1 /* $OpenBSD: fts.c,v 1.48 2014/11/20 04:14:15 guenther 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, 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 void* reallocarray(void*, size_t, size_t);
58
59 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
60
61 #define CLR(opt) (sp->fts_options &= ~(opt))
62 #define ISSET(opt) (sp->fts_options & (opt))
63 #define SET(opt) (sp->fts_options |= (opt))
64
65 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
66
67 /* fts_build flags */
68 #define BCHILD 1 /* fts_children */
69 #define BNAMES 2 /* fts_children, names only */
70 #define BREAD 3 /* fts_read */
71
72 FTS *
fts_open(char * const * argv,int options,int (* compar)(const FTSENT **,const FTSENT **))73 fts_open(char * const *argv, int options,
74 int (*compar)(const FTSENT **, const FTSENT **))
75 {
76 FTS *sp;
77 FTSENT *p, *root;
78 int nitems;
79 FTSENT *parent, *tmp;
80 size_t len;
81
82 /* Options check. */
83 if (options & ~FTS_OPTIONMASK) {
84 errno = EINVAL;
85 return (NULL);
86 }
87
88 /* Allocate/initialize the stream */
89 if ((sp = calloc(1, sizeof(FTS))) == NULL)
90 return (NULL);
91 sp->fts_compar = compar;
92 sp->fts_options = options;
93
94 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
95 if (ISSET(FTS_LOGICAL))
96 SET(FTS_NOCHDIR);
97
98 /*
99 * Start out with 1K of path space, and enough, in any case,
100 * to hold the user's paths.
101 */
102 if (fts_palloc(sp, MAX(fts_maxarglen(argv), PATH_MAX)))
103 goto mem1;
104
105 /* Allocate/initialize root's parent. */
106 if ((parent = fts_alloc(sp, "", 0)) == NULL)
107 goto mem2;
108 parent->fts_level = FTS_ROOTPARENTLEVEL;
109
110 /* Allocate/initialize root(s). */
111 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
112 /* Don't allow zero-length paths. */
113 if ((len = strlen(*argv)) == 0) {
114 errno = ENOENT;
115 goto mem3;
116 }
117
118 if ((p = fts_alloc(sp, *argv, len)) == NULL)
119 goto mem3;
120 p->fts_level = FTS_ROOTLEVEL;
121 p->fts_parent = parent;
122 p->fts_accpath = p->fts_name;
123 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1);
124
125 /* Command-line "." and ".." are real directories. */
126 if (p->fts_info == FTS_DOT)
127 p->fts_info = FTS_D;
128
129 /*
130 * If comparison routine supplied, traverse in sorted
131 * order; otherwise traverse in the order specified.
132 */
133 if (compar) {
134 p->fts_link = root;
135 root = p;
136 } else {
137 p->fts_link = NULL;
138 if (root == NULL)
139 tmp = root = p;
140 else {
141 tmp->fts_link = p;
142 tmp = p;
143 }
144 }
145 }
146 if (compar && nitems > 1)
147 root = fts_sort(sp, root, nitems);
148
149 /*
150 * Allocate a dummy pointer and make fts_read think that we've just
151 * finished the node before the root(s); set p->fts_info to FTS_INIT
152 * so that everything about the "current" node is ignored.
153 */
154 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
155 goto mem3;
156 sp->fts_cur->fts_link = root;
157 sp->fts_cur->fts_info = FTS_INIT;
158
159 /*
160 * If using chdir(2), grab a file descriptor pointing to dot to ensure
161 * that we can get back here; this could be avoided for some paths,
162 * but almost certainly not worth the effort. Slashes, symbolic links,
163 * and ".." are all fairly nasty problems. Note, if we can't get the
164 * descriptor we run anyway, just more slowly.
165 */
166 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0)
167 SET(FTS_NOCHDIR);
168
169 if (nitems == 0)
170 free(parent);
171
172 return (sp);
173
174 mem3: fts_lfree(root);
175 free(parent);
176 mem2: free(sp->fts_path);
177 mem1: free(sp);
178 return (NULL);
179 }
180
181 static void
fts_load(FTS * sp,FTSENT * p)182 fts_load(FTS *sp, FTSENT *p)
183 {
184 size_t len;
185 char *cp;
186
187 /*
188 * Load the stream structure for the next traversal. Since we don't
189 * actually enter the directory until after the preorder visit, set
190 * the fts_accpath field specially so the chdir gets done to the right
191 * place and the user can access the first node. From fts_open it's
192 * known that the path will fit.
193 */
194 len = p->fts_pathlen = p->fts_namelen;
195 memmove(sp->fts_path, p->fts_name, len + 1);
196 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
197 len = strlen(++cp);
198 memmove(p->fts_name, cp, len + 1);
199 p->fts_namelen = len;
200 }
201 p->fts_accpath = p->fts_path = sp->fts_path;
202 sp->fts_dev = p->fts_dev;
203 }
204
205 int
fts_close(FTS * sp)206 fts_close(FTS *sp)
207 {
208 FTSENT *freep, *p;
209 int rfd, error = 0;
210
211 /*
212 * This still works if we haven't read anything -- the dummy structure
213 * points to the root list, so we step through to the end of the root
214 * list which has a valid parent pointer.
215 */
216 if (sp->fts_cur) {
217 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
218 freep = p;
219 p = p->fts_link ? p->fts_link : p->fts_parent;
220 free(freep);
221 }
222 free(p);
223 }
224
225 /* Stash the original directory fd if needed. */
226 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd;
227
228 /* Free up child linked list, sort array, path buffer, stream ptr.*/
229 if (sp->fts_child)
230 fts_lfree(sp->fts_child);
231 if (sp->fts_array)
232 free(sp->fts_array);
233 free(sp->fts_path);
234 free(sp);
235
236 /* Return to original directory, checking for error. */
237 if (rfd != -1) {
238 int saved_errno;
239 error = fchdir(rfd);
240 saved_errno = errno;
241 (void)close(rfd);
242 errno = saved_errno;
243 }
244
245 return (error);
246 }
247
248 /*
249 * Special case of "/" at the end of the path so that slashes aren't
250 * appended which would cause paths to be written as "....//foo".
251 */
252 #define NAPPEND(p) \
253 (p->fts_path[p->fts_pathlen - 1] == '/' \
254 ? p->fts_pathlen - 1 : p->fts_pathlen)
255
256 FTSENT *
fts_read(FTS * sp)257 fts_read(FTS *sp)
258 {
259 FTSENT *p, *tmp;
260 int instr;
261 char *t;
262 int saved_errno;
263
264 /* If finished or unrecoverable error, return NULL. */
265 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
266 return (NULL);
267
268 /* Set current node pointer. */
269 p = sp->fts_cur;
270
271 /* Save and zero out user instructions. */
272 instr = p->fts_instr;
273 p->fts_instr = FTS_NOINSTR;
274
275 /* Any type of file may be re-visited; re-stat and re-turn. */
276 if (instr == FTS_AGAIN) {
277 p->fts_info = fts_stat(sp, p, 0, -1);
278 return (p);
279 }
280
281 /*
282 * Following a symlink -- SLNONE test allows application to see
283 * SLNONE and recover. If indirecting through a symlink, have
284 * keep a pointer to current location. If unable to get that
285 * pointer, follow fails.
286 */
287 if (instr == FTS_FOLLOW &&
288 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
289 p->fts_info = fts_stat(sp, p, 1, -1);
290 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
291 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) {
292 p->fts_errno = errno;
293 p->fts_info = FTS_ERR;
294 } else
295 p->fts_flags |= FTS_SYMFOLLOW;
296 }
297 return (p);
298 }
299
300 /* Directory in pre-order. */
301 if (p->fts_info == FTS_D) {
302 /* If skipped or crossed mount point, do post-order visit. */
303 if (instr == FTS_SKIP ||
304 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
305 if (p->fts_flags & FTS_SYMFOLLOW)
306 (void)close(p->fts_symfd);
307 if (sp->fts_child) {
308 fts_lfree(sp->fts_child);
309 sp->fts_child = NULL;
310 }
311 p->fts_info = FTS_DP;
312 return (p);
313 }
314
315 /* Rebuild if only read the names and now traversing. */
316 if (sp->fts_child && ISSET(FTS_NAMEONLY)) {
317 CLR(FTS_NAMEONLY);
318 fts_lfree(sp->fts_child);
319 sp->fts_child = NULL;
320 }
321
322 /*
323 * Cd to the subdirectory.
324 *
325 * If have already read and now fail to chdir, whack the list
326 * to make the names come out right, and set the parent errno
327 * so the application will eventually get an error condition.
328 * Set the FTS_DONTCHDIR flag so that when we logically change
329 * directories back to the parent we don't do a chdir.
330 *
331 * If haven't read do so. If the read fails, fts_build sets
332 * FTS_STOP or the fts_info field of the node.
333 */
334 if (sp->fts_child) {
335 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
336 p->fts_errno = errno;
337 p->fts_flags |= FTS_DONTCHDIR;
338 for (p = sp->fts_child; p; p = p->fts_link)
339 p->fts_accpath =
340 p->fts_parent->fts_accpath;
341 }
342 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
343 if (ISSET(FTS_STOP))
344 return (NULL);
345 return (p);
346 }
347 p = sp->fts_child;
348 sp->fts_child = NULL;
349 goto name;
350 }
351
352 /* Move to the next node on this level. */
353 next: tmp = p;
354 if ((p = p->fts_link)) {
355 free(tmp);
356
357 /*
358 * If reached the top, return to the original directory (or
359 * the root of the tree), and load the paths for the next root.
360 */
361 if (p->fts_level == FTS_ROOTLEVEL) {
362 if (FCHDIR(sp, sp->fts_rfd)) {
363 SET(FTS_STOP);
364 return (NULL);
365 }
366 fts_load(sp, p);
367 return (sp->fts_cur = p);
368 }
369
370 /*
371 * User may have called fts_set on the node. If skipped,
372 * ignore. If followed, get a file descriptor so we can
373 * get back if necessary.
374 */
375 if (p->fts_instr == FTS_SKIP)
376 goto next;
377 if (p->fts_instr == FTS_FOLLOW) {
378 p->fts_info = fts_stat(sp, p, 1, -1);
379 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
380 if ((p->fts_symfd =
381 open(".", O_RDONLY, 0)) < 0) {
382 p->fts_errno = errno;
383 p->fts_info = FTS_ERR;
384 } else
385 p->fts_flags |= FTS_SYMFOLLOW;
386 }
387 p->fts_instr = FTS_NOINSTR;
388 }
389
390 name: t = sp->fts_path + NAPPEND(p->fts_parent);
391 *t++ = '/';
392 memmove(t, p->fts_name, p->fts_namelen + 1);
393 return (sp->fts_cur = p);
394 }
395
396 /* Move up to the parent node. */
397 p = tmp->fts_parent;
398 free(tmp);
399
400 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
401 /*
402 * Done; free everything up and set errno to 0 so the user
403 * can distinguish between error and EOF.
404 */
405 free(p);
406 errno = 0;
407 return (sp->fts_cur = NULL);
408 }
409
410 /* NUL terminate the pathname. */
411 sp->fts_path[p->fts_pathlen] = '\0';
412
413 /*
414 * Return to the parent directory. If at a root node or came through
415 * a symlink, go back through the file descriptor. Otherwise, cd up
416 * one directory.
417 */
418 if (p->fts_level == FTS_ROOTLEVEL) {
419 if (FCHDIR(sp, sp->fts_rfd)) {
420 SET(FTS_STOP);
421 sp->fts_cur = p;
422 return (NULL);
423 }
424 } else if (p->fts_flags & FTS_SYMFOLLOW) {
425 if (FCHDIR(sp, p->fts_symfd)) {
426 saved_errno = errno;
427 (void)close(p->fts_symfd);
428 errno = saved_errno;
429 SET(FTS_STOP);
430 sp->fts_cur = p;
431 return (NULL);
432 }
433 (void)close(p->fts_symfd);
434 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
435 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
436 SET(FTS_STOP);
437 sp->fts_cur = p;
438 return (NULL);
439 }
440 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
441 return (sp->fts_cur = p);
442 }
443
444 /*
445 * Fts_set takes the stream as an argument although it's not used in this
446 * implementation; it would be necessary if anyone wanted to add global
447 * semantics to fts using fts_set. An error return is allowed for similar
448 * reasons.
449 */
450 /* ARGSUSED */
451 int
fts_set(FTS * sp __unused,FTSENT * p,int instr)452 fts_set(FTS *sp __unused, FTSENT *p, int instr)
453 {
454 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
455 instr != FTS_NOINSTR && instr != FTS_SKIP) {
456 errno = EINVAL;
457 return (1);
458 }
459 p->fts_instr = instr;
460 return (0);
461 }
462
463 FTSENT *
fts_children(FTS * sp,int instr)464 fts_children(FTS *sp, int instr)
465 {
466 FTSENT *p;
467 int fd;
468
469 if (instr && instr != FTS_NAMEONLY) {
470 errno = EINVAL;
471 return (NULL);
472 }
473
474 /* Set current node pointer. */
475 p = sp->fts_cur;
476
477 /*
478 * Errno set to 0 so user can distinguish empty directory from
479 * an error.
480 */
481 errno = 0;
482
483 /* Fatal errors stop here. */
484 if (ISSET(FTS_STOP))
485 return (NULL);
486
487 /* Return logical hierarchy of user's arguments. */
488 if (p->fts_info == FTS_INIT)
489 return (p->fts_link);
490
491 /*
492 * If not a directory being visited in pre-order, stop here. Could
493 * allow FTS_DNR, assuming the user has fixed the problem, but the
494 * same effect is available with FTS_AGAIN.
495 */
496 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
497 return (NULL);
498
499 /* Free up any previous child list. */
500 if (sp->fts_child)
501 fts_lfree(sp->fts_child);
502
503 if (instr == FTS_NAMEONLY) {
504 SET(FTS_NAMEONLY);
505 instr = BNAMES;
506 } else
507 instr = BCHILD;
508
509 /*
510 * If using chdir on a relative path and called BEFORE fts_read does
511 * its chdir to the root of a traversal, we can lose -- we need to
512 * chdir into the subdirectory, and we don't know where the current
513 * directory is, so we can't get back so that the upcoming chdir by
514 * fts_read will work.
515 */
516 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
517 ISSET(FTS_NOCHDIR))
518 return (sp->fts_child = fts_build(sp, instr));
519
520 if ((fd = open(".", O_RDONLY, 0)) < 0)
521 return (NULL);
522 sp->fts_child = fts_build(sp, instr);
523 if (fchdir(fd)) {
524 (void)close(fd);
525 return (NULL);
526 }
527 (void)close(fd);
528 return (sp->fts_child);
529 }
530
531 /*
532 * This is the tricky part -- do not casually change *anything* in here. The
533 * idea is to build the linked list of entries that are used by fts_children
534 * and fts_read. There are lots of special cases.
535 *
536 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
537 * set and it's a physical walk (so that symbolic links can't be directories),
538 * we can do things quickly. First, if it's a 4.4BSD file system, the type
539 * of the file is in the directory entry. Otherwise, we assume that the number
540 * of subdirectories in a node is equal to the number of links to the parent.
541 * The former skips all stat calls. The latter skips stat calls in any leaf
542 * directories and for any files after the subdirectories in the directory have
543 * been found, cutting the stat calls by about 2/3.
544 */
545 static FTSENT *
fts_build(FTS * sp,int type)546 fts_build(FTS *sp, int type)
547 {
548 struct dirent *dp;
549 FTSENT *p, *head;
550 FTSENT *cur, *tail;
551 DIR *dirp;
552 void *oldaddr;
553 size_t len, maxlen;
554 int nitems, cderrno, descend, level, nlinks, nostat = 0, doadjust;
555 int saved_errno;
556 char *cp = NULL;
557
558 /* Set current node pointer. */
559 cur = sp->fts_cur;
560
561 /*
562 * Open the directory for reading. If this fails, we're done.
563 * If being called from fts_read, set the fts_info field.
564 */
565 if ((dirp = opendir(cur->fts_accpath)) == NULL) {
566 if (type == BREAD) {
567 cur->fts_info = FTS_DNR;
568 cur->fts_errno = errno;
569 }
570 return (NULL);
571 }
572
573 /*
574 * Nlinks is the number of possible entries of type directory in the
575 * directory if we're cheating on stat calls, 0 if we're not doing
576 * any stat calls at all, -1 if we're doing stats on everything.
577 */
578 if (type == BNAMES)
579 nlinks = 0;
580 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
581 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
582 nostat = 1;
583 } else {
584 nlinks = -1;
585 nostat = 0;
586 }
587
588 #ifdef notdef
589 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink);
590 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
591 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
592 #endif
593 /*
594 * If we're going to need to stat anything or we want to descend
595 * and stay in the directory, chdir. If this fails we keep going,
596 * but set a flag so we don't chdir after the post-order visit.
597 * We won't be able to stat anything, but we can still return the
598 * names themselves. Note, that since fts_read won't be able to
599 * chdir into the directory, it will have to return different path
600 * names than before, i.e. "a/b" instead of "b". Since the node
601 * has already been visited in pre-order, have to wait until the
602 * post-order visit to return the error. There is a special case
603 * here, if there was nothing to stat then it's not an error to
604 * not be able to stat. This is all fairly nasty. If a program
605 * needed sorted entries or stat information, they had better be
606 * checking FTS_NS on the returned nodes.
607 */
608 cderrno = 0;
609 if (nlinks || type == BREAD) {
610 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
611 if (nlinks && type == BREAD)
612 cur->fts_errno = errno;
613 cur->fts_flags |= FTS_DONTCHDIR;
614 descend = 0;
615 cderrno = errno;
616 (void)closedir(dirp);
617 dirp = NULL;
618 } else
619 descend = 1;
620 } else
621 descend = 0;
622
623 /*
624 * Figure out the max file name length that can be stored in the
625 * current path -- the inner loop allocates more path as necessary.
626 * We really wouldn't have to do the maxlen calculations here, we
627 * could do them in fts_read before returning the path, but it's a
628 * lot easier here since the length is part of the dirent structure.
629 *
630 * If not changing directories set a pointer so that can just append
631 * each new name into the path.
632 */
633 len = NAPPEND(cur);
634 if (ISSET(FTS_NOCHDIR)) {
635 cp = sp->fts_path + len;
636 *cp++ = '/';
637 }
638 len++;
639 maxlen = sp->fts_pathlen - len;
640
641 /*
642 * fts_level is signed so we must prevent it from wrapping
643 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
644 */
645 level = cur->fts_level;
646 if (level < FTS_MAXLEVEL)
647 level++;
648
649 /* Read the directory, attaching each entry to the `link' pointer. */
650 doadjust = 0;
651 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
652 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
653 continue;
654
655 if (!(p = fts_alloc(sp, dp->d_name, strlen(dp->d_name))))
656 goto mem1;
657 if (strlen(dp->d_name) >= maxlen) { /* include space for NUL */
658 oldaddr = sp->fts_path;
659 if (fts_palloc(sp, strlen(dp->d_name) +len + 1)) {
660 /*
661 * No more memory for path or structures. Save
662 * errno, free up the current structure and the
663 * structures already allocated.
664 */
665 mem1: saved_errno = errno;
666 if (p)
667 free(p);
668 fts_lfree(head);
669 (void)closedir(dirp);
670 cur->fts_info = FTS_ERR;
671 SET(FTS_STOP);
672 errno = saved_errno;
673 return (NULL);
674 }
675 /* Did realloc() change the pointer? */
676 if (oldaddr != sp->fts_path) {
677 doadjust = 1;
678 if (ISSET(FTS_NOCHDIR))
679 cp = sp->fts_path + len;
680 }
681 maxlen = sp->fts_pathlen - len;
682 }
683
684 p->fts_level = level;
685 p->fts_parent = sp->fts_cur;
686 p->fts_pathlen = len + strlen(dp->d_name);
687 if (p->fts_pathlen < len) {
688 /*
689 * If we wrap, free up the current structure and
690 * the structures already allocated, then error
691 * out with ENAMETOOLONG.
692 */
693 free(p);
694 fts_lfree(head);
695 (void)closedir(dirp);
696 cur->fts_info = FTS_ERR;
697 SET(FTS_STOP);
698 errno = ENAMETOOLONG;
699 return (NULL);
700 }
701
702 if (cderrno) {
703 if (nlinks) {
704 p->fts_info = FTS_NS;
705 p->fts_errno = cderrno;
706 } else
707 p->fts_info = FTS_NSOK;
708 p->fts_accpath = cur->fts_accpath;
709 } else if (nlinks == 0
710 #ifdef DT_DIR
711 || (nostat &&
712 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
713 #endif
714 ) {
715 p->fts_accpath =
716 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
717 p->fts_info = FTS_NSOK;
718 } else {
719 /* Build a file name for fts_stat to stat. */
720 if (ISSET(FTS_NOCHDIR)) {
721 p->fts_accpath = p->fts_path;
722 memmove(cp, p->fts_name, p->fts_namelen + 1);
723 p->fts_info = fts_stat(sp, p, 0, dirfd(dirp));
724 } else {
725 p->fts_accpath = p->fts_name;
726 p->fts_info = fts_stat(sp, p, 0, -1);
727 }
728
729 /* Decrement link count if applicable. */
730 if (nlinks > 0 && (p->fts_info == FTS_D ||
731 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
732 --nlinks;
733 }
734
735 /* We walk in directory order so "ls -f" doesn't get upset. */
736 p->fts_link = NULL;
737 if (head == NULL)
738 head = tail = p;
739 else {
740 tail->fts_link = p;
741 tail = p;
742 }
743 ++nitems;
744 }
745 if (dirp)
746 (void)closedir(dirp);
747
748 /*
749 * If realloc() changed the address of the path, adjust the
750 * addresses for the rest of the tree and the dir list.
751 */
752 if (doadjust)
753 fts_padjust(sp, head);
754
755 /*
756 * If not changing directories, reset the path back to original
757 * state.
758 */
759 if (ISSET(FTS_NOCHDIR)) {
760 if (len == sp->fts_pathlen || nitems == 0)
761 --cp;
762 *cp = '\0';
763 }
764
765 /*
766 * If descended after called from fts_children or after called from
767 * fts_read and nothing found, get back. At the root level we use
768 * the saved fd; if one of fts_open()'s arguments is a relative path
769 * to an empty directory, we wind up here with no other way back. If
770 * can't get back, we're done.
771 */
772 if (descend && (type == BCHILD || !nitems) &&
773 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) :
774 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
775 cur->fts_info = FTS_ERR;
776 SET(FTS_STOP);
777 return (NULL);
778 }
779
780 /* If didn't find anything, return NULL. */
781 if (!nitems) {
782 if (type == BREAD)
783 cur->fts_info = FTS_DP;
784 return (NULL);
785 }
786
787 /* Sort the entries. */
788 if (sp->fts_compar && nitems > 1)
789 head = fts_sort(sp, head, nitems);
790 return (head);
791 }
792
793 static u_short
fts_stat(FTS * sp,FTSENT * p,int follow,int dfd)794 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd)
795 {
796 FTSENT *t;
797 dev_t dev;
798 ino_t ino;
799 struct stat *sbp, sb;
800 int saved_errno;
801 const char *path;
802
803 if (dfd == -1) {
804 path = p->fts_accpath;
805 dfd = AT_FDCWD;
806 } else
807 path = p->fts_name;
808
809 /* If user needs stat info, stat buffer already allocated. */
810 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
811
812 /*
813 * If doing a logical walk, or application requested FTS_FOLLOW, do
814 * a stat(2). If that fails, check for a non-existent symlink. If
815 * fail, set the errno from the stat call.
816 */
817 if (ISSET(FTS_LOGICAL) || follow) {
818 if (fstatat(dfd, path, sbp, 0)) {
819 saved_errno = errno;
820 if (!fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) {
821 errno = 0;
822 return (FTS_SLNONE);
823 }
824 p->fts_errno = saved_errno;
825 goto err;
826 }
827 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) {
828 p->fts_errno = errno;
829 err: memset(sbp, 0, sizeof(struct stat));
830 return (FTS_NS);
831 }
832
833 if (S_ISDIR(sbp->st_mode)) {
834 /*
835 * Set the device/inode. Used to find cycles and check for
836 * crossing mount points. Also remember the link count, used
837 * in fts_build to limit the number of stat calls. It is
838 * understood that these fields are only referenced if fts_info
839 * is set to FTS_D.
840 */
841 dev = p->fts_dev = sbp->st_dev;
842 ino = p->fts_ino = sbp->st_ino;
843 p->fts_nlink = sbp->st_nlink;
844
845 if (ISDOT(p->fts_name))
846 return (FTS_DOT);
847
848 /*
849 * Cycle detection is done by brute force when the directory
850 * is first encountered. If the tree gets deep enough or the
851 * number of symbolic links to directories is high enough,
852 * something faster might be worthwhile.
853 */
854 for (t = p->fts_parent;
855 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
856 if (ino == t->fts_ino && dev == t->fts_dev) {
857 p->fts_cycle = t;
858 return (FTS_DC);
859 }
860 return (FTS_D);
861 }
862 if (S_ISLNK(sbp->st_mode))
863 return (FTS_SL);
864 if (S_ISREG(sbp->st_mode))
865 return (FTS_F);
866 return (FTS_DEFAULT);
867 }
868
869 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,int nitems)870 fts_sort(FTS *sp, FTSENT *head, int nitems)
871 {
872 FTSENT **ap, *p;
873
874 /*
875 * Construct an array of pointers to the structures and call qsort(3).
876 * Reassemble the array in the order returned by qsort. If unable to
877 * sort for memory reasons, return the directory entries in their
878 * current order. Allocate enough space for the current needs plus
879 * 40 so don't realloc one entry at a time.
880 */
881 if (nitems > sp->fts_nitems) {
882 struct _ftsent **a;
883
884 sp->fts_nitems = nitems + 40;
885 if ((a = reallocarray(sp->fts_array,
886 sp->fts_nitems, sizeof(FTSENT *))) == NULL) {
887 if (sp->fts_array)
888 free(sp->fts_array);
889 sp->fts_array = NULL;
890 sp->fts_nitems = 0;
891 return (head);
892 }
893 sp->fts_array = a;
894 }
895 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
896 *ap++ = p;
897 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar);
898 for (head = *(ap = sp->fts_array); --nitems; ++ap)
899 ap[0]->fts_link = ap[1];
900 ap[0]->fts_link = NULL;
901 return (head);
902 }
903
904 static FTSENT *
fts_alloc(FTS * sp,char * name,size_t namelen)905 fts_alloc(FTS *sp, char *name, size_t namelen)
906 {
907 FTSENT *p;
908 size_t len;
909
910 /*
911 * The file name is a variable length array and no stat structure is
912 * necessary if the user has set the nostat bit. Allocate the FTSENT
913 * structure, the file name and the stat structure in one chunk, but
914 * be careful that the stat structure is reasonably aligned. Since the
915 * fts_name field is declared to be of size 1, the fts_name pointer is
916 * namelen + 2 before the first possible address of the stat structure.
917 */
918 len = sizeof(FTSENT) + namelen;
919 if (!ISSET(FTS_NOSTAT))
920 len += sizeof(struct stat) + ALIGNBYTES;
921 if ((p = calloc(1, len)) == NULL)
922 return (NULL);
923
924 p->fts_path = sp->fts_path;
925 p->fts_namelen = namelen;
926 p->fts_instr = FTS_NOINSTR;
927 if (!ISSET(FTS_NOSTAT))
928 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2);
929 memcpy(p->fts_name, name, namelen);
930
931 return (p);
932 }
933
934 static void
fts_lfree(FTSENT * head)935 fts_lfree(FTSENT *head)
936 {
937 FTSENT *p;
938
939 /* Free a linked list of structures. */
940 while ((p = head)) {
941 head = head->fts_link;
942 free(p);
943 }
944 }
945
946 /*
947 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
948 * Most systems will allow creation of paths much longer than PATH_MAX, even
949 * though the kernel won't resolve them. Add the size (not just what's needed)
950 * plus 256 bytes so don't realloc the path 2 bytes at a time.
951 */
952 static int
fts_palloc(FTS * sp,size_t more)953 fts_palloc(FTS *sp, size_t more)
954 {
955 char *p;
956
957 /*
958 * Check for possible wraparound.
959 */
960 more += 256;
961 if (sp->fts_pathlen + more < sp->fts_pathlen) {
962 if (sp->fts_path)
963 free(sp->fts_path);
964 sp->fts_path = NULL;
965 errno = ENAMETOOLONG;
966 return (1);
967 }
968 sp->fts_pathlen += more;
969 p = realloc(sp->fts_path, sp->fts_pathlen);
970 if (p == NULL) {
971 if (sp->fts_path)
972 free(sp->fts_path);
973 sp->fts_path = NULL;
974 return (1);
975 }
976 sp->fts_path = p;
977 return (0);
978 }
979
980 /*
981 * When the path is realloc'd, have to fix all of the pointers in structures
982 * already returned.
983 */
984 static void
fts_padjust(FTS * sp,FTSENT * head)985 fts_padjust(FTS *sp, FTSENT *head)
986 {
987 FTSENT *p;
988 char *addr = sp->fts_path;
989
990 #define ADJUST(p) { \
991 if ((p)->fts_accpath != (p)->fts_name) { \
992 (p)->fts_accpath = \
993 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
994 } \
995 (p)->fts_path = addr; \
996 }
997 /* Adjust the current set of children. */
998 for (p = sp->fts_child; p; p = p->fts_link)
999 ADJUST(p);
1000
1001 /* Adjust the rest of the tree, including the current level. */
1002 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1003 ADJUST(p);
1004 p = p->fts_link ? p->fts_link : p->fts_parent;
1005 }
1006 }
1007
1008 static size_t
fts_maxarglen(char * const * argv)1009 fts_maxarglen(char * const *argv)
1010 {
1011 size_t len, max;
1012
1013 for (max = 0; *argv; ++argv)
1014 if ((len = strlen(*argv)) > max)
1015 max = len;
1016 return (max + 1);
1017 }
1018
1019 /*
1020 * Change to dir specified by fd or p->fts_accpath without getting
1021 * tricked by someone changing the world out from underneath us.
1022 * Assumes p->fts_dev and p->fts_ino are filled in.
1023 */
1024 static int
fts_safe_changedir(FTS * sp,FTSENT * p,int fd,char * path)1025 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
1026 {
1027 int ret, oerrno, newfd;
1028 struct stat sb;
1029
1030 newfd = fd;
1031 if (ISSET(FTS_NOCHDIR))
1032 return (0);
1033 if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0)
1034 return (-1);
1035 if (fstat(newfd, &sb)) {
1036 ret = -1;
1037 goto bail;
1038 }
1039 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1040 errno = ENOENT; /* disinformation */
1041 ret = -1;
1042 goto bail;
1043 }
1044 ret = fchdir(newfd);
1045 bail:
1046 oerrno = errno;
1047 if (fd < 0)
1048 (void)close(newfd);
1049 errno = oerrno;
1050 return (ret);
1051 }
1052