xref: /openbsd/sbin/fsck_msdos/dir.c (revision cecf84d4)
1 /*	$OpenBSD: dir.c,v 1.28 2015/01/16 06:39:58 deraadt Exp $	*/
2 /*	$NetBSD: dir.c,v 1.11 1997/10/17 11:19:35 ws Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
6  * Copyright (c) 1995 Martin Husemann
7  * Some structure declaration borrowed from Paul Popelka
8  * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <ctype.h>
35 #include <unistd.h>
36 #include <limits.h>
37 #include <time.h>
38 
39 #include "ext.h"
40 
41 #define	SLOT_EMPTY	0x00		/* slot has never been used */
42 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
43 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
44 
45 #define	ATTR_NORMAL	0x00		/* normal file */
46 #define	ATTR_READONLY	0x01		/* file is readonly */
47 #define	ATTR_HIDDEN	0x02		/* file is hidden */
48 #define	ATTR_SYSTEM	0x04		/* file is a system file */
49 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
50 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
51 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
52 
53 #define	ATTR_WIN95	0x0f		/* long name record */
54 
55 /*
56  * This is the format of the contents of the deTime field in the direntry
57  * structure.
58  * We don't use bitfields because we don't know how compilers for
59  * arbitrary machines will lay them out.
60  */
61 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
62 #define DT_2SECONDS_SHIFT	0
63 #define DT_MINUTES_MASK		0x7E0	/* minutes */
64 #define DT_MINUTES_SHIFT	5
65 #define DT_HOURS_MASK		0xF800	/* hours */
66 #define DT_HOURS_SHIFT		11
67 
68 /*
69  * This is the format of the contents of the deDate field in the direntry
70  * structure.
71  */
72 #define DD_DAY_MASK		0x1F	/* day of month */
73 #define DD_DAY_SHIFT		0
74 #define DD_MONTH_MASK		0x1E0	/* month */
75 #define DD_MONTH_SHIFT		5
76 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
77 #define DD_YEAR_SHIFT		9
78 
79 /* dir.c */
80 static struct dosDirEntry *newDosDirEntry(void);
81 static void freeDosDirEntry(struct dosDirEntry *);
82 static struct dirTodoNode *newDirTodo(void);
83 static void freeDirTodo(struct dirTodoNode *);
84 static char *fullpath(struct dosDirEntry *);
85 static u_char calcShortSum(u_char *);
86 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
87     cl_t, int, int);
88 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
89     u_char *, cl_t, cl_t, cl_t, char *, int);
90 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
91     struct dosDirEntry *);
92 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
93     struct dosDirEntry *);
94 
95 /*
96  * Manage free dosDirEntry structures.
97  */
98 static struct dosDirEntry *freede;
99 
100 static struct dosDirEntry *
101 newDosDirEntry(void)
102 {
103 	struct dosDirEntry *de;
104 
105 	if (!(de = freede)) {
106 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
107 			return (0);
108 	} else
109 		freede = de->next;
110 	return (de);
111 }
112 
113 static void
114 freeDosDirEntry(struct dosDirEntry *de)
115 {
116 	de->next = freede;
117 	freede = de;
118 }
119 
120 /*
121  * The same for dirTodoNode structures.
122  */
123 static struct dirTodoNode *freedt;
124 
125 static struct dirTodoNode *
126 newDirTodo(void)
127 {
128 	struct dirTodoNode *dt;
129 
130 	if (!(dt = freedt)) {
131 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
132 			return (0);
133 	} else
134 		freedt = dt->next;
135 	return (dt);
136 }
137 
138 static void
139 freeDirTodo(struct dirTodoNode *dt)
140 {
141 	dt->next = freedt;
142 	freedt = dt;
143 }
144 
145 /*
146  * The stack of unread directories
147  */
148 static struct dirTodoNode *pendingDirectories = NULL;
149 
150 /*
151  * Return the full pathname for a directory entry.
152  */
153 static char *
154 fullpath(struct dosDirEntry *dir)
155 {
156 	static char namebuf[PATH_MAX + 1];
157 	char *cp, *np;
158 	int nl;
159 
160 	cp = namebuf + sizeof namebuf;
161 	*--cp = '\0';
162 	for(;;) {
163 		np = dir->lname[0] ? dir->lname : dir->name;
164 		nl = strlen(np);
165 			/* cf dosDirEntry, sizeof(lname) < MAXPATHLEN, so test is safe */
166 		if (cp <= namebuf + 1 + nl) {
167 			*--cp = '?';
168 			break;
169 		}
170 		cp -= nl;
171 		(void)memcpy(cp, np, nl);
172 		dir = dir->parent;
173 		if (!dir)
174 			break;
175 		*--cp = '/';
176 	}
177 	return (cp);
178 }
179 
180 /*
181  * Calculate a checksum over an 8.3 alias name
182  */
183 static u_char
184 calcShortSum(u_char *p)
185 {
186 	u_char sum = 0;
187 	int i;
188 
189 	for (i = 0; i < 11; i++) {
190 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
191 		sum += p[i];
192 	}
193 
194 	return (sum);
195 }
196 
197 /*
198  * Global variables temporarily used during a directory scan
199  */
200 static char longName[DOSLONGNAMELEN] = "";
201 static u_char *buffer = NULL;
202 static u_char *delbuf = NULL;
203 
204 static struct dosDirEntry *rootDir;
205 static struct dosDirEntry *lostDir;
206 
207 /*
208  * Init internal state for a new directory scan.
209  */
210 int
211 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
212 {
213 	int b1, b2;
214 	int ret = FSOK;
215 
216 	b1 = boot->RootDirEnts * 32;
217 	b2 = boot->SecPerClust * boot->BytesPerSec;
218 
219 	if (!(buffer = malloc(b1 > b2 ? b1 : b2))
220 	    || !(delbuf = malloc(b2))
221 	    || !(rootDir = newDosDirEntry())) {
222 		xperror("No space for directory");
223 		goto fail;
224 	}
225 	(void)memset(rootDir, 0, sizeof *rootDir);
226 	if (boot->flags & FAT32) {
227 		if (boot->RootCl < CLUST_FIRST || boot->RootCl >= boot->NumClusters) {
228 			pfatal("Root directory starts with cluster out of range(%u)\n",
229 			       boot->RootCl);
230 			goto fail;
231 		}
232 		if (fat[boot->RootCl].head != boot->RootCl) {
233 			pfatal("Root directory doesn't start a cluster chain\n");
234 			goto fail;
235 		}
236 
237 		fat[boot->RootCl].flags |= FAT_USED;
238 		rootDir->head = boot->RootCl;
239 	}
240 
241 	return (ret);
242 fail:
243 	finishDosDirSection();
244 	return (FSFATAL);
245 }
246 
247 /*
248  * Cleanup after a directory scan
249  */
250 void
251 finishDosDirSection(void)
252 {
253 	struct dirTodoNode *p, *np;
254 	struct dosDirEntry *d, *nd;
255 
256 	for (p = pendingDirectories; p; p = np) {
257 		np = p->next;
258 		freeDirTodo(p);
259 	}
260 	pendingDirectories = 0;
261 	for (d = rootDir; d; d = nd) {
262 		if ((nd = d->child) != NULL) {
263 			d->child = 0;
264 			continue;
265 		}
266 		if (!(nd = d->next))
267 			nd = d->parent;
268 		freeDosDirEntry(d);
269 	}
270 	rootDir = lostDir = NULL;
271 	free(buffer);
272 	free(delbuf);
273 	buffer = NULL;
274 	delbuf = NULL;
275 }
276 
277 /*
278  * Delete directory entries between startcl, startoff and endcl, endoff.
279  */
280 static int
281 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
282        int startoff, cl_t endcl, int endoff, int notlast)
283 {
284 	u_char *s, *e;
285 	off_t off;
286 	int clsz = boot->SecPerClust * boot->BytesPerSec;
287 
288 	s = delbuf + startoff;
289 	e = delbuf + clsz;
290 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
291 		if (startcl == endcl) {
292 			if (notlast)
293 				break;
294 			e = delbuf + endoff;
295 		}
296 		off = startcl * boot->SecPerClust + boot->ClusterOffset;
297 		off *= boot->BytesPerSec;
298 		if (lseek(f, off, SEEK_SET) != off
299 		    || read(f, delbuf, clsz) != clsz) {
300 			xperror("Unable to read directory");
301 			return (FSFATAL);
302 		}
303 		while (s < e) {
304 			*s = SLOT_DELETED;
305 			s += 32;
306 		}
307 		if (lseek(f, off, SEEK_SET) != off
308 		    || write(f, delbuf, clsz) != clsz) {
309 			xperror("Unable to write directory");
310 			return (FSFATAL);
311 		}
312 		if (startcl == endcl)
313 			break;
314 		startcl = fat[startcl].next;
315 		s = delbuf;
316 	}
317 	return (FSOK);
318 }
319 
320 static int
321 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
322 	 u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
323 {
324 	switch (type) {
325 	case 0:
326 		pwarn("Invalid long filename entry for %s\n", path);
327 		break;
328 	case 1:
329 		pwarn("Invalid long filename entry at end of directory %s\n", path);
330 		break;
331 	case 2:
332 		pwarn("Invalid long filename entry for volume label\n");
333 		break;
334 	}
335 	if (ask(0, "Remove")) {
336 		if (startcl != curcl) {
337 			if (delete(f, boot, fat,
338 				   startcl, start - buffer,
339 				   endcl, end - buffer,
340 				   endcl == curcl) == FSFATAL)
341 				return (FSFATAL);
342 			start = buffer;
343 		}
344 		if (endcl == curcl)
345 			for (; start < end; start += 32)
346 				*start = SLOT_DELETED;
347 		return (FSDIRMOD);
348 	}
349 	return (FSERROR);
350 }
351 
352 /*
353  * Check an in-memory file entry
354  */
355 static int
356 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
357 	  struct dosDirEntry *dir)
358 {
359 	/*
360 	 * Check size on ordinary files
361 	 */
362 	u_int32_t physicalSize;
363 
364 	if (dir->head == CLUST_FREE)
365 		physicalSize = 0;
366 	else {
367 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
368 			return (FSERROR);
369 		physicalSize = fat[dir->head].length * boot->ClusterSize;
370 	}
371 	if (physicalSize < dir->size) {
372 		pwarn("size of %s is %u, should at most be %u\n",
373 		      fullpath(dir), dir->size, physicalSize);
374 		if (ask(1, "Truncate")) {
375 			dir->size = physicalSize;
376 			p[28] = (u_char)physicalSize;
377 			p[29] = (u_char)(physicalSize >> 8);
378 			p[30] = (u_char)(physicalSize >> 16);
379 			p[31] = (u_char)(physicalSize >> 24);
380 			return (FSDIRMOD);
381 		} else
382 			return (FSERROR);
383 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
384 		pwarn("%s has too many clusters allocated\n",
385 		      fullpath(dir));
386 		if (ask(1, "Drop superfluous clusters")) {
387 			cl_t cl;
388 			u_int32_t len, sz;
389 
390 			len = sz = 0;
391 			for (cl = dir->head; (sz += boot->ClusterSize) < dir->size;) {
392 				cl = fat[cl].next;
393 				len++;
394 			}
395 			clearchain(boot, fat, fat[cl].next);
396 			fat[cl].next = CLUST_EOF;
397 			fat[dir->head].length = len;
398 			return (FSFATMOD);
399 		} else
400 			return (FSERROR);
401 	}
402 	return (FSOK);
403 }
404 
405 /*
406  * Read a directory and
407  *   - resolve long name records
408  *   - enter file and directory records into the parent's list
409  *   - push directories onto the todo-stack
410  */
411 static int
412 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
413 		  struct dosDirEntry *dir)
414 {
415 	struct dosDirEntry dirent, *d;
416 	u_char *p, *vallfn, *invlfn, *empty;
417 	off_t off;
418 	int i, j, k, last;
419 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
420 	char *t;
421 	u_int lidx = 0;
422 	int shortSum;
423 	int mod = FSOK;
424 #define	THISMOD	0x8000			/* Only used within this routine */
425 
426 	cl = dir->head;
427 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
428 		/*
429 		 * Already handled somewhere else.
430 		 */
431 		return (FSOK);
432 	}
433 	shortSum = -1;
434 	vallfn = invlfn = empty = NULL;
435 	do {
436 		if (!(boot->flags & FAT32) && !dir->parent) {
437 			last = boot->RootDirEnts * 32;
438 			off = boot->ResSectors + boot->FATs * boot->FATsecs;
439 		} else {
440 			last = boot->SecPerClust * boot->BytesPerSec;
441 			off = cl * boot->SecPerClust + boot->ClusterOffset;
442 		}
443 
444 		off *= boot->BytesPerSec;
445 		if (lseek(f, off, SEEK_SET) != off
446 		    || read(f, buffer, last) != last) {
447 			xperror("Unable to read directory");
448 			return (FSFATAL);
449 		}
450 		last /= 32;
451 		/*
452 		 * Check `.' and `..' entries here?			XXX
453 		 */
454 		for (p = buffer, i = 0; i < last; i++, p += 32) {
455 			if (dir->fsckflags & DIREMPWARN) {
456 				*p = SLOT_EMPTY;
457 				continue;
458 			}
459 
460 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
461 				if (*p == SLOT_EMPTY) {
462 					dir->fsckflags |= DIREMPTY;
463 					empty = p;
464 					empcl = cl;
465 				}
466 				continue;
467 			}
468 
469 			if (dir->fsckflags & DIREMPTY) {
470 				if (!(dir->fsckflags & DIREMPWARN)) {
471 					pwarn("%s has entries after end of directory\n",
472 					      fullpath(dir));
473 					if (ask(1, "Extend")) {
474 						u_char *q;
475 
476 						dir->fsckflags &= ~DIREMPTY;
477 						if (delete(f, boot, fat,
478 							   empcl, empty - buffer,
479 							   cl, p - buffer, 1) == FSFATAL)
480 							return (FSFATAL);
481 						q = empcl == cl ? empty : buffer;
482 						for (; q < p; q += 32)
483 							*q = SLOT_DELETED;
484 						mod |= THISMOD|FSDIRMOD;
485 					} else if (ask(0, "Truncate"))
486 						dir->fsckflags |= DIREMPWARN;
487 				}
488 				if (dir->fsckflags & DIREMPWARN) {
489 					*p = SLOT_DELETED;
490 					mod |= THISMOD|FSDIRMOD;
491 					continue;
492 				} else if (dir->fsckflags & DIREMPTY)
493 					mod |= FSERROR;
494 				empty = NULL;
495 			}
496 
497 			if (p[11] == ATTR_WIN95) {
498 				if (*p & LRFIRST) {
499 					if (shortSum != -1) {
500 						if (!invlfn) {
501 							invlfn = vallfn;
502 							invcl = valcl;
503 						}
504 					}
505 					(void)memset(longName, 0, sizeof longName);
506 					shortSum = p[13];
507 					vallfn = p;
508 					valcl = cl;
509 				} else if (shortSum != p[13]
510 					   || lidx != (*p & LRNOMASK)) {
511 					if (!invlfn) {
512 						invlfn = vallfn;
513 						invcl = valcl;
514 					}
515 					if (!invlfn) {
516 						invlfn = p;
517 						invcl = cl;
518 					}
519 					vallfn = NULL;
520 				}
521 				lidx = *p & LRNOMASK;
522 				if (lidx == 0) {
523 					if (!invlfn) {
524 						invlfn = vallfn;
525 						invcl = valcl;
526 					}
527 					vallfn = NULL;
528 					continue;
529 				}
530 				t = longName + --lidx * 13;
531 				for (k = 1; k < 11 && t < longName + sizeof(longName); k += 2) {
532 					if (!p[k] && !p[k + 1])
533 						break;
534 					*t++ = p[k];
535 					/*
536 					 * Warn about those unusable chars in msdosfs here?	XXX
537 					 */
538 					if (p[k + 1])
539 						t[-1] = '?';
540 				}
541 				if (k >= 11)
542 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
543 						if (!p[k] && !p[k + 1])
544 							break;
545 						*t++ = p[k];
546 						if (p[k + 1])
547 							t[-1] = '?';
548 					}
549 				if (k >= 26)
550 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
551 						if (!p[k] && !p[k + 1])
552 							break;
553 						*t++ = p[k];
554 						if (p[k + 1])
555 							t[-1] = '?';
556 					}
557 				if (t >= longName + sizeof(longName)) {
558 					pwarn("long filename too long\n");
559 					if (!invlfn) {
560 						invlfn = vallfn;
561 						invcl = valcl;
562 					}
563 					vallfn = NULL;
564 				}
565 				if (p[26] | (p[27] << 8)) {
566 					pwarn("long filename record cluster start != 0\n");
567 					if (!invlfn) {
568 						invlfn = vallfn;
569 						invcl = cl;
570 					}
571 					vallfn = NULL;
572 				}
573 				continue;	/* long records don't carry further
574 						 * information */
575 			}
576 
577 			/*
578 			 * This is a standard msdosfs directory entry.
579 			 */
580 			(void)memset(&dirent, 0, sizeof dirent);
581 
582 			/*
583 			 * it's a short name record, but we need to know
584 			 * more, so get the flags first.
585 			 */
586 			dirent.flags = p[11];
587 
588 			/*
589 			 * Translate from 850 to ISO here		XXX
590 			 */
591 			for (j = 0; j < 8; j++)
592 				dirent.name[j] = p[j];
593 			dirent.name[8] = '\0';
594 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
595 				dirent.name[k] = '\0';
596 			if (dirent.name[k] != '\0')
597 				k++;
598 			if (dirent.name[0] == SLOT_E5)
599 				dirent.name[0] = 0xe5;
600 
601 			if (dirent.flags & ATTR_VOLUME) {
602 				if (vallfn || invlfn) {
603 					mod |= removede(f, boot, fat,
604 							invlfn ? invlfn : vallfn, p,
605 							invlfn ? invcl : valcl, -1, 0,
606 							fullpath(dir), 2);
607 					vallfn = NULL;
608 					invlfn = NULL;
609 				}
610 				continue;
611 			}
612 
613 			if (p[8] != ' ')
614 				dirent.name[k++] = '.';
615 			for (j = 0; j < 3; j++)
616 				dirent.name[k++] = p[j+8];
617 			dirent.name[k] = '\0';
618 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
619 				dirent.name[k] = '\0';
620 
621 			if (vallfn && shortSum != calcShortSum(p)) {
622 				if (!invlfn) {
623 					invlfn = vallfn;
624 					invcl = valcl;
625 				}
626 				vallfn = NULL;
627 			}
628 			dirent.head = p[26] | (p[27] << 8);
629 			if (boot->ClustMask == CLUST32_MASK)
630 				dirent.head |= (p[20] << 16) | (p[21] << 24);
631 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
632 			if (vallfn) {
633 				strlcpy(dirent.lname, longName, sizeof dirent.lname);
634 				longName[0] = '\0';
635 				shortSum = -1;
636 			}
637 
638 			dirent.parent = dir;
639 			dirent.next = dir->child;
640 
641 			if (invlfn) {
642 				mod |= k = removede(f, boot, fat,
643 						    invlfn, vallfn ? vallfn : p,
644 						    invcl, vallfn ? valcl : cl, cl,
645 						    fullpath(&dirent), 0);
646 				if (mod & FSFATAL)
647 					return (FSFATAL);
648 				if (vallfn
649 				    ? (valcl == cl && vallfn != buffer)
650 				    : p != buffer)
651 					if (k & FSDIRMOD)
652 						mod |= THISMOD;
653 			}
654 
655 			vallfn = NULL; /* not used any longer */
656 			invlfn = NULL;
657 
658 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
659 				if (dirent.head != 0) {
660 					pwarn("%s has clusters, but size 0\n",
661 					      fullpath(&dirent));
662 					if (ask(1, "Drop allocated clusters")) {
663 						p[26] = p[27] = 0;
664 						if (boot->ClustMask == CLUST32_MASK)
665 							p[20] = p[21] = 0;
666 						clearchain(boot, fat, dirent.head);
667 						dirent.head = 0;
668 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
669 					} else
670 						mod |= FSERROR;
671 				}
672 			} else if (dirent.head == 0
673 				   && !strcmp(dirent.name, "..")
674 				   && dir->parent			/* XXX */
675 				   && !dir->parent->parent) {
676 				/*
677 				 *  Do nothing, the parent is the root
678 				 */
679 			} else if (dirent.head < CLUST_FIRST
680 				   || dirent.head >= boot->NumClusters
681 				   || fat[dirent.head].next == CLUST_FREE
682 				   || (fat[dirent.head].next >= CLUST_RSRVD
683 				       && fat[dirent.head].next < CLUST_EOFS)
684 				   || fat[dirent.head].head != dirent.head) {
685 				if (dirent.head == 0)
686 					pwarn("%s has no clusters\n",
687 					      fullpath(&dirent));
688 				else if (dirent.head < CLUST_FIRST
689 					 || dirent.head >= boot->NumClusters)
690 					pwarn("%s starts with cluster out of range(%u)\n",
691 					      fullpath(&dirent),
692 					      dirent.head);
693 				else if (fat[dirent.head].next == CLUST_FREE)
694 					pwarn("%s starts with free cluster\n",
695 					      fullpath(&dirent));
696 				else if (fat[dirent.head].next >= CLUST_RSRVD)
697 					pwarn("%s starts with cluster marked %s\n",
698 					      fullpath(&dirent),
699 					      rsrvdcltype(fat[dirent.head].next));
700 				else
701 					pwarn("%s doesn't start a cluster chain\n",
702 					      fullpath(&dirent));
703 				if (dirent.flags & ATTR_DIRECTORY) {
704 					if (ask(0, "Remove")) {
705 						*p = SLOT_DELETED;
706 						mod |= THISMOD|FSDIRMOD;
707 					} else
708 						mod |= FSERROR;
709 					continue;
710 				} else {
711 					if (ask(1, "Truncate")) {
712 						p[28] = p[29] = p[30] = p[31] = 0;
713 						p[26] = p[27] = 0;
714 						if (boot->ClustMask == CLUST32_MASK)
715 							p[20] = p[21] = 0;
716 						dirent.size = 0;
717 						mod |= THISMOD|FSDIRMOD;
718 					} else
719 						mod |= FSERROR;
720 				}
721 			}
722 
723 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
724 				fat[dirent.head].flags |= FAT_USED;
725 
726 			if (dirent.flags & ATTR_DIRECTORY) {
727 				/*
728 				 * gather more info for directories
729 				 */
730 				struct dirTodoNode *n;
731 
732 				if (dirent.size) {
733 					pwarn("Directory %s has size != 0\n",
734 					      fullpath(&dirent));
735 					if (ask(1, "Correct")) {
736 						p[28] = p[29] = p[30] = p[31] = 0;
737 						dirent.size = 0;
738 						mod |= THISMOD|FSDIRMOD;
739 					} else
740 						mod |= FSERROR;
741 				}
742 				/*
743 				 * handle `.' and `..' specially
744 				 */
745 				if (strcmp(dirent.name, ".") == 0) {
746 					if (dirent.head != dir->head) {
747 						pwarn("`.' entry in %s has incorrect start cluster\n",
748 						      fullpath(dir));
749 						if (ask(1, "Correct")) {
750 							dirent.head = dir->head;
751 							p[26] = (u_char)dirent.head;
752 							p[27] = (u_char)(dirent.head >> 8);
753 							if (boot->ClustMask == CLUST32_MASK) {
754 								p[20] = (u_char)(dirent.head >> 16);
755 								p[21] = (u_char)(dirent.head >> 24);
756 							}
757 							mod |= THISMOD|FSDIRMOD;
758 						} else
759 							mod |= FSERROR;
760 					}
761 					continue;
762 				}
763 				if (strcmp(dirent.name, "..") == 0) {
764 					if (dir->parent) {		/* XXX */
765 						if (!dir->parent->parent) {
766 							if (dirent.head) {
767 								pwarn("`..' entry in %s has non-zero start cluster\n",
768 								      fullpath(dir));
769 								if (ask(1, "Correct")) {
770 									dirent.head = 0;
771 									p[26] = p[27] = 0;
772 									if (boot->ClustMask == CLUST32_MASK)
773 										p[20] = p[21] = 0;
774 									mod |= THISMOD|FSDIRMOD;
775 								} else
776 									mod |= FSERROR;
777 							}
778 						} else if (dirent.head != dir->parent->head) {
779 							pwarn("`..' entry in %s has incorrect start cluster\n",
780 							      fullpath(dir));
781 							if (ask(1, "Correct")) {
782 								dirent.head = dir->parent->head;
783 								p[26] = (u_char)dirent.head;
784 								p[27] = (u_char)(dirent.head >> 8);
785 								if (boot->ClustMask == CLUST32_MASK) {
786 									p[20] = (u_char)(dirent.head >> 16);
787 									p[21] = (u_char)(dirent.head >> 24);
788 								}
789 								mod |= THISMOD|FSDIRMOD;
790 							} else
791 								mod |= FSERROR;
792 						}
793 					}
794 					continue;
795 				}
796 
797 				/* create directory tree node */
798 				if (!(d = newDosDirEntry())) {
799 					xperror("No space for directory");
800 					return (FSFATAL);
801 				}
802 				(void)memcpy(d, &dirent, sizeof(struct dosDirEntry));
803 				/* link it into the tree */
804 				dir->child = d;
805 
806 				/* Enter this directory into the todo list */
807 				if (!(n = newDirTodo())) {
808 					xperror("No space for todo list");
809 					return (FSFATAL);
810 				}
811 				n->next = pendingDirectories;
812 				n->dir = d;
813 				pendingDirectories = n;
814 			} else {
815 				mod |= k = checksize(boot, fat, p, &dirent);
816 				if (k & FSDIRMOD)
817 					mod |= THISMOD;
818 			}
819 			boot->NumFiles++;
820 		}
821 		if (mod & THISMOD) {
822 			last *= 32;
823 			if (lseek(f, off, SEEK_SET) != off
824 			    || write(f, buffer, last) != last) {
825 				xperror("Unable to write directory");
826 				return (FSFATAL);
827 			}
828 			mod &= ~THISMOD;
829 		}
830 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
831 	if (invlfn || vallfn)
832 		mod |= removede(f, boot, fat,
833 				invlfn ? invlfn : vallfn, p,
834 				invlfn ? invcl : valcl, -1, 0,
835 				fullpath(dir), 1);
836 	return (mod & ~THISMOD);
837 }
838 
839 int
840 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
841 {
842 	int mod;
843 
844 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
845 	if (mod & FSFATAL)
846 		return (FSFATAL);
847 
848 	if (mod & FSFATMOD) {
849 		mod &= ~FSFATMOD;
850 		mod |= writefat(dosfs, boot, fat); /* delay writing fats?	XXX */
851 	}
852 
853 	if (mod & FSFATAL)
854 		return (FSFATAL);
855 
856 	/*
857 	 * process the directory todo list
858 	 */
859 	while (pendingDirectories) {
860 		struct dosDirEntry *dir = pendingDirectories->dir;
861 		struct dirTodoNode *n = pendingDirectories->next;
862 
863 		/*
864 		 * remove TODO entry now, the list might change during
865 		 * directory reads
866 		 */
867 		freeDirTodo(pendingDirectories);
868 		pendingDirectories = n;
869 
870 		/*
871 		 * handle subdirectory
872 		 */
873 		mod |= readDosDirSection(dosfs, boot, fat, dir);
874 		if (mod & FSFATAL)
875 			return (FSFATAL);
876 		if (mod & FSFATMOD) {
877 			mod &= ~FSFATMOD;
878 			mod |= writefat(dosfs, boot, fat); /* delay writing fats? XXX */
879 		}
880 		if (mod & FSFATAL)
881 			return (FSFATAL);
882 	}
883 	return (mod);
884 }
885 
886 /*
887  * Try to reconnect a FAT chain into dir
888  */
889 static u_char *lfbuf;
890 static cl_t lfcl;
891 static off_t lfoff;
892 
893 int
894 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
895 {
896 	struct dosDirEntry d;
897 	u_char *p;
898 
899 	if (!ask(1, "Reconnect"))
900 		return FSERROR;
901 
902 	if (!lostDir) {
903 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
904 			if (!strcmp(lostDir->name, LOSTDIR))
905 				break;
906 		}
907 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
908 			pwarn("No %s directory\n", LOSTDIR);
909 			return (FSERROR);
910 		}
911 	}
912 	if (!lfbuf) {
913 		lfbuf = malloc(boot->ClusterSize);
914 		if (!lfbuf) {
915 			xperror("No space for buffer");
916 			return (FSFATAL);
917 		}
918 		p = NULL;
919 	} else
920 		p = lfbuf;
921 	while (1) {
922 		if (p)
923 			for (; p < lfbuf + boot->ClusterSize; p += 32)
924 				if (*p == SLOT_EMPTY
925 				    || *p == SLOT_DELETED)
926 					break;
927 		if (p && p < lfbuf + boot->ClusterSize)
928 			break;
929 		lfcl = p ? fat[lfcl].next : lostDir->head;
930 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
931 			/* Extend LOSTDIR?				XXX */
932 			pwarn("No space in %s\n", LOSTDIR);
933 			return (FSERROR);
934 		}
935 		lfoff = lfcl * boot->ClusterSize
936 		    + boot->ClusterOffset * boot->BytesPerSec;
937 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
938 		    || read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
939 			xperror("could not read LOST.DIR");
940 			return (FSFATAL);
941 		}
942 		p = lfbuf;
943 	}
944 
945 	boot->NumFiles++;
946 	/* Ensure uniqueness of entry here!				XXX */
947 	(void)memset(&d, 0, sizeof d);
948 	snprintf(d.name, sizeof d.name, "%u", head);
949 	d.flags = 0;
950 	d.head = head;
951 	d.size = fat[head].length * boot->ClusterSize;
952 
953 	(void)memset(p, 0, 32);
954 	(void)memset(p, ' ', 11);
955 	(void)memcpy(p, d.name, strlen(d.name));
956 	p[26] = (u_char)d.head;
957 	p[27] = (u_char)(d.head >> 8);
958 	if (boot->ClustMask == CLUST32_MASK) {
959 		p[20] = (u_char)(d.head >> 16);
960 		p[21] = (u_char)(d.head >> 24);
961 	}
962 	p[28] = (u_char)d.size;
963 	p[29] = (u_char)(d.size >> 8);
964 	p[30] = (u_char)(d.size >> 16);
965 	p[31] = (u_char)(d.size >> 24);
966 	fat[head].flags |= FAT_USED;
967 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
968 	    || write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
969 		xperror("could not write LOST.DIR");
970 		return (FSFATAL);
971 	}
972 	return (FSDIRMOD);
973 }
974 
975 void
976 finishlf(void)
977 {
978 	if (lfbuf)
979 		free(lfbuf);
980 	lfbuf = NULL;
981 }
982