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