xref: /freebsd/sbin/fsck_msdosfs/dir.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*
2  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
3  * Copyright (c) 1995 Martin Husemann
4  * Some structure declaration borrowed from Paul Popelka
5  * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Martin Husemann
18  *	and Wolfgang Solfrank.
19  * 4. 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 AUTHORS ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __RCSID("$NetBSD: dir.c,v 1.14 1998/08/25 19:18:15 ross Exp $");
39 static const char rcsid[] =
40   "$FreeBSD$";
41 #endif /* not lint */
42 
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <ctype.h>
47 #include <stdio.h>
48 #include <unistd.h>
49 #include <time.h>
50 
51 #include <sys/param.h>
52 
53 #include "ext.h"
54 #include "fsutil.h"
55 
56 #define	SLOT_EMPTY	0x00		/* slot has never been used */
57 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
58 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
59 
60 #define	ATTR_NORMAL	0x00		/* normal file */
61 #define	ATTR_READONLY	0x01		/* file is readonly */
62 #define	ATTR_HIDDEN	0x02		/* file is hidden */
63 #define	ATTR_SYSTEM	0x04		/* file is a system file */
64 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
65 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
66 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
67 
68 #define	ATTR_WIN95	0x0f		/* long name record */
69 
70 /*
71  * This is the format of the contents of the deTime field in the direntry
72  * structure.
73  * We don't use bitfields because we don't know how compilers for
74  * arbitrary machines will lay them out.
75  */
76 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
77 #define DT_2SECONDS_SHIFT	0
78 #define DT_MINUTES_MASK		0x7E0	/* minutes */
79 #define DT_MINUTES_SHIFT	5
80 #define DT_HOURS_MASK		0xF800	/* hours */
81 #define DT_HOURS_SHIFT		11
82 
83 /*
84  * This is the format of the contents of the deDate field in the direntry
85  * structure.
86  */
87 #define DD_DAY_MASK		0x1F	/* day of month */
88 #define DD_DAY_SHIFT		0
89 #define DD_MONTH_MASK		0x1E0	/* month */
90 #define DD_MONTH_SHIFT		5
91 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
92 #define DD_YEAR_SHIFT		9
93 
94 
95 /* dir.c */
96 static struct dosDirEntry *newDosDirEntry(void);
97 static void freeDosDirEntry(struct dosDirEntry *);
98 static struct dirTodoNode *newDirTodo(void);
99 static void freeDirTodo(struct dirTodoNode *);
100 static char *fullpath(struct dosDirEntry *);
101 static u_char calcShortSum(u_char *);
102 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
103     cl_t, int, int);
104 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
105     u_char *, cl_t, cl_t, cl_t, char *, int);
106 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
107     struct dosDirEntry *);
108 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
109     struct dosDirEntry *);
110 
111 /*
112  * Manage free dosDirEntry structures.
113  */
114 static struct dosDirEntry *freede;
115 
116 static struct dosDirEntry *
117 newDosDirEntry(void)
118 {
119 	struct dosDirEntry *de;
120 
121 	if (!(de = freede)) {
122 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
123 			return 0;
124 	} else
125 		freede = de->next;
126 	return de;
127 }
128 
129 static void
130 freeDosDirEntry(struct dosDirEntry *de)
131 {
132 	de->next = freede;
133 	freede = de;
134 }
135 
136 /*
137  * The same for dirTodoNode structures.
138  */
139 static struct dirTodoNode *freedt;
140 
141 static struct dirTodoNode *
142 newDirTodo(void)
143 {
144 	struct dirTodoNode *dt;
145 
146 	if (!(dt = freedt)) {
147 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
148 			return 0;
149 	} else
150 		freedt = dt->next;
151 	return dt;
152 }
153 
154 static void
155 freeDirTodo(struct dirTodoNode *dt)
156 {
157 	dt->next = freedt;
158 	freedt = dt;
159 }
160 
161 /*
162  * The stack of unread directories
163  */
164 struct dirTodoNode *pendingDirectories = NULL;
165 
166 /*
167  * Return the full pathname for a directory entry.
168  */
169 static char *
170 fullpath(struct dosDirEntry *dir)
171 {
172 	static char namebuf[MAXPATHLEN + 1];
173 	char *cp, *np;
174 	int nl;
175 
176 	cp = namebuf + sizeof namebuf - 1;
177 	*cp = '\0';
178 	do {
179 		np = dir->lname[0] ? dir->lname : dir->name;
180 		nl = strlen(np);
181 		if ((cp -= nl) <= namebuf + 1)
182 			break;
183 		memcpy(cp, np, nl);
184 		*--cp = '/';
185 	} while ((dir = dir->parent) != NULL);
186 	if (dir)
187 		*--cp = '?';
188 	else
189 		cp++;
190 	return cp;
191 }
192 
193 /*
194  * Calculate a checksum over an 8.3 alias name
195  */
196 static u_char
197 calcShortSum(u_char *p)
198 {
199 	u_char sum = 0;
200 	int i;
201 
202 	for (i = 0; i < 11; i++) {
203 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
204 		sum += p[i];
205 	}
206 
207 	return sum;
208 }
209 
210 /*
211  * Global variables temporarily used during a directory scan
212  */
213 static char longName[DOSLONGNAMELEN] = "";
214 static u_char *buffer = NULL;
215 static u_char *delbuf = NULL;
216 
217 struct dosDirEntry *rootDir;
218 static struct dosDirEntry *lostDir;
219 
220 /*
221  * Init internal state for a new directory scan.
222  */
223 int
224 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
225 {
226 	int b1, b2;
227 	cl_t cl;
228 	int ret = FSOK;
229 
230 	b1 = boot->RootDirEnts * 32;
231 	b2 = boot->SecPerClust * boot->BytesPerSec;
232 
233 	if (!(buffer = malloc(b1 > b2 ? b1 : b2))
234 	    || !(delbuf = malloc(b2))
235 	    || !(rootDir = newDosDirEntry())) {
236 		perror("No space for directory");
237 		return FSFATAL;
238 	}
239 	memset(rootDir, 0, sizeof *rootDir);
240 	if (boot->flags & FAT32) {
241 		if (boot->RootCl < CLUST_FIRST || boot->RootCl >= boot->NumClusters) {
242 			pfatal("Root directory starts with cluster out of range(%u)",
243 			       boot->RootCl);
244 			return FSFATAL;
245 		}
246 		cl = fat[boot->RootCl].next;
247 		if (cl < CLUST_FIRST
248 		    || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
249 		    || fat[boot->RootCl].head != boot->RootCl) {
250 			if (cl == CLUST_FREE)
251 				pwarn("Root directory starts with free cluster\n");
252 			else if (cl >= CLUST_RSRVD)
253 				pwarn("Root directory starts with cluster marked %s\n",
254 				      rsrvdcltype(cl));
255 			else {
256 				pfatal("Root directory doesn't start a cluster chain");
257 				return FSFATAL;
258 			}
259 			if (ask(1, "Fix")) {
260 				fat[boot->RootCl].next = CLUST_FREE;
261 				ret = FSFATMOD;
262 			} else
263 				ret = FSFATAL;
264 		}
265 
266 		fat[boot->RootCl].flags |= FAT_USED;
267 		rootDir->head = boot->RootCl;
268 	}
269 
270 	return ret;
271 }
272 
273 /*
274  * Cleanup after a directory scan
275  */
276 void
277 finishDosDirSection(void)
278 {
279 	struct dirTodoNode *p, *np;
280 	struct dosDirEntry *d, *nd;
281 
282 	for (p = pendingDirectories; p; p = np) {
283 		np = p->next;
284 		freeDirTodo(p);
285 	}
286 	pendingDirectories = 0;
287 	for (d = rootDir; d; d = nd) {
288 		if ((nd = d->child) != NULL) {
289 			d->child = 0;
290 			continue;
291 		}
292 		if (!(nd = d->next))
293 			nd = d->parent;
294 		freeDosDirEntry(d);
295 	}
296 	rootDir = lostDir = NULL;
297 	free(buffer);
298 	free(delbuf);
299 	buffer = NULL;
300 	delbuf = NULL;
301 }
302 
303 /*
304  * Delete directory entries between startcl, startoff and endcl, endoff.
305  */
306 static int
307 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
308     int startoff, cl_t endcl, int endoff, int notlast)
309 {
310 	u_char *s, *e;
311 	off_t off;
312 	int clsz = boot->SecPerClust * boot->BytesPerSec;
313 
314 	s = delbuf + startoff;
315 	e = delbuf + clsz;
316 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
317 		if (startcl == endcl) {
318 			if (notlast)
319 				break;
320 			e = delbuf + endoff;
321 		}
322 		off = startcl * boot->SecPerClust + boot->ClusterOffset;
323 		off *= boot->BytesPerSec;
324 		if (lseek(f, off, SEEK_SET) != off
325 		    || read(f, delbuf, clsz) != clsz) {
326 			perror("Unable to read directory");
327 			return FSFATAL;
328 		}
329 		while (s < e) {
330 			*s = SLOT_DELETED;
331 			s += 32;
332 		}
333 		if (lseek(f, off, SEEK_SET) != off
334 		    || write(f, delbuf, clsz) != clsz) {
335 			perror("Unable to write directory");
336 			return FSFATAL;
337 		}
338 		if (startcl == endcl)
339 			break;
340 		startcl = fat[startcl].next;
341 		s = delbuf;
342 	}
343 	return FSOK;
344 }
345 
346 static int
347 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
348     u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
349 {
350 	switch (type) {
351 	case 0:
352 		pwarn("Invalid long filename entry for %s\n", path);
353 		break;
354 	case 1:
355 		pwarn("Invalid long filename entry at end of directory %s\n", path);
356 		break;
357 	case 2:
358 		pwarn("Invalid long filename entry for volume label\n");
359 		break;
360 	}
361 	if (ask(0, "Remove")) {
362 		if (startcl != curcl) {
363 			if (delete(f, boot, fat,
364 				   startcl, start - buffer,
365 				   endcl, end - buffer,
366 				   endcl == curcl) == FSFATAL)
367 				return FSFATAL;
368 			start = buffer;
369 		}
370 		if (endcl == curcl)
371 			for (; start < end; start += 32)
372 				*start = SLOT_DELETED;
373 		return FSDIRMOD;
374 	}
375 	return FSERROR;
376 }
377 
378 /*
379  * Check an in-memory file entry
380  */
381 static int
382 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
383     struct dosDirEntry *dir)
384 {
385 	/*
386 	 * Check size on ordinary files
387 	 */
388 	int32_t physicalSize;
389 
390 	if (dir->head == CLUST_FREE)
391 		physicalSize = 0;
392 	else {
393 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
394 			return FSERROR;
395 		physicalSize = fat[dir->head].length * boot->ClusterSize;
396 	}
397 	if (physicalSize < dir->size) {
398 		pwarn("size of %s is %u, should at most be %u\n",
399 		      fullpath(dir), dir->size, physicalSize);
400 		if (ask(1, "Truncate")) {
401 			dir->size = physicalSize;
402 			p[28] = (u_char)physicalSize;
403 			p[29] = (u_char)(physicalSize >> 8);
404 			p[30] = (u_char)(physicalSize >> 16);
405 			p[31] = (u_char)(physicalSize >> 24);
406 			return FSDIRMOD;
407 		} else
408 			return FSERROR;
409 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
410 		pwarn("%s has too many clusters allocated\n",
411 		      fullpath(dir));
412 		if (ask(1, "Drop superfluous clusters")) {
413 			cl_t cl;
414 			u_int32_t sz = 0;
415 
416 			for (cl = dir->head; (sz += boot->ClusterSize) < dir->size;)
417 				cl = fat[cl].next;
418 			clearchain(boot, fat, fat[cl].next);
419 			fat[cl].next = CLUST_EOF;
420 			return FSFATMOD;
421 		} else
422 			return FSERROR;
423 	}
424 	return FSOK;
425 }
426 
427 /*
428  * Read a directory and
429  *   - resolve long name records
430  *   - enter file and directory records into the parent's list
431  *   - push directories onto the todo-stack
432  */
433 static int
434 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
435     struct dosDirEntry *dir)
436 {
437 	struct dosDirEntry dirent, *d;
438 	u_char *p, *vallfn, *invlfn, *empty;
439 	off_t off;
440 	int i, j, k, last;
441 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
442 	char *t;
443 	u_int lidx = 0;
444 	int shortSum;
445 	int mod = FSOK;
446 #define	THISMOD	0x8000			/* Only used within this routine */
447 
448 	cl = dir->head;
449 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
450 		/*
451 		 * Already handled somewhere else.
452 		 */
453 		return FSOK;
454 	}
455 	shortSum = -1;
456 	vallfn = invlfn = empty = NULL;
457 	do {
458 		if (!(boot->flags & FAT32) && !dir->parent) {
459 			last = boot->RootDirEnts * 32;
460 			off = boot->ResSectors + boot->FATs * boot->FATsecs;
461 		} else {
462 			last = boot->SecPerClust * boot->BytesPerSec;
463 			off = cl * boot->SecPerClust + boot->ClusterOffset;
464 		}
465 
466 		off *= boot->BytesPerSec;
467 		if (lseek(f, off, SEEK_SET) != off
468 		    || read(f, buffer, last) != last) {
469 			perror("Unable to read directory");
470 			return FSFATAL;
471 		}
472 		last /= 32;
473 		/*
474 		 * Check `.' and `..' entries here?			XXX
475 		 */
476 		for (p = buffer, i = 0; i < last; i++, p += 32) {
477 			if (dir->fsckflags & DIREMPWARN) {
478 				*p = SLOT_EMPTY;
479 				continue;
480 			}
481 
482 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
483 				if (*p == SLOT_EMPTY) {
484 					dir->fsckflags |= DIREMPTY;
485 					empty = p;
486 					empcl = cl;
487 				}
488 				continue;
489 			}
490 
491 			if (dir->fsckflags & DIREMPTY) {
492 				if (!(dir->fsckflags & DIREMPWARN)) {
493 					pwarn("%s has entries after end of directory\n",
494 					      fullpath(dir));
495 					if (ask(1, "Extend")) {
496 						u_char *q;
497 
498 						dir->fsckflags &= ~DIREMPTY;
499 						if (delete(f, boot, fat,
500 							   empcl, empty - buffer,
501 							   cl, p - buffer, 1) == FSFATAL)
502 							return FSFATAL;
503 						q = empcl == cl ? empty : buffer;
504 						for (; q < p; q += 32)
505 							*q = SLOT_DELETED;
506 						mod |= THISMOD|FSDIRMOD;
507 					} else if (ask(0, "Truncate"))
508 						dir->fsckflags |= DIREMPWARN;
509 				}
510 				if (dir->fsckflags & DIREMPWARN) {
511 					*p = SLOT_DELETED;
512 					mod |= THISMOD|FSDIRMOD;
513 					continue;
514 				} else if (dir->fsckflags & DIREMPTY)
515 					mod |= FSERROR;
516 				empty = NULL;
517 			}
518 
519 			if (p[11] == ATTR_WIN95) {
520 				if (*p & LRFIRST) {
521 					if (shortSum != -1) {
522 						if (!invlfn) {
523 							invlfn = vallfn;
524 							invcl = valcl;
525 						}
526 					}
527 					memset(longName, 0, sizeof longName);
528 					shortSum = p[13];
529 					vallfn = p;
530 					valcl = cl;
531 				} else if (shortSum != p[13]
532 					   || lidx != (*p & LRNOMASK)) {
533 					if (!invlfn) {
534 						invlfn = vallfn;
535 						invcl = valcl;
536 					}
537 					if (!invlfn) {
538 						invlfn = p;
539 						invcl = cl;
540 					}
541 					vallfn = NULL;
542 				}
543 				lidx = *p & LRNOMASK;
544 				t = longName + --lidx * 13;
545 				for (k = 1; k < 11 && t < longName + sizeof(longName); k += 2) {
546 					if (!p[k] && !p[k + 1])
547 						break;
548 					*t++ = p[k];
549 					/*
550 					 * Warn about those unusable chars in msdosfs here?	XXX
551 					 */
552 					if (p[k + 1])
553 						t[-1] = '?';
554 				}
555 				if (k >= 11)
556 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
557 						if (!p[k] && !p[k + 1])
558 							break;
559 						*t++ = p[k];
560 						if (p[k + 1])
561 							t[-1] = '?';
562 					}
563 				if (k >= 26)
564 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
565 						if (!p[k] && !p[k + 1])
566 							break;
567 						*t++ = p[k];
568 						if (p[k + 1])
569 							t[-1] = '?';
570 					}
571 				if (t >= longName + sizeof(longName)) {
572 					pwarn("long filename too long\n");
573 					if (!invlfn) {
574 						invlfn = vallfn;
575 						invcl = valcl;
576 					}
577 					vallfn = NULL;
578 				}
579 				if (p[26] | (p[27] << 8)) {
580 					pwarn("long filename record cluster start != 0\n");
581 					if (!invlfn) {
582 						invlfn = vallfn;
583 						invcl = cl;
584 					}
585 					vallfn = NULL;
586 				}
587 				continue;	/* long records don't carry further
588 						 * information */
589 			}
590 
591 			/*
592 			 * This is a standard msdosfs directory entry.
593 			 */
594 			memset(&dirent, 0, sizeof dirent);
595 
596 			/*
597 			 * it's a short name record, but we need to know
598 			 * more, so get the flags first.
599 			 */
600 			dirent.flags = p[11];
601 
602 			/*
603 			 * Translate from 850 to ISO here		XXX
604 			 */
605 			for (j = 0; j < 8; j++)
606 				dirent.name[j] = p[j];
607 			dirent.name[8] = '\0';
608 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
609 				dirent.name[k] = '\0';
610 			if (dirent.name[k] != '\0')
611 				k++;
612 			if (dirent.name[0] == SLOT_E5)
613 				dirent.name[0] = 0xe5;
614 
615 			if (dirent.flags & ATTR_VOLUME) {
616 				if (vallfn || invlfn) {
617 					mod |= removede(f, boot, fat,
618 							invlfn ? invlfn : vallfn, p,
619 							invlfn ? invcl : valcl, -1, 0,
620 							fullpath(dir), 2);
621 					vallfn = NULL;
622 					invlfn = NULL;
623 				}
624 				continue;
625 			}
626 
627 			if (p[8] != ' ')
628 				dirent.name[k++] = '.';
629 			for (j = 0; j < 3; j++)
630 				dirent.name[k++] = p[j+8];
631 			dirent.name[k] = '\0';
632 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
633 				dirent.name[k] = '\0';
634 
635 			if (vallfn && shortSum != calcShortSum(p)) {
636 				if (!invlfn) {
637 					invlfn = vallfn;
638 					invcl = valcl;
639 				}
640 				vallfn = NULL;
641 			}
642 			dirent.head = p[26] | (p[27] << 8);
643 			if (boot->ClustMask == CLUST32_MASK)
644 				dirent.head |= (p[20] << 16) | (p[21] << 24);
645 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
646 			if (vallfn) {
647 				strcpy(dirent.lname, longName);
648 				longName[0] = '\0';
649 				shortSum = -1;
650 			}
651 
652 			dirent.parent = dir;
653 			dirent.next = dir->child;
654 
655 			if (invlfn) {
656 				mod |= k = removede(f, boot, fat,
657 						    invlfn, vallfn ? vallfn : p,
658 						    invcl, vallfn ? valcl : cl, cl,
659 						    fullpath(&dirent), 0);
660 				if (mod & FSFATAL)
661 					return FSFATAL;
662 				if (vallfn
663 				    ? (valcl == cl && vallfn != buffer)
664 				    : p != buffer)
665 					if (k & FSDIRMOD)
666 						mod |= THISMOD;
667 			}
668 
669 			vallfn = NULL; /* not used any longer */
670 			invlfn = NULL;
671 
672 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
673 				if (dirent.head != 0) {
674 					pwarn("%s has clusters, but size 0\n",
675 					      fullpath(&dirent));
676 					if (ask(1, "Drop allocated clusters")) {
677 						p[26] = p[27] = 0;
678 						if (boot->ClustMask == CLUST32_MASK)
679 							p[20] = p[21] = 0;
680 						clearchain(boot, fat, dirent.head);
681 						dirent.head = 0;
682 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
683 					} else
684 						mod |= FSERROR;
685 				}
686 			} else if (dirent.head == 0
687 				   && !strcmp(dirent.name, "..")
688 				   && dir->parent			/* XXX */
689 				   && !dir->parent->parent) {
690 				/*
691 				 *  Do nothing, the parent is the root
692 				 */
693 			} else if (dirent.head < CLUST_FIRST
694 				   || dirent.head >= boot->NumClusters
695 				   || fat[dirent.head].next == CLUST_FREE
696 				   || (fat[dirent.head].next >= CLUST_RSRVD
697 				       && fat[dirent.head].next < CLUST_EOFS)
698 				   || fat[dirent.head].head != dirent.head) {
699 				if (dirent.head == 0)
700 					pwarn("%s has no clusters\n",
701 					      fullpath(&dirent));
702 				else if (dirent.head < CLUST_FIRST
703 					 || dirent.head >= boot->NumClusters)
704 					pwarn("%s starts with cluster out of range(%u)\n",
705 					      fullpath(&dirent),
706 					      dirent.head);
707 				else if (fat[dirent.head].next == CLUST_FREE)
708 					pwarn("%s starts with free cluster\n",
709 					      fullpath(&dirent));
710 				else if (fat[dirent.head].next >= CLUST_RSRVD)
711 					pwarn("%s starts with cluster marked %s\n",
712 					      fullpath(&dirent),
713 					      rsrvdcltype(fat[dirent.head].next));
714 				else
715 					pwarn("%s doesn't start a cluster chain\n",
716 					      fullpath(&dirent));
717 				if (dirent.flags & ATTR_DIRECTORY) {
718 					if (ask(0, "Remove")) {
719 						*p = SLOT_DELETED;
720 						mod |= THISMOD|FSDIRMOD;
721 					} else
722 						mod |= FSERROR;
723 					continue;
724 				} else {
725 					if (ask(1, "Truncate")) {
726 						p[28] = p[29] = p[30] = p[31] = 0;
727 						p[26] = p[27] = 0;
728 						if (boot->ClustMask == CLUST32_MASK)
729 							p[20] = p[21] = 0;
730 						dirent.size = 0;
731 						mod |= THISMOD|FSDIRMOD;
732 					} else
733 						mod |= FSERROR;
734 				}
735 			}
736 
737 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
738 				fat[dirent.head].flags |= FAT_USED;
739 
740 			if (dirent.flags & ATTR_DIRECTORY) {
741 				/*
742 				 * gather more info for directories
743 				 */
744 				struct dirTodoNode *n;
745 
746 				if (dirent.size) {
747 					pwarn("Directory %s has size != 0\n",
748 					      fullpath(&dirent));
749 					if (ask(1, "Correct")) {
750 						p[28] = p[29] = p[30] = p[31] = 0;
751 						dirent.size = 0;
752 						mod |= THISMOD|FSDIRMOD;
753 					} else
754 						mod |= FSERROR;
755 				}
756 				/*
757 				 * handle `.' and `..' specially
758 				 */
759 				if (strcmp(dirent.name, ".") == 0) {
760 					if (dirent.head != dir->head) {
761 						pwarn("`.' entry in %s has incorrect start cluster\n",
762 						      fullpath(dir));
763 						if (ask(1, "Correct")) {
764 							dirent.head = dir->head;
765 							p[26] = (u_char)dirent.head;
766 							p[27] = (u_char)(dirent.head >> 8);
767 							if (boot->ClustMask == CLUST32_MASK) {
768 								p[20] = (u_char)(dirent.head >> 16);
769 								p[21] = (u_char)(dirent.head >> 24);
770 							}
771 							mod |= THISMOD|FSDIRMOD;
772 						} else
773 							mod |= FSERROR;
774 					}
775 					continue;
776 				}
777 				if (strcmp(dirent.name, "..") == 0) {
778 					if (dir->parent) {		/* XXX */
779 						if (!dir->parent->parent) {
780 							if (dirent.head) {
781 								pwarn("`..' entry in %s has non-zero start cluster\n",
782 								      fullpath(dir));
783 								if (ask(1, "Correct")) {
784 									dirent.head = 0;
785 									p[26] = p[27] = 0;
786 									if (boot->ClustMask == CLUST32_MASK)
787 										p[20] = p[21] = 0;
788 									mod |= THISMOD|FSDIRMOD;
789 								} else
790 									mod |= FSERROR;
791 							}
792 						} else if (dirent.head != dir->parent->head) {
793 							pwarn("`..' entry in %s has incorrect start cluster\n",
794 							      fullpath(dir));
795 							if (ask(1, "Correct")) {
796 								dirent.head = dir->parent->head;
797 								p[26] = (u_char)dirent.head;
798 								p[27] = (u_char)(dirent.head >> 8);
799 								if (boot->ClustMask == CLUST32_MASK) {
800 									p[20] = (u_char)(dirent.head >> 16);
801 									p[21] = (u_char)(dirent.head >> 24);
802 								}
803 								mod |= THISMOD|FSDIRMOD;
804 							} else
805 								mod |= FSERROR;
806 						}
807 					}
808 					continue;
809 				}
810 
811 				/* create directory tree node */
812 				if (!(d = newDosDirEntry())) {
813 					perror("No space for directory");
814 					return FSFATAL;
815 				}
816 				memcpy(d, &dirent, sizeof(struct dosDirEntry));
817 				/* link it into the tree */
818 				dir->child = d;
819 
820 				/* Enter this directory into the todo list */
821 				if (!(n = newDirTodo())) {
822 					perror("No space for todo list");
823 					return FSFATAL;
824 				}
825 				n->next = pendingDirectories;
826 				n->dir = d;
827 				pendingDirectories = n;
828 			} else {
829 				mod |= k = checksize(boot, fat, p, &dirent);
830 				if (k & FSDIRMOD)
831 					mod |= THISMOD;
832 			}
833 			boot->NumFiles++;
834 		}
835 		if (mod & THISMOD) {
836 			last *= 32;
837 			if (lseek(f, off, SEEK_SET) != off
838 			    || write(f, buffer, last) != last) {
839 				perror("Unable to write directory");
840 				return FSFATAL;
841 			}
842 			mod &= ~THISMOD;
843 		}
844 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
845 	if (invlfn || vallfn)
846 		mod |= removede(f, boot, fat,
847 				invlfn ? invlfn : vallfn, p,
848 				invlfn ? invcl : valcl, -1, 0,
849 				fullpath(dir), 1);
850 	return mod & ~THISMOD;
851 }
852 
853 int
854 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
855 {
856 	int mod;
857 
858 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
859 	if (mod & FSFATAL)
860 		return FSFATAL;
861 
862 	/*
863 	 * process the directory todo list
864 	 */
865 	while (pendingDirectories) {
866 		struct dosDirEntry *dir = pendingDirectories->dir;
867 		struct dirTodoNode *n = pendingDirectories->next;
868 
869 		/*
870 		 * remove TODO entry now, the list might change during
871 		 * directory reads
872 		 */
873 		freeDirTodo(pendingDirectories);
874 		pendingDirectories = n;
875 
876 		/*
877 		 * handle subdirectory
878 		 */
879 		mod |= readDosDirSection(dosfs, boot, fat, dir);
880 		if (mod & FSFATAL)
881 			return FSFATAL;
882 	}
883 
884 	return mod;
885 }
886 
887 /*
888  * Try to reconnect a FAT chain into dir
889  */
890 static u_char *lfbuf;
891 static cl_t lfcl;
892 static off_t lfoff;
893 
894 int
895 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
896 {
897 	struct dosDirEntry d;
898 	u_char *p;
899 
900 	if (!ask(1, "Reconnect"))
901 		return FSERROR;
902 
903 	if (!lostDir) {
904 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
905 			if (!strcmp(lostDir->name, LOSTDIR))
906 				break;
907 		}
908 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
909 			pwarn("No %s directory\n", LOSTDIR);
910 			return FSERROR;
911 		}
912 	}
913 	if (!lfbuf) {
914 		lfbuf = malloc(boot->ClusterSize);
915 		if (!lfbuf) {
916 			perror("No space for buffer");
917 			return FSFATAL;
918 		}
919 		p = NULL;
920 	} else
921 		p = lfbuf;
922 	while (1) {
923 		if (p)
924 			for (; p < lfbuf + boot->ClusterSize; p += 32)
925 				if (*p == SLOT_EMPTY
926 				    || *p == SLOT_DELETED)
927 					break;
928 		if (p && p < lfbuf + boot->ClusterSize)
929 			break;
930 		lfcl = p ? fat[lfcl].next : lostDir->head;
931 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
932 			/* Extend LOSTDIR?				XXX */
933 			pwarn("No space in %s\n", LOSTDIR);
934 			return FSERROR;
935 		}
936 		lfoff = lfcl * boot->ClusterSize
937 		    + boot->ClusterOffset * boot->BytesPerSec;
938 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
939 		    || read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
940 			perror("could not read LOST.DIR");
941 			return FSFATAL;
942 		}
943 		p = lfbuf;
944 	}
945 
946 	boot->NumFiles++;
947 	/* Ensure uniqueness of entry here!				XXX */
948 	memset(&d, 0, sizeof d);
949 	(void)snprintf(d.name, sizeof(d.name), "%u", head);
950 	d.flags = 0;
951 	d.head = head;
952 	d.size = fat[head].length * boot->ClusterSize;
953 
954 	memset(p, 0, 32);
955 	memset(p, ' ', 11);
956 	memcpy(p, d.name, strlen(d.name));
957 	p[26] = (u_char)d.head;
958 	p[27] = (u_char)(d.head >> 8);
959 	if (boot->ClustMask == CLUST32_MASK) {
960 		p[20] = (u_char)(d.head >> 16);
961 		p[21] = (u_char)(d.head >> 24);
962 	}
963 	p[28] = (u_char)d.size;
964 	p[29] = (u_char)(d.size >> 8);
965 	p[30] = (u_char)(d.size >> 16);
966 	p[31] = (u_char)(d.size >> 24);
967 	fat[head].flags |= FAT_USED;
968 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
969 	    || write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
970 		perror("could not write LOST.DIR");
971 		return FSFATAL;
972 	}
973 	return FSDIRMOD;
974 }
975 
976 void
977 finishlf(void)
978 {
979 	if (lfbuf)
980 		free(lfbuf);
981 	lfbuf = NULL;
982 }
983