fsck_hfs/dfalib/SBTree.c

   1 /*
   2  * Copyright (c) 1999, 2002, 2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24         File:           SBTree.c
  25
  26         Contains:       Scavanger B-tree callback procs
  27
  28         Version:        HFS Plus 1.0
  29
  30         Copyright:      © 1996-1999 by Apple Computer, Inc., all rights reserved.
  31
  32 */
  33
  34
  35 #include "BTree.h"
  36 #include "BTreePrivate.h"
  37 #include "Scavenger.h"
  38
  39
  40
  41 // local routines
  42 static void     InvalidateBTreeIterator ( SFCB *fcb );
  43 static OSErr    CheckBTreeKey(const BTreeKey *key, const BTreeControlBlock *btcb);
  44 static Boolean  ValidHFSRecord(const void *record, const BTreeControlBlock *btcb, UInt16 recordSize);
  45
  46
  47 //      This function determines the size of the output buffer depending on
  48 //      the type of the BTree.  It should really be taking the buffer size
  49 //      as input instead of assuming it (4425231).
  50 //
  51 //      This function may also truncate inline attribute record because caller
  52 //      sends HFSPlusAttrRecord as output buffer and this function also assumes
  53 //      the output buffer of size HFSPlusAttrRecord.  It may therefore not be
  54 //      enough to copy entire inline attribute record (4425232).
  55
  56 OSErr SearchBTreeRecord(SFCB *fcb, const void* key, UInt32 hint, void* foundKey, void* data, UInt16 *dataSize, UInt32 *newHint)
  57 {
  58         FSBufferDescriptor       btRecord;
  59         BTreeIterator            searchIterator;
  60         BTreeIterator           *resultIterator;
  61         BTreeControlBlock       *btcb;
  62         OSStatus                         result;
  63
  64
  65         btcb = (BTreeControlBlock*) fcb->fcbBtree;
  66
  67         btRecord.bufferAddress = data;
  68         btRecord.itemCount = 1;
  69         if ( btcb->maxKeyLength == kHFSExtentKeyMaximumLength )
  70                 btRecord.itemSize = sizeof(HFSExtentRecord);
  71         else if ( btcb->maxKeyLength == kHFSPlusExtentKeyMaximumLength )
  72                 btRecord.itemSize = sizeof(HFSPlusExtentRecord);
  73         else if ( btcb->maxKeyLength == kHFSPlusAttrKeyMaximumLength )
  74                 btRecord.itemSize = sizeof(HFSPlusAttrRecord);
  75         else
  76                 btRecord.itemSize = sizeof(CatalogRecord);
  77
  78         searchIterator.hint.writeCount = 0;     // clear these out for debugging...
  79         searchIterator.hint.reserved1 = 0;
  80         searchIterator.hint.reserved2 = 0;
  81
  82         searchIterator.hint.nodeNum = hint;
  83         searchIterator.hint.index = 0;
  84
  85         result = CheckBTreeKey((BTreeKey *) key, btcb);
  86         ExitOnError(result);
  87
  88         CopyMemory(key, &searchIterator.key, CalcKeySize(btcb, (BTreeKey *) key));              //¥¥ should we range check against maxkeylen?
  89
  90         resultIterator = &btcb->lastIterator;
  91
  92         result = BTSearchRecord( fcb, &searchIterator, kInvalidMRUCacheKey, &btRecord, dataSize, resultIterator );
  93         if (result == noErr)
  94         {
  95                 if (newHint != NULL)
  96                         *newHint = resultIterator->hint.nodeNum;
  97
  98                 result = CheckBTreeKey(&resultIterator->key, btcb);
  99                 ExitOnError(result);
 100
 101                 if (foundKey != NULL)
 102                         CopyMemory(&resultIterator->key, foundKey, CalcKeySize(btcb, &resultIterator->key));    //¥¥ warning, this could overflow user's buffer!!!
 103
 104                 if ( DEBUG_BUILD && !ValidHFSRecord(data, btcb, *dataSize) )
 105                         DebugStr("\pSearchBTreeRecord: bad record?");
 106         }
 107
 108 ErrorExit:
 109
 110         return result;
 111 }
 112
 113
 114
 115 //      Note
 116 //      The new B-tree manager differs from the original b-tree in how it does iteration. We need
 117 //      to account for these differences here.  We save an iterator in the BTree control block so
 118 //      that we have a context in which to perfrom the iteration. Also note that the old B-tree
 119 //      allowed you to specify any number relative to the last operation (including 0) whereas the
 120 //      new B-tree only allows next/previous.
 121 //
 122 //      This function determines the size of the output buffer depending on
 123 //      the type of the BTree.  It should really be taking the buffer size
 124 //      as input instead of assuming it (4425231).
 125 //
 126 //      This function may also truncate inline attribute record because caller
 127 //      sends HFSPlusAttrRecord as output buffer and this function also assumes
 128 //      the output buffer of size HFSPlusAttrRecord.  It may therefore not be
 129 //      enough to copy entire inline attribute record (4425232).
 130
 131 OSErr GetBTreeRecord(SFCB *fcb, SInt16 selectionIndex, void* key, void* data, UInt16 *dataSize, UInt32 *newHint)
 132 {
 133         FSBufferDescriptor      btRecord;
 134         BTreeIterator           *iterator;
 135         BTreeControlBlock       *btcb;
 136         OSStatus                        result;
 137         UInt16                          operation;
 138
 139
 140         // pick up our iterator in the BTCB for context...
 141
 142         btcb = (BTreeControlBlock*) fcb->fcbBtree;
 143         iterator = &btcb->lastIterator;
 144
 145         btRecord.bufferAddress = data;
 146         btRecord.itemCount = 1;
 147         if ( btcb->maxKeyLength == kHFSExtentKeyMaximumLength )
 148                 btRecord.itemSize = sizeof(HFSExtentRecord);
 149         else if ( btcb->maxKeyLength == kHFSPlusExtentKeyMaximumLength )
 150                 btRecord.itemSize = sizeof(HFSPlusExtentRecord);
 151         else if ( btcb->maxKeyLength == kHFSPlusAttrKeyMaximumLength )
 152                 btRecord.itemSize = sizeof(HFSPlusAttrRecord);
 153         else
 154                 btRecord.itemSize = sizeof(CatalogRecord);
 155
 156         // now we have to map index into next/prev operations...
 157
 158         if (selectionIndex == 1)
 159         {
 160                 operation = kBTreeNextRecord;
 161         }
 162         else if (selectionIndex == -1)
 163         {
 164                 operation = kBTreePrevRecord;
 165         }
 166         else if (selectionIndex == 0)
 167         {
 168                 operation = kBTreeCurrentRecord;
 169         }
 170         else if (selectionIndex == (SInt16) 0x8001)
 171         {
 172                 operation = kBTreeFirstRecord;
 173         }
 174         else if (selectionIndex == (SInt16) 0x7FFF)
 175         {
 176                 operation = kBTreeLastRecord;
 177         }
 178         else if (selectionIndex > 1)
 179         {
 180                 UInt32  i;
 181
 182                 for (i = 1; i < selectionIndex; ++i)
 183                 {
 184                         result = BTIterateRecord( fcb, kBTreeNextRecord, iterator, &btRecord, dataSize );
 185                         ExitOnError(result);
 186                 }
 187                 operation = kBTreeNextRecord;
 188         }
 189         else // (selectionIndex < -1)
 190         {
 191                 SInt32  i;
 192
 193                 for (i = -1; i > selectionIndex; --i)
 194                 {
 195                         result = BTIterateRecord( fcb, kBTreePrevRecord, iterator, &btRecord, dataSize );
 196                         ExitOnError(result);
 197                 }
 198                 operation = kBTreePrevRecord;
 199         }
 200
 201         result = BTIterateRecord( fcb, operation, iterator, &btRecord, dataSize );
 202
 203         if (result == noErr)
 204         {
 205                 *newHint = iterator->hint.nodeNum;
 206
 207                 result = CheckBTreeKey(&iterator->key, btcb);
 208                 ExitOnError(result);
 209
 210                 CopyMemory(&iterator->key, key, CalcKeySize(btcb, &iterator->key));     //¥¥ warning, this could overflow user's buffer!!!
 211
 212                 if ( DEBUG_BUILD && !ValidHFSRecord(data, btcb, *dataSize) )
 213                         DebugStr("\pGetBTreeRecord: bad record?");
 214
 215         }
 216
 217 ErrorExit:
 218
 219         return result;
 220 }
 221
 222
 223 OSErr InsertBTreeRecord(SFCB *fcb, const void* key, const void* data, UInt16 dataSize, UInt32 *newHint)
 224 {
 225         FSBufferDescriptor      btRecord;
 226         BTreeIterator           iterator;
 227         BTreeControlBlock       *btcb;
 228         OSStatus                        result;
 229
 230
 231         btcb = (BTreeControlBlock*) fcb->fcbBtree;
 232
 233         btRecord.bufferAddress = (void *)data;
 234         btRecord.itemSize = dataSize;
 235         btRecord.itemCount = 1;
 236
 237         iterator.hint.nodeNum = 0;                      // no hint
 238
 239         result = CheckBTreeKey((BTreeKey *) key, btcb);
 240         ExitOnError(result);
 241
 242         CopyMemory(key, &iterator.key, CalcKeySize(btcb, (BTreeKey *) key));    //¥¥ should we range check against maxkeylen?
 243
 244         if ( DEBUG_BUILD && !ValidHFSRecord(data, btcb, dataSize) )
 245                 DebugStr("\pInsertBTreeRecord: bad record?");
 246
 247         result = BTInsertRecord( fcb, &iterator, &btRecord, dataSize );
 248
 249         *newHint = iterator.hint.nodeNum;
 250
 251         InvalidateBTreeIterator(fcb);   // invalidate current record markers
 252
 253 ErrorExit:
 254
 255         return result;
 256 }
 257
 258
 259 OSErr DeleteBTreeRecord(SFCB *fcb, const void* key)
 260 {
 261         BTreeIterator           iterator;
 262         BTreeControlBlock       *btcb;
 263         OSStatus                        result;
 264
 265
 266         btcb = (BTreeControlBlock*) fcb->fcbBtree;
 267
 268         iterator.hint.nodeNum = 0;                      // no hint
 269
 270         result = CheckBTreeKey((BTreeKey *) key, btcb);
 271         ExitOnError(result);
 272
 273         CopyMemory(key, &iterator.key, CalcKeySize(btcb, (BTreeKey *) key));    //¥¥ should we range check against maxkeylen?
 274
 275         result = BTDeleteRecord( fcb, &iterator );
 276
 277         InvalidateBTreeIterator(fcb);   // invalidate current record markers
 278
 279 ErrorExit:
 280
 281         return result;
 282 }
 283
 284
 285 OSErr ReplaceBTreeRecord(SFCB *fcb, const void* key, UInt32 hint, void *newData, UInt16 dataSize, UInt32 *newHint)
 286 {
 287         FSBufferDescriptor      btRecord;
 288         BTreeIterator           iterator;
 289         BTreeControlBlock       *btcb;
 290         OSStatus                        result;
 291
 292
 293         btcb = (BTreeControlBlock*) fcb->fcbBtree;
 294
 295         btRecord.bufferAddress = newData;
 296         btRecord.itemSize = dataSize;
 297         btRecord.itemCount = 1;
 298
 299         iterator.hint.nodeNum = hint;
 300
 301         result = CheckBTreeKey((BTreeKey *) key, btcb);
 302         ExitOnError(result);
 303
 304         CopyMemory(key, &iterator.key, CalcKeySize(btcb, (BTreeKey *) key));            //¥¥ should we range check against maxkeylen?
 305
 306         if ( DEBUG_BUILD && !ValidHFSRecord(newData, btcb, dataSize) )
 307                 DebugStr("\pReplaceBTreeRecord: bad record?");
 308
 309         result = BTReplaceRecord( fcb, &iterator, &btRecord, dataSize );
 310
 311         *newHint = iterator.hint.nodeNum;
 312
 313         //¥¥Êdo we need to invalidate the iterator?
 314
 315 ErrorExit:
 316
 317         return result;
 318 }
 319
 320
 321 OSStatus
 322 SetEndOfForkProc ( SFCB *filePtr, FSSize minEOF, FSSize maxEOF )
 323 {
 324 #pragma unused (maxEOF)
 325
 326         OSStatus        result;
 327         UInt32          actualSectorsAdded;
 328         UInt64          bytesToAdd;
 329         UInt64          fileSize;                               //      in sectors
 330         SVCB *          vcb;
 331         UInt32          flags;
 332
 333
 334         if ( minEOF > filePtr->fcbLogicalSize )
 335         {
 336                 bytesToAdd = minEOF - filePtr->fcbLogicalSize;
 337
 338                 if (bytesToAdd < filePtr->fcbClumpSize)
 339                         bytesToAdd = filePtr->fcbClumpSize;             //¥¥Êwhy not always be a mutiple of clump size ???
 340         }
 341         else
 342         {
 343                 if ( DEBUG_BUILD )
 344                         DebugStr("\pSetEndOfForkProc: minEOF is smaller than current size!");
 345                 return -1;
 346         }
 347
 348         vcb = filePtr->fcbVolume;
 349
 350         flags = kEFNoClumpMask;
 351
 352         // Due to time contraints we force the new rebuilt catalog file to be contiguous.
 353         // It's hard to handle catalog file in extents because we have to do a swap
 354         // of the old catalog file with the rebuilt catalog file at the end of
 355         // the rebuild process.  Extent records use the file ID as part of the key so
 356         // it would be messy to fix them after the swap.
 357         if ( filePtr->fcbFileID == kHFSRepairCatalogFileID)
 358                 flags |= kEFNoExtOvflwMask;
 359
 360         result = ExtendFileC ( vcb, filePtr, (bytesToAdd+511)>>9, flags, &actualSectorsAdded );
 361         ReturnIfError(result);
 362
 363         filePtr->fcbLogicalSize = filePtr->fcbPhysicalSize;     // new B-tree looks at fcbEOF
 364         fileSize = filePtr->fcbLogicalSize >> 9;                // get size in sectors (for calls to ZeroFileBlocks)
 365
 366         //
 367         //      Make sure we got at least as much space as we needed
 368         //
 369         if (filePtr->fcbLogicalSize < minEOF) {
 370                 Panic("\pSetEndOfForkProc: disk too full to extend B-tree file");
 371                 return dskFulErr;
 372         }
 373
 374         //
 375         //      Update the Alternate MDB or Alternate HFSPlusVolumeHeader
 376         //
 377         if ( vcb->vcbSignature == kHFSPlusSigWord )
 378         {
 379                 //      If any of the HFS+ private files change size, flush them back to the Alternate volume header
 380                 if (    (filePtr->fcbFileID == kHFSExtentsFileID)
 381                          ||     (filePtr->fcbFileID == kHFSCatalogFileID)
 382                          ||     (filePtr->fcbFileID == kHFSStartupFileID)
 383                          ||     (filePtr->fcbFileID == kHFSAttributesFileID)
 384                          ||     (filePtr->fcbFileID == kHFSRepairCatalogFileID) )
 385                 {
 386                         MarkVCBDirty( vcb );
 387                         result = FlushAlternateVolumeControlBlock( vcb, true );
 388
 389                         //      Zero newly allocated portion of HFS+ private file.
 390                         if ( result == noErr )
 391                                 result = ZeroFileBlocks( vcb, filePtr, fileSize - actualSectorsAdded, actualSectorsAdded );
 392                 }
 393         }
 394         else if ( vcb->vcbSignature == kHFSSigWord )
 395         {
 396                 if ( filePtr->fcbFileID == kHFSExtentsFileID )
 397                 {
 398                 //      vcb->vcbXTAlBlks = filePtr->fcbPhysicalSize / vcb->vcbBlockSize;
 399                         MarkVCBDirty( vcb );
 400                         result = FlushAlternateVolumeControlBlock( vcb, false );
 401                         if ( result == noErr )
 402                                 result = ZeroFileBlocks( vcb, filePtr, fileSize - actualSectorsAdded, actualSectorsAdded );
 403                 }
 404                 else if ( filePtr->fcbFileID == kHFSCatalogFileID || filePtr->fcbFileID == kHFSRepairCatalogFileID )
 405                 {
 406                 //      vcb->vcbCTAlBlks = filePtr->fcbPhysicalSize / vcb->vcbBlockSize;
 407                         MarkVCBDirty( vcb );
 408                         result = FlushAlternateVolumeControlBlock( vcb, false );
 409                         if ( result == noErr )
 410                                 result = ZeroFileBlocks( vcb, filePtr, fileSize - actualSectorsAdded, actualSectorsAdded );
 411                 }
 412         }
 413
 414         return result;
 415
 416 } // end SetEndOfForkProc
 417
 418
 419 static void
 420 InvalidateBTreeIterator(SFCB *fcb)
 421 {
 422         BTreeControlBlock       *btcb;
 423
 424         btcb = (BTreeControlBlock*) fcb->fcbBtree;
 425
 426         (void) BTInvalidateHint ( &btcb->lastIterator );
 427 }
 428
 429
 430 static OSErr CheckBTreeKey(const BTreeKey *key, const BTreeControlBlock *btcb)
 431 {
 432         UInt16  keyLen;
 433
 434         if ( btcb->attributes & kBTBigKeysMask )
 435                 keyLen = key->length16;
 436         else
 437                 keyLen = key->length8;
 438
 439         if ( (keyLen < 6) || (keyLen > btcb->maxKeyLength) )
 440         {
 441                 if ( DEBUG_BUILD )
 442                         DebugStr("\pCheckBTreeKey: bad key length!");
 443                 return fsBTInvalidKeyLengthErr;
 444         }
 445
 446         return noErr;
 447 }
 448
 449
 450 static Boolean ValidHFSRecord(const void *record, const BTreeControlBlock *btcb, UInt16 recordSize)
 451 {
 452         UInt32                  cNodeID;
 453
 454         if ( btcb->maxKeyLength == kHFSExtentKeyMaximumLength )
 455         {
 456                 return ( recordSize == sizeof(HFSExtentRecord) );
 457         }
 458         else if (btcb->maxKeyLength == kHFSPlusExtentKeyMaximumLength )
 459         {
 460                 return ( recordSize == sizeof(HFSPlusExtentRecord) );
 461         }
 462         else if (btcb->maxKeyLength == kAttributeKeyMaximumLength )
 463         {
 464                 HFSPlusAttrRecord       *attributeRecord = (HFSPlusAttrRecord *) record;
 465
 466                 switch (attributeRecord->recordType) {
 467                         case kHFSPlusAttrInlineData:
 468                                 break;
 469
 470                         case kHFSPlusAttrForkData:
 471                                 break;
 472
 473                         case kHFSPlusAttrExtents:
 474                                 break;
 475                 }
 476         }
 477         else // Catalog record
 478         {
 479                 CatalogRecord *catalogRecord = (CatalogRecord*) record;
 480
 481                 switch(catalogRecord->recordType)
 482                 {
 483                         case kHFSFolderRecord:
 484                         {
 485                                 if ( recordSize != sizeof(HFSCatalogFolder) )
 486                                         return false;
 487                                 if ( catalogRecord->hfsFolder.flags != 0 )
 488                                         return false;
 489                                 if ( catalogRecord->hfsFolder.valence > 0x7FFF )
 490                                         return false;
 491
 492                                 cNodeID = catalogRecord->hfsFolder.folderID;
 493
 494                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 495                                         return false;
 496                         }
 497                         break;
 498
 499                         case kHFSPlusFolderRecord:
 500                         {
 501                                 if ( recordSize != sizeof(HFSPlusCatalogFolder) )
 502                                         return false;
 503                                 if ( (catalogRecord->hfsPlusFolder.flags & (kHFSFileLockedMask | kHFSThreadExistsMask)) != 0 )
 504                                         return false;
 505
 506                                 cNodeID = catalogRecord->hfsPlusFolder.folderID;
 507
 508                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 509                                         return false;
 510                         }
 511                         break;
 512
 513                         case kHFSFileRecord:
 514                         {
 515                                 UInt16                                  i;
 516                                 HFSExtentDescriptor     *dataExtent;
 517                                 HFSExtentDescriptor     *rsrcExtent;
 518
 519                                 if ( recordSize != sizeof(HFSCatalogFile) )
 520                                         return false;
 521                                 if ( (catalogRecord->hfsFile.flags & ~(0x83)) != 0 )
 522                                         return false;
 523
 524                                 cNodeID = catalogRecord->hfsFile.fileID;
 525
 526                                 if ( cNodeID < 16 )
 527                                         return false;
 528
 529                                 // make sure 0 ² LEOF ² PEOF for both forks
 530
 531                                 if ( catalogRecord->hfsFile.dataLogicalSize < 0 )
 532                                         return false;
 533                                 if ( catalogRecord->hfsFile.dataPhysicalSize < catalogRecord->hfsFile.dataLogicalSize )
 534                                         return false;
 535                                 if ( catalogRecord->hfsFile.rsrcLogicalSize < 0 )
 536                                         return false;
 537                                 if ( catalogRecord->hfsFile.rsrcPhysicalSize < catalogRecord->hfsFile.rsrcLogicalSize )
 538                                         return false;
 539
 540                                 dataExtent = (HFSExtentDescriptor*) &catalogRecord->hfsFile.dataExtents;
 541                                 rsrcExtent = (HFSExtentDescriptor*) &catalogRecord->hfsFile.rsrcExtents;
 542
 543                                 for (i = 0; i < kHFSExtentDensity; ++i)
 544                                 {
 545                                         if ( (dataExtent[i].blockCount > 0) && (dataExtent[i].startBlock == 0) )
 546                                                 return false;
 547                                         if ( (rsrcExtent[i].blockCount > 0) && (rsrcExtent[i].startBlock == 0) )
 548                                                 return false;
 549                                 }
 550                         }
 551                         break;
 552
 553                         case kHFSPlusFileRecord:
 554                         {
 555                                 UInt16                                  i;
 556                                 HFSPlusExtentDescriptor *dataExtent;
 557                                 HFSPlusExtentDescriptor *rsrcExtent;
 558
 559                                 if ( recordSize != sizeof(HFSPlusCatalogFile) )
 560                                         return false;
 561
 562                                 cNodeID = catalogRecord->hfsPlusFile.fileID;
 563
 564                                 if ( cNodeID < 16 )
 565                                         return false;
 566
 567                                 //¥¥ make sure 0 ² LEOF ² PEOF for both forks
 568
 569                                 dataExtent = (HFSPlusExtentDescriptor*) &catalogRecord->hfsPlusFile.dataFork.extents;
 570                                 rsrcExtent = (HFSPlusExtentDescriptor*) &catalogRecord->hfsPlusFile.resourceFork.extents;
 571
 572                                 for (i = 0; i < kHFSPlusExtentDensity; ++i)
 573                                 {
 574                                         if ( (dataExtent[i].blockCount > 0) && (dataExtent[i].startBlock == 0) )
 575                                                 return false;
 576                                         if ( (rsrcExtent[i].blockCount > 0) && (rsrcExtent[i].startBlock == 0) )
 577                                                 return false;
 578                                 }
 579                         }
 580                         break;
 581
 582                         case kHFSFolderThreadRecord:
 583                         case kHFSFileThreadRecord:
 584                         {
 585                                 if ( recordSize != sizeof(HFSCatalogThread) )
 586                                         return false;
 587
 588                                 cNodeID = catalogRecord->hfsThread.parentID;
 589                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 590                                         return false;
 591
 592                                 if ( (catalogRecord->hfsThread.nodeName[0] == 0) ||
 593                                          (catalogRecord->hfsThread.nodeName[0] > 31) )
 594                                         return false;
 595                         }
 596                         break;
 597
 598                         case kHFSPlusFolderThreadRecord:
 599                         case kHFSPlusFileThreadRecord:
 600                         {
 601                                 if ( recordSize > sizeof(HFSPlusCatalogThread) || recordSize < (sizeof(HFSPlusCatalogThread) - sizeof(HFSUniStr255)))
 602                                         return false;
 603
 604                                 cNodeID = catalogRecord->hfsPlusThread.parentID;
 605                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 606                                         return false;
 607
 608                                 if ( (catalogRecord->hfsPlusThread.nodeName.length == 0) ||
 609                                          (catalogRecord->hfsPlusThread.nodeName.length > 255) )
 610                                         return false;
 611                         }
 612                         break;
 613
 614                         default:
 615                                 return false;
 616                 }
 617         }
 618
 619         return true;    // record appears to be OK
 620 }
 621