bsd/hfs/hfs_format.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 #ifndef __HFS_FORMAT__
  23 #define __HFS_FORMAT__
  24
  25 #include <sys/appleapiopts.h>
  26
  27 /*
  28  * hfs_format.c
  29  *
  30  * This file describes the on-disk format for HFS and HFS Plus volumes.
  31  * The HFS Plus volume format is desciibed in detail in Apple Technote 1150.
  32  *
  33  * http://developer.apple.com/technotes/tn/tn1150.html
  34  *
  35  */
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 /* some on-disk hfs structures have 68K alignment (misaligned) */
  42 #pragma options align=mac68k
  43
  44 /* Signatures used to differentiate between HFS and HFS Plus volumes */
  45 enum {
  46         kHFSSigWord             = 0x4244,       /* 'BD' in ASCII */
  47         kHFSPlusSigWord         = 0x482B,       /* 'H+' in ASCII */
  48         kHFSPlusVersion         = 0x0004,       /* will change as format changes */
  49                                                 /* version 4 shipped with Mac OS 8.1 */
  50         kHFSPlusMountVersion    = 0x31302E30    /* '10.0' for Mac OS X */
  51 };
  52
  53
  54 #ifdef __APPLE_API_PRIVATE
  55 /*
  56  * Mac OS X has a special directory for linked and unlinked files (HFS Plus only).
  57  * This directory and its contents are never exported from the filesystem under
  58  * Mac OS X.
  59  *
  60  * To make this folder name sort last,  it has embedded null prefix.
  61  * (0xC0, 0x80 in UTF-8)
  62  */
  63 #define HFSPLUSMETADATAFOLDER  "\xC0\x80\xC0\x80\xC0\x80\xC0\x80HFS+ Private Data"
  64
  65 /*
  66  * Files in the HFS Private Data folder have one of the following prefixes
  67  * followed by a decimal number (no leading zeros).  For indirect nodes this
  68  * number is a 32 bit random number.  For unlinked (deleted) files that are
  69  * still open, the number is the file ID for that file.
  70  *
  71  * e.g.  iNode7182000 and temp3296
  72  */
  73 #define HFS_INODE_PREFIX        "iNode"
  74 #define HFS_DELETE_PREFIX       "temp"
  75
  76 #endif /* __APPLE_API_PRIVATE */
  77
  78 /*
  79  * Indirect link files (hard links) have the following type/creator.
  80  */
  81 enum {
  82         kHardLinkFileType = 0x686C6E6B,  /* 'hlnk' */
  83         kHFSPlusCreator   = 0x6866732B   /* 'hfs+' */
  84 };
  85
  86
  87 /* Unicode strings are used for HFS Plus file and folder names */
  88 struct HFSUniStr255 {
  89         u_int16_t       length;         /* number of unicode characters */
  90         u_int16_t       unicode[255];   /* unicode characters */
  91 };
  92 typedef struct HFSUniStr255 HFSUniStr255;
  93 typedef const HFSUniStr255 *ConstHFSUniStr255Param;
  94
  95 enum {
  96         kHFSMaxVolumeNameChars          = 27,
  97         kHFSMaxFileNameChars            = 31,
  98         kHFSPlusMaxFileNameChars        = 255
  99 };
 100
 101
 102 /* Extent overflow file data structures */
 103
 104 /* HFS Extent key */
 105 struct HFSExtentKey {
 106         u_int8_t        keyLength;      /* length of key, excluding this field */
 107         u_int8_t        forkType;       /* 0 = data fork, FF = resource fork */
 108         u_int32_t       fileID;         /* file ID */
 109         u_int16_t       startBlock;     /* first file allocation block number in this extent */
 110 };
 111 typedef struct HFSExtentKey HFSExtentKey;
 112
 113 /* HFS Plus Extent key */
 114 struct HFSPlusExtentKey {
 115         u_int16_t       keyLength;              /* length of key, excluding this field */
 116         u_int8_t        forkType;               /* 0 = data fork, FF = resource fork */
 117         u_int8_t        pad;                    /* make the other fields align on 32-bit boundary */
 118         u_int32_t       fileID;                 /* file ID */
 119         u_int32_t       startBlock;             /* first file allocation block number in this extent */
 120 };
 121 typedef struct HFSPlusExtentKey HFSPlusExtentKey;
 122
 123 /* Number of extent descriptors per extent record */
 124 enum {
 125         kHFSExtentDensity       = 3,
 126         kHFSPlusExtentDensity   = 8
 127 };
 128
 129 /* HFS extent descriptor */
 130 struct HFSExtentDescriptor {
 131         u_int16_t       startBlock;             /* first allocation block */
 132         u_int16_t       blockCount;             /* number of allocation blocks */
 133 };
 134 typedef struct HFSExtentDescriptor HFSExtentDescriptor;
 135
 136 /* HFS Plus extent descriptor */
 137 struct HFSPlusExtentDescriptor {
 138         u_int32_t       startBlock;             /* first allocation block */
 139         u_int32_t       blockCount;             /* number of allocation blocks */
 140 };
 141 typedef struct HFSPlusExtentDescriptor HFSPlusExtentDescriptor;
 142
 143 /* HFS extent record */
 144 typedef HFSExtentDescriptor HFSExtentRecord[3];
 145
 146 /* HFS Plus extent record */
 147 typedef HFSPlusExtentDescriptor HFSPlusExtentRecord[8];
 148
 149
 150 /* Finder information */
 151 struct FndrFileInfo {
 152         u_int32_t       fdType;         /* file type */
 153         u_int32_t       fdCreator;      /* file creator */
 154         u_int16_t       fdFlags;        /* Finder flags */
 155         struct {
 156             int16_t     v;              /* file's location */
 157             int16_t     h;
 158         } fdLocation;
 159         int16_t         opaque;
 160 };
 161 typedef struct FndrFileInfo FndrFileInfo;
 162
 163 struct FndrDirInfo {
 164         struct {                        /* folder's window rectangle */
 165             int16_t     top;
 166             int16_t     left;
 167             int16_t     bottom;
 168             int16_t     right;
 169         } frRect;
 170         unsigned short  frFlags;        /* Finder flags */
 171         struct {
 172             u_int16_t   v;              /* folder's location */
 173             u_int16_t   h;
 174         } frLocation;
 175         int16_t         opaque;
 176 };
 177 typedef struct FndrDirInfo FndrDirInfo;
 178
 179 struct FndrOpaqueInfo {
 180         int8_t opaque[16];
 181 };
 182 typedef struct FndrOpaqueInfo FndrOpaqueInfo;
 183
 184
 185 /* HFS Plus Fork data info - 80 bytes */
 186 struct HFSPlusForkData {
 187         u_int64_t               logicalSize;    /* fork's logical size in bytes */
 188         u_int32_t               clumpSize;      /* fork's clump size in bytes */
 189         u_int32_t               totalBlocks;    /* total blocks used by this fork */
 190         HFSPlusExtentRecord     extents;        /* initial set of extents */
 191 };
 192 typedef struct HFSPlusForkData HFSPlusForkData;
 193
 194
 195 /* Mac OS X has 16 bytes worth of "BSD" info.
 196  *
 197  * Note:  Mac OS 9 implementations and applications
 198  * should preserve, but not change, this information.
 199  */
 200 struct HFSPlusBSDInfo {
 201         u_int32_t       ownerID;        /* user or group ID of file/folder owner */
 202         u_int32_t       groupID;        /* additional user of group ID */
 203         u_int8_t        adminFlags;     /* super-user changeable flags */
 204         u_int8_t        ownerFlags;     /* owner changeable flags */
 205         u_int16_t       fileMode;       /* file type and permission bits */
 206         union {
 207             u_int32_t   iNodeNum;       /* indirect node number (hard links only) */
 208             u_int32_t   linkCount;      /* links that refer to this indirect node */
 209             u_int32_t   rawDevice;      /* special file device (FBLK and FCHR only) */
 210         } special;
 211 };
 212 typedef struct HFSPlusBSDInfo HFSPlusBSDInfo;
 213
 214
 215 /* Catalog file data structures */
 216
 217 enum {
 218         kHFSRootParentID                = 1,    /* Parent ID of the root folder */
 219         kHFSRootFolderID                = 2,    /* Folder ID of the root folder */
 220         kHFSExtentsFileID               = 3,    /* File ID of the extents file */
 221         kHFSCatalogFileID               = 4,    /* File ID of the catalog file */
 222         kHFSBadBlockFileID              = 5,    /* File ID of the bad allocation block file */
 223         kHFSAllocationFileID            = 6,    /* File ID of the allocation file (HFS Plus only) */
 224         kHFSStartupFileID               = 7,    /* File ID of the startup file (HFS Plus only) */
 225         kHFSAttributesFileID            = 8,    /* File ID of the attribute file (HFS Plus only) */
 226         kHFSBogusExtentFileID           = 15,   /* Used for exchanging extents in extents file */
 227         kHFSFirstUserCatalogNodeID      = 16
 228 };
 229
 230 /* HFS catalog key */
 231 struct HFSCatalogKey {
 232         u_int8_t        keyLength;              /* key length (in bytes) */
 233         u_int8_t        reserved;               /* reserved (set to zero) */
 234         u_int32_t       parentID;               /* parent folder ID */
 235         u_char          nodeName[kHFSMaxFileNameChars + 1]; /* catalog node name */
 236 };
 237 typedef struct HFSCatalogKey HFSCatalogKey;
 238
 239 /* HFS Plus catalog key */
 240 struct HFSPlusCatalogKey {
 241         u_int16_t               keyLength;      /* key length (in bytes) */
 242         u_int32_t               parentID;       /* parent folder ID */
 243         HFSUniStr255            nodeName;       /* catalog node name */
 244 };
 245 typedef struct HFSPlusCatalogKey HFSPlusCatalogKey;
 246
 247 /* Catalog record types */
 248 enum {
 249         /* HFS Catalog Records */
 250         kHFSFolderRecord                = 0x0100,       /* Folder record */
 251         kHFSFileRecord                  = 0x0200,       /* File record */
 252         kHFSFolderThreadRecord          = 0x0300,       /* Folder thread record */
 253         kHFSFileThreadRecord            = 0x0400,       /* File thread record */
 254
 255         /* HFS Plus Catalog Records */
 256         kHFSPlusFolderRecord            = 1,            /* Folder record */
 257         kHFSPlusFileRecord              = 2,            /* File record */
 258         kHFSPlusFolderThreadRecord      = 3,            /* Folder thread record */
 259         kHFSPlusFileThreadRecord        = 4             /* File thread record */
 260 };
 261
 262
 263 /* Catalog file record flags */
 264 enum {
 265         kHFSFileLockedBit       = 0x0000,       /* file is locked and cannot be written to */
 266         kHFSFileLockedMask      = 0x0001,
 267         kHFSThreadExistsBit     = 0x0001,       /* a file thread record exists for this file */
 268         kHFSThreadExistsMask    = 0x0002
 269 };
 270
 271
 272 /* HFS catalog folder record - 70 bytes */
 273 struct HFSCatalogFolder {
 274         int16_t                 recordType;             /* == kHFSFolderRecord */
 275         u_int16_t               flags;                  /* folder flags */
 276         u_int16_t               valence;                /* folder valence */
 277         u_int32_t               folderID;               /* folder ID */
 278         u_int32_t               createDate;             /* date and time of creation */
 279         u_int32_t               modifyDate;             /* date and time of last modification */
 280         u_int32_t               backupDate;             /* date and time of last backup */
 281         FndrDirInfo             userInfo;               /* Finder information */
 282         FndrOpaqueInfo          finderInfo;             /* additional Finder information */
 283         u_int32_t               reserved[4];            /* reserved - initialized as zero */
 284 };
 285 typedef struct HFSCatalogFolder HFSCatalogFolder;
 286
 287 /* HFS Plus catalog folder record - 88 bytes */
 288 struct HFSPlusCatalogFolder {
 289         int16_t                 recordType;             /* == kHFSPlusFolderRecord */
 290         u_int16_t               flags;                  /* file flags */
 291         u_int32_t               valence;                /* folder's valence (limited to 2^16 in Mac OS) */
 292         u_int32_t               folderID;               /* folder ID */
 293         u_int32_t               createDate;             /* date and time of creation */
 294         u_int32_t               contentModDate;         /* date and time of last content modification */
 295         u_int32_t               attributeModDate;       /* date and time of last attribute modification */
 296         u_int32_t               accessDate;             /* date and time of last access (MacOS X only) */
 297         u_int32_t               backupDate;             /* date and time of last backup */
 298         HFSPlusBSDInfo          bsdInfo;                /* permissions (for MacOS X) */
 299         FndrDirInfo             userInfo;               /* Finder information */
 300         FndrOpaqueInfo          finderInfo;             /* additional Finder information */
 301         u_int32_t               textEncoding;           /* hint for name conversions */
 302         u_int32_t               reserved;               /* reserved - initialized as zero */
 303 };
 304 typedef struct HFSPlusCatalogFolder HFSPlusCatalogFolder;
 305
 306 /* HFS catalog file record - 102 bytes */
 307 struct HFSCatalogFile {
 308         int16_t                 recordType;             /* == kHFSFileRecord */
 309         u_int8_t                flags;                  /* file flags */
 310         int8_t                  fileType;               /* file type (unused ?) */
 311         FndrFileInfo            userInfo;               /* Finder information */
 312         u_int32_t               fileID;                 /* file ID */
 313         u_int16_t               dataStartBlock;         /* not used - set to zero */
 314         int32_t                 dataLogicalSize;        /* logical EOF of data fork */
 315         int32_t                 dataPhysicalSize;       /* physical EOF of data fork */
 316         u_int16_t               rsrcStartBlock;         /* not used - set to zero */
 317         int32_t                 rsrcLogicalSize;        /* logical EOF of resource fork */
 318         int32_t                 rsrcPhysicalSize;       /* physical EOF of resource fork */
 319         u_int32_t               createDate;             /* date and time of creation */
 320         u_int32_t               modifyDate;             /* date and time of last modification */
 321         u_int32_t               backupDate;             /* date and time of last backup */
 322         FndrOpaqueInfo          finderInfo;             /* additional Finder information */
 323         u_int16_t               clumpSize;              /* file clump size (not used) */
 324         HFSExtentRecord         dataExtents;            /* first data fork extent record */
 325         HFSExtentRecord         rsrcExtents;            /* first resource fork extent record */
 326         u_int32_t               reserved;               /* reserved - initialized as zero */
 327 };
 328 typedef struct HFSCatalogFile HFSCatalogFile;
 329
 330 /* HFS Plus catalog file record - 248 bytes */
 331 struct HFSPlusCatalogFile {
 332         int16_t                 recordType;             /* == kHFSPlusFileRecord */
 333         u_int16_t               flags;                  /* file flags */
 334         u_int32_t               reserved1;              /* reserved - initialized as zero */
 335         u_int32_t               fileID;                 /* file ID */
 336         u_int32_t               createDate;             /* date and time of creation */
 337         u_int32_t               contentModDate;         /* date and time of last content modification */
 338         u_int32_t               attributeModDate;       /* date and time of last attribute modification */
 339         u_int32_t               accessDate;             /* date and time of last access (MacOS X only) */
 340         u_int32_t               backupDate;             /* date and time of last backup */
 341         HFSPlusBSDInfo          bsdInfo;                /* permissions (for MacOS X) */
 342         FndrFileInfo            userInfo;               /* Finder information */
 343         FndrOpaqueInfo          finderInfo;             /* additional Finder information */
 344         u_int32_t               textEncoding;           /* hint for name conversions */
 345         u_int32_t               reserved2;              /* reserved - initialized as zero */
 346
 347         /* Note: these start on double long (64 bit) boundry */
 348         HFSPlusForkData         dataFork;               /* size and block data for data fork */
 349         HFSPlusForkData         resourceFork;           /* size and block data for resource fork */
 350 };
 351 typedef struct HFSPlusCatalogFile HFSPlusCatalogFile;
 352
 353 /* HFS catalog thread record - 46 bytes */
 354 struct HFSCatalogThread {
 355         int16_t         recordType;             /* == kHFSFolderThreadRecord or kHFSFileThreadRecord */
 356         int32_t         reserved[2];            /* reserved - initialized as zero */
 357         u_int32_t       parentID;               /* parent ID for this catalog node */
 358         u_char          nodeName[kHFSMaxFileNameChars + 1]; /* name of this catalog node */
 359 };
 360 typedef struct HFSCatalogThread HFSCatalogThread;
 361
 362 /* HFS Plus catalog thread record -- 264 bytes */
 363 struct HFSPlusCatalogThread {
 364         int16_t         recordType;             /* == kHFSPlusFolderThreadRecord or kHFSPlusFileThreadRecord */
 365         int16_t         reserved;               /* reserved - initialized as zero */
 366         u_int32_t       parentID;               /* parent ID for this catalog node */
 367         HFSUniStr255    nodeName;               /* name of this catalog node (variable length) */
 368 };
 369 typedef struct HFSPlusCatalogThread HFSPlusCatalogThread;
 370
 371 #ifdef __APPLE_API_UNSTABLE
 372 /*
 373         These are the types of records in the attribute B-tree.  The values were
 374         chosen so that they wouldn't conflict with the catalog record types.
 375 */
 376 enum {
 377         kHFSPlusAttrInlineData  = 0x10,         /* if size <  kAttrOverflowSize */
 378         kHFSPlusAttrForkData    = 0x20,         /* if size >= kAttrOverflowSize */
 379         kHFSPlusAttrExtents     = 0x30          /* overflow extents for large attributes */
 380 };
 381
 382
 383 /*
 384         HFSPlusAttrInlineData
 385         For small attributes, whose entire value is stored within this one
 386         B-tree record.
 387         There would not be any other records for this attribute.
 388 */
 389 struct HFSPlusAttrInlineData {
 390         u_int32_t       recordType;             /* == kHFSPlusAttrInlineData*/
 391         u_int32_t       reserved;
 392         u_int32_t       logicalSize;            /* size in bytes of userData*/
 393         u_int8_t        userData[2];            /* variable length; space allocated is a multiple of 2 bytes*/
 394 };
 395 typedef struct HFSPlusAttrInlineData HFSPlusAttrInlineData;
 396
 397
 398 /*
 399         HFSPlusAttrForkData
 400         For larger attributes, whose value is stored in allocation blocks.
 401         If the attribute has more than 8 extents, there will be additonal
 402         records (of type HFSPlusAttrExtents) for this attribute.
 403 */
 404 struct HFSPlusAttrForkData {
 405         u_int32_t       recordType;             /* == kHFSPlusAttrForkData*/
 406         u_int32_t       reserved;
 407         HFSPlusForkData theFork;                /* size and first extents of value*/
 408 };
 409 typedef struct HFSPlusAttrForkData HFSPlusAttrForkData;
 410
 411 /*
 412         HFSPlusAttrExtents
 413         This record contains information about overflow extents for large,
 414         fragmented attributes.
 415 */
 416 struct HFSPlusAttrExtents {
 417         u_int32_t               recordType;     /* == kHFSPlusAttrExtents*/
 418         u_int32_t               reserved;
 419         HFSPlusExtentRecord     extents;        /* additional extents*/
 420 };
 421 typedef struct HFSPlusAttrExtents HFSPlusAttrExtents;
 422
 423 /*      A generic Attribute Record*/
 424 union HFSPlusAttrRecord {
 425         u_int32_t               recordType;
 426         HFSPlusAttrInlineData   inlineData;
 427         HFSPlusAttrForkData     forkData;
 428         HFSPlusAttrExtents      overflowExtents;
 429 };
 430 typedef union HFSPlusAttrRecord HFSPlusAttrRecord;
 431
 432 /* Key and node lengths */
 433 enum {
 434         kHFSPlusExtentKeyMaximumLength = sizeof(HFSPlusExtentKey) - sizeof(u_int16_t),
 435         kHFSExtentKeyMaximumLength      = sizeof(HFSExtentKey) - sizeof(u_int8_t),
 436         kHFSPlusCatalogKeyMaximumLength = sizeof(HFSPlusCatalogKey) - sizeof(u_int16_t),
 437         kHFSPlusCatalogKeyMinimumLength = kHFSPlusCatalogKeyMaximumLength - sizeof(HFSUniStr255) + sizeof(u_int16_t),
 438         kHFSCatalogKeyMaximumLength     = sizeof(HFSCatalogKey) - sizeof(u_int8_t),
 439         kHFSCatalogKeyMinimumLength     = kHFSCatalogKeyMaximumLength - (kHFSMaxFileNameChars + 1) + sizeof(u_int8_t),
 440         kHFSPlusCatalogMinNodeSize      = 4096,
 441         kHFSPlusExtentMinNodeSize       = 512,
 442         kHFSPlusAttrMinNodeSize         = 4096
 443 };
 444 #endif /* __APPLE_API_UNSTABLE */
 445
 446 /* HFS and HFS Plus volume attribute bits */
 447 enum {
 448                                                         /* Bits 0-6 are reserved (always cleared by MountVol call) */
 449         kHFSVolumeHardwareLockBit       = 7,            /* volume is locked by hardware */
 450         kHFSVolumeUnmountedBit          = 8,            /* volume was successfully unmounted */
 451         kHFSVolumeSparedBlocksBit       = 9,            /* volume has bad blocks spared */
 452         kHFSVolumeNoCacheRequiredBit = 10,              /* don't cache volume blocks (i.e. RAM or ROM disk) */
 453         kHFSBootVolumeInconsistentBit = 11,             /* boot volume is inconsistent (System 7.6 and later) */
 454         kHFSCatalogNodeIDsReusedBit = 12,
 455                                                         /* Bits 13-14 are reserved for future use */
 456         kHFSVolumeSoftwareLockBit       = 15,           /* volume is locked by software */
 457
 458         kHFSVolumeHardwareLockMask      = 1 << kHFSVolumeHardwareLockBit,
 459         kHFSVolumeUnmountedMask         = 1 << kHFSVolumeUnmountedBit,
 460         kHFSVolumeSparedBlocksMask      = 1 << kHFSVolumeSparedBlocksBit,
 461         kHFSVolumeNoCacheRequiredMask = 1 << kHFSVolumeNoCacheRequiredBit,
 462         kHFSBootVolumeInconsistentMask = 1 << kHFSBootVolumeInconsistentBit,
 463         kHFSCatalogNodeIDsReusedMask = 1 << kHFSCatalogNodeIDsReusedBit,
 464         kHFSVolumeSoftwareLockMask      = 1 << kHFSVolumeSoftwareLockBit,
 465         kHFSMDBAttributesMask           = 0x8380
 466 };
 467
 468
 469 /* HFS Master Directory Block - 162 bytes */
 470 /* Stored at sector #2 (3rd sector) and second-to-last sector. */
 471 struct HFSMasterDirectoryBlock {
 472         u_int16_t               drSigWord;      /* == kHFSSigWord */
 473         u_int32_t               drCrDate;       /* date and time of volume creation */
 474         u_int32_t               drLsMod;        /* date and time of last modification */
 475         u_int16_t               drAtrb;         /* volume attributes */
 476         u_int16_t               drNmFls;        /* number of files in root folder */
 477         u_int16_t               drVBMSt;        /* first block of volume bitmap */
 478         u_int16_t               drAllocPtr;     /* start of next allocation search */
 479         u_int16_t               drNmAlBlks;     /* number of allocation blocks in volume */
 480         u_int32_t               drAlBlkSiz;     /* size (in bytes) of allocation blocks */
 481         u_int32_t               drClpSiz;       /* default clump size */
 482         u_int16_t               drAlBlSt;       /* first allocation block in volume */
 483         u_int32_t               drNxtCNID;      /* next unused catalog node ID */
 484         u_int16_t               drFreeBks;      /* number of unused allocation blocks */
 485         u_char                  drVN[kHFSMaxVolumeNameChars + 1];  /* volume name */
 486         u_int32_t               drVolBkUp;      /* date and time of last backup */
 487         u_int16_t               drVSeqNum;      /* volume backup sequence number */
 488         u_int32_t               drWrCnt;        /* volume write count */
 489         u_int32_t               drXTClpSiz;     /* clump size for extents overflow file */
 490         u_int32_t               drCTClpSiz;     /* clump size for catalog file */
 491         u_int16_t               drNmRtDirs;     /* number of directories in root folder */
 492         u_int32_t               drFilCnt;       /* number of files in volume */
 493         u_int32_t               drDirCnt;       /* number of directories in volume */
 494         u_int32_t               drFndrInfo[8];  /* information used by the Finder */
 495         u_int16_t               drEmbedSigWord; /* embedded volume signature (formerly drVCSize) */
 496         HFSExtentDescriptor     drEmbedExtent;  /* embedded volume location and size (formerly drVBMCSize and drCtlCSize) */
 497         u_int32_t               drXTFlSize;     /* size of extents overflow file */
 498         HFSExtentRecord         drXTExtRec;     /* extent record for extents overflow file */
 499         u_int32_t               drCTFlSize;     /* size of catalog file */
 500         HFSExtentRecord         drCTExtRec;     /* extent record for catalog file */
 501 };
 502 typedef struct HFSMasterDirectoryBlock  HFSMasterDirectoryBlock;
 503
 504
 505 /* HFS Plus Volume Header - 512 bytes */
 506 /* Stored at sector #2 (3rd sector) and second-to-last sector. */
 507 struct HFSPlusVolumeHeader {
 508         u_int16_t       signature;              /* == kHFSPlusSigWord */
 509         u_int16_t       version;                /* == kHFSPlusVersion */
 510         u_int32_t       attributes;             /* volume attributes */
 511         u_int32_t       lastMountedVersion;     /* implementation version which last mounted volume */
 512         u_int32_t       reserved;               /* reserved - initialized as zero */
 513
 514         u_int32_t       createDate;             /* date and time of volume creation */
 515         u_int32_t       modifyDate;             /* date and time of last modification */
 516         u_int32_t       backupDate;             /* date and time of last backup */
 517         u_int32_t       checkedDate;            /* date and time of last disk check */
 518
 519         u_int32_t       fileCount;              /* number of files in volume */
 520         u_int32_t       folderCount;            /* number of directories in volume */
 521
 522         u_int32_t       blockSize;              /* size (in bytes) of allocation blocks */
 523         u_int32_t       totalBlocks;            /* number of allocation blocks in volume (includes this header and VBM*/
 524         u_int32_t       freeBlocks;             /* number of unused allocation blocks */
 525
 526         u_int32_t       nextAllocation;         /* start of next allocation search */
 527         u_int32_t       rsrcClumpSize;          /* default resource fork clump size */
 528         u_int32_t       dataClumpSize;          /* default data fork clump size */
 529         u_int32_t       nextCatalogID;          /* next unused catalog node ID */
 530
 531         u_int32_t       writeCount;             /* volume write count */
 532         u_int64_t       encodingsBitmap;        /* which encodings have been use  on this volume */
 533
 534         u_int8_t        finderInfo[32];         /* information used by the Finder */
 535
 536         HFSPlusForkData  allocationFile;        /* allocation bitmap file */
 537         HFSPlusForkData  extentsFile;           /* extents B-tree file */
 538         HFSPlusForkData  catalogFile;           /* catalog B-tree file */
 539         HFSPlusForkData  attributesFile;        /* extended attributes B-tree file */
 540         HFSPlusForkData  startupFile;           /* boot file (secondary loader) */
 541 };
 542 typedef struct HFSPlusVolumeHeader HFSPlusVolumeHeader;
 543
 544
 545 /* B-tree structures */
 546
 547 enum BTreeKeyLimits{
 548         kMaxKeyLength   = 520
 549 };
 550
 551 union BTreeKey{
 552         u_int8_t        length8;
 553         u_int16_t       length16;
 554         u_int8_t        rawData [kMaxKeyLength+2];
 555 };
 556 typedef union BTreeKey BTreeKey;
 557
 558 /* BTNodeDescriptor -- Every B-tree node starts with these fields. */
 559 struct BTNodeDescriptor {
 560         u_int32_t       fLink;                  /* next node at this level*/
 561         u_int32_t       bLink;                  /* previous node at this level*/
 562         int8_t          kind;                   /* kind of node (leaf, index, header, map)*/
 563         u_int8_t        height;                 /* zero for header, map; child is one more than parent*/
 564         u_int16_t       numRecords;             /* number of records in this node*/
 565         u_int16_t       reserved;               /* reserved - initialized as zero */
 566 };
 567 typedef struct BTNodeDescriptor BTNodeDescriptor;
 568
 569 /* Constants for BTNodeDescriptor kind */
 570 enum {
 571         kBTLeafNode     = -1,
 572         kBTIndexNode    = 0,
 573         kBTHeaderNode   = 1,
 574         kBTMapNode      = 2
 575 };
 576
 577 /* BTHeaderRec -- The first record of a B-tree header node */
 578 struct BTHeaderRec {
 579         u_int16_t       treeDepth;              /* maximum height (usually leaf nodes) */
 580         u_int32_t       rootNode;               /* node number of root node */
 581         u_int32_t       leafRecords;            /* number of leaf records in all leaf nodes */
 582         u_int32_t       firstLeafNode;          /* node number of first leaf node */
 583         u_int32_t       lastLeafNode;           /* node number of last leaf node */
 584         u_int16_t       nodeSize;               /* size of a node, in bytes */
 585         u_int16_t       maxKeyLength;           /* reserved */
 586         u_int32_t       totalNodes;             /* total number of nodes in tree */
 587         u_int32_t       freeNodes;              /* number of unused (free) nodes in tree */
 588         u_int16_t       reserved1;              /* unused */
 589         u_int32_t       clumpSize;              /* reserved */
 590         u_int8_t        btreeType;              /* reserved */
 591         u_int8_t        reserved2;              /* reserved */
 592         u_int32_t       attributes;             /* persistent attributes about the tree */
 593         u_int32_t       reserved3[16];          /* reserved */
 594 };
 595 typedef struct BTHeaderRec BTHeaderRec;
 596
 597 /* Constants for BTHeaderRec attributes */
 598 enum {
 599         kBTBadCloseMask          = 0x00000001,  /* reserved */
 600         kBTBigKeysMask           = 0x00000002,  /* key length field is 16 bits */
 601         kBTVariableIndexKeysMask = 0x00000004   /* keys in index nodes are variable length */
 602 };
 603
 604 #pragma options align=reset
 605
 606 #ifdef __cplusplus
 607 }
 608 #endif
 609
 610 #endif /* __HFS_FORMAT__ */