xref: /freebsd/sbin/fsck_msdosfs/dir.c (revision 9cdd5c07ad924249d620437d00458c3b6434dbe5)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
5  * Copyright (c) 1995 Martin Husemann
6  * Some structure declaration borrowed from Paul Popelka
7  * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 
31 #include <sys/cdefs.h>
32 #ifndef lint
33 __RCSID("$NetBSD: dir.c,v 1.20 2006/06/05 16:51:18 christos Exp $");
34 static const char rcsid[] =
35   "$FreeBSD$";
36 #endif /* not lint */
37 
38 #include <assert.h>
39 #include <inttypes.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <ctype.h>
44 #include <unistd.h>
45 #include <time.h>
46 
47 #include <sys/param.h>
48 
49 #include "ext.h"
50 #include "fsutil.h"
51 
52 #define	SLOT_EMPTY	0x00		/* slot has never been used */
53 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
54 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
55 
56 #define	ATTR_NORMAL	0x00		/* normal file */
57 #define	ATTR_READONLY	0x01		/* file is readonly */
58 #define	ATTR_HIDDEN	0x02		/* file is hidden */
59 #define	ATTR_SYSTEM	0x04		/* file is a system file */
60 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
61 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
62 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
63 
64 #define	ATTR_WIN95	0x0f		/* long name record */
65 
66 /*
67  * This is the format of the contents of the deTime field in the direntry
68  * structure.
69  * We don't use bitfields because we don't know how compilers for
70  * arbitrary machines will lay them out.
71  */
72 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
73 #define DT_2SECONDS_SHIFT	0
74 #define DT_MINUTES_MASK		0x7E0	/* minutes */
75 #define DT_MINUTES_SHIFT	5
76 #define DT_HOURS_MASK		0xF800	/* hours */
77 #define DT_HOURS_SHIFT		11
78 
79 /*
80  * This is the format of the contents of the deDate field in the direntry
81  * structure.
82  */
83 #define DD_DAY_MASK		0x1F	/* day of month */
84 #define DD_DAY_SHIFT		0
85 #define DD_MONTH_MASK		0x1E0	/* month */
86 #define DD_MONTH_SHIFT		5
87 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
88 #define DD_YEAR_SHIFT		9
89 
90 
91 /* dir.c */
92 static struct dosDirEntry *newDosDirEntry(void);
93 static void freeDosDirEntry(struct dosDirEntry *);
94 static struct dirTodoNode *newDirTodo(void);
95 static void freeDirTodo(struct dirTodoNode *);
96 static char *fullpath(struct dosDirEntry *);
97 static u_char calcShortSum(u_char *);
98 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
99     cl_t, int, int);
100 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
101     u_char *, cl_t, cl_t, cl_t, char *, int);
102 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
103     struct dosDirEntry *);
104 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
105     struct dosDirEntry *);
106 
107 /*
108  * Manage free dosDirEntry structures.
109  */
110 static struct dosDirEntry *freede;
111 
112 static struct dosDirEntry *
113 newDosDirEntry(void)
114 {
115 	struct dosDirEntry *de;
116 
117 	if (!(de = freede)) {
118 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
119 			return 0;
120 	} else
121 		freede = de->next;
122 	return de;
123 }
124 
125 static void
126 freeDosDirEntry(struct dosDirEntry *de)
127 {
128 	de->next = freede;
129 	freede = de;
130 }
131 
132 /*
133  * The same for dirTodoNode structures.
134  */
135 static struct dirTodoNode *freedt;
136 
137 static struct dirTodoNode *
138 newDirTodo(void)
139 {
140 	struct dirTodoNode *dt;
141 
142 	if (!(dt = freedt)) {
143 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
144 			return 0;
145 	} else
146 		freedt = dt->next;
147 	return dt;
148 }
149 
150 static void
151 freeDirTodo(struct dirTodoNode *dt)
152 {
153 	dt->next = freedt;
154 	freedt = dt;
155 }
156 
157 /*
158  * The stack of unread directories
159  */
160 static struct dirTodoNode *pendingDirectories = NULL;
161 
162 /*
163  * Return the full pathname for a directory entry.
164  */
165 static char *
166 fullpath(struct dosDirEntry *dir)
167 {
168 	static char namebuf[MAXPATHLEN + 1];
169 	char *cp, *np;
170 	int nl;
171 
172 	cp = namebuf + sizeof namebuf - 1;
173 	*cp = '\0';
174 	do {
175 		np = dir->lname[0] ? dir->lname : dir->name;
176 		nl = strlen(np);
177 		if ((cp -= nl) <= namebuf + 1)
178 			break;
179 		memcpy(cp, np, nl);
180 		*--cp = '/';
181 	} while ((dir = dir->parent) != NULL);
182 	if (dir)
183 		*--cp = '?';
184 	else
185 		cp++;
186 	return cp;
187 }
188 
189 /*
190  * Calculate a checksum over an 8.3 alias name
191  */
192 static u_char
193 calcShortSum(u_char *p)
194 {
195 	u_char sum = 0;
196 	int i;
197 
198 	for (i = 0; i < 11; i++) {
199 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
200 		sum += p[i];
201 	}
202 
203 	return sum;
204 }
205 
206 /*
207  * Global variables temporarily used during a directory scan
208  */
209 static char longName[DOSLONGNAMELEN] = "";
210 static u_char *buffer = NULL;
211 static u_char *delbuf = NULL;
212 
213 static struct dosDirEntry *rootDir;
214 static struct dosDirEntry *lostDir;
215 
216 /*
217  * Init internal state for a new directory scan.
218  */
219 int
220 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
221 {
222 	int b1, b2;
223 	cl_t cl;
224 	int ret = FSOK;
225 	size_t len;
226 
227 	b1 = boot->bpbRootDirEnts * 32;
228 	b2 = boot->bpbSecPerClust * boot->bpbBytesPerSec;
229 
230 	if ((buffer = malloc(len = MAX(b1, b2))) == NULL) {
231 		perr("No space for directory buffer (%zu)", len);
232 		return FSFATAL;
233 	}
234 
235 	if ((delbuf = malloc(len = b2)) == NULL) {
236 		free(buffer);
237 		perr("No space for directory delbuf (%zu)", len);
238 		return FSFATAL;
239 	}
240 
241 	if ((rootDir = newDosDirEntry()) == NULL) {
242 		free(buffer);
243 		free(delbuf);
244 		perr("No space for directory entry");
245 		return FSFATAL;
246 	}
247 
248 	memset(rootDir, 0, sizeof *rootDir);
249 	if (boot->flags & FAT32) {
250 		if (boot->bpbRootClust < CLUST_FIRST ||
251 		    boot->bpbRootClust >= boot->NumClusters) {
252 			pfatal("Root directory starts with cluster out of range(%u)",
253 			       boot->bpbRootClust);
254 			return FSFATAL;
255 		}
256 		cl = fat[boot->bpbRootClust].next;
257 		if (cl < CLUST_FIRST
258 		    || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
259 		    || fat[boot->bpbRootClust].head != boot->bpbRootClust) {
260 			if (cl == CLUST_FREE)
261 				pwarn("Root directory starts with free cluster\n");
262 			else if (cl >= CLUST_RSRVD)
263 				pwarn("Root directory starts with cluster marked %s\n",
264 				      rsrvdcltype(cl));
265 			else {
266 				pfatal("Root directory doesn't start a cluster chain");
267 				return FSFATAL;
268 			}
269 			if (ask(1, "Fix")) {
270 				fat[boot->bpbRootClust].next = CLUST_FREE;
271 				ret = FSFATMOD;
272 			} else
273 				ret = FSFATAL;
274 		}
275 
276 		fat[boot->bpbRootClust].flags |= FAT_USED;
277 		rootDir->head = boot->bpbRootClust;
278 	}
279 
280 	return ret;
281 }
282 
283 /*
284  * Cleanup after a directory scan
285  */
286 void
287 finishDosDirSection(void)
288 {
289 	struct dirTodoNode *p, *np;
290 	struct dosDirEntry *d, *nd;
291 
292 	for (p = pendingDirectories; p; p = np) {
293 		np = p->next;
294 		freeDirTodo(p);
295 	}
296 	pendingDirectories = NULL;
297 	for (d = rootDir; d; d = nd) {
298 		if ((nd = d->child) != NULL) {
299 			d->child = 0;
300 			continue;
301 		}
302 		if (!(nd = d->next))
303 			nd = d->parent;
304 		freeDosDirEntry(d);
305 	}
306 	rootDir = lostDir = NULL;
307 	free(buffer);
308 	free(delbuf);
309 	buffer = NULL;
310 	delbuf = NULL;
311 }
312 
313 /*
314  * Delete directory entries between startcl, startoff and endcl, endoff.
315  */
316 static int
317 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
318     int startoff, cl_t endcl, int endoff, int notlast)
319 {
320 	u_char *s, *e;
321 	off_t off;
322 	int clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
323 
324 	s = delbuf + startoff;
325 	e = delbuf + clsz;
326 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
327 		if (startcl == endcl) {
328 			if (notlast)
329 				break;
330 			e = delbuf + endoff;
331 		}
332 		off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
333 		off *= boot->bpbBytesPerSec;
334 		if (lseek(f, off, SEEK_SET) != off) {
335 			perr("Unable to lseek to %" PRId64, off);
336 			return FSFATAL;
337 		}
338 		if (read(f, delbuf, clsz) != clsz) {
339 			perr("Unable to read directory");
340 			return FSFATAL;
341 		}
342 		while (s < e) {
343 			*s = SLOT_DELETED;
344 			s += 32;
345 		}
346 		if (lseek(f, off, SEEK_SET) != off) {
347 			perr("Unable to lseek to %" PRId64, off);
348 			return FSFATAL;
349 		}
350 		if (write(f, delbuf, clsz) != clsz) {
351 			perr("Unable to write directory");
352 			return FSFATAL;
353 		}
354 		if (startcl == endcl)
355 			break;
356 		startcl = fat[startcl].next;
357 		s = delbuf;
358 	}
359 	return FSOK;
360 }
361 
362 static int
363 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
364     u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
365 {
366 	switch (type) {
367 	case 0:
368 		pwarn("Invalid long filename entry for %s\n", path);
369 		break;
370 	case 1:
371 		pwarn("Invalid long filename entry at end of directory %s\n",
372 		    path);
373 		break;
374 	case 2:
375 		pwarn("Invalid long filename entry for volume label\n");
376 		break;
377 	}
378 	if (ask(0, "Remove")) {
379 		if (startcl != curcl) {
380 			if (delete(f, boot, fat,
381 				   startcl, start - buffer,
382 				   endcl, end - buffer,
383 				   endcl == curcl) == FSFATAL)
384 				return FSFATAL;
385 			start = buffer;
386 		}
387 		/* startcl is < CLUST_FIRST for !fat32 root */
388 		if ((endcl == curcl) || (startcl < CLUST_FIRST))
389 			for (; start < end; start += 32)
390 				*start = SLOT_DELETED;
391 		return FSDIRMOD;
392 	}
393 	return FSERROR;
394 }
395 
396 /*
397  * Check an in-memory file entry
398  */
399 static int
400 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
401     struct dosDirEntry *dir)
402 {
403 	/*
404 	 * Check size on ordinary files
405 	 */
406 	u_int32_t physicalSize;
407 
408 	if (dir->head == CLUST_FREE)
409 		physicalSize = 0;
410 	else {
411 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
412 			return FSERROR;
413 		physicalSize = fat[dir->head].length * boot->ClusterSize;
414 	}
415 	if (physicalSize < dir->size) {
416 		pwarn("size of %s is %u, should at most be %u\n",
417 		      fullpath(dir), dir->size, physicalSize);
418 		if (ask(1, "Truncate")) {
419 			dir->size = physicalSize;
420 			p[28] = (u_char)physicalSize;
421 			p[29] = (u_char)(physicalSize >> 8);
422 			p[30] = (u_char)(physicalSize >> 16);
423 			p[31] = (u_char)(physicalSize >> 24);
424 			return FSDIRMOD;
425 		} else
426 			return FSERROR;
427 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
428 		pwarn("%s has too many clusters allocated\n",
429 		      fullpath(dir));
430 		if (ask(1, "Drop superfluous clusters")) {
431 			cl_t cl;
432 			u_int32_t sz, len;
433 
434 			for (cl = dir->head, len = sz = 0;
435 			    (sz += boot->ClusterSize) < dir->size; len++)
436 				cl = fat[cl].next;
437 			clearchain(boot, fat, fat[cl].next);
438 			fat[cl].next = CLUST_EOF;
439 			fat[dir->head].length = len;
440 			return FSFATMOD;
441 		} else
442 			return FSERROR;
443 	}
444 	return FSOK;
445 }
446 
447 static const u_char dot_name[] = {
448 	'.', ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' };
449 static const u_char dotdot_name[] = {
450 	'.', '.',' ',' ',' ',' ',' ',' ',' ',' ',' ' };
451 
452 /*
453  * Basic sanity check if the subdirectory have good '.' and '..' entries,
454  * and they are directory entries.  Further sanity checks are performed
455  * when we traverse into it.
456  */
457 static int
458 check_subdirectory(int f, struct bootblock *boot, struct dosDirEntry *dir)
459 {
460 	u_char *buf, *cp;
461 	off_t off;
462 	cl_t cl;
463 	int retval = FSOK;
464 
465 	cl = dir->head;
466 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
467 		return FSERROR;
468 	}
469 
470 	if (!(boot->flags & FAT32) && !dir->parent) {
471 		off = boot->bpbResSectors + boot->bpbFATs *
472 			boot->FATsecs;
473 	} else {
474 		off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
475 	}
476 
477 	/*
478 	 * We only need to check the first two entries of the directory,
479 	 * which is found in the first sector of the directory entry,
480 	 * so read in only the first sector.
481 	 */
482 	buf = malloc(boot->bpbBytesPerSec);
483 	if (buf == NULL) {
484 		perr("No space for directory buffer (%u)",
485 		    boot->bpbBytesPerSec);
486 		return FSFATAL;
487 	}
488 
489 	off *= boot->bpbBytesPerSec;
490 	if (lseek(f, off, SEEK_SET) != off ||
491 	    read(f, buf, boot->bpbBytesPerSec) != (ssize_t)boot->bpbBytesPerSec) {
492 		perr("Unable to read directory");
493 		free(buf);
494 		return FSFATAL;
495 	}
496 
497 	/*
498 	 * Both `.' and `..' must be present and be the first two entries
499 	 * and be ATTR_DIRECTORY of a valid subdirectory.
500 	 */
501 	cp = buf;
502 	if (memcmp(cp, dot_name, sizeof(dot_name)) != 0 ||
503 	    (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) {
504 		pwarn("%s: Incorrect `.' for %s.\n", __func__, dir->name);
505 		retval |= FSERROR;
506 	}
507 	cp += 32;
508 	if (memcmp(cp, dotdot_name, sizeof(dotdot_name)) != 0 ||
509 	    (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) {
510 		pwarn("%s: Incorrect `..' for %s. \n", __func__, dir->name);
511 		retval |= FSERROR;
512 	}
513 
514 	free(buf);
515 	return retval;
516 }
517 
518 /*
519  * Read a directory and
520  *   - resolve long name records
521  *   - enter file and directory records into the parent's list
522  *   - push directories onto the todo-stack
523  */
524 static int
525 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
526     struct dosDirEntry *dir)
527 {
528 	struct dosDirEntry dirent, *d;
529 	u_char *p, *vallfn, *invlfn, *empty;
530 	off_t off;
531 	int i, j, k, last;
532 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
533 	char *t;
534 	u_int lidx = 0;
535 	int shortSum;
536 	int mod = FSOK;
537 #define	THISMOD	0x8000			/* Only used within this routine */
538 
539 	cl = dir->head;
540 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
541 		/*
542 		 * Already handled somewhere else.
543 		 */
544 		return FSOK;
545 	}
546 	shortSum = -1;
547 	vallfn = invlfn = empty = NULL;
548 	do {
549 		if (!(boot->flags & FAT32) && !dir->parent) {
550 			last = boot->bpbRootDirEnts * 32;
551 			off = boot->bpbResSectors + boot->bpbFATs *
552 			    boot->FATsecs;
553 		} else {
554 			last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
555 			off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
556 		}
557 
558 		off *= boot->bpbBytesPerSec;
559 		if (lseek(f, off, SEEK_SET) != off
560 		    || read(f, buffer, last) != last) {
561 			perr("Unable to read directory");
562 			return FSFATAL;
563 		}
564 		last /= 32;
565 		for (p = buffer, i = 0; i < last; i++, p += 32) {
566 			if (dir->fsckflags & DIREMPWARN) {
567 				*p = SLOT_EMPTY;
568 				continue;
569 			}
570 
571 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
572 				if (*p == SLOT_EMPTY) {
573 					dir->fsckflags |= DIREMPTY;
574 					empty = p;
575 					empcl = cl;
576 				}
577 				continue;
578 			}
579 
580 			if (dir->fsckflags & DIREMPTY) {
581 				if (!(dir->fsckflags & DIREMPWARN)) {
582 					pwarn("%s has entries after end of directory\n",
583 					      fullpath(dir));
584 					if (ask(1, "Extend")) {
585 						u_char *q;
586 
587 						dir->fsckflags &= ~DIREMPTY;
588 						if (delete(f, boot, fat,
589 							   empcl, empty - buffer,
590 							   cl, p - buffer, 1) == FSFATAL)
591 							return FSFATAL;
592 						q = ((empcl == cl) ? empty : buffer);
593 						assert(q != NULL);
594 						for (; q < p; q += 32)
595 							*q = SLOT_DELETED;
596 						mod |= THISMOD|FSDIRMOD;
597 					} else if (ask(0, "Truncate"))
598 						dir->fsckflags |= DIREMPWARN;
599 				}
600 				if (dir->fsckflags & DIREMPWARN) {
601 					*p = SLOT_DELETED;
602 					mod |= THISMOD|FSDIRMOD;
603 					continue;
604 				} else if (dir->fsckflags & DIREMPTY)
605 					mod |= FSERROR;
606 				empty = NULL;
607 			}
608 
609 			if (p[11] == ATTR_WIN95) {
610 				if (*p & LRFIRST) {
611 					if (shortSum != -1) {
612 						if (!invlfn) {
613 							invlfn = vallfn;
614 							invcl = valcl;
615 						}
616 					}
617 					memset(longName, 0, sizeof longName);
618 					shortSum = p[13];
619 					vallfn = p;
620 					valcl = cl;
621 				} else if (shortSum != p[13]
622 					   || lidx != (*p & LRNOMASK)) {
623 					if (!invlfn) {
624 						invlfn = vallfn;
625 						invcl = valcl;
626 					}
627 					if (!invlfn) {
628 						invlfn = p;
629 						invcl = cl;
630 					}
631 					vallfn = NULL;
632 				}
633 				lidx = *p & LRNOMASK;
634 				t = longName + --lidx * 13;
635 				for (k = 1; k < 11 && t < longName +
636 				    sizeof(longName); k += 2) {
637 					if (!p[k] && !p[k + 1])
638 						break;
639 					*t++ = p[k];
640 					/*
641 					 * Warn about those unusable chars in msdosfs here?	XXX
642 					 */
643 					if (p[k + 1])
644 						t[-1] = '?';
645 				}
646 				if (k >= 11)
647 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
648 						if (!p[k] && !p[k + 1])
649 							break;
650 						*t++ = p[k];
651 						if (p[k + 1])
652 							t[-1] = '?';
653 					}
654 				if (k >= 26)
655 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
656 						if (!p[k] && !p[k + 1])
657 							break;
658 						*t++ = p[k];
659 						if (p[k + 1])
660 							t[-1] = '?';
661 					}
662 				if (t >= longName + sizeof(longName)) {
663 					pwarn("long filename too long\n");
664 					if (!invlfn) {
665 						invlfn = vallfn;
666 						invcl = valcl;
667 					}
668 					vallfn = NULL;
669 				}
670 				if (p[26] | (p[27] << 8)) {
671 					pwarn("long filename record cluster start != 0\n");
672 					if (!invlfn) {
673 						invlfn = vallfn;
674 						invcl = cl;
675 					}
676 					vallfn = NULL;
677 				}
678 				continue;	/* long records don't carry further
679 						 * information */
680 			}
681 
682 			/*
683 			 * This is a standard msdosfs directory entry.
684 			 */
685 			memset(&dirent, 0, sizeof dirent);
686 
687 			/*
688 			 * it's a short name record, but we need to know
689 			 * more, so get the flags first.
690 			 */
691 			dirent.flags = p[11];
692 
693 			/*
694 			 * Translate from 850 to ISO here		XXX
695 			 */
696 			for (j = 0; j < 8; j++)
697 				dirent.name[j] = p[j];
698 			dirent.name[8] = '\0';
699 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
700 				dirent.name[k] = '\0';
701 			if (k < 0 || dirent.name[k] != '\0')
702 				k++;
703 			if (dirent.name[0] == SLOT_E5)
704 				dirent.name[0] = 0xe5;
705 
706 			if (dirent.flags & ATTR_VOLUME) {
707 				if (vallfn || invlfn) {
708 					mod |= removede(f, boot, fat,
709 							invlfn ? invlfn : vallfn, p,
710 							invlfn ? invcl : valcl, -1, 0,
711 							fullpath(dir), 2);
712 					vallfn = NULL;
713 					invlfn = NULL;
714 				}
715 				continue;
716 			}
717 
718 			if (p[8] != ' ')
719 				dirent.name[k++] = '.';
720 			for (j = 0; j < 3; j++)
721 				dirent.name[k++] = p[j+8];
722 			dirent.name[k] = '\0';
723 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
724 				dirent.name[k] = '\0';
725 
726 			if (vallfn && shortSum != calcShortSum(p)) {
727 				if (!invlfn) {
728 					invlfn = vallfn;
729 					invcl = valcl;
730 				}
731 				vallfn = NULL;
732 			}
733 			dirent.head = p[26] | (p[27] << 8);
734 			if (boot->ClustMask == CLUST32_MASK)
735 				dirent.head |= (p[20] << 16) | (p[21] << 24);
736 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
737 			if (vallfn) {
738 				strlcpy(dirent.lname, longName,
739 				    sizeof(dirent.lname));
740 				longName[0] = '\0';
741 				shortSum = -1;
742 			}
743 
744 			dirent.parent = dir;
745 			dirent.next = dir->child;
746 
747 			if (invlfn) {
748 				mod |= k = removede(f, boot, fat,
749 						    invlfn, vallfn ? vallfn : p,
750 						    invcl, vallfn ? valcl : cl, cl,
751 						    fullpath(&dirent), 0);
752 				if (mod & FSFATAL)
753 					return FSFATAL;
754 				if (vallfn
755 				    ? (valcl == cl && vallfn != buffer)
756 				    : p != buffer)
757 					if (k & FSDIRMOD)
758 						mod |= THISMOD;
759 			}
760 
761 			vallfn = NULL; /* not used any longer */
762 			invlfn = NULL;
763 
764 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
765 				if (dirent.head != 0) {
766 					pwarn("%s has clusters, but size 0\n",
767 					      fullpath(&dirent));
768 					if (ask(1, "Drop allocated clusters")) {
769 						p[26] = p[27] = 0;
770 						if (boot->ClustMask == CLUST32_MASK)
771 							p[20] = p[21] = 0;
772 						clearchain(boot, fat, dirent.head);
773 						dirent.head = 0;
774 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
775 					} else
776 						mod |= FSERROR;
777 				}
778 			} else if (dirent.head == 0
779 				   && !strcmp(dirent.name, "..")
780 				   && dir->parent			/* XXX */
781 				   && !dir->parent->parent) {
782 				/*
783 				 *  Do nothing, the parent is the root
784 				 */
785 			} else if (dirent.head < CLUST_FIRST
786 				   || dirent.head >= boot->NumClusters
787 				   || fat[dirent.head].next == CLUST_FREE
788 				   || (fat[dirent.head].next >= CLUST_RSRVD
789 				       && fat[dirent.head].next < CLUST_EOFS)
790 				   || fat[dirent.head].head != dirent.head) {
791 				if (dirent.head == 0)
792 					pwarn("%s has no clusters\n",
793 					      fullpath(&dirent));
794 				else if (dirent.head < CLUST_FIRST
795 					 || dirent.head >= boot->NumClusters)
796 					pwarn("%s starts with cluster out of range(%u)\n",
797 					      fullpath(&dirent),
798 					      dirent.head);
799 				else if (fat[dirent.head].next == CLUST_FREE)
800 					pwarn("%s starts with free cluster\n",
801 					      fullpath(&dirent));
802 				else if (fat[dirent.head].next >= CLUST_RSRVD)
803 					pwarn("%s starts with cluster marked %s\n",
804 					      fullpath(&dirent),
805 					      rsrvdcltype(fat[dirent.head].next));
806 				else
807 					pwarn("%s doesn't start a cluster chain\n",
808 					      fullpath(&dirent));
809 				if (dirent.flags & ATTR_DIRECTORY) {
810 					if (ask(0, "Remove")) {
811 						*p = SLOT_DELETED;
812 						mod |= THISMOD|FSDIRMOD;
813 					} else
814 						mod |= FSERROR;
815 					continue;
816 				} else {
817 					if (ask(1, "Truncate")) {
818 						p[28] = p[29] = p[30] = p[31] = 0;
819 						p[26] = p[27] = 0;
820 						if (boot->ClustMask == CLUST32_MASK)
821 							p[20] = p[21] = 0;
822 						dirent.size = 0;
823 						mod |= THISMOD|FSDIRMOD;
824 					} else
825 						mod |= FSERROR;
826 				}
827 			}
828 
829 			if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
830 				fat[dirent.head].flags |= FAT_USED;
831 
832 			if (dirent.flags & ATTR_DIRECTORY) {
833 				/*
834 				 * gather more info for directories
835 				 */
836 				struct dirTodoNode *n;
837 
838 				if (dirent.size) {
839 					pwarn("Directory %s has size != 0\n",
840 					      fullpath(&dirent));
841 					if (ask(1, "Correct")) {
842 						p[28] = p[29] = p[30] = p[31] = 0;
843 						dirent.size = 0;
844 						mod |= THISMOD|FSDIRMOD;
845 					} else
846 						mod |= FSERROR;
847 				}
848 				/*
849 				 * handle `.' and `..' specially
850 				 */
851 				if (strcmp(dirent.name, ".") == 0) {
852 					if (dirent.head != dir->head) {
853 						pwarn("`.' entry in %s has incorrect start cluster\n",
854 						      fullpath(dir));
855 						if (ask(1, "Correct")) {
856 							dirent.head = dir->head;
857 							p[26] = (u_char)dirent.head;
858 							p[27] = (u_char)(dirent.head >> 8);
859 							if (boot->ClustMask == CLUST32_MASK) {
860 								p[20] = (u_char)(dirent.head >> 16);
861 								p[21] = (u_char)(dirent.head >> 24);
862 							}
863 							mod |= THISMOD|FSDIRMOD;
864 						} else
865 							mod |= FSERROR;
866 					}
867 					continue;
868 				}
869 				if (strcmp(dirent.name, "..") == 0) {
870 					if (dir->parent) {		/* XXX */
871 						if (!dir->parent->parent) {
872 							if (dirent.head) {
873 								pwarn("`..' entry in %s has non-zero start cluster\n",
874 								      fullpath(dir));
875 								if (ask(1, "Correct")) {
876 									dirent.head = 0;
877 									p[26] = p[27] = 0;
878 									if (boot->ClustMask == CLUST32_MASK)
879 										p[20] = p[21] = 0;
880 									mod |= THISMOD|FSDIRMOD;
881 								} else
882 									mod |= FSERROR;
883 							}
884 						} else if (dirent.head != dir->parent->head) {
885 							pwarn("`..' entry in %s has incorrect start cluster\n",
886 							      fullpath(dir));
887 							if (ask(1, "Correct")) {
888 								dirent.head = dir->parent->head;
889 								p[26] = (u_char)dirent.head;
890 								p[27] = (u_char)(dirent.head >> 8);
891 								if (boot->ClustMask == CLUST32_MASK) {
892 									p[20] = (u_char)(dirent.head >> 16);
893 									p[21] = (u_char)(dirent.head >> 24);
894 								}
895 								mod |= THISMOD|FSDIRMOD;
896 							} else
897 								mod |= FSERROR;
898 						}
899 					}
900 					continue;
901 				} else {
902 					/*
903 					 * Only one directory entry can point
904 					 * to dir->head, it's '.'.
905 					 */
906 					if (dirent.head == dir->head) {
907 						pwarn("%s entry in %s has incorrect start cluster\n",
908 								dirent.name, fullpath(dir));
909 						if (ask(1, "Remove")) {
910 							*p = SLOT_DELETED;
911 							mod |= THISMOD|FSDIRMOD;
912 						} else
913 							mod |= FSERROR;
914 						continue;
915 					} else if ((check_subdirectory(f, boot,
916 					    &dirent) & FSERROR) == FSERROR) {
917 						/*
918 						 * A subdirectory should have
919 						 * a dot (.) entry and a dot-dot
920 						 * (..) entry of ATTR_DIRECTORY,
921 						 * we will inspect further when
922 						 * traversing into it.
923 						 */
924 						if (ask(1, "Remove")) {
925 							*p = SLOT_DELETED;
926 							mod |= THISMOD|FSDIRMOD;
927 						} else
928 							mod |= FSERROR;
929 						continue;
930 					}
931 				}
932 
933 				/* create directory tree node */
934 				if (!(d = newDosDirEntry())) {
935 					perr("No space for directory");
936 					return FSFATAL;
937 				}
938 				memcpy(d, &dirent, sizeof(struct dosDirEntry));
939 				/* link it into the tree */
940 				dir->child = d;
941 
942 				/* Enter this directory into the todo list */
943 				if (!(n = newDirTodo())) {
944 					perr("No space for todo list");
945 					return FSFATAL;
946 				}
947 				n->next = pendingDirectories;
948 				n->dir = d;
949 				pendingDirectories = n;
950 			} else {
951 				mod |= k = checksize(boot, fat, p, &dirent);
952 				if (k & FSDIRMOD)
953 					mod |= THISMOD;
954 			}
955 			boot->NumFiles++;
956 		}
957 
958 		if (!(boot->flags & FAT32) && !dir->parent)
959 			break;
960 
961 		if (mod & THISMOD) {
962 			last *= 32;
963 			if (lseek(f, off, SEEK_SET) != off
964 			    || write(f, buffer, last) != last) {
965 				perr("Unable to write directory");
966 				return FSFATAL;
967 			}
968 			mod &= ~THISMOD;
969 		}
970 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
971 	if (invlfn || vallfn)
972 		mod |= removede(f, boot, fat,
973 				invlfn ? invlfn : vallfn, p,
974 				invlfn ? invcl : valcl, -1, 0,
975 				fullpath(dir), 1);
976 
977 	/* The root directory of non fat32 filesystems is in a special
978 	 * area and may have been modified above without being written out.
979 	 */
980 	if ((mod & FSDIRMOD) && !(boot->flags & FAT32) && !dir->parent) {
981 		last *= 32;
982 		if (lseek(f, off, SEEK_SET) != off
983 		    || write(f, buffer, last) != last) {
984 			perr("Unable to write directory");
985 			return FSFATAL;
986 		}
987 		mod &= ~THISMOD;
988 	}
989 	return mod & ~THISMOD;
990 }
991 
992 int
993 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
994 {
995 	int mod;
996 
997 	mod = readDosDirSection(dosfs, boot, fat, rootDir);
998 	if (mod & FSFATAL)
999 		return FSFATAL;
1000 
1001 	/*
1002 	 * process the directory todo list
1003 	 */
1004 	while (pendingDirectories) {
1005 		struct dosDirEntry *dir = pendingDirectories->dir;
1006 		struct dirTodoNode *n = pendingDirectories->next;
1007 
1008 		/*
1009 		 * remove TODO entry now, the list might change during
1010 		 * directory reads
1011 		 */
1012 		freeDirTodo(pendingDirectories);
1013 		pendingDirectories = n;
1014 
1015 		/*
1016 		 * handle subdirectory
1017 		 */
1018 		mod |= readDosDirSection(dosfs, boot, fat, dir);
1019 		if (mod & FSFATAL)
1020 			return FSFATAL;
1021 	}
1022 
1023 	return mod;
1024 }
1025 
1026 /*
1027  * Try to reconnect a FAT chain into dir
1028  */
1029 static u_char *lfbuf;
1030 static cl_t lfcl;
1031 static off_t lfoff;
1032 
1033 int
1034 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
1035 {
1036 	struct dosDirEntry d;
1037 	int len;
1038 	u_char *p;
1039 
1040 	if (!ask(1, "Reconnect"))
1041 		return FSERROR;
1042 
1043 	if (!lostDir) {
1044 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
1045 			if (!strcmp(lostDir->name, LOSTDIR))
1046 				break;
1047 		}
1048 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
1049 			pwarn("No %s directory\n", LOSTDIR);
1050 			return FSERROR;
1051 		}
1052 	}
1053 	if (!lfbuf) {
1054 		lfbuf = malloc(boot->ClusterSize);
1055 		if (!lfbuf) {
1056 			perr("No space for buffer");
1057 			return FSFATAL;
1058 		}
1059 		p = NULL;
1060 	} else
1061 		p = lfbuf;
1062 	while (1) {
1063 		if (p)
1064 			for (; p < lfbuf + boot->ClusterSize; p += 32)
1065 				if (*p == SLOT_EMPTY
1066 				    || *p == SLOT_DELETED)
1067 					break;
1068 		if (p && p < lfbuf + boot->ClusterSize)
1069 			break;
1070 		lfcl = p ? fat[lfcl].next : lostDir->head;
1071 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
1072 			/* Extend LOSTDIR?				XXX */
1073 			pwarn("No space in %s\n", LOSTDIR);
1074 			lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0;
1075 			return FSERROR;
1076 		}
1077 		lfoff = lfcl * boot->ClusterSize
1078 		    + boot->ClusterOffset * boot->bpbBytesPerSec;
1079 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
1080 		    || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
1081 			perr("could not read LOST.DIR");
1082 			return FSFATAL;
1083 		}
1084 		p = lfbuf;
1085 	}
1086 
1087 	boot->NumFiles++;
1088 	/* Ensure uniqueness of entry here!				XXX */
1089 	memset(&d, 0, sizeof d);
1090 	/* worst case -1 = 4294967295, 10 digits */
1091 	len = snprintf(d.name, sizeof(d.name), "%u", head);
1092 	d.flags = 0;
1093 	d.head = head;
1094 	d.size = fat[head].length * boot->ClusterSize;
1095 
1096 	memcpy(p, d.name, len);
1097 	memset(p + len, ' ', 11 - len);
1098 	memset(p + 11, 0, 32 - 11);
1099 	p[26] = (u_char)d.head;
1100 	p[27] = (u_char)(d.head >> 8);
1101 	if (boot->ClustMask == CLUST32_MASK) {
1102 		p[20] = (u_char)(d.head >> 16);
1103 		p[21] = (u_char)(d.head >> 24);
1104 	}
1105 	p[28] = (u_char)d.size;
1106 	p[29] = (u_char)(d.size >> 8);
1107 	p[30] = (u_char)(d.size >> 16);
1108 	p[31] = (u_char)(d.size >> 24);
1109 	fat[head].flags |= FAT_USED;
1110 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
1111 	    || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
1112 		perr("could not write LOST.DIR");
1113 		return FSFATAL;
1114 	}
1115 	return FSDIRMOD;
1116 }
1117 
1118 void
1119 finishlf(void)
1120 {
1121 	if (lfbuf)
1122 		free(lfbuf);
1123 	lfbuf = NULL;
1124 }
1125