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