1 /*-
2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $
30 */
31
32 #if 0
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94";
35 #endif /* LIBC_SCCS and not lint */
36 #endif
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include "namespace.h"
42 #include <sys/param.h>
43 #include <sys/mount.h>
44 #include <sys/stat.h>
45
46 #include <dirent.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "fts-compat.h"
53 #include "un-namespace.h"
54
55 #include "gen-private.h"
56
57 FTSENT *__fts_children_44bsd(FTS *, int);
58 int __fts_close_44bsd(FTS *);
59 void *__fts_get_clientptr_44bsd(FTS *);
60 FTS *__fts_get_stream_44bsd(FTSENT *);
61 FTS *__fts_open_44bsd(char * const *, int,
62 int (*)(const FTSENT * const *, const FTSENT * const *));
63 FTSENT *__fts_read_44bsd(FTS *);
64 int __fts_set_44bsd(FTS *, FTSENT *, int);
65 void __fts_set_clientptr_44bsd(FTS *, void *);
66
67 static FTSENT *fts_alloc(FTS *, char *, int);
68 static FTSENT *fts_build(FTS *, int);
69 static void fts_lfree(FTSENT *);
70 static void fts_load(FTS *, FTSENT *);
71 static size_t fts_maxarglen(char * const *);
72 static void fts_padjust(FTS *, FTSENT *);
73 static int fts_palloc(FTS *, size_t);
74 static FTSENT *fts_sort(FTS *, FTSENT *, int);
75 static u_short fts_stat(FTS *, FTSENT *, int);
76 static int fts_safe_changedir(FTS *, FTSENT *, int, char *);
77 static int fts_ufslinks(FTS *, const FTSENT *);
78
79 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
80
81 #define CLR(opt) (sp->fts_options &= ~(opt))
82 #define ISSET(opt) (sp->fts_options & (opt))
83 #define SET(opt) (sp->fts_options |= (opt))
84
85 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
86
87 /* fts_build flags */
88 #define BCHILD 1 /* fts_children */
89 #define BNAMES 2 /* fts_children, names only */
90 #define BREAD 3 /* fts_read */
91
92 /*
93 * Internal representation of an FTS, including extra implementation
94 * details. The FTS returned from fts_open points to this structure's
95 * ftsp_fts member (and can be cast to an _fts_private as required)
96 */
97 struct _fts_private {
98 FTS ftsp_fts;
99 struct statfs ftsp_statfs;
100 dev_t ftsp_dev;
101 int ftsp_linksreliable;
102 };
103
104 /*
105 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it
106 * knows that a directory could not possibly have subdirectories. This
107 * is decided by looking at the link count: a subdirectory would
108 * increment its parent's link count by virtue of its own ".." entry.
109 * This assumption only holds for UFS-like filesystems that implement
110 * links and directories this way, so we must punt for others.
111 */
112
113 static const char *ufslike_filesystems[] = {
114 "ufs",
115 "zfs",
116 "nfs",
117 "nfs4",
118 "ext2fs",
119 0
120 };
121
122 FTS *
__fts_open_44bsd(char * const * argv,int options,int (* compar)(const FTSENT * const *,const FTSENT * const *))123 __fts_open_44bsd(char * const *argv, int options,
124 int (*compar)(const FTSENT * const *, const FTSENT * const *))
125 {
126 struct _fts_private *priv;
127 FTS *sp;
128 FTSENT *p, *root;
129 int nitems;
130 FTSENT *parent, *tmp;
131 int len;
132
133 /* Options check. */
134 if (options & ~FTS_OPTIONMASK) {
135 errno = EINVAL;
136 return (NULL);
137 }
138
139 /* Allocate/initialize the stream. */
140 if ((priv = calloc(1, sizeof(*priv))) == NULL)
141 return (NULL);
142 sp = &priv->ftsp_fts;
143 sp->fts_compar = compar;
144 sp->fts_options = options;
145
146 /* Shush, GCC. */
147 tmp = NULL;
148
149 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
150 if (ISSET(FTS_LOGICAL))
151 SET(FTS_NOCHDIR);
152
153 /*
154 * Start out with 1K of path space, and enough, in any case,
155 * to hold the user's paths.
156 */
157 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
158 goto mem1;
159
160 /* Allocate/initialize root's parent. */
161 if ((parent = fts_alloc(sp, "", 0)) == NULL)
162 goto mem2;
163 parent->fts_level = FTS_ROOTPARENTLEVEL;
164
165 /* Allocate/initialize root(s). */
166 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
167 /* Don't allow zero-length paths. */
168 if ((len = strlen(*argv)) == 0) {
169 errno = ENOENT;
170 goto mem3;
171 }
172
173 p = fts_alloc(sp, *argv, len);
174 p->fts_level = FTS_ROOTLEVEL;
175 p->fts_parent = parent;
176 p->fts_accpath = p->fts_name;
177 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
178
179 /* Command-line "." and ".." are real directories. */
180 if (p->fts_info == FTS_DOT)
181 p->fts_info = FTS_D;
182
183 /*
184 * If comparison routine supplied, traverse in sorted
185 * order; otherwise traverse in the order specified.
186 */
187 if (compar) {
188 p->fts_link = root;
189 root = p;
190 } else {
191 p->fts_link = NULL;
192 if (root == NULL)
193 tmp = root = p;
194 else {
195 tmp->fts_link = p;
196 tmp = p;
197 }
198 }
199 }
200 if (compar && nitems > 1)
201 root = fts_sort(sp, root, nitems);
202
203 /*
204 * Allocate a dummy pointer and make fts_read think that we've just
205 * finished the node before the root(s); set p->fts_info to FTS_INIT
206 * so that everything about the "current" node is ignored.
207 */
208 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
209 goto mem3;
210 sp->fts_cur->fts_link = root;
211 sp->fts_cur->fts_info = FTS_INIT;
212
213 /*
214 * If using chdir(2), grab a file descriptor pointing to dot to ensure
215 * that we can get back here; this could be avoided for some paths,
216 * but almost certainly not worth the effort. Slashes, symbolic links,
217 * and ".." are all fairly nasty problems. Note, if we can't get the
218 * descriptor we run anyway, just more slowly.
219 */
220 if (!ISSET(FTS_NOCHDIR) &&
221 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
222 SET(FTS_NOCHDIR);
223
224 return (sp);
225
226 mem3: fts_lfree(root);
227 free(parent);
228 mem2: free(sp->fts_path);
229 mem1: free(sp);
230 return (NULL);
231 }
232
233 static void
fts_load(FTS * sp,FTSENT * p)234 fts_load(FTS *sp, FTSENT *p)
235 {
236 int len;
237 char *cp;
238
239 /*
240 * Load the stream structure for the next traversal. Since we don't
241 * actually enter the directory until after the preorder visit, set
242 * the fts_accpath field specially so the chdir gets done to the right
243 * place and the user can access the first node. From fts_open it's
244 * known that the path will fit.
245 */
246 len = p->fts_pathlen = p->fts_namelen;
247 memmove(sp->fts_path, p->fts_name, len + 1);
248 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
249 len = strlen(++cp);
250 memmove(p->fts_name, cp, len + 1);
251 p->fts_namelen = len;
252 }
253 p->fts_accpath = p->fts_path = sp->fts_path;
254 sp->fts_dev = p->fts_dev;
255 }
256
257 int
__fts_close_44bsd(FTS * sp)258 __fts_close_44bsd(FTS *sp)
259 {
260 FTSENT *freep, *p;
261 int saved_errno;
262
263 /*
264 * This still works if we haven't read anything -- the dummy structure
265 * points to the root list, so we step through to the end of the root
266 * list which has a valid parent pointer.
267 */
268 if (sp->fts_cur) {
269 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
270 freep = p;
271 p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
272 free(freep);
273 }
274 free(p);
275 }
276
277 /* Free up child linked list, sort array, path buffer. */
278 if (sp->fts_child)
279 fts_lfree(sp->fts_child);
280 if (sp->fts_array)
281 free(sp->fts_array);
282 free(sp->fts_path);
283
284 /* Return to original directory, save errno if necessary. */
285 if (!ISSET(FTS_NOCHDIR)) {
286 saved_errno = fchdir(sp->fts_rfd) ? errno : 0;
287 (void)_close(sp->fts_rfd);
288
289 /* Set errno and return. */
290 if (saved_errno != 0) {
291 /* Free up the stream pointer. */
292 free(sp);
293 errno = saved_errno;
294 return (-1);
295 }
296 }
297
298 /* Free up the stream pointer. */
299 free(sp);
300 return (0);
301 }
302
303 /*
304 * Special case of "/" at the end of the path so that slashes aren't
305 * appended which would cause paths to be written as "....//foo".
306 */
307 #define NAPPEND(p) \
308 (p->fts_path[p->fts_pathlen - 1] == '/' \
309 ? p->fts_pathlen - 1 : p->fts_pathlen)
310
311 FTSENT *
__fts_read_44bsd(FTS * sp)312 __fts_read_44bsd(FTS *sp)
313 {
314 FTSENT *p, *tmp;
315 int instr;
316 char *t;
317 int saved_errno;
318
319 /* If finished or unrecoverable error, return NULL. */
320 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
321 return (NULL);
322
323 /* Set current node pointer. */
324 p = sp->fts_cur;
325
326 /* Save and zero out user instructions. */
327 instr = p->fts_instr;
328 p->fts_instr = FTS_NOINSTR;
329
330 /* Any type of file may be re-visited; re-stat and re-turn. */
331 if (instr == FTS_AGAIN) {
332 p->fts_info = fts_stat(sp, p, 0);
333 return (p);
334 }
335
336 /*
337 * Following a symlink -- SLNONE test allows application to see
338 * SLNONE and recover. If indirecting through a symlink, have
339 * keep a pointer to current location. If unable to get that
340 * pointer, follow fails.
341 */
342 if (instr == FTS_FOLLOW &&
343 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
344 p->fts_info = fts_stat(sp, p, 1);
345 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
346 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC,
347 0)) < 0) {
348 p->fts_errno = errno;
349 p->fts_info = FTS_ERR;
350 } else
351 p->fts_flags |= FTS_SYMFOLLOW;
352 }
353 return (p);
354 }
355
356 /* Directory in pre-order. */
357 if (p->fts_info == FTS_D) {
358 /* If skipped or crossed mount point, do post-order visit. */
359 if (instr == FTS_SKIP ||
360 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
361 if (p->fts_flags & FTS_SYMFOLLOW)
362 (void)_close(p->fts_symfd);
363 if (sp->fts_child) {
364 fts_lfree(sp->fts_child);
365 sp->fts_child = NULL;
366 }
367 p->fts_info = FTS_DP;
368 return (p);
369 }
370
371 /* Rebuild if only read the names and now traversing. */
372 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
373 CLR(FTS_NAMEONLY);
374 fts_lfree(sp->fts_child);
375 sp->fts_child = NULL;
376 }
377
378 /*
379 * Cd to the subdirectory.
380 *
381 * If have already read and now fail to chdir, whack the list
382 * to make the names come out right, and set the parent errno
383 * so the application will eventually get an error condition.
384 * Set the FTS_DONTCHDIR flag so that when we logically change
385 * directories back to the parent we don't do a chdir.
386 *
387 * If haven't read do so. If the read fails, fts_build sets
388 * FTS_STOP or the fts_info field of the node.
389 */
390 if (sp->fts_child != NULL) {
391 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
392 p->fts_errno = errno;
393 p->fts_flags |= FTS_DONTCHDIR;
394 for (p = sp->fts_child; p != NULL;
395 p = p->fts_link)
396 p->fts_accpath =
397 p->fts_parent->fts_accpath;
398 }
399 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
400 if (ISSET(FTS_STOP))
401 return (NULL);
402 return (p);
403 }
404 p = sp->fts_child;
405 sp->fts_child = NULL;
406 goto name;
407 }
408
409 /* Move to the next node on this level. */
410 next: tmp = p;
411 if ((p = p->fts_link) != NULL) {
412 free(tmp);
413
414 /*
415 * If reached the top, return to the original directory (or
416 * the root of the tree), and load the paths for the next root.
417 */
418 if (p->fts_level == FTS_ROOTLEVEL) {
419 if (FCHDIR(sp, sp->fts_rfd)) {
420 SET(FTS_STOP);
421 return (NULL);
422 }
423 fts_load(sp, p);
424 return (sp->fts_cur = p);
425 }
426
427 /*
428 * User may have called fts_set on the node. If skipped,
429 * ignore. If followed, get a file descriptor so we can
430 * get back if necessary.
431 */
432 if (p->fts_instr == FTS_SKIP)
433 goto next;
434 if (p->fts_instr == FTS_FOLLOW) {
435 p->fts_info = fts_stat(sp, p, 1);
436 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
437 if ((p->fts_symfd =
438 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) {
439 p->fts_errno = errno;
440 p->fts_info = FTS_ERR;
441 } else
442 p->fts_flags |= FTS_SYMFOLLOW;
443 }
444 p->fts_instr = FTS_NOINSTR;
445 }
446
447 name: t = sp->fts_path + NAPPEND(p->fts_parent);
448 *t++ = '/';
449 memmove(t, p->fts_name, p->fts_namelen + 1);
450 return (sp->fts_cur = p);
451 }
452
453 /* Move up to the parent node. */
454 p = tmp->fts_parent;
455 free(tmp);
456
457 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
458 /*
459 * Done; free everything up and set errno to 0 so the user
460 * can distinguish between error and EOF.
461 */
462 free(p);
463 errno = 0;
464 return (sp->fts_cur = NULL);
465 }
466
467 /* NUL terminate the pathname. */
468 sp->fts_path[p->fts_pathlen] = '\0';
469
470 /*
471 * Return to the parent directory. If at a root node or came through
472 * a symlink, go back through the file descriptor. Otherwise, cd up
473 * one directory.
474 */
475 if (p->fts_level == FTS_ROOTLEVEL) {
476 if (FCHDIR(sp, sp->fts_rfd)) {
477 SET(FTS_STOP);
478 return (NULL);
479 }
480 } else if (p->fts_flags & FTS_SYMFOLLOW) {
481 if (FCHDIR(sp, p->fts_symfd)) {
482 saved_errno = errno;
483 (void)_close(p->fts_symfd);
484 errno = saved_errno;
485 SET(FTS_STOP);
486 return (NULL);
487 }
488 (void)_close(p->fts_symfd);
489 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
490 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
491 SET(FTS_STOP);
492 return (NULL);
493 }
494 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
495 return (sp->fts_cur = p);
496 }
497
498 /*
499 * Fts_set takes the stream as an argument although it's not used in this
500 * implementation; it would be necessary if anyone wanted to add global
501 * semantics to fts using fts_set. An error return is allowed for similar
502 * reasons.
503 */
504 /* ARGSUSED */
505 int
__fts_set_44bsd(FTS * sp,FTSENT * p,int instr)506 __fts_set_44bsd(FTS *sp, FTSENT *p, int instr)
507 {
508 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
509 instr != FTS_NOINSTR && instr != FTS_SKIP) {
510 errno = EINVAL;
511 return (1);
512 }
513 p->fts_instr = instr;
514 return (0);
515 }
516
517 FTSENT *
__fts_children_44bsd(FTS * sp,int instr)518 __fts_children_44bsd(FTS *sp, int instr)
519 {
520 FTSENT *p;
521 int fd;
522
523 if (instr != 0 && instr != FTS_NAMEONLY) {
524 errno = EINVAL;
525 return (NULL);
526 }
527
528 /* Set current node pointer. */
529 p = sp->fts_cur;
530
531 /*
532 * Errno set to 0 so user can distinguish empty directory from
533 * an error.
534 */
535 errno = 0;
536
537 /* Fatal errors stop here. */
538 if (ISSET(FTS_STOP))
539 return (NULL);
540
541 /* Return logical hierarchy of user's arguments. */
542 if (p->fts_info == FTS_INIT)
543 return (p->fts_link);
544
545 /*
546 * If not a directory being visited in pre-order, stop here. Could
547 * allow FTS_DNR, assuming the user has fixed the problem, but the
548 * same effect is available with FTS_AGAIN.
549 */
550 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
551 return (NULL);
552
553 /* Free up any previous child list. */
554 if (sp->fts_child != NULL)
555 fts_lfree(sp->fts_child);
556
557 if (instr == FTS_NAMEONLY) {
558 SET(FTS_NAMEONLY);
559 instr = BNAMES;
560 } else
561 instr = BCHILD;
562
563 /*
564 * If using chdir on a relative path and called BEFORE fts_read does
565 * its chdir to the root of a traversal, we can lose -- we need to
566 * chdir into the subdirectory, and we don't know where the current
567 * directory is, so we can't get back so that the upcoming chdir by
568 * fts_read will work.
569 */
570 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
571 ISSET(FTS_NOCHDIR))
572 return (sp->fts_child = fts_build(sp, instr));
573
574 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
575 return (NULL);
576 sp->fts_child = fts_build(sp, instr);
577 if (fchdir(fd))
578 return (NULL);
579 (void)_close(fd);
580 return (sp->fts_child);
581 }
582
583 #ifndef fts_get_clientptr
584 #error "fts_get_clientptr not defined"
585 #endif
586
587 void *
588 (__fts_get_clientptr_44bsd)(FTS *sp)
589 {
590
591 return (fts_get_clientptr(sp));
592 }
593
594 #ifndef fts_get_stream
595 #error "fts_get_stream not defined"
596 #endif
597
598 FTS *
599 (__fts_get_stream_44bsd)(FTSENT *p)
600 {
601 return (fts_get_stream(p));
602 }
603
604 void
__fts_set_clientptr_44bsd(FTS * sp,void * clientptr)605 __fts_set_clientptr_44bsd(FTS *sp, void *clientptr)
606 {
607
608 sp->fts_clientptr = clientptr;
609 }
610
611 /*
612 * This is the tricky part -- do not casually change *anything* in here. The
613 * idea is to build the linked list of entries that are used by fts_children
614 * and fts_read. There are lots of special cases.
615 *
616 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
617 * set and it's a physical walk (so that symbolic links can't be directories),
618 * we can do things quickly. First, if it's a 4.4BSD file system, the type
619 * of the file is in the directory entry. Otherwise, we assume that the number
620 * of subdirectories in a node is equal to the number of links to the parent.
621 * The former skips all stat calls. The latter skips stat calls in any leaf
622 * directories and for any files after the subdirectories in the directory have
623 * been found, cutting the stat calls by about 2/3.
624 */
625 static FTSENT *
fts_build(FTS * sp,int type)626 fts_build(FTS *sp, int type)
627 {
628 struct dirent *dp;
629 FTSENT *p, *head;
630 int nitems;
631 FTSENT *cur, *tail;
632 DIR *dirp;
633 void *oldaddr;
634 size_t dnamlen;
635 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno,
636 nostat, doadjust;
637 char *cp;
638
639 /* Set current node pointer. */
640 cur = sp->fts_cur;
641
642 /*
643 * Open the directory for reading. If this fails, we're done.
644 * If being called from fts_read, set the fts_info field.
645 */
646 #ifdef FTS_WHITEOUT
647 if (ISSET(FTS_WHITEOUT))
648 oflag = DTF_NODUP | DTF_REWIND;
649 else
650 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND;
651 #else
652 #define __opendir2(path, flag) opendir(path)
653 #endif
654 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
655 if (type == BREAD) {
656 cur->fts_info = FTS_DNR;
657 cur->fts_errno = errno;
658 }
659 return (NULL);
660 }
661
662 /*
663 * Nlinks is the number of possible entries of type directory in the
664 * directory if we're cheating on stat calls, 0 if we're not doing
665 * any stat calls at all, -1 if we're doing stats on everything.
666 */
667 if (type == BNAMES) {
668 nlinks = 0;
669 /* Be quiet about nostat, GCC. */
670 nostat = 0;
671 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
672 if (fts_ufslinks(sp, cur))
673 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
674 else
675 nlinks = -1;
676 nostat = 1;
677 } else {
678 nlinks = -1;
679 nostat = 0;
680 }
681
682 #ifdef notdef
683 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
684 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
685 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
686 #endif
687 /*
688 * If we're going to need to stat anything or we want to descend
689 * and stay in the directory, chdir. If this fails we keep going,
690 * but set a flag so we don't chdir after the post-order visit.
691 * We won't be able to stat anything, but we can still return the
692 * names themselves. Note, that since fts_read won't be able to
693 * chdir into the directory, it will have to return different path
694 * names than before, i.e. "a/b" instead of "b". Since the node
695 * has already been visited in pre-order, have to wait until the
696 * post-order visit to return the error. There is a special case
697 * here, if there was nothing to stat then it's not an error to
698 * not be able to stat. This is all fairly nasty. If a program
699 * needed sorted entries or stat information, they had better be
700 * checking FTS_NS on the returned nodes.
701 */
702 cderrno = 0;
703 if (nlinks || type == BREAD) {
704 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) {
705 if (nlinks && type == BREAD)
706 cur->fts_errno = errno;
707 cur->fts_flags |= FTS_DONTCHDIR;
708 descend = 0;
709 cderrno = errno;
710 } else
711 descend = 1;
712 } else
713 descend = 0;
714
715 /*
716 * Figure out the max file name length that can be stored in the
717 * current path -- the inner loop allocates more path as necessary.
718 * We really wouldn't have to do the maxlen calculations here, we
719 * could do them in fts_read before returning the path, but it's a
720 * lot easier here since the length is part of the dirent structure.
721 *
722 * If not changing directories set a pointer so that can just append
723 * each new name into the path.
724 */
725 len = NAPPEND(cur);
726 if (ISSET(FTS_NOCHDIR)) {
727 cp = sp->fts_path + len;
728 *cp++ = '/';
729 } else {
730 /* GCC, you're too verbose. */
731 cp = NULL;
732 }
733 len++;
734 maxlen = sp->fts_pathlen - len;
735
736 level = cur->fts_level + 1;
737
738 /* Read the directory, attaching each entry to the `link' pointer. */
739 doadjust = 0;
740 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
741 dnamlen = dp->d_namlen;
742 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
743 continue;
744
745 if ((p = fts_alloc(sp, dp->d_name, (int)dnamlen)) == NULL)
746 goto mem1;
747 if (dnamlen >= maxlen) { /* include space for NUL */
748 oldaddr = sp->fts_path;
749 if (fts_palloc(sp, dnamlen + len + 1)) {
750 /*
751 * No more memory for path or structures. Save
752 * errno, free up the current structure and the
753 * structures already allocated.
754 */
755 mem1: saved_errno = errno;
756 if (p)
757 free(p);
758 fts_lfree(head);
759 (void)closedir(dirp);
760 cur->fts_info = FTS_ERR;
761 SET(FTS_STOP);
762 errno = saved_errno;
763 return (NULL);
764 }
765 /* Did realloc() change the pointer? */
766 if (oldaddr != sp->fts_path) {
767 doadjust = 1;
768 if (ISSET(FTS_NOCHDIR))
769 cp = sp->fts_path + len;
770 }
771 maxlen = sp->fts_pathlen - len;
772 }
773
774 if (len + dnamlen >= USHRT_MAX) {
775 /*
776 * In an FTSENT, fts_pathlen is a u_short so it is
777 * possible to wraparound here. If we do, free up
778 * the current structure and the structures already
779 * allocated, then error out with ENAMETOOLONG.
780 */
781 free(p);
782 fts_lfree(head);
783 (void)closedir(dirp);
784 cur->fts_info = FTS_ERR;
785 SET(FTS_STOP);
786 errno = ENAMETOOLONG;
787 return (NULL);
788 }
789 p->fts_level = level;
790 p->fts_parent = sp->fts_cur;
791 p->fts_pathlen = len + dnamlen;
792
793 #ifdef FTS_WHITEOUT
794 if (dp->d_type == DT_WHT)
795 p->fts_flags |= FTS_ISW;
796 #endif
797
798 if (cderrno) {
799 if (nlinks) {
800 p->fts_info = FTS_NS;
801 p->fts_errno = cderrno;
802 } else
803 p->fts_info = FTS_NSOK;
804 p->fts_accpath = cur->fts_accpath;
805 } else if (nlinks == 0
806 #ifdef DT_DIR
807 || (nostat &&
808 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
809 #endif
810 ) {
811 p->fts_accpath =
812 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
813 p->fts_info = FTS_NSOK;
814 } else {
815 /* Build a file name for fts_stat to stat. */
816 if (ISSET(FTS_NOCHDIR)) {
817 p->fts_accpath = p->fts_path;
818 memmove(cp, p->fts_name, p->fts_namelen + 1);
819 } else
820 p->fts_accpath = p->fts_name;
821 /* Stat it. */
822 p->fts_info = fts_stat(sp, p, 0);
823
824 /* Decrement link count if applicable. */
825 if (nlinks > 0 && (p->fts_info == FTS_D ||
826 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
827 --nlinks;
828 }
829
830 /* We walk in directory order so "ls -f" doesn't get upset. */
831 p->fts_link = NULL;
832 if (head == NULL)
833 head = tail = p;
834 else {
835 tail->fts_link = p;
836 tail = p;
837 }
838 ++nitems;
839 }
840 if (dirp)
841 (void)closedir(dirp);
842
843 /*
844 * If realloc() changed the address of the path, adjust the
845 * addresses for the rest of the tree and the dir list.
846 */
847 if (doadjust)
848 fts_padjust(sp, head);
849
850 /*
851 * If not changing directories, reset the path back to original
852 * state.
853 */
854 if (ISSET(FTS_NOCHDIR)) {
855 if (len == sp->fts_pathlen || nitems == 0)
856 --cp;
857 *cp = '\0';
858 }
859
860 /*
861 * If descended after called from fts_children or after called from
862 * fts_read and nothing found, get back. At the root level we use
863 * the saved fd; if one of fts_open()'s arguments is a relative path
864 * to an empty directory, we wind up here with no other way back. If
865 * can't get back, we're done.
866 */
867 if (descend && (type == BCHILD || !nitems) &&
868 (cur->fts_level == FTS_ROOTLEVEL ?
869 FCHDIR(sp, sp->fts_rfd) :
870 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
871 cur->fts_info = FTS_ERR;
872 SET(FTS_STOP);
873 return (NULL);
874 }
875
876 /* If didn't find anything, return NULL. */
877 if (!nitems) {
878 if (type == BREAD)
879 cur->fts_info = FTS_DP;
880 return (NULL);
881 }
882
883 /* Sort the entries. */
884 if (sp->fts_compar && nitems > 1)
885 head = fts_sort(sp, head, nitems);
886 return (head);
887 }
888
889 static u_short
fts_stat(FTS * sp,FTSENT * p,int follow)890 fts_stat(FTS *sp, FTSENT *p, int follow)
891 {
892 FTSENT *t;
893 dev_t dev;
894 ino_t ino;
895 struct stat *sbp, sb;
896 int saved_errno;
897
898 /* If user needs stat info, stat buffer already allocated. */
899 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
900
901 #ifdef FTS_WHITEOUT
902 /* Check for whiteout. */
903 if (p->fts_flags & FTS_ISW) {
904 if (sbp != &sb) {
905 memset(sbp, '\0', sizeof(*sbp));
906 sbp->st_mode = S_IFWHT;
907 }
908 return (FTS_W);
909 }
910 #endif
911
912 /*
913 * If doing a logical walk, or application requested FTS_FOLLOW, do
914 * a stat(2). If that fails, check for a non-existent symlink. If
915 * fail, set the errno from the stat call.
916 */
917 if (ISSET(FTS_LOGICAL) || follow) {
918 if (stat(p->fts_accpath, sbp)) {
919 saved_errno = errno;
920 if (!lstat(p->fts_accpath, sbp)) {
921 errno = 0;
922 return (FTS_SLNONE);
923 }
924 p->fts_errno = saved_errno;
925 goto err;
926 }
927 } else if (lstat(p->fts_accpath, sbp)) {
928 p->fts_errno = errno;
929 err: memset(sbp, 0, sizeof(struct stat));
930 return (FTS_NS);
931 }
932
933 if (S_ISDIR(sbp->st_mode)) {
934 /*
935 * Set the device/inode. Used to find cycles and check for
936 * crossing mount points. Also remember the link count, used
937 * in fts_build to limit the number of stat calls. It is
938 * understood that these fields are only referenced if fts_info
939 * is set to FTS_D.
940 */
941 dev = p->fts_dev = sbp->st_dev;
942 ino = p->fts_ino = sbp->st_ino;
943 p->fts_nlink = sbp->st_nlink;
944
945 if (ISDOT(p->fts_name))
946 return (FTS_DOT);
947
948 /*
949 * Cycle detection is done by brute force when the directory
950 * is first encountered. If the tree gets deep enough or the
951 * number of symbolic links to directories is high enough,
952 * something faster might be worthwhile.
953 */
954 for (t = p->fts_parent;
955 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
956 if (ino == t->fts_ino && dev == t->fts_dev) {
957 p->fts_cycle = t;
958 return (FTS_DC);
959 }
960 return (FTS_D);
961 }
962 if (S_ISLNK(sbp->st_mode))
963 return (FTS_SL);
964 if (S_ISREG(sbp->st_mode))
965 return (FTS_F);
966 return (FTS_DEFAULT);
967 }
968
969 /*
970 * The comparison function takes pointers to pointers to FTSENT structures.
971 * Qsort wants a comparison function that takes pointers to void.
972 * (Both with appropriate levels of const-poisoning, of course!)
973 * Use a trampoline function to deal with the difference.
974 */
975 static int
fts_compar(const void * a,const void * b)976 fts_compar(const void *a, const void *b)
977 {
978 FTS *parent;
979
980 parent = (*(const FTSENT * const *)a)->fts_fts;
981 return (*parent->fts_compar)(a, b);
982 }
983
984 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,int nitems)985 fts_sort(FTS *sp, FTSENT *head, int nitems)
986 {
987 FTSENT **ap, *p;
988
989 /*
990 * Construct an array of pointers to the structures and call qsort(3).
991 * Reassemble the array in the order returned by qsort. If unable to
992 * sort for memory reasons, return the directory entries in their
993 * current order. Allocate enough space for the current needs plus
994 * 40 so don't realloc one entry at a time.
995 */
996 if (nitems > sp->fts_nitems) {
997 sp->fts_nitems = nitems + 40;
998 if ((sp->fts_array = reallocf(sp->fts_array,
999 sp->fts_nitems * sizeof(FTSENT *))) == NULL) {
1000 sp->fts_nitems = 0;
1001 return (head);
1002 }
1003 }
1004 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1005 *ap++ = p;
1006 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar);
1007 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1008 ap[0]->fts_link = ap[1];
1009 ap[0]->fts_link = NULL;
1010 return (head);
1011 }
1012
1013 static FTSENT *
fts_alloc(FTS * sp,char * name,int namelen)1014 fts_alloc(FTS *sp, char *name, int namelen)
1015 {
1016 FTSENT *p;
1017 size_t len;
1018
1019 struct ftsent_withstat {
1020 FTSENT ent;
1021 struct stat statbuf;
1022 };
1023
1024 /*
1025 * The file name is a variable length array and no stat structure is
1026 * necessary if the user has set the nostat bit. Allocate the FTSENT
1027 * structure, the file name and the stat structure in one chunk, but
1028 * be careful that the stat structure is reasonably aligned.
1029 */
1030 if (ISSET(FTS_NOSTAT))
1031 len = sizeof(FTSENT) + namelen + 1;
1032 else
1033 len = sizeof(struct ftsent_withstat) + namelen + 1;
1034
1035 if ((p = malloc(len)) == NULL)
1036 return (NULL);
1037
1038 if (ISSET(FTS_NOSTAT)) {
1039 p->fts_name = (char *)(p + 1);
1040 p->fts_statp = NULL;
1041 } else {
1042 p->fts_name = (char *)((struct ftsent_withstat *)p + 1);
1043 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf;
1044 }
1045
1046 /* Copy the name and guarantee NUL termination. */
1047 memcpy(p->fts_name, name, namelen);
1048 p->fts_name[namelen] = '\0';
1049 p->fts_namelen = namelen;
1050 p->fts_path = sp->fts_path;
1051 p->fts_errno = 0;
1052 p->fts_flags = 0;
1053 p->fts_instr = FTS_NOINSTR;
1054 p->fts_number = 0;
1055 p->fts_pointer = NULL;
1056 p->fts_fts = sp;
1057 return (p);
1058 }
1059
1060 static void
fts_lfree(FTSENT * head)1061 fts_lfree(FTSENT *head)
1062 {
1063 FTSENT *p;
1064
1065 /* Free a linked list of structures. */
1066 while ((p = head)) {
1067 head = head->fts_link;
1068 free(p);
1069 }
1070 }
1071
1072 /*
1073 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
1074 * Most systems will allow creation of paths much longer than MAXPATHLEN, even
1075 * though the kernel won't resolve them. Add the size (not just what's needed)
1076 * plus 256 bytes so don't realloc the path 2 bytes at a time.
1077 */
1078 static int
fts_palloc(FTS * sp,size_t more)1079 fts_palloc(FTS *sp, size_t more)
1080 {
1081
1082 sp->fts_pathlen += more + 256;
1083 /*
1084 * Check for possible wraparound. In an FTS, fts_pathlen is
1085 * a signed int but in an FTSENT it is an unsigned short.
1086 * We limit fts_pathlen to USHRT_MAX to be safe in both cases.
1087 */
1088 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) {
1089 if (sp->fts_path)
1090 free(sp->fts_path);
1091 sp->fts_path = NULL;
1092 errno = ENAMETOOLONG;
1093 return (1);
1094 }
1095 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen);
1096 return (sp->fts_path == NULL);
1097 }
1098
1099 /*
1100 * When the path is realloc'd, have to fix all of the pointers in structures
1101 * already returned.
1102 */
1103 static void
fts_padjust(FTS * sp,FTSENT * head)1104 fts_padjust(FTS *sp, FTSENT *head)
1105 {
1106 FTSENT *p;
1107 char *addr = sp->fts_path;
1108
1109 #define ADJUST(p) do { \
1110 if ((p)->fts_accpath != (p)->fts_name) { \
1111 (p)->fts_accpath = \
1112 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
1113 } \
1114 (p)->fts_path = addr; \
1115 } while (0)
1116 /* Adjust the current set of children. */
1117 for (p = sp->fts_child; p; p = p->fts_link)
1118 ADJUST(p);
1119
1120 /* Adjust the rest of the tree, including the current level. */
1121 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1122 ADJUST(p);
1123 p = p->fts_link ? p->fts_link : p->fts_parent;
1124 }
1125 }
1126
1127 static size_t
fts_maxarglen(char * const * argv)1128 fts_maxarglen(char * const *argv)
1129 {
1130 size_t len, max;
1131
1132 for (max = 0; *argv; ++argv)
1133 if ((len = strlen(*argv)) > max)
1134 max = len;
1135 return (max + 1);
1136 }
1137
1138 /*
1139 * Change to dir specified by fd or p->fts_accpath without getting
1140 * tricked by someone changing the world out from underneath us.
1141 * Assumes p->fts_dev and p->fts_ino are filled in.
1142 */
1143 static int
fts_safe_changedir(FTS * sp,FTSENT * p,int fd,char * path)1144 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
1145 {
1146 int ret, oerrno, newfd;
1147 struct stat sb;
1148
1149 newfd = fd;
1150 if (ISSET(FTS_NOCHDIR))
1151 return (0);
1152 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_CLOEXEC, 0)) < 0)
1153 return (-1);
1154 if (_fstat(newfd, &sb)) {
1155 ret = -1;
1156 goto bail;
1157 }
1158 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1159 errno = ENOENT; /* disinformation */
1160 ret = -1;
1161 goto bail;
1162 }
1163 ret = fchdir(newfd);
1164 bail:
1165 oerrno = errno;
1166 if (fd < 0)
1167 (void)_close(newfd);
1168 errno = oerrno;
1169 return (ret);
1170 }
1171
1172 /*
1173 * Check if the filesystem for "ent" has UFS-style links.
1174 */
1175 static int
fts_ufslinks(FTS * sp,const FTSENT * ent)1176 fts_ufslinks(FTS *sp, const FTSENT *ent)
1177 {
1178 struct _fts_private *priv;
1179 const char **cpp;
1180
1181 priv = (struct _fts_private *)sp;
1182 /*
1183 * If this node's device is different from the previous, grab
1184 * the filesystem information, and decide on the reliability
1185 * of the link information from this filesystem for stat(2)
1186 * avoidance.
1187 */
1188 if (priv->ftsp_dev != ent->fts_dev) {
1189 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) {
1190 priv->ftsp_dev = ent->fts_dev;
1191 priv->ftsp_linksreliable = 0;
1192 for (cpp = ufslike_filesystems; *cpp; cpp++) {
1193 if (strcmp(priv->ftsp_statfs.f_fstypename,
1194 *cpp) == 0) {
1195 priv->ftsp_linksreliable = 1;
1196 break;
1197 }
1198 }
1199 } else {
1200 priv->ftsp_linksreliable = 0;
1201 }
1202 }
1203 return (priv->ftsp_linksreliable);
1204 }
1205
1206 __sym_compat(fts_open, __fts_open_44bsd, FBSD_1.0);
1207 __sym_compat(fts_close, __fts_close_44bsd, FBSD_1.0);
1208 __sym_compat(fts_read, __fts_read_44bsd, FBSD_1.0);
1209 __sym_compat(fts_set, __fts_set_44bsd, FBSD_1.0);
1210 __sym_compat(fts_children, __fts_children_44bsd, FBSD_1.0);
1211 __sym_compat(fts_get_clientptr, __fts_get_clientptr_44bsd, FBSD_1.0);
1212 __sym_compat(fts_get_stream, __fts_get_stream_44bsd, FBSD_1.0);
1213 __sym_compat(fts_set_clientptr, __fts_set_clientptr_44bsd, FBSD_1.0);
1214