summaryrefslogblamecommitdiffstats
path: root/compat_fts.c
blob: 6756ad4947d6acada4fed22ff3c5f7166e8405ca (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406





















































































































































































































































































































































































































                                                                               
                                 



















































































                                                                             






                                                           
                                  
                                                                   
                                               
                                                             

























                                                                               
                                            






























































































































































                                                                               
                                       





                                         




                                                   




























































































































                                                                               
#include "config.h"

#ifdef HAVE_FTS

int dummy;

#else

/*	$OpenBSD: fts.c,v 1.46 2014/05/25 17:47:04 tedu Exp $	*/

/*-
 * Copyright (c) 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "compat_fts.h"

static FTSENT	*fts_alloc(FTS *, const char *, size_t);
static FTSENT	*fts_build(FTS *);
static void	 fts_lfree(FTSENT *);
static void	 fts_load(FTS *, FTSENT *);
static size_t	 fts_maxarglen(char * const *);
static void	 fts_padjust(FTS *, FTSENT *);
static int	 fts_palloc(FTS *, size_t);
static unsigned short	 fts_stat(FTS *, FTSENT *);
static int	 fts_safe_changedir(FTS *, FTSENT *, int, const char *);

#define	ISDOT(a)	(a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))

#define	CLR(opt)	(sp->fts_options &= ~(opt))
#define	ISSET(opt)	(sp->fts_options & (opt))
#define	SET(opt)	(sp->fts_options |= (opt))

#define	FCHDIR(sp, fd)	(!ISSET(FTS_NOCHDIR) && fchdir(fd))

FTS *
fts_open(char * const *argv, int options, void *dummy)
{
	FTS *sp;
	FTSENT *p, *root;
	int nitems;
	FTSENT *parent, *tmp;
	size_t len;

	/* Options check. */
	if (options & ~FTS_OPTIONMASK) {
		errno = EINVAL;
		return (NULL);
	}

	/* Allocate/initialize the stream */
	if ((sp = calloc(1, sizeof(FTS))) == NULL)
		return (NULL);
	sp->fts_options = options;

	/*
	 * Start out with 1K of path space, and enough, in any case,
	 * to hold the user's paths.
	 */
	if (fts_palloc(sp, MAX(fts_maxarglen(argv), PATH_MAX)))
		goto mem1;

	/* Allocate/initialize root's parent. */
	if ((parent = fts_alloc(sp, "", 0)) == NULL)
		goto mem2;
	parent->fts_level = FTS_ROOTPARENTLEVEL;

	/* Allocate/initialize root(s). */
	for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
		/* Don't allow zero-length paths. */
		if ((len = strlen(*argv)) == 0) {
			errno = ENOENT;
			goto mem3;
		}

		if ((p = fts_alloc(sp, *argv, len)) == NULL)
			goto mem3;
		p->fts_level = FTS_ROOTLEVEL;
		p->fts_parent = parent;
		p->fts_accpath = p->fts_name;
		p->fts_info = fts_stat(sp, p);

		/* Command-line "." and ".." are real directories. */
		if (p->fts_info == FTS_DOT)
			p->fts_info = FTS_D;

		p->fts_link = NULL;
		if (root == NULL)
			tmp = root = p;
		else {
			tmp->fts_link = p;
			tmp = p;
		}
	}

	/*
	 * Allocate a dummy pointer and make fts_read think that we've just
	 * finished the node before the root(s); set p->fts_info to FTS_INIT
	 * so that everything about the "current" node is ignored.
	 */
	if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
		goto mem3;
	sp->fts_cur->fts_link = root;
	sp->fts_cur->fts_info = FTS_INIT;

	/*
	 * If using chdir(2), grab a file descriptor pointing to dot to ensure
	 * that we can get back here; this could be avoided for some paths,
	 * but almost certainly not worth the effort.  Slashes, symbolic links,
	 * and ".." are all fairly nasty problems.  Note, if we can't get the
	 * descriptor we run anyway, just more slowly.
	 */
	if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0)
		SET(FTS_NOCHDIR);

	if (nitems == 0)
		free(parent);

	return (sp);

mem3:	fts_lfree(root);
	free(parent);
mem2:	free(sp->fts_path);
mem1:	free(sp);
	return (NULL);
}

static void
fts_load(FTS *sp, FTSENT *p)
{
	size_t len;
	char *cp;

	/*
	 * Load the stream structure for the next traversal.  Since we don't
	 * actually enter the directory until after the preorder visit, set
	 * the fts_accpath field specially so the chdir gets done to the right
	 * place and the user can access the first node.  From fts_open it's
	 * known that the path will fit.
	 */
	len = p->fts_pathlen = p->fts_namelen;
	memmove(sp->fts_path, p->fts_name, len + 1);
	if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
		len = strlen(++cp);
		memmove(p->fts_name, cp, len + 1);
		p->fts_namelen = len;
	}
	p->fts_accpath = p->fts_path = sp->fts_path;
	sp->fts_dev = p->fts_dev;
}

int
fts_close(FTS *sp)
{
	FTSENT *freep, *p;
	int rfd, error = 0;

	/*
	 * This still works if we haven't read anything -- the dummy structure
	 * points to the root list, so we step through to the end of the root
	 * list which has a valid parent pointer.
	 */
	if (sp->fts_cur) {
		for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
			freep = p;
			p = p->fts_link ? p->fts_link : p->fts_parent;
			free(freep);
		}
		free(p);
	}

	/* Stash the original directory fd if needed. */
	rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd;

	/* Free up child linked list, sort array, path buffer, stream ptr.*/
	if (sp->fts_child)
		fts_lfree(sp->fts_child);
	free(sp->fts_path);
	free(sp);

	/* Return to original directory, checking for error. */
	if (rfd != -1) {
		int saved_errno;
		error = fchdir(rfd);
		saved_errno = errno;
		(void)close(rfd);
		errno = saved_errno;
	}

	return (error);
}

/*
 * Special case of "/" at the end of the path so that slashes aren't
 * appended which would cause paths to be written as "....//foo".
 */
#define	NAPPEND(p)							\
	(p->fts_path[p->fts_pathlen - 1] == '/'				\
	    ? p->fts_pathlen - 1 : p->fts_pathlen)

FTSENT *
fts_read(FTS *sp)
{
	FTSENT *p, *tmp;
	int instr;
	char *t;

	/* If finished or unrecoverable error, return NULL. */
	if (sp->fts_cur == NULL || ISSET(FTS_STOP))
		return (NULL);

	/* Set current node pointer. */
	p = sp->fts_cur;

	/* Save and zero out user instructions. */
	instr = p->fts_instr;
	p->fts_instr = FTS_NOINSTR;

	/* Directory in pre-order. */
	if (p->fts_info == FTS_D) {
		/* If skipped or crossed mount point, do post-order visit. */
		if (instr == FTS_SKIP ||
		    (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
			if (sp->fts_child) {
				fts_lfree(sp->fts_child);
				sp->fts_child = NULL;
			}
			p->fts_info = FTS_DP;
			return (p);
		}

		/*
		 * Cd to the subdirectory.
		 *
		 * If have already read and now fail to chdir, whack the list
		 * to make the names come out right, and set the parent errno
		 * so the application will eventually get an error condition.
		 * Set the FTS_DONTCHDIR flag so that when we logically change
		 * directories back to the parent we don't do a chdir.
		 *
		 * If haven't read do so.  If the read fails, fts_build sets
		 * FTS_STOP or the fts_info field of the node.
		 */
		if (sp->fts_child) {
			if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
				p->fts_errno = errno;
				p->fts_flags |= FTS_DONTCHDIR;
				for (p = sp->fts_child; p; p = p->fts_link)
					p->fts_accpath =
					    p->fts_parent->fts_accpath;
			}
		} else if ((sp->fts_child = fts_build(sp)) == NULL) {
			if (ISSET(FTS_STOP))
				return (NULL);
			return (p);
		}
		p = sp->fts_child;
		sp->fts_child = NULL;
		goto name;
	}

	/* Move to the next node on this level. */
next:	tmp = p;
	if ((p = p->fts_link)) {
		free(tmp);

		/*
		 * If reached the top, return to the original directory (or
		 * the root of the tree), and load the paths for the next root.
		 */
		if (p->fts_level == FTS_ROOTLEVEL) {
			if (FCHDIR(sp, sp->fts_rfd)) {
				SET(FTS_STOP);
				return (NULL);
			}
			fts_load(sp, p);
			return (sp->fts_cur = p);
		}

		/*
		 * User may have called fts_set on the node.  If skipped,
		 * ignore.  If followed, get a file descriptor so we can
		 * get back if necessary.
		 */
		if (p->fts_instr == FTS_SKIP)
			goto next;

name:		t = sp->fts_path + NAPPEND(p->fts_parent);
		*t++ = '/';
		memmove(t, p->fts_name, p->fts_namelen + 1);
		return (sp->fts_cur = p);
	}

	/* Move up to the parent node. */
	p = tmp->fts_parent;
	free(tmp);

	if (p->fts_level == FTS_ROOTPARENTLEVEL) {
		/*
		 * Done; free everything up and set errno to 0 so the user
		 * can distinguish between error and EOF.
		 */
		free(p);
		errno = 0;
		return (sp->fts_cur = NULL);
	}

	/* NUL terminate the pathname. */
	sp->fts_path[p->fts_pathlen] = '\0';

	/*
	 * Return to the parent directory.  If at a root node or came through
	 * a symlink, go back through the file descriptor.  Otherwise, cd up
	 * one directory.
	 */
	if (p->fts_level == FTS_ROOTLEVEL) {
		if (FCHDIR(sp, sp->fts_rfd)) {
			SET(FTS_STOP);
			sp->fts_cur = p;
			return (NULL);
		}
	} else if (!(p->fts_flags & FTS_DONTCHDIR) &&
	    fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
		SET(FTS_STOP);
		sp->fts_cur = p;
		return (NULL);
	}
	p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
	return (sp->fts_cur = p);
}

/*
 * Fts_set takes the stream as an argument although it's not used in this
 * implementation; it would be necessary if anyone wanted to add global
 * semantics to fts using fts_set.  An error return is allowed for similar
 * reasons.
 */
/* ARGSUSED */
int
fts_set(FTS *sp, FTSENT *p, int instr)
{
	if (instr && instr != FTS_NOINSTR && instr != FTS_SKIP) {
		errno = EINVAL;
		return (1);
	}
	p->fts_instr = instr;
	return (0);
}

/*
 * This is the tricky part -- do not casually change *anything* in here.  The
 * idea is to build the linked list of entries that are used by fts_children
 * and fts_read.  There are lots of special cases.
 *
 * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
 * set and it's a physical walk (so that symbolic links can't be directories),
 * we can do things quickly.  First, if it's a 4.4BSD file system, the type
 * of the file is in the directory entry.  Otherwise, we assume that the number
 * of subdirectories in a node is equal to the number of links to the parent.
 * The former skips all stat calls.  The latter skips stat calls in any leaf
 * directories and for any files after the subdirectories in the directory have
 * been found, cutting the stat calls by about 2/3.
 */
static FTSENT *
fts_build(FTS *sp)
{
	struct dirent *dp;
	FTSENT *p, *head;
	FTSENT *cur, *tail;
	DIR *dirp;
	void *oldaddr;
	size_t dlen, len, maxlen;
	int nitems, cderrno, descend, level, nlinks, nostat, doadjust;
	int saved_errno;
	char *cp;

	/* Set current node pointer. */
	cur = sp->fts_cur;

	/*
	 * Open the directory for reading.  If this fails, we're done.
	 * If being called from fts_read, set the fts_info field.
	 */
	if ((dirp = opendir(cur->fts_accpath)) == NULL) {
		cur->fts_info = FTS_DNR;
		cur->fts_errno = errno;
		return (NULL);
	}

	/*
	 * Nlinks is the number of possible entries of type directory in the
	 * directory if we're cheating on stat calls, 0 if we're not doing
	 * any stat calls at all, -1 if we're doing stats on everything.
	 */
	nlinks = -1;
	nostat = 0;

	/*
	 * If we're going to need to stat anything or we want to descend
	 * and stay in the directory, chdir.  If this fails we keep going,
	 * but set a flag so we don't chdir after the post-order visit.
	 * We won't be able to stat anything, but we can still return the
	 * names themselves.  Note, that since fts_read won't be able to
	 * chdir into the directory, it will have to return different path
	 * names than before, i.e. "a/b" instead of "b".  Since the node
	 * has already been visited in pre-order, have to wait until the
	 * post-order visit to return the error.  There is a special case
	 * here, if there was nothing to stat then it's not an error to
	 * not be able to stat.  This is all fairly nasty.  If a program
	 * needed sorted entries or stat information, they had better be
	 * checking FTS_NS on the returned nodes.
	 */
	cderrno = 0;
	if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
		if (nlinks)
			cur->fts_errno = errno;
		cur->fts_flags |= FTS_DONTCHDIR;
		descend = 0;
		cderrno = errno;
		(void)closedir(dirp);
		dirp = NULL;
	} else
		descend = 1;

	/*
	 * Figure out the max file name length that can be stored in the
	 * current path -- the inner loop allocates more path as necessary.
	 * We really wouldn't have to do the maxlen calculations here, we
	 * could do them in fts_read before returning the path, but it's a
	 * lot easier here since the length is part of the dirent structure.
	 *
	 * If not changing directories set a pointer so that can just append
	 * each new name into the path.
	 */
	len = NAPPEND(cur);
	if (ISSET(FTS_NOCHDIR)) {
		cp = sp->fts_path + len;
		*cp++ = '/';
	}
	len++;
	maxlen = sp->fts_pathlen - len;

	/*
	 * fts_level is signed so we must prevent it from wrapping
	 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
	 */
	level = cur->fts_level;
	if (level < FTS_MAXLEVEL)
	    level++;

	/* Read the directory, attaching each entry to the `link' pointer. */
	doadjust = 0;
	for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
		if (ISDOT(dp->d_name))
			continue;

#ifdef HAVE_DIRENT_NAMLEN
		dlen = dp->d_namlen;
#else
		dlen = strlen(dp->d_name);
#endif

		if (!(p = fts_alloc(sp, dp->d_name, dlen)))
			goto mem1;
		if (dlen >= maxlen) {	/* include space for NUL */
			oldaddr = sp->fts_path;
			if (fts_palloc(sp, dlen + len + 1)) {
				/*
				 * No more memory for path or structures.  Save
				 * errno, free up the current structure and the
				 * structures already allocated.
				 */
mem1:				saved_errno = errno;
				if (p)
					free(p);
				fts_lfree(head);
				(void)closedir(dirp);
				cur->fts_info = FTS_ERR;
				SET(FTS_STOP);
				errno = saved_errno;
				return (NULL);
			}
			/* Did realloc() change the pointer? */
			if (oldaddr != sp->fts_path) {
				doadjust = 1;
				if (ISSET(FTS_NOCHDIR))
					cp = sp->fts_path + len;
			}
			maxlen = sp->fts_pathlen - len;
		}

		p->fts_level = level;
		p->fts_parent = sp->fts_cur;
		p->fts_pathlen = len + dlen;
		if (p->fts_pathlen < len) {
			/*
			 * If we wrap, free up the current structure and
			 * the structures already allocated, then error
			 * out with ENAMETOOLONG.
			 */
			free(p);
			fts_lfree(head);
			(void)closedir(dirp);
			cur->fts_info = FTS_ERR;
			SET(FTS_STOP);
			errno = ENAMETOOLONG;
			return (NULL);
		}

		if (cderrno) {
			if (nlinks) {
				p->fts_info = FTS_NS;
				p->fts_errno = cderrno;
			} else
				p->fts_info = FTS_NSOK;
			p->fts_accpath = cur->fts_accpath;
		} else if (nlinks == 0
#ifdef DT_DIR
		    || (nostat &&
		    dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
#endif
		    ) {
			p->fts_accpath =
			    ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
			p->fts_info = FTS_NSOK;
		} else {
			/* Build a file name for fts_stat to stat. */
			if (ISSET(FTS_NOCHDIR)) {
				p->fts_accpath = p->fts_path;
				memmove(cp, p->fts_name, p->fts_namelen + 1);
			} else
				p->fts_accpath = p->fts_name;
			/* Stat it. */
			p->fts_info = fts_stat(sp, p);

			/* Decrement link count if applicable. */
			if (nlinks > 0 && (p->fts_info == FTS_D ||
			    p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
				--nlinks;
		}

		/* We walk in directory order so "ls -f" doesn't get upset. */
		p->fts_link = NULL;
		if (head == NULL)
			head = tail = p;
		else {
			tail->fts_link = p;
			tail = p;
		}
		++nitems;
	}
	if (dirp)
		(void)closedir(dirp);

	/*
	 * If realloc() changed the address of the path, adjust the
	 * addresses for the rest of the tree and the dir list.
	 */
	if (doadjust)
		fts_padjust(sp, head);

	/*
	 * If not changing directories, reset the path back to original
	 * state.
	 */
	if (ISSET(FTS_NOCHDIR)) {
		if (len == sp->fts_pathlen || nitems == 0)
			--cp;
		*cp = '\0';
	}

	/*
	 * If descended after called from fts_children or after called from
	 * fts_read and nothing found, get back.  At the root level we use
	 * the saved fd; if one of fts_open()'s arguments is a relative path
	 * to an empty directory, we wind up here with no other way back.  If
	 * can't get back, we're done.
	 */
	if (descend && !nitems &&
	    (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) :
	    fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
		cur->fts_info = FTS_ERR;
		SET(FTS_STOP);
		return (NULL);
	}

	/* If didn't find anything, return NULL. */
	if (!nitems) {
		cur->fts_info = FTS_DP;
		return (NULL);
	}
	return (head);
}

static unsigned short
fts_stat(FTS *sp, FTSENT *p)
{
	FTSENT *t;
	dev_t dev;
	ino_t ino;
	struct stat *sbp;

	/* If user needs stat info, stat buffer already allocated. */
	sbp = p->fts_statp;

	if (lstat(p->fts_accpath, sbp)) {
		p->fts_errno = errno;
		memset(sbp, 0, sizeof(struct stat));
		return (FTS_NS);
	}

	if (S_ISDIR(sbp->st_mode)) {
		/*
		 * Set the device/inode.  Used to find cycles and check for
		 * crossing mount points.  Also remember the link count, used
		 * in fts_build to limit the number of stat calls.  It is
		 * understood that these fields are only referenced if fts_info
		 * is set to FTS_D.
		 */
		dev = p->fts_dev = sbp->st_dev;
		ino = p->fts_ino = sbp->st_ino;
		p->fts_nlink = sbp->st_nlink;

		if (ISDOT(p->fts_name))
			return (FTS_DOT);

		/*
		 * Cycle detection is done by brute force when the directory
		 * is first encountered.  If the tree gets deep enough or the
		 * number of symbolic links to directories is high enough,
		 * something faster might be worthwhile.
		 */
		for (t = p->fts_parent;
		    t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
			if (ino == t->fts_ino && dev == t->fts_dev) {
				p->fts_cycle = t;
				return (FTS_DC);
			}
		return (FTS_D);
	}
	if (S_ISLNK(sbp->st_mode))
		return (FTS_SL);
	if (S_ISREG(sbp->st_mode))
		return (FTS_F);
	return (FTS_DEFAULT);
}

static FTSENT *
fts_alloc(FTS *sp, const char *name, size_t namelen)
{
	FTSENT *p;
	size_t len;

	len = sizeof(FTSENT) + namelen;
	if ((p = calloc(1, len)) == NULL)
		return (NULL);

	p->fts_path = sp->fts_path;
	p->fts_namelen = namelen;
	p->fts_instr = FTS_NOINSTR;
	p->fts_statp = malloc(sizeof(struct stat));
	if (p->fts_statp == NULL) {
		free(p);
		return (NULL);
	}
	memcpy(p->fts_name, name, namelen);

	return (p);
}

static void
fts_lfree(FTSENT *head)
{
	FTSENT *p;

	/* Free a linked list of structures. */
	while ((p = head)) {
		head = head->fts_link;
		free(p);
	}
}

/*
 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
 * Most systems will allow creation of paths much longer than PATH_MAX, even
 * though the kernel won't resolve them.  Add the size (not just what's needed)
 * plus 256 bytes so don't realloc the path 2 bytes at a time.
 */
static int
fts_palloc(FTS *sp, size_t more)
{
	char *p;

	/*
	 * Check for possible wraparound.
	 */
	more += 256;
	if (sp->fts_pathlen + more < sp->fts_pathlen) {
		if (sp->fts_path)
			free(sp->fts_path);
		sp->fts_path = NULL;
		errno = ENAMETOOLONG;
		return (1);
	}
	sp->fts_pathlen += more;
	p = realloc(sp->fts_path, sp->fts_pathlen);
	if (p == NULL) {
		if (sp->fts_path)
			free(sp->fts_path);
		sp->fts_path = NULL;
		return (1);
	}
	sp->fts_path = p;
	return (0);
}

/*
 * When the path is realloc'd, have to fix all of the pointers in structures
 * already returned.
 */
static void
fts_padjust(FTS *sp, FTSENT *head)
{
	FTSENT *p;
	char *addr = sp->fts_path;

#define	ADJUST(p) {							\
	if ((p)->fts_accpath != (p)->fts_name) {			\
		(p)->fts_accpath =					\
		    (char *)addr + ((p)->fts_accpath - (p)->fts_path);	\
	}								\
	(p)->fts_path = addr;						\
}
	/* Adjust the current set of children. */
	for (p = sp->fts_child; p; p = p->fts_link)
		ADJUST(p);

	/* Adjust the rest of the tree, including the current level. */
	for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
		ADJUST(p);
		p = p->fts_link ? p->fts_link : p->fts_parent;
	}
}

static size_t
fts_maxarglen(char * const *argv)
{
	size_t len, max;

	for (max = 0; *argv; ++argv)
		if ((len = strlen(*argv)) > max)
			max = len;
	return (max + 1);
}

/*
 * Change to dir specified by fd or p->fts_accpath without getting
 * tricked by someone changing the world out from underneath us.
 * Assumes p->fts_dev and p->fts_ino are filled in.
 */
static int
fts_safe_changedir(FTS *sp, FTSENT *p, int fd, const char *path)
{
	int ret, oerrno, newfd;
	struct stat sb;

	newfd = fd;
	if (ISSET(FTS_NOCHDIR))
		return (0);
	if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0)
		return (-1);
	if (fstat(newfd, &sb)) {
		ret = -1;
		goto bail;
	}
	if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
		errno = ENOENT;		/* disinformation */
		ret = -1;
		goto bail;
	}
	ret = fchdir(newfd);
bail:
	oerrno = errno;
	if (fd < 0)
		(void)close(newfd);
	errno = oerrno;
	return (ret);
}

#endif