xref: /dragonfly/sbin/fsck_msdosfs/dir.c (revision 1de703da)
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  * $NetBSD: dir.c,v 1.14 1998/08/25 19:18:15 ross Exp $
35  * $FreeBSD: src/sbin/fsck_msdosfs/dir.c,v 1.1.2.1 2001/08/01 05:47:55 obrien Exp $
36  * $DragonFly: src/sbin/fsck_msdosfs/dir.c,v 1.2 2003/06/17 04:27:32 dillon Exp $
37  */
38 
39 
40 #include <sys/cdefs.h>
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <ctype.h>
46 #include <stdio.h>
47 #include <unistd.h>
48 #include <time.h>
49 
50 #include <sys/param.h>
51 
52 #include "ext.h"
53 #include "fsutil.h"
54 
55 #define	SLOT_EMPTY	0x00		/* slot has never been used */
56 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
57 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
58 
59 #define	ATTR_NORMAL	0x00		/* normal file */
60 #define	ATTR_READONLY	0x01		/* file is readonly */
61 #define	ATTR_HIDDEN	0x02		/* file is hidden */
62 #define	ATTR_SYSTEM	0x04		/* file is a system file */
63 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
64 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
65 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
66 
67 #define	ATTR_WIN95	0x0f		/* long name record */
68 
69 /*
70  * This is the format of the contents of the deTime field in the direntry
71  * structure.
72  * We don't use bitfields because we don't know how compilers for
73  * arbitrary machines will lay them out.
74  */
75 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
76 #define DT_2SECONDS_SHIFT	0
77 #define DT_MINUTES_MASK		0x7E0	/* minutes */
78 #define DT_MINUTES_SHIFT	5
79 #define DT_HOURS_MASK		0xF800	/* hours */
80 #define DT_HOURS_SHIFT		11
81 
82 /*
83  * This is the format of the contents of the deDate field in the direntry
84  * structure.
85  */
86 #define DD_DAY_MASK		0x1F	/* day of month */
87 #define DD_DAY_SHIFT		0
88 #define DD_MONTH_MASK		0x1E0	/* month */
89 #define DD_MONTH_SHIFT		5
90 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
91 #define DD_YEAR_SHIFT		9
92 
93 
94 /* dir.c */
95 static struct dosDirEntry *newDosDirEntry __P((void));
96 static void freeDosDirEntry __P((struct dosDirEntry *));
97 static struct dirTodoNode *newDirTodo __P((void));
98 static void freeDirTodo __P((struct dirTodoNode *));
99 static char *fullpath __P((struct dosDirEntry *));
100 static u_char calcShortSum __P((u_char *));
101 static int delete __P((int, struct bootblock *, struct fatEntry *, cl_t, int,
102     cl_t, int, int));
103 static int removede __P((int, struct bootblock *, struct fatEntry *, u_char *,
104     u_char *, cl_t, cl_t, cl_t, char *, int));
105 static int checksize __P((struct bootblock *, struct fatEntry *, u_char *,
106     struct dosDirEntry *));
107 static int readDosDirSection __P((int, struct bootblock *, struct fatEntry *,
108     struct dosDirEntry *));
109 
110 /*
111  * Manage free dosDirEntry structures.
112  */
113 static struct dosDirEntry *freede;
114 
115 static struct dosDirEntry *
116 newDosDirEntry()
117 {
118 	struct dosDirEntry *de;
119 
120 	if (!(de = freede)) {
121 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
122 			return 0;
123 	} else
124 		freede = de->next;
125 	return de;
126 }
127 
128 static void
129 freeDosDirEntry(de)
130 	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()
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(dt)
156 	struct dirTodoNode *dt;
157 {
158 	dt->next = freedt;
159 	freedt = dt;
160 }
161 
162 /*
163  * The stack of unread directories
164  */
165 struct dirTodoNode *pendingDirectories = NULL;
166 
167 /*
168  * Return the full pathname for a directory entry.
169  */
170 static char *
171 fullpath(dir)
172 	struct dosDirEntry *dir;
173 {
174 	static char namebuf[MAXPATHLEN + 1];
175 	char *cp, *np;
176 	int nl;
177 
178 	cp = namebuf + sizeof namebuf - 1;
179 	*cp = '\0';
180 	do {
181 		np = dir->lname[0] ? dir->lname : dir->name;
182 		nl = strlen(np);
183 		if ((cp -= nl) <= namebuf + 1)
184 			break;
185 		memcpy(cp, np, nl);
186 		*--cp = '/';
187 	} while ((dir = dir->parent) != NULL);
188 	if (dir)
189 		*--cp = '?';
190 	else
191 		cp++;
192 	return cp;
193 }
194 
195 /*
196  * Calculate a checksum over an 8.3 alias name
197  */
198 static u_char
199 calcShortSum(p)
200 	u_char *p;
201 {
202 	u_char sum = 0;
203 	int i;
204 
205 	for (i = 0; i < 11; i++) {
206 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
207 		sum += p[i];
208 	}
209 
210 	return sum;
211 }
212 
213 /*
214  * Global variables temporarily used during a directory scan
215  */
216 static char longName[DOSLONGNAMELEN] = "";
217 static u_char *buffer = NULL;
218 static u_char *delbuf = NULL;
219 
220 struct dosDirEntry *rootDir;
221 static struct dosDirEntry *lostDir;
222 
223 /*
224  * Init internal state for a new directory scan.
225  */
226 int
227 resetDosDirSection(boot, fat)
228 	struct bootblock *boot;
229 	struct fatEntry *fat;
230 {
231 	int b1, b2;
232 	cl_t cl;
233 	int ret = FSOK;
234 
235 	b1 = boot->RootDirEnts * 32;
236 	b2 = boot->SecPerClust * boot->BytesPerSec;
237 
238 	if (!(buffer = malloc(b1 > b2 ? b1 : b2))
239 	    || !(delbuf = malloc(b2))
240 	    || !(rootDir = newDosDirEntry())) {
241 		perror("No space for directory");
242 		return FSFATAL;
243 	}
244 	memset(rootDir, 0, sizeof *rootDir);
245 	if (boot->flags & FAT32) {
246 		if (boot->RootCl < CLUST_FIRST || boot->RootCl >= boot->NumClusters) {
247 			pfatal("Root directory starts with cluster out of range(%u)",
248 			       boot->RootCl);
249 			return FSFATAL;
250 		}
251 		cl = fat[boot->RootCl].next;
252 		if (cl < CLUST_FIRST
253 		    || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
254 		    || fat[boot->RootCl].head != boot->RootCl) {
255 			if (cl == CLUST_FREE)
256 				pwarn("Root directory starts with free cluster\n");
257 			else if (cl >= CLUST_RSRVD)
258 				pwarn("Root directory starts with cluster marked %s\n",
259 				      rsrvdcltype(cl));
260 			else {
261 				pfatal("Root directory doesn't start a cluster chain");
262 				return FSFATAL;
263 			}
264 			if (ask(1, "Fix")) {
265 				fat[boot->RootCl].next = CLUST_FREE;
266 				ret = FSFATMOD;
267 			} else
268 				ret = FSFATAL;
269 		}
270 
271 		fat[boot->RootCl].flags |= FAT_USED;
272 		rootDir->head = boot->RootCl;
273 	}
274 
275 	return ret;
276 }
277 
278 /*
279  * Cleanup after a directory scan
280  */
281 void
282 finishDosDirSection()
283 {
284 	struct dirTodoNode *p, *np;
285 	struct dosDirEntry *d, *nd;
286 
287 	for (p = pendingDirectories; p; p = np) {
288 		np = p->next;
289 		freeDirTodo(p);
290 	}
291 	pendingDirectories = 0;
292 	for (d = rootDir; d; d = nd) {
293 		if ((nd = d->child) != NULL) {
294 			d->child = 0;
295 			continue;
296 		}
297 		if (!(nd = d->next))
298 			nd = d->parent;
299 		freeDosDirEntry(d);
300 	}
301 	rootDir = lostDir = NULL;
302 	free(buffer);
303 	free(delbuf);
304 	buffer = NULL;
305 	delbuf = NULL;
306 }
307 
308 /*
309  * Delete directory entries between startcl, startoff and endcl, endoff.
310  */
311 static int
312 delete(f, boot, fat, startcl, startoff, endcl, endoff, notlast)
313 	int f;
314 	struct bootblock *boot;
315 	struct fatEntry *fat;
316 	cl_t startcl;
317 	int startoff;
318 	cl_t endcl;
319 	int endoff;
320 	int notlast;
321 {
322 	u_char *s, *e;
323 	off_t off;
324 	int clsz = boot->SecPerClust * boot->BytesPerSec;
325 
326 	s = delbuf + startoff;
327 	e = delbuf + clsz;
328 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
329 		if (startcl == endcl) {
330 			if (notlast)
331 				break;
332 			e = delbuf + endoff;
333 		}
334 		off = startcl * boot->SecPerClust + boot->ClusterOffset;
335 		off *= boot->BytesPerSec;
336 		if (lseek(f, off, SEEK_SET) != off
337 		    || read(f, delbuf, clsz) != clsz) {
338 			perror("Unable to read directory");
339 			return FSFATAL;
340 		}
341 		while (s < e) {
342 			*s = SLOT_DELETED;
343 			s += 32;
344 		}
345 		if (lseek(f, off, SEEK_SET) != off
346 		    || write(f, delbuf, clsz) != clsz) {
347 			perror("Unable to write directory");
348 			return FSFATAL;
349 		}
350 		if (startcl == endcl)
351 			break;
352 		startcl = fat[startcl].next;
353 		s = delbuf;
354 	}
355 	return FSOK;
356 }
357 
358 static int
359 removede(f, boot, fat, start, end, startcl, endcl, curcl, path, type)
360 	int f;
361 	struct bootblock *boot;
362 	struct fatEntry *fat;
363 	u_char *start;
364 	u_char *end;
365 	cl_t startcl;
366 	cl_t endcl;
367 	cl_t curcl;
368 	char *path;
369 	int type;
370 {
371 	switch (type) {
372 	case 0:
373 		pwarn("Invalid long filename entry for %s\n", path);
374 		break;
375 	case 1:
376 		pwarn("Invalid long filename entry at end of directory %s\n", path);
377 		break;
378 	case 2:
379 		pwarn("Invalid long filename entry for volume label\n");
380 		break;
381 	}
382 	if (ask(0, "Remove")) {
383 		if (startcl != curcl) {
384 			if (delete(f, boot, fat,
385 				   startcl, start - buffer,
386 				   endcl, end - buffer,
387 				   endcl == curcl) == FSFATAL)
388 				return FSFATAL;
389 			start = buffer;
390 		}
391 		if (endcl == curcl)
392 			for (; start < end; start += 32)
393 				*start = SLOT_DELETED;
394 		return FSDIRMOD;
395 	}
396 	return FSERROR;
397 }
398 
399 /*
400  * Check an in-memory file entry
401  */
402 static int
403 checksize(boot, fat, p, dir)
404 	struct bootblock *boot;
405 	struct fatEntry *fat;
406 	u_char *p;
407 	struct dosDirEntry *dir;
408 {
409 	/*
410 	 * Check size on ordinary files
411 	 */
412 	int32_t physicalSize;
413 
414 	if (dir->head == CLUST_FREE)
415 		physicalSize = 0;
416 	else {
417 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
418 			return FSERROR;
419 		physicalSize = fat[dir->head].length * boot->ClusterSize;
420 	}
421 	if (physicalSize < dir->size) {
422 		pwarn("size of %s is %u, should at most be %u\n",
423 		      fullpath(dir), dir->size, physicalSize);
424 		if (ask(1, "Truncate")) {
425 			dir->size = physicalSize;
426 			p[28] = (u_char)physicalSize;
427 			p[29] = (u_char)(physicalSize >> 8);
428 			p[30] = (u_char)(physicalSize >> 16);
429 			p[31] = (u_char)(physicalSize >> 24);
430 			return FSDIRMOD;
431 		} else
432 			return FSERROR;
433 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
434 		pwarn("%s has too many clusters allocated\n",
435 		      fullpath(dir));
436 		if (ask(1, "Drop superfluous clusters")) {
437 			cl_t cl;
438 			u_int32_t sz = 0;
439 
440 			for (cl = dir->head; (sz += boot->ClusterSize) < dir->size;)
441 				cl = fat[cl].next;
442 			clearchain(boot, fat, fat[cl].next);
443 			fat[cl].next = CLUST_EOF;
444 			return FSFATMOD;
445 		} else
446 			return FSERROR;
447 	}
448 	return FSOK;
449 }
450 
451 /*
452  * Read a directory and
453  *   - resolve long name records
454  *   - enter file and directory records into the parent's list
455  *   - push directories onto the todo-stack
456  */
457 static int
458 readDosDirSection(f, boot, fat, dir)
459 	int f;
460 	struct bootblock *boot;
461 	struct fatEntry *fat;
462 	struct dosDirEntry *dir;
463 {
464 	struct dosDirEntry dirent, *d;
465 	u_char *p, *vallfn, *invlfn, *empty;
466 	off_t off;
467 	int i, j, k, last;
468 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
469 	char *t;
470 	u_int lidx = 0;
471 	int shortSum;
472 	int mod = FSOK;
473 #define	THISMOD	0x8000			/* Only used within this routine */
474 
475 	cl = dir->head;
476 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
477 		/*
478 		 * Already handled somewhere else.
479 		 */
480 		return FSOK;
481 	}
482 	shortSum = -1;
483 	vallfn = invlfn = empty = NULL;
484 	do {
485 		if (!(boot->flags & FAT32) && !dir->parent) {
486 			last = boot->RootDirEnts * 32;
487 			off = boot->ResSectors + boot->FATs * boot->FATsecs;
488 		} else {
489 			last = boot->SecPerClust * boot->BytesPerSec;
490 			off = cl * boot->SecPerClust + boot->ClusterOffset;
491 		}
492 
493 		off *= boot->BytesPerSec;
494 		if (lseek(f, off, SEEK_SET) != off
495 		    || read(f, buffer, last) != last) {
496 			perror("Unable to read directory");
497 			return FSFATAL;
498 		}
499 		last /= 32;
500 		/*
501 		 * Check `.' and `..' entries here?			XXX
502 		 */
503 		for (p = buffer, i = 0; i < last; i++, p += 32) {
504 			if (dir->fsckflags & DIREMPWARN) {
505 				*p = SLOT_EMPTY;
506 				continue;
507 			}
508 
509 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
510 				if (*p == SLOT_EMPTY) {
511 					dir->fsckflags |= DIREMPTY;
512 					empty = p;
513 					empcl = cl;
514 				}
515 				continue;
516 			}
517 
518 			if (dir->fsckflags & DIREMPTY) {
519 				if (!(dir->fsckflags & DIREMPWARN)) {
520 					pwarn("%s has entries after end of directory\n",
521 					      fullpath(dir));
522 					if (ask(1, "Extend")) {
523 						u_char *q;
524 
525 						dir->fsckflags &= ~DIREMPTY;
526 						if (delete(f, boot, fat,
527 							   empcl, empty - buffer,
528 							   cl, p - buffer, 1) == FSFATAL)
529 							return FSFATAL;
530 						q = empcl == cl ? empty : buffer;
531 						for (; q < p; q += 32)
532 							*q = SLOT_DELETED;
533 						mod |= THISMOD|FSDIRMOD;
534 					} else if (ask(0, "Truncate"))
535 						dir->fsckflags |= DIREMPWARN;
536 				}
537 				if (dir->fsckflags & DIREMPWARN) {
538 					*p = SLOT_DELETED;
539 					mod |= THISMOD|FSDIRMOD;
540 					continue;
541 				} else if (dir->fsckflags & DIREMPTY)
542 					mod |= FSERROR;
543 				empty = NULL;
544 			}
545 
546 			if (p[11] == ATTR_WIN95) {
547 				if (*p & LRFIRST) {
548 					if (shortSum != -1) {
549 						if (!invlfn) {
550 							invlfn = vallfn;
551 							invcl = valcl;
552 						}
553 					}
554 					memset(longName, 0, sizeof longName);
555 					shortSum = p[13];
556 					vallfn = p;
557 					valcl = cl;
558 				} else if (shortSum != p[13]
559 					   || lidx != (*p & LRNOMASK)) {
560 					if (!invlfn) {
561 						invlfn = vallfn;
562 						invcl = valcl;
563 					}
564 					if (!invlfn) {
565 						invlfn = p;
566 						invcl = cl;
567 					}
568 					vallfn = NULL;
569 				}
570 				lidx = *p & LRNOMASK;
571 				t = longName + --lidx * 13;
572 				for (k = 1; k < 11 && t < longName + sizeof(longName); k += 2) {
573 					if (!p[k] && !p[k + 1])
574 						break;
575 					*t++ = p[k];
576 					/*
577 					 * Warn about those unusable chars in msdosfs here?	XXX
578 					 */
579 					if (p[k + 1])
580 						t[-1] = '?';
581 				}
582 				if (k >= 11)
583 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
584 						if (!p[k] && !p[k + 1])
585 							break;
586 						*t++ = p[k];
587 						if (p[k + 1])
588 							t[-1] = '?';
589 					}
590 				if (k >= 26)
591 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
592 						if (!p[k] && !p[k + 1])
593 							break;
594 						*t++ = p[k];
595 						if (p[k + 1])
596 							t[-1] = '?';
597 					}
598 				if (t >= longName + sizeof(longName)) {
599 					pwarn("long filename too long\n");
600 					if (!invlfn) {
601 						invlfn = vallfn;
602 						invcl = valcl;
603 					}
604 					vallfn = NULL;
605 				}
606 				if (p[26] | (p[27] << 8)) {
607 					pwarn("long filename record cluster start != 0\n");
608 					if (!invlfn) {
609 						invlfn = vallfn;
610 						invcl = cl;
611 					}
612 					vallfn = NULL;
613 				}
614 				continue;	/* long records don't carry further
615 						 * information */
616 			}
617 
618 			/*
619 			 * This is a standard msdosfs directory entry.
620 			 */
621 			memset(&dirent, 0, sizeof dirent);
622 
623 			/*
624 			 * it's a short name record, but we need to know
625 			 * more, so get the flags first.
626 			 */
627 			dirent.flags = p[11];
628 
629 			/*
630 			 * Translate from 850 to ISO here		XXX
631 			 */
632 			for (j = 0; j < 8; j++)
633 				dirent.name[j] = p[j];
634 			dirent.name[8] = '\0';
635 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
636 				dirent.name[k] = '\0';
637 			if (dirent.name[k] != '\0')
638 				k++;
639 			if (dirent.name[0] == SLOT_E5)
640 				dirent.name[0] = 0xe5;
641 
642 			if (dirent.flags & ATTR_VOLUME) {
643 				if (vallfn || invlfn) {
644 					mod |= removede(f, boot, fat,
645 							invlfn ? invlfn : vallfn, p,
646 							invlfn ? invcl : valcl, -1, 0,
647 							fullpath(dir), 2);
648 					vallfn = NULL;
649 					invlfn = NULL;
650 				}
651 				continue;
652 			}
653 
654 			if (p[8] != ' ')
655 				dirent.name[k++] = '.';
656 			for (j = 0; j < 3; j++)
657 				dirent.name[k++] = p[j+8];
658 			dirent.name[k] = '\0';
659 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
660 				dirent.name[k] = '\0';
661 
662 			if (vallfn && shortSum != calcShortSum(p)) {
663 				if (!invlfn) {
664 					invlfn = vallfn;
665 					invcl = valcl;
666 				}
667 				vallfn = NULL;
668 			}
669 			dirent.head = p[26] | (p[27] << 8);
670 			if (boot->ClustMask == CLUST32_MASK)
671 				dirent.head |= (p[20] << 16) | (p[21] << 24);
672 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
673 			if (vallfn) {
674 				strcpy(dirent.lname, longName);
675 				longName[0] = '\0';
676 				shortSum = -1;
677 			}
678 
679 			dirent.parent = dir;
680 			dirent.next = dir->child;
681 
682 			if (invlfn) {
683 				mod |= k = removede(f, boot, fat,
684 						    invlfn, vallfn ? vallfn : p,
685 						    invcl, vallfn ? valcl : cl, cl,
686 						    fullpath(&dirent), 0);
687 				if (mod & FSFATAL)
688 					return FSFATAL;
689 				if (vallfn
690 				    ? (valcl == cl && vallfn != buffer)
691 				    : p != buffer)
692 					if (k & FSDIRMOD)
693 						mod |= THISMOD;
694 			}
695 
696 			vallfn = NULL; /* not used any longer */
697 			invlfn = NULL;
698 
699 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
700 				if (dirent.head != 0) {
701 					pwarn("%s has clusters, but size 0\n",
702 					      fullpath(&dirent));
703 					if (ask(1, "Drop allocated clusters")) {
704 						p[26] = p[27] = 0;
705 						if (boot->ClustMask == CLUST32_MASK)
706 							p[20] = p[21] = 0;
707 						clearchain(boot, fat, dirent.head);
708 						dirent.head = 0;
709 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
710 					} else
711 						mod |= FSERROR;
712 				}
713 			} else if (dirent.head == 0
714 				   && !strcmp(dirent.name, "..")
715 				   && dir->parent			/* XXX */
716 				   && !dir->parent->parent) {
717 				/*
718 				 *  Do nothing, the parent is the root
719 				 */
720 			} else if (dirent.head < CLUST_FIRST
721 				   || dirent.head >= boot->NumClusters
722 				   || fat[dirent.head].next == CLUST_FREE
723 				   || (fat[dirent.head].next >= CLUST_RSRVD
724 				       && fat[dirent.head].next < CLUST_EOFS)
725 				   || fat[dirent.head].head != dirent.head) {
726 				if (dirent.head == 0)
727 					pwarn("%s has no clusters\n",
728 					      fullpath(&dirent));
729 				else if (dirent.head < CLUST_FIRST
730 					 || dirent.head >= boot->NumClusters)
731 					pwarn("%s starts with cluster out of range(%u)\n",
732 					      fullpath(&dirent),
733 					      dirent.head);
734 				else if (fat[dirent.head].next == CLUST_FREE)
735 					pwarn("%s starts with free cluster\n",
736 					      fullpath(&dirent));
737 				else if (fat[dirent.head].next >= CLUST_RSRVD)
738 					pwarn("%s starts with cluster marked %s\n",
739 					      fullpath(&dirent),
740 					      rsrvdcltype(fat[dirent.head].next));
741 				else
742 					pwarn("%s doesn't start a cluster chain\n",
743 					      fullpath(&dirent));
744 				if (dirent.flags & ATTR_DIRECTORY) {
745 					if (ask(0, "Remove")) {
746 						*p = SLOT_DELETED;
747 						mod |= THISMOD|FSDIRMOD;
748 					} else
749 						mod |= FSERROR;
750 					continue;
751 				} else {
752 					if (ask(1, "Truncate")) {
753 						p[28] = p[29] = p[30] = p[31] = 0;
754 						p[26] = p[27] = 0;
755 						if (boot->ClustMask == CLUST32_MASK)
756 							p[20] = p[21] = 0;
757 						dirent.size = 0;
758 						mod |= THISMOD|FSDIRMOD;
759 					} else
760 						mod |= FSERROR;
761 				}
762 			}
763 
764 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
765 				fat[dirent.head].flags |= FAT_USED;
766 
767 			if (dirent.flags & ATTR_DIRECTORY) {
768 				/*
769 				 * gather more info for directories
770 				 */
771 				struct dirTodoNode *n;
772 
773 				if (dirent.size) {
774 					pwarn("Directory %s has size != 0\n",
775 					      fullpath(&dirent));
776 					if (ask(1, "Correct")) {
777 						p[28] = p[29] = p[30] = p[31] = 0;
778 						dirent.size = 0;
779 						mod |= THISMOD|FSDIRMOD;
780 					} else
781 						mod |= FSERROR;
782 				}
783 				/*
784 				 * handle `.' and `..' specially
785 				 */
786 				if (strcmp(dirent.name, ".") == 0) {
787 					if (dirent.head != dir->head) {
788 						pwarn("`.' entry in %s has incorrect start cluster\n",
789 						      fullpath(dir));
790 						if (ask(1, "Correct")) {
791 							dirent.head = dir->head;
792 							p[26] = (u_char)dirent.head;
793 							p[27] = (u_char)(dirent.head >> 8);
794 							if (boot->ClustMask == CLUST32_MASK) {
795 								p[20] = (u_char)(dirent.head >> 16);
796 								p[21] = (u_char)(dirent.head >> 24);
797 							}
798 							mod |= THISMOD|FSDIRMOD;
799 						} else
800 							mod |= FSERROR;
801 					}
802 					continue;
803 				}
804 				if (strcmp(dirent.name, "..") == 0) {
805 					if (dir->parent) {		/* XXX */
806 						if (!dir->parent->parent) {
807 							if (dirent.head) {
808 								pwarn("`..' entry in %s has non-zero start cluster\n",
809 								      fullpath(dir));
810 								if (ask(1, "Correct")) {
811 									dirent.head = 0;
812 									p[26] = p[27] = 0;
813 									if (boot->ClustMask == CLUST32_MASK)
814 										p[20] = p[21] = 0;
815 									mod |= THISMOD|FSDIRMOD;
816 								} else
817 									mod |= FSERROR;
818 							}
819 						} else if (dirent.head != dir->parent->head) {
820 							pwarn("`..' entry in %s has incorrect start cluster\n",
821 							      fullpath(dir));
822 							if (ask(1, "Correct")) {
823 								dirent.head = dir->parent->head;
824 								p[26] = (u_char)dirent.head;
825 								p[27] = (u_char)(dirent.head >> 8);
826 								if (boot->ClustMask == CLUST32_MASK) {
827 									p[20] = (u_char)(dirent.head >> 16);
828 									p[21] = (u_char)(dirent.head >> 24);
829 								}
830 								mod |= THISMOD|FSDIRMOD;
831 							} else
832 								mod |= FSERROR;
833 						}
834 					}
835 					continue;
836 				}
837 
838 				/* create directory tree node */
839 				if (!(d = newDosDirEntry())) {
840 					perror("No space for directory");
841 					return FSFATAL;
842 				}
843 				memcpy(d, &dirent, sizeof(struct dosDirEntry));
844 				/* link it into the tree */
845 				dir->child = d;
846 
847 				/* Enter this directory into the todo list */
848 				if (!(n = newDirTodo())) {
849 					perror("No space for todo list");
850 					return FSFATAL;
851 				}
852 				n->next = pendingDirectories;
853 				n->dir = d;
854 				pendingDirectories = n;
855 			} else {
856 				mod |= k = checksize(boot, fat, p, &dirent);
857 				if (k & FSDIRMOD)
858 					mod |= THISMOD;
859 			}
860 			boot->NumFiles++;
861 		}
862 		if (mod & THISMOD) {
863 			last *= 32;
864 			if (lseek(f, off, SEEK_SET) != off
865 			    || write(f, buffer, last) != last) {
866 				perror("Unable to write directory");
867 				return FSFATAL;
868 			}
869 			mod &= ~THISMOD;
870 		}
871 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
872 	if (invlfn || vallfn)
873 		mod |= removede(f, boot, fat,
874 				invlfn ? invlfn : vallfn, p,
875 				invlfn ? invcl : valcl, -1, 0,
876 				fullpath(dir), 1);
877 	return mod & ~THISMOD;
878 }
879 
880 int
881 handleDirTree(dosfs, boot, fat)
882 	int dosfs;
883 	struct bootblock *boot;
884 	struct fatEntry *fat;
885 {
886 	int mod;
887 
888 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
889 	if (mod & FSFATAL)
890 		return FSFATAL;
891 
892 	/*
893 	 * process the directory todo list
894 	 */
895 	while (pendingDirectories) {
896 		struct dosDirEntry *dir = pendingDirectories->dir;
897 		struct dirTodoNode *n = pendingDirectories->next;
898 
899 		/*
900 		 * remove TODO entry now, the list might change during
901 		 * directory reads
902 		 */
903 		freeDirTodo(pendingDirectories);
904 		pendingDirectories = n;
905 
906 		/*
907 		 * handle subdirectory
908 		 */
909 		mod |= readDosDirSection(dosfs, boot, fat, dir);
910 		if (mod & FSFATAL)
911 			return FSFATAL;
912 	}
913 
914 	return mod;
915 }
916 
917 /*
918  * Try to reconnect a FAT chain into dir
919  */
920 static u_char *lfbuf;
921 static cl_t lfcl;
922 static off_t lfoff;
923 
924 int
925 reconnect(dosfs, boot, fat, head)
926 	int dosfs;
927 	struct bootblock *boot;
928 	struct fatEntry *fat;
929 	cl_t head;
930 {
931 	struct dosDirEntry d;
932 	u_char *p;
933 
934 	if (!ask(1, "Reconnect"))
935 		return FSERROR;
936 
937 	if (!lostDir) {
938 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
939 			if (!strcmp(lostDir->name, LOSTDIR))
940 				break;
941 		}
942 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
943 			pwarn("No %s directory\n", LOSTDIR);
944 			return FSERROR;
945 		}
946 	}
947 	if (!lfbuf) {
948 		lfbuf = malloc(boot->ClusterSize);
949 		if (!lfbuf) {
950 			perror("No space for buffer");
951 			return FSFATAL;
952 		}
953 		p = NULL;
954 	} else
955 		p = lfbuf;
956 	while (1) {
957 		if (p)
958 			for (; p < lfbuf + boot->ClusterSize; p += 32)
959 				if (*p == SLOT_EMPTY
960 				    || *p == SLOT_DELETED)
961 					break;
962 		if (p && p < lfbuf + boot->ClusterSize)
963 			break;
964 		lfcl = p ? fat[lfcl].next : lostDir->head;
965 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
966 			/* Extend LOSTDIR?				XXX */
967 			pwarn("No space in %s\n", LOSTDIR);
968 			return FSERROR;
969 		}
970 		lfoff = lfcl * boot->ClusterSize
971 		    + boot->ClusterOffset * boot->BytesPerSec;
972 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
973 		    || read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
974 			perror("could not read LOST.DIR");
975 			return FSFATAL;
976 		}
977 		p = lfbuf;
978 	}
979 
980 	boot->NumFiles++;
981 	/* Ensure uniqueness of entry here!				XXX */
982 	memset(&d, 0, sizeof d);
983 	(void)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 	memset(p, 0, 32);
989 	memset(p, ' ', 11);
990 	memcpy(p, d.name, strlen(d.name));
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 	    || write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
1004 		perror("could not write LOST.DIR");
1005 		return FSFATAL;
1006 	}
1007 	return FSDIRMOD;
1008 }
1009 
1010 void
1011 finishlf()
1012 {
1013 	if (lfbuf)
1014 		free(lfbuf);
1015 	lfbuf = NULL;
1016 }
1017