1 /* $OpenBSD: fts.c,v 1.46 2014/05/25 17:47:04 tedu Exp $ */
2
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 */
31
32 #include <sys/param.h>
33 #include <sys/stat.h>
34
35 #include <dirent.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <fts.h>
39 #include <limits.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 static FTSENT *fts_alloc(FTS *, char *, size_t);
45 static FTSENT *fts_build(FTS *, int);
46 static void fts_lfree(FTSENT *);
47 static void fts_load(FTS *, FTSENT *);
48 static size_t fts_maxarglen(char * const *);
49 static void fts_padjust(FTS *, FTSENT *);
50 static int fts_palloc(FTS *, size_t);
51 static FTSENT *fts_sort(FTS *, FTSENT *, int);
52 static u_short fts_stat(FTS *, FTSENT *, int);
53 static int fts_safe_changedir(FTS *, FTSENT *, int, char *);
54
55 #define ALIGNBYTES (sizeof(uintptr_t) - 1)
56 #define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES)
57
58 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
59
60 #define CLR(opt) (sp->fts_options &= ~(opt))
61 #define ISSET(opt) (sp->fts_options & (opt))
62 #define SET(opt) (sp->fts_options |= (opt))
63
64 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
65
66 /* fts_build flags */
67 #define BCHILD 1 /* fts_children */
68 #define BNAMES 2 /* fts_children, names only */
69 #define BREAD 3 /* fts_read */
70
71 FTS *
fts_open(char * const * argv,int options,int (* compar)(const FTSENT **,const FTSENT **))72 fts_open(char * const *argv, int options,
73 int (*compar)(const FTSENT **, const FTSENT **))
74 {
75 FTS *sp;
76 FTSENT *p, *root;
77 int nitems;
78 FTSENT *parent, *tmp;
79 size_t len;
80
81 /* Options check. */
82 if (options & ~FTS_OPTIONMASK) {
83 errno = EINVAL;
84 return (NULL);
85 }
86
87 /* Allocate/initialize the stream */
88 if ((sp = calloc(1, sizeof(FTS))) == NULL)
89 return (NULL);
90 sp->fts_compar = compar;
91 sp->fts_options = options;
92
93 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
94 if (ISSET(FTS_LOGICAL))
95 SET(FTS_NOCHDIR);
96
97 /*
98 * Start out with 1K of path space, and enough, in any case,
99 * to hold the user's paths.
100 */
101 if (fts_palloc(sp, MAX(fts_maxarglen(argv), PATH_MAX)))
102 goto mem1;
103
104 /* Allocate/initialize root's parent. */
105 if ((parent = fts_alloc(sp, "", 0)) == NULL)
106 goto mem2;
107 parent->fts_level = FTS_ROOTPARENTLEVEL;
108
109 /* Allocate/initialize root(s). */
110 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
111 /* Don't allow zero-length paths. */
112 if ((len = strlen(*argv)) == 0) {
113 errno = ENOENT;
114 goto mem3;
115 }
116
117 if ((p = fts_alloc(sp, *argv, len)) == NULL)
118 goto mem3;
119 p->fts_level = FTS_ROOTLEVEL;
120 p->fts_parent = parent;
121 p->fts_accpath = p->fts_name;
122 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
123
124 /* Command-line "." and ".." are real directories. */
125 if (p->fts_info == FTS_DOT)
126 p->fts_info = FTS_D;
127
128 /*
129 * If comparison routine supplied, traverse in sorted
130 * order; otherwise traverse in the order specified.
131 */
132 if (compar) {
133 p->fts_link = root;
134 root = p;
135 } else {
136 p->fts_link = NULL;
137 if (root == NULL)
138 tmp = root = p;
139 else {
140 tmp->fts_link = p;
141 tmp = p;
142 }
143 }
144 }
145 if (compar && nitems > 1)
146 root = fts_sort(sp, root, nitems);
147
148 /*
149 * Allocate a dummy pointer and make fts_read think that we've just
150 * finished the node before the root(s); set p->fts_info to FTS_INIT
151 * so that everything about the "current" node is ignored.
152 */
153 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
154 goto mem3;
155 sp->fts_cur->fts_link = root;
156 sp->fts_cur->fts_info = FTS_INIT;
157
158 /*
159 * If using chdir(2), grab a file descriptor pointing to dot to ensure
160 * that we can get back here; this could be avoided for some paths,
161 * but almost certainly not worth the effort. Slashes, symbolic links,
162 * and ".." are all fairly nasty problems. Note, if we can't get the
163 * descriptor we run anyway, just more slowly.
164 */
165 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0)
166 SET(FTS_NOCHDIR);
167
168 if (nitems == 0)
169 free(parent);
170
171 return (sp);
172
173 mem3: fts_lfree(root);
174 free(parent);
175 mem2: free(sp->fts_path);
176 mem1: free(sp);
177 return (NULL);
178 }
179
180 static void
fts_load(FTS * sp,FTSENT * p)181 fts_load(FTS *sp, FTSENT *p)
182 {
183 size_t len;
184 char *cp;
185
186 /*
187 * Load the stream structure for the next traversal. Since we don't
188 * actually enter the directory until after the preorder visit, set
189 * the fts_accpath field specially so the chdir gets done to the right
190 * place and the user can access the first node. From fts_open it's
191 * known that the path will fit.
192 */
193 len = p->fts_pathlen = p->fts_namelen;
194 memmove(sp->fts_path, p->fts_name, len + 1);
195 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
196 len = strlen(++cp);
197 memmove(p->fts_name, cp, len + 1);
198 p->fts_namelen = len;
199 }
200 p->fts_accpath = p->fts_path = sp->fts_path;
201 sp->fts_dev = p->fts_dev;
202 }
203
204 int
fts_close(FTS * sp)205 fts_close(FTS *sp)
206 {
207 FTSENT *freep, *p;
208 int rfd, error = 0;
209
210 /*
211 * This still works if we haven't read anything -- the dummy structure
212 * points to the root list, so we step through to the end of the root
213 * list which has a valid parent pointer.
214 */
215 if (sp->fts_cur) {
216 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
217 freep = p;
218 p = p->fts_link ? p->fts_link : p->fts_parent;
219 free(freep);
220 }
221 free(p);
222 }
223
224 /* Stash the original directory fd if needed. */
225 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd;
226
227 /* Free up child linked list, sort array, path buffer, stream ptr.*/
228 if (sp->fts_child)
229 fts_lfree(sp->fts_child);
230 if (sp->fts_array)
231 free(sp->fts_array);
232 free(sp->fts_path);
233 free(sp);
234
235 /* Return to original directory, checking for error. */
236 if (rfd != -1) {
237 int saved_errno;
238 error = fchdir(rfd);
239 saved_errno = errno;
240 (void)close(rfd);
241 errno = saved_errno;
242 }
243
244 return (error);
245 }
246
247 /*
248 * Special case of "/" at the end of the path so that slashes aren't
249 * appended which would cause paths to be written as "....//foo".
250 */
251 #define NAPPEND(p) \
252 (p->fts_path[p->fts_pathlen - 1] == '/' \
253 ? p->fts_pathlen - 1 : p->fts_pathlen)
254
255 FTSENT *
fts_read(FTS * sp)256 fts_read(FTS *sp)
257 {
258 FTSENT *p, *tmp;
259 int instr;
260 char *t;
261 int saved_errno;
262
263 /* If finished or unrecoverable error, return NULL. */
264 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
265 return (NULL);
266
267 /* Set current node pointer. */
268 p = sp->fts_cur;
269
270 /* Save and zero out user instructions. */
271 instr = p->fts_instr;
272 p->fts_instr = FTS_NOINSTR;
273
274 /* Any type of file may be re-visited; re-stat and re-turn. */
275 if (instr == FTS_AGAIN) {
276 p->fts_info = fts_stat(sp, p, 0);
277 return (p);
278 }
279
280 /*
281 * Following a symlink -- SLNONE test allows application to see
282 * SLNONE and recover. If indirecting through a symlink, have
283 * keep a pointer to current location. If unable to get that
284 * pointer, follow fails.
285 */
286 if (instr == FTS_FOLLOW &&
287 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
288 p->fts_info = fts_stat(sp, p, 1);
289 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
290 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) {
291 p->fts_errno = errno;
292 p->fts_info = FTS_ERR;
293 } else
294 p->fts_flags |= FTS_SYMFOLLOW;
295 }
296 return (p);
297 }
298
299 /* Directory in pre-order. */
300 if (p->fts_info == FTS_D) {
301 /* If skipped or crossed mount point, do post-order visit. */
302 if (instr == FTS_SKIP ||
303 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
304 if (p->fts_flags & FTS_SYMFOLLOW)
305 (void)close(p->fts_symfd);
306 if (sp->fts_child) {
307 fts_lfree(sp->fts_child);
308 sp->fts_child = NULL;
309 }
310 p->fts_info = FTS_DP;
311 return (p);
312 }
313
314 /* Rebuild if only read the names and now traversing. */
315 if (sp->fts_child && ISSET(FTS_NAMEONLY)) {
316 CLR(FTS_NAMEONLY);
317 fts_lfree(sp->fts_child);
318 sp->fts_child = NULL;
319 }
320
321 /*
322 * Cd to the subdirectory.
323 *
324 * If have already read and now fail to chdir, whack the list
325 * to make the names come out right, and set the parent errno
326 * so the application will eventually get an error condition.
327 * Set the FTS_DONTCHDIR flag so that when we logically change
328 * directories back to the parent we don't do a chdir.
329 *
330 * If haven't read do so. If the read fails, fts_build sets
331 * FTS_STOP or the fts_info field of the node.
332 */
333 if (sp->fts_child) {
334 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
335 p->fts_errno = errno;
336 p->fts_flags |= FTS_DONTCHDIR;
337 for (p = sp->fts_child; p; p = p->fts_link)
338 p->fts_accpath =
339 p->fts_parent->fts_accpath;
340 }
341 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
342 if (ISSET(FTS_STOP))
343 return (NULL);
344 return (p);
345 }
346 p = sp->fts_child;
347 sp->fts_child = NULL;
348 goto name;
349 }
350
351 /* Move to the next node on this level. */
352 next: tmp = p;
353 if ((p = p->fts_link)) {
354 free(tmp);
355
356 /*
357 * If reached the top, return to the original directory (or
358 * the root of the tree), and load the paths for the next root.
359 */
360 if (p->fts_level == FTS_ROOTLEVEL) {
361 if (FCHDIR(sp, sp->fts_rfd)) {
362 SET(FTS_STOP);
363 return (NULL);
364 }
365 fts_load(sp, p);
366 return (sp->fts_cur = p);
367 }
368
369 /*
370 * User may have called fts_set on the node. If skipped,
371 * ignore. If followed, get a file descriptor so we can
372 * get back if necessary.
373 */
374 if (p->fts_instr == FTS_SKIP)
375 goto next;
376 if (p->fts_instr == FTS_FOLLOW) {
377 p->fts_info = fts_stat(sp, p, 1);
378 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
379 if ((p->fts_symfd =
380 open(".", O_RDONLY, 0)) < 0) {
381 p->fts_errno = errno;
382 p->fts_info = FTS_ERR;
383 } else
384 p->fts_flags |= FTS_SYMFOLLOW;
385 }
386 p->fts_instr = FTS_NOINSTR;
387 }
388
389 name: t = sp->fts_path + NAPPEND(p->fts_parent);
390 *t++ = '/';
391 memmove(t, p->fts_name, p->fts_namelen + 1);
392 return (sp->fts_cur = p);
393 }
394
395 /* Move up to the parent node. */
396 p = tmp->fts_parent;
397 free(tmp);
398
399 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
400 /*
401 * Done; free everything up and set errno to 0 so the user
402 * can distinguish between error and EOF.
403 */
404 free(p);
405 errno = 0;
406 return (sp->fts_cur = NULL);
407 }
408
409 /* NUL terminate the pathname. */
410 sp->fts_path[p->fts_pathlen] = '\0';
411
412 /*
413 * Return to the parent directory. If at a root node or came through
414 * a symlink, go back through the file descriptor. Otherwise, cd up
415 * one directory.
416 */
417 if (p->fts_level == FTS_ROOTLEVEL) {
418 if (FCHDIR(sp, sp->fts_rfd)) {
419 SET(FTS_STOP);
420 sp->fts_cur = p;
421 return (NULL);
422 }
423 } else if (p->fts_flags & FTS_SYMFOLLOW) {
424 if (FCHDIR(sp, p->fts_symfd)) {
425 saved_errno = errno;
426 (void)close(p->fts_symfd);
427 errno = saved_errno;
428 SET(FTS_STOP);
429 sp->fts_cur = p;
430 return (NULL);
431 }
432 (void)close(p->fts_symfd);
433 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
434 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
435 SET(FTS_STOP);
436 sp->fts_cur = p;
437 return (NULL);
438 }
439 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
440 return (sp->fts_cur = p);
441 }
442
443 /*
444 * Fts_set takes the stream as an argument although it's not used in this
445 * implementation; it would be necessary if anyone wanted to add global
446 * semantics to fts using fts_set. An error return is allowed for similar
447 * reasons.
448 */
449 /* ARGSUSED */
450 int
fts_set(FTS * sp __unused,FTSENT * p,int instr)451 fts_set(FTS *sp __unused, FTSENT *p, int instr)
452 {
453 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
454 instr != FTS_NOINSTR && instr != FTS_SKIP) {
455 errno = EINVAL;
456 return (1);
457 }
458 p->fts_instr = instr;
459 return (0);
460 }
461
462 FTSENT *
fts_children(FTS * sp,int instr)463 fts_children(FTS *sp, int instr)
464 {
465 FTSENT *p;
466 int fd;
467
468 if (instr && instr != FTS_NAMEONLY) {
469 errno = EINVAL;
470 return (NULL);
471 }
472
473 /* Set current node pointer. */
474 p = sp->fts_cur;
475
476 /*
477 * Errno set to 0 so user can distinguish empty directory from
478 * an error.
479 */
480 errno = 0;
481
482 /* Fatal errors stop here. */
483 if (ISSET(FTS_STOP))
484 return (NULL);
485
486 /* Return logical hierarchy of user's arguments. */
487 if (p->fts_info == FTS_INIT)
488 return (p->fts_link);
489
490 /*
491 * If not a directory being visited in pre-order, stop here. Could
492 * allow FTS_DNR, assuming the user has fixed the problem, but the
493 * same effect is available with FTS_AGAIN.
494 */
495 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
496 return (NULL);
497
498 /* Free up any previous child list. */
499 if (sp->fts_child)
500 fts_lfree(sp->fts_child);
501
502 if (instr == FTS_NAMEONLY) {
503 SET(FTS_NAMEONLY);
504 instr = BNAMES;
505 } else
506 instr = BCHILD;
507
508 /*
509 * If using chdir on a relative path and called BEFORE fts_read does
510 * its chdir to the root of a traversal, we can lose -- we need to
511 * chdir into the subdirectory, and we don't know where the current
512 * directory is, so we can't get back so that the upcoming chdir by
513 * fts_read will work.
514 */
515 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
516 ISSET(FTS_NOCHDIR))
517 return (sp->fts_child = fts_build(sp, instr));
518
519 if ((fd = open(".", O_RDONLY, 0)) < 0)
520 return (NULL);
521 sp->fts_child = fts_build(sp, instr);
522 if (fchdir(fd)) {
523 (void)close(fd);
524 return (NULL);
525 }
526 (void)close(fd);
527 return (sp->fts_child);
528 }
529
530 /*
531 * This is the tricky part -- do not casually change *anything* in here. The
532 * idea is to build the linked list of entries that are used by fts_children
533 * and fts_read. There are lots of special cases.
534 *
535 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
536 * set and it's a physical walk (so that symbolic links can't be directories),
537 * we can do things quickly. First, if it's a 4.4BSD file system, the type
538 * of the file is in the directory entry. Otherwise, we assume that the number
539 * of subdirectories in a node is equal to the number of links to the parent.
540 * The former skips all stat calls. The latter skips stat calls in any leaf
541 * directories and for any files after the subdirectories in the directory have
542 * been found, cutting the stat calls by about 2/3.
543 */
544 static FTSENT *
fts_build(FTS * sp,int type)545 fts_build(FTS *sp, int type)
546 {
547 struct dirent *dp;
548 FTSENT *p, *head;
549 FTSENT *cur, *tail;
550 DIR *dirp;
551 void *oldaddr;
552 size_t len, maxlen;
553 int nitems, cderrno, descend, level, nlinks, nostat = 0, doadjust;
554 int saved_errno;
555 char *cp = NULL;
556
557 /* Set current node pointer. */
558 cur = sp->fts_cur;
559
560 /*
561 * Open the directory for reading. If this fails, we're done.
562 * If being called from fts_read, set the fts_info field.
563 */
564 if ((dirp = opendir(cur->fts_accpath)) == NULL) {
565 if (type == BREAD) {
566 cur->fts_info = FTS_DNR;
567 cur->fts_errno = errno;
568 }
569 return (NULL);
570 }
571
572 /*
573 * Nlinks is the number of possible entries of type directory in the
574 * directory if we're cheating on stat calls, 0 if we're not doing
575 * any stat calls at all, -1 if we're doing stats on everything.
576 */
577 if (type == BNAMES)
578 nlinks = 0;
579 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
580 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
581 nostat = 1;
582 } else {
583 nlinks = -1;
584 nostat = 0;
585 }
586
587 #ifdef notdef
588 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink);
589 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
590 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
591 #endif
592 /*
593 * If we're going to need to stat anything or we want to descend
594 * and stay in the directory, chdir. If this fails we keep going,
595 * but set a flag so we don't chdir after the post-order visit.
596 * We won't be able to stat anything, but we can still return the
597 * names themselves. Note, that since fts_read won't be able to
598 * chdir into the directory, it will have to return different path
599 * names than before, i.e. "a/b" instead of "b". Since the node
600 * has already been visited in pre-order, have to wait until the
601 * post-order visit to return the error. There is a special case
602 * here, if there was nothing to stat then it's not an error to
603 * not be able to stat. This is all fairly nasty. If a program
604 * needed sorted entries or stat information, they had better be
605 * checking FTS_NS on the returned nodes.
606 */
607 cderrno = 0;
608 if (nlinks || type == BREAD) {
609 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
610 if (nlinks && type == BREAD)
611 cur->fts_errno = errno;
612 cur->fts_flags |= FTS_DONTCHDIR;
613 descend = 0;
614 cderrno = errno;
615 (void)closedir(dirp);
616 dirp = NULL;
617 } else
618 descend = 1;
619 } else
620 descend = 0;
621
622 /*
623 * Figure out the max file name length that can be stored in the
624 * current path -- the inner loop allocates more path as necessary.
625 * We really wouldn't have to do the maxlen calculations here, we
626 * could do them in fts_read before returning the path, but it's a
627 * lot easier here since the length is part of the dirent structure.
628 *
629 * If not changing directories set a pointer so that can just append
630 * each new name into the path.
631 */
632 len = NAPPEND(cur);
633 if (ISSET(FTS_NOCHDIR)) {
634 cp = sp->fts_path + len;
635 *cp++ = '/';
636 }
637 len++;
638 maxlen = sp->fts_pathlen - len;
639
640 /*
641 * fts_level is signed so we must prevent it from wrapping
642 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
643 */
644 level = cur->fts_level;
645 if (level < FTS_MAXLEVEL)
646 level++;
647
648 /* Read the directory, attaching each entry to the `link' pointer. */
649 doadjust = 0;
650 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
651 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
652 continue;
653
654 if (!(p = fts_alloc(sp, dp->d_name, strlen(dp->d_name))))
655 goto mem1;
656 if (strlen(dp->d_name) >= maxlen) { /* include space for NUL */
657 oldaddr = sp->fts_path;
658 if (fts_palloc(sp, strlen(dp->d_name) +len + 1)) {
659 /*
660 * No more memory for path or structures. Save
661 * errno, free up the current structure and the
662 * structures already allocated.
663 */
664 mem1: saved_errno = errno;
665 if (p)
666 free(p);
667 fts_lfree(head);
668 (void)closedir(dirp);
669 cur->fts_info = FTS_ERR;
670 SET(FTS_STOP);
671 errno = saved_errno;
672 return (NULL);
673 }
674 /* Did realloc() change the pointer? */
675 if (oldaddr != sp->fts_path) {
676 doadjust = 1;
677 if (ISSET(FTS_NOCHDIR))
678 cp = sp->fts_path + len;
679 }
680 maxlen = sp->fts_pathlen - len;
681 }
682
683 p->fts_level = level;
684 p->fts_parent = sp->fts_cur;
685 p->fts_pathlen = len + strlen(dp->d_name);
686 if (p->fts_pathlen < len) {
687 /*
688 * If we wrap, free up the current structure and
689 * the structures already allocated, then error
690 * out with ENAMETOOLONG.
691 */
692 free(p);
693 fts_lfree(head);
694 (void)closedir(dirp);
695 cur->fts_info = FTS_ERR;
696 SET(FTS_STOP);
697 errno = ENAMETOOLONG;
698 return (NULL);
699 }
700
701 if (cderrno) {
702 if (nlinks) {
703 p->fts_info = FTS_NS;
704 p->fts_errno = cderrno;
705 } else
706 p->fts_info = FTS_NSOK;
707 p->fts_accpath = cur->fts_accpath;
708 } else if (nlinks == 0
709 #ifdef DT_DIR
710 || (nostat &&
711 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
712 #endif
713 ) {
714 p->fts_accpath =
715 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
716 p->fts_info = FTS_NSOK;
717 } else {
718 /* Build a file name for fts_stat to stat. */
719 if (ISSET(FTS_NOCHDIR)) {
720 p->fts_accpath = p->fts_path;
721 memmove(cp, p->fts_name, p->fts_namelen + 1);
722 } else
723 p->fts_accpath = p->fts_name;
724 /* Stat it. */
725 p->fts_info = fts_stat(sp, p, 0);
726
727 /* Decrement link count if applicable. */
728 if (nlinks > 0 && (p->fts_info == FTS_D ||
729 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
730 --nlinks;
731 }
732
733 /* We walk in directory order so "ls -f" doesn't get upset. */
734 p->fts_link = NULL;
735 if (head == NULL)
736 head = tail = p;
737 else {
738 tail->fts_link = p;
739 tail = p;
740 }
741 ++nitems;
742 }
743 if (dirp)
744 (void)closedir(dirp);
745
746 /*
747 * If realloc() changed the address of the path, adjust the
748 * addresses for the rest of the tree and the dir list.
749 */
750 if (doadjust)
751 fts_padjust(sp, head);
752
753 /*
754 * If not changing directories, reset the path back to original
755 * state.
756 */
757 if (ISSET(FTS_NOCHDIR)) {
758 if (len == sp->fts_pathlen || nitems == 0)
759 --cp;
760 *cp = '\0';
761 }
762
763 /*
764 * If descended after called from fts_children or after called from
765 * fts_read and nothing found, get back. At the root level we use
766 * the saved fd; if one of fts_open()'s arguments is a relative path
767 * to an empty directory, we wind up here with no other way back. If
768 * can't get back, we're done.
769 */
770 if (descend && (type == BCHILD || !nitems) &&
771 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) :
772 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
773 cur->fts_info = FTS_ERR;
774 SET(FTS_STOP);
775 return (NULL);
776 }
777
778 /* If didn't find anything, return NULL. */
779 if (!nitems) {
780 if (type == BREAD)
781 cur->fts_info = FTS_DP;
782 return (NULL);
783 }
784
785 /* Sort the entries. */
786 if (sp->fts_compar && nitems > 1)
787 head = fts_sort(sp, head, nitems);
788 return (head);
789 }
790
791 static u_short
fts_stat(FTS * sp,FTSENT * p,int follow)792 fts_stat(FTS *sp, FTSENT *p, int follow)
793 {
794 FTSENT *t;
795 dev_t dev;
796 ino_t ino;
797 struct stat *sbp, sb;
798 int saved_errno;
799
800 /* If user needs stat info, stat buffer already allocated. */
801 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
802
803 /*
804 * If doing a logical walk, or application requested FTS_FOLLOW, do
805 * a stat(2). If that fails, check for a non-existent symlink. If
806 * fail, set the errno from the stat call.
807 */
808 if (ISSET(FTS_LOGICAL) || follow) {
809 if (stat(p->fts_accpath, sbp)) {
810 saved_errno = errno;
811 if (!lstat(p->fts_accpath, sbp)) {
812 errno = 0;
813 return (FTS_SLNONE);
814 }
815 p->fts_errno = saved_errno;
816 goto err;
817 }
818 } else if (lstat(p->fts_accpath, sbp)) {
819 p->fts_errno = errno;
820 err: memset(sbp, 0, sizeof(struct stat));
821 return (FTS_NS);
822 }
823
824 if (S_ISDIR(sbp->st_mode)) {
825 /*
826 * Set the device/inode. Used to find cycles and check for
827 * crossing mount points. Also remember the link count, used
828 * in fts_build to limit the number of stat calls. It is
829 * understood that these fields are only referenced if fts_info
830 * is set to FTS_D.
831 */
832 dev = p->fts_dev = sbp->st_dev;
833 ino = p->fts_ino = sbp->st_ino;
834 p->fts_nlink = sbp->st_nlink;
835
836 if (ISDOT(p->fts_name))
837 return (FTS_DOT);
838
839 /*
840 * Cycle detection is done by brute force when the directory
841 * is first encountered. If the tree gets deep enough or the
842 * number of symbolic links to directories is high enough,
843 * something faster might be worthwhile.
844 */
845 for (t = p->fts_parent;
846 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
847 if (ino == t->fts_ino && dev == t->fts_dev) {
848 p->fts_cycle = t;
849 return (FTS_DC);
850 }
851 return (FTS_D);
852 }
853 if (S_ISLNK(sbp->st_mode))
854 return (FTS_SL);
855 if (S_ISREG(sbp->st_mode))
856 return (FTS_F);
857 return (FTS_DEFAULT);
858 }
859
860 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,int nitems)861 fts_sort(FTS *sp, FTSENT *head, int nitems)
862 {
863 FTSENT **ap, *p;
864
865 /*
866 * Construct an array of pointers to the structures and call qsort(3).
867 * Reassemble the array in the order returned by qsort. If unable to
868 * sort for memory reasons, return the directory entries in their
869 * current order. Allocate enough space for the current needs plus
870 * 40 so don't realloc one entry at a time.
871 */
872 if (nitems > sp->fts_nitems) {
873 struct _ftsent **a;
874
875 sp->fts_nitems = nitems + 40;
876 if ((a = realloc(sp->fts_array,
877 sp->fts_nitems * sizeof(FTSENT *))) == NULL) {
878 if (sp->fts_array)
879 free(sp->fts_array);
880 sp->fts_array = NULL;
881 sp->fts_nitems = 0;
882 return (head);
883 }
884 sp->fts_array = a;
885 }
886 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
887 *ap++ = p;
888 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar);
889 for (head = *(ap = sp->fts_array); --nitems; ++ap)
890 ap[0]->fts_link = ap[1];
891 ap[0]->fts_link = NULL;
892 return (head);
893 }
894
895 static FTSENT *
fts_alloc(FTS * sp,char * name,size_t namelen)896 fts_alloc(FTS *sp, char *name, size_t namelen)
897 {
898 FTSENT *p;
899 size_t len;
900
901 /*
902 * The file name is a variable length array and no stat structure is
903 * necessary if the user has set the nostat bit. Allocate the FTSENT
904 * structure, the file name and the stat structure in one chunk, but
905 * be careful that the stat structure is reasonably aligned. Since the
906 * fts_name field is declared to be of size 1, the fts_name pointer is
907 * namelen + 2 before the first possible address of the stat structure.
908 */
909 len = sizeof(FTSENT) + namelen;
910 if (!ISSET(FTS_NOSTAT))
911 len += sizeof(struct stat) + ALIGNBYTES;
912 if ((p = calloc(1, len)) == NULL)
913 return (NULL);
914
915 p->fts_path = sp->fts_path;
916 p->fts_namelen = namelen;
917 p->fts_instr = FTS_NOINSTR;
918 if (!ISSET(FTS_NOSTAT))
919 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2);
920 memcpy(p->fts_name, name, namelen);
921
922 return (p);
923 }
924
925 static void
fts_lfree(FTSENT * head)926 fts_lfree(FTSENT *head)
927 {
928 FTSENT *p;
929
930 /* Free a linked list of structures. */
931 while ((p = head)) {
932 head = head->fts_link;
933 free(p);
934 }
935 }
936
937 /*
938 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
939 * Most systems will allow creation of paths much longer than PATH_MAX, even
940 * though the kernel won't resolve them. Add the size (not just what's needed)
941 * plus 256 bytes so don't realloc the path 2 bytes at a time.
942 */
943 static int
fts_palloc(FTS * sp,size_t more)944 fts_palloc(FTS *sp, size_t more)
945 {
946 char *p;
947
948 /*
949 * Check for possible wraparound.
950 */
951 more += 256;
952 if (sp->fts_pathlen + more < sp->fts_pathlen) {
953 if (sp->fts_path)
954 free(sp->fts_path);
955 sp->fts_path = NULL;
956 errno = ENAMETOOLONG;
957 return (1);
958 }
959 sp->fts_pathlen += more;
960 p = realloc(sp->fts_path, sp->fts_pathlen);
961 if (p == NULL) {
962 if (sp->fts_path)
963 free(sp->fts_path);
964 sp->fts_path = NULL;
965 return (1);
966 }
967 sp->fts_path = p;
968 return (0);
969 }
970
971 /*
972 * When the path is realloc'd, have to fix all of the pointers in structures
973 * already returned.
974 */
975 static void
fts_padjust(FTS * sp,FTSENT * head)976 fts_padjust(FTS *sp, FTSENT *head)
977 {
978 FTSENT *p;
979 char *addr = sp->fts_path;
980
981 #define ADJUST(p) { \
982 if ((p)->fts_accpath != (p)->fts_name) { \
983 (p)->fts_accpath = \
984 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
985 } \
986 (p)->fts_path = addr; \
987 }
988 /* Adjust the current set of children. */
989 for (p = sp->fts_child; p; p = p->fts_link)
990 ADJUST(p);
991
992 /* Adjust the rest of the tree, including the current level. */
993 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
994 ADJUST(p);
995 p = p->fts_link ? p->fts_link : p->fts_parent;
996 }
997 }
998
999 static size_t
fts_maxarglen(char * const * argv)1000 fts_maxarglen(char * const *argv)
1001 {
1002 size_t len, max;
1003
1004 for (max = 0; *argv; ++argv)
1005 if ((len = strlen(*argv)) > max)
1006 max = len;
1007 return (max + 1);
1008 }
1009
1010 /*
1011 * Change to dir specified by fd or p->fts_accpath without getting
1012 * tricked by someone changing the world out from underneath us.
1013 * Assumes p->fts_dev and p->fts_ino are filled in.
1014 */
1015 static int
fts_safe_changedir(FTS * sp,FTSENT * p,int fd,char * path)1016 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
1017 {
1018 int ret, oerrno, newfd;
1019 struct stat sb;
1020
1021 newfd = fd;
1022 if (ISSET(FTS_NOCHDIR))
1023 return (0);
1024 if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0)
1025 return (-1);
1026 if (fstat(newfd, &sb)) {
1027 ret = -1;
1028 goto bail;
1029 }
1030 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1031 errno = ENOENT; /* disinformation */
1032 ret = -1;
1033 goto bail;
1034 }
1035 ret = fchdir(newfd);
1036 bail:
1037 oerrno = errno;
1038 if (fd < 0)
1039 (void)close(newfd);
1040 errno = oerrno;
1041 return (ret);
1042 }
1043