1/*-
2 * Copyright (c) 2003-2007 Tim Kientzle
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27/*-
28 * This is a new directory-walking system that addresses a number
29 * of problems I've had with fts(3).  In particular, it has no
30 * pathname-length limits (other than the size of 'int'), handles
31 * deep logical traversals, uses considerably less memory, and has
32 * an opaque interface (easier to modify in the future).
33 *
34 * Internally, it keeps a single list of "tree_entry" items that
35 * represent filesystem objects that require further attention.
36 * Non-directories are not kept in memory: they are pulled from
37 * readdir(), returned to the client, then freed as soon as possible.
38 * Any directory entry to be traversed gets pushed onto the stack.
39 *
40 * There is surprisingly little information that needs to be kept for
41 * each item on the stack.  Just the name, depth (represented here as the
42 * string length of the parent directory's pathname), and some markers
43 * indicating how to get back to the parent (via chdir("..") for a
44 * regular dir or via fchdir(2) for a symlink).
45 */
46#include "bsdtar_platform.h"
47__FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Exp $");
48
49#ifdef HAVE_SYS_STAT_H
50#include <sys/stat.h>
51#endif
52#ifdef HAVE_DIRECT_H
53#include <direct.h>
54#endif
55#ifdef HAVE_DIRENT_H
56#include <dirent.h>
57#endif
58#ifdef HAVE_ERRNO_H
59#include <errno.h>
60#endif
61#ifdef HAVE_FCNTL_H
62#include <fcntl.h>
63#endif
64#ifdef HAVE_STDLIB_H
65#include <stdlib.h>
66#endif
67#ifdef HAVE_STRING_H
68#include <string.h>
69#endif
70#ifdef HAVE_UNISTD_H
71#include <unistd.h>
72#endif
73#if defined(HAVE_WINDOWS_H) && !defined(__CYGWIN__)
74#include <windows.h>
75#endif
76
77#include "tree.h"
78
79/*
80 * TODO:
81 *    1) Loop checking.
82 *    3) Arbitrary logical traversals by closing/reopening intermediate fds.
83 */
84
85struct tree_entry {
86	int depth;
87	struct tree_entry *next;
88	struct tree_entry *parent;
89	char *name;
90	size_t dirname_length;
91	dev_t dev;
92	ino_t ino;
93	int flags;
94	/* How to return back to the parent of a symlink. */
95#ifdef HAVE_FCHDIR
96	int symlink_parent_fd;
97#elif defined(_WIN32) && !defined(__CYGWIN__)
98	char *symlink_parent_path;
99#else
100#error fchdir function required.
101#endif
102};
103
104/* Definitions for tree_entry.flags bitmap. */
105#define	isDir 1 /* This entry is a regular directory. */
106#define	isDirLink 2 /* This entry is a symbolic link to a directory. */
107#define needsFirstVisit 4 /* This is an initial entry. */
108#define	needsDescent 8 /* This entry needs to be previsited. */
109#define needsOpen 16 /* This is a directory that needs to be opened. */
110#define	needsAscent 32 /* This entry needs to be postvisited. */
111
112/*
113 * On Windows, "first visit" is handled as a pattern to be handed to
114 * _findfirst().  This is consistent with Windows conventions that
115 * file patterns are handled within the application.  On Posix,
116 * "first visit" is just returned to the client.
117 */
118
119/*
120 * Local data for this package.
121 */
122struct tree {
123	struct tree_entry	*stack;
124	struct tree_entry	*current;
125#if defined(HAVE_WINDOWS_H) && !defined(__CYGWIN__)
126	HANDLE d;
127	BY_HANDLE_FILE_INFORMATION fileInfo;
128#define INVALID_DIR_HANDLE INVALID_HANDLE_VALUE
129	WIN32_FIND_DATA _findData;
130	WIN32_FIND_DATA *findData;
131#else
132	DIR	*d;
133#define INVALID_DIR_HANDLE NULL
134	struct dirent *de;
135#endif
136	int	 flags;
137	int	 visit_type;
138	int	 tree_errno; /* Error code from last failed operation. */
139
140	/* Dynamically-sized buffer for holding path */
141	char	*buff;
142	size_t	 buff_length;
143
144	const char *basename; /* Last path element */
145	size_t	 dirname_length; /* Leading dir length */
146	size_t	 path_length; /* Total path length */
147
148	int	 depth;
149	int	 openCount;
150	int	 maxOpenCount;
151
152	struct stat	lst;
153	struct stat	st;
154};
155
156/* Definitions for tree.flags bitmap. */
157#define hasStat 16  /* The st entry is valid. */
158#define hasLstat 32 /* The lst entry is valid. */
159#define	hasFileInfo 64 /* The Windows fileInfo entry is valid. */
160
161#if defined(_WIN32) && !defined(__CYGWIN__)
162static int
163tree_dir_next_windows(struct tree *t, const char *pattern);
164#else
165static int
166tree_dir_next_posix(struct tree *t);
167#endif
168
169#ifdef HAVE_DIRENT_D_NAMLEN
170/* BSD extension; avoids need for a strlen() call. */
171#define D_NAMELEN(dp)	(dp)->d_namlen
172#else
173#define D_NAMELEN(dp)	(strlen((dp)->d_name))
174#endif
175
176#include <stdio.h>
177void
178tree_dump(struct tree *t, FILE *out)
179{
180	char buff[300];
181	struct tree_entry *te;
182
183	fprintf(out, "\tdepth: %d\n", t->depth);
184	fprintf(out, "\tbuff: %s\n", t->buff);
185	fprintf(out, "\tpwd: %s\n", getcwd(buff, sizeof(buff)));
186	fprintf(out, "\tbasename: %s\n", t->basename);
187	fprintf(out, "\tstack:\n");
188	for (te = t->stack; te != NULL; te = te->next) {
189		fprintf(out, "\t\t%s%d:\"%s\" %s%s%s%s%s%s\n",
190		    t->current == te ? "*" : " ",
191		    te->depth,
192		    te->name,
193		    te->flags & needsFirstVisit ? "V" : "",
194		    te->flags & needsDescent ? "D" : "",
195		    te->flags & needsOpen ? "O" : "",
196		    te->flags & needsAscent ? "A" : "",
197		    te->flags & isDirLink ? "L" : "",
198		    (t->current == te && t->d) ? "+" : ""
199		);
200	}
201}
202
203/*
204 * Add a directory path to the current stack.
205 */
206static void
207tree_push(struct tree *t, const char *path)
208{
209	struct tree_entry *te;
210
211	te = malloc(sizeof(*te));
212	memset(te, 0, sizeof(*te));
213	te->next = t->stack;
214	te->parent = t->current;
215	if (te->parent)
216		te->depth = te->parent->depth + 1;
217	t->stack = te;
218#ifdef HAVE_FCHDIR
219	te->symlink_parent_fd = -1;
220	te->name = strdup(path);
221#elif defined(_WIN32) && !defined(__CYGWIN__)
222	te->symlink_parent_path = NULL;
223	te->name = strdup(path);
224#endif
225	te->flags = needsDescent | needsOpen | needsAscent;
226	te->dirname_length = t->dirname_length;
227}
228
229/*
230 * Append a name to the current dir path.
231 */
232static void
233tree_append(struct tree *t, const char *name, size_t name_length)
234{
235	char *p;
236	size_t size_needed;
237
238	if (t->buff != NULL)
239		t->buff[t->dirname_length] = '\0';
240	/* Strip trailing '/' from name, unless entire name is "/". */
241	while (name_length > 1 && name[name_length - 1] == '/')
242		name_length--;
243
244	/* Resize pathname buffer as needed. */
245	size_needed = name_length + 1 + t->dirname_length;
246	if (t->buff_length < size_needed) {
247		if (t->buff_length < 1024)
248			t->buff_length = 1024;
249		while (t->buff_length < size_needed)
250			t->buff_length *= 2;
251		t->buff = realloc(t->buff, t->buff_length);
252	}
253	if (t->buff == NULL)
254		abort();
255	p = t->buff + t->dirname_length;
256	t->path_length = t->dirname_length + name_length;
257	/* Add a separating '/' if it's needed. */
258	if (t->dirname_length > 0 && p[-1] != '/') {
259		*p++ = '/';
260		t->path_length ++;
261	}
262#if HAVE_STRNCPY_S
263	strncpy_s(p, t->buff_length - (p - t->buff), name, name_length);
264#else
265	strncpy(p, name, name_length);
266#endif
267	p[name_length] = '\0';
268	t->basename = p;
269}
270
271/*
272 * Open a directory tree for traversal.
273 */
274struct tree *
275tree_open(const char *path)
276{
277#ifdef HAVE_FCHDIR
278	struct tree *t;
279
280	t = malloc(sizeof(*t));
281	memset(t, 0, sizeof(*t));
282	/* First item is set up a lot like a symlink traversal. */
283	tree_push(t, path);
284	t->stack->flags = needsFirstVisit | isDirLink | needsAscent;
285	t->stack->symlink_parent_fd = open(".", O_RDONLY);
286	t->openCount++;
287	t->d = INVALID_DIR_HANDLE;
288	return (t);
289#elif defined(_WIN32) && !defined(__CYGWIN__)
290	struct tree *t;
291	char *cwd = _getcwd(NULL, 0);
292	char *pathname = strdup(path), *p, *base;
293
294	if (pathname == NULL)
295		abort();
296	for (p = pathname; *p != '\0'; ++p) {
297		if (*p == '\\')
298			*p = '/';
299	}
300	base = pathname;
301
302	t = malloc(sizeof(*t));
303	memset(t, 0, sizeof(*t));
304	/* First item is set up a lot like a symlink traversal. */
305	/* printf("Looking for wildcard in %s\n", path); */
306	/* TODO: wildcard detection here screws up on \\?\c:\ UNC names */
307	if (strchr(base, '*') || strchr(base, '?')) {
308		// It has a wildcard in it...
309		// Separate the last element.
310		p = strrchr(base, '/');
311		if (p != NULL) {
312			*p = '\0';
313			chdir(base);
314			tree_append(t, base, p - base);
315			t->dirname_length = t->path_length;
316			base = p + 1;
317		}
318	}
319	tree_push(t, base);
320	free(pathname);
321	t->stack->flags = needsFirstVisit | isDirLink | needsAscent;
322	t->stack->symlink_parent_path = cwd;
323	t->d = INVALID_DIR_HANDLE;
324	return (t);
325#endif
326}
327
328/*
329 * We've finished a directory; ascend back to the parent.
330 */
331static int
332tree_ascend(struct tree *t)
333{
334	struct tree_entry *te;
335	int r = 0;
336
337	te = t->stack;
338	t->depth--;
339	if (te->flags & isDirLink) {
340#ifdef HAVE_FCHDIR
341		if (fchdir(te->symlink_parent_fd) != 0) {
342			t->tree_errno = errno;
343			r = TREE_ERROR_FATAL;
344		}
345		close(te->symlink_parent_fd);
346#elif defined(_WIN32) && !defined(__CYGWIN__)
347		if (SetCurrentDirectory(te->symlink_parent_path) == 0) {
348			t->tree_errno = errno;
349			r = TREE_ERROR_FATAL;
350		}
351		free(te->symlink_parent_path);
352		te->symlink_parent_path = NULL;
353#endif
354		t->openCount--;
355	} else {
356#if defined(_WIN32) && !defined(__CYGWIN__)
357		if (SetCurrentDirectory("..") == 0) {
358#else
359		if (chdir("..") != 0) {
360#endif
361			t->tree_errno = errno;
362			r = TREE_ERROR_FATAL;
363		}
364	}
365	return (r);
366}
367
368/*
369 * Pop the working stack.
370 */
371static void
372tree_pop(struct tree *t)
373{
374	struct tree_entry *te;
375
376	if (t->buff)
377		t->buff[t->dirname_length] = '\0';
378	if (t->stack == t->current && t->current != NULL)
379		t->current = t->current->parent;
380	te = t->stack;
381	t->stack = te->next;
382	t->dirname_length = te->dirname_length;
383	if (t->buff) {
384		t->basename = t->buff + t->dirname_length;
385		while (t->basename[0] == '/')
386			t->basename++;
387	}
388	free(te->name);
389	free(te);
390}
391
392/*
393 * Get the next item in the tree traversal.
394 */
395int
396tree_next(struct tree *t)
397{
398	int r;
399
400	/* If we're called again after a fatal error, that's an API
401	 * violation.  Just crash now. */
402	if (t->visit_type == TREE_ERROR_FATAL) {
403		fprintf(stderr, "Unable to continue traversing"
404		    " directory heirarchy after a fatal error.");
405		abort();
406	}
407
408	while (t->stack != NULL) {
409		/* If there's an open dir, get the next entry from there. */
410		if (t->d != INVALID_DIR_HANDLE) {
411#if defined(_WIN32) && !defined(__CYGWIN__)
412			r = tree_dir_next_windows(t, NULL);
413#else
414			r = tree_dir_next_posix(t);
415#endif
416			if (r == 0)
417				continue;
418			return (r);
419		}
420
421		if (t->stack->flags & needsFirstVisit) {
422#if defined(_WIN32) && !defined(__CYGWIN__)
423			char *d = t->stack->name;
424			t->stack->flags &= ~needsFirstVisit;
425			if (strchr(d, '*') || strchr(d, '?')) {
426				r = tree_dir_next_windows(t, d);
427				if (r == 0)
428					continue;
429				return (r);
430			}
431			// Not a pattern, handle it as-is...
432#endif
433			/* Top stack item needs a regular visit. */
434			t->current = t->stack;
435			tree_append(t, t->stack->name, strlen(t->stack->name));
436			//t->dirname_length = t->path_length;
437			//tree_pop(t);
438			t->stack->flags &= ~needsFirstVisit;
439			return (t->visit_type = TREE_REGULAR);
440		} else if (t->stack->flags & needsDescent) {
441			/* Top stack item is dir to descend into. */
442			t->current = t->stack;
443			tree_append(t, t->stack->name, strlen(t->stack->name));
444			t->stack->flags &= ~needsDescent;
445			/* If it is a link, set up fd for the ascent. */
446			if (t->stack->flags & isDirLink) {
447#ifdef HAVE_FCHDIR
448				t->stack->symlink_parent_fd = open(".", O_RDONLY);
449				t->openCount++;
450				if (t->openCount > t->maxOpenCount)
451					t->maxOpenCount = t->openCount;
452#elif defined(_WIN32) && !defined(__CYGWIN__)
453				t->stack->symlink_parent_path = _getcwd(NULL, 0);
454#endif
455			}
456			t->dirname_length = t->path_length;
457#if defined(_WIN32) && !defined(__CYGWIN__)
458			if (t->path_length == 259 || !SetCurrentDirectory(t->stack->name) != 0)
459#else
460			if (chdir(t->stack->name) != 0)
461#endif
462			{
463				/* chdir() failed; return error */
464				tree_pop(t);
465				t->tree_errno = errno;
466				return (t->visit_type = TREE_ERROR_DIR);
467			}
468			t->depth++;
469			return (t->visit_type = TREE_POSTDESCENT);
470		} else if (t->stack->flags & needsOpen) {
471			t->stack->flags &= ~needsOpen;
472#if defined(_WIN32) && !defined(__CYGWIN__)
473			r = tree_dir_next_windows(t, "*");
474#else
475			r = tree_dir_next_posix(t);
476#endif
477			if (r == 0)
478				continue;
479			return (r);
480		} else if (t->stack->flags & needsAscent) {
481		        /* Top stack item is dir and we're done with it. */
482			r = tree_ascend(t);
483			tree_pop(t);
484			t->visit_type = r != 0 ? r : TREE_POSTASCENT;
485			return (t->visit_type);
486		} else {
487			/* Top item on stack is dead. */
488			tree_pop(t);
489			t->flags &= ~hasLstat;
490			t->flags &= ~hasStat;
491		}
492	}
493	return (t->visit_type = 0);
494}
495
496#if defined(_WIN32) && !defined(__CYGWIN__)
497static int
498tree_dir_next_windows(struct tree *t, const char *pattern)
499{
500	const char *name;
501	size_t namelen;
502	int r;
503
504	for (;;) {
505		if (pattern != NULL) {
506			t->d = FindFirstFile(pattern, &t->_findData);
507			if (t->d == INVALID_DIR_HANDLE) {
508				r = tree_ascend(t); /* Undo "chdir" */
509				tree_pop(t);
510				t->tree_errno = errno;
511				t->visit_type = r != 0 ? r : TREE_ERROR_DIR;
512				return (t->visit_type);
513			}
514			t->findData = &t->_findData;
515			pattern = NULL;
516		} else if (!FindNextFile(t->d, &t->_findData)) {
517			FindClose(t->d);
518			t->d = INVALID_DIR_HANDLE;
519			t->findData = NULL;
520			return (0);
521		}
522		name = t->findData->cFileName;
523		namelen = strlen(name);
524		t->flags &= ~hasLstat;
525		t->flags &= ~hasStat;
526		if (name[0] == '.' && name[1] == '\0')
527			continue;
528		if (name[0] == '.' && name[1] == '.' && name[2] == '\0')
529			continue;
530		tree_append(t, name, namelen);
531		return (t->visit_type = TREE_REGULAR);
532	}
533}
534#else
535static int
536tree_dir_next_posix(struct tree *t)
537{
538	int r;
539	const char *name;
540	size_t namelen;
541
542	if (t->d == NULL) {
543		if ((t->d = opendir(".")) == NULL) {
544			r = tree_ascend(t); /* Undo "chdir" */
545			tree_pop(t);
546			t->tree_errno = errno;
547			t->visit_type = r != 0 ? r : TREE_ERROR_DIR;
548			return (t->visit_type);
549		}
550	}
551	for (;;) {
552		t->de = readdir(t->d);
553		if (t->de == NULL) {
554			closedir(t->d);
555			t->d = INVALID_DIR_HANDLE;
556			return (0);
557		}
558		name = t->de->d_name;
559		namelen = D_NAMELEN(t->de);
560		t->flags &= ~hasLstat;
561		t->flags &= ~hasStat;
562		if (name[0] == '.' && name[1] == '\0')
563			continue;
564		if (name[0] == '.' && name[1] == '.' && name[2] == '\0')
565			continue;
566		tree_append(t, name, namelen);
567		return (t->visit_type = TREE_REGULAR);
568	}
569}
570#endif
571
572/*
573 * Return error code.
574 */
575int
576tree_errno(struct tree *t)
577{
578	return (t->tree_errno);
579}
580
581/*
582 * Called by the client to mark the directory just returned from
583 * tree_next() as needing to be visited.
584 */
585void
586tree_descend(struct tree *t)
587{
588	if (t->visit_type != TREE_REGULAR)
589		return;
590
591	if (tree_current_is_physical_dir(t)) {
592		tree_push(t, t->basename);
593		t->stack->flags |= isDir;
594	} else if (tree_current_is_dir(t)) {
595		tree_push(t, t->basename);
596		t->stack->flags |= isDirLink;
597	}
598}
599
600/*
601 * Get the stat() data for the entry just returned from tree_next().
602 */
603const struct stat *
604tree_current_stat(struct tree *t)
605{
606	if (!(t->flags & hasStat)) {
607		if (stat(tree_current_access_path(t), &t->st) != 0)
608			return NULL;
609		t->flags |= hasStat;
610	}
611	return (&t->st);
612}
613
614#if defined(HAVE_WINDOWS_H) && !defined(__CYGWIN__)
615const BY_HANDLE_FILE_INFORMATION *
616tree_current_file_information(struct tree *t)
617{
618	if (!(t->flags & hasFileInfo)) {
619		HANDLE h = CreateFile(tree_current_access_path(t),
620			0, 0, NULL,
621			OPEN_EXISTING,
622			FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT,
623			NULL);
624		if (h == INVALID_HANDLE_VALUE)
625			return NULL;
626		if (!GetFileInformationByHandle(h, &t->fileInfo)) {
627			CloseHandle(h);
628			return NULL;
629		}
630		CloseHandle(h);
631		t->flags |= hasFileInfo;
632	}
633	return (&t->fileInfo);
634}
635#endif
636/*
637 * Get the lstat() data for the entry just returned from tree_next().
638 */
639const struct stat *
640tree_current_lstat(struct tree *t)
641{
642#if defined(_WIN32) && !defined(__CYGWIN__)
643	return (tree_current_stat(t));
644#else
645	if (!(t->flags & hasLstat)) {
646		if (lstat(tree_current_access_path(t), &t->lst) != 0)
647			return NULL;
648		t->flags |= hasLstat;
649	}
650	return (&t->lst);
651#endif
652}
653
654/*
655 * Test whether current entry is a dir or link to a dir.
656 */
657int
658tree_current_is_dir(struct tree *t)
659{
660#if defined(_WIN32) && !defined(__CYGWIN__)
661	if (t->findData)
662		return (t->findData->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
663	if (tree_current_file_information(t))
664		return (t->fileInfo.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
665	return (0);
666#else
667	const struct stat *st;
668	/*
669	 * If we already have lstat() info, then try some
670	 * cheap tests to determine if this is a dir.
671	 */
672	if (t->flags & hasLstat) {
673		/* If lstat() says it's a dir, it must be a dir. */
674		if (S_ISDIR(tree_current_lstat(t)->st_mode))
675			return 1;
676		/* Not a dir; might be a link to a dir. */
677		/* If it's not a link, then it's not a link to a dir. */
678		if (!S_ISLNK(tree_current_lstat(t)->st_mode))
679			return 0;
680		/*
681		 * It's a link, but we don't know what it's a link to,
682		 * so we'll have to use stat().
683		 */
684	}
685
686	st = tree_current_stat(t);
687	/* If we can't stat it, it's not a dir. */
688	if (st == NULL)
689		return 0;
690	/* Use the definitive test.  Hopefully this is cached. */
691	return (S_ISDIR(st->st_mode));
692#endif
693}
694
695/*
696 * Test whether current entry is a physical directory.  Usually, we
697 * already have at least one of stat() or lstat() in memory, so we
698 * use tricks to try to avoid an extra trip to the disk.
699 */
700int
701tree_current_is_physical_dir(struct tree *t)
702{
703#if defined(_WIN32) && !defined(__CYGWIN__)
704	if (tree_current_is_physical_link(t))
705		return (0);
706	return (tree_current_is_dir(t));
707#else
708	const struct stat *st;
709
710	/*
711	 * If stat() says it isn't a dir, then it's not a dir.
712	 * If stat() data is cached, this check is free, so do it first.
713	 */
714	if ((t->flags & hasStat)
715	    && (!S_ISDIR(tree_current_stat(t)->st_mode)))
716		return 0;
717
718	/*
719	 * Either stat() said it was a dir (in which case, we have
720	 * to determine whether it's really a link to a dir) or
721	 * stat() info wasn't available.  So we use lstat(), which
722	 * hopefully is already cached.
723	 */
724
725	st = tree_current_lstat(t);
726	/* If we can't stat it, it's not a dir. */
727	if (st == NULL)
728		return 0;
729	/* Use the definitive test.  Hopefully this is cached. */
730	return (S_ISDIR(st->st_mode));
731#endif
732}
733
734/*
735 * Test whether current entry is a symbolic link.
736 */
737int
738tree_current_is_physical_link(struct tree *t)
739{
740#if defined(_WIN32) && !defined(__CYGWIN__)
741#ifndef IO_REPARSE_TAG_SYMLINK
742/* Old SDKs do not provide IO_REPARSE_TAG_SYMLINK */
743#define IO_REPARSE_TAG_SYMLINK 0xA000000CL
744#endif
745	if (t->findData)
746		return ((t->findData->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
747				&& (t->findData->dwReserved0 == IO_REPARSE_TAG_SYMLINK));
748	return (0);
749#else
750	const struct stat *st = tree_current_lstat(t);
751	if (st == NULL)
752		return 0;
753	return (S_ISLNK(st->st_mode));
754#endif
755}
756
757/*
758 * Return the access path for the entry just returned from tree_next().
759 */
760const char *
761tree_current_access_path(struct tree *t)
762{
763	return (t->basename);
764}
765
766/*
767 * Return the full path for the entry just returned from tree_next().
768 */
769const char *
770tree_current_path(struct tree *t)
771{
772	return (t->buff);
773}
774
775/*
776 * Return the length of the path for the entry just returned from tree_next().
777 */
778size_t
779tree_current_pathlen(struct tree *t)
780{
781	return (t->path_length);
782}
783
784/*
785 * Return the nesting depth of the entry just returned from tree_next().
786 */
787int
788tree_current_depth(struct tree *t)
789{
790	return (t->depth);
791}
792
793/*
794 * Terminate the traversal and release any resources.
795 */
796void
797tree_close(struct tree *t)
798{
799	/* Release anything remaining in the stack. */
800	while (t->stack != NULL)
801		tree_pop(t);
802	free(t->buff);
803	/* TODO: Ensure that premature close() resets cwd */
804#if 0
805#ifdef HAVE_FCHDIR
806	if (t->initialDirFd >= 0) {
807		int s = fchdir(t->initialDirFd);
808		(void)s; /* UNUSED */
809		close(t->initialDirFd);
810		t->initialDirFd = -1;
811	}
812#elif defined(_WIN32) && !defined(__CYGWIN__)
813	if (t->initialDir != NULL) {
814		SetCurrentDir(t->initialDir);
815		free(t->initialDir);
816		t->initialDir = NULL;
817	}
818#endif
819#endif
820	free(t);
821}
822