sbin/fsck_msdosfs/dir.c

   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 <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 *
 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
 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 *
 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
 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 *
 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 - 1;
 172         *cp = '\0';
 173         do {
 174                 np = dir->lname[0] ? dir->lname : dir->name;
 175                 nl = strlen(np);
 176                 if ((cp -= nl) <= namebuf + 1)
 177                         break;
 178                 memcpy(cp, np, nl);
 179                 *--cp = '/';
 180         } while ((dir = dir->parent) != NULL);
 181         if (dir)
 182                 *--cp = '?';
 183         else
 184                 cp++;
 185         return cp;
 186 }
 187
 188 /*
 189  * Calculate a checksum over an 8.3 alias name
 190  */
 191 static u_char
 192 calcShortSum(u_char *p)
 193 {
 194         u_char sum = 0;
 195         int i;
 196
 197         for (i = 0; i < 11; i++) {
 198                 sum = (sum << 7)|(sum >> 1);    /* rotate right */
 199                 sum += p[i];
 200         }
 201
 202         return sum;
 203 }
 204
 205 /*
 206  * Global variables temporarily used during a directory scan
 207  */
 208 static char longName[DOSLONGNAMELEN] = "";
 209 static u_char *buffer = NULL;
 210 static u_char *delbuf = NULL;
 211
 212 static struct dosDirEntry *rootDir;
 213 static struct dosDirEntry *lostDir;
 214
 215 /*
 216  * Init internal state for a new directory scan.
 217  */
 218 int
 219 resetDosDirSection(struct bootblock *boot, struct fatEntry *fat)
 220 {
 221         int b1, b2;
 222         cl_t cl;
 223         int ret = FSOK;
 224         size_t len;
 225
 226         b1 = boot->bpbRootDirEnts * 32;
 227         b2 = boot->bpbSecPerClust * boot->bpbBytesPerSec;
 228
 229         if ((buffer = malloc(len = MAX(b1, b2))) == NULL) {
 230                 perr("No space for directory buffer (%zu)", len);
 231                 return FSFATAL;
 232         }
 233
 234         if ((delbuf = malloc(len = b2)) == NULL) {
 235                 free(buffer);
 236                 perr("No space for directory delbuf (%zu)", len);
 237                 return FSFATAL;
 238         }
 239
 240         if ((rootDir = newDosDirEntry()) == NULL) {
 241                 free(buffer);
 242                 free(delbuf);
 243                 perr("No space for directory entry");
 244                 return FSFATAL;
 245         }
 246
 247         memset(rootDir, 0, sizeof *rootDir);
 248         if (boot->flags & FAT32) {
 249                 if (boot->bpbRootClust < CLUST_FIRST ||
 250                     boot->bpbRootClust >= boot->NumClusters) {
 251                         pfatal("Root directory starts with cluster out of range(%u)",
 252                                boot->bpbRootClust);
 253                         return FSFATAL;
 254                 }
 255                 cl = fat[boot->bpbRootClust].next;
 256                 if (cl < CLUST_FIRST
 257                     || (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
 258                     || fat[boot->bpbRootClust].head != boot->bpbRootClust) {
 259                         if (cl == CLUST_FREE)
 260                                 pwarn("Root directory starts with free cluster\n");
 261                         else if (cl >= CLUST_RSRVD)
 262                                 pwarn("Root directory starts with cluster marked %s\n",
 263                                       rsrvdcltype(cl));
 264                         else {
 265                                 pfatal("Root directory doesn't start a cluster chain");
 266                                 return FSFATAL;
 267                         }
 268                         if (ask(1, "Fix")) {
 269                                 fat[boot->bpbRootClust].next = CLUST_FREE;
 270                                 ret = FSFATMOD;
 271                         } else
 272                                 ret = FSFATAL;
 273                 }
 274
 275                 fat[boot->bpbRootClust].flags |= FAT_USED;
 276                 rootDir->head = boot->bpbRootClust;
 277         }
 278
 279         return ret;
 280 }
 281
 282 /*
 283  * Cleanup after a directory scan
 284  */
 285 void
 286 finishDosDirSection(void)
 287 {
 288         struct dirTodoNode *p, *np;
 289         struct dosDirEntry *d, *nd;
 290
 291         for (p = pendingDirectories; p; p = np) {
 292                 np = p->next;
 293                 freeDirTodo(p);
 294         }
 295         pendingDirectories = NULL;
 296         for (d = rootDir; d; d = nd) {
 297                 if ((nd = d->child) != NULL) {
 298                         d->child = 0;
 299                         continue;
 300                 }
 301                 if (!(nd = d->next))
 302                         nd = d->parent;
 303                 freeDosDirEntry(d);
 304         }
 305         rootDir = lostDir = NULL;
 306         free(buffer);
 307         free(delbuf);
 308         buffer = NULL;
 309         delbuf = NULL;
 310 }
 311
 312 /*
 313  * Delete directory entries between startcl, startoff and endcl, endoff.
 314  */
 315 static int
 316 delete(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
 317     int startoff, cl_t endcl, int endoff, int notlast)
 318 {
 319         u_char *s, *e;
 320         off_t off;
 321         int clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
 322
 323         s = delbuf + startoff;
 324         e = delbuf + clsz;
 325         while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
 326                 if (startcl == endcl) {
 327                         if (notlast)
 328                                 break;
 329                         e = delbuf + endoff;
 330                 }
 331                 off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
 332                 off *= boot->bpbBytesPerSec;
 333                 if (lseek(f, off, SEEK_SET) != off) {
 334                         perr("Unable to lseek to %" PRId64, off);
 335                         return FSFATAL;
 336                 }
 337                 if (read(f, delbuf, clsz) != clsz) {
 338                         perr("Unable to read directory");
 339                         return FSFATAL;
 340                 }
 341                 while (s < e) {
 342                         *s = SLOT_DELETED;
 343                         s += 32;
 344                 }
 345                 if (lseek(f, off, SEEK_SET) != off) {
 346                         perr("Unable to lseek to %" PRId64, off);
 347                         return FSFATAL;
 348                 }
 349                 if (write(f, delbuf, clsz) != clsz) {
 350                         perr("Unable to write directory");
 351                         return FSFATAL;
 352                 }
 353                 if (startcl == endcl)
 354                         break;
 355                 startcl = fat[startcl].next;
 356                 s = delbuf;
 357         }
 358         return FSOK;
 359 }
 360
 361 static int
 362 removede(int f, struct bootblock *boot, struct fatEntry *fat, u_char *start,
 363     u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, char *path, int type)
 364 {
 365         switch (type) {
 366         case 0:
 367                 pwarn("Invalid long filename entry for %s\n", path);
 368                 break;
 369         case 1:
 370                 pwarn("Invalid long filename entry at end of directory %s\n",
 371                     path);
 372                 break;
 373         case 2:
 374                 pwarn("Invalid long filename entry for volume label\n");
 375                 break;
 376         }
 377         if (ask(0, "Remove")) {
 378                 if (startcl != curcl) {
 379                         if (delete(f, boot, fat,
 380                                    startcl, start - buffer,
 381                                    endcl, end - buffer,
 382                                    endcl == curcl) == FSFATAL)
 383                                 return FSFATAL;
 384                         start = buffer;
 385                 }
 386                 /* startcl is < CLUST_FIRST for !fat32 root */
 387                 if ((endcl == curcl) || (startcl < CLUST_FIRST))
 388                         for (; start < end; start += 32)
 389                                 *start = SLOT_DELETED;
 390                 return FSDIRMOD;
 391         }
 392         return FSERROR;
 393 }
 394
 395 /*
 396  * Check an in-memory file entry
 397  */
 398 static int
 399 checksize(struct bootblock *boot, struct fatEntry *fat, u_char *p,
 400     struct dosDirEntry *dir)
 401 {
 402         /*
 403          * Check size on ordinary files
 404          */
 405         u_int32_t physicalSize;
 406
 407         if (dir->head == CLUST_FREE)
 408                 physicalSize = 0;
 409         else {
 410                 if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
 411                         return FSERROR;
 412                 physicalSize = fat[dir->head].length * boot->ClusterSize;
 413         }
 414         if (physicalSize < dir->size) {
 415                 pwarn("size of %s is %u, should at most be %u\n",
 416                       fullpath(dir), dir->size, physicalSize);
 417                 if (ask(1, "Truncate")) {
 418                         dir->size = physicalSize;
 419                         p[28] = (u_char)physicalSize;
 420                         p[29] = (u_char)(physicalSize >> 8);
 421                         p[30] = (u_char)(physicalSize >> 16);
 422                         p[31] = (u_char)(physicalSize >> 24);
 423                         return FSDIRMOD;
 424                 } else
 425                         return FSERROR;
 426         } else if (physicalSize - dir->size >= boot->ClusterSize) {
 427                 pwarn("%s has too many clusters allocated\n",
 428                       fullpath(dir));
 429                 if (ask(1, "Drop superfluous clusters")) {
 430                         cl_t cl;
 431                         u_int32_t sz, len;
 432
 433                         for (cl = dir->head, len = sz = 0;
 434                             (sz += boot->ClusterSize) < dir->size; len++)
 435                                 cl = fat[cl].next;
 436                         clearchain(boot, fat, fat[cl].next);
 437                         fat[cl].next = CLUST_EOF;
 438                         fat[dir->head].length = len;
 439                         return FSFATMOD;
 440                 } else
 441                         return FSERROR;
 442         }
 443         return FSOK;
 444 }
 445
 446 /*
 447  * Read a directory and
 448  *   - resolve long name records
 449  *   - enter file and directory records into the parent's list
 450  *   - push directories onto the todo-stack
 451  */
 452 static int
 453 readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
 454     struct dosDirEntry *dir)
 455 {
 456         struct dosDirEntry dirent, *d;
 457         u_char *p, *vallfn, *invlfn, *empty;
 458         off_t off;
 459         int i, j, k, last;
 460         cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
 461         char *t;
 462         u_int lidx = 0;
 463         int shortSum;
 464         int mod = FSOK;
 465 #define THISMOD 0x8000                  /* Only used within this routine */
 466
 467         cl = dir->head;
 468         if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
 469                 /*
 470                  * Already handled somewhere else.
 471                  */
 472                 return FSOK;
 473         }
 474         shortSum = -1;
 475         vallfn = invlfn = empty = NULL;
 476         do {
 477                 if (!(boot->flags & FAT32) && !dir->parent) {
 478                         last = boot->bpbRootDirEnts * 32;
 479                         off = boot->bpbResSectors + boot->bpbFATs *
 480                             boot->FATsecs;
 481                 } else {
 482                         last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
 483                         off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
 484                 }
 485
 486                 off *= boot->bpbBytesPerSec;
 487                 if (lseek(f, off, SEEK_SET) != off
 488                     || read(f, buffer, last) != last) {
 489                         perr("Unable to read directory");
 490                         return FSFATAL;
 491                 }
 492                 last /= 32;
 493                 /*
 494                  * Check `.' and `..' entries here?                     XXX
 495                  */
 496                 for (p = buffer, i = 0; i < last; i++, p += 32) {
 497                         if (dir->fsckflags & DIREMPWARN) {
 498                                 *p = SLOT_EMPTY;
 499                                 continue;
 500                         }
 501
 502                         if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
 503                                 if (*p == SLOT_EMPTY) {
 504                                         dir->fsckflags |= DIREMPTY;
 505                                         empty = p;
 506                                         empcl = cl;
 507                                 }
 508                                 continue;
 509                         }
 510
 511                         if (dir->fsckflags & DIREMPTY) {
 512                                 if (!(dir->fsckflags & DIREMPWARN)) {
 513                                         pwarn("%s has entries after end of directory\n",
 514                                               fullpath(dir));
 515                                         if (ask(1, "Extend")) {
 516                                                 u_char *q;
 517
 518                                                 dir->fsckflags &= ~DIREMPTY;
 519                                                 if (delete(f, boot, fat,
 520                                                            empcl, empty - buffer,
 521                                                            cl, p - buffer, 1) == FSFATAL)
 522                                                         return FSFATAL;
 523                                                 q = empcl == cl ? empty : buffer;
 524                                                 for (; q < p; q += 32)
 525                                                         *q = SLOT_DELETED;
 526                                                 mod |= THISMOD|FSDIRMOD;
 527                                         } else if (ask(0, "Truncate"))
 528                                                 dir->fsckflags |= DIREMPWARN;
 529                                 }
 530                                 if (dir->fsckflags & DIREMPWARN) {
 531                                         *p = SLOT_DELETED;
 532                                         mod |= THISMOD|FSDIRMOD;
 533                                         continue;
 534                                 } else if (dir->fsckflags & DIREMPTY)
 535                                         mod |= FSERROR;
 536                                 empty = NULL;
 537                         }
 538
 539                         if (p[11] == ATTR_WIN95) {
 540                                 if (*p & LRFIRST) {
 541                                         if (shortSum != -1) {
 542                                                 if (!invlfn) {
 543                                                         invlfn = vallfn;
 544                                                         invcl = valcl;
 545                                                 }
 546                                         }
 547                                         memset(longName, 0, sizeof longName);
 548                                         shortSum = p[13];
 549                                         vallfn = p;
 550                                         valcl = cl;
 551                                 } else if (shortSum != p[13]
 552                                            || lidx != (*p & LRNOMASK)) {
 553                                         if (!invlfn) {
 554                                                 invlfn = vallfn;
 555                                                 invcl = valcl;
 556                                         }
 557                                         if (!invlfn) {
 558                                                 invlfn = p;
 559                                                 invcl = cl;
 560                                         }
 561                                         vallfn = NULL;
 562                                 }
 563                                 lidx = *p & LRNOMASK;
 564                                 t = longName + --lidx * 13;
 565                                 for (k = 1; k < 11 && t < longName +
 566                                     sizeof(longName); k += 2) {
 567                                         if (!p[k] && !p[k + 1])
 568                                                 break;
 569                                         *t++ = p[k];
 570                                         /*
 571                                          * Warn about those unusable chars in msdosfs here?     XXX
 572                                          */
 573                                         if (p[k + 1])
 574                                                 t[-1] = '?';
 575                                 }
 576                                 if (k >= 11)
 577                                         for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
 578                                                 if (!p[k] && !p[k + 1])
 579                                                         break;
 580                                                 *t++ = p[k];
 581                                                 if (p[k + 1])
 582                                                         t[-1] = '?';
 583                                         }
 584                                 if (k >= 26)
 585                                         for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
 586                                                 if (!p[k] && !p[k + 1])
 587                                                         break;
 588                                                 *t++ = p[k];
 589                                                 if (p[k + 1])
 590                                                         t[-1] = '?';
 591                                         }
 592                                 if (t >= longName + sizeof(longName)) {
 593                                         pwarn("long filename too long\n");
 594                                         if (!invlfn) {
 595                                                 invlfn = vallfn;
 596                                                 invcl = valcl;
 597                                         }
 598                                         vallfn = NULL;
 599                                 }
 600                                 if (p[26] | (p[27] << 8)) {
 601                                         pwarn("long filename record cluster start != 0\n");
 602                                         if (!invlfn) {
 603                                                 invlfn = vallfn;
 604                                                 invcl = cl;
 605                                         }
 606                                         vallfn = NULL;
 607                                 }
 608                                 continue;       /* long records don't carry further
 609                                                  * information */
 610                         }
 611
 612                         /*
 613                          * This is a standard msdosfs directory entry.
 614                          */
 615                         memset(&dirent, 0, sizeof dirent);
 616
 617                         /*
 618                          * it's a short name record, but we need to know
 619                          * more, so get the flags first.
 620                          */
 621                         dirent.flags = p[11];
 622
 623                         /*
 624                          * Translate from 850 to ISO here               XXX
 625                          */
 626                         for (j = 0; j < 8; j++)
 627                                 dirent.name[j] = p[j];
 628                         dirent.name[8] = '\0';
 629                         for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
 630                                 dirent.name[k] = '\0';
 631                         if (k < 0 || dirent.name[k] != '\0')
 632                                 k++;
 633                         if (dirent.name[0] == SLOT_E5)
 634                                 dirent.name[0] = 0xe5;
 635
 636                         if (dirent.flags & ATTR_VOLUME) {
 637                                 if (vallfn || invlfn) {
 638                                         mod |= removede(f, boot, fat,
 639                                                         invlfn ? invlfn : vallfn, p,
 640                                                         invlfn ? invcl : valcl, -1, 0,
 641                                                         fullpath(dir), 2);
 642                                         vallfn = NULL;
 643                                         invlfn = NULL;
 644                                 }
 645                                 continue;
 646                         }
 647
 648                         if (p[8] != ' ')
 649                                 dirent.name[k++] = '.';
 650                         for (j = 0; j < 3; j++)
 651                                 dirent.name[k++] = p[j+8];
 652                         dirent.name[k] = '\0';
 653                         for (k--; k >= 0 && dirent.name[k] == ' '; k--)
 654                                 dirent.name[k] = '\0';
 655
 656                         if (vallfn && shortSum != calcShortSum(p)) {
 657                                 if (!invlfn) {
 658                                         invlfn = vallfn;
 659                                         invcl = valcl;
 660                                 }
 661                                 vallfn = NULL;
 662                         }
 663                         dirent.head = p[26] | (p[27] << 8);
 664                         if (boot->ClustMask == CLUST32_MASK)
 665                                 dirent.head |= (p[20] << 16) | (p[21] << 24);
 666                         dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
 667                         if (vallfn) {
 668                                 strlcpy(dirent.lname, longName,
 669                                     sizeof(dirent.lname));
 670                                 longName[0] = '\0';
 671                                 shortSum = -1;
 672                         }
 673
 674                         dirent.parent = dir;
 675                         dirent.next = dir->child;
 676
 677                         if (invlfn) {
 678                                 mod |= k = removede(f, boot, fat,
 679                                                     invlfn, vallfn ? vallfn : p,
 680                                                     invcl, vallfn ? valcl : cl, cl,
 681                                                     fullpath(&dirent), 0);
 682                                 if (mod & FSFATAL)
 683                                         return FSFATAL;
 684                                 if (vallfn
 685                                     ? (valcl == cl && vallfn != buffer)
 686                                     : p != buffer)
 687                                         if (k & FSDIRMOD)
 688                                                 mod |= THISMOD;
 689                         }
 690
 691                         vallfn = NULL; /* not used any longer */
 692                         invlfn = NULL;
 693
 694                         if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
 695                                 if (dirent.head != 0) {
 696                                         pwarn("%s has clusters, but size 0\n",
 697                                               fullpath(&dirent));
 698                                         if (ask(1, "Drop allocated clusters")) {
 699                                                 p[26] = p[27] = 0;
 700                                                 if (boot->ClustMask == CLUST32_MASK)
 701                                                         p[20] = p[21] = 0;
 702                                                 clearchain(boot, fat, dirent.head);
 703                                                 dirent.head = 0;
 704                                                 mod |= THISMOD|FSDIRMOD|FSFATMOD;
 705                                         } else
 706                                                 mod |= FSERROR;
 707                                 }
 708                         } else if (dirent.head == 0
 709                                    && !strcmp(dirent.name, "..")
 710                                    && dir->parent                       /* XXX */
 711                                    && !dir->parent->parent) {
 712                                 /*
 713                                  *  Do nothing, the parent is the root
 714                                  */
 715                         } else if (dirent.head < CLUST_FIRST
 716                                    || dirent.head >= boot->NumClusters
 717                                    || fat[dirent.head].next == CLUST_FREE
 718                                    || (fat[dirent.head].next >= CLUST_RSRVD
 719                                        && fat[dirent.head].next < CLUST_EOFS)
 720                                    || fat[dirent.head].head != dirent.head) {
 721                                 if (dirent.head == 0)
 722                                         pwarn("%s has no clusters\n",
 723                                               fullpath(&dirent));
 724                                 else if (dirent.head < CLUST_FIRST
 725                                          || dirent.head >= boot->NumClusters)
 726                                         pwarn("%s starts with cluster out of range(%u)\n",
 727                                               fullpath(&dirent),
 728                                               dirent.head);
 729                                 else if (fat[dirent.head].next == CLUST_FREE)
 730                                         pwarn("%s starts with free cluster\n",
 731                                               fullpath(&dirent));
 732                                 else if (fat[dirent.head].next >= CLUST_RSRVD)
 733                                         pwarn("%s starts with cluster marked %s\n",
 734                                               fullpath(&dirent),
 735                                               rsrvdcltype(fat[dirent.head].next));
 736                                 else
 737                                         pwarn("%s doesn't start a cluster chain\n",
 738                                               fullpath(&dirent));
 739                                 if (dirent.flags & ATTR_DIRECTORY) {
 740                                         if (ask(0, "Remove")) {
 741                                                 *p = SLOT_DELETED;
 742                                                 mod |= THISMOD|FSDIRMOD;
 743                                         } else
 744                                                 mod |= FSERROR;
 745                                         continue;
 746                                 } else {
 747                                         if (ask(1, "Truncate")) {
 748                                                 p[28] = p[29] = p[30] = p[31] = 0;
 749                                                 p[26] = p[27] = 0;
 750                                                 if (boot->ClustMask == CLUST32_MASK)
 751                                                         p[20] = p[21] = 0;
 752                                                 dirent.size = 0;
 753                                                 mod |= THISMOD|FSDIRMOD;
 754                                         } else
 755                                                 mod |= FSERROR;
 756                                 }
 757                         }
 758
 759                         if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
 760                                 fat[dirent.head].flags |= FAT_USED;
 761
 762                         if (dirent.flags & ATTR_DIRECTORY) {
 763                                 /*
 764                                  * gather more info for directories
 765                                  */
 766                                 struct dirTodoNode *n;
 767
 768                                 if (dirent.size) {
 769                                         pwarn("Directory %s has size != 0\n",
 770                                               fullpath(&dirent));
 771                                         if (ask(1, "Correct")) {
 772                                                 p[28] = p[29] = p[30] = p[31] = 0;
 773                                                 dirent.size = 0;
 774                                                 mod |= THISMOD|FSDIRMOD;
 775                                         } else
 776                                                 mod |= FSERROR;
 777                                 }
 778                                 /*
 779                                  * handle `.' and `..' specially
 780                                  */
 781                                 if (strcmp(dirent.name, ".") == 0) {
 782                                         if (dirent.head != dir->head) {
 783                                                 pwarn("`.' entry in %s has incorrect start cluster\n",
 784                                                       fullpath(dir));
 785                                                 if (ask(1, "Correct")) {
 786                                                         dirent.head = dir->head;
 787                                                         p[26] = (u_char)dirent.head;
 788                                                         p[27] = (u_char)(dirent.head >> 8);
 789                                                         if (boot->ClustMask == CLUST32_MASK) {
 790                                                                 p[20] = (u_char)(dirent.head >> 16);
 791                                                                 p[21] = (u_char)(dirent.head >> 24);
 792                                                         }
 793                                                         mod |= THISMOD|FSDIRMOD;
 794                                                 } else
 795                                                         mod |= FSERROR;
 796                                         }
 797                                         continue;
 798                                 }
 799                                 if (strcmp(dirent.name, "..") == 0) {
 800                                         if (dir->parent) {              /* XXX */
 801                                                 if (!dir->parent->parent) {
 802                                                         if (dirent.head) {
 803                                                                 pwarn("`..' entry in %s has non-zero start cluster\n",
 804                                                                       fullpath(dir));
 805                                                                 if (ask(1, "Correct")) {
 806                                                                         dirent.head = 0;
 807                                                                         p[26] = p[27] = 0;
 808                                                                         if (boot->ClustMask == CLUST32_MASK)
 809                                                                                 p[20] = p[21] = 0;
 810                                                                         mod |= THISMOD|FSDIRMOD;
 811                                                                 } else
 812                                                                         mod |= FSERROR;
 813                                                         }
 814                                                 } else if (dirent.head != dir->parent->head) {
 815                                                         pwarn("`..' entry in %s has incorrect start cluster\n",
 816                                                               fullpath(dir));
 817                                                         if (ask(1, "Correct")) {
 818                                                                 dirent.head = dir->parent->head;
 819                                                                 p[26] = (u_char)dirent.head;
 820                                                                 p[27] = (u_char)(dirent.head >> 8);
 821                                                                 if (boot->ClustMask == CLUST32_MASK) {
 822                                                                         p[20] = (u_char)(dirent.head >> 16);
 823                                                                         p[21] = (u_char)(dirent.head >> 24);
 824                                                                 }
 825                                                                 mod |= THISMOD|FSDIRMOD;
 826                                                         } else
 827                                                                 mod |= FSERROR;
 828                                                 }
 829                                         }
 830                                         continue;
 831                                 }
 832
 833                                 /* create directory tree node */
 834                                 if (!(d = newDosDirEntry())) {
 835                                         perr("No space for directory");
 836                                         return FSFATAL;
 837                                 }
 838                                 memcpy(d, &dirent, sizeof(struct dosDirEntry));
 839                                 /* link it into the tree */
 840                                 dir->child = d;
 841
 842                                 /* Enter this directory into the todo list */
 843                                 if (!(n = newDirTodo())) {
 844                                         perr("No space for todo list");
 845                                         return FSFATAL;
 846                                 }
 847                                 n->next = pendingDirectories;
 848                                 n->dir = d;
 849                                 pendingDirectories = n;
 850                         } else {
 851                                 mod |= k = checksize(boot, fat, p, &dirent);
 852                                 if (k & FSDIRMOD)
 853                                         mod |= THISMOD;
 854                         }
 855                         boot->NumFiles++;
 856                 }
 857
 858                 if (!(boot->flags & FAT32) && !dir->parent)
 859                         break;
 860
 861                 if (mod & THISMOD) {
 862                         last *= 32;
 863                         if (lseek(f, off, SEEK_SET) != off
 864                             || write(f, buffer, last) != last) {
 865                                 perr("Unable to write directory");
 866                                 return FSFATAL;
 867                         }
 868                         mod &= ~THISMOD;
 869                 }
 870         } while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
 871         if (invlfn || vallfn)
 872                 mod |= removede(f, boot, fat,
 873                                 invlfn ? invlfn : vallfn, p,
 874                                 invlfn ? invcl : valcl, -1, 0,
 875                                 fullpath(dir), 1);
 876
 877         /* The root directory of non fat32 filesystems is in a special
 878          * area and may have been modified above without being written out.
 879          */
 880         if ((mod & FSDIRMOD) && !(boot->flags & FAT32) && !dir->parent) {
 881                 last *= 32;
 882                 if (lseek(f, off, SEEK_SET) != off
 883                     || write(f, buffer, last) != last) {
 884                         perr("Unable to write directory");
 885                         return FSFATAL;
 886                 }
 887                 mod &= ~THISMOD;
 888         }
 889         return mod & ~THISMOD;
 890 }
 891
 892 int
 893 handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
 894 {
 895         int mod;
 896
 897         mod = readDosDirSection(dosfs, boot, fat, rootDir);
 898         if (mod & FSFATAL)
 899                 return FSFATAL;
 900
 901         /*
 902          * process the directory todo list
 903          */
 904         while (pendingDirectories) {
 905                 struct dosDirEntry *dir = pendingDirectories->dir;
 906                 struct dirTodoNode *n = pendingDirectories->next;
 907
 908                 /*
 909                  * remove TODO entry now, the list might change during
 910                  * directory reads
 911                  */
 912                 freeDirTodo(pendingDirectories);
 913                 pendingDirectories = n;
 914
 915                 /*
 916                  * handle subdirectory
 917                  */
 918                 mod |= readDosDirSection(dosfs, boot, fat, dir);
 919                 if (mod & FSFATAL)
 920                         return FSFATAL;
 921         }
 922
 923         return mod;
 924 }
 925
 926 /*
 927  * Try to reconnect a FAT chain into dir
 928  */
 929 static u_char *lfbuf;
 930 static cl_t lfcl;
 931 static off_t lfoff;
 932
 933 int
 934 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
 935 {
 936         struct dosDirEntry d;
 937         int len;
 938         u_char *p;
 939
 940         if (!ask(1, "Reconnect"))
 941                 return FSERROR;
 942
 943         if (!lostDir) {
 944                 for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
 945                         if (!strcmp(lostDir->name, LOSTDIR))
 946                                 break;
 947                 }
 948                 if (!lostDir) {         /* Create LOSTDIR?              XXX */
 949                         pwarn("No %s directory\n", LOSTDIR);
 950                         return FSERROR;
 951                 }
 952         }
 953         if (!lfbuf) {
 954                 lfbuf = malloc(boot->ClusterSize);
 955                 if (!lfbuf) {
 956                         perr("No space for buffer");
 957                         return FSFATAL;
 958                 }
 959                 p = NULL;
 960         } else
 961                 p = lfbuf;
 962         while (1) {
 963                 if (p)
 964                         for (; p < lfbuf + boot->ClusterSize; p += 32)
 965                                 if (*p == SLOT_EMPTY
 966                                     || *p == SLOT_DELETED)
 967                                         break;
 968                 if (p && p < lfbuf + boot->ClusterSize)
 969                         break;
 970                 lfcl = p ? fat[lfcl].next : lostDir->head;
 971                 if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
 972                         /* Extend LOSTDIR?                              XXX */
 973                         pwarn("No space in %s\n", LOSTDIR);
 974                         return FSERROR;
 975                 }
 976                 lfoff = lfcl * boot->ClusterSize
 977                     + boot->ClusterOffset * boot->bpbBytesPerSec;
 978                 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
 979                     || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
 980                         perr("could not read LOST.DIR");
 981                         return FSFATAL;
 982                 }
 983                 p = lfbuf;
 984         }
 985
 986         boot->NumFiles++;
 987         /* Ensure uniqueness of entry here!                             XXX */
 988         memset(&d, 0, sizeof d);
 989         /* worst case -1 = 4294967295, 10 digits */
 990         len = snprintf(d.name, sizeof(d.name), "%u", head);
 991         d.flags = 0;
 992         d.head = head;
 993         d.size = fat[head].length * boot->ClusterSize;
 994
 995         memcpy(p, d.name, len);
 996         memset(p + len, ' ', 11 - len);
 997         memset(p + 11, 0, 32 - 11);
 998         p[26] = (u_char)d.head;
 999         p[27] = (u_char)(d.head >> 8);
1000         if (boot->ClustMask == CLUST32_MASK) {
1001                 p[20] = (u_char)(d.head >> 16);
1002                 p[21] = (u_char)(d.head >> 24);
1003         }
1004         p[28] = (u_char)d.size;
1005         p[29] = (u_char)(d.size >> 8);
1006         p[30] = (u_char)(d.size >> 16);
1007         p[31] = (u_char)(d.size >> 24);
1008         fat[head].flags |= FAT_USED;
1009         if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
1010             || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
1011                 perr("could not write LOST.DIR");
1012                 return FSFATAL;
1013         }
1014         return FSDIRMOD;
1015 }
1016
1017 void
1018 finishlf(void)
1019 {
1020         if (lfbuf)
1021                 free(lfbuf);
1022         lfbuf = NULL;
1023 }