1 /* $Id: fts_compat.c 16 2009-06-19 09:26:19Z haag $ */
2 /* TNFTPD ORIGINAL: libnetbsd/fts_open.c */
3
4 /* $TNFTPPD: fts_open.c,v 1.4 2003/12/17 01:42:45 lukem Exp $ */
5 /* from NetBSD: __fts13.c,v 1.36 2001/11/28 22:31:39 christos Exp */
6
7 /*-
8 * Copyright (c) 1990, 1993, 1994
9 * The Regents of the University of California. All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include "config.h"
37
38 #include <sys/param.h>
39 #include <sys/stat.h>
40 #include <sys/types.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46
47 #ifdef HAVE_ISO_LIMITS_ISO_H
48 #include <iso/limits_iso.h>
49 #endif
50
51 #if HAVE_DIRENT_H
52 # include <dirent.h>
53 # define NAMLEN(dirent) strlen((dirent)->d_name)
54 #else
55 # define dirent direct
56 # define NAMLEN(dirent) (dirent)->d_namlen
57 # if HAVE_SYS_NDIR_H
58 # include <sys/ndir.h>
59 # endif
60 # if HAVE_SYS_DIR_H
61 # include <sys/dir.h>
62 # endif
63 # if HAVE_NDIR_H
64 # include <ndir.h>
65 # endif
66 #endif
67
68 #include "fts_compat.h"
69
70 #if ! defined(MIN)
71 # define MIN(a, b) ((a) < (b) ? (a) : (b))
72 #endif
73 #if ! defined(MAX)
74 # define MAX(a, b) ((a) < (b) ? (b) : (a))
75 #endif
76
77 #define STAT stat
78
79 static FTSENT *fts_alloc(FTS *, const char *, size_t);
80 static FTSENT *fts_build(FTS *, int);
81 static void fts_lfree(FTSENT *);
82 static void fts_load(FTS *, FTSENT *);
83 static size_t fts_maxarglen(char * const *);
84 static size_t fts_pow2(size_t);
85 static int fts_palloc(FTS *, size_t);
86 static void fts_padjust(FTS *, FTSENT *);
87 static FTSENT *fts_sort(FTS *, FTSENT *, size_t);
88 static u_short fts_stat(FTS *, FTSENT *, int);
89 static int fts_safe_changedir(const FTS *, const FTSENT *, int,
90 const char *);
91
92 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
93
94 #define CLR(opt) (sp->fts_options &= ~(opt))
95 #define ISSET(opt) (sp->fts_options & (opt))
96 #define SET(opt) (sp->fts_options |= (opt))
97
98 #define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path))
99 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd))
100
101 /* fts_build flags */
102 #define BCHILD 1 /* fts_children */
103 #define BNAMES 2 /* fts_children, names only */
104 #define BREAD 3 /* fts_read */
105
106 #ifndef DTF_HIDEW
107 #undef FTS_WHITEOUT
108 #endif
109
110 FTS *
fts_open_compat(char * const * argv,int options,int (* compar)(const FTSENT **,const FTSENT **))111 fts_open_compat(char * const *argv, int options,
112 int (*compar)(const FTSENT **, const FTSENT **))
113 {
114 FTS *sp;
115 FTSENT *p, *root;
116 size_t nitems;
117 FTSENT *parent, *tmp = NULL; /* pacify gcc */
118 size_t len;
119
120 /* Options check. */
121 if (options & ~FTS_OPTIONMASK) {
122 errno = EINVAL;
123 return (NULL);
124 }
125
126 /* Allocate/initialize the stream */
127 if ((sp = malloc((u_int)sizeof(FTS))) == NULL)
128 return (NULL);
129 memset(sp, 0, sizeof(FTS));
130 sp->fts_compar = compar;
131 sp->fts_options = options;
132
133 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
134 if (ISSET(FTS_LOGICAL))
135 SET(FTS_NOCHDIR);
136
137 /*
138 * Start out with 1K of path space, and enough, in any case,
139 * to hold the user's paths.
140 */
141 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
142 goto mem1;
143
144 /* Allocate/initialize root's parent. */
145 if ((parent = fts_alloc(sp, "", 0)) == NULL)
146 goto mem2;
147 parent->fts_level = FTS_ROOTPARENTLEVEL;
148
149 /* Allocate/initialize root(s). */
150 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
151 /* Don't allow zero-length paths. */
152 if ((len = strlen(*argv)) == 0) {
153 errno = ENOENT;
154 goto mem3;
155 }
156
157 if ((p = fts_alloc(sp, *argv, len)) == NULL)
158 goto mem3;
159 p->fts_level = FTS_ROOTLEVEL;
160 p->fts_parent = parent;
161 p->fts_accpath = p->fts_name;
162 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW));
163
164 /* Command-line "." and ".." are real directories. */
165 if (p->fts_info == FTS_DOT)
166 p->fts_info = FTS_D;
167
168 /*
169 * If comparison routine supplied, traverse in sorted
170 * order; otherwise traverse in the order specified.
171 */
172 if (compar) {
173 p->fts_link = root;
174 root = p;
175 } else {
176 p->fts_link = NULL;
177 if (root == NULL)
178 tmp = root = p;
179 else {
180 tmp->fts_link = p;
181 tmp = p;
182 }
183 }
184 }
185 if (compar && nitems > 1)
186 root = fts_sort(sp, root, nitems);
187
188 /*
189 * Allocate a dummy pointer and make fts_read think that we've just
190 * finished the node before the root(s); set p->fts_info to FTS_INIT
191 * so that everything about the "current" node is ignored.
192 */
193 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
194 goto mem3;
195 sp->fts_cur->fts_link = root;
196 sp->fts_cur->fts_info = FTS_INIT;
197
198 /*
199 * If using chdir(2), grab a file descriptor pointing to dot to insure
200 * that we can get back here; this could be avoided for some paths,
201 * but almost certainly not worth the effort. Slashes, symbolic links,
202 * and ".." are all fairly nasty problems. Note, if we can't get the
203 * descriptor we run anyway, just more slowly.
204 */
205 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0)
206 SET(FTS_NOCHDIR);
207
208 return (sp);
209
210 mem3: fts_lfree(root);
211 free(parent);
212 mem2: free(sp->fts_path);
213 mem1: free(sp);
214 return (NULL);
215 }
216
217 static void
fts_load(FTS * sp,FTSENT * p)218 fts_load(FTS *sp, FTSENT *p)
219 {
220 size_t len;
221 char *cp;
222
223 /*
224 * Load the stream structure for the next traversal. Since we don't
225 * actually enter the directory until after the preorder visit, set
226 * the fts_accpath field specially so the chdir gets done to the right
227 * place and the user can access the first node. From fts_open it's
228 * known that the path will fit.
229 */
230 len = p->fts_pathlen = p->fts_namelen;
231 memmove(sp->fts_path, p->fts_name, len + 1);
232 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
233 len = strlen(++cp);
234 memmove(p->fts_name, cp, len + 1);
235 p->fts_namelen = len;
236 }
237 p->fts_accpath = p->fts_path = sp->fts_path;
238 sp->fts_dev = p->fts_dev;
239 }
240
241 int
fts_close_compat(FTS * sp)242 fts_close_compat(FTS *sp)
243 {
244 FTSENT *freep, *p;
245 int saved_errno = 0;
246
247 /*
248 * This still works if we haven't read anything -- the dummy structure
249 * points to the root list, so we step through to the end of the root
250 * list which has a valid parent pointer.
251 */
252 if (sp->fts_cur) {
253 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
254 freep = p;
255 p = p->fts_link ? p->fts_link : p->fts_parent;
256 free(freep);
257 }
258 free(p);
259 }
260
261 /* Free up child linked list, sort array, path buffer. */
262 if (sp->fts_child)
263 fts_lfree(sp->fts_child);
264 if (sp->fts_array)
265 free(sp->fts_array);
266 free(sp->fts_path);
267
268 /* Return to original directory, save errno if necessary. */
269 if (!ISSET(FTS_NOCHDIR)) {
270 if (fchdir(sp->fts_rfd))
271 saved_errno = errno;
272 (void)close(sp->fts_rfd);
273 }
274
275 /* Free up the stream pointer. */
276 free(sp);
277 /* ISSET() is illegal after this, since the macro touches sp */
278
279 /* Set errno and return. */
280 if (saved_errno) {
281 errno = saved_errno;
282 return (-1);
283 }
284 return (0);
285 }
286
287 /*
288 * Special case a root of "/" so that slashes aren't appended which would
289 * cause paths to be written as "//foo".
290 */
291 #define NAPPEND(p) \
292 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \
293 p->fts_path[0] == '/' ? 0 : p->fts_pathlen)
294
295 FTSENT *
fts_read_compat(FTS * sp)296 fts_read_compat(FTS *sp)
297 {
298 FTSENT *p, *tmp;
299 int instr;
300 char *t;
301 int saved_errno;
302
303 /* If finished or unrecoverable error, return NULL. */
304 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
305 return (NULL);
306
307 /* Set current node pointer. */
308 p = sp->fts_cur;
309
310 /* Save and zero out user instructions. */
311 instr = p->fts_instr;
312 p->fts_instr = FTS_NOINSTR;
313
314 /* Any type of file may be re-visited; re-stat and re-turn. */
315 if (instr == FTS_AGAIN) {
316 p->fts_info = fts_stat(sp, p, 0);
317 return (p);
318 }
319
320 /*
321 * Following a symlink -- SLNONE test allows application to see
322 * SLNONE and recover. If indirecting through a symlink, have
323 * keep a pointer to current location. If unable to get that
324 * pointer, follow fails.
325 */
326 if (instr == FTS_FOLLOW &&
327 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
328 p->fts_info = fts_stat(sp, p, 1);
329 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
330 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) {
331 p->fts_errno = errno;
332 p->fts_info = FTS_ERR;
333 } else
334 p->fts_flags |= FTS_SYMFOLLOW;
335 }
336 return (p);
337 }
338
339 /* Directory in pre-order. */
340 if (p->fts_info == FTS_D) {
341 /* If skipped or crossed mount point, do post-order visit. */
342 if (instr == FTS_SKIP ||
343 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
344 if (p->fts_flags & FTS_SYMFOLLOW)
345 (void)close(p->fts_symfd);
346 if (sp->fts_child) {
347 fts_lfree(sp->fts_child);
348 sp->fts_child = NULL;
349 }
350 p->fts_info = FTS_DP;
351 return (p);
352 }
353
354 /* Rebuild if only read the names and now traversing. */
355 if (sp->fts_child && ISSET(FTS_NAMEONLY)) {
356 CLR(FTS_NAMEONLY);
357 fts_lfree(sp->fts_child);
358 sp->fts_child = NULL;
359 }
360
361 /*
362 * Cd to the subdirectory.
363 *
364 * If have already read and now fail to chdir, whack the list
365 * to make the names come out right, and set the parent errno
366 * so the application will eventually get an error condition.
367 * Set the FTS_DONTCHDIR flag so that when we logically change
368 * directories back to the parent we don't do a chdir.
369 *
370 * If haven't read do so. If the read fails, fts_build sets
371 * FTS_STOP or the fts_info field of the node.
372 */
373 if (sp->fts_child) {
374 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
375 p->fts_errno = errno;
376 p->fts_flags |= FTS_DONTCHDIR;
377 for (p = sp->fts_child; p; p = p->fts_link)
378 p->fts_accpath =
379 p->fts_parent->fts_accpath;
380 }
381 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
382 if (ISSET(FTS_STOP))
383 return (NULL);
384 return (p);
385 }
386 p = sp->fts_child;
387 sp->fts_child = NULL;
388 goto name;
389 }
390
391 /* Move to the next node on this level. */
392 next: tmp = p;
393 if ((p = p->fts_link) != NULL) {
394
395 free(tmp);
396
397 /*
398 * If reached the top, return to the original directory, and
399 * load the paths for the next root.
400 */
401 if (p->fts_level == FTS_ROOTLEVEL) {
402 if (FCHDIR(sp, sp->fts_rfd)) {
403 SET(FTS_STOP);
404 return (NULL);
405 }
406 fts_load(sp, p);
407 return (sp->fts_cur = p);
408 }
409
410 /*
411 * User may have called fts_set on the node. If skipped,
412 * ignore. If followed, get a file descriptor so we can
413 * get back if necessary.
414 */
415 if (p->fts_instr == FTS_SKIP)
416 goto next;
417 if (p->fts_instr == FTS_FOLLOW) {
418 p->fts_info = fts_stat(sp, p, 1);
419 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
420 if ((p->fts_symfd =
421 open(".", O_RDONLY, 0)) < 0) {
422 p->fts_errno = errno;
423 p->fts_info = FTS_ERR;
424 } else
425 p->fts_flags |= FTS_SYMFOLLOW;
426 }
427 p->fts_instr = FTS_NOINSTR;
428 }
429
430 name: t = sp->fts_path + NAPPEND(p->fts_parent);
431 *t++ = '/';
432 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1));
433 return (sp->fts_cur = p);
434 }
435
436 /* Move up to the parent node. */
437 p = tmp->fts_parent;
438 free(tmp);
439
440 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
441 /*
442 * Done; free everything up and set errno to 0 so the user
443 * can distinguish between error and EOF.
444 */
445 free(p);
446 errno = 0;
447 return (sp->fts_cur = NULL);
448 }
449
450 /* Nul terminate the pathname. */
451 sp->fts_path[p->fts_pathlen] = '\0';
452
453 /*
454 * Return to the parent directory. If at a root node or came through
455 * a symlink, go back through the file descriptor. Otherwise, cd up
456 * one directory.
457 */
458 if (p->fts_level == FTS_ROOTLEVEL) {
459 if (FCHDIR(sp, sp->fts_rfd)) {
460 SET(FTS_STOP);
461 return (NULL);
462 }
463 } else if (p->fts_flags & FTS_SYMFOLLOW) {
464 if (FCHDIR(sp, p->fts_symfd)) {
465 saved_errno = errno;
466 (void)close(p->fts_symfd);
467 errno = saved_errno;
468 SET(FTS_STOP);
469 return (NULL);
470 }
471 (void)close(p->fts_symfd);
472 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
473 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
474 SET(FTS_STOP);
475 return (NULL);
476 }
477 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
478 return (sp->fts_cur = p);
479 }
480
481 /*
482 * Fts_set takes the stream as an argument although it's not used in this
483 * implementation; it would be necessary if anyone wanted to add global
484 * semantics to fts using fts_set. An error return is allowed for similar
485 * reasons.
486 */
487 /* ARGSUSED */
488 int
fts_set_compat(FTS * sp,FTSENT * p,int instr)489 fts_set_compat(FTS *sp, FTSENT *p, int instr)
490 {
491
492 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
493 instr != FTS_NOINSTR && instr != FTS_SKIP) {
494 errno = EINVAL;
495 return (1);
496 }
497 p->fts_instr = instr;
498 return (0);
499 }
500
501 FTSENT *
fts_children_compat(FTS * sp,int instr)502 fts_children_compat(FTS *sp, int instr)
503 {
504 FTSENT *p;
505 int fd;
506
507 if (instr && instr != FTS_NAMEONLY) {
508 errno = EINVAL;
509 return (NULL);
510 }
511
512 /* Set current node pointer. */
513 p = sp->fts_cur;
514
515 /*
516 * Errno set to 0 so user can distinguish empty directory from
517 * an error.
518 */
519 errno = 0;
520
521 /* Fatal errors stop here. */
522 if (ISSET(FTS_STOP))
523 return (NULL);
524
525 /* Return logical hierarchy of user's arguments. */
526 if (p->fts_info == FTS_INIT)
527 return (p->fts_link);
528
529 /*
530 * If not a directory being visited in pre-order, stop here. Could
531 * allow FTS_DNR, assuming the user has fixed the problem, but the
532 * same effect is available with FTS_AGAIN.
533 */
534 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
535 return (NULL);
536
537 /* Free up any previous child list. */
538 if (sp->fts_child)
539 fts_lfree(sp->fts_child);
540
541 if (instr == FTS_NAMEONLY) {
542 SET(FTS_NAMEONLY);
543 instr = BNAMES;
544 } else
545 instr = BCHILD;
546
547 /*
548 * If using chdir on a relative path and called BEFORE fts_read does
549 * its chdir to the root of a traversal, we can lose -- we need to
550 * chdir into the subdirectory, and we don't know where the current
551 * directory is, so we can't get back so that the upcoming chdir by
552 * fts_read will work.
553 */
554 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
555 ISSET(FTS_NOCHDIR))
556 return (sp->fts_child = fts_build(sp, instr));
557
558 if ((fd = open(".", O_RDONLY, 0)) < 0)
559 return (sp->fts_child = NULL);
560 sp->fts_child = fts_build(sp, instr);
561 if (fchdir(fd)) {
562 (void)close(fd);
563 return (NULL);
564 }
565 (void)close(fd);
566 return (sp->fts_child);
567 }
568
569 /*
570 * This is the tricky part -- do not casually change *anything* in here. The
571 * idea is to build the linked list of entries that are used by fts_children
572 * and fts_read. There are lots of special cases.
573 *
574 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
575 * set and it's a physical walk (so that symbolic links can't be directories),
576 * we can do things quickly. First, if it's a 4.4BSD file system, the type
577 * of the file is in the directory entry. Otherwise, we assume that the number
578 * of subdirectories in a node is equal to the number of links to the parent.
579 * The former skips all stat calls. The latter skips stat calls in any leaf
580 * directories and for any files after the subdirectories in the directory have
581 * been found, cutting the stat calls by about 2/3.
582 */
583 static FTSENT *
fts_build(FTS * sp,int type)584 fts_build(FTS *sp, int type)
585 {
586 struct dirent *dp;
587 FTSENT *p, *head;
588 size_t nitems;
589 FTSENT *cur, *tail;
590 DIR *dirp;
591 int adjust, cderrno, descend, len, level, nlinks, saved_errno, nostat;
592 size_t maxlen;
593 #ifdef FTS_WHITEOUT
594 int oflag;
595 #endif
596 char *cp = NULL; /* pacify gcc */
597
598 /* Set current node pointer. */
599 cur = sp->fts_cur;
600
601 /*
602 * Open the directory for reading. If this fails, we're done.
603 * If being called from fts_read, set the fts_info field.
604 */
605 #ifdef FTS_WHITEOUT
606 if (ISSET(FTS_WHITEOUT))
607 oflag = DTF_NODUP|DTF_REWIND;
608 else
609 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND;
610 #else
611 #define __opendir2(path, flag) opendir(path)
612 #endif
613 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
614 if (type == BREAD) {
615 cur->fts_info = FTS_DNR;
616 cur->fts_errno = errno;
617 }
618 return (NULL);
619 }
620
621 /*
622 * Nlinks is the number of possible entries of type directory in the
623 * directory if we're cheating on stat calls, 0 if we're not doing
624 * any stat calls at all, -1 if we're doing stats on everything.
625 */
626 if (type == BNAMES) {
627 nlinks = 0;
628 nostat = 1;
629 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
630 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);
631 nostat = 1;
632 } else {
633 nlinks = -1;
634 nostat = 0;
635 }
636
637 #ifdef notdef
638 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);
639 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",
640 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));
641 #endif
642 /*
643 * If we're going to need to stat anything or we want to descend
644 * and stay in the directory, chdir. If this fails we keep going,
645 * but set a flag so we don't chdir after the post-order visit.
646 * We won't be able to stat anything, but we can still return the
647 * names themselves. Note, that since fts_read won't be able to
648 * chdir into the directory, it will have to return different path
649 * names than before, i.e. "a/b" instead of "b". Since the node
650 * has already been visited in pre-order, have to wait until the
651 * post-order visit to return the error. There is a special case
652 * here, if there was nothing to stat then it's not an error to
653 * not be able to stat. This is all fairly nasty. If a program
654 * needed sorted entries or stat information, they had better be
655 * checking FTS_NS on the returned nodes.
656 */
657 cderrno = 0;
658 if (nlinks || type == BREAD) {
659 if (fts_safe_changedir(sp, cur, -1, cur->fts_accpath)) {
660 if (nlinks && type == BREAD)
661 cur->fts_errno = errno;
662 cur->fts_flags |= FTS_DONTCHDIR;
663 descend = 0;
664 cderrno = errno;
665 } else
666 descend = 1;
667 } else
668 descend = 0;
669
670 /*
671 * Figure out the max file name length that can be stored in the
672 * current path -- the inner loop allocates more path as necessary.
673 * We really wouldn't have to do the maxlen calculations here, we
674 * could do them in fts_read before returning the path, but it's a
675 * lot easier here since the length is part of the dirent structure.
676 *
677 * If not changing directories set a pointer so that can just append
678 * each new name into the path.
679 */
680 len = NAPPEND(cur);
681 if (ISSET(FTS_NOCHDIR)) {
682 cp = sp->fts_path + len;
683 *cp++ = '/';
684 }
685 len++;
686 maxlen = sp->fts_pathlen - len;
687
688 level = cur->fts_level + 1;
689
690 /* Read the directory, attaching each entry to the `link' pointer. */
691 adjust = 0;
692 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) {
693 size_t dlen;
694
695 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
696 continue;
697
698 dlen = NAMLEN(dp);
699 /*
700 #if !defined(DIRENT_MISSING_D_NAMLEN)
701 dlen = dp->d_namlen;
702 #else
703 dlen = strlen(dp->d_name);
704 #endif
705 */
706 if ((p = fts_alloc(sp, dp->d_name, dlen)) == NULL)
707 goto mem1;
708 if (dlen >= maxlen) { /* include space for NUL */
709 if (fts_palloc(sp, len + dlen + 1)) {
710 /*
711 * No more memory for path or structures. Save
712 * errno, free up the current structure and the
713 * structures already allocated.
714 */
715 mem1: saved_errno = errno;
716 if (p)
717 free(p);
718 fts_lfree(head);
719 (void)closedir(dirp);
720 errno = saved_errno;
721 cur->fts_info = FTS_ERR;
722 SET(FTS_STOP);
723 return (NULL);
724 }
725 adjust = 1;
726 if (ISSET(FTS_NOCHDIR))
727 cp = sp->fts_path + len;
728 maxlen = sp->fts_pathlen - len;
729 }
730
731 p->fts_pathlen = len + dlen;
732 p->fts_parent = sp->fts_cur;
733 p->fts_level = level;
734
735 #ifdef FTS_WHITEOUT
736 if (dp->d_type == DT_WHT)
737 p->fts_flags |= FTS_ISW;
738 #endif
739
740 if (cderrno) {
741 if (nlinks) {
742 p->fts_info = FTS_NS;
743 p->fts_errno = cderrno;
744 } else
745 p->fts_info = FTS_NSOK;
746 p->fts_accpath = cur->fts_accpath;
747 } else if (nlinks == 0
748 #ifdef DT_DIR
749 || (nostat &&
750 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
751 #endif
752 ) {
753 p->fts_accpath =
754 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
755 p->fts_info = FTS_NSOK;
756 } else {
757 /* Build a file name for fts_stat to stat. */
758 if (ISSET(FTS_NOCHDIR)) {
759 p->fts_accpath = p->fts_path;
760 memmove(cp, p->fts_name,
761 (size_t)(p->fts_namelen + 1));
762 } else
763 p->fts_accpath = p->fts_name;
764 /* Stat it. */
765 p->fts_info = fts_stat(sp, p, 0);
766
767 /* Decrement link count if applicable. */
768 if (nlinks > 0 && (p->fts_info == FTS_D ||
769 p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
770 --nlinks;
771 }
772
773 /* We walk in directory order so "ls -f" doesn't get upset. */
774 p->fts_link = NULL;
775 if (head == NULL)
776 head = tail = p;
777 else {
778 tail->fts_link = p;
779 tail = p;
780 }
781 ++nitems;
782 }
783 (void)closedir(dirp);
784
785 /*
786 * If had to realloc the path, adjust the addresses for the rest
787 * of the tree.
788 */
789 if (adjust)
790 fts_padjust(sp, head);
791
792 /*
793 * If not changing directories, reset the path back to original
794 * state.
795 */
796 if (ISSET(FTS_NOCHDIR)) {
797 if (cp - 1 > sp->fts_path)
798 --cp;
799 *cp = '\0';
800 }
801
802 /*
803 * If descended after called from fts_children or after called from
804 * fts_read and nothing found, get back. At the root level we use
805 * the saved fd; if one of fts_open()'s arguments is a relative path
806 * to an empty directory, we wind up here with no other way back. If
807 * can't get back, we're done.
808 */
809 if (descend && (type == BCHILD || !nitems) &&
810 (cur->fts_level == FTS_ROOTLEVEL ?
811 FCHDIR(sp, sp->fts_rfd) :
812 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
813 cur->fts_info = FTS_ERR;
814 SET(FTS_STOP);
815 return (NULL);
816 }
817
818 /* If didn't find anything, return NULL. */
819 if (!nitems) {
820 if (type == BREAD)
821 cur->fts_info = FTS_DP;
822 return (NULL);
823 }
824
825 /* Sort the entries. */
826 if (sp->fts_compar && nitems > 1)
827 head = fts_sort(sp, head, nitems);
828 return (head);
829 }
830
831 static u_short
fts_stat(FTS * sp,FTSENT * p,int follow)832 fts_stat(FTS *sp, FTSENT *p, int follow)
833 {
834 FTSENT *t;
835 dev_t dev;
836 ino_t ino;
837 struct STAT *sbp, sb;
838 int saved_errno;
839
840 /* If user needs stat info, stat buffer already allocated. */
841 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;
842
843 #ifdef FTS_WHITEOUT
844 /* check for whiteout */
845 if (p->fts_flags & FTS_ISW) {
846 if (sbp != &sb) {
847 memset(sbp, '\0', sizeof (*sbp));
848 sbp->st_mode = S_IFWHT;
849 }
850 return (FTS_W);
851 }
852 #endif
853
854 /*
855 * If doing a logical walk, or application requested FTS_FOLLOW, do
856 * a stat(2). If that fails, check for a non-existent symlink. If
857 * fail, set the errno from the stat call.
858 */
859 if (ISSET(FTS_LOGICAL) || follow) {
860 if (stat(p->fts_accpath, sbp)) {
861 saved_errno = errno;
862 if (!lstat(p->fts_accpath, sbp)) {
863 errno = 0;
864 return (FTS_SLNONE);
865 }
866 p->fts_errno = saved_errno;
867 goto err;
868 }
869 } else if (lstat(p->fts_accpath, sbp)) {
870 p->fts_errno = errno;
871 err: memset(sbp, 0, sizeof(struct STAT));
872 return (FTS_NS);
873 }
874
875 if (S_ISDIR(sbp->st_mode)) {
876 /*
877 * Set the device/inode. Used to find cycles and check for
878 * crossing mount points. Also remember the link count, used
879 * in fts_build to limit the number of stat calls. It is
880 * understood that these fields are only referenced if fts_info
881 * is set to FTS_D.
882 */
883 dev = p->fts_dev = sbp->st_dev;
884 ino = p->fts_ino = sbp->st_ino;
885 p->fts_nlink = sbp->st_nlink;
886
887 if (ISDOT(p->fts_name))
888 return (FTS_DOT);
889
890 /*
891 * Cycle detection is done by brute force when the directory
892 * is first encountered. If the tree gets deep enough or the
893 * number of symbolic links to directories is high enough,
894 * something faster might be worthwhile.
895 */
896 for (t = p->fts_parent;
897 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
898 if (ino == t->fts_ino && dev == t->fts_dev) {
899 p->fts_cycle = t;
900 return (FTS_DC);
901 }
902 return (FTS_D);
903 }
904 if (S_ISLNK(sbp->st_mode))
905 return (FTS_SL);
906 if (S_ISREG(sbp->st_mode))
907 return (FTS_F);
908 return (FTS_DEFAULT);
909 }
910
911 static FTSENT *
fts_sort(FTS * sp,FTSENT * head,size_t nitems)912 fts_sort(FTS *sp, FTSENT *head, size_t nitems)
913 {
914 FTSENT **ap, *p;
915
916 /*
917 * Construct an array of pointers to the structures and call qsort(3).
918 * Reassemble the array in the order returned by qsort. If unable to
919 * sort for memory reasons, return the directory entries in their
920 * current order. Allocate enough space for the current needs plus
921 * 40 so don't realloc one entry at a time.
922 */
923 if (nitems > sp->fts_nitems) {
924 FTSENT **new;
925
926 new = realloc(sp->fts_array, sizeof(FTSENT *) * (nitems + 40));
927 if (new == 0)
928 return (head);
929 sp->fts_array = new;
930 sp->fts_nitems = nitems + 40;
931 }
932 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
933 *ap++ = p;
934 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *),
935 (int (*)(const void *, const void *))sp->fts_compar);
936 for (head = *(ap = sp->fts_array); --nitems; ++ap)
937 ap[0]->fts_link = ap[1];
938 ap[0]->fts_link = NULL;
939 return (head);
940 }
941
942 static FTSENT *
fts_alloc(FTS * sp,const char * name,size_t namelen)943 fts_alloc(FTS *sp, const char *name, size_t namelen)
944 {
945 FTSENT *p;
946
947 #ifndef ALIGNBYTES
948 #define ALIGNBYTES (sizeof(int) - 1)
949 #endif
950
951 #ifndef ALIGN
952 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
953 #endif
954
955 size_t len;
956 /*
957 * The file name is a variable length array and no stat structure is
958 * necessary if the user has set the nostat bit. Allocate the FTSENT
959 * structure, the file name and the stat structure in one chunk, but
960 * be careful that the stat structure is reasonably aligned. Since the
961 * fts_name field is declared to be of size 1, the fts_name pointer is
962 * namelen + 2 before the first possible address of the stat structure.
963 */
964 len = sizeof(FTSENT) + namelen;
965 if (!ISSET(FTS_NOSTAT))
966 len += sizeof(struct STAT) + ALIGNBYTES;
967 if ((p = malloc(len)) == NULL)
968 return (NULL);
969
970 if (!ISSET(FTS_NOSTAT))
971 p->fts_statp =
972 (struct STAT *)ALIGN((u_long)(p->fts_name + namelen + 2));
973
974 /* Copy the name plus the trailing NULL. */
975 memmove(p->fts_name, name, namelen + 1);
976
977 p->fts_namelen = namelen;
978 p->fts_path = sp->fts_path;
979 p->fts_errno = 0;
980 p->fts_flags = 0;
981 p->fts_instr = FTS_NOINSTR;
982 p->fts_number = 0;
983 p->fts_pointer = NULL;
984 return (p);
985 }
986
987 static void
fts_lfree(FTSENT * head)988 fts_lfree(FTSENT *head)
989 {
990 FTSENT *p;
991
992 /* XXX: head may be NULL ? */
993
994 /* Free a linked list of structures. */
995 while ((p = head) != NULL) {
996 head = head->fts_link;
997
998 free(p);
999 }
1000 }
1001
1002 static size_t
fts_pow2(size_t x)1003 fts_pow2(size_t x)
1004 {
1005
1006 x--;
1007 x |= x>>1;
1008 x |= x>>2;
1009 x |= x>>4;
1010 x |= x>>8;
1011 x |= x>>16;
1012 #if LONG_BIT > 32
1013 x |= x>>32;
1014 #endif
1015 #if LONG_BIT > 64
1016 x |= x>>64;
1017 #endif
1018 x++;
1019 return (x);
1020 }
1021
1022 /*
1023 * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
1024 * Most systems will allow creation of paths much longer than MAXPATHLEN, even
1025 * though the kernel won't resolve them. Round up the new size to a power of 2,
1026 * so we don't realloc the path 2 bytes at a time.
1027 */
1028 static int
fts_palloc(FTS * sp,size_t size)1029 fts_palloc(FTS *sp, size_t size)
1030 {
1031 char *new;
1032
1033 #if 1
1034 /* Protect against fts_pathlen overflow. */
1035 if (size > USHRT_MAX + 1) {
1036 errno = ENOMEM;
1037 return (1);
1038 }
1039 #endif
1040 size = fts_pow2(size);
1041 new = realloc(sp->fts_path, size);
1042 if (new == 0)
1043 return (1);
1044 sp->fts_path = new;
1045 sp->fts_pathlen = size;
1046 return (0);
1047 }
1048
1049 /*
1050 * When the path is realloc'd, have to fix all of the pointers in structures
1051 * already returned.
1052 */
1053 static void
fts_padjust(FTS * sp,FTSENT * head)1054 fts_padjust(FTS *sp, FTSENT *head)
1055 {
1056 FTSENT *p;
1057 char *addr;
1058
1059 #define ADJUST(p) do { \
1060 if ((p)->fts_accpath != (p)->fts_name) \
1061 (p)->fts_accpath = \
1062 addr + ((p)->fts_accpath - (p)->fts_path); \
1063 (p)->fts_path = addr; \
1064 } while (/*CONSTCOND*/0)
1065
1066 addr = sp->fts_path;
1067
1068 /* Adjust the current set of children. */
1069 for (p = sp->fts_child; p; p = p->fts_link)
1070 ADJUST(p);
1071
1072 /* Adjust the rest of the tree, including the current level. */
1073 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1074 ADJUST(p);
1075 p = p->fts_link ? p->fts_link : p->fts_parent;
1076 }
1077 }
1078
1079 static size_t
fts_maxarglen(argv)1080 fts_maxarglen(argv)
1081 char * const *argv;
1082 {
1083 size_t len, max;
1084
1085 for (max = 0; *argv; ++argv)
1086 if ((len = strlen(*argv)) > max)
1087 max = len;
1088 return (max + 1);
1089 }
1090
1091 /*
1092 * Change to dir specified by fd or p->fts_accpath without getting
1093 * tricked by someone changing the world out from underneath us.
1094 * Assumes p->fts_dev and p->fts_ino are filled in.
1095 */
1096 static int
fts_safe_changedir(sp,p,fd,path)1097 fts_safe_changedir(sp, p, fd, path)
1098 const FTS *sp;
1099 const FTSENT *p;
1100 int fd;
1101 const char *path;
1102 {
1103 int oldfd = fd, ret = -1;
1104 struct STAT sb;
1105
1106 if (ISSET(FTS_NOCHDIR))
1107 return 0;
1108
1109 if (fd < 0 && (fd = open(path, O_RDONLY)) == -1)
1110 return -1;
1111
1112 if (fstat(fd, &sb) == -1)
1113 goto bail;
1114
1115 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) {
1116 errno = ENOENT;
1117 goto bail;
1118 }
1119
1120 ret = fchdir(fd);
1121
1122 bail:
1123 if (oldfd < 0) {
1124 int save_errno = errno;
1125 (void)close(fd);
1126 errno = save_errno;
1127 }
1128 return ret;
1129 }
1130