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dir.c revision 1.2
      1 /*	$NetBSD: dir.c,v 1.2 1996/05/25 17:09:44 ws Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1995, 1996 Wolfgang Solfrank
      5  * Copyright (c) 1995 Martin Husemann
      6  * Some structure declaration borrowed from Paul Popelka
      7  * (paulp (at) 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  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed by Martin Husemann
     20  *	and Wolfgang Solfrank.
     21  * 4. Neither the name of the University nor the names of its contributors
     22  *    may be used to endorse or promote products derived from this software
     23  *    without specific prior written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
     26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     28  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     35  */
     36 
     37 
     38 #ifndef lint
     39 static char rcsid[] = "$NetBSD: dir.c,v 1.2 1996/05/25 17:09:44 ws Exp $";
     40 #endif /* not lint */
     41 
     42 #include <stdio.h>
     43 #include <stdlib.h>
     44 #include <string.h>
     45 #include <ctype.h>
     46 #include <stdio.h>
     47 #include <unistd.h>
     48 #include <time.h>
     49 
     50 #include <sys/param.h>
     51 
     52 #include "ext.h"
     53 
     54 #define	SLOT_EMPTY	0x00		/* slot has never been used */
     55 #define	SLOT_E5		0x05		/* the real value is 0xe5 */
     56 #define	SLOT_DELETED	0xe5		/* file in this slot deleted */
     57 
     58 #define	ATTR_NORMAL	0x00		/* normal file */
     59 #define	ATTR_READONLY	0x01		/* file is readonly */
     60 #define	ATTR_HIDDEN	0x02		/* file is hidden */
     61 #define	ATTR_SYSTEM	0x04		/* file is a system file */
     62 #define	ATTR_VOLUME	0x08		/* entry is a volume label */
     63 #define	ATTR_DIRECTORY	0x10		/* entry is a directory name */
     64 #define	ATTR_ARCHIVE	0x20		/* file is new or modified */
     65 
     66 #define	ATTR_WIN95	0x0f		/* long name record */
     67 
     68 /*
     69  * This is the format of the contents of the deTime field in the direntry
     70  * structure.
     71  * We don't use bitfields because we don't know how compilers for
     72  * arbitrary machines will lay them out.
     73  */
     74 #define DT_2SECONDS_MASK	0x1F	/* seconds divided by 2 */
     75 #define DT_2SECONDS_SHIFT	0
     76 #define DT_MINUTES_MASK		0x7E0	/* minutes */
     77 #define DT_MINUTES_SHIFT	5
     78 #define DT_HOURS_MASK		0xF800	/* hours */
     79 #define DT_HOURS_SHIFT		11
     80 
     81 /*
     82  * This is the format of the contents of the deDate field in the direntry
     83  * structure.
     84  */
     85 #define DD_DAY_MASK		0x1F	/* day of month */
     86 #define DD_DAY_SHIFT		0
     87 #define DD_MONTH_MASK		0x1E0	/* month */
     88 #define DD_MONTH_SHIFT		5
     89 #define DD_YEAR_MASK		0xFE00	/* year - 1980 */
     90 #define DD_YEAR_SHIFT		9
     91 
     92 /*
     93  * Return the full pathname for a directory entry.
     94  */
     95 static char *
     96 fullpath(dir)
     97 	struct dosDirEntry *dir;
     98 {
     99 	static char namebuf[MAXPATHLEN + 1];
    100 	char *cp, *np;
    101 	int nl;
    102 
    103 	cp = namebuf + sizeof namebuf - 1;
    104 	*cp = '\0';
    105 	do {
    106 		np = dir->lname[0] ? dir->lname : dir->name;
    107 		nl = strlen(np);
    108 		if ((cp -= nl) <= namebuf + 1)
    109 			break;
    110 		memcpy(cp, np, nl);
    111 		*--cp = '/';
    112        } while (dir = dir->parent);
    113 	if (dir->parent)
    114 		*--cp = '?';
    115 	return cp;
    116 }
    117 
    118 /*
    119  * Calculate a checksum over an 8.3 alias name
    120  */
    121 static u_char
    122 calcShortSum(p)
    123 	u_char *p;
    124 {
    125 	u_char sum = 0;
    126 	int i;
    127 
    128 	for (i = 0; i < 11; i++) {
    129 		sum = (sum << 7)|(sum >> 1);	/* rotate right */
    130 		sum += p[i];
    131 	}
    132 
    133 	return sum;
    134 }
    135 
    136 /*
    137  * Global variables temporarily used during a directory scan
    138  */
    139 static char longName[DOSLONGNAMELEN] = "";
    140 static u_char *buffer = NULL;
    141 static u_char *delbuf = NULL;
    142 
    143 /*
    144  * Init internal state for a new directory scan.
    145  */
    146 int
    147 resetDosDirSection(boot)
    148 	struct bootblock *boot;
    149 {
    150 	int b1, b2;
    151 
    152 	b1 = boot->RootDirEnts * 32;
    153 	b2 = boot->SecPerClust * boot->BytesPerSec;
    154 
    155 	if (!(buffer = malloc(b1 > b2 ? b1 : b2))
    156 	    || !(delbuf = malloc(b2))) {
    157 		perror("No space for directory");
    158 		return FSFATAL;
    159 	}
    160 	return FSOK;
    161 }
    162 
    163 /*
    164  * Cleanup after a directory scan
    165  */
    166 void
    167 finishDosDirSection()
    168 {
    169 	free(buffer);
    170 	free(delbuf);
    171 	buffer = NULL;
    172 	delbuf = NULL;
    173 }
    174 
    175 /*
    176  * Delete directory entries between startcl, startoff and endcl, endoff.
    177  */
    178 static int
    179 delete(f, boot, fat, startcl, startoff, endcl, endoff, notlast)
    180 	int f;
    181 	struct bootblock *boot;
    182 	struct fatEntry *fat;
    183 	cl_t startcl;
    184 	int startoff;
    185 	cl_t endcl;
    186 	int endoff;
    187 	int notlast;
    188 {
    189 	u_char *s, *e;
    190 	off_t off;
    191 	int clsz = boot->SecPerClust * boot->BytesPerSec;
    192 
    193 	s = delbuf + startoff;
    194 	e = delbuf + clsz;
    195 	while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
    196 		if (startcl == endcl) {
    197 			if (notlast)
    198 				break;
    199 			e = delbuf + endoff;
    200 		}
    201 		off = startcl * boot->SecPerClust + boot->ClusterOffset;
    202 		off *= boot->BytesPerSec;
    203 		if (lseek(f, off, SEEK_SET) != off
    204 		    || read(f, delbuf, clsz) != clsz) {
    205 			perror("Unable to read directory");
    206 			return FSFATAL;
    207 		}
    208 		while (s < e) {
    209 			*s = SLOT_DELETED;
    210 			s += 32;
    211 		}
    212 		if (lseek(f, off, SEEK_SET) != off
    213 		    || write(f, delbuf, clsz) != clsz) {
    214 			perror("Unable to write directory");
    215 			return FSFATAL;
    216 		}
    217 		if (startcl == endcl)
    218 			break;
    219 		startcl = fat[startcl].next;
    220 		s = delbuf;
    221 	}
    222 	return FSOK;
    223 }
    224 
    225 static int
    226 removede(f, boot, fat, start, end, startcl, endcl, curcl, path, eof)
    227 	int f;
    228 	struct bootblock *boot;
    229 	struct fatEntry *fat;
    230 	u_char *start;
    231 	u_char *end;
    232 	cl_t startcl;
    233 	cl_t endcl;
    234 	cl_t curcl;
    235 	char *path;
    236 	int eof;
    237 {
    238 	if (!eof)
    239 		pwarn("Invalid long filename entry for %s\n", path);
    240 	else
    241 		pwarn("Invalid long filename entry at end of directory %s\n", path);
    242 	if (ask(0, "Remove")) {
    243 		if (startcl != curcl) {
    244 			if (delete(f, boot, fat,
    245 				   startcl, start - buffer,
    246 				   endcl, end - buffer,
    247 				   endcl == curcl) == FSFATAL)
    248 				return FSFATAL;
    249 			start = buffer;
    250 		}
    251 		if (endcl == curcl)
    252 			for (; start < end; start += 32)
    253 				*start = SLOT_DELETED;
    254 		return FSDIRMOD;
    255 	}
    256 	return FSERROR;
    257 }
    258 
    259 /*
    260  * Check an in-memory file entry
    261  */
    262 static int
    263 checksize(boot, fat, p, dir)
    264 	struct bootblock *boot;
    265 	struct fatEntry *fat;
    266 	u_char *p;
    267 	struct dosDirEntry *dir;
    268 {
    269 	/*
    270 	 * Check size on ordinary files
    271 	 */
    272 	u_int32_t physicalSize;
    273 
    274 	if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
    275 		return FSERROR;
    276 	physicalSize = fat[dir->head].length * boot->ClusterSize;
    277 	if (physicalSize < dir->size) {
    278 		pwarn("size of %s is %lu, should at most be %lu\n",
    279 		      fullpath(dir), dir->size, physicalSize);
    280 		if (ask(1, "Truncate")) {
    281 			dir->size = physicalSize;
    282 			p[28] = (u_char)physicalSize;
    283 			p[29] = (u_char)(physicalSize >> 8);
    284 			p[30] = (u_char)(physicalSize >> 16);
    285 			p[31] = (u_char)(physicalSize >> 24);
    286 			return FSDIRMOD;
    287 		} else
    288 			return FSERROR;
    289 	} else if (physicalSize - dir->size >= boot->ClusterSize) {
    290 		pwarn("%s has too many clusters allocated\n",
    291 		      fullpath(dir));
    292 		if (ask(1, "Drop superfluous clusters")) {
    293 			cl_t cl;
    294 			u_int32_t sz = 0;
    295 
    296 			for (cl = dir->head; (sz += boot->ClusterSize) < dir->size;)
    297 				cl = fat[cl].next;
    298 			clearchain(boot, fat, fat[cl].next);
    299 			fat[cl].next = CLUST_EOF;
    300 			return FSFATMOD;
    301 		} else
    302 			return FSERROR;
    303 	}
    304 	return FSOK;
    305 }
    306 
    307 /*
    308  * The stack of unread directories
    309  */
    310 struct dirTodoNode *pendingDirectories = NULL;
    311 
    312 /*
    313  * Read a directory and
    314  *   - resolve long name records
    315  *   - enter file and directory records into the parent's list
    316  *   - push directories onto the todo-stack
    317  */
    318 int
    319 readDosDirSection(f, boot, fat, dir)
    320 	int f;
    321 	struct bootblock *boot;
    322 	struct fatEntry *fat;
    323 	struct dosDirEntry *dir;
    324 {
    325 	struct dosDirEntry dirent, *d;
    326 	u_char *p, *vallfn, *invlfn, *empty;
    327 	off_t off;
    328 	int i, j, k, last;
    329 	cl_t cl, valcl, invcl, empcl;
    330 	char *t;
    331 	u_int lidx = 0;
    332 	int shortSum;
    333 	int mod = FSOK;
    334 #define	THISMOD	0x8000			/* Only used within this routine */
    335 
    336 	cl = dir->head;
    337 	if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
    338 		/*
    339 		 * Already handled somewhere else.
    340 		 */
    341 		return FSOK;
    342 	}
    343 	shortSum = -1;
    344 	vallfn = invlfn = empty = NULL;
    345 	do {
    346 		if (!dir->parent) {
    347 			last = boot->RootDirEnts * 32;
    348 			off = boot->ResSectors + boot->FATs * boot->FATsecs;
    349 		} else {
    350 			last = boot->SecPerClust * boot->BytesPerSec;
    351 			off = cl * boot->SecPerClust + boot->ClusterOffset;
    352 		}
    353 
    354 		off *= boot->BytesPerSec;
    355 		if (lseek(f, off, SEEK_SET) != off
    356 		    || read(f, buffer, last) != last) {
    357 			perror("Unable to read directory");
    358 			return FSFATAL;
    359 		}
    360 		last /= 32;
    361 		/*
    362 		 * Check `.' and `..' entries here?			XXX
    363 		 */
    364 		for (p = buffer, i = 0; i < last; i++, p += 32) {
    365 			if (dir->fsckflags & DIREMPWARN) {
    366 				*p = SLOT_EMPTY;
    367 				continue;
    368 			}
    369 
    370 			if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
    371 				if (*p == SLOT_EMPTY) {
    372 					dir->fsckflags |= DIREMPTY;
    373 					empty = p;
    374 					empcl = cl;
    375 				}
    376 				continue;
    377 			}
    378 
    379 			if (dir->fsckflags & DIREMPTY) {
    380 				if (!(dir->fsckflags & DIREMPWARN)) {
    381 					pwarn("%s has entries after end of directory\n",
    382 					      fullpath(dir));
    383 					if (ask(1, "Extend")) {
    384 						dir->fsckflags &= ~DIREMPTY;
    385 						if (delete(f, boot, fat,
    386 							   empcl, empty - buffer,
    387 							   cl, p - buffer) == FSFATAL)
    388 							return FSFATAL;
    389 					} else if (ask(0, "Truncate"))
    390 						dir->fsckflags |= DIREMPWARN;
    391 				}
    392 				if (dir->fsckflags & DIREMPWARN) {
    393 					*p = SLOT_DELETED;
    394 					mod |= THISMOD|FSDIRMOD;
    395 					continue;
    396 				} else if (dir->fsckflags & DIREMPTY)
    397 					mod |= FSERROR;
    398 				empty = NULL;
    399 			}
    400 
    401 			if (p[11] == ATTR_WIN95) {
    402 				if (*p & LRFIRST) {
    403 					if (shortSum != -1) {
    404 						if (!invlfn) {
    405 							invlfn = vallfn;
    406 							invcl = valcl;
    407 						}
    408 					}
    409 					memset(longName, 0, sizeof longName);
    410 					shortSum = p[13];
    411 					vallfn = p;
    412 					valcl = cl;
    413 				} else if (shortSum != p[13]
    414 					   || lidx != *p & LRNOMASK) {
    415 					if (!invlfn) {
    416 						invlfn = vallfn;
    417 						invcl = valcl;
    418 					}
    419 					if (!invlfn) {
    420 						invlfn = p;
    421 						invcl = cl;
    422 					}
    423 					vallfn = NULL;
    424 				}
    425 				lidx = *p & LRNOMASK;
    426 				t = longName + --lidx * 13;
    427 				for (k = 1; k < 11 && t < longName + sizeof(longName); k += 2) {
    428 					if (!p[k] && !p[k + 1])
    429 						break;
    430 					*t++ = p[k];
    431 					/*
    432 					 * Warn about those unusable chars in msdosfs here?	XXX
    433 					 */
    434 					if (p[k + 1])
    435 						t[-1] = '?';
    436 				}
    437 				if (k >= 11)
    438 					for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
    439 						if (!p[k] && !p[k + 1])
    440 							break;
    441 						*t++ = p[k];
    442 						if (p[k + 1])
    443 							t[-1] = '?';
    444 					}
    445 				if (k >= 26)
    446 					for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
    447 						if (!p[k] && !p[k + 1])
    448 							break;
    449 						*t++ = p[k];
    450 						if (p[k + 1])
    451 							t[-1] = '?';
    452 					}
    453 				if (t >= longName + sizeof(longName)) {
    454 					pwarn("long filename too long\n");
    455 					if (!invlfn) {
    456 						invlfn = vallfn;
    457 						invcl = valcl;
    458 					}
    459 					vallfn = NULL;
    460 				}
    461 				if (p[26] | (p[27] << 8)) {
    462 					pwarn("long filename record cluster start != 0\n");
    463 					if (!invlfn) {
    464 						invlfn = vallfn;
    465 						invcl = cl;
    466 					}
    467 					vallfn = NULL;
    468 				}
    469 				continue;	/* long records don't carry further
    470 						 * information */
    471 			}
    472 
    473 			/*
    474 			 * This is a standard msdosfs directory entry.
    475 			 */
    476 			memset(&dirent, 0, sizeof dirent);
    477 
    478 			/*
    479 			 * it's a short name record, but we need to know
    480 			 * more, so get the flags first.
    481 			 */
    482 			dirent.flags = p[11];
    483 
    484 			/*
    485 			 * Translate from 850 to ISO here		XXX
    486 			 */
    487 			for (j = 0; j < 8; j++)
    488 				dirent.name[j] = p[j];
    489 			dirent.name[8] = '\0';
    490 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
    491 				dirent.name[k] = '\0';
    492 			if (dirent.name[k] != '\0')
    493 				k++;
    494 			if (dirent.name[0] == SLOT_E5)
    495 				dirent.name[0] = 0xe5;
    496 			/*
    497 			 * What about volume names with extensions?	XXX
    498 			 */
    499 			if ((dirent.flags & ATTR_VOLUME) == 0 && p[8] != ' ')
    500 				dirent.name[k++] = '.';
    501 			for (j = 0; j < 3; j++)
    502 				dirent.name[k++] = p[j+8];
    503 			dirent.name[k] = '\0';
    504 			for (k--; k >= 0 && dirent.name[k] == ' '; k--)
    505 				dirent.name[k] = '\0';
    506 
    507 			if (vallfn && shortSum != calcShortSum(p)) {
    508 				if (!invlfn) {
    509 					invlfn = vallfn;
    510 					invcl = valcl;
    511 				}
    512 				vallfn = NULL;
    513 			}
    514 			dirent.head = p[26] | (p[27] << 8);
    515 			dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
    516 			if (vallfn) {
    517 				strcpy(dirent.lname, longName);
    518 				longName[0] = '\0';
    519 				shortSum = -1;
    520 			}
    521 
    522 			if (invlfn) {
    523 				mod |= k = removede(f, boot, fat,
    524 						    invlfn, vallfn ? vallfn : p,
    525 						    invcl, vallfn ? valcl : cl, cl,
    526 						    fullpath(&dirent), 0);
    527 				if (mod & FSFATAL)
    528 					return FSFATAL;
    529 				if (vallfn
    530 				    ? (valcl == cl && vallfn != buffer)
    531 				    : p != buffer)
    532 					if (k & FSDIRMOD)
    533 						mod |= THISMOD;
    534 			}
    535 			vallfn = NULL; /* not used any longer */
    536 			invlfn = NULL;
    537 
    538 			if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
    539 				if (dirent.head != 0) {
    540 					pwarn("%s has clusters, but size 0\n",
    541 					      fullpath(&dirent));
    542 					if (ask(1, "Drop allocated clusters")) {
    543 						p[26] = p[27] = 0;
    544 						clearchain(boot, fat, dirent.head);
    545 						dirent.head = 0;
    546 						mod |= THISMOD|FSDIRMOD|FSFATMOD;
    547 					} else
    548 						mod |= FSERROR;
    549 				}
    550 			} else if (dirent.head == 0
    551 				   && !strcmp(dirent.name, "..")
    552 				   && !dir->parent->parent) {
    553 				/*
    554 				 *  Do nothing, the parent is the root
    555 				 */
    556 			} else if (dirent.head < CLUST_FIRST
    557 				   || dirent.head >= boot->NumClusters
    558 				   || fat[dirent.head].next == CLUST_FREE
    559 				   || (fat[dirent.head].next >= CLUST_RSRVD
    560 				       && fat[dirent.head].next < CLUST_EOFS)
    561 				   || fat[dirent.head].head != dirent.head) {
    562 				if (dirent.head == 0)
    563 					pwarn("%s has no clusters\n",
    564 					      fullpath(&dirent));
    565 				else if (dirent.head < CLUST_FIRST
    566 					 || dirent.head >= boot->NumClusters)
    567 					pwarn("%s starts with cluster out of range(%d)\n",
    568 					      fullpath(&dirent),
    569 					      dirent.head);
    570 				else if (fat[dirent.head].next == CLUST_FREE)
    571 					pwarn("%s starts with free cluster\n",
    572 					      fullpath(&dirent));
    573 				else if (fat[dirent.head].next >= CLUST_RSRVD)
    574 					pwarn("%s starts with %s cluster\n",
    575 					      fullpath(&dirent),
    576 					      rsrvdcltype(fat[dirent.head].next));
    577 				else
    578 					pwarn("%s doesn't start a cluster chain\n",
    579 					      fullpath(&dirent));
    580 				if (dirent.flags & ATTR_DIRECTORY) {
    581 					if (ask(0, "Remove")) {
    582 						*p = SLOT_DELETED;
    583 						mod |= THISMOD|FSDIRMOD;
    584 					} else
    585 						mod |= FSERROR;
    586 					continue;
    587 				} else {
    588 					if (ask(1, "Truncate")) {
    589 						p[28] = p[29] = p[30] = p[31] = 0;
    590 						dirent.size = 0;
    591 						mod |= THISMOD|FSDIRMOD;
    592 					} else
    593 						mod |= FSERROR;
    594 				}
    595 			}
    596 
    597 			/* create directory tree node */
    598 			if (!(d = malloc(sizeof(struct dosDirEntry)))) {
    599 				perror("No space for directory");
    600 				return FSFATAL;
    601 			}
    602 
    603 			memcpy(d, &dirent, sizeof(struct dosDirEntry));
    604 			/* link it into the directory tree */
    605 			d->parent = dir;
    606 			d->next = dir->child;
    607 			dir->child = d;
    608 			if (d->head >= CLUST_FIRST && d->head < boot->NumClusters)
    609 				fat[d->head].dirp = d;
    610 
    611 			if (d->flags & ATTR_DIRECTORY) {
    612 				/*
    613 				 * gather more info for directories
    614 				 */
    615 				struct dirTodoNode * n;
    616 
    617 				if (d->size) {
    618 					pwarn("Directory %s has size != 0\n",
    619 					      fullpath(d));
    620 					if (ask(1, "Correct")) {
    621 						p[28] = p[29] = p[30] = p[31] = 0;
    622 						d->size = 0;
    623 						mod |= THISMOD|FSDIRMOD;
    624 					} else
    625 						mod |= FSERROR;
    626 				}
    627 				/*
    628 				 * handle `.' and `..' specially
    629 				 */
    630 				if (strcmp(d->name, ".") == 0) {
    631 					if (d->head != dir->head) {
    632 						pwarn("`.' entry in %s has incorrect start cluster\n",
    633 						      fullpath(dir));
    634 						if (ask(1, "Correct")) {
    635 							d->head = dir->head;
    636 							p[26] = (u_char)d->head;
    637 							p[27] = (u_char)(d->head >> 8);
    638 							mod |= THISMOD|FSDIRMOD;
    639 						} else
    640 							mod |= FSERROR;
    641 					}
    642 					continue;
    643 				}
    644 				if (strcmp(d->name, "..") == 0) {
    645 					if (d->head != dir->parent->head) {
    646 						pwarn("`..' entry in %s has incorrect start cluster\n",
    647 						      fullpath(dir));
    648 						if (ask(1, "Correct")) {
    649 							d->head = dir->parent->head;
    650 							p[26] = (u_char)d->head;
    651 							p[27] = (u_char)(d->head >> 8);
    652 							mod |= THISMOD|FSDIRMOD;
    653 						} else
    654 							mod |= FSERROR;
    655 					}
    656 					continue;
    657 				}
    658 
    659 				boot->NumFiles++;
    660 				/* Enter this directory into the todo list */
    661 				if (!(n = malloc(sizeof(struct dirTodoNode)))) {
    662 					perror("No space for todo list");
    663 					return FSFATAL;
    664 				}
    665 				n->next = pendingDirectories;
    666 				n->dir = d;
    667 				pendingDirectories = n;
    668 			} else {
    669 				mod |= k = checksize(boot, fat, p, d);
    670 				if (k & FSDIRMOD)
    671 					mod |= THISMOD;
    672 				boot->NumFiles++;
    673 			}
    674 		}
    675 		if (mod & THISMOD) {
    676 			last *= 32;
    677 			if (lseek(f, off, SEEK_SET) != off
    678 			    || write(f, buffer, last) != last) {
    679 				perror("Unable to write directory");
    680 				return FSFATAL;
    681 			}
    682 			mod &= ~THISMOD;
    683 		}
    684 	} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
    685 	if (invlfn || vallfn)
    686 		mod |= removede(f, boot, fat,
    687 				invlfn ? invlfn : vallfn, p,
    688 				invlfn ? invcl : valcl, -1, 0,
    689 				fullpath(dir), 1);
    690 	return mod & ~THISMOD;
    691 }
    692 
    693 /*
    694  * Try to reconnect a FAT chain into dir
    695  */
    696 static u_char *lfbuf;
    697 static cl_t lfcl;
    698 static off_t lfoff;
    699 
    700 int
    701 reconnect(dosfs, boot, fat, head, dir)
    702 	int dosfs;
    703 	struct bootblock *boot;
    704 	struct fatEntry *fat;
    705 	cl_t head;
    706 	struct dosDirEntry *dir;
    707 {
    708 	struct dosDirEntry d;
    709 	u_char *p;
    710 
    711 	if (!dir)		/* Create lfdir?			XXX */
    712 		return FSERROR;
    713 	if (!lfbuf) {
    714 		lfbuf = malloc(boot->ClusterSize);
    715 		if (!lfbuf) {
    716 			perror("No space for buffer");
    717 			return FSFATAL;
    718 		}
    719 		p = NULL;
    720 	} else
    721 		p = lfbuf;
    722 	while (1) {
    723 		if (p)
    724 			while (p < lfbuf + boot->ClusterSize)
    725 				if (*p == SLOT_EMPTY
    726 				    || *p == SLOT_DELETED)
    727 					break;
    728 		if (p && p < lfbuf + boot->ClusterSize)
    729 			break;
    730 		lfcl = p ? fat[lfcl].next : dir->head;
    731 		if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
    732 			/* Extend lfdir?				XXX */
    733 			pwarn("No space in %s\n", LOSTDIR);
    734 			return FSERROR;
    735 		}
    736 		lfoff = lfcl * boot->ClusterSize
    737 		    + boot->ClusterOffset * boot->BytesPerSec;
    738 		if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
    739 		    || read(dosfs, buffer, boot->ClusterSize) != boot->ClusterSize) {
    740 			perror("could not read LOST.DIR");
    741 			return FSFATAL;
    742 		}
    743 		p = lfbuf;
    744 	}
    745 
    746 	if (!ask(0, "Reconnect"))
    747 		return FSERROR;
    748 
    749 	boot->NumFiles++;
    750 	/* Ensure uniqueness of entry here!				XXX */
    751 	memset(&d, 0, sizeof d);
    752 	sprintf(d.name, "%d", head);
    753 	d.flags = 0;
    754 	d.head = head;
    755 	d.size = fat[head].length * boot->ClusterSize;
    756 	d.parent = dir;
    757 	d.next = dir->child;
    758 	if (!(dir->child = malloc(sizeof(struct dosDirEntry)))) {
    759 		perror("No space for directory");
    760 		return FSFATAL;
    761 	}
    762 	memcpy(dir->child, &d, sizeof(struct dosDirEntry));
    763 
    764 	memset(p, 0, 32);
    765 	memset(p, ' ', 11);
    766 	memcpy(p, dir->name, strlen(dir->name));
    767 	p[26] = (u_char)dir->head;
    768 	p[27] = (u_char)(dir->head >> 8);
    769 	p[28] = (u_char)dir->size;
    770 	p[29] = (u_char)(dir->size >> 8);
    771 	p[30] = (u_char)(dir->size >> 16);
    772 	p[31] = (u_char)(dir->size >> 24);
    773 	fat[head].dirp = dir;
    774 	if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
    775 	    || write(dosfs, buffer, boot->ClusterSize) != boot->ClusterSize) {
    776 		perror("could not write LOST.DIR");
    777 		return FSFATAL;
    778 	}
    779 	return FSDIRMOD;
    780 }
    781 
    782 void
    783 finishlf()
    784 {
    785 	if (lfbuf)
    786 		free(lfbuf);
    787 	lfbuf = NULL;
    788 }
    789