1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * From: $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $
31 */
32
33 #include "namespace.h"
34 #include <sys/param.h>
35 #define _WANT_FREEBSD11_STATFS
36 #include <sys/mount.h>
37 #define _WANT_FREEBSD11_STAT
38 #include <sys/stat.h>
39
40 #define _WANT_FREEBSD11_DIRENT
41 #include <dirent.h>
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include "gen-compat.h"
48 #include "fts-compat.h"
49 #include "un-namespace.h"
50
51 #include "gen-private.h"
52
53 FTSENT *__fts_children_44bsd(FTS *, int);
54 int __fts_close_44bsd(FTS *);
55 void *__fts_get_clientptr_44bsd(FTS *);
56 FTS *__fts_get_stream_44bsd(FTSENT *);
57 FTS *__fts_open_44bsd(char * const *, int,
58 int (*)(const FTSENT * const *, const FTSENT * const *));
59 FTSENT *__fts_read_44bsd(FTS *);
60 int __fts_set_44bsd(FTS *, FTSENT *, int);
61 void __fts_set_clientptr_44bsd(FTS *, void *);
62
63 static FTSENT *fts_alloc(FTS *, char *, int);
64 static FTSENT *fts_build(FTS *, int);
65 static void fts_lfree(FTSENT *);
66 static void fts_load(FTS *, FTSENT *);
67 static size_t fts_maxarglen(char * const *);
68 static void fts_padjust(FTS *, FTSENT *);
69 static int fts_palloc(FTS *, size_t);
70 static FTSENT *fts_sort(FTS *, FTSENT *, int);
71 static u_short fts_stat(FTS *, FTSENT *, int);
72 static int fts_safe_changedir(FTS *, FTSENT *, int, char *);
73 static int fts_ufslinks(FTS *, const FTSENT *);
74
75 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
76
77 #define CLR(opt) (sp->fts_options &= ~(opt))
78 #define ISSET(opt) (sp->fts_options & (opt))
79 #define SET(opt) (sp->fts_options |= (opt))
80
81 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
82
83 /* fts_build flags */
84 #define BCHILD 1 /* fts_children */
85 #define BNAMES 2 /* fts_children, names only */
86 #define BREAD 3 /* fts_read */
87
88 /*
89 * Internal representation of an FTS, including extra implementation
90 * details. The FTS returned from fts_open points to this structure's
91 * ftsp_fts member (and can be cast to an _fts_private as required)
92 */
93 struct _fts_private {
94 FTS ftsp_fts;
95 struct freebsd11_statfs ftsp_statfs;
96 uint32_t ftsp_dev;
97 int ftsp_linksreliable;
98 };
99
100 /*
101 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it
102 * knows that a directory could not possibly have subdirectories. This
103 * is decided by looking at the link count: a subdirectory would
104 * increment its parent's link count by virtue of its own ".." entry.
105 * This assumption only holds for UFS-like filesystems that implement
106 * links and directories this way, so we must punt for others.
107 */
108
109 static const char *ufslike_filesystems[] = {
110 "ufs",
111 "zfs",
112 "nfs",
113 "ext2fs",
114 0
115 };
116
117 FTS *
__fts_open_44bsd(char * const * argv,int options,int (* compar)(const FTSENT * const *,const FTSENT * const *))118 __fts_open_44bsd(char * const *argv, int options,
119 int (*compar)(const FTSENT * const *, const FTSENT * const *))
120 {
121 struct _fts_private *priv;
122 FTS *sp;
123 FTSENT *p, *root;
124 int nitems;
125 FTSENT *parent, *tmp;
126 int len;
127
128 /* Options check. */
129 if (options & ~FTS_OPTIONMASK) {
130 errno = EINVAL;
131 return (NULL);
132 }
133
134 /* Allocate/initialize the stream. */
135 if ((priv = calloc(1, sizeof(*priv))) == NULL)
136 return (NULL);
137 sp = &priv->ftsp_fts;
138 sp->fts_compar = compar;
139 sp->fts_options = options;
140
141 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
142 if (ISSET(FTS_LOGICAL))
143 SET(FTS_NOCHDIR);
144
145 /*
146 * Start out with 1K of path space, and enough, in any case,
147 * to hold the user's paths.
148 */
149 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
150 goto mem1;
151
152 /* Allocate/initialize root's parent. */
153 if ((parent = fts_alloc(sp, "", 0)) == NULL)
154 goto mem2;
155 parent->fts_level = FTS_ROOTPARENTLEVEL;
156
157 /* Shush, GCC. */
158 tmp = NULL;
159
160 /* Allocate/initialize root(s). */
161 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
162 /* Don't allow zero-length paths. */
163 if ((len = strlen(*argv)) == 0) {
164 errno = ENOENT;
165 goto mem3;
166 }
167
168 p = fts_alloc(sp, *argv, len);
169 p->fts_level = FTS_ROOTLEVEL;
170 p->fts_parent = parent;
171 p->fts_accpath = p->fts_name;
172 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
173
174 /* Command-line "." and ".." are real directories. */
175 if (p->fts_info == FTS_DOT)
176 p->fts_info = FTS_D;
177
178 /*
179 * If comparison routine supplied, traverse in sorted
180 * order; otherwise traverse in the order specified.
181 */
182 if (compar) {
183 p->fts_link = root;
184 root = p;
185 } else {
186 p->fts_link = NULL;
187 if (root == NULL)
188 tmp = root = p;
189 else {
190 tmp->fts_link = p;
191 tmp = p;
192 }
193 }
194 }
195 if (compar && nitems > 1)
196 root = fts_sort(sp, root, nitems);
197
198 /*
199 * Allocate a dummy pointer and make fts_read think that we've just
200 * finished the node before the root(s); set p->fts_info to FTS_INIT
201 * so that everything about the "current" node is ignored.
202 */
203 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
204 goto mem3;
205 sp->fts_cur->fts_link = root;
206 sp->fts_cur->fts_info = FTS_INIT;
207
208 /*
209 * If using chdir(2), grab a file descriptor pointing to dot to ensure
210 * that we can get back here; this could be avoided for some paths,
211 * but almost certainly not worth the effort. Slashes, symbolic links,
212 * and ".." are all fairly nasty problems. Note, if we can't get the
213 * descriptor we run anyway, just more slowly.
214 */
215 if (!ISSET(FTS_NOCHDIR) &&
216 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
217 SET(FTS_NOCHDIR);
218
219 return (sp);
220
221 mem3: fts_lfree(root);
222 free(parent);
223 mem2: free(sp->fts_path);
224 mem1: free(sp);
225 return (NULL);
226 }
227
228 static void
fts_load(FTS * sp,FTSENT * p)229 fts_load(FTS *sp, FTSENT *p)
230 {
231 int len;
232 char *cp;
233
234 /*
235 * Load the stream structure for the next traversal. Since we don't
236 * actually enter the directory until after the preorder visit, set
237 * the fts_accpath field specially so the chdir gets done to the right
238 * place and the user can access the first node. From fts_open it's
239 * known that the path will fit.
240 */
241 len = p->fts_pathlen = p->fts_namelen;
242 memmove(sp->fts_path, p->fts_name, len + 1);
243 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
244 len = strlen(++cp);
245 memmove(p->fts_name, cp, len + 1);
246 p->fts_namelen = len;
247 }
248 p->fts_accpath = p->fts_path = sp->fts_path;
249 sp->fts_dev = p->fts_dev;
250 }
251
252 int
__fts_close_44bsd(FTS * sp)253 __fts_close_44bsd(FTS *sp)
254 {
255 FTSENT *freep, *p;
256 int saved_errno;
257
258 /*
259 * This still works if we haven't read anything -- the dummy structure
260 * points to the root list, so we step through to the end of the root
261 * list which has a valid parent pointer.
262 */
263 if (sp->fts_cur) {
264 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
265 freep = p;
266 p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
267 free(freep);
268 }
269 free(p);
270 }
271
272 /* Free up child linked list, sort array, path buffer. */
273 if (sp->fts_child)
274 fts_lfree(sp->fts_child);
275 if (sp->fts_array)
276 free(sp->fts_array);
277 free(sp->fts_path);
278
279 /* Return to original directory, save errno if necessary. */
280 if (!ISSET(FTS_NOCHDIR)) {
281 saved_errno = fchdir(sp->fts_rfd) ? errno : 0;
282 (void)_close(sp->fts_rfd);
283
284 /* Set errno and return. */
285 if (saved_errno != 0) {
286 /* Free up the stream pointer. */
287 free(sp);
288 errno = saved_errno;
289 return (-1);
290 }
291 }
292
293 /* Free up the stream pointer. */
294 free(sp);
295 return (0);
296 }
297
298 /*
299 * Special case of "/" at the end of the path so that slashes aren't
300 * appended which would cause paths to be written as "....//foo".
301 */
302 #define NAPPEND(p) \
303 (p->fts_path[p->fts_pathlen - 1] == '/' \
304 ? p->fts_pathlen - 1 : p->fts_pathlen)
305
306 FTSENT *
__fts_read_44bsd(FTS * sp)307 __fts_read_44bsd(FTS *sp)
308 {
309 FTSENT *p, *tmp;
310 int instr;
311 char *t;
312 int saved_errno;
313
314 /* If finished or unrecoverable error, return NULL. */
315 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
316 return (NULL);
317
318 /* Set current node pointer. */
319 p = sp->fts_cur;
320
321 /* Save and zero out user instructions. */
322 instr = p->fts_instr;
323 p->fts_instr = FTS_NOINSTR;
324
325 /* Any type of file may be re-visited; re-stat and re-turn. */
326 if (instr == FTS_AGAIN) {
327 p->fts_info = fts_stat(sp, p, 0);
328 return (p);
329 }
330
331 /*
332 * Following a symlink -- SLNONE test allows application to see
333 * SLNONE and recover. If indirecting through a symlink, have
334 * keep a pointer to current location. If unable to get that
335 * pointer, follow fails.
336 */
337 if (instr == FTS_FOLLOW &&
338 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
339 p->fts_info = fts_stat(sp, p, 1);
340 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
341 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC,
342 0)) < 0) {
343 p->fts_errno = errno;
344 p->fts_info = FTS_ERR;
345 } else
346 p->fts_flags |= FTS_SYMFOLLOW;
347 }
348 return (p);
349 }
350
351 /* Directory in pre-order. */
352 if (p->fts_info == FTS_D) {
353 /* If skipped or crossed mount point, do post-order visit. */
354 if (instr == FTS_SKIP ||
355 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
356 if (p->fts_flags & FTS_SYMFOLLOW)
357 (void)_close(p->fts_symfd);
358 if (sp->fts_child) {
359 fts_lfree(sp->fts_child);
360 sp->fts_child = NULL;
361 }
362 p->fts_info = FTS_DP;
363 return (p);
364 }
365
366 /* Rebuild if only read the names and now traversing. */
367 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
368 CLR(FTS_NAMEONLY);
369 fts_lfree(sp->fts_child);
370 sp->fts_child = NULL;
371 }
372
373 /*
374 * Cd to the subdirectory.
375 *
376 * If have already read and now fail to chdir, whack the list
377 * to make the names come out right, and set the parent errno
378 * so the application will eventually get an error condition.
379 * Set the FTS_DONTCHDIR flag so that when we logically change
380 * directories back to the parent we don't do a chdir.
381 *
382 * If haven't read do so. If the read fails, fts_build sets
383 * FTS_STOP or the fts_info field of the node.
384 */
385 if (sp->fts_child != NULL) {
386 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
387 p->fts_errno = errno;
388 p->fts_flags |= FTS_DONTCHDIR;
389 for (p = sp->fts_child; p != NULL;
390 p = p->fts_link)
391 p->fts_accpath =
392 p->fts_parent->fts_accpath;
393 }
394 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
395 if (ISSET(FTS_STOP))
396 return (NULL);
397 return (p);
398 }
399 p = sp->fts_child;
400 sp->fts_child = NULL;
401 goto name;
402 }
403
404 /* Move to the next node on this level. */
405 next: tmp = p;
406 if ((p = p->fts_link) != NULL) {
407 free(tmp);
408
409 /*
410 * If reached the top, return to the original directory (or
411 * the root of the tree), and load the paths for the next root.
412 */
413 if (p->fts_level == FTS_ROOTLEVEL) {
414 if (FCHDIR(sp, sp->fts_rfd)) {
415 SET(FTS_STOP);
416 return (NULL);
417 }
418 fts_load(sp, p);
419 return (sp->fts_cur = p);
420 }
421
422 /*
423 * User may have called fts_set on the node. If skipped,
424 * ignore. If followed, get a file descriptor so we can
425 * get back if necessary.
426 */
427 if (p->fts_instr == FTS_SKIP)
428 goto next;
429 if (p->fts_instr == FTS_FOLLOW) {
430 p->fts_info = fts_stat(sp, p, 1);
431 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
432 if ((p->fts_symfd =
433 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) {
434 p->fts_errno = errno;
435 p->fts_info = FTS_ERR;
436 } else
437 p->fts_flags |= FTS_SYMFOLLOW;
438 }
439 p->fts_instr = FTS_NOINSTR;
440 }
441
442 name: t = sp->fts_path + NAPPEND(p->fts_parent);
443 *t++ = '/';
444 memmove(t, p->fts_name, p->fts_namelen + 1);
445 return (sp->fts_cur = p);
446 }
447
448 /* Move up to the parent node. */
449 p = tmp->fts_parent;
450 free(tmp);
451
452 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
453 /*
454 * Done; free everything up and set errno to 0 so the user
455 * can distinguish between error and EOF.
456 */
457 free(p);
458 errno = 0;
459 return (sp->fts_cur = NULL);
460 }
461
462 /* NUL terminate the pathname. */
463 sp->fts_path[p->fts_pathlen] = '\0';
464
465 /*
466 * Return to the parent directory. If at a root node or came through
467 * a symlink, go back through the file descriptor. Otherwise, cd up
468 * one directory.
469 */
470 if (p->fts_level == FTS_ROOTLEVEL) {
471 if (FCHDIR(sp, sp->fts_rfd)) {
472 SET(FTS_STOP);
473 return (NULL);
474 }
475 } else if (p->fts_flags & FTS_SYMFOLLOW) {
476 if (FCHDIR(sp, p->fts_symfd)) {
477 saved_errno = errno;
478 (void)_close(p->fts_symfd);
479 errno = saved_errno;
480 SET(FTS_STOP);
481 return (NULL);
482 }
483 (void)_close(p->fts_symfd);
484 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
485 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
486 SET(FTS_STOP);
487 return (NULL);
488 }
489 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
490 return (sp->fts_cur = p);
491 }
492
493 /*
494 * Fts_set takes the stream as an argument although it's not used in this
495 * implementation; it would be necessary if anyone wanted to add global
496 * semantics to fts using fts_set. An error return is allowed for similar
497 * reasons.
498 */
499 /* ARGSUSED */
500 int
__fts_set_44bsd(FTS * sp,FTSENT * p,int instr)501 __fts_set_44bsd(FTS *sp, FTSENT *p, int instr)
502 {
503 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
504 instr != FTS_NOINSTR && instr != FTS_SKIP) {
505 errno = EINVAL;
506 return (1);
507 }
508 p->fts_instr = instr;
509 return (0);
510 }
511
512 FTSENT *
__fts_children_44bsd(FTS * sp,int instr)513 __fts_children_44bsd(FTS *sp, int instr)
514 {
515 FTSENT *p;
516 int fd;
517
518 if (instr != 0 && instr != FTS_NAMEONLY) {
519 errno = EINVAL;
520 return (NULL);
521 }
522
523 /* Set current node pointer. */
524 p = sp->fts_cur;
525
526 /*
527 * Errno set to 0 so user can distinguish empty directory from
528 * an error.
529 */
530 errno = 0;
531
532 /* Fatal errors stop here. */
533 if (ISSET(FTS_STOP))
534 return (NULL);
535
536 /* Return logical hierarchy of user's arguments. */
537 if (p->fts_info == FTS_INIT)
538 return (p->fts_link);
539
540 /*
541 * If not a directory being visited in pre-order, stop here. Could
542 * allow FTS_DNR, assuming the user has fixed the problem, but the
543 * same effect is available with FTS_AGAIN.
544 */
545 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
546 return (NULL);
547
548 /* Free up any previous child list. */
549 if (sp->fts_child != NULL)
550 fts_lfree(sp->fts_child);
551
552 if (instr == FTS_NAMEONLY) {
553 SET(FTS_NAMEONLY);
554 instr = BNAMES;
555 } else
556 instr = BCHILD;
557
558 /*
559 * If using chdir on a relative path and called BEFORE fts_read does
560 * its chdir to the root of a traversal, we can lose -- we need to
561 * chdir into the subdirectory, and we don't know where the current
562 * directory is, so we can't get back so that the upcoming chdir by
563 * fts_read will work.
564 */
565 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
566 ISSET(FTS_NOCHDIR))
567 return (sp->fts_child = fts_build(sp, instr));
568
569 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
570 return (NULL);
571 sp->fts_child = fts_build(sp, instr);
572 if (fchdir(fd)) {
573 (void)_close(fd);
574 return (NULL);
575 }
576 (void)_close(fd);
577 return (sp->fts_child);
578 }
579
580 #ifndef fts_get_clientptr
581 #error "fts_get_clientptr not defined"
582 #endif
583
584 void *
585 (__fts_get_clientptr_44bsd)(FTS *sp)
586 {
587
588 return (fts_get_clientptr(sp));
589 }
590
591 #ifndef fts_get_stream
592 #error "fts_get_stream not defined"
593 #endif
594
595 FTS *
596 (__fts_get_stream_44bsd)(FTSENT *p)
597 {
598 return (fts_get_stream(p));
599 }
600
601 void
__fts_set_clientptr_44bsd(FTS * sp,void * clientptr)602 __fts_set_clientptr_44bsd(FTS *sp, void *clientptr)
603 {
604
605 sp->fts_clientptr = clientptr;
606 }
607
608 static struct freebsd11_dirent *
fts_safe_readdir(DIR * dirp,int * readdir_errno)609 fts_safe_readdir(DIR *dirp, int *readdir_errno)
610 {
611 struct freebsd11_dirent *ret;
612
613 errno = 0;
614 if (!dirp)
615 return (NULL);
616 ret = freebsd11_readdir(dirp);
617 *readdir_errno = errno;
618 return (ret);
619 }
620
621 /*
622 * This is the tricky part -- do not casually change *anything* in here. The
623 * idea is to build the linked list of entries that are used by fts_children
624 * and fts_read. There are lots of special cases.
625 *
626 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
627 * set and it's a physical walk (so that symbolic links can't be directories),
628 * we can do things quickly. First, if it's a 4.4BSD file system, the type
629 * of the file is in the directory entry. Otherwise, we assume that the number
630 * of subdirectories in a node is equal to the number of links to the parent.
631 * The former skips all stat calls. The latter skips stat calls in any leaf
632 * directories and for any files after the subdirectories in the directory have
633 * been found, cutting the stat calls by about 2/3.
634 */
635 static FTSENT *
fts_build(FTS * sp,int type)636 fts_build(FTS *sp, int type)
637 {
638 struct freebsd11_dirent *dp;
639 FTSENT *p, *head;
640 int nitems;
641 FTSENT *cur, *tail;
642 DIR *dirp;
643 void *oldaddr;
644 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno,
645 nostat, doadjust, dnamlen, readdir_errno;
646 char *cp;
647
648 /* Set current node pointer. */
649 cur = sp->fts_cur;
650
651 /*
652 * Open the directory for reading. If this fails, we're done.
653 * If being called from fts_read, set the fts_info field.
654 */
655 #ifdef FTS_WHITEOUT
656 if (ISSET(FTS_WHITEOUT))
657 oflag = DTF_NODUP;
658 else
659 oflag = DTF_HIDEW | DTF_NODUP;
660 #else
661 #define __opendir2(path, flag) opendir(path)
662 #endif
663 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
664 if (type == BREAD) {
665 cur->fts_info = FTS_DNR;
666 cur->fts_errno = errno;
667 }
668 return (NULL);
669 }
670
671 /*
672 * Nlinks is the number of possible entries of type directory in the
673 * directory if we're cheating on stat calls, 0 if we're not doing
674 * any stat calls at all, -1 if we're doing stats on everything.
675 */
676 if (type == BNAMES) {
677 nlinks = 0;
678 /* Be quiet about nostat, GCC. */
679 nostat = 0;
680 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
681 if (fts_ufslinks(sp, cur))
682 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
683 else
684 nlinks = -1;
685 nostat = 1;
686 } else {
687 nlinks = -1;
688 nostat = 0;
689 }
690
691 #ifdef notdef
692 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
693 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
694 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
695 #endif
696 /*
697 * If we're going to need to stat anything or we want to descend
698 * and stay in the directory, chdir. If this fails we keep going,
699 * but set a flag so we don't chdir after the post-order visit.
700 * We won't be able to stat anything, but we can still return the
701 * names themselves. Note, that since fts_read won't be able to
702 * chdir into the directory, it will have to return different path
703 * names than before, i.e. "a/b" instead of "b". Since the node
704 * has already been visited in pre-order, have to wait until the
705 * post-order visit to return the error. There is a special case
706 * here, if there was nothing to stat then it's not an error to
707 * not be able to stat. This is all fairly nasty. If a program
708 * needed sorted entries or stat information, they had better be
709 * checking FTS_NS on the returned nodes.
710 */
711 cderrno = 0;
712 if (nlinks || type == BREAD) {
713 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) {
714 if (nlinks && type == BREAD)
715 cur->fts_errno = errno;
716 cur->fts_flags |= FTS_DONTCHDIR;
717 descend = 0;
718 cderrno = errno;
719 } else
720 descend = 1;
721 } else
722 descend = 0;
723
724 /*
725 * Figure out the max file name length that can be stored in the
726 * current path -- the inner loop allocates more path as necessary.
727 * We really wouldn't have to do the maxlen calculations here, we
728 * could do them in fts_read before returning the path, but it's a
729 * lot easier here since the length is part of the dirent structure.
730 *
731 * If not changing directories set a pointer so that can just append
732 * each new name into the path.
733 */
734 len = NAPPEND(cur);
735 if (ISSET(FTS_NOCHDIR)) {
736 cp = sp->fts_path + len;
737 *cp++ = '/';
738 } else {
739 /* GCC, you're too verbose. */
740 cp = NULL;
741 }
742 len++;
743 maxlen = sp->fts_pathlen - len;
744
745 level = cur->fts_level + 1;
746
747 /* Read the directory, attaching each entry to the `link' pointer. */
748 doadjust = 0;
749 readdir_errno = 0;
750 for (head = tail = NULL, nitems = 0;
751 (dp = fts_safe_readdir(dirp, &readdir_errno));) {
752 dnamlen = dp->d_namlen;
753 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
754 continue;
755
756 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL)
757 goto mem1;
758 if (dnamlen >= maxlen) { /* include space for NUL */
759 oldaddr = sp->fts_path;
760 if (fts_palloc(sp, dnamlen + len + 1)) {
761 /*
762 * No more memory for path or structures. Save
763 * errno, free up the current structure and the
764 * structures already allocated.
765 */
766 mem1: saved_errno = errno;
767 if (p)
768 free(p);
769 fts_lfree(head);
770 (void)closedir(dirp);
771 cur->fts_info = FTS_ERR;
772 SET(FTS_STOP);
773 errno = saved_errno;
774 return (NULL);
775 }
776 /* Did realloc() change the pointer? */
777 if (oldaddr != sp->fts_path) {
778 doadjust = 1;
779 if (ISSET(FTS_NOCHDIR))
780 cp = sp->fts_path + len;
781 }
782 maxlen = sp->fts_pathlen - len;
783 }
784
785 if (len + dnamlen >= USHRT_MAX) {
786 /*
787 * In an FTSENT, fts_pathlen is a u_short so it is
788 * possible to wraparound here. If we do, free up
789 * the current structure and the structures already
790 * allocated, then error out with ENAMETOOLONG.
791 */
792 free(p);
793 fts_lfree(head);
794 (void)closedir(dirp);
795 cur->fts_info = FTS_ERR;
796 SET(FTS_STOP);
797 errno = ENAMETOOLONG;
798 return (NULL);
799 }
800 p->fts_level = level;
801 p->fts_parent = sp->fts_cur;
802 p->fts_pathlen = len + dnamlen;
803
804 #ifdef FTS_WHITEOUT
805 if (dp->d_type == DT_WHT)
806 p->fts_flags |= FTS_ISW;
807 #endif
808
809 if (cderrno) {
810 if (nlinks) {
811 p->fts_info = FTS_NS;
812 p->fts_errno = cderrno;
813 } else
814 p->fts_info = FTS_NSOK;
815 p->fts_accpath = cur->fts_accpath;
816 } else if (nlinks == 0
817 #ifdef DT_DIR
818 || (nostat &&
819 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
820 #endif
821 ) {
822 p->fts_accpath =
823 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
824 p->fts_info = FTS_NSOK;
825 } else {
826 /* Build a file name for fts_stat to stat. */
827 if (ISSET(FTS_NOCHDIR)) {
828 p->fts_accpath = p->fts_path;
829 memmove(cp, p->fts_name, p->fts_namelen + 1);
830 } else
831 p->fts_accpath = p->fts_name;
832 /* Stat it. */
833 p->fts_info = fts_stat(sp, p, 0);
834
835 /* Decrement link count if applicable. */
836 if (nlinks > 0 && (p->fts_info == FTS_D ||
837 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
838 --nlinks;
839 }
840
841 /* We walk in directory order so "ls -f" doesn't get upset. */
842 p->fts_link = NULL;
843 if (head == NULL)
844 head = tail = p;
845 else {
846 tail->fts_link = p;
847 tail = p;
848 }
849 ++nitems;
850 }
851
852 if (readdir_errno) {
853 cur->fts_errno = readdir_errno;
854 /*
855 * If we've not read any items yet, treat
856 * the error as if we can't access the dir.
857 */
858 cur->fts_info = nitems ? FTS_ERR : FTS_DNR;
859 }
860
861 if (dirp)
862 (void)closedir(dirp);
863
864 /*
865 * If realloc() changed the address of the path, adjust the
866 * addresses for the rest of the tree and the dir list.
867 */
868 if (doadjust)
869 fts_padjust(sp, head);
870
871 /*
872 * If not changing directories, reset the path back to original
873 * state.
874 */
875 if (ISSET(FTS_NOCHDIR)) {
876 if (len == sp->fts_pathlen || nitems == 0)
877 --cp;
878 *cp = '\0';
879 }
880
881 /*
882 * If descended after called from fts_children or after called from
883 * fts_read and nothing found, get back. At the root level we use
884 * the saved fd; if one of fts_open()'s arguments is a relative path
885 * to an empty directory, we wind up here with no other way back. If
886 * can't get back, we're done.
887 */
888 if (descend && (type == BCHILD || !nitems) &&
889 (cur->fts_level == FTS_ROOTLEVEL ?
890 FCHDIR(sp, sp->fts_rfd) :
891 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
892 cur->fts_info = FTS_ERR;
893 SET(FTS_STOP);
894 return (NULL);
895 }
896
897 /* If didn't find anything, return NULL. */
898 if (!nitems) {
899 if (type == BREAD &&
900 cur->fts_info != FTS_DNR && cur->fts_info != FTS_ERR)
901 cur->fts_info = FTS_DP;
902 return (NULL);
903 }
904
905 /* Sort the entries. */
906 if (sp->fts_compar && nitems > 1)
907 head = fts_sort(sp, head, nitems);
908 return (head);
909 }
910
911 static u_short
fts_stat(FTS * sp,FTSENT * p,int follow)912 fts_stat(FTS *sp, FTSENT *p, int follow)
913 {
914 FTSENT *t;
915 uint32_t dev;
916 uint32_t ino;
917 struct freebsd11_stat *sbp, sb;
918 int saved_errno;
919
920 /* If user needs stat info, stat buffer already allocated. */
921 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
922
923 #ifdef FTS_WHITEOUT
924 /* Check for whiteout. */
925 if (p->fts_flags & FTS_ISW) {
926 if (sbp != &sb) {
927 memset(sbp, '\0', sizeof(*sbp));
928 sbp->st_mode = S_IFWHT;
929 }
930 return (FTS_W);
931 }
932 #endif
933
934 /*
935 * If doing a logical walk, or application requested FTS_FOLLOW, do
936 * a stat(2). If that fails, check for a non-existent symlink. If
937 * fail, set the errno from the stat call.
938 */
939 if (ISSET(FTS_LOGICAL) || follow) {
940 if (freebsd11_stat(p->fts_accpath, sbp)) {
941 saved_errno = errno;
942 if (!freebsd11_lstat(p->fts_accpath, sbp)) {
943 errno = 0;
944 return (FTS_SLNONE);
945 }
946 p->fts_errno = saved_errno;
947 goto err;
948 }
949 } else if (freebsd11_lstat(p->fts_accpath, sbp)) {
950 p->fts_errno = errno;
951 err: memset(sbp, 0, sizeof(*sbp));
952 return (FTS_NS);
953 }
954
955 if (S_ISDIR(sbp->st_mode)) {
956 /*
957 * Set the device/inode. Used to find cycles and check for
958 * crossing mount points. Also remember the link count, used
959 * in fts_build to limit the number of stat calls. It is
960 * understood that these fields are only referenced if fts_info
961 * is set to FTS_D.
962 */
963 dev = p->fts_dev = sbp->st_dev;
964 ino = p->fts_ino = sbp->st_ino;
965 p->fts_nlink = sbp->st_nlink;
966
967 if (ISDOT(p->fts_name))
968 return (FTS_DOT);
969
970 /*
971 * Cycle detection is done by brute force when the directory
972 * is first encountered. If the tree gets deep enough or the
973 * number of symbolic links to directories is high enough,
974 * something faster might be worthwhile.
975 */
976 for (t = p->fts_parent;
977 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
978 if (ino == t->fts_ino && dev == t->fts_dev) {
979 p->fts_cycle = t;
980 return (FTS_DC);
981 }
982 return (FTS_D);
983 }
984 if (S_ISLNK(sbp->st_mode))
985 return (FTS_SL);
986 if (S_ISREG(sbp->st_mode))
987 return (FTS_F);
988 return (FTS_DEFAULT);
989 }
990
991 /*
992 * The comparison function takes pointers to pointers to FTSENT structures.
993 * Qsort wants a comparison function that takes pointers to void.
994 * (Both with appropriate levels of const-poisoning, of course!)
995 * Use a trampoline function to deal with the difference.
996 */
997 static int
fts_compar(const void * a,const void * b)998 fts_compar(const void *a, const void *b)
999 {
1000 FTS *parent;
1001
1002 parent = (*(const FTSENT * const *)a)->fts_fts;
1003 return (*parent->fts_compar)(a, b);
1004 }
1005
1006 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,int nitems)1007 fts_sort(FTS *sp, FTSENT *head, int nitems)
1008 {
1009 FTSENT **ap, *p;
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 sp->fts_nitems = nitems + 40;
1020 if ((sp->fts_array = reallocf(sp->fts_array,
1021 sp->fts_nitems * sizeof(FTSENT *))) == NULL) {
1022 sp->fts_nitems = 0;
1023 return (head);
1024 }
1025 }
1026 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1027 *ap++ = p;
1028 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar);
1029 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1030 ap[0]->fts_link = ap[1];
1031 ap[0]->fts_link = NULL;
1032 return (head);
1033 }
1034
1035 static FTSENT *
fts_alloc(FTS * sp,char * name,int namelen)1036 fts_alloc(FTS *sp, char *name, int namelen)
1037 {
1038 FTSENT *p;
1039 size_t len;
1040
1041 struct ftsent_withstat {
1042 FTSENT ent;
1043 struct freebsd11_stat statbuf;
1044 };
1045
1046 /*
1047 * The file name is a variable length array and no stat structure is
1048 * necessary if the user has set the nostat bit. Allocate the FTSENT
1049 * structure, the file name and the stat structure in one chunk, but
1050 * be careful that the stat structure is reasonably aligned.
1051 */
1052 if (ISSET(FTS_NOSTAT))
1053 len = sizeof(FTSENT) + namelen + 1;
1054 else
1055 len = sizeof(struct ftsent_withstat) + namelen + 1;
1056
1057 if ((p = malloc(len)) == NULL)
1058 return (NULL);
1059
1060 if (ISSET(FTS_NOSTAT)) {
1061 p->fts_name = (char *)(p + 1);
1062 p->fts_statp = NULL;
1063 } else {
1064 p->fts_name = (char *)((struct ftsent_withstat *)p + 1);
1065 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf;
1066 }
1067
1068 /* Copy the name and guarantee NUL termination. */
1069 memcpy(p->fts_name, name, namelen);
1070 p->fts_name[namelen] = '\0';
1071 p->fts_namelen = namelen;
1072 p->fts_path = sp->fts_path;
1073 p->fts_errno = 0;
1074 p->fts_flags = 0;
1075 p->fts_instr = FTS_NOINSTR;
1076 p->fts_number = 0;
1077 p->fts_pointer = NULL;
1078 p->fts_fts = sp;
1079 return (p);
1080 }
1081
1082 static void
fts_lfree(FTSENT * head)1083 fts_lfree(FTSENT *head)
1084 {
1085 FTSENT *p;
1086
1087 /* Free a linked list of structures. */
1088 while ((p = head)) {
1089 head = head->fts_link;
1090 free(p);
1091 }
1092 }
1093
1094 /*
1095 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
1096 * Most systems will allow creation of paths much longer than MAXPATHLEN, even
1097 * though the kernel won't resolve them. Add the size (not just what's needed)
1098 * plus 256 bytes so don't realloc the path 2 bytes at a time.
1099 */
1100 static int
fts_palloc(FTS * sp,size_t more)1101 fts_palloc(FTS *sp, size_t more)
1102 {
1103
1104 sp->fts_pathlen += more + 256;
1105 /*
1106 * Check for possible wraparound. In an FTS, fts_pathlen is
1107 * a signed int but in an FTSENT it is an unsigned short.
1108 * We limit fts_pathlen to USHRT_MAX to be safe in both cases.
1109 */
1110 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) {
1111 if (sp->fts_path)
1112 free(sp->fts_path);
1113 sp->fts_path = NULL;
1114 errno = ENAMETOOLONG;
1115 return (1);
1116 }
1117 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen);
1118 return (sp->fts_path == NULL);
1119 }
1120
1121 /*
1122 * When the path is realloc'd, have to fix all of the pointers in structures
1123 * already returned.
1124 */
1125 static void
fts_padjust(FTS * sp,FTSENT * head)1126 fts_padjust(FTS *sp, FTSENT *head)
1127 {
1128 FTSENT *p;
1129 char *addr = sp->fts_path;
1130
1131 #define ADJUST(p) do { \
1132 if ((p)->fts_accpath != (p)->fts_name) { \
1133 (p)->fts_accpath = \
1134 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
1135 } \
1136 (p)->fts_path = addr; \
1137 } while (0)
1138 /* Adjust the current set of children. */
1139 for (p = sp->fts_child; p; p = p->fts_link)
1140 ADJUST(p);
1141
1142 /* Adjust the rest of the tree, including the current level. */
1143 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1144 ADJUST(p);
1145 p = p->fts_link ? p->fts_link : p->fts_parent;
1146 }
1147 }
1148
1149 static size_t
fts_maxarglen(char * const * argv)1150 fts_maxarglen(char * const *argv)
1151 {
1152 size_t len, max;
1153
1154 for (max = 0; *argv; ++argv)
1155 if ((len = strlen(*argv)) > max)
1156 max = len;
1157 return (max + 1);
1158 }
1159
1160 /*
1161 * Change to dir specified by fd or p->fts_accpath without getting
1162 * tricked by someone changing the world out from underneath us.
1163 * Assumes p->fts_dev and p->fts_ino are filled in.
1164 */
1165 static int
fts_safe_changedir(FTS * sp,FTSENT * p,int fd,char * path)1166 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
1167 {
1168 int ret, oerrno, newfd;
1169 struct freebsd11_stat sb;
1170
1171 newfd = fd;
1172 if (ISSET(FTS_NOCHDIR))
1173 return (0);
1174 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_CLOEXEC, 0)) < 0)
1175 return (-1);
1176 if (freebsd11_fstat(newfd, &sb)) {
1177 ret = -1;
1178 goto bail;
1179 }
1180 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1181 errno = ENOENT; /* disinformation */
1182 ret = -1;
1183 goto bail;
1184 }
1185 ret = fchdir(newfd);
1186 bail:
1187 oerrno = errno;
1188 if (fd < 0)
1189 (void)_close(newfd);
1190 errno = oerrno;
1191 return (ret);
1192 }
1193
1194 /*
1195 * Check if the filesystem for "ent" has UFS-style links.
1196 */
1197 static int
fts_ufslinks(FTS * sp,const FTSENT * ent)1198 fts_ufslinks(FTS *sp, const FTSENT *ent)
1199 {
1200 struct _fts_private *priv;
1201 const char **cpp;
1202
1203 priv = (struct _fts_private *)sp;
1204 /*
1205 * If this node's device is different from the previous, grab
1206 * the filesystem information, and decide on the reliability
1207 * of the link information from this filesystem for stat(2)
1208 * avoidance.
1209 */
1210 if (priv->ftsp_dev != ent->fts_dev) {
1211 if (freebsd11_statfs(ent->fts_path, &priv->ftsp_statfs) != -1) {
1212 priv->ftsp_dev = ent->fts_dev;
1213 priv->ftsp_linksreliable = 0;
1214 for (cpp = ufslike_filesystems; *cpp; cpp++) {
1215 if (strcmp(priv->ftsp_statfs.f_fstypename,
1216 *cpp) == 0) {
1217 priv->ftsp_linksreliable = 1;
1218 break;
1219 }
1220 }
1221 } else {
1222 priv->ftsp_linksreliable = 0;
1223 }
1224 }
1225 return (priv->ftsp_linksreliable);
1226 }
1227
1228 __sym_compat(fts_open, __fts_open_44bsd, FBSD_1.0);
1229 __sym_compat(fts_close, __fts_close_44bsd, FBSD_1.0);
1230 __sym_compat(fts_read, __fts_read_44bsd, FBSD_1.0);
1231 __sym_compat(fts_set, __fts_set_44bsd, FBSD_1.0);
1232 __sym_compat(fts_children, __fts_children_44bsd, FBSD_1.0);
1233 __sym_compat(fts_get_clientptr, __fts_get_clientptr_44bsd, FBSD_1.0);
1234 __sym_compat(fts_get_stream, __fts_get_stream_44bsd, FBSD_1.0);
1235 __sym_compat(fts_set_clientptr, __fts_set_clientptr_44bsd, FBSD_1.0);
1236