xref: /freebsd/sbin/fsck_msdosfs/dir.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
5  * Copyright (c) 1995 Martin Husemann
6  * Some structure declaration borrowed from Paul Popelka
7  * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 
31 #include <sys/cdefs.h>
32 #ifndef lint
33 __RCSID("$NetBSD: dir.c,v 1.20 2006/06/05 16:51:18 christos Exp $");
34 static const char rcsid[] =
35   "$FreeBSD$";
36 #endif /* not lint */
37 
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <ctype.h>
42 #include <unistd.h>
43 #include <time.h>
44 
45 #include <sys/param.h>
46 
47 #include "ext.h"
48 #include "fsutil.h"
49 
50 #define	SLOT_EMPTY	0x00		/* slot has never been used */
51 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
52 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
53 
54 #define	ATTR_NORMAL	0x00		/* normal file */
55 #define	ATTR_READONLY	0x01		/* file is readonly */
56 #define	ATTR_HIDDEN	0x02		/* file is hidden */
57 #define	ATTR_SYSTEM	0x04		/* file is a system file */
58 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
59 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
60 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
61 
62 #define	ATTR_WIN95	0x0f		/* long name record */
63 
64 /*
65  * This is the format of the contents of the deTime field in the direntry
66  * structure.
67  * We don't use bitfields because we don't know how compilers for
68  * arbitrary machines will lay them out.
69  */
70 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
71 #define DT_2SECONDS_SHIFT	0
72 #define DT_MINUTES_MASK		0x7E0	/* minutes */
73 #define DT_MINUTES_SHIFT	5
74 #define DT_HOURS_MASK		0xF800	/* hours */
75 #define DT_HOURS_SHIFT		11
76 
77 /*
78  * This is the format of the contents of the deDate field in the direntry
79  * structure.
80  */
81 #define DD_DAY_MASK		0x1F	/* day of month */
82 #define DD_DAY_SHIFT		0
83 #define DD_MONTH_MASK		0x1E0	/* month */
84 #define DD_MONTH_SHIFT		5
85 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
86 #define DD_YEAR_SHIFT		9
87 
88 
89 /* dir.c */
90 static struct dosDirEntry *newDosDirEntry(void);
91 static void freeDosDirEntry(struct dosDirEntry *);
92 static struct dirTodoNode *newDirTodo(void);
93 static void freeDirTodo(struct dirTodoNode *);
94 static char *fullpath(struct dosDirEntry *);
95 static u_char calcShortSum(u_char *);
96 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
97     cl_t, int, int);
98 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
99     u_char *, cl_t, cl_t, cl_t, char *, int);
100 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
101     struct dosDirEntry *);
102 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
103     struct dosDirEntry *);
104 
105 /*
106  * Manage free dosDirEntry structures.
107  */
108 static struct dosDirEntry *freede;
109 
110 static struct dosDirEntry *
111 newDosDirEntry(void)
112 {
113 	struct dosDirEntry *de;
114 
115 	if (!(de = freede)) {
116 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
117 			return 0;
118 	} else
119 		freede = de->next;
120 	return de;
121 }
122 
123 static void
124 freeDosDirEntry(struct dosDirEntry *de)
125 {
126 	de->next = freede;
127 	freede = de;
128 }
129 
130 /*
131  * The same for dirTodoNode structures.
132  */
133 static struct dirTodoNode *freedt;
134 
135 static struct dirTodoNode *
136 newDirTodo(void)
137 {
138 	struct dirTodoNode *dt;
139 
140 	if (!(dt = freedt)) {
141 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
142 			return 0;
143 	} else
144 		freedt = dt->next;
145 	return dt;
146 }
147 
148 static void
149 freeDirTodo(struct dirTodoNode *dt)
150 {
151 	dt->next = freedt;
152 	freedt = dt;
153 }
154 
155 /*
156  * The stack of unread directories
157  */
158 static struct dirTodoNode *pendingDirectories = NULL;
159 
160 /*
161  * Return the full pathname for a directory entry.
162  */
163 static char *
164 fullpath(struct dosDirEntry *dir)
165 {
166 	static char namebuf[MAXPATHLEN + 1];
167 	char *cp, *np;
168 	int nl;
169 
170 	cp = namebuf + sizeof namebuf - 1;
171 	*cp = '\0';
172 	do {
173 		np = dir->lname[0] ? dir->lname : dir->name;
174 		nl = strlen(np);
175 		if ((cp -= nl) <= namebuf + 1)
176 			break;
177 		memcpy(cp, np, nl);
178 		*--cp = '/';
179 	} while ((dir = dir->parent) != NULL);
180 	if (dir)
181 		*--cp = '?';
182 	else
183 		cp++;
184 	return cp;
185 }
186 
187 /*
188  * Calculate a checksum over an 8.3 alias name
189  */
190 static u_char
191 calcShortSum(u_char *p)
192 {
193 	u_char sum = 0;
194 	int i;
195 
196 	for (i = 0; i < 11; i++) {
197 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
198 		sum += p[i];
199 	}
200 
201 	return sum;
202 }
203 
204 /*
205  * Global variables temporarily used during a directory scan
206  */
207 static char longName[DOSLONGNAMELEN] = "";
208 static u_char *buffer = NULL;
209 static u_char *delbuf = NULL;
210 
211 static struct dosDirEntry *rootDir;
212 static struct dosDirEntry *lostDir;
213 
214 /*
215  * Init internal state for a new directory scan.
216  */
217 int
218 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
219 {
220 	int b1, b2;
221 	cl_t cl;
222 	int ret = FSOK;
223 	size_t len;
224 
225 	b1 = boot->bpbRootDirEnts * 32;
226 	b2 = boot->bpbSecPerClust * boot->bpbBytesPerSec;
227 
228 	if ((buffer = malloc(len = MAX(b1, b2))) == NULL) {
229 		perr("No space for directory buffer (%zu)", len);
230 		return FSFATAL;
231 	}
232 
233 	if ((delbuf = malloc(len = b2)) == NULL) {
234 		free(buffer);
235 		perr("No space for directory delbuf (%zu)", len);
236 		return FSFATAL;
237 	}
238 
239 	if ((rootDir = newDosDirEntry()) == NULL) {
240 		free(buffer);
241 		free(delbuf);
242 		perr("No space for directory entry");
243 		return FSFATAL;
244 	}
245 
246 	memset(rootDir, 0, sizeof *rootDir);
247 	if (boot->flags & FAT32) {
248 		if (boot->bpbRootClust < CLUST_FIRST ||
249 		    boot->bpbRootClust >= boot->NumClusters) {
250 			pfatal("Root directory starts with cluster out of range(%u)",
251 			       boot->bpbRootClust);
252 			return FSFATAL;
253 		}
254 		cl = fat[boot->bpbRootClust].next;
255 		if (cl < CLUST_FIRST
256 		    || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
257 		    || fat[boot->bpbRootClust].head != boot->bpbRootClust) {
258 			if (cl == CLUST_FREE)
259 				pwarn("Root directory starts with free cluster\n");
260 			else if (cl >= CLUST_RSRVD)
261 				pwarn("Root directory starts with cluster marked %s\n",
262 				      rsrvdcltype(cl));
263 			else {
264 				pfatal("Root directory doesn't start a cluster chain");
265 				return FSFATAL;
266 			}
267 			if (ask(1, "Fix")) {
268 				fat[boot->bpbRootClust].next = CLUST_FREE;
269 				ret = FSFATMOD;
270 			} else
271 				ret = FSFATAL;
272 		}
273 
274 		fat[boot->bpbRootClust].flags |= FAT_USED;
275 		rootDir->head = boot->bpbRootClust;
276 	}
277 
278 	return ret;
279 }
280 
281 /*
282  * Cleanup after a directory scan
283  */
284 void
285 finishDosDirSection(void)
286 {
287 	struct dirTodoNode *p, *np;
288 	struct dosDirEntry *d, *nd;
289 
290 	for (p = pendingDirectories; p; p = np) {
291 		np = p->next;
292 		freeDirTodo(p);
293 	}
294 	pendingDirectories = NULL;
295 	for (d = rootDir; d; d = nd) {
296 		if ((nd = d->child) != NULL) {
297 			d->child = 0;
298 			continue;
299 		}
300 		if (!(nd = d->next))
301 			nd = d->parent;
302 		freeDosDirEntry(d);
303 	}
304 	rootDir = lostDir = NULL;
305 	free(buffer);
306 	free(delbuf);
307 	buffer = NULL;
308 	delbuf = NULL;
309 }
310 
311 /*
312  * Delete directory entries between startcl, startoff and endcl, endoff.
313  */
314 static int
315 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
316     int startoff, cl_t endcl, int endoff, int notlast)
317 {
318 	u_char *s, *e;
319 	off_t off;
320 	int clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
321 
322 	s = delbuf + startoff;
323 	e = delbuf + clsz;
324 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
325 		if (startcl == endcl) {
326 			if (notlast)
327 				break;
328 			e = delbuf + endoff;
329 		}
330 		off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
331 		off *= boot->bpbBytesPerSec;
332 		if (lseek(f, off, SEEK_SET) != off
333 		    || read(f, delbuf, clsz) != clsz) {
334 			perr("Unable to read directory");
335 			return FSFATAL;
336 		}
337 		while (s < e) {
338 			*s = SLOT_DELETED;
339 			s += 32;
340 		}
341 		if (lseek(f, off, SEEK_SET) != off
342 		    || write(f, delbuf, clsz) != clsz) {
343 			perr("Unable to write directory");
344 			return FSFATAL;
345 		}
346 		if (startcl == endcl)
347 			break;
348 		startcl = fat[startcl].next;
349 		s = delbuf;
350 	}
351 	return FSOK;
352 }
353 
354 static int
355 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
356     u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
357 {
358 	switch (type) {
359 	case 0:
360 		pwarn("Invalid long filename entry for %s\n", path);
361 		break;
362 	case 1:
363 		pwarn("Invalid long filename entry at end of directory %s\n",
364 		    path);
365 		break;
366 	case 2:
367 		pwarn("Invalid long filename entry for volume label\n");
368 		break;
369 	}
370 	if (ask(0, "Remove")) {
371 		if (startcl != curcl) {
372 			if (delete(f, boot, fat,
373 				   startcl, start - buffer,
374 				   endcl, end - buffer,
375 				   endcl == curcl) == FSFATAL)
376 				return FSFATAL;
377 			start = buffer;
378 		}
379 		/* startcl is < CLUST_FIRST for !fat32 root */
380 		if ((endcl == curcl) || (startcl < CLUST_FIRST))
381 			for (; start < end; start += 32)
382 				*start = SLOT_DELETED;
383 		return FSDIRMOD;
384 	}
385 	return FSERROR;
386 }
387 
388 /*
389  * Check an in-memory file entry
390  */
391 static int
392 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
393     struct dosDirEntry *dir)
394 {
395 	/*
396 	 * Check size on ordinary files
397 	 */
398 	u_int32_t physicalSize;
399 
400 	if (dir->head == CLUST_FREE)
401 		physicalSize = 0;
402 	else {
403 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
404 			return FSERROR;
405 		physicalSize = fat[dir->head].length * boot->ClusterSize;
406 	}
407 	if (physicalSize < dir->size) {
408 		pwarn("size of %s is %u, should at most be %u\n",
409 		      fullpath(dir), dir->size, physicalSize);
410 		if (ask(1, "Truncate")) {
411 			dir->size = physicalSize;
412 			p[28] = (u_char)physicalSize;
413 			p[29] = (u_char)(physicalSize >> 8);
414 			p[30] = (u_char)(physicalSize >> 16);
415 			p[31] = (u_char)(physicalSize >> 24);
416 			return FSDIRMOD;
417 		} else
418 			return FSERROR;
419 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
420 		pwarn("%s has too many clusters allocated\n",
421 		      fullpath(dir));
422 		if (ask(1, "Drop superfluous clusters")) {
423 			cl_t cl;
424 			u_int32_t sz, len;
425 
426 			for (cl = dir->head, len = sz = 0;
427 			    (sz += boot->ClusterSize) < dir->size; len++)
428 				cl = fat[cl].next;
429 			clearchain(boot, fat, fat[cl].next);
430 			fat[cl].next = CLUST_EOF;
431 			fat[dir->head].length = len;
432 			return FSFATMOD;
433 		} else
434 			return FSERROR;
435 	}
436 	return FSOK;
437 }
438 
439 /*
440  * Read a directory and
441  *   - resolve long name records
442  *   - enter file and directory records into the parent's list
443  *   - push directories onto the todo-stack
444  */
445 static int
446 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
447     struct dosDirEntry *dir)
448 {
449 	struct dosDirEntry dirent, *d;
450 	u_char *p, *vallfn, *invlfn, *empty;
451 	off_t off;
452 	int i, j, k, last;
453 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
454 	char *t;
455 	u_int lidx = 0;
456 	int shortSum;
457 	int mod = FSOK;
458 #define	THISMOD	0x8000			/* Only used within this routine */
459 
460 	cl = dir->head;
461 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
462 		/*
463 		 * Already handled somewhere else.
464 		 */
465 		return FSOK;
466 	}
467 	shortSum = -1;
468 	vallfn = invlfn = empty = NULL;
469 	do {
470 		if (!(boot->flags & FAT32) && !dir->parent) {
471 			last = boot->bpbRootDirEnts * 32;
472 			off = boot->bpbResSectors + boot->bpbFATs *
473 			    boot->FATsecs;
474 		} else {
475 			last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
476 			off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
477 		}
478 
479 		off *= boot->bpbBytesPerSec;
480 		if (lseek(f, off, SEEK_SET) != off
481 		    || read(f, buffer, last) != last) {
482 			perr("Unable to read directory");
483 			return FSFATAL;
484 		}
485 		last /= 32;
486 		/*
487 		 * Check `.' and `..' entries here?			XXX
488 		 */
489 		for (p = buffer, i = 0; i < last; i++, p += 32) {
490 			if (dir->fsckflags & DIREMPWARN) {
491 				*p = SLOT_EMPTY;
492 				continue;
493 			}
494 
495 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
496 				if (*p == SLOT_EMPTY) {
497 					dir->fsckflags |= DIREMPTY;
498 					empty = p;
499 					empcl = cl;
500 				}
501 				continue;
502 			}
503 
504 			if (dir->fsckflags & DIREMPTY) {
505 				if (!(dir->fsckflags & DIREMPWARN)) {
506 					pwarn("%s has entries after end of directory\n",
507 					      fullpath(dir));
508 					if (ask(1, "Extend")) {
509 						u_char *q;
510 
511 						dir->fsckflags &= ~DIREMPTY;
512 						if (delete(f, boot, fat,
513 							   empcl, empty - buffer,
514 							   cl, p - buffer, 1) == FSFATAL)
515 							return FSFATAL;
516 						q = empcl == cl ? empty : buffer;
517 						for (; q < p; q += 32)
518 							*q = SLOT_DELETED;
519 						mod |= THISMOD|FSDIRMOD;
520 					} else if (ask(0, "Truncate"))
521 						dir->fsckflags |= DIREMPWARN;
522 				}
523 				if (dir->fsckflags & DIREMPWARN) {
524 					*p = SLOT_DELETED;
525 					mod |= THISMOD|FSDIRMOD;
526 					continue;
527 				} else if (dir->fsckflags & DIREMPTY)
528 					mod |= FSERROR;
529 				empty = NULL;
530 			}
531 
532 			if (p[11] == ATTR_WIN95) {
533 				if (*p & LRFIRST) {
534 					if (shortSum != -1) {
535 						if (!invlfn) {
536 							invlfn = vallfn;
537 							invcl = valcl;
538 						}
539 					}
540 					memset(longName, 0, sizeof longName);
541 					shortSum = p[13];
542 					vallfn = p;
543 					valcl = cl;
544 				} else if (shortSum != p[13]
545 					   || lidx != (*p & LRNOMASK)) {
546 					if (!invlfn) {
547 						invlfn = vallfn;
548 						invcl = valcl;
549 					}
550 					if (!invlfn) {
551 						invlfn = p;
552 						invcl = cl;
553 					}
554 					vallfn = NULL;
555 				}
556 				lidx = *p & LRNOMASK;
557 				t = longName + --lidx * 13;
558 				for (k = 1; k < 11 && t < longName +
559 				    sizeof(longName); k += 2) {
560 					if (!p[k] && !p[k + 1])
561 						break;
562 					*t++ = p[k];
563 					/*
564 					 * Warn about those unusable chars in msdosfs here?	XXX
565 					 */
566 					if (p[k + 1])
567 						t[-1] = '?';
568 				}
569 				if (k >= 11)
570 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
571 						if (!p[k] && !p[k + 1])
572 							break;
573 						*t++ = p[k];
574 						if (p[k + 1])
575 							t[-1] = '?';
576 					}
577 				if (k >= 26)
578 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
579 						if (!p[k] && !p[k + 1])
580 							break;
581 						*t++ = p[k];
582 						if (p[k + 1])
583 							t[-1] = '?';
584 					}
585 				if (t >= longName + sizeof(longName)) {
586 					pwarn("long filename too long\n");
587 					if (!invlfn) {
588 						invlfn = vallfn;
589 						invcl = valcl;
590 					}
591 					vallfn = NULL;
592 				}
593 				if (p[26] | (p[27] << 8)) {
594 					pwarn("long filename record cluster start != 0\n");
595 					if (!invlfn) {
596 						invlfn = vallfn;
597 						invcl = cl;
598 					}
599 					vallfn = NULL;
600 				}
601 				continue;	/* long records don't carry further
602 						 * information */
603 			}
604 
605 			/*
606 			 * This is a standard msdosfs directory entry.
607 			 */
608 			memset(&dirent, 0, sizeof dirent);
609 
610 			/*
611 			 * it's a short name record, but we need to know
612 			 * more, so get the flags first.
613 			 */
614 			dirent.flags = p[11];
615 
616 			/*
617 			 * Translate from 850 to ISO here		XXX
618 			 */
619 			for (j = 0; j < 8; j++)
620 				dirent.name[j] = p[j];
621 			dirent.name[8] = '\0';
622 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
623 				dirent.name[k] = '\0';
624 			if (k < 0 || dirent.name[k] != '\0')
625 				k++;
626 			if (dirent.name[0] == SLOT_E5)
627 				dirent.name[0] = 0xe5;
628 
629 			if (dirent.flags & ATTR_VOLUME) {
630 				if (vallfn || invlfn) {
631 					mod |= removede(f, boot, fat,
632 							invlfn ? invlfn : vallfn, p,
633 							invlfn ? invcl : valcl, -1, 0,
634 							fullpath(dir), 2);
635 					vallfn = NULL;
636 					invlfn = NULL;
637 				}
638 				continue;
639 			}
640 
641 			if (p[8] != ' ')
642 				dirent.name[k++] = '.';
643 			for (j = 0; j < 3; j++)
644 				dirent.name[k++] = p[j+8];
645 			dirent.name[k] = '\0';
646 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
647 				dirent.name[k] = '\0';
648 
649 			if (vallfn && shortSum != calcShortSum(p)) {
650 				if (!invlfn) {
651 					invlfn = vallfn;
652 					invcl = valcl;
653 				}
654 				vallfn = NULL;
655 			}
656 			dirent.head = p[26] | (p[27] << 8);
657 			if (boot->ClustMask == CLUST32_MASK)
658 				dirent.head |= (p[20] << 16) | (p[21] << 24);
659 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
660 			if (vallfn) {
661 				strlcpy(dirent.lname, longName,
662 				    sizeof(dirent.lname));
663 				longName[0] = '\0';
664 				shortSum = -1;
665 			}
666 
667 			dirent.parent = dir;
668 			dirent.next = dir->child;
669 
670 			if (invlfn) {
671 				mod |= k = removede(f, boot, fat,
672 						    invlfn, vallfn ? vallfn : p,
673 						    invcl, vallfn ? valcl : cl, cl,
674 						    fullpath(&dirent), 0);
675 				if (mod & FSFATAL)
676 					return FSFATAL;
677 				if (vallfn
678 				    ? (valcl == cl && vallfn != buffer)
679 				    : p != buffer)
680 					if (k & FSDIRMOD)
681 						mod |= THISMOD;
682 			}
683 
684 			vallfn = NULL; /* not used any longer */
685 			invlfn = NULL;
686 
687 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
688 				if (dirent.head != 0) {
689 					pwarn("%s has clusters, but size 0\n",
690 					      fullpath(&dirent));
691 					if (ask(1, "Drop allocated clusters")) {
692 						p[26] = p[27] = 0;
693 						if (boot->ClustMask == CLUST32_MASK)
694 							p[20] = p[21] = 0;
695 						clearchain(boot, fat, dirent.head);
696 						dirent.head = 0;
697 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
698 					} else
699 						mod |= FSERROR;
700 				}
701 			} else if (dirent.head == 0
702 				   && !strcmp(dirent.name, "..")
703 				   && dir->parent			/* XXX */
704 				   && !dir->parent->parent) {
705 				/*
706 				 *  Do nothing, the parent is the root
707 				 */
708 			} else if (dirent.head < CLUST_FIRST
709 				   || dirent.head >= boot->NumClusters
710 				   || fat[dirent.head].next == CLUST_FREE
711 				   || (fat[dirent.head].next >= CLUST_RSRVD
712 				       && fat[dirent.head].next < CLUST_EOFS)
713 				   || fat[dirent.head].head != dirent.head) {
714 				if (dirent.head == 0)
715 					pwarn("%s has no clusters\n",
716 					      fullpath(&dirent));
717 				else if (dirent.head < CLUST_FIRST
718 					 || dirent.head >= boot->NumClusters)
719 					pwarn("%s starts with cluster out of range(%u)\n",
720 					      fullpath(&dirent),
721 					      dirent.head);
722 				else if (fat[dirent.head].next == CLUST_FREE)
723 					pwarn("%s starts with free cluster\n",
724 					      fullpath(&dirent));
725 				else if (fat[dirent.head].next >= CLUST_RSRVD)
726 					pwarn("%s starts with cluster marked %s\n",
727 					      fullpath(&dirent),
728 					      rsrvdcltype(fat[dirent.head].next));
729 				else
730 					pwarn("%s doesn't start a cluster chain\n",
731 					      fullpath(&dirent));
732 				if (dirent.flags & ATTR_DIRECTORY) {
733 					if (ask(0, "Remove")) {
734 						*p = SLOT_DELETED;
735 						mod |= THISMOD|FSDIRMOD;
736 					} else
737 						mod |= FSERROR;
738 					continue;
739 				} else {
740 					if (ask(1, "Truncate")) {
741 						p[28] = p[29] = p[30] = p[31] = 0;
742 						p[26] = p[27] = 0;
743 						if (boot->ClustMask == CLUST32_MASK)
744 							p[20] = p[21] = 0;
745 						dirent.size = 0;
746 						mod |= THISMOD|FSDIRMOD;
747 					} else
748 						mod |= FSERROR;
749 				}
750 			}
751 
752 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
753 				fat[dirent.head].flags |= FAT_USED;
754 
755 			if (dirent.flags & ATTR_DIRECTORY) {
756 				/*
757 				 * gather more info for directories
758 				 */
759 				struct dirTodoNode *n;
760 
761 				if (dirent.size) {
762 					pwarn("Directory %s has size != 0\n",
763 					      fullpath(&dirent));
764 					if (ask(1, "Correct")) {
765 						p[28] = p[29] = p[30] = p[31] = 0;
766 						dirent.size = 0;
767 						mod |= THISMOD|FSDIRMOD;
768 					} else
769 						mod |= FSERROR;
770 				}
771 				/*
772 				 * handle `.' and `..' specially
773 				 */
774 				if (strcmp(dirent.name, ".") == 0) {
775 					if (dirent.head != dir->head) {
776 						pwarn("`.' entry in %s has incorrect start cluster\n",
777 						      fullpath(dir));
778 						if (ask(1, "Correct")) {
779 							dirent.head = dir->head;
780 							p[26] = (u_char)dirent.head;
781 							p[27] = (u_char)(dirent.head >> 8);
782 							if (boot->ClustMask == CLUST32_MASK) {
783 								p[20] = (u_char)(dirent.head >> 16);
784 								p[21] = (u_char)(dirent.head >> 24);
785 							}
786 							mod |= THISMOD|FSDIRMOD;
787 						} else
788 							mod |= FSERROR;
789 					}
790 					continue;
791 				}
792 				if (strcmp(dirent.name, "..") == 0) {
793 					if (dir->parent) {		/* XXX */
794 						if (!dir->parent->parent) {
795 							if (dirent.head) {
796 								pwarn("`..' entry in %s has non-zero start cluster\n",
797 								      fullpath(dir));
798 								if (ask(1, "Correct")) {
799 									dirent.head = 0;
800 									p[26] = p[27] = 0;
801 									if (boot->ClustMask == CLUST32_MASK)
802 										p[20] = p[21] = 0;
803 									mod |= THISMOD|FSDIRMOD;
804 								} else
805 									mod |= FSERROR;
806 							}
807 						} else if (dirent.head != dir->parent->head) {
808 							pwarn("`..' entry in %s has incorrect start cluster\n",
809 							      fullpath(dir));
810 							if (ask(1, "Correct")) {
811 								dirent.head = dir->parent->head;
812 								p[26] = (u_char)dirent.head;
813 								p[27] = (u_char)(dirent.head >> 8);
814 								if (boot->ClustMask == CLUST32_MASK) {
815 									p[20] = (u_char)(dirent.head >> 16);
816 									p[21] = (u_char)(dirent.head >> 24);
817 								}
818 								mod |= THISMOD|FSDIRMOD;
819 							} else
820 								mod |= FSERROR;
821 						}
822 					}
823 					continue;
824 				}
825 
826 				/* create directory tree node */
827 				if (!(d = newDosDirEntry())) {
828 					perr("No space for directory");
829 					return FSFATAL;
830 				}
831 				memcpy(d, &dirent, sizeof(struct dosDirEntry));
832 				/* link it into the tree */
833 				dir->child = d;
834 
835 				/* Enter this directory into the todo list */
836 				if (!(n = newDirTodo())) {
837 					perr("No space for todo list");
838 					return FSFATAL;
839 				}
840 				n->next = pendingDirectories;
841 				n->dir = d;
842 				pendingDirectories = n;
843 			} else {
844 				mod |= k = checksize(boot, fat, p, &dirent);
845 				if (k & FSDIRMOD)
846 					mod |= THISMOD;
847 			}
848 			boot->NumFiles++;
849 		}
850 
851 		if (!(boot->flags & FAT32) && !dir->parent)
852 			break;
853 
854 		if (mod & THISMOD) {
855 			last *= 32;
856 			if (lseek(f, off, SEEK_SET) != off
857 			    || write(f, buffer, last) != last) {
858 				perr("Unable to write directory");
859 				return FSFATAL;
860 			}
861 			mod &= ~THISMOD;
862 		}
863 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
864 	if (invlfn || vallfn)
865 		mod |= removede(f, boot, fat,
866 				invlfn ? invlfn : vallfn, p,
867 				invlfn ? invcl : valcl, -1, 0,
868 				fullpath(dir), 1);
869 
870 	/* The root directory of non fat32 filesystems is in a special
871 	 * area and may have been modified above without being written out.
872 	 */
873 	if ((mod & FSDIRMOD) && !(boot->flags & FAT32) && !dir->parent) {
874 		last *= 32;
875 		if (lseek(f, off, SEEK_SET) != off
876 		    || write(f, buffer, last) != last) {
877 			perr("Unable to write directory");
878 			return FSFATAL;
879 		}
880 		mod &= ~THISMOD;
881 	}
882 	return mod & ~THISMOD;
883 }
884 
885 int
886 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
887 {
888 	int mod;
889 
890 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
891 	if (mod & FSFATAL)
892 		return FSFATAL;
893 
894 	/*
895 	 * process the directory todo list
896 	 */
897 	while (pendingDirectories) {
898 		struct dosDirEntry *dir = pendingDirectories->dir;
899 		struct dirTodoNode *n = pendingDirectories->next;
900 
901 		/*
902 		 * remove TODO entry now, the list might change during
903 		 * directory reads
904 		 */
905 		freeDirTodo(pendingDirectories);
906 		pendingDirectories = n;
907 
908 		/*
909 		 * handle subdirectory
910 		 */
911 		mod |= readDosDirSection(dosfs, boot, fat, dir);
912 		if (mod & FSFATAL)
913 			return FSFATAL;
914 	}
915 
916 	return mod;
917 }
918 
919 /*
920  * Try to reconnect a FAT chain into dir
921  */
922 static u_char *lfbuf;
923 static cl_t lfcl;
924 static off_t lfoff;
925 
926 int
927 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
928 {
929 	struct dosDirEntry d;
930 	int len;
931 	u_char *p;
932 
933 	if (!ask(1, "Reconnect"))
934 		return FSERROR;
935 
936 	if (!lostDir) {
937 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
938 			if (!strcmp(lostDir->name, LOSTDIR))
939 				break;
940 		}
941 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
942 			pwarn("No %s directory\n", LOSTDIR);
943 			return FSERROR;
944 		}
945 	}
946 	if (!lfbuf) {
947 		lfbuf = malloc(boot->ClusterSize);
948 		if (!lfbuf) {
949 			perr("No space for buffer");
950 			return FSFATAL;
951 		}
952 		p = NULL;
953 	} else
954 		p = lfbuf;
955 	while (1) {
956 		if (p)
957 			for (; p < lfbuf + boot->ClusterSize; p += 32)
958 				if (*p == SLOT_EMPTY
959 				    || *p == SLOT_DELETED)
960 					break;
961 		if (p && p < lfbuf + boot->ClusterSize)
962 			break;
963 		lfcl = p ? fat[lfcl].next : lostDir->head;
964 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
965 			/* Extend LOSTDIR?				XXX */
966 			pwarn("No space in %s\n", LOSTDIR);
967 			return FSERROR;
968 		}
969 		lfoff = lfcl * boot->ClusterSize
970 		    + boot->ClusterOffset * boot->bpbBytesPerSec;
971 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
972 		    || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
973 			perr("could not read LOST.DIR");
974 			return FSFATAL;
975 		}
976 		p = lfbuf;
977 	}
978 
979 	boot->NumFiles++;
980 	/* Ensure uniqueness of entry here!				XXX */
981 	memset(&d, 0, sizeof d);
982 	/* worst case -1 = 4294967295, 10 digits */
983 	len = snprintf(d.name, sizeof(d.name), "%u", head);
984 	d.flags = 0;
985 	d.head = head;
986 	d.size = fat[head].length * boot->ClusterSize;
987 
988 	memcpy(p, d.name, len);
989 	memset(p + len, ' ', 11 - len);
990 	memset(p + 11, 0, 32 - 11);
991 	p[26] = (u_char)d.head;
992 	p[27] = (u_char)(d.head >> 8);
993 	if (boot->ClustMask == CLUST32_MASK) {
994 		p[20] = (u_char)(d.head >> 16);
995 		p[21] = (u_char)(d.head >> 24);
996 	}
997 	p[28] = (u_char)d.size;
998 	p[29] = (u_char)(d.size >> 8);
999 	p[30] = (u_char)(d.size >> 16);
1000 	p[31] = (u_char)(d.size >> 24);
1001 	fat[head].flags |= FAT_USED;
1002 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
1003 	    || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
1004 		perr("could not write LOST.DIR");
1005 		return FSFATAL;
1006 	}
1007 	return FSDIRMOD;
1008 }
1009 
1010 void
1011 finishlf(void)
1012 {
1013 	if (lfbuf)
1014 		free(lfbuf);
1015 	lfbuf = NULL;
1016 }
1017