xref: /netbsd-src/sbin/fsck_msdos/dir.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: dir.c,v 1.23 2009/04/11 07:14:50 lukem Exp $	*/
2 
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 1.23 2009/04/11 07:14:50 lukem Exp $");
34 #endif /* not lint */
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <ctype.h>
40 #include <unistd.h>
41 #include <assert.h>
42 #include <time.h>
43 
44 #include <sys/param.h>
45 
46 #include "ext.h"
47 #include "fsutil.h"
48 
49 #define	SLOT_EMPTY	0x00		/* slot has never been used */
50 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
51 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
52 
53 #define	ATTR_NORMAL	0x00		/* normal file */
54 #define	ATTR_READONLY	0x01		/* file is readonly */
55 #define	ATTR_HIDDEN	0x02		/* file is hidden */
56 #define	ATTR_SYSTEM	0x04		/* file is a system file */
57 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
58 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
59 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
60 
61 #define	ATTR_WIN95	0x0f		/* long name record */
62 
63 /*
64  * This is the format of the contents of the deTime field in the direntry
65  * structure.
66  * We don't use bitfields because we don't know how compilers for
67  * arbitrary machines will lay them out.
68  */
69 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
70 #define DT_2SECONDS_SHIFT	0
71 #define DT_MINUTES_MASK		0x7E0	/* minutes */
72 #define DT_MINUTES_SHIFT	5
73 #define DT_HOURS_MASK		0xF800	/* hours */
74 #define DT_HOURS_SHIFT		11
75 
76 /*
77  * This is the format of the contents of the deDate field in the direntry
78  * structure.
79  */
80 #define DD_DAY_MASK		0x1F	/* day of month */
81 #define DD_DAY_SHIFT		0
82 #define DD_MONTH_MASK		0x1E0	/* month */
83 #define DD_MONTH_SHIFT		5
84 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
85 #define DD_YEAR_SHIFT		9
86 
87 
88 /* dir.c */
89 static struct dosDirEntry *newDosDirEntry(void);
90 static void freeDosDirEntry(struct dosDirEntry *);
91 static struct dirTodoNode *newDirTodo(void);
92 static void freeDirTodo(struct dirTodoNode *);
93 static char *fullpath(struct dosDirEntry *);
94 static u_char calcShortSum(u_char *);
95 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
96     cl_t, int, int);
97 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
98     u_char *, cl_t, cl_t, cl_t, char *, int);
99 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
100     struct dosDirEntry *);
101 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
102     struct dosDirEntry *);
103 
104 /*
105  * Manage free dosDirEntry structures.
106  */
107 static struct dosDirEntry *freede;
108 
109 static struct dosDirEntry *
110 newDosDirEntry(void)
111 {
112 	struct dosDirEntry *de;
113 
114 	if (!(de = freede)) {
115 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
116 			return 0;
117 	} else
118 		freede = de->next;
119 	return de;
120 }
121 
122 static void
123 freeDosDirEntry(struct dosDirEntry *de)
124 {
125 	de->next = freede;
126 	freede = de;
127 }
128 
129 /*
130  * The same for dirTodoNode structures.
131  */
132 static struct dirTodoNode *freedt;
133 
134 static struct dirTodoNode *
135 newDirTodo(void)
136 {
137 	struct dirTodoNode *dt;
138 
139 	if (!(dt = freedt)) {
140 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
141 			return 0;
142 	} else
143 		freedt = dt->next;
144 	return dt;
145 }
146 
147 static void
148 freeDirTodo(struct dirTodoNode *dt)
149 {
150 	dt->next = freedt;
151 	freedt = dt;
152 }
153 
154 /*
155  * The stack of unread directories
156  */
157 struct dirTodoNode *pendingDirectories = NULL;
158 
159 /*
160  * Return the full pathname for a directory entry.
161  */
162 static char *
163 fullpath(struct dosDirEntry *dir)
164 {
165 	static char namebuf[MAXPATHLEN + 1];
166 	char *cp, *np;
167 	int nl;
168 
169 	cp = namebuf + sizeof namebuf - 1;
170 	*cp = '\0';
171 	do {
172 		np = dir->lname[0] ? dir->lname : dir->name;
173 		nl = strlen(np);
174 		if ((cp -= nl) <= namebuf + 1)
175 			break;
176 		memcpy(cp, np, nl);
177 		*--cp = '/';
178 	} while ((dir = dir->parent) != NULL);
179 	if (dir)
180 		*--cp = '?';
181 	else
182 		cp++;
183 	return cp;
184 }
185 
186 /*
187  * Calculate a checksum over an 8.3 alias name
188  */
189 static u_char
190 calcShortSum(u_char *p)
191 {
192 	u_char sum = 0;
193 	int i;
194 
195 	for (i = 0; i < 11; i++) {
196 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
197 		sum += p[i];
198 	}
199 
200 	return sum;
201 }
202 
203 /*
204  * Global variables temporarily used during a directory scan
205  */
206 static char longName[DOSLONGNAMELEN] = "";
207 static u_char *buffer = NULL;
208 static u_char *delbuf = NULL;
209 
210 struct dosDirEntry *rootDir;
211 static struct dosDirEntry *lostDir;
212 
213 /*
214  * Init internal state for a new directory scan.
215  */
216 int
217 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
218 {
219 	int b1, b2;
220 	cl_t cl;
221 	int ret = FSOK;
222 	size_t len;
223 
224 	b1 = boot->RootDirEnts * 32;
225 	b2 = boot->SecPerClust * boot->BytesPerSec;
226 
227 	if ((buffer = malloc(len = b1 > b2 ? b1 : b2)) == NULL) {
228 		perr("No space for directory buffer (%zu)", len);
229 		return FSFATAL;
230 	}
231 
232 	if ((delbuf = malloc(len = b2)) == NULL) {
233 		free(buffer);
234 		perr("No space for directory delbuf (%zu)", len);
235 		return FSFATAL;
236 	}
237 
238 	if ((rootDir = newDosDirEntry()) == NULL) {
239 		free(buffer);
240 		free(delbuf);
241 		perr("No space for directory entry");
242 		return FSFATAL;
243 	}
244 
245 	memset(rootDir, 0, sizeof *rootDir);
246 	if (boot->flags & FAT32) {
247 		if (boot->RootCl < CLUST_FIRST || boot->RootCl >= boot->NumClusters) {
248 			pfatal("Root directory starts with cluster out of range(%u)",
249 			       boot->RootCl);
250 			return FSFATAL;
251 		}
252 		cl = fat[boot->RootCl].next;
253 		if (cl < CLUST_FIRST
254 		    || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
255 		    || fat[boot->RootCl].head != boot->RootCl) {
256 			if (cl == CLUST_FREE)
257 				pwarn("Root directory starts with free cluster\n");
258 			else if (cl >= CLUST_RSRVD)
259 				pwarn("Root directory starts with cluster marked %s\n",
260 				      rsrvdcltype(cl));
261 			else {
262 				pfatal("Root directory doesn't start a cluster chain");
263 				return FSFATAL;
264 			}
265 			if (ask(1, "Fix")) {
266 				fat[boot->RootCl].next = CLUST_FREE;
267 				ret = FSFATMOD;
268 			} else
269 				ret = FSFATAL;
270 		}
271 
272 		fat[boot->RootCl].flags |= FAT_USED;
273 		rootDir->head = boot->RootCl;
274 	}
275 
276 	return ret;
277 }
278 
279 /*
280  * Cleanup after a directory scan
281  */
282 void
283 finishDosDirSection(void)
284 {
285 	struct dirTodoNode *p, *np;
286 	struct dosDirEntry *d, *nd;
287 
288 	for (p = pendingDirectories; p; p = np) {
289 		np = p->next;
290 		freeDirTodo(p);
291 	}
292 	pendingDirectories = 0;
293 	for (d = rootDir; d; d = nd) {
294 		if ((nd = d->child) != NULL) {
295 			d->child = 0;
296 			continue;
297 		}
298 		if (!(nd = d->next))
299 			nd = d->parent;
300 		freeDosDirEntry(d);
301 	}
302 	rootDir = lostDir = NULL;
303 	free(buffer);
304 	free(delbuf);
305 	buffer = NULL;
306 	delbuf = NULL;
307 }
308 
309 /*
310  * Delete directory entries between startcl, startoff and endcl, endoff.
311  */
312 static int
313 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
314        int startoff, cl_t endcl, int endoff, int notlast)
315 {
316 	u_char *s, *e;
317 	off_t off;
318 	int clsz = boot->SecPerClust * boot->BytesPerSec;
319 
320 	s = delbuf + startoff;
321 	e = delbuf + clsz;
322 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
323 		if (startcl == endcl) {
324 			if (notlast)
325 				break;
326 			e = delbuf + endoff;
327 		}
328 		off = startcl * boot->SecPerClust + boot->ClusterOffset;
329 		off *= boot->BytesPerSec;
330 		if (lseek(f, off, SEEK_SET) != off
331 		    || read(f, delbuf, clsz) != clsz) {
332 			perr("Unable to read directory");
333 			return FSFATAL;
334 		}
335 		while (s < e) {
336 			*s = SLOT_DELETED;
337 			s += 32;
338 		}
339 		if (lseek(f, off, SEEK_SET) != off
340 		    || write(f, delbuf, clsz) != clsz) {
341 			perr("Unable to write directory");
342 			return FSFATAL;
343 		}
344 		if (startcl == endcl)
345 			break;
346 		startcl = fat[startcl].next;
347 		s = delbuf;
348 	}
349 	return FSOK;
350 }
351 
352 static int
353 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
354          u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path,
355 	 int type)
356 {
357 	switch (type) {
358 	case 0:
359 		pwarn("Invalid long filename entry for %s\n", path);
360 		break;
361 	case 1:
362 		pwarn("Invalid long filename entry at end of directory %s\n", path);
363 		break;
364 	case 2:
365 		pwarn("Invalid long filename entry for volume label\n");
366 		break;
367 	}
368 	if (ask(0, "Remove")) {
369 		if (startcl != curcl) {
370 			if (delete(f, boot, fat,
371 				   startcl, start - buffer,
372 				   endcl, end - buffer,
373 				   endcl == curcl) == FSFATAL)
374 				return FSFATAL;
375 			start = buffer;
376 		}
377 		/* startcl is < CLUST_FIRST for !fat32 root */
378 		if ((endcl == curcl) || (startcl < CLUST_FIRST))
379 			for (; start < end; start += 32)
380 				*start = SLOT_DELETED;
381 		return FSDIRMOD;
382 	}
383 	return FSERROR;
384 }
385 
386 /*
387  * Check an in-memory file entry
388  */
389 static int
390 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
391 	  struct dosDirEntry *dir)
392 {
393 	/*
394 	 * Check size on ordinary files
395 	 */
396 	u_int32_t physicalSize;
397 
398 	if (dir->head == CLUST_FREE)
399 		physicalSize = 0;
400 	else {
401 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
402 			return FSERROR;
403 		physicalSize = fat[dir->head].length * boot->ClusterSize;
404 	}
405 	if (physicalSize < dir->size) {
406 		pwarn("size of %s is %u, should at most be %u\n",
407 		      fullpath(dir), dir->size, physicalSize);
408 		if (ask(1, "Truncate")) {
409 			dir->size = physicalSize;
410 			p[28] = (u_char)physicalSize;
411 			p[29] = (u_char)(physicalSize >> 8);
412 			p[30] = (u_char)(physicalSize >> 16);
413 			p[31] = (u_char)(physicalSize >> 24);
414 			return FSDIRMOD;
415 		} else
416 			return FSERROR;
417 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
418 		pwarn("%s has too many clusters allocated\n",
419 		      fullpath(dir));
420 		if (ask(1, "Drop superfluous clusters")) {
421 			cl_t cl;
422 			u_int32_t sz = 0;
423 
424 			for (cl = dir->head; (sz += boot->ClusterSize) < dir->size;)
425 				cl = fat[cl].next;
426 			clearchain(boot, fat, fat[cl].next);
427 			fat[cl].next = CLUST_EOF;
428 			return FSFATMOD;
429 		} else
430 			return FSERROR;
431 	}
432 	return FSOK;
433 }
434 
435 /*
436  * Read a directory and
437  *   - resolve long name records
438  *   - enter file and directory records into the parent's list
439  *   - push directories onto the todo-stack
440  */
441 static int
442 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
443 		  struct dosDirEntry *dir)
444 {
445 	struct dosDirEntry dirent, *d;
446 	u_char *p, *vallfn, *invlfn, *empty;
447 	off_t off;
448 	int i, j, k, last;
449 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
450 	char *t;
451 	u_int lidx = 0;
452 	int shortSum;
453 	int mod = FSOK;
454 #define	THISMOD	0x8000			/* Only used within this routine */
455 
456 	cl = dir->head;
457 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
458 		/*
459 		 * Already handled somewhere else.
460 		 */
461 		return FSOK;
462 	}
463 	shortSum = -1;
464 	vallfn = invlfn = empty = NULL;
465 	do {
466 		if (!(boot->flags & FAT32) && !dir->parent) {
467 			last = boot->RootDirEnts * 32;
468 			off = boot->ResSectors + boot->FATs * boot->FATsecs;
469 		} else {
470 			last = boot->SecPerClust * boot->BytesPerSec;
471 			off = cl * boot->SecPerClust + boot->ClusterOffset;
472 		}
473 
474 		off *= boot->BytesPerSec;
475 		if (lseek(f, off, SEEK_SET) != off
476 		    || read(f, buffer, last) != last) {
477 			perr("Unable to read directory");
478 			return FSFATAL;
479 		}
480 		last /= 32;
481 		/*
482 		 * Check `.' and `..' entries here?			XXX
483 		 */
484 		for (p = buffer, i = 0; i < last; i++, p += 32) {
485 			if (dir->fsckflags & DIREMPWARN) {
486 				*p = SLOT_EMPTY;
487 				continue;
488 			}
489 
490 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
491 				if (*p == SLOT_EMPTY) {
492 					dir->fsckflags |= DIREMPTY;
493 					empty = p;
494 					empcl = cl;
495 				}
496 				continue;
497 			}
498 
499 			if (dir->fsckflags & DIREMPTY) {
500 				if (!(dir->fsckflags & DIREMPWARN)) {
501 					pwarn("%s has entries after end of directory\n",
502 					      fullpath(dir));
503 					if (ask(1, "Extend")) {
504 						u_char *q;
505 
506 						dir->fsckflags &= ~DIREMPTY;
507 						if (delete(f, boot, fat,
508 							   empcl, empty - buffer,
509 							   cl, p - buffer, 1) == FSFATAL)
510 							return FSFATAL;
511 						q = empcl == cl ? empty : buffer;
512 						assert(q != NULL);
513 						for (; q < p; q += 32)
514 							*q = SLOT_DELETED;
515 						mod |= THISMOD|FSDIRMOD;
516 					} else if (ask(0, "Truncate"))
517 						dir->fsckflags |= DIREMPWARN;
518 				}
519 				if (dir->fsckflags & DIREMPWARN) {
520 					*p = SLOT_DELETED;
521 					mod |= THISMOD|FSDIRMOD;
522 					continue;
523 				} else if (dir->fsckflags & DIREMPTY)
524 					mod |= FSERROR;
525 				empty = NULL;
526 			}
527 
528 			if (p[11] == ATTR_WIN95) {
529 				if (*p & LRFIRST) {
530 					if (shortSum != -1) {
531 						if (!invlfn) {
532 							invlfn = vallfn;
533 							invcl = valcl;
534 						}
535 					}
536 					memset(longName, 0, sizeof longName);
537 					shortSum = p[13];
538 					vallfn = p;
539 					valcl = cl;
540 				} else if (shortSum != p[13]
541 					   || lidx != (*p & LRNOMASK)) {
542 					if (!invlfn) {
543 						invlfn = vallfn;
544 						invcl = valcl;
545 					}
546 					if (!invlfn) {
547 						invlfn = p;
548 						invcl = cl;
549 					}
550 					vallfn = NULL;
551 				}
552 				lidx = *p & LRNOMASK;
553 				t = longName + --lidx * 13;
554 				for (k = 1; k < 11 && t < longName + sizeof(longName); k += 2) {
555 					if (!p[k] && !p[k + 1])
556 						break;
557 					*t++ = p[k];
558 					/*
559 					 * Warn about those unusable chars in msdosfs here?	XXX
560 					 */
561 					if (p[k + 1])
562 						t[-1] = '?';
563 				}
564 				if (k >= 11)
565 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
566 						if (!p[k] && !p[k + 1])
567 							break;
568 						*t++ = p[k];
569 						if (p[k + 1])
570 							t[-1] = '?';
571 					}
572 				if (k >= 26)
573 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
574 						if (!p[k] && !p[k + 1])
575 							break;
576 						*t++ = p[k];
577 						if (p[k + 1])
578 							t[-1] = '?';
579 					}
580 				if (t >= longName + sizeof(longName)) {
581 					pwarn("long filename too long\n");
582 					if (!invlfn) {
583 						invlfn = vallfn;
584 						invcl = valcl;
585 					}
586 					vallfn = NULL;
587 				}
588 				if (p[26] | (p[27] << 8)) {
589 					pwarn("long filename record cluster start != 0\n");
590 					if (!invlfn) {
591 						invlfn = vallfn;
592 						invcl = cl;
593 					}
594 					vallfn = NULL;
595 				}
596 				continue;	/* long records don't carry further
597 						 * information */
598 			}
599 
600 			/*
601 			 * This is a standard msdosfs directory entry.
602 			 */
603 			memset(&dirent, 0, sizeof dirent);
604 
605 			/*
606 			 * it's a short name record, but we need to know
607 			 * more, so get the flags first.
608 			 */
609 			dirent.flags = p[11];
610 
611 			/*
612 			 * Translate from 850 to ISO here		XXX
613 			 */
614 			for (j = 0; j < 8; j++)
615 				dirent.name[j] = p[j];
616 			dirent.name[8] = '\0';
617 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
618 				dirent.name[k] = '\0';
619 			if (dirent.name[k] != '\0')
620 				k++;
621 			if (dirent.name[0] == SLOT_E5)
622 				dirent.name[0] = 0xe5;
623 
624 			if (dirent.flags & ATTR_VOLUME) {
625 				if (vallfn || invlfn) {
626 					mod |= removede(f, boot, fat,
627 							invlfn ? invlfn : vallfn, p,
628 							invlfn ? invcl : valcl, -1, 0,
629 							fullpath(dir), 2);
630 					vallfn = NULL;
631 					invlfn = NULL;
632 				}
633 				continue;
634 			}
635 
636 			if (p[8] != ' ')
637 				dirent.name[k++] = '.';
638 			for (j = 0; j < 3; j++)
639 				dirent.name[k++] = p[j+8];
640 			dirent.name[k] = '\0';
641 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
642 				dirent.name[k] = '\0';
643 
644 			if (vallfn && shortSum != calcShortSum(p)) {
645 				if (!invlfn) {
646 					invlfn = vallfn;
647 					invcl = valcl;
648 				}
649 				vallfn = NULL;
650 			}
651 			dirent.head = p[26] | (p[27] << 8);
652 			if (boot->ClustMask == CLUST32_MASK)
653 				dirent.head |= (p[20] << 16) | (p[21] << 24);
654 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
655 			if (vallfn) {
656 				strlcpy(dirent.lname, longName,
657 				    sizeof(dirent.lname));
658 				longName[0] = '\0';
659 				shortSum = -1;
660 			}
661 
662 			dirent.parent = dir;
663 			dirent.next = dir->child;
664 
665 			if (invlfn) {
666 				mod |= k = removede(f, boot, fat,
667 						    invlfn, vallfn ? vallfn : p,
668 						    invcl, vallfn ? valcl : cl, cl,
669 						    fullpath(&dirent), 0);
670 				if (mod & FSFATAL)
671 					return FSFATAL;
672 				if (vallfn
673 				    ? (valcl == cl && vallfn != buffer)
674 				    : p != buffer)
675 					if (k & FSDIRMOD)
676 						mod |= THISMOD;
677 			}
678 
679 			vallfn = NULL; /* not used any longer */
680 			invlfn = NULL;
681 
682 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
683 				if (dirent.head != 0) {
684 					pwarn("%s has clusters, but size 0\n",
685 					      fullpath(&dirent));
686 					if (ask(1, "Drop allocated clusters")) {
687 						p[26] = p[27] = 0;
688 						if (boot->ClustMask == CLUST32_MASK)
689 							p[20] = p[21] = 0;
690 						clearchain(boot, fat, dirent.head);
691 						dirent.head = 0;
692 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
693 					} else
694 						mod |= FSERROR;
695 				}
696 			} else if (dirent.head == 0
697 				   && !strcmp(dirent.name, "..")
698 				   && dir->parent			/* XXX */
699 				   && !dir->parent->parent) {
700 				/*
701 				 *  Do nothing, the parent is the root
702 				 */
703 			} else if (dirent.head < CLUST_FIRST
704 				   || dirent.head >= boot->NumClusters
705 				   || fat[dirent.head].next == CLUST_FREE
706 				   || (fat[dirent.head].next >= CLUST_RSRVD
707 				       && fat[dirent.head].next < CLUST_EOFS)
708 				   || fat[dirent.head].head != dirent.head) {
709 				if (dirent.head == 0)
710 					pwarn("%s has no clusters\n",
711 					      fullpath(&dirent));
712 				else if (dirent.head < CLUST_FIRST
713 					 || dirent.head >= boot->NumClusters)
714 					pwarn("%s starts with cluster out of range(%u)\n",
715 					      fullpath(&dirent),
716 					      dirent.head);
717 				else if (fat[dirent.head].next == CLUST_FREE)
718 					pwarn("%s starts with free cluster\n",
719 					      fullpath(&dirent));
720 				else if (fat[dirent.head].next >= CLUST_RSRVD)
721 					pwarn("%s starts with cluster marked %s\n",
722 					      fullpath(&dirent),
723 					      rsrvdcltype(fat[dirent.head].next));
724 				else
725 					pwarn("%s doesn't start a cluster chain\n",
726 					      fullpath(&dirent));
727 				if (dirent.flags & ATTR_DIRECTORY) {
728 					if (ask(0, "Remove")) {
729 						*p = SLOT_DELETED;
730 						mod |= THISMOD|FSDIRMOD;
731 					} else
732 						mod |= FSERROR;
733 					continue;
734 				} else {
735 					if (ask(1, "Truncate")) {
736 						p[28] = p[29] = p[30] = p[31] = 0;
737 						p[26] = p[27] = 0;
738 						if (boot->ClustMask == CLUST32_MASK)
739 							p[20] = p[21] = 0;
740 						dirent.size = 0;
741 						mod |= THISMOD|FSDIRMOD;
742 					} else
743 						mod |= FSERROR;
744 				}
745 			}
746 
747 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
748 				fat[dirent.head].flags |= FAT_USED;
749 
750 			if (dirent.flags & ATTR_DIRECTORY) {
751 				/*
752 				 * gather more info for directories
753 				 */
754 				struct dirTodoNode *n;
755 
756 				if (dirent.size) {
757 					pwarn("Directory %s has size != 0\n",
758 					      fullpath(&dirent));
759 					if (ask(1, "Correct")) {
760 						p[28] = p[29] = p[30] = p[31] = 0;
761 						dirent.size = 0;
762 						mod |= THISMOD|FSDIRMOD;
763 					} else
764 						mod |= FSERROR;
765 				}
766 				/*
767 				 * handle `.' and `..' specially
768 				 */
769 				if (strcmp(dirent.name, ".") == 0) {
770 					if (dirent.head != dir->head) {
771 						pwarn("`.' entry in %s has incorrect start cluster\n",
772 						      fullpath(dir));
773 						if (ask(1, "Correct")) {
774 							dirent.head = dir->head;
775 							p[26] = (u_char)dirent.head;
776 							p[27] = (u_char)(dirent.head >> 8);
777 							if (boot->ClustMask == CLUST32_MASK) {
778 								p[20] = (u_char)(dirent.head >> 16);
779 								p[21] = (u_char)(dirent.head >> 24);
780 							}
781 							mod |= THISMOD|FSDIRMOD;
782 						} else
783 							mod |= FSERROR;
784 					}
785 					continue;
786 				}
787 				if (strcmp(dirent.name, "..") == 0) {
788 					if (dir->parent) {		/* XXX */
789 						if (!dir->parent->parent) {
790 							if (dirent.head) {
791 								pwarn("`..' entry in %s has non-zero start cluster\n",
792 								      fullpath(dir));
793 								if (ask(1, "Correct")) {
794 									dirent.head = 0;
795 									p[26] = p[27] = 0;
796 									if (boot->ClustMask == CLUST32_MASK)
797 										p[20] = p[21] = 0;
798 									mod |= THISMOD|FSDIRMOD;
799 								} else
800 									mod |= FSERROR;
801 							}
802 						} else if (dirent.head != dir->parent->head) {
803 							pwarn("`..' entry in %s has incorrect start cluster\n",
804 							      fullpath(dir));
805 							if (ask(1, "Correct")) {
806 								dirent.head = dir->parent->head;
807 								p[26] = (u_char)dirent.head;
808 								p[27] = (u_char)(dirent.head >> 8);
809 								if (boot->ClustMask == CLUST32_MASK) {
810 									p[20] = (u_char)(dirent.head >> 16);
811 									p[21] = (u_char)(dirent.head >> 24);
812 								}
813 								mod |= THISMOD|FSDIRMOD;
814 							} else
815 								mod |= FSERROR;
816 						}
817 					}
818 					continue;
819 				}
820 
821 				/* create directory tree node */
822 				if (!(d = newDosDirEntry())) {
823 					perr("No space for directory");
824 					return FSFATAL;
825 				}
826 				memcpy(d, &dirent, sizeof(struct dosDirEntry));
827 				/* link it into the tree */
828 				dir->child = d;
829 
830 				/* Enter this directory into the todo list */
831 				if (!(n = newDirTodo())) {
832 					perr("No space for todo list");
833 					return FSFATAL;
834 				}
835 				n->next = pendingDirectories;
836 				n->dir = d;
837 				pendingDirectories = n;
838 			} else {
839 				mod |= k = checksize(boot, fat, p, &dirent);
840 				if (k & FSDIRMOD)
841 					mod |= THISMOD;
842 			}
843 			boot->NumFiles++;
844 		}
845 
846 		if (!(boot->flags & FAT32) && !dir->parent)
847 			break;
848 
849 		if (mod & THISMOD) {
850 			last *= 32;
851 			if (lseek(f, off, SEEK_SET) != off
852 			    || write(f, buffer, last) != last) {
853 				perr("Unable to write directory");
854 				return FSFATAL;
855 			}
856 			mod &= ~THISMOD;
857 		}
858 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
859 	if (invlfn || vallfn)
860 		mod |= removede(f, boot, fat,
861 				invlfn ? invlfn : vallfn, p,
862 				invlfn ? invcl : valcl, -1, 0,
863 				fullpath(dir), 1);
864 
865 	/* The root directory of non fat32 filesystems is in a special
866 	 * area and may have been modified above without being written out.
867 	 */
868 	if ((mod & FSDIRMOD) && !(boot->flags & FAT32) && !dir->parent) {
869 		last *= 32;
870 		if (lseek(f, off, SEEK_SET) != off
871 		    || write(f, buffer, last) != last) {
872 			perr("Unable to write directory");
873 			return FSFATAL;
874 		}
875 		mod &= ~THISMOD;
876 	}
877 	return mod & ~THISMOD;
878 }
879 
880 int
881 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
882 {
883 	int mod;
884 
885 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
886 	if (mod & FSFATAL)
887 		return FSFATAL;
888 
889 	/*
890 	 * process the directory todo list
891 	 */
892 	while (pendingDirectories) {
893 		struct dosDirEntry *dir = pendingDirectories->dir;
894 		struct dirTodoNode *n = pendingDirectories->next;
895 
896 		/*
897 		 * remove TODO entry now, the list might change during
898 		 * directory reads
899 		 */
900 		freeDirTodo(pendingDirectories);
901 		pendingDirectories = n;
902 
903 		/*
904 		 * handle subdirectory
905 		 */
906 		mod |= readDosDirSection(dosfs, boot, fat, dir);
907 		if (mod & FSFATAL)
908 			return FSFATAL;
909 	}
910 
911 	return mod;
912 }
913 
914 /*
915  * Try to reconnect a FAT chain into dir
916  */
917 static u_char *lfbuf;
918 static cl_t lfcl;
919 static off_t lfoff;
920 
921 int
922 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
923 {
924 	struct dosDirEntry d;
925 	u_char *p;
926 
927 	if (!ask(1, "Reconnect"))
928 		return FSERROR;
929 
930 	if (!lostDir) {
931 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
932 			if (!strcmp(lostDir->name, LOSTDIR))
933 				break;
934 		}
935 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
936 			pwarn("No %s directory\n", LOSTDIR);
937 			return FSERROR;
938 		}
939 	}
940 	if (!lfbuf) {
941 		lfbuf = malloc(boot->ClusterSize);
942 		if (!lfbuf) {
943 			perr("No space for buffer");
944 			return FSFATAL;
945 		}
946 		p = NULL;
947 	} else
948 		p = lfbuf;
949 	while (1) {
950 		if (p)
951 			for (; p < lfbuf + boot->ClusterSize; p += 32)
952 				if (*p == SLOT_EMPTY
953 				    || *p == SLOT_DELETED)
954 					break;
955 		if (p && p < lfbuf + boot->ClusterSize)
956 			break;
957 		lfcl = p ? fat[lfcl].next : lostDir->head;
958 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
959 			/* Extend LOSTDIR?				XXX */
960 			pwarn("No space in %s\n", LOSTDIR);
961 			return FSERROR;
962 		}
963 		lfoff = lfcl * boot->ClusterSize
964 		    + boot->ClusterOffset * boot->BytesPerSec;
965 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
966 		    || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
967 			perr("could not read LOST.DIR");
968 			return FSFATAL;
969 		}
970 		p = lfbuf;
971 	}
972 
973 	boot->NumFiles++;
974 	/* Ensure uniqueness of entry here!				XXX */
975 	memset(&d, 0, sizeof d);
976 	(void)snprintf(d.name, sizeof(d.name), "%u", head);
977 	d.flags = 0;
978 	d.head = head;
979 	d.size = fat[head].length * boot->ClusterSize;
980 
981 	memset(p, 0, 32);
982 	memset(p, ' ', 11);
983 	memcpy(p, d.name, strlen(d.name));
984 	p[26] = (u_char)d.head;
985 	p[27] = (u_char)(d.head >> 8);
986 	if (boot->ClustMask == CLUST32_MASK) {
987 		p[20] = (u_char)(d.head >> 16);
988 		p[21] = (u_char)(d.head >> 24);
989 	}
990 	p[28] = (u_char)d.size;
991 	p[29] = (u_char)(d.size >> 8);
992 	p[30] = (u_char)(d.size >> 16);
993 	p[31] = (u_char)(d.size >> 24);
994 	fat[head].flags |= FAT_USED;
995 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
996 	    || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
997 		perr("could not write LOST.DIR");
998 		return FSFATAL;
999 	}
1000 	return FSDIRMOD;
1001 }
1002 
1003 void
1004 finishlf(void)
1005 {
1006 	if (lfbuf)
1007 		free(lfbuf);
1008 	lfbuf = NULL;
1009 }
1010