1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2019 Google LLC 5 * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank 6 * Copyright (c) 1995 Martin Husemann 7 * Some structure declaration borrowed from Paul Popelka 8 * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 __RCSID("$NetBSD: dir.c,v 1.20 2006/06/05 16:51:18 christos Exp $"); 35 static const char rcsid[] = 36 "$FreeBSD$"; 37 #endif /* not lint */ 38 39 #include <assert.h> 40 #include <inttypes.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <ctype.h> 45 #include <unistd.h> 46 #include <time.h> 47 48 #include <sys/param.h> 49 50 #include "ext.h" 51 #include "fsutil.h" 52 53 #define SLOT_EMPTY 0x00 /* slot has never been used */ 54 #define SLOT_E5 0x05 /* the real value is 0xe5 */ 55 #define SLOT_DELETED 0xe5 /* file in this slot deleted */ 56 57 #define ATTR_NORMAL 0x00 /* normal file */ 58 #define ATTR_READONLY 0x01 /* file is readonly */ 59 #define ATTR_HIDDEN 0x02 /* file is hidden */ 60 #define ATTR_SYSTEM 0x04 /* file is a system file */ 61 #define ATTR_VOLUME 0x08 /* entry is a volume label */ 62 #define ATTR_DIRECTORY 0x10 /* entry is a directory name */ 63 #define ATTR_ARCHIVE 0x20 /* file is new or modified */ 64 65 #define ATTR_WIN95 0x0f /* long name record */ 66 67 /* 68 * This is the format of the contents of the deTime field in the direntry 69 * structure. 70 * We don't use bitfields because we don't know how compilers for 71 * arbitrary machines will lay them out. 72 */ 73 #define DT_2SECONDS_MASK 0x1F /* seconds divided by 2 */ 74 #define DT_2SECONDS_SHIFT 0 75 #define DT_MINUTES_MASK 0x7E0 /* minutes */ 76 #define DT_MINUTES_SHIFT 5 77 #define DT_HOURS_MASK 0xF800 /* hours */ 78 #define DT_HOURS_SHIFT 11 79 80 /* 81 * This is the format of the contents of the deDate field in the direntry 82 * structure. 83 */ 84 #define DD_DAY_MASK 0x1F /* day of month */ 85 #define DD_DAY_SHIFT 0 86 #define DD_MONTH_MASK 0x1E0 /* month */ 87 #define DD_MONTH_SHIFT 5 88 #define DD_YEAR_MASK 0xFE00 /* year - 1980 */ 89 #define DD_YEAR_SHIFT 9 90 91 92 /* dir.c */ 93 static struct dosDirEntry *newDosDirEntry(void); 94 static void freeDosDirEntry(struct dosDirEntry *); 95 static struct dirTodoNode *newDirTodo(void); 96 static void freeDirTodo(struct dirTodoNode *); 97 static char *fullpath(struct dosDirEntry *); 98 static u_char calcShortSum(u_char *); 99 static int delete(struct fat_descriptor *, cl_t, int, cl_t, int, int); 100 static int removede(struct fat_descriptor *, u_char *, u_char *, 101 cl_t, cl_t, cl_t, char *, int); 102 static int checksize(struct fat_descriptor *, u_char *, struct dosDirEntry *); 103 static int readDosDirSection(struct fat_descriptor *, struct dosDirEntry *); 104 105 /* 106 * Manage free dosDirEntry structures. 107 */ 108 static struct dosDirEntry *freede; 109 110 static struct dosDirEntry * 111 newDosDirEntry(void) 112 { 113 struct dosDirEntry *de; 114 115 if (!(de = freede)) { 116 if (!(de = malloc(sizeof *de))) 117 return (NULL); 118 } else 119 freede = de->next; 120 return de; 121 } 122 123 static void 124 freeDosDirEntry(struct dosDirEntry *de) 125 { 126 de->next = freede; 127 freede = de; 128 } 129 130 /* 131 * The same for dirTodoNode structures. 132 */ 133 static struct dirTodoNode *freedt; 134 135 static struct dirTodoNode * 136 newDirTodo(void) 137 { 138 struct dirTodoNode *dt; 139 140 if (!(dt = freedt)) { 141 if (!(dt = malloc(sizeof *dt))) 142 return 0; 143 } else 144 freedt = dt->next; 145 return dt; 146 } 147 148 static void 149 freeDirTodo(struct dirTodoNode *dt) 150 { 151 dt->next = freedt; 152 freedt = dt; 153 } 154 155 /* 156 * The stack of unread directories 157 */ 158 static struct dirTodoNode *pendingDirectories = NULL; 159 160 /* 161 * Return the full pathname for a directory entry. 162 */ 163 static char * 164 fullpath(struct dosDirEntry *dir) 165 { 166 static char namebuf[MAXPATHLEN + 1]; 167 char *cp, *np; 168 int nl; 169 170 cp = namebuf + sizeof namebuf; 171 *--cp = '\0'; 172 173 for(;;) { 174 np = dir->lname[0] ? dir->lname : dir->name; 175 nl = strlen(np); 176 if (cp <= namebuf + 1 + nl) { 177 *--cp = '?'; 178 break; 179 } 180 cp -= nl; 181 memcpy(cp, np, nl); 182 dir = dir->parent; 183 if (!dir) 184 break; 185 *--cp = '/'; 186 } 187 188 return cp; 189 } 190 191 /* 192 * Calculate a checksum over an 8.3 alias name 193 */ 194 static inline u_char 195 calcShortSum(u_char *p) 196 { 197 u_char sum = 0; 198 int i; 199 200 for (i = 0; i < 11; i++) { 201 sum = (sum << 7)|(sum >> 1); /* rotate right */ 202 sum += p[i]; 203 } 204 205 return sum; 206 } 207 208 /* 209 * Global variables temporarily used during a directory scan 210 */ 211 static char longName[DOSLONGNAMELEN] = ""; 212 static u_char *buffer = NULL; 213 static u_char *delbuf = NULL; 214 215 static struct dosDirEntry *rootDir; 216 static struct dosDirEntry *lostDir; 217 218 /* 219 * Init internal state for a new directory scan. 220 */ 221 int 222 resetDosDirSection(struct fat_descriptor *fat) 223 { 224 int rootdir_size, cluster_size; 225 int ret = FSOK; 226 size_t len; 227 struct bootblock *boot; 228 229 boot = fat_get_boot(fat); 230 231 rootdir_size = boot->bpbRootDirEnts * 32; 232 cluster_size = boot->bpbSecPerClust * boot->bpbBytesPerSec; 233 234 if ((buffer = malloc(len = MAX(rootdir_size, cluster_size))) == NULL) { 235 perr("No space for directory buffer (%zu)", len); 236 return FSFATAL; 237 } 238 239 if ((delbuf = malloc(len = cluster_size)) == NULL) { 240 free(buffer); 241 perr("No space for directory delbuf (%zu)", len); 242 return FSFATAL; 243 } 244 245 if ((rootDir = newDosDirEntry()) == NULL) { 246 free(buffer); 247 free(delbuf); 248 perr("No space for directory entry"); 249 return FSFATAL; 250 } 251 252 memset(rootDir, 0, sizeof *rootDir); 253 if (boot->flags & FAT32) { 254 if (!fat_is_cl_head(fat, boot->bpbRootClust)) { 255 pfatal("Root directory doesn't start a cluster chain"); 256 return FSFATAL; 257 } 258 rootDir->head = boot->bpbRootClust; 259 } 260 261 return ret; 262 } 263 264 /* 265 * Cleanup after a directory scan 266 */ 267 void 268 finishDosDirSection(void) 269 { 270 struct dirTodoNode *p, *np; 271 struct dosDirEntry *d, *nd; 272 273 for (p = pendingDirectories; p; p = np) { 274 np = p->next; 275 freeDirTodo(p); 276 } 277 pendingDirectories = NULL; 278 for (d = rootDir; d; d = nd) { 279 if ((nd = d->child) != NULL) { 280 d->child = 0; 281 continue; 282 } 283 if (!(nd = d->next)) 284 nd = d->parent; 285 freeDosDirEntry(d); 286 } 287 rootDir = lostDir = NULL; 288 free(buffer); 289 free(delbuf); 290 buffer = NULL; 291 delbuf = NULL; 292 } 293 294 /* 295 * Delete directory entries between startcl, startoff and endcl, endoff. 296 */ 297 static int 298 delete(struct fat_descriptor *fat, cl_t startcl, 299 int startoff, cl_t endcl, int endoff, int notlast) 300 { 301 u_char *s, *e; 302 off_t off; 303 int clsz, fd; 304 struct bootblock *boot; 305 306 boot = fat_get_boot(fat); 307 fd = fat_get_fd(fat); 308 clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec; 309 310 s = delbuf + startoff; 311 e = delbuf + clsz; 312 while (fat_is_valid_cl(fat, startcl)) { 313 if (startcl == endcl) { 314 if (notlast) 315 break; 316 e = delbuf + endoff; 317 } 318 off = (startcl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 319 320 off *= boot->bpbBytesPerSec; 321 if (lseek(fd, off, SEEK_SET) != off) { 322 perr("Unable to lseek to %" PRId64, off); 323 return FSFATAL; 324 } 325 if (read(fd, delbuf, clsz) != clsz) { 326 perr("Unable to read directory"); 327 return FSFATAL; 328 } 329 while (s < e) { 330 *s = SLOT_DELETED; 331 s += 32; 332 } 333 if (lseek(fd, off, SEEK_SET) != off) { 334 perr("Unable to lseek to %" PRId64, off); 335 return FSFATAL; 336 } 337 if (write(fd, delbuf, clsz) != clsz) { 338 perr("Unable to write directory"); 339 return FSFATAL; 340 } 341 if (startcl == endcl) 342 break; 343 startcl = fat_get_cl_next(fat, startcl); 344 s = delbuf; 345 } 346 return FSOK; 347 } 348 349 static int 350 removede(struct fat_descriptor *fat, u_char *start, 351 u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, 352 char *path, int type) 353 { 354 switch (type) { 355 case 0: 356 pwarn("Invalid long filename entry for %s\n", path); 357 break; 358 case 1: 359 pwarn("Invalid long filename entry at end of directory %s\n", 360 path); 361 break; 362 case 2: 363 pwarn("Invalid long filename entry for volume label\n"); 364 break; 365 } 366 if (ask(0, "Remove")) { 367 if (startcl != curcl) { 368 if (delete(fat, 369 startcl, start - buffer, 370 endcl, end - buffer, 371 endcl == curcl) == FSFATAL) 372 return FSFATAL; 373 start = buffer; 374 } 375 /* startcl is < CLUST_FIRST for !FAT32 root */ 376 if ((endcl == curcl) || (startcl < CLUST_FIRST)) 377 for (; start < end; start += 32) 378 *start = SLOT_DELETED; 379 return FSDIRMOD; 380 } 381 return FSERROR; 382 } 383 384 /* 385 * Check an in-memory file entry 386 */ 387 static int 388 checksize(struct fat_descriptor *fat, u_char *p, struct dosDirEntry *dir) 389 { 390 int ret = FSOK; 391 size_t chainsize; 392 u_int64_t physicalSize; 393 struct bootblock *boot; 394 395 boot = fat_get_boot(fat); 396 397 /* 398 * Check size on ordinary files 399 */ 400 if (dir->head == CLUST_FREE) { 401 physicalSize = 0; 402 } else { 403 if (!fat_is_valid_cl(fat, dir->head)) 404 return FSERROR; 405 ret = checkchain(fat, dir->head, &chainsize); 406 /* 407 * Upon return, chainsize would hold the chain length 408 * that checkchain() was able to validate, but if the user 409 * refused the proposed repair, it would be unsafe to 410 * proceed with directory entry fix, so bail out in that 411 * case. 412 */ 413 if (ret == FSERROR) { 414 return (FSERROR); 415 } 416 /* 417 * The maximum file size on FAT32 is 4GiB - 1, which 418 * will occupy a cluster chain of exactly 4GiB in 419 * size. On 32-bit platforms, since size_t is 32-bit, 420 * it would wrap back to 0. 421 */ 422 physicalSize = (u_int64_t)chainsize * boot->ClusterSize; 423 } 424 if (physicalSize < dir->size) { 425 pwarn("size of %s is %u, should at most be %ju\n", 426 fullpath(dir), dir->size, (uintmax_t)physicalSize); 427 if (ask(1, "Truncate")) { 428 dir->size = physicalSize; 429 p[28] = (u_char)physicalSize; 430 p[29] = (u_char)(physicalSize >> 8); 431 p[30] = (u_char)(physicalSize >> 16); 432 p[31] = (u_char)(physicalSize >> 24); 433 return FSDIRMOD; 434 } else 435 return FSERROR; 436 } else if (physicalSize - dir->size >= boot->ClusterSize) { 437 pwarn("%s has too many clusters allocated\n", 438 fullpath(dir)); 439 if (ask(1, "Drop superfluous clusters")) { 440 cl_t cl; 441 u_int32_t sz, len; 442 443 for (cl = dir->head, len = sz = 0; 444 (sz += boot->ClusterSize) < dir->size; len++) 445 cl = fat_get_cl_next(fat, cl); 446 clearchain(fat, fat_get_cl_next(fat, cl)); 447 ret = fat_set_cl_next(fat, cl, CLUST_EOF); 448 return (FSFATMOD | ret); 449 } else 450 return FSERROR; 451 } 452 return FSOK; 453 } 454 455 static const u_char dot_name[11] = ". "; 456 static const u_char dotdot_name[11] = ".. "; 457 458 /* 459 * Basic sanity check if the subdirectory have good '.' and '..' entries, 460 * and they are directory entries. Further sanity checks are performed 461 * when we traverse into it. 462 */ 463 static int 464 check_subdirectory(struct fat_descriptor *fat, struct dosDirEntry *dir) 465 { 466 u_char *buf, *cp; 467 off_t off; 468 cl_t cl; 469 int retval = FSOK; 470 int fd; 471 struct bootblock *boot; 472 473 boot = fat_get_boot(fat); 474 fd = fat_get_fd(fat); 475 476 cl = dir->head; 477 if (dir->parent && !fat_is_valid_cl(fat, cl)) { 478 return FSERROR; 479 } 480 481 if (!(boot->flags & FAT32) && !dir->parent) { 482 off = boot->bpbResSectors + boot->bpbFATs * 483 boot->FATsecs; 484 } else { 485 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 486 } 487 488 /* 489 * We only need to check the first two entries of the directory, 490 * which is found in the first sector of the directory entry, 491 * so read in only the first sector. 492 */ 493 buf = malloc(boot->bpbBytesPerSec); 494 if (buf == NULL) { 495 perr("No space for directory buffer (%u)", 496 boot->bpbBytesPerSec); 497 return FSFATAL; 498 } 499 500 off *= boot->bpbBytesPerSec; 501 if (lseek(fd, off, SEEK_SET) != off || 502 read(fd, buf, boot->bpbBytesPerSec) != (ssize_t)boot->bpbBytesPerSec) { 503 perr("Unable to read directory"); 504 free(buf); 505 return FSFATAL; 506 } 507 508 /* 509 * Both `.' and `..' must be present and be the first two entries 510 * and be ATTR_DIRECTORY of a valid subdirectory. 511 */ 512 cp = buf; 513 if (memcmp(cp, dot_name, sizeof(dot_name)) != 0 || 514 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 515 pwarn("%s: Incorrect `.' for %s.\n", __func__, dir->name); 516 retval |= FSERROR; 517 } 518 cp += 32; 519 if (memcmp(cp, dotdot_name, sizeof(dotdot_name)) != 0 || 520 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 521 pwarn("%s: Incorrect `..' for %s. \n", __func__, dir->name); 522 retval |= FSERROR; 523 } 524 525 free(buf); 526 return retval; 527 } 528 529 /* 530 * Read a directory and 531 * - resolve long name records 532 * - enter file and directory records into the parent's list 533 * - push directories onto the todo-stack 534 */ 535 static int 536 readDosDirSection(struct fat_descriptor *fat, struct dosDirEntry *dir) 537 { 538 struct bootblock *boot; 539 struct dosDirEntry dirent, *d; 540 u_char *p, *vallfn, *invlfn, *empty; 541 off_t off; 542 int fd, i, j, k, iosize, entries; 543 bool is_legacyroot; 544 cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0; 545 char *t; 546 u_int lidx = 0; 547 int shortSum; 548 int mod = FSOK; 549 size_t dirclusters; 550 #define THISMOD 0x8000 /* Only used within this routine */ 551 552 boot = fat_get_boot(fat); 553 fd = fat_get_fd(fat); 554 555 cl = dir->head; 556 if (dir->parent && (!fat_is_valid_cl(fat, cl))) { 557 /* 558 * Already handled somewhere else. 559 */ 560 return FSOK; 561 } 562 shortSum = -1; 563 vallfn = invlfn = empty = NULL; 564 565 /* 566 * If we are checking the legacy root (for FAT12/FAT16), 567 * we will operate on the whole directory; otherwise, we 568 * will operate on one cluster at a time, and also take 569 * this opportunity to examine the chain. 570 * 571 * Derive how many entries we are going to encounter from 572 * the I/O size. 573 */ 574 is_legacyroot = (dir->parent == NULL && !(boot->flags & FAT32)); 575 if (is_legacyroot) { 576 iosize = boot->bpbRootDirEnts * 32; 577 entries = boot->bpbRootDirEnts; 578 } else { 579 iosize = boot->bpbSecPerClust * boot->bpbBytesPerSec; 580 entries = iosize / 32; 581 mod |= checkchain(fat, dir->head, &dirclusters); 582 } 583 584 do { 585 if (is_legacyroot) { 586 /* 587 * Special case for FAT12/FAT16 root -- read 588 * in the whole root directory. 589 */ 590 off = boot->bpbResSectors + boot->bpbFATs * 591 boot->FATsecs; 592 } else { 593 /* 594 * Otherwise, read in a cluster of the 595 * directory. 596 */ 597 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 598 } 599 600 off *= boot->bpbBytesPerSec; 601 if (lseek(fd, off, SEEK_SET) != off || 602 read(fd, buffer, iosize) != iosize) { 603 perr("Unable to read directory"); 604 return FSFATAL; 605 } 606 607 for (p = buffer, i = 0; i < entries; i++, p += 32) { 608 if (dir->fsckflags & DIREMPWARN) { 609 *p = SLOT_EMPTY; 610 continue; 611 } 612 613 if (*p == SLOT_EMPTY || *p == SLOT_DELETED) { 614 if (*p == SLOT_EMPTY) { 615 dir->fsckflags |= DIREMPTY; 616 empty = p; 617 empcl = cl; 618 } 619 continue; 620 } 621 622 if (dir->fsckflags & DIREMPTY) { 623 if (!(dir->fsckflags & DIREMPWARN)) { 624 pwarn("%s has entries after end of directory\n", 625 fullpath(dir)); 626 if (ask(1, "Extend")) { 627 u_char *q; 628 629 dir->fsckflags &= ~DIREMPTY; 630 if (delete(fat, 631 empcl, empty - buffer, 632 cl, p - buffer, 1) == FSFATAL) 633 return FSFATAL; 634 q = ((empcl == cl) ? empty : buffer); 635 assert(q != NULL); 636 for (; q < p; q += 32) 637 *q = SLOT_DELETED; 638 mod |= THISMOD|FSDIRMOD; 639 } else if (ask(0, "Truncate")) 640 dir->fsckflags |= DIREMPWARN; 641 } 642 if (dir->fsckflags & DIREMPWARN) { 643 *p = SLOT_DELETED; 644 mod |= THISMOD|FSDIRMOD; 645 continue; 646 } else if (dir->fsckflags & DIREMPTY) 647 mod |= FSERROR; 648 empty = NULL; 649 } 650 651 if (p[11] == ATTR_WIN95) { 652 if (*p & LRFIRST) { 653 if (shortSum != -1) { 654 if (!invlfn) { 655 invlfn = vallfn; 656 invcl = valcl; 657 } 658 } 659 memset(longName, 0, sizeof longName); 660 shortSum = p[13]; 661 vallfn = p; 662 valcl = cl; 663 } else if (shortSum != p[13] 664 || lidx != (*p & LRNOMASK)) { 665 if (!invlfn) { 666 invlfn = vallfn; 667 invcl = valcl; 668 } 669 if (!invlfn) { 670 invlfn = p; 671 invcl = cl; 672 } 673 vallfn = NULL; 674 } 675 lidx = *p & LRNOMASK; 676 if (lidx == 0) { 677 pwarn("invalid long name\n"); 678 if (!invlfn) { 679 invlfn = vallfn; 680 invcl = valcl; 681 } 682 vallfn = NULL; 683 continue; 684 } 685 t = longName + --lidx * 13; 686 for (k = 1; k < 11 && t < longName + 687 sizeof(longName); k += 2) { 688 if (!p[k] && !p[k + 1]) 689 break; 690 *t++ = p[k]; 691 /* 692 * Warn about those unusable chars in msdosfs here? XXX 693 */ 694 if (p[k + 1]) 695 t[-1] = '?'; 696 } 697 if (k >= 11) 698 for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) { 699 if (!p[k] && !p[k + 1]) 700 break; 701 *t++ = p[k]; 702 if (p[k + 1]) 703 t[-1] = '?'; 704 } 705 if (k >= 26) 706 for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) { 707 if (!p[k] && !p[k + 1]) 708 break; 709 *t++ = p[k]; 710 if (p[k + 1]) 711 t[-1] = '?'; 712 } 713 if (t >= longName + sizeof(longName)) { 714 pwarn("long filename too long\n"); 715 if (!invlfn) { 716 invlfn = vallfn; 717 invcl = valcl; 718 } 719 vallfn = NULL; 720 } 721 if (p[26] | (p[27] << 8)) { 722 pwarn("long filename record cluster start != 0\n"); 723 if (!invlfn) { 724 invlfn = vallfn; 725 invcl = cl; 726 } 727 vallfn = NULL; 728 } 729 continue; /* long records don't carry further 730 * information */ 731 } 732 733 /* 734 * This is a standard msdosfs directory entry. 735 */ 736 memset(&dirent, 0, sizeof dirent); 737 738 /* 739 * it's a short name record, but we need to know 740 * more, so get the flags first. 741 */ 742 dirent.flags = p[11]; 743 744 /* 745 * Translate from 850 to ISO here XXX 746 */ 747 for (j = 0; j < 8; j++) 748 dirent.name[j] = p[j]; 749 dirent.name[8] = '\0'; 750 for (k = 7; k >= 0 && dirent.name[k] == ' '; k--) 751 dirent.name[k] = '\0'; 752 if (k < 0 || dirent.name[k] != '\0') 753 k++; 754 if (dirent.name[0] == SLOT_E5) 755 dirent.name[0] = 0xe5; 756 757 if (dirent.flags & ATTR_VOLUME) { 758 if (vallfn || invlfn) { 759 mod |= removede(fat, 760 invlfn ? invlfn : vallfn, p, 761 invlfn ? invcl : valcl, -1, 0, 762 fullpath(dir), 2); 763 vallfn = NULL; 764 invlfn = NULL; 765 } 766 continue; 767 } 768 769 if (p[8] != ' ') 770 dirent.name[k++] = '.'; 771 for (j = 0; j < 3; j++) 772 dirent.name[k++] = p[j+8]; 773 dirent.name[k] = '\0'; 774 for (k--; k >= 0 && dirent.name[k] == ' '; k--) 775 dirent.name[k] = '\0'; 776 777 if (vallfn && shortSum != calcShortSum(p)) { 778 if (!invlfn) { 779 invlfn = vallfn; 780 invcl = valcl; 781 } 782 vallfn = NULL; 783 } 784 dirent.head = p[26] | (p[27] << 8); 785 if (boot->ClustMask == CLUST32_MASK) 786 dirent.head |= (p[20] << 16) | (p[21] << 24); 787 dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24); 788 if (vallfn) { 789 strlcpy(dirent.lname, longName, 790 sizeof(dirent.lname)); 791 longName[0] = '\0'; 792 shortSum = -1; 793 } 794 795 dirent.parent = dir; 796 dirent.next = dir->child; 797 798 if (invlfn) { 799 mod |= k = removede(fat, 800 invlfn, vallfn ? vallfn : p, 801 invcl, vallfn ? valcl : cl, cl, 802 fullpath(&dirent), 0); 803 if (mod & FSFATAL) 804 return FSFATAL; 805 if (vallfn 806 ? (valcl == cl && vallfn != buffer) 807 : p != buffer) 808 if (k & FSDIRMOD) 809 mod |= THISMOD; 810 } 811 812 vallfn = NULL; /* not used any longer */ 813 invlfn = NULL; 814 815 /* 816 * Check if the directory entry is sane. 817 * 818 * '.' and '..' are skipped, their sanity is 819 * checked somewhere else. 820 * 821 * For everything else, check if we have a new, 822 * valid cluster chain (beginning of a file or 823 * directory that was never previously claimed 824 * by another file) when it's a non-empty file 825 * or a directory. The sanity of the cluster 826 * chain is checked at a later time when we 827 * traverse into the directory, or examine the 828 * file's directory entry. 829 * 830 * The only possible fix is to delete the entry 831 * if it's a directory; for file, we have to 832 * truncate the size to 0. 833 */ 834 if (!(dirent.flags & ATTR_DIRECTORY) || 835 (strcmp(dirent.name, ".") != 0 && 836 strcmp(dirent.name, "..") != 0)) { 837 if ((dirent.size != 0 || (dirent.flags & ATTR_DIRECTORY)) && 838 ((!fat_is_valid_cl(fat, dirent.head) || 839 !fat_is_cl_head(fat, dirent.head)))) { 840 if (!fat_is_valid_cl(fat, dirent.head)) { 841 pwarn("%s starts with cluster out of range(%u)\n", 842 fullpath(&dirent), 843 dirent.head); 844 } else { 845 pwarn("%s doesn't start a new cluster chain\n", 846 fullpath(&dirent)); 847 } 848 849 if (dirent.flags & ATTR_DIRECTORY) { 850 if (ask(0, "Remove")) { 851 *p = SLOT_DELETED; 852 mod |= THISMOD|FSDIRMOD; 853 } else 854 mod |= FSERROR; 855 continue; 856 } else { 857 if (ask(1, "Truncate")) { 858 p[28] = p[29] = p[30] = p[31] = 0; 859 p[26] = p[27] = 0; 860 if (boot->ClustMask == CLUST32_MASK) 861 p[20] = p[21] = 0; 862 dirent.size = 0; 863 dirent.head = 0; 864 mod |= THISMOD|FSDIRMOD; 865 } else 866 mod |= FSERROR; 867 } 868 } 869 } 870 if (dirent.flags & ATTR_DIRECTORY) { 871 /* 872 * gather more info for directories 873 */ 874 struct dirTodoNode *n; 875 876 if (dirent.size) { 877 pwarn("Directory %s has size != 0\n", 878 fullpath(&dirent)); 879 if (ask(1, "Correct")) { 880 p[28] = p[29] = p[30] = p[31] = 0; 881 dirent.size = 0; 882 mod |= THISMOD|FSDIRMOD; 883 } else 884 mod |= FSERROR; 885 } 886 /* 887 * handle `.' and `..' specially 888 */ 889 if (strcmp(dirent.name, ".") == 0) { 890 if (dirent.head != dir->head) { 891 pwarn("`.' entry in %s has incorrect start cluster\n", 892 fullpath(dir)); 893 if (ask(1, "Correct")) { 894 dirent.head = dir->head; 895 p[26] = (u_char)dirent.head; 896 p[27] = (u_char)(dirent.head >> 8); 897 if (boot->ClustMask == CLUST32_MASK) { 898 p[20] = (u_char)(dirent.head >> 16); 899 p[21] = (u_char)(dirent.head >> 24); 900 } 901 mod |= THISMOD|FSDIRMOD; 902 } else 903 mod |= FSERROR; 904 } 905 continue; 906 } else if (strcmp(dirent.name, "..") == 0) { 907 if (dir->parent) { /* XXX */ 908 if (!dir->parent->parent) { 909 if (dirent.head) { 910 pwarn("`..' entry in %s has non-zero start cluster\n", 911 fullpath(dir)); 912 if (ask(1, "Correct")) { 913 dirent.head = 0; 914 p[26] = p[27] = 0; 915 if (boot->ClustMask == CLUST32_MASK) 916 p[20] = p[21] = 0; 917 mod |= THISMOD|FSDIRMOD; 918 } else 919 mod |= FSERROR; 920 } 921 } else if (dirent.head != dir->parent->head) { 922 pwarn("`..' entry in %s has incorrect start cluster\n", 923 fullpath(dir)); 924 if (ask(1, "Correct")) { 925 dirent.head = dir->parent->head; 926 p[26] = (u_char)dirent.head; 927 p[27] = (u_char)(dirent.head >> 8); 928 if (boot->ClustMask == CLUST32_MASK) { 929 p[20] = (u_char)(dirent.head >> 16); 930 p[21] = (u_char)(dirent.head >> 24); 931 } 932 mod |= THISMOD|FSDIRMOD; 933 } else 934 mod |= FSERROR; 935 } 936 } 937 continue; 938 } else { 939 /* 940 * Only one directory entry can point 941 * to dir->head, it's '.'. 942 */ 943 if (dirent.head == dir->head) { 944 pwarn("%s entry in %s has incorrect start cluster\n", 945 dirent.name, fullpath(dir)); 946 if (ask(1, "Remove")) { 947 *p = SLOT_DELETED; 948 mod |= THISMOD|FSDIRMOD; 949 } else 950 mod |= FSERROR; 951 continue; 952 } else if ((check_subdirectory(fat, 953 &dirent) & FSERROR) == FSERROR) { 954 /* 955 * A subdirectory should have 956 * a dot (.) entry and a dot-dot 957 * (..) entry of ATTR_DIRECTORY, 958 * we will inspect further when 959 * traversing into it. 960 */ 961 if (ask(1, "Remove")) { 962 *p = SLOT_DELETED; 963 mod |= THISMOD|FSDIRMOD; 964 } else 965 mod |= FSERROR; 966 continue; 967 } 968 } 969 970 /* create directory tree node */ 971 if (!(d = newDosDirEntry())) { 972 perr("No space for directory"); 973 return FSFATAL; 974 } 975 memcpy(d, &dirent, sizeof(struct dosDirEntry)); 976 /* link it into the tree */ 977 dir->child = d; 978 979 /* Enter this directory into the todo list */ 980 if (!(n = newDirTodo())) { 981 perr("No space for todo list"); 982 return FSFATAL; 983 } 984 n->next = pendingDirectories; 985 n->dir = d; 986 pendingDirectories = n; 987 } else { 988 mod |= k = checksize(fat, p, &dirent); 989 if (k & FSDIRMOD) 990 mod |= THISMOD; 991 } 992 boot->NumFiles++; 993 } 994 995 if (is_legacyroot) { 996 /* 997 * Don't bother to write back right now because 998 * we may continue to make modification to the 999 * non-FAT32 root directory below. 1000 */ 1001 break; 1002 } else if (mod & THISMOD) { 1003 if (lseek(fd, off, SEEK_SET) != off 1004 || write(fd, buffer, iosize) != iosize) { 1005 perr("Unable to write directory"); 1006 return FSFATAL; 1007 } 1008 mod &= ~THISMOD; 1009 } 1010 } while (fat_is_valid_cl(fat, (cl = fat_get_cl_next(fat, cl)))); 1011 if (invlfn || vallfn) 1012 mod |= removede(fat, 1013 invlfn ? invlfn : vallfn, p, 1014 invlfn ? invcl : valcl, -1, 0, 1015 fullpath(dir), 1); 1016 1017 /* 1018 * The root directory of non-FAT32 filesystems is in a special 1019 * area and may have been modified above removede() without 1020 * being written out. 1021 */ 1022 if ((mod & FSDIRMOD) && is_legacyroot) { 1023 if (lseek(fd, off, SEEK_SET) != off 1024 || write(fd, buffer, iosize) != iosize) { 1025 perr("Unable to write directory"); 1026 return FSFATAL; 1027 } 1028 mod &= ~THISMOD; 1029 } 1030 return mod & ~THISMOD; 1031 } 1032 1033 int 1034 handleDirTree(struct fat_descriptor *fat) 1035 { 1036 int mod; 1037 1038 mod = readDosDirSection(fat, rootDir); 1039 if (mod & FSFATAL) 1040 return FSFATAL; 1041 1042 /* 1043 * process the directory todo list 1044 */ 1045 while (pendingDirectories) { 1046 struct dosDirEntry *dir = pendingDirectories->dir; 1047 struct dirTodoNode *n = pendingDirectories->next; 1048 1049 /* 1050 * remove TODO entry now, the list might change during 1051 * directory reads 1052 */ 1053 freeDirTodo(pendingDirectories); 1054 pendingDirectories = n; 1055 1056 /* 1057 * handle subdirectory 1058 */ 1059 mod |= readDosDirSection(fat, dir); 1060 if (mod & FSFATAL) 1061 return FSFATAL; 1062 } 1063 1064 return mod; 1065 } 1066 1067 /* 1068 * Try to reconnect a FAT chain into dir 1069 */ 1070 static u_char *lfbuf; 1071 static cl_t lfcl; 1072 static off_t lfoff; 1073 1074 int 1075 reconnect(struct fat_descriptor *fat, cl_t head, size_t length) 1076 { 1077 struct bootblock *boot = fat_get_boot(fat); 1078 struct dosDirEntry d; 1079 int len, dosfs; 1080 u_char *p; 1081 1082 dosfs = fat_get_fd(fat); 1083 1084 if (!ask(1, "Reconnect")) 1085 return FSERROR; 1086 1087 if (!lostDir) { 1088 for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) { 1089 if (!strcmp(lostDir->name, LOSTDIR)) 1090 break; 1091 } 1092 if (!lostDir) { /* Create LOSTDIR? XXX */ 1093 pwarn("No %s directory\n", LOSTDIR); 1094 return FSERROR; 1095 } 1096 } 1097 if (!lfbuf) { 1098 lfbuf = malloc(boot->ClusterSize); 1099 if (!lfbuf) { 1100 perr("No space for buffer"); 1101 return FSFATAL; 1102 } 1103 p = NULL; 1104 } else 1105 p = lfbuf; 1106 while (1) { 1107 if (p) 1108 for (; p < lfbuf + boot->ClusterSize; p += 32) 1109 if (*p == SLOT_EMPTY 1110 || *p == SLOT_DELETED) 1111 break; 1112 if (p && p < lfbuf + boot->ClusterSize) 1113 break; 1114 lfcl = p ? fat_get_cl_next(fat, lfcl) : lostDir->head; 1115 if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) { 1116 /* Extend LOSTDIR? XXX */ 1117 pwarn("No space in %s\n", LOSTDIR); 1118 lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0; 1119 return FSERROR; 1120 } 1121 lfoff = (lfcl - CLUST_FIRST) * boot->ClusterSize 1122 + boot->FirstCluster * boot->bpbBytesPerSec; 1123 1124 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1125 || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1126 perr("could not read LOST.DIR"); 1127 return FSFATAL; 1128 } 1129 p = lfbuf; 1130 } 1131 1132 boot->NumFiles++; 1133 /* Ensure uniqueness of entry here! XXX */ 1134 memset(&d, 0, sizeof d); 1135 /* worst case -1 = 4294967295, 10 digits */ 1136 len = snprintf(d.name, sizeof(d.name), "%u", head); 1137 d.flags = 0; 1138 d.head = head; 1139 d.size = length * boot->ClusterSize; 1140 1141 memcpy(p, d.name, len); 1142 memset(p + len, ' ', 11 - len); 1143 memset(p + 11, 0, 32 - 11); 1144 p[26] = (u_char)d.head; 1145 p[27] = (u_char)(d.head >> 8); 1146 if (boot->ClustMask == CLUST32_MASK) { 1147 p[20] = (u_char)(d.head >> 16); 1148 p[21] = (u_char)(d.head >> 24); 1149 } 1150 p[28] = (u_char)d.size; 1151 p[29] = (u_char)(d.size >> 8); 1152 p[30] = (u_char)(d.size >> 16); 1153 p[31] = (u_char)(d.size >> 24); 1154 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1155 || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1156 perr("could not write LOST.DIR"); 1157 return FSFATAL; 1158 } 1159 return FSDIRMOD; 1160 } 1161 1162 void 1163 finishlf(void) 1164 { 1165 if (lfbuf) 1166 free(lfbuf); 1167 lfbuf = NULL; 1168 } 1169