409 * Return to the parent directory. If at a root node or came through
410 * a symlink, go back through the file descriptor. Otherwise, cd up
411 * one directory.
412 */
413 if (p->fts_level == FTS_ROOTLEVEL) {
414 if (FCHDIR(sp, sp->fts_rfd)) {
415 SET(FTS_STOP);
416 sp->fts_cur = p;
417 return (NULL);
418 }
419 } else if (p->fts_flags & FTS_SYMFOLLOW) {
420 if (FCHDIR(sp, p->fts_symfd)) {
421 saved_errno = errno;
422 (void)close(p->fts_symfd);
423 errno = saved_errno;
424 SET(FTS_STOP);
425 sp->fts_cur = p;
426 return (NULL);
427 }
428 (void)close(p->fts_symfd);
429 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
430 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
431 SET(FTS_STOP);
432 sp->fts_cur = p;
433 return (NULL);
434 }
435 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
436 return (sp->fts_cur = p);
437 }
439 /*
440 * Fts_set takes the stream as an argument although it's not used in this
441 * implementation; it would be necessary if anyone wanted to add global
442 * semantics to fts using fts_set. An error return is allowed for similar
443 * reasons.
444 */
445 /* ARGSUSED */
446 int
447 fts_set(FTS *sp, FTSENT *p, int instr)
448 {
449 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
450 instr != FTS_NOINSTR && instr != FTS_SKIP) {
451 errno = EINVAL;
452 return (1);
453 }
454 p->fts_instr = instr;
455 return (0);
456 }
458 FTSENT *
459 fts_children(FTS *sp, int instr)
460 {
461 FTSENT *p;
462 int fd;
464 if (instr && instr != FTS_NAMEONLY) {
465 errno = EINVAL;
466 return (NULL);
467 }
469 /* Set current node pointer. */
470 p = sp->fts_cur;
472 /*
473 * Errno set to 0 so user can distinguish empty directory from
474 * an error.
475 */
476 errno = 0;
478 /* Fatal errors stop here. */
479 if (ISSET(FTS_STOP))
480 return (NULL);
482 /* Return logical hierarchy of user's arguments. */
483 if (p->fts_info == FTS_INIT)
484 return (p->fts_link);
486 /*
487 * If not a directory being visited in pre-order, stop here. Could
488 * allow FTS_DNR, assuming the user has fixed the problem, but the
489 * same effect is available with FTS_AGAIN.
490 */
491 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
492 return (NULL);
494 /* Free up any previous child list. */
495 if (sp->fts_child)
496 fts_lfree(sp->fts_child);
498 if (instr == FTS_NAMEONLY) {
499 SET(FTS_NAMEONLY);
500 instr = BNAMES;
501 } else
502 instr = BCHILD;
504 /*
505 * If using chdir on a relative path and called BEFORE fts_read does
506 * its chdir to the root of a traversal, we can lose -- we need to
507 * chdir into the subdirectory, and we don't know where the current
508 * directory is, so we can't get back so that the upcoming chdir by
509 * fts_read will work.
510 */
511 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
512 ISSET(FTS_NOCHDIR))
513 return (sp->fts_child = fts_build(sp, instr));
515 if ((fd = open(".", O_RDONLY, 0)) < 0)
516 return (NULL);
517 sp->fts_child = fts_build(sp, instr);
518 if (fchdir(fd)) {
519 (void)close(fd);
520 return (NULL);
521 }
522 (void)close(fd);
523 return (sp->fts_child);
524 }
526 /*
527 * This is the tricky part -- do not casually change *anything* in here. The
528 * idea is to build the linked list of entries that are used by fts_children
529 * and fts_read. There are lots of special cases.
530 *
531 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
532 * set and it's a physical walk (so that symbolic links can't be directories),
533 * we can do things quickly. First, if it's a 4.4BSD file system, the type
534 * of the file is in the directory entry. Otherwise, we assume that the number
535 * of subdirectories in a node is equal to the number of links to the parent.
536 * The former skips all stat calls. The latter skips stat calls in any leaf
537 * directories and for any files after the subdirectories in the directory have
538 * been found, cutting the stat calls by about 2/3.
539 */
540 static FTSENT *
541 fts_build(FTS *sp, int type)
542 {
543 struct dirent *dp;
544 FTSENT *p, *head;
545 FTSENT *cur, *tail;
546 DIR *dirp;
547 void *oldaddr;
548 size_t len, maxlen;
549 int nitems, cderrno, descend, level, nlinks, nostat = 0, doadjust;
550 int saved_errno;
551 char *cp = NULL;
553 /* Set current node pointer. */
554 cur = sp->fts_cur;
556 /*
557 * Open the directory for reading. If this fails, we're done.
558 * If being called from fts_read, set the fts_info field.
559 */
560 if ((dirp = opendir(cur->fts_accpath)) == NULL) {
561 if (type == BREAD) {
562 cur->fts_info = FTS_DNR;
563 cur->fts_errno = errno;
564 }
565 return (NULL);
566 }
568 /*
569 * Nlinks is the number of possible entries of type directory in the
570 * directory if we're cheating on stat calls, 0 if we're not doing
571 * any stat calls at all, -1 if we're doing stats on everything.
572 */
573 if (type == BNAMES)
574 nlinks = 0;
575 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
576 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
577 nostat = 1;
578 } else {
579 nlinks = -1;
580 nostat = 0;
581 }
583 #ifdef notdef
584 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink);
585 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
586 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
587 #endif
588 /*
589 * If we're going to need to stat anything or we want to descend
590 * and stay in the directory, chdir. If this fails we keep going,
591 * but set a flag so we don't chdir after the post-order visit.
592 * We won't be able to stat anything, but we can still return the
593 * names themselves. Note, that since fts_read won't be able to
594 * chdir into the directory, it will have to return different path
595 * names than before, i.e. "a/b" instead of "b". Since the node
596 * has already been visited in pre-order, have to wait until the
597 * post-order visit to return the error. There is a special case
598 * here, if there was nothing to stat then it's not an error to
599 * not be able to stat. This is all fairly nasty. If a program
600 * needed sorted entries or stat information, they had better be
601 * checking FTS_NS on the returned nodes.
602 */
603 cderrno = 0;
604 if (nlinks || type == BREAD) {
605 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
606 if (nlinks && type == BREAD)
607 cur->fts_errno = errno;
608 cur->fts_flags |= FTS_DONTCHDIR;
609 descend = 0;
610 cderrno = errno;
611 (void)closedir(dirp);
612 dirp = NULL;
613 } else
614 descend = 1;
615 } else
616 descend = 0;
618 /*
619 * Figure out the max file name length that can be stored in the
620 * current path -- the inner loop allocates more path as necessary.
621 * We really wouldn't have to do the maxlen calculations here, we
622 * could do them in fts_read before returning the path, but it's a
623 * lot easier here since the length is part of the dirent structure.
624 *
625 * If not changing directories set a pointer so that can just append
626 * each new name into the path.
627 */
628 len = NAPPEND(cur);
629 if (ISSET(FTS_NOCHDIR)) {
630 cp = sp->fts_path + len;
631 *cp++ = '/';
632 }
633 len++;
634 maxlen = sp->fts_pathlen - len;
636 /*
637 * fts_level is a short so we must prevent it from wrapping
638 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
639 */
640 level = cur->fts_level;
641 if (level < FTS_MAXLEVEL)
642 level++;
644 /* Read the directory, attaching each entry to the `link' pointer. */
645 doadjust = 0;
646 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
647 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
648 continue;
650 if (!(p = fts_alloc(sp, dp->d_name, strlen(dp->d_name))))
651 goto mem1;
652 if (strlen(dp->d_name) >= maxlen) { /* include space for NUL */
653 oldaddr = sp->fts_path;
654 if (fts_palloc(sp, strlen(dp->d_name) +len + 1)) {
655 /*
656 * No more memory for path or structures. Save
657 * errno, free up the current structure and the
658 * structures already allocated.
659 */
660 mem1: saved_errno = errno;
661 if (p)
662 free(p);
663 fts_lfree(head);
664 (void)closedir(dirp);
665 cur->fts_info = FTS_ERR;
666 SET(FTS_STOP);
667 errno = saved_errno;
668 return (NULL);
669 }
670 /* Did realloc() change the pointer? */
671 if (oldaddr != sp->fts_path) {
672 doadjust = 1;
673 if (ISSET(FTS_NOCHDIR))
674 cp = sp->fts_path + len;
675 }
676 maxlen = sp->fts_pathlen - len;
677 }
679 p->fts_level = level;
680 p->fts_parent = sp->fts_cur;
681 p->fts_pathlen = len + strlen(dp->d_name);
682 if (p->fts_pathlen < len) {
683 /*
684 * If we wrap, free up the current structure and
685 * the structures already allocated, then error
686 * out with ENAMETOOLONG.
687 */
688 free(p);
689 fts_lfree(head);
690 (void)closedir(dirp);
691 cur->fts_info = FTS_ERR;
692 SET(FTS_STOP);
693 errno = ENAMETOOLONG;
694 return (NULL);
695 }
697 if (cderrno) {
698 if (nlinks) {
699 p->fts_info = FTS_NS;
700 p->fts_errno = cderrno;
701 } else
702 p->fts_info = FTS_NSOK;
703 p->fts_accpath = cur->fts_accpath;
704 } else if (nlinks == 0
705 #ifdef DT_DIR
706 || (nostat &&
707 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
708 #endif
709 ) {
710 p->fts_accpath =
711 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
712 p->fts_info = FTS_NSOK;
713 } else {
714 /* Build a file name for fts_stat to stat. */
715 if (ISSET(FTS_NOCHDIR)) {
716 p->fts_accpath = p->fts_path;
717 memmove(cp, p->fts_name, p->fts_namelen + 1);
718 } else
719 p->fts_accpath = p->fts_name;
720 /* Stat it. */
721 p->fts_info = fts_stat(sp, p, 0);
723 /* Decrement link count if applicable. */
724 if (nlinks > 0 && (p->fts_info == FTS_D ||
725 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
726 --nlinks;
727 }
729 /* We walk in directory order so "ls -f" doesn't get upset. */
730 p->fts_link = NULL;
731 if (head == NULL)
732 head = tail = p;
733 else {
734 tail->fts_link = p;
735 tail = p;
736 }
737 ++nitems;
738 }
739 if (dirp)
740 (void)closedir(dirp);
742 /*
743 * If realloc() changed the address of the path, adjust the
744 * addresses for the rest of the tree and the dir list.
745 */
746 if (doadjust)
747 fts_padjust(sp, head);
749 /*
750 * If not changing directories, reset the path back to original
751 * state.
752 */
753 if (ISSET(FTS_NOCHDIR)) {
754 if (len == sp->fts_pathlen || nitems == 0)
755 --cp;
756 *cp = '\0';
757 }
759 /*
760 * If descended after called from fts_children or after called from
761 * fts_read and nothing found, get back. At the root level we use
762 * the saved fd; if one of fts_open()'s arguments is a relative path
763 * to an empty directory, we wind up here with no other way back. If
764 * can't get back, we're done.
765 */
766 if (descend && (type == BCHILD || !nitems) &&
767 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) :
768 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
769 cur->fts_info = FTS_ERR;
770 SET(FTS_STOP);
771 return (NULL);
772 }
774 /* If didn't find anything, return NULL. */
775 if (!nitems) {
776 if (type == BREAD)
777 cur->fts_info = FTS_DP;
778 return (NULL);
779 }
781 /* Sort the entries. */
782 if (sp->fts_compar && nitems > 1)
783 head = fts_sort(sp, head, nitems);
784 return (head);
785 }
787 static u_short
788 fts_stat(FTS *sp, FTSENT *p, int follow)
789 {
790 FTSENT *t;
791 dev_t dev;
792 ino_t ino;
793 struct stat *sbp, sb;
794 int saved_errno;
796 /* If user needs stat info, stat buffer already allocated. */
797 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
799 /*
800 * If doing a logical walk, or application requested FTS_FOLLOW, do
801 * a stat(2). If that fails, check for a non-existent symlink. If
802 * fail, set the errno from the stat call.
803 */
804 if (ISSET(FTS_LOGICAL) || follow) {
805 if (stat(p->fts_accpath, sbp)) {
806 saved_errno = errno;
807 if (!lstat(p->fts_accpath, sbp)) {
808 errno = 0;
809 return (FTS_SLNONE);
810 }
811 p->fts_errno = saved_errno;
812 goto err;
813 }
814 } else if (lstat(p->fts_accpath, sbp)) {
815 p->fts_errno = errno;
816 err: memset(sbp, 0, sizeof(struct stat));
817 return (FTS_NS);
818 }
820 if (S_ISDIR(sbp->st_mode)) {
821 /*
822 * Set the device/inode. Used to find cycles and check for
823 * crossing mount points. Also remember the link count, used
824 * in fts_build to limit the number of stat calls. It is
825 * understood that these fields are only referenced if fts_info
826 * is set to FTS_D.
827 */
828 dev = p->fts_dev = sbp->st_dev;
829 ino = p->fts_ino = sbp->st_ino;
830 p->fts_nlink = sbp->st_nlink;
832 if (ISDOT(p->fts_name))
833 return (FTS_DOT);
835 /*
836 * Cycle detection is done by brute force when the directory
837 * is first encountered. If the tree gets deep enough or the
838 * number of symbolic links to directories is high enough,
839 * something faster might be worthwhile.
840 */
841 for (t = p->fts_parent;
842 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
843 if (ino == t->fts_ino && dev == t->fts_dev) {
844 p->fts_cycle = t;
845 return (FTS_DC);
846 }
847 return (FTS_D);
848 }
849 if (S_ISLNK(sbp->st_mode))
850 return (FTS_SL);
851 if (S_ISREG(sbp->st_mode))
852 return (FTS_F);
853 return (FTS_DEFAULT);
854 }
856 static FTSENT *
857 fts_sort(FTS *sp, FTSENT *head, int nitems)
858 {
859 FTSENT **ap, *p;
861 /*
862 * Construct an array of pointers to the structures and call qsort(3).
863 * Reassemble the array in the order returned by qsort. If unable to
864 * sort for memory reasons, return the directory entries in their
865 * current order. Allocate enough space for the current needs plus
866 * 40 so don't realloc one entry at a time.
867 */
868 if (nitems > sp->fts_nitems) {
869 struct _ftsent **a;
871 sp->fts_nitems = nitems + 40;
872 if ((a = realloc(sp->fts_array,
873 sp->fts_nitems * sizeof(FTSENT *))) == NULL) {
874 if (sp->fts_array)
875 free(sp->fts_array);
876 sp->fts_array = NULL;
877 sp->fts_nitems = 0;
878 return (head);
879 }
880 sp->fts_array = a;
881 }
882 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
883 *ap++ = p;
884 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar);
885 for (head = *(ap = sp->fts_array); --nitems; ++ap)
886 ap[0]->fts_link = ap[1];
887 ap[0]->fts_link = NULL;
888 return (head);
889 }
891 static FTSENT *
892 fts_alloc(FTS *sp, char *name, size_t namelen)
893 {
894 FTSENT *p;
895 size_t len;
897 /*
898 * The file name is a variable length array and no stat structure is
899 * necessary if the user has set the nostat bit. Allocate the FTSENT
900 * structure, the file name and the stat structure in one chunk, but
901 * be careful that the stat structure is reasonably aligned. Since the
902 * fts_name field is declared to be of size 1, the fts_name pointer is
903 * namelen + 2 before the first possible address of the stat structure.
904 */
905 len = sizeof(FTSENT) + namelen;
906 if (!ISSET(FTS_NOSTAT))
907 len += sizeof(struct stat) + ALIGNBYTES;
908 if ((p = malloc(len)) == NULL)
909 return (NULL);
911 memset(p, 0, len);
912 p->fts_path = sp->fts_path;
913 p->fts_namelen = namelen;
914 p->fts_instr = FTS_NOINSTR;
915 if (!ISSET(FTS_NOSTAT))
916 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2);
917 memcpy(p->fts_name, name, namelen);
919 return (p);
920 }
922 static void
923 fts_lfree(FTSENT *head)
924 {
925 FTSENT *p;
927 /* Free a linked list of structures. */
928 while ((p = head)) {
929 head = head->fts_link;
930 free(p);
931 }
932 }
934 /*
935 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
936 * Most systems will allow creation of paths much longer than MAXPATHLEN, even
937 * though the kernel won't resolve them. Add the size (not just what's needed)
938 * plus 256 bytes so don't realloc the path 2 bytes at a time.
939 */
940 static int
941 fts_palloc(FTS *sp, size_t more)
942 {
943 char *p;
945 /*
946 * Check for possible wraparound.
947 */
948 more += 256;
949 if (sp->fts_pathlen + more < sp->fts_pathlen) {
950 if (sp->fts_path)
951 free(sp->fts_path);
952 sp->fts_path = NULL;
953 errno = ENAMETOOLONG;
954 return (1);
955 }
956 sp->fts_pathlen += more;
957 p = realloc(sp->fts_path, sp->fts_pathlen);
958 if (p == NULL) {
959 if (sp->fts_path)
960 free(sp->fts_path);
961 sp->fts_path = NULL;
962 return (1);
963 }
964 sp->fts_path = p;
965 return (0);
966 }
968 /*
969 * When the path is realloc'd, have to fix all of the pointers in structures
970 * already returned.
971 */
972 static void
973 fts_padjust(FTS *sp, FTSENT *head)
974 {
975 FTSENT *p;
976 char *addr = sp->fts_path;
978 #define ADJUST(p) { \
979 if ((p)->fts_accpath != (p)->fts_name) { \
980 (p)->fts_accpath = \
981 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
982 } \
983 (p)->fts_path = addr; \
984 }
985 /* Adjust the current set of children. */
986 for (p = sp->fts_child; p; p = p->fts_link)
987 ADJUST(p);
989 /* Adjust the rest of the tree, including the current level. */
990 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
991 ADJUST(p);
992 p = p->fts_link ? p->fts_link : p->fts_parent;
993 }
994 }
996 static size_t
997 fts_maxarglen(char * const *argv)
998 {
999 size_t len, max;
1001 for (max = 0; *argv; ++argv)
1002 if ((len = strlen(*argv)) > max)
1003 max = len;
1004 return (max + 1);
1005 }
1007 /*
1008 * Change to dir specified by fd or p->fts_accpath without getting
1009 * tricked by someone changing the world out from underneath us.
1010 * Assumes p->fts_dev and p->fts_ino are filled in.
1011 */
1012 static int
1013 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
1014 {
1015 int ret, oerrno, newfd;
1016 struct stat sb;
1018 newfd = fd;
1019 if (ISSET(FTS_NOCHDIR))
1020 return (0);
1021 if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0)
1022 return (-1);
1023 if (fstat(newfd, &sb)) {
1024 ret = -1;
1025 goto bail;
1026 }
1027 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1028 errno = ENOENT; /* disinformation */
1029 ret = -1;
1030 goto bail;
1031 }
1032 ret = fchdir(newfd);
1033 bail:
1034 oerrno = errno;
1035 if (fd < 0)
1036 (void)close(newfd);
1037 errno = oerrno;
1038 return (ret);
1039 }