1 /* $NetBSD: fts.c,v 1.48 2015/01/29 15:55:21 manu 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 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94";
40 #else
41 __RCSID("$NetBSD: fts.c,v 1.48 2015/01/29 15:55:21 manu Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44
45 #include "namespace.h"
46 #include <sys/param.h>
47 #include <sys/stat.h>
48
49 #include <assert.h>
50 #include <dirent.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <fts.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57
58 #if ! HAVE_NBTOOL_CONFIG_H
59 #define HAVE_STRUCT_DIRENT_D_NAMLEN
60 #endif
61
62 static FTSENT *fts_alloc(FTS *, const char *, size_t);
63 static FTSENT *fts_build(FTS *, int);
64 static void fts_free(FTSENT *);
65 static void fts_lfree(FTSENT *);
66 static void fts_load(FTS *, FTSENT *);
67 static size_t fts_maxarglen(char * const *);
68 static size_t fts_pow2(size_t);
69 static int fts_palloc(FTS *, size_t);
70 static void fts_padjust(FTS *, FTSENT *);
71 static FTSENT *fts_sort(FTS *, FTSENT *, size_t);
72 static unsigned short fts_stat(FTS *, FTSENT *, int);
73 static int fts_safe_changedir(const FTS *, const FTSENT *, int,
74 const char *);
75
76 #if defined(ALIGNBYTES) && defined(ALIGN)
77 #define FTS_ALLOC_ALIGNED 1
78 #else
79 #undef FTS_ALLOC_ALIGNED
80 #endif
81
82 #ifndef ftsent_namelen_truncate
83 #define ftsent_namelen_truncate(a) \
84 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a))
85 #endif
86 #ifndef ftsent_pathlen_truncate
87 #define ftsent_pathlen_truncate(a) \
88 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a))
89 #endif
90 #ifndef fts_pathlen_truncate
91 #define fts_pathlen_truncate(a) \
92 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a))
93 #endif
94 #ifndef fts_nitems_truncate
95 #define fts_nitems_truncate(a) \
96 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a))
97 #endif
98
99 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
100
101 #define CLR(opt) (sp->fts_options &= ~(opt))
102 #define ISSET(opt) (sp->fts_options & (opt))
103 #define SET(opt) (sp->fts_options |= (opt))
104
105 #define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path))
106 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
107
108 /* fts_build flags */
109 #define BCHILD 1 /* fts_children */
110 #define BNAMES 2 /* fts_children, names only */
111 #define BREAD 3 /* fts_read */
112
113 #ifndef DTF_HIDEW
114 #undef FTS_WHITEOUT
115 #endif
116
117 FTS *
fts_open(char * const * argv,int options,int (* compar)(const FTSENT **,const FTSENT **))118 fts_open(char * const *argv, int options,
119 int (*compar)(const FTSENT **, const FTSENT **))
120 {
121 FTS *sp;
122 FTSENT *p, *root;
123 size_t nitems;
124 FTSENT *parent, *tmp = NULL; /* pacify gcc */
125 size_t len;
126
127 _DIAGASSERT(argv != NULL);
128
129 /* Options check. */
130 if (options & ~FTS_OPTIONMASK) {
131 errno = EINVAL;
132 return (NULL);
133 }
134
135 /* Allocate/initialize the stream */
136 if ((sp = malloc(sizeof(FTS))) == NULL)
137 return (NULL);
138 memset(sp, 0, sizeof(FTS));
139 sp->fts_compar = compar;
140 sp->fts_options = options;
141
142 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
143 if (ISSET(FTS_LOGICAL))
144 SET(FTS_NOCHDIR);
145
146 /*
147 * Start out with 1K of path space, and enough, in any case,
148 * to hold the user's paths.
149 */
150 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
151 goto mem1;
152
153 /* Allocate/initialize root's parent. */
154 if ((parent = fts_alloc(sp, "", 0)) == NULL)
155 goto mem2;
156 parent->fts_level = FTS_ROOTPARENTLEVEL;
157
158 /* Allocate/initialize root(s). */
159 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
160 /* Don't allow zero-length paths. */
161 if ((len = strlen(*argv)) == 0) {
162 errno = ENOENT;
163 goto mem3;
164 }
165
166 if ((p = fts_alloc(sp, *argv, len)) == NULL)
167 goto mem3;
168 p->fts_level = FTS_ROOTLEVEL;
169 p->fts_parent = parent;
170 p->fts_accpath = p->fts_name;
171 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
172
173 /* Command-line "." and ".." are real directories. */
174 if (p->fts_info == FTS_DOT)
175 p->fts_info = FTS_D;
176
177 /*
178 * If comparison routine supplied, traverse in sorted
179 * order; otherwise traverse in the order specified.
180 */
181 if (compar) {
182 p->fts_link = root;
183 root = p;
184 } else {
185 p->fts_link = NULL;
186 if (root == NULL)
187 tmp = root = p;
188 else {
189 tmp->fts_link = p;
190 tmp = p;
191 }
192 }
193 }
194 if (compar && nitems > 1)
195 root = fts_sort(sp, root, nitems);
196
197 /*
198 * Allocate a dummy pointer and make fts_read think that we've just
199 * finished the node before the root(s); set p->fts_info to FTS_INIT
200 * so that everything about the "current" node is ignored.
201 */
202 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
203 goto mem3;
204 sp->fts_cur->fts_link = root;
205 sp->fts_cur->fts_info = FTS_INIT;
206
207 /*
208 * If using chdir(2), grab a file descriptor pointing to dot to ensure
209 * that we can get back here; this could be avoided for some paths,
210 * but almost certainly not worth the effort. Slashes, symbolic links,
211 * and ".." are all fairly nasty problems. Note, if we can't get the
212 * descriptor we run anyway, just more slowly.
213 */
214 #ifndef O_CLOEXEC
215 #define O_CLOEXEC 0
216 #endif
217 if (!ISSET(FTS_NOCHDIR)) {
218 if ((sp->fts_rfd = open(".", O_RDONLY | O_CLOEXEC, 0)) == -1)
219 SET(FTS_NOCHDIR);
220 }
221
222 if (nitems == 0)
223 fts_free(parent);
224
225 return (sp);
226
227 mem3: fts_lfree(root);
228 fts_free(parent);
229 mem2: free(sp->fts_path);
230 mem1: free(sp);
231 return (NULL);
232 }
233
234 static void
fts_load(FTS * sp,FTSENT * p)235 fts_load(FTS *sp, FTSENT *p)
236 {
237 size_t len;
238 char *cp;
239
240 _DIAGASSERT(sp != NULL);
241 _DIAGASSERT(p != NULL);
242
243 /*
244 * Load the stream structure for the next traversal. Since we don't
245 * actually enter the directory until after the preorder visit, set
246 * the fts_accpath field specially so the chdir gets done to the right
247 * place and the user can access the first node. From fts_open it's
248 * known that the path will fit.
249 */
250 len = p->fts_pathlen = p->fts_namelen;
251 memmove(sp->fts_path, p->fts_name, len + 1);
252 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
253 len = strlen(++cp);
254 memmove(p->fts_name, cp, len + 1);
255 p->fts_namelen = ftsent_namelen_truncate(len);
256 }
257 p->fts_accpath = p->fts_path = sp->fts_path;
258 sp->fts_dev = p->fts_dev;
259 }
260
261 int
fts_close(FTS * sp)262 fts_close(FTS *sp)
263 {
264 FTSENT *freep, *p;
265 int saved_errno = 0;
266
267 _DIAGASSERT(sp != NULL);
268
269 /*
270 * This still works if we haven't read anything -- the dummy structure
271 * points to the root list, so we step through to the end of the root
272 * list which has a valid parent pointer.
273 */
274 if (sp->fts_cur) {
275 if (sp->fts_cur->fts_flags & FTS_SYMFOLLOW)
276 (void)close(sp->fts_cur->fts_symfd);
277 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
278 freep = p;
279 p = p->fts_link ? p->fts_link : p->fts_parent;
280 fts_free(freep);
281 }
282 fts_free(p);
283 }
284
285 /* Free up child linked list, sort array, path buffer. */
286 if (sp->fts_child)
287 fts_lfree(sp->fts_child);
288 if (sp->fts_array)
289 free(sp->fts_array);
290 free(sp->fts_path);
291
292 /* Return to original directory, save errno if necessary. */
293 if (!ISSET(FTS_NOCHDIR)) {
294 if (fchdir(sp->fts_rfd) == -1)
295 saved_errno = errno;
296 (void)close(sp->fts_rfd);
297 }
298
299 /* Free up the stream pointer. */
300 free(sp);
301 if (saved_errno) {
302 errno = saved_errno;
303 return -1;
304 }
305
306 return 0;
307 }
308
309 #if !defined(__FTS_COMPAT_TAILINGSLASH)
310
311 /*
312 * Special case of "/" at the end of the path so that slashes aren't
313 * appended which would cause paths to be written as "....//foo".
314 */
315 #define NAPPEND(p) \
316 (p->fts_path[p->fts_pathlen - 1] == '/' \
317 ? p->fts_pathlen - 1 : p->fts_pathlen)
318
319 #else /* !defined(__FTS_COMPAT_TAILINGSLASH) */
320
321 /*
322 * compatibility with the old behaviour.
323 *
324 * Special case a root of "/" so that slashes aren't appended which would
325 * cause paths to be written as "//foo".
326 */
327
328 #define NAPPEND(p) \
329 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \
330 p->fts_path[0] == '/' ? 0 : p->fts_pathlen)
331
332 #endif /* !defined(__FTS_COMPAT_TAILINGSLASH) */
333
334 FTSENT *
fts_read(FTS * sp)335 fts_read(FTS *sp)
336 {
337 FTSENT *p, *tmp;
338 int instr;
339 char *t;
340 int saved_errno;
341
342 _DIAGASSERT(sp != NULL);
343
344 /* If finished or unrecoverable error, return NULL. */
345 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
346 return (NULL);
347
348 /* Set current node pointer. */
349 p = sp->fts_cur;
350
351 /* Save and zero out user instructions. */
352 instr = p->fts_instr;
353 p->fts_instr = FTS_NOINSTR;
354
355 /* Any type of file may be re-visited; re-stat and re-turn. */
356 if (instr == FTS_AGAIN) {
357 p->fts_info = fts_stat(sp, p, 0);
358 return (p);
359 }
360
361 /*
362 * Following a symlink -- SLNONE test allows application to see
363 * SLNONE and recover. If indirecting through a symlink, have
364 * keep a pointer to current location. If unable to get that
365 * pointer, follow fails.
366 */
367 if (instr == FTS_FOLLOW &&
368 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
369 p->fts_info = fts_stat(sp, p, 1);
370 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
371 if ((p->fts_symfd = open(".", O_RDONLY | O_CLOEXEC, 0))
372 == -1) {
373 p->fts_errno = errno;
374 p->fts_info = FTS_ERR;
375 } else
376 p->fts_flags |= FTS_SYMFOLLOW;
377 }
378 return (p);
379 }
380
381 /* Directory in pre-order. */
382 if (p->fts_info == FTS_D) {
383 /* If skipped or crossed mount point, do post-order visit. */
384 if (instr == FTS_SKIP ||
385 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
386 if (p->fts_flags & FTS_SYMFOLLOW)
387 (void)close(p->fts_symfd);
388 if (sp->fts_child) {
389 fts_lfree(sp->fts_child);
390 sp->fts_child = NULL;
391 }
392 p->fts_info = FTS_DP;
393 return (p);
394 }
395
396 /* Rebuild if only read the names and now traversing. */
397 if (sp->fts_child && ISSET(FTS_NAMEONLY)) {
398 CLR(FTS_NAMEONLY);
399 fts_lfree(sp->fts_child);
400 sp->fts_child = NULL;
401 }
402
403 /*
404 * Cd to the subdirectory.
405 *
406 * If have already read and now fail to chdir, whack the list
407 * to make the names come out right, and set the parent errno
408 * so the application will eventually get an error condition.
409 * Set the FTS_DONTCHDIR flag so that when we logically change
410 * directories back to the parent we don't do a chdir.
411 *
412 * If haven't read do so. If the read fails, fts_build sets
413 * FTS_STOP or the fts_info field of the node.
414 */
415 if (sp->fts_child) {
416 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
417 p->fts_errno = errno;
418 p->fts_flags |= FTS_DONTCHDIR;
419 for (p = sp->fts_child; p; p = p->fts_link)
420 p->fts_accpath =
421 p->fts_parent->fts_accpath;
422 }
423 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
424 if (ISSET(FTS_STOP))
425 return (NULL);
426 return (p);
427 }
428 p = sp->fts_child;
429 sp->fts_child = NULL;
430 goto name;
431 }
432
433 next:
434 /* Move to the next node on this level. */
435 tmp = p;
436
437 /*
438 * We are going to free sp->fts_cur, set it to NULL so
439 * that fts_close() does not attempt to free it again
440 * if we exit without setting it to a new value because
441 * FCHDIR() failed below.
442 */
443 assert(tmp == sp->fts_cur);
444 sp->fts_cur = NULL;
445
446 if ((p = p->fts_link) != NULL) {
447 fts_free(tmp);
448
449 /*
450 * If reached the top, return to the original directory, and
451 * load the paths for the next root.
452 */
453 if (p->fts_level == FTS_ROOTLEVEL) {
454 if (FCHDIR(sp, sp->fts_rfd)) {
455 SET(FTS_STOP);
456 return (NULL);
457 }
458 fts_load(sp, p);
459 return (sp->fts_cur = p);
460 }
461
462 /*
463 * User may have called fts_set on the node. If skipped,
464 * ignore. If followed, get a file descriptor so we can
465 * get back if necessary.
466 */
467 if (p->fts_instr == FTS_SKIP)
468 goto next;
469 if (p->fts_instr == FTS_FOLLOW) {
470 p->fts_info = fts_stat(sp, p, 1);
471 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
472 if ((p->fts_symfd =
473 open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) {
474 p->fts_errno = errno;
475 p->fts_info = FTS_ERR;
476 } else
477 p->fts_flags |= FTS_SYMFOLLOW;
478 }
479 p->fts_instr = FTS_NOINSTR;
480 }
481
482 name: t = sp->fts_path + NAPPEND(p->fts_parent);
483 *t++ = '/';
484 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1));
485 return (sp->fts_cur = p);
486 }
487
488 /* Move up to the parent node. */
489 p = tmp->fts_parent;
490 fts_free(tmp);
491
492 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
493 /*
494 * Done; free everything up and set errno to 0 so the user
495 * can distinguish between error and EOF.
496 */
497 fts_free(p);
498 errno = 0;
499 return (sp->fts_cur = NULL);
500 }
501
502 /* NUL terminate the pathname. */
503 sp->fts_path[p->fts_pathlen] = '\0';
504
505 /*
506 * Return to the parent directory. If at a root node or came through
507 * a symlink, go back through the file descriptor. Otherwise, cd up
508 * one directory.
509 */
510 if (p->fts_level == FTS_ROOTLEVEL) {
511 if (FCHDIR(sp, sp->fts_rfd)) {
512 SET(FTS_STOP);
513 return (NULL);
514 }
515 } else if (p->fts_flags & FTS_SYMFOLLOW) {
516 if (FCHDIR(sp, p->fts_symfd)) {
517 saved_errno = errno;
518 (void)close(p->fts_symfd);
519 errno = saved_errno;
520 SET(FTS_STOP);
521 return (NULL);
522 }
523 (void)close(p->fts_symfd);
524 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
525 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
526 SET(FTS_STOP);
527 return (NULL);
528 }
529 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
530 return (sp->fts_cur = p);
531 }
532
533 /*
534 * Fts_set takes the stream as an argument although it's not used in this
535 * implementation; it would be necessary if anyone wanted to add global
536 * semantics to fts using fts_set. An error return is allowed for similar
537 * reasons.
538 */
539 /* ARGSUSED */
540 int
fts_set(FTS * sp,FTSENT * p,int instr)541 fts_set(FTS *sp, FTSENT *p, int instr)
542 {
543
544 _DIAGASSERT(sp != NULL);
545 _DIAGASSERT(p != NULL);
546
547 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
548 instr != FTS_NOINSTR && instr != FTS_SKIP) {
549 errno = EINVAL;
550 return (1);
551 }
552 p->fts_instr = instr;
553 return (0);
554 }
555
556 FTSENT *
fts_children(FTS * sp,int instr)557 fts_children(FTS *sp, int instr)
558 {
559 FTSENT *p;
560 int fd;
561
562 _DIAGASSERT(sp != NULL);
563
564 if (instr && instr != FTS_NAMEONLY) {
565 errno = EINVAL;
566 return (NULL);
567 }
568
569 /* Set current node pointer. */
570 p = sp->fts_cur;
571
572 /*
573 * Errno set to 0 so user can distinguish empty directory from
574 * an error.
575 */
576 errno = 0;
577
578 /* Fatal errors stop here. */
579 if (ISSET(FTS_STOP))
580 return (NULL);
581
582 /* Return logical hierarchy of user's arguments. */
583 if (p->fts_info == FTS_INIT)
584 return (p->fts_link);
585
586 /*
587 * If not a directory being visited in pre-order, stop here. Could
588 * allow FTS_DNR, assuming the user has fixed the problem, but the
589 * same effect is available with FTS_AGAIN.
590 */
591 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
592 return (NULL);
593
594 /* Free up any previous child list. */
595 if (sp->fts_child)
596 fts_lfree(sp->fts_child);
597
598 if (instr == FTS_NAMEONLY) {
599 SET(FTS_NAMEONLY);
600 instr = BNAMES;
601 } else
602 instr = BCHILD;
603
604 /*
605 * If using chdir on a relative path and called BEFORE fts_read does
606 * its chdir to the root of a traversal, we can lose -- we need to
607 * chdir into the subdirectory, and we don't know where the current
608 * directory is, so we can't get back so that the upcoming chdir by
609 * fts_read will work.
610 */
611 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
612 ISSET(FTS_NOCHDIR))
613 return (sp->fts_child = fts_build(sp, instr));
614
615 if ((fd = open(".", O_RDONLY | O_CLOEXEC, 0)) == -1)
616 return (sp->fts_child = NULL);
617 sp->fts_child = fts_build(sp, instr);
618 if (fchdir(fd)) {
619 (void)close(fd);
620 return (NULL);
621 }
622 (void)close(fd);
623 return (sp->fts_child);
624 }
625
626 /*
627 * This is the tricky part -- do not casually change *anything* in here. The
628 * idea is to build the linked list of entries that are used by fts_children
629 * and fts_read. There are lots of special cases.
630 *
631 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
632 * set and it's a physical walk (so that symbolic links can't be directories),
633 * we can do things quickly. First, if it's a 4.4BSD file system, the type
634 * of the file is in the directory entry. Otherwise, we assume that the number
635 * of subdirectories in a node is equal to the number of links to the parent.
636 * The former skips all stat calls. The latter skips stat calls in any leaf
637 * directories and for any files after the subdirectories in the directory have
638 * been found, cutting the stat calls by about 2/3.
639 */
640 static FTSENT *
fts_build(FTS * sp,int type)641 fts_build(FTS *sp, int type)
642 {
643 struct dirent *dp;
644 FTSENT *p, *head;
645 size_t nitems;
646 FTSENT *cur, *tail;
647 DIR *dirp;
648 void *oldaddr;
649 size_t dnamlen;
650 int cderrno, descend, level, nlinks, saved_errno, nostat, doadjust;
651 size_t len, maxlen;
652 #ifdef FTS_WHITEOUT
653 int oflag;
654 #endif
655 char *cp = NULL; /* pacify gcc */
656
657 _DIAGASSERT(sp != NULL);
658
659 /* Set current node pointer. */
660 cur = sp->fts_cur;
661
662 /*
663 * Open the directory for reading. If this fails, we're done.
664 * If being called from fts_read, set the fts_info field.
665 */
666 #ifdef FTS_WHITEOUT
667 if (ISSET(FTS_WHITEOUT))
668 oflag = DTF_NODUP|DTF_REWIND;
669 else
670 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND;
671 #else
672 #define __opendir2(path, flag) opendir(path)
673 #endif
674 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
675 if (type == BREAD) {
676 cur->fts_info = FTS_DNR;
677 cur->fts_errno = errno;
678 }
679 return (NULL);
680 }
681
682 /*
683 * Nlinks is the number of possible entries of type directory in the
684 * directory if we're cheating on stat calls, 0 if we're not doing
685 * any stat calls at all, -1 if we're doing stats on everything.
686 */
687 if (type == BNAMES) {
688 nlinks = 0;
689 nostat = 1;
690 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
691 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
692 nostat = 1;
693 } else {
694 nlinks = -1;
695 nostat = 0;
696 }
697
698 #ifdef notdef
699 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
700 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
701 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
702 #endif
703 /*
704 * If we're going to need to stat anything or we want to descend
705 * and stay in the directory, chdir. If this fails we keep going,
706 * but set a flag so we don't chdir after the post-order visit.
707 * We won't be able to stat anything, but we can still return the
708 * names themselves. Note, that since fts_read won't be able to
709 * chdir into the directory, it will have to return different path
710 * names than before, i.e. "a/b" instead of "b". Since the node
711 * has already been visited in pre-order, have to wait until the
712 * post-order visit to return the error. There is a special case
713 * here, if there was nothing to stat then it's not an error to
714 * not be able to stat. This is all fairly nasty. If a program
715 * needed sorted entries or stat information, they had better be
716 * checking FTS_NS on the returned nodes.
717 */
718 cderrno = 0;
719 if (nlinks || type == BREAD) {
720 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
721 if (nlinks && type == BREAD)
722 cur->fts_errno = errno;
723 cur->fts_flags |= FTS_DONTCHDIR;
724 descend = 0;
725 cderrno = errno;
726 } else
727 descend = 1;
728 } else
729 descend = 0;
730
731 /*
732 * Figure out the max file name length that can be stored in the
733 * current path -- the inner loop allocates more path as necessary.
734 * We really wouldn't have to do the maxlen calculations here, we
735 * could do them in fts_read before returning the path, but it's a
736 * lot easier here since the length is part of the dirent structure.
737 *
738 * If not changing directories set a pointer so that can just append
739 * each new name into the path.
740 */
741 len = NAPPEND(cur);
742 if (ISSET(FTS_NOCHDIR)) {
743 cp = sp->fts_path + len;
744 *cp++ = '/';
745 }
746 len++;
747 maxlen = sp->fts_pathlen - len;
748
749 #if defined(__FTS_COMPAT_LEVEL)
750 if (cur->fts_level == SHRT_MAX) {
751 (void)closedir(dirp);
752 cur->fts_info = FTS_ERR;
753 SET(FTS_STOP);
754 errno = ENAMETOOLONG;
755 return (NULL);
756 }
757 #endif
758
759 level = cur->fts_level + 1;
760
761 /* Read the directory, attaching each entry to the `link' pointer. */
762 doadjust = 0;
763 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) {
764
765 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
766 continue;
767
768 #if defined(HAVE_STRUCT_DIRENT_D_NAMLEN)
769 dnamlen = dp->d_namlen;
770 #else
771 dnamlen = strlen(dp->d_name);
772 #endif
773 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL)
774 goto mem1;
775 if (dnamlen >= maxlen) { /* include space for NUL */
776 oldaddr = sp->fts_path;
777 if (fts_palloc(sp, dnamlen + len + 1)) {
778 /*
779 * No more memory for path or structures. Save
780 * errno, free up the current structure and the
781 * structures already allocated.
782 */
783 mem1: saved_errno = errno;
784 if (p)
785 fts_free(p);
786 fts_lfree(head);
787 (void)closedir(dirp);
788 errno = saved_errno;
789 cur->fts_info = FTS_ERR;
790 SET(FTS_STOP);
791 return (NULL);
792 }
793 /* Did realloc() change the pointer? */
794 if (oldaddr != sp->fts_path) {
795 doadjust = 1;
796 if (ISSET(FTS_NOCHDIR))
797 cp = sp->fts_path + len;
798 }
799 maxlen = sp->fts_pathlen - len;
800 }
801
802 #if defined(__FTS_COMPAT_LENGTH)
803 if (len + dnamlen >= USHRT_MAX) {
804 /*
805 * In an FTSENT, fts_pathlen is an unsigned short
806 * so it is possible to wraparound here.
807 * If we do, free up the current structure and the
808 * structures already allocated, then error out
809 * with ENAMETOOLONG.
810 */
811 fts_free(p);
812 fts_lfree(head);
813 (void)closedir(dirp);
814 cur->fts_info = FTS_ERR;
815 SET(FTS_STOP);
816 errno = ENAMETOOLONG;
817 return (NULL);
818 }
819 #endif
820 p->fts_level = level;
821 p->fts_pathlen = ftsent_pathlen_truncate(len + dnamlen);
822 p->fts_parent = sp->fts_cur;
823
824 #ifdef FTS_WHITEOUT
825 if (dp->d_type == DT_WHT)
826 p->fts_flags |= FTS_ISW;
827 #endif
828
829 if (cderrno) {
830 if (nlinks) {
831 p->fts_info = FTS_NS;
832 p->fts_errno = cderrno;
833 } else
834 p->fts_info = FTS_NSOK;
835 p->fts_accpath = cur->fts_accpath;
836 } else if (nlinks == 0
837 #ifdef DT_DIR
838 || (nostat &&
839 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
840 #endif
841 ) {
842 p->fts_accpath =
843 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
844 p->fts_info = FTS_NSOK;
845 } else {
846 /* Build a file name for fts_stat to stat. */
847 if (ISSET(FTS_NOCHDIR)) {
848 p->fts_accpath = p->fts_path;
849 memmove(cp, p->fts_name,
850 (size_t)(p->fts_namelen + 1));
851 } else
852 p->fts_accpath = p->fts_name;
853 /* Stat it. */
854 p->fts_info = fts_stat(sp, p, 0);
855
856 /* Decrement link count if applicable. */
857 if (nlinks > 0 && (p->fts_info == FTS_D ||
858 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
859 --nlinks;
860 }
861
862 /* We walk in directory order so "ls -f" doesn't get upset. */
863 p->fts_link = NULL;
864 if (head == NULL)
865 head = tail = p;
866 else {
867 tail->fts_link = p;
868 tail = p;
869 }
870 ++nitems;
871 }
872 (void)closedir(dirp);
873
874 /*
875 * If had to realloc the path, adjust the addresses for the rest
876 * of the tree.
877 */
878 if (doadjust)
879 fts_padjust(sp, head);
880
881 /*
882 * If not changing directories, reset the path back to original
883 * state.
884 */
885 if (ISSET(FTS_NOCHDIR)) {
886 if (len == sp->fts_pathlen || nitems == 0)
887 --cp;
888 *cp = '\0';
889 }
890
891 /*
892 * If descended after called from fts_children or after called from
893 * fts_read and nothing found, get back. At the root level we use
894 * the saved fd; if one of fts_open()'s arguments is a relative path
895 * to an empty directory, we wind up here with no other way back. If
896 * can't get back, we're done.
897 */
898 if (descend && (type == BCHILD || !nitems) &&
899 (cur->fts_level == FTS_ROOTLEVEL ?
900 FCHDIR(sp, sp->fts_rfd) :
901 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
902 cur->fts_info = FTS_ERR;
903 SET(FTS_STOP);
904 return (NULL);
905 }
906
907 /* If didn't find anything, return NULL. */
908 if (!nitems) {
909 if (type == BREAD)
910 cur->fts_info = FTS_DP;
911 return (NULL);
912 }
913
914 /* Sort the entries. */
915 if (sp->fts_compar && nitems > 1)
916 head = fts_sort(sp, head, nitems);
917 return (head);
918 }
919
920 static unsigned short
fts_stat(FTS * sp,FTSENT * p,int follow)921 fts_stat(FTS *sp, FTSENT *p, int follow)
922 {
923 FTSENT *t;
924 dev_t dev;
925 __fts_ino_t ino;
926 __fts_stat_t *sbp, sb;
927 int saved_errno;
928
929 _DIAGASSERT(sp != NULL);
930 _DIAGASSERT(p != NULL);
931
932 /* If user needs stat info, stat buffer already allocated. */
933 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
934
935 #ifdef FTS_WHITEOUT
936 /* check for whiteout */
937 if (p->fts_flags & FTS_ISW) {
938 if (sbp != &sb) {
939 memset(sbp, '\0', sizeof (*sbp));
940 sbp->st_mode = S_IFWHT;
941 }
942 return (FTS_W);
943 }
944 #endif
945
946 /*
947 * If doing a logical walk, or application requested FTS_FOLLOW, do
948 * a stat(2). If that fails, check for a non-existent symlink. If
949 * fail, set the errno from the stat call.
950 */
951 if (ISSET(FTS_LOGICAL) || follow) {
952 if (stat(p->fts_accpath, sbp)) {
953 saved_errno = errno;
954 if (!lstat(p->fts_accpath, sbp)) {
955 errno = 0;
956 return (FTS_SLNONE);
957 }
958 p->fts_errno = saved_errno;
959 goto err;
960 }
961 } else if (lstat(p->fts_accpath, sbp)) {
962 p->fts_errno = errno;
963 err: memset(sbp, 0, sizeof(*sbp));
964 return (FTS_NS);
965 }
966
967 if (S_ISDIR(sbp->st_mode)) {
968 /*
969 * Set the device/inode. Used to find cycles and check for
970 * crossing mount points. Also remember the link count, used
971 * in fts_build to limit the number of stat calls. It is
972 * understood that these fields are only referenced if fts_info
973 * is set to FTS_D.
974 */
975 dev = p->fts_dev = sbp->st_dev;
976 ino = p->fts_ino = sbp->st_ino;
977 p->fts_nlink = sbp->st_nlink;
978
979 if (ISDOT(p->fts_name))
980 return (FTS_DOT);
981
982 /*
983 * Cycle detection is done by brute force when the directory
984 * is first encountered. If the tree gets deep enough or the
985 * number of symbolic links to directories is high enough,
986 * something faster might be worthwhile.
987 */
988 for (t = p->fts_parent;
989 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
990 if (ino == t->fts_ino && dev == t->fts_dev) {
991 p->fts_cycle = t;
992 return (FTS_DC);
993 }
994 return (FTS_D);
995 }
996 if (S_ISLNK(sbp->st_mode))
997 return (FTS_SL);
998 if (S_ISREG(sbp->st_mode))
999 return (FTS_F);
1000 return (FTS_DEFAULT);
1001 }
1002
1003 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,size_t nitems)1004 fts_sort(FTS *sp, FTSENT *head, size_t nitems)
1005 {
1006 FTSENT **ap, *p;
1007
1008 _DIAGASSERT(sp != NULL);
1009 _DIAGASSERT(head != NULL);
1010
1011 /*
1012 * Construct an array of pointers to the structures and call qsort(3).
1013 * Reassemble the array in the order returned by qsort. If unable to
1014 * sort for memory reasons, return the directory entries in their
1015 * current order. Allocate enough space for the current needs plus
1016 * 40 so don't realloc one entry at a time.
1017 */
1018 if (nitems > sp->fts_nitems) {
1019 FTSENT **new;
1020
1021 new = realloc(sp->fts_array, sizeof(FTSENT *) * (nitems + 40));
1022 if (new == 0)
1023 return (head);
1024 sp->fts_array = new;
1025 sp->fts_nitems = fts_nitems_truncate(nitems + 40);
1026 }
1027 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1028 *ap++ = p;
1029 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *),
1030 (int (*)(const void *, const void *))sp->fts_compar);
1031 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1032 ap[0]->fts_link = ap[1];
1033 ap[0]->fts_link = NULL;
1034 return (head);
1035 }
1036
1037 static FTSENT *
fts_alloc(FTS * sp,const char * name,size_t namelen)1038 fts_alloc(FTS *sp, const char *name, size_t namelen)
1039 {
1040 FTSENT *p;
1041 #if defined(FTS_ALLOC_ALIGNED)
1042 size_t len;
1043 #endif
1044
1045 _DIAGASSERT(sp != NULL);
1046 _DIAGASSERT(name != NULL);
1047
1048 #if defined(FTS_ALLOC_ALIGNED)
1049 /*
1050 * The file name is a variable length array and no stat structure is
1051 * necessary if the user has set the nostat bit. Allocate the FTSENT
1052 * structure, the file name and the stat structure in one chunk, but
1053 * be careful that the stat structure is reasonably aligned. Since the
1054 * fts_name field is declared to be of size 1, the fts_name pointer is
1055 * namelen + 2 before the first possible address of the stat structure.
1056 */
1057 len = sizeof(FTSENT) + namelen;
1058 if (!ISSET(FTS_NOSTAT))
1059 len += sizeof(*(p->fts_statp)) + ALIGNBYTES;
1060 if ((p = malloc(len)) == NULL)
1061 return (NULL);
1062
1063 if (!ISSET(FTS_NOSTAT))
1064 p->fts_statp = (__fts_stat_t *)ALIGN(
1065 (unsigned long)(p->fts_name + namelen + 2));
1066 #else
1067 if ((p = malloc(sizeof(FTSENT) + namelen)) == NULL)
1068 return (NULL);
1069
1070 if (!ISSET(FTS_NOSTAT))
1071 if ((p->fts_statp = malloc(sizeof(*(p->fts_statp)))) == NULL) {
1072 free(p);
1073 return (NULL);
1074 }
1075 #endif
1076
1077 if (ISSET(FTS_NOSTAT))
1078 p->fts_statp = NULL;
1079
1080 /* Copy the name plus the trailing NULL. */
1081 memmove(p->fts_name, name, namelen + 1);
1082
1083 p->fts_namelen = ftsent_namelen_truncate(namelen);
1084 p->fts_path = sp->fts_path;
1085 p->fts_errno = 0;
1086 p->fts_flags = 0;
1087 p->fts_instr = FTS_NOINSTR;
1088 p->fts_number = 0;
1089 p->fts_pointer = NULL;
1090 return (p);
1091 }
1092
1093 static void
fts_free(FTSENT * p)1094 fts_free(FTSENT *p)
1095 {
1096 #if !defined(FTS_ALLOC_ALIGNED)
1097 if (p->fts_statp)
1098 free(p->fts_statp);
1099 #endif
1100 free(p);
1101 }
1102
1103 static void
fts_lfree(FTSENT * head)1104 fts_lfree(FTSENT *head)
1105 {
1106 FTSENT *p;
1107
1108 /* XXX: head may be NULL ? */
1109
1110 /* Free a linked list of structures. */
1111 while ((p = head) != NULL) {
1112 head = head->fts_link;
1113 fts_free(p);
1114 }
1115 }
1116
1117 static size_t
fts_pow2(size_t x)1118 fts_pow2(size_t x)
1119 {
1120
1121 x--;
1122 x |= x>>1;
1123 x |= x>>2;
1124 x |= x>>4;
1125 x |= x>>8;
1126 x |= x>>16;
1127 #if LONG_BIT > 32
1128 x |= x>>32;
1129 #endif
1130 #if LONG_BIT > 64
1131 x |= x>>64;
1132 #endif
1133 x++;
1134 return (x);
1135 }
1136
1137 /*
1138 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
1139 * Most systems will allow creation of paths much longer than MAXPATHLEN, even
1140 * though the kernel won't resolve them. Round up the new size to a power of 2,
1141 * so we don't realloc the path 2 bytes at a time.
1142 */
1143 static int
fts_palloc(FTS * sp,size_t size)1144 fts_palloc(FTS *sp, size_t size)
1145 {
1146 char *new;
1147
1148 _DIAGASSERT(sp != NULL);
1149
1150 #ifdef __FTS_COMPAT_LENGTH
1151 /* Protect against fts_pathlen overflow. */
1152 if (size > USHRT_MAX + 1) {
1153 errno = ENAMETOOLONG;
1154 return (1);
1155 }
1156 #endif
1157 size = fts_pow2(size);
1158 new = realloc(sp->fts_path, size);
1159 if (new == 0)
1160 return (1);
1161 sp->fts_path = new;
1162 sp->fts_pathlen = fts_pathlen_truncate(size);
1163 return (0);
1164 }
1165
1166 /*
1167 * When the path is realloc'd, have to fix all of the pointers in structures
1168 * already returned.
1169 */
1170 static void
fts_padjust(FTS * sp,FTSENT * head)1171 fts_padjust(FTS *sp, FTSENT *head)
1172 {
1173 FTSENT *p;
1174 char *addr;
1175
1176 _DIAGASSERT(sp != NULL);
1177
1178 #define ADJUST(p) do { \
1179 if ((p)->fts_accpath != (p)->fts_name) \
1180 (p)->fts_accpath = \
1181 addr + ((p)->fts_accpath - (p)->fts_path); \
1182 (p)->fts_path = addr; \
1183 } while (/*CONSTCOND*/0)
1184
1185 addr = sp->fts_path;
1186
1187 /* Adjust the current set of children. */
1188 for (p = sp->fts_child; p; p = p->fts_link)
1189 ADJUST(p);
1190
1191 /* Adjust the rest of the tree, including the current level. */
1192 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1193 ADJUST(p);
1194 p = p->fts_link ? p->fts_link : p->fts_parent;
1195 }
1196 }
1197
1198 static size_t
fts_maxarglen(char * const * argv)1199 fts_maxarglen(char * const *argv)
1200 {
1201 size_t len, max;
1202
1203 _DIAGASSERT(argv != NULL);
1204
1205 for (max = 0; *argv; ++argv)
1206 if ((len = strlen(*argv)) > max)
1207 max = len;
1208 return (max + 1);
1209 }
1210
1211 #if defined(__minix)
1212 #if ! HAVE_NBTOOL_CONFIG_H
1213 #include <minix/dmap.h>
1214 #else
1215 #define NONE_MAJOR 0
1216 #endif
1217 #endif /* defined(__minix) */
1218
1219 /*
1220 * Change to dir specified by fd or p->fts_accpath without getting
1221 * tricked by someone changing the world out from underneath us.
1222 * Assumes p->fts_dev and p->fts_ino are filled in.
1223 */
1224 static int
fts_safe_changedir(const FTS * sp,const FTSENT * p,int fd,const char * path)1225 fts_safe_changedir(const FTS *sp, const FTSENT *p, int fd, const char *path)
1226 {
1227 int oldfd = fd, ret = -1;
1228 __fts_stat_t sb;
1229
1230 if (ISSET(FTS_NOCHDIR))
1231 return 0;
1232
1233 if (oldfd < 0 && (fd = open(path, O_RDONLY | O_CLOEXEC)) == -1)
1234 return -1;
1235
1236 if (fstat(fd, &sb) == -1)
1237 goto bail;
1238
1239 #if defined(__minix)
1240 /*
1241 * Skip the safety check on file systems where inodes are not static.
1242 * On such file systems, a file may legitimately be assigned a new
1243 * inode number due to being deleted and regenerated while we are
1244 * running. This behavior is not POSIX compliant, but necessary for
1245 * certain types of file systems. Currently, we assume that this
1246 * applies to all (and only) file systems that are not device backed.
1247 * In the future, we may have to obtain an appropriate flag through
1248 * statvfs(3) instead.
1249 */
1250 if ((sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev)
1251 && major(sb.st_dev) != NONE_MAJOR) {
1252 #else
1253 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) {
1254 #endif /* defined(__minix) */
1255 errno = ENOENT;
1256 goto bail;
1257 }
1258
1259 ret = fchdir(fd);
1260
1261 bail:
1262 if (oldfd < 0) {
1263 int save_errno = errno;
1264 (void)close(fd);
1265 errno = save_errno;
1266 }
1267 return ret;
1268 }
1269