xref: /freebsd/lib/libc/gen/fts-compat11.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
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  * 3. 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  * from: $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 #define	_WANT_FREEBSD11_STATFS
44 #include <sys/mount.h>
45 #define	_WANT_FREEBSD11_STAT
46 #include <sys/stat.h>
47 
48 #define	_WANT_FREEBSD11_DIRENT
49 #include <dirent.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <fts.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include "gen-compat.h"
57 #include "fts-compat11.h"
58 #include "un-namespace.h"
59 
60 #include "gen-private.h"
61 
62 static FTSENT11	*fts_alloc(FTS11 *, char *, size_t);
63 static FTSENT11	*fts_build(FTS11 *, int);
64 static void	 fts_lfree(FTSENT11 *);
65 static void	 fts_load(FTS11 *, FTSENT11 *);
66 static size_t	 fts_maxarglen(char * const *);
67 static void	 fts_padjust(FTS11 *, FTSENT11 *);
68 static int	 fts_palloc(FTS11 *, size_t);
69 static FTSENT11	*fts_sort(FTS11 *, FTSENT11 *, size_t);
70 static int	 fts_stat(FTS11 *, FTSENT11 *, int, int);
71 static int	 fts_safe_changedir(FTS11 *, FTSENT11 *, int, char *);
72 static int	 fts_ufslinks(FTS11 *, const FTSENT11 *);
73 
74 #define	ISDOT(a)	(a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
75 
76 #define	CLR(opt)	(sp->fts_options &= ~(opt))
77 #define	ISSET(opt)	(sp->fts_options & (opt))
78 #define	SET(opt)	(sp->fts_options |= (opt))
79 
80 #define	FCHDIR(sp, fd)	(!ISSET(FTS_NOCHDIR) && fchdir(fd))
81 
82 /* fts_build flags */
83 #define	BCHILD		1		/* fts_children */
84 #define	BNAMES		2		/* fts_children, names only */
85 #define	BREAD		3		/* fts_read */
86 
87 /*
88  * Internal representation of an FTS, including extra implementation
89  * details.  The FTS returned from fts_open points to this structure's
90  * ftsp_fts member (and can be cast to an _fts_private as required)
91  */
92 struct _fts_private11 {
93 	FTS11		ftsp_fts;
94 	struct freebsd11_statfs	ftsp_statfs;
95 	uint32_t	ftsp_dev;
96 	int		ftsp_linksreliable;
97 };
98 
99 /*
100  * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it
101  * knows that a directory could not possibly have subdirectories.  This
102  * is decided by looking at the link count: a subdirectory would
103  * increment its parent's link count by virtue of its own ".." entry.
104  * This assumption only holds for UFS-like filesystems that implement
105  * links and directories this way, so we must punt for others.
106  */
107 
108 static const char *ufslike_filesystems[] = {
109 	"ufs",
110 	"zfs",
111 	"nfs",
112 	"ext2fs",
113 	0
114 };
115 
116 FTS11 *
117 freebsd11_fts_open(char * const *argv, int options,
118     int (*compar)(const FTSENT11 * const *, const FTSENT11 * const *))
119 {
120 	struct _fts_private11 *priv;
121 	FTS11 *sp;
122 	FTSENT11 *p, *root;
123 	FTSENT11 *parent, *tmp;
124 	size_t len, nitems;
125 
126 	/* Options check. */
127 	if (options & ~FTS_OPTIONMASK) {
128 		errno = EINVAL;
129 		return (NULL);
130 	}
131 
132 	/* fts_open() requires at least one path */
133 	if (*argv == NULL) {
134 		errno = EINVAL;
135 		return (NULL);
136 	}
137 
138 	/* Allocate/initialize the stream. */
139 	if ((priv = calloc(1, sizeof(*priv))) == NULL)
140 		return (NULL);
141 	sp = &priv->ftsp_fts;
142 	sp->fts_compar = compar;
143 	sp->fts_options = options;
144 
145 	/* Logical walks turn on NOCHDIR; symbolic links are too hard. */
146 	if (ISSET(FTS_LOGICAL))
147 		SET(FTS_NOCHDIR);
148 
149 	/*
150 	 * Start out with 1K of path space, and enough, in any case,
151 	 * to hold the user's paths.
152 	 */
153 	if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
154 		goto mem1;
155 
156 	/* Allocate/initialize root's parent. */
157 	if ((parent = fts_alloc(sp, "", 0)) == NULL)
158 		goto mem2;
159 	parent->fts_level = FTS_ROOTPARENTLEVEL;
160 
161 	/* Shush, GCC. */
162 	tmp = NULL;
163 
164 	/* Allocate/initialize root(s). */
165 	for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
166 		len = strlen(*argv);
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), -1);
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
229 fts_load(FTS11 *sp, FTSENT11 *p)
230 {
231 	size_t 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
253 freebsd11_fts_close(FTS11 *sp)
254 {
255 	FTSENT11 *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 FTSENT11 *
307 freebsd11_fts_read(FTS11 *sp)
308 {
309 	FTSENT11 *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, -1);
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, -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 		/*
408 		 * If reached the top, return to the original directory (or
409 		 * the root of the tree), and load the paths for the next root.
410 		 */
411 		if (p->fts_level == FTS_ROOTLEVEL) {
412 			if (FCHDIR(sp, sp->fts_rfd)) {
413 				SET(FTS_STOP);
414 				return (NULL);
415 			}
416 			free(tmp);
417 			fts_load(sp, p);
418 			return (sp->fts_cur = p);
419 		}
420 
421 		/*
422 		 * User may have called fts_set on the node.  If skipped,
423 		 * ignore.  If followed, get a file descriptor so we can
424 		 * get back if necessary.
425 		 */
426 		if (p->fts_instr == FTS_SKIP) {
427 			free(tmp);
428 			goto next;
429 		}
430 		if (p->fts_instr == FTS_FOLLOW) {
431 			p->fts_info = fts_stat(sp, p, 1, -1);
432 			if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
433 				if ((p->fts_symfd =
434 				    _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) {
435 					p->fts_errno = errno;
436 					p->fts_info = FTS_ERR;
437 				} else
438 					p->fts_flags |= FTS_SYMFOLLOW;
439 			}
440 			p->fts_instr = FTS_NOINSTR;
441 		}
442 
443 		free(tmp);
444 
445 name:		t = sp->fts_path + NAPPEND(p->fts_parent);
446 		*t++ = '/';
447 		memmove(t, p->fts_name, p->fts_namelen + 1);
448 		return (sp->fts_cur = p);
449 	}
450 
451 	/* Move up to the parent node. */
452 	p = tmp->fts_parent;
453 
454 	if (p->fts_level == FTS_ROOTPARENTLEVEL) {
455 		/*
456 		 * Done; free everything up and set errno to 0 so the user
457 		 * can distinguish between error and EOF.
458 		 */
459 		free(tmp);
460 		free(p);
461 		errno = 0;
462 		return (sp->fts_cur = NULL);
463 	}
464 
465 	/* NUL terminate the pathname. */
466 	sp->fts_path[p->fts_pathlen] = '\0';
467 
468 	/*
469 	 * Return to the parent directory.  If at a root node or came through
470 	 * a symlink, go back through the file descriptor.  Otherwise, cd up
471 	 * one directory.
472 	 */
473 	if (p->fts_level == FTS_ROOTLEVEL) {
474 		if (FCHDIR(sp, sp->fts_rfd)) {
475 			SET(FTS_STOP);
476 			return (NULL);
477 		}
478 	} else if (p->fts_flags & FTS_SYMFOLLOW) {
479 		if (FCHDIR(sp, p->fts_symfd)) {
480 			saved_errno = errno;
481 			(void)_close(p->fts_symfd);
482 			errno = saved_errno;
483 			SET(FTS_STOP);
484 			return (NULL);
485 		}
486 		(void)_close(p->fts_symfd);
487 	} else if (!(p->fts_flags & FTS_DONTCHDIR) &&
488 	    fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
489 		SET(FTS_STOP);
490 		return (NULL);
491 	}
492 	free(tmp);
493 	p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
494 	return (sp->fts_cur = p);
495 }
496 
497 /*
498  * Fts_set takes the stream as an argument although it's not used in this
499  * implementation; it would be necessary if anyone wanted to add global
500  * semantics to fts using fts_set.  An error return is allowed for similar
501  * reasons.
502  */
503 /* ARGSUSED */
504 int
505 freebsd11_fts_set(FTS11 *sp, FTSENT11 *p, int instr)
506 {
507 	if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
508 	    instr != FTS_NOINSTR && instr != FTS_SKIP) {
509 		errno = EINVAL;
510 		return (1);
511 	}
512 	p->fts_instr = instr;
513 	return (0);
514 }
515 
516 FTSENT11 *
517 freebsd11_fts_children(FTS11 *sp, int instr)
518 {
519 	FTSENT11 *p;
520 	int fd, rc, serrno;
521 
522 	if (instr != 0 && instr != FTS_NAMEONLY) {
523 		errno = EINVAL;
524 		return (NULL);
525 	}
526 
527 	/* Set current node pointer. */
528 	p = sp->fts_cur;
529 
530 	/*
531 	 * Errno set to 0 so user can distinguish empty directory from
532 	 * an error.
533 	 */
534 	errno = 0;
535 
536 	/* Fatal errors stop here. */
537 	if (ISSET(FTS_STOP))
538 		return (NULL);
539 
540 	/* Return logical hierarchy of user's arguments. */
541 	if (p->fts_info == FTS_INIT)
542 		return (p->fts_link);
543 
544 	/*
545 	 * If not a directory being visited in pre-order, stop here.  Could
546 	 * allow FTS_DNR, assuming the user has fixed the problem, but the
547 	 * same effect is available with FTS_AGAIN.
548 	 */
549 	if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
550 		return (NULL);
551 
552 	/* Free up any previous child list. */
553 	if (sp->fts_child != NULL)
554 		fts_lfree(sp->fts_child);
555 
556 	if (instr == FTS_NAMEONLY) {
557 		SET(FTS_NAMEONLY);
558 		instr = BNAMES;
559 	} else
560 		instr = BCHILD;
561 
562 	/*
563 	 * If using chdir on a relative path and called BEFORE fts_read does
564 	 * its chdir to the root of a traversal, we can lose -- we need to
565 	 * chdir into the subdirectory, and we don't know where the current
566 	 * directory is, so we can't get back so that the upcoming chdir by
567 	 * fts_read will work.
568 	 */
569 	if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
570 	    ISSET(FTS_NOCHDIR))
571 		return (sp->fts_child = fts_build(sp, instr));
572 
573 	if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0)
574 		return (NULL);
575 	sp->fts_child = fts_build(sp, instr);
576 	serrno = (sp->fts_child == NULL) ? errno : 0;
577 	rc = fchdir(fd);
578 	if (rc < 0 && serrno == 0)
579 		serrno = errno;
580 	(void)_close(fd);
581 	errno = serrno;
582 	if (rc < 0)
583 		return (NULL);
584 	return (sp->fts_child);
585 }
586 
587 #ifndef freebsd11_fts_get_clientptr
588 #error "freebsd11_fts_get_clientptr not defined"
589 #endif
590 
591 void *
592 (freebsd11_fts_get_clientptr)(FTS11 *sp)
593 {
594 
595 	return (freebsd11_fts_get_clientptr(sp));
596 }
597 
598 #ifndef freebsd11_fts_get_stream
599 #error "freebsd11_fts_get_stream not defined"
600 #endif
601 
602 FTS11 *
603 (freebsd11_fts_get_stream)(FTSENT11 *p)
604 {
605 	return (freebsd11_fts_get_stream(p));
606 }
607 
608 void
609 freebsd11_fts_set_clientptr(FTS11 *sp, void *clientptr)
610 {
611 
612 	sp->fts_clientptr = clientptr;
613 }
614 
615 /*
616  * This is the tricky part -- do not casually change *anything* in here.  The
617  * idea is to build the linked list of entries that are used by fts_children
618  * and fts_read.  There are lots of special cases.
619  *
620  * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
621  * set and it's a physical walk (so that symbolic links can't be directories),
622  * we can do things quickly.  First, if it's a 4.4BSD file system, the type
623  * of the file is in the directory entry.  Otherwise, we assume that the number
624  * of subdirectories in a node is equal to the number of links to the parent.
625  * The former skips all stat calls.  The latter skips stat calls in any leaf
626  * directories and for any files after the subdirectories in the directory have
627  * been found, cutting the stat calls by about 2/3.
628  */
629 static FTSENT11 *
630 fts_build(FTS11 *sp, int type)
631 {
632 	struct freebsd11_dirent *dp;
633 	FTSENT11 *p, *head;
634 	FTSENT11 *cur, *tail;
635 	DIR *dirp;
636 	void *oldaddr;
637 	char *cp;
638 	int cderrno, descend, oflag, saved_errno, nostat, doadjust;
639 	long level;
640 	long nlinks;	/* has to be signed because -1 is a magic value */
641 	size_t dnamlen, len, maxlen, nitems;
642 
643 	/* Set current node pointer. */
644 	cur = sp->fts_cur;
645 
646 	/*
647 	 * Open the directory for reading.  If this fails, we're done.
648 	 * If being called from fts_read, set the fts_info field.
649 	 */
650 #ifdef FTS_WHITEOUT
651 	if (ISSET(FTS_WHITEOUT))
652 		oflag = DTF_NODUP | DTF_REWIND;
653 	else
654 		oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND;
655 #else
656 #define __opendir2(path, flag) opendir(path)
657 #endif
658 	if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
659 		if (type == BREAD) {
660 			cur->fts_info = FTS_DNR;
661 			cur->fts_errno = errno;
662 		}
663 		return (NULL);
664 	}
665 
666 	/*
667 	 * Nlinks is the number of possible entries of type directory in the
668 	 * directory if we're cheating on stat calls, 0 if we're not doing
669 	 * any stat calls at all, -1 if we're doing stats on everything.
670 	 */
671 	if (type == BNAMES) {
672 		nlinks = 0;
673 		/* Be quiet about nostat, GCC. */
674 		nostat = 0;
675 	} else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
676 		if (fts_ufslinks(sp, cur))
677 			nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
678 		else
679 			nlinks = -1;
680 		nostat = 1;
681 	} else {
682 		nlinks = -1;
683 		nostat = 0;
684 	}
685 
686 #ifdef notdef
687 	(void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
688 	(void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
689 	    ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
690 #endif
691 	/*
692 	 * If we're going to need to stat anything or we want to descend
693 	 * and stay in the directory, chdir.  If this fails we keep going,
694 	 * but set a flag so we don't chdir after the post-order visit.
695 	 * We won't be able to stat anything, but we can still return the
696 	 * names themselves.  Note, that since fts_read won't be able to
697 	 * chdir into the directory, it will have to return different path
698 	 * names than before, i.e. "a/b" instead of "b".  Since the node
699 	 * has already been visited in pre-order, have to wait until the
700 	 * post-order visit to return the error.  There is a special case
701 	 * here, if there was nothing to stat then it's not an error to
702 	 * not be able to stat.  This is all fairly nasty.  If a program
703 	 * needed sorted entries or stat information, they had better be
704 	 * checking FTS_NS on the returned nodes.
705 	 */
706 	cderrno = 0;
707 	if (nlinks || type == BREAD) {
708 		if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) {
709 			if (nlinks && type == BREAD)
710 				cur->fts_errno = errno;
711 			cur->fts_flags |= FTS_DONTCHDIR;
712 			descend = 0;
713 			cderrno = errno;
714 		} else
715 			descend = 1;
716 	} else
717 		descend = 0;
718 
719 	/*
720 	 * Figure out the max file name length that can be stored in the
721 	 * current path -- the inner loop allocates more path as necessary.
722 	 * We really wouldn't have to do the maxlen calculations here, we
723 	 * could do them in fts_read before returning the path, but it's a
724 	 * lot easier here since the length is part of the dirent structure.
725 	 *
726 	 * If not changing directories set a pointer so that can just append
727 	 * each new name into the path.
728 	 */
729 	len = NAPPEND(cur);
730 	if (ISSET(FTS_NOCHDIR)) {
731 		cp = sp->fts_path + len;
732 		*cp++ = '/';
733 	} else {
734 		/* GCC, you're too verbose. */
735 		cp = NULL;
736 	}
737 	len++;
738 	maxlen = sp->fts_pathlen - len;
739 
740 	level = cur->fts_level + 1;
741 
742 	/* Read the directory, attaching each entry to the `link' pointer. */
743 	doadjust = 0;
744 	for (head = tail = NULL, nitems = 0;
745 	    dirp && (dp = freebsd11_readdir(dirp));) {
746 		dnamlen = dp->d_namlen;
747 		if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
748 			continue;
749 
750 		if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL)
751 			goto mem1;
752 		if (dnamlen >= maxlen) {	/* include space for NUL */
753 			oldaddr = sp->fts_path;
754 			if (fts_palloc(sp, dnamlen + len + 1)) {
755 				/*
756 				 * No more memory for path or structures.  Save
757 				 * errno, free up the current structure and the
758 				 * structures already allocated.
759 				 */
760 mem1:				saved_errno = errno;
761 				if (p)
762 					free(p);
763 				fts_lfree(head);
764 				(void)closedir(dirp);
765 				cur->fts_info = FTS_ERR;
766 				SET(FTS_STOP);
767 				errno = saved_errno;
768 				return (NULL);
769 			}
770 			/* Did realloc() change the pointer? */
771 			if (oldaddr != sp->fts_path) {
772 				doadjust = 1;
773 				if (ISSET(FTS_NOCHDIR))
774 					cp = sp->fts_path + len;
775 			}
776 			maxlen = sp->fts_pathlen - len;
777 		}
778 
779 		p->fts_level = level;
780 		p->fts_parent = sp->fts_cur;
781 		p->fts_pathlen = len + dnamlen;
782 
783 #ifdef FTS_WHITEOUT
784 		if (dp->d_type == DT_WHT)
785 			p->fts_flags |= FTS_ISW;
786 #endif
787 
788 		if (cderrno) {
789 			if (nlinks) {
790 				p->fts_info = FTS_NS;
791 				p->fts_errno = cderrno;
792 			} else
793 				p->fts_info = FTS_NSOK;
794 			p->fts_accpath = cur->fts_accpath;
795 		} else if (nlinks == 0
796 #ifdef DT_DIR
797 		    || (nostat &&
798 		    dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
799 #endif
800 		    ) {
801 			p->fts_accpath =
802 			    ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
803 			p->fts_info = FTS_NSOK;
804 		} else {
805 			/* Build a file name for fts_stat to stat. */
806 			if (ISSET(FTS_NOCHDIR)) {
807 				p->fts_accpath = p->fts_path;
808 				memmove(cp, p->fts_name, p->fts_namelen + 1);
809 				p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp));
810 			} else {
811 				p->fts_accpath = p->fts_name;
812 				p->fts_info = fts_stat(sp, p, 0, -1);
813 			}
814 
815 			/* Decrement link count if applicable. */
816 			if (nlinks > 0 && (p->fts_info == FTS_D ||
817 			    p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
818 				--nlinks;
819 		}
820 
821 		/* We walk in directory order so "ls -f" doesn't get upset. */
822 		p->fts_link = NULL;
823 		if (head == NULL)
824 			head = tail = p;
825 		else {
826 			tail->fts_link = p;
827 			tail = p;
828 		}
829 		++nitems;
830 	}
831 	if (dirp)
832 		(void)closedir(dirp);
833 
834 	/*
835 	 * If realloc() changed the address of the path, adjust the
836 	 * addresses for the rest of the tree and the dir list.
837 	 */
838 	if (doadjust)
839 		fts_padjust(sp, head);
840 
841 	/*
842 	 * If not changing directories, reset the path back to original
843 	 * state.
844 	 */
845 	if (ISSET(FTS_NOCHDIR))
846 		sp->fts_path[cur->fts_pathlen] = '\0';
847 
848 	/*
849 	 * If descended after called from fts_children or after called from
850 	 * fts_read and nothing found, get back.  At the root level we use
851 	 * the saved fd; if one of fts_open()'s arguments is a relative path
852 	 * to an empty directory, we wind up here with no other way back.  If
853 	 * can't get back, we're done.
854 	 */
855 	if (descend && (type == BCHILD || !nitems) &&
856 	    (cur->fts_level == FTS_ROOTLEVEL ?
857 	    FCHDIR(sp, sp->fts_rfd) :
858 	    fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
859 		fts_lfree(head);
860 		cur->fts_info = FTS_ERR;
861 		SET(FTS_STOP);
862 		return (NULL);
863 	}
864 
865 	/* If didn't find anything, return NULL. */
866 	if (!nitems) {
867 		if (type == BREAD)
868 			cur->fts_info = FTS_DP;
869 		return (NULL);
870 	}
871 
872 	/* Sort the entries. */
873 	if (sp->fts_compar && nitems > 1)
874 		head = fts_sort(sp, head, nitems);
875 	return (head);
876 }
877 
878 static int
879 fts_stat(FTS11 *sp, FTSENT11 *p, int follow, int dfd)
880 {
881 	FTSENT11 *t;
882 	uint32_t dev;
883 	uint32_t ino;
884 	struct freebsd11_stat *sbp, sb;
885 	int saved_errno;
886 	const char *path;
887 
888 	if (dfd == -1)
889 		path = p->fts_accpath, dfd = AT_FDCWD;
890 	else
891 		path = p->fts_name;
892 
893 	/* If user needs stat info, stat buffer already allocated. */
894 	sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
895 
896 #ifdef FTS_WHITEOUT
897 	/* Check for whiteout. */
898 	if (p->fts_flags & FTS_ISW) {
899 		if (sbp != &sb) {
900 			memset(sbp, '\0', sizeof(*sbp));
901 			sbp->st_mode = S_IFWHT;
902 		}
903 		return (FTS_W);
904 	}
905 #endif
906 
907 	/*
908 	 * If doing a logical walk, or application requested FTS_FOLLOW, do
909 	 * a stat(2).  If that fails, check for a non-existent symlink.  If
910 	 * fail, set the errno from the stat call.
911 	 */
912 	if (ISSET(FTS_LOGICAL) || follow) {
913 		if (freebsd11_fstatat(dfd, path, sbp, 0)) {
914 			saved_errno = errno;
915 			if (freebsd11_fstatat(dfd, path, sbp,
916 			    AT_SYMLINK_NOFOLLOW)) {
917 				p->fts_errno = saved_errno;
918 				goto err;
919 			}
920 			errno = 0;
921 			if (S_ISLNK(sbp->st_mode))
922 				return (FTS_SLNONE);
923 		}
924 	} else if (freebsd11_fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) {
925 		p->fts_errno = errno;
926 err:		memset(sbp, 0, sizeof(*sbp));
927 		return (FTS_NS);
928 	}
929 
930 	if (S_ISDIR(sbp->st_mode)) {
931 		/*
932 		 * Set the device/inode.  Used to find cycles and check for
933 		 * crossing mount points.  Also remember the link count, used
934 		 * in fts_build to limit the number of stat calls.  It is
935 		 * understood that these fields are only referenced if fts_info
936 		 * is set to FTS_D.
937 		 */
938 		dev = p->fts_dev = sbp->st_dev;
939 		ino = p->fts_ino = sbp->st_ino;
940 		p->fts_nlink = sbp->st_nlink;
941 
942 		if (ISDOT(p->fts_name))
943 			return (FTS_DOT);
944 
945 		/*
946 		 * Cycle detection is done by brute force when the directory
947 		 * is first encountered.  If the tree gets deep enough or the
948 		 * number of symbolic links to directories is high enough,
949 		 * something faster might be worthwhile.
950 		 */
951 		for (t = p->fts_parent;
952 		    t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
953 			if (ino == t->fts_ino && dev == t->fts_dev) {
954 				p->fts_cycle = t;
955 				return (FTS_DC);
956 			}
957 		return (FTS_D);
958 	}
959 	if (S_ISLNK(sbp->st_mode))
960 		return (FTS_SL);
961 	if (S_ISREG(sbp->st_mode))
962 		return (FTS_F);
963 	return (FTS_DEFAULT);
964 }
965 
966 /*
967  * The comparison function takes pointers to pointers to FTSENT structures.
968  * Qsort wants a comparison function that takes pointers to void.
969  * (Both with appropriate levels of const-poisoning, of course!)
970  * Use a trampoline function to deal with the difference.
971  */
972 static int
973 fts_compar(const void *a, const void *b)
974 {
975 	FTS11 *parent;
976 
977 	parent = (*(const FTSENT11 * const *)a)->fts_fts;
978 	return (*parent->fts_compar)(a, b);
979 }
980 
981 static FTSENT11 *
982 fts_sort(FTS11 *sp, FTSENT11 *head, size_t nitems)
983 {
984 	FTSENT11 **ap, *p;
985 
986 	/*
987 	 * Construct an array of pointers to the structures and call qsort(3).
988 	 * Reassemble the array in the order returned by qsort.  If unable to
989 	 * sort for memory reasons, return the directory entries in their
990 	 * current order.  Allocate enough space for the current needs plus
991 	 * 40 so don't realloc one entry at a time.
992 	 */
993 	if (nitems > sp->fts_nitems) {
994 		sp->fts_nitems = nitems + 40;
995 		if ((sp->fts_array = reallocf(sp->fts_array,
996 		    sp->fts_nitems * sizeof(FTSENT11 *))) == NULL) {
997 			sp->fts_nitems = 0;
998 			return (head);
999 		}
1000 	}
1001 	for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1002 		*ap++ = p;
1003 	qsort(sp->fts_array, nitems, sizeof(FTSENT11 *), fts_compar);
1004 	for (head = *(ap = sp->fts_array); --nitems; ++ap)
1005 		ap[0]->fts_link = ap[1];
1006 	ap[0]->fts_link = NULL;
1007 	return (head);
1008 }
1009 
1010 static FTSENT11 *
1011 fts_alloc(FTS11 *sp, char *name, size_t namelen)
1012 {
1013 	FTSENT11 *p;
1014 	size_t len;
1015 
1016 	struct ftsent11_withstat {
1017 		FTSENT11	ent;
1018 		struct	freebsd11_stat statbuf;
1019 	};
1020 
1021 	/*
1022 	 * The file name is a variable length array and no stat structure is
1023 	 * necessary if the user has set the nostat bit.  Allocate the FTSENT
1024 	 * structure, the file name and the stat structure in one chunk, but
1025 	 * be careful that the stat structure is reasonably aligned.
1026 	 */
1027 	if (ISSET(FTS_NOSTAT))
1028 		len = sizeof(FTSENT11) + namelen + 1;
1029 	else
1030 		len = sizeof(struct ftsent11_withstat) + namelen + 1;
1031 
1032 	if ((p = malloc(len)) == NULL)
1033 		return (NULL);
1034 
1035 	if (ISSET(FTS_NOSTAT)) {
1036 		p->fts_name = (char *)(p + 1);
1037 		p->fts_statp = NULL;
1038 	} else {
1039 		p->fts_name = (char *)((struct ftsent11_withstat *)p + 1);
1040 		p->fts_statp = &((struct ftsent11_withstat *)p)->statbuf;
1041 	}
1042 
1043 	/* Copy the name and guarantee NUL termination. */
1044 	memcpy(p->fts_name, name, namelen);
1045 	p->fts_name[namelen] = '\0';
1046 	p->fts_namelen = namelen;
1047 	p->fts_path = sp->fts_path;
1048 	p->fts_errno = 0;
1049 	p->fts_flags = 0;
1050 	p->fts_instr = FTS_NOINSTR;
1051 	p->fts_number = 0;
1052 	p->fts_pointer = NULL;
1053 	p->fts_fts = sp;
1054 	return (p);
1055 }
1056 
1057 static void
1058 fts_lfree(FTSENT11 *head)
1059 {
1060 	FTSENT11 *p;
1061 
1062 	/* Free a linked list of structures. */
1063 	while ((p = head)) {
1064 		head = head->fts_link;
1065 		free(p);
1066 	}
1067 }
1068 
1069 /*
1070  * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
1071  * Most systems will allow creation of paths much longer than MAXPATHLEN, even
1072  * though the kernel won't resolve them.  Add the size (not just what's needed)
1073  * plus 256 bytes so don't realloc the path 2 bytes at a time.
1074  */
1075 static int
1076 fts_palloc(FTS11 *sp, size_t more)
1077 {
1078 
1079 	sp->fts_pathlen += more + 256;
1080 	sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen);
1081 	return (sp->fts_path == NULL);
1082 }
1083 
1084 /*
1085  * When the path is realloc'd, have to fix all of the pointers in structures
1086  * already returned.
1087  */
1088 static void
1089 fts_padjust(FTS11 *sp, FTSENT11 *head)
1090 {
1091 	FTSENT11 *p;
1092 	char *addr = sp->fts_path;
1093 
1094 #define	ADJUST(p) do {							\
1095 	if ((p)->fts_accpath != (p)->fts_name) {			\
1096 		(p)->fts_accpath =					\
1097 		    (char *)addr + ((p)->fts_accpath - (p)->fts_path);	\
1098 	}								\
1099 	(p)->fts_path = addr;						\
1100 } while (0)
1101 	/* Adjust the current set of children. */
1102 	for (p = sp->fts_child; p; p = p->fts_link)
1103 		ADJUST(p);
1104 
1105 	/* Adjust the rest of the tree, including the current level. */
1106 	for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1107 		ADJUST(p);
1108 		p = p->fts_link ? p->fts_link : p->fts_parent;
1109 	}
1110 }
1111 
1112 static size_t
1113 fts_maxarglen(char * const *argv)
1114 {
1115 	size_t len, max;
1116 
1117 	for (max = 0; *argv; ++argv)
1118 		if ((len = strlen(*argv)) > max)
1119 			max = len;
1120 	return (max + 1);
1121 }
1122 
1123 /*
1124  * Change to dir specified by fd or p->fts_accpath without getting
1125  * tricked by someone changing the world out from underneath us.
1126  * Assumes p->fts_dev and p->fts_ino are filled in.
1127  */
1128 static int
1129 fts_safe_changedir(FTS11 *sp, FTSENT11 *p, int fd, char *path)
1130 {
1131 	int ret, oerrno, newfd;
1132 	struct freebsd11_stat sb;
1133 
1134 	newfd = fd;
1135 	if (ISSET(FTS_NOCHDIR))
1136 		return (0);
1137 	if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY |
1138 	    O_CLOEXEC, 0)) < 0)
1139 		return (-1);
1140 	if (freebsd11_fstat(newfd, &sb)) {
1141 		ret = -1;
1142 		goto bail;
1143 	}
1144 	if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
1145 		errno = ENOENT;		/* disinformation */
1146 		ret = -1;
1147 		goto bail;
1148 	}
1149 	ret = fchdir(newfd);
1150 bail:
1151 	oerrno = errno;
1152 	if (fd < 0)
1153 		(void)_close(newfd);
1154 	errno = oerrno;
1155 	return (ret);
1156 }
1157 
1158 /*
1159  * Check if the filesystem for "ent" has UFS-style links.
1160  */
1161 static int
1162 fts_ufslinks(FTS11 *sp, const FTSENT11 *ent)
1163 {
1164 	struct _fts_private11 *priv;
1165 	const char **cpp;
1166 
1167 	priv = (struct _fts_private11 *)sp;
1168 	/*
1169 	 * If this node's device is different from the previous, grab
1170 	 * the filesystem information, and decide on the reliability
1171 	 * of the link information from this filesystem for stat(2)
1172 	 * avoidance.
1173 	 */
1174 	if (priv->ftsp_dev != ent->fts_dev) {
1175 		if (freebsd11_statfs(ent->fts_path, &priv->ftsp_statfs) != -1) {
1176 			priv->ftsp_dev = ent->fts_dev;
1177 			priv->ftsp_linksreliable = 0;
1178 			for (cpp = ufslike_filesystems; *cpp; cpp++) {
1179 				if (strcmp(priv->ftsp_statfs.f_fstypename,
1180 				    *cpp) == 0) {
1181 					priv->ftsp_linksreliable = 1;
1182 					break;
1183 				}
1184 			}
1185 		} else {
1186 			priv->ftsp_linksreliable = 0;
1187 		}
1188 	}
1189 	return (priv->ftsp_linksreliable);
1190 }
1191 
1192 __sym_compat(fts_open, freebsd11_fts_open, FBSD_1.1);
1193 __sym_compat(fts_close, freebsd11_fts_close, FBSD_1.1);
1194 __sym_compat(fts_read, freebsd11_fts_read, FBSD_1.1);
1195 __sym_compat(fts_set, freebsd11_fts_set, FBSD_1.1);
1196 __sym_compat(fts_children, freebsd11_fts_children, FBSD_1.1);
1197 __sym_compat(fts_get_clientptr, freebsd11_fts_get_clientptr, FBSD_1.1);
1198 __sym_compat(fts_get_stream, freebsd11_fts_get_stream, FBSD_1.1);
1199 __sym_compat(fts_set_clientptr, freebsd11_fts_set_clientptr, FBSD_1.1);
1200