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 physicalSize; 386 struct bootblock *boot; 387 388 boot = fat_get_boot(fat); 389 390 /* 391 * Check size on ordinary files 392 */ 393 if (dir->head == CLUST_FREE) { 394 physicalSize = 0; 395 } else { 396 if (!fat_is_valid_cl(fat, dir->head)) 397 return FSERROR; 398 ret = checkchain(fat, dir->head, &physicalSize); 399 /* 400 * Upon return, physicalSize would hold the chain length 401 * that checkchain() was able to validate, but if the user 402 * refused the proposed repair, it would be unsafe to 403 * proceed with directory entry fix, so bail out in that 404 * case. 405 */ 406 if (ret == FSERROR) { 407 return (FSERROR); 408 } 409 physicalSize *= boot->ClusterSize; 410 } 411 if (physicalSize < dir->size) { 412 pwarn("size of %s is %u, should at most be %zu\n", 413 fullpath(dir), dir->size, physicalSize); 414 if (ask(1, "Truncate")) { 415 dir->size = physicalSize; 416 p[28] = (u_char)physicalSize; 417 p[29] = (u_char)(physicalSize >> 8); 418 p[30] = (u_char)(physicalSize >> 16); 419 p[31] = (u_char)(physicalSize >> 24); 420 return FSDIRMOD; 421 } else 422 return FSERROR; 423 } else if (physicalSize - dir->size >= boot->ClusterSize) { 424 pwarn("%s has too many clusters allocated\n", 425 fullpath(dir)); 426 if (ask(1, "Drop superfluous clusters")) { 427 cl_t cl; 428 uint32_t sz, len; 429 430 for (cl = dir->head, len = sz = 0; 431 (sz += boot->ClusterSize) < dir->size; len++) 432 cl = fat_get_cl_next(fat, cl); 433 clearchain(fat, fat_get_cl_next(fat, cl)); 434 ret = fat_set_cl_next(fat, cl, CLUST_EOF); 435 return (FSFATMOD | ret); 436 } else 437 return FSERROR; 438 } 439 return FSOK; 440 } 441 442 static const u_char dot_name[11] = ". "; 443 static const u_char dotdot_name[11] = ".. "; 444 445 /* 446 * Basic sanity check if the subdirectory have good '.' and '..' entries, 447 * and they are directory entries. Further sanity checks are performed 448 * when we traverse into it. 449 */ 450 static int 451 check_subdirectory(struct fat_descriptor *fat, struct dosDirEntry *dir) 452 { 453 u_char *buf, *cp; 454 off_t off; 455 cl_t cl; 456 int retval = FSOK; 457 int fd; 458 struct bootblock *boot; 459 460 boot = fat_get_boot(fat); 461 fd = fat_get_fd(fat); 462 463 cl = dir->head; 464 if (dir->parent && !fat_is_valid_cl(fat, cl)) { 465 return FSERROR; 466 } 467 468 if (!(boot->flags & FAT32) && !dir->parent) { 469 off = boot->bpbResSectors + boot->bpbFATs * 470 boot->FATsecs; 471 } else { 472 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 473 } 474 475 /* 476 * We only need to check the first two entries of the directory, 477 * which is found in the first sector of the directory entry, 478 * so read in only the first sector. 479 */ 480 buf = malloc(boot->bpbBytesPerSec); 481 if (buf == NULL) { 482 perr("No space for directory buffer (%u)", 483 boot->bpbBytesPerSec); 484 return FSFATAL; 485 } 486 487 off *= boot->bpbBytesPerSec; 488 if (lseek(fd, off, SEEK_SET) != off || 489 read(fd, buf, boot->bpbBytesPerSec) != (ssize_t)boot->bpbBytesPerSec) { 490 perr("Unable to read directory"); 491 free(buf); 492 return FSFATAL; 493 } 494 495 /* 496 * Both `.' and `..' must be present and be the first two entries 497 * and be ATTR_DIRECTORY of a valid subdirectory. 498 */ 499 cp = buf; 500 if (memcmp(cp, dot_name, sizeof(dot_name)) != 0 || 501 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 502 pwarn("%s: Incorrect `.' for %s.\n", __func__, dir->name); 503 retval |= FSERROR; 504 } 505 cp += 32; 506 if (memcmp(cp, dotdot_name, sizeof(dotdot_name)) != 0 || 507 (cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) { 508 pwarn("%s: Incorrect `..' for %s. \n", __func__, dir->name); 509 retval |= FSERROR; 510 } 511 512 free(buf); 513 return retval; 514 } 515 516 /* 517 * Read a directory and 518 * - resolve long name records 519 * - enter file and directory records into the parent's list 520 * - push directories onto the todo-stack 521 */ 522 static int 523 readDosDirSection(struct fat_descriptor *fat, struct dosDirEntry *dir) 524 { 525 struct bootblock *boot; 526 struct dosDirEntry dirent, *d; 527 u_char *p, *vallfn, *invlfn, *empty; 528 off_t off; 529 int fd, i, j, k, iosize, entries; 530 bool is_legacyroot; 531 cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0; 532 char *t; 533 u_int lidx = 0; 534 int shortSum; 535 int mod = FSOK; 536 size_t dirclusters; 537 #define THISMOD 0x8000 /* Only used within this routine */ 538 539 boot = fat_get_boot(fat); 540 fd = fat_get_fd(fat); 541 542 cl = dir->head; 543 if (dir->parent && (!fat_is_valid_cl(fat, cl))) { 544 /* 545 * Already handled somewhere else. 546 */ 547 return FSOK; 548 } 549 shortSum = -1; 550 vallfn = invlfn = empty = NULL; 551 552 /* 553 * If we are checking the legacy root (for FAT12/FAT16), 554 * we will operate on the whole directory; otherwise, we 555 * will operate on one cluster at a time, and also take 556 * this opportunity to examine the chain. 557 * 558 * Derive how many entries we are going to encounter from 559 * the I/O size. 560 */ 561 is_legacyroot = (dir->parent == NULL && !(boot->flags & FAT32)); 562 if (is_legacyroot) { 563 iosize = boot->bpbRootDirEnts * 32; 564 entries = boot->bpbRootDirEnts; 565 } else { 566 iosize = boot->bpbSecPerClust * boot->bpbBytesPerSec; 567 entries = iosize / 32; 568 mod |= checkchain(fat, dir->head, &dirclusters); 569 } 570 571 do { 572 if (is_legacyroot) { 573 /* 574 * Special case for FAT12/FAT16 root -- read 575 * in the whole root directory. 576 */ 577 off = boot->bpbResSectors + boot->bpbFATs * 578 boot->FATsecs; 579 } else { 580 /* 581 * Otherwise, read in a cluster of the 582 * directory. 583 */ 584 off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster; 585 } 586 587 off *= boot->bpbBytesPerSec; 588 if (lseek(fd, off, SEEK_SET) != off || 589 read(fd, buffer, iosize) != iosize) { 590 perr("Unable to read directory"); 591 return FSFATAL; 592 } 593 594 for (p = buffer, i = 0; i < entries; i++, p += 32) { 595 if (dir->fsckflags & DIREMPWARN) { 596 *p = SLOT_EMPTY; 597 continue; 598 } 599 600 if (*p == SLOT_EMPTY || *p == SLOT_DELETED) { 601 if (*p == SLOT_EMPTY) { 602 dir->fsckflags |= DIREMPTY; 603 empty = p; 604 empcl = cl; 605 } 606 continue; 607 } 608 609 if (dir->fsckflags & DIREMPTY) { 610 if (!(dir->fsckflags & DIREMPWARN)) { 611 pwarn("%s has entries after end of directory\n", 612 fullpath(dir)); 613 if (ask(1, "Extend")) { 614 u_char *q; 615 616 dir->fsckflags &= ~DIREMPTY; 617 if (delete(fat, 618 empcl, empty - buffer, 619 cl, p - buffer, 1) == FSFATAL) 620 return FSFATAL; 621 q = ((empcl == cl) ? empty : buffer); 622 assert(q != NULL); 623 for (; q < p; q += 32) 624 *q = SLOT_DELETED; 625 mod |= THISMOD|FSDIRMOD; 626 } else if (ask(0, "Truncate")) 627 dir->fsckflags |= DIREMPWARN; 628 } 629 if (dir->fsckflags & DIREMPWARN) { 630 *p = SLOT_DELETED; 631 mod |= THISMOD|FSDIRMOD; 632 continue; 633 } else if (dir->fsckflags & DIREMPTY) 634 mod |= FSERROR; 635 empty = NULL; 636 } 637 638 if (p[11] == ATTR_WIN95) { 639 if (*p & LRFIRST) { 640 if (shortSum != -1) { 641 if (!invlfn) { 642 invlfn = vallfn; 643 invcl = valcl; 644 } 645 } 646 memset(longName, 0, sizeof longName); 647 shortSum = p[13]; 648 vallfn = p; 649 valcl = cl; 650 } else if (shortSum != p[13] 651 || lidx != (*p & LRNOMASK)) { 652 if (!invlfn) { 653 invlfn = vallfn; 654 invcl = valcl; 655 } 656 if (!invlfn) { 657 invlfn = p; 658 invcl = cl; 659 } 660 vallfn = NULL; 661 } 662 lidx = *p & LRNOMASK; 663 if (lidx == 0) { 664 pwarn("invalid long name\n"); 665 if (!invlfn) { 666 invlfn = vallfn; 667 invcl = valcl; 668 } 669 vallfn = NULL; 670 continue; 671 } 672 t = longName + --lidx * 13; 673 for (k = 1; k < 11 && t < longName + 674 sizeof(longName); k += 2) { 675 if (!p[k] && !p[k + 1]) 676 break; 677 *t++ = p[k]; 678 /* 679 * Warn about those unusable chars in msdosfs here? XXX 680 */ 681 if (p[k + 1]) 682 t[-1] = '?'; 683 } 684 if (k >= 11) 685 for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) { 686 if (!p[k] && !p[k + 1]) 687 break; 688 *t++ = p[k]; 689 if (p[k + 1]) 690 t[-1] = '?'; 691 } 692 if (k >= 26) 693 for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) { 694 if (!p[k] && !p[k + 1]) 695 break; 696 *t++ = p[k]; 697 if (p[k + 1]) 698 t[-1] = '?'; 699 } 700 if (t >= longName + sizeof(longName)) { 701 pwarn("long filename too long\n"); 702 if (!invlfn) { 703 invlfn = vallfn; 704 invcl = valcl; 705 } 706 vallfn = NULL; 707 } 708 if (p[26] | (p[27] << 8)) { 709 pwarn("long filename record cluster start != 0\n"); 710 if (!invlfn) { 711 invlfn = vallfn; 712 invcl = cl; 713 } 714 vallfn = NULL; 715 } 716 continue; /* long records don't carry further 717 * information */ 718 } 719 720 /* 721 * This is a standard msdosfs directory entry. 722 */ 723 memset(&dirent, 0, sizeof dirent); 724 725 /* 726 * it's a short name record, but we need to know 727 * more, so get the flags first. 728 */ 729 dirent.flags = p[11]; 730 731 /* 732 * Translate from 850 to ISO here XXX 733 */ 734 for (j = 0; j < 8; j++) 735 dirent.name[j] = p[j]; 736 dirent.name[8] = '\0'; 737 for (k = 7; k >= 0 && dirent.name[k] == ' '; k--) 738 dirent.name[k] = '\0'; 739 if (k < 0 || dirent.name[k] != '\0') 740 k++; 741 if (dirent.name[0] == SLOT_E5) 742 dirent.name[0] = 0xe5; 743 744 if (dirent.flags & ATTR_VOLUME) { 745 if (vallfn || invlfn) { 746 mod |= removede(fat, 747 invlfn ? invlfn : vallfn, p, 748 invlfn ? invcl : valcl, -1, 0, 749 fullpath(dir), 2); 750 vallfn = NULL; 751 invlfn = NULL; 752 } 753 continue; 754 } 755 756 if (p[8] != ' ') 757 dirent.name[k++] = '.'; 758 for (j = 0; j < 3; j++) 759 dirent.name[k++] = p[j+8]; 760 dirent.name[k] = '\0'; 761 for (k--; k >= 0 && dirent.name[k] == ' '; k--) 762 dirent.name[k] = '\0'; 763 764 if (vallfn && shortSum != calcShortSum(p)) { 765 if (!invlfn) { 766 invlfn = vallfn; 767 invcl = valcl; 768 } 769 vallfn = NULL; 770 } 771 dirent.head = p[26] | (p[27] << 8); 772 if (boot->ClustMask == CLUST32_MASK) 773 dirent.head |= (p[20] << 16) | (p[21] << 24); 774 dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24); 775 if (vallfn) { 776 strlcpy(dirent.lname, longName, 777 sizeof(dirent.lname)); 778 longName[0] = '\0'; 779 shortSum = -1; 780 } 781 782 dirent.parent = dir; 783 dirent.next = dir->child; 784 785 if (invlfn) { 786 mod |= k = removede(fat, 787 invlfn, vallfn ? vallfn : p, 788 invcl, vallfn ? valcl : cl, cl, 789 fullpath(&dirent), 0); 790 if (mod & FSFATAL) 791 return FSFATAL; 792 if (vallfn 793 ? (valcl == cl && vallfn != buffer) 794 : p != buffer) 795 if (k & FSDIRMOD) 796 mod |= THISMOD; 797 } 798 799 vallfn = NULL; /* not used any longer */ 800 invlfn = NULL; 801 802 /* 803 * Check if the directory entry is sane. 804 * 805 * '.' and '..' are skipped, their sanity is 806 * checked somewhere else. 807 * 808 * For everything else, check if we have a new, 809 * valid cluster chain (beginning of a file or 810 * directory that was never previously claimed 811 * by another file) when it's a non-empty file 812 * or a directory. The sanity of the cluster 813 * chain is checked at a later time when we 814 * traverse into the directory, or examine the 815 * file's directory entry. 816 * 817 * The only possible fix is to delete the entry 818 * if it's a directory; for file, we have to 819 * truncate the size to 0. 820 */ 821 if (!(dirent.flags & ATTR_DIRECTORY) || 822 (strcmp(dirent.name, ".") != 0 && 823 strcmp(dirent.name, "..") != 0)) { 824 if ((dirent.size != 0 || (dirent.flags & ATTR_DIRECTORY)) && 825 ((!fat_is_valid_cl(fat, dirent.head) || 826 !fat_is_cl_head(fat, dirent.head)))) { 827 if (!fat_is_valid_cl(fat, dirent.head)) { 828 pwarn("%s starts with cluster out of range(%u)\n", 829 fullpath(&dirent), 830 dirent.head); 831 } else { 832 pwarn("%s doesn't start a new cluster chain\n", 833 fullpath(&dirent)); 834 } 835 836 if (dirent.flags & ATTR_DIRECTORY) { 837 if (ask(0, "Remove")) { 838 *p = SLOT_DELETED; 839 mod |= THISMOD|FSDIRMOD; 840 } else 841 mod |= FSERROR; 842 continue; 843 } else { 844 if (ask(1, "Truncate")) { 845 p[28] = p[29] = p[30] = p[31] = 0; 846 p[26] = p[27] = 0; 847 if (boot->ClustMask == CLUST32_MASK) 848 p[20] = p[21] = 0; 849 dirent.size = 0; 850 dirent.head = 0; 851 mod |= THISMOD|FSDIRMOD; 852 } else 853 mod |= FSERROR; 854 } 855 } 856 } 857 if (dirent.flags & ATTR_DIRECTORY) { 858 /* 859 * gather more info for directories 860 */ 861 struct dirTodoNode *n; 862 863 if (dirent.size) { 864 pwarn("Directory %s has size != 0\n", 865 fullpath(&dirent)); 866 if (ask(1, "Correct")) { 867 p[28] = p[29] = p[30] = p[31] = 0; 868 dirent.size = 0; 869 mod |= THISMOD|FSDIRMOD; 870 } else 871 mod |= FSERROR; 872 } 873 /* 874 * handle `.' and `..' specially 875 */ 876 if (strcmp(dirent.name, ".") == 0) { 877 if (dirent.head != dir->head) { 878 pwarn("`.' entry in %s has incorrect start cluster\n", 879 fullpath(dir)); 880 if (ask(1, "Correct")) { 881 dirent.head = dir->head; 882 p[26] = (u_char)dirent.head; 883 p[27] = (u_char)(dirent.head >> 8); 884 if (boot->ClustMask == CLUST32_MASK) { 885 p[20] = (u_char)(dirent.head >> 16); 886 p[21] = (u_char)(dirent.head >> 24); 887 } 888 mod |= THISMOD|FSDIRMOD; 889 } else 890 mod |= FSERROR; 891 } 892 continue; 893 } else if (strcmp(dirent.name, "..") == 0) { 894 if (dir->parent) { /* XXX */ 895 if (!dir->parent->parent) { 896 if (dirent.head) { 897 pwarn("`..' entry in %s has non-zero start cluster\n", 898 fullpath(dir)); 899 if (ask(1, "Correct")) { 900 dirent.head = 0; 901 p[26] = p[27] = 0; 902 if (boot->ClustMask == CLUST32_MASK) 903 p[20] = p[21] = 0; 904 mod |= THISMOD|FSDIRMOD; 905 } else 906 mod |= FSERROR; 907 } 908 } else if (dirent.head != dir->parent->head) { 909 pwarn("`..' entry in %s has incorrect start cluster\n", 910 fullpath(dir)); 911 if (ask(1, "Correct")) { 912 dirent.head = dir->parent->head; 913 p[26] = (u_char)dirent.head; 914 p[27] = (u_char)(dirent.head >> 8); 915 if (boot->ClustMask == CLUST32_MASK) { 916 p[20] = (u_char)(dirent.head >> 16); 917 p[21] = (u_char)(dirent.head >> 24); 918 } 919 mod |= THISMOD|FSDIRMOD; 920 } else 921 mod |= FSERROR; 922 } 923 } 924 continue; 925 } else { 926 /* 927 * Only one directory entry can point 928 * to dir->head, it's '.'. 929 */ 930 if (dirent.head == dir->head) { 931 pwarn("%s entry in %s has incorrect start cluster\n", 932 dirent.name, fullpath(dir)); 933 if (ask(1, "Remove")) { 934 *p = SLOT_DELETED; 935 mod |= THISMOD|FSDIRMOD; 936 } else 937 mod |= FSERROR; 938 continue; 939 } else if ((check_subdirectory(fat, 940 &dirent) & FSERROR) == FSERROR) { 941 /* 942 * A subdirectory should have 943 * a dot (.) entry and a dot-dot 944 * (..) entry of ATTR_DIRECTORY, 945 * we will inspect further when 946 * traversing into it. 947 */ 948 if (ask(1, "Remove")) { 949 *p = SLOT_DELETED; 950 mod |= THISMOD|FSDIRMOD; 951 } else 952 mod |= FSERROR; 953 continue; 954 } 955 } 956 957 /* create directory tree node */ 958 if (!(d = newDosDirEntry())) { 959 perr("No space for directory"); 960 return FSFATAL; 961 } 962 memcpy(d, &dirent, sizeof(struct dosDirEntry)); 963 /* link it into the tree */ 964 dir->child = d; 965 966 /* Enter this directory into the todo list */ 967 if (!(n = newDirTodo())) { 968 perr("No space for todo list"); 969 return FSFATAL; 970 } 971 n->next = pendingDirectories; 972 n->dir = d; 973 pendingDirectories = n; 974 } else { 975 mod |= k = checksize(fat, p, &dirent); 976 if (k & FSDIRMOD) 977 mod |= THISMOD; 978 } 979 boot->NumFiles++; 980 } 981 982 if (is_legacyroot) { 983 /* 984 * Don't bother to write back right now because 985 * we may continue to make modification to the 986 * non-FAT32 root directory below. 987 */ 988 break; 989 } else if (mod & THISMOD) { 990 if (lseek(fd, off, SEEK_SET) != off 991 || write(fd, buffer, iosize) != iosize) { 992 perr("Unable to write directory"); 993 return FSFATAL; 994 } 995 mod &= ~THISMOD; 996 } 997 } while (fat_is_valid_cl(fat, (cl = fat_get_cl_next(fat, cl)))); 998 if (invlfn || vallfn) 999 mod |= removede(fat, 1000 invlfn ? invlfn : vallfn, p, 1001 invlfn ? invcl : valcl, -1, 0, 1002 fullpath(dir), 1); 1003 1004 /* 1005 * The root directory of non-FAT32 filesystems is in a special 1006 * area and may have been modified above removede() without 1007 * being written out. 1008 */ 1009 if ((mod & FSDIRMOD) && is_legacyroot) { 1010 if (lseek(fd, off, SEEK_SET) != off 1011 || write(fd, buffer, iosize) != iosize) { 1012 perr("Unable to write directory"); 1013 return FSFATAL; 1014 } 1015 mod &= ~THISMOD; 1016 } 1017 return mod & ~THISMOD; 1018 } 1019 1020 int 1021 handleDirTree(struct fat_descriptor *fat) 1022 { 1023 int mod; 1024 1025 mod = readDosDirSection(fat, rootDir); 1026 if (mod & FSFATAL) 1027 return FSFATAL; 1028 1029 /* 1030 * process the directory todo list 1031 */ 1032 while (pendingDirectories) { 1033 struct dosDirEntry *dir = pendingDirectories->dir; 1034 struct dirTodoNode *n = pendingDirectories->next; 1035 1036 /* 1037 * remove TODO entry now, the list might change during 1038 * directory reads 1039 */ 1040 freeDirTodo(pendingDirectories); 1041 pendingDirectories = n; 1042 1043 /* 1044 * handle subdirectory 1045 */ 1046 mod |= readDosDirSection(fat, dir); 1047 if (mod & FSFATAL) 1048 return FSFATAL; 1049 } 1050 1051 return mod; 1052 } 1053 1054 /* 1055 * Try to reconnect a FAT chain into dir 1056 */ 1057 static u_char *lfbuf; 1058 static cl_t lfcl; 1059 static off_t lfoff; 1060 1061 int 1062 reconnect(struct fat_descriptor *fat, cl_t head, size_t length) 1063 { 1064 struct bootblock *boot = fat_get_boot(fat); 1065 struct dosDirEntry d; 1066 int len, dosfs; 1067 u_char *p; 1068 1069 dosfs = fat_get_fd(fat); 1070 1071 if (!ask(1, "Reconnect")) 1072 return FSERROR; 1073 1074 if (!lostDir) { 1075 for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) { 1076 if (!strcmp(lostDir->name, LOSTDIR)) 1077 break; 1078 } 1079 if (!lostDir) { /* Create LOSTDIR? XXX */ 1080 pwarn("No %s directory\n", LOSTDIR); 1081 return FSERROR; 1082 } 1083 } 1084 if (!lfbuf) { 1085 lfbuf = malloc(boot->ClusterSize); 1086 if (!lfbuf) { 1087 perr("No space for buffer"); 1088 return FSFATAL; 1089 } 1090 p = NULL; 1091 } else 1092 p = lfbuf; 1093 while (1) { 1094 if (p) 1095 for (; p < lfbuf + boot->ClusterSize; p += 32) 1096 if (*p == SLOT_EMPTY 1097 || *p == SLOT_DELETED) 1098 break; 1099 if (p && p < lfbuf + boot->ClusterSize) 1100 break; 1101 lfcl = p ? fat_get_cl_next(fat, lfcl) : lostDir->head; 1102 if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) { 1103 /* Extend LOSTDIR? XXX */ 1104 pwarn("No space in %s\n", LOSTDIR); 1105 lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0; 1106 return FSERROR; 1107 } 1108 lfoff = (lfcl - CLUST_FIRST) * boot->ClusterSize 1109 + boot->FirstCluster * boot->bpbBytesPerSec; 1110 1111 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1112 || (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1113 perr("could not read LOST.DIR"); 1114 return FSFATAL; 1115 } 1116 p = lfbuf; 1117 } 1118 1119 boot->NumFiles++; 1120 /* Ensure uniqueness of entry here! XXX */ 1121 memset(&d, 0, sizeof d); 1122 /* worst case -1 = 4294967295, 10 digits */ 1123 len = snprintf(d.name, sizeof(d.name), "%u", head); 1124 d.flags = 0; 1125 d.head = head; 1126 d.size = length * boot->ClusterSize; 1127 1128 memcpy(p, d.name, len); 1129 memset(p + len, ' ', 11 - len); 1130 memset(p + 11, 0, 32 - 11); 1131 p[26] = (u_char)d.head; 1132 p[27] = (u_char)(d.head >> 8); 1133 if (boot->ClustMask == CLUST32_MASK) { 1134 p[20] = (u_char)(d.head >> 16); 1135 p[21] = (u_char)(d.head >> 24); 1136 } 1137 p[28] = (u_char)d.size; 1138 p[29] = (u_char)(d.size >> 8); 1139 p[30] = (u_char)(d.size >> 16); 1140 p[31] = (u_char)(d.size >> 24); 1141 if (lseek(dosfs, lfoff, SEEK_SET) != lfoff 1142 || (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) { 1143 perr("could not write LOST.DIR"); 1144 return FSFATAL; 1145 } 1146 return FSDIRMOD; 1147 } 1148 1149 void 1150 finishlf(void) 1151 { 1152 if (lfbuf) 1153 free(lfbuf); 1154 lfbuf = NULL; 1155 } 1156