xref: /freebsd-12.1/sbin/fsck_msdosfs/dir.c (revision 251c3371)
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  * ([email protected]), 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 <inttypes.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <ctype.h>
43 #include <unistd.h>
44 #include <time.h>
45 
46 #include <sys/param.h>
47 
48 #include "ext.h"
49 #include "fsutil.h"
50 
51 #define	SLOT_EMPTY	0x00		/* slot has never been used */
52 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
53 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
54 
55 #define	ATTR_NORMAL	0x00		/* normal file */
56 #define	ATTR_READONLY	0x01		/* file is readonly */
57 #define	ATTR_HIDDEN	0x02		/* file is hidden */
58 #define	ATTR_SYSTEM	0x04		/* file is a system file */
59 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
60 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
61 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
62 
63 #define	ATTR_WIN95	0x0f		/* long name record */
64 
65 /*
66  * This is the format of the contents of the deTime field in the direntry
67  * structure.
68  * We don't use bitfields because we don't know how compilers for
69  * arbitrary machines will lay them out.
70  */
71 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
72 #define DT_2SECONDS_SHIFT	0
73 #define DT_MINUTES_MASK		0x7E0	/* minutes */
74 #define DT_MINUTES_SHIFT	5
75 #define DT_HOURS_MASK		0xF800	/* hours */
76 #define DT_HOURS_SHIFT		11
77 
78 /*
79  * This is the format of the contents of the deDate field in the direntry
80  * structure.
81  */
82 #define DD_DAY_MASK		0x1F	/* day of month */
83 #define DD_DAY_SHIFT		0
84 #define DD_MONTH_MASK		0x1E0	/* month */
85 #define DD_MONTH_SHIFT		5
86 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
87 #define DD_YEAR_SHIFT		9
88 
89 
90 /* dir.c */
91 static struct dosDirEntry *newDosDirEntry(void);
92 static void freeDosDirEntry(struct dosDirEntry *);
93 static struct dirTodoNode *newDirTodo(void);
94 static void freeDirTodo(struct dirTodoNode *);
95 static char *fullpath(struct dosDirEntry *);
96 static u_char calcShortSum(u_char *);
97 static int delete(int, struct bootblock *, struct fatEntry *, cl_t, int,
98     cl_t, int, int);
99 static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
100     u_char *, cl_t, cl_t, cl_t, char *, int);
101 static int checksize(struct bootblock *, struct fatEntry *, u_char *,
102     struct dosDirEntry *);
103 static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
104     struct dosDirEntry *);
105 
106 /*
107  * Manage free dosDirEntry structures.
108  */
109 static struct dosDirEntry *freede;
110 
111 static struct dosDirEntry *
newDosDirEntry(void)112 newDosDirEntry(void)
113 {
114 	struct dosDirEntry *de;
115 
116 	if (!(de = freede)) {
117 		if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
118 			return 0;
119 	} else
120 		freede = de->next;
121 	return de;
122 }
123 
124 static void
freeDosDirEntry(struct dosDirEntry * de)125 freeDosDirEntry(struct dosDirEntry *de)
126 {
127 	de->next = freede;
128 	freede = de;
129 }
130 
131 /*
132  * The same for dirTodoNode structures.
133  */
134 static struct dirTodoNode *freedt;
135 
136 static struct dirTodoNode *
newDirTodo(void)137 newDirTodo(void)
138 {
139 	struct dirTodoNode *dt;
140 
141 	if (!(dt = freedt)) {
142 		if (!(dt = (struct dirTodoNode *)malloc(sizeof *dt)))
143 			return 0;
144 	} else
145 		freedt = dt->next;
146 	return dt;
147 }
148 
149 static void
freeDirTodo(struct dirTodoNode * dt)150 freeDirTodo(struct dirTodoNode *dt)
151 {
152 	dt->next = freedt;
153 	freedt = dt;
154 }
155 
156 /*
157  * The stack of unread directories
158  */
159 static struct dirTodoNode *pendingDirectories = NULL;
160 
161 /*
162  * Return the full pathname for a directory entry.
163  */
164 static char *
fullpath(struct dosDirEntry * dir)165 fullpath(struct dosDirEntry *dir)
166 {
167 	static char namebuf[MAXPATHLEN + 1];
168 	char *cp, *np;
169 	int nl;
170 
171 	cp = namebuf + sizeof namebuf;
172 	*--cp = '\0';
173 
174 	for(;;) {
175 		np = dir->lname[0] ? dir->lname : dir->name;
176 		nl = strlen(np);
177 		if (cp <= namebuf + 1 + nl) {
178 			*--cp = '?';
179 			break;
180 		}
181 		cp -= nl;
182 		memcpy(cp, np, nl);
183 		dir = dir->parent;
184 		if (!dir)
185 			break;
186 		*--cp = '/';
187 	}
188 
189 	return cp;
190 }
191 
192 /*
193  * Calculate a checksum over an 8.3 alias name
194  */
195 static u_char
calcShortSum(u_char * p)196 calcShortSum(u_char *p)
197 {
198 	u_char sum = 0;
199 	int i;
200 
201 	for (i = 0; i < 11; i++) {
202 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
203 		sum += p[i];
204 	}
205 
206 	return sum;
207 }
208 
209 /*
210  * Global variables temporarily used during a directory scan
211  */
212 static char longName[DOSLONGNAMELEN] = "";
213 static u_char *buffer = NULL;
214 static u_char *delbuf = NULL;
215 
216 static struct dosDirEntry *rootDir;
217 static struct dosDirEntry *lostDir;
218 
219 /*
220  * Init internal state for a new directory scan.
221  */
222 int
resetDosDirSection(struct bootblock * boot,struct fatEntry * fat)223 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
224 {
225 	int b1, b2;
226 	int ret = FSOK;
227 	size_t len;
228 
229 	b1 = boot->bpbRootDirEnts * 32;
230 	b2 = boot->bpbSecPerClust * boot->bpbBytesPerSec;
231 
232 	if ((buffer = malloc(len = MAX(b1, b2))) == NULL) {
233 		perr("No space for directory buffer (%zu)", len);
234 		return FSFATAL;
235 	}
236 
237 	if ((delbuf = malloc(len = b2)) == NULL) {
238 		free(buffer);
239 		perr("No space for directory delbuf (%zu)", len);
240 		return FSFATAL;
241 	}
242 
243 	if ((rootDir = newDosDirEntry()) == NULL) {
244 		free(buffer);
245 		free(delbuf);
246 		perr("No space for directory entry");
247 		return FSFATAL;
248 	}
249 
250 	memset(rootDir, 0, sizeof *rootDir);
251 	if (boot->flags & FAT32) {
252 		if (boot->bpbRootClust < CLUST_FIRST ||
253 		    boot->bpbRootClust >= boot->NumClusters) {
254 			pfatal("Root directory starts with cluster out of range(%u)",
255 			       boot->bpbRootClust);
256 			return FSFATAL;
257 		}
258 		if (fat[boot->bpbRootClust].head != boot->bpbRootClust) {
259 			pfatal("Root directory doesn't start a cluster chain");
260 			return FSFATAL;
261 		}
262 
263 		fat[boot->bpbRootClust].flags |= FAT_USED;
264 		rootDir->head = boot->bpbRootClust;
265 	}
266 
267 	return ret;
268 }
269 
270 /*
271  * Cleanup after a directory scan
272  */
273 void
finishDosDirSection(void)274 finishDosDirSection(void)
275 {
276 	struct dirTodoNode *p, *np;
277 	struct dosDirEntry *d, *nd;
278 
279 	for (p = pendingDirectories; p; p = np) {
280 		np = p->next;
281 		freeDirTodo(p);
282 	}
283 	pendingDirectories = NULL;
284 	for (d = rootDir; d; d = nd) {
285 		if ((nd = d->child) != NULL) {
286 			d->child = 0;
287 			continue;
288 		}
289 		if (!(nd = d->next))
290 			nd = d->parent;
291 		freeDosDirEntry(d);
292 	}
293 	rootDir = lostDir = NULL;
294 	free(buffer);
295 	free(delbuf);
296 	buffer = NULL;
297 	delbuf = NULL;
298 }
299 
300 /*
301  * Delete directory entries between startcl, startoff and endcl, endoff.
302  */
303 static int
delete(int f,struct bootblock * boot,struct fatEntry * fat,cl_t startcl,int startoff,cl_t endcl,int endoff,int notlast)304 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
305     int startoff, cl_t endcl, int endoff, int notlast)
306 {
307 	u_char *s, *e;
308 	off_t off;
309 	int clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
310 
311 	s = delbuf + startoff;
312 	e = delbuf + clsz;
313 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
314 		if (startcl == endcl) {
315 			if (notlast)
316 				break;
317 			e = delbuf + endoff;
318 		}
319 		off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
320 		off *= boot->bpbBytesPerSec;
321 		if (lseek(f, off, SEEK_SET) != off) {
322 			perr("Unable to lseek to %" PRId64, off);
323 			return FSFATAL;
324 		}
325 		if (read(f, delbuf, clsz) != clsz) {
326 			perr("Unable to read directory");
327 			return FSFATAL;
328 		}
329 		while (s < e) {
330 			*s = SLOT_DELETED;
331 			s += 32;
332 		}
333 		if (lseek(f, off, SEEK_SET) != off) {
334 			perr("Unable to lseek to %" PRId64, off);
335 			return FSFATAL;
336 		}
337 		if (write(f, delbuf, clsz) != clsz) {
338 			perr("Unable to write directory");
339 			return FSFATAL;
340 		}
341 		if (startcl == endcl)
342 			break;
343 		startcl = fat[startcl].next;
344 		s = delbuf;
345 	}
346 	return FSOK;
347 }
348 
349 static int
removede(int f,struct bootblock * boot,struct fatEntry * fat,u_char * start,u_char * end,cl_t startcl,cl_t endcl,cl_t curcl,char * path,int type)350 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
351     u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
352 {
353 	switch (type) {
354 	case 0:
355 		pwarn("Invalid long filename entry for %s\n", path);
356 		break;
357 	case 1:
358 		pwarn("Invalid long filename entry at end of directory %s\n",
359 		    path);
360 		break;
361 	case 2:
362 		pwarn("Invalid long filename entry for volume label\n");
363 		break;
364 	}
365 	if (ask(0, "Remove")) {
366 		if (startcl != curcl) {
367 			if (delete(f, boot, fat,
368 				   startcl, start - buffer,
369 				   endcl, end - buffer,
370 				   endcl == curcl) == FSFATAL)
371 				return FSFATAL;
372 			start = buffer;
373 		}
374 		/* startcl is < CLUST_FIRST for !fat32 root */
375 		if ((endcl == curcl) || (startcl < CLUST_FIRST))
376 			for (; start < end; start += 32)
377 				*start = SLOT_DELETED;
378 		return FSDIRMOD;
379 	}
380 	return FSERROR;
381 }
382 
383 /*
384  * Check an in-memory file entry
385  */
386 static int
checksize(struct bootblock * boot,struct fatEntry * fat,u_char * p,struct dosDirEntry * dir)387 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
388     struct dosDirEntry *dir)
389 {
390 	/*
391 	 * Check size on ordinary files
392 	 */
393 	u_int32_t physicalSize;
394 
395 	if (dir->head == CLUST_FREE)
396 		physicalSize = 0;
397 	else {
398 		if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
399 			return FSERROR;
400 		physicalSize = fat[dir->head].length * boot->ClusterSize;
401 	}
402 	if (physicalSize < dir->size) {
403 		pwarn("size of %s is %u, should at most be %u\n",
404 		      fullpath(dir), dir->size, physicalSize);
405 		if (ask(1, "Truncate")) {
406 			dir->size = physicalSize;
407 			p[28] = (u_char)physicalSize;
408 			p[29] = (u_char)(physicalSize >> 8);
409 			p[30] = (u_char)(physicalSize >> 16);
410 			p[31] = (u_char)(physicalSize >> 24);
411 			return FSDIRMOD;
412 		} else
413 			return FSERROR;
414 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
415 		pwarn("%s has too many clusters allocated\n",
416 		      fullpath(dir));
417 		if (ask(1, "Drop superfluous clusters")) {
418 			cl_t cl;
419 			u_int32_t sz, len;
420 
421 			for (cl = dir->head, len = sz = 0;
422 			    (sz += boot->ClusterSize) < dir->size; len++)
423 				cl = fat[cl].next;
424 			clearchain(boot, fat, fat[cl].next);
425 			fat[cl].next = CLUST_EOF;
426 			fat[dir->head].length = len;
427 			return FSFATMOD;
428 		} else
429 			return FSERROR;
430 	}
431 	return FSOK;
432 }
433 
434 /*
435  * Read a directory and
436  *   - resolve long name records
437  *   - enter file and directory records into the parent's list
438  *   - push directories onto the todo-stack
439  */
440 static int
readDosDirSection(int f,struct bootblock * boot,struct fatEntry * fat,struct dosDirEntry * dir)441 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
442     struct dosDirEntry *dir)
443 {
444 	struct dosDirEntry dirent, *d;
445 	u_char *p, *vallfn, *invlfn, *empty;
446 	off_t off;
447 	int i, j, k, last;
448 	cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
449 	char *t;
450 	u_int lidx = 0;
451 	int shortSum;
452 	int mod = FSOK;
453 #define	THISMOD	0x8000			/* Only used within this routine */
454 
455 	cl = dir->head;
456 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
457 		/*
458 		 * Already handled somewhere else.
459 		 */
460 		return FSOK;
461 	}
462 	shortSum = -1;
463 	vallfn = invlfn = empty = NULL;
464 	do {
465 		if (!(boot->flags & FAT32) && !dir->parent) {
466 			last = boot->bpbRootDirEnts * 32;
467 			off = boot->bpbResSectors + boot->bpbFATs *
468 			    boot->FATsecs;
469 		} else {
470 			last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
471 			off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
472 		}
473 
474 		off *= boot->bpbBytesPerSec;
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 						for (; q < p; q += 32)
513 							*q = SLOT_DELETED;
514 						mod |= THISMOD|FSDIRMOD;
515 					} else if (ask(0, "Truncate"))
516 						dir->fsckflags |= DIREMPWARN;
517 				}
518 				if (dir->fsckflags & DIREMPWARN) {
519 					*p = SLOT_DELETED;
520 					mod |= THISMOD|FSDIRMOD;
521 					continue;
522 				} else if (dir->fsckflags & DIREMPTY)
523 					mod |= FSERROR;
524 				empty = NULL;
525 			}
526 
527 			if (p[11] == ATTR_WIN95) {
528 				if (*p & LRFIRST) {
529 					if (shortSum != -1) {
530 						if (!invlfn) {
531 							invlfn = vallfn;
532 							invcl = valcl;
533 						}
534 					}
535 					memset(longName, 0, sizeof longName);
536 					shortSum = p[13];
537 					vallfn = p;
538 					valcl = cl;
539 				} else if (shortSum != p[13]
540 					   || lidx != (*p & LRNOMASK)) {
541 					if (!invlfn) {
542 						invlfn = vallfn;
543 						invcl = valcl;
544 					}
545 					if (!invlfn) {
546 						invlfn = p;
547 						invcl = cl;
548 					}
549 					vallfn = NULL;
550 				}
551 				lidx = *p & LRNOMASK;
552 				t = longName + --lidx * 13;
553 				for (k = 1; k < 11 && t < longName +
554 				    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 (k < 0 || 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
handleDirTree(int dosfs,struct bootblock * boot,struct fatEntry * fat)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
reconnect(int dosfs,struct bootblock * boot,struct fatEntry * fat,cl_t head)922 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
923 {
924 	struct dosDirEntry d;
925 	int len;
926 	u_char *p;
927 
928 	if (!ask(1, "Reconnect"))
929 		return FSERROR;
930 
931 	if (!lostDir) {
932 		for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
933 			if (!strcmp(lostDir->name, LOSTDIR))
934 				break;
935 		}
936 		if (!lostDir) {		/* Create LOSTDIR?		XXX */
937 			pwarn("No %s directory\n", LOSTDIR);
938 			return FSERROR;
939 		}
940 	}
941 	if (!lfbuf) {
942 		lfbuf = malloc(boot->ClusterSize);
943 		if (!lfbuf) {
944 			perr("No space for buffer");
945 			return FSFATAL;
946 		}
947 		p = NULL;
948 	} else
949 		p = lfbuf;
950 	while (1) {
951 		if (p)
952 			for (; p < lfbuf + boot->ClusterSize; p += 32)
953 				if (*p == SLOT_EMPTY
954 				    || *p == SLOT_DELETED)
955 					break;
956 		if (p && p < lfbuf + boot->ClusterSize)
957 			break;
958 		lfcl = p ? fat[lfcl].next : lostDir->head;
959 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
960 			/* Extend LOSTDIR?				XXX */
961 			pwarn("No space in %s\n", LOSTDIR);
962 			return FSERROR;
963 		}
964 		lfoff = lfcl * boot->ClusterSize
965 		    + boot->ClusterOffset * boot->bpbBytesPerSec;
966 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
967 		    || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
968 			perr("could not read LOST.DIR");
969 			return FSFATAL;
970 		}
971 		p = lfbuf;
972 	}
973 
974 	boot->NumFiles++;
975 	/* Ensure uniqueness of entry here!				XXX */
976 	memset(&d, 0, sizeof d);
977 	/* worst case -1 = 4294967295, 10 digits */
978 	len = snprintf(d.name, sizeof(d.name), "%u", head);
979 	d.flags = 0;
980 	d.head = head;
981 	d.size = fat[head].length * boot->ClusterSize;
982 
983 	memcpy(p, d.name, len);
984 	memset(p + len, ' ', 11 - len);
985 	memset(p + 11, 0, 32 - 11);
986 	p[26] = (u_char)d.head;
987 	p[27] = (u_char)(d.head >> 8);
988 	if (boot->ClustMask == CLUST32_MASK) {
989 		p[20] = (u_char)(d.head >> 16);
990 		p[21] = (u_char)(d.head >> 24);
991 	}
992 	p[28] = (u_char)d.size;
993 	p[29] = (u_char)(d.size >> 8);
994 	p[30] = (u_char)(d.size >> 16);
995 	p[31] = (u_char)(d.size >> 24);
996 	fat[head].flags |= FAT_USED;
997 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
998 	    || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
999 		perr("could not write LOST.DIR");
1000 		return FSFATAL;
1001 	}
1002 	return FSDIRMOD;
1003 }
1004 
1005 void
finishlf(void)1006 finishlf(void)
1007 {
1008 	if (lfbuf)
1009 		free(lfbuf);
1010 	lfbuf = NULL;
1011 }
1012