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 #include <assert.h> 32 #include <inttypes.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <ctype.h> 37 #include <unistd.h> 38 #include <time.h> 39 40 #include <sys/param.h> 41 42 #include "ext.h" 43 #include "fsutil.h" 44 45 #define SLOT_EMPTY 0x00 /* slot has never been used */ 46 #define SLOT_E5 0x05 /* the real value is 0xe5 */ 47 #define SLOT_DELETED 0xe5 /* file in this slot deleted */ 48 49 #define ATTR_NORMAL 0x00 /* normal file */ 50 #define ATTR_READONLY 0x01 /* file is readonly */ 51 #define ATTR_HIDDEN 0x02 /* file is hidden */ 52 #define ATTR_SYSTEM 0x04 /* file is a system file */ 53 #define ATTR_VOLUME 0x08 /* entry is a volume label */ 54 #define ATTR_DIRECTORY 0x10 /* entry is a directory name */ 55 #define ATTR_ARCHIVE 0x20 /* file is new or modified */ 56 57 #define ATTR_WIN95 0x0f /* long name record */ 58 59 /* 60 * This is the format of the contents of the deTime field in the direntry 61 * structure. 62 * We don't use bitfields because we don't know how compilers for 63 * arbitrary machines will lay them out. 64 */ 65 #define DT_2SECONDS_MASK 0x1F /* seconds divided by 2 */ 66 #define DT_2SECONDS_SHIFT 0 67 #define DT_MINUTES_MASK 0x7E0 /* minutes */ 68 #define DT_MINUTES_SHIFT 5 69 #define DT_HOURS_MASK 0xF800 /* hours */ 70 #define DT_HOURS_SHIFT 11 71 72 /* 73 * This is the format of the contents of the deDate field in the direntry 74 * structure. 75 */ 76 #define DD_DAY_MASK 0x1F /* day of month */ 77 #define DD_DAY_SHIFT 0 78 #define DD_MONTH_MASK 0x1E0 /* month */ 79 #define DD_MONTH_SHIFT 5 80 #define DD_YEAR_MASK 0xFE00 /* year - 1980 */ 81 #define DD_YEAR_SHIFT 9 82 83 84 /* dir.c */ 85 static struct dosDirEntry *newDosDirEntry(void); 86 static void freeDosDirEntry(struct dosDirEntry *); 87 static struct dirTodoNode *newDirTodo(void); 88 static void freeDirTodo(struct dirTodoNode *); 89 static char *fullpath(struct dosDirEntry *); 90 static u_char calcShortSum(u_char *); 91 static int delete(struct fat_descriptor *, cl_t, int, cl_t, int, int); 92 static int removede(struct fat_descriptor *, u_char *, u_char *, 93 cl_t, cl_t, cl_t, char *, int); 94 static int checksize(struct fat_descriptor *, u_char *, struct dosDirEntry *); 95 static int readDosDirSection(struct fat_descriptor *, struct dosDirEntry *); 96 97 /* 98 * Manage free dosDirEntry structures. 99 */ 100 static struct dosDirEntry *freede; 101 102 static struct dosDirEntry * 103 newDosDirEntry(void) 104 { 105 struct dosDirEntry *de; 106 107 if (!(de = freede)) { 108 if (!(de = malloc(sizeof(*de)))) 109 return (NULL); 110 } else 111 freede = de->next; 112 return de; 113 } 114 115 static void 116 freeDosDirEntry(struct dosDirEntry *de) 117 { 118 de->next = freede; 119 freede = de; 120 } 121 122 /* 123 * The same for dirTodoNode structures. 124 */ 125 static struct dirTodoNode *freedt; 126 127 static struct dirTodoNode * 128 newDirTodo(void) 129 { 130 struct dirTodoNode *dt; 131 132 if (!(dt = freedt)) { 133 if (!(dt = malloc(sizeof(*dt)))) 134 return 0; 135 } else 136 freedt = dt->next; 137 return dt; 138 } 139 140 static void 141 freeDirTodo(struct dirTodoNode *dt) 142 { 143 dt->next = freedt; 144 freedt = dt; 145 } 146 147 /* 148 * The stack of unread directories 149 */ 150 static struct dirTodoNode *pendingDirectories = NULL; 151 152 /* 153 * Return the full pathname for a directory entry. 154 */ 155 static char * 156 fullpath(struct dosDirEntry *dir) 157 { 158 static char namebuf[MAXPATHLEN + 1]; 159 char *cp, *np; 160 int nl; 161 162 cp = namebuf + sizeof namebuf; 163 *--cp = '\0'; 164 165 for(;;) { 166 np = dir->lname[0] ? dir->lname : dir->name; 167 nl = strlen(np); 168 if (cp <= namebuf + 1 + nl) { 169 *--cp = '?'; 170 break; 171 } 172 cp -= nl; 173 memcpy(cp, np, nl); 174 dir = dir->parent; 175 if (!dir) 176 break; 177 *--cp = '/'; 178 } 179 180 return cp; 181 } 182 183 /* 184 * Calculate a checksum over an 8.3 alias name 185 */ 186 static inline u_char 187 calcShortSum(u_char *p) 188 { 189 u_char sum = 0; 190 int i; 191 192 for (i = 0; i < 11; i++) { 193 sum = (sum << 7)|(sum >> 1); /* rotate right */ 194 sum += p[i]; 195 } 196 197 return sum; 198 } 199 200 /* 201 * Global variables temporarily used during a directory scan 202 */ 203 static char longName[DOSLONGNAMELEN] = ""; 204 static u_char *buffer = NULL; 205 static u_char *delbuf = NULL; 206 207 static struct dosDirEntry *rootDir; 208 static struct dosDirEntry *lostDir; 209 210 /* 211 * Init internal state for a new directory scan. 212 */ 213 int 214 resetDosDirSection(struct fat_descriptor *fat) 215 { 216 int rootdir_size, cluster_size; 217 int ret = FSOK; 218 size_t len; 219 struct bootblock *boot; 220 221 boot = fat_get_boot(fat); 222 223 rootdir_size = boot->bpbRootDirEnts * 32; 224 cluster_size = boot->bpbSecPerClust * boot->bpbBytesPerSec; 225 226 if ((buffer = malloc(len = MAX(rootdir_size, cluster_size))) == NULL) { 227 perr("No space for directory buffer (%zu)", len); 228 return FSFATAL; 229 } 230 231 if ((delbuf = malloc(len = cluster_size)) == NULL) { 232 free(buffer); 233 perr("No space for directory delbuf (%zu)", len); 234 return FSFATAL; 235 } 236 237 if ((rootDir = newDosDirEntry()) == NULL) { 238 free(buffer); 239 free(delbuf); 240 perr("No space for directory entry"); 241 return FSFATAL; 242 } 243 244 memset(rootDir, 0, sizeof *rootDir); 245 if (boot->flags & FAT32) { 246 if (!fat_is_cl_head(fat, boot->bpbRootClust)) { 247 free(buffer); 248 free(delbuf); 249 pfatal("Root directory doesn't start a cluster chain"); 250 return FSFATAL; 251 } 252 rootDir->head = boot->bpbRootClust; 253 } 254 255 return ret; 256 } 257 258 /* 259 * Cleanup after a directory scan 260 */ 261 void 262 finishDosDirSection(void) 263 { 264 struct dirTodoNode *p, *np; 265 struct dosDirEntry *d, *nd; 266 267 for (p = pendingDirectories; p; p = np) { 268 np = p->next; 269 freeDirTodo(p); 270 } 271 pendingDirectories = NULL; 272 for (d = rootDir; d; d = nd) { 273 if ((nd = d->child) != NULL) { 274 d->child = 0; 275 continue; 276 } 277 if (!(nd = d->next)) 278 nd = d->parent; 279 freeDosDirEntry(d); 280 } 281 rootDir = lostDir = NULL; 282 free(buffer); 283 free(delbuf); 284 buffer = NULL; 285 delbuf = NULL; 286 } 287 288 /* 289 * Delete directory entries between startcl, startoff and endcl, endoff. 290 */ 291 static int 292 delete(struct fat_descriptor *fat, cl_t startcl, 293 int startoff, cl_t endcl, int endoff, int notlast) 294 { 295 u_char *s, *e; 296 off_t off; 297 int clsz, fd; 298 struct bootblock *boot; 299 300 boot = fat_get_boot(fat); 301 fd = fat_get_fd(fat); 302 clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec; 303 304 s = delbuf + startoff; 305 e = delbuf + clsz; 306 while (fat_is_valid_cl(fat, startcl)) { 307 if (startcl == endcl) { 308 if (notlast) 309 break; 310 e = delbuf + endoff; 311 } 312 off = (startcl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 313 314 off *= boot->bpbBytesPerSec; 315 if (lseek(fd, off, SEEK_SET) != off) { 316 perr("Unable to lseek to %" PRId64, off); 317 return FSFATAL; 318 } 319 if (read(fd, delbuf, clsz) != clsz) { 320 perr("Unable to read directory"); 321 return FSFATAL; 322 } 323 while (s < e) { 324 *s = SLOT_DELETED; 325 s += 32; 326 } 327 if (lseek(fd, off, SEEK_SET) != off) { 328 perr("Unable to lseek to %" PRId64, off); 329 return FSFATAL; 330 } 331 if (write(fd, delbuf, clsz) != clsz) { 332 perr("Unable to write directory"); 333 return FSFATAL; 334 } 335 if (startcl == endcl) 336 break; 337 startcl = fat_get_cl_next(fat, startcl); 338 s = delbuf; 339 } 340 return FSOK; 341 } 342 343 static int 344 removede(struct fat_descriptor *fat, u_char *start, 345 u_char *end, cl_t startcl, cl_t endcl, cl_t curcl, 346 char *path, int type) 347 { 348 switch (type) { 349 case 0: 350 pwarn("Invalid long filename entry for %s\n", path); 351 break; 352 case 1: 353 pwarn("Invalid long filename entry at end of directory %s\n", 354 path); 355 break; 356 case 2: 357 pwarn("Invalid long filename entry for volume label\n"); 358 break; 359 } 360 if (ask(0, "Remove")) { 361 if (startcl != curcl) { 362 if (delete(fat, 363 startcl, start - buffer, 364 endcl, end - buffer, 365 endcl == curcl) == FSFATAL) 366 return FSFATAL; 367 start = buffer; 368 } 369 /* startcl is < CLUST_FIRST for !FAT32 root */ 370 if ((endcl == curcl) || (startcl < CLUST_FIRST)) 371 for (; start < end; start += 32) 372 *start = SLOT_DELETED; 373 return FSDIRMOD; 374 } 375 return FSERROR; 376 } 377 378 /* 379 * Check an in-memory file entry 380 */ 381 static int 382 checksize(struct fat_descriptor *fat, u_char *p, struct dosDirEntry *dir) 383 { 384 int ret = FSOK; 385 size_t chainsize; 386 u_int64_t physicalSize; 387 struct bootblock *boot; 388 389 boot = fat_get_boot(fat); 390 391 /* 392 * Check size on ordinary files 393 */ 394 if (dir->head == CLUST_FREE) { 395 physicalSize = 0; 396 } else { 397 if (!fat_is_valid_cl(fat, dir->head)) 398 return FSERROR; 399 ret = checkchain(fat, dir->head, &chainsize); 400 /* 401 * Upon return, chainsize would hold the chain length 402 * that checkchain() was able to validate, but if the user 403 * refused the proposed repair, it would be unsafe to 404 * proceed with directory entry fix, so bail out in that 405 * case. 406 */ 407 if (ret == FSERROR) { 408 return (FSERROR); 409 } 410 /* 411 * The maximum file size on FAT32 is 4GiB - 1, which 412 * will occupy a cluster chain of exactly 4GiB in 413 * size. On 32-bit platforms, since size_t is 32-bit, 414 * it would wrap back to 0. 415 */ 416 physicalSize = (u_int64_t)chainsize * boot->ClusterSize; 417 } 418 if (physicalSize < dir->size) { 419 pwarn("size of %s is %u, should at most be %ju\n", 420 fullpath(dir), dir->size, (uintmax_t)physicalSize); 421 if (ask(1, "Truncate")) { 422 dir->size = physicalSize; 423 p[28] = (u_char)physicalSize; 424 p[29] = (u_char)(physicalSize >> 8); 425 p[30] = (u_char)(physicalSize >> 16); 426 p[31] = (u_char)(physicalSize >> 24); 427 return FSDIRMOD; 428 } else 429 return FSERROR; 430 } else if (physicalSize - dir->size >= boot->ClusterSize) { 431 pwarn("%s has too many clusters allocated\n", 432 fullpath(dir)); 433 if (ask(1, "Drop superfluous clusters")) { 434 cl_t cl; 435 uint32_t sz, len; 436 437 for (cl = dir->head, len = sz = 0; 438 (sz += boot->ClusterSize) < dir->size; len++) 439 cl = fat_get_cl_next(fat, cl); 440 clearchain(fat, fat_get_cl_next(fat, cl)); 441 ret = fat_set_cl_next(fat, cl, CLUST_EOF); 442 return (FSFATMOD | ret); 443 } else 444 return FSERROR; 445 } 446 return FSOK; 447 } 448 449 static const u_char dot_name[11] = ". "; 450 static const u_char dotdot_name[11] = ".. "; 451 452 /* 453 * Basic sanity check if the subdirectory have good '.' and '..' entries, 454 * and they are directory entries. Further sanity checks are performed 455 * when we traverse into it. 456 */ 457 static int 458 check_subdirectory(struct fat_descriptor *fat, struct dosDirEntry *dir) 459 { 460 u_char *buf, *cp; 461 off_t off; 462 cl_t cl; 463 int retval = FSOK; 464 int fd; 465 struct bootblock *boot; 466 467 boot = fat_get_boot(fat); 468 fd = fat_get_fd(fat); 469 470 cl = dir->head; 471 if (dir->parent && !fat_is_valid_cl(fat, cl)) { 472 return FSERROR; 473 } 474 475 if (!(boot->flags & FAT32) && !dir->parent) { 476 off = boot->bpbResSectors + boot->bpbFATs * 477 boot->FATsecs; 478 } else { 479 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 480 } 481 482 /* 483 * We only need to check the first two entries of the directory, 484 * which is found in the first sector of the directory entry, 485 * so read in only the first sector. 486 */ 487 buf = malloc(boot->bpbBytesPerSec); 488 if (buf == NULL) { 489 perr("No space for directory buffer (%u)", 490 boot->bpbBytesPerSec); 491 return FSFATAL; 492 } 493 494 off *= boot->bpbBytesPerSec; 495 if (lseek(fd, off, SEEK_SET) != off || 496 read(fd, buf, boot->bpbBytesPerSec) != (ssize_t)boot->bpbBytesPerSec) { 497 perr("Unable to read directory"); 498 free(buf); 499 return FSFATAL; 500 } 501 502 /* 503 * Both `.' and `..' must be present and be the first two entries 504 * and be ATTR_DIRECTORY of a valid subdirectory. 505 */ 506 cp = buf; 507 if (memcmp(cp, dot_name, sizeof(dot_name)) != 0 || 508 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 509 pwarn("%s: Incorrect `.' for %s.\n", __func__, dir->name); 510 retval |= FSERROR; 511 } 512 cp += 32; 513 if (memcmp(cp, dotdot_name, sizeof(dotdot_name)) != 0 || 514 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 515 pwarn("%s: Incorrect `..' for %s. \n", __func__, dir->name); 516 retval |= FSERROR; 517 } 518 519 free(buf); 520 return retval; 521 } 522 523 /* 524 * Read a directory and 525 * - resolve long name records 526 * - enter file and directory records into the parent's list 527 * - push directories onto the todo-stack 528 */ 529 static int 530 readDosDirSection(struct fat_descriptor *fat, struct dosDirEntry *dir) 531 { 532 struct bootblock *boot; 533 struct dosDirEntry dirent, *d; 534 u_char *p, *vallfn, *invlfn, *empty; 535 off_t off; 536 int fd, i, j, k, iosize, entries; 537 bool is_legacyroot; 538 cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0; 539 char *t; 540 u_int lidx = 0; 541 int shortSum; 542 int mod = FSOK; 543 size_t dirclusters; 544 #define THISMOD 0x8000 /* Only used within this routine */ 545 546 boot = fat_get_boot(fat); 547 fd = fat_get_fd(fat); 548 549 cl = dir->head; 550 if (dir->parent && (!fat_is_valid_cl(fat, cl))) { 551 /* 552 * Already handled somewhere else. 553 */ 554 return FSOK; 555 } 556 shortSum = -1; 557 vallfn = invlfn = empty = NULL; 558 559 /* 560 * If we are checking the legacy root (for FAT12/FAT16), 561 * we will operate on the whole directory; otherwise, we 562 * will operate on one cluster at a time, and also take 563 * this opportunity to examine the chain. 564 * 565 * Derive how many entries we are going to encounter from 566 * the I/O size. 567 */ 568 is_legacyroot = (dir->parent == NULL && !(boot->flags & FAT32)); 569 if (is_legacyroot) { 570 iosize = boot->bpbRootDirEnts * 32; 571 entries = boot->bpbRootDirEnts; 572 } else { 573 iosize = boot->bpbSecPerClust * boot->bpbBytesPerSec; 574 entries = iosize / 32; 575 mod |= checkchain(fat, dir->head, &dirclusters); 576 } 577 578 do { 579 if (is_legacyroot) { 580 /* 581 * Special case for FAT12/FAT16 root -- read 582 * in the whole root directory. 583 */ 584 off = boot->bpbResSectors + boot->bpbFATs * 585 boot->FATsecs; 586 } else { 587 /* 588 * Otherwise, read in a cluster of the 589 * directory. 590 */ 591 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 592 } 593 594 off *= boot->bpbBytesPerSec; 595 if (lseek(fd, off, SEEK_SET) != off || 596 read(fd, buffer, iosize) != iosize) { 597 perr("Unable to read directory"); 598 return FSFATAL; 599 } 600 601 for (p = buffer, i = 0; i < entries; i++, p += 32) { 602 if (dir->fsckflags & DIREMPWARN) { 603 *p = SLOT_EMPTY; 604 continue; 605 } 606 607 if (*p == SLOT_EMPTY || *p == SLOT_DELETED) { 608 if (*p == SLOT_EMPTY) { 609 dir->fsckflags |= DIREMPTY; 610 empty = p; 611 empcl = cl; 612 } 613 continue; 614 } 615 616 if (dir->fsckflags & DIREMPTY) { 617 if (!(dir->fsckflags & DIREMPWARN)) { 618 pwarn("%s has entries after end of directory\n", 619 fullpath(dir)); 620 if (ask(1, "Extend")) { 621 u_char *q; 622 623 dir->fsckflags &= ~DIREMPTY; 624 if (delete(fat, 625 empcl, empty - buffer, 626 cl, p - buffer, 1) == FSFATAL) 627 return FSFATAL; 628 q = ((empcl == cl) ? empty : buffer); 629 assert(q != NULL); 630 for (; q < p; q += 32) 631 *q = SLOT_DELETED; 632 mod |= THISMOD|FSDIRMOD; 633 } else if (ask(0, "Truncate")) 634 dir->fsckflags |= DIREMPWARN; 635 } 636 if (dir->fsckflags & DIREMPWARN) { 637 *p = SLOT_DELETED; 638 mod |= THISMOD|FSDIRMOD; 639 continue; 640 } else if (dir->fsckflags & DIREMPTY) 641 mod |= FSERROR; 642 empty = NULL; 643 } 644 645 if (p[11] == ATTR_WIN95) { 646 if (*p & LRFIRST) { 647 if (shortSum != -1) { 648 if (!invlfn) { 649 invlfn = vallfn; 650 invcl = valcl; 651 } 652 } 653 memset(longName, 0, sizeof longName); 654 shortSum = p[13]; 655 vallfn = p; 656 valcl = cl; 657 } else if (shortSum != p[13] 658 || lidx != (*p & LRNOMASK)) { 659 if (!invlfn) { 660 invlfn = vallfn; 661 invcl = valcl; 662 } 663 if (!invlfn) { 664 invlfn = p; 665 invcl = cl; 666 } 667 vallfn = NULL; 668 } 669 lidx = *p & LRNOMASK; 670 if (lidx == 0) { 671 pwarn("invalid long name\n"); 672 if (!invlfn) { 673 invlfn = vallfn; 674 invcl = valcl; 675 } 676 vallfn = NULL; 677 continue; 678 } 679 t = longName + --lidx * 13; 680 for (k = 1; k < 11 && t < longName + 681 sizeof(longName); k += 2) { 682 if (!p[k] && !p[k + 1]) 683 break; 684 *t++ = p[k]; 685 /* 686 * Warn about those unusable chars in msdosfs here? XXX 687 */ 688 if (p[k + 1]) 689 t[-1] = '?'; 690 } 691 if (k >= 11) 692 for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) { 693 if (!p[k] && !p[k + 1]) 694 break; 695 *t++ = p[k]; 696 if (p[k + 1]) 697 t[-1] = '?'; 698 } 699 if (k >= 26) 700 for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) { 701 if (!p[k] && !p[k + 1]) 702 break; 703 *t++ = p[k]; 704 if (p[k + 1]) 705 t[-1] = '?'; 706 } 707 if (t >= longName + sizeof(longName)) { 708 pwarn("long filename too long\n"); 709 if (!invlfn) { 710 invlfn = vallfn; 711 invcl = valcl; 712 } 713 vallfn = NULL; 714 } 715 if (p[26] | (p[27] << 8)) { 716 pwarn("long filename record cluster start != 0\n"); 717 if (!invlfn) { 718 invlfn = vallfn; 719 invcl = cl; 720 } 721 vallfn = NULL; 722 } 723 continue; /* long records don't carry further 724 * information */ 725 } 726 727 /* 728 * This is a standard msdosfs directory entry. 729 */ 730 memset(&dirent, 0, sizeof dirent); 731 732 /* 733 * it's a short name record, but we need to know 734 * more, so get the flags first. 735 */ 736 dirent.flags = p[11]; 737 738 /* 739 * Translate from 850 to ISO here XXX 740 */ 741 for (j = 0; j < 8; j++) 742 dirent.name[j] = p[j]; 743 dirent.name[8] = '\0'; 744 for (k = 7; k >= 0 && dirent.name[k] == ' '; k--) 745 dirent.name[k] = '\0'; 746 if (k < 0 || dirent.name[k] != '\0') 747 k++; 748 if (dirent.name[0] == SLOT_E5) 749 dirent.name[0] = 0xe5; 750 751 if (dirent.flags & ATTR_VOLUME) { 752 if (vallfn || invlfn) { 753 mod |= removede(fat, 754 invlfn ? invlfn : vallfn, p, 755 invlfn ? invcl : valcl, -1, 0, 756 fullpath(dir), 2); 757 vallfn = NULL; 758 invlfn = NULL; 759 } 760 continue; 761 } 762 763 if (p[8] != ' ') 764 dirent.name[k++] = '.'; 765 for (j = 0; j < 3; j++) 766 dirent.name[k++] = p[j+8]; 767 dirent.name[k] = '\0'; 768 for (k--; k >= 0 && dirent.name[k] == ' '; k--) 769 dirent.name[k] = '\0'; 770 771 if (vallfn && shortSum != calcShortSum(p)) { 772 if (!invlfn) { 773 invlfn = vallfn; 774 invcl = valcl; 775 } 776 vallfn = NULL; 777 } 778 dirent.head = p[26] | (p[27] << 8); 779 if (boot->ClustMask == CLUST32_MASK) 780 dirent.head |= (p[20] << 16) | (p[21] << 24); 781 dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24); 782 if (vallfn) { 783 strlcpy(dirent.lname, longName, 784 sizeof(dirent.lname)); 785 longName[0] = '\0'; 786 shortSum = -1; 787 } 788 789 dirent.parent = dir; 790 dirent.next = dir->child; 791 792 if (invlfn) { 793 mod |= k = removede(fat, 794 invlfn, vallfn ? vallfn : p, 795 invcl, vallfn ? valcl : cl, cl, 796 fullpath(&dirent), 0); 797 if (mod & FSFATAL) 798 return FSFATAL; 799 if (vallfn 800 ? (valcl == cl && vallfn != buffer) 801 : p != buffer) 802 if (k & FSDIRMOD) 803 mod |= THISMOD; 804 } 805 806 vallfn = NULL; /* not used any longer */ 807 invlfn = NULL; 808 809 /* 810 * Check if the directory entry is sane. 811 * 812 * '.' and '..' are skipped, their sanity is 813 * checked somewhere else. 814 * 815 * For everything else, check if we have a new, 816 * valid cluster chain (beginning of a file or 817 * directory that was never previously claimed 818 * by another file) when it's a non-empty file 819 * or a directory. The sanity of the cluster 820 * chain is checked at a later time when we 821 * traverse into the directory, or examine the 822 * file's directory entry. 823 * 824 * The only possible fix is to delete the entry 825 * if it's a directory; for file, we have to 826 * truncate the size to 0. 827 */ 828 if (!(dirent.flags & ATTR_DIRECTORY) || 829 (strcmp(dirent.name, ".") != 0 && 830 strcmp(dirent.name, "..") != 0)) { 831 if ((dirent.size != 0 || (dirent.flags & ATTR_DIRECTORY)) && 832 ((!fat_is_valid_cl(fat, dirent.head) || 833 !fat_is_cl_head(fat, dirent.head)))) { 834 if (!fat_is_valid_cl(fat, dirent.head)) { 835 pwarn("%s starts with cluster out of range(%u)\n", 836 fullpath(&dirent), 837 dirent.head); 838 } else { 839 pwarn("%s doesn't start a new cluster chain\n", 840 fullpath(&dirent)); 841 } 842 843 if (dirent.flags & ATTR_DIRECTORY) { 844 if (ask(0, "Remove")) { 845 *p = SLOT_DELETED; 846 mod |= THISMOD|FSDIRMOD; 847 } else 848 mod |= FSERROR; 849 continue; 850 } else { 851 if (ask(1, "Truncate")) { 852 p[28] = p[29] = p[30] = p[31] = 0; 853 p[26] = p[27] = 0; 854 if (boot->ClustMask == CLUST32_MASK) 855 p[20] = p[21] = 0; 856 dirent.size = 0; 857 dirent.head = 0; 858 mod |= THISMOD|FSDIRMOD; 859 } else 860 mod |= FSERROR; 861 } 862 } 863 } 864 if (dirent.flags & ATTR_DIRECTORY) { 865 /* 866 * gather more info for directories 867 */ 868 struct dirTodoNode *n; 869 870 if (dirent.size) { 871 pwarn("Directory %s has size != 0\n", 872 fullpath(&dirent)); 873 if (ask(1, "Correct")) { 874 p[28] = p[29] = p[30] = p[31] = 0; 875 dirent.size = 0; 876 mod |= THISMOD|FSDIRMOD; 877 } else 878 mod |= FSERROR; 879 } 880 /* 881 * handle `.' and `..' specially 882 */ 883 if (strcmp(dirent.name, ".") == 0) { 884 if (dirent.head != dir->head) { 885 pwarn("`.' entry in %s has incorrect start cluster\n", 886 fullpath(dir)); 887 if (ask(1, "Correct")) { 888 dirent.head = dir->head; 889 p[26] = (u_char)dirent.head; 890 p[27] = (u_char)(dirent.head >> 8); 891 if (boot->ClustMask == CLUST32_MASK) { 892 p[20] = (u_char)(dirent.head >> 16); 893 p[21] = (u_char)(dirent.head >> 24); 894 } 895 mod |= THISMOD|FSDIRMOD; 896 } else 897 mod |= FSERROR; 898 } 899 continue; 900 } else if (strcmp(dirent.name, "..") == 0) { 901 if (dir->parent) { /* XXX */ 902 if (!dir->parent->parent) { 903 if (dirent.head) { 904 pwarn("`..' entry in %s has non-zero start cluster\n", 905 fullpath(dir)); 906 if (ask(1, "Correct")) { 907 dirent.head = 0; 908 p[26] = p[27] = 0; 909 if (boot->ClustMask == CLUST32_MASK) 910 p[20] = p[21] = 0; 911 mod |= THISMOD|FSDIRMOD; 912 } else 913 mod |= FSERROR; 914 } 915 } else if (dirent.head != dir->parent->head) { 916 pwarn("`..' entry in %s has incorrect start cluster\n", 917 fullpath(dir)); 918 if (ask(1, "Correct")) { 919 dirent.head = dir->parent->head; 920 p[26] = (u_char)dirent.head; 921 p[27] = (u_char)(dirent.head >> 8); 922 if (boot->ClustMask == CLUST32_MASK) { 923 p[20] = (u_char)(dirent.head >> 16); 924 p[21] = (u_char)(dirent.head >> 24); 925 } 926 mod |= THISMOD|FSDIRMOD; 927 } else 928 mod |= FSERROR; 929 } 930 } 931 continue; 932 } else { 933 /* 934 * Only one directory entry can point 935 * to dir->head, it's '.'. 936 */ 937 if (dirent.head == dir->head) { 938 pwarn("%s entry in %s has incorrect start cluster\n", 939 dirent.name, fullpath(dir)); 940 if (ask(1, "Remove")) { 941 *p = SLOT_DELETED; 942 mod |= THISMOD|FSDIRMOD; 943 } else 944 mod |= FSERROR; 945 continue; 946 } else if ((check_subdirectory(fat, 947 &dirent) & FSERROR) == FSERROR) { 948 /* 949 * A subdirectory should have 950 * a dot (.) entry and a dot-dot 951 * (..) entry of ATTR_DIRECTORY, 952 * we will inspect further when 953 * traversing into it. 954 */ 955 if (ask(1, "Remove")) { 956 *p = SLOT_DELETED; 957 mod |= THISMOD|FSDIRMOD; 958 } else 959 mod |= FSERROR; 960 continue; 961 } 962 } 963 964 /* create directory tree node */ 965 if (!(d = newDosDirEntry())) { 966 perr("No space for directory"); 967 return FSFATAL; 968 } 969 memcpy(d, &dirent, sizeof(struct dosDirEntry)); 970 /* link it into the tree */ 971 dir->child = d; 972 973 /* Enter this directory into the todo list */ 974 if (!(n = newDirTodo())) { 975 perr("No space for todo list"); 976 return FSFATAL; 977 } 978 n->next = pendingDirectories; 979 n->dir = d; 980 pendingDirectories = n; 981 } else { 982 mod |= k = checksize(fat, p, &dirent); 983 if (k & FSDIRMOD) 984 mod |= THISMOD; 985 } 986 boot->NumFiles++; 987 } 988 989 if (is_legacyroot) { 990 /* 991 * Don't bother to write back right now because 992 * we may continue to make modification to the 993 * non-FAT32 root directory below. 994 */ 995 break; 996 } else if (mod & THISMOD) { 997 if (lseek(fd, off, SEEK_SET) != off 998 || write(fd, buffer, iosize) != iosize) { 999 perr("Unable to write directory"); 1000 return FSFATAL; 1001 } 1002 mod &= ~THISMOD; 1003 } 1004 } while (fat_is_valid_cl(fat, (cl = fat_get_cl_next(fat, cl)))); 1005 if (invlfn || vallfn) 1006 mod |= removede(fat, 1007 invlfn ? invlfn : vallfn, p, 1008 invlfn ? invcl : valcl, -1, 0, 1009 fullpath(dir), 1); 1010 1011 /* 1012 * The root directory of non-FAT32 filesystems is in a special 1013 * area and may have been modified above removede() without 1014 * being written out. 1015 */ 1016 if ((mod & FSDIRMOD) && is_legacyroot) { 1017 if (lseek(fd, off, SEEK_SET) != off 1018 || write(fd, buffer, iosize) != iosize) { 1019 perr("Unable to write directory"); 1020 return FSFATAL; 1021 } 1022 mod &= ~THISMOD; 1023 } 1024 return mod & ~THISMOD; 1025 } 1026 1027 int 1028 handleDirTree(struct fat_descriptor *fat) 1029 { 1030 int mod; 1031 1032 mod = readDosDirSection(fat, rootDir); 1033 if (mod & FSFATAL) 1034 return FSFATAL; 1035 1036 /* 1037 * process the directory todo list 1038 */ 1039 while (pendingDirectories) { 1040 struct dosDirEntry *dir = pendingDirectories->dir; 1041 struct dirTodoNode *n = pendingDirectories->next; 1042 1043 /* 1044 * remove TODO entry now, the list might change during 1045 * directory reads 1046 */ 1047 freeDirTodo(pendingDirectories); 1048 pendingDirectories = n; 1049 1050 /* 1051 * handle subdirectory 1052 */ 1053 mod |= readDosDirSection(fat, dir); 1054 if (mod & FSFATAL) 1055 return FSFATAL; 1056 } 1057 1058 return mod; 1059 } 1060 1061 /* 1062 * Try to reconnect a FAT chain into dir 1063 */ 1064 static u_char *lfbuf; 1065 static cl_t lfcl; 1066 static off_t lfoff; 1067 1068 int 1069 reconnect(struct fat_descriptor *fat, cl_t head, size_t length) 1070 { 1071 struct bootblock *boot = fat_get_boot(fat); 1072 struct dosDirEntry d; 1073 int len, dosfs; 1074 u_char *p; 1075 1076 dosfs = fat_get_fd(fat); 1077 1078 if (!ask(1, "Reconnect")) 1079 return FSERROR; 1080 1081 if (!lostDir) { 1082 for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) { 1083 if (!strcmp(lostDir->name, LOSTDIR)) 1084 break; 1085 } 1086 if (!lostDir) { /* Create LOSTDIR? XXX */ 1087 pwarn("No %s directory\n", LOSTDIR); 1088 return FSERROR; 1089 } 1090 } 1091 if (!lfbuf) { 1092 lfbuf = malloc(boot->ClusterSize); 1093 if (!lfbuf) { 1094 perr("No space for buffer"); 1095 return FSFATAL; 1096 } 1097 p = NULL; 1098 } else 1099 p = lfbuf; 1100 while (1) { 1101 if (p) 1102 for (; p < lfbuf + boot->ClusterSize; p += 32) 1103 if (*p == SLOT_EMPTY 1104 || *p == SLOT_DELETED) 1105 break; 1106 if (p && p < lfbuf + boot->ClusterSize) 1107 break; 1108 lfcl = p ? fat_get_cl_next(fat, lfcl) : lostDir->head; 1109 if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) { 1110 /* Extend LOSTDIR? XXX */ 1111 pwarn("No space in %s\n", LOSTDIR); 1112 lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0; 1113 return FSERROR; 1114 } 1115 lfoff = (lfcl - CLUST_FIRST) * boot->ClusterSize 1116 + boot->FirstCluster * boot->bpbBytesPerSec; 1117 1118 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1119 || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1120 perr("could not read LOST.DIR"); 1121 return FSFATAL; 1122 } 1123 p = lfbuf; 1124 } 1125 1126 boot->NumFiles++; 1127 /* Ensure uniqueness of entry here! XXX */ 1128 memset(&d, 0, sizeof d); 1129 /* worst case -1 = 4294967295, 10 digits */ 1130 len = snprintf(d.name, sizeof(d.name), "%u", head); 1131 d.flags = 0; 1132 d.head = head; 1133 d.size = length * boot->ClusterSize; 1134 1135 memcpy(p, d.name, len); 1136 memset(p + len, ' ', 11 - len); 1137 memset(p + 11, 0, 32 - 11); 1138 p[26] = (u_char)d.head; 1139 p[27] = (u_char)(d.head >> 8); 1140 if (boot->ClustMask == CLUST32_MASK) { 1141 p[20] = (u_char)(d.head >> 16); 1142 p[21] = (u_char)(d.head >> 24); 1143 } 1144 p[28] = (u_char)d.size; 1145 p[29] = (u_char)(d.size >> 8); 1146 p[30] = (u_char)(d.size >> 16); 1147 p[31] = (u_char)(d.size >> 24); 1148 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1149 || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1150 perr("could not write LOST.DIR"); 1151 return FSFATAL; 1152 } 1153 return FSDIRMOD; 1154 } 1155 1156 void 1157 finishlf(void) 1158 { 1159 if (lfbuf) 1160 free(lfbuf); 1161 lfbuf = NULL; 1162 } 1163